| blob | 5716ee5e3f32062f8bec3eb62c4a0a6b544e72e4 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001 Free Software Foundation, Inc.
4 Contributed by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GNU CC.
8 GNU CC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
13 GNU CC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU CC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 /* High-level class interface. */
38 #define obstack_chunk_alloc xmalloc
39 #define obstack_chunk_free free
41 /* The number of nested classes being processed. If we are not in the
42 scope of any class, this is zero. */
46 /* In order to deal with nested classes, we keep a stack of classes.
47 The topmost entry is the innermost class, and is the entry at index
48 CURRENT_CLASS_DEPTH */
51 /* The name of the class. */
52 tree name;
54 /* The _TYPE node for the class. */
55 tree type;
57 /* The access specifier pending for new declarations in the scope of
58 this class. */
59 tree access;
61 /* If were defining TYPE, the names used in this class. */
62 splay_tree names_used;
66 {
67 /* The base for which we're building initializers. */
68 tree binfo;
69 /* The type of the most-derived type. */
70 tree derived;
71 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
72 unless ctor_vtbl_p is true. */
73 tree rtti_binfo;
74 /* The negative-index vtable initializers built up so far. These
75 are in order from least negative index to most negative index. */
76 tree inits;
77 /* The last (i.e., most negative) entry in INITS. */
79 /* The binfo for the virtual base for which we're building
80 vcall offset initializers. */
81 tree vbase;
82 /* The functions in vbase for which we have already provided vcall
83 offsets. */
84 varray_type fns;
85 /* The vtable index of the next vcall or vbase offset. */
86 tree index;
87 /* Nonzero if we are building the initializer for the primary
88 vtable. */
90 /* Nonzero if we are building the initializer for a construction
91 vtable. */
95 /* The type of a function passed to walk_subobject_offsets. */
98 /* The stack itself. This is an dynamically resized array. The
99 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
103 /* An array of all local classes present in this translation unit, in
104 declaration order. */
105 varray_type local_classes;
185 tree));
189 vtbl_init_data *));
215 splay_tree_key k2));
220 /* Macros for dfs walking during vtt construction. See
221 dfs_ctor_vtable_bases_queue_p, dfs_build_secondary_vptr_vtt_inits
222 and dfs_fixup_binfo_vtbls. */
223 #define VTT_TOP_LEVEL_P(node) TREE_UNSIGNED(node)
224 #define VTT_MARKED_BINFO_P(node) TREE_USED(node)
226 /* Variables shared between class.c and call.c. */
228 #ifdef GATHER_STATISTICS
237 #endif
239 /* Virtual base class layout. */
241 /* Returns a pointer to the virtual base class of EXP that has the
242 indicated TYPE. EXP is of class type, not a pointer type. */
244 static tree
247 {
248 tree vbase;
249 tree vbase_ptr;
251 /* Find the shared copy of TYPE; that's where the vtable offset is
252 recorded. */
254 /* Find the virtual function table pointer. */
256 /* Compute the location where the offset will lie. */
259 vbase_ptr,
263 vbase_ptr);
264 /* Add the contents of this location to EXP. */
269 }
271 /* Build multi-level access to EXPR using hierarchy path PATH.
272 CODE is PLUS_EXPR if we are going with the grain,
273 and MINUS_EXPR if we are not (in which case, we cannot traverse
274 virtual baseclass links).
276 TYPE is the type we want this path to have on exit.
278 NONNULL is non-zero if we know (for any reason) that EXPR is
279 not, in fact, zero. */
281 tree
286 {
291 tree basetype;
297 /* We could do better if we had additional logic to convert back to the
298 unconverted type (the static type of the complete object), and then
299 convert back to the type we want. Until that is done, we only optimize
300 if the complete type is the same type as expr has. */
303 /* Virtual base layout is not fixed, even in ctors and dtors. */
315 {
317 {
320 {
324 {
325 tree ind;
327 /* We already check for ambiguous things in the caller, just
328 find a path. */
330 {
333 }
339 {
343 integer_zero_node),
345 }
346 }
347 /* else we'll figure out the offset below. */
349 /* Happens in the case of parse errors. */
352 }
353 else
354 {
356 last_virtual);
358 }
359 }
362 }
363 /* LAST is now the last basetype assoc on the path. */
365 /* A pointer to a virtual base member of a non-null object
366 is non-null. Therefore, we only need to test for zeroness once.
367 Make EXPR the canonical expression to deal with here. */
369 {
373 }
374 else
377 /* If we go through any virtual base pointers, make sure that
378 casts to BASETYPE from the last virtual base class use
379 the right value for BASETYPE. */
381 {
385 offset
387 }
388 else
392 {
393 /* Bash types to make the backend happy. */
396 /* If expr might be 0, we need to preserve that zeroness. */
398 {
401 else
408 null_expr,
410 }
412 }
414 /* Cannot change the TREE_TYPE of a NOP_EXPR here, since it may
415 be used multiple times in initialization of multiple inheritance. */
417 {
420 }
421 else
423 }
425 \f
426 /* Virtual function things. */
428 /* We want to give the assembler the vtable identifier as well as
429 the offset to the function pointer. So we generate
431 __asm__ __volatile__ (".vtable_entry %c0, %c1"
432 : : "s"(&class_vtable),
433 "i"((long)&vtbl[idx].pfn - (long)&vtbl[0])); */
435 static void
438 {
457 }
459 /* Given an object INSTANCE, return an expression which yields the
460 virtual function vtable element corresponding to INDEX. There are
461 many special cases for INSTANCE which we take care of here, mainly
462 to avoid creating extra tree nodes when we don't have to. */
464 tree
467 {
476 else
477 {
479 {
480 /* Try to figure out what a reference refers to, and
481 access its virtual function table directly. */
492 {
499 {
505 }
506 }
507 }
513 {
515 /* Knowing the dynamic type of INSTANCE we can easily obtain
516 the correct vtable entry. We resolve this back to be in
517 terms of the primary vtable. */
519 {
522 idx,
528 }
529 }
530 else
532 }
542 }
544 /* Given an object INSTANCE, return an expression which yields the
545 virtual function corresponding to IDX. */
547 tree
549 tree instance;
550 tree idx;
551 {
555 }
557 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
558 for the given TYPE. */
560 static tree
562 tree type;
563 {
565 }
567 /* Return an IDENTIFIER_NODE for the name of the virtual table table
568 for TYPE. */
570 tree
572 tree type;
573 {
575 }
577 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
578 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
579 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
581 static tree
583 tree class_type;
584 tree name;
585 tree vtable_type;
586 {
587 tree decl;
590 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
591 now to avoid confusion in mangle_decl. */
601 }
603 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
604 or even complete. If this does not exist, create it. If COMPLETE is
605 non-zero, then complete the definition of it -- that will render it
606 impossible to actually build the vtable, but is useful to get at those
607 which are known to exist in the runtime. */
609 tree
611 tree type;
613 {
618 {
622 }
629 /* At one time the vtable info was grabbed 2 words at a time. This
630 fails on sparc unless you have 8-byte alignment. (tiemann) */
635 {
638 }
641 }
643 /* Returns a copy of the BINFO_VIRTUALS list in BINFO. The
644 BV_VCALL_INDEX for each entry is cleared. */
646 static tree
648 tree binfo;
649 {
650 tree copies;
651 tree t;
655 {
658 }
661 }
663 /* Build the primary virtual function table for TYPE. If BINFO is
664 non-NULL, build the vtable starting with the initial approximation
665 that it is the same as the one which is the head of the association
666 list. Returns a non-zero value if a new vtable is actually
667 created. */
669 static int
672 {
673 tree decl;
674 tree virtuals;
679 {
681 /* We have already created a vtable for this base, so there's
682 no need to do it again. */
689 }
690 else
691 {
695 }
697 #ifdef GATHER_STATISTICS
700 #endif
702 /* Initialize the association list for this type, based
703 on our first approximation. */
708 }
710 /* Give BINFO a new virtual function table which is initialized
711 with a skeleton-copy of its original initialization. The only
712 entry that changes is the `delta' entry, so we can really
713 share a lot of structure.
715 FOR_TYPE is the most derived type which caused this table to
716 be needed.
718 Returns non-zero if we haven't met BINFO before.
720 The order in which vtables are built (by calling this function) for
721 an object must remain the same, otherwise a binary incompatibility
722 can result. */
724 static int
727 {
731 /* We already created a vtable for this base. There's no need to
732 do it again. */
735 /* Remember that we've created a vtable for this BINFO, so that we
736 don't try to do so again. */
739 /* Make fresh virtual list, so we can smash it later. */
742 /* Secondary vtables are laid out as part of the same structure as
743 the primary vtable. */
746 }
748 /* Create a new vtable for BINFO which is the hierarchy dominated by
749 T. Return non-zero if we actually created a new vtable. */
751 static int
753 tree t;
754 tree binfo;
755 {
757 /* In this case, it is *type*'s vtable we are modifying. We start
758 with the approximation that its vtable is that of the
759 immediate base class. */
760 /* ??? This actually passes TYPE_BINFO (t), not the primary base binfo,
761 since we've updated DECL_CONTEXT (TYPE_VFIELD (t)) by now. */
763 t);
764 else
765 /* This is our very own copy of `basetype' to play with. Later,
766 we will fill in all the virtual functions that override the
767 virtual functions in these base classes which are not defined
768 by the current type. */
770 }
772 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
773 (which is in the hierarchy dominated by T) list FNDECL as its
774 BV_FN. DELTA is the required constant adjustment from the `this'
775 pointer where the vtable entry appears to the `this' required when
776 the function is actually called. */
778 static void
780 tree t;
781 tree binfo;
782 tree fndecl;
783 tree delta;
785 {
786 tree v;
792 {
793 tree base_fndecl;
795 /* We need a new vtable for BINFO. */
797 {
798 /* If we really did make a new vtable, we also made a copy
799 of the BINFO_VIRTUALS list. Now, we have to find the
800 corresponding entry in that list. */
805 }
812 /* Now assign virtual dispatch information, if unset. We can
813 dispatch this through any overridden base function.
815 FIXME this can choose a secondary vtable if the primary is not
816 also lexically first, leading to useless conversions.
817 In the V3 ABI, there's no reason for DECL_VIRTUAL_CONTEXT to
818 ever be different from DECL_CONTEXT. */
820 {
823 }
824 }
825 }
827 /* Set DECL_VINDEX for DECL. VINDEX_P is the number of virtual
828 functions present in the vtable so far. */
830 static void
832 tree decl;
834 {
839 }
841 /* Add a virtual function to all the appropriate vtables for the class
842 T. DECL_VINDEX(X) should be error_mark_node, if we want to
843 allocate a new slot in our table. If it is error_mark_node, we
844 know that no other function from another vtable is overridden by X.
845 VFUNS_P keeps track of how many virtuals there are in our
846 main vtable for the type, and we build upon the NEW_VIRTUALS list
847 and return it. */
849 static void
855 tree fndecl;
857 {
858 tree new_virtual;
860 /* If this function doesn't override anything from a base class, we
861 can just assign it a new DECL_VINDEX now. Otherwise, if it does
862 override something, we keep it around and assign its DECL_VINDEX
863 later, in modify_all_vtables. */
865 /* We've already dealt with this function. */
873 {
874 /* FNDECL is a new virtual function; it doesn't override any
875 virtual function in a base class. */
877 /* We remember that this was the base sub-object for rtti. */
880 /* Now assign virtual dispatch information. */
884 /* Save the state we've computed on the NEW_VIRTUALS list. */
887 }
888 else
889 {
890 /* FNDECL overrides a function from a base class. */
893 }
894 }
895 \f
896 /* Add method METHOD to class TYPE. If ERROR_P is true, we are adding
897 the method after the class has already been defined because a
898 declaration for it was seen. (Even though that is erroneous, we
899 add the method for improved error recovery.) */
901 void
903 tree type;
904 tree method;
906 {
910 tree method_vec;
913 /* Make a new method vector. We start with 8 entries. We must
914 allocate at least two (for constructors and destructors), and
915 we're going to end up with an assignment operator at some point
916 as well.
918 We could use a TREE_LIST for now, and convert it to a TREE_VEC
919 in finish_struct, but we would probably waste more memory
920 making the links in the list than we would by over-allocating
921 the size of the vector here. Furthermore, we would complicate
922 all the code that expects this to be a vector. */
928 /* Constructors and destructors go in special slots. */
933 else
934 {
935 /* See if we already have an entry with this name. */
939 slot)))
944 {
945 /* We need a bigger method vector. */
947 tree new_vec;
949 /* In the non-error case, we are processing a class
950 definition. Double the size of the vector to give room
951 for new methods. */
954 /* In the error case, the vector is already complete. We
955 don't expect many errors, and the rest of the front-end
956 will get confused if there are empty slots in the vector. */
957 else
965 }
968 {
969 /* Type conversion operators have to come before ordinary
970 methods; add_conversions depends on this to speed up
971 looking for conversion operators. So, if necessary, we
972 slide some of the vector elements up. In theory, this
973 makes this algorithm O(N^2) but we don't expect many
974 conversion operators. */
976 {
980 /* There are no more entries in the vector, so we
981 can insert the new conversion operator here. */
985 /* We can insert the new function right at the
986 SLOTth position. */
988 }
991 /* There is nothing in the Ith slot, so we can avoid
992 moving anything. */
993 ;
994 else
995 {
996 /* We know the last slot in the vector is empty
997 because we know that at this point there's room
998 for a new function. */
1003 }
1004 }
1005 }
1008 /* TYPE is a template class. Don't issue any errors now; wait
1009 until instantiation time to complain. */
1010 ;
1011 else
1012 {
1013 tree fns;
1015 /* Check to see if we've already got this method. */
1017 fns;
1019 {
1026 {
1027 /* [over.load] Member function declarations with the
1028 same name and the same parameter types cannot be
1029 overloaded if any of them is a static member
1030 function declaration. */
1034 {
1044 {
1046 /* Defer to the local function. */
1048 else
1051 }
1052 }
1053 }
1058 /* There has already been a declaration of this method
1059 or member template. */
1063 /* We don't call duplicate_decls here to merge the
1064 declarations because that will confuse things if the
1065 methods have inline definitions. In particular, we
1066 will crash while processing the definitions. */
1068 }
1069 }
1071 /* Actually insert the new method. */
1075 /* Add the new binding. */
1080 }
1082 /* Subroutines of finish_struct. */
1084 /* Look through the list of fields for this struct, deleting
1085 duplicates as we go. This must be recursive to handle
1086 anonymous unions.
1088 FIELD is the field which may not appear anywhere in FIELDS.
1089 FIELD_PTR, if non-null, is the starting point at which
1090 chained deletions may take place.
1091 The value returned is the first acceptable entry found
1092 in FIELDS.
1094 Note that anonymous fields which are not of UNION_TYPE are
1095 not duplicates, they are just anonymous fields. This happens
1096 when we have unnamed bitfields, for example. */
1098 static tree
1101 {
1102 tree x;
1105 {
1112 }
1113 else
1114 {
1116 {
1118 {
1124 {
1127 else
1129 }
1130 }
1132 /* A using declaration may is allowed to appear more than
1133 once. We'll prune these from the field list later, and
1134 handle_using_decl will complain about invalid multiple
1135 uses. */
1136 ;
1138 {
1145 x);
1148 {
1152 }
1155 {
1156 /* Hide tag decls. */
1163 x);
1164 }
1165 else
1169 else
1171 }
1172 }
1173 }
1175 }
1177 static void
1179 tree fields;
1180 {
1181 tree x;
1184 }
1186 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1187 legit, otherwise return 0. */
1189 static int
1191 tree t;
1192 tree fdecl;
1193 tree access;
1194 {
1195 tree elem;
1205 {
1207 {
1210 else
1213 }
1214 else
1215 {
1216 /* They're changing the access to the same thing they changed
1217 it to before. That's OK. */
1218 ;
1219 }
1220 }
1221 else
1222 {
1226 }
1228 }
1230 /* Process the USING_DECL, which is a member of T. */
1232 static void
1234 tree using_decl;
1235 tree t;
1236 {
1239 tree access
1245 tree old_value;
1252 {
1255 }
1257 {
1260 }
1265 {
1268 }
1271 /* Ignore base type this came from. */
1276 {
1282 else
1284 }
1290 ;
1292 {
1294 /* It's OK to use functions from a base when there are functions with
1296 else
1297 {
1302 }
1303 }
1305 {
1309 }
1311 /* Make type T see field decl FDECL with access ACCESS.*/
1314 {
1317 }
1318 else
1320 }
1321 \f
1322 /* Run through the base clases of T, updating
1323 CANT_HAVE_DEFAULT_CTOR_P, CANT_HAVE_CONST_CTOR_P, and
1324 NO_CONST_ASN_REF_P. Also set flag bits in T based on properties of
1325 the bases. */
1327 static void
1329 no_const_asn_ref_p)
1330 tree t;
1334 {
1338 tree binfos;
1344 /* An aggregate cannot have baseclasses. */
1348 {
1349 tree base_binfo;
1350 tree basetype;
1352 /* Figure out what base we're looking at. */
1356 /* If the type of basetype is incomplete, then we already
1357 complained about that fact (and we should have fixed it up as
1358 well). */
1360 {
1362 /* The base type is of incomplete type. It is
1363 probably best to pretend that it does not
1364 exist. */
1372 }
1374 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1375 here because the case of virtual functions but non-virtual
1376 dtor is handled in finish_struct_1. */
1379 basetype);
1381 /* If the base class doesn't have copy constructors or
1382 assignment operators that take const references, then the
1383 derived class cannot have such a member automatically
1384 generated. */
1390 /* Similarly, if the base class doesn't have a default
1391 constructor, then the derived class won't have an
1392 automatically generated default constructor. */
1395 {
1399 basetype);
1400 }
1403 /* A virtual base does not effect nearly emptiness. */
1404 ;
1406 {
1408 /* And if there is more than one nearly empty base, then the
1409 derived class is not nearly empty either. */
1411 else
1412 /* Remember we've seen one. */
1414 }
1416 /* If the base class is not empty or nearly empty, then this
1417 class cannot be nearly empty. */
1420 /* A lot of properties from the bases also apply to the derived
1421 class. */
1432 }
1433 }
1435 /* Binfo FROM is within a virtual heirarchy which is being reseated to
1436 TO. Move primary information from FROM to TO, and recursively traverse
1437 into FROM's bases. The heirarchy is dominated by TYPE. MAPPINGS is an
1438 assoc list of binfos that have already been reseated. */
1440 static void
1442 tree to;
1443 tree from;
1444 tree type;
1445 tree mappings;
1446 {
1457 {
1459 tree assoc;
1461 /* We might have just moved the primary base too, see if it's on our
1462 mappings. */
1468 }
1473 {
1478 {
1481 /* This base is a primary of some binfo we have already
1482 reseated. We must reseat this one too. */
1484 }
1485 else
1487 }
1488 }
1490 /* FROM is the canonical binfo for a virtual base. It is being reseated to
1491 make TO the canonical binfo, within the heirarchy dominated by TYPE.
1492 MAPPINGS is an assoc list of binfos that have already been reseated.
1493 Adjust any non-virtual bases within FROM, and also move any virtual bases
1494 which are canonical. This complication arises because selecting primary
1495 bases walks in inheritance graph order, but we don't share binfos for
1496 virtual bases, hence we can fill in the primaries for a virtual base,
1497 and then discover that a later base requires the virtual as its
1498 primary. */
1500 static void
1502 tree to;
1503 tree from;
1504 tree type;
1505 tree mappings;
1506 {
1511 }
1513 /* Make BASE_BINFO the primary virtual base of BINFO within the hierarchy
1514 dominated by TYPE. Returns BASE_BINFO, if it can be made so, NULL
1515 otherwise (because something else has already made it primary). */
1517 static tree
1519 tree binfo;
1520 tree base_binfo;
1521 tree type;
1522 {
1526 {
1527 /* It's already allocated in the hierarchy. BINFO won't have a
1528 primary base in this hierachy, even though the complete object
1529 BINFO is for, would do. */
1533 }
1535 /* We need to make sure that the assoc list
1536 CLASSTYPE_VBASECLASSES of TYPE, indicates this particular
1537 primary BINFO for the virtual base, as this is the one
1538 that'll really exist. */
1543 }
1545 /* If BINFO is an unmarked virtual binfo for a class with a primary virtual
1546 base, then BINFO has no primary base in this graph. Called from
1547 mark_primary_bases. DATA is the most derived type. */
1550 tree binfo;
1552 {
1557 {
1558 /* This morally virtual base has a primary base when it
1559 is a complete object. We need to locate the shared instance
1560 of this binfo in the type dominated by T. We duplicate the
1561 primary base information from there to here. */
1562 tree vbase;
1563 tree unshared_base;
1570 t));
1575 }
1578 /* The vtable fields will have been copied when duplicating the
1579 base binfos. That information is bogus, make sure we don't try
1580 and use it. */
1583 /* If this is a virtual primary base, make sure its offset matches
1584 that which it is primary for. */
1587 {
1592 }
1596 }
1598 /* Set BINFO_PRIMARY_BASE_OF for all binfos in the hierarchy
1599 dominated by TYPE that are primary bases. */
1601 static void
1603 tree type;
1604 {
1605 tree binfo;
1607 /* Walk the bases in inheritance graph order. */
1609 {
1610 tree base_binfo;
1613 /* Not a dynamic base. */
1625 }
1626 /* There could remain unshared morally virtual bases which were not
1627 visited in the inheritance graph walk. These bases will have lost
1628 their virtual primary base (should they have one). We must now
1629 find them. Also we must fix up the BINFO_OFFSETs of primary
1630 virtual bases. We could not do that as we went along, as they
1631 were originally copied from the bases we inherited from by
1632 unshare_base_binfos. That may have decided differently about
1633 where a virtual primary base went. */
1635 }
1637 /* Make the BINFO the primary base of T. */
1639 static void
1641 tree t;
1642 tree binfo;
1644 {
1645 tree basetype;
1654 }
1656 /* Determine the primary class for T. */
1658 static void
1660 tree t;
1662 {
1664 tree vbases;
1665 tree type_binfo;
1667 /* If there are no baseclasses, there is certainly no primary base. */
1674 {
1679 {
1680 /* Even a virtual baseclass can contain our RTTI
1681 information. But, we prefer a non-virtual polymorphic
1682 baseclass. */
1686 /* We prefer a non-virtual base, although a virtual one will
1687 do. */
1692 {
1695 }
1696 else
1697 {
1698 tree vfields;
1700 /* Only add unique vfields, and flatten them out as we go. */
1702 vfields;
1710 }
1711 }
1712 }
1717 /* Find the indirect primary bases - those virtual bases which are primary
1718 bases of something else in this hierarchy. */
1720 vbases;
1722 {
1725 /* See if this virtual base is an indirect primary base. To be so,
1726 it must be a primary base within the hierarchy of one of our
1727 direct bases. */
1729 {
1731 tree v;
1734 v;
1736 {
1742 {
1745 }
1746 }
1748 /* If we've discovered that this virtual base is an indirect
1749 primary base, then we can move on to the next virtual
1750 base. */
1753 }
1754 }
1756 /* A "nearly-empty" virtual base class can be the primary base
1757 class, if no non-virtual polymorphic base can be found. */
1759 {
1760 /* If not NULL, this is the best primary base candidate we have
1761 found so far. */
1763 tree base_binfo;
1765 /* Loop over the baseclasses. */
1767 base_binfo;
1769 {
1774 {
1775 /* If this is not an indirect primary base, then it's
1776 definitely our primary base. */
1778 {
1781 }
1783 /* If this is an indirect primary base, it still could be
1784 our primary base -- unless we later find there's another
1785 nearly-empty virtual base that isn't an indirect
1786 primary base. */
1789 }
1790 }
1792 /* If we've got a primary base, use it. */
1794 {
1798 }
1799 }
1801 /* Mark the primary base classes at this point. */
1803 }
1804 \f
1805 /* Set memoizing fields and bits of T (and its variants) for later
1806 use. */
1808 static void
1810 tree t;
1811 {
1814 /* Fix up variants (if any). */
1817 {
1818 /* These fields are in the _TYPE part of the node, not in
1819 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1830 /* Copy whatever these are holding today. */
1837 }
1840 /* For a class w/o baseclasses, `finish_struct' has set
1841 CLASS_TYPE_ABSTRACT_VIRTUALS correctly (by
1842 definition). Similarly for a class whose base classes do not
1843 have vtables. When neither of these is true, we might have
1844 removed abstract virtuals (by providing a definition), added
1845 some (by declaring new ones), or redeclared ones from a base
1846 class. We need to recalculate what's really an abstract virtual
1847 at this point (by looking in the vtables). */
1851 {
1852 /* Notice whether this class has type conversion functions defined. */
1855 tree basetype;
1858 {
1862 }
1863 }
1865 /* If this type has a copy constructor, force its mode to be BLKmode, and
1866 force its TREE_ADDRESSABLE bit to be nonzero. This will cause it to
1867 be passed by invisible reference and prevent it from being returned in
1868 a register.
1870 Also do this if the class has BLKmode but can still be returned in
1871 registers, since function_cannot_inline_p won't let us inline
1872 functions returning such a type. This affects the HP-PA. */
1876 {
1877 tree variants;
1880 {
1883 }
1884 }
1885 }
1887 /* Issue warnings about T having private constructors, but no friends,
1888 and so forth.
1890 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1891 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1892 non-private static member functions. */
1894 static void
1896 tree t;
1897 {
1900 tree fn;
1903 /* If the class has friends, those entities might create and
1904 access instances, so we should not warn. */
1907 /* We will have warned when the template was declared; there's
1908 no need to warn on every instantiation. */
1910 /* There's no reason to even consider warning about this
1911 class. */
1914 /* We only issue one warning, if more than one applies, because
1915 otherwise, on code like:
1917 class A {
1918 // Oops - forgot `public:'
1919 A();
1920 A(const A&);
1921 ~A();
1922 };
1924 we warn several times about essentially the same problem. */
1926 /* Check to see if all (non-constructor, non-destructor) member
1927 functions are private. (Since there are no friends or
1928 non-private statics, we can't ever call any of the private member
1929 functions.) */
1931 /* We're not interested in compiler-generated methods; they don't
1932 provide any way to call private members. */
1934 {
1936 {
1938 /* A non-private static member function is just like a
1939 friend; it can create and invoke private member
1940 functions, and be accessed without a class
1941 instance. */
1946 }
1949 }
1952 {
1953 /* There are no non-private methods, and there's at least one
1954 private member function that isn't a constructor or
1955 destructor. (If all the private members are
1956 constructors/destructors we want to use the code below that
1957 issues error messages specifically referring to
1958 constructors/destructors.) */
1964 {
1967 }
1969 {
1972 }
1973 }
1975 /* Even if some of the member functions are non-private, the class
1976 won't be useful for much if all the constructors or destructors
1977 are private: such an object can never be created or destroyed. */
1980 {
1982 t);
1984 }
1987 {
1990 /* If a non-template class does not define a copy
1991 constructor, one is defined for it, enabling it to avoid
1992 this warning. For a template class, this does not
1993 happen, and so we would normally get a warning on:
1995 template <class T> class C { private: C(); };
1997 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1998 complete non-template or fully instantiated classes have this
1999 flag set. */
2002 else
2004 fn;
2006 {
2008 /* Ideally, we wouldn't count copy constructors (or, in
2009 fact, any constructor that takes an argument of the
2010 class type as a parameter) because such things cannot
2011 be used to construct an instance of the class unless
2012 you already have one. But, for now at least, we're
2013 more generous. */
2015 {
2018 }
2019 }
2022 {
2024 t);
2026 }
2027 }
2028 }
2030 /* Function to help qsort sort FIELD_DECLs by name order. */
2032 static int
2035 {
2037 /* A nontype is "greater" than a type. */
2046 }
2048 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2050 static int
2053 {
2063 }
2065 /* Warn about duplicate methods in fn_fields. Also compact method
2066 lists so that lookup can be made faster.
2068 Data Structure: List of method lists. The outer list is a
2069 TREE_LIST, whose TREE_PURPOSE field is the field name and the
2070 TREE_VALUE is the DECL_CHAIN of the FUNCTION_DECLs. TREE_CHAIN
2071 links the entire list of methods for TYPE_METHODS. Friends are
2072 chained in the same way as member functions (? TREE_CHAIN or
2073 DECL_CHAIN), but they live in the TREE_TYPE field of the outer
2074 list. That allows them to be quickly deleted, and requires no
2075 extra storage.
2077 Sort methods that are not special (i.e., constructors, destructors,
2078 and type conversion operators) so that we can find them faster in
2079 search. */
2081 static void
2083 tree t;
2084 {
2085 tree fn_fields;
2086 tree method_vec;
2090 {
2091 /* Clear these for safety; perhaps some parsing error could set
2092 these incorrectly. */
2097 }
2103 /* First fill in entry 0 with the constructors, entry 1 with destructors,
2104 and the next few with type conversion operators (if any). */
2107 /* Clear out this flag. */
2111 /* We thought there was a destructor, but there wasn't. Some
2112 parse errors cause this anomalous situation. */
2115 /* Issue warnings about private constructors and such. If there are
2116 no methods, then some public defaults are generated. */
2119 /* Now sort the methods. */
2121 len--;
2124 /* The type conversion ops have to live at the front of the vec, so we
2125 can't sort them. */
2127 {
2132 }
2136 }
2138 /* Emit error when a duplicate definition of a type is seen. Patch up. */
2140 void
2142 tree t;
2143 {
2147 /* Pretend we haven't defined this type. */
2149 /* All of the component_decl's were TREE_CHAINed together in the parser.
2150 finish_struct_methods walks these chains and assembles all methods with
2151 the same base name into DECL_CHAINs. Now we don't need the parser chains
2152 anymore, so we unravel them. */
2154 /* This used to be in finish_struct, but it turns out that the
2155 TREE_CHAIN is used by dbxout_type_methods and perhaps some other
2156 things... */
2158 {
2162 {
2165 {
2168 }
2169 }
2170 }
2173 {
2189 }
2198 /* Clear TYPE_LANG_FLAGS -- those in TYPE_LANG_SPECIFIC are cleared above. */
2206 /* But not this one. */
2208 }
2210 /* Make BINFO's vtable have N entries, including RTTI entries,
2211 vbase and vcall offsets, etc. Set its type and call the backend
2212 to lay it out. */
2214 static void
2216 tree binfo;
2218 {
2219 tree atype;
2220 tree vtable;
2226 /* We may have to grow the vtable. */
2229 {
2234 /* At one time the vtable info was grabbed 2 words at a time. This
2235 fails on Sparc unless you have 8-byte alignment. */
2238 }
2239 }
2241 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2242 have the same signature. */
2244 int
2247 {
2248 /* One destructor overrides another if they are the same kind of
2249 destructor. */
2253 /* But a non-destructor never overrides a destructor, nor vice
2254 versa, nor do different kinds of destructors override
2255 one-another. For example, a complete object destructor does not
2256 override a deleting destructor. */
2261 {
2269 }
2271 }
2274 /* The function for which we are trying to find a final overrider. */
2275 tree fn;
2276 /* The base class in which the function was declared. */
2277 tree declaring_base;
2278 /* The most derived class in the hierarchy. */
2279 tree most_derived_type;
2280 /* The final overriding function. */
2281 tree overriding_fn;
2282 /* The functions that we thought might be final overriders, but
2283 aren't. */
2284 tree candidates;
2285 /* The BINFO for the class in which the final overriding function
2286 appears. */
2287 tree overriding_base;
2290 /* Called from find_final_overrider via dfs_walk. */
2292 static tree
2294 tree binfo;
2296 {
2303 {
2304 tree path;
2305 tree method;
2307 /* We haven't found an overrider yet. */
2309 /* We've found a path to the declaring base. Walk down the path
2310 looking for an overrider for FN. */
2312 path;
2314 {
2319 }
2321 /* If we found an overrider, record the overriding function, and
2322 the base from which it came. */
2324 {
2325 tree base;
2327 /* Assume the path is non-virtual. See if there are any
2328 virtual bases from (but not including) the overrider up
2329 to and including the base where the function is
2330 defined. */
2333 {
2336 }
2338 /* If we didn't already have an overrider, or any
2339 candidates, then this function is the best candidate so
2340 far. */
2342 {
2345 }
2347 {
2348 /* We had a best overrider; let's see how this compares. */
2351 && (tree_int_cst_equal
2354 /* We found the same overrider we already have, and in the
2357 /* The old function overrides this function; it's still the
2360 {
2361 /* The new function overrides the old; it's now the
2362 best. */
2365 }
2366 else
2367 {
2368 /* Ambiguous. */
2369 ffod->candidates
2373 ffod->candidates
2377 }
2378 }
2379 else
2380 {
2381 /* We had a list of ambiguous overrides; let's see how this
2382 new one compares. */
2384 tree candidates;
2387 /* If there were previous candidates, and this function
2388 overrides all of them, then it is the new best
2389 candidate. */
2391 candidates;
2393 {
2394 /* If the candidate overrides the METHOD, then we
2395 needn't worry about it any further. */
2397 method))
2398 {
2401 }
2403 /* If the METHOD doesn't override the candidate,
2404 then it is incomporable. */
2408 }
2410 /* If METHOD overrode all the candidates, then it is the
2411 new best candidate. */
2413 {
2417 }
2418 /* If METHOD didn't override all the candidates, then it
2419 is another candidate. */
2421 ffod->candidates
2423 }
2424 }
2425 }
2428 }
2430 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2431 FN and whose TREE_VALUE is the binfo for the base where the
2432 overriding occurs. BINFO (in the hierarchy dominated by T) is the
2433 base object in which FN is declared. */
2435 static tree
2437 tree t;
2438 tree binfo;
2439 tree fn;
2440 {
2441 find_final_overrider_data ffod;
2443 /* Getting this right is a little tricky. This is legal:
2445 struct S { virtual void f (); };
2446 struct T { virtual void f (); };
2447 struct U : public S, public T { };
2449 even though calling `f' in `U' is ambiguous. But,
2451 struct R { virtual void f(); };
2452 struct S : virtual public R { virtual void f (); };
2453 struct T : virtual public R { virtual void f (); };
2454 struct U : public S, public T { };
2456 is not -- there's no way to decide whether to put `S::f' or
2457 `T::f' in the vtable for `R'.
2459 The solution is to look at all paths to BINFO. If we find
2460 different overriders along any two, then there is a problem. */
2469 dfs_find_final_overrider,
2470 NULL,
2473 /* If there was no winner, issue an error message. */
2475 {
2478 }
2481 }
2483 /* Returns the function from the BINFO_VIRTUALS entry in T which matches
2484 the signature of FUNCTION_DECL FN, or NULL_TREE if none. In other words,
2485 the function that the slot in T's primary vtable points to. */
2488 static tree
2491 {
2492 tree f;
2498 }
2500 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2501 dominated by T. FN has been overriden in BINFO; VIRTUALS points to the
2502 corresponding position in the BINFO_VIRTUALS list. */
2504 static void
2506 tree t;
2507 tree binfo;
2508 tree fn;
2510 {
2511 tree b;
2512 tree overrider;
2513 tree delta;
2514 tree virtual_base;
2515 tree first_defn;
2517 /* Find the nearest primary base (possibly binfo itself) which defines
2518 this function; this is the class the caller will convert to when
2519 calling FN through BINFO. */
2521 {
2524 }
2527 /* Find the final overrider. */
2532 /* Assume that we will produce a thunk that convert all the way to
2533 the final overrider, and not to an intermediate virtual base. */
2536 /* We will convert to an intermediate virtual base first, and then
2537 use the vcall offset located there to finish the conversion. */
2539 {
2540 /* If we find the final overrider, then we can stop
2541 walking. */
2546 /* If we find a virtual base, and we haven't yet found the
2547 overrider, then there is a virtual base between the
2548 declaring base (first_defn) and the final overrider. */
2553 }
2555 /* Compute the constant adjustment to the `this' pointer. The
2556 `this' pointer, when this function is called, will point at BINFO
2557 (or one of its primary bases, which are at the same offset). */
2560 /* The `this' pointer needs to be adjusted from the declaration to
2561 the nearest virtual base. */
2564 else
2565 {
2566 /* The `this' pointer needs to be adjusted from pointing to
2567 BINFO to pointing at the base where the final overrider
2568 appears. */
2573 {
2574 /* We'll need a thunk. But if we have a (perhaps formerly)
2575 primary virtual base, we have a vcall slot for this function,
2576 so we can use it rather than create a non-virtual thunk. */
2580 {
2583 /* b doesn't have this function; no suitable vbase. */
2586 {
2587 /* Found one; we can treat ourselves as a virtual base. */
2591 }
2592 }
2593 }
2594 }
2597 binfo,
2599 delta,
2600 virtuals);
2604 }
2606 /* Called from modify_all_vtables via dfs_walk. */
2608 static tree
2610 tree binfo;
2612 {
2614 primary base; we're not going to use that vtable anyhow.
2615 We do still need to do this for virtual primary bases, as they
2616 could become non-primary in a construction vtable. */
2618 /* Similarly, a base without a vtable needs no modification. */
2620 {
2621 tree t;
2622 tree virtuals;
2623 tree old_virtuals;
2629 /* Now, go through each of the virtual functions in the virtual
2630 function table for BINFO. Find the final overrider, and
2631 update the BINFO_VIRTUALS list appropriately. */
2634 virtuals;
2638 binfo,
2641 }
2646 }
2648 /* Update all of the primary and secondary vtables for T. Create new
2649 vtables as required, and initialize their RTTI information. Each
2650 of the functions in OVERRIDDEN_VIRTUALS overrides a virtual
2651 function from a base class; find and modify the appropriate entries
2652 to point to the overriding functions. Returns a list, in
2653 declaration order, of the functions that are overridden in this
2654 class, but do not appear in the primary base class vtable, and
2655 which should therefore be appended to the end of the vtable for T. */
2657 static tree
2659 tree t;
2661 tree overridden_virtuals;
2662 {
2666 /* Update all of the vtables. */
2668 dfs_modify_vtables,
2669 dfs_unmarked_real_bases_queue_p,
2670 t);
2673 /* Include overriding functions for secondary vtables in our primary
2674 vtable. */
2676 {
2681 {
2682 /* Set the vtable index. */
2684 /* We don't need to convert to a base class when calling
2685 this function. */
2688 /* We don't need to adjust the `this' pointer when
2689 calling this function. */
2693 /* This is an overridden function not already in our
2694 vtable. Keep it. */
2696 }
2697 else
2698 /* We've already got an entry for this function. Skip it. */
2700 }
2703 }
2705 /* Here, we already know that they match in every respect.
2706 All we have to check is where they had their declarations. */
2708 static int
2711 {
2718 }
2720 /* Get the base virtual function declarations in T that are either
2721 overridden or hidden by FNDECL as a list. We set TREE_PURPOSE with
2722 the overrider/hider. */
2724 static tree
2727 {
2734 {
2741 }
2747 {
2752 base_fndecls);
2753 }
2756 }
2758 /* Mark the functions that have been hidden with their overriders.
2759 Since we start out with all functions already marked with a hider,
2760 no need to mark functions that are just hidden.
2762 Subroutine of warn_hidden. */
2764 static void
2767 {
2771 }
2773 /* If this declaration supersedes the declaration of
2774 a method declared virtual in the base class, then
2775 mark this field as being virtual as well. */
2777 static void
2780 {
2782 /* In [temp.mem] we have:
2784 A specialization of a member function template does not
2785 override a virtual function from a base class. */
2791 {
2792 /* Set DECL_VINDEX to a value that is neither an
2793 INTEGER_CST nor the error_mark_node so that
2794 add_virtual_function will realize this is an
2795 overriding function. */
2797 }
2799 {
2803 }
2804 }
2806 /* Warn about hidden virtual functions that are not overridden in t.
2807 We know that constructors and destructors don't apply. */
2809 void
2811 tree t;
2812 {
2817 /* We go through each separately named virtual function. */
2819 {
2827 /* First see if we have any virtual functions in this batch. */
2829 {
2833 }
2838 /* First we get a list of all possible functions that might be
2839 hidden from each base class. */
2841 {
2846 base_fndecls);
2847 }
2851 /* ...then mark up all the base functions with overriders, preferring
2852 overriders to hiders. */
2855 {
2859 }
2861 /* Now give a warning for all base functions without overriders,
2862 as they are hidden. */
2866 {
2867 /* Here we know it is a hider, and no overrider exists. */
2870 }
2871 }
2872 }
2874 /* Check for things that are invalid. There are probably plenty of other
2875 things we should check for also. */
2877 static void
2879 tree t;
2880 {
2881 tree field;
2884 {
2892 {
2895 {
2896 /* We're generally only interested in entities the user
2897 declared, but we also find nested classes by noticing
2898 the TYPE_DECL that we create implicitly. You're
2899 allowed to put one anonymous union inside another,
2900 though, so we explicitly tolerate that. */
2908 elt);
2911 {
2913 elt);
2915 }
2919 elt);
2922 elt);
2926 }
2927 }
2928 }
2929 }
2931 /* T is a class type that has an implicitly defined destructor. If it
2932 is trivial, set TYPE_HAS_NONTRIVIAL_DESTRUCTOR. */
2934 static void
2936 tree t;
2937 {
2939 tree f;
2941 /* [class.dtor]
2943 A destructor is trivial if it is an implicitly declared
2944 destructor and if:
2946 -- all of the direct base classes of its class have trivial
2947 destructors and
2949 -- for all of the non-static data members of its class that
2950 are of class type (or array thereof), each such class has a
2951 trivial destructor. */
2956 {
2959 }
2965 {
2968 }
2969 }
2971 /* Create default constructors, assignment operators, and so forth for
2972 the type indicated by T, if they are needed.
2973 CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2974 CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2975 class cannot have a default constructor, copy constructor taking a
2976 const reference argument, or an assignment operator taking a const
2977 reference, respectively. If a virtual destructor is created, its
2978 DECL is returned; otherwise the return value is NULL_TREE. */
2980 static tree
2982 cant_have_const_cctor,
2983 cant_have_const_assignment)
2984 tree t;
2988 {
2989 tree default_fn;
2994 /* If a destructor was explicitly declared, it is non-trivial. */
2997 /* Otherwise, declare one now. */
2998 else
2999 {
3000 /* Figure out whether the destructor will be trivial. */
3006 /* If we couldn't make it work, then pretend we didn't need it. */
3008 ;
3009 else
3010 {
3016 }
3017 }
3019 /* Default constructor. */
3021 {
3025 }
3027 /* Copy constructor. */
3029 {
3030 /* ARM 12.18: You get either X(X&) or X(const X&), but
3031 not both. --Chip */
3032 default_fn
3037 }
3039 /* Assignment operator. */
3041 {
3042 default_fn
3047 }
3049 /* Now, hook all of the new functions on to TYPE_METHODS,
3050 and add them to the CLASSTYPE_METHOD_VEC. */
3057 }
3059 /* Subroutine of finish_struct_1. Recursively count the number of fields
3060 in TYPE, including anonymous union members. */
3062 static int
3064 tree fields;
3065 {
3066 tree x;
3069 {
3072 else
3074 }
3076 }
3078 /* Subroutine of finish_struct_1. Recursively add all the fields in the
3079 TREE_LIST FIELDS to the TREE_VEC FIELD_VEC, starting at offset IDX. */
3081 static int
3085 {
3086 tree x;
3088 {
3091 else
3093 }
3095 }
3097 /* FIELD is a bit-field. We are finishing the processing for its
3098 enclosing type. Issue any appropriate messages and set appropriate
3099 flags. */
3101 static void
3103 tree field;
3104 {
3108 /* Detect invalid bit-field type. */
3111 {
3114 }
3116 /* Detect and ignore out of range field width. */
3118 {
3121 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3124 /* detect invalid field size. */
3127 else
3131 {
3133 field);
3135 }
3137 {
3140 }
3142 {
3145 }
3155 min_precision
3160 }
3162 /* Remove the bit-field width indicator so that the rest of the
3163 compiler does not treat that value as an initializer. */
3167 {
3172 {
3173 #ifdef EMPTY_FIELD_BOUNDARY
3175 EMPTY_FIELD_BOUNDARY);
3176 #endif
3177 #ifdef PCC_BITFIELD_TYPE_MATTERS
3179 {
3183 }
3184 #endif
3185 }
3186 }
3187 else
3188 {
3189 /* Non-bit-fields are aligned for their type. */
3194 }
3195 }
3197 /* FIELD is a non bit-field. We are finishing the processing for its
3198 enclosing type T. Issue any appropriate messages and set appropriate
3199 flags. */
3201 static void
3204 any_default_members)
3205 tree field;
3206 tree t;
3211 {
3214 /* An anonymous union cannot contain any fields which would change
3215 the settings of CANT_HAVE_CONST_CTOR and friends. */
3217 ;
3218 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
3219 structs. So, we recurse through their fields here. */
3221 {
3222 tree fields;
3228 any_default_members);
3229 }
3230 /* Check members with class type for constructors, destructors,
3231 etc. */
3233 {
3234 /* Never let anything with uninheritable virtuals
3235 make it through without complaint. */
3239 {
3242 field);
3245 field);
3248 field);
3249 }
3250 else
3251 {
3257 }
3268 }
3270 {
3271 /* `build_class_init_list' does not recognize
3272 non-FIELD_DECLs. */
3276 }
3278 /* Non-bit-fields are aligned for their type, except packed fields
3279 which require only BITS_PER_UNIT alignment. */
3282 ? BITS_PER_UNIT
3286 }
3288 /* Check the data members (both static and non-static), class-scoped
3289 typedefs, etc., appearing in the declaration of T. Issue
3290 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3291 declaration order) of access declarations; each TREE_VALUE in this
3292 list is a USING_DECL.
3294 In addition, set the following flags:
3296 EMPTY_P
3297 The class is empty, i.e., contains no non-static data members.
3299 CANT_HAVE_DEFAULT_CTOR_P
3300 This class cannot have an implicitly generated default
3301 constructor.
3303 CANT_HAVE_CONST_CTOR_P
3304 This class cannot have an implicitly generated copy constructor
3305 taking a const reference.
3307 CANT_HAVE_CONST_ASN_REF_P
3308 This class cannot have an implicitly generated assignment
3309 operator taking a const reference.
3311 All of these flags should be initialized before calling this
3312 function.
3314 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3315 fields can be added by adding to this chain. */
3317 static void
3319 cant_have_default_ctor_p,
3320 cant_have_const_ctor_p,
3321 cant_have_const_asn_ref_p)
3322 tree t;
3328 {
3334 /* First, delete any duplicate fields. */
3337 /* Assume there are no access declarations. */
3339 /* Assume this class has no pointer members. */
3341 /* Assume none of the members of this class have default
3342 initializations. */
3346 {
3355 {
3359 /* We don't treat zero-width bitfields as making a class
3360 non-empty. */
3361 ;
3362 else
3363 {
3364 /* The class is non-empty. */
3366 /* The class is not even nearly empty. */
3368 }
3369 }
3372 {
3373 /* Prune the access declaration from the list of fields. */
3376 /* Save the access declarations for our caller. */
3379 /* Since we've reset *FIELD there's no reason to skip to the
3380 next field. */
3383 }
3389 /* If we've gotten this far, it's a data member, possibly static,
3390 or an enumerator. */
3394 /* ``A local class cannot have static data members.'' ARM 9.4 */
3398 /* Perform error checking that did not get done in
3399 grokdeclarator. */
3401 {
3403 x);
3406 }
3408 {
3412 }
3414 {
3418 }
3423 /* When this goes into scope, it will be a non-local reference. */
3430 {
3432 /* Unions cannot have static members. */
3436 }
3438 /* Now it can only be a FIELD_DECL. */
3443 /* If this is of reference type, check if it needs an init.
3444 Also do a little ANSI jig if necessary. */
3446 {
3451 /* ARM $12.6.2: [A member initializer list] (or, for an
3452 aggregate, initialization by a brace-enclosed list) is the
3453 only way to initialize nonstatic const and reference
3454 members. */
3460 }
3471 /* DR 148 now allows pointers to members (which are POD themselves),
3472 to be allowed in POD structs. */
3475 /* If any field is const, the structure type is pseudo-const. */
3477 {
3482 /* ARM $12.6.2: [A member initializer list] (or, for an
3483 aggregate, initialization by a brace-enclosed list) is the
3484 only way to initialize nonstatic const and reference
3485 members. */
3491 }
3492 /* A field that is pseudo-const makes the structure likewise. */
3494 {
3498 }
3500 /* Core issue 80: A nonstatic data member is required to have a
3501 different name from the class iff the class has a
3502 user-defined constructor. */
3507 /* We set DECL_C_BIT_FIELD in grokbitfield.
3508 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3511 else
3513 cant_have_const_ctor_p,
3514 cant_have_default_ctor_p,
3515 cant_have_const_asn_ref_p,
3517 }
3519 /* Effective C++ rule 11. */
3522 {
3526 {
3530 }
3533 }
3536 /* Check anonymous struct/anonymous union fields. */
3539 /* We've built up the list of access declarations in reverse order.
3540 Fix that now. */
3542 }
3544 /* If TYPE is an empty class type, records its OFFSET in the table of
3545 OFFSETS. */
3547 static int
3549 tree type;
3550 tree offset;
3551 splay_tree offsets;
3552 {
3553 splay_tree_node n;
3558 /* Record the location of this empty object in OFFSETS. */
3566 type,
3570 }
3572 /* Returns non-zero if TYPE is an empty class type and there is
3573 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3575 static int
3577 tree type;
3578 tree offset;
3579 splay_tree offsets;
3580 {
3581 splay_tree_node n;
3582 tree t;
3587 /* Record the location of this empty object in OFFSETS. */
3597 }
3599 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3600 F for every subobject, passing it the type, offset, and table of
3601 OFFSETS. If VBASES_P is non-zero, then even virtual non-primary
3602 bases should be traversed; otherwise, they are ignored.
3604 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3605 than MAX_OFFSET will not be walked.
3607 If F returns a non-zero value, the traversal ceases, and that value
3608 is returned. Otherwise, returns zero. */
3610 static int
3612 tree type;
3613 subobject_offset_fn f;
3614 tree offset;
3615 splay_tree offsets;
3616 tree max_offset;
3618 {
3621 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3622 stop. */
3627 {
3628 tree field;
3631 /* Record the location of TYPE. */
3636 /* Iterate through the direct base classes of TYPE. */
3638 {
3647 f,
3649 offset,
3651 offsets,
3652 max_offset,
3653 vbases_p);
3656 }
3658 /* Iterate through the fields of TYPE. */
3661 {
3663 f,
3665 offset,
3667 offsets,
3668 max_offset,
3672 }
3673 }
3675 {
3677 tree index;
3679 /* Step through each of the elements in the array. */
3683 {
3685 f,
3686 offset,
3687 offsets,
3688 max_offset,
3694 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3695 there's no point in iterating through the remaining
3696 elements of the array. */
3699 }
3700 }
3703 }
3705 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3706 OFFSETS. If VBASES_P is non-zero, virtual bases of TYPE are
3707 examined. */
3709 static void
3711 tree type;
3712 tree offset;
3713 splay_tree offsets;
3715 {
3718 }
3720 /* Returns non-zero if any of the empty subobjects of TYPE (located at
3721 OFFSET) conflict with entries in OFFSETS. If VBASES_P is non-zero,
3722 virtual bases of TYPE are examined. */
3724 static int
3726 tree type;
3727 tree offset;
3728 splay_tree offsets;
3730 {
3731 splay_tree_node max_node;
3733 /* Get the node in OFFSETS that indicates the maximum offset where
3734 an empty subobject is located. */
3736 /* If there aren't any empty subobjects, then there's no point in
3737 performing this check. */
3743 vbases_p);
3744 }
3746 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3747 non-static data member of the type indicated by RLI. BINFO is the
3748 binfo corresponding to the base subobject, OFFSETS maps offsets to
3749 types already located at those offsets. T is the most derived
3750 type. This function determines the position of the DECL. */
3752 static void
3754 record_layout_info rli;
3755 tree decl;
3756 tree binfo;
3757 splay_tree offsets;
3758 tree t;
3759 {
3762 /* If we are laying out a base class, rather than a field, then
3763 DECL_ARTIFICIAL will be set on the FIELD_DECL. */
3766 /* Try to place the field. It may take more than one try if we have
3767 a hard time placing the field without putting two objects of the
3768 same type at the same address. */
3770 {
3773 /* Place this field. */
3777 /* We have to check to see whether or not there is already
3778 something of the same type at the offset we're about to use.
3779 For example:
3781 struct S {};
3782 struct T : public S { int i; };
3783 struct U : public S, public T {};
3785 Here, we put S at offset zero in U. Then, we can't put T at
3786 offset zero -- its S component would be at the same address
3787 as the S we already allocated. So, we have to skip ahead.
3788 Since all data members, including those whose type is an
3789 empty class, have non-zero size, any overlap can happen only
3790 with a direct or indirect base-class -- it can't happen with
3791 a data member. */
3793 offset,
3794 offsets,
3795 field_p))
3796 {
3797 /* Strip off the size allocated to this field. That puts us
3798 at the first place we could have put the field with
3799 proper alignment. */
3802 /* Bump up by the alignment required for the type. */
3803 rli->bitpos
3809 }
3810 else
3811 /* There was no conflict. We're done laying out this field. */
3813 }
3815 /* Now that we know where it will be placed, update its
3816 BINFO_OFFSET. */
3820 }
3822 /* Layout the empty base BINFO. EOC indicates the byte currently just
3823 past the end of the class, and should be correctly aligned for a
3824 class of the type indicated by BINFO; OFFSETS gives the offsets of
3825 the empty bases allocated so far. T is the most derived
3826 type. Return non-zero iff we added it at the end. */
3828 static bool
3830 tree binfo;
3831 tree eoc;
3832 splay_tree offsets;
3833 tree t;
3834 {
3835 tree alignment;
3839 /* This routine should only be used for empty classes. */
3843 /* This is an empty base class. We first try to put it at offset
3844 zero. */
3847 offsets,
3849 {
3850 /* That didn't work. Now, we move forward from the next
3851 available spot in the class. */
3855 {
3858 offsets,
3860 /* We finally found a spot where there's no overlap. */
3863 /* There's overlap here, too. Bump along to the next spot. */
3865 }
3866 }
3868 }
3870 /* Build a FIELD_DECL for the base given by BINFO in the class
3871 indicated by RLI. If the new object is non-empty, clear *EMPTY_P.
3872 *BASE_ALIGN is a running maximum of the alignments of any base
3873 class. OFFSETS gives the location of empty base subobjects. T is
3874 the most derived type. Return non-zero if the new object cannot be
3875 nearly-empty. */
3877 static bool
3879 record_layout_info rli;
3880 tree binfo;
3882 splay_tree offsets;
3883 tree t;
3884 {
3886 tree decl;
3890 /* This error is now reported in xref_tag, thus giving better
3891 location information. */
3903 {
3904 /* The containing class is non-empty because it has a non-empty
3905 base class. */
3908 /* Try to place the field. It may take more than one try if we
3909 have a hard time placing the field without putting two
3910 objects of the same type at the same address. */
3912 }
3913 else
3914 {
3917 /* On some platforms (ARM), even empty classes will not be
3918 byte-aligned. */
3922 }
3924 /* Record the offsets of BINFO and its base subobjects. */
3927 offsets,
3930 }
3932 /* Layout all of the non-virtual base classes. Record empty
3933 subobjects in OFFSETS. T is the most derived type. Return
3934 non-zero if the type cannot be nearly empty. */
3936 static bool
3938 record_layout_info rli;
3940 splay_tree offsets;
3941 tree t;
3942 {
3943 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3944 subobjects. */
3950 /* The primary base class is always allocated first. */
3955 /* Now allocate the rest of the bases. */
3957 {
3958 tree base_binfo;
3962 /* The primary base was already allocated above, so we don't
3963 need to allocate it again here. */
3967 /* A primary virtual base class is allocated just like any other
3968 base class, but a non-primary virtual base is allocated
3969 later, in layout_virtual_bases. */
3975 }
3977 }
3979 /* Go through the TYPE_METHODS of T issuing any appropriate
3980 diagnostics, figuring out which methods override which other
3981 methods, and so forth. */
3983 static void
3985 tree t;
3986 {
3987 tree x;
3990 {
3993 /* If this was an evil function, don't keep it in class. */
4002 /* The name of the field is the original field name
4003 Save this in auxiliary field for later overloading. */
4005 {
4010 }
4011 }
4012 }
4014 /* FN is a constructor or destructor. Clone the declaration to create
4015 a specialized in-charge or not-in-charge version, as indicated by
4016 NAME. */
4018 static tree
4020 tree fn;
4021 tree name;
4022 {
4023 tree parms;
4024 tree clone;
4026 /* Copy the function. */
4028 /* Remember where this function came from. */
4031 /* Reset the function name. */
4034 /* There's no pending inline data for this function. */
4037 /* And it hasn't yet been deferred. */
4040 /* The base-class destructor is not virtual. */
4042 {
4046 }
4048 /* If there was an in-charge parameter, drop it from the function
4049 type. */
4051 {
4052 tree basetype;
4053 tree parmtypes;
4054 tree exceptions;
4059 /* Skip the `this' parameter. */
4061 /* Skip the in-charge parameter. */
4063 /* And the VTT parm, in a complete [cd]tor. */
4067 /* If this is subobject constructor or destructor, add the vtt
4068 parameter. */
4072 parmtypes);
4075 exceptions);
4076 }
4078 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
4079 aren't function parameters; those are the template parameters. */
4081 {
4083 /* Remove the in-charge parameter. */
4085 {
4089 }
4090 /* And the VTT parm, in a complete [cd]tor. */
4092 {
4095 else
4096 {
4100 }
4101 }
4104 {
4107 }
4108 }
4110 /* Create the RTL for this function. */
4114 /* Make it easy to find the CLONE given the FN. */
4118 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
4120 {
4121 tree result;
4128 }
4133 }
4135 /* Produce declarations for all appropriate clones of FN. If
4136 UPDATE_METHOD_VEC_P is non-zero, the clones are added to the
4137 CLASTYPE_METHOD_VEC as well. */
4139 void
4141 tree fn;
4143 {
4144 tree clone;
4146 /* Avoid inappropriate cloning. */
4152 {
4153 /* For each constructor, we need two variants: an in-charge version
4154 and a not-in-charge version. */
4161 }
4162 else
4163 {
4166 /* For each destructor, we need three variants: an in-charge
4167 version, a not-in-charge version, and an in-charge deleting
4168 version. We clone the deleting version first because that
4169 means it will go second on the TYPE_METHODS list -- and that
4170 corresponds to the correct layout order in the virtual
4171 function table.
4173 For a non-virtual destructor, we do not build a deleting
4174 destructor. */
4176 {
4180 }
4187 }
4189 /* Note that this is an abstract function that is never emitted. */
4191 }
4193 /* DECL is an in charge constructor, which is being defined. This will
4194 have had an in class declaration, from whence clones were
4195 declared. An out-of-class definition can specify additional default
4196 arguments. As it is the clones that are involved in overload
4197 resolution, we must propagate the information from the DECL to its
4198 clones. */
4200 void
4202 tree decl;
4203 {
4204 tree clone;
4208 {
4215 /* Skip the 'this' parameter. */
4231 {
4236 {
4237 /* A default parameter has been added. Adjust the
4238 clone's parameters. */
4241 tree type;
4246 {
4249 clone_parms);
4251 }
4254 clone_parms);
4261 }
4262 }
4264 }
4265 }
4267 /* For each of the constructors and destructors in T, create an
4268 in-charge and not-in-charge variant. */
4270 static void
4272 tree t;
4273 {
4274 tree fns;
4276 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4277 out now. */
4284 }
4286 /* Remove all zero-width bit-fields from T. */
4288 static void
4290 tree t;
4291 {
4296 {
4301 else
4303 }
4304 }
4306 /* Returns TRUE iff we need a cookie when dynamically allocating an
4307 array whose elements have the indicated class TYPE. */
4309 static bool
4311 tree type;
4312 {
4313 tree fns;
4318 /* If there's a non-trivial destructor, we need a cookie. In order
4319 to iterate through the array calling the destructor for each
4320 element, we'll have to know how many elements there are. */
4324 /* If the usual deallocation function is a two-argument whose second
4325 argument is of type `size_t', then we have to pass the size of
4326 the array to the deallocation function, so we will need to store
4327 a cookie. */
4331 /* If there are no `operator []' members, or the lookup is
4332 ambiguous, then we don't need a cookie. */
4335 /* Loop through all of the functions. */
4337 {
4338 tree fn;
4339 tree second_parm;
4341 /* Select the current function. */
4343 /* See if this function is a one-argument delete function. If
4344 it is, then it will be the usual deallocation function. */
4348 /* Otherwise, if we have a two-argument function and the second
4349 argument is `size_t', it will be the usual deallocation
4350 function -- unless there is one-argument function, too. */
4354 }
4357 }
4359 /* Check the validity of the bases and members declared in T. Add any
4360 implicitly-generated functions (like copy-constructors and
4361 assignment operators). Compute various flag bits (like
4362 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4363 level: i.e., independently of the ABI in use. */
4365 static void
4367 tree t;
4369 {
4370 /* Nonzero if we are not allowed to generate a default constructor
4371 for this case. */
4373 /* Nonzero if the implicitly generated copy constructor should take
4374 a non-const reference argument. */
4376 /* Nonzero if the the implicitly generated assignment operator
4377 should take a non-const reference argument. */
4379 tree access_decls;
4381 /* By default, we use const reference arguments and generate default
4382 constructors. */
4387 /* Assume that the class is nearly empty; we'll clear this flag if
4388 it turns out not to be nearly empty. */
4391 /* Check all the base-classes. */
4395 /* Check all the data member declarations. */
4401 /* Check all the method declarations. */
4404 /* A nearly-empty class has to be vptr-containing; a nearly empty
4405 class contains just a vptr. */
4409 /* Do some bookkeeping that will guide the generation of implicitly
4410 declared member functions. */
4428 /* Synthesize any needed methods. Note that methods will be
4429 synthesized for anonymous unions but undone later by
4430 fixup_anonymous_aggr. */
4432 cant_have_const_ctor,
4433 no_const_asn_ref);
4435 /* Create the in-charge and not-in-charge variants of constructors
4436 and destructors. */
4439 /* Process the using-declarations. */
4443 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4446 /* Figure out whether or not we will need a cookie when dynamically
4447 allocating an array of this type. */
4450 }
4452 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4453 accordingly. If a new vfield was created (because T doesn't have a
4454 primary base class), then the newly created field is returned. It
4455 is not added to the TYPE_FIELDS list; it is the caller's
4456 responsibility to do that. */
4458 static tree
4461 tree t;
4466 {
4467 tree fn;
4469 /* Loop over the virtual functions, adding them to our various
4470 vtables. */
4476 /* If we couldn't find an appropriate base class, create a new field
4477 here. Even if there weren't any new virtual functions, we might need a
4478 new virtual function table if we're supposed to include vptrs in
4479 all classes that need them. */
4481 {
4482 /* We build this decl with vtbl_ptr_type_node, which is a
4483 `vtable_entry_type*'. It might seem more precise to use
4484 `vtable_entry_type (*)[N]' where N is the number of firtual
4485 functions. However, that would require the vtable pointer in
4486 base classes to have a different type than the vtable pointer
4487 in derived classes. We could make that happen, but that
4488 still wouldn't solve all the problems. In particular, the
4489 type-based alias analysis code would decide that assignments
4490 to the base class vtable pointer can't alias assignments to
4491 the derived class vtable pointer, since they have different
4492 types. Thus, in an derived class destructor, where the base
4493 class constructor was inlined, we could generate bad code for
4494 setting up the vtable pointer.
4496 Therefore, we use one type for all vtable pointers. We still
4497 use a type-correct type; it just doesn't indicate the array
4498 bounds. That's better than using `void*' or some such; it's
4499 cleaner, and it let's the alias analysis code know that these
4500 stores cannot alias stores to void*! */
4501 tree field;
4514 /* This class is non-empty. */
4518 /* If there were any baseclasses, they can't possibly be at
4519 offset zero any more, because that's where the vtable
4520 pointer is. So, converting to a base class is going to
4521 take work. */
4525 }
4528 }
4530 /* Fixup the inline function given by INFO now that the class is
4531 complete. */
4533 static void
4535 tree fn;
4536 {
4538 {
4541 {
4544 }
4545 }
4546 }
4548 /* Fixup the inline methods and friends in TYPE now that TYPE is
4549 complete. */
4551 static void
4553 tree type;
4554 {
4555 tree method;
4557 /* Do inline member functions. */
4559 method;
4563 /* Do friends. */
4565 method;
4569 }
4571 /* Add OFFSET to all base types of BINFO which is a base in the
4572 hierarchy dominated by T.
4574 OFFSET, which is a type offset, is number of bytes. */
4576 static void
4578 tree binfo;
4579 tree offset;
4580 tree t;
4581 {
4583 tree primary_binfo;
4585 /* Update BINFO's offset. */
4590 offset));
4592 /* Find the primary base class. */
4595 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4596 downwards. */
4598 {
4599 tree base_binfo;
4601 /* On the first time through the loop, do the primary base.
4602 Because the primary base need not be an immediate base, we
4603 must handle the primary base specially. */
4605 {
4610 }
4611 else
4612 {
4614 /* Don't do the primary base twice. */
4617 }
4619 /* Skip virtual bases that aren't our canonical primary base. */
4626 }
4627 }
4629 /* Called via dfs_walk from layout_virtual bases. */
4631 static tree
4633 tree binfo;
4635 {
4636 /* If this is a virtual base, make sure it has the same offset as
4637 the shared copy. If it's a primary base, then we know it's
4638 correct. */
4640 {
4642 tree vbase;
4643 tree offset;
4647 {
4650 }
4651 }
4654 }
4656 /* Set BINFO_OFFSET for all of the virtual bases for T. Update
4657 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4658 empty subobjects of T. */
4660 static void
4662 tree t;
4663 splay_tree offsets;
4664 {
4665 tree vbases;
4672 #ifdef STRUCTURE_SIZE_BOUNDARY
4673 /* Packed structures don't need to have minimum size. */
4676 #endif
4678 /* DSIZE is the size of the class without the virtual bases. */
4681 /* Make every class have alignment of at least one. */
4684 /* Go through the virtual bases, allocating space for each virtual
4685 base that is not already a primary base class. These are
4686 allocated in inheritance graph order. */
4688 vbases;
4690 {
4691 tree vbase;
4698 {
4699 /* This virtual base is not a primary base of any class in the
4700 hierarchy, so we have to add space for it. */
4701 tree basetype;
4709 /* Add padding so that we can put the virtual base class at an
4710 appropriately aligned offset. */
4713 /* We try to squish empty virtual bases in just like
4714 ordinary empty bases. */
4719 else
4720 {
4721 tree offset;
4728 /* And compute the offset of the virtual base. */
4730 /* Every virtual baseclass takes a least a UNIT, so that
4731 we can take it's address and get something different
4732 for each base. */
4735 }
4737 /* Keep track of the offsets assigned to this virtual base. */
4740 offsets,
4742 }
4743 }
4745 /* Now, go through the TYPE_BINFO hierarchy, setting the
4746 BINFO_OFFSETs correctly for all non-primary copies of the virtual
4747 bases and their direct and indirect bases. The ambiguity checks
4748 in get_base_distance depend on the BINFO_OFFSETs being set
4749 correctly. */
4752 /* If we had empty base classes that protruded beyond the end of the
4753 class, we didn't update DSIZE above; we were hoping to overlay
4754 multiple such bases at the same location. */
4759 /* Now, make sure that the total size of the type is a multiple of
4760 its alignment. */
4765 bitsize_unit_node));
4767 /* Check for ambiguous virtual bases. */
4770 vbases;
4772 {
4777 }
4778 }
4780 /* Returns the offset of the byte just past the end of the base class
4781 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4782 only non-virtual bases are included. */
4784 static unsigned HOST_WIDE_INT
4786 tree t;
4788 {
4793 {
4794 tree base_binfo;
4795 tree offset;
4796 tree size;
4807 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4808 allocate some space for it. It cannot have virtual bases,
4809 so TYPE_SIZE_UNIT is fine. */
4811 else
4815 size);
4819 }
4822 }
4824 /* Warn about direct bases of T that are inaccessible because they are
4825 ambiguous. For example:
4827 struct S {};
4828 struct T : public S {};
4829 struct U : public S, public T {};
4831 Here, `(S*) new U' is not allowed because there are two `S'
4832 subobjects of U. */
4834 static void
4836 tree t;
4837 {
4841 {
4847 }
4848 }
4850 /* Compare two INTEGER_CSTs K1 and K2. */
4852 static int
4854 splay_tree_key k1;
4855 splay_tree_key k2;
4856 {
4858 }
4860 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4861 BINFO_OFFSETs for all of the base-classes. Position the vtable
4862 pointer. */
4864 static void
4867 tree t;
4872 {
4873 tree non_static_data_members;
4874 tree field;
4875 tree vptr;
4876 record_layout_info rli;
4878 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4879 types that appear at that offset. */
4880 splay_tree empty_base_offsets;
4882 /* Keep track of the first non-static data member. */
4885 /* Start laying out the record. */
4888 /* If possible, we reuse the virtual function table pointer from one
4889 of our base classes. */
4892 /* Create a pointer to our virtual function table. */
4896 /* The vptr is always the first thing in the class. */
4898 {
4901 }
4903 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4909 /* CLASSTYPE_INLINE_FRIENDS is really TYPE_NONCOPIED_PARTS. Thus,
4910 we have to save this before we zap TYPE_NONCOPIED_PARTS. */
4913 /* Layout the non-static data members. */
4915 {
4916 tree type;
4917 tree padding;
4919 /* We still pass things that aren't non-static data members to
4920 the back-end, in case it wants to do something with them. */
4922 {
4925 }
4929 /* If this field is a bit-field whose width is greater than its
4930 type, then there are some special rules for allocating
4931 it. */
4934 {
4935 integer_type_kind itk;
4936 tree integer_type;
4938 /* We must allocate the bits as if suitably aligned for the
4939 longest integer type that fits in this many bits. type
4940 of the field. Then, we are supposed to use the left over
4941 bits as additional padding. */
4947 /* ITK now indicates a type that is too large for the
4948 field. We have to back up by one to find the largest
4949 type that fits. */
4956 }
4957 else
4963 /* If we needed additional padding after this field, add it
4964 now. */
4966 {
4967 tree padding_field;
4970 NULL_TREE,
4971 char_type_node);
4977 NULL_TREE,
4979 }
4980 }
4982 /* It might be the case that we grew the class to allocate a
4983 zero-sized base class. That won't be reflected in RLI, yet,
4984 because we are willing to overlay multiple bases at the same
4985 offset. However, now we need to make sure that RLI is big enough
4986 to reflect the entire class. */
4990 {
4993 }
4995 /* We make all structures have at least one element, so that they
4996 have non-zero size. The class may be empty even if it has
4997 basetypes. Therefore, we add the fake field after all the other
4998 fields; if there are already FIELD_DECLs on the list, their
4999 offsets will not be disturbed. */
5001 {
5002 tree padding;
5006 }
5008 /* Let the back-end lay out the type. Note that at this point we
5009 have only included non-virtual base-classes; we will lay out the
5010 virtual base classes later. So, the TYPE_SIZE/TYPE_ALIGN after
5011 this call are not necessarily correct; they are just the size and
5012 alignment when no virtual base clases are used. */
5015 /* Delete all zero-width bit-fields from the list of fields. Now
5016 that the type is laid out they are no longer important. */
5019 /* Remember the size and alignment of the class before adding
5020 the virtual bases. */
5022 {
5025 }
5026 else
5027 {
5030 }
5035 /* Set the TYPE_DECL for this type to contain the right
5036 value for DECL_OFFSET, so that we can use it as part
5037 of a COMPONENT_REF for multiple inheritance. */
5040 /* Now fix up any virtual base class types that we left lying
5041 around. We must get these done before we try to lay out the
5042 virtual function table. As a side-effect, this will remove the
5043 base subobject fields. */
5046 /* Warn about direct bases that can't be talked about due to
5047 ambiguity. */
5050 /* Clean up. */
5052 }
5054 /* Create a RECORD_TYPE or UNION_TYPE node for a C struct or union declaration
5055 (or C++ class declaration).
5057 For C++, we must handle the building of derived classes.
5058 Also, C++ allows static class members. The way that this is
5059 handled is to keep the field name where it is (as the DECL_NAME
5060 of the field), and place the overloaded decl in the bit position
5061 of the field. layout_record and layout_union will know about this.
5063 More C++ hair: inline functions have text in their
5064 DECL_PENDING_INLINE_INFO nodes which must somehow be parsed into
5065 meaningful tree structure. After the struct has been laid out, set
5066 things up so that this can happen.
5068 And still more: virtual functions. In the case of single inheritance,
5069 when a new virtual function is seen which redefines a virtual function
5070 from the base class, the new virtual function is placed into
5071 the virtual function table at exactly the same address that
5072 it had in the base class. When this is extended to multiple
5073 inheritance, the same thing happens, except that multiple virtual
5074 function tables must be maintained. The first virtual function
5075 table is treated in exactly the same way as in the case of single
5076 inheritance. Additional virtual function tables have different
5077 DELTAs, which tell how to adjust `this' to point to the right thing.
5079 ATTRIBUTES is the set of decl attributes to be applied, if any. */
5081 void
5083 tree t;
5084 {
5085 tree x;
5087 /* The NEW_VIRTUALS is a TREE_LIST. The TREE_VALUE of each node is
5088 a FUNCTION_DECL. Each of these functions is a virtual function
5089 declared in T that does not override any virtual function from a
5090 base class. */
5092 /* The OVERRIDDEN_VIRTUALS list is like the NEW_VIRTUALS list,
5093 except that each declaration here overrides the declaration from
5094 a base class. */
5097 tree vfield;
5101 {
5104 else
5108 }
5112 /* If this type was previously laid out as a forward reference,
5113 make sure we lay it out again. */
5120 /* Do end-of-class semantic processing: checking the validity of the
5121 bases and members and add implicitly generated methods. */
5124 /* Layout the class itself. */
5128 /* Make sure that we get our own copy of the vfield FIELD_DECL. */
5131 {
5137 /* The vtable better be at the start. */
5146 }
5147 else
5150 overridden_virtuals
5153 /* If we created a new vtbl pointer for this class, add it to the
5154 list. */
5159 /* If necessary, create the primary vtable for this class. */
5161 {
5163 /* We must enter these virtuals into the table. */
5167 /* Here we know enough to change the type of our virtual
5168 function table, but we will wait until later this function. */
5171 /* If this type has basetypes with constructors, then those
5172 constructors might clobber the virtual function table. But
5173 they don't if the derived class shares the exact vtable of the base
5174 class. */
5177 }
5178 /* If we didn't need a new vtable, see if we should copy one from
5179 the base. */
5181 {
5184 /* If this class uses a different vtable than its primary base
5185 then when we will need to initialize our vptr after the base
5186 class constructor runs. */
5189 }
5192 {
5201 /* Entries for virtual functions defined in the primary base are
5202 followed by entries for new functions unique to this class. */
5205 /* Finally, add entries for functions that override virtuals
5206 from non-primary bases. */
5209 }
5213 /* Complete the rtl for any static member objects of the type we're
5214 working on. */
5220 /* Done with FIELDS...now decide whether to sort these for
5221 faster lookups later.
5223 The C front-end only does this when n_fields > 15. We use
5224 a smaller number because most searches fail (succeeding
5225 ultimately as the search bores through the inheritance
5226 hierarchy), and we want this failure to occur quickly. */
5230 {
5238 }
5241 {
5245 {
5246 /* Mark the fact that constructor for T
5247 could affect anybody inheriting from T
5248 who wants to initialize vtables for VFIELDS's type. */
5252 }
5253 }
5255 /* Make the rtl for any new vtables we have created, and unmark
5256 the base types we marked. */
5259 /* Build the VTT for T. */
5275 /* Finish debugging output for this type. */
5277 }
5279 /* When T was built up, the member declarations were added in reverse
5280 order. Rearrange them to declaration order. */
5282 void
5284 tree t;
5285 {
5286 tree next;
5287 tree prev;
5288 tree x;
5290 /* The TYPE_FIELDS, TYPE_METHODS, and CLASSTYPE_TAGS are all in
5291 reverse order. Put them in declaration order now. */
5295 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5296 reverse order, so we can't just use nreverse. */
5301 {
5305 }
5307 {
5311 }
5312 }
5314 tree
5317 {
5321 /* Now that we've got all the field declarations, reverse everything
5322 as necessary. */
5327 /* Nadger the current location so that diagnostics point to the start of
5328 the struct, not the end. */
5333 {
5336 }
5337 else
5347 else
5351 {
5355 }
5358 }
5359 \f
5360 /* Return the dynamic type of INSTANCE, if known.
5361 Used to determine whether the virtual function table is needed
5362 or not.
5364 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5365 of our knowledge of its type. *NONNULL should be initialized
5366 before this function is called. */
5368 static tree
5370 tree instance;
5373 {
5375 {
5377 /* Check that we are not going through a cast of some sort. */
5381 /* fall through... */
5383 /* This is a call to a constructor, hence it's never zero. */
5385 {
5389 }
5393 /* This is a call to a constructor, hence it's never zero. */
5395 {
5399 }
5410 /* Propagate nonnull. */
5430 {
5434 }
5435 /* fall through... */
5439 {
5443 }
5445 {
5449 /* if we're in a ctor or dtor, we know our type. */
5453 {
5457 }
5458 }
5460 {
5461 /* Reference variables should be references to objects. */
5464 }
5469 }
5470 }
5472 /* Return non-zero if the dynamic type of INSTANCE is known, and equivalent
5473 to the static type. We also handle the case where INSTANCE is really
5474 a pointer. Return negative if this is a ctor/dtor. There the dynamic type
5475 is known, but this might not be the most derived base of the original object,
5476 and hence virtual bases may not be layed out according to this type.
5478 Used to determine whether the virtual function table is needed
5479 or not.
5481 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5482 of our knowledge of its type. *NONNULL should be initialized
5483 before this function is called. */
5485 int
5487 tree instance;
5489 {
5501 }
5503 \f
5504 void
5506 {
5509 current_class_stack
5527 }
5529 /* Set current scope to NAME. CODE tells us if this is a
5530 STRUCT, UNION, or ENUM environment.
5532 NAME may end up being NULL_TREE if this is an anonymous or
5533 late-bound struct (as in "struct { ... } foo;") */
5535 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE to
5536 appropriate values, found by looking up the type definition of
5537 NAME (as a CODE).
5539 If MODIFY is 1, we set IDENTIFIER_CLASS_VALUE's of names
5540 which can be seen locally to the class. They are shadowed by
5541 any subsequent local declaration (including parameter names).
5543 If MODIFY is 2, we set IDENTIFIER_CLASS_VALUE's of names
5544 which have static meaning (i.e., static members, static
5545 member functions, enum declarations, etc).
5547 If MODIFY is 3, we set IDENTIFIER_CLASS_VALUE of names
5548 which can be seen locally to the class (as in 1), but
5549 know that we are doing this for declaration purposes
5550 (i.e. friend foo::bar (int)).
5552 So that we may avoid calls to lookup_name, we cache the _TYPE
5553 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5555 For multiple inheritance, we perform a two-pass depth-first search
5556 of the type lattice. The first pass performs a pre-order search,
5557 marking types after the type has had its fields installed in
5558 the appropriate IDENTIFIER_CLASS_VALUE slot. The second pass merely
5559 unmarks the marked types. If a field or member function name
5560 appears in an ambiguous way, the IDENTIFIER_CLASS_VALUE of
5561 that name becomes `error_mark_node'. */
5563 void
5565 tree type;
5567 {
5570 /* Make sure there is enough room for the new entry on the stack. */
5572 {
5574 current_class_stack
5576 current_class_stack_size
5578 }
5580 /* Insert a new entry on the class stack. */
5585 current_class_depth++;
5587 /* Now set up the new type. */
5593 /* By default, things in classes are private, while things in
5594 structures or unions are public. */
5596 ? access_private_node
5603 {
5604 /* Forcibly remove any old class remnants. */
5606 }
5608 /* If we're about to enter a nested class, clear
5609 IDENTIFIER_CLASS_VALUE for the enclosing classes. */
5616 {
5619 else
5620 {
5621 tree item;
5623 /* We are re-entering the same class we just left, so we
5624 don't have to search the whole inheritance matrix to find
5625 all the decls to bind again. Instead, we install the
5626 cached class_shadowed list, and walk through it binding
5627 names and setting up IDENTIFIER_TYPE_VALUEs. */
5630 {
5637 }
5639 }
5642 }
5643 }
5645 /* When we exit a toplevel class scope, we save the
5646 IDENTIFIER_CLASS_VALUEs so that we can restore them quickly if we
5647 reenter the class. Here, we've entered some other class, so we
5648 must invalidate our cache. */
5650 void
5652 {
5653 tree t;
5655 /* The IDENTIFIER_CLASS_VALUEs are no longer valid. */
5661 }
5663 /* Get out of the current class scope. If we were in a class scope
5664 previously, that is the one popped to. */
5666 void
5668 {
5670 /* Since poplevel_class does the popping of class decls nowadays,
5671 this really only frees the obstack used for these decls. */
5674 current_class_depth--;
5680 }
5682 /* Returns 1 if current_class_type is either T or a nested type of T.
5683 We start looking from 1 because entry 0 is from global scope, and has
5684 no type. */
5686 int
5688 tree t;
5689 {
5697 }
5699 /* If either current_class_type or one of its enclosing classes are derived
5700 from T, return the appropriate type. Used to determine how we found
5701 something via unqualified lookup. */
5703 tree
5705 tree t;
5706 {
5717 }
5719 /* When entering a class scope, all enclosing class scopes' names with
5720 static meaning (static variables, static functions, types and enumerators)
5721 have to be visible. This recursive function calls pushclass for all
5722 enclosing class contexts until global or a local scope is reached.
5723 TYPE is the enclosed class and MODIFY is equivalent with the pushclass
5724 formal of the same name. */
5726 void
5728 tree type;
5730 {
5731 tree context;
5733 /* FIXME: This check should go in push_scope, analagous to the
5734 handling of pop_scope vs. pop_nested_class. */
5743 }
5745 /* Undoes a push_nested_class call. */
5747 void
5749 {
5750 tree context;
5757 }
5759 /* Returns the number of extern "LANG" blocks we are nested within. */
5761 int
5763 {
5765 }
5767 /* Set global variables CURRENT_LANG_NAME to appropriate value
5768 so that behavior of name-mangling machinery is correct. */
5770 void
5772 tree name;
5773 {
5777 {
5779 }
5781 {
5783 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5784 (See record_builtin_java_type in decl.c.) However, that causes
5785 incorrect debug entries if these types are actually used.
5786 So we re-enable debug output after extern "Java". */
5795 }
5797 {
5799 }
5800 else
5802 }
5804 /* Get out of the current language scope. */
5806 void
5808 {
5811 }
5812 \f
5813 /* Type instantiation routines. */
5815 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5816 matches the TARGET_TYPE. If there is no satisfactory match, return
5817 error_mark_node, and issue an error message if COMPLAIN is
5818 non-zero. Permit pointers to member function if PTRMEM is non-zero.
5819 If TEMPLATE_ONLY, the name of the overloaded function
5820 was a template-id, and EXPLICIT_TARGS are the explicitly provided
5821 template arguments. */
5823 static tree
5825 overload,
5826 complain,
5827 ptrmem,
5828 template_only,
5829 explicit_targs)
5830 tree target_type;
5831 tree overload;
5835 tree explicit_targs;
5836 {
5837 /* Here's what the standard says:
5839 [over.over]
5841 If the name is a function template, template argument deduction
5842 is done, and if the argument deduction succeeds, the deduced
5843 arguments are used to generate a single template function, which
5844 is added to the set of overloaded functions considered.
5846 Non-member functions and static member functions match targets of
5847 type "pointer-to-function" or "reference-to-function." Nonstatic
5848 member functions match targets of type "pointer-to-member
5849 function;" the function type of the pointer to member is used to
5850 select the member function from the set of overloaded member
5851 functions. If a nonstatic member function is selected, the
5852 reference to the overloaded function name is required to have the
5853 form of a pointer to member as described in 5.3.1.
5855 If more than one function is selected, any template functions in
5856 the set are eliminated if the set also contains a non-template
5857 function, and any given template function is eliminated if the
5858 set contains a second template function that is more specialized
5859 than the first according to the partial ordering rules 14.5.5.2.
5860 After such eliminations, if any, there shall remain exactly one
5861 selected function. */
5865 /* We store the matches in a TREE_LIST rooted here. The functions
5866 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5867 interoperability with most_specialized_instantiation. */
5869 tree fn;
5871 /* By the time we get here, we should be seeing only real
5872 pointer-to-member types, not the internal POINTER_TYPE to
5873 METHOD_TYPE representation. */
5881 /* Check that the TARGET_TYPE is reasonable. */
5885 /* This is OK, too. */
5888 {
5889 /* This is OK, too. This comes from a conversion to reference
5890 type. */
5893 }
5894 else
5895 {
5901 }
5903 /* If we can find a non-template function that matches, we can just
5904 use it. There's no point in generating template instantiations
5905 if we're just going to throw them out anyhow. But, of course, we
5906 can only do this when we don't *need* a template function. */
5908 {
5909 tree fns;
5912 {
5914 tree fntype;
5917 /* We're not looking for templates just yet. */
5922 /* We're looking for a non-static member, and this isn't
5923 one, or vice versa. */
5926 /* See if there's a match. */
5935 }
5936 }
5938 /* Now, if we've already got a match (or matches), there's no need
5939 to proceed to the template functions. But, if we don't have a
5940 match we need to look at them, too. */
5942 {
5943 tree target_fn_type;
5944 tree target_arg_types;
5945 tree target_ret_type;
5946 tree fns;
5949 target_fn_type
5951 else
5956 /* Never do unification on the 'this' parameter. */
5961 {
5963 tree instantiation;
5964 tree instantiation_type;
5965 tree targs;
5968 /* We're only looking for templates. */
5973 /* We're not looking for a non-static member, and this is
5974 one, or vice versa. */
5977 /* Try to do argument deduction. */
5982 /* Argument deduction failed. */
5985 /* Instantiate the template. */
5988 /* Instantiation failed. */
5991 /* See if there's a match. */
5994 instantiation_type =
6000 }
6002 /* Now, remove all but the most specialized of the matches. */
6004 {
6009 }
6010 }
6012 /* Now we should have exactly one function in MATCHES. */
6014 {
6015 /* There were *no* matches. */
6017 {
6020 target_type);
6022 /* print_candidates expects a chain with the functions in
6023 TREE_VALUE slots, so we cons one up here (we're losing anyway,
6024 so why be clever?). */
6027 matches);
6030 }
6032 }
6034 {
6035 /* There were too many matches. */
6038 {
6039 tree match;
6043 target_type);
6045 /* Since print_candidates expects the functions in the
6046 TREE_VALUE slot, we flip them here. */
6051 }
6054 }
6056 /* Good, exactly one match. Now, convert it to the correct type. */
6061 {
6069 {
6072 }
6073 }
6080 else
6081 {
6082 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
6083 will mark the function as addressed, but here we must do it
6084 explicitly. */
6088 }
6089 }
6091 /* This function will instantiate the type of the expression given in
6092 RHS to match the type of LHSTYPE. If errors exist, then return
6093 error_mark_node. FLAGS is a bit mask. If ITF_COMPLAIN is set, then
6094 we complain on errors. If we are not complaining, never modify rhs,
6095 as overload resolution wants to try many possible instantiations, in
6096 the hope that at least one will work.
6098 For non-recursive calls, LHSTYPE should be a function, pointer to
6099 function, or a pointer to member function. */
6101 tree
6105 {
6114 {
6118 }
6121 {
6128 }
6130 /* We don't overwrite rhs if it is an overloaded function.
6131 Copying it would destroy the tree link. */
6135 /* This should really only be used when attempting to distinguish
6136 what sort of a pointer to function we have. For now, any
6137 arithmetic operation which is not supported on pointers
6138 is rejected as an error. */
6141 {
6152 {
6153 tree new_rhs;
6163 }
6180 /* This can happen if we are forming a pointer-to-member for a
6181 member template. */
6184 /* Fall through. */
6187 {
6194 return
6196 fns,
6197 complain,
6198 allow_ptrmem,
6200 args);
6201 }
6204 return
6206 rhs,
6207 complain,
6208 allow_ptrmem,
6216 /* This is too hard for now. */
6290 {
6294 }
6317 {
6322 }
6333 }
6334 }
6335 \f
6336 /* Return the name of the virtual function pointer field
6337 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6338 this may have to look back through base types to find the
6339 ultimate field name. (For single inheritance, these could
6340 all be the same name. Who knows for multiple inheritance). */
6342 static tree
6344 tree type;
6345 {
6359 }
6361 void
6363 {
6364 #ifdef GATHER_STATISTICS
6370 {
6375 }
6376 #endif
6377 }
6379 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6380 according to [class]:
6382 The class-name is also inserted into the scope of the class
6383 itself. For purposes of access checking, the inserted class name
6384 is treated as if it were a public member name. */
6386 void
6388 {
6391 tree saved_cas;
6404 }
6406 /* Returns 1 if TYPE contains only padding bytes. */
6408 int
6410 tree type;
6411 {
6419 }
6421 /* Find the enclosing class of the given NODE. NODE can be a *_DECL or
6422 a *_TYPE node. NODE can also be a local class. */
6424 tree
6426 tree type;
6427 {
6431 {
6433 {
6446 }
6447 }
6449 }
6451 /* Return 1 if TYPE or one of its enclosing classes is derived from BASE. */
6453 int
6456 {
6458 {
6463 }
6465 }
6467 /* Note that NAME was looked up while the current class was being
6468 defined and that the result of that lookup was DECL. */
6470 void
6472 tree name;
6473 tree decl;
6474 {
6475 splay_tree names_used;
6477 /* If we're not defining a class, there's nothing to do. */
6481 /* If there's already a binding for this NAME, then we don't have
6482 anything to worry about. */
6494 }
6496 /* Note that NAME was declared (as DECL) in the current class. Check
6497 to see that the declaration is legal. */
6499 void
6501 tree name;
6502 tree decl;
6503 {
6504 splay_tree names_used;
6505 splay_tree_node n;
6507 /* Look to see if we ever used this name. */
6508 names_used
6515 {
6516 /* [basic.scope.class]
6518 A name N used in a class S shall refer to the same declaration
6519 in its context and when re-evaluated in the completed scope of
6520 S. */
6525 }
6526 }
6528 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6529 Secondary vtables are merged with primary vtables; this function
6530 will return the VAR_DECL for the primary vtable. */
6532 tree
6534 tree binfo;
6535 {
6536 tree decl;
6540 {
6544 }
6548 }
6550 /* Called from get_primary_binfo via dfs_walk. DATA is a TREE_LIST
6551 who's TREE_PURPOSE is the TYPE of the required primary base and
6552 who's TREE_VALUE is a list of candidate binfos that we fill in. */
6554 static tree
6556 tree binfo;
6558 {
6564 /* This is the right type of binfo, but it might be an unshared
6565 instance, and the shared instance is later in the dfs walk. We
6566 must keep looking. */
6570 }
6572 /* Returns the unshared binfo for the primary base of BINFO. Note
6573 that in a complex hierarchy the resulting BINFO may not actually
6574 *be* primary. In particular if the resulting BINFO is a virtual
6575 base, and it occurs elsewhere in the hierarchy, then this
6576 occurrence may not actually be a primary base in the complete
6577 object. Check BINFO_PRIMARY_P to be sure. */
6579 tree
6581 tree binfo;
6582 {
6583 tree primary_base;
6585 tree virtuals;
6591 /* A non-virtual primary base is always a direct base, and easy to
6592 find. */
6594 {
6597 /* Scan the direct basetypes until we find a base with the same
6598 type as the primary base. */
6600 {
6606 }
6608 /* We should always find the primary base. */
6610 }
6612 /* For a primary virtual base, we have to scan the entire hierarchy
6613 rooted at BINFO; the virtual base could be an indirect virtual
6614 base. There could be more than one instance of the primary base
6615 in the hierarchy, and if one is the canonical binfo we want that
6616 one. If it exists, it should be the first one we find, but as a
6617 consistency check we find them all and make sure. */
6622 /* We must have found at least one instance. */
6626 {
6627 /* We found more than one instance of the base. We must make
6628 sure that, if one is the canonical one, it is the first one
6629 we found. As the chain is in reverse dfs order, that means
6630 the last on the list. */
6631 tree complete_binfo;
6632 tree canonical;
6642 {
6646 {
6647 /* This is the unshared instance. Make sure it was the
6648 first one found. */
6651 }
6652 }
6653 }
6654 else
6657 }
6659 /* If INDENTED_P is zero, indent to INDENT. Return non-zero. */
6661 static int
6666 {
6670 }
6672 /* Dump the offsets of all the bases rooted at BINFO (in the hierarchy
6673 dominated by T) to stderr. INDENT should be zero when called from
6674 the top level; it is incremented recursively. */
6676 static void
6680 tree t;
6681 tree binfo;
6683 {
6698 {
6704 else
6706 }
6711 {
6715 TFF_PLAIN_IDENTIFIER),
6717 }
6719 {
6722 }
6727 {
6731 {
6735 TFF_PLAIN_IDENTIFIER));
6736 }
6738 {
6742 TFF_PLAIN_IDENTIFIER));
6743 }
6745 {
6749 TFF_PLAIN_IDENTIFIER));
6750 }
6752 {
6756 TFF_PLAIN_IDENTIFIER));
6757 }
6761 }
6768 }
6770 /* Dump the BINFO hierarchy for T. */
6772 static void
6774 tree t;
6775 {
6789 }
6791 static void
6794 tree decl;
6795 {
6796 tree inits;
6798 HOST_WIDE_INT elt;
6806 TFF_PLAIN_IDENTIFIER));
6813 }
6815 static void
6817 tree t;
6818 tree binfo;
6819 tree vtable;
6820 {
6828 {
6835 {
6839 }
6843 }
6846 }
6848 static void
6850 tree t;
6851 tree vtt;
6852 {
6860 {
6865 }
6868 }
6870 /* Virtual function table initialization. */
6872 /* Create all the necessary vtables for T and its base classes. */
6874 static void
6876 tree t;
6877 {
6878 tree list;
6879 tree vbase;
6881 /* We lay out the primary and secondary vtables in one contiguous
6882 vtable. The primary vtable is first, followed by the non-virtual
6883 secondary vtables in inheritance graph order. */
6888 /* Then come the virtual bases, also in inheritance graph order. */
6890 {
6891 tree real_base;
6896 /* Although we walk in inheritance order, that might not get the
6897 canonical base. */
6902 }
6906 }
6908 /* Initialize the vtable for BINFO with the INITS. */
6910 static void
6912 tree binfo;
6913 tree inits;
6914 {
6915 tree decl;
6921 }
6923 /* Initialize DECL (a declaration for a namespace-scope array) with
6924 the INITS. */
6926 static void
6928 tree decl;
6929 tree inits;
6930 {
6931 tree context;
6938 }
6940 /* Build the VTT (virtual table table) for T.
6941 A class requires a VTT if it has virtual bases.
6943 This holds
6944 1 - primary virtual pointer for complete object T
6945 2 - secondary VTTs for each direct non-virtual base of T which requires a
6946 VTT
6947 3 - secondary virtual pointers for each direct or indirect base of T which
6948 has virtual bases or is reachable via a virtual path from T.
6949 4 - secondary VTTs for each direct or indirect virtual base of T.
6951 Secondary VTTs look like complete object VTTs without part 4. */
6953 static void
6955 tree t;
6956 {
6957 tree inits;
6958 tree type;
6959 tree vtt;
6960 tree index;
6962 /* Build up the initializers for the VTT. */
6967 /* If we didn't need a VTT, we're done. */
6971 /* Figure out the type of the VTT. */
6975 /* Now, build the VTT object itself. */
6981 }
6983 /* The type corresponding to BASE_BINFO is a base of the type of BINFO, but
6984 from within some heirarchy which is inherited from the type of BINFO.
6985 Return BASE_BINFO's equivalent binfo from the hierarchy dominated by
6986 BINFO. */
6988 static tree
6990 tree base_binfo;
6991 tree binfo;
6992 {
6993 tree derived;
7008 }
7010 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7011 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7012 and CHAIN the vtable pointer for this binfo after construction is
7013 complete. VALUE can also be another BINFO, in which case we recurse. */
7015 static tree
7017 tree binfo;
7018 {
7019 tree vt;
7022 {
7028 else
7030 }
7033 }
7035 /* Recursively build the VTT-initializer for BINFO (which is in the
7036 hierarchy dominated by T). INITS points to the end of the initializer
7037 list to date. INDEX is the VTT index where the next element will be
7038 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7039 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7040 for virtual bases of T. When it is not so, we build the constructor
7041 vtables for the BINFO-in-T variant. */
7045 tree binfo;
7046 tree t;
7049 {
7051 tree b;
7052 tree init;
7053 tree secondary_vptrs;
7056 /* We only need VTTs for subobjects with virtual bases. */
7060 /* We need to use a construction vtable if this is not the primary
7061 VTT. */
7063 {
7066 /* Record the offset in the VTT where this sub-VTT can be found. */
7068 }
7070 /* Add the address of the primary vtable for the complete object. */
7075 {
7078 }
7081 /* Recursively add the secondary VTTs for non-virtual bases. */
7083 {
7088 }
7090 /* Add secondary virtual pointers for all subobjects of BINFO with
7091 either virtual bases or reachable along a virtual path, except
7092 subobjects that are non-virtual primary bases. */
7099 dfs_build_secondary_vptr_vtt_inits,
7100 NULL,
7101 dfs_ctor_vtable_bases_queue_p,
7102 secondary_vptrs);
7105 secondary_vptrs);
7109 /* The secondary vptrs come back in reverse order. After we reverse
7110 them, and add the INITS, the last init will be the first element
7111 of the chain. */
7114 {
7118 }
7120 /* Add the secondary VTTs for virtual bases. */
7123 {
7124 tree vbase;
7131 }
7134 {
7140 dfs_ctor_vtable_bases_queue_p,
7141 data);
7142 }
7145 }
7147 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo
7148 for the base in most derived. DATA is a TREE_LIST who's
7149 TREE_CHAIN is the type of the base being
7150 constructed whilst this secondary vptr is live. The TREE_UNSIGNED
7151 flag of DATA indicates that this is a constructor vtable. The
7152 TREE_TOP_LEVEL flag indicates that this is the primary VTT. */
7154 static tree
7156 tree binfo;
7158 {
7159 tree l;
7160 tree t;
7161 tree init;
7162 tree index;
7171 /* We don't care about bases that don't have vtables. */
7175 /* We're only interested in proper subobjects of T. */
7179 /* We're not interested in non-virtual primary bases. */
7183 /* If BINFO has virtual bases or is reachable via a virtual path
7184 from T, it'll have a secondary vptr. */
7189 /* Record the index where this secondary vptr can be found. */
7192 {
7195 }
7199 /* Add the initializer for the secondary vptr itself. */
7201 {
7202 /* It's a primary virtual base, and this is not the construction
7203 vtable. Find the base this is primary of in the inheritance graph,
7204 and use that base's vtable now. */
7207 }
7212 }
7214 /* dfs_walk_real predicate for building vtables. DATA is a TREE_LIST,
7215 VTT_MARKED_BINFO_P indicates whether marked or unmarked bases
7216 should be walked. TREE_PURPOSE is the TREE_TYPE that dominates the
7217 hierarchy. */
7219 static tree
7221 tree binfo;
7223 {
7225 /* Get the shared version. */
7231 }
7233 /* Called from build_vtt_inits via dfs_walk. After building constructor
7234 vtables and generating the sub-vtt from them, we need to restore the
7235 BINFO_VTABLES that were scribbled on. DATA is a TREE_LIST whose
7236 TREE_VALUE is the TREE_TYPE of the base whose sub vtt was generated. */
7238 static tree
7240 tree binfo;
7242 {
7245 /* We don't care about bases that don't have vtables. */
7249 /* If we scribbled the construction vtable vptr into BINFO, clear it
7250 out now. */
7258 }
7260 /* Build the construction vtable group for BINFO which is in the
7261 hierarchy dominated by T. */
7263 static void
7265 tree binfo;
7266 tree t;
7267 {
7268 tree list;
7269 tree type;
7270 tree vtbl;
7271 tree inits;
7272 tree id;
7273 tree vbase;
7275 /* See if we've already created this construction vtable group. */
7281 /* Build a version of VTBL (with the wrong type) for use in
7282 constructing the addresses of secondary vtables in the
7283 construction vtable group. */
7289 /* Add the vtables for each of our virtual bases using the vbase in T
7290 binfo. */
7292 vbase;
7294 {
7295 tree b;
7296 tree orig_base;
7304 }
7307 /* Figure out the type of the construction vtable. */
7312 /* Initialize the construction vtable. */
7316 }
7318 /* Add the vtbl initializers for BINFO (and its bases other than
7319 non-virtual primaries) to the list of INITS. BINFO is in the
7320 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7321 the constructor the vtbl inits should be accumulated for. (If this
7322 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7323 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7324 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7325 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7326 but are not necessarily the same in terms of layout. */
7328 static void
7330 tree binfo;
7331 tree orig_binfo;
7332 tree rtti_binfo;
7333 tree t;
7334 tree inits;
7335 {
7343 /* If it doesn't have a vptr, we don't do anything. */
7347 /* If we're building a construction vtable, we're not interested in
7348 subobjects that don't require construction vtables. */
7354 /* Build the initializers for the BINFO-in-T vtable. */
7360 /* Walk the BINFO and its bases. We walk in preorder so that as we
7361 initialize each vtable we can figure out at what offset the
7362 secondary vtable lies from the primary vtable. We can't use
7363 dfs_walk here because we need to iterate through bases of BINFO
7364 and RTTI_BINFO simultaneously. */
7366 {
7369 /* Skip virtual bases. */
7375 inits);
7376 }
7377 }
7379 /* Called from accumulate_vtbl_inits. Returns the initializers for
7380 the BINFO vtable. */
7382 static tree
7384 tree binfo;
7385 tree orig_binfo;
7386 tree rtti_binfo;
7387 tree t;
7388 tree l;
7389 {
7396 {
7397 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7398 primary virtual base. If it is not the same primary in
7399 the hierarchy of T, we'll need to generate a ctor vtable
7400 for it, to place at its location in T. If it is the same
7401 primary, we still need a VTT entry for the vtable, but it
7402 should point to the ctor vtable for the base it is a
7403 primary for within the sub-hierarchy of RTTI_BINFO.
7405 There are three possible cases:
7407 1) We are in the same place.
7408 2) We are a primary base within a lost primary virtual base of
7409 RTTI_BINFO.
7410 3) We are primary to something not a base of RTTI_BINFO. */
7415 /* First, look through the bases we are primary to for RTTI_BINFO
7416 or a virtual base. */
7418 {
7422 }
7423 /* If we run out of primary links, keep looking down our
7424 inheritance chain; we might be an indirect primary. */
7430 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7431 base B and it is a base of RTTI_BINFO, this is case 2. In
7432 either case, we share our vtable with LAST, i.e. the
7433 derived-most base within B of which we are a primary. */
7437 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7438 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7439 binfo_ctor_vtable after everything's been set up. */
7442 /* Otherwise, this is case 3 and we get our own. */
7443 }
7448 {
7449 tree index;
7452 /* Compute the initializer for this vtable. */
7456 /* Figure out the position to which the VPTR should point. */
7459 vtbl_ptr_type_node,
7460 vtbl);
7467 index);
7470 }
7473 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7474 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7475 straighten this out. */
7479 else
7480 /* For an ordinary vtable, set BINFO_VTABLE. */
7484 }
7486 /* Construct the initializer for BINFO's virtual function table. BINFO
7487 is part of the hierarchy dominated by T. If we're building a
7488 construction vtable, the ORIG_BINFO is the binfo we should use to
7489 find the actual function pointers to put in the vtable - but they
7490 can be overridden on the path to most-derived in the graph that
7491 ORIG_BINFO belongs. Otherwise,
7492 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7493 BINFO that should be indicated by the RTTI information in the
7494 vtable; it will be a base class of T, rather than T itself, if we
7495 are building a construction vtable.
7497 The value returned is a TREE_LIST suitable for wrapping in a
7498 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7499 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7500 number of non-function entries in the vtable.
7502 It might seem that this function should never be called with a
7503 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7504 base is always subsumed by a derived class vtable. However, when
7505 we are building construction vtables, we do build vtables for
7506 primary bases; we need these while the primary base is being
7507 constructed. */
7509 static tree
7511 tree binfo;
7512 tree orig_binfo;
7513 tree t;
7514 tree rtti_binfo;
7516 {
7518 tree vfun_inits;
7519 tree vbase;
7520 vtbl_init_data vid;
7522 /* Initialize VID. */
7530 /* The first vbase or vcall offset is at index -3 in the vtable. */
7533 /* Add entries to the vtable for RTTI. */
7536 /* Create an array for keeping track of the functions we've
7537 processed. When we see multiple functions with the same
7538 signature, we share the vcall offsets. */
7540 /* Add the vcall and vbase offset entries. */
7542 /* Clean up. */
7544 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7545 build_vbase_offset_vtbl_entries. */
7547 vbase;
7554 /* Go through all the ordinary virtual functions, building up
7555 initializers. */
7558 {
7559 tree delta;
7560 tree vcall_index;
7561 tree fn;
7562 tree pfn;
7563 tree init;
7565 /* Pull the offset for `this', and the function to call, out of
7566 the list. */
7570 {
7573 }
7574 else
7581 /* You can't call an abstract virtual function; it's abstract.
7582 So, we replace these functions with __pure_virtual. */
7586 /* Take the address of the function, considering it to be of an
7587 appropriate generic type. */
7589 /* The address of a function can't change. */
7592 /* Enter it in the vtable. */
7595 /* If the only definition of this function signature along our
7596 primary base chain is from a lost primary, this vtable slot will
7597 never be used, so just zero it out. This is important to avoid
7598 requiring extra thunks which cannot be generated with the function.
7600 We could also handle this in update_vtable_entry_for_fn; doing it
7601 here means we zero out unused slots in ctor vtables as well,
7602 rather than filling them with erroneous values (though harmless,
7603 apart from relocation costs). */
7606 {
7607 /* We found a defn before a lost primary; go ahead as normal. */
7611 /* The nearest definition is from a lost primary; clear the
7612 slot. */
7614 {
7617 }
7618 }
7620 /* And add it to the chain of initializers. */
7622 }
7624 /* The initializers for virtual functions were built up in reverse
7625 order; straighten them out now. */
7628 /* The negative offset initializers are also in reverse order. */
7631 /* Chain the two together. */
7633 }
7635 /* Adds to vid->inits the initializers for the vbase and vcall
7636 offsets in BINFO, which is in the hierarchy dominated by T. */
7638 static void
7640 tree binfo;
7642 {
7643 tree b;
7645 /* If this is a derived class, we must first create entries
7646 corresponding to the primary base class. */
7651 /* Add the vbase entries for this base. */
7653 /* Add the vcall entries for this base. */
7655 }
7657 /* Returns the initializers for the vbase offset entries in the vtable
7658 for BINFO (which is part of the class hierarchy dominated by T), in
7659 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7660 where the next vbase offset will go. */
7662 static void
7664 tree binfo;
7666 {
7667 tree vbase;
7668 tree t;
7669 tree non_primary_binfo;
7671 /* If there are no virtual baseclasses, then there is nothing to
7672 do. */
7678 /* We might be a primary base class. Go up the inheritance hierarchy
7679 until we find the most derived class of which we are a primary base:
7680 it is the offset of that which we need to use. */
7683 {
7684 tree b;
7686 /* If we have reached a virtual base, then it must be a primary
7687 base (possibly multi-level) of vid->binfo, or we wouldn't
7688 have called build_vcall_and_vbase_vtbl_entries for it. But it
7689 might be a lost primary, so just skip down to vid->binfo. */
7691 {
7694 }
7700 }
7702 /* Go through the virtual bases, adding the offsets. */
7704 vbase;
7706 {
7707 tree b;
7708 tree delta;
7713 /* Find the instance of this virtual base in the complete
7714 object. */
7717 /* If we've already got an offset for this virtual base, we
7718 don't need another one. */
7723 /* Figure out where we can find this vbase offset. */
7732 {
7733 tree orig_vbase;
7735 /* Find the instance of this virtual base in the type of BINFO. */
7739 /* The vbase offset had better be the same. */
7743 }
7745 /* The next vbase will come at a more negative offset. */
7748 /* The initializer is the delta from BINFO to this virtual base.
7749 The vbase offsets go in reverse inheritance-graph order, and
7750 we are walking in inheritance graph order so these end up in
7751 the right order. */
7757 vtable_entry_type,
7758 delta)));
7760 }
7761 }
7763 /* Adds the initializers for the vcall offset entries in the vtable
7764 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7765 to VID->INITS. */
7767 static void
7769 tree binfo;
7771 {
7772 /* We only need these entries if this base is a virtual base. */
7776 /* We need a vcall offset for each of the virtual functions in this
7777 vtable. For example:
7779 class A { virtual void f (); };
7780 class B1 : virtual public A { virtual void f (); };
7781 class B2 : virtual public A { virtual void f (); };
7782 class C: public B1, public B2 { virtual void f (); };
7784 A C object has a primary base of B1, which has a primary base of A. A
7785 C also has a secondary base of B2, which no longer has a primary base
7786 of A. So the B2-in-C construction vtable needs a secondary vtable for
7787 A, which will adjust the A* to a B2* to call f. We have no way of
7788 knowing what (or even whether) this offset will be when we define B2,
7789 so we store this "vcall offset" in the A sub-vtable and look it up in
7790 a "virtual thunk" for B2::f.
7792 The location of `A' is not at a fixed offset relative to `B'; the
7793 offset depends on the complete object derived from `B'. So,
7794 `B' vtable contains an entry for `f' that indicates by what
7795 amount the `this' pointer for `B' needs to be adjusted to arrive
7796 at `A'.
7798 We need entries for all the functions in our primary vtable and
7799 in our non-virtual bases' secondary vtables. */
7801 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7803 }
7805 /* Build vcall offsets, starting with those for BINFO. */
7807 static void
7809 tree binfo;
7811 {
7813 tree primary_binfo;
7815 /* Don't walk into virtual bases -- except, of course, for the
7816 virtual base for which we are building vcall offsets. Any
7817 primary virtual base will have already had its offsets generated
7818 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7822 /* If BINFO has a primary base, process it first. */
7827 /* Add BINFO itself to the list. */
7830 /* Scan the non-primary bases of BINFO. */
7832 {
7833 tree base_binfo;
7838 }
7839 }
7841 /* Called from build_vcall_offset_vtbl_entries_r. */
7843 static void
7845 tree binfo;
7847 {
7848 tree derived_virtuals;
7849 tree base_virtuals;
7850 tree orig_virtuals;
7851 tree binfo_inits;
7852 /* If BINFO is a primary base, the most derived class which has BINFO as
7853 a primary base; otherwise, just BINFO. */
7854 tree non_primary_binfo;
7858 /* We might be a primary base class. Go up the inheritance hierarchy
7859 until we find the most derived class of which we are a primary base:
7860 it is the BINFO_VIRTUALS there that we need to consider. */
7863 {
7864 tree b;
7866 /* If we have reached a virtual base, then it must be vid->vbase,
7867 because we ignore other virtual bases in
7868 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7869 base (possibly multi-level) of vid->binfo, or we wouldn't
7870 have called build_vcall_and_vbase_vtbl_entries for it. But it
7871 might be a lost primary, so just skip down to vid->binfo. */
7873 {
7878 }
7884 }
7887 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7888 where rtti_binfo is the most derived type. */
7889 non_primary_binfo = get_original_base
7892 /* Make entries for the rest of the virtuals. */
7896 base_virtuals;
7900 {
7901 tree orig_fn;
7902 tree fn;
7903 tree base;
7904 tree base_binfo;
7906 tree vcall_offset;
7908 /* Find the declaration that originally caused this function to
7909 be present in BINFO_TYPE (binfo). */
7912 /* When processing BINFO, we only want to generate vcall slots for
7913 function slots introduced in BINFO. So don't try to generate
7914 one if the function isn't even defined in BINFO. */
7918 /* Find the overriding function. */
7921 /* If there is already an entry for a function with the same
7922 signature as FN, then we do not need a second vcall offset.
7923 Check the list of functions already present in the derived
7924 class vtable. */
7926 {
7927 tree derived_entry;
7931 /* We only use one vcall offset for virtual destructors,
7932 even though there are two virtual table entries. */
7935 {
7940 }
7941 }
7945 /* The FN comes from BASE. So, we must calculate the adjustment from
7946 vid->vbase to BASE. We can just look for BASE in the complete
7947 object because we are converting from a virtual base, so if there
7948 were multiple copies, there would not be a unique final overrider
7949 and vid->derived would be ill-formed. */
7953 /* Compute the vcall offset. */
7954 /* As mentioned above, the vbase we're working on is a primary base of
7955 vid->binfo. But it might be a lost primary, so its BINFO_OFFSET
7956 might be wrong, so we just use the BINFO_OFFSET from vid->binfo. */
7959 vcall_offset);
7961 vcall_offset));
7966 /* Keep track of the vtable index where this vcall offset can be
7967 found. For a construction vtable, we already made this
7968 annotation when we built the original vtable. */
7972 /* The next vcall offset will be found at a more negative
7973 offset. */
7976 /* Keep track of this function. */
7978 }
7979 }
7981 /* Return vtbl initializers for the RTTI entries coresponding to the
7982 BINFO's vtable. The RTTI entries should indicate the object given
7983 by VID->rtti_binfo. */
7985 static void
7987 tree binfo;
7989 {
7990 tree b;
7991 tree t;
7992 tree basetype;
7993 tree offset;
7994 tree decl;
7995 tree init;
8000 /* To find the complete object, we will first convert to our most
8001 primary base, and then add the offset in the vtbl to that value. */
8005 {
8006 tree primary_base;
8011 }
8014 /* The second entry is the address of the typeinfo object. */
8017 else
8020 /* Convert the declaration to a type that can be stored in the
8021 vtable. */
8027 /* Add the offset-to-top entry. It comes earlier in the vtable that
8028 the the typeinfo entry. Convert the offset to look like a
8029 function pointer, so that we can put it in the vtable. */
8034 }
8036 /* Build an entry in the virtual function table. DELTA is the offset
8037 for the `this' pointer. VCALL_INDEX is the vtable index containing
8038 the vcall offset; NULL_TREE if none. ENTRY is the virtual function
8039 table entry itself. It's TREE_TYPE must be VFUNC_PTR_TYPE_NODE,
8040 but it may not actually be a virtual function table pointer. (For
8041 example, it might be the address of the RTTI object, under the new
8042 ABI.) */
8044 static tree
8046 tree delta;
8047 tree vcall_index;
8048 tree entry;
8049 {
8054 {
8059 }
8060 #ifdef GATHER_STATISTICS
8062 #endif
8064 }