1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
39 #include "cp-objcp-common.h"
40 #include "tree-inline.h"
47 #include "tree-iterator.h"
50 /* The type of functions taking a tree, and some additional data, and
52 typedef int (*tree_fn_t) (tree, void*);
54 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
55 instantiations have been deferred, either because their definitions
56 were not yet available, or because we were putting off doing the work. */
57 struct GTY (()) pending_template {
58 struct pending_template *next;
59 struct tinst_level *tinst;
62 static GTY(()) struct pending_template *pending_templates;
63 static GTY(()) struct pending_template *last_pending_template;
65 int processing_template_parmlist;
66 static int template_header_count;
68 static GTY(()) tree saved_trees;
69 static VEC(int,heap) *inline_parm_levels;
71 static GTY(()) struct tinst_level *current_tinst_level;
73 static GTY(()) tree saved_access_scope;
75 /* Live only within one (recursive) call to tsubst_expr. We use
76 this to pass the statement expression node from the STMT_EXPR
77 to the EXPR_STMT that is its result. */
78 static tree cur_stmt_expr;
80 /* A map from local variable declarations in the body of the template
81 presently being instantiated to the corresponding instantiated
83 static htab_t local_specializations;
85 typedef struct GTY(()) spec_entry
92 static GTY ((param_is (spec_entry)))
93 htab_t decl_specializations;
95 static GTY ((param_is (spec_entry)))
96 htab_t type_specializations;
98 /* Contains canonical template parameter types. The vector is indexed by
99 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
100 TREE_LIST, whose TREE_VALUEs contain the canonical template
101 parameters of various types and levels. */
102 static GTY(()) VEC(tree,gc) *canonical_template_parms;
104 #define UNIFY_ALLOW_NONE 0
105 #define UNIFY_ALLOW_MORE_CV_QUAL 1
106 #define UNIFY_ALLOW_LESS_CV_QUAL 2
107 #define UNIFY_ALLOW_DERIVED 4
108 #define UNIFY_ALLOW_INTEGER 8
109 #define UNIFY_ALLOW_OUTER_LEVEL 16
110 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
111 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
113 static void push_access_scope (tree);
114 static void pop_access_scope (tree);
115 static bool resolve_overloaded_unification (tree, tree, tree, tree,
116 unification_kind_t, int);
117 static int try_one_overload (tree, tree, tree, tree, tree,
118 unification_kind_t, int, bool);
119 static int unify (tree, tree, tree, tree, int);
120 static void add_pending_template (tree);
121 static int push_tinst_level (tree);
122 static void pop_tinst_level (void);
123 static tree reopen_tinst_level (struct tinst_level *);
124 static tree tsubst_initializer_list (tree, tree);
125 static tree get_class_bindings (tree, tree, tree);
126 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
128 static void tsubst_enum (tree, tree, tree);
129 static tree add_to_template_args (tree, tree);
130 static tree add_outermost_template_args (tree, tree);
131 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
132 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
134 static int type_unification_real (tree, tree, tree, const tree *,
135 unsigned int, int, unification_kind_t, int);
136 static void note_template_header (int);
137 static tree convert_nontype_argument_function (tree, tree);
138 static tree convert_nontype_argument (tree, tree);
139 static tree convert_template_argument (tree, tree, tree,
140 tsubst_flags_t, int, tree);
141 static int for_each_template_parm (tree, tree_fn_t, void*,
142 struct pointer_set_t*, bool);
143 static tree expand_template_argument_pack (tree);
144 static tree build_template_parm_index (int, int, int, tree, tree);
145 static bool inline_needs_template_parms (tree);
146 static void push_inline_template_parms_recursive (tree, int);
147 static tree retrieve_local_specialization (tree);
148 static void register_local_specialization (tree, tree);
149 static hashval_t hash_specialization (const void *p);
150 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
151 static int mark_template_parm (tree, void *);
152 static int template_parm_this_level_p (tree, void *);
153 static tree tsubst_friend_function (tree, tree);
154 static tree tsubst_friend_class (tree, tree);
155 static int can_complete_type_without_circularity (tree);
156 static tree get_bindings (tree, tree, tree, bool);
157 static int template_decl_level (tree);
158 static int check_cv_quals_for_unify (int, tree, tree);
159 static void template_parm_level_and_index (tree, int*, int*);
160 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
161 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
162 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
163 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
164 static void regenerate_decl_from_template (tree, tree);
165 static tree most_specialized_class (tree, tree);
166 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
167 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
168 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
169 static bool check_specialization_scope (void);
170 static tree process_partial_specialization (tree);
171 static void set_current_access_from_decl (tree);
172 static tree get_template_base (tree, tree, tree, tree);
173 static tree try_class_unification (tree, tree, tree, tree);
174 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
176 static bool template_template_parm_bindings_ok_p (tree, tree);
177 static int template_args_equal (tree, tree);
178 static void tsubst_default_arguments (tree);
179 static tree for_each_template_parm_r (tree *, int *, void *);
180 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
181 static void copy_default_args_to_explicit_spec (tree);
182 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
183 static int eq_local_specializations (const void *, const void *);
184 static bool dependent_template_arg_p (tree);
185 static bool any_template_arguments_need_structural_equality_p (tree);
186 static bool dependent_type_p_r (tree);
187 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
188 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
189 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
190 static tree tsubst_decl (tree, tree, tsubst_flags_t);
191 static void perform_typedefs_access_check (tree tmpl, tree targs);
192 static void append_type_to_template_for_access_check_1 (tree, tree, tree);
193 static hashval_t iterative_hash_template_arg (tree arg, hashval_t val);
194 static bool primary_template_instantiation_p (const_tree);
196 /* Make the current scope suitable for access checking when we are
197 processing T. T can be FUNCTION_DECL for instantiated function
198 template, or VAR_DECL for static member variable (need by
199 instantiate_decl). */
202 push_access_scope (tree t)
204 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
205 || TREE_CODE (t) == VAR_DECL);
207 if (DECL_FRIEND_CONTEXT (t))
208 push_nested_class (DECL_FRIEND_CONTEXT (t));
209 else if (DECL_CLASS_SCOPE_P (t))
210 push_nested_class (DECL_CONTEXT (t));
212 push_to_top_level ();
214 if (TREE_CODE (t) == FUNCTION_DECL)
216 saved_access_scope = tree_cons
217 (NULL_TREE, current_function_decl, saved_access_scope);
218 current_function_decl = t;
222 /* Restore the scope set up by push_access_scope. T is the node we
226 pop_access_scope (tree t)
228 if (TREE_CODE (t) == FUNCTION_DECL)
230 current_function_decl = TREE_VALUE (saved_access_scope);
231 saved_access_scope = TREE_CHAIN (saved_access_scope);
234 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
237 pop_from_top_level ();
240 /* Do any processing required when DECL (a member template
241 declaration) is finished. Returns the TEMPLATE_DECL corresponding
242 to DECL, unless it is a specialization, in which case the DECL
243 itself is returned. */
246 finish_member_template_decl (tree decl)
248 if (decl == error_mark_node)
249 return error_mark_node;
251 gcc_assert (DECL_P (decl));
253 if (TREE_CODE (decl) == TYPE_DECL)
257 type = TREE_TYPE (decl);
258 if (type == error_mark_node)
259 return error_mark_node;
260 if (MAYBE_CLASS_TYPE_P (type)
261 && CLASSTYPE_TEMPLATE_INFO (type)
262 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
264 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
265 check_member_template (tmpl);
270 else if (TREE_CODE (decl) == FIELD_DECL)
271 error ("data member %qD cannot be a member template", decl);
272 else if (DECL_TEMPLATE_INFO (decl))
274 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
276 check_member_template (DECL_TI_TEMPLATE (decl));
277 return DECL_TI_TEMPLATE (decl);
283 error ("invalid member template declaration %qD", decl);
285 return error_mark_node;
288 /* Return the template info node corresponding to T, whatever T is. */
291 get_template_info (const_tree t)
293 tree tinfo = NULL_TREE;
295 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
296 tinfo = DECL_TEMPLATE_INFO (t);
298 if (!tinfo && TREE_CODE (t) == TYPE_DECL)
301 if (TAGGED_TYPE_P (t))
302 tinfo = TYPE_TEMPLATE_INFO (t);
307 /* Returns the template nesting level of the indicated class TYPE.
317 A<T>::B<U> has depth two, while A<T> has depth one.
318 Both A<T>::B<int> and A<int>::B<U> have depth one, if
319 they are instantiations, not specializations.
321 This function is guaranteed to return 0 if passed NULL_TREE so
322 that, for example, `template_class_depth (current_class_type)' is
326 template_class_depth (tree type)
331 type && TREE_CODE (type) != NAMESPACE_DECL;
332 type = (TREE_CODE (type) == FUNCTION_DECL)
333 ? CP_DECL_CONTEXT (type) : TYPE_CONTEXT (type))
335 tree tinfo = get_template_info (type);
337 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
338 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
345 /* Subroutine of maybe_begin_member_template_processing.
346 Returns true if processing DECL needs us to push template parms. */
349 inline_needs_template_parms (tree decl)
351 if (! DECL_TEMPLATE_INFO (decl))
354 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
355 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
358 /* Subroutine of maybe_begin_member_template_processing.
359 Push the template parms in PARMS, starting from LEVELS steps into the
360 chain, and ending at the beginning, since template parms are listed
364 push_inline_template_parms_recursive (tree parmlist, int levels)
366 tree parms = TREE_VALUE (parmlist);
370 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
372 ++processing_template_decl;
373 current_template_parms
374 = tree_cons (size_int (processing_template_decl),
375 parms, current_template_parms);
376 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
378 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
380 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
382 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
384 if (parm == error_mark_node)
387 gcc_assert (DECL_P (parm));
389 switch (TREE_CODE (parm))
398 /* Make a CONST_DECL as is done in process_template_parm.
399 It is ugly that we recreate this here; the original
400 version built in process_template_parm is no longer
402 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
403 CONST_DECL, DECL_NAME (parm),
405 DECL_ARTIFICIAL (decl) = 1;
406 TREE_CONSTANT (decl) = 1;
407 TREE_READONLY (decl) = 1;
408 DECL_INITIAL (decl) = DECL_INITIAL (parm);
409 SET_DECL_TEMPLATE_PARM_P (decl);
420 /* Restore the template parameter context for a member template or
421 a friend template defined in a class definition. */
424 maybe_begin_member_template_processing (tree decl)
429 if (inline_needs_template_parms (decl))
431 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
432 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
434 if (DECL_TEMPLATE_SPECIALIZATION (decl))
437 parms = TREE_CHAIN (parms);
440 push_inline_template_parms_recursive (parms, levels);
443 /* Remember how many levels of template parameters we pushed so that
444 we can pop them later. */
445 VEC_safe_push (int, heap, inline_parm_levels, levels);
448 /* Undo the effects of maybe_begin_member_template_processing. */
451 maybe_end_member_template_processing (void)
456 if (VEC_length (int, inline_parm_levels) == 0)
459 last = VEC_pop (int, inline_parm_levels);
460 for (i = 0; i < last; ++i)
462 --processing_template_decl;
463 current_template_parms = TREE_CHAIN (current_template_parms);
468 /* Return a new template argument vector which contains all of ARGS,
469 but has as its innermost set of arguments the EXTRA_ARGS. */
472 add_to_template_args (tree args, tree extra_args)
479 extra_depth = TMPL_ARGS_DEPTH (extra_args);
480 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
482 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
483 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
485 for (j = 1; j <= extra_depth; ++j, ++i)
486 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
491 /* Like add_to_template_args, but only the outermost ARGS are added to
492 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
493 (EXTRA_ARGS) levels are added. This function is used to combine
494 the template arguments from a partial instantiation with the
495 template arguments used to attain the full instantiation from the
496 partial instantiation. */
499 add_outermost_template_args (tree args, tree extra_args)
503 /* If there are more levels of EXTRA_ARGS than there are ARGS,
504 something very fishy is going on. */
505 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
507 /* If *all* the new arguments will be the EXTRA_ARGS, just return
509 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
512 /* For the moment, we make ARGS look like it contains fewer levels. */
513 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
515 new_args = add_to_template_args (args, extra_args);
517 /* Now, we restore ARGS to its full dimensions. */
518 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
523 /* Return the N levels of innermost template arguments from the ARGS. */
526 get_innermost_template_args (tree args, int n)
534 /* If N is 1, just return the innermost set of template arguments. */
536 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
538 /* If we're not removing anything, just return the arguments we were
540 extra_levels = TMPL_ARGS_DEPTH (args) - n;
541 gcc_assert (extra_levels >= 0);
542 if (extra_levels == 0)
545 /* Make a new set of arguments, not containing the outer arguments. */
546 new_args = make_tree_vec (n);
547 for (i = 1; i <= n; ++i)
548 SET_TMPL_ARGS_LEVEL (new_args, i,
549 TMPL_ARGS_LEVEL (args, i + extra_levels));
554 /* The inverse of get_innermost_template_args: Return all but the innermost
555 EXTRA_LEVELS levels of template arguments from the ARGS. */
558 strip_innermost_template_args (tree args, int extra_levels)
561 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
566 /* If N is 1, just return the outermost set of template arguments. */
568 return TMPL_ARGS_LEVEL (args, 1);
570 /* If we're not removing anything, just return the arguments we were
572 gcc_assert (extra_levels >= 0);
573 if (extra_levels == 0)
576 /* Make a new set of arguments, not containing the inner arguments. */
577 new_args = make_tree_vec (n);
578 for (i = 1; i <= n; ++i)
579 SET_TMPL_ARGS_LEVEL (new_args, i,
580 TMPL_ARGS_LEVEL (args, i));
585 /* We've got a template header coming up; push to a new level for storing
589 begin_template_parm_list (void)
591 /* We use a non-tag-transparent scope here, which causes pushtag to
592 put tags in this scope, rather than in the enclosing class or
593 namespace scope. This is the right thing, since we want
594 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
595 global template class, push_template_decl handles putting the
596 TEMPLATE_DECL into top-level scope. For a nested template class,
599 template <class T> struct S1 {
600 template <class T> struct S2 {};
603 pushtag contains special code to call pushdecl_with_scope on the
604 TEMPLATE_DECL for S2. */
605 begin_scope (sk_template_parms, NULL);
606 ++processing_template_decl;
607 ++processing_template_parmlist;
608 note_template_header (0);
611 /* This routine is called when a specialization is declared. If it is
612 invalid to declare a specialization here, an error is reported and
613 false is returned, otherwise this routine will return true. */
616 check_specialization_scope (void)
618 tree scope = current_scope ();
622 An explicit specialization shall be declared in the namespace of
623 which the template is a member, or, for member templates, in the
624 namespace of which the enclosing class or enclosing class
625 template is a member. An explicit specialization of a member
626 function, member class or static data member of a class template
627 shall be declared in the namespace of which the class template
629 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
631 error ("explicit specialization in non-namespace scope %qD", scope);
637 In an explicit specialization declaration for a member of a class
638 template or a member template that appears in namespace scope,
639 the member template and some of its enclosing class templates may
640 remain unspecialized, except that the declaration shall not
641 explicitly specialize a class member template if its enclosing
642 class templates are not explicitly specialized as well. */
643 if (current_template_parms)
645 error ("enclosing class templates are not explicitly specialized");
652 /* We've just seen template <>. */
655 begin_specialization (void)
657 begin_scope (sk_template_spec, NULL);
658 note_template_header (1);
659 return check_specialization_scope ();
662 /* Called at then end of processing a declaration preceded by
666 end_specialization (void)
669 reset_specialization ();
672 /* Any template <>'s that we have seen thus far are not referring to a
673 function specialization. */
676 reset_specialization (void)
678 processing_specialization = 0;
679 template_header_count = 0;
682 /* We've just seen a template header. If SPECIALIZATION is nonzero,
683 it was of the form template <>. */
686 note_template_header (int specialization)
688 processing_specialization = specialization;
689 template_header_count++;
692 /* We're beginning an explicit instantiation. */
695 begin_explicit_instantiation (void)
697 gcc_assert (!processing_explicit_instantiation);
698 processing_explicit_instantiation = true;
703 end_explicit_instantiation (void)
705 gcc_assert (processing_explicit_instantiation);
706 processing_explicit_instantiation = false;
709 /* An explicit specialization or partial specialization TMPL is being
710 declared. Check that the namespace in which the specialization is
711 occurring is permissible. Returns false iff it is invalid to
712 specialize TMPL in the current namespace. */
715 check_specialization_namespace (tree tmpl)
717 tree tpl_ns = decl_namespace_context (tmpl);
721 An explicit specialization shall be declared in the namespace of
722 which the template is a member, or, for member templates, in the
723 namespace of which the enclosing class or enclosing class
724 template is a member. An explicit specialization of a member
725 function, member class or static data member of a class template
726 shall be declared in the namespace of which the class template is
728 if (is_associated_namespace (current_namespace, tpl_ns))
729 /* Same or super-using namespace. */
733 permerror (input_location, "specialization of %qD in different namespace", tmpl);
734 permerror (input_location, " from definition of %q+#D", tmpl);
739 /* SPEC is an explicit instantiation. Check that it is valid to
740 perform this explicit instantiation in the current namespace. */
743 check_explicit_instantiation_namespace (tree spec)
747 /* DR 275: An explicit instantiation shall appear in an enclosing
748 namespace of its template. */
749 ns = decl_namespace_context (spec);
750 if (!is_ancestor (current_namespace, ns))
751 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
752 "(which does not enclose namespace %qD)",
753 spec, current_namespace, ns);
756 /* The TYPE is being declared. If it is a template type, that means it
757 is a partial specialization. Do appropriate error-checking. */
760 maybe_process_partial_specialization (tree type)
764 if (type == error_mark_node)
765 return error_mark_node;
767 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
769 error ("name of class shadows template template parameter %qD",
771 return error_mark_node;
774 context = TYPE_CONTEXT (type);
776 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
778 /* This is for ordinary explicit specialization and partial
779 specialization of a template class such as:
781 template <> class C<int>;
785 template <class T> class C<T*>;
787 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
789 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
790 && !COMPLETE_TYPE_P (type))
792 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
793 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
794 if (processing_template_decl)
796 if (push_template_decl (TYPE_MAIN_DECL (type))
798 return error_mark_node;
801 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
802 error ("specialization of %qT after instantiation", type);
804 else if (CLASS_TYPE_P (type)
805 && !CLASSTYPE_USE_TEMPLATE (type)
806 && CLASSTYPE_TEMPLATE_INFO (type)
807 && context && CLASS_TYPE_P (context)
808 && CLASSTYPE_TEMPLATE_INFO (context))
810 /* This is for an explicit specialization of member class
811 template according to [temp.expl.spec/18]:
813 template <> template <class U> class C<int>::D;
815 The context `C<int>' must be an implicit instantiation.
816 Otherwise this is just a member class template declared
819 template <> class C<int> { template <class U> class D; };
820 template <> template <class U> class C<int>::D;
822 In the first case, `C<int>::D' is a specialization of `C<T>::D'
823 while in the second case, `C<int>::D' is a primary template
824 and `C<T>::D' may not exist. */
826 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
827 && !COMPLETE_TYPE_P (type))
830 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
832 if (current_namespace
833 != decl_namespace_context (tmpl))
835 permerror (input_location, "specializing %q#T in different namespace", type);
836 permerror (input_location, " from definition of %q+#D", tmpl);
839 /* Check for invalid specialization after instantiation:
841 template <> template <> class C<int>::D<int>;
842 template <> template <class U> class C<int>::D; */
844 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
845 t; t = TREE_CHAIN (t))
847 tree inst = TREE_VALUE (t);
848 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
850 /* We already have a full specialization of this partial
851 instantiation. Reassign it to the new member
852 specialization template. */
856 elt.tmpl = most_general_template (tmpl);
857 elt.args = CLASSTYPE_TI_ARGS (inst);
860 htab_remove_elt (type_specializations, &elt);
863 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
865 slot = (spec_entry **)
866 htab_find_slot (type_specializations, &elt, INSERT);
867 *slot = GGC_NEW (spec_entry);
870 else if (COMPLETE_TYPE_P (inst) || TYPE_BEING_DEFINED (inst))
871 /* But if we've had an implicit instantiation, that's a
872 problem ([temp.expl.spec]/6). */
873 error ("specialization %qT after instantiation %qT",
877 /* Mark TYPE as a specialization. And as a result, we only
878 have one level of template argument for the innermost
880 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
881 CLASSTYPE_TI_ARGS (type)
882 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
885 else if (processing_specialization)
887 error ("explicit specialization of non-template %qT", type);
888 return error_mark_node;
894 /* Returns nonzero if we can optimize the retrieval of specializations
895 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
896 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
899 optimize_specialization_lookup_p (tree tmpl)
901 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
902 && DECL_CLASS_SCOPE_P (tmpl)
903 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
905 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
906 /* The optimized lookup depends on the fact that the
907 template arguments for the member function template apply
908 purely to the containing class, which is not true if the
909 containing class is an explicit or partial
911 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
912 && !DECL_MEMBER_TEMPLATE_P (tmpl)
913 && !DECL_CONV_FN_P (tmpl)
914 /* It is possible to have a template that is not a member
915 template and is not a member of a template class:
917 template <typename T>
918 struct S { friend A::f(); };
920 Here, the friend function is a template, but the context does
921 not have template information. The optimized lookup relies
922 on having ARGS be the template arguments for both the class
923 and the function template. */
924 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
927 /* Retrieve the specialization (in the sense of [temp.spec] - a
928 specialization is either an instantiation or an explicit
929 specialization) of TMPL for the given template ARGS. If there is
930 no such specialization, return NULL_TREE. The ARGS are a vector of
931 arguments, or a vector of vectors of arguments, in the case of
932 templates with more than one level of parameters.
934 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
935 then we search for a partial specialization matching ARGS. This
936 parameter is ignored if TMPL is not a class template. */
939 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
941 if (args == error_mark_node)
944 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
946 /* There should be as many levels of arguments as there are
947 levels of parameters. */
948 gcc_assert (TMPL_ARGS_DEPTH (args)
949 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
951 if (optimize_specialization_lookup_p (tmpl))
954 tree class_specialization;
955 VEC(tree,gc) *methods;
959 /* The template arguments actually apply to the containing
960 class. Find the class specialization with those
962 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
964 = retrieve_specialization (class_template, args, 0);
965 if (!class_specialization)
967 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
968 for the specialization. */
969 idx = class_method_index_for_fn (class_specialization, tmpl);
972 /* Iterate through the methods with the indicated name, looking
973 for the one that has an instance of TMPL. */
974 methods = CLASSTYPE_METHOD_VEC (class_specialization);
975 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
977 tree fn = OVL_CURRENT (fns);
978 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
979 /* using-declarations can add base methods to the method vec,
980 and we don't want those here. */
981 && DECL_CONTEXT (fn) == class_specialization)
990 htab_t specializations;
994 elt.spec = NULL_TREE;
996 if (DECL_CLASS_TEMPLATE_P (tmpl))
997 specializations = type_specializations;
999 specializations = decl_specializations;
1002 hash = hash_specialization (&elt);
1003 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1011 /* Like retrieve_specialization, but for local declarations. */
1014 retrieve_local_specialization (tree tmpl)
1018 if (local_specializations == NULL)
1021 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1022 htab_hash_pointer (tmpl));
1023 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1026 /* Returns nonzero iff DECL is a specialization of TMPL. */
1029 is_specialization_of (tree decl, tree tmpl)
1033 if (TREE_CODE (decl) == FUNCTION_DECL)
1037 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1043 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1045 for (t = TREE_TYPE (decl);
1047 t = CLASSTYPE_USE_TEMPLATE (t)
1048 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1049 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1056 /* Returns nonzero iff DECL is a specialization of friend declaration
1057 FRIEND_DECL according to [temp.friend]. */
1060 is_specialization_of_friend (tree decl, tree friend_decl)
1062 bool need_template = true;
1065 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1066 || TREE_CODE (decl) == TYPE_DECL);
1068 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1069 of a template class, we want to check if DECL is a specialization
1071 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1072 && DECL_TEMPLATE_INFO (friend_decl)
1073 && !DECL_USE_TEMPLATE (friend_decl))
1075 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1076 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1077 need_template = false;
1079 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1080 && !PRIMARY_TEMPLATE_P (friend_decl))
1081 need_template = false;
1083 /* There is nothing to do if this is not a template friend. */
1084 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1087 if (is_specialization_of (decl, friend_decl))
1091 A member of a class template may be declared to be a friend of a
1092 non-template class. In this case, the corresponding member of
1093 every specialization of the class template is a friend of the
1094 class granting friendship.
1096 For example, given a template friend declaration
1098 template <class T> friend void A<T>::f();
1100 the member function below is considered a friend
1102 template <> struct A<int> {
1106 For this type of template friend, TEMPLATE_DEPTH below will be
1107 nonzero. To determine if DECL is a friend of FRIEND, we first
1108 check if the enclosing class is a specialization of another. */
1110 template_depth = template_class_depth (DECL_CONTEXT (friend_decl));
1112 && DECL_CLASS_SCOPE_P (decl)
1113 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1114 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1116 /* Next, we check the members themselves. In order to handle
1117 a few tricky cases, such as when FRIEND_DECL's are
1119 template <class T> friend void A<T>::g(T t);
1120 template <class T> template <T t> friend void A<T>::h();
1124 void A<int>::g(int);
1125 template <int> void A<int>::h();
1127 we need to figure out ARGS, the template arguments from
1128 the context of DECL. This is required for template substitution
1129 of `T' in the function parameter of `g' and template parameter
1130 of `h' in the above examples. Here ARGS corresponds to `int'. */
1132 tree context = DECL_CONTEXT (decl);
1133 tree args = NULL_TREE;
1134 int current_depth = 0;
1136 while (current_depth < template_depth)
1138 if (CLASSTYPE_TEMPLATE_INFO (context))
1140 if (current_depth == 0)
1141 args = TYPE_TI_ARGS (context);
1143 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1146 context = TYPE_CONTEXT (context);
1149 if (TREE_CODE (decl) == FUNCTION_DECL)
1154 tree friend_args_type;
1155 tree decl_args_type;
1157 /* Make sure that both DECL and FRIEND_DECL are templates or
1159 is_template = DECL_TEMPLATE_INFO (decl)
1160 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1161 if (need_template ^ is_template)
1163 else if (is_template)
1165 /* If both are templates, check template parameter list. */
1167 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1169 if (!comp_template_parms
1170 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1174 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1177 decl_type = TREE_TYPE (decl);
1179 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1180 tf_none, NULL_TREE);
1181 if (friend_type == error_mark_node)
1184 /* Check if return types match. */
1185 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1188 /* Check if function parameter types match, ignoring the
1189 `this' parameter. */
1190 friend_args_type = TYPE_ARG_TYPES (friend_type);
1191 decl_args_type = TYPE_ARG_TYPES (decl_type);
1192 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1193 friend_args_type = TREE_CHAIN (friend_args_type);
1194 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1195 decl_args_type = TREE_CHAIN (decl_args_type);
1197 return compparms (decl_args_type, friend_args_type);
1201 /* DECL is a TYPE_DECL */
1203 tree decl_type = TREE_TYPE (decl);
1205 /* Make sure that both DECL and FRIEND_DECL are templates or
1208 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1209 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1211 if (need_template ^ is_template)
1213 else if (is_template)
1216 /* If both are templates, check the name of the two
1217 TEMPLATE_DECL's first because is_friend didn't. */
1218 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1219 != DECL_NAME (friend_decl))
1222 /* Now check template parameter list. */
1224 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1226 return comp_template_parms
1227 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1231 return (DECL_NAME (decl)
1232 == DECL_NAME (friend_decl));
1238 /* Register the specialization SPEC as a specialization of TMPL with
1239 the indicated ARGS. IS_FRIEND indicates whether the specialization
1240 is actually just a friend declaration. Returns SPEC, or an
1241 equivalent prior declaration, if available. */
1244 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1248 spec_entry **slot = NULL;
1251 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1253 if (TREE_CODE (spec) == FUNCTION_DECL
1254 && uses_template_parms (DECL_TI_ARGS (spec)))
1255 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1256 register it; we want the corresponding TEMPLATE_DECL instead.
1257 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1258 the more obvious `uses_template_parms (spec)' to avoid problems
1259 with default function arguments. In particular, given
1260 something like this:
1262 template <class T> void f(T t1, T t = T())
1264 the default argument expression is not substituted for in an
1265 instantiation unless and until it is actually needed. */
1268 if (optimize_specialization_lookup_p (tmpl))
1269 /* We don't put these specializations in the hash table, but we might
1270 want to give an error about a mismatch. */
1271 fn = retrieve_specialization (tmpl, args, 0);
1279 hash = hash_specialization (&elt);
1281 slot = (spec_entry **)
1282 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1289 /* We can sometimes try to re-register a specialization that we've
1290 already got. In particular, regenerate_decl_from_template calls
1291 duplicate_decls which will update the specialization list. But,
1292 we'll still get called again here anyhow. It's more convenient
1293 to simply allow this than to try to prevent it. */
1296 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1298 if (DECL_TEMPLATE_INSTANTIATION (fn))
1300 if (DECL_ODR_USED (fn)
1301 || DECL_EXPLICIT_INSTANTIATION (fn))
1303 error ("specialization of %qD after instantiation",
1305 return error_mark_node;
1310 /* This situation should occur only if the first
1311 specialization is an implicit instantiation, the
1312 second is an explicit specialization, and the
1313 implicit instantiation has not yet been used. That
1314 situation can occur if we have implicitly
1315 instantiated a member function and then specialized
1318 We can also wind up here if a friend declaration that
1319 looked like an instantiation turns out to be a
1322 template <class T> void foo(T);
1323 class S { friend void foo<>(int) };
1324 template <> void foo(int);
1326 We transform the existing DECL in place so that any
1327 pointers to it become pointers to the updated
1330 If there was a definition for the template, but not
1331 for the specialization, we want this to look as if
1332 there were no definition, and vice versa. */
1333 DECL_INITIAL (fn) = NULL_TREE;
1334 duplicate_decls (spec, fn, is_friend);
1335 /* The call to duplicate_decls will have applied
1338 An explicit specialization of a function template
1339 is inline only if it is explicitly declared to be,
1340 and independently of whether its function template
1343 to the primary function; now copy the inline bits to
1344 the various clones. */
1345 FOR_EACH_CLONE (clone, fn)
1346 DECL_DECLARED_INLINE_P (clone)
1347 = DECL_DECLARED_INLINE_P (fn);
1348 check_specialization_namespace (fn);
1353 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1355 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1356 /* Dup decl failed, but this is a new definition. Set the
1357 line number so any errors match this new
1359 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1365 return duplicate_decls (spec, fn, is_friend);
1367 /* A specialization must be declared in the same namespace as the
1368 template it is specializing. */
1369 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1370 && !check_specialization_namespace (tmpl))
1371 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1373 if (!optimize_specialization_lookup_p (tmpl))
1375 gcc_assert (tmpl && args && spec);
1376 *slot = GGC_NEW (spec_entry);
1378 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1379 && PRIMARY_TEMPLATE_P (tmpl)
1380 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1381 /* TMPL is a forward declaration of a template function; keep a list
1382 of all specializations in case we need to reassign them to a friend
1383 template later in tsubst_friend_function. */
1384 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1385 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1391 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1392 TMPL and ARGS members, ignores SPEC. */
1395 eq_specializations (const void *p1, const void *p2)
1397 const spec_entry *e1 = (const spec_entry *)p1;
1398 const spec_entry *e2 = (const spec_entry *)p2;
1400 return (e1->tmpl == e2->tmpl
1401 && comp_template_args (e1->args, e2->args));
1404 /* Returns a hash for a template TMPL and template arguments ARGS. */
1407 hash_tmpl_and_args (tree tmpl, tree args)
1409 hashval_t val = DECL_UID (tmpl);
1410 return iterative_hash_template_arg (args, val);
1413 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1417 hash_specialization (const void *p)
1419 const spec_entry *e = (const spec_entry *)p;
1420 return hash_tmpl_and_args (e->tmpl, e->args);
1423 /* Recursively calculate a hash value for a template argument ARG, for use
1424 in the hash tables of template specializations. */
1427 iterative_hash_template_arg (tree arg, hashval_t val)
1429 unsigned HOST_WIDE_INT i;
1430 enum tree_code code;
1433 if (arg == NULL_TREE)
1434 return iterative_hash_object (arg, val);
1439 code = TREE_CODE (arg);
1440 tclass = TREE_CODE_CLASS (code);
1442 val = iterative_hash_object (code, val);
1449 case IDENTIFIER_NODE:
1450 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1454 int i, len = TREE_VEC_LENGTH (arg);
1455 for (i = 0; i < len; ++i)
1456 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1460 case TYPE_PACK_EXPANSION:
1461 case EXPR_PACK_EXPANSION:
1462 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1464 case ARGUMENT_PACK_SELECT:
1465 /* We can get one of these when re-hashing a previous entry in the middle
1466 of substituting into a pack expansion. Just look through it... */
1467 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1468 /* ...and fall through. */
1469 case TYPE_ARGUMENT_PACK:
1470 case NONTYPE_ARGUMENT_PACK:
1471 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1474 for (; arg; arg = TREE_CHAIN (arg))
1475 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1479 for (; arg; arg = OVL_CHAIN (arg))
1480 val = iterative_hash_template_arg (OVL_FUNCTION (arg), val);
1486 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1488 val = iterative_hash_template_arg (field, val);
1489 val = iterative_hash_template_arg (value, val);
1495 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1496 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1499 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1502 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1503 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1505 case TEMPLATE_PARM_INDEX:
1506 val = iterative_hash_template_arg
1507 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1508 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1509 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1512 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1513 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1514 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1517 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1519 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1523 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1524 code = TREE_CODE (TREE_OPERAND (arg, 1));
1525 val = iterative_hash_object (code, val);
1526 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1532 if (TYPE_CANONICAL (arg))
1533 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1535 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1536 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1537 /* Otherwise just compare the types during lookup. */
1540 case tcc_declaration:
1542 return iterative_hash_expr (arg, val);
1545 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1547 unsigned n = TREE_OPERAND_LENGTH (arg);
1548 for (i = 0; i < n; ++i)
1549 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1558 /* Unregister the specialization SPEC as a specialization of TMPL.
1559 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1560 if the SPEC was listed as a specialization of TMPL.
1562 Note that SPEC has been ggc_freed, so we can't look inside it. */
1565 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1570 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1571 elt.args = TI_ARGS (tinfo);
1572 elt.spec = NULL_TREE;
1574 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1577 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1578 gcc_assert (new_spec != NULL_TREE);
1579 (*slot)->spec = new_spec;
1586 /* Compare an entry in the local specializations hash table P1 (which
1587 is really a pointer to a TREE_LIST) with P2 (which is really a
1591 eq_local_specializations (const void *p1, const void *p2)
1593 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1596 /* Hash P1, an entry in the local specializations table. */
1599 hash_local_specialization (const void* p1)
1601 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1604 /* Like register_specialization, but for local declarations. We are
1605 registering SPEC, an instantiation of TMPL. */
1608 register_local_specialization (tree spec, tree tmpl)
1612 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1613 htab_hash_pointer (tmpl), INSERT);
1614 *slot = build_tree_list (spec, tmpl);
1617 /* TYPE is a class type. Returns true if TYPE is an explicitly
1618 specialized class. */
1621 explicit_class_specialization_p (tree type)
1623 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1625 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1628 /* Print the list of candidate FNS in an error message. */
1631 print_candidates (tree fns)
1635 const char *str = "candidates are:";
1637 for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
1641 for (f = TREE_VALUE (fn); f; f = OVL_NEXT (f))
1642 error ("%s %+#D", str, OVL_CURRENT (f));
1647 /* Returns the template (one of the functions given by TEMPLATE_ID)
1648 which can be specialized to match the indicated DECL with the
1649 explicit template args given in TEMPLATE_ID. The DECL may be
1650 NULL_TREE if none is available. In that case, the functions in
1651 TEMPLATE_ID are non-members.
1653 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1654 specialization of a member template.
1656 The TEMPLATE_COUNT is the number of references to qualifying
1657 template classes that appeared in the name of the function. See
1658 check_explicit_specialization for a more accurate description.
1660 TSK indicates what kind of template declaration (if any) is being
1661 declared. TSK_TEMPLATE indicates that the declaration given by
1662 DECL, though a FUNCTION_DECL, has template parameters, and is
1663 therefore a template function.
1665 The template args (those explicitly specified and those deduced)
1666 are output in a newly created vector *TARGS_OUT.
1668 If it is impossible to determine the result, an error message is
1669 issued. The error_mark_node is returned to indicate failure. */
1672 determine_specialization (tree template_id,
1675 int need_member_template,
1681 tree explicit_targs;
1682 tree candidates = NULL_TREE;
1683 /* A TREE_LIST of templates of which DECL may be a specialization.
1684 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1685 corresponding TREE_PURPOSE is the set of template arguments that,
1686 when used to instantiate the template, would produce a function
1687 with the signature of DECL. */
1688 tree templates = NULL_TREE;
1690 struct cp_binding_level *b;
1692 *targs_out = NULL_TREE;
1694 if (template_id == error_mark_node || decl == error_mark_node)
1695 return error_mark_node;
1697 fns = TREE_OPERAND (template_id, 0);
1698 explicit_targs = TREE_OPERAND (template_id, 1);
1700 if (fns == error_mark_node)
1701 return error_mark_node;
1703 /* Check for baselinks. */
1704 if (BASELINK_P (fns))
1705 fns = BASELINK_FUNCTIONS (fns);
1707 if (!is_overloaded_fn (fns))
1709 error ("%qD is not a function template", fns);
1710 return error_mark_node;
1713 /* Count the number of template headers specified for this
1716 for (b = current_binding_level;
1717 b->kind == sk_template_parms;
1721 for (; fns; fns = OVL_NEXT (fns))
1723 tree fn = OVL_CURRENT (fns);
1725 if (TREE_CODE (fn) == TEMPLATE_DECL)
1727 tree decl_arg_types;
1730 /* In case of explicit specialization, we need to check if
1731 the number of template headers appearing in the specialization
1732 is correct. This is usually done in check_explicit_specialization,
1733 but the check done there cannot be exhaustive when specializing
1734 member functions. Consider the following code:
1736 template <> void A<int>::f(int);
1737 template <> template <> void A<int>::f(int);
1739 Assuming that A<int> is not itself an explicit specialization
1740 already, the first line specializes "f" which is a non-template
1741 member function, whilst the second line specializes "f" which
1742 is a template member function. So both lines are syntactically
1743 correct, and check_explicit_specialization does not reject
1746 Here, we can do better, as we are matching the specialization
1747 against the declarations. We count the number of template
1748 headers, and we check if they match TEMPLATE_COUNT + 1
1749 (TEMPLATE_COUNT is the number of qualifying template classes,
1750 plus there must be another header for the member template
1753 Notice that if header_count is zero, this is not a
1754 specialization but rather a template instantiation, so there
1755 is no check we can perform here. */
1756 if (header_count && header_count != template_count + 1)
1759 /* Check that the number of template arguments at the
1760 innermost level for DECL is the same as for FN. */
1761 if (current_binding_level->kind == sk_template_parms
1762 && !current_binding_level->explicit_spec_p
1763 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1764 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1765 (current_template_parms))))
1768 /* DECL might be a specialization of FN. */
1769 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1770 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1772 /* For a non-static member function, we need to make sure
1773 that the const qualification is the same. Since
1774 get_bindings does not try to merge the "this" parameter,
1775 we must do the comparison explicitly. */
1776 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1777 && !same_type_p (TREE_VALUE (fn_arg_types),
1778 TREE_VALUE (decl_arg_types)))
1781 /* Skip the "this" parameter and, for constructors of
1782 classes with virtual bases, the VTT parameter. A
1783 full specialization of a constructor will have a VTT
1784 parameter, but a template never will. */
1786 = skip_artificial_parms_for (decl, decl_arg_types);
1788 = skip_artificial_parms_for (fn, fn_arg_types);
1790 /* Check that the number of function parameters matches.
1792 template <class T> void f(int i = 0);
1793 template <> void f<int>();
1794 The specialization f<int> is invalid but is not caught
1795 by get_bindings below. */
1796 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1799 /* Function templates cannot be specializations; there are
1800 no partial specializations of functions. Therefore, if
1801 the type of DECL does not match FN, there is no
1803 if (tsk == tsk_template)
1805 if (compparms (fn_arg_types, decl_arg_types))
1806 candidates = tree_cons (NULL_TREE, fn, candidates);
1810 /* See whether this function might be a specialization of this
1812 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1815 /* We cannot deduce template arguments that when used to
1816 specialize TMPL will produce DECL. */
1819 /* Save this template, and the arguments deduced. */
1820 templates = tree_cons (targs, fn, templates);
1822 else if (need_member_template)
1823 /* FN is an ordinary member function, and we need a
1824 specialization of a member template. */
1826 else if (TREE_CODE (fn) != FUNCTION_DECL)
1827 /* We can get IDENTIFIER_NODEs here in certain erroneous
1830 else if (!DECL_FUNCTION_MEMBER_P (fn))
1831 /* This is just an ordinary non-member function. Nothing can
1832 be a specialization of that. */
1834 else if (DECL_ARTIFICIAL (fn))
1835 /* Cannot specialize functions that are created implicitly. */
1839 tree decl_arg_types;
1841 /* This is an ordinary member function. However, since
1842 we're here, we can assume it's enclosing class is a
1843 template class. For example,
1845 template <typename T> struct S { void f(); };
1846 template <> void S<int>::f() {}
1848 Here, S<int>::f is a non-template, but S<int> is a
1849 template class. If FN has the same type as DECL, we
1850 might be in business. */
1852 if (!DECL_TEMPLATE_INFO (fn))
1853 /* Its enclosing class is an explicit specialization
1854 of a template class. This is not a candidate. */
1857 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1858 TREE_TYPE (TREE_TYPE (fn))))
1859 /* The return types differ. */
1862 /* Adjust the type of DECL in case FN is a static member. */
1863 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1864 if (DECL_STATIC_FUNCTION_P (fn)
1865 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1866 decl_arg_types = TREE_CHAIN (decl_arg_types);
1868 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1871 candidates = tree_cons (NULL_TREE, fn, candidates);
1875 if (templates && TREE_CHAIN (templates))
1881 It is possible for a specialization with a given function
1882 signature to be instantiated from more than one function
1883 template. In such cases, explicit specification of the
1884 template arguments must be used to uniquely identify the
1885 function template specialization being specialized.
1887 Note that here, there's no suggestion that we're supposed to
1888 determine which of the candidate templates is most
1889 specialized. However, we, also have:
1893 Partial ordering of overloaded function template
1894 declarations is used in the following contexts to select
1895 the function template to which a function template
1896 specialization refers:
1898 -- when an explicit specialization refers to a function
1901 So, we do use the partial ordering rules, at least for now.
1902 This extension can only serve to make invalid programs valid,
1903 so it's safe. And, there is strong anecdotal evidence that
1904 the committee intended the partial ordering rules to apply;
1905 the EDG front end has that behavior, and John Spicer claims
1906 that the committee simply forgot to delete the wording in
1907 [temp.expl.spec]. */
1908 tree tmpl = most_specialized_instantiation (templates);
1909 if (tmpl != error_mark_node)
1912 TREE_CHAIN (templates) = NULL_TREE;
1916 if (templates == NULL_TREE && candidates == NULL_TREE)
1918 error ("template-id %qD for %q+D does not match any template "
1919 "declaration", template_id, decl);
1920 return error_mark_node;
1922 else if ((templates && TREE_CHAIN (templates))
1923 || (candidates && TREE_CHAIN (candidates))
1924 || (templates && candidates))
1926 error ("ambiguous template specialization %qD for %q+D",
1928 chainon (candidates, templates);
1929 print_candidates (candidates);
1930 return error_mark_node;
1933 /* We have one, and exactly one, match. */
1936 tree fn = TREE_VALUE (candidates);
1937 *targs_out = copy_node (DECL_TI_ARGS (fn));
1938 /* DECL is a re-declaration or partial instantiation of a template
1940 if (TREE_CODE (fn) == TEMPLATE_DECL)
1942 /* It was a specialization of an ordinary member function in a
1944 return DECL_TI_TEMPLATE (fn);
1947 /* It was a specialization of a template. */
1948 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1949 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1951 *targs_out = copy_node (targs);
1952 SET_TMPL_ARGS_LEVEL (*targs_out,
1953 TMPL_ARGS_DEPTH (*targs_out),
1954 TREE_PURPOSE (templates));
1957 *targs_out = TREE_PURPOSE (templates);
1958 return TREE_VALUE (templates);
1961 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1962 but with the default argument values filled in from those in the
1966 copy_default_args_to_explicit_spec_1 (tree spec_types,
1969 tree new_spec_types;
1974 if (spec_types == void_list_node)
1975 return void_list_node;
1977 /* Substitute into the rest of the list. */
1979 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
1980 TREE_CHAIN (tmpl_types));
1982 /* Add the default argument for this parameter. */
1983 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
1984 TREE_VALUE (spec_types),
1988 /* DECL is an explicit specialization. Replicate default arguments
1989 from the template it specializes. (That way, code like:
1991 template <class T> void f(T = 3);
1992 template <> void f(double);
1995 works, as required.) An alternative approach would be to look up
1996 the correct default arguments at the call-site, but this approach
1997 is consistent with how implicit instantiations are handled. */
2000 copy_default_args_to_explicit_spec (tree decl)
2005 tree new_spec_types;
2009 tree object_type = NULL_TREE;
2010 tree in_charge = NULL_TREE;
2011 tree vtt = NULL_TREE;
2013 /* See if there's anything we need to do. */
2014 tmpl = DECL_TI_TEMPLATE (decl);
2015 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2016 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2017 if (TREE_PURPOSE (t))
2022 old_type = TREE_TYPE (decl);
2023 spec_types = TYPE_ARG_TYPES (old_type);
2025 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2027 /* Remove the this pointer, but remember the object's type for
2029 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2030 spec_types = TREE_CHAIN (spec_types);
2031 tmpl_types = TREE_CHAIN (tmpl_types);
2033 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2035 /* DECL may contain more parameters than TMPL due to the extra
2036 in-charge parameter in constructors and destructors. */
2037 in_charge = spec_types;
2038 spec_types = TREE_CHAIN (spec_types);
2040 if (DECL_HAS_VTT_PARM_P (decl))
2043 spec_types = TREE_CHAIN (spec_types);
2047 /* Compute the merged default arguments. */
2049 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2051 /* Compute the new FUNCTION_TYPE. */
2055 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2060 /* Put the in-charge parameter back. */
2061 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2062 TREE_VALUE (in_charge),
2065 new_type = build_method_type_directly (object_type,
2066 TREE_TYPE (old_type),
2070 new_type = build_function_type (TREE_TYPE (old_type),
2072 new_type = cp_build_type_attribute_variant (new_type,
2073 TYPE_ATTRIBUTES (old_type));
2074 new_type = build_exception_variant (new_type,
2075 TYPE_RAISES_EXCEPTIONS (old_type));
2076 TREE_TYPE (decl) = new_type;
2079 /* Check to see if the function just declared, as indicated in
2080 DECLARATOR, and in DECL, is a specialization of a function
2081 template. We may also discover that the declaration is an explicit
2082 instantiation at this point.
2084 Returns DECL, or an equivalent declaration that should be used
2085 instead if all goes well. Issues an error message if something is
2086 amiss. Returns error_mark_node if the error is not easily
2089 FLAGS is a bitmask consisting of the following flags:
2091 2: The function has a definition.
2092 4: The function is a friend.
2094 The TEMPLATE_COUNT is the number of references to qualifying
2095 template classes that appeared in the name of the function. For
2098 template <class T> struct S { void f(); };
2101 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2102 classes are not counted in the TEMPLATE_COUNT, so that in
2104 template <class T> struct S {};
2105 template <> struct S<int> { void f(); }
2106 template <> void S<int>::f();
2108 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2109 invalid; there should be no template <>.)
2111 If the function is a specialization, it is marked as such via
2112 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2113 is set up correctly, and it is added to the list of specializations
2114 for that template. */
2117 check_explicit_specialization (tree declarator,
2122 int have_def = flags & 2;
2123 int is_friend = flags & 4;
2124 int specialization = 0;
2125 int explicit_instantiation = 0;
2126 int member_specialization = 0;
2127 tree ctype = DECL_CLASS_CONTEXT (decl);
2128 tree dname = DECL_NAME (decl);
2133 if (!processing_specialization)
2136 tsk = tsk_excessive_parms;
2139 tsk = current_tmpl_spec_kind (template_count);
2144 if (processing_specialization)
2147 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2149 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2152 /* This could be something like:
2154 template <class T> void f(T);
2155 class S { friend void f<>(int); } */
2159 /* This case handles bogus declarations like template <>
2160 template <class T> void f<int>(); */
2162 error ("template-id %qD in declaration of primary template",
2169 case tsk_invalid_member_spec:
2170 /* The error has already been reported in
2171 check_specialization_scope. */
2172 return error_mark_node;
2174 case tsk_invalid_expl_inst:
2175 error ("template parameter list used in explicit instantiation");
2181 error ("definition provided for explicit instantiation");
2183 explicit_instantiation = 1;
2186 case tsk_excessive_parms:
2187 case tsk_insufficient_parms:
2188 if (tsk == tsk_excessive_parms)
2189 error ("too many template parameter lists in declaration of %qD",
2191 else if (template_header_count)
2192 error("too few template parameter lists in declaration of %qD", decl);
2194 error("explicit specialization of %qD must be introduced by "
2195 "%<template <>%>", decl);
2199 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2201 member_specialization = 1;
2207 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2209 /* This case handles bogus declarations like template <>
2210 template <class T> void f<int>(); */
2212 if (uses_template_parms (declarator))
2213 error ("function template partial specialization %qD "
2214 "is not allowed", declarator);
2216 error ("template-id %qD in declaration of primary template",
2221 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2222 /* This is a specialization of a member template, without
2223 specialization the containing class. Something like:
2225 template <class T> struct S {
2226 template <class U> void f (U);
2228 template <> template <class U> void S<int>::f(U) {}
2230 That's a specialization -- but of the entire template. */
2238 if (specialization || member_specialization)
2240 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2241 for (; t; t = TREE_CHAIN (t))
2242 if (TREE_PURPOSE (t))
2244 permerror (input_location,
2245 "default argument specified in explicit specialization");
2250 if (specialization || member_specialization || explicit_instantiation)
2252 tree tmpl = NULL_TREE;
2253 tree targs = NULL_TREE;
2255 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2256 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2260 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2265 /* If there is no class context, the explicit instantiation
2266 must be at namespace scope. */
2267 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2269 /* Find the namespace binding, using the declaration
2271 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2273 if (fns == error_mark_node || !is_overloaded_fn (fns))
2275 error ("%qD is not a template function", dname);
2276 fns = error_mark_node;
2280 tree fn = OVL_CURRENT (fns);
2281 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2282 CP_DECL_CONTEXT (fn)))
2283 error ("%qD is not declared in %qD",
2284 decl, current_namespace);
2288 declarator = lookup_template_function (fns, NULL_TREE);
2291 if (declarator == error_mark_node)
2292 return error_mark_node;
2294 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2296 if (!explicit_instantiation)
2297 /* A specialization in class scope. This is invalid,
2298 but the error will already have been flagged by
2299 check_specialization_scope. */
2300 return error_mark_node;
2303 /* It's not valid to write an explicit instantiation in
2306 class C { template void f(); }
2308 This case is caught by the parser. However, on
2311 template class C { void f(); };
2313 (which is invalid) we can get here. The error will be
2320 else if (ctype != NULL_TREE
2321 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2324 /* Find the list of functions in ctype that have the same
2325 name as the declared function. */
2326 tree name = TREE_OPERAND (declarator, 0);
2327 tree fns = NULL_TREE;
2330 if (constructor_name_p (name, ctype))
2332 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2334 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2335 : !CLASSTYPE_DESTRUCTORS (ctype))
2337 /* From [temp.expl.spec]:
2339 If such an explicit specialization for the member
2340 of a class template names an implicitly-declared
2341 special member function (clause _special_), the
2342 program is ill-formed.
2344 Similar language is found in [temp.explicit]. */
2345 error ("specialization of implicitly-declared special member function");
2346 return error_mark_node;
2349 name = is_constructor ? ctor_identifier : dtor_identifier;
2352 if (!DECL_CONV_FN_P (decl))
2354 idx = lookup_fnfields_1 (ctype, name);
2356 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2360 VEC(tree,gc) *methods;
2363 /* For a type-conversion operator, we cannot do a
2364 name-based lookup. We might be looking for `operator
2365 int' which will be a specialization of `operator T'.
2366 So, we find *all* the conversion operators, and then
2367 select from them. */
2370 methods = CLASSTYPE_METHOD_VEC (ctype);
2372 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2373 VEC_iterate (tree, methods, idx, ovl);
2376 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2377 /* There are no more conversion functions. */
2380 /* Glue all these conversion functions together
2381 with those we already have. */
2382 for (; ovl; ovl = OVL_NEXT (ovl))
2383 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2387 if (fns == NULL_TREE)
2389 error ("no member function %qD declared in %qT", name, ctype);
2390 return error_mark_node;
2393 TREE_OPERAND (declarator, 0) = fns;
2396 /* Figure out what exactly is being specialized at this point.
2397 Note that for an explicit instantiation, even one for a
2398 member function, we cannot tell apriori whether the
2399 instantiation is for a member template, or just a member
2400 function of a template class. Even if a member template is
2401 being instantiated, the member template arguments may be
2402 elided if they can be deduced from the rest of the
2404 tmpl = determine_specialization (declarator, decl,
2406 member_specialization,
2410 if (!tmpl || tmpl == error_mark_node)
2411 /* We couldn't figure out what this declaration was
2413 return error_mark_node;
2416 tree gen_tmpl = most_general_template (tmpl);
2418 if (explicit_instantiation)
2420 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2421 is done by do_decl_instantiation later. */
2423 int arg_depth = TMPL_ARGS_DEPTH (targs);
2424 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2426 if (arg_depth > parm_depth)
2428 /* If TMPL is not the most general template (for
2429 example, if TMPL is a friend template that is
2430 injected into namespace scope), then there will
2431 be too many levels of TARGS. Remove some of them
2436 new_targs = make_tree_vec (parm_depth);
2437 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2438 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2439 = TREE_VEC_ELT (targs, i);
2443 return instantiate_template (tmpl, targs, tf_error);
2446 /* If we thought that the DECL was a member function, but it
2447 turns out to be specializing a static member function,
2448 make DECL a static member function as well. */
2449 if (DECL_STATIC_FUNCTION_P (tmpl)
2450 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2451 revert_static_member_fn (decl);
2453 /* If this is a specialization of a member template of a
2454 template class, we want to return the TEMPLATE_DECL, not
2455 the specialization of it. */
2456 if (tsk == tsk_template)
2458 tree result = DECL_TEMPLATE_RESULT (tmpl);
2459 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2460 DECL_INITIAL (result) = NULL_TREE;
2464 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2465 DECL_SOURCE_LOCATION (result)
2466 = DECL_SOURCE_LOCATION (decl);
2467 /* We want to use the argument list specified in the
2468 definition, not in the original declaration. */
2469 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2470 for (parm = DECL_ARGUMENTS (result); parm;
2471 parm = TREE_CHAIN (parm))
2472 DECL_CONTEXT (parm) = result;
2474 return register_specialization (tmpl, gen_tmpl, targs,
2478 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2479 DECL_TEMPLATE_INFO (decl) = tree_cons (tmpl, targs, NULL_TREE);
2481 /* Inherit default function arguments from the template
2482 DECL is specializing. */
2483 copy_default_args_to_explicit_spec (decl);
2485 /* This specialization has the same protection as the
2486 template it specializes. */
2487 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2488 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2490 /* 7.1.1-1 [dcl.stc]
2492 A storage-class-specifier shall not be specified in an
2493 explicit specialization...
2495 The parser rejects these, so unless action is taken here,
2496 explicit function specializations will always appear with
2499 The action recommended by the C++ CWG in response to C++
2500 defect report 605 is to make the storage class and linkage
2501 of the explicit specialization match the templated function:
2503 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2505 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2507 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2508 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2510 /* This specialization has the same linkage and visibility as
2511 the function template it specializes. */
2512 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2513 if (! TREE_PUBLIC (decl))
2515 DECL_INTERFACE_KNOWN (decl) = 1;
2516 DECL_NOT_REALLY_EXTERN (decl) = 1;
2518 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2519 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2521 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2522 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2526 /* If DECL is a friend declaration, declared using an
2527 unqualified name, the namespace associated with DECL may
2528 have been set incorrectly. For example, in:
2530 template <typename T> void f(T);
2532 struct S { friend void f<int>(int); }
2535 we will have set the DECL_CONTEXT for the friend
2536 declaration to N, rather than to the global namespace. */
2537 if (DECL_NAMESPACE_SCOPE_P (decl))
2538 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2540 if (is_friend && !have_def)
2541 /* This is not really a declaration of a specialization.
2542 It's just the name of an instantiation. But, it's not
2543 a request for an instantiation, either. */
2544 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2545 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2546 /* This is indeed a specialization. In case of constructors
2547 and destructors, we need in-charge and not-in-charge
2548 versions in V3 ABI. */
2549 clone_function_decl (decl, /*update_method_vec_p=*/0);
2551 /* Register this specialization so that we can find it
2553 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2560 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2561 parameters. These are represented in the same format used for
2562 DECL_TEMPLATE_PARMS. */
2565 comp_template_parms (const_tree parms1, const_tree parms2)
2570 if (parms1 == parms2)
2573 for (p1 = parms1, p2 = parms2;
2574 p1 != NULL_TREE && p2 != NULL_TREE;
2575 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2577 tree t1 = TREE_VALUE (p1);
2578 tree t2 = TREE_VALUE (p2);
2581 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2582 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2584 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2587 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2589 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2590 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2592 /* If either of the template parameters are invalid, assume
2593 they match for the sake of error recovery. */
2594 if (parm1 == error_mark_node || parm2 == error_mark_node)
2597 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2600 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2601 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2602 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2604 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2609 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2610 /* One set of parameters has more parameters lists than the
2617 /* Determine whether PARM is a parameter pack. */
2619 template_parameter_pack_p (const_tree parm)
2621 /* Determine if we have a non-type template parameter pack. */
2622 if (TREE_CODE (parm) == PARM_DECL)
2623 return (DECL_TEMPLATE_PARM_P (parm)
2624 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2626 /* If this is a list of template parameters, we could get a
2627 TYPE_DECL or a TEMPLATE_DECL. */
2628 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2629 parm = TREE_TYPE (parm);
2631 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2632 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2633 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2636 /* Determine whether ARGS describes a variadic template args list,
2637 i.e., one that is terminated by a template argument pack. */
2639 template_args_variadic_p (tree args)
2644 if (args == NULL_TREE)
2647 args = INNERMOST_TEMPLATE_ARGS (args);
2648 nargs = TREE_VEC_LENGTH (args);
2653 last_parm = TREE_VEC_ELT (args, nargs - 1);
2655 return ARGUMENT_PACK_P (last_parm);
2658 /* Generate a new name for the parameter pack name NAME (an
2659 IDENTIFIER_NODE) that incorporates its */
2661 make_ith_pack_parameter_name (tree name, int i)
2663 /* Munge the name to include the parameter index. */
2664 #define NUMBUF_LEN 128
2665 char numbuf[NUMBUF_LEN];
2669 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2670 newname_len = IDENTIFIER_LENGTH (name)
2671 + strnlen (numbuf, NUMBUF_LEN) + 2;
2672 newname = (char*)alloca (newname_len);
2673 snprintf (newname, newname_len,
2674 "%s#%i", IDENTIFIER_POINTER (name), i);
2675 return get_identifier (newname);
2678 /* Return true if T is a primary function
2679 or class template instantiation. */
2682 primary_template_instantiation_p (const_tree t)
2687 if (TREE_CODE (t) == FUNCTION_DECL)
2688 return DECL_LANG_SPECIFIC (t)
2689 && DECL_TEMPLATE_INSTANTIATION (t)
2690 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2691 else if (CLASS_TYPE_P (t))
2692 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2693 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2697 /* Return true if PARM is a template template parameter. */
2700 template_template_parameter_p (const_tree parm)
2702 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2705 /* Return the template parameters of T if T is a
2706 primary template instantiation, NULL otherwise. */
2709 get_primary_template_innermost_parameters (const_tree t)
2711 tree parms = NULL, template_info = NULL;
2713 if ((template_info = get_template_info (t))
2714 && primary_template_instantiation_p (t))
2715 parms = INNERMOST_TEMPLATE_PARMS
2716 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2721 /* Returns the template arguments of T if T is a template instantiation,
2725 get_template_innermost_arguments (const_tree t)
2727 tree args = NULL, template_info = NULL;
2729 if ((template_info = get_template_info (t))
2730 && TI_ARGS (template_info))
2731 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2736 /* Return the arguments pack of T if T is a template, NULL otherwise. */
2739 get_template_argument_pack_elems (const_tree t)
2741 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2742 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2745 return ARGUMENT_PACK_ARGS (t);
2748 /* Structure used to track the progress of find_parameter_packs_r. */
2749 struct find_parameter_pack_data
2751 /* TREE_LIST that will contain all of the parameter packs found by
2753 tree* parameter_packs;
2755 /* Set of AST nodes that have been visited by the traversal. */
2756 struct pointer_set_t *visited;
2759 /* Identifies all of the argument packs that occur in a template
2760 argument and appends them to the TREE_LIST inside DATA, which is a
2761 find_parameter_pack_data structure. This is a subroutine of
2762 make_pack_expansion and uses_parameter_packs. */
2764 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2767 struct find_parameter_pack_data* ppd =
2768 (struct find_parameter_pack_data*)data;
2769 bool parameter_pack_p = false;
2771 /* Identify whether this is a parameter pack or not. */
2772 switch (TREE_CODE (t))
2774 case TEMPLATE_PARM_INDEX:
2775 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2776 parameter_pack_p = true;
2779 case TEMPLATE_TYPE_PARM:
2780 case TEMPLATE_TEMPLATE_PARM:
2781 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2782 parameter_pack_p = true;
2786 if (FUNCTION_PARAMETER_PACK_P (t))
2788 /* We don't want to walk into the type of a PARM_DECL,
2789 because we don't want to see the type parameter pack. */
2791 parameter_pack_p = true;
2796 /* Not a parameter pack. */
2800 if (parameter_pack_p)
2802 /* Add this parameter pack to the list. */
2803 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2807 cp_walk_tree (&TYPE_CONTEXT (t),
2808 &find_parameter_packs_r, ppd, ppd->visited);
2810 /* This switch statement will return immediately if we don't find a
2812 switch (TREE_CODE (t))
2814 case TEMPLATE_PARM_INDEX:
2817 case BOUND_TEMPLATE_TEMPLATE_PARM:
2818 /* Check the template itself. */
2819 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2820 &find_parameter_packs_r, ppd, ppd->visited);
2821 /* Check the template arguments. */
2822 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2827 case TEMPLATE_TYPE_PARM:
2828 case TEMPLATE_TEMPLATE_PARM:
2835 if (TYPE_PTRMEMFUNC_P (t))
2841 if (TYPE_TEMPLATE_INFO (t))
2842 cp_walk_tree (&TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
2843 &find_parameter_packs_r, ppd, ppd->visited);
2849 cp_walk_tree (&TREE_TYPE (t),
2850 &find_parameter_packs_r, ppd, ppd->visited);
2854 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
2859 case TYPE_PACK_EXPANSION:
2860 case EXPR_PACK_EXPANSION:
2865 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
2870 case IDENTIFIER_NODE:
2871 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
2883 /* Determines if the expression or type T uses any parameter packs. */
2885 uses_parameter_packs (tree t)
2887 tree parameter_packs = NULL_TREE;
2888 struct find_parameter_pack_data ppd;
2889 ppd.parameter_packs = ¶meter_packs;
2890 ppd.visited = pointer_set_create ();
2891 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2892 pointer_set_destroy (ppd.visited);
2893 return parameter_packs != NULL_TREE;
2896 /* Turn ARG, which may be an expression, type, or a TREE_LIST
2897 representation a base-class initializer into a parameter pack
2898 expansion. If all goes well, the resulting node will be an
2899 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
2902 make_pack_expansion (tree arg)
2905 tree parameter_packs = NULL_TREE;
2906 bool for_types = false;
2907 struct find_parameter_pack_data ppd;
2909 if (!arg || arg == error_mark_node)
2912 if (TREE_CODE (arg) == TREE_LIST)
2914 /* The only time we will see a TREE_LIST here is for a base
2915 class initializer. In this case, the TREE_PURPOSE will be a
2916 _TYPE node (representing the base class expansion we're
2917 initializing) and the TREE_VALUE will be a TREE_LIST
2918 containing the initialization arguments.
2920 The resulting expansion looks somewhat different from most
2921 expansions. Rather than returning just one _EXPANSION, we
2922 return a TREE_LIST whose TREE_PURPOSE is a
2923 TYPE_PACK_EXPANSION containing the bases that will be
2924 initialized. The TREE_VALUE will be identical to the
2925 original TREE_VALUE, which is a list of arguments that will
2926 be passed to each base. We do not introduce any new pack
2927 expansion nodes into the TREE_VALUE (although it is possible
2928 that some already exist), because the TREE_PURPOSE and
2929 TREE_VALUE all need to be expanded together with the same
2930 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
2931 resulting TREE_PURPOSE will mention the parameter packs in
2932 both the bases and the arguments to the bases. */
2935 tree parameter_packs = NULL_TREE;
2937 /* Determine which parameter packs will be used by the base
2939 ppd.visited = pointer_set_create ();
2940 ppd.parameter_packs = ¶meter_packs;
2941 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
2944 if (parameter_packs == NULL_TREE)
2946 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
2947 pointer_set_destroy (ppd.visited);
2948 return error_mark_node;
2951 if (TREE_VALUE (arg) != void_type_node)
2953 /* Collect the sets of parameter packs used in each of the
2954 initialization arguments. */
2955 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
2957 /* Determine which parameter packs will be expanded in this
2959 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
2964 pointer_set_destroy (ppd.visited);
2966 /* Create the pack expansion type for the base type. */
2967 purpose = make_node (TYPE_PACK_EXPANSION);
2968 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
2969 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
2971 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
2972 they will rarely be compared to anything. */
2973 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
2975 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
2978 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
2981 /* Build the PACK_EXPANSION_* node. */
2982 result = make_node (for_types ? TYPE_PACK_EXPANSION : EXPR_PACK_EXPANSION);
2983 SET_PACK_EXPANSION_PATTERN (result, arg);
2984 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
2986 /* Propagate type and const-expression information. */
2987 TREE_TYPE (result) = TREE_TYPE (arg);
2988 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
2991 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
2992 they will rarely be compared to anything. */
2993 SET_TYPE_STRUCTURAL_EQUALITY (result);
2995 /* Determine which parameter packs will be expanded. */
2996 ppd.parameter_packs = ¶meter_packs;
2997 ppd.visited = pointer_set_create ();
2998 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
2999 pointer_set_destroy (ppd.visited);
3001 /* Make sure we found some parameter packs. */
3002 if (parameter_packs == NULL_TREE)
3005 error ("expansion pattern %<%T%> contains no argument packs", arg);
3007 error ("expansion pattern %<%E%> contains no argument packs", arg);
3008 return error_mark_node;
3010 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3015 /* Checks T for any "bare" parameter packs, which have not yet been
3016 expanded, and issues an error if any are found. This operation can
3017 only be done on full expressions or types (e.g., an expression
3018 statement, "if" condition, etc.), because we could have expressions like:
3020 foo(f(g(h(args)))...)
3022 where "args" is a parameter pack. check_for_bare_parameter_packs
3023 should not be called for the subexpressions args, h(args),
3024 g(h(args)), or f(g(h(args))), because we would produce erroneous
3027 Returns TRUE and emits an error if there were bare parameter packs,
3028 returns FALSE otherwise. */
3030 check_for_bare_parameter_packs (tree t)
3032 tree parameter_packs = NULL_TREE;
3033 struct find_parameter_pack_data ppd;
3035 if (!processing_template_decl || !t || t == error_mark_node)
3038 if (TREE_CODE (t) == TYPE_DECL)
3041 ppd.parameter_packs = ¶meter_packs;
3042 ppd.visited = pointer_set_create ();
3043 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3044 pointer_set_destroy (ppd.visited);
3046 if (parameter_packs)
3048 error ("parameter packs not expanded with %<...%>:");
3049 while (parameter_packs)
3051 tree pack = TREE_VALUE (parameter_packs);
3052 tree name = NULL_TREE;
3054 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3055 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3056 name = TYPE_NAME (pack);
3057 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3058 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3060 name = DECL_NAME (pack);
3063 inform (input_location, " %qD", name);
3065 inform (input_location, " <anonymous>");
3067 parameter_packs = TREE_CHAIN (parameter_packs);
3076 /* Expand any parameter packs that occur in the template arguments in
3079 expand_template_argument_pack (tree args)
3081 tree result_args = NULL_TREE;
3082 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3083 int num_result_args = -1;
3085 /* First, determine if we need to expand anything, and the number of
3086 slots we'll need. */
3087 for (in_arg = 0; in_arg < nargs; ++in_arg)
3089 tree arg = TREE_VEC_ELT (args, in_arg);
3090 if (ARGUMENT_PACK_P (arg))
3092 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3093 if (num_result_args < 0)
3094 num_result_args = in_arg + num_packed;
3096 num_result_args += num_packed;
3100 if (num_result_args >= 0)
3105 /* If no expansion is necessary, we're done. */
3106 if (num_result_args < 0)
3109 /* Expand arguments. */
3110 result_args = make_tree_vec (num_result_args);
3111 for (in_arg = 0; in_arg < nargs; ++in_arg)
3113 tree arg = TREE_VEC_ELT (args, in_arg);
3114 if (ARGUMENT_PACK_P (arg))
3116 tree packed = ARGUMENT_PACK_ARGS (arg);
3117 int i, num_packed = TREE_VEC_LENGTH (packed);
3118 for (i = 0; i < num_packed; ++i, ++out_arg)
3119 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3123 TREE_VEC_ELT (result_args, out_arg) = arg;
3131 /* Checks if DECL shadows a template parameter.
3133 [temp.local]: A template-parameter shall not be redeclared within its
3134 scope (including nested scopes).
3136 Emits an error and returns TRUE if the DECL shadows a parameter,
3137 returns FALSE otherwise. */
3140 check_template_shadow (tree decl)
3144 /* If we're not in a template, we can't possibly shadow a template
3146 if (!current_template_parms)
3149 /* Figure out what we're shadowing. */
3150 if (TREE_CODE (decl) == OVERLOAD)
3151 decl = OVL_CURRENT (decl);
3152 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3154 /* If there's no previous binding for this name, we're not shadowing
3155 anything, let alone a template parameter. */
3159 /* If we're not shadowing a template parameter, we're done. Note
3160 that OLDDECL might be an OVERLOAD (or perhaps even an
3161 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3163 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3166 /* We check for decl != olddecl to avoid bogus errors for using a
3167 name inside a class. We check TPFI to avoid duplicate errors for
3168 inline member templates. */
3170 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3173 error ("declaration of %q+#D", decl);
3174 error (" shadows template parm %q+#D", olddecl);
3178 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3179 ORIG_LEVEL, DECL, and TYPE. */
3182 build_template_parm_index (int index,
3188 tree t = make_node (TEMPLATE_PARM_INDEX);
3189 TEMPLATE_PARM_IDX (t) = index;
3190 TEMPLATE_PARM_LEVEL (t) = level;
3191 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3192 TEMPLATE_PARM_DECL (t) = decl;
3193 TREE_TYPE (t) = type;
3194 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3195 TREE_READONLY (t) = TREE_READONLY (decl);
3200 /* Find the canonical type parameter for the given template type
3201 parameter. Returns the canonical type parameter, which may be TYPE
3202 if no such parameter existed. */
3204 canonical_type_parameter (tree type)
3207 int idx = TEMPLATE_TYPE_IDX (type);
3208 if (!canonical_template_parms)
3209 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3211 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3212 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3214 list = VEC_index (tree, canonical_template_parms, idx);
3215 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3216 list = TREE_CHAIN (list);
3219 return TREE_VALUE (list);
3222 VEC_replace(tree, canonical_template_parms, idx,
3223 tree_cons (NULL_TREE, type,
3224 VEC_index (tree, canonical_template_parms, idx)));
3229 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3230 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3231 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3232 new one is created. */
3235 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3236 tsubst_flags_t complain)
3238 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3239 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3240 != TEMPLATE_PARM_LEVEL (index) - levels))
3242 tree orig_decl = TEMPLATE_PARM_DECL (index);
3245 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3246 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3247 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3248 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3249 DECL_ARTIFICIAL (decl) = 1;
3250 SET_DECL_TEMPLATE_PARM_P (decl);
3252 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3253 TEMPLATE_PARM_LEVEL (index) - levels,
3254 TEMPLATE_PARM_ORIG_LEVEL (index),
3256 TEMPLATE_PARM_DESCENDANTS (index) = t;
3257 TEMPLATE_PARM_PARAMETER_PACK (t)
3258 = TEMPLATE_PARM_PARAMETER_PACK (index);
3260 /* Template template parameters need this. */
3261 if (TREE_CODE (decl) == TEMPLATE_DECL)
3262 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3263 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3267 return TEMPLATE_PARM_DESCENDANTS (index);
3270 /* Process information from new template parameter PARM and append it to the
3271 LIST being built. This new parameter is a non-type parameter iff
3272 IS_NON_TYPE is true. This new parameter is a parameter
3273 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3277 process_template_parm (tree list, location_t parm_loc, tree parm, bool is_non_type,
3278 bool is_parameter_pack)
3285 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3286 defval = TREE_PURPOSE (parm);
3290 tree p = tree_last (list);
3292 if (p && TREE_VALUE (p) != error_mark_node)
3295 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3296 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3298 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3308 parm = TREE_VALUE (parm);
3310 SET_DECL_TEMPLATE_PARM_P (parm);
3312 if (TREE_TYPE (parm) == error_mark_node)
3314 err_parm_list = build_tree_list (defval, parm);
3315 TREE_VALUE (err_parm_list) = error_mark_node;
3316 return chainon (list, err_parm_list);
3322 The top-level cv-qualifiers on the template-parameter are
3323 ignored when determining its type. */
3324 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3325 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3327 err_parm_list = build_tree_list (defval, parm);
3328 TREE_VALUE (err_parm_list) = error_mark_node;
3329 return chainon (list, err_parm_list);
3332 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3334 /* This template parameter is not a parameter pack, but it
3335 should be. Complain about "bare" parameter packs. */
3336 check_for_bare_parameter_packs (TREE_TYPE (parm));
3338 /* Recover by calling this a parameter pack. */
3339 is_parameter_pack = true;
3343 /* A template parameter is not modifiable. */
3344 TREE_CONSTANT (parm) = 1;
3345 TREE_READONLY (parm) = 1;
3346 decl = build_decl (parm_loc,
3347 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3348 TREE_CONSTANT (decl) = 1;
3349 TREE_READONLY (decl) = 1;
3350 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3351 = build_template_parm_index (idx, processing_template_decl,
3352 processing_template_decl,
3353 decl, TREE_TYPE (parm));
3355 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3356 = is_parameter_pack;
3361 parm = TREE_VALUE (TREE_VALUE (parm));
3363 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3365 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3366 /* This is for distinguishing between real templates and template
3367 template parameters */
3368 TREE_TYPE (parm) = t;
3369 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3374 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3375 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3376 decl = build_decl (parm_loc,
3377 TYPE_DECL, parm, t);
3380 TYPE_NAME (t) = decl;
3381 TYPE_STUB_DECL (t) = decl;
3383 TEMPLATE_TYPE_PARM_INDEX (t)
3384 = build_template_parm_index (idx, processing_template_decl,
3385 processing_template_decl,
3386 decl, TREE_TYPE (parm));
3387 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3388 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3390 DECL_ARTIFICIAL (decl) = 1;
3391 SET_DECL_TEMPLATE_PARM_P (decl);
3393 parm = build_tree_list (defval, parm);
3394 return chainon (list, parm);
3397 /* The end of a template parameter list has been reached. Process the
3398 tree list into a parameter vector, converting each parameter into a more
3399 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3403 end_template_parm_list (tree parms)
3407 tree saved_parmlist = make_tree_vec (list_length (parms));
3409 current_template_parms
3410 = tree_cons (size_int (processing_template_decl),
3411 saved_parmlist, current_template_parms);
3413 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3415 next = TREE_CHAIN (parm);
3416 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3417 TREE_CHAIN (parm) = NULL_TREE;
3420 --processing_template_parmlist;
3422 return saved_parmlist;
3425 /* end_template_decl is called after a template declaration is seen. */
3428 end_template_decl (void)
3430 reset_specialization ();
3432 if (! processing_template_decl)
3435 /* This matches the pushlevel in begin_template_parm_list. */
3438 --processing_template_decl;
3439 current_template_parms = TREE_CHAIN (current_template_parms);
3442 /* Within the declaration of a template, return all levels of template
3443 parameters that apply. The template parameters are represented as
3444 a TREE_VEC, in the form documented in cp-tree.h for template
3448 current_template_args (void)
3451 tree args = NULL_TREE;
3452 int length = TMPL_PARMS_DEPTH (current_template_parms);
3455 /* If there is only one level of template parameters, we do not
3456 create a TREE_VEC of TREE_VECs. Instead, we return a single
3457 TREE_VEC containing the arguments. */
3459 args = make_tree_vec (length);
3461 for (header = current_template_parms; header; header = TREE_CHAIN (header))
3463 tree a = copy_node (TREE_VALUE (header));
3466 TREE_TYPE (a) = NULL_TREE;
3467 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3469 tree t = TREE_VEC_ELT (a, i);
3471 /* T will be a list if we are called from within a
3472 begin/end_template_parm_list pair, but a vector directly
3473 if within a begin/end_member_template_processing pair. */
3474 if (TREE_CODE (t) == TREE_LIST)
3478 if (!error_operand_p (t))
3480 if (TREE_CODE (t) == TYPE_DECL
3481 || TREE_CODE (t) == TEMPLATE_DECL)
3485 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3487 /* Turn this argument into a TYPE_ARGUMENT_PACK
3488 with a single element, which expands T. */
3489 tree vec = make_tree_vec (1);
3490 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3492 t = make_node (TYPE_ARGUMENT_PACK);
3493 SET_ARGUMENT_PACK_ARGS (t, vec);
3498 t = DECL_INITIAL (t);
3500 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3502 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3503 with a single element, which expands T. */
3504 tree vec = make_tree_vec (1);
3505 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3506 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3508 t = make_node (NONTYPE_ARGUMENT_PACK);
3509 SET_ARGUMENT_PACK_ARGS (t, vec);
3510 TREE_TYPE (t) = type;
3513 TREE_VEC_ELT (a, i) = t;
3519 TREE_VEC_ELT (args, --l) = a;
3527 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3528 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3529 a member template. Used by push_template_decl below. */
3532 build_template_decl (tree decl, tree parms, bool member_template_p)
3534 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3535 DECL_TEMPLATE_PARMS (tmpl) = parms;
3536 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3537 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3542 struct template_parm_data
3544 /* The level of the template parameters we are currently
3548 /* The index of the specialization argument we are currently
3552 /* An array whose size is the number of template parameters. The
3553 elements are nonzero if the parameter has been used in any one
3554 of the arguments processed so far. */
3557 /* An array whose size is the number of template arguments. The
3558 elements are nonzero if the argument makes use of template
3559 parameters of this level. */
3560 int* arg_uses_template_parms;
3563 /* Subroutine of push_template_decl used to see if each template
3564 parameter in a partial specialization is used in the explicit
3565 argument list. If T is of the LEVEL given in DATA (which is
3566 treated as a template_parm_data*), then DATA->PARMS is marked
3570 mark_template_parm (tree t, void* data)
3574 struct template_parm_data* tpd = (struct template_parm_data*) data;
3576 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3578 level = TEMPLATE_PARM_LEVEL (t);
3579 idx = TEMPLATE_PARM_IDX (t);
3583 level = TEMPLATE_TYPE_LEVEL (t);
3584 idx = TEMPLATE_TYPE_IDX (t);
3587 if (level == tpd->level)
3589 tpd->parms[idx] = 1;
3590 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
3593 /* Return zero so that for_each_template_parm will continue the
3594 traversal of the tree; we want to mark *every* template parm. */
3598 /* Process the partial specialization DECL. */
3601 process_partial_specialization (tree decl)
3603 tree type = TREE_TYPE (decl);
3604 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
3605 tree specargs = CLASSTYPE_TI_ARGS (type);
3606 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
3607 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
3609 int nargs = TREE_VEC_LENGTH (inner_args);
3612 int did_error_intro = 0;
3613 struct template_parm_data tpd;
3614 struct template_parm_data tpd2;
3616 gcc_assert (current_template_parms);
3618 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3619 ntparms = TREE_VEC_LENGTH (inner_parms);
3621 /* We check that each of the template parameters given in the
3622 partial specialization is used in the argument list to the
3623 specialization. For example:
3625 template <class T> struct S;
3626 template <class T> struct S<T*>;
3628 The second declaration is OK because `T*' uses the template
3629 parameter T, whereas
3631 template <class T> struct S<int>;
3633 is no good. Even trickier is:
3644 The S2<T> declaration is actually invalid; it is a
3645 full-specialization. Of course,
3648 struct S2<T (*)(U)>;
3650 or some such would have been OK. */
3651 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
3652 tpd.parms = (int *) alloca (sizeof (int) * ntparms);
3653 memset (tpd.parms, 0, sizeof (int) * ntparms);
3655 tpd.arg_uses_template_parms = (int *) alloca (sizeof (int) * nargs);
3656 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
3657 for (i = 0; i < nargs; ++i)
3659 tpd.current_arg = i;
3660 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
3661 &mark_template_parm,
3664 /*include_nondeduced_p=*/false);
3666 for (i = 0; i < ntparms; ++i)
3667 if (tpd.parms[i] == 0)
3669 /* One of the template parms was not used in the
3671 if (!did_error_intro)
3673 error ("template parameters not used in partial specialization:");
3674 did_error_intro = 1;
3677 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
3680 /* [temp.class.spec]
3682 The argument list of the specialization shall not be identical to
3683 the implicit argument list of the primary template. */
3684 if (comp_template_args
3686 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
3688 error ("partial specialization %qT does not specialize any template arguments", type);
3690 /* [temp.class.spec]
3692 A partially specialized non-type argument expression shall not
3693 involve template parameters of the partial specialization except
3694 when the argument expression is a simple identifier.
3696 The type of a template parameter corresponding to a specialized
3697 non-type argument shall not be dependent on a parameter of the
3700 Also, we verify that pack expansions only occur at the
3701 end of the argument list. */
3702 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
3704 for (i = 0; i < nargs; ++i)
3706 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
3707 tree arg = TREE_VEC_ELT (inner_args, i);
3708 tree packed_args = NULL_TREE;
3711 if (ARGUMENT_PACK_P (arg))
3713 /* Extract the arguments from the argument pack. We'll be
3714 iterating over these in the following loop. */
3715 packed_args = ARGUMENT_PACK_ARGS (arg);
3716 len = TREE_VEC_LENGTH (packed_args);
3719 for (j = 0; j < len; j++)
3722 /* Get the Jth argument in the parameter pack. */
3723 arg = TREE_VEC_ELT (packed_args, j);
3725 if (PACK_EXPANSION_P (arg))
3727 /* Pack expansions must come at the end of the
3729 if ((packed_args && j < len - 1)
3730 || (!packed_args && i < nargs - 1))
3732 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3733 error ("parameter pack argument %qE must be at the end of the template argument list", arg);
3735 error ("parameter pack argument %qT must be at the end of the template argument list", arg);
3738 TREE_VEC_ELT (packed_args, j) = error_mark_node;
3742 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3743 /* We only care about the pattern. */
3744 arg = PACK_EXPANSION_PATTERN (arg);
3746 if (/* These first two lines are the `non-type' bit. */
3748 && TREE_CODE (arg) != TEMPLATE_DECL
3749 /* This next line is the `argument expression is not just a
3750 simple identifier' condition and also the `specialized
3751 non-type argument' bit. */
3752 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
3754 if ((!packed_args && tpd.arg_uses_template_parms[i])
3755 || (packed_args && uses_template_parms (arg)))
3756 error ("template argument %qE involves template parameter(s)",
3760 /* Look at the corresponding template parameter,
3761 marking which template parameters its type depends
3763 tree type = TREE_TYPE (parm);
3767 /* We haven't yet initialized TPD2. Do so now. */
3768 tpd2.arg_uses_template_parms
3769 = (int *) alloca (sizeof (int) * nargs);
3770 /* The number of parameters here is the number in the
3771 main template, which, as checked in the assertion
3773 tpd2.parms = (int *) alloca (sizeof (int) * nargs);
3775 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
3778 /* Mark the template parameters. But this time, we're
3779 looking for the template parameters of the main
3780 template, not in the specialization. */
3781 tpd2.current_arg = i;
3782 tpd2.arg_uses_template_parms[i] = 0;
3783 memset (tpd2.parms, 0, sizeof (int) * nargs);
3784 for_each_template_parm (type,
3785 &mark_template_parm,
3788 /*include_nondeduced_p=*/false);
3790 if (tpd2.arg_uses_template_parms [i])
3792 /* The type depended on some template parameters.
3793 If they are fully specialized in the
3794 specialization, that's OK. */
3796 for (j = 0; j < nargs; ++j)
3797 if (tpd2.parms[j] != 0
3798 && tpd.arg_uses_template_parms [j])
3800 error ("type %qT of template argument %qE depends "
3801 "on template parameter(s)",
3812 /* We should only get here once. */
3813 gcc_assert (!COMPLETE_TYPE_P (type));
3815 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
3816 = tree_cons (specargs, inner_parms,
3817 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
3818 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
3822 /* Check that a template declaration's use of default arguments and
3823 parameter packs is not invalid. Here, PARMS are the template
3824 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
3825 a primary template. IS_PARTIAL is nonzero if DECL is a partial
3829 IS_FRIEND_DECL is nonzero if DECL is a friend function template
3830 declaration (but not a definition); 1 indicates a declaration, 2
3831 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
3832 emitted for extraneous default arguments.
3834 Returns TRUE if there were no errors found, FALSE otherwise. */
3837 check_default_tmpl_args (tree decl, tree parms, int is_primary,
3838 int is_partial, int is_friend_decl)
3841 int last_level_to_check;
3843 bool no_errors = true;
3847 A default template-argument shall not be specified in a
3848 function template declaration or a function template definition, nor
3849 in the template-parameter-list of the definition of a member of a
3852 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
3853 /* You can't have a function template declaration in a local
3854 scope, nor you can you define a member of a class template in a
3858 if (current_class_type
3859 && !TYPE_BEING_DEFINED (current_class_type)
3860 && DECL_LANG_SPECIFIC (decl)
3861 && DECL_DECLARES_FUNCTION_P (decl)
3862 /* If this is either a friend defined in the scope of the class
3863 or a member function. */
3864 && (DECL_FUNCTION_MEMBER_P (decl)
3865 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
3866 : DECL_FRIEND_CONTEXT (decl)
3867 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
3869 /* And, if it was a member function, it really was defined in
3870 the scope of the class. */
3871 && (!DECL_FUNCTION_MEMBER_P (decl)
3872 || DECL_INITIALIZED_IN_CLASS_P (decl)))
3873 /* We already checked these parameters when the template was
3874 declared, so there's no need to do it again now. This function
3875 was defined in class scope, but we're processing it's body now
3876 that the class is complete. */
3879 /* Core issue 226 (C++0x only): the following only applies to class
3881 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
3885 If a template-parameter has a default template-argument, all
3886 subsequent template-parameters shall have a default
3887 template-argument supplied. */
3888 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
3890 tree inner_parms = TREE_VALUE (parm_level);
3891 int ntparms = TREE_VEC_LENGTH (inner_parms);
3892 int seen_def_arg_p = 0;
3895 for (i = 0; i < ntparms; ++i)
3897 tree parm = TREE_VEC_ELT (inner_parms, i);
3899 if (parm == error_mark_node)
3902 if (TREE_PURPOSE (parm))
3904 else if (seen_def_arg_p
3905 && !template_parameter_pack_p (TREE_VALUE (parm)))
3907 error ("no default argument for %qD", TREE_VALUE (parm));
3908 /* For better subsequent error-recovery, we indicate that
3909 there should have been a default argument. */
3910 TREE_PURPOSE (parm) = error_mark_node;
3916 /* Don't complain about an enclosing partial
3918 && parm_level == parms
3919 && TREE_CODE (decl) == TYPE_DECL
3921 && template_parameter_pack_p (TREE_VALUE (parm)))
3923 /* A primary class template can only have one
3924 parameter pack, at the end of the template
3927 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
3928 error ("parameter pack %qE must be at the end of the"
3929 " template parameter list", TREE_VALUE (parm));
3931 error ("parameter pack %qT must be at the end of the"
3932 " template parameter list",
3933 TREE_TYPE (TREE_VALUE (parm)));
3935 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
3943 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
3947 /* For an ordinary class template, default template arguments are
3948 allowed at the innermost level, e.g.:
3949 template <class T = int>
3951 but, in a partial specialization, they're not allowed even
3952 there, as we have in [temp.class.spec]:
3954 The template parameter list of a specialization shall not
3955 contain default template argument values.
3957 So, for a partial specialization, or for a function template
3958 (in C++98/C++03), we look at all of them. */
3961 /* But, for a primary class template that is not a partial
3962 specialization we look at all template parameters except the
3964 parms = TREE_CHAIN (parms);
3966 /* Figure out what error message to issue. */
3967 if (is_friend_decl == 2)
3968 msg = "default template arguments may not be used in function template friend re-declaration";
3969 else if (is_friend_decl)
3970 msg = "default template arguments may not be used in function template friend declarations";
3971 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
3972 msg = "default template arguments may not be used in function templates";
3973 else if (is_partial)
3974 msg = "default template arguments may not be used in partial specializations";
3976 msg = "default argument for template parameter for class enclosing %qD";
3978 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
3979 /* If we're inside a class definition, there's no need to
3980 examine the parameters to the class itself. On the one
3981 hand, they will be checked when the class is defined, and,
3982 on the other, default arguments are valid in things like:
3983 template <class T = double>
3984 struct S { template <class U> void f(U); };
3985 Here the default argument for `S' has no bearing on the
3986 declaration of `f'. */
3987 last_level_to_check = template_class_depth (current_class_type) + 1;
3989 /* Check everything. */
3990 last_level_to_check = 0;
3992 for (parm_level = parms;
3993 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
3994 parm_level = TREE_CHAIN (parm_level))
3996 tree inner_parms = TREE_VALUE (parm_level);
4000 ntparms = TREE_VEC_LENGTH (inner_parms);
4001 for (i = 0; i < ntparms; ++i)
4003 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4006 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4011 if (is_friend_decl == 2)
4018 /* Clear out the default argument so that we are not
4020 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4024 /* At this point, if we're still interested in issuing messages,
4025 they must apply to classes surrounding the object declared. */
4027 msg = "default argument for template parameter for class enclosing %qD";
4033 /* Worker for push_template_decl_real, called via
4034 for_each_template_parm. DATA is really an int, indicating the
4035 level of the parameters we are interested in. If T is a template
4036 parameter of that level, return nonzero. */
4039 template_parm_this_level_p (tree t, void* data)
4041 int this_level = *(int *)data;
4044 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4045 level = TEMPLATE_PARM_LEVEL (t);
4047 level = TEMPLATE_TYPE_LEVEL (t);
4048 return level == this_level;
4051 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4052 parameters given by current_template_args, or reuses a
4053 previously existing one, if appropriate. Returns the DECL, or an
4054 equivalent one, if it is replaced via a call to duplicate_decls.
4056 If IS_FRIEND is true, DECL is a friend declaration. */
4059 push_template_decl_real (tree decl, bool is_friend)
4067 int new_template_p = 0;
4068 /* True if the template is a member template, in the sense of
4070 bool member_template_p = false;
4072 if (decl == error_mark_node || !current_template_parms)
4073 return error_mark_node;
4075 /* See if this is a partial specialization. */
4076 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4077 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4078 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4080 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4084 /* For a friend, we want the context of the friend function, not
4085 the type of which it is a friend. */
4086 ctx = DECL_CONTEXT (decl);
4087 else if (CP_DECL_CONTEXT (decl)
4088 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4089 /* In the case of a virtual function, we want the class in which
4091 ctx = CP_DECL_CONTEXT (decl);
4093 /* Otherwise, if we're currently defining some class, the DECL
4094 is assumed to be a member of the class. */
4095 ctx = current_scope ();
4097 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4100 if (!DECL_CONTEXT (decl))
4101 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4103 /* See if this is a primary template. */
4104 if (is_friend && ctx)
4105 /* A friend template that specifies a class context, i.e.
4106 template <typename T> friend void A<T>::f();
4110 primary = template_parm_scope_p ();
4114 if (DECL_CLASS_SCOPE_P (decl))
4115 member_template_p = true;
4116 if (TREE_CODE (decl) == TYPE_DECL
4117 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4119 error ("template class without a name");
4120 return error_mark_node;
4122 else if (TREE_CODE (decl) == FUNCTION_DECL)
4124 if (DECL_DESTRUCTOR_P (decl))
4128 A destructor shall not be a member template. */
4129 error ("destructor %qD declared as member template", decl);
4130 return error_mark_node;
4132 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4133 && (!TYPE_ARG_TYPES (TREE_TYPE (decl))
4134 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4135 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4136 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4137 == void_list_node)))
4139 /* [basic.stc.dynamic.allocation]
4141 An allocation function can be a function
4142 template. ... Template allocation functions shall
4143 have two or more parameters. */
4144 error ("invalid template declaration of %qD", decl);
4145 return error_mark_node;
4148 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4149 && CLASS_TYPE_P (TREE_TYPE (decl)))
4153 error ("template declaration of %q#D", decl);
4154 return error_mark_node;
4158 /* Check to see that the rules regarding the use of default
4159 arguments are not being violated. */
4160 check_default_tmpl_args (decl, current_template_parms,
4161 primary, is_partial, /*is_friend_decl=*/0);
4163 /* Ensure that there are no parameter packs in the type of this
4164 declaration that have not been expanded. */
4165 if (TREE_CODE (decl) == FUNCTION_DECL)
4167 /* Check each of the arguments individually to see if there are
4168 any bare parameter packs. */
4169 tree type = TREE_TYPE (decl);
4170 tree arg = DECL_ARGUMENTS (decl);
4171 tree argtype = TYPE_ARG_TYPES (type);
4173 while (arg && argtype)
4175 if (!FUNCTION_PARAMETER_PACK_P (arg)
4176 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4178 /* This is a PARM_DECL that contains unexpanded parameter
4179 packs. We have already complained about this in the
4180 check_for_bare_parameter_packs call, so just replace
4181 these types with ERROR_MARK_NODE. */
4182 TREE_TYPE (arg) = error_mark_node;
4183 TREE_VALUE (argtype) = error_mark_node;
4186 arg = TREE_CHAIN (arg);
4187 argtype = TREE_CHAIN (argtype);
4190 /* Check for bare parameter packs in the return type and the
4191 exception specifiers. */
4192 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4193 /* Errors were already issued, set return type to int
4194 as the frontend doesn't expect error_mark_node as
4196 TREE_TYPE (type) = integer_type_node;
4197 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4198 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4200 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4202 TREE_TYPE (decl) = error_mark_node;
4203 return error_mark_node;
4207 return process_partial_specialization (decl);
4209 args = current_template_args ();
4212 || TREE_CODE (ctx) == FUNCTION_DECL
4213 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4214 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4216 if (DECL_LANG_SPECIFIC (decl)
4217 && DECL_TEMPLATE_INFO (decl)
4218 && DECL_TI_TEMPLATE (decl))
4219 tmpl = DECL_TI_TEMPLATE (decl);
4220 /* If DECL is a TYPE_DECL for a class-template, then there won't
4221 be DECL_LANG_SPECIFIC. The information equivalent to
4222 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4223 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4224 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4225 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4227 /* Since a template declaration already existed for this
4228 class-type, we must be redeclaring it here. Make sure
4229 that the redeclaration is valid. */
4230 redeclare_class_template (TREE_TYPE (decl),
4231 current_template_parms);
4232 /* We don't need to create a new TEMPLATE_DECL; just use the
4233 one we already had. */
4234 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4238 tmpl = build_template_decl (decl, current_template_parms,
4242 if (DECL_LANG_SPECIFIC (decl)
4243 && DECL_TEMPLATE_SPECIALIZATION (decl))
4245 /* A specialization of a member template of a template
4247 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4248 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4249 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4255 tree a, t, current, parms;
4257 tree tinfo = get_template_info (decl);
4261 error ("template definition of non-template %q#D", decl);
4262 return error_mark_node;
4265 tmpl = TI_TEMPLATE (tinfo);
4267 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4268 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4269 && DECL_TEMPLATE_SPECIALIZATION (decl)
4270 && DECL_MEMBER_TEMPLATE_P (tmpl))
4274 /* The declaration is a specialization of a member
4275 template, declared outside the class. Therefore, the
4276 innermost template arguments will be NULL, so we
4277 replace them with the arguments determined by the
4278 earlier call to check_explicit_specialization. */
4279 args = DECL_TI_ARGS (decl);
4282 = build_template_decl (decl, current_template_parms,
4284 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4285 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4286 DECL_TI_TEMPLATE (decl) = new_tmpl;
4287 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4288 DECL_TEMPLATE_INFO (new_tmpl)
4289 = tree_cons (tmpl, args, NULL_TREE);
4291 register_specialization (new_tmpl,
4292 most_general_template (tmpl),
4298 /* Make sure the template headers we got make sense. */
4300 parms = DECL_TEMPLATE_PARMS (tmpl);
4301 i = TMPL_PARMS_DEPTH (parms);
4302 if (TMPL_ARGS_DEPTH (args) != i)
4304 error ("expected %d levels of template parms for %q#D, got %d",
4305 i, decl, TMPL_ARGS_DEPTH (args));
4308 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4310 a = TMPL_ARGS_LEVEL (args, i);
4311 t = INNERMOST_TEMPLATE_PARMS (parms);
4313 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4315 if (current == decl)
4316 error ("got %d template parameters for %q#D",
4317 TREE_VEC_LENGTH (a), decl);
4319 error ("got %d template parameters for %q#T",
4320 TREE_VEC_LENGTH (a), current);
4321 error (" but %d required", TREE_VEC_LENGTH (t));
4322 return error_mark_node;
4325 if (current == decl)
4328 current = (TYPE_P (current)
4329 ? TYPE_CONTEXT (current)
4330 : DECL_CONTEXT (current));
4333 /* Check that the parms are used in the appropriate qualifying scopes
4334 in the declarator. */
4335 if (!comp_template_args
4337 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4340 template arguments to %qD do not match original template %qD",
4341 decl, DECL_TEMPLATE_RESULT (tmpl));
4342 if (!uses_template_parms (TI_ARGS (tinfo)))
4343 inform (input_location, "use template<> for an explicit specialization");
4344 /* Avoid crash in import_export_decl. */
4345 DECL_INTERFACE_KNOWN (decl) = 1;
4346 return error_mark_node;
4350 DECL_TEMPLATE_RESULT (tmpl) = decl;
4351 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4353 /* Push template declarations for global functions and types. Note
4354 that we do not try to push a global template friend declared in a
4355 template class; such a thing may well depend on the template
4356 parameters of the class. */
4357 if (new_template_p && !ctx
4358 && !(is_friend && template_class_depth (current_class_type) > 0))
4360 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4361 if (tmpl == error_mark_node)
4362 return error_mark_node;
4364 /* Hide template friend classes that haven't been declared yet. */
4365 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4367 DECL_ANTICIPATED (tmpl) = 1;
4368 DECL_FRIEND_P (tmpl) = 1;
4374 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4377 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4378 if (DECL_CONV_FN_P (tmpl))
4380 int depth = TMPL_PARMS_DEPTH (parms);
4382 /* It is a conversion operator. See if the type converted to
4383 depends on innermost template operands. */
4385 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4387 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4390 /* Give template template parms a DECL_CONTEXT of the template
4391 for which they are a parameter. */
4392 parms = INNERMOST_TEMPLATE_PARMS (parms);
4393 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4395 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4396 if (TREE_CODE (parm) == TEMPLATE_DECL)
4397 DECL_CONTEXT (parm) = tmpl;
4401 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4402 back to its most general template. If TMPL is a specialization,
4403 ARGS may only have the innermost set of arguments. Add the missing
4404 argument levels if necessary. */
4405 if (DECL_TEMPLATE_INFO (tmpl))
4406 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4408 info = tree_cons (tmpl, args, NULL_TREE);
4410 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4411 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4412 else if (DECL_LANG_SPECIFIC (decl))
4413 DECL_TEMPLATE_INFO (decl) = info;
4415 return DECL_TEMPLATE_RESULT (tmpl);
4419 push_template_decl (tree decl)
4421 return push_template_decl_real (decl, false);
4424 /* Called when a class template TYPE is redeclared with the indicated
4425 template PARMS, e.g.:
4427 template <class T> struct S;
4428 template <class T> struct S {}; */
4431 redeclare_class_template (tree type, tree parms)
4437 if (!TYPE_TEMPLATE_INFO (type))
4439 error ("%qT is not a template type", type);
4443 tmpl = TYPE_TI_TEMPLATE (type);
4444 if (!PRIMARY_TEMPLATE_P (tmpl))
4445 /* The type is nested in some template class. Nothing to worry
4446 about here; there are no new template parameters for the nested
4452 error ("template specifiers not specified in declaration of %qD",
4457 parms = INNERMOST_TEMPLATE_PARMS (parms);
4458 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4460 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4462 error ("redeclared with %d template parameter(s)",
4463 TREE_VEC_LENGTH (parms));
4464 inform (input_location, "previous declaration %q+D used %d template parameter(s)",
4465 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4469 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4476 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4477 || TREE_VEC_ELT (parms, i) == error_mark_node)
4480 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4481 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4482 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4483 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4485 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4487 if (tmpl_parm != error_mark_node
4488 && (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
4489 || (TREE_CODE (tmpl_parm) != TYPE_DECL
4490 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
4491 || (TREE_CODE (tmpl_parm) != PARM_DECL
4492 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
4493 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
4494 || (TREE_CODE (tmpl_parm) == PARM_DECL
4495 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
4496 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))))))
4498 error ("template parameter %q+#D", tmpl_parm);
4499 error ("redeclared here as %q#D", parm);
4503 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
4505 /* We have in [temp.param]:
4507 A template-parameter may not be given default arguments
4508 by two different declarations in the same scope. */
4509 error_at (input_location, "redefinition of default argument for %q#D", parm);
4510 inform (DECL_SOURCE_LOCATION (tmpl_parm),
4511 "original definition appeared here");
4515 if (parm_default != NULL_TREE)
4516 /* Update the previous template parameters (which are the ones
4517 that will really count) with the new default value. */
4518 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
4519 else if (tmpl_default != NULL_TREE)
4520 /* Update the new parameters, too; they'll be used as the
4521 parameters for any members. */
4522 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
4528 /* Simplify EXPR if it is a non-dependent expression. Returns the
4529 (possibly simplified) expression. */
4532 fold_non_dependent_expr (tree expr)
4534 if (expr == NULL_TREE)
4537 /* If we're in a template, but EXPR isn't value dependent, simplify
4538 it. We're supposed to treat:
4540 template <typename T> void f(T[1 + 1]);
4541 template <typename T> void f(T[2]);
4543 as two declarations of the same function, for example. */
4544 if (processing_template_decl
4545 && !type_dependent_expression_p (expr)
4546 && !value_dependent_expression_p (expr))
4548 HOST_WIDE_INT saved_processing_template_decl;
4550 saved_processing_template_decl = processing_template_decl;
4551 processing_template_decl = 0;
4552 expr = tsubst_copy_and_build (expr,
4555 /*in_decl=*/NULL_TREE,
4556 /*function_p=*/false,
4557 /*integral_constant_expression_p=*/true);
4558 processing_template_decl = saved_processing_template_decl;
4563 /* EXPR is an expression which is used in a constant-expression context.
4564 For instance, it could be a VAR_DECL with a constant initializer.
4565 Extract the innermost constant expression.
4567 This is basically a more powerful version of
4568 integral_constant_value, which can be used also in templates where
4569 initializers can maintain a syntactic rather than semantic form
4570 (even if they are non-dependent, for access-checking purposes). */
4573 fold_decl_constant_value (tree expr)
4575 tree const_expr = expr;
4578 expr = fold_non_dependent_expr (const_expr);
4579 const_expr = integral_constant_value (expr);
4581 while (expr != const_expr);
4586 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4587 must be a function or a pointer-to-function type, as specified
4588 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4589 and check that the resulting function has external linkage. */
4592 convert_nontype_argument_function (tree type, tree expr)
4597 fn = instantiate_type (type, fns, tf_none);
4598 if (fn == error_mark_node)
4599 return error_mark_node;
4602 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
4603 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
4604 if (TREE_CODE (fn_no_ptr) == BASELINK)
4605 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
4607 /* [temp.arg.nontype]/1
4609 A template-argument for a non-type, non-template template-parameter
4612 -- the address of an object or function with external linkage. */
4613 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
4615 error ("%qE is not a valid template argument for type %qT "
4616 "because function %qD has not external linkage",
4617 expr, type, fn_no_ptr);
4624 /* Attempt to convert the non-type template parameter EXPR to the
4625 indicated TYPE. If the conversion is successful, return the
4626 converted value. If the conversion is unsuccessful, return
4627 NULL_TREE if we issued an error message, or error_mark_node if we
4628 did not. We issue error messages for out-and-out bad template
4629 parameters, but not simply because the conversion failed, since we
4630 might be just trying to do argument deduction. Both TYPE and EXPR
4631 must be non-dependent.
4633 The conversion follows the special rules described in
4634 [temp.arg.nontype], and it is much more strict than an implicit
4637 This function is called twice for each template argument (see
4638 lookup_template_class for a more accurate description of this
4639 problem). This means that we need to handle expressions which
4640 are not valid in a C++ source, but can be created from the
4641 first call (for instance, casts to perform conversions). These
4642 hacks can go away after we fix the double coercion problem. */
4645 convert_nontype_argument (tree type, tree expr)
4649 /* Detect immediately string literals as invalid non-type argument.
4650 This special-case is not needed for correctness (we would easily
4651 catch this later), but only to provide better diagnostic for this
4652 common user mistake. As suggested by DR 100, we do not mention
4653 linkage issues in the diagnostic as this is not the point. */
4654 if (TREE_CODE (expr) == STRING_CST)
4656 error ("%qE is not a valid template argument for type %qT "
4657 "because string literals can never be used in this context",
4662 /* If we are in a template, EXPR may be non-dependent, but still
4663 have a syntactic, rather than semantic, form. For example, EXPR
4664 might be a SCOPE_REF, rather than the VAR_DECL to which the
4665 SCOPE_REF refers. Preserving the qualifying scope is necessary
4666 so that access checking can be performed when the template is
4667 instantiated -- but here we need the resolved form so that we can
4668 convert the argument. */
4669 expr = fold_non_dependent_expr (expr);
4670 if (error_operand_p (expr))
4671 return error_mark_node;
4672 expr_type = TREE_TYPE (expr);
4674 /* HACK: Due to double coercion, we can get a
4675 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4676 which is the tree that we built on the first call (see
4677 below when coercing to reference to object or to reference to
4678 function). We just strip everything and get to the arg.
4679 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4681 if (TREE_CODE (expr) == NOP_EXPR)
4683 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
4685 /* ??? Maybe we could use convert_from_reference here, but we
4686 would need to relax its constraints because the NOP_EXPR
4687 could actually change the type to something more cv-qualified,
4688 and this is not folded by convert_from_reference. */
4689 tree addr = TREE_OPERAND (expr, 0);
4690 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
4691 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
4692 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
4693 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4694 (TREE_TYPE (expr_type),
4695 TREE_TYPE (TREE_TYPE (addr))));
4697 expr = TREE_OPERAND (addr, 0);
4698 expr_type = TREE_TYPE (expr);
4701 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4702 parameter is a pointer to object, through decay and
4703 qualification conversion. Let's strip everything. */
4704 else if (TYPE_PTROBV_P (type))
4707 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
4708 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
4709 /* Skip the ADDR_EXPR only if it is part of the decay for
4710 an array. Otherwise, it is part of the original argument
4711 in the source code. */
4712 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
4713 expr = TREE_OPERAND (expr, 0);
4714 expr_type = TREE_TYPE (expr);
4718 /* [temp.arg.nontype]/5, bullet 1
4720 For a non-type template-parameter of integral or enumeration type,
4721 integral promotions (_conv.prom_) and integral conversions
4722 (_conv.integral_) are applied. */
4723 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4725 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (expr_type))
4726 return error_mark_node;
4728 expr = fold_decl_constant_value (expr);
4729 /* Notice that there are constant expressions like '4 % 0' which
4730 do not fold into integer constants. */
4731 if (TREE_CODE (expr) != INTEGER_CST)
4733 error ("%qE is not a valid template argument for type %qT "
4734 "because it is a non-constant expression", expr, type);
4738 /* At this point, an implicit conversion does what we want,
4739 because we already know that the expression is of integral
4741 expr = ocp_convert (type, expr, CONV_IMPLICIT, LOOKUP_PROTECT);
4742 if (expr == error_mark_node)
4743 return error_mark_node;
4745 /* Conversion was allowed: fold it to a bare integer constant. */
4748 /* [temp.arg.nontype]/5, bullet 2
4750 For a non-type template-parameter of type pointer to object,
4751 qualification conversions (_conv.qual_) and the array-to-pointer
4752 conversion (_conv.array_) are applied. */
4753 else if (TYPE_PTROBV_P (type))
4755 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
4757 A template-argument for a non-type, non-template template-parameter
4758 shall be one of: [...]
4760 -- the name of a non-type template-parameter;
4761 -- the address of an object or function with external linkage, [...]
4762 expressed as "& id-expression" where the & is optional if the name
4763 refers to a function or array, or if the corresponding
4764 template-parameter is a reference.
4766 Here, we do not care about functions, as they are invalid anyway
4767 for a parameter of type pointer-to-object. */
4769 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
4770 /* Non-type template parameters are OK. */
4772 else if (TREE_CODE (expr) != ADDR_EXPR
4773 && TREE_CODE (expr_type) != ARRAY_TYPE)
4775 if (TREE_CODE (expr) == VAR_DECL)
4777 error ("%qD is not a valid template argument "
4778 "because %qD is a variable, not the address of "
4783 /* Other values, like integer constants, might be valid
4784 non-type arguments of some other type. */
4785 return error_mark_node;
4791 decl = ((TREE_CODE (expr) == ADDR_EXPR)
4792 ? TREE_OPERAND (expr, 0) : expr);
4793 if (TREE_CODE (decl) != VAR_DECL)
4795 error ("%qE is not a valid template argument of type %qT "
4796 "because %qE is not a variable",
4800 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
4802 error ("%qE is not a valid template argument of type %qT "
4803 "because %qD does not have external linkage",
4809 expr = decay_conversion (expr);
4810 if (expr == error_mark_node)
4811 return error_mark_node;
4813 expr = perform_qualification_conversions (type, expr);
4814 if (expr == error_mark_node)
4815 return error_mark_node;
4817 /* [temp.arg.nontype]/5, bullet 3
4819 For a non-type template-parameter of type reference to object, no
4820 conversions apply. The type referred to by the reference may be more
4821 cv-qualified than the (otherwise identical) type of the
4822 template-argument. The template-parameter is bound directly to the
4823 template-argument, which must be an lvalue. */
4824 else if (TYPE_REF_OBJ_P (type))
4826 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
4828 return error_mark_node;
4830 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
4832 error ("%qE is not a valid template argument for type %qT "
4833 "because of conflicts in cv-qualification", expr, type);
4837 if (!real_lvalue_p (expr))
4839 error ("%qE is not a valid template argument for type %qT "
4840 "because it is not an lvalue", expr, type);
4844 /* [temp.arg.nontype]/1
4846 A template-argument for a non-type, non-template template-parameter
4847 shall be one of: [...]
4849 -- the address of an object or function with external linkage. */
4850 if (!DECL_EXTERNAL_LINKAGE_P (expr))
4852 error ("%qE is not a valid template argument for type %qT "
4853 "because object %qD has not external linkage",
4858 expr = build_nop (type, build_address (expr));
4860 /* [temp.arg.nontype]/5, bullet 4
4862 For a non-type template-parameter of type pointer to function, only
4863 the function-to-pointer conversion (_conv.func_) is applied. If the
4864 template-argument represents a set of overloaded functions (or a
4865 pointer to such), the matching function is selected from the set
4867 else if (TYPE_PTRFN_P (type))
4869 /* If the argument is a template-id, we might not have enough
4870 context information to decay the pointer. */
4871 if (!type_unknown_p (expr_type))
4873 expr = decay_conversion (expr);
4874 if (expr == error_mark_node)
4875 return error_mark_node;
4878 expr = convert_nontype_argument_function (type, expr);
4879 if (!expr || expr == error_mark_node)
4882 if (TREE_CODE (expr) != ADDR_EXPR)
4884 error ("%qE is not a valid template argument for type %qT", expr, type);
4885 error ("it must be the address of a function with external linkage");
4889 /* [temp.arg.nontype]/5, bullet 5
4891 For a non-type template-parameter of type reference to function, no
4892 conversions apply. If the template-argument represents a set of
4893 overloaded functions, the matching function is selected from the set
4895 else if (TYPE_REFFN_P (type))
4897 if (TREE_CODE (expr) == ADDR_EXPR)
4899 error ("%qE is not a valid template argument for type %qT "
4900 "because it is a pointer", expr, type);
4901 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
4905 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
4906 if (!expr || expr == error_mark_node)
4909 expr = build_nop (type, build_address (expr));
4911 /* [temp.arg.nontype]/5, bullet 6
4913 For a non-type template-parameter of type pointer to member function,
4914 no conversions apply. If the template-argument represents a set of
4915 overloaded member functions, the matching member function is selected
4916 from the set (_over.over_). */
4917 else if (TYPE_PTRMEMFUNC_P (type))
4919 expr = instantiate_type (type, expr, tf_none);
4920 if (expr == error_mark_node)
4921 return error_mark_node;
4923 /* There is no way to disable standard conversions in
4924 resolve_address_of_overloaded_function (called by
4925 instantiate_type). It is possible that the call succeeded by
4926 converting &B::I to &D::I (where B is a base of D), so we need
4927 to reject this conversion here.
4929 Actually, even if there was a way to disable standard conversions,
4930 it would still be better to reject them here so that we can
4931 provide a superior diagnostic. */
4932 if (!same_type_p (TREE_TYPE (expr), type))
4934 /* Make sure we are just one standard conversion off. */
4935 gcc_assert (can_convert (type, TREE_TYPE (expr)));
4936 error ("%qE is not a valid template argument for type %qT "
4937 "because it is of type %qT", expr, type,
4939 inform (input_location, "standard conversions are not allowed in this context");
4943 /* [temp.arg.nontype]/5, bullet 7
4945 For a non-type template-parameter of type pointer to data member,
4946 qualification conversions (_conv.qual_) are applied. */
4947 else if (TYPE_PTRMEM_P (type))
4949 expr = perform_qualification_conversions (type, expr);
4950 if (expr == error_mark_node)
4953 /* A template non-type parameter must be one of the above. */
4957 /* Sanity check: did we actually convert the argument to the
4959 gcc_assert (same_type_p (type, TREE_TYPE (expr)));
4963 /* Subroutine of coerce_template_template_parms, which returns 1 if
4964 PARM_PARM and ARG_PARM match using the rule for the template
4965 parameters of template template parameters. Both PARM and ARG are
4966 template parameters; the rest of the arguments are the same as for
4967 coerce_template_template_parms.
4970 coerce_template_template_parm (tree parm,
4972 tsubst_flags_t complain,
4976 if (arg == NULL_TREE || arg == error_mark_node
4977 || parm == NULL_TREE || parm == error_mark_node)
4980 if (TREE_CODE (arg) != TREE_CODE (parm))
4983 switch (TREE_CODE (parm))
4986 /* We encounter instantiations of templates like
4987 template <template <template <class> class> class TT>
4990 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
4991 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
4993 if (!coerce_template_template_parms
4994 (parmparm, argparm, complain, in_decl, outer_args))
5000 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5001 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5002 /* Argument is a parameter pack but parameter is not. */
5007 /* The tsubst call is used to handle cases such as
5009 template <int> class C {};
5010 template <class T, template <T> class TT> class D {};
5013 i.e. the parameter list of TT depends on earlier parameters. */
5014 if (!uses_template_parms (TREE_TYPE (arg))
5016 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5020 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5021 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5022 /* Argument is a parameter pack but parameter is not. */
5035 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5036 template template parameters. Both PARM_PARMS and ARG_PARMS are
5037 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5040 Consider the example:
5041 template <class T> class A;
5042 template<template <class U> class TT> class B;
5044 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5045 the parameters to A, and OUTER_ARGS contains A. */
5048 coerce_template_template_parms (tree parm_parms,
5050 tsubst_flags_t complain,
5054 int nparms, nargs, i;
5058 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5059 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5061 nparms = TREE_VEC_LENGTH (parm_parms);
5062 nargs = TREE_VEC_LENGTH (arg_parms);
5064 /* Determine whether we have a parameter pack at the end of the
5065 template template parameter's template parameter list. */
5066 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5068 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5070 if (parm == error_mark_node)
5073 switch (TREE_CODE (parm))
5077 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5082 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5092 && !(variadic_p && nargs >= nparms - 1))
5095 /* Check all of the template parameters except the parameter pack at
5096 the end (if any). */
5097 for (i = 0; i < nparms - variadic_p; ++i)
5099 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5100 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5103 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5104 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5106 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5114 /* Check each of the template parameters in the template
5115 argument against the template parameter pack at the end of
5116 the template template parameter. */
5117 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5120 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5122 for (; i < nargs; ++i)
5124 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5127 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5129 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5138 /* Verifies that the deduced template arguments (in TARGS) for the
5139 template template parameters (in TPARMS) represent valid bindings,
5140 by comparing the template parameter list of each template argument
5141 to the template parameter list of its corresponding template
5142 template parameter, in accordance with DR150. This
5143 routine can only be called after all template arguments have been
5144 deduced. It will return TRUE if all of the template template
5145 parameter bindings are okay, FALSE otherwise. */
5147 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5149 int i, ntparms = TREE_VEC_LENGTH (tparms);
5152 /* We're dealing with template parms in this process. */
5153 ++processing_template_decl;
5155 targs = INNERMOST_TEMPLATE_ARGS (targs);
5157 for (i = 0; i < ntparms; ++i)
5159 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5160 tree targ = TREE_VEC_ELT (targs, i);
5162 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5164 tree packed_args = NULL_TREE;
5167 if (ARGUMENT_PACK_P (targ))
5169 /* Look inside the argument pack. */
5170 packed_args = ARGUMENT_PACK_ARGS (targ);
5171 len = TREE_VEC_LENGTH (packed_args);
5174 for (idx = 0; idx < len; ++idx)
5176 tree targ_parms = NULL_TREE;
5179 /* Extract the next argument from the argument
5181 targ = TREE_VEC_ELT (packed_args, idx);
5183 if (PACK_EXPANSION_P (targ))
5184 /* Look at the pattern of the pack expansion. */
5185 targ = PACK_EXPANSION_PATTERN (targ);
5187 /* Extract the template parameters from the template
5189 if (TREE_CODE (targ) == TEMPLATE_DECL)
5190 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5191 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5192 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5194 /* Verify that we can coerce the template template
5195 parameters from the template argument to the template
5196 parameter. This requires an exact match. */
5198 && !coerce_template_template_parms
5199 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5214 --processing_template_decl;
5218 /* Convert the indicated template ARG as necessary to match the
5219 indicated template PARM. Returns the converted ARG, or
5220 error_mark_node if the conversion was unsuccessful. Error and
5221 warning messages are issued under control of COMPLAIN. This
5222 conversion is for the Ith parameter in the parameter list. ARGS is
5223 the full set of template arguments deduced so far. */
5226 convert_template_argument (tree parm,
5229 tsubst_flags_t complain,
5235 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5237 if (TREE_CODE (arg) == TREE_LIST
5238 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5240 /* The template argument was the name of some
5241 member function. That's usually
5242 invalid, but static members are OK. In any
5243 case, grab the underlying fields/functions
5244 and issue an error later if required. */
5245 orig_arg = TREE_VALUE (arg);
5246 TREE_TYPE (arg) = unknown_type_node;
5251 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5252 requires_type = (TREE_CODE (parm) == TYPE_DECL
5253 || requires_tmpl_type);
5255 /* When determining whether an argument pack expansion is a template,
5256 look at the pattern. */
5257 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5258 arg = PACK_EXPANSION_PATTERN (arg);
5261 ((TREE_CODE (arg) == TEMPLATE_DECL
5262 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
5263 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5264 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
5267 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5268 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
5269 arg = TYPE_STUB_DECL (arg);
5271 is_type = TYPE_P (arg) || is_tmpl_type;
5273 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
5274 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
5276 permerror (input_location, "to refer to a type member of a template parameter, "
5277 "use %<typename %E%>", orig_arg);
5279 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
5280 TREE_OPERAND (arg, 1),
5282 complain & tf_error);
5286 if (is_type != requires_type)
5290 if (complain & tf_error)
5292 error ("type/value mismatch at argument %d in template "
5293 "parameter list for %qD",
5296 error (" expected a constant of type %qT, got %qT",
5298 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
5299 else if (requires_tmpl_type)
5300 error (" expected a class template, got %qE", orig_arg);
5302 error (" expected a type, got %qE", orig_arg);
5305 return error_mark_node;
5307 if (is_tmpl_type ^ requires_tmpl_type)
5309 if (in_decl && (complain & tf_error))
5311 error ("type/value mismatch at argument %d in template "
5312 "parameter list for %qD",
5315 error (" expected a type, got %qT", DECL_NAME (arg));
5317 error (" expected a class template, got %qT", orig_arg);
5319 return error_mark_node;
5324 if (requires_tmpl_type)
5326 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
5327 /* The number of argument required is not known yet.
5328 Just accept it for now. */
5329 val = TREE_TYPE (arg);
5332 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5335 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5337 if (coerce_template_template_parms (parmparm, argparm,
5343 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5345 if (val != error_mark_node)
5347 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
5348 val = TREE_TYPE (val);
5349 else if (TREE_CODE (val) == TYPE_PACK_EXPANSION
5350 && DECL_TEMPLATE_TEMPLATE_PARM_P (arg))
5352 val = TREE_TYPE (arg);
5353 val = make_pack_expansion (val);
5359 if (in_decl && (complain & tf_error))
5361 error ("type/value mismatch at argument %d in "
5362 "template parameter list for %qD",
5364 error (" expected a template of type %qD, got %qD",
5368 val = error_mark_node;
5374 /* We only form one instance of each template specialization.
5375 Therefore, if we use a non-canonical variant (i.e., a
5376 typedef), any future messages referring to the type will use
5377 the typedef, which is confusing if those future uses do not
5378 themselves also use the typedef. */
5380 val = strip_typedefs (val);
5384 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
5386 if (invalid_nontype_parm_type_p (t, complain))
5387 return error_mark_node;
5389 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
5391 if (same_type_p (t, TREE_TYPE (orig_arg)))
5395 /* Not sure if this is reachable, but it doesn't hurt
5397 error ("type mismatch in nontype parameter pack");
5398 val = error_mark_node;
5401 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
5402 /* We used to call digest_init here. However, digest_init
5403 will report errors, which we don't want when complain
5404 is zero. More importantly, digest_init will try too
5405 hard to convert things: for example, `0' should not be
5406 converted to pointer type at this point according to
5407 the standard. Accepting this is not merely an
5408 extension, since deciding whether or not these
5409 conversions can occur is part of determining which
5410 function template to call, or whether a given explicit
5411 argument specification is valid. */
5412 val = convert_nontype_argument (t, orig_arg);
5416 if (val == NULL_TREE)
5417 val = error_mark_node;
5418 else if (val == error_mark_node && (complain & tf_error))
5419 error ("could not convert template argument %qE to %qT", orig_arg, t);
5425 /* Coerces the remaining template arguments in INNER_ARGS (from
5426 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5427 Returns the coerced argument pack. PARM_IDX is the position of this
5428 parameter in the template parameter list. ARGS is the original
5429 template argument list. */
5431 coerce_template_parameter_pack (tree parms,
5439 tsubst_flags_t complain)
5441 tree parm = TREE_VEC_ELT (parms, parm_idx);
5442 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5445 tree packed_types = NULL_TREE;
5447 if (arg_idx > nargs)
5450 packed_args = make_tree_vec (nargs - arg_idx);
5452 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
5453 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
5455 /* When the template parameter is a non-type template
5456 parameter pack whose type uses parameter packs, we need
5457 to look at each of the template arguments
5458 separately. Build a vector of the types for these
5459 non-type template parameters in PACKED_TYPES. */
5461 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
5462 packed_types = tsubst_pack_expansion (expansion, args,
5465 if (packed_types == error_mark_node)
5466 return error_mark_node;
5468 /* Check that we have the right number of arguments. */
5470 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
5471 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
5474 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
5475 error ("wrong number of template arguments (%d, should be %d)",
5476 nargs, needed_parms);
5477 return error_mark_node;
5480 /* If we aren't able to check the actual arguments now
5481 (because they haven't been expanded yet), we can at least
5482 verify that all of the types used for the non-type
5483 template parameter pack are, in fact, valid for non-type
5484 template parameters. */
5486 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
5488 int j, len = TREE_VEC_LENGTH (packed_types);
5489 for (j = 0; j < len; ++j)
5491 tree t = TREE_VEC_ELT (packed_types, j);
5492 if (invalid_nontype_parm_type_p (t, complain))
5493 return error_mark_node;
5498 /* Convert the remaining arguments, which will be a part of the
5499 parameter pack "parm". */
5500 for (; arg_idx < nargs; ++arg_idx)
5502 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
5503 tree actual_parm = TREE_VALUE (parm);
5505 if (packed_types && !PACK_EXPANSION_P (arg))
5507 /* When we have a vector of types (corresponding to the
5508 non-type template parameter pack that uses parameter
5509 packs in its type, as mention above), and the
5510 argument is not an expansion (which expands to a
5511 currently unknown number of arguments), clone the
5512 parm and give it the next type in PACKED_TYPES. */
5513 actual_parm = copy_node (actual_parm);
5514 TREE_TYPE (actual_parm) =
5515 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
5518 if (arg != error_mark_node)
5519 arg = convert_template_argument (actual_parm,
5520 arg, new_args, complain, parm_idx,
5522 if (arg == error_mark_node)
5524 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
5527 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
5528 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
5529 argument_pack = make_node (TYPE_ARGUMENT_PACK);
5532 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
5533 TREE_TYPE (argument_pack)
5534 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
5535 TREE_CONSTANT (argument_pack) = 1;
5538 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
5539 return argument_pack;
5542 /* Convert all template arguments to their appropriate types, and
5543 return a vector containing the innermost resulting template
5544 arguments. If any error occurs, return error_mark_node. Error and
5545 warning messages are issued under control of COMPLAIN.
5547 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5548 for arguments not specified in ARGS. Otherwise, if
5549 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5550 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5551 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5555 coerce_template_parms (tree parms,
5558 tsubst_flags_t complain,
5559 bool require_all_args,
5560 bool use_default_args)
5562 int nparms, nargs, parm_idx, arg_idx, lost = 0;
5565 tree new_inner_args;
5566 int saved_unevaluated_operand;
5567 int saved_inhibit_evaluation_warnings;
5569 /* When used as a boolean value, indicates whether this is a
5570 variadic template parameter list. Since it's an int, we can also
5571 subtract it from nparms to get the number of non-variadic
5575 nparms = TREE_VEC_LENGTH (parms);
5577 /* Determine if there are any parameter packs. */
5578 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
5580 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
5581 if (template_parameter_pack_p (tparm))
5585 inner_args = INNERMOST_TEMPLATE_ARGS (args);
5586 /* If there are 0 or 1 parameter packs, we need to expand any argument
5587 packs so that we can deduce a parameter pack from some non-packed args
5588 followed by an argument pack, as in variadic85.C. If there are more
5589 than that, we need to leave argument packs intact so the arguments are
5590 assigned to the right parameter packs. This should only happen when
5591 dealing with a nested class inside a partial specialization of a class
5592 template, as in variadic92.C. */
5593 if (variadic_p <= 1)
5594 inner_args = expand_template_argument_pack (inner_args);
5596 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5597 if ((nargs > nparms && !variadic_p)
5598 || (nargs < nparms - variadic_p
5600 && (!use_default_args
5601 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
5602 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
5604 if (complain & tf_error)
5606 const char *or_more = "";
5609 or_more = " or more";
5613 error ("wrong number of template arguments (%d, should be %d%s)",
5614 nargs, nparms, or_more);
5617 error ("provided for %q+D", in_decl);
5620 return error_mark_node;
5623 /* We need to evaluate the template arguments, even though this
5624 template-id may be nested within a "sizeof". */
5625 saved_unevaluated_operand = cp_unevaluated_operand;
5626 cp_unevaluated_operand = 0;
5627 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
5628 c_inhibit_evaluation_warnings = 0;
5629 new_inner_args = make_tree_vec (nparms);
5630 new_args = add_outermost_template_args (args, new_inner_args);
5631 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
5636 /* Get the Ith template parameter. */
5637 parm = TREE_VEC_ELT (parms, parm_idx);
5639 if (parm == error_mark_node)
5641 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
5645 /* Calculate the next argument. */
5646 if (arg_idx < nargs)
5647 arg = TREE_VEC_ELT (inner_args, arg_idx);
5651 if (template_parameter_pack_p (TREE_VALUE (parm))
5652 && !(arg && ARGUMENT_PACK_P (arg)))
5654 /* All remaining arguments will be placed in the
5655 template parameter pack PARM. */
5656 arg = coerce_template_parameter_pack (parms, parm_idx, args,
5657 inner_args, arg_idx,
5661 /* Store this argument. */
5662 if (arg == error_mark_node)
5664 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
5666 /* We are done with all of the arguments. */
5673 if (PACK_EXPANSION_P (arg))
5675 if (complain & tf_error)
5677 /* FIXME this restriction was removed by N2555; see
5679 /* If ARG is a pack expansion, but PARM is not a
5680 template parameter pack (if it were, we would have
5681 handled it above), we're trying to expand into a
5682 fixed-length argument list. */
5683 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
5684 sorry ("cannot expand %<%E%> into a fixed-length "
5685 "argument list", arg);
5687 sorry ("cannot expand %<%T%> into a fixed-length "
5688 "argument list", arg);
5690 return error_mark_node;
5693 else if (require_all_args)
5694 /* There must be a default arg in this case. */
5695 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
5700 if (arg == error_mark_node)
5702 if (complain & tf_error)
5703 error ("template argument %d is invalid", arg_idx + 1);
5706 /* This only occurs if there was an error in the template
5707 parameter list itself (which we would already have
5708 reported) that we are trying to recover from, e.g., a class
5709 template with a parameter list such as
5710 template<typename..., typename>. */
5711 return error_mark_node;
5713 arg = convert_template_argument (TREE_VALUE (parm),
5714 arg, new_args, complain,
5717 if (arg == error_mark_node)
5719 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
5721 cp_unevaluated_operand = saved_unevaluated_operand;
5722 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
5725 return error_mark_node;
5727 return new_inner_args;
5730 /* Returns 1 if template args OT and NT are equivalent. */
5733 template_args_equal (tree ot, tree nt)
5738 if (TREE_CODE (nt) == TREE_VEC)
5739 /* For member templates */
5740 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
5741 else if (PACK_EXPANSION_P (ot))
5742 return PACK_EXPANSION_P (nt)
5743 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
5744 PACK_EXPANSION_PATTERN (nt));
5745 else if (ARGUMENT_PACK_P (ot))
5750 if (!ARGUMENT_PACK_P (nt))
5753 opack = ARGUMENT_PACK_ARGS (ot);
5754 npack = ARGUMENT_PACK_ARGS (nt);
5755 len = TREE_VEC_LENGTH (opack);
5756 if (TREE_VEC_LENGTH (npack) != len)
5758 for (i = 0; i < len; ++i)
5759 if (!template_args_equal (TREE_VEC_ELT (opack, i),
5760 TREE_VEC_ELT (npack, i)))
5764 else if (TYPE_P (nt))
5765 return TYPE_P (ot) && same_type_p (ot, nt);
5766 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
5769 return cp_tree_equal (ot, nt);
5772 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
5773 of template arguments. Returns 0 otherwise. */
5776 comp_template_args (tree oldargs, tree newargs)
5780 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
5783 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
5785 tree nt = TREE_VEC_ELT (newargs, i);
5786 tree ot = TREE_VEC_ELT (oldargs, i);
5788 if (! template_args_equal (ot, nt))
5795 add_pending_template (tree d)
5797 tree ti = (TYPE_P (d)
5798 ? CLASSTYPE_TEMPLATE_INFO (d)
5799 : DECL_TEMPLATE_INFO (d));
5800 struct pending_template *pt;
5803 if (TI_PENDING_TEMPLATE_FLAG (ti))
5806 /* We are called both from instantiate_decl, where we've already had a
5807 tinst_level pushed, and instantiate_template, where we haven't.
5809 level = !current_tinst_level || current_tinst_level->decl != d;
5812 push_tinst_level (d);
5814 pt = GGC_NEW (struct pending_template);
5816 pt->tinst = current_tinst_level;
5817 if (last_pending_template)
5818 last_pending_template->next = pt;
5820 pending_templates = pt;
5822 last_pending_template = pt;
5824 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
5831 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
5832 ARGLIST. Valid choices for FNS are given in the cp-tree.def
5833 documentation for TEMPLATE_ID_EXPR. */
5836 lookup_template_function (tree fns, tree arglist)
5840 if (fns == error_mark_node || arglist == error_mark_node)
5841 return error_mark_node;
5843 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
5844 gcc_assert (fns && (is_overloaded_fn (fns)
5845 || TREE_CODE (fns) == IDENTIFIER_NODE));
5847 if (BASELINK_P (fns))
5849 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
5851 BASELINK_FUNCTIONS (fns),
5856 type = TREE_TYPE (fns);
5857 if (TREE_CODE (fns) == OVERLOAD || !type)
5858 type = unknown_type_node;
5860 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
5863 /* Within the scope of a template class S<T>, the name S gets bound
5864 (in build_self_reference) to a TYPE_DECL for the class, not a
5865 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
5866 or one of its enclosing classes, and that type is a template,
5867 return the associated TEMPLATE_DECL. Otherwise, the original
5868 DECL is returned. */
5871 maybe_get_template_decl_from_type_decl (tree decl)
5873 return (decl != NULL_TREE
5874 && TREE_CODE (decl) == TYPE_DECL
5875 && DECL_ARTIFICIAL (decl)
5876 && CLASS_TYPE_P (TREE_TYPE (decl))
5877 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
5878 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
5881 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
5882 parameters, find the desired type.
5884 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
5886 IN_DECL, if non-NULL, is the template declaration we are trying to
5889 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
5890 the class we are looking up.
5892 Issue error and warning messages under control of COMPLAIN.
5894 If the template class is really a local class in a template
5895 function, then the FUNCTION_CONTEXT is the function in which it is
5898 ??? Note that this function is currently called *twice* for each
5899 template-id: the first time from the parser, while creating the
5900 incomplete type (finish_template_type), and the second type during the
5901 real instantiation (instantiate_template_class). This is surely something
5902 that we want to avoid. It also causes some problems with argument
5903 coercion (see convert_nontype_argument for more information on this). */
5906 lookup_template_class (tree d1,
5911 tsubst_flags_t complain)
5913 tree templ = NULL_TREE, parmlist;
5920 timevar_push (TV_NAME_LOOKUP);
5922 if (TREE_CODE (d1) == IDENTIFIER_NODE)
5924 tree value = innermost_non_namespace_value (d1);
5925 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
5930 push_decl_namespace (context);
5931 templ = lookup_name (d1);
5932 templ = maybe_get_template_decl_from_type_decl (templ);
5934 pop_decl_namespace ();
5937 context = DECL_CONTEXT (templ);
5939 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
5941 tree type = TREE_TYPE (d1);
5943 /* If we are declaring a constructor, say A<T>::A<T>, we will get
5944 an implicit typename for the second A. Deal with it. */
5945 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
5946 type = TREE_TYPE (type);
5948 if (CLASSTYPE_TEMPLATE_INFO (type))
5950 templ = CLASSTYPE_TI_TEMPLATE (type);
5951 d1 = DECL_NAME (templ);
5954 else if (TREE_CODE (d1) == ENUMERAL_TYPE
5955 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
5957 templ = TYPE_TI_TEMPLATE (d1);
5958 d1 = DECL_NAME (templ);
5960 else if (TREE_CODE (d1) == TEMPLATE_DECL
5961 && DECL_TEMPLATE_RESULT (d1)
5962 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
5965 d1 = DECL_NAME (templ);
5966 context = DECL_CONTEXT (templ);
5969 /* Issue an error message if we didn't find a template. */
5972 if (complain & tf_error)
5973 error ("%qT is not a template", d1);
5974 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5977 if (TREE_CODE (templ) != TEMPLATE_DECL
5978 /* Make sure it's a user visible template, if it was named by
5980 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
5981 && !PRIMARY_TEMPLATE_P (templ)))
5983 if (complain & tf_error)
5985 error ("non-template type %qT used as a template", d1);
5987 error ("for template declaration %q+D", in_decl);
5989 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5992 complain &= ~tf_user;
5994 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
5996 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
5997 template arguments */
6003 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6005 /* Consider an example where a template template parameter declared as
6007 template <class T, class U = std::allocator<T> > class TT
6009 The template parameter level of T and U are one level larger than
6010 of TT. To proper process the default argument of U, say when an
6011 instantiation `TT<int>' is seen, we need to build the full
6012 arguments containing {int} as the innermost level. Outer levels,
6013 available when not appearing as default template argument, can be
6014 obtained from the arguments of the enclosing template.
6016 Suppose that TT is later substituted with std::vector. The above
6017 instantiation is `TT<int, std::allocator<T> >' with TT at
6018 level 1, and T at level 2, while the template arguments at level 1
6019 becomes {std::vector} and the inner level 2 is {int}. */
6021 outer = DECL_CONTEXT (templ);
6023 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6024 else if (current_template_parms)
6025 /* This is an argument of the current template, so we haven't set
6026 DECL_CONTEXT yet. */
6027 outer = current_template_args ();
6030 arglist = add_to_template_args (outer, arglist);
6032 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6034 /*require_all_args=*/true,
6035 /*use_default_args=*/true);
6036 if (arglist2 == error_mark_node
6037 || (!uses_template_parms (arglist2)
6038 && check_instantiated_args (templ, arglist2, complain)))
6039 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6041 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6042 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
6046 tree template_type = TREE_TYPE (templ);
6049 tree found = NULL_TREE;
6052 int is_partial_instantiation;
6054 gen_tmpl = most_general_template (templ);
6055 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6056 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6057 arg_depth = TMPL_ARGS_DEPTH (arglist);
6059 if (arg_depth == 1 && parm_depth > 1)
6061 /* We've been given an incomplete set of template arguments.
6064 template <class T> struct S1 {
6065 template <class U> struct S2 {};
6066 template <class U> struct S2<U*> {};
6069 we will be called with an ARGLIST of `U*', but the
6070 TEMPLATE will be `template <class T> template
6071 <class U> struct S1<T>::S2'. We must fill in the missing
6074 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6076 arg_depth = TMPL_ARGS_DEPTH (arglist);
6079 /* Now we should have enough arguments. */
6080 gcc_assert (parm_depth == arg_depth);
6082 /* From here on, we're only interested in the most general
6085 /* Calculate the BOUND_ARGS. These will be the args that are
6086 actually tsubst'd into the definition to create the
6090 /* We have multiple levels of arguments to coerce, at once. */
6092 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6094 tree bound_args = make_tree_vec (parm_depth);
6096 for (i = saved_depth,
6097 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6098 i > 0 && t != NULL_TREE;
6099 --i, t = TREE_CHAIN (t))
6101 tree a = coerce_template_parms (TREE_VALUE (t),
6104 /*require_all_args=*/true,
6105 /*use_default_args=*/true);
6107 /* Don't process further if one of the levels fails. */
6108 if (a == error_mark_node)
6110 /* Restore the ARGLIST to its full size. */
6111 TREE_VEC_LENGTH (arglist) = saved_depth;
6112 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6115 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6117 /* We temporarily reduce the length of the ARGLIST so
6118 that coerce_template_parms will see only the arguments
6119 corresponding to the template parameters it is
6121 TREE_VEC_LENGTH (arglist)--;
6124 /* Restore the ARGLIST to its full size. */
6125 TREE_VEC_LENGTH (arglist) = saved_depth;
6127 arglist = bound_args;
6131 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6132 INNERMOST_TEMPLATE_ARGS (arglist),
6135 /*require_all_args=*/true,
6136 /*use_default_args=*/true);
6138 if (arglist == error_mark_node)
6139 /* We were unable to bind the arguments. */
6140 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6142 /* In the scope of a template class, explicit references to the
6143 template class refer to the type of the template, not any
6144 instantiation of it. For example, in:
6146 template <class T> class C { void f(C<T>); }
6148 the `C<T>' is just the same as `C'. Outside of the
6149 class, however, such a reference is an instantiation. */
6151 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6152 || currently_open_class (template_type))
6153 /* comp_template_args is expensive, check it last. */
6154 && comp_template_args (TYPE_TI_ARGS (template_type),
6156 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
6158 /* If we already have this specialization, return it. */
6159 elt.tmpl = gen_tmpl;
6161 hash = hash_specialization (&elt);
6162 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6166 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, entry->spec);
6168 /* This type is a "partial instantiation" if any of the template
6169 arguments still involve template parameters. Note that we set
6170 IS_PARTIAL_INSTANTIATION for partial specializations as
6172 is_partial_instantiation = uses_template_parms (arglist);
6174 /* If the deduced arguments are invalid, then the binding
6176 if (!is_partial_instantiation
6177 && check_instantiated_args (gen_tmpl,
6178 INNERMOST_TEMPLATE_ARGS (arglist),
6180 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6182 if (!is_partial_instantiation
6183 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6184 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6186 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6187 DECL_NAME (gen_tmpl),
6188 /*tag_scope=*/ts_global);
6189 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
6192 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
6195 context = global_namespace;
6197 /* Create the type. */
6198 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
6200 if (!is_partial_instantiation)
6202 set_current_access_from_decl (TYPE_NAME (template_type));
6203 t = start_enum (TYPE_IDENTIFIER (template_type),
6204 tsubst (ENUM_UNDERLYING_TYPE (template_type),
6205 arglist, complain, in_decl),
6206 SCOPED_ENUM_P (template_type));
6210 /* We don't want to call start_enum for this type, since
6211 the values for the enumeration constants may involve
6212 template parameters. And, no one should be interested
6213 in the enumeration constants for such a type. */
6214 t = make_node (ENUMERAL_TYPE);
6215 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
6220 t = make_class_type (TREE_CODE (template_type));
6221 CLASSTYPE_DECLARED_CLASS (t)
6222 = CLASSTYPE_DECLARED_CLASS (template_type);
6223 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
6224 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
6226 /* A local class. Make sure the decl gets registered properly. */
6227 if (context == current_function_decl)
6228 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
6230 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
6231 /* This instantiation is another name for the primary
6232 template type. Set the TYPE_CANONICAL field
6234 TYPE_CANONICAL (t) = template_type;
6235 else if (any_template_arguments_need_structural_equality_p (arglist))
6236 /* Some of the template arguments require structural
6237 equality testing, so this template class requires
6238 structural equality testing. */
6239 SET_TYPE_STRUCTURAL_EQUALITY (t);
6242 /* If we called start_enum or pushtag above, this information
6243 will already be set up. */
6246 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
6248 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
6249 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
6250 TYPE_STUB_DECL (t) = type_decl;
6251 DECL_SOURCE_LOCATION (type_decl)
6252 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
6255 type_decl = TYPE_NAME (t);
6257 TREE_PRIVATE (type_decl)
6258 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
6259 TREE_PROTECTED (type_decl)
6260 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
6261 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
6263 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
6264 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
6267 /* Set up the template information. We have to figure out which
6268 template is the immediate parent if this is a full
6270 if (parm_depth == 1 || is_partial_instantiation
6271 || !PRIMARY_TEMPLATE_P (gen_tmpl))
6272 /* This case is easy; there are no member templates involved. */
6276 /* This is a full instantiation of a member template. Find
6277 the partial instantiation of which this is an instance. */
6279 /* Temporarily reduce by one the number of levels in the ARGLIST
6280 so as to avoid comparing the last set of arguments. */
6281 TREE_VEC_LENGTH (arglist)--;
6282 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
6283 TREE_VEC_LENGTH (arglist)++;
6284 found = CLASSTYPE_TI_TEMPLATE (found);
6287 SET_TYPE_TEMPLATE_INFO (t, tree_cons (found, arglist, NULL_TREE));
6290 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
6291 &elt, hash, INSERT);
6292 *slot = GGC_NEW (spec_entry);
6295 /* Note this use of the partial instantiation so we can check it
6296 later in maybe_process_partial_specialization. */
6297 DECL_TEMPLATE_INSTANTIATIONS (templ)
6298 = tree_cons (arglist, t,
6299 DECL_TEMPLATE_INSTANTIATIONS (templ));
6301 if (TREE_CODE (t) == ENUMERAL_TYPE
6302 && !is_partial_instantiation)
6303 /* Now that the type has been registered on the instantiations
6304 list, we set up the enumerators. Because the enumeration
6305 constants may involve the enumeration type itself, we make
6306 sure to register the type first, and then create the
6307 constants. That way, doing tsubst_expr for the enumeration
6308 constants won't result in recursive calls here; we'll find
6309 the instantiation and exit above. */
6310 tsubst_enum (template_type, t, arglist);
6312 if (is_partial_instantiation)
6313 /* If the type makes use of template parameters, the
6314 code that generates debugging information will crash. */
6315 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
6317 /* Possibly limit visibility based on template args. */
6318 TREE_PUBLIC (type_decl) = 1;
6319 determine_visibility (type_decl);
6321 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
6323 timevar_pop (TV_NAME_LOOKUP);
6330 /* True when we should also visit template parameters that occur in
6331 non-deduced contexts. */
6332 bool include_nondeduced_p;
6333 struct pointer_set_t *visited;
6336 /* Called from for_each_template_parm via walk_tree. */
6339 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
6342 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
6343 tree_fn_t fn = pfd->fn;
6344 void *data = pfd->data;
6347 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
6348 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
6349 pfd->include_nondeduced_p))
6350 return error_mark_node;
6352 switch (TREE_CODE (t))
6355 if (TYPE_PTRMEMFUNC_P (t))
6361 if (!TYPE_TEMPLATE_INFO (t))
6363 else if (for_each_template_parm (TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
6364 fn, data, pfd->visited,
6365 pfd->include_nondeduced_p))
6366 return error_mark_node;
6370 if (for_each_template_parm (TYPE_MIN_VALUE (t),
6371 fn, data, pfd->visited,
6372 pfd->include_nondeduced_p)
6373 || for_each_template_parm (TYPE_MAX_VALUE (t),
6374 fn, data, pfd->visited,
6375 pfd->include_nondeduced_p))
6376 return error_mark_node;
6380 /* Since we're not going to walk subtrees, we have to do this
6382 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
6383 pfd->visited, pfd->include_nondeduced_p))
6384 return error_mark_node;
6388 /* Check the return type. */
6389 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6390 pfd->include_nondeduced_p))
6391 return error_mark_node;
6393 /* Check the parameter types. Since default arguments are not
6394 instantiated until they are needed, the TYPE_ARG_TYPES may
6395 contain expressions that involve template parameters. But,
6396 no-one should be looking at them yet. And, once they're
6397 instantiated, they don't contain template parameters, so
6398 there's no point in looking at them then, either. */
6402 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
6403 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
6404 pfd->visited, pfd->include_nondeduced_p))
6405 return error_mark_node;
6407 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6408 want walk_tree walking into them itself. */
6414 if (pfd->include_nondeduced_p
6415 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
6417 pfd->include_nondeduced_p))
6418 return error_mark_node;
6423 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
6424 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
6425 pfd->visited, pfd->include_nondeduced_p))
6426 return error_mark_node;
6431 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
6432 && for_each_template_parm (DECL_INITIAL (t), fn, data,
6433 pfd->visited, pfd->include_nondeduced_p))
6434 return error_mark_node;
6435 if (DECL_CONTEXT (t)
6436 && pfd->include_nondeduced_p
6437 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
6438 pfd->visited, pfd->include_nondeduced_p))
6439 return error_mark_node;
6442 case BOUND_TEMPLATE_TEMPLATE_PARM:
6443 /* Record template parameters such as `T' inside `TT<T>'. */
6444 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
6445 pfd->include_nondeduced_p))
6446 return error_mark_node;
6449 case TEMPLATE_TEMPLATE_PARM:
6450 case TEMPLATE_TYPE_PARM:
6451 case TEMPLATE_PARM_INDEX:
6452 if (fn && (*fn)(t, data))
6453 return error_mark_node;
6455 return error_mark_node;
6459 /* A template template parameter is encountered. */
6460 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
6461 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6462 pfd->include_nondeduced_p))
6463 return error_mark_node;
6465 /* Already substituted template template parameter */
6471 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
6473 pfd->include_nondeduced_p))
6474 return error_mark_node;
6478 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
6479 && pfd->include_nondeduced_p
6480 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
6481 (TREE_TYPE (t)), fn, data,
6482 pfd->visited, pfd->include_nondeduced_p))
6483 return error_mark_node;
6488 /* If there's no type, then this thing must be some expression
6489 involving template parameters. */
6490 if (!fn && !TREE_TYPE (t))
6491 return error_mark_node;
6496 case REINTERPRET_CAST_EXPR:
6497 case CONST_CAST_EXPR:
6498 case STATIC_CAST_EXPR:
6499 case DYNAMIC_CAST_EXPR:
6503 case PSEUDO_DTOR_EXPR:
6505 return error_mark_node;
6512 /* We didn't find any template parameters we liked. */
6516 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6517 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6518 call FN with the parameter and the DATA.
6519 If FN returns nonzero, the iteration is terminated, and
6520 for_each_template_parm returns 1. Otherwise, the iteration
6521 continues. If FN never returns a nonzero value, the value
6522 returned by for_each_template_parm is 0. If FN is NULL, it is
6523 considered to be the function which always returns 1.
6525 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6526 parameters that occur in non-deduced contexts. When false, only
6527 visits those template parameters that can be deduced. */
6530 for_each_template_parm (tree t, tree_fn_t fn, void* data,
6531 struct pointer_set_t *visited,
6532 bool include_nondeduced_p)
6534 struct pair_fn_data pfd;
6540 pfd.include_nondeduced_p = include_nondeduced_p;
6542 /* Walk the tree. (Conceptually, we would like to walk without
6543 duplicates, but for_each_template_parm_r recursively calls
6544 for_each_template_parm, so we would need to reorganize a fair
6545 bit to use walk_tree_without_duplicates, so we keep our own
6548 pfd.visited = visited;
6550 pfd.visited = pointer_set_create ();
6551 result = cp_walk_tree (&t,
6552 for_each_template_parm_r,
6554 pfd.visited) != NULL_TREE;
6559 pointer_set_destroy (pfd.visited);
6566 /* Returns true if T depends on any template parameter. */
6569 uses_template_parms (tree t)
6572 int saved_processing_template_decl;
6574 saved_processing_template_decl = processing_template_decl;
6575 if (!saved_processing_template_decl)
6576 processing_template_decl = 1;
6578 dependent_p = dependent_type_p (t);
6579 else if (TREE_CODE (t) == TREE_VEC)
6580 dependent_p = any_dependent_template_arguments_p (t);
6581 else if (TREE_CODE (t) == TREE_LIST)
6582 dependent_p = (uses_template_parms (TREE_VALUE (t))
6583 || uses_template_parms (TREE_CHAIN (t)));
6584 else if (TREE_CODE (t) == TYPE_DECL)
6585 dependent_p = dependent_type_p (TREE_TYPE (t));
6588 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
6589 || TREE_CODE (t) == OVERLOAD
6590 || TREE_CODE (t) == BASELINK
6591 || TREE_CODE (t) == IDENTIFIER_NODE
6592 || TREE_CODE (t) == TRAIT_EXPR
6593 || TREE_CODE (t) == CONSTRUCTOR
6594 || CONSTANT_CLASS_P (t))
6595 dependent_p = (type_dependent_expression_p (t)
6596 || value_dependent_expression_p (t));
6599 gcc_assert (t == error_mark_node);
6600 dependent_p = false;
6603 processing_template_decl = saved_processing_template_decl;
6608 /* Returns true if T depends on any template parameter with level LEVEL. */
6611 uses_template_parms_level (tree t, int level)
6613 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
6614 /*include_nondeduced_p=*/true);
6617 static int tinst_depth;
6618 extern int max_tinst_depth;
6619 #ifdef GATHER_STATISTICS
6622 static int tinst_level_tick;
6623 static int last_template_error_tick;
6625 /* We're starting to instantiate D; record the template instantiation context
6626 for diagnostics and to restore it later. */
6629 push_tinst_level (tree d)
6631 struct tinst_level *new_level;
6633 if (tinst_depth >= max_tinst_depth)
6635 /* If the instantiation in question still has unbound template parms,
6636 we don't really care if we can't instantiate it, so just return.
6637 This happens with base instantiation for implicit `typename'. */
6638 if (uses_template_parms (d))
6641 last_template_error_tick = tinst_level_tick;
6642 error ("template instantiation depth exceeds maximum of %d (use "
6643 "-ftemplate-depth-NN to increase the maximum) instantiating %qD",
6644 max_tinst_depth, d);
6646 print_instantiation_context ();
6651 new_level = GGC_NEW (struct tinst_level);
6652 new_level->decl = d;
6653 new_level->locus = input_location;
6654 new_level->in_system_header_p = in_system_header;
6655 new_level->next = current_tinst_level;
6656 current_tinst_level = new_level;
6659 #ifdef GATHER_STATISTICS
6660 if (tinst_depth > depth_reached)
6661 depth_reached = tinst_depth;
6668 /* We're done instantiating this template; return to the instantiation
6672 pop_tinst_level (void)
6674 /* Restore the filename and line number stashed away when we started
6675 this instantiation. */
6676 input_location = current_tinst_level->locus;
6677 current_tinst_level = current_tinst_level->next;
6682 /* We're instantiating a deferred template; restore the template
6683 instantiation context in which the instantiation was requested, which
6684 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
6687 reopen_tinst_level (struct tinst_level *level)
6689 struct tinst_level *t;
6692 for (t = level; t; t = t->next)
6695 current_tinst_level = level;
6700 /* Returns the TINST_LEVEL which gives the original instantiation
6703 struct tinst_level *
6704 outermost_tinst_level (void)
6706 struct tinst_level *level = current_tinst_level;
6709 level = level->next;
6713 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
6716 parameter_of_template_p (tree parm, tree templ)
6721 if (!parm || !templ)
6724 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
6725 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
6727 parms = DECL_TEMPLATE_PARMS (templ);
6728 parms = INNERMOST_TEMPLATE_PARMS (parms);
6730 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
6731 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
6737 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
6738 vector of template arguments, as for tsubst.
6740 Returns an appropriate tsubst'd friend declaration. */
6743 tsubst_friend_function (tree decl, tree args)
6747 if (TREE_CODE (decl) == FUNCTION_DECL
6748 && DECL_TEMPLATE_INSTANTIATION (decl)
6749 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
6750 /* This was a friend declared with an explicit template
6751 argument list, e.g.:
6755 to indicate that f was a template instantiation, not a new
6756 function declaration. Now, we have to figure out what
6757 instantiation of what template. */
6759 tree template_id, arglist, fns;
6762 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
6764 /* Friend functions are looked up in the containing namespace scope.
6765 We must enter that scope, to avoid finding member functions of the
6766 current class with same name. */
6767 push_nested_namespace (ns);
6768 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
6769 tf_warning_or_error, NULL_TREE,
6770 /*integral_constant_expression_p=*/false);
6771 pop_nested_namespace (ns);
6772 arglist = tsubst (DECL_TI_ARGS (decl), args,
6773 tf_warning_or_error, NULL_TREE);
6774 template_id = lookup_template_function (fns, arglist);
6776 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6777 tmpl = determine_specialization (template_id, new_friend,
6779 /*need_member_template=*/0,
6780 TREE_VEC_LENGTH (args),
6782 return instantiate_template (tmpl, new_args, tf_error);
6785 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6787 /* The NEW_FRIEND will look like an instantiation, to the
6788 compiler, but is not an instantiation from the point of view of
6789 the language. For example, we might have had:
6791 template <class T> struct S {
6792 template <class U> friend void f(T, U);
6795 Then, in S<int>, template <class U> void f(int, U) is not an
6796 instantiation of anything. */
6797 if (new_friend == error_mark_node)
6798 return error_mark_node;
6800 DECL_USE_TEMPLATE (new_friend) = 0;
6801 if (TREE_CODE (decl) == TEMPLATE_DECL)
6803 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
6804 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
6805 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
6808 /* The mangled name for the NEW_FRIEND is incorrect. The function
6809 is not a template instantiation and should not be mangled like
6810 one. Therefore, we forget the mangling here; we'll recompute it
6811 later if we need it. */
6812 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
6814 SET_DECL_RTL (new_friend, NULL_RTX);
6815 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
6818 if (DECL_NAMESPACE_SCOPE_P (new_friend))
6821 tree new_friend_template_info;
6822 tree new_friend_result_template_info;
6824 int new_friend_is_defn;
6826 /* We must save some information from NEW_FRIEND before calling
6827 duplicate decls since that function will free NEW_FRIEND if
6829 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
6830 new_friend_is_defn =
6831 (DECL_INITIAL (DECL_TEMPLATE_RESULT
6832 (template_for_substitution (new_friend)))
6834 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
6836 /* This declaration is a `primary' template. */
6837 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
6839 new_friend_result_template_info
6840 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
6843 new_friend_result_template_info = NULL_TREE;
6845 /* Make the init_value nonzero so pushdecl knows this is a defn. */
6846 if (new_friend_is_defn)
6847 DECL_INITIAL (new_friend) = error_mark_node;
6849 /* Inside pushdecl_namespace_level, we will push into the
6850 current namespace. However, the friend function should go
6851 into the namespace of the template. */
6852 ns = decl_namespace_context (new_friend);
6853 push_nested_namespace (ns);
6854 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
6855 pop_nested_namespace (ns);
6857 if (old_decl == error_mark_node)
6858 return error_mark_node;
6860 if (old_decl != new_friend)
6862 /* This new friend declaration matched an existing
6863 declaration. For example, given:
6865 template <class T> void f(T);
6866 template <class U> class C {
6867 template <class T> friend void f(T) {}
6870 the friend declaration actually provides the definition
6871 of `f', once C has been instantiated for some type. So,
6872 old_decl will be the out-of-class template declaration,
6873 while new_friend is the in-class definition.
6875 But, if `f' was called before this point, the
6876 instantiation of `f' will have DECL_TI_ARGS corresponding
6877 to `T' but not to `U', references to which might appear
6878 in the definition of `f'. Previously, the most general
6879 template for an instantiation of `f' was the out-of-class
6880 version; now it is the in-class version. Therefore, we
6881 run through all specialization of `f', adding to their
6882 DECL_TI_ARGS appropriately. In particular, they need a
6883 new set of outer arguments, corresponding to the
6884 arguments for this class instantiation.
6886 The same situation can arise with something like this:
6889 template <class T> class C {
6893 when `C<int>' is instantiated. Now, `f(int)' is defined
6896 if (!new_friend_is_defn)
6897 /* On the other hand, if the in-class declaration does
6898 *not* provide a definition, then we don't want to alter
6899 existing definitions. We can just leave everything
6904 tree new_template = TI_TEMPLATE (new_friend_template_info);
6905 tree new_args = TI_ARGS (new_friend_template_info);
6907 /* Overwrite whatever template info was there before, if
6908 any, with the new template information pertaining to
6910 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
6912 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
6913 /* We should have called reregister_specialization in
6915 gcc_assert (retrieve_specialization (new_template,
6922 /* Indicate that the old function template is a partial
6924 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
6925 = new_friend_result_template_info;
6927 gcc_assert (new_template
6928 == most_general_template (new_template));
6929 gcc_assert (new_template != old_decl);
6931 /* Reassign any specializations already in the hash table
6932 to the new more general template, and add the
6933 additional template args. */
6934 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
6938 tree spec = TREE_VALUE (t);
6941 elt.tmpl = old_decl;
6942 elt.args = DECL_TI_ARGS (spec);
6943 elt.spec = NULL_TREE;
6945 htab_remove_elt (decl_specializations, &elt);
6948 = add_outermost_template_args (new_args,
6949 DECL_TI_ARGS (spec));
6951 register_specialization
6952 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
6955 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
6959 /* The information from NEW_FRIEND has been merged into OLD_DECL
6960 by duplicate_decls. */
6961 new_friend = old_decl;
6966 tree context = DECL_CONTEXT (new_friend);
6970 template <class T> class C {
6971 template <class U> friend void C1<U>::f (); // case 1
6972 friend void C2<T>::f (); // case 2
6974 we only need to make sure CONTEXT is a complete type for
6975 case 2. To distinguish between the two cases, we note that
6976 CONTEXT of case 1 remains dependent type after tsubst while
6977 this isn't true for case 2. */
6978 ++processing_template_decl;
6979 dependent_p = dependent_type_p (context);
6980 --processing_template_decl;
6983 && !complete_type_or_else (context, NULL_TREE))
6984 return error_mark_node;
6986 if (COMPLETE_TYPE_P (context))
6988 /* Check to see that the declaration is really present, and,
6989 possibly obtain an improved declaration. */
6990 tree fn = check_classfn (context,
6991 new_friend, NULL_TREE);
7001 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7002 template arguments, as for tsubst.
7004 Returns an appropriate tsubst'd friend type or error_mark_node on
7008 tsubst_friend_class (tree friend_tmpl, tree args)
7014 context = DECL_CONTEXT (friend_tmpl);
7018 if (TREE_CODE (context) == NAMESPACE_DECL)
7019 push_nested_namespace (context);
7021 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7024 /* Look for a class template declaration. We look for hidden names
7025 because two friend declarations of the same template are the
7026 same. For example, in:
7029 template <typename> friend class F;
7031 template <typename> struct B {
7032 template <typename> friend class F;
7035 both F templates are the same. */
7036 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7037 /*block_p=*/true, 0,
7038 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7040 /* But, if we don't find one, it might be because we're in a
7041 situation like this:
7049 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7050 for `S<int>', not the TEMPLATE_DECL. */
7051 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7053 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7054 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7057 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7059 /* The friend template has already been declared. Just
7060 check to see that the declarations match, and install any new
7061 default parameters. We must tsubst the default parameters,
7062 of course. We only need the innermost template parameters
7063 because that is all that redeclare_class_template will look
7065 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7066 > TMPL_ARGS_DEPTH (args))
7069 location_t saved_input_location;
7070 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7071 args, tf_warning_or_error);
7073 saved_input_location = input_location;
7074 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7075 redeclare_class_template (TREE_TYPE (tmpl), parms);
7076 input_location = saved_input_location;
7080 friend_type = TREE_TYPE (tmpl);
7084 /* The friend template has not already been declared. In this
7085 case, the instantiation of the template class will cause the
7086 injection of this template into the global scope. */
7087 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7088 if (tmpl == error_mark_node)
7089 return error_mark_node;
7091 /* The new TMPL is not an instantiation of anything, so we
7092 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7093 the new type because that is supposed to be the corresponding
7094 template decl, i.e., TMPL. */
7095 DECL_USE_TEMPLATE (tmpl) = 0;
7096 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7097 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7098 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7099 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7101 /* Inject this template into the global scope. */
7102 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7107 if (TREE_CODE (context) == NAMESPACE_DECL)
7108 pop_nested_namespace (context);
7110 pop_nested_class ();
7116 /* Returns zero if TYPE cannot be completed later due to circularity.
7117 Otherwise returns one. */
7120 can_complete_type_without_circularity (tree type)
7122 if (type == NULL_TREE || type == error_mark_node)
7124 else if (COMPLETE_TYPE_P (type))
7126 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
7127 return can_complete_type_without_circularity (TREE_TYPE (type));
7128 else if (CLASS_TYPE_P (type)
7129 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
7135 /* Apply any attributes which had to be deferred until instantiation
7136 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7137 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7140 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
7141 tree args, tsubst_flags_t complain, tree in_decl)
7143 tree last_dep = NULL_TREE;
7147 for (t = attributes; t; t = TREE_CHAIN (t))
7148 if (ATTR_IS_DEPENDENT (t))
7151 attributes = copy_list (attributes);
7155 if (DECL_P (*decl_p))
7157 if (TREE_TYPE (*decl_p) == error_mark_node)
7159 p = &DECL_ATTRIBUTES (*decl_p);
7162 p = &TYPE_ATTRIBUTES (*decl_p);
7166 tree late_attrs = NULL_TREE;
7167 tree *q = &late_attrs;
7169 for (*p = attributes; *p; )
7172 if (ATTR_IS_DEPENDENT (t))
7174 *p = TREE_CHAIN (t);
7175 TREE_CHAIN (t) = NULL_TREE;
7176 /* If the first attribute argument is an identifier, don't
7177 pass it through tsubst. Attributes like mode, format,
7178 cleanup and several target specific attributes expect it
7181 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
7182 && TREE_VALUE (TREE_VALUE (t))
7183 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
7184 == IDENTIFIER_NODE))
7187 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
7189 /*integral_constant_expression_p=*/false);
7190 if (chain != TREE_CHAIN (TREE_VALUE (t)))
7192 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
7197 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
7198 /*integral_constant_expression_p=*/false);
7200 q = &TREE_CHAIN (t);
7203 p = &TREE_CHAIN (t);
7206 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
7210 /* Perform (or defer) access check for typedefs that were referenced
7211 from within the template TMPL code.
7212 This is a subroutine of instantiate_template and instantiate_class_template.
7213 TMPL is the template to consider and TARGS is the list of arguments of
7217 perform_typedefs_access_check (tree tmpl, tree targs)
7222 || (!CLASS_TYPE_P (tmpl)
7223 && TREE_CODE (tmpl) != FUNCTION_DECL))
7226 for (t = get_types_needing_access_check (tmpl); t; t = TREE_CHAIN (t))
7228 tree type_decl = TREE_PURPOSE (t);
7229 tree type_scope = TREE_VALUE (t);
7231 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
7234 if (uses_template_parms (type_decl))
7235 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
7236 if (uses_template_parms (type_scope))
7237 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
7239 perform_or_defer_access_check (TYPE_BINFO (type_scope),
7240 type_decl, type_decl);
7245 instantiate_class_template (tree type)
7247 tree templ, args, pattern, t, member;
7252 if (type == error_mark_node)
7253 return error_mark_node;
7255 if (TYPE_BEING_DEFINED (type)
7256 || COMPLETE_TYPE_P (type)
7257 || dependent_type_p (type))
7260 /* Figure out which template is being instantiated. */
7261 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
7262 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7264 /* Determine what specialization of the original template to
7266 t = most_specialized_class (type, templ);
7267 if (t == error_mark_node)
7269 TYPE_BEING_DEFINED (type) = 1;
7270 return error_mark_node;
7274 /* This TYPE is actually an instantiation of a partial
7275 specialization. We replace the innermost set of ARGS with
7276 the arguments appropriate for substitution. For example,
7279 template <class T> struct S {};
7280 template <class T> struct S<T*> {};
7282 and supposing that we are instantiating S<int*>, ARGS will
7283 presently be {int*} -- but we need {int}. */
7284 pattern = TREE_TYPE (t);
7285 args = TREE_PURPOSE (t);
7289 pattern = TREE_TYPE (templ);
7290 args = CLASSTYPE_TI_ARGS (type);
7293 /* If the template we're instantiating is incomplete, then clearly
7294 there's nothing we can do. */
7295 if (!COMPLETE_TYPE_P (pattern))
7298 /* If we've recursively instantiated too many templates, stop. */
7299 if (! push_tinst_level (type))
7302 /* Now we're really doing the instantiation. Mark the type as in
7303 the process of being defined. */
7304 TYPE_BEING_DEFINED (type) = 1;
7306 /* We may be in the middle of deferred access check. Disable
7308 push_deferring_access_checks (dk_no_deferred);
7310 push_to_top_level ();
7312 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
7314 /* Set the input location to the most specialized template definition.
7315 This is needed if tsubsting causes an error. */
7316 typedecl = TYPE_MAIN_DECL (pattern);
7317 input_location = DECL_SOURCE_LOCATION (typedecl);
7319 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
7320 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
7321 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
7322 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
7323 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
7324 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
7325 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
7326 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
7327 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
7328 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
7329 TYPE_PACKED (type) = TYPE_PACKED (pattern);
7330 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
7331 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
7332 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
7333 if (ANON_AGGR_TYPE_P (pattern))
7334 SET_ANON_AGGR_TYPE_P (type);
7335 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
7337 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
7338 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
7341 pbinfo = TYPE_BINFO (pattern);
7343 /* We should never instantiate a nested class before its enclosing
7344 class; we need to look up the nested class by name before we can
7345 instantiate it, and that lookup should instantiate the enclosing
7347 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
7348 || COMPLETE_TYPE_P (TYPE_CONTEXT (type))
7349 || TYPE_BEING_DEFINED (TYPE_CONTEXT (type)));
7351 base_list = NULL_TREE;
7352 if (BINFO_N_BASE_BINFOS (pbinfo))
7355 tree context = TYPE_CONTEXT (type);
7359 /* We must enter the scope containing the type, as that is where
7360 the accessibility of types named in dependent bases are
7362 pushed_scope = push_scope (context ? context : global_namespace);
7364 /* Substitute into each of the bases to determine the actual
7366 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
7369 tree access = BINFO_BASE_ACCESS (pbinfo, i);
7370 tree expanded_bases = NULL_TREE;
7373 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
7376 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
7377 args, tf_error, NULL_TREE);
7378 if (expanded_bases == error_mark_node)
7381 len = TREE_VEC_LENGTH (expanded_bases);
7384 for (idx = 0; idx < len; idx++)
7387 /* Extract the already-expanded base class. */
7388 base = TREE_VEC_ELT (expanded_bases, idx);
7390 /* Substitute to figure out the base class. */
7391 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
7394 if (base == error_mark_node)
7397 base_list = tree_cons (access, base, base_list);
7398 if (BINFO_VIRTUAL_P (pbase_binfo))
7399 TREE_TYPE (base_list) = integer_type_node;
7403 /* The list is now in reverse order; correct that. */
7404 base_list = nreverse (base_list);
7407 pop_scope (pushed_scope);
7409 /* Now call xref_basetypes to set up all the base-class
7411 xref_basetypes (type, base_list);
7413 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
7414 (int) ATTR_FLAG_TYPE_IN_PLACE,
7415 args, tf_error, NULL_TREE);
7417 /* Now that our base classes are set up, enter the scope of the
7418 class, so that name lookups into base classes, etc. will work
7419 correctly. This is precisely analogous to what we do in
7420 begin_class_definition when defining an ordinary non-template
7421 class, except we also need to push the enclosing classes. */
7422 push_nested_class (type);
7424 /* Now members are processed in the order of declaration. */
7425 for (member = CLASSTYPE_DECL_LIST (pattern);
7426 member; member = TREE_CHAIN (member))
7428 tree t = TREE_VALUE (member);
7430 if (TREE_PURPOSE (member))
7434 /* Build new CLASSTYPE_NESTED_UTDS. */
7437 bool class_template_p;
7439 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
7440 && TYPE_LANG_SPECIFIC (t)
7441 && CLASSTYPE_IS_TEMPLATE (t));
7442 /* If the member is a class template, then -- even after
7443 substitution -- there may be dependent types in the
7444 template argument list for the class. We increment
7445 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7446 that function will assume that no types are dependent
7447 when outside of a template. */
7448 if (class_template_p)
7449 ++processing_template_decl;
7450 newtag = tsubst (t, args, tf_error, NULL_TREE);
7451 if (class_template_p)
7452 --processing_template_decl;
7453 if (newtag == error_mark_node)
7456 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
7458 tree name = TYPE_IDENTIFIER (t);
7460 if (class_template_p)
7461 /* Unfortunately, lookup_template_class sets
7462 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7463 instantiation (i.e., for the type of a member
7464 template class nested within a template class.)
7465 This behavior is required for
7466 maybe_process_partial_specialization to work
7467 correctly, but is not accurate in this case;
7468 the TAG is not an instantiation of anything.
7469 (The corresponding TEMPLATE_DECL is an
7470 instantiation, but the TYPE is not.) */
7471 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
7473 /* Now, we call pushtag to put this NEWTAG into the scope of
7474 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7475 pushtag calling push_template_decl. We don't have to do
7476 this for enums because it will already have been done in
7479 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
7480 pushtag (name, newtag, /*tag_scope=*/ts_current);
7483 else if (TREE_CODE (t) == FUNCTION_DECL
7484 || DECL_FUNCTION_TEMPLATE_P (t))
7486 /* Build new TYPE_METHODS. */
7489 if (TREE_CODE (t) == TEMPLATE_DECL)
7490 ++processing_template_decl;
7491 r = tsubst (t, args, tf_error, NULL_TREE);
7492 if (TREE_CODE (t) == TEMPLATE_DECL)
7493 --processing_template_decl;
7494 set_current_access_from_decl (r);
7495 finish_member_declaration (r);
7499 /* Build new TYPE_FIELDS. */
7500 if (TREE_CODE (t) == STATIC_ASSERT)
7503 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
7504 tf_warning_or_error, NULL_TREE,
7505 /*integral_constant_expression_p=*/true);
7506 finish_static_assert (condition,
7507 STATIC_ASSERT_MESSAGE (t),
7508 STATIC_ASSERT_SOURCE_LOCATION (t),
7511 else if (TREE_CODE (t) != CONST_DECL)
7515 /* The file and line for this declaration, to
7516 assist in error message reporting. Since we
7517 called push_tinst_level above, we don't need to
7519 input_location = DECL_SOURCE_LOCATION (t);
7521 if (TREE_CODE (t) == TEMPLATE_DECL)
7522 ++processing_template_decl;
7523 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
7524 if (TREE_CODE (t) == TEMPLATE_DECL)
7525 --processing_template_decl;
7526 if (TREE_CODE (r) == VAR_DECL)
7530 [t]he initialization (and any associated
7531 side-effects) of a static data member does
7532 not occur unless the static data member is
7533 itself used in a way that requires the
7534 definition of the static data member to
7537 Therefore, we do not substitute into the
7538 initialized for the static data member here. */
7539 finish_static_data_member_decl
7542 /*init_const_expr_p=*/false,
7543 /*asmspec_tree=*/NULL_TREE,
7545 if (DECL_INITIALIZED_IN_CLASS_P (r))
7546 check_static_variable_definition (r, TREE_TYPE (r));
7548 else if (TREE_CODE (r) == FIELD_DECL)
7550 /* Determine whether R has a valid type and can be
7551 completed later. If R is invalid, then it is
7552 replaced by error_mark_node so that it will not be
7553 added to TYPE_FIELDS. */
7554 tree rtype = TREE_TYPE (r);
7555 if (can_complete_type_without_circularity (rtype))
7556 complete_type (rtype);
7558 if (!COMPLETE_TYPE_P (rtype))
7560 cxx_incomplete_type_error (r, rtype);
7561 r = error_mark_node;
7565 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7566 such a thing will already have been added to the field
7567 list by tsubst_enum in finish_member_declaration in the
7568 CLASSTYPE_NESTED_UTDS case above. */
7569 if (!(TREE_CODE (r) == TYPE_DECL
7570 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
7571 && DECL_ARTIFICIAL (r)))
7573 set_current_access_from_decl (r);
7574 finish_member_declaration (r);
7581 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
7583 /* Build new CLASSTYPE_FRIEND_CLASSES. */
7585 tree friend_type = t;
7586 bool adjust_processing_template_decl = false;
7588 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7590 /* template <class T> friend class C; */
7591 friend_type = tsubst_friend_class (friend_type, args);
7592 adjust_processing_template_decl = true;
7594 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
7596 /* template <class T> friend class C::D; */
7597 friend_type = tsubst (friend_type, args,
7598 tf_warning_or_error, NULL_TREE);
7599 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7600 friend_type = TREE_TYPE (friend_type);
7601 adjust_processing_template_decl = true;
7603 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
7605 /* This could be either
7609 when dependent_type_p is false or
7611 template <class U> friend class T::C;
7614 friend_type = tsubst (friend_type, args,
7615 tf_warning_or_error, NULL_TREE);
7616 /* Bump processing_template_decl for correct
7617 dependent_type_p calculation. */
7618 ++processing_template_decl;
7619 if (dependent_type_p (friend_type))
7620 adjust_processing_template_decl = true;
7621 --processing_template_decl;
7623 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
7624 && hidden_name_p (TYPE_NAME (friend_type)))
7628 where C hasn't been declared yet. Let's lookup name
7629 from namespace scope directly, bypassing any name that
7630 come from dependent base class. */
7631 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
7633 /* The call to xref_tag_from_type does injection for friend
7635 push_nested_namespace (ns);
7637 xref_tag_from_type (friend_type, NULL_TREE,
7638 /*tag_scope=*/ts_current);
7639 pop_nested_namespace (ns);
7641 else if (uses_template_parms (friend_type))
7642 /* friend class C<T>; */
7643 friend_type = tsubst (friend_type, args,
7644 tf_warning_or_error, NULL_TREE);
7649 where C is already declared or
7651 friend class C<int>;
7653 We don't have to do anything in these cases. */
7655 if (adjust_processing_template_decl)
7656 /* Trick make_friend_class into realizing that the friend
7657 we're adding is a template, not an ordinary class. It's
7658 important that we use make_friend_class since it will
7659 perform some error-checking and output cross-reference
7661 ++processing_template_decl;
7663 if (friend_type != error_mark_node)
7664 make_friend_class (type, friend_type, /*complain=*/false);
7666 if (adjust_processing_template_decl)
7667 --processing_template_decl;
7671 /* Build new DECL_FRIENDLIST. */
7674 /* The file and line for this declaration, to
7675 assist in error message reporting. Since we
7676 called push_tinst_level above, we don't need to
7678 input_location = DECL_SOURCE_LOCATION (t);
7680 if (TREE_CODE (t) == TEMPLATE_DECL)
7682 ++processing_template_decl;
7683 push_deferring_access_checks (dk_no_check);
7686 r = tsubst_friend_function (t, args);
7687 add_friend (type, r, /*complain=*/false);
7688 if (TREE_CODE (t) == TEMPLATE_DECL)
7690 pop_deferring_access_checks ();
7691 --processing_template_decl;
7697 /* Set the file and line number information to whatever is given for
7698 the class itself. This puts error messages involving generated
7699 implicit functions at a predictable point, and the same point
7700 that would be used for non-template classes. */
7701 input_location = DECL_SOURCE_LOCATION (typedecl);
7703 unreverse_member_declarations (type);
7704 finish_struct_1 (type);
7705 TYPE_BEING_DEFINED (type) = 0;
7707 /* Now that the class is complete, instantiate default arguments for
7708 any member functions. We don't do this earlier because the
7709 default arguments may reference members of the class. */
7710 if (!PRIMARY_TEMPLATE_P (templ))
7711 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
7712 if (TREE_CODE (t) == FUNCTION_DECL
7713 /* Implicitly generated member functions will not have template
7714 information; they are not instantiations, but instead are
7715 created "fresh" for each instantiation. */
7716 && DECL_TEMPLATE_INFO (t))
7717 tsubst_default_arguments (t);
7719 /* Some typedefs referenced from within the template code need to be access
7720 checked at template instantiation time, i.e now. These types were
7721 added to the template at parsing time. Let's get those and perform
7722 the access checks then. */
7723 perform_typedefs_access_check (pattern, args);
7724 perform_deferred_access_checks ();
7725 pop_nested_class ();
7726 pop_from_top_level ();
7727 pop_deferring_access_checks ();
7730 /* The vtable for a template class can be emitted in any translation
7731 unit in which the class is instantiated. When there is no key
7732 method, however, finish_struct_1 will already have added TYPE to
7733 the keyed_classes list. */
7734 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
7735 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
7741 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7747 else if (TYPE_P (t))
7748 r = tsubst (t, args, complain, in_decl);
7751 r = tsubst_expr (t, args, complain, in_decl,
7752 /*integral_constant_expression_p=*/true);
7753 r = fold_non_dependent_expr (r);
7758 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
7759 NONTYPE_ARGUMENT_PACK. */
7762 make_fnparm_pack (tree spec_parm)
7764 /* Collect all of the extra "packed" parameters into an
7768 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
7769 tree argtypepack = make_node (TYPE_ARGUMENT_PACK);
7770 int i, len = list_length (spec_parm);
7772 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
7773 parmvec = make_tree_vec (len);
7774 parmtypevec = make_tree_vec (len);
7775 for (i = 0; i < len; i++, spec_parm = TREE_CHAIN (spec_parm))
7777 TREE_VEC_ELT (parmvec, i) = spec_parm;
7778 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
7781 /* Build the argument packs. */
7782 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
7783 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
7784 TREE_TYPE (argpack) = argtypepack;
7789 /* Substitute ARGS into T, which is an pack expansion
7790 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
7791 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
7792 (if only a partial substitution could be performed) or
7793 ERROR_MARK_NODE if there was an error. */
7795 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
7799 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
7800 tree first_arg_pack; int i, len = -1;
7803 bool very_local_specializations = false;
7805 gcc_assert (PACK_EXPANSION_P (t));
7806 pattern = PACK_EXPANSION_PATTERN (t);
7808 /* Determine the argument packs that will instantiate the parameter
7809 packs used in the expansion expression. While we're at it,
7810 compute the number of arguments to be expanded and make sure it
7812 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
7813 pack = TREE_CHAIN (pack))
7815 tree parm_pack = TREE_VALUE (pack);
7816 tree arg_pack = NULL_TREE;
7817 tree orig_arg = NULL_TREE;
7819 if (TREE_CODE (parm_pack) == PARM_DECL)
7821 arg_pack = retrieve_local_specialization (parm_pack);
7822 if (arg_pack == NULL_TREE)
7824 /* This can happen for a parameter name used later in a function
7825 declaration (such as in a late-specified return type). Just
7826 make a dummy decl, since it's only used for its type. */
7827 gcc_assert (cp_unevaluated_operand != 0);
7828 arg_pack = tsubst_decl (parm_pack, args, complain);
7829 arg_pack = make_fnparm_pack (arg_pack);
7834 int level, idx, levels;
7835 template_parm_level_and_index (parm_pack, &level, &idx);
7837 levels = TMPL_ARGS_DEPTH (args);
7838 if (level <= levels)
7839 arg_pack = TMPL_ARG (args, level, idx);
7842 orig_arg = arg_pack;
7843 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
7844 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
7846 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
7847 /* This can only happen if we forget to expand an argument
7848 pack somewhere else. Just return an error, silently. */
7850 result = make_tree_vec (1);
7851 TREE_VEC_ELT (result, 0) = error_mark_node;
7856 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
7857 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
7859 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
7860 tree pattern = PACK_EXPANSION_PATTERN (expansion);
7861 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
7862 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
7863 /* The argument pack that the parameter maps to is just an
7864 expansion of the parameter itself, such as one would
7865 find in the implicit typedef of a class inside the
7866 class itself. Consider this parameter "unsubstituted",
7867 so that we will maintain the outer pack expansion. */
7868 arg_pack = NULL_TREE;
7874 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
7876 /* It's all-or-nothing with incomplete argument packs. */
7877 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
7878 return error_mark_node;
7880 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
7886 first_arg_pack = arg_pack;
7888 else if (len != my_len)
7890 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
7891 error ("mismatched argument pack lengths while expanding "
7895 error ("mismatched argument pack lengths while expanding "
7898 return error_mark_node;
7901 /* Keep track of the parameter packs and their corresponding
7903 packs = tree_cons (parm_pack, arg_pack, packs);
7904 TREE_TYPE (packs) = orig_arg;
7907 /* We can't substitute for this parameter pack. */
7908 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
7910 unsubstituted_packs);
7913 /* We cannot expand this expansion expression, because we don't have
7914 all of the argument packs we need. Substitute into the pattern
7915 and return a PACK_EXPANSION_*. The caller will need to deal with
7917 if (unsubstituted_packs)
7920 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
7921 new_pat = tsubst_expr (pattern, args, complain, in_decl,
7922 /*integral_constant_expression_p=*/false);
7924 new_pat = tsubst (pattern, args, complain, in_decl);
7925 return make_pack_expansion (new_pat);
7928 /* We could not find any argument packs that work. */
7930 return error_mark_node;
7932 if (!local_specializations)
7934 /* We're in a late-specified return type, so we don't have a local
7935 specializations table. Create one for doing this expansion. */
7936 very_local_specializations = true;
7937 local_specializations = htab_create (37,
7938 hash_local_specialization,
7939 eq_local_specializations,
7943 /* For each argument in each argument pack, substitute into the
7945 result = make_tree_vec (len + incomplete);
7946 for (i = 0; i < len + incomplete; ++i)
7948 /* For parameter pack, change the substitution of the parameter
7949 pack to the ith argument in its argument pack, then expand
7951 for (pack = packs; pack; pack = TREE_CHAIN (pack))
7953 tree parm = TREE_PURPOSE (pack);
7955 if (TREE_CODE (parm) == PARM_DECL)
7957 /* Select the Ith argument from the pack. */
7958 tree arg = make_node (ARGUMENT_PACK_SELECT);
7959 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
7960 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
7962 register_local_specialization (arg, parm);
7968 template_parm_level_and_index (parm, &level, &idx);
7972 /* Select the Ith argument from the pack. */
7973 value = make_node (ARGUMENT_PACK_SELECT);
7974 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
7975 ARGUMENT_PACK_SELECT_INDEX (value) = i;
7978 /* Update the corresponding argument. */
7979 TMPL_ARG (args, level, idx) = value;
7983 /* Substitute into the PATTERN with the altered arguments. */
7984 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
7985 TREE_VEC_ELT (result, i) =
7986 tsubst_expr (pattern, args, complain, in_decl,
7987 /*integral_constant_expression_p=*/false);
7989 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
7992 /* When we have incomplete argument packs, the last "expanded"
7993 result is itself a pack expansion, which allows us
7994 to deduce more arguments. */
7995 TREE_VEC_ELT (result, i) =
7996 make_pack_expansion (TREE_VEC_ELT (result, i));
7998 if (TREE_VEC_ELT (result, i) == error_mark_node)
8000 result = error_mark_node;
8005 /* Update ARGS to restore the substitution from parameter packs to
8006 their argument packs. */
8007 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8009 tree parm = TREE_PURPOSE (pack);
8011 if (TREE_CODE (parm) == PARM_DECL)
8012 register_local_specialization (TREE_TYPE (pack), parm);
8016 template_parm_level_and_index (parm, &level, &idx);
8018 /* Update the corresponding argument. */
8019 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8020 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8023 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8027 if (very_local_specializations)
8029 htab_delete (local_specializations);
8030 local_specializations = NULL;
8036 /* Substitute ARGS into the vector or list of template arguments T. */
8039 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8042 int len = TREE_VEC_LENGTH (t);
8043 int need_new = 0, i, expanded_len_adjust = 0, out;
8044 tree *elts = (tree *) alloca (len * sizeof (tree));
8046 for (i = 0; i < len; i++)
8048 tree orig_arg = TREE_VEC_ELT (t, i);
8051 if (TREE_CODE (orig_arg) == TREE_VEC)
8052 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
8053 else if (PACK_EXPANSION_P (orig_arg))
8055 /* Substitute into an expansion expression. */
8056 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
8058 if (TREE_CODE (new_arg) == TREE_VEC)
8059 /* Add to the expanded length adjustment the number of
8060 expanded arguments. We subtract one from this
8061 measurement, because the argument pack expression
8062 itself is already counted as 1 in
8063 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8064 the argument pack is empty. */
8065 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
8067 else if (ARGUMENT_PACK_P (orig_arg))
8069 /* Substitute into each of the arguments. */
8070 new_arg = make_node (TREE_CODE (orig_arg));
8072 SET_ARGUMENT_PACK_ARGS (
8074 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
8075 args, complain, in_decl));
8077 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
8078 new_arg = error_mark_node;
8080 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
8081 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
8083 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
8085 if (TREE_TYPE (new_arg) == error_mark_node)
8086 new_arg = error_mark_node;
8090 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
8092 if (new_arg == error_mark_node)
8093 return error_mark_node;
8096 if (new_arg != orig_arg)
8103 /* Make space for the expanded arguments coming from template
8105 t = make_tree_vec (len + expanded_len_adjust);
8106 for (i = 0, out = 0; i < len; i++)
8108 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
8109 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
8110 && TREE_CODE (elts[i]) == TREE_VEC)
8114 /* Now expand the template argument pack "in place". */
8115 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
8116 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
8120 TREE_VEC_ELT (t, out) = elts[i];
8128 /* Return the result of substituting ARGS into the template parameters
8129 given by PARMS. If there are m levels of ARGS and m + n levels of
8130 PARMS, then the result will contain n levels of PARMS. For
8131 example, if PARMS is `template <class T> template <class U>
8132 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8133 result will be `template <int*, double, class V>'. */
8136 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
8141 /* When substituting into a template, we must set
8142 PROCESSING_TEMPLATE_DECL as the template parameters may be
8143 dependent if they are based on one-another, and the dependency
8144 predicates are short-circuit outside of templates. */
8145 ++processing_template_decl;
8147 for (new_parms = &r;
8148 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
8149 new_parms = &(TREE_CHAIN (*new_parms)),
8150 parms = TREE_CHAIN (parms))
8153 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
8156 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
8162 if (parms == error_mark_node)
8165 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
8167 if (tuple == error_mark_node)
8170 default_value = TREE_PURPOSE (tuple);
8171 parm_decl = TREE_VALUE (tuple);
8173 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
8174 if (TREE_CODE (parm_decl) == PARM_DECL
8175 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
8176 parm_decl = error_mark_node;
8177 default_value = tsubst_template_arg (default_value, args,
8178 complain, NULL_TREE);
8180 tuple = build_tree_list (default_value, parm_decl);
8181 TREE_VEC_ELT (new_vec, i) = tuple;
8185 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
8186 - TMPL_ARGS_DEPTH (args)),
8187 new_vec, NULL_TREE);
8190 --processing_template_decl;
8195 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8196 type T. If T is not an aggregate or enumeration type, it is
8197 handled as if by tsubst. IN_DECL is as for tsubst. If
8198 ENTERING_SCOPE is nonzero, T is the context for a template which
8199 we are presently tsubst'ing. Return the substituted value. */
8202 tsubst_aggr_type (tree t,
8204 tsubst_flags_t complain,
8211 switch (TREE_CODE (t))
8214 if (TYPE_PTRMEMFUNC_P (t))
8215 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
8217 /* Else fall through. */
8220 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
8225 int saved_unevaluated_operand;
8226 int saved_inhibit_evaluation_warnings;
8228 /* In "sizeof(X<I>)" we need to evaluate "I". */
8229 saved_unevaluated_operand = cp_unevaluated_operand;
8230 cp_unevaluated_operand = 0;
8231 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
8232 c_inhibit_evaluation_warnings = 0;
8234 /* First, determine the context for the type we are looking
8236 context = TYPE_CONTEXT (t);
8239 context = tsubst_aggr_type (context, args, complain,
8240 in_decl, /*entering_scope=*/1);
8241 /* If context is a nested class inside a class template,
8242 it may still need to be instantiated (c++/33959). */
8243 if (TYPE_P (context))
8244 context = complete_type (context);
8247 /* Then, figure out what arguments are appropriate for the
8248 type we are trying to find. For example, given:
8250 template <class T> struct S;
8251 template <class T, class U> void f(T, U) { S<U> su; }
8253 and supposing that we are instantiating f<int, double>,
8254 then our ARGS will be {int, double}, but, when looking up
8255 S we only want {double}. */
8256 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
8258 if (argvec == error_mark_node)
8259 r = error_mark_node;
8262 r = lookup_template_class (t, argvec, in_decl, context,
8263 entering_scope, complain);
8264 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
8267 cp_unevaluated_operand = saved_unevaluated_operand;
8268 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
8273 /* This is not a template type, so there's nothing to do. */
8277 return tsubst (t, args, complain, in_decl);
8281 /* Substitute into the default argument ARG (a default argument for
8282 FN), which has the indicated TYPE. */
8285 tsubst_default_argument (tree fn, tree type, tree arg)
8287 tree saved_class_ptr = NULL_TREE;
8288 tree saved_class_ref = NULL_TREE;
8290 /* This default argument came from a template. Instantiate the
8291 default argument here, not in tsubst. In the case of
8300 we must be careful to do name lookup in the scope of S<T>,
8301 rather than in the current class. */
8302 push_access_scope (fn);
8303 /* The "this" pointer is not valid in a default argument. */
8306 saved_class_ptr = current_class_ptr;
8307 cp_function_chain->x_current_class_ptr = NULL_TREE;
8308 saved_class_ref = current_class_ref;
8309 cp_function_chain->x_current_class_ref = NULL_TREE;
8312 push_deferring_access_checks(dk_no_deferred);
8313 /* The default argument expression may cause implicitly defined
8314 member functions to be synthesized, which will result in garbage
8315 collection. We must treat this situation as if we were within
8316 the body of function so as to avoid collecting live data on the
8319 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
8320 tf_warning_or_error, NULL_TREE,
8321 /*integral_constant_expression_p=*/false);
8323 pop_deferring_access_checks();
8325 /* Restore the "this" pointer. */
8328 cp_function_chain->x_current_class_ptr = saved_class_ptr;
8329 cp_function_chain->x_current_class_ref = saved_class_ref;
8332 /* Make sure the default argument is reasonable. */
8333 arg = check_default_argument (type, arg);
8335 pop_access_scope (fn);
8340 /* Substitute into all the default arguments for FN. */
8343 tsubst_default_arguments (tree fn)
8348 tmpl_args = DECL_TI_ARGS (fn);
8350 /* If this function is not yet instantiated, we certainly don't need
8351 its default arguments. */
8352 if (uses_template_parms (tmpl_args))
8355 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
8357 arg = TREE_CHAIN (arg))
8358 if (TREE_PURPOSE (arg))
8359 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
8361 TREE_PURPOSE (arg));
8364 /* Substitute the ARGS into the T, which is a _DECL. Return the
8365 result of the substitution. Issue error and warning messages under
8366 control of COMPLAIN. */
8369 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
8371 location_t saved_loc;
8376 /* Set the filename and linenumber to improve error-reporting. */
8377 saved_loc = input_location;
8378 input_location = DECL_SOURCE_LOCATION (t);
8380 switch (TREE_CODE (t))
8384 /* We can get here when processing a member function template,
8385 member class template, or template template parameter. */
8386 tree decl = DECL_TEMPLATE_RESULT (t);
8391 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
8393 /* Template template parameter is treated here. */
8394 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8395 if (new_type == error_mark_node)
8396 return error_mark_node;
8399 TREE_CHAIN (r) = NULL_TREE;
8400 TREE_TYPE (r) = new_type;
8401 DECL_TEMPLATE_RESULT (r)
8402 = build_decl (DECL_SOURCE_LOCATION (decl),
8403 TYPE_DECL, DECL_NAME (decl), new_type);
8404 DECL_TEMPLATE_PARMS (r)
8405 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8407 TYPE_NAME (new_type) = r;
8411 /* We might already have an instance of this template.
8412 The ARGS are for the surrounding class type, so the
8413 full args contain the tsubst'd args for the context,
8414 plus the innermost args from the template decl. */
8415 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
8416 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
8417 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
8418 /* Because this is a template, the arguments will still be
8419 dependent, even after substitution. If
8420 PROCESSING_TEMPLATE_DECL is not set, the dependency
8421 predicates will short-circuit. */
8422 ++processing_template_decl;
8423 full_args = tsubst_template_args (tmpl_args, args,
8425 --processing_template_decl;
8426 if (full_args == error_mark_node)
8427 return error_mark_node;
8429 /* If this is a default template template argument,
8430 tsubst might not have changed anything. */
8431 if (full_args == tmpl_args)
8434 hash = hash_tmpl_and_args (t, full_args);
8435 spec = retrieve_specialization (t, full_args, hash);
8436 if (spec != NULL_TREE)
8442 /* Make a new template decl. It will be similar to the
8443 original, but will record the current template arguments.
8444 We also create a new function declaration, which is just
8445 like the old one, but points to this new template, rather
8446 than the old one. */
8448 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
8449 TREE_CHAIN (r) = NULL_TREE;
8451 DECL_TEMPLATE_INFO (r) = build_tree_list (t, args);
8453 if (TREE_CODE (decl) == TYPE_DECL)
8456 ++processing_template_decl;
8457 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8458 --processing_template_decl;
8459 if (new_type == error_mark_node)
8460 return error_mark_node;
8462 TREE_TYPE (r) = new_type;
8463 CLASSTYPE_TI_TEMPLATE (new_type) = r;
8464 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
8465 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
8466 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
8471 ++processing_template_decl;
8472 new_decl = tsubst (decl, args, complain, in_decl);
8473 --processing_template_decl;
8474 if (new_decl == error_mark_node)
8475 return error_mark_node;
8477 DECL_TEMPLATE_RESULT (r) = new_decl;
8478 DECL_TI_TEMPLATE (new_decl) = r;
8479 TREE_TYPE (r) = TREE_TYPE (new_decl);
8480 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
8481 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
8484 SET_DECL_IMPLICIT_INSTANTIATION (r);
8485 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
8486 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
8488 /* The template parameters for this new template are all the
8489 template parameters for the old template, except the
8490 outermost level of parameters. */
8491 DECL_TEMPLATE_PARMS (r)
8492 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8495 if (PRIMARY_TEMPLATE_P (t))
8496 DECL_PRIMARY_TEMPLATE (r) = r;
8498 if (TREE_CODE (decl) != TYPE_DECL)
8499 /* Record this non-type partial instantiation. */
8500 register_specialization (r, t,
8501 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
8509 tree argvec = NULL_TREE;
8517 /* Nobody should be tsubst'ing into non-template functions. */
8518 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
8520 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
8525 /* If T is not dependent, just return it. We have to
8526 increment PROCESSING_TEMPLATE_DECL because
8527 value_dependent_expression_p assumes that nothing is
8528 dependent when PROCESSING_TEMPLATE_DECL is zero. */
8529 ++processing_template_decl;
8530 dependent_p = value_dependent_expression_p (t);
8531 --processing_template_decl;
8535 /* Calculate the most general template of which R is a
8536 specialization, and the complete set of arguments used to
8538 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
8539 argvec = tsubst_template_args (DECL_TI_ARGS
8540 (DECL_TEMPLATE_RESULT (gen_tmpl)),
8541 args, complain, in_decl);
8543 /* Check to see if we already have this specialization. */
8544 hash = hash_tmpl_and_args (gen_tmpl, argvec);
8545 spec = retrieve_specialization (gen_tmpl, argvec, hash);
8553 /* We can see more levels of arguments than parameters if
8554 there was a specialization of a member template, like
8557 template <class T> struct S { template <class U> void f(); }
8558 template <> template <class U> void S<int>::f(U);
8560 Here, we'll be substituting into the specialization,
8561 because that's where we can find the code we actually
8562 want to generate, but we'll have enough arguments for
8563 the most general template.
8565 We also deal with the peculiar case:
8567 template <class T> struct S {
8568 template <class U> friend void f();
8570 template <class U> void f() {}
8572 template void f<double>();
8574 Here, the ARGS for the instantiation of will be {int,
8575 double}. But, we only need as many ARGS as there are
8576 levels of template parameters in CODE_PATTERN. We are
8577 careful not to get fooled into reducing the ARGS in
8580 template <class T> struct S { template <class U> void f(U); }
8581 template <class T> template <> void S<T>::f(int) {}
8583 which we can spot because the pattern will be a
8584 specialization in this case. */
8585 args_depth = TMPL_ARGS_DEPTH (args);
8587 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
8588 if (args_depth > parms_depth
8589 && !DECL_TEMPLATE_SPECIALIZATION (t))
8590 args = get_innermost_template_args (args, parms_depth);
8594 /* This special case arises when we have something like this:
8596 template <class T> struct S {
8597 friend void f<int>(int, double);
8600 Here, the DECL_TI_TEMPLATE for the friend declaration
8601 will be an IDENTIFIER_NODE. We are being called from
8602 tsubst_friend_function, and we want only to create a
8603 new decl (R) with appropriate types so that we can call
8604 determine_specialization. */
8605 gen_tmpl = NULL_TREE;
8608 if (DECL_CLASS_SCOPE_P (t))
8610 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
8614 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
8615 complain, t, /*entering_scope=*/1);
8620 ctx = DECL_CONTEXT (t);
8622 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8623 if (type == error_mark_node)
8624 return error_mark_node;
8626 /* We do NOT check for matching decls pushed separately at this
8627 point, as they may not represent instantiations of this
8628 template, and in any case are considered separate under the
8631 DECL_USE_TEMPLATE (r) = 0;
8632 TREE_TYPE (r) = type;
8633 /* Clear out the mangled name and RTL for the instantiation. */
8634 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8635 SET_DECL_RTL (r, NULL_RTX);
8636 /* Leave DECL_INITIAL set on deleted instantiations. */
8637 if (!DECL_DELETED_FN (r))
8638 DECL_INITIAL (r) = NULL_TREE;
8639 DECL_CONTEXT (r) = ctx;
8641 if (member && DECL_CONV_FN_P (r))
8642 /* Type-conversion operator. Reconstruct the name, in
8643 case it's the name of one of the template's parameters. */
8644 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
8646 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
8648 DECL_RESULT (r) = NULL_TREE;
8650 TREE_STATIC (r) = 0;
8651 TREE_PUBLIC (r) = TREE_PUBLIC (t);
8652 DECL_EXTERNAL (r) = 1;
8653 /* If this is an instantiation of a function with internal
8654 linkage, we already know what object file linkage will be
8655 assigned to the instantiation. */
8656 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
8657 DECL_DEFER_OUTPUT (r) = 0;
8658 TREE_CHAIN (r) = NULL_TREE;
8659 DECL_PENDING_INLINE_INFO (r) = 0;
8660 DECL_PENDING_INLINE_P (r) = 0;
8661 DECL_SAVED_TREE (r) = NULL_TREE;
8662 DECL_STRUCT_FUNCTION (r) = NULL;
8664 /* We'll re-clone as appropriate in instantiate_template. */
8665 DECL_CLONED_FUNCTION (r) = NULL_TREE;
8667 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
8668 this in the special friend case mentioned above where
8669 GEN_TMPL is NULL. */
8672 DECL_TEMPLATE_INFO (r)
8673 = tree_cons (gen_tmpl, argvec, NULL_TREE);
8674 SET_DECL_IMPLICIT_INSTANTIATION (r);
8675 register_specialization (r, gen_tmpl, argvec, false, hash);
8677 /* We're not supposed to instantiate default arguments
8678 until they are called, for a template. But, for a
8681 template <class T> void f ()
8682 { extern void g(int i = T()); }
8684 we should do the substitution when the template is
8685 instantiated. We handle the member function case in
8686 instantiate_class_template since the default arguments
8687 might refer to other members of the class. */
8689 && !PRIMARY_TEMPLATE_P (gen_tmpl)
8690 && !uses_template_parms (argvec))
8691 tsubst_default_arguments (r);
8694 DECL_TEMPLATE_INFO (r) = NULL_TREE;
8696 /* Copy the list of befriending classes. */
8697 for (friends = &DECL_BEFRIENDING_CLASSES (r);
8699 friends = &TREE_CHAIN (*friends))
8701 *friends = copy_node (*friends);
8702 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
8707 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
8709 maybe_retrofit_in_chrg (r);
8710 if (DECL_CONSTRUCTOR_P (r))
8711 grok_ctor_properties (ctx, r);
8712 /* If this is an instantiation of a member template, clone it.
8713 If it isn't, that'll be handled by
8714 clone_constructors_and_destructors. */
8715 if (PRIMARY_TEMPLATE_P (gen_tmpl))
8716 clone_function_decl (r, /*update_method_vec_p=*/0);
8718 else if (IDENTIFIER_OPNAME_P (DECL_NAME (r))
8719 && !grok_op_properties (r, (complain & tf_error) != 0))
8720 return error_mark_node;
8722 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
8723 SET_DECL_FRIEND_CONTEXT (r,
8724 tsubst (DECL_FRIEND_CONTEXT (t),
8725 args, complain, in_decl));
8727 /* Possibly limit visibility based on template args. */
8728 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8729 if (DECL_VISIBILITY_SPECIFIED (t))
8731 DECL_VISIBILITY_SPECIFIED (r) = 0;
8733 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8735 determine_visibility (r);
8737 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8738 args, complain, in_decl);
8744 tree type = NULL_TREE;
8746 tree expanded_types = NULL_TREE;
8747 tree prev_r = NULL_TREE;
8748 tree first_r = NULL_TREE;
8750 if (FUNCTION_PARAMETER_PACK_P (t))
8752 /* If there is a local specialization that isn't a
8753 parameter pack, it means that we're doing a "simple"
8754 substitution from inside tsubst_pack_expansion. Just
8755 return the local specialization (which will be a single
8757 tree spec = retrieve_local_specialization (t);
8759 && TREE_CODE (spec) == PARM_DECL
8760 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
8763 /* Expand the TYPE_PACK_EXPANSION that provides the types for
8764 the parameters in this function parameter pack. */
8765 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
8767 if (TREE_CODE (expanded_types) == TREE_VEC)
8769 len = TREE_VEC_LENGTH (expanded_types);
8771 /* Zero-length parameter packs are boring. Just substitute
8774 return tsubst (TREE_CHAIN (t), args, complain,
8779 /* All we did was update the type. Make a note of that. */
8780 type = expanded_types;
8781 expanded_types = NULL_TREE;
8785 /* Loop through all of the parameter's we'll build. When T is
8786 a function parameter pack, LEN is the number of expanded
8787 types in EXPANDED_TYPES; otherwise, LEN is 1. */
8789 for (i = 0; i < len; ++i)
8793 if (DECL_TEMPLATE_PARM_P (t))
8794 SET_DECL_TEMPLATE_PARM_P (r);
8797 /* We're on the Ith parameter of the function parameter
8800 /* Get the Ith type. */
8801 type = TREE_VEC_ELT (expanded_types, i);
8804 /* Rename the parameter to include the index. */
8806 make_ith_pack_parameter_name (DECL_NAME (r), i);
8809 /* We're dealing with a normal parameter. */
8810 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8812 type = type_decays_to (type);
8813 TREE_TYPE (r) = type;
8814 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8816 if (DECL_INITIAL (r))
8818 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
8819 DECL_INITIAL (r) = TREE_TYPE (r);
8821 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
8825 DECL_CONTEXT (r) = NULL_TREE;
8827 if (!DECL_TEMPLATE_PARM_P (r))
8828 DECL_ARG_TYPE (r) = type_passed_as (type);
8830 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8831 args, complain, in_decl);
8833 /* Keep track of the first new parameter we
8834 generate. That's what will be returned to the
8839 /* Build a proper chain of parameters when substituting
8840 into a function parameter pack. */
8842 TREE_CHAIN (prev_r) = r;
8846 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
8847 complain, TREE_CHAIN (t));
8849 /* FIRST_R contains the start of the chain we've built. */
8859 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8860 if (type == error_mark_node)
8861 return error_mark_node;
8862 TREE_TYPE (r) = type;
8863 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8865 /* DECL_INITIAL gives the number of bits in a bit-field. */
8867 = tsubst_expr (DECL_INITIAL (t), args,
8869 /*integral_constant_expression_p=*/true);
8870 /* We don't have to set DECL_CONTEXT here; it is set by
8871 finish_member_declaration. */
8872 TREE_CHAIN (r) = NULL_TREE;
8873 if (VOID_TYPE_P (type))
8874 error ("instantiation of %q+D as type %qT", r, type);
8876 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8877 args, complain, in_decl);
8882 /* We reach here only for member using decls. */
8883 if (DECL_DEPENDENT_P (t))
8885 r = do_class_using_decl
8886 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
8887 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
8889 r = error_mark_node;
8892 TREE_PROTECTED (r) = TREE_PROTECTED (t);
8893 TREE_PRIVATE (r) = TREE_PRIVATE (t);
8899 TREE_CHAIN (r) = NULL_TREE;
8906 tree argvec = NULL_TREE;
8907 tree gen_tmpl = NULL_TREE;
8909 tree tmpl = NULL_TREE;
8911 tree type = NULL_TREE;
8914 if (TREE_CODE (t) == TYPE_DECL
8915 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
8917 /* If this is the canonical decl, we don't have to
8918 mess with instantiations, and often we can't (for
8919 typename, template type parms and such). Note that
8920 TYPE_NAME is not correct for the above test if
8921 we've copied the type for a typedef. */
8922 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8923 if (type == error_mark_node)
8924 return error_mark_node;
8925 r = TYPE_NAME (type);
8929 /* Check to see if we already have the specialization we
8932 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
8934 /* T is a static data member or namespace-scope entity.
8935 We have to substitute into namespace-scope variables
8936 (even though such entities are never templates) because
8939 template <class T> void f() { extern T t; }
8941 where the entity referenced is not known until
8942 instantiation time. */
8944 ctx = DECL_CONTEXT (t);
8945 if (DECL_CLASS_SCOPE_P (t))
8947 ctx = tsubst_aggr_type (ctx, args,
8949 in_decl, /*entering_scope=*/1);
8950 /* If CTX is unchanged, then T is in fact the
8951 specialization we want. That situation occurs when
8952 referencing a static data member within in its own
8953 class. We can use pointer equality, rather than
8954 same_type_p, because DECL_CONTEXT is always
8956 if (ctx == DECL_CONTEXT (t))
8962 tmpl = DECL_TI_TEMPLATE (t);
8963 gen_tmpl = most_general_template (tmpl);
8964 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
8965 hash = hash_tmpl_and_args (gen_tmpl, argvec);
8966 spec = retrieve_specialization (gen_tmpl, argvec, hash);
8971 /* A local variable. */
8973 /* Subsequent calls to pushdecl will fill this in. */
8975 spec = retrieve_local_specialization (t);
8977 /* If we already have the specialization we need, there is
8978 nothing more to do. */
8985 /* Create a new node for the specialization we need. */
8987 if (type == NULL_TREE)
8988 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8989 if (TREE_CODE (r) == VAR_DECL)
8991 /* Even if the original location is out of scope, the
8992 newly substituted one is not. */
8993 DECL_DEAD_FOR_LOCAL (r) = 0;
8994 DECL_INITIALIZED_P (r) = 0;
8995 DECL_TEMPLATE_INSTANTIATED (r) = 0;
8996 if (type == error_mark_node)
8997 return error_mark_node;
8998 if (TREE_CODE (type) == FUNCTION_TYPE)
9000 /* It may seem that this case cannot occur, since:
9005 declares a function, not a variable. However:
9008 template <typename T> void g() { T t; }
9009 template void g<f>();
9011 is an attempt to declare a variable with function
9013 error ("variable %qD has function type",
9014 /* R is not yet sufficiently initialized, so we
9015 just use its name. */
9017 return error_mark_node;
9019 type = complete_type (type);
9020 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
9021 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
9022 type = check_var_type (DECL_NAME (r), type);
9024 if (DECL_HAS_VALUE_EXPR_P (t))
9026 tree ve = DECL_VALUE_EXPR (t);
9027 ve = tsubst_expr (ve, args, complain, in_decl,
9028 /*constant_expression_p=*/false);
9029 SET_DECL_VALUE_EXPR (r, ve);
9032 else if (DECL_SELF_REFERENCE_P (t))
9033 SET_DECL_SELF_REFERENCE_P (r);
9034 TREE_TYPE (r) = type;
9035 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9036 DECL_CONTEXT (r) = ctx;
9037 /* Clear out the mangled name and RTL for the instantiation. */
9038 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9039 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9040 SET_DECL_RTL (r, NULL_RTX);
9041 /* The initializer must not be expanded until it is required;
9043 DECL_INITIAL (r) = NULL_TREE;
9044 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9045 SET_DECL_RTL (r, NULL_RTX);
9046 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
9047 if (TREE_CODE (r) == VAR_DECL)
9049 /* Possibly limit visibility based on template args. */
9050 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9051 if (DECL_VISIBILITY_SPECIFIED (t))
9053 DECL_VISIBILITY_SPECIFIED (r) = 0;
9055 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9057 determine_visibility (r);
9059 /* Preserve a typedef that names a type. */
9060 else if (TREE_CODE (r) == TYPE_DECL
9061 && DECL_ORIGINAL_TYPE (t)
9062 && type != error_mark_node)
9064 DECL_ORIGINAL_TYPE (r) = tsubst (DECL_ORIGINAL_TYPE (t),
9065 args, complain, in_decl);
9066 TREE_TYPE (r) = type = build_variant_type_copy (type);
9067 TYPE_NAME (type) = r;
9072 /* A static data member declaration is always marked
9073 external when it is declared in-class, even if an
9074 initializer is present. We mimic the non-template
9076 DECL_EXTERNAL (r) = 1;
9078 register_specialization (r, gen_tmpl, argvec, false, hash);
9079 DECL_TEMPLATE_INFO (r) = tree_cons (tmpl, argvec, NULL_TREE);
9080 SET_DECL_IMPLICIT_INSTANTIATION (r);
9083 register_local_specialization (r, t);
9085 TREE_CHAIN (r) = NULL_TREE;
9087 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
9088 (int) ATTR_FLAG_TYPE_IN_PLACE,
9089 args, complain, in_decl);
9098 /* Restore the file and line information. */
9099 input_location = saved_loc;
9104 /* Substitute into the ARG_TYPES of a function type. */
9107 tsubst_arg_types (tree arg_types,
9109 tsubst_flags_t complain,
9112 tree remaining_arg_types;
9113 tree type = NULL_TREE;
9115 tree expanded_args = NULL_TREE;
9118 if (!arg_types || arg_types == void_list_node)
9121 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
9122 args, complain, in_decl);
9123 if (remaining_arg_types == error_mark_node)
9124 return error_mark_node;
9126 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
9128 /* For a pack expansion, perform substitution on the
9129 entire expression. Later on, we'll handle the arguments
9131 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
9132 args, complain, in_decl);
9134 if (TREE_CODE (expanded_args) == TREE_VEC)
9135 /* So that we'll spin through the parameters, one by one. */
9136 i = TREE_VEC_LENGTH (expanded_args);
9139 /* We only partially substituted into the parameter
9140 pack. Our type is TYPE_PACK_EXPANSION. */
9141 type = expanded_args;
9142 expanded_args = NULL_TREE;
9150 type = TREE_VEC_ELT (expanded_args, i);
9152 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
9154 if (type == error_mark_node)
9155 return error_mark_node;
9156 if (VOID_TYPE_P (type))
9158 if (complain & tf_error)
9160 error ("invalid parameter type %qT", type);
9162 error ("in declaration %q+D", in_decl);
9164 return error_mark_node;
9167 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9168 top-level qualifiers as required. */
9169 type = TYPE_MAIN_VARIANT (type_decays_to (type));
9171 /* We do not substitute into default arguments here. The standard
9172 mandates that they be instantiated only when needed, which is
9173 done in build_over_call. */
9174 default_arg = TREE_PURPOSE (arg_types);
9176 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
9178 /* We've instantiated a template before its default arguments
9179 have been parsed. This can happen for a nested template
9180 class, and is not an error unless we require the default
9181 argument in a call of this function. */
9182 remaining_arg_types =
9183 tree_cons (default_arg, type, remaining_arg_types);
9184 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
9185 remaining_arg_types);
9188 remaining_arg_types =
9189 hash_tree_cons (default_arg, type, remaining_arg_types);
9192 return remaining_arg_types;
9195 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9196 *not* handle the exception-specification for FNTYPE, because the
9197 initial substitution of explicitly provided template parameters
9198 during argument deduction forbids substitution into the
9199 exception-specification:
9203 All references in the function type of the function template to the
9204 corresponding template parameters are replaced by the specified tem-
9205 plate argument values. If a substitution in a template parameter or
9206 in the function type of the function template results in an invalid
9207 type, type deduction fails. [Note: The equivalent substitution in
9208 exception specifications is done only when the function is instanti-
9209 ated, at which point a program is ill-formed if the substitution
9210 results in an invalid type.] */
9213 tsubst_function_type (tree t,
9215 tsubst_flags_t complain,
9222 /* The TYPE_CONTEXT is not used for function/method types. */
9223 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
9225 /* Substitute the return type. */
9226 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9227 if (return_type == error_mark_node)
9228 return error_mark_node;
9229 /* The standard does not presently indicate that creation of a
9230 function type with an invalid return type is a deduction failure.
9231 However, that is clearly analogous to creating an array of "void"
9232 or a reference to a reference. This is core issue #486. */
9233 if (TREE_CODE (return_type) == ARRAY_TYPE
9234 || TREE_CODE (return_type) == FUNCTION_TYPE)
9236 if (complain & tf_error)
9238 if (TREE_CODE (return_type) == ARRAY_TYPE)
9239 error ("function returning an array");
9241 error ("function returning a function");
9243 return error_mark_node;
9246 /* Substitute the argument types. */
9247 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
9249 if (arg_types == error_mark_node)
9250 return error_mark_node;
9252 /* Construct a new type node and return it. */
9253 if (TREE_CODE (t) == FUNCTION_TYPE)
9254 fntype = build_function_type (return_type, arg_types);
9257 tree r = TREE_TYPE (TREE_VALUE (arg_types));
9258 if (! MAYBE_CLASS_TYPE_P (r))
9262 Type deduction may fail for any of the following
9265 -- Attempting to create "pointer to member of T" when T
9266 is not a class type. */
9267 if (complain & tf_error)
9268 error ("creating pointer to member function of non-class type %qT",
9270 return error_mark_node;
9273 fntype = build_method_type_directly (r, return_type,
9274 TREE_CHAIN (arg_types));
9276 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
9277 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
9282 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9283 ARGS into that specification, and return the substituted
9284 specification. If there is no specification, return NULL_TREE. */
9287 tsubst_exception_specification (tree fntype,
9289 tsubst_flags_t complain,
9295 specs = TYPE_RAISES_EXCEPTIONS (fntype);
9296 new_specs = NULL_TREE;
9299 if (! TREE_VALUE (specs))
9306 tree expanded_specs = NULL_TREE;
9308 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
9310 /* Expand the pack expansion type. */
9311 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
9315 if (expanded_specs == error_mark_node)
9316 return error_mark_node;
9317 else if (TREE_CODE (expanded_specs) == TREE_VEC)
9318 len = TREE_VEC_LENGTH (expanded_specs);
9321 /* We're substituting into a member template, so
9322 we got a TYPE_PACK_EXPANSION back. Add that
9323 expansion and move on. */
9324 gcc_assert (TREE_CODE (expanded_specs)
9325 == TYPE_PACK_EXPANSION);
9326 new_specs = add_exception_specifier (new_specs,
9329 specs = TREE_CHAIN (specs);
9334 for (i = 0; i < len; ++i)
9337 spec = TREE_VEC_ELT (expanded_specs, i);
9339 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
9340 if (spec == error_mark_node)
9342 new_specs = add_exception_specifier (new_specs, spec,
9346 specs = TREE_CHAIN (specs);
9352 /* Take the tree structure T and replace template parameters used
9353 therein with the argument vector ARGS. IN_DECL is an associated
9354 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9355 Issue error and warning messages under control of COMPLAIN. Note
9356 that we must be relatively non-tolerant of extensions here, in
9357 order to preserve conformance; if we allow substitutions that
9358 should not be allowed, we may allow argument deductions that should
9359 not succeed, and therefore report ambiguous overload situations
9360 where there are none. In theory, we could allow the substitution,
9361 but indicate that it should have failed, and allow our caller to
9362 make sure that the right thing happens, but we don't try to do this
9365 This function is used for dealing with types, decls and the like;
9366 for expressions, use tsubst_expr or tsubst_copy. */
9369 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9373 if (t == NULL_TREE || t == error_mark_node
9374 || t == integer_type_node
9375 || t == void_type_node
9376 || t == char_type_node
9377 || t == unknown_type_node
9378 || TREE_CODE (t) == NAMESPACE_DECL)
9382 return tsubst_decl (t, args, complain);
9384 if (args == NULL_TREE)
9387 if (TREE_CODE (t) == IDENTIFIER_NODE)
9388 type = IDENTIFIER_TYPE_VALUE (t);
9390 type = TREE_TYPE (t);
9392 gcc_assert (type != unknown_type_node);
9394 /* Reuse typedefs. We need to do this to handle dependent attributes,
9395 such as attribute aligned. */
9398 && TYPE_NAME (t) != TYPE_MAIN_DECL (t))
9400 tree decl = TYPE_NAME (t);
9402 if (DECL_CLASS_SCOPE_P (decl)
9403 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
9404 && uses_template_parms (DECL_CONTEXT (decl)))
9406 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
9407 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
9408 r = retrieve_specialization (tmpl, gen_args, 0);
9410 else if (DECL_FUNCTION_SCOPE_P (decl)
9411 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
9412 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
9413 r = retrieve_local_specialization (decl);
9415 /* The typedef is from a non-template context. */
9421 r = cp_build_qualified_type_real
9422 (r, cp_type_quals (t) | cp_type_quals (r),
9423 complain | tf_ignore_bad_quals);
9426 /* Else we must be instantiating the typedef, so fall through. */
9430 && TREE_CODE (t) != TYPENAME_TYPE
9431 && TREE_CODE (t) != IDENTIFIER_NODE
9432 && TREE_CODE (t) != FUNCTION_TYPE
9433 && TREE_CODE (t) != METHOD_TYPE)
9434 type = tsubst (type, args, complain, in_decl);
9435 if (type == error_mark_node)
9436 return error_mark_node;
9438 switch (TREE_CODE (t))
9443 return tsubst_aggr_type (t, args, complain, in_decl,
9444 /*entering_scope=*/0);
9447 case IDENTIFIER_NODE:
9459 if (t == integer_type_node)
9462 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
9463 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
9467 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
9469 max = tsubst_expr (omax, args, complain, in_decl,
9470 /*integral_constant_expression_p=*/false);
9472 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
9474 if (TREE_CODE (max) == NOP_EXPR
9475 && TREE_SIDE_EFFECTS (omax)
9476 && !TREE_TYPE (max))
9477 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
9479 max = fold_decl_constant_value (max);
9481 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
9482 with TREE_SIDE_EFFECTS that indicates this is not an integral
9483 constant expression. */
9484 if (processing_template_decl
9485 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
9487 gcc_assert (TREE_CODE (max) == NOP_EXPR);
9488 TREE_SIDE_EFFECTS (max) = 1;
9491 if (TREE_CODE (max) != INTEGER_CST
9492 && !at_function_scope_p ()
9493 && !TREE_SIDE_EFFECTS (max)
9494 && !value_dependent_expression_p (max))
9496 if (complain & tf_error)
9497 error ("array bound is not an integer constant");
9498 return error_mark_node;
9503 Type deduction may fail for any of the following
9506 Attempting to create an array with a size that is
9507 zero or negative. */
9508 if (integer_zerop (max) && !(complain & tf_error))
9509 /* We must fail if performing argument deduction (as
9510 indicated by the state of complain), so that
9511 another substitution can be found. */
9512 return error_mark_node;
9513 else if (TREE_CODE (max) == INTEGER_CST
9514 && INT_CST_LT (max, integer_zero_node))
9516 if (complain & tf_error)
9517 error ("creating array with negative size (%qE)", max);
9519 return error_mark_node;
9522 return compute_array_index_type (NULL_TREE, max);
9525 case TEMPLATE_TYPE_PARM:
9526 case TEMPLATE_TEMPLATE_PARM:
9527 case BOUND_TEMPLATE_TEMPLATE_PARM:
9528 case TEMPLATE_PARM_INDEX:
9533 tree arg = NULL_TREE;
9537 gcc_assert (TREE_VEC_LENGTH (args) > 0);
9538 template_parm_level_and_index (t, &level, &idx);
9540 levels = TMPL_ARGS_DEPTH (args);
9541 if (level <= levels)
9543 arg = TMPL_ARG (args, level, idx);
9545 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
9546 /* See through ARGUMENT_PACK_SELECT arguments. */
9547 arg = ARGUMENT_PACK_SELECT_ARG (arg);
9550 if (arg == error_mark_node)
9551 return error_mark_node;
9552 else if (arg != NULL_TREE)
9554 if (ARGUMENT_PACK_P (arg))
9555 /* If ARG is an argument pack, we don't actually want to
9556 perform a substitution here, because substitutions
9557 for argument packs are only done
9558 element-by-element. We can get to this point when
9559 substituting the type of a non-type template
9560 parameter pack, when that type actually contains
9561 template parameter packs from an outer template, e.g.,
9563 template<typename... Types> struct A {
9564 template<Types... Values> struct B { };
9568 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
9571 gcc_assert (TYPE_P (arg));
9573 /* cv-quals from the template are discarded when
9574 substituting in a function or reference type. */
9575 if (TREE_CODE (arg) == FUNCTION_TYPE
9576 || TREE_CODE (arg) == METHOD_TYPE
9577 || TREE_CODE (arg) == REFERENCE_TYPE)
9578 quals = cp_type_quals (arg);
9580 quals = cp_type_quals (arg) | cp_type_quals (t);
9582 return cp_build_qualified_type_real
9583 (arg, quals, complain | tf_ignore_bad_quals);
9585 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9587 /* We are processing a type constructed from a
9588 template template parameter. */
9589 tree argvec = tsubst (TYPE_TI_ARGS (t),
9590 args, complain, in_decl);
9591 if (argvec == error_mark_node)
9592 return error_mark_node;
9594 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
9595 are resolving nested-types in the signature of a
9596 member function templates. Otherwise ARG is a
9597 TEMPLATE_DECL and is the real template to be
9599 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
9600 arg = TYPE_NAME (arg);
9602 r = lookup_template_class (arg,
9605 /*entering_scope=*/0,
9607 return cp_build_qualified_type_real
9608 (r, TYPE_QUALS (t), complain);
9611 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
9616 /* This can happen during the attempted tsubst'ing in
9617 unify. This means that we don't yet have any information
9618 about the template parameter in question. */
9621 /* If we get here, we must have been looking at a parm for a
9622 more deeply nested template. Make a new version of this
9623 template parameter, but with a lower level. */
9624 switch (TREE_CODE (t))
9626 case TEMPLATE_TYPE_PARM:
9627 case TEMPLATE_TEMPLATE_PARM:
9628 case BOUND_TEMPLATE_TEMPLATE_PARM:
9629 if (cp_type_quals (t))
9631 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
9632 r = cp_build_qualified_type_real
9633 (r, cp_type_quals (t),
9634 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
9635 ? tf_ignore_bad_quals : 0));
9640 TEMPLATE_TYPE_PARM_INDEX (r)
9641 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
9642 r, levels, args, complain);
9643 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
9644 TYPE_MAIN_VARIANT (r) = r;
9645 TYPE_POINTER_TO (r) = NULL_TREE;
9646 TYPE_REFERENCE_TO (r) = NULL_TREE;
9648 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
9649 /* We have reduced the level of the template
9650 template parameter, but not the levels of its
9651 template parameters, so canonical_type_parameter
9652 will not be able to find the canonical template
9653 template parameter for this level. Thus, we
9654 require structural equality checking to compare
9655 TEMPLATE_TEMPLATE_PARMs. */
9656 SET_TYPE_STRUCTURAL_EQUALITY (r);
9657 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
9658 SET_TYPE_STRUCTURAL_EQUALITY (r);
9660 TYPE_CANONICAL (r) = canonical_type_parameter (r);
9662 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9664 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
9666 if (argvec == error_mark_node)
9667 return error_mark_node;
9669 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
9670 = tree_cons (TYPE_TI_TEMPLATE (t), argvec, NULL_TREE);
9675 case TEMPLATE_PARM_INDEX:
9676 r = reduce_template_parm_level (t, type, levels, args, complain);
9688 tree purpose, value, chain;
9690 if (t == void_list_node)
9693 purpose = TREE_PURPOSE (t);
9696 purpose = tsubst (purpose, args, complain, in_decl);
9697 if (purpose == error_mark_node)
9698 return error_mark_node;
9700 value = TREE_VALUE (t);
9703 value = tsubst (value, args, complain, in_decl);
9704 if (value == error_mark_node)
9705 return error_mark_node;
9707 chain = TREE_CHAIN (t);
9708 if (chain && chain != void_type_node)
9710 chain = tsubst (chain, args, complain, in_decl);
9711 if (chain == error_mark_node)
9712 return error_mark_node;
9714 if (purpose == TREE_PURPOSE (t)
9715 && value == TREE_VALUE (t)
9716 && chain == TREE_CHAIN (t))
9718 return hash_tree_cons (purpose, value, chain);
9722 /* We should never be tsubsting a binfo. */
9726 /* A vector of template arguments. */
9728 return tsubst_template_args (t, args, complain, in_decl);
9731 case REFERENCE_TYPE:
9733 enum tree_code code;
9735 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
9738 code = TREE_CODE (t);
9743 Type deduction may fail for any of the following
9746 -- Attempting to create a pointer to reference type.
9747 -- Attempting to create a reference to a reference type or
9748 a reference to void.
9750 Core issue 106 says that creating a reference to a reference
9751 during instantiation is no longer a cause for failure. We
9752 only enforce this check in strict C++98 mode. */
9753 if ((TREE_CODE (type) == REFERENCE_TYPE
9754 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
9755 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
9757 static location_t last_loc;
9759 /* We keep track of the last time we issued this error
9760 message to avoid spewing a ton of messages during a
9761 single bad template instantiation. */
9762 if (complain & tf_error
9763 && last_loc != input_location)
9765 if (TREE_CODE (type) == VOID_TYPE)
9766 error ("forming reference to void");
9768 error ("forming %s to reference type %qT",
9769 (code == POINTER_TYPE) ? "pointer" : "reference",
9771 last_loc = input_location;
9774 return error_mark_node;
9776 else if (code == POINTER_TYPE)
9778 r = build_pointer_type (type);
9779 if (TREE_CODE (type) == METHOD_TYPE)
9780 r = build_ptrmemfunc_type (r);
9782 else if (TREE_CODE (type) == REFERENCE_TYPE)
9783 /* In C++0x, during template argument substitution, when there is an
9784 attempt to create a reference to a reference type, reference
9785 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
9787 "If a template-argument for a template-parameter T names a type
9788 that is a reference to a type A, an attempt to create the type
9789 'lvalue reference to cv T' creates the type 'lvalue reference to
9790 A,' while an attempt to create the type type rvalue reference to
9791 cv T' creates the type T"
9793 r = cp_build_reference_type
9795 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
9797 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
9798 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
9800 if (r != error_mark_node)
9801 /* Will this ever be needed for TYPE_..._TO values? */
9808 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
9809 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
9813 Type deduction may fail for any of the following
9816 -- Attempting to create "pointer to member of T" when T
9817 is not a class type. */
9818 if (complain & tf_error)
9819 error ("creating pointer to member of non-class type %qT", r);
9820 return error_mark_node;
9822 if (TREE_CODE (type) == REFERENCE_TYPE)
9824 if (complain & tf_error)
9825 error ("creating pointer to member reference type %qT", type);
9826 return error_mark_node;
9828 if (TREE_CODE (type) == VOID_TYPE)
9830 if (complain & tf_error)
9831 error ("creating pointer to member of type void");
9832 return error_mark_node;
9834 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
9835 if (TREE_CODE (type) == FUNCTION_TYPE)
9837 /* The type of the implicit object parameter gets its
9838 cv-qualifiers from the FUNCTION_TYPE. */
9840 tree this_type = cp_build_qualified_type (TYPE_MAIN_VARIANT (r),
9841 cp_type_quals (type));
9843 method_type = build_method_type_directly (this_type,
9845 TYPE_ARG_TYPES (type));
9846 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
9847 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
9851 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
9860 fntype = tsubst_function_type (t, args, complain, in_decl);
9861 if (fntype == error_mark_node)
9862 return error_mark_node;
9864 /* Substitute the exception specification. */
9865 specs = tsubst_exception_specification (t, args, complain,
9867 if (specs == error_mark_node)
9868 return error_mark_node;
9870 fntype = build_exception_variant (fntype, specs);
9875 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
9876 if (domain == error_mark_node)
9877 return error_mark_node;
9879 /* As an optimization, we avoid regenerating the array type if
9880 it will obviously be the same as T. */
9881 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
9884 /* These checks should match the ones in grokdeclarator.
9888 The deduction may fail for any of the following reasons:
9890 -- Attempting to create an array with an element type that
9891 is void, a function type, or a reference type, or [DR337]
9892 an abstract class type. */
9893 if (TREE_CODE (type) == VOID_TYPE
9894 || TREE_CODE (type) == FUNCTION_TYPE
9895 || TREE_CODE (type) == REFERENCE_TYPE)
9897 if (complain & tf_error)
9898 error ("creating array of %qT", type);
9899 return error_mark_node;
9901 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
9903 if (complain & tf_error)
9904 error ("creating array of %qT, which is an abstract class type",
9906 return error_mark_node;
9909 r = build_cplus_array_type (type, domain);
9911 if (TYPE_USER_ALIGN (t))
9913 TYPE_ALIGN (r) = TYPE_ALIGN (t);
9914 TYPE_USER_ALIGN (r) = 1;
9923 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9924 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
9926 if (e1 == error_mark_node || e2 == error_mark_node)
9927 return error_mark_node;
9929 return fold_build2_loc (input_location,
9930 TREE_CODE (t), TREE_TYPE (t), e1, e2);
9936 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9937 if (e == error_mark_node)
9938 return error_mark_node;
9940 return fold_build1_loc (input_location, TREE_CODE (t), TREE_TYPE (t), e);
9945 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
9946 in_decl, /*entering_scope=*/1);
9947 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
9950 if (ctx == error_mark_node || f == error_mark_node)
9951 return error_mark_node;
9953 if (!MAYBE_CLASS_TYPE_P (ctx))
9955 if (complain & tf_error)
9956 error ("%qT is not a class, struct, or union type", ctx);
9957 return error_mark_node;
9959 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
9961 /* Normally, make_typename_type does not require that the CTX
9962 have complete type in order to allow things like:
9964 template <class T> struct S { typename S<T>::X Y; };
9966 But, such constructs have already been resolved by this
9967 point, so here CTX really should have complete type, unless
9968 it's a partial instantiation. */
9969 if (!(complain & tf_no_class_instantiations))
9970 ctx = complete_type (ctx);
9971 if (!COMPLETE_TYPE_P (ctx))
9973 if (complain & tf_error)
9974 cxx_incomplete_type_error (NULL_TREE, ctx);
9975 return error_mark_node;
9979 f = make_typename_type (ctx, f, typename_type,
9980 (complain & tf_error) | tf_keep_type_decl);
9981 if (f == error_mark_node)
9983 if (TREE_CODE (f) == TYPE_DECL)
9985 complain |= tf_ignore_bad_quals;
9989 if (TREE_CODE (f) != TYPENAME_TYPE)
9991 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
9992 error ("%qT resolves to %qT, which is not an enumeration type",
9994 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
9995 error ("%qT resolves to %qT, which is is not a class type",
9999 return cp_build_qualified_type_real
10000 (f, cp_type_quals (f) | cp_type_quals (t), complain);
10003 case UNBOUND_CLASS_TEMPLATE:
10005 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10006 in_decl, /*entering_scope=*/1);
10007 tree name = TYPE_IDENTIFIER (t);
10008 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
10010 if (ctx == error_mark_node || name == error_mark_node)
10011 return error_mark_node;
10014 parm_list = tsubst_template_parms (parm_list, args, complain);
10015 return make_unbound_class_template (ctx, name, parm_list, complain);
10021 gcc_unreachable ();
10025 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10026 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl,
10027 /*integral_constant_expression_p=*/false);
10028 if (e1 == error_mark_node || e2 == error_mark_node)
10029 return error_mark_node;
10031 return build_nt (ARRAY_REF, e1, e2, NULL_TREE, NULL_TREE);
10036 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10037 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10038 if (e1 == error_mark_node || e2 == error_mark_node)
10039 return error_mark_node;
10041 return build_qualified_name (/*type=*/NULL_TREE,
10042 e1, e2, QUALIFIED_NAME_IS_TEMPLATE (t));
10049 type = finish_typeof (tsubst_expr
10050 (TYPEOF_TYPE_EXPR (t), args,
10052 /*integral_constant_expression_p=*/false));
10053 return cp_build_qualified_type_real (type,
10055 | cp_type_quals (type),
10059 case DECLTYPE_TYPE:
10063 ++cp_unevaluated_operand;
10064 ++c_inhibit_evaluation_warnings;
10066 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
10068 /*integral_constant_expression_p=*/false);
10070 --cp_unevaluated_operand;
10071 --c_inhibit_evaluation_warnings;
10074 finish_decltype_type (type,
10075 DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
10076 return cp_build_qualified_type_real (type,
10078 | cp_type_quals (type),
10082 case TYPE_ARGUMENT_PACK:
10083 case NONTYPE_ARGUMENT_PACK:
10085 tree r = make_node (TREE_CODE (t));
10087 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
10091 SET_ARGUMENT_PACK_ARGS (r, packed_out);
10093 /* For template nontype argument packs, also substitute into
10095 if (TREE_CODE (t) == NONTYPE_ARGUMENT_PACK)
10096 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
10103 sorry ("use of %qs in template",
10104 tree_code_name [(int) TREE_CODE (t)]);
10105 return error_mark_node;
10109 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10110 type of the expression on the left-hand side of the "." or "->"
10114 tsubst_baselink (tree baselink, tree object_type,
10115 tree args, tsubst_flags_t complain, tree in_decl)
10118 tree qualifying_scope;
10121 tree template_args = 0;
10122 bool template_id_p = false;
10124 /* A baselink indicates a function from a base class. Both the
10125 BASELINK_ACCESS_BINFO and the base class referenced may
10126 indicate bases of the template class, rather than the
10127 instantiated class. In addition, lookups that were not
10128 ambiguous before may be ambiguous now. Therefore, we perform
10129 the lookup again. */
10130 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
10131 qualifying_scope = tsubst (qualifying_scope, args,
10132 complain, in_decl);
10133 fns = BASELINK_FUNCTIONS (baselink);
10134 optype = BASELINK_OPTYPE (baselink);
10135 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
10137 template_id_p = true;
10138 template_args = TREE_OPERAND (fns, 1);
10139 fns = TREE_OPERAND (fns, 0);
10141 template_args = tsubst_template_args (template_args, args,
10142 complain, in_decl);
10144 name = DECL_NAME (get_first_fn (fns));
10145 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
10147 /* If lookup found a single function, mark it as used at this
10148 point. (If it lookup found multiple functions the one selected
10149 later by overload resolution will be marked as used at that
10151 if (BASELINK_P (baselink))
10152 fns = BASELINK_FUNCTIONS (baselink);
10153 if (!template_id_p && !really_overloaded_fn (fns))
10154 mark_used (OVL_CURRENT (fns));
10156 /* Add back the template arguments, if present. */
10157 if (BASELINK_P (baselink) && template_id_p)
10158 BASELINK_FUNCTIONS (baselink)
10159 = build_nt (TEMPLATE_ID_EXPR,
10160 BASELINK_FUNCTIONS (baselink),
10162 /* Update the conversion operator type. */
10163 BASELINK_OPTYPE (baselink)
10164 = tsubst (optype, args, complain, in_decl);
10167 object_type = current_class_type;
10168 return adjust_result_of_qualified_name_lookup (baselink,
10173 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10174 true if the qualified-id will be a postfix-expression in-and-of
10175 itself; false if more of the postfix-expression follows the
10176 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10180 tsubst_qualified_id (tree qualified_id, tree args,
10181 tsubst_flags_t complain, tree in_decl,
10182 bool done, bool address_p)
10188 tree template_args;
10190 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
10192 /* Figure out what name to look up. */
10193 name = TREE_OPERAND (qualified_id, 1);
10194 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
10196 is_template = true;
10197 template_args = TREE_OPERAND (name, 1);
10199 template_args = tsubst_template_args (template_args, args,
10200 complain, in_decl);
10201 name = TREE_OPERAND (name, 0);
10205 is_template = false;
10206 template_args = NULL_TREE;
10209 /* Substitute into the qualifying scope. When there are no ARGS, we
10210 are just trying to simplify a non-dependent expression. In that
10211 case the qualifying scope may be dependent, and, in any case,
10212 substituting will not help. */
10213 scope = TREE_OPERAND (qualified_id, 0);
10216 scope = tsubst (scope, args, complain, in_decl);
10217 expr = tsubst_copy (name, args, complain, in_decl);
10222 if (dependent_type_p (scope))
10224 tree type = NULL_TREE;
10225 if (DECL_P (expr) && !dependent_scope_p (scope))
10226 type = TREE_TYPE (expr);
10227 return build_qualified_name (type, scope, expr,
10228 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
10231 if (!BASELINK_P (name) && !DECL_P (expr))
10233 if (TREE_CODE (expr) == BIT_NOT_EXPR)
10235 /* A BIT_NOT_EXPR is used to represent a destructor. */
10236 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
10238 error ("qualifying type %qT does not match destructor name ~%qT",
10239 scope, TREE_OPERAND (expr, 0));
10240 expr = error_mark_node;
10243 expr = lookup_qualified_name (scope, complete_dtor_identifier,
10244 /*is_type_p=*/0, false);
10247 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
10248 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
10249 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
10251 if (complain & tf_error)
10253 error ("dependent-name %qE is parsed as a non-type, but "
10254 "instantiation yields a type", qualified_id);
10255 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
10257 return error_mark_node;
10263 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
10265 /* Remember that there was a reference to this entity. */
10269 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
10271 if (complain & tf_error)
10272 qualified_name_lookup_error (scope,
10273 TREE_OPERAND (qualified_id, 1),
10274 expr, input_location);
10275 return error_mark_node;
10279 expr = lookup_template_function (expr, template_args);
10281 if (expr == error_mark_node && complain & tf_error)
10282 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
10283 expr, input_location);
10284 else if (TYPE_P (scope))
10286 expr = (adjust_result_of_qualified_name_lookup
10287 (expr, scope, current_class_type));
10288 expr = (finish_qualified_id_expr
10289 (scope, expr, done, address_p,
10290 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
10291 /*template_arg_p=*/false));
10294 /* Expressions do not generally have reference type. */
10295 if (TREE_CODE (expr) != SCOPE_REF
10296 /* However, if we're about to form a pointer-to-member, we just
10297 want the referenced member referenced. */
10298 && TREE_CODE (expr) != OFFSET_REF)
10299 expr = convert_from_reference (expr);
10304 /* Like tsubst, but deals with expressions. This function just replaces
10305 template parms; to finish processing the resultant expression, use
10309 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10311 enum tree_code code;
10314 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
10317 code = TREE_CODE (t);
10322 r = retrieve_local_specialization (t);
10327 /* This can happen for a parameter name used later in a function
10328 declaration (such as in a late-specified return type). Just
10329 make a dummy decl, since it's only used for its type. */
10330 gcc_assert (cp_unevaluated_operand != 0);
10331 /* We copy T because want to tsubst the PARM_DECL only,
10332 not the following PARM_DECLs that are chained to T. */
10334 r = tsubst_decl (c, args, complain);
10335 /* Give it the template pattern as its context; its true context
10336 hasn't been instantiated yet and this is good enough for
10338 DECL_CONTEXT (r) = DECL_CONTEXT (t);
10341 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
10342 r = ARGUMENT_PACK_SELECT_ARG (r);
10351 if (DECL_TEMPLATE_PARM_P (t))
10352 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
10353 /* There is no need to substitute into namespace-scope
10355 if (DECL_NAMESPACE_SCOPE_P (t))
10357 /* If ARGS is NULL, then T is known to be non-dependent. */
10358 if (args == NULL_TREE)
10359 return integral_constant_value (t);
10361 /* Unfortunately, we cannot just call lookup_name here.
10364 template <int I> int f() {
10366 struct S { void g() { E e = a; } };
10369 When we instantiate f<7>::S::g(), say, lookup_name is not
10370 clever enough to find f<7>::a. */
10372 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
10373 /*entering_scope=*/0);
10375 for (v = TYPE_VALUES (enum_type);
10377 v = TREE_CHAIN (v))
10378 if (TREE_PURPOSE (v) == DECL_NAME (t))
10379 return TREE_VALUE (v);
10381 /* We didn't find the name. That should never happen; if
10382 name-lookup found it during preliminary parsing, we
10383 should find it again here during instantiation. */
10384 gcc_unreachable ();
10389 if (DECL_CONTEXT (t))
10393 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
10394 /*entering_scope=*/1);
10395 if (ctx != DECL_CONTEXT (t))
10397 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
10400 if (complain & tf_error)
10401 error ("using invalid field %qD", t);
10402 return error_mark_node;
10411 case FUNCTION_DECL:
10412 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
10413 || local_variable_p (t))
10414 t = tsubst (t, args, complain, in_decl);
10419 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
10421 case TEMPLATE_DECL:
10422 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10423 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
10424 args, complain, in_decl);
10425 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
10426 return tsubst (t, args, complain, in_decl);
10427 else if (DECL_CLASS_SCOPE_P (t)
10428 && uses_template_parms (DECL_CONTEXT (t)))
10430 /* Template template argument like the following example need
10433 template <template <class> class TT> struct C {};
10434 template <class T> struct D {
10435 template <class U> struct E {};
10440 We are processing the template argument `E' in #1 for
10441 the template instantiation #2. Originally, `E' is a
10442 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10443 have to substitute this with one having context `D<int>'. */
10445 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
10446 return lookup_field (context, DECL_NAME(t), 0, false);
10449 /* Ordinary template template argument. */
10453 case REINTERPRET_CAST_EXPR:
10454 case CONST_CAST_EXPR:
10455 case STATIC_CAST_EXPR:
10456 case DYNAMIC_CAST_EXPR:
10459 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10460 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10463 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
10465 /* We only want to compute the number of arguments. */
10466 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
10467 complain, in_decl);
10470 if (TREE_CODE (expanded) == TREE_VEC)
10471 len = TREE_VEC_LENGTH (expanded);
10473 if (expanded == error_mark_node)
10474 return error_mark_node;
10475 else if (PACK_EXPANSION_P (expanded)
10476 || (TREE_CODE (expanded) == TREE_VEC
10478 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
10480 if (TREE_CODE (expanded) == TREE_VEC)
10481 expanded = TREE_VEC_ELT (expanded, len - 1);
10483 if (TYPE_P (expanded))
10484 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
10485 complain & tf_error);
10487 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
10488 complain & tf_error);
10491 return build_int_cst (size_type_node, len);
10497 case TRUTH_NOT_EXPR:
10500 case UNARY_PLUS_EXPR: /* Unary + */
10505 case REALPART_EXPR:
10506 case IMAGPART_EXPR:
10508 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10509 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10511 case COMPONENT_REF:
10516 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
10517 name = TREE_OPERAND (t, 1);
10518 if (TREE_CODE (name) == BIT_NOT_EXPR)
10520 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10521 complain, in_decl);
10522 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10524 else if (TREE_CODE (name) == SCOPE_REF
10525 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
10527 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
10528 complain, in_decl);
10529 name = TREE_OPERAND (name, 1);
10530 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10531 complain, in_decl);
10532 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10533 name = build_qualified_name (/*type=*/NULL_TREE,
10535 /*template_p=*/false);
10537 else if (TREE_CODE (name) == BASELINK)
10538 name = tsubst_baselink (name,
10539 non_reference (TREE_TYPE (object)),
10543 name = tsubst_copy (name, args, complain, in_decl);
10544 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
10550 case TRUNC_DIV_EXPR:
10551 case CEIL_DIV_EXPR:
10552 case FLOOR_DIV_EXPR:
10553 case ROUND_DIV_EXPR:
10554 case EXACT_DIV_EXPR:
10558 case TRUNC_MOD_EXPR:
10559 case FLOOR_MOD_EXPR:
10560 case TRUTH_ANDIF_EXPR:
10561 case TRUTH_ORIF_EXPR:
10562 case TRUTH_AND_EXPR:
10563 case TRUTH_OR_EXPR:
10576 case COMPOUND_EXPR:
10579 case PREDECREMENT_EXPR:
10580 case PREINCREMENT_EXPR:
10581 case POSTDECREMENT_EXPR:
10582 case POSTINCREMENT_EXPR:
10584 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10585 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10588 return build_qualified_name (/*type=*/NULL_TREE,
10589 tsubst_copy (TREE_OPERAND (t, 0),
10590 args, complain, in_decl),
10591 tsubst_copy (TREE_OPERAND (t, 1),
10592 args, complain, in_decl),
10593 QUALIFIED_NAME_IS_TEMPLATE (t));
10598 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10599 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10600 NULL_TREE, NULL_TREE);
10604 int n = VL_EXP_OPERAND_LENGTH (t);
10605 tree result = build_vl_exp (CALL_EXPR, n);
10607 for (i = 0; i < n; i++)
10608 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
10609 complain, in_decl);
10615 case PSEUDO_DTOR_EXPR:
10618 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10619 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10620 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10621 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
10628 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10629 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10630 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10631 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
10638 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10639 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10640 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
10641 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
10645 case TEMPLATE_ID_EXPR:
10647 /* Substituted template arguments */
10648 tree fn = TREE_OPERAND (t, 0);
10649 tree targs = TREE_OPERAND (t, 1);
10651 fn = tsubst_copy (fn, args, complain, in_decl);
10653 targs = tsubst_template_args (targs, args, complain, in_decl);
10655 return lookup_template_function (fn, targs);
10660 tree purpose, value, chain;
10662 if (t == void_list_node)
10665 purpose = TREE_PURPOSE (t);
10667 purpose = tsubst_copy (purpose, args, complain, in_decl);
10668 value = TREE_VALUE (t);
10670 value = tsubst_copy (value, args, complain, in_decl);
10671 chain = TREE_CHAIN (t);
10672 if (chain && chain != void_type_node)
10673 chain = tsubst_copy (chain, args, complain, in_decl);
10674 if (purpose == TREE_PURPOSE (t)
10675 && value == TREE_VALUE (t)
10676 && chain == TREE_CHAIN (t))
10678 return tree_cons (purpose, value, chain);
10683 case ENUMERAL_TYPE:
10685 case TEMPLATE_TYPE_PARM:
10686 case TEMPLATE_TEMPLATE_PARM:
10687 case BOUND_TEMPLATE_TEMPLATE_PARM:
10688 case TEMPLATE_PARM_INDEX:
10690 case REFERENCE_TYPE:
10692 case FUNCTION_TYPE:
10695 case TYPENAME_TYPE:
10696 case UNBOUND_CLASS_TEMPLATE:
10698 case DECLTYPE_TYPE:
10700 return tsubst (t, args, complain, in_decl);
10702 case IDENTIFIER_NODE:
10703 if (IDENTIFIER_TYPENAME_P (t))
10705 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10706 return mangle_conv_op_name_for_type (new_type);
10712 /* This is handled by tsubst_copy_and_build. */
10713 gcc_unreachable ();
10716 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
10718 tsubst (TREE_TYPE (t), args, complain, in_decl));
10720 case CLEANUP_POINT_EXPR:
10721 /* We shouldn't have built any of these during initial template
10722 generation. Instead, they should be built during instantiation
10723 in response to the saved STMT_IS_FULL_EXPR_P setting. */
10724 gcc_unreachable ();
10727 mark_used (TREE_OPERAND (t, 1));
10730 case EXPR_PACK_EXPANSION:
10731 error ("invalid use of pack expansion expression");
10732 return error_mark_node;
10734 case NONTYPE_ARGUMENT_PACK:
10735 error ("use %<...%> to expand argument pack");
10736 return error_mark_node;
10743 /* Like tsubst_copy, but specifically for OpenMP clauses. */
10746 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
10749 tree new_clauses = NULL, nc, oc;
10751 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
10753 nc = copy_node (oc);
10754 OMP_CLAUSE_CHAIN (nc) = new_clauses;
10757 switch (OMP_CLAUSE_CODE (nc))
10759 case OMP_CLAUSE_LASTPRIVATE:
10760 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
10762 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
10763 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
10764 in_decl, /*integral_constant_expression_p=*/false);
10765 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
10766 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
10769 case OMP_CLAUSE_PRIVATE:
10770 case OMP_CLAUSE_SHARED:
10771 case OMP_CLAUSE_FIRSTPRIVATE:
10772 case OMP_CLAUSE_REDUCTION:
10773 case OMP_CLAUSE_COPYIN:
10774 case OMP_CLAUSE_COPYPRIVATE:
10775 case OMP_CLAUSE_IF:
10776 case OMP_CLAUSE_NUM_THREADS:
10777 case OMP_CLAUSE_SCHEDULE:
10778 case OMP_CLAUSE_COLLAPSE:
10779 OMP_CLAUSE_OPERAND (nc, 0)
10780 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
10781 in_decl, /*integral_constant_expression_p=*/false);
10783 case OMP_CLAUSE_NOWAIT:
10784 case OMP_CLAUSE_ORDERED:
10785 case OMP_CLAUSE_DEFAULT:
10786 case OMP_CLAUSE_UNTIED:
10789 gcc_unreachable ();
10793 return finish_omp_clauses (nreverse (new_clauses));
10796 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
10799 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
10802 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
10804 tree purpose, value, chain;
10809 if (TREE_CODE (t) != TREE_LIST)
10810 return tsubst_copy_and_build (t, args, complain, in_decl,
10811 /*function_p=*/false,
10812 /*integral_constant_expression_p=*/false);
10814 if (t == void_list_node)
10817 purpose = TREE_PURPOSE (t);
10819 purpose = RECUR (purpose);
10820 value = TREE_VALUE (t);
10822 value = RECUR (value);
10823 chain = TREE_CHAIN (t);
10824 if (chain && chain != void_type_node)
10825 chain = RECUR (chain);
10826 return tree_cons (purpose, value, chain);
10830 /* Substitute one OMP_FOR iterator. */
10833 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
10834 tree condv, tree incrv, tree *clauses,
10835 tree args, tsubst_flags_t complain, tree in_decl,
10836 bool integral_constant_expression_p)
10838 #define RECUR(NODE) \
10839 tsubst_expr ((NODE), args, complain, in_decl, \
10840 integral_constant_expression_p)
10841 tree decl, init, cond, incr, auto_node;
10843 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
10844 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
10845 decl = RECUR (TREE_OPERAND (init, 0));
10846 init = TREE_OPERAND (init, 1);
10847 auto_node = type_uses_auto (TREE_TYPE (decl));
10848 if (auto_node && init)
10850 tree init_expr = init;
10851 if (TREE_CODE (init_expr) == DECL_EXPR)
10852 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
10853 init_expr = RECUR (init_expr);
10855 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
10857 gcc_assert (!type_dependent_expression_p (decl));
10859 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
10861 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
10862 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
10863 if (TREE_CODE (incr) == MODIFY_EXPR)
10864 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
10865 RECUR (TREE_OPERAND (incr, 1)),
10868 incr = RECUR (incr);
10869 TREE_VEC_ELT (declv, i) = decl;
10870 TREE_VEC_ELT (initv, i) = init;
10871 TREE_VEC_ELT (condv, i) = cond;
10872 TREE_VEC_ELT (incrv, i) = incr;
10876 if (init && TREE_CODE (init) != DECL_EXPR)
10879 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
10881 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
10882 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
10883 && OMP_CLAUSE_DECL (c) == decl)
10885 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
10886 && OMP_CLAUSE_DECL (c) == decl)
10887 error ("iteration variable %qD should not be firstprivate", decl);
10888 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
10889 && OMP_CLAUSE_DECL (c) == decl)
10890 error ("iteration variable %qD should not be reduction", decl);
10894 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
10895 OMP_CLAUSE_DECL (c) = decl;
10896 c = finish_omp_clauses (c);
10899 OMP_CLAUSE_CHAIN (c) = *clauses;
10904 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
10905 if (COMPARISON_CLASS_P (cond))
10906 cond = build2 (TREE_CODE (cond), boolean_type_node,
10907 RECUR (TREE_OPERAND (cond, 0)),
10908 RECUR (TREE_OPERAND (cond, 1)));
10910 cond = RECUR (cond);
10911 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
10912 switch (TREE_CODE (incr))
10914 case PREINCREMENT_EXPR:
10915 case PREDECREMENT_EXPR:
10916 case POSTINCREMENT_EXPR:
10917 case POSTDECREMENT_EXPR:
10918 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
10919 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
10922 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
10923 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
10925 tree rhs = TREE_OPERAND (incr, 1);
10926 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
10927 RECUR (TREE_OPERAND (incr, 0)),
10928 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
10929 RECUR (TREE_OPERAND (rhs, 0)),
10930 RECUR (TREE_OPERAND (rhs, 1))));
10933 incr = RECUR (incr);
10936 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
10937 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
10939 tree lhs = RECUR (TREE_OPERAND (incr, 0));
10940 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
10941 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
10942 TREE_TYPE (decl), lhs,
10943 RECUR (TREE_OPERAND (incr, 2))));
10945 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
10946 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
10947 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
10949 tree rhs = TREE_OPERAND (incr, 2);
10950 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
10951 RECUR (TREE_OPERAND (incr, 0)),
10952 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
10953 RECUR (TREE_OPERAND (rhs, 0)),
10954 RECUR (TREE_OPERAND (rhs, 1))));
10957 incr = RECUR (incr);
10960 incr = RECUR (incr);
10964 TREE_VEC_ELT (declv, i) = decl;
10965 TREE_VEC_ELT (initv, i) = init;
10966 TREE_VEC_ELT (condv, i) = cond;
10967 TREE_VEC_ELT (incrv, i) = incr;
10971 /* Like tsubst_copy for expressions, etc. but also does semantic
10975 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
10976 bool integral_constant_expression_p)
10978 #define RECUR(NODE) \
10979 tsubst_expr ((NODE), args, complain, in_decl, \
10980 integral_constant_expression_p)
10984 if (t == NULL_TREE || t == error_mark_node)
10987 if (EXPR_HAS_LOCATION (t))
10988 input_location = EXPR_LOCATION (t);
10989 if (STATEMENT_CODE_P (TREE_CODE (t)))
10990 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
10992 switch (TREE_CODE (t))
10994 case STATEMENT_LIST:
10996 tree_stmt_iterator i;
10997 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
10998 RECUR (tsi_stmt (i));
11002 case CTOR_INITIALIZER:
11003 finish_mem_initializers (tsubst_initializer_list
11004 (TREE_OPERAND (t, 0), args));
11008 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
11012 tmp = RECUR (EXPR_STMT_EXPR (t));
11013 if (EXPR_STMT_STMT_EXPR_RESULT (t))
11014 finish_stmt_expr_expr (tmp, cur_stmt_expr);
11016 finish_expr_stmt (tmp);
11020 do_using_directive (RECUR (USING_STMT_NAMESPACE (t)));
11028 decl = DECL_EXPR_DECL (t);
11029 if (TREE_CODE (decl) == LABEL_DECL)
11030 finish_label_decl (DECL_NAME (decl));
11031 else if (TREE_CODE (decl) == USING_DECL)
11033 tree scope = USING_DECL_SCOPE (decl);
11034 tree name = DECL_NAME (decl);
11037 scope = RECUR (scope);
11038 decl = lookup_qualified_name (scope, name,
11039 /*is_type_p=*/false,
11040 /*complain=*/false);
11041 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
11042 qualified_name_lookup_error (scope, name, decl, input_location);
11044 do_local_using_decl (decl, scope, name);
11048 init = DECL_INITIAL (decl);
11049 decl = tsubst (decl, args, complain, in_decl);
11050 if (decl != error_mark_node)
11052 /* By marking the declaration as instantiated, we avoid
11053 trying to instantiate it. Since instantiate_decl can't
11054 handle local variables, and since we've already done
11055 all that needs to be done, that's the right thing to
11057 if (TREE_CODE (decl) == VAR_DECL)
11058 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11059 if (TREE_CODE (decl) == VAR_DECL
11060 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
11061 /* Anonymous aggregates are a special case. */
11062 finish_anon_union (decl);
11065 maybe_push_decl (decl);
11066 if (TREE_CODE (decl) == VAR_DECL
11067 && DECL_PRETTY_FUNCTION_P (decl))
11069 /* For __PRETTY_FUNCTION__ we have to adjust the
11071 const char *const name
11072 = cxx_printable_name (current_function_decl, 2);
11073 init = cp_fname_init (name, &TREE_TYPE (decl));
11077 tree t = RECUR (init);
11080 /* If we had an initializer but it
11081 instantiated to nothing,
11082 value-initialize the object. This will
11083 only occur when the initializer was a
11084 pack expansion where the parameter packs
11085 used in that expansion were of length
11087 init = build_value_init (TREE_TYPE (decl));
11092 cp_finish_decl (decl, init, false, NULL_TREE, 0);
11097 /* A DECL_EXPR can also be used as an expression, in the condition
11098 clause of an if/for/while construct. */
11103 stmt = begin_for_stmt ();
11104 RECUR (FOR_INIT_STMT (t));
11105 finish_for_init_stmt (stmt);
11106 tmp = RECUR (FOR_COND (t));
11107 finish_for_cond (tmp, stmt);
11108 tmp = RECUR (FOR_EXPR (t));
11109 finish_for_expr (tmp, stmt);
11110 RECUR (FOR_BODY (t));
11111 finish_for_stmt (stmt);
11115 stmt = begin_while_stmt ();
11116 tmp = RECUR (WHILE_COND (t));
11117 finish_while_stmt_cond (tmp, stmt);
11118 RECUR (WHILE_BODY (t));
11119 finish_while_stmt (stmt);
11123 stmt = begin_do_stmt ();
11124 RECUR (DO_BODY (t));
11125 finish_do_body (stmt);
11126 tmp = RECUR (DO_COND (t));
11127 finish_do_stmt (tmp, stmt);
11131 stmt = begin_if_stmt ();
11132 tmp = RECUR (IF_COND (t));
11133 finish_if_stmt_cond (tmp, stmt);
11134 RECUR (THEN_CLAUSE (t));
11135 finish_then_clause (stmt);
11137 if (ELSE_CLAUSE (t))
11139 begin_else_clause (stmt);
11140 RECUR (ELSE_CLAUSE (t));
11141 finish_else_clause (stmt);
11144 finish_if_stmt (stmt);
11148 if (BIND_EXPR_BODY_BLOCK (t))
11149 stmt = begin_function_body ();
11151 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
11152 ? BCS_TRY_BLOCK : 0);
11154 RECUR (BIND_EXPR_BODY (t));
11156 if (BIND_EXPR_BODY_BLOCK (t))
11157 finish_function_body (stmt);
11159 finish_compound_stmt (stmt);
11163 finish_break_stmt ();
11166 case CONTINUE_STMT:
11167 finish_continue_stmt ();
11171 stmt = begin_switch_stmt ();
11172 tmp = RECUR (SWITCH_STMT_COND (t));
11173 finish_switch_cond (tmp, stmt);
11174 RECUR (SWITCH_STMT_BODY (t));
11175 finish_switch_stmt (stmt);
11178 case CASE_LABEL_EXPR:
11179 finish_case_label (EXPR_LOCATION (t),
11180 RECUR (CASE_LOW (t)),
11181 RECUR (CASE_HIGH (t)));
11186 tree decl = LABEL_EXPR_LABEL (t);
11189 label = finish_label_stmt (DECL_NAME (decl));
11190 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
11191 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
11196 tmp = GOTO_DESTINATION (t);
11197 if (TREE_CODE (tmp) != LABEL_DECL)
11198 /* Computed goto's must be tsubst'd into. On the other hand,
11199 non-computed gotos must not be; the identifier in question
11200 will have no binding. */
11203 tmp = DECL_NAME (tmp);
11204 finish_goto_stmt (tmp);
11208 tmp = finish_asm_stmt
11209 (ASM_VOLATILE_P (t),
11210 RECUR (ASM_STRING (t)),
11211 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
11212 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
11213 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl));
11215 tree asm_expr = tmp;
11216 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
11217 asm_expr = TREE_OPERAND (asm_expr, 0);
11218 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
11225 stmt = begin_try_block ();
11226 RECUR (TRY_STMTS (t));
11227 finish_cleanup_try_block (stmt);
11228 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
11232 tree compound_stmt = NULL_TREE;
11234 if (FN_TRY_BLOCK_P (t))
11235 stmt = begin_function_try_block (&compound_stmt);
11237 stmt = begin_try_block ();
11239 RECUR (TRY_STMTS (t));
11241 if (FN_TRY_BLOCK_P (t))
11242 finish_function_try_block (stmt);
11244 finish_try_block (stmt);
11246 RECUR (TRY_HANDLERS (t));
11247 if (FN_TRY_BLOCK_P (t))
11248 finish_function_handler_sequence (stmt, compound_stmt);
11250 finish_handler_sequence (stmt);
11256 tree decl = HANDLER_PARMS (t);
11260 decl = tsubst (decl, args, complain, in_decl);
11261 /* Prevent instantiate_decl from trying to instantiate
11262 this variable. We've already done all that needs to be
11264 if (decl != error_mark_node)
11265 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11267 stmt = begin_handler ();
11268 finish_handler_parms (decl, stmt);
11269 RECUR (HANDLER_BODY (t));
11270 finish_handler (stmt);
11275 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
11278 case STATIC_ASSERT:
11281 tsubst_expr (STATIC_ASSERT_CONDITION (t),
11284 /*integral_constant_expression_p=*/true);
11285 finish_static_assert (condition,
11286 STATIC_ASSERT_MESSAGE (t),
11287 STATIC_ASSERT_SOURCE_LOCATION (t),
11288 /*member_p=*/false);
11293 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
11294 args, complain, in_decl);
11295 stmt = begin_omp_parallel ();
11296 RECUR (OMP_PARALLEL_BODY (t));
11297 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
11298 = OMP_PARALLEL_COMBINED (t);
11302 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
11303 args, complain, in_decl);
11304 stmt = begin_omp_task ();
11305 RECUR (OMP_TASK_BODY (t));
11306 finish_omp_task (tmp, stmt);
11311 tree clauses, body, pre_body;
11312 tree declv, initv, condv, incrv;
11315 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
11316 args, complain, in_decl);
11317 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11318 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11319 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11320 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11322 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
11323 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
11324 &clauses, args, complain, in_decl,
11325 integral_constant_expression_p);
11327 stmt = begin_omp_structured_block ();
11329 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
11330 if (TREE_VEC_ELT (initv, i) == NULL
11331 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
11332 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
11333 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
11335 tree init = RECUR (TREE_VEC_ELT (initv, i));
11336 gcc_assert (init == TREE_VEC_ELT (declv, i));
11337 TREE_VEC_ELT (initv, i) = NULL_TREE;
11341 tree decl_expr = TREE_VEC_ELT (initv, i);
11342 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
11343 gcc_assert (init != NULL);
11344 TREE_VEC_ELT (initv, i) = RECUR (init);
11345 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
11347 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
11350 pre_body = push_stmt_list ();
11351 RECUR (OMP_FOR_PRE_BODY (t));
11352 pre_body = pop_stmt_list (pre_body);
11354 body = push_stmt_list ();
11355 RECUR (OMP_FOR_BODY (t));
11356 body = pop_stmt_list (body);
11358 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
11359 body, pre_body, clauses);
11361 add_stmt (finish_omp_structured_block (stmt));
11367 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
11368 stmt = push_stmt_list ();
11369 RECUR (OMP_BODY (t));
11370 stmt = pop_stmt_list (stmt);
11373 OMP_BODY (t) = stmt;
11374 OMP_CLAUSES (t) = tmp;
11382 stmt = push_stmt_list ();
11383 RECUR (OMP_BODY (t));
11384 stmt = pop_stmt_list (stmt);
11387 OMP_BODY (t) = stmt;
11392 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
11394 tree op1 = TREE_OPERAND (t, 1);
11395 tree lhs = RECUR (TREE_OPERAND (op1, 0));
11396 tree rhs = RECUR (TREE_OPERAND (op1, 1));
11397 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
11401 case EXPR_PACK_EXPANSION:
11402 error ("invalid use of pack expansion expression");
11403 return error_mark_node;
11405 case NONTYPE_ARGUMENT_PACK:
11406 error ("use %<...%> to expand argument pack");
11407 return error_mark_node;
11410 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
11412 return tsubst_copy_and_build (t, args, complain, in_decl,
11413 /*function_p=*/false,
11414 integral_constant_expression_p);
11421 /* T is a postfix-expression that is not being used in a function
11422 call. Return the substituted version of T. */
11425 tsubst_non_call_postfix_expression (tree t, tree args,
11426 tsubst_flags_t complain,
11429 if (TREE_CODE (t) == SCOPE_REF)
11430 t = tsubst_qualified_id (t, args, complain, in_decl,
11431 /*done=*/false, /*address_p=*/false);
11433 t = tsubst_copy_and_build (t, args, complain, in_decl,
11434 /*function_p=*/false,
11435 /*integral_constant_expression_p=*/false);
11440 /* Like tsubst but deals with expressions and performs semantic
11441 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11444 tsubst_copy_and_build (tree t,
11446 tsubst_flags_t complain,
11449 bool integral_constant_expression_p)
11451 #define RECUR(NODE) \
11452 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11453 /*function_p=*/false, \
11454 integral_constant_expression_p)
11458 if (t == NULL_TREE || t == error_mark_node)
11461 switch (TREE_CODE (t))
11465 /* Fall through. */
11466 case IDENTIFIER_NODE:
11470 bool non_integral_constant_expression_p;
11471 const char *error_msg;
11473 if (IDENTIFIER_TYPENAME_P (t))
11475 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11476 t = mangle_conv_op_name_for_type (new_type);
11479 /* Look up the name. */
11480 decl = lookup_name (t);
11482 /* By convention, expressions use ERROR_MARK_NODE to indicate
11483 failure, not NULL_TREE. */
11484 if (decl == NULL_TREE)
11485 decl = error_mark_node;
11487 decl = finish_id_expression (t, decl, NULL_TREE,
11489 integral_constant_expression_p,
11490 /*allow_non_integral_constant_expression_p=*/false,
11491 &non_integral_constant_expression_p,
11492 /*template_p=*/false,
11494 /*address_p=*/false,
11495 /*template_arg_p=*/false,
11500 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
11501 decl = unqualified_name_lookup_error (decl);
11505 case TEMPLATE_ID_EXPR:
11508 tree templ = RECUR (TREE_OPERAND (t, 0));
11509 tree targs = TREE_OPERAND (t, 1);
11512 targs = tsubst_template_args (targs, args, complain, in_decl);
11514 if (TREE_CODE (templ) == COMPONENT_REF)
11516 object = TREE_OPERAND (templ, 0);
11517 templ = TREE_OPERAND (templ, 1);
11520 object = NULL_TREE;
11521 templ = lookup_template_function (templ, targs);
11524 return build3 (COMPONENT_REF, TREE_TYPE (templ),
11525 object, templ, NULL_TREE);
11527 return baselink_for_fns (templ);
11532 tree r = RECUR (TREE_OPERAND (t, 0));
11534 if (REFERENCE_REF_P (t))
11536 /* A type conversion to reference type will be enclosed in
11537 such an indirect ref, but the substitution of the cast
11538 will have also added such an indirect ref. */
11539 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
11540 r = convert_from_reference (r);
11543 r = build_x_indirect_ref (r, "unary *", complain);
11549 (tsubst (TREE_TYPE (t), args, complain, in_decl),
11550 RECUR (TREE_OPERAND (t, 0)));
11553 case REINTERPRET_CAST_EXPR:
11554 case CONST_CAST_EXPR:
11555 case DYNAMIC_CAST_EXPR:
11556 case STATIC_CAST_EXPR:
11561 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11562 if (integral_constant_expression_p
11563 && !cast_valid_in_integral_constant_expression_p (type))
11565 if (complain & tf_error)
11566 error ("a cast to a type other than an integral or "
11567 "enumeration type cannot appear in a constant-expression");
11568 return error_mark_node;
11571 op = RECUR (TREE_OPERAND (t, 0));
11573 switch (TREE_CODE (t))
11576 return build_functional_cast (type, op, complain);
11577 case REINTERPRET_CAST_EXPR:
11578 return build_reinterpret_cast (type, op, complain);
11579 case CONST_CAST_EXPR:
11580 return build_const_cast (type, op, complain);
11581 case DYNAMIC_CAST_EXPR:
11582 return build_dynamic_cast (type, op, complain);
11583 case STATIC_CAST_EXPR:
11584 return build_static_cast (type, op, complain);
11586 gcc_unreachable ();
11590 case POSTDECREMENT_EXPR:
11591 case POSTINCREMENT_EXPR:
11592 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11593 args, complain, in_decl);
11594 return build_x_unary_op (TREE_CODE (t), op1, complain);
11596 case PREDECREMENT_EXPR:
11597 case PREINCREMENT_EXPR:
11601 case TRUTH_NOT_EXPR:
11602 case UNARY_PLUS_EXPR: /* Unary + */
11603 case REALPART_EXPR:
11604 case IMAGPART_EXPR:
11605 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
11609 op1 = TREE_OPERAND (t, 0);
11610 if (TREE_CODE (op1) == SCOPE_REF)
11611 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
11612 /*done=*/true, /*address_p=*/true);
11614 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
11616 if (TREE_CODE (op1) == LABEL_DECL)
11617 return finish_label_address_expr (DECL_NAME (op1),
11618 EXPR_LOCATION (op1));
11619 return build_x_unary_op (ADDR_EXPR, op1, complain);
11624 case TRUNC_DIV_EXPR:
11625 case CEIL_DIV_EXPR:
11626 case FLOOR_DIV_EXPR:
11627 case ROUND_DIV_EXPR:
11628 case EXACT_DIV_EXPR:
11632 case TRUNC_MOD_EXPR:
11633 case FLOOR_MOD_EXPR:
11634 case TRUTH_ANDIF_EXPR:
11635 case TRUTH_ORIF_EXPR:
11636 case TRUTH_AND_EXPR:
11637 case TRUTH_OR_EXPR:
11652 return build_x_binary_op
11654 RECUR (TREE_OPERAND (t, 0)),
11655 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
11657 : TREE_CODE (TREE_OPERAND (t, 0))),
11658 RECUR (TREE_OPERAND (t, 1)),
11659 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
11661 : TREE_CODE (TREE_OPERAND (t, 1))),
11662 /*overloaded_p=*/NULL,
11666 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
11667 /*address_p=*/false);
11669 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11670 args, complain, in_decl);
11671 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
11674 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11675 return tsubst_copy (t, args, complain, in_decl);
11679 op1 = TREE_OPERAND (t, 0);
11682 /* When there are no ARGS, we are trying to evaluate a
11683 non-dependent expression from the parser. Trying to do
11684 the substitutions may not work. */
11686 op1 = TREE_TYPE (op1);
11690 ++cp_unevaluated_operand;
11691 ++c_inhibit_evaluation_warnings;
11692 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
11693 /*function_p=*/false,
11694 /*integral_constant_expression_p=*/false);
11695 --cp_unevaluated_operand;
11696 --c_inhibit_evaluation_warnings;
11699 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
11700 complain & tf_error);
11702 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
11703 complain & tf_error);
11707 tree r = build_x_modify_expr
11708 (RECUR (TREE_OPERAND (t, 0)),
11709 TREE_CODE (TREE_OPERAND (t, 1)),
11710 RECUR (TREE_OPERAND (t, 2)),
11712 /* TREE_NO_WARNING must be set if either the expression was
11713 parenthesized or it uses an operator such as >>= rather
11714 than plain assignment. In the former case, it was already
11715 set and must be copied. In the latter case,
11716 build_x_modify_expr sets it and it must not be reset
11718 if (TREE_NO_WARNING (t))
11719 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11724 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11725 args, complain, in_decl);
11726 /* Remember that there was a reference to this entity. */
11729 return build_x_arrow (op1);
11733 tree placement = RECUR (TREE_OPERAND (t, 0));
11734 tree init = RECUR (TREE_OPERAND (t, 3));
11735 VEC(tree,gc) *placement_vec;
11736 VEC(tree,gc) *init_vec;
11739 if (placement == NULL_TREE)
11740 placement_vec = NULL;
11743 placement_vec = make_tree_vector ();
11744 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
11745 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
11748 /* If there was an initializer in the original tree, but it
11749 instantiated to an empty list, then we should pass a
11750 non-NULL empty vector to tell build_new that it was an
11751 empty initializer() rather than no initializer. This can
11752 only happen when the initializer is a pack expansion whose
11753 parameter packs are of length zero. */
11754 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
11758 init_vec = make_tree_vector ();
11759 if (init == void_zero_node)
11760 gcc_assert (init_vec != NULL);
11763 for (; init != NULL_TREE; init = TREE_CHAIN (init))
11764 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
11768 ret = build_new (&placement_vec,
11769 RECUR (TREE_OPERAND (t, 1)),
11770 RECUR (TREE_OPERAND (t, 2)),
11772 NEW_EXPR_USE_GLOBAL (t),
11775 if (placement_vec != NULL)
11776 release_tree_vector (placement_vec);
11777 if (init_vec != NULL)
11778 release_tree_vector (init_vec);
11784 return delete_sanity
11785 (RECUR (TREE_OPERAND (t, 0)),
11786 RECUR (TREE_OPERAND (t, 1)),
11787 DELETE_EXPR_USE_VEC (t),
11788 DELETE_EXPR_USE_GLOBAL (t));
11790 case COMPOUND_EXPR:
11791 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
11792 RECUR (TREE_OPERAND (t, 1)),
11798 VEC(tree,gc) *call_args;
11799 unsigned int nargs, i;
11804 function = CALL_EXPR_FN (t);
11805 /* When we parsed the expression, we determined whether or
11806 not Koenig lookup should be performed. */
11807 koenig_p = KOENIG_LOOKUP_P (t);
11808 if (TREE_CODE (function) == SCOPE_REF)
11810 qualified_p = true;
11811 function = tsubst_qualified_id (function, args, complain, in_decl,
11813 /*address_p=*/false);
11817 if (TREE_CODE (function) == COMPONENT_REF)
11819 tree op = TREE_OPERAND (function, 1);
11821 qualified_p = (TREE_CODE (op) == SCOPE_REF
11822 || (BASELINK_P (op)
11823 && BASELINK_QUALIFIED_P (op)));
11826 qualified_p = false;
11828 function = tsubst_copy_and_build (function, args, complain,
11831 integral_constant_expression_p);
11833 if (BASELINK_P (function))
11834 qualified_p = true;
11837 nargs = call_expr_nargs (t);
11838 call_args = make_tree_vector ();
11839 for (i = 0; i < nargs; ++i)
11841 tree arg = CALL_EXPR_ARG (t, i);
11843 if (!PACK_EXPANSION_P (arg))
11844 VEC_safe_push (tree, gc, call_args,
11845 RECUR (CALL_EXPR_ARG (t, i)));
11848 /* Expand the pack expansion and push each entry onto
11850 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
11851 if (TREE_CODE (arg) == TREE_VEC)
11853 unsigned int len, j;
11855 len = TREE_VEC_LENGTH (arg);
11856 for (j = 0; j < len; ++j)
11858 tree value = TREE_VEC_ELT (arg, j);
11859 if (value != NULL_TREE)
11860 value = convert_from_reference (value);
11861 VEC_safe_push (tree, gc, call_args, value);
11866 /* A partial substitution. Add one entry. */
11867 VEC_safe_push (tree, gc, call_args, arg);
11872 /* We do not perform argument-dependent lookup if normal
11873 lookup finds a non-function, in accordance with the
11874 expected resolution of DR 218. */
11876 && ((is_overloaded_fn (function)
11877 /* If lookup found a member function, the Koenig lookup is
11878 not appropriate, even if an unqualified-name was used
11879 to denote the function. */
11880 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
11881 || TREE_CODE (function) == IDENTIFIER_NODE)
11882 /* Only do this when substitution turns a dependent call
11883 into a non-dependent call. */
11884 && type_dependent_expression_p_push (t)
11885 && !any_type_dependent_arguments_p (call_args))
11886 function = perform_koenig_lookup (function, call_args);
11888 if (TREE_CODE (function) == IDENTIFIER_NODE)
11890 unqualified_name_lookup_error (function);
11891 release_tree_vector (call_args);
11892 return error_mark_node;
11895 /* Remember that there was a reference to this entity. */
11896 if (DECL_P (function))
11897 mark_used (function);
11899 if (TREE_CODE (function) == OFFSET_REF)
11900 ret = build_offset_ref_call_from_tree (function, &call_args);
11901 else if (TREE_CODE (function) == COMPONENT_REF)
11903 if (!BASELINK_P (TREE_OPERAND (function, 1)))
11904 ret = finish_call_expr (function, &call_args,
11905 /*disallow_virtual=*/false,
11906 /*koenig_p=*/false,
11909 ret = (build_new_method_call
11910 (TREE_OPERAND (function, 0),
11911 TREE_OPERAND (function, 1),
11912 &call_args, NULL_TREE,
11913 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
11918 ret = finish_call_expr (function, &call_args,
11919 /*disallow_virtual=*/qualified_p,
11923 release_tree_vector (call_args);
11929 return build_x_conditional_expr
11930 (RECUR (TREE_OPERAND (t, 0)),
11931 RECUR (TREE_OPERAND (t, 1)),
11932 RECUR (TREE_OPERAND (t, 2)),
11935 case PSEUDO_DTOR_EXPR:
11936 return finish_pseudo_destructor_expr
11937 (RECUR (TREE_OPERAND (t, 0)),
11938 RECUR (TREE_OPERAND (t, 1)),
11939 RECUR (TREE_OPERAND (t, 2)));
11943 tree purpose, value, chain;
11945 if (t == void_list_node)
11948 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
11949 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
11951 /* We have pack expansions, so expand those and
11952 create a new list out of it. */
11953 tree purposevec = NULL_TREE;
11954 tree valuevec = NULL_TREE;
11958 /* Expand the argument expressions. */
11959 if (TREE_PURPOSE (t))
11960 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
11961 complain, in_decl);
11962 if (TREE_VALUE (t))
11963 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
11964 complain, in_decl);
11966 /* Build the rest of the list. */
11967 chain = TREE_CHAIN (t);
11968 if (chain && chain != void_type_node)
11969 chain = RECUR (chain);
11971 /* Determine the number of arguments. */
11972 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
11974 len = TREE_VEC_LENGTH (purposevec);
11975 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
11977 else if (TREE_CODE (valuevec) == TREE_VEC)
11978 len = TREE_VEC_LENGTH (valuevec);
11981 /* Since we only performed a partial substitution into
11982 the argument pack, we only return a single list
11984 if (purposevec == TREE_PURPOSE (t)
11985 && valuevec == TREE_VALUE (t)
11986 && chain == TREE_CHAIN (t))
11989 return tree_cons (purposevec, valuevec, chain);
11992 /* Convert the argument vectors into a TREE_LIST */
11996 /* Grab the Ith values. */
11998 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
12001 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
12004 /* Build the list (backwards). */
12005 chain = tree_cons (purpose, value, chain);
12011 purpose = TREE_PURPOSE (t);
12013 purpose = RECUR (purpose);
12014 value = TREE_VALUE (t);
12016 value = RECUR (value);
12017 chain = TREE_CHAIN (t);
12018 if (chain && chain != void_type_node)
12019 chain = RECUR (chain);
12020 if (purpose == TREE_PURPOSE (t)
12021 && value == TREE_VALUE (t)
12022 && chain == TREE_CHAIN (t))
12024 return tree_cons (purpose, value, chain);
12027 case COMPONENT_REF:
12033 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12034 args, complain, in_decl);
12035 /* Remember that there was a reference to this entity. */
12036 if (DECL_P (object))
12037 mark_used (object);
12038 object_type = TREE_TYPE (object);
12040 member = TREE_OPERAND (t, 1);
12041 if (BASELINK_P (member))
12042 member = tsubst_baselink (member,
12043 non_reference (TREE_TYPE (object)),
12044 args, complain, in_decl);
12046 member = tsubst_copy (member, args, complain, in_decl);
12047 if (member == error_mark_node)
12048 return error_mark_node;
12050 if (object_type && !CLASS_TYPE_P (object_type))
12052 if (SCALAR_TYPE_P (object_type))
12054 tree s = NULL_TREE;
12055 tree dtor = member;
12057 if (TREE_CODE (dtor) == SCOPE_REF)
12059 s = TREE_OPERAND (dtor, 0);
12060 dtor = TREE_OPERAND (dtor, 1);
12062 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
12064 dtor = TREE_OPERAND (dtor, 0);
12066 return finish_pseudo_destructor_expr (object, s, dtor);
12070 else if (TREE_CODE (member) == SCOPE_REF
12071 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
12076 /* Lookup the template functions now that we know what the
12078 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
12079 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
12080 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
12081 /*is_type_p=*/false,
12082 /*complain=*/false);
12083 if (BASELINK_P (member))
12085 BASELINK_FUNCTIONS (member)
12086 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
12088 member = (adjust_result_of_qualified_name_lookup
12089 (member, BINFO_TYPE (BASELINK_BINFO (member)),
12094 qualified_name_lookup_error (object_type, tmpl, member,
12096 return error_mark_node;
12099 else if (TREE_CODE (member) == SCOPE_REF
12100 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
12101 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
12103 if (complain & tf_error)
12105 if (TYPE_P (TREE_OPERAND (member, 0)))
12106 error ("%qT is not a class or namespace",
12107 TREE_OPERAND (member, 0));
12109 error ("%qD is not a class or namespace",
12110 TREE_OPERAND (member, 0));
12112 return error_mark_node;
12114 else if (TREE_CODE (member) == FIELD_DECL)
12115 return finish_non_static_data_member (member, object, NULL_TREE);
12117 return finish_class_member_access_expr (object, member,
12118 /*template_p=*/false,
12124 (RECUR (TREE_OPERAND (t, 0)));
12128 VEC(constructor_elt,gc) *n;
12129 constructor_elt *ce;
12130 unsigned HOST_WIDE_INT idx;
12131 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12132 bool process_index_p;
12134 bool need_copy_p = false;
12137 if (type == error_mark_node)
12138 return error_mark_node;
12140 /* digest_init will do the wrong thing if we let it. */
12141 if (type && TYPE_PTRMEMFUNC_P (type))
12144 /* We do not want to process the index of aggregate
12145 initializers as they are identifier nodes which will be
12146 looked up by digest_init. */
12147 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
12149 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
12150 newlen = VEC_length (constructor_elt, n);
12151 for (idx = 0; VEC_iterate (constructor_elt, n, idx, ce); idx++)
12153 if (ce->index && process_index_p)
12154 ce->index = RECUR (ce->index);
12156 if (PACK_EXPANSION_P (ce->value))
12158 /* Substitute into the pack expansion. */
12159 ce->value = tsubst_pack_expansion (ce->value, args, complain,
12162 if (ce->value == error_mark_node)
12164 else if (TREE_VEC_LENGTH (ce->value) == 1)
12165 /* Just move the argument into place. */
12166 ce->value = TREE_VEC_ELT (ce->value, 0);
12169 /* Update the length of the final CONSTRUCTOR
12170 arguments vector, and note that we will need to
12172 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
12173 need_copy_p = true;
12177 ce->value = RECUR (ce->value);
12182 VEC(constructor_elt,gc) *old_n = n;
12184 n = VEC_alloc (constructor_elt, gc, newlen);
12185 for (idx = 0; VEC_iterate (constructor_elt, old_n, idx, ce);
12188 if (TREE_CODE (ce->value) == TREE_VEC)
12190 int i, len = TREE_VEC_LENGTH (ce->value);
12191 for (i = 0; i < len; ++i)
12192 CONSTRUCTOR_APPEND_ELT (n, 0,
12193 TREE_VEC_ELT (ce->value, i));
12196 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
12200 r = build_constructor (init_list_type_node, n);
12201 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
12203 if (TREE_HAS_CONSTRUCTOR (t))
12204 return finish_compound_literal (type, r);
12211 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
12212 if (TYPE_P (operand_0))
12213 return get_typeid (operand_0);
12214 return build_typeid (operand_0);
12224 tree r = tsubst_copy (t, args, complain, in_decl);
12226 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
12227 /* If the original type was a reference, we'll be wrapped in
12228 the appropriate INDIRECT_REF. */
12229 r = convert_from_reference (r);
12234 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
12235 tsubst_copy (TREE_TYPE (t), args, complain,
12238 case OFFSETOF_EXPR:
12239 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
12243 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
12244 complain, in_decl);
12246 tree type2 = TRAIT_EXPR_TYPE2 (t);
12248 type2 = tsubst_copy (type2, args, complain, in_decl);
12250 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
12255 tree old_stmt_expr = cur_stmt_expr;
12256 tree stmt_expr = begin_stmt_expr ();
12258 cur_stmt_expr = stmt_expr;
12259 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
12260 integral_constant_expression_p);
12261 stmt_expr = finish_stmt_expr (stmt_expr, false);
12262 cur_stmt_expr = old_stmt_expr;
12268 t = tsubst_copy (t, args, complain, in_decl);
12269 /* As in finish_id_expression, we resolve enumeration constants
12270 to their underlying values. */
12271 if (TREE_CODE (t) == CONST_DECL)
12273 used_types_insert (TREE_TYPE (t));
12274 return DECL_INITIAL (t);
12279 /* Handle Objective-C++ constructs, if appropriate. */
12282 = objcp_tsubst_copy_and_build (t, args, complain,
12283 in_decl, /*function_p=*/false);
12287 return tsubst_copy (t, args, complain, in_decl);
12293 /* Verify that the instantiated ARGS are valid. For type arguments,
12294 make sure that the type is not variably modified. For non-type arguments,
12295 make sure they are constants if they are integral or enumerations.
12296 Emit an error under control of COMPLAIN, and return TRUE on error. */
12299 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
12301 if (ARGUMENT_PACK_P (t))
12303 tree vec = ARGUMENT_PACK_ARGS (t);
12304 int len = TREE_VEC_LENGTH (vec);
12305 bool result = false;
12308 for (i = 0; i < len; ++i)
12309 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
12313 else if (TYPE_P (t))
12315 if (variably_modified_type_p (t, NULL_TREE))
12317 if (complain & tf_error)
12318 error ("%qT is a variably modified type", t);
12322 /* A non-type argument of integral or enumerated type must be a
12324 else if (TREE_TYPE (t)
12325 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
12326 && !TREE_CONSTANT (t))
12328 if (complain & tf_error)
12329 error ("integral expression %qE is not constant", t);
12336 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
12338 int ix, len = DECL_NTPARMS (tmpl);
12339 bool result = false;
12341 for (ix = 0; ix != len; ix++)
12343 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
12346 if (result && (complain & tf_error))
12347 error (" trying to instantiate %qD", tmpl);
12351 /* Instantiate the indicated variable or function template TMPL with
12352 the template arguments in TARG_PTR. */
12355 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
12357 tree targ_ptr = orig_args;
12361 HOST_WIDE_INT saved_processing_template_decl;
12363 if (tmpl == error_mark_node)
12364 return error_mark_node;
12366 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
12368 /* If this function is a clone, handle it specially. */
12369 if (DECL_CLONED_FUNCTION_P (tmpl))
12374 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
12375 DECL_CLONED_FUNCTION. */
12376 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
12377 targ_ptr, complain);
12378 if (spec == error_mark_node)
12379 return error_mark_node;
12381 /* Look for the clone. */
12382 FOR_EACH_CLONE (clone, spec)
12383 if (DECL_NAME (clone) == DECL_NAME (tmpl))
12385 /* We should always have found the clone by now. */
12386 gcc_unreachable ();
12390 /* Check to see if we already have this specialization. */
12391 gen_tmpl = most_general_template (tmpl);
12392 if (tmpl != gen_tmpl)
12393 /* The TMPL is a partial instantiation. To get a full set of
12394 arguments we must add the arguments used to perform the
12395 partial instantiation. */
12396 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
12399 /* It would be nice to avoid hashing here and then again in tsubst_decl,
12400 but it doesn't seem to be on the hot path. */
12401 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
12403 gcc_assert (tmpl == gen_tmpl
12404 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
12406 || fndecl == NULL_TREE);
12408 if (spec != NULL_TREE)
12411 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
12413 return error_mark_node;
12415 /* We are building a FUNCTION_DECL, during which the access of its
12416 parameters and return types have to be checked. However this
12417 FUNCTION_DECL which is the desired context for access checking
12418 is not built yet. We solve this chicken-and-egg problem by
12419 deferring all checks until we have the FUNCTION_DECL. */
12420 push_deferring_access_checks (dk_deferred);
12422 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
12423 (because, for example, we have encountered a non-dependent
12424 function call in the body of a template function and must now
12425 determine which of several overloaded functions will be called),
12426 within the instantiation itself we are not processing a
12428 saved_processing_template_decl = processing_template_decl;
12429 processing_template_decl = 0;
12430 /* Substitute template parameters to obtain the specialization. */
12431 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
12432 targ_ptr, complain, gen_tmpl);
12433 processing_template_decl = saved_processing_template_decl;
12434 if (fndecl == error_mark_node)
12435 return error_mark_node;
12437 /* Now we know the specialization, compute access previously
12439 push_access_scope (fndecl);
12441 /* Some typedefs referenced from within the template code need to be access
12442 checked at template instantiation time, i.e now. These types were
12443 added to the template at parsing time. Let's get those and perfom
12444 the acces checks then. */
12445 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
12446 perform_deferred_access_checks ();
12447 pop_access_scope (fndecl);
12448 pop_deferring_access_checks ();
12450 /* The DECL_TI_TEMPLATE should always be the immediate parent
12451 template, not the most general template. */
12452 DECL_TI_TEMPLATE (fndecl) = tmpl;
12454 /* If we've just instantiated the main entry point for a function,
12455 instantiate all the alternate entry points as well. We do this
12456 by cloning the instantiation of the main entry point, not by
12457 instantiating the template clones. */
12458 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
12459 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
12464 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
12465 NARGS elements of the arguments that are being used when calling
12466 it. TARGS is a vector into which the deduced template arguments
12469 Return zero for success, 2 for an incomplete match that doesn't resolve
12470 all the types, and 1 for complete failure. An error message will be
12471 printed only for an incomplete match.
12473 If FN is a conversion operator, or we are trying to produce a specific
12474 specialization, RETURN_TYPE is the return type desired.
12476 The EXPLICIT_TARGS are explicit template arguments provided via a
12479 The parameter STRICT is one of:
12482 We are deducing arguments for a function call, as in
12483 [temp.deduct.call].
12486 We are deducing arguments for a conversion function, as in
12487 [temp.deduct.conv].
12490 We are deducing arguments when doing an explicit instantiation
12491 as in [temp.explicit], when determining an explicit specialization
12492 as in [temp.expl.spec], or when taking the address of a function
12493 template, as in [temp.deduct.funcaddr]. */
12496 fn_type_unification (tree fn,
12497 tree explicit_targs,
12500 unsigned int nargs,
12502 unification_kind_t strict,
12508 bool incomplete_argument_packs_p = false;
12510 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
12512 fntype = TREE_TYPE (fn);
12513 if (explicit_targs)
12517 The specified template arguments must match the template
12518 parameters in kind (i.e., type, nontype, template), and there
12519 must not be more arguments than there are parameters;
12520 otherwise type deduction fails.
12522 Nontype arguments must match the types of the corresponding
12523 nontype template parameters, or must be convertible to the
12524 types of the corresponding nontype parameters as specified in
12525 _temp.arg.nontype_, otherwise type deduction fails.
12527 All references in the function type of the function template
12528 to the corresponding template parameters are replaced by the
12529 specified template argument values. If a substitution in a
12530 template parameter or in the function type of the function
12531 template results in an invalid type, type deduction fails. */
12532 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
12533 int i, len = TREE_VEC_LENGTH (tparms);
12534 tree converted_args;
12535 bool incomplete = false;
12537 if (explicit_targs == error_mark_node)
12541 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
12542 /*require_all_args=*/false,
12543 /*use_default_args=*/false));
12544 if (converted_args == error_mark_node)
12547 /* Substitute the explicit args into the function type. This is
12548 necessary so that, for instance, explicitly declared function
12549 arguments can match null pointed constants. If we were given
12550 an incomplete set of explicit args, we must not do semantic
12551 processing during substitution as we could create partial
12553 for (i = 0; i < len; i++)
12555 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12556 bool parameter_pack = false;
12558 /* Dig out the actual parm. */
12559 if (TREE_CODE (parm) == TYPE_DECL
12560 || TREE_CODE (parm) == TEMPLATE_DECL)
12562 parm = TREE_TYPE (parm);
12563 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
12565 else if (TREE_CODE (parm) == PARM_DECL)
12567 parm = DECL_INITIAL (parm);
12568 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
12571 if (parameter_pack)
12575 template_parm_level_and_index (parm, &level, &idx);
12577 /* Mark the argument pack as "incomplete". We could
12578 still deduce more arguments during unification. */
12579 targ = TMPL_ARG (converted_args, level, idx);
12582 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
12583 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
12584 = ARGUMENT_PACK_ARGS (targ);
12587 /* We have some incomplete argument packs. */
12588 incomplete_argument_packs_p = true;
12592 if (incomplete_argument_packs_p)
12593 /* Any substitution is guaranteed to be incomplete if there
12594 are incomplete argument packs, because we can still deduce
12598 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
12600 processing_template_decl += incomplete;
12601 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
12602 processing_template_decl -= incomplete;
12604 if (fntype == error_mark_node)
12607 /* Place the explicitly specified arguments in TARGS. */
12608 for (i = NUM_TMPL_ARGS (converted_args); i--;)
12609 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
12612 /* Never do unification on the 'this' parameter. */
12613 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
12619 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
12620 new_args = XALLOCAVEC (tree, nargs + 1);
12621 new_args[0] = return_type;
12622 memcpy (new_args + 1, args, nargs * sizeof (tree));
12627 /* We allow incomplete unification without an error message here
12628 because the standard doesn't seem to explicitly prohibit it. Our
12629 callers must be ready to deal with unification failures in any
12631 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
12632 targs, parms, args, nargs, /*subr=*/0,
12635 if (result == 0 && incomplete_argument_packs_p)
12637 int i, len = NUM_TMPL_ARGS (targs);
12639 /* Clear the "incomplete" flags on all argument packs. */
12640 for (i = 0; i < len; i++)
12642 tree arg = TREE_VEC_ELT (targs, i);
12643 if (ARGUMENT_PACK_P (arg))
12645 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
12646 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
12651 /* Now that we have bindings for all of the template arguments,
12652 ensure that the arguments deduced for the template template
12653 parameters have compatible template parameter lists. We cannot
12654 check this property before we have deduced all template
12655 arguments, because the template parameter types of a template
12656 template parameter might depend on prior template parameters
12657 deduced after the template template parameter. The following
12658 ill-formed example illustrates this issue:
12660 template<typename T, template<T> class C> void f(C<5>, T);
12662 template<int N> struct X {};
12665 f(X<5>(), 5l); // error: template argument deduction fails
12668 The template parameter list of 'C' depends on the template type
12669 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
12670 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
12671 time that we deduce 'C'. */
12673 && !template_template_parm_bindings_ok_p
12674 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
12678 /* All is well so far. Now, check:
12682 When all template arguments have been deduced, all uses of
12683 template parameters in nondeduced contexts are replaced with
12684 the corresponding deduced argument values. If the
12685 substitution results in an invalid type, as described above,
12686 type deduction fails. */
12688 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
12689 if (substed == error_mark_node)
12692 /* If we're looking for an exact match, check that what we got
12693 is indeed an exact match. It might not be if some template
12694 parameters are used in non-deduced contexts. */
12695 if (strict == DEDUCE_EXACT)
12700 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
12702 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
12703 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
12704 if (!same_type_p (args[i], TREE_VALUE (sarg)))
12712 /* Adjust types before performing type deduction, as described in
12713 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
12714 sections are symmetric. PARM is the type of a function parameter
12715 or the return type of the conversion function. ARG is the type of
12716 the argument passed to the call, or the type of the value
12717 initialized with the result of the conversion function.
12718 ARG_EXPR is the original argument expression, which may be null. */
12721 maybe_adjust_types_for_deduction (unification_kind_t strict,
12735 /* Swap PARM and ARG throughout the remainder of this
12736 function; the handling is precisely symmetric since PARM
12737 will initialize ARG rather than vice versa. */
12745 /* There is nothing to do in this case. */
12749 gcc_unreachable ();
12752 if (TREE_CODE (*parm) != REFERENCE_TYPE)
12754 /* [temp.deduct.call]
12756 If P is not a reference type:
12758 --If A is an array type, the pointer type produced by the
12759 array-to-pointer standard conversion (_conv.array_) is
12760 used in place of A for type deduction; otherwise,
12762 --If A is a function type, the pointer type produced by
12763 the function-to-pointer standard conversion
12764 (_conv.func_) is used in place of A for type deduction;
12767 --If A is a cv-qualified type, the top level
12768 cv-qualifiers of A's type are ignored for type
12770 if (TREE_CODE (*arg) == ARRAY_TYPE)
12771 *arg = build_pointer_type (TREE_TYPE (*arg));
12772 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
12773 *arg = build_pointer_type (*arg);
12775 *arg = TYPE_MAIN_VARIANT (*arg);
12778 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
12779 of the form T&&, where T is a template parameter, and the argument
12780 is an lvalue, T is deduced as A& */
12781 if (TREE_CODE (*parm) == REFERENCE_TYPE
12782 && TYPE_REF_IS_RVALUE (*parm)
12783 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
12784 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
12785 && arg_expr && real_lvalue_p (arg_expr))
12786 *arg = build_reference_type (*arg);
12788 /* [temp.deduct.call]
12790 If P is a cv-qualified type, the top level cv-qualifiers
12791 of P's type are ignored for type deduction. If P is a
12792 reference type, the type referred to by P is used for
12794 *parm = TYPE_MAIN_VARIANT (*parm);
12795 if (TREE_CODE (*parm) == REFERENCE_TYPE)
12797 *parm = TREE_TYPE (*parm);
12798 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
12801 /* DR 322. For conversion deduction, remove a reference type on parm
12802 too (which has been swapped into ARG). */
12803 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
12804 *arg = TREE_TYPE (*arg);
12809 /* Most parms like fn_type_unification.
12811 If SUBR is 1, we're being called recursively (to unify the
12812 arguments of a function or method parameter of a function
12816 type_unification_real (tree tparms,
12820 unsigned int xnargs,
12822 unification_kind_t strict,
12825 tree parm, arg, arg_expr;
12827 int ntparms = TREE_VEC_LENGTH (tparms);
12829 int saw_undeduced = 0;
12832 unsigned int nargs;
12835 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
12836 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
12837 gcc_assert (ntparms > 0);
12842 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
12843 | UNIFY_ALLOW_DERIVED);
12847 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
12851 sub_strict = UNIFY_ALLOW_NONE;
12855 gcc_unreachable ();
12864 while (parms && parms != void_list_node
12867 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
12870 parm = TREE_VALUE (parms);
12871 parms = TREE_CHAIN (parms);
12876 if (arg == error_mark_node)
12878 if (arg == unknown_type_node)
12879 /* We can't deduce anything from this, but we might get all the
12880 template args from other function args. */
12883 /* Conversions will be performed on a function argument that
12884 corresponds with a function parameter that contains only
12885 non-deducible template parameters and explicitly specified
12886 template parameters. */
12887 if (!uses_template_parms (parm))
12892 type = TREE_TYPE (arg);
12896 if (same_type_p (parm, type))
12898 if (strict != DEDUCE_EXACT
12899 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
12908 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
12909 if (type_unknown_p (arg))
12911 /* [temp.deduct.type]
12913 A template-argument can be deduced from a pointer to
12914 function or pointer to member function argument if
12915 the set of overloaded functions does not contain
12916 function templates and at most one of a set of
12917 overloaded functions provides a unique match. */
12918 if (resolve_overloaded_unification
12919 (tparms, targs, parm, arg, strict, sub_strict))
12925 arg = unlowered_expr_type (arg);
12926 if (arg == error_mark_node)
12931 int arg_strict = sub_strict;
12934 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
12937 if (arg == init_list_type_node && arg_expr)
12939 if (unify (tparms, targs, parm, arg, arg_strict))
12946 && parms != void_list_node
12947 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
12949 /* Unify the remaining arguments with the pack expansion type. */
12951 tree parmvec = make_tree_vec (1);
12953 /* Allocate a TREE_VEC and copy in all of the arguments */
12954 argvec = make_tree_vec (nargs - ia);
12955 for (i = 0; ia < nargs; ++ia, ++i)
12956 TREE_VEC_ELT (argvec, i) = args[ia];
12958 /* Copy the parameter into parmvec. */
12959 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
12960 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
12961 /*call_args_p=*/true, /*subr=*/subr))
12964 /* Advance to the end of the list of parameters. */
12965 parms = TREE_CHAIN (parms);
12968 /* Fail if we've reached the end of the parm list, and more args
12969 are present, and the parm list isn't variadic. */
12970 if (ia < nargs && parms == void_list_node)
12972 /* Fail if parms are left and they don't have default values. */
12973 if (parms && parms != void_list_node
12974 && TREE_PURPOSE (parms) == NULL_TREE)
12978 for (i = 0; i < ntparms; i++)
12979 if (!TREE_VEC_ELT (targs, i))
12983 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
12986 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12988 /* If this is an undeduced nontype parameter that depends on
12989 a type parameter, try another pass; its type may have been
12990 deduced from a later argument than the one from which
12991 this parameter can be deduced. */
12992 if (TREE_CODE (tparm) == PARM_DECL
12993 && uses_template_parms (TREE_TYPE (tparm))
12994 && !saw_undeduced++)
12997 /* Core issue #226 (C++0x) [temp.deduct]:
12999 If a template argument has not been deduced, its
13000 default template argument, if any, is used.
13002 When we are in C++98 mode, TREE_PURPOSE will either
13003 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13004 to explicitly check cxx_dialect here. */
13005 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
13007 tree arg = tsubst_template_arg
13008 (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)),
13009 targs, tf_none, NULL_TREE);
13010 if (arg == error_mark_node)
13014 TREE_VEC_ELT (targs, i) = arg;
13019 /* If the type parameter is a parameter pack, then it will
13020 be deduced to an empty parameter pack. */
13021 if (template_parameter_pack_p (tparm))
13025 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
13027 arg = make_node (NONTYPE_ARGUMENT_PACK);
13028 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
13029 TREE_CONSTANT (arg) = 1;
13032 arg = make_node (TYPE_ARGUMENT_PACK);
13034 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
13036 TREE_VEC_ELT (targs, i) = arg;
13046 /* Subroutine of type_unification_real. Args are like the variables
13047 at the call site. ARG is an overloaded function (or template-id);
13048 we try deducing template args from each of the overloads, and if
13049 only one succeeds, we go with that. Modifies TARGS and returns
13050 true on success. */
13053 resolve_overloaded_unification (tree tparms,
13057 unification_kind_t strict,
13060 tree tempargs = copy_node (targs);
13062 tree goodfn = NULL_TREE;
13065 if (TREE_CODE (arg) == ADDR_EXPR)
13067 arg = TREE_OPERAND (arg, 0);
13073 if (TREE_CODE (arg) == COMPONENT_REF)
13074 /* Handle `&x' where `x' is some static or non-static member
13076 arg = TREE_OPERAND (arg, 1);
13078 if (TREE_CODE (arg) == OFFSET_REF)
13079 arg = TREE_OPERAND (arg, 1);
13081 /* Strip baselink information. */
13082 if (BASELINK_P (arg))
13083 arg = BASELINK_FUNCTIONS (arg);
13085 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
13087 /* If we got some explicit template args, we need to plug them into
13088 the affected templates before we try to unify, in case the
13089 explicit args will completely resolve the templates in question. */
13091 tree expl_subargs = TREE_OPERAND (arg, 1);
13092 arg = TREE_OPERAND (arg, 0);
13094 for (; arg; arg = OVL_NEXT (arg))
13096 tree fn = OVL_CURRENT (arg);
13097 tree subargs, elem;
13099 if (TREE_CODE (fn) != TEMPLATE_DECL)
13102 ++processing_template_decl;
13103 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13104 expl_subargs, /*check_ret=*/false);
13107 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
13108 if (try_one_overload (tparms, targs, tempargs, parm,
13109 elem, strict, sub_strict, addr_p)
13110 && (!goodfn || !decls_match (goodfn, elem)))
13116 --processing_template_decl;
13119 else if (TREE_CODE (arg) != OVERLOAD
13120 && TREE_CODE (arg) != FUNCTION_DECL)
13121 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13122 -- but the deduction does not succeed because the expression is
13123 not just the function on its own. */
13126 for (; arg; arg = OVL_NEXT (arg))
13127 if (try_one_overload (tparms, targs, tempargs, parm,
13128 TREE_TYPE (OVL_CURRENT (arg)),
13129 strict, sub_strict, addr_p)
13130 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
13132 goodfn = OVL_CURRENT (arg);
13136 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13137 to function or pointer to member function argument if the set of
13138 overloaded functions does not contain function templates and at most
13139 one of a set of overloaded functions provides a unique match.
13141 So if we found multiple possibilities, we return success but don't
13142 deduce anything. */
13146 int i = TREE_VEC_LENGTH (targs);
13148 if (TREE_VEC_ELT (tempargs, i))
13149 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
13157 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13158 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13159 different overloads deduce different arguments for a given parm.
13160 ADDR_P is true if the expression for which deduction is being
13161 performed was of the form "& fn" rather than simply "fn".
13163 Returns 1 on success. */
13166 try_one_overload (tree tparms,
13171 unification_kind_t strict,
13179 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13180 to function or pointer to member function argument if the set of
13181 overloaded functions does not contain function templates and at most
13182 one of a set of overloaded functions provides a unique match.
13184 So if this is a template, just return success. */
13186 if (uses_template_parms (arg))
13189 if (TREE_CODE (arg) == METHOD_TYPE)
13190 arg = build_ptrmemfunc_type (build_pointer_type (arg));
13192 arg = build_pointer_type (arg);
13194 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
13196 /* We don't copy orig_targs for this because if we have already deduced
13197 some template args from previous args, unify would complain when we
13198 try to deduce a template parameter for the same argument, even though
13199 there isn't really a conflict. */
13200 nargs = TREE_VEC_LENGTH (targs);
13201 tempargs = make_tree_vec (nargs);
13203 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
13206 /* First make sure we didn't deduce anything that conflicts with
13207 explicitly specified args. */
13208 for (i = nargs; i--; )
13210 tree elt = TREE_VEC_ELT (tempargs, i);
13211 tree oldelt = TREE_VEC_ELT (orig_targs, i);
13215 else if (uses_template_parms (elt))
13216 /* Since we're unifying against ourselves, we will fill in
13217 template args used in the function parm list with our own
13218 template parms. Discard them. */
13219 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
13220 else if (oldelt && !template_args_equal (oldelt, elt))
13224 for (i = nargs; i--; )
13226 tree elt = TREE_VEC_ELT (tempargs, i);
13229 TREE_VEC_ELT (targs, i) = elt;
13235 /* PARM is a template class (perhaps with unbound template
13236 parameters). ARG is a fully instantiated type. If ARG can be
13237 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13238 TARGS are as for unify. */
13241 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
13243 tree copy_of_targs;
13245 if (!CLASSTYPE_TEMPLATE_INFO (arg)
13246 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
13247 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
13250 /* We need to make a new template argument vector for the call to
13251 unify. If we used TARGS, we'd clutter it up with the result of
13252 the attempted unification, even if this class didn't work out.
13253 We also don't want to commit ourselves to all the unifications
13254 we've already done, since unification is supposed to be done on
13255 an argument-by-argument basis. In other words, consider the
13256 following pathological case:
13258 template <int I, int J, int K>
13261 template <int I, int J>
13262 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
13264 template <int I, int J, int K>
13265 void f(S<I, J, K>, S<I, I, I>);
13274 Now, by the time we consider the unification involving `s2', we
13275 already know that we must have `f<0, 0, 0>'. But, even though
13276 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
13277 because there are two ways to unify base classes of S<0, 1, 2>
13278 with S<I, I, I>. If we kept the already deduced knowledge, we
13279 would reject the possibility I=1. */
13280 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
13282 /* If unification failed, we're done. */
13283 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
13284 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
13290 /* Given a template type PARM and a class type ARG, find the unique
13291 base type in ARG that is an instance of PARM. We do not examine
13292 ARG itself; only its base-classes. If there is not exactly one
13293 appropriate base class, return NULL_TREE. PARM may be the type of
13294 a partial specialization, as well as a plain template type. Used
13298 get_template_base (tree tparms, tree targs, tree parm, tree arg)
13300 tree rval = NULL_TREE;
13303 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
13305 binfo = TYPE_BINFO (complete_type (arg));
13307 /* The type could not be completed. */
13310 /* Walk in inheritance graph order. The search order is not
13311 important, and this avoids multiple walks of virtual bases. */
13312 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
13314 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
13318 /* If there is more than one satisfactory baseclass, then:
13322 If they yield more than one possible deduced A, the type
13326 if (rval && !same_type_p (r, rval))
13336 /* Returns the level of DECL, which declares a template parameter. */
13339 template_decl_level (tree decl)
13341 switch (TREE_CODE (decl))
13344 case TEMPLATE_DECL:
13345 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
13348 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
13351 gcc_unreachable ();
13356 /* Decide whether ARG can be unified with PARM, considering only the
13357 cv-qualifiers of each type, given STRICT as documented for unify.
13358 Returns nonzero iff the unification is OK on that basis. */
13361 check_cv_quals_for_unify (int strict, tree arg, tree parm)
13363 int arg_quals = cp_type_quals (arg);
13364 int parm_quals = cp_type_quals (parm);
13366 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13367 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
13369 /* Although a CVR qualifier is ignored when being applied to a
13370 substituted template parameter ([8.3.2]/1 for example), that
13371 does not apply during deduction [14.8.2.4]/1, (even though
13372 that is not explicitly mentioned, [14.8.2.4]/9 indicates
13373 this). Except when we're allowing additional CV qualifiers
13374 at the outer level [14.8.2.1]/3,1st bullet. */
13375 if ((TREE_CODE (arg) == REFERENCE_TYPE
13376 || TREE_CODE (arg) == FUNCTION_TYPE
13377 || TREE_CODE (arg) == METHOD_TYPE)
13378 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
13381 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
13382 && (parm_quals & TYPE_QUAL_RESTRICT))
13386 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
13387 && (arg_quals & parm_quals) != parm_quals)
13390 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
13391 && (parm_quals & arg_quals) != arg_quals)
13397 /* Determines the LEVEL and INDEX for the template parameter PARM. */
13399 template_parm_level_and_index (tree parm, int* level, int* index)
13401 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13402 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13403 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13405 *index = TEMPLATE_TYPE_IDX (parm);
13406 *level = TEMPLATE_TYPE_LEVEL (parm);
13410 *index = TEMPLATE_PARM_IDX (parm);
13411 *level = TEMPLATE_PARM_LEVEL (parm);
13415 /* Unifies the remaining arguments in PACKED_ARGS with the pack
13416 expansion at the end of PACKED_PARMS. Returns 0 if the type
13417 deduction succeeds, 1 otherwise. STRICT is the same as in
13418 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
13419 call argument list. We'll need to adjust the arguments to make them
13420 types. SUBR tells us if this is from a recursive call to
13421 type_unification_real. */
13423 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
13424 tree packed_args, int strict, bool call_args_p,
13428 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
13429 tree pattern = PACK_EXPANSION_PATTERN (parm);
13430 tree pack, packs = NULL_TREE;
13431 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
13432 int len = TREE_VEC_LENGTH (packed_args);
13434 /* Determine the parameter packs we will be deducing from the
13435 pattern, and record their current deductions. */
13436 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
13437 pack; pack = TREE_CHAIN (pack))
13439 tree parm_pack = TREE_VALUE (pack);
13442 /* Determine the index and level of this parameter pack. */
13443 template_parm_level_and_index (parm_pack, &level, &idx);
13445 /* Keep track of the parameter packs and their corresponding
13447 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
13448 TREE_TYPE (packs) = make_tree_vec (len - start);
13451 /* Loop through all of the arguments that have not yet been
13452 unified and unify each with the pattern. */
13453 for (i = start; i < len; i++)
13455 tree parm = pattern;
13457 /* For each parameter pack, clear out the deduced value so that
13458 we can deduce it again. */
13459 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13462 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13464 TMPL_ARG (targs, level, idx) = NULL_TREE;
13467 /* Unify the pattern with the current argument. */
13469 tree arg = TREE_VEC_ELT (packed_args, i);
13470 tree arg_expr = NULL_TREE;
13471 int arg_strict = strict;
13472 bool skip_arg_p = false;
13478 /* This mirrors what we do in type_unification_real. */
13482 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
13483 | UNIFY_ALLOW_MORE_CV_QUAL
13484 | UNIFY_ALLOW_DERIVED);
13488 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13492 sub_strict = UNIFY_ALLOW_NONE;
13496 gcc_unreachable ();
13501 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
13502 if (type_unknown_p (arg))
13504 /* [temp.deduct.type] A template-argument can be
13505 deduced from a pointer to function or pointer
13506 to member function argument if the set of
13507 overloaded functions does not contain function
13508 templates and at most one of a set of
13509 overloaded functions provides a unique
13512 if (resolve_overloaded_unification
13513 (tparms, targs, parm, arg,
13514 (unification_kind_t) strict,
13524 arg = unlowered_expr_type (arg);
13525 if (arg == error_mark_node)
13530 arg_strict = sub_strict;
13534 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
13535 &parm, &arg, arg_expr);
13540 if (unify (tparms, targs, parm, arg, arg_strict))
13545 /* For each parameter pack, collect the deduced value. */
13546 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13549 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13551 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
13552 TMPL_ARG (targs, level, idx);
13556 /* Verify that the results of unification with the parameter packs
13557 produce results consistent with what we've seen before, and make
13558 the deduced argument packs available. */
13559 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13561 tree old_pack = TREE_VALUE (pack);
13562 tree new_args = TREE_TYPE (pack);
13563 int i, len = TREE_VEC_LENGTH (new_args);
13564 bool nondeduced_p = false;
13566 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
13567 actually deduce anything. */
13568 for (i = 0; i < len && !nondeduced_p; ++i)
13569 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
13570 nondeduced_p = true;
13574 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
13576 /* Prepend the explicit arguments onto NEW_ARGS. */
13577 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
13578 tree old_args = new_args;
13579 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
13580 int len = explicit_len + TREE_VEC_LENGTH (old_args);
13582 /* Copy the explicit arguments. */
13583 new_args = make_tree_vec (len);
13584 for (i = 0; i < explicit_len; i++)
13585 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
13587 /* Copy the deduced arguments. */
13588 for (; i < len; i++)
13589 TREE_VEC_ELT (new_args, i) =
13590 TREE_VEC_ELT (old_args, i - explicit_len);
13598 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13600 /* Build the deduced *_ARGUMENT_PACK. */
13601 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
13603 result = make_node (NONTYPE_ARGUMENT_PACK);
13604 TREE_TYPE (result) =
13605 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
13606 TREE_CONSTANT (result) = 1;
13609 result = make_node (TYPE_ARGUMENT_PACK);
13611 SET_ARGUMENT_PACK_ARGS (result, new_args);
13613 /* Note the deduced argument packs for this parameter
13615 TMPL_ARG (targs, level, idx) = result;
13617 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
13618 && (ARGUMENT_PACK_ARGS (old_pack)
13619 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
13621 /* We only had the explicitly-provided arguments before, but
13622 now we have a complete set of arguments. */
13624 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
13625 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13627 /* Keep the original deduced argument pack. */
13628 TMPL_ARG (targs, level, idx) = old_pack;
13630 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
13631 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
13632 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
13634 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
13636 /* Inconsistent unification of this parameter pack. */
13642 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13644 /* Keep the original deduced argument pack. */
13645 TMPL_ARG (targs, level, idx) = old_pack;
13652 /* Deduce the value of template parameters. TPARMS is the (innermost)
13653 set of template parameters to a template. TARGS is the bindings
13654 for those template parameters, as determined thus far; TARGS may
13655 include template arguments for outer levels of template parameters
13656 as well. PARM is a parameter to a template function, or a
13657 subcomponent of that parameter; ARG is the corresponding argument.
13658 This function attempts to match PARM with ARG in a manner
13659 consistent with the existing assignments in TARGS. If more values
13660 are deduced, then TARGS is updated.
13662 Returns 0 if the type deduction succeeds, 1 otherwise. The
13663 parameter STRICT is a bitwise or of the following flags:
13666 Require an exact match between PARM and ARG.
13667 UNIFY_ALLOW_MORE_CV_QUAL:
13668 Allow the deduced ARG to be more cv-qualified (by qualification
13669 conversion) than ARG.
13670 UNIFY_ALLOW_LESS_CV_QUAL:
13671 Allow the deduced ARG to be less cv-qualified than ARG.
13672 UNIFY_ALLOW_DERIVED:
13673 Allow the deduced ARG to be a template base class of ARG,
13674 or a pointer to a template base class of the type pointed to by
13676 UNIFY_ALLOW_INTEGER:
13677 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
13678 case for more information.
13679 UNIFY_ALLOW_OUTER_LEVEL:
13680 This is the outermost level of a deduction. Used to determine validity
13681 of qualification conversions. A valid qualification conversion must
13682 have const qualified pointers leading up to the inner type which
13683 requires additional CV quals, except at the outer level, where const
13684 is not required [conv.qual]. It would be normal to set this flag in
13685 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
13686 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
13687 This is the outermost level of a deduction, and PARM can be more CV
13688 qualified at this point.
13689 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
13690 This is the outermost level of a deduction, and PARM can be less CV
13691 qualified at this point. */
13694 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
13699 int strict_in = strict;
13701 /* I don't think this will do the right thing with respect to types.
13702 But the only case I've seen it in so far has been array bounds, where
13703 signedness is the only information lost, and I think that will be
13705 while (TREE_CODE (parm) == NOP_EXPR)
13706 parm = TREE_OPERAND (parm, 0);
13708 if (arg == error_mark_node)
13710 if (arg == unknown_type_node
13711 || arg == init_list_type_node)
13712 /* We can't deduce anything from this, but we might get all the
13713 template args from other function args. */
13716 /* If PARM uses template parameters, then we can't bail out here,
13717 even if ARG == PARM, since we won't record unifications for the
13718 template parameters. We might need them if we're trying to
13719 figure out which of two things is more specialized. */
13720 if (arg == parm && !uses_template_parms (parm))
13723 /* Handle init lists early, so the rest of the function can assume
13724 we're dealing with a type. */
13725 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
13730 if (!is_std_init_list (parm))
13731 /* We can only deduce from an initializer list argument if the
13732 parameter is std::initializer_list; otherwise this is a
13733 non-deduced context. */
13736 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
13738 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
13740 int elt_strict = strict;
13741 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
13743 tree type = TREE_TYPE (elt);
13744 /* It should only be possible to get here for a call. */
13745 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
13746 elt_strict |= maybe_adjust_types_for_deduction
13747 (DEDUCE_CALL, &elttype, &type, elt);
13751 if (unify (tparms, targs, elttype, elt, elt_strict))
13757 /* Immediately reject some pairs that won't unify because of
13758 cv-qualification mismatches. */
13759 if (TREE_CODE (arg) == TREE_CODE (parm)
13761 /* It is the elements of the array which hold the cv quals of an array
13762 type, and the elements might be template type parms. We'll check
13763 when we recurse. */
13764 && TREE_CODE (arg) != ARRAY_TYPE
13765 /* We check the cv-qualifiers when unifying with template type
13766 parameters below. We want to allow ARG `const T' to unify with
13767 PARM `T' for example, when computing which of two templates
13768 is more specialized, for example. */
13769 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
13770 && !check_cv_quals_for_unify (strict_in, arg, parm))
13773 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
13774 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
13775 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
13776 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
13777 strict &= ~UNIFY_ALLOW_DERIVED;
13778 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13779 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
13781 switch (TREE_CODE (parm))
13783 case TYPENAME_TYPE:
13785 case UNBOUND_CLASS_TEMPLATE:
13786 /* In a type which contains a nested-name-specifier, template
13787 argument values cannot be deduced for template parameters used
13788 within the nested-name-specifier. */
13791 case TEMPLATE_TYPE_PARM:
13792 case TEMPLATE_TEMPLATE_PARM:
13793 case BOUND_TEMPLATE_TEMPLATE_PARM:
13794 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
13795 if (tparm == error_mark_node)
13798 if (TEMPLATE_TYPE_LEVEL (parm)
13799 != template_decl_level (tparm))
13800 /* The PARM is not one we're trying to unify. Just check
13801 to see if it matches ARG. */
13802 return (TREE_CODE (arg) == TREE_CODE (parm)
13803 && same_type_p (parm, arg)) ? 0 : 1;
13804 idx = TEMPLATE_TYPE_IDX (parm);
13805 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
13806 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
13808 /* Check for mixed types and values. */
13809 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13810 && TREE_CODE (tparm) != TYPE_DECL)
13811 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13812 && TREE_CODE (tparm) != TEMPLATE_DECL))
13815 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13817 /* ARG must be constructed from a template class or a template
13818 template parameter. */
13819 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
13820 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
13824 tree parmvec = TYPE_TI_ARGS (parm);
13825 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
13827 = DECL_INNERMOST_TEMPLATE_PARMS
13828 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
13830 int parm_variadic_p = 0;
13832 /* The resolution to DR150 makes clear that default
13833 arguments for an N-argument may not be used to bind T
13834 to a template template parameter with fewer than N
13835 parameters. It is not safe to permit the binding of
13836 default arguments as an extension, as that may change
13837 the meaning of a conforming program. Consider:
13839 struct Dense { static const unsigned int dim = 1; };
13841 template <template <typename> class View,
13843 void operator+(float, View<Block> const&);
13845 template <typename Block,
13846 unsigned int Dim = Block::dim>
13847 struct Lvalue_proxy { operator float() const; };
13851 Lvalue_proxy<Dense> p;
13856 Here, if Lvalue_proxy is permitted to bind to View, then
13857 the global operator+ will be used; if they are not, the
13858 Lvalue_proxy will be converted to float. */
13859 if (coerce_template_parms (parm_parms,
13861 TYPE_TI_TEMPLATE (parm),
13863 /*require_all_args=*/true,
13864 /*use_default_args=*/false)
13865 == error_mark_node)
13868 /* Deduce arguments T, i from TT<T> or TT<i>.
13869 We check each element of PARMVEC and ARGVEC individually
13870 rather than the whole TREE_VEC since they can have
13871 different number of elements. */
13873 parmvec = expand_template_argument_pack (parmvec);
13874 argvec = expand_template_argument_pack (argvec);
13876 len = TREE_VEC_LENGTH (parmvec);
13878 /* Check if the parameters end in a pack, making them
13881 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
13882 parm_variadic_p = 1;
13884 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
13887 for (i = 0; i < len - parm_variadic_p; ++i)
13889 if (unify (tparms, targs,
13890 TREE_VEC_ELT (parmvec, i),
13891 TREE_VEC_ELT (argvec, i),
13896 if (parm_variadic_p
13897 && unify_pack_expansion (tparms, targs,
13900 /*call_args_p=*/false,
13904 arg = TYPE_TI_TEMPLATE (arg);
13906 /* Fall through to deduce template name. */
13909 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13910 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13912 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
13914 /* Simple cases: Value already set, does match or doesn't. */
13915 if (targ != NULL_TREE && template_args_equal (targ, arg))
13922 /* If PARM is `const T' and ARG is only `int', we don't have
13923 a match unless we are allowing additional qualification.
13924 If ARG is `const int' and PARM is just `T' that's OK;
13925 that binds `const int' to `T'. */
13926 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
13930 /* Consider the case where ARG is `const volatile int' and
13931 PARM is `const T'. Then, T should be `volatile int'. */
13932 arg = cp_build_qualified_type_real
13933 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
13934 if (arg == error_mark_node)
13937 /* Simple cases: Value already set, does match or doesn't. */
13938 if (targ != NULL_TREE && same_type_p (targ, arg))
13943 /* Make sure that ARG is not a variable-sized array. (Note
13944 that were talking about variable-sized arrays (like
13945 `int[n]'), rather than arrays of unknown size (like
13946 `int[]').) We'll get very confused by such a type since
13947 the bound of the array will not be computable in an
13948 instantiation. Besides, such types are not allowed in
13949 ISO C++, so we can do as we please here. */
13950 if (variably_modified_type_p (arg, NULL_TREE))
13953 /* Strip typedefs as in convert_template_argument. */
13954 arg = strip_typedefs (arg);
13957 /* If ARG is a parameter pack or an expansion, we cannot unify
13958 against it unless PARM is also a parameter pack. */
13959 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
13960 && !template_parameter_pack_p (parm))
13963 /* If the argument deduction results is a METHOD_TYPE,
13964 then there is a problem.
13965 METHOD_TYPE doesn't map to any real C++ type the result of
13966 the deduction can not be of that type. */
13967 if (TREE_CODE (arg) == METHOD_TYPE)
13970 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
13973 case TEMPLATE_PARM_INDEX:
13974 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
13975 if (tparm == error_mark_node)
13978 if (TEMPLATE_PARM_LEVEL (parm)
13979 != template_decl_level (tparm))
13980 /* The PARM is not one we're trying to unify. Just check
13981 to see if it matches ARG. */
13982 return !(TREE_CODE (arg) == TREE_CODE (parm)
13983 && cp_tree_equal (parm, arg));
13985 idx = TEMPLATE_PARM_IDX (parm);
13986 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
13989 return !cp_tree_equal (targ, arg);
13991 /* [temp.deduct.type] If, in the declaration of a function template
13992 with a non-type template-parameter, the non-type
13993 template-parameter is used in an expression in the function
13994 parameter-list and, if the corresponding template-argument is
13995 deduced, the template-argument type shall match the type of the
13996 template-parameter exactly, except that a template-argument
13997 deduced from an array bound may be of any integral type.
13998 The non-type parameter might use already deduced type parameters. */
13999 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
14000 if (!TREE_TYPE (arg))
14001 /* Template-parameter dependent expression. Just accept it for now.
14002 It will later be processed in convert_template_argument. */
14004 else if (same_type_p (TREE_TYPE (arg), tparm))
14006 else if ((strict & UNIFY_ALLOW_INTEGER)
14007 && (TREE_CODE (tparm) == INTEGER_TYPE
14008 || TREE_CODE (tparm) == BOOLEAN_TYPE))
14009 /* Convert the ARG to the type of PARM; the deduced non-type
14010 template argument must exactly match the types of the
14011 corresponding parameter. */
14012 arg = fold (build_nop (tparm, arg));
14013 else if (uses_template_parms (tparm))
14014 /* We haven't deduced the type of this parameter yet. Try again
14020 /* If ARG is a parameter pack or an expansion, we cannot unify
14021 against it unless PARM is also a parameter pack. */
14022 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14023 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
14026 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14031 /* A pointer-to-member constant can be unified only with
14032 another constant. */
14033 if (TREE_CODE (arg) != PTRMEM_CST)
14036 /* Just unify the class member. It would be useless (and possibly
14037 wrong, depending on the strict flags) to unify also
14038 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14039 arg refer to the same variable, even if through different
14040 classes. For instance:
14042 struct A { int x; };
14045 Unification of &A::x and &B::x must succeed. */
14046 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
14047 PTRMEM_CST_MEMBER (arg), strict);
14052 if (TREE_CODE (arg) != POINTER_TYPE)
14055 /* [temp.deduct.call]
14057 A can be another pointer or pointer to member type that can
14058 be converted to the deduced A via a qualification
14059 conversion (_conv.qual_).
14061 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14062 This will allow for additional cv-qualification of the
14063 pointed-to types if appropriate. */
14065 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
14066 /* The derived-to-base conversion only persists through one
14067 level of pointers. */
14068 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
14070 return unify (tparms, targs, TREE_TYPE (parm),
14071 TREE_TYPE (arg), strict);
14074 case REFERENCE_TYPE:
14075 if (TREE_CODE (arg) != REFERENCE_TYPE)
14077 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14078 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14081 if (TREE_CODE (arg) != ARRAY_TYPE)
14083 if ((TYPE_DOMAIN (parm) == NULL_TREE)
14084 != (TYPE_DOMAIN (arg) == NULL_TREE))
14086 if (TYPE_DOMAIN (parm) != NULL_TREE)
14093 /* Our representation of array types uses "N - 1" as the
14094 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14095 not an integer constant. We cannot unify arbitrarily
14096 complex expressions, so we eliminate the MINUS_EXPRs
14098 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
14099 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
14102 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
14103 parm_max = TREE_OPERAND (parm_max, 0);
14105 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
14106 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
14109 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14110 trying to unify the type of a variable with the type
14111 of a template parameter. For example:
14113 template <unsigned int N>
14114 void f (char (&) [N]);
14121 Here, the type of the ARG will be "int [g(i)]", and
14122 may be a SAVE_EXPR, etc. */
14123 if (TREE_CODE (arg_max) != MINUS_EXPR)
14125 arg_max = TREE_OPERAND (arg_max, 0);
14128 /* If only one of the bounds used a MINUS_EXPR, compensate
14129 by adding one to the other bound. */
14130 if (parm_cst && !arg_cst)
14131 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
14135 else if (arg_cst && !parm_cst)
14136 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
14141 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
14144 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14145 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14152 case ENUMERAL_TYPE:
14154 if (TREE_CODE (arg) != TREE_CODE (parm))
14157 /* We have already checked cv-qualification at the top of the
14159 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
14162 /* As far as unification is concerned, this wins. Later checks
14163 will invalidate it if necessary. */
14166 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14167 /* Type INTEGER_CST can come from ordinary constant template args. */
14169 while (TREE_CODE (arg) == NOP_EXPR)
14170 arg = TREE_OPERAND (arg, 0);
14172 if (TREE_CODE (arg) != INTEGER_CST)
14174 return !tree_int_cst_equal (parm, arg);
14179 if (TREE_CODE (arg) != TREE_VEC)
14181 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
14183 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
14184 if (unify (tparms, targs,
14185 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
14193 if (TREE_CODE (arg) != TREE_CODE (parm))
14196 if (TYPE_PTRMEMFUNC_P (parm))
14198 if (!TYPE_PTRMEMFUNC_P (arg))
14201 return unify (tparms, targs,
14202 TYPE_PTRMEMFUNC_FN_TYPE (parm),
14203 TYPE_PTRMEMFUNC_FN_TYPE (arg),
14207 if (CLASSTYPE_TEMPLATE_INFO (parm))
14209 tree t = NULL_TREE;
14211 if (strict_in & UNIFY_ALLOW_DERIVED)
14213 /* First, we try to unify the PARM and ARG directly. */
14214 t = try_class_unification (tparms, targs,
14219 /* Fallback to the special case allowed in
14220 [temp.deduct.call]:
14222 If P is a class, and P has the form
14223 template-id, then A can be a derived class of
14224 the deduced A. Likewise, if P is a pointer to
14225 a class of the form template-id, A can be a
14226 pointer to a derived class pointed to by the
14228 t = get_template_base (tparms, targs, parm, arg);
14234 else if (CLASSTYPE_TEMPLATE_INFO (arg)
14235 && (CLASSTYPE_TI_TEMPLATE (parm)
14236 == CLASSTYPE_TI_TEMPLATE (arg)))
14237 /* Perhaps PARM is something like S<U> and ARG is S<int>.
14238 Then, we should unify `int' and `U'. */
14241 /* There's no chance of unification succeeding. */
14244 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
14245 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
14247 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
14252 case FUNCTION_TYPE:
14254 unsigned int nargs;
14259 if (TREE_CODE (arg) != TREE_CODE (parm))
14262 /* CV qualifications for methods can never be deduced, they must
14263 match exactly. We need to check them explicitly here,
14264 because type_unification_real treats them as any other
14265 cv-qualified parameter. */
14266 if (TREE_CODE (parm) == METHOD_TYPE
14267 && (!check_cv_quals_for_unify
14269 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
14270 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
14273 if (unify (tparms, targs, TREE_TYPE (parm),
14274 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
14277 nargs = list_length (TYPE_ARG_TYPES (arg));
14278 args = XALLOCAVEC (tree, nargs);
14279 for (a = TYPE_ARG_TYPES (arg), i = 0;
14280 a != NULL_TREE && a != void_list_node;
14281 a = TREE_CHAIN (a), ++i)
14282 args[i] = TREE_VALUE (a);
14285 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
14286 args, nargs, 1, DEDUCE_EXACT,
14291 /* Unify a pointer to member with a pointer to member function, which
14292 deduces the type of the member as a function type. */
14293 if (TYPE_PTRMEMFUNC_P (arg))
14297 cp_cv_quals cv_quals;
14299 /* Check top-level cv qualifiers */
14300 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
14303 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
14304 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
14307 /* Determine the type of the function we are unifying against. */
14308 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
14310 build_function_type (TREE_TYPE (method_type),
14311 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
14313 /* Extract the cv-qualifiers of the member function from the
14314 implicit object parameter and place them on the function
14315 type to be restored later. */
14317 cp_type_quals(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (method_type))));
14318 fntype = build_qualified_type (fntype, cv_quals);
14319 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
14322 if (TREE_CODE (arg) != OFFSET_TYPE)
14324 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
14325 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
14327 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14331 if (DECL_TEMPLATE_PARM_P (parm))
14332 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
14333 if (arg != integral_constant_value (parm))
14338 case TEMPLATE_DECL:
14339 /* Matched cases are handled by the ARG == PARM test above. */
14342 case TYPE_ARGUMENT_PACK:
14343 case NONTYPE_ARGUMENT_PACK:
14345 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
14346 tree packed_args = ARGUMENT_PACK_ARGS (arg);
14347 int i, len = TREE_VEC_LENGTH (packed_parms);
14348 int argslen = TREE_VEC_LENGTH (packed_args);
14349 int parm_variadic_p = 0;
14351 for (i = 0; i < len; ++i)
14353 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
14356 /* We can unify against something with a trailing
14358 parm_variadic_p = 1;
14360 /* Since there is something following the pack
14361 expansion, we cannot unify this template argument
14368 /* If we don't have enough arguments to satisfy the parameters
14369 (not counting the pack expression at the end), or we have
14370 too many arguments for a parameter list that doesn't end in
14371 a pack expression, we can't unify. */
14372 if (argslen < (len - parm_variadic_p)
14373 || (argslen > len && !parm_variadic_p))
14376 /* Unify all of the parameters that precede the (optional)
14377 pack expression. */
14378 for (i = 0; i < len - parm_variadic_p; ++i)
14380 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
14381 TREE_VEC_ELT (packed_args, i), strict))
14385 if (parm_variadic_p)
14386 return unify_pack_expansion (tparms, targs,
14387 packed_parms, packed_args,
14388 strict, /*call_args_p=*/false,
14396 case DECLTYPE_TYPE:
14397 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
14402 /* Unification fails if we hit an error node. */
14406 gcc_assert (EXPR_P (parm));
14408 /* We must be looking at an expression. This can happen with
14412 void foo(S<I>, S<I + 2>);
14414 This is a "nondeduced context":
14418 The nondeduced contexts are:
14420 --A type that is a template-id in which one or more of
14421 the template-arguments is an expression that references
14422 a template-parameter.
14424 In these cases, we assume deduction succeeded, but don't
14425 actually infer any unifications. */
14427 if (!uses_template_parms (parm)
14428 && !template_args_equal (parm, arg))
14435 /* Note that DECL can be defined in this translation unit, if
14439 mark_definable (tree decl)
14442 DECL_NOT_REALLY_EXTERN (decl) = 1;
14443 FOR_EACH_CLONE (clone, decl)
14444 DECL_NOT_REALLY_EXTERN (clone) = 1;
14447 /* Called if RESULT is explicitly instantiated, or is a member of an
14448 explicitly instantiated class. */
14451 mark_decl_instantiated (tree result, int extern_p)
14453 SET_DECL_EXPLICIT_INSTANTIATION (result);
14455 /* If this entity has already been written out, it's too late to
14456 make any modifications. */
14457 if (TREE_ASM_WRITTEN (result))
14460 if (TREE_CODE (result) != FUNCTION_DECL)
14461 /* The TREE_PUBLIC flag for function declarations will have been
14462 set correctly by tsubst. */
14463 TREE_PUBLIC (result) = 1;
14465 /* This might have been set by an earlier implicit instantiation. */
14466 DECL_COMDAT (result) = 0;
14469 DECL_NOT_REALLY_EXTERN (result) = 0;
14472 mark_definable (result);
14473 /* Always make artificials weak. */
14474 if (DECL_ARTIFICIAL (result) && flag_weak)
14475 comdat_linkage (result);
14476 /* For WIN32 we also want to put explicit instantiations in
14477 linkonce sections. */
14478 else if (TREE_PUBLIC (result))
14479 maybe_make_one_only (result);
14482 /* If EXTERN_P, then this function will not be emitted -- unless
14483 followed by an explicit instantiation, at which point its linkage
14484 will be adjusted. If !EXTERN_P, then this function will be
14485 emitted here. In neither circumstance do we want
14486 import_export_decl to adjust the linkage. */
14487 DECL_INTERFACE_KNOWN (result) = 1;
14490 /* Given two function templates PAT1 and PAT2, return:
14492 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
14493 -1 if PAT2 is more specialized than PAT1.
14494 0 if neither is more specialized.
14496 LEN indicates the number of parameters we should consider
14497 (defaulted parameters should not be considered).
14499 The 1998 std underspecified function template partial ordering, and
14500 DR214 addresses the issue. We take pairs of arguments, one from
14501 each of the templates, and deduce them against each other. One of
14502 the templates will be more specialized if all the *other*
14503 template's arguments deduce against its arguments and at least one
14504 of its arguments *does* *not* deduce against the other template's
14505 corresponding argument. Deduction is done as for class templates.
14506 The arguments used in deduction have reference and top level cv
14507 qualifiers removed. Iff both arguments were originally reference
14508 types *and* deduction succeeds in both directions, the template
14509 with the more cv-qualified argument wins for that pairing (if
14510 neither is more cv-qualified, they both are equal). Unlike regular
14511 deduction, after all the arguments have been deduced in this way,
14512 we do *not* verify the deduced template argument values can be
14513 substituted into non-deduced contexts, nor do we have to verify
14514 that all template arguments have been deduced. */
14517 more_specialized_fn (tree pat1, tree pat2, int len)
14519 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
14520 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
14521 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
14522 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
14523 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
14524 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
14525 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
14526 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
14530 /* Remove the this parameter from non-static member functions. If
14531 one is a non-static member function and the other is not a static
14532 member function, remove the first parameter from that function
14533 also. This situation occurs for operator functions where we
14534 locate both a member function (with this pointer) and non-member
14535 operator (with explicit first operand). */
14536 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
14538 len--; /* LEN is the number of significant arguments for DECL1 */
14539 args1 = TREE_CHAIN (args1);
14540 if (!DECL_STATIC_FUNCTION_P (decl2))
14541 args2 = TREE_CHAIN (args2);
14543 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
14545 args2 = TREE_CHAIN (args2);
14546 if (!DECL_STATIC_FUNCTION_P (decl1))
14549 args1 = TREE_CHAIN (args1);
14553 /* If only one is a conversion operator, they are unordered. */
14554 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
14557 /* Consider the return type for a conversion function */
14558 if (DECL_CONV_FN_P (decl1))
14560 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
14561 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
14565 processing_template_decl++;
14568 /* Stop when an ellipsis is seen. */
14569 && args1 != NULL_TREE && args2 != NULL_TREE)
14571 tree arg1 = TREE_VALUE (args1);
14572 tree arg2 = TREE_VALUE (args2);
14573 int deduce1, deduce2;
14577 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
14578 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14580 /* When both arguments are pack expansions, we need only
14581 unify the patterns themselves. */
14582 arg1 = PACK_EXPANSION_PATTERN (arg1);
14583 arg2 = PACK_EXPANSION_PATTERN (arg2);
14585 /* This is the last comparison we need to do. */
14589 if (TREE_CODE (arg1) == REFERENCE_TYPE)
14591 arg1 = TREE_TYPE (arg1);
14592 quals1 = cp_type_quals (arg1);
14595 if (TREE_CODE (arg2) == REFERENCE_TYPE)
14597 arg2 = TREE_TYPE (arg2);
14598 quals2 = cp_type_quals (arg2);
14601 if ((quals1 < 0) != (quals2 < 0))
14603 /* Only of the args is a reference, see if we should apply
14604 array/function pointer decay to it. This is not part of
14605 DR214, but is, IMHO, consistent with the deduction rules
14606 for the function call itself, and with our earlier
14607 implementation of the underspecified partial ordering
14608 rules. (nathan). */
14611 switch (TREE_CODE (arg1))
14614 arg1 = TREE_TYPE (arg1);
14616 case FUNCTION_TYPE:
14617 arg1 = build_pointer_type (arg1);
14626 switch (TREE_CODE (arg2))
14629 arg2 = TREE_TYPE (arg2);
14631 case FUNCTION_TYPE:
14632 arg2 = build_pointer_type (arg2);
14641 arg1 = TYPE_MAIN_VARIANT (arg1);
14642 arg2 = TYPE_MAIN_VARIANT (arg2);
14644 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
14646 int i, len2 = list_length (args2);
14647 tree parmvec = make_tree_vec (1);
14648 tree argvec = make_tree_vec (len2);
14651 /* Setup the parameter vector, which contains only ARG1. */
14652 TREE_VEC_ELT (parmvec, 0) = arg1;
14654 /* Setup the argument vector, which contains the remaining
14656 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
14657 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
14659 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
14660 argvec, UNIFY_ALLOW_NONE,
14661 /*call_args_p=*/false,
14664 /* We cannot deduce in the other direction, because ARG1 is
14665 a pack expansion but ARG2 is not. */
14668 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14670 int i, len1 = list_length (args1);
14671 tree parmvec = make_tree_vec (1);
14672 tree argvec = make_tree_vec (len1);
14675 /* Setup the parameter vector, which contains only ARG1. */
14676 TREE_VEC_ELT (parmvec, 0) = arg2;
14678 /* Setup the argument vector, which contains the remaining
14680 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
14681 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
14683 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
14684 argvec, UNIFY_ALLOW_NONE,
14685 /*call_args_p=*/false,
14688 /* We cannot deduce in the other direction, because ARG2 is
14689 a pack expansion but ARG1 is not.*/
14695 /* The normal case, where neither argument is a pack
14697 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
14698 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
14705 if (better1 < 0 && better2 < 0)
14706 /* We've failed to deduce something in either direction.
14707 These must be unordered. */
14710 if (deduce1 && deduce2 && quals1 >= 0 && quals2 >= 0)
14712 /* Deduces in both directions, see if quals can
14713 disambiguate. Pretend the worse one failed to deduce. */
14714 if ((quals1 & quals2) == quals2)
14716 if ((quals1 & quals2) == quals1)
14719 if (deduce1 && !deduce2 && !better2)
14721 if (deduce2 && !deduce1 && !better1)
14724 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
14725 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14726 /* We have already processed all of the arguments in our
14727 handing of the pack expansion type. */
14730 args1 = TREE_CHAIN (args1);
14731 args2 = TREE_CHAIN (args2);
14734 processing_template_decl--;
14736 /* All things being equal, if the next argument is a pack expansion
14737 for one function but not for the other, prefer the
14738 non-variadic function. */
14739 if ((better1 > 0) - (better2 > 0) == 0
14740 && args1 && TREE_VALUE (args1)
14741 && args2 && TREE_VALUE (args2))
14743 if (TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION)
14744 return TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION ? 0 : -1;
14745 else if (TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION)
14749 return (better1 > 0) - (better2 > 0);
14752 /* Determine which of two partial specializations is more specialized.
14754 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
14755 to the first partial specialization. The TREE_VALUE is the
14756 innermost set of template parameters for the partial
14757 specialization. PAT2 is similar, but for the second template.
14759 Return 1 if the first partial specialization is more specialized;
14760 -1 if the second is more specialized; 0 if neither is more
14763 See [temp.class.order] for information about determining which of
14764 two templates is more specialized. */
14767 more_specialized_class (tree pat1, tree pat2)
14772 bool any_deductions = false;
14774 tmpl1 = TREE_TYPE (pat1);
14775 tmpl2 = TREE_TYPE (pat2);
14777 /* Just like what happens for functions, if we are ordering between
14778 different class template specializations, we may encounter dependent
14779 types in the arguments, and we need our dependency check functions
14780 to behave correctly. */
14781 ++processing_template_decl;
14782 targs = get_class_bindings (TREE_VALUE (pat1),
14783 CLASSTYPE_TI_ARGS (tmpl1),
14784 CLASSTYPE_TI_ARGS (tmpl2));
14788 any_deductions = true;
14791 targs = get_class_bindings (TREE_VALUE (pat2),
14792 CLASSTYPE_TI_ARGS (tmpl2),
14793 CLASSTYPE_TI_ARGS (tmpl1));
14797 any_deductions = true;
14799 --processing_template_decl;
14801 /* In the case of a tie where at least one of the class templates
14802 has a parameter pack at the end, the template with the most
14803 non-packed parameters wins. */
14806 && (template_args_variadic_p (TREE_PURPOSE (pat1))
14807 || template_args_variadic_p (TREE_PURPOSE (pat2))))
14809 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
14810 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
14811 int len1 = TREE_VEC_LENGTH (args1);
14812 int len2 = TREE_VEC_LENGTH (args2);
14814 /* We don't count the pack expansion at the end. */
14815 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
14817 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
14822 else if (len1 < len2)
14829 /* Return the template arguments that will produce the function signature
14830 DECL from the function template FN, with the explicit template
14831 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
14832 also match. Return NULL_TREE if no satisfactory arguments could be
14836 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
14838 int ntparms = DECL_NTPARMS (fn);
14839 tree targs = make_tree_vec (ntparms);
14841 tree decl_arg_types;
14843 unsigned int nargs, ix;
14846 /* Substitute the explicit template arguments into the type of DECL.
14847 The call to fn_type_unification will handle substitution into the
14849 decl_type = TREE_TYPE (decl);
14850 if (explicit_args && uses_template_parms (decl_type))
14853 tree converted_args;
14855 if (DECL_TEMPLATE_INFO (decl))
14856 tmpl = DECL_TI_TEMPLATE (decl);
14858 /* We can get here for some invalid specializations. */
14862 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
14863 explicit_args, NULL_TREE,
14865 /*require_all_args=*/false,
14866 /*use_default_args=*/false);
14867 if (converted_args == error_mark_node)
14870 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
14871 if (decl_type == error_mark_node)
14875 /* Never do unification on the 'this' parameter. */
14876 decl_arg_types = skip_artificial_parms_for (decl,
14877 TYPE_ARG_TYPES (decl_type));
14879 nargs = list_length (decl_arg_types);
14880 args = XALLOCAVEC (tree, nargs);
14881 for (arg = decl_arg_types, ix = 0;
14882 arg != NULL_TREE && arg != void_list_node;
14883 arg = TREE_CHAIN (arg), ++ix)
14884 args[ix] = TREE_VALUE (arg);
14886 if (fn_type_unification (fn, explicit_args, targs,
14888 (check_rettype || DECL_CONV_FN_P (fn)
14889 ? TREE_TYPE (decl_type) : NULL_TREE),
14890 DEDUCE_EXACT, LOOKUP_NORMAL))
14896 /* Return the innermost template arguments that, when applied to a
14897 template specialization whose innermost template parameters are
14898 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
14901 For example, suppose we have:
14903 template <class T, class U> struct S {};
14904 template <class T> struct S<T*, int> {};
14906 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
14907 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
14908 int}. The resulting vector will be {double}, indicating that `T'
14909 is bound to `double'. */
14912 get_class_bindings (tree tparms, tree spec_args, tree args)
14914 int i, ntparms = TREE_VEC_LENGTH (tparms);
14916 tree innermost_deduced_args;
14918 innermost_deduced_args = make_tree_vec (ntparms);
14919 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
14921 deduced_args = copy_node (args);
14922 SET_TMPL_ARGS_LEVEL (deduced_args,
14923 TMPL_ARGS_DEPTH (deduced_args),
14924 innermost_deduced_args);
14927 deduced_args = innermost_deduced_args;
14929 if (unify (tparms, deduced_args,
14930 INNERMOST_TEMPLATE_ARGS (spec_args),
14931 INNERMOST_TEMPLATE_ARGS (args),
14935 for (i = 0; i < ntparms; ++i)
14936 if (! TREE_VEC_ELT (innermost_deduced_args, i))
14939 /* Verify that nondeduced template arguments agree with the type
14940 obtained from argument deduction.
14944 struct A { typedef int X; };
14945 template <class T, class U> struct C {};
14946 template <class T> struct C<T, typename T::X> {};
14948 Then with the instantiation `C<A, int>', we can deduce that
14949 `T' is `A' but unify () does not check whether `typename T::X'
14951 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
14952 if (spec_args == error_mark_node
14953 /* We only need to check the innermost arguments; the other
14954 arguments will always agree. */
14955 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
14956 INNERMOST_TEMPLATE_ARGS (args)))
14959 /* Now that we have bindings for all of the template arguments,
14960 ensure that the arguments deduced for the template template
14961 parameters have compatible template parameter lists. See the use
14962 of template_template_parm_bindings_ok_p in fn_type_unification
14963 for more information. */
14964 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
14967 return deduced_args;
14970 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
14971 Return the TREE_LIST node with the most specialized template, if
14972 any. If there is no most specialized template, the error_mark_node
14975 Note that this function does not look at, or modify, the
14976 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
14977 returned is one of the elements of INSTANTIATIONS, callers may
14978 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
14979 and retrieve it from the value returned. */
14982 most_specialized_instantiation (tree templates)
14986 ++processing_template_decl;
14989 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
14993 if (get_bindings (TREE_VALUE (champ),
14994 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
14995 NULL_TREE, /*check_ret=*/false))
14998 if (get_bindings (TREE_VALUE (fn),
14999 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15000 NULL_TREE, /*check_ret=*/false))
15007 /* Equally specialized, move to next function. If there
15008 is no next function, nothing's most specialized. */
15009 fn = TREE_CHAIN (fn);
15017 /* Now verify that champ is better than everything earlier in the
15018 instantiation list. */
15019 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
15020 if (get_bindings (TREE_VALUE (champ),
15021 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15022 NULL_TREE, /*check_ret=*/false)
15023 || !get_bindings (TREE_VALUE (fn),
15024 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15025 NULL_TREE, /*check_ret=*/false))
15031 processing_template_decl--;
15034 return error_mark_node;
15039 /* If DECL is a specialization of some template, return the most
15040 general such template. Otherwise, returns NULL_TREE.
15042 For example, given:
15044 template <class T> struct S { template <class U> void f(U); };
15046 if TMPL is `template <class U> void S<int>::f(U)' this will return
15047 the full template. This function will not trace past partial
15048 specializations, however. For example, given in addition:
15050 template <class T> struct S<T*> { template <class U> void f(U); };
15052 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15053 `template <class T> template <class U> S<T*>::f(U)'. */
15056 most_general_template (tree decl)
15058 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15059 an immediate specialization. */
15060 if (TREE_CODE (decl) == FUNCTION_DECL)
15062 if (DECL_TEMPLATE_INFO (decl)) {
15063 decl = DECL_TI_TEMPLATE (decl);
15065 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15066 template friend. */
15067 if (TREE_CODE (decl) != TEMPLATE_DECL)
15073 /* Look for more and more general templates. */
15074 while (DECL_TEMPLATE_INFO (decl))
15076 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15077 (See cp-tree.h for details.) */
15078 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
15081 if (CLASS_TYPE_P (TREE_TYPE (decl))
15082 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
15085 /* Stop if we run into an explicitly specialized class template. */
15086 if (!DECL_NAMESPACE_SCOPE_P (decl)
15087 && DECL_CONTEXT (decl)
15088 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
15091 decl = DECL_TI_TEMPLATE (decl);
15097 /* Return the most specialized of the class template partial
15098 specializations of TMPL which can produce TYPE, a specialization of
15099 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15100 a _TYPE node corresponding to the partial specialization, while the
15101 TREE_PURPOSE is the set of template arguments that must be
15102 substituted into the TREE_TYPE in order to generate TYPE.
15104 If the choice of partial specialization is ambiguous, a diagnostic
15105 is issued, and the error_mark_node is returned. If there are no
15106 partial specializations of TMPL matching TYPE, then NULL_TREE is
15110 most_specialized_class (tree type, tree tmpl)
15112 tree list = NULL_TREE;
15118 tree outer_args = NULL_TREE;
15120 tmpl = most_general_template (tmpl);
15121 args = CLASSTYPE_TI_ARGS (type);
15123 /* For determining which partial specialization to use, only the
15124 innermost args are interesting. */
15125 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15127 outer_args = strip_innermost_template_args (args, 1);
15128 args = INNERMOST_TEMPLATE_ARGS (args);
15131 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
15133 tree partial_spec_args;
15135 tree parms = TREE_VALUE (t);
15137 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
15142 ++processing_template_decl;
15144 /* Discard the outer levels of args, and then substitute in the
15145 template args from the enclosing class. */
15146 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
15147 partial_spec_args = tsubst_template_args
15148 (partial_spec_args, outer_args, tf_none, NULL_TREE);
15150 /* PARMS already refers to just the innermost parms, but the
15151 template parms in partial_spec_args had their levels lowered
15152 by tsubst, so we need to do the same for the parm list. We
15153 can't just tsubst the TREE_VEC itself, as tsubst wants to
15154 treat a TREE_VEC as an argument vector. */
15155 parms = copy_node (parms);
15156 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
15157 TREE_VEC_ELT (parms, i) =
15158 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
15160 --processing_template_decl;
15162 spec_args = get_class_bindings (parms,
15168 spec_args = add_to_template_args (outer_args, spec_args);
15169 list = tree_cons (spec_args, TREE_VALUE (t), list);
15170 TREE_TYPE (list) = TREE_TYPE (t);
15177 ambiguous_p = false;
15180 t = TREE_CHAIN (t);
15181 for (; t; t = TREE_CHAIN (t))
15183 fate = more_specialized_class (champ, t);
15190 t = TREE_CHAIN (t);
15193 ambiguous_p = true;
15202 for (t = list; t && t != champ; t = TREE_CHAIN (t))
15204 fate = more_specialized_class (champ, t);
15207 ambiguous_p = true;
15214 const char *str = "candidates are:";
15215 error ("ambiguous class template instantiation for %q#T", type);
15216 for (t = list; t; t = TREE_CHAIN (t))
15218 error ("%s %+#T", str, TREE_TYPE (t));
15221 return error_mark_node;
15227 /* Explicitly instantiate DECL. */
15230 do_decl_instantiation (tree decl, tree storage)
15232 tree result = NULL_TREE;
15235 if (!decl || decl == error_mark_node)
15236 /* An error occurred, for which grokdeclarator has already issued
15237 an appropriate message. */
15239 else if (! DECL_LANG_SPECIFIC (decl))
15241 error ("explicit instantiation of non-template %q#D", decl);
15244 else if (TREE_CODE (decl) == VAR_DECL)
15246 /* There is an asymmetry here in the way VAR_DECLs and
15247 FUNCTION_DECLs are handled by grokdeclarator. In the case of
15248 the latter, the DECL we get back will be marked as a
15249 template instantiation, and the appropriate
15250 DECL_TEMPLATE_INFO will be set up. This does not happen for
15251 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
15252 should handle VAR_DECLs as it currently handles
15254 if (!DECL_CLASS_SCOPE_P (decl))
15256 error ("%qD is not a static data member of a class template", decl);
15259 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
15260 if (!result || TREE_CODE (result) != VAR_DECL)
15262 error ("no matching template for %qD found", decl);
15265 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
15267 error ("type %qT for explicit instantiation %qD does not match "
15268 "declared type %qT", TREE_TYPE (result), decl,
15273 else if (TREE_CODE (decl) != FUNCTION_DECL)
15275 error ("explicit instantiation of %q#D", decl);
15281 /* Check for various error cases. Note that if the explicit
15282 instantiation is valid the RESULT will currently be marked as an
15283 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
15284 until we get here. */
15286 if (DECL_TEMPLATE_SPECIALIZATION (result))
15288 /* DR 259 [temp.spec].
15290 Both an explicit instantiation and a declaration of an explicit
15291 specialization shall not appear in a program unless the explicit
15292 instantiation follows a declaration of the explicit specialization.
15294 For a given set of template parameters, if an explicit
15295 instantiation of a template appears after a declaration of an
15296 explicit specialization for that template, the explicit
15297 instantiation has no effect. */
15300 else if (DECL_EXPLICIT_INSTANTIATION (result))
15304 No program shall explicitly instantiate any template more
15307 We check DECL_NOT_REALLY_EXTERN so as not to complain when
15308 the first instantiation was `extern' and the second is not,
15309 and EXTERN_P for the opposite case. */
15310 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
15311 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
15312 /* If an "extern" explicit instantiation follows an ordinary
15313 explicit instantiation, the template is instantiated. */
15317 else if (!DECL_IMPLICIT_INSTANTIATION (result))
15319 error ("no matching template for %qD found", result);
15322 else if (!DECL_TEMPLATE_INFO (result))
15324 permerror (input_location, "explicit instantiation of non-template %q#D", result);
15328 if (storage == NULL_TREE)
15330 else if (storage == ridpointers[(int) RID_EXTERN])
15332 if (!in_system_header && (cxx_dialect == cxx98))
15333 pedwarn (input_location, OPT_pedantic,
15334 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
15339 error ("storage class %qD applied to template instantiation", storage);
15341 check_explicit_instantiation_namespace (result);
15342 mark_decl_instantiated (result, extern_p);
15344 instantiate_decl (result, /*defer_ok=*/1,
15345 /*expl_inst_class_mem_p=*/false);
15349 mark_class_instantiated (tree t, int extern_p)
15351 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
15352 SET_CLASSTYPE_INTERFACE_KNOWN (t);
15353 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
15354 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
15357 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
15358 rest_of_type_compilation (t, 1);
15362 /* Called from do_type_instantiation through binding_table_foreach to
15363 do recursive instantiation for the type bound in ENTRY. */
15365 bt_instantiate_type_proc (binding_entry entry, void *data)
15367 tree storage = *(tree *) data;
15369 if (MAYBE_CLASS_TYPE_P (entry->type)
15370 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
15371 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
15374 /* Called from do_type_instantiation to instantiate a member
15375 (a member function or a static member variable) of an
15376 explicitly instantiated class template. */
15378 instantiate_class_member (tree decl, int extern_p)
15380 mark_decl_instantiated (decl, extern_p);
15382 instantiate_decl (decl, /*defer_ok=*/1,
15383 /*expl_inst_class_mem_p=*/true);
15386 /* Perform an explicit instantiation of template class T. STORAGE, if
15387 non-null, is the RID for extern, inline or static. COMPLAIN is
15388 nonzero if this is called from the parser, zero if called recursively,
15389 since the standard is unclear (as detailed below). */
15392 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
15397 int previous_instantiation_extern_p = 0;
15399 if (TREE_CODE (t) == TYPE_DECL)
15402 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
15404 error ("explicit instantiation of non-template type %qT", t);
15410 if (!COMPLETE_TYPE_P (t))
15412 if (complain & tf_error)
15413 error ("explicit instantiation of %q#T before definition of template",
15418 if (storage != NULL_TREE)
15420 if (!in_system_header)
15422 if (storage == ridpointers[(int) RID_EXTERN])
15424 if (cxx_dialect == cxx98)
15425 pedwarn (input_location, OPT_pedantic,
15426 "ISO C++ 1998 forbids the use of %<extern%> on "
15427 "explicit instantiations");
15430 pedwarn (input_location, OPT_pedantic,
15431 "ISO C++ forbids the use of %qE"
15432 " on explicit instantiations", storage);
15435 if (storage == ridpointers[(int) RID_INLINE])
15437 else if (storage == ridpointers[(int) RID_EXTERN])
15439 else if (storage == ridpointers[(int) RID_STATIC])
15443 error ("storage class %qD applied to template instantiation",
15449 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
15451 /* DR 259 [temp.spec].
15453 Both an explicit instantiation and a declaration of an explicit
15454 specialization shall not appear in a program unless the explicit
15455 instantiation follows a declaration of the explicit specialization.
15457 For a given set of template parameters, if an explicit
15458 instantiation of a template appears after a declaration of an
15459 explicit specialization for that template, the explicit
15460 instantiation has no effect. */
15463 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
15467 No program shall explicitly instantiate any template more
15470 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
15471 instantiation was `extern'. If EXTERN_P then the second is.
15472 These cases are OK. */
15473 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
15475 if (!previous_instantiation_extern_p && !extern_p
15476 && (complain & tf_error))
15477 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
15479 /* If we've already instantiated the template, just return now. */
15480 if (!CLASSTYPE_INTERFACE_ONLY (t))
15484 check_explicit_instantiation_namespace (TYPE_NAME (t));
15485 mark_class_instantiated (t, extern_p);
15493 /* In contrast to implicit instantiation, where only the
15494 declarations, and not the definitions, of members are
15495 instantiated, we have here:
15499 The explicit instantiation of a class template specialization
15500 implies the instantiation of all of its members not
15501 previously explicitly specialized in the translation unit
15502 containing the explicit instantiation.
15504 Of course, we can't instantiate member template classes, since
15505 we don't have any arguments for them. Note that the standard
15506 is unclear on whether the instantiation of the members are
15507 *explicit* instantiations or not. However, the most natural
15508 interpretation is that it should be an explicit instantiation. */
15511 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
15512 if (TREE_CODE (tmp) == FUNCTION_DECL
15513 && DECL_TEMPLATE_INSTANTIATION (tmp))
15514 instantiate_class_member (tmp, extern_p);
15516 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
15517 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
15518 instantiate_class_member (tmp, extern_p);
15520 if (CLASSTYPE_NESTED_UTDS (t))
15521 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
15522 bt_instantiate_type_proc, &storage);
15526 /* Given a function DECL, which is a specialization of TMPL, modify
15527 DECL to be a re-instantiation of TMPL with the same template
15528 arguments. TMPL should be the template into which tsubst'ing
15529 should occur for DECL, not the most general template.
15531 One reason for doing this is a scenario like this:
15534 void f(const T&, int i);
15536 void g() { f(3, 7); }
15539 void f(const T& t, const int i) { }
15541 Note that when the template is first instantiated, with
15542 instantiate_template, the resulting DECL will have no name for the
15543 first parameter, and the wrong type for the second. So, when we go
15544 to instantiate the DECL, we regenerate it. */
15547 regenerate_decl_from_template (tree decl, tree tmpl)
15549 /* The arguments used to instantiate DECL, from the most general
15554 args = DECL_TI_ARGS (decl);
15555 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
15557 /* Make sure that we can see identifiers, and compute access
15559 push_access_scope (decl);
15561 if (TREE_CODE (decl) == FUNCTION_DECL)
15569 args_depth = TMPL_ARGS_DEPTH (args);
15570 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
15571 if (args_depth > parms_depth)
15572 args = get_innermost_template_args (args, parms_depth);
15574 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
15575 args, tf_error, NULL_TREE);
15577 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
15580 /* Merge parameter declarations. */
15581 decl_parm = skip_artificial_parms_for (decl,
15582 DECL_ARGUMENTS (decl));
15584 = skip_artificial_parms_for (code_pattern,
15585 DECL_ARGUMENTS (code_pattern));
15586 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
15591 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
15592 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
15593 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
15595 parm_type = type_decays_to (parm_type);
15596 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
15597 TREE_TYPE (decl_parm) = parm_type;
15598 attributes = DECL_ATTRIBUTES (pattern_parm);
15599 if (DECL_ATTRIBUTES (decl_parm) != attributes)
15601 DECL_ATTRIBUTES (decl_parm) = attributes;
15602 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
15604 decl_parm = TREE_CHAIN (decl_parm);
15605 pattern_parm = TREE_CHAIN (pattern_parm);
15607 /* Merge any parameters that match with the function parameter
15609 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
15612 tree expanded_types;
15613 /* Expand the TYPE_PACK_EXPANSION that provides the types for
15614 the parameters in this function parameter pack. */
15615 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
15616 args, tf_error, NULL_TREE);
15617 len = TREE_VEC_LENGTH (expanded_types);
15618 for (i = 0; i < len; i++)
15623 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
15624 /* Rename the parameter to include the index. */
15625 DECL_NAME (decl_parm) =
15626 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
15627 parm_type = TREE_VEC_ELT (expanded_types, i);
15628 parm_type = type_decays_to (parm_type);
15629 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
15630 TREE_TYPE (decl_parm) = parm_type;
15631 attributes = DECL_ATTRIBUTES (pattern_parm);
15632 if (DECL_ATTRIBUTES (decl_parm) != attributes)
15634 DECL_ATTRIBUTES (decl_parm) = attributes;
15635 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
15637 decl_parm = TREE_CHAIN (decl_parm);
15640 /* Merge additional specifiers from the CODE_PATTERN. */
15641 if (DECL_DECLARED_INLINE_P (code_pattern)
15642 && !DECL_DECLARED_INLINE_P (decl))
15643 DECL_DECLARED_INLINE_P (decl) = 1;
15645 else if (TREE_CODE (decl) == VAR_DECL)
15646 DECL_INITIAL (decl) =
15647 tsubst_expr (DECL_INITIAL (code_pattern), args,
15648 tf_error, DECL_TI_TEMPLATE (decl),
15649 /*integral_constant_expression_p=*/false);
15651 gcc_unreachable ();
15653 pop_access_scope (decl);
15656 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
15657 substituted to get DECL. */
15660 template_for_substitution (tree decl)
15662 tree tmpl = DECL_TI_TEMPLATE (decl);
15664 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
15665 for the instantiation. This is not always the most general
15666 template. Consider, for example:
15669 struct S { template <class U> void f();
15670 template <> void f<int>(); };
15672 and an instantiation of S<double>::f<int>. We want TD to be the
15673 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
15674 while (/* An instantiation cannot have a definition, so we need a
15675 more general template. */
15676 DECL_TEMPLATE_INSTANTIATION (tmpl)
15677 /* We must also deal with friend templates. Given:
15679 template <class T> struct S {
15680 template <class U> friend void f() {};
15683 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
15684 so far as the language is concerned, but that's still
15685 where we get the pattern for the instantiation from. On
15686 other hand, if the definition comes outside the class, say:
15688 template <class T> struct S {
15689 template <class U> friend void f();
15691 template <class U> friend void f() {}
15693 we don't need to look any further. That's what the check for
15694 DECL_INITIAL is for. */
15695 || (TREE_CODE (decl) == FUNCTION_DECL
15696 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
15697 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
15699 /* The present template, TD, should not be a definition. If it
15700 were a definition, we should be using it! Note that we
15701 cannot restructure the loop to just keep going until we find
15702 a template with a definition, since that might go too far if
15703 a specialization was declared, but not defined. */
15704 gcc_assert (TREE_CODE (decl) != VAR_DECL
15705 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
15707 /* Fetch the more general template. */
15708 tmpl = DECL_TI_TEMPLATE (tmpl);
15714 /* Returns true if we need to instantiate this template instance even if we
15715 know we aren't going to emit it.. */
15718 always_instantiate_p (tree decl)
15720 /* We always instantiate inline functions so that we can inline them. An
15721 explicit instantiation declaration prohibits implicit instantiation of
15722 non-inline functions. With high levels of optimization, we would
15723 normally inline non-inline functions -- but we're not allowed to do
15724 that for "extern template" functions. Therefore, we check
15725 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
15726 return ((TREE_CODE (decl) == FUNCTION_DECL
15727 && DECL_DECLARED_INLINE_P (decl))
15728 /* And we need to instantiate static data members so that
15729 their initializers are available in integral constant
15731 || (TREE_CODE (decl) == VAR_DECL
15732 && DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl)));
15735 /* Produce the definition of D, a _DECL generated from a template. If
15736 DEFER_OK is nonzero, then we don't have to actually do the
15737 instantiation now; we just have to do it sometime. Normally it is
15738 an error if this is an explicit instantiation but D is undefined.
15739 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
15740 explicitly instantiated class template. */
15743 instantiate_decl (tree d, int defer_ok,
15744 bool expl_inst_class_mem_p)
15746 tree tmpl = DECL_TI_TEMPLATE (d);
15753 bool pattern_defined;
15755 location_t saved_loc = input_location;
15758 /* This function should only be used to instantiate templates for
15759 functions and static member variables. */
15760 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
15761 || TREE_CODE (d) == VAR_DECL);
15763 /* Variables are never deferred; if instantiation is required, they
15764 are instantiated right away. That allows for better code in the
15765 case that an expression refers to the value of the variable --
15766 if the variable has a constant value the referring expression can
15767 take advantage of that fact. */
15768 if (TREE_CODE (d) == VAR_DECL)
15771 /* Don't instantiate cloned functions. Instead, instantiate the
15772 functions they cloned. */
15773 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
15774 d = DECL_CLONED_FUNCTION (d);
15776 if (DECL_TEMPLATE_INSTANTIATED (d)
15777 || DECL_TEMPLATE_SPECIALIZATION (d))
15778 /* D has already been instantiated or explicitly specialized, so
15779 there's nothing for us to do here.
15781 It might seem reasonable to check whether or not D is an explicit
15782 instantiation, and, if so, stop here. But when an explicit
15783 instantiation is deferred until the end of the compilation,
15784 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
15785 the instantiation. */
15788 /* Check to see whether we know that this template will be
15789 instantiated in some other file, as with "extern template"
15791 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
15793 /* In general, we do not instantiate such templates. */
15794 if (external_p && !always_instantiate_p (d))
15797 gen_tmpl = most_general_template (tmpl);
15798 gen_args = DECL_TI_ARGS (d);
15800 if (tmpl != gen_tmpl)
15801 /* We should already have the extra args. */
15802 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
15803 == TMPL_ARGS_DEPTH (gen_args));
15804 /* And what's in the hash table should match D. */
15805 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
15806 || spec == NULL_TREE);
15808 /* This needs to happen before any tsubsting. */
15809 if (! push_tinst_level (d))
15812 timevar_push (TV_PARSE);
15814 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
15815 for the instantiation. */
15816 td = template_for_substitution (d);
15817 code_pattern = DECL_TEMPLATE_RESULT (td);
15819 /* We should never be trying to instantiate a member of a class
15820 template or partial specialization. */
15821 gcc_assert (d != code_pattern);
15823 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
15824 || DECL_TEMPLATE_SPECIALIZATION (td))
15825 /* In the case of a friend template whose definition is provided
15826 outside the class, we may have too many arguments. Drop the
15827 ones we don't need. The same is true for specializations. */
15828 args = get_innermost_template_args
15829 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
15833 if (TREE_CODE (d) == FUNCTION_DECL)
15834 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
15836 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
15838 /* We may be in the middle of deferred access check. Disable it now. */
15839 push_deferring_access_checks (dk_no_deferred);
15841 /* Unless an explicit instantiation directive has already determined
15842 the linkage of D, remember that a definition is available for
15844 if (pattern_defined
15845 && !DECL_INTERFACE_KNOWN (d)
15846 && !DECL_NOT_REALLY_EXTERN (d))
15847 mark_definable (d);
15849 input_location = DECL_SOURCE_LOCATION (d);
15851 /* If D is a member of an explicitly instantiated class template,
15852 and no definition is available, treat it like an implicit
15854 if (!pattern_defined && expl_inst_class_mem_p
15855 && DECL_EXPLICIT_INSTANTIATION (d))
15857 DECL_NOT_REALLY_EXTERN (d) = 0;
15858 DECL_INTERFACE_KNOWN (d) = 0;
15859 SET_DECL_IMPLICIT_INSTANTIATION (d);
15864 /* Recheck the substitutions to obtain any warning messages
15865 about ignoring cv qualifiers. */
15866 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
15867 tree type = TREE_TYPE (gen);
15869 /* Make sure that we can see identifiers, and compute access
15870 correctly. D is already the target FUNCTION_DECL with the
15872 push_access_scope (d);
15874 if (TREE_CODE (gen) == FUNCTION_DECL)
15876 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
15877 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
15879 /* Don't simply tsubst the function type, as that will give
15880 duplicate warnings about poor parameter qualifications.
15881 The function arguments are the same as the decl_arguments
15882 without the top level cv qualifiers. */
15883 type = TREE_TYPE (type);
15885 tsubst (type, gen_args, tf_warning_or_error, d);
15887 pop_access_scope (d);
15890 /* Defer all other templates, unless we have been explicitly
15891 forbidden from doing so. */
15892 if (/* If there is no definition, we cannot instantiate the
15895 /* If it's OK to postpone instantiation, do so. */
15897 /* If this is a static data member that will be defined
15898 elsewhere, we don't want to instantiate the entire data
15899 member, but we do want to instantiate the initializer so that
15900 we can substitute that elsewhere. */
15901 || (external_p && TREE_CODE (d) == VAR_DECL))
15903 /* The definition of the static data member is now required so
15904 we must substitute the initializer. */
15905 if (TREE_CODE (d) == VAR_DECL
15906 && !DECL_INITIAL (d)
15907 && DECL_INITIAL (code_pattern))
15912 ns = decl_namespace_context (d);
15913 push_nested_namespace (ns);
15914 push_nested_class (DECL_CONTEXT (d));
15915 init = tsubst_expr (DECL_INITIAL (code_pattern),
15917 tf_warning_or_error, NULL_TREE,
15918 /*integral_constant_expression_p=*/false);
15919 cp_finish_decl (d, init, /*init_const_expr_p=*/false,
15920 /*asmspec_tree=*/NULL_TREE,
15921 LOOKUP_ONLYCONVERTING);
15922 pop_nested_class ();
15923 pop_nested_namespace (ns);
15926 /* We restore the source position here because it's used by
15927 add_pending_template. */
15928 input_location = saved_loc;
15930 if (at_eof && !pattern_defined
15931 && DECL_EXPLICIT_INSTANTIATION (d)
15932 && DECL_NOT_REALLY_EXTERN (d))
15935 The definition of a non-exported function template, a
15936 non-exported member function template, or a non-exported
15937 member function or static data member of a class template
15938 shall be present in every translation unit in which it is
15939 explicitly instantiated. */
15940 permerror (input_location, "explicit instantiation of %qD "
15941 "but no definition available", d);
15943 /* ??? Historically, we have instantiated inline functions, even
15944 when marked as "extern template". */
15945 if (!(external_p && TREE_CODE (d) == VAR_DECL))
15946 add_pending_template (d);
15949 /* Tell the repository that D is available in this translation unit
15950 -- and see if it is supposed to be instantiated here. */
15951 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
15953 /* In a PCH file, despite the fact that the repository hasn't
15954 requested instantiation in the PCH it is still possible that
15955 an instantiation will be required in a file that includes the
15958 add_pending_template (d);
15959 /* Instantiate inline functions so that the inliner can do its
15960 job, even though we'll not be emitting a copy of this
15962 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
15966 need_push = !cfun || !global_bindings_p ();
15968 push_to_top_level ();
15970 /* Mark D as instantiated so that recursive calls to
15971 instantiate_decl do not try to instantiate it again. */
15972 DECL_TEMPLATE_INSTANTIATED (d) = 1;
15974 /* Regenerate the declaration in case the template has been modified
15975 by a subsequent redeclaration. */
15976 regenerate_decl_from_template (d, td);
15978 /* We already set the file and line above. Reset them now in case
15979 they changed as a result of calling regenerate_decl_from_template. */
15980 input_location = DECL_SOURCE_LOCATION (d);
15982 if (TREE_CODE (d) == VAR_DECL)
15986 /* Clear out DECL_RTL; whatever was there before may not be right
15987 since we've reset the type of the declaration. */
15988 SET_DECL_RTL (d, NULL_RTX);
15989 DECL_IN_AGGR_P (d) = 0;
15991 /* The initializer is placed in DECL_INITIAL by
15992 regenerate_decl_from_template. Pull it out so that
15993 cp_finish_decl can process it. */
15994 init = DECL_INITIAL (d);
15995 DECL_INITIAL (d) = NULL_TREE;
15996 DECL_INITIALIZED_P (d) = 0;
15998 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
15999 initializer. That function will defer actual emission until
16000 we have a chance to determine linkage. */
16001 DECL_EXTERNAL (d) = 0;
16003 /* Enter the scope of D so that access-checking works correctly. */
16004 push_nested_class (DECL_CONTEXT (d));
16005 cp_finish_decl (d, init, false, NULL_TREE, 0);
16006 pop_nested_class ();
16008 else if (TREE_CODE (d) == FUNCTION_DECL)
16010 htab_t saved_local_specializations;
16015 /* Save away the current list, in case we are instantiating one
16016 template from within the body of another. */
16017 saved_local_specializations = local_specializations;
16019 /* Set up the list of local specializations. */
16020 local_specializations = htab_create (37,
16021 hash_local_specialization,
16022 eq_local_specializations,
16025 /* Set up context. */
16026 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
16028 /* Create substitution entries for the parameters. */
16029 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
16030 tmpl_parm = DECL_ARGUMENTS (subst_decl);
16031 spec_parm = DECL_ARGUMENTS (d);
16032 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
16034 register_local_specialization (spec_parm, tmpl_parm);
16035 spec_parm = skip_artificial_parms_for (d, spec_parm);
16036 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
16038 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16040 register_local_specialization (spec_parm, tmpl_parm);
16041 tmpl_parm = TREE_CHAIN (tmpl_parm);
16042 spec_parm = TREE_CHAIN (spec_parm);
16044 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16046 /* Register the (value) argument pack as a specialization of
16047 TMPL_PARM, then move on. */
16048 tree argpack = make_fnparm_pack (spec_parm);
16049 register_local_specialization (argpack, tmpl_parm);
16050 tmpl_parm = TREE_CHAIN (tmpl_parm);
16051 spec_parm = NULL_TREE;
16053 gcc_assert (!spec_parm);
16055 /* Substitute into the body of the function. */
16056 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
16057 tf_warning_or_error, tmpl,
16058 /*integral_constant_expression_p=*/false);
16060 /* Set the current input_location to the end of the function
16061 so that finish_function knows where we are. */
16062 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
16064 /* We don't need the local specializations any more. */
16065 htab_delete (local_specializations);
16066 local_specializations = saved_local_specializations;
16068 /* Finish the function. */
16069 d = finish_function (0);
16070 expand_or_defer_fn (d);
16073 /* We're not deferring instantiation any more. */
16074 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
16077 pop_from_top_level ();
16080 input_location = saved_loc;
16081 pop_deferring_access_checks ();
16082 pop_tinst_level ();
16084 timevar_pop (TV_PARSE);
16089 /* Run through the list of templates that we wish we could
16090 instantiate, and instantiate any we can. RETRIES is the
16091 number of times we retry pending template instantiation. */
16094 instantiate_pending_templates (int retries)
16097 location_t saved_loc = input_location;
16099 /* Instantiating templates may trigger vtable generation. This in turn
16100 may require further template instantiations. We place a limit here
16101 to avoid infinite loop. */
16102 if (pending_templates && retries >= max_tinst_depth)
16104 tree decl = pending_templates->tinst->decl;
16106 error ("template instantiation depth exceeds maximum of %d"
16107 " instantiating %q+D, possibly from virtual table generation"
16108 " (use -ftemplate-depth-NN to increase the maximum)",
16109 max_tinst_depth, decl);
16110 if (TREE_CODE (decl) == FUNCTION_DECL)
16111 /* Pretend that we defined it. */
16112 DECL_INITIAL (decl) = error_mark_node;
16118 struct pending_template **t = &pending_templates;
16119 struct pending_template *last = NULL;
16123 tree instantiation = reopen_tinst_level ((*t)->tinst);
16124 bool complete = false;
16126 if (TYPE_P (instantiation))
16130 if (!COMPLETE_TYPE_P (instantiation))
16132 instantiate_class_template (instantiation);
16133 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
16134 for (fn = TYPE_METHODS (instantiation);
16136 fn = TREE_CHAIN (fn))
16137 if (! DECL_ARTIFICIAL (fn))
16138 instantiate_decl (fn,
16140 /*expl_inst_class_mem_p=*/false);
16141 if (COMPLETE_TYPE_P (instantiation))
16145 complete = COMPLETE_TYPE_P (instantiation);
16149 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
16150 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
16153 = instantiate_decl (instantiation,
16155 /*expl_inst_class_mem_p=*/false);
16156 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
16160 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
16161 || DECL_TEMPLATE_INSTANTIATED (instantiation));
16165 /* If INSTANTIATION has been instantiated, then we don't
16166 need to consider it again in the future. */
16174 current_tinst_level = NULL;
16176 last_pending_template = last;
16178 while (reconsider);
16180 input_location = saved_loc;
16183 /* Substitute ARGVEC into T, which is a list of initializers for
16184 either base class or a non-static data member. The TREE_PURPOSEs
16185 are DECLs, and the TREE_VALUEs are the initializer values. Used by
16186 instantiate_decl. */
16189 tsubst_initializer_list (tree t, tree argvec)
16191 tree inits = NULL_TREE;
16193 for (; t; t = TREE_CHAIN (t))
16197 tree expanded_bases = NULL_TREE;
16198 tree expanded_arguments = NULL_TREE;
16201 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
16206 /* Expand the base class expansion type into separate base
16208 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
16209 tf_warning_or_error,
16211 if (expanded_bases == error_mark_node)
16214 /* We'll be building separate TREE_LISTs of arguments for
16216 len = TREE_VEC_LENGTH (expanded_bases);
16217 expanded_arguments = make_tree_vec (len);
16218 for (i = 0; i < len; i++)
16219 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
16221 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
16222 expand each argument in the TREE_VALUE of t. */
16223 expr = make_node (EXPR_PACK_EXPANSION);
16224 PACK_EXPANSION_PARAMETER_PACKS (expr) =
16225 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
16227 if (TREE_VALUE (t) == void_type_node)
16228 /* VOID_TYPE_NODE is used to indicate
16229 value-initialization. */
16231 for (i = 0; i < len; i++)
16232 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
16236 /* Substitute parameter packs into each argument in the
16238 in_base_initializer = 1;
16239 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
16241 tree expanded_exprs;
16243 /* Expand the argument. */
16244 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
16246 = tsubst_pack_expansion (expr, argvec,
16247 tf_warning_or_error,
16249 if (expanded_exprs == error_mark_node)
16252 /* Prepend each of the expanded expressions to the
16253 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
16254 for (i = 0; i < len; i++)
16256 TREE_VEC_ELT (expanded_arguments, i) =
16257 tree_cons (NULL_TREE,
16258 TREE_VEC_ELT (expanded_exprs, i),
16259 TREE_VEC_ELT (expanded_arguments, i));
16262 in_base_initializer = 0;
16264 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
16265 since we built them backwards. */
16266 for (i = 0; i < len; i++)
16268 TREE_VEC_ELT (expanded_arguments, i) =
16269 nreverse (TREE_VEC_ELT (expanded_arguments, i));
16274 for (i = 0; i < len; ++i)
16276 if (expanded_bases)
16278 decl = TREE_VEC_ELT (expanded_bases, i);
16279 decl = expand_member_init (decl);
16280 init = TREE_VEC_ELT (expanded_arguments, i);
16284 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
16285 tf_warning_or_error, NULL_TREE);
16287 decl = expand_member_init (decl);
16288 if (decl && !DECL_P (decl))
16289 in_base_initializer = 1;
16291 init = tsubst_expr (TREE_VALUE (t), argvec,
16292 tf_warning_or_error, NULL_TREE,
16293 /*integral_constant_expression_p=*/false);
16294 in_base_initializer = 0;
16299 init = build_tree_list (decl, init);
16300 TREE_CHAIN (init) = inits;
16308 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
16311 set_current_access_from_decl (tree decl)
16313 if (TREE_PRIVATE (decl))
16314 current_access_specifier = access_private_node;
16315 else if (TREE_PROTECTED (decl))
16316 current_access_specifier = access_protected_node;
16318 current_access_specifier = access_public_node;
16321 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
16322 is the instantiation (which should have been created with
16323 start_enum) and ARGS are the template arguments to use. */
16326 tsubst_enum (tree tag, tree newtag, tree args)
16330 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
16335 decl = TREE_VALUE (e);
16336 /* Note that in a template enum, the TREE_VALUE is the
16337 CONST_DECL, not the corresponding INTEGER_CST. */
16338 value = tsubst_expr (DECL_INITIAL (decl),
16339 args, tf_warning_or_error, NULL_TREE,
16340 /*integral_constant_expression_p=*/true);
16342 /* Give this enumeration constant the correct access. */
16343 set_current_access_from_decl (decl);
16345 /* Actually build the enumerator itself. */
16346 build_enumerator (DECL_NAME (decl), value, newtag);
16349 finish_enum (newtag);
16350 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
16351 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
16354 /* DECL is a FUNCTION_DECL that is a template specialization. Return
16355 its type -- but without substituting the innermost set of template
16356 arguments. So, innermost set of template parameters will appear in
16360 get_mostly_instantiated_function_type (tree decl)
16368 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
16369 targs = DECL_TI_ARGS (decl);
16370 tparms = DECL_TEMPLATE_PARMS (tmpl);
16371 parm_depth = TMPL_PARMS_DEPTH (tparms);
16373 /* There should be as many levels of arguments as there are levels
16375 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
16377 fn_type = TREE_TYPE (tmpl);
16379 if (parm_depth == 1)
16380 /* No substitution is necessary. */
16384 int i, save_access_control;
16387 /* Replace the innermost level of the TARGS with NULL_TREEs to
16388 let tsubst know not to substitute for those parameters. */
16389 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
16390 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
16391 SET_TMPL_ARGS_LEVEL (partial_args, i,
16392 TMPL_ARGS_LEVEL (targs, i));
16393 SET_TMPL_ARGS_LEVEL (partial_args,
16394 TMPL_ARGS_DEPTH (targs),
16395 make_tree_vec (DECL_NTPARMS (tmpl)));
16397 /* Disable access control as this function is used only during
16399 save_access_control = flag_access_control;
16400 flag_access_control = 0;
16402 ++processing_template_decl;
16403 /* Now, do the (partial) substitution to figure out the
16404 appropriate function type. */
16405 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
16406 --processing_template_decl;
16408 /* Substitute into the template parameters to obtain the real
16409 innermost set of parameters. This step is important if the
16410 innermost set of template parameters contains value
16411 parameters whose types depend on outer template parameters. */
16412 TREE_VEC_LENGTH (partial_args)--;
16413 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
16415 flag_access_control = save_access_control;
16421 /* Return truthvalue if we're processing a template different from
16422 the last one involved in diagnostics. */
16424 problematic_instantiation_changed (void)
16426 return last_template_error_tick != tinst_level_tick;
16429 /* Remember current template involved in diagnostics. */
16431 record_last_problematic_instantiation (void)
16433 last_template_error_tick = tinst_level_tick;
16436 struct tinst_level *
16437 current_instantiation (void)
16439 return current_tinst_level;
16442 /* [temp.param] Check that template non-type parm TYPE is of an allowable
16443 type. Return zero for ok, nonzero for disallowed. Issue error and
16444 warning messages under control of COMPLAIN. */
16447 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
16449 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
16451 else if (POINTER_TYPE_P (type))
16453 else if (TYPE_PTR_TO_MEMBER_P (type))
16455 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
16457 else if (TREE_CODE (type) == TYPENAME_TYPE)
16460 if (complain & tf_error)
16461 error ("%q#T is not a valid type for a template constant parameter", type);
16465 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
16466 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
16469 dependent_type_p_r (tree type)
16475 A type is dependent if it is:
16477 -- a template parameter. Template template parameters are types
16478 for us (since TYPE_P holds true for them) so we handle
16480 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
16481 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
16483 /* -- a qualified-id with a nested-name-specifier which contains a
16484 class-name that names a dependent type or whose unqualified-id
16485 names a dependent type. */
16486 if (TREE_CODE (type) == TYPENAME_TYPE)
16488 /* -- a cv-qualified type where the cv-unqualified type is
16490 type = TYPE_MAIN_VARIANT (type);
16491 /* -- a compound type constructed from any dependent type. */
16492 if (TYPE_PTR_TO_MEMBER_P (type))
16493 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
16494 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
16496 else if (TREE_CODE (type) == POINTER_TYPE
16497 || TREE_CODE (type) == REFERENCE_TYPE)
16498 return dependent_type_p (TREE_TYPE (type));
16499 else if (TREE_CODE (type) == FUNCTION_TYPE
16500 || TREE_CODE (type) == METHOD_TYPE)
16504 if (dependent_type_p (TREE_TYPE (type)))
16506 for (arg_type = TYPE_ARG_TYPES (type);
16508 arg_type = TREE_CHAIN (arg_type))
16509 if (dependent_type_p (TREE_VALUE (arg_type)))
16513 /* -- an array type constructed from any dependent type or whose
16514 size is specified by a constant expression that is
16515 value-dependent. */
16516 if (TREE_CODE (type) == ARRAY_TYPE)
16518 if (TYPE_DOMAIN (type)
16519 && dependent_type_p (TYPE_DOMAIN (type)))
16521 return dependent_type_p (TREE_TYPE (type));
16523 else if (TREE_CODE (type) == INTEGER_TYPE
16524 && !TREE_CONSTANT (TYPE_MAX_VALUE (type)))
16526 /* If this is the TYPE_DOMAIN of an array type, consider it
16527 dependent. We already checked for value-dependence in
16528 compute_array_index_type. */
16529 return type_dependent_expression_p (TYPE_MAX_VALUE (type));
16532 /* -- a template-id in which either the template name is a template
16534 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
16536 /* ... or any of the template arguments is a dependent type or
16537 an expression that is type-dependent or value-dependent. */
16538 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
16539 && (any_dependent_template_arguments_p
16540 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
16543 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
16544 argument of the `typeof' expression is not type-dependent, then
16545 it should already been have resolved. */
16546 if (TREE_CODE (type) == TYPEOF_TYPE
16547 || TREE_CODE (type) == DECLTYPE_TYPE)
16550 /* A template argument pack is dependent if any of its packed
16552 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
16554 tree args = ARGUMENT_PACK_ARGS (type);
16555 int i, len = TREE_VEC_LENGTH (args);
16556 for (i = 0; i < len; ++i)
16557 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
16561 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
16562 be template parameters. */
16563 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
16566 /* The standard does not specifically mention types that are local
16567 to template functions or local classes, but they should be
16568 considered dependent too. For example:
16570 template <int I> void f() {
16575 The size of `E' cannot be known until the value of `I' has been
16576 determined. Therefore, `E' must be considered dependent. */
16577 scope = TYPE_CONTEXT (type);
16578 if (scope && TYPE_P (scope))
16579 return dependent_type_p (scope);
16580 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
16581 return type_dependent_expression_p (scope);
16583 /* Other types are non-dependent. */
16587 /* Returns TRUE if TYPE is dependent, in the sense of
16588 [temp.dep.type]. */
16591 dependent_type_p (tree type)
16593 /* If there are no template parameters in scope, then there can't be
16594 any dependent types. */
16595 if (!processing_template_decl)
16597 /* If we are not processing a template, then nobody should be
16598 providing us with a dependent type. */
16600 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
16604 /* If the type is NULL, we have not computed a type for the entity
16605 in question; in that case, the type is dependent. */
16609 /* Erroneous types can be considered non-dependent. */
16610 if (type == error_mark_node)
16613 /* If we have not already computed the appropriate value for TYPE,
16615 if (!TYPE_DEPENDENT_P_VALID (type))
16617 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
16618 TYPE_DEPENDENT_P_VALID (type) = 1;
16621 return TYPE_DEPENDENT_P (type);
16624 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
16625 lookup. In other words, a dependent type that is not the current
16629 dependent_scope_p (tree scope)
16631 return (scope && TYPE_P (scope) && dependent_type_p (scope)
16632 && !currently_open_class (scope));
16635 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
16638 dependent_scope_ref_p (tree expression, bool criterion (tree))
16643 gcc_assert (TREE_CODE (expression) == SCOPE_REF);
16645 if (!TYPE_P (TREE_OPERAND (expression, 0)))
16648 scope = TREE_OPERAND (expression, 0);
16649 name = TREE_OPERAND (expression, 1);
16653 An id-expression is type-dependent if it contains a
16654 nested-name-specifier that contains a class-name that names a
16656 /* The suggested resolution to Core Issue 224 implies that if the
16657 qualifying type is the current class, then we must peek
16660 && currently_open_class (scope)
16661 && !criterion (name))
16663 if (dependent_type_p (scope))
16669 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
16670 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
16674 value_dependent_expression_p (tree expression)
16676 if (!processing_template_decl)
16679 /* A name declared with a dependent type. */
16680 if (DECL_P (expression) && type_dependent_expression_p (expression))
16683 switch (TREE_CODE (expression))
16685 case IDENTIFIER_NODE:
16686 /* A name that has not been looked up -- must be dependent. */
16689 case TEMPLATE_PARM_INDEX:
16690 /* A non-type template parm. */
16694 /* A non-type template parm. */
16695 if (DECL_TEMPLATE_PARM_P (expression))
16697 return value_dependent_expression_p (DECL_INITIAL (expression));
16700 /* A constant with integral or enumeration type and is initialized
16701 with an expression that is value-dependent. */
16702 if (DECL_INITIAL (expression)
16703 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
16704 && value_dependent_expression_p (DECL_INITIAL (expression)))
16708 case DYNAMIC_CAST_EXPR:
16709 case STATIC_CAST_EXPR:
16710 case CONST_CAST_EXPR:
16711 case REINTERPRET_CAST_EXPR:
16713 /* These expressions are value-dependent if the type to which
16714 the cast occurs is dependent or the expression being casted
16715 is value-dependent. */
16717 tree type = TREE_TYPE (expression);
16719 if (dependent_type_p (type))
16722 /* A functional cast has a list of operands. */
16723 expression = TREE_OPERAND (expression, 0);
16726 /* If there are no operands, it must be an expression such
16727 as "int()". This should not happen for aggregate types
16728 because it would form non-constant expressions. */
16729 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
16734 if (TREE_CODE (expression) == TREE_LIST)
16735 return any_value_dependent_elements_p (expression);
16737 return value_dependent_expression_p (expression);
16742 /* A `sizeof' expression is value-dependent if the operand is
16743 type-dependent or is a pack expansion. */
16744 expression = TREE_OPERAND (expression, 0);
16745 if (PACK_EXPANSION_P (expression))
16747 else if (TYPE_P (expression))
16748 return dependent_type_p (expression);
16749 return type_dependent_expression_p (expression);
16752 return dependent_scope_ref_p (expression, value_dependent_expression_p);
16754 case COMPONENT_REF:
16755 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
16756 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
16759 /* A CALL_EXPR may appear in a constant expression if it is a
16760 call to a builtin function, e.g., __builtin_constant_p. All
16761 such calls are value-dependent. */
16764 case NONTYPE_ARGUMENT_PACK:
16765 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
16766 is value-dependent. */
16768 tree values = ARGUMENT_PACK_ARGS (expression);
16769 int i, len = TREE_VEC_LENGTH (values);
16771 for (i = 0; i < len; ++i)
16772 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
16780 tree type2 = TRAIT_EXPR_TYPE2 (expression);
16781 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
16782 || (type2 ? dependent_type_p (type2) : false));
16786 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
16787 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
16790 /* A constant expression is value-dependent if any subexpression is
16791 value-dependent. */
16792 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
16794 case tcc_reference:
16796 return (value_dependent_expression_p
16797 (TREE_OPERAND (expression, 0)));
16799 case tcc_comparison:
16801 return ((value_dependent_expression_p
16802 (TREE_OPERAND (expression, 0)))
16803 || (value_dependent_expression_p
16804 (TREE_OPERAND (expression, 1))));
16806 case tcc_expression:
16810 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
16811 /* In some cases, some of the operands may be missing.
16812 (For example, in the case of PREDECREMENT_EXPR, the
16813 amount to increment by may be missing.) That doesn't
16814 make the expression dependent. */
16815 if (TREE_OPERAND (expression, i)
16816 && (value_dependent_expression_p
16817 (TREE_OPERAND (expression, i))))
16827 /* The expression is not value-dependent. */
16831 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
16832 [temp.dep.expr]. */
16835 type_dependent_expression_p (tree expression)
16837 if (!processing_template_decl)
16840 if (expression == error_mark_node)
16843 /* An unresolved name is always dependent. */
16844 if (TREE_CODE (expression) == IDENTIFIER_NODE
16845 || TREE_CODE (expression) == USING_DECL)
16848 /* Some expression forms are never type-dependent. */
16849 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
16850 || TREE_CODE (expression) == SIZEOF_EXPR
16851 || TREE_CODE (expression) == ALIGNOF_EXPR
16852 || TREE_CODE (expression) == TRAIT_EXPR
16853 || TREE_CODE (expression) == TYPEID_EXPR
16854 || TREE_CODE (expression) == DELETE_EXPR
16855 || TREE_CODE (expression) == VEC_DELETE_EXPR
16856 || TREE_CODE (expression) == THROW_EXPR)
16859 /* The types of these expressions depends only on the type to which
16860 the cast occurs. */
16861 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
16862 || TREE_CODE (expression) == STATIC_CAST_EXPR
16863 || TREE_CODE (expression) == CONST_CAST_EXPR
16864 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
16865 || TREE_CODE (expression) == CAST_EXPR)
16866 return dependent_type_p (TREE_TYPE (expression));
16868 /* The types of these expressions depends only on the type created
16869 by the expression. */
16870 if (TREE_CODE (expression) == NEW_EXPR
16871 || TREE_CODE (expression) == VEC_NEW_EXPR)
16873 /* For NEW_EXPR tree nodes created inside a template, either
16874 the object type itself or a TREE_LIST may appear as the
16876 tree type = TREE_OPERAND (expression, 1);
16877 if (TREE_CODE (type) == TREE_LIST)
16878 /* This is an array type. We need to check array dimensions
16880 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
16881 || value_dependent_expression_p
16882 (TREE_OPERAND (TREE_VALUE (type), 1));
16884 return dependent_type_p (type);
16887 if (TREE_CODE (expression) == SCOPE_REF
16888 && dependent_scope_ref_p (expression,
16889 type_dependent_expression_p))
16892 if (TREE_CODE (expression) == FUNCTION_DECL
16893 && DECL_LANG_SPECIFIC (expression)
16894 && DECL_TEMPLATE_INFO (expression)
16895 && (any_dependent_template_arguments_p
16896 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
16899 if (TREE_CODE (expression) == TEMPLATE_DECL
16900 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
16903 if (TREE_CODE (expression) == STMT_EXPR)
16904 expression = stmt_expr_value_expr (expression);
16906 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
16911 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
16913 if (type_dependent_expression_p (elt))
16919 if (TREE_TYPE (expression) == unknown_type_node)
16921 if (TREE_CODE (expression) == ADDR_EXPR)
16922 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
16923 if (TREE_CODE (expression) == COMPONENT_REF
16924 || TREE_CODE (expression) == OFFSET_REF)
16926 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
16928 expression = TREE_OPERAND (expression, 1);
16929 if (TREE_CODE (expression) == IDENTIFIER_NODE)
16932 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
16933 if (TREE_CODE (expression) == SCOPE_REF)
16936 if (TREE_CODE (expression) == BASELINK)
16937 expression = BASELINK_FUNCTIONS (expression);
16939 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
16941 if (any_dependent_template_arguments_p
16942 (TREE_OPERAND (expression, 1)))
16944 expression = TREE_OPERAND (expression, 0);
16946 gcc_assert (TREE_CODE (expression) == OVERLOAD
16947 || TREE_CODE (expression) == FUNCTION_DECL);
16951 if (type_dependent_expression_p (OVL_CURRENT (expression)))
16953 expression = OVL_NEXT (expression);
16958 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
16960 return (dependent_type_p (TREE_TYPE (expression)));
16963 /* Like type_dependent_expression_p, but it also works while not processing
16964 a template definition, i.e. during substitution or mangling. */
16967 type_dependent_expression_p_push (tree expr)
16970 ++processing_template_decl;
16971 b = type_dependent_expression_p (expr);
16972 --processing_template_decl;
16976 /* Returns TRUE if ARGS contains a type-dependent expression. */
16979 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
16984 for (i = 0; VEC_iterate (tree, args, i, arg); ++i)
16986 if (type_dependent_expression_p (arg))
16992 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
16993 expressions) contains any value-dependent expressions. */
16996 any_value_dependent_elements_p (const_tree list)
16998 for (; list; list = TREE_CHAIN (list))
16999 if (value_dependent_expression_p (TREE_VALUE (list)))
17005 /* Returns TRUE if the ARG (a template argument) is dependent. */
17008 dependent_template_arg_p (tree arg)
17010 if (!processing_template_decl)
17013 if (TREE_CODE (arg) == TEMPLATE_DECL
17014 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17015 return dependent_template_p (arg);
17016 else if (ARGUMENT_PACK_P (arg))
17018 tree args = ARGUMENT_PACK_ARGS (arg);
17019 int i, len = TREE_VEC_LENGTH (args);
17020 for (i = 0; i < len; ++i)
17022 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17028 else if (TYPE_P (arg))
17029 return dependent_type_p (arg);
17031 return (type_dependent_expression_p (arg)
17032 || value_dependent_expression_p (arg));
17035 /* Returns true if ARGS (a collection of template arguments) contains
17036 any types that require structural equality testing. */
17039 any_template_arguments_need_structural_equality_p (tree args)
17046 if (args == error_mark_node)
17049 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17051 tree level = TMPL_ARGS_LEVEL (args, i + 1);
17052 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17054 tree arg = TREE_VEC_ELT (level, j);
17055 tree packed_args = NULL_TREE;
17058 if (ARGUMENT_PACK_P (arg))
17060 /* Look inside the argument pack. */
17061 packed_args = ARGUMENT_PACK_ARGS (arg);
17062 len = TREE_VEC_LENGTH (packed_args);
17065 for (k = 0; k < len; ++k)
17068 arg = TREE_VEC_ELT (packed_args, k);
17070 if (error_operand_p (arg))
17072 else if (TREE_CODE (arg) == TEMPLATE_DECL
17073 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17075 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
17077 else if (!TYPE_P (arg) && TREE_TYPE (arg)
17078 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
17087 /* Returns true if ARGS (a collection of template arguments) contains
17088 any dependent arguments. */
17091 any_dependent_template_arguments_p (const_tree args)
17098 if (args == error_mark_node)
17101 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17103 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
17104 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17105 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
17112 /* Returns TRUE if the template TMPL is dependent. */
17115 dependent_template_p (tree tmpl)
17117 if (TREE_CODE (tmpl) == OVERLOAD)
17121 if (dependent_template_p (OVL_FUNCTION (tmpl)))
17123 tmpl = OVL_CHAIN (tmpl);
17128 /* Template template parameters are dependent. */
17129 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
17130 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
17132 /* So are names that have not been looked up. */
17133 if (TREE_CODE (tmpl) == SCOPE_REF
17134 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
17136 /* So are member templates of dependent classes. */
17137 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
17138 return dependent_type_p (DECL_CONTEXT (tmpl));
17142 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
17145 dependent_template_id_p (tree tmpl, tree args)
17147 return (dependent_template_p (tmpl)
17148 || any_dependent_template_arguments_p (args));
17151 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
17155 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
17159 if (!processing_template_decl)
17162 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
17164 tree decl = TREE_VEC_ELT (declv, i);
17165 tree init = TREE_VEC_ELT (initv, i);
17166 tree cond = TREE_VEC_ELT (condv, i);
17167 tree incr = TREE_VEC_ELT (incrv, i);
17169 if (type_dependent_expression_p (decl))
17172 if (init && type_dependent_expression_p (init))
17175 if (type_dependent_expression_p (cond))
17178 if (COMPARISON_CLASS_P (cond)
17179 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
17180 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
17183 if (TREE_CODE (incr) == MODOP_EXPR)
17185 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
17186 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
17189 else if (type_dependent_expression_p (incr))
17191 else if (TREE_CODE (incr) == MODIFY_EXPR)
17193 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
17195 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
17197 tree t = TREE_OPERAND (incr, 1);
17198 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
17199 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
17208 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
17209 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
17210 no such TYPE can be found. Note that this function peers inside
17211 uninstantiated templates and therefore should be used only in
17212 extremely limited situations. ONLY_CURRENT_P restricts this
17213 peering to the currently open classes hierarchy (which is required
17214 when comparing types). */
17217 resolve_typename_type (tree type, bool only_current_p)
17226 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
17228 scope = TYPE_CONTEXT (type);
17229 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
17230 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
17231 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
17232 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
17233 identifier of the TYPENAME_TYPE anymore.
17234 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
17235 TYPENAME_TYPE instead, we avoid messing up with a possible
17236 typedef variant case. */
17237 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
17239 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
17240 it first before we can figure out what NAME refers to. */
17241 if (TREE_CODE (scope) == TYPENAME_TYPE)
17242 scope = resolve_typename_type (scope, only_current_p);
17243 /* If we don't know what SCOPE refers to, then we cannot resolve the
17245 if (TREE_CODE (scope) == TYPENAME_TYPE)
17247 /* If the SCOPE is a template type parameter, we have no way of
17248 resolving the name. */
17249 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
17251 /* If the SCOPE is not the current instantiation, there's no reason
17252 to look inside it. */
17253 if (only_current_p && !currently_open_class (scope))
17255 /* If SCOPE isn't the template itself, it will not have a valid
17256 TYPE_FIELDS list. */
17257 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
17258 /* scope is either the template itself or a compatible instantiation
17259 like X<T>, so look up the name in the original template. */
17260 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
17262 /* scope is a partial instantiation, so we can't do the lookup or we
17263 will lose the template arguments. */
17265 /* Enter the SCOPE so that name lookup will be resolved as if we
17266 were in the class definition. In particular, SCOPE will no
17267 longer be considered a dependent type. */
17268 pushed_scope = push_scope (scope);
17269 /* Look up the declaration. */
17270 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
17272 result = NULL_TREE;
17274 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
17275 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
17278 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
17279 && TREE_CODE (decl) == TYPE_DECL)
17281 result = TREE_TYPE (decl);
17282 if (result == error_mark_node)
17283 result = NULL_TREE;
17285 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
17286 && DECL_CLASS_TEMPLATE_P (decl))
17290 /* Obtain the template and the arguments. */
17291 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
17292 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
17293 /* Instantiate the template. */
17294 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
17295 /*entering_scope=*/0,
17296 tf_error | tf_user);
17297 if (result == error_mark_node)
17298 result = NULL_TREE;
17301 /* Leave the SCOPE. */
17303 pop_scope (pushed_scope);
17305 /* If we failed to resolve it, return the original typename. */
17309 /* If lookup found a typename type, resolve that too. */
17310 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
17312 /* Ill-formed programs can cause infinite recursion here, so we
17313 must catch that. */
17314 TYPENAME_IS_RESOLVING_P (type) = 1;
17315 result = resolve_typename_type (result, only_current_p);
17316 TYPENAME_IS_RESOLVING_P (type) = 0;
17319 /* Qualify the resulting type. */
17320 quals = cp_type_quals (type);
17322 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
17327 /* EXPR is an expression which is not type-dependent. Return a proxy
17328 for EXPR that can be used to compute the types of larger
17329 expressions containing EXPR. */
17332 build_non_dependent_expr (tree expr)
17336 /* Preserve null pointer constants so that the type of things like
17337 "p == 0" where "p" is a pointer can be determined. */
17338 if (null_ptr_cst_p (expr))
17340 /* Preserve OVERLOADs; the functions must be available to resolve
17343 if (TREE_CODE (inner_expr) == STMT_EXPR)
17344 inner_expr = stmt_expr_value_expr (inner_expr);
17345 if (TREE_CODE (inner_expr) == ADDR_EXPR)
17346 inner_expr = TREE_OPERAND (inner_expr, 0);
17347 if (TREE_CODE (inner_expr) == COMPONENT_REF)
17348 inner_expr = TREE_OPERAND (inner_expr, 1);
17349 if (is_overloaded_fn (inner_expr)
17350 || TREE_CODE (inner_expr) == OFFSET_REF)
17352 /* There is no need to return a proxy for a variable. */
17353 if (TREE_CODE (expr) == VAR_DECL)
17355 /* Preserve string constants; conversions from string constants to
17356 "char *" are allowed, even though normally a "const char *"
17357 cannot be used to initialize a "char *". */
17358 if (TREE_CODE (expr) == STRING_CST)
17360 /* Preserve arithmetic constants, as an optimization -- there is no
17361 reason to create a new node. */
17362 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
17364 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
17365 There is at least one place where we want to know that a
17366 particular expression is a throw-expression: when checking a ?:
17367 expression, there are special rules if the second or third
17368 argument is a throw-expression. */
17369 if (TREE_CODE (expr) == THROW_EXPR)
17372 if (TREE_CODE (expr) == COND_EXPR)
17373 return build3 (COND_EXPR,
17375 TREE_OPERAND (expr, 0),
17376 (TREE_OPERAND (expr, 1)
17377 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
17378 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
17379 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
17380 if (TREE_CODE (expr) == COMPOUND_EXPR
17381 && !COMPOUND_EXPR_OVERLOADED (expr))
17382 return build2 (COMPOUND_EXPR,
17384 TREE_OPERAND (expr, 0),
17385 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
17387 /* If the type is unknown, it can't really be non-dependent */
17388 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
17390 /* Otherwise, build a NON_DEPENDENT_EXPR.
17392 REFERENCE_TYPEs are not stripped for expressions in templates
17393 because doing so would play havoc with mangling. Consider, for
17396 template <typename T> void f<T& g>() { g(); }
17398 In the body of "f", the expression for "g" will have
17399 REFERENCE_TYPE, even though the standard says that it should
17400 not. The reason is that we must preserve the syntactic form of
17401 the expression so that mangling (say) "f<g>" inside the body of
17402 "f" works out correctly. Therefore, the REFERENCE_TYPE is
17404 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
17407 /* ARGS is a vector of expressions as arguments to a function call.
17408 Replace the arguments with equivalent non-dependent expressions.
17409 This modifies ARGS in place. */
17412 make_args_non_dependent (VEC(tree,gc) *args)
17417 for (ix = 0; VEC_iterate (tree, args, ix, arg); ++ix)
17419 tree newarg = build_non_dependent_expr (arg);
17421 VEC_replace (tree, args, ix, newarg);
17425 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
17426 with a level one deeper than the actual template parms. */
17433 /* ??? Is it worth caching this for multiple autos at the same level? */
17434 au = cxx_make_type (TEMPLATE_TYPE_PARM);
17435 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
17436 TYPE_DECL, get_identifier ("auto"), au);
17437 TYPE_STUB_DECL (au) = TYPE_NAME (au);
17438 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
17439 (0, processing_template_decl + 1, processing_template_decl + 1,
17440 TYPE_NAME (au), NULL_TREE);
17441 TYPE_CANONICAL (au) = canonical_type_parameter (au);
17442 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
17443 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
17448 /* Replace auto in TYPE with std::initializer_list<auto>. */
17451 listify_autos (tree type, tree auto_node)
17453 tree std_init_list = namespace_binding
17454 (get_identifier ("initializer_list"), std_node);
17457 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
17459 error ("deducing auto from brace-enclosed initializer list requires "
17460 "#include <initializer_list>");
17461 return error_mark_node;
17463 argvec = make_tree_vec (1);
17464 TREE_VEC_ELT (argvec, 0) = auto_node;
17465 init_auto = lookup_template_class (std_init_list, argvec, NULL_TREE,
17466 NULL_TREE, 0, tf_warning_or_error);
17468 TREE_VEC_ELT (argvec, 0) = init_auto;
17469 if (processing_template_decl)
17470 argvec = add_to_template_args (current_template_args (), argvec);
17471 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
17474 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
17475 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
17478 do_auto_deduction (tree type, tree init, tree auto_node)
17480 tree parms, tparms, targs;
17484 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
17485 with either a new invented type template parameter U or, if the
17486 initializer is a braced-init-list (8.5.4), with
17487 std::initializer_list<U>. */
17488 if (BRACE_ENCLOSED_INITIALIZER_P (init))
17489 type = listify_autos (type, auto_node);
17491 parms = build_tree_list (NULL_TREE, type);
17493 tparms = make_tree_vec (1);
17494 targs = make_tree_vec (1);
17495 TREE_VEC_ELT (tparms, 0)
17496 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
17497 val = type_unification_real (tparms, targs, parms, args, 1, 0,
17498 DEDUCE_CALL, LOOKUP_NORMAL);
17501 error ("unable to deduce %qT from %qE", type, init);
17502 return error_mark_node;
17505 if (processing_template_decl)
17506 targs = add_to_template_args (current_template_args (), targs);
17507 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
17510 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
17514 splice_late_return_type (tree type, tree late_return_type)
17518 if (late_return_type == NULL_TREE)
17520 argvec = make_tree_vec (1);
17521 TREE_VEC_ELT (argvec, 0) = late_return_type;
17522 if (processing_template_decl)
17523 argvec = add_to_template_args (current_template_args (), argvec);
17524 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
17527 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
17530 is_auto (const_tree type)
17532 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17533 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
17539 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
17540 appear as a type-specifier for the declaration in question, we don't
17541 have to look through the whole type. */
17544 type_uses_auto (tree type)
17546 enum tree_code code;
17547 if (is_auto (type))
17550 code = TREE_CODE (type);
17552 if (code == POINTER_TYPE || code == REFERENCE_TYPE
17553 || code == OFFSET_TYPE || code == FUNCTION_TYPE
17554 || code == METHOD_TYPE || code == ARRAY_TYPE)
17555 return type_uses_auto (TREE_TYPE (type));
17557 if (TYPE_PTRMEMFUNC_P (type))
17558 return type_uses_auto (TREE_TYPE (TREE_TYPE
17559 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
17564 /* For a given template T, return the list of typedefs referenced
17565 in T for which access check is needed at T instantiation time.
17566 T is either a FUNCTION_DECL or a RECORD_TYPE.
17567 Those typedefs were added to T by the function
17568 append_type_to_template_for_access_check. */
17571 get_types_needing_access_check (tree t)
17573 tree ti, result = NULL_TREE;
17575 if (!t || t == error_mark_node)
17578 if (!(ti = get_template_info (t)))
17581 if (CLASS_TYPE_P (t)
17582 || TREE_CODE (t) == FUNCTION_DECL)
17584 if (!TI_TEMPLATE (ti))
17587 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
17593 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
17594 tied to T. That list of typedefs will be access checked at
17595 T instantiation time.
17596 T is either a FUNCTION_DECL or a RECORD_TYPE.
17597 TYPE_DECL is a TYPE_DECL node representing a typedef.
17598 SCOPE is the scope through which TYPE_DECL is accessed.
17600 This function is a subroutine of
17601 append_type_to_template_for_access_check. */
17604 append_type_to_template_for_access_check_1 (tree t,
17610 if (!t || t == error_mark_node)
17613 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
17614 || CLASS_TYPE_P (t))
17616 && TREE_CODE (type_decl) == TYPE_DECL
17619 if (!(ti = get_template_info (t)))
17622 gcc_assert (TI_TEMPLATE (ti));
17624 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti) =
17625 tree_cons (type_decl, scope, TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti));
17628 /* Append TYPE_DECL to the template TEMPL.
17629 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
17630 At TEMPL instanciation time, TYPE_DECL will be checked to see
17631 if it can be accessed through SCOPE.
17633 e.g. consider the following code snippet:
17640 template<class U> struct S
17647 At S<char> instantiation time, we need to check the access of C::myint
17648 In other words, we need to check the access of the myint typedef through
17649 the C scope. For that purpose, this function will add the myint typedef
17650 and the scope C through which its being accessed to a list of typedefs
17651 tied to the template S. That list will be walked at template instantiation
17652 time and access check performed on each typedefs it contains.
17653 Note that this particular code snippet should yield an error because
17654 myint is private to C. */
17657 append_type_to_template_for_access_check (tree templ,
17663 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
17665 /* Make sure we don't append the type to the template twice. */
17666 for (node = get_types_needing_access_check (templ);
17668 node = TREE_CHAIN (node))
17670 tree decl = TREE_PURPOSE (node);
17671 tree type_scope = TREE_VALUE (node);
17673 if (decl == type_decl && type_scope == scope)
17677 append_type_to_template_for_access_check_1 (templ, type_decl, scope);
17680 /* Set up the hash tables for template instantiations. */
17683 init_template_processing (void)
17685 decl_specializations = htab_create_ggc (37,
17686 hash_specialization,
17687 eq_specializations,
17689 type_specializations = htab_create_ggc (37,
17690 hash_specialization,
17691 eq_specializations,
17695 #include "gt-cp-pt.h"