cp-gimplify.c (cp_genericize_r): Use VAR_OR_FUNCTION_DECL_P.
[official-gcc.git] / gcc / cp / pt.c
blobbb690c5009ff97bcb744d8176474ba3fa0fcb9fd
1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992-2013 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
27 #include "config.h"
28 #include "system.h"
29 #include "coretypes.h"
30 #include "tm.h"
31 #include "tree.h"
32 #include "intl.h"
33 #include "pointer-set.h"
34 #include "flags.h"
35 #include "cp-tree.h"
36 #include "c-family/c-common.h"
37 #include "c-family/c-objc.h"
38 #include "cp-objcp-common.h"
39 #include "tree-inline.h"
40 #include "decl.h"
41 #include "toplev.h"
42 #include "timevar.h"
43 #include "tree-iterator.h"
45 /* The type of functions taking a tree, and some additional data, and
46 returning an int. */
47 typedef int (*tree_fn_t) (tree, void*);
49 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
50 instantiations have been deferred, either because their definitions
51 were not yet available, or because we were putting off doing the work. */
52 struct GTY ((chain_next ("%h.next"))) pending_template {
53 struct pending_template *next;
54 struct tinst_level *tinst;
57 static GTY(()) struct pending_template *pending_templates;
58 static GTY(()) struct pending_template *last_pending_template;
60 int processing_template_parmlist;
61 static int template_header_count;
63 static GTY(()) tree saved_trees;
64 static vec<int> inline_parm_levels;
66 static GTY(()) struct tinst_level *current_tinst_level;
68 static GTY(()) tree saved_access_scope;
70 /* Live only within one (recursive) call to tsubst_expr. We use
71 this to pass the statement expression node from the STMT_EXPR
72 to the EXPR_STMT that is its result. */
73 static tree cur_stmt_expr;
75 /* A map from local variable declarations in the body of the template
76 presently being instantiated to the corresponding instantiated
77 local variables. */
78 static struct pointer_map_t *local_specializations;
80 /* True if we've recursed into fn_type_unification too many times. */
81 static bool excessive_deduction_depth;
83 typedef struct GTY(()) spec_entry
85 tree tmpl;
86 tree args;
87 tree spec;
88 } spec_entry;
90 static GTY ((param_is (spec_entry)))
91 htab_t decl_specializations;
93 static GTY ((param_is (spec_entry)))
94 htab_t type_specializations;
96 /* Contains canonical template parameter types. The vector is indexed by
97 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
98 TREE_LIST, whose TREE_VALUEs contain the canonical template
99 parameters of various types and levels. */
100 static GTY(()) vec<tree, va_gc> *canonical_template_parms;
102 #define UNIFY_ALLOW_NONE 0
103 #define UNIFY_ALLOW_MORE_CV_QUAL 1
104 #define UNIFY_ALLOW_LESS_CV_QUAL 2
105 #define UNIFY_ALLOW_DERIVED 4
106 #define UNIFY_ALLOW_INTEGER 8
107 #define UNIFY_ALLOW_OUTER_LEVEL 16
108 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
109 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
111 enum template_base_result {
112 tbr_incomplete_type,
113 tbr_ambiguous_baseclass,
114 tbr_success
117 static void push_access_scope (tree);
118 static void pop_access_scope (tree);
119 static bool resolve_overloaded_unification (tree, tree, tree, tree,
120 unification_kind_t, int,
121 bool);
122 static int try_one_overload (tree, tree, tree, tree, tree,
123 unification_kind_t, int, bool, bool);
124 static int unify (tree, tree, tree, tree, int, bool);
125 static void add_pending_template (tree);
126 static tree reopen_tinst_level (struct tinst_level *);
127 static tree tsubst_initializer_list (tree, tree);
128 static tree get_class_bindings (tree, tree, tree, tree);
129 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
130 bool, bool);
131 static tree coerce_innermost_template_parms (tree, tree, tree, tsubst_flags_t,
132 bool, bool);
133 static void tsubst_enum (tree, tree, tree);
134 static tree add_to_template_args (tree, tree);
135 static tree add_outermost_template_args (tree, tree);
136 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
137 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
138 tree);
139 static int type_unification_real (tree, tree, tree, const tree *,
140 unsigned int, int, unification_kind_t, int,
141 bool);
142 static void note_template_header (int);
143 static tree convert_nontype_argument_function (tree, tree);
144 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
145 static tree convert_template_argument (tree, tree, tree,
146 tsubst_flags_t, int, tree);
147 static int for_each_template_parm (tree, tree_fn_t, void*,
148 struct pointer_set_t*, bool);
149 static tree expand_template_argument_pack (tree);
150 static tree build_template_parm_index (int, int, int, tree, tree);
151 static bool inline_needs_template_parms (tree);
152 static void push_inline_template_parms_recursive (tree, int);
153 static tree retrieve_local_specialization (tree);
154 static void register_local_specialization (tree, tree);
155 static hashval_t hash_specialization (const void *p);
156 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
157 static int mark_template_parm (tree, void *);
158 static int template_parm_this_level_p (tree, void *);
159 static tree tsubst_friend_function (tree, tree);
160 static tree tsubst_friend_class (tree, tree);
161 static int can_complete_type_without_circularity (tree);
162 static tree get_bindings (tree, tree, tree, bool);
163 static int template_decl_level (tree);
164 static int check_cv_quals_for_unify (int, tree, tree);
165 static void template_parm_level_and_index (tree, int*, int*);
166 static int unify_pack_expansion (tree, tree, tree,
167 tree, unification_kind_t, bool, bool);
168 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
169 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
170 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
171 static void regenerate_decl_from_template (tree, tree);
172 static tree most_specialized_class (tree, tree, tsubst_flags_t);
173 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
174 static tree tsubst_arg_types (tree, tree, tree, tsubst_flags_t, tree);
175 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
176 static bool check_specialization_scope (void);
177 static tree process_partial_specialization (tree);
178 static void set_current_access_from_decl (tree);
179 static enum template_base_result get_template_base (tree, tree, tree, tree,
180 bool , tree *);
181 static tree try_class_unification (tree, tree, tree, tree, bool);
182 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
183 tree, tree);
184 static bool template_template_parm_bindings_ok_p (tree, tree);
185 static int template_args_equal (tree, tree);
186 static void tsubst_default_arguments (tree);
187 static tree for_each_template_parm_r (tree *, int *, void *);
188 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
189 static void copy_default_args_to_explicit_spec (tree);
190 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
191 static bool dependent_template_arg_p (tree);
192 static bool any_template_arguments_need_structural_equality_p (tree);
193 static bool dependent_type_p_r (tree);
194 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
195 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
196 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
197 static tree tsubst_decl (tree, tree, tsubst_flags_t);
198 static void perform_typedefs_access_check (tree tmpl, tree targs);
199 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
200 location_t);
201 static tree listify (tree);
202 static tree listify_autos (tree, tree);
203 static tree template_parm_to_arg (tree t);
204 static tree current_template_args (void);
205 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
206 static tree instantiate_alias_template (tree, tree, tsubst_flags_t);
208 /* Make the current scope suitable for access checking when we are
209 processing T. T can be FUNCTION_DECL for instantiated function
210 template, VAR_DECL for static member variable, or TYPE_DECL for
211 alias template (needed by instantiate_decl). */
213 static void
214 push_access_scope (tree t)
216 gcc_assert (VAR_OR_FUNCTION_DECL_P (t)
217 || TREE_CODE (t) == TYPE_DECL);
219 if (DECL_FRIEND_CONTEXT (t))
220 push_nested_class (DECL_FRIEND_CONTEXT (t));
221 else if (DECL_CLASS_SCOPE_P (t))
222 push_nested_class (DECL_CONTEXT (t));
223 else
224 push_to_top_level ();
226 if (TREE_CODE (t) == FUNCTION_DECL)
228 saved_access_scope = tree_cons
229 (NULL_TREE, current_function_decl, saved_access_scope);
230 current_function_decl = t;
234 /* Restore the scope set up by push_access_scope. T is the node we
235 are processing. */
237 static void
238 pop_access_scope (tree t)
240 if (TREE_CODE (t) == FUNCTION_DECL)
242 current_function_decl = TREE_VALUE (saved_access_scope);
243 saved_access_scope = TREE_CHAIN (saved_access_scope);
246 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
247 pop_nested_class ();
248 else
249 pop_from_top_level ();
252 /* Do any processing required when DECL (a member template
253 declaration) is finished. Returns the TEMPLATE_DECL corresponding
254 to DECL, unless it is a specialization, in which case the DECL
255 itself is returned. */
257 tree
258 finish_member_template_decl (tree decl)
260 if (decl == error_mark_node)
261 return error_mark_node;
263 gcc_assert (DECL_P (decl));
265 if (TREE_CODE (decl) == TYPE_DECL)
267 tree type;
269 type = TREE_TYPE (decl);
270 if (type == error_mark_node)
271 return error_mark_node;
272 if (MAYBE_CLASS_TYPE_P (type)
273 && CLASSTYPE_TEMPLATE_INFO (type)
274 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
276 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
277 check_member_template (tmpl);
278 return tmpl;
280 return NULL_TREE;
282 else if (TREE_CODE (decl) == FIELD_DECL)
283 error ("data member %qD cannot be a member template", decl);
284 else if (DECL_TEMPLATE_INFO (decl))
286 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
288 check_member_template (DECL_TI_TEMPLATE (decl));
289 return DECL_TI_TEMPLATE (decl);
291 else
292 return decl;
294 else
295 error ("invalid member template declaration %qD", decl);
297 return error_mark_node;
300 /* Create a template info node. */
302 tree
303 build_template_info (tree template_decl, tree template_args)
305 tree result = make_node (TEMPLATE_INFO);
306 TI_TEMPLATE (result) = template_decl;
307 TI_ARGS (result) = template_args;
308 return result;
311 /* Return the template info node corresponding to T, whatever T is. */
313 tree
314 get_template_info (const_tree t)
316 tree tinfo = NULL_TREE;
318 if (!t || t == error_mark_node)
319 return NULL;
321 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
322 tinfo = DECL_TEMPLATE_INFO (t);
324 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
325 t = TREE_TYPE (t);
327 if (TAGGED_TYPE_P (t))
328 tinfo = TYPE_TEMPLATE_INFO (t);
329 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
330 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
332 return tinfo;
335 /* Returns the template nesting level of the indicated class TYPE.
337 For example, in:
338 template <class T>
339 struct A
341 template <class U>
342 struct B {};
345 A<T>::B<U> has depth two, while A<T> has depth one.
346 Both A<T>::B<int> and A<int>::B<U> have depth one, if
347 they are instantiations, not specializations.
349 This function is guaranteed to return 0 if passed NULL_TREE so
350 that, for example, `template_class_depth (current_class_type)' is
351 always safe. */
354 template_class_depth (tree type)
356 int depth;
358 for (depth = 0;
359 type && TREE_CODE (type) != NAMESPACE_DECL;
360 type = (TREE_CODE (type) == FUNCTION_DECL)
361 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
363 tree tinfo = get_template_info (type);
365 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
366 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
367 ++depth;
370 return depth;
373 /* Subroutine of maybe_begin_member_template_processing.
374 Returns true if processing DECL needs us to push template parms. */
376 static bool
377 inline_needs_template_parms (tree decl)
379 if (! DECL_TEMPLATE_INFO (decl))
380 return false;
382 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
383 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
386 /* Subroutine of maybe_begin_member_template_processing.
387 Push the template parms in PARMS, starting from LEVELS steps into the
388 chain, and ending at the beginning, since template parms are listed
389 innermost first. */
391 static void
392 push_inline_template_parms_recursive (tree parmlist, int levels)
394 tree parms = TREE_VALUE (parmlist);
395 int i;
397 if (levels > 1)
398 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
400 ++processing_template_decl;
401 current_template_parms
402 = tree_cons (size_int (processing_template_decl),
403 parms, current_template_parms);
404 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
406 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
407 NULL);
408 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
410 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
412 if (parm == error_mark_node)
413 continue;
415 gcc_assert (DECL_P (parm));
417 switch (TREE_CODE (parm))
419 case TYPE_DECL:
420 case TEMPLATE_DECL:
421 pushdecl (parm);
422 break;
424 case PARM_DECL:
426 /* Make a CONST_DECL as is done in process_template_parm.
427 It is ugly that we recreate this here; the original
428 version built in process_template_parm is no longer
429 available. */
430 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
431 CONST_DECL, DECL_NAME (parm),
432 TREE_TYPE (parm));
433 DECL_ARTIFICIAL (decl) = 1;
434 TREE_CONSTANT (decl) = 1;
435 TREE_READONLY (decl) = 1;
436 DECL_INITIAL (decl) = DECL_INITIAL (parm);
437 SET_DECL_TEMPLATE_PARM_P (decl);
438 pushdecl (decl);
440 break;
442 default:
443 gcc_unreachable ();
448 /* Restore the template parameter context for a member template or
449 a friend template defined in a class definition. */
451 void
452 maybe_begin_member_template_processing (tree decl)
454 tree parms;
455 int levels = 0;
457 if (inline_needs_template_parms (decl))
459 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
460 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
462 if (DECL_TEMPLATE_SPECIALIZATION (decl))
464 --levels;
465 parms = TREE_CHAIN (parms);
468 push_inline_template_parms_recursive (parms, levels);
471 /* Remember how many levels of template parameters we pushed so that
472 we can pop them later. */
473 inline_parm_levels.safe_push (levels);
476 /* Undo the effects of maybe_begin_member_template_processing. */
478 void
479 maybe_end_member_template_processing (void)
481 int i;
482 int last;
484 if (inline_parm_levels.length () == 0)
485 return;
487 last = inline_parm_levels.pop ();
488 for (i = 0; i < last; ++i)
490 --processing_template_decl;
491 current_template_parms = TREE_CHAIN (current_template_parms);
492 poplevel (0, 0, 0);
496 /* Return a new template argument vector which contains all of ARGS,
497 but has as its innermost set of arguments the EXTRA_ARGS. */
499 static tree
500 add_to_template_args (tree args, tree extra_args)
502 tree new_args;
503 int extra_depth;
504 int i;
505 int j;
507 if (args == NULL_TREE || extra_args == error_mark_node)
508 return extra_args;
510 extra_depth = TMPL_ARGS_DEPTH (extra_args);
511 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
513 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
514 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
516 for (j = 1; j <= extra_depth; ++j, ++i)
517 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
519 return new_args;
522 /* Like add_to_template_args, but only the outermost ARGS are added to
523 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
524 (EXTRA_ARGS) levels are added. This function is used to combine
525 the template arguments from a partial instantiation with the
526 template arguments used to attain the full instantiation from the
527 partial instantiation. */
529 static tree
530 add_outermost_template_args (tree args, tree extra_args)
532 tree new_args;
534 /* If there are more levels of EXTRA_ARGS than there are ARGS,
535 something very fishy is going on. */
536 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
538 /* If *all* the new arguments will be the EXTRA_ARGS, just return
539 them. */
540 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
541 return extra_args;
543 /* For the moment, we make ARGS look like it contains fewer levels. */
544 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
546 new_args = add_to_template_args (args, extra_args);
548 /* Now, we restore ARGS to its full dimensions. */
549 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
551 return new_args;
554 /* Return the N levels of innermost template arguments from the ARGS. */
556 tree
557 get_innermost_template_args (tree args, int n)
559 tree new_args;
560 int extra_levels;
561 int i;
563 gcc_assert (n >= 0);
565 /* If N is 1, just return the innermost set of template arguments. */
566 if (n == 1)
567 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
569 /* If we're not removing anything, just return the arguments we were
570 given. */
571 extra_levels = TMPL_ARGS_DEPTH (args) - n;
572 gcc_assert (extra_levels >= 0);
573 if (extra_levels == 0)
574 return args;
576 /* Make a new set of arguments, not containing the outer 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 + extra_levels));
582 return new_args;
585 /* The inverse of get_innermost_template_args: Return all but the innermost
586 EXTRA_LEVELS levels of template arguments from the ARGS. */
588 static tree
589 strip_innermost_template_args (tree args, int extra_levels)
591 tree new_args;
592 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
593 int i;
595 gcc_assert (n >= 0);
597 /* If N is 1, just return the outermost set of template arguments. */
598 if (n == 1)
599 return TMPL_ARGS_LEVEL (args, 1);
601 /* If we're not removing anything, just return the arguments we were
602 given. */
603 gcc_assert (extra_levels >= 0);
604 if (extra_levels == 0)
605 return args;
607 /* Make a new set of arguments, not containing the inner arguments. */
608 new_args = make_tree_vec (n);
609 for (i = 1; i <= n; ++i)
610 SET_TMPL_ARGS_LEVEL (new_args, i,
611 TMPL_ARGS_LEVEL (args, i));
613 return new_args;
616 /* We've got a template header coming up; push to a new level for storing
617 the parms. */
619 void
620 begin_template_parm_list (void)
622 /* We use a non-tag-transparent scope here, which causes pushtag to
623 put tags in this scope, rather than in the enclosing class or
624 namespace scope. This is the right thing, since we want
625 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
626 global template class, push_template_decl handles putting the
627 TEMPLATE_DECL into top-level scope. For a nested template class,
628 e.g.:
630 template <class T> struct S1 {
631 template <class T> struct S2 {};
634 pushtag contains special code to call pushdecl_with_scope on the
635 TEMPLATE_DECL for S2. */
636 begin_scope (sk_template_parms, NULL);
637 ++processing_template_decl;
638 ++processing_template_parmlist;
639 note_template_header (0);
642 /* This routine is called when a specialization is declared. If it is
643 invalid to declare a specialization here, an error is reported and
644 false is returned, otherwise this routine will return true. */
646 static bool
647 check_specialization_scope (void)
649 tree scope = current_scope ();
651 /* [temp.expl.spec]
653 An explicit specialization shall be declared in the namespace of
654 which the template is a member, or, for member templates, in the
655 namespace of which the enclosing class or enclosing class
656 template is a member. An explicit specialization of a member
657 function, member class or static data member of a class template
658 shall be declared in the namespace of which the class template
659 is a member. */
660 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
662 error ("explicit specialization in non-namespace scope %qD", scope);
663 return false;
666 /* [temp.expl.spec]
668 In an explicit specialization declaration for a member of a class
669 template or a member template that appears in namespace scope,
670 the member template and some of its enclosing class templates may
671 remain unspecialized, except that the declaration shall not
672 explicitly specialize a class member template if its enclosing
673 class templates are not explicitly specialized as well. */
674 if (current_template_parms)
676 error ("enclosing class templates are not explicitly specialized");
677 return false;
680 return true;
683 /* We've just seen template <>. */
685 bool
686 begin_specialization (void)
688 begin_scope (sk_template_spec, NULL);
689 note_template_header (1);
690 return check_specialization_scope ();
693 /* Called at then end of processing a declaration preceded by
694 template<>. */
696 void
697 end_specialization (void)
699 finish_scope ();
700 reset_specialization ();
703 /* Any template <>'s that we have seen thus far are not referring to a
704 function specialization. */
706 void
707 reset_specialization (void)
709 processing_specialization = 0;
710 template_header_count = 0;
713 /* We've just seen a template header. If SPECIALIZATION is nonzero,
714 it was of the form template <>. */
716 static void
717 note_template_header (int specialization)
719 processing_specialization = specialization;
720 template_header_count++;
723 /* We're beginning an explicit instantiation. */
725 void
726 begin_explicit_instantiation (void)
728 gcc_assert (!processing_explicit_instantiation);
729 processing_explicit_instantiation = true;
733 void
734 end_explicit_instantiation (void)
736 gcc_assert (processing_explicit_instantiation);
737 processing_explicit_instantiation = false;
740 /* An explicit specialization or partial specialization of TMPL is being
741 declared. Check that the namespace in which the specialization is
742 occurring is permissible. Returns false iff it is invalid to
743 specialize TMPL in the current namespace. */
745 static bool
746 check_specialization_namespace (tree tmpl)
748 tree tpl_ns = decl_namespace_context (tmpl);
750 /* [tmpl.expl.spec]
752 An explicit specialization shall be declared in the namespace of
753 which the template is a member, or, for member templates, in the
754 namespace of which the enclosing class or enclosing class
755 template is a member. An explicit specialization of a member
756 function, member class or static data member of a class template
757 shall be declared in the namespace of which the class template is
758 a member. */
759 if (current_scope() != DECL_CONTEXT (tmpl)
760 && !at_namespace_scope_p ())
762 error ("specialization of %qD must appear at namespace scope", tmpl);
763 return false;
765 if (is_associated_namespace (current_namespace, tpl_ns))
766 /* Same or super-using namespace. */
767 return true;
768 else
770 permerror (input_location, "specialization of %qD in different namespace", tmpl);
771 permerror (input_location, " from definition of %q+#D", tmpl);
772 return false;
776 /* SPEC is an explicit instantiation. Check that it is valid to
777 perform this explicit instantiation in the current namespace. */
779 static void
780 check_explicit_instantiation_namespace (tree spec)
782 tree ns;
784 /* DR 275: An explicit instantiation shall appear in an enclosing
785 namespace of its template. */
786 ns = decl_namespace_context (spec);
787 if (!is_ancestor (current_namespace, ns))
788 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
789 "(which does not enclose namespace %qD)",
790 spec, current_namespace, ns);
793 /* The TYPE is being declared. If it is a template type, that means it
794 is a partial specialization. Do appropriate error-checking. */
796 tree
797 maybe_process_partial_specialization (tree type)
799 tree context;
801 if (type == error_mark_node)
802 return error_mark_node;
804 /* A lambda that appears in specialization context is not itself a
805 specialization. */
806 if (CLASS_TYPE_P (type) && CLASSTYPE_LAMBDA_EXPR (type))
807 return type;
809 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
811 error ("name of class shadows template template parameter %qD",
812 TYPE_NAME (type));
813 return error_mark_node;
816 context = TYPE_CONTEXT (type);
818 if (TYPE_ALIAS_P (type))
820 if (TYPE_TEMPLATE_INFO (type)
821 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
822 error ("specialization of alias template %qD",
823 TYPE_TI_TEMPLATE (type));
824 else
825 error ("explicit specialization of non-template %qT", type);
826 return error_mark_node;
828 else if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
830 /* This is for ordinary explicit specialization and partial
831 specialization of a template class such as:
833 template <> class C<int>;
837 template <class T> class C<T*>;
839 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
841 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
842 && !COMPLETE_TYPE_P (type))
844 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
845 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
846 DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)) = input_location;
847 if (processing_template_decl)
849 if (push_template_decl (TYPE_MAIN_DECL (type))
850 == error_mark_node)
851 return error_mark_node;
854 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
855 error ("specialization of %qT after instantiation", type);
856 else if (errorcount && !processing_specialization
857 && CLASSTYPE_TEMPLATE_SPECIALIZATION (type)
858 && !uses_template_parms (CLASSTYPE_TI_ARGS (type)))
859 /* Trying to define a specialization either without a template<> header
860 or in an inappropriate place. We've already given an error, so just
861 bail now so we don't actually define the specialization. */
862 return error_mark_node;
864 else if (CLASS_TYPE_P (type)
865 && !CLASSTYPE_USE_TEMPLATE (type)
866 && CLASSTYPE_TEMPLATE_INFO (type)
867 && context && CLASS_TYPE_P (context)
868 && CLASSTYPE_TEMPLATE_INFO (context))
870 /* This is for an explicit specialization of member class
871 template according to [temp.expl.spec/18]:
873 template <> template <class U> class C<int>::D;
875 The context `C<int>' must be an implicit instantiation.
876 Otherwise this is just a member class template declared
877 earlier like:
879 template <> class C<int> { template <class U> class D; };
880 template <> template <class U> class C<int>::D;
882 In the first case, `C<int>::D' is a specialization of `C<T>::D'
883 while in the second case, `C<int>::D' is a primary template
884 and `C<T>::D' may not exist. */
886 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
887 && !COMPLETE_TYPE_P (type))
889 tree t;
890 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
892 if (current_namespace
893 != decl_namespace_context (tmpl))
895 permerror (input_location, "specializing %q#T in different namespace", type);
896 permerror (input_location, " from definition of %q+#D", tmpl);
899 /* Check for invalid specialization after instantiation:
901 template <> template <> class C<int>::D<int>;
902 template <> template <class U> class C<int>::D; */
904 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
905 t; t = TREE_CHAIN (t))
907 tree inst = TREE_VALUE (t);
908 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
910 /* We already have a full specialization of this partial
911 instantiation. Reassign it to the new member
912 specialization template. */
913 spec_entry elt;
914 spec_entry *entry;
915 void **slot;
917 elt.tmpl = most_general_template (tmpl);
918 elt.args = CLASSTYPE_TI_ARGS (inst);
919 elt.spec = inst;
921 htab_remove_elt (type_specializations, &elt);
923 elt.tmpl = tmpl;
924 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
926 slot = htab_find_slot (type_specializations, &elt, INSERT);
927 entry = ggc_alloc_spec_entry ();
928 *entry = elt;
929 *slot = entry;
931 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
932 /* But if we've had an implicit instantiation, that's a
933 problem ([temp.expl.spec]/6). */
934 error ("specialization %qT after instantiation %qT",
935 type, inst);
938 /* Mark TYPE as a specialization. And as a result, we only
939 have one level of template argument for the innermost
940 class template. */
941 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
942 DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)) = input_location;
943 CLASSTYPE_TI_ARGS (type)
944 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
947 else if (processing_specialization)
949 /* Someday C++0x may allow for enum template specialization. */
950 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
951 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
952 pedwarn (input_location, OPT_Wpedantic, "template specialization "
953 "of %qD not allowed by ISO C++", type);
954 else
956 error ("explicit specialization of non-template %qT", type);
957 return error_mark_node;
961 return type;
964 /* Returns nonzero if we can optimize the retrieval of specializations
965 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
966 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
968 static inline bool
969 optimize_specialization_lookup_p (tree tmpl)
971 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
972 && DECL_CLASS_SCOPE_P (tmpl)
973 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
974 parameter. */
975 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
976 /* The optimized lookup depends on the fact that the
977 template arguments for the member function template apply
978 purely to the containing class, which is not true if the
979 containing class is an explicit or partial
980 specialization. */
981 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
982 && !DECL_MEMBER_TEMPLATE_P (tmpl)
983 && !DECL_CONV_FN_P (tmpl)
984 /* It is possible to have a template that is not a member
985 template and is not a member of a template class:
987 template <typename T>
988 struct S { friend A::f(); };
990 Here, the friend function is a template, but the context does
991 not have template information. The optimized lookup relies
992 on having ARGS be the template arguments for both the class
993 and the function template. */
994 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
997 /* Retrieve the specialization (in the sense of [temp.spec] - a
998 specialization is either an instantiation or an explicit
999 specialization) of TMPL for the given template ARGS. If there is
1000 no such specialization, return NULL_TREE. The ARGS are a vector of
1001 arguments, or a vector of vectors of arguments, in the case of
1002 templates with more than one level of parameters.
1004 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1005 then we search for a partial specialization matching ARGS. This
1006 parameter is ignored if TMPL is not a class template. */
1008 static tree
1009 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1011 if (tmpl == NULL_TREE)
1012 return NULL_TREE;
1014 if (args == error_mark_node)
1015 return NULL_TREE;
1017 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1019 /* There should be as many levels of arguments as there are
1020 levels of parameters. */
1021 gcc_assert (TMPL_ARGS_DEPTH (args)
1022 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
1024 if (optimize_specialization_lookup_p (tmpl))
1026 tree class_template;
1027 tree class_specialization;
1028 vec<tree, va_gc> *methods;
1029 tree fns;
1030 int idx;
1032 /* The template arguments actually apply to the containing
1033 class. Find the class specialization with those
1034 arguments. */
1035 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1036 class_specialization
1037 = retrieve_specialization (class_template, args, 0);
1038 if (!class_specialization)
1039 return NULL_TREE;
1040 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1041 for the specialization. */
1042 idx = class_method_index_for_fn (class_specialization, tmpl);
1043 if (idx == -1)
1044 return NULL_TREE;
1045 /* Iterate through the methods with the indicated name, looking
1046 for the one that has an instance of TMPL. */
1047 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1048 for (fns = (*methods)[idx]; fns; fns = OVL_NEXT (fns))
1050 tree fn = OVL_CURRENT (fns);
1051 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1052 /* using-declarations can add base methods to the method vec,
1053 and we don't want those here. */
1054 && DECL_CONTEXT (fn) == class_specialization)
1055 return fn;
1057 return NULL_TREE;
1059 else
1061 spec_entry *found;
1062 spec_entry elt;
1063 htab_t specializations;
1065 elt.tmpl = tmpl;
1066 elt.args = args;
1067 elt.spec = NULL_TREE;
1069 if (DECL_CLASS_TEMPLATE_P (tmpl))
1070 specializations = type_specializations;
1071 else
1072 specializations = decl_specializations;
1074 if (hash == 0)
1075 hash = hash_specialization (&elt);
1076 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1077 if (found)
1078 return found->spec;
1081 return NULL_TREE;
1084 /* Like retrieve_specialization, but for local declarations. */
1086 static tree
1087 retrieve_local_specialization (tree tmpl)
1089 void **slot;
1091 if (local_specializations == NULL)
1092 return NULL_TREE;
1094 slot = pointer_map_contains (local_specializations, tmpl);
1095 return slot ? (tree) *slot : NULL_TREE;
1098 /* Returns nonzero iff DECL is a specialization of TMPL. */
1101 is_specialization_of (tree decl, tree tmpl)
1103 tree t;
1105 if (TREE_CODE (decl) == FUNCTION_DECL)
1107 for (t = decl;
1108 t != NULL_TREE;
1109 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1110 if (t == tmpl)
1111 return 1;
1113 else
1115 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1117 for (t = TREE_TYPE (decl);
1118 t != NULL_TREE;
1119 t = CLASSTYPE_USE_TEMPLATE (t)
1120 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1121 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1122 return 1;
1125 return 0;
1128 /* Returns nonzero iff DECL is a specialization of friend declaration
1129 FRIEND_DECL according to [temp.friend]. */
1131 bool
1132 is_specialization_of_friend (tree decl, tree friend_decl)
1134 bool need_template = true;
1135 int template_depth;
1137 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1138 || TREE_CODE (decl) == TYPE_DECL);
1140 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1141 of a template class, we want to check if DECL is a specialization
1142 if this. */
1143 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1144 && DECL_TEMPLATE_INFO (friend_decl)
1145 && !DECL_USE_TEMPLATE (friend_decl))
1147 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1148 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1149 need_template = false;
1151 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1152 && !PRIMARY_TEMPLATE_P (friend_decl))
1153 need_template = false;
1155 /* There is nothing to do if this is not a template friend. */
1156 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1157 return false;
1159 if (is_specialization_of (decl, friend_decl))
1160 return true;
1162 /* [temp.friend/6]
1163 A member of a class template may be declared to be a friend of a
1164 non-template class. In this case, the corresponding member of
1165 every specialization of the class template is a friend of the
1166 class granting friendship.
1168 For example, given a template friend declaration
1170 template <class T> friend void A<T>::f();
1172 the member function below is considered a friend
1174 template <> struct A<int> {
1175 void f();
1178 For this type of template friend, TEMPLATE_DEPTH below will be
1179 nonzero. To determine if DECL is a friend of FRIEND, we first
1180 check if the enclosing class is a specialization of another. */
1182 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1183 if (template_depth
1184 && DECL_CLASS_SCOPE_P (decl)
1185 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1186 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1188 /* Next, we check the members themselves. In order to handle
1189 a few tricky cases, such as when FRIEND_DECL's are
1191 template <class T> friend void A<T>::g(T t);
1192 template <class T> template <T t> friend void A<T>::h();
1194 and DECL's are
1196 void A<int>::g(int);
1197 template <int> void A<int>::h();
1199 we need to figure out ARGS, the template arguments from
1200 the context of DECL. This is required for template substitution
1201 of `T' in the function parameter of `g' and template parameter
1202 of `h' in the above examples. Here ARGS corresponds to `int'. */
1204 tree context = DECL_CONTEXT (decl);
1205 tree args = NULL_TREE;
1206 int current_depth = 0;
1208 while (current_depth < template_depth)
1210 if (CLASSTYPE_TEMPLATE_INFO (context))
1212 if (current_depth == 0)
1213 args = TYPE_TI_ARGS (context);
1214 else
1215 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1216 current_depth++;
1218 context = TYPE_CONTEXT (context);
1221 if (TREE_CODE (decl) == FUNCTION_DECL)
1223 bool is_template;
1224 tree friend_type;
1225 tree decl_type;
1226 tree friend_args_type;
1227 tree decl_args_type;
1229 /* Make sure that both DECL and FRIEND_DECL are templates or
1230 non-templates. */
1231 is_template = DECL_TEMPLATE_INFO (decl)
1232 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1233 if (need_template ^ is_template)
1234 return false;
1235 else if (is_template)
1237 /* If both are templates, check template parameter list. */
1238 tree friend_parms
1239 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1240 args, tf_none);
1241 if (!comp_template_parms
1242 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1243 friend_parms))
1244 return false;
1246 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1248 else
1249 decl_type = TREE_TYPE (decl);
1251 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1252 tf_none, NULL_TREE);
1253 if (friend_type == error_mark_node)
1254 return false;
1256 /* Check if return types match. */
1257 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1258 return false;
1260 /* Check if function parameter types match, ignoring the
1261 `this' parameter. */
1262 friend_args_type = TYPE_ARG_TYPES (friend_type);
1263 decl_args_type = TYPE_ARG_TYPES (decl_type);
1264 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1265 friend_args_type = TREE_CHAIN (friend_args_type);
1266 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1267 decl_args_type = TREE_CHAIN (decl_args_type);
1269 return compparms (decl_args_type, friend_args_type);
1271 else
1273 /* DECL is a TYPE_DECL */
1274 bool is_template;
1275 tree decl_type = TREE_TYPE (decl);
1277 /* Make sure that both DECL and FRIEND_DECL are templates or
1278 non-templates. */
1279 is_template
1280 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1281 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1283 if (need_template ^ is_template)
1284 return false;
1285 else if (is_template)
1287 tree friend_parms;
1288 /* If both are templates, check the name of the two
1289 TEMPLATE_DECL's first because is_friend didn't. */
1290 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1291 != DECL_NAME (friend_decl))
1292 return false;
1294 /* Now check template parameter list. */
1295 friend_parms
1296 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1297 args, tf_none);
1298 return comp_template_parms
1299 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1300 friend_parms);
1302 else
1303 return (DECL_NAME (decl)
1304 == DECL_NAME (friend_decl));
1307 return false;
1310 /* Register the specialization SPEC as a specialization of TMPL with
1311 the indicated ARGS. IS_FRIEND indicates whether the specialization
1312 is actually just a friend declaration. Returns SPEC, or an
1313 equivalent prior declaration, if available. */
1315 static tree
1316 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1317 hashval_t hash)
1319 tree fn;
1320 void **slot = NULL;
1321 spec_entry elt;
1323 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1325 if (TREE_CODE (spec) == FUNCTION_DECL
1326 && uses_template_parms (DECL_TI_ARGS (spec)))
1327 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1328 register it; we want the corresponding TEMPLATE_DECL instead.
1329 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1330 the more obvious `uses_template_parms (spec)' to avoid problems
1331 with default function arguments. In particular, given
1332 something like this:
1334 template <class T> void f(T t1, T t = T())
1336 the default argument expression is not substituted for in an
1337 instantiation unless and until it is actually needed. */
1338 return spec;
1340 if (optimize_specialization_lookup_p (tmpl))
1341 /* We don't put these specializations in the hash table, but we might
1342 want to give an error about a mismatch. */
1343 fn = retrieve_specialization (tmpl, args, 0);
1344 else
1346 elt.tmpl = tmpl;
1347 elt.args = args;
1348 elt.spec = spec;
1350 if (hash == 0)
1351 hash = hash_specialization (&elt);
1353 slot =
1354 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1355 if (*slot)
1356 fn = ((spec_entry *) *slot)->spec;
1357 else
1358 fn = NULL_TREE;
1361 /* We can sometimes try to re-register a specialization that we've
1362 already got. In particular, regenerate_decl_from_template calls
1363 duplicate_decls which will update the specialization list. But,
1364 we'll still get called again here anyhow. It's more convenient
1365 to simply allow this than to try to prevent it. */
1366 if (fn == spec)
1367 return spec;
1368 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1370 if (DECL_TEMPLATE_INSTANTIATION (fn))
1372 if (DECL_ODR_USED (fn)
1373 || DECL_EXPLICIT_INSTANTIATION (fn))
1375 error ("specialization of %qD after instantiation",
1376 fn);
1377 return error_mark_node;
1379 else
1381 tree clone;
1382 /* This situation should occur only if the first
1383 specialization is an implicit instantiation, the
1384 second is an explicit specialization, and the
1385 implicit instantiation has not yet been used. That
1386 situation can occur if we have implicitly
1387 instantiated a member function and then specialized
1388 it later.
1390 We can also wind up here if a friend declaration that
1391 looked like an instantiation turns out to be a
1392 specialization:
1394 template <class T> void foo(T);
1395 class S { friend void foo<>(int) };
1396 template <> void foo(int);
1398 We transform the existing DECL in place so that any
1399 pointers to it become pointers to the updated
1400 declaration.
1402 If there was a definition for the template, but not
1403 for the specialization, we want this to look as if
1404 there were no definition, and vice versa. */
1405 DECL_INITIAL (fn) = NULL_TREE;
1406 duplicate_decls (spec, fn, is_friend);
1407 /* The call to duplicate_decls will have applied
1408 [temp.expl.spec]:
1410 An explicit specialization of a function template
1411 is inline only if it is explicitly declared to be,
1412 and independently of whether its function template
1415 to the primary function; now copy the inline bits to
1416 the various clones. */
1417 FOR_EACH_CLONE (clone, fn)
1419 DECL_DECLARED_INLINE_P (clone)
1420 = DECL_DECLARED_INLINE_P (fn);
1421 DECL_SOURCE_LOCATION (clone)
1422 = DECL_SOURCE_LOCATION (fn);
1424 check_specialization_namespace (tmpl);
1426 return fn;
1429 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1431 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1432 /* Dup decl failed, but this is a new definition. Set the
1433 line number so any errors match this new
1434 definition. */
1435 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1437 return fn;
1440 else if (fn)
1441 return duplicate_decls (spec, fn, is_friend);
1443 /* A specialization must be declared in the same namespace as the
1444 template it is specializing. */
1445 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1446 && !check_specialization_namespace (tmpl))
1447 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1449 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1451 spec_entry *entry = ggc_alloc_spec_entry ();
1452 gcc_assert (tmpl && args && spec);
1453 *entry = elt;
1454 *slot = entry;
1455 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1456 && PRIMARY_TEMPLATE_P (tmpl)
1457 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1458 /* TMPL is a forward declaration of a template function; keep a list
1459 of all specializations in case we need to reassign them to a friend
1460 template later in tsubst_friend_function. */
1461 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1462 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1465 return spec;
1468 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1469 TMPL and ARGS members, ignores SPEC. */
1471 int comparing_specializations;
1473 static int
1474 eq_specializations (const void *p1, const void *p2)
1476 const spec_entry *e1 = (const spec_entry *)p1;
1477 const spec_entry *e2 = (const spec_entry *)p2;
1478 int equal;
1480 ++comparing_specializations;
1481 equal = (e1->tmpl == e2->tmpl
1482 && comp_template_args (e1->args, e2->args));
1483 --comparing_specializations;
1485 return equal;
1488 /* Returns a hash for a template TMPL and template arguments ARGS. */
1490 static hashval_t
1491 hash_tmpl_and_args (tree tmpl, tree args)
1493 hashval_t val = DECL_UID (tmpl);
1494 return iterative_hash_template_arg (args, val);
1497 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1498 ignoring SPEC. */
1500 static hashval_t
1501 hash_specialization (const void *p)
1503 const spec_entry *e = (const spec_entry *)p;
1504 return hash_tmpl_and_args (e->tmpl, e->args);
1507 /* Recursively calculate a hash value for a template argument ARG, for use
1508 in the hash tables of template specializations. */
1510 hashval_t
1511 iterative_hash_template_arg (tree arg, hashval_t val)
1513 unsigned HOST_WIDE_INT i;
1514 enum tree_code code;
1515 char tclass;
1517 if (arg == NULL_TREE)
1518 return iterative_hash_object (arg, val);
1520 if (!TYPE_P (arg))
1521 STRIP_NOPS (arg);
1523 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1524 /* We can get one of these when re-hashing a previous entry in the middle
1525 of substituting into a pack expansion. Just look through it. */
1526 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1528 code = TREE_CODE (arg);
1529 tclass = TREE_CODE_CLASS (code);
1531 val = iterative_hash_object (code, val);
1533 switch (code)
1535 case ERROR_MARK:
1536 return val;
1538 case IDENTIFIER_NODE:
1539 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1541 case TREE_VEC:
1543 int i, len = TREE_VEC_LENGTH (arg);
1544 for (i = 0; i < len; ++i)
1545 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1546 return val;
1549 case TYPE_PACK_EXPANSION:
1550 case EXPR_PACK_EXPANSION:
1551 val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1552 return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val);
1554 case TYPE_ARGUMENT_PACK:
1555 case NONTYPE_ARGUMENT_PACK:
1556 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1558 case TREE_LIST:
1559 for (; arg; arg = TREE_CHAIN (arg))
1560 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1561 return val;
1563 case OVERLOAD:
1564 for (; arg; arg = OVL_NEXT (arg))
1565 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1566 return val;
1568 case CONSTRUCTOR:
1570 tree field, value;
1571 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1573 val = iterative_hash_template_arg (field, val);
1574 val = iterative_hash_template_arg (value, val);
1576 return val;
1579 case PARM_DECL:
1580 if (!DECL_ARTIFICIAL (arg))
1582 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1583 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1585 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1587 case TARGET_EXPR:
1588 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1590 case PTRMEM_CST:
1591 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1592 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1594 case TEMPLATE_PARM_INDEX:
1595 val = iterative_hash_template_arg
1596 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1597 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1598 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1600 case TRAIT_EXPR:
1601 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1602 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1603 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1605 case BASELINK:
1606 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1607 val);
1608 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1609 val);
1611 case MODOP_EXPR:
1612 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1613 code = TREE_CODE (TREE_OPERAND (arg, 1));
1614 val = iterative_hash_object (code, val);
1615 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1617 case LAMBDA_EXPR:
1618 /* A lambda can't appear in a template arg, but don't crash on
1619 erroneous input. */
1620 gcc_assert (seen_error ());
1621 return val;
1623 case CAST_EXPR:
1624 case IMPLICIT_CONV_EXPR:
1625 case STATIC_CAST_EXPR:
1626 case REINTERPRET_CAST_EXPR:
1627 case CONST_CAST_EXPR:
1628 case DYNAMIC_CAST_EXPR:
1629 case NEW_EXPR:
1630 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1631 /* Now hash operands as usual. */
1632 break;
1634 default:
1635 break;
1638 switch (tclass)
1640 case tcc_type:
1641 if (TYPE_CANONICAL (arg))
1642 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1643 val);
1644 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1645 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1646 /* Otherwise just compare the types during lookup. */
1647 return val;
1649 case tcc_declaration:
1650 case tcc_constant:
1651 return iterative_hash_expr (arg, val);
1653 default:
1654 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1656 unsigned n = cp_tree_operand_length (arg);
1657 for (i = 0; i < n; ++i)
1658 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1659 return val;
1662 gcc_unreachable ();
1663 return 0;
1666 /* Unregister the specialization SPEC as a specialization of TMPL.
1667 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1668 if the SPEC was listed as a specialization of TMPL.
1670 Note that SPEC has been ggc_freed, so we can't look inside it. */
1672 bool
1673 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1675 spec_entry *entry;
1676 spec_entry elt;
1678 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1679 elt.args = TI_ARGS (tinfo);
1680 elt.spec = NULL_TREE;
1682 entry = (spec_entry *) htab_find (decl_specializations, &elt);
1683 if (entry != NULL)
1685 gcc_assert (entry->spec == spec || entry->spec == new_spec);
1686 gcc_assert (new_spec != NULL_TREE);
1687 entry->spec = new_spec;
1688 return 1;
1691 return 0;
1694 /* Like register_specialization, but for local declarations. We are
1695 registering SPEC, an instantiation of TMPL. */
1697 static void
1698 register_local_specialization (tree spec, tree tmpl)
1700 void **slot;
1702 slot = pointer_map_insert (local_specializations, tmpl);
1703 *slot = spec;
1706 /* TYPE is a class type. Returns true if TYPE is an explicitly
1707 specialized class. */
1709 bool
1710 explicit_class_specialization_p (tree type)
1712 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1713 return false;
1714 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1717 /* Print the list of functions at FNS, going through all the overloads
1718 for each element of the list. Alternatively, FNS can not be a
1719 TREE_LIST, in which case it will be printed together with all the
1720 overloads.
1722 MORE and *STR should respectively be FALSE and NULL when the function
1723 is called from the outside. They are used internally on recursive
1724 calls. print_candidates manages the two parameters and leaves NULL
1725 in *STR when it ends. */
1727 static void
1728 print_candidates_1 (tree fns, bool more, const char **str)
1730 tree fn, fn2;
1731 char *spaces = NULL;
1733 for (fn = fns; fn; fn = OVL_NEXT (fn))
1734 if (TREE_CODE (fn) == TREE_LIST)
1736 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1737 print_candidates_1 (TREE_VALUE (fn2),
1738 TREE_CHAIN (fn2) || more, str);
1740 else
1742 tree cand = OVL_CURRENT (fn);
1743 if (!*str)
1745 /* Pick the prefix string. */
1746 if (!more && !OVL_NEXT (fns))
1748 inform (DECL_SOURCE_LOCATION (cand),
1749 "candidate is: %#D", cand);
1750 continue;
1753 *str = _("candidates are:");
1754 spaces = get_spaces (*str);
1756 inform (DECL_SOURCE_LOCATION (cand), "%s %#D", *str, cand);
1757 *str = spaces ? spaces : *str;
1760 if (!more)
1762 free (spaces);
1763 *str = NULL;
1767 /* Print the list of candidate FNS in an error message. FNS can also
1768 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1770 void
1771 print_candidates (tree fns)
1773 const char *str = NULL;
1774 print_candidates_1 (fns, false, &str);
1775 gcc_assert (str == NULL);
1778 /* Returns the template (one of the functions given by TEMPLATE_ID)
1779 which can be specialized to match the indicated DECL with the
1780 explicit template args given in TEMPLATE_ID. The DECL may be
1781 NULL_TREE if none is available. In that case, the functions in
1782 TEMPLATE_ID are non-members.
1784 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1785 specialization of a member template.
1787 The TEMPLATE_COUNT is the number of references to qualifying
1788 template classes that appeared in the name of the function. See
1789 check_explicit_specialization for a more accurate description.
1791 TSK indicates what kind of template declaration (if any) is being
1792 declared. TSK_TEMPLATE indicates that the declaration given by
1793 DECL, though a FUNCTION_DECL, has template parameters, and is
1794 therefore a template function.
1796 The template args (those explicitly specified and those deduced)
1797 are output in a newly created vector *TARGS_OUT.
1799 If it is impossible to determine the result, an error message is
1800 issued. The error_mark_node is returned to indicate failure. */
1802 static tree
1803 determine_specialization (tree template_id,
1804 tree decl,
1805 tree* targs_out,
1806 int need_member_template,
1807 int template_count,
1808 tmpl_spec_kind tsk)
1810 tree fns;
1811 tree targs;
1812 tree explicit_targs;
1813 tree candidates = NULL_TREE;
1814 /* A TREE_LIST of templates of which DECL may be a specialization.
1815 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1816 corresponding TREE_PURPOSE is the set of template arguments that,
1817 when used to instantiate the template, would produce a function
1818 with the signature of DECL. */
1819 tree templates = NULL_TREE;
1820 int header_count;
1821 cp_binding_level *b;
1823 *targs_out = NULL_TREE;
1825 if (template_id == error_mark_node || decl == error_mark_node)
1826 return error_mark_node;
1828 /* We shouldn't be specializing a member template of an
1829 unspecialized class template; we already gave an error in
1830 check_specialization_scope, now avoid crashing. */
1831 if (template_count && DECL_CLASS_SCOPE_P (decl)
1832 && template_class_depth (DECL_CONTEXT (decl)) > 0)
1834 gcc_assert (errorcount);
1835 return error_mark_node;
1838 fns = TREE_OPERAND (template_id, 0);
1839 explicit_targs = TREE_OPERAND (template_id, 1);
1841 if (fns == error_mark_node)
1842 return error_mark_node;
1844 /* Check for baselinks. */
1845 if (BASELINK_P (fns))
1846 fns = BASELINK_FUNCTIONS (fns);
1848 if (!is_overloaded_fn (fns))
1850 error ("%qD is not a function template", fns);
1851 return error_mark_node;
1854 /* Count the number of template headers specified for this
1855 specialization. */
1856 header_count = 0;
1857 for (b = current_binding_level;
1858 b->kind == sk_template_parms;
1859 b = b->level_chain)
1860 ++header_count;
1862 for (; fns; fns = OVL_NEXT (fns))
1864 tree fn = OVL_CURRENT (fns);
1866 if (TREE_CODE (fn) == TEMPLATE_DECL)
1868 tree decl_arg_types;
1869 tree fn_arg_types;
1870 tree insttype;
1872 /* In case of explicit specialization, we need to check if
1873 the number of template headers appearing in the specialization
1874 is correct. This is usually done in check_explicit_specialization,
1875 but the check done there cannot be exhaustive when specializing
1876 member functions. Consider the following code:
1878 template <> void A<int>::f(int);
1879 template <> template <> void A<int>::f(int);
1881 Assuming that A<int> is not itself an explicit specialization
1882 already, the first line specializes "f" which is a non-template
1883 member function, whilst the second line specializes "f" which
1884 is a template member function. So both lines are syntactically
1885 correct, and check_explicit_specialization does not reject
1886 them.
1888 Here, we can do better, as we are matching the specialization
1889 against the declarations. We count the number of template
1890 headers, and we check if they match TEMPLATE_COUNT + 1
1891 (TEMPLATE_COUNT is the number of qualifying template classes,
1892 plus there must be another header for the member template
1893 itself).
1895 Notice that if header_count is zero, this is not a
1896 specialization but rather a template instantiation, so there
1897 is no check we can perform here. */
1898 if (header_count && header_count != template_count + 1)
1899 continue;
1901 /* Check that the number of template arguments at the
1902 innermost level for DECL is the same as for FN. */
1903 if (current_binding_level->kind == sk_template_parms
1904 && !current_binding_level->explicit_spec_p
1905 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1906 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1907 (current_template_parms))))
1908 continue;
1910 /* DECL might be a specialization of FN. */
1911 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1912 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1914 /* For a non-static member function, we need to make sure
1915 that the const qualification is the same. Since
1916 get_bindings does not try to merge the "this" parameter,
1917 we must do the comparison explicitly. */
1918 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1919 && !same_type_p (TREE_VALUE (fn_arg_types),
1920 TREE_VALUE (decl_arg_types)))
1921 continue;
1923 /* Skip the "this" parameter and, for constructors of
1924 classes with virtual bases, the VTT parameter. A
1925 full specialization of a constructor will have a VTT
1926 parameter, but a template never will. */
1927 decl_arg_types
1928 = skip_artificial_parms_for (decl, decl_arg_types);
1929 fn_arg_types
1930 = skip_artificial_parms_for (fn, fn_arg_types);
1932 /* Function templates cannot be specializations; there are
1933 no partial specializations of functions. Therefore, if
1934 the type of DECL does not match FN, there is no
1935 match. */
1936 if (tsk == tsk_template)
1938 if (compparms (fn_arg_types, decl_arg_types))
1939 candidates = tree_cons (NULL_TREE, fn, candidates);
1940 continue;
1943 /* See whether this function might be a specialization of this
1944 template. Suppress access control because we might be trying
1945 to make this specialization a friend, and we have already done
1946 access control for the declaration of the specialization. */
1947 push_deferring_access_checks (dk_no_check);
1948 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1949 pop_deferring_access_checks ();
1951 if (!targs)
1952 /* We cannot deduce template arguments that when used to
1953 specialize TMPL will produce DECL. */
1954 continue;
1956 /* Make sure that the deduced arguments actually work. */
1957 insttype = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
1958 if (insttype == error_mark_node)
1959 continue;
1960 fn_arg_types
1961 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (insttype));
1962 if (!compparms (fn_arg_types, decl_arg_types))
1963 continue;
1965 /* Save this template, and the arguments deduced. */
1966 templates = tree_cons (targs, fn, templates);
1968 else if (need_member_template)
1969 /* FN is an ordinary member function, and we need a
1970 specialization of a member template. */
1972 else if (TREE_CODE (fn) != FUNCTION_DECL)
1973 /* We can get IDENTIFIER_NODEs here in certain erroneous
1974 cases. */
1976 else if (!DECL_FUNCTION_MEMBER_P (fn))
1977 /* This is just an ordinary non-member function. Nothing can
1978 be a specialization of that. */
1980 else if (DECL_ARTIFICIAL (fn))
1981 /* Cannot specialize functions that are created implicitly. */
1983 else
1985 tree decl_arg_types;
1987 /* This is an ordinary member function. However, since
1988 we're here, we can assume it's enclosing class is a
1989 template class. For example,
1991 template <typename T> struct S { void f(); };
1992 template <> void S<int>::f() {}
1994 Here, S<int>::f is a non-template, but S<int> is a
1995 template class. If FN has the same type as DECL, we
1996 might be in business. */
1998 if (!DECL_TEMPLATE_INFO (fn))
1999 /* Its enclosing class is an explicit specialization
2000 of a template class. This is not a candidate. */
2001 continue;
2003 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
2004 TREE_TYPE (TREE_TYPE (fn))))
2005 /* The return types differ. */
2006 continue;
2008 /* Adjust the type of DECL in case FN is a static member. */
2009 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
2010 if (DECL_STATIC_FUNCTION_P (fn)
2011 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2012 decl_arg_types = TREE_CHAIN (decl_arg_types);
2014 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
2015 decl_arg_types))
2016 /* They match! */
2017 candidates = tree_cons (NULL_TREE, fn, candidates);
2021 if (templates && TREE_CHAIN (templates))
2023 /* We have:
2025 [temp.expl.spec]
2027 It is possible for a specialization with a given function
2028 signature to be instantiated from more than one function
2029 template. In such cases, explicit specification of the
2030 template arguments must be used to uniquely identify the
2031 function template specialization being specialized.
2033 Note that here, there's no suggestion that we're supposed to
2034 determine which of the candidate templates is most
2035 specialized. However, we, also have:
2037 [temp.func.order]
2039 Partial ordering of overloaded function template
2040 declarations is used in the following contexts to select
2041 the function template to which a function template
2042 specialization refers:
2044 -- when an explicit specialization refers to a function
2045 template.
2047 So, we do use the partial ordering rules, at least for now.
2048 This extension can only serve to make invalid programs valid,
2049 so it's safe. And, there is strong anecdotal evidence that
2050 the committee intended the partial ordering rules to apply;
2051 the EDG front end has that behavior, and John Spicer claims
2052 that the committee simply forgot to delete the wording in
2053 [temp.expl.spec]. */
2054 tree tmpl = most_specialized_instantiation (templates);
2055 if (tmpl != error_mark_node)
2057 templates = tmpl;
2058 TREE_CHAIN (templates) = NULL_TREE;
2062 if (templates == NULL_TREE && candidates == NULL_TREE)
2064 error ("template-id %qD for %q+D does not match any template "
2065 "declaration", template_id, decl);
2066 if (header_count && header_count != template_count + 1)
2067 inform (input_location, "saw %d %<template<>%>, need %d for "
2068 "specializing a member function template",
2069 header_count, template_count + 1);
2070 return error_mark_node;
2072 else if ((templates && TREE_CHAIN (templates))
2073 || (candidates && TREE_CHAIN (candidates))
2074 || (templates && candidates))
2076 error ("ambiguous template specialization %qD for %q+D",
2077 template_id, decl);
2078 candidates = chainon (candidates, templates);
2079 print_candidates (candidates);
2080 return error_mark_node;
2083 /* We have one, and exactly one, match. */
2084 if (candidates)
2086 tree fn = TREE_VALUE (candidates);
2087 *targs_out = copy_node (DECL_TI_ARGS (fn));
2088 /* DECL is a re-declaration or partial instantiation of a template
2089 function. */
2090 if (TREE_CODE (fn) == TEMPLATE_DECL)
2091 return fn;
2092 /* It was a specialization of an ordinary member function in a
2093 template class. */
2094 return DECL_TI_TEMPLATE (fn);
2097 /* It was a specialization of a template. */
2098 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2099 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2101 *targs_out = copy_node (targs);
2102 SET_TMPL_ARGS_LEVEL (*targs_out,
2103 TMPL_ARGS_DEPTH (*targs_out),
2104 TREE_PURPOSE (templates));
2106 else
2107 *targs_out = TREE_PURPOSE (templates);
2108 return TREE_VALUE (templates);
2111 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2112 but with the default argument values filled in from those in the
2113 TMPL_TYPES. */
2115 static tree
2116 copy_default_args_to_explicit_spec_1 (tree spec_types,
2117 tree tmpl_types)
2119 tree new_spec_types;
2121 if (!spec_types)
2122 return NULL_TREE;
2124 if (spec_types == void_list_node)
2125 return void_list_node;
2127 /* Substitute into the rest of the list. */
2128 new_spec_types =
2129 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2130 TREE_CHAIN (tmpl_types));
2132 /* Add the default argument for this parameter. */
2133 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2134 TREE_VALUE (spec_types),
2135 new_spec_types);
2138 /* DECL is an explicit specialization. Replicate default arguments
2139 from the template it specializes. (That way, code like:
2141 template <class T> void f(T = 3);
2142 template <> void f(double);
2143 void g () { f (); }
2145 works, as required.) An alternative approach would be to look up
2146 the correct default arguments at the call-site, but this approach
2147 is consistent with how implicit instantiations are handled. */
2149 static void
2150 copy_default_args_to_explicit_spec (tree decl)
2152 tree tmpl;
2153 tree spec_types;
2154 tree tmpl_types;
2155 tree new_spec_types;
2156 tree old_type;
2157 tree new_type;
2158 tree t;
2159 tree object_type = NULL_TREE;
2160 tree in_charge = NULL_TREE;
2161 tree vtt = NULL_TREE;
2163 /* See if there's anything we need to do. */
2164 tmpl = DECL_TI_TEMPLATE (decl);
2165 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2166 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2167 if (TREE_PURPOSE (t))
2168 break;
2169 if (!t)
2170 return;
2172 old_type = TREE_TYPE (decl);
2173 spec_types = TYPE_ARG_TYPES (old_type);
2175 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2177 /* Remove the this pointer, but remember the object's type for
2178 CV quals. */
2179 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2180 spec_types = TREE_CHAIN (spec_types);
2181 tmpl_types = TREE_CHAIN (tmpl_types);
2183 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2185 /* DECL may contain more parameters than TMPL due to the extra
2186 in-charge parameter in constructors and destructors. */
2187 in_charge = spec_types;
2188 spec_types = TREE_CHAIN (spec_types);
2190 if (DECL_HAS_VTT_PARM_P (decl))
2192 vtt = spec_types;
2193 spec_types = TREE_CHAIN (spec_types);
2197 /* Compute the merged default arguments. */
2198 new_spec_types =
2199 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2201 /* Compute the new FUNCTION_TYPE. */
2202 if (object_type)
2204 if (vtt)
2205 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2206 TREE_VALUE (vtt),
2207 new_spec_types);
2209 if (in_charge)
2210 /* Put the in-charge parameter back. */
2211 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2212 TREE_VALUE (in_charge),
2213 new_spec_types);
2215 new_type = build_method_type_directly (object_type,
2216 TREE_TYPE (old_type),
2217 new_spec_types);
2219 else
2220 new_type = build_function_type (TREE_TYPE (old_type),
2221 new_spec_types);
2222 new_type = cp_build_type_attribute_variant (new_type,
2223 TYPE_ATTRIBUTES (old_type));
2224 new_type = build_exception_variant (new_type,
2225 TYPE_RAISES_EXCEPTIONS (old_type));
2226 TREE_TYPE (decl) = new_type;
2229 /* Return the number of template headers we expect to see for a definition
2230 or specialization of CTYPE or one of its non-template members. */
2233 num_template_headers_for_class (tree ctype)
2235 int num_templates = 0;
2237 while (ctype && CLASS_TYPE_P (ctype))
2239 /* You're supposed to have one `template <...>' for every
2240 template class, but you don't need one for a full
2241 specialization. For example:
2243 template <class T> struct S{};
2244 template <> struct S<int> { void f(); };
2245 void S<int>::f () {}
2247 is correct; there shouldn't be a `template <>' for the
2248 definition of `S<int>::f'. */
2249 if (!CLASSTYPE_TEMPLATE_INFO (ctype))
2250 /* If CTYPE does not have template information of any
2251 kind, then it is not a template, nor is it nested
2252 within a template. */
2253 break;
2254 if (explicit_class_specialization_p (ctype))
2255 break;
2256 if (PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (ctype)))
2257 ++num_templates;
2259 ctype = TYPE_CONTEXT (ctype);
2262 return num_templates;
2265 /* Do a simple sanity check on the template headers that precede the
2266 variable declaration DECL. */
2268 void
2269 check_template_variable (tree decl)
2271 tree ctx = CP_DECL_CONTEXT (decl);
2272 int wanted = num_template_headers_for_class (ctx);
2273 if (!TYPE_P (ctx) || !CLASSTYPE_TEMPLATE_INFO (ctx))
2274 permerror (DECL_SOURCE_LOCATION (decl),
2275 "%qD is not a static data member of a class template", decl);
2276 else if (template_header_count > wanted)
2278 pedwarn (DECL_SOURCE_LOCATION (decl), 0,
2279 "too many template headers for %D (should be %d)",
2280 decl, wanted);
2281 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (ctx))
2282 inform (DECL_SOURCE_LOCATION (decl),
2283 "members of an explicitly specialized class are defined "
2284 "without a template header");
2288 /* Check to see if the function just declared, as indicated in
2289 DECLARATOR, and in DECL, is a specialization of a function
2290 template. We may also discover that the declaration is an explicit
2291 instantiation at this point.
2293 Returns DECL, or an equivalent declaration that should be used
2294 instead if all goes well. Issues an error message if something is
2295 amiss. Returns error_mark_node if the error is not easily
2296 recoverable.
2298 FLAGS is a bitmask consisting of the following flags:
2300 2: The function has a definition.
2301 4: The function is a friend.
2303 The TEMPLATE_COUNT is the number of references to qualifying
2304 template classes that appeared in the name of the function. For
2305 example, in
2307 template <class T> struct S { void f(); };
2308 void S<int>::f();
2310 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2311 classes are not counted in the TEMPLATE_COUNT, so that in
2313 template <class T> struct S {};
2314 template <> struct S<int> { void f(); }
2315 template <> void S<int>::f();
2317 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2318 invalid; there should be no template <>.)
2320 If the function is a specialization, it is marked as such via
2321 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2322 is set up correctly, and it is added to the list of specializations
2323 for that template. */
2325 tree
2326 check_explicit_specialization (tree declarator,
2327 tree decl,
2328 int template_count,
2329 int flags)
2331 int have_def = flags & 2;
2332 int is_friend = flags & 4;
2333 int specialization = 0;
2334 int explicit_instantiation = 0;
2335 int member_specialization = 0;
2336 tree ctype = DECL_CLASS_CONTEXT (decl);
2337 tree dname = DECL_NAME (decl);
2338 tmpl_spec_kind tsk;
2340 if (is_friend)
2342 if (!processing_specialization)
2343 tsk = tsk_none;
2344 else
2345 tsk = tsk_excessive_parms;
2347 else
2348 tsk = current_tmpl_spec_kind (template_count);
2350 switch (tsk)
2352 case tsk_none:
2353 if (processing_specialization)
2355 specialization = 1;
2356 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2358 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2360 if (is_friend)
2361 /* This could be something like:
2363 template <class T> void f(T);
2364 class S { friend void f<>(int); } */
2365 specialization = 1;
2366 else
2368 /* This case handles bogus declarations like template <>
2369 template <class T> void f<int>(); */
2371 error ("template-id %qD in declaration of primary template",
2372 declarator);
2373 return decl;
2376 break;
2378 case tsk_invalid_member_spec:
2379 /* The error has already been reported in
2380 check_specialization_scope. */
2381 return error_mark_node;
2383 case tsk_invalid_expl_inst:
2384 error ("template parameter list used in explicit instantiation");
2386 /* Fall through. */
2388 case tsk_expl_inst:
2389 if (have_def)
2390 error ("definition provided for explicit instantiation");
2392 explicit_instantiation = 1;
2393 break;
2395 case tsk_excessive_parms:
2396 case tsk_insufficient_parms:
2397 if (tsk == tsk_excessive_parms)
2398 error ("too many template parameter lists in declaration of %qD",
2399 decl);
2400 else if (template_header_count)
2401 error("too few template parameter lists in declaration of %qD", decl);
2402 else
2403 error("explicit specialization of %qD must be introduced by "
2404 "%<template <>%>", decl);
2406 /* Fall through. */
2407 case tsk_expl_spec:
2408 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2409 if (ctype)
2410 member_specialization = 1;
2411 else
2412 specialization = 1;
2413 break;
2415 case tsk_template:
2416 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2418 /* This case handles bogus declarations like template <>
2419 template <class T> void f<int>(); */
2421 if (uses_template_parms (declarator))
2422 error ("function template partial specialization %qD "
2423 "is not allowed", declarator);
2424 else
2425 error ("template-id %qD in declaration of primary template",
2426 declarator);
2427 return decl;
2430 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2431 /* This is a specialization of a member template, without
2432 specialization the containing class. Something like:
2434 template <class T> struct S {
2435 template <class U> void f (U);
2437 template <> template <class U> void S<int>::f(U) {}
2439 That's a specialization -- but of the entire template. */
2440 specialization = 1;
2441 break;
2443 default:
2444 gcc_unreachable ();
2447 if (specialization || member_specialization)
2449 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2450 for (; t; t = TREE_CHAIN (t))
2451 if (TREE_PURPOSE (t))
2453 permerror (input_location,
2454 "default argument specified in explicit specialization");
2455 break;
2459 if (specialization || member_specialization || explicit_instantiation)
2461 tree tmpl = NULL_TREE;
2462 tree targs = NULL_TREE;
2464 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2465 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2467 tree fns;
2469 gcc_assert (identifier_p (declarator));
2470 if (ctype)
2471 fns = dname;
2472 else
2474 /* If there is no class context, the explicit instantiation
2475 must be at namespace scope. */
2476 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2478 /* Find the namespace binding, using the declaration
2479 context. */
2480 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2481 false, true);
2482 if (fns == error_mark_node || !is_overloaded_fn (fns))
2484 error ("%qD is not a template function", dname);
2485 fns = error_mark_node;
2487 else
2489 tree fn = OVL_CURRENT (fns);
2490 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2491 CP_DECL_CONTEXT (fn)))
2492 error ("%qD is not declared in %qD",
2493 decl, current_namespace);
2497 declarator = lookup_template_function (fns, NULL_TREE);
2500 if (declarator == error_mark_node)
2501 return error_mark_node;
2503 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2505 if (!explicit_instantiation)
2506 /* A specialization in class scope. This is invalid,
2507 but the error will already have been flagged by
2508 check_specialization_scope. */
2509 return error_mark_node;
2510 else
2512 /* It's not valid to write an explicit instantiation in
2513 class scope, e.g.:
2515 class C { template void f(); }
2517 This case is caught by the parser. However, on
2518 something like:
2520 template class C { void f(); };
2522 (which is invalid) we can get here. The error will be
2523 issued later. */
2527 return decl;
2529 else if (ctype != NULL_TREE
2530 && (identifier_p (TREE_OPERAND (declarator, 0))))
2532 /* Find the list of functions in ctype that have the same
2533 name as the declared function. */
2534 tree name = TREE_OPERAND (declarator, 0);
2535 tree fns = NULL_TREE;
2536 int idx;
2538 if (constructor_name_p (name, ctype))
2540 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2542 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2543 : !CLASSTYPE_DESTRUCTORS (ctype))
2545 /* From [temp.expl.spec]:
2547 If such an explicit specialization for the member
2548 of a class template names an implicitly-declared
2549 special member function (clause _special_), the
2550 program is ill-formed.
2552 Similar language is found in [temp.explicit]. */
2553 error ("specialization of implicitly-declared special member function");
2554 return error_mark_node;
2557 name = is_constructor ? ctor_identifier : dtor_identifier;
2560 if (!DECL_CONV_FN_P (decl))
2562 idx = lookup_fnfields_1 (ctype, name);
2563 if (idx >= 0)
2564 fns = (*CLASSTYPE_METHOD_VEC (ctype))[idx];
2566 else
2568 vec<tree, va_gc> *methods;
2569 tree ovl;
2571 /* For a type-conversion operator, we cannot do a
2572 name-based lookup. We might be looking for `operator
2573 int' which will be a specialization of `operator T'.
2574 So, we find *all* the conversion operators, and then
2575 select from them. */
2576 fns = NULL_TREE;
2578 methods = CLASSTYPE_METHOD_VEC (ctype);
2579 if (methods)
2580 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2581 methods->iterate (idx, &ovl);
2582 ++idx)
2584 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2585 /* There are no more conversion functions. */
2586 break;
2588 /* Glue all these conversion functions together
2589 with those we already have. */
2590 for (; ovl; ovl = OVL_NEXT (ovl))
2591 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2595 if (fns == NULL_TREE)
2597 error ("no member function %qD declared in %qT", name, ctype);
2598 return error_mark_node;
2600 else
2601 TREE_OPERAND (declarator, 0) = fns;
2604 /* Figure out what exactly is being specialized at this point.
2605 Note that for an explicit instantiation, even one for a
2606 member function, we cannot tell apriori whether the
2607 instantiation is for a member template, or just a member
2608 function of a template class. Even if a member template is
2609 being instantiated, the member template arguments may be
2610 elided if they can be deduced from the rest of the
2611 declaration. */
2612 tmpl = determine_specialization (declarator, decl,
2613 &targs,
2614 member_specialization,
2615 template_count,
2616 tsk);
2618 if (!tmpl || tmpl == error_mark_node)
2619 /* We couldn't figure out what this declaration was
2620 specializing. */
2621 return error_mark_node;
2622 else
2624 tree gen_tmpl = most_general_template (tmpl);
2626 if (explicit_instantiation)
2628 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2629 is done by do_decl_instantiation later. */
2631 int arg_depth = TMPL_ARGS_DEPTH (targs);
2632 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2634 if (arg_depth > parm_depth)
2636 /* If TMPL is not the most general template (for
2637 example, if TMPL is a friend template that is
2638 injected into namespace scope), then there will
2639 be too many levels of TARGS. Remove some of them
2640 here. */
2641 int i;
2642 tree new_targs;
2644 new_targs = make_tree_vec (parm_depth);
2645 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2646 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2647 = TREE_VEC_ELT (targs, i);
2648 targs = new_targs;
2651 return instantiate_template (tmpl, targs, tf_error);
2654 /* If we thought that the DECL was a member function, but it
2655 turns out to be specializing a static member function,
2656 make DECL a static member function as well. */
2657 if (DECL_STATIC_FUNCTION_P (tmpl)
2658 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2659 revert_static_member_fn (decl);
2661 /* If this is a specialization of a member template of a
2662 template class, we want to return the TEMPLATE_DECL, not
2663 the specialization of it. */
2664 if (tsk == tsk_template)
2666 tree result = DECL_TEMPLATE_RESULT (tmpl);
2667 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2668 DECL_INITIAL (result) = NULL_TREE;
2669 if (have_def)
2671 tree parm;
2672 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2673 DECL_SOURCE_LOCATION (result)
2674 = DECL_SOURCE_LOCATION (decl);
2675 /* We want to use the argument list specified in the
2676 definition, not in the original declaration. */
2677 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2678 for (parm = DECL_ARGUMENTS (result); parm;
2679 parm = DECL_CHAIN (parm))
2680 DECL_CONTEXT (parm) = result;
2682 return register_specialization (tmpl, gen_tmpl, targs,
2683 is_friend, 0);
2686 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2687 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2689 /* Inherit default function arguments from the template
2690 DECL is specializing. */
2691 copy_default_args_to_explicit_spec (decl);
2693 /* This specialization has the same protection as the
2694 template it specializes. */
2695 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2696 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2698 /* 7.1.1-1 [dcl.stc]
2700 A storage-class-specifier shall not be specified in an
2701 explicit specialization...
2703 The parser rejects these, so unless action is taken here,
2704 explicit function specializations will always appear with
2705 global linkage.
2707 The action recommended by the C++ CWG in response to C++
2708 defect report 605 is to make the storage class and linkage
2709 of the explicit specialization match the templated function:
2711 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2713 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2715 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2716 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2718 /* This specialization has the same linkage and visibility as
2719 the function template it specializes. */
2720 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2721 if (! TREE_PUBLIC (decl))
2723 DECL_INTERFACE_KNOWN (decl) = 1;
2724 DECL_NOT_REALLY_EXTERN (decl) = 1;
2726 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2727 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2729 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2730 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2734 /* If DECL is a friend declaration, declared using an
2735 unqualified name, the namespace associated with DECL may
2736 have been set incorrectly. For example, in:
2738 template <typename T> void f(T);
2739 namespace N {
2740 struct S { friend void f<int>(int); }
2743 we will have set the DECL_CONTEXT for the friend
2744 declaration to N, rather than to the global namespace. */
2745 if (DECL_NAMESPACE_SCOPE_P (decl))
2746 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2748 if (is_friend && !have_def)
2749 /* This is not really a declaration of a specialization.
2750 It's just the name of an instantiation. But, it's not
2751 a request for an instantiation, either. */
2752 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2753 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2754 /* This is indeed a specialization. In case of constructors
2755 and destructors, we need in-charge and not-in-charge
2756 versions in V3 ABI. */
2757 clone_function_decl (decl, /*update_method_vec_p=*/0);
2759 /* Register this specialization so that we can find it
2760 again. */
2761 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2765 return decl;
2768 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2769 parameters. These are represented in the same format used for
2770 DECL_TEMPLATE_PARMS. */
2773 comp_template_parms (const_tree parms1, const_tree parms2)
2775 const_tree p1;
2776 const_tree p2;
2778 if (parms1 == parms2)
2779 return 1;
2781 for (p1 = parms1, p2 = parms2;
2782 p1 != NULL_TREE && p2 != NULL_TREE;
2783 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2785 tree t1 = TREE_VALUE (p1);
2786 tree t2 = TREE_VALUE (p2);
2787 int i;
2789 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2790 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2792 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2793 return 0;
2795 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2797 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2798 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2800 /* If either of the template parameters are invalid, assume
2801 they match for the sake of error recovery. */
2802 if (parm1 == error_mark_node || parm2 == error_mark_node)
2803 return 1;
2805 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2806 return 0;
2808 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2809 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2810 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2811 continue;
2812 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2813 return 0;
2817 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2818 /* One set of parameters has more parameters lists than the
2819 other. */
2820 return 0;
2822 return 1;
2825 /* Determine whether PARM is a parameter pack. */
2827 bool
2828 template_parameter_pack_p (const_tree parm)
2830 /* Determine if we have a non-type template parameter pack. */
2831 if (TREE_CODE (parm) == PARM_DECL)
2832 return (DECL_TEMPLATE_PARM_P (parm)
2833 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2834 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
2835 return TEMPLATE_PARM_PARAMETER_PACK (parm);
2837 /* If this is a list of template parameters, we could get a
2838 TYPE_DECL or a TEMPLATE_DECL. */
2839 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2840 parm = TREE_TYPE (parm);
2842 /* Otherwise it must be a type template parameter. */
2843 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2844 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2845 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2848 /* Determine if T is a function parameter pack. */
2850 bool
2851 function_parameter_pack_p (const_tree t)
2853 if (t && TREE_CODE (t) == PARM_DECL)
2854 return FUNCTION_PARAMETER_PACK_P (t);
2855 return false;
2858 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2859 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2861 tree
2862 get_function_template_decl (const_tree primary_func_tmpl_inst)
2864 if (! primary_func_tmpl_inst
2865 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2866 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2867 return NULL;
2869 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2872 /* Return true iff the function parameter PARAM_DECL was expanded
2873 from the function parameter pack PACK. */
2875 bool
2876 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2878 if (DECL_ARTIFICIAL (param_decl)
2879 || !function_parameter_pack_p (pack))
2880 return false;
2882 /* The parameter pack and its pack arguments have the same
2883 DECL_PARM_INDEX. */
2884 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2887 /* Determine whether ARGS describes a variadic template args list,
2888 i.e., one that is terminated by a template argument pack. */
2890 static bool
2891 template_args_variadic_p (tree args)
2893 int nargs;
2894 tree last_parm;
2896 if (args == NULL_TREE)
2897 return false;
2899 args = INNERMOST_TEMPLATE_ARGS (args);
2900 nargs = TREE_VEC_LENGTH (args);
2902 if (nargs == 0)
2903 return false;
2905 last_parm = TREE_VEC_ELT (args, nargs - 1);
2907 return ARGUMENT_PACK_P (last_parm);
2910 /* Generate a new name for the parameter pack name NAME (an
2911 IDENTIFIER_NODE) that incorporates its */
2913 static tree
2914 make_ith_pack_parameter_name (tree name, int i)
2916 /* Munge the name to include the parameter index. */
2917 #define NUMBUF_LEN 128
2918 char numbuf[NUMBUF_LEN];
2919 char* newname;
2920 int newname_len;
2922 if (name == NULL_TREE)
2923 return name;
2924 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2925 newname_len = IDENTIFIER_LENGTH (name)
2926 + strlen (numbuf) + 2;
2927 newname = (char*)alloca (newname_len);
2928 snprintf (newname, newname_len,
2929 "%s#%i", IDENTIFIER_POINTER (name), i);
2930 return get_identifier (newname);
2933 /* Return true if T is a primary function, class or alias template
2934 instantiation. */
2936 bool
2937 primary_template_instantiation_p (const_tree t)
2939 if (!t)
2940 return false;
2942 if (TREE_CODE (t) == FUNCTION_DECL)
2943 return DECL_LANG_SPECIFIC (t)
2944 && DECL_TEMPLATE_INSTANTIATION (t)
2945 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2946 else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2947 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2948 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2949 else if (alias_template_specialization_p (t))
2950 return true;
2951 return false;
2954 /* Return true if PARM is a template template parameter. */
2956 bool
2957 template_template_parameter_p (const_tree parm)
2959 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2962 /* Return true iff PARM is a DECL representing a type template
2963 parameter. */
2965 bool
2966 template_type_parameter_p (const_tree parm)
2968 return (parm
2969 && (TREE_CODE (parm) == TYPE_DECL
2970 || TREE_CODE (parm) == TEMPLATE_DECL)
2971 && DECL_TEMPLATE_PARM_P (parm));
2974 /* Return the template parameters of T if T is a
2975 primary template instantiation, NULL otherwise. */
2977 tree
2978 get_primary_template_innermost_parameters (const_tree t)
2980 tree parms = NULL, template_info = NULL;
2982 if ((template_info = get_template_info (t))
2983 && primary_template_instantiation_p (t))
2984 parms = INNERMOST_TEMPLATE_PARMS
2985 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2987 return parms;
2990 /* Return the template parameters of the LEVELth level from the full list
2991 of template parameters PARMS. */
2993 tree
2994 get_template_parms_at_level (tree parms, int level)
2996 tree p;
2997 if (!parms
2998 || TREE_CODE (parms) != TREE_LIST
2999 || level > TMPL_PARMS_DEPTH (parms))
3000 return NULL_TREE;
3002 for (p = parms; p; p = TREE_CHAIN (p))
3003 if (TMPL_PARMS_DEPTH (p) == level)
3004 return p;
3006 return NULL_TREE;
3009 /* Returns the template arguments of T if T is a template instantiation,
3010 NULL otherwise. */
3012 tree
3013 get_template_innermost_arguments (const_tree t)
3015 tree args = NULL, template_info = NULL;
3017 if ((template_info = get_template_info (t))
3018 && TI_ARGS (template_info))
3019 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
3021 return args;
3024 /* Return the argument pack elements of T if T is a template argument pack,
3025 NULL otherwise. */
3027 tree
3028 get_template_argument_pack_elems (const_tree t)
3030 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
3031 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
3032 return NULL;
3034 return ARGUMENT_PACK_ARGS (t);
3037 /* Structure used to track the progress of find_parameter_packs_r. */
3038 struct find_parameter_pack_data
3040 /* TREE_LIST that will contain all of the parameter packs found by
3041 the traversal. */
3042 tree* parameter_packs;
3044 /* Set of AST nodes that have been visited by the traversal. */
3045 struct pointer_set_t *visited;
3048 /* Identifies all of the argument packs that occur in a template
3049 argument and appends them to the TREE_LIST inside DATA, which is a
3050 find_parameter_pack_data structure. This is a subroutine of
3051 make_pack_expansion and uses_parameter_packs. */
3052 static tree
3053 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
3055 tree t = *tp;
3056 struct find_parameter_pack_data* ppd =
3057 (struct find_parameter_pack_data*)data;
3058 bool parameter_pack_p = false;
3060 /* Handle type aliases/typedefs. */
3061 if (TYPE_P (t)
3062 && TYPE_NAME (t)
3063 && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL
3064 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
3066 if (TYPE_TEMPLATE_INFO (t))
3067 cp_walk_tree (&TYPE_TI_ARGS (t),
3068 &find_parameter_packs_r,
3069 ppd, ppd->visited);
3070 *walk_subtrees = 0;
3071 return NULL_TREE;
3074 /* Identify whether this is a parameter pack or not. */
3075 switch (TREE_CODE (t))
3077 case TEMPLATE_PARM_INDEX:
3078 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3079 parameter_pack_p = true;
3080 break;
3082 case TEMPLATE_TYPE_PARM:
3083 t = TYPE_MAIN_VARIANT (t);
3084 case TEMPLATE_TEMPLATE_PARM:
3085 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3086 parameter_pack_p = true;
3087 break;
3089 case PARM_DECL:
3090 if (FUNCTION_PARAMETER_PACK_P (t))
3092 /* We don't want to walk into the type of a PARM_DECL,
3093 because we don't want to see the type parameter pack. */
3094 *walk_subtrees = 0;
3095 parameter_pack_p = true;
3097 break;
3099 case BASES:
3100 parameter_pack_p = true;
3101 break;
3102 default:
3103 /* Not a parameter pack. */
3104 break;
3107 if (parameter_pack_p)
3109 /* Add this parameter pack to the list. */
3110 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
3113 if (TYPE_P (t))
3114 cp_walk_tree (&TYPE_CONTEXT (t),
3115 &find_parameter_packs_r, ppd, ppd->visited);
3117 /* This switch statement will return immediately if we don't find a
3118 parameter pack. */
3119 switch (TREE_CODE (t))
3121 case TEMPLATE_PARM_INDEX:
3122 return NULL_TREE;
3124 case BOUND_TEMPLATE_TEMPLATE_PARM:
3125 /* Check the template itself. */
3126 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3127 &find_parameter_packs_r, ppd, ppd->visited);
3128 /* Check the template arguments. */
3129 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3130 ppd->visited);
3131 *walk_subtrees = 0;
3132 return NULL_TREE;
3134 case TEMPLATE_TYPE_PARM:
3135 case TEMPLATE_TEMPLATE_PARM:
3136 return NULL_TREE;
3138 case PARM_DECL:
3139 return NULL_TREE;
3141 case RECORD_TYPE:
3142 if (TYPE_PTRMEMFUNC_P (t))
3143 return NULL_TREE;
3144 /* Fall through. */
3146 case UNION_TYPE:
3147 case ENUMERAL_TYPE:
3148 if (TYPE_TEMPLATE_INFO (t))
3149 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3150 &find_parameter_packs_r, ppd, ppd->visited);
3152 *walk_subtrees = 0;
3153 return NULL_TREE;
3155 case CONSTRUCTOR:
3156 case TEMPLATE_DECL:
3157 cp_walk_tree (&TREE_TYPE (t),
3158 &find_parameter_packs_r, ppd, ppd->visited);
3159 return NULL_TREE;
3161 case TYPENAME_TYPE:
3162 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3163 ppd, ppd->visited);
3164 *walk_subtrees = 0;
3165 return NULL_TREE;
3167 case TYPE_PACK_EXPANSION:
3168 case EXPR_PACK_EXPANSION:
3169 *walk_subtrees = 0;
3170 return NULL_TREE;
3172 case INTEGER_TYPE:
3173 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3174 ppd, ppd->visited);
3175 *walk_subtrees = 0;
3176 return NULL_TREE;
3178 case IDENTIFIER_NODE:
3179 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3180 ppd->visited);
3181 *walk_subtrees = 0;
3182 return NULL_TREE;
3184 default:
3185 return NULL_TREE;
3188 return NULL_TREE;
3191 /* Determines if the expression or type T uses any parameter packs. */
3192 bool
3193 uses_parameter_packs (tree t)
3195 tree parameter_packs = NULL_TREE;
3196 struct find_parameter_pack_data ppd;
3197 ppd.parameter_packs = &parameter_packs;
3198 ppd.visited = pointer_set_create ();
3199 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3200 pointer_set_destroy (ppd.visited);
3201 return parameter_packs != NULL_TREE;
3204 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3205 representation a base-class initializer into a parameter pack
3206 expansion. If all goes well, the resulting node will be an
3207 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3208 respectively. */
3209 tree
3210 make_pack_expansion (tree arg)
3212 tree result;
3213 tree parameter_packs = NULL_TREE;
3214 bool for_types = false;
3215 struct find_parameter_pack_data ppd;
3217 if (!arg || arg == error_mark_node)
3218 return arg;
3220 if (TREE_CODE (arg) == TREE_LIST)
3222 /* The only time we will see a TREE_LIST here is for a base
3223 class initializer. In this case, the TREE_PURPOSE will be a
3224 _TYPE node (representing the base class expansion we're
3225 initializing) and the TREE_VALUE will be a TREE_LIST
3226 containing the initialization arguments.
3228 The resulting expansion looks somewhat different from most
3229 expansions. Rather than returning just one _EXPANSION, we
3230 return a TREE_LIST whose TREE_PURPOSE is a
3231 TYPE_PACK_EXPANSION containing the bases that will be
3232 initialized. The TREE_VALUE will be identical to the
3233 original TREE_VALUE, which is a list of arguments that will
3234 be passed to each base. We do not introduce any new pack
3235 expansion nodes into the TREE_VALUE (although it is possible
3236 that some already exist), because the TREE_PURPOSE and
3237 TREE_VALUE all need to be expanded together with the same
3238 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3239 resulting TREE_PURPOSE will mention the parameter packs in
3240 both the bases and the arguments to the bases. */
3241 tree purpose;
3242 tree value;
3243 tree parameter_packs = NULL_TREE;
3245 /* Determine which parameter packs will be used by the base
3246 class expansion. */
3247 ppd.visited = pointer_set_create ();
3248 ppd.parameter_packs = &parameter_packs;
3249 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3250 &ppd, ppd.visited);
3252 if (parameter_packs == NULL_TREE)
3254 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3255 pointer_set_destroy (ppd.visited);
3256 return error_mark_node;
3259 if (TREE_VALUE (arg) != void_type_node)
3261 /* Collect the sets of parameter packs used in each of the
3262 initialization arguments. */
3263 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3265 /* Determine which parameter packs will be expanded in this
3266 argument. */
3267 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3268 &ppd, ppd.visited);
3272 pointer_set_destroy (ppd.visited);
3274 /* Create the pack expansion type for the base type. */
3275 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3276 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3277 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3279 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3280 they will rarely be compared to anything. */
3281 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3283 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3286 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3287 for_types = true;
3289 /* Build the PACK_EXPANSION_* node. */
3290 result = for_types
3291 ? cxx_make_type (TYPE_PACK_EXPANSION)
3292 : make_node (EXPR_PACK_EXPANSION);
3293 SET_PACK_EXPANSION_PATTERN (result, arg);
3294 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3296 /* Propagate type and const-expression information. */
3297 TREE_TYPE (result) = TREE_TYPE (arg);
3298 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3300 else
3301 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3302 they will rarely be compared to anything. */
3303 SET_TYPE_STRUCTURAL_EQUALITY (result);
3305 /* Determine which parameter packs will be expanded. */
3306 ppd.parameter_packs = &parameter_packs;
3307 ppd.visited = pointer_set_create ();
3308 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3309 pointer_set_destroy (ppd.visited);
3311 /* Make sure we found some parameter packs. */
3312 if (parameter_packs == NULL_TREE)
3314 if (TYPE_P (arg))
3315 error ("expansion pattern %<%T%> contains no argument packs", arg);
3316 else
3317 error ("expansion pattern %<%E%> contains no argument packs", arg);
3318 return error_mark_node;
3320 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3322 PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p ();
3324 return result;
3327 /* Checks T for any "bare" parameter packs, which have not yet been
3328 expanded, and issues an error if any are found. This operation can
3329 only be done on full expressions or types (e.g., an expression
3330 statement, "if" condition, etc.), because we could have expressions like:
3332 foo(f(g(h(args)))...)
3334 where "args" is a parameter pack. check_for_bare_parameter_packs
3335 should not be called for the subexpressions args, h(args),
3336 g(h(args)), or f(g(h(args))), because we would produce erroneous
3337 error messages.
3339 Returns TRUE and emits an error if there were bare parameter packs,
3340 returns FALSE otherwise. */
3341 bool
3342 check_for_bare_parameter_packs (tree t)
3344 tree parameter_packs = NULL_TREE;
3345 struct find_parameter_pack_data ppd;
3347 if (!processing_template_decl || !t || t == error_mark_node)
3348 return false;
3350 if (TREE_CODE (t) == TYPE_DECL)
3351 t = TREE_TYPE (t);
3353 ppd.parameter_packs = &parameter_packs;
3354 ppd.visited = pointer_set_create ();
3355 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3356 pointer_set_destroy (ppd.visited);
3358 if (parameter_packs)
3360 error ("parameter packs not expanded with %<...%>:");
3361 while (parameter_packs)
3363 tree pack = TREE_VALUE (parameter_packs);
3364 tree name = NULL_TREE;
3366 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3367 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3368 name = TYPE_NAME (pack);
3369 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3370 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3371 else
3372 name = DECL_NAME (pack);
3374 if (name)
3375 inform (input_location, " %qD", name);
3376 else
3377 inform (input_location, " <anonymous>");
3379 parameter_packs = TREE_CHAIN (parameter_packs);
3382 return true;
3385 return false;
3388 /* Expand any parameter packs that occur in the template arguments in
3389 ARGS. */
3390 tree
3391 expand_template_argument_pack (tree args)
3393 tree result_args = NULL_TREE;
3394 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3395 int num_result_args = -1;
3396 int non_default_args_count = -1;
3398 /* First, determine if we need to expand anything, and the number of
3399 slots we'll need. */
3400 for (in_arg = 0; in_arg < nargs; ++in_arg)
3402 tree arg = TREE_VEC_ELT (args, in_arg);
3403 if (arg == NULL_TREE)
3404 return args;
3405 if (ARGUMENT_PACK_P (arg))
3407 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3408 if (num_result_args < 0)
3409 num_result_args = in_arg + num_packed;
3410 else
3411 num_result_args += num_packed;
3413 else
3415 if (num_result_args >= 0)
3416 num_result_args++;
3420 /* If no expansion is necessary, we're done. */
3421 if (num_result_args < 0)
3422 return args;
3424 /* Expand arguments. */
3425 result_args = make_tree_vec (num_result_args);
3426 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3427 non_default_args_count =
3428 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3429 for (in_arg = 0; in_arg < nargs; ++in_arg)
3431 tree arg = TREE_VEC_ELT (args, in_arg);
3432 if (ARGUMENT_PACK_P (arg))
3434 tree packed = ARGUMENT_PACK_ARGS (arg);
3435 int i, num_packed = TREE_VEC_LENGTH (packed);
3436 for (i = 0; i < num_packed; ++i, ++out_arg)
3437 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3438 if (non_default_args_count > 0)
3439 non_default_args_count += num_packed;
3441 else
3443 TREE_VEC_ELT (result_args, out_arg) = arg;
3444 ++out_arg;
3447 if (non_default_args_count >= 0)
3448 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3449 return result_args;
3452 /* Checks if DECL shadows a template parameter.
3454 [temp.local]: A template-parameter shall not be redeclared within its
3455 scope (including nested scopes).
3457 Emits an error and returns TRUE if the DECL shadows a parameter,
3458 returns FALSE otherwise. */
3460 bool
3461 check_template_shadow (tree decl)
3463 tree olddecl;
3465 /* If we're not in a template, we can't possibly shadow a template
3466 parameter. */
3467 if (!current_template_parms)
3468 return true;
3470 /* Figure out what we're shadowing. */
3471 if (TREE_CODE (decl) == OVERLOAD)
3472 decl = OVL_CURRENT (decl);
3473 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3475 /* If there's no previous binding for this name, we're not shadowing
3476 anything, let alone a template parameter. */
3477 if (!olddecl)
3478 return true;
3480 /* If we're not shadowing a template parameter, we're done. Note
3481 that OLDDECL might be an OVERLOAD (or perhaps even an
3482 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3483 node. */
3484 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3485 return true;
3487 /* We check for decl != olddecl to avoid bogus errors for using a
3488 name inside a class. We check TPFI to avoid duplicate errors for
3489 inline member templates. */
3490 if (decl == olddecl
3491 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3492 return true;
3494 error ("declaration of %q+#D", decl);
3495 error (" shadows template parm %q+#D", olddecl);
3496 return false;
3499 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3500 ORIG_LEVEL, DECL, and TYPE. */
3502 static tree
3503 build_template_parm_index (int index,
3504 int level,
3505 int orig_level,
3506 tree decl,
3507 tree type)
3509 tree t = make_node (TEMPLATE_PARM_INDEX);
3510 TEMPLATE_PARM_IDX (t) = index;
3511 TEMPLATE_PARM_LEVEL (t) = level;
3512 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3513 TEMPLATE_PARM_DECL (t) = decl;
3514 TREE_TYPE (t) = type;
3515 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3516 TREE_READONLY (t) = TREE_READONLY (decl);
3518 return t;
3521 /* Find the canonical type parameter for the given template type
3522 parameter. Returns the canonical type parameter, which may be TYPE
3523 if no such parameter existed. */
3525 static tree
3526 canonical_type_parameter (tree type)
3528 tree list;
3529 int idx = TEMPLATE_TYPE_IDX (type);
3530 if (!canonical_template_parms)
3531 vec_alloc (canonical_template_parms, idx+1);
3533 while (canonical_template_parms->length () <= (unsigned)idx)
3534 vec_safe_push (canonical_template_parms, NULL_TREE);
3536 list = (*canonical_template_parms)[idx];
3537 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3538 list = TREE_CHAIN (list);
3540 if (list)
3541 return TREE_VALUE (list);
3542 else
3544 (*canonical_template_parms)[idx]
3545 = tree_cons (NULL_TREE, type,
3546 (*canonical_template_parms)[idx]);
3547 return type;
3551 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3552 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3553 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3554 new one is created. */
3556 static tree
3557 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3558 tsubst_flags_t complain)
3560 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3561 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3562 != TEMPLATE_PARM_LEVEL (index) - levels)
3563 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3565 tree orig_decl = TEMPLATE_PARM_DECL (index);
3566 tree decl, t;
3568 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3569 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3570 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3571 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3572 DECL_ARTIFICIAL (decl) = 1;
3573 SET_DECL_TEMPLATE_PARM_P (decl);
3575 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3576 TEMPLATE_PARM_LEVEL (index) - levels,
3577 TEMPLATE_PARM_ORIG_LEVEL (index),
3578 decl, type);
3579 TEMPLATE_PARM_DESCENDANTS (index) = t;
3580 TEMPLATE_PARM_PARAMETER_PACK (t)
3581 = TEMPLATE_PARM_PARAMETER_PACK (index);
3583 /* Template template parameters need this. */
3584 if (TREE_CODE (decl) == TEMPLATE_DECL)
3585 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3586 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3587 args, complain);
3590 return TEMPLATE_PARM_DESCENDANTS (index);
3593 /* Process information from new template parameter PARM and append it
3594 to the LIST being built. This new parameter is a non-type
3595 parameter iff IS_NON_TYPE is true. This new parameter is a
3596 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3597 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3598 parameter list PARM belongs to. This is used used to create a
3599 proper canonical type for the type of PARM that is to be created,
3600 iff PARM is a type. If the size is not known, this parameter shall
3601 be set to 0. */
3603 tree
3604 process_template_parm (tree list, location_t parm_loc, tree parm,
3605 bool is_non_type, bool is_parameter_pack)
3607 tree decl = 0;
3608 tree defval;
3609 tree err_parm_list;
3610 int idx = 0;
3612 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3613 defval = TREE_PURPOSE (parm);
3615 if (list)
3617 tree p = tree_last (list);
3619 if (p && TREE_VALUE (p) != error_mark_node)
3621 p = TREE_VALUE (p);
3622 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3623 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3624 else
3625 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3628 ++idx;
3630 else
3631 idx = 0;
3633 if (is_non_type)
3635 parm = TREE_VALUE (parm);
3637 SET_DECL_TEMPLATE_PARM_P (parm);
3639 if (TREE_TYPE (parm) == error_mark_node)
3641 err_parm_list = build_tree_list (defval, parm);
3642 TREE_VALUE (err_parm_list) = error_mark_node;
3643 return chainon (list, err_parm_list);
3645 else
3647 /* [temp.param]
3649 The top-level cv-qualifiers on the template-parameter are
3650 ignored when determining its type. */
3651 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3652 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3654 err_parm_list = build_tree_list (defval, parm);
3655 TREE_VALUE (err_parm_list) = error_mark_node;
3656 return chainon (list, err_parm_list);
3659 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3661 /* This template parameter is not a parameter pack, but it
3662 should be. Complain about "bare" parameter packs. */
3663 check_for_bare_parameter_packs (TREE_TYPE (parm));
3665 /* Recover by calling this a parameter pack. */
3666 is_parameter_pack = true;
3670 /* A template parameter is not modifiable. */
3671 TREE_CONSTANT (parm) = 1;
3672 TREE_READONLY (parm) = 1;
3673 decl = build_decl (parm_loc,
3674 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3675 TREE_CONSTANT (decl) = 1;
3676 TREE_READONLY (decl) = 1;
3677 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3678 = build_template_parm_index (idx, processing_template_decl,
3679 processing_template_decl,
3680 decl, TREE_TYPE (parm));
3682 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3683 = is_parameter_pack;
3685 else
3687 tree t;
3688 parm = TREE_VALUE (TREE_VALUE (parm));
3690 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3692 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3693 /* This is for distinguishing between real templates and template
3694 template parameters */
3695 TREE_TYPE (parm) = t;
3696 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3697 decl = parm;
3699 else
3701 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3702 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3703 decl = build_decl (parm_loc,
3704 TYPE_DECL, parm, t);
3707 TYPE_NAME (t) = decl;
3708 TYPE_STUB_DECL (t) = decl;
3709 parm = decl;
3710 TEMPLATE_TYPE_PARM_INDEX (t)
3711 = build_template_parm_index (idx, processing_template_decl,
3712 processing_template_decl,
3713 decl, TREE_TYPE (parm));
3714 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3715 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3717 DECL_ARTIFICIAL (decl) = 1;
3718 SET_DECL_TEMPLATE_PARM_P (decl);
3719 pushdecl (decl);
3720 parm = build_tree_list (defval, parm);
3721 return chainon (list, parm);
3724 /* The end of a template parameter list has been reached. Process the
3725 tree list into a parameter vector, converting each parameter into a more
3726 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3727 as PARM_DECLs. */
3729 tree
3730 end_template_parm_list (tree parms)
3732 int nparms;
3733 tree parm, next;
3734 tree saved_parmlist = make_tree_vec (list_length (parms));
3736 current_template_parms
3737 = tree_cons (size_int (processing_template_decl),
3738 saved_parmlist, current_template_parms);
3740 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3742 next = TREE_CHAIN (parm);
3743 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3744 TREE_CHAIN (parm) = NULL_TREE;
3747 --processing_template_parmlist;
3749 return saved_parmlist;
3752 /* end_template_decl is called after a template declaration is seen. */
3754 void
3755 end_template_decl (void)
3757 reset_specialization ();
3759 if (! processing_template_decl)
3760 return;
3762 /* This matches the pushlevel in begin_template_parm_list. */
3763 finish_scope ();
3765 --processing_template_decl;
3766 current_template_parms = TREE_CHAIN (current_template_parms);
3769 /* Takes a TREE_LIST representing a template parameter and convert it
3770 into an argument suitable to be passed to the type substitution
3771 functions. Note that If the TREE_LIST contains an error_mark
3772 node, the returned argument is error_mark_node. */
3774 static tree
3775 template_parm_to_arg (tree t)
3778 if (t == NULL_TREE
3779 || TREE_CODE (t) != TREE_LIST)
3780 return t;
3782 if (error_operand_p (TREE_VALUE (t)))
3783 return error_mark_node;
3785 t = TREE_VALUE (t);
3787 if (TREE_CODE (t) == TYPE_DECL
3788 || TREE_CODE (t) == TEMPLATE_DECL)
3790 t = TREE_TYPE (t);
3792 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3794 /* Turn this argument into a TYPE_ARGUMENT_PACK
3795 with a single element, which expands T. */
3796 tree vec = make_tree_vec (1);
3797 #ifdef ENABLE_CHECKING
3798 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3799 (vec, TREE_VEC_LENGTH (vec));
3800 #endif
3801 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3803 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3804 SET_ARGUMENT_PACK_ARGS (t, vec);
3807 else
3809 t = DECL_INITIAL (t);
3811 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3813 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3814 with a single element, which expands T. */
3815 tree vec = make_tree_vec (1);
3816 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3817 #ifdef ENABLE_CHECKING
3818 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3819 (vec, TREE_VEC_LENGTH (vec));
3820 #endif
3821 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3823 t = make_node (NONTYPE_ARGUMENT_PACK);
3824 SET_ARGUMENT_PACK_ARGS (t, vec);
3825 TREE_TYPE (t) = type;
3828 return t;
3831 /* Given a set of template parameters, return them as a set of template
3832 arguments. The template parameters are represented as a TREE_VEC, in
3833 the form documented in cp-tree.h for template arguments. */
3835 static tree
3836 template_parms_to_args (tree parms)
3838 tree header;
3839 tree args = NULL_TREE;
3840 int length = TMPL_PARMS_DEPTH (parms);
3841 int l = length;
3843 /* If there is only one level of template parameters, we do not
3844 create a TREE_VEC of TREE_VECs. Instead, we return a single
3845 TREE_VEC containing the arguments. */
3846 if (length > 1)
3847 args = make_tree_vec (length);
3849 for (header = parms; header; header = TREE_CHAIN (header))
3851 tree a = copy_node (TREE_VALUE (header));
3852 int i;
3854 TREE_TYPE (a) = NULL_TREE;
3855 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3856 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
3858 #ifdef ENABLE_CHECKING
3859 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
3860 #endif
3862 if (length > 1)
3863 TREE_VEC_ELT (args, --l) = a;
3864 else
3865 args = a;
3868 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
3869 /* This can happen for template parms of a template template
3870 parameter, e.g:
3872 template<template<class T, class U> class TT> struct S;
3874 Consider the level of the parms of TT; T and U both have
3875 level 2; TT has no template parm of level 1. So in this case
3876 the first element of full_template_args is NULL_TREE. If we
3877 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
3878 of 2. This will make tsubst wrongly consider that T and U
3879 have level 1. Instead, let's create a dummy vector as the
3880 first element of full_template_args so that TMPL_ARG_DEPTH
3881 returns the correct depth for args. */
3882 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
3883 return args;
3886 /* Within the declaration of a template, return the currently active
3887 template parameters as an argument TREE_VEC. */
3889 static tree
3890 current_template_args (void)
3892 return template_parms_to_args (current_template_parms);
3895 /* Update the declared TYPE by doing any lookups which were thought to be
3896 dependent, but are not now that we know the SCOPE of the declarator. */
3898 tree
3899 maybe_update_decl_type (tree orig_type, tree scope)
3901 tree type = orig_type;
3903 if (type == NULL_TREE)
3904 return type;
3906 if (TREE_CODE (orig_type) == TYPE_DECL)
3907 type = TREE_TYPE (type);
3909 if (scope && TYPE_P (scope) && dependent_type_p (scope)
3910 && dependent_type_p (type)
3911 /* Don't bother building up the args in this case. */
3912 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
3914 /* tsubst in the args corresponding to the template parameters,
3915 including auto if present. Most things will be unchanged, but
3916 make_typename_type and tsubst_qualified_id will resolve
3917 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3918 tree args = current_template_args ();
3919 tree auto_node = type_uses_auto (type);
3920 tree pushed;
3921 if (auto_node)
3923 tree auto_vec = make_tree_vec (1);
3924 TREE_VEC_ELT (auto_vec, 0) = auto_node;
3925 args = add_to_template_args (args, auto_vec);
3927 pushed = push_scope (scope);
3928 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
3929 if (pushed)
3930 pop_scope (scope);
3933 if (type == error_mark_node)
3934 return orig_type;
3936 if (TREE_CODE (orig_type) == TYPE_DECL)
3938 if (same_type_p (type, TREE_TYPE (orig_type)))
3939 type = orig_type;
3940 else
3941 type = TYPE_NAME (type);
3943 return type;
3946 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3947 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3948 a member template. Used by push_template_decl below. */
3950 static tree
3951 build_template_decl (tree decl, tree parms, bool member_template_p)
3953 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3954 DECL_TEMPLATE_PARMS (tmpl) = parms;
3955 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3956 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
3957 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3959 return tmpl;
3962 struct template_parm_data
3964 /* The level of the template parameters we are currently
3965 processing. */
3966 int level;
3968 /* The index of the specialization argument we are currently
3969 processing. */
3970 int current_arg;
3972 /* An array whose size is the number of template parameters. The
3973 elements are nonzero if the parameter has been used in any one
3974 of the arguments processed so far. */
3975 int* parms;
3977 /* An array whose size is the number of template arguments. The
3978 elements are nonzero if the argument makes use of template
3979 parameters of this level. */
3980 int* arg_uses_template_parms;
3983 /* Subroutine of push_template_decl used to see if each template
3984 parameter in a partial specialization is used in the explicit
3985 argument list. If T is of the LEVEL given in DATA (which is
3986 treated as a template_parm_data*), then DATA->PARMS is marked
3987 appropriately. */
3989 static int
3990 mark_template_parm (tree t, void* data)
3992 int level;
3993 int idx;
3994 struct template_parm_data* tpd = (struct template_parm_data*) data;
3996 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3998 level = TEMPLATE_PARM_LEVEL (t);
3999 idx = TEMPLATE_PARM_IDX (t);
4001 else
4003 level = TEMPLATE_TYPE_LEVEL (t);
4004 idx = TEMPLATE_TYPE_IDX (t);
4007 if (level == tpd->level)
4009 tpd->parms[idx] = 1;
4010 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4013 /* Return zero so that for_each_template_parm will continue the
4014 traversal of the tree; we want to mark *every* template parm. */
4015 return 0;
4018 /* Process the partial specialization DECL. */
4020 static tree
4021 process_partial_specialization (tree decl)
4023 tree type = TREE_TYPE (decl);
4024 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4025 tree specargs = CLASSTYPE_TI_ARGS (type);
4026 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4027 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4028 tree inner_parms;
4029 tree inst;
4030 int nargs = TREE_VEC_LENGTH (inner_args);
4031 int ntparms;
4032 int i;
4033 bool did_error_intro = false;
4034 struct template_parm_data tpd;
4035 struct template_parm_data tpd2;
4037 gcc_assert (current_template_parms);
4039 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4040 ntparms = TREE_VEC_LENGTH (inner_parms);
4042 /* We check that each of the template parameters given in the
4043 partial specialization is used in the argument list to the
4044 specialization. For example:
4046 template <class T> struct S;
4047 template <class T> struct S<T*>;
4049 The second declaration is OK because `T*' uses the template
4050 parameter T, whereas
4052 template <class T> struct S<int>;
4054 is no good. Even trickier is:
4056 template <class T>
4057 struct S1
4059 template <class U>
4060 struct S2;
4061 template <class U>
4062 struct S2<T>;
4065 The S2<T> declaration is actually invalid; it is a
4066 full-specialization. Of course,
4068 template <class U>
4069 struct S2<T (*)(U)>;
4071 or some such would have been OK. */
4072 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4073 tpd.parms = XALLOCAVEC (int, ntparms);
4074 memset (tpd.parms, 0, sizeof (int) * ntparms);
4076 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4077 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4078 for (i = 0; i < nargs; ++i)
4080 tpd.current_arg = i;
4081 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4082 &mark_template_parm,
4083 &tpd,
4084 NULL,
4085 /*include_nondeduced_p=*/false);
4087 for (i = 0; i < ntparms; ++i)
4088 if (tpd.parms[i] == 0)
4090 /* One of the template parms was not used in the
4091 specialization. */
4092 if (!did_error_intro)
4094 error ("template parameters not used in partial specialization:");
4095 did_error_intro = true;
4098 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4101 if (did_error_intro)
4102 return error_mark_node;
4104 /* [temp.class.spec]
4106 The argument list of the specialization shall not be identical to
4107 the implicit argument list of the primary template. */
4108 if (comp_template_args
4109 (inner_args,
4110 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4111 (maintmpl)))))
4112 error ("partial specialization %qT does not specialize any template arguments", type);
4114 /* A partial specialization that replaces multiple parameters of the
4115 primary template with a pack expansion is less specialized for those
4116 parameters. */
4117 if (nargs < DECL_NTPARMS (maintmpl))
4119 error ("partial specialization is not more specialized than the "
4120 "primary template because it replaces multiple parameters "
4121 "with a pack expansion");
4122 inform (DECL_SOURCE_LOCATION (maintmpl), "primary template here");
4123 return decl;
4126 /* [temp.class.spec]
4128 A partially specialized non-type argument expression shall not
4129 involve template parameters of the partial specialization except
4130 when the argument expression is a simple identifier.
4132 The type of a template parameter corresponding to a specialized
4133 non-type argument shall not be dependent on a parameter of the
4134 specialization.
4136 Also, we verify that pack expansions only occur at the
4137 end of the argument list. */
4138 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4139 tpd2.parms = 0;
4140 for (i = 0; i < nargs; ++i)
4142 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4143 tree arg = TREE_VEC_ELT (inner_args, i);
4144 tree packed_args = NULL_TREE;
4145 int j, len = 1;
4147 if (ARGUMENT_PACK_P (arg))
4149 /* Extract the arguments from the argument pack. We'll be
4150 iterating over these in the following loop. */
4151 packed_args = ARGUMENT_PACK_ARGS (arg);
4152 len = TREE_VEC_LENGTH (packed_args);
4155 for (j = 0; j < len; j++)
4157 if (packed_args)
4158 /* Get the Jth argument in the parameter pack. */
4159 arg = TREE_VEC_ELT (packed_args, j);
4161 if (PACK_EXPANSION_P (arg))
4163 /* Pack expansions must come at the end of the
4164 argument list. */
4165 if ((packed_args && j < len - 1)
4166 || (!packed_args && i < nargs - 1))
4168 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4169 error ("parameter pack argument %qE must be at the "
4170 "end of the template argument list", arg);
4171 else
4172 error ("parameter pack argument %qT must be at the "
4173 "end of the template argument list", arg);
4177 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4178 /* We only care about the pattern. */
4179 arg = PACK_EXPANSION_PATTERN (arg);
4181 if (/* These first two lines are the `non-type' bit. */
4182 !TYPE_P (arg)
4183 && TREE_CODE (arg) != TEMPLATE_DECL
4184 /* This next line is the `argument expression is not just a
4185 simple identifier' condition and also the `specialized
4186 non-type argument' bit. */
4187 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4189 if ((!packed_args && tpd.arg_uses_template_parms[i])
4190 || (packed_args && uses_template_parms (arg)))
4191 error ("template argument %qE involves template parameter(s)",
4192 arg);
4193 else
4195 /* Look at the corresponding template parameter,
4196 marking which template parameters its type depends
4197 upon. */
4198 tree type = TREE_TYPE (parm);
4200 if (!tpd2.parms)
4202 /* We haven't yet initialized TPD2. Do so now. */
4203 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4204 /* The number of parameters here is the number in the
4205 main template, which, as checked in the assertion
4206 above, is NARGS. */
4207 tpd2.parms = XALLOCAVEC (int, nargs);
4208 tpd2.level =
4209 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4212 /* Mark the template parameters. But this time, we're
4213 looking for the template parameters of the main
4214 template, not in the specialization. */
4215 tpd2.current_arg = i;
4216 tpd2.arg_uses_template_parms[i] = 0;
4217 memset (tpd2.parms, 0, sizeof (int) * nargs);
4218 for_each_template_parm (type,
4219 &mark_template_parm,
4220 &tpd2,
4221 NULL,
4222 /*include_nondeduced_p=*/false);
4224 if (tpd2.arg_uses_template_parms [i])
4226 /* The type depended on some template parameters.
4227 If they are fully specialized in the
4228 specialization, that's OK. */
4229 int j;
4230 int count = 0;
4231 for (j = 0; j < nargs; ++j)
4232 if (tpd2.parms[j] != 0
4233 && tpd.arg_uses_template_parms [j])
4234 ++count;
4235 if (count != 0)
4236 error_n (input_location, count,
4237 "type %qT of template argument %qE depends "
4238 "on a template parameter",
4239 "type %qT of template argument %qE depends "
4240 "on template parameters",
4241 type,
4242 arg);
4249 /* We should only get here once. */
4250 gcc_assert (!COMPLETE_TYPE_P (type));
4252 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4253 = tree_cons (specargs, inner_parms,
4254 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4255 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4257 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4258 inst = TREE_CHAIN (inst))
4260 tree inst_type = TREE_VALUE (inst);
4261 if (COMPLETE_TYPE_P (inst_type)
4262 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4264 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4265 if (spec && TREE_TYPE (spec) == type)
4266 permerror (input_location,
4267 "partial specialization of %qT after instantiation "
4268 "of %qT", type, inst_type);
4272 return decl;
4275 /* Check that a template declaration's use of default arguments and
4276 parameter packs is not invalid. Here, PARMS are the template
4277 parameters. IS_PRIMARY is true if DECL is the thing declared by
4278 a primary template. IS_PARTIAL is true if DECL is a partial
4279 specialization.
4281 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4282 declaration (but not a definition); 1 indicates a declaration, 2
4283 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4284 emitted for extraneous default arguments.
4286 Returns TRUE if there were no errors found, FALSE otherwise. */
4288 bool
4289 check_default_tmpl_args (tree decl, tree parms, bool is_primary,
4290 bool is_partial, int is_friend_decl)
4292 const char *msg;
4293 int last_level_to_check;
4294 tree parm_level;
4295 bool no_errors = true;
4297 /* [temp.param]
4299 A default template-argument shall not be specified in a
4300 function template declaration or a function template definition, nor
4301 in the template-parameter-list of the definition of a member of a
4302 class template. */
4304 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4305 /* You can't have a function template declaration in a local
4306 scope, nor you can you define a member of a class template in a
4307 local scope. */
4308 return true;
4310 if (TREE_CODE (decl) == TYPE_DECL
4311 && TREE_TYPE (decl)
4312 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
4313 /* A lambda doesn't have an explicit declaration; don't complain
4314 about the parms of the enclosing class. */
4315 return true;
4317 if (current_class_type
4318 && !TYPE_BEING_DEFINED (current_class_type)
4319 && DECL_LANG_SPECIFIC (decl)
4320 && DECL_DECLARES_FUNCTION_P (decl)
4321 /* If this is either a friend defined in the scope of the class
4322 or a member function. */
4323 && (DECL_FUNCTION_MEMBER_P (decl)
4324 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4325 : DECL_FRIEND_CONTEXT (decl)
4326 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4327 : false)
4328 /* And, if it was a member function, it really was defined in
4329 the scope of the class. */
4330 && (!DECL_FUNCTION_MEMBER_P (decl)
4331 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4332 /* We already checked these parameters when the template was
4333 declared, so there's no need to do it again now. This function
4334 was defined in class scope, but we're processing it's body now
4335 that the class is complete. */
4336 return true;
4338 /* Core issue 226 (C++0x only): the following only applies to class
4339 templates. */
4340 if (is_primary
4341 && ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL))
4343 /* [temp.param]
4345 If a template-parameter has a default template-argument, all
4346 subsequent template-parameters shall have a default
4347 template-argument supplied. */
4348 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4350 tree inner_parms = TREE_VALUE (parm_level);
4351 int ntparms = TREE_VEC_LENGTH (inner_parms);
4352 int seen_def_arg_p = 0;
4353 int i;
4355 for (i = 0; i < ntparms; ++i)
4357 tree parm = TREE_VEC_ELT (inner_parms, i);
4359 if (parm == error_mark_node)
4360 continue;
4362 if (TREE_PURPOSE (parm))
4363 seen_def_arg_p = 1;
4364 else if (seen_def_arg_p
4365 && !template_parameter_pack_p (TREE_VALUE (parm)))
4367 error ("no default argument for %qD", TREE_VALUE (parm));
4368 /* For better subsequent error-recovery, we indicate that
4369 there should have been a default argument. */
4370 TREE_PURPOSE (parm) = error_mark_node;
4371 no_errors = false;
4373 else if (!is_partial
4374 && !is_friend_decl
4375 /* Don't complain about an enclosing partial
4376 specialization. */
4377 && parm_level == parms
4378 && TREE_CODE (decl) == TYPE_DECL
4379 && i < ntparms - 1
4380 && template_parameter_pack_p (TREE_VALUE (parm)))
4382 /* A primary class template can only have one
4383 parameter pack, at the end of the template
4384 parameter list. */
4386 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4387 error ("parameter pack %qE must be at the end of the"
4388 " template parameter list", TREE_VALUE (parm));
4389 else
4390 error ("parameter pack %qT must be at the end of the"
4391 " template parameter list",
4392 TREE_TYPE (TREE_VALUE (parm)));
4394 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4395 = error_mark_node;
4396 no_errors = false;
4402 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4403 || is_partial
4404 || !is_primary
4405 || is_friend_decl)
4406 /* For an ordinary class template, default template arguments are
4407 allowed at the innermost level, e.g.:
4408 template <class T = int>
4409 struct S {};
4410 but, in a partial specialization, they're not allowed even
4411 there, as we have in [temp.class.spec]:
4413 The template parameter list of a specialization shall not
4414 contain default template argument values.
4416 So, for a partial specialization, or for a function template
4417 (in C++98/C++03), we look at all of them. */
4419 else
4420 /* But, for a primary class template that is not a partial
4421 specialization we look at all template parameters except the
4422 innermost ones. */
4423 parms = TREE_CHAIN (parms);
4425 /* Figure out what error message to issue. */
4426 if (is_friend_decl == 2)
4427 msg = G_("default template arguments may not be used in function template "
4428 "friend re-declaration");
4429 else if (is_friend_decl)
4430 msg = G_("default template arguments may not be used in function template "
4431 "friend declarations");
4432 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4433 msg = G_("default template arguments may not be used in function templates "
4434 "without -std=c++11 or -std=gnu++11");
4435 else if (is_partial)
4436 msg = G_("default template arguments may not be used in "
4437 "partial specializations");
4438 else
4439 msg = G_("default argument for template parameter for class enclosing %qD");
4441 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4442 /* If we're inside a class definition, there's no need to
4443 examine the parameters to the class itself. On the one
4444 hand, they will be checked when the class is defined, and,
4445 on the other, default arguments are valid in things like:
4446 template <class T = double>
4447 struct S { template <class U> void f(U); };
4448 Here the default argument for `S' has no bearing on the
4449 declaration of `f'. */
4450 last_level_to_check = template_class_depth (current_class_type) + 1;
4451 else
4452 /* Check everything. */
4453 last_level_to_check = 0;
4455 for (parm_level = parms;
4456 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4457 parm_level = TREE_CHAIN (parm_level))
4459 tree inner_parms = TREE_VALUE (parm_level);
4460 int i;
4461 int ntparms;
4463 ntparms = TREE_VEC_LENGTH (inner_parms);
4464 for (i = 0; i < ntparms; ++i)
4466 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4467 continue;
4469 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4471 if (msg)
4473 no_errors = false;
4474 if (is_friend_decl == 2)
4475 return no_errors;
4477 error (msg, decl);
4478 msg = 0;
4481 /* Clear out the default argument so that we are not
4482 confused later. */
4483 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4487 /* At this point, if we're still interested in issuing messages,
4488 they must apply to classes surrounding the object declared. */
4489 if (msg)
4490 msg = G_("default argument for template parameter for class "
4491 "enclosing %qD");
4494 return no_errors;
4497 /* Worker for push_template_decl_real, called via
4498 for_each_template_parm. DATA is really an int, indicating the
4499 level of the parameters we are interested in. If T is a template
4500 parameter of that level, return nonzero. */
4502 static int
4503 template_parm_this_level_p (tree t, void* data)
4505 int this_level = *(int *)data;
4506 int level;
4508 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4509 level = TEMPLATE_PARM_LEVEL (t);
4510 else
4511 level = TEMPLATE_TYPE_LEVEL (t);
4512 return level == this_level;
4515 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4516 parameters given by current_template_args, or reuses a
4517 previously existing one, if appropriate. Returns the DECL, or an
4518 equivalent one, if it is replaced via a call to duplicate_decls.
4520 If IS_FRIEND is true, DECL is a friend declaration. */
4522 tree
4523 push_template_decl_real (tree decl, bool is_friend)
4525 tree tmpl;
4526 tree args;
4527 tree info;
4528 tree ctx;
4529 bool is_primary;
4530 bool is_partial;
4531 int new_template_p = 0;
4532 /* True if the template is a member template, in the sense of
4533 [temp.mem]. */
4534 bool member_template_p = false;
4536 if (decl == error_mark_node || !current_template_parms)
4537 return error_mark_node;
4539 /* See if this is a partial specialization. */
4540 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4541 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4542 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4544 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4545 is_friend = true;
4547 if (is_friend)
4548 /* For a friend, we want the context of the friend function, not
4549 the type of which it is a friend. */
4550 ctx = CP_DECL_CONTEXT (decl);
4551 else if (CP_DECL_CONTEXT (decl)
4552 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4553 /* In the case of a virtual function, we want the class in which
4554 it is defined. */
4555 ctx = CP_DECL_CONTEXT (decl);
4556 else
4557 /* Otherwise, if we're currently defining some class, the DECL
4558 is assumed to be a member of the class. */
4559 ctx = current_scope ();
4561 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4562 ctx = NULL_TREE;
4564 if (!DECL_CONTEXT (decl))
4565 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4567 /* See if this is a primary template. */
4568 if (is_friend && ctx)
4569 /* A friend template that specifies a class context, i.e.
4570 template <typename T> friend void A<T>::f();
4571 is not primary. */
4572 is_primary = false;
4573 else
4574 is_primary = template_parm_scope_p ();
4576 if (is_primary)
4578 if (DECL_CLASS_SCOPE_P (decl))
4579 member_template_p = true;
4580 if (TREE_CODE (decl) == TYPE_DECL
4581 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4583 error ("template class without a name");
4584 return error_mark_node;
4586 else if (TREE_CODE (decl) == FUNCTION_DECL)
4588 if (DECL_DESTRUCTOR_P (decl))
4590 /* [temp.mem]
4592 A destructor shall not be a member template. */
4593 error ("destructor %qD declared as member template", decl);
4594 return error_mark_node;
4596 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4597 && (!prototype_p (TREE_TYPE (decl))
4598 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4599 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4600 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4601 == void_list_node)))
4603 /* [basic.stc.dynamic.allocation]
4605 An allocation function can be a function
4606 template. ... Template allocation functions shall
4607 have two or more parameters. */
4608 error ("invalid template declaration of %qD", decl);
4609 return error_mark_node;
4612 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4613 && CLASS_TYPE_P (TREE_TYPE (decl)))
4614 /* OK */;
4615 else if (TREE_CODE (decl) == TYPE_DECL
4616 && TYPE_DECL_ALIAS_P (decl))
4617 /* alias-declaration */
4618 gcc_assert (!DECL_ARTIFICIAL (decl));
4619 else
4621 error ("template declaration of %q#D", decl);
4622 return error_mark_node;
4626 /* Check to see that the rules regarding the use of default
4627 arguments are not being violated. */
4628 check_default_tmpl_args (decl, current_template_parms,
4629 is_primary, is_partial, /*is_friend_decl=*/0);
4631 /* Ensure that there are no parameter packs in the type of this
4632 declaration that have not been expanded. */
4633 if (TREE_CODE (decl) == FUNCTION_DECL)
4635 /* Check each of the arguments individually to see if there are
4636 any bare parameter packs. */
4637 tree type = TREE_TYPE (decl);
4638 tree arg = DECL_ARGUMENTS (decl);
4639 tree argtype = TYPE_ARG_TYPES (type);
4641 while (arg && argtype)
4643 if (!FUNCTION_PARAMETER_PACK_P (arg)
4644 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4646 /* This is a PARM_DECL that contains unexpanded parameter
4647 packs. We have already complained about this in the
4648 check_for_bare_parameter_packs call, so just replace
4649 these types with ERROR_MARK_NODE. */
4650 TREE_TYPE (arg) = error_mark_node;
4651 TREE_VALUE (argtype) = error_mark_node;
4654 arg = DECL_CHAIN (arg);
4655 argtype = TREE_CHAIN (argtype);
4658 /* Check for bare parameter packs in the return type and the
4659 exception specifiers. */
4660 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4661 /* Errors were already issued, set return type to int
4662 as the frontend doesn't expect error_mark_node as
4663 the return type. */
4664 TREE_TYPE (type) = integer_type_node;
4665 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4666 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4668 else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
4669 && TYPE_DECL_ALIAS_P (decl))
4670 ? DECL_ORIGINAL_TYPE (decl)
4671 : TREE_TYPE (decl)))
4673 TREE_TYPE (decl) = error_mark_node;
4674 return error_mark_node;
4677 if (is_partial)
4678 return process_partial_specialization (decl);
4680 args = current_template_args ();
4682 if (!ctx
4683 || TREE_CODE (ctx) == FUNCTION_DECL
4684 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4685 || (TREE_CODE (decl) == TYPE_DECL
4686 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
4687 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4689 if (DECL_LANG_SPECIFIC (decl)
4690 && DECL_TEMPLATE_INFO (decl)
4691 && DECL_TI_TEMPLATE (decl))
4692 tmpl = DECL_TI_TEMPLATE (decl);
4693 /* If DECL is a TYPE_DECL for a class-template, then there won't
4694 be DECL_LANG_SPECIFIC. The information equivalent to
4695 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4696 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4697 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4698 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4700 /* Since a template declaration already existed for this
4701 class-type, we must be redeclaring it here. Make sure
4702 that the redeclaration is valid. */
4703 redeclare_class_template (TREE_TYPE (decl),
4704 current_template_parms);
4705 /* We don't need to create a new TEMPLATE_DECL; just use the
4706 one we already had. */
4707 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4709 else
4711 tmpl = build_template_decl (decl, current_template_parms,
4712 member_template_p);
4713 new_template_p = 1;
4715 if (DECL_LANG_SPECIFIC (decl)
4716 && DECL_TEMPLATE_SPECIALIZATION (decl))
4718 /* A specialization of a member template of a template
4719 class. */
4720 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4721 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4722 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4726 else
4728 tree a, t, current, parms;
4729 int i;
4730 tree tinfo = get_template_info (decl);
4732 if (!tinfo)
4734 error ("template definition of non-template %q#D", decl);
4735 return error_mark_node;
4738 tmpl = TI_TEMPLATE (tinfo);
4740 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4741 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4742 && DECL_TEMPLATE_SPECIALIZATION (decl)
4743 && DECL_MEMBER_TEMPLATE_P (tmpl))
4745 tree new_tmpl;
4747 /* The declaration is a specialization of a member
4748 template, declared outside the class. Therefore, the
4749 innermost template arguments will be NULL, so we
4750 replace them with the arguments determined by the
4751 earlier call to check_explicit_specialization. */
4752 args = DECL_TI_ARGS (decl);
4754 new_tmpl
4755 = build_template_decl (decl, current_template_parms,
4756 member_template_p);
4757 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4758 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4759 DECL_TI_TEMPLATE (decl) = new_tmpl;
4760 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4761 DECL_TEMPLATE_INFO (new_tmpl)
4762 = build_template_info (tmpl, args);
4764 register_specialization (new_tmpl,
4765 most_general_template (tmpl),
4766 args,
4767 is_friend, 0);
4768 return decl;
4771 /* Make sure the template headers we got make sense. */
4773 parms = DECL_TEMPLATE_PARMS (tmpl);
4774 i = TMPL_PARMS_DEPTH (parms);
4775 if (TMPL_ARGS_DEPTH (args) != i)
4777 error ("expected %d levels of template parms for %q#D, got %d",
4778 i, decl, TMPL_ARGS_DEPTH (args));
4780 else
4781 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4783 a = TMPL_ARGS_LEVEL (args, i);
4784 t = INNERMOST_TEMPLATE_PARMS (parms);
4786 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4788 if (current == decl)
4789 error ("got %d template parameters for %q#D",
4790 TREE_VEC_LENGTH (a), decl);
4791 else
4792 error ("got %d template parameters for %q#T",
4793 TREE_VEC_LENGTH (a), current);
4794 error (" but %d required", TREE_VEC_LENGTH (t));
4795 /* Avoid crash in import_export_decl. */
4796 DECL_INTERFACE_KNOWN (decl) = 1;
4797 return error_mark_node;
4800 if (current == decl)
4801 current = ctx;
4802 else if (current == NULL_TREE)
4803 /* Can happen in erroneous input. */
4804 break;
4805 else
4806 current = (TYPE_P (current)
4807 ? TYPE_CONTEXT (current)
4808 : DECL_CONTEXT (current));
4811 /* Check that the parms are used in the appropriate qualifying scopes
4812 in the declarator. */
4813 if (!comp_template_args
4814 (TI_ARGS (tinfo),
4815 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4817 error ("\
4818 template arguments to %qD do not match original template %qD",
4819 decl, DECL_TEMPLATE_RESULT (tmpl));
4820 if (!uses_template_parms (TI_ARGS (tinfo)))
4821 inform (input_location, "use template<> for an explicit specialization");
4822 /* Avoid crash in import_export_decl. */
4823 DECL_INTERFACE_KNOWN (decl) = 1;
4824 return error_mark_node;
4828 DECL_TEMPLATE_RESULT (tmpl) = decl;
4829 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4831 /* Push template declarations for global functions and types. Note
4832 that we do not try to push a global template friend declared in a
4833 template class; such a thing may well depend on the template
4834 parameters of the class. */
4835 if (new_template_p && !ctx
4836 && !(is_friend && template_class_depth (current_class_type) > 0))
4838 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4839 if (tmpl == error_mark_node)
4840 return error_mark_node;
4842 /* Hide template friend classes that haven't been declared yet. */
4843 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4845 DECL_ANTICIPATED (tmpl) = 1;
4846 DECL_FRIEND_P (tmpl) = 1;
4850 if (is_primary)
4852 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4853 int i;
4855 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4856 if (DECL_CONV_FN_P (tmpl))
4858 int depth = TMPL_PARMS_DEPTH (parms);
4860 /* It is a conversion operator. See if the type converted to
4861 depends on innermost template operands. */
4863 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4864 depth))
4865 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4868 /* Give template template parms a DECL_CONTEXT of the template
4869 for which they are a parameter. */
4870 parms = INNERMOST_TEMPLATE_PARMS (parms);
4871 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4873 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4874 if (TREE_CODE (parm) == TEMPLATE_DECL)
4875 DECL_CONTEXT (parm) = tmpl;
4879 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4880 back to its most general template. If TMPL is a specialization,
4881 ARGS may only have the innermost set of arguments. Add the missing
4882 argument levels if necessary. */
4883 if (DECL_TEMPLATE_INFO (tmpl))
4884 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4886 info = build_template_info (tmpl, args);
4888 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4889 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4890 else
4892 if (is_primary && !DECL_LANG_SPECIFIC (decl))
4893 retrofit_lang_decl (decl);
4894 if (DECL_LANG_SPECIFIC (decl))
4895 DECL_TEMPLATE_INFO (decl) = info;
4898 return DECL_TEMPLATE_RESULT (tmpl);
4901 tree
4902 push_template_decl (tree decl)
4904 return push_template_decl_real (decl, false);
4907 /* FN is an inheriting constructor that inherits from the constructor
4908 template INHERITED; turn FN into a constructor template with a matching
4909 template header. */
4911 tree
4912 add_inherited_template_parms (tree fn, tree inherited)
4914 tree inner_parms
4915 = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (inherited));
4916 inner_parms = copy_node (inner_parms);
4917 tree parms
4918 = tree_cons (size_int (processing_template_decl + 1),
4919 inner_parms, current_template_parms);
4920 tree tmpl = build_template_decl (fn, parms, /*member*/true);
4921 tree args = template_parms_to_args (parms);
4922 DECL_TEMPLATE_INFO (fn) = build_template_info (tmpl, args);
4923 TREE_TYPE (tmpl) = TREE_TYPE (fn);
4924 DECL_TEMPLATE_RESULT (tmpl) = fn;
4925 DECL_ARTIFICIAL (tmpl) = true;
4926 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4927 return tmpl;
4930 /* Called when a class template TYPE is redeclared with the indicated
4931 template PARMS, e.g.:
4933 template <class T> struct S;
4934 template <class T> struct S {}; */
4936 bool
4937 redeclare_class_template (tree type, tree parms)
4939 tree tmpl;
4940 tree tmpl_parms;
4941 int i;
4943 if (!TYPE_TEMPLATE_INFO (type))
4945 error ("%qT is not a template type", type);
4946 return false;
4949 tmpl = TYPE_TI_TEMPLATE (type);
4950 if (!PRIMARY_TEMPLATE_P (tmpl))
4951 /* The type is nested in some template class. Nothing to worry
4952 about here; there are no new template parameters for the nested
4953 type. */
4954 return true;
4956 if (!parms)
4958 error ("template specifiers not specified in declaration of %qD",
4959 tmpl);
4960 return false;
4963 parms = INNERMOST_TEMPLATE_PARMS (parms);
4964 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4966 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4968 error_n (input_location, TREE_VEC_LENGTH (parms),
4969 "redeclared with %d template parameter",
4970 "redeclared with %d template parameters",
4971 TREE_VEC_LENGTH (parms));
4972 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
4973 "previous declaration %q+D used %d template parameter",
4974 "previous declaration %q+D used %d template parameters",
4975 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4976 return false;
4979 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4981 tree tmpl_parm;
4982 tree parm;
4983 tree tmpl_default;
4984 tree parm_default;
4986 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4987 || TREE_VEC_ELT (parms, i) == error_mark_node)
4988 continue;
4990 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4991 if (tmpl_parm == error_mark_node)
4992 return false;
4994 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4995 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4996 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4998 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4999 TEMPLATE_DECL. */
5000 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5001 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5002 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5003 || (TREE_CODE (tmpl_parm) != PARM_DECL
5004 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5005 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5006 || (TREE_CODE (tmpl_parm) == PARM_DECL
5007 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5008 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5010 error ("template parameter %q+#D", tmpl_parm);
5011 error ("redeclared here as %q#D", parm);
5012 return false;
5015 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5017 /* We have in [temp.param]:
5019 A template-parameter may not be given default arguments
5020 by two different declarations in the same scope. */
5021 error_at (input_location, "redefinition of default argument for %q#D", parm);
5022 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5023 "original definition appeared here");
5024 return false;
5027 if (parm_default != NULL_TREE)
5028 /* Update the previous template parameters (which are the ones
5029 that will really count) with the new default value. */
5030 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5031 else if (tmpl_default != NULL_TREE)
5032 /* Update the new parameters, too; they'll be used as the
5033 parameters for any members. */
5034 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5037 return true;
5040 /* Simplify EXPR if it is a non-dependent expression. Returns the
5041 (possibly simplified) expression. */
5043 tree
5044 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5046 if (expr == NULL_TREE)
5047 return NULL_TREE;
5049 /* If we're in a template, but EXPR isn't value dependent, simplify
5050 it. We're supposed to treat:
5052 template <typename T> void f(T[1 + 1]);
5053 template <typename T> void f(T[2]);
5055 as two declarations of the same function, for example. */
5056 if (processing_template_decl
5057 && !instantiation_dependent_expression_p (expr)
5058 && potential_constant_expression (expr))
5060 HOST_WIDE_INT saved_processing_template_decl;
5062 saved_processing_template_decl = processing_template_decl;
5063 processing_template_decl = 0;
5064 expr = tsubst_copy_and_build (expr,
5065 /*args=*/NULL_TREE,
5066 complain,
5067 /*in_decl=*/NULL_TREE,
5068 /*function_p=*/false,
5069 /*integral_constant_expression_p=*/true);
5070 processing_template_decl = saved_processing_template_decl;
5072 return expr;
5075 tree
5076 fold_non_dependent_expr (tree expr)
5078 return fold_non_dependent_expr_sfinae (expr, tf_error);
5081 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5082 template declaration, or a TYPE_DECL for an alias declaration. */
5084 bool
5085 alias_type_or_template_p (tree t)
5087 if (t == NULL_TREE)
5088 return false;
5089 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5090 || (TYPE_P (t)
5091 && TYPE_NAME (t)
5092 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5093 || DECL_ALIAS_TEMPLATE_P (t));
5096 /* Return TRUE iff is a specialization of an alias template. */
5098 bool
5099 alias_template_specialization_p (const_tree t)
5101 if (t == NULL_TREE)
5102 return false;
5104 return (TYPE_P (t)
5105 && TYPE_TEMPLATE_INFO (t)
5106 && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t))
5107 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t)));
5110 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5111 must be a function or a pointer-to-function type, as specified
5112 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5113 and check that the resulting function has external linkage. */
5115 static tree
5116 convert_nontype_argument_function (tree type, tree expr)
5118 tree fns = expr;
5119 tree fn, fn_no_ptr;
5120 linkage_kind linkage;
5122 fn = instantiate_type (type, fns, tf_none);
5123 if (fn == error_mark_node)
5124 return error_mark_node;
5126 fn_no_ptr = fn;
5127 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5128 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5129 if (BASELINK_P (fn_no_ptr))
5130 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5132 /* [temp.arg.nontype]/1
5134 A template-argument for a non-type, non-template template-parameter
5135 shall be one of:
5136 [...]
5137 -- the address of an object or function with external [C++11: or
5138 internal] linkage. */
5140 if (TREE_CODE (fn_no_ptr) != FUNCTION_DECL)
5142 error ("%qE is not a valid template argument for type %qT", expr, type);
5143 if (TREE_CODE (type) == POINTER_TYPE)
5144 error ("it must be the address of a function with external linkage");
5145 else
5146 error ("it must be the name of a function with external linkage");
5147 return NULL_TREE;
5150 linkage = decl_linkage (fn_no_ptr);
5151 if (cxx_dialect >= cxx0x ? linkage == lk_none : linkage != lk_external)
5153 if (cxx_dialect >= cxx0x)
5154 error ("%qE is not a valid template argument for type %qT "
5155 "because %qD has no linkage",
5156 expr, type, fn_no_ptr);
5157 else
5158 error ("%qE is not a valid template argument for type %qT "
5159 "because %qD does not have external linkage",
5160 expr, type, fn_no_ptr);
5161 return NULL_TREE;
5164 return fn;
5167 /* Subroutine of convert_nontype_argument.
5168 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5169 Emit an error otherwise. */
5171 static bool
5172 check_valid_ptrmem_cst_expr (tree type, tree expr,
5173 tsubst_flags_t complain)
5175 STRIP_NOPS (expr);
5176 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5177 return true;
5178 if (cxx_dialect >= cxx0x && null_member_pointer_value_p (expr))
5179 return true;
5180 if (complain & tf_error)
5182 error ("%qE is not a valid template argument for type %qT",
5183 expr, type);
5184 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5186 return false;
5189 /* Returns TRUE iff the address of OP is value-dependent.
5191 14.6.2.4 [temp.dep.temp]:
5192 A non-integral non-type template-argument is dependent if its type is
5193 dependent or it has either of the following forms
5194 qualified-id
5195 & qualified-id
5196 and contains a nested-name-specifier which specifies a class-name that
5197 names a dependent type.
5199 We generalize this to just say that the address of a member of a
5200 dependent class is value-dependent; the above doesn't cover the
5201 address of a static data member named with an unqualified-id. */
5203 static bool
5204 has_value_dependent_address (tree op)
5206 /* We could use get_inner_reference here, but there's no need;
5207 this is only relevant for template non-type arguments, which
5208 can only be expressed as &id-expression. */
5209 if (DECL_P (op))
5211 tree ctx = CP_DECL_CONTEXT (op);
5212 if (TYPE_P (ctx) && dependent_type_p (ctx))
5213 return true;
5216 return false;
5219 /* The next set of functions are used for providing helpful explanatory
5220 diagnostics for failed overload resolution. Their messages should be
5221 indented by two spaces for consistency with the messages in
5222 call.c */
5224 static int
5225 unify_success (bool /*explain_p*/)
5227 return 0;
5230 static int
5231 unify_parameter_deduction_failure (bool explain_p, tree parm)
5233 if (explain_p)
5234 inform (input_location,
5235 " couldn't deduce template parameter %qD", parm);
5236 return 1;
5239 static int
5240 unify_invalid (bool /*explain_p*/)
5242 return 1;
5245 static int
5246 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5248 if (explain_p)
5249 inform (input_location,
5250 " types %qT and %qT have incompatible cv-qualifiers",
5251 parm, arg);
5252 return 1;
5255 static int
5256 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5258 if (explain_p)
5259 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5260 return 1;
5263 static int
5264 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5266 if (explain_p)
5267 inform (input_location,
5268 " template parameter %qD is not a parameter pack, but "
5269 "argument %qD is",
5270 parm, arg);
5271 return 1;
5274 static int
5275 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5277 if (explain_p)
5278 inform (input_location,
5279 " template argument %qE does not match "
5280 "pointer-to-member constant %qE",
5281 arg, parm);
5282 return 1;
5285 static int
5286 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5288 if (explain_p)
5289 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5290 return 1;
5293 static int
5294 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5296 if (explain_p)
5297 inform (input_location,
5298 " inconsistent parameter pack deduction with %qT and %qT",
5299 old_arg, new_arg);
5300 return 1;
5303 static int
5304 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5306 if (explain_p)
5308 if (TYPE_P (parm))
5309 inform (input_location,
5310 " deduced conflicting types for parameter %qT (%qT and %qT)",
5311 parm, first, second);
5312 else
5313 inform (input_location,
5314 " deduced conflicting values for non-type parameter "
5315 "%qE (%qE and %qE)", parm, first, second);
5317 return 1;
5320 static int
5321 unify_vla_arg (bool explain_p, tree arg)
5323 if (explain_p)
5324 inform (input_location,
5325 " variable-sized array type %qT is not "
5326 "a valid template argument",
5327 arg);
5328 return 1;
5331 static int
5332 unify_method_type_error (bool explain_p, tree arg)
5334 if (explain_p)
5335 inform (input_location,
5336 " member function type %qT is not a valid template argument",
5337 arg);
5338 return 1;
5341 static int
5342 unify_arity (bool explain_p, int have, int wanted)
5344 if (explain_p)
5345 inform_n (input_location, wanted,
5346 " candidate expects %d argument, %d provided",
5347 " candidate expects %d arguments, %d provided",
5348 wanted, have);
5349 return 1;
5352 static int
5353 unify_too_many_arguments (bool explain_p, int have, int wanted)
5355 return unify_arity (explain_p, have, wanted);
5358 static int
5359 unify_too_few_arguments (bool explain_p, int have, int wanted)
5361 return unify_arity (explain_p, have, wanted);
5364 static int
5365 unify_arg_conversion (bool explain_p, tree to_type,
5366 tree from_type, tree arg)
5368 if (explain_p)
5369 inform (input_location, " cannot convert %qE (type %qT) to type %qT",
5370 arg, from_type, to_type);
5371 return 1;
5374 static int
5375 unify_no_common_base (bool explain_p, enum template_base_result r,
5376 tree parm, tree arg)
5378 if (explain_p)
5379 switch (r)
5381 case tbr_ambiguous_baseclass:
5382 inform (input_location, " %qT is an ambiguous base class of %qT",
5383 arg, parm);
5384 break;
5385 default:
5386 inform (input_location, " %qT is not derived from %qT", arg, parm);
5387 break;
5389 return 1;
5392 static int
5393 unify_inconsistent_template_template_parameters (bool explain_p)
5395 if (explain_p)
5396 inform (input_location,
5397 " template parameters of a template template argument are "
5398 "inconsistent with other deduced template arguments");
5399 return 1;
5402 static int
5403 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5405 if (explain_p)
5406 inform (input_location,
5407 " can't deduce a template for %qT from non-template type %qT",
5408 parm, arg);
5409 return 1;
5412 static int
5413 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5415 if (explain_p)
5416 inform (input_location,
5417 " template argument %qE does not match %qD", arg, parm);
5418 return 1;
5421 static int
5422 unify_overload_resolution_failure (bool explain_p, tree arg)
5424 if (explain_p)
5425 inform (input_location,
5426 " could not resolve address from overloaded function %qE",
5427 arg);
5428 return 1;
5431 /* Attempt to convert the non-type template parameter EXPR to the
5432 indicated TYPE. If the conversion is successful, return the
5433 converted value. If the conversion is unsuccessful, return
5434 NULL_TREE if we issued an error message, or error_mark_node if we
5435 did not. We issue error messages for out-and-out bad template
5436 parameters, but not simply because the conversion failed, since we
5437 might be just trying to do argument deduction. Both TYPE and EXPR
5438 must be non-dependent.
5440 The conversion follows the special rules described in
5441 [temp.arg.nontype], and it is much more strict than an implicit
5442 conversion.
5444 This function is called twice for each template argument (see
5445 lookup_template_class for a more accurate description of this
5446 problem). This means that we need to handle expressions which
5447 are not valid in a C++ source, but can be created from the
5448 first call (for instance, casts to perform conversions). These
5449 hacks can go away after we fix the double coercion problem. */
5451 static tree
5452 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5454 tree expr_type;
5456 /* Detect immediately string literals as invalid non-type argument.
5457 This special-case is not needed for correctness (we would easily
5458 catch this later), but only to provide better diagnostic for this
5459 common user mistake. As suggested by DR 100, we do not mention
5460 linkage issues in the diagnostic as this is not the point. */
5461 /* FIXME we're making this OK. */
5462 if (TREE_CODE (expr) == STRING_CST)
5464 if (complain & tf_error)
5465 error ("%qE is not a valid template argument for type %qT "
5466 "because string literals can never be used in this context",
5467 expr, type);
5468 return NULL_TREE;
5471 /* Add the ADDR_EXPR now for the benefit of
5472 value_dependent_expression_p. */
5473 if (TYPE_PTROBV_P (type)
5474 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5476 expr = decay_conversion (expr, complain);
5477 if (expr == error_mark_node)
5478 return error_mark_node;
5481 /* If we are in a template, EXPR may be non-dependent, but still
5482 have a syntactic, rather than semantic, form. For example, EXPR
5483 might be a SCOPE_REF, rather than the VAR_DECL to which the
5484 SCOPE_REF refers. Preserving the qualifying scope is necessary
5485 so that access checking can be performed when the template is
5486 instantiated -- but here we need the resolved form so that we can
5487 convert the argument. */
5488 if (TYPE_REF_OBJ_P (type)
5489 && has_value_dependent_address (expr))
5490 /* If we want the address and it's value-dependent, don't fold. */;
5491 else if (!type_unknown_p (expr))
5492 expr = fold_non_dependent_expr_sfinae (expr, complain);
5493 if (error_operand_p (expr))
5494 return error_mark_node;
5495 expr_type = TREE_TYPE (expr);
5496 if (TREE_CODE (type) == REFERENCE_TYPE)
5497 expr = mark_lvalue_use (expr);
5498 else
5499 expr = mark_rvalue_use (expr);
5501 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5502 to a non-type argument of "nullptr". */
5503 if (expr == nullptr_node && TYPE_PTR_OR_PTRMEM_P (type))
5504 expr = convert (type, expr);
5506 /* In C++11, integral or enumeration non-type template arguments can be
5507 arbitrary constant expressions. Pointer and pointer to
5508 member arguments can be general constant expressions that evaluate
5509 to a null value, but otherwise still need to be of a specific form. */
5510 if (cxx_dialect >= cxx0x)
5512 if (TREE_CODE (expr) == PTRMEM_CST)
5513 /* A PTRMEM_CST is already constant, and a valid template
5514 argument for a parameter of pointer to member type, we just want
5515 to leave it in that form rather than lower it to a
5516 CONSTRUCTOR. */;
5517 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5518 expr = maybe_constant_value (expr);
5519 else if (TYPE_PTR_OR_PTRMEM_P (type))
5521 tree folded = maybe_constant_value (expr);
5522 if (TYPE_PTR_P (type) ? integer_zerop (folded)
5523 : null_member_pointer_value_p (folded))
5524 expr = folded;
5528 /* HACK: Due to double coercion, we can get a
5529 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5530 which is the tree that we built on the first call (see
5531 below when coercing to reference to object or to reference to
5532 function). We just strip everything and get to the arg.
5533 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5534 for examples. */
5535 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5537 tree probe_type, probe = expr;
5538 if (REFERENCE_REF_P (probe))
5539 probe = TREE_OPERAND (probe, 0);
5540 probe_type = TREE_TYPE (probe);
5541 if (TREE_CODE (probe) == NOP_EXPR)
5543 /* ??? Maybe we could use convert_from_reference here, but we
5544 would need to relax its constraints because the NOP_EXPR
5545 could actually change the type to something more cv-qualified,
5546 and this is not folded by convert_from_reference. */
5547 tree addr = TREE_OPERAND (probe, 0);
5548 if (TREE_CODE (probe_type) == REFERENCE_TYPE
5549 && TREE_CODE (addr) == ADDR_EXPR
5550 && TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE
5551 && (same_type_ignoring_top_level_qualifiers_p
5552 (TREE_TYPE (probe_type),
5553 TREE_TYPE (TREE_TYPE (addr)))))
5555 expr = TREE_OPERAND (addr, 0);
5556 expr_type = TREE_TYPE (expr);
5561 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5562 parameter is a pointer to object, through decay and
5563 qualification conversion. Let's strip everything. */
5564 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5566 tree probe = expr;
5567 STRIP_NOPS (probe);
5568 if (TREE_CODE (probe) == ADDR_EXPR
5569 && TREE_CODE (TREE_TYPE (probe)) == POINTER_TYPE)
5571 /* Skip the ADDR_EXPR only if it is part of the decay for
5572 an array. Otherwise, it is part of the original argument
5573 in the source code. */
5574 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (probe, 0))) == ARRAY_TYPE)
5575 probe = TREE_OPERAND (probe, 0);
5576 expr = probe;
5577 expr_type = TREE_TYPE (expr);
5581 /* [temp.arg.nontype]/5, bullet 1
5583 For a non-type template-parameter of integral or enumeration type,
5584 integral promotions (_conv.prom_) and integral conversions
5585 (_conv.integral_) are applied. */
5586 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5588 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5589 t = maybe_constant_value (t);
5590 if (t != error_mark_node)
5591 expr = t;
5593 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5594 return error_mark_node;
5596 /* Notice that there are constant expressions like '4 % 0' which
5597 do not fold into integer constants. */
5598 if (TREE_CODE (expr) != INTEGER_CST)
5600 if (complain & tf_error)
5602 int errs = errorcount, warns = warningcount + werrorcount;
5603 if (processing_template_decl
5604 && !require_potential_constant_expression (expr))
5605 return NULL_TREE;
5606 expr = cxx_constant_value (expr);
5607 if (errorcount > errs || warningcount + werrorcount > warns)
5608 inform (EXPR_LOC_OR_HERE (expr),
5609 "in template argument for type %qT ", type);
5610 if (expr == error_mark_node)
5611 return NULL_TREE;
5612 /* else cxx_constant_value complained but gave us
5613 a real constant, so go ahead. */
5614 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5616 else
5617 return NULL_TREE;
5620 /* [temp.arg.nontype]/5, bullet 2
5622 For a non-type template-parameter of type pointer to object,
5623 qualification conversions (_conv.qual_) and the array-to-pointer
5624 conversion (_conv.array_) are applied. */
5625 else if (TYPE_PTROBV_P (type))
5627 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5629 A template-argument for a non-type, non-template template-parameter
5630 shall be one of: [...]
5632 -- the name of a non-type template-parameter;
5633 -- the address of an object or function with external linkage, [...]
5634 expressed as "& id-expression" where the & is optional if the name
5635 refers to a function or array, or if the corresponding
5636 template-parameter is a reference.
5638 Here, we do not care about functions, as they are invalid anyway
5639 for a parameter of type pointer-to-object. */
5641 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5642 /* Non-type template parameters are OK. */
5644 else if (cxx_dialect >= cxx0x && integer_zerop (expr))
5645 /* Null pointer values are OK in C++11. */;
5646 else if (TREE_CODE (expr) != ADDR_EXPR
5647 && TREE_CODE (expr_type) != ARRAY_TYPE)
5649 if (TREE_CODE (expr) == VAR_DECL)
5651 error ("%qD is not a valid template argument "
5652 "because %qD is a variable, not the address of "
5653 "a variable",
5654 expr, expr);
5655 return NULL_TREE;
5657 if (POINTER_TYPE_P (expr_type))
5659 error ("%qE is not a valid template argument for %qT"
5660 "because it is not the address of a variable",
5661 expr, type);
5662 return NULL_TREE;
5664 /* Other values, like integer constants, might be valid
5665 non-type arguments of some other type. */
5666 return error_mark_node;
5668 else
5670 tree decl;
5672 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5673 ? TREE_OPERAND (expr, 0) : expr);
5674 if (TREE_CODE (decl) != VAR_DECL)
5676 error ("%qE is not a valid template argument of type %qT "
5677 "because %qE is not a variable",
5678 expr, type, decl);
5679 return NULL_TREE;
5681 else if (cxx_dialect < cxx0x && !DECL_EXTERNAL_LINKAGE_P (decl))
5683 error ("%qE is not a valid template argument of type %qT "
5684 "because %qD does not have external linkage",
5685 expr, type, decl);
5686 return NULL_TREE;
5688 else if (cxx_dialect >= cxx0x && decl_linkage (decl) == lk_none)
5690 error ("%qE is not a valid template argument of type %qT "
5691 "because %qD has no linkage",
5692 expr, type, decl);
5693 return NULL_TREE;
5697 expr = decay_conversion (expr, complain);
5698 if (expr == error_mark_node)
5699 return error_mark_node;
5701 expr = perform_qualification_conversions (type, expr);
5702 if (expr == error_mark_node)
5703 return error_mark_node;
5705 /* [temp.arg.nontype]/5, bullet 3
5707 For a non-type template-parameter of type reference to object, no
5708 conversions apply. The type referred to by the reference may be more
5709 cv-qualified than the (otherwise identical) type of the
5710 template-argument. The template-parameter is bound directly to the
5711 template-argument, which must be an lvalue. */
5712 else if (TYPE_REF_OBJ_P (type))
5714 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5715 expr_type))
5716 return error_mark_node;
5718 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5720 error ("%qE is not a valid template argument for type %qT "
5721 "because of conflicts in cv-qualification", expr, type);
5722 return NULL_TREE;
5725 if (!real_lvalue_p (expr))
5727 error ("%qE is not a valid template argument for type %qT "
5728 "because it is not an lvalue", expr, type);
5729 return NULL_TREE;
5732 /* [temp.arg.nontype]/1
5734 A template-argument for a non-type, non-template template-parameter
5735 shall be one of: [...]
5737 -- the address of an object or function with external linkage. */
5738 if (TREE_CODE (expr) == INDIRECT_REF
5739 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5741 expr = TREE_OPERAND (expr, 0);
5742 if (DECL_P (expr))
5744 error ("%q#D is not a valid template argument for type %qT "
5745 "because a reference variable does not have a constant "
5746 "address", expr, type);
5747 return NULL_TREE;
5751 if (!DECL_P (expr))
5753 error ("%qE is not a valid template argument for type %qT "
5754 "because it is not an object with external linkage",
5755 expr, type);
5756 return NULL_TREE;
5759 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5761 error ("%qE is not a valid template argument for type %qT "
5762 "because object %qD has not external linkage",
5763 expr, type, expr);
5764 return NULL_TREE;
5767 expr = build_nop (type, build_address (expr));
5769 /* [temp.arg.nontype]/5, bullet 4
5771 For a non-type template-parameter of type pointer to function, only
5772 the function-to-pointer conversion (_conv.func_) is applied. If the
5773 template-argument represents a set of overloaded functions (or a
5774 pointer to such), the matching function is selected from the set
5775 (_over.over_). */
5776 else if (TYPE_PTRFN_P (type))
5778 /* If the argument is a template-id, we might not have enough
5779 context information to decay the pointer. */
5780 if (!type_unknown_p (expr_type))
5782 expr = decay_conversion (expr, complain);
5783 if (expr == error_mark_node)
5784 return error_mark_node;
5787 if (cxx_dialect >= cxx0x && integer_zerop (expr))
5788 /* Null pointer values are OK in C++11. */
5789 return perform_qualification_conversions (type, expr);
5791 expr = convert_nontype_argument_function (type, expr);
5792 if (!expr || expr == error_mark_node)
5793 return expr;
5795 /* [temp.arg.nontype]/5, bullet 5
5797 For a non-type template-parameter of type reference to function, no
5798 conversions apply. If the template-argument represents a set of
5799 overloaded functions, the matching function is selected from the set
5800 (_over.over_). */
5801 else if (TYPE_REFFN_P (type))
5803 if (TREE_CODE (expr) == ADDR_EXPR)
5805 error ("%qE is not a valid template argument for type %qT "
5806 "because it is a pointer", expr, type);
5807 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5808 return NULL_TREE;
5811 expr = convert_nontype_argument_function (type, expr);
5812 if (!expr || expr == error_mark_node)
5813 return expr;
5815 expr = build_nop (type, build_address (expr));
5817 /* [temp.arg.nontype]/5, bullet 6
5819 For a non-type template-parameter of type pointer to member function,
5820 no conversions apply. If the template-argument represents a set of
5821 overloaded member functions, the matching member function is selected
5822 from the set (_over.over_). */
5823 else if (TYPE_PTRMEMFUNC_P (type))
5825 expr = instantiate_type (type, expr, tf_none);
5826 if (expr == error_mark_node)
5827 return error_mark_node;
5829 /* [temp.arg.nontype] bullet 1 says the pointer to member
5830 expression must be a pointer-to-member constant. */
5831 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5832 return error_mark_node;
5834 /* There is no way to disable standard conversions in
5835 resolve_address_of_overloaded_function (called by
5836 instantiate_type). It is possible that the call succeeded by
5837 converting &B::I to &D::I (where B is a base of D), so we need
5838 to reject this conversion here.
5840 Actually, even if there was a way to disable standard conversions,
5841 it would still be better to reject them here so that we can
5842 provide a superior diagnostic. */
5843 if (!same_type_p (TREE_TYPE (expr), type))
5845 error ("%qE is not a valid template argument for type %qT "
5846 "because it is of type %qT", expr, type,
5847 TREE_TYPE (expr));
5848 /* If we are just one standard conversion off, explain. */
5849 if (can_convert (type, TREE_TYPE (expr), complain))
5850 inform (input_location,
5851 "standard conversions are not allowed in this context");
5852 return NULL_TREE;
5855 /* [temp.arg.nontype]/5, bullet 7
5857 For a non-type template-parameter of type pointer to data member,
5858 qualification conversions (_conv.qual_) are applied. */
5859 else if (TYPE_PTRDATAMEM_P (type))
5861 /* [temp.arg.nontype] bullet 1 says the pointer to member
5862 expression must be a pointer-to-member constant. */
5863 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5864 return error_mark_node;
5866 expr = perform_qualification_conversions (type, expr);
5867 if (expr == error_mark_node)
5868 return expr;
5870 else if (NULLPTR_TYPE_P (type))
5872 if (expr != nullptr_node)
5874 error ("%qE is not a valid template argument for type %qT "
5875 "because it is of type %qT", expr, type, TREE_TYPE (expr));
5876 return NULL_TREE;
5878 return expr;
5880 /* A template non-type parameter must be one of the above. */
5881 else
5882 gcc_unreachable ();
5884 /* Sanity check: did we actually convert the argument to the
5885 right type? */
5886 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5887 (type, TREE_TYPE (expr)));
5888 return expr;
5891 /* Subroutine of coerce_template_template_parms, which returns 1 if
5892 PARM_PARM and ARG_PARM match using the rule for the template
5893 parameters of template template parameters. Both PARM and ARG are
5894 template parameters; the rest of the arguments are the same as for
5895 coerce_template_template_parms.
5897 static int
5898 coerce_template_template_parm (tree parm,
5899 tree arg,
5900 tsubst_flags_t complain,
5901 tree in_decl,
5902 tree outer_args)
5904 if (arg == NULL_TREE || arg == error_mark_node
5905 || parm == NULL_TREE || parm == error_mark_node)
5906 return 0;
5908 if (TREE_CODE (arg) != TREE_CODE (parm))
5909 return 0;
5911 switch (TREE_CODE (parm))
5913 case TEMPLATE_DECL:
5914 /* We encounter instantiations of templates like
5915 template <template <template <class> class> class TT>
5916 class C; */
5918 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5919 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5921 if (!coerce_template_template_parms
5922 (parmparm, argparm, complain, in_decl, outer_args))
5923 return 0;
5925 /* Fall through. */
5927 case TYPE_DECL:
5928 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5929 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5930 /* Argument is a parameter pack but parameter is not. */
5931 return 0;
5932 break;
5934 case PARM_DECL:
5935 /* The tsubst call is used to handle cases such as
5937 template <int> class C {};
5938 template <class T, template <T> class TT> class D {};
5939 D<int, C> d;
5941 i.e. the parameter list of TT depends on earlier parameters. */
5942 if (!uses_template_parms (TREE_TYPE (arg))
5943 && !same_type_p
5944 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5945 TREE_TYPE (arg)))
5946 return 0;
5948 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5949 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5950 /* Argument is a parameter pack but parameter is not. */
5951 return 0;
5953 break;
5955 default:
5956 gcc_unreachable ();
5959 return 1;
5963 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5964 template template parameters. Both PARM_PARMS and ARG_PARMS are
5965 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5966 or PARM_DECL.
5968 Consider the example:
5969 template <class T> class A;
5970 template<template <class U> class TT> class B;
5972 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5973 the parameters to A, and OUTER_ARGS contains A. */
5975 static int
5976 coerce_template_template_parms (tree parm_parms,
5977 tree arg_parms,
5978 tsubst_flags_t complain,
5979 tree in_decl,
5980 tree outer_args)
5982 int nparms, nargs, i;
5983 tree parm, arg;
5984 int variadic_p = 0;
5986 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5987 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5989 nparms = TREE_VEC_LENGTH (parm_parms);
5990 nargs = TREE_VEC_LENGTH (arg_parms);
5992 /* Determine whether we have a parameter pack at the end of the
5993 template template parameter's template parameter list. */
5994 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5996 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5998 if (parm == error_mark_node)
5999 return 0;
6001 switch (TREE_CODE (parm))
6003 case TEMPLATE_DECL:
6004 case TYPE_DECL:
6005 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6006 variadic_p = 1;
6007 break;
6009 case PARM_DECL:
6010 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6011 variadic_p = 1;
6012 break;
6014 default:
6015 gcc_unreachable ();
6019 if (nargs != nparms
6020 && !(variadic_p && nargs >= nparms - 1))
6021 return 0;
6023 /* Check all of the template parameters except the parameter pack at
6024 the end (if any). */
6025 for (i = 0; i < nparms - variadic_p; ++i)
6027 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6028 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6029 continue;
6031 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6032 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6034 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6035 outer_args))
6036 return 0;
6040 if (variadic_p)
6042 /* Check each of the template parameters in the template
6043 argument against the template parameter pack at the end of
6044 the template template parameter. */
6045 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6046 return 0;
6048 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6050 for (; i < nargs; ++i)
6052 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6053 continue;
6055 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6057 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6058 outer_args))
6059 return 0;
6063 return 1;
6066 /* Verifies that the deduced template arguments (in TARGS) for the
6067 template template parameters (in TPARMS) represent valid bindings,
6068 by comparing the template parameter list of each template argument
6069 to the template parameter list of its corresponding template
6070 template parameter, in accordance with DR150. This
6071 routine can only be called after all template arguments have been
6072 deduced. It will return TRUE if all of the template template
6073 parameter bindings are okay, FALSE otherwise. */
6074 bool
6075 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6077 int i, ntparms = TREE_VEC_LENGTH (tparms);
6078 bool ret = true;
6080 /* We're dealing with template parms in this process. */
6081 ++processing_template_decl;
6083 targs = INNERMOST_TEMPLATE_ARGS (targs);
6085 for (i = 0; i < ntparms; ++i)
6087 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6088 tree targ = TREE_VEC_ELT (targs, i);
6090 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6092 tree packed_args = NULL_TREE;
6093 int idx, len = 1;
6095 if (ARGUMENT_PACK_P (targ))
6097 /* Look inside the argument pack. */
6098 packed_args = ARGUMENT_PACK_ARGS (targ);
6099 len = TREE_VEC_LENGTH (packed_args);
6102 for (idx = 0; idx < len; ++idx)
6104 tree targ_parms = NULL_TREE;
6106 if (packed_args)
6107 /* Extract the next argument from the argument
6108 pack. */
6109 targ = TREE_VEC_ELT (packed_args, idx);
6111 if (PACK_EXPANSION_P (targ))
6112 /* Look at the pattern of the pack expansion. */
6113 targ = PACK_EXPANSION_PATTERN (targ);
6115 /* Extract the template parameters from the template
6116 argument. */
6117 if (TREE_CODE (targ) == TEMPLATE_DECL)
6118 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6119 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6120 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6122 /* Verify that we can coerce the template template
6123 parameters from the template argument to the template
6124 parameter. This requires an exact match. */
6125 if (targ_parms
6126 && !coerce_template_template_parms
6127 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6128 targ_parms,
6129 tf_none,
6130 tparm,
6131 targs))
6133 ret = false;
6134 goto out;
6140 out:
6142 --processing_template_decl;
6143 return ret;
6146 /* Since type attributes aren't mangled, we need to strip them from
6147 template type arguments. */
6149 static tree
6150 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6152 tree mv;
6153 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6154 return arg;
6155 mv = TYPE_MAIN_VARIANT (arg);
6156 arg = strip_typedefs (arg);
6157 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6158 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6160 if (complain & tf_warning)
6161 warning (0, "ignoring attributes on template argument %qT", arg);
6162 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6163 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6165 return arg;
6168 /* Convert the indicated template ARG as necessary to match the
6169 indicated template PARM. Returns the converted ARG, or
6170 error_mark_node if the conversion was unsuccessful. Error and
6171 warning messages are issued under control of COMPLAIN. This
6172 conversion is for the Ith parameter in the parameter list. ARGS is
6173 the full set of template arguments deduced so far. */
6175 static tree
6176 convert_template_argument (tree parm,
6177 tree arg,
6178 tree args,
6179 tsubst_flags_t complain,
6180 int i,
6181 tree in_decl)
6183 tree orig_arg;
6184 tree val;
6185 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6187 if (TREE_CODE (arg) == TREE_LIST
6188 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6190 /* The template argument was the name of some
6191 member function. That's usually
6192 invalid, but static members are OK. In any
6193 case, grab the underlying fields/functions
6194 and issue an error later if required. */
6195 orig_arg = TREE_VALUE (arg);
6196 TREE_TYPE (arg) = unknown_type_node;
6199 orig_arg = arg;
6201 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6202 requires_type = (TREE_CODE (parm) == TYPE_DECL
6203 || requires_tmpl_type);
6205 /* When determining whether an argument pack expansion is a template,
6206 look at the pattern. */
6207 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6208 arg = PACK_EXPANSION_PATTERN (arg);
6210 /* Deal with an injected-class-name used as a template template arg. */
6211 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6213 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6214 if (TREE_CODE (t) == TEMPLATE_DECL)
6216 if (cxx_dialect >= cxx0x)
6217 /* OK under DR 1004. */;
6218 else if (complain & tf_warning_or_error)
6219 pedwarn (input_location, OPT_Wpedantic, "injected-class-name %qD"
6220 " used as template template argument", TYPE_NAME (arg));
6221 else if (flag_pedantic_errors)
6222 t = arg;
6224 arg = t;
6228 is_tmpl_type =
6229 ((TREE_CODE (arg) == TEMPLATE_DECL
6230 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6231 || (requires_tmpl_type && TREE_CODE (arg) == TYPE_ARGUMENT_PACK)
6232 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6233 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6235 if (is_tmpl_type
6236 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6237 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6238 arg = TYPE_STUB_DECL (arg);
6240 is_type = TYPE_P (arg) || is_tmpl_type;
6242 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6243 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6245 if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR)
6247 if (complain & tf_error)
6248 error ("invalid use of destructor %qE as a type", orig_arg);
6249 return error_mark_node;
6252 permerror (input_location,
6253 "to refer to a type member of a template parameter, "
6254 "use %<typename %E%>", orig_arg);
6256 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6257 TREE_OPERAND (arg, 1),
6258 typename_type,
6259 complain);
6260 arg = orig_arg;
6261 is_type = 1;
6263 if (is_type != requires_type)
6265 if (in_decl)
6267 if (complain & tf_error)
6269 error ("type/value mismatch at argument %d in template "
6270 "parameter list for %qD",
6271 i + 1, in_decl);
6272 if (is_type)
6273 error (" expected a constant of type %qT, got %qT",
6274 TREE_TYPE (parm),
6275 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6276 else if (requires_tmpl_type)
6277 error (" expected a class template, got %qE", orig_arg);
6278 else
6279 error (" expected a type, got %qE", orig_arg);
6282 return error_mark_node;
6284 if (is_tmpl_type ^ requires_tmpl_type)
6286 if (in_decl && (complain & tf_error))
6288 error ("type/value mismatch at argument %d in template "
6289 "parameter list for %qD",
6290 i + 1, in_decl);
6291 if (is_tmpl_type)
6292 error (" expected a type, got %qT", DECL_NAME (arg));
6293 else
6294 error (" expected a class template, got %qT", orig_arg);
6296 return error_mark_node;
6299 if (is_type)
6301 if (requires_tmpl_type)
6303 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6304 val = orig_arg;
6305 else if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6306 /* The number of argument required is not known yet.
6307 Just accept it for now. */
6308 val = TREE_TYPE (arg);
6309 else
6311 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6312 tree argparm;
6314 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6316 if (coerce_template_template_parms (parmparm, argparm,
6317 complain, in_decl,
6318 args))
6320 val = arg;
6322 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6323 TEMPLATE_DECL. */
6324 if (val != error_mark_node)
6326 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6327 val = TREE_TYPE (val);
6328 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6329 val = make_pack_expansion (val);
6332 else
6334 if (in_decl && (complain & tf_error))
6336 error ("type/value mismatch at argument %d in "
6337 "template parameter list for %qD",
6338 i + 1, in_decl);
6339 error (" expected a template of type %qD, got %qT",
6340 parm, orig_arg);
6343 val = error_mark_node;
6347 else
6348 val = orig_arg;
6349 /* We only form one instance of each template specialization.
6350 Therefore, if we use a non-canonical variant (i.e., a
6351 typedef), any future messages referring to the type will use
6352 the typedef, which is confusing if those future uses do not
6353 themselves also use the typedef. */
6354 if (TYPE_P (val))
6355 val = canonicalize_type_argument (val, complain);
6357 else
6359 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6361 if (invalid_nontype_parm_type_p (t, complain))
6362 return error_mark_node;
6364 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6366 if (same_type_p (t, TREE_TYPE (orig_arg)))
6367 val = orig_arg;
6368 else
6370 /* Not sure if this is reachable, but it doesn't hurt
6371 to be robust. */
6372 error ("type mismatch in nontype parameter pack");
6373 val = error_mark_node;
6376 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6377 /* We used to call digest_init here. However, digest_init
6378 will report errors, which we don't want when complain
6379 is zero. More importantly, digest_init will try too
6380 hard to convert things: for example, `0' should not be
6381 converted to pointer type at this point according to
6382 the standard. Accepting this is not merely an
6383 extension, since deciding whether or not these
6384 conversions can occur is part of determining which
6385 function template to call, or whether a given explicit
6386 argument specification is valid. */
6387 val = convert_nontype_argument (t, orig_arg, complain);
6388 else
6389 val = strip_typedefs_expr (orig_arg);
6391 if (val == NULL_TREE)
6392 val = error_mark_node;
6393 else if (val == error_mark_node && (complain & tf_error))
6394 error ("could not convert template argument %qE to %qT", orig_arg, t);
6396 if (TREE_CODE (val) == SCOPE_REF)
6398 /* Strip typedefs from the SCOPE_REF. */
6399 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6400 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6401 complain);
6402 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6403 QUALIFIED_NAME_IS_TEMPLATE (val));
6407 return val;
6410 /* Coerces the remaining template arguments in INNER_ARGS (from
6411 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6412 Returns the coerced argument pack. PARM_IDX is the position of this
6413 parameter in the template parameter list. ARGS is the original
6414 template argument list. */
6415 static tree
6416 coerce_template_parameter_pack (tree parms,
6417 int parm_idx,
6418 tree args,
6419 tree inner_args,
6420 int arg_idx,
6421 tree new_args,
6422 int* lost,
6423 tree in_decl,
6424 tsubst_flags_t complain)
6426 tree parm = TREE_VEC_ELT (parms, parm_idx);
6427 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6428 tree packed_args;
6429 tree argument_pack;
6430 tree packed_types = NULL_TREE;
6432 if (arg_idx > nargs)
6433 arg_idx = nargs;
6435 packed_args = make_tree_vec (nargs - arg_idx);
6437 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6438 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6440 /* When the template parameter is a non-type template
6441 parameter pack whose type uses parameter packs, we need
6442 to look at each of the template arguments
6443 separately. Build a vector of the types for these
6444 non-type template parameters in PACKED_TYPES. */
6445 tree expansion
6446 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6447 packed_types = tsubst_pack_expansion (expansion, args,
6448 complain, in_decl);
6450 if (packed_types == error_mark_node)
6451 return error_mark_node;
6453 /* Check that we have the right number of arguments. */
6454 if (arg_idx < nargs
6455 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6456 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6458 int needed_parms
6459 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6460 error ("wrong number of template arguments (%d, should be %d)",
6461 nargs, needed_parms);
6462 return error_mark_node;
6465 /* If we aren't able to check the actual arguments now
6466 (because they haven't been expanded yet), we can at least
6467 verify that all of the types used for the non-type
6468 template parameter pack are, in fact, valid for non-type
6469 template parameters. */
6470 if (arg_idx < nargs
6471 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6473 int j, len = TREE_VEC_LENGTH (packed_types);
6474 for (j = 0; j < len; ++j)
6476 tree t = TREE_VEC_ELT (packed_types, j);
6477 if (invalid_nontype_parm_type_p (t, complain))
6478 return error_mark_node;
6483 /* Convert the remaining arguments, which will be a part of the
6484 parameter pack "parm". */
6485 for (; arg_idx < nargs; ++arg_idx)
6487 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6488 tree actual_parm = TREE_VALUE (parm);
6490 if (packed_types && !PACK_EXPANSION_P (arg))
6492 /* When we have a vector of types (corresponding to the
6493 non-type template parameter pack that uses parameter
6494 packs in its type, as mention above), and the
6495 argument is not an expansion (which expands to a
6496 currently unknown number of arguments), clone the
6497 parm and give it the next type in PACKED_TYPES. */
6498 actual_parm = copy_node (actual_parm);
6499 TREE_TYPE (actual_parm) =
6500 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6503 if (arg == error_mark_node)
6505 if (complain & tf_error)
6506 error ("template argument %d is invalid", arg_idx + 1);
6508 else
6509 arg = convert_template_argument (actual_parm,
6510 arg, new_args, complain, parm_idx,
6511 in_decl);
6512 if (arg == error_mark_node)
6513 (*lost)++;
6514 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6517 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6518 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6519 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6520 else
6522 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6523 TREE_TYPE (argument_pack)
6524 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6525 TREE_CONSTANT (argument_pack) = 1;
6528 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6529 #ifdef ENABLE_CHECKING
6530 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6531 TREE_VEC_LENGTH (packed_args));
6532 #endif
6533 return argument_pack;
6536 /* Returns true if the template argument vector ARGS contains
6537 any pack expansions, false otherwise. */
6539 static bool
6540 any_pack_expanson_args_p (tree args)
6542 int i;
6543 if (args)
6544 for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
6545 if (PACK_EXPANSION_P (TREE_VEC_ELT (args, i)))
6546 return true;
6547 return false;
6550 /* Convert all template arguments to their appropriate types, and
6551 return a vector containing the innermost resulting template
6552 arguments. If any error occurs, return error_mark_node. Error and
6553 warning messages are issued under control of COMPLAIN.
6555 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6556 for arguments not specified in ARGS. Otherwise, if
6557 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6558 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6559 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6560 ARGS. */
6562 static tree
6563 coerce_template_parms (tree parms,
6564 tree args,
6565 tree in_decl,
6566 tsubst_flags_t complain,
6567 bool require_all_args,
6568 bool use_default_args)
6570 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6571 tree inner_args;
6572 tree new_args;
6573 tree new_inner_args;
6574 int saved_unevaluated_operand;
6575 int saved_inhibit_evaluation_warnings;
6577 /* When used as a boolean value, indicates whether this is a
6578 variadic template parameter list. Since it's an int, we can also
6579 subtract it from nparms to get the number of non-variadic
6580 parameters. */
6581 int variadic_p = 0;
6582 int post_variadic_parms = 0;
6584 if (args == error_mark_node)
6585 return error_mark_node;
6587 nparms = TREE_VEC_LENGTH (parms);
6589 /* Determine if there are any parameter packs. */
6590 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6592 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6593 if (variadic_p)
6594 ++post_variadic_parms;
6595 if (template_parameter_pack_p (tparm))
6596 ++variadic_p;
6599 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6600 /* If there are no parameters that follow a parameter pack, we need to
6601 expand any argument packs so that we can deduce a parameter pack from
6602 some non-packed args followed by an argument pack, as in variadic85.C.
6603 If there are such parameters, we need to leave argument packs intact
6604 so the arguments are assigned properly. This can happen when dealing
6605 with a nested class inside a partial specialization of a class
6606 template, as in variadic92.C, or when deducing a template parameter pack
6607 from a sub-declarator, as in variadic114.C. */
6608 if (!post_variadic_parms)
6609 inner_args = expand_template_argument_pack (inner_args);
6611 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6612 if ((nargs > nparms && !variadic_p)
6613 || (nargs < nparms - variadic_p
6614 && require_all_args
6615 && !any_pack_expanson_args_p (inner_args)
6616 && (!use_default_args
6617 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6618 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6620 if (complain & tf_error)
6622 if (variadic_p)
6624 nparms -= variadic_p;
6625 error ("wrong number of template arguments "
6626 "(%d, should be %d or more)", nargs, nparms);
6628 else
6629 error ("wrong number of template arguments "
6630 "(%d, should be %d)", nargs, nparms);
6632 if (in_decl)
6633 error ("provided for %q+D", in_decl);
6636 return error_mark_node;
6639 /* We need to evaluate the template arguments, even though this
6640 template-id may be nested within a "sizeof". */
6641 saved_unevaluated_operand = cp_unevaluated_operand;
6642 cp_unevaluated_operand = 0;
6643 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6644 c_inhibit_evaluation_warnings = 0;
6645 new_inner_args = make_tree_vec (nparms);
6646 new_args = add_outermost_template_args (args, new_inner_args);
6647 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6649 tree arg;
6650 tree parm;
6652 /* Get the Ith template parameter. */
6653 parm = TREE_VEC_ELT (parms, parm_idx);
6655 if (parm == error_mark_node)
6657 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6658 continue;
6661 /* Calculate the next argument. */
6662 if (arg_idx < nargs)
6663 arg = TREE_VEC_ELT (inner_args, arg_idx);
6664 else
6665 arg = NULL_TREE;
6667 if (template_parameter_pack_p (TREE_VALUE (parm))
6668 && !(arg && ARGUMENT_PACK_P (arg)))
6670 /* All remaining arguments will be placed in the
6671 template parameter pack PARM. */
6672 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6673 inner_args, arg_idx,
6674 new_args, &lost,
6675 in_decl, complain);
6677 /* Store this argument. */
6678 if (arg == error_mark_node)
6679 lost++;
6680 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6682 /* We are done with all of the arguments. */
6683 arg_idx = nargs;
6685 continue;
6687 else if (arg)
6689 if (PACK_EXPANSION_P (arg))
6691 /* We don't know how many args we have yet, just
6692 use the unconverted ones for now. */
6693 new_inner_args = inner_args;
6694 break;
6697 else if (require_all_args)
6699 /* There must be a default arg in this case. */
6700 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6701 complain, in_decl);
6702 /* The position of the first default template argument,
6703 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6704 Record that. */
6705 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6706 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6708 else
6709 break;
6711 if (arg == error_mark_node)
6713 if (complain & tf_error)
6714 error ("template argument %d is invalid", arg_idx + 1);
6716 else if (!arg)
6717 /* This only occurs if there was an error in the template
6718 parameter list itself (which we would already have
6719 reported) that we are trying to recover from, e.g., a class
6720 template with a parameter list such as
6721 template<typename..., typename>. */
6722 ++lost;
6723 else
6724 arg = convert_template_argument (TREE_VALUE (parm),
6725 arg, new_args, complain,
6726 parm_idx, in_decl);
6728 if (arg == error_mark_node)
6729 lost++;
6730 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6732 cp_unevaluated_operand = saved_unevaluated_operand;
6733 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6735 if (lost)
6736 return error_mark_node;
6738 #ifdef ENABLE_CHECKING
6739 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6740 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6741 TREE_VEC_LENGTH (new_inner_args));
6742 #endif
6744 return new_inner_args;
6747 /* Like coerce_template_parms. If PARMS represents all template
6748 parameters levels, this function returns a vector of vectors
6749 representing all the resulting argument levels. Note that in this
6750 case, only the innermost arguments are coerced because the
6751 outermost ones are supposed to have been coerced already.
6753 Otherwise, if PARMS represents only (the innermost) vector of
6754 parameters, this function returns a vector containing just the
6755 innermost resulting arguments. */
6757 static tree
6758 coerce_innermost_template_parms (tree parms,
6759 tree args,
6760 tree in_decl,
6761 tsubst_flags_t complain,
6762 bool require_all_args,
6763 bool use_default_args)
6765 int parms_depth = TMPL_PARMS_DEPTH (parms);
6766 int args_depth = TMPL_ARGS_DEPTH (args);
6767 tree coerced_args;
6769 if (parms_depth > 1)
6771 coerced_args = make_tree_vec (parms_depth);
6772 tree level;
6773 int cur_depth;
6775 for (level = parms, cur_depth = parms_depth;
6776 parms_depth > 0 && level != NULL_TREE;
6777 level = TREE_CHAIN (level), --cur_depth)
6779 tree l;
6780 if (cur_depth == args_depth)
6781 l = coerce_template_parms (TREE_VALUE (level),
6782 args, in_decl, complain,
6783 require_all_args,
6784 use_default_args);
6785 else
6786 l = TMPL_ARGS_LEVEL (args, cur_depth);
6788 if (l == error_mark_node)
6789 return error_mark_node;
6791 SET_TMPL_ARGS_LEVEL (coerced_args, cur_depth, l);
6794 else
6795 coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms),
6796 args, in_decl, complain,
6797 require_all_args,
6798 use_default_args);
6799 return coerced_args;
6802 /* Returns 1 if template args OT and NT are equivalent. */
6804 static int
6805 template_args_equal (tree ot, tree nt)
6807 if (nt == ot)
6808 return 1;
6809 if (nt == NULL_TREE || ot == NULL_TREE)
6810 return false;
6812 if (TREE_CODE (nt) == TREE_VEC)
6813 /* For member templates */
6814 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6815 else if (PACK_EXPANSION_P (ot))
6816 return (PACK_EXPANSION_P (nt)
6817 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6818 PACK_EXPANSION_PATTERN (nt))
6819 && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot),
6820 PACK_EXPANSION_EXTRA_ARGS (nt)));
6821 else if (ARGUMENT_PACK_P (ot))
6823 int i, len;
6824 tree opack, npack;
6826 if (!ARGUMENT_PACK_P (nt))
6827 return 0;
6829 opack = ARGUMENT_PACK_ARGS (ot);
6830 npack = ARGUMENT_PACK_ARGS (nt);
6831 len = TREE_VEC_LENGTH (opack);
6832 if (TREE_VEC_LENGTH (npack) != len)
6833 return 0;
6834 for (i = 0; i < len; ++i)
6835 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6836 TREE_VEC_ELT (npack, i)))
6837 return 0;
6838 return 1;
6840 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6842 /* We get here probably because we are in the middle of substituting
6843 into the pattern of a pack expansion. In that case the
6844 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6845 interested in. So we want to use the initial pack argument for
6846 the comparison. */
6847 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6848 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6849 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6850 return template_args_equal (ot, nt);
6852 else if (TYPE_P (nt))
6853 return TYPE_P (ot) && same_type_p (ot, nt);
6854 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6855 return 0;
6856 else
6857 return cp_tree_equal (ot, nt);
6860 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6861 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6862 NEWARG_PTR with the offending arguments if they are non-NULL. */
6864 static int
6865 comp_template_args_with_info (tree oldargs, tree newargs,
6866 tree *oldarg_ptr, tree *newarg_ptr)
6868 int i;
6870 if (oldargs == newargs)
6871 return 1;
6873 if (!oldargs || !newargs)
6874 return 0;
6876 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6877 return 0;
6879 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6881 tree nt = TREE_VEC_ELT (newargs, i);
6882 tree ot = TREE_VEC_ELT (oldargs, i);
6884 if (! template_args_equal (ot, nt))
6886 if (oldarg_ptr != NULL)
6887 *oldarg_ptr = ot;
6888 if (newarg_ptr != NULL)
6889 *newarg_ptr = nt;
6890 return 0;
6893 return 1;
6896 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6897 of template arguments. Returns 0 otherwise. */
6900 comp_template_args (tree oldargs, tree newargs)
6902 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
6905 static void
6906 add_pending_template (tree d)
6908 tree ti = (TYPE_P (d)
6909 ? CLASSTYPE_TEMPLATE_INFO (d)
6910 : DECL_TEMPLATE_INFO (d));
6911 struct pending_template *pt;
6912 int level;
6914 if (TI_PENDING_TEMPLATE_FLAG (ti))
6915 return;
6917 /* We are called both from instantiate_decl, where we've already had a
6918 tinst_level pushed, and instantiate_template, where we haven't.
6919 Compensate. */
6920 level = !current_tinst_level || current_tinst_level->decl != d;
6922 if (level)
6923 push_tinst_level (d);
6925 pt = ggc_alloc_pending_template ();
6926 pt->next = NULL;
6927 pt->tinst = current_tinst_level;
6928 if (last_pending_template)
6929 last_pending_template->next = pt;
6930 else
6931 pending_templates = pt;
6933 last_pending_template = pt;
6935 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6937 if (level)
6938 pop_tinst_level ();
6942 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6943 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6944 documentation for TEMPLATE_ID_EXPR. */
6946 tree
6947 lookup_template_function (tree fns, tree arglist)
6949 tree type;
6951 if (fns == error_mark_node || arglist == error_mark_node)
6952 return error_mark_node;
6954 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6956 if (!is_overloaded_fn (fns) && !identifier_p (fns))
6958 error ("%q#D is not a function template", fns);
6959 return error_mark_node;
6962 if (BASELINK_P (fns))
6964 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6965 unknown_type_node,
6966 BASELINK_FUNCTIONS (fns),
6967 arglist);
6968 return fns;
6971 type = TREE_TYPE (fns);
6972 if (TREE_CODE (fns) == OVERLOAD || !type)
6973 type = unknown_type_node;
6975 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6978 /* Within the scope of a template class S<T>, the name S gets bound
6979 (in build_self_reference) to a TYPE_DECL for the class, not a
6980 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6981 or one of its enclosing classes, and that type is a template,
6982 return the associated TEMPLATE_DECL. Otherwise, the original
6983 DECL is returned.
6985 Also handle the case when DECL is a TREE_LIST of ambiguous
6986 injected-class-names from different bases. */
6988 tree
6989 maybe_get_template_decl_from_type_decl (tree decl)
6991 if (decl == NULL_TREE)
6992 return decl;
6994 /* DR 176: A lookup that finds an injected-class-name (10.2
6995 [class.member.lookup]) can result in an ambiguity in certain cases
6996 (for example, if it is found in more than one base class). If all of
6997 the injected-class-names that are found refer to specializations of
6998 the same class template, and if the name is followed by a
6999 template-argument-list, the reference refers to the class template
7000 itself and not a specialization thereof, and is not ambiguous. */
7001 if (TREE_CODE (decl) == TREE_LIST)
7003 tree t, tmpl = NULL_TREE;
7004 for (t = decl; t; t = TREE_CHAIN (t))
7006 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
7007 if (!tmpl)
7008 tmpl = elt;
7009 else if (tmpl != elt)
7010 break;
7012 if (tmpl && t == NULL_TREE)
7013 return tmpl;
7014 else
7015 return decl;
7018 return (decl != NULL_TREE
7019 && DECL_SELF_REFERENCE_P (decl)
7020 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
7021 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
7024 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7025 parameters, find the desired type.
7027 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7029 IN_DECL, if non-NULL, is the template declaration we are trying to
7030 instantiate.
7032 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7033 the class we are looking up.
7035 Issue error and warning messages under control of COMPLAIN.
7037 If the template class is really a local class in a template
7038 function, then the FUNCTION_CONTEXT is the function in which it is
7039 being instantiated.
7041 ??? Note that this function is currently called *twice* for each
7042 template-id: the first time from the parser, while creating the
7043 incomplete type (finish_template_type), and the second type during the
7044 real instantiation (instantiate_template_class). This is surely something
7045 that we want to avoid. It also causes some problems with argument
7046 coercion (see convert_nontype_argument for more information on this). */
7048 static tree
7049 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
7050 int entering_scope, tsubst_flags_t complain)
7052 tree templ = NULL_TREE, parmlist;
7053 tree t;
7054 void **slot;
7055 spec_entry *entry;
7056 spec_entry elt;
7057 hashval_t hash;
7059 if (identifier_p (d1))
7061 tree value = innermost_non_namespace_value (d1);
7062 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
7063 templ = value;
7064 else
7066 if (context)
7067 push_decl_namespace (context);
7068 templ = lookup_name (d1);
7069 templ = maybe_get_template_decl_from_type_decl (templ);
7070 if (context)
7071 pop_decl_namespace ();
7073 if (templ)
7074 context = DECL_CONTEXT (templ);
7076 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
7078 tree type = TREE_TYPE (d1);
7080 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7081 an implicit typename for the second A. Deal with it. */
7082 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
7083 type = TREE_TYPE (type);
7085 if (CLASSTYPE_TEMPLATE_INFO (type))
7087 templ = CLASSTYPE_TI_TEMPLATE (type);
7088 d1 = DECL_NAME (templ);
7091 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7092 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7094 templ = TYPE_TI_TEMPLATE (d1);
7095 d1 = DECL_NAME (templ);
7097 else if (TREE_CODE (d1) == TEMPLATE_DECL
7098 && DECL_TEMPLATE_RESULT (d1)
7099 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7101 templ = d1;
7102 d1 = DECL_NAME (templ);
7103 context = DECL_CONTEXT (templ);
7106 /* Issue an error message if we didn't find a template. */
7107 if (! templ)
7109 if (complain & tf_error)
7110 error ("%qT is not a template", d1);
7111 return error_mark_node;
7114 if (TREE_CODE (templ) != TEMPLATE_DECL
7115 /* Make sure it's a user visible template, if it was named by
7116 the user. */
7117 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7118 && !PRIMARY_TEMPLATE_P (templ)))
7120 if (complain & tf_error)
7122 error ("non-template type %qT used as a template", d1);
7123 if (in_decl)
7124 error ("for template declaration %q+D", in_decl);
7126 return error_mark_node;
7129 complain &= ~tf_user;
7131 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7133 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7134 template arguments */
7136 tree parm;
7137 tree arglist2;
7138 tree outer;
7140 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7142 /* Consider an example where a template template parameter declared as
7144 template <class T, class U = std::allocator<T> > class TT
7146 The template parameter level of T and U are one level larger than
7147 of TT. To proper process the default argument of U, say when an
7148 instantiation `TT<int>' is seen, we need to build the full
7149 arguments containing {int} as the innermost level. Outer levels,
7150 available when not appearing as default template argument, can be
7151 obtained from the arguments of the enclosing template.
7153 Suppose that TT is later substituted with std::vector. The above
7154 instantiation is `TT<int, std::allocator<T> >' with TT at
7155 level 1, and T at level 2, while the template arguments at level 1
7156 becomes {std::vector} and the inner level 2 is {int}. */
7158 outer = DECL_CONTEXT (templ);
7159 if (outer)
7160 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7161 else if (current_template_parms)
7162 /* This is an argument of the current template, so we haven't set
7163 DECL_CONTEXT yet. */
7164 outer = current_template_args ();
7166 if (outer)
7167 arglist = add_to_template_args (outer, arglist);
7169 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7170 complain,
7171 /*require_all_args=*/true,
7172 /*use_default_args=*/true);
7173 if (arglist2 == error_mark_node
7174 || (!uses_template_parms (arglist2)
7175 && check_instantiated_args (templ, arglist2, complain)))
7176 return error_mark_node;
7178 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7179 return parm;
7181 else
7183 tree template_type = TREE_TYPE (templ);
7184 tree gen_tmpl;
7185 tree type_decl;
7186 tree found = NULL_TREE;
7187 int arg_depth;
7188 int parm_depth;
7189 int is_dependent_type;
7190 int use_partial_inst_tmpl = false;
7192 if (template_type == error_mark_node)
7193 /* An error occured while building the template TEMPL, and a
7194 diagnostic has most certainly been emitted for that
7195 already. Let's propagate that error. */
7196 return error_mark_node;
7198 gen_tmpl = most_general_template (templ);
7199 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7200 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7201 arg_depth = TMPL_ARGS_DEPTH (arglist);
7203 if (arg_depth == 1 && parm_depth > 1)
7205 /* We've been given an incomplete set of template arguments.
7206 For example, given:
7208 template <class T> struct S1 {
7209 template <class U> struct S2 {};
7210 template <class U> struct S2<U*> {};
7213 we will be called with an ARGLIST of `U*', but the
7214 TEMPLATE will be `template <class T> template
7215 <class U> struct S1<T>::S2'. We must fill in the missing
7216 arguments. */
7217 arglist
7218 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7219 arglist);
7220 arg_depth = TMPL_ARGS_DEPTH (arglist);
7223 /* Now we should have enough arguments. */
7224 gcc_assert (parm_depth == arg_depth);
7226 /* From here on, we're only interested in the most general
7227 template. */
7229 /* Calculate the BOUND_ARGS. These will be the args that are
7230 actually tsubst'd into the definition to create the
7231 instantiation. */
7232 if (parm_depth > 1)
7234 /* We have multiple levels of arguments to coerce, at once. */
7235 int i;
7236 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7238 tree bound_args = make_tree_vec (parm_depth);
7240 for (i = saved_depth,
7241 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7242 i > 0 && t != NULL_TREE;
7243 --i, t = TREE_CHAIN (t))
7245 tree a;
7246 if (i == saved_depth)
7247 a = coerce_template_parms (TREE_VALUE (t),
7248 arglist, gen_tmpl,
7249 complain,
7250 /*require_all_args=*/true,
7251 /*use_default_args=*/true);
7252 else
7253 /* Outer levels should have already been coerced. */
7254 a = TMPL_ARGS_LEVEL (arglist, i);
7256 /* Don't process further if one of the levels fails. */
7257 if (a == error_mark_node)
7259 /* Restore the ARGLIST to its full size. */
7260 TREE_VEC_LENGTH (arglist) = saved_depth;
7261 return error_mark_node;
7264 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7266 /* We temporarily reduce the length of the ARGLIST so
7267 that coerce_template_parms will see only the arguments
7268 corresponding to the template parameters it is
7269 examining. */
7270 TREE_VEC_LENGTH (arglist)--;
7273 /* Restore the ARGLIST to its full size. */
7274 TREE_VEC_LENGTH (arglist) = saved_depth;
7276 arglist = bound_args;
7278 else
7279 arglist
7280 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7281 INNERMOST_TEMPLATE_ARGS (arglist),
7282 gen_tmpl,
7283 complain,
7284 /*require_all_args=*/true,
7285 /*use_default_args=*/true);
7287 if (arglist == error_mark_node)
7288 /* We were unable to bind the arguments. */
7289 return error_mark_node;
7291 /* In the scope of a template class, explicit references to the
7292 template class refer to the type of the template, not any
7293 instantiation of it. For example, in:
7295 template <class T> class C { void f(C<T>); }
7297 the `C<T>' is just the same as `C'. Outside of the
7298 class, however, such a reference is an instantiation. */
7299 if ((entering_scope
7300 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7301 || currently_open_class (template_type))
7302 /* comp_template_args is expensive, check it last. */
7303 && comp_template_args (TYPE_TI_ARGS (template_type),
7304 arglist))
7305 return template_type;
7307 /* If we already have this specialization, return it. */
7308 elt.tmpl = gen_tmpl;
7309 elt.args = arglist;
7310 hash = hash_specialization (&elt);
7311 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7312 &elt, hash);
7314 if (entry)
7315 return entry->spec;
7317 is_dependent_type = uses_template_parms (arglist);
7319 /* If the deduced arguments are invalid, then the binding
7320 failed. */
7321 if (!is_dependent_type
7322 && check_instantiated_args (gen_tmpl,
7323 INNERMOST_TEMPLATE_ARGS (arglist),
7324 complain))
7325 return error_mark_node;
7327 if (!is_dependent_type
7328 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7329 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7330 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7332 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7333 DECL_NAME (gen_tmpl),
7334 /*tag_scope=*/ts_global);
7335 return found;
7338 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7339 complain, in_decl);
7340 if (context == error_mark_node)
7341 return error_mark_node;
7343 if (!context)
7344 context = global_namespace;
7346 /* Create the type. */
7347 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7349 if (!is_dependent_type)
7351 set_current_access_from_decl (TYPE_NAME (template_type));
7352 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7353 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7354 arglist, complain, in_decl),
7355 SCOPED_ENUM_P (template_type), NULL);
7357 else
7359 /* We don't want to call start_enum for this type, since
7360 the values for the enumeration constants may involve
7361 template parameters. And, no one should be interested
7362 in the enumeration constants for such a type. */
7363 t = cxx_make_type (ENUMERAL_TYPE);
7364 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7366 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7367 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7368 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7370 else if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7372 /* The user referred to a specialization of an alias
7373 template represented by GEN_TMPL.
7375 [temp.alias]/2 says:
7377 When a template-id refers to the specialization of an
7378 alias template, it is equivalent to the associated
7379 type obtained by substitution of its
7380 template-arguments for the template-parameters in the
7381 type-id of the alias template. */
7383 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
7384 /* Note that the call above (by indirectly calling
7385 register_specialization in tsubst_decl) registers the
7386 TYPE_DECL representing the specialization of the alias
7387 template. So next time someone substitutes ARGLIST for
7388 the template parms into the alias template (GEN_TMPL),
7389 she'll get that TYPE_DECL back. */
7391 if (t == error_mark_node)
7392 return t;
7394 else if (CLASS_TYPE_P (template_type))
7396 t = make_class_type (TREE_CODE (template_type));
7397 CLASSTYPE_DECLARED_CLASS (t)
7398 = CLASSTYPE_DECLARED_CLASS (template_type);
7399 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7400 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7402 /* A local class. Make sure the decl gets registered properly. */
7403 if (context == current_function_decl)
7404 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7406 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7407 /* This instantiation is another name for the primary
7408 template type. Set the TYPE_CANONICAL field
7409 appropriately. */
7410 TYPE_CANONICAL (t) = template_type;
7411 else if (any_template_arguments_need_structural_equality_p (arglist))
7412 /* Some of the template arguments require structural
7413 equality testing, so this template class requires
7414 structural equality testing. */
7415 SET_TYPE_STRUCTURAL_EQUALITY (t);
7417 else
7418 gcc_unreachable ();
7420 /* If we called start_enum or pushtag above, this information
7421 will already be set up. */
7422 if (!TYPE_NAME (t))
7424 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7426 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7427 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7428 DECL_SOURCE_LOCATION (type_decl)
7429 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7431 else
7432 type_decl = TYPE_NAME (t);
7434 if (CLASS_TYPE_P (template_type))
7436 TREE_PRIVATE (type_decl)
7437 = TREE_PRIVATE (TYPE_MAIN_DECL (template_type));
7438 TREE_PROTECTED (type_decl)
7439 = TREE_PROTECTED (TYPE_MAIN_DECL (template_type));
7440 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7442 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7443 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7447 /* Let's consider the explicit specialization of a member
7448 of a class template specialization that is implicitely instantiated,
7449 e.g.:
7450 template<class T>
7451 struct S
7453 template<class U> struct M {}; //#0
7456 template<>
7457 template<>
7458 struct S<int>::M<char> //#1
7460 int i;
7462 [temp.expl.spec]/4 says this is valid.
7464 In this case, when we write:
7465 S<int>::M<char> m;
7467 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7468 the one of #0.
7470 When we encounter #1, we want to store the partial instantiation
7471 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7473 For all cases other than this "explicit specialization of member of a
7474 class template", we just want to store the most general template into
7475 the CLASSTYPE_TI_TEMPLATE of M.
7477 This case of "explicit specialization of member of a class template"
7478 only happens when:
7479 1/ the enclosing class is an instantiation of, and therefore not
7480 the same as, the context of the most general template, and
7481 2/ we aren't looking at the partial instantiation itself, i.e.
7482 the innermost arguments are not the same as the innermost parms of
7483 the most general template.
7485 So it's only when 1/ and 2/ happens that we want to use the partial
7486 instantiation of the member template in lieu of its most general
7487 template. */
7489 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7490 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7491 /* the enclosing class must be an instantiation... */
7492 && CLASS_TYPE_P (context)
7493 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7495 tree partial_inst_args;
7496 TREE_VEC_LENGTH (arglist)--;
7497 ++processing_template_decl;
7498 partial_inst_args =
7499 tsubst (INNERMOST_TEMPLATE_ARGS
7500 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7501 arglist, complain, NULL_TREE);
7502 --processing_template_decl;
7503 TREE_VEC_LENGTH (arglist)++;
7504 use_partial_inst_tmpl =
7505 /*...and we must not be looking at the partial instantiation
7506 itself. */
7507 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7508 partial_inst_args);
7511 if (!use_partial_inst_tmpl)
7512 /* This case is easy; there are no member templates involved. */
7513 found = gen_tmpl;
7514 else
7516 /* This is a full instantiation of a member template. Find
7517 the partial instantiation of which this is an instance. */
7519 /* Temporarily reduce by one the number of levels in the ARGLIST
7520 so as to avoid comparing the last set of arguments. */
7521 TREE_VEC_LENGTH (arglist)--;
7522 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7523 TREE_VEC_LENGTH (arglist)++;
7524 /* FOUND is either a proper class type, or an alias
7525 template specialization. In the later case, it's a
7526 TYPE_DECL, resulting from the substituting of arguments
7527 for parameters in the TYPE_DECL of the alias template
7528 done earlier. So be careful while getting the template
7529 of FOUND. */
7530 found = TREE_CODE (found) == TYPE_DECL
7531 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
7532 : CLASSTYPE_TI_TEMPLATE (found);
7535 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7537 elt.spec = t;
7538 slot = htab_find_slot_with_hash (type_specializations,
7539 &elt, hash, INSERT);
7540 entry = ggc_alloc_spec_entry ();
7541 *entry = elt;
7542 *slot = entry;
7544 /* Note this use of the partial instantiation so we can check it
7545 later in maybe_process_partial_specialization. */
7546 DECL_TEMPLATE_INSTANTIATIONS (templ)
7547 = tree_cons (arglist, t,
7548 DECL_TEMPLATE_INSTANTIATIONS (templ));
7550 if (TREE_CODE (template_type) == ENUMERAL_TYPE && !is_dependent_type)
7551 /* Now that the type has been registered on the instantiations
7552 list, we set up the enumerators. Because the enumeration
7553 constants may involve the enumeration type itself, we make
7554 sure to register the type first, and then create the
7555 constants. That way, doing tsubst_expr for the enumeration
7556 constants won't result in recursive calls here; we'll find
7557 the instantiation and exit above. */
7558 tsubst_enum (template_type, t, arglist);
7560 if (CLASS_TYPE_P (template_type) && is_dependent_type)
7561 /* If the type makes use of template parameters, the
7562 code that generates debugging information will crash. */
7563 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7565 /* Possibly limit visibility based on template args. */
7566 TREE_PUBLIC (type_decl) = 1;
7567 determine_visibility (type_decl);
7569 return t;
7573 /* Wrapper for lookup_template_class_1. */
7575 tree
7576 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7577 int entering_scope, tsubst_flags_t complain)
7579 tree ret;
7580 timevar_push (TV_TEMPLATE_INST);
7581 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7582 entering_scope, complain);
7583 timevar_pop (TV_TEMPLATE_INST);
7584 return ret;
7587 struct pair_fn_data
7589 tree_fn_t fn;
7590 void *data;
7591 /* True when we should also visit template parameters that occur in
7592 non-deduced contexts. */
7593 bool include_nondeduced_p;
7594 struct pointer_set_t *visited;
7597 /* Called from for_each_template_parm via walk_tree. */
7599 static tree
7600 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7602 tree t = *tp;
7603 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7604 tree_fn_t fn = pfd->fn;
7605 void *data = pfd->data;
7607 if (TYPE_P (t)
7608 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7609 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7610 pfd->include_nondeduced_p))
7611 return error_mark_node;
7613 switch (TREE_CODE (t))
7615 case RECORD_TYPE:
7616 if (TYPE_PTRMEMFUNC_P (t))
7617 break;
7618 /* Fall through. */
7620 case UNION_TYPE:
7621 case ENUMERAL_TYPE:
7622 if (!TYPE_TEMPLATE_INFO (t))
7623 *walk_subtrees = 0;
7624 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7625 fn, data, pfd->visited,
7626 pfd->include_nondeduced_p))
7627 return error_mark_node;
7628 break;
7630 case INTEGER_TYPE:
7631 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7632 fn, data, pfd->visited,
7633 pfd->include_nondeduced_p)
7634 || for_each_template_parm (TYPE_MAX_VALUE (t),
7635 fn, data, pfd->visited,
7636 pfd->include_nondeduced_p))
7637 return error_mark_node;
7638 break;
7640 case METHOD_TYPE:
7641 /* Since we're not going to walk subtrees, we have to do this
7642 explicitly here. */
7643 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7644 pfd->visited, pfd->include_nondeduced_p))
7645 return error_mark_node;
7646 /* Fall through. */
7648 case FUNCTION_TYPE:
7649 /* Check the return type. */
7650 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7651 pfd->include_nondeduced_p))
7652 return error_mark_node;
7654 /* Check the parameter types. Since default arguments are not
7655 instantiated until they are needed, the TYPE_ARG_TYPES may
7656 contain expressions that involve template parameters. But,
7657 no-one should be looking at them yet. And, once they're
7658 instantiated, they don't contain template parameters, so
7659 there's no point in looking at them then, either. */
7661 tree parm;
7663 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7664 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7665 pfd->visited, pfd->include_nondeduced_p))
7666 return error_mark_node;
7668 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7669 want walk_tree walking into them itself. */
7670 *walk_subtrees = 0;
7672 break;
7674 case TYPEOF_TYPE:
7675 case UNDERLYING_TYPE:
7676 if (pfd->include_nondeduced_p
7677 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7678 pfd->visited,
7679 pfd->include_nondeduced_p))
7680 return error_mark_node;
7681 break;
7683 case FUNCTION_DECL:
7684 case VAR_DECL:
7685 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7686 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7687 pfd->visited, pfd->include_nondeduced_p))
7688 return error_mark_node;
7689 /* Fall through. */
7691 case PARM_DECL:
7692 case CONST_DECL:
7693 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7694 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7695 pfd->visited, pfd->include_nondeduced_p))
7696 return error_mark_node;
7697 if (DECL_CONTEXT (t)
7698 && pfd->include_nondeduced_p
7699 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7700 pfd->visited, pfd->include_nondeduced_p))
7701 return error_mark_node;
7702 break;
7704 case BOUND_TEMPLATE_TEMPLATE_PARM:
7705 /* Record template parameters such as `T' inside `TT<T>'. */
7706 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7707 pfd->include_nondeduced_p))
7708 return error_mark_node;
7709 /* Fall through. */
7711 case TEMPLATE_TEMPLATE_PARM:
7712 case TEMPLATE_TYPE_PARM:
7713 case TEMPLATE_PARM_INDEX:
7714 if (fn && (*fn)(t, data))
7715 return error_mark_node;
7716 else if (!fn)
7717 return error_mark_node;
7718 break;
7720 case TEMPLATE_DECL:
7721 /* A template template parameter is encountered. */
7722 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7723 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7724 pfd->include_nondeduced_p))
7725 return error_mark_node;
7727 /* Already substituted template template parameter */
7728 *walk_subtrees = 0;
7729 break;
7731 case TYPENAME_TYPE:
7732 if (!fn
7733 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7734 data, pfd->visited,
7735 pfd->include_nondeduced_p))
7736 return error_mark_node;
7737 break;
7739 case CONSTRUCTOR:
7740 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7741 && pfd->include_nondeduced_p
7742 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7743 (TREE_TYPE (t)), fn, data,
7744 pfd->visited, pfd->include_nondeduced_p))
7745 return error_mark_node;
7746 break;
7748 case INDIRECT_REF:
7749 case COMPONENT_REF:
7750 /* If there's no type, then this thing must be some expression
7751 involving template parameters. */
7752 if (!fn && !TREE_TYPE (t))
7753 return error_mark_node;
7754 break;
7756 case MODOP_EXPR:
7757 case CAST_EXPR:
7758 case IMPLICIT_CONV_EXPR:
7759 case REINTERPRET_CAST_EXPR:
7760 case CONST_CAST_EXPR:
7761 case STATIC_CAST_EXPR:
7762 case DYNAMIC_CAST_EXPR:
7763 case ARROW_EXPR:
7764 case DOTSTAR_EXPR:
7765 case TYPEID_EXPR:
7766 case PSEUDO_DTOR_EXPR:
7767 if (!fn)
7768 return error_mark_node;
7769 break;
7771 default:
7772 break;
7775 /* We didn't find any template parameters we liked. */
7776 return NULL_TREE;
7779 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7780 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7781 call FN with the parameter and the DATA.
7782 If FN returns nonzero, the iteration is terminated, and
7783 for_each_template_parm returns 1. Otherwise, the iteration
7784 continues. If FN never returns a nonzero value, the value
7785 returned by for_each_template_parm is 0. If FN is NULL, it is
7786 considered to be the function which always returns 1.
7788 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7789 parameters that occur in non-deduced contexts. When false, only
7790 visits those template parameters that can be deduced. */
7792 static int
7793 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7794 struct pointer_set_t *visited,
7795 bool include_nondeduced_p)
7797 struct pair_fn_data pfd;
7798 int result;
7800 /* Set up. */
7801 pfd.fn = fn;
7802 pfd.data = data;
7803 pfd.include_nondeduced_p = include_nondeduced_p;
7805 /* Walk the tree. (Conceptually, we would like to walk without
7806 duplicates, but for_each_template_parm_r recursively calls
7807 for_each_template_parm, so we would need to reorganize a fair
7808 bit to use walk_tree_without_duplicates, so we keep our own
7809 visited list.) */
7810 if (visited)
7811 pfd.visited = visited;
7812 else
7813 pfd.visited = pointer_set_create ();
7814 result = cp_walk_tree (&t,
7815 for_each_template_parm_r,
7816 &pfd,
7817 pfd.visited) != NULL_TREE;
7819 /* Clean up. */
7820 if (!visited)
7822 pointer_set_destroy (pfd.visited);
7823 pfd.visited = 0;
7826 return result;
7829 /* Returns true if T depends on any template parameter. */
7832 uses_template_parms (tree t)
7834 bool dependent_p;
7835 int saved_processing_template_decl;
7837 saved_processing_template_decl = processing_template_decl;
7838 if (!saved_processing_template_decl)
7839 processing_template_decl = 1;
7840 if (TYPE_P (t))
7841 dependent_p = dependent_type_p (t);
7842 else if (TREE_CODE (t) == TREE_VEC)
7843 dependent_p = any_dependent_template_arguments_p (t);
7844 else if (TREE_CODE (t) == TREE_LIST)
7845 dependent_p = (uses_template_parms (TREE_VALUE (t))
7846 || uses_template_parms (TREE_CHAIN (t)));
7847 else if (TREE_CODE (t) == TYPE_DECL)
7848 dependent_p = dependent_type_p (TREE_TYPE (t));
7849 else if (DECL_P (t)
7850 || EXPR_P (t)
7851 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7852 || TREE_CODE (t) == OVERLOAD
7853 || BASELINK_P (t)
7854 || identifier_p (t)
7855 || TREE_CODE (t) == TRAIT_EXPR
7856 || TREE_CODE (t) == CONSTRUCTOR
7857 || CONSTANT_CLASS_P (t))
7858 dependent_p = (type_dependent_expression_p (t)
7859 || value_dependent_expression_p (t));
7860 else
7862 gcc_assert (t == error_mark_node);
7863 dependent_p = false;
7866 processing_template_decl = saved_processing_template_decl;
7868 return dependent_p;
7871 /* Returns true iff current_function_decl is an incompletely instantiated
7872 template. Useful instead of processing_template_decl because the latter
7873 is set to 0 during fold_non_dependent_expr. */
7875 bool
7876 in_template_function (void)
7878 tree fn = current_function_decl;
7879 bool ret;
7880 ++processing_template_decl;
7881 ret = (fn && DECL_LANG_SPECIFIC (fn)
7882 && DECL_TEMPLATE_INFO (fn)
7883 && any_dependent_template_arguments_p (DECL_TI_ARGS (fn)));
7884 --processing_template_decl;
7885 return ret;
7888 /* Returns true if T depends on any template parameter with level LEVEL. */
7891 uses_template_parms_level (tree t, int level)
7893 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7894 /*include_nondeduced_p=*/true);
7897 /* Returns TRUE iff INST is an instantiation we don't need to do in an
7898 ill-formed translation unit, i.e. a variable or function that isn't
7899 usable in a constant expression. */
7901 static inline bool
7902 neglectable_inst_p (tree d)
7904 return (DECL_P (d)
7905 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
7906 : decl_maybe_constant_var_p (d)));
7909 /* Returns TRUE iff we should refuse to instantiate DECL because it's
7910 neglectable and instantiated from within an erroneous instantiation. */
7912 static bool
7913 limit_bad_template_recursion (tree decl)
7915 struct tinst_level *lev = current_tinst_level;
7916 int errs = errorcount + sorrycount;
7917 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
7918 return false;
7920 for (; lev; lev = lev->next)
7921 if (neglectable_inst_p (lev->decl))
7922 break;
7924 return (lev && errs > lev->errors);
7927 static int tinst_depth;
7928 extern int max_tinst_depth;
7929 int depth_reached;
7931 static GTY(()) struct tinst_level *last_error_tinst_level;
7933 /* We're starting to instantiate D; record the template instantiation context
7934 for diagnostics and to restore it later. */
7937 push_tinst_level (tree d)
7939 struct tinst_level *new_level;
7941 if (tinst_depth >= max_tinst_depth)
7943 last_error_tinst_level = current_tinst_level;
7944 if (TREE_CODE (d) == TREE_LIST)
7945 error ("template instantiation depth exceeds maximum of %d (use "
7946 "-ftemplate-depth= to increase the maximum) substituting %qS",
7947 max_tinst_depth, d);
7948 else
7949 error ("template instantiation depth exceeds maximum of %d (use "
7950 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7951 max_tinst_depth, d);
7953 print_instantiation_context ();
7955 return 0;
7958 /* If the current instantiation caused problems, don't let it instantiate
7959 anything else. Do allow deduction substitution and decls usable in
7960 constant expressions. */
7961 if (limit_bad_template_recursion (d))
7962 return 0;
7964 new_level = ggc_alloc_tinst_level ();
7965 new_level->decl = d;
7966 new_level->locus = input_location;
7967 new_level->errors = errorcount+sorrycount;
7968 new_level->in_system_header_p = in_system_header;
7969 new_level->next = current_tinst_level;
7970 current_tinst_level = new_level;
7972 ++tinst_depth;
7973 if (GATHER_STATISTICS && (tinst_depth > depth_reached))
7974 depth_reached = tinst_depth;
7976 return 1;
7979 /* We're done instantiating this template; return to the instantiation
7980 context. */
7982 void
7983 pop_tinst_level (void)
7985 /* Restore the filename and line number stashed away when we started
7986 this instantiation. */
7987 input_location = current_tinst_level->locus;
7988 current_tinst_level = current_tinst_level->next;
7989 --tinst_depth;
7992 /* We're instantiating a deferred template; restore the template
7993 instantiation context in which the instantiation was requested, which
7994 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7996 static tree
7997 reopen_tinst_level (struct tinst_level *level)
7999 struct tinst_level *t;
8001 tinst_depth = 0;
8002 for (t = level; t; t = t->next)
8003 ++tinst_depth;
8005 current_tinst_level = level;
8006 pop_tinst_level ();
8007 if (current_tinst_level)
8008 current_tinst_level->errors = errorcount+sorrycount;
8009 return level->decl;
8012 /* Returns the TINST_LEVEL which gives the original instantiation
8013 context. */
8015 struct tinst_level *
8016 outermost_tinst_level (void)
8018 struct tinst_level *level = current_tinst_level;
8019 if (level)
8020 while (level->next)
8021 level = level->next;
8022 return level;
8025 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8026 vector of template arguments, as for tsubst.
8028 Returns an appropriate tsubst'd friend declaration. */
8030 static tree
8031 tsubst_friend_function (tree decl, tree args)
8033 tree new_friend;
8035 if (TREE_CODE (decl) == FUNCTION_DECL
8036 && DECL_TEMPLATE_INSTANTIATION (decl)
8037 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
8038 /* This was a friend declared with an explicit template
8039 argument list, e.g.:
8041 friend void f<>(T);
8043 to indicate that f was a template instantiation, not a new
8044 function declaration. Now, we have to figure out what
8045 instantiation of what template. */
8047 tree template_id, arglist, fns;
8048 tree new_args;
8049 tree tmpl;
8050 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
8052 /* Friend functions are looked up in the containing namespace scope.
8053 We must enter that scope, to avoid finding member functions of the
8054 current class with same name. */
8055 push_nested_namespace (ns);
8056 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
8057 tf_warning_or_error, NULL_TREE,
8058 /*integral_constant_expression_p=*/false);
8059 pop_nested_namespace (ns);
8060 arglist = tsubst (DECL_TI_ARGS (decl), args,
8061 tf_warning_or_error, NULL_TREE);
8062 template_id = lookup_template_function (fns, arglist);
8064 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8065 tmpl = determine_specialization (template_id, new_friend,
8066 &new_args,
8067 /*need_member_template=*/0,
8068 TREE_VEC_LENGTH (args),
8069 tsk_none);
8070 return instantiate_template (tmpl, new_args, tf_error);
8073 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8075 /* The NEW_FRIEND will look like an instantiation, to the
8076 compiler, but is not an instantiation from the point of view of
8077 the language. For example, we might have had:
8079 template <class T> struct S {
8080 template <class U> friend void f(T, U);
8083 Then, in S<int>, template <class U> void f(int, U) is not an
8084 instantiation of anything. */
8085 if (new_friend == error_mark_node)
8086 return error_mark_node;
8088 DECL_USE_TEMPLATE (new_friend) = 0;
8089 if (TREE_CODE (decl) == TEMPLATE_DECL)
8091 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
8092 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
8093 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
8096 /* The mangled name for the NEW_FRIEND is incorrect. The function
8097 is not a template instantiation and should not be mangled like
8098 one. Therefore, we forget the mangling here; we'll recompute it
8099 later if we need it. */
8100 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
8102 SET_DECL_RTL (new_friend, NULL);
8103 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
8106 if (DECL_NAMESPACE_SCOPE_P (new_friend))
8108 tree old_decl;
8109 tree new_friend_template_info;
8110 tree new_friend_result_template_info;
8111 tree ns;
8112 int new_friend_is_defn;
8114 /* We must save some information from NEW_FRIEND before calling
8115 duplicate decls since that function will free NEW_FRIEND if
8116 possible. */
8117 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
8118 new_friend_is_defn =
8119 (DECL_INITIAL (DECL_TEMPLATE_RESULT
8120 (template_for_substitution (new_friend)))
8121 != NULL_TREE);
8122 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
8124 /* This declaration is a `primary' template. */
8125 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8127 new_friend_result_template_info
8128 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8130 else
8131 new_friend_result_template_info = NULL_TREE;
8133 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8134 if (new_friend_is_defn)
8135 DECL_INITIAL (new_friend) = error_mark_node;
8137 /* Inside pushdecl_namespace_level, we will push into the
8138 current namespace. However, the friend function should go
8139 into the namespace of the template. */
8140 ns = decl_namespace_context (new_friend);
8141 push_nested_namespace (ns);
8142 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8143 pop_nested_namespace (ns);
8145 if (old_decl == error_mark_node)
8146 return error_mark_node;
8148 if (old_decl != new_friend)
8150 /* This new friend declaration matched an existing
8151 declaration. For example, given:
8153 template <class T> void f(T);
8154 template <class U> class C {
8155 template <class T> friend void f(T) {}
8158 the friend declaration actually provides the definition
8159 of `f', once C has been instantiated for some type. So,
8160 old_decl will be the out-of-class template declaration,
8161 while new_friend is the in-class definition.
8163 But, if `f' was called before this point, the
8164 instantiation of `f' will have DECL_TI_ARGS corresponding
8165 to `T' but not to `U', references to which might appear
8166 in the definition of `f'. Previously, the most general
8167 template for an instantiation of `f' was the out-of-class
8168 version; now it is the in-class version. Therefore, we
8169 run through all specialization of `f', adding to their
8170 DECL_TI_ARGS appropriately. In particular, they need a
8171 new set of outer arguments, corresponding to the
8172 arguments for this class instantiation.
8174 The same situation can arise with something like this:
8176 friend void f(int);
8177 template <class T> class C {
8178 friend void f(T) {}
8181 when `C<int>' is instantiated. Now, `f(int)' is defined
8182 in the class. */
8184 if (!new_friend_is_defn)
8185 /* On the other hand, if the in-class declaration does
8186 *not* provide a definition, then we don't want to alter
8187 existing definitions. We can just leave everything
8188 alone. */
8190 else
8192 tree new_template = TI_TEMPLATE (new_friend_template_info);
8193 tree new_args = TI_ARGS (new_friend_template_info);
8195 /* Overwrite whatever template info was there before, if
8196 any, with the new template information pertaining to
8197 the declaration. */
8198 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8200 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8202 /* We should have called reregister_specialization in
8203 duplicate_decls. */
8204 gcc_assert (retrieve_specialization (new_template,
8205 new_args, 0)
8206 == old_decl);
8208 /* Instantiate it if the global has already been used. */
8209 if (DECL_ODR_USED (old_decl))
8210 instantiate_decl (old_decl, /*defer_ok=*/true,
8211 /*expl_inst_class_mem_p=*/false);
8213 else
8215 tree t;
8217 /* Indicate that the old function template is a partial
8218 instantiation. */
8219 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8220 = new_friend_result_template_info;
8222 gcc_assert (new_template
8223 == most_general_template (new_template));
8224 gcc_assert (new_template != old_decl);
8226 /* Reassign any specializations already in the hash table
8227 to the new more general template, and add the
8228 additional template args. */
8229 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8230 t != NULL_TREE;
8231 t = TREE_CHAIN (t))
8233 tree spec = TREE_VALUE (t);
8234 spec_entry elt;
8236 elt.tmpl = old_decl;
8237 elt.args = DECL_TI_ARGS (spec);
8238 elt.spec = NULL_TREE;
8240 htab_remove_elt (decl_specializations, &elt);
8242 DECL_TI_ARGS (spec)
8243 = add_outermost_template_args (new_args,
8244 DECL_TI_ARGS (spec));
8246 register_specialization
8247 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8250 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8254 /* The information from NEW_FRIEND has been merged into OLD_DECL
8255 by duplicate_decls. */
8256 new_friend = old_decl;
8259 else
8261 tree context = DECL_CONTEXT (new_friend);
8262 bool dependent_p;
8264 /* In the code
8265 template <class T> class C {
8266 template <class U> friend void C1<U>::f (); // case 1
8267 friend void C2<T>::f (); // case 2
8269 we only need to make sure CONTEXT is a complete type for
8270 case 2. To distinguish between the two cases, we note that
8271 CONTEXT of case 1 remains dependent type after tsubst while
8272 this isn't true for case 2. */
8273 ++processing_template_decl;
8274 dependent_p = dependent_type_p (context);
8275 --processing_template_decl;
8277 if (!dependent_p
8278 && !complete_type_or_else (context, NULL_TREE))
8279 return error_mark_node;
8281 if (COMPLETE_TYPE_P (context))
8283 /* Check to see that the declaration is really present, and,
8284 possibly obtain an improved declaration. */
8285 tree fn = check_classfn (context,
8286 new_friend, NULL_TREE);
8288 if (fn)
8289 new_friend = fn;
8293 return new_friend;
8296 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8297 template arguments, as for tsubst.
8299 Returns an appropriate tsubst'd friend type or error_mark_node on
8300 failure. */
8302 static tree
8303 tsubst_friend_class (tree friend_tmpl, tree args)
8305 tree friend_type;
8306 tree tmpl;
8307 tree context;
8309 if (DECL_TEMPLATE_TEMPLATE_PARM_P (friend_tmpl))
8311 tree t = tsubst (TREE_TYPE (friend_tmpl), args, tf_none, NULL_TREE);
8312 return TREE_TYPE (t);
8315 context = CP_DECL_CONTEXT (friend_tmpl);
8317 if (context != global_namespace)
8319 if (TREE_CODE (context) == NAMESPACE_DECL)
8320 push_nested_namespace (context);
8321 else
8322 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8325 /* Look for a class template declaration. We look for hidden names
8326 because two friend declarations of the same template are the
8327 same. For example, in:
8329 struct A {
8330 template <typename> friend class F;
8332 template <typename> struct B {
8333 template <typename> friend class F;
8336 both F templates are the same. */
8337 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8338 /*block_p=*/true, 0, LOOKUP_HIDDEN);
8340 /* But, if we don't find one, it might be because we're in a
8341 situation like this:
8343 template <class T>
8344 struct S {
8345 template <class U>
8346 friend struct S;
8349 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8350 for `S<int>', not the TEMPLATE_DECL. */
8351 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8353 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8354 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8357 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8359 /* The friend template has already been declared. Just
8360 check to see that the declarations match, and install any new
8361 default parameters. We must tsubst the default parameters,
8362 of course. We only need the innermost template parameters
8363 because that is all that redeclare_class_template will look
8364 at. */
8365 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8366 > TMPL_ARGS_DEPTH (args))
8368 tree parms;
8369 location_t saved_input_location;
8370 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8371 args, tf_warning_or_error);
8373 saved_input_location = input_location;
8374 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8375 redeclare_class_template (TREE_TYPE (tmpl), parms);
8376 input_location = saved_input_location;
8380 friend_type = TREE_TYPE (tmpl);
8382 else
8384 /* The friend template has not already been declared. In this
8385 case, the instantiation of the template class will cause the
8386 injection of this template into the global scope. */
8387 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8388 if (tmpl == error_mark_node)
8389 return error_mark_node;
8391 /* The new TMPL is not an instantiation of anything, so we
8392 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8393 the new type because that is supposed to be the corresponding
8394 template decl, i.e., TMPL. */
8395 DECL_USE_TEMPLATE (tmpl) = 0;
8396 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8397 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8398 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8399 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8401 /* Inject this template into the global scope. */
8402 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8405 if (context != global_namespace)
8407 if (TREE_CODE (context) == NAMESPACE_DECL)
8408 pop_nested_namespace (context);
8409 else
8410 pop_nested_class ();
8413 return friend_type;
8416 /* Returns zero if TYPE cannot be completed later due to circularity.
8417 Otherwise returns one. */
8419 static int
8420 can_complete_type_without_circularity (tree type)
8422 if (type == NULL_TREE || type == error_mark_node)
8423 return 0;
8424 else if (COMPLETE_TYPE_P (type))
8425 return 1;
8426 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8427 return can_complete_type_without_circularity (TREE_TYPE (type));
8428 else if (CLASS_TYPE_P (type)
8429 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8430 return 0;
8431 else
8432 return 1;
8435 /* Apply any attributes which had to be deferred until instantiation
8436 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8437 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8439 static void
8440 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8441 tree args, tsubst_flags_t complain, tree in_decl)
8443 tree last_dep = NULL_TREE;
8444 tree t;
8445 tree *p;
8447 for (t = attributes; t; t = TREE_CHAIN (t))
8448 if (ATTR_IS_DEPENDENT (t))
8450 last_dep = t;
8451 attributes = copy_list (attributes);
8452 break;
8455 if (DECL_P (*decl_p))
8457 if (TREE_TYPE (*decl_p) == error_mark_node)
8458 return;
8459 p = &DECL_ATTRIBUTES (*decl_p);
8461 else
8462 p = &TYPE_ATTRIBUTES (*decl_p);
8464 if (last_dep)
8466 tree late_attrs = NULL_TREE;
8467 tree *q = &late_attrs;
8469 for (*p = attributes; *p; )
8471 t = *p;
8472 if (ATTR_IS_DEPENDENT (t))
8474 *p = TREE_CHAIN (t);
8475 TREE_CHAIN (t) = NULL_TREE;
8476 /* If the first attribute argument is an identifier, don't
8477 pass it through tsubst. Attributes like mode, format,
8478 cleanup and several target specific attributes expect it
8479 unmodified. */
8480 if (TREE_VALUE (t)
8481 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8482 && TREE_VALUE (TREE_VALUE (t))
8483 && (identifier_p (TREE_VALUE (TREE_VALUE (t)))))
8485 tree chain
8486 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8487 in_decl,
8488 /*integral_constant_expression_p=*/false);
8489 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8490 TREE_VALUE (t)
8491 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8492 chain);
8494 else
8495 TREE_VALUE (t)
8496 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8497 /*integral_constant_expression_p=*/false);
8498 *q = t;
8499 q = &TREE_CHAIN (t);
8501 else
8502 p = &TREE_CHAIN (t);
8505 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8509 /* Perform (or defer) access check for typedefs that were referenced
8510 from within the template TMPL code.
8511 This is a subroutine of instantiate_decl and instantiate_class_template.
8512 TMPL is the template to consider and TARGS is the list of arguments of
8513 that template. */
8515 static void
8516 perform_typedefs_access_check (tree tmpl, tree targs)
8518 location_t saved_location;
8519 unsigned i;
8520 qualified_typedef_usage_t *iter;
8522 if (!tmpl
8523 || (!CLASS_TYPE_P (tmpl)
8524 && TREE_CODE (tmpl) != FUNCTION_DECL))
8525 return;
8527 saved_location = input_location;
8528 FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (tmpl), i, iter)
8530 tree type_decl = iter->typedef_decl;
8531 tree type_scope = iter->context;
8533 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8534 continue;
8536 if (uses_template_parms (type_decl))
8537 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8538 if (uses_template_parms (type_scope))
8539 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8541 /* Make access check error messages point to the location
8542 of the use of the typedef. */
8543 input_location = iter->locus;
8544 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8545 type_decl, type_decl,
8546 tf_warning_or_error);
8548 input_location = saved_location;
8551 static tree
8552 instantiate_class_template_1 (tree type)
8554 tree templ, args, pattern, t, member;
8555 tree typedecl;
8556 tree pbinfo;
8557 tree base_list;
8558 unsigned int saved_maximum_field_alignment;
8559 tree fn_context;
8561 if (type == error_mark_node)
8562 return error_mark_node;
8564 if (COMPLETE_OR_OPEN_TYPE_P (type)
8565 || uses_template_parms (type))
8566 return type;
8568 /* Figure out which template is being instantiated. */
8569 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8570 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8572 /* Determine what specialization of the original template to
8573 instantiate. */
8574 t = most_specialized_class (type, templ, tf_warning_or_error);
8575 if (t == error_mark_node)
8577 TYPE_BEING_DEFINED (type) = 1;
8578 return error_mark_node;
8580 else if (t)
8582 /* This TYPE is actually an instantiation of a partial
8583 specialization. We replace the innermost set of ARGS with
8584 the arguments appropriate for substitution. For example,
8585 given:
8587 template <class T> struct S {};
8588 template <class T> struct S<T*> {};
8590 and supposing that we are instantiating S<int*>, ARGS will
8591 presently be {int*} -- but we need {int}. */
8592 pattern = TREE_TYPE (t);
8593 args = TREE_PURPOSE (t);
8595 else
8597 pattern = TREE_TYPE (templ);
8598 args = CLASSTYPE_TI_ARGS (type);
8601 /* If the template we're instantiating is incomplete, then clearly
8602 there's nothing we can do. */
8603 if (!COMPLETE_TYPE_P (pattern))
8604 return type;
8606 /* If we've recursively instantiated too many templates, stop. */
8607 if (! push_tinst_level (type))
8608 return type;
8610 /* Now we're really doing the instantiation. Mark the type as in
8611 the process of being defined. */
8612 TYPE_BEING_DEFINED (type) = 1;
8614 /* We may be in the middle of deferred access check. Disable
8615 it now. */
8616 push_deferring_access_checks (dk_no_deferred);
8618 fn_context = decl_function_context (TYPE_MAIN_DECL (type));
8619 if (!fn_context)
8620 push_to_top_level ();
8621 /* Use #pragma pack from the template context. */
8622 saved_maximum_field_alignment = maximum_field_alignment;
8623 maximum_field_alignment = TYPE_PRECISION (pattern);
8625 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8627 /* Set the input location to the most specialized template definition.
8628 This is needed if tsubsting causes an error. */
8629 typedecl = TYPE_MAIN_DECL (pattern);
8630 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8631 DECL_SOURCE_LOCATION (typedecl);
8633 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8634 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8635 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8636 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8637 if (ANON_AGGR_TYPE_P (pattern))
8638 SET_ANON_AGGR_TYPE_P (type);
8639 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8641 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8642 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8643 /* Adjust visibility for template arguments. */
8644 determine_visibility (TYPE_MAIN_DECL (type));
8646 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8648 pbinfo = TYPE_BINFO (pattern);
8650 /* We should never instantiate a nested class before its enclosing
8651 class; we need to look up the nested class by name before we can
8652 instantiate it, and that lookup should instantiate the enclosing
8653 class. */
8654 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8655 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8657 base_list = NULL_TREE;
8658 if (BINFO_N_BASE_BINFOS (pbinfo))
8660 tree pbase_binfo;
8661 tree pushed_scope;
8662 int i;
8664 /* We must enter the scope containing the type, as that is where
8665 the accessibility of types named in dependent bases are
8666 looked up from. */
8667 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8669 /* Substitute into each of the bases to determine the actual
8670 basetypes. */
8671 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8673 tree base;
8674 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8675 tree expanded_bases = NULL_TREE;
8676 int idx, len = 1;
8678 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8680 expanded_bases =
8681 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8682 args, tf_error, NULL_TREE);
8683 if (expanded_bases == error_mark_node)
8684 continue;
8686 len = TREE_VEC_LENGTH (expanded_bases);
8689 for (idx = 0; idx < len; idx++)
8691 if (expanded_bases)
8692 /* Extract the already-expanded base class. */
8693 base = TREE_VEC_ELT (expanded_bases, idx);
8694 else
8695 /* Substitute to figure out the base class. */
8696 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8697 NULL_TREE);
8699 if (base == error_mark_node)
8700 continue;
8702 base_list = tree_cons (access, base, base_list);
8703 if (BINFO_VIRTUAL_P (pbase_binfo))
8704 TREE_TYPE (base_list) = integer_type_node;
8708 /* The list is now in reverse order; correct that. */
8709 base_list = nreverse (base_list);
8711 if (pushed_scope)
8712 pop_scope (pushed_scope);
8714 /* Now call xref_basetypes to set up all the base-class
8715 information. */
8716 xref_basetypes (type, base_list);
8718 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8719 (int) ATTR_FLAG_TYPE_IN_PLACE,
8720 args, tf_error, NULL_TREE);
8721 fixup_attribute_variants (type);
8723 /* Now that our base classes are set up, enter the scope of the
8724 class, so that name lookups into base classes, etc. will work
8725 correctly. This is precisely analogous to what we do in
8726 begin_class_definition when defining an ordinary non-template
8727 class, except we also need to push the enclosing classes. */
8728 push_nested_class (type);
8730 /* Now members are processed in the order of declaration. */
8731 for (member = CLASSTYPE_DECL_LIST (pattern);
8732 member; member = TREE_CHAIN (member))
8734 tree t = TREE_VALUE (member);
8736 if (TREE_PURPOSE (member))
8738 if (TYPE_P (t))
8740 /* Build new CLASSTYPE_NESTED_UTDS. */
8742 tree newtag;
8743 bool class_template_p;
8745 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8746 && TYPE_LANG_SPECIFIC (t)
8747 && CLASSTYPE_IS_TEMPLATE (t));
8748 /* If the member is a class template, then -- even after
8749 substitution -- there may be dependent types in the
8750 template argument list for the class. We increment
8751 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8752 that function will assume that no types are dependent
8753 when outside of a template. */
8754 if (class_template_p)
8755 ++processing_template_decl;
8756 newtag = tsubst (t, args, tf_error, NULL_TREE);
8757 if (class_template_p)
8758 --processing_template_decl;
8759 if (newtag == error_mark_node)
8760 continue;
8762 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8764 tree name = TYPE_IDENTIFIER (t);
8766 if (class_template_p)
8767 /* Unfortunately, lookup_template_class sets
8768 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8769 instantiation (i.e., for the type of a member
8770 template class nested within a template class.)
8771 This behavior is required for
8772 maybe_process_partial_specialization to work
8773 correctly, but is not accurate in this case;
8774 the TAG is not an instantiation of anything.
8775 (The corresponding TEMPLATE_DECL is an
8776 instantiation, but the TYPE is not.) */
8777 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8779 /* Now, we call pushtag to put this NEWTAG into the scope of
8780 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8781 pushtag calling push_template_decl. We don't have to do
8782 this for enums because it will already have been done in
8783 tsubst_enum. */
8784 if (name)
8785 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8786 pushtag (name, newtag, /*tag_scope=*/ts_current);
8789 else if (TREE_CODE (t) == FUNCTION_DECL
8790 || DECL_FUNCTION_TEMPLATE_P (t))
8792 /* Build new TYPE_METHODS. */
8793 tree r;
8795 if (TREE_CODE (t) == TEMPLATE_DECL)
8796 ++processing_template_decl;
8797 r = tsubst (t, args, tf_error, NULL_TREE);
8798 if (TREE_CODE (t) == TEMPLATE_DECL)
8799 --processing_template_decl;
8800 set_current_access_from_decl (r);
8801 finish_member_declaration (r);
8802 /* Instantiate members marked with attribute used. */
8803 if (r != error_mark_node && DECL_PRESERVE_P (r))
8804 mark_used (r);
8806 else
8808 /* Build new TYPE_FIELDS. */
8809 if (TREE_CODE (t) == STATIC_ASSERT)
8811 tree condition;
8813 ++c_inhibit_evaluation_warnings;
8814 condition =
8815 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8816 tf_warning_or_error, NULL_TREE,
8817 /*integral_constant_expression_p=*/true);
8818 --c_inhibit_evaluation_warnings;
8820 finish_static_assert (condition,
8821 STATIC_ASSERT_MESSAGE (t),
8822 STATIC_ASSERT_SOURCE_LOCATION (t),
8823 /*member_p=*/true);
8825 else if (TREE_CODE (t) != CONST_DECL)
8827 tree r;
8829 /* The file and line for this declaration, to
8830 assist in error message reporting. Since we
8831 called push_tinst_level above, we don't need to
8832 restore these. */
8833 input_location = DECL_SOURCE_LOCATION (t);
8835 if (TREE_CODE (t) == TEMPLATE_DECL)
8836 ++processing_template_decl;
8837 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8838 if (TREE_CODE (t) == TEMPLATE_DECL)
8839 --processing_template_decl;
8840 if (TREE_CODE (r) == VAR_DECL)
8842 /* In [temp.inst]:
8844 [t]he initialization (and any associated
8845 side-effects) of a static data member does
8846 not occur unless the static data member is
8847 itself used in a way that requires the
8848 definition of the static data member to
8849 exist.
8851 Therefore, we do not substitute into the
8852 initialized for the static data member here. */
8853 finish_static_data_member_decl
8855 /*init=*/NULL_TREE,
8856 /*init_const_expr_p=*/false,
8857 /*asmspec_tree=*/NULL_TREE,
8858 /*flags=*/0);
8859 /* Instantiate members marked with attribute used. */
8860 if (r != error_mark_node && DECL_PRESERVE_P (r))
8861 mark_used (r);
8863 else if (TREE_CODE (r) == FIELD_DECL)
8865 /* Determine whether R has a valid type and can be
8866 completed later. If R is invalid, then it is
8867 replaced by error_mark_node so that it will not be
8868 added to TYPE_FIELDS. */
8869 tree rtype = TREE_TYPE (r);
8870 if (can_complete_type_without_circularity (rtype))
8871 complete_type (rtype);
8873 if (!COMPLETE_TYPE_P (rtype))
8875 cxx_incomplete_type_error (r, rtype);
8876 r = error_mark_node;
8880 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8881 such a thing will already have been added to the field
8882 list by tsubst_enum in finish_member_declaration in the
8883 CLASSTYPE_NESTED_UTDS case above. */
8884 if (!(TREE_CODE (r) == TYPE_DECL
8885 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8886 && DECL_ARTIFICIAL (r)))
8888 set_current_access_from_decl (r);
8889 finish_member_declaration (r);
8894 else
8896 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t)
8897 || DECL_TEMPLATE_TEMPLATE_PARM_P (t))
8899 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8901 tree friend_type = t;
8902 bool adjust_processing_template_decl = false;
8904 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8906 /* template <class T> friend class C; */
8907 friend_type = tsubst_friend_class (friend_type, args);
8908 adjust_processing_template_decl = true;
8910 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8912 /* template <class T> friend class C::D; */
8913 friend_type = tsubst (friend_type, args,
8914 tf_warning_or_error, NULL_TREE);
8915 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8916 friend_type = TREE_TYPE (friend_type);
8917 adjust_processing_template_decl = true;
8919 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
8920 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
8922 /* This could be either
8924 friend class T::C;
8926 when dependent_type_p is false or
8928 template <class U> friend class T::C;
8930 otherwise. */
8931 friend_type = tsubst (friend_type, args,
8932 tf_warning_or_error, NULL_TREE);
8933 /* Bump processing_template_decl for correct
8934 dependent_type_p calculation. */
8935 ++processing_template_decl;
8936 if (dependent_type_p (friend_type))
8937 adjust_processing_template_decl = true;
8938 --processing_template_decl;
8940 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8941 && hidden_name_p (TYPE_NAME (friend_type)))
8943 /* friend class C;
8945 where C hasn't been declared yet. Let's lookup name
8946 from namespace scope directly, bypassing any name that
8947 come from dependent base class. */
8948 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8950 /* The call to xref_tag_from_type does injection for friend
8951 classes. */
8952 push_nested_namespace (ns);
8953 friend_type =
8954 xref_tag_from_type (friend_type, NULL_TREE,
8955 /*tag_scope=*/ts_current);
8956 pop_nested_namespace (ns);
8958 else if (uses_template_parms (friend_type))
8959 /* friend class C<T>; */
8960 friend_type = tsubst (friend_type, args,
8961 tf_warning_or_error, NULL_TREE);
8962 /* Otherwise it's
8964 friend class C;
8966 where C is already declared or
8968 friend class C<int>;
8970 We don't have to do anything in these cases. */
8972 if (adjust_processing_template_decl)
8973 /* Trick make_friend_class into realizing that the friend
8974 we're adding is a template, not an ordinary class. It's
8975 important that we use make_friend_class since it will
8976 perform some error-checking and output cross-reference
8977 information. */
8978 ++processing_template_decl;
8980 if (friend_type != error_mark_node)
8981 make_friend_class (type, friend_type, /*complain=*/false);
8983 if (adjust_processing_template_decl)
8984 --processing_template_decl;
8986 else
8988 /* Build new DECL_FRIENDLIST. */
8989 tree r;
8991 /* The file and line for this declaration, to
8992 assist in error message reporting. Since we
8993 called push_tinst_level above, we don't need to
8994 restore these. */
8995 input_location = DECL_SOURCE_LOCATION (t);
8997 if (TREE_CODE (t) == TEMPLATE_DECL)
8999 ++processing_template_decl;
9000 push_deferring_access_checks (dk_no_check);
9003 r = tsubst_friend_function (t, args);
9004 add_friend (type, r, /*complain=*/false);
9005 if (TREE_CODE (t) == TEMPLATE_DECL)
9007 pop_deferring_access_checks ();
9008 --processing_template_decl;
9014 if (tree expr = CLASSTYPE_LAMBDA_EXPR (type))
9016 tree decl = lambda_function (type);
9017 if (decl)
9019 instantiate_decl (decl, false, false);
9021 /* We need to instantiate the capture list from the template
9022 after we've instantiated the closure members, but before we
9023 consider adding the conversion op. Also keep any captures
9024 that may have been added during instantiation of the op(). */
9025 tree tmpl_expr = CLASSTYPE_LAMBDA_EXPR (pattern);
9026 tree tmpl_cap
9027 = tsubst_copy_and_build (LAMBDA_EXPR_CAPTURE_LIST (tmpl_expr),
9028 args, tf_warning_or_error, NULL_TREE,
9029 false, false);
9031 LAMBDA_EXPR_CAPTURE_LIST (expr)
9032 = chainon (tmpl_cap, nreverse (LAMBDA_EXPR_CAPTURE_LIST (expr)));
9034 maybe_add_lambda_conv_op (type);
9036 else
9037 gcc_assert (errorcount);
9040 /* Set the file and line number information to whatever is given for
9041 the class itself. This puts error messages involving generated
9042 implicit functions at a predictable point, and the same point
9043 that would be used for non-template classes. */
9044 input_location = DECL_SOURCE_LOCATION (typedecl);
9046 unreverse_member_declarations (type);
9047 finish_struct_1 (type);
9048 TYPE_BEING_DEFINED (type) = 0;
9050 /* We don't instantiate default arguments for member functions. 14.7.1:
9052 The implicit instantiation of a class template specialization causes
9053 the implicit instantiation of the declarations, but not of the
9054 definitions or default arguments, of the class member functions,
9055 member classes, static data members and member templates.... */
9057 /* Some typedefs referenced from within the template code need to be access
9058 checked at template instantiation time, i.e now. These types were
9059 added to the template at parsing time. Let's get those and perform
9060 the access checks then. */
9061 perform_typedefs_access_check (pattern, args);
9062 perform_deferred_access_checks (tf_warning_or_error);
9063 pop_nested_class ();
9064 maximum_field_alignment = saved_maximum_field_alignment;
9065 if (!fn_context)
9066 pop_from_top_level ();
9067 pop_deferring_access_checks ();
9068 pop_tinst_level ();
9070 /* The vtable for a template class can be emitted in any translation
9071 unit in which the class is instantiated. When there is no key
9072 method, however, finish_struct_1 will already have added TYPE to
9073 the keyed_classes list. */
9074 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
9075 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
9077 return type;
9080 /* Wrapper for instantiate_class_template_1. */
9082 tree
9083 instantiate_class_template (tree type)
9085 tree ret;
9086 timevar_push (TV_TEMPLATE_INST);
9087 ret = instantiate_class_template_1 (type);
9088 timevar_pop (TV_TEMPLATE_INST);
9089 return ret;
9092 static tree
9093 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9095 tree r;
9097 if (!t)
9098 r = t;
9099 else if (TYPE_P (t))
9100 r = tsubst (t, args, complain, in_decl);
9101 else
9103 if (!(complain & tf_warning))
9104 ++c_inhibit_evaluation_warnings;
9105 r = tsubst_expr (t, args, complain, in_decl,
9106 /*integral_constant_expression_p=*/true);
9107 if (!(complain & tf_warning))
9108 --c_inhibit_evaluation_warnings;
9109 /* Preserve the raw-reference nature of T. */
9110 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
9111 && REFERENCE_REF_P (r))
9112 r = TREE_OPERAND (r, 0);
9114 return r;
9117 /* Given a function parameter pack TMPL_PARM and some function parameters
9118 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9119 and set *SPEC_P to point at the next point in the list. */
9121 static tree
9122 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
9124 /* Collect all of the extra "packed" parameters into an
9125 argument pack. */
9126 tree parmvec;
9127 tree parmtypevec;
9128 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
9129 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
9130 tree spec_parm = *spec_p;
9131 int i, len;
9133 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
9134 if (tmpl_parm
9135 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
9136 break;
9138 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9139 parmvec = make_tree_vec (len);
9140 parmtypevec = make_tree_vec (len);
9141 spec_parm = *spec_p;
9142 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
9144 TREE_VEC_ELT (parmvec, i) = spec_parm;
9145 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
9148 /* Build the argument packs. */
9149 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
9150 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
9151 TREE_TYPE (argpack) = argtypepack;
9152 *spec_p = spec_parm;
9154 return argpack;
9157 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9158 NONTYPE_ARGUMENT_PACK. */
9160 static tree
9161 make_fnparm_pack (tree spec_parm)
9163 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9166 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9167 pack expansion. */
9169 static bool
9170 argument_pack_element_is_expansion_p (tree arg_pack, int i)
9172 tree vec = ARGUMENT_PACK_ARGS (arg_pack);
9173 if (i >= TREE_VEC_LENGTH (vec))
9174 return false;
9175 return PACK_EXPANSION_P (TREE_VEC_ELT (vec, i));
9179 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9181 static tree
9182 make_argument_pack_select (tree arg_pack, unsigned index)
9184 tree aps = make_node (ARGUMENT_PACK_SELECT);
9186 ARGUMENT_PACK_SELECT_FROM_PACK (aps) = arg_pack;
9187 ARGUMENT_PACK_SELECT_INDEX (aps) = index;
9189 return aps;
9192 /* This is a subroutine of tsubst_pack_expansion.
9194 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9195 mechanism to store the (non complete list of) arguments of the
9196 substitution and return a non substituted pack expansion, in order
9197 to wait for when we have enough arguments to really perform the
9198 substitution. */
9200 static bool
9201 use_pack_expansion_extra_args_p (tree parm_packs,
9202 int arg_pack_len,
9203 bool has_empty_arg)
9205 if (parm_packs == NULL_TREE)
9206 return false;
9208 bool has_expansion_arg = false;
9209 for (int i = 0 ; i < arg_pack_len; ++i)
9211 bool has_non_expansion_arg = false;
9212 for (tree parm_pack = parm_packs;
9213 parm_pack;
9214 parm_pack = TREE_CHAIN (parm_pack))
9216 tree arg = TREE_VALUE (parm_pack);
9218 if (argument_pack_element_is_expansion_p (arg, i))
9219 has_expansion_arg = true;
9220 else
9221 has_non_expansion_arg = true;
9224 /* If one pack has an expansion and another pack has a normal
9225 argument or if one pack has an empty argument another one
9226 hasn't then tsubst_pack_expansion cannot perform the
9227 substitution and need to fall back on the
9228 PACK_EXPANSION_EXTRA mechanism. */
9229 if ((has_expansion_arg && has_non_expansion_arg)
9230 || (has_empty_arg && (has_expansion_arg || has_non_expansion_arg)))
9231 return true;
9233 return false;
9236 /* [temp.variadic]/6 says that:
9238 The instantiation of a pack expansion [...]
9239 produces a list E1,E2, ..., En, where N is the number of elements
9240 in the pack expansion parameters.
9242 This subroutine of tsubst_pack_expansion produces one of these Ei.
9244 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9245 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9246 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9247 INDEX is the index 'i' of the element Ei to produce. ARGS,
9248 COMPLAIN, and IN_DECL are the same parameters as for the
9249 tsubst_pack_expansion function.
9251 The function returns the resulting Ei upon successful completion,
9252 or error_mark_node.
9254 Note that this function possibly modifies the ARGS parameter, so
9255 it's the responsibility of the caller to restore it. */
9257 static tree
9258 gen_elem_of_pack_expansion_instantiation (tree pattern,
9259 tree parm_packs,
9260 unsigned index,
9261 tree args /* This parm gets
9262 modified. */,
9263 tsubst_flags_t complain,
9264 tree in_decl)
9266 tree t;
9267 bool ith_elem_is_expansion = false;
9269 /* For each parameter pack, change the substitution of the parameter
9270 pack to the ith argument in its argument pack, then expand the
9271 pattern. */
9272 for (tree pack = parm_packs; pack; pack = TREE_CHAIN (pack))
9274 tree parm = TREE_PURPOSE (pack);
9275 tree arg_pack = TREE_VALUE (pack);
9276 tree aps; /* instance of ARGUMENT_PACK_SELECT. */
9278 ith_elem_is_expansion |=
9279 argument_pack_element_is_expansion_p (arg_pack, index);
9281 /* Select the Ith argument from the pack. */
9282 if (TREE_CODE (parm) == PARM_DECL)
9284 if (index == 0)
9286 aps = make_argument_pack_select (arg_pack, index);
9287 mark_used (parm);
9288 register_local_specialization (aps, parm);
9290 else
9291 aps = retrieve_local_specialization (parm);
9293 else
9295 int idx, level;
9296 template_parm_level_and_index (parm, &level, &idx);
9298 if (index == 0)
9300 aps = make_argument_pack_select (arg_pack, index);
9301 /* Update the corresponding argument. */
9302 TMPL_ARG (args, level, idx) = aps;
9304 else
9305 /* Re-use the ARGUMENT_PACK_SELECT. */
9306 aps = TMPL_ARG (args, level, idx);
9308 ARGUMENT_PACK_SELECT_INDEX (aps) = index;
9311 /* Substitute into the PATTERN with the (possibly altered)
9312 arguments. */
9313 if (!TYPE_P (pattern))
9314 t = tsubst_expr (pattern, args, complain, in_decl,
9315 /*integral_constant_expression_p=*/false);
9316 else
9317 t = tsubst (pattern, args, complain, in_decl);
9319 /* If the Ith argument pack element is a pack expansion, then
9320 the Ith element resulting from the substituting is going to
9321 be a pack expansion as well. */
9322 if (ith_elem_is_expansion)
9323 t = make_pack_expansion (t);
9325 return t;
9328 /* Substitute ARGS into T, which is an pack expansion
9329 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9330 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9331 (if only a partial substitution could be performed) or
9332 ERROR_MARK_NODE if there was an error. */
9333 tree
9334 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9335 tree in_decl)
9337 tree pattern;
9338 tree pack, packs = NULL_TREE;
9339 bool unsubstituted_packs = false;
9340 int i, len = -1;
9341 tree result;
9342 struct pointer_map_t *saved_local_specializations = NULL;
9343 bool need_local_specializations = false;
9344 int levels;
9346 gcc_assert (PACK_EXPANSION_P (t));
9347 pattern = PACK_EXPANSION_PATTERN (t);
9349 /* Add in any args remembered from an earlier partial instantiation. */
9350 args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args);
9352 levels = TMPL_ARGS_DEPTH (args);
9354 /* Determine the argument packs that will instantiate the parameter
9355 packs used in the expansion expression. While we're at it,
9356 compute the number of arguments to be expanded and make sure it
9357 is consistent. */
9358 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9359 pack = TREE_CHAIN (pack))
9361 tree parm_pack = TREE_VALUE (pack);
9362 tree arg_pack = NULL_TREE;
9363 tree orig_arg = NULL_TREE;
9364 int level = 0;
9366 if (TREE_CODE (parm_pack) == BASES)
9368 if (BASES_DIRECT (parm_pack))
9369 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
9370 args, complain, in_decl, false));
9371 else
9372 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
9373 args, complain, in_decl, false));
9375 if (TREE_CODE (parm_pack) == PARM_DECL)
9377 if (PACK_EXPANSION_LOCAL_P (t))
9378 arg_pack = retrieve_local_specialization (parm_pack);
9379 else
9381 /* We can't rely on local_specializations for a parameter
9382 name used later in a function declaration (such as in a
9383 late-specified return type). Even if it exists, it might
9384 have the wrong value for a recursive call. Just make a
9385 dummy decl, since it's only used for its type. */
9386 arg_pack = tsubst_decl (parm_pack, args, complain);
9387 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
9388 /* Partial instantiation of the parm_pack, we can't build
9389 up an argument pack yet. */
9390 arg_pack = NULL_TREE;
9391 else
9392 arg_pack = make_fnparm_pack (arg_pack);
9393 need_local_specializations = true;
9396 else
9398 int idx;
9399 template_parm_level_and_index (parm_pack, &level, &idx);
9401 if (level <= levels)
9402 arg_pack = TMPL_ARG (args, level, idx);
9405 orig_arg = arg_pack;
9406 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9407 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9409 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9410 /* This can only happen if we forget to expand an argument
9411 pack somewhere else. Just return an error, silently. */
9413 result = make_tree_vec (1);
9414 TREE_VEC_ELT (result, 0) = error_mark_node;
9415 return result;
9418 if (arg_pack)
9420 int my_len =
9421 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9423 /* Don't bother trying to do a partial substitution with
9424 incomplete packs; we'll try again after deduction. */
9425 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9426 return t;
9428 if (len < 0)
9429 len = my_len;
9430 else if (len != my_len)
9432 if (!(complain & tf_error))
9433 /* Fail quietly. */;
9434 else if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9435 error ("mismatched argument pack lengths while expanding "
9436 "%<%T%>",
9437 pattern);
9438 else
9439 error ("mismatched argument pack lengths while expanding "
9440 "%<%E%>",
9441 pattern);
9442 return error_mark_node;
9445 /* Keep track of the parameter packs and their corresponding
9446 argument packs. */
9447 packs = tree_cons (parm_pack, arg_pack, packs);
9448 TREE_TYPE (packs) = orig_arg;
9450 else
9452 /* We can't substitute for this parameter pack. We use a flag as
9453 well as the missing_level counter because function parameter
9454 packs don't have a level. */
9455 unsubstituted_packs = true;
9459 /* We cannot expand this expansion expression, because we don't have
9460 all of the argument packs we need. */
9461 if (use_pack_expansion_extra_args_p (packs, len, unsubstituted_packs))
9463 /* We got some full packs, but we can't substitute them in until we
9464 have values for all the packs. So remember these until then. */
9466 t = make_pack_expansion (pattern);
9467 PACK_EXPANSION_EXTRA_ARGS (t) = args;
9468 return t;
9470 else if (unsubstituted_packs)
9472 /* There were no real arguments, we're just replacing a parameter
9473 pack with another version of itself. Substitute into the
9474 pattern and return a PACK_EXPANSION_*. The caller will need to
9475 deal with that. */
9476 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9477 t = tsubst_expr (pattern, args, complain, in_decl,
9478 /*integral_constant_expression_p=*/false);
9479 else
9480 t = tsubst (pattern, args, complain, in_decl);
9481 t = make_pack_expansion (t);
9482 return t;
9485 gcc_assert (len >= 0);
9487 if (need_local_specializations)
9489 /* We're in a late-specified return type, so create our own local
9490 specializations map; the current map is either NULL or (in the
9491 case of recursive unification) might have bindings that we don't
9492 want to use or alter. */
9493 saved_local_specializations = local_specializations;
9494 local_specializations = pointer_map_create ();
9497 /* For each argument in each argument pack, substitute into the
9498 pattern. */
9499 result = make_tree_vec (len);
9500 for (i = 0; i < len; ++i)
9502 t = gen_elem_of_pack_expansion_instantiation (pattern, packs,
9504 args, complain,
9505 in_decl);
9506 TREE_VEC_ELT (result, i) = t;
9507 if (t == error_mark_node)
9509 result = error_mark_node;
9510 break;
9514 /* Update ARGS to restore the substitution from parameter packs to
9515 their argument packs. */
9516 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9518 tree parm = TREE_PURPOSE (pack);
9520 if (TREE_CODE (parm) == PARM_DECL)
9521 register_local_specialization (TREE_TYPE (pack), parm);
9522 else
9524 int idx, level;
9526 if (TREE_VALUE (pack) == NULL_TREE)
9527 continue;
9529 template_parm_level_and_index (parm, &level, &idx);
9531 /* Update the corresponding argument. */
9532 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9533 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9534 TREE_TYPE (pack);
9535 else
9536 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9540 if (need_local_specializations)
9542 pointer_map_destroy (local_specializations);
9543 local_specializations = saved_local_specializations;
9546 return result;
9549 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9550 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9551 parameter packs; all parms generated from a function parameter pack will
9552 have the same DECL_PARM_INDEX. */
9554 tree
9555 get_pattern_parm (tree parm, tree tmpl)
9557 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9558 tree patparm;
9560 if (DECL_ARTIFICIAL (parm))
9562 for (patparm = DECL_ARGUMENTS (pattern);
9563 patparm; patparm = DECL_CHAIN (patparm))
9564 if (DECL_ARTIFICIAL (patparm)
9565 && DECL_NAME (parm) == DECL_NAME (patparm))
9566 break;
9568 else
9570 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9571 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9572 gcc_assert (DECL_PARM_INDEX (patparm)
9573 == DECL_PARM_INDEX (parm));
9576 return patparm;
9579 /* Substitute ARGS into the vector or list of template arguments T. */
9581 static tree
9582 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9584 tree orig_t = t;
9585 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9586 tree *elts;
9588 if (t == error_mark_node)
9589 return error_mark_node;
9591 len = TREE_VEC_LENGTH (t);
9592 elts = XALLOCAVEC (tree, len);
9594 for (i = 0; i < len; i++)
9596 tree orig_arg = TREE_VEC_ELT (t, i);
9597 tree new_arg;
9599 if (TREE_CODE (orig_arg) == TREE_VEC)
9600 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9601 else if (PACK_EXPANSION_P (orig_arg))
9603 /* Substitute into an expansion expression. */
9604 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9606 if (TREE_CODE (new_arg) == TREE_VEC)
9607 /* Add to the expanded length adjustment the number of
9608 expanded arguments. We subtract one from this
9609 measurement, because the argument pack expression
9610 itself is already counted as 1 in
9611 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9612 the argument pack is empty. */
9613 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9615 else if (ARGUMENT_PACK_P (orig_arg))
9617 /* Substitute into each of the arguments. */
9618 new_arg = TYPE_P (orig_arg)
9619 ? cxx_make_type (TREE_CODE (orig_arg))
9620 : make_node (TREE_CODE (orig_arg));
9622 SET_ARGUMENT_PACK_ARGS (
9623 new_arg,
9624 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9625 args, complain, in_decl));
9627 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9628 new_arg = error_mark_node;
9630 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9631 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9632 complain, in_decl);
9633 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9635 if (TREE_TYPE (new_arg) == error_mark_node)
9636 new_arg = error_mark_node;
9639 else
9640 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9642 if (new_arg == error_mark_node)
9643 return error_mark_node;
9645 elts[i] = new_arg;
9646 if (new_arg != orig_arg)
9647 need_new = 1;
9650 if (!need_new)
9651 return t;
9653 /* Make space for the expanded arguments coming from template
9654 argument packs. */
9655 t = make_tree_vec (len + expanded_len_adjust);
9656 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9657 arguments for a member template.
9658 In that case each TREE_VEC in ORIG_T represents a level of template
9659 arguments, and ORIG_T won't carry any non defaulted argument count.
9660 It will rather be the nested TREE_VECs that will carry one.
9661 In other words, ORIG_T carries a non defaulted argument count only
9662 if it doesn't contain any nested TREE_VEC. */
9663 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9665 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9666 count += expanded_len_adjust;
9667 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9669 for (i = 0, out = 0; i < len; i++)
9671 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9672 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9673 && TREE_CODE (elts[i]) == TREE_VEC)
9675 int idx;
9677 /* Now expand the template argument pack "in place". */
9678 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9679 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9681 else
9683 TREE_VEC_ELT (t, out) = elts[i];
9684 out++;
9688 return t;
9691 /* Return the result of substituting ARGS into the template parameters
9692 given by PARMS. If there are m levels of ARGS and m + n levels of
9693 PARMS, then the result will contain n levels of PARMS. For
9694 example, if PARMS is `template <class T> template <class U>
9695 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9696 result will be `template <int*, double, class V>'. */
9698 static tree
9699 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9701 tree r = NULL_TREE;
9702 tree* new_parms;
9704 /* When substituting into a template, we must set
9705 PROCESSING_TEMPLATE_DECL as the template parameters may be
9706 dependent if they are based on one-another, and the dependency
9707 predicates are short-circuit outside of templates. */
9708 ++processing_template_decl;
9710 for (new_parms = &r;
9711 parms && TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9712 new_parms = &(TREE_CHAIN (*new_parms)),
9713 parms = TREE_CHAIN (parms))
9715 tree new_vec =
9716 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9717 int i;
9719 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9721 tree tuple;
9723 if (parms == error_mark_node)
9724 continue;
9726 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9728 if (tuple == error_mark_node)
9729 continue;
9731 TREE_VEC_ELT (new_vec, i) =
9732 tsubst_template_parm (tuple, args, complain);
9735 *new_parms =
9736 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9737 - TMPL_ARGS_DEPTH (args)),
9738 new_vec, NULL_TREE);
9741 --processing_template_decl;
9743 return r;
9746 /* Return the result of substituting ARGS into one template parameter
9747 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9748 parameter and which TREE_PURPOSE is the default argument of the
9749 template parameter. */
9751 static tree
9752 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9754 tree default_value, parm_decl;
9756 if (args == NULL_TREE
9757 || t == NULL_TREE
9758 || t == error_mark_node)
9759 return t;
9761 gcc_assert (TREE_CODE (t) == TREE_LIST);
9763 default_value = TREE_PURPOSE (t);
9764 parm_decl = TREE_VALUE (t);
9766 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9767 if (TREE_CODE (parm_decl) == PARM_DECL
9768 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9769 parm_decl = error_mark_node;
9770 default_value = tsubst_template_arg (default_value, args,
9771 complain, NULL_TREE);
9773 return build_tree_list (default_value, parm_decl);
9776 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9777 type T. If T is not an aggregate or enumeration type, it is
9778 handled as if by tsubst. IN_DECL is as for tsubst. If
9779 ENTERING_SCOPE is nonzero, T is the context for a template which
9780 we are presently tsubst'ing. Return the substituted value. */
9782 static tree
9783 tsubst_aggr_type (tree t,
9784 tree args,
9785 tsubst_flags_t complain,
9786 tree in_decl,
9787 int entering_scope)
9789 if (t == NULL_TREE)
9790 return NULL_TREE;
9792 switch (TREE_CODE (t))
9794 case RECORD_TYPE:
9795 if (TYPE_PTRMEMFUNC_P (t))
9796 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9798 /* Else fall through. */
9799 case ENUMERAL_TYPE:
9800 case UNION_TYPE:
9801 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9803 tree argvec;
9804 tree context;
9805 tree r;
9806 int saved_unevaluated_operand;
9807 int saved_inhibit_evaluation_warnings;
9809 /* In "sizeof(X<I>)" we need to evaluate "I". */
9810 saved_unevaluated_operand = cp_unevaluated_operand;
9811 cp_unevaluated_operand = 0;
9812 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9813 c_inhibit_evaluation_warnings = 0;
9815 /* First, determine the context for the type we are looking
9816 up. */
9817 context = TYPE_CONTEXT (t);
9818 if (context && TYPE_P (context))
9820 context = tsubst_aggr_type (context, args, complain,
9821 in_decl, /*entering_scope=*/1);
9822 /* If context is a nested class inside a class template,
9823 it may still need to be instantiated (c++/33959). */
9824 context = complete_type (context);
9827 /* Then, figure out what arguments are appropriate for the
9828 type we are trying to find. For example, given:
9830 template <class T> struct S;
9831 template <class T, class U> void f(T, U) { S<U> su; }
9833 and supposing that we are instantiating f<int, double>,
9834 then our ARGS will be {int, double}, but, when looking up
9835 S we only want {double}. */
9836 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9837 complain, in_decl);
9838 if (argvec == error_mark_node)
9839 r = error_mark_node;
9840 else
9842 r = lookup_template_class (t, argvec, in_decl, context,
9843 entering_scope, complain);
9844 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9847 cp_unevaluated_operand = saved_unevaluated_operand;
9848 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9850 return r;
9852 else
9853 /* This is not a template type, so there's nothing to do. */
9854 return t;
9856 default:
9857 return tsubst (t, args, complain, in_decl);
9861 /* Substitute into the default argument ARG (a default argument for
9862 FN), which has the indicated TYPE. */
9864 tree
9865 tsubst_default_argument (tree fn, tree type, tree arg)
9867 tree saved_class_ptr = NULL_TREE;
9868 tree saved_class_ref = NULL_TREE;
9869 int errs = errorcount + sorrycount;
9871 /* This can happen in invalid code. */
9872 if (TREE_CODE (arg) == DEFAULT_ARG)
9873 return arg;
9875 /* This default argument came from a template. Instantiate the
9876 default argument here, not in tsubst. In the case of
9877 something like:
9879 template <class T>
9880 struct S {
9881 static T t();
9882 void f(T = t());
9885 we must be careful to do name lookup in the scope of S<T>,
9886 rather than in the current class. */
9887 push_access_scope (fn);
9888 /* The "this" pointer is not valid in a default argument. */
9889 if (cfun)
9891 saved_class_ptr = current_class_ptr;
9892 cp_function_chain->x_current_class_ptr = NULL_TREE;
9893 saved_class_ref = current_class_ref;
9894 cp_function_chain->x_current_class_ref = NULL_TREE;
9897 push_deferring_access_checks(dk_no_deferred);
9898 /* The default argument expression may cause implicitly defined
9899 member functions to be synthesized, which will result in garbage
9900 collection. We must treat this situation as if we were within
9901 the body of function so as to avoid collecting live data on the
9902 stack. */
9903 ++function_depth;
9904 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9905 tf_warning_or_error, NULL_TREE,
9906 /*integral_constant_expression_p=*/false);
9907 --function_depth;
9908 pop_deferring_access_checks();
9910 /* Restore the "this" pointer. */
9911 if (cfun)
9913 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9914 cp_function_chain->x_current_class_ref = saved_class_ref;
9917 if (errorcount+sorrycount > errs)
9918 inform (input_location,
9919 " when instantiating default argument for call to %D", fn);
9921 /* Make sure the default argument is reasonable. */
9922 arg = check_default_argument (type, arg);
9924 pop_access_scope (fn);
9926 return arg;
9929 /* Substitute into all the default arguments for FN. */
9931 static void
9932 tsubst_default_arguments (tree fn)
9934 tree arg;
9935 tree tmpl_args;
9937 tmpl_args = DECL_TI_ARGS (fn);
9939 /* If this function is not yet instantiated, we certainly don't need
9940 its default arguments. */
9941 if (uses_template_parms (tmpl_args))
9942 return;
9943 /* Don't do this again for clones. */
9944 if (DECL_CLONED_FUNCTION_P (fn))
9945 return;
9947 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9948 arg;
9949 arg = TREE_CHAIN (arg))
9950 if (TREE_PURPOSE (arg))
9951 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9952 TREE_VALUE (arg),
9953 TREE_PURPOSE (arg));
9956 /* Substitute the ARGS into the T, which is a _DECL. Return the
9957 result of the substitution. Issue error and warning messages under
9958 control of COMPLAIN. */
9960 static tree
9961 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9963 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9964 location_t saved_loc;
9965 tree r = NULL_TREE;
9966 tree in_decl = t;
9967 hashval_t hash = 0;
9969 /* Set the filename and linenumber to improve error-reporting. */
9970 saved_loc = input_location;
9971 input_location = DECL_SOURCE_LOCATION (t);
9973 switch (TREE_CODE (t))
9975 case TEMPLATE_DECL:
9977 /* We can get here when processing a member function template,
9978 member class template, or template template parameter. */
9979 tree decl = DECL_TEMPLATE_RESULT (t);
9980 tree spec;
9981 tree tmpl_args;
9982 tree full_args;
9984 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9986 /* Template template parameter is treated here. */
9987 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9988 if (new_type == error_mark_node)
9989 RETURN (error_mark_node);
9990 /* If we get a real template back, return it. This can happen in
9991 the context of most_specialized_class. */
9992 if (TREE_CODE (new_type) == TEMPLATE_DECL)
9993 return new_type;
9995 r = copy_decl (t);
9996 DECL_CHAIN (r) = NULL_TREE;
9997 TREE_TYPE (r) = new_type;
9998 DECL_TEMPLATE_RESULT (r)
9999 = build_decl (DECL_SOURCE_LOCATION (decl),
10000 TYPE_DECL, DECL_NAME (decl), new_type);
10001 DECL_TEMPLATE_PARMS (r)
10002 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10003 complain);
10004 TYPE_NAME (new_type) = r;
10005 break;
10008 /* We might already have an instance of this template.
10009 The ARGS are for the surrounding class type, so the
10010 full args contain the tsubst'd args for the context,
10011 plus the innermost args from the template decl. */
10012 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
10013 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
10014 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
10015 /* Because this is a template, the arguments will still be
10016 dependent, even after substitution. If
10017 PROCESSING_TEMPLATE_DECL is not set, the dependency
10018 predicates will short-circuit. */
10019 ++processing_template_decl;
10020 full_args = tsubst_template_args (tmpl_args, args,
10021 complain, in_decl);
10022 --processing_template_decl;
10023 if (full_args == error_mark_node)
10024 RETURN (error_mark_node);
10026 /* If this is a default template template argument,
10027 tsubst might not have changed anything. */
10028 if (full_args == tmpl_args)
10029 RETURN (t);
10031 hash = hash_tmpl_and_args (t, full_args);
10032 spec = retrieve_specialization (t, full_args, hash);
10033 if (spec != NULL_TREE)
10035 r = spec;
10036 break;
10039 /* Make a new template decl. It will be similar to the
10040 original, but will record the current template arguments.
10041 We also create a new function declaration, which is just
10042 like the old one, but points to this new template, rather
10043 than the old one. */
10044 r = copy_decl (t);
10045 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
10046 DECL_CHAIN (r) = NULL_TREE;
10048 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10050 if (TREE_CODE (decl) == TYPE_DECL
10051 && !TYPE_DECL_ALIAS_P (decl))
10053 tree new_type;
10054 ++processing_template_decl;
10055 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10056 --processing_template_decl;
10057 if (new_type == error_mark_node)
10058 RETURN (error_mark_node);
10060 TREE_TYPE (r) = new_type;
10061 CLASSTYPE_TI_TEMPLATE (new_type) = r;
10062 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
10063 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
10064 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
10066 else
10068 tree new_decl;
10069 ++processing_template_decl;
10070 new_decl = tsubst (decl, args, complain, in_decl);
10071 --processing_template_decl;
10072 if (new_decl == error_mark_node)
10073 RETURN (error_mark_node);
10075 DECL_TEMPLATE_RESULT (r) = new_decl;
10076 DECL_TI_TEMPLATE (new_decl) = r;
10077 TREE_TYPE (r) = TREE_TYPE (new_decl);
10078 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
10079 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
10082 SET_DECL_IMPLICIT_INSTANTIATION (r);
10083 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
10084 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
10086 /* The template parameters for this new template are all the
10087 template parameters for the old template, except the
10088 outermost level of parameters. */
10089 DECL_TEMPLATE_PARMS (r)
10090 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10091 complain);
10093 if (PRIMARY_TEMPLATE_P (t))
10094 DECL_PRIMARY_TEMPLATE (r) = r;
10096 if (TREE_CODE (decl) != TYPE_DECL)
10097 /* Record this non-type partial instantiation. */
10098 register_specialization (r, t,
10099 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
10100 false, hash);
10102 break;
10104 case FUNCTION_DECL:
10106 tree ctx;
10107 tree argvec = NULL_TREE;
10108 tree *friends;
10109 tree gen_tmpl;
10110 tree type;
10111 int member;
10112 int args_depth;
10113 int parms_depth;
10115 /* Nobody should be tsubst'ing into non-template functions. */
10116 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
10118 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
10120 tree spec;
10121 bool dependent_p;
10123 /* If T is not dependent, just return it. We have to
10124 increment PROCESSING_TEMPLATE_DECL because
10125 value_dependent_expression_p assumes that nothing is
10126 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10127 ++processing_template_decl;
10128 dependent_p = value_dependent_expression_p (t);
10129 --processing_template_decl;
10130 if (!dependent_p)
10131 RETURN (t);
10133 /* Calculate the most general template of which R is a
10134 specialization, and the complete set of arguments used to
10135 specialize R. */
10136 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
10137 argvec = tsubst_template_args (DECL_TI_ARGS
10138 (DECL_TEMPLATE_RESULT
10139 (DECL_TI_TEMPLATE (t))),
10140 args, complain, in_decl);
10141 if (argvec == error_mark_node)
10142 RETURN (error_mark_node);
10144 /* Check to see if we already have this specialization. */
10145 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10146 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10148 if (spec)
10150 r = spec;
10151 break;
10154 /* We can see more levels of arguments than parameters if
10155 there was a specialization of a member template, like
10156 this:
10158 template <class T> struct S { template <class U> void f(); }
10159 template <> template <class U> void S<int>::f(U);
10161 Here, we'll be substituting into the specialization,
10162 because that's where we can find the code we actually
10163 want to generate, but we'll have enough arguments for
10164 the most general template.
10166 We also deal with the peculiar case:
10168 template <class T> struct S {
10169 template <class U> friend void f();
10171 template <class U> void f() {}
10172 template S<int>;
10173 template void f<double>();
10175 Here, the ARGS for the instantiation of will be {int,
10176 double}. But, we only need as many ARGS as there are
10177 levels of template parameters in CODE_PATTERN. We are
10178 careful not to get fooled into reducing the ARGS in
10179 situations like:
10181 template <class T> struct S { template <class U> void f(U); }
10182 template <class T> template <> void S<T>::f(int) {}
10184 which we can spot because the pattern will be a
10185 specialization in this case. */
10186 args_depth = TMPL_ARGS_DEPTH (args);
10187 parms_depth =
10188 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
10189 if (args_depth > parms_depth
10190 && !DECL_TEMPLATE_SPECIALIZATION (t))
10191 args = get_innermost_template_args (args, parms_depth);
10193 else
10195 /* This special case arises when we have something like this:
10197 template <class T> struct S {
10198 friend void f<int>(int, double);
10201 Here, the DECL_TI_TEMPLATE for the friend declaration
10202 will be an IDENTIFIER_NODE. We are being called from
10203 tsubst_friend_function, and we want only to create a
10204 new decl (R) with appropriate types so that we can call
10205 determine_specialization. */
10206 gen_tmpl = NULL_TREE;
10209 if (DECL_CLASS_SCOPE_P (t))
10211 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
10212 member = 2;
10213 else
10214 member = 1;
10215 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
10216 complain, t, /*entering_scope=*/1);
10218 else
10220 member = 0;
10221 ctx = DECL_CONTEXT (t);
10223 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10224 if (type == error_mark_node)
10225 RETURN (error_mark_node);
10227 /* If we hit excessive deduction depth, the type is bogus even if
10228 it isn't error_mark_node, so don't build a decl. */
10229 if (excessive_deduction_depth)
10230 RETURN (error_mark_node);
10232 /* We do NOT check for matching decls pushed separately at this
10233 point, as they may not represent instantiations of this
10234 template, and in any case are considered separate under the
10235 discrete model. */
10236 r = copy_decl (t);
10237 DECL_USE_TEMPLATE (r) = 0;
10238 TREE_TYPE (r) = type;
10239 /* Clear out the mangled name and RTL for the instantiation. */
10240 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10241 SET_DECL_RTL (r, NULL);
10242 /* Leave DECL_INITIAL set on deleted instantiations. */
10243 if (!DECL_DELETED_FN (r))
10244 DECL_INITIAL (r) = NULL_TREE;
10245 DECL_CONTEXT (r) = ctx;
10247 if (member && DECL_CONV_FN_P (r))
10248 /* Type-conversion operator. Reconstruct the name, in
10249 case it's the name of one of the template's parameters. */
10250 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
10252 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
10253 complain, t);
10254 DECL_RESULT (r) = NULL_TREE;
10256 TREE_STATIC (r) = 0;
10257 TREE_PUBLIC (r) = TREE_PUBLIC (t);
10258 DECL_EXTERNAL (r) = 1;
10259 /* If this is an instantiation of a function with internal
10260 linkage, we already know what object file linkage will be
10261 assigned to the instantiation. */
10262 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
10263 DECL_DEFER_OUTPUT (r) = 0;
10264 DECL_CHAIN (r) = NULL_TREE;
10265 DECL_PENDING_INLINE_INFO (r) = 0;
10266 DECL_PENDING_INLINE_P (r) = 0;
10267 DECL_SAVED_TREE (r) = NULL_TREE;
10268 DECL_STRUCT_FUNCTION (r) = NULL;
10269 TREE_USED (r) = 0;
10270 /* We'll re-clone as appropriate in instantiate_template. */
10271 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10273 /* If we aren't complaining now, return on error before we register
10274 the specialization so that we'll complain eventually. */
10275 if ((complain & tf_error) == 0
10276 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10277 && !grok_op_properties (r, /*complain=*/false))
10278 RETURN (error_mark_node);
10280 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10281 this in the special friend case mentioned above where
10282 GEN_TMPL is NULL. */
10283 if (gen_tmpl)
10285 DECL_TEMPLATE_INFO (r)
10286 = build_template_info (gen_tmpl, argvec);
10287 SET_DECL_IMPLICIT_INSTANTIATION (r);
10289 tree new_r
10290 = register_specialization (r, gen_tmpl, argvec, false, hash);
10291 if (new_r != r)
10292 /* We instantiated this while substituting into
10293 the type earlier (template/friend54.C). */
10294 RETURN (new_r);
10296 /* We're not supposed to instantiate default arguments
10297 until they are called, for a template. But, for a
10298 declaration like:
10300 template <class T> void f ()
10301 { extern void g(int i = T()); }
10303 we should do the substitution when the template is
10304 instantiated. We handle the member function case in
10305 instantiate_class_template since the default arguments
10306 might refer to other members of the class. */
10307 if (!member
10308 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10309 && !uses_template_parms (argvec))
10310 tsubst_default_arguments (r);
10312 else
10313 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10315 /* Copy the list of befriending classes. */
10316 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10317 *friends;
10318 friends = &TREE_CHAIN (*friends))
10320 *friends = copy_node (*friends);
10321 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10322 args, complain,
10323 in_decl);
10326 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10328 maybe_retrofit_in_chrg (r);
10329 if (DECL_CONSTRUCTOR_P (r))
10330 grok_ctor_properties (ctx, r);
10331 if (DECL_INHERITED_CTOR_BASE (r))
10332 deduce_inheriting_ctor (r);
10333 /* If this is an instantiation of a member template, clone it.
10334 If it isn't, that'll be handled by
10335 clone_constructors_and_destructors. */
10336 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10337 clone_function_decl (r, /*update_method_vec_p=*/0);
10339 else if ((complain & tf_error) != 0
10340 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10341 && !grok_op_properties (r, /*complain=*/true))
10342 RETURN (error_mark_node);
10344 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10345 SET_DECL_FRIEND_CONTEXT (r,
10346 tsubst (DECL_FRIEND_CONTEXT (t),
10347 args, complain, in_decl));
10349 /* Possibly limit visibility based on template args. */
10350 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10351 if (DECL_VISIBILITY_SPECIFIED (t))
10353 DECL_VISIBILITY_SPECIFIED (r) = 0;
10354 DECL_ATTRIBUTES (r)
10355 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10357 determine_visibility (r);
10358 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10359 && !processing_template_decl)
10360 defaulted_late_check (r);
10362 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10363 args, complain, in_decl);
10365 break;
10367 case PARM_DECL:
10369 tree type = NULL_TREE;
10370 int i, len = 1;
10371 tree expanded_types = NULL_TREE;
10372 tree prev_r = NULL_TREE;
10373 tree first_r = NULL_TREE;
10375 if (FUNCTION_PARAMETER_PACK_P (t))
10377 /* If there is a local specialization that isn't a
10378 parameter pack, it means that we're doing a "simple"
10379 substitution from inside tsubst_pack_expansion. Just
10380 return the local specialization (which will be a single
10381 parm). */
10382 tree spec = retrieve_local_specialization (t);
10383 if (spec
10384 && TREE_CODE (spec) == PARM_DECL
10385 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10386 RETURN (spec);
10388 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10389 the parameters in this function parameter pack. */
10390 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10391 complain, in_decl);
10392 if (TREE_CODE (expanded_types) == TREE_VEC)
10394 len = TREE_VEC_LENGTH (expanded_types);
10396 /* Zero-length parameter packs are boring. Just substitute
10397 into the chain. */
10398 if (len == 0)
10399 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10400 TREE_CHAIN (t)));
10402 else
10404 /* All we did was update the type. Make a note of that. */
10405 type = expanded_types;
10406 expanded_types = NULL_TREE;
10410 /* Loop through all of the parameter's we'll build. When T is
10411 a function parameter pack, LEN is the number of expanded
10412 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10413 r = NULL_TREE;
10414 for (i = 0; i < len; ++i)
10416 prev_r = r;
10417 r = copy_node (t);
10418 if (DECL_TEMPLATE_PARM_P (t))
10419 SET_DECL_TEMPLATE_PARM_P (r);
10421 if (expanded_types)
10422 /* We're on the Ith parameter of the function parameter
10423 pack. */
10425 /* An argument of a function parameter pack is not a parameter
10426 pack. */
10427 FUNCTION_PARAMETER_PACK_P (r) = false;
10429 /* Get the Ith type. */
10430 type = TREE_VEC_ELT (expanded_types, i);
10432 /* Rename the parameter to include the index. */
10433 DECL_NAME (r)
10434 = make_ith_pack_parameter_name (DECL_NAME (r), i);
10436 else if (!type)
10437 /* We're dealing with a normal parameter. */
10438 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10440 type = type_decays_to (type);
10441 TREE_TYPE (r) = type;
10442 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10444 if (DECL_INITIAL (r))
10446 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10447 DECL_INITIAL (r) = TREE_TYPE (r);
10448 else
10449 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10450 complain, in_decl);
10453 DECL_CONTEXT (r) = NULL_TREE;
10455 if (!DECL_TEMPLATE_PARM_P (r))
10456 DECL_ARG_TYPE (r) = type_passed_as (type);
10458 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10459 args, complain, in_decl);
10461 /* Keep track of the first new parameter we
10462 generate. That's what will be returned to the
10463 caller. */
10464 if (!first_r)
10465 first_r = r;
10467 /* Build a proper chain of parameters when substituting
10468 into a function parameter pack. */
10469 if (prev_r)
10470 DECL_CHAIN (prev_r) = r;
10473 /* If cp_unevaluated_operand is set, we're just looking for a
10474 single dummy parameter, so don't keep going. */
10475 if (DECL_CHAIN (t) && !cp_unevaluated_operand)
10476 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10477 complain, DECL_CHAIN (t));
10479 /* FIRST_R contains the start of the chain we've built. */
10480 r = first_r;
10482 break;
10484 case FIELD_DECL:
10486 tree type;
10488 r = copy_decl (t);
10489 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10490 if (type == error_mark_node)
10491 RETURN (error_mark_node);
10492 TREE_TYPE (r) = type;
10493 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10495 if (DECL_C_BIT_FIELD (r))
10496 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10497 non-bit-fields DECL_INITIAL is a non-static data member
10498 initializer, which gets deferred instantiation. */
10499 DECL_INITIAL (r)
10500 = tsubst_expr (DECL_INITIAL (t), args,
10501 complain, in_decl,
10502 /*integral_constant_expression_p=*/true);
10503 else if (DECL_INITIAL (t))
10505 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10506 NSDMI in perform_member_init. Still set DECL_INITIAL
10507 so that we know there is one. */
10508 DECL_INITIAL (r) = void_zero_node;
10509 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
10510 retrofit_lang_decl (r);
10511 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10513 /* We don't have to set DECL_CONTEXT here; it is set by
10514 finish_member_declaration. */
10515 DECL_CHAIN (r) = NULL_TREE;
10516 if (VOID_TYPE_P (type))
10517 error ("instantiation of %q+D as type %qT", r, type);
10519 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10520 args, complain, in_decl);
10522 break;
10524 case USING_DECL:
10525 /* We reach here only for member using decls. We also need to check
10526 uses_template_parms because DECL_DEPENDENT_P is not set for a
10527 using-declaration that designates a member of the current
10528 instantiation (c++/53549). */
10529 if (DECL_DEPENDENT_P (t)
10530 || uses_template_parms (USING_DECL_SCOPE (t)))
10532 tree inst_scope = tsubst_copy (USING_DECL_SCOPE (t), args,
10533 complain, in_decl);
10534 tree name = tsubst_copy (DECL_NAME (t), args, complain, in_decl);
10535 r = do_class_using_decl (inst_scope, name);
10536 if (!r)
10537 r = error_mark_node;
10538 else
10540 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10541 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10544 else
10546 r = copy_node (t);
10547 DECL_CHAIN (r) = NULL_TREE;
10549 break;
10551 case TYPE_DECL:
10552 case VAR_DECL:
10554 tree argvec = NULL_TREE;
10555 tree gen_tmpl = NULL_TREE;
10556 tree spec;
10557 tree tmpl = NULL_TREE;
10558 tree ctx;
10559 tree type = NULL_TREE;
10560 bool local_p;
10562 if (TREE_CODE (t) == TYPE_DECL
10563 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
10565 /* If this is the canonical decl, we don't have to
10566 mess with instantiations, and often we can't (for
10567 typename, template type parms and such). Note that
10568 TYPE_NAME is not correct for the above test if
10569 we've copied the type for a typedef. */
10570 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10571 if (type == error_mark_node)
10572 RETURN (error_mark_node);
10573 r = TYPE_NAME (type);
10574 break;
10577 /* Check to see if we already have the specialization we
10578 need. */
10579 spec = NULL_TREE;
10580 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
10582 /* T is a static data member or namespace-scope entity.
10583 We have to substitute into namespace-scope variables
10584 (even though such entities are never templates) because
10585 of cases like:
10587 template <class T> void f() { extern T t; }
10589 where the entity referenced is not known until
10590 instantiation time. */
10591 local_p = false;
10592 ctx = DECL_CONTEXT (t);
10593 if (DECL_CLASS_SCOPE_P (t))
10595 ctx = tsubst_aggr_type (ctx, args,
10596 complain,
10597 in_decl, /*entering_scope=*/1);
10598 /* If CTX is unchanged, then T is in fact the
10599 specialization we want. That situation occurs when
10600 referencing a static data member within in its own
10601 class. We can use pointer equality, rather than
10602 same_type_p, because DECL_CONTEXT is always
10603 canonical... */
10604 if (ctx == DECL_CONTEXT (t)
10605 && (TREE_CODE (t) != TYPE_DECL
10606 /* ... unless T is a member template; in which
10607 case our caller can be willing to create a
10608 specialization of that template represented
10609 by T. */
10610 || !(DECL_TI_TEMPLATE (t)
10611 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t)))))
10612 spec = t;
10615 if (!spec)
10617 tmpl = DECL_TI_TEMPLATE (t);
10618 gen_tmpl = most_general_template (tmpl);
10619 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10620 if (argvec == error_mark_node)
10621 RETURN (error_mark_node);
10622 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10623 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10626 else
10628 /* A local variable. */
10629 local_p = true;
10630 /* Subsequent calls to pushdecl will fill this in. */
10631 ctx = NULL_TREE;
10632 spec = retrieve_local_specialization (t);
10634 /* If we already have the specialization we need, there is
10635 nothing more to do. */
10636 if (spec)
10638 r = spec;
10639 break;
10642 if (TREE_CODE (t) == VAR_DECL && DECL_ANON_UNION_VAR_P (t))
10644 /* Just use name lookup to find a member alias for an anonymous
10645 union, but then add it to the hash table. */
10646 r = lookup_name (DECL_NAME (t));
10647 gcc_assert (DECL_ANON_UNION_VAR_P (r));
10648 register_local_specialization (r, t);
10649 break;
10652 /* Create a new node for the specialization we need. */
10653 r = copy_decl (t);
10654 if (type == NULL_TREE)
10656 if (is_typedef_decl (t))
10657 type = DECL_ORIGINAL_TYPE (t);
10658 else
10659 type = TREE_TYPE (t);
10660 if (TREE_CODE (t) == VAR_DECL
10661 && VAR_HAD_UNKNOWN_BOUND (t)
10662 && type != error_mark_node)
10663 type = strip_array_domain (type);
10664 type = tsubst (type, args, complain, in_decl);
10666 if (TREE_CODE (r) == VAR_DECL)
10668 /* Even if the original location is out of scope, the
10669 newly substituted one is not. */
10670 DECL_DEAD_FOR_LOCAL (r) = 0;
10671 DECL_INITIALIZED_P (r) = 0;
10672 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10673 if (type == error_mark_node)
10674 RETURN (error_mark_node);
10675 if (TREE_CODE (type) == FUNCTION_TYPE)
10677 /* It may seem that this case cannot occur, since:
10679 typedef void f();
10680 void g() { f x; }
10682 declares a function, not a variable. However:
10684 typedef void f();
10685 template <typename T> void g() { T t; }
10686 template void g<f>();
10688 is an attempt to declare a variable with function
10689 type. */
10690 error ("variable %qD has function type",
10691 /* R is not yet sufficiently initialized, so we
10692 just use its name. */
10693 DECL_NAME (r));
10694 RETURN (error_mark_node);
10696 type = complete_type (type);
10697 /* Wait until cp_finish_decl to set this again, to handle
10698 circular dependency (template/instantiate6.C). */
10699 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10700 type = check_var_type (DECL_NAME (r), type);
10702 if (DECL_HAS_VALUE_EXPR_P (t))
10704 tree ve = DECL_VALUE_EXPR (t);
10705 ve = tsubst_expr (ve, args, complain, in_decl,
10706 /*constant_expression_p=*/false);
10707 if (REFERENCE_REF_P (ve))
10709 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10710 ve = TREE_OPERAND (ve, 0);
10712 SET_DECL_VALUE_EXPR (r, ve);
10715 else if (DECL_SELF_REFERENCE_P (t))
10716 SET_DECL_SELF_REFERENCE_P (r);
10717 TREE_TYPE (r) = type;
10718 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10719 DECL_CONTEXT (r) = ctx;
10720 /* Clear out the mangled name and RTL for the instantiation. */
10721 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10722 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10723 SET_DECL_RTL (r, NULL);
10724 /* The initializer must not be expanded until it is required;
10725 see [temp.inst]. */
10726 DECL_INITIAL (r) = NULL_TREE;
10727 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10728 SET_DECL_RTL (r, NULL);
10729 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10730 if (TREE_CODE (r) == VAR_DECL)
10732 /* Possibly limit visibility based on template args. */
10733 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10734 if (DECL_VISIBILITY_SPECIFIED (t))
10736 DECL_VISIBILITY_SPECIFIED (r) = 0;
10737 DECL_ATTRIBUTES (r)
10738 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10740 determine_visibility (r);
10743 if (!local_p)
10745 /* A static data member declaration is always marked
10746 external when it is declared in-class, even if an
10747 initializer is present. We mimic the non-template
10748 processing here. */
10749 DECL_EXTERNAL (r) = 1;
10751 register_specialization (r, gen_tmpl, argvec, false, hash);
10752 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10753 SET_DECL_IMPLICIT_INSTANTIATION (r);
10755 else if (cp_unevaluated_operand)
10757 /* We're substituting this var in a decltype outside of its
10758 scope, such as for a lambda return type. Don't add it to
10759 local_specializations, do perform auto deduction. */
10760 tree auto_node = type_uses_auto (type);
10761 if (auto_node)
10763 tree init
10764 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10765 /*constant_expression_p=*/false);
10766 init = resolve_nondeduced_context (init);
10767 TREE_TYPE (r) = type
10768 = do_auto_deduction (type, init, auto_node);
10771 else
10772 register_local_specialization (r, t);
10774 DECL_CHAIN (r) = NULL_TREE;
10776 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10777 /*flags=*/0,
10778 args, complain, in_decl);
10780 /* Preserve a typedef that names a type. */
10781 if (is_typedef_decl (r))
10783 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10784 set_underlying_type (r);
10787 layout_decl (r, 0);
10789 break;
10791 default:
10792 gcc_unreachable ();
10794 #undef RETURN
10796 out:
10797 /* Restore the file and line information. */
10798 input_location = saved_loc;
10800 return r;
10803 /* Substitute into the ARG_TYPES of a function type.
10804 If END is a TREE_CHAIN, leave it and any following types
10805 un-substituted. */
10807 static tree
10808 tsubst_arg_types (tree arg_types,
10809 tree args,
10810 tree end,
10811 tsubst_flags_t complain,
10812 tree in_decl)
10814 tree remaining_arg_types;
10815 tree type = NULL_TREE;
10816 int i = 1;
10817 tree expanded_args = NULL_TREE;
10818 tree default_arg;
10820 if (!arg_types || arg_types == void_list_node || arg_types == end)
10821 return arg_types;
10823 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10824 args, end, complain, in_decl);
10825 if (remaining_arg_types == error_mark_node)
10826 return error_mark_node;
10828 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10830 /* For a pack expansion, perform substitution on the
10831 entire expression. Later on, we'll handle the arguments
10832 one-by-one. */
10833 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10834 args, complain, in_decl);
10836 if (TREE_CODE (expanded_args) == TREE_VEC)
10837 /* So that we'll spin through the parameters, one by one. */
10838 i = TREE_VEC_LENGTH (expanded_args);
10839 else
10841 /* We only partially substituted into the parameter
10842 pack. Our type is TYPE_PACK_EXPANSION. */
10843 type = expanded_args;
10844 expanded_args = NULL_TREE;
10848 while (i > 0) {
10849 --i;
10851 if (expanded_args)
10852 type = TREE_VEC_ELT (expanded_args, i);
10853 else if (!type)
10854 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10856 if (type == error_mark_node)
10857 return error_mark_node;
10858 if (VOID_TYPE_P (type))
10860 if (complain & tf_error)
10862 error ("invalid parameter type %qT", type);
10863 if (in_decl)
10864 error ("in declaration %q+D", in_decl);
10866 return error_mark_node;
10868 /* DR 657. */
10869 if (abstract_virtuals_error_sfinae (ACU_PARM, type, complain))
10870 return error_mark_node;
10872 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10873 top-level qualifiers as required. */
10874 type = cv_unqualified (type_decays_to (type));
10876 /* We do not substitute into default arguments here. The standard
10877 mandates that they be instantiated only when needed, which is
10878 done in build_over_call. */
10879 default_arg = TREE_PURPOSE (arg_types);
10881 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10883 /* We've instantiated a template before its default arguments
10884 have been parsed. This can happen for a nested template
10885 class, and is not an error unless we require the default
10886 argument in a call of this function. */
10887 remaining_arg_types =
10888 tree_cons (default_arg, type, remaining_arg_types);
10889 vec_safe_push (DEFARG_INSTANTIATIONS(default_arg), remaining_arg_types);
10891 else
10892 remaining_arg_types =
10893 hash_tree_cons (default_arg, type, remaining_arg_types);
10896 return remaining_arg_types;
10899 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10900 *not* handle the exception-specification for FNTYPE, because the
10901 initial substitution of explicitly provided template parameters
10902 during argument deduction forbids substitution into the
10903 exception-specification:
10905 [temp.deduct]
10907 All references in the function type of the function template to the
10908 corresponding template parameters are replaced by the specified tem-
10909 plate argument values. If a substitution in a template parameter or
10910 in the function type of the function template results in an invalid
10911 type, type deduction fails. [Note: The equivalent substitution in
10912 exception specifications is done only when the function is instanti-
10913 ated, at which point a program is ill-formed if the substitution
10914 results in an invalid type.] */
10916 static tree
10917 tsubst_function_type (tree t,
10918 tree args,
10919 tsubst_flags_t complain,
10920 tree in_decl)
10922 tree return_type;
10923 tree arg_types;
10924 tree fntype;
10926 /* The TYPE_CONTEXT is not used for function/method types. */
10927 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10929 /* Substitute the return type. */
10930 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10931 if (return_type == error_mark_node)
10932 return error_mark_node;
10933 /* DR 486 clarifies that creation of a function type with an
10934 invalid return type is a deduction failure. */
10935 if (TREE_CODE (return_type) == ARRAY_TYPE
10936 || TREE_CODE (return_type) == FUNCTION_TYPE)
10938 if (complain & tf_error)
10940 if (TREE_CODE (return_type) == ARRAY_TYPE)
10941 error ("function returning an array");
10942 else
10943 error ("function returning a function");
10945 return error_mark_node;
10947 /* And DR 657. */
10948 if (abstract_virtuals_error_sfinae (ACU_RETURN, return_type, complain))
10949 return error_mark_node;
10951 /* Substitute the argument types. */
10952 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, NULL_TREE,
10953 complain, in_decl);
10954 if (arg_types == error_mark_node)
10955 return error_mark_node;
10957 /* Construct a new type node and return it. */
10958 if (TREE_CODE (t) == FUNCTION_TYPE)
10960 fntype = build_function_type (return_type, arg_types);
10961 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10963 else
10965 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10966 if (! MAYBE_CLASS_TYPE_P (r))
10968 /* [temp.deduct]
10970 Type deduction may fail for any of the following
10971 reasons:
10973 -- Attempting to create "pointer to member of T" when T
10974 is not a class type. */
10975 if (complain & tf_error)
10976 error ("creating pointer to member function of non-class type %qT",
10978 return error_mark_node;
10981 fntype = build_method_type_directly (r, return_type,
10982 TREE_CHAIN (arg_types));
10984 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10986 return fntype;
10989 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10990 ARGS into that specification, and return the substituted
10991 specification. If there is no specification, return NULL_TREE. */
10993 static tree
10994 tsubst_exception_specification (tree fntype,
10995 tree args,
10996 tsubst_flags_t complain,
10997 tree in_decl,
10998 bool defer_ok)
11000 tree specs;
11001 tree new_specs;
11003 specs = TYPE_RAISES_EXCEPTIONS (fntype);
11004 new_specs = NULL_TREE;
11005 if (specs && TREE_PURPOSE (specs))
11007 /* A noexcept-specifier. */
11008 tree expr = TREE_PURPOSE (specs);
11009 if (TREE_CODE (expr) == INTEGER_CST)
11010 new_specs = expr;
11011 else if (defer_ok)
11013 /* Defer instantiation of noexcept-specifiers to avoid
11014 excessive instantiations (c++/49107). */
11015 new_specs = make_node (DEFERRED_NOEXCEPT);
11016 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
11018 /* We already partially instantiated this member template,
11019 so combine the new args with the old. */
11020 DEFERRED_NOEXCEPT_PATTERN (new_specs)
11021 = DEFERRED_NOEXCEPT_PATTERN (expr);
11022 DEFERRED_NOEXCEPT_ARGS (new_specs)
11023 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
11025 else
11027 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
11028 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
11031 else
11032 new_specs = tsubst_copy_and_build
11033 (expr, args, complain, in_decl, /*function_p=*/false,
11034 /*integral_constant_expression_p=*/true);
11035 new_specs = build_noexcept_spec (new_specs, complain);
11037 else if (specs)
11039 if (! TREE_VALUE (specs))
11040 new_specs = specs;
11041 else
11042 while (specs)
11044 tree spec;
11045 int i, len = 1;
11046 tree expanded_specs = NULL_TREE;
11048 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
11050 /* Expand the pack expansion type. */
11051 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
11052 args, complain,
11053 in_decl);
11055 if (expanded_specs == error_mark_node)
11056 return error_mark_node;
11057 else if (TREE_CODE (expanded_specs) == TREE_VEC)
11058 len = TREE_VEC_LENGTH (expanded_specs);
11059 else
11061 /* We're substituting into a member template, so
11062 we got a TYPE_PACK_EXPANSION back. Add that
11063 expansion and move on. */
11064 gcc_assert (TREE_CODE (expanded_specs)
11065 == TYPE_PACK_EXPANSION);
11066 new_specs = add_exception_specifier (new_specs,
11067 expanded_specs,
11068 complain);
11069 specs = TREE_CHAIN (specs);
11070 continue;
11074 for (i = 0; i < len; ++i)
11076 if (expanded_specs)
11077 spec = TREE_VEC_ELT (expanded_specs, i);
11078 else
11079 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
11080 if (spec == error_mark_node)
11081 return spec;
11082 new_specs = add_exception_specifier (new_specs, spec,
11083 complain);
11086 specs = TREE_CHAIN (specs);
11089 return new_specs;
11092 /* Take the tree structure T and replace template parameters used
11093 therein with the argument vector ARGS. IN_DECL is an associated
11094 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11095 Issue error and warning messages under control of COMPLAIN. Note
11096 that we must be relatively non-tolerant of extensions here, in
11097 order to preserve conformance; if we allow substitutions that
11098 should not be allowed, we may allow argument deductions that should
11099 not succeed, and therefore report ambiguous overload situations
11100 where there are none. In theory, we could allow the substitution,
11101 but indicate that it should have failed, and allow our caller to
11102 make sure that the right thing happens, but we don't try to do this
11103 yet.
11105 This function is used for dealing with types, decls and the like;
11106 for expressions, use tsubst_expr or tsubst_copy. */
11108 tree
11109 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11111 enum tree_code code;
11112 tree type, r = NULL_TREE;
11114 if (t == NULL_TREE || t == error_mark_node
11115 || t == integer_type_node
11116 || t == void_type_node
11117 || t == char_type_node
11118 || t == unknown_type_node
11119 || TREE_CODE (t) == NAMESPACE_DECL
11120 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
11121 return t;
11123 if (DECL_P (t))
11124 return tsubst_decl (t, args, complain);
11126 if (args == NULL_TREE)
11127 return t;
11129 code = TREE_CODE (t);
11131 if (code == IDENTIFIER_NODE)
11132 type = IDENTIFIER_TYPE_VALUE (t);
11133 else
11134 type = TREE_TYPE (t);
11136 gcc_assert (type != unknown_type_node);
11138 /* Reuse typedefs. We need to do this to handle dependent attributes,
11139 such as attribute aligned. */
11140 if (TYPE_P (t)
11141 && typedef_variant_p (t))
11143 tree decl = TYPE_NAME (t);
11145 if (alias_template_specialization_p (t))
11147 /* DECL represents an alias template and we want to
11148 instantiate it. */
11149 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11150 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11151 r = instantiate_alias_template (tmpl, gen_args, complain);
11153 else if (DECL_CLASS_SCOPE_P (decl)
11154 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
11155 && uses_template_parms (DECL_CONTEXT (decl)))
11157 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11158 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11159 r = retrieve_specialization (tmpl, gen_args, 0);
11161 else if (DECL_FUNCTION_SCOPE_P (decl)
11162 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
11163 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
11164 r = retrieve_local_specialization (decl);
11165 else
11166 /* The typedef is from a non-template context. */
11167 return t;
11169 if (r)
11171 r = TREE_TYPE (r);
11172 r = cp_build_qualified_type_real
11173 (r, cp_type_quals (t) | cp_type_quals (r),
11174 complain | tf_ignore_bad_quals);
11175 return r;
11177 else
11179 /* We don't have an instantiation yet, so drop the typedef. */
11180 int quals = cp_type_quals (t);
11181 t = DECL_ORIGINAL_TYPE (decl);
11182 t = cp_build_qualified_type_real (t, quals,
11183 complain | tf_ignore_bad_quals);
11187 if (type
11188 && code != TYPENAME_TYPE
11189 && code != TEMPLATE_TYPE_PARM
11190 && code != IDENTIFIER_NODE
11191 && code != FUNCTION_TYPE
11192 && code != METHOD_TYPE)
11193 type = tsubst (type, args, complain, in_decl);
11194 if (type == error_mark_node)
11195 return error_mark_node;
11197 switch (code)
11199 case RECORD_TYPE:
11200 case UNION_TYPE:
11201 case ENUMERAL_TYPE:
11202 return tsubst_aggr_type (t, args, complain, in_decl,
11203 /*entering_scope=*/0);
11205 case ERROR_MARK:
11206 case IDENTIFIER_NODE:
11207 case VOID_TYPE:
11208 case REAL_TYPE:
11209 case COMPLEX_TYPE:
11210 case VECTOR_TYPE:
11211 case BOOLEAN_TYPE:
11212 case NULLPTR_TYPE:
11213 case LANG_TYPE:
11214 return t;
11216 case INTEGER_TYPE:
11217 if (t == integer_type_node)
11218 return t;
11220 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
11221 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
11222 return t;
11225 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
11227 max = tsubst_expr (omax, args, complain, in_decl,
11228 /*integral_constant_expression_p=*/false);
11230 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11231 needed. */
11232 if (TREE_CODE (max) == NOP_EXPR
11233 && TREE_SIDE_EFFECTS (omax)
11234 && !TREE_TYPE (max))
11235 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
11237 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11238 with TREE_SIDE_EFFECTS that indicates this is not an integral
11239 constant expression. */
11240 if (processing_template_decl
11241 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
11243 gcc_assert (TREE_CODE (max) == NOP_EXPR);
11244 TREE_SIDE_EFFECTS (max) = 1;
11247 return compute_array_index_type (NULL_TREE, max, complain);
11250 case TEMPLATE_TYPE_PARM:
11251 case TEMPLATE_TEMPLATE_PARM:
11252 case BOUND_TEMPLATE_TEMPLATE_PARM:
11253 case TEMPLATE_PARM_INDEX:
11255 int idx;
11256 int level;
11257 int levels;
11258 tree arg = NULL_TREE;
11260 r = NULL_TREE;
11262 gcc_assert (TREE_VEC_LENGTH (args) > 0);
11263 template_parm_level_and_index (t, &level, &idx);
11265 levels = TMPL_ARGS_DEPTH (args);
11266 if (level <= levels)
11268 arg = TMPL_ARG (args, level, idx);
11270 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
11272 /* See through ARGUMENT_PACK_SELECT arguments. */
11273 arg = ARGUMENT_PACK_SELECT_ARG (arg);
11274 /* If the selected argument is an expansion E, that most
11275 likely means we were called from
11276 gen_elem_of_pack_expansion_instantiation during the
11277 substituting of pack an argument pack (which Ith
11278 element is a pack expansion, where I is
11279 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11280 In this case, the Ith element resulting from this
11281 substituting is going to be a pack expansion, which
11282 pattern is the pattern of E. Let's return the
11283 pattern of E, and
11284 gen_elem_of_pack_expansion_instantiation will
11285 build the resulting pack expansion from it. */
11286 if (PACK_EXPANSION_P (arg))
11287 arg = PACK_EXPANSION_PATTERN (arg);
11291 if (arg == error_mark_node)
11292 return error_mark_node;
11293 else if (arg != NULL_TREE)
11295 if (ARGUMENT_PACK_P (arg))
11296 /* If ARG is an argument pack, we don't actually want to
11297 perform a substitution here, because substitutions
11298 for argument packs are only done
11299 element-by-element. We can get to this point when
11300 substituting the type of a non-type template
11301 parameter pack, when that type actually contains
11302 template parameter packs from an outer template, e.g.,
11304 template<typename... Types> struct A {
11305 template<Types... Values> struct B { };
11306 }; */
11307 return t;
11309 if (code == TEMPLATE_TYPE_PARM)
11311 int quals;
11312 gcc_assert (TYPE_P (arg));
11314 quals = cp_type_quals (arg) | cp_type_quals (t);
11316 return cp_build_qualified_type_real
11317 (arg, quals, complain | tf_ignore_bad_quals);
11319 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11321 /* We are processing a type constructed from a
11322 template template parameter. */
11323 tree argvec = tsubst (TYPE_TI_ARGS (t),
11324 args, complain, in_decl);
11325 if (argvec == error_mark_node)
11326 return error_mark_node;
11328 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
11329 || TREE_CODE (arg) == TEMPLATE_DECL
11330 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
11332 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
11333 /* Consider this code:
11335 template <template <class> class Template>
11336 struct Internal {
11337 template <class Arg> using Bind = Template<Arg>;
11340 template <template <class> class Template, class Arg>
11341 using Instantiate = Template<Arg>; //#0
11343 template <template <class> class Template,
11344 class Argument>
11345 using Bind =
11346 Instantiate<Internal<Template>::template Bind,
11347 Argument>; //#1
11349 When #1 is parsed, the
11350 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11351 parameter `Template' in #0 matches the
11352 UNBOUND_CLASS_TEMPLATE representing the argument
11353 `Internal<Template>::template Bind'; We then want
11354 to assemble the type `Bind<Argument>' that can't
11355 be fully created right now, because
11356 `Internal<Template>' not being complete, the Bind
11357 template cannot be looked up in that context. So
11358 we need to "store" `Bind<Argument>' for later
11359 when the context of Bind becomes complete. Let's
11360 store that in a TYPENAME_TYPE. */
11361 return make_typename_type (TYPE_CONTEXT (arg),
11362 build_nt (TEMPLATE_ID_EXPR,
11363 TYPE_IDENTIFIER (arg),
11364 argvec),
11365 typename_type,
11366 complain);
11368 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11369 are resolving nested-types in the signature of a
11370 member function templates. Otherwise ARG is a
11371 TEMPLATE_DECL and is the real template to be
11372 instantiated. */
11373 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11374 arg = TYPE_NAME (arg);
11376 r = lookup_template_class (arg,
11377 argvec, in_decl,
11378 DECL_CONTEXT (arg),
11379 /*entering_scope=*/0,
11380 complain);
11381 return cp_build_qualified_type_real
11382 (r, cp_type_quals (t), complain);
11384 else
11385 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11386 return convert_from_reference (unshare_expr (arg));
11389 if (level == 1)
11390 /* This can happen during the attempted tsubst'ing in
11391 unify. This means that we don't yet have any information
11392 about the template parameter in question. */
11393 return t;
11395 /* Early in template argument deduction substitution, we don't
11396 want to reduce the level of 'auto', or it will be confused
11397 with a normal template parm in subsequent deduction. */
11398 if (is_auto (t) && (complain & tf_partial))
11399 return t;
11401 /* If we get here, we must have been looking at a parm for a
11402 more deeply nested template. Make a new version of this
11403 template parameter, but with a lower level. */
11404 switch (code)
11406 case TEMPLATE_TYPE_PARM:
11407 case TEMPLATE_TEMPLATE_PARM:
11408 case BOUND_TEMPLATE_TEMPLATE_PARM:
11409 if (cp_type_quals (t))
11411 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11412 r = cp_build_qualified_type_real
11413 (r, cp_type_quals (t),
11414 complain | (code == TEMPLATE_TYPE_PARM
11415 ? tf_ignore_bad_quals : 0));
11417 else
11419 r = copy_type (t);
11420 TEMPLATE_TYPE_PARM_INDEX (r)
11421 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11422 r, levels, args, complain);
11423 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11424 TYPE_MAIN_VARIANT (r) = r;
11425 TYPE_POINTER_TO (r) = NULL_TREE;
11426 TYPE_REFERENCE_TO (r) = NULL_TREE;
11428 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11429 /* We have reduced the level of the template
11430 template parameter, but not the levels of its
11431 template parameters, so canonical_type_parameter
11432 will not be able to find the canonical template
11433 template parameter for this level. Thus, we
11434 require structural equality checking to compare
11435 TEMPLATE_TEMPLATE_PARMs. */
11436 SET_TYPE_STRUCTURAL_EQUALITY (r);
11437 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11438 SET_TYPE_STRUCTURAL_EQUALITY (r);
11439 else
11440 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11442 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11444 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11445 complain, in_decl);
11446 if (argvec == error_mark_node)
11447 return error_mark_node;
11449 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11450 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11453 break;
11455 case TEMPLATE_PARM_INDEX:
11456 r = reduce_template_parm_level (t, type, levels, args, complain);
11457 break;
11459 default:
11460 gcc_unreachable ();
11463 return r;
11466 case TREE_LIST:
11468 tree purpose, value, chain;
11470 if (t == void_list_node)
11471 return t;
11473 purpose = TREE_PURPOSE (t);
11474 if (purpose)
11476 purpose = tsubst (purpose, args, complain, in_decl);
11477 if (purpose == error_mark_node)
11478 return error_mark_node;
11480 value = TREE_VALUE (t);
11481 if (value)
11483 value = tsubst (value, args, complain, in_decl);
11484 if (value == error_mark_node)
11485 return error_mark_node;
11487 chain = TREE_CHAIN (t);
11488 if (chain && chain != void_type_node)
11490 chain = tsubst (chain, args, complain, in_decl);
11491 if (chain == error_mark_node)
11492 return error_mark_node;
11494 if (purpose == TREE_PURPOSE (t)
11495 && value == TREE_VALUE (t)
11496 && chain == TREE_CHAIN (t))
11497 return t;
11498 return hash_tree_cons (purpose, value, chain);
11501 case TREE_BINFO:
11502 /* We should never be tsubsting a binfo. */
11503 gcc_unreachable ();
11505 case TREE_VEC:
11506 /* A vector of template arguments. */
11507 gcc_assert (!type);
11508 return tsubst_template_args (t, args, complain, in_decl);
11510 case POINTER_TYPE:
11511 case REFERENCE_TYPE:
11513 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11514 return t;
11516 /* [temp.deduct]
11518 Type deduction may fail for any of the following
11519 reasons:
11521 -- Attempting to create a pointer to reference type.
11522 -- Attempting to create a reference to a reference type or
11523 a reference to void.
11525 Core issue 106 says that creating a reference to a reference
11526 during instantiation is no longer a cause for failure. We
11527 only enforce this check in strict C++98 mode. */
11528 if ((TREE_CODE (type) == REFERENCE_TYPE
11529 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11530 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
11532 static location_t last_loc;
11534 /* We keep track of the last time we issued this error
11535 message to avoid spewing a ton of messages during a
11536 single bad template instantiation. */
11537 if (complain & tf_error
11538 && last_loc != input_location)
11540 if (TREE_CODE (type) == VOID_TYPE)
11541 error ("forming reference to void");
11542 else if (code == POINTER_TYPE)
11543 error ("forming pointer to reference type %qT", type);
11544 else
11545 error ("forming reference to reference type %qT", type);
11546 last_loc = input_location;
11549 return error_mark_node;
11551 else if (code == POINTER_TYPE)
11553 r = build_pointer_type (type);
11554 if (TREE_CODE (type) == METHOD_TYPE)
11555 r = build_ptrmemfunc_type (r);
11557 else if (TREE_CODE (type) == REFERENCE_TYPE)
11558 /* In C++0x, during template argument substitution, when there is an
11559 attempt to create a reference to a reference type, reference
11560 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11562 "If a template-argument for a template-parameter T names a type
11563 that is a reference to a type A, an attempt to create the type
11564 'lvalue reference to cv T' creates the type 'lvalue reference to
11565 A,' while an attempt to create the type type rvalue reference to
11566 cv T' creates the type T"
11568 r = cp_build_reference_type
11569 (TREE_TYPE (type),
11570 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
11571 else
11572 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
11573 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11575 if (r != error_mark_node)
11576 /* Will this ever be needed for TYPE_..._TO values? */
11577 layout_type (r);
11579 return r;
11581 case OFFSET_TYPE:
11583 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
11584 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
11586 /* [temp.deduct]
11588 Type deduction may fail for any of the following
11589 reasons:
11591 -- Attempting to create "pointer to member of T" when T
11592 is not a class type. */
11593 if (complain & tf_error)
11594 error ("creating pointer to member of non-class type %qT", r);
11595 return error_mark_node;
11597 if (TREE_CODE (type) == REFERENCE_TYPE)
11599 if (complain & tf_error)
11600 error ("creating pointer to member reference type %qT", type);
11601 return error_mark_node;
11603 if (TREE_CODE (type) == VOID_TYPE)
11605 if (complain & tf_error)
11606 error ("creating pointer to member of type void");
11607 return error_mark_node;
11609 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
11610 if (TREE_CODE (type) == FUNCTION_TYPE)
11612 /* The type of the implicit object parameter gets its
11613 cv-qualifiers from the FUNCTION_TYPE. */
11614 tree memptr;
11615 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
11616 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
11617 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
11618 complain);
11620 else
11621 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
11622 cp_type_quals (t),
11623 complain);
11625 case FUNCTION_TYPE:
11626 case METHOD_TYPE:
11628 tree fntype;
11629 tree specs;
11630 fntype = tsubst_function_type (t, args, complain, in_decl);
11631 if (fntype == error_mark_node)
11632 return error_mark_node;
11634 /* Substitute the exception specification. */
11635 specs = tsubst_exception_specification (t, args, complain,
11636 in_decl, /*defer_ok*/true);
11637 if (specs == error_mark_node)
11638 return error_mark_node;
11639 if (specs)
11640 fntype = build_exception_variant (fntype, specs);
11641 return fntype;
11643 case ARRAY_TYPE:
11645 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
11646 if (domain == error_mark_node)
11647 return error_mark_node;
11649 /* As an optimization, we avoid regenerating the array type if
11650 it will obviously be the same as T. */
11651 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
11652 return t;
11654 /* These checks should match the ones in grokdeclarator.
11656 [temp.deduct]
11658 The deduction may fail for any of the following reasons:
11660 -- Attempting to create an array with an element type that
11661 is void, a function type, or a reference type, or [DR337]
11662 an abstract class type. */
11663 if (TREE_CODE (type) == VOID_TYPE
11664 || TREE_CODE (type) == FUNCTION_TYPE
11665 || TREE_CODE (type) == REFERENCE_TYPE)
11667 if (complain & tf_error)
11668 error ("creating array of %qT", type);
11669 return error_mark_node;
11672 if (abstract_virtuals_error_sfinae (ACU_ARRAY, type, complain))
11673 return error_mark_node;
11675 r = build_cplus_array_type (type, domain);
11677 if (TYPE_USER_ALIGN (t))
11679 TYPE_ALIGN (r) = TYPE_ALIGN (t);
11680 TYPE_USER_ALIGN (r) = 1;
11683 return r;
11686 case TYPENAME_TYPE:
11688 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11689 in_decl, /*entering_scope=*/1);
11690 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
11691 complain, in_decl);
11693 if (ctx == error_mark_node || f == error_mark_node)
11694 return error_mark_node;
11696 if (!MAYBE_CLASS_TYPE_P (ctx))
11698 if (complain & tf_error)
11699 error ("%qT is not a class, struct, or union type", ctx);
11700 return error_mark_node;
11702 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11704 /* Normally, make_typename_type does not require that the CTX
11705 have complete type in order to allow things like:
11707 template <class T> struct S { typename S<T>::X Y; };
11709 But, such constructs have already been resolved by this
11710 point, so here CTX really should have complete type, unless
11711 it's a partial instantiation. */
11712 ctx = complete_type (ctx);
11713 if (!COMPLETE_TYPE_P (ctx))
11715 if (complain & tf_error)
11716 cxx_incomplete_type_error (NULL_TREE, ctx);
11717 return error_mark_node;
11721 f = make_typename_type (ctx, f, typename_type,
11722 complain | tf_keep_type_decl);
11723 if (f == error_mark_node)
11724 return f;
11725 if (TREE_CODE (f) == TYPE_DECL)
11727 complain |= tf_ignore_bad_quals;
11728 f = TREE_TYPE (f);
11731 if (TREE_CODE (f) != TYPENAME_TYPE)
11733 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11735 if (complain & tf_error)
11736 error ("%qT resolves to %qT, which is not an enumeration type",
11737 t, f);
11738 else
11739 return error_mark_node;
11741 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11743 if (complain & tf_error)
11744 error ("%qT resolves to %qT, which is is not a class type",
11745 t, f);
11746 else
11747 return error_mark_node;
11751 return cp_build_qualified_type_real
11752 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11755 case UNBOUND_CLASS_TEMPLATE:
11757 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11758 in_decl, /*entering_scope=*/1);
11759 tree name = TYPE_IDENTIFIER (t);
11760 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11762 if (ctx == error_mark_node || name == error_mark_node)
11763 return error_mark_node;
11765 if (parm_list)
11766 parm_list = tsubst_template_parms (parm_list, args, complain);
11767 return make_unbound_class_template (ctx, name, parm_list, complain);
11770 case TYPEOF_TYPE:
11772 tree type;
11774 ++cp_unevaluated_operand;
11775 ++c_inhibit_evaluation_warnings;
11777 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11778 complain, in_decl,
11779 /*integral_constant_expression_p=*/false);
11781 --cp_unevaluated_operand;
11782 --c_inhibit_evaluation_warnings;
11784 type = finish_typeof (type);
11785 return cp_build_qualified_type_real (type,
11786 cp_type_quals (t)
11787 | cp_type_quals (type),
11788 complain);
11791 case DECLTYPE_TYPE:
11793 tree type;
11795 ++cp_unevaluated_operand;
11796 ++c_inhibit_evaluation_warnings;
11798 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11799 complain|tf_decltype, in_decl,
11800 /*integral_constant_expression_p=*/false);
11802 --cp_unevaluated_operand;
11803 --c_inhibit_evaluation_warnings;
11805 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11806 type = lambda_capture_field_type (type);
11807 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11808 type = lambda_proxy_type (type);
11809 else
11810 type = finish_decltype_type
11811 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11812 return cp_build_qualified_type_real (type,
11813 cp_type_quals (t)
11814 | cp_type_quals (type),
11815 complain);
11818 case UNDERLYING_TYPE:
11820 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11821 complain, in_decl);
11822 return finish_underlying_type (type);
11825 case TYPE_ARGUMENT_PACK:
11826 case NONTYPE_ARGUMENT_PACK:
11828 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11829 tree packed_out =
11830 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11831 args,
11832 complain,
11833 in_decl);
11834 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11836 /* For template nontype argument packs, also substitute into
11837 the type. */
11838 if (code == NONTYPE_ARGUMENT_PACK)
11839 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11841 return r;
11843 break;
11845 case INTEGER_CST:
11846 case REAL_CST:
11847 case STRING_CST:
11848 case PLUS_EXPR:
11849 case MINUS_EXPR:
11850 case NEGATE_EXPR:
11851 case NOP_EXPR:
11852 case INDIRECT_REF:
11853 case ADDR_EXPR:
11854 case CALL_EXPR:
11855 case ARRAY_REF:
11856 case SCOPE_REF:
11857 /* We should use one of the expression tsubsts for these codes. */
11858 gcc_unreachable ();
11860 default:
11861 sorry ("use of %qs in template", tree_code_name [(int) code]);
11862 return error_mark_node;
11866 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11867 type of the expression on the left-hand side of the "." or "->"
11868 operator. */
11870 static tree
11871 tsubst_baselink (tree baselink, tree object_type,
11872 tree args, tsubst_flags_t complain, tree in_decl)
11874 tree name;
11875 tree qualifying_scope;
11876 tree fns;
11877 tree optype;
11878 tree template_args = 0;
11879 bool template_id_p = false;
11880 bool qualified = BASELINK_QUALIFIED_P (baselink);
11882 /* A baselink indicates a function from a base class. Both the
11883 BASELINK_ACCESS_BINFO and the base class referenced may
11884 indicate bases of the template class, rather than the
11885 instantiated class. In addition, lookups that were not
11886 ambiguous before may be ambiguous now. Therefore, we perform
11887 the lookup again. */
11888 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11889 qualifying_scope = tsubst (qualifying_scope, args,
11890 complain, in_decl);
11891 fns = BASELINK_FUNCTIONS (baselink);
11892 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11893 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11895 template_id_p = true;
11896 template_args = TREE_OPERAND (fns, 1);
11897 fns = TREE_OPERAND (fns, 0);
11898 if (template_args)
11899 template_args = tsubst_template_args (template_args, args,
11900 complain, in_decl);
11902 name = DECL_NAME (get_first_fn (fns));
11903 if (IDENTIFIER_TYPENAME_P (name))
11904 name = mangle_conv_op_name_for_type (optype);
11905 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11906 if (!baselink)
11907 return error_mark_node;
11909 /* If lookup found a single function, mark it as used at this
11910 point. (If it lookup found multiple functions the one selected
11911 later by overload resolution will be marked as used at that
11912 point.) */
11913 if (BASELINK_P (baselink))
11914 fns = BASELINK_FUNCTIONS (baselink);
11915 if (!template_id_p && !really_overloaded_fn (fns))
11916 mark_used (OVL_CURRENT (fns));
11918 /* Add back the template arguments, if present. */
11919 if (BASELINK_P (baselink) && template_id_p)
11920 BASELINK_FUNCTIONS (baselink)
11921 = build_nt (TEMPLATE_ID_EXPR,
11922 BASELINK_FUNCTIONS (baselink),
11923 template_args);
11924 /* Update the conversion operator type. */
11925 BASELINK_OPTYPE (baselink) = optype;
11927 if (!object_type)
11928 object_type = current_class_type;
11930 if (qualified)
11931 baselink = adjust_result_of_qualified_name_lookup (baselink,
11932 qualifying_scope,
11933 object_type);
11934 return baselink;
11937 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11938 true if the qualified-id will be a postfix-expression in-and-of
11939 itself; false if more of the postfix-expression follows the
11940 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11941 of "&". */
11943 static tree
11944 tsubst_qualified_id (tree qualified_id, tree args,
11945 tsubst_flags_t complain, tree in_decl,
11946 bool done, bool address_p)
11948 tree expr;
11949 tree scope;
11950 tree name;
11951 bool is_template;
11952 tree template_args;
11953 location_t loc = UNKNOWN_LOCATION;
11955 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11957 /* Figure out what name to look up. */
11958 name = TREE_OPERAND (qualified_id, 1);
11959 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11961 is_template = true;
11962 loc = EXPR_LOCATION (name);
11963 template_args = TREE_OPERAND (name, 1);
11964 if (template_args)
11965 template_args = tsubst_template_args (template_args, args,
11966 complain, in_decl);
11967 name = TREE_OPERAND (name, 0);
11969 else
11971 is_template = false;
11972 template_args = NULL_TREE;
11975 /* Substitute into the qualifying scope. When there are no ARGS, we
11976 are just trying to simplify a non-dependent expression. In that
11977 case the qualifying scope may be dependent, and, in any case,
11978 substituting will not help. */
11979 scope = TREE_OPERAND (qualified_id, 0);
11980 if (args)
11982 scope = tsubst (scope, args, complain, in_decl);
11983 expr = tsubst_copy (name, args, complain, in_decl);
11985 else
11986 expr = name;
11988 if (dependent_scope_p (scope))
11990 if (is_template)
11991 expr = build_min_nt_loc (loc, TEMPLATE_ID_EXPR, expr, template_args);
11992 return build_qualified_name (NULL_TREE, scope, expr,
11993 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11996 if (!BASELINK_P (name) && !DECL_P (expr))
11998 if (TREE_CODE (expr) == BIT_NOT_EXPR)
12000 /* A BIT_NOT_EXPR is used to represent a destructor. */
12001 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
12003 error ("qualifying type %qT does not match destructor name ~%qT",
12004 scope, TREE_OPERAND (expr, 0));
12005 expr = error_mark_node;
12007 else
12008 expr = lookup_qualified_name (scope, complete_dtor_identifier,
12009 /*is_type_p=*/0, false);
12011 else
12012 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
12013 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
12014 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
12016 if (complain & tf_error)
12018 error ("dependent-name %qE is parsed as a non-type, but "
12019 "instantiation yields a type", qualified_id);
12020 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
12022 return error_mark_node;
12026 if (DECL_P (expr))
12028 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
12029 scope);
12030 /* Remember that there was a reference to this entity. */
12031 mark_used (expr);
12034 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
12036 if (complain & tf_error)
12037 qualified_name_lookup_error (scope,
12038 TREE_OPERAND (qualified_id, 1),
12039 expr, input_location);
12040 return error_mark_node;
12043 if (is_template)
12044 expr = lookup_template_function (expr, template_args);
12046 if (expr == error_mark_node && complain & tf_error)
12047 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
12048 expr, input_location);
12049 else if (TYPE_P (scope))
12051 expr = (adjust_result_of_qualified_name_lookup
12052 (expr, scope, current_nonlambda_class_type ()));
12053 expr = (finish_qualified_id_expr
12054 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
12055 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
12056 /*template_arg_p=*/false));
12059 /* Expressions do not generally have reference type. */
12060 if (TREE_CODE (expr) != SCOPE_REF
12061 /* However, if we're about to form a pointer-to-member, we just
12062 want the referenced member referenced. */
12063 && TREE_CODE (expr) != OFFSET_REF)
12064 expr = convert_from_reference (expr);
12066 return expr;
12069 /* Like tsubst, but deals with expressions. This function just replaces
12070 template parms; to finish processing the resultant expression, use
12071 tsubst_copy_and_build or tsubst_expr. */
12073 static tree
12074 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
12076 enum tree_code code;
12077 tree r;
12079 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
12080 return t;
12082 code = TREE_CODE (t);
12084 switch (code)
12086 case PARM_DECL:
12087 r = retrieve_local_specialization (t);
12089 if (r == NULL_TREE)
12091 /* We get here for a use of 'this' in an NSDMI. */
12092 if (DECL_NAME (t) == this_identifier
12093 && at_function_scope_p ()
12094 && DECL_CONSTRUCTOR_P (current_function_decl))
12095 return current_class_ptr;
12097 /* This can happen for a parameter name used later in a function
12098 declaration (such as in a late-specified return type). Just
12099 make a dummy decl, since it's only used for its type. */
12100 gcc_assert (cp_unevaluated_operand != 0);
12101 r = tsubst_decl (t, args, complain);
12102 /* Give it the template pattern as its context; its true context
12103 hasn't been instantiated yet and this is good enough for
12104 mangling. */
12105 DECL_CONTEXT (r) = DECL_CONTEXT (t);
12108 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
12109 r = ARGUMENT_PACK_SELECT_ARG (r);
12110 mark_used (r);
12111 return r;
12113 case CONST_DECL:
12115 tree enum_type;
12116 tree v;
12118 if (DECL_TEMPLATE_PARM_P (t))
12119 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
12120 /* There is no need to substitute into namespace-scope
12121 enumerators. */
12122 if (DECL_NAMESPACE_SCOPE_P (t))
12123 return t;
12124 /* If ARGS is NULL, then T is known to be non-dependent. */
12125 if (args == NULL_TREE)
12126 return integral_constant_value (t);
12128 /* Unfortunately, we cannot just call lookup_name here.
12129 Consider:
12131 template <int I> int f() {
12132 enum E { a = I };
12133 struct S { void g() { E e = a; } };
12136 When we instantiate f<7>::S::g(), say, lookup_name is not
12137 clever enough to find f<7>::a. */
12138 enum_type
12139 = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12140 /*entering_scope=*/0);
12142 for (v = TYPE_VALUES (enum_type);
12143 v != NULL_TREE;
12144 v = TREE_CHAIN (v))
12145 if (TREE_PURPOSE (v) == DECL_NAME (t))
12146 return TREE_VALUE (v);
12148 /* We didn't find the name. That should never happen; if
12149 name-lookup found it during preliminary parsing, we
12150 should find it again here during instantiation. */
12151 gcc_unreachable ();
12153 return t;
12155 case FIELD_DECL:
12156 if (DECL_CONTEXT (t))
12158 tree ctx;
12160 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12161 /*entering_scope=*/1);
12162 if (ctx != DECL_CONTEXT (t))
12164 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
12165 if (!r)
12167 if (complain & tf_error)
12168 error ("using invalid field %qD", t);
12169 return error_mark_node;
12171 return r;
12175 return t;
12177 case VAR_DECL:
12178 case FUNCTION_DECL:
12179 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
12180 || local_variable_p (t))
12181 t = tsubst (t, args, complain, in_decl);
12182 mark_used (t);
12183 return t;
12185 case NAMESPACE_DECL:
12186 return t;
12188 case OVERLOAD:
12189 /* An OVERLOAD will always be a non-dependent overload set; an
12190 overload set from function scope will just be represented with an
12191 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12192 gcc_assert (!uses_template_parms (t));
12193 return t;
12195 case BASELINK:
12196 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
12198 case TEMPLATE_DECL:
12199 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
12200 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
12201 args, complain, in_decl);
12202 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
12203 return tsubst (t, args, complain, in_decl);
12204 else if (DECL_CLASS_SCOPE_P (t)
12205 && uses_template_parms (DECL_CONTEXT (t)))
12207 /* Template template argument like the following example need
12208 special treatment:
12210 template <template <class> class TT> struct C {};
12211 template <class T> struct D {
12212 template <class U> struct E {};
12213 C<E> c; // #1
12215 D<int> d; // #2
12217 We are processing the template argument `E' in #1 for
12218 the template instantiation #2. Originally, `E' is a
12219 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12220 have to substitute this with one having context `D<int>'. */
12222 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12223 return lookup_field (context, DECL_NAME(t), 0, false);
12225 else
12226 /* Ordinary template template argument. */
12227 return t;
12229 case CAST_EXPR:
12230 case REINTERPRET_CAST_EXPR:
12231 case CONST_CAST_EXPR:
12232 case STATIC_CAST_EXPR:
12233 case DYNAMIC_CAST_EXPR:
12234 case IMPLICIT_CONV_EXPR:
12235 case CONVERT_EXPR:
12236 case NOP_EXPR:
12237 return build1
12238 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12239 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12241 case SIZEOF_EXPR:
12242 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12245 tree expanded, op = TREE_OPERAND (t, 0);
12246 int len = 0;
12248 if (SIZEOF_EXPR_TYPE_P (t))
12249 op = TREE_TYPE (op);
12251 ++cp_unevaluated_operand;
12252 ++c_inhibit_evaluation_warnings;
12253 /* We only want to compute the number of arguments. */
12254 expanded = tsubst_pack_expansion (op, args, complain, in_decl);
12255 --cp_unevaluated_operand;
12256 --c_inhibit_evaluation_warnings;
12258 if (TREE_CODE (expanded) == TREE_VEC)
12259 len = TREE_VEC_LENGTH (expanded);
12261 if (expanded == error_mark_node)
12262 return error_mark_node;
12263 else if (PACK_EXPANSION_P (expanded)
12264 || (TREE_CODE (expanded) == TREE_VEC
12265 && len > 0
12266 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
12268 if (TREE_CODE (expanded) == TREE_VEC)
12269 expanded = TREE_VEC_ELT (expanded, len - 1);
12271 if (TYPE_P (expanded))
12272 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
12273 complain & tf_error);
12274 else
12275 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
12276 complain & tf_error);
12278 else
12279 return build_int_cst (size_type_node, len);
12281 if (SIZEOF_EXPR_TYPE_P (t))
12283 r = tsubst (TREE_TYPE (TREE_OPERAND (t, 0)),
12284 args, complain, in_decl);
12285 r = build1 (NOP_EXPR, r, error_mark_node);
12286 r = build1 (SIZEOF_EXPR,
12287 tsubst (TREE_TYPE (t), args, complain, in_decl), r);
12288 SIZEOF_EXPR_TYPE_P (r) = 1;
12289 return r;
12291 /* Fall through */
12293 case INDIRECT_REF:
12294 case NEGATE_EXPR:
12295 case TRUTH_NOT_EXPR:
12296 case BIT_NOT_EXPR:
12297 case ADDR_EXPR:
12298 case UNARY_PLUS_EXPR: /* Unary + */
12299 case ALIGNOF_EXPR:
12300 case AT_ENCODE_EXPR:
12301 case ARROW_EXPR:
12302 case THROW_EXPR:
12303 case TYPEID_EXPR:
12304 case REALPART_EXPR:
12305 case IMAGPART_EXPR:
12306 return build1
12307 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12308 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12310 case COMPONENT_REF:
12312 tree object;
12313 tree name;
12315 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
12316 name = TREE_OPERAND (t, 1);
12317 if (TREE_CODE (name) == BIT_NOT_EXPR)
12319 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12320 complain, in_decl);
12321 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12323 else if (TREE_CODE (name) == SCOPE_REF
12324 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
12326 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
12327 complain, in_decl);
12328 name = TREE_OPERAND (name, 1);
12329 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12330 complain, in_decl);
12331 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12332 name = build_qualified_name (/*type=*/NULL_TREE,
12333 base, name,
12334 /*template_p=*/false);
12336 else if (BASELINK_P (name))
12337 name = tsubst_baselink (name,
12338 non_reference (TREE_TYPE (object)),
12339 args, complain,
12340 in_decl);
12341 else
12342 name = tsubst_copy (name, args, complain, in_decl);
12343 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
12346 case PLUS_EXPR:
12347 case MINUS_EXPR:
12348 case MULT_EXPR:
12349 case TRUNC_DIV_EXPR:
12350 case CEIL_DIV_EXPR:
12351 case FLOOR_DIV_EXPR:
12352 case ROUND_DIV_EXPR:
12353 case EXACT_DIV_EXPR:
12354 case BIT_AND_EXPR:
12355 case BIT_IOR_EXPR:
12356 case BIT_XOR_EXPR:
12357 case TRUNC_MOD_EXPR:
12358 case FLOOR_MOD_EXPR:
12359 case TRUTH_ANDIF_EXPR:
12360 case TRUTH_ORIF_EXPR:
12361 case TRUTH_AND_EXPR:
12362 case TRUTH_OR_EXPR:
12363 case RSHIFT_EXPR:
12364 case LSHIFT_EXPR:
12365 case RROTATE_EXPR:
12366 case LROTATE_EXPR:
12367 case EQ_EXPR:
12368 case NE_EXPR:
12369 case MAX_EXPR:
12370 case MIN_EXPR:
12371 case LE_EXPR:
12372 case GE_EXPR:
12373 case LT_EXPR:
12374 case GT_EXPR:
12375 case COMPOUND_EXPR:
12376 case DOTSTAR_EXPR:
12377 case MEMBER_REF:
12378 case PREDECREMENT_EXPR:
12379 case PREINCREMENT_EXPR:
12380 case POSTDECREMENT_EXPR:
12381 case POSTINCREMENT_EXPR:
12382 return build_nt
12383 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12384 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12386 case SCOPE_REF:
12387 return build_qualified_name (/*type=*/NULL_TREE,
12388 tsubst_copy (TREE_OPERAND (t, 0),
12389 args, complain, in_decl),
12390 tsubst_copy (TREE_OPERAND (t, 1),
12391 args, complain, in_decl),
12392 QUALIFIED_NAME_IS_TEMPLATE (t));
12394 case ARRAY_REF:
12395 return build_nt
12396 (ARRAY_REF,
12397 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12398 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12399 NULL_TREE, NULL_TREE);
12401 case CALL_EXPR:
12403 int n = VL_EXP_OPERAND_LENGTH (t);
12404 tree result = build_vl_exp (CALL_EXPR, n);
12405 int i;
12406 for (i = 0; i < n; i++)
12407 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
12408 complain, in_decl);
12409 return result;
12412 case COND_EXPR:
12413 case MODOP_EXPR:
12414 case PSEUDO_DTOR_EXPR:
12416 r = build_nt
12417 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12418 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12419 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12420 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12421 return r;
12424 case NEW_EXPR:
12426 r = build_nt
12427 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12428 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12429 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12430 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12431 return r;
12434 case DELETE_EXPR:
12436 r = build_nt
12437 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12438 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12439 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12440 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12441 return r;
12444 case TEMPLATE_ID_EXPR:
12446 /* Substituted template arguments */
12447 tree fn = TREE_OPERAND (t, 0);
12448 tree targs = TREE_OPERAND (t, 1);
12450 fn = tsubst_copy (fn, args, complain, in_decl);
12451 if (targs)
12452 targs = tsubst_template_args (targs, args, complain, in_decl);
12454 return lookup_template_function (fn, targs);
12457 case TREE_LIST:
12459 tree purpose, value, chain;
12461 if (t == void_list_node)
12462 return t;
12464 purpose = TREE_PURPOSE (t);
12465 if (purpose)
12466 purpose = tsubst_copy (purpose, args, complain, in_decl);
12467 value = TREE_VALUE (t);
12468 if (value)
12469 value = tsubst_copy (value, args, complain, in_decl);
12470 chain = TREE_CHAIN (t);
12471 if (chain && chain != void_type_node)
12472 chain = tsubst_copy (chain, args, complain, in_decl);
12473 if (purpose == TREE_PURPOSE (t)
12474 && value == TREE_VALUE (t)
12475 && chain == TREE_CHAIN (t))
12476 return t;
12477 return tree_cons (purpose, value, chain);
12480 case RECORD_TYPE:
12481 case UNION_TYPE:
12482 case ENUMERAL_TYPE:
12483 case INTEGER_TYPE:
12484 case TEMPLATE_TYPE_PARM:
12485 case TEMPLATE_TEMPLATE_PARM:
12486 case BOUND_TEMPLATE_TEMPLATE_PARM:
12487 case TEMPLATE_PARM_INDEX:
12488 case POINTER_TYPE:
12489 case REFERENCE_TYPE:
12490 case OFFSET_TYPE:
12491 case FUNCTION_TYPE:
12492 case METHOD_TYPE:
12493 case ARRAY_TYPE:
12494 case TYPENAME_TYPE:
12495 case UNBOUND_CLASS_TEMPLATE:
12496 case TYPEOF_TYPE:
12497 case DECLTYPE_TYPE:
12498 case TYPE_DECL:
12499 return tsubst (t, args, complain, in_decl);
12501 case IDENTIFIER_NODE:
12502 if (IDENTIFIER_TYPENAME_P (t))
12504 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12505 return mangle_conv_op_name_for_type (new_type);
12507 else
12508 return t;
12510 case CONSTRUCTOR:
12511 /* This is handled by tsubst_copy_and_build. */
12512 gcc_unreachable ();
12514 case VA_ARG_EXPR:
12515 return build_x_va_arg (EXPR_LOCATION (t),
12516 tsubst_copy (TREE_OPERAND (t, 0), args, complain,
12517 in_decl),
12518 tsubst (TREE_TYPE (t), args, complain, in_decl));
12520 case CLEANUP_POINT_EXPR:
12521 /* We shouldn't have built any of these during initial template
12522 generation. Instead, they should be built during instantiation
12523 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12524 gcc_unreachable ();
12526 case OFFSET_REF:
12527 r = build2
12528 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12529 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12530 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12531 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
12532 mark_used (TREE_OPERAND (r, 1));
12533 return r;
12535 case EXPR_PACK_EXPANSION:
12536 error ("invalid use of pack expansion expression");
12537 return error_mark_node;
12539 case NONTYPE_ARGUMENT_PACK:
12540 error ("use %<...%> to expand argument pack");
12541 return error_mark_node;
12543 case INTEGER_CST:
12544 case REAL_CST:
12545 case STRING_CST:
12546 case COMPLEX_CST:
12548 /* Instantiate any typedefs in the type. */
12549 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12550 r = fold_convert (type, t);
12551 gcc_assert (TREE_CODE (r) == code);
12552 return r;
12555 case PTRMEM_CST:
12556 /* These can sometimes show up in a partial instantiation, but never
12557 involve template parms. */
12558 gcc_assert (!uses_template_parms (t));
12559 return t;
12561 default:
12562 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12563 gcc_checking_assert (false);
12564 return t;
12568 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12570 static tree
12571 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
12572 tree in_decl)
12574 tree new_clauses = NULL, nc, oc;
12576 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
12578 nc = copy_node (oc);
12579 OMP_CLAUSE_CHAIN (nc) = new_clauses;
12580 new_clauses = nc;
12582 switch (OMP_CLAUSE_CODE (nc))
12584 case OMP_CLAUSE_LASTPRIVATE:
12585 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
12587 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
12588 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
12589 in_decl, /*integral_constant_expression_p=*/false);
12590 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
12591 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
12593 /* FALLTHRU */
12594 case OMP_CLAUSE_PRIVATE:
12595 case OMP_CLAUSE_SHARED:
12596 case OMP_CLAUSE_FIRSTPRIVATE:
12597 case OMP_CLAUSE_REDUCTION:
12598 case OMP_CLAUSE_COPYIN:
12599 case OMP_CLAUSE_COPYPRIVATE:
12600 case OMP_CLAUSE_IF:
12601 case OMP_CLAUSE_NUM_THREADS:
12602 case OMP_CLAUSE_SCHEDULE:
12603 case OMP_CLAUSE_COLLAPSE:
12604 case OMP_CLAUSE_FINAL:
12605 OMP_CLAUSE_OPERAND (nc, 0)
12606 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
12607 in_decl, /*integral_constant_expression_p=*/false);
12608 break;
12609 case OMP_CLAUSE_NOWAIT:
12610 case OMP_CLAUSE_ORDERED:
12611 case OMP_CLAUSE_DEFAULT:
12612 case OMP_CLAUSE_UNTIED:
12613 case OMP_CLAUSE_MERGEABLE:
12614 break;
12615 default:
12616 gcc_unreachable ();
12620 return finish_omp_clauses (nreverse (new_clauses));
12623 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12625 static tree
12626 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
12627 tree in_decl)
12629 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12631 tree purpose, value, chain;
12633 if (t == NULL)
12634 return t;
12636 if (TREE_CODE (t) != TREE_LIST)
12637 return tsubst_copy_and_build (t, args, complain, in_decl,
12638 /*function_p=*/false,
12639 /*integral_constant_expression_p=*/false);
12641 if (t == void_list_node)
12642 return t;
12644 purpose = TREE_PURPOSE (t);
12645 if (purpose)
12646 purpose = RECUR (purpose);
12647 value = TREE_VALUE (t);
12648 if (value)
12650 if (TREE_CODE (value) != LABEL_DECL)
12651 value = RECUR (value);
12652 else
12654 value = lookup_label (DECL_NAME (value));
12655 gcc_assert (TREE_CODE (value) == LABEL_DECL);
12656 TREE_USED (value) = 1;
12659 chain = TREE_CHAIN (t);
12660 if (chain && chain != void_type_node)
12661 chain = RECUR (chain);
12662 return tree_cons (purpose, value, chain);
12663 #undef RECUR
12666 /* Substitute one OMP_FOR iterator. */
12668 static void
12669 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
12670 tree condv, tree incrv, tree *clauses,
12671 tree args, tsubst_flags_t complain, tree in_decl,
12672 bool integral_constant_expression_p)
12674 #define RECUR(NODE) \
12675 tsubst_expr ((NODE), args, complain, in_decl, \
12676 integral_constant_expression_p)
12677 tree decl, init, cond, incr;
12678 bool init_decl;
12680 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
12681 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
12682 decl = TREE_OPERAND (init, 0);
12683 init = TREE_OPERAND (init, 1);
12684 /* Do this before substituting into decl to handle 'auto'. */
12685 init_decl = (init && TREE_CODE (init) == DECL_EXPR);
12686 init = RECUR (init);
12687 decl = RECUR (decl);
12688 if (init_decl)
12690 gcc_assert (!processing_template_decl);
12691 init = DECL_INITIAL (decl);
12692 DECL_INITIAL (decl) = NULL_TREE;
12695 gcc_assert (!type_dependent_expression_p (decl));
12697 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
12699 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
12700 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12701 if (TREE_CODE (incr) == MODIFY_EXPR)
12702 incr = build_x_modify_expr (EXPR_LOCATION (incr),
12703 RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
12704 RECUR (TREE_OPERAND (incr, 1)),
12705 complain);
12706 else
12707 incr = RECUR (incr);
12708 TREE_VEC_ELT (declv, i) = decl;
12709 TREE_VEC_ELT (initv, i) = init;
12710 TREE_VEC_ELT (condv, i) = cond;
12711 TREE_VEC_ELT (incrv, i) = incr;
12712 return;
12715 if (init && !init_decl)
12717 tree c;
12718 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
12720 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
12721 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
12722 && OMP_CLAUSE_DECL (c) == decl)
12723 break;
12724 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
12725 && OMP_CLAUSE_DECL (c) == decl)
12726 error ("iteration variable %qD should not be firstprivate", decl);
12727 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
12728 && OMP_CLAUSE_DECL (c) == decl)
12729 error ("iteration variable %qD should not be reduction", decl);
12731 if (c == NULL)
12733 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
12734 OMP_CLAUSE_DECL (c) = decl;
12735 c = finish_omp_clauses (c);
12736 if (c)
12738 OMP_CLAUSE_CHAIN (c) = *clauses;
12739 *clauses = c;
12743 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12744 if (COMPARISON_CLASS_P (cond))
12745 cond = build2 (TREE_CODE (cond), boolean_type_node,
12746 RECUR (TREE_OPERAND (cond, 0)),
12747 RECUR (TREE_OPERAND (cond, 1)));
12748 else
12749 cond = RECUR (cond);
12750 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12751 switch (TREE_CODE (incr))
12753 case PREINCREMENT_EXPR:
12754 case PREDECREMENT_EXPR:
12755 case POSTINCREMENT_EXPR:
12756 case POSTDECREMENT_EXPR:
12757 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12758 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12759 break;
12760 case MODIFY_EXPR:
12761 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12762 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12764 tree rhs = TREE_OPERAND (incr, 1);
12765 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12766 RECUR (TREE_OPERAND (incr, 0)),
12767 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12768 RECUR (TREE_OPERAND (rhs, 0)),
12769 RECUR (TREE_OPERAND (rhs, 1))));
12771 else
12772 incr = RECUR (incr);
12773 break;
12774 case MODOP_EXPR:
12775 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12776 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12778 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12779 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12780 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12781 TREE_TYPE (decl), lhs,
12782 RECUR (TREE_OPERAND (incr, 2))));
12784 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12785 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12786 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12788 tree rhs = TREE_OPERAND (incr, 2);
12789 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12790 RECUR (TREE_OPERAND (incr, 0)),
12791 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12792 RECUR (TREE_OPERAND (rhs, 0)),
12793 RECUR (TREE_OPERAND (rhs, 1))));
12795 else
12796 incr = RECUR (incr);
12797 break;
12798 default:
12799 incr = RECUR (incr);
12800 break;
12803 TREE_VEC_ELT (declv, i) = decl;
12804 TREE_VEC_ELT (initv, i) = init;
12805 TREE_VEC_ELT (condv, i) = cond;
12806 TREE_VEC_ELT (incrv, i) = incr;
12807 #undef RECUR
12810 /* Like tsubst_copy for expressions, etc. but also does semantic
12811 processing. */
12813 static tree
12814 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12815 bool integral_constant_expression_p)
12817 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
12818 #define RECUR(NODE) \
12819 tsubst_expr ((NODE), args, complain, in_decl, \
12820 integral_constant_expression_p)
12822 tree stmt, tmp;
12823 tree r;
12824 location_t loc;
12826 if (t == NULL_TREE || t == error_mark_node)
12827 return t;
12829 loc = input_location;
12830 if (EXPR_HAS_LOCATION (t))
12831 input_location = EXPR_LOCATION (t);
12832 if (STATEMENT_CODE_P (TREE_CODE (t)))
12833 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12835 switch (TREE_CODE (t))
12837 case STATEMENT_LIST:
12839 tree_stmt_iterator i;
12840 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12841 RECUR (tsi_stmt (i));
12842 break;
12845 case CTOR_INITIALIZER:
12846 finish_mem_initializers (tsubst_initializer_list
12847 (TREE_OPERAND (t, 0), args));
12848 break;
12850 case RETURN_EXPR:
12851 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12852 break;
12854 case EXPR_STMT:
12855 tmp = RECUR (EXPR_STMT_EXPR (t));
12856 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12857 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12858 else
12859 finish_expr_stmt (tmp);
12860 break;
12862 case USING_STMT:
12863 do_using_directive (USING_STMT_NAMESPACE (t));
12864 break;
12866 case DECL_EXPR:
12868 tree decl, pattern_decl;
12869 tree init;
12871 pattern_decl = decl = DECL_EXPR_DECL (t);
12872 if (TREE_CODE (decl) == LABEL_DECL)
12873 finish_label_decl (DECL_NAME (decl));
12874 else if (TREE_CODE (decl) == USING_DECL)
12876 tree scope = USING_DECL_SCOPE (decl);
12877 tree name = DECL_NAME (decl);
12878 tree decl;
12880 scope = tsubst (scope, args, complain, in_decl);
12881 decl = lookup_qualified_name (scope, name,
12882 /*is_type_p=*/false,
12883 /*complain=*/false);
12884 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12885 qualified_name_lookup_error (scope, name, decl, input_location);
12886 else
12887 do_local_using_decl (decl, scope, name);
12889 else
12891 init = DECL_INITIAL (decl);
12892 decl = tsubst (decl, args, complain, in_decl);
12893 if (decl != error_mark_node)
12895 /* By marking the declaration as instantiated, we avoid
12896 trying to instantiate it. Since instantiate_decl can't
12897 handle local variables, and since we've already done
12898 all that needs to be done, that's the right thing to
12899 do. */
12900 if (TREE_CODE (decl) == VAR_DECL)
12901 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12902 if (TREE_CODE (decl) == VAR_DECL
12903 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12904 /* Anonymous aggregates are a special case. */
12905 finish_anon_union (decl);
12906 else if (is_capture_proxy (DECL_EXPR_DECL (t)))
12908 DECL_CONTEXT (decl) = current_function_decl;
12909 if (DECL_NAME (decl) == this_identifier)
12911 tree lam = DECL_CONTEXT (current_function_decl);
12912 lam = CLASSTYPE_LAMBDA_EXPR (lam);
12913 LAMBDA_EXPR_THIS_CAPTURE (lam) = decl;
12915 insert_capture_proxy (decl);
12917 else if (DECL_IMPLICIT_TYPEDEF_P (t))
12918 /* We already did a pushtag. */;
12919 else
12921 int const_init = false;
12922 maybe_push_decl (decl);
12923 if (TREE_CODE (decl) == VAR_DECL
12924 && DECL_PRETTY_FUNCTION_P (decl))
12926 /* For __PRETTY_FUNCTION__ we have to adjust the
12927 initializer. */
12928 const char *const name
12929 = cxx_printable_name (current_function_decl, 2);
12930 init = cp_fname_init (name, &TREE_TYPE (decl));
12932 else
12934 tree t = RECUR (init);
12936 if (init && !t)
12938 /* If we had an initializer but it
12939 instantiated to nothing,
12940 value-initialize the object. This will
12941 only occur when the initializer was a
12942 pack expansion where the parameter packs
12943 used in that expansion were of length
12944 zero. */
12945 init = build_value_init (TREE_TYPE (decl),
12946 complain);
12947 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12948 init = get_target_expr_sfinae (init, complain);
12950 else
12951 init = t;
12954 if (TREE_CODE (decl) == VAR_DECL)
12955 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12956 (pattern_decl));
12957 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12962 break;
12965 case FOR_STMT:
12966 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12967 RECUR (FOR_INIT_STMT (t));
12968 finish_for_init_stmt (stmt);
12969 tmp = RECUR (FOR_COND (t));
12970 finish_for_cond (tmp, stmt);
12971 tmp = RECUR (FOR_EXPR (t));
12972 finish_for_expr (tmp, stmt);
12973 RECUR (FOR_BODY (t));
12974 finish_for_stmt (stmt);
12975 break;
12977 case RANGE_FOR_STMT:
12979 tree decl, expr;
12980 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12981 decl = RANGE_FOR_DECL (t);
12982 decl = tsubst (decl, args, complain, in_decl);
12983 maybe_push_decl (decl);
12984 expr = RECUR (RANGE_FOR_EXPR (t));
12985 stmt = cp_convert_range_for (stmt, decl, expr);
12986 RECUR (RANGE_FOR_BODY (t));
12987 finish_for_stmt (stmt);
12989 break;
12991 case WHILE_STMT:
12992 stmt = begin_while_stmt ();
12993 tmp = RECUR (WHILE_COND (t));
12994 finish_while_stmt_cond (tmp, stmt);
12995 RECUR (WHILE_BODY (t));
12996 finish_while_stmt (stmt);
12997 break;
12999 case DO_STMT:
13000 stmt = begin_do_stmt ();
13001 RECUR (DO_BODY (t));
13002 finish_do_body (stmt);
13003 tmp = RECUR (DO_COND (t));
13004 finish_do_stmt (tmp, stmt);
13005 break;
13007 case IF_STMT:
13008 stmt = begin_if_stmt ();
13009 tmp = RECUR (IF_COND (t));
13010 finish_if_stmt_cond (tmp, stmt);
13011 RECUR (THEN_CLAUSE (t));
13012 finish_then_clause (stmt);
13014 if (ELSE_CLAUSE (t))
13016 begin_else_clause (stmt);
13017 RECUR (ELSE_CLAUSE (t));
13018 finish_else_clause (stmt);
13021 finish_if_stmt (stmt);
13022 break;
13024 case BIND_EXPR:
13025 if (BIND_EXPR_BODY_BLOCK (t))
13026 stmt = begin_function_body ();
13027 else
13028 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
13029 ? BCS_TRY_BLOCK : 0);
13031 RECUR (BIND_EXPR_BODY (t));
13033 if (BIND_EXPR_BODY_BLOCK (t))
13034 finish_function_body (stmt);
13035 else
13036 finish_compound_stmt (stmt);
13037 break;
13039 case BREAK_STMT:
13040 finish_break_stmt ();
13041 break;
13043 case CONTINUE_STMT:
13044 finish_continue_stmt ();
13045 break;
13047 case SWITCH_STMT:
13048 stmt = begin_switch_stmt ();
13049 tmp = RECUR (SWITCH_STMT_COND (t));
13050 finish_switch_cond (tmp, stmt);
13051 RECUR (SWITCH_STMT_BODY (t));
13052 finish_switch_stmt (stmt);
13053 break;
13055 case CASE_LABEL_EXPR:
13056 finish_case_label (EXPR_LOCATION (t),
13057 RECUR (CASE_LOW (t)),
13058 RECUR (CASE_HIGH (t)));
13059 break;
13061 case LABEL_EXPR:
13063 tree decl = LABEL_EXPR_LABEL (t);
13064 tree label;
13066 label = finish_label_stmt (DECL_NAME (decl));
13067 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
13068 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
13070 break;
13072 case GOTO_EXPR:
13073 tmp = GOTO_DESTINATION (t);
13074 if (TREE_CODE (tmp) != LABEL_DECL)
13075 /* Computed goto's must be tsubst'd into. On the other hand,
13076 non-computed gotos must not be; the identifier in question
13077 will have no binding. */
13078 tmp = RECUR (tmp);
13079 else
13080 tmp = DECL_NAME (tmp);
13081 finish_goto_stmt (tmp);
13082 break;
13084 case ASM_EXPR:
13085 tmp = finish_asm_stmt
13086 (ASM_VOLATILE_P (t),
13087 RECUR (ASM_STRING (t)),
13088 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
13089 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
13090 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
13091 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
13093 tree asm_expr = tmp;
13094 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
13095 asm_expr = TREE_OPERAND (asm_expr, 0);
13096 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
13098 break;
13100 case TRY_BLOCK:
13101 if (CLEANUP_P (t))
13103 stmt = begin_try_block ();
13104 RECUR (TRY_STMTS (t));
13105 finish_cleanup_try_block (stmt);
13106 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
13108 else
13110 tree compound_stmt = NULL_TREE;
13112 if (FN_TRY_BLOCK_P (t))
13113 stmt = begin_function_try_block (&compound_stmt);
13114 else
13115 stmt = begin_try_block ();
13117 RECUR (TRY_STMTS (t));
13119 if (FN_TRY_BLOCK_P (t))
13120 finish_function_try_block (stmt);
13121 else
13122 finish_try_block (stmt);
13124 RECUR (TRY_HANDLERS (t));
13125 if (FN_TRY_BLOCK_P (t))
13126 finish_function_handler_sequence (stmt, compound_stmt);
13127 else
13128 finish_handler_sequence (stmt);
13130 break;
13132 case HANDLER:
13134 tree decl = HANDLER_PARMS (t);
13136 if (decl)
13138 decl = tsubst (decl, args, complain, in_decl);
13139 /* Prevent instantiate_decl from trying to instantiate
13140 this variable. We've already done all that needs to be
13141 done. */
13142 if (decl != error_mark_node)
13143 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
13145 stmt = begin_handler ();
13146 finish_handler_parms (decl, stmt);
13147 RECUR (HANDLER_BODY (t));
13148 finish_handler (stmt);
13150 break;
13152 case TAG_DEFN:
13153 tmp = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13154 if (CLASS_TYPE_P (tmp))
13156 /* Local classes are not independent templates; they are
13157 instantiated along with their containing function. And this
13158 way we don't have to deal with pushing out of one local class
13159 to instantiate a member of another local class. */
13160 tree fn;
13161 /* Closures are handled by the LAMBDA_EXPR. */
13162 gcc_assert (!LAMBDA_TYPE_P (TREE_TYPE (t)));
13163 complete_type (tmp);
13164 for (fn = TYPE_METHODS (tmp); fn; fn = DECL_CHAIN (fn))
13165 if (!DECL_ARTIFICIAL (fn))
13166 instantiate_decl (fn, /*defer_ok*/0, /*expl_inst_class*/false);
13168 break;
13170 case STATIC_ASSERT:
13172 tree condition;
13174 ++c_inhibit_evaluation_warnings;
13175 condition =
13176 tsubst_expr (STATIC_ASSERT_CONDITION (t),
13177 args,
13178 complain, in_decl,
13179 /*integral_constant_expression_p=*/true);
13180 --c_inhibit_evaluation_warnings;
13182 finish_static_assert (condition,
13183 STATIC_ASSERT_MESSAGE (t),
13184 STATIC_ASSERT_SOURCE_LOCATION (t),
13185 /*member_p=*/false);
13187 break;
13189 case OMP_PARALLEL:
13190 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
13191 args, complain, in_decl);
13192 stmt = begin_omp_parallel ();
13193 RECUR (OMP_PARALLEL_BODY (t));
13194 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
13195 = OMP_PARALLEL_COMBINED (t);
13196 break;
13198 case OMP_TASK:
13199 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
13200 args, complain, in_decl);
13201 stmt = begin_omp_task ();
13202 RECUR (OMP_TASK_BODY (t));
13203 finish_omp_task (tmp, stmt);
13204 break;
13206 case OMP_FOR:
13208 tree clauses, body, pre_body;
13209 tree declv, initv, condv, incrv;
13210 int i;
13212 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
13213 args, complain, in_decl);
13214 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13215 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13216 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13217 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13219 stmt = begin_omp_structured_block ();
13221 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
13222 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
13223 &clauses, args, complain, in_decl,
13224 integral_constant_expression_p);
13226 pre_body = push_stmt_list ();
13227 RECUR (OMP_FOR_PRE_BODY (t));
13228 pre_body = pop_stmt_list (pre_body);
13230 body = push_stmt_list ();
13231 RECUR (OMP_FOR_BODY (t));
13232 body = pop_stmt_list (body);
13234 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
13235 body, pre_body, clauses);
13237 add_stmt (finish_omp_structured_block (stmt));
13239 break;
13241 case OMP_SECTIONS:
13242 case OMP_SINGLE:
13243 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
13244 stmt = push_stmt_list ();
13245 RECUR (OMP_BODY (t));
13246 stmt = pop_stmt_list (stmt);
13248 t = copy_node (t);
13249 OMP_BODY (t) = stmt;
13250 OMP_CLAUSES (t) = tmp;
13251 add_stmt (t);
13252 break;
13254 case OMP_SECTION:
13255 case OMP_CRITICAL:
13256 case OMP_MASTER:
13257 case OMP_ORDERED:
13258 stmt = push_stmt_list ();
13259 RECUR (OMP_BODY (t));
13260 stmt = pop_stmt_list (stmt);
13262 t = copy_node (t);
13263 OMP_BODY (t) = stmt;
13264 add_stmt (t);
13265 break;
13267 case OMP_ATOMIC:
13268 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
13269 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
13271 tree op1 = TREE_OPERAND (t, 1);
13272 tree rhs1 = NULL_TREE;
13273 tree lhs, rhs;
13274 if (TREE_CODE (op1) == COMPOUND_EXPR)
13276 rhs1 = RECUR (TREE_OPERAND (op1, 0));
13277 op1 = TREE_OPERAND (op1, 1);
13279 lhs = RECUR (TREE_OPERAND (op1, 0));
13280 rhs = RECUR (TREE_OPERAND (op1, 1));
13281 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
13282 NULL_TREE, NULL_TREE, rhs1);
13284 else
13286 tree op1 = TREE_OPERAND (t, 1);
13287 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
13288 tree rhs1 = NULL_TREE;
13289 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
13290 enum tree_code opcode = NOP_EXPR;
13291 if (code == OMP_ATOMIC_READ)
13293 v = RECUR (TREE_OPERAND (op1, 0));
13294 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13296 else if (code == OMP_ATOMIC_CAPTURE_OLD
13297 || code == OMP_ATOMIC_CAPTURE_NEW)
13299 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
13300 v = RECUR (TREE_OPERAND (op1, 0));
13301 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13302 if (TREE_CODE (op11) == COMPOUND_EXPR)
13304 rhs1 = RECUR (TREE_OPERAND (op11, 0));
13305 op11 = TREE_OPERAND (op11, 1);
13307 lhs = RECUR (TREE_OPERAND (op11, 0));
13308 rhs = RECUR (TREE_OPERAND (op11, 1));
13309 opcode = TREE_CODE (op11);
13311 else
13313 code = OMP_ATOMIC;
13314 lhs = RECUR (TREE_OPERAND (op1, 0));
13315 rhs = RECUR (TREE_OPERAND (op1, 1));
13317 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1);
13319 break;
13321 case TRANSACTION_EXPR:
13323 int flags = 0;
13324 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
13325 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
13327 if (TRANSACTION_EXPR_IS_STMT (t))
13329 tree body = TRANSACTION_EXPR_BODY (t);
13330 tree noex = NULL_TREE;
13331 if (TREE_CODE (body) == MUST_NOT_THROW_EXPR)
13333 noex = MUST_NOT_THROW_COND (body);
13334 if (noex == NULL_TREE)
13335 noex = boolean_true_node;
13336 body = TREE_OPERAND (body, 0);
13338 stmt = begin_transaction_stmt (input_location, NULL, flags);
13339 RECUR (body);
13340 finish_transaction_stmt (stmt, NULL, flags, RECUR (noex));
13342 else
13344 stmt = build_transaction_expr (EXPR_LOCATION (t),
13345 RECUR (TRANSACTION_EXPR_BODY (t)),
13346 flags, NULL_TREE);
13347 RETURN (stmt);
13350 break;
13352 case MUST_NOT_THROW_EXPR:
13353 RETURN (build_must_not_throw_expr (RECUR (TREE_OPERAND (t, 0)),
13354 RECUR (MUST_NOT_THROW_COND (t))));
13356 case EXPR_PACK_EXPANSION:
13357 error ("invalid use of pack expansion expression");
13358 RETURN (error_mark_node);
13360 case NONTYPE_ARGUMENT_PACK:
13361 error ("use %<...%> to expand argument pack");
13362 RETURN (error_mark_node);
13364 case COMPOUND_EXPR:
13365 tmp = RECUR (TREE_OPERAND (t, 0));
13366 if (tmp == NULL_TREE)
13367 /* If the first operand was a statement, we're done with it. */
13368 RETURN (RECUR (TREE_OPERAND (t, 1)));
13369 RETURN (build_x_compound_expr (EXPR_LOCATION (t), tmp,
13370 RECUR (TREE_OPERAND (t, 1)),
13371 complain));
13373 default:
13374 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
13376 RETURN (tsubst_copy_and_build (t, args, complain, in_decl,
13377 /*function_p=*/false,
13378 integral_constant_expression_p));
13381 RETURN (NULL_TREE);
13382 out:
13383 input_location = loc;
13384 return r;
13385 #undef RECUR
13386 #undef RETURN
13389 /* T is a postfix-expression that is not being used in a function
13390 call. Return the substituted version of T. */
13392 static tree
13393 tsubst_non_call_postfix_expression (tree t, tree args,
13394 tsubst_flags_t complain,
13395 tree in_decl)
13397 if (TREE_CODE (t) == SCOPE_REF)
13398 t = tsubst_qualified_id (t, args, complain, in_decl,
13399 /*done=*/false, /*address_p=*/false);
13400 else
13401 t = tsubst_copy_and_build (t, args, complain, in_decl,
13402 /*function_p=*/false,
13403 /*integral_constant_expression_p=*/false);
13405 return t;
13408 /* Like tsubst but deals with expressions and performs semantic
13409 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13411 tree
13412 tsubst_copy_and_build (tree t,
13413 tree args,
13414 tsubst_flags_t complain,
13415 tree in_decl,
13416 bool function_p,
13417 bool integral_constant_expression_p)
13419 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
13420 #define RECUR(NODE) \
13421 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13422 /*function_p=*/false, \
13423 integral_constant_expression_p)
13425 tree retval, op1;
13426 location_t loc;
13428 if (t == NULL_TREE || t == error_mark_node)
13429 return t;
13431 loc = input_location;
13432 if (EXPR_HAS_LOCATION (t))
13433 input_location = EXPR_LOCATION (t);
13435 /* N3276 decltype magic only applies to calls at the top level or on the
13436 right side of a comma. */
13437 if (TREE_CODE (t) != CALL_EXPR
13438 && TREE_CODE (t) != COMPOUND_EXPR)
13439 complain &= ~tf_decltype;
13441 switch (TREE_CODE (t))
13443 case USING_DECL:
13444 t = DECL_NAME (t);
13445 /* Fall through. */
13446 case IDENTIFIER_NODE:
13448 tree decl;
13449 cp_id_kind idk;
13450 bool non_integral_constant_expression_p;
13451 const char *error_msg;
13453 if (IDENTIFIER_TYPENAME_P (t))
13455 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13456 t = mangle_conv_op_name_for_type (new_type);
13459 /* Look up the name. */
13460 decl = lookup_name (t);
13462 /* By convention, expressions use ERROR_MARK_NODE to indicate
13463 failure, not NULL_TREE. */
13464 if (decl == NULL_TREE)
13465 decl = error_mark_node;
13467 decl = finish_id_expression (t, decl, NULL_TREE,
13468 &idk,
13469 integral_constant_expression_p,
13470 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx0x),
13471 &non_integral_constant_expression_p,
13472 /*template_p=*/false,
13473 /*done=*/true,
13474 /*address_p=*/false,
13475 /*template_arg_p=*/false,
13476 &error_msg,
13477 input_location);
13478 if (error_msg)
13479 error (error_msg);
13480 if (!function_p && identifier_p (decl))
13482 if (complain & tf_error)
13483 unqualified_name_lookup_error (decl);
13484 decl = error_mark_node;
13486 RETURN (decl);
13489 case TEMPLATE_ID_EXPR:
13491 tree object;
13492 tree templ = RECUR (TREE_OPERAND (t, 0));
13493 tree targs = TREE_OPERAND (t, 1);
13495 if (targs)
13496 targs = tsubst_template_args (targs, args, complain, in_decl);
13498 if (TREE_CODE (templ) == COMPONENT_REF)
13500 object = TREE_OPERAND (templ, 0);
13501 templ = TREE_OPERAND (templ, 1);
13503 else
13504 object = NULL_TREE;
13505 templ = lookup_template_function (templ, targs);
13507 if (object)
13508 RETURN (build3 (COMPONENT_REF, TREE_TYPE (templ),
13509 object, templ, NULL_TREE));
13510 else
13511 RETURN (baselink_for_fns (templ));
13514 case INDIRECT_REF:
13516 tree r = RECUR (TREE_OPERAND (t, 0));
13518 if (REFERENCE_REF_P (t))
13520 /* A type conversion to reference type will be enclosed in
13521 such an indirect ref, but the substitution of the cast
13522 will have also added such an indirect ref. */
13523 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
13524 r = convert_from_reference (r);
13526 else
13527 r = build_x_indirect_ref (input_location, r, RO_UNARY_STAR, complain);
13528 RETURN (r);
13531 case NOP_EXPR:
13532 RETURN (build_nop
13533 (tsubst (TREE_TYPE (t), args, complain, in_decl),
13534 RECUR (TREE_OPERAND (t, 0))));
13536 case IMPLICIT_CONV_EXPR:
13538 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13539 tree expr = RECUR (TREE_OPERAND (t, 0));
13540 int flags = LOOKUP_IMPLICIT;
13541 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
13542 flags = LOOKUP_NORMAL;
13543 RETURN (perform_implicit_conversion_flags (type, expr, complain,
13544 flags));
13547 case CONVERT_EXPR:
13548 RETURN (build1
13549 (CONVERT_EXPR,
13550 tsubst (TREE_TYPE (t), args, complain, in_decl),
13551 RECUR (TREE_OPERAND (t, 0))));
13553 case CAST_EXPR:
13554 case REINTERPRET_CAST_EXPR:
13555 case CONST_CAST_EXPR:
13556 case DYNAMIC_CAST_EXPR:
13557 case STATIC_CAST_EXPR:
13559 tree type;
13560 tree op, r = NULL_TREE;
13562 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13563 if (integral_constant_expression_p
13564 && !cast_valid_in_integral_constant_expression_p (type))
13566 if (complain & tf_error)
13567 error ("a cast to a type other than an integral or "
13568 "enumeration type cannot appear in a constant-expression");
13569 RETURN (error_mark_node);
13572 op = RECUR (TREE_OPERAND (t, 0));
13574 ++c_inhibit_evaluation_warnings;
13575 switch (TREE_CODE (t))
13577 case CAST_EXPR:
13578 r = build_functional_cast (type, op, complain);
13579 break;
13580 case REINTERPRET_CAST_EXPR:
13581 r = build_reinterpret_cast (type, op, complain);
13582 break;
13583 case CONST_CAST_EXPR:
13584 r = build_const_cast (type, op, complain);
13585 break;
13586 case DYNAMIC_CAST_EXPR:
13587 r = build_dynamic_cast (type, op, complain);
13588 break;
13589 case STATIC_CAST_EXPR:
13590 r = build_static_cast (type, op, complain);
13591 break;
13592 default:
13593 gcc_unreachable ();
13595 --c_inhibit_evaluation_warnings;
13597 RETURN (r);
13600 case POSTDECREMENT_EXPR:
13601 case POSTINCREMENT_EXPR:
13602 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13603 args, complain, in_decl);
13604 RETURN (build_x_unary_op (input_location, TREE_CODE (t), op1, complain));
13606 case PREDECREMENT_EXPR:
13607 case PREINCREMENT_EXPR:
13608 case NEGATE_EXPR:
13609 case BIT_NOT_EXPR:
13610 case ABS_EXPR:
13611 case TRUTH_NOT_EXPR:
13612 case UNARY_PLUS_EXPR: /* Unary + */
13613 case REALPART_EXPR:
13614 case IMAGPART_EXPR:
13615 RETURN (build_x_unary_op (input_location, TREE_CODE (t),
13616 RECUR (TREE_OPERAND (t, 0)), complain));
13618 case FIX_TRUNC_EXPR:
13619 RETURN (cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)),
13620 0, complain));
13622 case ADDR_EXPR:
13623 op1 = TREE_OPERAND (t, 0);
13624 if (TREE_CODE (op1) == LABEL_DECL)
13625 RETURN (finish_label_address_expr (DECL_NAME (op1),
13626 EXPR_LOCATION (op1)));
13627 if (TREE_CODE (op1) == SCOPE_REF)
13628 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
13629 /*done=*/true, /*address_p=*/true);
13630 else
13631 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
13632 in_decl);
13633 RETURN (build_x_unary_op (input_location, ADDR_EXPR, op1, complain));
13635 case PLUS_EXPR:
13636 case MINUS_EXPR:
13637 case MULT_EXPR:
13638 case TRUNC_DIV_EXPR:
13639 case CEIL_DIV_EXPR:
13640 case FLOOR_DIV_EXPR:
13641 case ROUND_DIV_EXPR:
13642 case EXACT_DIV_EXPR:
13643 case BIT_AND_EXPR:
13644 case BIT_IOR_EXPR:
13645 case BIT_XOR_EXPR:
13646 case TRUNC_MOD_EXPR:
13647 case FLOOR_MOD_EXPR:
13648 case TRUTH_ANDIF_EXPR:
13649 case TRUTH_ORIF_EXPR:
13650 case TRUTH_AND_EXPR:
13651 case TRUTH_OR_EXPR:
13652 case RSHIFT_EXPR:
13653 case LSHIFT_EXPR:
13654 case RROTATE_EXPR:
13655 case LROTATE_EXPR:
13656 case EQ_EXPR:
13657 case NE_EXPR:
13658 case MAX_EXPR:
13659 case MIN_EXPR:
13660 case LE_EXPR:
13661 case GE_EXPR:
13662 case LT_EXPR:
13663 case GT_EXPR:
13664 case MEMBER_REF:
13665 case DOTSTAR_EXPR:
13667 tree r;
13669 ++c_inhibit_evaluation_warnings;
13671 r = build_x_binary_op
13672 (input_location, TREE_CODE (t),
13673 RECUR (TREE_OPERAND (t, 0)),
13674 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
13675 ? ERROR_MARK
13676 : TREE_CODE (TREE_OPERAND (t, 0))),
13677 RECUR (TREE_OPERAND (t, 1)),
13678 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
13679 ? ERROR_MARK
13680 : TREE_CODE (TREE_OPERAND (t, 1))),
13681 /*overload=*/NULL,
13682 complain);
13683 if (EXPR_P (r) && TREE_NO_WARNING (t))
13684 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13686 --c_inhibit_evaluation_warnings;
13688 RETURN (r);
13691 case SCOPE_REF:
13692 RETURN (tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
13693 /*address_p=*/false));
13694 case ARRAY_REF:
13695 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13696 args, complain, in_decl);
13697 RETURN (build_x_array_ref (EXPR_LOCATION (t), op1,
13698 RECUR (TREE_OPERAND (t, 1)), complain));
13700 case SIZEOF_EXPR:
13701 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
13702 RETURN (tsubst_copy (t, args, complain, in_decl));
13703 /* Fall through */
13705 case ALIGNOF_EXPR:
13707 tree r;
13709 op1 = TREE_OPERAND (t, 0);
13710 if (TREE_CODE (t) == SIZEOF_EXPR && SIZEOF_EXPR_TYPE_P (t))
13711 op1 = TREE_TYPE (op1);
13712 if (!args)
13714 /* When there are no ARGS, we are trying to evaluate a
13715 non-dependent expression from the parser. Trying to do
13716 the substitutions may not work. */
13717 if (!TYPE_P (op1))
13718 op1 = TREE_TYPE (op1);
13720 else
13722 ++cp_unevaluated_operand;
13723 ++c_inhibit_evaluation_warnings;
13724 if (TYPE_P (op1))
13725 op1 = tsubst (op1, args, complain, in_decl);
13726 else
13727 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13728 /*function_p=*/false,
13729 /*integral_constant_expression_p=*/
13730 false);
13731 --cp_unevaluated_operand;
13732 --c_inhibit_evaluation_warnings;
13734 if (TYPE_P (op1))
13735 r = cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
13736 complain & tf_error);
13737 else
13738 r = cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
13739 complain & tf_error);
13740 if (TREE_CODE (t) == SIZEOF_EXPR && r != error_mark_node)
13742 if (TREE_CODE (r) != SIZEOF_EXPR || TYPE_P (op1))
13744 if (!processing_template_decl && TYPE_P (op1))
13746 r = build_min (SIZEOF_EXPR, size_type_node,
13747 build1 (NOP_EXPR, op1, error_mark_node));
13748 SIZEOF_EXPR_TYPE_P (r) = 1;
13750 else
13751 r = build_min (SIZEOF_EXPR, size_type_node, op1);
13752 TREE_SIDE_EFFECTS (r) = 0;
13753 TREE_READONLY (r) = 1;
13755 SET_EXPR_LOCATION (r, EXPR_LOCATION (t));
13757 RETURN (r);
13760 case AT_ENCODE_EXPR:
13762 op1 = TREE_OPERAND (t, 0);
13763 ++cp_unevaluated_operand;
13764 ++c_inhibit_evaluation_warnings;
13765 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13766 /*function_p=*/false,
13767 /*integral_constant_expression_p=*/false);
13768 --cp_unevaluated_operand;
13769 --c_inhibit_evaluation_warnings;
13770 RETURN (objc_build_encode_expr (op1));
13773 case NOEXCEPT_EXPR:
13774 op1 = TREE_OPERAND (t, 0);
13775 ++cp_unevaluated_operand;
13776 ++c_inhibit_evaluation_warnings;
13777 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13778 /*function_p=*/false,
13779 /*integral_constant_expression_p=*/false);
13780 --cp_unevaluated_operand;
13781 --c_inhibit_evaluation_warnings;
13782 RETURN (finish_noexcept_expr (op1, complain));
13784 case MODOP_EXPR:
13786 tree r = build_x_modify_expr
13787 (EXPR_LOCATION (t),
13788 RECUR (TREE_OPERAND (t, 0)),
13789 TREE_CODE (TREE_OPERAND (t, 1)),
13790 RECUR (TREE_OPERAND (t, 2)),
13791 complain);
13792 /* TREE_NO_WARNING must be set if either the expression was
13793 parenthesized or it uses an operator such as >>= rather
13794 than plain assignment. In the former case, it was already
13795 set and must be copied. In the latter case,
13796 build_x_modify_expr sets it and it must not be reset
13797 here. */
13798 if (TREE_NO_WARNING (t))
13799 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13800 RETURN (r);
13803 case ARROW_EXPR:
13804 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13805 args, complain, in_decl);
13806 /* Remember that there was a reference to this entity. */
13807 if (DECL_P (op1))
13808 mark_used (op1);
13809 RETURN (build_x_arrow (input_location, op1, complain));
13811 case NEW_EXPR:
13813 tree placement = RECUR (TREE_OPERAND (t, 0));
13814 tree init = RECUR (TREE_OPERAND (t, 3));
13815 vec<tree, va_gc> *placement_vec;
13816 vec<tree, va_gc> *init_vec;
13817 tree ret;
13819 if (placement == NULL_TREE)
13820 placement_vec = NULL;
13821 else
13823 placement_vec = make_tree_vector ();
13824 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
13825 vec_safe_push (placement_vec, TREE_VALUE (placement));
13828 /* If there was an initializer in the original tree, but it
13829 instantiated to an empty list, then we should pass a
13830 non-NULL empty vector to tell build_new that it was an
13831 empty initializer() rather than no initializer. This can
13832 only happen when the initializer is a pack expansion whose
13833 parameter packs are of length zero. */
13834 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
13835 init_vec = NULL;
13836 else
13838 init_vec = make_tree_vector ();
13839 if (init == void_zero_node)
13840 gcc_assert (init_vec != NULL);
13841 else
13843 for (; init != NULL_TREE; init = TREE_CHAIN (init))
13844 vec_safe_push (init_vec, TREE_VALUE (init));
13848 ret = build_new (&placement_vec,
13849 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
13850 RECUR (TREE_OPERAND (t, 2)),
13851 &init_vec,
13852 NEW_EXPR_USE_GLOBAL (t),
13853 complain);
13855 if (placement_vec != NULL)
13856 release_tree_vector (placement_vec);
13857 if (init_vec != NULL)
13858 release_tree_vector (init_vec);
13860 RETURN (ret);
13863 case DELETE_EXPR:
13864 RETURN (delete_sanity
13865 (RECUR (TREE_OPERAND (t, 0)),
13866 RECUR (TREE_OPERAND (t, 1)),
13867 DELETE_EXPR_USE_VEC (t),
13868 DELETE_EXPR_USE_GLOBAL (t),
13869 complain));
13871 case COMPOUND_EXPR:
13873 tree op0 = tsubst_copy_and_build (TREE_OPERAND (t, 0), args,
13874 complain & ~tf_decltype, in_decl,
13875 /*function_p=*/false,
13876 integral_constant_expression_p);
13877 RETURN (build_x_compound_expr (EXPR_LOCATION (t),
13878 op0,
13879 RECUR (TREE_OPERAND (t, 1)),
13880 complain));
13883 case CALL_EXPR:
13885 tree function;
13886 vec<tree, va_gc> *call_args;
13887 unsigned int nargs, i;
13888 bool qualified_p;
13889 bool koenig_p;
13890 tree ret;
13892 /* Don't pass tf_decltype down to subexpressions. */
13893 tsubst_flags_t decltype_flag = (complain & tf_decltype);
13894 complain &= ~tf_decltype;
13896 function = CALL_EXPR_FN (t);
13897 /* When we parsed the expression, we determined whether or
13898 not Koenig lookup should be performed. */
13899 koenig_p = KOENIG_LOOKUP_P (t);
13900 if (TREE_CODE (function) == SCOPE_REF)
13902 qualified_p = true;
13903 function = tsubst_qualified_id (function, args, complain, in_decl,
13904 /*done=*/false,
13905 /*address_p=*/false);
13907 else if (koenig_p && identifier_p (function))
13909 /* Do nothing; calling tsubst_copy_and_build on an identifier
13910 would incorrectly perform unqualified lookup again.
13912 Note that we can also have an IDENTIFIER_NODE if the earlier
13913 unqualified lookup found a member function; in that case
13914 koenig_p will be false and we do want to do the lookup
13915 again to find the instantiated member function.
13917 FIXME but doing that causes c++/15272, so we need to stop
13918 using IDENTIFIER_NODE in that situation. */
13919 qualified_p = false;
13921 else
13923 if (TREE_CODE (function) == COMPONENT_REF)
13925 tree op = TREE_OPERAND (function, 1);
13927 qualified_p = (TREE_CODE (op) == SCOPE_REF
13928 || (BASELINK_P (op)
13929 && BASELINK_QUALIFIED_P (op)));
13931 else
13932 qualified_p = false;
13934 if (TREE_CODE (function) == ADDR_EXPR
13935 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
13936 /* Avoid error about taking the address of a constructor. */
13937 function = TREE_OPERAND (function, 0);
13939 function = tsubst_copy_and_build (function, args, complain,
13940 in_decl,
13941 !qualified_p,
13942 integral_constant_expression_p);
13944 if (BASELINK_P (function))
13945 qualified_p = true;
13948 nargs = call_expr_nargs (t);
13949 call_args = make_tree_vector ();
13950 for (i = 0; i < nargs; ++i)
13952 tree arg = CALL_EXPR_ARG (t, i);
13954 if (!PACK_EXPANSION_P (arg))
13955 vec_safe_push (call_args, RECUR (CALL_EXPR_ARG (t, i)));
13956 else
13958 /* Expand the pack expansion and push each entry onto
13959 CALL_ARGS. */
13960 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13961 if (TREE_CODE (arg) == TREE_VEC)
13963 unsigned int len, j;
13965 len = TREE_VEC_LENGTH (arg);
13966 for (j = 0; j < len; ++j)
13968 tree value = TREE_VEC_ELT (arg, j);
13969 if (value != NULL_TREE)
13970 value = convert_from_reference (value);
13971 vec_safe_push (call_args, value);
13974 else
13976 /* A partial substitution. Add one entry. */
13977 vec_safe_push (call_args, arg);
13982 /* We do not perform argument-dependent lookup if normal
13983 lookup finds a non-function, in accordance with the
13984 expected resolution of DR 218. */
13985 if (koenig_p
13986 && ((is_overloaded_fn (function)
13987 /* If lookup found a member function, the Koenig lookup is
13988 not appropriate, even if an unqualified-name was used
13989 to denote the function. */
13990 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13991 || identifier_p (function))
13992 /* Only do this when substitution turns a dependent call
13993 into a non-dependent call. */
13994 && type_dependent_expression_p_push (t)
13995 && !any_type_dependent_arguments_p (call_args))
13996 function = perform_koenig_lookup (function, call_args, false,
13997 tf_none);
13999 if (identifier_p (function)
14000 && !any_type_dependent_arguments_p (call_args))
14002 if (koenig_p && (complain & tf_warning_or_error))
14004 /* For backwards compatibility and good diagnostics, try
14005 the unqualified lookup again if we aren't in SFINAE
14006 context. */
14007 tree unq = (tsubst_copy_and_build
14008 (function, args, complain, in_decl, true,
14009 integral_constant_expression_p));
14010 if (unq == error_mark_node)
14011 RETURN (error_mark_node);
14013 if (unq != function)
14015 tree fn = unq;
14016 if (TREE_CODE (fn) == INDIRECT_REF)
14017 fn = TREE_OPERAND (fn, 0);
14018 if (TREE_CODE (fn) == COMPONENT_REF)
14019 fn = TREE_OPERAND (fn, 1);
14020 if (is_overloaded_fn (fn))
14021 fn = get_first_fn (fn);
14022 permerror (EXPR_LOC_OR_HERE (t),
14023 "%qD was not declared in this scope, "
14024 "and no declarations were found by "
14025 "argument-dependent lookup at the point "
14026 "of instantiation", function);
14027 if (!DECL_P (fn))
14028 /* Can't say anything more. */;
14029 else if (DECL_CLASS_SCOPE_P (fn))
14031 inform (EXPR_LOC_OR_HERE (t),
14032 "declarations in dependent base %qT are "
14033 "not found by unqualified lookup",
14034 DECL_CLASS_CONTEXT (fn));
14035 if (current_class_ptr)
14036 inform (EXPR_LOC_OR_HERE (t),
14037 "use %<this->%D%> instead", function);
14038 else
14039 inform (EXPR_LOC_OR_HERE (t),
14040 "use %<%T::%D%> instead",
14041 current_class_name, function);
14043 else
14044 inform (0, "%q+D declared here, later in the "
14045 "translation unit", fn);
14046 function = unq;
14049 if (identifier_p (function))
14051 if (complain & tf_error)
14052 unqualified_name_lookup_error (function);
14053 release_tree_vector (call_args);
14054 RETURN (error_mark_node);
14058 /* Remember that there was a reference to this entity. */
14059 if (DECL_P (function))
14060 mark_used (function);
14062 /* Put back tf_decltype for the actual call. */
14063 complain |= decltype_flag;
14065 if (TREE_CODE (function) == OFFSET_REF)
14066 ret = build_offset_ref_call_from_tree (function, &call_args,
14067 complain);
14068 else if (TREE_CODE (function) == COMPONENT_REF)
14070 tree instance = TREE_OPERAND (function, 0);
14071 tree fn = TREE_OPERAND (function, 1);
14073 if (processing_template_decl
14074 && (type_dependent_expression_p (instance)
14075 || (!BASELINK_P (fn)
14076 && TREE_CODE (fn) != FIELD_DECL)
14077 || type_dependent_expression_p (fn)
14078 || any_type_dependent_arguments_p (call_args)))
14079 ret = build_nt_call_vec (function, call_args);
14080 else if (!BASELINK_P (fn))
14081 ret = finish_call_expr (function, &call_args,
14082 /*disallow_virtual=*/false,
14083 /*koenig_p=*/false,
14084 complain);
14085 else
14086 ret = (build_new_method_call
14087 (instance, fn,
14088 &call_args, NULL_TREE,
14089 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
14090 /*fn_p=*/NULL,
14091 complain));
14093 else
14094 ret = finish_call_expr (function, &call_args,
14095 /*disallow_virtual=*/qualified_p,
14096 koenig_p,
14097 complain);
14099 release_tree_vector (call_args);
14101 RETURN (ret);
14104 case COND_EXPR:
14106 tree cond = RECUR (TREE_OPERAND (t, 0));
14107 tree exp1, exp2;
14109 if (TREE_CODE (cond) == INTEGER_CST)
14111 if (integer_zerop (cond))
14113 ++c_inhibit_evaluation_warnings;
14114 exp1 = RECUR (TREE_OPERAND (t, 1));
14115 --c_inhibit_evaluation_warnings;
14116 exp2 = RECUR (TREE_OPERAND (t, 2));
14118 else
14120 exp1 = RECUR (TREE_OPERAND (t, 1));
14121 ++c_inhibit_evaluation_warnings;
14122 exp2 = RECUR (TREE_OPERAND (t, 2));
14123 --c_inhibit_evaluation_warnings;
14126 else
14128 exp1 = RECUR (TREE_OPERAND (t, 1));
14129 exp2 = RECUR (TREE_OPERAND (t, 2));
14132 RETURN (build_x_conditional_expr (EXPR_LOCATION (t),
14133 cond, exp1, exp2, complain));
14136 case PSEUDO_DTOR_EXPR:
14137 RETURN (finish_pseudo_destructor_expr
14138 (RECUR (TREE_OPERAND (t, 0)),
14139 RECUR (TREE_OPERAND (t, 1)),
14140 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl)));
14142 case TREE_LIST:
14144 tree purpose, value, chain;
14146 if (t == void_list_node)
14147 RETURN (t);
14149 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
14150 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
14152 /* We have pack expansions, so expand those and
14153 create a new list out of it. */
14154 tree purposevec = NULL_TREE;
14155 tree valuevec = NULL_TREE;
14156 tree chain;
14157 int i, len = -1;
14159 /* Expand the argument expressions. */
14160 if (TREE_PURPOSE (t))
14161 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
14162 complain, in_decl);
14163 if (TREE_VALUE (t))
14164 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
14165 complain, in_decl);
14167 /* Build the rest of the list. */
14168 chain = TREE_CHAIN (t);
14169 if (chain && chain != void_type_node)
14170 chain = RECUR (chain);
14172 /* Determine the number of arguments. */
14173 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
14175 len = TREE_VEC_LENGTH (purposevec);
14176 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
14178 else if (TREE_CODE (valuevec) == TREE_VEC)
14179 len = TREE_VEC_LENGTH (valuevec);
14180 else
14182 /* Since we only performed a partial substitution into
14183 the argument pack, we only RETURN (a single list
14184 node. */
14185 if (purposevec == TREE_PURPOSE (t)
14186 && valuevec == TREE_VALUE (t)
14187 && chain == TREE_CHAIN (t))
14188 RETURN (t);
14190 RETURN (tree_cons (purposevec, valuevec, chain));
14193 /* Convert the argument vectors into a TREE_LIST */
14194 i = len;
14195 while (i > 0)
14197 /* Grab the Ith values. */
14198 i--;
14199 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
14200 : NULL_TREE;
14201 value
14202 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
14203 : NULL_TREE;
14205 /* Build the list (backwards). */
14206 chain = tree_cons (purpose, value, chain);
14209 RETURN (chain);
14212 purpose = TREE_PURPOSE (t);
14213 if (purpose)
14214 purpose = RECUR (purpose);
14215 value = TREE_VALUE (t);
14216 if (value)
14217 value = RECUR (value);
14218 chain = TREE_CHAIN (t);
14219 if (chain && chain != void_type_node)
14220 chain = RECUR (chain);
14221 if (purpose == TREE_PURPOSE (t)
14222 && value == TREE_VALUE (t)
14223 && chain == TREE_CHAIN (t))
14224 RETURN (t);
14225 RETURN (tree_cons (purpose, value, chain));
14228 case COMPONENT_REF:
14230 tree object;
14231 tree object_type;
14232 tree member;
14234 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
14235 args, complain, in_decl);
14236 /* Remember that there was a reference to this entity. */
14237 if (DECL_P (object))
14238 mark_used (object);
14239 object_type = TREE_TYPE (object);
14241 member = TREE_OPERAND (t, 1);
14242 if (BASELINK_P (member))
14243 member = tsubst_baselink (member,
14244 non_reference (TREE_TYPE (object)),
14245 args, complain, in_decl);
14246 else
14247 member = tsubst_copy (member, args, complain, in_decl);
14248 if (member == error_mark_node)
14249 RETURN (error_mark_node);
14251 if (type_dependent_expression_p (object))
14252 /* We can't do much here. */;
14253 else if (!CLASS_TYPE_P (object_type))
14255 if (scalarish_type_p (object_type))
14257 tree s = NULL_TREE;
14258 tree dtor = member;
14260 if (TREE_CODE (dtor) == SCOPE_REF)
14262 s = TREE_OPERAND (dtor, 0);
14263 dtor = TREE_OPERAND (dtor, 1);
14265 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
14267 dtor = TREE_OPERAND (dtor, 0);
14268 if (TYPE_P (dtor))
14269 RETURN (finish_pseudo_destructor_expr (object, s, dtor));
14273 else if (TREE_CODE (member) == SCOPE_REF
14274 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
14276 /* Lookup the template functions now that we know what the
14277 scope is. */
14278 tree scope = TREE_OPERAND (member, 0);
14279 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
14280 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
14281 member = lookup_qualified_name (scope, tmpl,
14282 /*is_type_p=*/false,
14283 /*complain=*/false);
14284 if (BASELINK_P (member))
14286 BASELINK_FUNCTIONS (member)
14287 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
14288 args);
14289 member = (adjust_result_of_qualified_name_lookup
14290 (member, BINFO_TYPE (BASELINK_BINFO (member)),
14291 object_type));
14293 else
14295 qualified_name_lookup_error (scope, tmpl, member,
14296 input_location);
14297 RETURN (error_mark_node);
14300 else if (TREE_CODE (member) == SCOPE_REF
14301 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
14302 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
14304 if (complain & tf_error)
14306 if (TYPE_P (TREE_OPERAND (member, 0)))
14307 error ("%qT is not a class or namespace",
14308 TREE_OPERAND (member, 0));
14309 else
14310 error ("%qD is not a class or namespace",
14311 TREE_OPERAND (member, 0));
14313 RETURN (error_mark_node);
14315 else if (TREE_CODE (member) == FIELD_DECL)
14316 RETURN (finish_non_static_data_member (member, object, NULL_TREE));
14318 RETURN (finish_class_member_access_expr (object, member,
14319 /*template_p=*/false,
14320 complain));
14323 case THROW_EXPR:
14324 RETURN (build_throw
14325 (RECUR (TREE_OPERAND (t, 0))));
14327 case CONSTRUCTOR:
14329 vec<constructor_elt, va_gc> *n;
14330 constructor_elt *ce;
14331 unsigned HOST_WIDE_INT idx;
14332 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14333 bool process_index_p;
14334 int newlen;
14335 bool need_copy_p = false;
14336 tree r;
14338 if (type == error_mark_node)
14339 RETURN (error_mark_node);
14341 /* digest_init will do the wrong thing if we let it. */
14342 if (type && TYPE_PTRMEMFUNC_P (type))
14343 RETURN (t);
14345 /* We do not want to process the index of aggregate
14346 initializers as they are identifier nodes which will be
14347 looked up by digest_init. */
14348 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
14350 n = vec_safe_copy (CONSTRUCTOR_ELTS (t));
14351 newlen = vec_safe_length (n);
14352 FOR_EACH_VEC_SAFE_ELT (n, idx, ce)
14354 if (ce->index && process_index_p)
14355 ce->index = RECUR (ce->index);
14357 if (PACK_EXPANSION_P (ce->value))
14359 /* Substitute into the pack expansion. */
14360 ce->value = tsubst_pack_expansion (ce->value, args, complain,
14361 in_decl);
14363 if (ce->value == error_mark_node
14364 || PACK_EXPANSION_P (ce->value))
14366 else if (TREE_VEC_LENGTH (ce->value) == 1)
14367 /* Just move the argument into place. */
14368 ce->value = TREE_VEC_ELT (ce->value, 0);
14369 else
14371 /* Update the length of the final CONSTRUCTOR
14372 arguments vector, and note that we will need to
14373 copy.*/
14374 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
14375 need_copy_p = true;
14378 else
14379 ce->value = RECUR (ce->value);
14382 if (need_copy_p)
14384 vec<constructor_elt, va_gc> *old_n = n;
14386 vec_alloc (n, newlen);
14387 FOR_EACH_VEC_ELT (*old_n, idx, ce)
14389 if (TREE_CODE (ce->value) == TREE_VEC)
14391 int i, len = TREE_VEC_LENGTH (ce->value);
14392 for (i = 0; i < len; ++i)
14393 CONSTRUCTOR_APPEND_ELT (n, 0,
14394 TREE_VEC_ELT (ce->value, i));
14396 else
14397 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
14401 r = build_constructor (init_list_type_node, n);
14402 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
14404 if (TREE_HAS_CONSTRUCTOR (t))
14405 RETURN (finish_compound_literal (type, r, complain));
14407 TREE_TYPE (r) = type;
14408 RETURN (r);
14411 case TYPEID_EXPR:
14413 tree operand_0 = TREE_OPERAND (t, 0);
14414 if (TYPE_P (operand_0))
14416 operand_0 = tsubst (operand_0, args, complain, in_decl);
14417 RETURN (get_typeid (operand_0, complain));
14419 else
14421 operand_0 = RECUR (operand_0);
14422 RETURN (build_typeid (operand_0, complain));
14426 case VAR_DECL:
14427 if (!args)
14428 RETURN (t);
14429 /* Fall through */
14431 case PARM_DECL:
14433 tree r = tsubst_copy (t, args, complain, in_decl);
14435 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
14436 /* If the original type was a reference, we'll be wrapped in
14437 the appropriate INDIRECT_REF. */
14438 r = convert_from_reference (r);
14439 RETURN (r);
14442 case VA_ARG_EXPR:
14443 RETURN (build_x_va_arg (EXPR_LOCATION (t),
14444 RECUR (TREE_OPERAND (t, 0)),
14445 tsubst (TREE_TYPE (t), args, complain, in_decl)));
14447 case OFFSETOF_EXPR:
14448 RETURN (finish_offsetof (RECUR (TREE_OPERAND (t, 0))));
14450 case TRAIT_EXPR:
14452 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
14453 complain, in_decl);
14455 tree type2 = TRAIT_EXPR_TYPE2 (t);
14456 if (type2)
14457 type2 = tsubst_copy (type2, args, complain, in_decl);
14459 RETURN (finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2));
14462 case STMT_EXPR:
14464 tree old_stmt_expr = cur_stmt_expr;
14465 tree stmt_expr = begin_stmt_expr ();
14467 cur_stmt_expr = stmt_expr;
14468 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
14469 integral_constant_expression_p);
14470 stmt_expr = finish_stmt_expr (stmt_expr, false);
14471 cur_stmt_expr = old_stmt_expr;
14473 /* If the resulting list of expression statement is empty,
14474 fold it further into void_zero_node. */
14475 if (empty_expr_stmt_p (stmt_expr))
14476 stmt_expr = void_zero_node;
14478 RETURN (stmt_expr);
14481 case LAMBDA_EXPR:
14483 tree r = build_lambda_expr ();
14485 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
14486 LAMBDA_EXPR_CLOSURE (r) = type;
14487 CLASSTYPE_LAMBDA_EXPR (type) = r;
14489 LAMBDA_EXPR_LOCATION (r)
14490 = LAMBDA_EXPR_LOCATION (t);
14491 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
14492 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
14493 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
14494 LAMBDA_EXPR_DISCRIMINATOR (r)
14495 = (LAMBDA_EXPR_DISCRIMINATOR (t));
14496 /* For a function scope, we want to use tsubst so that we don't
14497 complain about referring to an auto function before its return
14498 type has been deduced. Otherwise, we want to use tsubst_copy so
14499 that we look up the existing field/parameter/variable rather
14500 than build a new one. */
14501 tree scope = LAMBDA_EXPR_EXTRA_SCOPE (t);
14502 if (scope && TREE_CODE (scope) == FUNCTION_DECL)
14503 scope = tsubst (scope, args, complain, in_decl);
14504 else if (scope && TREE_CODE (scope) == PARM_DECL)
14506 /* Look up the parameter we want directly, as tsubst_copy
14507 doesn't do what we need. */
14508 tree fn = tsubst (DECL_CONTEXT (scope), args, complain, in_decl);
14509 tree parm = FUNCTION_FIRST_USER_PARM (fn);
14510 while (DECL_PARM_INDEX (parm) != DECL_PARM_INDEX (scope))
14511 parm = DECL_CHAIN (parm);
14512 scope = parm;
14513 /* FIXME Work around the parm not having DECL_CONTEXT set. */
14514 if (DECL_CONTEXT (scope) == NULL_TREE)
14515 DECL_CONTEXT (scope) = fn;
14517 else
14518 scope = RECUR (scope);
14519 LAMBDA_EXPR_EXTRA_SCOPE (r) = scope;
14520 LAMBDA_EXPR_RETURN_TYPE (r)
14521 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
14523 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
14524 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
14526 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14527 determine_visibility (TYPE_NAME (type));
14528 /* Now that we know visibility, instantiate the type so we have a
14529 declaration of the op() for later calls to lambda_function. */
14530 complete_type (type);
14532 LAMBDA_EXPR_THIS_CAPTURE (r) = NULL_TREE;
14534 RETURN (build_lambda_object (r));
14537 case TARGET_EXPR:
14538 /* We can get here for a constant initializer of non-dependent type.
14539 FIXME stop folding in cp_parser_initializer_clause. */
14541 tree r = get_target_expr_sfinae (RECUR (TARGET_EXPR_INITIAL (t)),
14542 complain);
14543 RETURN (r);
14546 case TRANSACTION_EXPR:
14547 RETURN (tsubst_expr(t, args, complain, in_decl,
14548 integral_constant_expression_p));
14550 default:
14551 /* Handle Objective-C++ constructs, if appropriate. */
14553 tree subst
14554 = objcp_tsubst_copy_and_build (t, args, complain,
14555 in_decl, /*function_p=*/false);
14556 if (subst)
14557 RETURN (subst);
14559 RETURN (tsubst_copy (t, args, complain, in_decl));
14562 #undef RECUR
14563 #undef RETURN
14564 out:
14565 input_location = loc;
14566 return retval;
14569 /* Verify that the instantiated ARGS are valid. For type arguments,
14570 make sure that the type's linkage is ok. For non-type arguments,
14571 make sure they are constants if they are integral or enumerations.
14572 Emit an error under control of COMPLAIN, and return TRUE on error. */
14574 static bool
14575 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
14577 if (dependent_template_arg_p (t))
14578 return false;
14579 if (ARGUMENT_PACK_P (t))
14581 tree vec = ARGUMENT_PACK_ARGS (t);
14582 int len = TREE_VEC_LENGTH (vec);
14583 bool result = false;
14584 int i;
14586 for (i = 0; i < len; ++i)
14587 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
14588 result = true;
14589 return result;
14591 else if (TYPE_P (t))
14593 /* [basic.link]: A name with no linkage (notably, the name
14594 of a class or enumeration declared in a local scope)
14595 shall not be used to declare an entity with linkage.
14596 This implies that names with no linkage cannot be used as
14597 template arguments
14599 DR 757 relaxes this restriction for C++0x. */
14600 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
14601 : no_linkage_check (t, /*relaxed_p=*/false));
14603 if (nt)
14605 /* DR 488 makes use of a type with no linkage cause
14606 type deduction to fail. */
14607 if (complain & tf_error)
14609 if (TYPE_ANONYMOUS_P (nt))
14610 error ("%qT is/uses anonymous type", t);
14611 else
14612 error ("template argument for %qD uses local type %qT",
14613 tmpl, t);
14615 return true;
14617 /* In order to avoid all sorts of complications, we do not
14618 allow variably-modified types as template arguments. */
14619 else if (variably_modified_type_p (t, NULL_TREE))
14621 if (complain & tf_error)
14622 error ("%qT is a variably modified type", t);
14623 return true;
14626 /* Class template and alias template arguments should be OK. */
14627 else if (DECL_TYPE_TEMPLATE_P (t))
14629 /* A non-type argument of integral or enumerated type must be a
14630 constant. */
14631 else if (TREE_TYPE (t)
14632 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
14633 && !TREE_CONSTANT (t))
14635 if (complain & tf_error)
14636 error ("integral expression %qE is not constant", t);
14637 return true;
14639 return false;
14642 static bool
14643 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
14645 int ix, len = DECL_NTPARMS (tmpl);
14646 bool result = false;
14648 for (ix = 0; ix != len; ix++)
14650 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
14651 result = true;
14653 if (result && (complain & tf_error))
14654 error (" trying to instantiate %qD", tmpl);
14655 return result;
14658 /* We're out of SFINAE context now, so generate diagnostics for the access
14659 errors we saw earlier when instantiating D from TMPL and ARGS. */
14661 static void
14662 recheck_decl_substitution (tree d, tree tmpl, tree args)
14664 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
14665 tree type = TREE_TYPE (pattern);
14666 location_t loc = input_location;
14668 push_access_scope (d);
14669 push_deferring_access_checks (dk_no_deferred);
14670 input_location = DECL_SOURCE_LOCATION (pattern);
14671 tsubst (type, args, tf_warning_or_error, d);
14672 input_location = loc;
14673 pop_deferring_access_checks ();
14674 pop_access_scope (d);
14677 /* Instantiate the indicated variable, function, or alias template TMPL with
14678 the template arguments in TARG_PTR. */
14680 static tree
14681 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
14683 tree targ_ptr = orig_args;
14684 tree fndecl;
14685 tree gen_tmpl;
14686 tree spec;
14687 bool access_ok = true;
14689 if (tmpl == error_mark_node)
14690 return error_mark_node;
14692 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
14694 /* If this function is a clone, handle it specially. */
14695 if (DECL_CLONED_FUNCTION_P (tmpl))
14697 tree spec;
14698 tree clone;
14700 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14701 DECL_CLONED_FUNCTION. */
14702 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
14703 targ_ptr, complain);
14704 if (spec == error_mark_node)
14705 return error_mark_node;
14707 /* Look for the clone. */
14708 FOR_EACH_CLONE (clone, spec)
14709 if (DECL_NAME (clone) == DECL_NAME (tmpl))
14710 return clone;
14711 /* We should always have found the clone by now. */
14712 gcc_unreachable ();
14713 return NULL_TREE;
14716 /* Check to see if we already have this specialization. */
14717 gen_tmpl = most_general_template (tmpl);
14718 if (tmpl != gen_tmpl)
14719 /* The TMPL is a partial instantiation. To get a full set of
14720 arguments we must add the arguments used to perform the
14721 partial instantiation. */
14722 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
14723 targ_ptr);
14725 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14726 but it doesn't seem to be on the hot path. */
14727 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
14729 gcc_assert (tmpl == gen_tmpl
14730 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
14731 == spec)
14732 || fndecl == NULL_TREE);
14734 if (spec != NULL_TREE)
14736 if (FNDECL_HAS_ACCESS_ERRORS (spec))
14738 if (complain & tf_error)
14739 recheck_decl_substitution (spec, gen_tmpl, targ_ptr);
14740 return error_mark_node;
14742 return spec;
14745 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
14746 complain))
14747 return error_mark_node;
14749 /* We are building a FUNCTION_DECL, during which the access of its
14750 parameters and return types have to be checked. However this
14751 FUNCTION_DECL which is the desired context for access checking
14752 is not built yet. We solve this chicken-and-egg problem by
14753 deferring all checks until we have the FUNCTION_DECL. */
14754 push_deferring_access_checks (dk_deferred);
14756 /* Instantiation of the function happens in the context of the function
14757 template, not the context of the overload resolution we're doing. */
14758 push_to_top_level ();
14759 /* If there are dependent arguments, e.g. because we're doing partial
14760 ordering, make sure processing_template_decl stays set. */
14761 if (uses_template_parms (targ_ptr))
14762 ++processing_template_decl;
14763 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14765 tree ctx = tsubst (DECL_CONTEXT (gen_tmpl), targ_ptr,
14766 complain, gen_tmpl);
14767 push_nested_class (ctx);
14769 /* Substitute template parameters to obtain the specialization. */
14770 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
14771 targ_ptr, complain, gen_tmpl);
14772 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14773 pop_nested_class ();
14774 pop_from_top_level ();
14776 if (fndecl == error_mark_node)
14778 pop_deferring_access_checks ();
14779 return error_mark_node;
14782 /* The DECL_TI_TEMPLATE should always be the immediate parent
14783 template, not the most general template. */
14784 DECL_TI_TEMPLATE (fndecl) = tmpl;
14786 /* Now we know the specialization, compute access previously
14787 deferred. */
14788 push_access_scope (fndecl);
14789 if (!perform_deferred_access_checks (complain))
14790 access_ok = false;
14791 pop_access_scope (fndecl);
14792 pop_deferring_access_checks ();
14794 /* If we've just instantiated the main entry point for a function,
14795 instantiate all the alternate entry points as well. We do this
14796 by cloning the instantiation of the main entry point, not by
14797 instantiating the template clones. */
14798 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
14799 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
14801 if (!access_ok)
14803 if (!(complain & tf_error))
14805 /* Remember to reinstantiate when we're out of SFINAE so the user
14806 can see the errors. */
14807 FNDECL_HAS_ACCESS_ERRORS (fndecl) = true;
14809 return error_mark_node;
14811 return fndecl;
14814 /* Wrapper for instantiate_template_1. */
14816 tree
14817 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
14819 tree ret;
14820 timevar_push (TV_TEMPLATE_INST);
14821 ret = instantiate_template_1 (tmpl, orig_args, complain);
14822 timevar_pop (TV_TEMPLATE_INST);
14823 return ret;
14826 /* Instantiate the alias template TMPL with ARGS. Also push a template
14827 instantiation level, which instantiate_template doesn't do because
14828 functions and variables have sufficient context established by the
14829 callers. */
14831 static tree
14832 instantiate_alias_template (tree tmpl, tree args, tsubst_flags_t complain)
14834 struct pending_template *old_last_pend = last_pending_template;
14835 struct tinst_level *old_error_tinst = last_error_tinst_level;
14836 if (tmpl == error_mark_node || args == error_mark_node)
14837 return error_mark_node;
14838 tree tinst = build_tree_list (tmpl, args);
14839 if (!push_tinst_level (tinst))
14841 ggc_free (tinst);
14842 return error_mark_node;
14845 args =
14846 coerce_innermost_template_parms (DECL_TEMPLATE_PARMS (tmpl),
14847 args, tmpl, complain,
14848 /*require_all_args=*/true,
14849 /*use_default_args=*/true);
14851 tree r = instantiate_template (tmpl, args, complain);
14852 pop_tinst_level ();
14853 /* We can't free this if a pending_template entry or last_error_tinst_level
14854 is pointing at it. */
14855 if (last_pending_template == old_last_pend
14856 && last_error_tinst_level == old_error_tinst)
14857 ggc_free (tinst);
14859 return r;
14862 /* PARM is a template parameter pack for FN. Returns true iff
14863 PARM is used in a deducible way in the argument list of FN. */
14865 static bool
14866 pack_deducible_p (tree parm, tree fn)
14868 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
14869 for (; t; t = TREE_CHAIN (t))
14871 tree type = TREE_VALUE (t);
14872 tree packs;
14873 if (!PACK_EXPANSION_P (type))
14874 continue;
14875 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
14876 packs; packs = TREE_CHAIN (packs))
14877 if (TREE_VALUE (packs) == parm)
14879 /* The template parameter pack is used in a function parameter
14880 pack. If this is the end of the parameter list, the
14881 template parameter pack is deducible. */
14882 if (TREE_CHAIN (t) == void_list_node)
14883 return true;
14884 else
14885 /* Otherwise, not. Well, it could be deduced from
14886 a non-pack parameter, but doing so would end up with
14887 a deduction mismatch, so don't bother. */
14888 return false;
14891 /* The template parameter pack isn't used in any function parameter
14892 packs, but it might be used deeper, e.g. tuple<Args...>. */
14893 return true;
14896 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14897 NARGS elements of the arguments that are being used when calling
14898 it. TARGS is a vector into which the deduced template arguments
14899 are placed.
14901 Return zero for success, 2 for an incomplete match that doesn't resolve
14902 all the types, and 1 for complete failure. An error message will be
14903 printed only for an incomplete match.
14905 If FN is a conversion operator, or we are trying to produce a specific
14906 specialization, RETURN_TYPE is the return type desired.
14908 The EXPLICIT_TARGS are explicit template arguments provided via a
14909 template-id.
14911 The parameter STRICT is one of:
14913 DEDUCE_CALL:
14914 We are deducing arguments for a function call, as in
14915 [temp.deduct.call].
14917 DEDUCE_CONV:
14918 We are deducing arguments for a conversion function, as in
14919 [temp.deduct.conv].
14921 DEDUCE_EXACT:
14922 We are deducing arguments when doing an explicit instantiation
14923 as in [temp.explicit], when determining an explicit specialization
14924 as in [temp.expl.spec], or when taking the address of a function
14925 template, as in [temp.deduct.funcaddr]. */
14927 tree
14928 fn_type_unification (tree fn,
14929 tree explicit_targs,
14930 tree targs,
14931 const tree *args,
14932 unsigned int nargs,
14933 tree return_type,
14934 unification_kind_t strict,
14935 int flags,
14936 bool explain_p)
14938 tree parms;
14939 tree fntype;
14940 tree decl = NULL_TREE;
14941 tsubst_flags_t complain = (explain_p ? tf_warning_or_error : tf_none);
14942 bool ok;
14943 static int deduction_depth;
14944 struct pending_template *old_last_pend = last_pending_template;
14945 struct tinst_level *old_error_tinst = last_error_tinst_level;
14946 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
14947 tree tinst;
14948 tree r = error_mark_node;
14950 /* In C++0x, it's possible to have a function template whose type depends
14951 on itself recursively. This is most obvious with decltype, but can also
14952 occur with enumeration scope (c++/48969). So we need to catch infinite
14953 recursion and reject the substitution at deduction time; this function
14954 will return error_mark_node for any repeated substitution.
14956 This also catches excessive recursion such as when f<N> depends on
14957 f<N-1> across all integers, and returns error_mark_node for all the
14958 substitutions back up to the initial one.
14960 This is, of course, not reentrant. */
14961 if (excessive_deduction_depth)
14962 return error_mark_node;
14963 tinst = build_tree_list (fn, NULL_TREE);
14964 ++deduction_depth;
14965 push_deferring_access_checks (dk_deferred);
14967 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
14969 fntype = TREE_TYPE (fn);
14970 if (explicit_targs)
14972 /* [temp.deduct]
14974 The specified template arguments must match the template
14975 parameters in kind (i.e., type, nontype, template), and there
14976 must not be more arguments than there are parameters;
14977 otherwise type deduction fails.
14979 Nontype arguments must match the types of the corresponding
14980 nontype template parameters, or must be convertible to the
14981 types of the corresponding nontype parameters as specified in
14982 _temp.arg.nontype_, otherwise type deduction fails.
14984 All references in the function type of the function template
14985 to the corresponding template parameters are replaced by the
14986 specified template argument values. If a substitution in a
14987 template parameter or in the function type of the function
14988 template results in an invalid type, type deduction fails. */
14989 int i, len = TREE_VEC_LENGTH (tparms);
14990 location_t loc = input_location;
14991 bool incomplete = false;
14993 /* Adjust any explicit template arguments before entering the
14994 substitution context. */
14995 explicit_targs
14996 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
14997 complain,
14998 /*require_all_args=*/false,
14999 /*use_default_args=*/false));
15000 if (explicit_targs == error_mark_node)
15001 goto fail;
15003 /* Substitute the explicit args into the function type. This is
15004 necessary so that, for instance, explicitly declared function
15005 arguments can match null pointed constants. If we were given
15006 an incomplete set of explicit args, we must not do semantic
15007 processing during substitution as we could create partial
15008 instantiations. */
15009 for (i = 0; i < len; i++)
15011 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15012 bool parameter_pack = false;
15013 tree targ = TREE_VEC_ELT (explicit_targs, i);
15015 /* Dig out the actual parm. */
15016 if (TREE_CODE (parm) == TYPE_DECL
15017 || TREE_CODE (parm) == TEMPLATE_DECL)
15019 parm = TREE_TYPE (parm);
15020 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
15022 else if (TREE_CODE (parm) == PARM_DECL)
15024 parm = DECL_INITIAL (parm);
15025 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
15028 if (!parameter_pack && targ == NULL_TREE)
15029 /* No explicit argument for this template parameter. */
15030 incomplete = true;
15032 if (parameter_pack && pack_deducible_p (parm, fn))
15034 /* Mark the argument pack as "incomplete". We could
15035 still deduce more arguments during unification.
15036 We remove this mark in type_unification_real. */
15037 if (targ)
15039 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
15040 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
15041 = ARGUMENT_PACK_ARGS (targ);
15044 /* We have some incomplete argument packs. */
15045 incomplete = true;
15049 TREE_VALUE (tinst) = explicit_targs;
15050 if (!push_tinst_level (tinst))
15052 excessive_deduction_depth = true;
15053 goto fail;
15055 processing_template_decl += incomplete;
15056 input_location = DECL_SOURCE_LOCATION (fn);
15057 fntype = tsubst (TREE_TYPE (fn), explicit_targs,
15058 complain | tf_partial, NULL_TREE);
15059 input_location = loc;
15060 processing_template_decl -= incomplete;
15061 pop_tinst_level ();
15063 if (fntype == error_mark_node)
15064 goto fail;
15066 /* Throw away these access checks; we'll see them again in
15067 instantiate_template and they might have the wrong
15068 access path at this point. */
15069 pop_deferring_access_checks ();
15070 push_deferring_access_checks (dk_deferred);
15072 /* Place the explicitly specified arguments in TARGS. */
15073 for (i = NUM_TMPL_ARGS (explicit_targs); i--;)
15074 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (explicit_targs, i);
15077 /* Never do unification on the 'this' parameter. */
15078 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
15080 if (return_type)
15082 tree *new_args;
15084 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
15085 new_args = XALLOCAVEC (tree, nargs + 1);
15086 new_args[0] = return_type;
15087 memcpy (new_args + 1, args, nargs * sizeof (tree));
15088 args = new_args;
15089 ++nargs;
15092 /* We allow incomplete unification without an error message here
15093 because the standard doesn't seem to explicitly prohibit it. Our
15094 callers must be ready to deal with unification failures in any
15095 event. */
15097 ok = !type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
15098 targs, parms, args, nargs, /*subr=*/0,
15099 strict, flags, explain_p);
15100 if (!ok)
15101 goto fail;
15103 /* Now that we have bindings for all of the template arguments,
15104 ensure that the arguments deduced for the template template
15105 parameters have compatible template parameter lists. We cannot
15106 check this property before we have deduced all template
15107 arguments, because the template parameter types of a template
15108 template parameter might depend on prior template parameters
15109 deduced after the template template parameter. The following
15110 ill-formed example illustrates this issue:
15112 template<typename T, template<T> class C> void f(C<5>, T);
15114 template<int N> struct X {};
15116 void g() {
15117 f(X<5>(), 5l); // error: template argument deduction fails
15120 The template parameter list of 'C' depends on the template type
15121 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15122 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15123 time that we deduce 'C'. */
15124 if (!template_template_parm_bindings_ok_p
15125 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
15127 unify_inconsistent_template_template_parameters (explain_p);
15128 goto fail;
15131 /* All is well so far. Now, check:
15133 [temp.deduct]
15135 When all template arguments have been deduced, all uses of
15136 template parameters in nondeduced contexts are replaced with
15137 the corresponding deduced argument values. If the
15138 substitution results in an invalid type, as described above,
15139 type deduction fails. */
15140 TREE_VALUE (tinst) = targs;
15141 if (!push_tinst_level (tinst))
15143 excessive_deduction_depth = true;
15144 goto fail;
15146 decl = instantiate_template (fn, targs, complain);
15147 pop_tinst_level ();
15149 if (decl == error_mark_node)
15150 goto fail;
15152 /* Now perform any access checks encountered during deduction, such as
15153 for default template arguments. */
15154 push_access_scope (decl);
15155 ok = perform_deferred_access_checks (complain);
15156 pop_access_scope (decl);
15157 if (!ok)
15158 goto fail;
15160 /* If we're looking for an exact match, check that what we got
15161 is indeed an exact match. It might not be if some template
15162 parameters are used in non-deduced contexts. */
15163 if (strict == DEDUCE_EXACT)
15165 tree substed = TREE_TYPE (decl);
15166 unsigned int i;
15168 tree sarg
15169 = skip_artificial_parms_for (decl, TYPE_ARG_TYPES (substed));
15170 if (return_type)
15171 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
15172 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
15173 if (!same_type_p (args[i], TREE_VALUE (sarg)))
15175 unify_type_mismatch (explain_p, args[i],
15176 TREE_VALUE (sarg));
15177 goto fail;
15181 r = decl;
15183 fail:
15184 pop_deferring_access_checks ();
15185 --deduction_depth;
15186 if (excessive_deduction_depth)
15188 if (deduction_depth == 0)
15189 /* Reset once we're all the way out. */
15190 excessive_deduction_depth = false;
15193 /* We can't free this if a pending_template entry or last_error_tinst_level
15194 is pointing at it. */
15195 if (last_pending_template == old_last_pend
15196 && last_error_tinst_level == old_error_tinst)
15197 ggc_free (tinst);
15199 return r;
15202 /* Adjust types before performing type deduction, as described in
15203 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15204 sections are symmetric. PARM is the type of a function parameter
15205 or the return type of the conversion function. ARG is the type of
15206 the argument passed to the call, or the type of the value
15207 initialized with the result of the conversion function.
15208 ARG_EXPR is the original argument expression, which may be null. */
15210 static int
15211 maybe_adjust_types_for_deduction (unification_kind_t strict,
15212 tree* parm,
15213 tree* arg,
15214 tree arg_expr)
15216 int result = 0;
15218 switch (strict)
15220 case DEDUCE_CALL:
15221 break;
15223 case DEDUCE_CONV:
15225 /* Swap PARM and ARG throughout the remainder of this
15226 function; the handling is precisely symmetric since PARM
15227 will initialize ARG rather than vice versa. */
15228 tree* temp = parm;
15229 parm = arg;
15230 arg = temp;
15231 break;
15234 case DEDUCE_EXACT:
15235 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15236 too, but here handle it by stripping the reference from PARM
15237 rather than by adding it to ARG. */
15238 if (TREE_CODE (*parm) == REFERENCE_TYPE
15239 && TYPE_REF_IS_RVALUE (*parm)
15240 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15241 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15242 && TREE_CODE (*arg) == REFERENCE_TYPE
15243 && !TYPE_REF_IS_RVALUE (*arg))
15244 *parm = TREE_TYPE (*parm);
15245 /* Nothing else to do in this case. */
15246 return 0;
15248 default:
15249 gcc_unreachable ();
15252 if (TREE_CODE (*parm) != REFERENCE_TYPE)
15254 /* [temp.deduct.call]
15256 If P is not a reference type:
15258 --If A is an array type, the pointer type produced by the
15259 array-to-pointer standard conversion (_conv.array_) is
15260 used in place of A for type deduction; otherwise,
15262 --If A is a function type, the pointer type produced by
15263 the function-to-pointer standard conversion
15264 (_conv.func_) is used in place of A for type deduction;
15265 otherwise,
15267 --If A is a cv-qualified type, the top level
15268 cv-qualifiers of A's type are ignored for type
15269 deduction. */
15270 if (TREE_CODE (*arg) == ARRAY_TYPE)
15271 *arg = build_pointer_type (TREE_TYPE (*arg));
15272 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
15273 *arg = build_pointer_type (*arg);
15274 else
15275 *arg = TYPE_MAIN_VARIANT (*arg);
15278 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15279 of the form T&&, where T is a template parameter, and the argument
15280 is an lvalue, T is deduced as A& */
15281 if (TREE_CODE (*parm) == REFERENCE_TYPE
15282 && TYPE_REF_IS_RVALUE (*parm)
15283 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15284 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15285 && (arg_expr ? real_lvalue_p (arg_expr)
15286 /* try_one_overload doesn't provide an arg_expr, but
15287 functions are always lvalues. */
15288 : TREE_CODE (*arg) == FUNCTION_TYPE))
15289 *arg = build_reference_type (*arg);
15291 /* [temp.deduct.call]
15293 If P is a cv-qualified type, the top level cv-qualifiers
15294 of P's type are ignored for type deduction. If P is a
15295 reference type, the type referred to by P is used for
15296 type deduction. */
15297 *parm = TYPE_MAIN_VARIANT (*parm);
15298 if (TREE_CODE (*parm) == REFERENCE_TYPE)
15300 *parm = TREE_TYPE (*parm);
15301 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15304 /* DR 322. For conversion deduction, remove a reference type on parm
15305 too (which has been swapped into ARG). */
15306 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
15307 *arg = TREE_TYPE (*arg);
15309 return result;
15312 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15313 template which does contain any deducible template parameters; check if
15314 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15315 unify_one_argument. */
15317 static int
15318 check_non_deducible_conversion (tree parm, tree arg, int strict,
15319 int flags, bool explain_p)
15321 tree type;
15323 if (!TYPE_P (arg))
15324 type = TREE_TYPE (arg);
15325 else
15326 type = arg;
15328 if (same_type_p (parm, type))
15329 return unify_success (explain_p);
15331 if (strict == DEDUCE_CONV)
15333 if (can_convert_arg (type, parm, NULL_TREE, flags,
15334 explain_p ? tf_warning_or_error : tf_none))
15335 return unify_success (explain_p);
15337 else if (strict != DEDUCE_EXACT)
15339 if (can_convert_arg (parm, type,
15340 TYPE_P (arg) ? NULL_TREE : arg,
15341 flags, explain_p ? tf_warning_or_error : tf_none))
15342 return unify_success (explain_p);
15345 if (strict == DEDUCE_EXACT)
15346 return unify_type_mismatch (explain_p, parm, arg);
15347 else
15348 return unify_arg_conversion (explain_p, parm, type, arg);
15351 /* Subroutine of type_unification_real and unify_pack_expansion to
15352 handle unification of a single P/A pair. Parameters are as
15353 for those functions. */
15355 static int
15356 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
15357 int subr, unification_kind_t strict, int flags,
15358 bool explain_p)
15360 tree arg_expr = NULL_TREE;
15361 int arg_strict;
15363 if (arg == error_mark_node || parm == error_mark_node)
15364 return unify_invalid (explain_p);
15365 if (arg == unknown_type_node)
15366 /* We can't deduce anything from this, but we might get all the
15367 template args from other function args. */
15368 return unify_success (explain_p);
15370 /* FIXME uses_deducible_template_parms */
15371 if (TYPE_P (parm) && !uses_template_parms (parm))
15372 return check_non_deducible_conversion (parm, arg, strict, flags,
15373 explain_p);
15375 switch (strict)
15377 case DEDUCE_CALL:
15378 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15379 | UNIFY_ALLOW_MORE_CV_QUAL
15380 | UNIFY_ALLOW_DERIVED);
15381 break;
15383 case DEDUCE_CONV:
15384 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
15385 break;
15387 case DEDUCE_EXACT:
15388 arg_strict = UNIFY_ALLOW_NONE;
15389 break;
15391 default:
15392 gcc_unreachable ();
15395 /* We only do these transformations if this is the top-level
15396 parameter_type_list in a call or declaration matching; in other
15397 situations (nested function declarators, template argument lists) we
15398 won't be comparing a type to an expression, and we don't do any type
15399 adjustments. */
15400 if (!subr)
15402 if (!TYPE_P (arg))
15404 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
15405 if (type_unknown_p (arg))
15407 /* [temp.deduct.type] A template-argument can be
15408 deduced from a pointer to function or pointer
15409 to member function argument if the set of
15410 overloaded functions does not contain function
15411 templates and at most one of a set of
15412 overloaded functions provides a unique
15413 match. */
15415 if (resolve_overloaded_unification
15416 (tparms, targs, parm, arg, strict,
15417 arg_strict, explain_p))
15418 return unify_success (explain_p);
15419 return unify_overload_resolution_failure (explain_p, arg);
15422 arg_expr = arg;
15423 arg = unlowered_expr_type (arg);
15424 if (arg == error_mark_node)
15425 return unify_invalid (explain_p);
15428 arg_strict |=
15429 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
15431 else
15432 gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
15433 == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL));
15435 /* For deduction from an init-list we need the actual list. */
15436 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15437 arg = arg_expr;
15438 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
15441 /* Most parms like fn_type_unification.
15443 If SUBR is 1, we're being called recursively (to unify the
15444 arguments of a function or method parameter of a function
15445 template). */
15447 static int
15448 type_unification_real (tree tparms,
15449 tree targs,
15450 tree xparms,
15451 const tree *xargs,
15452 unsigned int xnargs,
15453 int subr,
15454 unification_kind_t strict,
15455 int flags,
15456 bool explain_p)
15458 tree parm, arg;
15459 int i;
15460 int ntparms = TREE_VEC_LENGTH (tparms);
15461 int saw_undeduced = 0;
15462 tree parms;
15463 const tree *args;
15464 unsigned int nargs;
15465 unsigned int ia;
15467 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
15468 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
15469 gcc_assert (ntparms > 0);
15471 /* Reset the number of non-defaulted template arguments contained
15472 in TARGS. */
15473 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
15475 again:
15476 parms = xparms;
15477 args = xargs;
15478 nargs = xnargs;
15480 ia = 0;
15481 while (parms && parms != void_list_node
15482 && ia < nargs)
15484 parm = TREE_VALUE (parms);
15486 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
15487 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
15488 /* For a function parameter pack that occurs at the end of the
15489 parameter-declaration-list, the type A of each remaining
15490 argument of the call is compared with the type P of the
15491 declarator-id of the function parameter pack. */
15492 break;
15494 parms = TREE_CHAIN (parms);
15496 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
15497 /* For a function parameter pack that does not occur at the
15498 end of the parameter-declaration-list, the type of the
15499 parameter pack is a non-deduced context. */
15500 continue;
15502 arg = args[ia];
15503 ++ia;
15505 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15506 flags, explain_p))
15507 return 1;
15510 if (parms
15511 && parms != void_list_node
15512 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
15514 /* Unify the remaining arguments with the pack expansion type. */
15515 tree argvec;
15516 tree parmvec = make_tree_vec (1);
15518 /* Allocate a TREE_VEC and copy in all of the arguments */
15519 argvec = make_tree_vec (nargs - ia);
15520 for (i = 0; ia < nargs; ++ia, ++i)
15521 TREE_VEC_ELT (argvec, i) = args[ia];
15523 /* Copy the parameter into parmvec. */
15524 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
15525 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
15526 /*subr=*/subr, explain_p))
15527 return 1;
15529 /* Advance to the end of the list of parameters. */
15530 parms = TREE_CHAIN (parms);
15533 /* Fail if we've reached the end of the parm list, and more args
15534 are present, and the parm list isn't variadic. */
15535 if (ia < nargs && parms == void_list_node)
15536 return unify_too_many_arguments (explain_p, nargs, ia);
15537 /* Fail if parms are left and they don't have default values. */
15538 if (parms && parms != void_list_node
15539 && TREE_PURPOSE (parms) == NULL_TREE)
15541 unsigned int count = nargs;
15542 tree p = parms;
15543 while (p && p != void_list_node)
15545 count++;
15546 p = TREE_CHAIN (p);
15548 return unify_too_few_arguments (explain_p, ia, count);
15551 if (!subr)
15553 tsubst_flags_t complain = (explain_p
15554 ? tf_warning_or_error
15555 : tf_none);
15557 for (i = 0; i < ntparms; i++)
15559 tree targ = TREE_VEC_ELT (targs, i);
15560 tree tparm = TREE_VEC_ELT (tparms, i);
15562 /* Clear the "incomplete" flags on all argument packs now so that
15563 substituting them into later default arguments works. */
15564 if (targ && ARGUMENT_PACK_P (targ))
15566 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
15567 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
15570 if (targ || tparm == error_mark_node)
15571 continue;
15572 tparm = TREE_VALUE (tparm);
15574 /* If this is an undeduced nontype parameter that depends on
15575 a type parameter, try another pass; its type may have been
15576 deduced from a later argument than the one from which
15577 this parameter can be deduced. */
15578 if (TREE_CODE (tparm) == PARM_DECL
15579 && uses_template_parms (TREE_TYPE (tparm))
15580 && !saw_undeduced++)
15581 goto again;
15583 /* Core issue #226 (C++0x) [temp.deduct]:
15585 If a template argument has not been deduced, its
15586 default template argument, if any, is used.
15588 When we are in C++98 mode, TREE_PURPOSE will either
15589 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15590 to explicitly check cxx_dialect here. */
15591 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
15593 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15594 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
15595 location_t save_loc = input_location;
15596 if (DECL_P (parm))
15597 input_location = DECL_SOURCE_LOCATION (parm);
15598 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
15599 arg = convert_template_argument (parm, arg, targs, complain,
15600 i, NULL_TREE);
15601 input_location = save_loc;
15602 if (arg == error_mark_node)
15603 return 1;
15604 else
15606 TREE_VEC_ELT (targs, i) = arg;
15607 /* The position of the first default template argument,
15608 is also the number of non-defaulted arguments in TARGS.
15609 Record that. */
15610 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15611 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
15612 continue;
15616 /* If the type parameter is a parameter pack, then it will
15617 be deduced to an empty parameter pack. */
15618 if (template_parameter_pack_p (tparm))
15620 tree arg;
15622 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
15624 arg = make_node (NONTYPE_ARGUMENT_PACK);
15625 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
15626 TREE_CONSTANT (arg) = 1;
15628 else
15629 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
15631 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
15633 TREE_VEC_ELT (targs, i) = arg;
15634 continue;
15637 return unify_parameter_deduction_failure (explain_p, tparm);
15640 #ifdef ENABLE_CHECKING
15641 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15642 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
15643 #endif
15645 return unify_success (explain_p);
15648 /* Subroutine of type_unification_real. Args are like the variables
15649 at the call site. ARG is an overloaded function (or template-id);
15650 we try deducing template args from each of the overloads, and if
15651 only one succeeds, we go with that. Modifies TARGS and returns
15652 true on success. */
15654 static bool
15655 resolve_overloaded_unification (tree tparms,
15656 tree targs,
15657 tree parm,
15658 tree arg,
15659 unification_kind_t strict,
15660 int sub_strict,
15661 bool explain_p)
15663 tree tempargs = copy_node (targs);
15664 int good = 0;
15665 tree goodfn = NULL_TREE;
15666 bool addr_p;
15668 if (TREE_CODE (arg) == ADDR_EXPR)
15670 arg = TREE_OPERAND (arg, 0);
15671 addr_p = true;
15673 else
15674 addr_p = false;
15676 if (TREE_CODE (arg) == COMPONENT_REF)
15677 /* Handle `&x' where `x' is some static or non-static member
15678 function name. */
15679 arg = TREE_OPERAND (arg, 1);
15681 if (TREE_CODE (arg) == OFFSET_REF)
15682 arg = TREE_OPERAND (arg, 1);
15684 /* Strip baselink information. */
15685 if (BASELINK_P (arg))
15686 arg = BASELINK_FUNCTIONS (arg);
15688 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
15690 /* If we got some explicit template args, we need to plug them into
15691 the affected templates before we try to unify, in case the
15692 explicit args will completely resolve the templates in question. */
15694 int ok = 0;
15695 tree expl_subargs = TREE_OPERAND (arg, 1);
15696 arg = TREE_OPERAND (arg, 0);
15698 for (; arg; arg = OVL_NEXT (arg))
15700 tree fn = OVL_CURRENT (arg);
15701 tree subargs, elem;
15703 if (TREE_CODE (fn) != TEMPLATE_DECL)
15704 continue;
15706 subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
15707 expl_subargs, NULL_TREE, tf_none,
15708 /*require_all_args=*/true,
15709 /*use_default_args=*/true);
15710 if (subargs != error_mark_node
15711 && !any_dependent_template_arguments_p (subargs))
15713 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
15714 if (try_one_overload (tparms, targs, tempargs, parm,
15715 elem, strict, sub_strict, addr_p, explain_p)
15716 && (!goodfn || !same_type_p (goodfn, elem)))
15718 goodfn = elem;
15719 ++good;
15722 else if (subargs)
15723 ++ok;
15725 /* If no templates (or more than one) are fully resolved by the
15726 explicit arguments, this template-id is a non-deduced context; it
15727 could still be OK if we deduce all template arguments for the
15728 enclosing call through other arguments. */
15729 if (good != 1)
15730 good = ok;
15732 else if (TREE_CODE (arg) != OVERLOAD
15733 && TREE_CODE (arg) != FUNCTION_DECL)
15734 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15735 -- but the deduction does not succeed because the expression is
15736 not just the function on its own. */
15737 return false;
15738 else
15739 for (; arg; arg = OVL_NEXT (arg))
15740 if (try_one_overload (tparms, targs, tempargs, parm,
15741 TREE_TYPE (OVL_CURRENT (arg)),
15742 strict, sub_strict, addr_p, explain_p)
15743 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
15745 goodfn = OVL_CURRENT (arg);
15746 ++good;
15749 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15750 to function or pointer to member function argument if the set of
15751 overloaded functions does not contain function templates and at most
15752 one of a set of overloaded functions provides a unique match.
15754 So if we found multiple possibilities, we return success but don't
15755 deduce anything. */
15757 if (good == 1)
15759 int i = TREE_VEC_LENGTH (targs);
15760 for (; i--; )
15761 if (TREE_VEC_ELT (tempargs, i))
15762 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
15764 if (good)
15765 return true;
15767 return false;
15770 /* Core DR 115: In contexts where deduction is done and fails, or in
15771 contexts where deduction is not done, if a template argument list is
15772 specified and it, along with any default template arguments, identifies
15773 a single function template specialization, then the template-id is an
15774 lvalue for the function template specialization. */
15776 tree
15777 resolve_nondeduced_context (tree orig_expr)
15779 tree expr, offset, baselink;
15780 bool addr;
15782 if (!type_unknown_p (orig_expr))
15783 return orig_expr;
15785 expr = orig_expr;
15786 addr = false;
15787 offset = NULL_TREE;
15788 baselink = NULL_TREE;
15790 if (TREE_CODE (expr) == ADDR_EXPR)
15792 expr = TREE_OPERAND (expr, 0);
15793 addr = true;
15795 if (TREE_CODE (expr) == OFFSET_REF)
15797 offset = expr;
15798 expr = TREE_OPERAND (expr, 1);
15800 if (BASELINK_P (expr))
15802 baselink = expr;
15803 expr = BASELINK_FUNCTIONS (expr);
15806 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
15808 int good = 0;
15809 tree goodfn = NULL_TREE;
15811 /* If we got some explicit template args, we need to plug them into
15812 the affected templates before we try to unify, in case the
15813 explicit args will completely resolve the templates in question. */
15815 tree expl_subargs = TREE_OPERAND (expr, 1);
15816 tree arg = TREE_OPERAND (expr, 0);
15817 tree badfn = NULL_TREE;
15818 tree badargs = NULL_TREE;
15820 for (; arg; arg = OVL_NEXT (arg))
15822 tree fn = OVL_CURRENT (arg);
15823 tree subargs, elem;
15825 if (TREE_CODE (fn) != TEMPLATE_DECL)
15826 continue;
15828 subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
15829 expl_subargs, NULL_TREE, tf_none,
15830 /*require_all_args=*/true,
15831 /*use_default_args=*/true);
15832 if (subargs != error_mark_node
15833 && !any_dependent_template_arguments_p (subargs))
15835 elem = instantiate_template (fn, subargs, tf_none);
15836 if (elem == error_mark_node)
15838 badfn = fn;
15839 badargs = subargs;
15841 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
15843 goodfn = elem;
15844 ++good;
15848 if (good == 1)
15850 mark_used (goodfn);
15851 expr = goodfn;
15852 if (baselink)
15853 expr = build_baselink (BASELINK_BINFO (baselink),
15854 BASELINK_ACCESS_BINFO (baselink),
15855 expr, BASELINK_OPTYPE (baselink));
15856 if (offset)
15858 tree base
15859 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
15860 expr = build_offset_ref (base, expr, addr);
15862 if (addr)
15863 expr = cp_build_addr_expr (expr, tf_warning_or_error);
15864 return expr;
15866 else if (good == 0 && badargs)
15867 /* There were no good options and at least one bad one, so let the
15868 user know what the problem is. */
15869 instantiate_template (badfn, badargs, tf_warning_or_error);
15871 return orig_expr;
15874 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15875 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15876 different overloads deduce different arguments for a given parm.
15877 ADDR_P is true if the expression for which deduction is being
15878 performed was of the form "& fn" rather than simply "fn".
15880 Returns 1 on success. */
15882 static int
15883 try_one_overload (tree tparms,
15884 tree orig_targs,
15885 tree targs,
15886 tree parm,
15887 tree arg,
15888 unification_kind_t strict,
15889 int sub_strict,
15890 bool addr_p,
15891 bool explain_p)
15893 int nargs;
15894 tree tempargs;
15895 int i;
15897 if (arg == error_mark_node)
15898 return 0;
15900 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15901 to function or pointer to member function argument if the set of
15902 overloaded functions does not contain function templates and at most
15903 one of a set of overloaded functions provides a unique match.
15905 So if this is a template, just return success. */
15907 if (uses_template_parms (arg))
15908 return 1;
15910 if (TREE_CODE (arg) == METHOD_TYPE)
15911 arg = build_ptrmemfunc_type (build_pointer_type (arg));
15912 else if (addr_p)
15913 arg = build_pointer_type (arg);
15915 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
15917 /* We don't copy orig_targs for this because if we have already deduced
15918 some template args from previous args, unify would complain when we
15919 try to deduce a template parameter for the same argument, even though
15920 there isn't really a conflict. */
15921 nargs = TREE_VEC_LENGTH (targs);
15922 tempargs = make_tree_vec (nargs);
15924 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
15925 return 0;
15927 /* First make sure we didn't deduce anything that conflicts with
15928 explicitly specified args. */
15929 for (i = nargs; i--; )
15931 tree elt = TREE_VEC_ELT (tempargs, i);
15932 tree oldelt = TREE_VEC_ELT (orig_targs, i);
15934 if (!elt)
15935 /*NOP*/;
15936 else if (uses_template_parms (elt))
15937 /* Since we're unifying against ourselves, we will fill in
15938 template args used in the function parm list with our own
15939 template parms. Discard them. */
15940 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
15941 else if (oldelt && !template_args_equal (oldelt, elt))
15942 return 0;
15945 for (i = nargs; i--; )
15947 tree elt = TREE_VEC_ELT (tempargs, i);
15949 if (elt)
15950 TREE_VEC_ELT (targs, i) = elt;
15953 return 1;
15956 /* PARM is a template class (perhaps with unbound template
15957 parameters). ARG is a fully instantiated type. If ARG can be
15958 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15959 TARGS are as for unify. */
15961 static tree
15962 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
15963 bool explain_p)
15965 tree copy_of_targs;
15967 if (!CLASSTYPE_TEMPLATE_INFO (arg)
15968 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
15969 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
15970 return NULL_TREE;
15972 /* We need to make a new template argument vector for the call to
15973 unify. If we used TARGS, we'd clutter it up with the result of
15974 the attempted unification, even if this class didn't work out.
15975 We also don't want to commit ourselves to all the unifications
15976 we've already done, since unification is supposed to be done on
15977 an argument-by-argument basis. In other words, consider the
15978 following pathological case:
15980 template <int I, int J, int K>
15981 struct S {};
15983 template <int I, int J>
15984 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15986 template <int I, int J, int K>
15987 void f(S<I, J, K>, S<I, I, I>);
15989 void g() {
15990 S<0, 0, 0> s0;
15991 S<0, 1, 2> s2;
15993 f(s0, s2);
15996 Now, by the time we consider the unification involving `s2', we
15997 already know that we must have `f<0, 0, 0>'. But, even though
15998 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15999 because there are two ways to unify base classes of S<0, 1, 2>
16000 with S<I, I, I>. If we kept the already deduced knowledge, we
16001 would reject the possibility I=1. */
16002 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
16004 /* If unification failed, we're done. */
16005 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
16006 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
16007 return NULL_TREE;
16009 return arg;
16012 /* Given a template type PARM and a class type ARG, find the unique
16013 base type in ARG that is an instance of PARM. We do not examine
16014 ARG itself; only its base-classes. If there is not exactly one
16015 appropriate base class, return NULL_TREE. PARM may be the type of
16016 a partial specialization, as well as a plain template type. Used
16017 by unify. */
16019 static enum template_base_result
16020 get_template_base (tree tparms, tree targs, tree parm, tree arg,
16021 bool explain_p, tree *result)
16023 tree rval = NULL_TREE;
16024 tree binfo;
16026 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
16028 binfo = TYPE_BINFO (complete_type (arg));
16029 if (!binfo)
16031 /* The type could not be completed. */
16032 *result = NULL_TREE;
16033 return tbr_incomplete_type;
16036 /* Walk in inheritance graph order. The search order is not
16037 important, and this avoids multiple walks of virtual bases. */
16038 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
16040 tree r = try_class_unification (tparms, targs, parm,
16041 BINFO_TYPE (binfo), explain_p);
16043 if (r)
16045 /* If there is more than one satisfactory baseclass, then:
16047 [temp.deduct.call]
16049 If they yield more than one possible deduced A, the type
16050 deduction fails.
16052 applies. */
16053 if (rval && !same_type_p (r, rval))
16055 *result = NULL_TREE;
16056 return tbr_ambiguous_baseclass;
16059 rval = r;
16063 *result = rval;
16064 return tbr_success;
16067 /* Returns the level of DECL, which declares a template parameter. */
16069 static int
16070 template_decl_level (tree decl)
16072 switch (TREE_CODE (decl))
16074 case TYPE_DECL:
16075 case TEMPLATE_DECL:
16076 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
16078 case PARM_DECL:
16079 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
16081 default:
16082 gcc_unreachable ();
16084 return 0;
16087 /* Decide whether ARG can be unified with PARM, considering only the
16088 cv-qualifiers of each type, given STRICT as documented for unify.
16089 Returns nonzero iff the unification is OK on that basis. */
16091 static int
16092 check_cv_quals_for_unify (int strict, tree arg, tree parm)
16094 int arg_quals = cp_type_quals (arg);
16095 int parm_quals = cp_type_quals (parm);
16097 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16098 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
16100 /* Although a CVR qualifier is ignored when being applied to a
16101 substituted template parameter ([8.3.2]/1 for example), that
16102 does not allow us to unify "const T" with "int&" because both
16103 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
16104 It is ok when we're allowing additional CV qualifiers
16105 at the outer level [14.8.2.1]/3,1st bullet. */
16106 if ((TREE_CODE (arg) == REFERENCE_TYPE
16107 || TREE_CODE (arg) == FUNCTION_TYPE
16108 || TREE_CODE (arg) == METHOD_TYPE)
16109 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
16110 return 0;
16112 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
16113 && (parm_quals & TYPE_QUAL_RESTRICT))
16114 return 0;
16117 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
16118 && (arg_quals & parm_quals) != parm_quals)
16119 return 0;
16121 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
16122 && (parm_quals & arg_quals) != arg_quals)
16123 return 0;
16125 return 1;
16128 /* Determines the LEVEL and INDEX for the template parameter PARM. */
16129 void
16130 template_parm_level_and_index (tree parm, int* level, int* index)
16132 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16133 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16134 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16136 *index = TEMPLATE_TYPE_IDX (parm);
16137 *level = TEMPLATE_TYPE_LEVEL (parm);
16139 else
16141 *index = TEMPLATE_PARM_IDX (parm);
16142 *level = TEMPLATE_PARM_LEVEL (parm);
16146 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
16147 do { \
16148 if (unify (TP, TA, P, A, S, EP)) \
16149 return 1; \
16150 } while (0);
16152 /* Unifies the remaining arguments in PACKED_ARGS with the pack
16153 expansion at the end of PACKED_PARMS. Returns 0 if the type
16154 deduction succeeds, 1 otherwise. STRICT is the same as in
16155 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
16156 call argument list. We'll need to adjust the arguments to make them
16157 types. SUBR tells us if this is from a recursive call to
16158 type_unification_real, or for comparing two template argument
16159 lists. */
16161 static int
16162 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
16163 tree packed_args, unification_kind_t strict,
16164 bool subr, bool explain_p)
16166 tree parm
16167 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
16168 tree pattern = PACK_EXPANSION_PATTERN (parm);
16169 tree pack, packs = NULL_TREE;
16170 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
16171 int len = TREE_VEC_LENGTH (packed_args);
16173 /* Determine the parameter packs we will be deducing from the
16174 pattern, and record their current deductions. */
16175 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
16176 pack; pack = TREE_CHAIN (pack))
16178 tree parm_pack = TREE_VALUE (pack);
16179 int idx, level;
16181 /* Determine the index and level of this parameter pack. */
16182 template_parm_level_and_index (parm_pack, &level, &idx);
16184 /* Keep track of the parameter packs and their corresponding
16185 argument packs. */
16186 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
16187 TREE_TYPE (packs) = make_tree_vec (len - start);
16190 /* Loop through all of the arguments that have not yet been
16191 unified and unify each with the pattern. */
16192 for (i = start; i < len; i++)
16194 tree parm;
16195 bool any_explicit = false;
16196 tree arg = TREE_VEC_ELT (packed_args, i);
16198 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
16199 or the element of its argument pack at the current index if
16200 this argument was explicitly specified. */
16201 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16203 int idx, level;
16204 tree arg, pargs;
16205 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16207 arg = NULL_TREE;
16208 if (TREE_VALUE (pack)
16209 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
16210 && (i < TREE_VEC_LENGTH (pargs)))
16212 any_explicit = true;
16213 arg = TREE_VEC_ELT (pargs, i);
16215 TMPL_ARG (targs, level, idx) = arg;
16218 /* If we had explicit template arguments, substitute them into the
16219 pattern before deduction. */
16220 if (any_explicit)
16222 /* Some arguments might still be unspecified or dependent. */
16223 bool dependent;
16224 ++processing_template_decl;
16225 dependent = any_dependent_template_arguments_p (targs);
16226 if (!dependent)
16227 --processing_template_decl;
16228 parm = tsubst (pattern, targs,
16229 explain_p ? tf_warning_or_error : tf_none,
16230 NULL_TREE);
16231 if (dependent)
16232 --processing_template_decl;
16233 if (parm == error_mark_node)
16234 return 1;
16236 else
16237 parm = pattern;
16239 /* Unify the pattern with the current argument. */
16240 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
16241 LOOKUP_IMPLICIT, explain_p))
16242 return 1;
16244 /* For each parameter pack, collect the deduced value. */
16245 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16247 int idx, level;
16248 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16250 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
16251 TMPL_ARG (targs, level, idx);
16255 /* Verify that the results of unification with the parameter packs
16256 produce results consistent with what we've seen before, and make
16257 the deduced argument packs available. */
16258 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16260 tree old_pack = TREE_VALUE (pack);
16261 tree new_args = TREE_TYPE (pack);
16262 int i, len = TREE_VEC_LENGTH (new_args);
16263 int idx, level;
16264 bool nondeduced_p = false;
16266 /* By default keep the original deduced argument pack.
16267 If necessary, more specific code is going to update the
16268 resulting deduced argument later down in this function. */
16269 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16270 TMPL_ARG (targs, level, idx) = old_pack;
16272 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16273 actually deduce anything. */
16274 for (i = 0; i < len && !nondeduced_p; ++i)
16275 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
16276 nondeduced_p = true;
16277 if (nondeduced_p)
16278 continue;
16280 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
16282 /* If we had fewer function args than explicit template args,
16283 just use the explicits. */
16284 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16285 int explicit_len = TREE_VEC_LENGTH (explicit_args);
16286 if (len < explicit_len)
16287 new_args = explicit_args;
16290 if (!old_pack)
16292 tree result;
16293 /* Build the deduced *_ARGUMENT_PACK. */
16294 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
16296 result = make_node (NONTYPE_ARGUMENT_PACK);
16297 TREE_TYPE (result) =
16298 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
16299 TREE_CONSTANT (result) = 1;
16301 else
16302 result = cxx_make_type (TYPE_ARGUMENT_PACK);
16304 SET_ARGUMENT_PACK_ARGS (result, new_args);
16306 /* Note the deduced argument packs for this parameter
16307 pack. */
16308 TMPL_ARG (targs, level, idx) = result;
16310 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
16311 && (ARGUMENT_PACK_ARGS (old_pack)
16312 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
16314 /* We only had the explicitly-provided arguments before, but
16315 now we have a complete set of arguments. */
16316 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16318 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
16319 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
16320 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
16322 else
16324 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
16325 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
16327 if (!comp_template_args_with_info (old_args, new_args,
16328 &bad_old_arg, &bad_new_arg))
16329 /* Inconsistent unification of this parameter pack. */
16330 return unify_parameter_pack_inconsistent (explain_p,
16331 bad_old_arg,
16332 bad_new_arg);
16336 return unify_success (explain_p);
16339 /* Deduce the value of template parameters. TPARMS is the (innermost)
16340 set of template parameters to a template. TARGS is the bindings
16341 for those template parameters, as determined thus far; TARGS may
16342 include template arguments for outer levels of template parameters
16343 as well. PARM is a parameter to a template function, or a
16344 subcomponent of that parameter; ARG is the corresponding argument.
16345 This function attempts to match PARM with ARG in a manner
16346 consistent with the existing assignments in TARGS. If more values
16347 are deduced, then TARGS is updated.
16349 Returns 0 if the type deduction succeeds, 1 otherwise. The
16350 parameter STRICT is a bitwise or of the following flags:
16352 UNIFY_ALLOW_NONE:
16353 Require an exact match between PARM and ARG.
16354 UNIFY_ALLOW_MORE_CV_QUAL:
16355 Allow the deduced ARG to be more cv-qualified (by qualification
16356 conversion) than ARG.
16357 UNIFY_ALLOW_LESS_CV_QUAL:
16358 Allow the deduced ARG to be less cv-qualified than ARG.
16359 UNIFY_ALLOW_DERIVED:
16360 Allow the deduced ARG to be a template base class of ARG,
16361 or a pointer to a template base class of the type pointed to by
16362 ARG.
16363 UNIFY_ALLOW_INTEGER:
16364 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16365 case for more information.
16366 UNIFY_ALLOW_OUTER_LEVEL:
16367 This is the outermost level of a deduction. Used to determine validity
16368 of qualification conversions. A valid qualification conversion must
16369 have const qualified pointers leading up to the inner type which
16370 requires additional CV quals, except at the outer level, where const
16371 is not required [conv.qual]. It would be normal to set this flag in
16372 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16373 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16374 This is the outermost level of a deduction, and PARM can be more CV
16375 qualified at this point.
16376 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16377 This is the outermost level of a deduction, and PARM can be less CV
16378 qualified at this point. */
16380 static int
16381 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
16382 bool explain_p)
16384 int idx;
16385 tree targ;
16386 tree tparm;
16387 int strict_in = strict;
16389 /* I don't think this will do the right thing with respect to types.
16390 But the only case I've seen it in so far has been array bounds, where
16391 signedness is the only information lost, and I think that will be
16392 okay. */
16393 while (TREE_CODE (parm) == NOP_EXPR)
16394 parm = TREE_OPERAND (parm, 0);
16396 if (arg == error_mark_node)
16397 return unify_invalid (explain_p);
16398 if (arg == unknown_type_node
16399 || arg == init_list_type_node)
16400 /* We can't deduce anything from this, but we might get all the
16401 template args from other function args. */
16402 return unify_success (explain_p);
16404 /* If PARM uses template parameters, then we can't bail out here,
16405 even if ARG == PARM, since we won't record unifications for the
16406 template parameters. We might need them if we're trying to
16407 figure out which of two things is more specialized. */
16408 if (arg == parm && !uses_template_parms (parm))
16409 return unify_success (explain_p);
16411 /* Handle init lists early, so the rest of the function can assume
16412 we're dealing with a type. */
16413 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
16415 tree elt, elttype;
16416 unsigned i;
16417 tree orig_parm = parm;
16419 /* Replace T with std::initializer_list<T> for deduction. */
16420 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16421 && flag_deduce_init_list)
16422 parm = listify (parm);
16424 if (!is_std_init_list (parm))
16425 /* We can only deduce from an initializer list argument if the
16426 parameter is std::initializer_list; otherwise this is a
16427 non-deduced context. */
16428 return unify_success (explain_p);
16430 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
16432 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
16434 int elt_strict = strict;
16436 if (elt == error_mark_node)
16437 return unify_invalid (explain_p);
16439 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
16441 tree type = TREE_TYPE (elt);
16442 /* It should only be possible to get here for a call. */
16443 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
16444 elt_strict |= maybe_adjust_types_for_deduction
16445 (DEDUCE_CALL, &elttype, &type, elt);
16446 elt = type;
16449 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
16450 explain_p);
16453 /* If the std::initializer_list<T> deduction worked, replace the
16454 deduced A with std::initializer_list<A>. */
16455 if (orig_parm != parm)
16457 idx = TEMPLATE_TYPE_IDX (orig_parm);
16458 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16459 targ = listify (targ);
16460 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
16462 return unify_success (explain_p);
16465 /* Immediately reject some pairs that won't unify because of
16466 cv-qualification mismatches. */
16467 if (TREE_CODE (arg) == TREE_CODE (parm)
16468 && TYPE_P (arg)
16469 /* It is the elements of the array which hold the cv quals of an array
16470 type, and the elements might be template type parms. We'll check
16471 when we recurse. */
16472 && TREE_CODE (arg) != ARRAY_TYPE
16473 /* We check the cv-qualifiers when unifying with template type
16474 parameters below. We want to allow ARG `const T' to unify with
16475 PARM `T' for example, when computing which of two templates
16476 is more specialized, for example. */
16477 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
16478 && !check_cv_quals_for_unify (strict_in, arg, parm))
16479 return unify_cv_qual_mismatch (explain_p, parm, arg);
16481 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
16482 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
16483 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
16484 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
16485 strict &= ~UNIFY_ALLOW_DERIVED;
16486 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
16487 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
16489 switch (TREE_CODE (parm))
16491 case TYPENAME_TYPE:
16492 case SCOPE_REF:
16493 case UNBOUND_CLASS_TEMPLATE:
16494 /* In a type which contains a nested-name-specifier, template
16495 argument values cannot be deduced for template parameters used
16496 within the nested-name-specifier. */
16497 return unify_success (explain_p);
16499 case TEMPLATE_TYPE_PARM:
16500 case TEMPLATE_TEMPLATE_PARM:
16501 case BOUND_TEMPLATE_TEMPLATE_PARM:
16502 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16503 if (tparm == error_mark_node)
16504 return unify_invalid (explain_p);
16506 if (TEMPLATE_TYPE_LEVEL (parm)
16507 != template_decl_level (tparm))
16508 /* The PARM is not one we're trying to unify. Just check
16509 to see if it matches ARG. */
16511 if (TREE_CODE (arg) == TREE_CODE (parm)
16512 && (is_auto (parm) ? is_auto (arg)
16513 : same_type_p (parm, arg)))
16514 return unify_success (explain_p);
16515 else
16516 return unify_type_mismatch (explain_p, parm, arg);
16518 idx = TEMPLATE_TYPE_IDX (parm);
16519 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16520 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
16521 if (tparm == error_mark_node)
16522 return unify_invalid (explain_p);
16524 /* Check for mixed types and values. */
16525 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16526 && TREE_CODE (tparm) != TYPE_DECL)
16527 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16528 && TREE_CODE (tparm) != TEMPLATE_DECL))
16529 gcc_unreachable ();
16531 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16533 /* ARG must be constructed from a template class or a template
16534 template parameter. */
16535 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
16536 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
16537 return unify_template_deduction_failure (explain_p, parm, arg);
16540 tree parmvec = TYPE_TI_ARGS (parm);
16541 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
16542 tree full_argvec = add_to_template_args (targs, argvec);
16543 tree parm_parms
16544 = DECL_INNERMOST_TEMPLATE_PARMS
16545 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
16546 int i, len;
16547 int parm_variadic_p = 0;
16549 /* The resolution to DR150 makes clear that default
16550 arguments for an N-argument may not be used to bind T
16551 to a template template parameter with fewer than N
16552 parameters. It is not safe to permit the binding of
16553 default arguments as an extension, as that may change
16554 the meaning of a conforming program. Consider:
16556 struct Dense { static const unsigned int dim = 1; };
16558 template <template <typename> class View,
16559 typename Block>
16560 void operator+(float, View<Block> const&);
16562 template <typename Block,
16563 unsigned int Dim = Block::dim>
16564 struct Lvalue_proxy { operator float() const; };
16566 void
16567 test_1d (void) {
16568 Lvalue_proxy<Dense> p;
16569 float b;
16570 b + p;
16573 Here, if Lvalue_proxy is permitted to bind to View, then
16574 the global operator+ will be used; if they are not, the
16575 Lvalue_proxy will be converted to float. */
16576 if (coerce_template_parms (parm_parms,
16577 full_argvec,
16578 TYPE_TI_TEMPLATE (parm),
16579 (explain_p
16580 ? tf_warning_or_error
16581 : tf_none),
16582 /*require_all_args=*/true,
16583 /*use_default_args=*/false)
16584 == error_mark_node)
16585 return 1;
16587 /* Deduce arguments T, i from TT<T> or TT<i>.
16588 We check each element of PARMVEC and ARGVEC individually
16589 rather than the whole TREE_VEC since they can have
16590 different number of elements. */
16592 parmvec = expand_template_argument_pack (parmvec);
16593 argvec = expand_template_argument_pack (argvec);
16595 len = TREE_VEC_LENGTH (parmvec);
16597 /* Check if the parameters end in a pack, making them
16598 variadic. */
16599 if (len > 0
16600 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
16601 parm_variadic_p = 1;
16603 for (i = 0; i < len - parm_variadic_p; ++i)
16604 /* If the template argument list of P contains a pack
16605 expansion that is not the last template argument, the
16606 entire template argument list is a non-deduced
16607 context. */
16608 if (PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, i)))
16609 return unify_success (explain_p);
16611 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
16612 return unify_too_few_arguments (explain_p,
16613 TREE_VEC_LENGTH (argvec), len);
16615 for (i = 0; i < len - parm_variadic_p; ++i)
16617 RECUR_AND_CHECK_FAILURE (tparms, targs,
16618 TREE_VEC_ELT (parmvec, i),
16619 TREE_VEC_ELT (argvec, i),
16620 UNIFY_ALLOW_NONE, explain_p);
16623 if (parm_variadic_p
16624 && unify_pack_expansion (tparms, targs,
16625 parmvec, argvec,
16626 DEDUCE_EXACT,
16627 /*subr=*/true, explain_p))
16628 return 1;
16630 arg = TYPE_TI_TEMPLATE (arg);
16632 /* Fall through to deduce template name. */
16635 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16636 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16638 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16640 /* Simple cases: Value already set, does match or doesn't. */
16641 if (targ != NULL_TREE && template_args_equal (targ, arg))
16642 return unify_success (explain_p);
16643 else if (targ)
16644 return unify_inconsistency (explain_p, parm, targ, arg);
16646 else
16648 /* If PARM is `const T' and ARG is only `int', we don't have
16649 a match unless we are allowing additional qualification.
16650 If ARG is `const int' and PARM is just `T' that's OK;
16651 that binds `const int' to `T'. */
16652 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
16653 arg, parm))
16654 return unify_cv_qual_mismatch (explain_p, parm, arg);
16656 /* Consider the case where ARG is `const volatile int' and
16657 PARM is `const T'. Then, T should be `volatile int'. */
16658 arg = cp_build_qualified_type_real
16659 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
16660 if (arg == error_mark_node)
16661 return unify_invalid (explain_p);
16663 /* Simple cases: Value already set, does match or doesn't. */
16664 if (targ != NULL_TREE && same_type_p (targ, arg))
16665 return unify_success (explain_p);
16666 else if (targ)
16667 return unify_inconsistency (explain_p, parm, targ, arg);
16669 /* Make sure that ARG is not a variable-sized array. (Note
16670 that were talking about variable-sized arrays (like
16671 `int[n]'), rather than arrays of unknown size (like
16672 `int[]').) We'll get very confused by such a type since
16673 the bound of the array is not constant, and therefore
16674 not mangleable. Besides, such types are not allowed in
16675 ISO C++, so we can do as we please here. We do allow
16676 them for 'auto' deduction, since that isn't ABI-exposed. */
16677 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
16678 return unify_vla_arg (explain_p, arg);
16680 /* Strip typedefs as in convert_template_argument. */
16681 arg = canonicalize_type_argument (arg, tf_none);
16684 /* If ARG is a parameter pack or an expansion, we cannot unify
16685 against it unless PARM is also a parameter pack. */
16686 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16687 && !template_parameter_pack_p (parm))
16688 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16690 /* If the argument deduction results is a METHOD_TYPE,
16691 then there is a problem.
16692 METHOD_TYPE doesn't map to any real C++ type the result of
16693 the deduction can not be of that type. */
16694 if (TREE_CODE (arg) == METHOD_TYPE)
16695 return unify_method_type_error (explain_p, arg);
16697 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16698 return unify_success (explain_p);
16700 case TEMPLATE_PARM_INDEX:
16701 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16702 if (tparm == error_mark_node)
16703 return unify_invalid (explain_p);
16705 if (TEMPLATE_PARM_LEVEL (parm)
16706 != template_decl_level (tparm))
16708 /* The PARM is not one we're trying to unify. Just check
16709 to see if it matches ARG. */
16710 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
16711 && cp_tree_equal (parm, arg));
16712 if (result)
16713 unify_expression_unequal (explain_p, parm, arg);
16714 return result;
16717 idx = TEMPLATE_PARM_IDX (parm);
16718 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16720 if (targ)
16722 int x = !cp_tree_equal (targ, arg);
16723 if (x)
16724 unify_inconsistency (explain_p, parm, targ, arg);
16725 return x;
16728 /* [temp.deduct.type] If, in the declaration of a function template
16729 with a non-type template-parameter, the non-type
16730 template-parameter is used in an expression in the function
16731 parameter-list and, if the corresponding template-argument is
16732 deduced, the template-argument type shall match the type of the
16733 template-parameter exactly, except that a template-argument
16734 deduced from an array bound may be of any integral type.
16735 The non-type parameter might use already deduced type parameters. */
16736 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
16737 if (!TREE_TYPE (arg))
16738 /* Template-parameter dependent expression. Just accept it for now.
16739 It will later be processed in convert_template_argument. */
16741 else if (same_type_p (TREE_TYPE (arg), tparm))
16742 /* OK */;
16743 else if ((strict & UNIFY_ALLOW_INTEGER)
16744 && (TREE_CODE (tparm) == INTEGER_TYPE
16745 || TREE_CODE (tparm) == BOOLEAN_TYPE))
16746 /* Convert the ARG to the type of PARM; the deduced non-type
16747 template argument must exactly match the types of the
16748 corresponding parameter. */
16749 arg = fold (build_nop (tparm, arg));
16750 else if (uses_template_parms (tparm))
16751 /* We haven't deduced the type of this parameter yet. Try again
16752 later. */
16753 return unify_success (explain_p);
16754 else
16755 return unify_type_mismatch (explain_p, tparm, arg);
16757 /* If ARG is a parameter pack or an expansion, we cannot unify
16758 against it unless PARM is also a parameter pack. */
16759 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16760 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
16761 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16763 arg = strip_typedefs_expr (arg);
16764 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16765 return unify_success (explain_p);
16767 case PTRMEM_CST:
16769 /* A pointer-to-member constant can be unified only with
16770 another constant. */
16771 if (TREE_CODE (arg) != PTRMEM_CST)
16772 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
16774 /* Just unify the class member. It would be useless (and possibly
16775 wrong, depending on the strict flags) to unify also
16776 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16777 arg refer to the same variable, even if through different
16778 classes. For instance:
16780 struct A { int x; };
16781 struct B : A { };
16783 Unification of &A::x and &B::x must succeed. */
16784 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
16785 PTRMEM_CST_MEMBER (arg), strict, explain_p);
16788 case POINTER_TYPE:
16790 if (TREE_CODE (arg) != POINTER_TYPE)
16791 return unify_type_mismatch (explain_p, parm, arg);
16793 /* [temp.deduct.call]
16795 A can be another pointer or pointer to member type that can
16796 be converted to the deduced A via a qualification
16797 conversion (_conv.qual_).
16799 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16800 This will allow for additional cv-qualification of the
16801 pointed-to types if appropriate. */
16803 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
16804 /* The derived-to-base conversion only persists through one
16805 level of pointers. */
16806 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
16808 return unify (tparms, targs, TREE_TYPE (parm),
16809 TREE_TYPE (arg), strict, explain_p);
16812 case REFERENCE_TYPE:
16813 if (TREE_CODE (arg) != REFERENCE_TYPE)
16814 return unify_type_mismatch (explain_p, parm, arg);
16815 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16816 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16818 case ARRAY_TYPE:
16819 if (TREE_CODE (arg) != ARRAY_TYPE)
16820 return unify_type_mismatch (explain_p, parm, arg);
16821 if ((TYPE_DOMAIN (parm) == NULL_TREE)
16822 != (TYPE_DOMAIN (arg) == NULL_TREE))
16823 return unify_type_mismatch (explain_p, parm, arg);
16824 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16825 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16826 if (TYPE_DOMAIN (parm) != NULL_TREE)
16828 tree parm_max;
16829 tree arg_max;
16830 bool parm_cst;
16831 bool arg_cst;
16833 /* Our representation of array types uses "N - 1" as the
16834 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16835 not an integer constant. We cannot unify arbitrarily
16836 complex expressions, so we eliminate the MINUS_EXPRs
16837 here. */
16838 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
16839 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
16840 if (!parm_cst)
16842 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
16843 parm_max = TREE_OPERAND (parm_max, 0);
16845 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
16846 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
16847 if (!arg_cst)
16849 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16850 trying to unify the type of a variable with the type
16851 of a template parameter. For example:
16853 template <unsigned int N>
16854 void f (char (&) [N]);
16855 int g();
16856 void h(int i) {
16857 char a[g(i)];
16858 f(a);
16861 Here, the type of the ARG will be "int [g(i)]", and
16862 may be a SAVE_EXPR, etc. */
16863 if (TREE_CODE (arg_max) != MINUS_EXPR)
16864 return unify_vla_arg (explain_p, arg);
16865 arg_max = TREE_OPERAND (arg_max, 0);
16868 /* If only one of the bounds used a MINUS_EXPR, compensate
16869 by adding one to the other bound. */
16870 if (parm_cst && !arg_cst)
16871 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
16872 integer_type_node,
16873 parm_max,
16874 integer_one_node);
16875 else if (arg_cst && !parm_cst)
16876 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
16877 integer_type_node,
16878 arg_max,
16879 integer_one_node);
16881 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max,
16882 UNIFY_ALLOW_INTEGER, explain_p);
16884 return unify_success (explain_p);
16886 case REAL_TYPE:
16887 case COMPLEX_TYPE:
16888 case VECTOR_TYPE:
16889 case INTEGER_TYPE:
16890 case BOOLEAN_TYPE:
16891 case ENUMERAL_TYPE:
16892 case VOID_TYPE:
16893 case NULLPTR_TYPE:
16894 if (TREE_CODE (arg) != TREE_CODE (parm))
16895 return unify_type_mismatch (explain_p, parm, arg);
16897 /* We have already checked cv-qualification at the top of the
16898 function. */
16899 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
16900 return unify_type_mismatch (explain_p, parm, arg);
16902 /* As far as unification is concerned, this wins. Later checks
16903 will invalidate it if necessary. */
16904 return unify_success (explain_p);
16906 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16907 /* Type INTEGER_CST can come from ordinary constant template args. */
16908 case INTEGER_CST:
16909 while (TREE_CODE (arg) == NOP_EXPR)
16910 arg = TREE_OPERAND (arg, 0);
16912 if (TREE_CODE (arg) != INTEGER_CST)
16913 return unify_template_argument_mismatch (explain_p, parm, arg);
16914 return (tree_int_cst_equal (parm, arg)
16915 ? unify_success (explain_p)
16916 : unify_template_argument_mismatch (explain_p, parm, arg));
16918 case TREE_VEC:
16920 int i, len, argslen;
16921 int parm_variadic_p = 0;
16923 if (TREE_CODE (arg) != TREE_VEC)
16924 return unify_template_argument_mismatch (explain_p, parm, arg);
16926 len = TREE_VEC_LENGTH (parm);
16927 argslen = TREE_VEC_LENGTH (arg);
16929 /* Check for pack expansions in the parameters. */
16930 for (i = 0; i < len; ++i)
16932 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
16934 if (i == len - 1)
16935 /* We can unify against something with a trailing
16936 parameter pack. */
16937 parm_variadic_p = 1;
16938 else
16939 /* [temp.deduct.type]/9: If the template argument list of
16940 P contains a pack expansion that is not the last
16941 template argument, the entire template argument list
16942 is a non-deduced context. */
16943 return unify_success (explain_p);
16947 /* If we don't have enough arguments to satisfy the parameters
16948 (not counting the pack expression at the end), or we have
16949 too many arguments for a parameter list that doesn't end in
16950 a pack expression, we can't unify. */
16951 if (parm_variadic_p
16952 ? argslen < len - parm_variadic_p
16953 : argslen != len)
16954 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
16956 /* Unify all of the parameters that precede the (optional)
16957 pack expression. */
16958 for (i = 0; i < len - parm_variadic_p; ++i)
16960 RECUR_AND_CHECK_FAILURE (tparms, targs,
16961 TREE_VEC_ELT (parm, i),
16962 TREE_VEC_ELT (arg, i),
16963 UNIFY_ALLOW_NONE, explain_p);
16965 if (parm_variadic_p)
16966 return unify_pack_expansion (tparms, targs, parm, arg,
16967 DEDUCE_EXACT,
16968 /*subr=*/true, explain_p);
16969 return unify_success (explain_p);
16972 case RECORD_TYPE:
16973 case UNION_TYPE:
16974 if (TREE_CODE (arg) != TREE_CODE (parm))
16975 return unify_type_mismatch (explain_p, parm, arg);
16977 if (TYPE_PTRMEMFUNC_P (parm))
16979 if (!TYPE_PTRMEMFUNC_P (arg))
16980 return unify_type_mismatch (explain_p, parm, arg);
16982 return unify (tparms, targs,
16983 TYPE_PTRMEMFUNC_FN_TYPE (parm),
16984 TYPE_PTRMEMFUNC_FN_TYPE (arg),
16985 strict, explain_p);
16988 if (CLASSTYPE_TEMPLATE_INFO (parm))
16990 tree t = NULL_TREE;
16992 if (strict_in & UNIFY_ALLOW_DERIVED)
16994 /* First, we try to unify the PARM and ARG directly. */
16995 t = try_class_unification (tparms, targs,
16996 parm, arg, explain_p);
16998 if (!t)
17000 /* Fallback to the special case allowed in
17001 [temp.deduct.call]:
17003 If P is a class, and P has the form
17004 template-id, then A can be a derived class of
17005 the deduced A. Likewise, if P is a pointer to
17006 a class of the form template-id, A can be a
17007 pointer to a derived class pointed to by the
17008 deduced A. */
17009 enum template_base_result r;
17010 r = get_template_base (tparms, targs, parm, arg,
17011 explain_p, &t);
17013 if (!t)
17014 return unify_no_common_base (explain_p, r, parm, arg);
17017 else if (CLASSTYPE_TEMPLATE_INFO (arg)
17018 && (CLASSTYPE_TI_TEMPLATE (parm)
17019 == CLASSTYPE_TI_TEMPLATE (arg)))
17020 /* Perhaps PARM is something like S<U> and ARG is S<int>.
17021 Then, we should unify `int' and `U'. */
17022 t = arg;
17023 else
17024 /* There's no chance of unification succeeding. */
17025 return unify_type_mismatch (explain_p, parm, arg);
17027 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
17028 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
17030 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
17031 return unify_type_mismatch (explain_p, parm, arg);
17032 return unify_success (explain_p);
17034 case METHOD_TYPE:
17035 case FUNCTION_TYPE:
17037 unsigned int nargs;
17038 tree *args;
17039 tree a;
17040 unsigned int i;
17042 if (TREE_CODE (arg) != TREE_CODE (parm))
17043 return unify_type_mismatch (explain_p, parm, arg);
17045 /* CV qualifications for methods can never be deduced, they must
17046 match exactly. We need to check them explicitly here,
17047 because type_unification_real treats them as any other
17048 cv-qualified parameter. */
17049 if (TREE_CODE (parm) == METHOD_TYPE
17050 && (!check_cv_quals_for_unify
17051 (UNIFY_ALLOW_NONE,
17052 class_of_this_parm (arg),
17053 class_of_this_parm (parm))))
17054 return unify_cv_qual_mismatch (explain_p, parm, arg);
17056 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
17057 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
17059 nargs = list_length (TYPE_ARG_TYPES (arg));
17060 args = XALLOCAVEC (tree, nargs);
17061 for (a = TYPE_ARG_TYPES (arg), i = 0;
17062 a != NULL_TREE && a != void_list_node;
17063 a = TREE_CHAIN (a), ++i)
17064 args[i] = TREE_VALUE (a);
17065 nargs = i;
17067 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
17068 args, nargs, 1, DEDUCE_EXACT,
17069 LOOKUP_NORMAL, explain_p);
17072 case OFFSET_TYPE:
17073 /* Unify a pointer to member with a pointer to member function, which
17074 deduces the type of the member as a function type. */
17075 if (TYPE_PTRMEMFUNC_P (arg))
17077 tree method_type;
17078 tree fntype;
17080 /* Check top-level cv qualifiers */
17081 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
17082 return unify_cv_qual_mismatch (explain_p, parm, arg);
17084 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
17085 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
17086 UNIFY_ALLOW_NONE, explain_p);
17088 /* Determine the type of the function we are unifying against. */
17089 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
17090 fntype =
17091 build_function_type (TREE_TYPE (method_type),
17092 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
17094 /* Extract the cv-qualifiers of the member function from the
17095 implicit object parameter and place them on the function
17096 type to be restored later. */
17097 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
17098 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
17101 if (TREE_CODE (arg) != OFFSET_TYPE)
17102 return unify_type_mismatch (explain_p, parm, arg);
17103 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
17104 TYPE_OFFSET_BASETYPE (arg),
17105 UNIFY_ALLOW_NONE, explain_p);
17106 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
17107 strict, explain_p);
17109 case CONST_DECL:
17110 if (DECL_TEMPLATE_PARM_P (parm))
17111 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
17112 if (arg != integral_constant_value (parm))
17113 return unify_template_argument_mismatch (explain_p, parm, arg);
17114 return unify_success (explain_p);
17116 case FIELD_DECL:
17117 case TEMPLATE_DECL:
17118 /* Matched cases are handled by the ARG == PARM test above. */
17119 return unify_template_argument_mismatch (explain_p, parm, arg);
17121 case VAR_DECL:
17122 /* A non-type template parameter that is a variable should be a
17123 an integral constant, in which case, it whould have been
17124 folded into its (constant) value. So we should not be getting
17125 a variable here. */
17126 gcc_unreachable ();
17128 case TYPE_ARGUMENT_PACK:
17129 case NONTYPE_ARGUMENT_PACK:
17130 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
17131 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
17133 case TYPEOF_TYPE:
17134 case DECLTYPE_TYPE:
17135 case UNDERLYING_TYPE:
17136 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
17137 or UNDERLYING_TYPE nodes. */
17138 return unify_success (explain_p);
17140 case ERROR_MARK:
17141 /* Unification fails if we hit an error node. */
17142 return unify_invalid (explain_p);
17144 default:
17145 /* An unresolved overload is a nondeduced context. */
17146 if (is_overloaded_fn (parm) || type_unknown_p (parm))
17147 return unify_success (explain_p);
17148 gcc_assert (EXPR_P (parm));
17150 /* We must be looking at an expression. This can happen with
17151 something like:
17153 template <int I>
17154 void foo(S<I>, S<I + 2>);
17156 This is a "nondeduced context":
17158 [deduct.type]
17160 The nondeduced contexts are:
17162 --A type that is a template-id in which one or more of
17163 the template-arguments is an expression that references
17164 a template-parameter.
17166 In these cases, we assume deduction succeeded, but don't
17167 actually infer any unifications. */
17169 if (!uses_template_parms (parm)
17170 && !template_args_equal (parm, arg))
17171 return unify_expression_unequal (explain_p, parm, arg);
17172 else
17173 return unify_success (explain_p);
17176 #undef RECUR_AND_CHECK_FAILURE
17178 /* Note that DECL can be defined in this translation unit, if
17179 required. */
17181 static void
17182 mark_definable (tree decl)
17184 tree clone;
17185 DECL_NOT_REALLY_EXTERN (decl) = 1;
17186 FOR_EACH_CLONE (clone, decl)
17187 DECL_NOT_REALLY_EXTERN (clone) = 1;
17190 /* Called if RESULT is explicitly instantiated, or is a member of an
17191 explicitly instantiated class. */
17193 void
17194 mark_decl_instantiated (tree result, int extern_p)
17196 SET_DECL_EXPLICIT_INSTANTIATION (result);
17198 /* If this entity has already been written out, it's too late to
17199 make any modifications. */
17200 if (TREE_ASM_WRITTEN (result))
17201 return;
17203 if (TREE_CODE (result) != FUNCTION_DECL)
17204 /* The TREE_PUBLIC flag for function declarations will have been
17205 set correctly by tsubst. */
17206 TREE_PUBLIC (result) = 1;
17208 /* This might have been set by an earlier implicit instantiation. */
17209 DECL_COMDAT (result) = 0;
17211 if (extern_p)
17212 DECL_NOT_REALLY_EXTERN (result) = 0;
17213 else
17215 mark_definable (result);
17216 /* Always make artificials weak. */
17217 if (DECL_ARTIFICIAL (result) && flag_weak)
17218 comdat_linkage (result);
17219 /* For WIN32 we also want to put explicit instantiations in
17220 linkonce sections. */
17221 else if (TREE_PUBLIC (result))
17222 maybe_make_one_only (result);
17225 /* If EXTERN_P, then this function will not be emitted -- unless
17226 followed by an explicit instantiation, at which point its linkage
17227 will be adjusted. If !EXTERN_P, then this function will be
17228 emitted here. In neither circumstance do we want
17229 import_export_decl to adjust the linkage. */
17230 DECL_INTERFACE_KNOWN (result) = 1;
17233 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17234 important template arguments. If any are missing, we check whether
17235 they're important by using error_mark_node for substituting into any
17236 args that were used for partial ordering (the ones between ARGS and END)
17237 and seeing if it bubbles up. */
17239 static bool
17240 check_undeduced_parms (tree targs, tree args, tree end)
17242 bool found = false;
17243 int i;
17244 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
17245 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
17247 found = true;
17248 TREE_VEC_ELT (targs, i) = error_mark_node;
17250 if (found)
17252 tree substed = tsubst_arg_types (args, targs, end, tf_none, NULL_TREE);
17253 if (substed == error_mark_node)
17254 return true;
17256 return false;
17259 /* Given two function templates PAT1 and PAT2, return:
17261 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17262 -1 if PAT2 is more specialized than PAT1.
17263 0 if neither is more specialized.
17265 LEN indicates the number of parameters we should consider
17266 (defaulted parameters should not be considered).
17268 The 1998 std underspecified function template partial ordering, and
17269 DR214 addresses the issue. We take pairs of arguments, one from
17270 each of the templates, and deduce them against each other. One of
17271 the templates will be more specialized if all the *other*
17272 template's arguments deduce against its arguments and at least one
17273 of its arguments *does* *not* deduce against the other template's
17274 corresponding argument. Deduction is done as for class templates.
17275 The arguments used in deduction have reference and top level cv
17276 qualifiers removed. Iff both arguments were originally reference
17277 types *and* deduction succeeds in both directions, the template
17278 with the more cv-qualified argument wins for that pairing (if
17279 neither is more cv-qualified, they both are equal). Unlike regular
17280 deduction, after all the arguments have been deduced in this way,
17281 we do *not* verify the deduced template argument values can be
17282 substituted into non-deduced contexts.
17284 The logic can be a bit confusing here, because we look at deduce1 and
17285 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17286 can find template arguments for pat1 to make arg1 look like arg2, that
17287 means that arg2 is at least as specialized as arg1. */
17290 more_specialized_fn (tree pat1, tree pat2, int len)
17292 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
17293 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
17294 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
17295 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
17296 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
17297 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
17298 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
17299 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
17300 tree origs1, origs2;
17301 bool lose1 = false;
17302 bool lose2 = false;
17304 /* Remove the this parameter from non-static member functions. If
17305 one is a non-static member function and the other is not a static
17306 member function, remove the first parameter from that function
17307 also. This situation occurs for operator functions where we
17308 locate both a member function (with this pointer) and non-member
17309 operator (with explicit first operand). */
17310 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
17312 len--; /* LEN is the number of significant arguments for DECL1 */
17313 args1 = TREE_CHAIN (args1);
17314 if (!DECL_STATIC_FUNCTION_P (decl2))
17315 args2 = TREE_CHAIN (args2);
17317 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
17319 args2 = TREE_CHAIN (args2);
17320 if (!DECL_STATIC_FUNCTION_P (decl1))
17322 len--;
17323 args1 = TREE_CHAIN (args1);
17327 /* If only one is a conversion operator, they are unordered. */
17328 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
17329 return 0;
17331 /* Consider the return type for a conversion function */
17332 if (DECL_CONV_FN_P (decl1))
17334 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
17335 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
17336 len++;
17339 processing_template_decl++;
17341 origs1 = args1;
17342 origs2 = args2;
17344 while (len--
17345 /* Stop when an ellipsis is seen. */
17346 && args1 != NULL_TREE && args2 != NULL_TREE)
17348 tree arg1 = TREE_VALUE (args1);
17349 tree arg2 = TREE_VALUE (args2);
17350 int deduce1, deduce2;
17351 int quals1 = -1;
17352 int quals2 = -1;
17354 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17355 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17357 /* When both arguments are pack expansions, we need only
17358 unify the patterns themselves. */
17359 arg1 = PACK_EXPANSION_PATTERN (arg1);
17360 arg2 = PACK_EXPANSION_PATTERN (arg2);
17362 /* This is the last comparison we need to do. */
17363 len = 0;
17366 if (TREE_CODE (arg1) == REFERENCE_TYPE)
17368 arg1 = TREE_TYPE (arg1);
17369 quals1 = cp_type_quals (arg1);
17372 if (TREE_CODE (arg2) == REFERENCE_TYPE)
17374 arg2 = TREE_TYPE (arg2);
17375 quals2 = cp_type_quals (arg2);
17378 arg1 = TYPE_MAIN_VARIANT (arg1);
17379 arg2 = TYPE_MAIN_VARIANT (arg2);
17381 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
17383 int i, len2 = list_length (args2);
17384 tree parmvec = make_tree_vec (1);
17385 tree argvec = make_tree_vec (len2);
17386 tree ta = args2;
17388 /* Setup the parameter vector, which contains only ARG1. */
17389 TREE_VEC_ELT (parmvec, 0) = arg1;
17391 /* Setup the argument vector, which contains the remaining
17392 arguments. */
17393 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
17394 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17396 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
17397 argvec, DEDUCE_EXACT,
17398 /*subr=*/true, /*explain_p=*/false)
17399 == 0);
17401 /* We cannot deduce in the other direction, because ARG1 is
17402 a pack expansion but ARG2 is not. */
17403 deduce2 = 0;
17405 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17407 int i, len1 = list_length (args1);
17408 tree parmvec = make_tree_vec (1);
17409 tree argvec = make_tree_vec (len1);
17410 tree ta = args1;
17412 /* Setup the parameter vector, which contains only ARG1. */
17413 TREE_VEC_ELT (parmvec, 0) = arg2;
17415 /* Setup the argument vector, which contains the remaining
17416 arguments. */
17417 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
17418 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17420 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
17421 argvec, DEDUCE_EXACT,
17422 /*subr=*/true, /*explain_p=*/false)
17423 == 0);
17425 /* We cannot deduce in the other direction, because ARG2 is
17426 a pack expansion but ARG1 is not.*/
17427 deduce1 = 0;
17430 else
17432 /* The normal case, where neither argument is a pack
17433 expansion. */
17434 deduce1 = (unify (tparms1, targs1, arg1, arg2,
17435 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17436 == 0);
17437 deduce2 = (unify (tparms2, targs2, arg2, arg1,
17438 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17439 == 0);
17442 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17443 arg2, then arg2 is not as specialized as arg1. */
17444 if (!deduce1)
17445 lose2 = true;
17446 if (!deduce2)
17447 lose1 = true;
17449 /* "If, for a given type, deduction succeeds in both directions
17450 (i.e., the types are identical after the transformations above)
17451 and if the type from the argument template is more cv-qualified
17452 than the type from the parameter template (as described above)
17453 that type is considered to be more specialized than the other. If
17454 neither type is more cv-qualified than the other then neither type
17455 is more specialized than the other." */
17457 if (deduce1 && deduce2
17458 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
17460 if ((quals1 & quals2) == quals2)
17461 lose2 = true;
17462 if ((quals1 & quals2) == quals1)
17463 lose1 = true;
17466 if (lose1 && lose2)
17467 /* We've failed to deduce something in either direction.
17468 These must be unordered. */
17469 break;
17471 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17472 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17473 /* We have already processed all of the arguments in our
17474 handing of the pack expansion type. */
17475 len = 0;
17477 args1 = TREE_CHAIN (args1);
17478 args2 = TREE_CHAIN (args2);
17481 /* "In most cases, all template parameters must have values in order for
17482 deduction to succeed, but for partial ordering purposes a template
17483 parameter may remain without a value provided it is not used in the
17484 types being used for partial ordering."
17486 Thus, if we are missing any of the targs1 we need to substitute into
17487 origs1, then pat2 is not as specialized as pat1. This can happen when
17488 there is a nondeduced context. */
17489 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
17490 lose2 = true;
17491 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
17492 lose1 = true;
17494 processing_template_decl--;
17496 /* All things being equal, if the next argument is a pack expansion
17497 for one function but not for the other, prefer the
17498 non-variadic function. FIXME this is bogus; see c++/41958. */
17499 if (lose1 == lose2
17500 && args1 && TREE_VALUE (args1)
17501 && args2 && TREE_VALUE (args2))
17503 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
17504 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
17507 if (lose1 == lose2)
17508 return 0;
17509 else if (!lose1)
17510 return 1;
17511 else
17512 return -1;
17515 /* Determine which of two partial specializations of MAIN_TMPL is more
17516 specialized.
17518 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17519 to the first partial specialization. The TREE_VALUE is the
17520 innermost set of template parameters for the partial
17521 specialization. PAT2 is similar, but for the second template.
17523 Return 1 if the first partial specialization is more specialized;
17524 -1 if the second is more specialized; 0 if neither is more
17525 specialized.
17527 See [temp.class.order] for information about determining which of
17528 two templates is more specialized. */
17530 static int
17531 more_specialized_class (tree main_tmpl, tree pat1, tree pat2)
17533 tree targs;
17534 tree tmpl1, tmpl2;
17535 int winner = 0;
17536 bool any_deductions = false;
17538 tmpl1 = TREE_TYPE (pat1);
17539 tmpl2 = TREE_TYPE (pat2);
17541 /* Just like what happens for functions, if we are ordering between
17542 different class template specializations, we may encounter dependent
17543 types in the arguments, and we need our dependency check functions
17544 to behave correctly. */
17545 ++processing_template_decl;
17546 targs = get_class_bindings (main_tmpl, TREE_VALUE (pat1),
17547 CLASSTYPE_TI_ARGS (tmpl1),
17548 CLASSTYPE_TI_ARGS (tmpl2));
17549 if (targs)
17551 --winner;
17552 any_deductions = true;
17555 targs = get_class_bindings (main_tmpl, TREE_VALUE (pat2),
17556 CLASSTYPE_TI_ARGS (tmpl2),
17557 CLASSTYPE_TI_ARGS (tmpl1));
17558 if (targs)
17560 ++winner;
17561 any_deductions = true;
17563 --processing_template_decl;
17565 /* In the case of a tie where at least one of the class templates
17566 has a parameter pack at the end, the template with the most
17567 non-packed parameters wins. */
17568 if (winner == 0
17569 && any_deductions
17570 && (template_args_variadic_p (TREE_PURPOSE (pat1))
17571 || template_args_variadic_p (TREE_PURPOSE (pat2))))
17573 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
17574 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
17575 int len1 = TREE_VEC_LENGTH (args1);
17576 int len2 = TREE_VEC_LENGTH (args2);
17578 /* We don't count the pack expansion at the end. */
17579 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
17580 --len1;
17581 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
17582 --len2;
17584 if (len1 > len2)
17585 return 1;
17586 else if (len1 < len2)
17587 return -1;
17590 return winner;
17593 /* Return the template arguments that will produce the function signature
17594 DECL from the function template FN, with the explicit template
17595 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17596 also match. Return NULL_TREE if no satisfactory arguments could be
17597 found. */
17599 static tree
17600 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
17602 int ntparms = DECL_NTPARMS (fn);
17603 tree targs = make_tree_vec (ntparms);
17604 tree decl_type = TREE_TYPE (decl);
17605 tree decl_arg_types;
17606 tree *args;
17607 unsigned int nargs, ix;
17608 tree arg;
17610 gcc_assert (decl != DECL_TEMPLATE_RESULT (fn));
17612 /* Never do unification on the 'this' parameter. */
17613 decl_arg_types = skip_artificial_parms_for (decl,
17614 TYPE_ARG_TYPES (decl_type));
17616 nargs = list_length (decl_arg_types);
17617 args = XALLOCAVEC (tree, nargs);
17618 for (arg = decl_arg_types, ix = 0;
17619 arg != NULL_TREE && arg != void_list_node;
17620 arg = TREE_CHAIN (arg), ++ix)
17621 args[ix] = TREE_VALUE (arg);
17623 if (fn_type_unification (fn, explicit_args, targs,
17624 args, ix,
17625 (check_rettype || DECL_CONV_FN_P (fn)
17626 ? TREE_TYPE (decl_type) : NULL_TREE),
17627 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false)
17628 == error_mark_node)
17629 return NULL_TREE;
17631 return targs;
17634 /* Return the innermost template arguments that, when applied to a partial
17635 specialization of MAIN_TMPL whose innermost template parameters are
17636 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17637 ARGS.
17639 For example, suppose we have:
17641 template <class T, class U> struct S {};
17642 template <class T> struct S<T*, int> {};
17644 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17645 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17646 int}. The resulting vector will be {double}, indicating that `T'
17647 is bound to `double'. */
17649 static tree
17650 get_class_bindings (tree main_tmpl, tree tparms, tree spec_args, tree args)
17652 int i, ntparms = TREE_VEC_LENGTH (tparms);
17653 tree deduced_args;
17654 tree innermost_deduced_args;
17656 innermost_deduced_args = make_tree_vec (ntparms);
17657 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17659 deduced_args = copy_node (args);
17660 SET_TMPL_ARGS_LEVEL (deduced_args,
17661 TMPL_ARGS_DEPTH (deduced_args),
17662 innermost_deduced_args);
17664 else
17665 deduced_args = innermost_deduced_args;
17667 if (unify (tparms, deduced_args,
17668 INNERMOST_TEMPLATE_ARGS (spec_args),
17669 INNERMOST_TEMPLATE_ARGS (args),
17670 UNIFY_ALLOW_NONE, /*explain_p=*/false))
17671 return NULL_TREE;
17673 for (i = 0; i < ntparms; ++i)
17674 if (! TREE_VEC_ELT (innermost_deduced_args, i))
17675 return NULL_TREE;
17677 /* Verify that nondeduced template arguments agree with the type
17678 obtained from argument deduction.
17680 For example:
17682 struct A { typedef int X; };
17683 template <class T, class U> struct C {};
17684 template <class T> struct C<T, typename T::X> {};
17686 Then with the instantiation `C<A, int>', we can deduce that
17687 `T' is `A' but unify () does not check whether `typename T::X'
17688 is `int'. */
17689 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
17690 spec_args = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (main_tmpl),
17691 spec_args, main_tmpl,
17692 tf_none, false, false);
17693 if (spec_args == error_mark_node
17694 /* We only need to check the innermost arguments; the other
17695 arguments will always agree. */
17696 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
17697 INNERMOST_TEMPLATE_ARGS (args)))
17698 return NULL_TREE;
17700 /* Now that we have bindings for all of the template arguments,
17701 ensure that the arguments deduced for the template template
17702 parameters have compatible template parameter lists. See the use
17703 of template_template_parm_bindings_ok_p in fn_type_unification
17704 for more information. */
17705 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
17706 return NULL_TREE;
17708 return deduced_args;
17711 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17712 Return the TREE_LIST node with the most specialized template, if
17713 any. If there is no most specialized template, the error_mark_node
17714 is returned.
17716 Note that this function does not look at, or modify, the
17717 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17718 returned is one of the elements of INSTANTIATIONS, callers may
17719 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17720 and retrieve it from the value returned. */
17722 tree
17723 most_specialized_instantiation (tree templates)
17725 tree fn, champ;
17727 ++processing_template_decl;
17729 champ = templates;
17730 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
17732 int fate = 0;
17734 if (get_bindings (TREE_VALUE (champ),
17735 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17736 NULL_TREE, /*check_ret=*/true))
17737 fate--;
17739 if (get_bindings (TREE_VALUE (fn),
17740 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17741 NULL_TREE, /*check_ret=*/true))
17742 fate++;
17744 if (fate == -1)
17745 champ = fn;
17746 else if (!fate)
17748 /* Equally specialized, move to next function. If there
17749 is no next function, nothing's most specialized. */
17750 fn = TREE_CHAIN (fn);
17751 champ = fn;
17752 if (!fn)
17753 break;
17757 if (champ)
17758 /* Now verify that champ is better than everything earlier in the
17759 instantiation list. */
17760 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
17761 if (get_bindings (TREE_VALUE (champ),
17762 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17763 NULL_TREE, /*check_ret=*/true)
17764 || !get_bindings (TREE_VALUE (fn),
17765 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17766 NULL_TREE, /*check_ret=*/true))
17768 champ = NULL_TREE;
17769 break;
17772 processing_template_decl--;
17774 if (!champ)
17775 return error_mark_node;
17777 return champ;
17780 /* If DECL is a specialization of some template, return the most
17781 general such template. Otherwise, returns NULL_TREE.
17783 For example, given:
17785 template <class T> struct S { template <class U> void f(U); };
17787 if TMPL is `template <class U> void S<int>::f(U)' this will return
17788 the full template. This function will not trace past partial
17789 specializations, however. For example, given in addition:
17791 template <class T> struct S<T*> { template <class U> void f(U); };
17793 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17794 `template <class T> template <class U> S<T*>::f(U)'. */
17796 tree
17797 most_general_template (tree decl)
17799 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17800 an immediate specialization. */
17801 if (TREE_CODE (decl) == FUNCTION_DECL)
17803 if (DECL_TEMPLATE_INFO (decl)) {
17804 decl = DECL_TI_TEMPLATE (decl);
17806 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17807 template friend. */
17808 if (TREE_CODE (decl) != TEMPLATE_DECL)
17809 return NULL_TREE;
17810 } else
17811 return NULL_TREE;
17814 /* Look for more and more general templates. */
17815 while (DECL_TEMPLATE_INFO (decl))
17817 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17818 (See cp-tree.h for details.) */
17819 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
17820 break;
17822 if (CLASS_TYPE_P (TREE_TYPE (decl))
17823 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
17824 break;
17826 /* Stop if we run into an explicitly specialized class template. */
17827 if (!DECL_NAMESPACE_SCOPE_P (decl)
17828 && DECL_CONTEXT (decl)
17829 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
17830 break;
17832 decl = DECL_TI_TEMPLATE (decl);
17835 return decl;
17838 /* Return the most specialized of the class template partial
17839 specializations of TMPL which can produce TYPE, a specialization of
17840 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17841 a _TYPE node corresponding to the partial specialization, while the
17842 TREE_PURPOSE is the set of template arguments that must be
17843 substituted into the TREE_TYPE in order to generate TYPE.
17845 If the choice of partial specialization is ambiguous, a diagnostic
17846 is issued, and the error_mark_node is returned. If there are no
17847 partial specializations of TMPL matching TYPE, then NULL_TREE is
17848 returned. */
17850 static tree
17851 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
17853 tree list = NULL_TREE;
17854 tree t;
17855 tree champ;
17856 int fate;
17857 bool ambiguous_p;
17858 tree args;
17859 tree outer_args = NULL_TREE;
17861 tmpl = most_general_template (tmpl);
17862 args = CLASSTYPE_TI_ARGS (type);
17864 /* For determining which partial specialization to use, only the
17865 innermost args are interesting. */
17866 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17868 outer_args = strip_innermost_template_args (args, 1);
17869 args = INNERMOST_TEMPLATE_ARGS (args);
17872 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
17874 tree partial_spec_args;
17875 tree spec_args;
17876 tree parms = TREE_VALUE (t);
17878 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
17880 ++processing_template_decl;
17882 if (outer_args)
17884 int i;
17886 /* Discard the outer levels of args, and then substitute in the
17887 template args from the enclosing class. */
17888 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
17889 partial_spec_args = tsubst_template_args
17890 (partial_spec_args, outer_args, tf_none, NULL_TREE);
17892 /* PARMS already refers to just the innermost parms, but the
17893 template parms in partial_spec_args had their levels lowered
17894 by tsubst, so we need to do the same for the parm list. We
17895 can't just tsubst the TREE_VEC itself, as tsubst wants to
17896 treat a TREE_VEC as an argument vector. */
17897 parms = copy_node (parms);
17898 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
17899 TREE_VEC_ELT (parms, i) =
17900 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
17904 partial_spec_args =
17905 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17906 add_to_template_args (outer_args,
17907 partial_spec_args),
17908 tmpl, tf_none,
17909 /*require_all_args=*/true,
17910 /*use_default_args=*/true);
17912 --processing_template_decl;
17914 if (partial_spec_args == error_mark_node)
17915 return error_mark_node;
17917 spec_args = get_class_bindings (tmpl, parms,
17918 partial_spec_args,
17919 args);
17920 if (spec_args)
17922 if (outer_args)
17923 spec_args = add_to_template_args (outer_args, spec_args);
17924 list = tree_cons (spec_args, TREE_VALUE (t), list);
17925 TREE_TYPE (list) = TREE_TYPE (t);
17929 if (! list)
17930 return NULL_TREE;
17932 ambiguous_p = false;
17933 t = list;
17934 champ = t;
17935 t = TREE_CHAIN (t);
17936 for (; t; t = TREE_CHAIN (t))
17938 fate = more_specialized_class (tmpl, champ, t);
17939 if (fate == 1)
17941 else
17943 if (fate == 0)
17945 t = TREE_CHAIN (t);
17946 if (! t)
17948 ambiguous_p = true;
17949 break;
17952 champ = t;
17956 if (!ambiguous_p)
17957 for (t = list; t && t != champ; t = TREE_CHAIN (t))
17959 fate = more_specialized_class (tmpl, champ, t);
17960 if (fate != 1)
17962 ambiguous_p = true;
17963 break;
17967 if (ambiguous_p)
17969 const char *str;
17970 char *spaces = NULL;
17971 if (!(complain & tf_error))
17972 return error_mark_node;
17973 error ("ambiguous class template instantiation for %q#T", type);
17974 str = ngettext ("candidate is:", "candidates are:", list_length (list));
17975 for (t = list; t; t = TREE_CHAIN (t))
17977 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
17978 spaces = spaces ? spaces : get_spaces (str);
17980 free (spaces);
17981 return error_mark_node;
17984 return champ;
17987 /* Explicitly instantiate DECL. */
17989 void
17990 do_decl_instantiation (tree decl, tree storage)
17992 tree result = NULL_TREE;
17993 int extern_p = 0;
17995 if (!decl || decl == error_mark_node)
17996 /* An error occurred, for which grokdeclarator has already issued
17997 an appropriate message. */
17998 return;
17999 else if (! DECL_LANG_SPECIFIC (decl))
18001 error ("explicit instantiation of non-template %q#D", decl);
18002 return;
18004 else if (TREE_CODE (decl) == VAR_DECL)
18006 /* There is an asymmetry here in the way VAR_DECLs and
18007 FUNCTION_DECLs are handled by grokdeclarator. In the case of
18008 the latter, the DECL we get back will be marked as a
18009 template instantiation, and the appropriate
18010 DECL_TEMPLATE_INFO will be set up. This does not happen for
18011 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
18012 should handle VAR_DECLs as it currently handles
18013 FUNCTION_DECLs. */
18014 if (!DECL_CLASS_SCOPE_P (decl))
18016 error ("%qD is not a static data member of a class template", decl);
18017 return;
18019 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
18020 if (!result || TREE_CODE (result) != VAR_DECL)
18022 error ("no matching template for %qD found", decl);
18023 return;
18025 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
18027 error ("type %qT for explicit instantiation %qD does not match "
18028 "declared type %qT", TREE_TYPE (result), decl,
18029 TREE_TYPE (decl));
18030 return;
18033 else if (TREE_CODE (decl) != FUNCTION_DECL)
18035 error ("explicit instantiation of %q#D", decl);
18036 return;
18038 else
18039 result = decl;
18041 /* Check for various error cases. Note that if the explicit
18042 instantiation is valid the RESULT will currently be marked as an
18043 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
18044 until we get here. */
18046 if (DECL_TEMPLATE_SPECIALIZATION (result))
18048 /* DR 259 [temp.spec].
18050 Both an explicit instantiation and a declaration of an explicit
18051 specialization shall not appear in a program unless the explicit
18052 instantiation follows a declaration of the explicit specialization.
18054 For a given set of template parameters, if an explicit
18055 instantiation of a template appears after a declaration of an
18056 explicit specialization for that template, the explicit
18057 instantiation has no effect. */
18058 return;
18060 else if (DECL_EXPLICIT_INSTANTIATION (result))
18062 /* [temp.spec]
18064 No program shall explicitly instantiate any template more
18065 than once.
18067 We check DECL_NOT_REALLY_EXTERN so as not to complain when
18068 the first instantiation was `extern' and the second is not,
18069 and EXTERN_P for the opposite case. */
18070 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
18071 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
18072 /* If an "extern" explicit instantiation follows an ordinary
18073 explicit instantiation, the template is instantiated. */
18074 if (extern_p)
18075 return;
18077 else if (!DECL_IMPLICIT_INSTANTIATION (result))
18079 error ("no matching template for %qD found", result);
18080 return;
18082 else if (!DECL_TEMPLATE_INFO (result))
18084 permerror (input_location, "explicit instantiation of non-template %q#D", result);
18085 return;
18088 if (storage == NULL_TREE)
18090 else if (storage == ridpointers[(int) RID_EXTERN])
18092 if (!in_system_header && (cxx_dialect == cxx98))
18093 pedwarn (input_location, OPT_Wpedantic,
18094 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
18095 "instantiations");
18096 extern_p = 1;
18098 else
18099 error ("storage class %qD applied to template instantiation", storage);
18101 check_explicit_instantiation_namespace (result);
18102 mark_decl_instantiated (result, extern_p);
18103 if (! extern_p)
18104 instantiate_decl (result, /*defer_ok=*/1,
18105 /*expl_inst_class_mem_p=*/false);
18108 static void
18109 mark_class_instantiated (tree t, int extern_p)
18111 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
18112 SET_CLASSTYPE_INTERFACE_KNOWN (t);
18113 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
18114 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
18115 if (! extern_p)
18117 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
18118 rest_of_type_compilation (t, 1);
18122 /* Called from do_type_instantiation through binding_table_foreach to
18123 do recursive instantiation for the type bound in ENTRY. */
18124 static void
18125 bt_instantiate_type_proc (binding_entry entry, void *data)
18127 tree storage = *(tree *) data;
18129 if (MAYBE_CLASS_TYPE_P (entry->type)
18130 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
18131 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
18134 /* Called from do_type_instantiation to instantiate a member
18135 (a member function or a static member variable) of an
18136 explicitly instantiated class template. */
18137 static void
18138 instantiate_class_member (tree decl, int extern_p)
18140 mark_decl_instantiated (decl, extern_p);
18141 if (! extern_p)
18142 instantiate_decl (decl, /*defer_ok=*/1,
18143 /*expl_inst_class_mem_p=*/true);
18146 /* Perform an explicit instantiation of template class T. STORAGE, if
18147 non-null, is the RID for extern, inline or static. COMPLAIN is
18148 nonzero if this is called from the parser, zero if called recursively,
18149 since the standard is unclear (as detailed below). */
18151 void
18152 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
18154 int extern_p = 0;
18155 int nomem_p = 0;
18156 int static_p = 0;
18157 int previous_instantiation_extern_p = 0;
18159 if (TREE_CODE (t) == TYPE_DECL)
18160 t = TREE_TYPE (t);
18162 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
18164 tree tmpl =
18165 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
18166 if (tmpl)
18167 error ("explicit instantiation of non-class template %qD", tmpl);
18168 else
18169 error ("explicit instantiation of non-template type %qT", t);
18170 return;
18173 complete_type (t);
18175 if (!COMPLETE_TYPE_P (t))
18177 if (complain & tf_error)
18178 error ("explicit instantiation of %q#T before definition of template",
18180 return;
18183 if (storage != NULL_TREE)
18185 if (!in_system_header)
18187 if (storage == ridpointers[(int) RID_EXTERN])
18189 if (cxx_dialect == cxx98)
18190 pedwarn (input_location, OPT_Wpedantic,
18191 "ISO C++ 1998 forbids the use of %<extern%> on "
18192 "explicit instantiations");
18194 else
18195 pedwarn (input_location, OPT_Wpedantic,
18196 "ISO C++ forbids the use of %qE"
18197 " on explicit instantiations", storage);
18200 if (storage == ridpointers[(int) RID_INLINE])
18201 nomem_p = 1;
18202 else if (storage == ridpointers[(int) RID_EXTERN])
18203 extern_p = 1;
18204 else if (storage == ridpointers[(int) RID_STATIC])
18205 static_p = 1;
18206 else
18208 error ("storage class %qD applied to template instantiation",
18209 storage);
18210 extern_p = 0;
18214 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
18216 /* DR 259 [temp.spec].
18218 Both an explicit instantiation and a declaration of an explicit
18219 specialization shall not appear in a program unless the explicit
18220 instantiation follows a declaration of the explicit specialization.
18222 For a given set of template parameters, if an explicit
18223 instantiation of a template appears after a declaration of an
18224 explicit specialization for that template, the explicit
18225 instantiation has no effect. */
18226 return;
18228 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
18230 /* [temp.spec]
18232 No program shall explicitly instantiate any template more
18233 than once.
18235 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18236 instantiation was `extern'. If EXTERN_P then the second is.
18237 These cases are OK. */
18238 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
18240 if (!previous_instantiation_extern_p && !extern_p
18241 && (complain & tf_error))
18242 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
18244 /* If we've already instantiated the template, just return now. */
18245 if (!CLASSTYPE_INTERFACE_ONLY (t))
18246 return;
18249 check_explicit_instantiation_namespace (TYPE_NAME (t));
18250 mark_class_instantiated (t, extern_p);
18252 if (nomem_p)
18253 return;
18256 tree tmp;
18258 /* In contrast to implicit instantiation, where only the
18259 declarations, and not the definitions, of members are
18260 instantiated, we have here:
18262 [temp.explicit]
18264 The explicit instantiation of a class template specialization
18265 implies the instantiation of all of its members not
18266 previously explicitly specialized in the translation unit
18267 containing the explicit instantiation.
18269 Of course, we can't instantiate member template classes, since
18270 we don't have any arguments for them. Note that the standard
18271 is unclear on whether the instantiation of the members are
18272 *explicit* instantiations or not. However, the most natural
18273 interpretation is that it should be an explicit instantiation. */
18275 if (! static_p)
18276 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
18277 if (TREE_CODE (tmp) == FUNCTION_DECL
18278 && DECL_TEMPLATE_INSTANTIATION (tmp))
18279 instantiate_class_member (tmp, extern_p);
18281 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
18282 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
18283 instantiate_class_member (tmp, extern_p);
18285 if (CLASSTYPE_NESTED_UTDS (t))
18286 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
18287 bt_instantiate_type_proc, &storage);
18291 /* Given a function DECL, which is a specialization of TMPL, modify
18292 DECL to be a re-instantiation of TMPL with the same template
18293 arguments. TMPL should be the template into which tsubst'ing
18294 should occur for DECL, not the most general template.
18296 One reason for doing this is a scenario like this:
18298 template <class T>
18299 void f(const T&, int i);
18301 void g() { f(3, 7); }
18303 template <class T>
18304 void f(const T& t, const int i) { }
18306 Note that when the template is first instantiated, with
18307 instantiate_template, the resulting DECL will have no name for the
18308 first parameter, and the wrong type for the second. So, when we go
18309 to instantiate the DECL, we regenerate it. */
18311 static void
18312 regenerate_decl_from_template (tree decl, tree tmpl)
18314 /* The arguments used to instantiate DECL, from the most general
18315 template. */
18316 tree args;
18317 tree code_pattern;
18319 args = DECL_TI_ARGS (decl);
18320 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
18322 /* Make sure that we can see identifiers, and compute access
18323 correctly. */
18324 push_access_scope (decl);
18326 if (TREE_CODE (decl) == FUNCTION_DECL)
18328 tree decl_parm;
18329 tree pattern_parm;
18330 tree specs;
18331 int args_depth;
18332 int parms_depth;
18334 args_depth = TMPL_ARGS_DEPTH (args);
18335 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
18336 if (args_depth > parms_depth)
18337 args = get_innermost_template_args (args, parms_depth);
18339 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
18340 args, tf_error, NULL_TREE,
18341 /*defer_ok*/false);
18342 if (specs && specs != error_mark_node)
18343 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
18344 specs);
18346 /* Merge parameter declarations. */
18347 decl_parm = skip_artificial_parms_for (decl,
18348 DECL_ARGUMENTS (decl));
18349 pattern_parm
18350 = skip_artificial_parms_for (code_pattern,
18351 DECL_ARGUMENTS (code_pattern));
18352 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
18354 tree parm_type;
18355 tree attributes;
18357 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18358 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
18359 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
18360 NULL_TREE);
18361 parm_type = type_decays_to (parm_type);
18362 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18363 TREE_TYPE (decl_parm) = parm_type;
18364 attributes = DECL_ATTRIBUTES (pattern_parm);
18365 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18367 DECL_ATTRIBUTES (decl_parm) = attributes;
18368 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18370 decl_parm = DECL_CHAIN (decl_parm);
18371 pattern_parm = DECL_CHAIN (pattern_parm);
18373 /* Merge any parameters that match with the function parameter
18374 pack. */
18375 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
18377 int i, len;
18378 tree expanded_types;
18379 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18380 the parameters in this function parameter pack. */
18381 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
18382 args, tf_error, NULL_TREE);
18383 len = TREE_VEC_LENGTH (expanded_types);
18384 for (i = 0; i < len; i++)
18386 tree parm_type;
18387 tree attributes;
18389 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18390 /* Rename the parameter to include the index. */
18391 DECL_NAME (decl_parm) =
18392 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
18393 parm_type = TREE_VEC_ELT (expanded_types, i);
18394 parm_type = type_decays_to (parm_type);
18395 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18396 TREE_TYPE (decl_parm) = parm_type;
18397 attributes = DECL_ATTRIBUTES (pattern_parm);
18398 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18400 DECL_ATTRIBUTES (decl_parm) = attributes;
18401 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18403 decl_parm = DECL_CHAIN (decl_parm);
18406 /* Merge additional specifiers from the CODE_PATTERN. */
18407 if (DECL_DECLARED_INLINE_P (code_pattern)
18408 && !DECL_DECLARED_INLINE_P (decl))
18409 DECL_DECLARED_INLINE_P (decl) = 1;
18411 else if (TREE_CODE (decl) == VAR_DECL)
18413 DECL_INITIAL (decl) =
18414 tsubst_expr (DECL_INITIAL (code_pattern), args,
18415 tf_error, DECL_TI_TEMPLATE (decl),
18416 /*integral_constant_expression_p=*/false);
18417 if (VAR_HAD_UNKNOWN_BOUND (decl))
18418 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
18419 tf_error, DECL_TI_TEMPLATE (decl));
18421 else
18422 gcc_unreachable ();
18424 pop_access_scope (decl);
18427 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18428 substituted to get DECL. */
18430 tree
18431 template_for_substitution (tree decl)
18433 tree tmpl = DECL_TI_TEMPLATE (decl);
18435 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18436 for the instantiation. This is not always the most general
18437 template. Consider, for example:
18439 template <class T>
18440 struct S { template <class U> void f();
18441 template <> void f<int>(); };
18443 and an instantiation of S<double>::f<int>. We want TD to be the
18444 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18445 while (/* An instantiation cannot have a definition, so we need a
18446 more general template. */
18447 DECL_TEMPLATE_INSTANTIATION (tmpl)
18448 /* We must also deal with friend templates. Given:
18450 template <class T> struct S {
18451 template <class U> friend void f() {};
18454 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18455 so far as the language is concerned, but that's still
18456 where we get the pattern for the instantiation from. On
18457 other hand, if the definition comes outside the class, say:
18459 template <class T> struct S {
18460 template <class U> friend void f();
18462 template <class U> friend void f() {}
18464 we don't need to look any further. That's what the check for
18465 DECL_INITIAL is for. */
18466 || (TREE_CODE (decl) == FUNCTION_DECL
18467 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
18468 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
18470 /* The present template, TD, should not be a definition. If it
18471 were a definition, we should be using it! Note that we
18472 cannot restructure the loop to just keep going until we find
18473 a template with a definition, since that might go too far if
18474 a specialization was declared, but not defined. */
18475 gcc_assert (TREE_CODE (decl) != VAR_DECL
18476 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
18478 /* Fetch the more general template. */
18479 tmpl = DECL_TI_TEMPLATE (tmpl);
18482 return tmpl;
18485 /* Returns true if we need to instantiate this template instance even if we
18486 know we aren't going to emit it.. */
18488 bool
18489 always_instantiate_p (tree decl)
18491 /* We always instantiate inline functions so that we can inline them. An
18492 explicit instantiation declaration prohibits implicit instantiation of
18493 non-inline functions. With high levels of optimization, we would
18494 normally inline non-inline functions -- but we're not allowed to do
18495 that for "extern template" functions. Therefore, we check
18496 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18497 return ((TREE_CODE (decl) == FUNCTION_DECL
18498 && (DECL_DECLARED_INLINE_P (decl)
18499 || type_uses_auto (TREE_TYPE (TREE_TYPE (decl)))))
18500 /* And we need to instantiate static data members so that
18501 their initializers are available in integral constant
18502 expressions. */
18503 || (TREE_CODE (decl) == VAR_DECL
18504 && decl_maybe_constant_var_p (decl)));
18507 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18508 instantiate it now, modifying TREE_TYPE (fn). */
18510 void
18511 maybe_instantiate_noexcept (tree fn)
18513 tree fntype, spec, noex, clone;
18515 if (DECL_CLONED_FUNCTION_P (fn))
18516 fn = DECL_CLONED_FUNCTION (fn);
18517 fntype = TREE_TYPE (fn);
18518 spec = TYPE_RAISES_EXCEPTIONS (fntype);
18520 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
18521 return;
18523 noex = TREE_PURPOSE (spec);
18525 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
18527 if (push_tinst_level (fn))
18529 push_access_scope (fn);
18530 push_deferring_access_checks (dk_no_deferred);
18531 input_location = DECL_SOURCE_LOCATION (fn);
18532 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
18533 DEFERRED_NOEXCEPT_ARGS (noex),
18534 tf_warning_or_error, fn,
18535 /*function_p=*/false,
18536 /*integral_constant_expression_p=*/true);
18537 pop_deferring_access_checks ();
18538 pop_access_scope (fn);
18539 pop_tinst_level ();
18540 spec = build_noexcept_spec (noex, tf_warning_or_error);
18541 if (spec == error_mark_node)
18542 spec = noexcept_false_spec;
18544 else
18545 spec = noexcept_false_spec;
18547 else
18549 /* This is an implicitly declared function, so NOEX is a list of
18550 other functions to evaluate and merge. */
18551 tree elt;
18552 spec = noexcept_true_spec;
18553 for (elt = noex; elt; elt = OVL_NEXT (elt))
18555 tree fn = OVL_CURRENT (elt);
18556 tree subspec;
18557 maybe_instantiate_noexcept (fn);
18558 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
18559 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
18563 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
18565 FOR_EACH_CLONE (clone, fn)
18567 if (TREE_TYPE (clone) == fntype)
18568 TREE_TYPE (clone) = TREE_TYPE (fn);
18569 else
18570 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
18574 /* Produce the definition of D, a _DECL generated from a template. If
18575 DEFER_OK is nonzero, then we don't have to actually do the
18576 instantiation now; we just have to do it sometime. Normally it is
18577 an error if this is an explicit instantiation but D is undefined.
18578 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18579 explicitly instantiated class template. */
18581 tree
18582 instantiate_decl (tree d, int defer_ok,
18583 bool expl_inst_class_mem_p)
18585 tree tmpl = DECL_TI_TEMPLATE (d);
18586 tree gen_args;
18587 tree args;
18588 tree td;
18589 tree code_pattern;
18590 tree spec;
18591 tree gen_tmpl;
18592 bool pattern_defined;
18593 location_t saved_loc = input_location;
18594 bool external_p;
18595 tree fn_context;
18596 bool nested;
18598 /* This function should only be used to instantiate templates for
18599 functions and static member variables. */
18600 gcc_assert (VAR_OR_FUNCTION_DECL_P (d));
18602 /* Variables are never deferred; if instantiation is required, they
18603 are instantiated right away. That allows for better code in the
18604 case that an expression refers to the value of the variable --
18605 if the variable has a constant value the referring expression can
18606 take advantage of that fact. */
18607 if (TREE_CODE (d) == VAR_DECL
18608 || DECL_DECLARED_CONSTEXPR_P (d))
18609 defer_ok = 0;
18611 /* Don't instantiate cloned functions. Instead, instantiate the
18612 functions they cloned. */
18613 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
18614 d = DECL_CLONED_FUNCTION (d);
18616 if (DECL_TEMPLATE_INSTANTIATED (d)
18617 || (TREE_CODE (d) == FUNCTION_DECL
18618 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
18619 || DECL_TEMPLATE_SPECIALIZATION (d))
18620 /* D has already been instantiated or explicitly specialized, so
18621 there's nothing for us to do here.
18623 It might seem reasonable to check whether or not D is an explicit
18624 instantiation, and, if so, stop here. But when an explicit
18625 instantiation is deferred until the end of the compilation,
18626 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18627 the instantiation. */
18628 return d;
18630 /* Check to see whether we know that this template will be
18631 instantiated in some other file, as with "extern template"
18632 extension. */
18633 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
18635 /* In general, we do not instantiate such templates. */
18636 if (external_p && !always_instantiate_p (d))
18637 return d;
18639 gen_tmpl = most_general_template (tmpl);
18640 gen_args = DECL_TI_ARGS (d);
18642 if (tmpl != gen_tmpl)
18643 /* We should already have the extra args. */
18644 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
18645 == TMPL_ARGS_DEPTH (gen_args));
18646 /* And what's in the hash table should match D. */
18647 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
18648 || spec == NULL_TREE);
18650 /* This needs to happen before any tsubsting. */
18651 if (! push_tinst_level (d))
18652 return d;
18654 timevar_push (TV_TEMPLATE_INST);
18656 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18657 for the instantiation. */
18658 td = template_for_substitution (d);
18659 code_pattern = DECL_TEMPLATE_RESULT (td);
18661 /* We should never be trying to instantiate a member of a class
18662 template or partial specialization. */
18663 gcc_assert (d != code_pattern);
18665 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
18666 || DECL_TEMPLATE_SPECIALIZATION (td))
18667 /* In the case of a friend template whose definition is provided
18668 outside the class, we may have too many arguments. Drop the
18669 ones we don't need. The same is true for specializations. */
18670 args = get_innermost_template_args
18671 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
18672 else
18673 args = gen_args;
18675 if (TREE_CODE (d) == FUNCTION_DECL)
18676 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
18677 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
18678 else
18679 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
18681 /* We may be in the middle of deferred access check. Disable it now. */
18682 push_deferring_access_checks (dk_no_deferred);
18684 /* Unless an explicit instantiation directive has already determined
18685 the linkage of D, remember that a definition is available for
18686 this entity. */
18687 if (pattern_defined
18688 && !DECL_INTERFACE_KNOWN (d)
18689 && !DECL_NOT_REALLY_EXTERN (d))
18690 mark_definable (d);
18692 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
18693 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
18694 input_location = DECL_SOURCE_LOCATION (d);
18696 /* If D is a member of an explicitly instantiated class template,
18697 and no definition is available, treat it like an implicit
18698 instantiation. */
18699 if (!pattern_defined && expl_inst_class_mem_p
18700 && DECL_EXPLICIT_INSTANTIATION (d))
18702 /* Leave linkage flags alone on instantiations with anonymous
18703 visibility. */
18704 if (TREE_PUBLIC (d))
18706 DECL_NOT_REALLY_EXTERN (d) = 0;
18707 DECL_INTERFACE_KNOWN (d) = 0;
18709 SET_DECL_IMPLICIT_INSTANTIATION (d);
18712 if (TREE_CODE (d) == FUNCTION_DECL)
18713 maybe_instantiate_noexcept (d);
18715 /* Defer all other templates, unless we have been explicitly
18716 forbidden from doing so. */
18717 if (/* If there is no definition, we cannot instantiate the
18718 template. */
18719 ! pattern_defined
18720 /* If it's OK to postpone instantiation, do so. */
18721 || defer_ok
18722 /* If this is a static data member that will be defined
18723 elsewhere, we don't want to instantiate the entire data
18724 member, but we do want to instantiate the initializer so that
18725 we can substitute that elsewhere. */
18726 || (external_p && TREE_CODE (d) == VAR_DECL))
18728 /* The definition of the static data member is now required so
18729 we must substitute the initializer. */
18730 if (TREE_CODE (d) == VAR_DECL
18731 && !DECL_INITIAL (d)
18732 && DECL_INITIAL (code_pattern))
18734 tree ns;
18735 tree init;
18736 bool const_init = false;
18738 ns = decl_namespace_context (d);
18739 push_nested_namespace (ns);
18740 push_nested_class (DECL_CONTEXT (d));
18741 init = tsubst_expr (DECL_INITIAL (code_pattern),
18742 args,
18743 tf_warning_or_error, NULL_TREE,
18744 /*integral_constant_expression_p=*/false);
18745 /* Make sure the initializer is still constant, in case of
18746 circular dependency (template/instantiate6.C). */
18747 const_init
18748 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18749 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
18750 /*asmspec_tree=*/NULL_TREE,
18751 LOOKUP_ONLYCONVERTING);
18752 pop_nested_class ();
18753 pop_nested_namespace (ns);
18756 /* We restore the source position here because it's used by
18757 add_pending_template. */
18758 input_location = saved_loc;
18760 if (at_eof && !pattern_defined
18761 && DECL_EXPLICIT_INSTANTIATION (d)
18762 && DECL_NOT_REALLY_EXTERN (d))
18763 /* [temp.explicit]
18765 The definition of a non-exported function template, a
18766 non-exported member function template, or a non-exported
18767 member function or static data member of a class template
18768 shall be present in every translation unit in which it is
18769 explicitly instantiated. */
18770 permerror (input_location, "explicit instantiation of %qD "
18771 "but no definition available", d);
18773 /* If we're in unevaluated context, we just wanted to get the
18774 constant value; this isn't an odr use, so don't queue
18775 a full instantiation. */
18776 if (cp_unevaluated_operand != 0)
18777 goto out;
18778 /* ??? Historically, we have instantiated inline functions, even
18779 when marked as "extern template". */
18780 if (!(external_p && TREE_CODE (d) == VAR_DECL))
18781 add_pending_template (d);
18782 goto out;
18784 /* Tell the repository that D is available in this translation unit
18785 -- and see if it is supposed to be instantiated here. */
18786 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
18788 /* In a PCH file, despite the fact that the repository hasn't
18789 requested instantiation in the PCH it is still possible that
18790 an instantiation will be required in a file that includes the
18791 PCH. */
18792 if (pch_file)
18793 add_pending_template (d);
18794 /* Instantiate inline functions so that the inliner can do its
18795 job, even though we'll not be emitting a copy of this
18796 function. */
18797 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
18798 goto out;
18801 fn_context = decl_function_context (d);
18802 nested = (current_function_decl != NULL_TREE);
18803 if (!fn_context)
18804 push_to_top_level ();
18805 else if (nested)
18806 push_function_context ();
18808 /* Mark D as instantiated so that recursive calls to
18809 instantiate_decl do not try to instantiate it again. */
18810 DECL_TEMPLATE_INSTANTIATED (d) = 1;
18812 /* Regenerate the declaration in case the template has been modified
18813 by a subsequent redeclaration. */
18814 regenerate_decl_from_template (d, td);
18816 /* We already set the file and line above. Reset them now in case
18817 they changed as a result of calling regenerate_decl_from_template. */
18818 input_location = DECL_SOURCE_LOCATION (d);
18820 if (TREE_CODE (d) == VAR_DECL)
18822 tree init;
18823 bool const_init = false;
18825 /* Clear out DECL_RTL; whatever was there before may not be right
18826 since we've reset the type of the declaration. */
18827 SET_DECL_RTL (d, NULL);
18828 DECL_IN_AGGR_P (d) = 0;
18830 /* The initializer is placed in DECL_INITIAL by
18831 regenerate_decl_from_template so we don't need to
18832 push/pop_access_scope again here. Pull it out so that
18833 cp_finish_decl can process it. */
18834 init = DECL_INITIAL (d);
18835 DECL_INITIAL (d) = NULL_TREE;
18836 DECL_INITIALIZED_P (d) = 0;
18838 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18839 initializer. That function will defer actual emission until
18840 we have a chance to determine linkage. */
18841 DECL_EXTERNAL (d) = 0;
18843 /* Enter the scope of D so that access-checking works correctly. */
18844 push_nested_class (DECL_CONTEXT (d));
18845 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18846 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
18847 pop_nested_class ();
18849 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
18850 synthesize_method (d);
18851 else if (TREE_CODE (d) == FUNCTION_DECL)
18853 struct pointer_map_t *saved_local_specializations;
18854 tree subst_decl;
18855 tree tmpl_parm;
18856 tree spec_parm;
18858 /* Save away the current list, in case we are instantiating one
18859 template from within the body of another. */
18860 saved_local_specializations = local_specializations;
18862 /* Set up the list of local specializations. */
18863 local_specializations = pointer_map_create ();
18865 /* Set up context. */
18866 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
18868 /* Some typedefs referenced from within the template code need to be
18869 access checked at template instantiation time, i.e now. These
18870 types were added to the template at parsing time. Let's get those
18871 and perform the access checks then. */
18872 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (gen_tmpl),
18873 gen_args);
18875 /* Create substitution entries for the parameters. */
18876 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
18877 tmpl_parm = DECL_ARGUMENTS (subst_decl);
18878 spec_parm = DECL_ARGUMENTS (d);
18879 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
18881 register_local_specialization (spec_parm, tmpl_parm);
18882 spec_parm = skip_artificial_parms_for (d, spec_parm);
18883 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
18885 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
18887 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm))
18889 register_local_specialization (spec_parm, tmpl_parm);
18890 spec_parm = DECL_CHAIN (spec_parm);
18892 else
18894 /* Register the (value) argument pack as a specialization of
18895 TMPL_PARM, then move on. */
18896 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
18897 register_local_specialization (argpack, tmpl_parm);
18900 gcc_assert (!spec_parm);
18902 /* Substitute into the body of the function. */
18903 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
18904 tf_warning_or_error, tmpl,
18905 /*integral_constant_expression_p=*/false);
18907 /* Set the current input_location to the end of the function
18908 so that finish_function knows where we are. */
18909 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
18911 /* We don't need the local specializations any more. */
18912 pointer_map_destroy (local_specializations);
18913 local_specializations = saved_local_specializations;
18915 /* Finish the function. */
18916 d = finish_function (0);
18917 expand_or_defer_fn (d);
18920 /* We're not deferring instantiation any more. */
18921 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
18923 if (!fn_context)
18924 pop_from_top_level ();
18925 else if (nested)
18926 pop_function_context ();
18928 out:
18929 input_location = saved_loc;
18930 pop_deferring_access_checks ();
18931 pop_tinst_level ();
18933 timevar_pop (TV_TEMPLATE_INST);
18935 return d;
18938 /* Run through the list of templates that we wish we could
18939 instantiate, and instantiate any we can. RETRIES is the
18940 number of times we retry pending template instantiation. */
18942 void
18943 instantiate_pending_templates (int retries)
18945 int reconsider;
18946 location_t saved_loc = input_location;
18948 /* Instantiating templates may trigger vtable generation. This in turn
18949 may require further template instantiations. We place a limit here
18950 to avoid infinite loop. */
18951 if (pending_templates && retries >= max_tinst_depth)
18953 tree decl = pending_templates->tinst->decl;
18955 error ("template instantiation depth exceeds maximum of %d"
18956 " instantiating %q+D, possibly from virtual table generation"
18957 " (use -ftemplate-depth= to increase the maximum)",
18958 max_tinst_depth, decl);
18959 if (TREE_CODE (decl) == FUNCTION_DECL)
18960 /* Pretend that we defined it. */
18961 DECL_INITIAL (decl) = error_mark_node;
18962 return;
18967 struct pending_template **t = &pending_templates;
18968 struct pending_template *last = NULL;
18969 reconsider = 0;
18970 while (*t)
18972 tree instantiation = reopen_tinst_level ((*t)->tinst);
18973 bool complete = false;
18975 if (TYPE_P (instantiation))
18977 tree fn;
18979 if (!COMPLETE_TYPE_P (instantiation))
18981 instantiate_class_template (instantiation);
18982 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
18983 for (fn = TYPE_METHODS (instantiation);
18985 fn = TREE_CHAIN (fn))
18986 if (! DECL_ARTIFICIAL (fn))
18987 instantiate_decl (fn,
18988 /*defer_ok=*/0,
18989 /*expl_inst_class_mem_p=*/false);
18990 if (COMPLETE_TYPE_P (instantiation))
18991 reconsider = 1;
18994 complete = COMPLETE_TYPE_P (instantiation);
18996 else
18998 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
18999 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
19001 instantiation
19002 = instantiate_decl (instantiation,
19003 /*defer_ok=*/0,
19004 /*expl_inst_class_mem_p=*/false);
19005 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
19006 reconsider = 1;
19009 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
19010 || DECL_TEMPLATE_INSTANTIATED (instantiation));
19013 if (complete)
19014 /* If INSTANTIATION has been instantiated, then we don't
19015 need to consider it again in the future. */
19016 *t = (*t)->next;
19017 else
19019 last = *t;
19020 t = &(*t)->next;
19022 tinst_depth = 0;
19023 current_tinst_level = NULL;
19025 last_pending_template = last;
19027 while (reconsider);
19029 input_location = saved_loc;
19032 /* Substitute ARGVEC into T, which is a list of initializers for
19033 either base class or a non-static data member. The TREE_PURPOSEs
19034 are DECLs, and the TREE_VALUEs are the initializer values. Used by
19035 instantiate_decl. */
19037 static tree
19038 tsubst_initializer_list (tree t, tree argvec)
19040 tree inits = NULL_TREE;
19042 for (; t; t = TREE_CHAIN (t))
19044 tree decl;
19045 tree init;
19046 tree expanded_bases = NULL_TREE;
19047 tree expanded_arguments = NULL_TREE;
19048 int i, len = 1;
19050 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
19052 tree expr;
19053 tree arg;
19055 /* Expand the base class expansion type into separate base
19056 classes. */
19057 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
19058 tf_warning_or_error,
19059 NULL_TREE);
19060 if (expanded_bases == error_mark_node)
19061 continue;
19063 /* We'll be building separate TREE_LISTs of arguments for
19064 each base. */
19065 len = TREE_VEC_LENGTH (expanded_bases);
19066 expanded_arguments = make_tree_vec (len);
19067 for (i = 0; i < len; i++)
19068 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
19070 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
19071 expand each argument in the TREE_VALUE of t. */
19072 expr = make_node (EXPR_PACK_EXPANSION);
19073 PACK_EXPANSION_LOCAL_P (expr) = true;
19074 PACK_EXPANSION_PARAMETER_PACKS (expr) =
19075 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
19077 if (TREE_VALUE (t) == void_type_node)
19078 /* VOID_TYPE_NODE is used to indicate
19079 value-initialization. */
19081 for (i = 0; i < len; i++)
19082 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
19084 else
19086 /* Substitute parameter packs into each argument in the
19087 TREE_LIST. */
19088 in_base_initializer = 1;
19089 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
19091 tree expanded_exprs;
19093 /* Expand the argument. */
19094 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
19095 expanded_exprs
19096 = tsubst_pack_expansion (expr, argvec,
19097 tf_warning_or_error,
19098 NULL_TREE);
19099 if (expanded_exprs == error_mark_node)
19100 continue;
19102 /* Prepend each of the expanded expressions to the
19103 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
19104 for (i = 0; i < len; i++)
19106 TREE_VEC_ELT (expanded_arguments, i) =
19107 tree_cons (NULL_TREE,
19108 TREE_VEC_ELT (expanded_exprs, i),
19109 TREE_VEC_ELT (expanded_arguments, i));
19112 in_base_initializer = 0;
19114 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
19115 since we built them backwards. */
19116 for (i = 0; i < len; i++)
19118 TREE_VEC_ELT (expanded_arguments, i) =
19119 nreverse (TREE_VEC_ELT (expanded_arguments, i));
19124 for (i = 0; i < len; ++i)
19126 if (expanded_bases)
19128 decl = TREE_VEC_ELT (expanded_bases, i);
19129 decl = expand_member_init (decl);
19130 init = TREE_VEC_ELT (expanded_arguments, i);
19132 else
19134 tree tmp;
19135 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
19136 tf_warning_or_error, NULL_TREE);
19138 decl = expand_member_init (decl);
19139 if (decl && !DECL_P (decl))
19140 in_base_initializer = 1;
19142 init = TREE_VALUE (t);
19143 tmp = init;
19144 if (init != void_type_node)
19145 init = tsubst_expr (init, argvec,
19146 tf_warning_or_error, NULL_TREE,
19147 /*integral_constant_expression_p=*/false);
19148 if (init == NULL_TREE && tmp != NULL_TREE)
19149 /* If we had an initializer but it instantiated to nothing,
19150 value-initialize the object. This will only occur when
19151 the initializer was a pack expansion where the parameter
19152 packs used in that expansion were of length zero. */
19153 init = void_type_node;
19154 in_base_initializer = 0;
19157 if (decl)
19159 init = build_tree_list (decl, init);
19160 TREE_CHAIN (init) = inits;
19161 inits = init;
19165 return inits;
19168 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19170 static void
19171 set_current_access_from_decl (tree decl)
19173 if (TREE_PRIVATE (decl))
19174 current_access_specifier = access_private_node;
19175 else if (TREE_PROTECTED (decl))
19176 current_access_specifier = access_protected_node;
19177 else
19178 current_access_specifier = access_public_node;
19181 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19182 is the instantiation (which should have been created with
19183 start_enum) and ARGS are the template arguments to use. */
19185 static void
19186 tsubst_enum (tree tag, tree newtag, tree args)
19188 tree e;
19190 if (SCOPED_ENUM_P (newtag))
19191 begin_scope (sk_scoped_enum, newtag);
19193 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
19195 tree value;
19196 tree decl;
19198 decl = TREE_VALUE (e);
19199 /* Note that in a template enum, the TREE_VALUE is the
19200 CONST_DECL, not the corresponding INTEGER_CST. */
19201 value = tsubst_expr (DECL_INITIAL (decl),
19202 args, tf_warning_or_error, NULL_TREE,
19203 /*integral_constant_expression_p=*/true);
19205 /* Give this enumeration constant the correct access. */
19206 set_current_access_from_decl (decl);
19208 /* Actually build the enumerator itself. */
19209 build_enumerator
19210 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
19213 if (SCOPED_ENUM_P (newtag))
19214 finish_scope ();
19216 finish_enum_value_list (newtag);
19217 finish_enum (newtag);
19219 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
19220 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
19223 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19224 its type -- but without substituting the innermost set of template
19225 arguments. So, innermost set of template parameters will appear in
19226 the type. */
19228 tree
19229 get_mostly_instantiated_function_type (tree decl)
19231 tree fn_type;
19232 tree tmpl;
19233 tree targs;
19234 tree tparms;
19235 int parm_depth;
19237 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
19238 targs = DECL_TI_ARGS (decl);
19239 tparms = DECL_TEMPLATE_PARMS (tmpl);
19240 parm_depth = TMPL_PARMS_DEPTH (tparms);
19242 /* There should be as many levels of arguments as there are levels
19243 of parameters. */
19244 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
19246 fn_type = TREE_TYPE (tmpl);
19248 if (parm_depth == 1)
19249 /* No substitution is necessary. */
19251 else
19253 int i;
19254 tree partial_args;
19256 /* Replace the innermost level of the TARGS with NULL_TREEs to
19257 let tsubst know not to substitute for those parameters. */
19258 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
19259 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
19260 SET_TMPL_ARGS_LEVEL (partial_args, i,
19261 TMPL_ARGS_LEVEL (targs, i));
19262 SET_TMPL_ARGS_LEVEL (partial_args,
19263 TMPL_ARGS_DEPTH (targs),
19264 make_tree_vec (DECL_NTPARMS (tmpl)));
19266 /* Make sure that we can see identifiers, and compute access
19267 correctly. */
19268 push_access_scope (decl);
19270 ++processing_template_decl;
19271 /* Now, do the (partial) substitution to figure out the
19272 appropriate function type. */
19273 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
19274 --processing_template_decl;
19276 /* Substitute into the template parameters to obtain the real
19277 innermost set of parameters. This step is important if the
19278 innermost set of template parameters contains value
19279 parameters whose types depend on outer template parameters. */
19280 TREE_VEC_LENGTH (partial_args)--;
19281 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
19283 pop_access_scope (decl);
19286 return fn_type;
19289 /* Return truthvalue if we're processing a template different from
19290 the last one involved in diagnostics. */
19292 problematic_instantiation_changed (void)
19294 return current_tinst_level != last_error_tinst_level;
19297 /* Remember current template involved in diagnostics. */
19298 void
19299 record_last_problematic_instantiation (void)
19301 last_error_tinst_level = current_tinst_level;
19304 struct tinst_level *
19305 current_instantiation (void)
19307 return current_tinst_level;
19310 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19311 type. Return zero for ok, nonzero for disallowed. Issue error and
19312 warning messages under control of COMPLAIN. */
19314 static int
19315 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
19317 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
19318 return 0;
19319 else if (POINTER_TYPE_P (type))
19320 return 0;
19321 else if (TYPE_PTRMEM_P (type))
19322 return 0;
19323 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
19324 return 0;
19325 else if (TREE_CODE (type) == TYPENAME_TYPE)
19326 return 0;
19327 else if (TREE_CODE (type) == DECLTYPE_TYPE)
19328 return 0;
19329 else if (TREE_CODE (type) == NULLPTR_TYPE)
19330 return 0;
19332 if (complain & tf_error)
19334 if (type == error_mark_node)
19335 inform (input_location, "invalid template non-type parameter");
19336 else
19337 error ("%q#T is not a valid type for a template non-type parameter",
19338 type);
19340 return 1;
19343 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19344 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19346 static bool
19347 dependent_type_p_r (tree type)
19349 tree scope;
19351 /* [temp.dep.type]
19353 A type is dependent if it is:
19355 -- a template parameter. Template template parameters are types
19356 for us (since TYPE_P holds true for them) so we handle
19357 them here. */
19358 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19359 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
19360 return true;
19361 /* -- a qualified-id with a nested-name-specifier which contains a
19362 class-name that names a dependent type or whose unqualified-id
19363 names a dependent type. */
19364 if (TREE_CODE (type) == TYPENAME_TYPE)
19365 return true;
19366 /* -- a cv-qualified type where the cv-unqualified type is
19367 dependent. */
19368 type = TYPE_MAIN_VARIANT (type);
19369 /* -- a compound type constructed from any dependent type. */
19370 if (TYPE_PTRMEM_P (type))
19371 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
19372 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
19373 (type)));
19374 else if (TREE_CODE (type) == POINTER_TYPE
19375 || TREE_CODE (type) == REFERENCE_TYPE)
19376 return dependent_type_p (TREE_TYPE (type));
19377 else if (TREE_CODE (type) == FUNCTION_TYPE
19378 || TREE_CODE (type) == METHOD_TYPE)
19380 tree arg_type;
19382 if (dependent_type_p (TREE_TYPE (type)))
19383 return true;
19384 for (arg_type = TYPE_ARG_TYPES (type);
19385 arg_type;
19386 arg_type = TREE_CHAIN (arg_type))
19387 if (dependent_type_p (TREE_VALUE (arg_type)))
19388 return true;
19389 return false;
19391 /* -- an array type constructed from any dependent type or whose
19392 size is specified by a constant expression that is
19393 value-dependent.
19395 We checked for type- and value-dependence of the bounds in
19396 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19397 if (TREE_CODE (type) == ARRAY_TYPE)
19399 if (TYPE_DOMAIN (type)
19400 && dependent_type_p (TYPE_DOMAIN (type)))
19401 return true;
19402 return dependent_type_p (TREE_TYPE (type));
19405 /* -- a template-id in which either the template name is a template
19406 parameter ... */
19407 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
19408 return true;
19409 /* ... or any of the template arguments is a dependent type or
19410 an expression that is type-dependent or value-dependent. */
19411 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
19412 && (any_dependent_template_arguments_p
19413 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
19414 return true;
19416 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19417 dependent; if the argument of the `typeof' expression is not
19418 type-dependent, then it should already been have resolved. */
19419 if (TREE_CODE (type) == TYPEOF_TYPE
19420 || TREE_CODE (type) == DECLTYPE_TYPE
19421 || TREE_CODE (type) == UNDERLYING_TYPE)
19422 return true;
19424 /* A template argument pack is dependent if any of its packed
19425 arguments are. */
19426 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
19428 tree args = ARGUMENT_PACK_ARGS (type);
19429 int i, len = TREE_VEC_LENGTH (args);
19430 for (i = 0; i < len; ++i)
19431 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19432 return true;
19435 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19436 be template parameters. */
19437 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
19438 return true;
19440 /* The standard does not specifically mention types that are local
19441 to template functions or local classes, but they should be
19442 considered dependent too. For example:
19444 template <int I> void f() {
19445 enum E { a = I };
19446 S<sizeof (E)> s;
19449 The size of `E' cannot be known until the value of `I' has been
19450 determined. Therefore, `E' must be considered dependent. */
19451 scope = TYPE_CONTEXT (type);
19452 if (scope && TYPE_P (scope))
19453 return dependent_type_p (scope);
19454 /* Don't use type_dependent_expression_p here, as it can lead
19455 to infinite recursion trying to determine whether a lambda
19456 nested in a lambda is dependent (c++/47687). */
19457 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
19458 && DECL_LANG_SPECIFIC (scope)
19459 && DECL_TEMPLATE_INFO (scope)
19460 && (any_dependent_template_arguments_p
19461 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
19462 return true;
19464 /* Other types are non-dependent. */
19465 return false;
19468 /* Returns TRUE if TYPE is dependent, in the sense of
19469 [temp.dep.type]. Note that a NULL type is considered dependent. */
19471 bool
19472 dependent_type_p (tree type)
19474 /* If there are no template parameters in scope, then there can't be
19475 any dependent types. */
19476 if (!processing_template_decl)
19478 /* If we are not processing a template, then nobody should be
19479 providing us with a dependent type. */
19480 gcc_assert (type);
19481 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
19482 return false;
19485 /* If the type is NULL, we have not computed a type for the entity
19486 in question; in that case, the type is dependent. */
19487 if (!type)
19488 return true;
19490 /* Erroneous types can be considered non-dependent. */
19491 if (type == error_mark_node)
19492 return false;
19494 /* If we have not already computed the appropriate value for TYPE,
19495 do so now. */
19496 if (!TYPE_DEPENDENT_P_VALID (type))
19498 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
19499 TYPE_DEPENDENT_P_VALID (type) = 1;
19502 return TYPE_DEPENDENT_P (type);
19505 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19506 lookup. In other words, a dependent type that is not the current
19507 instantiation. */
19509 bool
19510 dependent_scope_p (tree scope)
19512 return (scope && TYPE_P (scope) && dependent_type_p (scope)
19513 && !currently_open_class (scope));
19516 /* T is a SCOPE_REF; return whether we need to consider it
19517 instantiation-dependent so that we can check access at instantiation
19518 time even though we know which member it resolves to. */
19520 static bool
19521 instantiation_dependent_scope_ref_p (tree t)
19523 if (DECL_P (TREE_OPERAND (t, 1))
19524 && CLASS_TYPE_P (TREE_OPERAND (t, 0))
19525 && accessible_in_template_p (TREE_OPERAND (t, 0),
19526 TREE_OPERAND (t, 1)))
19527 return false;
19528 else
19529 return true;
19532 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19533 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19534 expression. */
19536 /* Note that this predicate is not appropriate for general expressions;
19537 only constant expressions (that satisfy potential_constant_expression)
19538 can be tested for value dependence. */
19540 bool
19541 value_dependent_expression_p (tree expression)
19543 if (!processing_template_decl)
19544 return false;
19546 /* A name declared with a dependent type. */
19547 if (DECL_P (expression) && type_dependent_expression_p (expression))
19548 return true;
19550 switch (TREE_CODE (expression))
19552 case IDENTIFIER_NODE:
19553 /* A name that has not been looked up -- must be dependent. */
19554 return true;
19556 case TEMPLATE_PARM_INDEX:
19557 /* A non-type template parm. */
19558 return true;
19560 case CONST_DECL:
19561 /* A non-type template parm. */
19562 if (DECL_TEMPLATE_PARM_P (expression))
19563 return true;
19564 return value_dependent_expression_p (DECL_INITIAL (expression));
19566 case VAR_DECL:
19567 /* A constant with literal type and is initialized
19568 with an expression that is value-dependent.
19570 Note that a non-dependent parenthesized initializer will have
19571 already been replaced with its constant value, so if we see
19572 a TREE_LIST it must be dependent. */
19573 if (DECL_INITIAL (expression)
19574 && decl_constant_var_p (expression)
19575 && (TREE_CODE (DECL_INITIAL (expression)) == TREE_LIST
19576 || value_dependent_expression_p (DECL_INITIAL (expression))))
19577 return true;
19578 return false;
19580 case DYNAMIC_CAST_EXPR:
19581 case STATIC_CAST_EXPR:
19582 case CONST_CAST_EXPR:
19583 case REINTERPRET_CAST_EXPR:
19584 case CAST_EXPR:
19585 /* These expressions are value-dependent if the type to which
19586 the cast occurs is dependent or the expression being casted
19587 is value-dependent. */
19589 tree type = TREE_TYPE (expression);
19591 if (dependent_type_p (type))
19592 return true;
19594 /* A functional cast has a list of operands. */
19595 expression = TREE_OPERAND (expression, 0);
19596 if (!expression)
19598 /* If there are no operands, it must be an expression such
19599 as "int()". This should not happen for aggregate types
19600 because it would form non-constant expressions. */
19601 gcc_assert (cxx_dialect >= cxx0x
19602 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
19604 return false;
19607 if (TREE_CODE (expression) == TREE_LIST)
19608 return any_value_dependent_elements_p (expression);
19610 return value_dependent_expression_p (expression);
19613 case SIZEOF_EXPR:
19614 if (SIZEOF_EXPR_TYPE_P (expression))
19615 return dependent_type_p (TREE_TYPE (TREE_OPERAND (expression, 0)));
19616 /* FALLTHRU */
19617 case ALIGNOF_EXPR:
19618 case TYPEID_EXPR:
19619 /* A `sizeof' expression is value-dependent if the operand is
19620 type-dependent or is a pack expansion. */
19621 expression = TREE_OPERAND (expression, 0);
19622 if (PACK_EXPANSION_P (expression))
19623 return true;
19624 else if (TYPE_P (expression))
19625 return dependent_type_p (expression);
19626 return instantiation_dependent_expression_p (expression);
19628 case AT_ENCODE_EXPR:
19629 /* An 'encode' expression is value-dependent if the operand is
19630 type-dependent. */
19631 expression = TREE_OPERAND (expression, 0);
19632 return dependent_type_p (expression);
19634 case NOEXCEPT_EXPR:
19635 expression = TREE_OPERAND (expression, 0);
19636 return instantiation_dependent_expression_p (expression);
19638 case SCOPE_REF:
19639 /* All instantiation-dependent expressions should also be considered
19640 value-dependent. */
19641 return instantiation_dependent_scope_ref_p (expression);
19643 case COMPONENT_REF:
19644 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
19645 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
19647 case NONTYPE_ARGUMENT_PACK:
19648 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19649 is value-dependent. */
19651 tree values = ARGUMENT_PACK_ARGS (expression);
19652 int i, len = TREE_VEC_LENGTH (values);
19654 for (i = 0; i < len; ++i)
19655 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
19656 return true;
19658 return false;
19661 case TRAIT_EXPR:
19663 tree type2 = TRAIT_EXPR_TYPE2 (expression);
19664 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
19665 || (type2 ? dependent_type_p (type2) : false));
19668 case MODOP_EXPR:
19669 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19670 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
19672 case ARRAY_REF:
19673 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19674 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
19676 case ADDR_EXPR:
19678 tree op = TREE_OPERAND (expression, 0);
19679 return (value_dependent_expression_p (op)
19680 || has_value_dependent_address (op));
19683 case CALL_EXPR:
19685 tree fn = get_callee_fndecl (expression);
19686 int i, nargs;
19687 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
19688 return true;
19689 nargs = call_expr_nargs (expression);
19690 for (i = 0; i < nargs; ++i)
19692 tree op = CALL_EXPR_ARG (expression, i);
19693 /* In a call to a constexpr member function, look through the
19694 implicit ADDR_EXPR on the object argument so that it doesn't
19695 cause the call to be considered value-dependent. We also
19696 look through it in potential_constant_expression. */
19697 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
19698 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
19699 && TREE_CODE (op) == ADDR_EXPR)
19700 op = TREE_OPERAND (op, 0);
19701 if (value_dependent_expression_p (op))
19702 return true;
19704 return false;
19707 case TEMPLATE_ID_EXPR:
19708 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19709 type-dependent. */
19710 return type_dependent_expression_p (expression);
19712 case CONSTRUCTOR:
19714 unsigned ix;
19715 tree val;
19716 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
19717 if (value_dependent_expression_p (val))
19718 return true;
19719 return false;
19722 case STMT_EXPR:
19723 /* Treat a GNU statement expression as dependent to avoid crashing
19724 under fold_non_dependent_expr; it can't be constant. */
19725 return true;
19727 default:
19728 /* A constant expression is value-dependent if any subexpression is
19729 value-dependent. */
19730 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
19732 case tcc_reference:
19733 case tcc_unary:
19734 case tcc_comparison:
19735 case tcc_binary:
19736 case tcc_expression:
19737 case tcc_vl_exp:
19739 int i, len = cp_tree_operand_length (expression);
19741 for (i = 0; i < len; i++)
19743 tree t = TREE_OPERAND (expression, i);
19745 /* In some cases, some of the operands may be missing.l
19746 (For example, in the case of PREDECREMENT_EXPR, the
19747 amount to increment by may be missing.) That doesn't
19748 make the expression dependent. */
19749 if (t && value_dependent_expression_p (t))
19750 return true;
19753 break;
19754 default:
19755 break;
19757 break;
19760 /* The expression is not value-dependent. */
19761 return false;
19764 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19765 [temp.dep.expr]. Note that an expression with no type is
19766 considered dependent. Other parts of the compiler arrange for an
19767 expression with type-dependent subexpressions to have no type, so
19768 this function doesn't have to be fully recursive. */
19770 bool
19771 type_dependent_expression_p (tree expression)
19773 if (!processing_template_decl)
19774 return false;
19776 if (expression == error_mark_node)
19777 return false;
19779 /* An unresolved name is always dependent. */
19780 if (identifier_p (expression) || TREE_CODE (expression) == USING_DECL)
19781 return true;
19783 /* Some expression forms are never type-dependent. */
19784 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
19785 || TREE_CODE (expression) == SIZEOF_EXPR
19786 || TREE_CODE (expression) == ALIGNOF_EXPR
19787 || TREE_CODE (expression) == AT_ENCODE_EXPR
19788 || TREE_CODE (expression) == NOEXCEPT_EXPR
19789 || TREE_CODE (expression) == TRAIT_EXPR
19790 || TREE_CODE (expression) == TYPEID_EXPR
19791 || TREE_CODE (expression) == DELETE_EXPR
19792 || TREE_CODE (expression) == VEC_DELETE_EXPR
19793 || TREE_CODE (expression) == THROW_EXPR)
19794 return false;
19796 /* The types of these expressions depends only on the type to which
19797 the cast occurs. */
19798 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
19799 || TREE_CODE (expression) == STATIC_CAST_EXPR
19800 || TREE_CODE (expression) == CONST_CAST_EXPR
19801 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
19802 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
19803 || TREE_CODE (expression) == CAST_EXPR)
19804 return dependent_type_p (TREE_TYPE (expression));
19806 /* The types of these expressions depends only on the type created
19807 by the expression. */
19808 if (TREE_CODE (expression) == NEW_EXPR
19809 || TREE_CODE (expression) == VEC_NEW_EXPR)
19811 /* For NEW_EXPR tree nodes created inside a template, either
19812 the object type itself or a TREE_LIST may appear as the
19813 operand 1. */
19814 tree type = TREE_OPERAND (expression, 1);
19815 if (TREE_CODE (type) == TREE_LIST)
19816 /* This is an array type. We need to check array dimensions
19817 as well. */
19818 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
19819 || value_dependent_expression_p
19820 (TREE_OPERAND (TREE_VALUE (type), 1));
19821 else
19822 return dependent_type_p (type);
19825 if (TREE_CODE (expression) == SCOPE_REF)
19827 tree scope = TREE_OPERAND (expression, 0);
19828 tree name = TREE_OPERAND (expression, 1);
19830 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19831 contains an identifier associated by name lookup with one or more
19832 declarations declared with a dependent type, or...a
19833 nested-name-specifier or qualified-id that names a member of an
19834 unknown specialization. */
19835 return (type_dependent_expression_p (name)
19836 || dependent_scope_p (scope));
19839 if (TREE_CODE (expression) == FUNCTION_DECL
19840 && DECL_LANG_SPECIFIC (expression)
19841 && DECL_TEMPLATE_INFO (expression)
19842 && (any_dependent_template_arguments_p
19843 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
19844 return true;
19846 if (TREE_CODE (expression) == TEMPLATE_DECL
19847 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
19848 return false;
19850 if (TREE_CODE (expression) == STMT_EXPR)
19851 expression = stmt_expr_value_expr (expression);
19853 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
19855 tree elt;
19856 unsigned i;
19858 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
19860 if (type_dependent_expression_p (elt))
19861 return true;
19863 return false;
19866 /* A static data member of the current instantiation with incomplete
19867 array type is type-dependent, as the definition and specializations
19868 can have different bounds. */
19869 if (TREE_CODE (expression) == VAR_DECL
19870 && DECL_CLASS_SCOPE_P (expression)
19871 && dependent_type_p (DECL_CONTEXT (expression))
19872 && VAR_HAD_UNKNOWN_BOUND (expression))
19873 return true;
19875 if (TREE_TYPE (expression) == unknown_type_node)
19877 if (TREE_CODE (expression) == ADDR_EXPR)
19878 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
19879 if (TREE_CODE (expression) == COMPONENT_REF
19880 || TREE_CODE (expression) == OFFSET_REF)
19882 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
19883 return true;
19884 expression = TREE_OPERAND (expression, 1);
19885 if (identifier_p (expression))
19886 return false;
19888 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19889 if (TREE_CODE (expression) == SCOPE_REF)
19890 return false;
19892 if (BASELINK_P (expression))
19893 expression = BASELINK_FUNCTIONS (expression);
19895 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
19897 if (any_dependent_template_arguments_p
19898 (TREE_OPERAND (expression, 1)))
19899 return true;
19900 expression = TREE_OPERAND (expression, 0);
19902 gcc_assert (TREE_CODE (expression) == OVERLOAD
19903 || TREE_CODE (expression) == FUNCTION_DECL);
19905 while (expression)
19907 if (type_dependent_expression_p (OVL_CURRENT (expression)))
19908 return true;
19909 expression = OVL_NEXT (expression);
19911 return false;
19914 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
19916 return (dependent_type_p (TREE_TYPE (expression)));
19919 /* walk_tree callback function for instantiation_dependent_expression_p,
19920 below. Returns non-zero if a dependent subexpression is found. */
19922 static tree
19923 instantiation_dependent_r (tree *tp, int *walk_subtrees,
19924 void * /*data*/)
19926 if (TYPE_P (*tp))
19928 /* We don't have to worry about decltype currently because decltype
19929 of an instantiation-dependent expr is a dependent type. This
19930 might change depending on the resolution of DR 1172. */
19931 *walk_subtrees = false;
19932 return NULL_TREE;
19934 enum tree_code code = TREE_CODE (*tp);
19935 switch (code)
19937 /* Don't treat an argument list as dependent just because it has no
19938 TREE_TYPE. */
19939 case TREE_LIST:
19940 case TREE_VEC:
19941 return NULL_TREE;
19943 case VAR_DECL:
19944 case CONST_DECL:
19945 /* A constant with a dependent initializer is dependent. */
19946 if (value_dependent_expression_p (*tp))
19947 return *tp;
19948 break;
19950 case TEMPLATE_PARM_INDEX:
19951 return *tp;
19953 /* Handle expressions with type operands. */
19954 case SIZEOF_EXPR:
19955 case ALIGNOF_EXPR:
19956 case TYPEID_EXPR:
19957 case AT_ENCODE_EXPR:
19959 tree op = TREE_OPERAND (*tp, 0);
19960 if (code == SIZEOF_EXPR && SIZEOF_EXPR_TYPE_P (*tp))
19961 op = TREE_TYPE (op);
19962 if (TYPE_P (op))
19964 if (dependent_type_p (op))
19965 return *tp;
19966 else
19968 *walk_subtrees = false;
19969 return NULL_TREE;
19972 break;
19975 case TRAIT_EXPR:
19976 if (dependent_type_p (TRAIT_EXPR_TYPE1 (*tp))
19977 || dependent_type_p (TRAIT_EXPR_TYPE2 (*tp)))
19978 return *tp;
19979 *walk_subtrees = false;
19980 return NULL_TREE;
19982 case COMPONENT_REF:
19983 if (identifier_p (TREE_OPERAND (*tp, 1)))
19984 /* In a template, finish_class_member_access_expr creates a
19985 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
19986 type-dependent, so that we can check access control at
19987 instantiation time (PR 42277). See also Core issue 1273. */
19988 return *tp;
19989 break;
19991 case SCOPE_REF:
19992 if (instantiation_dependent_scope_ref_p (*tp))
19993 return *tp;
19994 else
19995 break;
19997 /* Treat statement-expressions as dependent. */
19998 case BIND_EXPR:
19999 return *tp;
20001 default:
20002 break;
20005 if (type_dependent_expression_p (*tp))
20006 return *tp;
20007 else
20008 return NULL_TREE;
20011 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
20012 sense defined by the ABI:
20014 "An expression is instantiation-dependent if it is type-dependent
20015 or value-dependent, or it has a subexpression that is type-dependent
20016 or value-dependent." */
20018 bool
20019 instantiation_dependent_expression_p (tree expression)
20021 tree result;
20023 if (!processing_template_decl)
20024 return false;
20026 if (expression == error_mark_node)
20027 return false;
20029 result = cp_walk_tree_without_duplicates (&expression,
20030 instantiation_dependent_r, NULL);
20031 return result != NULL_TREE;
20034 /* Like type_dependent_expression_p, but it also works while not processing
20035 a template definition, i.e. during substitution or mangling. */
20037 bool
20038 type_dependent_expression_p_push (tree expr)
20040 bool b;
20041 ++processing_template_decl;
20042 b = type_dependent_expression_p (expr);
20043 --processing_template_decl;
20044 return b;
20047 /* Returns TRUE if ARGS contains a type-dependent expression. */
20049 bool
20050 any_type_dependent_arguments_p (const vec<tree, va_gc> *args)
20052 unsigned int i;
20053 tree arg;
20055 FOR_EACH_VEC_SAFE_ELT (args, i, arg)
20057 if (type_dependent_expression_p (arg))
20058 return true;
20060 return false;
20063 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20064 expressions) contains any type-dependent expressions. */
20066 bool
20067 any_type_dependent_elements_p (const_tree list)
20069 for (; list; list = TREE_CHAIN (list))
20070 if (value_dependent_expression_p (TREE_VALUE (list)))
20071 return true;
20073 return false;
20076 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
20077 expressions) contains any value-dependent expressions. */
20079 bool
20080 any_value_dependent_elements_p (const_tree list)
20082 for (; list; list = TREE_CHAIN (list))
20083 if (value_dependent_expression_p (TREE_VALUE (list)))
20084 return true;
20086 return false;
20089 /* Returns TRUE if the ARG (a template argument) is dependent. */
20091 bool
20092 dependent_template_arg_p (tree arg)
20094 if (!processing_template_decl)
20095 return false;
20097 /* Assume a template argument that was wrongly written by the user
20098 is dependent. This is consistent with what
20099 any_dependent_template_arguments_p [that calls this function]
20100 does. */
20101 if (!arg || arg == error_mark_node)
20102 return true;
20104 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
20105 arg = ARGUMENT_PACK_SELECT_ARG (arg);
20107 if (TREE_CODE (arg) == TEMPLATE_DECL
20108 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
20109 return dependent_template_p (arg);
20110 else if (ARGUMENT_PACK_P (arg))
20112 tree args = ARGUMENT_PACK_ARGS (arg);
20113 int i, len = TREE_VEC_LENGTH (args);
20114 for (i = 0; i < len; ++i)
20116 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
20117 return true;
20120 return false;
20122 else if (TYPE_P (arg))
20123 return dependent_type_p (arg);
20124 else
20125 return (type_dependent_expression_p (arg)
20126 || value_dependent_expression_p (arg));
20129 /* Returns true if ARGS (a collection of template arguments) contains
20130 any types that require structural equality testing. */
20132 bool
20133 any_template_arguments_need_structural_equality_p (tree args)
20135 int i;
20136 int j;
20138 if (!args)
20139 return false;
20140 if (args == error_mark_node)
20141 return true;
20143 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
20145 tree level = TMPL_ARGS_LEVEL (args, i + 1);
20146 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
20148 tree arg = TREE_VEC_ELT (level, j);
20149 tree packed_args = NULL_TREE;
20150 int k, len = 1;
20152 if (ARGUMENT_PACK_P (arg))
20154 /* Look inside the argument pack. */
20155 packed_args = ARGUMENT_PACK_ARGS (arg);
20156 len = TREE_VEC_LENGTH (packed_args);
20159 for (k = 0; k < len; ++k)
20161 if (packed_args)
20162 arg = TREE_VEC_ELT (packed_args, k);
20164 if (error_operand_p (arg))
20165 return true;
20166 else if (TREE_CODE (arg) == TEMPLATE_DECL
20167 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
20168 continue;
20169 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
20170 return true;
20171 else if (!TYPE_P (arg) && TREE_TYPE (arg)
20172 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
20173 return true;
20178 return false;
20181 /* Returns true if ARGS (a collection of template arguments) contains
20182 any dependent arguments. */
20184 bool
20185 any_dependent_template_arguments_p (const_tree args)
20187 int i;
20188 int j;
20190 if (!args)
20191 return false;
20192 if (args == error_mark_node)
20193 return true;
20195 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
20197 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
20198 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
20199 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
20200 return true;
20203 return false;
20206 /* Returns TRUE if the template TMPL is dependent. */
20208 bool
20209 dependent_template_p (tree tmpl)
20211 if (TREE_CODE (tmpl) == OVERLOAD)
20213 while (tmpl)
20215 if (dependent_template_p (OVL_CURRENT (tmpl)))
20216 return true;
20217 tmpl = OVL_NEXT (tmpl);
20219 return false;
20222 /* Template template parameters are dependent. */
20223 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
20224 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
20225 return true;
20226 /* So are names that have not been looked up. */
20227 if (TREE_CODE (tmpl) == SCOPE_REF || identifier_p (tmpl))
20228 return true;
20229 /* So are member templates of dependent classes. */
20230 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
20231 return dependent_type_p (DECL_CONTEXT (tmpl));
20232 return false;
20235 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
20237 bool
20238 dependent_template_id_p (tree tmpl, tree args)
20240 return (dependent_template_p (tmpl)
20241 || any_dependent_template_arguments_p (args));
20244 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
20245 is dependent. */
20247 bool
20248 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
20250 int i;
20252 if (!processing_template_decl)
20253 return false;
20255 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
20257 tree decl = TREE_VEC_ELT (declv, i);
20258 tree init = TREE_VEC_ELT (initv, i);
20259 tree cond = TREE_VEC_ELT (condv, i);
20260 tree incr = TREE_VEC_ELT (incrv, i);
20262 if (type_dependent_expression_p (decl))
20263 return true;
20265 if (init && type_dependent_expression_p (init))
20266 return true;
20268 if (type_dependent_expression_p (cond))
20269 return true;
20271 if (COMPARISON_CLASS_P (cond)
20272 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
20273 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
20274 return true;
20276 if (TREE_CODE (incr) == MODOP_EXPR)
20278 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
20279 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
20280 return true;
20282 else if (type_dependent_expression_p (incr))
20283 return true;
20284 else if (TREE_CODE (incr) == MODIFY_EXPR)
20286 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
20287 return true;
20288 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
20290 tree t = TREE_OPERAND (incr, 1);
20291 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
20292 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
20293 return true;
20298 return false;
20301 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
20302 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
20303 no such TYPE can be found. Note that this function peers inside
20304 uninstantiated templates and therefore should be used only in
20305 extremely limited situations. ONLY_CURRENT_P restricts this
20306 peering to the currently open classes hierarchy (which is required
20307 when comparing types). */
20309 tree
20310 resolve_typename_type (tree type, bool only_current_p)
20312 tree scope;
20313 tree name;
20314 tree decl;
20315 int quals;
20316 tree pushed_scope;
20317 tree result;
20319 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
20321 scope = TYPE_CONTEXT (type);
20322 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20323 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20324 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20325 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20326 identifier of the TYPENAME_TYPE anymore.
20327 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20328 TYPENAME_TYPE instead, we avoid messing up with a possible
20329 typedef variant case. */
20330 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
20332 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20333 it first before we can figure out what NAME refers to. */
20334 if (TREE_CODE (scope) == TYPENAME_TYPE)
20336 if (TYPENAME_IS_RESOLVING_P (scope))
20337 /* Given a class template A with a dependent base with nested type C,
20338 typedef typename A::C::C C will land us here, as trying to resolve
20339 the initial A::C leads to the local C typedef, which leads back to
20340 A::C::C. So we break the recursion now. */
20341 return type;
20342 else
20343 scope = resolve_typename_type (scope, only_current_p);
20345 /* If we don't know what SCOPE refers to, then we cannot resolve the
20346 TYPENAME_TYPE. */
20347 if (TREE_CODE (scope) == TYPENAME_TYPE)
20348 return type;
20349 /* If the SCOPE is a template type parameter, we have no way of
20350 resolving the name. */
20351 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
20352 return type;
20353 /* If the SCOPE is not the current instantiation, there's no reason
20354 to look inside it. */
20355 if (only_current_p && !currently_open_class (scope))
20356 return type;
20357 /* If this is a typedef, we don't want to look inside (c++/11987). */
20358 if (typedef_variant_p (type))
20359 return type;
20360 /* If SCOPE isn't the template itself, it will not have a valid
20361 TYPE_FIELDS list. */
20362 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
20363 /* scope is either the template itself or a compatible instantiation
20364 like X<T>, so look up the name in the original template. */
20365 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
20366 else
20367 /* scope is a partial instantiation, so we can't do the lookup or we
20368 will lose the template arguments. */
20369 return type;
20370 /* Enter the SCOPE so that name lookup will be resolved as if we
20371 were in the class definition. In particular, SCOPE will no
20372 longer be considered a dependent type. */
20373 pushed_scope = push_scope (scope);
20374 /* Look up the declaration. */
20375 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true,
20376 tf_warning_or_error);
20378 result = NULL_TREE;
20380 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20381 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20382 if (!decl)
20383 /*nop*/;
20384 else if (identifier_p (TYPENAME_TYPE_FULLNAME (type))
20385 && TREE_CODE (decl) == TYPE_DECL)
20387 result = TREE_TYPE (decl);
20388 if (result == error_mark_node)
20389 result = NULL_TREE;
20391 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
20392 && DECL_CLASS_TEMPLATE_P (decl))
20394 tree tmpl;
20395 tree args;
20396 /* Obtain the template and the arguments. */
20397 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
20398 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
20399 /* Instantiate the template. */
20400 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
20401 /*entering_scope=*/0,
20402 tf_error | tf_user);
20403 if (result == error_mark_node)
20404 result = NULL_TREE;
20407 /* Leave the SCOPE. */
20408 if (pushed_scope)
20409 pop_scope (pushed_scope);
20411 /* If we failed to resolve it, return the original typename. */
20412 if (!result)
20413 return type;
20415 /* If lookup found a typename type, resolve that too. */
20416 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
20418 /* Ill-formed programs can cause infinite recursion here, so we
20419 must catch that. */
20420 TYPENAME_IS_RESOLVING_P (type) = 1;
20421 result = resolve_typename_type (result, only_current_p);
20422 TYPENAME_IS_RESOLVING_P (type) = 0;
20425 /* Qualify the resulting type. */
20426 quals = cp_type_quals (type);
20427 if (quals)
20428 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
20430 return result;
20433 /* EXPR is an expression which is not type-dependent. Return a proxy
20434 for EXPR that can be used to compute the types of larger
20435 expressions containing EXPR. */
20437 tree
20438 build_non_dependent_expr (tree expr)
20440 tree inner_expr;
20442 #ifdef ENABLE_CHECKING
20443 /* Try to get a constant value for all non-dependent expressions in
20444 order to expose bugs in *_dependent_expression_p and constexpr. */
20445 if (cxx_dialect >= cxx0x
20446 && !instantiation_dependent_expression_p (expr))
20447 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
20448 #endif
20450 /* Preserve OVERLOADs; the functions must be available to resolve
20451 types. */
20452 inner_expr = expr;
20453 if (TREE_CODE (inner_expr) == STMT_EXPR)
20454 inner_expr = stmt_expr_value_expr (inner_expr);
20455 if (TREE_CODE (inner_expr) == ADDR_EXPR)
20456 inner_expr = TREE_OPERAND (inner_expr, 0);
20457 if (TREE_CODE (inner_expr) == COMPONENT_REF)
20458 inner_expr = TREE_OPERAND (inner_expr, 1);
20459 if (is_overloaded_fn (inner_expr)
20460 || TREE_CODE (inner_expr) == OFFSET_REF)
20461 return expr;
20462 /* There is no need to return a proxy for a variable. */
20463 if (TREE_CODE (expr) == VAR_DECL)
20464 return expr;
20465 /* Preserve string constants; conversions from string constants to
20466 "char *" are allowed, even though normally a "const char *"
20467 cannot be used to initialize a "char *". */
20468 if (TREE_CODE (expr) == STRING_CST)
20469 return expr;
20470 /* Preserve arithmetic constants, as an optimization -- there is no
20471 reason to create a new node. */
20472 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
20473 return expr;
20474 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20475 There is at least one place where we want to know that a
20476 particular expression is a throw-expression: when checking a ?:
20477 expression, there are special rules if the second or third
20478 argument is a throw-expression. */
20479 if (TREE_CODE (expr) == THROW_EXPR)
20480 return expr;
20482 /* Don't wrap an initializer list, we need to be able to look inside. */
20483 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
20484 return expr;
20486 /* Don't wrap a dummy object, we need to be able to test for it. */
20487 if (is_dummy_object (expr))
20488 return expr;
20490 if (TREE_CODE (expr) == COND_EXPR)
20491 return build3 (COND_EXPR,
20492 TREE_TYPE (expr),
20493 TREE_OPERAND (expr, 0),
20494 (TREE_OPERAND (expr, 1)
20495 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
20496 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
20497 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
20498 if (TREE_CODE (expr) == COMPOUND_EXPR
20499 && !COMPOUND_EXPR_OVERLOADED (expr))
20500 return build2 (COMPOUND_EXPR,
20501 TREE_TYPE (expr),
20502 TREE_OPERAND (expr, 0),
20503 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
20505 /* If the type is unknown, it can't really be non-dependent */
20506 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
20508 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20509 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
20512 /* ARGS is a vector of expressions as arguments to a function call.
20513 Replace the arguments with equivalent non-dependent expressions.
20514 This modifies ARGS in place. */
20516 void
20517 make_args_non_dependent (vec<tree, va_gc> *args)
20519 unsigned int ix;
20520 tree arg;
20522 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
20524 tree newarg = build_non_dependent_expr (arg);
20525 if (newarg != arg)
20526 (*args)[ix] = newarg;
20530 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20531 with a level one deeper than the actual template parms. */
20533 tree
20534 make_auto (void)
20536 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
20537 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
20538 TYPE_DECL, get_identifier ("auto"), au);
20539 TYPE_STUB_DECL (au) = TYPE_NAME (au);
20540 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
20541 (0, processing_template_decl + 1, processing_template_decl + 1,
20542 TYPE_NAME (au), NULL_TREE);
20543 TYPE_CANONICAL (au) = canonical_type_parameter (au);
20544 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
20545 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
20547 return au;
20550 /* Given type ARG, return std::initializer_list<ARG>. */
20552 static tree
20553 listify (tree arg)
20555 tree std_init_list = namespace_binding
20556 (get_identifier ("initializer_list"), std_node);
20557 tree argvec;
20558 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
20560 error ("deducing from brace-enclosed initializer list requires "
20561 "#include <initializer_list>");
20562 return error_mark_node;
20564 argvec = make_tree_vec (1);
20565 TREE_VEC_ELT (argvec, 0) = arg;
20566 return lookup_template_class (std_init_list, argvec, NULL_TREE,
20567 NULL_TREE, 0, tf_warning_or_error);
20570 /* Replace auto in TYPE with std::initializer_list<auto>. */
20572 static tree
20573 listify_autos (tree type, tree auto_node)
20575 tree init_auto = listify (auto_node);
20576 tree argvec = make_tree_vec (1);
20577 TREE_VEC_ELT (argvec, 0) = init_auto;
20578 if (processing_template_decl)
20579 argvec = add_to_template_args (current_template_args (), argvec);
20580 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20583 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20584 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20586 tree
20587 do_auto_deduction (tree type, tree init, tree auto_node)
20589 tree parms, tparms, targs;
20590 tree args[1];
20591 int val;
20593 if (init == error_mark_node)
20594 return error_mark_node;
20596 if (type_dependent_expression_p (init))
20597 /* Defining a subset of type-dependent expressions that we can deduce
20598 from ahead of time isn't worth the trouble. */
20599 return type;
20601 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20602 with either a new invented type template parameter U or, if the
20603 initializer is a braced-init-list (8.5.4), with
20604 std::initializer_list<U>. */
20605 if (BRACE_ENCLOSED_INITIALIZER_P (init))
20606 type = listify_autos (type, auto_node);
20608 init = resolve_nondeduced_context (init);
20610 parms = build_tree_list (NULL_TREE, type);
20611 args[0] = init;
20612 tparms = make_tree_vec (1);
20613 targs = make_tree_vec (1);
20614 TREE_VEC_ELT (tparms, 0)
20615 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
20616 val = type_unification_real (tparms, targs, parms, args, 1, 0,
20617 DEDUCE_CALL, LOOKUP_NORMAL,
20618 /*explain_p=*/false);
20619 if (val > 0)
20621 if (processing_template_decl)
20622 /* Try again at instantiation time. */
20623 return type;
20624 if (type && type != error_mark_node)
20625 /* If type is error_mark_node a diagnostic must have been
20626 emitted by now. Also, having a mention to '<type error>'
20627 in the diagnostic is not really useful to the user. */
20629 if (cfun && auto_node == current_function_auto_return_pattern
20630 && LAMBDA_FUNCTION_P (current_function_decl))
20631 error ("unable to deduce lambda return type from %qE", init);
20632 else
20633 error ("unable to deduce %qT from %qE", type, init);
20635 return error_mark_node;
20638 /* If the list of declarators contains more than one declarator, the type
20639 of each declared variable is determined as described above. If the
20640 type deduced for the template parameter U is not the same in each
20641 deduction, the program is ill-formed. */
20642 if (TREE_TYPE (auto_node)
20643 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
20645 if (cfun && auto_node == current_function_auto_return_pattern
20646 && LAMBDA_FUNCTION_P (current_function_decl))
20647 error ("inconsistent types %qT and %qT deduced for "
20648 "lambda return type", TREE_TYPE (auto_node),
20649 TREE_VEC_ELT (targs, 0));
20650 else
20651 error ("inconsistent deduction for %qT: %qT and then %qT",
20652 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
20653 return error_mark_node;
20655 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
20657 if (processing_template_decl)
20658 targs = add_to_template_args (current_template_args (), targs);
20659 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
20662 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20663 result. */
20665 tree
20666 splice_late_return_type (tree type, tree late_return_type)
20668 tree argvec;
20670 if (late_return_type == NULL_TREE)
20671 return type;
20672 argvec = make_tree_vec (1);
20673 TREE_VEC_ELT (argvec, 0) = late_return_type;
20674 if (processing_template_parmlist)
20675 /* For a late-specified return type in a template type-parameter, we
20676 need to add a dummy argument level for its parmlist. */
20677 argvec = add_to_template_args
20678 (make_tree_vec (processing_template_parmlist), argvec);
20679 if (current_template_parms)
20680 argvec = add_to_template_args (current_template_args (), argvec);
20681 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20684 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20686 bool
20687 is_auto (const_tree type)
20689 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
20690 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
20691 return true;
20692 else
20693 return false;
20696 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20697 appear as a type-specifier for the declaration in question, we don't
20698 have to look through the whole type. */
20700 tree
20701 type_uses_auto (tree type)
20703 enum tree_code code;
20704 if (is_auto (type))
20705 return type;
20707 code = TREE_CODE (type);
20709 if (code == POINTER_TYPE || code == REFERENCE_TYPE
20710 || code == OFFSET_TYPE || code == FUNCTION_TYPE
20711 || code == METHOD_TYPE || code == ARRAY_TYPE)
20712 return type_uses_auto (TREE_TYPE (type));
20714 if (TYPE_PTRMEMFUNC_P (type))
20715 return type_uses_auto (TREE_TYPE (TREE_TYPE
20716 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
20718 return NULL_TREE;
20721 /* For a given template T, return the vector of typedefs referenced
20722 in T for which access check is needed at T instantiation time.
20723 T is either a FUNCTION_DECL or a RECORD_TYPE.
20724 Those typedefs were added to T by the function
20725 append_type_to_template_for_access_check. */
20727 vec<qualified_typedef_usage_t, va_gc> *
20728 get_types_needing_access_check (tree t)
20730 tree ti;
20731 vec<qualified_typedef_usage_t, va_gc> *result = NULL;
20733 if (!t || t == error_mark_node)
20734 return NULL;
20736 if (!(ti = get_template_info (t)))
20737 return NULL;
20739 if (CLASS_TYPE_P (t)
20740 || TREE_CODE (t) == FUNCTION_DECL)
20742 if (!TI_TEMPLATE (ti))
20743 return NULL;
20745 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
20748 return result;
20751 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20752 tied to T. That list of typedefs will be access checked at
20753 T instantiation time.
20754 T is either a FUNCTION_DECL or a RECORD_TYPE.
20755 TYPE_DECL is a TYPE_DECL node representing a typedef.
20756 SCOPE is the scope through which TYPE_DECL is accessed.
20757 LOCATION is the location of the usage point of TYPE_DECL.
20759 This function is a subroutine of
20760 append_type_to_template_for_access_check. */
20762 static void
20763 append_type_to_template_for_access_check_1 (tree t,
20764 tree type_decl,
20765 tree scope,
20766 location_t location)
20768 qualified_typedef_usage_t typedef_usage;
20769 tree ti;
20771 if (!t || t == error_mark_node)
20772 return;
20774 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
20775 || CLASS_TYPE_P (t))
20776 && type_decl
20777 && TREE_CODE (type_decl) == TYPE_DECL
20778 && scope);
20780 if (!(ti = get_template_info (t)))
20781 return;
20783 gcc_assert (TI_TEMPLATE (ti));
20785 typedef_usage.typedef_decl = type_decl;
20786 typedef_usage.context = scope;
20787 typedef_usage.locus = location;
20789 vec_safe_push (TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti), typedef_usage);
20792 /* Append TYPE_DECL to the template TEMPL.
20793 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20794 At TEMPL instanciation time, TYPE_DECL will be checked to see
20795 if it can be accessed through SCOPE.
20796 LOCATION is the location of the usage point of TYPE_DECL.
20798 e.g. consider the following code snippet:
20800 class C
20802 typedef int myint;
20805 template<class U> struct S
20807 C::myint mi; // <-- usage point of the typedef C::myint
20810 S<char> s;
20812 At S<char> instantiation time, we need to check the access of C::myint
20813 In other words, we need to check the access of the myint typedef through
20814 the C scope. For that purpose, this function will add the myint typedef
20815 and the scope C through which its being accessed to a list of typedefs
20816 tied to the template S. That list will be walked at template instantiation
20817 time and access check performed on each typedefs it contains.
20818 Note that this particular code snippet should yield an error because
20819 myint is private to C. */
20821 void
20822 append_type_to_template_for_access_check (tree templ,
20823 tree type_decl,
20824 tree scope,
20825 location_t location)
20827 qualified_typedef_usage_t *iter;
20828 unsigned i;
20830 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
20832 /* Make sure we don't append the type to the template twice. */
20833 FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (templ), i, iter)
20834 if (iter->typedef_decl == type_decl && scope == iter->context)
20835 return;
20837 append_type_to_template_for_access_check_1 (templ, type_decl,
20838 scope, location);
20841 /* Set up the hash tables for template instantiations. */
20843 void
20844 init_template_processing (void)
20846 decl_specializations = htab_create_ggc (37,
20847 hash_specialization,
20848 eq_specializations,
20849 ggc_free);
20850 type_specializations = htab_create_ggc (37,
20851 hash_specialization,
20852 eq_specializations,
20853 ggc_free);
20856 /* Print stats about the template hash tables for -fstats. */
20858 void
20859 print_template_statistics (void)
20861 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
20862 "%f collisions\n", (long) htab_size (decl_specializations),
20863 (long) htab_elements (decl_specializations),
20864 htab_collisions (decl_specializations));
20865 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
20866 "%f collisions\n", (long) htab_size (type_specializations),
20867 (long) htab_elements (type_specializations),
20868 htab_collisions (type_specializations));
20871 #include "gt-cp-pt.h"