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 int is_subobject_of_p (tree
, tree
);
49 static tree
dfs_check_overlap (tree
, void *);
50 static tree
dfs_no_overlap_yet (tree
, int, void *);
51 static base_kind
lookup_base_r (tree
, tree
, base_access
, bool, tree
*);
52 static int dynamic_cast_base_recurse (tree
, tree
, bool, tree
*);
53 static tree
dfs_debug_unmarkedp (tree
, int, void *);
54 static tree
dfs_debug_mark (tree
, void *);
55 static int check_hidden_convs (tree
, int, int, tree
, tree
, tree
);
56 static tree
split_conversions (tree
, tree
, tree
, tree
);
57 static int lookup_conversions_r (tree
, int, int,
58 tree
, tree
, tree
, tree
, tree
*, tree
*);
59 static int look_for_overrides_r (tree
, tree
);
60 static tree
lookup_field_queue_p (tree
, int, void *);
61 static int shared_member_p (tree
);
62 static tree
lookup_field_r (tree
, void *);
63 static tree
dfs_accessible_queue_p (tree
, int, void *);
64 static tree
dfs_accessible_p (tree
, void *);
65 static tree
dfs_access_in_type (tree
, void *);
66 static access_kind
access_in_type (tree
, tree
);
67 static int protected_accessible_p (tree
, tree
, tree
);
68 static int friend_accessible_p (tree
, tree
, tree
);
69 static int template_self_reference_p (tree
, tree
);
70 static tree
dfs_get_pure_virtuals (tree
, void *);
73 /* Variables for gathering statistics. */
74 #ifdef GATHER_STATISTICS
75 static int n_fields_searched
;
76 static int n_calls_lookup_field
, n_calls_lookup_field_1
;
77 static int n_calls_lookup_fnfields
, n_calls_lookup_fnfields_1
;
78 static int n_calls_get_base_type
;
79 static int n_outer_fields_searched
;
80 static int n_contexts_saved
;
81 #endif /* GATHER_STATISTICS */
84 /* Worker for lookup_base. BINFO is the binfo we are searching at,
85 BASE is the RECORD_TYPE we are searching for. ACCESS is the
86 required access checks. IS_VIRTUAL indicates if BINFO is morally
89 If BINFO is of the required type, then *BINFO_PTR is examined to
90 compare with any other instance of BASE we might have already
91 discovered. *BINFO_PTR is initialized and a base_kind return value
92 indicates what kind of base was located.
94 Otherwise BINFO's bases are searched. */
97 lookup_base_r (tree binfo
, tree base
, base_access access
,
98 bool is_virtual
, /* inside a virtual part */
103 base_kind found
= bk_not_base
;
105 if (same_type_p (BINFO_TYPE (binfo
), base
))
107 /* We have found a base. Check against what we have found
109 found
= bk_same_type
;
111 found
= bk_via_virtual
;
115 else if (binfo
!= *binfo_ptr
)
117 if (access
!= ba_any
)
119 else if (!is_virtual
)
120 /* Prefer a non-virtual base. */
128 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
132 bk
= lookup_base_r (base_binfo
, base
,
134 is_virtual
|| BINFO_VIRTUAL_P (base_binfo
),
140 if (access
!= ba_any
)
149 gcc_assert (found
== bk_not_base
);
154 if (found
!= bk_ambig
)
168 /* Returns true if type BASE is accessible in T. (BASE is known to be
169 a (possibly non-proper) base class of T.) */
172 accessible_base_p (tree t
, tree base
)
176 /* [class.access.base]
178 A base class is said to be accessible if an invented public
179 member of the base class is accessible.
181 If BASE is a non-proper base, this condition is trivially
183 if (same_type_p (t
, base
))
185 /* Rather than inventing a public member, we use the implicit
186 public typedef created in the scope of every class. */
187 decl
= TYPE_FIELDS (base
);
188 while (!DECL_SELF_REFERENCE_P (decl
))
189 decl
= TREE_CHAIN (decl
);
190 while (ANON_AGGR_TYPE_P (t
))
191 t
= TYPE_CONTEXT (t
);
192 return accessible_p (t
, decl
);
195 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
196 ACCESS specifies. Return the binfo we discover. If KIND_PTR is
197 non-NULL, fill with information about what kind of base we
200 If the base is inaccessible, or ambiguous, and the ba_quiet bit is
201 not set in ACCESS, then an error is issued and error_mark_node is
202 returned. If the ba_quiet bit is set, then no error is issued and
203 NULL_TREE is returned. */
206 lookup_base (tree t
, tree base
, base_access access
, base_kind
*kind_ptr
)
208 tree binfo
= NULL_TREE
; /* The binfo we've found so far. */
209 tree t_binfo
= NULL_TREE
;
212 if (t
== error_mark_node
|| base
== error_mark_node
)
215 *kind_ptr
= bk_not_base
;
216 return error_mark_node
;
218 gcc_assert (TYPE_P (base
));
227 t
= complete_type (TYPE_MAIN_VARIANT (t
));
228 t_binfo
= TYPE_BINFO (t
);
231 base
= complete_type (TYPE_MAIN_VARIANT (base
));
234 bk
= lookup_base_r (t_binfo
, base
, access
, 0, &binfo
);
238 /* Check that the base is unambiguous and accessible. */
239 if (access
!= ba_any
)
247 if (!(access
& ba_quiet
))
249 error ("`%T' is an ambiguous base of `%T'", base
, t
);
250 binfo
= error_mark_node
;
255 if ((access
& ~ba_quiet
) != ba_ignore
256 /* If BASE is incomplete, then BASE and TYPE are probably
257 the same, in which case BASE is accessible. If they
258 are not the same, then TYPE is invalid. In that case,
259 there's no need to issue another error here, and
260 there's no implicit typedef to use in the code that
261 follows, so we skip the check. */
262 && COMPLETE_TYPE_P (base
)
263 && !accessible_base_p (t
, base
))
265 if (!(access
& ba_quiet
))
267 error ("`%T' is an inaccessible base of `%T'", base
, t
);
268 binfo
= error_mark_node
;
272 bk
= bk_inaccessible
;
283 /* Worker function for get_dynamic_cast_base_type. */
286 dynamic_cast_base_recurse (tree subtype
, tree binfo
, bool is_via_virtual
,
289 VEC (tree
) *accesses
;
294 if (BINFO_TYPE (binfo
) == subtype
)
300 *offset_ptr
= BINFO_OFFSET (binfo
);
305 accesses
= BINFO_BASE_ACCESSES (binfo
);
306 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
308 tree base_access
= VEC_index (tree
, accesses
, i
);
311 if (base_access
!= access_public_node
)
313 rval
= dynamic_cast_base_recurse
314 (subtype
, base_binfo
,
315 is_via_virtual
|| BINFO_VIRTUAL_P (base_binfo
), offset_ptr
);
319 worst
= worst
>= 0 ? -3 : worst
;
322 else if (rval
== -3 && worst
!= -1)
328 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
329 started from is related to the required TARGET type, in order to optimize
330 the inheritance graph search. This information is independent of the
331 current context, and ignores private paths, hence get_base_distance is
332 inappropriate. Return a TREE specifying the base offset, BOFF.
333 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
334 and there are no public virtual SUBTYPE bases.
335 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
336 BOFF == -2, SUBTYPE is not a public base.
337 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
340 get_dynamic_cast_base_type (tree subtype
, tree target
)
342 tree offset
= NULL_TREE
;
343 int boff
= dynamic_cast_base_recurse (subtype
, TYPE_BINFO (target
),
348 offset
= ssize_int (boff
);
352 /* Search for a member with name NAME in a multiple inheritance
353 lattice specified by TYPE. If it does not exist, return NULL_TREE.
354 If the member is ambiguously referenced, return `error_mark_node'.
355 Otherwise, return a DECL with the indicated name. If WANT_TYPE is
356 true, type declarations are preferred. */
358 /* Do a 1-level search for NAME as a member of TYPE. The caller must
359 figure out whether it can access this field. (Since it is only one
360 level, this is reasonable.) */
363 lookup_field_1 (tree type
, tree name
, bool want_type
)
367 if (TREE_CODE (type
) == TEMPLATE_TYPE_PARM
368 || TREE_CODE (type
) == BOUND_TEMPLATE_TEMPLATE_PARM
369 || TREE_CODE (type
) == TYPENAME_TYPE
)
370 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and
371 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all;
372 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously,
373 the code often worked even when we treated the index as a list
375 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */
379 && DECL_LANG_SPECIFIC (TYPE_NAME (type
))
380 && DECL_SORTED_FIELDS (TYPE_NAME (type
)))
382 tree
*fields
= &DECL_SORTED_FIELDS (TYPE_NAME (type
))->elts
[0];
383 int lo
= 0, hi
= DECL_SORTED_FIELDS (TYPE_NAME (type
))->len
;
390 #ifdef GATHER_STATISTICS
392 #endif /* GATHER_STATISTICS */
394 if (DECL_NAME (fields
[i
]) > name
)
396 else if (DECL_NAME (fields
[i
]) < name
)
402 /* We might have a nested class and a field with the
403 same name; we sorted them appropriately via
404 field_decl_cmp, so just look for the first or last
405 field with this name. */
410 while (i
>= lo
&& DECL_NAME (fields
[i
]) == name
);
411 if (TREE_CODE (field
) != TYPE_DECL
412 && !DECL_CLASS_TEMPLATE_P (field
))
419 while (i
< hi
&& DECL_NAME (fields
[i
]) == name
);
427 field
= TYPE_FIELDS (type
);
429 #ifdef GATHER_STATISTICS
430 n_calls_lookup_field_1
++;
431 #endif /* GATHER_STATISTICS */
432 for (field
= TYPE_FIELDS (type
); field
; field
= TREE_CHAIN (field
))
434 #ifdef GATHER_STATISTICS
436 #endif /* GATHER_STATISTICS */
437 gcc_assert (DECL_P (field
));
438 if (DECL_NAME (field
) == NULL_TREE
439 && ANON_AGGR_TYPE_P (TREE_TYPE (field
)))
441 tree temp
= lookup_field_1 (TREE_TYPE (field
), name
, want_type
);
445 if (TREE_CODE (field
) == USING_DECL
)
447 /* We generally treat class-scope using-declarations as
448 ARM-style access specifications, because support for the
449 ISO semantics has not been implemented. So, in general,
450 there's no reason to return a USING_DECL, and the rest of
451 the compiler cannot handle that. Once the class is
452 defined, USING_DECLs are purged from TYPE_FIELDS; see
453 handle_using_decl. However, we make special efforts to
454 make using-declarations in template classes work
456 if (CLASSTYPE_TEMPLATE_INFO (type
)
457 && !CLASSTYPE_USE_TEMPLATE (type
)
458 && !TREE_TYPE (field
))
464 if (DECL_NAME (field
) == name
466 || TREE_CODE (field
) == TYPE_DECL
467 || DECL_CLASS_TEMPLATE_P (field
)))
471 if (name
== vptr_identifier
)
473 /* Give the user what s/he thinks s/he wants. */
474 if (TYPE_POLYMORPHIC_P (type
))
475 return TYPE_VFIELD (type
);
480 /* There are a number of cases we need to be aware of here:
481 current_class_type current_function_decl
488 Those last two make life interesting. If we're in a function which is
489 itself inside a class, we need decls to go into the fn's decls (our
490 second case below). But if we're in a class and the class itself is
491 inside a function, we need decls to go into the decls for the class. To
492 achieve this last goal, we must see if, when both current_class_ptr and
493 current_function_decl are set, the class was declared inside that
494 function. If so, we know to put the decls into the class's scope. */
499 if (current_function_decl
== NULL_TREE
)
500 return current_class_type
;
501 if (current_class_type
== NULL_TREE
)
502 return current_function_decl
;
503 if ((DECL_FUNCTION_MEMBER_P (current_function_decl
)
504 && same_type_p (DECL_CONTEXT (current_function_decl
),
506 || (DECL_FRIEND_CONTEXT (current_function_decl
)
507 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl
),
508 current_class_type
)))
509 return current_function_decl
;
511 return current_class_type
;
514 /* Returns nonzero if we are currently in a function scope. Note
515 that this function returns zero if we are within a local class, but
516 not within a member function body of the local class. */
519 at_function_scope_p (void)
521 tree cs
= current_scope ();
522 return cs
&& TREE_CODE (cs
) == FUNCTION_DECL
;
525 /* Returns true if the innermost active scope is a class scope. */
528 at_class_scope_p (void)
530 tree cs
= current_scope ();
531 return cs
&& TYPE_P (cs
);
534 /* Returns true if the innermost active scope is a namespace scope. */
537 at_namespace_scope_p (void)
539 /* We are in a namespace scope if we are not it a class scope or a
541 return !current_scope();
544 /* Return the scope of DECL, as appropriate when doing name-lookup. */
547 context_for_name_lookup (tree decl
)
551 For the purposes of name lookup, after the anonymous union
552 definition, the members of the anonymous union are considered to
553 have been defined in the scope in which the anonymous union is
555 tree context
= DECL_CONTEXT (decl
);
557 while (context
&& TYPE_P (context
) && ANON_AGGR_TYPE_P (context
))
558 context
= TYPE_CONTEXT (context
);
560 context
= global_namespace
;
565 /* The accessibility routines use BINFO_ACCESS for scratch space
566 during the computation of the accessibility of some declaration. */
568 #define BINFO_ACCESS(NODE) \
569 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE)))
571 /* Set the access associated with NODE to ACCESS. */
573 #define SET_BINFO_ACCESS(NODE, ACCESS) \
574 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \
575 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0))
577 /* Called from access_in_type via dfs_walk. Calculate the access to
578 DATA (which is really a DECL) in BINFO. */
581 dfs_access_in_type (tree binfo
, void *data
)
583 tree decl
= (tree
) data
;
584 tree type
= BINFO_TYPE (binfo
);
585 access_kind access
= ak_none
;
587 if (context_for_name_lookup (decl
) == type
)
589 /* If we have descended to the scope of DECL, just note the
590 appropriate access. */
591 if (TREE_PRIVATE (decl
))
593 else if (TREE_PROTECTED (decl
))
594 access
= ak_protected
;
600 /* First, check for an access-declaration that gives us more
601 access to the DECL. The CONST_DECL for an enumeration
602 constant will not have DECL_LANG_SPECIFIC, and thus no
604 if (DECL_LANG_SPECIFIC (decl
) && !DECL_DISCRIMINATOR_P (decl
))
606 tree decl_access
= purpose_member (type
, DECL_ACCESS (decl
));
610 decl_access
= TREE_VALUE (decl_access
);
612 if (decl_access
== access_public_node
)
614 else if (decl_access
== access_protected_node
)
615 access
= ak_protected
;
616 else if (decl_access
== access_private_node
)
627 VEC (tree
) *accesses
;
629 /* Otherwise, scan our baseclasses, and pick the most favorable
631 accesses
= BINFO_BASE_ACCESSES (binfo
);
632 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
634 tree base_access
= VEC_index (tree
, accesses
, i
);
635 access_kind base_access_now
= BINFO_ACCESS (base_binfo
);
637 if (base_access_now
== ak_none
|| base_access_now
== ak_private
)
638 /* If it was not accessible in the base, or only
639 accessible as a private member, we can't access it
641 base_access_now
= ak_none
;
642 else if (base_access
== access_protected_node
)
643 /* Public and protected members in the base become
645 base_access_now
= ak_protected
;
646 else if (base_access
== access_private_node
)
647 /* Public and protected members in the base become
649 base_access_now
= ak_private
;
651 /* See if the new access, via this base, gives more
652 access than our previous best access. */
653 if (base_access_now
!= ak_none
654 && (access
== ak_none
|| base_access_now
< access
))
656 access
= base_access_now
;
658 /* If the new access is public, we can't do better. */
659 if (access
== ak_public
)
666 /* Note the access to DECL in TYPE. */
667 SET_BINFO_ACCESS (binfo
, access
);
669 /* Mark TYPE as visited so that if we reach it again we do not
670 duplicate our efforts here. */
671 BINFO_MARKED (binfo
) = 1;
676 /* Return the access to DECL in TYPE. */
679 access_in_type (tree type
, tree decl
)
681 tree binfo
= TYPE_BINFO (type
);
683 /* We must take into account
687 If a name can be reached by several paths through a multiple
688 inheritance graph, the access is that of the path that gives
691 The algorithm we use is to make a post-order depth-first traversal
692 of the base-class hierarchy. As we come up the tree, we annotate
693 each node with the most lenient access. */
694 dfs_walk_real (binfo
, 0, dfs_access_in_type
, unmarkedp
, decl
);
695 dfs_walk (binfo
, dfs_unmark
, markedp
, 0);
697 return BINFO_ACCESS (binfo
);
700 /* Called from accessible_p via dfs_walk. */
703 dfs_accessible_queue_p (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
705 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
707 if (BINFO_MARKED (binfo
))
710 /* If this class is inherited via private or protected inheritance,
711 then we can't see it, unless we are a friend of the derived class. */
712 if (BINFO_BASE_ACCESS (derived
, ix
) != access_public_node
713 && !is_friend (BINFO_TYPE (derived
), current_scope ()))
719 /* Called from accessible_p via dfs_walk. */
722 dfs_accessible_p (tree binfo
, void *data ATTRIBUTE_UNUSED
)
726 BINFO_MARKED (binfo
) = 1;
727 access
= BINFO_ACCESS (binfo
);
728 if (access
!= ak_none
729 && is_friend (BINFO_TYPE (binfo
), current_scope ()))
735 /* Returns nonzero if it is OK to access DECL through an object
736 indicated by BINFO in the context of DERIVED. */
739 protected_accessible_p (tree decl
, tree derived
, tree binfo
)
743 /* We're checking this clause from [class.access.base]
745 m as a member of N is protected, and the reference occurs in a
746 member or friend of class N, or in a member or friend of a
747 class P derived from N, where m as a member of P is private or
750 Here DERIVED is a possible P and DECL is m. accessible_p will
751 iterate over various values of N, but the access to m in DERIVED
754 Note that I believe that the passage above is wrong, and should read
755 "...is private or protected or public"; otherwise you get bizarre results
756 whereby a public using-decl can prevent you from accessing a protected
757 member of a base. (jason 2000/02/28) */
759 /* If DERIVED isn't derived from m's class, then it can't be a P. */
760 if (!DERIVED_FROM_P (context_for_name_lookup (decl
), derived
))
763 access
= access_in_type (derived
, decl
);
765 /* If m is inaccessible in DERIVED, then it's not a P. */
766 if (access
== ak_none
)
771 When a friend or a member function of a derived class references
772 a protected nonstatic member of a base class, an access check
773 applies in addition to those described earlier in clause
774 _class.access_) Except when forming a pointer to member
775 (_expr.unary.op_), the access must be through a pointer to,
776 reference to, or object of the derived class itself (or any class
777 derived from that class) (_expr.ref_). If the access is to form
778 a pointer to member, the nested-name-specifier shall name the
779 derived class (or any class derived from that class). */
780 if (DECL_NONSTATIC_MEMBER_P (decl
))
782 /* We can tell through what the reference is occurring by
783 chasing BINFO up to the root. */
785 while (BINFO_INHERITANCE_CHAIN (t
))
786 t
= BINFO_INHERITANCE_CHAIN (t
);
788 if (!DERIVED_FROM_P (derived
, BINFO_TYPE (t
)))
795 /* Returns nonzero if SCOPE is a friend of a type which would be able
796 to access DECL through the object indicated by BINFO. */
799 friend_accessible_p (tree scope
, tree decl
, tree binfo
)
801 tree befriending_classes
;
807 if (TREE_CODE (scope
) == FUNCTION_DECL
808 || DECL_FUNCTION_TEMPLATE_P (scope
))
809 befriending_classes
= DECL_BEFRIENDING_CLASSES (scope
);
810 else if (TYPE_P (scope
))
811 befriending_classes
= CLASSTYPE_BEFRIENDING_CLASSES (scope
);
815 for (t
= befriending_classes
; t
; t
= TREE_CHAIN (t
))
816 if (protected_accessible_p (decl
, TREE_VALUE (t
), binfo
))
819 /* Nested classes are implicitly friends of their enclosing types, as
820 per core issue 45 (this is a change from the standard). */
822 for (t
= TYPE_CONTEXT (scope
); t
&& TYPE_P (t
); t
= TYPE_CONTEXT (t
))
823 if (protected_accessible_p (decl
, t
, binfo
))
826 if (TREE_CODE (scope
) == FUNCTION_DECL
827 || DECL_FUNCTION_TEMPLATE_P (scope
))
829 /* Perhaps this SCOPE is a member of a class which is a
831 if (DECL_CLASS_SCOPE_P (decl
)
832 && friend_accessible_p (DECL_CONTEXT (scope
), decl
, binfo
))
835 /* Or an instantiation of something which is a friend. */
836 if (DECL_TEMPLATE_INFO (scope
))
839 /* Increment processing_template_decl to make sure that
840 dependent_type_p works correctly. */
841 ++processing_template_decl
;
842 ret
= friend_accessible_p (DECL_TI_TEMPLATE (scope
), decl
, binfo
);
843 --processing_template_decl
;
847 else if (CLASSTYPE_TEMPLATE_INFO (scope
))
850 /* Increment processing_template_decl to make sure that
851 dependent_type_p works correctly. */
852 ++processing_template_decl
;
853 ret
= friend_accessible_p (CLASSTYPE_TI_TEMPLATE (scope
), decl
, binfo
);
854 --processing_template_decl
;
861 /* DECL is a declaration from a base class of TYPE, which was the
862 class used to name DECL. Return nonzero if, in the current
863 context, DECL is accessible. If TYPE is actually a BINFO node,
864 then we can tell in what context the access is occurring by looking
865 at the most derived class along the path indicated by BINFO. */
868 accessible_p (tree type
, tree decl
)
875 /* Nonzero if it's OK to access DECL if it has protected
876 accessibility in TYPE. */
877 int protected_ok
= 0;
879 /* If this declaration is in a block or namespace scope, there's no
881 if (!TYPE_P (context_for_name_lookup (decl
)))
884 /* There is no need to perform access checks inside a thunk. */
885 scope
= current_scope ();
886 if (scope
&& DECL_THUNK_P (scope
))
889 /* In a template declaration, we cannot be sure whether the
890 particular specialization that is instantiated will be a friend
891 or not. Therefore, all access checks are deferred until
893 if (processing_template_decl
)
899 type
= BINFO_TYPE (type
);
902 binfo
= TYPE_BINFO (type
);
904 /* [class.access.base]
906 A member m is accessible when named in class N if
908 --m as a member of N is public, or
910 --m as a member of N is private, and the reference occurs in a
911 member or friend of class N, or
913 --m as a member of N is protected, and the reference occurs in a
914 member or friend of class N, or in a member or friend of a
915 class P derived from N, where m as a member of P is private or
918 --there exists a base class B of N that is accessible at the point
919 of reference, and m is accessible when named in class B.
921 We walk the base class hierarchy, checking these conditions. */
923 /* Figure out where the reference is occurring. Check to see if
924 DECL is private or protected in this scope, since that will
925 determine whether protected access is allowed. */
926 if (current_class_type
)
927 protected_ok
= protected_accessible_p (decl
, current_class_type
, binfo
);
929 /* Now, loop through the classes of which we are a friend. */
931 protected_ok
= friend_accessible_p (scope
, decl
, binfo
);
933 /* Standardize the binfo that access_in_type will use. We don't
934 need to know what path was chosen from this point onwards. */
935 binfo
= TYPE_BINFO (type
);
937 /* Compute the accessibility of DECL in the class hierarchy
938 dominated by type. */
939 access
= access_in_type (type
, decl
);
940 if (access
== ak_public
941 || (access
== ak_protected
&& protected_ok
))
945 /* Walk the hierarchy again, looking for a base class that allows
947 t
= dfs_walk (binfo
, dfs_accessible_p
, dfs_accessible_queue_p
, 0);
948 /* Clear any mark bits. Note that we have to walk the whole tree
949 here, since we have aborted the previous walk from some point
951 dfs_walk (binfo
, dfs_unmark
, 0, 0);
953 return t
!= NULL_TREE
;
957 struct lookup_field_info
{
958 /* The type in which we're looking. */
960 /* The name of the field for which we're looking. */
962 /* If non-NULL, the current result of the lookup. */
964 /* The path to RVAL. */
966 /* If non-NULL, the lookup was ambiguous, and this is a list of the
969 /* If nonzero, we are looking for types, not data members. */
971 /* If something went wrong, a message indicating what. */
975 /* Returns nonzero if BINFO is not hidden by the value found by the
976 lookup so far. If BINFO is hidden, then there's no need to look in
977 it. DATA is really a struct lookup_field_info. Called from
978 lookup_field via breadth_first_search. */
981 lookup_field_queue_p (tree derived
, int ix
, void *data
)
983 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
984 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
986 /* Don't look for constructors or destructors in base classes. */
987 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi
->name
))
990 /* If this base class is hidden by the best-known value so far, we
991 don't need to look. */
992 if (lfi
->rval_binfo
&& derived
== lfi
->rval_binfo
)
995 /* If this is a dependent base, don't look in it. */
996 if (BINFO_DEPENDENT_BASE_P (binfo
))
1002 /* Within the scope of a template class, you can refer to the to the
1003 current specialization with the name of the template itself. For
1006 template <typename T> struct S { S* sp; }
1008 Returns nonzero if DECL is such a declaration in a class TYPE. */
1011 template_self_reference_p (tree type
, tree decl
)
1013 return (CLASSTYPE_USE_TEMPLATE (type
)
1014 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type
))
1015 && TREE_CODE (decl
) == TYPE_DECL
1016 && DECL_ARTIFICIAL (decl
)
1017 && DECL_NAME (decl
) == constructor_name (type
));
1020 /* Nonzero for a class member means that it is shared between all objects
1023 [class.member.lookup]:If the resulting set of declarations are not all
1024 from sub-objects of the same type, or the set has a nonstatic member
1025 and includes members from distinct sub-objects, there is an ambiguity
1026 and the program is ill-formed.
1028 This function checks that T contains no nonstatic members. */
1031 shared_member_p (tree t
)
1033 if (TREE_CODE (t
) == VAR_DECL
|| TREE_CODE (t
) == TYPE_DECL \
1034 || TREE_CODE (t
) == CONST_DECL
)
1036 if (is_overloaded_fn (t
))
1038 for (; t
; t
= OVL_NEXT (t
))
1040 tree fn
= OVL_CURRENT (t
);
1041 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn
))
1049 /* Routine to see if the sub-object denoted by the binfo PARENT can be
1050 found as a base class and sub-object of the object denoted by
1054 is_subobject_of_p (tree parent
, tree binfo
)
1058 for (probe
= parent
; probe
; probe
= BINFO_INHERITANCE_CHAIN (probe
))
1062 if (BINFO_VIRTUAL_P (probe
))
1063 return (binfo_for_vbase (BINFO_TYPE (probe
), BINFO_TYPE (binfo
))
1069 /* DATA is really a struct lookup_field_info. Look for a field with
1070 the name indicated there in BINFO. If this function returns a
1071 non-NULL value it is the result of the lookup. Called from
1072 lookup_field via breadth_first_search. */
1075 lookup_field_r (tree binfo
, void *data
)
1077 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
1078 tree type
= BINFO_TYPE (binfo
);
1079 tree nval
= NULL_TREE
;
1081 /* First, look for a function. There can't be a function and a data
1082 member with the same name, and if there's a function and a type
1083 with the same name, the type is hidden by the function. */
1084 if (!lfi
->want_type
)
1086 int idx
= lookup_fnfields_1 (type
, lfi
->name
);
1088 nval
= VEC_index (tree
, CLASSTYPE_METHOD_VEC (type
), idx
);
1092 /* Look for a data member or type. */
1093 nval
= lookup_field_1 (type
, lfi
->name
, lfi
->want_type
);
1095 /* If there is no declaration with the indicated name in this type,
1096 then there's nothing to do. */
1100 /* If we're looking up a type (as with an elaborated type specifier)
1101 we ignore all non-types we find. */
1102 if (lfi
->want_type
&& TREE_CODE (nval
) != TYPE_DECL
1103 && !DECL_CLASS_TEMPLATE_P (nval
))
1105 if (lfi
->name
== TYPE_IDENTIFIER (type
))
1107 /* If the aggregate has no user defined constructors, we allow
1108 it to have fields with the same name as the enclosing type.
1109 If we are looking for that name, find the corresponding
1111 for (nval
= TREE_CHAIN (nval
); nval
; nval
= TREE_CHAIN (nval
))
1112 if (DECL_NAME (nval
) == lfi
->name
1113 && TREE_CODE (nval
) == TYPE_DECL
)
1118 if (!nval
&& CLASSTYPE_NESTED_UTDS (type
) != NULL
)
1120 binding_entry e
= binding_table_find (CLASSTYPE_NESTED_UTDS (type
),
1123 nval
= TYPE_MAIN_DECL (e
->type
);
1129 /* You must name a template base class with a template-id. */
1130 if (!same_type_p (type
, lfi
->type
)
1131 && template_self_reference_p (type
, nval
))
1134 /* If the lookup already found a match, and the new value doesn't
1135 hide the old one, we might have an ambiguity. */
1137 && !is_subobject_of_p (lfi
->rval_binfo
, binfo
))
1140 if (nval
== lfi
->rval
&& shared_member_p (nval
))
1141 /* The two things are really the same. */
1143 else if (is_subobject_of_p (binfo
, lfi
->rval_binfo
))
1144 /* The previous value hides the new one. */
1148 /* We have a real ambiguity. We keep a chain of all the
1150 if (!lfi
->ambiguous
&& lfi
->rval
)
1152 /* This is the first time we noticed an ambiguity. Add
1153 what we previously thought was a reasonable candidate
1155 lfi
->ambiguous
= tree_cons (NULL_TREE
, lfi
->rval
, NULL_TREE
);
1156 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1159 /* Add the new value. */
1160 lfi
->ambiguous
= tree_cons (NULL_TREE
, nval
, lfi
->ambiguous
);
1161 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1162 lfi
->errstr
= "request for member `%D' is ambiguous";
1168 lfi
->rval_binfo
= binfo
;
1174 /* Return a "baselink" with BASELINK_BINFO, BASELINK_ACCESS_BINFO,
1175 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO,
1176 FUNCTIONS, and OPTYPE respectively. */
1179 build_baselink (tree binfo
, tree access_binfo
, tree functions
, tree optype
)
1183 gcc_assert (TREE_CODE (functions
) == FUNCTION_DECL
1184 || TREE_CODE (functions
) == TEMPLATE_DECL
1185 || TREE_CODE (functions
) == TEMPLATE_ID_EXPR
1186 || TREE_CODE (functions
) == OVERLOAD
);
1187 gcc_assert (!optype
|| TYPE_P (optype
));
1188 gcc_assert (TREE_TYPE (functions
));
1190 baselink
= make_node (BASELINK
);
1191 TREE_TYPE (baselink
) = TREE_TYPE (functions
);
1192 BASELINK_BINFO (baselink
) = binfo
;
1193 BASELINK_ACCESS_BINFO (baselink
) = access_binfo
;
1194 BASELINK_FUNCTIONS (baselink
) = functions
;
1195 BASELINK_OPTYPE (baselink
) = optype
;
1200 /* Look for a member named NAME in an inheritance lattice dominated by
1201 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it
1202 is 1, we enforce accessibility. If PROTECT is zero, then, for an
1203 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error
1204 messages about inaccessible or ambiguous lookup. If PROTECT is 2,
1205 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose
1206 TREE_VALUEs are the list of ambiguous candidates.
1208 WANT_TYPE is 1 when we should only return TYPE_DECLs.
1210 If nothing can be found return NULL_TREE and do not issue an error. */
1213 lookup_member (tree xbasetype
, tree name
, int protect
, bool want_type
)
1215 tree rval
, rval_binfo
= NULL_TREE
;
1216 tree type
= NULL_TREE
, basetype_path
= NULL_TREE
;
1217 struct lookup_field_info lfi
;
1219 /* rval_binfo is the binfo associated with the found member, note,
1220 this can be set with useful information, even when rval is not
1221 set, because it must deal with ALL members, not just non-function
1222 members. It is used for ambiguity checking and the hidden
1223 checks. Whereas rval is only set if a proper (not hidden)
1224 non-function member is found. */
1226 const char *errstr
= 0;
1228 gcc_assert (TREE_CODE (name
) == IDENTIFIER_NODE
);
1230 if (TREE_CODE (xbasetype
) == TREE_BINFO
)
1232 type
= BINFO_TYPE (xbasetype
);
1233 basetype_path
= xbasetype
;
1237 gcc_assert (IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype
)));
1239 xbasetype
= NULL_TREE
;
1242 type
= complete_type (type
);
1244 basetype_path
= TYPE_BINFO (type
);
1249 #ifdef GATHER_STATISTICS
1250 n_calls_lookup_field
++;
1251 #endif /* GATHER_STATISTICS */
1253 memset (&lfi
, 0, sizeof (lfi
));
1256 lfi
.want_type
= want_type
;
1257 dfs_walk_real (basetype_path
, &lookup_field_r
, 0,
1258 &lookup_field_queue_p
, &lfi
);
1260 rval_binfo
= lfi
.rval_binfo
;
1262 type
= BINFO_TYPE (rval_binfo
);
1263 errstr
= lfi
.errstr
;
1265 /* If we are not interested in ambiguities, don't report them;
1266 just return NULL_TREE. */
1267 if (!protect
&& lfi
.ambiguous
)
1273 return lfi
.ambiguous
;
1280 In the case of overloaded function names, access control is
1281 applied to the function selected by overloaded resolution. */
1282 if (rval
&& protect
&& !is_overloaded_fn (rval
))
1283 perform_or_defer_access_check (basetype_path
, rval
);
1285 if (errstr
&& protect
)
1287 error (errstr
, name
, type
);
1289 print_candidates (lfi
.ambiguous
);
1290 rval
= error_mark_node
;
1293 if (rval
&& is_overloaded_fn (rval
))
1294 rval
= build_baselink (rval_binfo
, basetype_path
, rval
,
1295 (IDENTIFIER_TYPENAME_P (name
)
1296 ? TREE_TYPE (name
): NULL_TREE
));
1300 /* Like lookup_member, except that if we find a function member we
1301 return NULL_TREE. */
1304 lookup_field (tree xbasetype
, tree name
, int protect
, bool want_type
)
1306 tree rval
= lookup_member (xbasetype
, name
, protect
, want_type
);
1308 /* Ignore functions, but propagate the ambiguity list. */
1309 if (!error_operand_p (rval
)
1310 && (rval
&& BASELINK_P (rval
)))
1316 /* Like lookup_member, except that if we find a non-function member we
1317 return NULL_TREE. */
1320 lookup_fnfields (tree xbasetype
, tree name
, int protect
)
1322 tree rval
= lookup_member (xbasetype
, name
, protect
, /*want_type=*/false);
1324 /* Ignore non-functions, but propagate the ambiguity list. */
1325 if (!error_operand_p (rval
)
1326 && (rval
&& !BASELINK_P (rval
)))
1332 /* Return the index in the CLASSTYPE_METHOD_VEC for CLASS_TYPE
1333 corresponding to "operator TYPE ()", or -1 if there is no such
1334 operator. Only CLASS_TYPE itself is searched; this routine does
1335 not scan the base classes of CLASS_TYPE. */
1338 lookup_conversion_operator (tree class_type
, tree type
)
1342 if (TYPE_HAS_CONVERSION (class_type
))
1346 VEC(tree
) *methods
= CLASSTYPE_METHOD_VEC (class_type
);
1348 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
1349 VEC_iterate (tree
, methods
, i
, fn
); ++i
)
1351 /* All the conversion operators come near the beginning of
1352 the class. Therefore, if FN is not a conversion
1353 operator, there is no matching conversion operator in
1355 fn
= OVL_CURRENT (fn
);
1356 if (!DECL_CONV_FN_P (fn
))
1359 if (TREE_CODE (fn
) == TEMPLATE_DECL
)
1360 /* All the templated conversion functions are on the same
1361 slot, so remember it. */
1363 else if (same_type_p (DECL_CONV_FN_TYPE (fn
), type
))
1371 /* TYPE is a class type. Return the index of the fields within
1372 the method vector with name NAME, or -1 is no such field exists. */
1375 lookup_fnfields_1 (tree type
, tree name
)
1377 VEC(tree
) *method_vec
;
1382 if (!CLASS_TYPE_P (type
))
1385 if (COMPLETE_TYPE_P (type
))
1387 if ((name
== ctor_identifier
1388 || name
== base_ctor_identifier
1389 || name
== complete_ctor_identifier
))
1391 if (CLASSTYPE_LAZY_DEFAULT_CTOR (type
))
1392 lazily_declare_fn (sfk_constructor
, type
);
1393 if (CLASSTYPE_LAZY_COPY_CTOR (type
))
1394 lazily_declare_fn (sfk_copy_constructor
, type
);
1396 else if (name
== ansi_assopname(NOP_EXPR
)
1397 && CLASSTYPE_LAZY_ASSIGNMENT_OP (type
))
1398 lazily_declare_fn (sfk_assignment_operator
, type
);
1401 method_vec
= CLASSTYPE_METHOD_VEC (type
);
1405 #ifdef GATHER_STATISTICS
1406 n_calls_lookup_fnfields_1
++;
1407 #endif /* GATHER_STATISTICS */
1409 /* Constructors are first... */
1410 if (name
== ctor_identifier
)
1412 fn
= CLASSTYPE_CONSTRUCTORS (type
);
1413 return fn
? CLASSTYPE_CONSTRUCTOR_SLOT
: -1;
1415 /* and destructors are second. */
1416 if (name
== dtor_identifier
)
1418 fn
= CLASSTYPE_DESTRUCTORS (type
);
1419 return fn
? CLASSTYPE_DESTRUCTOR_SLOT
: -1;
1421 if (IDENTIFIER_TYPENAME_P (name
))
1422 return lookup_conversion_operator (type
, TREE_TYPE (name
));
1424 /* Skip the conversion operators. */
1425 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
1426 VEC_iterate (tree
, method_vec
, i
, fn
);
1428 if (!DECL_CONV_FN_P (OVL_CURRENT (fn
)))
1431 /* If the type is complete, use binary search. */
1432 if (COMPLETE_TYPE_P (type
))
1438 hi
= VEC_length (tree
, method_vec
);
1443 #ifdef GATHER_STATISTICS
1444 n_outer_fields_searched
++;
1445 #endif /* GATHER_STATISTICS */
1447 tmp
= VEC_index (tree
, method_vec
, i
);
1448 tmp
= DECL_NAME (OVL_CURRENT (tmp
));
1451 else if (tmp
< name
)
1458 for (; VEC_iterate (tree
, method_vec
, i
, fn
); ++i
)
1460 #ifdef GATHER_STATISTICS
1461 n_outer_fields_searched
++;
1462 #endif /* GATHER_STATISTICS */
1463 if (DECL_NAME (OVL_CURRENT (fn
)) == name
)
1470 /* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is
1471 the class or namespace used to qualify the name. CONTEXT_CLASS is
1472 the class corresponding to the object in which DECL will be used.
1473 Return a possibly modified version of DECL that takes into account
1476 In particular, consider an expression like `B::m' in the context of
1477 a derived class `D'. If `B::m' has been resolved to a BASELINK,
1478 then the most derived class indicated by the BASELINK_BINFO will be
1479 `B', not `D'. This function makes that adjustment. */
1482 adjust_result_of_qualified_name_lookup (tree decl
,
1483 tree qualifying_scope
,
1486 if (context_class
&& CLASS_TYPE_P (qualifying_scope
)
1487 && DERIVED_FROM_P (qualifying_scope
, context_class
)
1488 && BASELINK_P (decl
))
1492 gcc_assert (CLASS_TYPE_P (context_class
));
1494 /* Look for the QUALIFYING_SCOPE as a base of the CONTEXT_CLASS.
1495 Because we do not yet know which function will be chosen by
1496 overload resolution, we cannot yet check either accessibility
1497 or ambiguity -- in either case, the choice of a static member
1498 function might make the usage valid. */
1499 base
= lookup_base (context_class
, qualifying_scope
,
1500 ba_ignore
| ba_quiet
, NULL
);
1503 BASELINK_ACCESS_BINFO (decl
) = base
;
1504 BASELINK_BINFO (decl
)
1505 = lookup_base (base
, BINFO_TYPE (BASELINK_BINFO (decl
)),
1506 ba_ignore
| ba_quiet
,
1515 /* Walk the class hierarchy within BINFO, in a depth-first traversal.
1516 PREFN is called in preorder, while POSTFN is called in postorder.
1517 If they ever returns a non-NULL value, that value is immediately
1518 returned and the walk is terminated. Both PREFN and POSTFN can be
1519 NULL. At each node, PREFN and POSTFN are passed the binfo to
1520 examine. Before each base-binfo of BINFO is walked, QFN is called.
1521 If the value returned is nonzero, the base-binfo is walked;
1522 otherwise it is not. If QFN is NULL, it is treated as a function
1523 which always returns 1. All callbacks are passed DATA whenever
1527 dfs_walk_real (tree binfo
,
1528 tree (*prefn
) (tree
, void *),
1529 tree (*postfn
) (tree
, void *),
1530 tree (*qfn
) (tree
, int, void *),
1535 tree rval
= NULL_TREE
;
1537 /* Call the pre-order walking function. */
1540 rval
= (*prefn
) (binfo
, data
);
1545 /* Process the basetypes. */
1546 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1550 base_binfo
= (*qfn
) (binfo
, i
, data
);
1554 rval
= dfs_walk_real (base_binfo
, prefn
, postfn
, qfn
, data
);
1559 /* Call the post-order walking function. */
1561 rval
= (*postfn
) (binfo
, data
);
1566 /* Exactly like dfs_walk_real, except that there is no pre-order
1567 function call and FN is called in post-order. */
1570 dfs_walk (tree binfo
,
1571 tree (*fn
) (tree
, void *),
1572 tree (*qfn
) (tree
, int, void *),
1575 return dfs_walk_real (binfo
, 0, fn
, qfn
, data
);
1578 /* Check that virtual overrider OVERRIDER is acceptable for base function
1579 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
1582 check_final_overrider (tree overrider
, tree basefn
)
1584 tree over_type
= TREE_TYPE (overrider
);
1585 tree base_type
= TREE_TYPE (basefn
);
1586 tree over_return
= TREE_TYPE (over_type
);
1587 tree base_return
= TREE_TYPE (base_type
);
1588 tree over_throw
= TYPE_RAISES_EXCEPTIONS (over_type
);
1589 tree base_throw
= TYPE_RAISES_EXCEPTIONS (base_type
);
1592 if (DECL_INVALID_OVERRIDER_P (overrider
))
1595 if (same_type_p (base_return
, over_return
))
1597 else if ((CLASS_TYPE_P (over_return
) && CLASS_TYPE_P (base_return
))
1598 || (TREE_CODE (base_return
) == TREE_CODE (over_return
)
1599 && POINTER_TYPE_P (base_return
)))
1601 /* Potentially covariant. */
1602 unsigned base_quals
, over_quals
;
1604 fail
= !POINTER_TYPE_P (base_return
);
1607 fail
= cp_type_quals (base_return
) != cp_type_quals (over_return
);
1609 base_return
= TREE_TYPE (base_return
);
1610 over_return
= TREE_TYPE (over_return
);
1612 base_quals
= cp_type_quals (base_return
);
1613 over_quals
= cp_type_quals (over_return
);
1615 if ((base_quals
& over_quals
) != over_quals
)
1618 if (CLASS_TYPE_P (base_return
) && CLASS_TYPE_P (over_return
))
1620 tree binfo
= lookup_base (over_return
, base_return
,
1621 ba_check
| ba_quiet
, NULL
);
1627 && can_convert (TREE_TYPE (base_type
), TREE_TYPE (over_type
)))
1628 /* GNU extension, allow trivial pointer conversions such as
1629 converting to void *, or qualification conversion. */
1631 /* can_convert will permit user defined conversion from a
1632 (reference to) class type. We must reject them. */
1633 over_return
= non_reference (TREE_TYPE (over_type
));
1634 if (CLASS_TYPE_P (over_return
))
1648 cp_error_at ("invalid covariant return type for `%#D'", overrider
);
1649 cp_error_at (" overriding `%#D'", basefn
);
1653 cp_error_at ("conflicting return type specified for `%#D'",
1655 cp_error_at (" overriding `%#D'", basefn
);
1657 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1661 /* Check throw specifier is at least as strict. */
1662 if (!comp_except_specs (base_throw
, over_throw
, 0))
1664 cp_error_at ("looser throw specifier for `%#F'", overrider
);
1665 cp_error_at (" overriding `%#F'", basefn
);
1666 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1673 /* Given a class TYPE, and a function decl FNDECL, look for
1674 virtual functions in TYPE's hierarchy which FNDECL overrides.
1675 We do not look in TYPE itself, only its bases.
1677 Returns nonzero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
1678 find that it overrides anything.
1680 We check that every function which is overridden, is correctly
1684 look_for_overrides (tree type
, tree fndecl
)
1686 tree binfo
= TYPE_BINFO (type
);
1691 for (ix
= 0; BINFO_BASE_ITERATE (binfo
, ix
, base_binfo
); ix
++)
1693 tree basetype
= BINFO_TYPE (base_binfo
);
1695 if (TYPE_POLYMORPHIC_P (basetype
))
1696 found
+= look_for_overrides_r (basetype
, fndecl
);
1701 /* Look in TYPE for virtual functions with the same signature as
1705 look_for_overrides_here (tree type
, tree fndecl
)
1709 /* If there are no methods in TYPE (meaning that only implicitly
1710 declared methods will ever be provided for TYPE), then there are
1711 no virtual functions. */
1712 if (!CLASSTYPE_METHOD_VEC (type
))
1715 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl
))
1716 ix
= CLASSTYPE_DESTRUCTOR_SLOT
;
1718 ix
= lookup_fnfields_1 (type
, DECL_NAME (fndecl
));
1721 tree fns
= VEC_index (tree
, CLASSTYPE_METHOD_VEC (type
), ix
);
1723 for (; fns
; fns
= OVL_NEXT (fns
))
1725 tree fn
= OVL_CURRENT (fns
);
1727 if (!DECL_VIRTUAL_P (fn
))
1728 /* Not a virtual. */;
1729 else if (DECL_CONTEXT (fn
) != type
)
1730 /* Introduced with a using declaration. */;
1731 else if (DECL_STATIC_FUNCTION_P (fndecl
))
1733 tree btypes
= TYPE_ARG_TYPES (TREE_TYPE (fn
));
1734 tree dtypes
= TYPE_ARG_TYPES (TREE_TYPE (fndecl
));
1735 if (compparms (TREE_CHAIN (btypes
), dtypes
))
1738 else if (same_signature_p (fndecl
, fn
))
1745 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
1746 TYPE itself and its bases. */
1749 look_for_overrides_r (tree type
, tree fndecl
)
1751 tree fn
= look_for_overrides_here (type
, fndecl
);
1754 if (DECL_STATIC_FUNCTION_P (fndecl
))
1756 /* A static member function cannot match an inherited
1757 virtual member function. */
1758 cp_error_at ("`%#D' cannot be declared", fndecl
);
1759 cp_error_at (" since `%#D' declared in base class", fn
);
1763 /* It's definitely virtual, even if not explicitly set. */
1764 DECL_VIRTUAL_P (fndecl
) = 1;
1765 check_final_overrider (fndecl
, fn
);
1770 /* We failed to find one declared in this class. Look in its bases. */
1771 return look_for_overrides (type
, fndecl
);
1774 /* Called via dfs_walk from dfs_get_pure_virtuals. */
1777 dfs_get_pure_virtuals (tree binfo
, void *data
)
1779 tree type
= (tree
) data
;
1781 /* We're not interested in primary base classes; the derived class
1782 of which they are a primary base will contain the information we
1784 if (!BINFO_PRIMARY_P (binfo
))
1788 for (virtuals
= BINFO_VIRTUALS (binfo
);
1790 virtuals
= TREE_CHAIN (virtuals
))
1791 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals
)))
1792 VEC_safe_push (tree
, CLASSTYPE_PURE_VIRTUALS (type
),
1796 BINFO_MARKED (binfo
) = 1;
1801 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
1804 get_pure_virtuals (tree type
)
1806 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
1807 is going to be overridden. */
1808 CLASSTYPE_PURE_VIRTUALS (type
) = NULL
;
1809 /* Now, run through all the bases which are not primary bases, and
1810 collect the pure virtual functions. We look at the vtable in
1811 each class to determine what pure virtual functions are present.
1812 (A primary base is not interesting because the derived class of
1813 which it is a primary base will contain vtable entries for the
1814 pure virtuals in the base class. */
1815 dfs_walk (TYPE_BINFO (type
), dfs_get_pure_virtuals
, unmarkedp
, type
);
1816 dfs_walk (TYPE_BINFO (type
), dfs_unmark
, markedp
, type
);
1819 /* DEPTH-FIRST SEARCH ROUTINES. */
1822 markedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1824 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1826 return BINFO_MARKED (binfo
) ? binfo
: NULL_TREE
;
1830 unmarkedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1832 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1834 return !BINFO_MARKED (binfo
) ? binfo
: NULL_TREE
;
1837 /* The worker functions for `dfs_walk'. These do not need to
1838 test anything (vis a vis marking) if they are paired with
1839 a predicate function (above). */
1842 dfs_unmark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
1844 BINFO_MARKED (binfo
) = 0;
1849 /* Debug info for C++ classes can get very large; try to avoid
1850 emitting it everywhere.
1852 Note that this optimization wins even when the target supports
1853 BINCL (if only slightly), and reduces the amount of work for the
1857 maybe_suppress_debug_info (tree t
)
1859 if (write_symbols
== NO_DEBUG
)
1862 /* We might have set this earlier in cp_finish_decl. */
1863 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 0;
1865 /* If we already know how we're handling this class, handle debug info
1867 if (CLASSTYPE_INTERFACE_KNOWN (t
))
1869 if (CLASSTYPE_INTERFACE_ONLY (t
))
1870 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
1871 /* else don't set it. */
1873 /* If the class has a vtable, write out the debug info along with
1875 else if (TYPE_CONTAINS_VPTR_P (t
))
1876 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
1878 /* Otherwise, just emit the debug info normally. */
1881 /* Note that we want debugging information for a base class of a class
1882 whose vtable is being emitted. Normally, this would happen because
1883 calling the constructor for a derived class implies calling the
1884 constructors for all bases, which involve initializing the
1885 appropriate vptr with the vtable for the base class; but in the
1886 presence of optimization, this initialization may be optimized
1887 away, so we tell finish_vtable_vardecl that we want the debugging
1888 information anyway. */
1891 dfs_debug_mark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
1893 tree t
= BINFO_TYPE (binfo
);
1895 CLASSTYPE_DEBUG_REQUESTED (t
) = 1;
1900 /* Returns BINFO if we haven't already noted that we want debugging
1901 info for this base class. */
1904 dfs_debug_unmarkedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1906 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1908 return (!CLASSTYPE_DEBUG_REQUESTED (BINFO_TYPE (binfo
))
1909 ? binfo
: NULL_TREE
);
1912 /* Write out the debugging information for TYPE, whose vtable is being
1913 emitted. Also walk through our bases and note that we want to
1914 write out information for them. This avoids the problem of not
1915 writing any debug info for intermediate basetypes whose
1916 constructors, and thus the references to their vtables, and thus
1917 the vtables themselves, were optimized away. */
1920 note_debug_info_needed (tree type
)
1922 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)))
1924 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)) = 0;
1925 rest_of_type_compilation (type
, toplevel_bindings_p ());
1928 dfs_walk (TYPE_BINFO (type
), dfs_debug_mark
, dfs_debug_unmarkedp
, 0);
1932 print_search_statistics (void)
1934 #ifdef GATHER_STATISTICS
1935 fprintf (stderr
, "%d fields searched in %d[%d] calls to lookup_field[_1]\n",
1936 n_fields_searched
, n_calls_lookup_field
, n_calls_lookup_field_1
);
1937 fprintf (stderr
, "%d fnfields searched in %d calls to lookup_fnfields\n",
1938 n_outer_fields_searched
, n_calls_lookup_fnfields
);
1939 fprintf (stderr
, "%d calls to get_base_type\n", n_calls_get_base_type
);
1940 #else /* GATHER_STATISTICS */
1941 fprintf (stderr
, "no search statistics\n");
1942 #endif /* GATHER_STATISTICS */
1946 reinit_search_statistics (void)
1948 #ifdef GATHER_STATISTICS
1949 n_fields_searched
= 0;
1950 n_calls_lookup_field
= 0, n_calls_lookup_field_1
= 0;
1951 n_calls_lookup_fnfields
= 0, n_calls_lookup_fnfields_1
= 0;
1952 n_calls_get_base_type
= 0;
1953 n_outer_fields_searched
= 0;
1954 n_contexts_saved
= 0;
1955 #endif /* GATHER_STATISTICS */
1958 /* Helper for lookup_conversions_r. TO_TYPE is the type converted to
1959 by a conversion op in base BINFO. VIRTUAL_DEPTH is nonzero if
1960 BINFO is morally virtual, and VIRTUALNESS is nonzero if virtual
1961 bases have been encountered already in the tree walk. PARENT_CONVS
1962 is the list of lists of conversion functions that could hide CONV
1963 and OTHER_CONVS is the list of lists of conversion functions that
1964 could hide or be hidden by CONV, should virtualness be involved in
1965 the hierarchy. Merely checking the conversion op's name is not
1966 enough because two conversion operators to the same type can have
1967 different names. Return nonzero if we are visible. */
1970 check_hidden_convs (tree binfo
, int virtual_depth
, int virtualness
,
1971 tree to_type
, tree parent_convs
, tree other_convs
)
1975 /* See if we are hidden by a parent conversion. */
1976 for (level
= parent_convs
; level
; level
= TREE_CHAIN (level
))
1977 for (probe
= TREE_VALUE (level
); probe
; probe
= TREE_CHAIN (probe
))
1978 if (same_type_p (to_type
, TREE_TYPE (probe
)))
1981 if (virtual_depth
|| virtualness
)
1983 /* In a virtual hierarchy, we could be hidden, or could hide a
1984 conversion function on the other_convs list. */
1985 for (level
= other_convs
; level
; level
= TREE_CHAIN (level
))
1991 if (!(virtual_depth
|| TREE_STATIC (level
)))
1992 /* Neither is morally virtual, so cannot hide each other. */
1995 if (!TREE_VALUE (level
))
1996 /* They evaporated away already. */
1999 they_hide_us
= (virtual_depth
2000 && original_binfo (binfo
, TREE_PURPOSE (level
)));
2001 we_hide_them
= (!they_hide_us
&& TREE_STATIC (level
)
2002 && original_binfo (TREE_PURPOSE (level
), binfo
));
2004 if (!(we_hide_them
|| they_hide_us
))
2005 /* Neither is within the other, so no hiding can occur. */
2008 for (prev
= &TREE_VALUE (level
), other
= *prev
; other
;)
2010 if (same_type_p (to_type
, TREE_TYPE (other
)))
2013 /* We are hidden. */
2018 /* We hide the other one. */
2019 other
= TREE_CHAIN (other
);
2024 prev
= &TREE_CHAIN (other
);
2032 /* Helper for lookup_conversions_r. PARENT_CONVS is a list of lists
2033 of conversion functions, the first slot will be for the current
2034 binfo, if MY_CONVS is non-NULL. CHILD_CONVS is the list of lists
2035 of conversion functions from children of the current binfo,
2036 concatenated with conversions from elsewhere in the hierarchy --
2037 that list begins with OTHER_CONVS. Return a single list of lists
2038 containing only conversions from the current binfo and its
2042 split_conversions (tree my_convs
, tree parent_convs
,
2043 tree child_convs
, tree other_convs
)
2048 /* Remove the original other_convs portion from child_convs. */
2049 for (prev
= NULL
, t
= child_convs
;
2050 t
!= other_convs
; prev
= t
, t
= TREE_CHAIN (t
))
2054 TREE_CHAIN (prev
) = NULL_TREE
;
2056 child_convs
= NULL_TREE
;
2058 /* Attach the child convs to any we had at this level. */
2061 my_convs
= parent_convs
;
2062 TREE_CHAIN (my_convs
) = child_convs
;
2065 my_convs
= child_convs
;
2070 /* Worker for lookup_conversions. Lookup conversion functions in
2071 BINFO and its children. VIRTUAL_DEPTH is nonzero, if BINFO is in
2072 a morally virtual base, and VIRTUALNESS is nonzero, if we've
2073 encountered virtual bases already in the tree walk. PARENT_CONVS &
2074 PARENT_TPL_CONVS are lists of list of conversions within parent
2075 binfos. OTHER_CONVS and OTHER_TPL_CONVS are conversions found
2076 elsewhere in the tree. Return the conversions found within this
2077 portion of the graph in CONVS and TPL_CONVS. Return nonzero is we
2078 encountered virtualness. We keep template and non-template
2079 conversions separate, to avoid unnecessary type comparisons.
2081 The located conversion functions are held in lists of lists. The
2082 TREE_VALUE of the outer list is the list of conversion functions
2083 found in a particular binfo. The TREE_PURPOSE of both the outer
2084 and inner lists is the binfo at which those conversions were
2085 found. TREE_STATIC is set for those lists within of morally
2086 virtual binfos. The TREE_VALUE of the inner list is the conversion
2087 function or overload itself. The TREE_TYPE of each inner list node
2088 is the converted-to type. */
2091 lookup_conversions_r (tree binfo
,
2092 int virtual_depth
, int virtualness
,
2093 tree parent_convs
, tree parent_tpl_convs
,
2094 tree other_convs
, tree other_tpl_convs
,
2095 tree
*convs
, tree
*tpl_convs
)
2097 int my_virtualness
= 0;
2098 tree my_convs
= NULL_TREE
;
2099 tree my_tpl_convs
= NULL_TREE
;
2100 tree child_convs
= NULL_TREE
;
2101 tree child_tpl_convs
= NULL_TREE
;
2104 VEC(tree
) *method_vec
= CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo
));
2107 /* If we have no conversion operators, then don't look. */
2108 if (!TYPE_HAS_CONVERSION (BINFO_TYPE (binfo
)))
2110 *convs
= *tpl_convs
= NULL_TREE
;
2115 if (BINFO_VIRTUAL_P (binfo
))
2118 /* First, locate the unhidden ones at this level. */
2119 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
2120 VEC_iterate (tree
, method_vec
, i
, conv
);
2123 tree cur
= OVL_CURRENT (conv
);
2125 if (!DECL_CONV_FN_P (cur
))
2128 if (TREE_CODE (cur
) == TEMPLATE_DECL
)
2130 /* Only template conversions can be overloaded, and we must
2131 flatten them out and check each one individually. */
2134 for (tpls
= conv
; tpls
; tpls
= OVL_NEXT (tpls
))
2136 tree tpl
= OVL_CURRENT (tpls
);
2137 tree type
= DECL_CONV_FN_TYPE (tpl
);
2139 if (check_hidden_convs (binfo
, virtual_depth
, virtualness
,
2140 type
, parent_tpl_convs
, other_tpl_convs
))
2142 my_tpl_convs
= tree_cons (binfo
, tpl
, my_tpl_convs
);
2143 TREE_TYPE (my_tpl_convs
) = type
;
2146 TREE_STATIC (my_tpl_convs
) = 1;
2154 tree name
= DECL_NAME (cur
);
2156 if (!IDENTIFIER_MARKED (name
))
2158 tree type
= DECL_CONV_FN_TYPE (cur
);
2160 if (check_hidden_convs (binfo
, virtual_depth
, virtualness
,
2161 type
, parent_convs
, other_convs
))
2163 my_convs
= tree_cons (binfo
, conv
, my_convs
);
2164 TREE_TYPE (my_convs
) = type
;
2167 TREE_STATIC (my_convs
) = 1;
2170 IDENTIFIER_MARKED (name
) = 1;
2178 parent_convs
= tree_cons (binfo
, my_convs
, parent_convs
);
2180 TREE_STATIC (parent_convs
) = 1;
2185 parent_tpl_convs
= tree_cons (binfo
, my_tpl_convs
, parent_tpl_convs
);
2187 TREE_STATIC (parent_convs
) = 1;
2190 child_convs
= other_convs
;
2191 child_tpl_convs
= other_tpl_convs
;
2193 /* Now iterate over each base, looking for more conversions. */
2194 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
2196 tree base_convs
, base_tpl_convs
;
2197 unsigned base_virtualness
;
2199 base_virtualness
= lookup_conversions_r (base_binfo
,
2200 virtual_depth
, virtualness
,
2201 parent_convs
, parent_tpl_convs
,
2202 child_convs
, child_tpl_convs
,
2203 &base_convs
, &base_tpl_convs
);
2204 if (base_virtualness
)
2205 my_virtualness
= virtualness
= 1;
2206 child_convs
= chainon (base_convs
, child_convs
);
2207 child_tpl_convs
= chainon (base_tpl_convs
, child_tpl_convs
);
2210 /* Unmark the conversions found at this level */
2211 for (conv
= my_convs
; conv
; conv
= TREE_CHAIN (conv
))
2212 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (conv
)))) = 0;
2214 *convs
= split_conversions (my_convs
, parent_convs
,
2215 child_convs
, other_convs
);
2216 *tpl_convs
= split_conversions (my_tpl_convs
, parent_tpl_convs
,
2217 child_tpl_convs
, other_tpl_convs
);
2219 return my_virtualness
;
2222 /* Return a TREE_LIST containing all the non-hidden user-defined
2223 conversion functions for TYPE (and its base-classes). The
2224 TREE_VALUE of each node is the FUNCTION_DECL of the conversion
2225 function. The TREE_PURPOSE is the BINFO from which the conversion
2226 functions in this node were selected. This function is effectively
2227 performing a set of member lookups as lookup_fnfield does, but
2228 using the type being converted to as the unique key, rather than the
2232 lookup_conversions (tree type
)
2234 tree convs
, tpl_convs
;
2235 tree list
= NULL_TREE
;
2237 complete_type (type
);
2238 if (!TYPE_BINFO (type
))
2241 lookup_conversions_r (TYPE_BINFO (type
), 0, 0,
2242 NULL_TREE
, NULL_TREE
, NULL_TREE
, NULL_TREE
,
2243 &convs
, &tpl_convs
);
2245 /* Flatten the list-of-lists */
2246 for (; convs
; convs
= TREE_CHAIN (convs
))
2250 for (probe
= TREE_VALUE (convs
); probe
; probe
= next
)
2252 next
= TREE_CHAIN (probe
);
2254 TREE_CHAIN (probe
) = list
;
2259 for (; tpl_convs
; tpl_convs
= TREE_CHAIN (tpl_convs
))
2263 for (probe
= TREE_VALUE (tpl_convs
); probe
; probe
= next
)
2265 next
= TREE_CHAIN (probe
);
2267 TREE_CHAIN (probe
) = list
;
2281 /* Check whether the empty class indicated by EMPTY_BINFO is also present
2282 at offset 0 in COMPARE_TYPE, and set found_overlap if so. */
2285 dfs_check_overlap (tree empty_binfo
, void *data
)
2287 struct overlap_info
*oi
= (struct overlap_info
*) data
;
2290 for (binfo
= TYPE_BINFO (oi
->compare_type
);
2292 binfo
= BINFO_BASE_BINFO (binfo
, 0))
2294 if (BINFO_TYPE (binfo
) == BINFO_TYPE (empty_binfo
))
2296 oi
->found_overlap
= 1;
2299 else if (!BINFO_N_BASE_BINFOS (binfo
))
2306 /* Trivial function to stop base traversal when we find something. */
2309 dfs_no_overlap_yet (tree derived
, int ix
, void *data
)
2311 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
2312 struct overlap_info
*oi
= (struct overlap_info
*) data
;
2314 return !oi
->found_overlap
? binfo
: NULL_TREE
;
2317 /* Returns nonzero if EMPTY_TYPE or any of its bases can also be found at
2318 offset 0 in NEXT_TYPE. Used in laying out empty base class subobjects. */
2321 types_overlap_p (tree empty_type
, tree next_type
)
2323 struct overlap_info oi
;
2325 if (! IS_AGGR_TYPE (next_type
))
2327 oi
.compare_type
= next_type
;
2328 oi
.found_overlap
= 0;
2329 dfs_walk (TYPE_BINFO (empty_type
), dfs_check_overlap
,
2330 dfs_no_overlap_yet
, &oi
);
2331 return oi
.found_overlap
;
2334 /* Returns the binfo of the first direct or indirect virtual base derived
2335 from BINFO, or NULL if binfo is not via virtual. */
2338 binfo_from_vbase (tree binfo
)
2340 for (; binfo
; binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2342 if (BINFO_VIRTUAL_P (binfo
))
2348 /* Returns the binfo of the first direct or indirect virtual base derived
2349 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
2353 binfo_via_virtual (tree binfo
, tree limit
)
2355 for (; binfo
&& (!limit
|| !same_type_p (BINFO_TYPE (binfo
), limit
));
2356 binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2358 if (BINFO_VIRTUAL_P (binfo
))
2364 /* BINFO is a base binfo in the complete type BINFO_TYPE (HERE).
2365 Find the equivalent binfo within whatever graph HERE is located.
2366 This is the inverse of original_binfo. */
2369 copied_binfo (tree binfo
, tree here
)
2371 tree result
= NULL_TREE
;
2373 if (BINFO_VIRTUAL_P (binfo
))
2377 for (t
= here
; BINFO_INHERITANCE_CHAIN (t
);
2378 t
= BINFO_INHERITANCE_CHAIN (t
))
2381 result
= binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (t
));
2383 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2389 cbinfo
= copied_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2390 for (ix
= 0; BINFO_BASE_ITERATE (cbinfo
, ix
, base_binfo
); ix
++)
2391 if (BINFO_TYPE (base_binfo
) == BINFO_TYPE (binfo
))
2393 result
= base_binfo
;
2399 gcc_assert (BINFO_TYPE (here
) == BINFO_TYPE (binfo
));
2403 gcc_assert (result
);
2408 binfo_for_vbase (tree base
, tree t
)
2414 for (vbases
= CLASSTYPE_VBASECLASSES (t
), ix
= 0;
2415 VEC_iterate (tree
, vbases
, ix
, binfo
); ix
++)
2416 if (BINFO_TYPE (binfo
) == base
)
2421 /* BINFO is some base binfo of HERE, within some other
2422 hierarchy. Return the equivalent binfo, but in the hierarchy
2423 dominated by HERE. This is the inverse of copied_binfo. If BINFO
2424 is not a base binfo of HERE, returns NULL_TREE. */
2427 original_binfo (tree binfo
, tree here
)
2431 if (BINFO_TYPE (binfo
) == BINFO_TYPE (here
))
2433 else if (BINFO_VIRTUAL_P (binfo
))
2434 result
= (CLASSTYPE_VBASECLASSES (BINFO_TYPE (here
))
2435 ? binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (here
))
2437 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2441 base_binfos
= original_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2447 for (ix
= 0; (base_binfo
= BINFO_BASE_BINFO (base_binfos
, ix
)); ix
++)
2448 if (BINFO_TYPE (base_binfo
) == BINFO_TYPE (binfo
))
2450 result
= base_binfo
;