* ggc-zone.c: Follow spelling conventions.
[official-gcc.git] / gcc / cp / pt.c
blobcd293b9fab6087574573d792705c44a3f2971e38
1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003 Free Software Foundation, Inc.
4 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
5 Rewritten by Jason Merrill (jason@cygnus.com).
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
12 any later version.
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
29 #include "config.h"
30 #include "system.h"
31 #include "coretypes.h"
32 #include "tm.h"
33 #include "obstack.h"
34 #include "tree.h"
35 #include "flags.h"
36 #include "cp-tree.h"
37 #include "tree-inline.h"
38 #include "decl.h"
39 #include "lex.h"
40 #include "output.h"
41 #include "except.h"
42 #include "toplev.h"
43 #include "rtl.h"
44 #include "timevar.h"
46 /* The type of functions taking a tree, and some additional data, and
47 returning an int. */
48 typedef int (*tree_fn_t) (tree, void*);
50 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
51 instantiations have been deferred, either because their definitions
52 were not yet available, or because we were putting off doing the work.
53 The TREE_PURPOSE of each entry is either a DECL (for a function or
54 static data member), or a TYPE (for a class) indicating what we are
55 hoping to instantiate. The TREE_VALUE is not used. */
56 static GTY(()) tree pending_templates;
57 static GTY(()) tree last_pending_template;
59 int processing_template_parmlist;
60 static int template_header_count;
62 static GTY(()) tree saved_trees;
63 static GTY(()) varray_type inline_parm_levels;
64 static size_t inline_parm_levels_used;
66 static GTY(()) tree current_tinst_level;
68 static GTY(()) tree saved_access_scope;
70 /* A map from local variable declarations in the body of the template
71 presently being instantiated to the corresponding instantiated
72 local variables. */
73 static htab_t local_specializations;
75 #define UNIFY_ALLOW_NONE 0
76 #define UNIFY_ALLOW_MORE_CV_QUAL 1
77 #define UNIFY_ALLOW_LESS_CV_QUAL 2
78 #define UNIFY_ALLOW_DERIVED 4
79 #define UNIFY_ALLOW_INTEGER 8
80 #define UNIFY_ALLOW_OUTER_LEVEL 16
81 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
82 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
83 #define UNIFY_ALLOW_MAX_CORRECTION 128
85 #define GTB_VIA_VIRTUAL 1 /* The base class we are examining is
86 virtual, or a base class of a virtual
87 base. */
88 #define GTB_IGNORE_TYPE 2 /* We don't need to try to unify the current
89 type with the desired type. */
91 static void push_access_scope (tree);
92 static void pop_access_scope (tree);
93 static int resolve_overloaded_unification (tree, tree, tree, tree,
94 unification_kind_t, int);
95 static int try_one_overload (tree, tree, tree, tree, tree,
96 unification_kind_t, int, bool);
97 static int unify (tree, tree, tree, tree, int);
98 static void add_pending_template (tree);
99 static void reopen_tinst_level (tree);
100 static tree classtype_mangled_name (tree);
101 static char* mangle_class_name_for_template (const char *, tree, tree);
102 static tree tsubst_initializer_list (tree, tree);
103 static tree get_class_bindings (tree, tree, tree);
104 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t, int);
105 static void tsubst_enum (tree, tree, tree);
106 static tree add_to_template_args (tree, tree);
107 static tree add_outermost_template_args (tree, tree);
108 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
109 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*);
110 static int type_unification_real (tree, tree, tree, tree,
111 int, unification_kind_t, int, int);
112 static void note_template_header (int);
113 static tree convert_nontype_argument (tree, tree);
114 static tree convert_template_argument (tree, tree, tree,
115 tsubst_flags_t, int, tree);
116 static tree get_bindings_overload (tree, tree, tree);
117 static int for_each_template_parm (tree, tree_fn_t, void*, htab_t);
118 static tree build_template_parm_index (int, int, int, tree, tree);
119 static int inline_needs_template_parms (tree);
120 static void push_inline_template_parms_recursive (tree, int);
121 static tree retrieve_specialization (tree, tree);
122 static tree retrieve_local_specialization (tree);
123 static tree register_specialization (tree, tree, tree);
124 static void register_local_specialization (tree, tree);
125 static tree reduce_template_parm_level (tree, tree, int);
126 static tree build_template_decl (tree, tree);
127 static int mark_template_parm (tree, void *);
128 static int template_parm_this_level_p (tree, void *);
129 static tree tsubst_friend_function (tree, tree);
130 static tree tsubst_friend_class (tree, tree);
131 static int can_complete_type_without_circularity (tree);
132 static tree get_bindings (tree, tree, tree);
133 static tree get_bindings_real (tree, tree, tree, int, int, int);
134 static int template_decl_level (tree);
135 static int check_cv_quals_for_unify (int, tree, tree);
136 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
137 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
138 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
139 static void regenerate_decl_from_template (tree, tree);
140 static tree most_specialized (tree, tree, tree);
141 static tree most_specialized_class (tree, tree);
142 static int template_class_depth_real (tree, int);
143 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
144 static tree tsubst_decl (tree, tree, tree, tsubst_flags_t);
145 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
146 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
147 static void check_specialization_scope (void);
148 static tree process_partial_specialization (tree);
149 static void set_current_access_from_decl (tree);
150 static void check_default_tmpl_args (tree, tree, int, int);
151 static tree tsubst_call_declarator_parms (tree, tree, tsubst_flags_t, tree);
152 static tree get_template_base_recursive (tree, tree, tree, tree, tree, int);
153 static tree get_template_base (tree, tree, tree, tree);
154 static int verify_class_unification (tree, tree, tree);
155 static tree try_class_unification (tree, tree, tree, tree);
156 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
157 tree, tree);
158 static tree determine_specialization (tree, tree, tree *, int);
159 static int template_args_equal (tree, tree);
160 static void tsubst_default_arguments (tree);
161 static tree for_each_template_parm_r (tree *, int *, void *);
162 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
163 static void copy_default_args_to_explicit_spec (tree);
164 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
165 static int eq_local_specializations (const void *, const void *);
166 static bool dependent_type_p_r (tree);
167 static tree tsubst (tree, tree, tsubst_flags_t, tree);
168 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree);
169 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
171 /* Make the current scope suitable for access checking when we are
172 processing T. T can be FUNCTION_DECL for instantiated function
173 template, or VAR_DECL for static member variable (need by
174 instantiate_decl). */
176 static void
177 push_access_scope (tree t)
179 my_friendly_assert (TREE_CODE (t) == FUNCTION_DECL
180 || TREE_CODE (t) == VAR_DECL,
183 if (DECL_CLASS_SCOPE_P (t))
184 push_nested_class (DECL_CONTEXT (t));
185 else
186 push_to_top_level ();
188 if (TREE_CODE (t) == FUNCTION_DECL)
190 saved_access_scope = tree_cons
191 (NULL_TREE, current_function_decl, saved_access_scope);
192 current_function_decl = t;
196 /* Restore the scope set up by push_access_scope. T is the node we
197 are processing. */
199 static void
200 pop_access_scope (tree t)
202 if (TREE_CODE (t) == FUNCTION_DECL)
204 current_function_decl = TREE_VALUE (saved_access_scope);
205 saved_access_scope = TREE_CHAIN (saved_access_scope);
208 if (DECL_CLASS_SCOPE_P (t))
209 pop_nested_class ();
210 else
211 pop_from_top_level ();
214 /* Do any processing required when DECL (a member template
215 declaration) is finished. Returns the TEMPLATE_DECL corresponding
216 to DECL, unless it is a specialization, in which case the DECL
217 itself is returned. */
219 tree
220 finish_member_template_decl (tree decl)
222 if (decl == error_mark_node)
223 return error_mark_node;
225 my_friendly_assert (DECL_P (decl), 20020812);
227 if (TREE_CODE (decl) == TYPE_DECL)
229 tree type;
231 type = TREE_TYPE (decl);
232 if (IS_AGGR_TYPE (type)
233 && CLASSTYPE_TEMPLATE_INFO (type)
234 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
236 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
237 check_member_template (tmpl);
238 return tmpl;
240 return NULL_TREE;
242 else if (TREE_CODE (decl) == FIELD_DECL)
243 error ("data member `%D' cannot be a member template", decl);
244 else if (DECL_TEMPLATE_INFO (decl))
246 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
248 check_member_template (DECL_TI_TEMPLATE (decl));
249 return DECL_TI_TEMPLATE (decl);
251 else
252 return decl;
254 else
255 error ("invalid member template declaration `%D'", decl);
257 return error_mark_node;
260 /* Returns the template nesting level of the indicated class TYPE.
262 For example, in:
263 template <class T>
264 struct A
266 template <class U>
267 struct B {};
270 A<T>::B<U> has depth two, while A<T> has depth one.
271 Both A<T>::B<int> and A<int>::B<U> have depth one, if
272 COUNT_SPECIALIZATIONS is 0 or if they are instantiations, not
273 specializations.
275 This function is guaranteed to return 0 if passed NULL_TREE so
276 that, for example, `template_class_depth (current_class_type)' is
277 always safe. */
279 static int
280 template_class_depth_real (tree type, int count_specializations)
282 int depth;
284 for (depth = 0;
285 type && TREE_CODE (type) != NAMESPACE_DECL;
286 type = (TREE_CODE (type) == FUNCTION_DECL)
287 ? CP_DECL_CONTEXT (type) : TYPE_CONTEXT (type))
289 if (TREE_CODE (type) != FUNCTION_DECL)
291 if (CLASSTYPE_TEMPLATE_INFO (type)
292 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type))
293 && ((count_specializations
294 && CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
295 || uses_template_parms (CLASSTYPE_TI_ARGS (type))))
296 ++depth;
298 else
300 if (DECL_TEMPLATE_INFO (type)
301 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (type))
302 && ((count_specializations
303 && DECL_TEMPLATE_SPECIALIZATION (type))
304 || uses_template_parms (DECL_TI_ARGS (type))))
305 ++depth;
309 return depth;
312 /* Returns the template nesting level of the indicated class TYPE.
313 Like template_class_depth_real, but instantiations do not count in
314 the depth. */
316 int
317 template_class_depth (tree type)
319 return template_class_depth_real (type, /*count_specializations=*/0);
322 /* Returns 1 if processing DECL as part of do_pending_inlines
323 needs us to push template parms. */
325 static int
326 inline_needs_template_parms (tree decl)
328 if (! DECL_TEMPLATE_INFO (decl))
329 return 0;
331 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
332 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
335 /* Subroutine of maybe_begin_member_template_processing.
336 Push the template parms in PARMS, starting from LEVELS steps into the
337 chain, and ending at the beginning, since template parms are listed
338 innermost first. */
340 static void
341 push_inline_template_parms_recursive (tree parmlist, int levels)
343 tree parms = TREE_VALUE (parmlist);
344 int i;
346 if (levels > 1)
347 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
349 ++processing_template_decl;
350 current_template_parms
351 = tree_cons (size_int (processing_template_decl),
352 parms, current_template_parms);
353 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
355 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
356 NULL);
357 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
359 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
360 my_friendly_assert (DECL_P (parm), 0);
362 switch (TREE_CODE (parm))
364 case TYPE_DECL:
365 case TEMPLATE_DECL:
366 pushdecl (parm);
367 break;
369 case PARM_DECL:
371 /* Make a CONST_DECL as is done in process_template_parm.
372 It is ugly that we recreate this here; the original
373 version built in process_template_parm is no longer
374 available. */
375 tree decl = build_decl (CONST_DECL, DECL_NAME (parm),
376 TREE_TYPE (parm));
377 DECL_ARTIFICIAL (decl) = 1;
378 TREE_CONSTANT (decl) = TREE_READONLY (decl) = 1;
379 DECL_INITIAL (decl) = DECL_INITIAL (parm);
380 SET_DECL_TEMPLATE_PARM_P (decl);
381 pushdecl (decl);
383 break;
385 default:
386 abort ();
391 /* Restore the template parameter context for a member template or
392 a friend template defined in a class definition. */
394 void
395 maybe_begin_member_template_processing (tree decl)
397 tree parms;
398 int levels = 0;
400 if (inline_needs_template_parms (decl))
402 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
403 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
405 if (DECL_TEMPLATE_SPECIALIZATION (decl))
407 --levels;
408 parms = TREE_CHAIN (parms);
411 push_inline_template_parms_recursive (parms, levels);
414 /* Remember how many levels of template parameters we pushed so that
415 we can pop them later. */
416 if (!inline_parm_levels)
417 VARRAY_INT_INIT (inline_parm_levels, 4, "inline_parm_levels");
418 if (inline_parm_levels_used == inline_parm_levels->num_elements)
419 VARRAY_GROW (inline_parm_levels, 2 * inline_parm_levels_used);
420 VARRAY_INT (inline_parm_levels, inline_parm_levels_used) = levels;
421 ++inline_parm_levels_used;
424 /* Undo the effects of begin_member_template_processing. */
426 void
427 maybe_end_member_template_processing (void)
429 int i;
431 if (!inline_parm_levels_used)
432 return;
434 --inline_parm_levels_used;
435 for (i = 0;
436 i < VARRAY_INT (inline_parm_levels, inline_parm_levels_used);
437 ++i)
439 --processing_template_decl;
440 current_template_parms = TREE_CHAIN (current_template_parms);
441 poplevel (0, 0, 0);
445 /* Returns nonzero iff T is a member template function. We must be
446 careful as in
448 template <class T> class C { void f(); }
450 Here, f is a template function, and a member, but not a member
451 template. This function does not concern itself with the origin of
452 T, only its present state. So if we have
454 template <class T> class C { template <class U> void f(U); }
456 then neither C<int>::f<char> nor C<T>::f<double> is considered
457 to be a member template. But, `template <class U> void
458 C<int>::f(U)' is considered a member template. */
461 is_member_template (tree t)
463 if (!DECL_FUNCTION_TEMPLATE_P (t))
464 /* Anything that isn't a function or a template function is
465 certainly not a member template. */
466 return 0;
468 /* A local class can't have member templates. */
469 if (decl_function_context (t))
470 return 0;
472 return (DECL_FUNCTION_MEMBER_P (DECL_TEMPLATE_RESULT (t))
473 /* If there are more levels of template parameters than
474 there are template classes surrounding the declaration,
475 then we have a member template. */
476 && (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (t)) >
477 template_class_depth (DECL_CONTEXT (t))));
480 #if 0 /* UNUSED */
481 /* Returns nonzero iff T is a member template class. See
482 is_member_template for a description of what precisely constitutes
483 a member template. */
486 is_member_template_class (tree t)
488 if (!DECL_CLASS_TEMPLATE_P (t))
489 /* Anything that isn't a class template, is certainly not a member
490 template. */
491 return 0;
493 if (!DECL_CLASS_SCOPE_P (t))
494 /* Anything whose context isn't a class type is surely not a
495 member template. */
496 return 0;
498 /* If there are more levels of template parameters than there are
499 template classes surrounding the declaration, then we have a
500 member template. */
501 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (t)) >
502 template_class_depth (DECL_CONTEXT (t)));
504 #endif
506 /* Return a new template argument vector which contains all of ARGS,
507 but has as its innermost set of arguments the EXTRA_ARGS. */
509 static tree
510 add_to_template_args (tree args, tree extra_args)
512 tree new_args;
513 int extra_depth;
514 int i;
515 int j;
517 extra_depth = TMPL_ARGS_DEPTH (extra_args);
518 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
520 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
521 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
523 for (j = 1; j <= extra_depth; ++j, ++i)
524 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
526 return new_args;
529 /* Like add_to_template_args, but only the outermost ARGS are added to
530 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
531 (EXTRA_ARGS) levels are added. This function is used to combine
532 the template arguments from a partial instantiation with the
533 template arguments used to attain the full instantiation from the
534 partial instantiation. */
536 static tree
537 add_outermost_template_args (tree args, tree extra_args)
539 tree new_args;
541 /* If there are more levels of EXTRA_ARGS than there are ARGS,
542 something very fishy is going on. */
543 my_friendly_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args),
546 /* If *all* the new arguments will be the EXTRA_ARGS, just return
547 them. */
548 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
549 return extra_args;
551 /* For the moment, we make ARGS look like it contains fewer levels. */
552 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
554 new_args = add_to_template_args (args, extra_args);
556 /* Now, we restore ARGS to its full dimensions. */
557 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
559 return new_args;
562 /* Return the N levels of innermost template arguments from the ARGS. */
564 tree
565 get_innermost_template_args (tree args, int n)
567 tree new_args;
568 int extra_levels;
569 int i;
571 my_friendly_assert (n >= 0, 20000603);
573 /* If N is 1, just return the innermost set of template arguments. */
574 if (n == 1)
575 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
577 /* If we're not removing anything, just return the arguments we were
578 given. */
579 extra_levels = TMPL_ARGS_DEPTH (args) - n;
580 my_friendly_assert (extra_levels >= 0, 20000603);
581 if (extra_levels == 0)
582 return args;
584 /* Make a new set of arguments, not containing the outer arguments. */
585 new_args = make_tree_vec (n);
586 for (i = 1; i <= n; ++i)
587 SET_TMPL_ARGS_LEVEL (new_args, i,
588 TMPL_ARGS_LEVEL (args, i + extra_levels));
590 return new_args;
593 /* We've got a template header coming up; push to a new level for storing
594 the parms. */
596 void
597 begin_template_parm_list (void)
599 /* We use a non-tag-transparent scope here, which causes pushtag to
600 put tags in this scope, rather than in the enclosing class or
601 namespace scope. This is the right thing, since we want
602 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
603 global template class, push_template_decl handles putting the
604 TEMPLATE_DECL into top-level scope. For a nested template class,
605 e.g.:
607 template <class T> struct S1 {
608 template <class T> struct S2 {};
611 pushtag contains special code to call pushdecl_with_scope on the
612 TEMPLATE_DECL for S2. */
613 begin_scope (sk_template_parms, NULL);
614 ++processing_template_decl;
615 ++processing_template_parmlist;
616 note_template_header (0);
619 /* This routine is called when a specialization is declared. If it is
620 invalid to declare a specialization here, an error is reported. */
622 static void
623 check_specialization_scope (void)
625 tree scope = current_scope ();
627 /* [temp.expl.spec]
629 An explicit specialization shall be declared in the namespace of
630 which the template is a member, or, for member templates, in the
631 namespace of which the enclosing class or enclosing class
632 template is a member. An explicit specialization of a member
633 function, member class or static data member of a class template
634 shall be declared in the namespace of which the class template
635 is a member. */
636 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
637 error ("explicit specialization in non-namespace scope `%D'",
638 scope);
640 /* [temp.expl.spec]
642 In an explicit specialization declaration for a member of a class
643 template or a member template that appears in namespace scope,
644 the member template and some of its enclosing class templates may
645 remain unspecialized, except that the declaration shall not
646 explicitly specialize a class member template if its enclosing
647 class templates are not explicitly specialized as well. */
648 if (current_template_parms)
649 error ("enclosing class templates are not explicitly specialized");
652 /* We've just seen template <>. */
654 void
655 begin_specialization (void)
657 begin_scope (sk_template_spec, NULL);
658 note_template_header (1);
659 check_specialization_scope ();
662 /* Called at then end of processing a declaration preceded by
663 template<>. */
665 void
666 end_specialization (void)
668 finish_scope ();
669 reset_specialization ();
672 /* Any template <>'s that we have seen thus far are not referring to a
673 function specialization. */
675 void
676 reset_specialization (void)
678 processing_specialization = 0;
679 template_header_count = 0;
682 /* We've just seen a template header. If SPECIALIZATION is nonzero,
683 it was of the form template <>. */
685 static void
686 note_template_header (int specialization)
688 processing_specialization = specialization;
689 template_header_count++;
692 /* We're beginning an explicit instantiation. */
694 void
695 begin_explicit_instantiation (void)
697 my_friendly_assert (!processing_explicit_instantiation, 20020913);
698 processing_explicit_instantiation = true;
702 void
703 end_explicit_instantiation (void)
705 my_friendly_assert(processing_explicit_instantiation, 20020913);
706 processing_explicit_instantiation = false;
709 /* The TYPE is being declared. If it is a template type, that means it
710 is a partial specialization. Do appropriate error-checking. */
712 void
713 maybe_process_partial_specialization (tree type)
715 /* TYPE maybe an ERROR_MARK_NODE. */
716 tree context = TYPE_P (type) ? TYPE_CONTEXT (type) : NULL_TREE;
718 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
720 /* This is for ordinary explicit specialization and partial
721 specialization of a template class such as:
723 template <> class C<int>;
727 template <class T> class C<T*>;
729 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
731 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
732 && !COMPLETE_TYPE_P (type))
734 tree tpl_ns = decl_namespace_context (CLASSTYPE_TI_TEMPLATE (type));
735 if (is_associated_namespace (current_namespace, tpl_ns))
736 /* Same or super-using namespace. */;
737 else
739 pedwarn ("specializing `%#T' in different namespace", type);
740 cp_pedwarn_at (" from definition of `%#D'",
741 CLASSTYPE_TI_TEMPLATE (type));
743 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
744 if (processing_template_decl)
745 push_template_decl (TYPE_MAIN_DECL (type));
747 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
748 error ("specialization of `%T' after instantiation", type);
750 else if (CLASS_TYPE_P (type)
751 && !CLASSTYPE_USE_TEMPLATE (type)
752 && CLASSTYPE_TEMPLATE_INFO (type)
753 && context && CLASS_TYPE_P (context)
754 && CLASSTYPE_TEMPLATE_INFO (context))
756 /* This is for an explicit specialization of member class
757 template according to [temp.expl.spec/18]:
759 template <> template <class U> class C<int>::D;
761 The context `C<int>' must be an implicit instantiation.
762 Otherwise this is just a member class template declared
763 earlier like:
765 template <> class C<int> { template <class U> class D; };
766 template <> template <class U> class C<int>::D;
768 In the first case, `C<int>::D' is a specialization of `C<T>::D'
769 while in the second case, `C<int>::D' is a primary template
770 and `C<T>::D' may not exist. */
772 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
773 && !COMPLETE_TYPE_P (type))
775 tree t;
777 if (current_namespace
778 != decl_namespace_context (CLASSTYPE_TI_TEMPLATE (type)))
780 pedwarn ("specializing `%#T' in different namespace", type);
781 cp_pedwarn_at (" from definition of `%#D'",
782 CLASSTYPE_TI_TEMPLATE (type));
785 /* Check for invalid specialization after instantiation:
787 template <> template <> class C<int>::D<int>;
788 template <> template <class U> class C<int>::D; */
790 for (t = DECL_TEMPLATE_INSTANTIATIONS
791 (most_general_template (CLASSTYPE_TI_TEMPLATE (type)));
792 t; t = TREE_CHAIN (t))
793 if (TREE_VALUE (t) != type
794 && TYPE_CONTEXT (TREE_VALUE (t)) == context)
795 error ("specialization `%T' after instantiation `%T'",
796 type, TREE_VALUE (t));
798 /* Mark TYPE as a specialization. And as a result, we only
799 have one level of template argument for the innermost
800 class template. */
801 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
802 CLASSTYPE_TI_ARGS (type)
803 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
806 else if (processing_specialization)
807 error ("explicit specialization of non-template `%T'", type);
810 /* Retrieve the specialization (in the sense of [temp.spec] - a
811 specialization is either an instantiation or an explicit
812 specialization) of TMPL for the given template ARGS. If there is
813 no such specialization, return NULL_TREE. The ARGS are a vector of
814 arguments, or a vector of vectors of arguments, in the case of
815 templates with more than one level of parameters. */
817 static tree
818 retrieve_specialization (tree tmpl, tree args)
820 tree s;
822 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 0);
824 /* There should be as many levels of arguments as there are
825 levels of parameters. */
826 my_friendly_assert (TMPL_ARGS_DEPTH (args)
827 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)),
830 for (s = DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
831 s != NULL_TREE;
832 s = TREE_CHAIN (s))
833 if (comp_template_args (TREE_PURPOSE (s), args))
834 return TREE_VALUE (s);
836 return NULL_TREE;
839 /* Like retrieve_specialization, but for local declarations. */
841 static tree
842 retrieve_local_specialization (tree tmpl)
844 tree spec = htab_find_with_hash (local_specializations, tmpl,
845 htab_hash_pointer (tmpl));
846 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
849 /* Returns nonzero iff DECL is a specialization of TMPL. */
852 is_specialization_of (tree decl, tree tmpl)
854 tree t;
856 if (TREE_CODE (decl) == FUNCTION_DECL)
858 for (t = decl;
859 t != NULL_TREE;
860 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
861 if (t == tmpl)
862 return 1;
864 else
866 my_friendly_assert (TREE_CODE (decl) == TYPE_DECL, 0);
868 for (t = TREE_TYPE (decl);
869 t != NULL_TREE;
870 t = CLASSTYPE_USE_TEMPLATE (t)
871 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
872 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
873 return 1;
876 return 0;
879 /* Returns nonzero iff DECL is a specialization of friend declaration
880 FRIEND according to [temp.friend]. */
882 bool
883 is_specialization_of_friend (tree decl, tree friend)
885 bool need_template = true;
886 int template_depth;
888 my_friendly_assert (TREE_CODE (decl) == FUNCTION_DECL, 0);
890 /* For [temp.friend/6] when FRIEND is an ordinary member function
891 of a template class, we want to check if DECL is a specialization
892 if this. */
893 if (TREE_CODE (friend) == FUNCTION_DECL
894 && DECL_TEMPLATE_INFO (friend)
895 && !DECL_USE_TEMPLATE (friend))
897 friend = DECL_TI_TEMPLATE (friend);
898 need_template = false;
901 /* There is nothing to do if this is not a template friend. */
902 if (TREE_CODE (friend) != TEMPLATE_DECL)
903 return 0;
905 if (is_specialization_of (decl, friend))
906 return 1;
908 /* [temp.friend/6]
909 A member of a class template may be declared to be a friend of a
910 non-template class. In this case, the corresponding member of
911 every specialization of the class template is a friend of the
912 class granting friendship.
914 For example, given a template friend declaration
916 template <class T> friend void A<T>::f();
918 the member function below is considered a friend
920 template <> struct A<int> {
921 void f();
924 For this type of template friend, TEMPLATE_DEPTH below will be
925 nonzero. To determine if DECL is a friend of FRIEND, we first
926 check if the enclosing class is a specialization of another. */
928 template_depth = template_class_depth (DECL_CONTEXT (friend));
929 if (template_depth
930 && DECL_CLASS_SCOPE_P (decl)
931 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
932 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend))))
934 /* Next, we check the members themselves. In order to handle
935 a few tricky cases like
937 template <class T> friend void A<T>::g(T t);
938 template <class T> template <T t> friend void A<T>::h();
940 we need to figure out what ARGS is (corresponding to `T' in above
941 examples) from DECL for later processing. */
943 tree context = DECL_CONTEXT (decl);
944 tree args = NULL_TREE;
945 int current_depth = 0;
946 while (current_depth < template_depth)
948 if (CLASSTYPE_TEMPLATE_INFO (context))
950 if (current_depth == 0)
951 args = TYPE_TI_ARGS (context);
952 else
953 args = add_to_template_args (TYPE_TI_ARGS (context), args);
954 current_depth++;
956 context = TYPE_CONTEXT (context);
959 if (TREE_CODE (decl) == FUNCTION_DECL)
961 bool is_template;
962 tree friend_type;
963 tree decl_type;
964 tree friend_args_type;
965 tree decl_args_type;
967 /* Make sure that both DECL and FRIEND are templates or
968 non-templates. */
969 is_template = DECL_TEMPLATE_INFO (decl)
970 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
971 if (need_template ^ is_template)
972 return 0;
973 else if (is_template)
975 /* If both are templates, check template paramter list. */
976 tree friend_parms
977 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend),
978 args, tf_none);
979 if (!comp_template_parms
980 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
981 friend_parms))
982 return 0;
984 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
986 else
987 decl_type = TREE_TYPE (decl);
989 friend_type = tsubst_function_type (TREE_TYPE (friend), args,
990 tf_none, NULL_TREE);
991 if (friend_type == error_mark_node)
992 return 0;
994 /* Check if return types match. */
995 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
996 return 0;
998 /* Check if function parameter types match, ignoring the
999 `this' parameter. */
1000 friend_args_type = TYPE_ARG_TYPES (friend_type);
1001 decl_args_type = TYPE_ARG_TYPES (decl_type);
1002 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend))
1003 friend_args_type = TREE_CHAIN (friend_args_type);
1004 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1005 decl_args_type = TREE_CHAIN (decl_args_type);
1006 if (compparms (decl_args_type, friend_args_type))
1007 return 1;
1010 return 0;
1013 /* Register the specialization SPEC as a specialization of TMPL with
1014 the indicated ARGS. Returns SPEC, or an equivalent prior
1015 declaration, if available. */
1017 static tree
1018 register_specialization (tree spec, tree tmpl, tree args)
1020 tree s;
1022 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 0);
1024 if (TREE_CODE (spec) == FUNCTION_DECL
1025 && uses_template_parms (DECL_TI_ARGS (spec)))
1026 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1027 register it; we want the corresponding TEMPLATE_DECL instead.
1028 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1029 the more obvious `uses_template_parms (spec)' to avoid problems
1030 with default function arguments. In particular, given
1031 something like this:
1033 template <class T> void f(T t1, T t = T())
1035 the default argument expression is not substituted for in an
1036 instantiation unless and until it is actually needed. */
1037 return spec;
1039 /* There should be as many levels of arguments as there are
1040 levels of parameters. */
1041 my_friendly_assert (TMPL_ARGS_DEPTH (args)
1042 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)),
1045 for (s = DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
1046 s != NULL_TREE;
1047 s = TREE_CHAIN (s))
1049 tree fn = TREE_VALUE (s);
1051 /* We can sometimes try to re-register a specialization that we've
1052 already got. In particular, regenerate_decl_from_template
1053 calls duplicate_decls which will update the specialization
1054 list. But, we'll still get called again here anyhow. It's
1055 more convenient to simply allow this than to try to prevent it. */
1056 if (fn == spec)
1057 return spec;
1058 else if (comp_template_args (TREE_PURPOSE (s), args))
1060 if (DECL_TEMPLATE_SPECIALIZATION (spec))
1062 if (DECL_TEMPLATE_INSTANTIATION (fn))
1064 if (TREE_USED (fn)
1065 || DECL_EXPLICIT_INSTANTIATION (fn))
1067 error ("specialization of %D after instantiation",
1068 fn);
1069 return spec;
1071 else
1073 /* This situation should occur only if the first
1074 specialization is an implicit instantiation,
1075 the second is an explicit specialization, and
1076 the implicit instantiation has not yet been
1077 used. That situation can occur if we have
1078 implicitly instantiated a member function and
1079 then specialized it later.
1081 We can also wind up here if a friend
1082 declaration that looked like an instantiation
1083 turns out to be a specialization:
1085 template <class T> void foo(T);
1086 class S { friend void foo<>(int) };
1087 template <> void foo(int);
1089 We transform the existing DECL in place so that
1090 any pointers to it become pointers to the
1091 updated declaration.
1093 If there was a definition for the template, but
1094 not for the specialization, we want this to
1095 look as if there is no definition, and vice
1096 versa. */
1097 DECL_INITIAL (fn) = NULL_TREE;
1098 duplicate_decls (spec, fn);
1100 return fn;
1103 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1105 if (!duplicate_decls (spec, fn) && DECL_INITIAL (spec))
1106 /* Dup decl failed, but this is a new
1107 definition. Set the line number so any errors
1108 match this new definition. */
1109 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1111 return fn;
1117 DECL_TEMPLATE_SPECIALIZATIONS (tmpl)
1118 = tree_cons (args, spec, DECL_TEMPLATE_SPECIALIZATIONS (tmpl));
1120 return spec;
1123 /* Unregister the specialization SPEC as a specialization of TMPL.
1124 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1125 if the SPEC was listed as a specialization of TMPL. */
1127 bool
1128 reregister_specialization (tree spec, tree tmpl, tree new_spec)
1130 tree* s;
1132 for (s = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
1133 *s != NULL_TREE;
1134 s = &TREE_CHAIN (*s))
1135 if (TREE_VALUE (*s) == spec)
1137 if (!new_spec)
1138 *s = TREE_CHAIN (*s);
1139 else
1140 TREE_VALUE (*s) = new_spec;
1141 return 1;
1144 return 0;
1147 /* Compare an entry in the local specializations hash table P1 (which
1148 is really a pointer to a TREE_LIST) with P2 (which is really a
1149 DECL). */
1151 static int
1152 eq_local_specializations (const void *p1, const void *p2)
1154 return TREE_VALUE ((tree) p1) == (tree) p2;
1157 /* Hash P1, an entry in the local specializations table. */
1159 static hashval_t
1160 hash_local_specialization (const void* p1)
1162 return htab_hash_pointer (TREE_VALUE ((tree) p1));
1165 /* Like register_specialization, but for local declarations. We are
1166 registering SPEC, an instantiation of TMPL. */
1168 static void
1169 register_local_specialization (tree spec, tree tmpl)
1171 void **slot;
1173 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1174 htab_hash_pointer (tmpl), INSERT);
1175 *slot = build_tree_list (spec, tmpl);
1178 /* Print the list of candidate FNS in an error message. */
1180 void
1181 print_candidates (tree fns)
1183 tree fn;
1185 const char *str = "candidates are:";
1187 for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
1189 tree f;
1191 for (f = TREE_VALUE (fn); f; f = OVL_NEXT (f))
1192 cp_error_at ("%s %+#D", str, OVL_CURRENT (f));
1193 str = " ";
1197 /* Returns the template (one of the functions given by TEMPLATE_ID)
1198 which can be specialized to match the indicated DECL with the
1199 explicit template args given in TEMPLATE_ID. The DECL may be
1200 NULL_TREE if none is available. In that case, the functions in
1201 TEMPLATE_ID are non-members.
1203 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1204 specialization of a member template.
1206 The template args (those explicitly specified and those deduced)
1207 are output in a newly created vector *TARGS_OUT.
1209 If it is impossible to determine the result, an error message is
1210 issued. The error_mark_node is returned to indicate failure. */
1212 static tree
1213 determine_specialization (tree template_id,
1214 tree decl,
1215 tree* targs_out,
1216 int need_member_template)
1218 tree fns;
1219 tree targs;
1220 tree explicit_targs;
1221 tree candidates = NULL_TREE;
1222 tree templates = NULL_TREE;
1224 *targs_out = NULL_TREE;
1226 if (template_id == error_mark_node)
1227 return error_mark_node;
1229 fns = TREE_OPERAND (template_id, 0);
1230 explicit_targs = TREE_OPERAND (template_id, 1);
1232 if (fns == error_mark_node)
1233 return error_mark_node;
1235 /* Check for baselinks. */
1236 if (BASELINK_P (fns))
1237 fns = BASELINK_FUNCTIONS (fns);
1239 if (!is_overloaded_fn (fns))
1241 error ("`%D' is not a function template", fns);
1242 return error_mark_node;
1245 for (; fns; fns = OVL_NEXT (fns))
1247 tree fn = OVL_CURRENT (fns);
1249 if (TREE_CODE (fn) == TEMPLATE_DECL)
1251 tree decl_arg_types;
1253 /* DECL might be a specialization of FN. */
1255 /* Adjust the type of DECL in case FN is a static member. */
1256 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1257 if (DECL_STATIC_FUNCTION_P (fn)
1258 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1259 decl_arg_types = TREE_CHAIN (decl_arg_types);
1261 /* Check that the number of function parameters matches.
1262 For example,
1263 template <class T> void f(int i = 0);
1264 template <> void f<int>();
1265 The specialization f<int> is invalid but is not caught
1266 by get_bindings below. */
1268 if (list_length (TYPE_ARG_TYPES (TREE_TYPE (fn)))
1269 != list_length (decl_arg_types))
1270 continue;
1272 /* See whether this function might be a specialization of this
1273 template. */
1274 targs = get_bindings (fn, decl, explicit_targs);
1276 if (!targs)
1277 /* We cannot deduce template arguments that when used to
1278 specialize TMPL will produce DECL. */
1279 continue;
1281 /* Save this template, and the arguments deduced. */
1282 templates = tree_cons (targs, fn, templates);
1284 else if (need_member_template)
1285 /* FN is an ordinary member function, and we need a
1286 specialization of a member template. */
1288 else if (TREE_CODE (fn) != FUNCTION_DECL)
1289 /* We can get IDENTIFIER_NODEs here in certain erroneous
1290 cases. */
1292 else if (!DECL_FUNCTION_MEMBER_P (fn))
1293 /* This is just an ordinary non-member function. Nothing can
1294 be a specialization of that. */
1296 else if (DECL_ARTIFICIAL (fn))
1297 /* Cannot specialize functions that are created implicitly. */
1299 else
1301 tree decl_arg_types;
1303 /* This is an ordinary member function. However, since
1304 we're here, we can assume it's enclosing class is a
1305 template class. For example,
1307 template <typename T> struct S { void f(); };
1308 template <> void S<int>::f() {}
1310 Here, S<int>::f is a non-template, but S<int> is a
1311 template class. If FN has the same type as DECL, we
1312 might be in business. */
1314 if (!DECL_TEMPLATE_INFO (fn))
1315 /* Its enclosing class is an explicit specialization
1316 of a template class. This is not a candidate. */
1317 continue;
1319 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1320 TREE_TYPE (TREE_TYPE (fn))))
1321 /* The return types differ. */
1322 continue;
1324 /* Adjust the type of DECL in case FN is a static member. */
1325 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1326 if (DECL_STATIC_FUNCTION_P (fn)
1327 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1328 decl_arg_types = TREE_CHAIN (decl_arg_types);
1330 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1331 decl_arg_types))
1332 /* They match! */
1333 candidates = tree_cons (NULL_TREE, fn, candidates);
1337 if (templates && TREE_CHAIN (templates))
1339 /* We have:
1341 [temp.expl.spec]
1343 It is possible for a specialization with a given function
1344 signature to be instantiated from more than one function
1345 template. In such cases, explicit specification of the
1346 template arguments must be used to uniquely identify the
1347 function template specialization being specialized.
1349 Note that here, there's no suggestion that we're supposed to
1350 determine which of the candidate templates is most
1351 specialized. However, we, also have:
1353 [temp.func.order]
1355 Partial ordering of overloaded function template
1356 declarations is used in the following contexts to select
1357 the function template to which a function template
1358 specialization refers:
1360 -- when an explicit specialization refers to a function
1361 template.
1363 So, we do use the partial ordering rules, at least for now.
1364 This extension can only serve to make invalid programs valid,
1365 so it's safe. And, there is strong anecdotal evidence that
1366 the committee intended the partial ordering rules to apply;
1367 the EDG front-end has that behavior, and John Spicer claims
1368 that the committee simply forgot to delete the wording in
1369 [temp.expl.spec]. */
1370 tree tmpl = most_specialized (templates, decl, explicit_targs);
1371 if (tmpl && tmpl != error_mark_node)
1373 targs = get_bindings (tmpl, decl, explicit_targs);
1374 templates = tree_cons (targs, tmpl, NULL_TREE);
1378 if (templates == NULL_TREE && candidates == NULL_TREE)
1380 cp_error_at ("template-id `%D' for `%+D' does not match any template declaration",
1381 template_id, decl);
1382 return error_mark_node;
1384 else if ((templates && TREE_CHAIN (templates))
1385 || (candidates && TREE_CHAIN (candidates))
1386 || (templates && candidates))
1388 cp_error_at ("ambiguous template specialization `%D' for `%+D'",
1389 template_id, decl);
1390 chainon (candidates, templates);
1391 print_candidates (candidates);
1392 return error_mark_node;
1395 /* We have one, and exactly one, match. */
1396 if (candidates)
1398 /* It was a specialization of an ordinary member function in a
1399 template class. */
1400 *targs_out = copy_node (DECL_TI_ARGS (TREE_VALUE (candidates)));
1401 return DECL_TI_TEMPLATE (TREE_VALUE (candidates));
1404 /* It was a specialization of a template. */
1405 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1406 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1408 *targs_out = copy_node (targs);
1409 SET_TMPL_ARGS_LEVEL (*targs_out,
1410 TMPL_ARGS_DEPTH (*targs_out),
1411 TREE_PURPOSE (templates));
1413 else
1414 *targs_out = TREE_PURPOSE (templates);
1415 return TREE_VALUE (templates);
1418 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1419 but with the default argument values filled in from those in the
1420 TMPL_TYPES. */
1422 static tree
1423 copy_default_args_to_explicit_spec_1 (tree spec_types,
1424 tree tmpl_types)
1426 tree new_spec_types;
1428 if (!spec_types)
1429 return NULL_TREE;
1431 if (spec_types == void_list_node)
1432 return void_list_node;
1434 /* Substitute into the rest of the list. */
1435 new_spec_types =
1436 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
1437 TREE_CHAIN (tmpl_types));
1439 /* Add the default argument for this parameter. */
1440 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
1441 TREE_VALUE (spec_types),
1442 new_spec_types);
1445 /* DECL is an explicit specialization. Replicate default arguments
1446 from the template it specializes. (That way, code like:
1448 template <class T> void f(T = 3);
1449 template <> void f(double);
1450 void g () { f (); }
1452 works, as required.) An alternative approach would be to look up
1453 the correct default arguments at the call-site, but this approach
1454 is consistent with how implicit instantiations are handled. */
1456 static void
1457 copy_default_args_to_explicit_spec (tree decl)
1459 tree tmpl;
1460 tree spec_types;
1461 tree tmpl_types;
1462 tree new_spec_types;
1463 tree old_type;
1464 tree new_type;
1465 tree t;
1466 tree object_type = NULL_TREE;
1467 tree in_charge = NULL_TREE;
1468 tree vtt = NULL_TREE;
1470 /* See if there's anything we need to do. */
1471 tmpl = DECL_TI_TEMPLATE (decl);
1472 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
1473 for (t = tmpl_types; t; t = TREE_CHAIN (t))
1474 if (TREE_PURPOSE (t))
1475 break;
1476 if (!t)
1477 return;
1479 old_type = TREE_TYPE (decl);
1480 spec_types = TYPE_ARG_TYPES (old_type);
1482 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1484 /* Remove the this pointer, but remember the object's type for
1485 CV quals. */
1486 object_type = TREE_TYPE (TREE_VALUE (spec_types));
1487 spec_types = TREE_CHAIN (spec_types);
1488 tmpl_types = TREE_CHAIN (tmpl_types);
1490 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
1492 /* DECL may contain more parameters than TMPL due to the extra
1493 in-charge parameter in constructors and destructors. */
1494 in_charge = spec_types;
1495 spec_types = TREE_CHAIN (spec_types);
1497 if (DECL_HAS_VTT_PARM_P (decl))
1499 vtt = spec_types;
1500 spec_types = TREE_CHAIN (spec_types);
1504 /* Compute the merged default arguments. */
1505 new_spec_types =
1506 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
1508 /* Compute the new FUNCTION_TYPE. */
1509 if (object_type)
1511 if (vtt)
1512 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
1513 TREE_VALUE (vtt),
1514 new_spec_types);
1516 if (in_charge)
1517 /* Put the in-charge parameter back. */
1518 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
1519 TREE_VALUE (in_charge),
1520 new_spec_types);
1522 new_type = build_method_type_directly (object_type,
1523 TREE_TYPE (old_type),
1524 new_spec_types);
1526 else
1527 new_type = build_function_type (TREE_TYPE (old_type),
1528 new_spec_types);
1529 new_type = build_type_attribute_variant (new_type,
1530 TYPE_ATTRIBUTES (old_type));
1531 new_type = build_exception_variant (new_type,
1532 TYPE_RAISES_EXCEPTIONS (old_type));
1533 TREE_TYPE (decl) = new_type;
1536 /* Check to see if the function just declared, as indicated in
1537 DECLARATOR, and in DECL, is a specialization of a function
1538 template. We may also discover that the declaration is an explicit
1539 instantiation at this point.
1541 Returns DECL, or an equivalent declaration that should be used
1542 instead if all goes well. Issues an error message if something is
1543 amiss. Returns error_mark_node if the error is not easily
1544 recoverable.
1546 FLAGS is a bitmask consisting of the following flags:
1548 2: The function has a definition.
1549 4: The function is a friend.
1551 The TEMPLATE_COUNT is the number of references to qualifying
1552 template classes that appeared in the name of the function. For
1553 example, in
1555 template <class T> struct S { void f(); };
1556 void S<int>::f();
1558 the TEMPLATE_COUNT would be 1. However, explicitly specialized
1559 classes are not counted in the TEMPLATE_COUNT, so that in
1561 template <class T> struct S {};
1562 template <> struct S<int> { void f(); }
1563 template <> void S<int>::f();
1565 the TEMPLATE_COUNT would be 0. (Note that this declaration is
1566 invalid; there should be no template <>.)
1568 If the function is a specialization, it is marked as such via
1569 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
1570 is set up correctly, and it is added to the list of specializations
1571 for that template. */
1573 tree
1574 check_explicit_specialization (tree declarator,
1575 tree decl,
1576 int template_count,
1577 int flags)
1579 int have_def = flags & 2;
1580 int is_friend = flags & 4;
1581 int specialization = 0;
1582 int explicit_instantiation = 0;
1583 int member_specialization = 0;
1584 tree ctype = DECL_CLASS_CONTEXT (decl);
1585 tree dname = DECL_NAME (decl);
1586 tmpl_spec_kind tsk;
1588 tsk = current_tmpl_spec_kind (template_count);
1590 switch (tsk)
1592 case tsk_none:
1593 if (processing_specialization)
1595 specialization = 1;
1596 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1598 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1600 if (is_friend)
1601 /* This could be something like:
1603 template <class T> void f(T);
1604 class S { friend void f<>(int); } */
1605 specialization = 1;
1606 else
1608 /* This case handles bogus declarations like template <>
1609 template <class T> void f<int>(); */
1611 error ("template-id `%D' in declaration of primary template",
1612 declarator);
1613 return decl;
1616 break;
1618 case tsk_invalid_member_spec:
1619 /* The error has already been reported in
1620 check_specialization_scope. */
1621 return error_mark_node;
1623 case tsk_invalid_expl_inst:
1624 error ("template parameter list used in explicit instantiation");
1626 /* Fall through. */
1628 case tsk_expl_inst:
1629 if (have_def)
1630 error ("definition provided for explicit instantiation");
1632 explicit_instantiation = 1;
1633 break;
1635 case tsk_excessive_parms:
1636 error ("too many template parameter lists in declaration of `%D'",
1637 decl);
1638 return error_mark_node;
1640 /* Fall through. */
1641 case tsk_expl_spec:
1642 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1643 if (ctype)
1644 member_specialization = 1;
1645 else
1646 specialization = 1;
1647 break;
1649 case tsk_insufficient_parms:
1650 if (template_header_count)
1652 error("too few template parameter lists in declaration of `%D'",
1653 decl);
1654 return decl;
1656 else if (ctype != NULL_TREE
1657 && !TYPE_BEING_DEFINED (ctype)
1658 && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype)
1659 && !is_friend)
1661 /* For backwards compatibility, we accept:
1663 template <class T> struct S { void f(); };
1664 void S<int>::f() {} // Missing template <>
1666 That used to be valid C++. */
1667 if (pedantic)
1668 pedwarn
1669 ("explicit specialization not preceded by `template <>'");
1670 specialization = 1;
1671 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1673 break;
1675 case tsk_template:
1676 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1678 /* This case handles bogus declarations like template <>
1679 template <class T> void f<int>(); */
1681 if (uses_template_parms (declarator))
1682 error ("partial specialization `%D' of function template",
1683 declarator);
1684 else
1685 error ("template-id `%D' in declaration of primary template",
1686 declarator);
1687 return decl;
1690 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
1691 /* This is a specialization of a member template, without
1692 specialization the containing class. Something like:
1694 template <class T> struct S {
1695 template <class U> void f (U);
1697 template <> template <class U> void S<int>::f(U) {}
1699 That's a specialization -- but of the entire template. */
1700 specialization = 1;
1701 break;
1703 default:
1704 abort ();
1707 if (specialization || member_specialization)
1709 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
1710 for (; t; t = TREE_CHAIN (t))
1711 if (TREE_PURPOSE (t))
1713 pedwarn
1714 ("default argument specified in explicit specialization");
1715 break;
1717 if (current_lang_name == lang_name_c)
1718 error ("template specialization with C linkage");
1721 if (specialization || member_specialization || explicit_instantiation)
1723 tree tmpl = NULL_TREE;
1724 tree targs = NULL_TREE;
1726 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
1727 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
1729 tree fns;
1731 my_friendly_assert (TREE_CODE (declarator) == IDENTIFIER_NODE, 0);
1732 if (ctype)
1733 fns = dname;
1734 else
1736 /* If there is no class context, the explicit instantiation
1737 must be at namespace scope. */
1738 my_friendly_assert (DECL_NAMESPACE_SCOPE_P (decl), 20030625);
1740 /* Find the namespace binding, using the declaration
1741 context. */
1742 fns = namespace_binding (dname, CP_DECL_CONTEXT (decl));
1745 declarator = lookup_template_function (fns, NULL_TREE);
1748 if (declarator == error_mark_node)
1749 return error_mark_node;
1751 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
1753 if (!explicit_instantiation)
1754 /* A specialization in class scope. This is invalid,
1755 but the error will already have been flagged by
1756 check_specialization_scope. */
1757 return error_mark_node;
1758 else
1760 /* It's not valid to write an explicit instantiation in
1761 class scope, e.g.:
1763 class C { template void f(); }
1765 This case is caught by the parser. However, on
1766 something like:
1768 template class C { void f(); };
1770 (which is invalid) we can get here. The error will be
1771 issued later. */
1775 return decl;
1777 else if (ctype != NULL_TREE
1778 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
1779 IDENTIFIER_NODE))
1781 /* Find the list of functions in ctype that have the same
1782 name as the declared function. */
1783 tree name = TREE_OPERAND (declarator, 0);
1784 tree fns = NULL_TREE;
1785 int idx;
1787 if (constructor_name_p (name, ctype))
1789 int is_constructor = DECL_CONSTRUCTOR_P (decl);
1791 if (is_constructor ? !TYPE_HAS_CONSTRUCTOR (ctype)
1792 : !TYPE_HAS_DESTRUCTOR (ctype))
1794 /* From [temp.expl.spec]:
1796 If such an explicit specialization for the member
1797 of a class template names an implicitly-declared
1798 special member function (clause _special_), the
1799 program is ill-formed.
1801 Similar language is found in [temp.explicit]. */
1802 error ("specialization of implicitly-declared special member function");
1803 return error_mark_node;
1806 name = is_constructor ? ctor_identifier : dtor_identifier;
1809 if (!DECL_CONV_FN_P (decl))
1811 idx = lookup_fnfields_1 (ctype, name);
1812 if (idx >= 0)
1813 fns = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (ctype), idx);
1815 else
1817 tree methods;
1819 /* For a type-conversion operator, we cannot do a
1820 name-based lookup. We might be looking for `operator
1821 int' which will be a specialization of `operator T'.
1822 So, we find *all* the conversion operators, and then
1823 select from them. */
1824 fns = NULL_TREE;
1826 methods = CLASSTYPE_METHOD_VEC (ctype);
1827 if (methods)
1828 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
1829 idx < TREE_VEC_LENGTH (methods); ++idx)
1831 tree ovl = TREE_VEC_ELT (methods, idx);
1833 if (!ovl || !DECL_CONV_FN_P (OVL_CURRENT (ovl)))
1834 /* There are no more conversion functions. */
1835 break;
1837 /* Glue all these conversion functions together
1838 with those we already have. */
1839 for (; ovl; ovl = OVL_NEXT (ovl))
1840 fns = ovl_cons (OVL_CURRENT (ovl), fns);
1844 if (fns == NULL_TREE)
1846 error ("no member function `%D' declared in `%T'",
1847 name, ctype);
1848 return error_mark_node;
1850 else
1851 TREE_OPERAND (declarator, 0) = fns;
1854 /* Figure out what exactly is being specialized at this point.
1855 Note that for an explicit instantiation, even one for a
1856 member function, we cannot tell apriori whether the
1857 instantiation is for a member template, or just a member
1858 function of a template class. Even if a member template is
1859 being instantiated, the member template arguments may be
1860 elided if they can be deduced from the rest of the
1861 declaration. */
1862 tmpl = determine_specialization (declarator, decl,
1863 &targs,
1864 member_specialization);
1866 if (!tmpl || tmpl == error_mark_node)
1867 /* We couldn't figure out what this declaration was
1868 specializing. */
1869 return error_mark_node;
1870 else
1872 tree gen_tmpl = most_general_template (tmpl);
1874 if (explicit_instantiation)
1876 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
1877 is done by do_decl_instantiation later. */
1879 int arg_depth = TMPL_ARGS_DEPTH (targs);
1880 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
1882 if (arg_depth > parm_depth)
1884 /* If TMPL is not the most general template (for
1885 example, if TMPL is a friend template that is
1886 injected into namespace scope), then there will
1887 be too many levels of TARGS. Remove some of them
1888 here. */
1889 int i;
1890 tree new_targs;
1892 new_targs = make_tree_vec (parm_depth);
1893 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
1894 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
1895 = TREE_VEC_ELT (targs, i);
1896 targs = new_targs;
1899 return instantiate_template (tmpl, targs, tf_error);
1902 /* If we thought that the DECL was a member function, but it
1903 turns out to be specializing a static member function,
1904 make DECL a static member function as well. We also have
1905 to adjust last_function_parms to avoid confusing
1906 start_function later. */
1907 if (DECL_STATIC_FUNCTION_P (tmpl)
1908 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1910 revert_static_member_fn (decl);
1911 last_function_parms = TREE_CHAIN (last_function_parms);
1914 /* If this is a specialization of a member template of a
1915 template class. In we want to return the TEMPLATE_DECL,
1916 not the specialization of it. */
1917 if (tsk == tsk_template)
1919 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
1920 DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl)) = NULL_TREE;
1921 if (have_def)
1923 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
1924 DECL_SOURCE_LOCATION (DECL_TEMPLATE_RESULT (tmpl))
1925 = DECL_SOURCE_LOCATION (decl);
1927 return tmpl;
1930 /* Set up the DECL_TEMPLATE_INFO for DECL. */
1931 DECL_TEMPLATE_INFO (decl) = tree_cons (tmpl, targs, NULL_TREE);
1933 /* Inherit default function arguments from the template
1934 DECL is specializing. */
1935 copy_default_args_to_explicit_spec (decl);
1937 /* This specialization has the same protection as the
1938 template it specializes. */
1939 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
1940 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
1942 if (is_friend && !have_def)
1943 /* This is not really a declaration of a specialization.
1944 It's just the name of an instantiation. But, it's not
1945 a request for an instantiation, either. */
1946 SET_DECL_IMPLICIT_INSTANTIATION (decl);
1947 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
1948 /* This is indeed a specialization. In case of constructors
1949 and destructors, we need in-charge and not-in-charge
1950 versions in V3 ABI. */
1951 clone_function_decl (decl, /*update_method_vec_p=*/0);
1953 /* Register this specialization so that we can find it
1954 again. */
1955 decl = register_specialization (decl, gen_tmpl, targs);
1959 return decl;
1962 /* TYPE is being declared. Verify that the use of template headers
1963 and such is reasonable. Issue error messages if not. */
1965 void
1966 maybe_check_template_type (tree type)
1968 if (template_header_count)
1970 /* We are in the scope of some `template <...>' header. */
1972 int context_depth
1973 = template_class_depth_real (TYPE_CONTEXT (type),
1974 /*count_specializations=*/1);
1976 if (template_header_count <= context_depth)
1977 /* This is OK; the template headers are for the context. We
1978 are actually too lenient here; like
1979 check_explicit_specialization we should consider the number
1980 of template types included in the actual declaration. For
1981 example,
1983 template <class T> struct S {
1984 template <class U> template <class V>
1985 struct I {};
1988 is invalid, but:
1990 template <class T> struct S {
1991 template <class U> struct I;
1994 template <class T> template <class U.
1995 struct S<T>::I {};
1997 is not. */
1999 else if (template_header_count > context_depth + 1)
2000 /* There are two many template parameter lists. */
2001 error ("too many template parameter lists in declaration of `%T'", type);
2005 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2006 parameters. These are represented in the same format used for
2007 DECL_TEMPLATE_PARMS. */
2009 int comp_template_parms (tree parms1, tree parms2)
2011 tree p1;
2012 tree p2;
2014 if (parms1 == parms2)
2015 return 1;
2017 for (p1 = parms1, p2 = parms2;
2018 p1 != NULL_TREE && p2 != NULL_TREE;
2019 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2021 tree t1 = TREE_VALUE (p1);
2022 tree t2 = TREE_VALUE (p2);
2023 int i;
2025 my_friendly_assert (TREE_CODE (t1) == TREE_VEC, 0);
2026 my_friendly_assert (TREE_CODE (t2) == TREE_VEC, 0);
2028 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2029 return 0;
2031 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2033 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2034 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2036 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2037 return 0;
2039 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM)
2040 continue;
2041 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2042 return 0;
2046 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2047 /* One set of parameters has more parameters lists than the
2048 other. */
2049 return 0;
2051 return 1;
2054 /* Complain if DECL shadows a template parameter.
2056 [temp.local]: A template-parameter shall not be redeclared within its
2057 scope (including nested scopes). */
2059 void
2060 check_template_shadow (tree decl)
2062 tree olddecl;
2064 /* If we're not in a template, we can't possibly shadow a template
2065 parameter. */
2066 if (!current_template_parms)
2067 return;
2069 /* Figure out what we're shadowing. */
2070 if (TREE_CODE (decl) == OVERLOAD)
2071 decl = OVL_CURRENT (decl);
2072 olddecl = IDENTIFIER_VALUE (DECL_NAME (decl));
2074 /* If there's no previous binding for this name, we're not shadowing
2075 anything, let alone a template parameter. */
2076 if (!olddecl)
2077 return;
2079 /* If we're not shadowing a template parameter, we're done. Note
2080 that OLDDECL might be an OVERLOAD (or perhaps even an
2081 ERROR_MARK), so we can't just blithely assume it to be a _DECL
2082 node. */
2083 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
2084 return;
2086 /* We check for decl != olddecl to avoid bogus errors for using a
2087 name inside a class. We check TPFI to avoid duplicate errors for
2088 inline member templates. */
2089 if (decl == olddecl
2090 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
2091 return;
2093 cp_error_at ("declaration of `%#D'", decl);
2094 cp_error_at (" shadows template parm `%#D'", olddecl);
2097 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
2098 ORIG_LEVEL, DECL, and TYPE. */
2100 static tree
2101 build_template_parm_index (int index,
2102 int level,
2103 int orig_level,
2104 tree decl,
2105 tree type)
2107 tree t = make_node (TEMPLATE_PARM_INDEX);
2108 TEMPLATE_PARM_IDX (t) = index;
2109 TEMPLATE_PARM_LEVEL (t) = level;
2110 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
2111 TEMPLATE_PARM_DECL (t) = decl;
2112 TREE_TYPE (t) = type;
2113 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
2114 TREE_READONLY (t) = TREE_READONLY (decl);
2116 return t;
2119 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
2120 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
2121 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
2122 new one is created. */
2124 static tree
2125 reduce_template_parm_level (tree index, tree type, int levels)
2127 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
2128 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
2129 != TEMPLATE_PARM_LEVEL (index) - levels))
2131 tree orig_decl = TEMPLATE_PARM_DECL (index);
2132 tree decl, t;
2134 decl = build_decl (TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
2135 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
2136 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
2137 DECL_ARTIFICIAL (decl) = 1;
2138 SET_DECL_TEMPLATE_PARM_P (decl);
2140 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
2141 TEMPLATE_PARM_LEVEL (index) - levels,
2142 TEMPLATE_PARM_ORIG_LEVEL (index),
2143 decl, type);
2144 TEMPLATE_PARM_DESCENDANTS (index) = t;
2146 /* Template template parameters need this. */
2147 DECL_TEMPLATE_PARMS (decl)
2148 = DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index));
2151 return TEMPLATE_PARM_DESCENDANTS (index);
2154 /* Process information from new template parameter NEXT and append it to the
2155 LIST being built. */
2157 tree
2158 process_template_parm (tree list, tree next)
2160 tree parm;
2161 tree decl = 0;
2162 tree defval;
2163 int is_type, idx;
2165 parm = next;
2166 my_friendly_assert (TREE_CODE (parm) == TREE_LIST, 259);
2167 defval = TREE_PURPOSE (parm);
2168 parm = TREE_VALUE (parm);
2169 is_type = TREE_PURPOSE (parm) == class_type_node;
2171 if (list)
2173 tree p = TREE_VALUE (tree_last (list));
2175 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
2176 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
2177 else
2178 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
2179 ++idx;
2181 else
2182 idx = 0;
2184 if (!is_type)
2186 my_friendly_assert (TREE_CODE (TREE_PURPOSE (parm)) == TREE_LIST, 260);
2187 /* is a const-param */
2188 parm = grokdeclarator (TREE_VALUE (parm), TREE_PURPOSE (parm),
2189 PARM, 0, NULL);
2190 SET_DECL_TEMPLATE_PARM_P (parm);
2192 /* [temp.param]
2194 The top-level cv-qualifiers on the template-parameter are
2195 ignored when determining its type. */
2196 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
2198 /* A template parameter is not modifiable. */
2199 TREE_READONLY (parm) = TREE_CONSTANT (parm) = 1;
2200 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
2201 TREE_TYPE (parm) = void_type_node;
2202 decl = build_decl (CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
2203 TREE_CONSTANT (decl) = TREE_READONLY (decl) = 1;
2204 DECL_INITIAL (parm) = DECL_INITIAL (decl)
2205 = build_template_parm_index (idx, processing_template_decl,
2206 processing_template_decl,
2207 decl, TREE_TYPE (parm));
2209 else
2211 tree t;
2212 parm = TREE_VALUE (parm);
2214 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
2216 t = make_aggr_type (TEMPLATE_TEMPLATE_PARM);
2217 /* This is for distinguishing between real templates and template
2218 template parameters */
2219 TREE_TYPE (parm) = t;
2220 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
2221 decl = parm;
2223 else
2225 t = make_aggr_type (TEMPLATE_TYPE_PARM);
2226 /* parm is either IDENTIFIER_NODE or NULL_TREE */
2227 decl = build_decl (TYPE_DECL, parm, t);
2230 TYPE_NAME (t) = decl;
2231 TYPE_STUB_DECL (t) = decl;
2232 parm = decl;
2233 TEMPLATE_TYPE_PARM_INDEX (t)
2234 = build_template_parm_index (idx, processing_template_decl,
2235 processing_template_decl,
2236 decl, TREE_TYPE (parm));
2238 DECL_ARTIFICIAL (decl) = 1;
2239 SET_DECL_TEMPLATE_PARM_P (decl);
2240 pushdecl (decl);
2241 parm = build_tree_list (defval, parm);
2242 return chainon (list, parm);
2245 /* The end of a template parameter list has been reached. Process the
2246 tree list into a parameter vector, converting each parameter into a more
2247 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
2248 as PARM_DECLs. */
2250 tree
2251 end_template_parm_list (tree parms)
2253 int nparms;
2254 tree parm, next;
2255 tree saved_parmlist = make_tree_vec (list_length (parms));
2257 current_template_parms
2258 = tree_cons (size_int (processing_template_decl),
2259 saved_parmlist, current_template_parms);
2261 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
2263 next = TREE_CHAIN (parm);
2264 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
2265 TREE_CHAIN (parm) = NULL_TREE;
2268 --processing_template_parmlist;
2270 return saved_parmlist;
2273 /* end_template_decl is called after a template declaration is seen. */
2275 void
2276 end_template_decl (void)
2278 reset_specialization ();
2280 if (! processing_template_decl)
2281 return;
2283 /* This matches the pushlevel in begin_template_parm_list. */
2284 finish_scope ();
2286 --processing_template_decl;
2287 current_template_parms = TREE_CHAIN (current_template_parms);
2290 /* Given a template argument vector containing the template PARMS.
2291 The innermost PARMS are given first. */
2293 tree
2294 current_template_args (void)
2296 tree header;
2297 tree args = NULL_TREE;
2298 int length = TMPL_PARMS_DEPTH (current_template_parms);
2299 int l = length;
2301 /* If there is only one level of template parameters, we do not
2302 create a TREE_VEC of TREE_VECs. Instead, we return a single
2303 TREE_VEC containing the arguments. */
2304 if (length > 1)
2305 args = make_tree_vec (length);
2307 for (header = current_template_parms; header; header = TREE_CHAIN (header))
2309 tree a = copy_node (TREE_VALUE (header));
2310 int i;
2312 TREE_TYPE (a) = NULL_TREE;
2313 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
2315 tree t = TREE_VEC_ELT (a, i);
2317 /* T will be a list if we are called from within a
2318 begin/end_template_parm_list pair, but a vector directly
2319 if within a begin/end_member_template_processing pair. */
2320 if (TREE_CODE (t) == TREE_LIST)
2322 t = TREE_VALUE (t);
2324 if (TREE_CODE (t) == TYPE_DECL
2325 || TREE_CODE (t) == TEMPLATE_DECL)
2326 t = TREE_TYPE (t);
2327 else
2328 t = DECL_INITIAL (t);
2329 TREE_VEC_ELT (a, i) = t;
2333 if (length > 1)
2334 TREE_VEC_ELT (args, --l) = a;
2335 else
2336 args = a;
2339 return args;
2342 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
2343 template PARMS. Used by push_template_decl below. */
2345 static tree
2346 build_template_decl (tree decl, tree parms)
2348 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
2349 DECL_TEMPLATE_PARMS (tmpl) = parms;
2350 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
2351 if (DECL_LANG_SPECIFIC (decl))
2353 DECL_STATIC_FUNCTION_P (tmpl) = DECL_STATIC_FUNCTION_P (decl);
2354 DECL_CONSTRUCTOR_P (tmpl) = DECL_CONSTRUCTOR_P (decl);
2355 DECL_DESTRUCTOR_P (tmpl) = DECL_DESTRUCTOR_P (decl);
2356 DECL_NONCONVERTING_P (tmpl) = DECL_NONCONVERTING_P (decl);
2357 DECL_ASSIGNMENT_OPERATOR_P (tmpl) = DECL_ASSIGNMENT_OPERATOR_P (decl);
2358 if (DECL_OVERLOADED_OPERATOR_P (decl))
2359 SET_OVERLOADED_OPERATOR_CODE (tmpl,
2360 DECL_OVERLOADED_OPERATOR_P (decl));
2363 return tmpl;
2366 struct template_parm_data
2368 /* The level of the template parameters we are currently
2369 processing. */
2370 int level;
2372 /* The index of the specialization argument we are currently
2373 processing. */
2374 int current_arg;
2376 /* An array whose size is the number of template parameters. The
2377 elements are nonzero if the parameter has been used in any one
2378 of the arguments processed so far. */
2379 int* parms;
2381 /* An array whose size is the number of template arguments. The
2382 elements are nonzero if the argument makes use of template
2383 parameters of this level. */
2384 int* arg_uses_template_parms;
2387 /* Subroutine of push_template_decl used to see if each template
2388 parameter in a partial specialization is used in the explicit
2389 argument list. If T is of the LEVEL given in DATA (which is
2390 treated as a template_parm_data*), then DATA->PARMS is marked
2391 appropriately. */
2393 static int
2394 mark_template_parm (tree t, void* data)
2396 int level;
2397 int idx;
2398 struct template_parm_data* tpd = (struct template_parm_data*) data;
2400 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
2402 level = TEMPLATE_PARM_LEVEL (t);
2403 idx = TEMPLATE_PARM_IDX (t);
2405 else
2407 level = TEMPLATE_TYPE_LEVEL (t);
2408 idx = TEMPLATE_TYPE_IDX (t);
2411 if (level == tpd->level)
2413 tpd->parms[idx] = 1;
2414 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
2417 /* Return zero so that for_each_template_parm will continue the
2418 traversal of the tree; we want to mark *every* template parm. */
2419 return 0;
2422 /* Process the partial specialization DECL. */
2424 static tree
2425 process_partial_specialization (tree decl)
2427 tree type = TREE_TYPE (decl);
2428 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
2429 tree specargs = CLASSTYPE_TI_ARGS (type);
2430 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
2431 tree inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
2432 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
2433 int nargs = TREE_VEC_LENGTH (inner_args);
2434 int ntparms = TREE_VEC_LENGTH (inner_parms);
2435 int i;
2436 int did_error_intro = 0;
2437 struct template_parm_data tpd;
2438 struct template_parm_data tpd2;
2440 /* We check that each of the template parameters given in the
2441 partial specialization is used in the argument list to the
2442 specialization. For example:
2444 template <class T> struct S;
2445 template <class T> struct S<T*>;
2447 The second declaration is OK because `T*' uses the template
2448 parameter T, whereas
2450 template <class T> struct S<int>;
2452 is no good. Even trickier is:
2454 template <class T>
2455 struct S1
2457 template <class U>
2458 struct S2;
2459 template <class U>
2460 struct S2<T>;
2463 The S2<T> declaration is actually invalid; it is a
2464 full-specialization. Of course,
2466 template <class U>
2467 struct S2<T (*)(U)>;
2469 or some such would have been OK. */
2470 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
2471 tpd.parms = alloca (sizeof (int) * ntparms);
2472 memset (tpd.parms, 0, sizeof (int) * ntparms);
2474 tpd.arg_uses_template_parms = alloca (sizeof (int) * nargs);
2475 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
2476 for (i = 0; i < nargs; ++i)
2478 tpd.current_arg = i;
2479 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
2480 &mark_template_parm,
2481 &tpd,
2482 NULL);
2484 for (i = 0; i < ntparms; ++i)
2485 if (tpd.parms[i] == 0)
2487 /* One of the template parms was not used in the
2488 specialization. */
2489 if (!did_error_intro)
2491 error ("template parameters not used in partial specialization:");
2492 did_error_intro = 1;
2495 error (" `%D'",
2496 TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
2499 /* [temp.class.spec]
2501 The argument list of the specialization shall not be identical to
2502 the implicit argument list of the primary template. */
2503 if (comp_template_args
2504 (inner_args,
2505 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
2506 (maintmpl)))))
2507 error ("partial specialization `%T' does not specialize any template arguments", type);
2509 /* [temp.class.spec]
2511 A partially specialized non-type argument expression shall not
2512 involve template parameters of the partial specialization except
2513 when the argument expression is a simple identifier.
2515 The type of a template parameter corresponding to a specialized
2516 non-type argument shall not be dependent on a parameter of the
2517 specialization. */
2518 my_friendly_assert (nargs == DECL_NTPARMS (maintmpl), 0);
2519 tpd2.parms = 0;
2520 for (i = 0; i < nargs; ++i)
2522 tree arg = TREE_VEC_ELT (inner_args, i);
2523 if (/* These first two lines are the `non-type' bit. */
2524 !TYPE_P (arg)
2525 && TREE_CODE (arg) != TEMPLATE_DECL
2526 /* This next line is the `argument expression is not just a
2527 simple identifier' condition and also the `specialized
2528 non-type argument' bit. */
2529 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
2531 if (tpd.arg_uses_template_parms[i])
2532 error ("template argument `%E' involves template parameter(s)", arg);
2533 else
2535 /* Look at the corresponding template parameter,
2536 marking which template parameters its type depends
2537 upon. */
2538 tree type =
2539 TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (main_inner_parms,
2540 i)));
2542 if (!tpd2.parms)
2544 /* We haven't yet initialized TPD2. Do so now. */
2545 tpd2.arg_uses_template_parms
2546 = alloca (sizeof (int) * nargs);
2547 /* The number of parameters here is the number in the
2548 main template, which, as checked in the assertion
2549 above, is NARGS. */
2550 tpd2.parms = alloca (sizeof (int) * nargs);
2551 tpd2.level =
2552 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
2555 /* Mark the template parameters. But this time, we're
2556 looking for the template parameters of the main
2557 template, not in the specialization. */
2558 tpd2.current_arg = i;
2559 tpd2.arg_uses_template_parms[i] = 0;
2560 memset (tpd2.parms, 0, sizeof (int) * nargs);
2561 for_each_template_parm (type,
2562 &mark_template_parm,
2563 &tpd2,
2564 NULL);
2566 if (tpd2.arg_uses_template_parms [i])
2568 /* The type depended on some template parameters.
2569 If they are fully specialized in the
2570 specialization, that's OK. */
2571 int j;
2572 for (j = 0; j < nargs; ++j)
2573 if (tpd2.parms[j] != 0
2574 && tpd.arg_uses_template_parms [j])
2576 error ("type `%T' of template argument `%E' depends on template parameter(s)",
2577 type,
2578 arg);
2579 break;
2586 if (retrieve_specialization (maintmpl, specargs))
2587 /* We've already got this specialization. */
2588 return decl;
2590 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
2591 = tree_cons (inner_args, inner_parms,
2592 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
2593 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
2594 return decl;
2597 /* Check that a template declaration's use of default arguments is not
2598 invalid. Here, PARMS are the template parameters. IS_PRIMARY is
2599 nonzero if DECL is the thing declared by a primary template.
2600 IS_PARTIAL is nonzero if DECL is a partial specialization. */
2602 static void
2603 check_default_tmpl_args (tree decl, tree parms, int is_primary, int is_partial)
2605 const char *msg;
2606 int last_level_to_check;
2607 tree parm_level;
2609 /* [temp.param]
2611 A default template-argument shall not be specified in a
2612 function template declaration or a function template definition, nor
2613 in the template-parameter-list of the definition of a member of a
2614 class template. */
2616 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
2617 /* You can't have a function template declaration in a local
2618 scope, nor you can you define a member of a class template in a
2619 local scope. */
2620 return;
2622 if (current_class_type
2623 && !TYPE_BEING_DEFINED (current_class_type)
2624 && DECL_LANG_SPECIFIC (decl)
2625 /* If this is either a friend defined in the scope of the class
2626 or a member function. */
2627 && (DECL_FUNCTION_MEMBER_P (decl)
2628 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
2629 : DECL_FRIEND_CONTEXT (decl)
2630 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
2631 : false)
2632 /* And, if it was a member function, it really was defined in
2633 the scope of the class. */
2634 && (!DECL_FUNCTION_MEMBER_P (decl)
2635 || DECL_INITIALIZED_IN_CLASS_P (decl)))
2636 /* We already checked these parameters when the template was
2637 declared, so there's no need to do it again now. This function
2638 was defined in class scope, but we're processing it's body now
2639 that the class is complete. */
2640 return;
2642 /* [temp.param]
2644 If a template-parameter has a default template-argument, all
2645 subsequent template-parameters shall have a default
2646 template-argument supplied. */
2647 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
2649 tree inner_parms = TREE_VALUE (parm_level);
2650 int ntparms = TREE_VEC_LENGTH (inner_parms);
2651 int seen_def_arg_p = 0;
2652 int i;
2654 for (i = 0; i < ntparms; ++i)
2656 tree parm = TREE_VEC_ELT (inner_parms, i);
2657 if (TREE_PURPOSE (parm))
2658 seen_def_arg_p = 1;
2659 else if (seen_def_arg_p)
2661 error ("no default argument for `%D'", TREE_VALUE (parm));
2662 /* For better subsequent error-recovery, we indicate that
2663 there should have been a default argument. */
2664 TREE_PURPOSE (parm) = error_mark_node;
2669 if (TREE_CODE (decl) != TYPE_DECL || is_partial || !is_primary)
2670 /* For an ordinary class template, default template arguments are
2671 allowed at the innermost level, e.g.:
2672 template <class T = int>
2673 struct S {};
2674 but, in a partial specialization, they're not allowed even
2675 there, as we have in [temp.class.spec]:
2677 The template parameter list of a specialization shall not
2678 contain default template argument values.
2680 So, for a partial specialization, or for a function template,
2681 we look at all of them. */
2683 else
2684 /* But, for a primary class template that is not a partial
2685 specialization we look at all template parameters except the
2686 innermost ones. */
2687 parms = TREE_CHAIN (parms);
2689 /* Figure out what error message to issue. */
2690 if (TREE_CODE (decl) == FUNCTION_DECL)
2691 msg = "default template arguments may not be used in function templates";
2692 else if (is_partial)
2693 msg = "default template arguments may not be used in partial specializations";
2694 else
2695 msg = "default argument for template parameter for class enclosing `%D'";
2697 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
2698 /* If we're inside a class definition, there's no need to
2699 examine the parameters to the class itself. On the one
2700 hand, they will be checked when the class is defined, and,
2701 on the other, default arguments are valid in things like:
2702 template <class T = double>
2703 struct S { template <class U> void f(U); };
2704 Here the default argument for `S' has no bearing on the
2705 declaration of `f'. */
2706 last_level_to_check = template_class_depth (current_class_type) + 1;
2707 else
2708 /* Check everything. */
2709 last_level_to_check = 0;
2711 for (parm_level = parms;
2712 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
2713 parm_level = TREE_CHAIN (parm_level))
2715 tree inner_parms = TREE_VALUE (parm_level);
2716 int i;
2717 int ntparms;
2719 ntparms = TREE_VEC_LENGTH (inner_parms);
2720 for (i = 0; i < ntparms; ++i)
2721 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
2723 if (msg)
2725 error (msg, decl);
2726 msg = 0;
2729 /* Clear out the default argument so that we are not
2730 confused later. */
2731 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
2734 /* At this point, if we're still interested in issuing messages,
2735 they must apply to classes surrounding the object declared. */
2736 if (msg)
2737 msg = "default argument for template parameter for class enclosing `%D'";
2741 /* Worker for push_template_decl_real, called via
2742 for_each_template_parm. DATA is really an int, indicating the
2743 level of the parameters we are interested in. If T is a template
2744 parameter of that level, return nonzero. */
2746 static int
2747 template_parm_this_level_p (tree t, void* data)
2749 int this_level = *(int *)data;
2750 int level;
2752 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
2753 level = TEMPLATE_PARM_LEVEL (t);
2754 else
2755 level = TEMPLATE_TYPE_LEVEL (t);
2756 return level == this_level;
2759 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
2760 parameters given by current_template_args, or reuses a
2761 previously existing one, if appropriate. Returns the DECL, or an
2762 equivalent one, if it is replaced via a call to duplicate_decls.
2764 If IS_FRIEND is nonzero, DECL is a friend declaration. */
2766 tree
2767 push_template_decl_real (tree decl, int is_friend)
2769 tree tmpl;
2770 tree args;
2771 tree info;
2772 tree ctx;
2773 int primary;
2774 int is_partial;
2775 int new_template_p = 0;
2777 /* See if this is a partial specialization. */
2778 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
2779 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
2780 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
2782 is_friend |= (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl));
2784 if (is_friend)
2785 /* For a friend, we want the context of the friend function, not
2786 the type of which it is a friend. */
2787 ctx = DECL_CONTEXT (decl);
2788 else if (CP_DECL_CONTEXT (decl)
2789 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
2790 /* In the case of a virtual function, we want the class in which
2791 it is defined. */
2792 ctx = CP_DECL_CONTEXT (decl);
2793 else
2794 /* Otherwise, if we're currently defining some class, the DECL
2795 is assumed to be a member of the class. */
2796 ctx = current_scope ();
2798 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
2799 ctx = NULL_TREE;
2801 if (!DECL_CONTEXT (decl))
2802 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
2804 /* See if this is a primary template. */
2805 primary = template_parm_scope_p ();
2807 if (primary)
2809 if (current_lang_name == lang_name_c)
2810 error ("template with C linkage");
2811 else if (TREE_CODE (decl) == TYPE_DECL
2812 && ANON_AGGRNAME_P (DECL_NAME (decl)))
2813 error ("template class without a name");
2814 else if (TREE_CODE (decl) == FUNCTION_DECL
2815 && DECL_DESTRUCTOR_P (decl))
2817 /* [temp.mem]
2819 A destructor shall not be a member template. */
2820 error ("destructor `%D' declared as member template", decl);
2821 return error_mark_node;
2823 else if ((DECL_IMPLICIT_TYPEDEF_P (decl)
2824 && CLASS_TYPE_P (TREE_TYPE (decl)))
2825 || (TREE_CODE (decl) == VAR_DECL && ctx && CLASS_TYPE_P (ctx))
2826 || TREE_CODE (decl) == FUNCTION_DECL)
2827 /* OK */;
2828 else
2830 error ("template declaration of `%#D'", decl);
2831 return error_mark_node;
2835 /* Check to see that the rules regarding the use of default
2836 arguments are not being violated. */
2837 check_default_tmpl_args (decl, current_template_parms,
2838 primary, is_partial);
2840 if (is_partial)
2841 return process_partial_specialization (decl);
2843 args = current_template_args ();
2845 if (!ctx
2846 || TREE_CODE (ctx) == FUNCTION_DECL
2847 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
2848 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
2850 if (DECL_LANG_SPECIFIC (decl)
2851 && DECL_TEMPLATE_INFO (decl)
2852 && DECL_TI_TEMPLATE (decl))
2853 tmpl = DECL_TI_TEMPLATE (decl);
2854 /* If DECL is a TYPE_DECL for a class-template, then there won't
2855 be DECL_LANG_SPECIFIC. The information equivalent to
2856 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
2857 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
2858 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
2859 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
2861 /* Since a template declaration already existed for this
2862 class-type, we must be redeclaring it here. Make sure
2863 that the redeclaration is valid. */
2864 redeclare_class_template (TREE_TYPE (decl),
2865 current_template_parms);
2866 /* We don't need to create a new TEMPLATE_DECL; just use the
2867 one we already had. */
2868 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
2870 else
2872 tmpl = build_template_decl (decl, current_template_parms);
2873 new_template_p = 1;
2875 if (DECL_LANG_SPECIFIC (decl)
2876 && DECL_TEMPLATE_SPECIALIZATION (decl))
2878 /* A specialization of a member template of a template
2879 class. */
2880 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2881 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
2882 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
2886 else
2888 tree a, t, current, parms;
2889 int i;
2891 if (TREE_CODE (decl) == TYPE_DECL)
2893 if ((IS_AGGR_TYPE_CODE (TREE_CODE (TREE_TYPE (decl)))
2894 || TREE_CODE (TREE_TYPE (decl)) == ENUMERAL_TYPE)
2895 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
2896 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
2897 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
2898 else
2900 error ("`%D' does not declare a template type", decl);
2901 return decl;
2904 else if (!DECL_LANG_SPECIFIC (decl) || !DECL_TEMPLATE_INFO (decl))
2906 error ("template definition of non-template `%#D'", decl);
2907 return decl;
2909 else
2910 tmpl = DECL_TI_TEMPLATE (decl);
2912 if (is_member_template (tmpl)
2913 && DECL_FUNCTION_TEMPLATE_P (tmpl)
2914 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
2915 && DECL_TEMPLATE_SPECIALIZATION (decl))
2917 tree new_tmpl;
2919 /* The declaration is a specialization of a member
2920 template, declared outside the class. Therefore, the
2921 innermost template arguments will be NULL, so we
2922 replace them with the arguments determined by the
2923 earlier call to check_explicit_specialization. */
2924 args = DECL_TI_ARGS (decl);
2926 new_tmpl
2927 = build_template_decl (decl, current_template_parms);
2928 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
2929 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
2930 DECL_TI_TEMPLATE (decl) = new_tmpl;
2931 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
2932 DECL_TEMPLATE_INFO (new_tmpl)
2933 = tree_cons (tmpl, args, NULL_TREE);
2935 register_specialization (new_tmpl,
2936 most_general_template (tmpl),
2937 args);
2938 return decl;
2941 /* Make sure the template headers we got make sense. */
2943 parms = DECL_TEMPLATE_PARMS (tmpl);
2944 i = TMPL_PARMS_DEPTH (parms);
2945 if (TMPL_ARGS_DEPTH (args) != i)
2947 error ("expected %d levels of template parms for `%#D', got %d",
2948 i, decl, TMPL_ARGS_DEPTH (args));
2950 else
2951 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
2953 a = TMPL_ARGS_LEVEL (args, i);
2954 t = INNERMOST_TEMPLATE_PARMS (parms);
2956 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
2958 if (current == decl)
2959 error ("got %d template parameters for `%#D'",
2960 TREE_VEC_LENGTH (a), decl);
2961 else
2962 error ("got %d template parameters for `%#T'",
2963 TREE_VEC_LENGTH (a), current);
2964 error (" but %d required", TREE_VEC_LENGTH (t));
2967 /* Perhaps we should also check that the parms are used in the
2968 appropriate qualifying scopes in the declarator? */
2970 if (current == decl)
2971 current = ctx;
2972 else
2973 current = TYPE_CONTEXT (current);
2977 DECL_TEMPLATE_RESULT (tmpl) = decl;
2978 TREE_TYPE (tmpl) = TREE_TYPE (decl);
2980 /* Push template declarations for global functions and types. Note
2981 that we do not try to push a global template friend declared in a
2982 template class; such a thing may well depend on the template
2983 parameters of the class. */
2984 if (new_template_p && !ctx
2985 && !(is_friend && template_class_depth (current_class_type) > 0))
2986 tmpl = pushdecl_namespace_level (tmpl);
2988 if (primary)
2990 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
2991 if (DECL_CONV_FN_P (tmpl))
2993 int depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2995 /* It is a conversion operator. See if the type converted to
2996 depends on innermost template operands. */
2998 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
2999 depth))
3000 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
3004 info = tree_cons (tmpl, args, NULL_TREE);
3006 if (DECL_IMPLICIT_TYPEDEF_P (decl))
3008 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
3009 if ((!ctx || TREE_CODE (ctx) != FUNCTION_DECL)
3010 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
3011 /* Don't change the name if we've already set it up. */
3012 && !IDENTIFIER_TEMPLATE (DECL_NAME (decl)))
3013 DECL_NAME (decl) = classtype_mangled_name (TREE_TYPE (decl));
3015 else if (DECL_LANG_SPECIFIC (decl))
3016 DECL_TEMPLATE_INFO (decl) = info;
3018 return DECL_TEMPLATE_RESULT (tmpl);
3021 tree
3022 push_template_decl (tree decl)
3024 return push_template_decl_real (decl, 0);
3027 /* Called when a class template TYPE is redeclared with the indicated
3028 template PARMS, e.g.:
3030 template <class T> struct S;
3031 template <class T> struct S {}; */
3033 void
3034 redeclare_class_template (tree type, tree parms)
3036 tree tmpl;
3037 tree tmpl_parms;
3038 int i;
3040 if (!TYPE_TEMPLATE_INFO (type))
3042 error ("`%T' is not a template type", type);
3043 return;
3046 tmpl = TYPE_TI_TEMPLATE (type);
3047 if (!PRIMARY_TEMPLATE_P (tmpl))
3048 /* The type is nested in some template class. Nothing to worry
3049 about here; there are no new template parameters for the nested
3050 type. */
3051 return;
3053 parms = INNERMOST_TEMPLATE_PARMS (parms);
3054 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
3056 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
3058 cp_error_at ("previous declaration `%D'", tmpl);
3059 error ("used %d template parameter%s instead of %d",
3060 TREE_VEC_LENGTH (tmpl_parms),
3061 TREE_VEC_LENGTH (tmpl_parms) == 1 ? "" : "s",
3062 TREE_VEC_LENGTH (parms));
3063 return;
3066 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
3068 tree tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
3069 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
3070 tree tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
3071 tree parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
3073 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm))
3075 cp_error_at ("template parameter `%#D'", tmpl_parm);
3076 error ("redeclared here as `%#D'", parm);
3077 return;
3080 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
3082 /* We have in [temp.param]:
3084 A template-parameter may not be given default arguments
3085 by two different declarations in the same scope. */
3086 error ("redefinition of default argument for `%#D'", parm);
3087 error ("%J original definition appeared here", tmpl_parm);
3088 return;
3091 if (parm_default != NULL_TREE)
3092 /* Update the previous template parameters (which are the ones
3093 that will really count) with the new default value. */
3094 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
3095 else if (tmpl_default != NULL_TREE)
3096 /* Update the new parameters, too; they'll be used as the
3097 parameters for any members. */
3098 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
3102 /* Attempt to convert the non-type template parameter EXPR to the
3103 indicated TYPE. If the conversion is successful, return the
3104 converted value. If the conversion is unsuccessful, return
3105 NULL_TREE if we issued an error message, or error_mark_node if we
3106 did not. We issue error messages for out-and-out bad template
3107 parameters, but not simply because the conversion failed, since we
3108 might be just trying to do argument deduction. By the time this
3109 function is called, neither TYPE nor EXPR may make use of template
3110 parameters. */
3112 static tree
3113 convert_nontype_argument (tree type, tree expr)
3115 tree expr_type = TREE_TYPE (expr);
3117 /* A template-argument for a non-type, non-template
3118 template-parameter shall be one of:
3120 --an integral constant-expression of integral or enumeration
3121 type; or
3123 --the name of a non-type template-parameter; or
3125 --the name of an object or function with external linkage,
3126 including function templates and function template-ids but
3127 excluding non-static class members, expressed as id-expression;
3130 --the address of an object or function with external linkage,
3131 including function templates and function template-ids but
3132 excluding non-static class members, expressed as & id-expression
3133 where the & is optional if the name refers to a function or
3134 array; or
3136 --a pointer to member expressed as described in _expr.unary.op_. */
3138 /* An integral constant-expression can include const variables or
3139 enumerators. Simplify things by folding them to their values,
3140 unless we're about to bind the declaration to a reference
3141 parameter. */
3142 if (INTEGRAL_TYPE_P (expr_type)
3143 && TREE_CODE (type) != REFERENCE_TYPE)
3144 expr = decl_constant_value (expr);
3146 if (is_overloaded_fn (expr))
3147 /* OK for now. We'll check that it has external linkage later.
3148 Check this first since if expr_type is the unknown_type_node
3149 we would otherwise complain below. */
3151 else if (TYPE_PTR_TO_MEMBER_P (expr_type))
3153 if (TREE_CODE (expr) != PTRMEM_CST)
3154 goto bad_argument;
3156 else if (TYPE_PTR_P (expr_type)
3157 || TREE_CODE (expr_type) == ARRAY_TYPE
3158 || TREE_CODE (type) == REFERENCE_TYPE
3159 /* If expr is the address of an overloaded function, we
3160 will get the unknown_type_node at this point. */
3161 || expr_type == unknown_type_node)
3163 tree referent;
3164 tree e = expr;
3165 STRIP_NOPS (e);
3167 if (TREE_CODE (expr_type) == ARRAY_TYPE
3168 || (TREE_CODE (type) == REFERENCE_TYPE
3169 && TREE_CODE (e) != ADDR_EXPR))
3170 referent = e;
3171 else
3173 if (TREE_CODE (e) != ADDR_EXPR)
3175 bad_argument:
3176 error ("`%E' is not a valid template argument", expr);
3177 if (TYPE_PTR_P (expr_type))
3179 if (TREE_CODE (TREE_TYPE (expr_type)) == FUNCTION_TYPE)
3180 error ("it must be the address of a function with external linkage");
3181 else
3182 error ("it must be the address of an object with external linkage");
3184 else if (TYPE_PTR_TO_MEMBER_P (expr_type))
3185 error ("it must be a pointer-to-member of the form `&X::Y'");
3187 return NULL_TREE;
3190 referent = TREE_OPERAND (e, 0);
3191 STRIP_NOPS (referent);
3194 if (TREE_CODE (referent) == STRING_CST)
3196 error ("string literal %E is not a valid template argument because it is the address of an object with static linkage",
3197 referent);
3198 return NULL_TREE;
3201 if (TREE_CODE (referent) == SCOPE_REF)
3202 referent = TREE_OPERAND (referent, 1);
3204 if (is_overloaded_fn (referent))
3205 /* We'll check that it has external linkage later. */
3207 else if (TREE_CODE (referent) != VAR_DECL)
3208 goto bad_argument;
3209 else if (!DECL_EXTERNAL_LINKAGE_P (referent))
3211 error ("address of non-extern `%E' cannot be used as template argument", referent);
3212 return error_mark_node;
3215 else if (INTEGRAL_TYPE_P (expr_type) || TYPE_PTR_TO_MEMBER_P (expr_type))
3217 if (! TREE_CONSTANT (expr))
3219 non_constant:
3220 error ("non-constant `%E' cannot be used as template argument",
3221 expr);
3222 return NULL_TREE;
3225 else
3227 if (TYPE_P (expr))
3228 error ("type '%T' cannot be used as a value for a non-type "
3229 "template-parameter", expr);
3230 else if (DECL_P (expr))
3231 error ("invalid use of '%D' as a non-type template-argument", expr);
3232 else
3233 error ("invalid use of '%E' as a non-type template-argument", expr);
3235 return NULL_TREE;
3238 switch (TREE_CODE (type))
3240 case INTEGER_TYPE:
3241 case BOOLEAN_TYPE:
3242 case ENUMERAL_TYPE:
3243 /* For a non-type template-parameter of integral or enumeration
3244 type, integral promotions (_conv.prom_) and integral
3245 conversions (_conv.integral_) are applied. */
3246 if (!INTEGRAL_TYPE_P (expr_type))
3247 return error_mark_node;
3249 /* It's safe to call digest_init in this case; we know we're
3250 just converting one integral constant expression to another. */
3251 expr = digest_init (type, expr, (tree*) 0);
3253 if (TREE_CODE (expr) != INTEGER_CST)
3254 /* Curiously, some TREE_CONSTANT integral expressions do not
3255 simplify to integer constants. For example, `3 % 0',
3256 remains a TRUNC_MOD_EXPR. */
3257 goto non_constant;
3259 return expr;
3261 case OFFSET_TYPE:
3263 tree e;
3265 /* For a non-type template-parameter of type pointer to data
3266 member, qualification conversions (_conv.qual_) are
3267 applied. */
3268 e = perform_qualification_conversions (type, expr);
3269 if (TREE_CODE (e) == NOP_EXPR)
3270 /* The call to perform_qualification_conversions will
3271 insert a NOP_EXPR over EXPR to do express conversion,
3272 if necessary. But, that will confuse us if we use
3273 this (converted) template parameter to instantiate
3274 another template; then the thing will not look like a
3275 valid template argument. So, just make a new
3276 constant, of the appropriate type. */
3277 e = make_ptrmem_cst (type, PTRMEM_CST_MEMBER (expr));
3278 return e;
3281 case POINTER_TYPE:
3283 tree type_pointed_to = TREE_TYPE (type);
3285 if (TREE_CODE (type_pointed_to) == FUNCTION_TYPE)
3287 /* For a non-type template-parameter of type pointer to
3288 function, only the function-to-pointer conversion
3289 (_conv.func_) is applied. If the template-argument
3290 represents a set of overloaded functions (or a pointer to
3291 such), the matching function is selected from the set
3292 (_over.over_). */
3293 tree fns;
3294 tree fn;
3296 if (TREE_CODE (expr) == ADDR_EXPR)
3297 fns = TREE_OPERAND (expr, 0);
3298 else
3299 fns = expr;
3301 fn = instantiate_type (type_pointed_to, fns, tf_none);
3303 if (fn == error_mark_node)
3304 return error_mark_node;
3306 if (!DECL_EXTERNAL_LINKAGE_P (fn))
3308 if (really_overloaded_fn (fns))
3309 return error_mark_node;
3310 else
3311 goto bad_argument;
3314 expr = build_unary_op (ADDR_EXPR, fn, 0);
3316 my_friendly_assert (same_type_p (type, TREE_TYPE (expr)),
3318 return expr;
3320 else
3322 /* For a non-type template-parameter of type pointer to
3323 object, qualification conversions (_conv.qual_) and the
3324 array-to-pointer conversion (_conv.array_) are applied.
3325 [Note: In particular, neither the null pointer conversion
3326 (_conv.ptr_) nor the derived-to-base conversion
3327 (_conv.ptr_) are applied. Although 0 is a valid
3328 template-argument for a non-type template-parameter of
3329 integral type, it is not a valid template-argument for a
3330 non-type template-parameter of pointer type.]
3332 The call to decay_conversion performs the
3333 array-to-pointer conversion, if appropriate. */
3334 expr = decay_conversion (expr);
3336 if (expr == error_mark_node)
3337 return error_mark_node;
3338 else
3339 return perform_qualification_conversions (type, expr);
3342 break;
3344 case REFERENCE_TYPE:
3346 tree type_referred_to = TREE_TYPE (type);
3348 /* If this expression already has reference type, get the
3349 underlying object. */
3350 if (TREE_CODE (expr_type) == REFERENCE_TYPE)
3352 if (TREE_CODE (expr) == NOP_EXPR
3353 && TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR)
3354 STRIP_NOPS (expr);
3355 my_friendly_assert (TREE_CODE (expr) == ADDR_EXPR, 20000604);
3356 expr = TREE_OPERAND (expr, 0);
3357 expr_type = TREE_TYPE (expr);
3360 if (TREE_CODE (type_referred_to) == FUNCTION_TYPE)
3362 /* For a non-type template-parameter of type reference to
3363 function, no conversions apply. If the
3364 template-argument represents a set of overloaded
3365 functions, the matching function is selected from the
3366 set (_over.over_). */
3367 tree fn;
3369 fn = instantiate_type (type_referred_to, expr, tf_none);
3371 if (fn == error_mark_node)
3372 return error_mark_node;
3374 if (!DECL_EXTERNAL_LINKAGE_P (fn))
3376 if (really_overloaded_fn (expr))
3377 /* Don't issue an error here; we might get a different
3378 function if the overloading had worked out
3379 differently. */
3380 return error_mark_node;
3381 else
3382 goto bad_argument;
3385 my_friendly_assert (same_type_p (type_referred_to,
3386 TREE_TYPE (fn)),
3389 expr = fn;
3391 else
3393 /* For a non-type template-parameter of type reference to
3394 object, no conversions apply. The type referred to by the
3395 reference may be more cv-qualified than the (otherwise
3396 identical) type of the template-argument. The
3397 template-parameter is bound directly to the
3398 template-argument, which must be an lvalue. */
3399 if (!same_type_p (TYPE_MAIN_VARIANT (expr_type),
3400 TYPE_MAIN_VARIANT (type_referred_to))
3401 || !at_least_as_qualified_p (type_referred_to,
3402 expr_type)
3403 || !real_lvalue_p (expr))
3404 return error_mark_node;
3407 cxx_mark_addressable (expr);
3408 return build_nop (type, build_address (expr));
3410 break;
3412 case RECORD_TYPE:
3414 my_friendly_assert (TYPE_PTRMEMFUNC_P (type), 20010112);
3416 /* For a non-type template-parameter of type pointer to member
3417 function, no conversions apply. If the template-argument
3418 represents a set of overloaded member functions, the
3419 matching member function is selected from the set
3420 (_over.over_). */
3422 if (!TYPE_PTRMEMFUNC_P (expr_type) &&
3423 expr_type != unknown_type_node)
3424 return error_mark_node;
3426 if (TREE_CODE (expr) == PTRMEM_CST)
3428 /* A ptr-to-member constant. */
3429 if (!same_type_p (type, expr_type))
3430 return error_mark_node;
3431 else
3432 return expr;
3435 if (TREE_CODE (expr) != ADDR_EXPR)
3436 return error_mark_node;
3438 expr = instantiate_type (type, expr, tf_none);
3440 if (expr == error_mark_node)
3441 return error_mark_node;
3443 if (!same_type_p (type, TREE_TYPE (expr)))
3444 return error_mark_node;
3446 return expr;
3448 break;
3450 default:
3451 /* All non-type parameters must have one of these types. */
3452 abort ();
3453 break;
3456 return error_mark_node;
3459 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
3460 template template parameters. Both PARM_PARMS and ARG_PARMS are
3461 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
3462 or PARM_DECL.
3464 ARG_PARMS may contain more parameters than PARM_PARMS. If this is
3465 the case, then extra parameters must have default arguments.
3467 Consider the example:
3468 template <class T, class Allocator = allocator> class vector;
3469 template<template <class U> class TT> class C;
3471 C<vector> is a valid instantiation. PARM_PARMS for the above code
3472 contains a TYPE_DECL (for U), ARG_PARMS contains two TYPE_DECLs (for
3473 T and Allocator) and OUTER_ARGS contains the argument that is used to
3474 substitute the TT parameter. */
3476 static int
3477 coerce_template_template_parms (tree parm_parms,
3478 tree arg_parms,
3479 tsubst_flags_t complain,
3480 tree in_decl,
3481 tree outer_args)
3483 int nparms, nargs, i;
3484 tree parm, arg;
3486 my_friendly_assert (TREE_CODE (parm_parms) == TREE_VEC, 0);
3487 my_friendly_assert (TREE_CODE (arg_parms) == TREE_VEC, 0);
3489 nparms = TREE_VEC_LENGTH (parm_parms);
3490 nargs = TREE_VEC_LENGTH (arg_parms);
3492 /* The rule here is opposite of coerce_template_parms. */
3493 if (nargs < nparms
3494 || (nargs > nparms
3495 && TREE_PURPOSE (TREE_VEC_ELT (arg_parms, nparms)) == NULL_TREE))
3496 return 0;
3498 for (i = 0; i < nparms; ++i)
3500 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
3501 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
3503 if (arg == NULL_TREE || arg == error_mark_node
3504 || parm == NULL_TREE || parm == error_mark_node)
3505 return 0;
3507 if (TREE_CODE (arg) != TREE_CODE (parm))
3508 return 0;
3510 switch (TREE_CODE (parm))
3512 case TYPE_DECL:
3513 break;
3515 case TEMPLATE_DECL:
3516 /* We encounter instantiations of templates like
3517 template <template <template <class> class> class TT>
3518 class C; */
3520 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
3521 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
3523 if (!coerce_template_template_parms
3524 (parmparm, argparm, complain, in_decl, outer_args))
3525 return 0;
3527 break;
3529 case PARM_DECL:
3530 /* The tsubst call is used to handle cases such as
3531 template <class T, template <T> class TT> class D;
3532 i.e. the parameter list of TT depends on earlier parameters. */
3533 if (!same_type_p
3534 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
3535 TREE_TYPE (arg)))
3536 return 0;
3537 break;
3539 default:
3540 abort ();
3543 return 1;
3546 /* Convert the indicated template ARG as necessary to match the
3547 indicated template PARM. Returns the converted ARG, or
3548 error_mark_node if the conversion was unsuccessful. Error and
3549 warning messages are issued under control of COMPLAIN. This
3550 conversion is for the Ith parameter in the parameter list. ARGS is
3551 the full set of template arguments deduced so far. */
3553 static tree
3554 convert_template_argument (tree parm,
3555 tree arg,
3556 tree args,
3557 tsubst_flags_t complain,
3558 int i,
3559 tree in_decl)
3561 tree val;
3562 tree inner_args;
3563 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
3565 inner_args = INNERMOST_TEMPLATE_ARGS (args);
3567 if (TREE_CODE (arg) == TREE_LIST
3568 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
3570 /* The template argument was the name of some
3571 member function. That's usually
3572 invalid, but static members are OK. In any
3573 case, grab the underlying fields/functions
3574 and issue an error later if required. */
3575 arg = TREE_VALUE (arg);
3576 TREE_TYPE (arg) = unknown_type_node;
3579 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
3580 requires_type = (TREE_CODE (parm) == TYPE_DECL
3581 || requires_tmpl_type);
3583 is_tmpl_type = ((TREE_CODE (arg) == TEMPLATE_DECL
3584 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
3585 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
3586 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
3588 if (is_tmpl_type
3589 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
3590 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
3591 arg = TYPE_STUB_DECL (arg);
3593 is_type = TYPE_P (arg) || is_tmpl_type;
3595 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
3596 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
3598 pedwarn ("to refer to a type member of a template parameter, use `typename %E'", arg);
3600 arg = make_typename_type (TREE_OPERAND (arg, 0),
3601 TREE_OPERAND (arg, 1),
3602 complain & tf_error);
3603 is_type = 1;
3605 if (is_type != requires_type)
3607 if (in_decl)
3609 if (complain & tf_error)
3611 error ("type/value mismatch at argument %d in template parameter list for `%D'",
3612 i + 1, in_decl);
3613 if (is_type)
3614 error (" expected a constant of type `%T', got `%T'",
3615 TREE_TYPE (parm),
3616 (is_tmpl_type ? DECL_NAME (arg) : arg));
3617 else if (requires_tmpl_type)
3618 error (" expected a class template, got `%E'", arg);
3619 else
3620 error (" expected a type, got `%E'", arg);
3623 return error_mark_node;
3625 if (is_tmpl_type ^ requires_tmpl_type)
3627 if (in_decl && (complain & tf_error))
3629 error ("type/value mismatch at argument %d in template parameter list for `%D'",
3630 i + 1, in_decl);
3631 if (is_tmpl_type)
3632 error (" expected a type, got `%T'", DECL_NAME (arg));
3633 else
3634 error (" expected a class template, got `%T'", arg);
3636 return error_mark_node;
3639 if (is_type)
3641 if (requires_tmpl_type)
3643 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
3644 /* The number of argument required is not known yet.
3645 Just accept it for now. */
3646 val = TREE_TYPE (arg);
3647 else
3649 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
3650 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
3652 if (coerce_template_template_parms (parmparm, argparm,
3653 complain, in_decl,
3654 inner_args))
3656 val = arg;
3658 /* TEMPLATE_TEMPLATE_PARM node is preferred over
3659 TEMPLATE_DECL. */
3660 if (val != error_mark_node
3661 && DECL_TEMPLATE_TEMPLATE_PARM_P (val))
3662 val = TREE_TYPE (val);
3664 else
3666 if (in_decl && (complain & tf_error))
3668 error ("type/value mismatch at argument %d in template parameter list for `%D'",
3669 i + 1, in_decl);
3670 error (" expected a template of type `%D', got `%D'", parm, arg);
3673 val = error_mark_node;
3677 else
3678 val = groktypename (arg);
3680 else
3682 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
3684 if (invalid_nontype_parm_type_p (t, complain))
3685 return error_mark_node;
3687 if (!uses_template_parms (arg) && !uses_template_parms (t))
3688 /* We used to call digest_init here. However, digest_init
3689 will report errors, which we don't want when complain
3690 is zero. More importantly, digest_init will try too
3691 hard to convert things: for example, `0' should not be
3692 converted to pointer type at this point according to
3693 the standard. Accepting this is not merely an
3694 extension, since deciding whether or not these
3695 conversions can occur is part of determining which
3696 function template to call, or whether a given explicit
3697 argument specification is valid. */
3698 val = convert_nontype_argument (t, arg);
3699 else
3700 val = arg;
3702 if (val == NULL_TREE)
3703 val = error_mark_node;
3704 else if (val == error_mark_node && (complain & tf_error))
3705 error ("could not convert template argument `%E' to `%T'",
3706 arg, t);
3709 return val;
3712 /* Convert all template arguments to their appropriate types, and
3713 return a vector containing the innermost resulting template
3714 arguments. If any error occurs, return error_mark_node. Error and
3715 warning messages are issued under control of COMPLAIN.
3717 If REQUIRE_ALL_ARGUMENTS is nonzero, all arguments must be
3718 provided in ARGLIST, or else trailing parameters must have default
3719 values. If REQUIRE_ALL_ARGUMENTS is zero, we will attempt argument
3720 deduction for any unspecified trailing arguments. */
3722 static tree
3723 coerce_template_parms (tree parms,
3724 tree args,
3725 tree in_decl,
3726 tsubst_flags_t complain,
3727 int require_all_arguments)
3729 int nparms, nargs, i, lost = 0;
3730 tree inner_args;
3731 tree new_args;
3732 tree new_inner_args;
3734 inner_args = INNERMOST_TEMPLATE_ARGS (args);
3735 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
3736 nparms = TREE_VEC_LENGTH (parms);
3738 if (nargs > nparms
3739 || (nargs < nparms
3740 && require_all_arguments
3741 && TREE_PURPOSE (TREE_VEC_ELT (parms, nargs)) == NULL_TREE))
3743 if (complain & tf_error)
3745 error ("wrong number of template arguments (%d, should be %d)",
3746 nargs, nparms);
3748 if (in_decl)
3749 cp_error_at ("provided for `%D'", in_decl);
3752 return error_mark_node;
3755 new_inner_args = make_tree_vec (nparms);
3756 new_args = add_outermost_template_args (args, new_inner_args);
3757 for (i = 0; i < nparms; i++)
3759 tree arg;
3760 tree parm;
3762 /* Get the Ith template parameter. */
3763 parm = TREE_VEC_ELT (parms, i);
3765 /* Calculate the Ith argument. */
3766 if (i < nargs)
3767 arg = TREE_VEC_ELT (inner_args, i);
3768 else if (require_all_arguments)
3769 /* There must be a default arg in this case. */
3770 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
3771 complain, in_decl);
3772 else
3773 break;
3775 my_friendly_assert (arg, 20030727);
3776 if (arg == error_mark_node)
3777 error ("template argument %d is invalid", i + 1);
3778 else
3779 arg = convert_template_argument (TREE_VALUE (parm),
3780 arg, new_args, complain, i,
3781 in_decl);
3783 if (arg == error_mark_node)
3784 lost++;
3785 TREE_VEC_ELT (new_inner_args, i) = arg;
3788 if (lost)
3789 return error_mark_node;
3791 return new_inner_args;
3794 /* Returns 1 if template args OT and NT are equivalent. */
3796 static int
3797 template_args_equal (tree ot, tree nt)
3799 if (nt == ot)
3800 return 1;
3802 if (TREE_CODE (nt) == TREE_VEC)
3803 /* For member templates */
3804 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
3805 else if (TYPE_P (nt))
3806 return TYPE_P (ot) && same_type_p (ot, nt);
3807 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
3808 return 0;
3809 else
3810 return cp_tree_equal (ot, nt);
3813 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
3814 of template arguments. Returns 0 otherwise. */
3817 comp_template_args (tree oldargs, tree newargs)
3819 int i;
3821 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
3822 return 0;
3824 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
3826 tree nt = TREE_VEC_ELT (newargs, i);
3827 tree ot = TREE_VEC_ELT (oldargs, i);
3829 if (! template_args_equal (ot, nt))
3830 return 0;
3832 return 1;
3835 /* Given class template name and parameter list, produce a user-friendly name
3836 for the instantiation. */
3838 static char *
3839 mangle_class_name_for_template (const char* name, tree parms, tree arglist)
3841 static struct obstack scratch_obstack;
3842 static char *scratch_firstobj;
3843 int i, nparms;
3845 if (!scratch_firstobj)
3846 gcc_obstack_init (&scratch_obstack);
3847 else
3848 obstack_free (&scratch_obstack, scratch_firstobj);
3849 scratch_firstobj = obstack_alloc (&scratch_obstack, 1);
3851 #define ccat(C) obstack_1grow (&scratch_obstack, (C));
3852 #define cat(S) obstack_grow (&scratch_obstack, (S), strlen (S))
3854 cat (name);
3855 ccat ('<');
3856 nparms = TREE_VEC_LENGTH (parms);
3857 arglist = INNERMOST_TEMPLATE_ARGS (arglist);
3858 my_friendly_assert (nparms == TREE_VEC_LENGTH (arglist), 268);
3859 for (i = 0; i < nparms; i++)
3861 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
3862 tree arg = TREE_VEC_ELT (arglist, i);
3864 if (i)
3865 ccat (',');
3867 if (TREE_CODE (parm) == TYPE_DECL)
3869 cat (type_as_string (arg, TFF_CHASE_TYPEDEF));
3870 continue;
3872 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3874 if (TREE_CODE (arg) == TEMPLATE_DECL)
3876 /* Already substituted with real template. Just output
3877 the template name here */
3878 tree context = DECL_CONTEXT (arg);
3879 if (context)
3881 /* The template may be defined in a namespace, or
3882 may be a member template. */
3883 my_friendly_assert (TREE_CODE (context) == NAMESPACE_DECL
3884 || CLASS_TYPE_P (context),
3885 980422);
3886 cat(decl_as_string (DECL_CONTEXT (arg), TFF_PLAIN_IDENTIFIER));
3887 cat("::");
3889 cat (IDENTIFIER_POINTER (DECL_NAME (arg)));
3891 else
3892 /* Output the parameter declaration */
3893 cat (type_as_string (arg, TFF_CHASE_TYPEDEF));
3894 continue;
3896 else
3897 my_friendly_assert (TREE_CODE (parm) == PARM_DECL, 269);
3899 /* No need to check arglist against parmlist here; we did that
3900 in coerce_template_parms, called from lookup_template_class. */
3901 cat (expr_as_string (arg, TFF_PLAIN_IDENTIFIER));
3904 char *bufp = obstack_next_free (&scratch_obstack);
3905 int offset = 0;
3906 while (bufp[offset - 1] == ' ')
3907 offset--;
3908 obstack_blank_fast (&scratch_obstack, offset);
3910 /* B<C<char> >, not B<C<char>> */
3911 if (bufp[offset - 1] == '>')
3912 ccat (' ');
3914 ccat ('>');
3915 ccat ('\0');
3916 return (char *) obstack_base (&scratch_obstack);
3919 static tree
3920 classtype_mangled_name (tree t)
3922 if (CLASSTYPE_TEMPLATE_INFO (t)
3923 /* Specializations have already had their names set up in
3924 lookup_template_class. */
3925 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
3927 tree tmpl = most_general_template (CLASSTYPE_TI_TEMPLATE (t));
3929 /* For non-primary templates, the template parameters are
3930 implicit from their surrounding context. */
3931 if (PRIMARY_TEMPLATE_P (tmpl))
3933 tree name = DECL_NAME (tmpl);
3934 char *mangled_name = mangle_class_name_for_template
3935 (IDENTIFIER_POINTER (name),
3936 DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
3937 CLASSTYPE_TI_ARGS (t));
3938 tree id = get_identifier (mangled_name);
3939 IDENTIFIER_TEMPLATE (id) = name;
3940 return id;
3944 return TYPE_IDENTIFIER (t);
3947 static void
3948 add_pending_template (tree d)
3950 tree ti = (TYPE_P (d)
3951 ? CLASSTYPE_TEMPLATE_INFO (d)
3952 : DECL_TEMPLATE_INFO (d));
3953 tree pt;
3954 int level;
3956 if (TI_PENDING_TEMPLATE_FLAG (ti))
3957 return;
3959 /* We are called both from instantiate_decl, where we've already had a
3960 tinst_level pushed, and instantiate_template, where we haven't.
3961 Compensate. */
3962 level = !(current_tinst_level && TINST_DECL (current_tinst_level) == d);
3964 if (level)
3965 push_tinst_level (d);
3967 pt = tree_cons (current_tinst_level, d, NULL_TREE);
3968 if (last_pending_template)
3969 TREE_CHAIN (last_pending_template) = pt;
3970 else
3971 pending_templates = pt;
3973 last_pending_template = pt;
3975 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
3977 if (level)
3978 pop_tinst_level ();
3982 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
3983 ARGLIST. Valid choices for FNS are given in the cp-tree.def
3984 documentation for TEMPLATE_ID_EXPR. */
3986 tree
3987 lookup_template_function (tree fns, tree arglist)
3989 tree type;
3991 if (fns == error_mark_node || arglist == error_mark_node)
3992 return error_mark_node;
3994 my_friendly_assert (!arglist || TREE_CODE (arglist) == TREE_VEC, 20030726);
3995 if (fns == NULL_TREE
3996 || TREE_CODE (fns) == FUNCTION_DECL)
3998 error ("non-template used as template");
3999 return error_mark_node;
4002 my_friendly_assert (TREE_CODE (fns) == TEMPLATE_DECL
4003 || TREE_CODE (fns) == OVERLOAD
4004 || BASELINK_P (fns)
4005 || TREE_CODE (fns) == IDENTIFIER_NODE,
4006 20020730);
4008 if (BASELINK_P (fns))
4010 BASELINK_FUNCTIONS (fns) = build (TEMPLATE_ID_EXPR,
4011 unknown_type_node,
4012 BASELINK_FUNCTIONS (fns),
4013 arglist);
4014 return fns;
4017 type = TREE_TYPE (fns);
4018 if (TREE_CODE (fns) == OVERLOAD || !type)
4019 type = unknown_type_node;
4021 return build (TEMPLATE_ID_EXPR, type, fns, arglist);
4024 /* Within the scope of a template class S<T>, the name S gets bound
4025 (in build_self_reference) to a TYPE_DECL for the class, not a
4026 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
4027 or one of its enclosing classes, and that type is a template,
4028 return the associated TEMPLATE_DECL. Otherwise, the original
4029 DECL is returned. */
4031 tree
4032 maybe_get_template_decl_from_type_decl (tree decl)
4034 return (decl != NULL_TREE
4035 && TREE_CODE (decl) == TYPE_DECL
4036 && DECL_ARTIFICIAL (decl)
4037 && CLASS_TYPE_P (TREE_TYPE (decl))
4038 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
4039 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
4042 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
4043 parameters, find the desired type.
4045 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
4047 IN_DECL, if non-NULL, is the template declaration we are trying to
4048 instantiate.
4050 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
4051 the class we are looking up.
4053 Issue error and warning messages under control of COMPLAIN.
4055 If the template class is really a local class in a template
4056 function, then the FUNCTION_CONTEXT is the function in which it is
4057 being instantiated. */
4059 tree
4060 lookup_template_class (tree d1,
4061 tree arglist,
4062 tree in_decl,
4063 tree context,
4064 int entering_scope,
4065 tsubst_flags_t complain)
4067 tree template = NULL_TREE, parmlist;
4068 tree t;
4070 timevar_push (TV_NAME_LOOKUP);
4072 if (TREE_CODE (d1) == IDENTIFIER_NODE)
4074 if (IDENTIFIER_VALUE (d1)
4075 && DECL_TEMPLATE_TEMPLATE_PARM_P (IDENTIFIER_VALUE (d1)))
4076 template = IDENTIFIER_VALUE (d1);
4077 else
4079 if (context)
4080 push_decl_namespace (context);
4081 template = lookup_name (d1, /*prefer_type=*/0);
4082 template = maybe_get_template_decl_from_type_decl (template);
4083 if (context)
4084 pop_decl_namespace ();
4086 if (template)
4087 context = DECL_CONTEXT (template);
4089 else if (TREE_CODE (d1) == TYPE_DECL && IS_AGGR_TYPE (TREE_TYPE (d1)))
4091 tree type = TREE_TYPE (d1);
4093 /* If we are declaring a constructor, say A<T>::A<T>, we will get
4094 an implicit typename for the second A. Deal with it. */
4095 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
4096 type = TREE_TYPE (type);
4098 if (CLASSTYPE_TEMPLATE_INFO (type))
4100 template = CLASSTYPE_TI_TEMPLATE (type);
4101 d1 = DECL_NAME (template);
4104 else if (TREE_CODE (d1) == ENUMERAL_TYPE
4105 || (TYPE_P (d1) && IS_AGGR_TYPE (d1)))
4107 template = TYPE_TI_TEMPLATE (d1);
4108 d1 = DECL_NAME (template);
4110 else if (TREE_CODE (d1) == TEMPLATE_DECL
4111 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
4113 template = d1;
4114 d1 = DECL_NAME (template);
4115 context = DECL_CONTEXT (template);
4118 /* With something like `template <class T> class X class X { ... };'
4119 we could end up with D1 having nothing but an IDENTIFIER_VALUE.
4120 We don't want to do that, but we have to deal with the situation,
4121 so let's give them some syntax errors to chew on instead of a
4122 crash. Alternatively D1 might not be a template type at all. */
4123 if (! template)
4125 if (complain & tf_error)
4126 error ("`%T' is not a template", d1);
4127 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4130 if (TREE_CODE (template) != TEMPLATE_DECL
4131 /* Make sure it's a user visible template, if it was named by
4132 the user. */
4133 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (template)
4134 && !PRIMARY_TEMPLATE_P (template)))
4136 if (complain & tf_error)
4138 error ("non-template type `%T' used as a template", d1);
4139 if (in_decl)
4140 cp_error_at ("for template declaration `%D'", in_decl);
4142 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4145 complain &= ~tf_user;
4147 if (DECL_TEMPLATE_TEMPLATE_PARM_P (template))
4149 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
4150 template arguments */
4152 tree parm;
4153 tree arglist2;
4155 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (template);
4157 /* Consider an example where a template template parameter declared as
4159 template <class T, class U = std::allocator<T> > class TT
4161 The template parameter level of T and U are one level larger than
4162 of TT. To proper process the default argument of U, say when an
4163 instantiation `TT<int>' is seen, we need to build the full
4164 arguments containing {int} as the innermost level. Outer levels,
4165 available when not appearing as default template argument, can be
4166 obtained from `current_template_args ()'.
4168 Suppose that TT is later substituted with std::vector. The above
4169 instantiation is `TT<int, std::allocator<T> >' with TT at
4170 level 1, and T at level 2, while the template arguments at level 1
4171 becomes {std::vector} and the inner level 2 is {int}. */
4173 if (current_template_parms)
4174 arglist = add_to_template_args (current_template_args (), arglist);
4176 arglist2 = coerce_template_parms (parmlist, arglist, template,
4177 complain, /*require_all_args=*/1);
4178 if (arglist2 == error_mark_node
4179 || (!uses_template_parms (arglist2)
4180 && check_instantiated_args (template, arglist2, complain)))
4181 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4183 parm = bind_template_template_parm (TREE_TYPE (template), arglist2);
4184 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
4186 else
4188 tree template_type = TREE_TYPE (template);
4189 tree gen_tmpl;
4190 tree type_decl;
4191 tree found = NULL_TREE;
4192 tree *tp;
4193 int arg_depth;
4194 int parm_depth;
4195 int is_partial_instantiation;
4197 gen_tmpl = most_general_template (template);
4198 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
4199 parm_depth = TMPL_PARMS_DEPTH (parmlist);
4200 arg_depth = TMPL_ARGS_DEPTH (arglist);
4202 if (arg_depth == 1 && parm_depth > 1)
4204 /* We've been given an incomplete set of template arguments.
4205 For example, given:
4207 template <class T> struct S1 {
4208 template <class U> struct S2 {};
4209 template <class U> struct S2<U*> {};
4212 we will be called with an ARGLIST of `U*', but the
4213 TEMPLATE will be `template <class T> template
4214 <class U> struct S1<T>::S2'. We must fill in the missing
4215 arguments. */
4216 arglist
4217 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (template)),
4218 arglist);
4219 arg_depth = TMPL_ARGS_DEPTH (arglist);
4222 /* Now we should have enough arguments. */
4223 my_friendly_assert (parm_depth == arg_depth, 0);
4225 /* From here on, we're only interested in the most general
4226 template. */
4227 template = gen_tmpl;
4229 /* Calculate the BOUND_ARGS. These will be the args that are
4230 actually tsubst'd into the definition to create the
4231 instantiation. */
4232 if (parm_depth > 1)
4234 /* We have multiple levels of arguments to coerce, at once. */
4235 int i;
4236 int saved_depth = TMPL_ARGS_DEPTH (arglist);
4238 tree bound_args = make_tree_vec (parm_depth);
4240 for (i = saved_depth,
4241 t = DECL_TEMPLATE_PARMS (template);
4242 i > 0 && t != NULL_TREE;
4243 --i, t = TREE_CHAIN (t))
4245 tree a = coerce_template_parms (TREE_VALUE (t),
4246 arglist, template,
4247 complain, /*require_all_args=*/1);
4249 /* Don't process further if one of the levels fails. */
4250 if (a == error_mark_node)
4252 /* Restore the ARGLIST to its full size. */
4253 TREE_VEC_LENGTH (arglist) = saved_depth;
4254 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4257 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
4259 /* We temporarily reduce the length of the ARGLIST so
4260 that coerce_template_parms will see only the arguments
4261 corresponding to the template parameters it is
4262 examining. */
4263 TREE_VEC_LENGTH (arglist)--;
4266 /* Restore the ARGLIST to its full size. */
4267 TREE_VEC_LENGTH (arglist) = saved_depth;
4269 arglist = bound_args;
4271 else
4272 arglist
4273 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
4274 INNERMOST_TEMPLATE_ARGS (arglist),
4275 template,
4276 complain, /*require_all_args=*/1);
4278 if (arglist == error_mark_node
4279 || (!uses_template_parms (INNERMOST_TEMPLATE_ARGS (arglist))
4280 && check_instantiated_args (template,
4281 INNERMOST_TEMPLATE_ARGS (arglist),
4282 complain)))
4283 /* We were unable to bind the arguments. */
4284 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4286 /* In the scope of a template class, explicit references to the
4287 template class refer to the type of the template, not any
4288 instantiation of it. For example, in:
4290 template <class T> class C { void f(C<T>); }
4292 the `C<T>' is just the same as `C'. Outside of the
4293 class, however, such a reference is an instantiation. */
4294 if (comp_template_args (TYPE_TI_ARGS (template_type),
4295 arglist))
4297 found = template_type;
4299 if (!entering_scope && PRIMARY_TEMPLATE_P (template))
4301 tree ctx;
4303 for (ctx = current_class_type;
4304 ctx && TREE_CODE (ctx) != NAMESPACE_DECL;
4305 ctx = (TYPE_P (ctx)
4306 ? TYPE_CONTEXT (ctx)
4307 : DECL_CONTEXT (ctx)))
4308 if (TYPE_P (ctx) && same_type_p (ctx, template_type))
4309 goto found_ctx;
4311 /* We're not in the scope of the class, so the
4312 TEMPLATE_TYPE is not the type we want after all. */
4313 found = NULL_TREE;
4314 found_ctx:;
4317 if (found)
4318 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
4320 for (tp = &DECL_TEMPLATE_INSTANTIATIONS (template);
4321 *tp;
4322 tp = &TREE_CHAIN (*tp))
4323 if (comp_template_args (TREE_PURPOSE (*tp), arglist))
4325 found = *tp;
4327 /* Use the move-to-front heuristic to speed up future
4328 searches. */
4329 *tp = TREE_CHAIN (*tp);
4330 TREE_CHAIN (found)
4331 = DECL_TEMPLATE_INSTANTIATIONS (template);
4332 DECL_TEMPLATE_INSTANTIATIONS (template) = found;
4334 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, TREE_VALUE (found));
4337 /* This type is a "partial instantiation" if any of the template
4338 arguments still involve template parameters. Note that we set
4339 IS_PARTIAL_INSTANTIATION for partial specializations as
4340 well. */
4341 is_partial_instantiation = uses_template_parms (arglist);
4343 if (!is_partial_instantiation
4344 && !PRIMARY_TEMPLATE_P (template)
4345 && TREE_CODE (CP_DECL_CONTEXT (template)) == NAMESPACE_DECL)
4347 found = xref_tag_from_type (TREE_TYPE (template),
4348 DECL_NAME (template),
4349 /*globalize=*/1);
4350 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
4353 context = tsubst (DECL_CONTEXT (template), arglist,
4354 complain, in_decl);
4355 if (!context)
4356 context = global_namespace;
4358 /* Create the type. */
4359 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
4361 if (!is_partial_instantiation)
4363 set_current_access_from_decl (TYPE_NAME (template_type));
4364 t = start_enum (TYPE_IDENTIFIER (template_type));
4366 else
4367 /* We don't want to call start_enum for this type, since
4368 the values for the enumeration constants may involve
4369 template parameters. And, no one should be interested
4370 in the enumeration constants for such a type. */
4371 t = make_node (ENUMERAL_TYPE);
4373 else
4375 t = make_aggr_type (TREE_CODE (template_type));
4376 CLASSTYPE_DECLARED_CLASS (t)
4377 = CLASSTYPE_DECLARED_CLASS (template_type);
4378 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
4379 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
4381 /* A local class. Make sure the decl gets registered properly. */
4382 if (context == current_function_decl)
4383 pushtag (DECL_NAME (template), t, 0);
4386 /* If we called start_enum or pushtag above, this information
4387 will already be set up. */
4388 if (!TYPE_NAME (t))
4390 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
4392 type_decl = create_implicit_typedef (DECL_NAME (template), t);
4393 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
4394 TYPE_STUB_DECL (t) = type_decl;
4395 DECL_SOURCE_LOCATION (type_decl)
4396 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
4398 else
4399 type_decl = TYPE_NAME (t);
4401 TREE_PRIVATE (type_decl)
4402 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
4403 TREE_PROTECTED (type_decl)
4404 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
4406 /* Set up the template information. We have to figure out which
4407 template is the immediate parent if this is a full
4408 instantiation. */
4409 if (parm_depth == 1 || is_partial_instantiation
4410 || !PRIMARY_TEMPLATE_P (template))
4411 /* This case is easy; there are no member templates involved. */
4412 found = template;
4413 else
4415 /* This is a full instantiation of a member template. Look
4416 for a partial instantiation of which this is an instance. */
4418 for (found = DECL_TEMPLATE_INSTANTIATIONS (template);
4419 found; found = TREE_CHAIN (found))
4421 int success;
4422 tree tmpl = CLASSTYPE_TI_TEMPLATE (TREE_VALUE (found));
4424 /* We only want partial instantiations, here, not
4425 specializations or full instantiations. */
4426 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_VALUE (found))
4427 || !uses_template_parms (TREE_VALUE (found)))
4428 continue;
4430 /* Temporarily reduce by one the number of levels in the
4431 ARGLIST and in FOUND so as to avoid comparing the
4432 last set of arguments. */
4433 TREE_VEC_LENGTH (arglist)--;
4434 TREE_VEC_LENGTH (TREE_PURPOSE (found)) --;
4436 /* See if the arguments match. If they do, then TMPL is
4437 the partial instantiation we want. */
4438 success = comp_template_args (TREE_PURPOSE (found), arglist);
4440 /* Restore the argument vectors to their full size. */
4441 TREE_VEC_LENGTH (arglist)++;
4442 TREE_VEC_LENGTH (TREE_PURPOSE (found))++;
4444 if (success)
4446 found = tmpl;
4447 break;
4451 if (!found)
4453 /* There was no partial instantiation. This happens
4454 where C<T> is a member template of A<T> and it's used
4455 in something like
4457 template <typename T> struct B { A<T>::C<int> m; };
4458 B<float>;
4460 Create the partial instantiation.
4462 TREE_VEC_LENGTH (arglist)--;
4463 found = tsubst (template, arglist, complain, NULL_TREE);
4464 TREE_VEC_LENGTH (arglist)++;
4468 SET_TYPE_TEMPLATE_INFO (t, tree_cons (found, arglist, NULL_TREE));
4469 DECL_TEMPLATE_INSTANTIATIONS (template)
4470 = tree_cons (arglist, t,
4471 DECL_TEMPLATE_INSTANTIATIONS (template));
4473 if (TREE_CODE (t) == ENUMERAL_TYPE
4474 && !is_partial_instantiation)
4475 /* Now that the type has been registered on the instantiations
4476 list, we set up the enumerators. Because the enumeration
4477 constants may involve the enumeration type itself, we make
4478 sure to register the type first, and then create the
4479 constants. That way, doing tsubst_expr for the enumeration
4480 constants won't result in recursive calls here; we'll find
4481 the instantiation and exit above. */
4482 tsubst_enum (template_type, t, arglist);
4484 /* Reset the name of the type, now that CLASSTYPE_TEMPLATE_INFO
4485 is set up. */
4486 if (TREE_CODE (t) != ENUMERAL_TYPE)
4487 DECL_NAME (type_decl) = classtype_mangled_name (t);
4488 if (!is_partial_instantiation)
4490 /* For backwards compatibility; code that uses
4491 -fexternal-templates expects looking up a template to
4492 instantiate it. I think DDD still relies on this.
4493 (jason 8/20/1998) */
4494 if (TREE_CODE (t) != ENUMERAL_TYPE
4495 && flag_external_templates
4496 && CLASSTYPE_INTERFACE_KNOWN (TREE_TYPE (template))
4497 && ! CLASSTYPE_INTERFACE_ONLY (TREE_TYPE (template)))
4498 add_pending_template (t);
4500 else
4501 /* If the type makes use of template parameters, the
4502 code that generates debugging information will crash. */
4503 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
4505 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
4507 timevar_pop (TV_NAME_LOOKUP);
4510 struct pair_fn_data
4512 tree_fn_t fn;
4513 void *data;
4514 htab_t visited;
4517 /* Called from for_each_template_parm via walk_tree. */
4519 static tree
4520 for_each_template_parm_r (tree* tp, int* walk_subtrees, void* d)
4522 tree t = *tp;
4523 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
4524 tree_fn_t fn = pfd->fn;
4525 void *data = pfd->data;
4526 void **slot;
4528 /* If we have already visited this tree, there's no need to walk
4529 subtrees. Otherwise, add it to the visited table. */
4530 slot = htab_find_slot (pfd->visited, *tp, INSERT);
4531 if (*slot)
4533 *walk_subtrees = 0;
4534 return NULL_TREE;
4536 *slot = *tp;
4538 if (TYPE_P (t)
4539 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited))
4540 return error_mark_node;
4542 switch (TREE_CODE (t))
4544 case RECORD_TYPE:
4545 if (TYPE_PTRMEMFUNC_P (t))
4546 break;
4547 /* Fall through. */
4549 case UNION_TYPE:
4550 case ENUMERAL_TYPE:
4551 if (!TYPE_TEMPLATE_INFO (t))
4552 *walk_subtrees = 0;
4553 else if (for_each_template_parm (TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
4554 fn, data, pfd->visited))
4555 return error_mark_node;
4556 break;
4558 case METHOD_TYPE:
4559 /* Since we're not going to walk subtrees, we have to do this
4560 explicitly here. */
4561 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
4562 pfd->visited))
4563 return error_mark_node;
4564 /* Fall through. */
4566 case FUNCTION_TYPE:
4567 /* Check the return type. */
4568 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited))
4569 return error_mark_node;
4571 /* Check the parameter types. Since default arguments are not
4572 instantiated until they are needed, the TYPE_ARG_TYPES may
4573 contain expressions that involve template parameters. But,
4574 no-one should be looking at them yet. And, once they're
4575 instantiated, they don't contain template parameters, so
4576 there's no point in looking at them then, either. */
4578 tree parm;
4580 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
4581 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
4582 pfd->visited))
4583 return error_mark_node;
4585 /* Since we've already handled the TYPE_ARG_TYPES, we don't
4586 want walk_tree walking into them itself. */
4587 *walk_subtrees = 0;
4589 break;
4591 case TYPEOF_TYPE:
4592 if (for_each_template_parm (TYPE_FIELDS (t), fn, data,
4593 pfd->visited))
4594 return error_mark_node;
4595 break;
4597 case FUNCTION_DECL:
4598 case VAR_DECL:
4599 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
4600 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
4601 pfd->visited))
4602 return error_mark_node;
4603 /* Fall through. */
4605 case PARM_DECL:
4606 case CONST_DECL:
4607 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
4608 && for_each_template_parm (DECL_INITIAL (t), fn, data,
4609 pfd->visited))
4610 return error_mark_node;
4611 if (DECL_CONTEXT (t)
4612 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
4613 pfd->visited))
4614 return error_mark_node;
4615 break;
4617 case BOUND_TEMPLATE_TEMPLATE_PARM:
4618 /* Record template parameters such as `T' inside `TT<T>'. */
4619 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited))
4620 return error_mark_node;
4621 /* Fall through. */
4623 case TEMPLATE_TEMPLATE_PARM:
4624 case TEMPLATE_TYPE_PARM:
4625 case TEMPLATE_PARM_INDEX:
4626 if (fn && (*fn)(t, data))
4627 return error_mark_node;
4628 else if (!fn)
4629 return error_mark_node;
4630 break;
4632 case TEMPLATE_DECL:
4633 /* A template template parameter is encountered */
4634 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
4635 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited))
4636 return error_mark_node;
4638 /* Already substituted template template parameter */
4639 *walk_subtrees = 0;
4640 break;
4642 case TYPENAME_TYPE:
4643 if (!fn
4644 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
4645 data, pfd->visited))
4646 return error_mark_node;
4647 break;
4649 case CONSTRUCTOR:
4650 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
4651 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
4652 (TREE_TYPE (t)), fn, data,
4653 pfd->visited))
4654 return error_mark_node;
4655 break;
4657 case INDIRECT_REF:
4658 case COMPONENT_REF:
4659 /* If there's no type, then this thing must be some expression
4660 involving template parameters. */
4661 if (!fn && !TREE_TYPE (t))
4662 return error_mark_node;
4663 break;
4665 case MODOP_EXPR:
4666 case CAST_EXPR:
4667 case REINTERPRET_CAST_EXPR:
4668 case CONST_CAST_EXPR:
4669 case STATIC_CAST_EXPR:
4670 case DYNAMIC_CAST_EXPR:
4671 case ARROW_EXPR:
4672 case DOTSTAR_EXPR:
4673 case TYPEID_EXPR:
4674 case PSEUDO_DTOR_EXPR:
4675 if (!fn)
4676 return error_mark_node;
4677 break;
4679 case BASELINK:
4680 /* If we do not handle this case specially, we end up walking
4681 the BINFO hierarchy, which is circular, and therefore
4682 confuses walk_tree. */
4683 *walk_subtrees = 0;
4684 if (for_each_template_parm (BASELINK_FUNCTIONS (*tp), fn, data,
4685 pfd->visited))
4686 return error_mark_node;
4687 break;
4689 default:
4690 break;
4693 /* We didn't find any template parameters we liked. */
4694 return NULL_TREE;
4697 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
4698 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
4699 call FN with the parameter and the DATA.
4700 If FN returns nonzero, the iteration is terminated, and
4701 for_each_template_parm returns 1. Otherwise, the iteration
4702 continues. If FN never returns a nonzero value, the value
4703 returned by for_each_template_parm is 0. If FN is NULL, it is
4704 considered to be the function which always returns 1. */
4706 static int
4707 for_each_template_parm (tree t, tree_fn_t fn, void* data, htab_t visited)
4709 struct pair_fn_data pfd;
4710 int result;
4712 /* Set up. */
4713 pfd.fn = fn;
4714 pfd.data = data;
4716 /* Walk the tree. (Conceptually, we would like to walk without
4717 duplicates, but for_each_template_parm_r recursively calls
4718 for_each_template_parm, so we would need to reorganize a fair
4719 bit to use walk_tree_without_duplicates, so we keep our own
4720 visited list.) */
4721 if (visited)
4722 pfd.visited = visited;
4723 else
4724 pfd.visited = htab_create (37, htab_hash_pointer, htab_eq_pointer,
4725 NULL);
4726 result = walk_tree (&t,
4727 for_each_template_parm_r,
4728 &pfd,
4729 NULL) != NULL_TREE;
4731 /* Clean up. */
4732 if (!visited)
4733 htab_delete (pfd.visited);
4735 return result;
4738 /* Returns true if T depends on any template parameter. */
4741 uses_template_parms (tree t)
4743 return for_each_template_parm (t, 0, 0, NULL);
4746 /* Returns true if T depends on any template parameter with level LEVEL. */
4749 uses_template_parms_level (tree t, int level)
4751 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL);
4754 static int tinst_depth;
4755 extern int max_tinst_depth;
4756 #ifdef GATHER_STATISTICS
4757 int depth_reached;
4758 #endif
4759 static int tinst_level_tick;
4760 static int last_template_error_tick;
4762 /* We're starting to instantiate D; record the template instantiation context
4763 for diagnostics and to restore it later. */
4766 push_tinst_level (tree d)
4768 tree new;
4770 if (tinst_depth >= max_tinst_depth)
4772 /* If the instantiation in question still has unbound template parms,
4773 we don't really care if we can't instantiate it, so just return.
4774 This happens with base instantiation for implicit `typename'. */
4775 if (uses_template_parms (d))
4776 return 0;
4778 last_template_error_tick = tinst_level_tick;
4779 error ("template instantiation depth exceeds maximum of %d (use -ftemplate-depth-NN to increase the maximum) instantiating `%D'",
4780 max_tinst_depth, d);
4782 print_instantiation_context ();
4784 return 0;
4787 new = build_expr_wfl (d, input_filename, input_line, 0);
4788 TREE_CHAIN (new) = current_tinst_level;
4789 current_tinst_level = new;
4791 ++tinst_depth;
4792 #ifdef GATHER_STATISTICS
4793 if (tinst_depth > depth_reached)
4794 depth_reached = tinst_depth;
4795 #endif
4797 ++tinst_level_tick;
4798 return 1;
4801 /* We're done instantiating this template; return to the instantiation
4802 context. */
4804 void
4805 pop_tinst_level (void)
4807 tree old = current_tinst_level;
4809 /* Restore the filename and line number stashed away when we started
4810 this instantiation. */
4811 input_line = TINST_LINE (old);
4812 input_filename = TINST_FILE (old);
4813 extract_interface_info ();
4815 current_tinst_level = TREE_CHAIN (old);
4816 --tinst_depth;
4817 ++tinst_level_tick;
4820 /* We're instantiating a deferred template; restore the template
4821 instantiation context in which the instantiation was requested, which
4822 is one step out from LEVEL. */
4824 static void
4825 reopen_tinst_level (tree level)
4827 tree t;
4829 tinst_depth = 0;
4830 for (t = level; t; t = TREE_CHAIN (t))
4831 ++tinst_depth;
4833 current_tinst_level = level;
4834 pop_tinst_level ();
4837 /* Return the outermost template instantiation context, for use with
4838 -falt-external-templates. */
4840 tree
4841 tinst_for_decl (void)
4843 tree p = current_tinst_level;
4845 if (p)
4846 for (; TREE_CHAIN (p) ; p = TREE_CHAIN (p))
4848 return p;
4851 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
4852 vector of template arguments, as for tsubst.
4854 Returns an appropriate tsubst'd friend declaration. */
4856 static tree
4857 tsubst_friend_function (tree decl, tree args)
4859 tree new_friend;
4860 location_t saved_loc = input_location;
4862 input_location = DECL_SOURCE_LOCATION (decl);
4864 if (TREE_CODE (decl) == FUNCTION_DECL
4865 && DECL_TEMPLATE_INSTANTIATION (decl)
4866 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
4867 /* This was a friend declared with an explicit template
4868 argument list, e.g.:
4870 friend void f<>(T);
4872 to indicate that f was a template instantiation, not a new
4873 function declaration. Now, we have to figure out what
4874 instantiation of what template. */
4876 tree template_id, arglist, fns;
4877 tree new_args;
4878 tree tmpl;
4879 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
4881 /* Friend functions are looked up in the containing namespace scope.
4882 We must enter that scope, to avoid finding member functions of the
4883 current cless with same name. */
4884 push_nested_namespace (ns);
4885 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
4886 tf_error | tf_warning, NULL_TREE);
4887 pop_nested_namespace (ns);
4888 arglist = tsubst (DECL_TI_ARGS (decl), args,
4889 tf_error | tf_warning, NULL_TREE);
4890 template_id = lookup_template_function (fns, arglist);
4892 new_friend = tsubst (decl, args, tf_error | tf_warning, NULL_TREE);
4893 tmpl = determine_specialization (template_id, new_friend,
4894 &new_args,
4895 /*need_member_template=*/0);
4896 new_friend = instantiate_template (tmpl, new_args, tf_error);
4897 goto done;
4900 new_friend = tsubst (decl, args, tf_error | tf_warning, NULL_TREE);
4902 /* The NEW_FRIEND will look like an instantiation, to the
4903 compiler, but is not an instantiation from the point of view of
4904 the language. For example, we might have had:
4906 template <class T> struct S {
4907 template <class U> friend void f(T, U);
4910 Then, in S<int>, template <class U> void f(int, U) is not an
4911 instantiation of anything. */
4912 DECL_USE_TEMPLATE (new_friend) = 0;
4913 if (TREE_CODE (decl) == TEMPLATE_DECL)
4915 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
4916 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
4917 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
4920 /* The mangled name for the NEW_FRIEND is incorrect. The function
4921 is not a template instantiation and should not be mangled like
4922 one. Therefore, we forget the mangling here; we'll recompute it
4923 later if we need it. */
4924 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
4926 SET_DECL_RTL (new_friend, NULL_RTX);
4927 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
4930 if (DECL_NAMESPACE_SCOPE_P (new_friend))
4932 tree old_decl;
4933 tree new_friend_template_info;
4934 tree new_friend_result_template_info;
4935 tree ns;
4936 int new_friend_is_defn;
4938 /* We must save some information from NEW_FRIEND before calling
4939 duplicate decls since that function will free NEW_FRIEND if
4940 possible. */
4941 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
4942 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
4944 /* This declaration is a `primary' template. */
4945 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
4947 new_friend_is_defn
4948 = DECL_INITIAL (DECL_TEMPLATE_RESULT (new_friend)) != NULL_TREE;
4949 new_friend_result_template_info
4950 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
4952 else
4954 new_friend_is_defn = DECL_INITIAL (new_friend) != NULL_TREE;
4955 new_friend_result_template_info = NULL_TREE;
4958 /* Inside pushdecl_namespace_level, we will push into the
4959 current namespace. However, the friend function should go
4960 into the namespace of the template. */
4961 ns = decl_namespace_context (new_friend);
4962 push_nested_namespace (ns);
4963 old_decl = pushdecl_namespace_level (new_friend);
4964 pop_nested_namespace (ns);
4966 if (old_decl != new_friend)
4968 /* This new friend declaration matched an existing
4969 declaration. For example, given:
4971 template <class T> void f(T);
4972 template <class U> class C {
4973 template <class T> friend void f(T) {}
4976 the friend declaration actually provides the definition
4977 of `f', once C has been instantiated for some type. So,
4978 old_decl will be the out-of-class template declaration,
4979 while new_friend is the in-class definition.
4981 But, if `f' was called before this point, the
4982 instantiation of `f' will have DECL_TI_ARGS corresponding
4983 to `T' but not to `U', references to which might appear
4984 in the definition of `f'. Previously, the most general
4985 template for an instantiation of `f' was the out-of-class
4986 version; now it is the in-class version. Therefore, we
4987 run through all specialization of `f', adding to their
4988 DECL_TI_ARGS appropriately. In particular, they need a
4989 new set of outer arguments, corresponding to the
4990 arguments for this class instantiation.
4992 The same situation can arise with something like this:
4994 friend void f(int);
4995 template <class T> class C {
4996 friend void f(T) {}
4999 when `C<int>' is instantiated. Now, `f(int)' is defined
5000 in the class. */
5002 if (!new_friend_is_defn)
5003 /* On the other hand, if the in-class declaration does
5004 *not* provide a definition, then we don't want to alter
5005 existing definitions. We can just leave everything
5006 alone. */
5008 else
5010 /* Overwrite whatever template info was there before, if
5011 any, with the new template information pertaining to
5012 the declaration. */
5013 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
5015 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
5016 reregister_specialization (new_friend,
5017 most_general_template (old_decl),
5018 old_decl);
5019 else
5021 tree t;
5022 tree new_friend_args;
5024 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
5025 = new_friend_result_template_info;
5027 new_friend_args = TI_ARGS (new_friend_template_info);
5028 for (t = DECL_TEMPLATE_SPECIALIZATIONS (old_decl);
5029 t != NULL_TREE;
5030 t = TREE_CHAIN (t))
5032 tree spec = TREE_VALUE (t);
5034 DECL_TI_ARGS (spec)
5035 = add_outermost_template_args (new_friend_args,
5036 DECL_TI_ARGS (spec));
5039 /* Now, since specializations are always supposed to
5040 hang off of the most general template, we must move
5041 them. */
5042 t = most_general_template (old_decl);
5043 if (t != old_decl)
5045 DECL_TEMPLATE_SPECIALIZATIONS (t)
5046 = chainon (DECL_TEMPLATE_SPECIALIZATIONS (t),
5047 DECL_TEMPLATE_SPECIALIZATIONS (old_decl));
5048 DECL_TEMPLATE_SPECIALIZATIONS (old_decl) = NULL_TREE;
5053 /* The information from NEW_FRIEND has been merged into OLD_DECL
5054 by duplicate_decls. */
5055 new_friend = old_decl;
5058 else if (COMPLETE_TYPE_P (DECL_CONTEXT (new_friend)))
5060 /* Check to see that the declaration is really present, and,
5061 possibly obtain an improved declaration. */
5062 tree fn = check_classfn (DECL_CONTEXT (new_friend),
5063 new_friend, false);
5065 if (fn)
5066 new_friend = fn;
5069 done:
5070 input_location = saved_loc;
5071 return new_friend;
5074 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
5075 template arguments, as for tsubst.
5077 Returns an appropriate tsubst'd friend type or error_mark_node on
5078 failure. */
5080 static tree
5081 tsubst_friend_class (tree friend_tmpl, tree args)
5083 tree friend_type;
5084 tree tmpl;
5085 tree context;
5087 context = DECL_CONTEXT (friend_tmpl);
5089 if (context)
5091 if (TREE_CODE (context) == NAMESPACE_DECL)
5092 push_nested_namespace (context);
5093 else
5094 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
5097 /* First, we look for a class template. */
5098 tmpl = lookup_name (DECL_NAME (friend_tmpl), /*prefer_type=*/0);
5100 /* But, if we don't find one, it might be because we're in a
5101 situation like this:
5103 template <class T>
5104 struct S {
5105 template <class U>
5106 friend struct S;
5109 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
5110 for `S<int>', not the TEMPLATE_DECL. */
5111 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
5113 tmpl = lookup_name (DECL_NAME (friend_tmpl), /*prefer_type=*/1);
5114 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
5117 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
5119 /* The friend template has already been declared. Just
5120 check to see that the declarations match, and install any new
5121 default parameters. We must tsubst the default parameters,
5122 of course. We only need the innermost template parameters
5123 because that is all that redeclare_class_template will look
5124 at. */
5125 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
5126 > TMPL_ARGS_DEPTH (args))
5128 tree parms;
5129 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
5130 args, tf_error | tf_warning);
5131 redeclare_class_template (TREE_TYPE (tmpl), parms);
5134 friend_type = TREE_TYPE (tmpl);
5136 else
5138 /* The friend template has not already been declared. In this
5139 case, the instantiation of the template class will cause the
5140 injection of this template into the global scope. */
5141 tmpl = tsubst (friend_tmpl, args, tf_error | tf_warning, NULL_TREE);
5143 /* The new TMPL is not an instantiation of anything, so we
5144 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
5145 the new type because that is supposed to be the corresponding
5146 template decl, i.e., TMPL. */
5147 DECL_USE_TEMPLATE (tmpl) = 0;
5148 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
5149 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
5150 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
5151 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
5153 /* Inject this template into the global scope. */
5154 friend_type = TREE_TYPE (pushdecl_top_level (tmpl));
5157 if (context)
5159 if (TREE_CODE (context) == NAMESPACE_DECL)
5160 pop_nested_namespace (context);
5161 else
5162 pop_nested_class ();
5165 return friend_type;
5168 /* Returns zero if TYPE cannot be completed later due to circularity.
5169 Otherwise returns one. */
5171 static int
5172 can_complete_type_without_circularity (tree type)
5174 if (type == NULL_TREE || type == error_mark_node)
5175 return 0;
5176 else if (COMPLETE_TYPE_P (type))
5177 return 1;
5178 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
5179 return can_complete_type_without_circularity (TREE_TYPE (type));
5180 else if (CLASS_TYPE_P (type)
5181 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
5182 return 0;
5183 else
5184 return 1;
5187 tree
5188 instantiate_class_template (tree type)
5190 tree template, args, pattern, t, member;
5191 tree typedecl;
5192 tree pbinfo;
5194 if (type == error_mark_node)
5195 return error_mark_node;
5197 if (TYPE_BEING_DEFINED (type)
5198 || COMPLETE_TYPE_P (type)
5199 || dependent_type_p (type))
5200 return type;
5202 /* Figure out which template is being instantiated. */
5203 template = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
5204 my_friendly_assert (TREE_CODE (template) == TEMPLATE_DECL, 279);
5206 /* Figure out which arguments are being used to do the
5207 instantiation. */
5208 args = CLASSTYPE_TI_ARGS (type);
5210 /* Determine what specialization of the original template to
5211 instantiate. */
5212 t = most_specialized_class (template, args);
5213 if (t == error_mark_node)
5215 const char *str = "candidates are:";
5216 error ("ambiguous class template instantiation for `%#T'", type);
5217 for (t = DECL_TEMPLATE_SPECIALIZATIONS (template); t;
5218 t = TREE_CHAIN (t))
5220 if (get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t), args))
5222 cp_error_at ("%s %+#T", str, TREE_TYPE (t));
5223 str = " ";
5226 TYPE_BEING_DEFINED (type) = 1;
5227 return error_mark_node;
5230 if (t)
5231 pattern = TREE_TYPE (t);
5232 else
5233 pattern = TREE_TYPE (template);
5235 /* If the template we're instantiating is incomplete, then clearly
5236 there's nothing we can do. */
5237 if (!COMPLETE_TYPE_P (pattern))
5238 return type;
5240 /* If we've recursively instantiated too many templates, stop. */
5241 if (! push_tinst_level (type))
5242 return type;
5244 /* Now we're really doing the instantiation. Mark the type as in
5245 the process of being defined. */
5246 TYPE_BEING_DEFINED (type) = 1;
5248 /* We may be in the middle of deferred access check. Disable
5249 it now. */
5250 push_deferring_access_checks (dk_no_deferred);
5252 maybe_push_to_top_level (uses_template_parms (type));
5254 if (t)
5256 /* This TYPE is actually an instantiation of a partial
5257 specialization. We replace the innermost set of ARGS with
5258 the arguments appropriate for substitution. For example,
5259 given:
5261 template <class T> struct S {};
5262 template <class T> struct S<T*> {};
5264 and supposing that we are instantiating S<int*>, ARGS will
5265 present be {int*} but we need {int}. */
5266 tree inner_args
5267 = get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t),
5268 args);
5270 /* If there were multiple levels in ARGS, replacing the
5271 innermost level would alter CLASSTYPE_TI_ARGS, which we don't
5272 want, so we make a copy first. */
5273 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
5275 args = copy_node (args);
5276 SET_TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args), inner_args);
5278 else
5279 args = inner_args;
5282 if (flag_external_templates)
5284 if (flag_alt_external_templates)
5286 CLASSTYPE_INTERFACE_ONLY (type) = interface_only;
5287 SET_CLASSTYPE_INTERFACE_UNKNOWN_X (type, interface_unknown);
5289 else
5291 CLASSTYPE_INTERFACE_ONLY (type) = CLASSTYPE_INTERFACE_ONLY (pattern);
5292 SET_CLASSTYPE_INTERFACE_UNKNOWN_X
5293 (type, CLASSTYPE_INTERFACE_UNKNOWN (pattern));
5296 else
5298 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
5301 /* Set the input location to the template definition. This is needed
5302 if tsubsting causes an error. */
5303 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (pattern));
5305 TYPE_HAS_CONSTRUCTOR (type) = TYPE_HAS_CONSTRUCTOR (pattern);
5306 TYPE_HAS_DESTRUCTOR (type) = TYPE_HAS_DESTRUCTOR (pattern);
5307 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
5308 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
5309 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
5310 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
5311 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
5312 TYPE_HAS_ABSTRACT_ASSIGN_REF (type) = TYPE_HAS_ABSTRACT_ASSIGN_REF (pattern);
5313 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
5314 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
5315 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
5316 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
5317 TYPE_BASE_CONVS_MAY_REQUIRE_CODE_P (type)
5318 = TYPE_BASE_CONVS_MAY_REQUIRE_CODE_P (pattern);
5319 TYPE_USES_MULTIPLE_INHERITANCE (type)
5320 = TYPE_USES_MULTIPLE_INHERITANCE (pattern);
5321 TYPE_USES_VIRTUAL_BASECLASSES (type)
5322 = TYPE_USES_VIRTUAL_BASECLASSES (pattern);
5323 TYPE_PACKED (type) = TYPE_PACKED (pattern);
5324 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
5325 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
5326 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
5327 if (ANON_AGGR_TYPE_P (pattern))
5328 SET_ANON_AGGR_TYPE_P (type);
5330 pbinfo = TYPE_BINFO (pattern);
5332 #ifdef ENABLE_CHECKING
5333 if (DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
5334 && ! COMPLETE_TYPE_P (TYPE_CONTEXT (type))
5335 && ! TYPE_BEING_DEFINED (TYPE_CONTEXT (type)))
5336 /* We should never instantiate a nested class before its enclosing
5337 class; we need to look up the nested class by name before we can
5338 instantiate it, and that lookup should instantiate the enclosing
5339 class. */
5340 abort ();
5341 #endif
5343 if (BINFO_BASETYPES (pbinfo))
5345 tree base_list = NULL_TREE;
5346 tree pbases = BINFO_BASETYPES (pbinfo);
5347 tree paccesses = BINFO_BASEACCESSES (pbinfo);
5348 tree context = TYPE_CONTEXT (type);
5349 int i;
5351 /* We must enter the scope containing the type, as that is where
5352 the accessibility of types named in dependent bases are
5353 looked up from. */
5354 push_scope (context ? context : global_namespace);
5356 /* Substitute into each of the bases to determine the actual
5357 basetypes. */
5358 for (i = 0; i < TREE_VEC_LENGTH (pbases); ++i)
5360 tree base;
5361 tree access;
5362 tree pbase;
5364 pbase = TREE_VEC_ELT (pbases, i);
5365 access = TREE_VEC_ELT (paccesses, i);
5367 /* Substitute to figure out the base class. */
5368 base = tsubst (BINFO_TYPE (pbase), args, tf_error, NULL_TREE);
5369 if (base == error_mark_node)
5370 continue;
5372 base_list = tree_cons (access, base, base_list);
5373 TREE_VIA_VIRTUAL (base_list) = TREE_VIA_VIRTUAL (pbase);
5376 /* The list is now in reverse order; correct that. */
5377 base_list = nreverse (base_list);
5379 /* Now call xref_basetypes to set up all the base-class
5380 information. */
5381 xref_basetypes (type, base_list);
5383 pop_scope (context ? context : global_namespace);
5386 /* Now that our base classes are set up, enter the scope of the
5387 class, so that name lookups into base classes, etc. will work
5388 correctly. This is precisely analogous to what we do in
5389 begin_class_definition when defining an ordinary non-template
5390 class. */
5391 pushclass (type);
5393 /* Now members are processed in the order of declaration. */
5394 for (member = CLASSTYPE_DECL_LIST (pattern);
5395 member; member = TREE_CHAIN (member))
5397 tree t = TREE_VALUE (member);
5399 if (TREE_PURPOSE (member))
5401 if (TYPE_P (t))
5403 /* Build new CLASSTYPE_NESTED_UTDS. */
5405 tree tag = t;
5406 tree name = TYPE_IDENTIFIER (tag);
5407 tree newtag;
5409 newtag = tsubst (tag, args, tf_error, NULL_TREE);
5410 my_friendly_assert (newtag != error_mark_node, 20010206);
5411 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
5413 if (TYPE_LANG_SPECIFIC (tag) && CLASSTYPE_IS_TEMPLATE (tag))
5414 /* Unfortunately, lookup_template_class sets
5415 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
5416 instantiation (i.e., for the type of a member
5417 template class nested within a template class.)
5418 This behavior is required for
5419 maybe_process_partial_specialization to work
5420 correctly, but is not accurate in this case;
5421 the TAG is not an instantiation of anything.
5422 (The corresponding TEMPLATE_DECL is an
5423 instantiation, but the TYPE is not.) */
5424 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
5426 /* Now, we call pushtag to put this NEWTAG into the scope of
5427 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
5428 pushtag calling push_template_decl. We don't have to do
5429 this for enums because it will already have been done in
5430 tsubst_enum. */
5431 if (name)
5432 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
5433 pushtag (name, newtag, /*globalize=*/0);
5436 else if (TREE_CODE (t) == FUNCTION_DECL
5437 || DECL_FUNCTION_TEMPLATE_P (t))
5439 /* Build new TYPE_METHODS. */
5440 tree r;
5442 if (TREE_CODE (t) == TEMPLATE_DECL)
5443 ++processing_template_decl;
5444 r = tsubst (t, args, tf_error, NULL_TREE);
5445 if (TREE_CODE (t) == TEMPLATE_DECL)
5446 --processing_template_decl;
5447 set_current_access_from_decl (r);
5448 grok_special_member_properties (r);
5449 finish_member_declaration (r);
5451 else
5453 /* Build new TYPE_FIELDS. */
5455 if (TREE_CODE (t) != CONST_DECL)
5457 tree r;
5459 /* The the file and line for this declaration, to
5460 assist in error message reporting. Since we
5461 called push_tinst_level above, we don't need to
5462 restore these. */
5463 input_location = DECL_SOURCE_LOCATION (t);
5465 if (TREE_CODE (t) == TEMPLATE_DECL)
5466 ++processing_template_decl;
5467 r = tsubst (t, args, tf_error | tf_warning, NULL_TREE);
5468 if (TREE_CODE (t) == TEMPLATE_DECL)
5469 --processing_template_decl;
5470 if (TREE_CODE (r) == VAR_DECL)
5472 tree init;
5474 if (DECL_INITIALIZED_IN_CLASS_P (r))
5475 init = tsubst_expr (DECL_INITIAL (t), args,
5476 tf_error | tf_warning, NULL_TREE);
5477 else
5478 init = NULL_TREE;
5480 finish_static_data_member_decl
5481 (r, init, /*asmspec_tree=*/NULL_TREE, /*flags=*/0);
5483 if (DECL_INITIALIZED_IN_CLASS_P (r))
5484 check_static_variable_definition (r, TREE_TYPE (r));
5486 else if (TREE_CODE (r) == FIELD_DECL)
5488 /* Determine whether R has a valid type and can be
5489 completed later. If R is invalid, then it is
5490 replaced by error_mark_node so that it will not be
5491 added to TYPE_FIELDS. */
5492 tree rtype = TREE_TYPE (r);
5493 if (can_complete_type_without_circularity (rtype))
5494 complete_type (rtype);
5496 if (!COMPLETE_TYPE_P (rtype))
5498 cxx_incomplete_type_error (r, rtype);
5499 r = error_mark_node;
5503 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
5504 such a thing will already have been added to the field
5505 list by tsubst_enum in finish_member_declaration in the
5506 CLASSTYPE_NESTED_UTDS case above. */
5507 if (!(TREE_CODE (r) == TYPE_DECL
5508 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
5509 && DECL_ARTIFICIAL (r)))
5511 set_current_access_from_decl (r);
5512 finish_member_declaration (r);
5517 else
5519 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
5521 /* Build new CLASSTYPE_FRIEND_CLASSES. */
5523 tree friend_type = t;
5524 tree new_friend_type;
5526 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5527 new_friend_type = tsubst_friend_class (friend_type, args);
5528 else if (uses_template_parms (friend_type))
5529 new_friend_type = tsubst (friend_type, args,
5530 tf_error | tf_warning, NULL_TREE);
5531 else if (CLASSTYPE_USE_TEMPLATE (friend_type))
5532 new_friend_type = friend_type;
5533 else
5535 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
5537 /* The call to xref_tag_from_type does injection for friend
5538 classes. */
5539 push_nested_namespace (ns);
5540 new_friend_type =
5541 xref_tag_from_type (friend_type, NULL_TREE, 1);
5542 pop_nested_namespace (ns);
5545 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5546 /* Trick make_friend_class into realizing that the friend
5547 we're adding is a template, not an ordinary class. It's
5548 important that we use make_friend_class since it will
5549 perform some error-checking and output cross-reference
5550 information. */
5551 ++processing_template_decl;
5553 if (new_friend_type != error_mark_node)
5554 make_friend_class (type, new_friend_type,
5555 /*complain=*/false);
5557 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5558 --processing_template_decl;
5560 else
5562 /* Build new DECL_FRIENDLIST. */
5563 tree r;
5565 if (TREE_CODE (t) == TEMPLATE_DECL)
5566 ++processing_template_decl;
5567 r = tsubst_friend_function (t, args);
5568 if (TREE_CODE (t) == TEMPLATE_DECL)
5569 --processing_template_decl;
5570 add_friend (type, r, /*complain=*/false);
5575 /* Set the file and line number information to whatever is given for
5576 the class itself. This puts error messages involving generated
5577 implicit functions at a predictable point, and the same point
5578 that would be used for non-template classes. */
5579 typedecl = TYPE_MAIN_DECL (type);
5580 input_location = DECL_SOURCE_LOCATION (typedecl);
5582 unreverse_member_declarations (type);
5583 finish_struct_1 (type);
5585 /* Clear this now so repo_template_used is happy. */
5586 TYPE_BEING_DEFINED (type) = 0;
5587 repo_template_used (type);
5589 /* Now that the class is complete, instantiate default arguments for
5590 any member functions. We don't do this earlier because the
5591 default arguments may reference members of the class. */
5592 if (!PRIMARY_TEMPLATE_P (template))
5593 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
5594 if (TREE_CODE (t) == FUNCTION_DECL
5595 /* Implicitly generated member functions will not have template
5596 information; they are not instantiations, but instead are
5597 created "fresh" for each instantiation. */
5598 && DECL_TEMPLATE_INFO (t))
5599 tsubst_default_arguments (t);
5601 popclass ();
5602 pop_from_top_level ();
5603 pop_deferring_access_checks ();
5604 pop_tinst_level ();
5606 if (TYPE_CONTAINS_VPTR_P (type))
5607 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
5609 return type;
5612 static tree
5613 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
5615 tree r;
5617 if (!t)
5618 r = t;
5619 else if (TYPE_P (t))
5620 r = tsubst (t, args, complain, in_decl);
5621 else
5623 r = tsubst_expr (t, args, complain, in_decl);
5625 if (!uses_template_parms (r))
5627 /* Sometimes, one of the args was an expression involving a
5628 template constant parameter, like N - 1. Now that we've
5629 tsubst'd, we might have something like 2 - 1. This will
5630 confuse lookup_template_class, so we do constant folding
5631 here. We have to unset processing_template_decl, to fool
5632 tsubst_copy_and_build() into building an actual tree. */
5634 /* If the TREE_TYPE of ARG is not NULL_TREE, ARG is already
5635 as simple as it's going to get, and trying to reprocess
5636 the trees will break. Once tsubst_expr et al DTRT for
5637 non-dependent exprs, this code can go away, as the type
5638 will always be set. */
5639 if (!TREE_TYPE (r))
5641 int saved_processing_template_decl = processing_template_decl;
5642 processing_template_decl = 0;
5643 r = tsubst_copy_and_build (r, /*args=*/NULL_TREE,
5644 tf_error, /*in_decl=*/NULL_TREE,
5645 /*function_p=*/false);
5646 processing_template_decl = saved_processing_template_decl;
5648 r = fold (r);
5651 return r;
5654 /* Substitute ARGS into the vector or list of template arguments T. */
5656 static tree
5657 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
5659 int len = TREE_VEC_LENGTH (t);
5660 int need_new = 0, i;
5661 tree *elts = alloca (len * sizeof (tree));
5663 for (i = 0; i < len; i++)
5665 tree orig_arg = TREE_VEC_ELT (t, i);
5666 tree new_arg;
5668 if (TREE_CODE (orig_arg) == TREE_VEC)
5669 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
5670 else
5671 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
5673 if (new_arg == error_mark_node)
5674 return error_mark_node;
5676 elts[i] = new_arg;
5677 if (new_arg != orig_arg)
5678 need_new = 1;
5681 if (!need_new)
5682 return t;
5684 t = make_tree_vec (len);
5685 for (i = 0; i < len; i++)
5686 TREE_VEC_ELT (t, i) = elts[i];
5688 return t;
5691 /* Return the result of substituting ARGS into the template parameters
5692 given by PARMS. If there are m levels of ARGS and m + n levels of
5693 PARMS, then the result will contain n levels of PARMS. For
5694 example, if PARMS is `template <class T> template <class U>
5695 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
5696 result will be `template <int*, double, class V>'. */
5698 static tree
5699 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
5701 tree r = NULL_TREE;
5702 tree* new_parms;
5704 for (new_parms = &r;
5705 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
5706 new_parms = &(TREE_CHAIN (*new_parms)),
5707 parms = TREE_CHAIN (parms))
5709 tree new_vec =
5710 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
5711 int i;
5713 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
5715 tree tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
5716 tree default_value = TREE_PURPOSE (tuple);
5717 tree parm_decl = TREE_VALUE (tuple);
5719 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
5720 default_value = tsubst_template_arg (default_value, args,
5721 complain, NULL_TREE);
5723 tuple = build_tree_list (default_value, parm_decl);
5724 TREE_VEC_ELT (new_vec, i) = tuple;
5727 *new_parms =
5728 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
5729 - TMPL_ARGS_DEPTH (args)),
5730 new_vec, NULL_TREE);
5733 return r;
5736 /* Substitute the ARGS into the indicated aggregate (or enumeration)
5737 type T. If T is not an aggregate or enumeration type, it is
5738 handled as if by tsubst. IN_DECL is as for tsubst. If
5739 ENTERING_SCOPE is nonzero, T is the context for a template which
5740 we are presently tsubst'ing. Return the substituted value. */
5742 static tree
5743 tsubst_aggr_type (tree t,
5744 tree args,
5745 tsubst_flags_t complain,
5746 tree in_decl,
5747 int entering_scope)
5749 if (t == NULL_TREE)
5750 return NULL_TREE;
5752 switch (TREE_CODE (t))
5754 case RECORD_TYPE:
5755 if (TYPE_PTRMEMFUNC_P (t))
5756 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
5758 /* else fall through */
5759 case ENUMERAL_TYPE:
5760 case UNION_TYPE:
5761 if (TYPE_TEMPLATE_INFO (t))
5763 tree argvec;
5764 tree context;
5765 tree r;
5767 /* First, determine the context for the type we are looking
5768 up. */
5769 context = TYPE_CONTEXT (t);
5770 if (context)
5771 context = tsubst_aggr_type (context, args, complain,
5772 in_decl, /*entering_scope=*/1);
5774 /* Then, figure out what arguments are appropriate for the
5775 type we are trying to find. For example, given:
5777 template <class T> struct S;
5778 template <class T, class U> void f(T, U) { S<U> su; }
5780 and supposing that we are instantiating f<int, double>,
5781 then our ARGS will be {int, double}, but, when looking up
5782 S we only want {double}. */
5783 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
5784 complain, in_decl);
5785 if (argvec == error_mark_node)
5786 return error_mark_node;
5788 r = lookup_template_class (t, argvec, in_decl, context,
5789 entering_scope, complain);
5791 return cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
5793 else
5794 /* This is not a template type, so there's nothing to do. */
5795 return t;
5797 default:
5798 return tsubst (t, args, complain, in_decl);
5802 /* Substitute into the default argument ARG (a default argument for
5803 FN), which has the indicated TYPE. */
5805 tree
5806 tsubst_default_argument (tree fn, tree type, tree arg)
5808 /* This default argument came from a template. Instantiate the
5809 default argument here, not in tsubst. In the case of
5810 something like:
5812 template <class T>
5813 struct S {
5814 static T t();
5815 void f(T = t());
5818 we must be careful to do name lookup in the scope of S<T>,
5819 rather than in the current class.
5821 ??? current_class_type affects a lot more than name lookup. This is
5822 very fragile. Fortunately, it will go away when we do 2-phase name
5823 binding properly. */
5825 /* FN is already the desired FUNCTION_DECL. */
5826 push_access_scope (fn);
5828 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
5829 tf_error | tf_warning, NULL_TREE);
5831 pop_access_scope (fn);
5833 /* Make sure the default argument is reasonable. */
5834 arg = check_default_argument (type, arg);
5836 return arg;
5839 /* Substitute into all the default arguments for FN. */
5841 static void
5842 tsubst_default_arguments (tree fn)
5844 tree arg;
5845 tree tmpl_args;
5847 tmpl_args = DECL_TI_ARGS (fn);
5849 /* If this function is not yet instantiated, we certainly don't need
5850 its default arguments. */
5851 if (uses_template_parms (tmpl_args))
5852 return;
5854 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
5855 arg;
5856 arg = TREE_CHAIN (arg))
5857 if (TREE_PURPOSE (arg))
5858 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
5859 TREE_VALUE (arg),
5860 TREE_PURPOSE (arg));
5863 /* Substitute the ARGS into the T, which is a _DECL. TYPE is the
5864 (already computed) substitution of ARGS into TREE_TYPE (T), if
5865 appropriate. Return the result of the substitution. Issue error
5866 and warning messages under control of COMPLAIN. */
5868 static tree
5869 tsubst_decl (tree t, tree args, tree type, tsubst_flags_t complain)
5871 location_t saved_loc;
5872 tree r = NULL_TREE;
5873 tree in_decl = t;
5875 /* Set the filename and linenumber to improve error-reporting. */
5876 saved_loc = input_location;
5877 input_location = DECL_SOURCE_LOCATION (t);
5879 switch (TREE_CODE (t))
5881 case TEMPLATE_DECL:
5883 /* We can get here when processing a member template function
5884 of a template class. */
5885 tree decl = DECL_TEMPLATE_RESULT (t);
5886 tree spec;
5887 int is_template_template_parm = DECL_TEMPLATE_TEMPLATE_PARM_P (t);
5889 if (!is_template_template_parm)
5891 /* We might already have an instance of this template.
5892 The ARGS are for the surrounding class type, so the
5893 full args contain the tsubst'd args for the context,
5894 plus the innermost args from the template decl. */
5895 tree tmpl_args = DECL_CLASS_TEMPLATE_P (t)
5896 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
5897 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
5898 tree full_args;
5900 full_args = tsubst_template_args (tmpl_args, args,
5901 complain, in_decl);
5903 /* tsubst_template_args doesn't copy the vector if
5904 nothing changed. But, *something* should have
5905 changed. */
5906 my_friendly_assert (full_args != tmpl_args, 0);
5908 spec = retrieve_specialization (t, full_args);
5909 if (spec != NULL_TREE)
5911 r = spec;
5912 break;
5916 /* Make a new template decl. It will be similar to the
5917 original, but will record the current template arguments.
5918 We also create a new function declaration, which is just
5919 like the old one, but points to this new template, rather
5920 than the old one. */
5921 r = copy_decl (t);
5922 my_friendly_assert (DECL_LANG_SPECIFIC (r) != 0, 0);
5923 TREE_CHAIN (r) = NULL_TREE;
5925 if (is_template_template_parm)
5927 tree new_decl = tsubst (decl, args, complain, in_decl);
5928 DECL_TEMPLATE_RESULT (r) = new_decl;
5929 TREE_TYPE (r) = TREE_TYPE (new_decl);
5930 break;
5933 DECL_CONTEXT (r)
5934 = tsubst_aggr_type (DECL_CONTEXT (t), args,
5935 complain, in_decl,
5936 /*entering_scope=*/1);
5937 DECL_TEMPLATE_INFO (r) = build_tree_list (t, args);
5939 if (TREE_CODE (decl) == TYPE_DECL)
5941 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
5942 TREE_TYPE (r) = new_type;
5943 CLASSTYPE_TI_TEMPLATE (new_type) = r;
5944 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
5945 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
5947 else
5949 tree new_decl = tsubst (decl, args, complain, in_decl);
5950 if (new_decl == error_mark_node)
5951 return error_mark_node;
5953 DECL_TEMPLATE_RESULT (r) = new_decl;
5954 DECL_TI_TEMPLATE (new_decl) = r;
5955 TREE_TYPE (r) = TREE_TYPE (new_decl);
5956 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
5959 SET_DECL_IMPLICIT_INSTANTIATION (r);
5960 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
5961 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
5963 /* The template parameters for this new template are all the
5964 template parameters for the old template, except the
5965 outermost level of parameters. */
5966 DECL_TEMPLATE_PARMS (r)
5967 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
5968 complain);
5970 if (PRIMARY_TEMPLATE_P (t))
5971 DECL_PRIMARY_TEMPLATE (r) = r;
5973 if (TREE_CODE (decl) != TYPE_DECL)
5974 /* Record this non-type partial instantiation. */
5975 register_specialization (r, t,
5976 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)));
5978 break;
5980 case FUNCTION_DECL:
5982 tree ctx;
5983 tree argvec = NULL_TREE;
5984 tree *friends;
5985 tree gen_tmpl;
5986 int member;
5987 int args_depth;
5988 int parms_depth;
5990 /* Nobody should be tsubst'ing into non-template functions. */
5991 my_friendly_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE, 0);
5993 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
5995 tree spec;
5996 bool dependent_p;
5998 /* If T is not dependent, just return it. We have to
5999 increment PROCESSING_TEMPLATE_DECL because
6000 value_dependent_expression_p assumes that nothing is
6001 dependent when PROCESSING_TEMPLATE_DECL is zero. */
6002 ++processing_template_decl;
6003 dependent_p = value_dependent_expression_p (t);
6004 --processing_template_decl;
6005 if (!dependent_p)
6006 return t;
6008 /* Calculate the most general template of which R is a
6009 specialization, and the complete set of arguments used to
6010 specialize R. */
6011 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
6012 argvec = tsubst_template_args (DECL_TI_ARGS
6013 (DECL_TEMPLATE_RESULT (gen_tmpl)),
6014 args, complain, in_decl);
6016 /* Check to see if we already have this specialization. */
6017 spec = retrieve_specialization (gen_tmpl, argvec);
6019 if (spec)
6021 r = spec;
6022 break;
6025 /* We can see more levels of arguments than parameters if
6026 there was a specialization of a member template, like
6027 this:
6029 template <class T> struct S { template <class U> void f(); }
6030 template <> template <class U> void S<int>::f(U);
6032 Here, we'll be substituting into the specialization,
6033 because that's where we can find the code we actually
6034 want to generate, but we'll have enough arguments for
6035 the most general template.
6037 We also deal with the peculiar case:
6039 template <class T> struct S {
6040 template <class U> friend void f();
6042 template <class U> void f() {}
6043 template S<int>;
6044 template void f<double>();
6046 Here, the ARGS for the instantiation of will be {int,
6047 double}. But, we only need as many ARGS as there are
6048 levels of template parameters in CODE_PATTERN. We are
6049 careful not to get fooled into reducing the ARGS in
6050 situations like:
6052 template <class T> struct S { template <class U> void f(U); }
6053 template <class T> template <> void S<T>::f(int) {}
6055 which we can spot because the pattern will be a
6056 specialization in this case. */
6057 args_depth = TMPL_ARGS_DEPTH (args);
6058 parms_depth =
6059 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
6060 if (args_depth > parms_depth
6061 && !DECL_TEMPLATE_SPECIALIZATION (t))
6062 args = get_innermost_template_args (args, parms_depth);
6064 else
6066 /* This special case arises when we have something like this:
6068 template <class T> struct S {
6069 friend void f<int>(int, double);
6072 Here, the DECL_TI_TEMPLATE for the friend declaration
6073 will be an IDENTIFIER_NODE. We are being called from
6074 tsubst_friend_function, and we want only to create a
6075 new decl (R) with appropriate types so that we can call
6076 determine_specialization. */
6077 gen_tmpl = NULL_TREE;
6080 if (DECL_CLASS_SCOPE_P (t))
6082 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
6083 member = 2;
6084 else
6085 member = 1;
6086 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
6087 complain, t, /*entering_scope=*/1);
6089 else
6091 member = 0;
6092 ctx = DECL_CONTEXT (t);
6094 type = tsubst (type, args, complain, in_decl);
6095 if (type == error_mark_node)
6096 return error_mark_node;
6098 /* We do NOT check for matching decls pushed separately at this
6099 point, as they may not represent instantiations of this
6100 template, and in any case are considered separate under the
6101 discrete model. */
6102 r = copy_decl (t);
6103 DECL_USE_TEMPLATE (r) = 0;
6104 TREE_TYPE (r) = type;
6105 /* Clear out the mangled name and RTL for the instantiation. */
6106 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
6107 SET_DECL_RTL (r, NULL_RTX);
6109 DECL_CONTEXT (r) = ctx;
6111 if (member && DECL_CONV_FN_P (r))
6112 /* Type-conversion operator. Reconstruct the name, in
6113 case it's the name of one of the template's parameters. */
6114 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
6116 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
6117 complain, t);
6118 DECL_RESULT (r) = NULL_TREE;
6120 TREE_STATIC (r) = 0;
6121 TREE_PUBLIC (r) = TREE_PUBLIC (t);
6122 DECL_EXTERNAL (r) = 1;
6123 DECL_INTERFACE_KNOWN (r) = 0;
6124 DECL_DEFER_OUTPUT (r) = 0;
6125 TREE_CHAIN (r) = NULL_TREE;
6126 DECL_PENDING_INLINE_INFO (r) = 0;
6127 DECL_PENDING_INLINE_P (r) = 0;
6128 DECL_SAVED_TREE (r) = NULL_TREE;
6129 TREE_USED (r) = 0;
6130 if (DECL_CLONED_FUNCTION (r))
6132 DECL_CLONED_FUNCTION (r) = tsubst (DECL_CLONED_FUNCTION (t),
6133 args, complain, t);
6134 TREE_CHAIN (r) = TREE_CHAIN (DECL_CLONED_FUNCTION (r));
6135 TREE_CHAIN (DECL_CLONED_FUNCTION (r)) = r;
6138 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
6139 this in the special friend case mentioned above where
6140 GEN_TMPL is NULL. */
6141 if (gen_tmpl)
6143 DECL_TEMPLATE_INFO (r)
6144 = tree_cons (gen_tmpl, argvec, NULL_TREE);
6145 SET_DECL_IMPLICIT_INSTANTIATION (r);
6146 register_specialization (r, gen_tmpl, argvec);
6148 /* We're not supposed to instantiate default arguments
6149 until they are called, for a template. But, for a
6150 declaration like:
6152 template <class T> void f ()
6153 { extern void g(int i = T()); }
6155 we should do the substitution when the template is
6156 instantiated. We handle the member function case in
6157 instantiate_class_template since the default arguments
6158 might refer to other members of the class. */
6159 if (!member
6160 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6161 && !uses_template_parms (argvec))
6162 tsubst_default_arguments (r);
6165 /* Copy the list of befriending classes. */
6166 for (friends = &DECL_BEFRIENDING_CLASSES (r);
6167 *friends;
6168 friends = &TREE_CHAIN (*friends))
6170 *friends = copy_node (*friends);
6171 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
6172 args, complain,
6173 in_decl);
6176 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
6178 maybe_retrofit_in_chrg (r);
6179 if (DECL_CONSTRUCTOR_P (r))
6180 grok_ctor_properties (ctx, r);
6181 /* If this is an instantiation of a member template, clone it.
6182 If it isn't, that'll be handled by
6183 clone_constructors_and_destructors. */
6184 if (PRIMARY_TEMPLATE_P (gen_tmpl))
6185 clone_function_decl (r, /*update_method_vec_p=*/0);
6187 else if (IDENTIFIER_OPNAME_P (DECL_NAME (r)))
6188 grok_op_properties (r, DECL_FRIEND_P (r),
6189 (complain & tf_error) != 0);
6191 break;
6193 case PARM_DECL:
6195 r = copy_node (t);
6196 if (DECL_TEMPLATE_PARM_P (t))
6197 SET_DECL_TEMPLATE_PARM_P (r);
6199 TREE_TYPE (r) = type;
6200 c_apply_type_quals_to_decl (cp_type_quals (type), r);
6202 if (DECL_INITIAL (r))
6204 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
6205 DECL_INITIAL (r) = TREE_TYPE (r);
6206 else
6207 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
6208 complain, in_decl);
6211 DECL_CONTEXT (r) = NULL_TREE;
6213 if (!DECL_TEMPLATE_PARM_P (r))
6214 DECL_ARG_TYPE (r) = type_passed_as (type);
6215 if (TREE_CHAIN (t))
6216 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
6217 complain, TREE_CHAIN (t));
6219 break;
6221 case FIELD_DECL:
6223 r = copy_decl (t);
6224 TREE_TYPE (r) = type;
6225 c_apply_type_quals_to_decl (cp_type_quals (type), r);
6227 /* We don't have to set DECL_CONTEXT here; it is set by
6228 finish_member_declaration. */
6229 DECL_INITIAL (r) = tsubst_expr (DECL_INITIAL (t), args,
6230 complain, in_decl);
6231 TREE_CHAIN (r) = NULL_TREE;
6232 if (VOID_TYPE_P (type))
6233 cp_error_at ("instantiation of `%D' as type `%T'", r, type);
6235 break;
6237 case USING_DECL:
6239 r = copy_node (t);
6240 /* It is not a dependent using decl any more. */
6241 TREE_TYPE (r) = void_type_node;
6242 DECL_INITIAL (r)
6243 = tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
6244 DECL_NAME (r)
6245 = tsubst_copy (DECL_NAME (t), args, complain, in_decl);
6246 TREE_CHAIN (r) = NULL_TREE;
6248 break;
6250 case TYPE_DECL:
6251 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM
6252 || t == TYPE_MAIN_DECL (TREE_TYPE (t)))
6254 /* If this is the canonical decl, we don't have to mess with
6255 instantiations, and often we can't (for typename, template
6256 type parms and such). Note that TYPE_NAME is not correct for
6257 the above test if we've copied the type for a typedef. */
6258 r = TYPE_NAME (type);
6259 break;
6262 /* Fall through. */
6264 case VAR_DECL:
6266 tree argvec = NULL_TREE;
6267 tree gen_tmpl = NULL_TREE;
6268 tree spec;
6269 tree tmpl = NULL_TREE;
6270 tree ctx;
6271 int local_p;
6273 /* Assume this is a non-local variable. */
6274 local_p = 0;
6276 if (TYPE_P (CP_DECL_CONTEXT (t)))
6277 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
6278 complain,
6279 in_decl, /*entering_scope=*/1);
6280 else if (DECL_NAMESPACE_SCOPE_P (t))
6281 ctx = DECL_CONTEXT (t);
6282 else
6284 /* Subsequent calls to pushdecl will fill this in. */
6285 ctx = NULL_TREE;
6286 local_p = 1;
6289 /* Check to see if we already have this specialization. */
6290 if (!local_p)
6292 tmpl = DECL_TI_TEMPLATE (t);
6293 gen_tmpl = most_general_template (tmpl);
6294 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
6295 spec = retrieve_specialization (gen_tmpl, argvec);
6297 else
6298 spec = retrieve_local_specialization (t);
6300 if (spec)
6302 r = spec;
6303 break;
6306 r = copy_decl (t);
6307 if (TREE_CODE (r) == VAR_DECL)
6309 type = complete_type (type);
6310 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
6311 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
6313 else if (DECL_SELF_REFERENCE_P (t))
6314 SET_DECL_SELF_REFERENCE_P (r);
6315 TREE_TYPE (r) = type;
6316 c_apply_type_quals_to_decl (cp_type_quals (type), r);
6317 DECL_CONTEXT (r) = ctx;
6318 /* Clear out the mangled name and RTL for the instantiation. */
6319 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
6320 SET_DECL_RTL (r, NULL_RTX);
6322 /* Don't try to expand the initializer until someone tries to use
6323 this variable; otherwise we run into circular dependencies. */
6324 DECL_INITIAL (r) = NULL_TREE;
6325 SET_DECL_RTL (r, NULL_RTX);
6326 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
6328 /* Even if the original location is out of scope, the newly
6329 substituted one is not. */
6330 if (TREE_CODE (r) == VAR_DECL)
6332 DECL_DEAD_FOR_LOCAL (r) = 0;
6333 DECL_INITIALIZED_P (r) = 0;
6336 if (!local_p)
6338 /* A static data member declaration is always marked
6339 external when it is declared in-class, even if an
6340 initializer is present. We mimic the non-template
6341 processing here. */
6342 DECL_EXTERNAL (r) = 1;
6344 register_specialization (r, gen_tmpl, argvec);
6345 DECL_TEMPLATE_INFO (r) = tree_cons (tmpl, argvec, NULL_TREE);
6346 SET_DECL_IMPLICIT_INSTANTIATION (r);
6348 else
6349 register_local_specialization (r, t);
6351 TREE_CHAIN (r) = NULL_TREE;
6352 if (TREE_CODE (r) == VAR_DECL && VOID_TYPE_P (type))
6353 cp_error_at ("instantiation of `%D' as type `%T'", r, type);
6354 /* Compute the size, alignment, etc. of R. */
6355 layout_decl (r, 0);
6357 break;
6359 default:
6360 abort ();
6363 /* Restore the file and line information. */
6364 input_location = saved_loc;
6366 return r;
6369 /* Substitute into the ARG_TYPES of a function type. */
6371 static tree
6372 tsubst_arg_types (tree arg_types,
6373 tree args,
6374 tsubst_flags_t complain,
6375 tree in_decl)
6377 tree remaining_arg_types;
6378 tree type;
6380 if (!arg_types || arg_types == void_list_node)
6381 return arg_types;
6383 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
6384 args, complain, in_decl);
6385 if (remaining_arg_types == error_mark_node)
6386 return error_mark_node;
6388 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
6389 if (type == error_mark_node)
6390 return error_mark_node;
6391 if (VOID_TYPE_P (type))
6393 if (complain & tf_error)
6395 error ("invalid parameter type `%T'", type);
6396 if (in_decl)
6397 cp_error_at ("in declaration `%D'", in_decl);
6399 return error_mark_node;
6402 /* Do array-to-pointer, function-to-pointer conversion, and ignore
6403 top-level qualifiers as required. */
6404 type = TYPE_MAIN_VARIANT (type_decays_to (type));
6406 /* Note that we do not substitute into default arguments here. The
6407 standard mandates that they be instantiated only when needed,
6408 which is done in build_over_call. */
6409 return hash_tree_cons (TREE_PURPOSE (arg_types), type,
6410 remaining_arg_types);
6414 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
6415 *not* handle the exception-specification for FNTYPE, because the
6416 initial substitution of explicitly provided template parameters
6417 during argument deduction forbids substitution into the
6418 exception-specification:
6420 [temp.deduct]
6422 All references in the function type of the function template to the
6423 corresponding template parameters are replaced by the specified tem-
6424 plate argument values. If a substitution in a template parameter or
6425 in the function type of the function template results in an invalid
6426 type, type deduction fails. [Note: The equivalent substitution in
6427 exception specifications is done only when the function is instanti-
6428 ated, at which point a program is ill-formed if the substitution
6429 results in an invalid type.] */
6431 static tree
6432 tsubst_function_type (tree t,
6433 tree args,
6434 tsubst_flags_t complain,
6435 tree in_decl)
6437 tree return_type;
6438 tree arg_types;
6439 tree fntype;
6441 /* The TYPE_CONTEXT is not used for function/method types. */
6442 my_friendly_assert (TYPE_CONTEXT (t) == NULL_TREE, 0);
6444 /* Substitute the return type. */
6445 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
6446 if (return_type == error_mark_node)
6447 return error_mark_node;
6449 /* Substitute the argument types. */
6450 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
6451 complain, in_decl);
6452 if (arg_types == error_mark_node)
6453 return error_mark_node;
6455 /* Construct a new type node and return it. */
6456 if (TREE_CODE (t) == FUNCTION_TYPE)
6457 fntype = build_function_type (return_type, arg_types);
6458 else
6460 tree r = TREE_TYPE (TREE_VALUE (arg_types));
6461 if (! IS_AGGR_TYPE (r))
6463 /* [temp.deduct]
6465 Type deduction may fail for any of the following
6466 reasons:
6468 -- Attempting to create "pointer to member of T" when T
6469 is not a class type. */
6470 if (complain & tf_error)
6471 error ("creating pointer to member function of non-class type `%T'",
6473 return error_mark_node;
6476 fntype = build_method_type_directly (r, return_type,
6477 TREE_CHAIN (arg_types));
6479 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
6480 fntype = build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
6482 return fntype;
6485 /* Substitute into the PARMS of a call-declarator. */
6487 static tree
6488 tsubst_call_declarator_parms (tree parms,
6489 tree args,
6490 tsubst_flags_t complain,
6491 tree in_decl)
6493 tree new_parms;
6494 tree type;
6495 tree defarg;
6497 if (!parms || parms == void_list_node)
6498 return parms;
6500 new_parms = tsubst_call_declarator_parms (TREE_CHAIN (parms),
6501 args, complain, in_decl);
6503 /* Figure out the type of this parameter. */
6504 type = tsubst (TREE_VALUE (parms), args, complain, in_decl);
6506 /* Figure out the default argument as well. Note that we use
6507 tsubst_expr since the default argument is really an expression. */
6508 defarg = tsubst_expr (TREE_PURPOSE (parms), args, complain, in_decl);
6510 /* Chain this parameter on to the front of those we have already
6511 processed. We don't use hash_tree_cons because that function
6512 doesn't check TREE_PARMLIST. */
6513 new_parms = tree_cons (defarg, type, new_parms);
6515 /* And note that these are parameters. */
6516 TREE_PARMLIST (new_parms) = 1;
6518 return new_parms;
6521 /* Take the tree structure T and replace template parameters used
6522 therein with the argument vector ARGS. IN_DECL is an associated
6523 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
6524 Issue error and warning messages under control of COMPLAIN. Note
6525 that we must be relatively non-tolerant of extensions here, in
6526 order to preserve conformance; if we allow substitutions that
6527 should not be allowed, we may allow argument deductions that should
6528 not succeed, and therefore report ambiguous overload situations
6529 where there are none. In theory, we could allow the substitution,
6530 but indicate that it should have failed, and allow our caller to
6531 make sure that the right thing happens, but we don't try to do this
6532 yet.
6534 This function is used for dealing with types, decls and the like;
6535 for expressions, use tsubst_expr or tsubst_copy. */
6537 static tree
6538 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
6540 tree type, r;
6542 if (t == NULL_TREE || t == error_mark_node
6543 || t == integer_type_node
6544 || t == void_type_node
6545 || t == char_type_node
6546 || TREE_CODE (t) == NAMESPACE_DECL)
6547 return t;
6549 if (TREE_CODE (t) == IDENTIFIER_NODE)
6550 type = IDENTIFIER_TYPE_VALUE (t);
6551 else
6552 type = TREE_TYPE (t);
6554 my_friendly_assert (type != unknown_type_node, 20030716);
6556 if (type && TREE_CODE (t) != FUNCTION_DECL
6557 && TREE_CODE (t) != TYPENAME_TYPE
6558 && TREE_CODE (t) != TEMPLATE_DECL
6559 && TREE_CODE (t) != IDENTIFIER_NODE
6560 && TREE_CODE (t) != FUNCTION_TYPE
6561 && TREE_CODE (t) != METHOD_TYPE)
6562 type = tsubst (type, args, complain, in_decl);
6563 if (type == error_mark_node)
6564 return error_mark_node;
6566 if (DECL_P (t))
6567 return tsubst_decl (t, args, type, complain);
6569 switch (TREE_CODE (t))
6571 case RECORD_TYPE:
6572 case UNION_TYPE:
6573 case ENUMERAL_TYPE:
6574 return tsubst_aggr_type (t, args, complain, in_decl,
6575 /*entering_scope=*/0);
6577 case ERROR_MARK:
6578 case IDENTIFIER_NODE:
6579 case VOID_TYPE:
6580 case REAL_TYPE:
6581 case COMPLEX_TYPE:
6582 case VECTOR_TYPE:
6583 case BOOLEAN_TYPE:
6584 case INTEGER_CST:
6585 case REAL_CST:
6586 case STRING_CST:
6587 return t;
6589 case INTEGER_TYPE:
6590 if (t == integer_type_node)
6591 return t;
6593 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
6594 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
6595 return t;
6598 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
6600 /* The array dimension behaves like a non-type template arg,
6601 in that we want to fold it as much as possible. */
6602 max = tsubst_template_arg (omax, args, complain, in_decl);
6603 if (!processing_template_decl)
6604 max = decl_constant_value (max);
6606 if (processing_template_decl
6607 /* When providing explicit arguments to a template
6608 function, but leaving some arguments for subsequent
6609 deduction, MAX may be template-dependent even if we're
6610 not PROCESSING_TEMPLATE_DECL. We still need to check for
6611 template parms, though; MAX won't be an INTEGER_CST for
6612 dynamic arrays, either. */
6613 || (TREE_CODE (max) != INTEGER_CST
6614 && uses_template_parms (max)))
6616 tree itype = make_node (INTEGER_TYPE);
6617 TYPE_MIN_VALUE (itype) = size_zero_node;
6618 TYPE_MAX_VALUE (itype) = build_min (MINUS_EXPR, sizetype, max,
6619 integer_one_node);
6620 return itype;
6623 if (integer_zerop (omax))
6625 /* Still allow an explicit array of size zero. */
6626 if (pedantic)
6627 pedwarn ("creating array with size zero");
6629 else if (integer_zerop (max)
6630 || (TREE_CODE (max) == INTEGER_CST
6631 && INT_CST_LT (max, integer_zero_node)))
6633 /* [temp.deduct]
6635 Type deduction may fail for any of the following
6636 reasons:
6638 Attempting to create an array with a size that is
6639 zero or negative. */
6640 if (complain & tf_error)
6641 error ("creating array with size zero (`%E')", max);
6643 return error_mark_node;
6646 return compute_array_index_type (NULL_TREE, max);
6649 case TEMPLATE_TYPE_PARM:
6650 case TEMPLATE_TEMPLATE_PARM:
6651 case BOUND_TEMPLATE_TEMPLATE_PARM:
6652 case TEMPLATE_PARM_INDEX:
6654 int idx;
6655 int level;
6656 int levels;
6658 r = NULL_TREE;
6660 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM
6661 || TREE_CODE (t) == TEMPLATE_TEMPLATE_PARM
6662 || TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
6664 idx = TEMPLATE_TYPE_IDX (t);
6665 level = TEMPLATE_TYPE_LEVEL (t);
6667 else
6669 idx = TEMPLATE_PARM_IDX (t);
6670 level = TEMPLATE_PARM_LEVEL (t);
6673 if (TREE_VEC_LENGTH (args) > 0)
6675 tree arg = NULL_TREE;
6677 levels = TMPL_ARGS_DEPTH (args);
6678 if (level <= levels)
6679 arg = TMPL_ARG (args, level, idx);
6681 if (arg == error_mark_node)
6682 return error_mark_node;
6683 else if (arg != NULL_TREE)
6685 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
6687 my_friendly_assert (TYPE_P (arg), 0);
6688 return cp_build_qualified_type_real
6689 (arg, cp_type_quals (arg) | cp_type_quals (t),
6690 complain | tf_ignore_bad_quals);
6692 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
6694 /* We are processing a type constructed from
6695 a template template parameter */
6696 tree argvec = tsubst (TYPE_TI_ARGS (t),
6697 args, complain, in_decl);
6698 if (argvec == error_mark_node)
6699 return error_mark_node;
6701 /* We can get a TEMPLATE_TEMPLATE_PARM here when
6702 we are resolving nested-types in the signature of
6703 a member function templates.
6704 Otherwise ARG is a TEMPLATE_DECL and is the real
6705 template to be instantiated. */
6706 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
6707 arg = TYPE_NAME (arg);
6709 r = lookup_template_class (arg,
6710 argvec, in_decl,
6711 DECL_CONTEXT (arg),
6712 /*entering_scope=*/0,
6713 complain);
6714 return cp_build_qualified_type_real
6715 (r, TYPE_QUALS (t), complain);
6717 else
6718 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
6719 return arg;
6722 else
6723 abort ();
6725 if (level == 1)
6726 /* This can happen during the attempted tsubst'ing in
6727 unify. This means that we don't yet have any information
6728 about the template parameter in question. */
6729 return t;
6731 /* If we get here, we must have been looking at a parm for a
6732 more deeply nested template. Make a new version of this
6733 template parameter, but with a lower level. */
6734 switch (TREE_CODE (t))
6736 case TEMPLATE_TYPE_PARM:
6737 case TEMPLATE_TEMPLATE_PARM:
6738 case BOUND_TEMPLATE_TEMPLATE_PARM:
6739 if (cp_type_quals (t))
6741 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
6742 r = cp_build_qualified_type_real
6743 (r, cp_type_quals (t),
6744 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
6745 ? tf_ignore_bad_quals : 0));
6747 else
6749 r = copy_type (t);
6750 TEMPLATE_TYPE_PARM_INDEX (r)
6751 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
6752 r, levels);
6753 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
6754 TYPE_MAIN_VARIANT (r) = r;
6755 TYPE_POINTER_TO (r) = NULL_TREE;
6756 TYPE_REFERENCE_TO (r) = NULL_TREE;
6758 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
6760 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
6761 complain, in_decl);
6762 if (argvec == error_mark_node)
6763 return error_mark_node;
6765 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
6766 = tree_cons (TYPE_TI_TEMPLATE (t), argvec, NULL_TREE);
6769 break;
6771 case TEMPLATE_PARM_INDEX:
6772 r = reduce_template_parm_level (t, type, levels);
6773 break;
6775 default:
6776 abort ();
6779 return r;
6782 case TREE_LIST:
6784 tree purpose, value, chain, result;
6786 if (t == void_list_node)
6787 return t;
6789 purpose = TREE_PURPOSE (t);
6790 if (purpose)
6792 purpose = tsubst (purpose, args, complain, in_decl);
6793 if (purpose == error_mark_node)
6794 return error_mark_node;
6796 value = TREE_VALUE (t);
6797 if (value)
6799 value = tsubst (value, args, complain, in_decl);
6800 if (value == error_mark_node)
6801 return error_mark_node;
6803 chain = TREE_CHAIN (t);
6804 if (chain && chain != void_type_node)
6806 chain = tsubst (chain, args, complain, in_decl);
6807 if (chain == error_mark_node)
6808 return error_mark_node;
6810 if (purpose == TREE_PURPOSE (t)
6811 && value == TREE_VALUE (t)
6812 && chain == TREE_CHAIN (t))
6813 return t;
6814 if (TREE_PARMLIST (t))
6816 result = tree_cons (purpose, value, chain);
6817 TREE_PARMLIST (result) = 1;
6819 else
6820 result = hash_tree_cons (purpose, value, chain);
6821 return result;
6823 case TREE_VEC:
6824 if (type != NULL_TREE)
6826 /* A binfo node. We always need to make a copy, of the node
6827 itself and of its BINFO_BASETYPES. */
6829 t = copy_node (t);
6831 /* Make sure type isn't a typedef copy. */
6832 type = BINFO_TYPE (TYPE_BINFO (type));
6834 TREE_TYPE (t) = complete_type (type);
6835 if (IS_AGGR_TYPE (type))
6837 BINFO_VTABLE (t) = TYPE_BINFO_VTABLE (type);
6838 BINFO_VIRTUALS (t) = TYPE_BINFO_VIRTUALS (type);
6839 if (TYPE_BINFO_BASETYPES (type) != NULL_TREE)
6840 BINFO_BASETYPES (t) = copy_node (TYPE_BINFO_BASETYPES (type));
6842 return t;
6845 /* Otherwise, a vector of template arguments. */
6846 return tsubst_template_args (t, args, complain, in_decl);
6848 case POINTER_TYPE:
6849 case REFERENCE_TYPE:
6851 enum tree_code code;
6853 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
6854 return t;
6856 code = TREE_CODE (t);
6859 /* [temp.deduct]
6861 Type deduction may fail for any of the following
6862 reasons:
6864 -- Attempting to create a pointer to reference type.
6865 -- Attempting to create a reference to a reference type or
6866 a reference to void. */
6867 if (TREE_CODE (type) == REFERENCE_TYPE
6868 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
6870 static location_t last_loc;
6872 /* We keep track of the last time we issued this error
6873 message to avoid spewing a ton of messages during a
6874 single bad template instantiation. */
6875 if (complain & tf_error
6876 && (last_loc.line != input_line
6877 || last_loc.file != input_filename))
6879 if (TREE_CODE (type) == VOID_TYPE)
6880 error ("forming reference to void");
6881 else
6882 error ("forming %s to reference type `%T'",
6883 (code == POINTER_TYPE) ? "pointer" : "reference",
6884 type);
6885 last_loc = input_location;
6888 return error_mark_node;
6890 else if (code == POINTER_TYPE)
6892 r = build_pointer_type (type);
6893 if (TREE_CODE (type) == METHOD_TYPE)
6894 r = build_ptrmemfunc_type (r);
6896 else
6897 r = build_reference_type (type);
6898 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
6900 if (r != error_mark_node)
6901 /* Will this ever be needed for TYPE_..._TO values? */
6902 layout_type (r);
6904 return r;
6906 case OFFSET_TYPE:
6908 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
6909 if (r == error_mark_node || !IS_AGGR_TYPE (r))
6911 /* [temp.deduct]
6913 Type deduction may fail for any of the following
6914 reasons:
6916 -- Attempting to create "pointer to member of T" when T
6917 is not a class type. */
6918 if (complain & tf_error)
6919 error ("creating pointer to member of non-class type `%T'", r);
6920 return error_mark_node;
6922 if (TREE_CODE (type) == REFERENCE_TYPE)
6924 if (complain & tf_error)
6925 error ("creating pointer to member reference type `%T'", type);
6927 return error_mark_node;
6929 my_friendly_assert (TREE_CODE (type) != METHOD_TYPE, 20011231);
6930 if (TREE_CODE (type) == FUNCTION_TYPE)
6932 /* This is really a method type. The cv qualifiers of the
6933 this pointer should _not_ be determined by the cv
6934 qualifiers of the class type. They should be held
6935 somewhere in the FUNCTION_TYPE, but we don't do that at
6936 the moment. Consider
6937 typedef void (Func) () const;
6939 template <typename T1> void Foo (Func T1::*);
6942 tree method_type;
6944 method_type = build_method_type_directly (TYPE_MAIN_VARIANT (r),
6945 TREE_TYPE (type),
6946 TYPE_ARG_TYPES (type));
6947 return build_ptrmemfunc_type (build_pointer_type (method_type));
6949 else
6950 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
6951 TYPE_QUALS (t),
6952 complain);
6954 case FUNCTION_TYPE:
6955 case METHOD_TYPE:
6957 tree fntype;
6958 tree raises;
6960 fntype = tsubst_function_type (t, args, complain, in_decl);
6961 if (fntype == error_mark_node)
6962 return error_mark_node;
6964 /* Substitute the exception specification. */
6965 raises = TYPE_RAISES_EXCEPTIONS (t);
6966 if (raises)
6968 tree list = NULL_TREE;
6970 if (! TREE_VALUE (raises))
6971 list = raises;
6972 else
6973 for (; raises != NULL_TREE; raises = TREE_CHAIN (raises))
6975 tree spec = TREE_VALUE (raises);
6977 spec = tsubst (spec, args, complain, in_decl);
6978 if (spec == error_mark_node)
6979 return spec;
6980 list = add_exception_specifier (list, spec, complain);
6982 fntype = build_exception_variant (fntype, list);
6984 return fntype;
6986 case ARRAY_TYPE:
6988 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
6989 if (domain == error_mark_node)
6990 return error_mark_node;
6992 /* As an optimization, we avoid regenerating the array type if
6993 it will obviously be the same as T. */
6994 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
6995 return t;
6997 /* These checks should match the ones in grokdeclarator.
6999 [temp.deduct]
7001 The deduction may fail for any of the following reasons:
7003 -- Attempting to create an array with an element type that
7004 is void, a function type, or a reference type. */
7005 if (TREE_CODE (type) == VOID_TYPE
7006 || TREE_CODE (type) == FUNCTION_TYPE
7007 || TREE_CODE (type) == REFERENCE_TYPE)
7009 if (complain & tf_error)
7010 error ("creating array of `%T'", type);
7011 return error_mark_node;
7014 r = build_cplus_array_type (type, domain);
7015 return r;
7018 case PLUS_EXPR:
7019 case MINUS_EXPR:
7021 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
7022 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
7024 if (e1 == error_mark_node || e2 == error_mark_node)
7025 return error_mark_node;
7027 return fold (build (TREE_CODE (t), TREE_TYPE (t), e1, e2));
7030 case NEGATE_EXPR:
7031 case NOP_EXPR:
7033 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
7034 if (e == error_mark_node)
7035 return error_mark_node;
7037 return fold (build (TREE_CODE (t), TREE_TYPE (t), e));
7040 case TYPENAME_TYPE:
7042 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
7043 in_decl, /*entering_scope=*/1);
7044 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
7045 complain, in_decl);
7047 if (ctx == error_mark_node || f == error_mark_node)
7048 return error_mark_node;
7050 if (!IS_AGGR_TYPE (ctx))
7052 if (complain & tf_error)
7053 error ("`%T' is not a class, struct, or union type",
7054 ctx);
7055 return error_mark_node;
7057 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
7059 /* Normally, make_typename_type does not require that the CTX
7060 have complete type in order to allow things like:
7062 template <class T> struct S { typename S<T>::X Y; };
7064 But, such constructs have already been resolved by this
7065 point, so here CTX really should have complete type, unless
7066 it's a partial instantiation. */
7067 ctx = complete_type (ctx);
7068 if (!COMPLETE_TYPE_P (ctx))
7070 if (complain & tf_error)
7071 cxx_incomplete_type_error (NULL_TREE, ctx);
7072 return error_mark_node;
7076 f = make_typename_type (ctx, f,
7077 (complain & tf_error) | tf_keep_type_decl);
7078 if (f == error_mark_node)
7079 return f;
7080 if (TREE_CODE (f) == TYPE_DECL)
7082 complain |= tf_ignore_bad_quals;
7083 f = TREE_TYPE (f);
7086 return cp_build_qualified_type_real
7087 (f, cp_type_quals (f) | cp_type_quals (t), complain);
7090 case UNBOUND_CLASS_TEMPLATE:
7092 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
7093 in_decl, /*entering_scope=*/1);
7094 tree name = TYPE_IDENTIFIER (t);
7096 if (ctx == error_mark_node || name == error_mark_node)
7097 return error_mark_node;
7099 return make_unbound_class_template (ctx, name, complain);
7102 case INDIRECT_REF:
7104 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
7105 if (e == error_mark_node)
7106 return error_mark_node;
7107 return make_pointer_declarator (type, e);
7110 case ADDR_EXPR:
7112 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
7113 if (e == error_mark_node)
7114 return error_mark_node;
7115 return make_reference_declarator (type, e);
7118 case ARRAY_REF:
7120 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
7121 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl);
7122 if (e1 == error_mark_node || e2 == error_mark_node)
7123 return error_mark_node;
7125 return build_nt (ARRAY_REF, e1, e2);
7128 case CALL_EXPR:
7130 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
7131 tree e2 = (tsubst_call_declarator_parms
7132 (CALL_DECLARATOR_PARMS (t), args, complain, in_decl));
7133 tree e3 = tsubst (CALL_DECLARATOR_EXCEPTION_SPEC (t), args,
7134 complain, in_decl);
7136 if (e1 == error_mark_node || e2 == error_mark_node
7137 || e3 == error_mark_node)
7138 return error_mark_node;
7140 return make_call_declarator (e1, e2, CALL_DECLARATOR_QUALS (t), e3);
7143 case SCOPE_REF:
7145 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
7146 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
7147 if (e1 == error_mark_node || e2 == error_mark_node)
7148 return error_mark_node;
7150 return build_nt (TREE_CODE (t), e1, e2);
7153 case TYPEOF_TYPE:
7155 tree e1 = tsubst_expr (TYPE_FIELDS (t), args, complain, in_decl);
7156 if (e1 == error_mark_node)
7157 return error_mark_node;
7159 return cp_build_qualified_type_real (TREE_TYPE (e1),
7160 cp_type_quals (t)
7161 | cp_type_quals (TREE_TYPE (e1)),
7162 complain);
7165 default:
7166 sorry ("use of `%s' in template",
7167 tree_code_name [(int) TREE_CODE (t)]);
7168 return error_mark_node;
7172 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
7173 type of the expression on the left-hand side of the "." or "->"
7174 operator. */
7176 static tree
7177 tsubst_baselink (tree baselink, tree object_type,
7178 tree args, tsubst_flags_t complain, tree in_decl)
7180 tree name;
7181 tree qualifying_scope;
7182 tree fns;
7183 tree template_args = 0;
7184 bool template_id_p = false;
7186 /* A baselink indicates a function from a base class. The
7187 BASELINK_ACCESS_BINFO and BASELINK_BINFO are going to have
7188 non-dependent types; otherwise, the lookup could not have
7189 succeeded. However, they may indicate bases of the template
7190 class, rather than the instantiated class.
7192 In addition, lookups that were not ambiguous before may be
7193 ambiguous now. Therefore, we perform the lookup again. */
7194 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
7195 fns = BASELINK_FUNCTIONS (baselink);
7196 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
7198 template_id_p = true;
7199 template_args = TREE_OPERAND (fns, 1);
7200 fns = TREE_OPERAND (fns, 0);
7201 if (template_args)
7202 template_args = tsubst_template_args (template_args, args,
7203 complain, in_decl);
7205 name = DECL_NAME (get_first_fn (fns));
7206 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
7207 if (BASELINK_P (baselink) && template_id_p)
7208 BASELINK_FUNCTIONS (baselink)
7209 = build_nt (TEMPLATE_ID_EXPR,
7210 BASELINK_FUNCTIONS (baselink),
7211 template_args);
7212 if (!object_type)
7213 object_type = current_class_type;
7214 return adjust_result_of_qualified_name_lookup (baselink,
7215 qualifying_scope,
7216 object_type);
7219 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
7220 true if the qualified-id will be a postfix-expression in-and-of
7221 itself; false if more of the postfix-expression follows the
7222 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
7223 of "&". */
7225 static tree
7226 tsubst_qualified_id (tree qualified_id, tree args,
7227 tsubst_flags_t complain, tree in_decl,
7228 bool done, bool address_p)
7230 tree expr;
7231 tree scope;
7232 tree name;
7233 bool is_template;
7234 tree template_args;
7236 my_friendly_assert (TREE_CODE (qualified_id) == SCOPE_REF, 20030706);
7238 /* Figure out what name to look up. */
7239 name = TREE_OPERAND (qualified_id, 1);
7240 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
7242 is_template = true;
7243 template_args = TREE_OPERAND (name, 1);
7244 if (template_args)
7245 template_args = tsubst_template_args (template_args, args,
7246 complain, in_decl);
7247 name = TREE_OPERAND (name, 0);
7249 else
7251 is_template = false;
7252 template_args = NULL_TREE;
7255 /* Substitute into the qualifying scope. When there are no ARGS, we
7256 are just trying to simplify a non-dependent expression. In that
7257 case the qualifying scope may be dependent, and, in any case,
7258 substituting will not help. */
7259 scope = TREE_OPERAND (qualified_id, 0);
7260 if (args)
7262 scope = tsubst (scope, args, complain, in_decl);
7263 expr = tsubst_copy (name, args, complain, in_decl);
7265 else
7266 expr = name;
7268 my_friendly_assert (!dependent_type_p (scope), 20030729);
7270 if (!BASELINK_P (name) && !DECL_P (expr))
7272 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
7273 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
7274 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
7276 if (complain & tf_error)
7277 error ("`%E' names a type, but a non-type is expected",
7278 qualified_id);
7279 return error_mark_node;
7283 if (DECL_P (expr))
7284 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
7285 scope);
7287 /* Remember that there was a reference to this entity. */
7288 if (DECL_P (expr))
7290 mark_used (expr);
7291 if (!args && TREE_CODE (expr) == VAR_DECL)
7292 expr = DECL_INITIAL (expr);
7295 if (is_template)
7296 expr = lookup_template_function (expr, template_args);
7298 if (expr == error_mark_node && complain & tf_error)
7299 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1));
7300 else if (TYPE_P (scope))
7302 expr = (adjust_result_of_qualified_name_lookup
7303 (expr, scope, current_class_type));
7304 expr = finish_qualified_id_expr (scope, expr, done, address_p);
7307 return expr;
7310 /* Like tsubst, but deals with expressions. This function just replaces
7311 template parms; to finish processing the resultant expression, use
7312 tsubst_expr. */
7314 static tree
7315 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7317 enum tree_code code;
7318 tree r;
7320 if (t == NULL_TREE || t == error_mark_node)
7321 return t;
7323 code = TREE_CODE (t);
7325 switch (code)
7327 case PARM_DECL:
7328 r = retrieve_local_specialization (t);
7329 my_friendly_assert (r != NULL, 20020903);
7330 return r;
7332 case CONST_DECL:
7334 tree enum_type;
7335 tree v;
7337 if (DECL_TEMPLATE_PARM_P (t))
7338 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
7339 /* There is no need to substitute into namespace-scope
7340 enumerators. */
7341 if (DECL_NAMESPACE_SCOPE_P (t))
7342 return t;
7344 /* Unfortunately, we cannot just call lookup_name here.
7345 Consider:
7347 template <int I> int f() {
7348 enum E { a = I };
7349 struct S { void g() { E e = a; } };
7352 When we instantiate f<7>::S::g(), say, lookup_name is not
7353 clever enough to find f<7>::a. */
7354 enum_type
7355 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
7356 /*entering_scope=*/0);
7358 for (v = TYPE_VALUES (enum_type);
7359 v != NULL_TREE;
7360 v = TREE_CHAIN (v))
7361 if (TREE_PURPOSE (v) == DECL_NAME (t))
7362 return TREE_VALUE (v);
7364 /* We didn't find the name. That should never happen; if
7365 name-lookup found it during preliminary parsing, we
7366 should find it again here during instantiation. */
7367 abort ();
7369 return t;
7371 case FIELD_DECL:
7372 if (DECL_CONTEXT (t))
7374 tree ctx;
7376 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
7377 /*entering_scope=*/1);
7378 if (ctx != DECL_CONTEXT (t))
7379 return lookup_field (ctx, DECL_NAME (t), 0, false);
7381 return t;
7383 case VAR_DECL:
7384 case FUNCTION_DECL:
7385 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
7386 || local_variable_p (t))
7387 t = tsubst (t, args, complain, in_decl);
7388 mark_used (t);
7389 return t;
7391 case BASELINK:
7392 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
7394 case TEMPLATE_DECL:
7395 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
7396 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
7397 args, complain, in_decl);
7398 else if (is_member_template (t))
7399 return tsubst (t, args, complain, in_decl);
7400 else if (DECL_CLASS_SCOPE_P (t)
7401 && uses_template_parms (DECL_CONTEXT (t)))
7403 /* Template template argument like the following example need
7404 special treatment:
7406 template <template <class> class TT> struct C {};
7407 template <class T> struct D {
7408 template <class U> struct E {};
7409 C<E> c; // #1
7411 D<int> d; // #2
7413 We are processing the template argument `E' in #1 for
7414 the template instantiation #2. Originally, `E' is a
7415 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
7416 have to substitute this with one having context `D<int>'. */
7418 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
7419 return lookup_field (context, DECL_NAME(t), 0, false);
7421 else
7422 /* Ordinary template template argument. */
7423 return t;
7425 case CAST_EXPR:
7426 case REINTERPRET_CAST_EXPR:
7427 case CONST_CAST_EXPR:
7428 case STATIC_CAST_EXPR:
7429 case DYNAMIC_CAST_EXPR:
7430 case NOP_EXPR:
7431 return build1
7432 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
7433 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
7435 case INDIRECT_REF:
7436 case NEGATE_EXPR:
7437 case TRUTH_NOT_EXPR:
7438 case BIT_NOT_EXPR:
7439 case ADDR_EXPR:
7440 case CONVERT_EXPR: /* Unary + */
7441 case SIZEOF_EXPR:
7442 case ALIGNOF_EXPR:
7443 case ARROW_EXPR:
7444 case THROW_EXPR:
7445 case TYPEID_EXPR:
7446 case REALPART_EXPR:
7447 case IMAGPART_EXPR:
7448 return build1
7449 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
7450 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
7452 case COMPONENT_REF:
7454 tree object;
7455 tree name;
7457 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
7458 name = TREE_OPERAND (t, 1);
7459 if (TREE_CODE (name) == BIT_NOT_EXPR)
7461 name = tsubst_copy (TREE_OPERAND (name, 0), args,
7462 complain, in_decl);
7463 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
7465 else if (TREE_CODE (name) == SCOPE_REF
7466 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
7468 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
7469 complain, in_decl);
7470 name = TREE_OPERAND (name, 1);
7471 name = tsubst_copy (TREE_OPERAND (name, 0), args,
7472 complain, in_decl);
7473 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
7474 name = build_nt (SCOPE_REF, base, name);
7476 else if (TREE_CODE (name) == BASELINK)
7477 name = tsubst_baselink (name,
7478 non_reference (TREE_TYPE (object)),
7479 args, complain,
7480 in_decl);
7481 else
7482 name = tsubst_copy (name, args, complain, in_decl);
7483 return build_nt (COMPONENT_REF, object, name);
7486 case PLUS_EXPR:
7487 case MINUS_EXPR:
7488 case MULT_EXPR:
7489 case TRUNC_DIV_EXPR:
7490 case CEIL_DIV_EXPR:
7491 case FLOOR_DIV_EXPR:
7492 case ROUND_DIV_EXPR:
7493 case EXACT_DIV_EXPR:
7494 case BIT_AND_EXPR:
7495 case BIT_IOR_EXPR:
7496 case BIT_XOR_EXPR:
7497 case TRUNC_MOD_EXPR:
7498 case FLOOR_MOD_EXPR:
7499 case TRUTH_ANDIF_EXPR:
7500 case TRUTH_ORIF_EXPR:
7501 case TRUTH_AND_EXPR:
7502 case TRUTH_OR_EXPR:
7503 case RSHIFT_EXPR:
7504 case LSHIFT_EXPR:
7505 case RROTATE_EXPR:
7506 case LROTATE_EXPR:
7507 case EQ_EXPR:
7508 case NE_EXPR:
7509 case MAX_EXPR:
7510 case MIN_EXPR:
7511 case LE_EXPR:
7512 case GE_EXPR:
7513 case LT_EXPR:
7514 case GT_EXPR:
7515 case ARRAY_REF:
7516 case COMPOUND_EXPR:
7517 case SCOPE_REF:
7518 case DOTSTAR_EXPR:
7519 case MEMBER_REF:
7520 case PREDECREMENT_EXPR:
7521 case PREINCREMENT_EXPR:
7522 case POSTDECREMENT_EXPR:
7523 case POSTINCREMENT_EXPR:
7524 return build_nt
7525 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
7526 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
7528 case CALL_EXPR:
7529 return build_nt (code,
7530 tsubst_copy (TREE_OPERAND (t, 0), args,
7531 complain, in_decl),
7532 tsubst_copy (TREE_OPERAND (t, 1), args, complain,
7533 in_decl),
7534 NULL_TREE);
7536 case STMT_EXPR:
7537 /* This processing should really occur in tsubst_expr. However,
7538 tsubst_expr does not recurse into expressions, since it
7539 assumes that there aren't any statements inside them. So, we
7540 need to expand the STMT_EXPR here. */
7541 if (!processing_template_decl)
7543 tree stmt_expr = begin_stmt_expr ();
7545 tsubst_expr (STMT_EXPR_STMT (t), args,
7546 complain | tf_stmt_expr_cmpd, in_decl);
7547 return finish_stmt_expr (stmt_expr, false);
7550 return t;
7552 case COND_EXPR:
7553 case MODOP_EXPR:
7554 case PSEUDO_DTOR_EXPR:
7556 r = build_nt
7557 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
7558 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
7559 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
7560 return r;
7563 case NEW_EXPR:
7565 r = build_nt
7566 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
7567 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
7568 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
7569 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
7570 return r;
7573 case DELETE_EXPR:
7575 r = build_nt
7576 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
7577 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
7578 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
7579 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
7580 return r;
7583 case TEMPLATE_ID_EXPR:
7585 /* Substituted template arguments */
7586 tree fn = TREE_OPERAND (t, 0);
7587 tree targs = TREE_OPERAND (t, 1);
7589 fn = tsubst_copy (fn, args, complain, in_decl);
7590 if (targs)
7591 targs = tsubst_template_args (targs, args, complain, in_decl);
7593 return lookup_template_function (fn, targs);
7596 case TREE_LIST:
7598 tree purpose, value, chain;
7600 if (t == void_list_node)
7601 return t;
7603 purpose = TREE_PURPOSE (t);
7604 if (purpose)
7605 purpose = tsubst_copy (purpose, args, complain, in_decl);
7606 value = TREE_VALUE (t);
7607 if (value)
7608 value = tsubst_copy (value, args, complain, in_decl);
7609 chain = TREE_CHAIN (t);
7610 if (chain && chain != void_type_node)
7611 chain = tsubst_copy (chain, args, complain, in_decl);
7612 if (purpose == TREE_PURPOSE (t)
7613 && value == TREE_VALUE (t)
7614 && chain == TREE_CHAIN (t))
7615 return t;
7616 return tree_cons (purpose, value, chain);
7619 case RECORD_TYPE:
7620 case UNION_TYPE:
7621 case ENUMERAL_TYPE:
7622 case INTEGER_TYPE:
7623 case TEMPLATE_TYPE_PARM:
7624 case TEMPLATE_TEMPLATE_PARM:
7625 case BOUND_TEMPLATE_TEMPLATE_PARM:
7626 case TEMPLATE_PARM_INDEX:
7627 case POINTER_TYPE:
7628 case REFERENCE_TYPE:
7629 case OFFSET_TYPE:
7630 case FUNCTION_TYPE:
7631 case METHOD_TYPE:
7632 case ARRAY_TYPE:
7633 case TYPENAME_TYPE:
7634 case UNBOUND_CLASS_TEMPLATE:
7635 case TYPEOF_TYPE:
7636 case TYPE_DECL:
7637 return tsubst (t, args, complain, in_decl);
7639 case IDENTIFIER_NODE:
7640 if (IDENTIFIER_TYPENAME_P (t))
7642 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
7643 return mangle_conv_op_name_for_type (new_type);
7645 else
7646 return t;
7648 case CONSTRUCTOR:
7650 r = build_constructor
7651 (tsubst (TREE_TYPE (t), args, complain, in_decl),
7652 tsubst_copy (CONSTRUCTOR_ELTS (t), args, complain, in_decl));
7653 TREE_HAS_CONSTRUCTOR (r) = TREE_HAS_CONSTRUCTOR (t);
7654 return r;
7657 case VA_ARG_EXPR:
7658 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
7659 in_decl),
7660 tsubst (TREE_TYPE (t), args, complain, in_decl));
7662 default:
7663 return t;
7667 /* Like tsubst_copy for expressions, etc. but also does semantic
7668 processing. */
7670 static tree
7671 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7673 tree stmt, tmp;
7674 tsubst_flags_t stmt_expr
7675 = complain & (tf_stmt_expr_cmpd | tf_stmt_expr_body);
7677 complain ^= stmt_expr;
7678 if (t == NULL_TREE || t == error_mark_node)
7679 return t;
7681 if (processing_template_decl)
7682 return tsubst_copy (t, args, complain, in_decl);
7684 if (!STATEMENT_CODE_P (TREE_CODE (t)))
7685 return tsubst_copy_and_build (t, args, complain, in_decl,
7686 /*function_p=*/false);
7688 switch (TREE_CODE (t))
7690 case CTOR_INITIALIZER:
7691 prep_stmt (t);
7692 finish_mem_initializers (tsubst_initializer_list
7693 (TREE_OPERAND (t, 0), args));
7694 break;
7696 case RETURN_STMT:
7697 prep_stmt (t);
7698 finish_return_stmt (tsubst_expr (RETURN_STMT_EXPR (t),
7699 args, complain, in_decl));
7700 break;
7702 case EXPR_STMT:
7704 tree r;
7706 prep_stmt (t);
7708 r = tsubst_expr (EXPR_STMT_EXPR (t), args, complain, in_decl);
7709 if (stmt_expr & tf_stmt_expr_body && !TREE_CHAIN (t))
7710 finish_stmt_expr_expr (r);
7711 else
7712 finish_expr_stmt (r);
7713 break;
7716 case USING_STMT:
7717 prep_stmt (t);
7718 do_using_directive (tsubst_expr (USING_STMT_NAMESPACE (t),
7719 args, complain, in_decl));
7720 break;
7722 case DECL_STMT:
7724 tree decl;
7725 tree init;
7727 prep_stmt (t);
7728 decl = DECL_STMT_DECL (t);
7729 if (TREE_CODE (decl) == LABEL_DECL)
7730 finish_label_decl (DECL_NAME (decl));
7731 else if (TREE_CODE (decl) == USING_DECL)
7733 tree scope = DECL_INITIAL (decl);
7734 tree name = DECL_NAME (decl);
7735 tree decl;
7737 scope = tsubst_expr (scope, args, complain, in_decl);
7738 decl = lookup_qualified_name (scope, name,
7739 /*is_type_p=*/false,
7740 /*complain=*/false);
7741 if (decl == error_mark_node)
7742 qualified_name_lookup_error (scope, name);
7743 else
7744 do_local_using_decl (decl);
7746 else
7748 init = DECL_INITIAL (decl);
7749 decl = tsubst (decl, args, complain, in_decl);
7750 if (decl != error_mark_node)
7752 if (init)
7753 DECL_INITIAL (decl) = error_mark_node;
7754 /* By marking the declaration as instantiated, we avoid
7755 trying to instantiate it. Since instantiate_decl can't
7756 handle local variables, and since we've already done
7757 all that needs to be done, that's the right thing to
7758 do. */
7759 if (TREE_CODE (decl) == VAR_DECL)
7760 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
7761 if (TREE_CODE (decl) == VAR_DECL
7762 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
7763 /* Anonymous aggregates are a special case. */
7764 finish_anon_union (decl);
7765 else
7767 maybe_push_decl (decl);
7768 if (TREE_CODE (decl) == VAR_DECL
7769 && DECL_PRETTY_FUNCTION_P (decl))
7771 /* For __PRETTY_FUNCTION__ we have to adjust the
7772 initializer. */
7773 const char *const name
7774 = cxx_printable_name (current_function_decl, 2);
7775 init = cp_fname_init (name, &TREE_TYPE (decl));
7777 else
7778 init = tsubst_expr (init, args, complain, in_decl);
7779 cp_finish_decl (decl, init, NULL_TREE, 0);
7784 /* A DECL_STMT can also be used as an expression, in the condition
7785 clause of an if/for/while construct. If we aren't followed by
7786 another statement, return our decl. */
7787 if (TREE_CHAIN (t) == NULL_TREE)
7788 return decl;
7790 break;
7792 case FOR_STMT:
7794 prep_stmt (t);
7796 stmt = begin_for_stmt ();
7797 tsubst_expr (FOR_INIT_STMT (t), args, complain, in_decl);
7798 finish_for_init_stmt (stmt);
7799 finish_for_cond (tsubst_expr (FOR_COND (t),
7800 args, complain, in_decl),
7801 stmt);
7802 tmp = tsubst_expr (FOR_EXPR (t), args, complain, in_decl);
7803 finish_for_expr (tmp, stmt);
7804 tsubst_expr (FOR_BODY (t), args, complain, in_decl);
7805 finish_for_stmt (stmt);
7807 break;
7809 case WHILE_STMT:
7811 prep_stmt (t);
7812 stmt = begin_while_stmt ();
7813 finish_while_stmt_cond (tsubst_expr (WHILE_COND (t),
7814 args, complain, in_decl),
7815 stmt);
7816 tsubst_expr (WHILE_BODY (t), args, complain, in_decl);
7817 finish_while_stmt (stmt);
7819 break;
7821 case DO_STMT:
7823 prep_stmt (t);
7824 stmt = begin_do_stmt ();
7825 tsubst_expr (DO_BODY (t), args, complain, in_decl);
7826 finish_do_body (stmt);
7827 finish_do_stmt (tsubst_expr (DO_COND (t),
7828 args, complain, in_decl),
7829 stmt);
7831 break;
7833 case IF_STMT:
7835 prep_stmt (t);
7836 stmt = begin_if_stmt ();
7837 finish_if_stmt_cond (tsubst_expr (IF_COND (t),
7838 args, complain, in_decl),
7839 stmt);
7841 if (tmp = THEN_CLAUSE (t), tmp)
7843 tsubst_expr (tmp, args, complain, in_decl);
7844 finish_then_clause (stmt);
7847 if (tmp = ELSE_CLAUSE (t), tmp)
7849 begin_else_clause ();
7850 tsubst_expr (tmp, args, complain, in_decl);
7851 finish_else_clause (stmt);
7854 finish_if_stmt ();
7856 break;
7858 case COMPOUND_STMT:
7860 prep_stmt (t);
7861 if (COMPOUND_STMT_BODY_BLOCK (t))
7862 stmt = begin_function_body ();
7863 else
7864 stmt = begin_compound_stmt (COMPOUND_STMT_NO_SCOPE (t));
7866 tsubst_expr (COMPOUND_BODY (t), args,
7867 complain | ((stmt_expr & tf_stmt_expr_cmpd) << 1),
7868 in_decl);
7870 if (COMPOUND_STMT_BODY_BLOCK (t))
7871 finish_function_body (stmt);
7872 else
7873 finish_compound_stmt (stmt);
7875 break;
7877 case BREAK_STMT:
7878 prep_stmt (t);
7879 finish_break_stmt ();
7880 break;
7882 case CONTINUE_STMT:
7883 prep_stmt (t);
7884 finish_continue_stmt ();
7885 break;
7887 case SWITCH_STMT:
7889 tree val;
7891 prep_stmt (t);
7892 stmt = begin_switch_stmt ();
7893 val = tsubst_expr (SWITCH_COND (t), args, complain, in_decl);
7894 finish_switch_cond (val, stmt);
7895 tsubst_expr (SWITCH_BODY (t), args, complain, in_decl);
7896 finish_switch_stmt (stmt);
7898 break;
7900 case CASE_LABEL:
7901 prep_stmt (t);
7902 finish_case_label (tsubst_expr (CASE_LOW (t), args, complain, in_decl),
7903 tsubst_expr (CASE_HIGH (t), args, complain,
7904 in_decl));
7905 break;
7907 case LABEL_STMT:
7908 input_line = STMT_LINENO (t);
7909 finish_label_stmt (DECL_NAME (LABEL_STMT_LABEL (t)));
7910 break;
7912 case FILE_STMT:
7913 input_filename = FILE_STMT_FILENAME (t);
7914 add_stmt (build_nt (FILE_STMT, FILE_STMT_FILENAME_NODE (t)));
7915 break;
7917 case GOTO_STMT:
7918 prep_stmt (t);
7919 tmp = GOTO_DESTINATION (t);
7920 if (TREE_CODE (tmp) != LABEL_DECL)
7921 /* Computed goto's must be tsubst'd into. On the other hand,
7922 non-computed gotos must not be; the identifier in question
7923 will have no binding. */
7924 tmp = tsubst_expr (tmp, args, complain, in_decl);
7925 else
7926 tmp = DECL_NAME (tmp);
7927 finish_goto_stmt (tmp);
7928 break;
7930 case ASM_STMT:
7931 prep_stmt (t);
7932 tmp = finish_asm_stmt
7933 (ASM_CV_QUAL (t),
7934 tsubst_expr (ASM_STRING (t), args, complain, in_decl),
7935 tsubst_expr (ASM_OUTPUTS (t), args, complain, in_decl),
7936 tsubst_expr (ASM_INPUTS (t), args, complain, in_decl),
7937 tsubst_expr (ASM_CLOBBERS (t), args, complain, in_decl));
7938 ASM_INPUT_P (tmp) = ASM_INPUT_P (t);
7939 break;
7941 case TRY_BLOCK:
7942 prep_stmt (t);
7943 if (CLEANUP_P (t))
7945 stmt = begin_try_block ();
7946 tsubst_expr (TRY_STMTS (t), args, complain, in_decl);
7947 finish_cleanup_try_block (stmt);
7948 finish_cleanup (tsubst_expr (TRY_HANDLERS (t), args,
7949 complain, in_decl),
7950 stmt);
7952 else
7954 if (FN_TRY_BLOCK_P (t))
7955 stmt = begin_function_try_block ();
7956 else
7957 stmt = begin_try_block ();
7959 tsubst_expr (TRY_STMTS (t), args, complain, in_decl);
7961 if (FN_TRY_BLOCK_P (t))
7962 finish_function_try_block (stmt);
7963 else
7964 finish_try_block (stmt);
7966 tsubst_expr (TRY_HANDLERS (t), args, complain, in_decl);
7967 if (FN_TRY_BLOCK_P (t))
7968 finish_function_handler_sequence (stmt);
7969 else
7970 finish_handler_sequence (stmt);
7972 break;
7974 case HANDLER:
7976 tree decl;
7978 prep_stmt (t);
7979 stmt = begin_handler ();
7980 if (HANDLER_PARMS (t))
7982 decl = DECL_STMT_DECL (HANDLER_PARMS (t));
7983 decl = tsubst (decl, args, complain, in_decl);
7984 /* Prevent instantiate_decl from trying to instantiate
7985 this variable. We've already done all that needs to be
7986 done. */
7987 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
7989 else
7990 decl = NULL_TREE;
7991 finish_handler_parms (decl, stmt);
7992 tsubst_expr (HANDLER_BODY (t), args, complain, in_decl);
7993 finish_handler (stmt);
7995 break;
7997 case TAG_DEFN:
7998 prep_stmt (t);
7999 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
8000 break;
8002 default:
8003 abort ();
8006 return tsubst_expr (TREE_CHAIN (t), args, complain | stmt_expr, in_decl);
8009 /* T is a postfix-expression that is not being used in a function
8010 call. Return the substituted version of T. */
8012 static tree
8013 tsubst_non_call_postfix_expression (tree t, tree args,
8014 tsubst_flags_t complain,
8015 tree in_decl)
8017 if (TREE_CODE (t) == SCOPE_REF)
8018 t = tsubst_qualified_id (t, args, complain, in_decl,
8019 /*done=*/false, /*address_p=*/false);
8020 else
8021 t = tsubst_copy_and_build (t, args, complain, in_decl,
8022 /*function_p=*/false);
8024 return t;
8027 /* Like tsubst but deals with expressions and performs semantic
8028 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
8030 tree
8031 tsubst_copy_and_build (tree t,
8032 tree args,
8033 tsubst_flags_t complain,
8034 tree in_decl,
8035 bool function_p)
8037 #define RECUR(NODE) \
8038 tsubst_copy_and_build (NODE, args, complain, in_decl, /*function_p=*/false)
8040 tree op1;
8042 if (t == NULL_TREE || t == error_mark_node)
8043 return t;
8045 switch (TREE_CODE (t))
8047 case USING_DECL:
8048 t = DECL_NAME (t);
8049 /* Fallthrough. */
8050 case IDENTIFIER_NODE:
8052 tree decl;
8053 cp_id_kind idk;
8054 tree qualifying_class;
8055 bool non_constant_expression_p;
8056 const char *error_msg;
8058 if (IDENTIFIER_TYPENAME_P (t))
8060 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8061 t = mangle_conv_op_name_for_type (new_type);
8064 /* Look up the name. */
8065 decl = lookup_name (t, 0);
8067 /* By convention, expressions use ERROR_MARK_NODE to indicate
8068 failure, not NULL_TREE. */
8069 if (decl == NULL_TREE)
8070 decl = error_mark_node;
8072 decl = finish_id_expression (t, decl, NULL_TREE,
8073 &idk,
8074 &qualifying_class,
8075 /*constant_expression_p=*/false,
8076 /*allow_non_constant_expression_p=*/false,
8077 &non_constant_expression_p,
8078 &error_msg);
8079 if (error_msg)
8080 error (error_msg);
8081 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
8082 decl = unqualified_name_lookup_error (decl);
8083 return decl;
8086 case TEMPLATE_ID_EXPR:
8088 tree object;
8089 tree template = RECUR (TREE_OPERAND (t, 0));
8090 tree targs = TREE_OPERAND (t, 1);
8092 if (targs)
8093 targs = tsubst_template_args (targs, args, complain, in_decl);
8095 if (TREE_CODE (template) == COMPONENT_REF)
8097 object = TREE_OPERAND (template, 0);
8098 template = TREE_OPERAND (template, 1);
8100 else
8101 object = NULL_TREE;
8102 template = lookup_template_function (template, targs);
8104 if (object)
8105 return build (COMPONENT_REF, TREE_TYPE (template),
8106 object, template);
8107 else
8108 return template;
8111 case INDIRECT_REF:
8112 return build_x_indirect_ref (RECUR (TREE_OPERAND (t, 0)), "unary *");
8114 case CAST_EXPR:
8115 return build_functional_cast
8116 (tsubst (TREE_TYPE (t), args, complain, in_decl),
8117 RECUR (TREE_OPERAND (t, 0)));
8119 case REINTERPRET_CAST_EXPR:
8120 return build_reinterpret_cast
8121 (tsubst (TREE_TYPE (t), args, complain, in_decl),
8122 RECUR (TREE_OPERAND (t, 0)));
8124 case CONST_CAST_EXPR:
8125 return build_const_cast
8126 (tsubst (TREE_TYPE (t), args, complain, in_decl),
8127 RECUR (TREE_OPERAND (t, 0)));
8129 case DYNAMIC_CAST_EXPR:
8130 return build_dynamic_cast
8131 (tsubst (TREE_TYPE (t), args, complain, in_decl),
8132 RECUR (TREE_OPERAND (t, 0)));
8134 case STATIC_CAST_EXPR:
8135 return build_static_cast
8136 (tsubst (TREE_TYPE (t), args, complain, in_decl),
8137 RECUR (TREE_OPERAND (t, 0)));
8139 case POSTDECREMENT_EXPR:
8140 case POSTINCREMENT_EXPR:
8141 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
8142 args, complain, in_decl);
8143 return build_x_unary_op (TREE_CODE (t), op1);
8145 case PREDECREMENT_EXPR:
8146 case PREINCREMENT_EXPR:
8147 case NEGATE_EXPR:
8148 case BIT_NOT_EXPR:
8149 case ABS_EXPR:
8150 case TRUTH_NOT_EXPR:
8151 case CONVERT_EXPR: /* Unary + */
8152 case REALPART_EXPR:
8153 case IMAGPART_EXPR:
8154 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)));
8156 case ADDR_EXPR:
8157 op1 = TREE_OPERAND (t, 0);
8158 if (TREE_CODE (op1) == SCOPE_REF)
8159 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
8160 /*done=*/true, /*address_p=*/true);
8161 else
8162 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
8163 in_decl);
8164 if (TREE_CODE (op1) == LABEL_DECL)
8165 return finish_label_address_expr (DECL_NAME (op1));
8166 return build_x_unary_op (ADDR_EXPR, op1);
8168 case PLUS_EXPR:
8169 case MINUS_EXPR:
8170 case MULT_EXPR:
8171 case TRUNC_DIV_EXPR:
8172 case CEIL_DIV_EXPR:
8173 case FLOOR_DIV_EXPR:
8174 case ROUND_DIV_EXPR:
8175 case EXACT_DIV_EXPR:
8176 case BIT_AND_EXPR:
8177 case BIT_IOR_EXPR:
8178 case BIT_XOR_EXPR:
8179 case TRUNC_MOD_EXPR:
8180 case FLOOR_MOD_EXPR:
8181 case TRUTH_ANDIF_EXPR:
8182 case TRUTH_ORIF_EXPR:
8183 case TRUTH_AND_EXPR:
8184 case TRUTH_OR_EXPR:
8185 case RSHIFT_EXPR:
8186 case LSHIFT_EXPR:
8187 case RROTATE_EXPR:
8188 case LROTATE_EXPR:
8189 case EQ_EXPR:
8190 case NE_EXPR:
8191 case MAX_EXPR:
8192 case MIN_EXPR:
8193 case LE_EXPR:
8194 case GE_EXPR:
8195 case LT_EXPR:
8196 case GT_EXPR:
8197 case MEMBER_REF:
8198 case DOTSTAR_EXPR:
8199 return build_x_binary_op
8200 (TREE_CODE (t),
8201 RECUR (TREE_OPERAND (t, 0)),
8202 RECUR (TREE_OPERAND (t, 1)));
8204 case SCOPE_REF:
8205 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
8206 /*address_p=*/false);
8208 case ARRAY_REF:
8209 if (tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl)
8210 == NULL_TREE)
8211 /* new-type-id */
8212 return build_nt (ARRAY_REF, NULL_TREE, RECUR (TREE_OPERAND (t, 1)));
8214 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
8215 args, complain, in_decl);
8216 /* Remember that there was a reference to this entity. */
8217 if (DECL_P (op1))
8218 mark_used (op1);
8219 return grok_array_decl (op1, RECUR (TREE_OPERAND (t, 1)));
8221 case SIZEOF_EXPR:
8222 case ALIGNOF_EXPR:
8223 op1 = TREE_OPERAND (t, 0);
8224 if (!args)
8226 /* When there are no ARGS, we are trying to evaluate a
8227 non-dependent expression from the parser. Trying to do
8228 the substitutions may not work. */
8229 if (!TYPE_P (op1))
8230 op1 = TREE_TYPE (op1);
8232 else
8234 ++skip_evaluation;
8235 op1 = RECUR (op1);
8236 --skip_evaluation;
8238 if (TYPE_P (op1))
8239 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t), true);
8240 else
8241 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t));
8243 case MODOP_EXPR:
8244 return build_x_modify_expr
8245 (RECUR (TREE_OPERAND (t, 0)),
8246 TREE_CODE (TREE_OPERAND (t, 1)),
8247 RECUR (TREE_OPERAND (t, 2)));
8249 case ARROW_EXPR:
8250 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
8251 args, complain, in_decl);
8252 /* Remember that there was a reference to this entity. */
8253 if (DECL_P (op1))
8254 mark_used (op1);
8255 return build_x_arrow (op1);
8257 case NEW_EXPR:
8258 return build_new
8259 (RECUR (TREE_OPERAND (t, 0)),
8260 RECUR (TREE_OPERAND (t, 1)),
8261 RECUR (TREE_OPERAND (t, 2)),
8262 NEW_EXPR_USE_GLOBAL (t));
8264 case DELETE_EXPR:
8265 return delete_sanity
8266 (RECUR (TREE_OPERAND (t, 0)),
8267 RECUR (TREE_OPERAND (t, 1)),
8268 DELETE_EXPR_USE_VEC (t),
8269 DELETE_EXPR_USE_GLOBAL (t));
8271 case COMPOUND_EXPR:
8272 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
8273 RECUR (TREE_OPERAND (t, 1)));
8275 case CALL_EXPR:
8277 tree function;
8278 tree call_args;
8279 bool qualified_p;
8280 bool koenig_p;
8282 function = TREE_OPERAND (t, 0);
8283 /* When we parsed the expression, we determined whether or
8284 not Koenig lookup should be performed. */
8285 koenig_p = KOENIG_LOOKUP_P (t);
8286 if (TREE_CODE (function) == SCOPE_REF)
8288 qualified_p = true;
8289 function = tsubst_qualified_id (function, args, complain, in_decl,
8290 /*done=*/false,
8291 /*address_p=*/false);
8293 else
8295 qualified_p = (TREE_CODE (function) == COMPONENT_REF
8296 && (TREE_CODE (TREE_OPERAND (function, 1))
8297 == SCOPE_REF));
8298 function = tsubst_copy_and_build (function, args, complain,
8299 in_decl,
8300 !qualified_p);
8301 if (BASELINK_P (function))
8302 qualified_p = true;
8305 call_args = RECUR (TREE_OPERAND (t, 1));
8307 if (koenig_p
8308 && (is_overloaded_fn (function)
8309 || DECL_P (function)
8310 || TREE_CODE (function) == IDENTIFIER_NODE))
8311 function = perform_koenig_lookup (function, call_args);
8313 if (TREE_CODE (function) == IDENTIFIER_NODE)
8315 unqualified_name_lookup_error (function);
8316 return error_mark_node;
8319 /* Remember that there was a reference to this entity. */
8320 if (DECL_P (function))
8321 mark_used (function);
8323 function = convert_from_reference (function);
8325 if (TREE_CODE (function) == OFFSET_REF)
8326 return build_offset_ref_call_from_tree (function, call_args);
8327 if (TREE_CODE (function) == COMPONENT_REF)
8328 return (build_new_method_call
8329 (TREE_OPERAND (function, 0),
8330 TREE_OPERAND (function, 1),
8331 call_args, NULL_TREE,
8332 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL));
8333 return finish_call_expr (function, call_args,
8334 /*disallow_virtual=*/qualified_p,
8335 koenig_p);
8338 case COND_EXPR:
8339 return build_x_conditional_expr
8340 (RECUR (TREE_OPERAND (t, 0)),
8341 RECUR (TREE_OPERAND (t, 1)),
8342 RECUR (TREE_OPERAND (t, 2)));
8344 case PSEUDO_DTOR_EXPR:
8345 return finish_pseudo_destructor_expr
8346 (RECUR (TREE_OPERAND (t, 0)),
8347 RECUR (TREE_OPERAND (t, 1)),
8348 RECUR (TREE_OPERAND (t, 2)));
8350 case TREE_LIST:
8352 tree purpose, value, chain;
8354 if (t == void_list_node)
8355 return t;
8357 purpose = TREE_PURPOSE (t);
8358 if (purpose)
8359 purpose = RECUR (purpose);
8360 value = TREE_VALUE (t);
8361 if (value)
8362 value = RECUR (value);
8363 chain = TREE_CHAIN (t);
8364 if (chain && chain != void_type_node)
8365 chain = RECUR (chain);
8366 if (purpose == TREE_PURPOSE (t)
8367 && value == TREE_VALUE (t)
8368 && chain == TREE_CHAIN (t))
8369 return t;
8370 return tree_cons (purpose, value, chain);
8373 case COMPONENT_REF:
8375 tree object;
8376 tree member;
8378 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
8379 args, complain, in_decl);
8380 /* Remember that there was a reference to this entity. */
8381 if (DECL_P (object))
8382 mark_used (object);
8384 member = TREE_OPERAND (t, 1);
8385 if (BASELINK_P (member))
8386 member = tsubst_baselink (member,
8387 non_reference (TREE_TYPE (object)),
8388 args, complain, in_decl);
8389 else
8390 member = tsubst_copy (member, args, complain, in_decl);
8392 if (!CLASS_TYPE_P (TREE_TYPE (object)))
8394 if (TREE_CODE (member) == BIT_NOT_EXPR)
8395 return finish_pseudo_destructor_expr (object,
8396 NULL_TREE,
8397 TREE_TYPE (object));
8398 else if (TREE_CODE (member) == SCOPE_REF
8399 && (TREE_CODE (TREE_OPERAND (member, 1)) == BIT_NOT_EXPR))
8400 return finish_pseudo_destructor_expr (object,
8401 object,
8402 TREE_TYPE (object));
8404 else if (TREE_CODE (member) == SCOPE_REF
8405 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
8407 tree tmpl;
8408 tree args;
8410 /* Lookup the template functions now that we know what the
8411 scope is. */
8412 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
8413 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
8414 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
8415 /*is_type_p=*/false,
8416 /*complain=*/false);
8417 if (BASELINK_P (member))
8418 BASELINK_FUNCTIONS (member)
8419 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
8420 args);
8421 else
8423 qualified_name_lookup_error (TREE_TYPE (object), tmpl);
8424 return error_mark_node;
8427 else if (TREE_CODE (member) == FIELD_DECL)
8428 return finish_non_static_data_member (member, object, NULL_TREE);
8430 return finish_class_member_access_expr (object, member);
8433 case THROW_EXPR:
8434 return build_throw
8435 (RECUR (TREE_OPERAND (t, 0)));
8437 case CONSTRUCTOR:
8439 tree r;
8440 tree elts;
8441 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8442 bool purpose_p;
8444 /* digest_init will do the wrong thing if we let it. */
8445 if (type && TYPE_PTRMEMFUNC_P (type))
8446 return t;
8448 r = NULL_TREE;
8449 /* We do not want to process the purpose of aggregate
8450 initializers as they are identifier nodes which will be
8451 looked up by digest_init. */
8452 purpose_p = !(type && IS_AGGR_TYPE (type));
8453 for (elts = CONSTRUCTOR_ELTS (t);
8454 elts;
8455 elts = TREE_CHAIN (elts))
8457 tree purpose = TREE_PURPOSE (elts);
8458 tree value = TREE_VALUE (elts);
8460 if (purpose && purpose_p)
8461 purpose = RECUR (purpose);
8462 value = RECUR (value);
8463 r = tree_cons (purpose, value, r);
8466 r = build_constructor (NULL_TREE, nreverse (r));
8467 TREE_HAS_CONSTRUCTOR (r) = TREE_HAS_CONSTRUCTOR (t);
8469 if (type)
8470 return digest_init (type, r, 0);
8471 return r;
8474 case TYPEID_EXPR:
8476 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
8477 if (TYPE_P (operand_0))
8478 return get_typeid (operand_0);
8479 return build_typeid (operand_0);
8482 case PARM_DECL:
8483 return convert_from_reference (tsubst_copy (t, args, complain, in_decl));
8485 case VAR_DECL:
8486 if (args)
8487 t = tsubst_copy (t, args, complain, in_decl);
8488 else
8489 /* If there are no ARGS, then we are evaluating a
8490 non-dependent expression. If the expression is
8491 non-dependent, the variable must be a constant. */
8492 t = DECL_INITIAL (t);
8493 return convert_from_reference (t);
8495 case VA_ARG_EXPR:
8496 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
8497 tsubst_copy (TREE_TYPE (t), args, complain,
8498 in_decl));
8500 default:
8501 return tsubst_copy (t, args, complain, in_decl);
8504 #undef RECUR
8507 /* Verify that the instantiated ARGS are valid. For type arguments,
8508 make sure that the type's linkage is ok. For non-type arguments,
8509 make sure they are constants if they are integral or enumerations.
8510 Emit an error under control of COMPLAIN, and return TRUE on error. */
8512 static bool
8513 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
8515 int ix, len = DECL_NTPARMS (tmpl);
8516 bool result = false;
8518 for (ix = 0; ix != len; ix++)
8520 tree t = TREE_VEC_ELT (args, ix);
8522 if (TYPE_P (t))
8524 /* [basic.link]: A name with no linkage (notably, the name
8525 of a class or enumeration declared in a local scope)
8526 shall not be used to declare an entity with linkage.
8527 This implies that names with no linkage cannot be used as
8528 template arguments. */
8529 tree nt = no_linkage_check (t);
8531 if (nt)
8533 if (!(complain & tf_error))
8534 /*OK*/;
8535 else if (TYPE_ANONYMOUS_P (nt))
8536 error ("`%T' uses anonymous type", t);
8537 else
8538 error ("`%T' uses local type `%T'", t, nt);
8539 result = true;
8541 /* In order to avoid all sorts of complications, we do not
8542 allow variably-modified types as template arguments. */
8543 else if (variably_modified_type_p (t))
8545 if (complain & tf_error)
8546 error ("`%T' is a variably modified type", t);
8547 result = true;
8550 /* A non-type argument of integral or enumerated type must be a
8551 constant. */
8552 else if (TREE_TYPE (t)
8553 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
8554 && !TREE_CONSTANT (t))
8556 if (complain & tf_error)
8557 error ("integral expression `%E' is not constant", t);
8558 result = true;
8561 if (result && complain & tf_error)
8562 error (" trying to instantiate `%D'", tmpl);
8563 return result;
8566 /* Instantiate the indicated variable or function template TMPL with
8567 the template arguments in TARG_PTR. */
8569 tree
8570 instantiate_template (tree tmpl, tree targ_ptr, tsubst_flags_t complain)
8572 tree fndecl;
8573 tree gen_tmpl;
8574 tree spec;
8576 if (tmpl == error_mark_node)
8577 return error_mark_node;
8579 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 283);
8581 /* If this function is a clone, handle it specially. */
8582 if (DECL_CLONED_FUNCTION_P (tmpl))
8584 tree spec = instantiate_template (DECL_CLONED_FUNCTION (tmpl), targ_ptr,
8585 complain);
8586 tree clone;
8588 /* Look for the clone. */
8589 for (clone = TREE_CHAIN (spec);
8590 clone && DECL_CLONED_FUNCTION_P (clone);
8591 clone = TREE_CHAIN (clone))
8592 if (DECL_NAME (clone) == DECL_NAME (tmpl))
8593 return clone;
8594 /* We should always have found the clone by now. */
8595 abort ();
8596 return NULL_TREE;
8599 /* Check to see if we already have this specialization. */
8600 spec = retrieve_specialization (tmpl, targ_ptr);
8601 if (spec != NULL_TREE)
8602 return spec;
8604 gen_tmpl = most_general_template (tmpl);
8605 if (tmpl != gen_tmpl)
8607 /* The TMPL is a partial instantiation. To get a full set of
8608 arguments we must add the arguments used to perform the
8609 partial instantiation. */
8610 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
8611 targ_ptr);
8613 /* Check to see if we already have this specialization. */
8614 spec = retrieve_specialization (gen_tmpl, targ_ptr);
8615 if (spec != NULL_TREE)
8616 return spec;
8619 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
8620 complain))
8621 return error_mark_node;
8623 /* We are building a FUNCTION_DECL, during which the access of its
8624 parameters and return types have to be checked. However this
8625 FUNCTION_DECL which is the desired context for access checking
8626 is not built yet. We solve this chicken-and-egg problem by
8627 deferring all checks until we have the FUNCTION_DECL. */
8628 push_deferring_access_checks (dk_deferred);
8630 /* substitute template parameters */
8631 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
8632 targ_ptr, complain, gen_tmpl);
8634 /* Now we know the specialization, compute access previously
8635 deferred. */
8636 push_access_scope (fndecl);
8637 perform_deferred_access_checks ();
8638 pop_access_scope (fndecl);
8639 pop_deferring_access_checks ();
8641 /* The DECL_TI_TEMPLATE should always be the immediate parent
8642 template, not the most general template. */
8643 DECL_TI_TEMPLATE (fndecl) = tmpl;
8645 if (flag_external_templates)
8646 add_pending_template (fndecl);
8648 /* If we've just instantiated the main entry point for a function,
8649 instantiate all the alternate entry points as well. We do this
8650 by cloning the instantiation of the main entry point, not by
8651 instantiating the template clones. */
8652 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
8653 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
8655 return fndecl;
8658 /* The FN is a TEMPLATE_DECL for a function. The ARGS are the
8659 arguments that are being used when calling it. TARGS is a vector
8660 into which the deduced template arguments are placed.
8662 Return zero for success, 2 for an incomplete match that doesn't resolve
8663 all the types, and 1 for complete failure. An error message will be
8664 printed only for an incomplete match.
8666 If FN is a conversion operator, or we are trying to produce a specific
8667 specialization, RETURN_TYPE is the return type desired.
8669 The EXPLICIT_TARGS are explicit template arguments provided via a
8670 template-id.
8672 The parameter STRICT is one of:
8674 DEDUCE_CALL:
8675 We are deducing arguments for a function call, as in
8676 [temp.deduct.call].
8678 DEDUCE_CONV:
8679 We are deducing arguments for a conversion function, as in
8680 [temp.deduct.conv].
8682 DEDUCE_EXACT:
8683 We are deducing arguments when doing an explicit instantiation
8684 as in [temp.explicit], when determining an explicit specialization
8685 as in [temp.expl.spec], or when taking the address of a function
8686 template, as in [temp.deduct.funcaddr].
8688 DEDUCE_ORDER:
8689 We are deducing arguments when calculating the partial
8690 ordering between specializations of function or class
8691 templates, as in [temp.func.order] and [temp.class.order].
8693 LEN is the number of parms to consider before returning success, or -1
8694 for all. This is used in partial ordering to avoid comparing parms for
8695 which no actual argument was passed, since they are not considered in
8696 overload resolution (and are explicitly excluded from consideration in
8697 partial ordering in [temp.func.order]/6). */
8700 fn_type_unification (tree fn,
8701 tree explicit_targs,
8702 tree targs,
8703 tree args,
8704 tree return_type,
8705 unification_kind_t strict,
8706 int len)
8708 tree parms;
8709 tree fntype;
8710 int result;
8712 my_friendly_assert (TREE_CODE (fn) == TEMPLATE_DECL, 0);
8714 fntype = TREE_TYPE (fn);
8715 if (explicit_targs)
8717 /* [temp.deduct]
8719 The specified template arguments must match the template
8720 parameters in kind (i.e., type, nontype, template), and there
8721 must not be more arguments than there are parameters;
8722 otherwise type deduction fails.
8724 Nontype arguments must match the types of the corresponding
8725 nontype template parameters, or must be convertible to the
8726 types of the corresponding nontype parameters as specified in
8727 _temp.arg.nontype_, otherwise type deduction fails.
8729 All references in the function type of the function template
8730 to the corresponding template parameters are replaced by the
8731 specified template argument values. If a substitution in a
8732 template parameter or in the function type of the function
8733 template results in an invalid type, type deduction fails. */
8734 int i;
8735 tree converted_args;
8736 bool incomplete;
8738 converted_args
8739 = (coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
8740 explicit_targs, NULL_TREE, tf_none,
8741 /*require_all_arguments=*/0));
8742 if (converted_args == error_mark_node)
8743 return 1;
8745 /* Substitute the explicit args into the function type. This is
8746 necessary so that, for instance, explicitly declared function
8747 arguments can match null pointed constants. If we were given
8748 an incomplete set of explicit args, we must not do semantic
8749 processing during substitution as we could create partial
8750 instantiations. */
8751 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
8752 processing_template_decl += incomplete;
8753 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
8754 processing_template_decl -= incomplete;
8756 if (fntype == error_mark_node)
8757 return 1;
8759 /* Place the explicitly specified arguments in TARGS. */
8760 for (i = NUM_TMPL_ARGS (converted_args); i--;)
8761 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
8764 parms = TYPE_ARG_TYPES (fntype);
8765 /* Never do unification on the 'this' parameter. */
8766 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
8767 parms = TREE_CHAIN (parms);
8769 if (return_type)
8771 /* We've been given a return type to match, prepend it. */
8772 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
8773 args = tree_cons (NULL_TREE, return_type, args);
8774 if (len >= 0)
8775 ++len;
8778 /* We allow incomplete unification without an error message here
8779 because the standard doesn't seem to explicitly prohibit it. Our
8780 callers must be ready to deal with unification failures in any
8781 event. */
8782 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
8783 targs, parms, args, /*subr=*/0,
8784 strict, /*allow_incomplete*/1, len);
8786 if (result == 0)
8787 /* All is well so far. Now, check:
8789 [temp.deduct]
8791 When all template arguments have been deduced, all uses of
8792 template parameters in nondeduced contexts are replaced with
8793 the corresponding deduced argument values. If the
8794 substitution results in an invalid type, as described above,
8795 type deduction fails. */
8796 if (tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE)
8797 == error_mark_node)
8798 return 1;
8800 return result;
8803 /* Adjust types before performing type deduction, as described in
8804 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
8805 sections are symmetric. PARM is the type of a function parameter
8806 or the return type of the conversion function. ARG is the type of
8807 the argument passed to the call, or the type of the value
8808 initialized with the result of the conversion function. */
8810 static int
8811 maybe_adjust_types_for_deduction (unification_kind_t strict,
8812 tree* parm,
8813 tree* arg)
8815 int result = 0;
8817 switch (strict)
8819 case DEDUCE_CALL:
8820 break;
8822 case DEDUCE_CONV:
8824 /* Swap PARM and ARG throughout the remainder of this
8825 function; the handling is precisely symmetric since PARM
8826 will initialize ARG rather than vice versa. */
8827 tree* temp = parm;
8828 parm = arg;
8829 arg = temp;
8830 break;
8833 case DEDUCE_EXACT:
8834 /* There is nothing to do in this case. */
8835 return 0;
8837 case DEDUCE_ORDER:
8838 /* DR 214. [temp.func.order] is underspecified, and leads to no
8839 ordering between things like `T *' and `T const &' for `U *'.
8840 The former has T=U and the latter T=U*. The former looks more
8841 specialized and John Spicer considers it well-formed (the EDG
8842 compiler accepts it).
8844 John also confirms that deduction should proceed as in a function
8845 call. Which implies the usual ARG and PARM conversions as DEDUCE_CALL.
8846 However, in ordering, ARG can have REFERENCE_TYPE, but no argument
8847 to an actual call can have such a type.
8849 If both ARG and PARM are REFERENCE_TYPE, we change neither.
8850 If only ARG is a REFERENCE_TYPE, we look through that and then
8851 proceed as with DEDUCE_CALL (which could further convert it). */
8852 if (TREE_CODE (*arg) == REFERENCE_TYPE)
8854 if (TREE_CODE (*parm) == REFERENCE_TYPE)
8855 return 0;
8856 *arg = TREE_TYPE (*arg);
8858 break;
8859 default:
8860 abort ();
8863 if (TREE_CODE (*parm) != REFERENCE_TYPE)
8865 /* [temp.deduct.call]
8867 If P is not a reference type:
8869 --If A is an array type, the pointer type produced by the
8870 array-to-pointer standard conversion (_conv.array_) is
8871 used in place of A for type deduction; otherwise,
8873 --If A is a function type, the pointer type produced by
8874 the function-to-pointer standard conversion
8875 (_conv.func_) is used in place of A for type deduction;
8876 otherwise,
8878 --If A is a cv-qualified type, the top level
8879 cv-qualifiers of A's type are ignored for type
8880 deduction. */
8881 if (TREE_CODE (*arg) == ARRAY_TYPE)
8882 *arg = build_pointer_type (TREE_TYPE (*arg));
8883 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
8884 *arg = build_pointer_type (*arg);
8885 else
8886 *arg = TYPE_MAIN_VARIANT (*arg);
8889 /* [temp.deduct.call]
8891 If P is a cv-qualified type, the top level cv-qualifiers
8892 of P's type are ignored for type deduction. If P is a
8893 reference type, the type referred to by P is used for
8894 type deduction. */
8895 *parm = TYPE_MAIN_VARIANT (*parm);
8896 if (TREE_CODE (*parm) == REFERENCE_TYPE)
8898 *parm = TREE_TYPE (*parm);
8899 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
8902 /* DR 322. For conversion deduction, remove a reference type on parm
8903 too (which has been swapped into ARG). */
8904 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
8905 *arg = TREE_TYPE (*arg);
8907 return result;
8910 /* Most parms like fn_type_unification.
8912 If SUBR is 1, we're being called recursively (to unify the
8913 arguments of a function or method parameter of a function
8914 template). */
8916 static int
8917 type_unification_real (tree tparms,
8918 tree targs,
8919 tree xparms,
8920 tree xargs,
8921 int subr,
8922 unification_kind_t strict,
8923 int allow_incomplete,
8924 int xlen)
8926 tree parm, arg;
8927 int i;
8928 int ntparms = TREE_VEC_LENGTH (tparms);
8929 int sub_strict;
8930 int saw_undeduced = 0;
8931 tree parms, args;
8932 int len;
8934 my_friendly_assert (TREE_CODE (tparms) == TREE_VEC, 289);
8935 my_friendly_assert (xparms == NULL_TREE
8936 || TREE_CODE (xparms) == TREE_LIST, 290);
8937 my_friendly_assert (!xargs || TREE_CODE (xargs) == TREE_LIST, 291);
8938 my_friendly_assert (ntparms > 0, 292);
8940 switch (strict)
8942 case DEDUCE_CALL:
8943 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
8944 | UNIFY_ALLOW_DERIVED);
8945 break;
8947 case DEDUCE_CONV:
8948 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
8949 break;
8951 case DEDUCE_EXACT:
8952 sub_strict = UNIFY_ALLOW_NONE;
8953 break;
8955 case DEDUCE_ORDER:
8956 sub_strict = UNIFY_ALLOW_NONE;
8957 break;
8959 default:
8960 abort ();
8963 if (xlen == 0)
8964 return 0;
8966 again:
8967 parms = xparms;
8968 args = xargs;
8969 len = xlen;
8971 while (parms
8972 && parms != void_list_node
8973 && args
8974 && args != void_list_node)
8976 parm = TREE_VALUE (parms);
8977 parms = TREE_CHAIN (parms);
8978 arg = TREE_VALUE (args);
8979 args = TREE_CHAIN (args);
8981 if (arg == error_mark_node)
8982 return 1;
8983 if (arg == unknown_type_node)
8984 /* We can't deduce anything from this, but we might get all the
8985 template args from other function args. */
8986 continue;
8988 /* Conversions will be performed on a function argument that
8989 corresponds with a function parameter that contains only
8990 non-deducible template parameters and explicitly specified
8991 template parameters. */
8992 if (! uses_template_parms (parm))
8994 tree type;
8996 if (!TYPE_P (arg))
8997 type = TREE_TYPE (arg);
8998 else
9000 type = arg;
9001 arg = NULL_TREE;
9004 if (strict == DEDUCE_EXACT || strict == DEDUCE_ORDER)
9006 if (same_type_p (parm, type))
9007 continue;
9009 else
9010 /* It might work; we shouldn't check now, because we might
9011 get into infinite recursion. Overload resolution will
9012 handle it. */
9013 continue;
9015 return 1;
9018 if (!TYPE_P (arg))
9020 my_friendly_assert (TREE_TYPE (arg) != NULL_TREE, 293);
9021 if (type_unknown_p (arg))
9023 /* [temp.deduct.type] A template-argument can be deduced from
9024 a pointer to function or pointer to member function
9025 argument if the set of overloaded functions does not
9026 contain function templates and at most one of a set of
9027 overloaded functions provides a unique match. */
9029 if (resolve_overloaded_unification
9030 (tparms, targs, parm, arg, strict, sub_strict)
9031 != 0)
9032 return 1;
9033 continue;
9035 arg = TREE_TYPE (arg);
9036 if (arg == error_mark_node)
9037 return 1;
9041 int arg_strict = sub_strict;
9043 if (!subr)
9044 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg);
9046 if (unify (tparms, targs, parm, arg, arg_strict))
9047 return 1;
9050 /* Are we done with the interesting parms? */
9051 if (--len == 0)
9052 goto done;
9054 /* Fail if we've reached the end of the parm list, and more args
9055 are present, and the parm list isn't variadic. */
9056 if (args && args != void_list_node && parms == void_list_node)
9057 return 1;
9058 /* Fail if parms are left and they don't have default values. */
9059 if (parms
9060 && parms != void_list_node
9061 && TREE_PURPOSE (parms) == NULL_TREE)
9062 return 1;
9064 done:
9065 if (!subr)
9066 for (i = 0; i < ntparms; i++)
9067 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
9069 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
9071 /* If this is an undeduced nontype parameter that depends on
9072 a type parameter, try another pass; its type may have been
9073 deduced from a later argument than the one from which
9074 this parameter can be deduced. */
9075 if (TREE_CODE (tparm) == PARM_DECL
9076 && uses_template_parms (TREE_TYPE (tparm))
9077 && !saw_undeduced++)
9078 goto again;
9080 if (!allow_incomplete)
9081 error ("incomplete type unification");
9082 return 2;
9084 return 0;
9087 /* Subroutine of type_unification_real. Args are like the variables at the
9088 call site. ARG is an overloaded function (or template-id); we try
9089 deducing template args from each of the overloads, and if only one
9090 succeeds, we go with that. Modifies TARGS and returns 0 on success. */
9092 static int
9093 resolve_overloaded_unification (tree tparms,
9094 tree targs,
9095 tree parm,
9096 tree arg,
9097 unification_kind_t strict,
9098 int sub_strict)
9100 tree tempargs = copy_node (targs);
9101 int good = 0;
9102 bool addr_p;
9104 if (TREE_CODE (arg) == ADDR_EXPR)
9106 arg = TREE_OPERAND (arg, 0);
9107 addr_p = true;
9109 else
9110 addr_p = false;
9112 if (TREE_CODE (arg) == COMPONENT_REF)
9113 /* Handle `&x' where `x' is some static or non-static member
9114 function name. */
9115 arg = TREE_OPERAND (arg, 1);
9117 if (TREE_CODE (arg) == OFFSET_REF)
9118 arg = TREE_OPERAND (arg, 1);
9120 /* Strip baselink information. */
9121 if (BASELINK_P (arg))
9122 arg = BASELINK_FUNCTIONS (arg);
9124 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
9126 /* If we got some explicit template args, we need to plug them into
9127 the affected templates before we try to unify, in case the
9128 explicit args will completely resolve the templates in question. */
9130 tree expl_subargs = TREE_OPERAND (arg, 1);
9131 arg = TREE_OPERAND (arg, 0);
9133 for (; arg; arg = OVL_NEXT (arg))
9135 tree fn = OVL_CURRENT (arg);
9136 tree subargs, elem;
9138 if (TREE_CODE (fn) != TEMPLATE_DECL)
9139 continue;
9141 subargs = get_bindings_overload (fn, DECL_TEMPLATE_RESULT (fn),
9142 expl_subargs);
9143 if (subargs)
9145 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
9146 good += try_one_overload (tparms, targs, tempargs, parm,
9147 elem, strict, sub_strict, addr_p);
9151 else if (TREE_CODE (arg) == OVERLOAD
9152 || TREE_CODE (arg) == FUNCTION_DECL)
9154 for (; arg; arg = OVL_NEXT (arg))
9155 good += try_one_overload (tparms, targs, tempargs, parm,
9156 TREE_TYPE (OVL_CURRENT (arg)),
9157 strict, sub_strict, addr_p);
9159 else
9160 abort ();
9162 /* [temp.deduct.type] A template-argument can be deduced from a pointer
9163 to function or pointer to member function argument if the set of
9164 overloaded functions does not contain function templates and at most
9165 one of a set of overloaded functions provides a unique match.
9167 So if we found multiple possibilities, we return success but don't
9168 deduce anything. */
9170 if (good == 1)
9172 int i = TREE_VEC_LENGTH (targs);
9173 for (; i--; )
9174 if (TREE_VEC_ELT (tempargs, i))
9175 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
9177 if (good)
9178 return 0;
9180 return 1;
9183 /* Subroutine of resolve_overloaded_unification; does deduction for a single
9184 overload. Fills TARGS with any deduced arguments, or error_mark_node if
9185 different overloads deduce different arguments for a given parm.
9186 ADDR_P is true if the expression for which deduction is being
9187 performed was of the form "& fn" rather than simply "fn".
9189 Returns 1 on success. */
9191 static int
9192 try_one_overload (tree tparms,
9193 tree orig_targs,
9194 tree targs,
9195 tree parm,
9196 tree arg,
9197 unification_kind_t strict,
9198 int sub_strict,
9199 bool addr_p)
9201 int nargs;
9202 tree tempargs;
9203 int i;
9205 /* [temp.deduct.type] A template-argument can be deduced from a pointer
9206 to function or pointer to member function argument if the set of
9207 overloaded functions does not contain function templates and at most
9208 one of a set of overloaded functions provides a unique match.
9210 So if this is a template, just return success. */
9212 if (uses_template_parms (arg))
9213 return 1;
9215 if (TREE_CODE (arg) == METHOD_TYPE)
9216 arg = build_ptrmemfunc_type (build_pointer_type (arg));
9217 else if (addr_p)
9218 arg = build_pointer_type (arg);
9220 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg);
9222 /* We don't copy orig_targs for this because if we have already deduced
9223 some template args from previous args, unify would complain when we
9224 try to deduce a template parameter for the same argument, even though
9225 there isn't really a conflict. */
9226 nargs = TREE_VEC_LENGTH (targs);
9227 tempargs = make_tree_vec (nargs);
9229 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
9230 return 0;
9232 /* First make sure we didn't deduce anything that conflicts with
9233 explicitly specified args. */
9234 for (i = nargs; i--; )
9236 tree elt = TREE_VEC_ELT (tempargs, i);
9237 tree oldelt = TREE_VEC_ELT (orig_targs, i);
9239 if (elt == NULL_TREE)
9240 continue;
9241 else if (uses_template_parms (elt))
9243 /* Since we're unifying against ourselves, we will fill in template
9244 args used in the function parm list with our own template parms.
9245 Discard them. */
9246 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
9247 continue;
9249 else if (oldelt && ! template_args_equal (oldelt, elt))
9250 return 0;
9253 for (i = nargs; i--; )
9255 tree elt = TREE_VEC_ELT (tempargs, i);
9257 if (elt)
9258 TREE_VEC_ELT (targs, i) = elt;
9261 return 1;
9264 /* Verify that nondeduce template argument agrees with the type
9265 obtained from argument deduction. Return nonzero if the
9266 verification fails.
9268 For example:
9270 struct A { typedef int X; };
9271 template <class T, class U> struct C {};
9272 template <class T> struct C<T, typename T::X> {};
9274 Then with the instantiation `C<A, int>', we can deduce that
9275 `T' is `A' but unify () does not check whether `typename T::X'
9276 is `int'. This function ensure that they agree.
9278 TARGS, PARMS are the same as the arguments of unify.
9279 ARGS contains template arguments from all levels. */
9281 static int
9282 verify_class_unification (tree targs, tree parms, tree args)
9284 parms = tsubst (parms, add_outermost_template_args (args, targs),
9285 tf_none, NULL_TREE);
9286 if (parms == error_mark_node)
9287 return 1;
9289 return !comp_template_args (parms, INNERMOST_TEMPLATE_ARGS (args));
9292 /* PARM is a template class (perhaps with unbound template
9293 parameters). ARG is a fully instantiated type. If ARG can be
9294 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
9295 TARGS are as for unify. */
9297 static tree
9298 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
9300 tree copy_of_targs;
9302 if (!CLASSTYPE_TEMPLATE_INFO (arg)
9303 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
9304 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
9305 return NULL_TREE;
9307 /* We need to make a new template argument vector for the call to
9308 unify. If we used TARGS, we'd clutter it up with the result of
9309 the attempted unification, even if this class didn't work out.
9310 We also don't want to commit ourselves to all the unifications
9311 we've already done, since unification is supposed to be done on
9312 an argument-by-argument basis. In other words, consider the
9313 following pathological case:
9315 template <int I, int J, int K>
9316 struct S {};
9318 template <int I, int J>
9319 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
9321 template <int I, int J, int K>
9322 void f(S<I, J, K>, S<I, I, I>);
9324 void g() {
9325 S<0, 0, 0> s0;
9326 S<0, 1, 2> s2;
9328 f(s0, s2);
9331 Now, by the time we consider the unification involving `s2', we
9332 already know that we must have `f<0, 0, 0>'. But, even though
9333 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
9334 because there are two ways to unify base classes of S<0, 1, 2>
9335 with S<I, I, I>. If we kept the already deduced knowledge, we
9336 would reject the possibility I=1. */
9337 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
9339 /* If unification failed, we're done. */
9340 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
9341 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
9342 return NULL_TREE;
9344 return arg;
9347 /* Subroutine of get_template_base. RVAL, if non-NULL, is a base we
9348 have already discovered to be satisfactory. ARG_BINFO is the binfo
9349 for the base class of ARG that we are currently examining. */
9351 static tree
9352 get_template_base_recursive (tree tparms,
9353 tree targs,
9354 tree parm,
9355 tree arg_binfo,
9356 tree rval,
9357 int flags)
9359 tree binfos;
9360 int i, n_baselinks;
9361 tree arg = BINFO_TYPE (arg_binfo);
9363 if (!(flags & GTB_IGNORE_TYPE))
9365 tree r = try_class_unification (tparms, targs,
9366 parm, arg);
9368 /* If there is more than one satisfactory baseclass, then:
9370 [temp.deduct.call]
9372 If they yield more than one possible deduced A, the type
9373 deduction fails.
9375 applies. */
9376 if (r && rval && !same_type_p (r, rval))
9377 return error_mark_node;
9378 else if (r)
9379 rval = r;
9382 binfos = BINFO_BASETYPES (arg_binfo);
9383 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
9385 /* Process base types. */
9386 for (i = 0; i < n_baselinks; i++)
9388 tree base_binfo = TREE_VEC_ELT (binfos, i);
9389 int this_virtual;
9391 /* Skip this base, if we've already seen it. */
9392 if (BINFO_MARKED (base_binfo))
9393 continue;
9395 this_virtual =
9396 (flags & GTB_VIA_VIRTUAL) || TREE_VIA_VIRTUAL (base_binfo);
9398 /* When searching for a non-virtual, we cannot mark virtually
9399 found binfos. */
9400 if (! this_virtual)
9401 BINFO_MARKED (base_binfo) = 1;
9403 rval = get_template_base_recursive (tparms, targs,
9404 parm,
9405 base_binfo,
9406 rval,
9407 GTB_VIA_VIRTUAL * this_virtual);
9409 /* If we discovered more than one matching base class, we can
9410 stop now. */
9411 if (rval == error_mark_node)
9412 return error_mark_node;
9415 return rval;
9418 /* Given a template type PARM and a class type ARG, find the unique
9419 base type in ARG that is an instance of PARM. We do not examine
9420 ARG itself; only its base-classes. If there is no appropriate base
9421 class, return NULL_TREE. If there is more than one, return
9422 error_mark_node. PARM may be the type of a partial specialization,
9423 as well as a plain template type. Used by unify. */
9425 static tree
9426 get_template_base (tree tparms, tree targs, tree parm, tree arg)
9428 tree rval;
9429 tree arg_binfo;
9431 my_friendly_assert (IS_AGGR_TYPE_CODE (TREE_CODE (arg)), 92);
9433 arg_binfo = TYPE_BINFO (complete_type (arg));
9434 rval = get_template_base_recursive (tparms, targs,
9435 parm, arg_binfo,
9436 NULL_TREE,
9437 GTB_IGNORE_TYPE);
9439 /* Since get_template_base_recursive marks the bases classes, we
9440 must unmark them here. */
9441 dfs_walk (arg_binfo, dfs_unmark, markedp, 0);
9443 return rval;
9446 /* Returns the level of DECL, which declares a template parameter. */
9448 static int
9449 template_decl_level (tree decl)
9451 switch (TREE_CODE (decl))
9453 case TYPE_DECL:
9454 case TEMPLATE_DECL:
9455 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
9457 case PARM_DECL:
9458 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
9460 default:
9461 abort ();
9462 return 0;
9466 /* Decide whether ARG can be unified with PARM, considering only the
9467 cv-qualifiers of each type, given STRICT as documented for unify.
9468 Returns nonzero iff the unification is OK on that basis.*/
9470 static int
9471 check_cv_quals_for_unify (int strict, tree arg, tree parm)
9473 int arg_quals = cp_type_quals (arg);
9474 int parm_quals = cp_type_quals (parm);
9476 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM)
9478 /* If the cvr quals of parm will not unify with ARG, they'll be
9479 ignored in instantiation, so we have to do the same here. */
9480 if (TREE_CODE (arg) == REFERENCE_TYPE)
9481 parm_quals &= ~(TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE);
9482 if (!POINTER_TYPE_P (arg) &&
9483 TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
9484 parm_quals &= ~TYPE_QUAL_RESTRICT;
9487 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
9488 && (arg_quals & parm_quals) != parm_quals)
9489 return 0;
9491 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
9492 && (parm_quals & arg_quals) != arg_quals)
9493 return 0;
9495 return 1;
9498 /* Takes parameters as for type_unification. Returns 0 if the
9499 type deduction succeeds, 1 otherwise. The parameter STRICT is a
9500 bitwise or of the following flags:
9502 UNIFY_ALLOW_NONE:
9503 Require an exact match between PARM and ARG.
9504 UNIFY_ALLOW_MORE_CV_QUAL:
9505 Allow the deduced ARG to be more cv-qualified (by qualification
9506 conversion) than ARG.
9507 UNIFY_ALLOW_LESS_CV_QUAL:
9508 Allow the deduced ARG to be less cv-qualified than ARG.
9509 UNIFY_ALLOW_DERIVED:
9510 Allow the deduced ARG to be a template base class of ARG,
9511 or a pointer to a template base class of the type pointed to by
9512 ARG.
9513 UNIFY_ALLOW_INTEGER:
9514 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
9515 case for more information.
9516 UNIFY_ALLOW_OUTER_LEVEL:
9517 This is the outermost level of a deduction. Used to determine validity
9518 of qualification conversions. A valid qualification conversion must
9519 have const qualified pointers leading up to the inner type which
9520 requires additional CV quals, except at the outer level, where const
9521 is not required [conv.qual]. It would be normal to set this flag in
9522 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
9523 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
9524 This is the outermost level of a deduction, and PARM can be more CV
9525 qualified at this point.
9526 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
9527 This is the outermost level of a deduction, and PARM can be less CV
9528 qualified at this point.
9529 UNIFY_ALLOW_MAX_CORRECTION:
9530 This is an INTEGER_TYPE's maximum value. Used if the range may
9531 have been derived from a size specification, such as an array size.
9532 If the size was given by a nontype template parameter N, the maximum
9533 value will have the form N-1. The flag says that we can (and indeed
9534 must) unify N with (ARG + 1), an exception to the normal rules on
9535 folding PARM. */
9537 static int
9538 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
9540 int idx;
9541 tree targ;
9542 tree tparm;
9543 int strict_in = strict;
9545 /* I don't think this will do the right thing with respect to types.
9546 But the only case I've seen it in so far has been array bounds, where
9547 signedness is the only information lost, and I think that will be
9548 okay. */
9549 while (TREE_CODE (parm) == NOP_EXPR)
9550 parm = TREE_OPERAND (parm, 0);
9552 if (arg == error_mark_node)
9553 return 1;
9554 if (arg == unknown_type_node)
9555 /* We can't deduce anything from this, but we might get all the
9556 template args from other function args. */
9557 return 0;
9559 /* If PARM uses template parameters, then we can't bail out here,
9560 even if ARG == PARM, since we won't record unifications for the
9561 template parameters. We might need them if we're trying to
9562 figure out which of two things is more specialized. */
9563 if (arg == parm && !uses_template_parms (parm))
9564 return 0;
9566 /* Immediately reject some pairs that won't unify because of
9567 cv-qualification mismatches. */
9568 if (TREE_CODE (arg) == TREE_CODE (parm)
9569 && TYPE_P (arg)
9570 /* It is the elements of the array which hold the cv quals of an array
9571 type, and the elements might be template type parms. We'll check
9572 when we recurse. */
9573 && TREE_CODE (arg) != ARRAY_TYPE
9574 /* We check the cv-qualifiers when unifying with template type
9575 parameters below. We want to allow ARG `const T' to unify with
9576 PARM `T' for example, when computing which of two templates
9577 is more specialized, for example. */
9578 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
9579 && !check_cv_quals_for_unify (strict_in, arg, parm))
9580 return 1;
9582 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
9583 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
9584 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
9585 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
9586 strict &= ~UNIFY_ALLOW_DERIVED;
9587 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
9588 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
9589 strict &= ~UNIFY_ALLOW_MAX_CORRECTION;
9591 switch (TREE_CODE (parm))
9593 case TYPENAME_TYPE:
9594 case SCOPE_REF:
9595 case UNBOUND_CLASS_TEMPLATE:
9596 /* In a type which contains a nested-name-specifier, template
9597 argument values cannot be deduced for template parameters used
9598 within the nested-name-specifier. */
9599 return 0;
9601 case TEMPLATE_TYPE_PARM:
9602 case TEMPLATE_TEMPLATE_PARM:
9603 case BOUND_TEMPLATE_TEMPLATE_PARM:
9604 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
9606 if (TEMPLATE_TYPE_LEVEL (parm)
9607 != template_decl_level (tparm))
9608 /* The PARM is not one we're trying to unify. Just check
9609 to see if it matches ARG. */
9610 return (TREE_CODE (arg) == TREE_CODE (parm)
9611 && same_type_p (parm, arg)) ? 0 : 1;
9612 idx = TEMPLATE_TYPE_IDX (parm);
9613 targ = TREE_VEC_ELT (targs, idx);
9614 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
9616 /* Check for mixed types and values. */
9617 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
9618 && TREE_CODE (tparm) != TYPE_DECL)
9619 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
9620 && TREE_CODE (tparm) != TEMPLATE_DECL))
9621 return 1;
9623 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
9625 /* ARG must be constructed from a template class or a template
9626 template parameter. */
9627 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
9628 && (TREE_CODE (arg) != RECORD_TYPE || !CLASSTYPE_TEMPLATE_INFO (arg)))
9629 return 1;
9632 tree parmtmpl = TYPE_TI_TEMPLATE (parm);
9633 tree parmvec = TYPE_TI_ARGS (parm);
9634 tree argvec = TYPE_TI_ARGS (arg);
9635 tree argtmplvec
9636 = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_TI_TEMPLATE (arg));
9637 int i;
9639 /* The parameter and argument roles have to be switched here
9640 in order to handle default arguments properly. For example,
9641 template<template <class> class TT> void f(TT<int>)
9642 should be able to accept vector<int> which comes from
9643 template <class T, class Allocator = allocator>
9644 class vector. */
9646 if (coerce_template_parms (argtmplvec, parmvec, parmtmpl, 0, 1)
9647 == error_mark_node)
9648 return 1;
9650 /* Deduce arguments T, i from TT<T> or TT<i>.
9651 We check each element of PARMVEC and ARGVEC individually
9652 rather than the whole TREE_VEC since they can have
9653 different number of elements. */
9655 for (i = 0; i < TREE_VEC_LENGTH (parmvec); ++i)
9657 tree t = TREE_VEC_ELT (parmvec, i);
9659 if (unify (tparms, targs, t,
9660 TREE_VEC_ELT (argvec, i),
9661 UNIFY_ALLOW_NONE))
9662 return 1;
9665 arg = TYPE_TI_TEMPLATE (arg);
9667 /* Fall through to deduce template name. */
9670 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
9671 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
9673 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
9675 /* Simple cases: Value already set, does match or doesn't. */
9676 if (targ != NULL_TREE && template_args_equal (targ, arg))
9677 return 0;
9678 else if (targ)
9679 return 1;
9681 else
9683 /* If PARM is `const T' and ARG is only `int', we don't have
9684 a match unless we are allowing additional qualification.
9685 If ARG is `const int' and PARM is just `T' that's OK;
9686 that binds `const int' to `T'. */
9687 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
9688 arg, parm))
9689 return 1;
9691 /* Consider the case where ARG is `const volatile int' and
9692 PARM is `const T'. Then, T should be `volatile int'. */
9693 arg = cp_build_qualified_type_real
9694 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
9695 if (arg == error_mark_node)
9696 return 1;
9698 /* Simple cases: Value already set, does match or doesn't. */
9699 if (targ != NULL_TREE && same_type_p (targ, arg))
9700 return 0;
9701 else if (targ)
9702 return 1;
9704 /* Make sure that ARG is not a variable-sized array. (Note
9705 that were talking about variable-sized arrays (like
9706 `int[n]'), rather than arrays of unknown size (like
9707 `int[]').) We'll get very confused by such a type since
9708 the bound of the array will not be computable in an
9709 instantiation. Besides, such types are not allowed in
9710 ISO C++, so we can do as we please here. */
9711 if (variably_modified_type_p (arg))
9712 return 1;
9715 TREE_VEC_ELT (targs, idx) = arg;
9716 return 0;
9718 case TEMPLATE_PARM_INDEX:
9719 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
9721 if (TEMPLATE_PARM_LEVEL (parm)
9722 != template_decl_level (tparm))
9723 /* The PARM is not one we're trying to unify. Just check
9724 to see if it matches ARG. */
9725 return !(TREE_CODE (arg) == TREE_CODE (parm)
9726 && cp_tree_equal (parm, arg));
9728 idx = TEMPLATE_PARM_IDX (parm);
9729 targ = TREE_VEC_ELT (targs, idx);
9731 if (targ)
9732 return !cp_tree_equal (targ, arg);
9734 /* [temp.deduct.type] If, in the declaration of a function template
9735 with a non-type template-parameter, the non-type
9736 template-parameter is used in an expression in the function
9737 parameter-list and, if the corresponding template-argument is
9738 deduced, the template-argument type shall match the type of the
9739 template-parameter exactly, except that a template-argument
9740 deduced from an array bound may be of any integral type.
9741 The non-type parameter might use already deduced type parameters. */
9742 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
9743 if (!TREE_TYPE (arg))
9744 /* Template-parameter dependent expression. Just accept it for now.
9745 It will later be processed in convert_template_argument. */
9747 else if (same_type_p (TREE_TYPE (arg), tparm))
9748 /* OK */;
9749 else if ((strict & UNIFY_ALLOW_INTEGER)
9750 && (TREE_CODE (tparm) == INTEGER_TYPE
9751 || TREE_CODE (tparm) == BOOLEAN_TYPE))
9752 /* OK */;
9753 else if (uses_template_parms (tparm))
9754 /* We haven't deduced the type of this parameter yet. Try again
9755 later. */
9756 return 0;
9757 else
9758 return 1;
9760 TREE_VEC_ELT (targs, idx) = arg;
9761 return 0;
9763 case PTRMEM_CST:
9765 /* A pointer-to-member constant can be unified only with
9766 another constant. */
9767 if (TREE_CODE (arg) != PTRMEM_CST)
9768 return 1;
9770 /* Just unify the class member. It would be useless (and possibly
9771 wrong, depending on the strict flags) to unify also
9772 PTRMEM_CST_CLASS, because we want to be sure that both parm and
9773 arg refer to the same variable, even if through different
9774 classes. For instance:
9776 struct A { int x; };
9777 struct B : A { };
9779 Unification of &A::x and &B::x must succeed. */
9780 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
9781 PTRMEM_CST_MEMBER (arg), strict);
9784 case POINTER_TYPE:
9786 if (TREE_CODE (arg) != POINTER_TYPE)
9787 return 1;
9789 /* [temp.deduct.call]
9791 A can be another pointer or pointer to member type that can
9792 be converted to the deduced A via a qualification
9793 conversion (_conv.qual_).
9795 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
9796 This will allow for additional cv-qualification of the
9797 pointed-to types if appropriate. */
9799 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
9800 /* The derived-to-base conversion only persists through one
9801 level of pointers. */
9802 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
9804 return unify (tparms, targs, TREE_TYPE (parm),
9805 TREE_TYPE (arg), strict);
9808 case REFERENCE_TYPE:
9809 if (TREE_CODE (arg) != REFERENCE_TYPE)
9810 return 1;
9811 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
9812 strict & UNIFY_ALLOW_MORE_CV_QUAL);
9814 case ARRAY_TYPE:
9815 if (TREE_CODE (arg) != ARRAY_TYPE)
9816 return 1;
9817 if ((TYPE_DOMAIN (parm) == NULL_TREE)
9818 != (TYPE_DOMAIN (arg) == NULL_TREE))
9819 return 1;
9820 if (TYPE_DOMAIN (parm) != NULL_TREE
9821 && unify (tparms, targs, TYPE_DOMAIN (parm),
9822 TYPE_DOMAIN (arg), UNIFY_ALLOW_NONE) != 0)
9823 return 1;
9824 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
9825 strict & UNIFY_ALLOW_MORE_CV_QUAL);
9827 case REAL_TYPE:
9828 case COMPLEX_TYPE:
9829 case VECTOR_TYPE:
9830 case INTEGER_TYPE:
9831 case BOOLEAN_TYPE:
9832 case VOID_TYPE:
9833 if (TREE_CODE (arg) != TREE_CODE (parm))
9834 return 1;
9836 if (TREE_CODE (parm) == INTEGER_TYPE
9837 && TREE_CODE (TYPE_MAX_VALUE (parm)) != INTEGER_CST)
9839 if (TYPE_MIN_VALUE (parm) && TYPE_MIN_VALUE (arg)
9840 && unify (tparms, targs, TYPE_MIN_VALUE (parm),
9841 TYPE_MIN_VALUE (arg), UNIFY_ALLOW_INTEGER))
9842 return 1;
9843 if (TYPE_MAX_VALUE (parm) && TYPE_MAX_VALUE (arg)
9844 && unify (tparms, targs, TYPE_MAX_VALUE (parm),
9845 TYPE_MAX_VALUE (arg),
9846 UNIFY_ALLOW_INTEGER | UNIFY_ALLOW_MAX_CORRECTION))
9847 return 1;
9849 /* We have already checked cv-qualification at the top of the
9850 function. */
9851 else if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
9852 return 1;
9854 /* As far as unification is concerned, this wins. Later checks
9855 will invalidate it if necessary. */
9856 return 0;
9858 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
9859 /* Type INTEGER_CST can come from ordinary constant template args. */
9860 case INTEGER_CST:
9861 while (TREE_CODE (arg) == NOP_EXPR)
9862 arg = TREE_OPERAND (arg, 0);
9864 if (TREE_CODE (arg) != INTEGER_CST)
9865 return 1;
9866 return !tree_int_cst_equal (parm, arg);
9868 case TREE_VEC:
9870 int i;
9871 if (TREE_CODE (arg) != TREE_VEC)
9872 return 1;
9873 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
9874 return 1;
9875 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
9876 if (unify (tparms, targs,
9877 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
9878 UNIFY_ALLOW_NONE))
9879 return 1;
9880 return 0;
9883 case RECORD_TYPE:
9884 case UNION_TYPE:
9885 if (TREE_CODE (arg) != TREE_CODE (parm))
9886 return 1;
9888 if (TYPE_PTRMEMFUNC_P (parm))
9890 if (!TYPE_PTRMEMFUNC_P (arg))
9891 return 1;
9893 return unify (tparms, targs,
9894 TYPE_PTRMEMFUNC_FN_TYPE (parm),
9895 TYPE_PTRMEMFUNC_FN_TYPE (arg),
9896 strict);
9899 if (CLASSTYPE_TEMPLATE_INFO (parm))
9901 tree t = NULL_TREE;
9903 if (strict_in & UNIFY_ALLOW_DERIVED)
9905 /* First, we try to unify the PARM and ARG directly. */
9906 t = try_class_unification (tparms, targs,
9907 parm, arg);
9909 if (!t)
9911 /* Fallback to the special case allowed in
9912 [temp.deduct.call]:
9914 If P is a class, and P has the form
9915 template-id, then A can be a derived class of
9916 the deduced A. Likewise, if P is a pointer to
9917 a class of the form template-id, A can be a
9918 pointer to a derived class pointed to by the
9919 deduced A. */
9920 t = get_template_base (tparms, targs,
9921 parm, arg);
9923 if (! t || t == error_mark_node)
9924 return 1;
9927 else if (CLASSTYPE_TEMPLATE_INFO (arg)
9928 && (CLASSTYPE_TI_TEMPLATE (parm)
9929 == CLASSTYPE_TI_TEMPLATE (arg)))
9930 /* Perhaps PARM is something like S<U> and ARG is S<int>.
9931 Then, we should unify `int' and `U'. */
9932 t = arg;
9933 else
9934 /* There's no chance of unification succeeding. */
9935 return 1;
9937 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
9938 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
9940 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
9941 return 1;
9942 return 0;
9944 case METHOD_TYPE:
9945 case FUNCTION_TYPE:
9946 if (TREE_CODE (arg) != TREE_CODE (parm))
9947 return 1;
9949 if (unify (tparms, targs, TREE_TYPE (parm),
9950 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
9951 return 1;
9952 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
9953 TYPE_ARG_TYPES (arg), 1,
9954 DEDUCE_EXACT, 0, -1);
9956 case OFFSET_TYPE:
9957 if (TREE_CODE (arg) != OFFSET_TYPE)
9958 return 1;
9959 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
9960 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
9961 return 1;
9962 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
9963 strict);
9965 case CONST_DECL:
9966 if (DECL_TEMPLATE_PARM_P (parm))
9967 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
9968 if (arg != decl_constant_value (parm))
9969 return 1;
9970 return 0;
9972 case FIELD_DECL:
9973 case TEMPLATE_DECL:
9974 /* Matched cases are handled by the ARG == PARM test above. */
9975 return 1;
9977 case MINUS_EXPR:
9978 if (tree_int_cst_equal (TREE_OPERAND (parm, 1), integer_one_node)
9979 && (strict_in & UNIFY_ALLOW_MAX_CORRECTION))
9981 /* We handle this case specially, since it comes up with
9982 arrays. In particular, something like:
9984 template <int N> void f(int (&x)[N]);
9986 Here, we are trying to unify the range type, which
9987 looks like [0 ... (N - 1)]. */
9988 tree t, t1, t2;
9989 t1 = TREE_OPERAND (parm, 0);
9990 t2 = TREE_OPERAND (parm, 1);
9992 t = fold (build (PLUS_EXPR, integer_type_node, arg, t2));
9994 return unify (tparms, targs, t1, t, strict);
9996 /* else fall through */
9998 default:
9999 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (parm))))
10002 /* We're looking at an expression. This can happen with
10003 something like:
10005 template <int I>
10006 void foo(S<I>, S<I + 2>);
10008 This is a "nondeduced context":
10010 [deduct.type]
10012 The nondeduced contexts are:
10014 --A type that is a template-id in which one or more of
10015 the template-arguments is an expression that references
10016 a template-parameter.
10018 In these cases, we assume deduction succeeded, but don't
10019 actually infer any unifications. */
10021 if (!uses_template_parms (parm)
10022 && !template_args_equal (parm, arg))
10023 return 1;
10024 else
10025 return 0;
10027 else
10028 sorry ("use of `%s' in template type unification",
10029 tree_code_name [(int) TREE_CODE (parm)]);
10031 return 1;
10035 /* Called if RESULT is explicitly instantiated, or is a member of an
10036 explicitly instantiated class, or if using -frepo and the
10037 instantiation of RESULT has been assigned to this file. */
10039 void
10040 mark_decl_instantiated (tree result, int extern_p)
10042 /* We used to set this unconditionally; we moved that to
10043 do_decl_instantiation so it wouldn't get set on members of
10044 explicit class template instantiations. But we still need to set
10045 it here for the 'extern template' case in order to suppress
10046 implicit instantiations. */
10047 if (extern_p)
10048 SET_DECL_EXPLICIT_INSTANTIATION (result);
10050 /* If this entity has already been written out, it's too late to
10051 make any modifications. */
10052 if (TREE_ASM_WRITTEN (result))
10053 return;
10055 if (TREE_CODE (result) != FUNCTION_DECL)
10056 /* The TREE_PUBLIC flag for function declarations will have been
10057 set correctly by tsubst. */
10058 TREE_PUBLIC (result) = 1;
10060 /* This might have been set by an earlier implicit instantiation. */
10061 DECL_COMDAT (result) = 0;
10063 if (! extern_p)
10065 DECL_INTERFACE_KNOWN (result) = 1;
10066 DECL_NOT_REALLY_EXTERN (result) = 1;
10068 /* Always make artificials weak. */
10069 if (DECL_ARTIFICIAL (result) && flag_weak)
10070 comdat_linkage (result);
10071 /* For WIN32 we also want to put explicit instantiations in
10072 linkonce sections. */
10073 else if (TREE_PUBLIC (result))
10074 maybe_make_one_only (result);
10077 if (TREE_CODE (result) == FUNCTION_DECL)
10078 defer_fn (result);
10081 /* Given two function templates PAT1 and PAT2, return:
10083 DEDUCE should be DEDUCE_EXACT or DEDUCE_ORDER.
10085 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
10086 -1 if PAT2 is more specialized than PAT1.
10087 0 if neither is more specialized.
10089 LEN is passed through to fn_type_unification. */
10092 more_specialized (tree pat1, tree pat2, int deduce, int len)
10094 tree targs;
10095 int winner = 0;
10097 /* If template argument deduction succeeds, we substitute the
10098 resulting arguments into non-deduced contexts. While doing that,
10099 we must be aware that we may encounter dependent types. */
10100 ++processing_template_decl;
10101 targs = get_bindings_real (pat1, DECL_TEMPLATE_RESULT (pat2),
10102 NULL_TREE, 0, deduce, len);
10103 if (targs)
10104 --winner;
10106 targs = get_bindings_real (pat2, DECL_TEMPLATE_RESULT (pat1),
10107 NULL_TREE, 0, deduce, len);
10108 if (targs)
10109 ++winner;
10110 --processing_template_decl;
10112 return winner;
10115 /* Given two class template specialization list nodes PAT1 and PAT2, return:
10117 1 if PAT1 is more specialized than PAT2 as described in [temp.class.order].
10118 -1 if PAT2 is more specialized than PAT1.
10119 0 if neither is more specialized.
10121 FULL_ARGS is the full set of template arguments that triggers this
10122 partial ordering. */
10125 more_specialized_class (tree pat1, tree pat2, tree full_args)
10127 tree targs;
10128 int winner = 0;
10130 targs = get_class_bindings (TREE_VALUE (pat1), TREE_PURPOSE (pat1),
10131 add_outermost_template_args (full_args, TREE_PURPOSE (pat2)));
10132 if (targs)
10133 --winner;
10135 targs = get_class_bindings (TREE_VALUE (pat2), TREE_PURPOSE (pat2),
10136 add_outermost_template_args (full_args, TREE_PURPOSE (pat1)));
10137 if (targs)
10138 ++winner;
10140 return winner;
10143 /* Return the template arguments that will produce the function signature
10144 DECL from the function template FN, with the explicit template
10145 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is 1, the return type must
10146 also match. Return NULL_TREE if no satisfactory arguments could be
10147 found. DEDUCE and LEN are passed through to fn_type_unification. */
10149 static tree
10150 get_bindings_real (tree fn,
10151 tree decl,
10152 tree explicit_args,
10153 int check_rettype,
10154 int deduce,
10155 int len)
10157 int ntparms = DECL_NTPARMS (fn);
10158 tree targs = make_tree_vec (ntparms);
10159 tree decl_type;
10160 tree decl_arg_types;
10161 int i;
10163 /* Substitute the explicit template arguments into the type of DECL.
10164 The call to fn_type_unification will handle substitution into the
10165 FN. */
10166 decl_type = TREE_TYPE (decl);
10167 if (explicit_args && uses_template_parms (decl_type))
10169 tree tmpl;
10170 tree converted_args;
10172 if (DECL_TEMPLATE_INFO (decl))
10173 tmpl = DECL_TI_TEMPLATE (decl);
10174 else
10175 /* We can get here for some invalid specializations. */
10176 return NULL_TREE;
10178 converted_args
10179 = (coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
10180 explicit_args, NULL_TREE,
10181 tf_none, /*require_all_arguments=*/0));
10182 if (converted_args == error_mark_node)
10183 return NULL_TREE;
10185 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
10186 if (decl_type == error_mark_node)
10187 return NULL_TREE;
10190 decl_arg_types = TYPE_ARG_TYPES (decl_type);
10191 /* Never do unification on the 'this' parameter. */
10192 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
10193 decl_arg_types = TREE_CHAIN (decl_arg_types);
10195 i = fn_type_unification (fn, explicit_args, targs,
10196 decl_arg_types,
10197 (check_rettype || DECL_CONV_FN_P (fn)
10198 ? TREE_TYPE (decl_type) : NULL_TREE),
10199 deduce, len);
10201 if (i != 0)
10202 return NULL_TREE;
10204 return targs;
10207 /* For most uses, we want to check the return type. */
10209 static tree
10210 get_bindings (tree fn, tree decl, tree explicit_args)
10212 return get_bindings_real (fn, decl, explicit_args, 1, DEDUCE_EXACT, -1);
10215 /* But for resolve_overloaded_unification, we only care about the parameter
10216 types. */
10218 static tree
10219 get_bindings_overload (tree fn, tree decl, tree explicit_args)
10221 return get_bindings_real (fn, decl, explicit_args, 0, DEDUCE_EXACT, -1);
10224 /* Return the innermost template arguments that, when applied to a
10225 template specialization whose innermost template parameters are
10226 TPARMS, and whose specialization arguments are PARMS, yield the
10227 ARGS.
10229 For example, suppose we have:
10231 template <class T, class U> struct S {};
10232 template <class T> struct S<T*, int> {};
10234 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
10235 {T}, the PARMS will be {T*, int} and the ARGS will be {double*,
10236 int}. The resulting vector will be {double}, indicating that `T'
10237 is bound to `double'. */
10239 static tree
10240 get_class_bindings (tree tparms, tree parms, tree args)
10242 int i, ntparms = TREE_VEC_LENGTH (tparms);
10243 tree vec = make_tree_vec (ntparms);
10245 if (unify (tparms, vec, parms, INNERMOST_TEMPLATE_ARGS (args),
10246 UNIFY_ALLOW_NONE))
10247 return NULL_TREE;
10249 for (i = 0; i < ntparms; ++i)
10250 if (! TREE_VEC_ELT (vec, i))
10251 return NULL_TREE;
10253 if (verify_class_unification (vec, parms, args))
10254 return NULL_TREE;
10256 return vec;
10259 /* In INSTANTIATIONS is a list of <INSTANTIATION, TEMPLATE> pairs.
10260 Pick the most specialized template, and return the corresponding
10261 instantiation, or if there is no corresponding instantiation, the
10262 template itself. If there is no most specialized template,
10263 error_mark_node is returned. If there are no templates at all,
10264 NULL_TREE is returned. */
10266 tree
10267 most_specialized_instantiation (tree instantiations)
10269 tree fn, champ;
10270 int fate;
10272 if (!instantiations)
10273 return NULL_TREE;
10275 champ = instantiations;
10276 for (fn = TREE_CHAIN (instantiations); fn; fn = TREE_CHAIN (fn))
10278 fate = more_specialized (TREE_VALUE (champ), TREE_VALUE (fn),
10279 DEDUCE_EXACT, -1);
10280 if (fate == 1)
10282 else
10284 if (fate == 0)
10286 fn = TREE_CHAIN (fn);
10287 if (! fn)
10288 return error_mark_node;
10290 champ = fn;
10294 for (fn = instantiations; fn && fn != champ; fn = TREE_CHAIN (fn))
10296 fate = more_specialized (TREE_VALUE (champ), TREE_VALUE (fn),
10297 DEDUCE_EXACT, -1);
10298 if (fate != 1)
10299 return error_mark_node;
10302 return TREE_PURPOSE (champ) ? TREE_PURPOSE (champ) : TREE_VALUE (champ);
10305 /* Return the most specialized of the list of templates in FNS that can
10306 produce an instantiation matching DECL, given the explicit template
10307 arguments EXPLICIT_ARGS. */
10309 static tree
10310 most_specialized (tree fns, tree decl, tree explicit_args)
10312 tree candidates = NULL_TREE;
10313 tree fn, args;
10315 for (fn = fns; fn; fn = TREE_CHAIN (fn))
10317 tree candidate = TREE_VALUE (fn);
10319 args = get_bindings (candidate, decl, explicit_args);
10320 if (args)
10321 candidates = tree_cons (NULL_TREE, candidate, candidates);
10324 return most_specialized_instantiation (candidates);
10327 /* If DECL is a specialization of some template, return the most
10328 general such template. Otherwise, returns NULL_TREE.
10330 For example, given:
10332 template <class T> struct S { template <class U> void f(U); };
10334 if TMPL is `template <class U> void S<int>::f(U)' this will return
10335 the full template. This function will not trace past partial
10336 specializations, however. For example, given in addition:
10338 template <class T> struct S<T*> { template <class U> void f(U); };
10340 if TMPL is `template <class U> void S<int*>::f(U)' this will return
10341 `template <class T> template <class U> S<T*>::f(U)'. */
10343 tree
10344 most_general_template (tree decl)
10346 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
10347 an immediate specialization. */
10348 if (TREE_CODE (decl) == FUNCTION_DECL)
10350 if (DECL_TEMPLATE_INFO (decl)) {
10351 decl = DECL_TI_TEMPLATE (decl);
10353 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
10354 template friend. */
10355 if (TREE_CODE (decl) != TEMPLATE_DECL)
10356 return NULL_TREE;
10357 } else
10358 return NULL_TREE;
10361 /* Look for more and more general templates. */
10362 while (DECL_TEMPLATE_INFO (decl))
10364 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
10365 (See cp-tree.h for details.) */
10366 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
10367 break;
10369 if (CLASS_TYPE_P (TREE_TYPE (decl))
10370 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
10371 break;
10373 /* Stop if we run into an explicitly specialized class template. */
10374 if (!DECL_NAMESPACE_SCOPE_P (decl)
10375 && DECL_CONTEXT (decl)
10376 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
10377 break;
10379 decl = DECL_TI_TEMPLATE (decl);
10382 return decl;
10385 /* Return the most specialized of the class template specializations
10386 of TMPL which can produce an instantiation matching ARGS, or
10387 error_mark_node if the choice is ambiguous. */
10389 static tree
10390 most_specialized_class (tree tmpl, tree args)
10392 tree list = NULL_TREE;
10393 tree t;
10394 tree champ;
10395 int fate;
10397 tmpl = most_general_template (tmpl);
10398 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
10400 tree spec_args
10401 = get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t), args);
10402 if (spec_args)
10404 list = tree_cons (TREE_PURPOSE (t), TREE_VALUE (t), list);
10405 TREE_TYPE (list) = TREE_TYPE (t);
10409 if (! list)
10410 return NULL_TREE;
10412 t = list;
10413 champ = t;
10414 t = TREE_CHAIN (t);
10415 for (; t; t = TREE_CHAIN (t))
10417 fate = more_specialized_class (champ, t, args);
10418 if (fate == 1)
10420 else
10422 if (fate == 0)
10424 t = TREE_CHAIN (t);
10425 if (! t)
10426 return error_mark_node;
10428 champ = t;
10432 for (t = list; t && t != champ; t = TREE_CHAIN (t))
10434 fate = more_specialized_class (champ, t, args);
10435 if (fate != 1)
10436 return error_mark_node;
10439 return champ;
10442 /* Explicitly instantiate DECL. */
10444 void
10445 do_decl_instantiation (tree decl, tree storage)
10447 tree result = NULL_TREE;
10448 int extern_p = 0;
10450 if (!decl)
10451 /* An error occurred, for which grokdeclarator has already issued
10452 an appropriate message. */
10453 return;
10454 else if (! DECL_LANG_SPECIFIC (decl))
10456 error ("explicit instantiation of non-template `%#D'", decl);
10457 return;
10459 else if (TREE_CODE (decl) == VAR_DECL)
10461 /* There is an asymmetry here in the way VAR_DECLs and
10462 FUNCTION_DECLs are handled by grokdeclarator. In the case of
10463 the latter, the DECL we get back will be marked as a
10464 template instantiation, and the appropriate
10465 DECL_TEMPLATE_INFO will be set up. This does not happen for
10466 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
10467 should handle VAR_DECLs as it currently handles
10468 FUNCTION_DECLs. */
10469 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
10470 if (!result || TREE_CODE (result) != VAR_DECL)
10472 error ("no matching template for `%D' found", decl);
10473 return;
10476 else if (TREE_CODE (decl) != FUNCTION_DECL)
10478 error ("explicit instantiation of `%#D'", decl);
10479 return;
10481 else
10482 result = decl;
10484 /* Check for various error cases. Note that if the explicit
10485 instantiation is valid the RESULT will currently be marked as an
10486 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
10487 until we get here. */
10489 if (DECL_TEMPLATE_SPECIALIZATION (result))
10491 /* DR 259 [temp.spec].
10493 Both an explicit instantiation and a declaration of an explicit
10494 specialization shall not appear in a program unless the explicit
10495 instantiation follows a declaration of the explicit specialization.
10497 For a given set of template parameters, if an explicit
10498 instantiation of a template appears after a declaration of an
10499 explicit specialization for that template, the explicit
10500 instantiation has no effect. */
10501 return;
10503 else if (DECL_EXPLICIT_INSTANTIATION (result))
10505 /* [temp.spec]
10507 No program shall explicitly instantiate any template more
10508 than once.
10510 We check DECL_INTERFACE_KNOWN so as not to complain when the first
10511 instantiation was `extern' and the second is not, and EXTERN_P for
10512 the opposite case. If -frepo, chances are we already got marked
10513 as an explicit instantiation because of the repo file. */
10514 if (DECL_INTERFACE_KNOWN (result) && !extern_p && !flag_use_repository)
10515 pedwarn ("duplicate explicit instantiation of `%#D'", result);
10517 /* If we've already instantiated the template, just return now. */
10518 if (DECL_INTERFACE_KNOWN (result))
10519 return;
10521 else if (!DECL_IMPLICIT_INSTANTIATION (result))
10523 error ("no matching template for `%D' found", result);
10524 return;
10526 else if (!DECL_TEMPLATE_INFO (result))
10528 pedwarn ("explicit instantiation of non-template `%#D'", result);
10529 return;
10532 if (flag_external_templates)
10533 return;
10535 if (storage == NULL_TREE)
10537 else if (storage == ridpointers[(int) RID_EXTERN])
10539 if (pedantic && !in_system_header)
10540 pedwarn ("ISO C++ forbids the use of `extern' on explicit instantiations");
10541 extern_p = 1;
10543 else
10544 error ("storage class `%D' applied to template instantiation",
10545 storage);
10547 SET_DECL_EXPLICIT_INSTANTIATION (result);
10548 mark_decl_instantiated (result, extern_p);
10549 repo_template_instantiated (result, extern_p);
10550 if (! extern_p)
10551 instantiate_decl (result, /*defer_ok=*/1);
10554 void
10555 mark_class_instantiated (tree t, int extern_p)
10557 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
10558 SET_CLASSTYPE_INTERFACE_KNOWN (t);
10559 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
10560 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
10561 if (! extern_p)
10563 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
10564 rest_of_type_compilation (t, 1);
10568 /* Called from do_type_instantiation through binding_table_foreach to
10569 do recursive instantiation for the type bound in ENTRY. */
10570 static void
10571 bt_instantiate_type_proc (binding_entry entry, void *data)
10573 tree storage = *(tree *) data;
10575 if (IS_AGGR_TYPE (entry->type)
10576 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
10577 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
10580 /* Perform an explicit instantiation of template class T. STORAGE, if
10581 non-null, is the RID for extern, inline or static. COMPLAIN is
10582 nonzero if this is called from the parser, zero if called recursively,
10583 since the standard is unclear (as detailed below). */
10585 void
10586 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
10588 int extern_p = 0;
10589 int nomem_p = 0;
10590 int static_p = 0;
10592 if (TREE_CODE (t) == TYPE_DECL)
10593 t = TREE_TYPE (t);
10595 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
10597 error ("explicit instantiation of non-template type `%T'", t);
10598 return;
10601 complete_type (t);
10603 /* With -fexternal-templates, explicit instantiations are treated the same
10604 as implicit ones. */
10605 if (flag_external_templates)
10606 return;
10608 if (!COMPLETE_TYPE_P (t))
10610 if (complain & tf_error)
10611 error ("explicit instantiation of `%#T' before definition of template",
10613 return;
10616 if (storage != NULL_TREE)
10618 if (pedantic && !in_system_header)
10619 pedwarn("ISO C++ forbids the use of `%s' on explicit instantiations",
10620 IDENTIFIER_POINTER (storage));
10622 if (storage == ridpointers[(int) RID_INLINE])
10623 nomem_p = 1;
10624 else if (storage == ridpointers[(int) RID_EXTERN])
10625 extern_p = 1;
10626 else if (storage == ridpointers[(int) RID_STATIC])
10627 static_p = 1;
10628 else
10630 error ("storage class `%D' applied to template instantiation",
10631 storage);
10632 extern_p = 0;
10636 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
10638 /* DR 259 [temp.spec].
10640 Both an explicit instantiation and a declaration of an explicit
10641 specialization shall not appear in a program unless the explicit
10642 instantiation follows a declaration of the explicit specialization.
10644 For a given set of template parameters, if an explicit
10645 instantiation of a template appears after a declaration of an
10646 explicit specialization for that template, the explicit
10647 instantiation has no effect. */
10648 return;
10650 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
10652 /* [temp.spec]
10654 No program shall explicitly instantiate any template more
10655 than once.
10657 If CLASSTYPE_INTERFACE_ONLY, then the first explicit instantiation
10658 was `extern'. If EXTERN_P then the second is. If -frepo, chances
10659 are we already got marked as an explicit instantiation because of the
10660 repo file. All these cases are OK. */
10661 if (!CLASSTYPE_INTERFACE_ONLY (t) && !extern_p && !flag_use_repository
10662 && (complain & tf_error))
10663 pedwarn ("duplicate explicit instantiation of `%#T'", t);
10665 /* If we've already instantiated the template, just return now. */
10666 if (!CLASSTYPE_INTERFACE_ONLY (t))
10667 return;
10670 mark_class_instantiated (t, extern_p);
10671 repo_template_instantiated (t, extern_p);
10673 if (nomem_p)
10674 return;
10677 tree tmp;
10679 /* In contrast to implicit instantiation, where only the
10680 declarations, and not the definitions, of members are
10681 instantiated, we have here:
10683 [temp.explicit]
10685 The explicit instantiation of a class template specialization
10686 implies the instantiation of all of its members not
10687 previously explicitly specialized in the translation unit
10688 containing the explicit instantiation.
10690 Of course, we can't instantiate member template classes, since
10691 we don't have any arguments for them. Note that the standard
10692 is unclear on whether the instantiation of the members are
10693 *explicit* instantiations or not. We choose to be generous,
10694 and not set DECL_EXPLICIT_INSTANTIATION. Therefore, we allow
10695 the explicit instantiation of a class where some of the members
10696 have no definition in the current translation unit. */
10698 if (! static_p)
10699 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
10700 if (TREE_CODE (tmp) == FUNCTION_DECL
10701 && DECL_TEMPLATE_INSTANTIATION (tmp))
10703 mark_decl_instantiated (tmp, extern_p);
10704 repo_template_instantiated (tmp, extern_p);
10705 if (! extern_p)
10706 instantiate_decl (tmp, /*defer_ok=*/1);
10709 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
10710 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
10712 mark_decl_instantiated (tmp, extern_p);
10713 repo_template_instantiated (tmp, extern_p);
10714 if (! extern_p)
10715 instantiate_decl (tmp, /*defer_ok=*/1);
10718 if (CLASSTYPE_NESTED_UTDS (t))
10719 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
10720 bt_instantiate_type_proc, &storage);
10724 /* Given a function DECL, which is a specialization of TMPL, modify
10725 DECL to be a re-instantiation of TMPL with the same template
10726 arguments. TMPL should be the template into which tsubst'ing
10727 should occur for DECL, not the most general template.
10729 One reason for doing this is a scenario like this:
10731 template <class T>
10732 void f(const T&, int i);
10734 void g() { f(3, 7); }
10736 template <class T>
10737 void f(const T& t, const int i) { }
10739 Note that when the template is first instantiated, with
10740 instantiate_template, the resulting DECL will have no name for the
10741 first parameter, and the wrong type for the second. So, when we go
10742 to instantiate the DECL, we regenerate it. */
10744 static void
10745 regenerate_decl_from_template (tree decl, tree tmpl)
10747 /* The most general version of TMPL. */
10748 tree gen_tmpl;
10749 /* The arguments used to instantiate DECL, from the most general
10750 template. */
10751 tree args;
10752 tree code_pattern;
10753 tree new_decl;
10754 bool unregistered;
10756 args = DECL_TI_ARGS (decl);
10757 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
10759 /* Unregister the specialization so that when we tsubst we will not
10760 just return DECL. We don't have to unregister DECL from TMPL
10761 because if would only be registered there if it were a partial
10762 instantiation of a specialization, which it isn't: it's a full
10763 instantiation. */
10764 gen_tmpl = most_general_template (tmpl);
10765 unregistered = reregister_specialization (decl, gen_tmpl,
10766 /*new_spec=*/NULL_TREE);
10768 /* If the DECL was not unregistered then something peculiar is
10769 happening: we created a specialization but did not call
10770 register_specialization for it. */
10771 my_friendly_assert (unregistered, 0);
10773 /* Make sure that we can see identifiers, and compute access
10774 correctly. */
10775 push_access_scope (decl);
10777 /* Do the substitution to get the new declaration. */
10778 new_decl = tsubst (code_pattern, args, tf_error, NULL_TREE);
10780 if (TREE_CODE (decl) == VAR_DECL)
10782 /* Set up DECL_INITIAL, since tsubst doesn't. */
10783 if (!DECL_INITIALIZED_IN_CLASS_P (decl))
10784 DECL_INITIAL (new_decl) =
10785 tsubst_expr (DECL_INITIAL (code_pattern), args,
10786 tf_error, DECL_TI_TEMPLATE (decl));
10788 else if (TREE_CODE (decl) == FUNCTION_DECL)
10790 /* Convince duplicate_decls to use the DECL_ARGUMENTS from the
10791 new decl. */
10792 DECL_INITIAL (new_decl) = error_mark_node;
10793 /* And don't complain about a duplicate definition. */
10794 DECL_INITIAL (decl) = NULL_TREE;
10797 pop_access_scope (decl);
10799 /* The immediate parent of the new template is still whatever it was
10800 before, even though tsubst sets DECL_TI_TEMPLATE up as the most
10801 general template. We also reset the DECL_ASSEMBLER_NAME since
10802 tsubst always calculates the name as if the function in question
10803 were really a template instance, and sometimes, with friend
10804 functions, this is not so. See tsubst_friend_function for
10805 details. */
10806 DECL_TI_TEMPLATE (new_decl) = DECL_TI_TEMPLATE (decl);
10807 COPY_DECL_ASSEMBLER_NAME (decl, new_decl);
10808 COPY_DECL_RTL (decl, new_decl);
10809 DECL_USE_TEMPLATE (new_decl) = DECL_USE_TEMPLATE (decl);
10811 /* Call duplicate decls to merge the old and new declarations. */
10812 duplicate_decls (new_decl, decl);
10814 /* Now, re-register the specialization. */
10815 register_specialization (decl, gen_tmpl, args);
10818 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
10819 substituted to get DECL. */
10821 tree
10822 template_for_substitution (tree decl)
10824 tree tmpl = DECL_TI_TEMPLATE (decl);
10826 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
10827 for the instantiation. This is not always the most general
10828 template. Consider, for example:
10830 template <class T>
10831 struct S { template <class U> void f();
10832 template <> void f<int>(); };
10834 and an instantiation of S<double>::f<int>. We want TD to be the
10835 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
10836 while (/* An instantiation cannot have a definition, so we need a
10837 more general template. */
10838 DECL_TEMPLATE_INSTANTIATION (tmpl)
10839 /* We must also deal with friend templates. Given:
10841 template <class T> struct S {
10842 template <class U> friend void f() {};
10845 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
10846 so far as the language is concerned, but that's still
10847 where we get the pattern for the instantiation from. On
10848 other hand, if the definition comes outside the class, say:
10850 template <class T> struct S {
10851 template <class U> friend void f();
10853 template <class U> friend void f() {}
10855 we don't need to look any further. That's what the check for
10856 DECL_INITIAL is for. */
10857 || (TREE_CODE (decl) == FUNCTION_DECL
10858 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
10859 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
10861 /* The present template, TD, should not be a definition. If it
10862 were a definition, we should be using it! Note that we
10863 cannot restructure the loop to just keep going until we find
10864 a template with a definition, since that might go too far if
10865 a specialization was declared, but not defined. */
10866 my_friendly_assert (!(TREE_CODE (decl) == VAR_DECL
10867 && !DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl))),
10868 0);
10870 /* Fetch the more general template. */
10871 tmpl = DECL_TI_TEMPLATE (tmpl);
10874 return tmpl;
10877 /* Produce the definition of D, a _DECL generated from a template. If
10878 DEFER_OK is nonzero, then we don't have to actually do the
10879 instantiation now; we just have to do it sometime. */
10881 tree
10882 instantiate_decl (tree d, int defer_ok)
10884 tree tmpl = DECL_TI_TEMPLATE (d);
10885 tree gen_args;
10886 tree args;
10887 tree td;
10888 tree code_pattern;
10889 tree spec;
10890 tree gen_tmpl;
10891 int pattern_defined;
10892 int need_push;
10893 location_t saved_loc = input_location;
10895 /* This function should only be used to instantiate templates for
10896 functions and static member variables. */
10897 my_friendly_assert (TREE_CODE (d) == FUNCTION_DECL
10898 || TREE_CODE (d) == VAR_DECL, 0);
10900 /* Variables are never deferred; if instantiation is required, they
10901 are instantiated right away. That allows for better code in the
10902 case that an expression refers to the value of the variable --
10903 if the variable has a constant value the referring expression can
10904 take advantage of that fact. */
10905 if (TREE_CODE (d) == VAR_DECL)
10906 defer_ok = 0;
10908 /* Don't instantiate cloned functions. Instead, instantiate the
10909 functions they cloned. */
10910 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
10911 d = DECL_CLONED_FUNCTION (d);
10913 if (DECL_TEMPLATE_INSTANTIATED (d))
10914 /* D has already been instantiated. It might seem reasonable to
10915 check whether or not D is an explicit instantiation, and, if so,
10916 stop here. But when an explicit instantiation is deferred
10917 until the end of the compilation, DECL_EXPLICIT_INSTANTIATION
10918 is set, even though we still need to do the instantiation. */
10919 return d;
10921 /* If we already have a specialization of this declaration, then
10922 there's no reason to instantiate it. Note that
10923 retrieve_specialization gives us both instantiations and
10924 specializations, so we must explicitly check
10925 DECL_TEMPLATE_SPECIALIZATION. */
10926 gen_tmpl = most_general_template (tmpl);
10927 gen_args = DECL_TI_ARGS (d);
10928 spec = retrieve_specialization (gen_tmpl, gen_args);
10929 if (spec != NULL_TREE && DECL_TEMPLATE_SPECIALIZATION (spec))
10930 return spec;
10932 /* This needs to happen before any tsubsting. */
10933 if (! push_tinst_level (d))
10934 return d;
10936 timevar_push (TV_PARSE);
10938 /* We may be in the middle of deferred access check. Disable it now. */
10939 push_deferring_access_checks (dk_no_deferred);
10941 /* Our caller does not expect collection to happen, which it might if
10942 we decide to compile the function to rtl now. Arrange for a new
10943 gc context to be created if so. */
10944 function_depth++;
10946 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
10947 for the instantiation. */
10948 td = template_for_substitution (d);
10949 code_pattern = DECL_TEMPLATE_RESULT (td);
10951 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
10952 || DECL_TEMPLATE_SPECIALIZATION (td))
10953 /* In the case of a friend template whose definition is provided
10954 outside the class, we may have too many arguments. Drop the
10955 ones we don't need. The same is true for specializations. */
10956 args = get_innermost_template_args
10957 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
10958 else
10959 args = gen_args;
10961 if (TREE_CODE (d) == FUNCTION_DECL)
10962 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
10963 else
10964 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
10966 input_location = DECL_SOURCE_LOCATION (d);
10968 if (pattern_defined)
10970 /* Let the repository code that this template definition is
10971 available.
10973 The repository doesn't need to know about cloned functions
10974 because they never actually show up in the object file. It
10975 does need to know about the clones; those are the symbols
10976 that the linker will be emitting error messages about. */
10977 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (d)
10978 || DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (d))
10980 tree t;
10982 for (t = TREE_CHAIN (d);
10983 t && DECL_CLONED_FUNCTION_P (t);
10984 t = TREE_CHAIN (t))
10985 repo_template_used (t);
10987 else
10988 repo_template_used (d);
10990 if (flag_external_templates && ! DECL_INTERFACE_KNOWN (d))
10992 if (flag_alt_external_templates)
10994 if (interface_unknown)
10995 warn_if_unknown_interface (d);
10997 else if (DECL_INTERFACE_KNOWN (code_pattern))
10999 DECL_INTERFACE_KNOWN (d) = 1;
11000 DECL_NOT_REALLY_EXTERN (d) = ! DECL_EXTERNAL (code_pattern);
11002 else
11003 warn_if_unknown_interface (code_pattern);
11006 if (at_eof)
11007 import_export_decl (d);
11010 if (!defer_ok)
11012 /* Recheck the substitutions to obtain any warning messages
11013 about ignoring cv qualifiers. */
11014 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
11015 tree type = TREE_TYPE (gen);
11017 /* Make sure that we can see identifiers, and compute access
11018 correctly. D is already the target FUNCTION_DECL with the
11019 right context. */
11020 push_access_scope (d);
11022 if (TREE_CODE (gen) == FUNCTION_DECL)
11024 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_error | tf_warning, d);
11025 tsubst (TYPE_RAISES_EXCEPTIONS (type), gen_args,
11026 tf_error | tf_warning, d);
11027 /* Don't simply tsubst the function type, as that will give
11028 duplicate warnings about poor parameter qualifications.
11029 The function arguments are the same as the decl_arguments
11030 without the top level cv qualifiers. */
11031 type = TREE_TYPE (type);
11033 tsubst (type, gen_args, tf_error | tf_warning, d);
11035 pop_access_scope (d);
11038 if (TREE_CODE (d) == VAR_DECL && DECL_INITIALIZED_IN_CLASS_P (d)
11039 && DECL_INITIAL (d) == NULL_TREE)
11040 /* We should have set up DECL_INITIAL in instantiate_class_template. */
11041 abort ();
11042 /* Reject all external templates except inline functions. */
11043 else if (DECL_INTERFACE_KNOWN (d)
11044 && ! DECL_NOT_REALLY_EXTERN (d)
11045 && ! (TREE_CODE (d) == FUNCTION_DECL
11046 && DECL_INLINE (d)))
11047 goto out;
11048 /* Defer all other templates, unless we have been explicitly
11049 forbidden from doing so. We restore the source position here
11050 because it's used by add_pending_template. */
11051 else if (! pattern_defined || defer_ok)
11053 input_location = saved_loc;
11055 if (at_eof && !pattern_defined
11056 && DECL_EXPLICIT_INSTANTIATION (d))
11057 /* [temp.explicit]
11059 The definition of a non-exported function template, a
11060 non-exported member function template, or a non-exported
11061 member function or static data member of a class template
11062 shall be present in every translation unit in which it is
11063 explicitly instantiated. */
11064 pedwarn
11065 ("explicit instantiation of `%D' but no definition available", d);
11067 add_pending_template (d);
11068 goto out;
11071 need_push = !global_bindings_p ();
11072 if (need_push)
11073 push_to_top_level ();
11075 /* Regenerate the declaration in case the template has been modified
11076 by a subsequent redeclaration. */
11077 regenerate_decl_from_template (d, td);
11079 /* We already set the file and line above. Reset them now in case
11080 they changed as a result of calling
11081 regenerate_decl_from_template. */
11082 input_location = DECL_SOURCE_LOCATION (d);
11084 if (TREE_CODE (d) == VAR_DECL)
11086 /* Clear out DECL_RTL; whatever was there before may not be right
11087 since we've reset the type of the declaration. */
11088 SET_DECL_RTL (d, NULL_RTX);
11090 DECL_IN_AGGR_P (d) = 0;
11091 import_export_decl (d);
11092 DECL_EXTERNAL (d) = ! DECL_NOT_REALLY_EXTERN (d);
11094 if (DECL_EXTERNAL (d))
11096 /* The fact that this code is executing indicates that:
11098 (1) D is a template static data member, for which a
11099 definition is available.
11101 (2) An implicit or explicit instantiation has occurred.
11103 (3) We are not going to emit a definition of the static
11104 data member at this time.
11106 This situation is peculiar, but it occurs on platforms
11107 without weak symbols when performing an implicit
11108 instantiation. There, we cannot implicitly instantiate a
11109 defined static data member in more than one translation
11110 unit, so import_export_decl marks the declaration as
11111 external; we must rely on explicit instantiation. */
11113 else
11115 /* Mark D as instantiated so that recursive calls to
11116 instantiate_decl do not try to instantiate it again. */
11117 DECL_TEMPLATE_INSTANTIATED (d) = 1;
11118 cp_finish_decl (d,
11119 (!DECL_INITIALIZED_IN_CLASS_P (d)
11120 ? DECL_INITIAL (d) : NULL_TREE),
11121 NULL_TREE, 0);
11124 else if (TREE_CODE (d) == FUNCTION_DECL)
11126 htab_t saved_local_specializations;
11127 tree subst_decl;
11128 tree tmpl_parm;
11129 tree spec_parm;
11131 /* Mark D as instantiated so that recursive calls to
11132 instantiate_decl do not try to instantiate it again. */
11133 DECL_TEMPLATE_INSTANTIATED (d) = 1;
11135 /* Save away the current list, in case we are instantiating one
11136 template from within the body of another. */
11137 saved_local_specializations = local_specializations;
11139 /* Set up the list of local specializations. */
11140 local_specializations = htab_create (37,
11141 hash_local_specialization,
11142 eq_local_specializations,
11143 NULL);
11145 /* Set up context. */
11146 import_export_decl (d);
11147 start_function (NULL_TREE, d, NULL_TREE, SF_PRE_PARSED);
11149 /* Create substitution entries for the parameters. */
11150 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
11151 tmpl_parm = DECL_ARGUMENTS (subst_decl);
11152 spec_parm = DECL_ARGUMENTS (d);
11153 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
11155 register_local_specialization (spec_parm, tmpl_parm);
11156 spec_parm = skip_artificial_parms_for (d, spec_parm);
11157 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
11159 while (tmpl_parm)
11161 register_local_specialization (spec_parm, tmpl_parm);
11162 tmpl_parm = TREE_CHAIN (tmpl_parm);
11163 spec_parm = TREE_CHAIN (spec_parm);
11165 my_friendly_assert (!spec_parm, 20020813);
11167 /* Substitute into the body of the function. */
11168 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
11169 tf_error | tf_warning, tmpl);
11171 /* We don't need the local specializations any more. */
11172 htab_delete (local_specializations);
11173 local_specializations = saved_local_specializations;
11175 /* Finish the function. */
11176 d = finish_function (0);
11177 expand_or_defer_fn (d);
11180 /* We're not deferring instantiation any more. */
11181 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
11183 if (need_push)
11184 pop_from_top_level ();
11186 out:
11187 input_location = saved_loc;
11188 pop_deferring_access_checks ();
11189 pop_tinst_level ();
11190 function_depth--;
11192 timevar_pop (TV_PARSE);
11194 return d;
11197 /* Run through the list of templates that we wish we could
11198 instantiate, and instantiate any we can. */
11201 instantiate_pending_templates (void)
11203 tree *t;
11204 tree last = NULL_TREE;
11205 int instantiated_something = 0;
11206 int reconsider;
11207 location_t saved_loc = input_location;
11211 reconsider = 0;
11213 t = &pending_templates;
11214 while (*t)
11216 tree instantiation = TREE_VALUE (*t);
11218 reopen_tinst_level (TREE_PURPOSE (*t));
11220 if (TYPE_P (instantiation))
11222 tree fn;
11224 if (!COMPLETE_TYPE_P (instantiation))
11226 instantiate_class_template (instantiation);
11227 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
11228 for (fn = TYPE_METHODS (instantiation);
11230 fn = TREE_CHAIN (fn))
11231 if (! DECL_ARTIFICIAL (fn))
11232 instantiate_decl (fn, /*defer_ok=*/0);
11233 if (COMPLETE_TYPE_P (instantiation))
11235 instantiated_something = 1;
11236 reconsider = 1;
11240 if (COMPLETE_TYPE_P (instantiation))
11241 /* If INSTANTIATION has been instantiated, then we don't
11242 need to consider it again in the future. */
11243 *t = TREE_CHAIN (*t);
11244 else
11246 last = *t;
11247 t = &TREE_CHAIN (*t);
11250 else
11252 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
11253 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
11255 instantiation = instantiate_decl (instantiation,
11256 /*defer_ok=*/0);
11257 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
11259 instantiated_something = 1;
11260 reconsider = 1;
11264 if (DECL_TEMPLATE_SPECIALIZATION (instantiation)
11265 || DECL_TEMPLATE_INSTANTIATED (instantiation))
11266 /* If INSTANTIATION has been instantiated, then we don't
11267 need to consider it again in the future. */
11268 *t = TREE_CHAIN (*t);
11269 else
11271 last = *t;
11272 t = &TREE_CHAIN (*t);
11275 tinst_depth = 0;
11276 current_tinst_level = NULL_TREE;
11278 last_pending_template = last;
11280 while (reconsider);
11282 input_location = saved_loc;
11283 return instantiated_something;
11286 /* Substitute ARGVEC into T, which is a list of initializers for
11287 either base class or a non-static data member. The TREE_PURPOSEs
11288 are DECLs, and the TREE_VALUEs are the initializer values. Used by
11289 instantiate_decl. */
11291 static tree
11292 tsubst_initializer_list (tree t, tree argvec)
11294 tree inits = NULL_TREE;
11296 for (; t; t = TREE_CHAIN (t))
11298 tree decl;
11299 tree init;
11300 tree val;
11302 decl = tsubst_copy (TREE_PURPOSE (t), argvec, tf_error | tf_warning,
11303 NULL_TREE);
11304 decl = expand_member_init (decl);
11305 if (decl && !DECL_P (decl))
11306 in_base_initializer = 1;
11308 init = tsubst_expr (TREE_VALUE (t), argvec, tf_error | tf_warning,
11309 NULL_TREE);
11310 if (!init)
11312 else if (TREE_CODE (init) == TREE_LIST)
11313 for (val = init; val; val = TREE_CHAIN (val))
11314 TREE_VALUE (val) = convert_from_reference (TREE_VALUE (val));
11315 else if (init != void_type_node)
11316 init = convert_from_reference (init);
11318 in_base_initializer = 0;
11320 if (decl)
11322 init = build_tree_list (decl, init);
11323 TREE_CHAIN (init) = inits;
11324 inits = init;
11327 return inits;
11330 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
11332 static void
11333 set_current_access_from_decl (tree decl)
11335 if (TREE_PRIVATE (decl))
11336 current_access_specifier = access_private_node;
11337 else if (TREE_PROTECTED (decl))
11338 current_access_specifier = access_protected_node;
11339 else
11340 current_access_specifier = access_public_node;
11343 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
11344 is the instantiation (which should have been created with
11345 start_enum) and ARGS are the template arguments to use. */
11347 static void
11348 tsubst_enum (tree tag, tree newtag, tree args)
11350 tree e;
11352 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
11354 tree value;
11355 tree decl;
11357 decl = TREE_VALUE (e);
11358 /* Note that in a template enum, the TREE_VALUE is the
11359 CONST_DECL, not the corresponding INTEGER_CST. */
11360 value = tsubst_expr (DECL_INITIAL (decl),
11361 args, tf_error | tf_warning,
11362 NULL_TREE);
11364 /* Give this enumeration constant the correct access. */
11365 set_current_access_from_decl (decl);
11367 /* Actually build the enumerator itself. */
11368 build_enumerator (DECL_NAME (decl), value, newtag);
11371 finish_enum (newtag);
11372 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
11373 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
11376 /* DECL is a FUNCTION_DECL that is a template specialization. Return
11377 its type -- but without substituting the innermost set of template
11378 arguments. So, innermost set of template parameters will appear in
11379 the type. */
11381 tree
11382 get_mostly_instantiated_function_type (tree decl)
11384 tree fn_type;
11385 tree tmpl;
11386 tree targs;
11387 tree tparms;
11388 int parm_depth;
11390 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11391 targs = DECL_TI_ARGS (decl);
11392 tparms = DECL_TEMPLATE_PARMS (tmpl);
11393 parm_depth = TMPL_PARMS_DEPTH (tparms);
11395 /* There should be as many levels of arguments as there are levels
11396 of parameters. */
11397 my_friendly_assert (parm_depth == TMPL_ARGS_DEPTH (targs), 0);
11399 fn_type = TREE_TYPE (tmpl);
11401 if (parm_depth == 1)
11402 /* No substitution is necessary. */
11404 else
11406 int i;
11407 tree partial_args;
11409 /* Replace the innermost level of the TARGS with NULL_TREEs to
11410 let tsubst know not to substitute for those parameters. */
11411 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
11412 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
11413 SET_TMPL_ARGS_LEVEL (partial_args, i,
11414 TMPL_ARGS_LEVEL (targs, i));
11415 SET_TMPL_ARGS_LEVEL (partial_args,
11416 TMPL_ARGS_DEPTH (targs),
11417 make_tree_vec (DECL_NTPARMS (tmpl)));
11419 /* Make sure that we can see identifiers, and compute access
11420 correctly. We can just use the context of DECL for the
11421 partial substitution here. It depends only on outer template
11422 parameters, regardless of whether the innermost level is
11423 specialized or not. */
11424 push_access_scope (decl);
11426 ++processing_template_decl;
11427 /* Now, do the (partial) substitution to figure out the
11428 appropriate function type. */
11429 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
11430 --processing_template_decl;
11432 /* Substitute into the template parameters to obtain the real
11433 innermost set of parameters. This step is important if the
11434 innermost set of template parameters contains value
11435 parameters whose types depend on outer template parameters. */
11436 TREE_VEC_LENGTH (partial_args)--;
11437 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
11439 pop_access_scope (decl);
11442 return fn_type;
11445 /* Return truthvalue if we're processing a template different from
11446 the last one involved in diagnostics. */
11448 problematic_instantiation_changed (void)
11450 return last_template_error_tick != tinst_level_tick;
11453 /* Remember current template involved in diagnostics. */
11454 void
11455 record_last_problematic_instantiation (void)
11457 last_template_error_tick = tinst_level_tick;
11460 tree
11461 current_instantiation (void)
11463 return current_tinst_level;
11466 /* [temp.param] Check that template non-type parm TYPE is of an allowable
11467 type. Return zero for ok, nonzero for disallowed. Issue error and
11468 warning messages under control of COMPLAIN. */
11470 static int
11471 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
11473 if (INTEGRAL_TYPE_P (type))
11474 return 0;
11475 else if (POINTER_TYPE_P (type))
11476 return 0;
11477 else if (TYPE_PTR_TO_MEMBER_P (type))
11478 return 0;
11479 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
11480 return 0;
11481 else if (TREE_CODE (type) == TYPENAME_TYPE)
11482 return 0;
11484 if (complain & tf_error)
11485 error ("`%#T' is not a valid type for a template constant parameter",
11486 type);
11487 return 1;
11490 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
11491 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
11493 static bool
11494 dependent_type_p_r (tree type)
11496 tree scope;
11498 /* [temp.dep.type]
11500 A type is dependent if it is:
11502 -- a template parameter. */
11503 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
11504 return true;
11505 /* -- a qualified-id with a nested-name-specifier which contains a
11506 class-name that names a dependent type or whose unqualified-id
11507 names a dependent type. */
11508 if (TREE_CODE (type) == TYPENAME_TYPE)
11509 return true;
11510 /* -- a cv-qualified type where the cv-unqualified type is
11511 dependent. */
11512 type = TYPE_MAIN_VARIANT (type);
11513 /* -- a compound type constructed from any dependent type. */
11514 if (TYPE_PTR_TO_MEMBER_P (type))
11515 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
11516 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
11517 (type)));
11518 else if (TREE_CODE (type) == POINTER_TYPE
11519 || TREE_CODE (type) == REFERENCE_TYPE)
11520 return dependent_type_p (TREE_TYPE (type));
11521 else if (TREE_CODE (type) == FUNCTION_TYPE
11522 || TREE_CODE (type) == METHOD_TYPE)
11524 tree arg_type;
11526 if (dependent_type_p (TREE_TYPE (type)))
11527 return true;
11528 for (arg_type = TYPE_ARG_TYPES (type);
11529 arg_type;
11530 arg_type = TREE_CHAIN (arg_type))
11531 if (dependent_type_p (TREE_VALUE (arg_type)))
11532 return true;
11533 return false;
11535 /* -- an array type constructed from any dependent type or whose
11536 size is specified by a constant expression that is
11537 value-dependent. */
11538 if (TREE_CODE (type) == ARRAY_TYPE)
11540 if (TYPE_DOMAIN (type)
11541 && ((value_dependent_expression_p
11542 (TYPE_MAX_VALUE (TYPE_DOMAIN (type))))
11543 || (type_dependent_expression_p
11544 (TYPE_MAX_VALUE (TYPE_DOMAIN (type))))))
11545 return true;
11546 return dependent_type_p (TREE_TYPE (type));
11549 /* -- a template-id in which either the template name is a template
11550 parameter ... */
11551 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
11552 return true;
11553 /* ... or any of the template arguments is a dependent type or
11554 an expression that is type-dependent or value-dependent. */
11555 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
11556 && (any_dependent_template_arguments_p
11557 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
11558 return true;
11560 /* All TYPEOF_TYPEs are dependent; if the argument of the `typeof'
11561 expression is not type-dependent, then it should already been
11562 have resolved. */
11563 if (TREE_CODE (type) == TYPEOF_TYPE)
11564 return true;
11566 /* The standard does not specifically mention types that are local
11567 to template functions or local classes, but they should be
11568 considered dependent too. For example:
11570 template <int I> void f() {
11571 enum E { a = I };
11572 S<sizeof (E)> s;
11575 The size of `E' cannot be known until the value of `I' has been
11576 determined. Therefore, `E' must be considered dependent. */
11577 scope = TYPE_CONTEXT (type);
11578 if (scope && TYPE_P (scope))
11579 return dependent_type_p (scope);
11580 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
11581 return type_dependent_expression_p (scope);
11583 /* Other types are non-dependent. */
11584 return false;
11587 /* Returns TRUE if TYPE is dependent, in the sense of
11588 [temp.dep.type]. */
11590 bool
11591 dependent_type_p (tree type)
11593 /* If there are no template parameters in scope, then there can't be
11594 any dependent types. */
11595 if (!processing_template_decl)
11596 return false;
11598 /* If the type is NULL, we have not computed a type for the entity
11599 in question; in that case, the type is dependent. */
11600 if (!type)
11601 return true;
11603 /* Erroneous types can be considered non-dependent. */
11604 if (type == error_mark_node)
11605 return false;
11607 /* If we have not already computed the appropriate value for TYPE,
11608 do so now. */
11609 if (!TYPE_DEPENDENT_P_VALID (type))
11611 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
11612 TYPE_DEPENDENT_P_VALID (type) = 1;
11615 return TYPE_DEPENDENT_P (type);
11618 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
11620 static bool
11621 dependent_scope_ref_p (tree expression, bool criterion (tree))
11623 tree scope;
11624 tree name;
11626 my_friendly_assert (TREE_CODE (expression) == SCOPE_REF, 20030714);
11628 if (!TYPE_P (TREE_OPERAND (expression, 0)))
11629 return true;
11631 scope = TREE_OPERAND (expression, 0);
11632 name = TREE_OPERAND (expression, 1);
11634 /* [temp.dep.expr]
11636 An id-expression is type-dependent if it contains a
11637 nested-name-specifier that contains a class-name that names a
11638 dependent type. */
11639 /* The suggested resolution to Core Issue 2 implies that if the
11640 qualifying type is the current class, then we must peek
11641 inside it. */
11642 if (DECL_P (name)
11643 && currently_open_class (scope)
11644 && !criterion (name))
11645 return false;
11646 if (dependent_type_p (scope))
11647 return true;
11649 return false;
11652 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
11653 [temp.dep.constexpr] */
11655 bool
11656 value_dependent_expression_p (tree expression)
11658 if (!processing_template_decl)
11659 return false;
11661 /* A name declared with a dependent type. */
11662 if (TREE_CODE (expression) == IDENTIFIER_NODE
11663 || (DECL_P (expression)
11664 && type_dependent_expression_p (expression)))
11665 return true;
11666 /* A non-type template parameter. */
11667 if ((TREE_CODE (expression) == CONST_DECL
11668 && DECL_TEMPLATE_PARM_P (expression))
11669 || TREE_CODE (expression) == TEMPLATE_PARM_INDEX)
11670 return true;
11671 /* A constant with integral or enumeration type and is initialized
11672 with an expression that is value-dependent. */
11673 if (TREE_CODE (expression) == VAR_DECL
11674 && DECL_INITIAL (expression)
11675 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
11676 && value_dependent_expression_p (DECL_INITIAL (expression)))
11677 return true;
11678 /* These expressions are value-dependent if the type to which the
11679 cast occurs is dependent or the expression being casted is
11680 value-dependent. */
11681 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
11682 || TREE_CODE (expression) == STATIC_CAST_EXPR
11683 || TREE_CODE (expression) == CONST_CAST_EXPR
11684 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
11685 || TREE_CODE (expression) == CAST_EXPR)
11687 if (dependent_type_p (TREE_TYPE (expression)))
11688 return true;
11689 /* A functional cast has a list of operands. */
11690 expression = TREE_OPERAND (expression, 0);
11691 if (TREE_CODE (expression) == TREE_LIST)
11695 if (value_dependent_expression_p (TREE_VALUE (expression)))
11696 return true;
11697 expression = TREE_CHAIN (expression);
11699 while (expression);
11700 return false;
11702 else
11703 return value_dependent_expression_p (expression);
11705 /* A `sizeof' expression is value-dependent if the operand is
11706 type-dependent. */
11707 if (TREE_CODE (expression) == SIZEOF_EXPR
11708 || TREE_CODE (expression) == ALIGNOF_EXPR)
11710 expression = TREE_OPERAND (expression, 0);
11711 if (TYPE_P (expression))
11712 return dependent_type_p (expression);
11713 return type_dependent_expression_p (expression);
11715 if (TREE_CODE (expression) == SCOPE_REF)
11716 return dependent_scope_ref_p (expression, value_dependent_expression_p);
11717 if (TREE_CODE (expression) == COMPONENT_REF)
11718 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
11719 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
11720 /* A constant expression is value-dependent if any subexpression is
11721 value-dependent. */
11722 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (expression))))
11724 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
11726 case '1':
11727 return (value_dependent_expression_p
11728 (TREE_OPERAND (expression, 0)));
11729 case '<':
11730 case '2':
11731 return ((value_dependent_expression_p
11732 (TREE_OPERAND (expression, 0)))
11733 || (value_dependent_expression_p
11734 (TREE_OPERAND (expression, 1))));
11735 case 'e':
11737 int i;
11738 for (i = 0; i < first_rtl_op (TREE_CODE (expression)); ++i)
11739 /* In some cases, some of the operands may be missing.
11740 (For example, in the case of PREDECREMENT_EXPR, the
11741 amount to increment by may be missing.) That doesn't
11742 make the expression dependent. */
11743 if (TREE_OPERAND (expression, i)
11744 && (value_dependent_expression_p
11745 (TREE_OPERAND (expression, i))))
11746 return true;
11747 return false;
11752 /* The expression is not value-dependent. */
11753 return false;
11756 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
11757 [temp.dep.expr]. */
11759 bool
11760 type_dependent_expression_p (tree expression)
11762 if (!processing_template_decl)
11763 return false;
11765 if (expression == error_mark_node)
11766 return false;
11768 /* An unresolved name is always dependent. */
11769 if (TREE_CODE (expression) == IDENTIFIER_NODE)
11770 return true;
11772 /* Some expression forms are never type-dependent. */
11773 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
11774 || TREE_CODE (expression) == SIZEOF_EXPR
11775 || TREE_CODE (expression) == ALIGNOF_EXPR
11776 || TREE_CODE (expression) == TYPEID_EXPR
11777 || TREE_CODE (expression) == DELETE_EXPR
11778 || TREE_CODE (expression) == VEC_DELETE_EXPR
11779 || TREE_CODE (expression) == THROW_EXPR)
11780 return false;
11782 /* The types of these expressions depends only on the type to which
11783 the cast occurs. */
11784 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
11785 || TREE_CODE (expression) == STATIC_CAST_EXPR
11786 || TREE_CODE (expression) == CONST_CAST_EXPR
11787 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
11788 || TREE_CODE (expression) == CAST_EXPR)
11789 return dependent_type_p (TREE_TYPE (expression));
11791 /* The types of these expressions depends only on the type created
11792 by the expression. */
11793 if (TREE_CODE (expression) == NEW_EXPR
11794 || TREE_CODE (expression) == VEC_NEW_EXPR)
11796 /* For NEW_EXPR tree nodes created inside a template, either
11797 the object type itself or a TREE_LIST may appear as the
11798 operand 1. */
11799 tree type = TREE_OPERAND (expression, 1);
11800 if (TREE_CODE (type) == TREE_LIST)
11801 /* This is an array type. We need to check array dimensions
11802 as well. */
11803 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
11804 || value_dependent_expression_p
11805 (TREE_OPERAND (TREE_VALUE (type), 1));
11806 else
11807 return dependent_type_p (type);
11810 if (TREE_CODE (expression) == SCOPE_REF
11811 && dependent_scope_ref_p (expression,
11812 type_dependent_expression_p))
11813 return true;
11815 if (TREE_CODE (expression) == FUNCTION_DECL
11816 && DECL_LANG_SPECIFIC (expression)
11817 && DECL_TEMPLATE_INFO (expression)
11818 && (any_dependent_template_arguments_p
11819 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
11820 return true;
11822 if (TREE_TYPE (expression) == unknown_type_node)
11824 if (TREE_CODE (expression) == ADDR_EXPR)
11825 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
11826 if (TREE_CODE (expression) == COMPONENT_REF)
11828 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
11829 return true;
11830 expression = TREE_OPERAND (expression, 1);
11831 if (TREE_CODE (expression) == IDENTIFIER_NODE)
11832 return false;
11835 if (TREE_CODE (expression) == BASELINK)
11836 expression = BASELINK_FUNCTIONS (expression);
11837 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
11839 if (any_dependent_template_arguments_p
11840 (TREE_OPERAND (expression, 1)))
11841 return true;
11842 expression = TREE_OPERAND (expression, 0);
11844 if (TREE_CODE (expression) == OVERLOAD)
11846 while (expression)
11848 if (type_dependent_expression_p (OVL_CURRENT (expression)))
11849 return true;
11850 expression = OVL_NEXT (expression);
11852 return false;
11854 abort ();
11857 return (dependent_type_p (TREE_TYPE (expression)));
11860 /* Returns TRUE if ARGS (a TREE_LIST of arguments to a function call)
11861 contains a type-dependent expression. */
11863 bool
11864 any_type_dependent_arguments_p (tree args)
11866 while (args)
11868 tree arg = TREE_VALUE (args);
11870 if (type_dependent_expression_p (arg))
11871 return true;
11872 args = TREE_CHAIN (args);
11874 return false;
11877 /* Returns TRUE if the ARG (a template argument) is dependent. */
11879 static bool
11880 dependent_template_arg_p (tree arg)
11882 if (!processing_template_decl)
11883 return false;
11885 if (TREE_CODE (arg) == TEMPLATE_DECL
11886 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11887 return dependent_template_p (arg);
11888 else if (TYPE_P (arg))
11889 return dependent_type_p (arg);
11890 else
11891 return (type_dependent_expression_p (arg)
11892 || value_dependent_expression_p (arg));
11895 /* Returns true if ARGS (a collection of template arguments) contains
11896 any dependent arguments. */
11898 bool
11899 any_dependent_template_arguments_p (tree args)
11901 int i;
11903 if (!args)
11904 return false;
11906 for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
11907 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
11908 return true;
11910 return false;
11913 /* Returns TRUE if the template TMPL is dependent. */
11915 bool
11916 dependent_template_p (tree tmpl)
11918 /* Template template parameters are dependent. */
11919 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
11920 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
11921 return true;
11922 /* So are qualified names that have not been looked up. */
11923 if (TREE_CODE (tmpl) == SCOPE_REF)
11924 return true;
11925 /* So are member templates of dependent classes. */
11926 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
11927 return dependent_type_p (DECL_CONTEXT (tmpl));
11928 return false;
11931 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
11933 bool
11934 dependent_template_id_p (tree tmpl, tree args)
11936 return (dependent_template_p (tmpl)
11937 || any_dependent_template_arguments_p (args));
11940 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
11941 TYPENAME_TYPE corresponds. Returns ERROR_MARK_NODE if no such TYPE
11942 can be found. Note that this function peers inside uninstantiated
11943 templates and therefore should be used only in extremely limited
11944 situations. */
11946 tree
11947 resolve_typename_type (tree type, bool only_current_p)
11949 tree scope;
11950 tree name;
11951 tree decl;
11952 int quals;
11954 my_friendly_assert (TREE_CODE (type) == TYPENAME_TYPE,
11955 20010702);
11957 scope = TYPE_CONTEXT (type);
11958 name = TYPE_IDENTIFIER (type);
11960 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
11961 it first before we can figure out what NAME refers to. */
11962 if (TREE_CODE (scope) == TYPENAME_TYPE)
11963 scope = resolve_typename_type (scope, only_current_p);
11964 /* If we don't know what SCOPE refers to, then we cannot resolve the
11965 TYPENAME_TYPE. */
11966 if (scope == error_mark_node || TREE_CODE (scope) == TYPENAME_TYPE)
11967 return error_mark_node;
11968 /* If the SCOPE is a template type parameter, we have no way of
11969 resolving the name. */
11970 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
11971 return type;
11972 /* If the SCOPE is not the current instantiation, there's no reason
11973 to look inside it. */
11974 if (only_current_p && !currently_open_class (scope))
11975 return error_mark_node;
11976 /* If SCOPE is a partial instantiation, it will not have a valid
11977 TYPE_FIELDS list, so use the original template. */
11978 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
11979 /* Enter the SCOPE so that name lookup will be resolved as if we
11980 were in the class definition. In particular, SCOPE will no
11981 longer be considered a dependent type. */
11982 push_scope (scope);
11983 /* Look up the declaration. */
11984 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
11985 /* Obtain the set of qualifiers applied to the TYPE. */
11986 quals = cp_type_quals (type);
11987 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
11988 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
11989 if (!decl)
11990 type = error_mark_node;
11991 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
11992 && TREE_CODE (decl) == TYPE_DECL)
11993 type = TREE_TYPE (decl);
11994 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
11995 && DECL_CLASS_TEMPLATE_P (decl))
11997 tree tmpl;
11998 tree args;
11999 /* Obtain the template and the arguments. */
12000 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
12001 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
12002 /* Instantiate the template. */
12003 type = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
12004 /*entering_scope=*/0, tf_error | tf_user);
12006 else
12007 type = error_mark_node;
12008 /* Qualify the resulting type. */
12009 if (type != error_mark_node && quals)
12010 type = cp_build_qualified_type (type, quals);
12011 /* Leave the SCOPE. */
12012 pop_scope (scope);
12014 return type;
12017 /* EXPR is an expression which is not type-dependent. Return a proxy
12018 for EXPR that can be used to compute the types of larger
12019 expressions containing EXPR. */
12021 tree
12022 build_non_dependent_expr (tree expr)
12024 /* Preserve null pointer constants so that the type of things like
12025 "p == 0" where "p" is a pointer can be determined. */
12026 if (null_ptr_cst_p (expr))
12027 return expr;
12028 /* Preserve OVERLOADs; the functions must be available to resolve
12029 types. */
12030 if (TREE_CODE (expr) == OVERLOAD)
12031 return expr;
12032 /* Preserve string constants; conversions from string constants to
12033 "char *" are allowed, even though normally a "const char *"
12034 cannot be used to initialize a "char *". */
12035 if (TREE_CODE (expr) == STRING_CST)
12036 return expr;
12038 if (TREE_CODE (expr) == COND_EXPR)
12039 return build (COND_EXPR,
12040 TREE_TYPE (expr),
12041 TREE_OPERAND (expr, 0),
12042 (TREE_OPERAND (expr, 1)
12043 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
12044 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
12045 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
12046 if (TREE_CODE (expr) == COMPOUND_EXPR
12047 && !COMPOUND_EXPR_OVERLOADED (expr))
12048 return build (COMPOUND_EXPR,
12049 TREE_TYPE (expr),
12050 TREE_OPERAND (expr, 0),
12051 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
12053 /* Otherwise, build a NON_DEPENDENT_EXPR.
12055 REFERENCE_TYPEs are not stripped for expressions in templates
12056 because doing so would play havoc with mangling. Consider, for
12057 example:
12059 template <typename T> void f<T& g>() { g(); }
12061 In the body of "f", the expression for "g" will have
12062 REFERENCE_TYPE, even though the standard says that it should
12063 not. The reason is that we must preserve the syntactic form of
12064 the expression so that mangling (say) "f<g>" inside the body of
12065 "f" works out correctly. Therefore, the REFERENCE_TYPE is
12066 stripped here. */
12067 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
12070 /* ARGS is a TREE_LIST of expressions as arguments to a function call.
12071 Return a new TREE_LIST with the various arguments replaced with
12072 equivalent non-dependent expressions. */
12074 tree
12075 build_non_dependent_args (tree args)
12077 tree a;
12078 tree new_args;
12080 new_args = NULL_TREE;
12081 for (a = args; a; a = TREE_CHAIN (a))
12082 new_args = tree_cons (NULL_TREE,
12083 build_non_dependent_expr (TREE_VALUE (a)),
12084 new_args);
12085 return nreverse (new_args);
12088 #include "gt-cp-pt.h"