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)
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". */
31 #include "coretypes.h"
37 #include "tree-inline.h"
46 /* The type of functions taking a tree, and some additional data, and
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
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
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);
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,
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). */
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));
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
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))
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. */
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)
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);
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);
255 error ("invalid member template declaration `%D'", decl);
257 return error_mark_node;
260 /* Returns the template nesting level of the indicated class TYPE.
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
275 This function is guaranteed to return 0 if passed NULL_TREE so
276 that, for example, `template_class_depth (current_class_type)' is
280 template_class_depth_real (tree type, int count_specializations)
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))))
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))))
312 /* Returns the template nesting level of the indicated class TYPE.
313 Like template_class_depth_real, but instantiations do not count in
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. */
326 inline_needs_template_parms (tree decl)
328 if (! DECL_TEMPLATE_INFO (decl))
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
341 push_inline_template_parms_recursive (tree parmlist, int levels)
343 tree parms = TREE_VALUE (parmlist);
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;
356 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
358 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
359 my_friendly_assert (DECL_P (parm), 0);
361 switch (TREE_CODE (parm))
370 /* Make a CONST_DECL as is done in process_template_parm.
371 It is ugly that we recreate this here; the original
372 version built in process_template_parm is no longer
374 tree decl = build_decl (CONST_DECL, DECL_NAME (parm),
376 DECL_ARTIFICIAL (decl) = 1;
377 TREE_CONSTANT (decl) = TREE_READONLY (decl) = 1;
378 DECL_INITIAL (decl) = DECL_INITIAL (parm);
379 SET_DECL_TEMPLATE_PARM_P (decl);
390 /* Restore the template parameter context for a member template or
391 a friend template defined in a class definition. */
394 maybe_begin_member_template_processing (tree decl)
399 if (inline_needs_template_parms (decl))
401 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
402 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
404 if (DECL_TEMPLATE_SPECIALIZATION (decl))
407 parms = TREE_CHAIN (parms);
410 push_inline_template_parms_recursive (parms, levels);
413 /* Remember how many levels of template parameters we pushed so that
414 we can pop them later. */
415 if (!inline_parm_levels)
416 VARRAY_INT_INIT (inline_parm_levels, 4, "inline_parm_levels");
417 if (inline_parm_levels_used == inline_parm_levels->num_elements)
418 VARRAY_GROW (inline_parm_levels, 2 * inline_parm_levels_used);
419 VARRAY_INT (inline_parm_levels, inline_parm_levels_used) = levels;
420 ++inline_parm_levels_used;
423 /* Undo the effects of begin_member_template_processing. */
426 maybe_end_member_template_processing (void)
430 if (!inline_parm_levels_used)
433 --inline_parm_levels_used;
435 i < VARRAY_INT (inline_parm_levels, inline_parm_levels_used);
438 --processing_template_decl;
439 current_template_parms = TREE_CHAIN (current_template_parms);
444 /* Returns nonzero iff T is a member template function. We must be
447 template <class T> class C { void f(); }
449 Here, f is a template function, and a member, but not a member
450 template. This function does not concern itself with the origin of
451 T, only its present state. So if we have
453 template <class T> class C { template <class U> void f(U); }
455 then neither C<int>::f<char> nor C<T>::f<double> is considered
456 to be a member template. But, `template <class U> void
457 C<int>::f(U)' is considered a member template. */
460 is_member_template (tree t)
462 if (!DECL_FUNCTION_TEMPLATE_P (t))
463 /* Anything that isn't a function or a template function is
464 certainly not a member template. */
467 /* A local class can't have member templates. */
468 if (decl_function_context (t))
471 return (DECL_FUNCTION_MEMBER_P (DECL_TEMPLATE_RESULT (t))
472 /* If there are more levels of template parameters than
473 there are template classes surrounding the declaration,
474 then we have a member template. */
475 && (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (t)) >
476 template_class_depth (DECL_CONTEXT (t))));
480 /* Returns nonzero iff T is a member template class. See
481 is_member_template for a description of what precisely constitutes
482 a member template. */
485 is_member_template_class (tree t)
487 if (!DECL_CLASS_TEMPLATE_P (t))
488 /* Anything that isn't a class template, is certainly not a member
492 if (!DECL_CLASS_SCOPE_P (t))
493 /* Anything whose context isn't a class type is surely not a
497 /* If there are more levels of template parameters than there are
498 template classes surrounding the declaration, then we have a
500 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (t)) >
501 template_class_depth (DECL_CONTEXT (t)));
505 /* Return a new template argument vector which contains all of ARGS,
506 but has as its innermost set of arguments the EXTRA_ARGS. */
509 add_to_template_args (tree args, tree extra_args)
516 extra_depth = TMPL_ARGS_DEPTH (extra_args);
517 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
519 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
520 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
522 for (j = 1; j <= extra_depth; ++j, ++i)
523 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
528 /* Like add_to_template_args, but only the outermost ARGS are added to
529 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
530 (EXTRA_ARGS) levels are added. This function is used to combine
531 the template arguments from a partial instantiation with the
532 template arguments used to attain the full instantiation from the
533 partial instantiation. */
536 add_outermost_template_args (tree args, tree extra_args)
540 /* If there are more levels of EXTRA_ARGS than there are ARGS,
541 something very fishy is going on. */
542 my_friendly_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args),
545 /* If *all* the new arguments will be the EXTRA_ARGS, just return
547 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
550 /* For the moment, we make ARGS look like it contains fewer levels. */
551 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
553 new_args = add_to_template_args (args, extra_args);
555 /* Now, we restore ARGS to its full dimensions. */
556 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
561 /* Return the N levels of innermost template arguments from the ARGS. */
564 get_innermost_template_args (tree args, int n)
570 my_friendly_assert (n >= 0, 20000603);
572 /* If N is 1, just return the innermost set of template arguments. */
574 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
576 /* If we're not removing anything, just return the arguments we were
578 extra_levels = TMPL_ARGS_DEPTH (args) - n;
579 my_friendly_assert (extra_levels >= 0, 20000603);
580 if (extra_levels == 0)
583 /* Make a new set of arguments, not containing the outer arguments. */
584 new_args = make_tree_vec (n);
585 for (i = 1; i <= n; ++i)
586 SET_TMPL_ARGS_LEVEL (new_args, i,
587 TMPL_ARGS_LEVEL (args, i + extra_levels));
592 /* We've got a template header coming up; push to a new level for storing
596 begin_template_parm_list (void)
598 /* We use a non-tag-transparent scope here, which causes pushtag to
599 put tags in this scope, rather than in the enclosing class or
600 namespace scope. This is the right thing, since we want
601 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
602 global template class, push_template_decl handles putting the
603 TEMPLATE_DECL into top-level scope. For a nested template class,
606 template <class T> struct S1 {
607 template <class T> struct S2 {};
610 pushtag contains special code to call pushdecl_with_scope on the
611 TEMPLATE_DECL for S2. */
612 begin_scope (sk_template_parms);
613 ++processing_template_decl;
614 ++processing_template_parmlist;
615 note_template_header (0);
618 /* This routine is called when a specialization is declared. If it is
619 invalid to declare a specialization here, an error is reported. */
622 check_specialization_scope (void)
624 tree scope = current_scope ();
628 An explicit specialization shall be declared in the namespace of
629 which the template is a member, or, for member templates, in the
630 namespace of which the enclosing class or enclosing class
631 template is a member. An explicit specialization of a member
632 function, member class or static data member of a class template
633 shall be declared in the namespace of which the class template
635 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
636 error ("explicit specialization in non-namespace scope `%D'",
641 In an explicit specialization declaration for a member of a class
642 template or a member template that appears in namespace scope,
643 the member template and some of its enclosing class templates may
644 remain unspecialized, except that the declaration shall not
645 explicitly specialize a class member template if its enclosing
646 class templates are not explicitly specialized as well. */
647 if (current_template_parms)
648 error ("enclosing class templates are not explicitly specialized");
651 /* We've just seen template <>. */
654 begin_specialization (void)
656 begin_scope (sk_template_spec);
657 note_template_header (1);
658 check_specialization_scope ();
661 /* Called at then end of processing a declaration preceded by
665 end_specialization (void)
668 reset_specialization ();
671 /* Any template <>'s that we have seen thus far are not referring to a
672 function specialization. */
675 reset_specialization (void)
677 processing_specialization = 0;
678 template_header_count = 0;
681 /* We've just seen a template header. If SPECIALIZATION is nonzero,
682 it was of the form template <>. */
685 note_template_header (int specialization)
687 processing_specialization = specialization;
688 template_header_count++;
691 /* We're beginning an explicit instantiation. */
694 begin_explicit_instantiation (void)
696 my_friendly_assert (!processing_explicit_instantiation, 20020913);
697 processing_explicit_instantiation = true;
702 end_explicit_instantiation (void)
704 my_friendly_assert(processing_explicit_instantiation, 20020913);
705 processing_explicit_instantiation = false;
708 /* The TYPE is being declared. If it is a template type, that means it
709 is a partial specialization. Do appropriate error-checking. */
712 maybe_process_partial_specialization (tree type)
714 /* TYPE maybe an ERROR_MARK_NODE. */
715 tree context = TYPE_P (type) ? TYPE_CONTEXT (type) : NULL_TREE;
717 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
719 /* This is for ordinary explicit specialization and partial
720 specialization of a template class such as:
722 template <> class C<int>;
726 template <class T> class C<T*>;
728 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
730 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
731 && !COMPLETE_TYPE_P (type))
733 if (current_namespace
734 != decl_namespace_context (CLASSTYPE_TI_TEMPLATE (type)))
736 pedwarn ("specializing `%#T' in different namespace", type);
737 cp_pedwarn_at (" from definition of `%#D'",
738 CLASSTYPE_TI_TEMPLATE (type));
740 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
741 if (processing_template_decl)
742 push_template_decl (TYPE_MAIN_DECL (type));
744 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
745 error ("specialization of `%T' after instantiation", type);
747 else if (CLASS_TYPE_P (type)
748 && !CLASSTYPE_USE_TEMPLATE (type)
749 && CLASSTYPE_TEMPLATE_INFO (type)
750 && context && CLASS_TYPE_P (context)
751 && CLASSTYPE_TEMPLATE_INFO (context))
753 /* This is for an explicit specialization of member class
754 template according to [temp.expl.spec/18]:
756 template <> template <class U> class C<int>::D;
758 The context `C<int>' must be an implicit instantiation.
759 Otherwise this is just a member class template declared
762 template <> class C<int> { template <class U> class D; };
763 template <> template <class U> class C<int>::D;
765 In the first case, `C<int>::D' is a specialization of `C<T>::D'
766 while in the second case, `C<int>::D' is a primary template
767 and `C<T>::D' may not exist. */
769 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
770 && !COMPLETE_TYPE_P (type))
774 if (current_namespace
775 != decl_namespace_context (CLASSTYPE_TI_TEMPLATE (type)))
777 pedwarn ("specializing `%#T' in different namespace", type);
778 cp_pedwarn_at (" from definition of `%#D'",
779 CLASSTYPE_TI_TEMPLATE (type));
782 /* Check for invalid specialization after instantiation:
784 template <> template <> class C<int>::D<int>;
785 template <> template <class U> class C<int>::D; */
787 for (t = DECL_TEMPLATE_INSTANTIATIONS
788 (most_general_template (CLASSTYPE_TI_TEMPLATE (type)));
789 t; t = TREE_CHAIN (t))
790 if (TREE_VALUE (t) != type
791 && TYPE_CONTEXT (TREE_VALUE (t)) == context)
792 error ("specialization `%T' after instantiation `%T'",
793 type, TREE_VALUE (t));
795 /* Mark TYPE as a specialization. And as a result, we only
796 have one level of template argument for the innermost
798 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
799 CLASSTYPE_TI_ARGS (type)
800 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
803 else if (processing_specialization)
804 error ("explicit specialization of non-template `%T'", type);
807 /* Retrieve the specialization (in the sense of [temp.spec] - a
808 specialization is either an instantiation or an explicit
809 specialization) of TMPL for the given template ARGS. If there is
810 no such specialization, return NULL_TREE. The ARGS are a vector of
811 arguments, or a vector of vectors of arguments, in the case of
812 templates with more than one level of parameters. */
815 retrieve_specialization (tree tmpl, tree args)
819 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 0);
821 /* There should be as many levels of arguments as there are
822 levels of parameters. */
823 my_friendly_assert (TMPL_ARGS_DEPTH (args)
824 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)),
827 for (s = DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
830 if (comp_template_args (TREE_PURPOSE (s), args))
831 return TREE_VALUE (s);
836 /* Like retrieve_specialization, but for local declarations. */
839 retrieve_local_specialization (tree tmpl)
841 tree spec = htab_find_with_hash (local_specializations, tmpl,
842 htab_hash_pointer (tmpl));
843 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
846 /* Returns nonzero iff DECL is a specialization of TMPL. */
849 is_specialization_of (tree decl, tree tmpl)
853 if (TREE_CODE (decl) == FUNCTION_DECL)
857 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
863 my_friendly_assert (TREE_CODE (decl) == TYPE_DECL, 0);
865 for (t = TREE_TYPE (decl);
867 t = CLASSTYPE_USE_TEMPLATE (t)
868 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
869 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
876 /* Register the specialization SPEC as a specialization of TMPL with
877 the indicated ARGS. Returns SPEC, or an equivalent prior
878 declaration, if available. */
881 register_specialization (tree spec, tree tmpl, tree args)
885 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 0);
887 if (TREE_CODE (spec) == FUNCTION_DECL
888 && uses_template_parms (DECL_TI_ARGS (spec)))
889 /* This is the FUNCTION_DECL for a partial instantiation. Don't
890 register it; we want the corresponding TEMPLATE_DECL instead.
891 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
892 the more obvious `uses_template_parms (spec)' to avoid problems
893 with default function arguments. In particular, given
896 template <class T> void f(T t1, T t = T())
898 the default argument expression is not substituted for in an
899 instantiation unless and until it is actually needed. */
902 /* There should be as many levels of arguments as there are
903 levels of parameters. */
904 my_friendly_assert (TMPL_ARGS_DEPTH (args)
905 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)),
908 for (s = DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
912 tree fn = TREE_VALUE (s);
914 /* We can sometimes try to re-register a specialization that we've
915 already got. In particular, regenerate_decl_from_template
916 calls duplicate_decls which will update the specialization
917 list. But, we'll still get called again here anyhow. It's
918 more convenient to simply allow this than to try to prevent it. */
921 else if (comp_template_args (TREE_PURPOSE (s), args))
923 if (DECL_TEMPLATE_SPECIALIZATION (spec))
925 if (DECL_TEMPLATE_INSTANTIATION (fn))
928 || DECL_EXPLICIT_INSTANTIATION (fn))
930 error ("specialization of %D after instantiation",
936 /* This situation should occur only if the first
937 specialization is an implicit instantiation,
938 the second is an explicit specialization, and
939 the implicit instantiation has not yet been
940 used. That situation can occur if we have
941 implicitly instantiated a member function and
942 then specialized it later.
944 We can also wind up here if a friend
945 declaration that looked like an instantiation
946 turns out to be a specialization:
948 template <class T> void foo(T);
949 class S { friend void foo<>(int) };
950 template <> void foo(int);
952 We transform the existing DECL in place so that
953 any pointers to it become pointers to the
956 If there was a definition for the template, but
957 not for the specialization, we want this to
958 look as if there is no definition, and vice
960 DECL_INITIAL (fn) = NULL_TREE;
961 duplicate_decls (spec, fn);
966 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
968 if (!duplicate_decls (spec, fn) && DECL_INITIAL (spec))
969 /* Dup decl failed, but this is a new
970 definition. Set the line number so any errors
971 match this new definition. */
972 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
980 DECL_TEMPLATE_SPECIALIZATIONS (tmpl)
981 = tree_cons (args, spec, DECL_TEMPLATE_SPECIALIZATIONS (tmpl));
986 /* Unregister the specialization SPEC as a specialization of TMPL.
987 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
988 if the SPEC was listed as a specialization of TMPL. */
991 reregister_specialization (tree spec, tree tmpl, tree new_spec)
995 for (s = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
997 s = &TREE_CHAIN (*s))
998 if (TREE_VALUE (*s) == spec)
1001 *s = TREE_CHAIN (*s);
1003 TREE_VALUE (*s) = new_spec;
1010 /* Compare an entry in the local specializations hash table P1 (which
1011 is really a pointer to a TREE_LIST) with P2 (which is really a
1015 eq_local_specializations (const void *p1, const void *p2)
1017 return TREE_VALUE ((tree) p1) == (tree) p2;
1020 /* Hash P1, an entry in the local specializations table. */
1023 hash_local_specialization (const void* p1)
1025 return htab_hash_pointer (TREE_VALUE ((tree) p1));
1028 /* Like register_specialization, but for local declarations. We are
1029 registering SPEC, an instantiation of TMPL. */
1032 register_local_specialization (tree spec, tree tmpl)
1036 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1037 htab_hash_pointer (tmpl), INSERT);
1038 *slot = build_tree_list (spec, tmpl);
1041 /* Print the list of candidate FNS in an error message. */
1044 print_candidates (tree fns)
1048 const char *str = "candidates are:";
1050 for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
1054 for (f = TREE_VALUE (fn); f; f = OVL_NEXT (f))
1055 cp_error_at ("%s %+#D", str, OVL_CURRENT (f));
1060 /* Returns the template (one of the functions given by TEMPLATE_ID)
1061 which can be specialized to match the indicated DECL with the
1062 explicit template args given in TEMPLATE_ID. The DECL may be
1063 NULL_TREE if none is available. In that case, the functions in
1064 TEMPLATE_ID are non-members.
1066 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1067 specialization of a member template.
1069 The template args (those explicitly specified and those deduced)
1070 are output in a newly created vector *TARGS_OUT.
1072 If it is impossible to determine the result, an error message is
1073 issued. The error_mark_node is returned to indicate failure. */
1076 determine_specialization (tree template_id,
1079 int need_member_template)
1083 tree explicit_targs;
1084 tree candidates = NULL_TREE;
1085 tree templates = NULL_TREE;
1087 *targs_out = NULL_TREE;
1089 if (template_id == error_mark_node)
1090 return error_mark_node;
1092 fns = TREE_OPERAND (template_id, 0);
1093 explicit_targs = TREE_OPERAND (template_id, 1);
1095 if (fns == error_mark_node)
1096 return error_mark_node;
1098 /* Check for baselinks. */
1099 if (BASELINK_P (fns))
1100 fns = BASELINK_FUNCTIONS (fns);
1102 if (!is_overloaded_fn (fns))
1104 error ("`%D' is not a function template", fns);
1105 return error_mark_node;
1108 for (; fns; fns = OVL_NEXT (fns))
1110 tree fn = OVL_CURRENT (fns);
1112 if (TREE_CODE (fn) == TEMPLATE_DECL)
1114 tree decl_arg_types;
1116 /* DECL might be a specialization of FN. */
1118 /* Adjust the type of DECL in case FN is a static member. */
1119 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1120 if (DECL_STATIC_FUNCTION_P (fn)
1121 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1122 decl_arg_types = TREE_CHAIN (decl_arg_types);
1124 /* Check that the number of function parameters matches.
1126 template <class T> void f(int i = 0);
1127 template <> void f<int>();
1128 The specialization f<int> is invalid but is not caught
1129 by get_bindings below. */
1131 if (list_length (TYPE_ARG_TYPES (TREE_TYPE (fn)))
1132 != list_length (decl_arg_types))
1135 /* See whether this function might be a specialization of this
1137 targs = get_bindings (fn, decl, explicit_targs);
1140 /* We cannot deduce template arguments that when used to
1141 specialize TMPL will produce DECL. */
1144 /* Save this template, and the arguments deduced. */
1145 templates = tree_cons (targs, fn, templates);
1147 else if (need_member_template)
1148 /* FN is an ordinary member function, and we need a
1149 specialization of a member template. */
1151 else if (TREE_CODE (fn) != FUNCTION_DECL)
1152 /* We can get IDENTIFIER_NODEs here in certain erroneous
1155 else if (!DECL_FUNCTION_MEMBER_P (fn))
1156 /* This is just an ordinary non-member function. Nothing can
1157 be a specialization of that. */
1159 else if (DECL_ARTIFICIAL (fn))
1160 /* Cannot specialize functions that are created implicitly. */
1164 tree decl_arg_types;
1166 /* This is an ordinary member function. However, since
1167 we're here, we can assume it's enclosing class is a
1168 template class. For example,
1170 template <typename T> struct S { void f(); };
1171 template <> void S<int>::f() {}
1173 Here, S<int>::f is a non-template, but S<int> is a
1174 template class. If FN has the same type as DECL, we
1175 might be in business. */
1177 if (!DECL_TEMPLATE_INFO (fn))
1178 /* Its enclosing class is an explicit specialization
1179 of a template class. This is not a candidate. */
1182 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1183 TREE_TYPE (TREE_TYPE (fn))))
1184 /* The return types differ. */
1187 /* Adjust the type of DECL in case FN is a static member. */
1188 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1189 if (DECL_STATIC_FUNCTION_P (fn)
1190 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1191 decl_arg_types = TREE_CHAIN (decl_arg_types);
1193 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1196 candidates = tree_cons (NULL_TREE, fn, candidates);
1200 if (templates && TREE_CHAIN (templates))
1206 It is possible for a specialization with a given function
1207 signature to be instantiated from more than one function
1208 template. In such cases, explicit specification of the
1209 template arguments must be used to uniquely identify the
1210 function template specialization being specialized.
1212 Note that here, there's no suggestion that we're supposed to
1213 determine which of the candidate templates is most
1214 specialized. However, we, also have:
1218 Partial ordering of overloaded function template
1219 declarations is used in the following contexts to select
1220 the function template to which a function template
1221 specialization refers:
1223 -- when an explicit specialization refers to a function
1226 So, we do use the partial ordering rules, at least for now.
1227 This extension can only serve to make invalid programs valid,
1228 so it's safe. And, there is strong anecdotal evidence that
1229 the committee intended the partial ordering rules to apply;
1230 the EDG front-end has that behavior, and John Spicer claims
1231 that the committee simply forgot to delete the wording in
1232 [temp.expl.spec]. */
1233 tree tmpl = most_specialized (templates, decl, explicit_targs);
1234 if (tmpl && tmpl != error_mark_node)
1236 targs = get_bindings (tmpl, decl, explicit_targs);
1237 templates = tree_cons (targs, tmpl, NULL_TREE);
1241 if (templates == NULL_TREE && candidates == NULL_TREE)
1243 cp_error_at ("template-id `%D' for `%+D' does not match any template declaration",
1245 return error_mark_node;
1247 else if ((templates && TREE_CHAIN (templates))
1248 || (candidates && TREE_CHAIN (candidates))
1249 || (templates && candidates))
1251 cp_error_at ("ambiguous template specialization `%D' for `%+D'",
1253 chainon (candidates, templates);
1254 print_candidates (candidates);
1255 return error_mark_node;
1258 /* We have one, and exactly one, match. */
1261 /* It was a specialization of an ordinary member function in a
1263 *targs_out = copy_node (DECL_TI_ARGS (TREE_VALUE (candidates)));
1264 return DECL_TI_TEMPLATE (TREE_VALUE (candidates));
1267 /* It was a specialization of a template. */
1268 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1269 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1271 *targs_out = copy_node (targs);
1272 SET_TMPL_ARGS_LEVEL (*targs_out,
1273 TMPL_ARGS_DEPTH (*targs_out),
1274 TREE_PURPOSE (templates));
1277 *targs_out = TREE_PURPOSE (templates);
1278 return TREE_VALUE (templates);
1281 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1282 but with the default argument values filled in from those in the
1286 copy_default_args_to_explicit_spec_1 (tree spec_types,
1289 tree new_spec_types;
1294 if (spec_types == void_list_node)
1295 return void_list_node;
1297 /* Substitute into the rest of the list. */
1299 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
1300 TREE_CHAIN (tmpl_types));
1302 /* Add the default argument for this parameter. */
1303 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
1304 TREE_VALUE (spec_types),
1308 /* DECL is an explicit specialization. Replicate default arguments
1309 from the template it specializes. (That way, code like:
1311 template <class T> void f(T = 3);
1312 template <> void f(double);
1315 works, as required.) An alternative approach would be to look up
1316 the correct default arguments at the call-site, but this approach
1317 is consistent with how implicit instantiations are handled. */
1320 copy_default_args_to_explicit_spec (tree decl)
1325 tree new_spec_types;
1329 tree object_type = NULL_TREE;
1330 tree in_charge = NULL_TREE;
1331 tree vtt = NULL_TREE;
1333 /* See if there's anything we need to do. */
1334 tmpl = DECL_TI_TEMPLATE (decl);
1335 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
1336 for (t = tmpl_types; t; t = TREE_CHAIN (t))
1337 if (TREE_PURPOSE (t))
1342 old_type = TREE_TYPE (decl);
1343 spec_types = TYPE_ARG_TYPES (old_type);
1345 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1347 /* Remove the this pointer, but remember the object's type for
1349 object_type = TREE_TYPE (TREE_VALUE (spec_types));
1350 spec_types = TREE_CHAIN (spec_types);
1351 tmpl_types = TREE_CHAIN (tmpl_types);
1353 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
1355 /* DECL may contain more parameters than TMPL due to the extra
1356 in-charge parameter in constructors and destructors. */
1357 in_charge = spec_types;
1358 spec_types = TREE_CHAIN (spec_types);
1360 if (DECL_HAS_VTT_PARM_P (decl))
1363 spec_types = TREE_CHAIN (spec_types);
1367 /* Compute the merged default arguments. */
1369 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
1371 /* Compute the new FUNCTION_TYPE. */
1375 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
1380 /* Put the in-charge parameter back. */
1381 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
1382 TREE_VALUE (in_charge),
1385 new_type = build_method_type_directly (object_type,
1386 TREE_TYPE (old_type),
1390 new_type = build_function_type (TREE_TYPE (old_type),
1392 new_type = build_type_attribute_variant (new_type,
1393 TYPE_ATTRIBUTES (old_type));
1394 new_type = build_exception_variant (new_type,
1395 TYPE_RAISES_EXCEPTIONS (old_type));
1396 TREE_TYPE (decl) = new_type;
1399 /* Check to see if the function just declared, as indicated in
1400 DECLARATOR, and in DECL, is a specialization of a function
1401 template. We may also discover that the declaration is an explicit
1402 instantiation at this point.
1404 Returns DECL, or an equivalent declaration that should be used
1405 instead if all goes well. Issues an error message if something is
1406 amiss. Returns error_mark_node if the error is not easily
1409 FLAGS is a bitmask consisting of the following flags:
1411 2: The function has a definition.
1412 4: The function is a friend.
1414 The TEMPLATE_COUNT is the number of references to qualifying
1415 template classes that appeared in the name of the function. For
1418 template <class T> struct S { void f(); };
1421 the TEMPLATE_COUNT would be 1. However, explicitly specialized
1422 classes are not counted in the TEMPLATE_COUNT, so that in
1424 template <class T> struct S {};
1425 template <> struct S<int> { void f(); }
1426 template <> void S<int>::f();
1428 the TEMPLATE_COUNT would be 0. (Note that this declaration is
1429 invalid; there should be no template <>.)
1431 If the function is a specialization, it is marked as such via
1432 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
1433 is set up correctly, and it is added to the list of specializations
1434 for that template. */
1437 check_explicit_specialization (tree declarator,
1442 int have_def = flags & 2;
1443 int is_friend = flags & 4;
1444 int specialization = 0;
1445 int explicit_instantiation = 0;
1446 int member_specialization = 0;
1447 tree ctype = DECL_CLASS_CONTEXT (decl);
1448 tree dname = DECL_NAME (decl);
1451 tsk = current_tmpl_spec_kind (template_count);
1456 if (processing_specialization)
1459 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1461 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1464 /* This could be something like:
1466 template <class T> void f(T);
1467 class S { friend void f<>(int); } */
1471 /* This case handles bogus declarations like template <>
1472 template <class T> void f<int>(); */
1474 error ("template-id `%D' in declaration of primary template",
1481 case tsk_invalid_member_spec:
1482 /* The error has already been reported in
1483 check_specialization_scope. */
1484 return error_mark_node;
1486 case tsk_invalid_expl_inst:
1487 error ("template parameter list used in explicit instantiation");
1493 error ("definition provided for explicit instantiation");
1495 explicit_instantiation = 1;
1498 case tsk_excessive_parms:
1499 error ("too many template parameter lists in declaration of `%D'",
1501 return error_mark_node;
1505 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1507 member_specialization = 1;
1512 case tsk_insufficient_parms:
1513 if (template_header_count)
1515 error("too few template parameter lists in declaration of `%D'",
1519 else if (ctype != NULL_TREE
1520 && !TYPE_BEING_DEFINED (ctype)
1521 && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype)
1524 /* For backwards compatibility, we accept:
1526 template <class T> struct S { void f(); };
1527 void S<int>::f() {} // Missing template <>
1529 That used to be valid C++. */
1532 ("explicit specialization not preceded by `template <>'");
1534 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1539 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1541 /* This case handles bogus declarations like template <>
1542 template <class T> void f<int>(); */
1544 if (uses_template_parms (declarator))
1545 error ("partial specialization `%D' of function template",
1548 error ("template-id `%D' in declaration of primary template",
1553 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
1554 /* This is a specialization of a member template, without
1555 specialization the containing class. Something like:
1557 template <class T> struct S {
1558 template <class U> void f (U);
1560 template <> template <class U> void S<int>::f(U) {}
1562 That's a specialization -- but of the entire template. */
1570 if (specialization || member_specialization)
1572 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
1573 for (; t; t = TREE_CHAIN (t))
1574 if (TREE_PURPOSE (t))
1577 ("default argument specified in explicit specialization");
1580 if (current_lang_name == lang_name_c)
1581 error ("template specialization with C linkage");
1584 if (specialization || member_specialization || explicit_instantiation)
1586 tree tmpl = NULL_TREE;
1587 tree targs = NULL_TREE;
1589 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
1590 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
1594 my_friendly_assert (TREE_CODE (declarator) == IDENTIFIER_NODE, 0);
1599 /* If there is no class context, the explicit instantiation
1600 must be at namespace scope. */
1601 my_friendly_assert (DECL_NAMESPACE_SCOPE_P (decl), 20030625);
1603 /* Find the namespace binding, using the declaration
1605 fns = namespace_binding (dname, CP_DECL_CONTEXT (decl));
1608 declarator = lookup_template_function (fns, NULL_TREE);
1611 if (declarator == error_mark_node)
1612 return error_mark_node;
1614 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
1616 if (!explicit_instantiation)
1617 /* A specialization in class scope. This is invalid,
1618 but the error will already have been flagged by
1619 check_specialization_scope. */
1620 return error_mark_node;
1623 /* It's not valid to write an explicit instantiation in
1626 class C { template void f(); }
1628 This case is caught by the parser. However, on
1631 template class C { void f(); };
1633 (which is invalid) we can get here. The error will be
1640 else if (ctype != NULL_TREE
1641 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
1644 /* Find the list of functions in ctype that have the same
1645 name as the declared function. */
1646 tree name = TREE_OPERAND (declarator, 0);
1647 tree fns = NULL_TREE;
1650 if (constructor_name_p (name, ctype))
1652 int is_constructor = DECL_CONSTRUCTOR_P (decl);
1654 if (is_constructor ? !TYPE_HAS_CONSTRUCTOR (ctype)
1655 : !TYPE_HAS_DESTRUCTOR (ctype))
1657 /* From [temp.expl.spec]:
1659 If such an explicit specialization for the member
1660 of a class template names an implicitly-declared
1661 special member function (clause _special_), the
1662 program is ill-formed.
1664 Similar language is found in [temp.explicit]. */
1665 error ("specialization of implicitly-declared special member function");
1666 return error_mark_node;
1669 name = is_constructor ? ctor_identifier : dtor_identifier;
1672 if (!DECL_CONV_FN_P (decl))
1674 idx = lookup_fnfields_1 (ctype, name);
1676 fns = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (ctype), idx);
1682 /* For a type-conversion operator, we cannot do a
1683 name-based lookup. We might be looking for `operator
1684 int' which will be a specialization of `operator T'.
1685 So, we find *all* the conversion operators, and then
1686 select from them. */
1689 methods = CLASSTYPE_METHOD_VEC (ctype);
1691 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
1692 idx < TREE_VEC_LENGTH (methods); ++idx)
1694 tree ovl = TREE_VEC_ELT (methods, idx);
1696 if (!ovl || !DECL_CONV_FN_P (OVL_CURRENT (ovl)))
1697 /* There are no more conversion functions. */
1700 /* Glue all these conversion functions together
1701 with those we already have. */
1702 for (; ovl; ovl = OVL_NEXT (ovl))
1703 fns = ovl_cons (OVL_CURRENT (ovl), fns);
1707 if (fns == NULL_TREE)
1709 error ("no member function `%D' declared in `%T'",
1711 return error_mark_node;
1714 TREE_OPERAND (declarator, 0) = fns;
1717 /* Figure out what exactly is being specialized at this point.
1718 Note that for an explicit instantiation, even one for a
1719 member function, we cannot tell apriori whether the
1720 instantiation is for a member template, or just a member
1721 function of a template class. Even if a member template is
1722 being instantiated, the member template arguments may be
1723 elided if they can be deduced from the rest of the
1725 tmpl = determine_specialization (declarator, decl,
1727 member_specialization);
1729 if (!tmpl || tmpl == error_mark_node)
1730 /* We couldn't figure out what this declaration was
1732 return error_mark_node;
1735 tree gen_tmpl = most_general_template (tmpl);
1737 if (explicit_instantiation)
1739 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
1740 is done by do_decl_instantiation later. */
1742 int arg_depth = TMPL_ARGS_DEPTH (targs);
1743 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
1745 if (arg_depth > parm_depth)
1747 /* If TMPL is not the most general template (for
1748 example, if TMPL is a friend template that is
1749 injected into namespace scope), then there will
1750 be too many levels of TARGS. Remove some of them
1755 new_targs = make_tree_vec (parm_depth);
1756 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
1757 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
1758 = TREE_VEC_ELT (targs, i);
1762 return instantiate_template (tmpl, targs, tf_error);
1765 /* If we thought that the DECL was a member function, but it
1766 turns out to be specializing a static member function,
1767 make DECL a static member function as well. We also have
1768 to adjust last_function_parms to avoid confusing
1769 start_function later. */
1770 if (DECL_STATIC_FUNCTION_P (tmpl)
1771 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1773 revert_static_member_fn (decl);
1774 last_function_parms = TREE_CHAIN (last_function_parms);
1777 /* If this is a specialization of a member template of a
1778 template class. In we want to return the TEMPLATE_DECL,
1779 not the specialization of it. */
1780 if (tsk == tsk_template)
1782 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
1783 DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl)) = NULL_TREE;
1786 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
1787 DECL_SOURCE_LOCATION (DECL_TEMPLATE_RESULT (tmpl))
1788 = DECL_SOURCE_LOCATION (decl);
1793 /* Set up the DECL_TEMPLATE_INFO for DECL. */
1794 DECL_TEMPLATE_INFO (decl) = tree_cons (tmpl, targs, NULL_TREE);
1796 /* Inherit default function arguments from the template
1797 DECL is specializing. */
1798 copy_default_args_to_explicit_spec (decl);
1800 /* This specialization has the same protection as the
1801 template it specializes. */
1802 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
1803 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
1805 if (is_friend && !have_def)
1806 /* This is not really a declaration of a specialization.
1807 It's just the name of an instantiation. But, it's not
1808 a request for an instantiation, either. */
1809 SET_DECL_IMPLICIT_INSTANTIATION (decl);
1810 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
1811 /* This is indeed a specialization. In case of constructors
1812 and destructors, we need in-charge and not-in-charge
1813 versions in V3 ABI. */
1814 clone_function_decl (decl, /*update_method_vec_p=*/0);
1816 /* Register this specialization so that we can find it
1818 decl = register_specialization (decl, gen_tmpl, targs);
1825 /* TYPE is being declared. Verify that the use of template headers
1826 and such is reasonable. Issue error messages if not. */
1829 maybe_check_template_type (tree type)
1831 if (template_header_count)
1833 /* We are in the scope of some `template <...>' header. */
1836 = template_class_depth_real (TYPE_CONTEXT (type),
1837 /*count_specializations=*/1);
1839 if (template_header_count <= context_depth)
1840 /* This is OK; the template headers are for the context. We
1841 are actually too lenient here; like
1842 check_explicit_specialization we should consider the number
1843 of template types included in the actual declaration. For
1846 template <class T> struct S {
1847 template <class U> template <class V>
1853 template <class T> struct S {
1854 template <class U> struct I;
1857 template <class T> template <class U.
1862 else if (template_header_count > context_depth + 1)
1863 /* There are two many template parameter lists. */
1864 error ("too many template parameter lists in declaration of `%T'", type);
1868 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
1869 parameters. These are represented in the same format used for
1870 DECL_TEMPLATE_PARMS. */
1872 int comp_template_parms (tree parms1, tree parms2)
1877 if (parms1 == parms2)
1880 for (p1 = parms1, p2 = parms2;
1881 p1 != NULL_TREE && p2 != NULL_TREE;
1882 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
1884 tree t1 = TREE_VALUE (p1);
1885 tree t2 = TREE_VALUE (p2);
1888 my_friendly_assert (TREE_CODE (t1) == TREE_VEC, 0);
1889 my_friendly_assert (TREE_CODE (t2) == TREE_VEC, 0);
1891 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
1894 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
1896 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
1897 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
1899 if (TREE_CODE (parm1) != TREE_CODE (parm2))
1902 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM)
1904 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
1909 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
1910 /* One set of parameters has more parameters lists than the
1917 /* Complain if DECL shadows a template parameter.
1919 [temp.local]: A template-parameter shall not be redeclared within its
1920 scope (including nested scopes). */
1923 check_template_shadow (tree decl)
1927 /* If we're not in a template, we can't possibly shadow a template
1929 if (!current_template_parms)
1932 /* Figure out what we're shadowing. */
1933 if (TREE_CODE (decl) == OVERLOAD)
1934 decl = OVL_CURRENT (decl);
1935 olddecl = IDENTIFIER_VALUE (DECL_NAME (decl));
1937 /* If there's no previous binding for this name, we're not shadowing
1938 anything, let alone a template parameter. */
1942 /* If we're not shadowing a template parameter, we're done. Note
1943 that OLDDECL might be an OVERLOAD (or perhaps even an
1944 ERROR_MARK), so we can't just blithely assume it to be a _DECL
1946 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
1949 /* We check for decl != olddecl to avoid bogus errors for using a
1950 name inside a class. We check TPFI to avoid duplicate errors for
1951 inline member templates. */
1953 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
1956 cp_error_at ("declaration of `%#D'", decl);
1957 cp_error_at (" shadows template parm `%#D'", olddecl);
1960 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
1961 ORIG_LEVEL, DECL, and TYPE. */
1964 build_template_parm_index (int index,
1970 tree t = make_node (TEMPLATE_PARM_INDEX);
1971 TEMPLATE_PARM_IDX (t) = index;
1972 TEMPLATE_PARM_LEVEL (t) = level;
1973 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
1974 TEMPLATE_PARM_DECL (t) = decl;
1975 TREE_TYPE (t) = type;
1976 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
1977 TREE_READONLY (t) = TREE_READONLY (decl);
1982 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
1983 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
1984 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
1985 new one is created. */
1988 reduce_template_parm_level (tree index, tree type, int levels)
1990 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
1991 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
1992 != TEMPLATE_PARM_LEVEL (index) - levels))
1994 tree orig_decl = TEMPLATE_PARM_DECL (index);
1997 decl = build_decl (TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
1998 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
1999 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
2000 DECL_ARTIFICIAL (decl) = 1;
2001 SET_DECL_TEMPLATE_PARM_P (decl);
2003 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
2004 TEMPLATE_PARM_LEVEL (index) - levels,
2005 TEMPLATE_PARM_ORIG_LEVEL (index),
2007 TEMPLATE_PARM_DESCENDANTS (index) = t;
2009 /* Template template parameters need this. */
2010 DECL_TEMPLATE_PARMS (decl)
2011 = DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index));
2014 return TEMPLATE_PARM_DESCENDANTS (index);
2017 /* Process information from new template parameter NEXT and append it to the
2018 LIST being built. */
2021 process_template_parm (tree list, tree next)
2029 my_friendly_assert (TREE_CODE (parm) == TREE_LIST, 259);
2030 defval = TREE_PURPOSE (parm);
2031 parm = TREE_VALUE (parm);
2032 is_type = TREE_PURPOSE (parm) == class_type_node;
2036 tree p = TREE_VALUE (tree_last (list));
2038 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
2039 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
2041 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
2049 my_friendly_assert (TREE_CODE (TREE_PURPOSE (parm)) == TREE_LIST, 260);
2050 /* is a const-param */
2051 parm = grokdeclarator (TREE_VALUE (parm), TREE_PURPOSE (parm),
2053 SET_DECL_TEMPLATE_PARM_P (parm);
2057 The top-level cv-qualifiers on the template-parameter are
2058 ignored when determining its type. */
2059 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
2061 /* A template parameter is not modifiable. */
2062 TREE_READONLY (parm) = TREE_CONSTANT (parm) = 1;
2063 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
2064 TREE_TYPE (parm) = void_type_node;
2065 decl = build_decl (CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
2066 TREE_CONSTANT (decl) = TREE_READONLY (decl) = 1;
2067 DECL_INITIAL (parm) = DECL_INITIAL (decl)
2068 = build_template_parm_index (idx, processing_template_decl,
2069 processing_template_decl,
2070 decl, TREE_TYPE (parm));
2075 parm = TREE_VALUE (parm);
2077 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
2079 t = make_aggr_type (TEMPLATE_TEMPLATE_PARM);
2080 /* This is for distinguishing between real templates and template
2081 template parameters */
2082 TREE_TYPE (parm) = t;
2083 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
2088 t = make_aggr_type (TEMPLATE_TYPE_PARM);
2089 /* parm is either IDENTIFIER_NODE or NULL_TREE */
2090 decl = build_decl (TYPE_DECL, parm, t);
2093 TYPE_NAME (t) = decl;
2094 TYPE_STUB_DECL (t) = decl;
2096 TEMPLATE_TYPE_PARM_INDEX (t)
2097 = build_template_parm_index (idx, processing_template_decl,
2098 processing_template_decl,
2099 decl, TREE_TYPE (parm));
2101 DECL_ARTIFICIAL (decl) = 1;
2102 SET_DECL_TEMPLATE_PARM_P (decl);
2104 parm = build_tree_list (defval, parm);
2105 return chainon (list, parm);
2108 /* The end of a template parameter list has been reached. Process the
2109 tree list into a parameter vector, converting each parameter into a more
2110 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
2114 end_template_parm_list (tree parms)
2118 tree saved_parmlist = make_tree_vec (list_length (parms));
2120 current_template_parms
2121 = tree_cons (size_int (processing_template_decl),
2122 saved_parmlist, current_template_parms);
2124 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
2126 next = TREE_CHAIN (parm);
2127 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
2128 TREE_CHAIN (parm) = NULL_TREE;
2131 --processing_template_parmlist;
2133 return saved_parmlist;
2136 /* end_template_decl is called after a template declaration is seen. */
2139 end_template_decl (void)
2141 reset_specialization ();
2143 if (! processing_template_decl)
2146 /* This matches the pushlevel in begin_template_parm_list. */
2149 --processing_template_decl;
2150 current_template_parms = TREE_CHAIN (current_template_parms);
2153 /* Given a template argument vector containing the template PARMS.
2154 The innermost PARMS are given first. */
2157 current_template_args (void)
2160 tree args = NULL_TREE;
2161 int length = TMPL_PARMS_DEPTH (current_template_parms);
2164 /* If there is only one level of template parameters, we do not
2165 create a TREE_VEC of TREE_VECs. Instead, we return a single
2166 TREE_VEC containing the arguments. */
2168 args = make_tree_vec (length);
2170 for (header = current_template_parms; header; header = TREE_CHAIN (header))
2172 tree a = copy_node (TREE_VALUE (header));
2175 TREE_TYPE (a) = NULL_TREE;
2176 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
2178 tree t = TREE_VEC_ELT (a, i);
2180 /* T will be a list if we are called from within a
2181 begin/end_template_parm_list pair, but a vector directly
2182 if within a begin/end_member_template_processing pair. */
2183 if (TREE_CODE (t) == TREE_LIST)
2187 if (TREE_CODE (t) == TYPE_DECL
2188 || TREE_CODE (t) == TEMPLATE_DECL)
2191 t = DECL_INITIAL (t);
2192 TREE_VEC_ELT (a, i) = t;
2197 TREE_VEC_ELT (args, --l) = a;
2205 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
2206 template PARMS. Used by push_template_decl below. */
2209 build_template_decl (tree decl, tree parms)
2211 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
2212 DECL_TEMPLATE_PARMS (tmpl) = parms;
2213 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
2214 if (DECL_LANG_SPECIFIC (decl))
2216 DECL_STATIC_FUNCTION_P (tmpl) = DECL_STATIC_FUNCTION_P (decl);
2217 DECL_CONSTRUCTOR_P (tmpl) = DECL_CONSTRUCTOR_P (decl);
2218 DECL_DESTRUCTOR_P (tmpl) = DECL_DESTRUCTOR_P (decl);
2219 DECL_NONCONVERTING_P (tmpl) = DECL_NONCONVERTING_P (decl);
2220 DECL_ASSIGNMENT_OPERATOR_P (tmpl) = DECL_ASSIGNMENT_OPERATOR_P (decl);
2221 if (DECL_OVERLOADED_OPERATOR_P (decl))
2222 SET_OVERLOADED_OPERATOR_CODE (tmpl,
2223 DECL_OVERLOADED_OPERATOR_P (decl));
2229 struct template_parm_data
2231 /* The level of the template parameters we are currently
2235 /* The index of the specialization argument we are currently
2239 /* An array whose size is the number of template parameters. The
2240 elements are nonzero if the parameter has been used in any one
2241 of the arguments processed so far. */
2244 /* An array whose size is the number of template arguments. The
2245 elements are nonzero if the argument makes use of template
2246 parameters of this level. */
2247 int* arg_uses_template_parms;
2250 /* Subroutine of push_template_decl used to see if each template
2251 parameter in a partial specialization is used in the explicit
2252 argument list. If T is of the LEVEL given in DATA (which is
2253 treated as a template_parm_data*), then DATA->PARMS is marked
2257 mark_template_parm (tree t, void* data)
2261 struct template_parm_data* tpd = (struct template_parm_data*) data;
2263 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
2265 level = TEMPLATE_PARM_LEVEL (t);
2266 idx = TEMPLATE_PARM_IDX (t);
2270 level = TEMPLATE_TYPE_LEVEL (t);
2271 idx = TEMPLATE_TYPE_IDX (t);
2274 if (level == tpd->level)
2276 tpd->parms[idx] = 1;
2277 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
2280 /* Return zero so that for_each_template_parm will continue the
2281 traversal of the tree; we want to mark *every* template parm. */
2285 /* Process the partial specialization DECL. */
2288 process_partial_specialization (tree decl)
2290 tree type = TREE_TYPE (decl);
2291 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
2292 tree specargs = CLASSTYPE_TI_ARGS (type);
2293 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
2294 tree inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
2295 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
2296 int nargs = TREE_VEC_LENGTH (inner_args);
2297 int ntparms = TREE_VEC_LENGTH (inner_parms);
2299 int did_error_intro = 0;
2300 struct template_parm_data tpd;
2301 struct template_parm_data tpd2;
2303 /* We check that each of the template parameters given in the
2304 partial specialization is used in the argument list to the
2305 specialization. For example:
2307 template <class T> struct S;
2308 template <class T> struct S<T*>;
2310 The second declaration is OK because `T*' uses the template
2311 parameter T, whereas
2313 template <class T> struct S<int>;
2315 is no good. Even trickier is:
2326 The S2<T> declaration is actually invalid; it is a
2327 full-specialization. Of course,
2330 struct S2<T (*)(U)>;
2332 or some such would have been OK. */
2333 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
2334 tpd.parms = alloca (sizeof (int) * ntparms);
2335 memset (tpd.parms, 0, sizeof (int) * ntparms);
2337 tpd.arg_uses_template_parms = alloca (sizeof (int) * nargs);
2338 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
2339 for (i = 0; i < nargs; ++i)
2341 tpd.current_arg = i;
2342 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
2343 &mark_template_parm,
2347 for (i = 0; i < ntparms; ++i)
2348 if (tpd.parms[i] == 0)
2350 /* One of the template parms was not used in the
2352 if (!did_error_intro)
2354 error ("template parameters not used in partial specialization:");
2355 did_error_intro = 1;
2359 TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
2362 /* [temp.class.spec]
2364 The argument list of the specialization shall not be identical to
2365 the implicit argument list of the primary template. */
2366 if (comp_template_args
2368 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
2370 error ("partial specialization `%T' does not specialize any template arguments", type);
2372 /* [temp.class.spec]
2374 A partially specialized non-type argument expression shall not
2375 involve template parameters of the partial specialization except
2376 when the argument expression is a simple identifier.
2378 The type of a template parameter corresponding to a specialized
2379 non-type argument shall not be dependent on a parameter of the
2381 my_friendly_assert (nargs == DECL_NTPARMS (maintmpl), 0);
2383 for (i = 0; i < nargs; ++i)
2385 tree arg = TREE_VEC_ELT (inner_args, i);
2386 if (/* These first two lines are the `non-type' bit. */
2388 && TREE_CODE (arg) != TEMPLATE_DECL
2389 /* This next line is the `argument expression is not just a
2390 simple identifier' condition and also the `specialized
2391 non-type argument' bit. */
2392 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
2394 if (tpd.arg_uses_template_parms[i])
2395 error ("template argument `%E' involves template parameter(s)", arg);
2398 /* Look at the corresponding template parameter,
2399 marking which template parameters its type depends
2402 TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (main_inner_parms,
2407 /* We haven't yet initialized TPD2. Do so now. */
2408 tpd2.arg_uses_template_parms
2409 = alloca (sizeof (int) * nargs);
2410 /* The number of parameters here is the number in the
2411 main template, which, as checked in the assertion
2413 tpd2.parms = alloca (sizeof (int) * nargs);
2415 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
2418 /* Mark the template parameters. But this time, we're
2419 looking for the template parameters of the main
2420 template, not in the specialization. */
2421 tpd2.current_arg = i;
2422 tpd2.arg_uses_template_parms[i] = 0;
2423 memset (tpd2.parms, 0, sizeof (int) * nargs);
2424 for_each_template_parm (type,
2425 &mark_template_parm,
2429 if (tpd2.arg_uses_template_parms [i])
2431 /* The type depended on some template parameters.
2432 If they are fully specialized in the
2433 specialization, that's OK. */
2435 for (j = 0; j < nargs; ++j)
2436 if (tpd2.parms[j] != 0
2437 && tpd.arg_uses_template_parms [j])
2439 error ("type `%T' of template argument `%E' depends on template parameter(s)",
2449 if (retrieve_specialization (maintmpl, specargs))
2450 /* We've already got this specialization. */
2453 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
2454 = tree_cons (inner_args, inner_parms,
2455 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
2456 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
2460 /* Check that a template declaration's use of default arguments is not
2461 invalid. Here, PARMS are the template parameters. IS_PRIMARY is
2462 nonzero if DECL is the thing declared by a primary template.
2463 IS_PARTIAL is nonzero if DECL is a partial specialization. */
2466 check_default_tmpl_args (tree decl, tree parms, int is_primary, int is_partial)
2469 int last_level_to_check;
2474 A default template-argument shall not be specified in a
2475 function template declaration or a function template definition, nor
2476 in the template-parameter-list of the definition of a member of a
2479 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
2480 /* You can't have a function template declaration in a local
2481 scope, nor you can you define a member of a class template in a
2485 if (current_class_type
2486 && !TYPE_BEING_DEFINED (current_class_type)
2487 && DECL_LANG_SPECIFIC (decl)
2488 /* If this is either a friend defined in the scope of the class
2489 or a member function. */
2490 && (DECL_FUNCTION_MEMBER_P (decl)
2491 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
2492 : DECL_FRIEND_CONTEXT (decl)
2493 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
2495 /* And, if it was a member function, it really was defined in
2496 the scope of the class. */
2497 && (!DECL_FUNCTION_MEMBER_P (decl)
2498 || DECL_INITIALIZED_IN_CLASS_P (decl)))
2499 /* We already checked these parameters when the template was
2500 declared, so there's no need to do it again now. This function
2501 was defined in class scope, but we're processing it's body now
2502 that the class is complete. */
2507 If a template-parameter has a default template-argument, all
2508 subsequent template-parameters shall have a default
2509 template-argument supplied. */
2510 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
2512 tree inner_parms = TREE_VALUE (parm_level);
2513 int ntparms = TREE_VEC_LENGTH (inner_parms);
2514 int seen_def_arg_p = 0;
2517 for (i = 0; i < ntparms; ++i)
2519 tree parm = TREE_VEC_ELT (inner_parms, i);
2520 if (TREE_PURPOSE (parm))
2522 else if (seen_def_arg_p)
2524 error ("no default argument for `%D'", TREE_VALUE (parm));
2525 /* For better subsequent error-recovery, we indicate that
2526 there should have been a default argument. */
2527 TREE_PURPOSE (parm) = error_mark_node;
2532 if (TREE_CODE (decl) != TYPE_DECL || is_partial || !is_primary)
2533 /* For an ordinary class template, default template arguments are
2534 allowed at the innermost level, e.g.:
2535 template <class T = int>
2537 but, in a partial specialization, they're not allowed even
2538 there, as we have in [temp.class.spec]:
2540 The template parameter list of a specialization shall not
2541 contain default template argument values.
2543 So, for a partial specialization, or for a function template,
2544 we look at all of them. */
2547 /* But, for a primary class template that is not a partial
2548 specialization we look at all template parameters except the
2550 parms = TREE_CHAIN (parms);
2552 /* Figure out what error message to issue. */
2553 if (TREE_CODE (decl) == FUNCTION_DECL)
2554 msg = "default template arguments may not be used in function templates";
2555 else if (is_partial)
2556 msg = "default template arguments may not be used in partial specializations";
2558 msg = "default argument for template parameter for class enclosing `%D'";
2560 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
2561 /* If we're inside a class definition, there's no need to
2562 examine the parameters to the class itself. On the one
2563 hand, they will be checked when the class is defined, and,
2564 on the other, default arguments are valid in things like:
2565 template <class T = double>
2566 struct S { template <class U> void f(U); };
2567 Here the default argument for `S' has no bearing on the
2568 declaration of `f'. */
2569 last_level_to_check = template_class_depth (current_class_type) + 1;
2571 /* Check everything. */
2572 last_level_to_check = 0;
2574 for (parm_level = parms;
2575 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
2576 parm_level = TREE_CHAIN (parm_level))
2578 tree inner_parms = TREE_VALUE (parm_level);
2582 ntparms = TREE_VEC_LENGTH (inner_parms);
2583 for (i = 0; i < ntparms; ++i)
2584 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
2592 /* Clear out the default argument so that we are not
2594 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
2597 /* At this point, if we're still interested in issuing messages,
2598 they must apply to classes surrounding the object declared. */
2600 msg = "default argument for template parameter for class enclosing `%D'";
2604 /* Worker for push_template_decl_real, called via
2605 for_each_template_parm. DATA is really an int, indicating the
2606 level of the parameters we are interested in. If T is a template
2607 parameter of that level, return nonzero. */
2610 template_parm_this_level_p (tree t, void* data)
2612 int this_level = *(int *)data;
2615 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
2616 level = TEMPLATE_PARM_LEVEL (t);
2618 level = TEMPLATE_TYPE_LEVEL (t);
2619 return level == this_level;
2622 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
2623 parameters given by current_template_args, or reuses a
2624 previously existing one, if appropriate. Returns the DECL, or an
2625 equivalent one, if it is replaced via a call to duplicate_decls.
2627 If IS_FRIEND is nonzero, DECL is a friend declaration. */
2630 push_template_decl_real (tree decl, int is_friend)
2638 int new_template_p = 0;
2640 /* See if this is a partial specialization. */
2641 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
2642 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
2643 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
2645 is_friend |= (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl));
2648 /* For a friend, we want the context of the friend function, not
2649 the type of which it is a friend. */
2650 ctx = DECL_CONTEXT (decl);
2651 else if (CP_DECL_CONTEXT (decl)
2652 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
2653 /* In the case of a virtual function, we want the class in which
2655 ctx = CP_DECL_CONTEXT (decl);
2657 /* Otherwise, if we're currently defining some class, the DECL
2658 is assumed to be a member of the class. */
2659 ctx = current_scope ();
2661 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
2664 if (!DECL_CONTEXT (decl))
2665 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
2667 /* See if this is a primary template. */
2668 primary = template_parm_scope_p ();
2672 if (current_lang_name == lang_name_c)
2673 error ("template with C linkage");
2674 else if (TREE_CODE (decl) == TYPE_DECL
2675 && ANON_AGGRNAME_P (DECL_NAME (decl)))
2676 error ("template class without a name");
2677 else if (TREE_CODE (decl) == FUNCTION_DECL
2678 && DECL_DESTRUCTOR_P (decl))
2682 A destructor shall not be a member template. */
2683 error ("destructor `%D' declared as member template", decl);
2684 return error_mark_node;
2686 else if ((DECL_IMPLICIT_TYPEDEF_P (decl)
2687 && CLASS_TYPE_P (TREE_TYPE (decl)))
2688 || (TREE_CODE (decl) == VAR_DECL && ctx && CLASS_TYPE_P (ctx))
2689 || TREE_CODE (decl) == FUNCTION_DECL)
2692 error ("template declaration of `%#D'", decl);
2695 /* Check to see that the rules regarding the use of default
2696 arguments are not being violated. */
2697 check_default_tmpl_args (decl, current_template_parms,
2698 primary, is_partial);
2701 return process_partial_specialization (decl);
2703 args = current_template_args ();
2706 || TREE_CODE (ctx) == FUNCTION_DECL
2707 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
2708 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
2710 if (DECL_LANG_SPECIFIC (decl)
2711 && DECL_TEMPLATE_INFO (decl)
2712 && DECL_TI_TEMPLATE (decl))
2713 tmpl = DECL_TI_TEMPLATE (decl);
2714 /* If DECL is a TYPE_DECL for a class-template, then there won't
2715 be DECL_LANG_SPECIFIC. The information equivalent to
2716 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
2717 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
2718 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
2719 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
2721 /* Since a template declaration already existed for this
2722 class-type, we must be redeclaring it here. Make sure
2723 that the redeclaration is valid. */
2724 redeclare_class_template (TREE_TYPE (decl),
2725 current_template_parms);
2726 /* We don't need to create a new TEMPLATE_DECL; just use the
2727 one we already had. */
2728 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
2732 tmpl = build_template_decl (decl, current_template_parms);
2735 if (DECL_LANG_SPECIFIC (decl)
2736 && DECL_TEMPLATE_SPECIALIZATION (decl))
2738 /* A specialization of a member template of a template
2740 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2741 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
2742 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
2748 tree a, t, current, parms;
2751 if (TREE_CODE (decl) == TYPE_DECL)
2753 if ((IS_AGGR_TYPE_CODE (TREE_CODE (TREE_TYPE (decl)))
2754 || TREE_CODE (TREE_TYPE (decl)) == ENUMERAL_TYPE)
2755 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
2756 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
2757 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
2760 error ("`%D' does not declare a template type", decl);
2764 else if (!DECL_LANG_SPECIFIC (decl) || !DECL_TEMPLATE_INFO (decl))
2766 error ("template definition of non-template `%#D'", decl);
2770 tmpl = DECL_TI_TEMPLATE (decl);
2772 if (is_member_template (tmpl)
2773 && DECL_FUNCTION_TEMPLATE_P (tmpl)
2774 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
2775 && DECL_TEMPLATE_SPECIALIZATION (decl))
2779 /* The declaration is a specialization of a member
2780 template, declared outside the class. Therefore, the
2781 innermost template arguments will be NULL, so we
2782 replace them with the arguments determined by the
2783 earlier call to check_explicit_specialization. */
2784 args = DECL_TI_ARGS (decl);
2787 = build_template_decl (decl, current_template_parms);
2788 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
2789 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
2790 DECL_TI_TEMPLATE (decl) = new_tmpl;
2791 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
2792 DECL_TEMPLATE_INFO (new_tmpl)
2793 = tree_cons (tmpl, args, NULL_TREE);
2795 register_specialization (new_tmpl,
2796 most_general_template (tmpl),
2801 /* Make sure the template headers we got make sense. */
2803 parms = DECL_TEMPLATE_PARMS (tmpl);
2804 i = TMPL_PARMS_DEPTH (parms);
2805 if (TMPL_ARGS_DEPTH (args) != i)
2807 error ("expected %d levels of template parms for `%#D', got %d",
2808 i, decl, TMPL_ARGS_DEPTH (args));
2811 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
2813 a = TMPL_ARGS_LEVEL (args, i);
2814 t = INNERMOST_TEMPLATE_PARMS (parms);
2816 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
2818 if (current == decl)
2819 error ("got %d template parameters for `%#D'",
2820 TREE_VEC_LENGTH (a), decl);
2822 error ("got %d template parameters for `%#T'",
2823 TREE_VEC_LENGTH (a), current);
2824 error (" but %d required", TREE_VEC_LENGTH (t));
2827 /* Perhaps we should also check that the parms are used in the
2828 appropriate qualifying scopes in the declarator? */
2830 if (current == decl)
2833 current = TYPE_CONTEXT (current);
2837 DECL_TEMPLATE_RESULT (tmpl) = decl;
2838 TREE_TYPE (tmpl) = TREE_TYPE (decl);
2840 /* Push template declarations for global functions and types. Note
2841 that we do not try to push a global template friend declared in a
2842 template class; such a thing may well depend on the template
2843 parameters of the class. */
2844 if (new_template_p && !ctx
2845 && !(is_friend && template_class_depth (current_class_type) > 0))
2846 tmpl = pushdecl_namespace_level (tmpl);
2850 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
2851 if (DECL_CONV_FN_P (tmpl))
2853 int depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2855 /* It is a conversion operator. See if the type converted to
2856 depends on innermost template operands. */
2858 if (for_each_template_parm (TREE_TYPE (TREE_TYPE (tmpl)),
2859 template_parm_this_level_p,
2862 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
2866 info = tree_cons (tmpl, args, NULL_TREE);
2868 if (DECL_IMPLICIT_TYPEDEF_P (decl))
2870 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
2871 if ((!ctx || TREE_CODE (ctx) != FUNCTION_DECL)
2872 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
2873 /* Don't change the name if we've already set it up. */
2874 && !IDENTIFIER_TEMPLATE (DECL_NAME (decl)))
2875 DECL_NAME (decl) = classtype_mangled_name (TREE_TYPE (decl));
2877 else if (DECL_LANG_SPECIFIC (decl))
2878 DECL_TEMPLATE_INFO (decl) = info;
2880 return DECL_TEMPLATE_RESULT (tmpl);
2884 push_template_decl (tree decl)
2886 return push_template_decl_real (decl, 0);
2889 /* Called when a class template TYPE is redeclared with the indicated
2890 template PARMS, e.g.:
2892 template <class T> struct S;
2893 template <class T> struct S {}; */
2896 redeclare_class_template (tree type, tree parms)
2902 if (!TYPE_TEMPLATE_INFO (type))
2904 error ("`%T' is not a template type", type);
2908 tmpl = TYPE_TI_TEMPLATE (type);
2909 if (!PRIMARY_TEMPLATE_P (tmpl))
2910 /* The type is nested in some template class. Nothing to worry
2911 about here; there are no new template parameters for the nested
2915 parms = INNERMOST_TEMPLATE_PARMS (parms);
2916 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
2918 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
2920 cp_error_at ("previous declaration `%D'", tmpl);
2921 error ("used %d template parameter%s instead of %d",
2922 TREE_VEC_LENGTH (tmpl_parms),
2923 TREE_VEC_LENGTH (tmpl_parms) == 1 ? "" : "s",
2924 TREE_VEC_LENGTH (parms));
2928 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
2930 tree tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
2931 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
2932 tree tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
2933 tree parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
2935 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm))
2937 cp_error_at ("template parameter `%#D'", tmpl_parm);
2938 error ("redeclared here as `%#D'", parm);
2942 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
2944 /* We have in [temp.param]:
2946 A template-parameter may not be given default arguments
2947 by two different declarations in the same scope. */
2948 error ("redefinition of default argument for `%#D'", parm);
2949 error ("%H original definition appeared here",
2950 &DECL_SOURCE_LOCATION (tmpl_parm));
2954 if (parm_default != NULL_TREE)
2955 /* Update the previous template parameters (which are the ones
2956 that will really count) with the new default value. */
2957 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
2958 else if (tmpl_default != NULL_TREE)
2959 /* Update the new parameters, too; they'll be used as the
2960 parameters for any members. */
2961 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
2965 /* Attempt to convert the non-type template parameter EXPR to the
2966 indicated TYPE. If the conversion is successful, return the
2967 converted value. If the conversion is unsuccessful, return
2968 NULL_TREE if we issued an error message, or error_mark_node if we
2969 did not. We issue error messages for out-and-out bad template
2970 parameters, but not simply because the conversion failed, since we
2971 might be just trying to do argument deduction. By the time this
2972 function is called, neither TYPE nor EXPR may make use of template
2976 convert_nontype_argument (tree type, tree expr)
2978 tree expr_type = TREE_TYPE (expr);
2980 /* A template-argument for a non-type, non-template
2981 template-parameter shall be one of:
2983 --an integral constant-expression of integral or enumeration
2986 --the name of a non-type template-parameter; or
2988 --the name of an object or function with external linkage,
2989 including function templates and function template-ids but
2990 excluding non-static class members, expressed as id-expression;
2993 --the address of an object or function with external linkage,
2994 including function templates and function template-ids but
2995 excluding non-static class members, expressed as & id-expression
2996 where the & is optional if the name refers to a function or
2999 --a pointer to member expressed as described in _expr.unary.op_. */
3001 /* An integral constant-expression can include const variables or
3002 enumerators. Simplify things by folding them to their values,
3003 unless we're about to bind the declaration to a reference
3005 if (INTEGRAL_TYPE_P (expr_type)
3006 && TREE_CODE (type) != REFERENCE_TYPE)
3007 expr = decl_constant_value (expr);
3009 if (is_overloaded_fn (expr))
3010 /* OK for now. We'll check that it has external linkage later.
3011 Check this first since if expr_type is the unknown_type_node
3012 we would otherwise complain below. */
3014 else if (TYPE_PTR_TO_MEMBER_P (expr_type))
3016 if (TREE_CODE (expr) != PTRMEM_CST)
3019 else if (TYPE_PTR_P (expr_type)
3020 || TREE_CODE (expr_type) == ARRAY_TYPE
3021 || TREE_CODE (type) == REFERENCE_TYPE
3022 /* If expr is the address of an overloaded function, we
3023 will get the unknown_type_node at this point. */
3024 || expr_type == unknown_type_node)
3030 if (TREE_CODE (expr_type) == ARRAY_TYPE
3031 || (TREE_CODE (type) == REFERENCE_TYPE
3032 && TREE_CODE (e) != ADDR_EXPR))
3036 if (TREE_CODE (e) != ADDR_EXPR)
3039 error ("`%E' is not a valid template argument", expr);
3040 if (TYPE_PTR_P (expr_type))
3042 if (TREE_CODE (TREE_TYPE (expr_type)) == FUNCTION_TYPE)
3043 error ("it must be the address of a function with external linkage");
3045 error ("it must be the address of an object with external linkage");
3047 else if (TYPE_PTR_TO_MEMBER_P (expr_type))
3048 error ("it must be a pointer-to-member of the form `&X::Y'");
3053 referent = TREE_OPERAND (e, 0);
3054 STRIP_NOPS (referent);
3057 if (TREE_CODE (referent) == STRING_CST)
3059 error ("string literal %E is not a valid template argument because it is the address of an object with static linkage",
3064 if (TREE_CODE (referent) == SCOPE_REF)
3065 referent = TREE_OPERAND (referent, 1);
3067 if (is_overloaded_fn (referent))
3068 /* We'll check that it has external linkage later. */
3070 else if (TREE_CODE (referent) != VAR_DECL)
3072 else if (!DECL_EXTERNAL_LINKAGE_P (referent))
3074 error ("address of non-extern `%E' cannot be used as template argument", referent);
3075 return error_mark_node;
3078 else if (INTEGRAL_TYPE_P (expr_type) || TYPE_PTR_TO_MEMBER_P (expr_type))
3080 if (! TREE_CONSTANT (expr))
3083 error ("non-constant `%E' cannot be used as template argument",
3091 error ("type '%T' cannot be used as a value for a non-type "
3092 "template-parameter", expr);
3093 else if (DECL_P (expr))
3094 error ("invalid use of '%D' as a non-type template-argument", expr);
3096 error ("invalid use of '%E' as a non-type template-argument", expr);
3101 switch (TREE_CODE (type))
3106 /* For a non-type template-parameter of integral or enumeration
3107 type, integral promotions (_conv.prom_) and integral
3108 conversions (_conv.integral_) are applied. */
3109 if (!INTEGRAL_TYPE_P (expr_type))
3110 return error_mark_node;
3112 /* It's safe to call digest_init in this case; we know we're
3113 just converting one integral constant expression to another. */
3114 expr = digest_init (type, expr, (tree*) 0);
3116 if (TREE_CODE (expr) != INTEGER_CST)
3117 /* Curiously, some TREE_CONSTANT integral expressions do not
3118 simplify to integer constants. For example, `3 % 0',
3119 remains a TRUNC_MOD_EXPR. */
3128 /* For a non-type template-parameter of type pointer to data
3129 member, qualification conversions (_conv.qual_) are
3131 e = perform_qualification_conversions (type, expr);
3132 if (TREE_CODE (e) == NOP_EXPR)
3133 /* The call to perform_qualification_conversions will
3134 insert a NOP_EXPR over EXPR to do express conversion,
3135 if necessary. But, that will confuse us if we use
3136 this (converted) template parameter to instantiate
3137 another template; then the thing will not look like a
3138 valid template argument. So, just make a new
3139 constant, of the appropriate type. */
3140 e = make_ptrmem_cst (type, PTRMEM_CST_MEMBER (expr));
3146 tree type_pointed_to = TREE_TYPE (type);
3148 if (TREE_CODE (type_pointed_to) == FUNCTION_TYPE)
3150 /* For a non-type template-parameter of type pointer to
3151 function, only the function-to-pointer conversion
3152 (_conv.func_) is applied. If the template-argument
3153 represents a set of overloaded functions (or a pointer to
3154 such), the matching function is selected from the set
3159 if (TREE_CODE (expr) == ADDR_EXPR)
3160 fns = TREE_OPERAND (expr, 0);
3164 fn = instantiate_type (type_pointed_to, fns, tf_none);
3166 if (fn == error_mark_node)
3167 return error_mark_node;
3169 if (!DECL_EXTERNAL_LINKAGE_P (fn))
3171 if (really_overloaded_fn (fns))
3172 return error_mark_node;
3177 expr = build_unary_op (ADDR_EXPR, fn, 0);
3179 my_friendly_assert (same_type_p (type, TREE_TYPE (expr)),
3185 /* For a non-type template-parameter of type pointer to
3186 object, qualification conversions (_conv.qual_) and the
3187 array-to-pointer conversion (_conv.array_) are applied.
3188 [Note: In particular, neither the null pointer conversion
3189 (_conv.ptr_) nor the derived-to-base conversion
3190 (_conv.ptr_) are applied. Although 0 is a valid
3191 template-argument for a non-type template-parameter of
3192 integral type, it is not a valid template-argument for a
3193 non-type template-parameter of pointer type.]
3195 The call to decay_conversion performs the
3196 array-to-pointer conversion, if appropriate. */
3197 expr = decay_conversion (expr);
3199 if (expr == error_mark_node)
3200 return error_mark_node;
3202 return perform_qualification_conversions (type, expr);
3207 case REFERENCE_TYPE:
3209 tree type_referred_to = TREE_TYPE (type);
3211 /* If this expression already has reference type, get the
3212 underlying object. */
3213 if (TREE_CODE (expr_type) == REFERENCE_TYPE)
3215 if (TREE_CODE (expr) == NOP_EXPR
3216 && TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR)
3218 my_friendly_assert (TREE_CODE (expr) == ADDR_EXPR, 20000604);
3219 expr = TREE_OPERAND (expr, 0);
3220 expr_type = TREE_TYPE (expr);
3223 if (TREE_CODE (type_referred_to) == FUNCTION_TYPE)
3225 /* For a non-type template-parameter of type reference to
3226 function, no conversions apply. If the
3227 template-argument represents a set of overloaded
3228 functions, the matching function is selected from the
3229 set (_over.over_). */
3232 fn = instantiate_type (type_referred_to, expr, tf_none);
3234 if (fn == error_mark_node)
3235 return error_mark_node;
3237 if (!DECL_EXTERNAL_LINKAGE_P (fn))
3239 if (really_overloaded_fn (expr))
3240 /* Don't issue an error here; we might get a different
3241 function if the overloading had worked out
3243 return error_mark_node;
3248 my_friendly_assert (same_type_p (type_referred_to,
3256 /* For a non-type template-parameter of type reference to
3257 object, no conversions apply. The type referred to by the
3258 reference may be more cv-qualified than the (otherwise
3259 identical) type of the template-argument. The
3260 template-parameter is bound directly to the
3261 template-argument, which must be an lvalue. */
3262 if (!same_type_p (TYPE_MAIN_VARIANT (expr_type),
3263 TYPE_MAIN_VARIANT (type_referred_to))
3264 || !at_least_as_qualified_p (type_referred_to,
3266 || !real_lvalue_p (expr))
3267 return error_mark_node;
3270 cxx_mark_addressable (expr);
3271 return build_nop (type, build_address (expr));
3277 my_friendly_assert (TYPE_PTRMEMFUNC_P (type), 20010112);
3279 /* For a non-type template-parameter of type pointer to member
3280 function, no conversions apply. If the template-argument
3281 represents a set of overloaded member functions, the
3282 matching member function is selected from the set
3285 if (!TYPE_PTRMEMFUNC_P (expr_type) &&
3286 expr_type != unknown_type_node)
3287 return error_mark_node;
3289 if (TREE_CODE (expr) == PTRMEM_CST)
3291 /* A ptr-to-member constant. */
3292 if (!same_type_p (type, expr_type))
3293 return error_mark_node;
3298 if (TREE_CODE (expr) != ADDR_EXPR)
3299 return error_mark_node;
3301 expr = instantiate_type (type, expr, tf_none);
3303 if (expr == error_mark_node)
3304 return error_mark_node;
3306 my_friendly_assert (same_type_p (type, TREE_TYPE (expr)),
3313 /* All non-type parameters must have one of these types. */
3318 return error_mark_node;
3321 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
3322 template template parameters. Both PARM_PARMS and ARG_PARMS are
3323 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
3326 ARG_PARMS may contain more parameters than PARM_PARMS. If this is
3327 the case, then extra parameters must have default arguments.
3329 Consider the example:
3330 template <class T, class Allocator = allocator> class vector;
3331 template<template <class U> class TT> class C;
3333 C<vector> is a valid instantiation. PARM_PARMS for the above code
3334 contains a TYPE_DECL (for U), ARG_PARMS contains two TYPE_DECLs (for
3335 T and Allocator) and OUTER_ARGS contains the argument that is used to
3336 substitute the TT parameter. */
3339 coerce_template_template_parms (tree parm_parms,
3341 tsubst_flags_t complain,
3345 int nparms, nargs, i;
3348 my_friendly_assert (TREE_CODE (parm_parms) == TREE_VEC, 0);
3349 my_friendly_assert (TREE_CODE (arg_parms) == TREE_VEC, 0);
3351 nparms = TREE_VEC_LENGTH (parm_parms);
3352 nargs = TREE_VEC_LENGTH (arg_parms);
3354 /* The rule here is opposite of coerce_template_parms. */
3357 && TREE_PURPOSE (TREE_VEC_ELT (arg_parms, nparms)) == NULL_TREE))
3360 for (i = 0; i < nparms; ++i)
3362 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
3363 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
3365 if (arg == NULL_TREE || arg == error_mark_node
3366 || parm == NULL_TREE || parm == error_mark_node)
3369 if (TREE_CODE (arg) != TREE_CODE (parm))
3372 switch (TREE_CODE (parm))
3378 /* We encounter instantiations of templates like
3379 template <template <template <class> class> class TT>
3382 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
3383 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
3385 if (!coerce_template_template_parms
3386 (parmparm, argparm, complain, in_decl, outer_args))
3392 /* The tsubst call is used to handle cases such as
3393 template <class T, template <T> class TT> class D;
3394 i.e. the parameter list of TT depends on earlier parameters. */
3396 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
3408 /* Convert the indicated template ARG as necessary to match the
3409 indicated template PARM. Returns the converted ARG, or
3410 error_mark_node if the conversion was unsuccessful. Error and
3411 warning messages are issued under control of COMPLAIN. This
3412 conversion is for the Ith parameter in the parameter list. ARGS is
3413 the full set of template arguments deduced so far. */
3416 convert_template_argument (tree parm,
3419 tsubst_flags_t complain,
3425 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
3427 inner_args = INNERMOST_TEMPLATE_ARGS (args);
3429 if (TREE_CODE (arg) == TREE_LIST
3430 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
3432 /* The template argument was the name of some
3433 member function. That's usually
3434 invalid, but static members are OK. In any
3435 case, grab the underlying fields/functions
3436 and issue an error later if required. */
3437 arg = TREE_VALUE (arg);
3438 TREE_TYPE (arg) = unknown_type_node;
3441 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
3442 requires_type = (TREE_CODE (parm) == TYPE_DECL
3443 || requires_tmpl_type);
3445 is_tmpl_type = ((TREE_CODE (arg) == TEMPLATE_DECL
3446 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
3447 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
3448 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
3451 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
3452 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
3453 arg = TYPE_STUB_DECL (arg);
3455 is_type = TYPE_P (arg) || is_tmpl_type;
3457 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
3458 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
3460 pedwarn ("to refer to a type member of a template parameter, use `typename %E'", arg);
3462 arg = make_typename_type (TREE_OPERAND (arg, 0),
3463 TREE_OPERAND (arg, 1),
3464 complain & tf_error);
3467 if (is_type != requires_type)
3471 if (complain & tf_error)
3473 error ("type/value mismatch at argument %d in template parameter list for `%D'",
3476 error (" expected a constant of type `%T', got `%T'",
3478 (is_tmpl_type ? DECL_NAME (arg) : arg));
3479 else if (requires_tmpl_type)
3480 error (" expected a class template, got `%E'", arg);
3482 error (" expected a type, got `%E'", arg);
3485 return error_mark_node;
3487 if (is_tmpl_type ^ requires_tmpl_type)
3489 if (in_decl && (complain & tf_error))
3491 error ("type/value mismatch at argument %d in template parameter list for `%D'",
3494 error (" expected a type, got `%T'", DECL_NAME (arg));
3496 error (" expected a class template, got `%T'", arg);
3498 return error_mark_node;
3503 if (requires_tmpl_type)
3505 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
3506 /* The number of argument required is not known yet.
3507 Just accept it for now. */
3508 val = TREE_TYPE (arg);
3511 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
3512 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
3514 if (coerce_template_template_parms (parmparm, argparm,
3520 /* TEMPLATE_TEMPLATE_PARM node is preferred over
3522 if (val != error_mark_node
3523 && DECL_TEMPLATE_TEMPLATE_PARM_P (val))
3524 val = TREE_TYPE (val);
3528 if (in_decl && (complain & tf_error))
3530 error ("type/value mismatch at argument %d in template parameter list for `%D'",
3532 error (" expected a template of type `%D', got `%D'", parm, arg);
3535 val = error_mark_node;
3540 val = groktypename (arg);
3544 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
3546 if (invalid_nontype_parm_type_p (t, complain))
3547 return error_mark_node;
3549 if (!uses_template_parms (arg) && !uses_template_parms (t))
3550 /* We used to call digest_init here. However, digest_init
3551 will report errors, which we don't want when complain
3552 is zero. More importantly, digest_init will try too
3553 hard to convert things: for example, `0' should not be
3554 converted to pointer type at this point according to
3555 the standard. Accepting this is not merely an
3556 extension, since deciding whether or not these
3557 conversions can occur is part of determining which
3558 function template to call, or whether a given explicit
3559 argument specification is valid. */
3560 val = convert_nontype_argument (t, arg);
3564 if (val == NULL_TREE)
3565 val = error_mark_node;
3566 else if (val == error_mark_node && (complain & tf_error))
3567 error ("could not convert template argument `%E' to `%T'",
3574 /* Convert all template arguments to their appropriate types, and
3575 return a vector containing the innermost resulting template
3576 arguments. If any error occurs, return error_mark_node. Error and
3577 warning messages are issued under control of COMPLAIN.
3579 If REQUIRE_ALL_ARGUMENTS is nonzero, all arguments must be
3580 provided in ARGLIST, or else trailing parameters must have default
3581 values. If REQUIRE_ALL_ARGUMENTS is zero, we will attempt argument
3582 deduction for any unspecified trailing arguments. */
3585 coerce_template_parms (tree parms,
3588 tsubst_flags_t complain,
3589 int require_all_arguments)
3591 int nparms, nargs, i, lost = 0;
3594 tree new_inner_args;
3596 inner_args = INNERMOST_TEMPLATE_ARGS (args);
3597 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
3598 nparms = TREE_VEC_LENGTH (parms);
3602 && require_all_arguments
3603 && TREE_PURPOSE (TREE_VEC_ELT (parms, nargs)) == NULL_TREE))
3605 if (complain & tf_error)
3607 error ("wrong number of template arguments (%d, should be %d)",
3611 cp_error_at ("provided for `%D'", in_decl);
3614 return error_mark_node;
3617 new_inner_args = make_tree_vec (nparms);
3618 new_args = add_outermost_template_args (args, new_inner_args);
3619 for (i = 0; i < nparms; i++)
3624 /* Get the Ith template parameter. */
3625 parm = TREE_VEC_ELT (parms, i);
3627 /* Calculate the Ith argument. */
3629 arg = TREE_VEC_ELT (inner_args, i);
3630 else if (require_all_arguments)
3631 /* There must be a default arg in this case. */
3632 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
3637 my_friendly_assert (arg, 20030727);
3638 if (arg == error_mark_node)
3639 error ("template argument %d is invalid", i + 1);
3641 arg = convert_template_argument (TREE_VALUE (parm),
3642 arg, new_args, complain, i,
3645 if (arg == error_mark_node)
3647 TREE_VEC_ELT (new_inner_args, i) = arg;
3651 return error_mark_node;
3653 return new_inner_args;
3656 /* Returns 1 if template args OT and NT are equivalent. */
3659 template_args_equal (tree ot, tree nt)
3664 if (TREE_CODE (nt) == TREE_VEC)
3665 /* For member templates */
3666 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
3667 else if (TYPE_P (nt))
3668 return TYPE_P (ot) && same_type_p (ot, nt);
3669 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
3672 return cp_tree_equal (ot, nt);
3675 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
3676 of template arguments. Returns 0 otherwise. */
3679 comp_template_args (tree oldargs, tree newargs)
3683 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
3686 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
3688 tree nt = TREE_VEC_ELT (newargs, i);
3689 tree ot = TREE_VEC_ELT (oldargs, i);
3691 if (! template_args_equal (ot, nt))
3697 /* Given class template name and parameter list, produce a user-friendly name
3698 for the instantiation. */
3701 mangle_class_name_for_template (const char* name, tree parms, tree arglist)
3703 static struct obstack scratch_obstack;
3704 static char *scratch_firstobj;
3707 if (!scratch_firstobj)
3708 gcc_obstack_init (&scratch_obstack);
3710 obstack_free (&scratch_obstack, scratch_firstobj);
3711 scratch_firstobj = obstack_alloc (&scratch_obstack, 1);
3713 #define ccat(C) obstack_1grow (&scratch_obstack, (C));
3714 #define cat(S) obstack_grow (&scratch_obstack, (S), strlen (S))
3718 nparms = TREE_VEC_LENGTH (parms);
3719 arglist = INNERMOST_TEMPLATE_ARGS (arglist);
3720 my_friendly_assert (nparms == TREE_VEC_LENGTH (arglist), 268);
3721 for (i = 0; i < nparms; i++)
3723 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
3724 tree arg = TREE_VEC_ELT (arglist, i);
3729 if (TREE_CODE (parm) == TYPE_DECL)
3731 cat (type_as_string (arg, TFF_CHASE_TYPEDEF));
3734 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3736 if (TREE_CODE (arg) == TEMPLATE_DECL)
3738 /* Already substituted with real template. Just output
3739 the template name here */
3740 tree context = DECL_CONTEXT (arg);
3743 /* The template may be defined in a namespace, or
3744 may be a member template. */
3745 my_friendly_assert (TREE_CODE (context) == NAMESPACE_DECL
3746 || CLASS_TYPE_P (context),
3748 cat(decl_as_string (DECL_CONTEXT (arg), TFF_PLAIN_IDENTIFIER));
3751 cat (IDENTIFIER_POINTER (DECL_NAME (arg)));
3754 /* Output the parameter declaration */
3755 cat (type_as_string (arg, TFF_CHASE_TYPEDEF));
3759 my_friendly_assert (TREE_CODE (parm) == PARM_DECL, 269);
3761 /* No need to check arglist against parmlist here; we did that
3762 in coerce_template_parms, called from lookup_template_class. */
3763 cat (expr_as_string (arg, TFF_PLAIN_IDENTIFIER));
3766 char *bufp = obstack_next_free (&scratch_obstack);
3768 while (bufp[offset - 1] == ' ')
3770 obstack_blank_fast (&scratch_obstack, offset);
3772 /* B<C<char> >, not B<C<char>> */
3773 if (bufp[offset - 1] == '>')
3778 return (char *) obstack_base (&scratch_obstack);
3782 classtype_mangled_name (tree t)
3784 if (CLASSTYPE_TEMPLATE_INFO (t)
3785 /* Specializations have already had their names set up in
3786 lookup_template_class. */
3787 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
3789 tree tmpl = most_general_template (CLASSTYPE_TI_TEMPLATE (t));
3791 /* For non-primary templates, the template parameters are
3792 implicit from their surrounding context. */
3793 if (PRIMARY_TEMPLATE_P (tmpl))
3795 tree name = DECL_NAME (tmpl);
3796 char *mangled_name = mangle_class_name_for_template
3797 (IDENTIFIER_POINTER (name),
3798 DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
3799 CLASSTYPE_TI_ARGS (t));
3800 tree id = get_identifier (mangled_name);
3801 IDENTIFIER_TEMPLATE (id) = name;
3806 return TYPE_IDENTIFIER (t);
3810 add_pending_template (tree d)
3812 tree ti = (TYPE_P (d)
3813 ? CLASSTYPE_TEMPLATE_INFO (d)
3814 : DECL_TEMPLATE_INFO (d));
3818 if (TI_PENDING_TEMPLATE_FLAG (ti))
3821 /* We are called both from instantiate_decl, where we've already had a
3822 tinst_level pushed, and instantiate_template, where we haven't.
3824 level = !(current_tinst_level && TINST_DECL (current_tinst_level) == d);
3827 push_tinst_level (d);
3829 pt = tree_cons (current_tinst_level, d, NULL_TREE);
3830 if (last_pending_template)
3831 TREE_CHAIN (last_pending_template) = pt;
3833 pending_templates = pt;
3835 last_pending_template = pt;
3837 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
3844 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
3845 ARGLIST. Valid choices for FNS are given in the cp-tree.def
3846 documentation for TEMPLATE_ID_EXPR. */
3849 lookup_template_function (tree fns, tree arglist)
3853 if (fns == error_mark_node || arglist == error_mark_node)
3854 return error_mark_node;
3856 my_friendly_assert (!arglist || TREE_CODE (arglist) == TREE_VEC, 20030726);
3857 if (fns == NULL_TREE)
3859 error ("non-template used as template");
3860 return error_mark_node;
3863 my_friendly_assert (TREE_CODE (fns) == TEMPLATE_DECL
3864 || TREE_CODE (fns) == OVERLOAD
3866 || TREE_CODE (fns) == IDENTIFIER_NODE,
3869 if (BASELINK_P (fns))
3871 BASELINK_FUNCTIONS (fns) = build (TEMPLATE_ID_EXPR,
3873 BASELINK_FUNCTIONS (fns),
3878 type = TREE_TYPE (fns);
3879 if (TREE_CODE (fns) == OVERLOAD || !type)
3880 type = unknown_type_node;
3882 return build (TEMPLATE_ID_EXPR, type, fns, arglist);
3885 /* Within the scope of a template class S<T>, the name S gets bound
3886 (in build_self_reference) to a TYPE_DECL for the class, not a
3887 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
3888 or one of its enclosing classes, and that type is a template,
3889 return the associated TEMPLATE_DECL. Otherwise, the original
3890 DECL is returned. */
3893 maybe_get_template_decl_from_type_decl (tree decl)
3895 return (decl != NULL_TREE
3896 && TREE_CODE (decl) == TYPE_DECL
3897 && DECL_ARTIFICIAL (decl)
3898 && CLASS_TYPE_P (TREE_TYPE (decl))
3899 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
3900 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
3903 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
3904 parameters, find the desired type.
3906 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
3908 IN_DECL, if non-NULL, is the template declaration we are trying to
3911 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
3912 the class we are looking up.
3914 Issue error and warning messages under control of COMPLAIN.
3916 If the template class is really a local class in a template
3917 function, then the FUNCTION_CONTEXT is the function in which it is
3918 being instantiated. */
3921 lookup_template_class (tree d1,
3926 tsubst_flags_t complain)
3928 tree template = NULL_TREE, parmlist;
3931 timevar_push (TV_NAME_LOOKUP);
3933 if (TREE_CODE (d1) == IDENTIFIER_NODE)
3935 if (IDENTIFIER_VALUE (d1)
3936 && DECL_TEMPLATE_TEMPLATE_PARM_P (IDENTIFIER_VALUE (d1)))
3937 template = IDENTIFIER_VALUE (d1);
3941 push_decl_namespace (context);
3942 template = lookup_name (d1, /*prefer_type=*/0);
3943 template = maybe_get_template_decl_from_type_decl (template);
3945 pop_decl_namespace ();
3948 context = DECL_CONTEXT (template);
3950 else if (TREE_CODE (d1) == TYPE_DECL && IS_AGGR_TYPE (TREE_TYPE (d1)))
3952 tree type = TREE_TYPE (d1);
3954 /* If we are declaring a constructor, say A<T>::A<T>, we will get
3955 an implicit typename for the second A. Deal with it. */
3956 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
3957 type = TREE_TYPE (type);
3959 if (CLASSTYPE_TEMPLATE_INFO (type))
3961 template = CLASSTYPE_TI_TEMPLATE (type);
3962 d1 = DECL_NAME (template);
3965 else if (TREE_CODE (d1) == ENUMERAL_TYPE
3966 || (TYPE_P (d1) && IS_AGGR_TYPE (d1)))
3968 template = TYPE_TI_TEMPLATE (d1);
3969 d1 = DECL_NAME (template);
3971 else if (TREE_CODE (d1) == TEMPLATE_DECL
3972 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
3975 d1 = DECL_NAME (template);
3976 context = DECL_CONTEXT (template);
3979 /* With something like `template <class T> class X class X { ... };'
3980 we could end up with D1 having nothing but an IDENTIFIER_VALUE.
3981 We don't want to do that, but we have to deal with the situation,
3982 so let's give them some syntax errors to chew on instead of a
3983 crash. Alternatively D1 might not be a template type at all. */
3986 if (complain & tf_error)
3987 error ("`%T' is not a template", d1);
3988 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
3991 if (TREE_CODE (template) != TEMPLATE_DECL
3992 /* Make sure it's a user visible template, if it was named by
3994 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (template)
3995 && !PRIMARY_TEMPLATE_P (template)))
3997 if (complain & tf_error)
3999 error ("non-template type `%T' used as a template", d1);
4001 cp_error_at ("for template declaration `%D'", in_decl);
4003 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4006 complain &= ~tf_user;
4008 if (DECL_TEMPLATE_TEMPLATE_PARM_P (template))
4010 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
4011 template arguments */
4016 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (template);
4018 /* Consider an example where a template template parameter declared as
4020 template <class T, class U = std::allocator<T> > class TT
4022 The template parameter level of T and U are one level larger than
4023 of TT. To proper process the default argument of U, say when an
4024 instantiation `TT<int>' is seen, we need to build the full
4025 arguments containing {int} as the innermost level. Outer levels,
4026 available when not appearing as default template argument, can be
4027 obtained from `current_template_args ()'.
4029 Suppose that TT is later substituted with std::vector. The above
4030 instantiation is `TT<int, std::allocator<T> >' with TT at
4031 level 1, and T at level 2, while the template arguments at level 1
4032 becomes {std::vector} and the inner level 2 is {int}. */
4034 if (current_template_parms)
4035 arglist = add_to_template_args (current_template_args (), arglist);
4037 arglist2 = coerce_template_parms (parmlist, arglist, template,
4038 complain, /*require_all_args=*/1);
4039 if (arglist2 == error_mark_node
4040 || (!uses_template_parms (arglist2)
4041 && check_instantiated_args (template, arglist2, complain)))
4042 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4044 parm = bind_template_template_parm (TREE_TYPE (template), arglist2);
4045 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
4049 tree template_type = TREE_TYPE (template);
4052 tree found = NULL_TREE;
4056 int is_partial_instantiation;
4058 gen_tmpl = most_general_template (template);
4059 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
4060 parm_depth = TMPL_PARMS_DEPTH (parmlist);
4061 arg_depth = TMPL_ARGS_DEPTH (arglist);
4063 if (arg_depth == 1 && parm_depth > 1)
4065 /* We've been given an incomplete set of template arguments.
4068 template <class T> struct S1 {
4069 template <class U> struct S2 {};
4070 template <class U> struct S2<U*> {};
4073 we will be called with an ARGLIST of `U*', but the
4074 TEMPLATE will be `template <class T> template
4075 <class U> struct S1<T>::S2'. We must fill in the missing
4078 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (template)),
4080 arg_depth = TMPL_ARGS_DEPTH (arglist);
4083 /* Now we should have enough arguments. */
4084 my_friendly_assert (parm_depth == arg_depth, 0);
4086 /* From here on, we're only interested in the most general
4088 template = gen_tmpl;
4090 /* Calculate the BOUND_ARGS. These will be the args that are
4091 actually tsubst'd into the definition to create the
4095 /* We have multiple levels of arguments to coerce, at once. */
4097 int saved_depth = TMPL_ARGS_DEPTH (arglist);
4099 tree bound_args = make_tree_vec (parm_depth);
4101 for (i = saved_depth,
4102 t = DECL_TEMPLATE_PARMS (template);
4103 i > 0 && t != NULL_TREE;
4104 --i, t = TREE_CHAIN (t))
4106 tree a = coerce_template_parms (TREE_VALUE (t),
4108 complain, /*require_all_args=*/1);
4110 /* Don't process further if one of the levels fails. */
4111 if (a == error_mark_node)
4113 /* Restore the ARGLIST to its full size. */
4114 TREE_VEC_LENGTH (arglist) = saved_depth;
4115 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4118 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
4120 /* We temporarily reduce the length of the ARGLIST so
4121 that coerce_template_parms will see only the arguments
4122 corresponding to the template parameters it is
4124 TREE_VEC_LENGTH (arglist)--;
4127 /* Restore the ARGLIST to its full size. */
4128 TREE_VEC_LENGTH (arglist) = saved_depth;
4130 arglist = bound_args;
4134 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
4135 INNERMOST_TEMPLATE_ARGS (arglist),
4137 complain, /*require_all_args=*/1);
4139 if (arglist == error_mark_node
4140 || (!uses_template_parms (INNERMOST_TEMPLATE_ARGS (arglist))
4141 && check_instantiated_args (template,
4142 INNERMOST_TEMPLATE_ARGS (arglist),
4144 /* We were unable to bind the arguments. */
4145 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
4147 /* In the scope of a template class, explicit references to the
4148 template class refer to the type of the template, not any
4149 instantiation of it. For example, in:
4151 template <class T> class C { void f(C<T>); }
4153 the `C<T>' is just the same as `C'. Outside of the
4154 class, however, such a reference is an instantiation. */
4155 if (comp_template_args (TYPE_TI_ARGS (template_type),
4158 found = template_type;
4160 if (!entering_scope && PRIMARY_TEMPLATE_P (template))
4164 for (ctx = current_class_type;
4166 ctx = TYPE_CONTEXT (ctx))
4168 if (TREE_CODE (ctx) == NAMESPACE_DECL)
4170 if (same_type_p (ctx, template_type))
4174 /* We're not in the scope of the class, so the
4175 TEMPLATE_TYPE is not the type we want after all. */
4181 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
4183 for (tp = &DECL_TEMPLATE_INSTANTIATIONS (template);
4185 tp = &TREE_CHAIN (*tp))
4186 if (comp_template_args (TREE_PURPOSE (*tp), arglist))
4190 /* Use the move-to-front heuristic to speed up future
4192 *tp = TREE_CHAIN (*tp);
4194 = DECL_TEMPLATE_INSTANTIATIONS (template);
4195 DECL_TEMPLATE_INSTANTIATIONS (template) = found;
4197 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, TREE_VALUE (found));
4200 /* This type is a "partial instantiation" if any of the template
4201 arguments still involve template parameters. Note that we set
4202 IS_PARTIAL_INSTANTIATION for partial specializations as
4204 is_partial_instantiation = uses_template_parms (arglist);
4206 if (!is_partial_instantiation
4207 && !PRIMARY_TEMPLATE_P (template)
4208 && TREE_CODE (CP_DECL_CONTEXT (template)) == NAMESPACE_DECL)
4210 found = xref_tag_from_type (TREE_TYPE (template),
4211 DECL_NAME (template),
4213 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
4216 context = tsubst (DECL_CONTEXT (template), arglist,
4219 context = global_namespace;
4221 /* Create the type. */
4222 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
4224 if (!is_partial_instantiation)
4226 set_current_access_from_decl (TYPE_NAME (template_type));
4227 t = start_enum (TYPE_IDENTIFIER (template_type));
4230 /* We don't want to call start_enum for this type, since
4231 the values for the enumeration constants may involve
4232 template parameters. And, no one should be interested
4233 in the enumeration constants for such a type. */
4234 t = make_node (ENUMERAL_TYPE);
4238 t = make_aggr_type (TREE_CODE (template_type));
4239 CLASSTYPE_DECLARED_CLASS (t)
4240 = CLASSTYPE_DECLARED_CLASS (template_type);
4241 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
4242 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
4244 /* A local class. Make sure the decl gets registered properly. */
4245 if (context == current_function_decl)
4246 pushtag (DECL_NAME (template), t, 0);
4249 /* If we called start_enum or pushtag above, this information
4250 will already be set up. */
4253 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
4255 type_decl = create_implicit_typedef (DECL_NAME (template), t);
4256 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
4257 TYPE_STUB_DECL (t) = type_decl;
4258 DECL_SOURCE_LOCATION (type_decl)
4259 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
4262 type_decl = TYPE_NAME (t);
4264 TREE_PRIVATE (type_decl)
4265 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
4266 TREE_PROTECTED (type_decl)
4267 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
4269 /* Set up the template information. We have to figure out which
4270 template is the immediate parent if this is a full
4272 if (parm_depth == 1 || is_partial_instantiation
4273 || !PRIMARY_TEMPLATE_P (template))
4274 /* This case is easy; there are no member templates involved. */
4278 /* This is a full instantiation of a member template. Look
4279 for a partial instantiation of which this is an instance. */
4281 for (found = DECL_TEMPLATE_INSTANTIATIONS (template);
4282 found; found = TREE_CHAIN (found))
4285 tree tmpl = CLASSTYPE_TI_TEMPLATE (TREE_VALUE (found));
4287 /* We only want partial instantiations, here, not
4288 specializations or full instantiations. */
4289 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_VALUE (found))
4290 || !uses_template_parms (TREE_VALUE (found)))
4293 /* Temporarily reduce by one the number of levels in the
4294 ARGLIST and in FOUND so as to avoid comparing the
4295 last set of arguments. */
4296 TREE_VEC_LENGTH (arglist)--;
4297 TREE_VEC_LENGTH (TREE_PURPOSE (found)) --;
4299 /* See if the arguments match. If they do, then TMPL is
4300 the partial instantiation we want. */
4301 success = comp_template_args (TREE_PURPOSE (found), arglist);
4303 /* Restore the argument vectors to their full size. */
4304 TREE_VEC_LENGTH (arglist)++;
4305 TREE_VEC_LENGTH (TREE_PURPOSE (found))++;
4316 /* There was no partial instantiation. This happens
4317 where C<T> is a member template of A<T> and it's used
4320 template <typename T> struct B { A<T>::C<int> m; };
4323 Create the partial instantiation.
4325 TREE_VEC_LENGTH (arglist)--;
4326 found = tsubst (template, arglist, complain, NULL_TREE);
4327 TREE_VEC_LENGTH (arglist)++;
4331 SET_TYPE_TEMPLATE_INFO (t, tree_cons (found, arglist, NULL_TREE));
4332 DECL_TEMPLATE_INSTANTIATIONS (template)
4333 = tree_cons (arglist, t,
4334 DECL_TEMPLATE_INSTANTIATIONS (template));
4336 if (TREE_CODE (t) == ENUMERAL_TYPE
4337 && !is_partial_instantiation)
4338 /* Now that the type has been registered on the instantiations
4339 list, we set up the enumerators. Because the enumeration
4340 constants may involve the enumeration type itself, we make
4341 sure to register the type first, and then create the
4342 constants. That way, doing tsubst_expr for the enumeration
4343 constants won't result in recursive calls here; we'll find
4344 the instantiation and exit above. */
4345 tsubst_enum (template_type, t, arglist);
4347 /* Reset the name of the type, now that CLASSTYPE_TEMPLATE_INFO
4349 if (TREE_CODE (t) != ENUMERAL_TYPE)
4350 DECL_NAME (type_decl) = classtype_mangled_name (t);
4351 if (!is_partial_instantiation)
4353 /* For backwards compatibility; code that uses
4354 -fexternal-templates expects looking up a template to
4355 instantiate it. I think DDD still relies on this.
4356 (jason 8/20/1998) */
4357 if (TREE_CODE (t) != ENUMERAL_TYPE
4358 && flag_external_templates
4359 && CLASSTYPE_INTERFACE_KNOWN (TREE_TYPE (template))
4360 && ! CLASSTYPE_INTERFACE_ONLY (TREE_TYPE (template)))
4361 add_pending_template (t);
4364 /* If the type makes use of template parameters, the
4365 code that generates debugging information will crash. */
4366 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
4368 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
4370 timevar_pop (TV_NAME_LOOKUP);
4380 /* Called from for_each_template_parm via walk_tree. */
4383 for_each_template_parm_r (tree* tp, int* walk_subtrees, void* d)
4386 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
4387 tree_fn_t fn = pfd->fn;
4388 void *data = pfd->data;
4391 /* If we have already visited this tree, there's no need to walk
4392 subtrees. Otherwise, add it to the visited table. */
4393 slot = htab_find_slot (pfd->visited, *tp, INSERT);
4402 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited))
4403 return error_mark_node;
4405 switch (TREE_CODE (t))
4408 if (TYPE_PTRMEMFUNC_P (t))
4414 if (!TYPE_TEMPLATE_INFO (t))
4416 else if (for_each_template_parm (TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
4417 fn, data, pfd->visited))
4418 return error_mark_node;
4422 /* Since we're not going to walk subtrees, we have to do this
4424 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
4426 return error_mark_node;
4430 /* Check the return type. */
4431 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited))
4432 return error_mark_node;
4434 /* Check the parameter types. Since default arguments are not
4435 instantiated until they are needed, the TYPE_ARG_TYPES may
4436 contain expressions that involve template parameters. But,
4437 no-one should be looking at them yet. And, once they're
4438 instantiated, they don't contain template parameters, so
4439 there's no point in looking at them then, either. */
4443 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
4444 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
4446 return error_mark_node;
4448 /* Since we've already handled the TYPE_ARG_TYPES, we don't
4449 want walk_tree walking into them itself. */
4455 if (for_each_template_parm (TYPE_FIELDS (t), fn, data,
4457 return error_mark_node;
4462 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
4463 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
4465 return error_mark_node;
4470 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
4471 && for_each_template_parm (DECL_INITIAL (t), fn, data,
4473 return error_mark_node;
4474 if (DECL_CONTEXT (t)
4475 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
4477 return error_mark_node;
4480 case BOUND_TEMPLATE_TEMPLATE_PARM:
4481 /* Record template parameters such as `T' inside `TT<T>'. */
4482 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited))
4483 return error_mark_node;
4486 case TEMPLATE_TEMPLATE_PARM:
4487 case TEMPLATE_TYPE_PARM:
4488 case TEMPLATE_PARM_INDEX:
4489 if (fn && (*fn)(t, data))
4490 return error_mark_node;
4492 return error_mark_node;
4496 /* A template template parameter is encountered */
4497 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
4498 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited))
4499 return error_mark_node;
4501 /* Already substituted template template parameter */
4507 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
4508 data, pfd->visited))
4509 return error_mark_node;
4513 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
4514 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
4515 (TREE_TYPE (t)), fn, data,
4517 return error_mark_node;
4522 /* If there's no type, then this thing must be some expression
4523 involving template parameters. */
4524 if (!fn && !TREE_TYPE (t))
4525 return error_mark_node;
4530 case REINTERPRET_CAST_EXPR:
4531 case CONST_CAST_EXPR:
4532 case STATIC_CAST_EXPR:
4533 case DYNAMIC_CAST_EXPR:
4537 case PSEUDO_DTOR_EXPR:
4539 return error_mark_node;
4543 /* If we do not handle this case specially, we end up walking
4544 the BINFO hierarchy, which is circular, and therefore
4545 confuses walk_tree. */
4547 if (for_each_template_parm (BASELINK_FUNCTIONS (*tp), fn, data,
4549 return error_mark_node;
4556 /* We didn't find any template parameters we liked. */
4560 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
4561 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
4562 call FN with the parameter and the DATA.
4563 If FN returns nonzero, the iteration is terminated, and
4564 for_each_template_parm returns 1. Otherwise, the iteration
4565 continues. If FN never returns a nonzero value, the value
4566 returned by for_each_template_parm is 0. If FN is NULL, it is
4567 considered to be the function which always returns 1. */
4570 for_each_template_parm (tree t, tree_fn_t fn, void* data, htab_t visited)
4572 struct pair_fn_data pfd;
4579 /* Walk the tree. (Conceptually, we would like to walk without
4580 duplicates, but for_each_template_parm_r recursively calls
4581 for_each_template_parm, so we would need to reorganize a fair
4582 bit to use walk_tree_without_duplicates, so we keep our own
4585 pfd.visited = visited;
4587 pfd.visited = htab_create (37, htab_hash_pointer, htab_eq_pointer,
4589 result = walk_tree (&t,
4590 for_each_template_parm_r,
4596 htab_delete (pfd.visited);
4602 uses_template_parms (tree t)
4604 return for_each_template_parm (t, 0, 0, NULL);
4607 static int tinst_depth;
4608 extern int max_tinst_depth;
4609 #ifdef GATHER_STATISTICS
4612 static int tinst_level_tick;
4613 static int last_template_error_tick;
4615 /* We're starting to instantiate D; record the template instantiation context
4616 for diagnostics and to restore it later. */
4619 push_tinst_level (tree d)
4623 if (tinst_depth >= max_tinst_depth)
4625 /* If the instantiation in question still has unbound template parms,
4626 we don't really care if we can't instantiate it, so just return.
4627 This happens with base instantiation for implicit `typename'. */
4628 if (uses_template_parms (d))
4631 last_template_error_tick = tinst_level_tick;
4632 error ("template instantiation depth exceeds maximum of %d (use -ftemplate-depth-NN to increase the maximum) instantiating `%D'",
4633 max_tinst_depth, d);
4635 print_instantiation_context ();
4640 new = build_expr_wfl (d, input_filename, input_line, 0);
4641 TREE_CHAIN (new) = current_tinst_level;
4642 current_tinst_level = new;
4645 #ifdef GATHER_STATISTICS
4646 if (tinst_depth > depth_reached)
4647 depth_reached = tinst_depth;
4654 /* We're done instantiating this template; return to the instantiation
4658 pop_tinst_level (void)
4660 tree old = current_tinst_level;
4662 /* Restore the filename and line number stashed away when we started
4663 this instantiation. */
4664 input_line = TINST_LINE (old);
4665 input_filename = TINST_FILE (old);
4666 extract_interface_info ();
4668 current_tinst_level = TREE_CHAIN (old);
4673 /* We're instantiating a deferred template; restore the template
4674 instantiation context in which the instantiation was requested, which
4675 is one step out from LEVEL. */
4678 reopen_tinst_level (tree level)
4683 for (t = level; t; t = TREE_CHAIN (t))
4686 current_tinst_level = level;
4690 /* Return the outermost template instantiation context, for use with
4691 -falt-external-templates. */
4694 tinst_for_decl (void)
4696 tree p = current_tinst_level;
4699 for (; TREE_CHAIN (p) ; p = TREE_CHAIN (p))
4704 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
4705 vector of template arguments, as for tsubst.
4707 Returns an appropriate tsubst'd friend declaration. */
4710 tsubst_friend_function (tree decl, tree args)
4713 location_t saved_loc = input_location;
4715 input_location = DECL_SOURCE_LOCATION (decl);
4717 if (TREE_CODE (decl) == FUNCTION_DECL
4718 && DECL_TEMPLATE_INSTANTIATION (decl)
4719 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
4720 /* This was a friend declared with an explicit template
4721 argument list, e.g.:
4725 to indicate that f was a template instantiation, not a new
4726 function declaration. Now, we have to figure out what
4727 instantiation of what template. */
4729 tree template_id, arglist, fns;
4732 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
4734 /* Friend functions are looked up in the containing namespace scope.
4735 We must enter that scope, to avoid finding member functions of the
4736 current cless with same name. */
4737 push_nested_namespace (ns);
4738 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
4739 tf_error | tf_warning, NULL_TREE);
4740 pop_nested_namespace (ns);
4741 arglist = tsubst (DECL_TI_ARGS (decl), args,
4742 tf_error | tf_warning, NULL_TREE);
4743 template_id = lookup_template_function (fns, arglist);
4745 new_friend = tsubst (decl, args, tf_error | tf_warning, NULL_TREE);
4746 tmpl = determine_specialization (template_id, new_friend,
4748 /*need_member_template=*/0);
4749 new_friend = instantiate_template (tmpl, new_args, tf_error);
4753 new_friend = tsubst (decl, args, tf_error | tf_warning, NULL_TREE);
4755 /* The NEW_FRIEND will look like an instantiation, to the
4756 compiler, but is not an instantiation from the point of view of
4757 the language. For example, we might have had:
4759 template <class T> struct S {
4760 template <class U> friend void f(T, U);
4763 Then, in S<int>, template <class U> void f(int, U) is not an
4764 instantiation of anything. */
4765 DECL_USE_TEMPLATE (new_friend) = 0;
4766 if (TREE_CODE (decl) == TEMPLATE_DECL)
4768 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
4769 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
4770 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
4773 /* The mangled name for the NEW_FRIEND is incorrect. The function
4774 is not a template instantiation and should not be mangled like
4775 one. Therefore, we forget the mangling here; we'll recompute it
4776 later if we need it. */
4777 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
4779 SET_DECL_RTL (new_friend, NULL_RTX);
4780 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
4783 if (DECL_NAMESPACE_SCOPE_P (new_friend))
4786 tree new_friend_template_info;
4787 tree new_friend_result_template_info;
4789 int new_friend_is_defn;
4791 /* We must save some information from NEW_FRIEND before calling
4792 duplicate decls since that function will free NEW_FRIEND if
4794 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
4795 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
4797 /* This declaration is a `primary' template. */
4798 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
4801 = DECL_INITIAL (DECL_TEMPLATE_RESULT (new_friend)) != NULL_TREE;
4802 new_friend_result_template_info
4803 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
4807 new_friend_is_defn = DECL_INITIAL (new_friend) != NULL_TREE;
4808 new_friend_result_template_info = NULL_TREE;
4811 /* Inside pushdecl_namespace_level, we will push into the
4812 current namespace. However, the friend function should go
4813 into the namespace of the template. */
4814 ns = decl_namespace_context (new_friend);
4815 push_nested_namespace (ns);
4816 old_decl = pushdecl_namespace_level (new_friend);
4817 pop_nested_namespace (ns);
4819 if (old_decl != new_friend)
4821 /* This new friend declaration matched an existing
4822 declaration. For example, given:
4824 template <class T> void f(T);
4825 template <class U> class C {
4826 template <class T> friend void f(T) {}
4829 the friend declaration actually provides the definition
4830 of `f', once C has been instantiated for some type. So,
4831 old_decl will be the out-of-class template declaration,
4832 while new_friend is the in-class definition.
4834 But, if `f' was called before this point, the
4835 instantiation of `f' will have DECL_TI_ARGS corresponding
4836 to `T' but not to `U', references to which might appear
4837 in the definition of `f'. Previously, the most general
4838 template for an instantiation of `f' was the out-of-class
4839 version; now it is the in-class version. Therefore, we
4840 run through all specialization of `f', adding to their
4841 DECL_TI_ARGS appropriately. In particular, they need a
4842 new set of outer arguments, corresponding to the
4843 arguments for this class instantiation.
4845 The same situation can arise with something like this:
4848 template <class T> class C {
4852 when `C<int>' is instantiated. Now, `f(int)' is defined
4855 if (!new_friend_is_defn)
4856 /* On the other hand, if the in-class declaration does
4857 *not* provide a definition, then we don't want to alter
4858 existing definitions. We can just leave everything
4863 /* Overwrite whatever template info was there before, if
4864 any, with the new template information pertaining to
4866 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
4868 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
4869 reregister_specialization (new_friend,
4870 most_general_template (old_decl),
4875 tree new_friend_args;
4877 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
4878 = new_friend_result_template_info;
4880 new_friend_args = TI_ARGS (new_friend_template_info);
4881 for (t = DECL_TEMPLATE_SPECIALIZATIONS (old_decl);
4885 tree spec = TREE_VALUE (t);
4888 = add_outermost_template_args (new_friend_args,
4889 DECL_TI_ARGS (spec));
4892 /* Now, since specializations are always supposed to
4893 hang off of the most general template, we must move
4895 t = most_general_template (old_decl);
4898 DECL_TEMPLATE_SPECIALIZATIONS (t)
4899 = chainon (DECL_TEMPLATE_SPECIALIZATIONS (t),
4900 DECL_TEMPLATE_SPECIALIZATIONS (old_decl));
4901 DECL_TEMPLATE_SPECIALIZATIONS (old_decl) = NULL_TREE;
4906 /* The information from NEW_FRIEND has been merged into OLD_DECL
4907 by duplicate_decls. */
4908 new_friend = old_decl;
4911 else if (COMPLETE_TYPE_P (DECL_CONTEXT (new_friend)))
4913 /* Check to see that the declaration is really present, and,
4914 possibly obtain an improved declaration. */
4915 tree fn = check_classfn (DECL_CONTEXT (new_friend),
4923 input_location = saved_loc;
4927 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
4928 template arguments, as for tsubst.
4930 Returns an appropriate tsubst'd friend type or error_mark_node on
4934 tsubst_friend_class (tree friend_tmpl, tree args)
4940 context = DECL_CONTEXT (friend_tmpl);
4944 if (TREE_CODE (context) == NAMESPACE_DECL)
4945 push_nested_namespace (context);
4947 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
4950 /* First, we look for a class template. */
4951 tmpl = lookup_name (DECL_NAME (friend_tmpl), /*prefer_type=*/0);
4953 /* But, if we don't find one, it might be because we're in a
4954 situation like this:
4962 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
4963 for `S<int>', not the TEMPLATE_DECL. */
4964 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
4966 tmpl = lookup_name (DECL_NAME (friend_tmpl), /*prefer_type=*/1);
4967 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
4970 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
4972 /* The friend template has already been declared. Just
4973 check to see that the declarations match, and install any new
4974 default parameters. We must tsubst the default parameters,
4975 of course. We only need the innermost template parameters
4976 because that is all that redeclare_class_template will look
4978 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
4979 > TMPL_ARGS_DEPTH (args))
4982 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
4983 args, tf_error | tf_warning);
4984 redeclare_class_template (TREE_TYPE (tmpl), parms);
4987 friend_type = TREE_TYPE (tmpl);
4991 /* The friend template has not already been declared. In this
4992 case, the instantiation of the template class will cause the
4993 injection of this template into the global scope. */
4994 tmpl = tsubst (friend_tmpl, args, tf_error | tf_warning, NULL_TREE);
4996 /* The new TMPL is not an instantiation of anything, so we
4997 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
4998 the new type because that is supposed to be the corresponding
4999 template decl, i.e., TMPL. */
5000 DECL_USE_TEMPLATE (tmpl) = 0;
5001 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
5002 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
5004 /* Inject this template into the global scope. */
5005 friend_type = TREE_TYPE (pushdecl_top_level (tmpl));
5010 if (TREE_CODE (context) == NAMESPACE_DECL)
5011 pop_nested_namespace (context);
5013 pop_nested_class ();
5019 /* Returns zero if TYPE cannot be completed later due to circularity.
5020 Otherwise returns one. */
5023 can_complete_type_without_circularity (tree type)
5025 if (type == NULL_TREE || type == error_mark_node)
5027 else if (COMPLETE_TYPE_P (type))
5029 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
5030 return can_complete_type_without_circularity (TREE_TYPE (type));
5031 else if (CLASS_TYPE_P (type)
5032 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
5039 instantiate_class_template (tree type)
5041 tree template, args, pattern, t, member;
5045 if (type == error_mark_node)
5046 return error_mark_node;
5048 if (TYPE_BEING_DEFINED (type)
5049 || COMPLETE_TYPE_P (type)
5050 || dependent_type_p (type))
5053 /* Figure out which template is being instantiated. */
5054 template = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
5055 my_friendly_assert (TREE_CODE (template) == TEMPLATE_DECL, 279);
5057 /* Figure out which arguments are being used to do the
5059 args = CLASSTYPE_TI_ARGS (type);
5061 /* Determine what specialization of the original template to
5063 t = most_specialized_class (template, args);
5064 if (t == error_mark_node)
5066 const char *str = "candidates are:";
5067 error ("ambiguous class template instantiation for `%#T'", type);
5068 for (t = DECL_TEMPLATE_SPECIALIZATIONS (template); t;
5071 if (get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t), args))
5073 cp_error_at ("%s %+#T", str, TREE_TYPE (t));
5077 TYPE_BEING_DEFINED (type) = 1;
5078 return error_mark_node;
5082 pattern = TREE_TYPE (t);
5084 pattern = TREE_TYPE (template);
5086 /* If the template we're instantiating is incomplete, then clearly
5087 there's nothing we can do. */
5088 if (!COMPLETE_TYPE_P (pattern))
5091 /* If we've recursively instantiated too many templates, stop. */
5092 if (! push_tinst_level (type))
5095 /* Now we're really doing the instantiation. Mark the type as in
5096 the process of being defined. */
5097 TYPE_BEING_DEFINED (type) = 1;
5099 /* We may be in the middle of deferred access check. Disable
5101 push_deferring_access_checks (dk_no_deferred);
5103 maybe_push_to_top_level (uses_template_parms (type));
5107 /* This TYPE is actually an instantiation of a partial
5108 specialization. We replace the innermost set of ARGS with
5109 the arguments appropriate for substitution. For example,
5112 template <class T> struct S {};
5113 template <class T> struct S<T*> {};
5115 and supposing that we are instantiating S<int*>, ARGS will
5116 present be {int*} but we need {int}. */
5118 = get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t),
5121 /* If there were multiple levels in ARGS, replacing the
5122 innermost level would alter CLASSTYPE_TI_ARGS, which we don't
5123 want, so we make a copy first. */
5124 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
5126 args = copy_node (args);
5127 SET_TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args), inner_args);
5133 if (flag_external_templates)
5135 if (flag_alt_external_templates)
5137 CLASSTYPE_INTERFACE_ONLY (type) = interface_only;
5138 SET_CLASSTYPE_INTERFACE_UNKNOWN_X (type, interface_unknown);
5142 CLASSTYPE_INTERFACE_ONLY (type) = CLASSTYPE_INTERFACE_ONLY (pattern);
5143 SET_CLASSTYPE_INTERFACE_UNKNOWN_X
5144 (type, CLASSTYPE_INTERFACE_UNKNOWN (pattern));
5149 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
5152 /* Set the input location to the template definition. This is needed
5153 if tsubsting causes an error. */
5154 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (pattern));
5156 TYPE_HAS_CONSTRUCTOR (type) = TYPE_HAS_CONSTRUCTOR (pattern);
5157 TYPE_HAS_DESTRUCTOR (type) = TYPE_HAS_DESTRUCTOR (pattern);
5158 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
5159 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
5160 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
5161 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
5162 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
5163 TYPE_HAS_ABSTRACT_ASSIGN_REF (type) = TYPE_HAS_ABSTRACT_ASSIGN_REF (pattern);
5164 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
5165 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
5166 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
5167 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
5168 TYPE_BASE_CONVS_MAY_REQUIRE_CODE_P (type)
5169 = TYPE_BASE_CONVS_MAY_REQUIRE_CODE_P (pattern);
5170 TYPE_USES_MULTIPLE_INHERITANCE (type)
5171 = TYPE_USES_MULTIPLE_INHERITANCE (pattern);
5172 TYPE_USES_VIRTUAL_BASECLASSES (type)
5173 = TYPE_USES_VIRTUAL_BASECLASSES (pattern);
5174 TYPE_PACKED (type) = TYPE_PACKED (pattern);
5175 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
5176 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
5177 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
5178 if (ANON_AGGR_TYPE_P (pattern))
5179 SET_ANON_AGGR_TYPE_P (type);
5181 pbinfo = TYPE_BINFO (pattern);
5183 if (BINFO_BASETYPES (pbinfo))
5185 tree base_list = NULL_TREE;
5186 tree pbases = BINFO_BASETYPES (pbinfo);
5187 tree paccesses = BINFO_BASEACCESSES (pbinfo);
5188 tree context = TYPE_CONTEXT (type);
5191 /* We must enter the scope containing the type, as that is where
5192 the accessibility of types named in dependent bases are
5194 push_scope (context ? context : global_namespace);
5196 /* Substitute into each of the bases to determine the actual
5198 for (i = 0; i < TREE_VEC_LENGTH (pbases); ++i)
5204 pbase = TREE_VEC_ELT (pbases, i);
5205 access = TREE_VEC_ELT (paccesses, i);
5207 /* Substitute to figure out the base class. */
5208 base = tsubst (BINFO_TYPE (pbase), args, tf_error, NULL_TREE);
5209 if (base == error_mark_node)
5212 base_list = tree_cons (access, base, base_list);
5213 TREE_VIA_VIRTUAL (base_list) = TREE_VIA_VIRTUAL (pbase);
5216 /* The list is now in reverse order; correct that. */
5217 base_list = nreverse (base_list);
5219 /* Now call xref_basetypes to set up all the base-class
5221 xref_basetypes (type, base_list);
5223 pop_scope (context ? context : global_namespace);
5226 /* Now that our base classes are set up, enter the scope of the
5227 class, so that name lookups into base classes, etc. will work
5228 correctly. This is precisely analogous to what we do in
5229 begin_class_definition when defining an ordinary non-template
5233 /* Now members are processed in the order of declaration. */
5234 for (member = CLASSTYPE_DECL_LIST (pattern);
5235 member; member = TREE_CHAIN (member))
5237 tree t = TREE_VALUE (member);
5239 if (TREE_PURPOSE (member))
5243 /* Build new CLASSTYPE_NESTED_UTDS. */
5246 tree name = TYPE_IDENTIFIER (tag);
5249 newtag = tsubst (tag, args, tf_error, NULL_TREE);
5250 my_friendly_assert (newtag != error_mark_node, 20010206);
5251 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
5253 if (TYPE_LANG_SPECIFIC (tag) && CLASSTYPE_IS_TEMPLATE (tag))
5254 /* Unfortunately, lookup_template_class sets
5255 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
5256 instantiation (i.e., for the type of a member template
5257 class nested within a template class.) This behavior is
5258 required for maybe_process_partial_specialization to work
5259 correctly, but is not accurate in this case; the TAG is not
5260 an instantiation of anything. (The corresponding
5261 TEMPLATE_DECL is an instantiation, but the TYPE is not.) */
5262 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
5264 /* Now, we call pushtag to put this NEWTAG into the scope of
5265 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
5266 pushtag calling push_template_decl. We don't have to do
5267 this for enums because it will already have been done in
5270 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
5271 pushtag (name, newtag, /*globalize=*/0);
5274 else if (TREE_CODE (t) == FUNCTION_DECL
5275 || DECL_FUNCTION_TEMPLATE_P (t))
5277 /* Build new TYPE_METHODS. */
5279 tree r = tsubst (t, args, tf_error, NULL_TREE);
5280 set_current_access_from_decl (r);
5281 grok_special_member_properties (r);
5282 finish_member_declaration (r);
5286 /* Build new TYPE_FIELDS. */
5288 if (TREE_CODE (t) != CONST_DECL)
5292 /* The the file and line for this declaration, to
5293 assist in error message reporting. Since we
5294 called push_tinst_level above, we don't need to
5296 input_location = DECL_SOURCE_LOCATION (t);
5298 if (TREE_CODE (t) == TEMPLATE_DECL)
5299 processing_template_decl++;
5300 r = tsubst (t, args, tf_error | tf_warning, NULL_TREE);
5301 if (TREE_CODE (t) == TEMPLATE_DECL)
5302 processing_template_decl--;
5303 if (TREE_CODE (r) == VAR_DECL)
5307 if (DECL_INITIALIZED_IN_CLASS_P (r))
5308 init = tsubst_expr (DECL_INITIAL (t), args,
5309 tf_error | tf_warning, NULL_TREE);
5313 finish_static_data_member_decl
5314 (r, init, /*asmspec_tree=*/NULL_TREE, /*flags=*/0);
5316 if (DECL_INITIALIZED_IN_CLASS_P (r))
5317 check_static_variable_definition (r, TREE_TYPE (r));
5319 else if (TREE_CODE (r) == FIELD_DECL)
5321 /* Determine whether R has a valid type and can be
5322 completed later. If R is invalid, then it is
5323 replaced by error_mark_node so that it will not be
5324 added to TYPE_FIELDS. */
5325 tree rtype = TREE_TYPE (r);
5326 if (can_complete_type_without_circularity (rtype))
5327 complete_type (rtype);
5329 if (!COMPLETE_TYPE_P (rtype))
5331 cxx_incomplete_type_error (r, rtype);
5332 r = error_mark_node;
5336 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
5337 such a thing will already have been added to the field
5338 list by tsubst_enum in finish_member_declaration in the
5339 CLASSTYPE_NESTED_UTDS case above. */
5340 if (!(TREE_CODE (r) == TYPE_DECL
5341 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
5342 && DECL_ARTIFICIAL (r)))
5344 set_current_access_from_decl (r);
5345 finish_member_declaration (r);
5352 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
5354 /* Build new CLASSTYPE_FRIEND_CLASSES. */
5356 tree friend_type = t;
5357 tree new_friend_type;
5359 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5360 new_friend_type = tsubst_friend_class (friend_type, args);
5361 else if (uses_template_parms (friend_type))
5362 new_friend_type = tsubst (friend_type, args,
5363 tf_error | tf_warning, NULL_TREE);
5364 else if (CLASSTYPE_USE_TEMPLATE (friend_type))
5365 new_friend_type = friend_type;
5368 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
5370 /* The call to xref_tag_from_type does injection for friend
5372 push_nested_namespace (ns);
5374 xref_tag_from_type (friend_type, NULL_TREE, 1);
5375 pop_nested_namespace (ns);
5378 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5379 /* Trick make_friend_class into realizing that the friend
5380 we're adding is a template, not an ordinary class. It's
5381 important that we use make_friend_class since it will
5382 perform some error-checking and output cross-reference
5384 ++processing_template_decl;
5386 if (new_friend_type != error_mark_node)
5387 make_friend_class (type, new_friend_type,
5388 /*complain=*/false);
5390 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5391 --processing_template_decl;
5394 /* Build new DECL_FRIENDLIST. */
5395 add_friend (type, tsubst_friend_function (t, args),
5396 /*complain=*/false);
5400 /* Set the file and line number information to whatever is given for
5401 the class itself. This puts error messages involving generated
5402 implicit functions at a predictable point, and the same point
5403 that would be used for non-template classes. */
5404 typedecl = TYPE_MAIN_DECL (type);
5405 input_location = DECL_SOURCE_LOCATION (typedecl);
5407 unreverse_member_declarations (type);
5408 finish_struct_1 (type);
5410 /* Clear this now so repo_template_used is happy. */
5411 TYPE_BEING_DEFINED (type) = 0;
5412 repo_template_used (type);
5414 /* Now that the class is complete, instantiate default arguments for
5415 any member functions. We don't do this earlier because the
5416 default arguments may reference members of the class. */
5417 if (!PRIMARY_TEMPLATE_P (template))
5418 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
5419 if (TREE_CODE (t) == FUNCTION_DECL
5420 /* Implicitly generated member functions will not have template
5421 information; they are not instantiations, but instead are
5422 created "fresh" for each instantiation. */
5423 && DECL_TEMPLATE_INFO (t))
5424 tsubst_default_arguments (t);
5427 pop_from_top_level ();
5428 pop_deferring_access_checks ();
5431 if (TYPE_CONTAINS_VPTR_P (type))
5432 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
5438 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
5444 else if (TYPE_P (t))
5445 r = tsubst (t, args, complain, in_decl);
5448 r = tsubst_expr (t, args, complain, in_decl);
5450 if (!uses_template_parms (r))
5452 /* Sometimes, one of the args was an expression involving a
5453 template constant parameter, like N - 1. Now that we've
5454 tsubst'd, we might have something like 2 - 1. This will
5455 confuse lookup_template_class, so we do constant folding
5456 here. We have to unset processing_template_decl, to fool
5457 tsubst_copy_and_build() into building an actual tree. */
5459 /* If the TREE_TYPE of ARG is not NULL_TREE, ARG is already
5460 as simple as it's going to get, and trying to reprocess
5461 the trees will break. Once tsubst_expr et al DTRT for
5462 non-dependent exprs, this code can go away, as the type
5463 will always be set. */
5466 int saved_processing_template_decl = processing_template_decl;
5467 processing_template_decl = 0;
5468 r = tsubst_copy_and_build (r, /*args=*/NULL_TREE,
5469 tf_error, /*in_decl=*/NULL_TREE,
5470 /*function_p=*/false);
5471 processing_template_decl = saved_processing_template_decl;
5479 /* Substitute ARGS into the vector or list of template arguments T. */
5482 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
5484 int len = TREE_VEC_LENGTH (t);
5485 int need_new = 0, i;
5486 tree *elts = alloca (len * sizeof (tree));
5488 for (i = 0; i < len; i++)
5490 tree orig_arg = TREE_VEC_ELT (t, i);
5493 if (TREE_CODE (orig_arg) == TREE_VEC)
5494 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
5496 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
5498 if (new_arg == error_mark_node)
5499 return error_mark_node;
5502 if (new_arg != orig_arg)
5509 t = make_tree_vec (len);
5510 for (i = 0; i < len; i++)
5511 TREE_VEC_ELT (t, i) = elts[i];
5516 /* Return the result of substituting ARGS into the template parameters
5517 given by PARMS. If there are m levels of ARGS and m + n levels of
5518 PARMS, then the result will contain n levels of PARMS. For
5519 example, if PARMS is `template <class T> template <class U>
5520 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
5521 result will be `template <int*, double, class V>'. */
5524 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
5529 for (new_parms = &r;
5530 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
5531 new_parms = &(TREE_CHAIN (*new_parms)),
5532 parms = TREE_CHAIN (parms))
5535 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
5538 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
5540 tree tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
5541 tree default_value = TREE_PURPOSE (tuple);
5542 tree parm_decl = TREE_VALUE (tuple);
5544 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
5545 default_value = tsubst_template_arg (default_value, args,
5546 complain, NULL_TREE);
5548 tuple = build_tree_list (default_value, parm_decl);
5549 TREE_VEC_ELT (new_vec, i) = tuple;
5553 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
5554 - TMPL_ARGS_DEPTH (args)),
5555 new_vec, NULL_TREE);
5561 /* Substitute the ARGS into the indicated aggregate (or enumeration)
5562 type T. If T is not an aggregate or enumeration type, it is
5563 handled as if by tsubst. IN_DECL is as for tsubst. If
5564 ENTERING_SCOPE is nonzero, T is the context for a template which
5565 we are presently tsubst'ing. Return the substituted value. */
5568 tsubst_aggr_type (tree t,
5570 tsubst_flags_t complain,
5577 switch (TREE_CODE (t))
5580 if (TYPE_PTRMEMFUNC_P (t))
5581 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
5583 /* else fall through */
5586 if (TYPE_TEMPLATE_INFO (t))
5592 /* First, determine the context for the type we are looking
5594 context = TYPE_CONTEXT (t);
5596 context = tsubst_aggr_type (context, args, complain,
5597 in_decl, /*entering_scope=*/1);
5599 /* Then, figure out what arguments are appropriate for the
5600 type we are trying to find. For example, given:
5602 template <class T> struct S;
5603 template <class T, class U> void f(T, U) { S<U> su; }
5605 and supposing that we are instantiating f<int, double>,
5606 then our ARGS will be {int, double}, but, when looking up
5607 S we only want {double}. */
5608 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
5610 if (argvec == error_mark_node)
5611 return error_mark_node;
5613 r = lookup_template_class (t, argvec, in_decl, context,
5614 entering_scope, complain);
5616 return cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
5619 /* This is not a template type, so there's nothing to do. */
5623 return tsubst (t, args, complain, in_decl);
5627 /* Substitute into the default argument ARG (a default argument for
5628 FN), which has the indicated TYPE. */
5631 tsubst_default_argument (tree fn, tree type, tree arg)
5633 /* This default argument came from a template. Instantiate the
5634 default argument here, not in tsubst. In the case of
5643 we must be careful to do name lookup in the scope of S<T>,
5644 rather than in the current class.
5646 ??? current_class_type affects a lot more than name lookup. This is
5647 very fragile. Fortunately, it will go away when we do 2-phase name
5648 binding properly. */
5650 /* FN is already the desired FUNCTION_DECL. */
5651 push_access_scope (fn);
5653 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
5654 tf_error | tf_warning, NULL_TREE);
5656 pop_access_scope (fn);
5658 /* Make sure the default argument is reasonable. */
5659 arg = check_default_argument (type, arg);
5664 /* Substitute into all the default arguments for FN. */
5667 tsubst_default_arguments (tree fn)
5672 tmpl_args = DECL_TI_ARGS (fn);
5674 /* If this function is not yet instantiated, we certainly don't need
5675 its default arguments. */
5676 if (uses_template_parms (tmpl_args))
5679 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
5681 arg = TREE_CHAIN (arg))
5682 if (TREE_PURPOSE (arg))
5683 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
5685 TREE_PURPOSE (arg));
5688 /* Substitute the ARGS into the T, which is a _DECL. TYPE is the
5689 (already computed) substitution of ARGS into TREE_TYPE (T), if
5690 appropriate. Return the result of the substitution. Issue error
5691 and warning messages under control of COMPLAIN. */
5694 tsubst_decl (tree t, tree args, tree type, tsubst_flags_t complain)
5696 location_t saved_loc;
5700 /* Set the filename and linenumber to improve error-reporting. */
5701 saved_loc = input_location;
5702 input_location = DECL_SOURCE_LOCATION (t);
5704 switch (TREE_CODE (t))
5708 /* We can get here when processing a member template function
5709 of a template class. */
5710 tree decl = DECL_TEMPLATE_RESULT (t);
5712 int is_template_template_parm = DECL_TEMPLATE_TEMPLATE_PARM_P (t);
5714 if (!is_template_template_parm)
5716 /* We might already have an instance of this template.
5717 The ARGS are for the surrounding class type, so the
5718 full args contain the tsubst'd args for the context,
5719 plus the innermost args from the template decl. */
5720 tree tmpl_args = DECL_CLASS_TEMPLATE_P (t)
5721 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
5722 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
5725 full_args = tsubst_template_args (tmpl_args, args,
5728 /* tsubst_template_args doesn't copy the vector if
5729 nothing changed. But, *something* should have
5731 my_friendly_assert (full_args != tmpl_args, 0);
5733 spec = retrieve_specialization (t, full_args);
5734 if (spec != NULL_TREE)
5741 /* Make a new template decl. It will be similar to the
5742 original, but will record the current template arguments.
5743 We also create a new function declaration, which is just
5744 like the old one, but points to this new template, rather
5745 than the old one. */
5747 my_friendly_assert (DECL_LANG_SPECIFIC (r) != 0, 0);
5748 TREE_CHAIN (r) = NULL_TREE;
5750 if (is_template_template_parm)
5752 tree new_decl = tsubst (decl, args, complain, in_decl);
5753 DECL_TEMPLATE_RESULT (r) = new_decl;
5754 TREE_TYPE (r) = TREE_TYPE (new_decl);
5759 = tsubst_aggr_type (DECL_CONTEXT (t), args,
5761 /*entering_scope=*/1);
5762 DECL_TEMPLATE_INFO (r) = build_tree_list (t, args);
5764 if (TREE_CODE (decl) == TYPE_DECL)
5766 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
5767 TREE_TYPE (r) = new_type;
5768 CLASSTYPE_TI_TEMPLATE (new_type) = r;
5769 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
5770 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
5774 tree new_decl = tsubst (decl, args, complain, in_decl);
5775 if (new_decl == error_mark_node)
5776 return error_mark_node;
5778 DECL_TEMPLATE_RESULT (r) = new_decl;
5779 DECL_TI_TEMPLATE (new_decl) = r;
5780 TREE_TYPE (r) = TREE_TYPE (new_decl);
5781 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
5784 SET_DECL_IMPLICIT_INSTANTIATION (r);
5785 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
5786 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
5788 /* The template parameters for this new template are all the
5789 template parameters for the old template, except the
5790 outermost level of parameters. */
5791 DECL_TEMPLATE_PARMS (r)
5792 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
5795 if (PRIMARY_TEMPLATE_P (t))
5796 DECL_PRIMARY_TEMPLATE (r) = r;
5798 if (TREE_CODE (decl) != TYPE_DECL)
5799 /* Record this non-type partial instantiation. */
5800 register_specialization (r, t,
5801 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)));
5808 tree argvec = NULL_TREE;
5815 /* Nobody should be tsubst'ing into non-template functions. */
5816 my_friendly_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE, 0);
5818 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
5823 /* If T is not dependent, just return it. We have to
5824 increment PROCESSING_TEMPLATE_DECL because
5825 value_dependent_expression_p assumes that nothing is
5826 dependent when PROCESSING_TEMPLATE_DECL is zero. */
5827 ++processing_template_decl;
5828 dependent_p = value_dependent_expression_p (t);
5829 --processing_template_decl;
5833 /* Calculate the most general template of which R is a
5834 specialization, and the complete set of arguments used to
5836 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
5837 argvec = tsubst_template_args (DECL_TI_ARGS
5838 (DECL_TEMPLATE_RESULT (gen_tmpl)),
5839 args, complain, in_decl);
5841 /* Check to see if we already have this specialization. */
5842 spec = retrieve_specialization (gen_tmpl, argvec);
5850 /* We can see more levels of arguments than parameters if
5851 there was a specialization of a member template, like
5854 template <class T> struct S { template <class U> void f(); }
5855 template <> template <class U> void S<int>::f(U);
5857 Here, we'll be substituting into the specialization,
5858 because that's where we can find the code we actually
5859 want to generate, but we'll have enough arguments for
5860 the most general template.
5862 We also deal with the peculiar case:
5864 template <class T> struct S {
5865 template <class U> friend void f();
5867 template <class U> void f() {}
5869 template void f<double>();
5871 Here, the ARGS for the instantiation of will be {int,
5872 double}. But, we only need as many ARGS as there are
5873 levels of template parameters in CODE_PATTERN. We are
5874 careful not to get fooled into reducing the ARGS in
5877 template <class T> struct S { template <class U> void f(U); }
5878 template <class T> template <> void S<T>::f(int) {}
5880 which we can spot because the pattern will be a
5881 specialization in this case. */
5882 args_depth = TMPL_ARGS_DEPTH (args);
5884 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
5885 if (args_depth > parms_depth
5886 && !DECL_TEMPLATE_SPECIALIZATION (t))
5887 args = get_innermost_template_args (args, parms_depth);
5891 /* This special case arises when we have something like this:
5893 template <class T> struct S {
5894 friend void f<int>(int, double);
5897 Here, the DECL_TI_TEMPLATE for the friend declaration
5898 will be an IDENTIFIER_NODE. We are being called from
5899 tsubst_friend_function, and we want only to create a
5900 new decl (R) with appropriate types so that we can call
5901 determine_specialization. */
5902 gen_tmpl = NULL_TREE;
5905 if (DECL_CLASS_SCOPE_P (t))
5907 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
5911 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
5912 complain, t, /*entering_scope=*/1);
5917 ctx = DECL_CONTEXT (t);
5919 type = tsubst (type, args, complain, in_decl);
5920 if (type == error_mark_node)
5921 return error_mark_node;
5923 /* We do NOT check for matching decls pushed separately at this
5924 point, as they may not represent instantiations of this
5925 template, and in any case are considered separate under the
5928 DECL_USE_TEMPLATE (r) = 0;
5929 TREE_TYPE (r) = type;
5930 /* Clear out the mangled name and RTL for the instantiation. */
5931 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
5932 SET_DECL_RTL (r, NULL_RTX);
5934 DECL_CONTEXT (r) = ctx;
5936 if (member && DECL_CONV_FN_P (r))
5937 /* Type-conversion operator. Reconstruct the name, in
5938 case it's the name of one of the template's parameters. */
5939 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
5941 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
5943 DECL_RESULT (r) = NULL_TREE;
5945 TREE_STATIC (r) = 0;
5946 TREE_PUBLIC (r) = TREE_PUBLIC (t);
5947 DECL_EXTERNAL (r) = 1;
5948 DECL_INTERFACE_KNOWN (r) = 0;
5949 DECL_DEFER_OUTPUT (r) = 0;
5950 TREE_CHAIN (r) = NULL_TREE;
5951 DECL_PENDING_INLINE_INFO (r) = 0;
5952 DECL_PENDING_INLINE_P (r) = 0;
5953 DECL_SAVED_TREE (r) = NULL_TREE;
5955 if (DECL_CLONED_FUNCTION (r))
5957 DECL_CLONED_FUNCTION (r) = tsubst (DECL_CLONED_FUNCTION (t),
5959 TREE_CHAIN (r) = TREE_CHAIN (DECL_CLONED_FUNCTION (r));
5960 TREE_CHAIN (DECL_CLONED_FUNCTION (r)) = r;
5963 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
5964 this in the special friend case mentioned above where
5965 GEN_TMPL is NULL. */
5968 DECL_TEMPLATE_INFO (r)
5969 = tree_cons (gen_tmpl, argvec, NULL_TREE);
5970 SET_DECL_IMPLICIT_INSTANTIATION (r);
5971 register_specialization (r, gen_tmpl, argvec);
5973 /* We're not supposed to instantiate default arguments
5974 until they are called, for a template. But, for a
5977 template <class T> void f ()
5978 { extern void g(int i = T()); }
5980 we should do the substitution when the template is
5981 instantiated. We handle the member function case in
5982 instantiate_class_template since the default arguments
5983 might refer to other members of the class. */
5985 && !PRIMARY_TEMPLATE_P (gen_tmpl)
5986 && !uses_template_parms (argvec))
5987 tsubst_default_arguments (r);
5990 /* Copy the list of befriending classes. */
5991 for (friends = &DECL_BEFRIENDING_CLASSES (r);
5993 friends = &TREE_CHAIN (*friends))
5995 *friends = copy_node (*friends);
5996 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
6001 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
6003 maybe_retrofit_in_chrg (r);
6004 if (DECL_CONSTRUCTOR_P (r))
6005 grok_ctor_properties (ctx, r);
6006 /* If this is an instantiation of a member template, clone it.
6007 If it isn't, that'll be handled by
6008 clone_constructors_and_destructors. */
6009 if (PRIMARY_TEMPLATE_P (gen_tmpl))
6010 clone_function_decl (r, /*update_method_vec_p=*/0);
6012 else if (IDENTIFIER_OPNAME_P (DECL_NAME (r)))
6013 grok_op_properties (r, DECL_FRIEND_P (r),
6014 (complain & tf_error) != 0);
6021 if (DECL_TEMPLATE_PARM_P (t))
6022 SET_DECL_TEMPLATE_PARM_P (r);
6024 TREE_TYPE (r) = type;
6025 c_apply_type_quals_to_decl (cp_type_quals (type), r);
6027 if (DECL_INITIAL (r))
6029 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
6030 DECL_INITIAL (r) = TREE_TYPE (r);
6032 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
6036 DECL_CONTEXT (r) = NULL_TREE;
6038 if (!DECL_TEMPLATE_PARM_P (r))
6039 DECL_ARG_TYPE (r) = type_passed_as (type);
6041 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
6042 complain, TREE_CHAIN (t));
6049 TREE_TYPE (r) = type;
6050 c_apply_type_quals_to_decl (cp_type_quals (type), r);
6052 /* We don't have to set DECL_CONTEXT here; it is set by
6053 finish_member_declaration. */
6054 DECL_INITIAL (r) = tsubst_expr (DECL_INITIAL (t), args,
6056 TREE_CHAIN (r) = NULL_TREE;
6057 if (VOID_TYPE_P (type))
6058 cp_error_at ("instantiation of `%D' as type `%T'", r, type);
6065 /* It is not a dependent using decl any more. */
6066 TREE_TYPE (r) = void_type_node;
6068 = tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
6069 TREE_CHAIN (r) = NULL_TREE;
6074 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM
6075 || t == TYPE_MAIN_DECL (TREE_TYPE (t)))
6077 /* If this is the canonical decl, we don't have to mess with
6078 instantiations, and often we can't (for typename, template
6079 type parms and such). Note that TYPE_NAME is not correct for
6080 the above test if we've copied the type for a typedef. */
6081 r = TYPE_NAME (type);
6089 tree argvec = NULL_TREE;
6090 tree gen_tmpl = NULL_TREE;
6092 tree tmpl = NULL_TREE;
6096 /* Assume this is a non-local variable. */
6099 if (TYPE_P (CP_DECL_CONTEXT (t)))
6100 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
6102 in_decl, /*entering_scope=*/1);
6103 else if (DECL_NAMESPACE_SCOPE_P (t))
6104 ctx = DECL_CONTEXT (t);
6107 /* Subsequent calls to pushdecl will fill this in. */
6112 /* Check to see if we already have this specialization. */
6115 tmpl = DECL_TI_TEMPLATE (t);
6116 gen_tmpl = most_general_template (tmpl);
6117 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
6118 spec = retrieve_specialization (gen_tmpl, argvec);
6121 spec = retrieve_local_specialization (t);
6130 if (TREE_CODE (r) == VAR_DECL)
6132 type = complete_type (type);
6133 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
6134 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
6136 else if (DECL_SELF_REFERENCE_P (t))
6137 SET_DECL_SELF_REFERENCE_P (r);
6138 TREE_TYPE (r) = type;
6139 c_apply_type_quals_to_decl (cp_type_quals (type), r);
6140 DECL_CONTEXT (r) = ctx;
6141 /* Clear out the mangled name and RTL for the instantiation. */
6142 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
6143 SET_DECL_RTL (r, NULL_RTX);
6145 /* Don't try to expand the initializer until someone tries to use
6146 this variable; otherwise we run into circular dependencies. */
6147 DECL_INITIAL (r) = NULL_TREE;
6148 SET_DECL_RTL (r, NULL_RTX);
6149 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
6151 /* Even if the original location is out of scope, the newly
6152 substituted one is not. */
6153 if (TREE_CODE (r) == VAR_DECL)
6155 DECL_DEAD_FOR_LOCAL (r) = 0;
6156 DECL_INITIALIZED_P (r) = 0;
6161 /* A static data member declaration is always marked
6162 external when it is declared in-class, even if an
6163 initializer is present. We mimic the non-template
6165 DECL_EXTERNAL (r) = 1;
6167 register_specialization (r, gen_tmpl, argvec);
6168 DECL_TEMPLATE_INFO (r) = tree_cons (tmpl, argvec, NULL_TREE);
6169 SET_DECL_IMPLICIT_INSTANTIATION (r);
6172 register_local_specialization (r, t);
6174 TREE_CHAIN (r) = NULL_TREE;
6175 if (TREE_CODE (r) == VAR_DECL && VOID_TYPE_P (type))
6176 cp_error_at ("instantiation of `%D' as type `%T'", r, type);
6177 /* Compute the size, alignment, etc. of R. */
6186 /* Restore the file and line information. */
6187 input_location = saved_loc;
6192 /* Substitute into the ARG_TYPES of a function type. */
6195 tsubst_arg_types (tree arg_types,
6197 tsubst_flags_t complain,
6200 tree remaining_arg_types;
6203 if (!arg_types || arg_types == void_list_node)
6206 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
6207 args, complain, in_decl);
6208 if (remaining_arg_types == error_mark_node)
6209 return error_mark_node;
6211 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
6212 if (type == error_mark_node)
6213 return error_mark_node;
6214 if (VOID_TYPE_P (type))
6216 if (complain & tf_error)
6218 error ("invalid parameter type `%T'", type);
6220 cp_error_at ("in declaration `%D'", in_decl);
6222 return error_mark_node;
6225 /* Do array-to-pointer, function-to-pointer conversion, and ignore
6226 top-level qualifiers as required. */
6227 type = TYPE_MAIN_VARIANT (type_decays_to (type));
6229 /* Note that we do not substitute into default arguments here. The
6230 standard mandates that they be instantiated only when needed,
6231 which is done in build_over_call. */
6232 return hash_tree_cons (TREE_PURPOSE (arg_types), type,
6233 remaining_arg_types);
6237 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
6238 *not* handle the exception-specification for FNTYPE, because the
6239 initial substitution of explicitly provided template parameters
6240 during argument deduction forbids substitution into the
6241 exception-specification:
6245 All references in the function type of the function template to the
6246 corresponding template parameters are replaced by the specified tem-
6247 plate argument values. If a substitution in a template parameter or
6248 in the function type of the function template results in an invalid
6249 type, type deduction fails. [Note: The equivalent substitution in
6250 exception specifications is done only when the function is instanti-
6251 ated, at which point a program is ill-formed if the substitution
6252 results in an invalid type.] */
6255 tsubst_function_type (tree t,
6257 tsubst_flags_t complain,
6264 /* The TYPE_CONTEXT is not used for function/method types. */
6265 my_friendly_assert (TYPE_CONTEXT (t) == NULL_TREE, 0);
6267 /* Substitute the return type. */
6268 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
6269 if (return_type == error_mark_node)
6270 return error_mark_node;
6272 /* Substitute the argument types. */
6273 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
6275 if (arg_types == error_mark_node)
6276 return error_mark_node;
6278 /* Construct a new type node and return it. */
6279 if (TREE_CODE (t) == FUNCTION_TYPE)
6280 fntype = build_function_type (return_type, arg_types);
6283 tree r = TREE_TYPE (TREE_VALUE (arg_types));
6284 if (! IS_AGGR_TYPE (r))
6288 Type deduction may fail for any of the following
6291 -- Attempting to create "pointer to member of T" when T
6292 is not a class type. */
6293 if (complain & tf_error)
6294 error ("creating pointer to member function of non-class type `%T'",
6296 return error_mark_node;
6299 fntype = build_method_type_directly (r, return_type,
6300 TREE_CHAIN (arg_types));
6302 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
6303 fntype = build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
6308 /* Substitute into the PARMS of a call-declarator. */
6311 tsubst_call_declarator_parms (tree parms,
6313 tsubst_flags_t complain,
6320 if (!parms || parms == void_list_node)
6323 new_parms = tsubst_call_declarator_parms (TREE_CHAIN (parms),
6324 args, complain, in_decl);
6326 /* Figure out the type of this parameter. */
6327 type = tsubst (TREE_VALUE (parms), args, complain, in_decl);
6329 /* Figure out the default argument as well. Note that we use
6330 tsubst_expr since the default argument is really an expression. */
6331 defarg = tsubst_expr (TREE_PURPOSE (parms), args, complain, in_decl);
6333 /* Chain this parameter on to the front of those we have already
6334 processed. We don't use hash_tree_cons because that function
6335 doesn't check TREE_PARMLIST. */
6336 new_parms = tree_cons (defarg, type, new_parms);
6338 /* And note that these are parameters. */
6339 TREE_PARMLIST (new_parms) = 1;
6344 /* Take the tree structure T and replace template parameters used
6345 therein with the argument vector ARGS. IN_DECL is an associated
6346 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
6347 Issue error and warning messages under control of COMPLAIN. Note
6348 that we must be relatively non-tolerant of extensions here, in
6349 order to preserve conformance; if we allow substitutions that
6350 should not be allowed, we may allow argument deductions that should
6351 not succeed, and therefore report ambiguous overload situations
6352 where there are none. In theory, we could allow the substitution,
6353 but indicate that it should have failed, and allow our caller to
6354 make sure that the right thing happens, but we don't try to do this
6357 This function is used for dealing with types, decls and the like;
6358 for expressions, use tsubst_expr or tsubst_copy. */
6361 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
6365 if (t == NULL_TREE || t == error_mark_node
6366 || t == integer_type_node
6367 || t == void_type_node
6368 || t == char_type_node
6369 || TREE_CODE (t) == NAMESPACE_DECL)
6372 if (TREE_CODE (t) == IDENTIFIER_NODE)
6373 type = IDENTIFIER_TYPE_VALUE (t);
6375 type = TREE_TYPE (t);
6377 my_friendly_assert (type != unknown_type_node, 20030716);
6379 if (type && TREE_CODE (t) != FUNCTION_DECL
6380 && TREE_CODE (t) != TYPENAME_TYPE
6381 && TREE_CODE (t) != TEMPLATE_DECL
6382 && TREE_CODE (t) != IDENTIFIER_NODE
6383 && TREE_CODE (t) != FUNCTION_TYPE
6384 && TREE_CODE (t) != METHOD_TYPE)
6385 type = tsubst (type, args, complain, in_decl);
6386 if (type == error_mark_node)
6387 return error_mark_node;
6390 return tsubst_decl (t, args, type, complain);
6392 switch (TREE_CODE (t))
6397 return tsubst_aggr_type (t, args, complain, in_decl,
6398 /*entering_scope=*/0);
6401 case IDENTIFIER_NODE:
6413 if (t == integer_type_node)
6416 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
6417 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
6421 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
6423 /* The array dimension behaves like a non-type template arg,
6424 in that we want to fold it as much as possible. */
6425 max = tsubst_template_arg (omax, args, complain, in_decl);
6426 if (!processing_template_decl)
6427 max = decl_constant_value (max);
6429 if (processing_template_decl
6430 /* When providing explicit arguments to a template
6431 function, but leaving some arguments for subsequent
6432 deduction, MAX may be template-dependent even if we're
6433 not PROCESSING_TEMPLATE_DECL. We still need to check for
6434 template parms, though; MAX won't be an INTEGER_CST for
6435 dynamic arrays, either. */
6436 || (TREE_CODE (max) != INTEGER_CST
6437 && uses_template_parms (max)))
6439 tree itype = make_node (INTEGER_TYPE);
6440 TYPE_MIN_VALUE (itype) = size_zero_node;
6441 TYPE_MAX_VALUE (itype) = build_min (MINUS_EXPR, sizetype, max,
6446 if (integer_zerop (omax))
6448 /* Still allow an explicit array of size zero. */
6450 pedwarn ("creating array with size zero");
6452 else if (integer_zerop (max)
6453 || (TREE_CODE (max) == INTEGER_CST
6454 && INT_CST_LT (max, integer_zero_node)))
6458 Type deduction may fail for any of the following
6461 Attempting to create an array with a size that is
6462 zero or negative. */
6463 if (complain & tf_error)
6464 error ("creating array with size zero (`%E')", max);
6466 return error_mark_node;
6469 return compute_array_index_type (NULL_TREE, max);
6472 case TEMPLATE_TYPE_PARM:
6473 case TEMPLATE_TEMPLATE_PARM:
6474 case BOUND_TEMPLATE_TEMPLATE_PARM:
6475 case TEMPLATE_PARM_INDEX:
6483 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM
6484 || TREE_CODE (t) == TEMPLATE_TEMPLATE_PARM
6485 || TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
6487 idx = TEMPLATE_TYPE_IDX (t);
6488 level = TEMPLATE_TYPE_LEVEL (t);
6492 idx = TEMPLATE_PARM_IDX (t);
6493 level = TEMPLATE_PARM_LEVEL (t);
6496 if (TREE_VEC_LENGTH (args) > 0)
6498 tree arg = NULL_TREE;
6500 levels = TMPL_ARGS_DEPTH (args);
6501 if (level <= levels)
6502 arg = TMPL_ARG (args, level, idx);
6504 if (arg == error_mark_node)
6505 return error_mark_node;
6506 else if (arg != NULL_TREE)
6508 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
6510 my_friendly_assert (TYPE_P (arg), 0);
6511 return cp_build_qualified_type_real
6512 (arg, cp_type_quals (arg) | cp_type_quals (t),
6513 complain | tf_ignore_bad_quals);
6515 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
6517 /* We are processing a type constructed from
6518 a template template parameter */
6519 tree argvec = tsubst (TYPE_TI_ARGS (t),
6520 args, complain, in_decl);
6521 if (argvec == error_mark_node)
6522 return error_mark_node;
6524 /* We can get a TEMPLATE_TEMPLATE_PARM here when
6525 we are resolving nested-types in the signature of
6526 a member function templates.
6527 Otherwise ARG is a TEMPLATE_DECL and is the real
6528 template to be instantiated. */
6529 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
6530 arg = TYPE_NAME (arg);
6532 r = lookup_template_class (arg,
6535 /*entering_scope=*/0,
6537 return cp_build_qualified_type_real
6538 (r, TYPE_QUALS (t), complain);
6541 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
6549 /* This can happen during the attempted tsubst'ing in
6550 unify. This means that we don't yet have any information
6551 about the template parameter in question. */
6554 /* If we get here, we must have been looking at a parm for a
6555 more deeply nested template. Make a new version of this
6556 template parameter, but with a lower level. */
6557 switch (TREE_CODE (t))
6559 case TEMPLATE_TYPE_PARM:
6560 case TEMPLATE_TEMPLATE_PARM:
6561 case BOUND_TEMPLATE_TEMPLATE_PARM:
6562 if (cp_type_quals (t))
6564 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
6565 r = cp_build_qualified_type_real
6566 (r, cp_type_quals (t),
6567 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
6568 ? tf_ignore_bad_quals : 0));
6573 TEMPLATE_TYPE_PARM_INDEX (r)
6574 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
6576 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
6577 TYPE_MAIN_VARIANT (r) = r;
6578 TYPE_POINTER_TO (r) = NULL_TREE;
6579 TYPE_REFERENCE_TO (r) = NULL_TREE;
6581 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
6583 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
6585 if (argvec == error_mark_node)
6586 return error_mark_node;
6588 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
6589 = tree_cons (TYPE_TI_TEMPLATE (t), argvec, NULL_TREE);
6594 case TEMPLATE_PARM_INDEX:
6595 r = reduce_template_parm_level (t, type, levels);
6607 tree purpose, value, chain, result;
6609 if (t == void_list_node)
6612 purpose = TREE_PURPOSE (t);
6615 purpose = tsubst (purpose, args, complain, in_decl);
6616 if (purpose == error_mark_node)
6617 return error_mark_node;
6619 value = TREE_VALUE (t);
6622 value = tsubst (value, args, complain, in_decl);
6623 if (value == error_mark_node)
6624 return error_mark_node;
6626 chain = TREE_CHAIN (t);
6627 if (chain && chain != void_type_node)
6629 chain = tsubst (chain, args, complain, in_decl);
6630 if (chain == error_mark_node)
6631 return error_mark_node;
6633 if (purpose == TREE_PURPOSE (t)
6634 && value == TREE_VALUE (t)
6635 && chain == TREE_CHAIN (t))
6637 if (TREE_PARMLIST (t))
6639 result = tree_cons (purpose, value, chain);
6640 TREE_PARMLIST (result) = 1;
6643 result = hash_tree_cons (purpose, value, chain);
6647 if (type != NULL_TREE)
6649 /* A binfo node. We always need to make a copy, of the node
6650 itself and of its BINFO_BASETYPES. */
6654 /* Make sure type isn't a typedef copy. */
6655 type = BINFO_TYPE (TYPE_BINFO (type));
6657 TREE_TYPE (t) = complete_type (type);
6658 if (IS_AGGR_TYPE (type))
6660 BINFO_VTABLE (t) = TYPE_BINFO_VTABLE (type);
6661 BINFO_VIRTUALS (t) = TYPE_BINFO_VIRTUALS (type);
6662 if (TYPE_BINFO_BASETYPES (type) != NULL_TREE)
6663 BINFO_BASETYPES (t) = copy_node (TYPE_BINFO_BASETYPES (type));
6668 /* Otherwise, a vector of template arguments. */
6669 return tsubst_template_args (t, args, complain, in_decl);
6672 case REFERENCE_TYPE:
6674 enum tree_code code;
6676 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
6679 code = TREE_CODE (t);
6684 Type deduction may fail for any of the following
6687 -- Attempting to create a pointer to reference type.
6688 -- Attempting to create a reference to a reference type or
6689 a reference to void. */
6690 if (TREE_CODE (type) == REFERENCE_TYPE
6691 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
6693 static location_t last_loc;
6695 /* We keep track of the last time we issued this error
6696 message to avoid spewing a ton of messages during a
6697 single bad template instantiation. */
6698 if (complain & tf_error
6699 && (last_loc.line != input_line
6700 || last_loc.file != input_filename))
6702 if (TREE_CODE (type) == VOID_TYPE)
6703 error ("forming reference to void");
6705 error ("forming %s to reference type `%T'",
6706 (code == POINTER_TYPE) ? "pointer" : "reference",
6708 last_loc = input_location;
6711 return error_mark_node;
6713 else if (code == POINTER_TYPE)
6715 r = build_pointer_type (type);
6716 if (TREE_CODE (type) == METHOD_TYPE)
6717 r = build_ptrmemfunc_type (r);
6720 r = build_reference_type (type);
6721 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
6723 if (r != error_mark_node)
6724 /* Will this ever be needed for TYPE_..._TO values? */
6731 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
6732 if (r == error_mark_node || !IS_AGGR_TYPE (r))
6736 Type deduction may fail for any of the following
6739 -- Attempting to create "pointer to member of T" when T
6740 is not a class type. */
6741 if (complain & tf_error)
6742 error ("creating pointer to member of non-class type `%T'", r);
6743 return error_mark_node;
6745 if (TREE_CODE (type) == REFERENCE_TYPE)
6747 if (complain & tf_error)
6748 error ("creating pointer to member reference type `%T'", type);
6750 return error_mark_node;
6752 my_friendly_assert (TREE_CODE (type) != METHOD_TYPE, 20011231);
6753 if (TREE_CODE (type) == FUNCTION_TYPE)
6755 /* This is really a method type. The cv qualifiers of the
6756 this pointer should _not_ be determined by the cv
6757 qualifiers of the class type. They should be held
6758 somewhere in the FUNCTION_TYPE, but we don't do that at
6759 the moment. Consider
6760 typedef void (Func) () const;
6762 template <typename T1> void Foo (Func T1::*);
6767 method_type = build_method_type_directly (TYPE_MAIN_VARIANT (r),
6769 TYPE_ARG_TYPES (type));
6770 return build_ptrmemfunc_type (build_pointer_type (method_type));
6773 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
6783 fntype = tsubst_function_type (t, args, complain, in_decl);
6784 if (fntype == error_mark_node)
6785 return error_mark_node;
6787 /* Substitute the exception specification. */
6788 raises = TYPE_RAISES_EXCEPTIONS (t);
6791 tree list = NULL_TREE;
6793 if (! TREE_VALUE (raises))
6796 for (; raises != NULL_TREE; raises = TREE_CHAIN (raises))
6798 tree spec = TREE_VALUE (raises);
6800 spec = tsubst (spec, args, complain, in_decl);
6801 if (spec == error_mark_node)
6803 list = add_exception_specifier (list, spec, complain);
6805 fntype = build_exception_variant (fntype, list);
6811 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
6812 if (domain == error_mark_node)
6813 return error_mark_node;
6815 /* As an optimization, we avoid regenerating the array type if
6816 it will obviously be the same as T. */
6817 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
6820 /* These checks should match the ones in grokdeclarator.
6824 The deduction may fail for any of the following reasons:
6826 -- Attempting to create an array with an element type that
6827 is void, a function type, or a reference type. */
6828 if (TREE_CODE (type) == VOID_TYPE
6829 || TREE_CODE (type) == FUNCTION_TYPE
6830 || TREE_CODE (type) == REFERENCE_TYPE)
6832 if (complain & tf_error)
6833 error ("creating array of `%T'", type);
6834 return error_mark_node;
6837 r = build_cplus_array_type (type, domain);
6844 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
6845 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
6847 if (e1 == error_mark_node || e2 == error_mark_node)
6848 return error_mark_node;
6850 return fold (build (TREE_CODE (t), TREE_TYPE (t), e1, e2));
6856 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
6857 if (e == error_mark_node)
6858 return error_mark_node;
6860 return fold (build (TREE_CODE (t), TREE_TYPE (t), e));
6865 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
6866 in_decl, /*entering_scope=*/1);
6867 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
6870 if (ctx == error_mark_node || f == error_mark_node)
6871 return error_mark_node;
6873 if (!IS_AGGR_TYPE (ctx))
6875 if (complain & tf_error)
6876 error ("`%T' is not a class, struct, or union type",
6878 return error_mark_node;
6880 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
6882 /* Normally, make_typename_type does not require that the CTX
6883 have complete type in order to allow things like:
6885 template <class T> struct S { typename S<T>::X Y; };
6887 But, such constructs have already been resolved by this
6888 point, so here CTX really should have complete type, unless
6889 it's a partial instantiation. */
6890 ctx = complete_type (ctx);
6891 if (!COMPLETE_TYPE_P (ctx))
6893 if (complain & tf_error)
6894 cxx_incomplete_type_error (NULL_TREE, ctx);
6895 return error_mark_node;
6899 f = make_typename_type (ctx, f,
6900 (complain & tf_error) | tf_keep_type_decl);
6901 if (f == error_mark_node)
6903 if (TREE_CODE (f) == TYPE_DECL)
6905 complain |= tf_ignore_bad_quals;
6909 return cp_build_qualified_type_real
6910 (f, cp_type_quals (f) | cp_type_quals (t), complain);
6913 case UNBOUND_CLASS_TEMPLATE:
6915 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
6916 in_decl, /*entering_scope=*/1);
6917 tree name = TYPE_IDENTIFIER (t);
6919 if (ctx == error_mark_node || name == error_mark_node)
6920 return error_mark_node;
6922 return make_unbound_class_template (ctx, name, complain);
6927 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
6928 if (e == error_mark_node)
6929 return error_mark_node;
6930 return make_pointer_declarator (type, e);
6935 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
6936 if (e == error_mark_node)
6937 return error_mark_node;
6938 return make_reference_declarator (type, e);
6943 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
6944 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl);
6945 if (e1 == error_mark_node || e2 == error_mark_node)
6946 return error_mark_node;
6948 return build_nt (ARRAY_REF, e1, e2, tsubst_expr);
6953 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
6954 tree e2 = (tsubst_call_declarator_parms
6955 (CALL_DECLARATOR_PARMS (t), args, complain, in_decl));
6956 tree e3 = tsubst (CALL_DECLARATOR_EXCEPTION_SPEC (t), args,
6959 if (e1 == error_mark_node || e2 == error_mark_node
6960 || e3 == error_mark_node)
6961 return error_mark_node;
6963 return make_call_declarator (e1, e2, CALL_DECLARATOR_QUALS (t), e3);
6968 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
6969 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
6970 if (e1 == error_mark_node || e2 == error_mark_node)
6971 return error_mark_node;
6973 return build_nt (TREE_CODE (t), e1, e2);
6978 tree e1 = tsubst_expr (TYPE_FIELDS (t), args, complain, in_decl);
6979 if (e1 == error_mark_node)
6980 return error_mark_node;
6982 return cp_build_qualified_type_real (TREE_TYPE (e1),
6984 | cp_type_quals (TREE_TYPE (e1)),
6989 sorry ("use of `%s' in template",
6990 tree_code_name [(int) TREE_CODE (t)]);
6991 return error_mark_node;
6995 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
6996 type of the expression on the left-hand side of the "." or "->"
7000 tsubst_baselink (tree baselink, tree object_type,
7001 tree args, tsubst_flags_t complain, tree in_decl)
7004 tree qualifying_scope;
7006 tree template_args = 0;
7007 bool template_id_p = false;
7009 /* A baselink indicates a function from a base class. The
7010 BASELINK_ACCESS_BINFO and BASELINK_BINFO are going to have
7011 non-dependent types; otherwise, the lookup could not have
7012 succeeded. However, they may indicate bases of the template
7013 class, rather than the instantiated class.
7015 In addition, lookups that were not ambiguous before may be
7016 ambiguous now. Therefore, we perform the lookup again. */
7017 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
7018 fns = BASELINK_FUNCTIONS (baselink);
7019 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
7021 template_id_p = true;
7022 template_args = TREE_OPERAND (fns, 1);
7023 fns = TREE_OPERAND (fns, 0);
7025 template_args = tsubst_template_args (template_args, args,
7028 name = DECL_NAME (get_first_fn (fns));
7029 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
7030 if (BASELINK_P (baselink) && template_id_p)
7031 BASELINK_FUNCTIONS (baselink)
7032 = build_nt (TEMPLATE_ID_EXPR,
7033 BASELINK_FUNCTIONS (baselink),
7036 object_type = current_class_type;
7037 return adjust_result_of_qualified_name_lookup (baselink,
7042 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
7043 true if the qualified-id will be a postfix-expression in-and-of
7044 itself; false if more of the postfix-expression follows the
7045 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
7049 tsubst_qualified_id (tree qualified_id, tree args,
7050 tsubst_flags_t complain, tree in_decl,
7051 bool done, bool address_p)
7059 my_friendly_assert (TREE_CODE (qualified_id) == SCOPE_REF, 20030706);
7061 /* Figure out what name to look up. */
7062 name = TREE_OPERAND (qualified_id, 1);
7063 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
7066 template_args = TREE_OPERAND (name, 1);
7068 template_args = tsubst_template_args (template_args, args,
7070 name = TREE_OPERAND (name, 0);
7074 is_template = false;
7075 template_args = NULL_TREE;
7078 /* Substitute into the qualifying scope. When there are no ARGS, we
7079 are just trying to simplify a non-dependent expression. In that
7080 case the qualifying scope may be dependent, and, in any case,
7081 substituting will not help. */
7082 scope = TREE_OPERAND (qualified_id, 0);
7085 scope = tsubst (scope, args, complain, in_decl);
7086 expr = tsubst_copy (name, args, complain, in_decl);
7091 my_friendly_assert (!dependent_type_p (scope), 20030729);
7093 if (!BASELINK_P (name) && !DECL_P (expr))
7094 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
7097 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
7100 /* Remember that there was a reference to this entity. */
7104 if (!args && TREE_CODE (expr) == VAR_DECL)
7105 expr = DECL_INITIAL (expr);
7109 expr = lookup_template_function (expr, template_args);
7111 if (expr == error_mark_node && complain & tf_error)
7112 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1));
7113 else if (TYPE_P (scope))
7115 expr = (adjust_result_of_qualified_name_lookup
7116 (expr, scope, current_class_type));
7117 expr = finish_qualified_id_expr (scope, expr, done, address_p);
7123 /* Like tsubst, but deals with expressions. This function just replaces
7124 template parms; to finish processing the resultant expression, use
7128 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7130 enum tree_code code;
7133 if (t == NULL_TREE || t == error_mark_node)
7136 code = TREE_CODE (t);
7141 r = retrieve_local_specialization (t);
7142 my_friendly_assert (r != NULL, 20020903);
7150 if (DECL_TEMPLATE_PARM_P (t))
7151 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
7152 /* There is no need to substitute into namespace-scope
7154 if (DECL_NAMESPACE_SCOPE_P (t))
7157 /* Unfortunately, we cannot just call lookup_name here.
7160 template <int I> int f() {
7162 struct S { void g() { E e = a; } };
7165 When we instantiate f<7>::S::g(), say, lookup_name is not
7166 clever enough to find f<7>::a. */
7168 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
7169 /*entering_scope=*/0);
7171 for (v = TYPE_VALUES (enum_type);
7174 if (TREE_PURPOSE (v) == DECL_NAME (t))
7175 return TREE_VALUE (v);
7177 /* We didn't find the name. That should never happen; if
7178 name-lookup found it during preliminary parsing, we
7179 should find it again here during instantiation. */
7185 if (DECL_CONTEXT (t))
7189 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
7190 /*entering_scope=*/1);
7191 if (ctx != DECL_CONTEXT (t))
7192 return lookup_field (ctx, DECL_NAME (t), 0, false);
7198 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
7199 || local_variable_p (t))
7200 t = tsubst (t, args, complain, in_decl);
7205 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
7208 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
7209 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
7210 args, complain, in_decl);
7211 else if (is_member_template (t))
7212 return tsubst (t, args, complain, in_decl);
7213 else if (DECL_CLASS_SCOPE_P (t)
7214 && uses_template_parms (DECL_CONTEXT (t)))
7216 /* Template template argument like the following example need
7219 template <template <class> class TT> struct C {};
7220 template <class T> struct D {
7221 template <class U> struct E {};
7226 We are processing the template argument `E' in #1 for
7227 the template instantiation #2. Originally, `E' is a
7228 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
7229 have to substitute this with one having context `D<int>'. */
7231 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
7232 return lookup_field (context, DECL_NAME(t), 0, false);
7235 /* Ordinary template template argument. */
7239 case REINTERPRET_CAST_EXPR:
7240 case CONST_CAST_EXPR:
7241 case STATIC_CAST_EXPR:
7242 case DYNAMIC_CAST_EXPR:
7245 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
7246 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
7250 case TRUTH_NOT_EXPR:
7253 case CONVERT_EXPR: /* Unary + */
7262 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
7263 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
7270 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
7271 name = TREE_OPERAND (t, 1);
7272 if (TREE_CODE (name) == BIT_NOT_EXPR)
7274 name = tsubst_copy (TREE_OPERAND (name, 0), args,
7276 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
7278 else if (TREE_CODE (name) == SCOPE_REF
7279 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
7281 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
7283 name = TREE_OPERAND (name, 1);
7284 name = tsubst_copy (TREE_OPERAND (name, 0), args,
7286 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
7287 name = build_nt (SCOPE_REF, base, name);
7289 else if (TREE_CODE (name) == BASELINK)
7290 name = tsubst_baselink (name,
7291 non_reference (TREE_TYPE (object)),
7295 name = tsubst_copy (name, args, complain, in_decl);
7296 return build_nt (COMPONENT_REF, object, name);
7302 case TRUNC_DIV_EXPR:
7304 case FLOOR_DIV_EXPR:
7305 case ROUND_DIV_EXPR:
7306 case EXACT_DIV_EXPR:
7310 case TRUNC_MOD_EXPR:
7311 case FLOOR_MOD_EXPR:
7312 case TRUTH_ANDIF_EXPR:
7313 case TRUTH_ORIF_EXPR:
7314 case TRUTH_AND_EXPR:
7333 case PREDECREMENT_EXPR:
7334 case PREINCREMENT_EXPR:
7335 case POSTDECREMENT_EXPR:
7336 case POSTINCREMENT_EXPR:
7338 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
7339 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
7342 return build_nt (code,
7343 tsubst_copy (TREE_OPERAND (t, 0), args,
7345 tsubst_copy (TREE_OPERAND (t, 1), args, complain,
7350 /* This processing should really occur in tsubst_expr. However,
7351 tsubst_expr does not recurse into expressions, since it
7352 assumes that there aren't any statements inside them. So, we
7353 need to expand the STMT_EXPR here. */
7354 if (!processing_template_decl)
7356 tree stmt_expr = begin_stmt_expr ();
7358 tsubst_expr (STMT_EXPR_STMT (t), args,
7359 complain | tf_stmt_expr_cmpd, in_decl);
7360 return finish_stmt_expr (stmt_expr, false);
7367 case PSEUDO_DTOR_EXPR:
7370 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
7371 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
7372 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
7379 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
7380 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
7381 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
7382 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
7389 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
7390 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
7391 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
7392 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
7396 case TEMPLATE_ID_EXPR:
7398 /* Substituted template arguments */
7399 tree fn = TREE_OPERAND (t, 0);
7400 tree targs = TREE_OPERAND (t, 1);
7402 fn = tsubst_copy (fn, args, complain, in_decl);
7404 targs = tsubst_template_args (targs, args, complain, in_decl);
7406 return lookup_template_function (fn, targs);
7411 tree purpose, value, chain;
7413 if (t == void_list_node)
7416 purpose = TREE_PURPOSE (t);
7418 purpose = tsubst_copy (purpose, args, complain, in_decl);
7419 value = TREE_VALUE (t);
7421 value = tsubst_copy (value, args, complain, in_decl);
7422 chain = TREE_CHAIN (t);
7423 if (chain && chain != void_type_node)
7424 chain = tsubst_copy (chain, args, complain, in_decl);
7425 if (purpose == TREE_PURPOSE (t)
7426 && value == TREE_VALUE (t)
7427 && chain == TREE_CHAIN (t))
7429 return tree_cons (purpose, value, chain);
7436 case TEMPLATE_TYPE_PARM:
7437 case TEMPLATE_TEMPLATE_PARM:
7438 case BOUND_TEMPLATE_TEMPLATE_PARM:
7439 case TEMPLATE_PARM_INDEX:
7441 case REFERENCE_TYPE:
7447 case UNBOUND_CLASS_TEMPLATE:
7450 return tsubst (t, args, complain, in_decl);
7452 case IDENTIFIER_NODE:
7453 if (IDENTIFIER_TYPENAME_P (t))
7455 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
7456 return mangle_conv_op_name_for_type (new_type);
7463 r = build_constructor
7464 (tsubst (TREE_TYPE (t), args, complain, in_decl),
7465 tsubst_copy (CONSTRUCTOR_ELTS (t), args, complain, in_decl));
7466 TREE_HAS_CONSTRUCTOR (r) = TREE_HAS_CONSTRUCTOR (t);
7471 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
7473 tsubst (TREE_TYPE (t), args, complain, in_decl));
7480 /* Like tsubst_copy for expressions, etc. but also does semantic
7484 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7487 tsubst_flags_t stmt_expr
7488 = complain & (tf_stmt_expr_cmpd | tf_stmt_expr_body);
7490 complain ^= stmt_expr;
7491 if (t == NULL_TREE || t == error_mark_node)
7494 if (processing_template_decl)
7495 return tsubst_copy (t, args, complain, in_decl);
7497 if (!STATEMENT_CODE_P (TREE_CODE (t)))
7498 return tsubst_copy_and_build (t, args, complain, in_decl,
7499 /*function_p=*/false);
7501 switch (TREE_CODE (t))
7503 case CTOR_INITIALIZER:
7505 finish_mem_initializers (tsubst_initializer_list
7506 (TREE_OPERAND (t, 0), args));
7511 finish_return_stmt (tsubst_expr (RETURN_STMT_EXPR (t),
7512 args, complain, in_decl));
7521 r = tsubst_expr (EXPR_STMT_EXPR (t), args, complain, in_decl);
7522 if (stmt_expr & tf_stmt_expr_body && !TREE_CHAIN (t))
7523 finish_stmt_expr_expr (r);
7525 finish_expr_stmt (r);
7531 do_using_directive (tsubst_expr (USING_STMT_NAMESPACE (t),
7532 args, complain, in_decl));
7541 decl = DECL_STMT_DECL (t);
7542 if (TREE_CODE (decl) == LABEL_DECL)
7543 finish_label_decl (DECL_NAME (decl));
7544 else if (TREE_CODE (decl) == USING_DECL)
7546 tree scope = DECL_INITIAL (decl);
7547 tree name = DECL_NAME (decl);
7550 scope = tsubst_expr (scope, args, complain, in_decl);
7551 decl = lookup_qualified_name (scope, name,
7552 /*is_type_p=*/0, /*complain=*/false);
7553 if (decl == error_mark_node)
7554 qualified_name_lookup_error (scope, name);
7556 do_local_using_decl (decl);
7560 init = DECL_INITIAL (decl);
7561 decl = tsubst (decl, args, complain, in_decl);
7562 if (decl != error_mark_node)
7565 DECL_INITIAL (decl) = error_mark_node;
7566 /* By marking the declaration as instantiated, we avoid
7567 trying to instantiate it. Since instantiate_decl can't
7568 handle local variables, and since we've already done
7569 all that needs to be done, that's the right thing to
7571 if (TREE_CODE (decl) == VAR_DECL)
7572 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
7573 if (TREE_CODE (decl) == VAR_DECL
7574 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
7575 /* Anonymous aggregates are a special case. */
7576 finish_anon_union (decl);
7579 maybe_push_decl (decl);
7580 if (TREE_CODE (decl) == VAR_DECL
7581 && DECL_PRETTY_FUNCTION_P (decl))
7583 /* For __PRETTY_FUNCTION__ we have to adjust the
7585 const char *const name
7586 = cxx_printable_name (current_function_decl, 2);
7587 init = cp_fname_init (name);
7588 TREE_TYPE (decl) = TREE_TYPE (init);
7591 init = tsubst_expr (init, args, complain, in_decl);
7592 cp_finish_decl (decl, init, NULL_TREE, 0);
7597 /* A DECL_STMT can also be used as an expression, in the condition
7598 clause of an if/for/while construct. If we aren't followed by
7599 another statement, return our decl. */
7600 if (TREE_CHAIN (t) == NULL_TREE)
7609 stmt = begin_for_stmt ();
7610 tsubst_expr (FOR_INIT_STMT (t), args, complain, in_decl);
7611 finish_for_init_stmt (stmt);
7612 finish_for_cond (tsubst_expr (FOR_COND (t),
7613 args, complain, in_decl),
7615 tmp = tsubst_expr (FOR_EXPR (t), args, complain, in_decl);
7616 finish_for_expr (tmp, stmt);
7617 tsubst_expr (FOR_BODY (t), args, complain, in_decl);
7618 finish_for_stmt (stmt);
7625 stmt = begin_while_stmt ();
7626 finish_while_stmt_cond (tsubst_expr (WHILE_COND (t),
7627 args, complain, in_decl),
7629 tsubst_expr (WHILE_BODY (t), args, complain, in_decl);
7630 finish_while_stmt (stmt);
7637 stmt = begin_do_stmt ();
7638 tsubst_expr (DO_BODY (t), args, complain, in_decl);
7639 finish_do_body (stmt);
7640 finish_do_stmt (tsubst_expr (DO_COND (t),
7641 args, complain, in_decl),
7649 stmt = begin_if_stmt ();
7650 finish_if_stmt_cond (tsubst_expr (IF_COND (t),
7651 args, complain, in_decl),
7654 if (tmp = THEN_CLAUSE (t), tmp)
7656 tsubst_expr (tmp, args, complain, in_decl);
7657 finish_then_clause (stmt);
7660 if (tmp = ELSE_CLAUSE (t), tmp)
7662 begin_else_clause ();
7663 tsubst_expr (tmp, args, complain, in_decl);
7664 finish_else_clause (stmt);
7674 if (COMPOUND_STMT_BODY_BLOCK (t))
7675 stmt = begin_function_body ();
7677 stmt = begin_compound_stmt (COMPOUND_STMT_NO_SCOPE (t));
7679 tsubst_expr (COMPOUND_BODY (t), args,
7680 complain | ((stmt_expr & tf_stmt_expr_cmpd) << 1),
7683 if (COMPOUND_STMT_BODY_BLOCK (t))
7684 finish_function_body (stmt);
7686 finish_compound_stmt (stmt);
7692 finish_break_stmt ();
7697 finish_continue_stmt ();
7705 stmt = begin_switch_stmt ();
7706 val = tsubst_expr (SWITCH_COND (t), args, complain, in_decl);
7707 finish_switch_cond (val, stmt);
7708 tsubst_expr (SWITCH_BODY (t), args, complain, in_decl);
7709 finish_switch_stmt (stmt);
7715 finish_case_label (tsubst_expr (CASE_LOW (t), args, complain, in_decl),
7716 tsubst_expr (CASE_HIGH (t), args, complain,
7721 input_line = STMT_LINENO (t);
7722 finish_label_stmt (DECL_NAME (LABEL_STMT_LABEL (t)));
7726 input_filename = FILE_STMT_FILENAME (t);
7727 add_stmt (build_nt (FILE_STMT, FILE_STMT_FILENAME_NODE (t)));
7732 tmp = GOTO_DESTINATION (t);
7733 if (TREE_CODE (tmp) != LABEL_DECL)
7734 /* Computed goto's must be tsubst'd into. On the other hand,
7735 non-computed gotos must not be; the identifier in question
7736 will have no binding. */
7737 tmp = tsubst_expr (tmp, args, complain, in_decl);
7739 tmp = DECL_NAME (tmp);
7740 finish_goto_stmt (tmp);
7745 tmp = finish_asm_stmt
7747 tsubst_expr (ASM_STRING (t), args, complain, in_decl),
7748 tsubst_expr (ASM_OUTPUTS (t), args, complain, in_decl),
7749 tsubst_expr (ASM_INPUTS (t), args, complain, in_decl),
7750 tsubst_expr (ASM_CLOBBERS (t), args, complain, in_decl));
7751 ASM_INPUT_P (tmp) = ASM_INPUT_P (t);
7758 stmt = begin_try_block ();
7759 tsubst_expr (TRY_STMTS (t), args, complain, in_decl);
7760 finish_cleanup_try_block (stmt);
7761 finish_cleanup (tsubst_expr (TRY_HANDLERS (t), args,
7767 if (FN_TRY_BLOCK_P (t))
7768 stmt = begin_function_try_block ();
7770 stmt = begin_try_block ();
7772 tsubst_expr (TRY_STMTS (t), args, complain, in_decl);
7774 if (FN_TRY_BLOCK_P (t))
7775 finish_function_try_block (stmt);
7777 finish_try_block (stmt);
7779 tsubst_expr (TRY_HANDLERS (t), args, complain, in_decl);
7780 if (FN_TRY_BLOCK_P (t))
7781 finish_function_handler_sequence (stmt);
7783 finish_handler_sequence (stmt);
7792 stmt = begin_handler ();
7793 if (HANDLER_PARMS (t))
7795 decl = DECL_STMT_DECL (HANDLER_PARMS (t));
7796 decl = tsubst (decl, args, complain, in_decl);
7797 /* Prevent instantiate_decl from trying to instantiate
7798 this variable. We've already done all that needs to be
7800 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
7804 finish_handler_parms (decl, stmt);
7805 tsubst_expr (HANDLER_BODY (t), args, complain, in_decl);
7806 finish_handler (stmt);
7812 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
7819 return tsubst_expr (TREE_CHAIN (t), args, complain | stmt_expr, in_decl);
7822 /* T is a postfix-expression that is not being used in a function
7823 call. Return the substituted version of T. */
7826 tsubst_non_call_postfix_expression (tree t, tree args,
7827 tsubst_flags_t complain,
7830 if (TREE_CODE (t) == SCOPE_REF)
7831 t = tsubst_qualified_id (t, args, complain, in_decl,
7832 /*done=*/false, /*address_p=*/false);
7834 t = tsubst_copy_and_build (t, args, complain, in_decl,
7835 /*function_p=*/false);
7840 /* Like tsubst but deals with expressions and performs semantic
7841 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
7844 tsubst_copy_and_build (tree t,
7846 tsubst_flags_t complain,
7850 #define RECUR(NODE) \
7851 tsubst_copy_and_build (NODE, args, complain, in_decl, /*function_p=*/false)
7855 if (t == NULL_TREE || t == error_mark_node)
7858 switch (TREE_CODE (t))
7863 case IDENTIFIER_NODE:
7867 tree qualifying_class;
7868 bool non_constant_expression_p;
7869 const char *error_msg;
7871 if (IDENTIFIER_TYPENAME_P (t))
7873 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
7874 t = mangle_conv_op_name_for_type (new_type);
7877 /* Look up the name. */
7878 decl = lookup_name (t, 0);
7880 /* By convention, expressions use ERROR_MARK_NODE to indicate
7881 failure, not NULL_TREE. */
7882 if (decl == NULL_TREE)
7883 decl = error_mark_node;
7885 decl = finish_id_expression (t, decl, NULL_TREE,
7888 /*constant_expression_p=*/false,
7889 /*allow_non_constant_expression_p=*/false,
7890 &non_constant_expression_p,
7894 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
7895 decl = unqualified_name_lookup_error (decl);
7899 case TEMPLATE_ID_EXPR:
7902 tree template = RECUR (TREE_OPERAND (t, 0));
7903 tree targs = TREE_OPERAND (t, 1);
7906 targs = tsubst_template_args (targs, args, complain, in_decl);
7908 if (TREE_CODE (template) == COMPONENT_REF)
7910 object = TREE_OPERAND (template, 0);
7911 template = TREE_OPERAND (template, 1);
7915 template = lookup_template_function (template, targs);
7918 return build (COMPONENT_REF, TREE_TYPE (template),
7925 return build_x_indirect_ref (RECUR (TREE_OPERAND (t, 0)), "unary *");
7928 return build_functional_cast
7929 (tsubst (TREE_TYPE (t), args, complain, in_decl),
7930 RECUR (TREE_OPERAND (t, 0)));
7932 case REINTERPRET_CAST_EXPR:
7933 return build_reinterpret_cast
7934 (tsubst (TREE_TYPE (t), args, complain, in_decl),
7935 RECUR (TREE_OPERAND (t, 0)));
7937 case CONST_CAST_EXPR:
7938 return build_const_cast
7939 (tsubst (TREE_TYPE (t), args, complain, in_decl),
7940 RECUR (TREE_OPERAND (t, 0)));
7942 case DYNAMIC_CAST_EXPR:
7943 return build_dynamic_cast
7944 (tsubst (TREE_TYPE (t), args, complain, in_decl),
7945 RECUR (TREE_OPERAND (t, 0)));
7947 case STATIC_CAST_EXPR:
7948 return build_static_cast
7949 (tsubst (TREE_TYPE (t), args, complain, in_decl),
7950 RECUR (TREE_OPERAND (t, 0)));
7952 case POSTDECREMENT_EXPR:
7953 case POSTINCREMENT_EXPR:
7954 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
7955 args, complain, in_decl);
7956 return build_x_unary_op (TREE_CODE (t), op1);
7958 case PREDECREMENT_EXPR:
7959 case PREINCREMENT_EXPR:
7963 case TRUTH_NOT_EXPR:
7964 case CONVERT_EXPR: /* Unary + */
7967 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)));
7970 op1 = TREE_OPERAND (t, 0);
7971 if (TREE_CODE (op1) == SCOPE_REF)
7972 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
7973 /*done=*/true, /*address_p=*/true);
7975 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
7977 if (TREE_CODE (op1) == LABEL_DECL)
7978 return finish_label_address_expr (DECL_NAME (op1));
7979 return build_x_unary_op (ADDR_EXPR, op1);
7984 case TRUNC_DIV_EXPR:
7986 case FLOOR_DIV_EXPR:
7987 case ROUND_DIV_EXPR:
7988 case EXACT_DIV_EXPR:
7992 case TRUNC_MOD_EXPR:
7993 case FLOOR_MOD_EXPR:
7994 case TRUTH_ANDIF_EXPR:
7995 case TRUTH_ORIF_EXPR:
7996 case TRUTH_AND_EXPR:
8012 return build_x_binary_op
8014 RECUR (TREE_OPERAND (t, 0)),
8015 RECUR (TREE_OPERAND (t, 1)));
8018 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
8019 /*address_p=*/false);
8022 if (tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl)
8025 return build_nt (ARRAY_REF, NULL_TREE, RECUR (TREE_OPERAND (t, 1)));
8027 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
8028 args, complain, in_decl);
8029 /* Remember that there was a reference to this entity. */
8032 return grok_array_decl (op1, RECUR (TREE_OPERAND (t, 1)));
8036 op1 = TREE_OPERAND (t, 0);
8039 /* When there are no ARGS, we are trying to evaluate a
8040 non-dependent expression from the parser. Trying to do
8041 the substitutions may not work. */
8043 op1 = TREE_TYPE (op1);
8052 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t), true);
8054 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t));
8057 return build_x_modify_expr
8058 (RECUR (TREE_OPERAND (t, 0)),
8059 TREE_CODE (TREE_OPERAND (t, 1)),
8060 RECUR (TREE_OPERAND (t, 2)));
8063 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
8064 args, complain, in_decl);
8065 /* Remember that there was a reference to this entity. */
8068 return build_x_arrow (op1);
8072 (RECUR (TREE_OPERAND (t, 0)),
8073 RECUR (TREE_OPERAND (t, 1)),
8074 RECUR (TREE_OPERAND (t, 2)),
8075 NEW_EXPR_USE_GLOBAL (t));
8078 return delete_sanity
8079 (RECUR (TREE_OPERAND (t, 0)),
8080 RECUR (TREE_OPERAND (t, 1)),
8081 DELETE_EXPR_USE_VEC (t),
8082 DELETE_EXPR_USE_GLOBAL (t));
8085 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
8086 RECUR (TREE_OPERAND (t, 1)));
8095 function = TREE_OPERAND (t, 0);
8096 /* When we parsed the expression, we determined whether or
8097 not Koenig lookup should be performed. */
8098 koenig_p = KOENIG_LOOKUP_P (t);
8099 if (TREE_CODE (function) == SCOPE_REF)
8102 function = tsubst_qualified_id (function, args, complain, in_decl,
8104 /*address_p=*/false);
8108 qualified_p = (TREE_CODE (function) == COMPONENT_REF
8109 && (TREE_CODE (TREE_OPERAND (function, 1))
8111 function = tsubst_copy_and_build (function, args, complain,
8114 if (BASELINK_P (function))
8118 call_args = RECUR (TREE_OPERAND (t, 1));
8121 && (is_overloaded_fn (function)
8122 || DECL_P (function)
8123 || TREE_CODE (function) == IDENTIFIER_NODE))
8124 function = perform_koenig_lookup (function, call_args);
8126 if (TREE_CODE (function) == IDENTIFIER_NODE)
8128 unqualified_name_lookup_error (function);
8129 return error_mark_node;
8132 /* Remember that there was a reference to this entity. */
8133 if (DECL_P (function))
8134 mark_used (function);
8136 function = convert_from_reference (function);
8138 if (TREE_CODE (function) == OFFSET_REF)
8139 return build_offset_ref_call_from_tree (function, call_args);
8140 if (TREE_CODE (function) == COMPONENT_REF)
8141 return (build_new_method_call
8142 (TREE_OPERAND (function, 0),
8143 TREE_OPERAND (function, 1),
8144 call_args, NULL_TREE,
8145 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL));
8146 return finish_call_expr (function, call_args,
8147 /*disallow_virtual=*/qualified_p,
8152 return build_x_conditional_expr
8153 (RECUR (TREE_OPERAND (t, 0)),
8154 RECUR (TREE_OPERAND (t, 1)),
8155 RECUR (TREE_OPERAND (t, 2)));
8157 case PSEUDO_DTOR_EXPR:
8158 return finish_pseudo_destructor_expr
8159 (RECUR (TREE_OPERAND (t, 0)),
8160 RECUR (TREE_OPERAND (t, 1)),
8161 RECUR (TREE_OPERAND (t, 2)));
8165 tree purpose, value, chain;
8167 if (t == void_list_node)
8170 purpose = TREE_PURPOSE (t);
8172 purpose = RECUR (purpose);
8173 value = TREE_VALUE (t);
8175 value = RECUR (value);
8176 chain = TREE_CHAIN (t);
8177 if (chain && chain != void_type_node)
8178 chain = RECUR (chain);
8179 if (purpose == TREE_PURPOSE (t)
8180 && value == TREE_VALUE (t)
8181 && chain == TREE_CHAIN (t))
8183 return tree_cons (purpose, value, chain);
8191 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
8192 args, complain, in_decl);
8193 /* Remember that there was a reference to this entity. */
8194 if (DECL_P (object))
8197 member = TREE_OPERAND (t, 1);
8198 if (BASELINK_P (member))
8199 member = tsubst_baselink (member,
8200 non_reference (TREE_TYPE (object)),
8201 args, complain, in_decl);
8203 member = tsubst_copy (member, args, complain, in_decl);
8205 if (!CLASS_TYPE_P (TREE_TYPE (object)))
8207 if (TREE_CODE (member) == BIT_NOT_EXPR)
8208 return finish_pseudo_destructor_expr (object,
8210 TREE_TYPE (object));
8211 else if (TREE_CODE (member) == SCOPE_REF
8212 && (TREE_CODE (TREE_OPERAND (member, 1)) == BIT_NOT_EXPR))
8213 return finish_pseudo_destructor_expr (object,
8215 TREE_TYPE (object));
8217 else if (TREE_CODE (member) == SCOPE_REF
8218 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
8223 /* Lookup the template functions now that we know what the
8225 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
8226 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
8227 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
8228 /*is_type=*/0, /*complain=*/false);
8229 if (BASELINK_P (member))
8230 BASELINK_FUNCTIONS (member)
8231 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
8235 qualified_name_lookup_error (TREE_TYPE (object), tmpl);
8236 return error_mark_node;
8239 else if (TREE_CODE (member) == FIELD_DECL)
8240 return finish_non_static_data_member (member, object, NULL_TREE);
8242 return finish_class_member_access_expr (object, member);
8247 (RECUR (TREE_OPERAND (t, 0)));
8253 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8256 /* digest_init will do the wrong thing if we let it. */
8257 if (type && TYPE_PTRMEMFUNC_P (type))
8261 /* We do not want to process the purpose of aggregate
8262 initializers as they are identifier nodes which will be
8263 looked up by digest_init. */
8264 purpose_p = !(type && IS_AGGR_TYPE (type));
8265 for (elts = CONSTRUCTOR_ELTS (t);
8267 elts = TREE_CHAIN (elts))
8269 tree purpose = TREE_PURPOSE (elts);
8270 tree value = TREE_VALUE (elts);
8272 if (purpose && purpose_p)
8273 purpose = RECUR (purpose);
8274 value = RECUR (value);
8275 r = tree_cons (purpose, value, r);
8278 r = build_constructor (NULL_TREE, nreverse (r));
8279 TREE_HAS_CONSTRUCTOR (r) = TREE_HAS_CONSTRUCTOR (t);
8282 return digest_init (type, r, 0);
8288 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
8289 if (TYPE_P (operand_0))
8290 return get_typeid (operand_0);
8291 return build_typeid (operand_0);
8295 return convert_from_reference (tsubst_copy (t, args, complain, in_decl));
8299 t = tsubst_copy (t, args, complain, in_decl);
8301 /* If there are no ARGS, then we are evaluating a
8302 non-dependent expression. If the expression is
8303 non-dependent, the variable must be a constant. */
8304 t = DECL_INITIAL (t);
8305 return convert_from_reference (t);
8308 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
8309 tsubst_copy (TREE_TYPE (t), args, complain,
8313 return tsubst_copy (t, args, complain, in_decl);
8319 /* Verify that the instantiated ARGS are valid. For type arguments,
8320 make sure that the type's linkage is ok. For non-type arguments,
8321 make sure they are constants if they are integral or enumerations.
8322 Emit an error under control of COMPLAIN, and return TRUE on error. */
8325 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
8327 int ix, len = DECL_NTPARMS (tmpl);
8328 bool result = false;
8330 for (ix = 0; ix != len; ix++)
8332 tree t = TREE_VEC_ELT (args, ix);
8336 /* [basic.link]: A name with no linkage (notably, the name
8337 of a class or enumeration declared in a local scope)
8338 shall not be used to declare an entity with linkage.
8339 This implies that names with no linkage cannot be used as
8340 template arguments. */
8341 tree nt = no_linkage_check (t);
8345 if (!(complain & tf_error))
8347 else if (TYPE_ANONYMOUS_P (nt))
8348 error ("`%T' uses anonymous type", t);
8350 error ("`%T' uses local type `%T'", t, nt);
8353 /* In order to avoid all sorts of complications, we do not
8354 allow variably-modified types as template arguments. */
8355 else if (variably_modified_type_p (t))
8357 if (complain & tf_error)
8358 error ("`%T' is a variably modified type", t);
8362 /* A non-type argument of integral or enumerated type must be a
8364 else if (TREE_TYPE (t)
8365 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
8366 && !TREE_CONSTANT (t))
8368 if (complain & tf_error)
8369 error ("integral expression `%E' is not constant", t);
8373 if (result && complain & tf_error)
8374 error (" trying to instantiate `%D'", tmpl);
8378 /* Instantiate the indicated variable or function template TMPL with
8379 the template arguments in TARG_PTR. */
8382 instantiate_template (tree tmpl, tree targ_ptr, tsubst_flags_t complain)
8388 if (tmpl == error_mark_node)
8389 return error_mark_node;
8391 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 283);
8393 /* If this function is a clone, handle it specially. */
8394 if (DECL_CLONED_FUNCTION_P (tmpl))
8396 tree spec = instantiate_template (DECL_CLONED_FUNCTION (tmpl), targ_ptr,
8400 /* Look for the clone. */
8401 for (clone = TREE_CHAIN (spec);
8402 clone && DECL_CLONED_FUNCTION_P (clone);
8403 clone = TREE_CHAIN (clone))
8404 if (DECL_NAME (clone) == DECL_NAME (tmpl))
8406 /* We should always have found the clone by now. */
8411 /* Check to see if we already have this specialization. */
8412 spec = retrieve_specialization (tmpl, targ_ptr);
8413 if (spec != NULL_TREE)
8416 gen_tmpl = most_general_template (tmpl);
8417 if (tmpl != gen_tmpl)
8419 /* The TMPL is a partial instantiation. To get a full set of
8420 arguments we must add the arguments used to perform the
8421 partial instantiation. */
8422 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
8425 /* Check to see if we already have this specialization. */
8426 spec = retrieve_specialization (gen_tmpl, targ_ptr);
8427 if (spec != NULL_TREE)
8431 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
8433 return error_mark_node;
8435 /* We are building a FUNCTION_DECL, during which the access of its
8436 parameters and return types have to be checked. However this
8437 FUNCTION_DECL which is the desired context for access checking
8438 is not built yet. We solve this chicken-and-egg problem by
8439 deferring all checks until we have the FUNCTION_DECL. */
8440 push_deferring_access_checks (dk_deferred);
8442 /* substitute template parameters */
8443 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
8444 targ_ptr, complain, gen_tmpl);
8446 /* Now we know the specialization, compute access previously
8448 push_access_scope (fndecl);
8449 perform_deferred_access_checks ();
8450 pop_access_scope (fndecl);
8451 pop_deferring_access_checks ();
8453 /* The DECL_TI_TEMPLATE should always be the immediate parent
8454 template, not the most general template. */
8455 DECL_TI_TEMPLATE (fndecl) = tmpl;
8457 if (flag_external_templates)
8458 add_pending_template (fndecl);
8460 /* If we've just instantiated the main entry point for a function,
8461 instantiate all the alternate entry points as well. We do this
8462 by cloning the instantiation of the main entry point, not by
8463 instantiating the template clones. */
8464 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
8465 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
8470 /* The FN is a TEMPLATE_DECL for a function. The ARGS are the
8471 arguments that are being used when calling it. TARGS is a vector
8472 into which the deduced template arguments are placed.
8474 Return zero for success, 2 for an incomplete match that doesn't resolve
8475 all the types, and 1 for complete failure. An error message will be
8476 printed only for an incomplete match.
8478 If FN is a conversion operator, or we are trying to produce a specific
8479 specialization, RETURN_TYPE is the return type desired.
8481 The EXPLICIT_TARGS are explicit template arguments provided via a
8484 The parameter STRICT is one of:
8487 We are deducing arguments for a function call, as in
8491 We are deducing arguments for a conversion function, as in
8495 We are deducing arguments when doing an explicit instantiation
8496 as in [temp.explicit], when determining an explicit specialization
8497 as in [temp.expl.spec], or when taking the address of a function
8498 template, as in [temp.deduct.funcaddr].
8501 We are deducing arguments when calculating the partial
8502 ordering between specializations of function or class
8503 templates, as in [temp.func.order] and [temp.class.order].
8505 LEN is the number of parms to consider before returning success, or -1
8506 for all. This is used in partial ordering to avoid comparing parms for
8507 which no actual argument was passed, since they are not considered in
8508 overload resolution (and are explicitly excluded from consideration in
8509 partial ordering in [temp.func.order]/6). */
8512 fn_type_unification (tree fn,
8513 tree explicit_targs,
8517 unification_kind_t strict,
8524 my_friendly_assert (TREE_CODE (fn) == TEMPLATE_DECL, 0);
8526 fntype = TREE_TYPE (fn);
8531 The specified template arguments must match the template
8532 parameters in kind (i.e., type, nontype, template), and there
8533 must not be more arguments than there are parameters;
8534 otherwise type deduction fails.
8536 Nontype arguments must match the types of the corresponding
8537 nontype template parameters, or must be convertible to the
8538 types of the corresponding nontype parameters as specified in
8539 _temp.arg.nontype_, otherwise type deduction fails.
8541 All references in the function type of the function template
8542 to the corresponding template parameters are replaced by the
8543 specified template argument values. If a substitution in a
8544 template parameter or in the function type of the function
8545 template results in an invalid type, type deduction fails. */
8547 tree converted_args;
8551 = (coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
8552 explicit_targs, NULL_TREE, tf_none,
8553 /*require_all_arguments=*/0));
8554 if (converted_args == error_mark_node)
8557 /* Substitute the explicit args into the function type. This is
8558 necessary so that, for instance, explicitly declared function
8559 arguments can match null pointed constants. If we were given
8560 an incomplete set of explicit args, we must not do semantic
8561 processing during substitution as we could create partial
8563 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
8564 processing_template_decl += incomplete;
8565 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
8566 processing_template_decl -= incomplete;
8568 if (fntype == error_mark_node)
8571 /* Place the explicitly specified arguments in TARGS. */
8572 for (i = NUM_TMPL_ARGS (converted_args); i--;)
8573 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
8576 parms = TYPE_ARG_TYPES (fntype);
8577 /* Never do unification on the 'this' parameter. */
8578 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
8579 parms = TREE_CHAIN (parms);
8583 /* We've been given a return type to match, prepend it. */
8584 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
8585 args = tree_cons (NULL_TREE, return_type, args);
8590 /* We allow incomplete unification without an error message here
8591 because the standard doesn't seem to explicitly prohibit it. Our
8592 callers must be ready to deal with unification failures in any
8594 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
8595 targs, parms, args, /*subr=*/0,
8596 strict, /*allow_incomplete*/1, len);
8599 /* All is well so far. Now, check:
8603 When all template arguments have been deduced, all uses of
8604 template parameters in nondeduced contexts are replaced with
8605 the corresponding deduced argument values. If the
8606 substitution results in an invalid type, as described above,
8607 type deduction fails. */
8608 if (tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE)
8615 /* Adjust types before performing type deduction, as described in
8616 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
8617 sections are symmetric. PARM is the type of a function parameter
8618 or the return type of the conversion function. ARG is the type of
8619 the argument passed to the call, or the type of the value
8620 initialized with the result of the conversion function. */
8623 maybe_adjust_types_for_deduction (unification_kind_t strict,
8636 /* Swap PARM and ARG throughout the remainder of this
8637 function; the handling is precisely symmetric since PARM
8638 will initialize ARG rather than vice versa. */
8646 /* There is nothing to do in this case. */
8650 /* DR 214. [temp.func.order] is underspecified, and leads to no
8651 ordering between things like `T *' and `T const &' for `U *'.
8652 The former has T=U and the latter T=U*. The former looks more
8653 specialized and John Spicer considers it well-formed (the EDG
8654 compiler accepts it).
8656 John also confirms that deduction should proceed as in a function
8657 call. Which implies the usual ARG and PARM conversions as DEDUCE_CALL.
8658 However, in ordering, ARG can have REFERENCE_TYPE, but no argument
8659 to an actual call can have such a type.
8661 If both ARG and PARM are REFERENCE_TYPE, we change neither.
8662 If only ARG is a REFERENCE_TYPE, we look through that and then
8663 proceed as with DEDUCE_CALL (which could further convert it). */
8664 if (TREE_CODE (*arg) == REFERENCE_TYPE)
8666 if (TREE_CODE (*parm) == REFERENCE_TYPE)
8668 *arg = TREE_TYPE (*arg);
8675 if (TREE_CODE (*parm) != REFERENCE_TYPE)
8677 /* [temp.deduct.call]
8679 If P is not a reference type:
8681 --If A is an array type, the pointer type produced by the
8682 array-to-pointer standard conversion (_conv.array_) is
8683 used in place of A for type deduction; otherwise,
8685 --If A is a function type, the pointer type produced by
8686 the function-to-pointer standard conversion
8687 (_conv.func_) is used in place of A for type deduction;
8690 --If A is a cv-qualified type, the top level
8691 cv-qualifiers of A's type are ignored for type
8693 if (TREE_CODE (*arg) == ARRAY_TYPE)
8694 *arg = build_pointer_type (TREE_TYPE (*arg));
8695 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
8696 *arg = build_pointer_type (*arg);
8698 *arg = TYPE_MAIN_VARIANT (*arg);
8701 /* [temp.deduct.call]
8703 If P is a cv-qualified type, the top level cv-qualifiers
8704 of P's type are ignored for type deduction. If P is a
8705 reference type, the type referred to by P is used for
8707 *parm = TYPE_MAIN_VARIANT (*parm);
8708 if (TREE_CODE (*parm) == REFERENCE_TYPE)
8710 *parm = TREE_TYPE (*parm);
8711 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
8714 /* DR 322. For conversion deduction, remove a reference type on parm
8715 too (which has been swapped into ARG). */
8716 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
8717 *arg = TREE_TYPE (*arg);
8722 /* Most parms like fn_type_unification.
8724 If SUBR is 1, we're being called recursively (to unify the
8725 arguments of a function or method parameter of a function
8729 type_unification_real (tree tparms,
8734 unification_kind_t strict,
8735 int allow_incomplete,
8740 int ntparms = TREE_VEC_LENGTH (tparms);
8742 int saw_undeduced = 0;
8746 my_friendly_assert (TREE_CODE (tparms) == TREE_VEC, 289);
8747 my_friendly_assert (xparms == NULL_TREE
8748 || TREE_CODE (xparms) == TREE_LIST, 290);
8749 my_friendly_assert (!xargs || TREE_CODE (xargs) == TREE_LIST, 291);
8750 my_friendly_assert (ntparms > 0, 292);
8755 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
8756 | UNIFY_ALLOW_DERIVED);
8760 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
8764 sub_strict = UNIFY_ALLOW_NONE;
8768 sub_strict = UNIFY_ALLOW_NONE;
8784 && parms != void_list_node
8786 && args != void_list_node)
8788 parm = TREE_VALUE (parms);
8789 parms = TREE_CHAIN (parms);
8790 arg = TREE_VALUE (args);
8791 args = TREE_CHAIN (args);
8793 if (arg == error_mark_node)
8795 if (arg == unknown_type_node)
8796 /* We can't deduce anything from this, but we might get all the
8797 template args from other function args. */
8800 /* Conversions will be performed on a function argument that
8801 corresponds with a function parameter that contains only
8802 non-deducible template parameters and explicitly specified
8803 template parameters. */
8804 if (! uses_template_parms (parm))
8809 type = TREE_TYPE (arg);
8816 if (strict == DEDUCE_EXACT || strict == DEDUCE_ORDER)
8818 if (same_type_p (parm, type))
8822 /* It might work; we shouldn't check now, because we might
8823 get into infinite recursion. Overload resolution will
8832 my_friendly_assert (TREE_TYPE (arg) != NULL_TREE, 293);
8833 if (type_unknown_p (arg))
8835 /* [temp.deduct.type] A template-argument can be deduced from
8836 a pointer to function or pointer to member function
8837 argument if the set of overloaded functions does not
8838 contain function templates and at most one of a set of
8839 overloaded functions provides a unique match. */
8841 if (resolve_overloaded_unification
8842 (tparms, targs, parm, arg, strict, sub_strict)
8847 arg = TREE_TYPE (arg);
8848 if (arg == error_mark_node)
8853 int arg_strict = sub_strict;
8856 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg);
8858 if (unify (tparms, targs, parm, arg, arg_strict))
8862 /* Are we done with the interesting parms? */
8866 /* Fail if we've reached the end of the parm list, and more args
8867 are present, and the parm list isn't variadic. */
8868 if (args && args != void_list_node && parms == void_list_node)
8870 /* Fail if parms are left and they don't have default values. */
8872 && parms != void_list_node
8873 && TREE_PURPOSE (parms) == NULL_TREE)
8878 for (i = 0; i < ntparms; i++)
8879 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
8881 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
8883 /* If this is an undeduced nontype parameter that depends on
8884 a type parameter, try another pass; its type may have been
8885 deduced from a later argument than the one from which
8886 this parameter can be deduced. */
8887 if (TREE_CODE (tparm) == PARM_DECL
8888 && uses_template_parms (TREE_TYPE (tparm))
8889 && !saw_undeduced++)
8892 if (!allow_incomplete)
8893 error ("incomplete type unification");
8899 /* Subroutine of type_unification_real. Args are like the variables at the
8900 call site. ARG is an overloaded function (or template-id); we try
8901 deducing template args from each of the overloads, and if only one
8902 succeeds, we go with that. Modifies TARGS and returns 0 on success. */
8905 resolve_overloaded_unification (tree tparms,
8909 unification_kind_t strict,
8912 tree tempargs = copy_node (targs);
8915 if (TREE_CODE (arg) == ADDR_EXPR)
8916 arg = TREE_OPERAND (arg, 0);
8918 if (TREE_CODE (arg) == COMPONENT_REF)
8919 /* Handle `&x' where `x' is some static or non-static member
8921 arg = TREE_OPERAND (arg, 1);
8923 if (TREE_CODE (arg) == OFFSET_REF)
8924 arg = TREE_OPERAND (arg, 1);
8926 /* Strip baselink information. */
8927 if (BASELINK_P (arg))
8928 arg = BASELINK_FUNCTIONS (arg);
8930 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
8932 /* If we got some explicit template args, we need to plug them into
8933 the affected templates before we try to unify, in case the
8934 explicit args will completely resolve the templates in question. */
8936 tree expl_subargs = TREE_OPERAND (arg, 1);
8937 arg = TREE_OPERAND (arg, 0);
8939 for (; arg; arg = OVL_NEXT (arg))
8941 tree fn = OVL_CURRENT (arg);
8944 if (TREE_CODE (fn) != TEMPLATE_DECL)
8947 subargs = get_bindings_overload (fn, DECL_TEMPLATE_RESULT (fn),
8951 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
8952 if (TREE_CODE (elem) == METHOD_TYPE)
8953 elem = build_ptrmemfunc_type (build_pointer_type (elem));
8954 good += try_one_overload (tparms, targs, tempargs, parm, elem,
8955 strict, sub_strict);
8959 else if (TREE_CODE (arg) == OVERLOAD
8960 || TREE_CODE (arg) == FUNCTION_DECL)
8962 for (; arg; arg = OVL_NEXT (arg))
8964 tree type = TREE_TYPE (OVL_CURRENT (arg));
8965 if (TREE_CODE (type) == METHOD_TYPE)
8966 type = build_ptrmemfunc_type (build_pointer_type (type));
8967 good += try_one_overload (tparms, targs, tempargs, parm,
8969 strict, sub_strict);
8975 /* [temp.deduct.type] A template-argument can be deduced from a pointer
8976 to function or pointer to member function argument if the set of
8977 overloaded functions does not contain function templates and at most
8978 one of a set of overloaded functions provides a unique match.
8980 So if we found multiple possibilities, we return success but don't
8985 int i = TREE_VEC_LENGTH (targs);
8987 if (TREE_VEC_ELT (tempargs, i))
8988 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
8996 /* Subroutine of resolve_overloaded_unification; does deduction for a single
8997 overload. Fills TARGS with any deduced arguments, or error_mark_node if
8998 different overloads deduce different arguments for a given parm.
8999 Returns 1 on success. */
9002 try_one_overload (tree tparms,
9007 unification_kind_t strict,
9014 /* [temp.deduct.type] A template-argument can be deduced from a pointer
9015 to function or pointer to member function argument if the set of
9016 overloaded functions does not contain function templates and at most
9017 one of a set of overloaded functions provides a unique match.
9019 So if this is a template, just return success. */
9021 if (uses_template_parms (arg))
9024 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg);
9026 /* We don't copy orig_targs for this because if we have already deduced
9027 some template args from previous args, unify would complain when we
9028 try to deduce a template parameter for the same argument, even though
9029 there isn't really a conflict. */
9030 nargs = TREE_VEC_LENGTH (targs);
9031 tempargs = make_tree_vec (nargs);
9033 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
9036 /* First make sure we didn't deduce anything that conflicts with
9037 explicitly specified args. */
9038 for (i = nargs; i--; )
9040 tree elt = TREE_VEC_ELT (tempargs, i);
9041 tree oldelt = TREE_VEC_ELT (orig_targs, i);
9043 if (elt == NULL_TREE)
9045 else if (uses_template_parms (elt))
9047 /* Since we're unifying against ourselves, we will fill in template
9048 args used in the function parm list with our own template parms.
9050 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
9053 else if (oldelt && ! template_args_equal (oldelt, elt))
9057 for (i = nargs; i--; )
9059 tree elt = TREE_VEC_ELT (tempargs, i);
9062 TREE_VEC_ELT (targs, i) = elt;
9068 /* Verify that nondeduce template argument agrees with the type
9069 obtained from argument deduction. Return nonzero if the
9074 struct A { typedef int X; };
9075 template <class T, class U> struct C {};
9076 template <class T> struct C<T, typename T::X> {};
9078 Then with the instantiation `C<A, int>', we can deduce that
9079 `T' is `A' but unify () does not check whether `typename T::X'
9080 is `int'. This function ensure that they agree.
9082 TARGS, PARMS are the same as the arguments of unify.
9083 ARGS contains template arguments from all levels. */
9086 verify_class_unification (tree targs, tree parms, tree args)
9088 parms = tsubst (parms, add_outermost_template_args (args, targs),
9089 tf_none, NULL_TREE);
9090 if (parms == error_mark_node)
9093 return !comp_template_args (parms, INNERMOST_TEMPLATE_ARGS (args));
9096 /* PARM is a template class (perhaps with unbound template
9097 parameters). ARG is a fully instantiated type. If ARG can be
9098 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
9099 TARGS are as for unify. */
9102 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
9106 if (!CLASSTYPE_TEMPLATE_INFO (arg)
9107 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
9108 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
9111 /* We need to make a new template argument vector for the call to
9112 unify. If we used TARGS, we'd clutter it up with the result of
9113 the attempted unification, even if this class didn't work out.
9114 We also don't want to commit ourselves to all the unifications
9115 we've already done, since unification is supposed to be done on
9116 an argument-by-argument basis. In other words, consider the
9117 following pathological case:
9119 template <int I, int J, int K>
9122 template <int I, int J>
9123 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
9125 template <int I, int J, int K>
9126 void f(S<I, J, K>, S<I, I, I>);
9135 Now, by the time we consider the unification involving `s2', we
9136 already know that we must have `f<0, 0, 0>'. But, even though
9137 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
9138 because there are two ways to unify base classes of S<0, 1, 2>
9139 with S<I, I, I>. If we kept the already deduced knowledge, we
9140 would reject the possibility I=1. */
9141 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
9143 /* If unification failed, we're done. */
9144 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
9145 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
9151 /* Subroutine of get_template_base. RVAL, if non-NULL, is a base we
9152 have already discovered to be satisfactory. ARG_BINFO is the binfo
9153 for the base class of ARG that we are currently examining. */
9156 get_template_base_recursive (tree tparms,
9165 tree arg = BINFO_TYPE (arg_binfo);
9167 if (!(flags & GTB_IGNORE_TYPE))
9169 tree r = try_class_unification (tparms, targs,
9172 /* If there is more than one satisfactory baseclass, then:
9176 If they yield more than one possible deduced A, the type
9180 if (r && rval && !same_type_p (r, rval))
9181 return error_mark_node;
9186 binfos = BINFO_BASETYPES (arg_binfo);
9187 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
9189 /* Process base types. */
9190 for (i = 0; i < n_baselinks; i++)
9192 tree base_binfo = TREE_VEC_ELT (binfos, i);
9195 /* Skip this base, if we've already seen it. */
9196 if (BINFO_MARKED (base_binfo))
9200 (flags & GTB_VIA_VIRTUAL) || TREE_VIA_VIRTUAL (base_binfo);
9202 /* When searching for a non-virtual, we cannot mark virtually
9205 BINFO_MARKED (base_binfo) = 1;
9207 rval = get_template_base_recursive (tparms, targs,
9211 GTB_VIA_VIRTUAL * this_virtual);
9213 /* If we discovered more than one matching base class, we can
9215 if (rval == error_mark_node)
9216 return error_mark_node;
9222 /* Given a template type PARM and a class type ARG, find the unique
9223 base type in ARG that is an instance of PARM. We do not examine
9224 ARG itself; only its base-classes. If there is no appropriate base
9225 class, return NULL_TREE. If there is more than one, return
9226 error_mark_node. PARM may be the type of a partial specialization,
9227 as well as a plain template type. Used by unify. */
9230 get_template_base (tree tparms, tree targs, tree parm, tree arg)
9235 my_friendly_assert (IS_AGGR_TYPE_CODE (TREE_CODE (arg)), 92);
9237 arg_binfo = TYPE_BINFO (complete_type (arg));
9238 rval = get_template_base_recursive (tparms, targs,
9243 /* Since get_template_base_recursive marks the bases classes, we
9244 must unmark them here. */
9245 dfs_walk (arg_binfo, dfs_unmark, markedp, 0);
9250 /* Returns the level of DECL, which declares a template parameter. */
9253 template_decl_level (tree decl)
9255 switch (TREE_CODE (decl))
9259 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
9262 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
9270 /* Decide whether ARG can be unified with PARM, considering only the
9271 cv-qualifiers of each type, given STRICT as documented for unify.
9272 Returns nonzero iff the unification is OK on that basis.*/
9275 check_cv_quals_for_unify (int strict, tree arg, tree parm)
9277 int arg_quals = cp_type_quals (arg);
9278 int parm_quals = cp_type_quals (parm);
9280 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM)
9282 /* If the cvr quals of parm will not unify with ARG, they'll be
9283 ignored in instantiation, so we have to do the same here. */
9284 if (TREE_CODE (arg) == REFERENCE_TYPE)
9285 parm_quals &= ~(TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE);
9286 if (!POINTER_TYPE_P (arg) &&
9287 TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
9288 parm_quals &= ~TYPE_QUAL_RESTRICT;
9291 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
9292 && (arg_quals & parm_quals) != parm_quals)
9295 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
9296 && (parm_quals & arg_quals) != arg_quals)
9302 /* Takes parameters as for type_unification. Returns 0 if the
9303 type deduction succeeds, 1 otherwise. The parameter STRICT is a
9304 bitwise or of the following flags:
9307 Require an exact match between PARM and ARG.
9308 UNIFY_ALLOW_MORE_CV_QUAL:
9309 Allow the deduced ARG to be more cv-qualified (by qualification
9310 conversion) than ARG.
9311 UNIFY_ALLOW_LESS_CV_QUAL:
9312 Allow the deduced ARG to be less cv-qualified than ARG.
9313 UNIFY_ALLOW_DERIVED:
9314 Allow the deduced ARG to be a template base class of ARG,
9315 or a pointer to a template base class of the type pointed to by
9317 UNIFY_ALLOW_INTEGER:
9318 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
9319 case for more information.
9320 UNIFY_ALLOW_OUTER_LEVEL:
9321 This is the outermost level of a deduction. Used to determine validity
9322 of qualification conversions. A valid qualification conversion must
9323 have const qualified pointers leading up to the inner type which
9324 requires additional CV quals, except at the outer level, where const
9325 is not required [conv.qual]. It would be normal to set this flag in
9326 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
9327 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
9328 This is the outermost level of a deduction, and PARM can be more CV
9329 qualified at this point.
9330 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
9331 This is the outermost level of a deduction, and PARM can be less CV
9332 qualified at this point.
9333 UNIFY_ALLOW_MAX_CORRECTION:
9334 This is an INTEGER_TYPE's maximum value. Used if the range may
9335 have been derived from a size specification, such as an array size.
9336 If the size was given by a nontype template parameter N, the maximum
9337 value will have the form N-1. The flag says that we can (and indeed
9338 must) unify N with (ARG + 1), an exception to the normal rules on
9342 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
9347 int strict_in = strict;
9349 /* I don't think this will do the right thing with respect to types.
9350 But the only case I've seen it in so far has been array bounds, where
9351 signedness is the only information lost, and I think that will be
9353 while (TREE_CODE (parm) == NOP_EXPR)
9354 parm = TREE_OPERAND (parm, 0);
9356 if (arg == error_mark_node)
9358 if (arg == unknown_type_node)
9359 /* We can't deduce anything from this, but we might get all the
9360 template args from other function args. */
9363 /* If PARM uses template parameters, then we can't bail out here,
9364 even if ARG == PARM, since we won't record unifications for the
9365 template parameters. We might need them if we're trying to
9366 figure out which of two things is more specialized. */
9367 if (arg == parm && !uses_template_parms (parm))
9370 /* Immediately reject some pairs that won't unify because of
9371 cv-qualification mismatches. */
9372 if (TREE_CODE (arg) == TREE_CODE (parm)
9374 /* It is the elements of the array which hold the cv quals of an array
9375 type, and the elements might be template type parms. We'll check
9377 && TREE_CODE (arg) != ARRAY_TYPE
9378 /* We check the cv-qualifiers when unifying with template type
9379 parameters below. We want to allow ARG `const T' to unify with
9380 PARM `T' for example, when computing which of two templates
9381 is more specialized, for example. */
9382 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
9383 && !check_cv_quals_for_unify (strict_in, arg, parm))
9386 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
9387 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
9388 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
9389 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
9390 strict &= ~UNIFY_ALLOW_DERIVED;
9391 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
9392 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
9393 strict &= ~UNIFY_ALLOW_MAX_CORRECTION;
9395 switch (TREE_CODE (parm))
9399 case UNBOUND_CLASS_TEMPLATE:
9400 /* In a type which contains a nested-name-specifier, template
9401 argument values cannot be deduced for template parameters used
9402 within the nested-name-specifier. */
9405 case TEMPLATE_TYPE_PARM:
9406 case TEMPLATE_TEMPLATE_PARM:
9407 case BOUND_TEMPLATE_TEMPLATE_PARM:
9408 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
9410 if (TEMPLATE_TYPE_LEVEL (parm)
9411 != template_decl_level (tparm))
9412 /* The PARM is not one we're trying to unify. Just check
9413 to see if it matches ARG. */
9414 return (TREE_CODE (arg) == TREE_CODE (parm)
9415 && same_type_p (parm, arg)) ? 0 : 1;
9416 idx = TEMPLATE_TYPE_IDX (parm);
9417 targ = TREE_VEC_ELT (targs, idx);
9418 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
9420 /* Check for mixed types and values. */
9421 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
9422 && TREE_CODE (tparm) != TYPE_DECL)
9423 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
9424 && TREE_CODE (tparm) != TEMPLATE_DECL))
9427 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
9429 /* ARG must be constructed from a template class or a template
9430 template parameter. */
9431 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
9432 && (TREE_CODE (arg) != RECORD_TYPE || !CLASSTYPE_TEMPLATE_INFO (arg)))
9436 tree parmtmpl = TYPE_TI_TEMPLATE (parm);
9437 tree parmvec = TYPE_TI_ARGS (parm);
9438 tree argvec = TYPE_TI_ARGS (arg);
9440 = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_TI_TEMPLATE (arg));
9443 /* The parameter and argument roles have to be switched here
9444 in order to handle default arguments properly. For example,
9445 template<template <class> class TT> void f(TT<int>)
9446 should be able to accept vector<int> which comes from
9447 template <class T, class Allocator = allocator>
9450 if (coerce_template_parms (argtmplvec, parmvec, parmtmpl, 0, 1)
9454 /* Deduce arguments T, i from TT<T> or TT<i>.
9455 We check each element of PARMVEC and ARGVEC individually
9456 rather than the whole TREE_VEC since they can have
9457 different number of elements. */
9459 for (i = 0; i < TREE_VEC_LENGTH (parmvec); ++i)
9461 tree t = TREE_VEC_ELT (parmvec, i);
9463 if (unify (tparms, targs, t,
9464 TREE_VEC_ELT (argvec, i),
9469 arg = TYPE_TI_TEMPLATE (arg);
9471 /* Fall through to deduce template name. */
9474 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
9475 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
9477 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
9479 /* Simple cases: Value already set, does match or doesn't. */
9480 if (targ != NULL_TREE && template_args_equal (targ, arg))
9487 /* If PARM is `const T' and ARG is only `int', we don't have
9488 a match unless we are allowing additional qualification.
9489 If ARG is `const int' and PARM is just `T' that's OK;
9490 that binds `const int' to `T'. */
9491 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
9495 /* Consider the case where ARG is `const volatile int' and
9496 PARM is `const T'. Then, T should be `volatile int'. */
9497 arg = cp_build_qualified_type_real
9498 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
9499 if (arg == error_mark_node)
9502 /* Simple cases: Value already set, does match or doesn't. */
9503 if (targ != NULL_TREE && same_type_p (targ, arg))
9508 /* Make sure that ARG is not a variable-sized array. (Note
9509 that were talking about variable-sized arrays (like
9510 `int[n]'), rather than arrays of unknown size (like
9511 `int[]').) We'll get very confused by such a type since
9512 the bound of the array will not be computable in an
9513 instantiation. Besides, such types are not allowed in
9514 ISO C++, so we can do as we please here. */
9515 if (variably_modified_type_p (arg))
9519 TREE_VEC_ELT (targs, idx) = arg;
9522 case TEMPLATE_PARM_INDEX:
9523 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
9525 if (TEMPLATE_PARM_LEVEL (parm)
9526 != template_decl_level (tparm))
9527 /* The PARM is not one we're trying to unify. Just check
9528 to see if it matches ARG. */
9529 return !(TREE_CODE (arg) == TREE_CODE (parm)
9530 && cp_tree_equal (parm, arg));
9532 idx = TEMPLATE_PARM_IDX (parm);
9533 targ = TREE_VEC_ELT (targs, idx);
9536 return !cp_tree_equal (targ, arg);
9538 /* [temp.deduct.type] If, in the declaration of a function template
9539 with a non-type template-parameter, the non-type
9540 template-parameter is used in an expression in the function
9541 parameter-list and, if the corresponding template-argument is
9542 deduced, the template-argument type shall match the type of the
9543 template-parameter exactly, except that a template-argument
9544 deduced from an array bound may be of any integral type.
9545 The non-type parameter might use already deduced type parameters. */
9546 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
9547 if (!TREE_TYPE (arg))
9548 /* Template-parameter dependent expression. Just accept it for now.
9549 It will later be processed in convert_template_argument. */
9551 else if (same_type_p (TREE_TYPE (arg), tparm))
9553 else if ((strict & UNIFY_ALLOW_INTEGER)
9554 && (TREE_CODE (tparm) == INTEGER_TYPE
9555 || TREE_CODE (tparm) == BOOLEAN_TYPE))
9557 else if (uses_template_parms (tparm))
9558 /* We haven't deduced the type of this parameter yet. Try again
9564 TREE_VEC_ELT (targs, idx) = arg;
9569 if (TREE_CODE (arg) != POINTER_TYPE)
9572 /* [temp.deduct.call]
9574 A can be another pointer or pointer to member type that can
9575 be converted to the deduced A via a qualification
9576 conversion (_conv.qual_).
9578 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
9579 This will allow for additional cv-qualification of the
9580 pointed-to types if appropriate. */
9582 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
9583 /* The derived-to-base conversion only persists through one
9584 level of pointers. */
9585 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
9587 return unify (tparms, targs, TREE_TYPE (parm),
9588 TREE_TYPE (arg), strict);
9591 case REFERENCE_TYPE:
9592 if (TREE_CODE (arg) != REFERENCE_TYPE)
9594 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
9595 strict & UNIFY_ALLOW_MORE_CV_QUAL);
9598 if (TREE_CODE (arg) != ARRAY_TYPE)
9600 if ((TYPE_DOMAIN (parm) == NULL_TREE)
9601 != (TYPE_DOMAIN (arg) == NULL_TREE))
9603 if (TYPE_DOMAIN (parm) != NULL_TREE
9604 && unify (tparms, targs, TYPE_DOMAIN (parm),
9605 TYPE_DOMAIN (arg), UNIFY_ALLOW_NONE) != 0)
9607 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
9608 strict & UNIFY_ALLOW_MORE_CV_QUAL);
9616 if (TREE_CODE (arg) != TREE_CODE (parm))
9619 if (TREE_CODE (parm) == INTEGER_TYPE
9620 && TREE_CODE (TYPE_MAX_VALUE (parm)) != INTEGER_CST)
9622 if (TYPE_MIN_VALUE (parm) && TYPE_MIN_VALUE (arg)
9623 && unify (tparms, targs, TYPE_MIN_VALUE (parm),
9624 TYPE_MIN_VALUE (arg), UNIFY_ALLOW_INTEGER))
9626 if (TYPE_MAX_VALUE (parm) && TYPE_MAX_VALUE (arg)
9627 && unify (tparms, targs, TYPE_MAX_VALUE (parm),
9628 TYPE_MAX_VALUE (arg),
9629 UNIFY_ALLOW_INTEGER | UNIFY_ALLOW_MAX_CORRECTION))
9632 /* We have already checked cv-qualification at the top of the
9634 else if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
9637 /* As far as unification is concerned, this wins. Later checks
9638 will invalidate it if necessary. */
9641 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
9642 /* Type INTEGER_CST can come from ordinary constant template args. */
9644 while (TREE_CODE (arg) == NOP_EXPR)
9645 arg = TREE_OPERAND (arg, 0);
9647 if (TREE_CODE (arg) != INTEGER_CST)
9649 return !tree_int_cst_equal (parm, arg);
9654 if (TREE_CODE (arg) != TREE_VEC)
9656 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
9658 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
9659 if (unify (tparms, targs,
9660 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
9668 if (TREE_CODE (arg) != TREE_CODE (parm))
9671 if (TYPE_PTRMEMFUNC_P (parm))
9673 if (!TYPE_PTRMEMFUNC_P (arg))
9676 return unify (tparms, targs,
9677 TYPE_PTRMEMFUNC_FN_TYPE (parm),
9678 TYPE_PTRMEMFUNC_FN_TYPE (arg),
9682 if (CLASSTYPE_TEMPLATE_INFO (parm))
9686 if (strict_in & UNIFY_ALLOW_DERIVED)
9688 /* First, we try to unify the PARM and ARG directly. */
9689 t = try_class_unification (tparms, targs,
9694 /* Fallback to the special case allowed in
9697 If P is a class, and P has the form
9698 template-id, then A can be a derived class of
9699 the deduced A. Likewise, if P is a pointer to
9700 a class of the form template-id, A can be a
9701 pointer to a derived class pointed to by the
9703 t = get_template_base (tparms, targs,
9706 if (! t || t == error_mark_node)
9710 else if (CLASSTYPE_TEMPLATE_INFO (arg)
9711 && (CLASSTYPE_TI_TEMPLATE (parm)
9712 == CLASSTYPE_TI_TEMPLATE (arg)))
9713 /* Perhaps PARM is something like S<U> and ARG is S<int>.
9714 Then, we should unify `int' and `U'. */
9717 /* There's no chance of unification succeeding. */
9720 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
9721 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
9723 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
9729 if (TREE_CODE (arg) != TREE_CODE (parm))
9732 if (unify (tparms, targs, TREE_TYPE (parm),
9733 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
9735 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
9736 TYPE_ARG_TYPES (arg), 1,
9737 DEDUCE_EXACT, 0, -1);
9740 if (TREE_CODE (arg) != OFFSET_TYPE)
9742 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
9743 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
9745 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
9749 if (DECL_TEMPLATE_PARM_P (parm))
9750 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
9751 if (arg != decl_constant_value (parm))
9756 /* Matched cases are handled by the ARG == PARM test above. */
9760 if (tree_int_cst_equal (TREE_OPERAND (parm, 1), integer_one_node)
9761 && (strict_in & UNIFY_ALLOW_MAX_CORRECTION))
9763 /* We handle this case specially, since it comes up with
9764 arrays. In particular, something like:
9766 template <int N> void f(int (&x)[N]);
9768 Here, we are trying to unify the range type, which
9769 looks like [0 ... (N - 1)]. */
9771 t1 = TREE_OPERAND (parm, 0);
9772 t2 = TREE_OPERAND (parm, 1);
9774 t = fold (build (PLUS_EXPR, integer_type_node, arg, t2));
9776 return unify (tparms, targs, t1, t, strict);
9778 /* else fall through */
9781 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (parm))))
9784 /* We're looking at an expression. This can happen with
9788 void foo(S<I>, S<I + 2>);
9790 This is a "nondeduced context":
9794 The nondeduced contexts are:
9796 --A type that is a template-id in which one or more of
9797 the template-arguments is an expression that references
9798 a template-parameter.
9800 In these cases, we assume deduction succeeded, but don't
9801 actually infer any unifications. */
9803 if (!uses_template_parms (parm)
9804 && !template_args_equal (parm, arg))
9810 sorry ("use of `%s' in template type unification",
9811 tree_code_name [(int) TREE_CODE (parm)]);
9817 /* Called if RESULT is explicitly instantiated, or is a member of an
9818 explicitly instantiated class, or if using -frepo and the
9819 instantiation of RESULT has been assigned to this file. */
9822 mark_decl_instantiated (tree result, int extern_p)
9824 /* We used to set this unconditionally; we moved that to
9825 do_decl_instantiation so it wouldn't get set on members of
9826 explicit class template instantiations. But we still need to set
9827 it here for the 'extern template' case in order to suppress
9828 implicit instantiations. */
9830 SET_DECL_EXPLICIT_INSTANTIATION (result);
9832 /* If this entity has already been written out, it's too late to
9833 make any modifications. */
9834 if (TREE_ASM_WRITTEN (result))
9837 if (TREE_CODE (result) != FUNCTION_DECL)
9838 /* The TREE_PUBLIC flag for function declarations will have been
9839 set correctly by tsubst. */
9840 TREE_PUBLIC (result) = 1;
9842 /* This might have been set by an earlier implicit instantiation. */
9843 DECL_COMDAT (result) = 0;
9847 DECL_INTERFACE_KNOWN (result) = 1;
9848 DECL_NOT_REALLY_EXTERN (result) = 1;
9850 /* Always make artificials weak. */
9851 if (DECL_ARTIFICIAL (result) && flag_weak)
9852 comdat_linkage (result);
9853 /* For WIN32 we also want to put explicit instantiations in
9854 linkonce sections. */
9855 else if (TREE_PUBLIC (result))
9856 maybe_make_one_only (result);
9859 if (TREE_CODE (result) == FUNCTION_DECL)
9863 /* Given two function templates PAT1 and PAT2, return:
9865 DEDUCE should be DEDUCE_EXACT or DEDUCE_ORDER.
9867 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
9868 -1 if PAT2 is more specialized than PAT1.
9869 0 if neither is more specialized.
9871 LEN is passed through to fn_type_unification. */
9874 more_specialized (tree pat1, tree pat2, int deduce, int len)
9879 /* If template argument deduction succeeds, we substitute the
9880 resulting arguments into non-deduced contexts. While doing that,
9881 we must be aware that we may encounter dependent types. */
9882 ++processing_template_decl;
9883 targs = get_bindings_real (pat1, DECL_TEMPLATE_RESULT (pat2),
9884 NULL_TREE, 0, deduce, len);
9888 targs = get_bindings_real (pat2, DECL_TEMPLATE_RESULT (pat1),
9889 NULL_TREE, 0, deduce, len);
9892 --processing_template_decl;
9897 /* Given two class template specialization list nodes PAT1 and PAT2, return:
9899 1 if PAT1 is more specialized than PAT2 as described in [temp.class.order].
9900 -1 if PAT2 is more specialized than PAT1.
9901 0 if neither is more specialized.
9903 FULL_ARGS is the full set of template arguments that triggers this
9904 partial ordering. */
9907 more_specialized_class (tree pat1, tree pat2, tree full_args)
9912 targs = get_class_bindings (TREE_VALUE (pat1), TREE_PURPOSE (pat1),
9913 add_outermost_template_args (full_args, TREE_PURPOSE (pat2)));
9917 targs = get_class_bindings (TREE_VALUE (pat2), TREE_PURPOSE (pat2),
9918 add_outermost_template_args (full_args, TREE_PURPOSE (pat1)));
9925 /* Return the template arguments that will produce the function signature
9926 DECL from the function template FN, with the explicit template
9927 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is 1, the return type must
9928 also match. Return NULL_TREE if no satisfactory arguments could be
9929 found. DEDUCE and LEN are passed through to fn_type_unification. */
9932 get_bindings_real (tree fn,
9939 int ntparms = DECL_NTPARMS (fn);
9940 tree targs = make_tree_vec (ntparms);
9942 tree decl_arg_types;
9945 /* Substitute the explicit template arguments into the type of DECL.
9946 The call to fn_type_unification will handle substitution into the
9948 decl_type = TREE_TYPE (decl);
9949 if (explicit_args && uses_template_parms (decl_type))
9952 tree converted_args;
9954 if (DECL_TEMPLATE_INFO (decl))
9955 tmpl = DECL_TI_TEMPLATE (decl);
9957 /* We can get here for some invalid specializations. */
9961 = (coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
9962 explicit_args, NULL_TREE,
9963 tf_none, /*require_all_arguments=*/0));
9964 if (converted_args == error_mark_node)
9967 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
9968 if (decl_type == error_mark_node)
9972 decl_arg_types = TYPE_ARG_TYPES (decl_type);
9973 /* Never do unification on the 'this' parameter. */
9974 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
9975 decl_arg_types = TREE_CHAIN (decl_arg_types);
9977 i = fn_type_unification (fn, explicit_args, targs,
9979 (check_rettype || DECL_CONV_FN_P (fn)
9980 ? TREE_TYPE (decl_type) : NULL_TREE),
9989 /* For most uses, we want to check the return type. */
9992 get_bindings (tree fn, tree decl, tree explicit_args)
9994 return get_bindings_real (fn, decl, explicit_args, 1, DEDUCE_EXACT, -1);
9997 /* But for resolve_overloaded_unification, we only care about the parameter
10001 get_bindings_overload (tree fn, tree decl, tree explicit_args)
10003 return get_bindings_real (fn, decl, explicit_args, 0, DEDUCE_EXACT, -1);
10006 /* Return the innermost template arguments that, when applied to a
10007 template specialization whose innermost template parameters are
10008 TPARMS, and whose specialization arguments are PARMS, yield the
10011 For example, suppose we have:
10013 template <class T, class U> struct S {};
10014 template <class T> struct S<T*, int> {};
10016 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
10017 {T}, the PARMS will be {T*, int} and the ARGS will be {double*,
10018 int}. The resulting vector will be {double}, indicating that `T'
10019 is bound to `double'. */
10022 get_class_bindings (tree tparms, tree parms, tree args)
10024 int i, ntparms = TREE_VEC_LENGTH (tparms);
10025 tree vec = make_tree_vec (ntparms);
10027 if (unify (tparms, vec, parms, INNERMOST_TEMPLATE_ARGS (args),
10031 for (i = 0; i < ntparms; ++i)
10032 if (! TREE_VEC_ELT (vec, i))
10035 if (verify_class_unification (vec, parms, args))
10041 /* In INSTANTIATIONS is a list of <INSTANTIATION, TEMPLATE> pairs.
10042 Pick the most specialized template, and return the corresponding
10043 instantiation, or if there is no corresponding instantiation, the
10044 template itself. If there is no most specialized template,
10045 error_mark_node is returned. If there are no templates at all,
10046 NULL_TREE is returned. */
10049 most_specialized_instantiation (tree instantiations)
10054 if (!instantiations)
10057 champ = instantiations;
10058 for (fn = TREE_CHAIN (instantiations); fn; fn = TREE_CHAIN (fn))
10060 fate = more_specialized (TREE_VALUE (champ), TREE_VALUE (fn),
10068 fn = TREE_CHAIN (fn);
10070 return error_mark_node;
10076 for (fn = instantiations; fn && fn != champ; fn = TREE_CHAIN (fn))
10078 fate = more_specialized (TREE_VALUE (champ), TREE_VALUE (fn),
10081 return error_mark_node;
10084 return TREE_PURPOSE (champ) ? TREE_PURPOSE (champ) : TREE_VALUE (champ);
10087 /* Return the most specialized of the list of templates in FNS that can
10088 produce an instantiation matching DECL, given the explicit template
10089 arguments EXPLICIT_ARGS. */
10092 most_specialized (tree fns, tree decl, tree explicit_args)
10094 tree candidates = NULL_TREE;
10097 for (fn = fns; fn; fn = TREE_CHAIN (fn))
10099 tree candidate = TREE_VALUE (fn);
10101 args = get_bindings (candidate, decl, explicit_args);
10103 candidates = tree_cons (NULL_TREE, candidate, candidates);
10106 return most_specialized_instantiation (candidates);
10109 /* If DECL is a specialization of some template, return the most
10110 general such template. Otherwise, returns NULL_TREE.
10112 For example, given:
10114 template <class T> struct S { template <class U> void f(U); };
10116 if TMPL is `template <class U> void S<int>::f(U)' this will return
10117 the full template. This function will not trace past partial
10118 specializations, however. For example, given in addition:
10120 template <class T> struct S<T*> { template <class U> void f(U); };
10122 if TMPL is `template <class U> void S<int*>::f(U)' this will return
10123 `template <class T> template <class U> S<T*>::f(U)'. */
10126 most_general_template (tree decl)
10128 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
10129 an immediate specialization. */
10130 if (TREE_CODE (decl) == FUNCTION_DECL)
10132 if (DECL_TEMPLATE_INFO (decl)) {
10133 decl = DECL_TI_TEMPLATE (decl);
10135 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
10136 template friend. */
10137 if (TREE_CODE (decl) != TEMPLATE_DECL)
10143 /* Look for more and more general templates. */
10144 while (DECL_TEMPLATE_INFO (decl))
10146 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
10147 (See cp-tree.h for details.) */
10148 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
10151 if (CLASS_TYPE_P (TREE_TYPE (decl))
10152 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
10155 /* Stop if we run into an explicitly specialized class template. */
10156 if (!DECL_NAMESPACE_SCOPE_P (decl)
10157 && DECL_CONTEXT (decl)
10158 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
10161 decl = DECL_TI_TEMPLATE (decl);
10167 /* Return the most specialized of the class template specializations
10168 of TMPL which can produce an instantiation matching ARGS, or
10169 error_mark_node if the choice is ambiguous. */
10172 most_specialized_class (tree tmpl, tree args)
10174 tree list = NULL_TREE;
10179 tmpl = most_general_template (tmpl);
10180 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
10183 = get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t), args);
10186 list = tree_cons (TREE_PURPOSE (t), TREE_VALUE (t), list);
10187 TREE_TYPE (list) = TREE_TYPE (t);
10196 t = TREE_CHAIN (t);
10197 for (; t; t = TREE_CHAIN (t))
10199 fate = more_specialized_class (champ, t, args);
10206 t = TREE_CHAIN (t);
10208 return error_mark_node;
10214 for (t = list; t && t != champ; t = TREE_CHAIN (t))
10216 fate = more_specialized_class (champ, t, args);
10218 return error_mark_node;
10224 /* Explicitly instantiate DECL. */
10227 do_decl_instantiation (tree decl, tree storage)
10229 tree result = NULL_TREE;
10233 /* An error occurred, for which grokdeclarator has already issued
10234 an appropriate message. */
10236 else if (! DECL_LANG_SPECIFIC (decl))
10238 error ("explicit instantiation of non-template `%#D'", decl);
10241 else if (TREE_CODE (decl) == VAR_DECL)
10243 /* There is an asymmetry here in the way VAR_DECLs and
10244 FUNCTION_DECLs are handled by grokdeclarator. In the case of
10245 the latter, the DECL we get back will be marked as a
10246 template instantiation, and the appropriate
10247 DECL_TEMPLATE_INFO will be set up. This does not happen for
10248 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
10249 should handle VAR_DECLs as it currently handles
10251 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
10252 if (!result || TREE_CODE (result) != VAR_DECL)
10254 error ("no matching template for `%D' found", decl);
10258 else if (TREE_CODE (decl) != FUNCTION_DECL)
10260 error ("explicit instantiation of `%#D'", decl);
10266 /* Check for various error cases. Note that if the explicit
10267 instantiation is valid the RESULT will currently be marked as an
10268 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
10269 until we get here. */
10271 if (DECL_TEMPLATE_SPECIALIZATION (result))
10273 /* DR 259 [temp.spec].
10275 Both an explicit instantiation and a declaration of an explicit
10276 specialization shall not appear in a program unless the explicit
10277 instantiation follows a declaration of the explicit specialization.
10279 For a given set of template parameters, if an explicit
10280 instantiation of a template appears after a declaration of an
10281 explicit specialization for that template, the explicit
10282 instantiation has no effect. */
10285 else if (DECL_EXPLICIT_INSTANTIATION (result))
10289 No program shall explicitly instantiate any template more
10292 We check DECL_INTERFACE_KNOWN so as not to complain when the first
10293 instantiation was `extern' and the second is not, and EXTERN_P for
10294 the opposite case. If -frepo, chances are we already got marked
10295 as an explicit instantiation because of the repo file. */
10296 if (DECL_INTERFACE_KNOWN (result) && !extern_p && !flag_use_repository)
10297 pedwarn ("duplicate explicit instantiation of `%#D'", result);
10299 /* If we've already instantiated the template, just return now. */
10300 if (DECL_INTERFACE_KNOWN (result))
10303 else if (!DECL_IMPLICIT_INSTANTIATION (result))
10305 error ("no matching template for `%D' found", result);
10308 else if (!DECL_TEMPLATE_INFO (result))
10310 pedwarn ("explicit instantiation of non-template `%#D'", result);
10314 if (flag_external_templates)
10317 if (storage == NULL_TREE)
10319 else if (storage == ridpointers[(int) RID_EXTERN])
10321 if (pedantic && !in_system_header)
10322 pedwarn ("ISO C++ forbids the use of `extern' on explicit instantiations");
10326 error ("storage class `%D' applied to template instantiation",
10329 SET_DECL_EXPLICIT_INSTANTIATION (result);
10330 mark_decl_instantiated (result, extern_p);
10331 repo_template_instantiated (result, extern_p);
10333 instantiate_decl (result, /*defer_ok=*/1);
10337 mark_class_instantiated (tree t, int extern_p)
10339 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
10340 SET_CLASSTYPE_INTERFACE_KNOWN (t);
10341 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
10342 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
10345 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
10346 rest_of_type_compilation (t, 1);
10350 /* Called from do_type_instantiation through binding_table_foreach to
10351 do recursive instantiation for the type bound in ENTRY. */
10353 bt_instantiate_type_proc (binding_entry entry, void *data)
10355 tree storage = *(tree *) data;
10357 if (IS_AGGR_TYPE (entry->type)
10358 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
10359 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
10362 /* Perform an explicit instantiation of template class T. STORAGE, if
10363 non-null, is the RID for extern, inline or static. COMPLAIN is
10364 nonzero if this is called from the parser, zero if called recursively,
10365 since the standard is unclear (as detailed below). */
10368 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
10374 if (TREE_CODE (t) == TYPE_DECL)
10377 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
10379 error ("explicit instantiation of non-template type `%T'", t);
10385 /* With -fexternal-templates, explicit instantiations are treated the same
10386 as implicit ones. */
10387 if (flag_external_templates)
10390 if (!COMPLETE_TYPE_P (t))
10392 if (complain & tf_error)
10393 error ("explicit instantiation of `%#T' before definition of template",
10398 if (storage != NULL_TREE)
10400 if (pedantic && !in_system_header)
10401 pedwarn("ISO C++ forbids the use of `%s' on explicit instantiations",
10402 IDENTIFIER_POINTER (storage));
10404 if (storage == ridpointers[(int) RID_INLINE])
10406 else if (storage == ridpointers[(int) RID_EXTERN])
10408 else if (storage == ridpointers[(int) RID_STATIC])
10412 error ("storage class `%D' applied to template instantiation",
10418 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
10420 /* DR 259 [temp.spec].
10422 Both an explicit instantiation and a declaration of an explicit
10423 specialization shall not appear in a program unless the explicit
10424 instantiation follows a declaration of the explicit specialization.
10426 For a given set of template parameters, if an explicit
10427 instantiation of a template appears after a declaration of an
10428 explicit specialization for that template, the explicit
10429 instantiation has no effect. */
10432 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
10436 No program shall explicitly instantiate any template more
10439 If CLASSTYPE_INTERFACE_ONLY, then the first explicit instantiation
10440 was `extern'. If EXTERN_P then the second is. If -frepo, chances
10441 are we already got marked as an explicit instantiation because of the
10442 repo file. All these cases are OK. */
10443 if (!CLASSTYPE_INTERFACE_ONLY (t) && !extern_p && !flag_use_repository
10444 && (complain & tf_error))
10445 pedwarn ("duplicate explicit instantiation of `%#T'", t);
10447 /* If we've already instantiated the template, just return now. */
10448 if (!CLASSTYPE_INTERFACE_ONLY (t))
10452 mark_class_instantiated (t, extern_p);
10453 repo_template_instantiated (t, extern_p);
10461 /* In contrast to implicit instantiation, where only the
10462 declarations, and not the definitions, of members are
10463 instantiated, we have here:
10467 The explicit instantiation of a class template specialization
10468 implies the instantiation of all of its members not
10469 previously explicitly specialized in the translation unit
10470 containing the explicit instantiation.
10472 Of course, we can't instantiate member template classes, since
10473 we don't have any arguments for them. Note that the standard
10474 is unclear on whether the instantiation of the members are
10475 *explicit* instantiations or not. We choose to be generous,
10476 and not set DECL_EXPLICIT_INSTANTIATION. Therefore, we allow
10477 the explicit instantiation of a class where some of the members
10478 have no definition in the current translation unit. */
10481 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
10482 if (TREE_CODE (tmp) == FUNCTION_DECL
10483 && DECL_TEMPLATE_INSTANTIATION (tmp))
10485 mark_decl_instantiated (tmp, extern_p);
10486 repo_template_instantiated (tmp, extern_p);
10488 instantiate_decl (tmp, /*defer_ok=*/1);
10491 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
10492 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
10494 mark_decl_instantiated (tmp, extern_p);
10495 repo_template_instantiated (tmp, extern_p);
10497 instantiate_decl (tmp, /*defer_ok=*/1);
10500 if (CLASSTYPE_NESTED_UTDS (t))
10501 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
10502 bt_instantiate_type_proc, &storage);
10506 /* Given a function DECL, which is a specialization of TMPL, modify
10507 DECL to be a re-instantiation of TMPL with the same template
10508 arguments. TMPL should be the template into which tsubst'ing
10509 should occur for DECL, not the most general template.
10511 One reason for doing this is a scenario like this:
10514 void f(const T&, int i);
10516 void g() { f(3, 7); }
10519 void f(const T& t, const int i) { }
10521 Note that when the template is first instantiated, with
10522 instantiate_template, the resulting DECL will have no name for the
10523 first parameter, and the wrong type for the second. So, when we go
10524 to instantiate the DECL, we regenerate it. */
10527 regenerate_decl_from_template (tree decl, tree tmpl)
10529 /* The most general version of TMPL. */
10531 /* The arguments used to instantiate DECL, from the most general
10538 args = DECL_TI_ARGS (decl);
10539 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
10541 /* Unregister the specialization so that when we tsubst we will not
10542 just return DECL. We don't have to unregister DECL from TMPL
10543 because if would only be registered there if it were a partial
10544 instantiation of a specialization, which it isn't: it's a full
10546 gen_tmpl = most_general_template (tmpl);
10547 unregistered = reregister_specialization (decl, gen_tmpl,
10548 /*new_spec=*/NULL_TREE);
10550 /* If the DECL was not unregistered then something peculiar is
10551 happening: we created a specialization but did not call
10552 register_specialization for it. */
10553 my_friendly_assert (unregistered, 0);
10555 /* Make sure that we can see identifiers, and compute access
10557 push_access_scope (decl);
10559 /* Do the substitution to get the new declaration. */
10560 new_decl = tsubst (code_pattern, args, tf_error, NULL_TREE);
10562 if (TREE_CODE (decl) == VAR_DECL)
10564 /* Set up DECL_INITIAL, since tsubst doesn't. */
10565 if (!DECL_INITIALIZED_IN_CLASS_P (decl))
10566 DECL_INITIAL (new_decl) =
10567 tsubst_expr (DECL_INITIAL (code_pattern), args,
10568 tf_error, DECL_TI_TEMPLATE (decl));
10570 else if (TREE_CODE (decl) == FUNCTION_DECL)
10572 /* Convince duplicate_decls to use the DECL_ARGUMENTS from the
10574 DECL_INITIAL (new_decl) = error_mark_node;
10575 /* And don't complain about a duplicate definition. */
10576 DECL_INITIAL (decl) = NULL_TREE;
10579 pop_access_scope (decl);
10581 /* The immediate parent of the new template is still whatever it was
10582 before, even though tsubst sets DECL_TI_TEMPLATE up as the most
10583 general template. We also reset the DECL_ASSEMBLER_NAME since
10584 tsubst always calculates the name as if the function in question
10585 were really a template instance, and sometimes, with friend
10586 functions, this is not so. See tsubst_friend_function for
10588 DECL_TI_TEMPLATE (new_decl) = DECL_TI_TEMPLATE (decl);
10589 COPY_DECL_ASSEMBLER_NAME (decl, new_decl);
10590 COPY_DECL_RTL (decl, new_decl);
10591 DECL_USE_TEMPLATE (new_decl) = DECL_USE_TEMPLATE (decl);
10593 /* Call duplicate decls to merge the old and new declarations. */
10594 duplicate_decls (new_decl, decl);
10596 /* Now, re-register the specialization. */
10597 register_specialization (decl, gen_tmpl, args);
10600 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
10601 substituted to get DECL. */
10604 template_for_substitution (tree decl)
10606 tree tmpl = DECL_TI_TEMPLATE (decl);
10608 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
10609 for the instantiation. This is not always the most general
10610 template. Consider, for example:
10613 struct S { template <class U> void f();
10614 template <> void f<int>(); };
10616 and an instantiation of S<double>::f<int>. We want TD to be the
10617 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
10618 while (/* An instantiation cannot have a definition, so we need a
10619 more general template. */
10620 DECL_TEMPLATE_INSTANTIATION (tmpl)
10621 /* We must also deal with friend templates. Given:
10623 template <class T> struct S {
10624 template <class U> friend void f() {};
10627 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
10628 so far as the language is concerned, but that's still
10629 where we get the pattern for the instantiation from. On
10630 other hand, if the definition comes outside the class, say:
10632 template <class T> struct S {
10633 template <class U> friend void f();
10635 template <class U> friend void f() {}
10637 we don't need to look any further. That's what the check for
10638 DECL_INITIAL is for. */
10639 || (TREE_CODE (decl) == FUNCTION_DECL
10640 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
10641 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
10643 /* The present template, TD, should not be a definition. If it
10644 were a definition, we should be using it! Note that we
10645 cannot restructure the loop to just keep going until we find
10646 a template with a definition, since that might go too far if
10647 a specialization was declared, but not defined. */
10648 my_friendly_assert (!(TREE_CODE (decl) == VAR_DECL
10649 && !DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl))),
10652 /* Fetch the more general template. */
10653 tmpl = DECL_TI_TEMPLATE (tmpl);
10659 /* Produce the definition of D, a _DECL generated from a template. If
10660 DEFER_OK is nonzero, then we don't have to actually do the
10661 instantiation now; we just have to do it sometime. */
10664 instantiate_decl (tree d, int defer_ok)
10666 tree tmpl = DECL_TI_TEMPLATE (d);
10673 int pattern_defined;
10675 location_t saved_loc = input_location;
10677 /* This function should only be used to instantiate templates for
10678 functions and static member variables. */
10679 my_friendly_assert (TREE_CODE (d) == FUNCTION_DECL
10680 || TREE_CODE (d) == VAR_DECL, 0);
10682 /* Variables are never deferred; if instantiation is required, they
10683 are instantiated right away. That allows for better code in the
10684 case that an expression refers to the value of the variable --
10685 if the variable has a constant value the referring expression can
10686 take advantage of that fact. */
10687 if (TREE_CODE (d) == VAR_DECL)
10690 /* Don't instantiate cloned functions. Instead, instantiate the
10691 functions they cloned. */
10692 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
10693 d = DECL_CLONED_FUNCTION (d);
10695 if (DECL_TEMPLATE_INSTANTIATED (d))
10696 /* D has already been instantiated. It might seem reasonable to
10697 check whether or not D is an explicit instantiation, and, if so,
10698 stop here. But when an explicit instantiation is deferred
10699 until the end of the compilation, DECL_EXPLICIT_INSTANTIATION
10700 is set, even though we still need to do the instantiation. */
10703 /* If we already have a specialization of this declaration, then
10704 there's no reason to instantiate it. Note that
10705 retrieve_specialization gives us both instantiations and
10706 specializations, so we must explicitly check
10707 DECL_TEMPLATE_SPECIALIZATION. */
10708 gen_tmpl = most_general_template (tmpl);
10709 gen_args = DECL_TI_ARGS (d);
10710 spec = retrieve_specialization (gen_tmpl, gen_args);
10711 if (spec != NULL_TREE && DECL_TEMPLATE_SPECIALIZATION (spec))
10714 /* This needs to happen before any tsubsting. */
10715 if (! push_tinst_level (d))
10718 timevar_push (TV_PARSE);
10720 /* We may be in the middle of deferred access check. Disable
10722 push_deferring_access_checks (dk_no_deferred);
10724 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
10725 for the instantiation. */
10726 td = template_for_substitution (d);
10727 code_pattern = DECL_TEMPLATE_RESULT (td);
10729 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
10730 || DECL_TEMPLATE_SPECIALIZATION (td))
10731 /* In the case of a friend template whose definition is provided
10732 outside the class, we may have too many arguments. Drop the
10733 ones we don't need. The same is true for specializations. */
10734 args = get_innermost_template_args
10735 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
10739 if (TREE_CODE (d) == FUNCTION_DECL)
10740 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
10742 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
10744 input_location = DECL_SOURCE_LOCATION (d);
10746 if (pattern_defined)
10748 /* Let the repository code that this template definition is
10751 The repository doesn't need to know about cloned functions
10752 because they never actually show up in the object file. It
10753 does need to know about the clones; those are the symbols
10754 that the linker will be emitting error messages about. */
10755 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (d)
10756 || DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (d))
10760 for (t = TREE_CHAIN (d);
10761 t && DECL_CLONED_FUNCTION_P (t);
10762 t = TREE_CHAIN (t))
10763 repo_template_used (t);
10766 repo_template_used (d);
10768 if (flag_external_templates && ! DECL_INTERFACE_KNOWN (d))
10770 if (flag_alt_external_templates)
10772 if (interface_unknown)
10773 warn_if_unknown_interface (d);
10775 else if (DECL_INTERFACE_KNOWN (code_pattern))
10777 DECL_INTERFACE_KNOWN (d) = 1;
10778 DECL_NOT_REALLY_EXTERN (d) = ! DECL_EXTERNAL (code_pattern);
10781 warn_if_unknown_interface (code_pattern);
10785 import_export_decl (d);
10790 /* Recheck the substitutions to obtain any warning messages
10791 about ignoring cv qualifiers. */
10792 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
10793 tree type = TREE_TYPE (gen);
10795 /* Make sure that we can see identifiers, and compute access
10796 correctly. D is already the target FUNCTION_DECL with the
10798 push_access_scope (d);
10800 if (TREE_CODE (gen) == FUNCTION_DECL)
10802 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_error | tf_warning, d);
10803 tsubst (TYPE_RAISES_EXCEPTIONS (type), gen_args,
10804 tf_error | tf_warning, d);
10805 /* Don't simply tsubst the function type, as that will give
10806 duplicate warnings about poor parameter qualifications.
10807 The function arguments are the same as the decl_arguments
10808 without the top level cv qualifiers. */
10809 type = TREE_TYPE (type);
10811 tsubst (type, gen_args, tf_error | tf_warning, d);
10813 pop_access_scope (d);
10816 if (TREE_CODE (d) == VAR_DECL && DECL_INITIALIZED_IN_CLASS_P (d)
10817 && DECL_INITIAL (d) == NULL_TREE)
10818 /* We should have set up DECL_INITIAL in instantiate_class_template. */
10820 /* Reject all external templates except inline functions. */
10821 else if (DECL_INTERFACE_KNOWN (d)
10822 && ! DECL_NOT_REALLY_EXTERN (d)
10823 && ! (TREE_CODE (d) == FUNCTION_DECL
10824 && DECL_INLINE (d)))
10826 /* Defer all other templates, unless we have been explicitly
10827 forbidden from doing so. We restore the source position here
10828 because it's used by add_pending_template. */
10829 else if (! pattern_defined || defer_ok)
10831 input_location = saved_loc;
10833 if (at_eof && !pattern_defined
10834 && DECL_EXPLICIT_INSTANTIATION (d))
10837 The definition of a non-exported function template, a
10838 non-exported member function template, or a non-exported
10839 member function or static data member of a class template
10840 shall be present in every translation unit in which it is
10841 explicitly instantiated. */
10843 ("explicit instantiation of `%D' but no definition available", d);
10845 add_pending_template (d);
10849 need_push = !global_bindings_p ();
10851 push_to_top_level ();
10853 /* Regenerate the declaration in case the template has been modified
10854 by a subsequent redeclaration. */
10855 regenerate_decl_from_template (d, td);
10857 /* We already set the file and line above. Reset them now in case
10858 they changed as a result of calling
10859 regenerate_decl_from_template. */
10860 input_location = DECL_SOURCE_LOCATION (d);
10862 if (TREE_CODE (d) == VAR_DECL)
10864 /* Clear out DECL_RTL; whatever was there before may not be right
10865 since we've reset the type of the declaration. */
10866 SET_DECL_RTL (d, NULL_RTX);
10868 DECL_IN_AGGR_P (d) = 0;
10869 import_export_decl (d);
10870 DECL_EXTERNAL (d) = ! DECL_NOT_REALLY_EXTERN (d);
10872 if (DECL_EXTERNAL (d))
10874 /* The fact that this code is executing indicates that:
10876 (1) D is a template static data member, for which a
10877 definition is available.
10879 (2) An implicit or explicit instantiation has occurred.
10881 (3) We are not going to emit a definition of the static
10882 data member at this time.
10884 This situation is peculiar, but it occurs on platforms
10885 without weak symbols when performing an implicit
10886 instantiation. There, we cannot implicitly instantiate a
10887 defined static data member in more than one translation
10888 unit, so import_export_decl marks the declaration as
10889 external; we must rely on explicit instantiation. */
10893 /* Mark D as instantiated so that recursive calls to
10894 instantiate_decl do not try to instantiate it again. */
10895 DECL_TEMPLATE_INSTANTIATED (d) = 1;
10897 (!DECL_INITIALIZED_IN_CLASS_P (d)
10898 ? DECL_INITIAL (d) : NULL_TREE),
10902 else if (TREE_CODE (d) == FUNCTION_DECL)
10904 htab_t saved_local_specializations;
10909 /* Mark D as instantiated so that recursive calls to
10910 instantiate_decl do not try to instantiate it again. */
10911 DECL_TEMPLATE_INSTANTIATED (d) = 1;
10913 /* Save away the current list, in case we are instantiating one
10914 template from within the body of another. */
10915 saved_local_specializations = local_specializations;
10917 /* Set up the list of local specializations. */
10918 local_specializations = htab_create (37,
10919 hash_local_specialization,
10920 eq_local_specializations,
10923 /* Set up context. */
10924 import_export_decl (d);
10925 start_function (NULL_TREE, d, NULL_TREE, SF_PRE_PARSED);
10927 /* Create substitution entries for the parameters. */
10928 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
10929 tmpl_parm = DECL_ARGUMENTS (subst_decl);
10930 spec_parm = DECL_ARGUMENTS (d);
10931 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
10933 register_local_specialization (spec_parm, tmpl_parm);
10934 spec_parm = skip_artificial_parms_for (d, spec_parm);
10935 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
10939 register_local_specialization (spec_parm, tmpl_parm);
10940 tmpl_parm = TREE_CHAIN (tmpl_parm);
10941 spec_parm = TREE_CHAIN (spec_parm);
10943 my_friendly_assert (!spec_parm, 20020813);
10945 /* Substitute into the body of the function. */
10946 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
10947 tf_error | tf_warning, tmpl);
10949 /* We don't need the local specializations any more. */
10950 htab_delete (local_specializations);
10951 local_specializations = saved_local_specializations;
10953 /* Finish the function. */
10954 d = finish_function (0);
10955 expand_or_defer_fn (d);
10958 /* We're not deferring instantiation any more. */
10959 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
10962 pop_from_top_level ();
10965 input_location = saved_loc;
10966 pop_deferring_access_checks ();
10967 pop_tinst_level ();
10969 timevar_pop (TV_PARSE);
10974 /* Run through the list of templates that we wish we could
10975 instantiate, and instantiate any we can. */
10978 instantiate_pending_templates (void)
10981 tree last = NULL_TREE;
10982 int instantiated_something = 0;
10989 t = &pending_templates;
10992 tree instantiation = TREE_VALUE (*t);
10994 reopen_tinst_level (TREE_PURPOSE (*t));
10996 if (TYPE_P (instantiation))
11000 if (!COMPLETE_TYPE_P (instantiation))
11002 instantiate_class_template (instantiation);
11003 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
11004 for (fn = TYPE_METHODS (instantiation);
11006 fn = TREE_CHAIN (fn))
11007 if (! DECL_ARTIFICIAL (fn))
11008 instantiate_decl (fn, /*defer_ok=*/0);
11009 if (COMPLETE_TYPE_P (instantiation))
11011 instantiated_something = 1;
11016 if (COMPLETE_TYPE_P (instantiation))
11017 /* If INSTANTIATION has been instantiated, then we don't
11018 need to consider it again in the future. */
11019 *t = TREE_CHAIN (*t);
11023 t = &TREE_CHAIN (*t);
11028 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
11029 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
11031 instantiation = instantiate_decl (instantiation,
11033 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
11035 instantiated_something = 1;
11040 if (DECL_TEMPLATE_SPECIALIZATION (instantiation)
11041 || DECL_TEMPLATE_INSTANTIATED (instantiation))
11042 /* If INSTANTIATION has been instantiated, then we don't
11043 need to consider it again in the future. */
11044 *t = TREE_CHAIN (*t);
11048 t = &TREE_CHAIN (*t);
11052 current_tinst_level = NULL_TREE;
11054 last_pending_template = last;
11056 while (reconsider);
11058 return instantiated_something;
11061 /* Substitute ARGVEC into T, which is a list of initializers for
11062 either base class or a non-static data member. The TREE_PURPOSEs
11063 are DECLs, and the TREE_VALUEs are the initializer values. Used by
11064 instantiate_decl. */
11067 tsubst_initializer_list (tree t, tree argvec)
11069 tree inits = NULL_TREE;
11071 for (; t; t = TREE_CHAIN (t))
11077 decl = tsubst_copy (TREE_PURPOSE (t), argvec, tf_error | tf_warning,
11079 decl = expand_member_init (decl);
11080 if (decl && !DECL_P (decl))
11081 in_base_initializer = 1;
11083 init = tsubst_expr (TREE_VALUE (t), argvec, tf_error | tf_warning,
11087 else if (TREE_CODE (init) == TREE_LIST)
11088 for (val = init; val; val = TREE_CHAIN (val))
11089 TREE_VALUE (val) = convert_from_reference (TREE_VALUE (val));
11090 else if (init != void_type_node)
11091 init = convert_from_reference (init);
11093 in_base_initializer = 0;
11097 init = build_tree_list (decl, init);
11098 TREE_CHAIN (init) = inits;
11105 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
11108 set_current_access_from_decl (tree decl)
11110 if (TREE_PRIVATE (decl))
11111 current_access_specifier = access_private_node;
11112 else if (TREE_PROTECTED (decl))
11113 current_access_specifier = access_protected_node;
11115 current_access_specifier = access_public_node;
11118 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
11119 is the instantiation (which should have been created with
11120 start_enum) and ARGS are the template arguments to use. */
11123 tsubst_enum (tree tag, tree newtag, tree args)
11127 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
11132 decl = TREE_VALUE (e);
11133 /* Note that in a template enum, the TREE_VALUE is the
11134 CONST_DECL, not the corresponding INTEGER_CST. */
11135 value = tsubst_expr (DECL_INITIAL (decl),
11136 args, tf_error | tf_warning,
11139 /* Give this enumeration constant the correct access. */
11140 set_current_access_from_decl (decl);
11142 /* Actually build the enumerator itself. */
11143 build_enumerator (DECL_NAME (decl), value, newtag);
11146 finish_enum (newtag);
11147 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
11148 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
11151 /* DECL is a FUNCTION_DECL that is a template specialization. Return
11152 its type -- but without substituting the innermost set of template
11153 arguments. So, innermost set of template parameters will appear in
11157 get_mostly_instantiated_function_type (tree decl)
11165 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11166 targs = DECL_TI_ARGS (decl);
11167 tparms = DECL_TEMPLATE_PARMS (tmpl);
11168 parm_depth = TMPL_PARMS_DEPTH (tparms);
11170 /* There should be as many levels of arguments as there are levels
11172 my_friendly_assert (parm_depth == TMPL_ARGS_DEPTH (targs), 0);
11174 fn_type = TREE_TYPE (tmpl);
11176 if (parm_depth == 1)
11177 /* No substitution is necessary. */
11184 /* Replace the innermost level of the TARGS with NULL_TREEs to
11185 let tsubst know not to substitute for those parameters. */
11186 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
11187 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
11188 SET_TMPL_ARGS_LEVEL (partial_args, i,
11189 TMPL_ARGS_LEVEL (targs, i));
11190 SET_TMPL_ARGS_LEVEL (partial_args,
11191 TMPL_ARGS_DEPTH (targs),
11192 make_tree_vec (DECL_NTPARMS (tmpl)));
11194 /* Make sure that we can see identifiers, and compute access
11195 correctly. We can just use the context of DECL for the
11196 partial substitution here. It depends only on outer template
11197 parameters, regardless of whether the innermost level is
11198 specialized or not. */
11199 push_access_scope (decl);
11201 /* Now, do the (partial) substitution to figure out the
11202 appropriate function type. */
11203 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
11205 /* Substitute into the template parameters to obtain the real
11206 innermost set of parameters. This step is important if the
11207 innermost set of template parameters contains value
11208 parameters whose types depend on outer template parameters. */
11209 TREE_VEC_LENGTH (partial_args)--;
11210 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
11212 pop_access_scope (decl);
11218 /* Return truthvalue if we're processing a template different from
11219 the last one involved in diagnostics. */
11221 problematic_instantiation_changed (void)
11223 return last_template_error_tick != tinst_level_tick;
11226 /* Remember current template involved in diagnostics. */
11228 record_last_problematic_instantiation (void)
11230 last_template_error_tick = tinst_level_tick;
11234 current_instantiation (void)
11236 return current_tinst_level;
11239 /* [temp.param] Check that template non-type parm TYPE is of an allowable
11240 type. Return zero for ok, nonzero for disallowed. Issue error and
11241 warning messages under control of COMPLAIN. */
11244 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
11246 if (INTEGRAL_TYPE_P (type))
11248 else if (POINTER_TYPE_P (type))
11250 else if (TYPE_PTR_TO_MEMBER_P (type))
11252 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
11254 else if (TREE_CODE (type) == TYPENAME_TYPE)
11257 if (complain & tf_error)
11258 error ("`%#T' is not a valid type for a template constant parameter",
11263 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
11264 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
11267 dependent_type_p_r (tree type)
11273 A type is dependent if it is:
11275 -- a template parameter. */
11276 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
11278 /* -- a qualified-id with a nested-name-specifier which contains a
11279 class-name that names a dependent type or whose unqualified-id
11280 names a dependent type. */
11281 if (TREE_CODE (type) == TYPENAME_TYPE)
11283 /* -- a cv-qualified type where the cv-unqualified type is
11285 type = TYPE_MAIN_VARIANT (type);
11286 /* -- a compound type constructed from any dependent type. */
11287 if (TYPE_PTR_TO_MEMBER_P (type))
11288 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
11289 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
11291 else if (TREE_CODE (type) == POINTER_TYPE
11292 || TREE_CODE (type) == REFERENCE_TYPE)
11293 return dependent_type_p (TREE_TYPE (type));
11294 else if (TREE_CODE (type) == FUNCTION_TYPE
11295 || TREE_CODE (type) == METHOD_TYPE)
11299 if (dependent_type_p (TREE_TYPE (type)))
11301 for (arg_type = TYPE_ARG_TYPES (type);
11303 arg_type = TREE_CHAIN (arg_type))
11304 if (dependent_type_p (TREE_VALUE (arg_type)))
11308 /* -- an array type constructed from any dependent type or whose
11309 size is specified by a constant expression that is
11310 value-dependent. */
11311 if (TREE_CODE (type) == ARRAY_TYPE)
11313 if (TYPE_DOMAIN (type)
11314 && ((value_dependent_expression_p
11315 (TYPE_MAX_VALUE (TYPE_DOMAIN (type))))
11316 || (type_dependent_expression_p
11317 (TYPE_MAX_VALUE (TYPE_DOMAIN (type))))))
11319 return dependent_type_p (TREE_TYPE (type));
11322 /* -- a template-id in which either the template name is a template
11324 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
11326 /* ... or any of the template arguments is a dependent type or
11327 an expression that is type-dependent or value-dependent. */
11328 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
11329 && (any_dependent_template_arguments_p
11330 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
11333 /* All TYPEOF_TYPEs are dependent; if the argument of the `typeof'
11334 expression is not type-dependent, then it should already been
11336 if (TREE_CODE (type) == TYPEOF_TYPE)
11339 /* The standard does not specifically mention types that are local
11340 to template functions or local classes, but they should be
11341 considered dependent too. For example:
11343 template <int I> void f() {
11348 The size of `E' cannot be known until the value of `I' has been
11349 determined. Therefore, `E' must be considered dependent. */
11350 scope = TYPE_CONTEXT (type);
11351 if (scope && TYPE_P (scope))
11352 return dependent_type_p (scope);
11353 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
11354 return type_dependent_expression_p (scope);
11356 /* Other types are non-dependent. */
11360 /* Returns TRUE if TYPE is dependent, in the sense of
11361 [temp.dep.type]. */
11364 dependent_type_p (tree type)
11366 /* If there are no template parameters in scope, then there can't be
11367 any dependent types. */
11368 if (!processing_template_decl)
11371 /* If the type is NULL, we have not computed a type for the entity
11372 in question; in that case, the type is dependent. */
11376 /* Erroneous types can be considered non-dependent. */
11377 if (type == error_mark_node)
11380 /* If we have not already computed the appropriate value for TYPE,
11382 if (!TYPE_DEPENDENT_P_VALID (type))
11384 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
11385 TYPE_DEPENDENT_P_VALID (type) = 1;
11388 return TYPE_DEPENDENT_P (type);
11391 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
11394 dependent_scope_ref_p (tree expression, bool criterion (tree))
11399 my_friendly_assert (TREE_CODE (expression) == SCOPE_REF, 20030714);
11401 if (!TYPE_P (TREE_OPERAND (expression, 0)))
11404 scope = TREE_OPERAND (expression, 0);
11405 name = TREE_OPERAND (expression, 1);
11409 An id-expression is type-dependent if it contains a
11410 nested-name-specifier that contains a class-name that names a
11412 /* The suggested resolution to Core Issue 2 implies that if the
11413 qualifying type is the current class, then we must peek
11416 && currently_open_class (scope)
11417 && !criterion (name))
11419 if (dependent_type_p (scope))
11425 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
11426 [temp.dep.constexpr] */
11429 value_dependent_expression_p (tree expression)
11431 if (!processing_template_decl)
11434 /* A name declared with a dependent type. */
11435 if (TREE_CODE (expression) == IDENTIFIER_NODE
11436 || (DECL_P (expression)
11437 && type_dependent_expression_p (expression)))
11439 /* A non-type template parameter. */
11440 if ((TREE_CODE (expression) == CONST_DECL
11441 && DECL_TEMPLATE_PARM_P (expression))
11442 || TREE_CODE (expression) == TEMPLATE_PARM_INDEX)
11444 /* A constant with integral or enumeration type and is initialized
11445 with an expression that is value-dependent. */
11446 if (TREE_CODE (expression) == VAR_DECL
11447 && DECL_INITIAL (expression)
11448 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
11449 && value_dependent_expression_p (DECL_INITIAL (expression)))
11451 /* These expressions are value-dependent if the type to which the
11452 cast occurs is dependent or the expression being casted is
11453 value-dependent. */
11454 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
11455 || TREE_CODE (expression) == STATIC_CAST_EXPR
11456 || TREE_CODE (expression) == CONST_CAST_EXPR
11457 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
11458 || TREE_CODE (expression) == CAST_EXPR)
11460 if (dependent_type_p (TREE_TYPE (expression)))
11462 /* A functional cast has a list of operands. */
11463 expression = TREE_OPERAND (expression, 0);
11464 if (TREE_CODE (expression) == TREE_LIST)
11468 if (value_dependent_expression_p (TREE_VALUE (expression)))
11470 expression = TREE_CHAIN (expression);
11472 while (expression);
11476 return value_dependent_expression_p (expression);
11478 /* A `sizeof' expression is value-dependent if the operand is
11480 if (TREE_CODE (expression) == SIZEOF_EXPR
11481 || TREE_CODE (expression) == ALIGNOF_EXPR)
11483 expression = TREE_OPERAND (expression, 0);
11484 if (TYPE_P (expression))
11485 return dependent_type_p (expression);
11486 return type_dependent_expression_p (expression);
11488 if (TREE_CODE (expression) == SCOPE_REF)
11489 return dependent_scope_ref_p (expression, value_dependent_expression_p);
11490 /* A constant expression is value-dependent if any subexpression is
11491 value-dependent. */
11492 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (expression))))
11494 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
11497 return (value_dependent_expression_p
11498 (TREE_OPERAND (expression, 0)));
11501 return ((value_dependent_expression_p
11502 (TREE_OPERAND (expression, 0)))
11503 || (value_dependent_expression_p
11504 (TREE_OPERAND (expression, 1))));
11508 for (i = 0; i < first_rtl_op (TREE_CODE (expression)); ++i)
11509 /* In some cases, some of the operands may be missing.
11510 (For example, in the case of PREDECREMENT_EXPR, the
11511 amount to increment by may be missing.) That doesn't
11512 make the expression dependent. */
11513 if (TREE_OPERAND (expression, i)
11514 && (value_dependent_expression_p
11515 (TREE_OPERAND (expression, i))))
11522 /* The expression is not value-dependent. */
11526 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
11527 [temp.dep.expr]. */
11530 type_dependent_expression_p (tree expression)
11532 if (!processing_template_decl)
11535 if (expression == error_mark_node)
11538 /* An unresolved name is always dependent. */
11539 if (TREE_CODE (expression) == IDENTIFIER_NODE)
11542 /* Some expression forms are never type-dependent. */
11543 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
11544 || TREE_CODE (expression) == SIZEOF_EXPR
11545 || TREE_CODE (expression) == ALIGNOF_EXPR
11546 || TREE_CODE (expression) == TYPEID_EXPR
11547 || TREE_CODE (expression) == DELETE_EXPR
11548 || TREE_CODE (expression) == VEC_DELETE_EXPR
11549 || TREE_CODE (expression) == THROW_EXPR)
11552 /* The types of these expressions depends only on the type to which
11553 the cast occurs. */
11554 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
11555 || TREE_CODE (expression) == STATIC_CAST_EXPR
11556 || TREE_CODE (expression) == CONST_CAST_EXPR
11557 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
11558 || TREE_CODE (expression) == CAST_EXPR)
11559 return dependent_type_p (TREE_TYPE (expression));
11561 /* The types of these expressions depends only on the type created
11562 by the expression. */
11563 if (TREE_CODE (expression) == NEW_EXPR
11564 || TREE_CODE (expression) == VEC_NEW_EXPR)
11566 /* For NEW_EXPR tree nodes created inside a template, either
11567 the object type itself or a TREE_LIST may appear as the
11569 tree type = TREE_OPERAND (expression, 1);
11570 if (TREE_CODE (type) == TREE_LIST)
11571 /* This is an array type. We need to check array dimensions
11573 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
11574 || value_dependent_expression_p
11575 (TREE_OPERAND (TREE_VALUE (type), 1));
11577 return dependent_type_p (type);
11580 if (TREE_CODE (expression) == SCOPE_REF
11581 && dependent_scope_ref_p (expression,
11582 type_dependent_expression_p))
11585 if (TREE_CODE (expression) == FUNCTION_DECL
11586 && DECL_LANG_SPECIFIC (expression)
11587 && DECL_TEMPLATE_INFO (expression)
11588 && (any_dependent_template_arguments_p
11589 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
11592 if (TREE_TYPE (expression) == unknown_type_node)
11594 if (TREE_CODE (expression) == ADDR_EXPR)
11595 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
11596 if (TREE_CODE (expression) == COMPONENT_REF)
11598 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
11600 expression = TREE_OPERAND (expression, 1);
11601 if (TREE_CODE (expression) == IDENTIFIER_NODE)
11605 if (TREE_CODE (expression) == BASELINK)
11606 expression = BASELINK_FUNCTIONS (expression);
11607 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
11609 if (any_dependent_template_arguments_p
11610 (TREE_OPERAND (expression, 1)))
11612 expression = TREE_OPERAND (expression, 0);
11614 if (TREE_CODE (expression) == OVERLOAD)
11618 if (type_dependent_expression_p (OVL_CURRENT (expression)))
11620 expression = OVL_NEXT (expression);
11627 return (dependent_type_p (TREE_TYPE (expression)));
11630 /* Returns TRUE if ARGS (a TREE_LIST of arguments to a function call)
11631 contains a type-dependent expression. */
11634 any_type_dependent_arguments_p (tree args)
11638 tree arg = TREE_VALUE (args);
11640 if (type_dependent_expression_p (arg))
11642 args = TREE_CHAIN (args);
11647 /* Returns TRUE if the ARG (a template argument) is dependent. */
11650 dependent_template_arg_p (tree arg)
11652 if (!processing_template_decl)
11655 if (TREE_CODE (arg) == TEMPLATE_DECL
11656 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11657 return dependent_template_p (arg);
11658 else if (TYPE_P (arg))
11659 return dependent_type_p (arg);
11661 return (type_dependent_expression_p (arg)
11662 || value_dependent_expression_p (arg));
11665 /* Returns true if ARGS (a collection of template arguments) contains
11666 any dependent arguments. */
11669 any_dependent_template_arguments_p (tree args)
11676 for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
11677 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
11683 /* Returns TRUE if the template TMPL is dependent. */
11686 dependent_template_p (tree tmpl)
11688 /* Template template parameters are dependent. */
11689 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
11690 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
11692 /* So are qualified names that have not been looked up. */
11693 if (TREE_CODE (tmpl) == SCOPE_REF)
11695 /* So are member templates of dependent classes. */
11696 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
11697 return dependent_type_p (DECL_CONTEXT (tmpl));
11701 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
11704 dependent_template_id_p (tree tmpl, tree args)
11706 return (dependent_template_p (tmpl)
11707 || any_dependent_template_arguments_p (args));
11710 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
11711 TYPENAME_TYPE corresponds. Returns ERROR_MARK_NODE if no such TYPE
11712 can be found. Note that this function peers inside uninstantiated
11713 templates and therefore should be used only in extremely limited
11717 resolve_typename_type (tree type, bool only_current_p)
11724 my_friendly_assert (TREE_CODE (type) == TYPENAME_TYPE,
11727 scope = TYPE_CONTEXT (type);
11728 name = TYPE_IDENTIFIER (type);
11730 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
11731 it first before we can figure out what NAME refers to. */
11732 if (TREE_CODE (scope) == TYPENAME_TYPE)
11733 scope = resolve_typename_type (scope, only_current_p);
11734 /* If we don't know what SCOPE refers to, then we cannot resolve the
11736 if (scope == error_mark_node || TREE_CODE (scope) == TYPENAME_TYPE)
11737 return error_mark_node;
11738 /* If the SCOPE is a template type parameter, we have no way of
11739 resolving the name. */
11740 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
11742 /* If the SCOPE is not the current instantiation, there's no reason
11743 to look inside it. */
11744 if (only_current_p && !currently_open_class (scope))
11745 return error_mark_node;
11746 /* If SCOPE is a partial instantiation, it will not have a valid
11747 TYPE_FIELDS list, so use the original template. */
11748 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
11749 /* Enter the SCOPE so that name lookup will be resolved as if we
11750 were in the class definition. In particular, SCOPE will no
11751 longer be considered a dependent type. */
11752 push_scope (scope);
11753 /* Look up the declaration. */
11754 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
11755 /* Obtain the set of qualifiers applied to the TYPE. */
11756 quals = cp_type_quals (type);
11757 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
11758 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
11760 type = error_mark_node;
11761 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
11762 && TREE_CODE (decl) == TYPE_DECL)
11763 type = TREE_TYPE (decl);
11764 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
11765 && DECL_CLASS_TEMPLATE_P (decl))
11769 /* Obtain the template and the arguments. */
11770 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
11771 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
11772 /* Instantiate the template. */
11773 type = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
11774 /*entering_scope=*/0, tf_error | tf_user);
11777 type = error_mark_node;
11778 /* Qualify the resulting type. */
11779 if (type != error_mark_node && quals)
11780 type = cp_build_qualified_type (type, quals);
11781 /* Leave the SCOPE. */
11787 /* EXPR is an expression which is not type-dependent. Return a proxy
11788 for EXPR that can be used to compute the types of larger
11789 expressions containing EXPR. */
11792 build_non_dependent_expr (tree expr)
11794 /* Preserve null pointer constants so that the type of things like
11795 "p == 0" where "p" is a pointer can be determined. */
11796 if (null_ptr_cst_p (expr))
11798 /* Preserve OVERLOADs; the functions must be available to resolve
11800 if (TREE_CODE (expr) == OVERLOAD)
11802 /* Preserve string constants; conversions from string constants to
11803 "char *" are allowed, even though normally a "const char *"
11804 cannot be used to initialize a "char *". */
11805 if (TREE_CODE (expr) == STRING_CST)
11808 if (TREE_CODE (expr) == COND_EXPR)
11809 return build (COND_EXPR,
11811 TREE_OPERAND (expr, 0),
11812 build_non_dependent_expr (TREE_OPERAND (expr, 1)),
11813 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
11814 if (TREE_CODE (expr) == COMPOUND_EXPR)
11815 return build (COMPOUND_EXPR,
11817 TREE_OPERAND (expr, 0),
11818 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
11820 /* Otherwise, build a NON_DEPENDENT_EXPR.
11822 REFERENCE_TYPEs are not stripped for expressions in templates
11823 because doing so would play havoc with mangling. Consider, for
11826 template <typename T> void f<T& g>() { g(); }
11828 In the body of "f", the expression for "g" will have
11829 REFERENCE_TYPE, even though the standard says that it should
11830 not. The reason is that we must preserve the syntactic form of
11831 the expression so that mangling (say) "f<g>" inside the body of
11832 "f" works out correctly. Therefore, the REFERENCE_TYPE is
11834 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
11837 /* ARGS is a TREE_LIST of expressions as arguments to a function call.
11838 Return a new TREE_LIST with the various arguments replaced with
11839 equivalent non-dependent expressions. */
11842 build_non_dependent_args (tree args)
11847 new_args = NULL_TREE;
11848 for (a = args; a; a = TREE_CHAIN (a))
11849 new_args = tree_cons (NULL_TREE,
11850 build_non_dependent_expr (TREE_VALUE (a)),
11852 return nreverse (new_args);
11855 #include "gt-cp-pt.h"