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 Free Software Foundation, Inc.
4 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
5 Rewritten by Jason Merrill (jason@cygnus.com).
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* Known bugs or deficiencies include:
25 all methods must be provided in header files; can't use a source
26 file that contains only the method templates and "just win". */
30 #include "coretypes.h"
34 #include "pointer-set.h"
38 #include "cp-objcp-common.h"
39 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct pending_template GTY (()) {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 /* Contains canonical template parameter types. The vector is indexed by
85 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
86 TREE_LIST, whose TREE_VALUEs contain the canonical template
87 parameters of various types and levels. */
88 static GTY(()) VEC(tree,gc) *canonical_template_parms;
90 #define UNIFY_ALLOW_NONE 0
91 #define UNIFY_ALLOW_MORE_CV_QUAL 1
92 #define UNIFY_ALLOW_LESS_CV_QUAL 2
93 #define UNIFY_ALLOW_DERIVED 4
94 #define UNIFY_ALLOW_INTEGER 8
95 #define UNIFY_ALLOW_OUTER_LEVEL 16
96 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
97 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
99 static void push_access_scope (tree);
100 static void pop_access_scope (tree);
101 static bool resolve_overloaded_unification (tree, tree, tree, tree,
102 unification_kind_t, int);
103 static int try_one_overload (tree, tree, tree, tree, tree,
104 unification_kind_t, int, bool);
105 static int unify (tree, tree, tree, tree, int);
106 static void add_pending_template (tree);
107 static int push_tinst_level (tree);
108 static void pop_tinst_level (void);
109 static tree reopen_tinst_level (struct tinst_level *);
110 static tree tsubst_initializer_list (tree, tree);
111 static tree get_class_bindings (tree, tree, tree);
112 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
114 static void tsubst_enum (tree, tree, tree);
115 static tree add_to_template_args (tree, tree);
116 static tree add_outermost_template_args (tree, tree);
117 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
118 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
120 static int type_unification_real (tree, tree, tree, tree,
121 int, unification_kind_t, int);
122 static void note_template_header (int);
123 static tree convert_nontype_argument_function (tree, tree);
124 static tree convert_nontype_argument (tree, tree);
125 static tree convert_template_argument (tree, tree, tree,
126 tsubst_flags_t, int, tree);
127 static int for_each_template_parm (tree, tree_fn_t, void*,
128 struct pointer_set_t*, bool);
129 static tree expand_template_argument_pack (tree);
130 static tree build_template_parm_index (int, int, int, tree, tree);
131 static bool inline_needs_template_parms (tree);
132 static void push_inline_template_parms_recursive (tree, int);
133 static tree retrieve_local_specialization (tree);
134 static void register_local_specialization (tree, tree);
135 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
136 static int mark_template_parm (tree, void *);
137 static int template_parm_this_level_p (tree, void *);
138 static tree tsubst_friend_function (tree, tree);
139 static tree tsubst_friend_class (tree, tree);
140 static int can_complete_type_without_circularity (tree);
141 static tree get_bindings (tree, tree, tree, bool);
142 static int template_decl_level (tree);
143 static int check_cv_quals_for_unify (int, tree, tree);
144 static void template_parm_level_and_index (tree, int*, int*);
145 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
146 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
147 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
148 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
149 static void regenerate_decl_from_template (tree, tree);
150 static tree most_specialized_class (tree, tree);
151 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
152 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
153 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
154 static bool check_specialization_scope (void);
155 static tree process_partial_specialization (tree);
156 static void set_current_access_from_decl (tree);
157 static tree get_template_base (tree, tree, tree, tree);
158 static tree try_class_unification (tree, tree, tree, tree);
159 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
161 static bool template_template_parm_bindings_ok_p (tree, tree);
162 static int template_args_equal (tree, tree);
163 static void tsubst_default_arguments (tree);
164 static tree for_each_template_parm_r (tree *, int *, void *);
165 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
166 static void copy_default_args_to_explicit_spec (tree);
167 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
168 static int eq_local_specializations (const void *, const void *);
169 static bool dependent_template_arg_p (tree);
170 static bool any_template_arguments_need_structural_equality_p (tree);
171 static bool dependent_type_p_r (tree);
172 static tree tsubst (tree, tree, tsubst_flags_t, tree);
173 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
174 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
175 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
177 /* Make the current scope suitable for access checking when we are
178 processing T. T can be FUNCTION_DECL for instantiated function
179 template, or VAR_DECL for static member variable (need by
180 instantiate_decl). */
183 push_access_scope (tree t)
185 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
186 || TREE_CODE (t) == VAR_DECL);
188 if (DECL_FRIEND_CONTEXT (t))
189 push_nested_class (DECL_FRIEND_CONTEXT (t));
190 else if (DECL_CLASS_SCOPE_P (t))
191 push_nested_class (DECL_CONTEXT (t));
193 push_to_top_level ();
195 if (TREE_CODE (t) == FUNCTION_DECL)
197 saved_access_scope = tree_cons
198 (NULL_TREE, current_function_decl, saved_access_scope);
199 current_function_decl = t;
203 /* Restore the scope set up by push_access_scope. T is the node we
207 pop_access_scope (tree t)
209 if (TREE_CODE (t) == FUNCTION_DECL)
211 current_function_decl = TREE_VALUE (saved_access_scope);
212 saved_access_scope = TREE_CHAIN (saved_access_scope);
215 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
218 pop_from_top_level ();
221 /* Do any processing required when DECL (a member template
222 declaration) is finished. Returns the TEMPLATE_DECL corresponding
223 to DECL, unless it is a specialization, in which case the DECL
224 itself is returned. */
227 finish_member_template_decl (tree decl)
229 if (decl == error_mark_node)
230 return error_mark_node;
232 gcc_assert (DECL_P (decl));
234 if (TREE_CODE (decl) == TYPE_DECL)
238 type = TREE_TYPE (decl);
239 if (type == error_mark_node)
240 return error_mark_node;
241 if (MAYBE_CLASS_TYPE_P (type)
242 && CLASSTYPE_TEMPLATE_INFO (type)
243 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
245 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
246 check_member_template (tmpl);
251 else if (TREE_CODE (decl) == FIELD_DECL)
252 error ("data member %qD cannot be a member template", decl);
253 else if (DECL_TEMPLATE_INFO (decl))
255 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
257 check_member_template (DECL_TI_TEMPLATE (decl));
258 return DECL_TI_TEMPLATE (decl);
264 error ("invalid member template declaration %qD", decl);
266 return error_mark_node;
269 /* Return the template info node corresponding to T, whatever T is. */
272 get_template_info (tree t)
274 tree tinfo = NULL_TREE;
276 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
277 tinfo = DECL_TEMPLATE_INFO (t);
279 if (!tinfo && TREE_CODE (t) == TYPE_DECL)
282 if (TAGGED_TYPE_P (t))
283 tinfo = TYPE_TEMPLATE_INFO (t);
288 /* Returns the template nesting level of the indicated class TYPE.
298 A<T>::B<U> has depth two, while A<T> has depth one.
299 Both A<T>::B<int> and A<int>::B<U> have depth one, if
300 they are instantiations, not specializations.
302 This function is guaranteed to return 0 if passed NULL_TREE so
303 that, for example, `template_class_depth (current_class_type)' is
307 template_class_depth (tree type)
312 type && TREE_CODE (type) != NAMESPACE_DECL;
313 type = (TREE_CODE (type) == FUNCTION_DECL)
314 ? CP_DECL_CONTEXT (type) : TYPE_CONTEXT (type))
316 tree tinfo = get_template_info (type);
318 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
319 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
326 /* Subroutine of maybe_begin_member_template_processing.
327 Returns true if processing DECL needs us to push template parms. */
330 inline_needs_template_parms (tree decl)
332 if (! DECL_TEMPLATE_INFO (decl))
335 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
336 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
339 /* Subroutine of maybe_begin_member_template_processing.
340 Push the template parms in PARMS, starting from LEVELS steps into the
341 chain, and ending at the beginning, since template parms are listed
345 push_inline_template_parms_recursive (tree parmlist, int levels)
347 tree parms = TREE_VALUE (parmlist);
351 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
353 ++processing_template_decl;
354 current_template_parms
355 = tree_cons (size_int (processing_template_decl),
356 parms, current_template_parms);
357 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
359 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
361 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
363 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
365 if (parm == error_mark_node)
368 gcc_assert (DECL_P (parm));
370 switch (TREE_CODE (parm))
379 /* Make a CONST_DECL as is done in process_template_parm.
380 It is ugly that we recreate this here; the original
381 version built in process_template_parm is no longer
383 tree decl = build_decl (CONST_DECL, DECL_NAME (parm),
385 DECL_ARTIFICIAL (decl) = 1;
386 TREE_CONSTANT (decl) = 1;
387 TREE_READONLY (decl) = 1;
388 DECL_INITIAL (decl) = DECL_INITIAL (parm);
389 SET_DECL_TEMPLATE_PARM_P (decl);
400 /* Restore the template parameter context for a member template or
401 a friend template defined in a class definition. */
404 maybe_begin_member_template_processing (tree decl)
409 if (inline_needs_template_parms (decl))
411 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
412 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
414 if (DECL_TEMPLATE_SPECIALIZATION (decl))
417 parms = TREE_CHAIN (parms);
420 push_inline_template_parms_recursive (parms, levels);
423 /* Remember how many levels of template parameters we pushed so that
424 we can pop them later. */
425 VEC_safe_push (int, heap, inline_parm_levels, levels);
428 /* Undo the effects of maybe_begin_member_template_processing. */
431 maybe_end_member_template_processing (void)
436 if (VEC_length (int, inline_parm_levels) == 0)
439 last = VEC_pop (int, inline_parm_levels);
440 for (i = 0; i < last; ++i)
442 --processing_template_decl;
443 current_template_parms = TREE_CHAIN (current_template_parms);
448 /* Return a new template argument vector which contains all of ARGS,
449 but has as its innermost set of arguments the EXTRA_ARGS. */
452 add_to_template_args (tree args, tree extra_args)
459 extra_depth = TMPL_ARGS_DEPTH (extra_args);
460 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
462 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
463 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
465 for (j = 1; j <= extra_depth; ++j, ++i)
466 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
471 /* Like add_to_template_args, but only the outermost ARGS are added to
472 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
473 (EXTRA_ARGS) levels are added. This function is used to combine
474 the template arguments from a partial instantiation with the
475 template arguments used to attain the full instantiation from the
476 partial instantiation. */
479 add_outermost_template_args (tree args, tree extra_args)
483 /* If there are more levels of EXTRA_ARGS than there are ARGS,
484 something very fishy is going on. */
485 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
487 /* If *all* the new arguments will be the EXTRA_ARGS, just return
489 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
492 /* For the moment, we make ARGS look like it contains fewer levels. */
493 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
495 new_args = add_to_template_args (args, extra_args);
497 /* Now, we restore ARGS to its full dimensions. */
498 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
503 /* Return the N levels of innermost template arguments from the ARGS. */
506 get_innermost_template_args (tree args, int n)
514 /* If N is 1, just return the innermost set of template arguments. */
516 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
518 /* If we're not removing anything, just return the arguments we were
520 extra_levels = TMPL_ARGS_DEPTH (args) - n;
521 gcc_assert (extra_levels >= 0);
522 if (extra_levels == 0)
525 /* Make a new set of arguments, not containing the outer arguments. */
526 new_args = make_tree_vec (n);
527 for (i = 1; i <= n; ++i)
528 SET_TMPL_ARGS_LEVEL (new_args, i,
529 TMPL_ARGS_LEVEL (args, i + extra_levels));
534 /* The inverse of get_innermost_template_args: Return all but the innermost
535 EXTRA_LEVELS levels of template arguments from the ARGS. */
538 strip_innermost_template_args (tree args, int extra_levels)
541 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
546 /* If N is 1, just return the outermost set of template arguments. */
548 return TMPL_ARGS_LEVEL (args, 1);
550 /* If we're not removing anything, just return the arguments we were
552 gcc_assert (extra_levels >= 0);
553 if (extra_levels == 0)
556 /* Make a new set of arguments, not containing the inner arguments. */
557 new_args = make_tree_vec (n);
558 for (i = 1; i <= n; ++i)
559 SET_TMPL_ARGS_LEVEL (new_args, i,
560 TMPL_ARGS_LEVEL (args, i));
565 /* We've got a template header coming up; push to a new level for storing
569 begin_template_parm_list (void)
571 /* We use a non-tag-transparent scope here, which causes pushtag to
572 put tags in this scope, rather than in the enclosing class or
573 namespace scope. This is the right thing, since we want
574 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
575 global template class, push_template_decl handles putting the
576 TEMPLATE_DECL into top-level scope. For a nested template class,
579 template <class T> struct S1 {
580 template <class T> struct S2 {};
583 pushtag contains special code to call pushdecl_with_scope on the
584 TEMPLATE_DECL for S2. */
585 begin_scope (sk_template_parms, NULL);
586 ++processing_template_decl;
587 ++processing_template_parmlist;
588 note_template_header (0);
591 /* This routine is called when a specialization is declared. If it is
592 invalid to declare a specialization here, an error is reported and
593 false is returned, otherwise this routine will return true. */
596 check_specialization_scope (void)
598 tree scope = current_scope ();
602 An explicit specialization shall be declared in the namespace of
603 which the template is a member, or, for member templates, in the
604 namespace of which the enclosing class or enclosing class
605 template is a member. An explicit specialization of a member
606 function, member class or static data member of a class template
607 shall be declared in the namespace of which the class template
609 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
611 error ("explicit specialization in non-namespace scope %qD", scope);
617 In an explicit specialization declaration for a member of a class
618 template or a member template that appears in namespace scope,
619 the member template and some of its enclosing class templates may
620 remain unspecialized, except that the declaration shall not
621 explicitly specialize a class member template if its enclosing
622 class templates are not explicitly specialized as well. */
623 if (current_template_parms)
625 error ("enclosing class templates are not explicitly specialized");
632 /* We've just seen template <>. */
635 begin_specialization (void)
637 begin_scope (sk_template_spec, NULL);
638 note_template_header (1);
639 return check_specialization_scope ();
642 /* Called at then end of processing a declaration preceded by
646 end_specialization (void)
649 reset_specialization ();
652 /* Any template <>'s that we have seen thus far are not referring to a
653 function specialization. */
656 reset_specialization (void)
658 processing_specialization = 0;
659 template_header_count = 0;
662 /* We've just seen a template header. If SPECIALIZATION is nonzero,
663 it was of the form template <>. */
666 note_template_header (int specialization)
668 processing_specialization = specialization;
669 template_header_count++;
672 /* We're beginning an explicit instantiation. */
675 begin_explicit_instantiation (void)
677 gcc_assert (!processing_explicit_instantiation);
678 processing_explicit_instantiation = true;
683 end_explicit_instantiation (void)
685 gcc_assert (processing_explicit_instantiation);
686 processing_explicit_instantiation = false;
689 /* An explicit specialization or partial specialization TMPL is being
690 declared. Check that the namespace in which the specialization is
691 occurring is permissible. Returns false iff it is invalid to
692 specialize TMPL in the current namespace. */
695 check_specialization_namespace (tree tmpl)
697 tree tpl_ns = decl_namespace_context (tmpl);
701 An explicit specialization shall be declared in the namespace of
702 which the template is a member, or, for member templates, in the
703 namespace of which the enclosing class or enclosing class
704 template is a member. An explicit specialization of a member
705 function, member class or static data member of a class template
706 shall be declared in the namespace of which the class template is
708 if (is_associated_namespace (current_namespace, tpl_ns))
709 /* Same or super-using namespace. */
713 permerror (input_location, "specialization of %qD in different namespace", tmpl);
714 permerror (input_location, " from definition of %q+#D", tmpl);
719 /* SPEC is an explicit instantiation. Check that it is valid to
720 perform this explicit instantiation in the current namespace. */
723 check_explicit_instantiation_namespace (tree spec)
727 /* DR 275: An explicit instantiation shall appear in an enclosing
728 namespace of its template. */
729 ns = decl_namespace_context (spec);
730 if (!is_ancestor (current_namespace, ns))
731 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
732 "(which does not enclose namespace %qD)",
733 spec, current_namespace, ns);
736 /* The TYPE is being declared. If it is a template type, that means it
737 is a partial specialization. Do appropriate error-checking. */
740 maybe_process_partial_specialization (tree type)
744 if (type == error_mark_node)
745 return error_mark_node;
747 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
749 error ("name of class shadows template template parameter %qD",
751 return error_mark_node;
754 context = TYPE_CONTEXT (type);
756 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
758 /* This is for ordinary explicit specialization and partial
759 specialization of a template class such as:
761 template <> class C<int>;
765 template <class T> class C<T*>;
767 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
769 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
770 && !COMPLETE_TYPE_P (type))
772 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
773 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
774 if (processing_template_decl)
776 if (push_template_decl (TYPE_MAIN_DECL (type))
778 return error_mark_node;
781 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
782 error ("specialization of %qT after instantiation", type);
784 else if (CLASS_TYPE_P (type)
785 && !CLASSTYPE_USE_TEMPLATE (type)
786 && CLASSTYPE_TEMPLATE_INFO (type)
787 && context && CLASS_TYPE_P (context)
788 && CLASSTYPE_TEMPLATE_INFO (context))
790 /* This is for an explicit specialization of member class
791 template according to [temp.expl.spec/18]:
793 template <> template <class U> class C<int>::D;
795 The context `C<int>' must be an implicit instantiation.
796 Otherwise this is just a member class template declared
799 template <> class C<int> { template <class U> class D; };
800 template <> template <class U> class C<int>::D;
802 In the first case, `C<int>::D' is a specialization of `C<T>::D'
803 while in the second case, `C<int>::D' is a primary template
804 and `C<T>::D' may not exist. */
806 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
807 && !COMPLETE_TYPE_P (type))
811 if (current_namespace
812 != decl_namespace_context (CLASSTYPE_TI_TEMPLATE (type)))
814 permerror (input_location, "specializing %q#T in different namespace", type);
815 permerror (input_location, " from definition of %q+#D",
816 CLASSTYPE_TI_TEMPLATE (type));
819 /* Check for invalid specialization after instantiation:
821 template <> template <> class C<int>::D<int>;
822 template <> template <class U> class C<int>::D; */
824 for (t = DECL_TEMPLATE_INSTANTIATIONS
825 (most_general_template (CLASSTYPE_TI_TEMPLATE (type)));
826 t; t = TREE_CHAIN (t))
827 if (TREE_VALUE (t) != type
828 && TYPE_CONTEXT (TREE_VALUE (t)) == context)
829 error ("specialization %qT after instantiation %qT",
830 type, TREE_VALUE (t));
832 /* Mark TYPE as a specialization. And as a result, we only
833 have one level of template argument for the innermost
835 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
836 CLASSTYPE_TI_ARGS (type)
837 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
840 else if (processing_specialization)
842 error ("explicit specialization of non-template %qT", type);
843 return error_mark_node;
849 /* Returns nonzero if we can optimize the retrieval of specializations
850 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
851 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
854 optimize_specialization_lookup_p (tree tmpl)
856 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
857 && DECL_CLASS_SCOPE_P (tmpl)
858 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
860 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
861 /* The optimized lookup depends on the fact that the
862 template arguments for the member function template apply
863 purely to the containing class, which is not true if the
864 containing class is an explicit or partial
866 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
867 && !DECL_MEMBER_TEMPLATE_P (tmpl)
868 && !DECL_CONV_FN_P (tmpl)
869 /* It is possible to have a template that is not a member
870 template and is not a member of a template class:
872 template <typename T>
873 struct S { friend A::f(); };
875 Here, the friend function is a template, but the context does
876 not have template information. The optimized lookup relies
877 on having ARGS be the template arguments for both the class
878 and the function template. */
879 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
882 /* Retrieve the specialization (in the sense of [temp.spec] - a
883 specialization is either an instantiation or an explicit
884 specialization) of TMPL for the given template ARGS. If there is
885 no such specialization, return NULL_TREE. The ARGS are a vector of
886 arguments, or a vector of vectors of arguments, in the case of
887 templates with more than one level of parameters.
889 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
890 then we search for a partial specialization matching ARGS. This
891 parameter is ignored if TMPL is not a class template. */
894 retrieve_specialization (tree tmpl, tree args,
895 bool class_specializations_p)
897 if (args == error_mark_node)
900 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
902 /* There should be as many levels of arguments as there are
903 levels of parameters. */
904 gcc_assert (TMPL_ARGS_DEPTH (args)
905 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
907 if (optimize_specialization_lookup_p (tmpl))
910 tree class_specialization;
911 VEC(tree,gc) *methods;
915 /* The template arguments actually apply to the containing
916 class. Find the class specialization with those
918 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
920 = retrieve_specialization (class_template, args,
921 /*class_specializations_p=*/false);
922 if (!class_specialization)
924 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
925 for the specialization. */
926 idx = class_method_index_for_fn (class_specialization, tmpl);
929 /* Iterate through the methods with the indicated name, looking
930 for the one that has an instance of TMPL. */
931 methods = CLASSTYPE_METHOD_VEC (class_specialization);
932 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
934 tree fn = OVL_CURRENT (fns);
935 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl)
945 /* Class templates store their instantiations on the
946 DECL_TEMPLATE_INSTANTIATIONS list; other templates use the
947 DECL_TEMPLATE_SPECIALIZATIONS list. */
948 if (!class_specializations_p
949 && TREE_CODE (DECL_TEMPLATE_RESULT (tmpl)) == TYPE_DECL
950 && TAGGED_TYPE_P (TREE_TYPE (tmpl)))
951 sp = &DECL_TEMPLATE_INSTANTIATIONS (tmpl);
953 sp = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
955 /* Iterate through the list until we find a matching template. */
956 while (*sp != NULL_TREE)
960 if (comp_template_args (TREE_PURPOSE (spec), args))
962 /* Use the move-to-front heuristic to speed up future
966 *sp = TREE_CHAIN (*sp);
967 TREE_CHAIN (spec) = *head;
970 return TREE_VALUE (spec);
972 sp = &TREE_CHAIN (spec);
979 /* Like retrieve_specialization, but for local declarations. */
982 retrieve_local_specialization (tree tmpl)
986 if (local_specializations == NULL)
989 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
990 htab_hash_pointer (tmpl));
991 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
994 /* Returns nonzero iff DECL is a specialization of TMPL. */
997 is_specialization_of (tree decl, tree tmpl)
1001 if (TREE_CODE (decl) == FUNCTION_DECL)
1005 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1011 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1013 for (t = TREE_TYPE (decl);
1015 t = CLASSTYPE_USE_TEMPLATE (t)
1016 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1017 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1024 /* Returns nonzero iff DECL is a specialization of friend declaration
1025 FRIEND_DECL according to [temp.friend]. */
1028 is_specialization_of_friend (tree decl, tree friend_decl)
1030 bool need_template = true;
1033 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1034 || TREE_CODE (decl) == TYPE_DECL);
1036 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1037 of a template class, we want to check if DECL is a specialization
1039 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1040 && DECL_TEMPLATE_INFO (friend_decl)
1041 && !DECL_USE_TEMPLATE (friend_decl))
1043 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1044 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1045 need_template = false;
1047 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1048 && !PRIMARY_TEMPLATE_P (friend_decl))
1049 need_template = false;
1051 /* There is nothing to do if this is not a template friend. */
1052 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1055 if (is_specialization_of (decl, friend_decl))
1059 A member of a class template may be declared to be a friend of a
1060 non-template class. In this case, the corresponding member of
1061 every specialization of the class template is a friend of the
1062 class granting friendship.
1064 For example, given a template friend declaration
1066 template <class T> friend void A<T>::f();
1068 the member function below is considered a friend
1070 template <> struct A<int> {
1074 For this type of template friend, TEMPLATE_DEPTH below will be
1075 nonzero. To determine if DECL is a friend of FRIEND, we first
1076 check if the enclosing class is a specialization of another. */
1078 template_depth = template_class_depth (DECL_CONTEXT (friend_decl));
1080 && DECL_CLASS_SCOPE_P (decl)
1081 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1082 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1084 /* Next, we check the members themselves. In order to handle
1085 a few tricky cases, such as when FRIEND_DECL's are
1087 template <class T> friend void A<T>::g(T t);
1088 template <class T> template <T t> friend void A<T>::h();
1092 void A<int>::g(int);
1093 template <int> void A<int>::h();
1095 we need to figure out ARGS, the template arguments from
1096 the context of DECL. This is required for template substitution
1097 of `T' in the function parameter of `g' and template parameter
1098 of `h' in the above examples. Here ARGS corresponds to `int'. */
1100 tree context = DECL_CONTEXT (decl);
1101 tree args = NULL_TREE;
1102 int current_depth = 0;
1104 while (current_depth < template_depth)
1106 if (CLASSTYPE_TEMPLATE_INFO (context))
1108 if (current_depth == 0)
1109 args = TYPE_TI_ARGS (context);
1111 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1114 context = TYPE_CONTEXT (context);
1117 if (TREE_CODE (decl) == FUNCTION_DECL)
1122 tree friend_args_type;
1123 tree decl_args_type;
1125 /* Make sure that both DECL and FRIEND_DECL are templates or
1127 is_template = DECL_TEMPLATE_INFO (decl)
1128 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1129 if (need_template ^ is_template)
1131 else if (is_template)
1133 /* If both are templates, check template parameter list. */
1135 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1137 if (!comp_template_parms
1138 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1142 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1145 decl_type = TREE_TYPE (decl);
1147 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1148 tf_none, NULL_TREE);
1149 if (friend_type == error_mark_node)
1152 /* Check if return types match. */
1153 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1156 /* Check if function parameter types match, ignoring the
1157 `this' parameter. */
1158 friend_args_type = TYPE_ARG_TYPES (friend_type);
1159 decl_args_type = TYPE_ARG_TYPES (decl_type);
1160 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1161 friend_args_type = TREE_CHAIN (friend_args_type);
1162 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1163 decl_args_type = TREE_CHAIN (decl_args_type);
1165 return compparms (decl_args_type, friend_args_type);
1169 /* DECL is a TYPE_DECL */
1171 tree decl_type = TREE_TYPE (decl);
1173 /* Make sure that both DECL and FRIEND_DECL are templates or
1176 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1177 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1179 if (need_template ^ is_template)
1181 else if (is_template)
1184 /* If both are templates, check the name of the two
1185 TEMPLATE_DECL's first because is_friend didn't. */
1186 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1187 != DECL_NAME (friend_decl))
1190 /* Now check template parameter list. */
1192 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1194 return comp_template_parms
1195 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1199 return (DECL_NAME (decl)
1200 == DECL_NAME (friend_decl));
1206 /* Register the specialization SPEC as a specialization of TMPL with
1207 the indicated ARGS. IS_FRIEND indicates whether the specialization
1208 is actually just a friend declaration. Returns SPEC, or an
1209 equivalent prior declaration, if available. */
1212 register_specialization (tree spec, tree tmpl, tree args, bool is_friend)
1216 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1218 if (TREE_CODE (spec) == FUNCTION_DECL
1219 && uses_template_parms (DECL_TI_ARGS (spec)))
1220 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1221 register it; we want the corresponding TEMPLATE_DECL instead.
1222 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1223 the more obvious `uses_template_parms (spec)' to avoid problems
1224 with default function arguments. In particular, given
1225 something like this:
1227 template <class T> void f(T t1, T t = T())
1229 the default argument expression is not substituted for in an
1230 instantiation unless and until it is actually needed. */
1233 fn = retrieve_specialization (tmpl, args,
1234 /*class_specializations_p=*/false);
1235 /* We can sometimes try to re-register a specialization that we've
1236 already got. In particular, regenerate_decl_from_template calls
1237 duplicate_decls which will update the specialization list. But,
1238 we'll still get called again here anyhow. It's more convenient
1239 to simply allow this than to try to prevent it. */
1242 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1244 if (DECL_TEMPLATE_INSTANTIATION (fn))
1247 || DECL_EXPLICIT_INSTANTIATION (fn))
1249 error ("specialization of %qD after instantiation",
1251 return error_mark_node;
1256 /* This situation should occur only if the first
1257 specialization is an implicit instantiation, the
1258 second is an explicit specialization, and the
1259 implicit instantiation has not yet been used. That
1260 situation can occur if we have implicitly
1261 instantiated a member function and then specialized
1264 We can also wind up here if a friend declaration that
1265 looked like an instantiation turns out to be a
1268 template <class T> void foo(T);
1269 class S { friend void foo<>(int) };
1270 template <> void foo(int);
1272 We transform the existing DECL in place so that any
1273 pointers to it become pointers to the updated
1276 If there was a definition for the template, but not
1277 for the specialization, we want this to look as if
1278 there were no definition, and vice versa. */
1279 DECL_INITIAL (fn) = NULL_TREE;
1280 duplicate_decls (spec, fn, is_friend);
1281 /* The call to duplicate_decls will have applied
1284 An explicit specialization of a function template
1285 is inline only if it is explicitly declared to be,
1286 and independently of whether its function template
1289 to the primary function; now copy the inline bits to
1290 the various clones. */
1291 FOR_EACH_CLONE (clone, fn)
1292 DECL_DECLARED_INLINE_P (clone)
1293 = DECL_DECLARED_INLINE_P (fn);
1294 check_specialization_namespace (fn);
1299 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1301 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1302 /* Dup decl failed, but this is a new definition. Set the
1303 line number so any errors match this new
1305 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1311 /* A specialization must be declared in the same namespace as the
1312 template it is specializing. */
1313 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1314 && !check_specialization_namespace (tmpl))
1315 DECL_CONTEXT (spec) = FROB_CONTEXT (decl_namespace_context (tmpl));
1317 if (!optimize_specialization_lookup_p (tmpl))
1318 DECL_TEMPLATE_SPECIALIZATIONS (tmpl)
1319 = tree_cons (args, spec, DECL_TEMPLATE_SPECIALIZATIONS (tmpl));
1324 /* Unregister the specialization SPEC as a specialization of TMPL.
1325 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1326 if the SPEC was listed as a specialization of TMPL. */
1329 reregister_specialization (tree spec, tree tmpl, tree new_spec)
1333 for (s = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
1335 s = &TREE_CHAIN (*s))
1336 if (TREE_VALUE (*s) == spec)
1339 *s = TREE_CHAIN (*s);
1341 TREE_VALUE (*s) = new_spec;
1348 /* Compare an entry in the local specializations hash table P1 (which
1349 is really a pointer to a TREE_LIST) with P2 (which is really a
1353 eq_local_specializations (const void *p1, const void *p2)
1355 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1358 /* Hash P1, an entry in the local specializations table. */
1361 hash_local_specialization (const void* p1)
1363 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1366 /* Like register_specialization, but for local declarations. We are
1367 registering SPEC, an instantiation of TMPL. */
1370 register_local_specialization (tree spec, tree tmpl)
1374 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1375 htab_hash_pointer (tmpl), INSERT);
1376 *slot = build_tree_list (spec, tmpl);
1379 /* TYPE is a class type. Returns true if TYPE is an explicitly
1380 specialized class. */
1383 explicit_class_specialization_p (tree type)
1385 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1387 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1390 /* Print the list of candidate FNS in an error message. */
1393 print_candidates (tree fns)
1397 const char *str = "candidates are:";
1399 for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
1403 for (f = TREE_VALUE (fn); f; f = OVL_NEXT (f))
1404 error ("%s %+#D", str, OVL_CURRENT (f));
1409 /* Returns the template (one of the functions given by TEMPLATE_ID)
1410 which can be specialized to match the indicated DECL with the
1411 explicit template args given in TEMPLATE_ID. The DECL may be
1412 NULL_TREE if none is available. In that case, the functions in
1413 TEMPLATE_ID are non-members.
1415 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1416 specialization of a member template.
1418 The TEMPLATE_COUNT is the number of references to qualifying
1419 template classes that appeared in the name of the function. See
1420 check_explicit_specialization for a more accurate description.
1422 TSK indicates what kind of template declaration (if any) is being
1423 declared. TSK_TEMPLATE indicates that the declaration given by
1424 DECL, though a FUNCTION_DECL, has template parameters, and is
1425 therefore a template function.
1427 The template args (those explicitly specified and those deduced)
1428 are output in a newly created vector *TARGS_OUT.
1430 If it is impossible to determine the result, an error message is
1431 issued. The error_mark_node is returned to indicate failure. */
1434 determine_specialization (tree template_id,
1437 int need_member_template,
1443 tree explicit_targs;
1444 tree candidates = NULL_TREE;
1445 /* A TREE_LIST of templates of which DECL may be a specialization.
1446 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1447 corresponding TREE_PURPOSE is the set of template arguments that,
1448 when used to instantiate the template, would produce a function
1449 with the signature of DECL. */
1450 tree templates = NULL_TREE;
1452 struct cp_binding_level *b;
1454 *targs_out = NULL_TREE;
1456 if (template_id == error_mark_node || decl == error_mark_node)
1457 return error_mark_node;
1459 fns = TREE_OPERAND (template_id, 0);
1460 explicit_targs = TREE_OPERAND (template_id, 1);
1462 if (fns == error_mark_node)
1463 return error_mark_node;
1465 /* Check for baselinks. */
1466 if (BASELINK_P (fns))
1467 fns = BASELINK_FUNCTIONS (fns);
1469 if (!is_overloaded_fn (fns))
1471 error ("%qD is not a function template", fns);
1472 return error_mark_node;
1475 /* Count the number of template headers specified for this
1478 for (b = current_binding_level;
1479 b->kind == sk_template_parms;
1483 for (; fns; fns = OVL_NEXT (fns))
1485 tree fn = OVL_CURRENT (fns);
1487 if (TREE_CODE (fn) == TEMPLATE_DECL)
1489 tree decl_arg_types;
1492 /* In case of explicit specialization, we need to check if
1493 the number of template headers appearing in the specialization
1494 is correct. This is usually done in check_explicit_specialization,
1495 but the check done there cannot be exhaustive when specializing
1496 member functions. Consider the following code:
1498 template <> void A<int>::f(int);
1499 template <> template <> void A<int>::f(int);
1501 Assuming that A<int> is not itself an explicit specialization
1502 already, the first line specializes "f" which is a non-template
1503 member function, whilst the second line specializes "f" which
1504 is a template member function. So both lines are syntactically
1505 correct, and check_explicit_specialization does not reject
1508 Here, we can do better, as we are matching the specialization
1509 against the declarations. We count the number of template
1510 headers, and we check if they match TEMPLATE_COUNT + 1
1511 (TEMPLATE_COUNT is the number of qualifying template classes,
1512 plus there must be another header for the member template
1515 Notice that if header_count is zero, this is not a
1516 specialization but rather a template instantiation, so there
1517 is no check we can perform here. */
1518 if (header_count && header_count != template_count + 1)
1521 /* Check that the number of template arguments at the
1522 innermost level for DECL is the same as for FN. */
1523 if (current_binding_level->kind == sk_template_parms
1524 && !current_binding_level->explicit_spec_p
1525 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1526 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1527 (current_template_parms))))
1530 /* DECL might be a specialization of FN. */
1531 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1532 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1534 /* For a non-static member function, we need to make sure
1535 that the const qualification is the same. Since
1536 get_bindings does not try to merge the "this" parameter,
1537 we must do the comparison explicitly. */
1538 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1539 && !same_type_p (TREE_VALUE (fn_arg_types),
1540 TREE_VALUE (decl_arg_types)))
1543 /* Skip the "this" parameter and, for constructors of
1544 classes with virtual bases, the VTT parameter. A
1545 full specialization of a constructor will have a VTT
1546 parameter, but a template never will. */
1548 = skip_artificial_parms_for (decl, decl_arg_types);
1550 = skip_artificial_parms_for (fn, fn_arg_types);
1552 /* Check that the number of function parameters matches.
1554 template <class T> void f(int i = 0);
1555 template <> void f<int>();
1556 The specialization f<int> is invalid but is not caught
1557 by get_bindings below. */
1558 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1561 /* Function templates cannot be specializations; there are
1562 no partial specializations of functions. Therefore, if
1563 the type of DECL does not match FN, there is no
1565 if (tsk == tsk_template)
1567 if (compparms (fn_arg_types, decl_arg_types))
1568 candidates = tree_cons (NULL_TREE, fn, candidates);
1572 /* See whether this function might be a specialization of this
1574 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1577 /* We cannot deduce template arguments that when used to
1578 specialize TMPL will produce DECL. */
1581 /* Save this template, and the arguments deduced. */
1582 templates = tree_cons (targs, fn, templates);
1584 else if (need_member_template)
1585 /* FN is an ordinary member function, and we need a
1586 specialization of a member template. */
1588 else if (TREE_CODE (fn) != FUNCTION_DECL)
1589 /* We can get IDENTIFIER_NODEs here in certain erroneous
1592 else if (!DECL_FUNCTION_MEMBER_P (fn))
1593 /* This is just an ordinary non-member function. Nothing can
1594 be a specialization of that. */
1596 else if (DECL_ARTIFICIAL (fn))
1597 /* Cannot specialize functions that are created implicitly. */
1601 tree decl_arg_types;
1603 /* This is an ordinary member function. However, since
1604 we're here, we can assume it's enclosing class is a
1605 template class. For example,
1607 template <typename T> struct S { void f(); };
1608 template <> void S<int>::f() {}
1610 Here, S<int>::f is a non-template, but S<int> is a
1611 template class. If FN has the same type as DECL, we
1612 might be in business. */
1614 if (!DECL_TEMPLATE_INFO (fn))
1615 /* Its enclosing class is an explicit specialization
1616 of a template class. This is not a candidate. */
1619 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1620 TREE_TYPE (TREE_TYPE (fn))))
1621 /* The return types differ. */
1624 /* Adjust the type of DECL in case FN is a static member. */
1625 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1626 if (DECL_STATIC_FUNCTION_P (fn)
1627 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1628 decl_arg_types = TREE_CHAIN (decl_arg_types);
1630 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1633 candidates = tree_cons (NULL_TREE, fn, candidates);
1637 if (templates && TREE_CHAIN (templates))
1643 It is possible for a specialization with a given function
1644 signature to be instantiated from more than one function
1645 template. In such cases, explicit specification of the
1646 template arguments must be used to uniquely identify the
1647 function template specialization being specialized.
1649 Note that here, there's no suggestion that we're supposed to
1650 determine which of the candidate templates is most
1651 specialized. However, we, also have:
1655 Partial ordering of overloaded function template
1656 declarations is used in the following contexts to select
1657 the function template to which a function template
1658 specialization refers:
1660 -- when an explicit specialization refers to a function
1663 So, we do use the partial ordering rules, at least for now.
1664 This extension can only serve to make invalid programs valid,
1665 so it's safe. And, there is strong anecdotal evidence that
1666 the committee intended the partial ordering rules to apply;
1667 the EDG front end has that behavior, and John Spicer claims
1668 that the committee simply forgot to delete the wording in
1669 [temp.expl.spec]. */
1670 tree tmpl = most_specialized_instantiation (templates);
1671 if (tmpl != error_mark_node)
1674 TREE_CHAIN (templates) = NULL_TREE;
1678 if (templates == NULL_TREE && candidates == NULL_TREE)
1680 error ("template-id %qD for %q+D does not match any template "
1681 "declaration", template_id, decl);
1682 return error_mark_node;
1684 else if ((templates && TREE_CHAIN (templates))
1685 || (candidates && TREE_CHAIN (candidates))
1686 || (templates && candidates))
1688 error ("ambiguous template specialization %qD for %q+D",
1690 chainon (candidates, templates);
1691 print_candidates (candidates);
1692 return error_mark_node;
1695 /* We have one, and exactly one, match. */
1698 tree fn = TREE_VALUE (candidates);
1699 /* DECL is a re-declaration of a template function. */
1700 if (TREE_CODE (fn) == TEMPLATE_DECL)
1702 /* It was a specialization of an ordinary member function in a
1704 *targs_out = copy_node (DECL_TI_ARGS (fn));
1705 return DECL_TI_TEMPLATE (fn);
1708 /* It was a specialization of a template. */
1709 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1710 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1712 *targs_out = copy_node (targs);
1713 SET_TMPL_ARGS_LEVEL (*targs_out,
1714 TMPL_ARGS_DEPTH (*targs_out),
1715 TREE_PURPOSE (templates));
1718 *targs_out = TREE_PURPOSE (templates);
1719 return TREE_VALUE (templates);
1722 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1723 but with the default argument values filled in from those in the
1727 copy_default_args_to_explicit_spec_1 (tree spec_types,
1730 tree new_spec_types;
1735 if (spec_types == void_list_node)
1736 return void_list_node;
1738 /* Substitute into the rest of the list. */
1740 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
1741 TREE_CHAIN (tmpl_types));
1743 /* Add the default argument for this parameter. */
1744 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
1745 TREE_VALUE (spec_types),
1749 /* DECL is an explicit specialization. Replicate default arguments
1750 from the template it specializes. (That way, code like:
1752 template <class T> void f(T = 3);
1753 template <> void f(double);
1756 works, as required.) An alternative approach would be to look up
1757 the correct default arguments at the call-site, but this approach
1758 is consistent with how implicit instantiations are handled. */
1761 copy_default_args_to_explicit_spec (tree decl)
1766 tree new_spec_types;
1770 tree object_type = NULL_TREE;
1771 tree in_charge = NULL_TREE;
1772 tree vtt = NULL_TREE;
1774 /* See if there's anything we need to do. */
1775 tmpl = DECL_TI_TEMPLATE (decl);
1776 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
1777 for (t = tmpl_types; t; t = TREE_CHAIN (t))
1778 if (TREE_PURPOSE (t))
1783 old_type = TREE_TYPE (decl);
1784 spec_types = TYPE_ARG_TYPES (old_type);
1786 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1788 /* Remove the this pointer, but remember the object's type for
1790 object_type = TREE_TYPE (TREE_VALUE (spec_types));
1791 spec_types = TREE_CHAIN (spec_types);
1792 tmpl_types = TREE_CHAIN (tmpl_types);
1794 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
1796 /* DECL may contain more parameters than TMPL due to the extra
1797 in-charge parameter in constructors and destructors. */
1798 in_charge = spec_types;
1799 spec_types = TREE_CHAIN (spec_types);
1801 if (DECL_HAS_VTT_PARM_P (decl))
1804 spec_types = TREE_CHAIN (spec_types);
1808 /* Compute the merged default arguments. */
1810 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
1812 /* Compute the new FUNCTION_TYPE. */
1816 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
1821 /* Put the in-charge parameter back. */
1822 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
1823 TREE_VALUE (in_charge),
1826 new_type = build_method_type_directly (object_type,
1827 TREE_TYPE (old_type),
1831 new_type = build_function_type (TREE_TYPE (old_type),
1833 new_type = cp_build_type_attribute_variant (new_type,
1834 TYPE_ATTRIBUTES (old_type));
1835 new_type = build_exception_variant (new_type,
1836 TYPE_RAISES_EXCEPTIONS (old_type));
1837 TREE_TYPE (decl) = new_type;
1840 /* Check to see if the function just declared, as indicated in
1841 DECLARATOR, and in DECL, is a specialization of a function
1842 template. We may also discover that the declaration is an explicit
1843 instantiation at this point.
1845 Returns DECL, or an equivalent declaration that should be used
1846 instead if all goes well. Issues an error message if something is
1847 amiss. Returns error_mark_node if the error is not easily
1850 FLAGS is a bitmask consisting of the following flags:
1852 2: The function has a definition.
1853 4: The function is a friend.
1855 The TEMPLATE_COUNT is the number of references to qualifying
1856 template classes that appeared in the name of the function. For
1859 template <class T> struct S { void f(); };
1862 the TEMPLATE_COUNT would be 1. However, explicitly specialized
1863 classes are not counted in the TEMPLATE_COUNT, so that in
1865 template <class T> struct S {};
1866 template <> struct S<int> { void f(); }
1867 template <> void S<int>::f();
1869 the TEMPLATE_COUNT would be 0. (Note that this declaration is
1870 invalid; there should be no template <>.)
1872 If the function is a specialization, it is marked as such via
1873 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
1874 is set up correctly, and it is added to the list of specializations
1875 for that template. */
1878 check_explicit_specialization (tree declarator,
1883 int have_def = flags & 2;
1884 int is_friend = flags & 4;
1885 int specialization = 0;
1886 int explicit_instantiation = 0;
1887 int member_specialization = 0;
1888 tree ctype = DECL_CLASS_CONTEXT (decl);
1889 tree dname = DECL_NAME (decl);
1894 if (!processing_specialization)
1897 tsk = tsk_excessive_parms;
1900 tsk = current_tmpl_spec_kind (template_count);
1905 if (processing_specialization)
1908 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1910 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1913 /* This could be something like:
1915 template <class T> void f(T);
1916 class S { friend void f<>(int); } */
1920 /* This case handles bogus declarations like template <>
1921 template <class T> void f<int>(); */
1923 error ("template-id %qD in declaration of primary template",
1930 case tsk_invalid_member_spec:
1931 /* The error has already been reported in
1932 check_specialization_scope. */
1933 return error_mark_node;
1935 case tsk_invalid_expl_inst:
1936 error ("template parameter list used in explicit instantiation");
1942 error ("definition provided for explicit instantiation");
1944 explicit_instantiation = 1;
1947 case tsk_excessive_parms:
1948 case tsk_insufficient_parms:
1949 if (tsk == tsk_excessive_parms)
1950 error ("too many template parameter lists in declaration of %qD",
1952 else if (template_header_count)
1953 error("too few template parameter lists in declaration of %qD", decl);
1955 error("explicit specialization of %qD must be introduced by "
1956 "%<template <>%>", decl);
1960 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1962 member_specialization = 1;
1968 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1970 /* This case handles bogus declarations like template <>
1971 template <class T> void f<int>(); */
1973 if (uses_template_parms (declarator))
1974 error ("function template partial specialization %qD "
1975 "is not allowed", declarator);
1977 error ("template-id %qD in declaration of primary template",
1982 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
1983 /* This is a specialization of a member template, without
1984 specialization the containing class. Something like:
1986 template <class T> struct S {
1987 template <class U> void f (U);
1989 template <> template <class U> void S<int>::f(U) {}
1991 That's a specialization -- but of the entire template. */
1999 if (specialization || member_specialization)
2001 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2002 for (; t; t = TREE_CHAIN (t))
2003 if (TREE_PURPOSE (t))
2005 permerror (input_location,
2006 "default argument specified in explicit specialization");
2011 if (specialization || member_specialization || explicit_instantiation)
2013 tree tmpl = NULL_TREE;
2014 tree targs = NULL_TREE;
2016 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2017 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2021 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2026 /* If there is no class context, the explicit instantiation
2027 must be at namespace scope. */
2028 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2030 /* Find the namespace binding, using the declaration
2032 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2034 if (fns == error_mark_node || !is_overloaded_fn (fns))
2036 error ("%qD is not a template function", dname);
2037 fns = error_mark_node;
2041 tree fn = OVL_CURRENT (fns);
2042 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2043 CP_DECL_CONTEXT (fn)))
2044 error ("%qD is not declared in %qD",
2045 decl, current_namespace);
2049 declarator = lookup_template_function (fns, NULL_TREE);
2052 if (declarator == error_mark_node)
2053 return error_mark_node;
2055 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2057 if (!explicit_instantiation)
2058 /* A specialization in class scope. This is invalid,
2059 but the error will already have been flagged by
2060 check_specialization_scope. */
2061 return error_mark_node;
2064 /* It's not valid to write an explicit instantiation in
2067 class C { template void f(); }
2069 This case is caught by the parser. However, on
2072 template class C { void f(); };
2074 (which is invalid) we can get here. The error will be
2081 else if (ctype != NULL_TREE
2082 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2085 /* Find the list of functions in ctype that have the same
2086 name as the declared function. */
2087 tree name = TREE_OPERAND (declarator, 0);
2088 tree fns = NULL_TREE;
2091 if (constructor_name_p (name, ctype))
2093 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2095 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2096 : !CLASSTYPE_DESTRUCTORS (ctype))
2098 /* From [temp.expl.spec]:
2100 If such an explicit specialization for the member
2101 of a class template names an implicitly-declared
2102 special member function (clause _special_), the
2103 program is ill-formed.
2105 Similar language is found in [temp.explicit]. */
2106 error ("specialization of implicitly-declared special member function");
2107 return error_mark_node;
2110 name = is_constructor ? ctor_identifier : dtor_identifier;
2113 if (!DECL_CONV_FN_P (decl))
2115 idx = lookup_fnfields_1 (ctype, name);
2117 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2121 VEC(tree,gc) *methods;
2124 /* For a type-conversion operator, we cannot do a
2125 name-based lookup. We might be looking for `operator
2126 int' which will be a specialization of `operator T'.
2127 So, we find *all* the conversion operators, and then
2128 select from them. */
2131 methods = CLASSTYPE_METHOD_VEC (ctype);
2133 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2134 VEC_iterate (tree, methods, idx, ovl);
2137 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2138 /* There are no more conversion functions. */
2141 /* Glue all these conversion functions together
2142 with those we already have. */
2143 for (; ovl; ovl = OVL_NEXT (ovl))
2144 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2148 if (fns == NULL_TREE)
2150 error ("no member function %qD declared in %qT", name, ctype);
2151 return error_mark_node;
2154 TREE_OPERAND (declarator, 0) = fns;
2157 /* Figure out what exactly is being specialized at this point.
2158 Note that for an explicit instantiation, even one for a
2159 member function, we cannot tell apriori whether the
2160 instantiation is for a member template, or just a member
2161 function of a template class. Even if a member template is
2162 being instantiated, the member template arguments may be
2163 elided if they can be deduced from the rest of the
2165 tmpl = determine_specialization (declarator, decl,
2167 member_specialization,
2171 if (!tmpl || tmpl == error_mark_node)
2172 /* We couldn't figure out what this declaration was
2174 return error_mark_node;
2177 tree gen_tmpl = most_general_template (tmpl);
2179 if (explicit_instantiation)
2181 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2182 is done by do_decl_instantiation later. */
2184 int arg_depth = TMPL_ARGS_DEPTH (targs);
2185 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2187 if (arg_depth > parm_depth)
2189 /* If TMPL is not the most general template (for
2190 example, if TMPL is a friend template that is
2191 injected into namespace scope), then there will
2192 be too many levels of TARGS. Remove some of them
2197 new_targs = make_tree_vec (parm_depth);
2198 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2199 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2200 = TREE_VEC_ELT (targs, i);
2204 return instantiate_template (tmpl, targs, tf_error);
2207 /* If we thought that the DECL was a member function, but it
2208 turns out to be specializing a static member function,
2209 make DECL a static member function as well. */
2210 if (DECL_STATIC_FUNCTION_P (tmpl)
2211 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2212 revert_static_member_fn (decl);
2214 /* If this is a specialization of a member template of a
2215 template class, we want to return the TEMPLATE_DECL, not
2216 the specialization of it. */
2217 if (tsk == tsk_template)
2219 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2220 DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl)) = NULL_TREE;
2223 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2224 DECL_SOURCE_LOCATION (DECL_TEMPLATE_RESULT (tmpl))
2225 = DECL_SOURCE_LOCATION (decl);
2226 /* We want to use the argument list specified in the
2227 definition, not in the original declaration. */
2228 DECL_ARGUMENTS (DECL_TEMPLATE_RESULT (tmpl))
2229 = DECL_ARGUMENTS (decl);
2234 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2235 DECL_TEMPLATE_INFO (decl) = tree_cons (tmpl, targs, NULL_TREE);
2237 /* Inherit default function arguments from the template
2238 DECL is specializing. */
2239 copy_default_args_to_explicit_spec (decl);
2241 /* This specialization has the same protection as the
2242 template it specializes. */
2243 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2244 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2246 /* 7.1.1-1 [dcl.stc]
2248 A storage-class-specifier shall not be specified in an
2249 explicit specialization...
2251 The parser rejects these, so unless action is taken here,
2252 explicit function specializations will always appear with
2255 The action recommended by the C++ CWG in response to C++
2256 defect report 605 is to make the storage class and linkage
2257 of the explicit specialization match the templated function:
2259 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2261 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2263 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2264 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2266 /* This specialization has the same linkage and visibility as
2267 the function template it specializes. */
2268 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2269 if (! TREE_PUBLIC (decl))
2271 DECL_INTERFACE_KNOWN (decl) = 1;
2272 DECL_NOT_REALLY_EXTERN (decl) = 1;
2274 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2275 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2277 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2278 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2282 /* If DECL is a friend declaration, declared using an
2283 unqualified name, the namespace associated with DECL may
2284 have been set incorrectly. For example, in:
2286 template <typename T> void f(T);
2288 struct S { friend void f<int>(int); }
2291 we will have set the DECL_CONTEXT for the friend
2292 declaration to N, rather than to the global namespace. */
2293 if (DECL_NAMESPACE_SCOPE_P (decl))
2294 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2296 if (is_friend && !have_def)
2297 /* This is not really a declaration of a specialization.
2298 It's just the name of an instantiation. But, it's not
2299 a request for an instantiation, either. */
2300 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2301 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2302 /* This is indeed a specialization. In case of constructors
2303 and destructors, we need in-charge and not-in-charge
2304 versions in V3 ABI. */
2305 clone_function_decl (decl, /*update_method_vec_p=*/0);
2307 /* Register this specialization so that we can find it
2309 decl = register_specialization (decl, gen_tmpl, targs, is_friend);
2316 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2317 parameters. These are represented in the same format used for
2318 DECL_TEMPLATE_PARMS. */
2321 comp_template_parms (const_tree parms1, const_tree parms2)
2326 if (parms1 == parms2)
2329 for (p1 = parms1, p2 = parms2;
2330 p1 != NULL_TREE && p2 != NULL_TREE;
2331 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2333 tree t1 = TREE_VALUE (p1);
2334 tree t2 = TREE_VALUE (p2);
2337 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2338 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2340 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2343 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2345 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2346 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2348 /* If either of the template parameters are invalid, assume
2349 they match for the sake of error recovery. */
2350 if (parm1 == error_mark_node || parm2 == error_mark_node)
2353 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2356 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2357 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2358 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2360 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2365 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2366 /* One set of parameters has more parameters lists than the
2373 /* Determine whether PARM is a parameter pack. */
2375 template_parameter_pack_p (const_tree parm)
2377 /* Determine if we have a non-type template parameter pack. */
2378 if (TREE_CODE (parm) == PARM_DECL)
2379 return (DECL_TEMPLATE_PARM_P (parm)
2380 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2382 /* If this is a list of template parameters, we could get a
2383 TYPE_DECL or a TEMPLATE_DECL. */
2384 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2385 parm = TREE_TYPE (parm);
2387 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2388 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2389 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2392 /* Determine whether ARGS describes a variadic template args list,
2393 i.e., one that is terminated by a template argument pack. */
2395 template_args_variadic_p (tree args)
2400 if (args == NULL_TREE)
2403 args = INNERMOST_TEMPLATE_ARGS (args);
2404 nargs = TREE_VEC_LENGTH (args);
2409 last_parm = TREE_VEC_ELT (args, nargs - 1);
2411 return ARGUMENT_PACK_P (last_parm);
2414 /* Generate a new name for the parameter pack name NAME (an
2415 IDENTIFIER_NODE) that incorporates its */
2417 make_ith_pack_parameter_name (tree name, int i)
2419 /* Munge the name to include the parameter index. */
2423 sprintf(numbuf, "%i", i);
2424 newname = (char*)alloca (IDENTIFIER_LENGTH (name) + strlen(numbuf) + 2);
2425 sprintf(newname, "%s#%i", IDENTIFIER_POINTER (name), i);
2426 return get_identifier (newname);
2429 /* Structure used to track the progress of find_parameter_packs_r. */
2430 struct find_parameter_pack_data
2432 /* TREE_LIST that will contain all of the parameter packs found by
2434 tree* parameter_packs;
2436 /* Set of AST nodes that have been visited by the traversal. */
2437 struct pointer_set_t *visited;
2440 /* Identifies all of the argument packs that occur in a template
2441 argument and appends them to the TREE_LIST inside DATA, which is a
2442 find_parameter_pack_data structure. This is a subroutine of
2443 make_pack_expansion and uses_parameter_packs. */
2445 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2448 struct find_parameter_pack_data* ppd =
2449 (struct find_parameter_pack_data*)data;
2450 bool parameter_pack_p = false;
2452 /* Identify whether this is a parameter pack or not. */
2453 switch (TREE_CODE (t))
2455 case TEMPLATE_PARM_INDEX:
2456 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2457 parameter_pack_p = true;
2460 case TEMPLATE_TYPE_PARM:
2461 case TEMPLATE_TEMPLATE_PARM:
2462 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2463 parameter_pack_p = true;
2467 if (FUNCTION_PARAMETER_PACK_P (t))
2469 /* We don't want to walk into the type of a PARM_DECL,
2470 because we don't want to see the type parameter pack. */
2472 parameter_pack_p = true;
2477 /* Not a parameter pack. */
2481 if (parameter_pack_p)
2483 /* Add this parameter pack to the list. */
2484 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2488 cp_walk_tree (&TYPE_CONTEXT (t),
2489 &find_parameter_packs_r, ppd, ppd->visited);
2491 /* This switch statement will return immediately if we don't find a
2493 switch (TREE_CODE (t))
2495 case TEMPLATE_PARM_INDEX:
2498 case BOUND_TEMPLATE_TEMPLATE_PARM:
2499 /* Check the template itself. */
2500 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2501 &find_parameter_packs_r, ppd, ppd->visited);
2502 /* Check the template arguments. */
2503 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2508 case TEMPLATE_TYPE_PARM:
2509 case TEMPLATE_TEMPLATE_PARM:
2516 if (TYPE_PTRMEMFUNC_P (t))
2522 if (TYPE_TEMPLATE_INFO (t))
2523 cp_walk_tree (&TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
2524 &find_parameter_packs_r, ppd, ppd->visited);
2530 cp_walk_tree (&TREE_TYPE (t),
2531 &find_parameter_packs_r, ppd, ppd->visited);
2535 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
2540 case TYPE_PACK_EXPANSION:
2541 case EXPR_PACK_EXPANSION:
2546 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
2551 case IDENTIFIER_NODE:
2552 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
2564 /* Determines if the expression or type T uses any parameter packs. */
2566 uses_parameter_packs (tree t)
2568 tree parameter_packs = NULL_TREE;
2569 struct find_parameter_pack_data ppd;
2570 ppd.parameter_packs = ¶meter_packs;
2571 ppd.visited = pointer_set_create ();
2572 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2573 pointer_set_destroy (ppd.visited);
2574 return parameter_packs != NULL_TREE;
2577 /* Turn ARG, which may be an expression, type, or a TREE_LIST
2578 representation a base-class initializer into a parameter pack
2579 expansion. If all goes well, the resulting node will be an
2580 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
2583 make_pack_expansion (tree arg)
2586 tree parameter_packs = NULL_TREE;
2587 bool for_types = false;
2588 struct find_parameter_pack_data ppd;
2590 if (!arg || arg == error_mark_node)
2593 if (TREE_CODE (arg) == TREE_LIST)
2595 /* The only time we will see a TREE_LIST here is for a base
2596 class initializer. In this case, the TREE_PURPOSE will be a
2597 _TYPE node (representing the base class expansion we're
2598 initializing) and the TREE_VALUE will be a TREE_LIST
2599 containing the initialization arguments.
2601 The resulting expansion looks somewhat different from most
2602 expansions. Rather than returning just one _EXPANSION, we
2603 return a TREE_LIST whose TREE_PURPOSE is a
2604 TYPE_PACK_EXPANSION containing the bases that will be
2605 initialized. The TREE_VALUE will be identical to the
2606 original TREE_VALUE, which is a list of arguments that will
2607 be passed to each base. We do not introduce any new pack
2608 expansion nodes into the TREE_VALUE (although it is possible
2609 that some already exist), because the TREE_PURPOSE and
2610 TREE_VALUE all need to be expanded together with the same
2611 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
2612 resulting TREE_PURPOSE will mention the parameter packs in
2613 both the bases and the arguments to the bases. */
2616 tree parameter_packs = NULL_TREE;
2618 /* Determine which parameter packs will be used by the base
2620 ppd.visited = pointer_set_create ();
2621 ppd.parameter_packs = ¶meter_packs;
2622 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
2625 if (parameter_packs == NULL_TREE)
2627 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
2628 pointer_set_destroy (ppd.visited);
2629 return error_mark_node;
2632 if (TREE_VALUE (arg) != void_type_node)
2634 /* Collect the sets of parameter packs used in each of the
2635 initialization arguments. */
2636 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
2638 /* Determine which parameter packs will be expanded in this
2640 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
2645 pointer_set_destroy (ppd.visited);
2647 /* Create the pack expansion type for the base type. */
2648 purpose = make_node (TYPE_PACK_EXPANSION);
2649 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
2650 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
2652 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
2653 they will rarely be compared to anything. */
2654 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
2656 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
2659 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
2662 /* Build the PACK_EXPANSION_* node. */
2663 result = make_node (for_types ? TYPE_PACK_EXPANSION : EXPR_PACK_EXPANSION);
2664 SET_PACK_EXPANSION_PATTERN (result, arg);
2665 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
2667 /* Propagate type and const-expression information. */
2668 TREE_TYPE (result) = TREE_TYPE (arg);
2669 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
2672 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
2673 they will rarely be compared to anything. */
2674 SET_TYPE_STRUCTURAL_EQUALITY (result);
2676 /* Determine which parameter packs will be expanded. */
2677 ppd.parameter_packs = ¶meter_packs;
2678 ppd.visited = pointer_set_create ();
2679 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
2680 pointer_set_destroy (ppd.visited);
2682 /* Make sure we found some parameter packs. */
2683 if (parameter_packs == NULL_TREE)
2686 error ("expansion pattern %<%T%> contains no argument packs", arg);
2688 error ("expansion pattern %<%E%> contains no argument packs", arg);
2689 return error_mark_node;
2691 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
2696 /* Checks T for any "bare" parameter packs, which have not yet been
2697 expanded, and issues an error if any are found. This operation can
2698 only be done on full expressions or types (e.g., an expression
2699 statement, "if" condition, etc.), because we could have expressions like:
2701 foo(f(g(h(args)))...)
2703 where "args" is a parameter pack. check_for_bare_parameter_packs
2704 should not be called for the subexpressions args, h(args),
2705 g(h(args)), or f(g(h(args))), because we would produce erroneous
2708 Returns TRUE and emits an error if there were bare parameter packs,
2709 returns FALSE otherwise. */
2711 check_for_bare_parameter_packs (tree t)
2713 tree parameter_packs = NULL_TREE;
2714 struct find_parameter_pack_data ppd;
2716 if (!processing_template_decl || !t || t == error_mark_node)
2719 if (TREE_CODE (t) == TYPE_DECL)
2722 ppd.parameter_packs = ¶meter_packs;
2723 ppd.visited = pointer_set_create ();
2724 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2725 pointer_set_destroy (ppd.visited);
2727 if (parameter_packs)
2729 error ("parameter packs not expanded with %<...%>:");
2730 while (parameter_packs)
2732 tree pack = TREE_VALUE (parameter_packs);
2733 tree name = NULL_TREE;
2735 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
2736 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
2737 name = TYPE_NAME (pack);
2738 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
2739 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
2741 name = DECL_NAME (pack);
2744 inform (input_location, " %qD", name);
2746 inform (input_location, " <anonymous>");
2748 parameter_packs = TREE_CHAIN (parameter_packs);
2757 /* Expand any parameter packs that occur in the template arguments in
2760 expand_template_argument_pack (tree args)
2762 tree result_args = NULL_TREE;
2763 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
2764 int num_result_args = -1;
2766 /* First, determine if we need to expand anything, and the number of
2767 slots we'll need. */
2768 for (in_arg = 0; in_arg < nargs; ++in_arg)
2770 tree arg = TREE_VEC_ELT (args, in_arg);
2771 if (ARGUMENT_PACK_P (arg))
2773 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
2774 if (num_result_args < 0)
2775 num_result_args = in_arg + num_packed;
2777 num_result_args += num_packed;
2781 if (num_result_args >= 0)
2786 /* If no expansion is necessary, we're done. */
2787 if (num_result_args < 0)
2790 /* Expand arguments. */
2791 result_args = make_tree_vec (num_result_args);
2792 for (in_arg = 0; in_arg < nargs; ++in_arg)
2794 tree arg = TREE_VEC_ELT (args, in_arg);
2795 if (ARGUMENT_PACK_P (arg))
2797 tree packed = ARGUMENT_PACK_ARGS (arg);
2798 int i, num_packed = TREE_VEC_LENGTH (packed);
2799 for (i = 0; i < num_packed; ++i, ++out_arg)
2800 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
2804 TREE_VEC_ELT (result_args, out_arg) = arg;
2812 /* Checks if DECL shadows a template parameter.
2814 [temp.local]: A template-parameter shall not be redeclared within its
2815 scope (including nested scopes).
2817 Emits an error and returns TRUE if the DECL shadows a parameter,
2818 returns FALSE otherwise. */
2821 check_template_shadow (tree decl)
2825 /* If we're not in a template, we can't possibly shadow a template
2827 if (!current_template_parms)
2830 /* Figure out what we're shadowing. */
2831 if (TREE_CODE (decl) == OVERLOAD)
2832 decl = OVL_CURRENT (decl);
2833 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
2835 /* If there's no previous binding for this name, we're not shadowing
2836 anything, let alone a template parameter. */
2840 /* If we're not shadowing a template parameter, we're done. Note
2841 that OLDDECL might be an OVERLOAD (or perhaps even an
2842 ERROR_MARK), so we can't just blithely assume it to be a _DECL
2844 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
2847 /* We check for decl != olddecl to avoid bogus errors for using a
2848 name inside a class. We check TPFI to avoid duplicate errors for
2849 inline member templates. */
2851 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
2854 error ("declaration of %q+#D", decl);
2855 error (" shadows template parm %q+#D", olddecl);
2859 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
2860 ORIG_LEVEL, DECL, and TYPE. */
2863 build_template_parm_index (int index,
2869 tree t = make_node (TEMPLATE_PARM_INDEX);
2870 TEMPLATE_PARM_IDX (t) = index;
2871 TEMPLATE_PARM_LEVEL (t) = level;
2872 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
2873 TEMPLATE_PARM_DECL (t) = decl;
2874 TREE_TYPE (t) = type;
2875 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
2876 TREE_READONLY (t) = TREE_READONLY (decl);
2881 /* Find the canonical type parameter for the given template type
2882 parameter. Returns the canonical type parameter, which may be TYPE
2883 if no such parameter existed. */
2885 canonical_type_parameter (tree type)
2888 int idx = TEMPLATE_TYPE_IDX (type);
2889 if (!canonical_template_parms)
2890 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
2892 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
2893 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
2895 list = VEC_index (tree, canonical_template_parms, idx);
2896 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
2897 list = TREE_CHAIN (list);
2900 return TREE_VALUE (list);
2903 VEC_replace(tree, canonical_template_parms, idx,
2904 tree_cons (NULL_TREE, type,
2905 VEC_index (tree, canonical_template_parms, idx)));
2910 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
2911 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
2912 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
2913 new one is created. */
2916 reduce_template_parm_level (tree index, tree type, int levels, tree args,
2917 tsubst_flags_t complain)
2919 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
2920 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
2921 != TEMPLATE_PARM_LEVEL (index) - levels))
2923 tree orig_decl = TEMPLATE_PARM_DECL (index);
2926 decl = build_decl (TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
2927 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
2928 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
2929 DECL_ARTIFICIAL (decl) = 1;
2930 SET_DECL_TEMPLATE_PARM_P (decl);
2932 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
2933 TEMPLATE_PARM_LEVEL (index) - levels,
2934 TEMPLATE_PARM_ORIG_LEVEL (index),
2936 TEMPLATE_PARM_DESCENDANTS (index) = t;
2937 TEMPLATE_PARM_PARAMETER_PACK (t)
2938 = TEMPLATE_PARM_PARAMETER_PACK (index);
2940 /* Template template parameters need this. */
2941 if (TREE_CODE (decl) == TEMPLATE_DECL)
2942 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
2943 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
2947 return TEMPLATE_PARM_DESCENDANTS (index);
2950 /* Process information from new template parameter PARM and append it to the
2951 LIST being built. This new parameter is a non-type parameter iff
2952 IS_NON_TYPE is true. This new parameter is a parameter
2953 pack iff IS_PARAMETER_PACK is true. */
2956 process_template_parm (tree list, tree parm, bool is_non_type,
2957 bool is_parameter_pack)
2964 gcc_assert (TREE_CODE (parm) == TREE_LIST);
2965 defval = TREE_PURPOSE (parm);
2969 tree p = tree_last (list);
2971 if (p && TREE_VALUE (p) != error_mark_node)
2974 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
2975 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
2977 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
2987 parm = TREE_VALUE (parm);
2989 SET_DECL_TEMPLATE_PARM_P (parm);
2991 if (TREE_TYPE (parm) == error_mark_node)
2993 err_parm_list = build_tree_list (defval, parm);
2994 TREE_VALUE (err_parm_list) = error_mark_node;
2995 return chainon (list, err_parm_list);
3001 The top-level cv-qualifiers on the template-parameter are
3002 ignored when determining its type. */
3003 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3004 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3006 err_parm_list = build_tree_list (defval, parm);
3007 TREE_VALUE (err_parm_list) = error_mark_node;
3008 return chainon (list, err_parm_list);
3011 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3013 /* This template parameter is not a parameter pack, but it
3014 should be. Complain about "bare" parameter packs. */
3015 check_for_bare_parameter_packs (TREE_TYPE (parm));
3017 /* Recover by calling this a parameter pack. */
3018 is_parameter_pack = true;
3022 /* A template parameter is not modifiable. */
3023 TREE_CONSTANT (parm) = 1;
3024 TREE_READONLY (parm) = 1;
3025 decl = build_decl (CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3026 TREE_CONSTANT (decl) = 1;
3027 TREE_READONLY (decl) = 1;
3028 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3029 = build_template_parm_index (idx, processing_template_decl,
3030 processing_template_decl,
3031 decl, TREE_TYPE (parm));
3033 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3034 = is_parameter_pack;
3039 parm = TREE_VALUE (TREE_VALUE (parm));
3041 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3043 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3044 /* This is for distinguishing between real templates and template
3045 template parameters */
3046 TREE_TYPE (parm) = t;
3047 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3052 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3053 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3054 decl = build_decl (TYPE_DECL, parm, t);
3057 TYPE_NAME (t) = decl;
3058 TYPE_STUB_DECL (t) = decl;
3060 TEMPLATE_TYPE_PARM_INDEX (t)
3061 = build_template_parm_index (idx, processing_template_decl,
3062 processing_template_decl,
3063 decl, TREE_TYPE (parm));
3064 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3065 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3067 DECL_ARTIFICIAL (decl) = 1;
3068 SET_DECL_TEMPLATE_PARM_P (decl);
3070 parm = build_tree_list (defval, parm);
3071 return chainon (list, parm);
3074 /* The end of a template parameter list has been reached. Process the
3075 tree list into a parameter vector, converting each parameter into a more
3076 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3080 end_template_parm_list (tree parms)
3084 tree saved_parmlist = make_tree_vec (list_length (parms));
3086 current_template_parms
3087 = tree_cons (size_int (processing_template_decl),
3088 saved_parmlist, current_template_parms);
3090 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3092 next = TREE_CHAIN (parm);
3093 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3094 TREE_CHAIN (parm) = NULL_TREE;
3097 --processing_template_parmlist;
3099 return saved_parmlist;
3102 /* end_template_decl is called after a template declaration is seen. */
3105 end_template_decl (void)
3107 reset_specialization ();
3109 if (! processing_template_decl)
3112 /* This matches the pushlevel in begin_template_parm_list. */
3115 --processing_template_decl;
3116 current_template_parms = TREE_CHAIN (current_template_parms);
3119 /* Within the declaration of a template, return all levels of template
3120 parameters that apply. The template parameters are represented as
3121 a TREE_VEC, in the form documented in cp-tree.h for template
3125 current_template_args (void)
3128 tree args = NULL_TREE;
3129 int length = TMPL_PARMS_DEPTH (current_template_parms);
3132 /* If there is only one level of template parameters, we do not
3133 create a TREE_VEC of TREE_VECs. Instead, we return a single
3134 TREE_VEC containing the arguments. */
3136 args = make_tree_vec (length);
3138 for (header = current_template_parms; header; header = TREE_CHAIN (header))
3140 tree a = copy_node (TREE_VALUE (header));
3143 TREE_TYPE (a) = NULL_TREE;
3144 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3146 tree t = TREE_VEC_ELT (a, i);
3148 /* T will be a list if we are called from within a
3149 begin/end_template_parm_list pair, but a vector directly
3150 if within a begin/end_member_template_processing pair. */
3151 if (TREE_CODE (t) == TREE_LIST)
3155 if (!error_operand_p (t))
3157 if (TREE_CODE (t) == TYPE_DECL
3158 || TREE_CODE (t) == TEMPLATE_DECL)
3162 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3164 /* Turn this argument into a TYPE_ARGUMENT_PACK
3165 with a single element, which expands T. */
3166 tree vec = make_tree_vec (1);
3167 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3169 t = make_node (TYPE_ARGUMENT_PACK);
3170 SET_ARGUMENT_PACK_ARGS (t, vec);
3175 t = DECL_INITIAL (t);
3177 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3179 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3180 with a single element, which expands T. */
3181 tree vec = make_tree_vec (1);
3182 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3183 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3185 t = make_node (NONTYPE_ARGUMENT_PACK);
3186 SET_ARGUMENT_PACK_ARGS (t, vec);
3187 TREE_TYPE (t) = type;
3190 TREE_VEC_ELT (a, i) = t;
3196 TREE_VEC_ELT (args, --l) = a;
3204 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3205 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3206 a member template. Used by push_template_decl below. */
3209 build_template_decl (tree decl, tree parms, bool member_template_p)
3211 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3212 DECL_TEMPLATE_PARMS (tmpl) = parms;
3213 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3214 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3215 if (DECL_LANG_SPECIFIC (decl))
3217 DECL_STATIC_FUNCTION_P (tmpl) = DECL_STATIC_FUNCTION_P (decl);
3218 DECL_CONSTRUCTOR_P (tmpl) = DECL_CONSTRUCTOR_P (decl);
3219 DECL_DESTRUCTOR_P (tmpl) = DECL_DESTRUCTOR_P (decl);
3220 DECL_NONCONVERTING_P (tmpl) = DECL_NONCONVERTING_P (decl);
3221 DECL_ASSIGNMENT_OPERATOR_P (tmpl) = DECL_ASSIGNMENT_OPERATOR_P (decl);
3222 if (DECL_OVERLOADED_OPERATOR_P (decl))
3223 SET_OVERLOADED_OPERATOR_CODE (tmpl,
3224 DECL_OVERLOADED_OPERATOR_P (decl));
3230 struct template_parm_data
3232 /* The level of the template parameters we are currently
3236 /* The index of the specialization argument we are currently
3240 /* An array whose size is the number of template parameters. The
3241 elements are nonzero if the parameter has been used in any one
3242 of the arguments processed so far. */
3245 /* An array whose size is the number of template arguments. The
3246 elements are nonzero if the argument makes use of template
3247 parameters of this level. */
3248 int* arg_uses_template_parms;
3251 /* Subroutine of push_template_decl used to see if each template
3252 parameter in a partial specialization is used in the explicit
3253 argument list. If T is of the LEVEL given in DATA (which is
3254 treated as a template_parm_data*), then DATA->PARMS is marked
3258 mark_template_parm (tree t, void* data)
3262 struct template_parm_data* tpd = (struct template_parm_data*) data;
3264 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3266 level = TEMPLATE_PARM_LEVEL (t);
3267 idx = TEMPLATE_PARM_IDX (t);
3271 level = TEMPLATE_TYPE_LEVEL (t);
3272 idx = TEMPLATE_TYPE_IDX (t);
3275 if (level == tpd->level)
3277 tpd->parms[idx] = 1;
3278 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
3281 /* Return zero so that for_each_template_parm will continue the
3282 traversal of the tree; we want to mark *every* template parm. */
3286 /* Process the partial specialization DECL. */
3289 process_partial_specialization (tree decl)
3291 tree type = TREE_TYPE (decl);
3292 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
3293 tree specargs = CLASSTYPE_TI_ARGS (type);
3294 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
3295 tree inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3296 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
3297 int nargs = TREE_VEC_LENGTH (inner_args);
3298 int ntparms = TREE_VEC_LENGTH (inner_parms);
3300 int did_error_intro = 0;
3301 struct template_parm_data tpd;
3302 struct template_parm_data tpd2;
3304 /* We check that each of the template parameters given in the
3305 partial specialization is used in the argument list to the
3306 specialization. For example:
3308 template <class T> struct S;
3309 template <class T> struct S<T*>;
3311 The second declaration is OK because `T*' uses the template
3312 parameter T, whereas
3314 template <class T> struct S<int>;
3316 is no good. Even trickier is:
3327 The S2<T> declaration is actually invalid; it is a
3328 full-specialization. Of course,
3331 struct S2<T (*)(U)>;
3333 or some such would have been OK. */
3334 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
3335 tpd.parms = (int *) alloca (sizeof (int) * ntparms);
3336 memset (tpd.parms, 0, sizeof (int) * ntparms);
3338 tpd.arg_uses_template_parms = (int *) alloca (sizeof (int) * nargs);
3339 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
3340 for (i = 0; i < nargs; ++i)
3342 tpd.current_arg = i;
3343 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
3344 &mark_template_parm,
3347 /*include_nondeduced_p=*/false);
3349 for (i = 0; i < ntparms; ++i)
3350 if (tpd.parms[i] == 0)
3352 /* One of the template parms was not used in the
3354 if (!did_error_intro)
3356 error ("template parameters not used in partial specialization:");
3357 did_error_intro = 1;
3360 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
3363 /* [temp.class.spec]
3365 The argument list of the specialization shall not be identical to
3366 the implicit argument list of the primary template. */
3367 if (comp_template_args
3369 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
3371 error ("partial specialization %qT does not specialize any template arguments", type);
3373 /* [temp.class.spec]
3375 A partially specialized non-type argument expression shall not
3376 involve template parameters of the partial specialization except
3377 when the argument expression is a simple identifier.
3379 The type of a template parameter corresponding to a specialized
3380 non-type argument shall not be dependent on a parameter of the
3383 Also, we verify that pack expansions only occur at the
3384 end of the argument list. */
3385 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
3387 for (i = 0; i < nargs; ++i)
3389 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
3390 tree arg = TREE_VEC_ELT (inner_args, i);
3391 tree packed_args = NULL_TREE;
3394 if (ARGUMENT_PACK_P (arg))
3396 /* Extract the arguments from the argument pack. We'll be
3397 iterating over these in the following loop. */
3398 packed_args = ARGUMENT_PACK_ARGS (arg);
3399 len = TREE_VEC_LENGTH (packed_args);
3402 for (j = 0; j < len; j++)
3405 /* Get the Jth argument in the parameter pack. */
3406 arg = TREE_VEC_ELT (packed_args, j);
3408 if (PACK_EXPANSION_P (arg))
3410 /* Pack expansions must come at the end of the
3412 if ((packed_args && j < len - 1)
3413 || (!packed_args && i < nargs - 1))
3415 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3416 error ("parameter pack argument %qE must be at the end of the template argument list", arg);
3418 error ("parameter pack argument %qT must be at the end of the template argument list", arg);
3421 TREE_VEC_ELT (packed_args, j) = error_mark_node;
3425 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3426 /* We only care about the pattern. */
3427 arg = PACK_EXPANSION_PATTERN (arg);
3429 if (/* These first two lines are the `non-type' bit. */
3431 && TREE_CODE (arg) != TEMPLATE_DECL
3432 /* This next line is the `argument expression is not just a
3433 simple identifier' condition and also the `specialized
3434 non-type argument' bit. */
3435 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
3437 if ((!packed_args && tpd.arg_uses_template_parms[i])
3438 || (packed_args && uses_template_parms (arg)))
3439 error ("template argument %qE involves template parameter(s)",
3443 /* Look at the corresponding template parameter,
3444 marking which template parameters its type depends
3446 tree type = TREE_TYPE (parm);
3450 /* We haven't yet initialized TPD2. Do so now. */
3451 tpd2.arg_uses_template_parms
3452 = (int *) alloca (sizeof (int) * nargs);
3453 /* The number of parameters here is the number in the
3454 main template, which, as checked in the assertion
3456 tpd2.parms = (int *) alloca (sizeof (int) * nargs);
3458 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
3461 /* Mark the template parameters. But this time, we're
3462 looking for the template parameters of the main
3463 template, not in the specialization. */
3464 tpd2.current_arg = i;
3465 tpd2.arg_uses_template_parms[i] = 0;
3466 memset (tpd2.parms, 0, sizeof (int) * nargs);
3467 for_each_template_parm (type,
3468 &mark_template_parm,
3471 /*include_nondeduced_p=*/false);
3473 if (tpd2.arg_uses_template_parms [i])
3475 /* The type depended on some template parameters.
3476 If they are fully specialized in the
3477 specialization, that's OK. */
3479 for (j = 0; j < nargs; ++j)
3480 if (tpd2.parms[j] != 0
3481 && tpd.arg_uses_template_parms [j])
3483 error ("type %qT of template argument %qE depends "
3484 "on template parameter(s)",
3495 if (retrieve_specialization (maintmpl, specargs,
3496 /*class_specializations_p=*/true))
3497 /* We've already got this specialization. */
3500 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
3501 = tree_cons (specargs, inner_parms,
3502 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
3503 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
3507 /* Check that a template declaration's use of default arguments and
3508 parameter packs is not invalid. Here, PARMS are the template
3509 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
3510 a primary template. IS_PARTIAL is nonzero if DECL is a partial
3514 IS_FRIEND_DECL is nonzero if DECL is a friend function template
3515 declaration (but not a definition); 1 indicates a declaration, 2
3516 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
3517 emitted for extraneous default arguments.
3519 Returns TRUE if there were no errors found, FALSE otherwise. */
3522 check_default_tmpl_args (tree decl, tree parms, int is_primary,
3523 int is_partial, int is_friend_decl)
3526 int last_level_to_check;
3528 bool no_errors = true;
3532 A default template-argument shall not be specified in a
3533 function template declaration or a function template definition, nor
3534 in the template-parameter-list of the definition of a member of a
3537 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
3538 /* You can't have a function template declaration in a local
3539 scope, nor you can you define a member of a class template in a
3543 if (current_class_type
3544 && !TYPE_BEING_DEFINED (current_class_type)
3545 && DECL_LANG_SPECIFIC (decl)
3546 /* If this is either a friend defined in the scope of the class
3547 or a member function. */
3548 && (DECL_FUNCTION_MEMBER_P (decl)
3549 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
3550 : DECL_FRIEND_CONTEXT (decl)
3551 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
3553 /* And, if it was a member function, it really was defined in
3554 the scope of the class. */
3555 && (!DECL_FUNCTION_MEMBER_P (decl)
3556 || DECL_INITIALIZED_IN_CLASS_P (decl)))
3557 /* We already checked these parameters when the template was
3558 declared, so there's no need to do it again now. This function
3559 was defined in class scope, but we're processing it's body now
3560 that the class is complete. */
3563 /* Core issue 226 (C++0x only): the following only applies to class
3565 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
3569 If a template-parameter has a default template-argument, all
3570 subsequent template-parameters shall have a default
3571 template-argument supplied. */
3572 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
3574 tree inner_parms = TREE_VALUE (parm_level);
3575 int ntparms = TREE_VEC_LENGTH (inner_parms);
3576 int seen_def_arg_p = 0;
3579 for (i = 0; i < ntparms; ++i)
3581 tree parm = TREE_VEC_ELT (inner_parms, i);
3583 if (parm == error_mark_node)
3586 if (TREE_PURPOSE (parm))
3588 else if (seen_def_arg_p)
3590 error ("no default argument for %qD", TREE_VALUE (parm));
3591 /* For better subsequent error-recovery, we indicate that
3592 there should have been a default argument. */
3593 TREE_PURPOSE (parm) = error_mark_node;
3599 && TREE_CODE (decl) == TYPE_DECL
3601 && template_parameter_pack_p (TREE_VALUE (parm)))
3603 /* A primary class template can only have one
3604 parameter pack, at the end of the template
3607 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
3608 error ("parameter pack %qE must be at the end of the"
3609 " template parameter list", TREE_VALUE (parm));
3611 error ("parameter pack %qT must be at the end of the"
3612 " template parameter list",
3613 TREE_TYPE (TREE_VALUE (parm)));
3615 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
3623 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
3627 /* For an ordinary class template, default template arguments are
3628 allowed at the innermost level, e.g.:
3629 template <class T = int>
3631 but, in a partial specialization, they're not allowed even
3632 there, as we have in [temp.class.spec]:
3634 The template parameter list of a specialization shall not
3635 contain default template argument values.
3637 So, for a partial specialization, or for a function template
3638 (in C++98/C++03), we look at all of them. */
3641 /* But, for a primary class template that is not a partial
3642 specialization we look at all template parameters except the
3644 parms = TREE_CHAIN (parms);
3646 /* Figure out what error message to issue. */
3647 if (is_friend_decl == 2)
3648 msg = "default template arguments may not be used in function template friend re-declaration";
3649 else if (is_friend_decl)
3650 msg = "default template arguments may not be used in function template friend declarations";
3651 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
3652 msg = "default template arguments may not be used in function templates";
3653 else if (is_partial)
3654 msg = "default template arguments may not be used in partial specializations";
3656 msg = "default argument for template parameter for class enclosing %qD";
3658 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
3659 /* If we're inside a class definition, there's no need to
3660 examine the parameters to the class itself. On the one
3661 hand, they will be checked when the class is defined, and,
3662 on the other, default arguments are valid in things like:
3663 template <class T = double>
3664 struct S { template <class U> void f(U); };
3665 Here the default argument for `S' has no bearing on the
3666 declaration of `f'. */
3667 last_level_to_check = template_class_depth (current_class_type) + 1;
3669 /* Check everything. */
3670 last_level_to_check = 0;
3672 for (parm_level = parms;
3673 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
3674 parm_level = TREE_CHAIN (parm_level))
3676 tree inner_parms = TREE_VALUE (parm_level);
3680 ntparms = TREE_VEC_LENGTH (inner_parms);
3681 for (i = 0; i < ntparms; ++i)
3683 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
3686 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
3691 if (is_friend_decl == 2)
3698 /* Clear out the default argument so that we are not
3700 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
3704 /* At this point, if we're still interested in issuing messages,
3705 they must apply to classes surrounding the object declared. */
3707 msg = "default argument for template parameter for class enclosing %qD";
3713 /* Worker for push_template_decl_real, called via
3714 for_each_template_parm. DATA is really an int, indicating the
3715 level of the parameters we are interested in. If T is a template
3716 parameter of that level, return nonzero. */
3719 template_parm_this_level_p (tree t, void* data)
3721 int this_level = *(int *)data;
3724 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3725 level = TEMPLATE_PARM_LEVEL (t);
3727 level = TEMPLATE_TYPE_LEVEL (t);
3728 return level == this_level;
3731 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
3732 parameters given by current_template_args, or reuses a
3733 previously existing one, if appropriate. Returns the DECL, or an
3734 equivalent one, if it is replaced via a call to duplicate_decls.
3736 If IS_FRIEND is true, DECL is a friend declaration. */
3739 push_template_decl_real (tree decl, bool is_friend)
3747 int new_template_p = 0;
3748 /* True if the template is a member template, in the sense of
3750 bool member_template_p = false;
3752 if (decl == error_mark_node)
3755 /* See if this is a partial specialization. */
3756 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
3757 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
3758 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
3760 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
3764 /* For a friend, we want the context of the friend function, not
3765 the type of which it is a friend. */
3766 ctx = DECL_CONTEXT (decl);
3767 else if (CP_DECL_CONTEXT (decl)
3768 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
3769 /* In the case of a virtual function, we want the class in which
3771 ctx = CP_DECL_CONTEXT (decl);
3773 /* Otherwise, if we're currently defining some class, the DECL
3774 is assumed to be a member of the class. */
3775 ctx = current_scope ();
3777 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
3780 if (!DECL_CONTEXT (decl))
3781 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
3783 /* See if this is a primary template. */
3784 if (is_friend && ctx)
3785 /* A friend template that specifies a class context, i.e.
3786 template <typename T> friend void A<T>::f();
3790 primary = template_parm_scope_p ();
3794 if (DECL_CLASS_SCOPE_P (decl))
3795 member_template_p = true;
3796 if (TREE_CODE (decl) == TYPE_DECL
3797 && ANON_AGGRNAME_P (DECL_NAME (decl)))
3799 error ("template class without a name");
3800 return error_mark_node;
3802 else if (TREE_CODE (decl) == FUNCTION_DECL)
3804 if (DECL_DESTRUCTOR_P (decl))
3808 A destructor shall not be a member template. */
3809 error ("destructor %qD declared as member template", decl);
3810 return error_mark_node;
3812 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
3813 && (!TYPE_ARG_TYPES (TREE_TYPE (decl))
3814 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
3815 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
3816 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
3817 == void_list_node)))
3819 /* [basic.stc.dynamic.allocation]
3821 An allocation function can be a function
3822 template. ... Template allocation functions shall
3823 have two or more parameters. */
3824 error ("invalid template declaration of %qD", decl);
3825 return error_mark_node;
3828 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
3829 && CLASS_TYPE_P (TREE_TYPE (decl)))
3833 error ("template declaration of %q#D", decl);
3834 return error_mark_node;
3838 /* Check to see that the rules regarding the use of default
3839 arguments are not being violated. */
3840 check_default_tmpl_args (decl, current_template_parms,
3841 primary, is_partial, /*is_friend_decl=*/0);
3843 /* Ensure that there are no parameter packs in the type of this
3844 declaration that have not been expanded. */
3845 if (TREE_CODE (decl) == FUNCTION_DECL)
3847 /* Check each of the arguments individually to see if there are
3848 any bare parameter packs. */
3849 tree type = TREE_TYPE (decl);
3850 tree arg = DECL_ARGUMENTS (decl);
3851 tree argtype = TYPE_ARG_TYPES (type);
3853 while (arg && argtype)
3855 if (!FUNCTION_PARAMETER_PACK_P (arg)
3856 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
3858 /* This is a PARM_DECL that contains unexpanded parameter
3859 packs. We have already complained about this in the
3860 check_for_bare_parameter_packs call, so just replace
3861 these types with ERROR_MARK_NODE. */
3862 TREE_TYPE (arg) = error_mark_node;
3863 TREE_VALUE (argtype) = error_mark_node;
3866 arg = TREE_CHAIN (arg);
3867 argtype = TREE_CHAIN (argtype);
3870 /* Check for bare parameter packs in the return type and the
3871 exception specifiers. */
3872 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
3873 /* Errors were already issued, set return type to int
3874 as the frontend doesn't expect error_mark_node as
3876 TREE_TYPE (type) = integer_type_node;
3877 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
3878 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
3880 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
3882 TREE_TYPE (decl) = error_mark_node;
3883 return error_mark_node;
3887 return process_partial_specialization (decl);
3889 args = current_template_args ();
3892 || TREE_CODE (ctx) == FUNCTION_DECL
3893 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
3894 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
3896 if (DECL_LANG_SPECIFIC (decl)
3897 && DECL_TEMPLATE_INFO (decl)
3898 && DECL_TI_TEMPLATE (decl))
3899 tmpl = DECL_TI_TEMPLATE (decl);
3900 /* If DECL is a TYPE_DECL for a class-template, then there won't
3901 be DECL_LANG_SPECIFIC. The information equivalent to
3902 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
3903 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
3904 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
3905 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
3907 /* Since a template declaration already existed for this
3908 class-type, we must be redeclaring it here. Make sure
3909 that the redeclaration is valid. */
3910 redeclare_class_template (TREE_TYPE (decl),
3911 current_template_parms);
3912 /* We don't need to create a new TEMPLATE_DECL; just use the
3913 one we already had. */
3914 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
3918 tmpl = build_template_decl (decl, current_template_parms,
3922 if (DECL_LANG_SPECIFIC (decl)
3923 && DECL_TEMPLATE_SPECIALIZATION (decl))
3925 /* A specialization of a member template of a template
3927 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
3928 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
3929 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
3935 tree a, t, current, parms;
3937 tree tinfo = get_template_info (decl);
3941 error ("template definition of non-template %q#D", decl);
3942 return error_mark_node;
3945 tmpl = TI_TEMPLATE (tinfo);
3947 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
3948 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
3949 && DECL_TEMPLATE_SPECIALIZATION (decl)
3950 && DECL_MEMBER_TEMPLATE_P (tmpl))
3954 /* The declaration is a specialization of a member
3955 template, declared outside the class. Therefore, the
3956 innermost template arguments will be NULL, so we
3957 replace them with the arguments determined by the
3958 earlier call to check_explicit_specialization. */
3959 args = DECL_TI_ARGS (decl);
3962 = build_template_decl (decl, current_template_parms,
3964 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
3965 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
3966 DECL_TI_TEMPLATE (decl) = new_tmpl;
3967 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
3968 DECL_TEMPLATE_INFO (new_tmpl)
3969 = tree_cons (tmpl, args, NULL_TREE);
3971 register_specialization (new_tmpl,
3972 most_general_template (tmpl),
3978 /* Make sure the template headers we got make sense. */
3980 parms = DECL_TEMPLATE_PARMS (tmpl);
3981 i = TMPL_PARMS_DEPTH (parms);
3982 if (TMPL_ARGS_DEPTH (args) != i)
3984 error ("expected %d levels of template parms for %q#D, got %d",
3985 i, decl, TMPL_ARGS_DEPTH (args));
3988 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
3990 a = TMPL_ARGS_LEVEL (args, i);
3991 t = INNERMOST_TEMPLATE_PARMS (parms);
3993 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
3995 if (current == decl)
3996 error ("got %d template parameters for %q#D",
3997 TREE_VEC_LENGTH (a), decl);
3999 error ("got %d template parameters for %q#T",
4000 TREE_VEC_LENGTH (a), current);
4001 error (" but %d required", TREE_VEC_LENGTH (t));
4002 return error_mark_node;
4005 if (current == decl)
4008 current = (TYPE_P (current)
4009 ? TYPE_CONTEXT (current)
4010 : DECL_CONTEXT (current));
4013 /* Check that the parms are used in the appropriate qualifying scopes
4014 in the declarator. */
4015 if (!comp_template_args
4017 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4020 template arguments to %qD do not match original template %qD",
4021 decl, DECL_TEMPLATE_RESULT (tmpl));
4022 if (!uses_template_parms (TI_ARGS (tinfo)))
4023 inform (input_location, "use template<> for an explicit specialization");
4024 /* Avoid crash in import_export_decl. */
4025 DECL_INTERFACE_KNOWN (decl) = 1;
4026 return error_mark_node;
4030 DECL_TEMPLATE_RESULT (tmpl) = decl;
4031 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4033 /* Push template declarations for global functions and types. Note
4034 that we do not try to push a global template friend declared in a
4035 template class; such a thing may well depend on the template
4036 parameters of the class. */
4037 if (new_template_p && !ctx
4038 && !(is_friend && template_class_depth (current_class_type) > 0))
4040 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4041 if (tmpl == error_mark_node)
4042 return error_mark_node;
4044 /* Hide template friend classes that haven't been declared yet. */
4045 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4047 DECL_ANTICIPATED (tmpl) = 1;
4048 DECL_FRIEND_P (tmpl) = 1;
4054 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4057 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4058 if (DECL_CONV_FN_P (tmpl))
4060 int depth = TMPL_PARMS_DEPTH (parms);
4062 /* It is a conversion operator. See if the type converted to
4063 depends on innermost template operands. */
4065 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4067 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4070 /* Give template template parms a DECL_CONTEXT of the template
4071 for which they are a parameter. */
4072 parms = INNERMOST_TEMPLATE_PARMS (parms);
4073 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4075 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4076 if (TREE_CODE (parm) == TEMPLATE_DECL)
4077 DECL_CONTEXT (parm) = tmpl;
4081 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4082 back to its most general template. If TMPL is a specialization,
4083 ARGS may only have the innermost set of arguments. Add the missing
4084 argument levels if necessary. */
4085 if (DECL_TEMPLATE_INFO (tmpl))
4086 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4088 info = tree_cons (tmpl, args, NULL_TREE);
4090 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4091 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4092 else if (DECL_LANG_SPECIFIC (decl))
4093 DECL_TEMPLATE_INFO (decl) = info;
4095 return DECL_TEMPLATE_RESULT (tmpl);
4099 push_template_decl (tree decl)
4101 return push_template_decl_real (decl, false);
4104 /* Called when a class template TYPE is redeclared with the indicated
4105 template PARMS, e.g.:
4107 template <class T> struct S;
4108 template <class T> struct S {}; */
4111 redeclare_class_template (tree type, tree parms)
4117 if (!TYPE_TEMPLATE_INFO (type))
4119 error ("%qT is not a template type", type);
4123 tmpl = TYPE_TI_TEMPLATE (type);
4124 if (!PRIMARY_TEMPLATE_P (tmpl))
4125 /* The type is nested in some template class. Nothing to worry
4126 about here; there are no new template parameters for the nested
4132 error ("template specifiers not specified in declaration of %qD",
4137 parms = INNERMOST_TEMPLATE_PARMS (parms);
4138 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4140 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4142 error ("redeclared with %d template parameter(s)",
4143 TREE_VEC_LENGTH (parms));
4144 inform (input_location, "previous declaration %q+D used %d template parameter(s)",
4145 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4149 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4156 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4157 || TREE_VEC_ELT (parms, i) == error_mark_node)
4160 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4161 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4162 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4163 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4165 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4167 if (tmpl_parm != error_mark_node
4168 && (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
4169 || (TREE_CODE (tmpl_parm) != TYPE_DECL
4170 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
4171 || (TREE_CODE (tmpl_parm) != PARM_DECL
4172 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
4173 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
4174 || (TREE_CODE (tmpl_parm) == PARM_DECL
4175 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
4176 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))))))
4178 error ("template parameter %q+#D", tmpl_parm);
4179 error ("redeclared here as %q#D", parm);
4183 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
4185 /* We have in [temp.param]:
4187 A template-parameter may not be given default arguments
4188 by two different declarations in the same scope. */
4189 error ("redefinition of default argument for %q#D", parm);
4190 inform (input_location, "%Joriginal definition appeared here", tmpl_parm);
4194 if (parm_default != NULL_TREE)
4195 /* Update the previous template parameters (which are the ones
4196 that will really count) with the new default value. */
4197 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
4198 else if (tmpl_default != NULL_TREE)
4199 /* Update the new parameters, too; they'll be used as the
4200 parameters for any members. */
4201 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
4207 /* Simplify EXPR if it is a non-dependent expression. Returns the
4208 (possibly simplified) expression. */
4211 fold_non_dependent_expr (tree expr)
4213 if (expr == NULL_TREE)
4216 /* If we're in a template, but EXPR isn't value dependent, simplify
4217 it. We're supposed to treat:
4219 template <typename T> void f(T[1 + 1]);
4220 template <typename T> void f(T[2]);
4222 as two declarations of the same function, for example. */
4223 if (processing_template_decl
4224 && !type_dependent_expression_p (expr)
4225 && !value_dependent_expression_p (expr))
4227 HOST_WIDE_INT saved_processing_template_decl;
4229 saved_processing_template_decl = processing_template_decl;
4230 processing_template_decl = 0;
4231 expr = tsubst_copy_and_build (expr,
4234 /*in_decl=*/NULL_TREE,
4235 /*function_p=*/false,
4236 /*integral_constant_expression_p=*/true);
4237 processing_template_decl = saved_processing_template_decl;
4242 /* EXPR is an expression which is used in a constant-expression context.
4243 For instance, it could be a VAR_DECL with a constant initializer.
4244 Extract the innermost constant expression.
4246 This is basically a more powerful version of
4247 integral_constant_value, which can be used also in templates where
4248 initializers can maintain a syntactic rather than semantic form
4249 (even if they are non-dependent, for access-checking purposes). */
4252 fold_decl_constant_value (tree expr)
4254 tree const_expr = expr;
4257 expr = fold_non_dependent_expr (const_expr);
4258 const_expr = integral_constant_value (expr);
4260 while (expr != const_expr);
4265 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4266 must be a function or a pointer-to-function type, as specified
4267 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4268 and check that the resulting function has external linkage. */
4271 convert_nontype_argument_function (tree type, tree expr)
4276 fn = instantiate_type (type, fns, tf_none);
4277 if (fn == error_mark_node)
4278 return error_mark_node;
4281 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
4282 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
4283 if (TREE_CODE (fn_no_ptr) == BASELINK)
4284 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
4286 /* [temp.arg.nontype]/1
4288 A template-argument for a non-type, non-template template-parameter
4291 -- the address of an object or function with external linkage. */
4292 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
4294 error ("%qE is not a valid template argument for type %qT "
4295 "because function %qD has not external linkage",
4296 expr, type, fn_no_ptr);
4303 /* Attempt to convert the non-type template parameter EXPR to the
4304 indicated TYPE. If the conversion is successful, return the
4305 converted value. If the conversion is unsuccessful, return
4306 NULL_TREE if we issued an error message, or error_mark_node if we
4307 did not. We issue error messages for out-and-out bad template
4308 parameters, but not simply because the conversion failed, since we
4309 might be just trying to do argument deduction. Both TYPE and EXPR
4310 must be non-dependent.
4312 The conversion follows the special rules described in
4313 [temp.arg.nontype], and it is much more strict than an implicit
4316 This function is called twice for each template argument (see
4317 lookup_template_class for a more accurate description of this
4318 problem). This means that we need to handle expressions which
4319 are not valid in a C++ source, but can be created from the
4320 first call (for instance, casts to perform conversions). These
4321 hacks can go away after we fix the double coercion problem. */
4324 convert_nontype_argument (tree type, tree expr)
4328 /* Detect immediately string literals as invalid non-type argument.
4329 This special-case is not needed for correctness (we would easily
4330 catch this later), but only to provide better diagnostic for this
4331 common user mistake. As suggested by DR 100, we do not mention
4332 linkage issues in the diagnostic as this is not the point. */
4333 if (TREE_CODE (expr) == STRING_CST)
4335 error ("%qE is not a valid template argument for type %qT "
4336 "because string literals can never be used in this context",
4341 /* If we are in a template, EXPR may be non-dependent, but still
4342 have a syntactic, rather than semantic, form. For example, EXPR
4343 might be a SCOPE_REF, rather than the VAR_DECL to which the
4344 SCOPE_REF refers. Preserving the qualifying scope is necessary
4345 so that access checking can be performed when the template is
4346 instantiated -- but here we need the resolved form so that we can
4347 convert the argument. */
4348 expr = fold_non_dependent_expr (expr);
4349 if (error_operand_p (expr))
4350 return error_mark_node;
4351 expr_type = TREE_TYPE (expr);
4353 /* HACK: Due to double coercion, we can get a
4354 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4355 which is the tree that we built on the first call (see
4356 below when coercing to reference to object or to reference to
4357 function). We just strip everything and get to the arg.
4358 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4360 if (TREE_CODE (expr) == NOP_EXPR)
4362 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
4364 /* ??? Maybe we could use convert_from_reference here, but we
4365 would need to relax its constraints because the NOP_EXPR
4366 could actually change the type to something more cv-qualified,
4367 and this is not folded by convert_from_reference. */
4368 tree addr = TREE_OPERAND (expr, 0);
4369 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
4370 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
4371 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
4372 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4373 (TREE_TYPE (expr_type),
4374 TREE_TYPE (TREE_TYPE (addr))));
4376 expr = TREE_OPERAND (addr, 0);
4377 expr_type = TREE_TYPE (expr);
4380 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4381 parameter is a pointer to object, through decay and
4382 qualification conversion. Let's strip everything. */
4383 else if (TYPE_PTROBV_P (type))
4386 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
4387 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
4388 /* Skip the ADDR_EXPR only if it is part of the decay for
4389 an array. Otherwise, it is part of the original argument
4390 in the source code. */
4391 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
4392 expr = TREE_OPERAND (expr, 0);
4393 expr_type = TREE_TYPE (expr);
4397 /* [temp.arg.nontype]/5, bullet 1
4399 For a non-type template-parameter of integral or enumeration type,
4400 integral promotions (_conv.prom_) and integral conversions
4401 (_conv.integral_) are applied. */
4402 if (INTEGRAL_TYPE_P (type))
4404 if (!INTEGRAL_TYPE_P (expr_type))
4405 return error_mark_node;
4407 expr = fold_decl_constant_value (expr);
4408 /* Notice that there are constant expressions like '4 % 0' which
4409 do not fold into integer constants. */
4410 if (TREE_CODE (expr) != INTEGER_CST)
4412 error ("%qE is not a valid template argument for type %qT "
4413 "because it is a non-constant expression", expr, type);
4417 /* At this point, an implicit conversion does what we want,
4418 because we already know that the expression is of integral
4420 expr = ocp_convert (type, expr, CONV_IMPLICIT, LOOKUP_PROTECT);
4421 if (expr == error_mark_node)
4422 return error_mark_node;
4424 /* Conversion was allowed: fold it to a bare integer constant. */
4427 /* [temp.arg.nontype]/5, bullet 2
4429 For a non-type template-parameter of type pointer to object,
4430 qualification conversions (_conv.qual_) and the array-to-pointer
4431 conversion (_conv.array_) are applied. */
4432 else if (TYPE_PTROBV_P (type))
4434 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
4436 A template-argument for a non-type, non-template template-parameter
4437 shall be one of: [...]
4439 -- the name of a non-type template-parameter;
4440 -- the address of an object or function with external linkage, [...]
4441 expressed as "& id-expression" where the & is optional if the name
4442 refers to a function or array, or if the corresponding
4443 template-parameter is a reference.
4445 Here, we do not care about functions, as they are invalid anyway
4446 for a parameter of type pointer-to-object. */
4448 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
4449 /* Non-type template parameters are OK. */
4451 else if (TREE_CODE (expr) != ADDR_EXPR
4452 && TREE_CODE (expr_type) != ARRAY_TYPE)
4454 if (TREE_CODE (expr) == VAR_DECL)
4456 error ("%qD is not a valid template argument "
4457 "because %qD is a variable, not the address of "
4462 /* Other values, like integer constants, might be valid
4463 non-type arguments of some other type. */
4464 return error_mark_node;
4470 decl = ((TREE_CODE (expr) == ADDR_EXPR)
4471 ? TREE_OPERAND (expr, 0) : expr);
4472 if (TREE_CODE (decl) != VAR_DECL)
4474 error ("%qE is not a valid template argument of type %qT "
4475 "because %qE is not a variable",
4479 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
4481 error ("%qE is not a valid template argument of type %qT "
4482 "because %qD does not have external linkage",
4488 expr = decay_conversion (expr);
4489 if (expr == error_mark_node)
4490 return error_mark_node;
4492 expr = perform_qualification_conversions (type, expr);
4493 if (expr == error_mark_node)
4494 return error_mark_node;
4496 /* [temp.arg.nontype]/5, bullet 3
4498 For a non-type template-parameter of type reference to object, no
4499 conversions apply. The type referred to by the reference may be more
4500 cv-qualified than the (otherwise identical) type of the
4501 template-argument. The template-parameter is bound directly to the
4502 template-argument, which must be an lvalue. */
4503 else if (TYPE_REF_OBJ_P (type))
4505 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
4507 return error_mark_node;
4509 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
4511 error ("%qE is not a valid template argument for type %qT "
4512 "because of conflicts in cv-qualification", expr, type);
4516 if (!real_lvalue_p (expr))
4518 error ("%qE is not a valid template argument for type %qT "
4519 "because it is not an lvalue", expr, type);
4523 /* [temp.arg.nontype]/1
4525 A template-argument for a non-type, non-template template-parameter
4526 shall be one of: [...]
4528 -- the address of an object or function with external linkage. */
4529 if (!DECL_EXTERNAL_LINKAGE_P (expr))
4531 error ("%qE is not a valid template argument for type %qT "
4532 "because object %qD has not external linkage",
4537 expr = build_nop (type, build_address (expr));
4539 /* [temp.arg.nontype]/5, bullet 4
4541 For a non-type template-parameter of type pointer to function, only
4542 the function-to-pointer conversion (_conv.func_) is applied. If the
4543 template-argument represents a set of overloaded functions (or a
4544 pointer to such), the matching function is selected from the set
4546 else if (TYPE_PTRFN_P (type))
4548 /* If the argument is a template-id, we might not have enough
4549 context information to decay the pointer. */
4550 if (!type_unknown_p (expr_type))
4552 expr = decay_conversion (expr);
4553 if (expr == error_mark_node)
4554 return error_mark_node;
4557 expr = convert_nontype_argument_function (type, expr);
4558 if (!expr || expr == error_mark_node)
4561 /* [temp.arg.nontype]/5, bullet 5
4563 For a non-type template-parameter of type reference to function, no
4564 conversions apply. If the template-argument represents a set of
4565 overloaded functions, the matching function is selected from the set
4567 else if (TYPE_REFFN_P (type))
4569 if (TREE_CODE (expr) == ADDR_EXPR)
4571 error ("%qE is not a valid template argument for type %qT "
4572 "because it is a pointer", expr, type);
4573 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
4577 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
4578 if (!expr || expr == error_mark_node)
4581 expr = build_nop (type, build_address (expr));
4583 /* [temp.arg.nontype]/5, bullet 6
4585 For a non-type template-parameter of type pointer to member function,
4586 no conversions apply. If the template-argument represents a set of
4587 overloaded member functions, the matching member function is selected
4588 from the set (_over.over_). */
4589 else if (TYPE_PTRMEMFUNC_P (type))
4591 expr = instantiate_type (type, expr, tf_none);
4592 if (expr == error_mark_node)
4593 return error_mark_node;
4595 /* There is no way to disable standard conversions in
4596 resolve_address_of_overloaded_function (called by
4597 instantiate_type). It is possible that the call succeeded by
4598 converting &B::I to &D::I (where B is a base of D), so we need
4599 to reject this conversion here.
4601 Actually, even if there was a way to disable standard conversions,
4602 it would still be better to reject them here so that we can
4603 provide a superior diagnostic. */
4604 if (!same_type_p (TREE_TYPE (expr), type))
4606 /* Make sure we are just one standard conversion off. */
4607 gcc_assert (can_convert (type, TREE_TYPE (expr)));
4608 error ("%qE is not a valid template argument for type %qT "
4609 "because it is of type %qT", expr, type,
4611 inform (input_location, "standard conversions are not allowed in this context");
4615 /* [temp.arg.nontype]/5, bullet 7
4617 For a non-type template-parameter of type pointer to data member,
4618 qualification conversions (_conv.qual_) are applied. */
4619 else if (TYPE_PTRMEM_P (type))
4621 expr = perform_qualification_conversions (type, expr);
4622 if (expr == error_mark_node)
4625 /* A template non-type parameter must be one of the above. */
4629 /* Sanity check: did we actually convert the argument to the
4631 gcc_assert (same_type_p (type, TREE_TYPE (expr)));
4635 /* Subroutine of coerce_template_template_parms, which returns 1 if
4636 PARM_PARM and ARG_PARM match using the rule for the template
4637 parameters of template template parameters. Both PARM and ARG are
4638 template parameters; the rest of the arguments are the same as for
4639 coerce_template_template_parms.
4642 coerce_template_template_parm (tree parm,
4644 tsubst_flags_t complain,
4648 if (arg == NULL_TREE || arg == error_mark_node
4649 || parm == NULL_TREE || parm == error_mark_node)
4652 if (TREE_CODE (arg) != TREE_CODE (parm))
4655 switch (TREE_CODE (parm))
4658 /* We encounter instantiations of templates like
4659 template <template <template <class> class> class TT>
4662 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
4663 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
4665 if (!coerce_template_template_parms
4666 (parmparm, argparm, complain, in_decl, outer_args))
4672 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
4673 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
4674 /* Argument is a parameter pack but parameter is not. */
4679 /* The tsubst call is used to handle cases such as
4681 template <int> class C {};
4682 template <class T, template <T> class TT> class D {};
4685 i.e. the parameter list of TT depends on earlier parameters. */
4686 if (!dependent_type_p (TREE_TYPE (arg))
4688 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
4692 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
4693 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
4694 /* Argument is a parameter pack but parameter is not. */
4707 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
4708 template template parameters. Both PARM_PARMS and ARG_PARMS are
4709 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
4712 Consider the example:
4713 template <class T> class A;
4714 template<template <class U> class TT> class B;
4716 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
4717 the parameters to A, and OUTER_ARGS contains A. */
4720 coerce_template_template_parms (tree parm_parms,
4722 tsubst_flags_t complain,
4726 int nparms, nargs, i;
4730 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
4731 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
4733 nparms = TREE_VEC_LENGTH (parm_parms);
4734 nargs = TREE_VEC_LENGTH (arg_parms);
4736 /* Determine whether we have a parameter pack at the end of the
4737 template template parameter's template parameter list. */
4738 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
4740 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
4742 switch (TREE_CODE (parm))
4746 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
4751 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
4761 && !(variadic_p && nargs >= nparms - 1))
4764 /* Check all of the template parameters except the parameter pack at
4765 the end (if any). */
4766 for (i = 0; i < nparms - variadic_p; ++i)
4768 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
4769 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
4772 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
4773 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
4775 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
4783 /* Check each of the template parameters in the template
4784 argument against the template parameter pack at the end of
4785 the template template parameter. */
4786 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
4789 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
4791 for (; i < nargs; ++i)
4793 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
4796 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
4798 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
4807 /* Verifies that the deduced template arguments (in TARGS) for the
4808 template template parameters (in TPARMS) represent valid bindings,
4809 by comparing the template parameter list of each template argument
4810 to the template parameter list of its corresponding template
4811 template parameter, in accordance with DR150. This
4812 routine can only be called after all template arguments have been
4813 deduced. It will return TRUE if all of the template template
4814 parameter bindings are okay, FALSE otherwise. */
4816 template_template_parm_bindings_ok_p (tree tparms, tree targs)
4818 int i, ntparms = TREE_VEC_LENGTH (tparms);
4821 /* We're dealing with template parms in this process. */
4822 ++processing_template_decl;
4824 targs = INNERMOST_TEMPLATE_ARGS (targs);
4826 for (i = 0; i < ntparms; ++i)
4828 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
4829 tree targ = TREE_VEC_ELT (targs, i);
4831 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
4833 tree packed_args = NULL_TREE;
4836 if (ARGUMENT_PACK_P (targ))
4838 /* Look inside the argument pack. */
4839 packed_args = ARGUMENT_PACK_ARGS (targ);
4840 len = TREE_VEC_LENGTH (packed_args);
4843 for (idx = 0; idx < len; ++idx)
4845 tree targ_parms = NULL_TREE;
4848 /* Extract the next argument from the argument
4850 targ = TREE_VEC_ELT (packed_args, idx);
4852 if (PACK_EXPANSION_P (targ))
4853 /* Look at the pattern of the pack expansion. */
4854 targ = PACK_EXPANSION_PATTERN (targ);
4856 /* Extract the template parameters from the template
4858 if (TREE_CODE (targ) == TEMPLATE_DECL)
4859 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
4860 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
4861 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
4863 /* Verify that we can coerce the template template
4864 parameters from the template argument to the template
4865 parameter. This requires an exact match. */
4867 && !coerce_template_template_parms
4868 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
4883 --processing_template_decl;
4887 /* Convert the indicated template ARG as necessary to match the
4888 indicated template PARM. Returns the converted ARG, or
4889 error_mark_node if the conversion was unsuccessful. Error and
4890 warning messages are issued under control of COMPLAIN. This
4891 conversion is for the Ith parameter in the parameter list. ARGS is
4892 the full set of template arguments deduced so far. */
4895 convert_template_argument (tree parm,
4898 tsubst_flags_t complain,
4904 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
4906 if (TREE_CODE (arg) == TREE_LIST
4907 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
4909 /* The template argument was the name of some
4910 member function. That's usually
4911 invalid, but static members are OK. In any
4912 case, grab the underlying fields/functions
4913 and issue an error later if required. */
4914 orig_arg = TREE_VALUE (arg);
4915 TREE_TYPE (arg) = unknown_type_node;
4920 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
4921 requires_type = (TREE_CODE (parm) == TYPE_DECL
4922 || requires_tmpl_type);
4924 /* When determining whether an argument pack expansion is a template,
4925 look at the pattern. */
4926 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
4927 arg = PACK_EXPANSION_PATTERN (arg);
4930 ((TREE_CODE (arg) == TEMPLATE_DECL
4931 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
4932 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
4933 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
4936 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
4937 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
4938 arg = TYPE_STUB_DECL (arg);
4940 is_type = TYPE_P (arg) || is_tmpl_type;
4942 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
4943 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
4945 permerror (input_location, "to refer to a type member of a template parameter, "
4946 "use %<typename %E%>", orig_arg);
4948 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
4949 TREE_OPERAND (arg, 1),
4951 complain & tf_error);
4955 if (is_type != requires_type)
4959 if (complain & tf_error)
4961 error ("type/value mismatch at argument %d in template "
4962 "parameter list for %qD",
4965 error (" expected a constant of type %qT, got %qT",
4967 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
4968 else if (requires_tmpl_type)
4969 error (" expected a class template, got %qE", orig_arg);
4971 error (" expected a type, got %qE", orig_arg);
4974 return error_mark_node;
4976 if (is_tmpl_type ^ requires_tmpl_type)
4978 if (in_decl && (complain & tf_error))
4980 error ("type/value mismatch at argument %d in template "
4981 "parameter list for %qD",
4984 error (" expected a type, got %qT", DECL_NAME (arg));
4986 error (" expected a class template, got %qT", orig_arg);
4988 return error_mark_node;
4993 if (requires_tmpl_type)
4995 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
4996 /* The number of argument required is not known yet.
4997 Just accept it for now. */
4998 val = TREE_TYPE (arg);
5001 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5004 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5006 if (coerce_template_template_parms (parmparm, argparm,
5012 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5014 if (val != error_mark_node)
5016 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
5017 val = TREE_TYPE (val);
5018 else if (TREE_CODE (val) == TYPE_PACK_EXPANSION
5019 && DECL_TEMPLATE_TEMPLATE_PARM_P (arg))
5021 val = TREE_TYPE (arg);
5022 val = make_pack_expansion (val);
5028 if (in_decl && (complain & tf_error))
5030 error ("type/value mismatch at argument %d in "
5031 "template parameter list for %qD",
5033 error (" expected a template of type %qD, got %qD",
5037 val = error_mark_node;
5043 /* We only form one instance of each template specialization.
5044 Therefore, if we use a non-canonical variant (i.e., a
5045 typedef), any future messages referring to the type will use
5046 the typedef, which is confusing if those future uses do not
5047 themselves also use the typedef. */
5049 val = canonical_type_variant (val);
5053 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
5055 if (invalid_nontype_parm_type_p (t, complain))
5056 return error_mark_node;
5058 if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
5059 /* We used to call digest_init here. However, digest_init
5060 will report errors, which we don't want when complain
5061 is zero. More importantly, digest_init will try too
5062 hard to convert things: for example, `0' should not be
5063 converted to pointer type at this point according to
5064 the standard. Accepting this is not merely an
5065 extension, since deciding whether or not these
5066 conversions can occur is part of determining which
5067 function template to call, or whether a given explicit
5068 argument specification is valid. */
5069 val = convert_nontype_argument (t, orig_arg);
5073 if (val == NULL_TREE)
5074 val = error_mark_node;
5075 else if (val == error_mark_node && (complain & tf_error))
5076 error ("could not convert template argument %qE to %qT", orig_arg, t);
5082 /* Coerces the remaining template arguments in INNER_ARGS (from
5083 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5084 Returns the coerced argument pack. PARM_IDX is the position of this
5085 parameter in the template parameter list. ARGS is the original
5086 template argument list. */
5088 coerce_template_parameter_pack (tree parms,
5096 tsubst_flags_t complain)
5098 tree parm = TREE_VEC_ELT (parms, parm_idx);
5099 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5102 tree packed_types = NULL_TREE;
5104 if (arg_idx > nargs)
5107 packed_args = make_tree_vec (nargs - arg_idx);
5109 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
5110 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
5112 /* When the template parameter is a non-type template
5113 parameter pack whose type uses parameter packs, we need
5114 to look at each of the template arguments
5115 separately. Build a vector of the types for these
5116 non-type template parameters in PACKED_TYPES. */
5118 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
5119 packed_types = tsubst_pack_expansion (expansion, args,
5122 if (packed_types == error_mark_node)
5123 return error_mark_node;
5125 /* Check that we have the right number of arguments. */
5127 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
5128 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
5131 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
5132 error ("wrong number of template arguments (%d, should be %d)",
5133 nargs, needed_parms);
5134 return error_mark_node;
5137 /* If we aren't able to check the actual arguments now
5138 (because they haven't been expanded yet), we can at least
5139 verify that all of the types used for the non-type
5140 template parameter pack are, in fact, valid for non-type
5141 template parameters. */
5143 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
5145 int j, len = TREE_VEC_LENGTH (packed_types);
5146 for (j = 0; j < len; ++j)
5148 tree t = TREE_VEC_ELT (packed_types, j);
5149 if (invalid_nontype_parm_type_p (t, complain))
5150 return error_mark_node;
5155 /* Convert the remaining arguments, which will be a part of the
5156 parameter pack "parm". */
5157 for (; arg_idx < nargs; ++arg_idx)
5159 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
5160 tree actual_parm = TREE_VALUE (parm);
5162 if (packed_types && !PACK_EXPANSION_P (arg))
5164 /* When we have a vector of types (corresponding to the
5165 non-type template parameter pack that uses parameter
5166 packs in its type, as mention above), and the
5167 argument is not an expansion (which expands to a
5168 currently unknown number of arguments), clone the
5169 parm and give it the next type in PACKED_TYPES. */
5170 actual_parm = copy_node (actual_parm);
5171 TREE_TYPE (actual_parm) =
5172 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
5175 if (arg != error_mark_node)
5176 arg = convert_template_argument (actual_parm,
5177 arg, new_args, complain, parm_idx,
5179 if (arg == error_mark_node)
5181 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
5184 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
5185 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
5186 argument_pack = make_node (TYPE_ARGUMENT_PACK);
5189 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
5190 TREE_TYPE (argument_pack)
5191 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
5192 TREE_CONSTANT (argument_pack) = 1;
5195 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
5196 return argument_pack;
5199 /* Convert all template arguments to their appropriate types, and
5200 return a vector containing the innermost resulting template
5201 arguments. If any error occurs, return error_mark_node. Error and
5202 warning messages are issued under control of COMPLAIN.
5204 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5205 for arguments not specified in ARGS. Otherwise, if
5206 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5207 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5208 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5212 coerce_template_parms (tree parms,
5215 tsubst_flags_t complain,
5216 bool require_all_args,
5217 bool use_default_args)
5219 int nparms, nargs, parm_idx, arg_idx, lost = 0;
5222 tree new_inner_args;
5223 bool saved_skip_evaluation;
5225 /* When used as a boolean value, indicates whether this is a
5226 variadic template parameter list. Since it's an int, we can also
5227 subtract it from nparms to get the number of non-variadic
5232 = expand_template_argument_pack (INNERMOST_TEMPLATE_ARGS (args));
5234 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5235 nparms = TREE_VEC_LENGTH (parms);
5237 /* Determine if there are any parameter packs. */
5238 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
5240 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
5241 if (template_parameter_pack_p (tparm))
5248 if ((nargs > nparms - variadic_p && !variadic_p)
5249 || (nargs < nparms - variadic_p
5251 && (!use_default_args
5252 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
5253 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
5255 if (complain & tf_error)
5257 const char *or_more = "";
5260 or_more = " or more";
5264 error ("wrong number of template arguments (%d, should be %d%s)",
5265 nargs, nparms, or_more);
5268 error ("provided for %q+D", in_decl);
5271 return error_mark_node;
5274 /* We need to evaluate the template arguments, even though this
5275 template-id may be nested within a "sizeof". */
5276 saved_skip_evaluation = skip_evaluation;
5277 skip_evaluation = false;
5278 new_inner_args = make_tree_vec (nparms);
5279 new_args = add_outermost_template_args (args, new_inner_args);
5280 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
5285 /* Get the Ith template parameter. */
5286 parm = TREE_VEC_ELT (parms, parm_idx);
5288 if (parm == error_mark_node)
5290 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
5294 /* Calculate the next argument. */
5295 if (template_parameter_pack_p (TREE_VALUE (parm)))
5297 /* All remaining arguments will be placed in the
5298 template parameter pack PARM. */
5299 arg = coerce_template_parameter_pack (parms, parm_idx, args,
5300 inner_args, arg_idx,
5304 /* Store this argument. */
5305 if (arg == error_mark_node)
5307 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
5309 /* We are done with all of the arguments. */
5314 else if (arg_idx < nargs)
5316 arg = TREE_VEC_ELT (inner_args, arg_idx);
5318 if (arg && PACK_EXPANSION_P (arg))
5320 if (complain & tf_error)
5322 /* If ARG is a pack expansion, but PARM is not a
5323 template parameter pack (if it were, we would have
5324 handled it above), we're trying to expand into a
5325 fixed-length argument list. */
5326 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
5327 error ("cannot expand %<%E%> into a fixed-length "
5328 "argument list", arg);
5330 error ("cannot expand %<%T%> into a fixed-length "
5331 "argument list", arg);
5333 return error_mark_node;
5336 else if (require_all_args)
5337 /* There must be a default arg in this case. */
5338 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
5343 if (arg == error_mark_node)
5345 if (complain & tf_error)
5346 error ("template argument %d is invalid", arg_idx + 1);
5349 /* This only occurs if there was an error in the template
5350 parameter list itself (which we would already have
5351 reported) that we are trying to recover from, e.g., a class
5352 template with a parameter list such as
5353 template<typename..., typename>. */
5354 return error_mark_node;
5356 arg = convert_template_argument (TREE_VALUE (parm),
5357 arg, new_args, complain,
5360 if (arg == error_mark_node)
5362 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
5364 skip_evaluation = saved_skip_evaluation;
5367 return error_mark_node;
5369 return new_inner_args;
5372 /* Returns 1 if template args OT and NT are equivalent. */
5375 template_args_equal (tree ot, tree nt)
5380 if (TREE_CODE (nt) == TREE_VEC)
5381 /* For member templates */
5382 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
5383 else if (PACK_EXPANSION_P (ot))
5384 return PACK_EXPANSION_P (nt)
5385 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
5386 PACK_EXPANSION_PATTERN (nt));
5387 else if (TYPE_P (nt))
5388 return TYPE_P (ot) && same_type_p (ot, nt);
5389 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
5392 return cp_tree_equal (ot, nt);
5395 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
5396 of template arguments. Returns 0 otherwise. */
5399 comp_template_args (tree oldargs, tree newargs)
5403 oldargs = expand_template_argument_pack (oldargs);
5404 newargs = expand_template_argument_pack (newargs);
5406 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
5409 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
5411 tree nt = TREE_VEC_ELT (newargs, i);
5412 tree ot = TREE_VEC_ELT (oldargs, i);
5414 if (! template_args_equal (ot, nt))
5421 add_pending_template (tree d)
5423 tree ti = (TYPE_P (d)
5424 ? CLASSTYPE_TEMPLATE_INFO (d)
5425 : DECL_TEMPLATE_INFO (d));
5426 struct pending_template *pt;
5429 if (TI_PENDING_TEMPLATE_FLAG (ti))
5432 /* We are called both from instantiate_decl, where we've already had a
5433 tinst_level pushed, and instantiate_template, where we haven't.
5435 level = !current_tinst_level || current_tinst_level->decl != d;
5438 push_tinst_level (d);
5440 pt = GGC_NEW (struct pending_template);
5442 pt->tinst = current_tinst_level;
5443 if (last_pending_template)
5444 last_pending_template->next = pt;
5446 pending_templates = pt;
5448 last_pending_template = pt;
5450 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
5457 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
5458 ARGLIST. Valid choices for FNS are given in the cp-tree.def
5459 documentation for TEMPLATE_ID_EXPR. */
5462 lookup_template_function (tree fns, tree arglist)
5466 if (fns == error_mark_node || arglist == error_mark_node)
5467 return error_mark_node;
5469 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
5470 gcc_assert (fns && (is_overloaded_fn (fns)
5471 || TREE_CODE (fns) == IDENTIFIER_NODE));
5473 if (BASELINK_P (fns))
5475 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
5477 BASELINK_FUNCTIONS (fns),
5482 type = TREE_TYPE (fns);
5483 if (TREE_CODE (fns) == OVERLOAD || !type)
5484 type = unknown_type_node;
5486 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
5489 /* Within the scope of a template class S<T>, the name S gets bound
5490 (in build_self_reference) to a TYPE_DECL for the class, not a
5491 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
5492 or one of its enclosing classes, and that type is a template,
5493 return the associated TEMPLATE_DECL. Otherwise, the original
5494 DECL is returned. */
5497 maybe_get_template_decl_from_type_decl (tree decl)
5499 return (decl != NULL_TREE
5500 && TREE_CODE (decl) == TYPE_DECL
5501 && DECL_ARTIFICIAL (decl)
5502 && CLASS_TYPE_P (TREE_TYPE (decl))
5503 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
5504 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
5507 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
5508 parameters, find the desired type.
5510 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
5512 IN_DECL, if non-NULL, is the template declaration we are trying to
5515 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
5516 the class we are looking up.
5518 Issue error and warning messages under control of COMPLAIN.
5520 If the template class is really a local class in a template
5521 function, then the FUNCTION_CONTEXT is the function in which it is
5524 ??? Note that this function is currently called *twice* for each
5525 template-id: the first time from the parser, while creating the
5526 incomplete type (finish_template_type), and the second type during the
5527 real instantiation (instantiate_template_class). This is surely something
5528 that we want to avoid. It also causes some problems with argument
5529 coercion (see convert_nontype_argument for more information on this). */
5532 lookup_template_class (tree d1,
5537 tsubst_flags_t complain)
5539 tree templ = NULL_TREE, parmlist;
5542 timevar_push (TV_NAME_LOOKUP);
5544 if (TREE_CODE (d1) == IDENTIFIER_NODE)
5546 tree value = innermost_non_namespace_value (d1);
5547 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
5552 push_decl_namespace (context);
5553 templ = lookup_name (d1);
5554 templ = maybe_get_template_decl_from_type_decl (templ);
5556 pop_decl_namespace ();
5559 context = DECL_CONTEXT (templ);
5561 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
5563 tree type = TREE_TYPE (d1);
5565 /* If we are declaring a constructor, say A<T>::A<T>, we will get
5566 an implicit typename for the second A. Deal with it. */
5567 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
5568 type = TREE_TYPE (type);
5570 if (CLASSTYPE_TEMPLATE_INFO (type))
5572 templ = CLASSTYPE_TI_TEMPLATE (type);
5573 d1 = DECL_NAME (templ);
5576 else if (TREE_CODE (d1) == ENUMERAL_TYPE
5577 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
5579 templ = TYPE_TI_TEMPLATE (d1);
5580 d1 = DECL_NAME (templ);
5582 else if (TREE_CODE (d1) == TEMPLATE_DECL
5583 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
5586 d1 = DECL_NAME (templ);
5587 context = DECL_CONTEXT (templ);
5590 /* Issue an error message if we didn't find a template. */
5593 if (complain & tf_error)
5594 error ("%qT is not a template", d1);
5595 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5598 if (TREE_CODE (templ) != TEMPLATE_DECL
5599 /* Make sure it's a user visible template, if it was named by
5601 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
5602 && !PRIMARY_TEMPLATE_P (templ)))
5604 if (complain & tf_error)
5606 error ("non-template type %qT used as a template", d1);
5608 error ("for template declaration %q+D", in_decl);
5610 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5613 complain &= ~tf_user;
5615 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
5617 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
5618 template arguments */
5624 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
5626 /* Consider an example where a template template parameter declared as
5628 template <class T, class U = std::allocator<T> > class TT
5630 The template parameter level of T and U are one level larger than
5631 of TT. To proper process the default argument of U, say when an
5632 instantiation `TT<int>' is seen, we need to build the full
5633 arguments containing {int} as the innermost level. Outer levels,
5634 available when not appearing as default template argument, can be
5635 obtained from the arguments of the enclosing template.
5637 Suppose that TT is later substituted with std::vector. The above
5638 instantiation is `TT<int, std::allocator<T> >' with TT at
5639 level 1, and T at level 2, while the template arguments at level 1
5640 becomes {std::vector} and the inner level 2 is {int}. */
5642 outer = DECL_CONTEXT (templ);
5644 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
5645 else if (current_template_parms)
5646 /* This is an argument of the current template, so we haven't set
5647 DECL_CONTEXT yet. */
5648 outer = current_template_args ();
5651 arglist = add_to_template_args (outer, arglist);
5653 arglist2 = coerce_template_parms (parmlist, arglist, templ,
5655 /*require_all_args=*/true,
5656 /*use_default_args=*/true);
5657 if (arglist2 == error_mark_node
5658 || (!uses_template_parms (arglist2)
5659 && check_instantiated_args (templ, arglist2, complain)))
5660 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5662 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
5663 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
5667 tree template_type = TREE_TYPE (templ);
5670 tree found = NULL_TREE;
5673 int is_partial_instantiation;
5675 gen_tmpl = most_general_template (templ);
5676 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
5677 parm_depth = TMPL_PARMS_DEPTH (parmlist);
5678 arg_depth = TMPL_ARGS_DEPTH (arglist);
5680 if (arg_depth == 1 && parm_depth > 1)
5682 /* We've been given an incomplete set of template arguments.
5685 template <class T> struct S1 {
5686 template <class U> struct S2 {};
5687 template <class U> struct S2<U*> {};
5690 we will be called with an ARGLIST of `U*', but the
5691 TEMPLATE will be `template <class T> template
5692 <class U> struct S1<T>::S2'. We must fill in the missing
5695 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
5697 arg_depth = TMPL_ARGS_DEPTH (arglist);
5700 /* Now we should have enough arguments. */
5701 gcc_assert (parm_depth == arg_depth);
5703 /* From here on, we're only interested in the most general
5707 /* Calculate the BOUND_ARGS. These will be the args that are
5708 actually tsubst'd into the definition to create the
5712 /* We have multiple levels of arguments to coerce, at once. */
5714 int saved_depth = TMPL_ARGS_DEPTH (arglist);
5716 tree bound_args = make_tree_vec (parm_depth);
5718 for (i = saved_depth,
5719 t = DECL_TEMPLATE_PARMS (templ);
5720 i > 0 && t != NULL_TREE;
5721 --i, t = TREE_CHAIN (t))
5723 tree a = coerce_template_parms (TREE_VALUE (t),
5726 /*require_all_args=*/true,
5727 /*use_default_args=*/true);
5729 /* Don't process further if one of the levels fails. */
5730 if (a == error_mark_node)
5732 /* Restore the ARGLIST to its full size. */
5733 TREE_VEC_LENGTH (arglist) = saved_depth;
5734 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5737 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
5739 /* We temporarily reduce the length of the ARGLIST so
5740 that coerce_template_parms will see only the arguments
5741 corresponding to the template parameters it is
5743 TREE_VEC_LENGTH (arglist)--;
5746 /* Restore the ARGLIST to its full size. */
5747 TREE_VEC_LENGTH (arglist) = saved_depth;
5749 arglist = bound_args;
5753 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
5754 INNERMOST_TEMPLATE_ARGS (arglist),
5757 /*require_all_args=*/true,
5758 /*use_default_args=*/true);
5760 if (arglist == error_mark_node)
5761 /* We were unable to bind the arguments. */
5762 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5764 /* In the scope of a template class, explicit references to the
5765 template class refer to the type of the template, not any
5766 instantiation of it. For example, in:
5768 template <class T> class C { void f(C<T>); }
5770 the `C<T>' is just the same as `C'. Outside of the
5771 class, however, such a reference is an instantiation. */
5772 if (comp_template_args (TYPE_TI_ARGS (template_type),
5775 found = template_type;
5777 if (!entering_scope && PRIMARY_TEMPLATE_P (templ))
5781 for (ctx = current_class_type;
5782 ctx && TREE_CODE (ctx) != NAMESPACE_DECL;
5784 ? TYPE_CONTEXT (ctx)
5785 : DECL_CONTEXT (ctx)))
5786 if (TYPE_P (ctx) && same_type_p (ctx, template_type))
5789 /* We're not in the scope of the class, so the
5790 TEMPLATE_TYPE is not the type we want after all. */
5796 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
5798 /* If we already have this specialization, return it. */
5799 found = retrieve_specialization (templ, arglist,
5800 /*class_specializations_p=*/false);
5802 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
5804 /* This type is a "partial instantiation" if any of the template
5805 arguments still involve template parameters. Note that we set
5806 IS_PARTIAL_INSTANTIATION for partial specializations as
5808 is_partial_instantiation = uses_template_parms (arglist);
5810 /* If the deduced arguments are invalid, then the binding
5812 if (!is_partial_instantiation
5813 && check_instantiated_args (templ,
5814 INNERMOST_TEMPLATE_ARGS (arglist),
5816 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5818 if (!is_partial_instantiation
5819 && !PRIMARY_TEMPLATE_P (templ)
5820 && TREE_CODE (CP_DECL_CONTEXT (templ)) == NAMESPACE_DECL)
5822 found = xref_tag_from_type (TREE_TYPE (templ),
5824 /*tag_scope=*/ts_global);
5825 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
5828 context = tsubst (DECL_CONTEXT (templ), arglist,
5831 context = global_namespace;
5833 /* Create the type. */
5834 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
5836 if (!is_partial_instantiation)
5838 set_current_access_from_decl (TYPE_NAME (template_type));
5839 t = start_enum (TYPE_IDENTIFIER (template_type));
5842 /* We don't want to call start_enum for this type, since
5843 the values for the enumeration constants may involve
5844 template parameters. And, no one should be interested
5845 in the enumeration constants for such a type. */
5846 t = make_node (ENUMERAL_TYPE);
5850 t = make_class_type (TREE_CODE (template_type));
5851 CLASSTYPE_DECLARED_CLASS (t)
5852 = CLASSTYPE_DECLARED_CLASS (template_type);
5853 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
5854 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
5856 /* A local class. Make sure the decl gets registered properly. */
5857 if (context == current_function_decl)
5858 pushtag (DECL_NAME (templ), t, /*tag_scope=*/ts_current);
5860 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
5861 /* This instantiation is another name for the primary
5862 template type. Set the TYPE_CANONICAL field
5864 TYPE_CANONICAL (t) = template_type;
5865 else if (any_template_arguments_need_structural_equality_p (arglist))
5866 /* Some of the template arguments require structural
5867 equality testing, so this template class requires
5868 structural equality testing. */
5869 SET_TYPE_STRUCTURAL_EQUALITY (t);
5872 /* If we called start_enum or pushtag above, this information
5873 will already be set up. */
5876 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
5878 type_decl = create_implicit_typedef (DECL_NAME (templ), t);
5879 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
5880 TYPE_STUB_DECL (t) = type_decl;
5881 DECL_SOURCE_LOCATION (type_decl)
5882 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
5885 type_decl = TYPE_NAME (t);
5887 TREE_PRIVATE (type_decl)
5888 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
5889 TREE_PROTECTED (type_decl)
5890 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
5891 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
5893 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
5894 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
5897 /* Set up the template information. We have to figure out which
5898 template is the immediate parent if this is a full
5900 if (parm_depth == 1 || is_partial_instantiation
5901 || !PRIMARY_TEMPLATE_P (templ))
5902 /* This case is easy; there are no member templates involved. */
5906 /* This is a full instantiation of a member template. Look
5907 for a partial instantiation of which this is an instance. */
5909 for (found = DECL_TEMPLATE_INSTANTIATIONS (templ);
5910 found; found = TREE_CHAIN (found))
5913 tree tmpl = CLASSTYPE_TI_TEMPLATE (TREE_VALUE (found));
5915 /* We only want partial instantiations, here, not
5916 specializations or full instantiations. */
5917 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_VALUE (found))
5918 || !uses_template_parms (TREE_VALUE (found)))
5921 /* Temporarily reduce by one the number of levels in the
5922 ARGLIST and in FOUND so as to avoid comparing the
5923 last set of arguments. */
5924 TREE_VEC_LENGTH (arglist)--;
5925 TREE_VEC_LENGTH (TREE_PURPOSE (found)) --;
5927 /* See if the arguments match. If they do, then TMPL is
5928 the partial instantiation we want. */
5929 success = comp_template_args (TREE_PURPOSE (found), arglist);
5931 /* Restore the argument vectors to their full size. */
5932 TREE_VEC_LENGTH (arglist)++;
5933 TREE_VEC_LENGTH (TREE_PURPOSE (found))++;
5944 /* There was no partial instantiation. This happens
5945 where C<T> is a member template of A<T> and it's used
5948 template <typename T> struct B { A<T>::C<int> m; };
5951 Create the partial instantiation.
5953 TREE_VEC_LENGTH (arglist)--;
5954 found = tsubst (templ, arglist, complain, NULL_TREE);
5955 TREE_VEC_LENGTH (arglist)++;
5959 SET_TYPE_TEMPLATE_INFO (t, tree_cons (found, arglist, NULL_TREE));
5960 DECL_TEMPLATE_INSTANTIATIONS (templ)
5961 = tree_cons (arglist, t,
5962 DECL_TEMPLATE_INSTANTIATIONS (templ));
5964 if (TREE_CODE (t) == ENUMERAL_TYPE
5965 && !is_partial_instantiation)
5966 /* Now that the type has been registered on the instantiations
5967 list, we set up the enumerators. Because the enumeration
5968 constants may involve the enumeration type itself, we make
5969 sure to register the type first, and then create the
5970 constants. That way, doing tsubst_expr for the enumeration
5971 constants won't result in recursive calls here; we'll find
5972 the instantiation and exit above. */
5973 tsubst_enum (template_type, t, arglist);
5975 if (is_partial_instantiation)
5976 /* If the type makes use of template parameters, the
5977 code that generates debugging information will crash. */
5978 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
5980 /* Possibly limit visibility based on template args. */
5981 TREE_PUBLIC (type_decl) = 1;
5982 determine_visibility (type_decl);
5984 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
5986 timevar_pop (TV_NAME_LOOKUP);
5993 /* True when we should also visit template parameters that occur in
5994 non-deduced contexts. */
5995 bool include_nondeduced_p;
5996 struct pointer_set_t *visited;
5999 /* Called from for_each_template_parm via walk_tree. */
6002 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
6005 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
6006 tree_fn_t fn = pfd->fn;
6007 void *data = pfd->data;
6010 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
6011 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
6012 pfd->include_nondeduced_p))
6013 return error_mark_node;
6015 switch (TREE_CODE (t))
6018 if (TYPE_PTRMEMFUNC_P (t))
6024 if (!TYPE_TEMPLATE_INFO (t))
6026 else if (for_each_template_parm (TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
6027 fn, data, pfd->visited,
6028 pfd->include_nondeduced_p))
6029 return error_mark_node;
6033 if (for_each_template_parm (TYPE_MIN_VALUE (t),
6034 fn, data, pfd->visited,
6035 pfd->include_nondeduced_p)
6036 || for_each_template_parm (TYPE_MAX_VALUE (t),
6037 fn, data, pfd->visited,
6038 pfd->include_nondeduced_p))
6039 return error_mark_node;
6043 /* Since we're not going to walk subtrees, we have to do this
6045 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
6046 pfd->visited, pfd->include_nondeduced_p))
6047 return error_mark_node;
6051 /* Check the return type. */
6052 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6053 pfd->include_nondeduced_p))
6054 return error_mark_node;
6056 /* Check the parameter types. Since default arguments are not
6057 instantiated until they are needed, the TYPE_ARG_TYPES may
6058 contain expressions that involve template parameters. But,
6059 no-one should be looking at them yet. And, once they're
6060 instantiated, they don't contain template parameters, so
6061 there's no point in looking at them then, either. */
6065 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
6066 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
6067 pfd->visited, pfd->include_nondeduced_p))
6068 return error_mark_node;
6070 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6071 want walk_tree walking into them itself. */
6077 if (pfd->include_nondeduced_p
6078 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
6080 pfd->include_nondeduced_p))
6081 return error_mark_node;
6086 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
6087 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
6088 pfd->visited, pfd->include_nondeduced_p))
6089 return error_mark_node;
6094 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
6095 && for_each_template_parm (DECL_INITIAL (t), fn, data,
6096 pfd->visited, pfd->include_nondeduced_p))
6097 return error_mark_node;
6098 if (DECL_CONTEXT (t)
6099 && pfd->include_nondeduced_p
6100 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
6101 pfd->visited, pfd->include_nondeduced_p))
6102 return error_mark_node;
6105 case BOUND_TEMPLATE_TEMPLATE_PARM:
6106 /* Record template parameters such as `T' inside `TT<T>'. */
6107 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
6108 pfd->include_nondeduced_p))
6109 return error_mark_node;
6112 case TEMPLATE_TEMPLATE_PARM:
6113 case TEMPLATE_TYPE_PARM:
6114 case TEMPLATE_PARM_INDEX:
6115 if (fn && (*fn)(t, data))
6116 return error_mark_node;
6118 return error_mark_node;
6122 /* A template template parameter is encountered. */
6123 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
6124 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6125 pfd->include_nondeduced_p))
6126 return error_mark_node;
6128 /* Already substituted template template parameter */
6134 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
6136 pfd->include_nondeduced_p))
6137 return error_mark_node;
6141 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
6142 && pfd->include_nondeduced_p
6143 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
6144 (TREE_TYPE (t)), fn, data,
6145 pfd->visited, pfd->include_nondeduced_p))
6146 return error_mark_node;
6151 /* If there's no type, then this thing must be some expression
6152 involving template parameters. */
6153 if (!fn && !TREE_TYPE (t))
6154 return error_mark_node;
6159 case REINTERPRET_CAST_EXPR:
6160 case CONST_CAST_EXPR:
6161 case STATIC_CAST_EXPR:
6162 case DYNAMIC_CAST_EXPR:
6166 case PSEUDO_DTOR_EXPR:
6168 return error_mark_node;
6175 /* We didn't find any template parameters we liked. */
6179 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6180 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6181 call FN with the parameter and the DATA.
6182 If FN returns nonzero, the iteration is terminated, and
6183 for_each_template_parm returns 1. Otherwise, the iteration
6184 continues. If FN never returns a nonzero value, the value
6185 returned by for_each_template_parm is 0. If FN is NULL, it is
6186 considered to be the function which always returns 1.
6188 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6189 parameters that occur in non-deduced contexts. When false, only
6190 visits those template parameters that can be deduced. */
6193 for_each_template_parm (tree t, tree_fn_t fn, void* data,
6194 struct pointer_set_t *visited,
6195 bool include_nondeduced_p)
6197 struct pair_fn_data pfd;
6203 pfd.include_nondeduced_p = include_nondeduced_p;
6205 /* Walk the tree. (Conceptually, we would like to walk without
6206 duplicates, but for_each_template_parm_r recursively calls
6207 for_each_template_parm, so we would need to reorganize a fair
6208 bit to use walk_tree_without_duplicates, so we keep our own
6211 pfd.visited = visited;
6213 pfd.visited = pointer_set_create ();
6214 result = cp_walk_tree (&t,
6215 for_each_template_parm_r,
6217 pfd.visited) != NULL_TREE;
6222 pointer_set_destroy (pfd.visited);
6229 /* Returns true if T depends on any template parameter. */
6232 uses_template_parms (tree t)
6235 int saved_processing_template_decl;
6237 saved_processing_template_decl = processing_template_decl;
6238 if (!saved_processing_template_decl)
6239 processing_template_decl = 1;
6241 dependent_p = dependent_type_p (t);
6242 else if (TREE_CODE (t) == TREE_VEC)
6243 dependent_p = any_dependent_template_arguments_p (t);
6244 else if (TREE_CODE (t) == TREE_LIST)
6245 dependent_p = (uses_template_parms (TREE_VALUE (t))
6246 || uses_template_parms (TREE_CHAIN (t)));
6247 else if (TREE_CODE (t) == TYPE_DECL)
6248 dependent_p = dependent_type_p (TREE_TYPE (t));
6251 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
6252 || TREE_CODE (t) == OVERLOAD
6253 || TREE_CODE (t) == BASELINK
6254 || TREE_CODE (t) == IDENTIFIER_NODE
6255 || TREE_CODE (t) == TRAIT_EXPR
6256 || CONSTANT_CLASS_P (t))
6257 dependent_p = (type_dependent_expression_p (t)
6258 || value_dependent_expression_p (t));
6261 gcc_assert (t == error_mark_node);
6262 dependent_p = false;
6265 processing_template_decl = saved_processing_template_decl;
6270 /* Returns true if T depends on any template parameter with level LEVEL. */
6273 uses_template_parms_level (tree t, int level)
6275 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
6276 /*include_nondeduced_p=*/true);
6279 static int tinst_depth;
6280 extern int max_tinst_depth;
6281 #ifdef GATHER_STATISTICS
6284 static int tinst_level_tick;
6285 static int last_template_error_tick;
6287 /* We're starting to instantiate D; record the template instantiation context
6288 for diagnostics and to restore it later. */
6291 push_tinst_level (tree d)
6293 struct tinst_level *new_level;
6295 if (tinst_depth >= max_tinst_depth)
6297 /* If the instantiation in question still has unbound template parms,
6298 we don't really care if we can't instantiate it, so just return.
6299 This happens with base instantiation for implicit `typename'. */
6300 if (uses_template_parms (d))
6303 last_template_error_tick = tinst_level_tick;
6304 error ("template instantiation depth exceeds maximum of %d (use "
6305 "-ftemplate-depth-NN to increase the maximum) instantiating %qD",
6306 max_tinst_depth, d);
6308 print_instantiation_context ();
6313 new_level = GGC_NEW (struct tinst_level);
6314 new_level->decl = d;
6315 new_level->locus = input_location;
6316 new_level->in_system_header_p = in_system_header;
6317 new_level->next = current_tinst_level;
6318 current_tinst_level = new_level;
6321 #ifdef GATHER_STATISTICS
6322 if (tinst_depth > depth_reached)
6323 depth_reached = tinst_depth;
6330 /* We're done instantiating this template; return to the instantiation
6334 pop_tinst_level (void)
6336 /* Restore the filename and line number stashed away when we started
6337 this instantiation. */
6338 input_location = current_tinst_level->locus;
6339 current_tinst_level = current_tinst_level->next;
6344 /* We're instantiating a deferred template; restore the template
6345 instantiation context in which the instantiation was requested, which
6346 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
6349 reopen_tinst_level (struct tinst_level *level)
6351 struct tinst_level *t;
6354 for (t = level; t; t = t->next)
6357 current_tinst_level = level;
6362 /* Returns the TINST_LEVEL which gives the original instantiation
6365 struct tinst_level *
6366 outermost_tinst_level (void)
6368 struct tinst_level *level = current_tinst_level;
6371 level = level->next;
6375 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
6376 vector of template arguments, as for tsubst.
6378 Returns an appropriate tsubst'd friend declaration. */
6381 tsubst_friend_function (tree decl, tree args)
6385 if (TREE_CODE (decl) == FUNCTION_DECL
6386 && DECL_TEMPLATE_INSTANTIATION (decl)
6387 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
6388 /* This was a friend declared with an explicit template
6389 argument list, e.g.:
6393 to indicate that f was a template instantiation, not a new
6394 function declaration. Now, we have to figure out what
6395 instantiation of what template. */
6397 tree template_id, arglist, fns;
6400 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
6402 /* Friend functions are looked up in the containing namespace scope.
6403 We must enter that scope, to avoid finding member functions of the
6404 current class with same name. */
6405 push_nested_namespace (ns);
6406 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
6407 tf_warning_or_error, NULL_TREE,
6408 /*integral_constant_expression_p=*/false);
6409 pop_nested_namespace (ns);
6410 arglist = tsubst (DECL_TI_ARGS (decl), args,
6411 tf_warning_or_error, NULL_TREE);
6412 template_id = lookup_template_function (fns, arglist);
6414 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6415 tmpl = determine_specialization (template_id, new_friend,
6417 /*need_member_template=*/0,
6418 TREE_VEC_LENGTH (args),
6420 return instantiate_template (tmpl, new_args, tf_error);
6423 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6425 /* The NEW_FRIEND will look like an instantiation, to the
6426 compiler, but is not an instantiation from the point of view of
6427 the language. For example, we might have had:
6429 template <class T> struct S {
6430 template <class U> friend void f(T, U);
6433 Then, in S<int>, template <class U> void f(int, U) is not an
6434 instantiation of anything. */
6435 if (new_friend == error_mark_node)
6436 return error_mark_node;
6438 DECL_USE_TEMPLATE (new_friend) = 0;
6439 if (TREE_CODE (decl) == TEMPLATE_DECL)
6441 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
6442 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
6443 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
6446 /* The mangled name for the NEW_FRIEND is incorrect. The function
6447 is not a template instantiation and should not be mangled like
6448 one. Therefore, we forget the mangling here; we'll recompute it
6449 later if we need it. */
6450 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
6452 SET_DECL_RTL (new_friend, NULL_RTX);
6453 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
6456 if (DECL_NAMESPACE_SCOPE_P (new_friend))
6459 tree new_friend_template_info;
6460 tree new_friend_result_template_info;
6462 int new_friend_is_defn;
6464 /* We must save some information from NEW_FRIEND before calling
6465 duplicate decls since that function will free NEW_FRIEND if
6467 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
6468 new_friend_is_defn =
6469 (DECL_INITIAL (DECL_TEMPLATE_RESULT
6470 (template_for_substitution (new_friend)))
6472 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
6474 /* This declaration is a `primary' template. */
6475 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
6477 new_friend_result_template_info
6478 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
6481 new_friend_result_template_info = NULL_TREE;
6483 /* Make the init_value nonzero so pushdecl knows this is a defn. */
6484 if (new_friend_is_defn)
6485 DECL_INITIAL (new_friend) = error_mark_node;
6487 /* Inside pushdecl_namespace_level, we will push into the
6488 current namespace. However, the friend function should go
6489 into the namespace of the template. */
6490 ns = decl_namespace_context (new_friend);
6491 push_nested_namespace (ns);
6492 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
6493 pop_nested_namespace (ns);
6495 if (old_decl == error_mark_node)
6496 return error_mark_node;
6498 if (old_decl != new_friend)
6500 /* This new friend declaration matched an existing
6501 declaration. For example, given:
6503 template <class T> void f(T);
6504 template <class U> class C {
6505 template <class T> friend void f(T) {}
6508 the friend declaration actually provides the definition
6509 of `f', once C has been instantiated for some type. So,
6510 old_decl will be the out-of-class template declaration,
6511 while new_friend is the in-class definition.
6513 But, if `f' was called before this point, the
6514 instantiation of `f' will have DECL_TI_ARGS corresponding
6515 to `T' but not to `U', references to which might appear
6516 in the definition of `f'. Previously, the most general
6517 template for an instantiation of `f' was the out-of-class
6518 version; now it is the in-class version. Therefore, we
6519 run through all specialization of `f', adding to their
6520 DECL_TI_ARGS appropriately. In particular, they need a
6521 new set of outer arguments, corresponding to the
6522 arguments for this class instantiation.
6524 The same situation can arise with something like this:
6527 template <class T> class C {
6531 when `C<int>' is instantiated. Now, `f(int)' is defined
6534 if (!new_friend_is_defn)
6535 /* On the other hand, if the in-class declaration does
6536 *not* provide a definition, then we don't want to alter
6537 existing definitions. We can just leave everything
6542 /* Overwrite whatever template info was there before, if
6543 any, with the new template information pertaining to
6545 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
6547 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
6548 reregister_specialization (new_friend,
6549 most_general_template (old_decl),
6554 tree new_friend_args;
6556 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
6557 = new_friend_result_template_info;
6559 new_friend_args = TI_ARGS (new_friend_template_info);
6560 for (t = DECL_TEMPLATE_SPECIALIZATIONS (old_decl);
6564 tree spec = TREE_VALUE (t);
6567 = add_outermost_template_args (new_friend_args,
6568 DECL_TI_ARGS (spec));
6571 /* Now, since specializations are always supposed to
6572 hang off of the most general template, we must move
6574 t = most_general_template (old_decl);
6577 DECL_TEMPLATE_SPECIALIZATIONS (t)
6578 = chainon (DECL_TEMPLATE_SPECIALIZATIONS (t),
6579 DECL_TEMPLATE_SPECIALIZATIONS (old_decl));
6580 DECL_TEMPLATE_SPECIALIZATIONS (old_decl) = NULL_TREE;
6585 /* The information from NEW_FRIEND has been merged into OLD_DECL
6586 by duplicate_decls. */
6587 new_friend = old_decl;
6592 tree context = DECL_CONTEXT (new_friend);
6596 template <class T> class C {
6597 template <class U> friend void C1<U>::f (); // case 1
6598 friend void C2<T>::f (); // case 2
6600 we only need to make sure CONTEXT is a complete type for
6601 case 2. To distinguish between the two cases, we note that
6602 CONTEXT of case 1 remains dependent type after tsubst while
6603 this isn't true for case 2. */
6604 ++processing_template_decl;
6605 dependent_p = dependent_type_p (context);
6606 --processing_template_decl;
6609 && !complete_type_or_else (context, NULL_TREE))
6610 return error_mark_node;
6612 if (COMPLETE_TYPE_P (context))
6614 /* Check to see that the declaration is really present, and,
6615 possibly obtain an improved declaration. */
6616 tree fn = check_classfn (context,
6617 new_friend, NULL_TREE);
6627 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
6628 template arguments, as for tsubst.
6630 Returns an appropriate tsubst'd friend type or error_mark_node on
6634 tsubst_friend_class (tree friend_tmpl, tree args)
6640 context = DECL_CONTEXT (friend_tmpl);
6644 if (TREE_CODE (context) == NAMESPACE_DECL)
6645 push_nested_namespace (context);
6647 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
6650 /* Look for a class template declaration. We look for hidden names
6651 because two friend declarations of the same template are the
6652 same. For example, in:
6655 template <typename> friend class F;
6657 template <typename> struct B {
6658 template <typename> friend class F;
6661 both F templates are the same. */
6662 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
6663 /*block_p=*/true, 0,
6664 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
6666 /* But, if we don't find one, it might be because we're in a
6667 situation like this:
6675 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
6676 for `S<int>', not the TEMPLATE_DECL. */
6677 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
6679 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
6680 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
6683 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
6685 /* The friend template has already been declared. Just
6686 check to see that the declarations match, and install any new
6687 default parameters. We must tsubst the default parameters,
6688 of course. We only need the innermost template parameters
6689 because that is all that redeclare_class_template will look
6691 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
6692 > TMPL_ARGS_DEPTH (args))
6695 location_t saved_input_location;
6696 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
6697 args, tf_warning_or_error);
6699 saved_input_location = input_location;
6700 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
6701 redeclare_class_template (TREE_TYPE (tmpl), parms);
6702 input_location = saved_input_location;
6706 friend_type = TREE_TYPE (tmpl);
6710 /* The friend template has not already been declared. In this
6711 case, the instantiation of the template class will cause the
6712 injection of this template into the global scope. */
6713 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
6714 if (tmpl == error_mark_node)
6715 return error_mark_node;
6717 /* The new TMPL is not an instantiation of anything, so we
6718 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
6719 the new type because that is supposed to be the corresponding
6720 template decl, i.e., TMPL. */
6721 DECL_USE_TEMPLATE (tmpl) = 0;
6722 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
6723 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
6724 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
6725 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
6727 /* Inject this template into the global scope. */
6728 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
6733 if (TREE_CODE (context) == NAMESPACE_DECL)
6734 pop_nested_namespace (context);
6736 pop_nested_class ();
6742 /* Returns zero if TYPE cannot be completed later due to circularity.
6743 Otherwise returns one. */
6746 can_complete_type_without_circularity (tree type)
6748 if (type == NULL_TREE || type == error_mark_node)
6750 else if (COMPLETE_TYPE_P (type))
6752 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
6753 return can_complete_type_without_circularity (TREE_TYPE (type));
6754 else if (CLASS_TYPE_P (type)
6755 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
6761 /* Apply any attributes which had to be deferred until instantiation
6762 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
6763 ARGS, COMPLAIN, IN_DECL are as tsubst. */
6766 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
6767 tree args, tsubst_flags_t complain, tree in_decl)
6769 tree last_dep = NULL_TREE;
6773 for (t = attributes; t; t = TREE_CHAIN (t))
6774 if (ATTR_IS_DEPENDENT (t))
6777 attributes = copy_list (attributes);
6781 if (DECL_P (*decl_p))
6783 if (TREE_TYPE (*decl_p) == error_mark_node)
6785 p = &DECL_ATTRIBUTES (*decl_p);
6788 p = &TYPE_ATTRIBUTES (*decl_p);
6792 tree late_attrs = NULL_TREE;
6793 tree *q = &late_attrs;
6795 for (*p = attributes; *p; )
6798 if (ATTR_IS_DEPENDENT (t))
6800 *p = TREE_CHAIN (t);
6801 TREE_CHAIN (t) = NULL_TREE;
6802 /* If the first attribute argument is an identifier, don't
6803 pass it through tsubst. Attributes like mode, format,
6804 cleanup and several target specific attributes expect it
6807 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
6808 && TREE_VALUE (TREE_VALUE (t))
6809 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
6810 == IDENTIFIER_NODE))
6813 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
6815 /*integral_constant_expression_p=*/false);
6816 if (chain != TREE_CHAIN (TREE_VALUE (t)))
6818 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
6823 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
6824 /*integral_constant_expression_p=*/false);
6826 q = &TREE_CHAIN (t);
6829 p = &TREE_CHAIN (t);
6832 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
6837 instantiate_class_template (tree type)
6839 tree templ, args, pattern, t, member;
6844 if (type == error_mark_node)
6845 return error_mark_node;
6847 if (TYPE_BEING_DEFINED (type)
6848 || COMPLETE_TYPE_P (type)
6849 || dependent_type_p (type))
6852 /* Figure out which template is being instantiated. */
6853 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
6854 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
6856 /* Determine what specialization of the original template to
6858 t = most_specialized_class (type, templ);
6859 if (t == error_mark_node)
6861 TYPE_BEING_DEFINED (type) = 1;
6862 return error_mark_node;
6866 /* This TYPE is actually an instantiation of a partial
6867 specialization. We replace the innermost set of ARGS with
6868 the arguments appropriate for substitution. For example,
6871 template <class T> struct S {};
6872 template <class T> struct S<T*> {};
6874 and supposing that we are instantiating S<int*>, ARGS will
6875 presently be {int*} -- but we need {int}. */
6876 pattern = TREE_TYPE (t);
6877 args = TREE_PURPOSE (t);
6881 pattern = TREE_TYPE (templ);
6882 args = CLASSTYPE_TI_ARGS (type);
6885 /* If the template we're instantiating is incomplete, then clearly
6886 there's nothing we can do. */
6887 if (!COMPLETE_TYPE_P (pattern))
6890 /* If we've recursively instantiated too many templates, stop. */
6891 if (! push_tinst_level (type))
6894 /* Now we're really doing the instantiation. Mark the type as in
6895 the process of being defined. */
6896 TYPE_BEING_DEFINED (type) = 1;
6898 /* We may be in the middle of deferred access check. Disable
6900 push_deferring_access_checks (dk_no_deferred);
6902 push_to_top_level ();
6904 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
6906 /* Set the input location to the template definition. This is needed
6907 if tsubsting causes an error. */
6908 typedecl = TYPE_MAIN_DECL (type);
6909 input_location = DECL_SOURCE_LOCATION (typedecl);
6911 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
6912 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
6913 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
6914 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
6915 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
6916 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
6917 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
6918 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
6919 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
6920 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
6921 TYPE_PACKED (type) = TYPE_PACKED (pattern);
6922 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
6923 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
6924 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
6925 if (ANON_AGGR_TYPE_P (pattern))
6926 SET_ANON_AGGR_TYPE_P (type);
6927 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
6929 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
6930 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
6933 pbinfo = TYPE_BINFO (pattern);
6935 /* We should never instantiate a nested class before its enclosing
6936 class; we need to look up the nested class by name before we can
6937 instantiate it, and that lookup should instantiate the enclosing
6939 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
6940 || COMPLETE_TYPE_P (TYPE_CONTEXT (type))
6941 || TYPE_BEING_DEFINED (TYPE_CONTEXT (type)));
6943 base_list = NULL_TREE;
6944 if (BINFO_N_BASE_BINFOS (pbinfo))
6947 tree context = TYPE_CONTEXT (type);
6951 /* We must enter the scope containing the type, as that is where
6952 the accessibility of types named in dependent bases are
6954 pushed_scope = push_scope (context ? context : global_namespace);
6956 /* Substitute into each of the bases to determine the actual
6958 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
6961 tree access = BINFO_BASE_ACCESS (pbinfo, i);
6962 tree expanded_bases = NULL_TREE;
6965 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
6968 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
6969 args, tf_error, NULL_TREE);
6970 if (expanded_bases == error_mark_node)
6973 len = TREE_VEC_LENGTH (expanded_bases);
6976 for (idx = 0; idx < len; idx++)
6979 /* Extract the already-expanded base class. */
6980 base = TREE_VEC_ELT (expanded_bases, idx);
6982 /* Substitute to figure out the base class. */
6983 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
6986 if (base == error_mark_node)
6989 base_list = tree_cons (access, base, base_list);
6990 if (BINFO_VIRTUAL_P (pbase_binfo))
6991 TREE_TYPE (base_list) = integer_type_node;
6995 /* The list is now in reverse order; correct that. */
6996 base_list = nreverse (base_list);
6999 pop_scope (pushed_scope);
7001 /* Now call xref_basetypes to set up all the base-class
7003 xref_basetypes (type, base_list);
7005 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
7006 (int) ATTR_FLAG_TYPE_IN_PLACE,
7007 args, tf_error, NULL_TREE);
7009 /* Now that our base classes are set up, enter the scope of the
7010 class, so that name lookups into base classes, etc. will work
7011 correctly. This is precisely analogous to what we do in
7012 begin_class_definition when defining an ordinary non-template
7013 class, except we also need to push the enclosing classes. */
7014 push_nested_class (type);
7016 /* Now members are processed in the order of declaration. */
7017 for (member = CLASSTYPE_DECL_LIST (pattern);
7018 member; member = TREE_CHAIN (member))
7020 tree t = TREE_VALUE (member);
7022 if (TREE_PURPOSE (member))
7026 /* Build new CLASSTYPE_NESTED_UTDS. */
7029 bool class_template_p;
7031 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
7032 && TYPE_LANG_SPECIFIC (t)
7033 && CLASSTYPE_IS_TEMPLATE (t));
7034 /* If the member is a class template, then -- even after
7035 substitution -- there may be dependent types in the
7036 template argument list for the class. We increment
7037 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7038 that function will assume that no types are dependent
7039 when outside of a template. */
7040 if (class_template_p)
7041 ++processing_template_decl;
7042 newtag = tsubst (t, args, tf_error, NULL_TREE);
7043 if (class_template_p)
7044 --processing_template_decl;
7045 if (newtag == error_mark_node)
7048 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
7050 tree name = TYPE_IDENTIFIER (t);
7052 if (class_template_p)
7053 /* Unfortunately, lookup_template_class sets
7054 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7055 instantiation (i.e., for the type of a member
7056 template class nested within a template class.)
7057 This behavior is required for
7058 maybe_process_partial_specialization to work
7059 correctly, but is not accurate in this case;
7060 the TAG is not an instantiation of anything.
7061 (The corresponding TEMPLATE_DECL is an
7062 instantiation, but the TYPE is not.) */
7063 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
7065 /* Now, we call pushtag to put this NEWTAG into the scope of
7066 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7067 pushtag calling push_template_decl. We don't have to do
7068 this for enums because it will already have been done in
7071 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
7072 pushtag (name, newtag, /*tag_scope=*/ts_current);
7075 else if (TREE_CODE (t) == FUNCTION_DECL
7076 || DECL_FUNCTION_TEMPLATE_P (t))
7078 /* Build new TYPE_METHODS. */
7081 if (TREE_CODE (t) == TEMPLATE_DECL)
7082 ++processing_template_decl;
7083 r = tsubst (t, args, tf_error, NULL_TREE);
7084 if (TREE_CODE (t) == TEMPLATE_DECL)
7085 --processing_template_decl;
7086 set_current_access_from_decl (r);
7087 finish_member_declaration (r);
7091 /* Build new TYPE_FIELDS. */
7092 if (TREE_CODE (t) == STATIC_ASSERT)
7095 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
7096 tf_warning_or_error, NULL_TREE,
7097 /*integral_constant_expression_p=*/true);
7098 finish_static_assert (condition,
7099 STATIC_ASSERT_MESSAGE (t),
7100 STATIC_ASSERT_SOURCE_LOCATION (t),
7103 else if (TREE_CODE (t) != CONST_DECL)
7107 /* The file and line for this declaration, to
7108 assist in error message reporting. Since we
7109 called push_tinst_level above, we don't need to
7111 input_location = DECL_SOURCE_LOCATION (t);
7113 if (TREE_CODE (t) == TEMPLATE_DECL)
7114 ++processing_template_decl;
7115 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
7116 if (TREE_CODE (t) == TEMPLATE_DECL)
7117 --processing_template_decl;
7118 if (TREE_CODE (r) == VAR_DECL)
7122 [t]he initialization (and any associated
7123 side-effects) of a static data member does
7124 not occur unless the static data member is
7125 itself used in a way that requires the
7126 definition of the static data member to
7129 Therefore, we do not substitute into the
7130 initialized for the static data member here. */
7131 finish_static_data_member_decl
7134 /*init_const_expr_p=*/false,
7135 /*asmspec_tree=*/NULL_TREE,
7137 if (DECL_INITIALIZED_IN_CLASS_P (r))
7138 check_static_variable_definition (r, TREE_TYPE (r));
7140 else if (TREE_CODE (r) == FIELD_DECL)
7142 /* Determine whether R has a valid type and can be
7143 completed later. If R is invalid, then it is
7144 replaced by error_mark_node so that it will not be
7145 added to TYPE_FIELDS. */
7146 tree rtype = TREE_TYPE (r);
7147 if (can_complete_type_without_circularity (rtype))
7148 complete_type (rtype);
7150 if (!COMPLETE_TYPE_P (rtype))
7152 cxx_incomplete_type_error (r, rtype);
7153 r = error_mark_node;
7157 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7158 such a thing will already have been added to the field
7159 list by tsubst_enum in finish_member_declaration in the
7160 CLASSTYPE_NESTED_UTDS case above. */
7161 if (!(TREE_CODE (r) == TYPE_DECL
7162 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
7163 && DECL_ARTIFICIAL (r)))
7165 set_current_access_from_decl (r);
7166 finish_member_declaration (r);
7173 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
7175 /* Build new CLASSTYPE_FRIEND_CLASSES. */
7177 tree friend_type = t;
7178 bool adjust_processing_template_decl = false;
7180 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7182 /* template <class T> friend class C; */
7183 friend_type = tsubst_friend_class (friend_type, args);
7184 adjust_processing_template_decl = true;
7186 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
7188 /* template <class T> friend class C::D; */
7189 friend_type = tsubst (friend_type, args,
7190 tf_warning_or_error, NULL_TREE);
7191 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7192 friend_type = TREE_TYPE (friend_type);
7193 adjust_processing_template_decl = true;
7195 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
7197 /* This could be either
7201 when dependent_type_p is false or
7203 template <class U> friend class T::C;
7206 friend_type = tsubst (friend_type, args,
7207 tf_warning_or_error, NULL_TREE);
7208 /* Bump processing_template_decl for correct
7209 dependent_type_p calculation. */
7210 ++processing_template_decl;
7211 if (dependent_type_p (friend_type))
7212 adjust_processing_template_decl = true;
7213 --processing_template_decl;
7215 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
7216 && hidden_name_p (TYPE_NAME (friend_type)))
7220 where C hasn't been declared yet. Let's lookup name
7221 from namespace scope directly, bypassing any name that
7222 come from dependent base class. */
7223 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
7225 /* The call to xref_tag_from_type does injection for friend
7227 push_nested_namespace (ns);
7229 xref_tag_from_type (friend_type, NULL_TREE,
7230 /*tag_scope=*/ts_current);
7231 pop_nested_namespace (ns);
7233 else if (uses_template_parms (friend_type))
7234 /* friend class C<T>; */
7235 friend_type = tsubst (friend_type, args,
7236 tf_warning_or_error, NULL_TREE);
7241 where C is already declared or
7243 friend class C<int>;
7245 We don't have to do anything in these cases. */
7247 if (adjust_processing_template_decl)
7248 /* Trick make_friend_class into realizing that the friend
7249 we're adding is a template, not an ordinary class. It's
7250 important that we use make_friend_class since it will
7251 perform some error-checking and output cross-reference
7253 ++processing_template_decl;
7255 if (friend_type != error_mark_node)
7256 make_friend_class (type, friend_type, /*complain=*/false);
7258 if (adjust_processing_template_decl)
7259 --processing_template_decl;
7263 /* Build new DECL_FRIENDLIST. */
7266 /* The file and line for this declaration, to
7267 assist in error message reporting. Since we
7268 called push_tinst_level above, we don't need to
7270 input_location = DECL_SOURCE_LOCATION (t);
7272 if (TREE_CODE (t) == TEMPLATE_DECL)
7274 ++processing_template_decl;
7275 push_deferring_access_checks (dk_no_check);
7278 r = tsubst_friend_function (t, args);
7279 add_friend (type, r, /*complain=*/false);
7280 if (TREE_CODE (t) == TEMPLATE_DECL)
7282 pop_deferring_access_checks ();
7283 --processing_template_decl;
7289 /* Set the file and line number information to whatever is given for
7290 the class itself. This puts error messages involving generated
7291 implicit functions at a predictable point, and the same point
7292 that would be used for non-template classes. */
7293 input_location = DECL_SOURCE_LOCATION (typedecl);
7295 unreverse_member_declarations (type);
7296 finish_struct_1 (type);
7297 TYPE_BEING_DEFINED (type) = 0;
7299 /* Now that the class is complete, instantiate default arguments for
7300 any member functions. We don't do this earlier because the
7301 default arguments may reference members of the class. */
7302 if (!PRIMARY_TEMPLATE_P (templ))
7303 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
7304 if (TREE_CODE (t) == FUNCTION_DECL
7305 /* Implicitly generated member functions will not have template
7306 information; they are not instantiations, but instead are
7307 created "fresh" for each instantiation. */
7308 && DECL_TEMPLATE_INFO (t))
7309 tsubst_default_arguments (t);
7311 pop_nested_class ();
7312 pop_from_top_level ();
7313 pop_deferring_access_checks ();
7316 /* The vtable for a template class can be emitted in any translation
7317 unit in which the class is instantiated. When there is no key
7318 method, however, finish_struct_1 will already have added TYPE to
7319 the keyed_classes list. */
7320 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
7321 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
7327 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7333 else if (TYPE_P (t))
7334 r = tsubst (t, args, complain, in_decl);
7337 r = tsubst_expr (t, args, complain, in_decl,
7338 /*integral_constant_expression_p=*/true);
7339 r = fold_non_dependent_expr (r);
7344 /* Substitute ARGS into T, which is an pack expansion
7345 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
7346 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
7347 (if only a partial substitution could be performed) or
7348 ERROR_MARK_NODE if there was an error. */
7350 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
7354 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
7355 tree first_arg_pack; int i, len = -1;
7359 gcc_assert (PACK_EXPANSION_P (t));
7360 pattern = PACK_EXPANSION_PATTERN (t);
7362 /* Determine the argument packs that will instantiate the parameter
7363 packs used in the expansion expression. While we're at it,
7364 compute the number of arguments to be expanded and make sure it
7366 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
7367 pack = TREE_CHAIN (pack))
7369 tree parm_pack = TREE_VALUE (pack);
7370 tree arg_pack = NULL_TREE;
7371 tree orig_arg = NULL_TREE;
7373 if (TREE_CODE (parm_pack) == PARM_DECL)
7374 arg_pack = retrieve_local_specialization (parm_pack);
7377 int level, idx, levels;
7378 template_parm_level_and_index (parm_pack, &level, &idx);
7380 levels = TMPL_ARGS_DEPTH (args);
7381 if (level <= levels)
7382 arg_pack = TMPL_ARG (args, level, idx);
7385 orig_arg = arg_pack;
7386 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
7387 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
7389 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
7390 /* This can only happen if we forget to expand an argument
7391 pack somewhere else. Just return an error, silently. */
7393 result = make_tree_vec (1);
7394 TREE_VEC_ELT (result, 0) = error_mark_node;
7399 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
7400 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
7402 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
7403 tree pattern = PACK_EXPANSION_PATTERN (expansion);
7404 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
7405 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
7406 /* The argument pack that the parameter maps to is just an
7407 expansion of the parameter itself, such as one would
7408 find in the implicit typedef of a class inside the
7409 class itself. Consider this parameter "unsubstituted",
7410 so that we will maintain the outer pack expansion. */
7411 arg_pack = NULL_TREE;
7417 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
7419 /* It's all-or-nothing with incomplete argument packs. */
7420 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
7421 return error_mark_node;
7423 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
7429 first_arg_pack = arg_pack;
7431 else if (len != my_len)
7433 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
7434 error ("mismatched argument pack lengths while expanding "
7438 error ("mismatched argument pack lengths while expanding "
7441 return error_mark_node;
7444 /* Keep track of the parameter packs and their corresponding
7446 packs = tree_cons (parm_pack, arg_pack, packs);
7447 TREE_TYPE (packs) = orig_arg;
7450 /* We can't substitute for this parameter pack. */
7451 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
7453 unsubstituted_packs);
7456 /* We cannot expand this expansion expression, because we don't have
7457 all of the argument packs we need. Substitute into the pattern
7458 and return a PACK_EXPANSION_*. The caller will need to deal with
7460 if (unsubstituted_packs)
7461 return make_pack_expansion (tsubst (pattern, args, complain,
7464 /* We could not find any argument packs that work. */
7466 return error_mark_node;
7468 /* For each argument in each argument pack, substitute into the
7470 result = make_tree_vec (len + incomplete);
7471 for (i = 0; i < len + incomplete; ++i)
7473 /* For parameter pack, change the substitution of the parameter
7474 pack to the ith argument in its argument pack, then expand
7476 for (pack = packs; pack; pack = TREE_CHAIN (pack))
7478 tree parm = TREE_PURPOSE (pack);
7480 if (TREE_CODE (parm) == PARM_DECL)
7482 /* Select the Ith argument from the pack. */
7483 tree arg = make_node (ARGUMENT_PACK_SELECT);
7484 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
7485 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
7487 register_local_specialization (arg, parm);
7493 template_parm_level_and_index (parm, &level, &idx);
7497 /* Select the Ith argument from the pack. */
7498 value = make_node (ARGUMENT_PACK_SELECT);
7499 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
7500 ARGUMENT_PACK_SELECT_INDEX (value) = i;
7503 /* Update the corresponding argument. */
7504 TMPL_ARG (args, level, idx) = value;
7508 /* Substitute into the PATTERN with the altered arguments. */
7509 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
7510 TREE_VEC_ELT (result, i) =
7511 tsubst_expr (pattern, args, complain, in_decl,
7512 /*integral_constant_expression_p=*/false);
7514 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
7517 /* When we have incomplete argument packs, the last "expanded"
7518 result is itself a pack expansion, which allows us
7519 to deduce more arguments. */
7520 TREE_VEC_ELT (result, i) =
7521 make_pack_expansion (TREE_VEC_ELT (result, i));
7523 if (TREE_VEC_ELT (result, i) == error_mark_node)
7525 result = error_mark_node;
7530 /* Update ARGS to restore the substitution from parameter packs to
7531 their argument packs. */
7532 for (pack = packs; pack; pack = TREE_CHAIN (pack))
7534 tree parm = TREE_PURPOSE (pack);
7536 if (TREE_CODE (parm) == PARM_DECL)
7537 register_local_specialization (TREE_TYPE (pack), parm);
7541 template_parm_level_and_index (parm, &level, &idx);
7543 /* Update the corresponding argument. */
7544 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
7545 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
7548 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
7555 /* Substitute ARGS into the vector or list of template arguments T. */
7558 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7561 int len = TREE_VEC_LENGTH (t);
7562 int need_new = 0, i, expanded_len_adjust = 0, out;
7563 tree *elts = (tree *) alloca (len * sizeof (tree));
7565 for (i = 0; i < len; i++)
7567 tree orig_arg = TREE_VEC_ELT (t, i);
7570 if (TREE_CODE (orig_arg) == TREE_VEC)
7571 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
7572 else if (PACK_EXPANSION_P (orig_arg))
7574 /* Substitute into an expansion expression. */
7575 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
7577 if (TREE_CODE (new_arg) == TREE_VEC)
7578 /* Add to the expanded length adjustment the number of
7579 expanded arguments. We subtract one from this
7580 measurement, because the argument pack expression
7581 itself is already counted as 1 in
7582 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
7583 the argument pack is empty. */
7584 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
7586 else if (ARGUMENT_PACK_P (orig_arg))
7588 /* Substitute into each of the arguments. */
7589 new_arg = make_node (TREE_CODE (orig_arg));
7591 SET_ARGUMENT_PACK_ARGS (
7593 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
7594 args, complain, in_decl));
7596 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
7597 new_arg = error_mark_node;
7599 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
7600 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
7602 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
7604 if (TREE_TYPE (new_arg) == error_mark_node)
7605 new_arg = error_mark_node;
7609 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
7611 if (new_arg == error_mark_node)
7612 return error_mark_node;
7615 if (new_arg != orig_arg)
7622 /* Make space for the expanded arguments coming from template
7624 t = make_tree_vec (len + expanded_len_adjust);
7625 for (i = 0, out = 0; i < len; i++)
7627 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
7628 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
7629 && TREE_CODE (elts[i]) == TREE_VEC)
7633 /* Now expand the template argument pack "in place". */
7634 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
7635 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
7639 TREE_VEC_ELT (t, out) = elts[i];
7647 /* Return the result of substituting ARGS into the template parameters
7648 given by PARMS. If there are m levels of ARGS and m + n levels of
7649 PARMS, then the result will contain n levels of PARMS. For
7650 example, if PARMS is `template <class T> template <class U>
7651 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
7652 result will be `template <int*, double, class V>'. */
7655 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
7660 /* When substituting into a template, we must set
7661 PROCESSING_TEMPLATE_DECL as the template parameters may be
7662 dependent if they are based on one-another, and the dependency
7663 predicates are short-circuit outside of templates. */
7664 ++processing_template_decl;
7666 for (new_parms = &r;
7667 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
7668 new_parms = &(TREE_CHAIN (*new_parms)),
7669 parms = TREE_CHAIN (parms))
7672 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
7675 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
7681 if (parms == error_mark_node)
7684 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
7686 if (tuple == error_mark_node)
7689 default_value = TREE_PURPOSE (tuple);
7690 parm_decl = TREE_VALUE (tuple);
7692 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
7693 if (TREE_CODE (parm_decl) == PARM_DECL
7694 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
7695 parm_decl = error_mark_node;
7696 default_value = tsubst_template_arg (default_value, args,
7697 complain, NULL_TREE);
7699 tuple = build_tree_list (default_value, parm_decl);
7700 TREE_VEC_ELT (new_vec, i) = tuple;
7704 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
7705 - TMPL_ARGS_DEPTH (args)),
7706 new_vec, NULL_TREE);
7709 --processing_template_decl;
7714 /* Substitute the ARGS into the indicated aggregate (or enumeration)
7715 type T. If T is not an aggregate or enumeration type, it is
7716 handled as if by tsubst. IN_DECL is as for tsubst. If
7717 ENTERING_SCOPE is nonzero, T is the context for a template which
7718 we are presently tsubst'ing. Return the substituted value. */
7721 tsubst_aggr_type (tree t,
7723 tsubst_flags_t complain,
7730 switch (TREE_CODE (t))
7733 if (TYPE_PTRMEMFUNC_P (t))
7734 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
7736 /* Else fall through. */
7739 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
7744 bool saved_skip_evaluation;
7746 /* In "sizeof(X<I>)" we need to evaluate "I". */
7747 saved_skip_evaluation = skip_evaluation;
7748 skip_evaluation = false;
7750 /* First, determine the context for the type we are looking
7752 context = TYPE_CONTEXT (t);
7755 context = tsubst_aggr_type (context, args, complain,
7756 in_decl, /*entering_scope=*/1);
7757 /* If context is a nested class inside a class template,
7758 it may still need to be instantiated (c++/33959). */
7759 if (TYPE_P (context))
7760 context = complete_type (context);
7763 /* Then, figure out what arguments are appropriate for the
7764 type we are trying to find. For example, given:
7766 template <class T> struct S;
7767 template <class T, class U> void f(T, U) { S<U> su; }
7769 and supposing that we are instantiating f<int, double>,
7770 then our ARGS will be {int, double}, but, when looking up
7771 S we only want {double}. */
7772 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
7774 if (argvec == error_mark_node)
7775 r = error_mark_node;
7778 r = lookup_template_class (t, argvec, in_decl, context,
7779 entering_scope, complain);
7780 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
7783 skip_evaluation = saved_skip_evaluation;
7788 /* This is not a template type, so there's nothing to do. */
7792 return tsubst (t, args, complain, in_decl);
7796 /* Substitute into the default argument ARG (a default argument for
7797 FN), which has the indicated TYPE. */
7800 tsubst_default_argument (tree fn, tree type, tree arg)
7802 tree saved_class_ptr = NULL_TREE;
7803 tree saved_class_ref = NULL_TREE;
7805 /* This default argument came from a template. Instantiate the
7806 default argument here, not in tsubst. In the case of
7815 we must be careful to do name lookup in the scope of S<T>,
7816 rather than in the current class. */
7817 push_access_scope (fn);
7818 /* The "this" pointer is not valid in a default argument. */
7821 saved_class_ptr = current_class_ptr;
7822 cp_function_chain->x_current_class_ptr = NULL_TREE;
7823 saved_class_ref = current_class_ref;
7824 cp_function_chain->x_current_class_ref = NULL_TREE;
7827 push_deferring_access_checks(dk_no_deferred);
7828 /* The default argument expression may cause implicitly defined
7829 member functions to be synthesized, which will result in garbage
7830 collection. We must treat this situation as if we were within
7831 the body of function so as to avoid collecting live data on the
7834 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
7835 tf_warning_or_error, NULL_TREE,
7836 /*integral_constant_expression_p=*/false);
7838 pop_deferring_access_checks();
7840 /* Restore the "this" pointer. */
7843 cp_function_chain->x_current_class_ptr = saved_class_ptr;
7844 cp_function_chain->x_current_class_ref = saved_class_ref;
7847 pop_access_scope (fn);
7849 /* Make sure the default argument is reasonable. */
7850 arg = check_default_argument (type, arg);
7855 /* Substitute into all the default arguments for FN. */
7858 tsubst_default_arguments (tree fn)
7863 tmpl_args = DECL_TI_ARGS (fn);
7865 /* If this function is not yet instantiated, we certainly don't need
7866 its default arguments. */
7867 if (uses_template_parms (tmpl_args))
7870 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
7872 arg = TREE_CHAIN (arg))
7873 if (TREE_PURPOSE (arg))
7874 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
7876 TREE_PURPOSE (arg));
7879 /* Substitute the ARGS into the T, which is a _DECL. Return the
7880 result of the substitution. Issue error and warning messages under
7881 control of COMPLAIN. */
7884 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
7886 location_t saved_loc;
7890 /* Set the filename and linenumber to improve error-reporting. */
7891 saved_loc = input_location;
7892 input_location = DECL_SOURCE_LOCATION (t);
7894 switch (TREE_CODE (t))
7898 /* We can get here when processing a member function template,
7899 member class template, and template template parameter of
7900 a template class. */
7901 tree decl = DECL_TEMPLATE_RESULT (t);
7906 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
7908 /* Template template parameter is treated here. */
7909 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
7910 if (new_type == error_mark_node)
7911 return error_mark_node;
7914 TREE_CHAIN (r) = NULL_TREE;
7915 TREE_TYPE (r) = new_type;
7916 DECL_TEMPLATE_RESULT (r)
7917 = build_decl (TYPE_DECL, DECL_NAME (decl), new_type);
7918 DECL_TEMPLATE_PARMS (r)
7919 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
7921 TYPE_NAME (new_type) = r;
7925 /* We might already have an instance of this template.
7926 The ARGS are for the surrounding class type, so the
7927 full args contain the tsubst'd args for the context,
7928 plus the innermost args from the template decl. */
7929 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
7930 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
7931 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
7932 /* Because this is a template, the arguments will still be
7933 dependent, even after substitution. If
7934 PROCESSING_TEMPLATE_DECL is not set, the dependency
7935 predicates will short-circuit. */
7936 ++processing_template_decl;
7937 full_args = tsubst_template_args (tmpl_args, args,
7939 --processing_template_decl;
7940 if (full_args == error_mark_node)
7941 return error_mark_node;
7943 /* tsubst_template_args doesn't copy the vector if
7944 nothing changed. But, *something* should have
7946 gcc_assert (full_args != tmpl_args);
7948 spec = retrieve_specialization (t, full_args,
7949 /*class_specializations_p=*/true);
7950 if (spec != NULL_TREE)
7956 /* Make a new template decl. It will be similar to the
7957 original, but will record the current template arguments.
7958 We also create a new function declaration, which is just
7959 like the old one, but points to this new template, rather
7960 than the old one. */
7962 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
7963 TREE_CHAIN (r) = NULL_TREE;
7965 DECL_TEMPLATE_INFO (r) = build_tree_list (t, args);
7967 if (TREE_CODE (decl) == TYPE_DECL)
7970 ++processing_template_decl;
7971 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
7972 --processing_template_decl;
7973 if (new_type == error_mark_node)
7974 return error_mark_node;
7976 TREE_TYPE (r) = new_type;
7977 CLASSTYPE_TI_TEMPLATE (new_type) = r;
7978 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
7979 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
7980 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
7985 ++processing_template_decl;
7986 new_decl = tsubst (decl, args, complain, in_decl);
7987 --processing_template_decl;
7988 if (new_decl == error_mark_node)
7989 return error_mark_node;
7991 DECL_TEMPLATE_RESULT (r) = new_decl;
7992 DECL_TI_TEMPLATE (new_decl) = r;
7993 TREE_TYPE (r) = TREE_TYPE (new_decl);
7994 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
7995 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
7998 SET_DECL_IMPLICIT_INSTANTIATION (r);
7999 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
8000 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
8002 /* The template parameters for this new template are all the
8003 template parameters for the old template, except the
8004 outermost level of parameters. */
8005 DECL_TEMPLATE_PARMS (r)
8006 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8009 if (PRIMARY_TEMPLATE_P (t))
8010 DECL_PRIMARY_TEMPLATE (r) = r;
8012 if (TREE_CODE (decl) != TYPE_DECL)
8013 /* Record this non-type partial instantiation. */
8014 register_specialization (r, t,
8015 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
8023 tree argvec = NULL_TREE;
8031 /* Nobody should be tsubst'ing into non-template functions. */
8032 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
8034 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
8039 /* If T is not dependent, just return it. We have to
8040 increment PROCESSING_TEMPLATE_DECL because
8041 value_dependent_expression_p assumes that nothing is
8042 dependent when PROCESSING_TEMPLATE_DECL is zero. */
8043 ++processing_template_decl;
8044 dependent_p = value_dependent_expression_p (t);
8045 --processing_template_decl;
8049 /* Calculate the most general template of which R is a
8050 specialization, and the complete set of arguments used to
8052 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
8053 argvec = tsubst_template_args (DECL_TI_ARGS
8054 (DECL_TEMPLATE_RESULT (gen_tmpl)),
8055 args, complain, in_decl);
8057 /* Check to see if we already have this specialization. */
8058 spec = retrieve_specialization (gen_tmpl, argvec,
8059 /*class_specializations_p=*/false);
8067 /* We can see more levels of arguments than parameters if
8068 there was a specialization of a member template, like
8071 template <class T> struct S { template <class U> void f(); }
8072 template <> template <class U> void S<int>::f(U);
8074 Here, we'll be substituting into the specialization,
8075 because that's where we can find the code we actually
8076 want to generate, but we'll have enough arguments for
8077 the most general template.
8079 We also deal with the peculiar case:
8081 template <class T> struct S {
8082 template <class U> friend void f();
8084 template <class U> void f() {}
8086 template void f<double>();
8088 Here, the ARGS for the instantiation of will be {int,
8089 double}. But, we only need as many ARGS as there are
8090 levels of template parameters in CODE_PATTERN. We are
8091 careful not to get fooled into reducing the ARGS in
8094 template <class T> struct S { template <class U> void f(U); }
8095 template <class T> template <> void S<T>::f(int) {}
8097 which we can spot because the pattern will be a
8098 specialization in this case. */
8099 args_depth = TMPL_ARGS_DEPTH (args);
8101 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
8102 if (args_depth > parms_depth
8103 && !DECL_TEMPLATE_SPECIALIZATION (t))
8104 args = get_innermost_template_args (args, parms_depth);
8108 /* This special case arises when we have something like this:
8110 template <class T> struct S {
8111 friend void f<int>(int, double);
8114 Here, the DECL_TI_TEMPLATE for the friend declaration
8115 will be an IDENTIFIER_NODE. We are being called from
8116 tsubst_friend_function, and we want only to create a
8117 new decl (R) with appropriate types so that we can call
8118 determine_specialization. */
8119 gen_tmpl = NULL_TREE;
8122 if (DECL_CLASS_SCOPE_P (t))
8124 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
8128 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
8129 complain, t, /*entering_scope=*/1);
8134 ctx = DECL_CONTEXT (t);
8136 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8137 if (type == error_mark_node)
8138 return error_mark_node;
8140 /* We do NOT check for matching decls pushed separately at this
8141 point, as they may not represent instantiations of this
8142 template, and in any case are considered separate under the
8145 DECL_USE_TEMPLATE (r) = 0;
8146 TREE_TYPE (r) = type;
8147 /* Clear out the mangled name and RTL for the instantiation. */
8148 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8149 SET_DECL_RTL (r, NULL_RTX);
8150 /* Leave DECL_INITIAL set on deleted instantiations. */
8151 if (!DECL_DELETED_FN (r))
8152 DECL_INITIAL (r) = NULL_TREE;
8153 DECL_CONTEXT (r) = ctx;
8155 if (member && DECL_CONV_FN_P (r))
8156 /* Type-conversion operator. Reconstruct the name, in
8157 case it's the name of one of the template's parameters. */
8158 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
8160 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
8162 DECL_RESULT (r) = NULL_TREE;
8164 TREE_STATIC (r) = 0;
8165 TREE_PUBLIC (r) = TREE_PUBLIC (t);
8166 DECL_EXTERNAL (r) = 1;
8167 /* If this is an instantiation of a function with internal
8168 linkage, we already know what object file linkage will be
8169 assigned to the instantiation. */
8170 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
8171 DECL_DEFER_OUTPUT (r) = 0;
8172 TREE_CHAIN (r) = NULL_TREE;
8173 DECL_PENDING_INLINE_INFO (r) = 0;
8174 DECL_PENDING_INLINE_P (r) = 0;
8175 DECL_SAVED_TREE (r) = NULL_TREE;
8177 if (DECL_CLONED_FUNCTION (r))
8179 DECL_CLONED_FUNCTION (r) = tsubst (DECL_CLONED_FUNCTION (t),
8181 TREE_CHAIN (r) = TREE_CHAIN (DECL_CLONED_FUNCTION (r));
8182 TREE_CHAIN (DECL_CLONED_FUNCTION (r)) = r;
8185 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
8186 this in the special friend case mentioned above where
8187 GEN_TMPL is NULL. */
8190 DECL_TEMPLATE_INFO (r)
8191 = tree_cons (gen_tmpl, argvec, NULL_TREE);
8192 SET_DECL_IMPLICIT_INSTANTIATION (r);
8193 register_specialization (r, gen_tmpl, argvec, false);
8195 /* We're not supposed to instantiate default arguments
8196 until they are called, for a template. But, for a
8199 template <class T> void f ()
8200 { extern void g(int i = T()); }
8202 we should do the substitution when the template is
8203 instantiated. We handle the member function case in
8204 instantiate_class_template since the default arguments
8205 might refer to other members of the class. */
8207 && !PRIMARY_TEMPLATE_P (gen_tmpl)
8208 && !uses_template_parms (argvec))
8209 tsubst_default_arguments (r);
8212 DECL_TEMPLATE_INFO (r) = NULL_TREE;
8214 /* Copy the list of befriending classes. */
8215 for (friends = &DECL_BEFRIENDING_CLASSES (r);
8217 friends = &TREE_CHAIN (*friends))
8219 *friends = copy_node (*friends);
8220 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
8225 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
8227 maybe_retrofit_in_chrg (r);
8228 if (DECL_CONSTRUCTOR_P (r))
8229 grok_ctor_properties (ctx, r);
8230 /* If this is an instantiation of a member template, clone it.
8231 If it isn't, that'll be handled by
8232 clone_constructors_and_destructors. */
8233 if (PRIMARY_TEMPLATE_P (gen_tmpl))
8234 clone_function_decl (r, /*update_method_vec_p=*/0);
8236 else if (IDENTIFIER_OPNAME_P (DECL_NAME (r))
8237 && !grok_op_properties (r, (complain & tf_error) != 0))
8238 return error_mark_node;
8240 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
8241 SET_DECL_FRIEND_CONTEXT (r,
8242 tsubst (DECL_FRIEND_CONTEXT (t),
8243 args, complain, in_decl));
8245 /* Possibly limit visibility based on template args. */
8246 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8247 if (DECL_VISIBILITY_SPECIFIED (t))
8249 DECL_VISIBILITY_SPECIFIED (r) = 0;
8251 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8253 determine_visibility (r);
8255 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8256 args, complain, in_decl);
8262 tree type = NULL_TREE;
8264 tree expanded_types = NULL_TREE;
8265 tree prev_r = NULL_TREE;
8266 tree first_r = NULL_TREE;
8268 if (FUNCTION_PARAMETER_PACK_P (t))
8270 /* If there is a local specialization that isn't a
8271 parameter pack, it means that we're doing a "simple"
8272 substitution from inside tsubst_pack_expansion. Just
8273 return the local specialization (which will be a single
8275 tree spec = retrieve_local_specialization (t);
8277 && TREE_CODE (spec) == PARM_DECL
8278 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
8281 /* Expand the TYPE_PACK_EXPANSION that provides the types for
8282 the parameters in this function parameter pack. */
8283 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
8285 if (TREE_CODE (expanded_types) == TREE_VEC)
8287 len = TREE_VEC_LENGTH (expanded_types);
8289 /* Zero-length parameter packs are boring. Just substitute
8292 return tsubst (TREE_CHAIN (t), args, complain,
8297 /* All we did was update the type. Make a note of that. */
8298 type = expanded_types;
8299 expanded_types = NULL_TREE;
8303 /* Loop through all of the parameter's we'll build. When T is
8304 a function parameter pack, LEN is the number of expanded
8305 types in EXPANDED_TYPES; otherwise, LEN is 1. */
8307 for (i = 0; i < len; ++i)
8311 if (DECL_TEMPLATE_PARM_P (t))
8312 SET_DECL_TEMPLATE_PARM_P (r);
8315 /* We're on the Ith parameter of the function parameter
8318 /* Get the Ith type. */
8319 type = TREE_VEC_ELT (expanded_types, i);
8322 /* Rename the parameter to include the index. */
8324 make_ith_pack_parameter_name (DECL_NAME (r), i);
8327 /* We're dealing with a normal parameter. */
8328 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8330 type = type_decays_to (type);
8331 TREE_TYPE (r) = type;
8332 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8334 if (DECL_INITIAL (r))
8336 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
8337 DECL_INITIAL (r) = TREE_TYPE (r);
8339 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
8343 DECL_CONTEXT (r) = NULL_TREE;
8345 if (!DECL_TEMPLATE_PARM_P (r))
8346 DECL_ARG_TYPE (r) = type_passed_as (type);
8348 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8349 args, complain, in_decl);
8351 /* Keep track of the first new parameter we
8352 generate. That's what will be returned to the
8357 /* Build a proper chain of parameters when substituting
8358 into a function parameter pack. */
8360 TREE_CHAIN (prev_r) = r;
8364 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
8365 complain, TREE_CHAIN (t));
8367 /* FIRST_R contains the start of the chain we've built. */
8377 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8378 if (type == error_mark_node)
8379 return error_mark_node;
8380 TREE_TYPE (r) = type;
8381 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8383 /* DECL_INITIAL gives the number of bits in a bit-field. */
8385 = tsubst_expr (DECL_INITIAL (t), args,
8387 /*integral_constant_expression_p=*/true);
8388 /* We don't have to set DECL_CONTEXT here; it is set by
8389 finish_member_declaration. */
8390 TREE_CHAIN (r) = NULL_TREE;
8391 if (VOID_TYPE_P (type))
8392 error ("instantiation of %q+D as type %qT", r, type);
8394 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8395 args, complain, in_decl);
8400 /* We reach here only for member using decls. */
8401 if (DECL_DEPENDENT_P (t))
8403 r = do_class_using_decl
8404 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
8405 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
8407 r = error_mark_node;
8412 TREE_CHAIN (r) = NULL_TREE;
8419 tree argvec = NULL_TREE;
8420 tree gen_tmpl = NULL_TREE;
8422 tree tmpl = NULL_TREE;
8424 tree type = NULL_TREE;
8427 if (TREE_CODE (t) == TYPE_DECL
8428 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
8430 /* If this is the canonical decl, we don't have to
8431 mess with instantiations, and often we can't (for
8432 typename, template type parms and such). Note that
8433 TYPE_NAME is not correct for the above test if
8434 we've copied the type for a typedef. */
8435 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8436 if (type == error_mark_node)
8437 return error_mark_node;
8438 r = TYPE_NAME (type);
8442 /* Check to see if we already have the specialization we
8445 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
8447 /* T is a static data member or namespace-scope entity.
8448 We have to substitute into namespace-scope variables
8449 (even though such entities are never templates) because
8452 template <class T> void f() { extern T t; }
8454 where the entity referenced is not known until
8455 instantiation time. */
8457 ctx = DECL_CONTEXT (t);
8458 if (DECL_CLASS_SCOPE_P (t))
8460 ctx = tsubst_aggr_type (ctx, args,
8462 in_decl, /*entering_scope=*/1);
8463 /* If CTX is unchanged, then T is in fact the
8464 specialization we want. That situation occurs when
8465 referencing a static data member within in its own
8466 class. We can use pointer equality, rather than
8467 same_type_p, because DECL_CONTEXT is always
8469 if (ctx == DECL_CONTEXT (t))
8475 tmpl = DECL_TI_TEMPLATE (t);
8476 gen_tmpl = most_general_template (tmpl);
8477 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
8478 spec = (retrieve_specialization
8480 /*class_specializations_p=*/false));
8485 /* A local variable. */
8487 /* Subsequent calls to pushdecl will fill this in. */
8489 spec = retrieve_local_specialization (t);
8491 /* If we already have the specialization we need, there is
8492 nothing more to do. */
8499 /* Create a new node for the specialization we need. */
8501 if (type == NULL_TREE)
8502 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8503 if (TREE_CODE (r) == VAR_DECL)
8505 /* Even if the original location is out of scope, the
8506 newly substituted one is not. */
8507 DECL_DEAD_FOR_LOCAL (r) = 0;
8508 DECL_INITIALIZED_P (r) = 0;
8509 DECL_TEMPLATE_INSTANTIATED (r) = 0;
8510 if (type == error_mark_node)
8511 return error_mark_node;
8512 if (TREE_CODE (type) == FUNCTION_TYPE)
8514 /* It may seem that this case cannot occur, since:
8519 declares a function, not a variable. However:
8522 template <typename T> void g() { T t; }
8523 template void g<f>();
8525 is an attempt to declare a variable with function
8527 error ("variable %qD has function type",
8528 /* R is not yet sufficiently initialized, so we
8529 just use its name. */
8531 return error_mark_node;
8533 type = complete_type (type);
8534 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
8535 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
8536 type = check_var_type (DECL_NAME (r), type);
8538 if (DECL_HAS_VALUE_EXPR_P (t))
8540 tree ve = DECL_VALUE_EXPR (t);
8541 ve = tsubst_expr (ve, args, complain, in_decl,
8542 /*constant_expression_p=*/false);
8543 SET_DECL_VALUE_EXPR (r, ve);
8546 else if (DECL_SELF_REFERENCE_P (t))
8547 SET_DECL_SELF_REFERENCE_P (r);
8548 TREE_TYPE (r) = type;
8549 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8550 DECL_CONTEXT (r) = ctx;
8551 /* Clear out the mangled name and RTL for the instantiation. */
8552 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8553 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
8554 SET_DECL_RTL (r, NULL_RTX);
8555 /* The initializer must not be expanded until it is required;
8557 DECL_INITIAL (r) = NULL_TREE;
8558 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
8559 SET_DECL_RTL (r, NULL_RTX);
8560 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
8561 if (TREE_CODE (r) == VAR_DECL)
8563 /* Possibly limit visibility based on template args. */
8564 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8565 if (DECL_VISIBILITY_SPECIFIED (t))
8567 DECL_VISIBILITY_SPECIFIED (r) = 0;
8569 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8571 determine_visibility (r);
8573 /* Preserve a typedef that names a type. */
8574 else if (TREE_CODE (r) == TYPE_DECL
8575 && DECL_ORIGINAL_TYPE (t)
8576 && type != error_mark_node)
8578 DECL_ORIGINAL_TYPE (r) = tsubst (DECL_ORIGINAL_TYPE (t),
8579 args, complain, in_decl);
8580 TREE_TYPE (r) = type = build_variant_type_copy (type);
8581 TYPE_NAME (type) = r;
8586 /* A static data member declaration is always marked
8587 external when it is declared in-class, even if an
8588 initializer is present. We mimic the non-template
8590 DECL_EXTERNAL (r) = 1;
8592 register_specialization (r, gen_tmpl, argvec, false);
8593 DECL_TEMPLATE_INFO (r) = tree_cons (tmpl, argvec, NULL_TREE);
8594 SET_DECL_IMPLICIT_INSTANTIATION (r);
8597 register_local_specialization (r, t);
8599 TREE_CHAIN (r) = NULL_TREE;
8601 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
8602 (int) ATTR_FLAG_TYPE_IN_PLACE,
8603 args, complain, in_decl);
8612 /* Restore the file and line information. */
8613 input_location = saved_loc;
8618 /* Substitute into the ARG_TYPES of a function type. */
8621 tsubst_arg_types (tree arg_types,
8623 tsubst_flags_t complain,
8626 tree remaining_arg_types;
8627 tree type = NULL_TREE;
8629 tree expanded_args = NULL_TREE;
8632 if (!arg_types || arg_types == void_list_node)
8635 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
8636 args, complain, in_decl);
8637 if (remaining_arg_types == error_mark_node)
8638 return error_mark_node;
8640 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
8642 /* For a pack expansion, perform substitution on the
8643 entire expression. Later on, we'll handle the arguments
8645 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
8646 args, complain, in_decl);
8648 if (TREE_CODE (expanded_args) == TREE_VEC)
8649 /* So that we'll spin through the parameters, one by one. */
8650 i = TREE_VEC_LENGTH (expanded_args);
8653 /* We only partially substituted into the parameter
8654 pack. Our type is TYPE_PACK_EXPANSION. */
8655 type = expanded_args;
8656 expanded_args = NULL_TREE;
8664 type = TREE_VEC_ELT (expanded_args, i);
8666 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
8668 if (type == error_mark_node)
8669 return error_mark_node;
8670 if (VOID_TYPE_P (type))
8672 if (complain & tf_error)
8674 error ("invalid parameter type %qT", type);
8676 error ("in declaration %q+D", in_decl);
8678 return error_mark_node;
8681 /* Do array-to-pointer, function-to-pointer conversion, and ignore
8682 top-level qualifiers as required. */
8683 type = TYPE_MAIN_VARIANT (type_decays_to (type));
8685 /* We do not substitute into default arguments here. The standard
8686 mandates that they be instantiated only when needed, which is
8687 done in build_over_call. */
8688 default_arg = TREE_PURPOSE (arg_types);
8690 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
8692 /* We've instantiated a template before its default arguments
8693 have been parsed. This can happen for a nested template
8694 class, and is not an error unless we require the default
8695 argument in a call of this function. */
8696 remaining_arg_types =
8697 tree_cons (default_arg, type, remaining_arg_types);
8698 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
8699 remaining_arg_types);
8702 remaining_arg_types =
8703 hash_tree_cons (default_arg, type, remaining_arg_types);
8706 return remaining_arg_types;
8709 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
8710 *not* handle the exception-specification for FNTYPE, because the
8711 initial substitution of explicitly provided template parameters
8712 during argument deduction forbids substitution into the
8713 exception-specification:
8717 All references in the function type of the function template to the
8718 corresponding template parameters are replaced by the specified tem-
8719 plate argument values. If a substitution in a template parameter or
8720 in the function type of the function template results in an invalid
8721 type, type deduction fails. [Note: The equivalent substitution in
8722 exception specifications is done only when the function is instanti-
8723 ated, at which point a program is ill-formed if the substitution
8724 results in an invalid type.] */
8727 tsubst_function_type (tree t,
8729 tsubst_flags_t complain,
8736 /* The TYPE_CONTEXT is not used for function/method types. */
8737 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
8739 /* Substitute the return type. */
8740 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8741 if (return_type == error_mark_node)
8742 return error_mark_node;
8743 /* The standard does not presently indicate that creation of a
8744 function type with an invalid return type is a deduction failure.
8745 However, that is clearly analogous to creating an array of "void"
8746 or a reference to a reference. This is core issue #486. */
8747 if (TREE_CODE (return_type) == ARRAY_TYPE
8748 || TREE_CODE (return_type) == FUNCTION_TYPE)
8750 if (complain & tf_error)
8752 if (TREE_CODE (return_type) == ARRAY_TYPE)
8753 error ("function returning an array");
8755 error ("function returning a function");
8757 return error_mark_node;
8760 /* Substitute the argument types. */
8761 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
8763 if (arg_types == error_mark_node)
8764 return error_mark_node;
8766 /* Construct a new type node and return it. */
8767 if (TREE_CODE (t) == FUNCTION_TYPE)
8768 fntype = build_function_type (return_type, arg_types);
8771 tree r = TREE_TYPE (TREE_VALUE (arg_types));
8772 if (! MAYBE_CLASS_TYPE_P (r))
8776 Type deduction may fail for any of the following
8779 -- Attempting to create "pointer to member of T" when T
8780 is not a class type. */
8781 if (complain & tf_error)
8782 error ("creating pointer to member function of non-class type %qT",
8784 return error_mark_node;
8787 fntype = build_method_type_directly (r, return_type,
8788 TREE_CHAIN (arg_types));
8790 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
8791 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
8796 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
8797 ARGS into that specification, and return the substituted
8798 specification. If there is no specification, return NULL_TREE. */
8801 tsubst_exception_specification (tree fntype,
8803 tsubst_flags_t complain,
8809 specs = TYPE_RAISES_EXCEPTIONS (fntype);
8810 new_specs = NULL_TREE;
8813 if (! TREE_VALUE (specs))
8820 tree expanded_specs = NULL_TREE;
8822 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
8824 /* Expand the pack expansion type. */
8825 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
8829 if (expanded_specs == error_mark_node)
8830 return error_mark_node;
8831 else if (TREE_CODE (expanded_specs) == TREE_VEC)
8832 len = TREE_VEC_LENGTH (expanded_specs);
8835 /* We're substituting into a member template, so
8836 we got a TYPE_PACK_EXPANSION back. Add that
8837 expansion and move on. */
8838 gcc_assert (TREE_CODE (expanded_specs)
8839 == TYPE_PACK_EXPANSION);
8840 new_specs = add_exception_specifier (new_specs,
8843 specs = TREE_CHAIN (specs);
8848 for (i = 0; i < len; ++i)
8851 spec = TREE_VEC_ELT (expanded_specs, i);
8853 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
8854 if (spec == error_mark_node)
8856 new_specs = add_exception_specifier (new_specs, spec,
8860 specs = TREE_CHAIN (specs);
8866 /* Take the tree structure T and replace template parameters used
8867 therein with the argument vector ARGS. IN_DECL is an associated
8868 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
8869 Issue error and warning messages under control of COMPLAIN. Note
8870 that we must be relatively non-tolerant of extensions here, in
8871 order to preserve conformance; if we allow substitutions that
8872 should not be allowed, we may allow argument deductions that should
8873 not succeed, and therefore report ambiguous overload situations
8874 where there are none. In theory, we could allow the substitution,
8875 but indicate that it should have failed, and allow our caller to
8876 make sure that the right thing happens, but we don't try to do this
8879 This function is used for dealing with types, decls and the like;
8880 for expressions, use tsubst_expr or tsubst_copy. */
8883 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8887 if (t == NULL_TREE || t == error_mark_node
8888 || t == integer_type_node
8889 || t == void_type_node
8890 || t == char_type_node
8891 || t == unknown_type_node
8892 || TREE_CODE (t) == NAMESPACE_DECL)
8896 return tsubst_decl (t, args, complain);
8898 if (TREE_CODE (t) == IDENTIFIER_NODE)
8899 type = IDENTIFIER_TYPE_VALUE (t);
8901 type = TREE_TYPE (t);
8903 gcc_assert (type != unknown_type_node);
8905 /* Reuse typedefs. We need to do this to handle dependent attributes,
8906 such as attribute aligned. */
8909 && TYPE_NAME (t) != TYPE_MAIN_DECL (t))
8911 tree decl = TYPE_NAME (t);
8913 if (DECL_CLASS_SCOPE_P (decl)
8914 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
8915 && uses_template_parms (DECL_CONTEXT (decl)))
8917 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
8918 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
8919 r = retrieve_specialization (tmpl, gen_args, false);
8921 else if (DECL_FUNCTION_SCOPE_P (decl)
8922 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
8923 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
8924 r = retrieve_local_specialization (decl);
8926 /* The typedef is from a non-template context. */
8932 r = cp_build_qualified_type_real
8933 (r, cp_type_quals (t) | cp_type_quals (r),
8934 complain | tf_ignore_bad_quals);
8937 /* Else we must be instantiating the typedef, so fall through. */
8941 && TREE_CODE (t) != TYPENAME_TYPE
8942 && TREE_CODE (t) != IDENTIFIER_NODE
8943 && TREE_CODE (t) != FUNCTION_TYPE
8944 && TREE_CODE (t) != METHOD_TYPE)
8945 type = tsubst (type, args, complain, in_decl);
8946 if (type == error_mark_node)
8947 return error_mark_node;
8949 switch (TREE_CODE (t))
8954 return tsubst_aggr_type (t, args, complain, in_decl,
8955 /*entering_scope=*/0);
8958 case IDENTIFIER_NODE:
8970 if (t == integer_type_node)
8973 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
8974 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
8978 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
8980 max = tsubst_expr (omax, args, complain, in_decl,
8981 /*integral_constant_expression_p=*/false);
8982 max = fold_decl_constant_value (max);
8984 if (TREE_CODE (max) != INTEGER_CST
8985 && !at_function_scope_p ()
8986 && !value_dependent_expression_p (max))
8988 if (complain & tf_error)
8989 error ("array bound is not an integer constant");
8990 return error_mark_node;
8995 Type deduction may fail for any of the following
8998 Attempting to create an array with a size that is
8999 zero or negative. */
9000 if (integer_zerop (max) && !(complain & tf_error))
9001 /* We must fail if performing argument deduction (as
9002 indicated by the state of complain), so that
9003 another substitution can be found. */
9004 return error_mark_node;
9005 else if (TREE_CODE (max) == INTEGER_CST
9006 && INT_CST_LT (max, integer_zero_node))
9008 if (complain & tf_error)
9009 error ("creating array with negative size (%qE)", max);
9011 return error_mark_node;
9014 return compute_array_index_type (NULL_TREE, max);
9017 case TEMPLATE_TYPE_PARM:
9018 case TEMPLATE_TEMPLATE_PARM:
9019 case BOUND_TEMPLATE_TEMPLATE_PARM:
9020 case TEMPLATE_PARM_INDEX:
9025 tree arg = NULL_TREE;
9029 gcc_assert (TREE_VEC_LENGTH (args) > 0);
9030 template_parm_level_and_index (t, &level, &idx);
9032 levels = TMPL_ARGS_DEPTH (args);
9033 if (level <= levels)
9035 arg = TMPL_ARG (args, level, idx);
9037 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
9038 /* See through ARGUMENT_PACK_SELECT arguments. */
9039 arg = ARGUMENT_PACK_SELECT_ARG (arg);
9042 if (arg == error_mark_node)
9043 return error_mark_node;
9044 else if (arg != NULL_TREE)
9046 if (ARGUMENT_PACK_P (arg))
9047 /* If ARG is an argument pack, we don't actually want to
9048 perform a substitution here, because substitutions
9049 for argument packs are only done
9050 element-by-element. We can get to this point when
9051 substituting the type of a non-type template
9052 parameter pack, when that type actually contains
9053 template parameter packs from an outer template, e.g.,
9055 template<typename... Types> struct A {
9056 template<Types... Values> struct B { };
9060 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
9063 gcc_assert (TYPE_P (arg));
9065 /* cv-quals from the template are discarded when
9066 substituting in a function or reference type. */
9067 if (TREE_CODE (arg) == FUNCTION_TYPE
9068 || TREE_CODE (arg) == METHOD_TYPE
9069 || TREE_CODE (arg) == REFERENCE_TYPE)
9070 quals = cp_type_quals (arg);
9072 quals = cp_type_quals (arg) | cp_type_quals (t);
9074 return cp_build_qualified_type_real
9075 (arg, quals, complain | tf_ignore_bad_quals);
9077 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9079 /* We are processing a type constructed from a
9080 template template parameter. */
9081 tree argvec = tsubst (TYPE_TI_ARGS (t),
9082 args, complain, in_decl);
9083 if (argvec == error_mark_node)
9084 return error_mark_node;
9086 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
9087 are resolving nested-types in the signature of a
9088 member function templates. Otherwise ARG is a
9089 TEMPLATE_DECL and is the real template to be
9091 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
9092 arg = TYPE_NAME (arg);
9094 r = lookup_template_class (arg,
9097 /*entering_scope=*/0,
9099 return cp_build_qualified_type_real
9100 (r, TYPE_QUALS (t), complain);
9103 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
9108 /* This can happen during the attempted tsubst'ing in
9109 unify. This means that we don't yet have any information
9110 about the template parameter in question. */
9113 /* If we get here, we must have been looking at a parm for a
9114 more deeply nested template. Make a new version of this
9115 template parameter, but with a lower level. */
9116 switch (TREE_CODE (t))
9118 case TEMPLATE_TYPE_PARM:
9119 case TEMPLATE_TEMPLATE_PARM:
9120 case BOUND_TEMPLATE_TEMPLATE_PARM:
9121 if (cp_type_quals (t))
9123 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
9124 r = cp_build_qualified_type_real
9125 (r, cp_type_quals (t),
9126 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
9127 ? tf_ignore_bad_quals : 0));
9132 TEMPLATE_TYPE_PARM_INDEX (r)
9133 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
9134 r, levels, args, complain);
9135 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
9136 TYPE_MAIN_VARIANT (r) = r;
9137 TYPE_POINTER_TO (r) = NULL_TREE;
9138 TYPE_REFERENCE_TO (r) = NULL_TREE;
9140 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
9141 /* We have reduced the level of the template
9142 template parameter, but not the levels of its
9143 template parameters, so canonical_type_parameter
9144 will not be able to find the canonical template
9145 template parameter for this level. Thus, we
9146 require structural equality checking to compare
9147 TEMPLATE_TEMPLATE_PARMs. */
9148 SET_TYPE_STRUCTURAL_EQUALITY (r);
9149 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
9150 SET_TYPE_STRUCTURAL_EQUALITY (r);
9152 TYPE_CANONICAL (r) = canonical_type_parameter (r);
9154 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9156 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
9158 if (argvec == error_mark_node)
9159 return error_mark_node;
9161 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
9162 = tree_cons (TYPE_TI_TEMPLATE (t), argvec, NULL_TREE);
9167 case TEMPLATE_PARM_INDEX:
9168 r = reduce_template_parm_level (t, type, levels, args, complain);
9180 tree purpose, value, chain;
9182 if (t == void_list_node)
9185 purpose = TREE_PURPOSE (t);
9188 purpose = tsubst (purpose, args, complain, in_decl);
9189 if (purpose == error_mark_node)
9190 return error_mark_node;
9192 value = TREE_VALUE (t);
9195 value = tsubst (value, args, complain, in_decl);
9196 if (value == error_mark_node)
9197 return error_mark_node;
9199 chain = TREE_CHAIN (t);
9200 if (chain && chain != void_type_node)
9202 chain = tsubst (chain, args, complain, in_decl);
9203 if (chain == error_mark_node)
9204 return error_mark_node;
9206 if (purpose == TREE_PURPOSE (t)
9207 && value == TREE_VALUE (t)
9208 && chain == TREE_CHAIN (t))
9210 return hash_tree_cons (purpose, value, chain);
9214 /* We should never be tsubsting a binfo. */
9218 /* A vector of template arguments. */
9220 return tsubst_template_args (t, args, complain, in_decl);
9223 case REFERENCE_TYPE:
9225 enum tree_code code;
9227 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
9230 code = TREE_CODE (t);
9235 Type deduction may fail for any of the following
9238 -- Attempting to create a pointer to reference type.
9239 -- Attempting to create a reference to a reference type or
9240 a reference to void.
9242 Core issue 106 says that creating a reference to a reference
9243 during instantiation is no longer a cause for failure. We
9244 only enforce this check in strict C++98 mode. */
9245 if ((TREE_CODE (type) == REFERENCE_TYPE
9246 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
9247 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
9249 static location_t last_loc;
9251 /* We keep track of the last time we issued this error
9252 message to avoid spewing a ton of messages during a
9253 single bad template instantiation. */
9254 if (complain & tf_error
9255 && last_loc != input_location)
9257 if (TREE_CODE (type) == VOID_TYPE)
9258 error ("forming reference to void");
9260 error ("forming %s to reference type %qT",
9261 (code == POINTER_TYPE) ? "pointer" : "reference",
9263 last_loc = input_location;
9266 return error_mark_node;
9268 else if (code == POINTER_TYPE)
9270 r = build_pointer_type (type);
9271 if (TREE_CODE (type) == METHOD_TYPE)
9272 r = build_ptrmemfunc_type (r);
9274 else if (TREE_CODE (type) == REFERENCE_TYPE)
9275 /* In C++0x, during template argument substitution, when there is an
9276 attempt to create a reference to a reference type, reference
9277 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
9279 "If a template-argument for a template-parameter T names a type
9280 that is a reference to a type A, an attempt to create the type
9281 'lvalue reference to cv T' creates the type 'lvalue reference to
9282 A,' while an attempt to create the type type rvalue reference to
9283 cv T' creates the type T"
9285 r = cp_build_reference_type
9287 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
9289 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
9290 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
9292 if (r != error_mark_node)
9293 /* Will this ever be needed for TYPE_..._TO values? */
9300 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
9301 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
9305 Type deduction may fail for any of the following
9308 -- Attempting to create "pointer to member of T" when T
9309 is not a class type. */
9310 if (complain & tf_error)
9311 error ("creating pointer to member of non-class type %qT", r);
9312 return error_mark_node;
9314 if (TREE_CODE (type) == REFERENCE_TYPE)
9316 if (complain & tf_error)
9317 error ("creating pointer to member reference type %qT", type);
9318 return error_mark_node;
9320 if (TREE_CODE (type) == VOID_TYPE)
9322 if (complain & tf_error)
9323 error ("creating pointer to member of type void");
9324 return error_mark_node;
9326 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
9327 if (TREE_CODE (type) == FUNCTION_TYPE)
9329 /* The type of the implicit object parameter gets its
9330 cv-qualifiers from the FUNCTION_TYPE. */
9332 tree this_type = cp_build_qualified_type (TYPE_MAIN_VARIANT (r),
9333 cp_type_quals (type));
9335 method_type = build_method_type_directly (this_type,
9337 TYPE_ARG_TYPES (type));
9338 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
9339 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
9343 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
9352 fntype = tsubst_function_type (t, args, complain, in_decl);
9353 if (fntype == error_mark_node)
9354 return error_mark_node;
9356 /* Substitute the exception specification. */
9357 specs = tsubst_exception_specification (t, args, complain,
9359 if (specs == error_mark_node)
9360 return error_mark_node;
9362 fntype = build_exception_variant (fntype, specs);
9367 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
9368 if (domain == error_mark_node)
9369 return error_mark_node;
9371 /* As an optimization, we avoid regenerating the array type if
9372 it will obviously be the same as T. */
9373 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
9376 /* These checks should match the ones in grokdeclarator.
9380 The deduction may fail for any of the following reasons:
9382 -- Attempting to create an array with an element type that
9383 is void, a function type, or a reference type, or [DR337]
9384 an abstract class type. */
9385 if (TREE_CODE (type) == VOID_TYPE
9386 || TREE_CODE (type) == FUNCTION_TYPE
9387 || TREE_CODE (type) == REFERENCE_TYPE)
9389 if (complain & tf_error)
9390 error ("creating array of %qT", type);
9391 return error_mark_node;
9393 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
9395 if (complain & tf_error)
9396 error ("creating array of %qT, which is an abstract class type",
9398 return error_mark_node;
9401 r = build_cplus_array_type (type, domain);
9403 if (TYPE_USER_ALIGN (t))
9405 TYPE_ALIGN (r) = TYPE_ALIGN (t);
9406 TYPE_USER_ALIGN (r) = 1;
9415 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9416 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
9418 if (e1 == error_mark_node || e2 == error_mark_node)
9419 return error_mark_node;
9421 return fold_build2 (TREE_CODE (t), TREE_TYPE (t), e1, e2);
9427 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9428 if (e == error_mark_node)
9429 return error_mark_node;
9431 return fold_build1 (TREE_CODE (t), TREE_TYPE (t), e);
9436 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
9437 in_decl, /*entering_scope=*/1);
9438 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
9441 if (ctx == error_mark_node || f == error_mark_node)
9442 return error_mark_node;
9444 if (!MAYBE_CLASS_TYPE_P (ctx))
9446 if (complain & tf_error)
9447 error ("%qT is not a class, struct, or union type", ctx);
9448 return error_mark_node;
9450 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
9452 /* Normally, make_typename_type does not require that the CTX
9453 have complete type in order to allow things like:
9455 template <class T> struct S { typename S<T>::X Y; };
9457 But, such constructs have already been resolved by this
9458 point, so here CTX really should have complete type, unless
9459 it's a partial instantiation. */
9460 ctx = complete_type (ctx);
9461 if (!COMPLETE_TYPE_P (ctx))
9463 if (complain & tf_error)
9464 cxx_incomplete_type_error (NULL_TREE, ctx);
9465 return error_mark_node;
9469 f = make_typename_type (ctx, f, typename_type,
9470 (complain & tf_error) | tf_keep_type_decl);
9471 if (f == error_mark_node)
9473 if (TREE_CODE (f) == TYPE_DECL)
9475 complain |= tf_ignore_bad_quals;
9479 if (TREE_CODE (f) != TYPENAME_TYPE)
9481 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
9482 error ("%qT resolves to %qT, which is not an enumeration type",
9484 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
9485 error ("%qT resolves to %qT, which is is not a class type",
9489 return cp_build_qualified_type_real
9490 (f, cp_type_quals (f) | cp_type_quals (t), complain);
9493 case UNBOUND_CLASS_TEMPLATE:
9495 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
9496 in_decl, /*entering_scope=*/1);
9497 tree name = TYPE_IDENTIFIER (t);
9498 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
9500 if (ctx == error_mark_node || name == error_mark_node)
9501 return error_mark_node;
9504 parm_list = tsubst_template_parms (parm_list, args, complain);
9505 return make_unbound_class_template (ctx, name, parm_list, complain);
9515 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9516 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl,
9517 /*integral_constant_expression_p=*/false);
9518 if (e1 == error_mark_node || e2 == error_mark_node)
9519 return error_mark_node;
9521 return build_nt (ARRAY_REF, e1, e2, NULL_TREE, NULL_TREE);
9526 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9527 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
9528 if (e1 == error_mark_node || e2 == error_mark_node)
9529 return error_mark_node;
9531 return build_qualified_name (/*type=*/NULL_TREE,
9532 e1, e2, QUALIFIED_NAME_IS_TEMPLATE (t));
9539 type = finish_typeof (tsubst_expr
9540 (TYPEOF_TYPE_EXPR (t), args,
9542 /*integral_constant_expression_p=*/false));
9543 return cp_build_qualified_type_real (type,
9545 | cp_type_quals (type),
9554 finish_decltype_type (tsubst_expr
9555 (DECLTYPE_TYPE_EXPR (t), args,
9557 /*integral_constant_expression_p=*/false),
9558 DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
9559 return cp_build_qualified_type_real (type,
9561 | cp_type_quals (type),
9565 case TYPE_ARGUMENT_PACK:
9566 case NONTYPE_ARGUMENT_PACK:
9568 tree r = make_node (TREE_CODE (t));
9570 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
9574 SET_ARGUMENT_PACK_ARGS (r, packed_out);
9576 /* For template nontype argument packs, also substitute into
9578 if (TREE_CODE (t) == NONTYPE_ARGUMENT_PACK)
9579 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
9586 sorry ("use of %qs in template",
9587 tree_code_name [(int) TREE_CODE (t)]);
9588 return error_mark_node;
9592 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
9593 type of the expression on the left-hand side of the "." or "->"
9597 tsubst_baselink (tree baselink, tree object_type,
9598 tree args, tsubst_flags_t complain, tree in_decl)
9601 tree qualifying_scope;
9604 tree template_args = 0;
9605 bool template_id_p = false;
9607 /* A baselink indicates a function from a base class. Both the
9608 BASELINK_ACCESS_BINFO and the base class referenced may
9609 indicate bases of the template class, rather than the
9610 instantiated class. In addition, lookups that were not
9611 ambiguous before may be ambiguous now. Therefore, we perform
9612 the lookup again. */
9613 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
9614 qualifying_scope = tsubst (qualifying_scope, args,
9616 fns = BASELINK_FUNCTIONS (baselink);
9617 optype = BASELINK_OPTYPE (baselink);
9618 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
9620 template_id_p = true;
9621 template_args = TREE_OPERAND (fns, 1);
9622 fns = TREE_OPERAND (fns, 0);
9624 template_args = tsubst_template_args (template_args, args,
9627 name = DECL_NAME (get_first_fn (fns));
9628 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
9630 /* If lookup found a single function, mark it as used at this
9631 point. (If it lookup found multiple functions the one selected
9632 later by overload resolution will be marked as used at that
9634 if (BASELINK_P (baselink))
9635 fns = BASELINK_FUNCTIONS (baselink);
9636 if (!template_id_p && !really_overloaded_fn (fns))
9637 mark_used (OVL_CURRENT (fns));
9639 /* Add back the template arguments, if present. */
9640 if (BASELINK_P (baselink) && template_id_p)
9641 BASELINK_FUNCTIONS (baselink)
9642 = build_nt (TEMPLATE_ID_EXPR,
9643 BASELINK_FUNCTIONS (baselink),
9645 /* Update the conversion operator type. */
9646 BASELINK_OPTYPE (baselink)
9647 = tsubst (optype, args, complain, in_decl);
9650 object_type = current_class_type;
9651 return adjust_result_of_qualified_name_lookup (baselink,
9656 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
9657 true if the qualified-id will be a postfix-expression in-and-of
9658 itself; false if more of the postfix-expression follows the
9659 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
9663 tsubst_qualified_id (tree qualified_id, tree args,
9664 tsubst_flags_t complain, tree in_decl,
9665 bool done, bool address_p)
9673 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
9675 /* Figure out what name to look up. */
9676 name = TREE_OPERAND (qualified_id, 1);
9677 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
9680 template_args = TREE_OPERAND (name, 1);
9682 template_args = tsubst_template_args (template_args, args,
9684 name = TREE_OPERAND (name, 0);
9688 is_template = false;
9689 template_args = NULL_TREE;
9692 /* Substitute into the qualifying scope. When there are no ARGS, we
9693 are just trying to simplify a non-dependent expression. In that
9694 case the qualifying scope may be dependent, and, in any case,
9695 substituting will not help. */
9696 scope = TREE_OPERAND (qualified_id, 0);
9699 scope = tsubst (scope, args, complain, in_decl);
9700 expr = tsubst_copy (name, args, complain, in_decl);
9705 if (dependent_type_p (scope))
9706 return build_qualified_name (/*type=*/NULL_TREE,
9708 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
9710 if (!BASELINK_P (name) && !DECL_P (expr))
9712 if (TREE_CODE (expr) == BIT_NOT_EXPR)
9713 /* If this were actually a destructor call, it would have been
9714 parsed as such by the parser. */
9715 expr = error_mark_node;
9717 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
9718 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
9719 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
9721 if (complain & tf_error)
9723 error ("dependent-name %qE is parsed as a non-type, but "
9724 "instantiation yields a type", qualified_id);
9725 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
9727 return error_mark_node;
9733 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
9735 /* Remember that there was a reference to this entity. */
9739 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
9741 if (complain & tf_error)
9742 qualified_name_lookup_error (scope,
9743 TREE_OPERAND (qualified_id, 1),
9744 expr, input_location);
9745 return error_mark_node;
9749 expr = lookup_template_function (expr, template_args);
9751 if (expr == error_mark_node && complain & tf_error)
9752 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
9753 expr, input_location);
9754 else if (TYPE_P (scope))
9756 expr = (adjust_result_of_qualified_name_lookup
9757 (expr, scope, current_class_type));
9758 expr = (finish_qualified_id_expr
9759 (scope, expr, done, address_p,
9760 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
9761 /*template_arg_p=*/false));
9764 /* Expressions do not generally have reference type. */
9765 if (TREE_CODE (expr) != SCOPE_REF
9766 /* However, if we're about to form a pointer-to-member, we just
9767 want the referenced member referenced. */
9768 && TREE_CODE (expr) != OFFSET_REF)
9769 expr = convert_from_reference (expr);
9774 /* Like tsubst, but deals with expressions. This function just replaces
9775 template parms; to finish processing the resultant expression, use
9779 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9781 enum tree_code code;
9784 if (t == NULL_TREE || t == error_mark_node)
9787 code = TREE_CODE (t);
9792 r = retrieve_local_specialization (t);
9793 gcc_assert (r != NULL);
9794 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
9795 r = ARGUMENT_PACK_SELECT_ARG (r);
9804 if (DECL_TEMPLATE_PARM_P (t))
9805 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
9806 /* There is no need to substitute into namespace-scope
9808 if (DECL_NAMESPACE_SCOPE_P (t))
9810 /* If ARGS is NULL, then T is known to be non-dependent. */
9811 if (args == NULL_TREE)
9812 return integral_constant_value (t);
9814 /* Unfortunately, we cannot just call lookup_name here.
9817 template <int I> int f() {
9819 struct S { void g() { E e = a; } };
9822 When we instantiate f<7>::S::g(), say, lookup_name is not
9823 clever enough to find f<7>::a. */
9825 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
9826 /*entering_scope=*/0);
9828 for (v = TYPE_VALUES (enum_type);
9831 if (TREE_PURPOSE (v) == DECL_NAME (t))
9832 return TREE_VALUE (v);
9834 /* We didn't find the name. That should never happen; if
9835 name-lookup found it during preliminary parsing, we
9836 should find it again here during instantiation. */
9842 if (DECL_CONTEXT (t))
9846 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
9847 /*entering_scope=*/1);
9848 if (ctx != DECL_CONTEXT (t))
9850 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
9853 if (complain & tf_error)
9854 error ("using invalid field %qD", t);
9855 return error_mark_node;
9865 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
9866 || local_variable_p (t))
9867 t = tsubst (t, args, complain, in_decl);
9872 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
9875 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9876 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
9877 args, complain, in_decl);
9878 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
9879 return tsubst (t, args, complain, in_decl);
9880 else if (DECL_CLASS_SCOPE_P (t)
9881 && uses_template_parms (DECL_CONTEXT (t)))
9883 /* Template template argument like the following example need
9886 template <template <class> class TT> struct C {};
9887 template <class T> struct D {
9888 template <class U> struct E {};
9893 We are processing the template argument `E' in #1 for
9894 the template instantiation #2. Originally, `E' is a
9895 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
9896 have to substitute this with one having context `D<int>'. */
9898 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
9899 return lookup_field (context, DECL_NAME(t), 0, false);
9902 /* Ordinary template template argument. */
9906 case REINTERPRET_CAST_EXPR:
9907 case CONST_CAST_EXPR:
9908 case STATIC_CAST_EXPR:
9909 case DYNAMIC_CAST_EXPR:
9912 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
9913 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
9916 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
9918 /* We only want to compute the number of arguments. */
9919 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
9923 if (TREE_CODE (expanded) == TREE_VEC)
9924 len = TREE_VEC_LENGTH (expanded);
9926 if (expanded == error_mark_node)
9927 return error_mark_node;
9928 else if (PACK_EXPANSION_P (expanded)
9929 || (TREE_CODE (expanded) == TREE_VEC
9931 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
9933 if (TREE_CODE (expanded) == TREE_VEC)
9934 expanded = TREE_VEC_ELT (expanded, len - 1);
9936 if (TYPE_P (expanded))
9937 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
9938 complain & tf_error);
9940 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
9941 complain & tf_error);
9944 return build_int_cst (size_type_node, len);
9950 case TRUTH_NOT_EXPR:
9953 case UNARY_PLUS_EXPR: /* Unary + */
9961 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
9962 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
9969 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
9970 name = TREE_OPERAND (t, 1);
9971 if (TREE_CODE (name) == BIT_NOT_EXPR)
9973 name = tsubst_copy (TREE_OPERAND (name, 0), args,
9975 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
9977 else if (TREE_CODE (name) == SCOPE_REF
9978 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
9980 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
9982 name = TREE_OPERAND (name, 1);
9983 name = tsubst_copy (TREE_OPERAND (name, 0), args,
9985 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
9986 name = build_qualified_name (/*type=*/NULL_TREE,
9988 /*template_p=*/false);
9990 else if (TREE_CODE (name) == BASELINK)
9991 name = tsubst_baselink (name,
9992 non_reference (TREE_TYPE (object)),
9996 name = tsubst_copy (name, args, complain, in_decl);
9997 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
10003 case TRUNC_DIV_EXPR:
10004 case CEIL_DIV_EXPR:
10005 case FLOOR_DIV_EXPR:
10006 case ROUND_DIV_EXPR:
10007 case EXACT_DIV_EXPR:
10011 case TRUNC_MOD_EXPR:
10012 case FLOOR_MOD_EXPR:
10013 case TRUTH_ANDIF_EXPR:
10014 case TRUTH_ORIF_EXPR:
10015 case TRUTH_AND_EXPR:
10016 case TRUTH_OR_EXPR:
10029 case COMPOUND_EXPR:
10032 case PREDECREMENT_EXPR:
10033 case PREINCREMENT_EXPR:
10034 case POSTDECREMENT_EXPR:
10035 case POSTINCREMENT_EXPR:
10037 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10038 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10041 return build_qualified_name (/*type=*/NULL_TREE,
10042 tsubst_copy (TREE_OPERAND (t, 0),
10043 args, complain, in_decl),
10044 tsubst_copy (TREE_OPERAND (t, 1),
10045 args, complain, in_decl),
10046 QUALIFIED_NAME_IS_TEMPLATE (t));
10051 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10052 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10053 NULL_TREE, NULL_TREE);
10057 int n = VL_EXP_OPERAND_LENGTH (t);
10058 tree result = build_vl_exp (CALL_EXPR, n);
10060 for (i = 0; i < n; i++)
10061 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
10062 complain, in_decl);
10068 case PSEUDO_DTOR_EXPR:
10071 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10072 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10073 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10074 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
10081 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10082 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10083 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10084 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
10091 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10092 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10093 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
10094 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
10098 case TEMPLATE_ID_EXPR:
10100 /* Substituted template arguments */
10101 tree fn = TREE_OPERAND (t, 0);
10102 tree targs = TREE_OPERAND (t, 1);
10104 fn = tsubst_copy (fn, args, complain, in_decl);
10106 targs = tsubst_template_args (targs, args, complain, in_decl);
10108 return lookup_template_function (fn, targs);
10113 tree purpose, value, chain;
10115 if (t == void_list_node)
10118 purpose = TREE_PURPOSE (t);
10120 purpose = tsubst_copy (purpose, args, complain, in_decl);
10121 value = TREE_VALUE (t);
10123 value = tsubst_copy (value, args, complain, in_decl);
10124 chain = TREE_CHAIN (t);
10125 if (chain && chain != void_type_node)
10126 chain = tsubst_copy (chain, args, complain, in_decl);
10127 if (purpose == TREE_PURPOSE (t)
10128 && value == TREE_VALUE (t)
10129 && chain == TREE_CHAIN (t))
10131 return tree_cons (purpose, value, chain);
10136 case ENUMERAL_TYPE:
10138 case TEMPLATE_TYPE_PARM:
10139 case TEMPLATE_TEMPLATE_PARM:
10140 case BOUND_TEMPLATE_TEMPLATE_PARM:
10141 case TEMPLATE_PARM_INDEX:
10143 case REFERENCE_TYPE:
10145 case FUNCTION_TYPE:
10148 case TYPENAME_TYPE:
10149 case UNBOUND_CLASS_TEMPLATE:
10151 case DECLTYPE_TYPE:
10153 return tsubst (t, args, complain, in_decl);
10155 case IDENTIFIER_NODE:
10156 if (IDENTIFIER_TYPENAME_P (t))
10158 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10159 return mangle_conv_op_name_for_type (new_type);
10165 /* This is handled by tsubst_copy_and_build. */
10166 gcc_unreachable ();
10169 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
10171 tsubst (TREE_TYPE (t), args, complain, in_decl));
10173 case CLEANUP_POINT_EXPR:
10174 /* We shouldn't have built any of these during initial template
10175 generation. Instead, they should be built during instantiation
10176 in response to the saved STMT_IS_FULL_EXPR_P setting. */
10177 gcc_unreachable ();
10180 mark_used (TREE_OPERAND (t, 1));
10183 case EXPR_PACK_EXPANSION:
10184 error ("invalid use of pack expansion expression");
10185 return error_mark_node;
10187 case NONTYPE_ARGUMENT_PACK:
10188 error ("use %<...%> to expand argument pack");
10189 return error_mark_node;
10196 /* Like tsubst_copy, but specifically for OpenMP clauses. */
10199 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
10202 tree new_clauses = NULL, nc, oc;
10204 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
10206 nc = copy_node (oc);
10207 OMP_CLAUSE_CHAIN (nc) = new_clauses;
10210 switch (OMP_CLAUSE_CODE (nc))
10212 case OMP_CLAUSE_LASTPRIVATE:
10213 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
10215 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
10216 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
10217 in_decl, /*integral_constant_expression_p=*/false);
10218 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
10219 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
10222 case OMP_CLAUSE_PRIVATE:
10223 case OMP_CLAUSE_SHARED:
10224 case OMP_CLAUSE_FIRSTPRIVATE:
10225 case OMP_CLAUSE_REDUCTION:
10226 case OMP_CLAUSE_COPYIN:
10227 case OMP_CLAUSE_COPYPRIVATE:
10228 case OMP_CLAUSE_IF:
10229 case OMP_CLAUSE_NUM_THREADS:
10230 case OMP_CLAUSE_SCHEDULE:
10231 case OMP_CLAUSE_COLLAPSE:
10232 OMP_CLAUSE_OPERAND (nc, 0)
10233 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
10234 in_decl, /*integral_constant_expression_p=*/false);
10236 case OMP_CLAUSE_NOWAIT:
10237 case OMP_CLAUSE_ORDERED:
10238 case OMP_CLAUSE_DEFAULT:
10239 case OMP_CLAUSE_UNTIED:
10242 gcc_unreachable ();
10246 return finish_omp_clauses (nreverse (new_clauses));
10249 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
10252 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
10255 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
10257 tree purpose, value, chain;
10262 if (TREE_CODE (t) != TREE_LIST)
10263 return tsubst_copy_and_build (t, args, complain, in_decl,
10264 /*function_p=*/false,
10265 /*integral_constant_expression_p=*/false);
10267 if (t == void_list_node)
10270 purpose = TREE_PURPOSE (t);
10272 purpose = RECUR (purpose);
10273 value = TREE_VALUE (t);
10275 value = RECUR (value);
10276 chain = TREE_CHAIN (t);
10277 if (chain && chain != void_type_node)
10278 chain = RECUR (chain);
10279 return tree_cons (purpose, value, chain);
10283 /* Substitute one OMP_FOR iterator. */
10286 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
10287 tree condv, tree incrv, tree *clauses,
10288 tree args, tsubst_flags_t complain, tree in_decl,
10289 bool integral_constant_expression_p)
10291 #define RECUR(NODE) \
10292 tsubst_expr ((NODE), args, complain, in_decl, \
10293 integral_constant_expression_p)
10294 tree decl, init, cond, incr;
10296 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
10297 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
10298 decl = RECUR (TREE_OPERAND (init, 0));
10299 init = TREE_OPERAND (init, 1);
10300 gcc_assert (!type_dependent_expression_p (decl));
10302 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
10304 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
10305 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
10306 if (TREE_CODE (incr) == MODIFY_EXPR)
10307 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
10308 RECUR (TREE_OPERAND (incr, 1)),
10311 incr = RECUR (incr);
10312 TREE_VEC_ELT (declv, i) = decl;
10313 TREE_VEC_ELT (initv, i) = init;
10314 TREE_VEC_ELT (condv, i) = cond;
10315 TREE_VEC_ELT (incrv, i) = incr;
10319 if (init && TREE_CODE (init) != DECL_EXPR)
10322 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
10324 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
10325 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
10326 && OMP_CLAUSE_DECL (c) == decl)
10328 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
10329 && OMP_CLAUSE_DECL (c) == decl)
10330 error ("iteration variable %qD should not be firstprivate", decl);
10331 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
10332 && OMP_CLAUSE_DECL (c) == decl)
10333 error ("iteration variable %qD should not be reduction", decl);
10337 c = build_omp_clause (OMP_CLAUSE_PRIVATE);
10338 OMP_CLAUSE_DECL (c) = decl;
10339 c = finish_omp_clauses (c);
10342 OMP_CLAUSE_CHAIN (c) = *clauses;
10347 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
10348 if (COMPARISON_CLASS_P (cond))
10349 cond = build2 (TREE_CODE (cond), boolean_type_node,
10350 RECUR (TREE_OPERAND (cond, 0)),
10351 RECUR (TREE_OPERAND (cond, 1)));
10353 cond = RECUR (cond);
10354 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
10355 switch (TREE_CODE (incr))
10357 case PREINCREMENT_EXPR:
10358 case PREDECREMENT_EXPR:
10359 case POSTINCREMENT_EXPR:
10360 case POSTDECREMENT_EXPR:
10361 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
10362 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
10365 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
10366 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
10368 tree rhs = TREE_OPERAND (incr, 1);
10369 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
10370 RECUR (TREE_OPERAND (incr, 0)),
10371 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
10372 RECUR (TREE_OPERAND (rhs, 0)),
10373 RECUR (TREE_OPERAND (rhs, 1))));
10376 incr = RECUR (incr);
10379 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
10380 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
10382 tree lhs = RECUR (TREE_OPERAND (incr, 0));
10383 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
10384 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
10385 TREE_TYPE (decl), lhs,
10386 RECUR (TREE_OPERAND (incr, 2))));
10388 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
10389 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
10390 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
10392 tree rhs = TREE_OPERAND (incr, 2);
10393 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
10394 RECUR (TREE_OPERAND (incr, 0)),
10395 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
10396 RECUR (TREE_OPERAND (rhs, 0)),
10397 RECUR (TREE_OPERAND (rhs, 1))));
10400 incr = RECUR (incr);
10403 incr = RECUR (incr);
10407 TREE_VEC_ELT (declv, i) = decl;
10408 TREE_VEC_ELT (initv, i) = init;
10409 TREE_VEC_ELT (condv, i) = cond;
10410 TREE_VEC_ELT (incrv, i) = incr;
10414 /* Like tsubst_copy for expressions, etc. but also does semantic
10418 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
10419 bool integral_constant_expression_p)
10421 #define RECUR(NODE) \
10422 tsubst_expr ((NODE), args, complain, in_decl, \
10423 integral_constant_expression_p)
10427 if (t == NULL_TREE || t == error_mark_node)
10430 if (EXPR_HAS_LOCATION (t))
10431 input_location = EXPR_LOCATION (t);
10432 if (STATEMENT_CODE_P (TREE_CODE (t)))
10433 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
10435 switch (TREE_CODE (t))
10437 case STATEMENT_LIST:
10439 tree_stmt_iterator i;
10440 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
10441 RECUR (tsi_stmt (i));
10445 case CTOR_INITIALIZER:
10446 finish_mem_initializers (tsubst_initializer_list
10447 (TREE_OPERAND (t, 0), args));
10451 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
10455 tmp = RECUR (EXPR_STMT_EXPR (t));
10456 if (EXPR_STMT_STMT_EXPR_RESULT (t))
10457 finish_stmt_expr_expr (tmp, cur_stmt_expr);
10459 finish_expr_stmt (tmp);
10463 do_using_directive (RECUR (USING_STMT_NAMESPACE (t)));
10471 decl = DECL_EXPR_DECL (t);
10472 if (TREE_CODE (decl) == LABEL_DECL)
10473 finish_label_decl (DECL_NAME (decl));
10474 else if (TREE_CODE (decl) == USING_DECL)
10476 tree scope = USING_DECL_SCOPE (decl);
10477 tree name = DECL_NAME (decl);
10480 scope = RECUR (scope);
10481 decl = lookup_qualified_name (scope, name,
10482 /*is_type_p=*/false,
10483 /*complain=*/false);
10484 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
10485 qualified_name_lookup_error (scope, name, decl, input_location);
10487 do_local_using_decl (decl, scope, name);
10491 init = DECL_INITIAL (decl);
10492 decl = tsubst (decl, args, complain, in_decl);
10493 if (decl != error_mark_node)
10495 /* By marking the declaration as instantiated, we avoid
10496 trying to instantiate it. Since instantiate_decl can't
10497 handle local variables, and since we've already done
10498 all that needs to be done, that's the right thing to
10500 if (TREE_CODE (decl) == VAR_DECL)
10501 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
10502 if (TREE_CODE (decl) == VAR_DECL
10503 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
10504 /* Anonymous aggregates are a special case. */
10505 finish_anon_union (decl);
10508 maybe_push_decl (decl);
10509 if (TREE_CODE (decl) == VAR_DECL
10510 && DECL_PRETTY_FUNCTION_P (decl))
10512 /* For __PRETTY_FUNCTION__ we have to adjust the
10514 const char *const name
10515 = cxx_printable_name (current_function_decl, 2);
10516 init = cp_fname_init (name, &TREE_TYPE (decl));
10520 tree t = RECUR (init);
10523 /* If we had an initializer but it
10524 instantiated to nothing,
10525 value-initialize the object. This will
10526 only occur when the initializer was a
10527 pack expansion where the parameter packs
10528 used in that expansion were of length
10530 init = build_default_init (TREE_TYPE (decl),
10536 finish_decl (decl, init, NULL_TREE);
10541 /* A DECL_EXPR can also be used as an expression, in the condition
10542 clause of an if/for/while construct. */
10547 stmt = begin_for_stmt ();
10548 RECUR (FOR_INIT_STMT (t));
10549 finish_for_init_stmt (stmt);
10550 tmp = RECUR (FOR_COND (t));
10551 finish_for_cond (tmp, stmt);
10552 tmp = RECUR (FOR_EXPR (t));
10553 finish_for_expr (tmp, stmt);
10554 RECUR (FOR_BODY (t));
10555 finish_for_stmt (stmt);
10559 stmt = begin_while_stmt ();
10560 tmp = RECUR (WHILE_COND (t));
10561 finish_while_stmt_cond (tmp, stmt);
10562 RECUR (WHILE_BODY (t));
10563 finish_while_stmt (stmt);
10567 stmt = begin_do_stmt ();
10568 RECUR (DO_BODY (t));
10569 finish_do_body (stmt);
10570 tmp = RECUR (DO_COND (t));
10571 finish_do_stmt (tmp, stmt);
10575 stmt = begin_if_stmt ();
10576 tmp = RECUR (IF_COND (t));
10577 finish_if_stmt_cond (tmp, stmt);
10578 RECUR (THEN_CLAUSE (t));
10579 finish_then_clause (stmt);
10581 if (ELSE_CLAUSE (t))
10583 begin_else_clause (stmt);
10584 RECUR (ELSE_CLAUSE (t));
10585 finish_else_clause (stmt);
10588 finish_if_stmt (stmt);
10592 if (BIND_EXPR_BODY_BLOCK (t))
10593 stmt = begin_function_body ();
10595 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
10596 ? BCS_TRY_BLOCK : 0);
10598 RECUR (BIND_EXPR_BODY (t));
10600 if (BIND_EXPR_BODY_BLOCK (t))
10601 finish_function_body (stmt);
10603 finish_compound_stmt (stmt);
10607 finish_break_stmt ();
10610 case CONTINUE_STMT:
10611 finish_continue_stmt ();
10615 stmt = begin_switch_stmt ();
10616 tmp = RECUR (SWITCH_STMT_COND (t));
10617 finish_switch_cond (tmp, stmt);
10618 RECUR (SWITCH_STMT_BODY (t));
10619 finish_switch_stmt (stmt);
10622 case CASE_LABEL_EXPR:
10623 finish_case_label (RECUR (CASE_LOW (t)),
10624 RECUR (CASE_HIGH (t)));
10628 finish_label_stmt (DECL_NAME (LABEL_EXPR_LABEL (t)));
10632 tmp = GOTO_DESTINATION (t);
10633 if (TREE_CODE (tmp) != LABEL_DECL)
10634 /* Computed goto's must be tsubst'd into. On the other hand,
10635 non-computed gotos must not be; the identifier in question
10636 will have no binding. */
10639 tmp = DECL_NAME (tmp);
10640 finish_goto_stmt (tmp);
10644 tmp = finish_asm_stmt
10645 (ASM_VOLATILE_P (t),
10646 RECUR (ASM_STRING (t)),
10647 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
10648 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
10649 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl));
10651 tree asm_expr = tmp;
10652 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
10653 asm_expr = TREE_OPERAND (asm_expr, 0);
10654 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
10661 stmt = begin_try_block ();
10662 RECUR (TRY_STMTS (t));
10663 finish_cleanup_try_block (stmt);
10664 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
10668 tree compound_stmt = NULL_TREE;
10670 if (FN_TRY_BLOCK_P (t))
10671 stmt = begin_function_try_block (&compound_stmt);
10673 stmt = begin_try_block ();
10675 RECUR (TRY_STMTS (t));
10677 if (FN_TRY_BLOCK_P (t))
10678 finish_function_try_block (stmt);
10680 finish_try_block (stmt);
10682 RECUR (TRY_HANDLERS (t));
10683 if (FN_TRY_BLOCK_P (t))
10684 finish_function_handler_sequence (stmt, compound_stmt);
10686 finish_handler_sequence (stmt);
10692 tree decl = HANDLER_PARMS (t);
10696 decl = tsubst (decl, args, complain, in_decl);
10697 /* Prevent instantiate_decl from trying to instantiate
10698 this variable. We've already done all that needs to be
10700 if (decl != error_mark_node)
10701 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
10703 stmt = begin_handler ();
10704 finish_handler_parms (decl, stmt);
10705 RECUR (HANDLER_BODY (t));
10706 finish_handler (stmt);
10711 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
10714 case STATIC_ASSERT:
10717 tsubst_expr (STATIC_ASSERT_CONDITION (t),
10720 /*integral_constant_expression_p=*/true);
10721 finish_static_assert (condition,
10722 STATIC_ASSERT_MESSAGE (t),
10723 STATIC_ASSERT_SOURCE_LOCATION (t),
10724 /*member_p=*/false);
10729 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
10730 args, complain, in_decl);
10731 stmt = begin_omp_parallel ();
10732 RECUR (OMP_PARALLEL_BODY (t));
10733 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
10734 = OMP_PARALLEL_COMBINED (t);
10738 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
10739 args, complain, in_decl);
10740 stmt = begin_omp_task ();
10741 RECUR (OMP_TASK_BODY (t));
10742 finish_omp_task (tmp, stmt);
10747 tree clauses, body, pre_body;
10748 tree declv, initv, condv, incrv;
10751 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
10752 args, complain, in_decl);
10753 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
10754 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
10755 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
10756 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
10758 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
10759 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
10760 &clauses, args, complain, in_decl,
10761 integral_constant_expression_p);
10763 stmt = begin_omp_structured_block ();
10765 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
10766 if (TREE_VEC_ELT (initv, i) == NULL
10767 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
10768 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
10769 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
10771 tree init = RECUR (TREE_VEC_ELT (initv, i));
10772 gcc_assert (init == TREE_VEC_ELT (declv, i));
10773 TREE_VEC_ELT (initv, i) = NULL_TREE;
10777 tree decl_expr = TREE_VEC_ELT (initv, i);
10778 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
10779 gcc_assert (init != NULL);
10780 TREE_VEC_ELT (initv, i) = RECUR (init);
10781 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
10783 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
10786 pre_body = push_stmt_list ();
10787 RECUR (OMP_FOR_PRE_BODY (t));
10788 pre_body = pop_stmt_list (pre_body);
10790 body = push_stmt_list ();
10791 RECUR (OMP_FOR_BODY (t));
10792 body = pop_stmt_list (body);
10794 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
10795 body, pre_body, clauses);
10797 add_stmt (finish_omp_structured_block (stmt));
10803 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
10804 stmt = push_stmt_list ();
10805 RECUR (OMP_BODY (t));
10806 stmt = pop_stmt_list (stmt);
10809 OMP_BODY (t) = stmt;
10810 OMP_CLAUSES (t) = tmp;
10818 stmt = push_stmt_list ();
10819 RECUR (OMP_BODY (t));
10820 stmt = pop_stmt_list (stmt);
10823 OMP_BODY (t) = stmt;
10828 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
10830 tree op1 = TREE_OPERAND (t, 1);
10831 tree lhs = RECUR (TREE_OPERAND (op1, 0));
10832 tree rhs = RECUR (TREE_OPERAND (op1, 1));
10833 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
10837 case EXPR_PACK_EXPANSION:
10838 error ("invalid use of pack expansion expression");
10839 return error_mark_node;
10841 case NONTYPE_ARGUMENT_PACK:
10842 error ("use %<...%> to expand argument pack");
10843 return error_mark_node;
10846 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
10848 return tsubst_copy_and_build (t, args, complain, in_decl,
10849 /*function_p=*/false,
10850 integral_constant_expression_p);
10857 /* T is a postfix-expression that is not being used in a function
10858 call. Return the substituted version of T. */
10861 tsubst_non_call_postfix_expression (tree t, tree args,
10862 tsubst_flags_t complain,
10865 if (TREE_CODE (t) == SCOPE_REF)
10866 t = tsubst_qualified_id (t, args, complain, in_decl,
10867 /*done=*/false, /*address_p=*/false);
10869 t = tsubst_copy_and_build (t, args, complain, in_decl,
10870 /*function_p=*/false,
10871 /*integral_constant_expression_p=*/false);
10876 /* Like tsubst but deals with expressions and performs semantic
10877 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
10880 tsubst_copy_and_build (tree t,
10882 tsubst_flags_t complain,
10885 bool integral_constant_expression_p)
10887 #define RECUR(NODE) \
10888 tsubst_copy_and_build (NODE, args, complain, in_decl, \
10889 /*function_p=*/false, \
10890 integral_constant_expression_p)
10894 if (t == NULL_TREE || t == error_mark_node)
10897 switch (TREE_CODE (t))
10901 /* Fall through. */
10902 case IDENTIFIER_NODE:
10906 bool non_integral_constant_expression_p;
10907 const char *error_msg;
10909 if (IDENTIFIER_TYPENAME_P (t))
10911 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10912 t = mangle_conv_op_name_for_type (new_type);
10915 /* Look up the name. */
10916 decl = lookup_name (t);
10918 /* By convention, expressions use ERROR_MARK_NODE to indicate
10919 failure, not NULL_TREE. */
10920 if (decl == NULL_TREE)
10921 decl = error_mark_node;
10923 decl = finish_id_expression (t, decl, NULL_TREE,
10925 integral_constant_expression_p,
10926 /*allow_non_integral_constant_expression_p=*/false,
10927 &non_integral_constant_expression_p,
10928 /*template_p=*/false,
10930 /*address_p=*/false,
10931 /*template_arg_p=*/false,
10936 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
10937 decl = unqualified_name_lookup_error (decl);
10941 case TEMPLATE_ID_EXPR:
10944 tree templ = RECUR (TREE_OPERAND (t, 0));
10945 tree targs = TREE_OPERAND (t, 1);
10948 targs = tsubst_template_args (targs, args, complain, in_decl);
10950 if (TREE_CODE (templ) == COMPONENT_REF)
10952 object = TREE_OPERAND (templ, 0);
10953 templ = TREE_OPERAND (templ, 1);
10956 object = NULL_TREE;
10957 templ = lookup_template_function (templ, targs);
10960 return build3 (COMPONENT_REF, TREE_TYPE (templ),
10961 object, templ, NULL_TREE);
10963 return baselink_for_fns (templ);
10968 tree r = RECUR (TREE_OPERAND (t, 0));
10970 if (REFERENCE_REF_P (t))
10972 /* A type conversion to reference type will be enclosed in
10973 such an indirect ref, but the substitution of the cast
10974 will have also added such an indirect ref. */
10975 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
10976 r = convert_from_reference (r);
10979 r = build_x_indirect_ref (r, "unary *", complain);
10985 (tsubst (TREE_TYPE (t), args, complain, in_decl),
10986 RECUR (TREE_OPERAND (t, 0)));
10989 case REINTERPRET_CAST_EXPR:
10990 case CONST_CAST_EXPR:
10991 case DYNAMIC_CAST_EXPR:
10992 case STATIC_CAST_EXPR:
10997 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10998 if (integral_constant_expression_p
10999 && !cast_valid_in_integral_constant_expression_p (type))
11001 if (complain & tf_error)
11002 error ("a cast to a type other than an integral or "
11003 "enumeration type cannot appear in a constant-expression");
11004 return error_mark_node;
11007 op = RECUR (TREE_OPERAND (t, 0));
11009 switch (TREE_CODE (t))
11012 return build_functional_cast (type, op, complain);
11013 case REINTERPRET_CAST_EXPR:
11014 return build_reinterpret_cast (type, op, complain);
11015 case CONST_CAST_EXPR:
11016 return build_const_cast (type, op, complain);
11017 case DYNAMIC_CAST_EXPR:
11018 return build_dynamic_cast (type, op, complain);
11019 case STATIC_CAST_EXPR:
11020 return build_static_cast (type, op, complain);
11022 gcc_unreachable ();
11026 case POSTDECREMENT_EXPR:
11027 case POSTINCREMENT_EXPR:
11028 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11029 args, complain, in_decl);
11030 return build_x_unary_op (TREE_CODE (t), op1, complain);
11032 case PREDECREMENT_EXPR:
11033 case PREINCREMENT_EXPR:
11037 case TRUTH_NOT_EXPR:
11038 case UNARY_PLUS_EXPR: /* Unary + */
11039 case REALPART_EXPR:
11040 case IMAGPART_EXPR:
11041 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
11045 op1 = TREE_OPERAND (t, 0);
11046 if (TREE_CODE (op1) == SCOPE_REF)
11047 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
11048 /*done=*/true, /*address_p=*/true);
11050 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
11052 if (TREE_CODE (op1) == LABEL_DECL)
11053 return finish_label_address_expr (DECL_NAME (op1));
11054 return build_x_unary_op (ADDR_EXPR, op1, complain);
11059 case TRUNC_DIV_EXPR:
11060 case CEIL_DIV_EXPR:
11061 case FLOOR_DIV_EXPR:
11062 case ROUND_DIV_EXPR:
11063 case EXACT_DIV_EXPR:
11067 case TRUNC_MOD_EXPR:
11068 case FLOOR_MOD_EXPR:
11069 case TRUTH_ANDIF_EXPR:
11070 case TRUTH_ORIF_EXPR:
11071 case TRUTH_AND_EXPR:
11072 case TRUTH_OR_EXPR:
11087 return build_x_binary_op
11089 RECUR (TREE_OPERAND (t, 0)),
11090 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
11092 : TREE_CODE (TREE_OPERAND (t, 0))),
11093 RECUR (TREE_OPERAND (t, 1)),
11094 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
11096 : TREE_CODE (TREE_OPERAND (t, 1))),
11097 /*overloaded_p=*/NULL,
11101 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
11102 /*address_p=*/false);
11104 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11105 args, complain, in_decl);
11106 return build_x_binary_op (ARRAY_REF, op1,
11107 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
11109 : TREE_CODE (TREE_OPERAND (t, 0))),
11110 RECUR (TREE_OPERAND (t, 1)),
11111 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
11113 : TREE_CODE (TREE_OPERAND (t, 1))),
11114 /*overloaded_p=*/NULL,
11118 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11119 return tsubst_copy (t, args, complain, in_decl);
11123 op1 = TREE_OPERAND (t, 0);
11126 /* When there are no ARGS, we are trying to evaluate a
11127 non-dependent expression from the parser. Trying to do
11128 the substitutions may not work. */
11130 op1 = TREE_TYPE (op1);
11135 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
11136 /*function_p=*/false,
11137 /*integral_constant_expression_p=*/false);
11141 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
11142 complain & tf_error);
11144 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
11145 complain & tf_error);
11149 tree r = build_x_modify_expr
11150 (RECUR (TREE_OPERAND (t, 0)),
11151 TREE_CODE (TREE_OPERAND (t, 1)),
11152 RECUR (TREE_OPERAND (t, 2)),
11154 /* TREE_NO_WARNING must be set if either the expression was
11155 parenthesized or it uses an operator such as >>= rather
11156 than plain assignment. In the former case, it was already
11157 set and must be copied. In the latter case,
11158 build_x_modify_expr sets it and it must not be reset
11160 if (TREE_NO_WARNING (t))
11161 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11166 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11167 args, complain, in_decl);
11168 /* Remember that there was a reference to this entity. */
11171 return build_x_arrow (op1);
11175 tree init = RECUR (TREE_OPERAND (t, 3));
11177 if (TREE_OPERAND (t, 3) && !init)
11178 /* If there was an initializer in the original tree, but
11179 it instantiated to an empty list, then we should pass on
11180 VOID_ZERO_NODE to tell build_new that it was an empty
11181 initializer () rather than no initializer. This can only
11182 happen when the initializer is a pack expansion whose
11183 parameter packs are of length zero. */
11184 init = void_zero_node;
11187 (RECUR (TREE_OPERAND (t, 0)),
11188 RECUR (TREE_OPERAND (t, 1)),
11189 RECUR (TREE_OPERAND (t, 2)),
11191 NEW_EXPR_USE_GLOBAL (t),
11196 return delete_sanity
11197 (RECUR (TREE_OPERAND (t, 0)),
11198 RECUR (TREE_OPERAND (t, 1)),
11199 DELETE_EXPR_USE_VEC (t),
11200 DELETE_EXPR_USE_GLOBAL (t));
11202 case COMPOUND_EXPR:
11203 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
11204 RECUR (TREE_OPERAND (t, 1)),
11214 function = CALL_EXPR_FN (t);
11215 /* When we parsed the expression, we determined whether or
11216 not Koenig lookup should be performed. */
11217 koenig_p = KOENIG_LOOKUP_P (t);
11218 if (TREE_CODE (function) == SCOPE_REF)
11220 qualified_p = true;
11221 function = tsubst_qualified_id (function, args, complain, in_decl,
11223 /*address_p=*/false);
11227 if (TREE_CODE (function) == COMPONENT_REF)
11229 tree op = TREE_OPERAND (function, 1);
11231 qualified_p = (TREE_CODE (op) == SCOPE_REF
11232 || (BASELINK_P (op)
11233 && BASELINK_QUALIFIED_P (op)));
11236 qualified_p = false;
11238 function = tsubst_copy_and_build (function, args, complain,
11241 integral_constant_expression_p);
11243 if (BASELINK_P (function))
11244 qualified_p = true;
11247 /* FIXME: Rewrite this so as not to construct an arglist. */
11248 call_args = RECUR (CALL_EXPR_ARGS (t));
11250 /* We do not perform argument-dependent lookup if normal
11251 lookup finds a non-function, in accordance with the
11252 expected resolution of DR 218. */
11254 && ((is_overloaded_fn (function)
11255 /* If lookup found a member function, the Koenig lookup is
11256 not appropriate, even if an unqualified-name was used
11257 to denote the function. */
11258 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
11259 || TREE_CODE (function) == IDENTIFIER_NODE))
11260 function = perform_koenig_lookup (function, call_args);
11262 if (TREE_CODE (function) == IDENTIFIER_NODE)
11264 unqualified_name_lookup_error (function);
11265 return error_mark_node;
11268 /* Remember that there was a reference to this entity. */
11269 if (DECL_P (function))
11270 mark_used (function);
11272 if (TREE_CODE (function) == OFFSET_REF)
11273 return build_offset_ref_call_from_tree (function, call_args);
11274 if (TREE_CODE (function) == COMPONENT_REF)
11276 if (!BASELINK_P (TREE_OPERAND (function, 1)))
11277 return finish_call_expr (function, call_args,
11278 /*disallow_virtual=*/false,
11279 /*koenig_p=*/false,
11282 return (build_new_method_call
11283 (TREE_OPERAND (function, 0),
11284 TREE_OPERAND (function, 1),
11285 call_args, NULL_TREE,
11286 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
11290 return finish_call_expr (function, call_args,
11291 /*disallow_virtual=*/qualified_p,
11297 return build_x_conditional_expr
11298 (RECUR (TREE_OPERAND (t, 0)),
11299 RECUR (TREE_OPERAND (t, 1)),
11300 RECUR (TREE_OPERAND (t, 2)),
11303 case PSEUDO_DTOR_EXPR:
11304 return finish_pseudo_destructor_expr
11305 (RECUR (TREE_OPERAND (t, 0)),
11306 RECUR (TREE_OPERAND (t, 1)),
11307 RECUR (TREE_OPERAND (t, 2)));
11311 tree purpose, value, chain;
11313 if (t == void_list_node)
11316 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
11317 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
11319 /* We have pack expansions, so expand those and
11320 create a new list out of it. */
11321 tree purposevec = NULL_TREE;
11322 tree valuevec = NULL_TREE;
11326 /* Expand the argument expressions. */
11327 if (TREE_PURPOSE (t))
11328 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
11329 complain, in_decl);
11330 if (TREE_VALUE (t))
11331 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
11332 complain, in_decl);
11334 /* Build the rest of the list. */
11335 chain = TREE_CHAIN (t);
11336 if (chain && chain != void_type_node)
11337 chain = RECUR (chain);
11339 /* Determine the number of arguments. */
11340 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
11342 len = TREE_VEC_LENGTH (purposevec);
11343 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
11345 else if (TREE_CODE (valuevec) == TREE_VEC)
11346 len = TREE_VEC_LENGTH (valuevec);
11349 /* Since we only performed a partial substitution into
11350 the argument pack, we only return a single list
11352 if (purposevec == TREE_PURPOSE (t)
11353 && valuevec == TREE_VALUE (t)
11354 && chain == TREE_CHAIN (t))
11357 return tree_cons (purposevec, valuevec, chain);
11360 /* Convert the argument vectors into a TREE_LIST */
11364 /* Grab the Ith values. */
11366 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
11369 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
11372 /* Build the list (backwards). */
11373 chain = tree_cons (purpose, value, chain);
11379 purpose = TREE_PURPOSE (t);
11381 purpose = RECUR (purpose);
11382 value = TREE_VALUE (t);
11384 value = RECUR (value);
11385 chain = TREE_CHAIN (t);
11386 if (chain && chain != void_type_node)
11387 chain = RECUR (chain);
11388 if (purpose == TREE_PURPOSE (t)
11389 && value == TREE_VALUE (t)
11390 && chain == TREE_CHAIN (t))
11392 return tree_cons (purpose, value, chain);
11395 case COMPONENT_REF:
11401 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11402 args, complain, in_decl);
11403 /* Remember that there was a reference to this entity. */
11404 if (DECL_P (object))
11405 mark_used (object);
11406 object_type = TREE_TYPE (object);
11408 member = TREE_OPERAND (t, 1);
11409 if (BASELINK_P (member))
11410 member = tsubst_baselink (member,
11411 non_reference (TREE_TYPE (object)),
11412 args, complain, in_decl);
11414 member = tsubst_copy (member, args, complain, in_decl);
11415 if (member == error_mark_node)
11416 return error_mark_node;
11418 if (object_type && !CLASS_TYPE_P (object_type))
11420 if (SCALAR_TYPE_P (object_type))
11422 tree s = NULL_TREE;
11423 tree dtor = member;
11425 if (TREE_CODE (dtor) == SCOPE_REF)
11427 s = TREE_OPERAND (dtor, 0);
11428 dtor = TREE_OPERAND (dtor, 1);
11430 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
11432 dtor = TREE_OPERAND (dtor, 0);
11434 return finish_pseudo_destructor_expr (object, s, dtor);
11438 else if (TREE_CODE (member) == SCOPE_REF
11439 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
11444 /* Lookup the template functions now that we know what the
11446 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
11447 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
11448 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
11449 /*is_type_p=*/false,
11450 /*complain=*/false);
11451 if (BASELINK_P (member))
11453 BASELINK_FUNCTIONS (member)
11454 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
11456 member = (adjust_result_of_qualified_name_lookup
11457 (member, BINFO_TYPE (BASELINK_BINFO (member)),
11462 qualified_name_lookup_error (object_type, tmpl, member,
11464 return error_mark_node;
11467 else if (TREE_CODE (member) == SCOPE_REF
11468 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
11469 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
11471 if (complain & tf_error)
11473 if (TYPE_P (TREE_OPERAND (member, 0)))
11474 error ("%qT is not a class or namespace",
11475 TREE_OPERAND (member, 0));
11477 error ("%qD is not a class or namespace",
11478 TREE_OPERAND (member, 0));
11480 return error_mark_node;
11482 else if (TREE_CODE (member) == FIELD_DECL)
11483 return finish_non_static_data_member (member, object, NULL_TREE);
11485 return finish_class_member_access_expr (object, member,
11486 /*template_p=*/false,
11492 (RECUR (TREE_OPERAND (t, 0)));
11496 VEC(constructor_elt,gc) *n;
11497 constructor_elt *ce;
11498 unsigned HOST_WIDE_INT idx;
11499 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11500 bool process_index_p;
11502 bool need_copy_p = false;
11505 if (type == error_mark_node)
11506 return error_mark_node;
11508 /* digest_init will do the wrong thing if we let it. */
11509 if (type && TYPE_PTRMEMFUNC_P (type))
11512 /* We do not want to process the index of aggregate
11513 initializers as they are identifier nodes which will be
11514 looked up by digest_init. */
11515 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
11517 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
11518 newlen = VEC_length (constructor_elt, n);
11519 for (idx = 0; VEC_iterate (constructor_elt, n, idx, ce); idx++)
11521 if (ce->index && process_index_p)
11522 ce->index = RECUR (ce->index);
11524 if (PACK_EXPANSION_P (ce->value))
11526 /* Substitute into the pack expansion. */
11527 ce->value = tsubst_pack_expansion (ce->value, args, complain,
11530 if (ce->value == error_mark_node)
11532 else if (TREE_VEC_LENGTH (ce->value) == 1)
11533 /* Just move the argument into place. */
11534 ce->value = TREE_VEC_ELT (ce->value, 0);
11537 /* Update the length of the final CONSTRUCTOR
11538 arguments vector, and note that we will need to
11540 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
11541 need_copy_p = true;
11545 ce->value = RECUR (ce->value);
11550 VEC(constructor_elt,gc) *old_n = n;
11552 n = VEC_alloc (constructor_elt, gc, newlen);
11553 for (idx = 0; VEC_iterate (constructor_elt, old_n, idx, ce);
11556 if (TREE_CODE (ce->value) == TREE_VEC)
11558 int i, len = TREE_VEC_LENGTH (ce->value);
11559 for (i = 0; i < len; ++i)
11560 CONSTRUCTOR_APPEND_ELT (n, 0,
11561 TREE_VEC_ELT (ce->value, i));
11564 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
11568 r = build_constructor (init_list_type_node, n);
11570 if (TREE_HAS_CONSTRUCTOR (t))
11571 return finish_compound_literal (type, r);
11578 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
11579 if (TYPE_P (operand_0))
11580 return get_typeid (operand_0);
11581 return build_typeid (operand_0);
11591 tree r = tsubst_copy (t, args, complain, in_decl);
11593 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
11594 /* If the original type was a reference, we'll be wrapped in
11595 the appropriate INDIRECT_REF. */
11596 r = convert_from_reference (r);
11601 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
11602 tsubst_copy (TREE_TYPE (t), args, complain,
11605 case OFFSETOF_EXPR:
11606 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
11610 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
11611 complain, in_decl);
11613 tree type2 = TRAIT_EXPR_TYPE2 (t);
11615 type2 = tsubst_copy (type2, args, complain, in_decl);
11617 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
11622 tree old_stmt_expr = cur_stmt_expr;
11623 tree stmt_expr = begin_stmt_expr ();
11625 cur_stmt_expr = stmt_expr;
11626 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
11627 integral_constant_expression_p);
11628 stmt_expr = finish_stmt_expr (stmt_expr, false);
11629 cur_stmt_expr = old_stmt_expr;
11635 t = tsubst_copy (t, args, complain, in_decl);
11636 /* As in finish_id_expression, we resolve enumeration constants
11637 to their underlying values. */
11638 if (TREE_CODE (t) == CONST_DECL)
11640 used_types_insert (TREE_TYPE (t));
11641 return DECL_INITIAL (t);
11646 /* Handle Objective-C++ constructs, if appropriate. */
11649 = objcp_tsubst_copy_and_build (t, args, complain,
11650 in_decl, /*function_p=*/false);
11654 return tsubst_copy (t, args, complain, in_decl);
11660 /* Verify that the instantiated ARGS are valid. For type arguments,
11661 make sure that the type's linkage is ok. For non-type arguments,
11662 make sure they are constants if they are integral or enumerations.
11663 Emit an error under control of COMPLAIN, and return TRUE on error. */
11666 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
11668 int ix, len = DECL_NTPARMS (tmpl);
11669 bool result = false;
11671 for (ix = 0; ix != len; ix++)
11673 tree t = TREE_VEC_ELT (args, ix);
11677 /* [basic.link]: A name with no linkage (notably, the name
11678 of a class or enumeration declared in a local scope)
11679 shall not be used to declare an entity with linkage.
11680 This implies that names with no linkage cannot be used as
11681 template arguments. */
11682 tree nt = no_linkage_check (t, /*relaxed_p=*/false);
11686 /* DR 488 makes use of a type with no linkage cause
11687 type deduction to fail. */
11688 if (complain & tf_error)
11690 if (TYPE_ANONYMOUS_P (nt))
11691 error ("%qT is/uses anonymous type", t);
11693 error ("template argument for %qD uses local type %qT",
11698 /* In order to avoid all sorts of complications, we do not
11699 allow variably-modified types as template arguments. */
11700 else if (variably_modified_type_p (t, NULL_TREE))
11702 if (complain & tf_error)
11703 error ("%qT is a variably modified type", t);
11707 /* A non-type argument of integral or enumerated type must be a
11709 else if (TREE_TYPE (t)
11710 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
11711 && !TREE_CONSTANT (t))
11713 if (complain & tf_error)
11714 error ("integral expression %qE is not constant", t);
11718 if (result && (complain & tf_error))
11719 error (" trying to instantiate %qD", tmpl);
11723 /* Instantiate the indicated variable or function template TMPL with
11724 the template arguments in TARG_PTR. */
11727 instantiate_template (tree tmpl, tree targ_ptr, tsubst_flags_t complain)
11732 HOST_WIDE_INT saved_processing_template_decl;
11734 if (tmpl == error_mark_node)
11735 return error_mark_node;
11737 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
11739 /* If this function is a clone, handle it specially. */
11740 if (DECL_CLONED_FUNCTION_P (tmpl))
11745 spec = instantiate_template (DECL_CLONED_FUNCTION (tmpl), targ_ptr,
11747 if (spec == error_mark_node)
11748 return error_mark_node;
11750 /* Look for the clone. */
11751 FOR_EACH_CLONE (clone, spec)
11752 if (DECL_NAME (clone) == DECL_NAME (tmpl))
11754 /* We should always have found the clone by now. */
11755 gcc_unreachable ();
11759 /* Check to see if we already have this specialization. */
11760 spec = retrieve_specialization (tmpl, targ_ptr,
11761 /*class_specializations_p=*/false);
11762 if (spec != NULL_TREE)
11765 gen_tmpl = most_general_template (tmpl);
11766 if (tmpl != gen_tmpl)
11768 /* The TMPL is a partial instantiation. To get a full set of
11769 arguments we must add the arguments used to perform the
11770 partial instantiation. */
11771 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
11774 /* Check to see if we already have this specialization. */
11775 spec = retrieve_specialization (gen_tmpl, targ_ptr,
11776 /*class_specializations_p=*/false);
11777 if (spec != NULL_TREE)
11781 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
11783 return error_mark_node;
11785 /* We are building a FUNCTION_DECL, during which the access of its
11786 parameters and return types have to be checked. However this
11787 FUNCTION_DECL which is the desired context for access checking
11788 is not built yet. We solve this chicken-and-egg problem by
11789 deferring all checks until we have the FUNCTION_DECL. */
11790 push_deferring_access_checks (dk_deferred);
11792 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
11793 (because, for example, we have encountered a non-dependent
11794 function call in the body of a template function and must now
11795 determine which of several overloaded functions will be called),
11796 within the instantiation itself we are not processing a
11798 saved_processing_template_decl = processing_template_decl;
11799 processing_template_decl = 0;
11800 /* Substitute template parameters to obtain the specialization. */
11801 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
11802 targ_ptr, complain, gen_tmpl);
11803 processing_template_decl = saved_processing_template_decl;
11804 if (fndecl == error_mark_node)
11805 return error_mark_node;
11807 /* Now we know the specialization, compute access previously
11809 push_access_scope (fndecl);
11810 perform_deferred_access_checks ();
11811 pop_access_scope (fndecl);
11812 pop_deferring_access_checks ();
11814 /* The DECL_TI_TEMPLATE should always be the immediate parent
11815 template, not the most general template. */
11816 DECL_TI_TEMPLATE (fndecl) = tmpl;
11818 /* If we've just instantiated the main entry point for a function,
11819 instantiate all the alternate entry points as well. We do this
11820 by cloning the instantiation of the main entry point, not by
11821 instantiating the template clones. */
11822 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
11823 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
11828 /* The FN is a TEMPLATE_DECL for a function. The ARGS are the
11829 arguments that are being used when calling it. TARGS is a vector
11830 into which the deduced template arguments are placed.
11832 Return zero for success, 2 for an incomplete match that doesn't resolve
11833 all the types, and 1 for complete failure. An error message will be
11834 printed only for an incomplete match.
11836 If FN is a conversion operator, or we are trying to produce a specific
11837 specialization, RETURN_TYPE is the return type desired.
11839 The EXPLICIT_TARGS are explicit template arguments provided via a
11842 The parameter STRICT is one of:
11845 We are deducing arguments for a function call, as in
11846 [temp.deduct.call].
11849 We are deducing arguments for a conversion function, as in
11850 [temp.deduct.conv].
11853 We are deducing arguments when doing an explicit instantiation
11854 as in [temp.explicit], when determining an explicit specialization
11855 as in [temp.expl.spec], or when taking the address of a function
11856 template, as in [temp.deduct.funcaddr]. */
11859 fn_type_unification (tree fn,
11860 tree explicit_targs,
11864 unification_kind_t strict,
11870 bool incomplete_argument_packs_p = false;
11872 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
11874 fntype = TREE_TYPE (fn);
11875 if (explicit_targs)
11879 The specified template arguments must match the template
11880 parameters in kind (i.e., type, nontype, template), and there
11881 must not be more arguments than there are parameters;
11882 otherwise type deduction fails.
11884 Nontype arguments must match the types of the corresponding
11885 nontype template parameters, or must be convertible to the
11886 types of the corresponding nontype parameters as specified in
11887 _temp.arg.nontype_, otherwise type deduction fails.
11889 All references in the function type of the function template
11890 to the corresponding template parameters are replaced by the
11891 specified template argument values. If a substitution in a
11892 template parameter or in the function type of the function
11893 template results in an invalid type, type deduction fails. */
11894 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
11895 int i, len = TREE_VEC_LENGTH (tparms);
11896 tree converted_args;
11897 bool incomplete = false;
11899 if (explicit_targs == error_mark_node)
11903 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
11904 /*require_all_args=*/false,
11905 /*use_default_args=*/false));
11906 if (converted_args == error_mark_node)
11909 /* Substitute the explicit args into the function type. This is
11910 necessary so that, for instance, explicitly declared function
11911 arguments can match null pointed constants. If we were given
11912 an incomplete set of explicit args, we must not do semantic
11913 processing during substitution as we could create partial
11915 for (i = 0; i < len; i++)
11917 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
11918 bool parameter_pack = false;
11920 /* Dig out the actual parm. */
11921 if (TREE_CODE (parm) == TYPE_DECL
11922 || TREE_CODE (parm) == TEMPLATE_DECL)
11924 parm = TREE_TYPE (parm);
11925 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
11927 else if (TREE_CODE (parm) == PARM_DECL)
11929 parm = DECL_INITIAL (parm);
11930 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
11933 if (parameter_pack)
11937 template_parm_level_and_index (parm, &level, &idx);
11939 /* Mark the argument pack as "incomplete". We could
11940 still deduce more arguments during unification. */
11941 targ = TMPL_ARG (converted_args, level, idx);
11944 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
11945 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
11946 = ARGUMENT_PACK_ARGS (targ);
11949 /* We have some incomplete argument packs. */
11950 incomplete_argument_packs_p = true;
11954 if (incomplete_argument_packs_p)
11955 /* Any substitution is guaranteed to be incomplete if there
11956 are incomplete argument packs, because we can still deduce
11960 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
11962 processing_template_decl += incomplete;
11963 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
11964 processing_template_decl -= incomplete;
11966 if (fntype == error_mark_node)
11969 /* Place the explicitly specified arguments in TARGS. */
11970 for (i = NUM_TMPL_ARGS (converted_args); i--;)
11971 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
11974 /* Never do unification on the 'this' parameter. */
11975 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
11979 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
11980 args = tree_cons (NULL_TREE, return_type, args);
11983 /* We allow incomplete unification without an error message here
11984 because the standard doesn't seem to explicitly prohibit it. Our
11985 callers must be ready to deal with unification failures in any
11987 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
11988 targs, parms, args, /*subr=*/0,
11991 if (result == 0 && incomplete_argument_packs_p)
11993 int i, len = NUM_TMPL_ARGS (targs);
11995 /* Clear the "incomplete" flags on all argument packs. */
11996 for (i = 0; i < len; i++)
11998 tree arg = TREE_VEC_ELT (targs, i);
11999 if (ARGUMENT_PACK_P (arg))
12001 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
12002 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
12007 /* Now that we have bindings for all of the template arguments,
12008 ensure that the arguments deduced for the template template
12009 parameters have compatible template parameter lists. We cannot
12010 check this property before we have deduced all template
12011 arguments, because the template parameter types of a template
12012 template parameter might depend on prior template parameters
12013 deduced after the template template parameter. The following
12014 ill-formed example illustrates this issue:
12016 template<typename T, template<T> class C> void f(C<5>, T);
12018 template<int N> struct X {};
12021 f(X<5>(), 5l); // error: template argument deduction fails
12024 The template parameter list of 'C' depends on the template type
12025 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
12026 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
12027 time that we deduce 'C'. */
12029 && !template_template_parm_bindings_ok_p
12030 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
12034 /* All is well so far. Now, check:
12038 When all template arguments have been deduced, all uses of
12039 template parameters in nondeduced contexts are replaced with
12040 the corresponding deduced argument values. If the
12041 substitution results in an invalid type, as described above,
12042 type deduction fails. */
12043 if (tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE)
12044 == error_mark_node)
12050 /* Adjust types before performing type deduction, as described in
12051 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
12052 sections are symmetric. PARM is the type of a function parameter
12053 or the return type of the conversion function. ARG is the type of
12054 the argument passed to the call, or the type of the value
12055 initialized with the result of the conversion function.
12056 ARG_EXPR is the original argument expression, which may be null. */
12059 maybe_adjust_types_for_deduction (unification_kind_t strict,
12073 /* Swap PARM and ARG throughout the remainder of this
12074 function; the handling is precisely symmetric since PARM
12075 will initialize ARG rather than vice versa. */
12083 /* There is nothing to do in this case. */
12087 gcc_unreachable ();
12090 if (TREE_CODE (*parm) != REFERENCE_TYPE)
12092 /* [temp.deduct.call]
12094 If P is not a reference type:
12096 --If A is an array type, the pointer type produced by the
12097 array-to-pointer standard conversion (_conv.array_) is
12098 used in place of A for type deduction; otherwise,
12100 --If A is a function type, the pointer type produced by
12101 the function-to-pointer standard conversion
12102 (_conv.func_) is used in place of A for type deduction;
12105 --If A is a cv-qualified type, the top level
12106 cv-qualifiers of A's type are ignored for type
12108 if (TREE_CODE (*arg) == ARRAY_TYPE)
12109 *arg = build_pointer_type (TREE_TYPE (*arg));
12110 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
12111 *arg = build_pointer_type (*arg);
12113 *arg = TYPE_MAIN_VARIANT (*arg);
12116 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
12117 of the form T&&, where T is a template parameter, and the argument
12118 is an lvalue, T is deduced as A& */
12119 if (TREE_CODE (*parm) == REFERENCE_TYPE
12120 && TYPE_REF_IS_RVALUE (*parm)
12121 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
12122 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
12123 && arg_expr && real_lvalue_p (arg_expr))
12124 *arg = build_reference_type (*arg);
12126 /* [temp.deduct.call]
12128 If P is a cv-qualified type, the top level cv-qualifiers
12129 of P's type are ignored for type deduction. If P is a
12130 reference type, the type referred to by P is used for
12132 *parm = TYPE_MAIN_VARIANT (*parm);
12133 if (TREE_CODE (*parm) == REFERENCE_TYPE)
12135 *parm = TREE_TYPE (*parm);
12136 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
12139 /* DR 322. For conversion deduction, remove a reference type on parm
12140 too (which has been swapped into ARG). */
12141 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
12142 *arg = TREE_TYPE (*arg);
12147 /* Most parms like fn_type_unification.
12149 If SUBR is 1, we're being called recursively (to unify the
12150 arguments of a function or method parameter of a function
12154 type_unification_real (tree tparms,
12159 unification_kind_t strict,
12162 tree parm, arg, arg_expr;
12164 int ntparms = TREE_VEC_LENGTH (tparms);
12166 int saw_undeduced = 0;
12169 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
12170 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
12171 gcc_assert (!xargs || TREE_CODE (xargs) == TREE_LIST);
12172 gcc_assert (ntparms > 0);
12177 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
12178 | UNIFY_ALLOW_DERIVED);
12182 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
12186 sub_strict = UNIFY_ALLOW_NONE;
12190 gcc_unreachable ();
12197 while (parms && parms != void_list_node
12198 && args && args != void_list_node)
12200 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
12203 parm = TREE_VALUE (parms);
12204 parms = TREE_CHAIN (parms);
12205 arg = TREE_VALUE (args);
12206 args = TREE_CHAIN (args);
12209 if (arg == error_mark_node)
12211 if (arg == unknown_type_node)
12212 /* We can't deduce anything from this, but we might get all the
12213 template args from other function args. */
12216 /* Conversions will be performed on a function argument that
12217 corresponds with a function parameter that contains only
12218 non-deducible template parameters and explicitly specified
12219 template parameters. */
12220 if (!uses_template_parms (parm))
12225 type = TREE_TYPE (arg);
12229 if (same_type_p (parm, type))
12231 if (strict != DEDUCE_EXACT
12232 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
12241 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
12242 if (type_unknown_p (arg))
12244 /* [temp.deduct.type]
12246 A template-argument can be deduced from a pointer to
12247 function or pointer to member function argument if
12248 the set of overloaded functions does not contain
12249 function templates and at most one of a set of
12250 overloaded functions provides a unique match. */
12251 if (resolve_overloaded_unification
12252 (tparms, targs, parm, arg, strict, sub_strict))
12258 arg = unlowered_expr_type (arg);
12259 if (arg == error_mark_node)
12264 int arg_strict = sub_strict;
12267 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
12270 if (arg == init_list_type_node && arg_expr)
12272 if (unify (tparms, targs, parm, arg, arg_strict))
12279 && parms != void_list_node
12280 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
12282 /* Unify the remaining arguments with the pack expansion type. */
12284 tree parmvec = make_tree_vec (1);
12288 /* Count the number of arguments that remain. */
12289 for (t = args; t && t != void_list_node; t = TREE_CHAIN (t))
12292 /* Allocate a TREE_VEC and copy in all of the arguments */
12293 argvec = make_tree_vec (len);
12294 for (i = 0; args && args != void_list_node; args = TREE_CHAIN (args))
12296 TREE_VEC_ELT (argvec, i) = TREE_VALUE (args);
12300 /* Copy the parameter into parmvec. */
12301 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
12302 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
12303 /*call_args_p=*/true, /*subr=*/subr))
12306 /* Advance to the end of the list of parameters. */
12307 parms = TREE_CHAIN (parms);
12310 /* Fail if we've reached the end of the parm list, and more args
12311 are present, and the parm list isn't variadic. */
12312 if (args && args != void_list_node && parms == void_list_node)
12314 /* Fail if parms are left and they don't have default values. */
12315 if (parms && parms != void_list_node
12316 && TREE_PURPOSE (parms) == NULL_TREE)
12320 for (i = 0; i < ntparms; i++)
12321 if (!TREE_VEC_ELT (targs, i))
12325 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
12328 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12330 /* If this is an undeduced nontype parameter that depends on
12331 a type parameter, try another pass; its type may have been
12332 deduced from a later argument than the one from which
12333 this parameter can be deduced. */
12334 if (TREE_CODE (tparm) == PARM_DECL
12335 && uses_template_parms (TREE_TYPE (tparm))
12336 && !saw_undeduced++)
12339 /* Core issue #226 (C++0x) [temp.deduct]:
12341 If a template argument has not been deduced, its
12342 default template argument, if any, is used.
12344 When we are in C++98 mode, TREE_PURPOSE will either
12345 be NULL_TREE or ERROR_MARK_NODE, so we do not need
12346 to explicitly check cxx_dialect here. */
12347 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
12349 tree arg = tsubst (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)),
12350 targs, tf_none, NULL_TREE);
12351 if (arg == error_mark_node)
12355 TREE_VEC_ELT (targs, i) = arg;
12360 /* If the type parameter is a parameter pack, then it will
12361 be deduced to an empty parameter pack. */
12362 if (template_parameter_pack_p (tparm))
12366 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
12368 arg = make_node (NONTYPE_ARGUMENT_PACK);
12369 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
12370 TREE_CONSTANT (arg) = 1;
12373 arg = make_node (TYPE_ARGUMENT_PACK);
12375 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
12377 TREE_VEC_ELT (targs, i) = arg;
12387 /* Subroutine of type_unification_real. Args are like the variables
12388 at the call site. ARG is an overloaded function (or template-id);
12389 we try deducing template args from each of the overloads, and if
12390 only one succeeds, we go with that. Modifies TARGS and returns
12391 true on success. */
12394 resolve_overloaded_unification (tree tparms,
12398 unification_kind_t strict,
12401 tree tempargs = copy_node (targs);
12405 if (TREE_CODE (arg) == ADDR_EXPR)
12407 arg = TREE_OPERAND (arg, 0);
12413 if (TREE_CODE (arg) == COMPONENT_REF)
12414 /* Handle `&x' where `x' is some static or non-static member
12416 arg = TREE_OPERAND (arg, 1);
12418 if (TREE_CODE (arg) == OFFSET_REF)
12419 arg = TREE_OPERAND (arg, 1);
12421 /* Strip baselink information. */
12422 if (BASELINK_P (arg))
12423 arg = BASELINK_FUNCTIONS (arg);
12425 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
12427 /* If we got some explicit template args, we need to plug them into
12428 the affected templates before we try to unify, in case the
12429 explicit args will completely resolve the templates in question. */
12431 tree expl_subargs = TREE_OPERAND (arg, 1);
12432 arg = TREE_OPERAND (arg, 0);
12434 for (; arg; arg = OVL_NEXT (arg))
12436 tree fn = OVL_CURRENT (arg);
12437 tree subargs, elem;
12439 if (TREE_CODE (fn) != TEMPLATE_DECL)
12442 ++processing_template_decl;
12443 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
12444 expl_subargs, /*check_ret=*/false);
12447 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
12448 good += try_one_overload (tparms, targs, tempargs, parm,
12449 elem, strict, sub_strict, addr_p);
12451 --processing_template_decl;
12454 else if (TREE_CODE (arg) != OVERLOAD
12455 && TREE_CODE (arg) != FUNCTION_DECL)
12456 /* If ARG is, for example, "(0, &f)" then its type will be unknown
12457 -- but the deduction does not succeed because the expression is
12458 not just the function on its own. */
12461 for (; arg; arg = OVL_NEXT (arg))
12462 good += try_one_overload (tparms, targs, tempargs, parm,
12463 TREE_TYPE (OVL_CURRENT (arg)),
12464 strict, sub_strict, addr_p);
12466 /* [temp.deduct.type] A template-argument can be deduced from a pointer
12467 to function or pointer to member function argument if the set of
12468 overloaded functions does not contain function templates and at most
12469 one of a set of overloaded functions provides a unique match.
12471 So if we found multiple possibilities, we return success but don't
12472 deduce anything. */
12476 int i = TREE_VEC_LENGTH (targs);
12478 if (TREE_VEC_ELT (tempargs, i))
12479 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
12487 /* Subroutine of resolve_overloaded_unification; does deduction for a single
12488 overload. Fills TARGS with any deduced arguments, or error_mark_node if
12489 different overloads deduce different arguments for a given parm.
12490 ADDR_P is true if the expression for which deduction is being
12491 performed was of the form "& fn" rather than simply "fn".
12493 Returns 1 on success. */
12496 try_one_overload (tree tparms,
12501 unification_kind_t strict,
12509 /* [temp.deduct.type] A template-argument can be deduced from a pointer
12510 to function or pointer to member function argument if the set of
12511 overloaded functions does not contain function templates and at most
12512 one of a set of overloaded functions provides a unique match.
12514 So if this is a template, just return success. */
12516 if (uses_template_parms (arg))
12519 if (TREE_CODE (arg) == METHOD_TYPE)
12520 arg = build_ptrmemfunc_type (build_pointer_type (arg));
12522 arg = build_pointer_type (arg);
12524 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
12526 /* We don't copy orig_targs for this because if we have already deduced
12527 some template args from previous args, unify would complain when we
12528 try to deduce a template parameter for the same argument, even though
12529 there isn't really a conflict. */
12530 nargs = TREE_VEC_LENGTH (targs);
12531 tempargs = make_tree_vec (nargs);
12533 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
12536 /* First make sure we didn't deduce anything that conflicts with
12537 explicitly specified args. */
12538 for (i = nargs; i--; )
12540 tree elt = TREE_VEC_ELT (tempargs, i);
12541 tree oldelt = TREE_VEC_ELT (orig_targs, i);
12545 else if (uses_template_parms (elt))
12546 /* Since we're unifying against ourselves, we will fill in
12547 template args used in the function parm list with our own
12548 template parms. Discard them. */
12549 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
12550 else if (oldelt && !template_args_equal (oldelt, elt))
12554 for (i = nargs; i--; )
12556 tree elt = TREE_VEC_ELT (tempargs, i);
12559 TREE_VEC_ELT (targs, i) = elt;
12565 /* PARM is a template class (perhaps with unbound template
12566 parameters). ARG is a fully instantiated type. If ARG can be
12567 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
12568 TARGS are as for unify. */
12571 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
12573 tree copy_of_targs;
12575 if (!CLASSTYPE_TEMPLATE_INFO (arg)
12576 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
12577 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
12580 /* We need to make a new template argument vector for the call to
12581 unify. If we used TARGS, we'd clutter it up with the result of
12582 the attempted unification, even if this class didn't work out.
12583 We also don't want to commit ourselves to all the unifications
12584 we've already done, since unification is supposed to be done on
12585 an argument-by-argument basis. In other words, consider the
12586 following pathological case:
12588 template <int I, int J, int K>
12591 template <int I, int J>
12592 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
12594 template <int I, int J, int K>
12595 void f(S<I, J, K>, S<I, I, I>);
12604 Now, by the time we consider the unification involving `s2', we
12605 already know that we must have `f<0, 0, 0>'. But, even though
12606 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
12607 because there are two ways to unify base classes of S<0, 1, 2>
12608 with S<I, I, I>. If we kept the already deduced knowledge, we
12609 would reject the possibility I=1. */
12610 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
12612 /* If unification failed, we're done. */
12613 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
12614 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
12620 /* Given a template type PARM and a class type ARG, find the unique
12621 base type in ARG that is an instance of PARM. We do not examine
12622 ARG itself; only its base-classes. If there is not exactly one
12623 appropriate base class, return NULL_TREE. PARM may be the type of
12624 a partial specialization, as well as a plain template type. Used
12628 get_template_base (tree tparms, tree targs, tree parm, tree arg)
12630 tree rval = NULL_TREE;
12633 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
12635 binfo = TYPE_BINFO (complete_type (arg));
12637 /* The type could not be completed. */
12640 /* Walk in inheritance graph order. The search order is not
12641 important, and this avoids multiple walks of virtual bases. */
12642 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
12644 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
12648 /* If there is more than one satisfactory baseclass, then:
12652 If they yield more than one possible deduced A, the type
12656 if (rval && !same_type_p (r, rval))
12666 /* Returns the level of DECL, which declares a template parameter. */
12669 template_decl_level (tree decl)
12671 switch (TREE_CODE (decl))
12674 case TEMPLATE_DECL:
12675 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
12678 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
12681 gcc_unreachable ();
12686 /* Decide whether ARG can be unified with PARM, considering only the
12687 cv-qualifiers of each type, given STRICT as documented for unify.
12688 Returns nonzero iff the unification is OK on that basis. */
12691 check_cv_quals_for_unify (int strict, tree arg, tree parm)
12693 int arg_quals = cp_type_quals (arg);
12694 int parm_quals = cp_type_quals (parm);
12696 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
12697 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
12699 /* Although a CVR qualifier is ignored when being applied to a
12700 substituted template parameter ([8.3.2]/1 for example), that
12701 does not apply during deduction [14.8.2.4]/1, (even though
12702 that is not explicitly mentioned, [14.8.2.4]/9 indicates
12703 this). Except when we're allowing additional CV qualifiers
12704 at the outer level [14.8.2.1]/3,1st bullet. */
12705 if ((TREE_CODE (arg) == REFERENCE_TYPE
12706 || TREE_CODE (arg) == FUNCTION_TYPE
12707 || TREE_CODE (arg) == METHOD_TYPE)
12708 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
12711 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
12712 && (parm_quals & TYPE_QUAL_RESTRICT))
12716 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
12717 && (arg_quals & parm_quals) != parm_quals)
12720 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
12721 && (parm_quals & arg_quals) != arg_quals)
12727 /* Determines the LEVEL and INDEX for the template parameter PARM. */
12729 template_parm_level_and_index (tree parm, int* level, int* index)
12731 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
12732 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
12733 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
12735 *index = TEMPLATE_TYPE_IDX (parm);
12736 *level = TEMPLATE_TYPE_LEVEL (parm);
12740 *index = TEMPLATE_PARM_IDX (parm);
12741 *level = TEMPLATE_PARM_LEVEL (parm);
12745 /* Unifies the remaining arguments in PACKED_ARGS with the pack
12746 expansion at the end of PACKED_PARMS. Returns 0 if the type
12747 deduction succeeds, 1 otherwise. STRICT is the same as in
12748 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
12749 call argument list. We'll need to adjust the arguments to make them
12750 types. SUBR tells us if this is from a recursive call to
12751 type_unification_real. */
12753 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
12754 tree packed_args, int strict, bool call_args_p,
12758 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
12759 tree pattern = PACK_EXPANSION_PATTERN (parm);
12760 tree pack, packs = NULL_TREE;
12761 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
12762 int len = TREE_VEC_LENGTH (packed_args);
12764 /* Determine the parameter packs we will be deducing from the
12765 pattern, and record their current deductions. */
12766 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
12767 pack; pack = TREE_CHAIN (pack))
12769 tree parm_pack = TREE_VALUE (pack);
12772 /* Determine the index and level of this parameter pack. */
12773 template_parm_level_and_index (parm_pack, &level, &idx);
12775 /* Keep track of the parameter packs and their corresponding
12777 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
12778 TREE_TYPE (packs) = make_tree_vec (len - start);
12781 /* Loop through all of the arguments that have not yet been
12782 unified and unify each with the pattern. */
12783 for (i = start; i < len; i++)
12785 tree parm = pattern;
12787 /* For each parameter pack, clear out the deduced value so that
12788 we can deduce it again. */
12789 for (pack = packs; pack; pack = TREE_CHAIN (pack))
12792 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
12794 TMPL_ARG (targs, level, idx) = NULL_TREE;
12797 /* Unify the pattern with the current argument. */
12799 tree arg = TREE_VEC_ELT (packed_args, i);
12800 tree arg_expr = NULL_TREE;
12801 int arg_strict = strict;
12802 bool skip_arg_p = false;
12808 /* This mirrors what we do in type_unification_real. */
12812 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
12813 | UNIFY_ALLOW_MORE_CV_QUAL
12814 | UNIFY_ALLOW_DERIVED);
12818 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
12822 sub_strict = UNIFY_ALLOW_NONE;
12826 gcc_unreachable ();
12831 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
12832 if (type_unknown_p (arg))
12834 /* [temp.deduct.type] A template-argument can be
12835 deduced from a pointer to function or pointer
12836 to member function argument if the set of
12837 overloaded functions does not contain function
12838 templates and at most one of a set of
12839 overloaded functions provides a unique
12842 if (resolve_overloaded_unification
12843 (tparms, targs, parm, arg, strict, sub_strict)
12852 arg = unlowered_expr_type (arg);
12853 if (arg == error_mark_node)
12858 arg_strict = sub_strict;
12862 maybe_adjust_types_for_deduction (strict, &parm, &arg,
12868 if (unify (tparms, targs, parm, arg, arg_strict))
12873 /* For each parameter pack, collect the deduced value. */
12874 for (pack = packs; pack; pack = TREE_CHAIN (pack))
12877 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
12879 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
12880 TMPL_ARG (targs, level, idx);
12884 /* Verify that the results of unification with the parameter packs
12885 produce results consistent with what we've seen before, and make
12886 the deduced argument packs available. */
12887 for (pack = packs; pack; pack = TREE_CHAIN (pack))
12889 tree old_pack = TREE_VALUE (pack);
12890 tree new_args = TREE_TYPE (pack);
12891 int i, len = TREE_VEC_LENGTH (new_args);
12892 bool nondeduced_p = false;
12894 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
12895 actually deduce anything. */
12896 for (i = 0; i < len && !nondeduced_p; ++i)
12897 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
12898 nondeduced_p = true;
12902 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
12904 /* Prepend the explicit arguments onto NEW_ARGS. */
12905 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
12906 tree old_args = new_args;
12907 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
12908 int len = explicit_len + TREE_VEC_LENGTH (old_args);
12910 /* Copy the explicit arguments. */
12911 new_args = make_tree_vec (len);
12912 for (i = 0; i < explicit_len; i++)
12913 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
12915 /* Copy the deduced arguments. */
12916 for (; i < len; i++)
12917 TREE_VEC_ELT (new_args, i) =
12918 TREE_VEC_ELT (old_args, i - explicit_len);
12926 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
12928 /* Build the deduced *_ARGUMENT_PACK. */
12929 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
12931 result = make_node (NONTYPE_ARGUMENT_PACK);
12932 TREE_TYPE (result) =
12933 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
12934 TREE_CONSTANT (result) = 1;
12937 result = make_node (TYPE_ARGUMENT_PACK);
12939 SET_ARGUMENT_PACK_ARGS (result, new_args);
12941 /* Note the deduced argument packs for this parameter
12943 TMPL_ARG (targs, level, idx) = result;
12945 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
12946 && (ARGUMENT_PACK_ARGS (old_pack)
12947 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
12949 /* We only had the explicitly-provided arguments before, but
12950 now we have a complete set of arguments. */
12952 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
12953 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
12955 /* Keep the original deduced argument pack. */
12956 TMPL_ARG (targs, level, idx) = old_pack;
12958 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
12959 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
12960 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
12962 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
12964 /* Inconsistent unification of this parameter pack. */
12970 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
12972 /* Keep the original deduced argument pack. */
12973 TMPL_ARG (targs, level, idx) = old_pack;
12980 /* Deduce the value of template parameters. TPARMS is the (innermost)
12981 set of template parameters to a template. TARGS is the bindings
12982 for those template parameters, as determined thus far; TARGS may
12983 include template arguments for outer levels of template parameters
12984 as well. PARM is a parameter to a template function, or a
12985 subcomponent of that parameter; ARG is the corresponding argument.
12986 This function attempts to match PARM with ARG in a manner
12987 consistent with the existing assignments in TARGS. If more values
12988 are deduced, then TARGS is updated.
12990 Returns 0 if the type deduction succeeds, 1 otherwise. The
12991 parameter STRICT is a bitwise or of the following flags:
12994 Require an exact match between PARM and ARG.
12995 UNIFY_ALLOW_MORE_CV_QUAL:
12996 Allow the deduced ARG to be more cv-qualified (by qualification
12997 conversion) than ARG.
12998 UNIFY_ALLOW_LESS_CV_QUAL:
12999 Allow the deduced ARG to be less cv-qualified than ARG.
13000 UNIFY_ALLOW_DERIVED:
13001 Allow the deduced ARG to be a template base class of ARG,
13002 or a pointer to a template base class of the type pointed to by
13004 UNIFY_ALLOW_INTEGER:
13005 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
13006 case for more information.
13007 UNIFY_ALLOW_OUTER_LEVEL:
13008 This is the outermost level of a deduction. Used to determine validity
13009 of qualification conversions. A valid qualification conversion must
13010 have const qualified pointers leading up to the inner type which
13011 requires additional CV quals, except at the outer level, where const
13012 is not required [conv.qual]. It would be normal to set this flag in
13013 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
13014 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
13015 This is the outermost level of a deduction, and PARM can be more CV
13016 qualified at this point.
13017 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
13018 This is the outermost level of a deduction, and PARM can be less CV
13019 qualified at this point. */
13022 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
13027 int strict_in = strict;
13029 /* I don't think this will do the right thing with respect to types.
13030 But the only case I've seen it in so far has been array bounds, where
13031 signedness is the only information lost, and I think that will be
13033 while (TREE_CODE (parm) == NOP_EXPR)
13034 parm = TREE_OPERAND (parm, 0);
13036 if (arg == error_mark_node)
13038 if (arg == unknown_type_node
13039 || arg == init_list_type_node)
13040 /* We can't deduce anything from this, but we might get all the
13041 template args from other function args. */
13044 /* If PARM uses template parameters, then we can't bail out here,
13045 even if ARG == PARM, since we won't record unifications for the
13046 template parameters. We might need them if we're trying to
13047 figure out which of two things is more specialized. */
13048 if (arg == parm && !uses_template_parms (parm))
13051 /* Handle init lists early, so the rest of the function can assume
13052 we're dealing with a type. */
13053 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
13058 if (!is_std_init_list (parm))
13059 /* We can only deduce from an initializer list argument if the
13060 parameter is std::initializer_list; otherwise this is a
13061 non-deduced context. */
13064 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
13066 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
13068 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
13069 elt = TREE_TYPE (elt);
13070 if (unify (tparms, targs, elttype, elt, UNIFY_ALLOW_NONE))
13076 /* Immediately reject some pairs that won't unify because of
13077 cv-qualification mismatches. */
13078 if (TREE_CODE (arg) == TREE_CODE (parm)
13080 /* It is the elements of the array which hold the cv quals of an array
13081 type, and the elements might be template type parms. We'll check
13082 when we recurse. */
13083 && TREE_CODE (arg) != ARRAY_TYPE
13084 /* We check the cv-qualifiers when unifying with template type
13085 parameters below. We want to allow ARG `const T' to unify with
13086 PARM `T' for example, when computing which of two templates
13087 is more specialized, for example. */
13088 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
13089 && !check_cv_quals_for_unify (strict_in, arg, parm))
13092 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
13093 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
13094 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
13095 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
13096 strict &= ~UNIFY_ALLOW_DERIVED;
13097 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13098 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
13100 switch (TREE_CODE (parm))
13102 case TYPENAME_TYPE:
13104 case UNBOUND_CLASS_TEMPLATE:
13105 /* In a type which contains a nested-name-specifier, template
13106 argument values cannot be deduced for template parameters used
13107 within the nested-name-specifier. */
13110 case TEMPLATE_TYPE_PARM:
13111 case TEMPLATE_TEMPLATE_PARM:
13112 case BOUND_TEMPLATE_TEMPLATE_PARM:
13113 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
13114 if (tparm == error_mark_node)
13117 if (TEMPLATE_TYPE_LEVEL (parm)
13118 != template_decl_level (tparm))
13119 /* The PARM is not one we're trying to unify. Just check
13120 to see if it matches ARG. */
13121 return (TREE_CODE (arg) == TREE_CODE (parm)
13122 && same_type_p (parm, arg)) ? 0 : 1;
13123 idx = TEMPLATE_TYPE_IDX (parm);
13124 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
13125 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
13127 /* Check for mixed types and values. */
13128 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13129 && TREE_CODE (tparm) != TYPE_DECL)
13130 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13131 && TREE_CODE (tparm) != TEMPLATE_DECL))
13134 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13136 /* ARG must be constructed from a template class or a template
13137 template parameter. */
13138 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
13139 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
13143 tree parmvec = TYPE_TI_ARGS (parm);
13144 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
13146 = DECL_INNERMOST_TEMPLATE_PARMS
13147 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
13149 int parm_variadic_p = 0;
13151 /* The resolution to DR150 makes clear that default
13152 arguments for an N-argument may not be used to bind T
13153 to a template template parameter with fewer than N
13154 parameters. It is not safe to permit the binding of
13155 default arguments as an extension, as that may change
13156 the meaning of a conforming program. Consider:
13158 struct Dense { static const unsigned int dim = 1; };
13160 template <template <typename> class View,
13162 void operator+(float, View<Block> const&);
13164 template <typename Block,
13165 unsigned int Dim = Block::dim>
13166 struct Lvalue_proxy { operator float() const; };
13170 Lvalue_proxy<Dense> p;
13175 Here, if Lvalue_proxy is permitted to bind to View, then
13176 the global operator+ will be used; if they are not, the
13177 Lvalue_proxy will be converted to float. */
13178 if (coerce_template_parms (parm_parms,
13180 TYPE_TI_TEMPLATE (parm),
13182 /*require_all_args=*/true,
13183 /*use_default_args=*/false)
13184 == error_mark_node)
13187 /* Deduce arguments T, i from TT<T> or TT<i>.
13188 We check each element of PARMVEC and ARGVEC individually
13189 rather than the whole TREE_VEC since they can have
13190 different number of elements. */
13192 parmvec = expand_template_argument_pack (parmvec);
13193 argvec = expand_template_argument_pack (argvec);
13195 len = TREE_VEC_LENGTH (parmvec);
13197 /* Check if the parameters end in a pack, making them
13200 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
13201 parm_variadic_p = 1;
13203 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
13206 for (i = 0; i < len - parm_variadic_p; ++i)
13208 if (unify (tparms, targs,
13209 TREE_VEC_ELT (parmvec, i),
13210 TREE_VEC_ELT (argvec, i),
13215 if (parm_variadic_p
13216 && unify_pack_expansion (tparms, targs,
13219 /*call_args_p=*/false,
13223 arg = TYPE_TI_TEMPLATE (arg);
13225 /* Fall through to deduce template name. */
13228 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13229 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13231 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
13233 /* Simple cases: Value already set, does match or doesn't. */
13234 if (targ != NULL_TREE && template_args_equal (targ, arg))
13241 /* If PARM is `const T' and ARG is only `int', we don't have
13242 a match unless we are allowing additional qualification.
13243 If ARG is `const int' and PARM is just `T' that's OK;
13244 that binds `const int' to `T'. */
13245 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
13249 /* Consider the case where ARG is `const volatile int' and
13250 PARM is `const T'. Then, T should be `volatile int'. */
13251 arg = cp_build_qualified_type_real
13252 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
13253 if (arg == error_mark_node)
13256 /* Simple cases: Value already set, does match or doesn't. */
13257 if (targ != NULL_TREE && same_type_p (targ, arg))
13262 /* Make sure that ARG is not a variable-sized array. (Note
13263 that were talking about variable-sized arrays (like
13264 `int[n]'), rather than arrays of unknown size (like
13265 `int[]').) We'll get very confused by such a type since
13266 the bound of the array will not be computable in an
13267 instantiation. Besides, such types are not allowed in
13268 ISO C++, so we can do as we please here. */
13269 if (variably_modified_type_p (arg, NULL_TREE))
13273 /* If ARG is a parameter pack or an expansion, we cannot unify
13274 against it unless PARM is also a parameter pack. */
13275 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
13276 && !template_parameter_pack_p (parm))
13279 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
13282 case TEMPLATE_PARM_INDEX:
13283 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
13284 if (tparm == error_mark_node)
13287 if (TEMPLATE_PARM_LEVEL (parm)
13288 != template_decl_level (tparm))
13289 /* The PARM is not one we're trying to unify. Just check
13290 to see if it matches ARG. */
13291 return !(TREE_CODE (arg) == TREE_CODE (parm)
13292 && cp_tree_equal (parm, arg));
13294 idx = TEMPLATE_PARM_IDX (parm);
13295 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
13298 return !cp_tree_equal (targ, arg);
13300 /* [temp.deduct.type] If, in the declaration of a function template
13301 with a non-type template-parameter, the non-type
13302 template-parameter is used in an expression in the function
13303 parameter-list and, if the corresponding template-argument is
13304 deduced, the template-argument type shall match the type of the
13305 template-parameter exactly, except that a template-argument
13306 deduced from an array bound may be of any integral type.
13307 The non-type parameter might use already deduced type parameters. */
13308 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
13309 if (!TREE_TYPE (arg))
13310 /* Template-parameter dependent expression. Just accept it for now.
13311 It will later be processed in convert_template_argument. */
13313 else if (same_type_p (TREE_TYPE (arg), tparm))
13315 else if ((strict & UNIFY_ALLOW_INTEGER)
13316 && (TREE_CODE (tparm) == INTEGER_TYPE
13317 || TREE_CODE (tparm) == BOOLEAN_TYPE))
13318 /* Convert the ARG to the type of PARM; the deduced non-type
13319 template argument must exactly match the types of the
13320 corresponding parameter. */
13321 arg = fold (build_nop (TREE_TYPE (parm), arg));
13322 else if (uses_template_parms (tparm))
13323 /* We haven't deduced the type of this parameter yet. Try again
13329 /* If ARG is a parameter pack or an expansion, we cannot unify
13330 against it unless PARM is also a parameter pack. */
13331 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
13332 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
13335 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
13340 /* A pointer-to-member constant can be unified only with
13341 another constant. */
13342 if (TREE_CODE (arg) != PTRMEM_CST)
13345 /* Just unify the class member. It would be useless (and possibly
13346 wrong, depending on the strict flags) to unify also
13347 PTRMEM_CST_CLASS, because we want to be sure that both parm and
13348 arg refer to the same variable, even if through different
13349 classes. For instance:
13351 struct A { int x; };
13354 Unification of &A::x and &B::x must succeed. */
13355 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
13356 PTRMEM_CST_MEMBER (arg), strict);
13361 if (TREE_CODE (arg) != POINTER_TYPE)
13364 /* [temp.deduct.call]
13366 A can be another pointer or pointer to member type that can
13367 be converted to the deduced A via a qualification
13368 conversion (_conv.qual_).
13370 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
13371 This will allow for additional cv-qualification of the
13372 pointed-to types if appropriate. */
13374 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
13375 /* The derived-to-base conversion only persists through one
13376 level of pointers. */
13377 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
13379 return unify (tparms, targs, TREE_TYPE (parm),
13380 TREE_TYPE (arg), strict);
13383 case REFERENCE_TYPE:
13384 if (TREE_CODE (arg) != REFERENCE_TYPE)
13386 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
13387 strict & UNIFY_ALLOW_MORE_CV_QUAL);
13390 if (TREE_CODE (arg) != ARRAY_TYPE)
13392 if ((TYPE_DOMAIN (parm) == NULL_TREE)
13393 != (TYPE_DOMAIN (arg) == NULL_TREE))
13395 if (TYPE_DOMAIN (parm) != NULL_TREE)
13402 /* Our representation of array types uses "N - 1" as the
13403 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
13404 not an integer constant. We cannot unify arbitrarily
13405 complex expressions, so we eliminate the MINUS_EXPRs
13407 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
13408 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
13411 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
13412 parm_max = TREE_OPERAND (parm_max, 0);
13414 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
13415 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
13418 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
13419 trying to unify the type of a variable with the type
13420 of a template parameter. For example:
13422 template <unsigned int N>
13423 void f (char (&) [N]);
13430 Here, the type of the ARG will be "int [g(i)]", and
13431 may be a SAVE_EXPR, etc. */
13432 if (TREE_CODE (arg_max) != MINUS_EXPR)
13434 arg_max = TREE_OPERAND (arg_max, 0);
13437 /* If only one of the bounds used a MINUS_EXPR, compensate
13438 by adding one to the other bound. */
13439 if (parm_cst && !arg_cst)
13440 parm_max = fold_build2 (PLUS_EXPR,
13444 else if (arg_cst && !parm_cst)
13445 arg_max = fold_build2 (PLUS_EXPR,
13450 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
13453 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
13454 strict & UNIFY_ALLOW_MORE_CV_QUAL);
13461 case ENUMERAL_TYPE:
13463 if (TREE_CODE (arg) != TREE_CODE (parm))
13466 /* We have already checked cv-qualification at the top of the
13468 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
13471 /* As far as unification is concerned, this wins. Later checks
13472 will invalidate it if necessary. */
13475 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
13476 /* Type INTEGER_CST can come from ordinary constant template args. */
13478 while (TREE_CODE (arg) == NOP_EXPR)
13479 arg = TREE_OPERAND (arg, 0);
13481 if (TREE_CODE (arg) != INTEGER_CST)
13483 return !tree_int_cst_equal (parm, arg);
13488 if (TREE_CODE (arg) != TREE_VEC)
13490 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
13492 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
13493 if (unify (tparms, targs,
13494 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
13502 if (TREE_CODE (arg) != TREE_CODE (parm))
13505 if (TYPE_PTRMEMFUNC_P (parm))
13507 if (!TYPE_PTRMEMFUNC_P (arg))
13510 return unify (tparms, targs,
13511 TYPE_PTRMEMFUNC_FN_TYPE (parm),
13512 TYPE_PTRMEMFUNC_FN_TYPE (arg),
13516 if (CLASSTYPE_TEMPLATE_INFO (parm))
13518 tree t = NULL_TREE;
13520 if (strict_in & UNIFY_ALLOW_DERIVED)
13522 /* First, we try to unify the PARM and ARG directly. */
13523 t = try_class_unification (tparms, targs,
13528 /* Fallback to the special case allowed in
13529 [temp.deduct.call]:
13531 If P is a class, and P has the form
13532 template-id, then A can be a derived class of
13533 the deduced A. Likewise, if P is a pointer to
13534 a class of the form template-id, A can be a
13535 pointer to a derived class pointed to by the
13537 t = get_template_base (tparms, targs, parm, arg);
13543 else if (CLASSTYPE_TEMPLATE_INFO (arg)
13544 && (CLASSTYPE_TI_TEMPLATE (parm)
13545 == CLASSTYPE_TI_TEMPLATE (arg)))
13546 /* Perhaps PARM is something like S<U> and ARG is S<int>.
13547 Then, we should unify `int' and `U'. */
13550 /* There's no chance of unification succeeding. */
13553 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
13554 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
13556 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
13561 case FUNCTION_TYPE:
13562 if (TREE_CODE (arg) != TREE_CODE (parm))
13565 /* CV qualifications for methods can never be deduced, they must
13566 match exactly. We need to check them explicitly here,
13567 because type_unification_real treats them as any other
13568 cv-qualified parameter. */
13569 if (TREE_CODE (parm) == METHOD_TYPE
13570 && (!check_cv_quals_for_unify
13572 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
13573 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
13576 if (unify (tparms, targs, TREE_TYPE (parm),
13577 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
13579 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
13580 TYPE_ARG_TYPES (arg), 1, DEDUCE_EXACT,
13584 /* Unify a pointer to member with a pointer to member function, which
13585 deduces the type of the member as a function type. */
13586 if (TYPE_PTRMEMFUNC_P (arg))
13590 cp_cv_quals cv_quals;
13592 /* Check top-level cv qualifiers */
13593 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
13596 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
13597 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
13600 /* Determine the type of the function we are unifying against. */
13601 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
13603 build_function_type (TREE_TYPE (method_type),
13604 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
13606 /* Extract the cv-qualifiers of the member function from the
13607 implicit object parameter and place them on the function
13608 type to be restored later. */
13610 cp_type_quals(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (method_type))));
13611 fntype = build_qualified_type (fntype, cv_quals);
13612 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
13615 if (TREE_CODE (arg) != OFFSET_TYPE)
13617 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
13618 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
13620 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
13624 if (DECL_TEMPLATE_PARM_P (parm))
13625 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
13626 if (arg != integral_constant_value (parm))
13631 case TEMPLATE_DECL:
13632 /* Matched cases are handled by the ARG == PARM test above. */
13635 case TYPE_ARGUMENT_PACK:
13636 case NONTYPE_ARGUMENT_PACK:
13638 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
13639 tree packed_args = ARGUMENT_PACK_ARGS (arg);
13640 int i, len = TREE_VEC_LENGTH (packed_parms);
13641 int argslen = TREE_VEC_LENGTH (packed_args);
13642 int parm_variadic_p = 0;
13644 for (i = 0; i < len; ++i)
13646 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
13649 /* We can unify against something with a trailing
13651 parm_variadic_p = 1;
13653 /* Since there is something following the pack
13654 expansion, we cannot unify this template argument
13661 /* If we don't have enough arguments to satisfy the parameters
13662 (not counting the pack expression at the end), or we have
13663 too many arguments for a parameter list that doesn't end in
13664 a pack expression, we can't unify. */
13665 if (argslen < (len - parm_variadic_p)
13666 || (argslen > len && !parm_variadic_p))
13669 /* Unify all of the parameters that precede the (optional)
13670 pack expression. */
13671 for (i = 0; i < len - parm_variadic_p; ++i)
13673 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
13674 TREE_VEC_ELT (packed_args, i), strict))
13678 if (parm_variadic_p)
13679 return unify_pack_expansion (tparms, targs,
13680 packed_parms, packed_args,
13681 strict, /*call_args_p=*/false,
13689 case DECLTYPE_TYPE:
13690 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
13695 /* Unification fails if we hit an error node. */
13699 gcc_assert (EXPR_P (parm));
13701 /* We must be looking at an expression. This can happen with
13705 void foo(S<I>, S<I + 2>);
13707 This is a "nondeduced context":
13711 The nondeduced contexts are:
13713 --A type that is a template-id in which one or more of
13714 the template-arguments is an expression that references
13715 a template-parameter.
13717 In these cases, we assume deduction succeeded, but don't
13718 actually infer any unifications. */
13720 if (!uses_template_parms (parm)
13721 && !template_args_equal (parm, arg))
13728 /* Note that DECL can be defined in this translation unit, if
13732 mark_definable (tree decl)
13735 DECL_NOT_REALLY_EXTERN (decl) = 1;
13736 FOR_EACH_CLONE (clone, decl)
13737 DECL_NOT_REALLY_EXTERN (clone) = 1;
13740 /* Called if RESULT is explicitly instantiated, or is a member of an
13741 explicitly instantiated class. */
13744 mark_decl_instantiated (tree result, int extern_p)
13746 SET_DECL_EXPLICIT_INSTANTIATION (result);
13748 /* If this entity has already been written out, it's too late to
13749 make any modifications. */
13750 if (TREE_ASM_WRITTEN (result))
13753 if (TREE_CODE (result) != FUNCTION_DECL)
13754 /* The TREE_PUBLIC flag for function declarations will have been
13755 set correctly by tsubst. */
13756 TREE_PUBLIC (result) = 1;
13758 /* This might have been set by an earlier implicit instantiation. */
13759 DECL_COMDAT (result) = 0;
13762 DECL_NOT_REALLY_EXTERN (result) = 0;
13765 mark_definable (result);
13766 /* Always make artificials weak. */
13767 if (DECL_ARTIFICIAL (result) && flag_weak)
13768 comdat_linkage (result);
13769 /* For WIN32 we also want to put explicit instantiations in
13770 linkonce sections. */
13771 else if (TREE_PUBLIC (result))
13772 maybe_make_one_only (result);
13775 /* If EXTERN_P, then this function will not be emitted -- unless
13776 followed by an explicit instantiation, at which point its linkage
13777 will be adjusted. If !EXTERN_P, then this function will be
13778 emitted here. In neither circumstance do we want
13779 import_export_decl to adjust the linkage. */
13780 DECL_INTERFACE_KNOWN (result) = 1;
13783 /* Given two function templates PAT1 and PAT2, return:
13785 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
13786 -1 if PAT2 is more specialized than PAT1.
13787 0 if neither is more specialized.
13789 LEN indicates the number of parameters we should consider
13790 (defaulted parameters should not be considered).
13792 The 1998 std underspecified function template partial ordering, and
13793 DR214 addresses the issue. We take pairs of arguments, one from
13794 each of the templates, and deduce them against each other. One of
13795 the templates will be more specialized if all the *other*
13796 template's arguments deduce against its arguments and at least one
13797 of its arguments *does* *not* deduce against the other template's
13798 corresponding argument. Deduction is done as for class templates.
13799 The arguments used in deduction have reference and top level cv
13800 qualifiers removed. Iff both arguments were originally reference
13801 types *and* deduction succeeds in both directions, the template
13802 with the more cv-qualified argument wins for that pairing (if
13803 neither is more cv-qualified, they both are equal). Unlike regular
13804 deduction, after all the arguments have been deduced in this way,
13805 we do *not* verify the deduced template argument values can be
13806 substituted into non-deduced contexts, nor do we have to verify
13807 that all template arguments have been deduced. */
13810 more_specialized_fn (tree pat1, tree pat2, int len)
13812 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
13813 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
13814 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
13815 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
13816 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
13817 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
13818 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
13819 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
13823 /* Remove the this parameter from non-static member functions. If
13824 one is a non-static member function and the other is not a static
13825 member function, remove the first parameter from that function
13826 also. This situation occurs for operator functions where we
13827 locate both a member function (with this pointer) and non-member
13828 operator (with explicit first operand). */
13829 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
13831 len--; /* LEN is the number of significant arguments for DECL1 */
13832 args1 = TREE_CHAIN (args1);
13833 if (!DECL_STATIC_FUNCTION_P (decl2))
13834 args2 = TREE_CHAIN (args2);
13836 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
13838 args2 = TREE_CHAIN (args2);
13839 if (!DECL_STATIC_FUNCTION_P (decl1))
13842 args1 = TREE_CHAIN (args1);
13846 /* If only one is a conversion operator, they are unordered. */
13847 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
13850 /* Consider the return type for a conversion function */
13851 if (DECL_CONV_FN_P (decl1))
13853 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
13854 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
13858 processing_template_decl++;
13861 /* Stop when an ellipsis is seen. */
13862 && args1 != NULL_TREE && args2 != NULL_TREE)
13864 tree arg1 = TREE_VALUE (args1);
13865 tree arg2 = TREE_VALUE (args2);
13866 int deduce1, deduce2;
13870 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
13871 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
13873 /* When both arguments are pack expansions, we need only
13874 unify the patterns themselves. */
13875 arg1 = PACK_EXPANSION_PATTERN (arg1);
13876 arg2 = PACK_EXPANSION_PATTERN (arg2);
13878 /* This is the last comparison we need to do. */
13882 if (TREE_CODE (arg1) == REFERENCE_TYPE)
13884 arg1 = TREE_TYPE (arg1);
13885 quals1 = cp_type_quals (arg1);
13888 if (TREE_CODE (arg2) == REFERENCE_TYPE)
13890 arg2 = TREE_TYPE (arg2);
13891 quals2 = cp_type_quals (arg2);
13894 if ((quals1 < 0) != (quals2 < 0))
13896 /* Only of the args is a reference, see if we should apply
13897 array/function pointer decay to it. This is not part of
13898 DR214, but is, IMHO, consistent with the deduction rules
13899 for the function call itself, and with our earlier
13900 implementation of the underspecified partial ordering
13901 rules. (nathan). */
13904 switch (TREE_CODE (arg1))
13907 arg1 = TREE_TYPE (arg1);
13909 case FUNCTION_TYPE:
13910 arg1 = build_pointer_type (arg1);
13919 switch (TREE_CODE (arg2))
13922 arg2 = TREE_TYPE (arg2);
13924 case FUNCTION_TYPE:
13925 arg2 = build_pointer_type (arg2);
13934 arg1 = TYPE_MAIN_VARIANT (arg1);
13935 arg2 = TYPE_MAIN_VARIANT (arg2);
13937 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
13939 int i, len2 = list_length (args2);
13940 tree parmvec = make_tree_vec (1);
13941 tree argvec = make_tree_vec (len2);
13944 /* Setup the parameter vector, which contains only ARG1. */
13945 TREE_VEC_ELT (parmvec, 0) = arg1;
13947 /* Setup the argument vector, which contains the remaining
13949 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
13950 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
13952 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
13953 argvec, UNIFY_ALLOW_NONE,
13954 /*call_args_p=*/false,
13957 /* We cannot deduce in the other direction, because ARG1 is
13958 a pack expansion but ARG2 is not. */
13961 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
13963 int i, len1 = list_length (args1);
13964 tree parmvec = make_tree_vec (1);
13965 tree argvec = make_tree_vec (len1);
13968 /* Setup the parameter vector, which contains only ARG1. */
13969 TREE_VEC_ELT (parmvec, 0) = arg2;
13971 /* Setup the argument vector, which contains the remaining
13973 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
13974 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
13976 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
13977 argvec, UNIFY_ALLOW_NONE,
13978 /*call_args_p=*/false,
13981 /* We cannot deduce in the other direction, because ARG2 is
13982 a pack expansion but ARG1 is not.*/
13988 /* The normal case, where neither argument is a pack
13990 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
13991 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
13998 if (better1 < 0 && better2 < 0)
13999 /* We've failed to deduce something in either direction.
14000 These must be unordered. */
14003 if (deduce1 && deduce2 && quals1 >= 0 && quals2 >= 0)
14005 /* Deduces in both directions, see if quals can
14006 disambiguate. Pretend the worse one failed to deduce. */
14007 if ((quals1 & quals2) == quals2)
14009 if ((quals1 & quals2) == quals1)
14012 if (deduce1 && !deduce2 && !better2)
14014 if (deduce2 && !deduce1 && !better1)
14017 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
14018 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14019 /* We have already processed all of the arguments in our
14020 handing of the pack expansion type. */
14023 args1 = TREE_CHAIN (args1);
14024 args2 = TREE_CHAIN (args2);
14027 processing_template_decl--;
14029 /* All things being equal, if the next argument is a pack expansion
14030 for one function but not for the other, prefer the
14031 non-variadic function. */
14032 if ((better1 > 0) - (better2 > 0) == 0
14033 && args1 && TREE_VALUE (args1)
14034 && args2 && TREE_VALUE (args2))
14036 if (TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION)
14037 return TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION ? 0 : -1;
14038 else if (TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION)
14042 return (better1 > 0) - (better2 > 0);
14045 /* Determine which of two partial specializations is more specialized.
14047 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
14048 to the first partial specialization. The TREE_VALUE is the
14049 innermost set of template parameters for the partial
14050 specialization. PAT2 is similar, but for the second template.
14052 Return 1 if the first partial specialization is more specialized;
14053 -1 if the second is more specialized; 0 if neither is more
14056 See [temp.class.order] for information about determining which of
14057 two templates is more specialized. */
14060 more_specialized_class (tree pat1, tree pat2)
14065 bool any_deductions = false;
14067 tmpl1 = TREE_TYPE (pat1);
14068 tmpl2 = TREE_TYPE (pat2);
14070 /* Just like what happens for functions, if we are ordering between
14071 different class template specializations, we may encounter dependent
14072 types in the arguments, and we need our dependency check functions
14073 to behave correctly. */
14074 ++processing_template_decl;
14075 targs = get_class_bindings (TREE_VALUE (pat1),
14076 CLASSTYPE_TI_ARGS (tmpl1),
14077 CLASSTYPE_TI_ARGS (tmpl2));
14081 any_deductions = true;
14084 targs = get_class_bindings (TREE_VALUE (pat2),
14085 CLASSTYPE_TI_ARGS (tmpl2),
14086 CLASSTYPE_TI_ARGS (tmpl1));
14090 any_deductions = true;
14092 --processing_template_decl;
14094 /* In the case of a tie where at least one of the class templates
14095 has a parameter pack at the end, the template with the most
14096 non-packed parameters wins. */
14099 && (template_args_variadic_p (TREE_PURPOSE (pat1))
14100 || template_args_variadic_p (TREE_PURPOSE (pat2))))
14102 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
14103 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
14104 int len1 = TREE_VEC_LENGTH (args1);
14105 int len2 = TREE_VEC_LENGTH (args2);
14107 /* We don't count the pack expansion at the end. */
14108 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
14110 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
14115 else if (len1 < len2)
14122 /* Return the template arguments that will produce the function signature
14123 DECL from the function template FN, with the explicit template
14124 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
14125 also match. Return NULL_TREE if no satisfactory arguments could be
14129 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
14131 int ntparms = DECL_NTPARMS (fn);
14132 tree targs = make_tree_vec (ntparms);
14134 tree decl_arg_types;
14136 /* Substitute the explicit template arguments into the type of DECL.
14137 The call to fn_type_unification will handle substitution into the
14139 decl_type = TREE_TYPE (decl);
14140 if (explicit_args && uses_template_parms (decl_type))
14143 tree converted_args;
14145 if (DECL_TEMPLATE_INFO (decl))
14146 tmpl = DECL_TI_TEMPLATE (decl);
14148 /* We can get here for some invalid specializations. */
14152 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
14153 explicit_args, NULL_TREE,
14155 /*require_all_args=*/false,
14156 /*use_default_args=*/false);
14157 if (converted_args == error_mark_node)
14160 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
14161 if (decl_type == error_mark_node)
14165 /* Never do unification on the 'this' parameter. */
14166 decl_arg_types = skip_artificial_parms_for (decl,
14167 TYPE_ARG_TYPES (decl_type));
14169 if (fn_type_unification (fn, explicit_args, targs,
14171 (check_rettype || DECL_CONV_FN_P (fn)
14172 ? TREE_TYPE (decl_type) : NULL_TREE),
14173 DEDUCE_EXACT, LOOKUP_NORMAL))
14179 /* Return the innermost template arguments that, when applied to a
14180 template specialization whose innermost template parameters are
14181 TPARMS, and whose specialization arguments are PARMS, yield the
14184 For example, suppose we have:
14186 template <class T, class U> struct S {};
14187 template <class T> struct S<T*, int> {};
14189 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
14190 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
14191 int}. The resulting vector will be {double}, indicating that `T'
14192 is bound to `double'. */
14195 get_class_bindings (tree tparms, tree spec_args, tree args)
14197 int i, ntparms = TREE_VEC_LENGTH (tparms);
14199 tree innermost_deduced_args;
14201 innermost_deduced_args = make_tree_vec (ntparms);
14202 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
14204 deduced_args = copy_node (args);
14205 SET_TMPL_ARGS_LEVEL (deduced_args,
14206 TMPL_ARGS_DEPTH (deduced_args),
14207 innermost_deduced_args);
14210 deduced_args = innermost_deduced_args;
14212 if (unify (tparms, deduced_args,
14213 INNERMOST_TEMPLATE_ARGS (spec_args),
14214 INNERMOST_TEMPLATE_ARGS (args),
14218 for (i = 0; i < ntparms; ++i)
14219 if (! TREE_VEC_ELT (innermost_deduced_args, i))
14222 /* Verify that nondeduced template arguments agree with the type
14223 obtained from argument deduction.
14227 struct A { typedef int X; };
14228 template <class T, class U> struct C {};
14229 template <class T> struct C<T, typename T::X> {};
14231 Then with the instantiation `C<A, int>', we can deduce that
14232 `T' is `A' but unify () does not check whether `typename T::X'
14234 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
14235 if (spec_args == error_mark_node
14236 /* We only need to check the innermost arguments; the other
14237 arguments will always agree. */
14238 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
14239 INNERMOST_TEMPLATE_ARGS (args)))
14242 /* Now that we have bindings for all of the template arguments,
14243 ensure that the arguments deduced for the template template
14244 parameters have compatible template parameter lists. See the use
14245 of template_template_parm_bindings_ok_p in fn_type_unification
14246 for more information. */
14247 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
14250 return deduced_args;
14253 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
14254 Return the TREE_LIST node with the most specialized template, if
14255 any. If there is no most specialized template, the error_mark_node
14258 Note that this function does not look at, or modify, the
14259 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
14260 returned is one of the elements of INSTANTIATIONS, callers may
14261 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
14262 and retrieve it from the value returned. */
14265 most_specialized_instantiation (tree templates)
14269 ++processing_template_decl;
14272 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
14276 if (get_bindings (TREE_VALUE (champ),
14277 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
14278 NULL_TREE, /*check_ret=*/false))
14281 if (get_bindings (TREE_VALUE (fn),
14282 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
14283 NULL_TREE, /*check_ret=*/false))
14290 /* Equally specialized, move to next function. If there
14291 is no next function, nothing's most specialized. */
14292 fn = TREE_CHAIN (fn);
14300 /* Now verify that champ is better than everything earlier in the
14301 instantiation list. */
14302 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
14303 if (get_bindings (TREE_VALUE (champ),
14304 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
14305 NULL_TREE, /*check_ret=*/false)
14306 || !get_bindings (TREE_VALUE (fn),
14307 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
14308 NULL_TREE, /*check_ret=*/false))
14314 processing_template_decl--;
14317 return error_mark_node;
14322 /* If DECL is a specialization of some template, return the most
14323 general such template. Otherwise, returns NULL_TREE.
14325 For example, given:
14327 template <class T> struct S { template <class U> void f(U); };
14329 if TMPL is `template <class U> void S<int>::f(U)' this will return
14330 the full template. This function will not trace past partial
14331 specializations, however. For example, given in addition:
14333 template <class T> struct S<T*> { template <class U> void f(U); };
14335 if TMPL is `template <class U> void S<int*>::f(U)' this will return
14336 `template <class T> template <class U> S<T*>::f(U)'. */
14339 most_general_template (tree decl)
14341 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
14342 an immediate specialization. */
14343 if (TREE_CODE (decl) == FUNCTION_DECL)
14345 if (DECL_TEMPLATE_INFO (decl)) {
14346 decl = DECL_TI_TEMPLATE (decl);
14348 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
14349 template friend. */
14350 if (TREE_CODE (decl) != TEMPLATE_DECL)
14356 /* Look for more and more general templates. */
14357 while (DECL_TEMPLATE_INFO (decl))
14359 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
14360 (See cp-tree.h for details.) */
14361 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
14364 if (CLASS_TYPE_P (TREE_TYPE (decl))
14365 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
14368 /* Stop if we run into an explicitly specialized class template. */
14369 if (!DECL_NAMESPACE_SCOPE_P (decl)
14370 && DECL_CONTEXT (decl)
14371 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
14374 decl = DECL_TI_TEMPLATE (decl);
14380 /* Return the most specialized of the class template partial
14381 specializations of TMPL which can produce TYPE, a specialization of
14382 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
14383 a _TYPE node corresponding to the partial specialization, while the
14384 TREE_PURPOSE is the set of template arguments that must be
14385 substituted into the TREE_TYPE in order to generate TYPE.
14387 If the choice of partial specialization is ambiguous, a diagnostic
14388 is issued, and the error_mark_node is returned. If there are no
14389 partial specializations of TMPL matching TYPE, then NULL_TREE is
14393 most_specialized_class (tree type, tree tmpl)
14395 tree list = NULL_TREE;
14401 tree outer_args = NULL_TREE;
14403 tmpl = most_general_template (tmpl);
14404 args = CLASSTYPE_TI_ARGS (type);
14406 /* For determining which partial specialization to use, only the
14407 innermost args are interesting. */
14408 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
14410 outer_args = strip_innermost_template_args (args, 1);
14411 args = INNERMOST_TEMPLATE_ARGS (args);
14414 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
14416 tree partial_spec_args;
14418 tree parms = TREE_VALUE (t);
14420 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
14425 ++processing_template_decl;
14427 /* Discard the outer levels of args, and then substitute in the
14428 template args from the enclosing class. */
14429 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
14430 partial_spec_args = tsubst_template_args
14431 (partial_spec_args, outer_args, tf_none, NULL_TREE);
14433 /* PARMS already refers to just the innermost parms, but the
14434 template parms in partial_spec_args had their levels lowered
14435 by tsubst, so we need to do the same for the parm list. We
14436 can't just tsubst the TREE_VEC itself, as tsubst wants to
14437 treat a TREE_VEC as an argument vector. */
14438 parms = copy_node (parms);
14439 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
14440 TREE_VEC_ELT (parms, i) =
14441 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
14443 --processing_template_decl;
14445 spec_args = get_class_bindings (parms,
14451 spec_args = add_to_template_args (outer_args, spec_args);
14452 list = tree_cons (spec_args, TREE_VALUE (t), list);
14453 TREE_TYPE (list) = TREE_TYPE (t);
14460 ambiguous_p = false;
14463 t = TREE_CHAIN (t);
14464 for (; t; t = TREE_CHAIN (t))
14466 fate = more_specialized_class (champ, t);
14473 t = TREE_CHAIN (t);
14476 ambiguous_p = true;
14485 for (t = list; t && t != champ; t = TREE_CHAIN (t))
14487 fate = more_specialized_class (champ, t);
14490 ambiguous_p = true;
14497 const char *str = "candidates are:";
14498 error ("ambiguous class template instantiation for %q#T", type);
14499 for (t = list; t; t = TREE_CHAIN (t))
14501 error ("%s %+#T", str, TREE_TYPE (t));
14504 return error_mark_node;
14510 /* Explicitly instantiate DECL. */
14513 do_decl_instantiation (tree decl, tree storage)
14515 tree result = NULL_TREE;
14518 if (!decl || decl == error_mark_node)
14519 /* An error occurred, for which grokdeclarator has already issued
14520 an appropriate message. */
14522 else if (! DECL_LANG_SPECIFIC (decl))
14524 error ("explicit instantiation of non-template %q#D", decl);
14527 else if (TREE_CODE (decl) == VAR_DECL)
14529 /* There is an asymmetry here in the way VAR_DECLs and
14530 FUNCTION_DECLs are handled by grokdeclarator. In the case of
14531 the latter, the DECL we get back will be marked as a
14532 template instantiation, and the appropriate
14533 DECL_TEMPLATE_INFO will be set up. This does not happen for
14534 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
14535 should handle VAR_DECLs as it currently handles
14537 if (!DECL_CLASS_SCOPE_P (decl))
14539 error ("%qD is not a static data member of a class template", decl);
14542 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
14543 if (!result || TREE_CODE (result) != VAR_DECL)
14545 error ("no matching template for %qD found", decl);
14548 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
14550 error ("type %qT for explicit instantiation %qD does not match "
14551 "declared type %qT", TREE_TYPE (result), decl,
14556 else if (TREE_CODE (decl) != FUNCTION_DECL)
14558 error ("explicit instantiation of %q#D", decl);
14564 /* Check for various error cases. Note that if the explicit
14565 instantiation is valid the RESULT will currently be marked as an
14566 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
14567 until we get here. */
14569 if (DECL_TEMPLATE_SPECIALIZATION (result))
14571 /* DR 259 [temp.spec].
14573 Both an explicit instantiation and a declaration of an explicit
14574 specialization shall not appear in a program unless the explicit
14575 instantiation follows a declaration of the explicit specialization.
14577 For a given set of template parameters, if an explicit
14578 instantiation of a template appears after a declaration of an
14579 explicit specialization for that template, the explicit
14580 instantiation has no effect. */
14583 else if (DECL_EXPLICIT_INSTANTIATION (result))
14587 No program shall explicitly instantiate any template more
14590 We check DECL_NOT_REALLY_EXTERN so as not to complain when
14591 the first instantiation was `extern' and the second is not,
14592 and EXTERN_P for the opposite case. */
14593 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
14594 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
14595 /* If an "extern" explicit instantiation follows an ordinary
14596 explicit instantiation, the template is instantiated. */
14600 else if (!DECL_IMPLICIT_INSTANTIATION (result))
14602 error ("no matching template for %qD found", result);
14605 else if (!DECL_TEMPLATE_INFO (result))
14607 permerror (input_location, "explicit instantiation of non-template %q#D", result);
14611 if (storage == NULL_TREE)
14613 else if (storage == ridpointers[(int) RID_EXTERN])
14615 if (!in_system_header && (cxx_dialect == cxx98))
14616 pedwarn (input_location, OPT_pedantic,
14617 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
14622 error ("storage class %qD applied to template instantiation", storage);
14624 check_explicit_instantiation_namespace (result);
14625 mark_decl_instantiated (result, extern_p);
14627 instantiate_decl (result, /*defer_ok=*/1,
14628 /*expl_inst_class_mem_p=*/false);
14632 mark_class_instantiated (tree t, int extern_p)
14634 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
14635 SET_CLASSTYPE_INTERFACE_KNOWN (t);
14636 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
14637 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
14640 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
14641 rest_of_type_compilation (t, 1);
14645 /* Called from do_type_instantiation through binding_table_foreach to
14646 do recursive instantiation for the type bound in ENTRY. */
14648 bt_instantiate_type_proc (binding_entry entry, void *data)
14650 tree storage = *(tree *) data;
14652 if (MAYBE_CLASS_TYPE_P (entry->type)
14653 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
14654 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
14657 /* Called from do_type_instantiation to instantiate a member
14658 (a member function or a static member variable) of an
14659 explicitly instantiated class template. */
14661 instantiate_class_member (tree decl, int extern_p)
14663 mark_decl_instantiated (decl, extern_p);
14665 instantiate_decl (decl, /*defer_ok=*/1,
14666 /*expl_inst_class_mem_p=*/true);
14669 /* Perform an explicit instantiation of template class T. STORAGE, if
14670 non-null, is the RID for extern, inline or static. COMPLAIN is
14671 nonzero if this is called from the parser, zero if called recursively,
14672 since the standard is unclear (as detailed below). */
14675 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
14680 int previous_instantiation_extern_p = 0;
14682 if (TREE_CODE (t) == TYPE_DECL)
14685 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
14687 error ("explicit instantiation of non-template type %qT", t);
14693 if (!COMPLETE_TYPE_P (t))
14695 if (complain & tf_error)
14696 error ("explicit instantiation of %q#T before definition of template",
14701 if (storage != NULL_TREE)
14703 if (!in_system_header)
14705 if (storage == ridpointers[(int) RID_EXTERN])
14707 if (cxx_dialect == cxx98)
14708 pedwarn (input_location, OPT_pedantic,
14709 "ISO C++ 1998 forbids the use of %<extern%> on "
14710 "explicit instantiations");
14713 pedwarn (input_location, OPT_pedantic,
14714 "ISO C++ forbids the use of %qE"
14715 " on explicit instantiations", storage);
14718 if (storage == ridpointers[(int) RID_INLINE])
14720 else if (storage == ridpointers[(int) RID_EXTERN])
14722 else if (storage == ridpointers[(int) RID_STATIC])
14726 error ("storage class %qD applied to template instantiation",
14732 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
14734 /* DR 259 [temp.spec].
14736 Both an explicit instantiation and a declaration of an explicit
14737 specialization shall not appear in a program unless the explicit
14738 instantiation follows a declaration of the explicit specialization.
14740 For a given set of template parameters, if an explicit
14741 instantiation of a template appears after a declaration of an
14742 explicit specialization for that template, the explicit
14743 instantiation has no effect. */
14746 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
14750 No program shall explicitly instantiate any template more
14753 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
14754 instantiation was `extern'. If EXTERN_P then the second is.
14755 These cases are OK. */
14756 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
14758 if (!previous_instantiation_extern_p && !extern_p
14759 && (complain & tf_error))
14760 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
14762 /* If we've already instantiated the template, just return now. */
14763 if (!CLASSTYPE_INTERFACE_ONLY (t))
14767 check_explicit_instantiation_namespace (TYPE_NAME (t));
14768 mark_class_instantiated (t, extern_p);
14776 /* In contrast to implicit instantiation, where only the
14777 declarations, and not the definitions, of members are
14778 instantiated, we have here:
14782 The explicit instantiation of a class template specialization
14783 implies the instantiation of all of its members not
14784 previously explicitly specialized in the translation unit
14785 containing the explicit instantiation.
14787 Of course, we can't instantiate member template classes, since
14788 we don't have any arguments for them. Note that the standard
14789 is unclear on whether the instantiation of the members are
14790 *explicit* instantiations or not. However, the most natural
14791 interpretation is that it should be an explicit instantiation. */
14794 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
14795 if (TREE_CODE (tmp) == FUNCTION_DECL
14796 && DECL_TEMPLATE_INSTANTIATION (tmp))
14797 instantiate_class_member (tmp, extern_p);
14799 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
14800 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
14801 instantiate_class_member (tmp, extern_p);
14803 if (CLASSTYPE_NESTED_UTDS (t))
14804 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
14805 bt_instantiate_type_proc, &storage);
14809 /* Given a function DECL, which is a specialization of TMPL, modify
14810 DECL to be a re-instantiation of TMPL with the same template
14811 arguments. TMPL should be the template into which tsubst'ing
14812 should occur for DECL, not the most general template.
14814 One reason for doing this is a scenario like this:
14817 void f(const T&, int i);
14819 void g() { f(3, 7); }
14822 void f(const T& t, const int i) { }
14824 Note that when the template is first instantiated, with
14825 instantiate_template, the resulting DECL will have no name for the
14826 first parameter, and the wrong type for the second. So, when we go
14827 to instantiate the DECL, we regenerate it. */
14830 regenerate_decl_from_template (tree decl, tree tmpl)
14832 /* The arguments used to instantiate DECL, from the most general
14837 args = DECL_TI_ARGS (decl);
14838 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
14840 /* Make sure that we can see identifiers, and compute access
14842 push_access_scope (decl);
14844 if (TREE_CODE (decl) == FUNCTION_DECL)
14852 args_depth = TMPL_ARGS_DEPTH (args);
14853 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
14854 if (args_depth > parms_depth)
14855 args = get_innermost_template_args (args, parms_depth);
14857 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
14858 args, tf_error, NULL_TREE);
14860 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
14863 /* Merge parameter declarations. */
14864 decl_parm = skip_artificial_parms_for (decl,
14865 DECL_ARGUMENTS (decl));
14867 = skip_artificial_parms_for (code_pattern,
14868 DECL_ARGUMENTS (code_pattern));
14869 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
14874 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
14875 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
14876 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
14878 parm_type = type_decays_to (parm_type);
14879 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
14880 TREE_TYPE (decl_parm) = parm_type;
14881 attributes = DECL_ATTRIBUTES (pattern_parm);
14882 if (DECL_ATTRIBUTES (decl_parm) != attributes)
14884 DECL_ATTRIBUTES (decl_parm) = attributes;
14885 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
14887 decl_parm = TREE_CHAIN (decl_parm);
14888 pattern_parm = TREE_CHAIN (pattern_parm);
14890 /* Merge any parameters that match with the function parameter
14892 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
14895 tree expanded_types;
14896 /* Expand the TYPE_PACK_EXPANSION that provides the types for
14897 the parameters in this function parameter pack. */
14898 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
14899 args, tf_error, NULL_TREE);
14900 len = TREE_VEC_LENGTH (expanded_types);
14901 for (i = 0; i < len; i++)
14906 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
14907 /* Rename the parameter to include the index. */
14908 DECL_NAME (decl_parm) =
14909 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
14910 parm_type = TREE_VEC_ELT (expanded_types, i);
14911 parm_type = type_decays_to (parm_type);
14912 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
14913 TREE_TYPE (decl_parm) = parm_type;
14914 attributes = DECL_ATTRIBUTES (pattern_parm);
14915 if (DECL_ATTRIBUTES (decl_parm) != attributes)
14917 DECL_ATTRIBUTES (decl_parm) = attributes;
14918 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
14920 decl_parm = TREE_CHAIN (decl_parm);
14923 /* Merge additional specifiers from the CODE_PATTERN. */
14924 if (DECL_DECLARED_INLINE_P (code_pattern)
14925 && !DECL_DECLARED_INLINE_P (decl))
14926 DECL_DECLARED_INLINE_P (decl) = 1;
14928 else if (TREE_CODE (decl) == VAR_DECL)
14929 DECL_INITIAL (decl) =
14930 tsubst_expr (DECL_INITIAL (code_pattern), args,
14931 tf_error, DECL_TI_TEMPLATE (decl),
14932 /*integral_constant_expression_p=*/false);
14934 gcc_unreachable ();
14936 pop_access_scope (decl);
14939 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
14940 substituted to get DECL. */
14943 template_for_substitution (tree decl)
14945 tree tmpl = DECL_TI_TEMPLATE (decl);
14947 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
14948 for the instantiation. This is not always the most general
14949 template. Consider, for example:
14952 struct S { template <class U> void f();
14953 template <> void f<int>(); };
14955 and an instantiation of S<double>::f<int>. We want TD to be the
14956 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
14957 while (/* An instantiation cannot have a definition, so we need a
14958 more general template. */
14959 DECL_TEMPLATE_INSTANTIATION (tmpl)
14960 /* We must also deal with friend templates. Given:
14962 template <class T> struct S {
14963 template <class U> friend void f() {};
14966 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
14967 so far as the language is concerned, but that's still
14968 where we get the pattern for the instantiation from. On
14969 other hand, if the definition comes outside the class, say:
14971 template <class T> struct S {
14972 template <class U> friend void f();
14974 template <class U> friend void f() {}
14976 we don't need to look any further. That's what the check for
14977 DECL_INITIAL is for. */
14978 || (TREE_CODE (decl) == FUNCTION_DECL
14979 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
14980 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
14982 /* The present template, TD, should not be a definition. If it
14983 were a definition, we should be using it! Note that we
14984 cannot restructure the loop to just keep going until we find
14985 a template with a definition, since that might go too far if
14986 a specialization was declared, but not defined. */
14987 gcc_assert (TREE_CODE (decl) != VAR_DECL
14988 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
14990 /* Fetch the more general template. */
14991 tmpl = DECL_TI_TEMPLATE (tmpl);
14997 /* Produce the definition of D, a _DECL generated from a template. If
14998 DEFER_OK is nonzero, then we don't have to actually do the
14999 instantiation now; we just have to do it sometime. Normally it is
15000 an error if this is an explicit instantiation but D is undefined.
15001 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
15002 explicitly instantiated class template. */
15005 instantiate_decl (tree d, int defer_ok,
15006 bool expl_inst_class_mem_p)
15008 tree tmpl = DECL_TI_TEMPLATE (d);
15015 bool pattern_defined;
15017 location_t saved_loc = input_location;
15020 /* This function should only be used to instantiate templates for
15021 functions and static member variables. */
15022 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
15023 || TREE_CODE (d) == VAR_DECL);
15025 /* Variables are never deferred; if instantiation is required, they
15026 are instantiated right away. That allows for better code in the
15027 case that an expression refers to the value of the variable --
15028 if the variable has a constant value the referring expression can
15029 take advantage of that fact. */
15030 if (TREE_CODE (d) == VAR_DECL)
15033 /* Don't instantiate cloned functions. Instead, instantiate the
15034 functions they cloned. */
15035 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
15036 d = DECL_CLONED_FUNCTION (d);
15038 if (DECL_TEMPLATE_INSTANTIATED (d))
15039 /* D has already been instantiated. It might seem reasonable to
15040 check whether or not D is an explicit instantiation, and, if so,
15041 stop here. But when an explicit instantiation is deferred
15042 until the end of the compilation, DECL_EXPLICIT_INSTANTIATION
15043 is set, even though we still need to do the instantiation. */
15046 /* If we already have a specialization of this declaration, then
15047 there's no reason to instantiate it. Note that
15048 retrieve_specialization gives us both instantiations and
15049 specializations, so we must explicitly check
15050 DECL_TEMPLATE_SPECIALIZATION. */
15051 gen_tmpl = most_general_template (tmpl);
15052 gen_args = DECL_TI_ARGS (d);
15053 spec = retrieve_specialization (gen_tmpl, gen_args,
15054 /*class_specializations_p=*/false);
15055 if (spec != NULL_TREE && DECL_TEMPLATE_SPECIALIZATION (spec))
15058 /* This needs to happen before any tsubsting. */
15059 if (! push_tinst_level (d))
15062 timevar_push (TV_PARSE);
15064 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
15065 for the instantiation. */
15066 td = template_for_substitution (d);
15067 code_pattern = DECL_TEMPLATE_RESULT (td);
15069 /* We should never be trying to instantiate a member of a class
15070 template or partial specialization. */
15071 gcc_assert (d != code_pattern);
15073 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
15074 || DECL_TEMPLATE_SPECIALIZATION (td))
15075 /* In the case of a friend template whose definition is provided
15076 outside the class, we may have too many arguments. Drop the
15077 ones we don't need. The same is true for specializations. */
15078 args = get_innermost_template_args
15079 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
15083 if (TREE_CODE (d) == FUNCTION_DECL)
15084 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
15086 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
15088 /* We may be in the middle of deferred access check. Disable it now. */
15089 push_deferring_access_checks (dk_no_deferred);
15091 /* Unless an explicit instantiation directive has already determined
15092 the linkage of D, remember that a definition is available for
15094 if (pattern_defined
15095 && !DECL_INTERFACE_KNOWN (d)
15096 && !DECL_NOT_REALLY_EXTERN (d))
15097 mark_definable (d);
15099 input_location = DECL_SOURCE_LOCATION (d);
15101 /* If D is a member of an explicitly instantiated class template,
15102 and no definition is available, treat it like an implicit
15104 if (!pattern_defined && expl_inst_class_mem_p
15105 && DECL_EXPLICIT_INSTANTIATION (d))
15107 DECL_NOT_REALLY_EXTERN (d) = 0;
15108 DECL_INTERFACE_KNOWN (d) = 0;
15109 SET_DECL_IMPLICIT_INSTANTIATION (d);
15114 /* Recheck the substitutions to obtain any warning messages
15115 about ignoring cv qualifiers. */
15116 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
15117 tree type = TREE_TYPE (gen);
15119 /* Make sure that we can see identifiers, and compute access
15120 correctly. D is already the target FUNCTION_DECL with the
15122 push_access_scope (d);
15124 if (TREE_CODE (gen) == FUNCTION_DECL)
15126 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
15127 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
15129 /* Don't simply tsubst the function type, as that will give
15130 duplicate warnings about poor parameter qualifications.
15131 The function arguments are the same as the decl_arguments
15132 without the top level cv qualifiers. */
15133 type = TREE_TYPE (type);
15135 tsubst (type, gen_args, tf_warning_or_error, d);
15137 pop_access_scope (d);
15140 /* Check to see whether we know that this template will be
15141 instantiated in some other file, as with "extern template"
15143 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
15144 /* In general, we do not instantiate such templates... */
15146 /* ... but we instantiate inline functions so that we can inline
15148 && ! (TREE_CODE (d) == FUNCTION_DECL
15149 && possibly_inlined_p (d))
15150 /* ... we instantiate static data members whose values are
15151 needed in integral constant expressions. */
15152 && ! (TREE_CODE (d) == VAR_DECL
15153 && DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (d)))
15155 /* Defer all other templates, unless we have been explicitly
15156 forbidden from doing so. */
15157 if (/* If there is no definition, we cannot instantiate the
15160 /* If it's OK to postpone instantiation, do so. */
15162 /* If this is a static data member that will be defined
15163 elsewhere, we don't want to instantiate the entire data
15164 member, but we do want to instantiate the initializer so that
15165 we can substitute that elsewhere. */
15166 || (external_p && TREE_CODE (d) == VAR_DECL))
15168 /* The definition of the static data member is now required so
15169 we must substitute the initializer. */
15170 if (TREE_CODE (d) == VAR_DECL
15171 && !DECL_INITIAL (d)
15172 && DECL_INITIAL (code_pattern))
15177 ns = decl_namespace_context (d);
15178 push_nested_namespace (ns);
15179 push_nested_class (DECL_CONTEXT (d));
15180 init = tsubst_expr (DECL_INITIAL (code_pattern),
15182 tf_warning_or_error, NULL_TREE,
15183 /*integral_constant_expression_p=*/false);
15184 cp_finish_decl (d, init, /*init_const_expr_p=*/false,
15185 /*asmspec_tree=*/NULL_TREE,
15186 LOOKUP_ONLYCONVERTING);
15187 pop_nested_class ();
15188 pop_nested_namespace (ns);
15191 /* We restore the source position here because it's used by
15192 add_pending_template. */
15193 input_location = saved_loc;
15195 if (at_eof && !pattern_defined
15196 && DECL_EXPLICIT_INSTANTIATION (d))
15199 The definition of a non-exported function template, a
15200 non-exported member function template, or a non-exported
15201 member function or static data member of a class template
15202 shall be present in every translation unit in which it is
15203 explicitly instantiated. */
15204 permerror (input_location, "explicit instantiation of %qD "
15205 "but no definition available", d);
15207 /* ??? Historically, we have instantiated inline functions, even
15208 when marked as "extern template". */
15209 if (!(external_p && TREE_CODE (d) == VAR_DECL))
15210 add_pending_template (d);
15213 /* Tell the repository that D is available in this translation unit
15214 -- and see if it is supposed to be instantiated here. */
15215 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
15217 /* In a PCH file, despite the fact that the repository hasn't
15218 requested instantiation in the PCH it is still possible that
15219 an instantiation will be required in a file that includes the
15222 add_pending_template (d);
15223 /* Instantiate inline functions so that the inliner can do its
15224 job, even though we'll not be emitting a copy of this
15226 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
15230 need_push = !cfun || !global_bindings_p ();
15232 push_to_top_level ();
15234 /* Mark D as instantiated so that recursive calls to
15235 instantiate_decl do not try to instantiate it again. */
15236 DECL_TEMPLATE_INSTANTIATED (d) = 1;
15238 /* Regenerate the declaration in case the template has been modified
15239 by a subsequent redeclaration. */
15240 regenerate_decl_from_template (d, td);
15242 /* We already set the file and line above. Reset them now in case
15243 they changed as a result of calling regenerate_decl_from_template. */
15244 input_location = DECL_SOURCE_LOCATION (d);
15246 if (TREE_CODE (d) == VAR_DECL)
15250 /* Clear out DECL_RTL; whatever was there before may not be right
15251 since we've reset the type of the declaration. */
15252 SET_DECL_RTL (d, NULL_RTX);
15253 DECL_IN_AGGR_P (d) = 0;
15255 /* The initializer is placed in DECL_INITIAL by
15256 regenerate_decl_from_template. Pull it out so that
15257 finish_decl can process it. */
15258 init = DECL_INITIAL (d);
15259 DECL_INITIAL (d) = NULL_TREE;
15260 DECL_INITIALIZED_P (d) = 0;
15262 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
15263 initializer. That function will defer actual emission until
15264 we have a chance to determine linkage. */
15265 DECL_EXTERNAL (d) = 0;
15267 /* Enter the scope of D so that access-checking works correctly. */
15268 push_nested_class (DECL_CONTEXT (d));
15269 finish_decl (d, init, NULL_TREE);
15270 pop_nested_class ();
15272 else if (TREE_CODE (d) == FUNCTION_DECL)
15274 htab_t saved_local_specializations;
15279 /* Save away the current list, in case we are instantiating one
15280 template from within the body of another. */
15281 saved_local_specializations = local_specializations;
15283 /* Set up the list of local specializations. */
15284 local_specializations = htab_create (37,
15285 hash_local_specialization,
15286 eq_local_specializations,
15289 /* Set up context. */
15290 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
15292 /* Create substitution entries for the parameters. */
15293 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
15294 tmpl_parm = DECL_ARGUMENTS (subst_decl);
15295 spec_parm = DECL_ARGUMENTS (d);
15296 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
15298 register_local_specialization (spec_parm, tmpl_parm);
15299 spec_parm = skip_artificial_parms_for (d, spec_parm);
15300 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
15302 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
15304 register_local_specialization (spec_parm, tmpl_parm);
15305 tmpl_parm = TREE_CHAIN (tmpl_parm);
15306 spec_parm = TREE_CHAIN (spec_parm);
15308 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
15310 /* Collect all of the extra "packed" parameters into an
15314 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
15315 tree argtypepack = make_node (TYPE_ARGUMENT_PACK);
15319 /* Count how many parameters remain. */
15320 for (t = spec_parm; t; t = TREE_CHAIN (t))
15323 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
15324 parmvec = make_tree_vec (len);
15325 parmtypevec = make_tree_vec (len);
15326 for(i = 0; i < len; i++, spec_parm = TREE_CHAIN (spec_parm))
15328 TREE_VEC_ELT (parmvec, i) = spec_parm;
15329 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
15332 /* Build the argument packs. */
15333 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
15334 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
15335 TREE_TYPE (argpack) = argtypepack;
15337 /* Register the (value) argument pack as a specialization of
15338 TMPL_PARM, then move on. */
15339 register_local_specialization (argpack, tmpl_parm);
15340 tmpl_parm = TREE_CHAIN (tmpl_parm);
15342 gcc_assert (!spec_parm);
15344 /* Substitute into the body of the function. */
15345 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
15346 tf_warning_or_error, tmpl,
15347 /*integral_constant_expression_p=*/false);
15349 /* Set the current input_location to the end of the function
15350 so that finish_function knows where we are. */
15351 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
15353 /* We don't need the local specializations any more. */
15354 htab_delete (local_specializations);
15355 local_specializations = saved_local_specializations;
15357 /* Finish the function. */
15358 d = finish_function (0);
15359 expand_or_defer_fn (d);
15362 /* We're not deferring instantiation any more. */
15363 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
15366 pop_from_top_level ();
15369 input_location = saved_loc;
15370 pop_deferring_access_checks ();
15371 pop_tinst_level ();
15373 timevar_pop (TV_PARSE);
15378 /* Run through the list of templates that we wish we could
15379 instantiate, and instantiate any we can. RETRIES is the
15380 number of times we retry pending template instantiation. */
15383 instantiate_pending_templates (int retries)
15386 location_t saved_loc = input_location;
15388 /* Instantiating templates may trigger vtable generation. This in turn
15389 may require further template instantiations. We place a limit here
15390 to avoid infinite loop. */
15391 if (pending_templates && retries >= max_tinst_depth)
15393 tree decl = pending_templates->tinst->decl;
15395 error ("template instantiation depth exceeds maximum of %d"
15396 " instantiating %q+D, possibly from virtual table generation"
15397 " (use -ftemplate-depth-NN to increase the maximum)",
15398 max_tinst_depth, decl);
15399 if (TREE_CODE (decl) == FUNCTION_DECL)
15400 /* Pretend that we defined it. */
15401 DECL_INITIAL (decl) = error_mark_node;
15407 struct pending_template **t = &pending_templates;
15408 struct pending_template *last = NULL;
15412 tree instantiation = reopen_tinst_level ((*t)->tinst);
15413 bool complete = false;
15415 if (TYPE_P (instantiation))
15419 if (!COMPLETE_TYPE_P (instantiation))
15421 instantiate_class_template (instantiation);
15422 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
15423 for (fn = TYPE_METHODS (instantiation);
15425 fn = TREE_CHAIN (fn))
15426 if (! DECL_ARTIFICIAL (fn))
15427 instantiate_decl (fn,
15429 /*expl_inst_class_mem_p=*/false);
15430 if (COMPLETE_TYPE_P (instantiation))
15434 complete = COMPLETE_TYPE_P (instantiation);
15438 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
15439 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
15442 = instantiate_decl (instantiation,
15444 /*expl_inst_class_mem_p=*/false);
15445 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
15449 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
15450 || DECL_TEMPLATE_INSTANTIATED (instantiation));
15454 /* If INSTANTIATION has been instantiated, then we don't
15455 need to consider it again in the future. */
15463 current_tinst_level = NULL;
15465 last_pending_template = last;
15467 while (reconsider);
15469 input_location = saved_loc;
15472 /* Substitute ARGVEC into T, which is a list of initializers for
15473 either base class or a non-static data member. The TREE_PURPOSEs
15474 are DECLs, and the TREE_VALUEs are the initializer values. Used by
15475 instantiate_decl. */
15478 tsubst_initializer_list (tree t, tree argvec)
15480 tree inits = NULL_TREE;
15482 for (; t; t = TREE_CHAIN (t))
15486 tree expanded_bases = NULL_TREE;
15487 tree expanded_arguments = NULL_TREE;
15490 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
15495 /* Expand the base class expansion type into separate base
15497 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
15498 tf_warning_or_error,
15500 if (expanded_bases == error_mark_node)
15503 /* We'll be building separate TREE_LISTs of arguments for
15505 len = TREE_VEC_LENGTH (expanded_bases);
15506 expanded_arguments = make_tree_vec (len);
15507 for (i = 0; i < len; i++)
15508 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
15510 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
15511 expand each argument in the TREE_VALUE of t. */
15512 expr = make_node (EXPR_PACK_EXPANSION);
15513 PACK_EXPANSION_PARAMETER_PACKS (expr) =
15514 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
15516 if (TREE_VALUE (t) == void_type_node)
15517 /* VOID_TYPE_NODE is used to indicate
15518 value-initialization. */
15520 for (i = 0; i < len; i++)
15521 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
15525 /* Substitute parameter packs into each argument in the
15527 in_base_initializer = 1;
15528 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
15530 tree expanded_exprs;
15532 /* Expand the argument. */
15533 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
15535 = tsubst_pack_expansion (expr, argvec,
15536 tf_warning_or_error,
15538 if (expanded_exprs == error_mark_node)
15541 /* Prepend each of the expanded expressions to the
15542 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
15543 for (i = 0; i < len; i++)
15545 TREE_VEC_ELT (expanded_arguments, i) =
15546 tree_cons (NULL_TREE,
15547 TREE_VEC_ELT (expanded_exprs, i),
15548 TREE_VEC_ELT (expanded_arguments, i));
15551 in_base_initializer = 0;
15553 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
15554 since we built them backwards. */
15555 for (i = 0; i < len; i++)
15557 TREE_VEC_ELT (expanded_arguments, i) =
15558 nreverse (TREE_VEC_ELT (expanded_arguments, i));
15563 for (i = 0; i < len; ++i)
15565 if (expanded_bases)
15567 decl = TREE_VEC_ELT (expanded_bases, i);
15568 decl = expand_member_init (decl);
15569 init = TREE_VEC_ELT (expanded_arguments, i);
15573 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
15574 tf_warning_or_error, NULL_TREE);
15576 decl = expand_member_init (decl);
15577 if (decl && !DECL_P (decl))
15578 in_base_initializer = 1;
15580 init = tsubst_expr (TREE_VALUE (t), argvec,
15581 tf_warning_or_error, NULL_TREE,
15582 /*integral_constant_expression_p=*/false);
15583 in_base_initializer = 0;
15588 init = build_tree_list (decl, init);
15589 TREE_CHAIN (init) = inits;
15597 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
15600 set_current_access_from_decl (tree decl)
15602 if (TREE_PRIVATE (decl))
15603 current_access_specifier = access_private_node;
15604 else if (TREE_PROTECTED (decl))
15605 current_access_specifier = access_protected_node;
15607 current_access_specifier = access_public_node;
15610 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
15611 is the instantiation (which should have been created with
15612 start_enum) and ARGS are the template arguments to use. */
15615 tsubst_enum (tree tag, tree newtag, tree args)
15619 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
15624 decl = TREE_VALUE (e);
15625 /* Note that in a template enum, the TREE_VALUE is the
15626 CONST_DECL, not the corresponding INTEGER_CST. */
15627 value = tsubst_expr (DECL_INITIAL (decl),
15628 args, tf_warning_or_error, NULL_TREE,
15629 /*integral_constant_expression_p=*/true);
15631 /* Give this enumeration constant the correct access. */
15632 set_current_access_from_decl (decl);
15634 /* Actually build the enumerator itself. */
15635 build_enumerator (DECL_NAME (decl), value, newtag);
15638 finish_enum (newtag);
15639 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
15640 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
15643 /* DECL is a FUNCTION_DECL that is a template specialization. Return
15644 its type -- but without substituting the innermost set of template
15645 arguments. So, innermost set of template parameters will appear in
15649 get_mostly_instantiated_function_type (tree decl)
15657 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
15658 targs = DECL_TI_ARGS (decl);
15659 tparms = DECL_TEMPLATE_PARMS (tmpl);
15660 parm_depth = TMPL_PARMS_DEPTH (tparms);
15662 /* There should be as many levels of arguments as there are levels
15664 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
15666 fn_type = TREE_TYPE (tmpl);
15668 if (parm_depth == 1)
15669 /* No substitution is necessary. */
15673 int i, save_access_control;
15676 /* Replace the innermost level of the TARGS with NULL_TREEs to
15677 let tsubst know not to substitute for those parameters. */
15678 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
15679 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
15680 SET_TMPL_ARGS_LEVEL (partial_args, i,
15681 TMPL_ARGS_LEVEL (targs, i));
15682 SET_TMPL_ARGS_LEVEL (partial_args,
15683 TMPL_ARGS_DEPTH (targs),
15684 make_tree_vec (DECL_NTPARMS (tmpl)));
15686 /* Disable access control as this function is used only during
15688 save_access_control = flag_access_control;
15689 flag_access_control = 0;
15691 ++processing_template_decl;
15692 /* Now, do the (partial) substitution to figure out the
15693 appropriate function type. */
15694 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
15695 --processing_template_decl;
15697 /* Substitute into the template parameters to obtain the real
15698 innermost set of parameters. This step is important if the
15699 innermost set of template parameters contains value
15700 parameters whose types depend on outer template parameters. */
15701 TREE_VEC_LENGTH (partial_args)--;
15702 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
15704 flag_access_control = save_access_control;
15710 /* Return truthvalue if we're processing a template different from
15711 the last one involved in diagnostics. */
15713 problematic_instantiation_changed (void)
15715 return last_template_error_tick != tinst_level_tick;
15718 /* Remember current template involved in diagnostics. */
15720 record_last_problematic_instantiation (void)
15722 last_template_error_tick = tinst_level_tick;
15725 struct tinst_level *
15726 current_instantiation (void)
15728 return current_tinst_level;
15731 /* [temp.param] Check that template non-type parm TYPE is of an allowable
15732 type. Return zero for ok, nonzero for disallowed. Issue error and
15733 warning messages under control of COMPLAIN. */
15736 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
15738 if (INTEGRAL_TYPE_P (type))
15740 else if (POINTER_TYPE_P (type))
15742 else if (TYPE_PTR_TO_MEMBER_P (type))
15744 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
15746 else if (TREE_CODE (type) == TYPENAME_TYPE)
15749 if (complain & tf_error)
15750 error ("%q#T is not a valid type for a template constant parameter", type);
15754 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
15755 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
15758 dependent_type_p_r (tree type)
15764 A type is dependent if it is:
15766 -- a template parameter. Template template parameters are types
15767 for us (since TYPE_P holds true for them) so we handle
15769 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
15770 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
15772 /* -- a qualified-id with a nested-name-specifier which contains a
15773 class-name that names a dependent type or whose unqualified-id
15774 names a dependent type. */
15775 if (TREE_CODE (type) == TYPENAME_TYPE)
15777 /* -- a cv-qualified type where the cv-unqualified type is
15779 type = TYPE_MAIN_VARIANT (type);
15780 /* -- a compound type constructed from any dependent type. */
15781 if (TYPE_PTR_TO_MEMBER_P (type))
15782 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
15783 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
15785 else if (TREE_CODE (type) == POINTER_TYPE
15786 || TREE_CODE (type) == REFERENCE_TYPE)
15787 return dependent_type_p (TREE_TYPE (type));
15788 else if (TREE_CODE (type) == FUNCTION_TYPE
15789 || TREE_CODE (type) == METHOD_TYPE)
15793 if (dependent_type_p (TREE_TYPE (type)))
15795 for (arg_type = TYPE_ARG_TYPES (type);
15797 arg_type = TREE_CHAIN (arg_type))
15798 if (dependent_type_p (TREE_VALUE (arg_type)))
15802 /* -- an array type constructed from any dependent type or whose
15803 size is specified by a constant expression that is
15804 value-dependent. */
15805 if (TREE_CODE (type) == ARRAY_TYPE)
15807 if (TYPE_DOMAIN (type)
15808 && dependent_type_p (TYPE_DOMAIN (type)))
15810 return dependent_type_p (TREE_TYPE (type));
15812 else if (TREE_CODE (type) == INTEGER_TYPE
15813 && !TREE_CONSTANT (TYPE_MAX_VALUE (type)))
15815 /* If this is the TYPE_DOMAIN of an array type, consider it
15817 return (value_dependent_expression_p (TYPE_MAX_VALUE (type))
15818 || type_dependent_expression_p (TYPE_MAX_VALUE (type)));
15821 /* -- a template-id in which either the template name is a template
15823 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
15825 /* ... or any of the template arguments is a dependent type or
15826 an expression that is type-dependent or value-dependent. */
15827 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
15828 && (any_dependent_template_arguments_p
15829 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
15832 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
15833 argument of the `typeof' expression is not type-dependent, then
15834 it should already been have resolved. */
15835 if (TREE_CODE (type) == TYPEOF_TYPE
15836 || TREE_CODE (type) == DECLTYPE_TYPE)
15839 /* A template argument pack is dependent if any of its packed
15841 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
15843 tree args = ARGUMENT_PACK_ARGS (type);
15844 int i, len = TREE_VEC_LENGTH (args);
15845 for (i = 0; i < len; ++i)
15846 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
15850 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
15851 be template parameters. */
15852 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
15855 /* The standard does not specifically mention types that are local
15856 to template functions or local classes, but they should be
15857 considered dependent too. For example:
15859 template <int I> void f() {
15864 The size of `E' cannot be known until the value of `I' has been
15865 determined. Therefore, `E' must be considered dependent. */
15866 scope = TYPE_CONTEXT (type);
15867 if (scope && TYPE_P (scope))
15868 return dependent_type_p (scope);
15869 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
15870 return type_dependent_expression_p (scope);
15872 /* Other types are non-dependent. */
15876 /* Returns TRUE if TYPE is dependent, in the sense of
15877 [temp.dep.type]. */
15880 dependent_type_p (tree type)
15882 /* If there are no template parameters in scope, then there can't be
15883 any dependent types. */
15884 if (!processing_template_decl)
15886 /* If we are not processing a template, then nobody should be
15887 providing us with a dependent type. */
15889 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM);
15893 /* If the type is NULL, we have not computed a type for the entity
15894 in question; in that case, the type is dependent. */
15898 /* Erroneous types can be considered non-dependent. */
15899 if (type == error_mark_node)
15902 /* If we have not already computed the appropriate value for TYPE,
15904 if (!TYPE_DEPENDENT_P_VALID (type))
15906 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
15907 TYPE_DEPENDENT_P_VALID (type) = 1;
15910 return TYPE_DEPENDENT_P (type);
15913 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
15916 dependent_scope_ref_p (tree expression, bool criterion (tree))
15921 gcc_assert (TREE_CODE (expression) == SCOPE_REF);
15923 if (!TYPE_P (TREE_OPERAND (expression, 0)))
15926 scope = TREE_OPERAND (expression, 0);
15927 name = TREE_OPERAND (expression, 1);
15931 An id-expression is type-dependent if it contains a
15932 nested-name-specifier that contains a class-name that names a
15934 /* The suggested resolution to Core Issue 2 implies that if the
15935 qualifying type is the current class, then we must peek
15938 && currently_open_class (scope)
15939 && !criterion (name))
15941 if (dependent_type_p (scope))
15947 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
15948 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
15952 value_dependent_expression_p (tree expression)
15954 if (!processing_template_decl)
15957 /* A name declared with a dependent type. */
15958 if (DECL_P (expression) && type_dependent_expression_p (expression))
15961 switch (TREE_CODE (expression))
15963 case IDENTIFIER_NODE:
15964 /* A name that has not been looked up -- must be dependent. */
15967 case TEMPLATE_PARM_INDEX:
15968 /* A non-type template parm. */
15972 /* A non-type template parm. */
15973 if (DECL_TEMPLATE_PARM_P (expression))
15975 return value_dependent_expression_p (DECL_INITIAL (expression));
15978 /* A constant with integral or enumeration type and is initialized
15979 with an expression that is value-dependent. */
15980 if (DECL_INITIAL (expression)
15981 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
15982 && value_dependent_expression_p (DECL_INITIAL (expression)))
15986 case DYNAMIC_CAST_EXPR:
15987 case STATIC_CAST_EXPR:
15988 case CONST_CAST_EXPR:
15989 case REINTERPRET_CAST_EXPR:
15991 /* These expressions are value-dependent if the type to which
15992 the cast occurs is dependent or the expression being casted
15993 is value-dependent. */
15995 tree type = TREE_TYPE (expression);
15997 if (dependent_type_p (type))
16000 /* A functional cast has a list of operands. */
16001 expression = TREE_OPERAND (expression, 0);
16004 /* If there are no operands, it must be an expression such
16005 as "int()". This should not happen for aggregate types
16006 because it would form non-constant expressions. */
16007 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
16012 if (TREE_CODE (expression) == TREE_LIST)
16013 return any_value_dependent_elements_p (expression);
16015 return value_dependent_expression_p (expression);
16020 /* A `sizeof' expression is value-dependent if the operand is
16021 type-dependent or is a pack expansion. */
16022 expression = TREE_OPERAND (expression, 0);
16023 if (PACK_EXPANSION_P (expression))
16025 else if (TYPE_P (expression))
16026 return dependent_type_p (expression);
16027 return type_dependent_expression_p (expression);
16030 return dependent_scope_ref_p (expression, value_dependent_expression_p);
16032 case COMPONENT_REF:
16033 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
16034 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
16037 /* A CALL_EXPR may appear in a constant expression if it is a
16038 call to a builtin function, e.g., __builtin_constant_p. All
16039 such calls are value-dependent. */
16042 case NONTYPE_ARGUMENT_PACK:
16043 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
16044 is value-dependent. */
16046 tree values = ARGUMENT_PACK_ARGS (expression);
16047 int i, len = TREE_VEC_LENGTH (values);
16049 for (i = 0; i < len; ++i)
16050 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
16058 tree type2 = TRAIT_EXPR_TYPE2 (expression);
16059 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
16060 || (type2 ? dependent_type_p (type2) : false));
16064 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
16065 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
16068 /* A constant expression is value-dependent if any subexpression is
16069 value-dependent. */
16070 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
16072 case tcc_reference:
16074 return (value_dependent_expression_p
16075 (TREE_OPERAND (expression, 0)));
16077 case tcc_comparison:
16079 return ((value_dependent_expression_p
16080 (TREE_OPERAND (expression, 0)))
16081 || (value_dependent_expression_p
16082 (TREE_OPERAND (expression, 1))));
16084 case tcc_expression:
16088 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
16089 /* In some cases, some of the operands may be missing.
16090 (For example, in the case of PREDECREMENT_EXPR, the
16091 amount to increment by may be missing.) That doesn't
16092 make the expression dependent. */
16093 if (TREE_OPERAND (expression, i)
16094 && (value_dependent_expression_p
16095 (TREE_OPERAND (expression, i))))
16105 /* The expression is not value-dependent. */
16109 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
16110 [temp.dep.expr]. */
16113 type_dependent_expression_p (tree expression)
16115 if (!processing_template_decl)
16118 if (expression == error_mark_node)
16121 /* An unresolved name is always dependent. */
16122 if (TREE_CODE (expression) == IDENTIFIER_NODE
16123 || TREE_CODE (expression) == USING_DECL)
16126 /* Some expression forms are never type-dependent. */
16127 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
16128 || TREE_CODE (expression) == SIZEOF_EXPR
16129 || TREE_CODE (expression) == ALIGNOF_EXPR
16130 || TREE_CODE (expression) == TRAIT_EXPR
16131 || TREE_CODE (expression) == TYPEID_EXPR
16132 || TREE_CODE (expression) == DELETE_EXPR
16133 || TREE_CODE (expression) == VEC_DELETE_EXPR
16134 || TREE_CODE (expression) == THROW_EXPR)
16137 /* The types of these expressions depends only on the type to which
16138 the cast occurs. */
16139 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
16140 || TREE_CODE (expression) == STATIC_CAST_EXPR
16141 || TREE_CODE (expression) == CONST_CAST_EXPR
16142 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
16143 || TREE_CODE (expression) == CAST_EXPR)
16144 return dependent_type_p (TREE_TYPE (expression));
16146 /* The types of these expressions depends only on the type created
16147 by the expression. */
16148 if (TREE_CODE (expression) == NEW_EXPR
16149 || TREE_CODE (expression) == VEC_NEW_EXPR)
16151 /* For NEW_EXPR tree nodes created inside a template, either
16152 the object type itself or a TREE_LIST may appear as the
16154 tree type = TREE_OPERAND (expression, 1);
16155 if (TREE_CODE (type) == TREE_LIST)
16156 /* This is an array type. We need to check array dimensions
16158 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
16159 || value_dependent_expression_p
16160 (TREE_OPERAND (TREE_VALUE (type), 1));
16162 return dependent_type_p (type);
16165 if (TREE_CODE (expression) == SCOPE_REF
16166 && dependent_scope_ref_p (expression,
16167 type_dependent_expression_p))
16170 if (TREE_CODE (expression) == FUNCTION_DECL
16171 && DECL_LANG_SPECIFIC (expression)
16172 && DECL_TEMPLATE_INFO (expression)
16173 && (any_dependent_template_arguments_p
16174 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
16177 if (TREE_CODE (expression) == TEMPLATE_DECL
16178 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
16181 if (TREE_CODE (expression) == STMT_EXPR)
16182 expression = stmt_expr_value_expr (expression);
16184 if (TREE_TYPE (expression) == unknown_type_node)
16186 if (TREE_CODE (expression) == ADDR_EXPR)
16187 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
16188 if (TREE_CODE (expression) == COMPONENT_REF
16189 || TREE_CODE (expression) == OFFSET_REF)
16191 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
16193 expression = TREE_OPERAND (expression, 1);
16194 if (TREE_CODE (expression) == IDENTIFIER_NODE)
16197 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
16198 if (TREE_CODE (expression) == SCOPE_REF)
16201 if (TREE_CODE (expression) == BASELINK)
16202 expression = BASELINK_FUNCTIONS (expression);
16204 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
16206 if (any_dependent_template_arguments_p
16207 (TREE_OPERAND (expression, 1)))
16209 expression = TREE_OPERAND (expression, 0);
16211 gcc_assert (TREE_CODE (expression) == OVERLOAD
16212 || TREE_CODE (expression) == FUNCTION_DECL);
16216 if (type_dependent_expression_p (OVL_CURRENT (expression)))
16218 expression = OVL_NEXT (expression);
16223 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
16225 return (dependent_type_p (TREE_TYPE (expression)));
16228 /* Returns TRUE if ARGS (a TREE_LIST of arguments to a function call)
16229 contains a type-dependent expression. */
16232 any_type_dependent_arguments_p (const_tree args)
16236 tree arg = TREE_VALUE (args);
16238 if (type_dependent_expression_p (arg))
16240 args = TREE_CHAIN (args);
16245 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
16246 expressions) contains any value-dependent expressions. */
16249 any_value_dependent_elements_p (const_tree list)
16251 for (; list; list = TREE_CHAIN (list))
16252 if (value_dependent_expression_p (TREE_VALUE (list)))
16258 /* Returns TRUE if the ARG (a template argument) is dependent. */
16261 dependent_template_arg_p (tree arg)
16263 if (!processing_template_decl)
16266 if (TREE_CODE (arg) == TEMPLATE_DECL
16267 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
16268 return dependent_template_p (arg);
16269 else if (ARGUMENT_PACK_P (arg))
16271 tree args = ARGUMENT_PACK_ARGS (arg);
16272 int i, len = TREE_VEC_LENGTH (args);
16273 for (i = 0; i < len; ++i)
16275 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
16281 else if (TYPE_P (arg))
16282 return dependent_type_p (arg);
16284 return (type_dependent_expression_p (arg)
16285 || value_dependent_expression_p (arg));
16288 /* Returns true if ARGS (a collection of template arguments) contains
16289 any types that require structural equality testing. */
16292 any_template_arguments_need_structural_equality_p (tree args)
16299 if (args == error_mark_node)
16302 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
16304 tree level = TMPL_ARGS_LEVEL (args, i + 1);
16305 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
16307 tree arg = TREE_VEC_ELT (level, j);
16308 tree packed_args = NULL_TREE;
16311 if (ARGUMENT_PACK_P (arg))
16313 /* Look inside the argument pack. */
16314 packed_args = ARGUMENT_PACK_ARGS (arg);
16315 len = TREE_VEC_LENGTH (packed_args);
16318 for (k = 0; k < len; ++k)
16321 arg = TREE_VEC_ELT (packed_args, k);
16323 if (error_operand_p (arg))
16325 else if (TREE_CODE (arg) == TEMPLATE_DECL
16326 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
16328 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
16330 else if (!TYPE_P (arg) && TREE_TYPE (arg)
16331 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
16340 /* Returns true if ARGS (a collection of template arguments) contains
16341 any dependent arguments. */
16344 any_dependent_template_arguments_p (const_tree args)
16351 if (args == error_mark_node)
16354 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
16356 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
16357 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
16358 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
16365 /* Returns TRUE if the template TMPL is dependent. */
16368 dependent_template_p (tree tmpl)
16370 if (TREE_CODE (tmpl) == OVERLOAD)
16374 if (dependent_template_p (OVL_FUNCTION (tmpl)))
16376 tmpl = OVL_CHAIN (tmpl);
16381 /* Template template parameters are dependent. */
16382 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
16383 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
16385 /* So are names that have not been looked up. */
16386 if (TREE_CODE (tmpl) == SCOPE_REF
16387 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
16389 /* So are member templates of dependent classes. */
16390 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
16391 return dependent_type_p (DECL_CONTEXT (tmpl));
16395 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
16398 dependent_template_id_p (tree tmpl, tree args)
16400 return (dependent_template_p (tmpl)
16401 || any_dependent_template_arguments_p (args));
16404 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
16408 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
16412 if (!processing_template_decl)
16415 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
16417 tree decl = TREE_VEC_ELT (declv, i);
16418 tree init = TREE_VEC_ELT (initv, i);
16419 tree cond = TREE_VEC_ELT (condv, i);
16420 tree incr = TREE_VEC_ELT (incrv, i);
16422 if (type_dependent_expression_p (decl))
16425 if (init && type_dependent_expression_p (init))
16428 if (type_dependent_expression_p (cond))
16431 if (COMPARISON_CLASS_P (cond)
16432 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
16433 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
16436 if (TREE_CODE (incr) == MODOP_EXPR)
16438 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
16439 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
16442 else if (type_dependent_expression_p (incr))
16444 else if (TREE_CODE (incr) == MODIFY_EXPR)
16446 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
16448 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
16450 tree t = TREE_OPERAND (incr, 1);
16451 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
16452 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
16461 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
16462 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
16463 no such TYPE can be found. Note that this function peers inside
16464 uninstantiated templates and therefore should be used only in
16465 extremely limited situations. ONLY_CURRENT_P restricts this
16466 peering to the currently open classes hierarchy (which is required
16467 when comparing types). */
16470 resolve_typename_type (tree type, bool only_current_p)
16479 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
16481 scope = TYPE_CONTEXT (type);
16482 name = TYPE_IDENTIFIER (type);
16484 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
16485 it first before we can figure out what NAME refers to. */
16486 if (TREE_CODE (scope) == TYPENAME_TYPE)
16487 scope = resolve_typename_type (scope, only_current_p);
16488 /* If we don't know what SCOPE refers to, then we cannot resolve the
16490 if (TREE_CODE (scope) == TYPENAME_TYPE)
16492 /* If the SCOPE is a template type parameter, we have no way of
16493 resolving the name. */
16494 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
16496 /* If the SCOPE is not the current instantiation, there's no reason
16497 to look inside it. */
16498 if (only_current_p && !currently_open_class (scope))
16500 /* If SCOPE isn't the template itself, it will not have a valid
16501 TYPE_FIELDS list. */
16502 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
16503 /* scope is either the template itself or a compatible instantiation
16504 like X<T>, so look up the name in the original template. */
16505 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
16507 /* scope is a partial instantiation, so we can't do the lookup or we
16508 will lose the template arguments. */
16510 /* Enter the SCOPE so that name lookup will be resolved as if we
16511 were in the class definition. In particular, SCOPE will no
16512 longer be considered a dependent type. */
16513 pushed_scope = push_scope (scope);
16514 /* Look up the declaration. */
16515 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
16517 result = NULL_TREE;
16519 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
16520 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
16523 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
16524 && TREE_CODE (decl) == TYPE_DECL)
16526 result = TREE_TYPE (decl);
16527 if (result == error_mark_node)
16528 result = NULL_TREE;
16530 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
16531 && DECL_CLASS_TEMPLATE_P (decl))
16535 /* Obtain the template and the arguments. */
16536 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
16537 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
16538 /* Instantiate the template. */
16539 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
16540 /*entering_scope=*/0,
16541 tf_error | tf_user);
16542 if (result == error_mark_node)
16543 result = NULL_TREE;
16546 /* Leave the SCOPE. */
16548 pop_scope (pushed_scope);
16550 /* If we failed to resolve it, return the original typename. */
16554 /* If lookup found a typename type, resolve that too. */
16555 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
16557 /* Ill-formed programs can cause infinite recursion here, so we
16558 must catch that. */
16559 TYPENAME_IS_RESOLVING_P (type) = 1;
16560 result = resolve_typename_type (result, only_current_p);
16561 TYPENAME_IS_RESOLVING_P (type) = 0;
16564 /* Qualify the resulting type. */
16565 quals = cp_type_quals (type);
16567 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
16572 /* EXPR is an expression which is not type-dependent. Return a proxy
16573 for EXPR that can be used to compute the types of larger
16574 expressions containing EXPR. */
16577 build_non_dependent_expr (tree expr)
16581 /* Preserve null pointer constants so that the type of things like
16582 "p == 0" where "p" is a pointer can be determined. */
16583 if (null_ptr_cst_p (expr))
16585 /* Preserve OVERLOADs; the functions must be available to resolve
16588 if (TREE_CODE (inner_expr) == STMT_EXPR)
16589 inner_expr = stmt_expr_value_expr (inner_expr);
16590 if (TREE_CODE (inner_expr) == ADDR_EXPR)
16591 inner_expr = TREE_OPERAND (inner_expr, 0);
16592 if (TREE_CODE (inner_expr) == COMPONENT_REF)
16593 inner_expr = TREE_OPERAND (inner_expr, 1);
16594 if (is_overloaded_fn (inner_expr)
16595 || TREE_CODE (inner_expr) == OFFSET_REF)
16597 /* There is no need to return a proxy for a variable. */
16598 if (TREE_CODE (expr) == VAR_DECL)
16600 /* Preserve string constants; conversions from string constants to
16601 "char *" are allowed, even though normally a "const char *"
16602 cannot be used to initialize a "char *". */
16603 if (TREE_CODE (expr) == STRING_CST)
16605 /* Preserve arithmetic constants, as an optimization -- there is no
16606 reason to create a new node. */
16607 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
16609 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
16610 There is at least one place where we want to know that a
16611 particular expression is a throw-expression: when checking a ?:
16612 expression, there are special rules if the second or third
16613 argument is a throw-expression. */
16614 if (TREE_CODE (expr) == THROW_EXPR)
16617 if (TREE_CODE (expr) == COND_EXPR)
16618 return build3 (COND_EXPR,
16620 TREE_OPERAND (expr, 0),
16621 (TREE_OPERAND (expr, 1)
16622 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
16623 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
16624 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
16625 if (TREE_CODE (expr) == COMPOUND_EXPR
16626 && !COMPOUND_EXPR_OVERLOADED (expr))
16627 return build2 (COMPOUND_EXPR,
16629 TREE_OPERAND (expr, 0),
16630 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
16632 /* If the type is unknown, it can't really be non-dependent */
16633 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
16635 /* Otherwise, build a NON_DEPENDENT_EXPR.
16637 REFERENCE_TYPEs are not stripped for expressions in templates
16638 because doing so would play havoc with mangling. Consider, for
16641 template <typename T> void f<T& g>() { g(); }
16643 In the body of "f", the expression for "g" will have
16644 REFERENCE_TYPE, even though the standard says that it should
16645 not. The reason is that we must preserve the syntactic form of
16646 the expression so that mangling (say) "f<g>" inside the body of
16647 "f" works out correctly. Therefore, the REFERENCE_TYPE is
16649 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
16652 /* ARGS is a TREE_LIST of expressions as arguments to a function call.
16653 Return a new TREE_LIST with the various arguments replaced with
16654 equivalent non-dependent expressions. */
16657 build_non_dependent_args (tree args)
16662 new_args = NULL_TREE;
16663 for (a = args; a; a = TREE_CHAIN (a))
16664 new_args = tree_cons (NULL_TREE,
16665 build_non_dependent_expr (TREE_VALUE (a)),
16667 return nreverse (new_args);
16670 #include "gt-cp-pt.h"