1 /* Breadth-first and depth-first routines for
2 searching multiple-inheritance lattice for GNU C++.
3 Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2002, 2003, 2004 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 /* High-level class interface. */
28 #include "coretypes.h"
41 /* The class dominating the hierarchy. */
43 /* A pointer to a complete object of the indicated TYPE. */
48 static tree
dfs_check_overlap (tree
, void *);
49 static tree
dfs_no_overlap_yet (tree
, int, void *);
50 static base_kind
lookup_base_r (tree
, tree
, base_access
, bool, tree
*);
51 static int dynamic_cast_base_recurse (tree
, tree
, bool, tree
*);
52 static tree
dfs_debug_unmarkedp (tree
, int, void *);
53 static tree
dfs_debug_mark (tree
, void *);
54 static tree
add_conversions (tree
, void *);
55 static int look_for_overrides_r (tree
, tree
);
56 static tree
bfs_walk (tree
, tree (*) (tree
, void *),
57 tree (*) (tree
, int, void *), void *);
58 static tree
lookup_field_queue_p (tree
, int, void *);
59 static int shared_member_p (tree
);
60 static tree
lookup_field_r (tree
, void *);
61 static tree
dfs_accessible_queue_p (tree
, int, void *);
62 static tree
dfs_accessible_p (tree
, void *);
63 static tree
dfs_access_in_type (tree
, void *);
64 static access_kind
access_in_type (tree
, tree
);
65 static int protected_accessible_p (tree
, tree
, tree
);
66 static int friend_accessible_p (tree
, tree
, tree
);
67 static int template_self_reference_p (tree
, tree
);
68 static tree
dfs_get_pure_virtuals (tree
, void *);
71 /* Variables for gathering statistics. */
72 #ifdef GATHER_STATISTICS
73 static int n_fields_searched
;
74 static int n_calls_lookup_field
, n_calls_lookup_field_1
;
75 static int n_calls_lookup_fnfields
, n_calls_lookup_fnfields_1
;
76 static int n_calls_get_base_type
;
77 static int n_outer_fields_searched
;
78 static int n_contexts_saved
;
79 #endif /* GATHER_STATISTICS */
82 /* Worker for lookup_base. BINFO is the binfo we are searching at,
83 BASE is the RECORD_TYPE we are searching for. ACCESS is the
84 required access checks. IS_VIRTUAL indicates if BINFO is morally
87 If BINFO is of the required type, then *BINFO_PTR is examined to
88 compare with any other instance of BASE we might have already
89 discovered. *BINFO_PTR is initialized and a base_kind return value
90 indicates what kind of base was located.
92 Otherwise BINFO's bases are searched. */
95 lookup_base_r (tree binfo
, tree base
, base_access access
,
96 bool is_virtual
, /* inside a virtual part */
100 tree bases
, accesses
;
101 base_kind found
= bk_not_base
;
103 if (same_type_p (BINFO_TYPE (binfo
), base
))
105 /* We have found a base. Check against what we have found
107 found
= bk_same_type
;
109 found
= bk_via_virtual
;
113 else if (binfo
!= *binfo_ptr
)
115 if (access
!= ba_any
)
117 else if (!is_virtual
)
118 /* Prefer a non-virtual base. */
126 bases
= BINFO_BASE_BINFOS (binfo
);
127 accesses
= BINFO_BASE_ACCESSES (binfo
);
131 for (i
= TREE_VEC_LENGTH (bases
); i
--;)
133 tree base_binfo
= TREE_VEC_ELT (bases
, i
);
136 bk
= lookup_base_r (base_binfo
, base
,
138 is_virtual
|| BINFO_VIRTUAL_P (base_binfo
),
144 if (access
!= ba_any
)
153 my_friendly_assert (found
== bk_not_base
, 20010723);
158 if (found
!= bk_ambig
)
172 /* Returns true if type BASE is accessible in T. (BASE is known to be
173 a (possibly non-proper) base class of T.) */
176 accessible_base_p (tree t
, tree base
)
180 /* [class.access.base]
182 A base class is said to be accessible if an invented public
183 member of the base class is accessible.
185 If BASE is a non-proper base, this condition is trivially
187 if (same_type_p (t
, base
))
189 /* Rather than inventing a public member, we use the implicit
190 public typedef created in the scope of every class. */
191 decl
= TYPE_FIELDS (base
);
192 while (!DECL_SELF_REFERENCE_P (decl
))
193 decl
= TREE_CHAIN (decl
);
194 while (ANON_AGGR_TYPE_P (t
))
195 t
= TYPE_CONTEXT (t
);
196 return accessible_p (t
, decl
);
199 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
200 ACCESS specifies. Return the binfo we discover. If KIND_PTR is
201 non-NULL, fill with information about what kind of base we
204 If the base is inaccessible, or ambiguous, and the ba_quiet bit is
205 not set in ACCESS, then an error is issued and error_mark_node is
206 returned. If the ba_quiet bit is set, then no error is issued and
207 NULL_TREE is returned. */
210 lookup_base (tree t
, tree base
, base_access access
, base_kind
*kind_ptr
)
212 tree binfo
= NULL_TREE
; /* The binfo we've found so far. */
213 tree t_binfo
= NULL_TREE
;
216 if (t
== error_mark_node
|| base
== error_mark_node
)
219 *kind_ptr
= bk_not_base
;
220 return error_mark_node
;
222 my_friendly_assert (TYPE_P (base
), 20011127);
231 t
= complete_type (TYPE_MAIN_VARIANT (t
));
232 t_binfo
= TYPE_BINFO (t
);
235 base
= complete_type (TYPE_MAIN_VARIANT (base
));
238 bk
= lookup_base_r (t_binfo
, base
, access
, 0, &binfo
);
242 /* Check that the base is unambiguous and accessible. */
243 if (access
!= ba_any
)
251 if (!(access
& ba_quiet
))
253 error ("`%T' is an ambiguous base of `%T'", base
, t
);
254 binfo
= error_mark_node
;
259 if ((access
& ~ba_quiet
) != ba_ignore
260 /* If BASE is incomplete, then BASE and TYPE are probably
261 the same, in which case BASE is accessible. If they
262 are not the same, then TYPE is invalid. In that case,
263 there's no need to issue another error here, and
264 there's no implicit typedef to use in the code that
265 follows, so we skip the check. */
266 && COMPLETE_TYPE_P (base
)
267 && !accessible_base_p (t
, base
))
269 if (!(access
& ba_quiet
))
271 error ("`%T' is an inaccessible base of `%T'", base
, t
);
272 binfo
= error_mark_node
;
276 bk
= bk_inaccessible
;
287 /* Worker function for get_dynamic_cast_base_type. */
290 dynamic_cast_base_recurse (tree subtype
, tree binfo
, bool is_via_virtual
,
293 tree binfos
, accesses
;
297 if (BINFO_TYPE (binfo
) == subtype
)
303 *offset_ptr
= BINFO_OFFSET (binfo
);
308 binfos
= BINFO_BASE_BINFOS (binfo
);
309 accesses
= BINFO_BASE_ACCESSES (binfo
);
310 n_baselinks
= binfos
? TREE_VEC_LENGTH (binfos
) : 0;
311 for (i
= 0; i
< n_baselinks
; i
++)
313 tree base_binfo
= TREE_VEC_ELT (binfos
, i
);
314 tree base_access
= TREE_VEC_ELT (accesses
, i
);
317 if (base_access
!= access_public_node
)
319 rval
= dynamic_cast_base_recurse
320 (subtype
, base_binfo
,
321 is_via_virtual
|| BINFO_VIRTUAL_P (base_binfo
), offset_ptr
);
325 worst
= worst
>= 0 ? -3 : worst
;
328 else if (rval
== -3 && worst
!= -1)
334 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
335 started from is related to the required TARGET type, in order to optimize
336 the inheritance graph search. This information is independent of the
337 current context, and ignores private paths, hence get_base_distance is
338 inappropriate. Return a TREE specifying the base offset, BOFF.
339 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
340 and there are no public virtual SUBTYPE bases.
341 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
342 BOFF == -2, SUBTYPE is not a public base.
343 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
346 get_dynamic_cast_base_type (tree subtype
, tree target
)
348 tree offset
= NULL_TREE
;
349 int boff
= dynamic_cast_base_recurse (subtype
, TYPE_BINFO (target
),
354 offset
= build_int_2 (boff
, -1);
355 TREE_TYPE (offset
) = ssizetype
;
359 /* Search for a member with name NAME in a multiple inheritance
360 lattice specified by TYPE. If it does not exist, return NULL_TREE.
361 If the member is ambiguously referenced, return `error_mark_node'.
362 Otherwise, return a DECL with the indicated name. If WANT_TYPE is
363 true, type declarations are preferred. */
365 /* Do a 1-level search for NAME as a member of TYPE. The caller must
366 figure out whether it can access this field. (Since it is only one
367 level, this is reasonable.) */
370 lookup_field_1 (tree type
, tree name
, bool want_type
)
374 if (TREE_CODE (type
) == TEMPLATE_TYPE_PARM
375 || TREE_CODE (type
) == BOUND_TEMPLATE_TEMPLATE_PARM
376 || TREE_CODE (type
) == TYPENAME_TYPE
)
377 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and
378 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all;
379 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously,
380 the code often worked even when we treated the index as a list
382 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */
386 && DECL_LANG_SPECIFIC (TYPE_NAME (type
))
387 && DECL_SORTED_FIELDS (TYPE_NAME (type
)))
389 tree
*fields
= &DECL_SORTED_FIELDS (TYPE_NAME (type
))->elts
[0];
390 int lo
= 0, hi
= DECL_SORTED_FIELDS (TYPE_NAME (type
))->len
;
397 #ifdef GATHER_STATISTICS
399 #endif /* GATHER_STATISTICS */
401 if (DECL_NAME (fields
[i
]) > name
)
403 else if (DECL_NAME (fields
[i
]) < name
)
409 /* We might have a nested class and a field with the
410 same name; we sorted them appropriately via
411 field_decl_cmp, so just look for the first or last
412 field with this name. */
417 while (i
>= lo
&& DECL_NAME (fields
[i
]) == name
);
418 if (TREE_CODE (field
) != TYPE_DECL
419 && !DECL_CLASS_TEMPLATE_P (field
))
426 while (i
< hi
&& DECL_NAME (fields
[i
]) == name
);
434 field
= TYPE_FIELDS (type
);
436 #ifdef GATHER_STATISTICS
437 n_calls_lookup_field_1
++;
438 #endif /* GATHER_STATISTICS */
439 for (field
= TYPE_FIELDS (type
); field
; field
= TREE_CHAIN (field
))
441 #ifdef GATHER_STATISTICS
443 #endif /* GATHER_STATISTICS */
444 my_friendly_assert (DECL_P (field
), 0);
445 if (DECL_NAME (field
) == NULL_TREE
446 && ANON_AGGR_TYPE_P (TREE_TYPE (field
)))
448 tree temp
= lookup_field_1 (TREE_TYPE (field
), name
, want_type
);
452 if (TREE_CODE (field
) == USING_DECL
)
454 /* We generally treat class-scope using-declarations as
455 ARM-style access specifications, because support for the
456 ISO semantics has not been implemented. So, in general,
457 there's no reason to return a USING_DECL, and the rest of
458 the compiler cannot handle that. Once the class is
459 defined, USING_DECLs are purged from TYPE_FIELDS; see
460 handle_using_decl. However, we make special efforts to
461 make using-declarations in template classes work
463 if (CLASSTYPE_TEMPLATE_INFO (type
)
464 && !CLASSTYPE_USE_TEMPLATE (type
)
465 && !TREE_TYPE (field
))
471 if (DECL_NAME (field
) == name
473 || TREE_CODE (field
) == TYPE_DECL
474 || DECL_CLASS_TEMPLATE_P (field
)))
478 if (name
== vptr_identifier
)
480 /* Give the user what s/he thinks s/he wants. */
481 if (TYPE_POLYMORPHIC_P (type
))
482 return TYPE_VFIELD (type
);
487 /* There are a number of cases we need to be aware of here:
488 current_class_type current_function_decl
495 Those last two make life interesting. If we're in a function which is
496 itself inside a class, we need decls to go into the fn's decls (our
497 second case below). But if we're in a class and the class itself is
498 inside a function, we need decls to go into the decls for the class. To
499 achieve this last goal, we must see if, when both current_class_ptr and
500 current_function_decl are set, the class was declared inside that
501 function. If so, we know to put the decls into the class's scope. */
506 if (current_function_decl
== NULL_TREE
)
507 return current_class_type
;
508 if (current_class_type
== NULL_TREE
)
509 return current_function_decl
;
510 if ((DECL_FUNCTION_MEMBER_P (current_function_decl
)
511 && same_type_p (DECL_CONTEXT (current_function_decl
),
513 || (DECL_FRIEND_CONTEXT (current_function_decl
)
514 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl
),
515 current_class_type
)))
516 return current_function_decl
;
518 return current_class_type
;
521 /* Returns nonzero if we are currently in a function scope. Note
522 that this function returns zero if we are within a local class, but
523 not within a member function body of the local class. */
526 at_function_scope_p (void)
528 tree cs
= current_scope ();
529 return cs
&& TREE_CODE (cs
) == FUNCTION_DECL
;
532 /* Returns true if the innermost active scope is a class scope. */
535 at_class_scope_p (void)
537 tree cs
= current_scope ();
538 return cs
&& TYPE_P (cs
);
541 /* Returns true if the innermost active scope is a namespace scope. */
544 at_namespace_scope_p (void)
546 /* We are in a namespace scope if we are not it a class scope or a
548 return !current_scope();
551 /* Return the scope of DECL, as appropriate when doing name-lookup. */
554 context_for_name_lookup (tree decl
)
558 For the purposes of name lookup, after the anonymous union
559 definition, the members of the anonymous union are considered to
560 have been defined in the scope in which the anonymous union is
562 tree context
= DECL_CONTEXT (decl
);
564 while (context
&& TYPE_P (context
) && ANON_AGGR_TYPE_P (context
))
565 context
= TYPE_CONTEXT (context
);
567 context
= global_namespace
;
572 /* The accessibility routines use BINFO_ACCESS for scratch space
573 during the computation of the accessibility of some declaration. */
575 #define BINFO_ACCESS(NODE) \
576 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE)))
578 /* Set the access associated with NODE to ACCESS. */
580 #define SET_BINFO_ACCESS(NODE, ACCESS) \
581 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \
582 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0))
584 /* Called from access_in_type via dfs_walk. Calculate the access to
585 DATA (which is really a DECL) in BINFO. */
588 dfs_access_in_type (tree binfo
, void *data
)
590 tree decl
= (tree
) data
;
591 tree type
= BINFO_TYPE (binfo
);
592 access_kind access
= ak_none
;
594 if (context_for_name_lookup (decl
) == type
)
596 /* If we have descended to the scope of DECL, just note the
597 appropriate access. */
598 if (TREE_PRIVATE (decl
))
600 else if (TREE_PROTECTED (decl
))
601 access
= ak_protected
;
607 /* First, check for an access-declaration that gives us more
608 access to the DECL. The CONST_DECL for an enumeration
609 constant will not have DECL_LANG_SPECIFIC, and thus no
611 if (DECL_LANG_SPECIFIC (decl
) && !DECL_DISCRIMINATOR_P (decl
))
613 tree decl_access
= purpose_member (type
, DECL_ACCESS (decl
));
617 decl_access
= TREE_VALUE (decl_access
);
619 if (decl_access
== access_public_node
)
621 else if (decl_access
== access_protected_node
)
622 access
= ak_protected
;
623 else if (decl_access
== access_private_node
)
626 my_friendly_assert (false, 20030217);
634 tree binfos
, accesses
;
636 /* Otherwise, scan our baseclasses, and pick the most favorable
638 binfos
= BINFO_BASE_BINFOS (binfo
);
639 accesses
= BINFO_BASE_ACCESSES (binfo
);
640 n_baselinks
= binfos
? TREE_VEC_LENGTH (binfos
) : 0;
641 for (i
= 0; i
< n_baselinks
; ++i
)
643 tree base_binfo
= TREE_VEC_ELT (binfos
, i
);
644 tree base_access
= TREE_VEC_ELT (accesses
, i
);
645 access_kind base_access_now
= BINFO_ACCESS (base_binfo
);
647 if (base_access_now
== ak_none
|| base_access_now
== ak_private
)
648 /* If it was not accessible in the base, or only
649 accessible as a private member, we can't access it
651 base_access_now
= ak_none
;
652 else if (base_access
== access_protected_node
)
653 /* Public and protected members in the base become
655 base_access_now
= ak_protected
;
656 else if (base_access
== access_private_node
)
657 /* Public and protected members in the base become
659 base_access_now
= ak_private
;
661 /* See if the new access, via this base, gives more
662 access than our previous best access. */
663 if (base_access_now
!= ak_none
664 && (access
== ak_none
|| base_access_now
< access
))
666 access
= base_access_now
;
668 /* If the new access is public, we can't do better. */
669 if (access
== ak_public
)
676 /* Note the access to DECL in TYPE. */
677 SET_BINFO_ACCESS (binfo
, access
);
679 /* Mark TYPE as visited so that if we reach it again we do not
680 duplicate our efforts here. */
681 BINFO_MARKED (binfo
) = 1;
686 /* Return the access to DECL in TYPE. */
689 access_in_type (tree type
, tree decl
)
691 tree binfo
= TYPE_BINFO (type
);
693 /* We must take into account
697 If a name can be reached by several paths through a multiple
698 inheritance graph, the access is that of the path that gives
701 The algorithm we use is to make a post-order depth-first traversal
702 of the base-class hierarchy. As we come up the tree, we annotate
703 each node with the most lenient access. */
704 dfs_walk_real (binfo
, 0, dfs_access_in_type
, unmarkedp
, decl
);
705 dfs_walk (binfo
, dfs_unmark
, markedp
, 0);
707 return BINFO_ACCESS (binfo
);
710 /* Called from accessible_p via dfs_walk. */
713 dfs_accessible_queue_p (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
715 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
717 if (BINFO_MARKED (binfo
))
720 /* If this class is inherited via private or protected inheritance,
721 then we can't see it, unless we are a friend of the derived class. */
722 if (BINFO_BASE_ACCESS (derived
, ix
) != access_public_node
723 && !is_friend (BINFO_TYPE (derived
), current_scope ()))
729 /* Called from accessible_p via dfs_walk. */
732 dfs_accessible_p (tree binfo
, void *data ATTRIBUTE_UNUSED
)
736 BINFO_MARKED (binfo
) = 1;
737 access
= BINFO_ACCESS (binfo
);
738 if (access
!= ak_none
739 && is_friend (BINFO_TYPE (binfo
), current_scope ()))
745 /* Returns nonzero if it is OK to access DECL through an object
746 indicated by BINFO in the context of DERIVED. */
749 protected_accessible_p (tree decl
, tree derived
, tree binfo
)
753 /* We're checking this clause from [class.access.base]
755 m as a member of N is protected, and the reference occurs in a
756 member or friend of class N, or in a member or friend of a
757 class P derived from N, where m as a member of P is private or
760 Here DERIVED is a possible P and DECL is m. accessible_p will
761 iterate over various values of N, but the access to m in DERIVED
764 Note that I believe that the passage above is wrong, and should read
765 "...is private or protected or public"; otherwise you get bizarre results
766 whereby a public using-decl can prevent you from accessing a protected
767 member of a base. (jason 2000/02/28) */
769 /* If DERIVED isn't derived from m's class, then it can't be a P. */
770 if (!DERIVED_FROM_P (context_for_name_lookup (decl
), derived
))
773 access
= access_in_type (derived
, decl
);
775 /* If m is inaccessible in DERIVED, then it's not a P. */
776 if (access
== ak_none
)
781 When a friend or a member function of a derived class references
782 a protected nonstatic member of a base class, an access check
783 applies in addition to those described earlier in clause
784 _class.access_) Except when forming a pointer to member
785 (_expr.unary.op_), the access must be through a pointer to,
786 reference to, or object of the derived class itself (or any class
787 derived from that class) (_expr.ref_). If the access is to form
788 a pointer to member, the nested-name-specifier shall name the
789 derived class (or any class derived from that class). */
790 if (DECL_NONSTATIC_MEMBER_P (decl
))
792 /* We can tell through what the reference is occurring by
793 chasing BINFO up to the root. */
795 while (BINFO_INHERITANCE_CHAIN (t
))
796 t
= BINFO_INHERITANCE_CHAIN (t
);
798 if (!DERIVED_FROM_P (derived
, BINFO_TYPE (t
)))
805 /* Returns nonzero if SCOPE is a friend of a type which would be able
806 to access DECL through the object indicated by BINFO. */
809 friend_accessible_p (tree scope
, tree decl
, tree binfo
)
811 tree befriending_classes
;
817 if (TREE_CODE (scope
) == FUNCTION_DECL
818 || DECL_FUNCTION_TEMPLATE_P (scope
))
819 befriending_classes
= DECL_BEFRIENDING_CLASSES (scope
);
820 else if (TYPE_P (scope
))
821 befriending_classes
= CLASSTYPE_BEFRIENDING_CLASSES (scope
);
825 for (t
= befriending_classes
; t
; t
= TREE_CHAIN (t
))
826 if (protected_accessible_p (decl
, TREE_VALUE (t
), binfo
))
829 /* Nested classes are implicitly friends of their enclosing types, as
830 per core issue 45 (this is a change from the standard). */
832 for (t
= TYPE_CONTEXT (scope
); t
&& TYPE_P (t
); t
= TYPE_CONTEXT (t
))
833 if (protected_accessible_p (decl
, t
, binfo
))
836 if (TREE_CODE (scope
) == FUNCTION_DECL
837 || DECL_FUNCTION_TEMPLATE_P (scope
))
839 /* Perhaps this SCOPE is a member of a class which is a
841 if (DECL_CLASS_SCOPE_P (decl
)
842 && friend_accessible_p (DECL_CONTEXT (scope
), decl
, binfo
))
845 /* Or an instantiation of something which is a friend. */
846 if (DECL_TEMPLATE_INFO (scope
))
847 return friend_accessible_p (DECL_TI_TEMPLATE (scope
), decl
, binfo
);
849 else if (CLASSTYPE_TEMPLATE_INFO (scope
))
850 return friend_accessible_p (CLASSTYPE_TI_TEMPLATE (scope
), decl
, binfo
);
855 /* DECL is a declaration from a base class of TYPE, which was the
856 class used to name DECL. Return nonzero if, in the current
857 context, DECL is accessible. If TYPE is actually a BINFO node,
858 then we can tell in what context the access is occurring by looking
859 at the most derived class along the path indicated by BINFO. */
862 accessible_p (tree type
, tree decl
)
869 /* Nonzero if it's OK to access DECL if it has protected
870 accessibility in TYPE. */
871 int protected_ok
= 0;
873 /* If this declaration is in a block or namespace scope, there's no
875 if (!TYPE_P (context_for_name_lookup (decl
)))
878 /* There is no need to perform access checks inside a thunk. */
879 scope
= current_scope ();
880 if (scope
&& DECL_THUNK_P (scope
))
883 /* In a template declaration, we cannot be sure whether the
884 particular specialization that is instantiated will be a friend
885 or not. Therefore, all access checks are deferred until
887 if (processing_template_decl
)
893 type
= BINFO_TYPE (type
);
896 binfo
= TYPE_BINFO (type
);
898 /* [class.access.base]
900 A member m is accessible when named in class N if
902 --m as a member of N is public, or
904 --m as a member of N is private, and the reference occurs in a
905 member or friend of class N, or
907 --m as a member of N is protected, and the reference occurs in a
908 member or friend of class N, or in a member or friend of a
909 class P derived from N, where m as a member of P is private or
912 --there exists a base class B of N that is accessible at the point
913 of reference, and m is accessible when named in class B.
915 We walk the base class hierarchy, checking these conditions. */
917 /* Figure out where the reference is occurring. Check to see if
918 DECL is private or protected in this scope, since that will
919 determine whether protected access is allowed. */
920 if (current_class_type
)
921 protected_ok
= protected_accessible_p (decl
, current_class_type
, binfo
);
923 /* Now, loop through the classes of which we are a friend. */
925 protected_ok
= friend_accessible_p (scope
, decl
, binfo
);
927 /* Standardize the binfo that access_in_type will use. We don't
928 need to know what path was chosen from this point onwards. */
929 binfo
= TYPE_BINFO (type
);
931 /* Compute the accessibility of DECL in the class hierarchy
932 dominated by type. */
933 access
= access_in_type (type
, decl
);
934 if (access
== ak_public
935 || (access
== ak_protected
&& protected_ok
))
939 /* Walk the hierarchy again, looking for a base class that allows
941 t
= dfs_walk (binfo
, dfs_accessible_p
, dfs_accessible_queue_p
, 0);
942 /* Clear any mark bits. Note that we have to walk the whole tree
943 here, since we have aborted the previous walk from some point
945 dfs_walk (binfo
, dfs_unmark
, 0, 0);
947 return t
!= NULL_TREE
;
951 struct lookup_field_info
{
952 /* The type in which we're looking. */
954 /* The name of the field for which we're looking. */
956 /* If non-NULL, the current result of the lookup. */
958 /* The path to RVAL. */
960 /* If non-NULL, the lookup was ambiguous, and this is a list of the
963 /* If nonzero, we are looking for types, not data members. */
965 /* If something went wrong, a message indicating what. */
969 /* Returns nonzero if BINFO is not hidden by the value found by the
970 lookup so far. If BINFO is hidden, then there's no need to look in
971 it. DATA is really a struct lookup_field_info. Called from
972 lookup_field via breadth_first_search. */
975 lookup_field_queue_p (tree derived
, int ix
, void *data
)
977 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
978 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
980 /* Don't look for constructors or destructors in base classes. */
981 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi
->name
))
984 /* If this base class is hidden by the best-known value so far, we
985 don't need to look. */
986 if (lfi
->rval_binfo
&& original_binfo (binfo
, lfi
->rval_binfo
))
989 /* If this is a dependent base, don't look in it. */
990 if (BINFO_DEPENDENT_BASE_P (binfo
))
996 /* Within the scope of a template class, you can refer to the to the
997 current specialization with the name of the template itself. For
1000 template <typename T> struct S { S* sp; }
1002 Returns nonzero if DECL is such a declaration in a class TYPE. */
1005 template_self_reference_p (tree type
, tree decl
)
1007 return (CLASSTYPE_USE_TEMPLATE (type
)
1008 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type
))
1009 && TREE_CODE (decl
) == TYPE_DECL
1010 && DECL_ARTIFICIAL (decl
)
1011 && DECL_NAME (decl
) == constructor_name (type
));
1015 /* Nonzero for a class member means that it is shared between all objects
1018 [class.member.lookup]:If the resulting set of declarations are not all
1019 from sub-objects of the same type, or the set has a nonstatic member
1020 and includes members from distinct sub-objects, there is an ambiguity
1021 and the program is ill-formed.
1023 This function checks that T contains no nonstatic members. */
1026 shared_member_p (tree t
)
1028 if (TREE_CODE (t
) == VAR_DECL
|| TREE_CODE (t
) == TYPE_DECL \
1029 || TREE_CODE (t
) == CONST_DECL
)
1031 if (is_overloaded_fn (t
))
1033 for (; t
; t
= OVL_NEXT (t
))
1035 tree fn
= OVL_CURRENT (t
);
1036 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn
))
1044 /* DATA is really a struct lookup_field_info. Look for a field with
1045 the name indicated there in BINFO. If this function returns a
1046 non-NULL value it is the result of the lookup. Called from
1047 lookup_field via breadth_first_search. */
1050 lookup_field_r (tree binfo
, void *data
)
1052 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
1053 tree type
= BINFO_TYPE (binfo
);
1054 tree nval
= NULL_TREE
;
1056 /* First, look for a function. There can't be a function and a data
1057 member with the same name, and if there's a function and a type
1058 with the same name, the type is hidden by the function. */
1059 if (!lfi
->want_type
)
1061 int idx
= lookup_fnfields_1 (type
, lfi
->name
);
1063 nval
= VEC_index (tree
, CLASSTYPE_METHOD_VEC (type
), idx
);
1067 /* Look for a data member or type. */
1068 nval
= lookup_field_1 (type
, lfi
->name
, lfi
->want_type
);
1070 /* If there is no declaration with the indicated name in this type,
1071 then there's nothing to do. */
1075 /* If we're looking up a type (as with an elaborated type specifier)
1076 we ignore all non-types we find. */
1077 if (lfi
->want_type
&& TREE_CODE (nval
) != TYPE_DECL
1078 && !DECL_CLASS_TEMPLATE_P (nval
))
1080 if (lfi
->name
== TYPE_IDENTIFIER (type
))
1082 /* If the aggregate has no user defined constructors, we allow
1083 it to have fields with the same name as the enclosing type.
1084 If we are looking for that name, find the corresponding
1086 for (nval
= TREE_CHAIN (nval
); nval
; nval
= TREE_CHAIN (nval
))
1087 if (DECL_NAME (nval
) == lfi
->name
1088 && TREE_CODE (nval
) == TYPE_DECL
)
1093 if (!nval
&& CLASSTYPE_NESTED_UTDS (type
) != NULL
)
1095 binding_entry e
= binding_table_find (CLASSTYPE_NESTED_UTDS (type
),
1098 nval
= TYPE_MAIN_DECL (e
->type
);
1104 /* You must name a template base class with a template-id. */
1105 if (!same_type_p (type
, lfi
->type
)
1106 && template_self_reference_p (type
, nval
))
1109 /* If the lookup already found a match, and the new value doesn't
1110 hide the old one, we might have an ambiguity. */
1111 if (lfi
->rval_binfo
&& !original_binfo (lfi
->rval_binfo
, binfo
))
1113 if (nval
== lfi
->rval
&& shared_member_p (nval
))
1114 /* The two things are really the same. */
1116 else if (original_binfo (binfo
, lfi
->rval_binfo
))
1117 /* The previous value hides the new one. */
1121 /* We have a real ambiguity. We keep a chain of all the
1123 if (!lfi
->ambiguous
&& lfi
->rval
)
1125 /* This is the first time we noticed an ambiguity. Add
1126 what we previously thought was a reasonable candidate
1128 lfi
->ambiguous
= tree_cons (NULL_TREE
, lfi
->rval
, NULL_TREE
);
1129 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1132 /* Add the new value. */
1133 lfi
->ambiguous
= tree_cons (NULL_TREE
, nval
, lfi
->ambiguous
);
1134 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1135 lfi
->errstr
= "request for member `%D' is ambiguous";
1141 lfi
->rval_binfo
= binfo
;
1147 /* Return a "baselink" which BASELINK_BINFO, BASELINK_ACCESS_BINFO,
1148 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO,
1149 FUNCTIONS, and OPTYPE respectively. */
1152 build_baselink (tree binfo
, tree access_binfo
, tree functions
, tree optype
)
1156 my_friendly_assert (TREE_CODE (functions
) == FUNCTION_DECL
1157 || TREE_CODE (functions
) == TEMPLATE_DECL
1158 || TREE_CODE (functions
) == TEMPLATE_ID_EXPR
1159 || TREE_CODE (functions
) == OVERLOAD
,
1161 my_friendly_assert (!optype
|| TYPE_P (optype
), 20020730);
1162 my_friendly_assert (TREE_TYPE (functions
), 20020805);
1164 baselink
= make_node (BASELINK
);
1165 TREE_TYPE (baselink
) = TREE_TYPE (functions
);
1166 BASELINK_BINFO (baselink
) = binfo
;
1167 BASELINK_ACCESS_BINFO (baselink
) = access_binfo
;
1168 BASELINK_FUNCTIONS (baselink
) = functions
;
1169 BASELINK_OPTYPE (baselink
) = optype
;
1174 /* Look for a member named NAME in an inheritance lattice dominated by
1175 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it
1176 is 1, we enforce accessibility. If PROTECT is zero, then, for an
1177 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error
1178 messages about inaccessible or ambiguous lookup. If PROTECT is 2,
1179 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose
1180 TREE_VALUEs are the list of ambiguous candidates.
1182 WANT_TYPE is 1 when we should only return TYPE_DECLs.
1184 If nothing can be found return NULL_TREE and do not issue an error. */
1187 lookup_member (tree xbasetype
, tree name
, int protect
, bool want_type
)
1189 tree rval
, rval_binfo
= NULL_TREE
;
1190 tree type
= NULL_TREE
, basetype_path
= NULL_TREE
;
1191 struct lookup_field_info lfi
;
1193 /* rval_binfo is the binfo associated with the found member, note,
1194 this can be set with useful information, even when rval is not
1195 set, because it must deal with ALL members, not just non-function
1196 members. It is used for ambiguity checking and the hidden
1197 checks. Whereas rval is only set if a proper (not hidden)
1198 non-function member is found. */
1200 const char *errstr
= 0;
1202 my_friendly_assert (TREE_CODE (name
) == IDENTIFIER_NODE
, 20030624);
1204 if (TREE_CODE (xbasetype
) == TREE_BINFO
)
1206 type
= BINFO_TYPE (xbasetype
);
1207 basetype_path
= xbasetype
;
1211 my_friendly_assert (IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype
)), 20030624);
1213 xbasetype
= NULL_TREE
;
1216 type
= complete_type (type
);
1218 basetype_path
= TYPE_BINFO (type
);
1223 #ifdef GATHER_STATISTICS
1224 n_calls_lookup_field
++;
1225 #endif /* GATHER_STATISTICS */
1227 memset (&lfi
, 0, sizeof (lfi
));
1230 lfi
.want_type
= want_type
;
1231 bfs_walk (basetype_path
, &lookup_field_r
, &lookup_field_queue_p
, &lfi
);
1233 rval_binfo
= lfi
.rval_binfo
;
1235 type
= BINFO_TYPE (rval_binfo
);
1236 errstr
= lfi
.errstr
;
1238 /* If we are not interested in ambiguities, don't report them;
1239 just return NULL_TREE. */
1240 if (!protect
&& lfi
.ambiguous
)
1246 return lfi
.ambiguous
;
1253 In the case of overloaded function names, access control is
1254 applied to the function selected by overloaded resolution. */
1255 if (rval
&& protect
&& !is_overloaded_fn (rval
))
1256 perform_or_defer_access_check (basetype_path
, rval
);
1258 if (errstr
&& protect
)
1260 error (errstr
, name
, type
);
1262 print_candidates (lfi
.ambiguous
);
1263 rval
= error_mark_node
;
1266 if (rval
&& is_overloaded_fn (rval
))
1267 rval
= build_baselink (rval_binfo
, basetype_path
, rval
,
1268 (IDENTIFIER_TYPENAME_P (name
)
1269 ? TREE_TYPE (name
): NULL_TREE
));
1273 /* Like lookup_member, except that if we find a function member we
1274 return NULL_TREE. */
1277 lookup_field (tree xbasetype
, tree name
, int protect
, bool want_type
)
1279 tree rval
= lookup_member (xbasetype
, name
, protect
, want_type
);
1281 /* Ignore functions, but propagate the ambiguity list. */
1282 if (!error_operand_p (rval
)
1283 && (rval
&& BASELINK_P (rval
)))
1289 /* Like lookup_member, except that if we find a non-function member we
1290 return NULL_TREE. */
1293 lookup_fnfields (tree xbasetype
, tree name
, int protect
)
1295 tree rval
= lookup_member (xbasetype
, name
, protect
, /*want_type=*/false);
1297 /* Ignore non-functions, but propagate the ambiguity list. */
1298 if (!error_operand_p (rval
)
1299 && (rval
&& !BASELINK_P (rval
)))
1305 /* Return the index in the CLASSTYPE_METHOD_VEC for CLASS_TYPE
1306 corresponding to "operator TYPE ()", or -1 if there is no such
1307 operator. Only CLASS_TYPE itself is searched; this routine does
1308 not scan the base classes of CLASS_TYPE. */
1311 lookup_conversion_operator (tree class_type
, tree type
)
1318 methods
= CLASSTYPE_METHOD_VEC (class_type
);
1320 for (pass
= 0; pass
< 2; ++pass
)
1321 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
1322 (fn
= VEC_iterate (tree
, methods
, i
));
1325 /* All the conversion operators come near the beginning of the
1326 class. Therefore, if FN is not a conversion operator, there
1327 is no matching conversion operator in CLASS_TYPE. */
1328 fn
= OVL_CURRENT (fn
);
1329 if (!DECL_CONV_FN_P (fn
))
1334 /* On the first pass we only consider exact matches. If
1335 the types match, this slot is the one where the right
1336 conversion operators can be found. */
1337 if (TREE_CODE (fn
) != TEMPLATE_DECL
1338 && same_type_p (DECL_CONV_FN_TYPE (fn
), type
))
1343 /* On the second pass we look for template conversion
1344 operators. It may be possible to instantiate the
1345 template to get the type desired. All of the template
1346 conversion operators share a slot. By looking for
1347 templates second we ensure that specializations are
1348 preferred over templates. */
1349 if (TREE_CODE (fn
) == TEMPLATE_DECL
)
1357 /* TYPE is a class type. Return the index of the fields within
1358 the method vector with name NAME, or -1 is no such field exists. */
1361 lookup_fnfields_1 (tree type
, tree name
)
1363 VEC(tree
) *method_vec
;
1368 if (!CLASS_TYPE_P (type
))
1371 method_vec
= CLASSTYPE_METHOD_VEC (type
);
1376 #ifdef GATHER_STATISTICS
1377 n_calls_lookup_fnfields_1
++;
1378 #endif /* GATHER_STATISTICS */
1380 /* Constructors are first... */
1381 if (name
== ctor_identifier
)
1383 fn
= CLASSTYPE_CONSTRUCTORS (type
);
1384 return fn
? CLASSTYPE_CONSTRUCTOR_SLOT
: -1;
1386 /* and destructors are second. */
1387 if (name
== dtor_identifier
)
1389 fn
= CLASSTYPE_DESTRUCTORS (type
);
1390 return fn
? CLASSTYPE_DESTRUCTOR_SLOT
: -1;
1392 if (IDENTIFIER_TYPENAME_P (name
))
1393 return lookup_conversion_operator (type
, TREE_TYPE (name
));
1395 /* Skip the conversion operators. */
1396 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
1397 (fn
= VEC_iterate (tree
, method_vec
, i
));
1399 if (!DECL_CONV_FN_P (OVL_CURRENT (fn
)))
1402 /* If the type is complete, use binary search. */
1403 if (COMPLETE_TYPE_P (type
))
1408 /* All non-Java classes have "operator=" -- but we do not
1409 actually create the declaration until it is needed. */
1410 if (name
== ansi_assopname(NOP_EXPR
)
1411 && !TYPE_HAS_ASSIGN_REF (type
)
1412 && !TYPE_FOR_JAVA (type
))
1416 /* Declare the function. */
1417 fn
= implicitly_declare_fn (sfk_assignment_operator
, type
,
1418 TYPE_HAS_CONST_ASSIGN_REF (type
));
1419 add_method (type
, fn
);
1420 TREE_CHAIN (fn
) = TYPE_METHODS (type
);
1421 TYPE_METHODS (type
) = fn
;
1422 maybe_add_class_template_decl_list (type
, fn
, /*friend_p=*/0);
1423 method_vec
= CLASSTYPE_METHOD_VEC (type
);
1427 hi
= VEC_length (tree
, method_vec
);
1432 #ifdef GATHER_STATISTICS
1433 n_outer_fields_searched
++;
1434 #endif /* GATHER_STATISTICS */
1436 tmp
= VEC_index (tree
, method_vec
, i
);
1437 tmp
= DECL_NAME (OVL_CURRENT (tmp
));
1440 else if (tmp
< name
)
1448 (fn
= VEC_iterate (tree
, method_vec
, i
));
1451 #ifdef GATHER_STATISTICS
1452 n_outer_fields_searched
++;
1453 #endif /* GATHER_STATISTICS */
1454 if (DECL_NAME (OVL_CURRENT (fn
)) == name
)
1461 /* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is
1462 the class or namespace used to qualify the name. CONTEXT_CLASS is
1463 the class corresponding to the object in which DECL will be used.
1464 Return a possibly modified version of DECL that takes into account
1467 In particular, consider an expression like `B::m' in the context of
1468 a derived class `D'. If `B::m' has been resolved to a BASELINK,
1469 then the most derived class indicated by the BASELINK_BINFO will be
1470 `B', not `D'. This function makes that adjustment. */
1473 adjust_result_of_qualified_name_lookup (tree decl
,
1474 tree qualifying_scope
,
1477 if (context_class
&& CLASS_TYPE_P (qualifying_scope
)
1478 && DERIVED_FROM_P (qualifying_scope
, context_class
)
1479 && BASELINK_P (decl
))
1483 my_friendly_assert (CLASS_TYPE_P (context_class
), 20020808);
1485 /* Look for the QUALIFYING_SCOPE as a base of the CONTEXT_CLASS.
1486 Because we do not yet know which function will be chosen by
1487 overload resolution, we cannot yet check either accessibility
1488 or ambiguity -- in either case, the choice of a static member
1489 function might make the usage valid. */
1490 base
= lookup_base (context_class
, qualifying_scope
,
1491 ba_ignore
| ba_quiet
, NULL
);
1494 BASELINK_ACCESS_BINFO (decl
) = base
;
1495 BASELINK_BINFO (decl
)
1496 = lookup_base (base
, BINFO_TYPE (BASELINK_BINFO (decl
)),
1497 ba_ignore
| ba_quiet
,
1506 /* Walk the class hierarchy dominated by TYPE. FN is called for each
1507 type in the hierarchy, in a breadth-first preorder traversal.
1508 If it ever returns a non-NULL value, that value is immediately
1509 returned and the walk is terminated. At each node, FN is passed a
1510 BINFO indicating the path from the currently visited base-class to
1511 TYPE. Before each base-class is walked QFN is called. If the
1512 value returned is nonzero, the base-class is walked; otherwise it
1513 is not. If QFN is NULL, it is treated as a function which always
1514 returns 1. Both FN and QFN are passed the DATA whenever they are
1517 Implementation notes: Uses a circular queue, which starts off on
1518 the stack but gets moved to the malloc arena if it needs to be
1519 enlarged. The underflow and overflow conditions are
1520 indistinguishable except by context: if head == tail and we just
1521 moved the head pointer, the queue is empty, but if we just moved
1522 the tail pointer, the queue is full.
1523 Start with enough room for ten concurrent base classes. That
1524 will be enough for most hierarchies. */
1525 #define BFS_WALK_INITIAL_QUEUE_SIZE 10
1528 bfs_walk (tree binfo
,
1529 tree (*fn
) (tree
, void *),
1530 tree (*qfn
) (tree
, int, void *),
1533 tree rval
= NULL_TREE
;
1535 tree bases_initial
[BFS_WALK_INITIAL_QUEUE_SIZE
];
1536 /* A circular queue of the base classes of BINFO. These will be
1537 built up in breadth-first order, except where QFN prunes the
1540 size_t base_buffer_size
= BFS_WALK_INITIAL_QUEUE_SIZE
;
1541 tree
*base_buffer
= bases_initial
;
1544 base_buffer
[tail
++] = binfo
;
1546 while (head
!= tail
)
1549 tree binfo
= base_buffer
[head
++];
1550 if (head
== base_buffer_size
)
1553 /* Is this the one we're looking for? If so, we're done. */
1554 rval
= fn (binfo
, data
);
1558 n_bases
= BINFO_N_BASE_BINFOS (binfo
);
1559 for (ix
= 0; ix
!= n_bases
; ix
++)
1564 base_binfo
= (*qfn
) (binfo
, ix
, data
);
1566 base_binfo
= BINFO_BASE_BINFO (binfo
, ix
);
1570 base_buffer
[tail
++] = base_binfo
;
1571 if (tail
== base_buffer_size
)
1575 tree
*new_buffer
= xmalloc (2 * base_buffer_size
1577 memcpy (&new_buffer
[0], &base_buffer
[0],
1578 tail
* sizeof (tree
));
1579 memcpy (&new_buffer
[head
+ base_buffer_size
],
1581 (base_buffer_size
- head
) * sizeof (tree
));
1582 if (base_buffer_size
!= BFS_WALK_INITIAL_QUEUE_SIZE
)
1584 base_buffer
= new_buffer
;
1585 head
+= base_buffer_size
;
1586 base_buffer_size
*= 2;
1593 if (base_buffer_size
!= BFS_WALK_INITIAL_QUEUE_SIZE
)
1598 /* Exactly like bfs_walk, except that a depth-first traversal is
1599 performed, and PREFN is called in preorder, while POSTFN is called
1603 dfs_walk_real (tree binfo
,
1604 tree (*prefn
) (tree
, void *),
1605 tree (*postfn
) (tree
, void *),
1606 tree (*qfn
) (tree
, int, void *),
1609 tree rval
= NULL_TREE
;
1611 /* Call the pre-order walking function. */
1614 rval
= (*prefn
) (binfo
, data
);
1619 /* Process the basetypes. */
1620 if (BINFO_BASE_BINFOS (binfo
))
1622 int i
, n
= TREE_VEC_LENGTH (BINFO_BASE_BINFOS (binfo
));
1623 for (i
= 0; i
!= n
; i
++)
1628 base_binfo
= (*qfn
) (binfo
, i
, data
);
1630 base_binfo
= BINFO_BASE_BINFO (binfo
, i
);
1634 rval
= dfs_walk_real (base_binfo
, prefn
, postfn
, qfn
, data
);
1641 /* Call the post-order walking function. */
1643 rval
= (*postfn
) (binfo
, data
);
1648 /* Exactly like bfs_walk, except that a depth-first post-order traversal is
1652 dfs_walk (tree binfo
,
1653 tree (*fn
) (tree
, void *),
1654 tree (*qfn
) (tree
, int, void *),
1657 return dfs_walk_real (binfo
, 0, fn
, qfn
, data
);
1660 /* Check that virtual overrider OVERRIDER is acceptable for base function
1661 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
1664 check_final_overrider (tree overrider
, tree basefn
)
1666 tree over_type
= TREE_TYPE (overrider
);
1667 tree base_type
= TREE_TYPE (basefn
);
1668 tree over_return
= TREE_TYPE (over_type
);
1669 tree base_return
= TREE_TYPE (base_type
);
1670 tree over_throw
= TYPE_RAISES_EXCEPTIONS (over_type
);
1671 tree base_throw
= TYPE_RAISES_EXCEPTIONS (base_type
);
1674 if (DECL_INVALID_OVERRIDER_P (overrider
))
1677 if (same_type_p (base_return
, over_return
))
1679 else if ((CLASS_TYPE_P (over_return
) && CLASS_TYPE_P (base_return
))
1680 || (TREE_CODE (base_return
) == TREE_CODE (over_return
)
1681 && POINTER_TYPE_P (base_return
)))
1683 /* Potentially covariant. */
1684 unsigned base_quals
, over_quals
;
1686 fail
= !POINTER_TYPE_P (base_return
);
1689 fail
= cp_type_quals (base_return
) != cp_type_quals (over_return
);
1691 base_return
= TREE_TYPE (base_return
);
1692 over_return
= TREE_TYPE (over_return
);
1694 base_quals
= cp_type_quals (base_return
);
1695 over_quals
= cp_type_quals (over_return
);
1697 if ((base_quals
& over_quals
) != over_quals
)
1700 if (CLASS_TYPE_P (base_return
) && CLASS_TYPE_P (over_return
))
1702 tree binfo
= lookup_base (over_return
, base_return
,
1703 ba_check
| ba_quiet
, NULL
);
1709 && can_convert (TREE_TYPE (base_type
), TREE_TYPE (over_type
)))
1710 /* GNU extension, allow trivial pointer conversions such as
1711 converting to void *, or qualification conversion. */
1713 /* can_convert will permit user defined conversion from a
1714 (reference to) class type. We must reject them. */
1715 over_return
= non_reference (TREE_TYPE (over_type
));
1716 if (CLASS_TYPE_P (over_return
))
1730 cp_error_at ("invalid covariant return type for `%#D'", overrider
);
1731 cp_error_at (" overriding `%#D'", basefn
);
1735 cp_error_at ("conflicting return type specified for `%#D'",
1737 cp_error_at (" overriding `%#D'", basefn
);
1739 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1743 /* Check throw specifier is at least as strict. */
1744 if (!comp_except_specs (base_throw
, over_throw
, 0))
1746 cp_error_at ("looser throw specifier for `%#F'", overrider
);
1747 cp_error_at (" overriding `%#F'", basefn
);
1748 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1755 /* Given a class TYPE, and a function decl FNDECL, look for
1756 virtual functions in TYPE's hierarchy which FNDECL overrides.
1757 We do not look in TYPE itself, only its bases.
1759 Returns nonzero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
1760 find that it overrides anything.
1762 We check that every function which is overridden, is correctly
1766 look_for_overrides (tree type
, tree fndecl
)
1768 tree binfo
= TYPE_BINFO (type
);
1769 tree basebinfos
= BINFO_BASE_BINFOS (binfo
);
1770 int nbasebinfos
= basebinfos
? TREE_VEC_LENGTH (basebinfos
) : 0;
1774 for (ix
= 0; ix
!= nbasebinfos
; ix
++)
1776 tree basetype
= BINFO_TYPE (TREE_VEC_ELT (basebinfos
, ix
));
1778 if (TYPE_POLYMORPHIC_P (basetype
))
1779 found
+= look_for_overrides_r (basetype
, fndecl
);
1784 /* Look in TYPE for virtual functions with the same signature as
1788 look_for_overrides_here (tree type
, tree fndecl
)
1792 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl
))
1793 ix
= CLASSTYPE_DESTRUCTOR_SLOT
;
1795 ix
= lookup_fnfields_1 (type
, DECL_NAME (fndecl
));
1798 tree fns
= VEC_index (tree
, CLASSTYPE_METHOD_VEC (type
), ix
);
1800 for (; fns
; fns
= OVL_NEXT (fns
))
1802 tree fn
= OVL_CURRENT (fns
);
1804 if (!DECL_VIRTUAL_P (fn
))
1805 /* Not a virtual. */;
1806 else if (DECL_CONTEXT (fn
) != type
)
1807 /* Introduced with a using declaration. */;
1808 else if (DECL_STATIC_FUNCTION_P (fndecl
))
1810 tree btypes
= TYPE_ARG_TYPES (TREE_TYPE (fn
));
1811 tree dtypes
= TYPE_ARG_TYPES (TREE_TYPE (fndecl
));
1812 if (compparms (TREE_CHAIN (btypes
), dtypes
))
1815 else if (same_signature_p (fndecl
, fn
))
1822 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
1823 TYPE itself and its bases. */
1826 look_for_overrides_r (tree type
, tree fndecl
)
1828 tree fn
= look_for_overrides_here (type
, fndecl
);
1831 if (DECL_STATIC_FUNCTION_P (fndecl
))
1833 /* A static member function cannot match an inherited
1834 virtual member function. */
1835 cp_error_at ("`%#D' cannot be declared", fndecl
);
1836 cp_error_at (" since `%#D' declared in base class", fn
);
1840 /* It's definitely virtual, even if not explicitly set. */
1841 DECL_VIRTUAL_P (fndecl
) = 1;
1842 check_final_overrider (fndecl
, fn
);
1847 /* We failed to find one declared in this class. Look in its bases. */
1848 return look_for_overrides (type
, fndecl
);
1851 /* Called via dfs_walk from dfs_get_pure_virtuals. */
1854 dfs_get_pure_virtuals (tree binfo
, void *data
)
1856 tree type
= (tree
) data
;
1858 /* We're not interested in primary base classes; the derived class
1859 of which they are a primary base will contain the information we
1861 if (!BINFO_PRIMARY_P (binfo
))
1865 for (virtuals
= BINFO_VIRTUALS (binfo
);
1867 virtuals
= TREE_CHAIN (virtuals
))
1868 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals
)))
1869 CLASSTYPE_PURE_VIRTUALS (type
)
1870 = tree_cons (NULL_TREE
, BV_FN (virtuals
),
1871 CLASSTYPE_PURE_VIRTUALS (type
));
1874 BINFO_MARKED (binfo
) = 1;
1879 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
1882 get_pure_virtuals (tree type
)
1887 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
1888 is going to be overridden. */
1889 CLASSTYPE_PURE_VIRTUALS (type
) = NULL_TREE
;
1890 /* Now, run through all the bases which are not primary bases, and
1891 collect the pure virtual functions. We look at the vtable in
1892 each class to determine what pure virtual functions are present.
1893 (A primary base is not interesting because the derived class of
1894 which it is a primary base will contain vtable entries for the
1895 pure virtuals in the base class. */
1896 dfs_walk (TYPE_BINFO (type
), dfs_get_pure_virtuals
, unmarkedp
, type
);
1897 dfs_walk (TYPE_BINFO (type
), dfs_unmark
, markedp
, type
);
1899 /* Put the pure virtuals in dfs order. */
1900 CLASSTYPE_PURE_VIRTUALS (type
) = nreverse (CLASSTYPE_PURE_VIRTUALS (type
));
1902 for (ix
= 0; (binfo
= VEC_iterate
1903 (tree
, CLASSTYPE_VBASECLASSES (type
), ix
)); ix
++)
1907 for (virtuals
= BINFO_VIRTUALS (binfo
); virtuals
;
1908 virtuals
= TREE_CHAIN (virtuals
))
1910 tree base_fndecl
= BV_FN (virtuals
);
1911 if (DECL_NEEDS_FINAL_OVERRIDER_P (base_fndecl
))
1912 error ("`%#D' needs a final overrider", base_fndecl
);
1917 /* DEPTH-FIRST SEARCH ROUTINES. */
1920 markedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1922 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1924 return BINFO_MARKED (binfo
) ? binfo
: NULL_TREE
;
1928 unmarkedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1930 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1932 return !BINFO_MARKED (binfo
) ? binfo
: NULL_TREE
;
1935 /* The worker functions for `dfs_walk'. These do not need to
1936 test anything (vis a vis marking) if they are paired with
1937 a predicate function (above). */
1940 dfs_unmark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
1942 BINFO_MARKED (binfo
) = 0;
1947 /* Debug info for C++ classes can get very large; try to avoid
1948 emitting it everywhere.
1950 Note that this optimization wins even when the target supports
1951 BINCL (if only slightly), and reduces the amount of work for the
1955 maybe_suppress_debug_info (tree t
)
1957 /* We can't do the usual TYPE_DECL_SUPPRESS_DEBUG thing with DWARF, which
1958 does not support name references between translation units. It supports
1959 symbolic references between translation units, but only within a single
1960 executable or shared library.
1962 For DWARF 2, we handle TYPE_DECL_SUPPRESS_DEBUG by pretending
1963 that the type was never defined, so we only get the members we
1965 if (write_symbols
== DWARF_DEBUG
|| write_symbols
== NO_DEBUG
)
1968 /* We might have set this earlier in cp_finish_decl. */
1969 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 0;
1971 /* If we already know how we're handling this class, handle debug info
1973 if (CLASSTYPE_INTERFACE_KNOWN (t
))
1975 if (CLASSTYPE_INTERFACE_ONLY (t
))
1976 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
1977 /* else don't set it. */
1979 /* If the class has a vtable, write out the debug info along with
1981 else if (TYPE_CONTAINS_VPTR_P (t
))
1982 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
1984 /* Otherwise, just emit the debug info normally. */
1987 /* Note that we want debugging information for a base class of a class
1988 whose vtable is being emitted. Normally, this would happen because
1989 calling the constructor for a derived class implies calling the
1990 constructors for all bases, which involve initializing the
1991 appropriate vptr with the vtable for the base class; but in the
1992 presence of optimization, this initialization may be optimized
1993 away, so we tell finish_vtable_vardecl that we want the debugging
1994 information anyway. */
1997 dfs_debug_mark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
1999 tree t
= BINFO_TYPE (binfo
);
2001 CLASSTYPE_DEBUG_REQUESTED (t
) = 1;
2006 /* Returns BINFO if we haven't already noted that we want debugging
2007 info for this base class. */
2010 dfs_debug_unmarkedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
2012 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
2014 return (!CLASSTYPE_DEBUG_REQUESTED (BINFO_TYPE (binfo
))
2015 ? binfo
: NULL_TREE
);
2018 /* Write out the debugging information for TYPE, whose vtable is being
2019 emitted. Also walk through our bases and note that we want to
2020 write out information for them. This avoids the problem of not
2021 writing any debug info for intermediate basetypes whose
2022 constructors, and thus the references to their vtables, and thus
2023 the vtables themselves, were optimized away. */
2026 note_debug_info_needed (tree type
)
2028 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)))
2030 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)) = 0;
2031 rest_of_type_compilation (type
, toplevel_bindings_p ());
2034 dfs_walk (TYPE_BINFO (type
), dfs_debug_mark
, dfs_debug_unmarkedp
, 0);
2038 print_search_statistics (void)
2040 #ifdef GATHER_STATISTICS
2041 fprintf (stderr
, "%d fields searched in %d[%d] calls to lookup_field[_1]\n",
2042 n_fields_searched
, n_calls_lookup_field
, n_calls_lookup_field_1
);
2043 fprintf (stderr
, "%d fnfields searched in %d calls to lookup_fnfields\n",
2044 n_outer_fields_searched
, n_calls_lookup_fnfields
);
2045 fprintf (stderr
, "%d calls to get_base_type\n", n_calls_get_base_type
);
2046 #else /* GATHER_STATISTICS */
2047 fprintf (stderr
, "no search statistics\n");
2048 #endif /* GATHER_STATISTICS */
2052 reinit_search_statistics (void)
2054 #ifdef GATHER_STATISTICS
2055 n_fields_searched
= 0;
2056 n_calls_lookup_field
= 0, n_calls_lookup_field_1
= 0;
2057 n_calls_lookup_fnfields
= 0, n_calls_lookup_fnfields_1
= 0;
2058 n_calls_get_base_type
= 0;
2059 n_outer_fields_searched
= 0;
2060 n_contexts_saved
= 0;
2061 #endif /* GATHER_STATISTICS */
2065 add_conversions (tree binfo
, void *data
)
2068 VEC(tree
) *method_vec
= CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo
));
2069 tree
*conversions
= (tree
*) data
;
2072 /* Some builtin types have no method vector, not even an empty one. */
2076 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
2077 (tmp
= VEC_iterate (tree
, method_vec
, i
));
2082 if (!tmp
|| ! DECL_CONV_FN_P (OVL_CURRENT (tmp
)))
2085 name
= DECL_NAME (OVL_CURRENT (tmp
));
2087 /* Make sure we don't already have this conversion. */
2088 if (! IDENTIFIER_MARKED (name
))
2092 /* Make sure that we do not already have a conversion
2093 operator for this type. Merely checking the NAME is not
2094 enough because two conversion operators to the same type
2095 may not have the same NAME. */
2096 for (t
= *conversions
; t
; t
= TREE_CHAIN (t
))
2099 for (fn
= TREE_VALUE (t
); fn
; fn
= OVL_NEXT (fn
))
2100 if (same_type_p (TREE_TYPE (name
),
2101 DECL_CONV_FN_TYPE (OVL_CURRENT (fn
))))
2108 *conversions
= tree_cons (binfo
, tmp
, *conversions
);
2109 IDENTIFIER_MARKED (name
) = 1;
2116 /* Return a TREE_LIST containing all the non-hidden user-defined
2117 conversion functions for TYPE (and its base-classes). The
2118 TREE_VALUE of each node is a FUNCTION_DECL or an OVERLOAD
2119 containing the conversion functions. The TREE_PURPOSE is the BINFO
2120 from which the conversion functions in this node were selected. */
2123 lookup_conversions (tree type
)
2126 tree conversions
= NULL_TREE
;
2128 complete_type (type
);
2129 if (TYPE_BINFO (type
))
2130 bfs_walk (TYPE_BINFO (type
), add_conversions
, 0, &conversions
);
2132 for (t
= conversions
; t
; t
= TREE_CHAIN (t
))
2133 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (t
)))) = 0;
2144 /* Check whether the empty class indicated by EMPTY_BINFO is also present
2145 at offset 0 in COMPARE_TYPE, and set found_overlap if so. */
2148 dfs_check_overlap (tree empty_binfo
, void *data
)
2150 struct overlap_info
*oi
= (struct overlap_info
*) data
;
2152 for (binfo
= TYPE_BINFO (oi
->compare_type
);
2154 binfo
= BINFO_BASE_BINFO (binfo
, 0))
2156 if (BINFO_TYPE (binfo
) == BINFO_TYPE (empty_binfo
))
2158 oi
->found_overlap
= 1;
2161 else if (BINFO_BASE_BINFOS (binfo
) == NULL_TREE
)
2168 /* Trivial function to stop base traversal when we find something. */
2171 dfs_no_overlap_yet (tree derived
, int ix
, void *data
)
2173 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
2174 struct overlap_info
*oi
= (struct overlap_info
*) data
;
2176 return !oi
->found_overlap
? binfo
: NULL_TREE
;
2179 /* Returns nonzero if EMPTY_TYPE or any of its bases can also be found at
2180 offset 0 in NEXT_TYPE. Used in laying out empty base class subobjects. */
2183 types_overlap_p (tree empty_type
, tree next_type
)
2185 struct overlap_info oi
;
2187 if (! IS_AGGR_TYPE (next_type
))
2189 oi
.compare_type
= next_type
;
2190 oi
.found_overlap
= 0;
2191 dfs_walk (TYPE_BINFO (empty_type
), dfs_check_overlap
,
2192 dfs_no_overlap_yet
, &oi
);
2193 return oi
.found_overlap
;
2196 /* Given a vtable VAR, determine which of the inherited classes the vtable
2197 inherits (in a loose sense) functions from.
2199 FIXME: This does not work with the new ABI. */
2202 binfo_for_vtable (tree var
)
2204 tree main_binfo
= TYPE_BINFO (DECL_CONTEXT (var
));
2205 tree binfos
= BINFO_BASE_BINFOS (TYPE_BINFO (BINFO_TYPE (main_binfo
)));
2206 int n_baseclasses
= BINFO_N_BASE_BINFOS (TYPE_BINFO (BINFO_TYPE (main_binfo
)));
2209 for (i
= 0; i
< n_baseclasses
; i
++)
2211 tree base_binfo
= TREE_VEC_ELT (binfos
, i
);
2212 if (base_binfo
!= NULL_TREE
&& BINFO_VTABLE (base_binfo
) == var
)
2216 /* If no secondary base classes matched, return the primary base, if
2218 if (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (main_binfo
)))
2219 return get_primary_binfo (main_binfo
);
2224 /* Returns the binfo of the first direct or indirect virtual base derived
2225 from BINFO, or NULL if binfo is not via virtual. */
2228 binfo_from_vbase (tree binfo
)
2230 for (; binfo
; binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2232 if (BINFO_VIRTUAL_P (binfo
))
2238 /* Returns the binfo of the first direct or indirect virtual base derived
2239 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
2243 binfo_via_virtual (tree binfo
, tree limit
)
2245 for (; binfo
&& (!limit
|| !same_type_p (BINFO_TYPE (binfo
), limit
));
2246 binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2248 if (BINFO_VIRTUAL_P (binfo
))
2254 /* BINFO is a base binfo in the complete type BINFO_TYPE (HERE).
2255 Find the equivalent binfo within whatever graph HERE is located.
2256 This is the inverse of original_binfo. */
2259 copied_binfo (tree binfo
, tree here
)
2261 tree result
= NULL_TREE
;
2263 if (BINFO_VIRTUAL_P (binfo
))
2267 for (t
= here
; BINFO_INHERITANCE_CHAIN (t
);
2268 t
= BINFO_INHERITANCE_CHAIN (t
))
2271 result
= binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (t
));
2273 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2278 base_binfos
= copied_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2279 base_binfos
= BINFO_BASE_BINFOS (base_binfos
);
2280 n
= TREE_VEC_LENGTH (base_binfos
);
2281 for (ix
= 0; ix
!= n
; ix
++)
2283 tree base
= TREE_VEC_ELT (base_binfos
, ix
);
2285 if (BINFO_TYPE (base
) == BINFO_TYPE (binfo
))
2294 my_friendly_assert (BINFO_TYPE (here
) == BINFO_TYPE (binfo
), 20030202);
2298 my_friendly_assert (result
, 20030202);
2303 binfo_for_vbase (tree base
, tree t
)
2308 for (ix
= 0; (binfo
= VEC_iterate
2309 (tree
, CLASSTYPE_VBASECLASSES (t
), ix
)); ix
++)
2310 if (BINFO_TYPE (binfo
) == base
)
2315 /* BINFO is some base binfo of HERE, within some other
2316 hierarchy. Return the equivalent binfo, but in the hierarchy
2317 dominated by HERE. This is the inverse of copied_binfo. If BINFO
2318 is not a base binfo of HERE, returns NULL_TREE. */
2321 original_binfo (tree binfo
, tree here
)
2325 if (BINFO_TYPE (binfo
) == BINFO_TYPE (here
))
2327 else if (BINFO_VIRTUAL_P (binfo
))
2328 result
= (CLASSTYPE_VBASECLASSES (BINFO_TYPE (here
))
2329 ? binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (here
))
2331 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2335 base_binfos
= original_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2340 base_binfos
= BINFO_BASE_BINFOS (base_binfos
);
2341 n
= TREE_VEC_LENGTH (base_binfos
);
2342 for (ix
= 0; ix
!= n
; ix
++)
2344 tree base
= TREE_VEC_ELT (base_binfos
, ix
);
2346 if (BINFO_TYPE (base
) == BINFO_TYPE (binfo
))