1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000
3 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 GNU CC.
9 GNU CC 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 GNU CC 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 GNU CC; 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". */
47 /* The type of functions taking a tree, and some additional data, and
49 typedef int (*tree_fn_t) PARAMS ((tree, void*));
51 extern struct obstack permanent_obstack;
54 extern char *input_filename;
56 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
57 instantiations have been deferred, either because their definitions
58 were not yet available, or because we were putting off doing the
59 work. The TREE_PURPOSE of each entry is a SRCLOC indicating where
60 the instantiate request occurred; the TREE_VALUE is a either a DECL
61 (for a function or static data member), or a TYPE (for a class)
62 indicating what we are hoping to instantiate. */
63 static tree pending_templates;
64 static tree *template_tail = &pending_templates;
66 static tree maybe_templates;
67 static tree *maybe_template_tail = &maybe_templates;
69 int processing_template_parmlist;
70 static int template_header_count;
72 static tree saved_trees;
73 static varray_type inline_parm_levels;
74 static size_t inline_parm_levels_used;
76 #define obstack_chunk_alloc xmalloc
77 #define obstack_chunk_free free
79 #define UNIFY_ALLOW_NONE 0
80 #define UNIFY_ALLOW_MORE_CV_QUAL 1
81 #define UNIFY_ALLOW_LESS_CV_QUAL 2
82 #define UNIFY_ALLOW_DERIVED 4
83 #define UNIFY_ALLOW_INTEGER 8
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 int resolve_overloaded_unification PARAMS ((tree, tree, tree, tree,
92 unification_kind_t, int));
93 static int try_one_overload PARAMS ((tree, tree, tree, tree, tree,
94 unification_kind_t, int));
95 static int unify PARAMS ((tree, tree, tree, tree, int));
96 static void add_pending_template PARAMS ((tree));
97 static int push_tinst_level PARAMS ((tree));
98 static tree classtype_mangled_name PARAMS ((tree));
99 static char *mangle_class_name_for_template PARAMS ((char *, tree, tree));
100 static tree tsubst_expr_values PARAMS ((tree, tree));
101 static int list_eq PARAMS ((tree, tree));
102 static tree get_class_bindings PARAMS ((tree, tree, tree));
103 static tree coerce_template_parms PARAMS ((tree, tree, tree, int, int));
104 static void tsubst_enum PARAMS ((tree, tree, tree));
105 static tree add_to_template_args PARAMS ((tree, tree));
106 static tree add_outermost_template_args PARAMS ((tree, tree));
107 static void maybe_adjust_types_for_deduction PARAMS ((unification_kind_t, tree*,
109 static int type_unification_real PARAMS ((tree, tree, tree, tree,
110 int, unification_kind_t, int));
111 static void note_template_header PARAMS ((int));
112 static tree maybe_fold_nontype_arg PARAMS ((tree));
113 static tree convert_nontype_argument PARAMS ((tree, tree));
114 static tree convert_template_argument PARAMS ((tree, tree, tree, int,
116 static tree get_bindings_overload PARAMS ((tree, tree, tree));
117 static int for_each_template_parm PARAMS ((tree, tree_fn_t, void*));
118 static tree build_template_parm_index PARAMS ((int, int, int, tree, tree));
119 static int inline_needs_template_parms PARAMS ((tree));
120 static void push_inline_template_parms_recursive PARAMS ((tree, int));
121 static tree retrieve_specialization PARAMS ((tree, tree));
122 static tree retrieve_local_specialization PARAMS ((tree, tree));
123 static tree register_specialization PARAMS ((tree, tree, tree));
124 static tree register_local_specialization PARAMS ((tree, tree, tree));
125 static int unregister_specialization PARAMS ((tree, tree));
126 static tree reduce_template_parm_level PARAMS ((tree, tree, int));
127 static tree build_template_decl PARAMS ((tree, tree));
128 static int mark_template_parm PARAMS ((tree, void *));
129 static tree tsubst_friend_function PARAMS ((tree, tree));
130 static tree tsubst_friend_class PARAMS ((tree, tree));
131 static tree get_bindings_real PARAMS ((tree, tree, tree, int));
132 static int template_decl_level PARAMS ((tree));
133 static tree maybe_get_template_decl_from_type_decl PARAMS ((tree));
134 static int check_cv_quals_for_unify PARAMS ((int, tree, tree));
135 static tree tsubst_template_arg_vector PARAMS ((tree, tree, int));
136 static tree tsubst_template_parms PARAMS ((tree, tree, int));
137 static void regenerate_decl_from_template PARAMS ((tree, tree));
138 static tree most_specialized PARAMS ((tree, tree, tree));
139 static tree most_specialized_class PARAMS ((tree, tree));
140 static void set_mangled_name_for_template_decl PARAMS ((tree));
141 static int template_class_depth_real PARAMS ((tree, int));
142 static tree tsubst_aggr_type PARAMS ((tree, tree, int, tree, int));
143 static tree tsubst_decl PARAMS ((tree, tree, tree, tree));
144 static tree tsubst_arg_types PARAMS ((tree, tree, int, tree));
145 static tree tsubst_function_type PARAMS ((tree, tree, int, tree));
146 static void check_specialization_scope PARAMS ((void));
147 static tree process_partial_specialization PARAMS ((tree));
148 static void set_current_access_from_decl PARAMS ((tree));
149 static void check_default_tmpl_args PARAMS ((tree, tree, int, int));
150 static tree tsubst_call_declarator_parms PARAMS ((tree, tree, int, tree));
151 static tree get_template_base_recursive PARAMS ((tree, tree,
152 tree, tree, tree, int));
153 static tree get_template_base PARAMS ((tree, tree, tree, tree));
154 static tree try_class_unification PARAMS ((tree, tree, tree, tree));
155 static int coerce_template_template_parms PARAMS ((tree, tree, int,
157 static tree determine_specialization PARAMS ((tree, tree, tree *, int));
158 static int template_args_equal PARAMS ((tree, tree));
159 static void print_template_context PARAMS ((int));
160 static void tsubst_default_arguments PARAMS ((tree));
161 static tree for_each_template_parm_r PARAMS ((tree *, int *, void *));
163 /* Called once to initialize pt.c. */
168 ggc_add_tree_root (&pending_templates, 1);
169 ggc_add_tree_root (&maybe_templates, 1);
170 ggc_add_tree_root (&saved_trees, 1);
173 /* Do any processing required when DECL (a member template declaration
174 using TEMPLATE_PARAMETERS as its innermost parameter list) is
175 finished. Returns the TEMPLATE_DECL corresponding to DECL, unless
176 it is a specialization, in which case the DECL itself is returned. */
179 finish_member_template_decl (decl)
182 if (decl == NULL_TREE || decl == void_type_node)
184 else if (decl == error_mark_node)
185 /* By returning NULL_TREE, the parser will just ignore this
186 declaration. We have already issued the error. */
188 else if (TREE_CODE (decl) == TREE_LIST)
190 /* Assume that the class is the only declspec. */
191 decl = TREE_VALUE (decl);
192 if (IS_AGGR_TYPE (decl) && CLASSTYPE_TEMPLATE_INFO (decl)
193 && ! CLASSTYPE_TEMPLATE_SPECIALIZATION (decl))
195 tree tmpl = CLASSTYPE_TI_TEMPLATE (decl);
196 check_member_template (tmpl);
201 else if (TREE_CODE (decl) == FIELD_DECL)
202 cp_error ("data member `%D' cannot be a member template", decl);
203 else if (DECL_TEMPLATE_INFO (decl))
205 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
207 check_member_template (DECL_TI_TEMPLATE (decl));
208 return DECL_TI_TEMPLATE (decl);
214 cp_error ("invalid member template declaration `%D'", decl);
216 return error_mark_node;
219 /* Returns the template nesting level of the indicated class TYPE.
229 A<T>::B<U> has depth two, while A<T> has depth one.
230 Both A<T>::B<int> and A<int>::B<U> have depth one, if
231 COUNT_SPECIALIZATIONS is 0 or if they are instantiations, not
234 This function is guaranteed to return 0 if passed NULL_TREE so
235 that, for example, `template_class_depth (current_class_type)' is
239 template_class_depth_real (type, count_specializations)
241 int count_specializations;
246 type && TREE_CODE (type) != NAMESPACE_DECL;
247 type = (TREE_CODE (type) == FUNCTION_DECL)
248 ? CP_DECL_CONTEXT (type) : TYPE_CONTEXT (type))
250 if (TREE_CODE (type) != FUNCTION_DECL)
252 if (CLASSTYPE_TEMPLATE_INFO (type)
253 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type))
254 && ((count_specializations
255 && CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
256 || uses_template_parms (CLASSTYPE_TI_ARGS (type))))
261 if (DECL_TEMPLATE_INFO (type)
262 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (type))
263 && ((count_specializations
264 && DECL_TEMPLATE_SPECIALIZATION (type))
265 || uses_template_parms (DECL_TI_ARGS (type))))
273 /* Returns the template nesting level of the indicated class TYPE.
274 Like template_class_depth_real, but instantiations do not count in
278 template_class_depth (type)
281 return template_class_depth_real (type, /*count_specializations=*/0);
284 /* Returns 1 if processing DECL as part of do_pending_inlines
285 needs us to push template parms. */
288 inline_needs_template_parms (decl)
291 if (! DECL_TEMPLATE_INFO (decl))
294 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
295 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
298 /* Subroutine of maybe_begin_member_template_processing.
299 Push the template parms in PARMS, starting from LEVELS steps into the
300 chain, and ending at the beginning, since template parms are listed
304 push_inline_template_parms_recursive (parmlist, levels)
308 tree parms = TREE_VALUE (parmlist);
312 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
314 ++processing_template_decl;
315 current_template_parms
316 = tree_cons (build_int_2 (0, processing_template_decl),
317 parms, current_template_parms);
318 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
321 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
323 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
324 my_friendly_assert (DECL_P (parm), 0);
326 switch (TREE_CODE (parm))
335 /* Make a CONST_DECL as is done in process_template_parm.
336 It is ugly that we recreate this here; the original
337 version built in process_template_parm is no longer
339 tree decl = build_decl (CONST_DECL, DECL_NAME (parm),
341 SET_DECL_ARTIFICIAL (decl);
342 DECL_INITIAL (decl) = DECL_INITIAL (parm);
343 SET_DECL_TEMPLATE_PARM_P (decl);
349 my_friendly_abort (0);
354 /* Restore the template parameter context for a member template or
355 a friend template defined in a class definition. */
358 maybe_begin_member_template_processing (decl)
364 if (inline_needs_template_parms (decl))
366 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
367 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
369 if (DECL_TEMPLATE_SPECIALIZATION (decl))
372 parms = TREE_CHAIN (parms);
375 push_inline_template_parms_recursive (parms, levels);
378 /* Remember how many levels of template parameters we pushed so that
379 we can pop them later. */
380 if (!inline_parm_levels)
381 VARRAY_INT_INIT (inline_parm_levels, 4, "inline_parm_levels");
382 if (inline_parm_levels_used == inline_parm_levels->num_elements)
383 VARRAY_GROW (inline_parm_levels, 2 * inline_parm_levels_used);
384 VARRAY_INT (inline_parm_levels, inline_parm_levels_used) = levels;
385 ++inline_parm_levels_used;
388 /* Undo the effects of begin_member_template_processing. */
391 maybe_end_member_template_processing ()
395 if (!inline_parm_levels_used)
398 --inline_parm_levels_used;
400 i < VARRAY_INT (inline_parm_levels, inline_parm_levels_used);
403 --processing_template_decl;
404 current_template_parms = TREE_CHAIN (current_template_parms);
409 /* Returns non-zero iff T is a member template function. We must be
412 template <class T> class C { void f(); }
414 Here, f is a template function, and a member, but not a member
415 template. This function does not concern itself with the origin of
416 T, only its present state. So if we have
418 template <class T> class C { template <class U> void f(U); }
420 then neither C<int>::f<char> nor C<T>::f<double> is considered
421 to be a member template. But, `template <class U> void
422 C<int>::f(U)' is considered a member template. */
425 is_member_template (t)
428 if (!DECL_FUNCTION_TEMPLATE_P (t))
429 /* Anything that isn't a function or a template function is
430 certainly not a member template. */
433 /* A local class can't have member templates. */
434 if (decl_function_context (t))
437 return (DECL_FUNCTION_MEMBER_P (DECL_TEMPLATE_RESULT (t))
438 /* If there are more levels of template parameters than
439 there are template classes surrounding the declaration,
440 then we have a member template. */
441 && (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (t)) >
442 template_class_depth (DECL_CONTEXT (t))));
446 /* Returns non-zero iff T is a member template class. See
447 is_member_template for a description of what precisely constitutes
448 a member template. */
451 is_member_template_class (t)
454 if (!DECL_CLASS_TEMPLATE_P (t))
455 /* Anything that isn't a class template, is certainly not a member
459 if (!DECL_CLASS_SCOPE_P (t))
460 /* Anything whose context isn't a class type is surely not a
464 /* If there are more levels of template parameters than there are
465 template classes surrounding the declaration, then we have a
467 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (t)) >
468 template_class_depth (DECL_CONTEXT (t)));
472 /* Return a new template argument vector which contains all of ARGS,
473 but has as its innermost set of arguments the EXTRA_ARGS. The
474 resulting vector will be built on a temporary obstack, and so must
475 be explicitly copied to the permanent obstack, if required. */
478 add_to_template_args (args, extra_args)
487 extra_depth = TMPL_ARGS_DEPTH (extra_args);
488 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
490 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
491 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
493 for (j = 1; j <= extra_depth; ++j, ++i)
494 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
499 /* Like add_to_template_args, but only the outermost ARGS are added to
500 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
501 (EXTRA_ARGS) levels are added. This function is used to combine
502 the template arguments from a partial instantiation with the
503 template arguments used to attain the full instantiation from the
504 partial instantiation. */
507 add_outermost_template_args (args, extra_args)
513 /* If there are more levels of EXTRA_ARGS than there are ARGS,
514 something very fishy is going on. */
515 my_friendly_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args),
518 /* If *all* the new arguments will be the EXTRA_ARGS, just return
520 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
523 /* For the moment, we make ARGS look like it contains fewer levels. */
524 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
526 new_args = add_to_template_args (args, extra_args);
528 /* Now, we restore ARGS to its full dimensions. */
529 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
534 /* We've got a template header coming up; push to a new level for storing
538 begin_template_parm_list ()
540 /* We use a non-tag-transparent scope here, which causes pushtag to
541 put tags in this scope, rather than in the enclosing class or
542 namespace scope. This is the right thing, since we want
543 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
544 global template class, push_template_decl handles putting the
545 TEMPLATE_DECL into top-level scope. For a nested template class,
548 template <class T> struct S1 {
549 template <class T> struct S2 {};
552 pushtag contains special code to call pushdecl_with_scope on the
553 TEMPLATE_DECL for S2. */
554 begin_scope (sk_template_parms);
555 ++processing_template_decl;
556 ++processing_template_parmlist;
557 note_template_header (0);
560 /* This routine is called when a specialization is declared. If it is
561 illegal to declare a specialization here, an error is reported. */
564 check_specialization_scope ()
566 tree scope = current_scope ();
570 An explicit specialization shall be declared in the namespace of
571 which the template is a member, or, for member templates, in the
572 namespace of which the enclosing class or enclosing class
573 template is a member. An explicit specialization of a member
574 function, member class or static data member of a class template
575 shall be declared in the namespace of which the class template
577 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
578 cp_error ("explicit specialization in non-namespace scope `%D'",
583 In an explicit specialization declaration for a member of a class
584 template or a member template that appears in namespace scope,
585 the member template and some of its enclosing class templates may
586 remain unspecialized, except that the declaration shall not
587 explicitly specialize a class member template if its enclosing
588 class templates are not explicitly specialized as well. */
589 if (current_template_parms)
590 cp_error ("enclosing class templates are not explicitly specialized");
593 /* We've just seen template <>. */
596 begin_specialization ()
598 begin_scope (sk_template_spec);
599 note_template_header (1);
600 check_specialization_scope ();
603 /* Called at then end of processing a declaration preceeded by
607 end_specialization ()
610 reset_specialization ();
613 /* Any template <>'s that we have seen thus far are not referring to a
614 function specialization. */
617 reset_specialization ()
619 processing_specialization = 0;
620 template_header_count = 0;
623 /* We've just seen a template header. If SPECIALIZATION is non-zero,
624 it was of the form template <>. */
627 note_template_header (specialization)
630 processing_specialization = specialization;
631 template_header_count++;
634 /* We're beginning an explicit instantiation. */
637 begin_explicit_instantiation ()
639 ++processing_explicit_instantiation;
644 end_explicit_instantiation ()
646 my_friendly_assert(processing_explicit_instantiation > 0, 0);
647 --processing_explicit_instantiation;
650 /* The TYPE is being declared. If it is a template type, that means it
651 is a partial specialization. Do appropriate error-checking. */
654 maybe_process_partial_specialization (type)
657 if (IS_AGGR_TYPE (type) && CLASSTYPE_USE_TEMPLATE (type))
659 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
660 && !COMPLETE_TYPE_P (type))
662 if (current_namespace
663 != decl_namespace_context (CLASSTYPE_TI_TEMPLATE (type)))
665 cp_pedwarn ("specializing `%#T' in different namespace", type);
666 cp_pedwarn_at (" from definition of `%#D'",
667 CLASSTYPE_TI_TEMPLATE (type));
669 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
670 if (processing_template_decl)
671 push_template_decl (TYPE_MAIN_DECL (type));
673 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
674 cp_error ("specialization of `%T' after instantiation", type);
676 else if (processing_specialization)
677 cp_error ("explicit specialization of non-template `%T'", type);
680 /* Retrieve the specialization (in the sense of [temp.spec] - a
681 specialization is either an instantiation or an explicit
682 specialization) of TMPL for the given template ARGS. If there is
683 no such specialization, return NULL_TREE. The ARGS are a vector of
684 arguments, or a vector of vectors of arguments, in the case of
685 templates with more than one level of parameters. */
688 retrieve_specialization (tmpl, args)
694 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 0);
696 /* There should be as many levels of arguments as there are
697 levels of parameters. */
698 my_friendly_assert (TMPL_ARGS_DEPTH (args)
699 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)),
702 for (s = DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
705 if (comp_template_args (TREE_PURPOSE (s), args))
706 return TREE_VALUE (s);
711 /* Like retrieve_speciailization, but for local declarations. FN is
712 the function in which we are looking for an instantiation. */
715 retrieve_local_specialization (tmpl, fn)
719 tree s = purpose_member (fn, DECL_TEMPLATE_SPECIALIZATIONS (tmpl));
720 return s ? TREE_VALUE (s) : NULL_TREE;
723 /* Returns non-zero iff DECL is a specialization of TMPL. */
726 is_specialization_of (decl, tmpl)
732 if (TREE_CODE (decl) == FUNCTION_DECL)
736 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
742 my_friendly_assert (TREE_CODE (decl) == TYPE_DECL, 0);
744 for (t = TREE_TYPE (decl);
746 t = CLASSTYPE_USE_TEMPLATE (t)
747 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
748 if (same_type_p (TYPE_MAIN_VARIANT (t),
749 TYPE_MAIN_VARIANT (TREE_TYPE (tmpl))))
756 /* Register the specialization SPEC as a specialization of TMPL with
757 the indicated ARGS. Returns SPEC, or an equivalent prior
758 declaration, if available. */
761 register_specialization (spec, tmpl, args)
768 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 0);
770 if (TREE_CODE (spec) == FUNCTION_DECL
771 && uses_template_parms (DECL_TI_ARGS (spec)))
772 /* This is the FUNCTION_DECL for a partial instantiation. Don't
773 register it; we want the corresponding TEMPLATE_DECL instead.
774 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
775 the more obvious `uses_template_parms (spec)' to avoid problems
776 with default function arguments. In particular, given
779 template <class T> void f(T t1, T t = T())
781 the default argument expression is not substituted for in an
782 instantiation unless and until it is actually needed. */
785 /* There should be as many levels of arguments as there are
786 levels of parameters. */
787 my_friendly_assert (TMPL_ARGS_DEPTH (args)
788 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)),
791 for (s = DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
795 tree fn = TREE_VALUE (s);
797 /* We can sometimes try to re-register a specialization that we've
798 already got. In particular, regenerate_decl_from_template
799 calls duplicate_decls which will update the specialization
800 list. But, we'll still get called again here anyhow. It's
801 more convenient to simply allow this than to try to prevent it. */
804 else if (comp_template_args (TREE_PURPOSE (s), args))
806 if (DECL_TEMPLATE_SPECIALIZATION (spec))
808 if (DECL_TEMPLATE_INSTANTIATION (fn))
811 || DECL_EXPLICIT_INSTANTIATION (fn))
813 cp_error ("specialization of %D after instantiation",
819 /* This situation should occur only if the first
820 specialization is an implicit instantiation,
821 the second is an explicit specialization, and
822 the implicit instantiation has not yet been
823 used. That situation can occur if we have
824 implicitly instantiated a member function and
825 then specialized it later.
827 We can also wind up here if a friend
828 declaration that looked like an instantiation
829 turns out to be a specialization:
831 template <class T> void foo(T);
832 class S { friend void foo<>(int) };
833 template <> void foo(int);
835 We transform the existing DECL in place so that
836 any pointers to it become pointers to the
839 If there was a definition for the template, but
840 not for the specialization, we want this to
841 look as if there is no definition, and vice
843 DECL_INITIAL (fn) = NULL_TREE;
844 duplicate_decls (spec, fn);
849 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
851 duplicate_decls (spec, fn);
858 DECL_TEMPLATE_SPECIALIZATIONS (tmpl)
859 = tree_cons (args, spec, DECL_TEMPLATE_SPECIALIZATIONS (tmpl));
864 /* Unregister the specialization SPEC as a specialization of TMPL.
865 Returns nonzero if the SPEC was listed as a specialization of
869 unregister_specialization (spec, tmpl)
875 for (s = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
877 s = &TREE_CHAIN (*s))
878 if (TREE_VALUE (*s) == spec)
880 *s = TREE_CHAIN (*s);
887 /* Like register_specialization, but for local declarations. FN is
888 the function in which we are registering SPEC, an instantiation of
892 register_local_specialization (spec, tmpl, fn)
897 DECL_TEMPLATE_SPECIALIZATIONS (tmpl)
898 = tree_cons (fn, spec, DECL_TEMPLATE_SPECIALIZATIONS (tmpl));
903 /* Print the list of candidate FNS in an error message. */
906 print_candidates (fns)
911 const char *str = "candidates are:";
913 for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
917 for (f = TREE_VALUE (fn); f; f = OVL_NEXT (f))
918 cp_error_at ("%s %+#D", str, OVL_CURRENT (f));
923 /* Returns the template (one of the functions given by TEMPLATE_ID)
924 which can be specialized to match the indicated DECL with the
925 explicit template args given in TEMPLATE_ID. The DECL may be
926 NULL_TREE if none is available. In that case, the functions in
927 TEMPLATE_ID are non-members.
929 If NEED_MEMBER_TEMPLATE is non-zero the function is known to be a
930 specialization of a member template.
932 The template args (those explicitly specified and those deduced)
933 are output in a newly created vector *TARGS_OUT.
935 If it is impossible to determine the result, an error message is
936 issued. The error_mark_node is returned to indicate failure. */
939 determine_specialization (template_id, decl, targs_out,
940 need_member_template)
944 int need_member_template;
949 tree candidates = NULL_TREE;
950 tree templates = NULL_TREE;
952 *targs_out = NULL_TREE;
954 if (template_id == error_mark_node)
955 return error_mark_node;
957 fns = TREE_OPERAND (template_id, 0);
958 explicit_targs = TREE_OPERAND (template_id, 1);
960 if (fns == error_mark_node)
961 return error_mark_node;
963 /* Check for baselinks. */
964 if (BASELINK_P (fns))
965 fns = TREE_VALUE (fns);
967 if (!is_overloaded_fn (fns))
969 cp_error ("`%D' is not a function template", fns);
970 return error_mark_node;
973 for (; fns; fns = OVL_NEXT (fns))
977 tree fn = OVL_CURRENT (fns);
979 if (TREE_CODE (fn) == TEMPLATE_DECL)
980 /* DECL might be a specialization of FN. */
982 else if (need_member_template)
983 /* FN is an ordinary member function, and we need a
984 specialization of a member template. */
986 else if (TREE_CODE (fn) != FUNCTION_DECL)
987 /* We can get IDENTIFIER_NODEs here in certain erroneous
990 else if (!DECL_FUNCTION_MEMBER_P (fn))
991 /* This is just an ordinary non-member function. Nothing can
992 be a specialization of that. */
998 /* This is an ordinary member function. However, since
999 we're here, we can assume it's enclosing class is a
1000 template class. For example,
1002 template <typename T> struct S { void f(); };
1003 template <> void S<int>::f() {}
1005 Here, S<int>::f is a non-template, but S<int> is a
1006 template class. If FN has the same type as DECL, we
1007 might be in business. */
1008 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1009 TREE_TYPE (TREE_TYPE (fn))))
1010 /* The return types differ. */
1013 /* Adjust the type of DECL in case FN is a static member. */
1014 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1015 if (DECL_STATIC_FUNCTION_P (fn)
1016 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1017 decl_arg_types = TREE_CHAIN (decl_arg_types);
1019 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1022 candidates = tree_cons (NULL_TREE, fn, candidates);
1027 /* See whether this function might be a specialization of this
1029 targs = get_bindings (tmpl, decl, explicit_targs);
1032 /* We cannot deduce template arguments that when used to
1033 specialize TMPL will produce DECL. */
1036 /* Save this template, and the arguments deduced. */
1037 templates = tree_cons (targs, tmpl, templates);
1040 if (templates && TREE_CHAIN (templates))
1046 It is possible for a specialization with a given function
1047 signature to be instantiated from more than one function
1048 template. In such cases, explicit specification of the
1049 template arguments must be used to uniquely identify the
1050 function template specialization being specialized.
1052 Note that here, there's no suggestion that we're supposed to
1053 determine which of the candidate templates is most
1054 specialized. However, we, also have:
1058 Partial ordering of overloaded function template
1059 declarations is used in the following contexts to select
1060 the function template to which a function template
1061 specialization refers:
1063 -- when an explicit specialization refers to a function
1066 So, we do use the partial ordering rules, at least for now.
1067 This extension can only serve to make illegal programs legal,
1068 so it's safe. And, there is strong anecdotal evidence that
1069 the committee intended the partial ordering rules to apply;
1070 the EDG front-end has that behavior, and John Spicer claims
1071 that the committee simply forgot to delete the wording in
1072 [temp.expl.spec]. */
1073 tree tmpl = most_specialized (templates, decl, explicit_targs);
1074 if (tmpl && tmpl != error_mark_node)
1076 targs = get_bindings (tmpl, decl, explicit_targs);
1077 templates = tree_cons (targs, tmpl, NULL_TREE);
1081 if (templates == NULL_TREE && candidates == NULL_TREE)
1083 cp_error_at ("template-id `%D' for `%+D' does not match any template declaration",
1085 return error_mark_node;
1087 else if ((templates && TREE_CHAIN (templates))
1088 || (candidates && TREE_CHAIN (candidates))
1089 || (templates && candidates))
1091 cp_error_at ("ambiguous template specialization `%D' for `%+D'",
1093 chainon (candidates, templates);
1094 print_candidates (candidates);
1095 return error_mark_node;
1098 /* We have one, and exactly one, match. */
1101 /* It was a specialization of an ordinary member function in a
1103 *targs_out = copy_node (DECL_TI_ARGS (TREE_VALUE (candidates)));
1104 return DECL_TI_TEMPLATE (TREE_VALUE (candidates));
1107 /* It was a specialization of a template. */
1108 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1109 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1111 *targs_out = copy_node (targs);
1112 SET_TMPL_ARGS_LEVEL (*targs_out,
1113 TMPL_ARGS_DEPTH (*targs_out),
1114 TREE_PURPOSE (templates));
1117 *targs_out = TREE_PURPOSE (templates);
1118 return TREE_VALUE (templates);
1121 /* Check to see if the function just declared, as indicated in
1122 DECLARATOR, and in DECL, is a specialization of a function
1123 template. We may also discover that the declaration is an explicit
1124 instantiation at this point.
1126 Returns DECL, or an equivalent declaration that should be used
1127 instead if all goes well. Issues an error message if something is
1128 amiss. Returns error_mark_node if the error is not easily
1131 FLAGS is a bitmask consisting of the following flags:
1133 2: The function has a definition.
1134 4: The function is a friend.
1136 The TEMPLATE_COUNT is the number of references to qualifying
1137 template classes that appeared in the name of the function. For
1140 template <class T> struct S { void f(); };
1143 the TEMPLATE_COUNT would be 1. However, explicitly specialized
1144 classes are not counted in the TEMPLATE_COUNT, so that in
1146 template <class T> struct S {};
1147 template <> struct S<int> { void f(); }
1148 template <> void S<int>::f();
1150 the TEMPLATE_COUNT would be 0. (Note that this declaration is
1151 illegal; there should be no template <>.)
1153 If the function is a specialization, it is marked as such via
1154 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
1155 is set up correctly, and it is added to the list of specializations
1156 for that template. */
1159 check_explicit_specialization (declarator, decl, template_count, flags)
1165 int have_def = flags & 2;
1166 int is_friend = flags & 4;
1167 int specialization = 0;
1168 int explicit_instantiation = 0;
1169 int member_specialization = 0;
1170 tree ctype = DECL_CLASS_CONTEXT (decl);
1171 tree dname = DECL_NAME (decl);
1174 tsk = current_tmpl_spec_kind (template_count);
1179 if (processing_specialization)
1182 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1184 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1187 /* This could be something like:
1189 template <class T> void f(T);
1190 class S { friend void f<>(int); } */
1194 /* This case handles bogus declarations like template <>
1195 template <class T> void f<int>(); */
1197 cp_error ("template-id `%D' in declaration of primary template",
1204 case tsk_invalid_member_spec:
1205 /* The error has already been reported in
1206 check_specialization_scope. */
1207 return error_mark_node;
1209 case tsk_invalid_expl_inst:
1210 cp_error ("template parameter list used in explicit instantiation");
1216 cp_error ("definition provided for explicit instantiation");
1218 explicit_instantiation = 1;
1221 case tsk_excessive_parms:
1222 cp_error ("too many template parameter lists in declaration of `%D'",
1224 return error_mark_node;
1228 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1230 member_specialization = 1;
1235 case tsk_insufficient_parms:
1236 if (template_header_count)
1238 cp_error("too few template parameter lists in declaration of `%D'",
1242 else if (ctype != NULL_TREE
1243 && !TYPE_BEING_DEFINED (ctype)
1244 && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype)
1247 /* For backwards compatibility, we accept:
1249 template <class T> struct S { void f(); };
1250 void S<int>::f() {} // Missing template <>
1252 That used to be legal C++. */
1255 ("explicit specialization not preceded by `template <>'");
1257 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1262 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1264 /* This case handles bogus declarations like template <>
1265 template <class T> void f<int>(); */
1267 cp_error ("template-id `%D' in declaration of primary template",
1272 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
1273 /* This is a specialization of a member template, without
1274 specialization the containing class. Something like:
1276 template <class T> struct S {
1277 template <class U> void f (U);
1279 template <> template <class U> void S<int>::f(U) {}
1281 That's a specialization -- but of the entire template. */
1286 my_friendly_abort (20000309);
1289 if (specialization || member_specialization)
1291 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
1292 for (; t; t = TREE_CHAIN (t))
1293 if (TREE_PURPOSE (t))
1296 ("default argument specified in explicit specialization");
1299 if (current_lang_name == lang_name_c)
1300 cp_error ("template specialization with C linkage");
1303 if (specialization || member_specialization || explicit_instantiation)
1305 tree tmpl = NULL_TREE;
1306 tree targs = NULL_TREE;
1308 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
1309 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
1313 my_friendly_assert (TREE_CODE (declarator) == IDENTIFIER_NODE,
1316 fns = IDENTIFIER_NAMESPACE_VALUE (dname);
1321 lookup_template_function (fns, NULL_TREE);
1324 if (declarator == error_mark_node)
1325 return error_mark_node;
1327 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
1329 if (!explicit_instantiation)
1330 /* A specialization in class scope. This is illegal,
1331 but the error will already have been flagged by
1332 check_specialization_scope. */
1333 return error_mark_node;
1336 /* It's not legal to write an explicit instantiation in
1339 class C { template void f(); }
1341 This case is caught by the parser. However, on
1344 template class C { void f(); };
1346 (which is illegal) we can get here. The error will be
1353 else if (TREE_CODE (TREE_OPERAND (declarator, 0)) == LOOKUP_EXPR)
1355 /* A friend declaration. We can't do much, because we don't
1356 know what this resolves to, yet. */
1357 my_friendly_assert (is_friend != 0, 0);
1358 my_friendly_assert (!explicit_instantiation, 0);
1359 SET_DECL_IMPLICIT_INSTANTIATION (decl);
1362 else if (ctype != NULL_TREE
1363 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
1366 /* Find the list of functions in ctype that have the same
1367 name as the declared function. */
1368 tree name = TREE_OPERAND (declarator, 0);
1369 tree fns = NULL_TREE;
1372 if (name == constructor_name (ctype)
1373 || name == constructor_name_full (ctype))
1375 int is_constructor = DECL_CONSTRUCTOR_P (decl);
1377 if (is_constructor ? !TYPE_HAS_CONSTRUCTOR (ctype)
1378 : !TYPE_HAS_DESTRUCTOR (ctype))
1380 /* From [temp.expl.spec]:
1382 If such an explicit specialization for the member
1383 of a class template names an implicitly-declared
1384 special member function (clause _special_), the
1385 program is ill-formed.
1387 Similar language is found in [temp.explicit]. */
1388 cp_error ("specialization of implicitly-declared special member function");
1389 return error_mark_node;
1392 name = is_constructor ? ctor_identifier : dtor_identifier;
1395 if (!IDENTIFIER_TYPENAME_P (name))
1397 idx = lookup_fnfields_1 (ctype, name);
1399 fns = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (ctype), idx);
1405 /* For a type-conversion operator, we cannot do a
1406 name-based lookup. We might be looking for `operator
1407 int' which will be a specialization of `operator T'.
1408 So, we find *all* the conversion operators, and then
1409 select from them. */
1412 methods = CLASSTYPE_METHOD_VEC (ctype);
1414 for (idx = 2; idx < TREE_VEC_LENGTH (methods); ++idx)
1416 tree ovl = TREE_VEC_ELT (methods, idx);
1418 if (!ovl || !DECL_CONV_FN_P (OVL_CURRENT (ovl)))
1419 /* There are no more conversion functions. */
1422 /* Glue all these conversion functions together
1423 with those we already have. */
1424 for (; ovl; ovl = OVL_NEXT (ovl))
1425 fns = ovl_cons (OVL_CURRENT (ovl), fns);
1429 if (fns == NULL_TREE)
1431 cp_error ("no member function `%D' declared in `%T'",
1433 return error_mark_node;
1436 TREE_OPERAND (declarator, 0) = fns;
1439 /* Figure out what exactly is being specialized at this point.
1440 Note that for an explicit instantiation, even one for a
1441 member function, we cannot tell apriori whether the
1442 instantiation is for a member template, or just a member
1443 function of a template class. Even if a member template is
1444 being instantiated, the member template arguments may be
1445 elided if they can be deduced from the rest of the
1447 tmpl = determine_specialization (declarator, decl,
1449 member_specialization);
1451 if (!tmpl || tmpl == error_mark_node)
1452 /* We couldn't figure out what this declaration was
1454 return error_mark_node;
1457 tree gen_tmpl = most_general_template (tmpl);
1459 if (explicit_instantiation)
1461 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
1462 is done by do_decl_instantiation later. */
1464 int arg_depth = TMPL_ARGS_DEPTH (targs);
1465 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
1467 if (arg_depth > parm_depth)
1469 /* If TMPL is not the most general template (for
1470 example, if TMPL is a friend template that is
1471 injected into namespace scope), then there will
1472 be too many levels fo TARGS. Remove some of them
1477 new_targs = make_tree_vec (parm_depth);
1478 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
1479 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
1480 = TREE_VEC_ELT (targs, i);
1484 return instantiate_template (tmpl, targs);
1487 /* If this is both a template specialization, then it's a
1488 specialization of a member template of a template class.
1489 In that case we want to return the TEMPLATE_DECL, not the
1490 specialization of it. */
1491 if (tsk == tsk_template)
1493 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
1497 /* If we though that the DECL was a member function, but it
1498 turns out to be specializing a static member function,
1499 make DECL a static member function as well. */
1500 if (DECL_STATIC_FUNCTION_P (tmpl)
1501 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1503 revert_static_member_fn (decl);
1504 last_function_parms = TREE_CHAIN (last_function_parms);
1507 /* Set up the DECL_TEMPLATE_INFO for DECL. */
1508 DECL_TEMPLATE_INFO (decl) = tree_cons (tmpl, targs, NULL_TREE);
1510 /* Mangle the function name appropriately. Note that we do
1511 not mangle specializations of non-template member
1512 functions of template classes, e.g. with
1514 template <class T> struct S { void f(); }
1516 and given the specialization
1518 template <> void S<int>::f() {}
1520 we do not mangle S<int>::f() here. That's because it's
1521 just an ordinary member function and doesn't need special
1522 treatment. We do this here so that the ordinary,
1523 non-template, name-mangling algorithm will not be used
1525 if ((is_member_template (tmpl) || ctype == NULL_TREE)
1526 && name_mangling_version >= 1)
1527 set_mangled_name_for_template_decl (decl);
1529 if (is_friend && !have_def)
1530 /* This is not really a declaration of a specialization.
1531 It's just the name of an instantiation. But, it's not
1532 a request for an instantiation, either. */
1533 SET_DECL_IMPLICIT_INSTANTIATION (decl);
1535 /* Register this specialization so that we can find it
1537 decl = register_specialization (decl, gen_tmpl, targs);
1544 /* TYPE is being declared. Verify that the use of template headers
1545 and such is reasonable. Issue error messages if not. */
1548 maybe_check_template_type (type)
1551 if (template_header_count)
1553 /* We are in the scope of some `template <...>' header. */
1556 = template_class_depth_real (TYPE_CONTEXT (type),
1557 /*count_specializations=*/1);
1559 if (template_header_count <= context_depth)
1560 /* This is OK; the template headers are for the context. We
1561 are actually too lenient here; like
1562 check_explicit_specialization we should consider the number
1563 of template types included in the actual declaration. For
1566 template <class T> struct S {
1567 template <class U> template <class V>
1573 template <class T> struct S {
1574 template <class U> struct I;
1577 template <class T> template <class U.
1582 else if (template_header_count > context_depth + 1)
1583 /* There are two many template parameter lists. */
1584 cp_error ("too many template parameter lists in declaration of `%T'", type);
1588 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
1589 parameters. These are represented in the same format used for
1590 DECL_TEMPLATE_PARMS. */
1592 int comp_template_parms (parms1, parms2)
1599 if (parms1 == parms2)
1602 for (p1 = parms1, p2 = parms2;
1603 p1 != NULL_TREE && p2 != NULL_TREE;
1604 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
1606 tree t1 = TREE_VALUE (p1);
1607 tree t2 = TREE_VALUE (p2);
1610 my_friendly_assert (TREE_CODE (t1) == TREE_VEC, 0);
1611 my_friendly_assert (TREE_CODE (t2) == TREE_VEC, 0);
1613 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
1616 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
1618 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
1619 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
1621 if (TREE_CODE (parm1) != TREE_CODE (parm2))
1624 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM)
1626 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
1631 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
1632 /* One set of parameters has more parameters lists than the
1639 /* Complain if DECL shadows a template parameter.
1641 [temp.local]: A template-parameter shall not be redeclared within its
1642 scope (including nested scopes). */
1645 check_template_shadow (decl)
1650 /* If we're not in a template, we can't possibly shadow a template
1652 if (!current_template_parms)
1655 /* Figure out what we're shadowing. */
1656 if (TREE_CODE (decl) == OVERLOAD)
1657 decl = OVL_CURRENT (decl);
1658 olddecl = IDENTIFIER_VALUE (DECL_NAME (decl));
1660 /* If there's no previous binding for this name, we're not shadowing
1661 anything, let alone a template parameter. */
1665 /* If we're not shadowing a template parameter, we're done. Note
1666 that OLDDECL might be an OVERLOAD (or perhaps even an
1667 ERROR_MARK), so we can't just blithely assume it to be a _DECL
1669 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
1672 /* We check for decl != olddecl to avoid bogus errors for using a
1673 name inside a class. We check TPFI to avoid duplicate errors for
1674 inline member templates. */
1676 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
1679 cp_error_at ("declaration of `%#D'", decl);
1680 cp_error_at (" shadows template parm `%#D'", olddecl);
1683 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
1684 ORIG_LEVEL, DECL, and TYPE. */
1687 build_template_parm_index (index, level, orig_level, decl, type)
1694 tree t = make_node (TEMPLATE_PARM_INDEX);
1695 TEMPLATE_PARM_IDX (t) = index;
1696 TEMPLATE_PARM_LEVEL (t) = level;
1697 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
1698 TEMPLATE_PARM_DECL (t) = decl;
1699 TREE_TYPE (t) = type;
1704 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
1705 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
1706 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
1707 new one is created. */
1710 reduce_template_parm_level (index, type, levels)
1715 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
1716 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
1717 != TEMPLATE_PARM_LEVEL (index) - levels))
1720 = build_decl (TREE_CODE (TEMPLATE_PARM_DECL (index)),
1721 DECL_NAME (TEMPLATE_PARM_DECL (index)),
1724 = build_template_parm_index (TEMPLATE_PARM_IDX (index),
1725 TEMPLATE_PARM_LEVEL (index) - levels,
1726 TEMPLATE_PARM_ORIG_LEVEL (index),
1728 TEMPLATE_PARM_DESCENDANTS (index) = t;
1730 /* Template template parameters need this. */
1731 DECL_TEMPLATE_PARMS (decl)
1732 = DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index));
1735 return TEMPLATE_PARM_DESCENDANTS (index);
1738 /* Process information from new template parameter NEXT and append it to the
1739 LIST being built. */
1742 process_template_parm (list, next)
1751 my_friendly_assert (TREE_CODE (parm) == TREE_LIST, 259);
1752 defval = TREE_PURPOSE (parm);
1753 parm = TREE_VALUE (parm);
1754 is_type = TREE_PURPOSE (parm) == class_type_node;
1758 tree p = TREE_VALUE (tree_last (list));
1760 if (TREE_CODE (p) == TYPE_DECL)
1761 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
1762 else if (TREE_CODE (p) == TEMPLATE_DECL)
1763 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (DECL_TEMPLATE_RESULT (p)));
1765 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
1773 my_friendly_assert (TREE_CODE (TREE_PURPOSE (parm)) == TREE_LIST, 260);
1774 /* is a const-param */
1775 parm = grokdeclarator (TREE_VALUE (parm), TREE_PURPOSE (parm),
1776 PARM, 0, NULL_TREE);
1780 The top-level cv-qualifiers on the template-parameter are
1781 ignored when determining its type. */
1782 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
1784 /* A template parameter is not modifiable. */
1785 TREE_READONLY (parm) = 1;
1786 if (IS_AGGR_TYPE (TREE_TYPE (parm))
1787 && TREE_CODE (TREE_TYPE (parm)) != TEMPLATE_TYPE_PARM
1788 && TREE_CODE (TREE_TYPE (parm)) != TYPENAME_TYPE)
1790 cp_error ("`%#T' is not a valid type for a template constant parameter",
1792 if (DECL_NAME (parm) == NULL_TREE)
1793 error (" a template type parameter must begin with `class' or `typename'");
1794 TREE_TYPE (parm) = void_type_node;
1797 && (TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE
1798 || TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE))
1799 cp_pedwarn ("`%T' is not a valid type for a template constant parameter",
1801 decl = build_decl (CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
1802 DECL_INITIAL (parm) = DECL_INITIAL (decl)
1803 = build_template_parm_index (idx, processing_template_decl,
1804 processing_template_decl,
1805 decl, TREE_TYPE (parm));
1810 parm = TREE_VALUE (parm);
1812 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
1814 t = make_aggr_type (TEMPLATE_TEMPLATE_PARM);
1815 /* This is for distinguishing between real templates and template
1816 template parameters */
1817 TREE_TYPE (parm) = t;
1818 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
1823 t = make_aggr_type (TEMPLATE_TYPE_PARM);
1824 /* parm is either IDENTIFIER_NODE or NULL_TREE */
1825 decl = build_decl (TYPE_DECL, parm, t);
1828 TYPE_NAME (t) = decl;
1829 TYPE_STUB_DECL (t) = decl;
1831 TEMPLATE_TYPE_PARM_INDEX (t)
1832 = build_template_parm_index (idx, processing_template_decl,
1833 processing_template_decl,
1834 decl, TREE_TYPE (parm));
1836 SET_DECL_ARTIFICIAL (decl);
1837 SET_DECL_TEMPLATE_PARM_P (decl);
1839 parm = build_tree_list (defval, parm);
1840 return chainon (list, parm);
1843 /* The end of a template parameter list has been reached. Process the
1844 tree list into a parameter vector, converting each parameter into a more
1845 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
1849 end_template_parm_list (parms)
1854 tree saved_parmlist = make_tree_vec (list_length (parms));
1856 current_template_parms
1857 = tree_cons (build_int_2 (0, processing_template_decl),
1858 saved_parmlist, current_template_parms);
1860 for (parm = parms, nparms = 0;
1862 parm = TREE_CHAIN (parm), nparms++)
1863 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
1865 --processing_template_parmlist;
1867 return saved_parmlist;
1870 /* end_template_decl is called after a template declaration is seen. */
1873 end_template_decl ()
1875 reset_specialization ();
1877 if (! processing_template_decl)
1880 /* This matches the pushlevel in begin_template_parm_list. */
1883 --processing_template_decl;
1884 current_template_parms = TREE_CHAIN (current_template_parms);
1887 /* Given a template argument vector containing the template PARMS.
1888 The innermost PARMS are given first. */
1891 current_template_args ()
1894 tree args = NULL_TREE;
1895 int length = TMPL_PARMS_DEPTH (current_template_parms);
1898 /* If there is only one level of template parameters, we do not
1899 create a TREE_VEC of TREE_VECs. Instead, we return a single
1900 TREE_VEC containing the arguments. */
1902 args = make_tree_vec (length);
1904 for (header = current_template_parms; header; header = TREE_CHAIN (header))
1906 tree a = copy_node (TREE_VALUE (header));
1909 TREE_TYPE (a) = NULL_TREE;
1910 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
1912 tree t = TREE_VEC_ELT (a, i);
1914 /* T will be a list if we are called from within a
1915 begin/end_template_parm_list pair, but a vector directly
1916 if within a begin/end_member_template_processing pair. */
1917 if (TREE_CODE (t) == TREE_LIST)
1921 if (TREE_CODE (t) == TYPE_DECL
1922 || TREE_CODE (t) == TEMPLATE_DECL)
1925 t = DECL_INITIAL (t);
1926 TREE_VEC_ELT (a, i) = t;
1931 TREE_VEC_ELT (args, --l) = a;
1939 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
1940 template PARMS. Used by push_template_decl below. */
1943 build_template_decl (decl, parms)
1947 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
1948 DECL_TEMPLATE_PARMS (tmpl) = parms;
1949 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
1950 if (DECL_LANG_SPECIFIC (decl))
1952 DECL_VIRTUAL_CONTEXT (tmpl) = DECL_VIRTUAL_CONTEXT (decl);
1953 DECL_STATIC_FUNCTION_P (tmpl) = DECL_STATIC_FUNCTION_P (decl);
1954 DECL_CONSTRUCTOR_P (tmpl) = DECL_CONSTRUCTOR_P (decl);
1955 DECL_NONCONVERTING_P (tmpl) = DECL_NONCONVERTING_P (decl);
1961 struct template_parm_data
1963 /* The level of the template parameters we are currently
1967 /* The index of the specialization argument we are currently
1971 /* An array whose size is the number of template parameters. The
1972 elements are non-zero if the parameter has been used in any one
1973 of the arguments processed so far. */
1976 /* An array whose size is the number of template arguments. The
1977 elements are non-zero if the argument makes use of template
1978 parameters of this level. */
1979 int* arg_uses_template_parms;
1982 /* Subroutine of push_template_decl used to see if each template
1983 parameter in a partial specialization is used in the explicit
1984 argument list. If T is of the LEVEL given in DATA (which is
1985 treated as a template_parm_data*), then DATA->PARMS is marked
1989 mark_template_parm (t, data)
1995 struct template_parm_data* tpd = (struct template_parm_data*) data;
1997 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
1999 level = TEMPLATE_PARM_LEVEL (t);
2000 idx = TEMPLATE_PARM_IDX (t);
2004 level = TEMPLATE_TYPE_LEVEL (t);
2005 idx = TEMPLATE_TYPE_IDX (t);
2008 if (level == tpd->level)
2010 tpd->parms[idx] = 1;
2011 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
2014 /* Return zero so that for_each_template_parm will continue the
2015 traversal of the tree; we want to mark *every* template parm. */
2019 /* Process the partial specialization DECL. */
2022 process_partial_specialization (decl)
2025 tree type = TREE_TYPE (decl);
2026 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
2027 tree specargs = CLASSTYPE_TI_ARGS (type);
2028 tree inner_args = innermost_args (specargs);
2029 tree inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
2030 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
2031 int nargs = TREE_VEC_LENGTH (inner_args);
2032 int ntparms = TREE_VEC_LENGTH (inner_parms);
2034 int did_error_intro = 0;
2035 struct template_parm_data tpd;
2036 struct template_parm_data tpd2;
2038 /* We check that each of the template parameters given in the
2039 partial specialization is used in the argument list to the
2040 specialization. For example:
2042 template <class T> struct S;
2043 template <class T> struct S<T*>;
2045 The second declaration is OK because `T*' uses the template
2046 parameter T, whereas
2048 template <class T> struct S<int>;
2050 is no good. Even trickier is:
2061 The S2<T> declaration is actually illegal; it is a
2062 full-specialization. Of course,
2065 struct S2<T (*)(U)>;
2067 or some such would have been OK. */
2068 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
2069 tpd.parms = alloca (sizeof (int) * ntparms);
2070 bzero ((PTR) tpd.parms, sizeof (int) * ntparms);
2072 tpd.arg_uses_template_parms = alloca (sizeof (int) * nargs);
2073 bzero ((PTR) tpd.arg_uses_template_parms, sizeof (int) * nargs);
2074 for (i = 0; i < nargs; ++i)
2076 tpd.current_arg = i;
2077 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
2078 &mark_template_parm,
2081 for (i = 0; i < ntparms; ++i)
2082 if (tpd.parms[i] == 0)
2084 /* One of the template parms was not used in the
2086 if (!did_error_intro)
2088 cp_error ("template parameters not used in partial specialization:");
2089 did_error_intro = 1;
2093 TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
2096 /* [temp.class.spec]
2098 The argument list of the specialization shall not be identical to
2099 the implicit argument list of the primary template. */
2100 if (comp_template_args (inner_args,
2101 innermost_args (CLASSTYPE_TI_ARGS (TREE_TYPE
2103 cp_error ("partial specialization `%T' does not specialize any template arguments", type);
2105 /* [temp.class.spec]
2107 A partially specialized non-type argument expression shall not
2108 involve template parameters of the partial specialization except
2109 when the argument expression is a simple identifier.
2111 The type of a template parameter corresponding to a specialized
2112 non-type argument shall not be dependent on a parameter of the
2114 my_friendly_assert (nargs == DECL_NTPARMS (maintmpl), 0);
2116 for (i = 0; i < nargs; ++i)
2118 tree arg = TREE_VEC_ELT (inner_args, i);
2119 if (/* These first two lines are the `non-type' bit. */
2121 && TREE_CODE (arg) != TEMPLATE_DECL
2122 /* This next line is the `argument expression is not just a
2123 simple identifier' condition and also the `specialized
2124 non-type argument' bit. */
2125 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
2127 if (tpd.arg_uses_template_parms[i])
2128 cp_error ("template argument `%E' involves template parameter(s)", arg);
2131 /* Look at the corresponding template parameter,
2132 marking which template parameters its type depends
2135 TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (main_inner_parms,
2140 /* We haven't yet initialized TPD2. Do so now. */
2141 tpd2.arg_uses_template_parms
2142 = (int*) alloca (sizeof (int) * nargs);
2143 /* The number of parameters here is the number in the
2144 main template, which, as checked in the assertion
2146 tpd2.parms = (int*) alloca (sizeof (int) * nargs);
2148 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
2151 /* Mark the template parameters. But this time, we're
2152 looking for the template parameters of the main
2153 template, not in the specialization. */
2154 tpd2.current_arg = i;
2155 tpd2.arg_uses_template_parms[i] = 0;
2156 bzero ((PTR) tpd2.parms, sizeof (int) * nargs);
2157 for_each_template_parm (type,
2158 &mark_template_parm,
2161 if (tpd2.arg_uses_template_parms [i])
2163 /* The type depended on some template parameters.
2164 If they are fully specialized in the
2165 specialization, that's OK. */
2167 for (j = 0; j < nargs; ++j)
2168 if (tpd2.parms[j] != 0
2169 && tpd.arg_uses_template_parms [j])
2171 cp_error ("type `%T' of template argument `%E' depends on template parameter(s)",
2181 if (retrieve_specialization (maintmpl, specargs))
2182 /* We've already got this specialization. */
2185 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
2186 = tree_cons (inner_args, inner_parms,
2187 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
2188 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
2192 /* Check that a template declaration's use of default arguments is not
2193 invalid. Here, PARMS are the template parameters. IS_PRIMARY is
2194 non-zero if DECL is the thing declared by a primary template.
2195 IS_PARTIAL is non-zero if DECL is a partial specialization. */
2198 check_default_tmpl_args (decl, parms, is_primary, is_partial)
2205 int last_level_to_check;
2210 A default template-argument shall not be specified in a
2211 function template declaration or a function template definition, nor
2212 in the template-parameter-list of the definition of a member of a
2215 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
2216 /* You can't have a function template declaration in a local
2217 scope, nor you can you define a member of a class template in a
2221 if (current_class_type
2222 && !TYPE_BEING_DEFINED (current_class_type)
2223 && DECL_LANG_SPECIFIC (decl)
2224 /* If this is either a friend defined in the scope of the class
2225 or a member function. */
2226 && ((DECL_CONTEXT (decl)
2227 && same_type_p (DECL_CONTEXT (decl), current_class_type))
2228 || (DECL_FRIEND_CONTEXT (decl)
2229 && same_type_p (DECL_FRIEND_CONTEXT (decl),
2230 current_class_type)))
2231 /* And, if it was a member function, it really was defined in
2232 the scope of the class. */
2233 && (!DECL_FUNCTION_MEMBER_P (decl) || DECL_DEFINED_IN_CLASS_P (decl)))
2234 /* We already checked these parameters when the template was
2235 declared, so there's no need to do it again now. This function
2236 was defined in class scope, but we're processing it's body now
2237 that the class is complete. */
2242 If a template-parameter has a default template-argument, all
2243 subsequent template-parameters shall have a default
2244 template-argument supplied. */
2245 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
2247 tree inner_parms = TREE_VALUE (parm_level);
2248 int ntparms = TREE_VEC_LENGTH (inner_parms);
2249 int seen_def_arg_p = 0;
2252 for (i = 0; i < ntparms; ++i)
2254 tree parm = TREE_VEC_ELT (inner_parms, i);
2255 if (TREE_PURPOSE (parm))
2257 else if (seen_def_arg_p)
2259 cp_error ("no default argument for `%D'", TREE_VALUE (parm));
2260 /* For better subsequent error-recovery, we indicate that
2261 there should have been a default argument. */
2262 TREE_PURPOSE (parm) = error_mark_node;
2267 if (TREE_CODE (decl) != TYPE_DECL || is_partial || !is_primary)
2268 /* For an ordinary class template, default template arguments are
2269 allowed at the innermost level, e.g.:
2270 template <class T = int>
2272 but, in a partial specialization, they're not allowed even
2273 there, as we have in [temp.class.spec]:
2275 The template parameter list of a specialization shall not
2276 contain default template argument values.
2278 So, for a partial specialization, or for a function template,
2279 we look at all of them. */
2282 /* But, for a primary class template that is not a partial
2283 specialization we look at all template parameters except the
2285 parms = TREE_CHAIN (parms);
2287 /* Figure out what error message to issue. */
2288 if (TREE_CODE (decl) == FUNCTION_DECL)
2289 msg = "default argument for template parameter in function template `%D'";
2290 else if (is_partial)
2291 msg = "default argument in partial specialization `%D'";
2293 msg = "default argument for template parameter for class enclosing `%D'";
2295 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
2296 /* If we're inside a class definition, there's no need to
2297 examine the parameters to the class itself. On the one
2298 hand, they will be checked when the class is defined, and,
2299 on the other, default arguments are legal in things like:
2300 template <class T = double>
2301 struct S { template <class U> void f(U); };
2302 Here the default argument for `S' has no bearing on the
2303 declaration of `f'. */
2304 last_level_to_check = template_class_depth (current_class_type) + 1;
2306 /* Check everything. */
2307 last_level_to_check = 0;
2309 for (parm_level = parms;
2310 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
2311 parm_level = TREE_CHAIN (parm_level))
2313 tree inner_parms = TREE_VALUE (parm_level);
2317 ntparms = TREE_VEC_LENGTH (inner_parms);
2318 for (i = 0; i < ntparms; ++i)
2319 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
2323 cp_error (msg, decl);
2327 /* Clear out the default argument so that we are not
2329 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
2332 /* At this point, if we're still interested in issuing messages,
2333 they must apply to classes surrounding the object declared. */
2335 msg = "default argument for template parameter for class enclosing `%D'";
2339 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
2340 parameters given by current_template_args, or reuses a
2341 previously existing one, if appropriate. Returns the DECL, or an
2342 equivalent one, if it is replaced via a call to duplicate_decls.
2344 If IS_FRIEND is non-zero, DECL is a friend declaration. */
2347 push_template_decl_real (decl, is_friend)
2357 int new_template_p = 0;
2359 /* See if this is a partial specialization. */
2360 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
2361 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
2362 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
2364 is_friend |= (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl));
2367 /* For a friend, we want the context of the friend function, not
2368 the type of which it is a friend. */
2369 ctx = DECL_CONTEXT (decl);
2370 else if (CP_DECL_CONTEXT (decl)
2371 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
2372 /* In the case of a virtual function, we want the class in which
2374 ctx = CP_DECL_CONTEXT (decl);
2376 /* Otherwise, if we're currently definining some class, the DECL
2377 is assumed to be a member of the class. */
2378 ctx = current_scope ();
2380 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
2383 if (!DECL_CONTEXT (decl))
2384 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
2386 /* See if this is a primary template. */
2387 primary = template_parm_scope_p ();
2391 if (current_lang_name == lang_name_c)
2392 cp_error ("template with C linkage");
2393 else if (TREE_CODE (decl) == TYPE_DECL
2394 && ANON_AGGRNAME_P (DECL_NAME (decl)))
2395 cp_error ("template class without a name");
2396 else if ((DECL_IMPLICIT_TYPEDEF_P (decl)
2397 && CLASS_TYPE_P (TREE_TYPE (decl)))
2398 || (TREE_CODE (decl) == VAR_DECL && ctx && CLASS_TYPE_P (ctx))
2399 || TREE_CODE (decl) == FUNCTION_DECL)
2402 cp_error ("template declaration of `%#D'", decl);
2405 /* Check to see that the rules regarding the use of default
2406 arguments are not being violated. */
2407 check_default_tmpl_args (decl, current_template_parms,
2408 primary, is_partial);
2411 return process_partial_specialization (decl);
2413 args = current_template_args ();
2416 || TREE_CODE (ctx) == FUNCTION_DECL
2417 || TYPE_BEING_DEFINED (ctx)
2418 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
2420 if (DECL_LANG_SPECIFIC (decl)
2421 && DECL_TEMPLATE_INFO (decl)
2422 && DECL_TI_TEMPLATE (decl))
2423 tmpl = DECL_TI_TEMPLATE (decl);
2424 /* If DECL is a TYPE_DECL for a class-template, then there won't
2425 be DECL_LANG_SPECIFIC. The information equivalent to
2426 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
2427 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
2428 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
2429 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
2431 /* Since a template declaration already existed for this
2432 class-type, we must be redeclaring it here. Make sure
2433 that the redeclaration is legal. */
2434 redeclare_class_template (TREE_TYPE (decl),
2435 current_template_parms);
2436 /* We don't need to create a new TEMPLATE_DECL; just use the
2437 one we already had. */
2438 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
2442 tmpl = build_template_decl (decl, current_template_parms);
2445 if (DECL_LANG_SPECIFIC (decl)
2446 && DECL_TEMPLATE_SPECIALIZATION (decl))
2448 /* A specialization of a member template of a template
2450 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2451 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
2452 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
2458 tree a, t, current, parms;
2461 if (TREE_CODE (decl) == TYPE_DECL)
2463 if ((IS_AGGR_TYPE_CODE (TREE_CODE (TREE_TYPE (decl)))
2464 || TREE_CODE (TREE_TYPE (decl)) == ENUMERAL_TYPE)
2465 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
2466 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
2467 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
2470 cp_error ("`%D' does not declare a template type", decl);
2474 else if (! DECL_TEMPLATE_INFO (decl))
2476 cp_error ("template definition of non-template `%#D'", decl);
2480 tmpl = DECL_TI_TEMPLATE (decl);
2482 if (is_member_template (tmpl)
2483 && DECL_FUNCTION_TEMPLATE_P (tmpl)
2484 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
2485 && DECL_TEMPLATE_SPECIALIZATION (decl))
2489 /* The declaration is a specialization of a member
2490 template, declared outside the class. Therefore, the
2491 innermost template arguments will be NULL, so we
2492 replace them with the arguments determined by the
2493 earlier call to check_explicit_specialization. */
2494 args = DECL_TI_ARGS (decl);
2497 = build_template_decl (decl, current_template_parms);
2498 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
2499 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
2500 DECL_TI_TEMPLATE (decl) = new_tmpl;
2501 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
2502 DECL_TEMPLATE_INFO (new_tmpl)
2503 = tree_cons (tmpl, args, NULL_TREE);
2505 register_specialization (new_tmpl, tmpl, args);
2509 /* Make sure the template headers we got make sense. */
2511 parms = DECL_TEMPLATE_PARMS (tmpl);
2512 i = TMPL_PARMS_DEPTH (parms);
2513 if (TMPL_ARGS_DEPTH (args) != i)
2515 cp_error ("expected %d levels of template parms for `%#D', got %d",
2516 i, decl, TMPL_ARGS_DEPTH (args));
2519 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
2521 a = TMPL_ARGS_LEVEL (args, i);
2522 t = INNERMOST_TEMPLATE_PARMS (parms);
2524 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
2526 if (current == decl)
2527 cp_error ("got %d template parameters for `%#D'",
2528 TREE_VEC_LENGTH (a), decl);
2530 cp_error ("got %d template parameters for `%#T'",
2531 TREE_VEC_LENGTH (a), current);
2532 cp_error (" but %d required", TREE_VEC_LENGTH (t));
2535 /* Perhaps we should also check that the parms are used in the
2536 appropriate qualifying scopes in the declarator? */
2538 if (current == decl)
2541 current = TYPE_CONTEXT (current);
2545 DECL_TEMPLATE_RESULT (tmpl) = decl;
2546 TREE_TYPE (tmpl) = TREE_TYPE (decl);
2548 /* Push template declarations for global functions and types. Note
2549 that we do not try to push a global template friend declared in a
2550 template class; such a thing may well depend on the template
2551 parameters of the class. */
2552 if (new_template_p && !ctx
2553 && !(is_friend && template_class_depth (current_class_type) > 0))
2554 tmpl = pushdecl_namespace_level (tmpl);
2557 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
2559 info = tree_cons (tmpl, args, NULL_TREE);
2561 if (DECL_IMPLICIT_TYPEDEF_P (decl))
2563 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
2564 if ((!ctx || TREE_CODE (ctx) != FUNCTION_DECL)
2565 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE)
2566 DECL_NAME (decl) = classtype_mangled_name (TREE_TYPE (decl));
2568 else if (DECL_LANG_SPECIFIC (decl))
2569 DECL_TEMPLATE_INFO (decl) = info;
2571 return DECL_TEMPLATE_RESULT (tmpl);
2575 push_template_decl (decl)
2578 return push_template_decl_real (decl, 0);
2581 /* Called when a class template TYPE is redeclared with the indicated
2582 template PARMS, e.g.:
2584 template <class T> struct S;
2585 template <class T> struct S {}; */
2588 redeclare_class_template (type, parms)
2596 if (!TYPE_TEMPLATE_INFO (type))
2598 cp_error ("`%T' is not a template type", type);
2602 tmpl = TYPE_TI_TEMPLATE (type);
2603 if (!PRIMARY_TEMPLATE_P (tmpl))
2604 /* The type is nested in some template class. Nothing to worry
2605 about here; there are no new template parameters for the nested
2609 parms = INNERMOST_TEMPLATE_PARMS (parms);
2610 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
2612 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
2614 cp_error_at ("previous declaration `%D'", tmpl);
2615 cp_error ("used %d template parameter%s instead of %d",
2616 TREE_VEC_LENGTH (tmpl_parms),
2617 TREE_VEC_LENGTH (tmpl_parms) == 1 ? "" : "s",
2618 TREE_VEC_LENGTH (parms));
2622 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
2624 tree tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
2625 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
2626 tree tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
2627 tree parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
2629 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm))
2631 cp_error_at ("template parameter `%#D'", tmpl_parm);
2632 cp_error ("redeclared here as `%#D'", parm);
2636 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
2638 /* We have in [temp.param]:
2640 A template-parameter may not be given default arguments
2641 by two different declarations in the same scope. */
2642 cp_error ("redefinition of default argument for `%#D'", parm);
2643 cp_error_at (" original definition appeared here", tmpl_parm);
2647 if (parm_default != NULL_TREE)
2648 /* Update the previous template parameters (which are the ones
2649 that will really count) with the new default value. */
2650 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
2651 else if (tmpl_default != NULL_TREE)
2652 /* Update the new parameters, too; they'll be used as the
2653 parameters for any members. */
2654 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
2658 /* Attempt to convert the non-type template parameter EXPR to the
2659 indicated TYPE. If the conversion is successful, return the
2660 converted value. If the conversion is unsuccesful, return
2661 NULL_TREE if we issued an error message, or error_mark_node if we
2662 did not. We issue error messages for out-and-out bad template
2663 parameters, but not simply because the conversion failed, since we
2664 might be just trying to do argument deduction. By the time this
2665 function is called, neither TYPE nor EXPR may make use of template
2669 convert_nontype_argument (type, expr)
2673 tree expr_type = TREE_TYPE (expr);
2675 /* A template-argument for a non-type, non-template
2676 template-parameter shall be one of:
2678 --an integral constant-expression of integral or enumeration
2681 --the name of a non-type template-parameter; or
2683 --the name of an object or function with external linkage,
2684 including function templates and function template-ids but
2685 excluding non-static class members, expressed as id-expression;
2688 --the address of an object or function with external linkage,
2689 including function templates and function template-ids but
2690 excluding non-static class members, expressed as & id-expression
2691 where the & is optional if the name refers to a function or
2694 --a pointer to member expressed as described in _expr.unary.op_. */
2696 /* An integral constant-expression can include const variables or
2697 enumerators. Simplify things by folding them to their values,
2698 unless we're about to bind the declaration to a reference
2700 if (INTEGRAL_TYPE_P (expr_type) && TREE_READONLY_DECL_P (expr)
2701 && TREE_CODE (type) != REFERENCE_TYPE)
2702 expr = decl_constant_value (expr);
2704 if (is_overloaded_fn (expr))
2705 /* OK for now. We'll check that it has external linkage later.
2706 Check this first since if expr_type is the unknown_type_node
2707 we would otherwise complain below. */
2709 else if (TYPE_PTRMEM_P (expr_type)
2710 || TYPE_PTRMEMFUNC_P (expr_type))
2712 if (TREE_CODE (expr) != PTRMEM_CST)
2715 else if (TYPE_PTR_P (expr_type)
2716 || TYPE_PTRMEM_P (expr_type)
2717 || TREE_CODE (expr_type) == ARRAY_TYPE
2718 || TREE_CODE (type) == REFERENCE_TYPE
2719 /* If expr is the address of an overloaded function, we
2720 will get the unknown_type_node at this point. */
2721 || expr_type == unknown_type_node)
2727 if (TREE_CODE (type) == REFERENCE_TYPE
2728 || TREE_CODE (expr_type) == ARRAY_TYPE)
2732 if (TREE_CODE (e) != ADDR_EXPR)
2735 cp_error ("`%E' is not a valid template argument", expr);
2736 if (TYPE_PTR_P (expr_type))
2738 if (TREE_CODE (TREE_TYPE (expr_type)) == FUNCTION_TYPE)
2739 cp_error ("it must be the address of a function with external linkage");
2741 cp_error ("it must be the address of an object with external linkage");
2743 else if (TYPE_PTRMEM_P (expr_type)
2744 || TYPE_PTRMEMFUNC_P (expr_type))
2745 cp_error ("it must be a pointer-to-member of the form `&X::Y'");
2750 referent = TREE_OPERAND (e, 0);
2751 STRIP_NOPS (referent);
2754 if (TREE_CODE (referent) == STRING_CST)
2756 cp_error ("string literal %E is not a valid template argument because it is the address of an object with static linkage",
2761 if (is_overloaded_fn (referent))
2762 /* We'll check that it has external linkage later. */
2764 else if (TREE_CODE (referent) != VAR_DECL)
2766 else if (!TREE_PUBLIC (referent))
2768 cp_error ("address of non-extern `%E' cannot be used as template argument", referent);
2769 return error_mark_node;
2772 else if (INTEGRAL_TYPE_P (expr_type)
2773 || TYPE_PTRMEM_P (expr_type)
2774 || TYPE_PTRMEMFUNC_P (expr_type)
2775 /* The next two are g++ extensions. */
2776 || TREE_CODE (expr_type) == REAL_TYPE
2777 || TREE_CODE (expr_type) == COMPLEX_TYPE)
2779 if (! TREE_CONSTANT (expr))
2782 cp_error ("non-constant `%E' cannot be used as template argument",
2789 cp_error ("object `%E' cannot be used as template argument", expr);
2793 switch (TREE_CODE (type))
2798 /* For a non-type template-parameter of integral or enumeration
2799 type, integral promotions (_conv.prom_) and integral
2800 conversions (_conv.integral_) are applied. */
2801 if (!INTEGRAL_TYPE_P (expr_type))
2802 return error_mark_node;
2804 /* It's safe to call digest_init in this case; we know we're
2805 just converting one integral constant expression to another. */
2806 expr = digest_init (type, expr, (tree*) 0);
2808 if (TREE_CODE (expr) != INTEGER_CST)
2809 /* Curiously, some TREE_CONSTANT integral expressions do not
2810 simplify to integer constants. For example, `3 % 0',
2811 remains a TRUNC_MOD_EXPR. */
2818 /* These are g++ extensions. */
2819 if (TREE_CODE (expr_type) != TREE_CODE (type))
2820 return error_mark_node;
2822 expr = digest_init (type, expr, (tree*) 0);
2824 if (TREE_CODE (expr) != REAL_CST)
2831 tree type_pointed_to = TREE_TYPE (type);
2833 if (TYPE_PTRMEM_P (type))
2837 /* For a non-type template-parameter of type pointer to data
2838 member, qualification conversions (_conv.qual_) are
2840 e = perform_qualification_conversions (type, expr);
2841 if (TREE_CODE (e) == NOP_EXPR)
2842 /* The call to perform_qualification_conversions will
2843 insert a NOP_EXPR over EXPR to do express conversion,
2844 if necessary. But, that will confuse us if we use
2845 this (converted) template parameter to instantiate
2846 another template; then the thing will not look like a
2847 valid template argument. So, just make a new
2848 constant, of the appropriate type. */
2849 e = make_ptrmem_cst (type, PTRMEM_CST_MEMBER (expr));
2852 else if (TREE_CODE (type_pointed_to) == FUNCTION_TYPE)
2854 /* For a non-type template-parameter of type pointer to
2855 function, only the function-to-pointer conversion
2856 (_conv.func_) is applied. If the template-argument
2857 represents a set of overloaded functions (or a pointer to
2858 such), the matching function is selected from the set
2863 if (TREE_CODE (expr) == ADDR_EXPR)
2864 fns = TREE_OPERAND (expr, 0);
2868 fn = instantiate_type (type_pointed_to, fns, 0);
2870 if (fn == error_mark_node)
2871 return error_mark_node;
2873 if (!TREE_PUBLIC (fn))
2875 if (really_overloaded_fn (fns))
2876 return error_mark_node;
2881 expr = build_unary_op (ADDR_EXPR, fn, 0);
2883 my_friendly_assert (same_type_p (type, TREE_TYPE (expr)),
2889 /* For a non-type template-parameter of type pointer to
2890 object, qualification conversions (_conv.qual_) and the
2891 array-to-pointer conversion (_conv.array_) are applied.
2892 [Note: In particular, neither the null pointer conversion
2893 (_conv.ptr_) nor the derived-to-base conversion
2894 (_conv.ptr_) are applied. Although 0 is a valid
2895 template-argument for a non-type template-parameter of
2896 integral type, it is not a valid template-argument for a
2897 non-type template-parameter of pointer type.]
2899 The call to decay_conversion performs the
2900 array-to-pointer conversion, if appropriate. */
2901 expr = decay_conversion (expr);
2903 if (expr == error_mark_node)
2904 return error_mark_node;
2906 return perform_qualification_conversions (type, expr);
2911 case REFERENCE_TYPE:
2913 tree type_referred_to = TREE_TYPE (type);
2915 if (TREE_CODE (type_referred_to) == FUNCTION_TYPE)
2917 /* For a non-type template-parameter of type reference to
2918 function, no conversions apply. If the
2919 template-argument represents a set of overloaded
2920 functions, the matching function is selected from the
2921 set (_over.over_). */
2925 fn = instantiate_type (type_referred_to, fns, 0);
2927 if (fn == error_mark_node)
2928 return error_mark_node;
2930 if (!TREE_PUBLIC (fn))
2932 if (really_overloaded_fn (fns))
2933 /* Don't issue an error here; we might get a different
2934 function if the overloading had worked out
2936 return error_mark_node;
2941 my_friendly_assert (same_type_p (type_referred_to,
2949 /* For a non-type template-parameter of type reference to
2950 object, no conversions apply. The type referred to by the
2951 reference may be more cv-qualified than the (otherwise
2952 identical) type of the template-argument. The
2953 template-parameter is bound directly to the
2954 template-argument, which must be an lvalue. */
2955 if ((TYPE_MAIN_VARIANT (expr_type)
2956 != TYPE_MAIN_VARIANT (type_referred_to))
2957 || !at_least_as_qualified_p (type_referred_to,
2959 || !real_lvalue_p (expr))
2960 return error_mark_node;
2969 if (!TYPE_PTRMEMFUNC_P (type))
2970 /* This handles templates like
2971 template<class T, T t> void f();
2972 when T is substituted with any class. The second template
2973 parameter becomes invalid and the template candidate is
2975 return error_mark_node;
2977 /* For a non-type template-parameter of type pointer to member
2978 function, no conversions apply. If the template-argument
2979 represents a set of overloaded member functions, the
2980 matching member function is selected from the set
2983 if (!TYPE_PTRMEMFUNC_P (expr_type) &&
2984 expr_type != unknown_type_node)
2985 return error_mark_node;
2987 if (TREE_CODE (expr) == PTRMEM_CST)
2989 /* A ptr-to-member constant. */
2990 if (!same_type_p (type, expr_type))
2991 return error_mark_node;
2996 if (TREE_CODE (expr) != ADDR_EXPR)
2997 return error_mark_node;
2999 expr = instantiate_type (type, expr, 0);
3001 if (expr == error_mark_node)
3002 return error_mark_node;
3004 my_friendly_assert (same_type_p (type, TREE_TYPE (expr)),
3011 /* All non-type parameters must have one of these types. */
3012 my_friendly_abort (0);
3016 return error_mark_node;
3019 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
3020 template template parameters. Both PARM_PARMS and ARG_PARMS are
3021 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
3024 ARG_PARMS may contain more parameters than PARM_PARMS. If this is
3025 the case, then extra parameters must have default arguments.
3027 Consider the example:
3028 template <class T, class Allocator = allocator> class vector;
3029 template<template <class U> class TT> class C;
3031 C<vector> is a valid instantiation. PARM_PARMS for the above code
3032 contains a TYPE_DECL (for U), ARG_PARMS contains two TYPE_DECLs (for
3033 T and Allocator) and OUTER_ARGS contains the argument that is used to
3034 substitute the TT parameter. */
3037 coerce_template_template_parms (parm_parms, arg_parms, complain,
3038 in_decl, outer_args)
3039 tree parm_parms, arg_parms;
3041 tree in_decl, outer_args;
3043 int nparms, nargs, i;
3046 my_friendly_assert (TREE_CODE (parm_parms) == TREE_VEC, 0);
3047 my_friendly_assert (TREE_CODE (arg_parms) == TREE_VEC, 0);
3049 nparms = TREE_VEC_LENGTH (parm_parms);
3050 nargs = TREE_VEC_LENGTH (arg_parms);
3052 /* The rule here is opposite of coerce_template_parms. */
3055 && TREE_PURPOSE (TREE_VEC_ELT (arg_parms, nparms)) == NULL_TREE))
3058 for (i = 0; i < nparms; ++i)
3060 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
3061 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
3063 if (arg == NULL_TREE || arg == error_mark_node
3064 || parm == NULL_TREE || parm == error_mark_node)
3067 if (TREE_CODE (arg) != TREE_CODE (parm))
3070 switch (TREE_CODE (parm))
3076 /* We encounter instantiations of templates like
3077 template <template <template <class> class> class TT>
3080 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
3081 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
3083 if (!coerce_template_template_parms (parmparm, argparm,
3091 /* The tsubst call is used to handle cases such as
3092 template <class T, template <T> class TT> class D;
3093 i.e. the parameter list of TT depends on earlier parameters. */
3094 if (!same_type_p (tsubst (TREE_TYPE (parm), outer_args,
3101 my_friendly_abort (0);
3107 /* Convert the indicated template ARG as necessary to match the
3108 indicated template PARM. Returns the converted ARG, or
3109 error_mark_node if the conversion was unsuccessful. Error messages
3110 are issued if COMPLAIN is non-zero. This conversion is for the Ith
3111 parameter in the parameter list. ARGS is the full set of template
3112 arguments deduced so far. */
3115 convert_template_argument (parm, arg, args, complain, i, in_decl)
3125 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
3127 inner_args = innermost_args (args);
3129 if (TREE_CODE (arg) == TREE_LIST
3130 && TREE_TYPE (arg) != NULL_TREE
3131 && TREE_CODE (TREE_TYPE (arg)) == OFFSET_TYPE)
3133 /* The template argument was the name of some
3134 member function. That's usually
3135 illegal, but static members are OK. In any
3136 case, grab the underlying fields/functions
3137 and issue an error later if required. */
3138 arg = TREE_VALUE (arg);
3139 TREE_TYPE (arg) = unknown_type_node;
3142 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
3143 requires_type = (TREE_CODE (parm) == TYPE_DECL
3144 || requires_tmpl_type);
3146 /* Check if it is a class template. If REQUIRES_TMPL_TYPE is true,
3147 we also accept implicitly created TYPE_DECL as a valid argument.
3148 This is necessary to handle the case where we pass a template name
3149 to a template template parameter in a scope where we've derived from
3150 in instantiation of that template, so the template name refers to that
3151 instantiation. We really ought to handle this better. */
3153 = ((TREE_CODE (arg) == TEMPLATE_DECL
3154 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
3155 || (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
3156 && !TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (arg))
3157 || (TREE_CODE (arg) == RECORD_TYPE
3158 && CLASSTYPE_TEMPLATE_INFO (arg)
3159 && TREE_CODE (TYPE_NAME (arg)) == TYPE_DECL
3160 && DECL_ARTIFICIAL (TYPE_NAME (arg))
3161 && requires_tmpl_type
3162 && is_base_of_enclosing_class (arg, current_class_type)));
3163 if (is_tmpl_type && TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
3164 arg = TYPE_STUB_DECL (arg);
3165 else if (is_tmpl_type && TREE_CODE (arg) == RECORD_TYPE)
3166 arg = CLASSTYPE_TI_TEMPLATE (arg);
3168 is_type = TYPE_P (arg) || is_tmpl_type;
3170 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
3171 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
3173 cp_pedwarn ("to refer to a type member of a template parameter, use `typename %E'", arg);
3175 arg = make_typename_type (TREE_OPERAND (arg, 0),
3176 TREE_OPERAND (arg, 1),
3180 if (is_type != requires_type)
3186 cp_error ("type/value mismatch at argument %d in template parameter list for `%D'",
3189 cp_error (" expected a constant of type `%T', got `%T'",
3191 (is_tmpl_type ? DECL_NAME (arg) : arg));
3193 cp_error (" expected a type, got `%E'", arg);
3196 return error_mark_node;
3198 if (is_tmpl_type ^ requires_tmpl_type)
3200 if (in_decl && complain)
3202 cp_error ("type/value mismatch at argument %d in template parameter list for `%D'",
3205 cp_error (" expected a type, got `%T'", DECL_NAME (arg));
3207 cp_error (" expected a class template, got `%T'", arg);
3209 return error_mark_node;
3214 if (requires_tmpl_type)
3216 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
3217 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
3219 if (coerce_template_template_parms (parmparm, argparm, complain,
3220 in_decl, inner_args))
3224 /* TEMPLATE_TEMPLATE_PARM node is preferred over
3226 if (val != error_mark_node
3227 && DECL_TEMPLATE_TEMPLATE_PARM_P (val))
3228 val = TREE_TYPE (val);
3232 if (in_decl && complain)
3234 cp_error ("type/value mismatch at argument %d in template parameter list for `%D'",
3236 cp_error (" expected a template of type `%D', got `%D'", parm, arg);
3239 val = error_mark_node;
3244 val = groktypename (arg);
3245 if (! processing_template_decl)
3247 /* [basic.link]: A name with no linkage (notably, the
3248 name of a class or enumeration declared in a local
3249 scope) shall not be used to declare an entity with
3250 linkage. This implies that names with no linkage
3251 cannot be used as template arguments. */
3252 tree t = no_linkage_check (val);
3255 if (ANON_AGGRNAME_P (TYPE_IDENTIFIER (t)))
3257 ("template-argument `%T' uses anonymous type", val);
3260 ("template-argument `%T' uses local type `%T'",
3262 return error_mark_node;
3269 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
3271 if (processing_template_decl)
3272 arg = maybe_fold_nontype_arg (arg);
3274 if (!uses_template_parms (arg) && !uses_template_parms (t))
3275 /* We used to call digest_init here. However, digest_init
3276 will report errors, which we don't want when complain
3277 is zero. More importantly, digest_init will try too
3278 hard to convert things: for example, `0' should not be
3279 converted to pointer type at this point according to
3280 the standard. Accepting this is not merely an
3281 extension, since deciding whether or not these
3282 conversions can occur is part of determining which
3283 function template to call, or whether a given epxlicit
3284 argument specification is legal. */
3285 val = convert_nontype_argument (t, arg);
3289 if (val == NULL_TREE)
3290 val = error_mark_node;
3291 else if (val == error_mark_node && complain)
3292 cp_error ("could not convert template argument `%E' to `%T'",
3299 /* Convert all template arguments to their appropriate types, and
3300 return a vector containing the innermost resulting template
3301 arguments. If any error occurs, return error_mark_node, and, if
3302 COMPLAIN is non-zero, issue an error message. Some error messages
3303 are issued even if COMPLAIN is zero; for instance, if a template
3304 argument is composed from a local class.
3306 If REQUIRE_ALL_ARGUMENTS is non-zero, all arguments must be
3307 provided in ARGLIST, or else trailing parameters must have default
3308 values. If REQUIRE_ALL_ARGUMENTS is zero, we will attempt argument
3309 deduction for any unspecified trailing arguments.
3311 The resulting TREE_VEC is allocated on a temporary obstack, and
3312 must be explicitly copied if it will be permanent. */
3315 coerce_template_parms (parms, args, in_decl,
3317 require_all_arguments)
3321 int require_all_arguments;
3323 int nparms, nargs, i, lost = 0;
3326 tree new_inner_args;
3328 inner_args = innermost_args (args);
3329 nargs = NUM_TMPL_ARGS (inner_args);
3330 nparms = TREE_VEC_LENGTH (parms);
3334 && require_all_arguments
3335 && TREE_PURPOSE (TREE_VEC_ELT (parms, nargs)) == NULL_TREE))
3339 cp_error ("wrong number of template arguments (%d, should be %d)",
3343 cp_error_at ("provided for `%D'", in_decl);
3346 return error_mark_node;
3349 new_inner_args = make_tree_vec (nparms);
3350 new_args = add_outermost_template_args (args, new_inner_args);
3351 for (i = 0; i < nparms; i++)
3356 /* Get the Ith template parameter. */
3357 parm = TREE_VEC_ELT (parms, i);
3359 /* Calculate the Ith argument. */
3360 if (inner_args && TREE_CODE (inner_args) == TREE_LIST)
3362 arg = TREE_VALUE (inner_args);
3363 inner_args = TREE_CHAIN (inner_args);
3366 arg = TREE_VEC_ELT (inner_args, i);
3367 /* If no template argument was supplied, look for a default
3369 else if (TREE_PURPOSE (parm) == NULL_TREE)
3371 /* There was no default value. */
3372 my_friendly_assert (!require_all_arguments, 0);
3375 else if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL)
3376 arg = tsubst (TREE_PURPOSE (parm), new_args, complain, in_decl);
3378 arg = tsubst_expr (TREE_PURPOSE (parm), new_args, complain,
3381 /* Now, convert the Ith argument, as necessary. */
3382 if (arg == NULL_TREE)
3383 /* We're out of arguments. */
3385 my_friendly_assert (!require_all_arguments, 0);
3388 else if (arg == error_mark_node)
3390 cp_error ("template argument %d is invalid", i + 1);
3391 arg = error_mark_node;
3394 arg = convert_template_argument (TREE_VALUE (parm),
3395 arg, new_args, complain, i,
3398 if (arg == error_mark_node)
3400 TREE_VEC_ELT (new_inner_args, i) = arg;
3404 return error_mark_node;
3406 return new_inner_args;
3409 /* Returns 1 if template args OT and NT are equivalent. */
3412 template_args_equal (ot, nt)
3417 if (TREE_CODE (nt) != TREE_CODE (ot))
3419 if (TREE_CODE (nt) == TREE_VEC)
3420 /* For member templates */
3421 return comp_template_args (ot, nt);
3422 else if (TYPE_P (ot))
3423 return same_type_p (ot, nt);
3425 return (cp_tree_equal (ot, nt) > 0);
3428 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
3429 of template arguments. Returns 0 otherwise. */
3432 comp_template_args (oldargs, newargs)
3433 tree oldargs, newargs;
3437 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
3440 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
3442 tree nt = TREE_VEC_ELT (newargs, i);
3443 tree ot = TREE_VEC_ELT (oldargs, i);
3445 if (! template_args_equal (ot, nt))
3451 /* Given class template name and parameter list, produce a user-friendly name
3452 for the instantiation. */
3455 mangle_class_name_for_template (name, parms, arglist)
3457 tree parms, arglist;
3459 static struct obstack scratch_obstack;
3460 static char *scratch_firstobj;
3463 if (!scratch_firstobj)
3464 gcc_obstack_init (&scratch_obstack);
3466 obstack_free (&scratch_obstack, scratch_firstobj);
3467 scratch_firstobj = obstack_alloc (&scratch_obstack, 1);
3469 #define ccat(c) obstack_1grow (&scratch_obstack, (c));
3470 #define cat(s) obstack_grow (&scratch_obstack, (s), strlen (s))
3474 nparms = TREE_VEC_LENGTH (parms);
3475 arglist = innermost_args (arglist);
3476 my_friendly_assert (nparms == TREE_VEC_LENGTH (arglist), 268);
3477 for (i = 0; i < nparms; i++)
3479 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
3480 tree arg = TREE_VEC_ELT (arglist, i);
3485 if (TREE_CODE (parm) == TYPE_DECL)
3487 cat (type_as_string (arg, TS_CHASE_TYPEDEFS));
3490 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3492 if (TREE_CODE (arg) == TEMPLATE_DECL)
3494 /* Already substituted with real template. Just output
3495 the template name here */
3496 tree context = DECL_CONTEXT (arg);
3499 /* The template may be defined in a namespace, or
3500 may be a member template. */
3501 my_friendly_assert (TREE_CODE (context) == NAMESPACE_DECL
3502 || CLASS_TYPE_P (context),
3504 cat(decl_as_string (DECL_CONTEXT (arg), 0));
3507 cat (IDENTIFIER_POINTER (DECL_NAME (arg)));
3510 /* Output the parameter declaration */
3511 cat (type_as_string (arg, TS_CHASE_TYPEDEFS));
3515 my_friendly_assert (TREE_CODE (parm) == PARM_DECL, 269);
3517 if (TREE_CODE (arg) == TREE_LIST)
3519 /* New list cell was built because old chain link was in
3521 my_friendly_assert (TREE_PURPOSE (arg) == NULL_TREE, 270);
3522 arg = TREE_VALUE (arg);
3524 /* No need to check arglist against parmlist here; we did that
3525 in coerce_template_parms, called from lookup_template_class. */
3526 cat (expr_as_string (arg, 0));
3529 char *bufp = obstack_next_free (&scratch_obstack);
3531 while (bufp[offset - 1] == ' ')
3533 obstack_blank_fast (&scratch_obstack, offset);
3535 /* B<C<char> >, not B<C<char>> */
3536 if (bufp[offset - 1] == '>')
3541 return (char *) obstack_base (&scratch_obstack);
3545 classtype_mangled_name (t)
3548 if (CLASSTYPE_TEMPLATE_INFO (t)
3549 /* Specializations have already had their names set up in
3550 lookup_template_class. */
3551 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
3553 tree tmpl = most_general_template (CLASSTYPE_TI_TEMPLATE (t));
3555 /* For non-primary templates, the template parameters are
3556 implicit from their surrounding context. */
3557 if (PRIMARY_TEMPLATE_P (tmpl))
3559 tree name = DECL_NAME (tmpl);
3560 char *mangled_name = mangle_class_name_for_template
3561 (IDENTIFIER_POINTER (name),
3562 DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
3563 CLASSTYPE_TI_ARGS (t));
3564 tree id = get_identifier (mangled_name);
3565 IDENTIFIER_TEMPLATE (id) = name;
3570 return TYPE_IDENTIFIER (t);
3574 add_pending_template (d)
3577 tree ti = (TYPE_P (d)) ? CLASSTYPE_TEMPLATE_INFO (d) : DECL_TEMPLATE_INFO (d);
3579 if (TI_PENDING_TEMPLATE_FLAG (ti))
3582 *template_tail = tree_cons (build_srcloc_here (), d, NULL_TREE);
3583 template_tail = &TREE_CHAIN (*template_tail);
3584 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
3588 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS (which
3589 may be either a _DECL or an overloaded function or an
3590 IDENTIFIER_NODE), and ARGLIST. */
3593 lookup_template_function (fns, arglist)
3598 if (fns == NULL_TREE)
3600 cp_error ("non-template used as template");
3601 return error_mark_node;
3604 type = TREE_TYPE (fns);
3605 if (TREE_CODE (fns) == OVERLOAD || !type)
3606 type = unknown_type_node;
3608 if (processing_template_decl)
3609 return build_min (TEMPLATE_ID_EXPR, type, fns, arglist);
3611 return build (TEMPLATE_ID_EXPR, type, fns, arglist);
3614 /* Within the scope of a template class S<T>, the name S gets bound
3615 (in build_self_reference) to a TYPE_DECL for the class, not a
3616 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
3617 or one of its enclosing classes, and that type is a template,
3618 return the associated TEMPLATE_DECL. Otherwise, the original
3619 DECL is returned. */
3622 maybe_get_template_decl_from_type_decl (decl)
3625 return (decl != NULL_TREE
3626 && TREE_CODE (decl) == TYPE_DECL
3627 && DECL_ARTIFICIAL (decl)
3628 && CLASS_TYPE_P (TREE_TYPE (decl))
3629 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
3630 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
3633 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
3634 parameters, find the desired type.
3636 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
3637 (Actually ARGLIST may be either a TREE_LIST or a TREE_VEC. It will
3638 be a TREE_LIST if called directly from the parser, and a TREE_VEC
3639 otherwise.) Since ARGLIST is build on the temp_decl_obstack, we must
3640 copy it here to keep it from being reclaimed when the decl storage
3643 IN_DECL, if non-NULL, is the template declaration we are trying to
3646 If ENTERING_SCOPE is non-zero, we are about to enter the scope of
3647 the class we are looking up.
3649 If the template class is really a local class in a template
3650 function, then the FUNCTION_CONTEXT is the function in which it is
3651 being instantiated. */
3654 lookup_template_class (d1, arglist, in_decl, context, entering_scope)
3660 tree template = NULL_TREE, parmlist;
3663 if (TREE_CODE (d1) == IDENTIFIER_NODE)
3665 if (IDENTIFIER_VALUE (d1)
3666 && DECL_TEMPLATE_TEMPLATE_PARM_P (IDENTIFIER_VALUE (d1)))
3667 template = IDENTIFIER_VALUE (d1);
3671 push_decl_namespace (context);
3672 template = lookup_name (d1, /*prefer_type=*/0);
3673 template = maybe_get_template_decl_from_type_decl (template);
3675 pop_decl_namespace ();
3678 context = DECL_CONTEXT (template);
3680 else if (TREE_CODE (d1) == TYPE_DECL && IS_AGGR_TYPE (TREE_TYPE (d1)))
3682 tree type = TREE_TYPE (d1);
3684 /* If we are declaring a constructor, say A<T>::A<T>, we will get
3685 an implicit typename for the second A. Deal with it. */
3686 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
3687 type = TREE_TYPE (type);
3689 if (CLASSTYPE_TEMPLATE_INFO (type))
3691 template = CLASSTYPE_TI_TEMPLATE (type);
3692 d1 = DECL_NAME (template);
3695 else if (TREE_CODE (d1) == ENUMERAL_TYPE
3696 || (TYPE_P (d1) && IS_AGGR_TYPE (d1)))
3698 template = TYPE_TI_TEMPLATE (d1);
3699 d1 = DECL_NAME (template);
3701 else if (TREE_CODE (d1) == TEMPLATE_DECL
3702 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
3705 d1 = DECL_NAME (template);
3706 context = DECL_CONTEXT (template);
3709 my_friendly_abort (272);
3711 /* With something like `template <class T> class X class X { ... };'
3712 we could end up with D1 having nothing but an IDENTIFIER_VALUE.
3713 We don't want to do that, but we have to deal with the situation,
3714 so let's give them some syntax errors to chew on instead of a
3718 cp_error ("`%T' is not a template", d1);
3719 return error_mark_node;
3722 if (context == NULL_TREE)
3723 context = global_namespace;
3725 if (TREE_CODE (template) != TEMPLATE_DECL)
3727 cp_error ("non-template type `%T' used as a template", d1);
3729 cp_error_at ("for template declaration `%D'", in_decl);
3730 return error_mark_node;
3733 if (DECL_TEMPLATE_TEMPLATE_PARM_P (template))
3735 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
3736 template arguments */
3738 tree parm = copy_template_template_parm (TREE_TYPE (template));
3739 tree template2 = TYPE_STUB_DECL (parm);
3742 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (template);
3744 arglist2 = coerce_template_parms (parmlist, arglist, template, 1, 1);
3745 if (arglist2 == error_mark_node)
3746 return error_mark_node;
3748 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (parm)
3749 = tree_cons (template2, arglist2, NULL_TREE);
3750 TYPE_SIZE (parm) = 0;
3755 tree template_type = TREE_TYPE (template);
3758 tree found = NULL_TREE;
3761 int is_partial_instantiation;
3763 gen_tmpl = most_general_template (template);
3764 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
3765 parm_depth = TMPL_PARMS_DEPTH (parmlist);
3766 arg_depth = TMPL_ARGS_DEPTH (arglist);
3768 if (arg_depth == 1 && parm_depth > 1)
3770 /* We've been given an incomplete set of template arguments.
3773 template <class T> struct S1 {
3774 template <class U> struct S2 {};
3775 template <class U> struct S2<U*> {};
3778 we will be called with an ARGLIST of `U*', but the
3779 TEMPLATE will be `template <class T> template
3780 <class U> struct S1<T>::S2'. We must fill in the missing
3783 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (template)),
3785 arg_depth = TMPL_ARGS_DEPTH (arglist);
3788 /* Now we should enough arguments. */
3789 my_friendly_assert (parm_depth == arg_depth, 0);
3791 /* From here on, we're only interested in the most general
3793 template = gen_tmpl;
3795 /* Calculate the BOUND_ARGS. These will be the args that are
3796 actually tsubst'd into the definition to create the
3800 /* We have multiple levels of arguments to coerce, at once. */
3802 int saved_depth = TMPL_ARGS_DEPTH (arglist);
3804 tree bound_args = make_tree_vec (parm_depth);
3806 for (i = saved_depth,
3807 t = DECL_TEMPLATE_PARMS (template);
3808 i > 0 && t != NULL_TREE;
3809 --i, t = TREE_CHAIN (t))
3811 tree a = coerce_template_parms (TREE_VALUE (t),
3812 arglist, template, 1, 1);
3813 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
3815 /* We temporarily reduce the length of the ARGLIST so
3816 that coerce_template_parms will see only the arguments
3817 corresponding to the template parameters it is
3819 TREE_VEC_LENGTH (arglist)--;
3822 /* Restore the ARGLIST to its full size. */
3823 TREE_VEC_LENGTH (arglist) = saved_depth;
3825 arglist = bound_args;
3829 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
3830 innermost_args (arglist),
3833 if (arglist == error_mark_node)
3834 /* We were unable to bind the arguments. */
3835 return error_mark_node;
3837 /* In the scope of a template class, explicit references to the
3838 template class refer to the type of the template, not any
3839 instantiation of it. For example, in:
3841 template <class T> class C { void f(C<T>); }
3843 the `C<T>' is just the same as `C'. Outside of the
3844 class, however, such a reference is an instantiation. */
3845 if (comp_template_args (TYPE_TI_ARGS (template_type),
3848 found = template_type;
3850 if (!entering_scope && PRIMARY_TEMPLATE_P (template))
3854 /* Note that we use DECL_CONTEXT, rather than
3855 CP_DECL_CONTEXT, so that the termination test is
3856 always just `ctx'. We're not interested in namepace
3858 for (ctx = current_class_type;
3860 ctx = (TYPE_P (ctx)) ? TYPE_CONTEXT (ctx) : DECL_CONTEXT (ctx))
3861 if (same_type_p (ctx, template_type))
3865 /* We're not in the scope of the class, so the
3866 TEMPLATE_TYPE is not the type we want after
3874 for (found = DECL_TEMPLATE_INSTANTIATIONS (template);
3875 found; found = TREE_CHAIN (found))
3876 if (comp_template_args (TREE_PURPOSE (found), arglist))
3880 found = TREE_VALUE (found);
3886 /* This type is a "partial instantiation" if any of the template
3887 arguments still inolve template parameters. Note that we set
3888 IS_PARTIAL_INSTANTIATION for partial specializations as
3890 is_partial_instantiation = uses_template_parms (arglist);
3892 if (!is_partial_instantiation
3893 && !PRIMARY_TEMPLATE_P (template)
3894 && TREE_CODE (CP_DECL_CONTEXT (template)) == NAMESPACE_DECL)
3896 found = xref_tag_from_type (TREE_TYPE (template),
3897 DECL_NAME (template),
3902 /* Create the type. */
3903 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
3905 if (!is_partial_instantiation)
3906 t = start_enum (TYPE_IDENTIFIER (template_type));
3908 /* We don't want to call start_enum for this type, since
3909 the values for the enumeration constants may involve
3910 template parameters. And, no one should be interested
3911 in the enumeration constants for such a type. */
3912 t = make_node (ENUMERAL_TYPE);
3916 t = make_aggr_type (TREE_CODE (template_type));
3917 CLASSTYPE_DECLARED_CLASS (t)
3918 = CLASSTYPE_DECLARED_CLASS (template_type);
3919 CLASSTYPE_GOT_SEMICOLON (t) = 1;
3920 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
3921 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
3923 /* A local class. Make sure the decl gets registered properly. */
3924 if (context == current_function_decl)
3925 pushtag (DECL_NAME (template), t, 0);
3928 /* If we called start_enum or pushtag above, this information
3929 will already be set up. */
3932 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
3934 type_decl = create_implicit_typedef (DECL_NAME (template), t);
3935 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
3936 TYPE_STUB_DECL (t) = type_decl;
3937 DECL_SOURCE_FILE (type_decl)
3938 = DECL_SOURCE_FILE (TYPE_STUB_DECL (template_type));
3939 DECL_SOURCE_LINE (type_decl)
3940 = DECL_SOURCE_LINE (TYPE_STUB_DECL (template_type));
3943 type_decl = TYPE_NAME (t);
3945 /* Set up the template information. We have to figure out which
3946 template is the immediate parent if this is a full
3948 if (parm_depth == 1 || is_partial_instantiation
3949 || !PRIMARY_TEMPLATE_P (template))
3950 /* This case is easy; there are no member templates involved. */
3954 /* This is a full instantiation of a member template. There
3955 should be some partial instantiation of which this is an
3958 for (found = DECL_TEMPLATE_INSTANTIATIONS (template);
3959 found; found = TREE_CHAIN (found))
3962 tree tmpl = CLASSTYPE_TI_TEMPLATE (TREE_VALUE (found));
3964 /* We only want partial instantiations, here, not
3965 specializations or full instantiations. */
3966 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_VALUE (found))
3967 || !uses_template_parms (TREE_VALUE (found)))
3970 /* Temporarily reduce by one the number of levels in the
3971 ARGLIST and in FOUND so as to avoid comparing the
3972 last set of arguments. */
3973 TREE_VEC_LENGTH (arglist)--;
3974 TREE_VEC_LENGTH (TREE_PURPOSE (found)) --;
3976 /* See if the arguments match. If they do, then TMPL is
3977 the partial instantiation we want. */
3978 success = comp_template_args (TREE_PURPOSE (found), arglist);
3980 /* Restore the argument vectors to their full size. */
3981 TREE_VEC_LENGTH (arglist)++;
3982 TREE_VEC_LENGTH (TREE_PURPOSE (found))++;
3992 my_friendly_abort (0);
3995 SET_TYPE_TEMPLATE_INFO (t,
3996 tree_cons (found, arglist, NULL_TREE));
3997 DECL_TEMPLATE_INSTANTIATIONS (template)
3998 = tree_cons (arglist, t,
3999 DECL_TEMPLATE_INSTANTIATIONS (template));
4001 if (TREE_CODE (t) == ENUMERAL_TYPE
4002 && !is_partial_instantiation)
4003 /* Now that the type has been registered on the instantiations
4004 list, we set up the enumerators. Because the enumeration
4005 constants may involve the enumeration type itself, we make
4006 sure to register the type first, and then create the
4007 constants. That way, doing tsubst_expr for the enumeration
4008 constants won't result in recursive calls here; we'll find
4009 the instantiation and exit above. */
4010 tsubst_enum (template_type, t, arglist);
4012 /* Reset the name of the type, now that CLASSTYPE_TEMPLATE_INFO
4014 if (TREE_CODE (t) != ENUMERAL_TYPE)
4015 DECL_NAME (type_decl) = classtype_mangled_name (t);
4016 DECL_ASSEMBLER_NAME (type_decl) = DECL_NAME (type_decl);
4017 if (!is_partial_instantiation)
4019 DECL_ASSEMBLER_NAME (type_decl)
4020 = get_identifier (build_overload_name (t, 1, 1));
4022 /* For backwards compatibility; code that uses
4023 -fexternal-templates expects looking up a template to
4024 instantiate it. I think DDD still relies on this.
4025 (jason 8/20/1998) */
4026 if (TREE_CODE (t) != ENUMERAL_TYPE
4027 && flag_external_templates
4028 && CLASSTYPE_INTERFACE_KNOWN (TREE_TYPE (template))
4029 && ! CLASSTYPE_INTERFACE_ONLY (TREE_TYPE (template)))
4030 add_pending_template (t);
4033 /* If the type makes use of template parameters, the
4034 code that generates debugging information will crash. */
4035 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
4047 /* Called from for_each_template_parm via walk_tree. */
4050 for_each_template_parm_r (tp, walk_subtrees, d)
4056 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
4057 tree_fn_t fn = pfd->fn;
4058 void *data = pfd->data;
4061 && for_each_template_parm (TYPE_CONTEXT (t), fn, data))
4062 return error_mark_node;
4064 switch (TREE_CODE (t))
4067 if (TYPE_PTRMEMFUNC_FLAG (t))
4073 if (!TYPE_TEMPLATE_INFO (t))
4075 else if (for_each_template_parm (TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
4077 return error_mark_node;
4081 /* Since we're not going to walk subtrees, we have to do this
4083 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data))
4084 return error_mark_node;
4087 /* Check the return type. */
4088 if (for_each_template_parm (TREE_TYPE (t), fn, data))
4089 return error_mark_node;
4091 /* Check the parameter types. Since default arguments are not
4092 instantiated until they are needed, the TYPE_ARG_TYPES may
4093 contain expressions that involve template parameters. But,
4094 no-one should be looking at them yet. And, once they're
4095 instantiated, they don't contain template parameters, so
4096 there's no point in looking at them then, either. */
4100 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
4101 if (for_each_template_parm (TREE_VALUE (parm), fn, data))
4102 return error_mark_node;
4104 /* Since we've already handled the TYPE_ARG_TYPES, we don't
4105 want walk_tree walking into them itself. */
4112 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
4113 && for_each_template_parm (DECL_TI_ARGS (t), fn, data))
4114 return error_mark_node;
4119 if (DECL_CONTEXT (t)
4120 && for_each_template_parm (DECL_CONTEXT (t), fn, data))
4121 return error_mark_node;
4124 case TEMPLATE_TEMPLATE_PARM:
4125 /* Record template parameters such as `T' inside `TT<T>'. */
4126 if (TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t)
4127 && for_each_template_parm (TYPE_TI_ARGS (t), fn, data))
4128 return error_mark_node;
4131 case TEMPLATE_TYPE_PARM:
4132 case TEMPLATE_PARM_INDEX:
4133 if (fn && (*fn)(t, data))
4134 return error_mark_node;
4136 return error_mark_node;
4140 /* A template template parameter is encountered */
4141 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
4142 && for_each_template_parm (TREE_TYPE (t), fn, data))
4143 return error_mark_node;
4145 /* Already substituted template template parameter */
4150 if (!fn || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn, data))
4151 return error_mark_node;
4155 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
4156 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
4157 (TREE_TYPE (t)), fn, data))
4158 return error_mark_node;
4163 /* If there's no type, then this thing must be some expression
4164 involving template parameters. */
4165 if (!fn && !TREE_TYPE (t))
4166 return error_mark_node;
4171 case REINTERPRET_CAST_EXPR:
4172 case CONST_CAST_EXPR:
4173 case STATIC_CAST_EXPR:
4174 case DYNAMIC_CAST_EXPR:
4179 case PSEUDO_DTOR_EXPR:
4181 return error_mark_node;
4188 /* We didn't find any template parameters we liked. */
4192 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM, or
4193 TEMPLATE_PARM_INDEX in T, call FN with the parameter and the DATA.
4194 If FN returns non-zero, the iteration is terminated, and
4195 for_each_template_parm returns 1. Otherwise, the iteration
4196 continues. If FN never returns a non-zero value, the value
4197 returned by for_each_template_parm is 0. If FN is NULL, it is
4198 considered to be the function which always returns 1. */
4201 for_each_template_parm (t, fn, data)
4206 struct pair_fn_data pfd;
4212 /* Walk the tree. */
4213 return walk_tree (&t, for_each_template_parm_r, &pfd) != NULL_TREE;
4217 uses_template_parms (t)
4220 return for_each_template_parm (t, 0, 0);
4223 static struct tinst_level *current_tinst_level;
4224 static struct tinst_level *free_tinst_level;
4225 static int tinst_depth;
4226 extern int max_tinst_depth;
4227 #ifdef GATHER_STATISTICS
4230 static int tinst_level_tick;
4231 static int last_template_error_tick;
4233 /* Print out all the template instantiations that we are currently
4234 working on. If ERR, we are being called from cp_thing, so do
4235 the right thing for an error message. */
4238 print_template_context (err)
4241 struct tinst_level *p = current_tinst_level;
4243 char *file = input_filename;
4247 if (current_function_decl != p->decl
4248 && current_function_decl != NULL_TREE)
4249 /* We can get here during the processing of some synthesized
4250 method. Then, p->decl will be the function that's causing
4255 if (current_function_decl == p->decl)
4256 /* Avoid redundancy with the the "In function" line. */;
4258 fprintf (stderr, "%s: In instantiation of `%s':\n",
4259 file, decl_as_string (p->decl, TS_DECL_TYPE | TS_FUNC_NORETURN));
4267 for (; p; p = p->next)
4269 fprintf (stderr, "%s:%d: instantiated from `%s'\n", file, line,
4270 decl_as_string (p->decl, TS_DECL_TYPE | TS_FUNC_NORETURN));
4274 fprintf (stderr, "%s:%d: instantiated from here\n", file, line);
4277 /* Called from cp_thing to print the template context for an error. */
4280 maybe_print_template_context ()
4282 if (last_template_error_tick == tinst_level_tick
4283 || current_tinst_level == 0)
4286 last_template_error_tick = tinst_level_tick;
4287 print_template_context (1);
4291 push_tinst_level (d)
4294 struct tinst_level *new;
4296 if (tinst_depth >= max_tinst_depth)
4298 /* If the instantiation in question still has unbound template parms,
4299 we don't really care if we can't instantiate it, so just return.
4300 This happens with base instantiation for implicit `typename'. */
4301 if (uses_template_parms (d))
4304 last_template_error_tick = tinst_level_tick;
4305 cp_error ("template instantiation depth exceeds maximum of %d (use -ftemplate-depth-NN to increase the maximum) instantiating `%D'",
4306 max_tinst_depth, d);
4308 print_template_context (0);
4313 if (free_tinst_level)
4315 new = free_tinst_level;
4316 free_tinst_level = new->next;
4319 new = (struct tinst_level *) xmalloc (sizeof (struct tinst_level));
4323 new->file = input_filename;
4324 new->next = current_tinst_level;
4325 current_tinst_level = new;
4328 #ifdef GATHER_STATISTICS
4329 if (tinst_depth > depth_reached)
4330 depth_reached = tinst_depth;
4340 struct tinst_level *old = current_tinst_level;
4342 /* Restore the filename and line number stashed away when we started
4343 this instantiation. */
4345 input_filename = old->file;
4346 extract_interface_info ();
4348 current_tinst_level = old->next;
4349 old->next = free_tinst_level;
4350 free_tinst_level = old;
4355 struct tinst_level *
4358 struct tinst_level *p = current_tinst_level;
4361 for (; p->next ; p = p->next )
4366 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
4367 vector of template arguments, as for tsubst.
4369 Returns an appropriate tsbust'd friend declaration. */
4372 tsubst_friend_function (decl, args)
4378 char *file = input_filename;
4380 lineno = DECL_SOURCE_LINE (decl);
4381 input_filename = DECL_SOURCE_FILE (decl);
4383 if (TREE_CODE (decl) == FUNCTION_DECL
4384 && DECL_TEMPLATE_INSTANTIATION (decl)
4385 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
4386 /* This was a friend declared with an explicit template
4387 argument list, e.g.:
4391 to indicate that f was a template instantiation, not a new
4392 function declaration. Now, we have to figure out what
4393 instantiation of what template. */
4400 = lookup_template_function (tsubst_expr (DECL_TI_TEMPLATE (decl),
4401 args, /*complain=*/1,
4403 tsubst (DECL_TI_ARGS (decl),
4404 args, /*complain=*/1,
4406 new_friend = tsubst (decl, args, /*complain=*/1, NULL_TREE);
4407 tmpl = determine_specialization (template_id, new_friend,
4409 /*need_member_template=*/0);
4410 new_friend = instantiate_template (tmpl, new_args);
4414 new_friend = tsubst (decl, args, /*complain=*/1, NULL_TREE);
4416 /* The NEW_FRIEND will look like an instantiation, to the
4417 compiler, but is not an instantiation from the point of view of
4418 the language. For example, we might have had:
4420 template <class T> struct S {
4421 template <class U> friend void f(T, U);
4424 Then, in S<int>, template <class U> void f(int, U) is not an
4425 instantiation of anything. */
4426 DECL_USE_TEMPLATE (new_friend) = 0;
4427 if (TREE_CODE (decl) == TEMPLATE_DECL)
4428 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
4430 /* The mangled name for the NEW_FRIEND is incorrect. The call to
4431 tsubst will have resulted in a call to
4432 set_mangled_name_for_template_decl. But, the function is not a
4433 template instantiation and should not be mangled like one.
4434 Therefore, we remangle the function name. We don't have to do
4435 this if the NEW_FRIEND is a template since
4436 set_mangled_name_for_template_decl doesn't do anything if the
4437 function declaration still uses template arguments. */
4438 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
4440 set_mangled_name_for_decl (new_friend);
4441 DECL_RTL (new_friend) = 0;
4442 make_decl_rtl (new_friend, NULL_PTR, 1);
4445 if (DECL_NAMESPACE_SCOPE_P (new_friend))
4448 tree new_friend_template_info;
4449 tree new_friend_result_template_info;
4451 int new_friend_is_defn;
4453 /* We must save some information from NEW_FRIEND before calling
4454 duplicate decls since that function will free NEW_FRIEND if
4456 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
4457 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
4459 /* This declaration is a `primary' template. */
4460 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
4463 = DECL_INITIAL (DECL_TEMPLATE_RESULT (new_friend)) != NULL_TREE;
4464 new_friend_result_template_info
4465 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
4469 new_friend_is_defn = DECL_INITIAL (new_friend) != NULL_TREE;
4470 new_friend_result_template_info = NULL_TREE;
4473 /* Inside pushdecl_namespace_level, we will push into the
4474 current namespace. However, the friend function should go
4475 into the namespace of the template. */
4476 ns = decl_namespace_context (new_friend);
4477 push_nested_namespace (ns);
4478 old_decl = pushdecl_namespace_level (new_friend);
4479 pop_nested_namespace (ns);
4481 if (old_decl != new_friend)
4483 /* This new friend declaration matched an existing
4484 declaration. For example, given:
4486 template <class T> void f(T);
4487 template <class U> class C {
4488 template <class T> friend void f(T) {}
4491 the friend declaration actually provides the definition
4492 of `f', once C has been instantiated for some type. So,
4493 old_decl will be the out-of-class template declaration,
4494 while new_friend is the in-class definition.
4496 But, if `f' was called before this point, the
4497 instantiation of `f' will have DECL_TI_ARGS corresponding
4498 to `T' but not to `U', references to which might appear
4499 in the definition of `f'. Previously, the most general
4500 template for an instantiation of `f' was the out-of-class
4501 version; now it is the in-class version. Therefore, we
4502 run through all specialization of `f', adding to their
4503 DECL_TI_ARGS appropriately. In particular, they need a
4504 new set of outer arguments, corresponding to the
4505 arguments for this class instantiation.
4507 The same situation can arise with something like this:
4510 template <class T> class C {
4514 when `C<int>' is instantiated. Now, `f(int)' is defined
4517 if (!new_friend_is_defn)
4518 /* On the other hand, if the in-class declaration does
4519 *not* provide a definition, then we don't want to alter
4520 existing definitions. We can just leave everything
4525 /* Overwrite whatever template info was there before, if
4526 any, with the new template information pertaining to
4528 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
4530 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
4531 /* duplicate_decls will take care of this case. */
4536 tree new_friend_args;
4538 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
4539 = new_friend_result_template_info;
4541 new_friend_args = TI_ARGS (new_friend_template_info);
4542 for (t = DECL_TEMPLATE_SPECIALIZATIONS (old_decl);
4546 tree spec = TREE_VALUE (t);
4549 = add_outermost_template_args (new_friend_args,
4550 DECL_TI_ARGS (spec));
4553 /* Now, since specializations are always supposed to
4554 hang off of the most general template, we must move
4556 t = most_general_template (old_decl);
4559 DECL_TEMPLATE_SPECIALIZATIONS (t)
4560 = chainon (DECL_TEMPLATE_SPECIALIZATIONS (t),
4561 DECL_TEMPLATE_SPECIALIZATIONS (old_decl));
4562 DECL_TEMPLATE_SPECIALIZATIONS (old_decl) = NULL_TREE;
4567 /* The information from NEW_FRIEND has been merged into OLD_DECL
4568 by duplicate_decls. */
4569 new_friend = old_decl;
4572 else if (COMPLETE_TYPE_P (DECL_CONTEXT (new_friend)))
4574 /* Check to see that the declaration is really present, and,
4575 possibly obtain an improved declaration. */
4576 tree fn = check_classfn (DECL_CONTEXT (new_friend),
4585 input_filename = file;
4589 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
4590 template arguments, as for tsubst.
4592 Returns an appropriate tsbust'd friend type. */
4595 tsubst_friend_class (friend_tmpl, args)
4602 /* First, we look for a class template. */
4603 tmpl = lookup_name (DECL_NAME (friend_tmpl), /*prefer_type=*/0);
4605 /* But, if we don't find one, it might be because we're in a
4606 situation like this:
4614 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
4615 for `S<int>', not the TEMPLATE_DECL. */
4616 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
4618 tmpl = lookup_name (DECL_NAME (friend_tmpl), /*prefer_type=*/1);
4619 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
4622 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
4624 /* The friend template has already been declared. Just
4625 check to see that the declarations match, and install any new
4626 default parameters. We must tsubst the default parameters,
4627 of course. We only need the innermost template parameters
4628 because that is all that redeclare_class_template will look
4631 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
4632 args, /*complain=*/1);
4633 redeclare_class_template (TREE_TYPE (tmpl), parms);
4634 friend_type = TREE_TYPE (tmpl);
4638 /* The friend template has not already been declared. In this
4639 case, the instantiation of the template class will cause the
4640 injection of this template into the global scope. */
4641 tmpl = tsubst (friend_tmpl, args, /*complain=*/1, NULL_TREE);
4643 /* The new TMPL is not an instantiation of anything, so we
4644 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
4645 the new type because that is supposed to be the corresponding
4646 template decl, i.e., TMPL. */
4647 DECL_USE_TEMPLATE (tmpl) = 0;
4648 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
4649 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
4651 /* Inject this template into the global scope. */
4652 friend_type = TREE_TYPE (pushdecl_top_level (tmpl));
4659 instantiate_class_template (type)
4662 tree template, args, pattern, t;
4665 if (type == error_mark_node)
4666 return error_mark_node;
4668 if (TYPE_BEING_DEFINED (type) || COMPLETE_TYPE_P (type))
4671 /* Figure out which template is being instantiated. */
4672 template = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
4673 my_friendly_assert (TREE_CODE (template) == TEMPLATE_DECL, 279);
4675 /* Figure out which arguments are being used to do the
4677 args = CLASSTYPE_TI_ARGS (type);
4678 PARTIAL_INSTANTIATION_P (type) = uses_template_parms (args);
4680 if (pedantic && PARTIAL_INSTANTIATION_P (type))
4681 /* If this is a partial instantiation, then we can't instantiate
4682 the type; there's no telling whether or not one of the
4683 template parameters might eventually be instantiated to some
4684 value that results in a specialization being used. For
4696 Now, the `S<U>' in `f<int>' is the specialization, not an
4697 instantiation of the original template. */
4700 /* Determine what specialization of the original template to
4702 if (PARTIAL_INSTANTIATION_P (type))
4703 /* There's no telling which specialization is appropriate at this
4704 point. Since all peeking at the innards of this partial
4705 instantiation are extensions (like the "implicit typename"
4706 extension, which allows users to omit the keyword `typename' on
4707 names that are declared as types in template base classes), we
4708 are free to do what we please.
4710 Trying to figure out which partial instantiation to use can
4711 cause a crash. (Some of the template arguments don't even have
4712 types.) So, we just use the most general version. */
4716 t = most_specialized_class (template, args);
4718 if (t == error_mark_node)
4720 const char *str = "candidates are:";
4721 cp_error ("ambiguous class template instantiation for `%#T'", type);
4722 for (t = DECL_TEMPLATE_SPECIALIZATIONS (template); t;
4725 if (get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t),
4728 cp_error_at ("%s %+#T", str, TREE_TYPE (t));
4732 TYPE_BEING_DEFINED (type) = 1;
4733 return error_mark_node;
4738 pattern = TREE_TYPE (t);
4740 pattern = TREE_TYPE (template);
4742 /* If the template we're instantiating is incomplete, then clearly
4743 there's nothing we can do. */
4744 if (!COMPLETE_TYPE_P (pattern))
4747 /* If this is a partial instantiation, don't tsubst anything. We will
4748 only use this type for implicit typename, so the actual contents don't
4749 matter. All that matters is whether a particular name is a type. */
4750 if (PARTIAL_INSTANTIATION_P (type))
4752 /* The fields set here must be kept in sync with those cleared
4753 in begin_class_definition. */
4754 TYPE_BINFO_BASETYPES (type) = TYPE_BINFO_BASETYPES (pattern);
4755 TYPE_FIELDS (type) = TYPE_FIELDS (pattern);
4756 TYPE_METHODS (type) = TYPE_METHODS (pattern);
4757 CLASSTYPE_TAGS (type) = CLASSTYPE_TAGS (pattern);
4758 /* Pretend that the type is complete, so that we will look
4759 inside it during name lookup and such. */
4760 TYPE_SIZE (type) = integer_zero_node;
4764 /* If we've recursively instantiated too many templates, stop. */
4765 if (! push_tinst_level (type))
4768 /* Now we're really doing the instantiation. Mark the type as in
4769 the process of being defined. */
4770 TYPE_BEING_DEFINED (type) = 1;
4772 maybe_push_to_top_level (uses_template_parms (type));
4776 /* This TYPE is actually a instantiation of of a partial
4777 specialization. We replace the innermost set of ARGS with
4778 the arguments appropriate for substitution. For example,
4781 template <class T> struct S {};
4782 template <class T> struct S<T*> {};
4784 and supposing that we are instantiating S<int*>, ARGS will
4785 present be {int*} but we need {int}. */
4787 = get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t),
4790 /* If there were multiple levels in ARGS, replacing the
4791 innermost level would alter CLASSTYPE_TI_ARGS, which we don't
4792 want, so we make a copy first. */
4793 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
4795 args = copy_node (args);
4796 SET_TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args), inner_args);
4802 if (flag_external_templates)
4804 if (flag_alt_external_templates)
4806 CLASSTYPE_INTERFACE_ONLY (type) = interface_only;
4807 SET_CLASSTYPE_INTERFACE_UNKNOWN_X (type, interface_unknown);
4808 CLASSTYPE_VTABLE_NEEDS_WRITING (type)
4809 = (! CLASSTYPE_INTERFACE_ONLY (type)
4810 && CLASSTYPE_INTERFACE_KNOWN (type));
4814 CLASSTYPE_INTERFACE_ONLY (type) = CLASSTYPE_INTERFACE_ONLY (pattern);
4815 SET_CLASSTYPE_INTERFACE_UNKNOWN_X
4816 (type, CLASSTYPE_INTERFACE_UNKNOWN (pattern));
4817 CLASSTYPE_VTABLE_NEEDS_WRITING (type)
4818 = (! CLASSTYPE_INTERFACE_ONLY (type)
4819 && CLASSTYPE_INTERFACE_KNOWN (type));
4824 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
4825 CLASSTYPE_VTABLE_NEEDS_WRITING (type) = 1;
4828 TYPE_HAS_CONSTRUCTOR (type) = TYPE_HAS_CONSTRUCTOR (pattern);
4829 TYPE_HAS_DESTRUCTOR (type) = TYPE_HAS_DESTRUCTOR (pattern);
4830 TYPE_OVERLOADS_CALL_EXPR (type) = TYPE_OVERLOADS_CALL_EXPR (pattern);
4831 TYPE_OVERLOADS_ARRAY_REF (type) = TYPE_OVERLOADS_ARRAY_REF (pattern);
4832 TYPE_OVERLOADS_ARROW (type) = TYPE_OVERLOADS_ARROW (pattern);
4833 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
4834 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
4835 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
4836 TYPE_VEC_DELETE_TAKES_SIZE (type) = TYPE_VEC_DELETE_TAKES_SIZE (pattern);
4837 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
4838 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
4839 TYPE_HAS_ABSTRACT_ASSIGN_REF (type) = TYPE_HAS_ABSTRACT_ASSIGN_REF (pattern);
4840 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
4841 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
4842 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
4843 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
4844 TYPE_BASE_CONVS_MAY_REQUIRE_CODE_P (type)
4845 = TYPE_BASE_CONVS_MAY_REQUIRE_CODE_P (pattern);
4846 TYPE_USES_MULTIPLE_INHERITANCE (type)
4847 = TYPE_USES_MULTIPLE_INHERITANCE (pattern);
4848 TYPE_USES_VIRTUAL_BASECLASSES (type)
4849 = TYPE_USES_VIRTUAL_BASECLASSES (pattern);
4850 TYPE_PACKED (type) = TYPE_PACKED (pattern);
4851 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
4852 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
4853 if (ANON_AGGR_TYPE_P (pattern))
4854 SET_ANON_AGGR_TYPE_P (type);
4856 if (TYPE_BINFO_BASETYPES (pattern))
4858 tree base_list = NULL_TREE;
4859 tree pbases = TYPE_BINFO_BASETYPES (pattern);
4862 /* Substitute into each of the bases to determine the actual
4864 for (i = 0; i < TREE_VEC_LENGTH (pbases); ++i)
4870 pbase = TREE_VEC_ELT (pbases, i);
4872 /* Substitue to figure out the base class. */
4873 base = tsubst (BINFO_TYPE (pbase), args,
4874 /*complain=*/1, NULL_TREE);
4875 if (base == error_mark_node)
4878 /* Calculate the correct access node. */
4879 if (TREE_VIA_VIRTUAL (pbase))
4881 if (TREE_VIA_PUBLIC (pbase))
4882 access = access_public_virtual_node;
4883 else if (TREE_VIA_PROTECTED (pbase))
4884 access = access_protected_virtual_node;
4886 access = access_private_virtual_node;
4890 if (TREE_VIA_PUBLIC (pbase))
4891 access = access_public_node;
4892 else if (TREE_VIA_PROTECTED (pbase))
4893 access = access_protected_node;
4895 access = access_private_node;
4898 base_list = tree_cons (access, base, base_list);
4901 /* The list is now in reverse order; correct that. */
4902 base_list = nreverse (base_list);
4904 /* Now call xref_basetypes to set up all the base-class
4906 xref_basetypes (TREE_CODE (pattern) == RECORD_TYPE
4907 ? (CLASSTYPE_DECLARED_CLASS (pattern)
4908 ? class_type_node : record_type_node)
4910 DECL_NAME (TYPE_NAME (pattern)),
4915 /* Now that our base classes are set up, enter the scope of the
4916 class, so that name lookups into base classes, etc. will work
4917 corectly. This is precisely analagous to what we do in
4918 begin_class_definition when defining an ordinary non-template
4920 pushclass (type, 1);
4922 for (t = CLASSTYPE_TAGS (pattern); t; t = TREE_CHAIN (t))
4924 tree tag = TREE_VALUE (t);
4925 tree name = TYPE_IDENTIFIER (tag);
4928 newtag = tsubst (tag, args, /*complain=*/1, NULL_TREE);
4929 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
4931 if (TYPE_LANG_SPECIFIC (tag) && CLASSTYPE_IS_TEMPLATE (tag))
4932 /* Unfortunately, lookup_template_class sets
4933 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
4934 instantiation (i.e., for the type of a member template
4935 class nested within a template class.) This behavior is
4936 required for maybe_process_partial_specialization to work
4937 correctly, but is not accurate in this case; the TAG is not
4938 an instantiation of anything. (The corresponding
4939 TEMPLATE_DECL is an instantiation, but the TYPE is not.) */
4940 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
4942 /* Now, we call pushtag to put this NEWTAG into the scope of
4943 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
4944 pushtag calling push_template_decl. We don't have to do
4945 this for enums because it will already have been done in
4948 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
4949 pushtag (name, newtag, /*globalize=*/0);
4953 /* Don't replace enum constants here. */
4954 for (t = TYPE_FIELDS (pattern); t; t = TREE_CHAIN (t))
4955 if (TREE_CODE (t) != CONST_DECL)
4959 /* The the file and line for this declaration, to assist in
4960 error message reporting. Since we called push_tinst_level
4961 above, we don't need to restore these. */
4962 lineno = DECL_SOURCE_LINE (t);
4963 input_filename = DECL_SOURCE_FILE (t);
4965 r = tsubst (t, args, /*complain=*/1, NULL_TREE);
4966 if (TREE_CODE (r) == VAR_DECL)
4970 if (DECL_DEFINED_IN_CLASS_P (r))
4971 init = tsubst_expr (DECL_INITIAL (t), args,
4972 /*complain=*/1, NULL_TREE);
4976 finish_static_data_member_decl (r, init,
4977 /*asmspec_tree=*/NULL_TREE,
4980 if (DECL_DEFINED_IN_CLASS_P (r))
4981 check_static_variable_definition (r, TREE_TYPE (r));
4984 /* R will have a TREE_CHAIN if and only if it has already been
4985 processed by finish_member_declaration. This can happen
4986 if, for example, it is a TYPE_DECL for a class-scoped
4987 ENUMERAL_TYPE; such a thing will already have been added to
4988 the field list by tsubst_enum above. */
4989 if (!TREE_CHAIN (r))
4991 set_current_access_from_decl (r);
4992 finish_member_declaration (r);
4996 /* Set up the list (TYPE_METHODS) and vector (CLASSTYPE_METHOD_VEC)
4997 for this instantiation. */
4998 for (t = TYPE_METHODS (pattern); t; t = TREE_CHAIN (t))
5000 tree r = tsubst (t, args, /*complain=*/1, NULL_TREE);
5001 set_current_access_from_decl (r);
5002 finish_member_declaration (r);
5005 /* Construct the DECL_FRIENDLIST for the new class type. */
5006 typedecl = TYPE_MAIN_DECL (type);
5007 for (t = DECL_FRIENDLIST (TYPE_MAIN_DECL (pattern));
5013 for (friends = TREE_VALUE (t);
5014 friends != NULL_TREE;
5015 friends = TREE_CHAIN (friends))
5016 if (TREE_PURPOSE (friends) == error_mark_node)
5018 tsubst_friend_function (TREE_VALUE (friends),
5021 my_friendly_abort (20000216);
5024 for (t = CLASSTYPE_FRIEND_CLASSES (pattern);
5028 tree friend_type = TREE_VALUE (t);
5029 tree new_friend_type;
5031 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5032 new_friend_type = tsubst_friend_class (friend_type, args);
5033 else if (uses_template_parms (friend_type))
5034 new_friend_type = tsubst (friend_type, args, /*complain=*/1,
5038 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
5040 /* The call to xref_tag_from_type does injection for friend
5042 push_nested_namespace (ns);
5044 xref_tag_from_type (friend_type, NULL_TREE, 1);
5045 pop_nested_namespace (ns);
5048 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5049 /* Trick make_friend_class into realizing that the friend
5050 we're adding is a template, not an ordinary class. It's
5051 important that we use make_friend_class since it will
5052 perform some error-checking and output cross-reference
5054 ++processing_template_decl;
5056 make_friend_class (type, new_friend_type);
5058 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
5059 --processing_template_decl;
5062 for (t = TYPE_FIELDS (type); t; t = TREE_CHAIN (t))
5063 if (TREE_CODE (t) == FIELD_DECL)
5065 TREE_TYPE (t) = complete_type (TREE_TYPE (t));
5066 require_complete_type (t);
5069 /* Set the file and line number information to whatever is given for
5070 the class itself. This puts error messages involving generated
5071 implicit functions at a predictable point, and the same point
5072 that would be used for non-template classes. */
5073 lineno = DECL_SOURCE_LINE (typedecl);
5074 input_filename = DECL_SOURCE_FILE (typedecl);
5076 unreverse_member_declarations (type);
5077 finish_struct_1 (type);
5078 CLASSTYPE_GOT_SEMICOLON (type) = 1;
5080 /* Clear this now so repo_template_used is happy. */
5081 TYPE_BEING_DEFINED (type) = 0;
5082 repo_template_used (type);
5084 /* Now that the class is complete, instantiate default arguments for
5085 any member functions. We don't do this earlier because the
5086 default arguments may reference members of the class. */
5087 if (!PRIMARY_TEMPLATE_P (template))
5088 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
5089 if (TREE_CODE (t) == FUNCTION_DECL
5090 /* Implicitly generated member functions will not have tmplate
5091 information; they are not instantiations, but instead are
5092 created "fresh" for each instantiation. */
5093 && DECL_TEMPLATE_INFO (t))
5094 tsubst_default_arguments (t);
5097 pop_from_top_level ();
5107 if (t1 == NULL_TREE)
5108 return t2 == NULL_TREE;
5109 if (t2 == NULL_TREE)
5111 /* Don't care if one declares its arg const and the other doesn't -- the
5112 main variant of the arg type is all that matters. */
5113 if (TYPE_MAIN_VARIANT (TREE_VALUE (t1))
5114 != TYPE_MAIN_VARIANT (TREE_VALUE (t2)))
5116 return list_eq (TREE_CHAIN (t1), TREE_CHAIN (t2));
5119 /* If arg is a non-type template parameter that does not depend on template
5120 arguments, fold it like we weren't in the body of a template. */
5123 maybe_fold_nontype_arg (arg)
5126 /* If we're not in a template, ARG is already as simple as it's going to
5127 get, and trying to reprocess the trees will break. */
5128 if (! processing_template_decl)
5131 if (!TYPE_P (arg) && !uses_template_parms (arg))
5133 /* Sometimes, one of the args was an expression involving a
5134 template constant parameter, like N - 1. Now that we've
5135 tsubst'd, we might have something like 2 - 1. This will
5136 confuse lookup_template_class, so we do constant folding
5137 here. We have to unset processing_template_decl, to
5138 fool build_expr_from_tree() into building an actual
5141 int saved_processing_template_decl = processing_template_decl;
5142 processing_template_decl = 0;
5143 arg = fold (build_expr_from_tree (arg));
5144 processing_template_decl = saved_processing_template_decl;
5149 /* Return the TREE_VEC with the arguments for the innermost template header,
5150 where ARGS is either that or the VEC of VECs for all the
5154 innermost_args (args)
5157 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
5160 /* Substitute ARGS into the vector of template arguments T. */
5163 tsubst_template_arg_vector (t, args, complain)
5168 int len = TREE_VEC_LENGTH (t), need_new = 0, i;
5169 tree *elts = (tree *) alloca (len * sizeof (tree));
5171 bzero ((char *) elts, len * sizeof (tree));
5173 for (i = 0; i < len; i++)
5175 if (TREE_VEC_ELT (t, i) != NULL_TREE
5176 && TREE_CODE (TREE_VEC_ELT (t, i)) == TREE_VEC)
5177 elts[i] = tsubst_template_arg_vector (TREE_VEC_ELT (t, i),
5180 elts[i] = maybe_fold_nontype_arg
5181 (tsubst_expr (TREE_VEC_ELT (t, i), args, complain,
5184 if (elts[i] != TREE_VEC_ELT (t, i))
5191 t = make_tree_vec (len);
5192 for (i = 0; i < len; i++)
5193 TREE_VEC_ELT (t, i) = elts[i];
5198 /* Return the result of substituting ARGS into the template parameters
5199 given by PARMS. If there are m levels of ARGS and m + n levels of
5200 PARMS, then the result will contain n levels of PARMS. For
5201 example, if PARMS is `template <class T> template <class U>
5202 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
5203 result will be `template <int*, double, class V>'. */
5206 tsubst_template_parms (parms, args, complain)
5214 for (new_parms = &r;
5215 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
5216 new_parms = &(TREE_CHAIN (*new_parms)),
5217 parms = TREE_CHAIN (parms))
5220 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
5223 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
5225 tree default_value =
5226 TREE_PURPOSE (TREE_VEC_ELT (TREE_VALUE (parms), i));
5228 TREE_VALUE (TREE_VEC_ELT (TREE_VALUE (parms), i));
5230 TREE_VEC_ELT (new_vec, i)
5231 = build_tree_list (tsubst (default_value, args, complain,
5233 tsubst (parm_decl, args, complain,
5238 tree_cons (build_int_2 (0, (TMPL_PARMS_DEPTH (parms)
5239 - TMPL_ARGS_DEPTH (args))),
5240 new_vec, NULL_TREE);
5246 /* Substitute the ARGS into the indicated aggregate (or enumeration)
5247 type T. If T is not an aggregate or enumeration type, it is
5248 handled as if by tsubst. IN_DECL is as for tsubst. If
5249 ENTERING_SCOPE is non-zero, T is the context for a template which
5250 we are presently tsubst'ing. Return the subsituted value. */
5253 tsubst_aggr_type (t, args, complain, in_decl, entering_scope)
5263 switch (TREE_CODE (t))
5266 if (TYPE_PTRMEMFUNC_P (t))
5268 tree r = build_ptrmemfunc_type
5269 (tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl));
5270 return cp_build_qualified_type_real (r, TYPE_QUALS (t),
5274 /* else fall through */
5277 if (TYPE_TEMPLATE_INFO (t))
5283 /* First, determine the context for the type we are looking
5285 if (TYPE_CONTEXT (t) != NULL_TREE)
5286 context = tsubst_aggr_type (TYPE_CONTEXT (t), args,
5288 in_decl, /*entering_scope=*/1);
5290 context = NULL_TREE;
5292 /* Then, figure out what arguments are appropriate for the
5293 type we are trying to find. For example, given:
5295 template <class T> struct S;
5296 template <class T, class U> void f(T, U) { S<U> su; }
5298 and supposing that we are instantiating f<int, double>,
5299 then our ARGS will be {int, double}, but, when looking up
5300 S we only want {double}. */
5301 argvec = tsubst_template_arg_vector (TYPE_TI_ARGS (t), args,
5304 r = lookup_template_class (t, argvec, in_decl, context,
5307 return cp_build_qualified_type_real (r, TYPE_QUALS (t),
5311 /* This is not a template type, so there's nothing to do. */
5315 return tsubst (t, args, complain, in_decl);
5319 /* Substitute into the default argument ARG (a default argument for
5320 FN), which has the indicated TYPE. */
5323 tsubst_default_argument (fn, type, arg)
5328 /* This default argument came from a template. Instantiate the
5329 default argument here, not in tsubst. In the case of
5338 we must be careful to do name lookup in the scope of S<T>,
5339 rather than in the current class. */
5340 if (DECL_CLASS_SCOPE_P (fn))
5341 pushclass (DECL_CONTEXT (fn), 2);
5343 arg = tsubst_expr (arg, DECL_TI_ARGS (fn), /*complain=*/1, NULL_TREE);
5345 if (DECL_CLASS_SCOPE_P (fn))
5348 /* Make sure the default argument is reasonable. */
5349 arg = check_default_argument (type, arg);
5354 /* Substitute into all the default arguments for FN. */
5357 tsubst_default_arguments (fn)
5363 tmpl_args = DECL_TI_ARGS (fn);
5365 /* If this function is not yet instantiated, we certainly don't need
5366 its default arguments. */
5367 if (uses_template_parms (tmpl_args))
5370 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
5372 arg = TREE_CHAIN (arg))
5373 if (TREE_PURPOSE (arg))
5374 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
5376 TREE_PURPOSE (arg));
5379 /* Substitute the ARGS into the T, which is a _DECL. TYPE is the
5380 (already computed) substitution of ARGS into TREE_TYPE (T), if
5381 appropriate. Return the result of the substitution. IN_DECL is as
5385 tsubst_decl (t, args, type, in_decl)
5392 char* saved_filename;
5395 /* Set the filename and linenumber to improve error-reporting. */
5396 saved_lineno = lineno;
5397 saved_filename = input_filename;
5398 lineno = DECL_SOURCE_LINE (t);
5399 input_filename = DECL_SOURCE_FILE (t);
5401 switch (TREE_CODE (t))
5405 /* We can get here when processing a member template function
5406 of a template class. */
5407 tree decl = DECL_TEMPLATE_RESULT (t);
5409 int is_template_template_parm = DECL_TEMPLATE_TEMPLATE_PARM_P (t);
5411 if (!is_template_template_parm)
5413 /* We might already have an instance of this template.
5414 The ARGS are for the surrounding class type, so the
5415 full args contain the tsubst'd args for the context,
5416 plus the innermost args from the template decl. */
5417 tree tmpl_args = DECL_CLASS_TEMPLATE_P (t)
5418 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
5419 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
5422 full_args = tsubst_template_arg_vector (tmpl_args, args,
5425 /* tsubst_template_arg_vector doesn't copy the vector if
5426 nothing changed. But, *something* should have
5428 my_friendly_assert (full_args != tmpl_args, 0);
5430 spec = retrieve_specialization (t, full_args);
5431 if (spec != NULL_TREE)
5438 /* Make a new template decl. It will be similar to the
5439 original, but will record the current template arguments.
5440 We also create a new function declaration, which is just
5441 like the old one, but points to this new template, rather
5442 than the old one. */
5445 my_friendly_assert (DECL_LANG_SPECIFIC (r) != 0, 0);
5446 TREE_CHAIN (r) = NULL_TREE;
5448 if (is_template_template_parm)
5450 tree new_decl = tsubst (decl, args, /*complain=*/1, in_decl);
5451 DECL_TEMPLATE_RESULT (r) = new_decl;
5452 TREE_TYPE (r) = TREE_TYPE (new_decl);
5457 = tsubst_aggr_type (DECL_CONTEXT (t), args,
5458 /*complain=*/1, in_decl,
5459 /*entering_scope=*/1);
5460 DECL_VIRTUAL_CONTEXT (r)
5461 = tsubst_aggr_type (DECL_VIRTUAL_CONTEXT (t), args,
5462 /*complain=*/1, in_decl,
5463 /*entering_scope=*/1);
5464 DECL_TEMPLATE_INFO (r) = build_tree_list (t, args);
5466 if (TREE_CODE (decl) == TYPE_DECL)
5468 tree new_type = tsubst (TREE_TYPE (t), args,
5469 /*complain=*/1, in_decl);
5470 TREE_TYPE (r) = new_type;
5471 CLASSTYPE_TI_TEMPLATE (new_type) = r;
5472 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
5473 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
5477 tree new_decl = tsubst (decl, args, /*complain=*/1, in_decl);
5479 DECL_TEMPLATE_RESULT (r) = new_decl;
5480 DECL_TI_TEMPLATE (new_decl) = r;
5481 TREE_TYPE (r) = TREE_TYPE (new_decl);
5482 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
5485 SET_DECL_IMPLICIT_INSTANTIATION (r);
5486 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
5487 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
5489 /* The template parameters for this new template are all the
5490 template parameters for the old template, except the
5491 outermost level of parameters. */
5492 DECL_TEMPLATE_PARMS (r)
5493 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
5496 if (PRIMARY_TEMPLATE_P (t))
5497 DECL_PRIMARY_TEMPLATE (r) = r;
5499 /* We don't partially instantiate partial specializations. */
5500 if (TREE_CODE (decl) == TYPE_DECL)
5503 for (spec = DECL_TEMPLATE_SPECIALIZATIONS (t);
5505 spec = TREE_CHAIN (spec))
5507 /* It helps to consider example here. Consider:
5518 Now, for example, we are instantiating S<int>::f(U u).
5519 We want to make a template:
5524 It will have a specialization, for the case U = int*, of
5528 void S<int>::f<int*>(int*);
5530 This specialization will be an instantiation of
5531 the specialization given in the declaration of S, with
5532 argument list int*. */
5534 tree fn = TREE_VALUE (spec);
5538 if (!DECL_TEMPLATE_SPECIALIZATION (fn))
5539 /* Instantiations are on the same list, but they're of
5540 no concern to us. */
5543 if (TREE_CODE (fn) != TEMPLATE_DECL)
5544 /* A full specialization. There's no need to record
5548 spec_args = tsubst (DECL_TI_ARGS (fn), args,
5549 /*complain=*/1, in_decl);
5551 = tsubst (DECL_TEMPLATE_RESULT (most_general_template (fn)),
5552 spec_args, /*complain=*/1, in_decl);
5553 DECL_TI_TEMPLATE (new_fn) = fn;
5554 register_specialization (new_fn, r,
5555 innermost_args (spec_args));
5558 /* Record this partial instantiation. */
5559 register_specialization (r, t,
5560 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)));
5568 tree argvec = NULL_TREE;
5575 /* Nobody should be tsubst'ing into non-template functions. */
5576 my_friendly_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE, 0);
5578 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
5582 /* Calculate the most general template of which R is a
5583 specialization, and the complete set of arguments used to
5585 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
5587 = tsubst_template_arg_vector (DECL_TI_ARGS
5588 (DECL_TEMPLATE_RESULT (gen_tmpl)),
5589 args, /*complain=*/1);
5591 /* Check to see if we already have this specialization. */
5592 spec = retrieve_specialization (gen_tmpl, argvec);
5600 /* Here, we deal with the peculiar case:
5602 template <class T> struct S {
5603 template <class U> friend void f();
5605 template <class U> void f() {}
5607 template void f<double>();
5609 Here, the ARGS for the instantiation of will be {int,
5610 double}. But, we only need as many ARGS as there are
5611 levels of template parameters in CODE_PATTERN. We are
5612 careful not to get fooled into reducing the ARGS in
5615 template <class T> struct S { template <class U> void f(U); }
5616 template <class T> template <> void S<T>::f(int) {}
5618 which we can spot because the pattern will be a
5619 specialization in this case. */
5620 args_depth = TMPL_ARGS_DEPTH (args);
5622 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
5623 if (args_depth > parms_depth
5624 && !DECL_TEMPLATE_SPECIALIZATION (t))
5626 my_friendly_assert (DECL_FRIEND_P (t), 0);
5628 if (parms_depth > 1)
5632 args = make_tree_vec (parms_depth);
5633 for (i = 0; i < parms_depth; ++i)
5634 TREE_VEC_ELT (args, i) =
5635 TREE_VEC_ELT (args, i + (args_depth - parms_depth));
5638 args = TREE_VEC_ELT (args, args_depth - parms_depth);
5643 /* This special case arises when we have something like this:
5645 template <class T> struct S {
5646 friend void f<int>(int, double);
5649 Here, the DECL_TI_TEMPLATE for the friend declaration
5650 will be a LOOKUP_EXPR or an IDENTIFIER_NODE. We are
5651 being called from tsubst_friend_function, and we want
5652 only to create a new decl (R) with appropriate types so
5653 that we can call determine_specialization. */
5654 my_friendly_assert ((TREE_CODE (DECL_TI_TEMPLATE (t))
5656 || (TREE_CODE (DECL_TI_TEMPLATE (t))
5657 == IDENTIFIER_NODE), 0);
5658 gen_tmpl = NULL_TREE;
5661 if (DECL_CLASS_SCOPE_P (t))
5663 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
5667 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
5669 /*entering_scope=*/1);
5674 ctx = DECL_CONTEXT (t);
5676 type = tsubst (type, args, /*complain=*/1, in_decl);
5677 if (type == error_mark_node)
5678 return error_mark_node;
5680 /* We do NOT check for matching decls pushed separately at this
5681 point, as they may not represent instantiations of this
5682 template, and in any case are considered separate under the
5683 discrete model. Instead, see add_maybe_template. */
5687 DECL_USE_TEMPLATE (r) = 0;
5688 TREE_TYPE (r) = type;
5690 DECL_CONTEXT (r) = ctx;
5691 DECL_VIRTUAL_CONTEXT (r)
5692 = tsubst_aggr_type (DECL_VIRTUAL_CONTEXT (t), args,
5694 /*entering_scope=*/1);
5696 if (member && IDENTIFIER_TYPENAME_P (DECL_NAME (r)))
5697 /* Type-conversion operator. Reconstruct the name, in
5698 case it's the name of one of the template's parameters. */
5699 DECL_NAME (r) = build_typename_overload (TREE_TYPE (type));
5701 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
5703 DECL_MAIN_VARIANT (r) = r;
5704 DECL_TEMPLATE_RESULT (r) = NULL_TREE;
5706 TREE_STATIC (r) = 0;
5707 TREE_PUBLIC (r) = TREE_PUBLIC (t);
5708 DECL_EXTERNAL (r) = 1;
5709 DECL_INTERFACE_KNOWN (r) = 0;
5710 DECL_DEFER_OUTPUT (r) = 0;
5711 TREE_CHAIN (r) = NULL_TREE;
5712 DECL_PENDING_INLINE_INFO (r) = 0;
5713 DECL_PENDING_INLINE_P (r) = 0;
5716 /* Set up the DECL_TEMPLATE_INFO for R and compute its mangled
5717 name. There's no need to do this in the special friend
5718 case mentioned above where GEN_TMPL is NULL. */
5721 DECL_TEMPLATE_INFO (r)
5722 = tree_cons (gen_tmpl, argvec, NULL_TREE);
5723 SET_DECL_IMPLICIT_INSTANTIATION (r);
5724 register_specialization (r, gen_tmpl, argvec);
5726 /* Set the mangled name for R. */
5727 if (DECL_DESTRUCTOR_P (t))
5728 DECL_ASSEMBLER_NAME (r) = build_destructor_name (ctx);
5731 /* Instantiations of template functions must be mangled
5732 specially, in order to conform to 14.5.5.1
5733 [temp.over.link]. */
5734 tree tmpl = DECL_TI_TEMPLATE (t);
5736 /* TMPL will be NULL if this is a specialization of a
5737 member function of a template class. */
5738 if (name_mangling_version < 1
5739 || tmpl == NULL_TREE
5740 || (member && !is_member_template (tmpl)
5741 && !DECL_TEMPLATE_INFO (tmpl)))
5742 set_mangled_name_for_decl (r);
5744 set_mangled_name_for_template_decl (r);
5748 make_decl_rtl (r, NULL_PTR, 1);
5750 /* Like grokfndecl. If we don't do this, pushdecl will
5751 mess up our TREE_CHAIN because it doesn't find a
5752 previous decl. Sigh. */
5754 && ! uses_template_parms (r)
5755 && (IDENTIFIER_GLOBAL_VALUE (DECL_ASSEMBLER_NAME (r))
5757 SET_IDENTIFIER_GLOBAL_VALUE (DECL_ASSEMBLER_NAME (r), r);
5759 /* We're not supposed to instantiate default arguments
5760 until they are called, for a template. But, for a
5763 template <class T> void f ()
5764 { extern void g(int i = T()); }
5766 we should do the substitution when the template is
5767 instantiated. We handle the member function case in
5768 instantiate_class_template since the default arguments
5769 might refer to other members of the class. */
5771 && !PRIMARY_TEMPLATE_P (gen_tmpl)
5772 && !uses_template_parms (argvec))
5773 tsubst_default_arguments (r);
5776 /* Copy the list of befriending classes. */
5777 for (friends = &DECL_BEFRIENDING_CLASSES (r);
5779 friends = &TREE_CHAIN (*friends))
5781 *friends = copy_node (*friends);
5782 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
5783 args, /*complain=*/1,
5787 if (DECL_CONSTRUCTOR_P (r))
5789 maybe_retrofit_in_chrg (r);
5790 grok_ctor_properties (ctx, r);
5792 else if (DECL_OVERLOADED_OPERATOR_P (r))
5793 grok_op_properties (r, DECL_VIRTUAL_P (r), DECL_FRIEND_P (r));
5800 TREE_TYPE (r) = type;
5801 c_apply_type_quals_to_decl (CP_TYPE_QUALS (type), r);
5803 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
5804 DECL_INITIAL (r) = TREE_TYPE (r);
5806 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
5807 /*complain=*/1, in_decl);
5809 DECL_CONTEXT (r) = NULL_TREE;
5810 if (PROMOTE_PROTOTYPES
5811 && (TREE_CODE (type) == INTEGER_TYPE
5812 || TREE_CODE (type) == ENUMERAL_TYPE)
5813 && TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))
5814 DECL_ARG_TYPE (r) = integer_type_node;
5816 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
5817 /*complain=*/1, TREE_CHAIN (t));
5825 TREE_TYPE (r) = type;
5826 c_apply_type_quals_to_decl (CP_TYPE_QUALS (type), r);
5828 /* We don't have to set DECL_CONTEXT here; it is set by
5829 finish_member_declaration. */
5830 DECL_INITIAL (r) = tsubst_expr (DECL_INITIAL (t), args,
5831 /*complain=*/1, in_decl);
5832 TREE_CHAIN (r) = NULL_TREE;
5833 if (TREE_CODE (type) == VOID_TYPE)
5834 cp_error_at ("instantiation of `%D' as type void", r);
5842 = tsubst_copy (DECL_INITIAL (t), args, /*complain=*/1, in_decl);
5843 TREE_CHAIN (r) = NULL_TREE;
5848 if (DECL_IMPLICIT_TYPEDEF_P (t))
5850 /* For an implicit typedef, we just want the implicit
5851 typedef for the tsubst'd type. We've already got the
5852 tsubst'd type, as TYPE, so we just need it's associated
5854 r = TYPE_NAME (type);
5857 else if (!DECL_LANG_SPECIFIC (t))
5859 /* For a template type parameter, we don't have to do
5860 anything special. */
5861 r = TYPE_NAME (type);
5875 /* Nobody should be tsubst'ing into non-template variables. */
5876 my_friendly_assert (DECL_LANG_SPECIFIC (t)
5877 && DECL_TEMPLATE_INFO (t) != NULL_TREE, 0);
5879 if (TYPE_P (CP_DECL_CONTEXT (t)))
5880 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
5882 in_decl, /*entering_scope=*/1);
5884 /* Subsequent calls to pushdecl will fill this in. */
5887 /* Check to see if we already have this specialization. */
5888 tmpl = DECL_TI_TEMPLATE (t);
5889 gen_tmpl = most_general_template (tmpl);
5890 argvec = tsubst (DECL_TI_ARGS (t), args, /*complain=*/1, in_decl);
5892 spec = retrieve_specialization (gen_tmpl, argvec);
5894 spec = retrieve_local_specialization (gen_tmpl,
5895 current_function_decl);
5903 /* This declaration is going to have to be around for a while,
5904 so me make sure it is on a saveable obstack. */
5907 TREE_TYPE (r) = type;
5908 c_apply_type_quals_to_decl (CP_TYPE_QUALS (type), r);
5909 DECL_CONTEXT (r) = ctx;
5911 /* Don't try to expand the initializer until someone tries to use
5912 this variable; otherwise we run into circular dependencies. */
5913 DECL_INITIAL (r) = NULL_TREE;
5915 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
5918 /* For __PRETTY_FUNCTION__ we have to adjust the initializer. */
5919 if (DECL_PRETTY_FUNCTION_P (r))
5921 DECL_INITIAL (r) = tsubst (DECL_INITIAL (t),
5925 TREE_TYPE (r) = TREE_TYPE (DECL_INITIAL (r));
5928 /* Even if the original location is out of scope, the newly
5929 substituted one is not. */
5930 if (TREE_CODE (r) == VAR_DECL)
5931 DECL_DEAD_FOR_LOCAL (r) = 0;
5933 /* A static data member declaration is always marked external
5934 when it is declared in-class, even if an initializer is
5935 present. We mimic the non-template processing here. */
5937 DECL_EXTERNAL (r) = 1;
5939 DECL_TEMPLATE_INFO (r) = tree_cons (tmpl, argvec, NULL_TREE);
5940 SET_DECL_IMPLICIT_INSTANTIATION (r);
5942 register_specialization (r, gen_tmpl, argvec);
5944 register_local_specialization (r, gen_tmpl,
5945 current_function_decl);
5947 TREE_CHAIN (r) = NULL_TREE;
5948 if (TREE_CODE (r) == VAR_DECL && TREE_CODE (type) == VOID_TYPE)
5949 cp_error_at ("instantiation of `%D' as type void", r);
5954 my_friendly_abort (0);
5957 /* Restore the file and line information. */
5958 lineno = saved_lineno;
5959 input_filename = saved_filename;
5964 /* Substitue into the ARG_TYPES of a function type. */
5967 tsubst_arg_types (arg_types, args, complain, in_decl)
5973 tree remaining_arg_types;
5976 if (!arg_types || arg_types == void_list_node)
5979 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
5980 args, complain, in_decl);
5981 if (remaining_arg_types == error_mark_node)
5982 return error_mark_node;
5984 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
5985 if (type == error_mark_node)
5986 return error_mark_node;
5988 /* Do array-to-pointer, function-to-pointer conversion, and ignore
5989 top-level qualifiers as required. */
5990 type = TYPE_MAIN_VARIANT (type_decays_to (type));
5992 /* Note that we do not substitute into default arguments here. The
5993 standard mandates that they be instantiated only when needed,
5994 which is done in build_over_call. */
5995 return hash_tree_cons (TREE_PURPOSE (arg_types), type,
5996 remaining_arg_types);
6000 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
6001 *not* handle the exception-specification for FNTYPE, because the
6002 initial substitution of explicitly provided template parameters
6003 during argument deduction forbids substitution into the
6004 exception-specification:
6008 All references in the function type of the function template to the
6009 corresponding template parameters are replaced by the specified tem-
6010 plate argument values. If a substitution in a template parameter or
6011 in the function type of the function template results in an invalid
6012 type, type deduction fails. [Note: The equivalent substitution in
6013 exception specifications is done only when the function is instanti-
6014 ated, at which point a program is ill-formed if the substitution
6015 results in an invalid type.] */
6018 tsubst_function_type (t, args, complain, in_decl)
6028 /* The TYPE_CONTEXT is not used for function/method types. */
6029 my_friendly_assert (TYPE_CONTEXT (t) == NULL_TREE, 0);
6031 /* Substitue the return type. */
6032 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
6033 if (return_type == error_mark_node)
6034 return error_mark_node;
6036 /* Substitue the argument types. */
6037 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
6039 if (arg_types == error_mark_node)
6040 return error_mark_node;
6042 /* Construct a new type node and return it. */
6043 if (TREE_CODE (t) == FUNCTION_TYPE)
6044 fntype = build_function_type (return_type, arg_types);
6047 tree r = TREE_TYPE (TREE_VALUE (arg_types));
6048 if (! IS_AGGR_TYPE (r))
6052 Type deduction may fail for any of the following
6055 -- Attempting to create "pointer to member of T" when T
6056 is not a class type. */
6058 cp_error ("creating pointer to member function of non-class type `%T'",
6060 return error_mark_node;
6063 fntype = build_cplus_method_type (r, return_type, TREE_CHAIN
6066 fntype = build_qualified_type (fntype, TYPE_QUALS (t));
6067 fntype = build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
6072 /* Substitute into the PARMS of a call-declarator. */
6075 tsubst_call_declarator_parms (parms, args, complain, in_decl)
6085 if (!parms || parms == void_list_node)
6088 new_parms = tsubst_call_declarator_parms (TREE_CHAIN (parms),
6089 args, complain, in_decl);
6091 /* Figure out the type of this parameter. */
6092 type = tsubst (TREE_VALUE (parms), args, complain, in_decl);
6094 /* Figure out the default argument as well. Note that we use
6095 tsubst_expr since the default argument is really an expression. */
6096 defarg = tsubst_expr (TREE_PURPOSE (parms), args, complain, in_decl);
6098 /* Chain this parameter on to the front of those we have already
6099 processed. We don't use hash_tree_cons because that function
6100 doesn't check TREE_PARMLIST. */
6101 new_parms = tree_cons (defarg, type, new_parms);
6103 /* And note that these are parameters. */
6104 TREE_PARMLIST (new_parms) = 1;
6109 /* Take the tree structure T and replace template parameters used
6110 therein with the argument vector ARGS. IN_DECL is an associated
6111 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
6112 An appropriate error message is issued only if COMPLAIN is
6113 non-zero. Note that we must be relatively non-tolerant of
6114 extensions here, in order to preserve conformance; if we allow
6115 substitutions that should not be allowed, we may allow argument
6116 deductions that should not succeed, and therefore report ambiguous
6117 overload situations where there are none. In theory, we could
6118 allow the substitution, but indicate that it should have failed,
6119 and allow our caller to make sure that the right thing happens, but
6120 we don't try to do this yet.
6122 This function is used for dealing with types, decls and the like;
6123 for expressions, use tsubst_expr or tsubst_copy. */
6126 tsubst (t, args, complain, in_decl)
6133 if (t == NULL_TREE || t == error_mark_node
6134 || t == integer_type_node
6135 || t == void_type_node
6136 || t == char_type_node
6137 || TREE_CODE (t) == NAMESPACE_DECL)
6140 if (TREE_CODE (t) == IDENTIFIER_NODE)
6141 type = IDENTIFIER_TYPE_VALUE (t);
6143 type = TREE_TYPE (t);
6144 if (type == unknown_type_node)
6145 my_friendly_abort (42);
6147 if (type && TREE_CODE (t) != FUNCTION_DECL
6148 && TREE_CODE (t) != TYPENAME_TYPE
6149 && TREE_CODE (t) != TEMPLATE_DECL
6150 && TREE_CODE (t) != IDENTIFIER_NODE
6151 && TREE_CODE (t) != FUNCTION_TYPE
6152 && TREE_CODE (t) != METHOD_TYPE)
6153 type = tsubst (type, args, complain, in_decl);
6154 if (type == error_mark_node)
6155 return error_mark_node;
6158 return tsubst_decl (t, args, type, in_decl);
6160 switch (TREE_CODE (t))
6165 return tsubst_aggr_type (t, args, complain, in_decl,
6166 /*entering_scope=*/0);
6169 case IDENTIFIER_NODE:
6181 if (t == integer_type_node)
6184 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
6185 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
6189 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
6191 max = tsubst_expr (omax, args, complain, in_decl);
6192 if (max == error_mark_node)
6193 return error_mark_node;
6195 /* See if we can reduce this expression to something simpler. */
6196 max = maybe_fold_nontype_arg (max);
6197 if (!processing_template_decl && TREE_READONLY_DECL_P (max))
6198 max = decl_constant_value (max);
6200 if (processing_template_decl
6201 /* When providing explicit arguments to a template
6202 function, but leaving some arguments for subsequent
6203 deduction, MAX may be template-dependent even if we're
6204 not PROCESSING_TEMPLATE_DECL. We still need to check for
6205 template parms, though; MAX won't be an INTEGER_CST for
6206 dynamic arrays, either. */
6207 || (TREE_CODE (max) != INTEGER_CST
6208 && uses_template_parms (max)))
6210 tree itype = make_node (INTEGER_TYPE);
6211 TYPE_MIN_VALUE (itype) = size_zero_node;
6212 TYPE_MAX_VALUE (itype) = build_min (MINUS_EXPR, sizetype, max,
6217 if (integer_zerop (omax))
6219 /* Still allow an explicit array of size zero. */
6221 pedwarn ("creating array with size zero");
6223 else if (integer_zerop (max)
6224 || (TREE_CODE (max) == INTEGER_CST
6225 && INT_CST_LT (max, integer_zero_node)))
6229 Type deduction may fail for any of the following
6232 Attempting to create an array with a size that is
6233 zero or negative. */
6235 cp_error ("creating array with size zero (`%E')", max);
6237 return error_mark_node;
6240 return compute_array_index_type (NULL_TREE, max);
6243 case TEMPLATE_TYPE_PARM:
6244 case TEMPLATE_TEMPLATE_PARM:
6245 case TEMPLATE_PARM_INDEX:
6253 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM
6254 || TREE_CODE (t) == TEMPLATE_TEMPLATE_PARM)
6256 idx = TEMPLATE_TYPE_IDX (t);
6257 level = TEMPLATE_TYPE_LEVEL (t);
6261 idx = TEMPLATE_PARM_IDX (t);
6262 level = TEMPLATE_PARM_LEVEL (t);
6265 if (TREE_VEC_LENGTH (args) > 0)
6267 tree arg = NULL_TREE;
6269 levels = TMPL_ARGS_DEPTH (args);
6270 if (level <= levels)
6271 arg = TMPL_ARG (args, level, idx);
6273 if (arg == error_mark_node)
6274 return error_mark_node;
6275 else if (arg != NULL_TREE)
6277 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
6279 my_friendly_assert (TYPE_P (arg), 0);
6280 return cp_build_qualified_type_real
6281 (arg, CP_TYPE_QUALS (arg) | CP_TYPE_QUALS (t),
6284 else if (TREE_CODE (t) == TEMPLATE_TEMPLATE_PARM)
6286 if (TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t))
6288 /* We are processing a type constructed from
6289 a template template parameter */
6290 tree argvec = tsubst (TYPE_TI_ARGS (t),
6291 args, complain, in_decl);
6292 if (argvec == error_mark_node)
6293 return error_mark_node;
6295 /* We can get a TEMPLATE_TEMPLATE_PARM here when
6296 we are resolving nested-types in the signature of
6297 a member function templates.
6298 Otherwise ARG is a TEMPLATE_DECL and is the real
6299 template to be instantiated. */
6300 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
6301 arg = TYPE_NAME (arg);
6303 r = lookup_template_class (DECL_NAME (arg),
6306 /*entering_scope=*/0);
6307 return cp_build_qualified_type_real (r,
6312 /* We are processing a template argument list. */
6320 my_friendly_abort (981018);
6323 /* This can happen during the attempted tsubst'ing in
6324 unify. This means that we don't yet have any information
6325 about the template parameter in question. */
6328 /* If we get here, we must have been looking at a parm for a
6329 more deeply nested template. Make a new version of this
6330 template parameter, but with a lower level. */
6331 switch (TREE_CODE (t))
6333 case TEMPLATE_TYPE_PARM:
6334 case TEMPLATE_TEMPLATE_PARM:
6336 TEMPLATE_TYPE_PARM_INDEX (r)
6337 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
6339 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
6340 TYPE_MAIN_VARIANT (r) = r;
6341 TYPE_POINTER_TO (r) = NULL_TREE;
6342 TYPE_REFERENCE_TO (r) = NULL_TREE;
6344 if (TREE_CODE (t) == TEMPLATE_TEMPLATE_PARM
6345 && TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t))
6347 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
6349 if (argvec == error_mark_node)
6350 return error_mark_node;
6352 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
6353 = tree_cons (TYPE_NAME (t), argvec, NULL_TREE);
6357 case TEMPLATE_PARM_INDEX:
6358 r = reduce_template_parm_level (t, type, levels);
6362 my_friendly_abort (0);
6370 tree purpose, value, chain, result;
6372 if (t == void_list_node)
6375 purpose = TREE_PURPOSE (t);
6378 purpose = tsubst (purpose, args, complain, in_decl);
6379 if (purpose == error_mark_node)
6380 return error_mark_node;
6382 value = TREE_VALUE (t);
6385 value = tsubst (value, args, complain, in_decl);
6386 if (value == error_mark_node)
6387 return error_mark_node;
6389 chain = TREE_CHAIN (t);
6390 if (chain && chain != void_type_node)
6392 chain = tsubst (chain, args, complain, in_decl);
6393 if (chain == error_mark_node)
6394 return error_mark_node;
6396 if (purpose == TREE_PURPOSE (t)
6397 && value == TREE_VALUE (t)
6398 && chain == TREE_CHAIN (t))
6400 result = hash_tree_cons (purpose, value, chain);
6401 TREE_PARMLIST (result) = TREE_PARMLIST (t);
6405 if (type != NULL_TREE)
6407 /* A binfo node. We always need to make a copy, of the node
6408 itself and of its BINFO_BASETYPES. */
6412 /* Make sure type isn't a typedef copy. */
6413 type = BINFO_TYPE (TYPE_BINFO (type));
6415 TREE_TYPE (t) = complete_type (type);
6416 if (IS_AGGR_TYPE (type))
6418 BINFO_VTABLE (t) = TYPE_BINFO_VTABLE (type);
6419 BINFO_VIRTUALS (t) = TYPE_BINFO_VIRTUALS (type);
6420 if (TYPE_BINFO_BASETYPES (type) != NULL_TREE)
6421 BINFO_BASETYPES (t) = copy_node (TYPE_BINFO_BASETYPES (type));
6426 /* Otherwise, a vector of template arguments. */
6427 return tsubst_template_arg_vector (t, args, complain);
6430 case REFERENCE_TYPE:
6432 enum tree_code code;
6434 if (type == TREE_TYPE (t))
6437 code = TREE_CODE (t);
6442 Type deduction may fail for any of the following
6445 -- Attempting to create a pointer to reference type.
6446 -- Attempting to create a reference to a reference type or
6447 a reference to void. */
6448 if (TREE_CODE (type) == REFERENCE_TYPE
6449 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
6451 static int last_line = 0;
6452 static char* last_file = 0;
6454 /* We keep track of the last time we issued this error
6455 message to avoid spewing a ton of messages during a
6456 single bad template instantiation. */
6457 if (complain && (last_line != lineno ||
6458 last_file != input_filename))
6460 if (TREE_CODE (type) == VOID_TYPE)
6461 cp_error ("forming reference to void");
6463 cp_error ("forming %s to reference type `%T'",
6464 (code == POINTER_TYPE) ? "pointer" : "reference",
6467 last_file = input_filename;
6470 return error_mark_node;
6472 else if (code == POINTER_TYPE)
6473 r = build_pointer_type (type);
6475 r = build_reference_type (type);
6476 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
6478 /* Will this ever be needed for TYPE_..._TO values? */
6484 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
6485 if (r == error_mark_node || !IS_AGGR_TYPE (r))
6489 Type deduction may fail for any of the following
6492 -- Attempting to create "pointer to member of T" when T
6493 is not a class type. */
6495 cp_error ("creating pointer to member of non-class type `%T'",
6497 return error_mark_node;
6499 return build_offset_type (r, type);
6507 fntype = tsubst_function_type (t, args, complain, in_decl);
6508 if (fntype == error_mark_node)
6509 return error_mark_node;
6511 /* Substitue the exception specification. */
6512 raises = TYPE_RAISES_EXCEPTIONS (t);
6515 tree list = NULL_TREE;
6517 if (! TREE_VALUE (raises))
6520 for (; raises != NULL_TREE; raises = TREE_CHAIN (raises))
6522 tree spec = TREE_VALUE (raises);
6524 spec = tsubst (spec, args, complain, in_decl);
6525 if (spec == error_mark_node)
6527 list = add_exception_specifier (list, spec, complain);
6529 fntype = build_exception_variant (fntype, list);
6535 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
6536 if (domain == error_mark_node)
6537 return error_mark_node;
6539 /* As an optimization, we avoid regenerating the array type if
6540 it will obviously be the same as T. */
6541 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
6544 /* These checks should match the ones in grokdeclarator.
6548 The deduction may fail for any of the following reasons:
6550 -- Attempting to create an array with an element type that
6551 is void, a function type, or a reference type. */
6552 if (TREE_CODE (type) == VOID_TYPE
6553 || TREE_CODE (type) == FUNCTION_TYPE
6554 || TREE_CODE (type) == REFERENCE_TYPE)
6557 cp_error ("creating array of `%T'", type);
6558 return error_mark_node;
6561 r = build_cplus_array_type (type, domain);
6568 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain,
6570 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain,
6573 if (e1 == error_mark_node || e2 == error_mark_node)
6574 return error_mark_node;
6576 return fold (build (TREE_CODE (t), TREE_TYPE (t), e1, e2));
6582 tree e = tsubst (TREE_OPERAND (t, 0), args, complain,
6584 if (e == error_mark_node)
6585 return error_mark_node;
6587 return fold (build (TREE_CODE (t), TREE_TYPE (t), e));
6592 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
6593 in_decl, /*entering_scope=*/1);
6594 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
6597 if (ctx == error_mark_node || f == error_mark_node)
6598 return error_mark_node;
6600 if (!IS_AGGR_TYPE (ctx))
6603 cp_error ("`%T' is not a class, struct, or union type",
6605 return error_mark_node;
6607 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
6609 /* Normally, make_typename_type does not require that the CTX
6610 have complete type in order to allow things like:
6612 template <class T> struct S { typename S<T>::X Y; };
6614 But, such constructs have already been resolved by this
6615 point, so here CTX really should have complete type, unless
6616 it's a partial instantiation. */
6617 ctx = complete_type (ctx);
6618 if (!COMPLETE_TYPE_P (ctx))
6621 incomplete_type_error (NULL_TREE, ctx);
6622 return error_mark_node;
6626 f = make_typename_type (ctx, f, complain);
6627 if (f == error_mark_node)
6629 return cp_build_qualified_type_real (f,
6631 | CP_TYPE_QUALS (t),
6637 tree e = tsubst (TREE_OPERAND (t, 0), args, complain,
6639 if (e == error_mark_node)
6640 return error_mark_node;
6641 return make_pointer_declarator (type, e);
6646 tree e = tsubst (TREE_OPERAND (t, 0), args, complain,
6648 if (e == error_mark_node)
6649 return error_mark_node;
6650 return make_reference_declarator (type, e);
6655 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain,
6657 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain,
6659 if (e1 == error_mark_node || e2 == error_mark_node)
6660 return error_mark_node;
6662 return build_parse_node (ARRAY_REF, e1, e2, tsubst_expr);
6667 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain,
6669 tree e2 = (tsubst_call_declarator_parms
6670 (CALL_DECLARATOR_PARMS (t), args, complain, in_decl));
6671 tree e3 = tsubst (CALL_DECLARATOR_EXCEPTION_SPEC (t), args,
6674 if (e1 == error_mark_node || e2 == error_mark_node
6675 || e3 == error_mark_node)
6676 return error_mark_node;
6678 return make_call_declarator (e1, e2, CALL_DECLARATOR_QUALS (t), e3);
6683 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain,
6685 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
6686 if (e1 == error_mark_node || e2 == error_mark_node)
6687 return error_mark_node;
6689 return build_parse_node (TREE_CODE (t), e1, e2);
6694 tree e1 = tsubst_expr (TYPE_FIELDS (t), args, complain,
6696 if (e1 == error_mark_node)
6697 return error_mark_node;
6699 return TREE_TYPE (e1);
6709 /* This code should match declare_hidden_char_array in
6711 name = (*decl_printable_name) (current_function_decl, 2);
6712 len = strlen (name) + 1;
6713 type = build_array_type (char_type_node,
6714 build_index_type (build_int_2 (len, 0)));
6715 str = build_string (len, name);
6716 TREE_TYPE (str) = type;
6721 sorry ("use of `%s' in template",
6722 tree_code_name [(int) TREE_CODE (t)]);
6723 return error_mark_node;
6727 /* Like tsubst, but deals with expressions. This function just replaces
6728 template parms; to finish processing the resultant expression, use
6732 tsubst_copy (t, args, complain, in_decl)
6737 enum tree_code code;
6740 if (t == NULL_TREE || t == error_mark_node)
6743 code = TREE_CODE (t);
6748 return do_identifier (DECL_NAME (t), 0, NULL_TREE);
6755 if (!DECL_CONTEXT (t))
6756 /* This is a global enumeration constant. */
6759 /* Unfortunately, we cannot just call lookup_name here.
6762 template <int I> int f() {
6764 struct S { void g() { E e = a; } };
6767 When we instantiate f<7>::S::g(), say, lookup_name is not
6768 clever enough to find f<7>::a. */
6770 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
6771 /*entering_scope=*/0);
6773 for (v = TYPE_VALUES (enum_type);
6776 if (TREE_PURPOSE (v) == DECL_NAME (t))
6777 return TREE_VALUE (v);
6779 /* We didn't find the name. That should never happen; if
6780 name-lookup found it during preliminary parsing, we
6781 should find it again here during instantiation. */
6782 my_friendly_abort (0);
6787 if (DECL_CONTEXT (t))
6791 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
6792 /*entering_scope=*/1);
6793 if (ctx != DECL_CONTEXT (t))
6794 return lookup_field (ctx, DECL_NAME (t), 0, 0);
6800 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
6801 t = tsubst (t, args, complain, in_decl);
6806 if (is_member_template (t))
6807 return tsubst (t, args, complain, in_decl);
6813 /* We must tsbust into a LOOKUP_EXPR in case the names to
6814 which it refers is a conversion operator; in that case the
6815 name will change. We avoid making unnecessary copies,
6818 tree id = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
6820 if (id != TREE_OPERAND (t, 0))
6822 r = build_nt (LOOKUP_EXPR, id);
6823 LOOKUP_EXPR_GLOBAL (r) = LOOKUP_EXPR_GLOBAL (t);
6831 case REINTERPRET_CAST_EXPR:
6832 case CONST_CAST_EXPR:
6833 case STATIC_CAST_EXPR:
6834 case DYNAMIC_CAST_EXPR:
6837 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
6838 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
6841 case PREDECREMENT_EXPR:
6842 case PREINCREMENT_EXPR:
6843 case POSTDECREMENT_EXPR:
6844 case POSTINCREMENT_EXPR:
6846 case TRUTH_NOT_EXPR:
6849 case CONVERT_EXPR: /* Unary + */
6858 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
6859 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
6864 case TRUNC_DIV_EXPR:
6866 case FLOOR_DIV_EXPR:
6867 case ROUND_DIV_EXPR:
6868 case EXACT_DIV_EXPR:
6870 case BIT_ANDTC_EXPR:
6873 case TRUNC_MOD_EXPR:
6874 case FLOOR_MOD_EXPR:
6875 case TRUTH_ANDIF_EXPR:
6876 case TRUTH_ORIF_EXPR:
6877 case TRUTH_AND_EXPR:
6898 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
6899 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
6903 tree fn = TREE_OPERAND (t, 0);
6904 if (is_overloaded_fn (fn))
6905 fn = tsubst_copy (get_first_fn (fn), args, complain, in_decl);
6907 /* Sometimes FN is a LOOKUP_EXPR. */
6908 fn = tsubst_copy (fn, args, complain, in_decl);
6910 (code, fn, tsubst_copy (TREE_OPERAND (t, 1), args, complain,
6915 case METHOD_CALL_EXPR:
6917 tree name = TREE_OPERAND (t, 0);
6918 if (TREE_CODE (name) == BIT_NOT_EXPR)
6920 name = tsubst_copy (TREE_OPERAND (name, 0), args,
6922 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
6924 else if (TREE_CODE (name) == SCOPE_REF
6925 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
6927 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
6929 name = TREE_OPERAND (name, 1);
6930 name = tsubst_copy (TREE_OPERAND (name, 0), args,
6932 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
6933 name = build_nt (SCOPE_REF, base, name);
6936 name = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
6938 (code, name, tsubst_copy (TREE_OPERAND (t, 1), args,
6940 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl),
6945 /* This processing should really occur in tsubst_expr, However,
6946 tsubst_expr does not recurse into expressions, since it
6947 assumes that there aren't any statements inside them.
6948 Instead, it simply calls build_expr_from_tree. So, we need
6949 to expand the STMT_EXPR here. */
6950 if (!processing_template_decl)
6952 tree stmt_expr = begin_stmt_expr ();
6953 tsubst_expr (STMT_EXPR_STMT (t), args,
6955 return finish_stmt_expr (stmt_expr);
6962 case PSEUDO_DTOR_EXPR:
6965 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
6966 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
6967 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
6974 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
6975 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
6976 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
6977 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
6984 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
6985 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
6986 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
6987 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
6991 case TEMPLATE_ID_EXPR:
6993 /* Substituted template arguments */
6994 tree targs = tsubst_copy (TREE_OPERAND (t, 1), args, complain,
6997 if (targs && TREE_CODE (targs) == TREE_LIST)
7000 for (chain = targs; chain; chain = TREE_CHAIN (chain))
7001 TREE_VALUE (chain) = maybe_fold_nontype_arg (TREE_VALUE (chain));
7006 for (i = 0; i < TREE_VEC_LENGTH (targs); ++i)
7007 TREE_VEC_ELT (targs, i)
7008 = maybe_fold_nontype_arg (TREE_VEC_ELT (targs, i));
7011 return lookup_template_function
7012 (tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl), targs);
7017 tree purpose, value, chain;
7019 if (t == void_list_node)
7022 purpose = TREE_PURPOSE (t);
7024 purpose = tsubst_copy (purpose, args, complain, in_decl);
7025 value = TREE_VALUE (t);
7027 value = tsubst_copy (value, args, complain, in_decl);
7028 chain = TREE_CHAIN (t);
7029 if (chain && chain != void_type_node)
7030 chain = tsubst_copy (chain, args, complain, in_decl);
7031 if (purpose == TREE_PURPOSE (t)
7032 && value == TREE_VALUE (t)
7033 && chain == TREE_CHAIN (t))
7035 return tree_cons (purpose, value, chain);
7042 case TEMPLATE_TYPE_PARM:
7043 case TEMPLATE_TEMPLATE_PARM:
7044 case TEMPLATE_PARM_INDEX:
7046 case REFERENCE_TYPE:
7053 return tsubst (t, args, complain, in_decl);
7055 case IDENTIFIER_NODE:
7056 if (IDENTIFIER_TYPENAME_P (t)
7057 /* Make sure it's not just a variable named `__opr', for instance,
7058 which can occur in some existing code. */
7060 return build_typename_overload
7061 (tsubst (TREE_TYPE (t), args, complain, in_decl));
7068 (CONSTRUCTOR, tsubst (TREE_TYPE (t), args, complain, in_decl),
7069 NULL_TREE, tsubst_copy (CONSTRUCTOR_ELTS (t), args,
7070 complain, in_decl));
7071 TREE_HAS_CONSTRUCTOR (r) = TREE_HAS_CONSTRUCTOR (t);
7076 return build_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
7078 tsubst (TREE_TYPE (t), args, complain, in_decl));
7081 return tsubst (t, args, complain, in_decl);
7088 /* Like tsubst_copy, but also does semantic processing. */
7091 tsubst_expr (t, args, complain, in_decl)
7098 if (t == NULL_TREE || t == error_mark_node)
7101 if (processing_template_decl)
7102 return tsubst_copy (t, args, complain, in_decl);
7104 switch (TREE_CODE (t))
7108 finish_named_return_value
7109 (TREE_OPERAND (t, 0),
7110 tsubst_expr (TREE_OPERAND (t, 1), args, /*complain=*/1, in_decl));
7111 tsubst_expr (TREE_CHAIN (t), args, complain, in_decl);
7114 case CTOR_INITIALIZER:
7116 current_member_init_list
7117 = tsubst_expr_values (TREE_OPERAND (t, 0), args);
7118 current_base_init_list
7119 = tsubst_expr_values (TREE_OPERAND (t, 1), args);
7121 tsubst_expr (TREE_CHAIN (t), args, complain, in_decl);
7126 finish_return_stmt (tsubst_expr (RETURN_EXPR (t),
7127 args, complain, in_decl));
7132 finish_expr_stmt (tsubst_expr (EXPR_STMT_EXPR (t),
7133 args, complain, in_decl));
7142 decl = DECL_STMT_DECL (t);
7143 if (TREE_CODE (decl) == LABEL_DECL)
7144 finish_label_decl (DECL_NAME (decl));
7147 init = DECL_INITIAL (decl);
7148 decl = tsubst (decl, args, complain, in_decl);
7149 init = tsubst_expr (init, args, complain, in_decl);
7151 DECL_INITIAL (decl) = error_mark_node;
7152 /* By marking the declaration as instantiated, we avoid
7153 trying to instantiate it. Since instantiate_decl can't
7154 handle local variables, and since we've already done
7155 all that needs to be done, that's the right thing to
7157 if (TREE_CODE (decl) == VAR_DECL)
7158 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
7159 maybe_push_decl (decl);
7160 cp_finish_decl (decl, init, NULL_TREE, 0);
7170 stmt = begin_for_stmt ();
7171 for (tmp = FOR_INIT_STMT (t); tmp; tmp = TREE_CHAIN (tmp))
7172 tsubst_expr (tmp, args, complain, in_decl);
7173 finish_for_init_stmt (stmt);
7174 finish_for_cond (tsubst_expr (FOR_COND (t), args,
7177 tmp = tsubst_expr (FOR_EXPR (t), args, complain, in_decl);
7178 finish_for_expr (tmp, stmt);
7179 tsubst_expr (FOR_BODY (t), args, complain, in_decl);
7180 finish_for_stmt (tmp, stmt);
7187 stmt = begin_while_stmt ();
7188 finish_while_stmt_cond (tsubst_expr (WHILE_COND (t),
7189 args, complain, in_decl),
7191 tsubst_expr (WHILE_BODY (t), args, complain, in_decl);
7192 finish_while_stmt (stmt);
7199 stmt = begin_do_stmt ();
7200 tsubst_expr (DO_BODY (t), args, complain, in_decl);
7201 finish_do_body (stmt);
7202 finish_do_stmt (tsubst_expr (DO_COND (t), args,
7213 stmt = begin_if_stmt ();
7214 finish_if_stmt_cond (tsubst_expr (IF_COND (t),
7215 args, complain, in_decl),
7218 if (tmp = THEN_CLAUSE (t), tmp)
7220 tsubst_expr (tmp, args, complain, in_decl);
7221 finish_then_clause (stmt);
7224 if (tmp = ELSE_CLAUSE (t), tmp)
7226 begin_else_clause ();
7227 tsubst_expr (tmp, args, complain, in_decl);
7228 finish_else_clause (stmt);
7240 stmt = begin_compound_stmt (COMPOUND_STMT_NO_SCOPE (t));
7241 for (substmt = COMPOUND_BODY (t);
7242 substmt != NULL_TREE;
7243 substmt = TREE_CHAIN (substmt))
7244 tsubst_expr (substmt, args, complain, in_decl);
7245 return finish_compound_stmt (COMPOUND_STMT_NO_SCOPE (t), stmt);
7251 finish_break_stmt ();
7256 finish_continue_stmt ();
7264 stmt = begin_switch_stmt ();
7265 val = tsubst_expr (SWITCH_COND (t), args, complain, in_decl);
7266 finish_switch_cond (val, stmt);
7267 tsubst_expr (SWITCH_BODY (t), args, complain, in_decl);
7268 finish_switch_stmt (val, stmt);
7274 finish_case_label (tsubst_expr (CASE_LOW (t), args, complain, in_decl),
7275 tsubst_expr (CASE_HIGH (t), args, complain, in_decl));
7279 lineno = STMT_LINENO (t);
7280 finish_label_stmt (DECL_NAME (LABEL_STMT_LABEL (t)));
7285 t = GOTO_DESTINATION (t);
7286 if (TREE_CODE (t) != LABEL_DECL)
7287 /* Computed goto's must be tsubst'd into. On the other hand,
7288 non-computed gotos must not be; the identifier in question
7289 will have no binding. */
7290 t = tsubst_expr (t, args, complain, in_decl);
7293 finish_goto_stmt (t);
7298 finish_asm_stmt (ASM_CV_QUAL (t),
7299 tsubst_expr (ASM_STRING (t), args, complain, in_decl),
7300 tsubst_expr (ASM_OUTPUTS (t), args, complain, in_decl),
7301 tsubst_expr (ASM_INPUTS (t), args, complain, in_decl),
7302 tsubst_expr (ASM_CLOBBERS (t), args, complain,
7310 stmt = begin_try_block ();
7311 tsubst_expr (TRY_STMTS (t), args, complain, in_decl);
7312 finish_cleanup_try_block (stmt);
7313 finish_cleanup (tsubst_expr (TRY_HANDLERS (t), args,
7321 if (FN_TRY_BLOCK_P (t))
7322 stmt = begin_function_try_block ();
7324 stmt = begin_try_block ();
7326 tsubst_expr (TRY_STMTS (t), args, complain, in_decl);
7328 if (FN_TRY_BLOCK_P (t))
7329 finish_function_try_block (stmt);
7331 finish_try_block (stmt);
7333 handler = TRY_HANDLERS (t);
7334 for (; handler; handler = TREE_CHAIN (handler))
7335 tsubst_expr (handler, args, complain, in_decl);
7336 if (FN_TRY_BLOCK_P (t))
7337 finish_function_handler_sequence (stmt);
7339 finish_handler_sequence (stmt);
7349 stmt = begin_handler ();
7350 if (HANDLER_PARMS (t))
7352 decl = DECL_STMT_DECL (HANDLER_PARMS (t));
7353 decl = tsubst (decl, args, complain, in_decl);
7354 /* Prevent instantiate_decl from trying to instantiate
7355 this variable. We've already done all that needs to be
7357 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
7361 blocks = finish_handler_parms (decl, stmt);
7362 tsubst_expr (HANDLER_BODY (t), args, complain, in_decl);
7363 finish_handler (blocks, stmt);
7370 tsubst (t, args, complain, NULL_TREE);
7374 return build_expr_from_tree (tsubst_copy (t, args, complain, in_decl));
7379 /* Instantiate the indicated variable or function template TMPL with
7380 the template arguments in TARG_PTR. */
7383 instantiate_template (tmpl, targ_ptr)
7384 tree tmpl, targ_ptr;
7392 if (tmpl == error_mark_node)
7393 return error_mark_node;
7395 my_friendly_assert (TREE_CODE (tmpl) == TEMPLATE_DECL, 283);
7397 /* Check to see if we already have this specialization. */
7398 spec = retrieve_specialization (tmpl, targ_ptr);
7399 if (spec != NULL_TREE)
7402 if (DECL_TEMPLATE_INFO (tmpl) && !DECL_TEMPLATE_SPECIALIZATION (tmpl))
7404 /* The TMPL is a partial instantiation. To get a full set of
7405 arguments we must add the arguments used to perform the
7406 partial instantiation. */
7407 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
7409 gen_tmpl = most_general_template (tmpl);
7411 /* Check to see if we already have this specialization. */
7412 spec = retrieve_specialization (gen_tmpl, targ_ptr);
7413 if (spec != NULL_TREE)
7419 len = DECL_NTPARMS (gen_tmpl);
7420 inner_args = innermost_args (targ_ptr);
7424 tree t = TREE_VEC_ELT (inner_args, i);
7427 tree nt = target_type (t);
7428 if (IS_AGGR_TYPE (nt) && decl_function_context (TYPE_MAIN_DECL (nt)))
7430 cp_error ("type `%T' composed from a local class is not a valid template-argument", t);
7431 cp_error (" trying to instantiate `%D'", gen_tmpl);
7432 fndecl = error_mark_node;
7438 /* substitute template parameters */
7439 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
7440 targ_ptr, /*complain=*/1, gen_tmpl);
7441 /* The DECL_TI_TEMPLATE should always be the immediate parent
7442 template, not the most general template. */
7443 DECL_TI_TEMPLATE (fndecl) = tmpl;
7445 if (flag_external_templates)
7446 add_pending_template (fndecl);
7452 /* Push the name of the class template into the scope of the instantiation. */
7455 overload_template_name (type)
7458 tree id = DECL_NAME (CLASSTYPE_TI_TEMPLATE (type));
7461 if (IDENTIFIER_CLASS_VALUE (id)
7462 && TREE_TYPE (IDENTIFIER_CLASS_VALUE (id)) == type)
7465 decl = build_decl (TYPE_DECL, id, type);
7466 SET_DECL_ARTIFICIAL (decl);
7467 pushdecl_class_level (decl);
7470 /* The FN is a TEMPLATE_DECL for a function. The ARGS are the
7471 arguments that are being used when calling it. TARGS is a vector
7472 into which the deduced template arguments are placed.
7474 Return zero for success, 2 for an incomplete match that doesn't resolve
7475 all the types, and 1 for complete failure. An error message will be
7476 printed only for an incomplete match.
7478 If FN is a conversion operator, RETURN_TYPE is the type desired as
7479 the result of the conversion operator.
7481 TPARMS is a vector of template parameters.
7483 The EXPLICIT_TARGS are explicit template arguments provided via a
7486 The parameter STRICT is one of:
7489 We are deducing arguments for a function call, as in
7493 We are deducing arguments for a conversion function, as in
7497 We are deducing arguments when calculating the partial
7498 ordering between specializations of function or class
7499 templates, as in [temp.func.order] and [temp.class.order],
7500 when doing an explicit instantiation as in [temp.explicit],
7501 when determining an explicit specialization as in
7502 [temp.expl.spec], or when taking the address of a function
7503 template, as in [temp.deduct.funcaddr].
7505 The other arguments are as for type_unification. */
7508 fn_type_unification (fn, explicit_targs, targs, args, return_type,
7510 tree fn, explicit_targs, targs, args, return_type;
7511 unification_kind_t strict;
7517 my_friendly_assert (TREE_CODE (fn) == TEMPLATE_DECL, 0);
7519 fntype = TREE_TYPE (fn);
7524 The specified template arguments must match the template
7525 parameters in kind (i.e., type, nontype, template), and there
7526 must not be more arguments than there are parameters;
7527 otherwise type deduction fails.
7529 Nontype arguments must match the types of the corresponding
7530 nontype template parameters, or must be convertible to the
7531 types of the corresponding nontype parameters as specified in
7532 _temp.arg.nontype_, otherwise type deduction fails.
7534 All references in the function type of the function template
7535 to the corresponding template parameters are replaced by the
7536 specified template argument values. If a substitution in a
7537 template parameter or in the function type of the function
7538 template results in an invalid type, type deduction fails. */
7540 tree converted_args;
7543 = (coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
7544 explicit_targs, NULL_TREE, /*complain=*/0,
7545 /*require_all_arguments=*/0));
7546 if (converted_args == error_mark_node)
7549 fntype = tsubst (fntype, converted_args, /*complain=*/0, NULL_TREE);
7550 if (fntype == error_mark_node)
7553 /* Place the explicitly specified arguments in TARGS. */
7554 for (i = 0; i < TREE_VEC_LENGTH (targs); i++)
7555 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
7558 parms = TYPE_ARG_TYPES (fntype);
7560 if (DECL_CONV_FN_P (fn))
7562 /* This is a template conversion operator. Remove `this', since
7563 we could be comparing conversions from different classes. */
7564 parms = TREE_CHAIN (parms);
7565 args = TREE_CHAIN (args);
7566 my_friendly_assert (return_type != NULL_TREE, 20000227);
7571 /* We've been given a return type to match, prepend it. */
7572 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
7573 args = tree_cons (NULL_TREE, return_type, args);
7576 /* We allow incomplete unification without an error message here
7577 because the standard doesn't seem to explicitly prohibit it. Our
7578 callers must be ready to deal with unification failures in any
7580 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
7581 targs, parms, args, /*subr=*/0,
7582 strict, /*allow_incomplete*/1);
7585 /* All is well so far. Now, check:
7589 When all template arguments have been deduced, all uses of
7590 template parameters in nondeduced contexts are replaced with
7591 the corresponding deduced argument values. If the
7592 substitution results in an invalid type, as described above,
7593 type deduction fails. */
7594 if (tsubst (TREE_TYPE (fn), targs, /*complain=*/0, NULL_TREE)
7601 /* Adjust types before performing type deduction, as described in
7602 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
7603 sections are symmetric. PARM is the type of a function parameter
7604 or the return type of the conversion function. ARG is the type of
7605 the argument passed to the call, or the type of the value
7606 intialized with the result of the conversion function. */
7609 maybe_adjust_types_for_deduction (strict, parm, arg)
7610 unification_kind_t strict;
7621 /* Swap PARM and ARG throughout the remainder of this
7622 function; the handling is precisely symmetric since PARM
7623 will initialize ARG rather than vice versa. */
7631 /* There is nothing to do in this case. */
7635 my_friendly_abort (0);
7638 if (TREE_CODE (*parm) != REFERENCE_TYPE)
7640 /* [temp.deduct.call]
7642 If P is not a reference type:
7644 --If A is an array type, the pointer type produced by the
7645 array-to-pointer standard conversion (_conv.array_) is
7646 used in place of A for type deduction; otherwise,
7648 --If A is a function type, the pointer type produced by
7649 the function-to-pointer standard conversion
7650 (_conv.func_) is used in place of A for type deduction;
7653 --If A is a cv-qualified type, the top level
7654 cv-qualifiers of A's type are ignored for type
7656 if (TREE_CODE (*arg) == ARRAY_TYPE)
7657 *arg = build_pointer_type (TREE_TYPE (*arg));
7658 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
7659 *arg = build_pointer_type (*arg);
7661 *arg = TYPE_MAIN_VARIANT (*arg);
7664 /* [temp.deduct.call]
7666 If P is a cv-qualified type, the top level cv-qualifiers
7667 of P's type are ignored for type deduction. If P is a
7668 reference type, the type referred to by P is used for
7670 *parm = TYPE_MAIN_VARIANT (*parm);
7671 if (TREE_CODE (*parm) == REFERENCE_TYPE)
7672 *parm = TREE_TYPE (*parm);
7675 /* Like type_unfication.
7677 If SUBR is 1, we're being called recursively (to unify the
7678 arguments of a function or method parameter of a function
7682 type_unification_real (tparms, targs, parms, args, subr,
7683 strict, allow_incomplete)
7684 tree tparms, targs, parms, args;
7686 unification_kind_t strict;
7687 int allow_incomplete;
7691 int ntparms = TREE_VEC_LENGTH (tparms);
7694 my_friendly_assert (TREE_CODE (tparms) == TREE_VEC, 289);
7695 my_friendly_assert (parms == NULL_TREE
7696 || TREE_CODE (parms) == TREE_LIST, 290);
7697 /* ARGS could be NULL (via a call from parse.y to
7698 build_x_function_call). */
7700 my_friendly_assert (TREE_CODE (args) == TREE_LIST, 291);
7701 my_friendly_assert (ntparms > 0, 292);
7706 sub_strict = UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_DERIVED;
7710 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
7714 sub_strict = UNIFY_ALLOW_NONE;
7718 my_friendly_abort (0);
7722 && parms != void_list_node
7724 && args != void_list_node)
7726 parm = TREE_VALUE (parms);
7727 parms = TREE_CHAIN (parms);
7728 arg = TREE_VALUE (args);
7729 args = TREE_CHAIN (args);
7731 if (arg == error_mark_node)
7733 if (arg == unknown_type_node)
7734 /* We can't deduce anything from this, but we might get all the
7735 template args from other function args. */
7738 /* Conversions will be performed on a function argument that
7739 corresponds with a function parameter that contains only
7740 non-deducible template parameters and explicitly specified
7741 template parameters. */
7742 if (! uses_template_parms (parm))
7747 type = TREE_TYPE (arg);
7754 if (strict == DEDUCE_EXACT)
7756 if (same_type_p (parm, type))
7760 /* It might work; we shouldn't check now, because we might
7761 get into infinite recursion. Overload resolution will
7770 my_friendly_assert (TREE_TYPE (arg) != NULL_TREE, 293);
7771 if (type_unknown_p (arg))
7773 /* [temp.deduct.type] A template-argument can be deduced from
7774 a pointer to function or pointer to member function
7775 argument if the set of overloaded functions does not
7776 contain function templates and at most one of a set of
7777 overloaded functions provides a unique match. */
7779 if (resolve_overloaded_unification
7780 (tparms, targs, parm, arg, strict, sub_strict)
7785 arg = TREE_TYPE (arg);
7789 maybe_adjust_types_for_deduction (strict, &parm, &arg);
7791 switch (unify (tparms, targs, parm, arg, sub_strict))
7799 /* Fail if we've reached the end of the parm list, and more args
7800 are present, and the parm list isn't variadic. */
7801 if (args && args != void_list_node && parms == void_list_node)
7803 /* Fail if parms are left and they don't have default values. */
7805 && parms != void_list_node
7806 && TREE_PURPOSE (parms) == NULL_TREE)
7809 for (i = 0; i < ntparms; i++)
7810 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
7812 if (!allow_incomplete)
7813 error ("incomplete type unification");
7819 /* Subroutine of type_unification_real. Args are like the variables at the
7820 call site. ARG is an overloaded function (or template-id); we try
7821 deducing template args from each of the overloads, and if only one
7822 succeeds, we go with that. Modifies TARGS and returns 0 on success. */
7825 resolve_overloaded_unification (tparms, targs, parm, arg, strict,
7827 tree tparms, targs, parm, arg;
7828 unification_kind_t strict;
7831 tree tempargs = copy_node (targs);
7834 if (TREE_CODE (arg) == ADDR_EXPR)
7835 arg = TREE_OPERAND (arg, 0);
7837 if (TREE_CODE (arg) == COMPONENT_REF)
7838 /* Handle `&x' where `x' is some static or non-static member
7840 arg = TREE_OPERAND (arg, 1);
7842 if (TREE_CODE (arg) == OFFSET_REF)
7843 arg = TREE_OPERAND (arg, 1);
7845 /* Strip baselink information. */
7846 while (TREE_CODE (arg) == TREE_LIST)
7847 arg = TREE_VALUE (arg);
7849 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
7851 /* If we got some explicit template args, we need to plug them into
7852 the affected templates before we try to unify, in case the
7853 explicit args will completely resolve the templates in question. */
7855 tree expl_subargs = TREE_OPERAND (arg, 1);
7856 arg = TREE_OPERAND (arg, 0);
7858 for (; arg; arg = OVL_NEXT (arg))
7860 tree fn = OVL_CURRENT (arg);
7863 if (TREE_CODE (fn) != TEMPLATE_DECL)
7866 subargs = get_bindings_overload (fn, DECL_TEMPLATE_RESULT (fn),
7870 elem = tsubst (TREE_TYPE (fn), subargs, /*complain=*/0,
7872 if (TREE_CODE (elem) == METHOD_TYPE)
7873 elem = build_ptrmemfunc_type (build_pointer_type (elem));
7874 good += try_one_overload (tparms, targs, tempargs, parm, elem,
7875 strict, sub_strict);
7879 else if (TREE_CODE (arg) == OVERLOAD)
7881 for (; arg; arg = OVL_NEXT (arg))
7883 tree type = TREE_TYPE (OVL_CURRENT (arg));
7884 if (TREE_CODE (type) == METHOD_TYPE)
7885 type = build_ptrmemfunc_type (build_pointer_type (type));
7886 good += try_one_overload (tparms, targs, tempargs, parm,
7888 strict, sub_strict);
7892 my_friendly_abort (981006);
7894 /* [temp.deduct.type] A template-argument can be deduced from a pointer
7895 to function or pointer to member function argument if the set of
7896 overloaded functions does not contain function templates and at most
7897 one of a set of overloaded functions provides a unique match.
7899 So if we found multiple possibilities, we return success but don't
7904 int i = TREE_VEC_LENGTH (targs);
7906 if (TREE_VEC_ELT (tempargs, i))
7907 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
7915 /* Subroutine of resolve_overloaded_unification; does deduction for a single
7916 overload. Fills TARGS with any deduced arguments, or error_mark_node if
7917 different overloads deduce different arguments for a given parm.
7918 Returns 1 on success. */
7921 try_one_overload (tparms, orig_targs, targs, parm, arg, strict,
7923 tree tparms, orig_targs, targs, parm, arg;
7924 unification_kind_t strict;
7931 /* [temp.deduct.type] A template-argument can be deduced from a pointer
7932 to function or pointer to member function argument if the set of
7933 overloaded functions does not contain function templates and at most
7934 one of a set of overloaded functions provides a unique match.
7936 So if this is a template, just return success. */
7938 if (uses_template_parms (arg))
7941 maybe_adjust_types_for_deduction (strict, &parm, &arg);
7943 /* We don't copy orig_targs for this because if we have already deduced
7944 some template args from previous args, unify would complain when we
7945 try to deduce a template parameter for the same argument, even though
7946 there isn't really a conflict. */
7947 nargs = TREE_VEC_LENGTH (targs);
7948 tempargs = make_tree_vec (nargs);
7950 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
7953 /* First make sure we didn't deduce anything that conflicts with
7954 explicitly specified args. */
7955 for (i = nargs; i--; )
7957 tree elt = TREE_VEC_ELT (tempargs, i);
7958 tree oldelt = TREE_VEC_ELT (orig_targs, i);
7960 if (elt == NULL_TREE)
7962 else if (uses_template_parms (elt))
7964 /* Since we're unifying against ourselves, we will fill in template
7965 args used in the function parm list with our own template parms.
7967 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
7970 else if (oldelt && ! template_args_equal (oldelt, elt))
7974 for (i = nargs; i--; )
7976 tree elt = TREE_VEC_ELT (tempargs, i);
7979 TREE_VEC_ELT (targs, i) = elt;
7985 /* PARM is a template class (perhaps with unbound template
7986 parameters). ARG is a fully instantiated type. If ARG can be
7987 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
7988 TARGS are as for unify. */
7991 try_class_unification (tparms, targs, parm, arg)
8000 if (!CLASSTYPE_TEMPLATE_INFO (arg)
8001 || CLASSTYPE_TI_TEMPLATE (arg) != CLASSTYPE_TI_TEMPLATE (parm))
8004 /* We need to make a new template argument vector for the call to
8005 unify. If we used TARGS, we'd clutter it up with the result of
8006 the attempted unification, even if this class didn't work out.
8007 We also don't want to commit ourselves to all the unifications
8008 we've already done, since unification is supposed to be done on
8009 an argument-by-argument basis. In other words, consider the
8010 following pathological case:
8012 template <int I, int J, int K>
8015 template <int I, int J>
8016 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
8018 template <int I, int J, int K>
8019 void f(S<I, J, K>, S<I, I, I>);
8028 Now, by the time we consider the unification involving `s2', we
8029 already know that we must have `f<0, 0, 0>'. But, even though
8030 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is not legal
8031 because there are two ways to unify base classes of S<0, 1, 2>
8032 with S<I, I, I>. If we kept the already deduced knowledge, we
8033 would reject the possibility I=1. */
8034 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
8035 i = unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
8036 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE);
8038 /* If unification failed, we're done. */
8045 /* Subroutine of get_template_base. RVAL, if non-NULL, is a base we
8046 have alreay discovered to be satisfactory. ARG_BINFO is the binfo
8047 for the base class of ARG that we are currently examining. */
8050 get_template_base_recursive (tparms, targs, parm,
8051 arg_binfo, rval, flags)
8061 tree arg = BINFO_TYPE (arg_binfo);
8063 if (!(flags & GTB_IGNORE_TYPE))
8065 tree r = try_class_unification (tparms, targs,
8068 /* If there is more than one satisfactory baseclass, then:
8072 If they yield more than one possible deduced A, the type
8076 if (r && rval && !same_type_p (r, rval))
8077 return error_mark_node;
8082 binfos = BINFO_BASETYPES (arg_binfo);
8083 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
8085 /* Process base types. */
8086 for (i = 0; i < n_baselinks; i++)
8088 tree base_binfo = TREE_VEC_ELT (binfos, i);
8091 /* Skip this base, if we've already seen it. */
8092 if (BINFO_MARKED (base_binfo))
8096 (flags & GTB_VIA_VIRTUAL) || TREE_VIA_VIRTUAL (base_binfo);
8098 /* When searching for a non-virtual, we cannot mark virtually
8101 SET_BINFO_MARKED (base_binfo);
8103 rval = get_template_base_recursive (tparms, targs,
8107 GTB_VIA_VIRTUAL * this_virtual);
8109 /* If we discovered more than one matching base class, we can
8111 if (rval == error_mark_node)
8112 return error_mark_node;
8118 /* Given a template type PARM and a class type ARG, find the unique
8119 base type in ARG that is an instance of PARM. We do not examine
8120 ARG itself; only its base-classes. If there is no appropriate base
8121 class, return NULL_TREE. If there is more than one, return
8122 error_mark_node. PARM may be the type of a partial specialization,
8123 as well as a plain template type. Used by unify. */
8126 get_template_base (tparms, targs, parm, arg)
8135 my_friendly_assert (IS_AGGR_TYPE_CODE (TREE_CODE (arg)), 92);
8137 arg_binfo = TYPE_BINFO (complete_type (arg));
8138 rval = get_template_base_recursive (tparms, targs,
8143 /* Since get_template_base_recursive marks the bases classes, we
8144 must unmark them here. */
8145 dfs_walk (arg_binfo, dfs_unmark, markedp, 0);
8150 /* Returns the level of DECL, which declares a template parameter. */
8153 template_decl_level (decl)
8156 switch (TREE_CODE (decl))
8160 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
8163 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
8166 my_friendly_abort (0);
8171 /* Decide whether ARG can be unified with PARM, considering only the
8172 cv-qualifiers of each type, given STRICT as documented for unify.
8173 Returns non-zero iff the unification is OK on that basis.*/
8176 check_cv_quals_for_unify (strict, arg, parm)
8181 if (!(strict & UNIFY_ALLOW_MORE_CV_QUAL)
8182 && !at_least_as_qualified_p (arg, parm))
8185 if (!(strict & UNIFY_ALLOW_LESS_CV_QUAL)
8186 && !at_least_as_qualified_p (parm, arg))
8192 /* Takes parameters as for type_unification. Returns 0 if the
8193 type deduction suceeds, 1 otherwise. The parameter STRICT is a
8194 bitwise or of the following flags:
8197 Require an exact match between PARM and ARG.
8198 UNIFY_ALLOW_MORE_CV_QUAL:
8199 Allow the deduced ARG to be more cv-qualified than ARG.
8200 UNIFY_ALLOW_LESS_CV_QUAL:
8201 Allow the deduced ARG to be less cv-qualified than ARG.
8202 UNIFY_ALLOW_DERIVED:
8203 Allow the deduced ARG to be a template base class of ARG,
8204 or a pointer to a template base class of the type pointed to by
8206 UNIFY_ALLOW_INTEGER:
8207 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
8208 case for more information. */
8211 unify (tparms, targs, parm, arg, strict)
8212 tree tparms, targs, parm, arg;
8219 /* I don't think this will do the right thing with respect to types.
8220 But the only case I've seen it in so far has been array bounds, where
8221 signedness is the only information lost, and I think that will be
8223 while (TREE_CODE (parm) == NOP_EXPR)
8224 parm = TREE_OPERAND (parm, 0);
8226 if (arg == error_mark_node)
8228 if (arg == unknown_type_node)
8229 /* We can't deduce anything from this, but we might get all the
8230 template args from other function args. */
8233 /* If PARM uses template parameters, then we can't bail out here,
8234 even if ARG == PARM, since we won't record unifications for the
8235 template parameters. We might need them if we're trying to
8236 figure out which of two things is more specialized. */
8237 if (arg == parm && !uses_template_parms (parm))
8240 /* Immediately reject some pairs that won't unify because of
8241 cv-qualification mismatches. */
8242 if (TREE_CODE (arg) == TREE_CODE (parm)
8244 /* We check the cv-qualifiers when unifying with template type
8245 parameters below. We want to allow ARG `const T' to unify with
8246 PARM `T' for example, when computing which of two templates
8247 is more specialized, for example. */
8248 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
8249 && !check_cv_quals_for_unify (strict, arg, parm))
8252 switch (TREE_CODE (parm))
8255 /* In a type which contains a nested-name-specifier, template
8256 argument values cannot be deduced for template parameters used
8257 within the nested-name-specifier. */
8260 case TEMPLATE_TYPE_PARM:
8261 case TEMPLATE_TEMPLATE_PARM:
8262 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
8264 if (TEMPLATE_TYPE_LEVEL (parm)
8265 != template_decl_level (tparm))
8266 /* The PARM is not one we're trying to unify. Just check
8267 to see if it matches ARG. */
8268 return (TREE_CODE (arg) == TREE_CODE (parm)
8269 && same_type_p (parm, arg)) ? 0 : 1;
8270 idx = TEMPLATE_TYPE_IDX (parm);
8271 targ = TREE_VEC_ELT (targs, idx);
8272 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
8274 /* Check for mixed types and values. */
8275 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
8276 && TREE_CODE (tparm) != TYPE_DECL)
8277 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
8278 && TREE_CODE (tparm) != TEMPLATE_DECL))
8281 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
8283 if (TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (parm))
8285 /* We arrive here when PARM does not involve template
8288 /* ARG must be constructed from a template class. */
8289 if (TREE_CODE (arg) != RECORD_TYPE || !CLASSTYPE_TEMPLATE_INFO (arg))
8293 tree parmtmpl = TYPE_TI_TEMPLATE (parm);
8294 tree parmvec = TYPE_TI_ARGS (parm);
8295 tree argvec = CLASSTYPE_TI_ARGS (arg);
8297 = DECL_INNERMOST_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (arg));
8300 /* The parameter and argument roles have to be switched here
8301 in order to handle default arguments properly. For example,
8302 template<template <class> class TT> void f(TT<int>)
8303 should be able to accept vector<int> which comes from
8304 template <class T, class Allocator = allocator>
8307 if (coerce_template_parms (argtmplvec, parmvec, parmtmpl, 0, 1)
8311 /* Deduce arguments T, i from TT<T> or TT<i>.
8312 We check each element of PARMVEC and ARGVEC individually
8313 rather than the whole TREE_VEC since they can have
8314 different number of elements. */
8316 for (i = 0; i < TREE_VEC_LENGTH (parmvec); ++i)
8318 tree t = TREE_VEC_ELT (parmvec, i);
8320 if (unify (tparms, targs, t,
8321 TREE_VEC_ELT (argvec, i),
8326 arg = CLASSTYPE_TI_TEMPLATE (arg);
8331 /* If PARM is `const T' and ARG is only `int', we don't have
8332 a match unless we are allowing additional qualification.
8333 If ARG is `const int' and PARM is just `T' that's OK;
8334 that binds `const int' to `T'. */
8335 if (!check_cv_quals_for_unify (strict | UNIFY_ALLOW_LESS_CV_QUAL,
8339 /* Consider the case where ARG is `const volatile int' and
8340 PARM is `const T'. Then, T should be `volatile int'. */
8342 cp_build_qualified_type_real (arg,
8344 & ~CP_TYPE_QUALS (parm),
8346 if (arg == error_mark_node)
8350 /* Simple cases: Value already set, does match or doesn't. */
8351 if (targ != NULL_TREE && same_type_p (targ, arg))
8356 /* Make sure that ARG is not a variable-sized array. (Note that
8357 were talking about variable-sized arrays (like `int[n]'),
8358 rather than arrays of unknown size (like `int[]').) We'll
8359 get very confused by such a type since the bound of the array
8360 will not be computable in an instantiation. Besides, such
8361 types are not allowed in ISO C++, so we can do as we please
8363 if (TREE_CODE (arg) == ARRAY_TYPE
8364 && !uses_template_parms (arg)
8365 && (TREE_CODE (TYPE_MAX_VALUE (TYPE_DOMAIN (arg)))
8369 TREE_VEC_ELT (targs, idx) = arg;
8372 case TEMPLATE_PARM_INDEX:
8373 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
8375 if (TEMPLATE_PARM_LEVEL (parm)
8376 != template_decl_level (tparm))
8377 /* The PARM is not one we're trying to unify. Just check
8378 to see if it matches ARG. */
8379 return (TREE_CODE (arg) == TREE_CODE (parm)
8380 && cp_tree_equal (parm, arg) > 0) ? 0 : 1;
8382 idx = TEMPLATE_PARM_IDX (parm);
8383 targ = TREE_VEC_ELT (targs, idx);
8387 int i = (cp_tree_equal (targ, arg) > 0);
8393 my_friendly_abort (42);
8396 /* [temp.deduct.type] If, in the declaration of a function template
8397 with a non-type template-parameter, the non-type
8398 template-parameter is used in an expression in the function
8399 parameter-list and, if the corresponding template-argument is
8400 deduced, the template-argument type shall match the type of the
8401 template-parameter exactly, except that a template-argument
8402 deduced from an array bound may be of any integral type. */
8403 if (same_type_p (TREE_TYPE (arg), TREE_TYPE (parm)))
8405 else if ((strict & UNIFY_ALLOW_INTEGER)
8406 && (TREE_CODE (TREE_TYPE (parm)) == INTEGER_TYPE
8407 || TREE_CODE (TREE_TYPE (parm)) == BOOLEAN_TYPE))
8412 TREE_VEC_ELT (targs, idx) = arg;
8419 if (TREE_CODE (arg) != POINTER_TYPE)
8422 /* [temp.deduct.call]
8424 A can be another pointer or pointer to member type that can
8425 be converted to the deduced A via a qualification
8426 conversion (_conv.qual_).
8428 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
8429 This will allow for additional cv-qualification of the
8430 pointed-to types if appropriate. In general, this is a bit
8431 too generous; we are only supposed to allow qualification
8432 conversions and this method will allow an ARG of char** and
8433 a deduced ARG of const char**. However, overload
8434 resolution will subsequently invalidate the candidate, so
8435 this is probably OK. */
8436 sub_strict = strict;
8438 if (TREE_CODE (TREE_TYPE (arg)) != RECORD_TYPE)
8439 /* The derived-to-base conversion only persists through one
8440 level of pointers. */
8441 sub_strict &= ~UNIFY_ALLOW_DERIVED;
8443 return unify (tparms, targs, TREE_TYPE (parm),
8444 TREE_TYPE (arg), sub_strict);
8447 case REFERENCE_TYPE:
8448 if (TREE_CODE (arg) != REFERENCE_TYPE)
8450 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
8454 if (TREE_CODE (arg) != ARRAY_TYPE)
8456 if ((TYPE_DOMAIN (parm) == NULL_TREE)
8457 != (TYPE_DOMAIN (arg) == NULL_TREE))
8459 if (TYPE_DOMAIN (parm) != NULL_TREE
8460 && unify (tparms, targs, TYPE_DOMAIN (parm),
8461 TYPE_DOMAIN (arg), UNIFY_ALLOW_NONE) != 0)
8463 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
8471 if (TREE_CODE (arg) != TREE_CODE (parm))
8474 if (TREE_CODE (parm) == INTEGER_TYPE
8475 && TREE_CODE (TYPE_MAX_VALUE (parm)) != INTEGER_CST)
8477 if (TYPE_MIN_VALUE (parm) && TYPE_MIN_VALUE (arg)
8478 && unify (tparms, targs, TYPE_MIN_VALUE (parm),
8479 TYPE_MIN_VALUE (arg), UNIFY_ALLOW_INTEGER))
8481 if (TYPE_MAX_VALUE (parm) && TYPE_MAX_VALUE (arg)
8482 && unify (tparms, targs, TYPE_MAX_VALUE (parm),
8483 TYPE_MAX_VALUE (arg), UNIFY_ALLOW_INTEGER))
8486 /* We use the TYPE_MAIN_VARIANT since we have already
8487 checked cv-qualification at the top of the
8489 else if (!same_type_p (TYPE_MAIN_VARIANT (arg),
8490 TYPE_MAIN_VARIANT (parm)))
8493 /* As far as unification is concerned, this wins. Later checks
8494 will invalidate it if necessary. */
8497 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
8498 /* Type INTEGER_CST can come from ordinary constant template args. */
8500 while (TREE_CODE (arg) == NOP_EXPR)
8501 arg = TREE_OPERAND (arg, 0);
8503 if (TREE_CODE (arg) != INTEGER_CST)
8505 return !tree_int_cst_equal (parm, arg);
8510 if (TREE_CODE (arg) != TREE_VEC)
8512 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
8514 for (i = TREE_VEC_LENGTH (parm) - 1; i >= 0; i--)
8515 if (unify (tparms, targs,
8516 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
8524 if (TREE_CODE (arg) != TREE_CODE (parm))
8527 if (TYPE_PTRMEMFUNC_P (parm))
8529 if (!TYPE_PTRMEMFUNC_P (arg))
8532 return unify (tparms, targs,
8533 TYPE_PTRMEMFUNC_FN_TYPE (parm),
8534 TYPE_PTRMEMFUNC_FN_TYPE (arg),
8538 if (CLASSTYPE_TEMPLATE_INFO (parm))
8542 if (strict & UNIFY_ALLOW_DERIVED)
8544 /* First, we try to unify the PARM and ARG directly. */
8545 t = try_class_unification (tparms, targs,
8550 /* Fallback to the special case allowed in
8553 If P is a class, and P has the form
8554 template-id, then A can be a derived class of
8555 the deduced A. Likewise, if P is a pointer to
8556 a class of the form template-id, A can be a
8557 pointer to a derived class pointed to by the
8559 t = get_template_base (tparms, targs,
8562 if (! t || t == error_mark_node)
8566 else if (CLASSTYPE_TEMPLATE_INFO (arg)
8567 && (CLASSTYPE_TI_TEMPLATE (parm)
8568 == CLASSTYPE_TI_TEMPLATE (arg)))
8569 /* Perhaps PARM is something like S<U> and ARG is S<int>.
8570 Then, we should unify `int' and `U'. */
8573 /* There's no chance of unication succeeding. */
8576 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
8577 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
8579 else if (!same_type_p (TYPE_MAIN_VARIANT (parm),
8580 TYPE_MAIN_VARIANT (arg)))
8586 if (TREE_CODE (arg) != TREE_CODE (parm))
8589 if (unify (tparms, targs, TREE_TYPE (parm),
8590 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
8592 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
8593 TYPE_ARG_TYPES (arg), 1,
8597 if (TREE_CODE (arg) != OFFSET_TYPE)
8599 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
8600 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
8602 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
8606 if (arg != decl_constant_value (parm))
8611 /* Matched cases are handled by the ARG == PARM test above. */
8615 if (TREE_CODE (TREE_OPERAND (parm, 1)) == INTEGER_CST)
8617 /* We handle this case specially, since it comes up with
8618 arrays. In particular, something like:
8620 template <int N> void f(int (&x)[N]);
8622 Here, we are trying to unify the range type, which
8623 looks like [0 ... (N - 1)]. */
8625 t1 = TREE_OPERAND (parm, 0);
8626 t2 = TREE_OPERAND (parm, 1);
8628 t = fold (build (PLUS_EXPR, integer_type_node, arg, t2));
8630 return unify (tparms, targs, t1, t, strict);
8632 /* else fall through */
8635 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (parm))))
8636 /* We're looking at an expression. This can happen with
8640 void foo(S<I>, S<I + 2>);
8642 This is a "nondeduced context":
8646 The nondeduced contexts are:
8648 --A type that is a template-id in which one or more of
8649 the template-arguments is an expression that references
8650 a template-parameter.
8652 In these cases, we assume deduction succeeded, but don't
8653 actually infer any unifications. */
8656 sorry ("use of `%s' in template type unification",
8657 tree_code_name [(int) TREE_CODE (parm)]);
8663 /* Called if RESULT is explicitly instantiated, or is a member of an
8664 explicitly instantiated class, or if using -frepo and the
8665 instantiation of RESULT has been assigned to this file. */
8668 mark_decl_instantiated (result, extern_p)
8672 if (TREE_CODE (result) != FUNCTION_DECL)
8673 /* The TREE_PUBLIC flag for function declarations will have been
8674 set correctly by tsubst. */
8675 TREE_PUBLIC (result) = 1;
8679 DECL_INTERFACE_KNOWN (result) = 1;
8680 DECL_NOT_REALLY_EXTERN (result) = 1;
8682 /* Always make artificials weak. */
8683 if (DECL_ARTIFICIAL (result) && flag_weak)
8684 comdat_linkage (result);
8685 /* For WIN32 we also want to put explicit instantiations in
8686 linkonce sections. */
8687 else if (TREE_PUBLIC (result))
8688 maybe_make_one_only (result);
8690 else if (TREE_CODE (result) == FUNCTION_DECL)
8691 mark_inline_for_output (result);
8694 /* Given two function templates PAT1 and PAT2, and explicit template
8695 arguments EXPLICIT_ARGS return:
8697 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
8698 -1 if PAT2 is more specialized than PAT1.
8699 0 if neither is more specialized. */
8702 more_specialized (pat1, pat2, explicit_args)
8703 tree pat1, pat2, explicit_args;
8709 = get_bindings_overload (pat1, DECL_TEMPLATE_RESULT (pat2), explicit_args);
8714 = get_bindings_overload (pat2, DECL_TEMPLATE_RESULT (pat1), explicit_args);
8721 /* Given two class template specialization list nodes PAT1 and PAT2, return:
8723 1 if PAT1 is more specialized than PAT2 as described in [temp.class.order].
8724 -1 if PAT2 is more specialized than PAT1.
8725 0 if neither is more specialized. */
8728 more_specialized_class (pat1, pat2)
8734 targs = get_class_bindings (TREE_VALUE (pat1), TREE_PURPOSE (pat1),
8735 TREE_PURPOSE (pat2));
8739 targs = get_class_bindings (TREE_VALUE (pat2), TREE_PURPOSE (pat2),
8740 TREE_PURPOSE (pat1));
8747 /* Return the template arguments that will produce the function signature
8748 DECL from the function template FN, with the explicit template
8749 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is 1, the return type must
8750 also match. Return NULL_TREE if no satisfactory arguments could be
8754 get_bindings_real (fn, decl, explicit_args, check_rettype)
8755 tree fn, decl, explicit_args;
8758 int ntparms = DECL_NTPARMS (fn);
8759 tree targs = make_tree_vec (ntparms);
8761 tree decl_arg_types;
8764 /* Substitute the explicit template arguments into the type of DECL.
8765 The call to fn_type_unification will handle substitution into the
8767 decl_type = TREE_TYPE (decl);
8768 if (explicit_args && uses_template_parms (decl_type))
8771 tree converted_args;
8773 if (DECL_TEMPLATE_INFO (decl))
8774 tmpl = DECL_TI_TEMPLATE (decl);
8776 /* We can get here for some illegal specializations. */
8780 = (coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
8781 explicit_args, NULL_TREE,
8783 /*require_all_arguments=*/0));
8784 if (converted_args == error_mark_node)
8787 decl_type = tsubst (decl_type, converted_args, /*complain=*/0,
8789 if (decl_type == error_mark_node)
8793 /* If FN is a static member function, adjust the type of DECL
8795 decl_arg_types = TYPE_ARG_TYPES (decl_type);
8796 if (DECL_STATIC_FUNCTION_P (fn)
8797 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
8798 decl_arg_types = TREE_CHAIN (decl_arg_types);
8800 i = fn_type_unification (fn, explicit_args, targs,
8802 (check_rettype || DECL_CONV_FN_P (fn)
8803 ? TREE_TYPE (decl_type) : NULL_TREE),
8812 /* For most uses, we want to check the return type. */
8815 get_bindings (fn, decl, explicit_args)
8816 tree fn, decl, explicit_args;
8818 return get_bindings_real (fn, decl, explicit_args, 1);
8821 /* But for more_specialized, we only care about the parameter types. */
8824 get_bindings_overload (fn, decl, explicit_args)
8825 tree fn, decl, explicit_args;
8827 return get_bindings_real (fn, decl, explicit_args, 0);
8830 /* Return the innermost template arguments that, when applied to a
8831 template specialization whose innermost template parameters are
8832 TPARMS, and whose specialization arguments are ARGS, yield the
8835 For example, suppose we have:
8837 template <class T, class U> struct S {};
8838 template <class T> struct S<T*, int> {};
8840 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
8841 {T}, the PARMS will be {T*, int} and the ARGS will be {double*,
8842 int}. The resulting vector will be {double}, indicating that `T'
8843 is bound to `double'. */
8846 get_class_bindings (tparms, parms, args)
8847 tree tparms, parms, args;
8849 int i, ntparms = TREE_VEC_LENGTH (tparms);
8850 tree vec = make_tree_vec (ntparms);
8852 args = innermost_args (args);
8854 if (unify (tparms, vec, parms, args, UNIFY_ALLOW_NONE))
8857 for (i = 0; i < ntparms; ++i)
8858 if (! TREE_VEC_ELT (vec, i))
8864 /* In INSTANTIATIONS is a list of <INSTANTIATION, TEMPLATE> pairs.
8865 Pick the most specialized template, and return the corresponding
8866 instantiation, or if there is no corresponding instantiation, the
8867 template itself. EXPLICIT_ARGS is any template arguments explicity
8868 mentioned in a template-id. If there is no most specialized
8869 tempalte, error_mark_node is returned. If there are no templates
8870 at all, NULL_TREE is returned. */
8873 most_specialized_instantiation (instantiations, explicit_args)
8874 tree instantiations;
8880 if (!instantiations)
8883 champ = instantiations;
8884 for (fn = TREE_CHAIN (instantiations); fn; fn = TREE_CHAIN (fn))
8886 fate = more_specialized (TREE_VALUE (champ),
8887 TREE_VALUE (fn), explicit_args);
8894 fn = TREE_CHAIN (fn);
8896 return error_mark_node;
8902 for (fn = instantiations; fn && fn != champ; fn = TREE_CHAIN (fn))
8904 fate = more_specialized (TREE_VALUE (champ),
8905 TREE_VALUE (fn), explicit_args);
8907 return error_mark_node;
8910 return TREE_PURPOSE (champ) ? TREE_PURPOSE (champ) : TREE_VALUE (champ);
8913 /* Return the most specialized of the list of templates in FNS that can
8914 produce an instantiation matching DECL, given the explicit template
8915 arguments EXPLICIT_ARGS. */
8918 most_specialized (fns, decl, explicit_args)
8919 tree fns, decl, explicit_args;
8921 tree candidates = NULL_TREE;
8924 for (fn = fns; fn; fn = TREE_CHAIN (fn))
8926 tree candidate = TREE_VALUE (fn);
8928 args = get_bindings (candidate, decl, explicit_args);
8930 candidates = tree_cons (NULL_TREE, candidate, candidates);
8933 return most_specialized_instantiation (candidates, explicit_args);
8936 /* If DECL is a specialization of some template, return the most
8937 general such template. For example, given:
8939 template <class T> struct S { template <class U> void f(U); };
8941 if TMPL is `template <class U> void S<int>::f(U)' this will return
8942 the full template. This function will not trace past partial
8943 specializations, however. For example, given in addition:
8945 template <class T> struct S<T*> { template <class U> void f(U); };
8947 if TMPL is `template <class U> void S<int*>::f(U)' this will return
8948 `template <class T> template <class U> S<T*>::f(U)'. */
8951 most_general_template (decl)
8954 while (DECL_TEMPLATE_INFO (decl)
8955 && !(TREE_CODE (decl) == TEMPLATE_DECL
8956 && DECL_TEMPLATE_SPECIALIZATION (decl))
8957 /* The DECL_TI_TEMPLATE can be a LOOKUP_EXPR or
8958 IDENTIFIER_NODE in some cases. (See cp-tree.h for
8960 && TREE_CODE (DECL_TI_TEMPLATE (decl)) == TEMPLATE_DECL)
8961 decl = DECL_TI_TEMPLATE (decl);
8966 /* Return the most specialized of the class template specializations
8967 of TMPL which can produce an instantiation matching ARGS, or
8968 error_mark_node if the choice is ambiguous. */
8971 most_specialized_class (tmpl, args)
8975 tree list = NULL_TREE;
8980 tmpl = most_general_template (tmpl);
8981 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
8984 = get_class_bindings (TREE_VALUE (t), TREE_PURPOSE (t), args);
8987 list = decl_tree_cons (TREE_PURPOSE (t), TREE_VALUE (t), list);
8988 TREE_TYPE (list) = TREE_TYPE (t);
8998 for (; t; t = TREE_CHAIN (t))
9000 fate = more_specialized_class (champ, t);
9009 return error_mark_node;
9015 for (t = list; t && t != champ; t = TREE_CHAIN (t))
9017 fate = more_specialized_class (champ, t);
9019 return error_mark_node;
9025 /* called from the parser. */
9028 do_decl_instantiation (declspecs, declarator, storage)
9029 tree declspecs, declarator, storage;
9031 tree decl = grokdeclarator (declarator, declspecs, NORMAL, 0, NULL_TREE);
9032 tree result = NULL_TREE;
9036 /* An error ocurred, for which grokdeclarator has already issued
9037 an appropriate message. */
9039 else if (! DECL_LANG_SPECIFIC (decl))
9041 cp_error ("explicit instantiation of non-template `%#D'", decl);
9044 else if (TREE_CODE (decl) == VAR_DECL)
9046 /* There is an asymmetry here in the way VAR_DECLs and
9047 FUNCTION_DECLs are handled by grokdeclarator. In the case of
9048 the latter, the DECL we get back will be marked as a
9049 template instantiation, and the appropriate
9050 DECL_TEMPLATE_INFO will be set up. This does not happen for
9051 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
9052 should handle VAR_DECLs as it currently handles
9054 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, 0);
9055 if (result && TREE_CODE (result) != VAR_DECL)
9057 cp_error ("no matching template for `%D' found", result);
9061 else if (TREE_CODE (decl) != FUNCTION_DECL)
9063 cp_error ("explicit instantiation of `%#D'", decl);
9069 /* Check for various error cases. Note that if the explicit
9070 instantiation is legal the RESULT will currently be marked as an
9071 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
9072 until we get here. */
9074 if (DECL_TEMPLATE_SPECIALIZATION (result))
9078 No program shall both explicitly instantiate and explicitly
9079 specialize a template. */
9080 cp_pedwarn ("explicit instantiation of `%#D' after", result);
9081 cp_pedwarn_at ("explicit specialization here", result);
9084 else if (DECL_EXPLICIT_INSTANTIATION (result))
9088 No program shall explicitly instantiate any template more
9091 We check DECL_INTERFACE_KNOWN so as not to complain when the first
9092 instantiation was `extern' and the second is not, and EXTERN_P for
9093 the opposite case. If -frepo, chances are we already got marked
9094 as an explicit instantion because of the repo file. */
9095 if (DECL_INTERFACE_KNOWN (result) && !extern_p && !flag_use_repository)
9096 cp_pedwarn ("duplicate explicit instantiation of `%#D'", result);
9098 /* If we've already instantiated the template, just return now. */
9099 if (DECL_INTERFACE_KNOWN (result))
9102 else if (!DECL_IMPLICIT_INSTANTIATION (result))
9104 cp_error ("no matching template for `%D' found", result);
9107 else if (!DECL_TEMPLATE_INFO (result))
9109 cp_pedwarn ("explicit instantiation of non-template `%#D'", result);
9113 if (flag_external_templates)
9116 if (storage == NULL_TREE)
9118 else if (storage == ridpointers[(int) RID_EXTERN])
9121 cp_pedwarn ("ISO C++ forbids the use of `extern' on explicit instantiations");
9125 cp_error ("storage class `%D' applied to template instantiation",
9128 SET_DECL_EXPLICIT_INSTANTIATION (result);
9129 mark_decl_instantiated (result, extern_p);
9130 repo_template_instantiated (result, extern_p);
9132 instantiate_decl (result);
9136 mark_class_instantiated (t, extern_p)
9140 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
9141 SET_CLASSTYPE_INTERFACE_KNOWN (t);
9142 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
9143 CLASSTYPE_VTABLE_NEEDS_WRITING (t) = ! extern_p;
9144 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
9147 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
9148 rest_of_type_compilation (t, 1);
9153 do_type_instantiation (t, storage)
9160 if (TREE_CODE (t) == TYPE_DECL)
9163 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
9165 cp_error ("explicit instantiation of non-template type `%T'", t);
9171 /* With -fexternal-templates, explicit instantiations are treated the same
9172 as implicit ones. */
9173 if (flag_external_templates)
9176 if (!COMPLETE_TYPE_P (t))
9178 cp_error ("explicit instantiation of `%#T' before definition of template",
9183 if (storage != NULL_TREE)
9186 cp_pedwarn("ISO C++ forbids the use of `%s' on explicit instantiations",
9187 IDENTIFIER_POINTER (storage));
9189 if (storage == ridpointers[(int) RID_INLINE])
9191 else if (storage == ridpointers[(int) RID_EXTERN])
9193 else if (storage == ridpointers[(int) RID_STATIC])
9197 cp_error ("storage class `%D' applied to template instantiation",
9203 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
9207 No program shall both explicitly instantiate and explicitly
9208 specialize a template. */
9209 cp_error ("explicit instantiation of `%#T' after", t);
9210 cp_error_at ("explicit specialization here", t);
9213 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
9217 No program shall explicitly instantiate any template more
9220 If CLASSTYPE_INTERFACE_ONLY, then the first explicit instantiation
9221 was `extern'. If EXTERN_P then the second is. If -frepo, chances
9222 are we already got marked as an explicit instantion because of the
9223 repo file. All these cases are OK. */
9224 if (!CLASSTYPE_INTERFACE_ONLY (t) && !extern_p && !flag_use_repository)
9225 cp_pedwarn ("duplicate explicit instantiation of `%#T'", t);
9227 /* If we've already instantiated the template, just return now. */
9228 if (!CLASSTYPE_INTERFACE_ONLY (t))
9232 mark_class_instantiated (t, extern_p);
9233 repo_template_instantiated (t, extern_p);
9241 /* In contrast to implicit instantiation, where only the
9242 declarations, and not the definitions, of members are
9243 instantiated, we have here:
9247 The explicit instantiation of a class template specialization
9248 implies the instantiation of all of its members not
9249 previously explicitly specialized in the translation unit
9250 containing the explicit instantiation.
9252 Of course, we can't instantiate member template classes, since
9253 we don't have any arguments for them. Note that the standard
9254 is unclear on whether the instatiation of the members are
9255 *explicit* instantiations or not. We choose to be generous,
9256 and not set DECL_EXPLICIT_INSTANTIATION. Therefore, we allow
9257 the explicit instantiation of a class where some of the members
9258 have no definition in the current translation unit. */
9261 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
9262 if (TREE_CODE (tmp) == FUNCTION_DECL
9263 && DECL_TEMPLATE_INSTANTIATION (tmp))
9265 mark_decl_instantiated (tmp, extern_p);
9266 repo_template_instantiated (tmp, extern_p);
9268 instantiate_decl (tmp);
9271 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
9272 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
9274 mark_decl_instantiated (tmp, extern_p);
9275 repo_template_instantiated (tmp, extern_p);
9277 instantiate_decl (tmp);
9280 for (tmp = CLASSTYPE_TAGS (t); tmp; tmp = TREE_CHAIN (tmp))
9281 if (IS_AGGR_TYPE (TREE_VALUE (tmp))
9282 && !uses_template_parms (CLASSTYPE_TI_ARGS (TREE_VALUE (tmp))))
9283 do_type_instantiation (TYPE_MAIN_DECL (TREE_VALUE (tmp)), storage);
9287 /* Given a function DECL, which is a specialization of TMPL, modify
9288 DECL to be a re-instantiation of TMPL with the same template
9289 arguments. TMPL should be the template into which tsubst'ing
9290 should occur for DECL, not the most general template.
9292 One reason for doing this is a scenario like this:
9295 void f(const T&, int i);
9297 void g() { f(3, 7); }
9300 void f(const T& t, const int i) { }
9302 Note that when the template is first instantiated, with
9303 instantiate_template, the resulting DECL will have no name for the
9304 first parameter, and the wrong type for the second. So, when we go
9305 to instantiate the DECL, we regenerate it. */
9308 regenerate_decl_from_template (decl, tmpl)
9318 args = DECL_TI_ARGS (decl);
9319 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
9321 /* Unregister the specialization so that when we tsubst we will not
9322 just return DECL. We don't have to unregister DECL from TMPL
9323 because if would only be registered there if it were a partial
9324 instantiation of a specialization, which it isn't: it's a full
9326 gen_tmpl = most_general_template (tmpl);
9327 unregistered = unregister_specialization (decl, gen_tmpl);
9329 /* If the DECL was not unregistered then something peculiar is
9330 happening: we created a specialization but did not call
9331 register_specialization for it. */
9332 my_friendly_assert (unregistered, 0);
9334 if (TREE_CODE (decl) == VAR_DECL)
9335 /* Make sure that we can see identifiers, and compute access
9336 correctly, for the class members used in the declaration of
9337 this static variable. */
9338 pushclass (DECL_CONTEXT (decl), 2);
9340 /* Do the substitution to get the new declaration. */
9341 new_decl = tsubst (code_pattern, args, /*complain=*/1, NULL_TREE);
9343 if (TREE_CODE (decl) == VAR_DECL)
9345 /* Set up DECL_INITIAL, since tsubst doesn't. */
9346 DECL_INITIAL (new_decl) =
9347 tsubst_expr (DECL_INITIAL (code_pattern), args,
9348 /*complain=*/1, DECL_TI_TEMPLATE (decl));
9349 /* Pop the class context we pushed above. */
9352 else if (TREE_CODE (decl) == FUNCTION_DECL)
9354 /* Convince duplicate_decls to use the DECL_ARGUMENTS from the
9356 DECL_INITIAL (new_decl) = error_mark_node;
9357 /* And don't complain about a duplicate definition. */
9358 DECL_INITIAL (decl) = NULL_TREE;
9361 /* The immediate parent of the new template is still whatever it was
9362 before, even though tsubst sets DECL_TI_TEMPLATE up as the most
9363 general template. We also reset the DECL_ASSEMBLER_NAME since
9364 tsubst always calculates the name as if the function in question
9365 were really a template instance, and sometimes, with friend
9366 functions, this is not so. See tsubst_friend_function for
9368 DECL_TI_TEMPLATE (new_decl) = DECL_TI_TEMPLATE (decl);
9369 DECL_ASSEMBLER_NAME (new_decl) = DECL_ASSEMBLER_NAME (decl);
9370 DECL_RTL (new_decl) = DECL_RTL (decl);
9372 /* Call duplicate decls to merge the old and new declarations. */
9373 duplicate_decls (new_decl, decl);
9375 /* Now, re-register the specialization. */
9376 register_specialization (decl, gen_tmpl, args);
9379 /* Produce the definition of D, a _DECL generated from a template. */
9382 instantiate_decl (d)
9385 tree tmpl = DECL_TI_TEMPLATE (d);
9386 tree args = DECL_TI_ARGS (d);
9391 int nested = in_function_p ();
9392 int pattern_defined;
9394 char *file = input_filename;
9395 tree old_fn = current_function_decl;
9397 /* This function should only be used to instantiate templates for
9398 functions and static member variables. */
9399 my_friendly_assert (TREE_CODE (d) == FUNCTION_DECL
9400 || TREE_CODE (d) == VAR_DECL, 0);
9402 if (DECL_TEMPLATE_INSTANTIATED (d))
9403 /* D has already been instantiated. It might seem reasonable to
9404 check whether or not D is an explict instantiation, and, if so,
9405 stop here. But when an explicit instantiation is deferred
9406 until the end of the compilation, DECL_EXPLICIT_INSTANTIATION
9407 is set, even though we still need to do the instantiation. */
9410 /* If we already have a specialization of this declaration, then
9411 there's no reason to instantiate it. Note that
9412 retrieve_specialization gives us both instantiations and
9413 specializations, so we must explicitly check
9414 DECL_TEMPLATE_SPECIALIZATION. */
9415 gen_tmpl = most_general_template (tmpl);
9416 spec = retrieve_specialization (gen_tmpl, args);
9417 if (spec != NULL_TREE && DECL_TEMPLATE_SPECIALIZATION (spec))
9420 /* This needs to happen before any tsubsting. */
9421 if (! push_tinst_level (d))
9424 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
9425 for the instantiation. This is not always the most general
9426 template. Consider, for example:
9429 struct S { template <class U> void f();
9430 template <> void f<int>(); };
9432 and an instantiation of S<double>::f<int>. We want TD to be the
9433 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
9436 /* An instantiation cannot have a definition, so we need a
9437 more general template. */
9438 DECL_TEMPLATE_INSTANTIATION (td)
9439 /* We must also deal with friend templates. Given:
9441 template <class T> struct S {
9442 template <class U> friend void f() {};
9445 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
9446 so far as the language is concerned, but that's still
9447 where we get the pattern for the instantiation from. On
9448 ther hand, if the definition comes outside the class, say:
9450 template <class T> struct S {
9451 template <class U> friend void f();
9453 template <class U> friend void f() {}
9455 we don't need to look any further. That's what the check for
9456 DECL_INITIAL is for. */
9457 || (TREE_CODE (d) == FUNCTION_DECL
9458 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (td)
9459 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (td)));
9462 /* The present template, TD, should not be a definition. If it
9463 were a definition, we should be using it! Note that we
9464 cannot restructure the loop to just keep going until we find
9465 a template with a definition, since that might go too far if
9466 a specialization was declared, but not defined. */
9467 my_friendly_assert (!(TREE_CODE (d) == VAR_DECL
9468 && !DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (td))),
9471 /* Fetch the more general template. */
9472 td = DECL_TI_TEMPLATE (td);
9475 code_pattern = DECL_TEMPLATE_RESULT (td);
9477 if (TREE_CODE (d) == FUNCTION_DECL)
9478 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
9480 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
9482 push_to_top_level ();
9483 lineno = DECL_SOURCE_LINE (d);
9484 input_filename = DECL_SOURCE_FILE (d);
9486 if (pattern_defined)
9488 repo_template_used (d);
9490 if (flag_external_templates && ! DECL_INTERFACE_KNOWN (d))
9492 if (flag_alt_external_templates)
9494 if (interface_unknown)
9495 warn_if_unknown_interface (d);
9497 else if (DECL_INTERFACE_KNOWN (code_pattern))
9499 DECL_INTERFACE_KNOWN (d) = 1;
9500 DECL_NOT_REALLY_EXTERN (d) = ! DECL_EXTERNAL (code_pattern);
9503 warn_if_unknown_interface (code_pattern);
9507 import_export_decl (d);
9510 /* Reject all external templates except inline functions. */
9511 if (DECL_INTERFACE_KNOWN (d)
9512 && ! DECL_NOT_REALLY_EXTERN (d)
9513 && ! (TREE_CODE (d) == FUNCTION_DECL && DECL_INLINE (d)))
9516 if (TREE_CODE (d) == VAR_DECL
9517 && TREE_READONLY (d)
9518 && DECL_INITIAL (d) == NULL_TREE
9519 && DECL_INITIAL (code_pattern) != NULL_TREE)
9520 /* We need to set up DECL_INITIAL regardless of pattern_defined if
9521 the variable is a static const initialized in the class body. */;
9522 else if (pattern_defined && nested
9523 && TREE_CODE (d) == FUNCTION_DECL && DECL_INLINE (d))
9524 /* An inline function used in another function; instantiate it now so
9525 we can inline it. */;
9526 else if (! pattern_defined || ! at_eof)
9528 /* Defer all other templates. We restore the source position
9529 here because it's used by add_pending_template. */
9531 input_filename = file;
9533 if (at_eof && !pattern_defined
9534 && DECL_EXPLICIT_INSTANTIATION (d))
9537 The definition of a non-exported function template, a
9538 non-exported member function template, or a non-exported
9539 member function or static data member of a class template
9540 shall be present in every translation unit in which it is
9541 explicitly instantiated. */
9542 cp_error ("explicit instantiation of `%D' but no definition available",
9545 add_pending_template (d);
9549 /* If this instantiation is COMDAT, we don't know whether or not we
9550 will really need to write it out. If we can't be sure, mark it
9551 DECL_DEFER_OUTPUT. NOTE: This increases memory consumption,
9552 since we keep some instantiations in memory rather than write
9553 them out immediately and forget them. A better approach would be
9554 to wait until we know we need them to do the instantiation, but
9555 that would break templates with static locals, because we
9556 generate the functions to destroy statics before we determine
9557 which functions are needed. A better solution would be to
9558 generate the ctor and dtor functions as we go. */
9560 if (TREE_CODE (d) == FUNCTION_DECL
9562 && ! DECL_NEEDED_P (d)
9563 /* If the function that caused us to be instantiated is needed, we
9564 will be needed, too. */
9565 && (! nested || (old_fn && ! DECL_NEEDED_P (old_fn))))
9566 DECL_DEFER_OUTPUT (d) = 1;
9568 /* We're now committed to instantiating this template. Mark it as
9569 instantiated so that recursive calls to instantiate_decl do not
9570 try to instantiate it again. */
9571 DECL_TEMPLATE_INSTANTIATED (d) = 1;
9573 /* Regenerate the declaration in case the template has been modified
9574 by a subsequent redeclaration. */
9575 regenerate_decl_from_template (d, td);
9577 /* We already set the file and line above. Reset them now in case
9578 they changed as a result of calling regenerate_decl_from_template. */
9579 lineno = DECL_SOURCE_LINE (d);
9580 input_filename = DECL_SOURCE_FILE (d);
9582 if (TREE_CODE (d) == VAR_DECL)
9584 DECL_IN_AGGR_P (d) = 0;
9585 if (DECL_INTERFACE_KNOWN (d))
9586 DECL_EXTERNAL (d) = ! DECL_NOT_REALLY_EXTERN (d);
9589 DECL_EXTERNAL (d) = 1;
9590 DECL_NOT_REALLY_EXTERN (d) = 1;
9592 cp_finish_decl (d, DECL_INITIAL (d), NULL_TREE, 0);
9594 else if (TREE_CODE (d) == FUNCTION_DECL)
9596 /* Set up context. */
9597 start_function (NULL_TREE, d, NULL_TREE, SF_PRE_PARSED);
9598 store_parm_decls ();
9600 /* We already set up __FUNCTION__, etc., so we don't want to do
9602 current_function_name_declared = 1;
9604 /* Substitute into the body of the function. */
9605 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
9606 /*complain=*/1, tmpl);
9608 /* Finish the function. */
9609 expand_body (finish_function (lineno, 0));
9612 /* We're not deferring instantiation any more. */
9613 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
9617 input_filename = file;
9619 pop_from_top_level ();
9625 /* Run through the list of templates that we wish we could
9626 instantiate, and instantiate any we can. */
9629 instantiate_pending_templates ()
9632 int instantiated_something = 0;
9639 t = &pending_templates;
9642 tree srcloc = TREE_PURPOSE (*t);
9643 tree instantiation = TREE_VALUE (*t);
9645 input_filename = SRCLOC_FILE (srcloc);
9646 lineno = SRCLOC_LINE (srcloc);
9648 if (TYPE_P (instantiation))
9652 if (!COMPLETE_TYPE_P (instantiation))
9654 instantiate_class_template (instantiation);
9655 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
9656 for (fn = TYPE_METHODS (instantiation);
9658 fn = TREE_CHAIN (fn))
9659 if (! DECL_ARTIFICIAL (fn))
9660 instantiate_decl (fn);
9661 if (COMPLETE_TYPE_P (instantiation))
9663 instantiated_something = 1;
9668 if (COMPLETE_TYPE_P (instantiation))
9669 /* If INSTANTIATION has been instantiated, then we don't
9670 need to consider it again in the future. */
9671 *t = TREE_CHAIN (*t);
9673 t = &TREE_CHAIN (*t);
9677 if (DECL_TEMPLATE_INSTANTIATION (instantiation)
9678 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
9680 instantiation = instantiate_decl (instantiation);
9681 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
9683 instantiated_something = 1;
9688 if (!DECL_TEMPLATE_INSTANTIATION (instantiation)
9689 || DECL_TEMPLATE_INSTANTIATED (instantiation))
9690 /* If INSTANTIATION has been instantiated, then we don't
9691 need to consider it again in the future. */
9692 *t = TREE_CHAIN (*t);
9694 t = &TREE_CHAIN (*t);
9699 /* Go through the things that are template instantiations if we are
9700 using guiding declarations. */
9701 t = &maybe_templates;
9708 fn = TREE_VALUE (*t);
9710 if (DECL_INITIAL (fn))
9711 /* If the FN is already defined, then it was either already
9712 instantiated or, even though guiding declarations were
9713 allowed, a non-template definition was provided. */
9717 template = TREE_PURPOSE (*t);
9718 args = get_bindings (template, fn, NULL_TREE);
9719 fn = instantiate_template (template, args);
9720 instantiate_decl (fn);
9724 /* Remove this entry from the chain. */
9725 *t = TREE_CHAIN (*t);
9727 maybe_template_tail = t;
9731 return instantiated_something;
9734 /* Substitute ARGVEC into T, which is a TREE_LIST. In particular, it
9735 is an initializer list: the TREE_PURPOSEs are DECLs, and the
9736 TREE_VALUEs are initializer values. Used by instantiate_decl. */
9739 tsubst_expr_values (t, argvec)
9742 tree first = NULL_TREE;
9745 for (; t; t = TREE_CHAIN (t))
9747 tree pur = tsubst_copy (TREE_PURPOSE (t), argvec,
9748 /*complain=*/1, NULL_TREE);
9749 tree val = tsubst_expr (TREE_VALUE (t), argvec, /*complain=*/1,
9751 *p = build_tree_list (pur, val);
9752 p = &TREE_CHAIN (*p);
9757 /* D is an undefined function declaration in the presence of templates with
9758 the same name, listed in FNS. If one of them can produce D as an
9759 instantiation, remember this so we can instantiate it at EOF if D has
9760 not been defined by that time. */
9763 add_maybe_template (d, fns)
9768 if (DECL_MAYBE_TEMPLATE (d))
9771 t = most_specialized (fns, d, NULL_TREE);
9774 if (t == error_mark_node)
9776 cp_error ("ambiguous template instantiation for `%D'", d);
9780 *maybe_template_tail = tree_cons (t, d, NULL_TREE);
9781 maybe_template_tail = &TREE_CHAIN (*maybe_template_tail);
9782 DECL_MAYBE_TEMPLATE (d) = 1;
9785 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
9788 set_current_access_from_decl (decl)
9791 if (TREE_PRIVATE (decl))
9792 current_access_specifier = access_private_node;
9793 else if (TREE_PROTECTED (decl))
9794 current_access_specifier = access_protected_node;
9796 current_access_specifier = access_public_node;
9799 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
9800 is the instantiation (which should have been created with
9801 start_enum) and ARGS are the template arguments to use. */
9804 tsubst_enum (tag, newtag, args)
9811 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
9815 /* Note that in a template enum, the TREE_VALUE is the
9816 CONST_DECL, not the corresponding INTEGER_CST. */
9817 value = tsubst_expr (DECL_INITIAL (TREE_VALUE (e)),
9818 args, /*complain=*/1,
9821 /* Give this enumeration constant the correct access. */
9822 set_current_access_from_decl (TREE_VALUE (e));
9824 /* Actually build the enumerator itself. */
9825 build_enumerator (TREE_PURPOSE (e), value, newtag);
9828 finish_enum (newtag);
9831 /* Set the DECL_ASSEMBLER_NAME for DECL, which is a FUNCTION_DECL that
9832 is either an instantiation or specialization of a template
9836 set_mangled_name_for_template_decl (decl)
9839 tree saved_namespace;
9840 tree context = NULL_TREE;
9849 my_friendly_assert (TREE_CODE (decl) == FUNCTION_DECL, 0);
9850 my_friendly_assert (DECL_TEMPLATE_INFO (decl) != NULL_TREE, 0);
9852 /* The names of template functions must be mangled so as to indicate
9853 what template is being specialized with what template arguments.
9854 For example, each of the following three functions must get
9855 different mangled names:
9858 template <> void f<7>(int);
9859 template <> void f<8>(int); */
9861 targs = DECL_TI_ARGS (decl);
9862 if (uses_template_parms (targs))
9863 /* This DECL is for a partial instantiation. There's no need to
9864 mangle the name of such an entity. */
9867 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
9868 tparms = DECL_TEMPLATE_PARMS (tmpl);
9869 parm_depth = TMPL_PARMS_DEPTH (tparms);
9871 /* There should be as many levels of arguments as there are levels
9873 my_friendly_assert (parm_depth == TMPL_ARGS_DEPTH (targs), 0);
9875 /* We now compute the PARMS and RET_TYPE to give to
9876 build_decl_overload_real. The PARMS and RET_TYPE are the
9877 parameter and return types of the template, after all but the
9878 innermost template arguments have been substituted, not the
9879 parameter and return types of the function DECL. For example,
9882 template <class T> T f(T);
9884 both PARMS and RET_TYPE should be `T' even if DECL is `int f(int)'.
9885 A more subtle example is:
9887 template <class T> struct S { template <class U> void f(T, U); }
9889 Here, if DECL is `void S<int>::f(int, double)', PARMS should be
9890 {int, U}. Thus, the args that we want to subsitute into the
9891 return and parameter type for the function are those in TARGS,
9892 with the innermost level omitted. */
9893 fn_type = TREE_TYPE (tmpl);
9894 if (DECL_STATIC_FUNCTION_P (decl))
9895 context = DECL_CONTEXT (decl);
9897 if (parm_depth == 1)
9898 /* No substitution is necessary. */
9905 /* Replace the innermost level of the TARGS with NULL_TREEs to
9906 let tsubst know not to subsitute for those parameters. */
9907 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
9908 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
9909 SET_TMPL_ARGS_LEVEL (partial_args, i,
9910 TMPL_ARGS_LEVEL (targs, i));
9911 SET_TMPL_ARGS_LEVEL (partial_args,
9912 TMPL_ARGS_DEPTH (targs),
9913 make_tree_vec (DECL_NTPARMS (tmpl)));
9915 /* Now, do the (partial) substitution to figure out the
9916 appropriate function type. */
9917 fn_type = tsubst (fn_type, partial_args, /*complain=*/1, NULL_TREE);
9918 if (DECL_STATIC_FUNCTION_P (decl))
9919 context = tsubst (context, partial_args, /*complain=*/1, NULL_TREE);
9921 /* Substitute into the template parameters to obtain the real
9922 innermost set of parameters. This step is important if the
9923 innermost set of template parameters contains value
9924 parameters whose types depend on outer template parameters. */
9925 TREE_VEC_LENGTH (partial_args)--;
9926 tparms = tsubst_template_parms (tparms, partial_args, /*complain=*/1);
9929 /* Now, get the innermost parameters and arguments, and figure out
9930 the parameter and return types. */
9931 tparms = INNERMOST_TEMPLATE_PARMS (tparms);
9932 targs = innermost_args (targs);
9933 ret_type = TREE_TYPE (fn_type);
9934 parm_types = TYPE_ARG_TYPES (fn_type);
9936 /* For a static member function, we generate a fake `this' pointer,
9937 for the purposes of mangling. This indicates of which class the
9938 function is a member. Because of:
9942 There shall not be a static and a nonstatic member function
9943 with the same name and the same parameter types
9945 we don't have to worry that this will result in a clash with a
9946 non-static member function. */
9947 if (DECL_STATIC_FUNCTION_P (decl))
9948 parm_types = hash_tree_chain (build_pointer_type (context), parm_types);
9950 /* There should be the same number of template parameters as
9951 template arguments. */
9952 my_friendly_assert (TREE_VEC_LENGTH (tparms) == TREE_VEC_LENGTH (targs),
9955 /* If the template is in a namespace, we need to put that into the
9956 mangled name. Unfortunately, build_decl_overload_real does not
9957 get the decl to mangle, so it relies on the current
9958 namespace. Therefore, we set that here temporarily. */
9959 my_friendly_assert (DECL_P (decl), 980702);
9960 saved_namespace = current_namespace;
9961 current_namespace = CP_DECL_CONTEXT (decl);
9963 /* Actually set the DCL_ASSEMBLER_NAME. */
9964 DECL_ASSEMBLER_NAME (decl)
9965 = build_decl_overload_real (DECL_NAME (decl), parm_types, ret_type,
9967 DECL_FUNCTION_MEMBER_P (decl)
9968 + DECL_CONSTRUCTOR_P (decl));
9970 /* Restore the previously active namespace. */
9971 current_namespace = saved_namespace;