| blob | 0dffc62ea695443f51d574cb29c01a67f74780cf |
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, 2002 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 /* The number of nested classes being processed. If we are not in the
39 scope of any class, this is zero. */
43 /* In order to deal with nested classes, we keep a stack of classes.
44 The topmost entry is the innermost class, and is the entry at index
45 CURRENT_CLASS_DEPTH */
48 /* The name of the class. */
49 tree name;
51 /* The _TYPE node for the class. */
52 tree type;
54 /* The access specifier pending for new declarations in the scope of
55 this class. */
56 tree access;
58 /* If were defining TYPE, the names used in this class. */
59 splay_tree names_used;
63 {
64 /* The base for which we're building initializers. */
65 tree binfo;
66 /* The type of the most-derived type. */
67 tree derived;
68 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
69 unless ctor_vtbl_p is true. */
70 tree rtti_binfo;
71 /* The negative-index vtable initializers built up so far. These
72 are in order from least negative index to most negative index. */
73 tree inits;
74 /* The last (i.e., most negative) entry in INITS. */
76 /* The binfo for the virtual base for which we're building
77 vcall offset initializers. */
78 tree vbase;
79 /* The functions in vbase for which we have already provided vcall
80 offsets. */
81 varray_type fns;
82 /* The vtable index of the next vcall or vbase offset. */
83 tree index;
84 /* Nonzero if we are building the initializer for the primary
85 vtable. */
87 /* Nonzero if we are building the initializer for a construction
88 vtable. */
90 /* True when adding vcall offset entries to the vtable. False when
91 merely computing the indices. */
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;
178 tree));
181 vtbl_init_data *));
207 splay_tree_key k2));
217 /* Macros for dfs walking during vtt construction. See
218 dfs_ctor_vtable_bases_queue_p, dfs_build_secondary_vptr_vtt_inits
219 and dfs_fixup_binfo_vtbls. */
220 #define VTT_TOP_LEVEL_P(NODE) TREE_UNSIGNED (NODE)
221 #define VTT_MARKED_BINFO_P(NODE) TREE_USED (NODE)
223 /* Variables shared between class.c and call.c. */
225 #ifdef GATHER_STATISTICS
234 #endif
236 /* Convert to or from a base subobject. EXPR is an expression of type
237 `A' or `A*', an expression of type `B' or `B*' is returned. To
238 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
239 the B base instance within A. To convert base A to derived B, CODE
240 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
241 In this latter case, A must not be a morally virtual base of B.
242 NONNULL is true if EXPR is known to be non-NULL (this is only
243 needed when EXPR is of pointer type). CV qualifiers are preserved
244 from EXPR. */
246 tree
249 tree expr;
250 tree binfo;
252 {
255 tree probe;
256 tree offset;
257 tree target_type;
259 tree ptr_target_type;
267 {
271 }
284 {
288 }
302 {
303 /* Going via virtual base V_BINFO. We need the static offset
304 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
305 V_BINFO. That offset is an entry in D_BINFO's vtable. */
315 v_offset);
326 /* Negative fixed_type_p means this is a constructor or destructor;
327 virtual base layout is fixed in in-charge [cd]tors, but not in
328 base [cd]tors. */
332 v_offset,
334 else
336 }
340 target_type = cp_build_qualified_type
350 else
359 expr);
362 }
364 /* Convert OBJECT to the base TYPE. If CHECK_ACCESS is true, an error
365 message is emitted if TYPE is inaccessible. OBJECT is assumed to
366 be non-NULL. */
368 tree
370 {
371 tree binfo;
375 NULL);
380 }
382 \f
383 /* Virtual function things. */
385 static tree
388 {
410 }
412 /* Given an object INSTANCE, return an expression which yields the
413 vtable element corresponding to INDEX. There are many special
414 cases for INSTANCE which we take care of here, mainly to avoid
415 creating extra tree nodes when we don't have to. */
417 static tree
420 {
421 tree aref;
424 /* Try to figure out what a reference refers to, and
425 access its virtual function table directly. */
435 {
440 }
443 {
445 }
453 }
455 tree
458 {
465 }
467 /* Given an object INSTANCE, return an expression which yields a
468 function pointer corresponding to vtable element INDEX. */
470 tree
473 {
476 /* When using function descriptors, the address of the
477 vtable entry is treated as a function pointer. */
486 }
488 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
489 for the given TYPE. */
491 static tree
493 tree type;
494 {
496 }
498 /* Return an IDENTIFIER_NODE for the name of the virtual table table
499 for TYPE. */
501 tree
503 tree type;
504 {
506 }
508 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
509 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
510 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
512 static tree
514 tree class_type;
515 tree name;
516 tree vtable_type;
517 {
518 tree decl;
521 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
522 now to avoid confusion in mangle_decl. */
534 }
536 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
537 or even complete. If this does not exist, create it. If COMPLETE is
538 nonzero, then complete the definition of it -- that will render it
539 impossible to actually build the vtable, but is useful to get at those
540 which are known to exist in the runtime. */
542 tree
544 tree type;
546 {
547 tree decl;
555 /* At one time the vtable info was grabbed 2 words at a time. This
556 fails on sparc unless you have 8-byte alignment. (tiemann) */
561 {
564 }
567 }
569 /* Returns a copy of the BINFO_VIRTUALS list in BINFO. The
570 BV_VCALL_INDEX for each entry is cleared. */
572 static tree
574 tree binfo;
575 {
576 tree copies;
577 tree t;
584 }
586 /* Build the primary virtual function table for TYPE. If BINFO is
587 non-NULL, build the vtable starting with the initial approximation
588 that it is the same as the one which is the head of the association
589 list. Returns a nonzero value if a new vtable is actually
590 created. */
592 static int
595 {
596 tree decl;
597 tree virtuals;
602 {
604 /* We have already created a vtable for this base, so there's
605 no need to do it again. */
612 }
613 else
614 {
618 }
620 #ifdef GATHER_STATISTICS
623 #endif
625 /* Initialize the association list for this type, based
626 on our first approximation. */
631 }
633 /* Give BINFO a new virtual function table which is initialized
634 with a skeleton-copy of its original initialization. The only
635 entry that changes is the `delta' entry, so we can really
636 share a lot of structure.
638 FOR_TYPE is the most derived type which caused this table to
639 be needed.
641 Returns nonzero if we haven't met BINFO before.
643 The order in which vtables are built (by calling this function) for
644 an object must remain the same, otherwise a binary incompatibility
645 can result. */
647 static int
650 {
654 /* We already created a vtable for this base. There's no need to
655 do it again. */
658 /* Remember that we've created a vtable for this BINFO, so that we
659 don't try to do so again. */
662 /* Make fresh virtual list, so we can smash it later. */
665 /* Secondary vtables are laid out as part of the same structure as
666 the primary vtable. */
669 }
671 /* Create a new vtable for BINFO which is the hierarchy dominated by
672 T. Return nonzero if we actually created a new vtable. */
674 static int
676 tree t;
677 tree binfo;
678 {
680 /* In this case, it is *type*'s vtable we are modifying. We start
681 with the approximation that its vtable is that of the
682 immediate base class. */
683 /* ??? This actually passes TYPE_BINFO (t), not the primary base binfo,
684 since we've updated DECL_CONTEXT (TYPE_VFIELD (t)) by now. */
686 t);
687 else
688 /* This is our very own copy of `basetype' to play with. Later,
689 we will fill in all the virtual functions that override the
690 virtual functions in these base classes which are not defined
691 by the current type. */
693 }
695 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
696 (which is in the hierarchy dominated by T) list FNDECL as its
697 BV_FN. DELTA is the required constant adjustment from the `this'
698 pointer where the vtable entry appears to the `this' required when
699 the function is actually called. */
701 static void
703 tree t;
704 tree binfo;
705 tree fndecl;
706 tree delta;
708 {
709 tree v;
715 {
716 tree base_fndecl;
718 /* We need a new vtable for BINFO. */
720 {
721 /* If we really did make a new vtable, we also made a copy
722 of the BINFO_VIRTUALS list. Now, we have to find the
723 corresponding entry in that list. */
728 }
734 }
735 }
737 \f
738 /* Add method METHOD to class TYPE. If ERROR_P is true, we are adding
739 the method after the class has already been defined because a
740 declaration for it was seen. (Even though that is erroneous, we
741 add the method for improved error recovery.) */
743 void
745 tree type;
746 tree method;
748 {
752 tree method_vec;
757 /* Make a new method vector. We start with 8 entries. We must
758 allocate at least two (for constructors and destructors), and
759 we're going to end up with an assignment operator at some point
760 as well.
762 We could use a TREE_LIST for now, and convert it to a TREE_VEC
763 in finish_struct, but we would probably waste more memory
764 making the links in the list than we would by over-allocating
765 the size of the vector here. Furthermore, we would complicate
766 all the code that expects this to be a vector. */
772 /* Constructors and destructors go in special slots. */
777 else
778 {
781 /* See if we already have an entry with this name. */
783 {
791 {
795 /* If we need to move things up, see if there's
796 space. */
798 {
801 slot++;
802 }
804 }
807 }
810 {
811 /* We need a bigger method vector. */
813 tree new_vec;
815 /* In the non-error case, we are processing a class
816 definition. Double the size of the vector to give room
817 for new methods. */
820 /* In the error case, the vector is already complete. We
821 don't expect many errors, and the rest of the front-end
822 will get confused if there are empty slots in the vector. */
823 else
831 }
834 {
835 /* Type conversion operators have to come before ordinary
836 methods; add_conversions depends on this to speed up
837 looking for conversion operators. So, if necessary, we
838 slide some of the vector elements up. In theory, this
839 makes this algorithm O(N^2) but we don't expect many
840 conversion operators. */
843 else
845 {
849 /* There are no more entries in the vector, so we
850 can insert the new conversion operator here. */
854 /* We can insert the new function right at the
855 SLOTth position. */
857 }
862 /* There is nothing in the Ith slot, so we can avoid
863 moving anything. */
864 ;
865 else
866 {
867 /* We know the last slot in the vector is empty
868 because we know that at this point there's room
869 for a new function. */
874 }
875 }
876 }
879 /* TYPE is a template class. Don't issue any errors now; wait
880 until instantiation time to complain. */
881 ;
882 else
883 {
884 tree fns;
886 /* Check to see if we've already got this method. */
888 fns;
890 {
892 tree parms1;
893 tree parms2;
899 /* [over.load] Member function declarations with the
900 same name and the same parameter types cannot be
901 overloaded if any of them is a static member
902 function declaration.
904 [namespace.udecl] When a using-declaration brings names
905 from a base class into a derived class scope, member
906 functions in the derived class override and/or hide member
907 functions with the same name and parameter types in a base
908 class (rather than conflicting). */
912 /* Compare the quals on the 'this' parm. Don't compare
913 the whole types, as used functions are treated as
914 coming from the using class in overload resolution. */
921 /* For templates, the template parms must be identical. */
936 {
938 /* Defer to the local function. */
940 else
941 {
945 /* We don't call duplicate_decls here to merge
946 the declarations because that will confuse
947 things if the methods have inline
948 definitions. In particular, we will crash
949 while processing the definitions. */
951 }
952 }
953 }
954 }
956 /* Actually insert the new method. */
960 /* Add the new binding. */
965 }
967 /* Subroutines of finish_struct. */
969 /* Look through the list of fields for this struct, deleting
970 duplicates as we go. This must be recursive to handle
971 anonymous unions.
973 FIELD is the field which may not appear anywhere in FIELDS.
974 FIELD_PTR, if non-null, is the starting point at which
975 chained deletions may take place.
976 The value returned is the first acceptable entry found
977 in FIELDS.
979 Note that anonymous fields which are not of UNION_TYPE are
980 not duplicates, they are just anonymous fields. This happens
981 when we have unnamed bitfields, for example. */
983 static tree
986 {
987 tree x;
990 {
997 }
998 else
999 {
1001 {
1003 {
1009 {
1012 else
1014 }
1015 }
1017 /* A using declaration is allowed to appear more than
1018 once. We'll prune these from the field list later, and
1019 handle_using_decl will complain about invalid multiple
1020 uses. */
1021 ;
1023 {
1030 x);
1033 {
1037 }
1040 {
1041 /* Hide tag decls. */
1048 x);
1049 }
1050 else
1054 else
1056 }
1057 }
1058 }
1060 }
1062 static void
1064 tree fields;
1065 {
1066 tree x;
1069 }
1071 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1072 legit, otherwise return 0. */
1074 static int
1076 tree t;
1077 tree fdecl;
1078 tree access;
1079 {
1080 tree elem;
1090 {
1092 {
1095 else
1098 }
1099 else
1100 {
1101 /* They're changing the access to the same thing they changed
1102 it to before. That's OK. */
1103 ;
1104 }
1105 }
1106 else
1107 {
1111 }
1113 }
1115 /* Process the USING_DECL, which is a member of T. */
1117 static void
1119 tree using_decl;
1120 tree t;
1121 {
1124 tree access
1130 tree old_value;
1134 {
1137 }
1140 {
1143 }
1145 {
1148 }
1153 {
1156 }
1159 /* Ignore base type this came from. */
1164 {
1170 else
1172 }
1178 ;
1180 {
1182 /* It's OK to use functions from a base when there are functions with
1184 else
1185 {
1190 }
1191 }
1193 {
1197 }
1199 /* Make type T see field decl FDECL with access ACCESS.*/
1202 {
1205 }
1206 else
1208 }
1209 \f
1210 /* Run through the base clases of T, updating
1211 CANT_HAVE_DEFAULT_CTOR_P, CANT_HAVE_CONST_CTOR_P, and
1212 NO_CONST_ASN_REF_P. Also set flag bits in T based on properties of
1213 the bases. */
1215 static void
1217 no_const_asn_ref_p)
1218 tree t;
1222 {
1226 tree binfos;
1232 /* An aggregate cannot have baseclasses. */
1236 {
1237 tree base_binfo;
1238 tree basetype;
1240 /* Figure out what base we're looking at. */
1244 /* If the type of basetype is incomplete, then we already
1245 complained about that fact (and we should have fixed it up as
1246 well). */
1248 {
1250 /* The base type is of incomplete type. It is
1251 probably best to pretend that it does not
1252 exist. */
1260 }
1262 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1263 here because the case of virtual functions but non-virtual
1264 dtor is handled in finish_struct_1. */
1268 basetype);
1270 /* If the base class doesn't have copy constructors or
1271 assignment operators that take const references, then the
1272 derived class cannot have such a member automatically
1273 generated. */
1279 /* Similarly, if the base class doesn't have a default
1280 constructor, then the derived class won't have an
1281 automatically generated default constructor. */
1284 {
1288 basetype);
1289 }
1292 /* A virtual base does not effect nearly emptiness. */
1293 ;
1295 {
1297 /* And if there is more than one nearly empty base, then the
1298 derived class is not nearly empty either. */
1300 else
1301 /* Remember we've seen one. */
1303 }
1305 /* If the base class is not empty or nearly empty, then this
1306 class cannot be nearly empty. */
1309 /* A lot of properties from the bases also apply to the derived
1310 class. */
1323 }
1324 }
1326 /* Binfo FROM is within a virtual hierarchy which is being reseated to
1327 TO. Move primary information from FROM to TO, and recursively traverse
1328 into FROM's bases. The hierarchy is dominated by TYPE. MAPPINGS is an
1329 assoc list of binfos that have already been reseated. */
1331 static void
1333 tree to;
1334 tree from;
1335 tree type;
1336 tree mappings;
1337 {
1349 {
1351 tree assoc;
1353 /* We might have just moved the primary base too, see if it's on our
1354 mappings. */
1360 }
1367 {
1373 }
1376 {
1381 {
1384 /* This base is a primary of some binfo we have already
1385 reseated. We must reseat this one too. */
1387 }
1388 else
1390 }
1391 }
1393 /* FROM is the canonical binfo for a virtual base. It is being reseated to
1394 make TO the canonical binfo, within the hierarchy dominated by TYPE.
1395 MAPPINGS is an assoc list of binfos that have already been reseated.
1396 Adjust any non-virtual bases within FROM, and also move any virtual bases
1397 which are canonical. This complication arises because selecting primary
1398 bases walks in inheritance graph order, but we don't share binfos for
1399 virtual bases, hence we can fill in the primaries for a virtual base,
1400 and then discover that a later base requires the virtual as its
1401 primary. */
1403 static void
1405 tree to;
1406 tree from;
1407 tree type;
1408 tree mappings;
1409 {
1413 {
1416 }
1417 }
1419 /* Make BASE_BINFO the a primary virtual base within the hierarchy
1420 dominated by TYPE. Returns BASE_BINFO, if it is not already one, NULL
1421 otherwise (because something else has already made it primary). */
1423 static tree
1425 tree base_binfo;
1426 tree type;
1427 {
1431 {
1432 /* It's already allocated in the hierarchy. BINFO won't have a
1433 primary base in this hierarchy, even though the complete object
1434 BINFO is for, would do. */
1436 }
1438 /* We need to make sure that the assoc list
1439 CLASSTYPE_VBASECLASSES of TYPE, indicates this particular
1440 primary BINFO for the virtual base, as this is the one
1441 that'll really exist. */
1446 }
1448 /* If BINFO is an unmarked virtual binfo for a class with a primary virtual
1449 base, then BINFO has no primary base in this graph. Called from
1450 mark_primary_bases. DATA is the most derived type. */
1453 tree binfo;
1455 {
1460 {
1461 /* This morally virtual base has a primary base when it
1462 is a complete object. We need to locate the shared instance
1463 of this binfo in the type dominated by T. We duplicate the
1464 primary base information from there to here. */
1465 tree vbase;
1466 tree unshared_base;
1473 t));
1478 }
1481 /* The vtable fields will have been copied when duplicating the
1482 base binfos. That information is bogus, make sure we don't try
1483 and use it. */
1486 /* If this is a virtual primary base, make sure its offset matches
1487 that which it is primary for. */
1490 {
1495 }
1499 }
1501 /* Set BINFO_PRIMARY_BASE_OF for all binfos in the hierarchy
1502 dominated by TYPE that are primary bases. */
1504 static void
1506 tree type;
1507 {
1508 tree binfo;
1510 /* Walk the bases in inheritance graph order. */
1512 {
1513 tree base_binfo;
1516 /* Not a dynamic base. */
1526 else
1530 }
1531 /* There could remain unshared morally virtual bases which were not
1532 visited in the inheritance graph walk. These bases will have lost
1533 their virtual primary base (should they have one). We must now
1534 find them. Also we must fix up the BINFO_OFFSETs of primary
1535 virtual bases. We could not do that as we went along, as they
1536 were originally copied from the bases we inherited from by
1537 unshare_base_binfos. That may have decided differently about
1538 where a virtual primary base went. */
1540 }
1542 /* Make the BINFO the primary base of T. */
1544 static void
1546 tree t;
1547 tree binfo;
1548 {
1549 tree basetype;
1556 }
1558 /* Determine the primary class for T. */
1560 static void
1562 tree t;
1563 {
1565 tree vbases;
1566 tree type_binfo;
1568 /* If there are no baseclasses, there is certainly no primary base. */
1575 {
1580 {
1581 /* We prefer a non-virtual base, although a virtual one will
1582 do. */
1587 {
1590 }
1591 else
1592 {
1593 tree vfields;
1595 /* Only add unique vfields, and flatten them out as we go. */
1597 vfields;
1605 }
1606 }
1607 }
1612 /* Find the indirect primary bases - those virtual bases which are primary
1613 bases of something else in this hierarchy. */
1615 vbases;
1617 {
1620 /* See if this virtual base is an indirect primary base. To be so,
1621 it must be a primary base within the hierarchy of one of our
1622 direct bases. */
1624 {
1626 tree v;
1629 v;
1631 {
1637 {
1640 }
1641 }
1643 /* If we've discovered that this virtual base is an indirect
1644 primary base, then we can move on to the next virtual
1645 base. */
1648 }
1649 }
1651 /* A "nearly-empty" virtual base class can be the primary base
1652 class, if no non-virtual polymorphic base can be found. */
1654 {
1655 /* If not NULL, this is the best primary base candidate we have
1656 found so far. */
1658 tree base_binfo;
1660 /* Loop over the baseclasses. */
1662 base_binfo;
1664 {
1669 {
1670 /* If this is not an indirect primary base, then it's
1671 definitely our primary base. */
1673 {
1676 }
1678 /* If this is an indirect primary base, it still could be
1679 our primary base -- unless we later find there's another
1680 nearly-empty virtual base that isn't an indirect
1681 primary base. */
1684 }
1685 }
1687 /* If we've got a primary base, use it. */
1689 {
1693 }
1694 }
1696 /* Mark the primary base classes at this point. */
1698 }
1699 \f
1700 /* Set memoizing fields and bits of T (and its variants) for later
1701 use. */
1703 static void
1705 tree t;
1706 {
1709 /* Fix up variants (if any). */
1712 {
1713 /* These fields are in the _TYPE part of the node, not in
1714 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1725 /* Copy whatever these are holding today. */
1732 }
1735 /* For a class w/o baseclasses, `finish_struct' has set
1736 CLASS_TYPE_ABSTRACT_VIRTUALS correctly (by
1737 definition). Similarly for a class whose base classes do not
1738 have vtables. When neither of these is true, we might have
1739 removed abstract virtuals (by providing a definition), added
1740 some (by declaring new ones), or redeclared ones from a base
1741 class. We need to recalculate what's really an abstract virtual
1742 at this point (by looking in the vtables). */
1746 {
1747 /* Notice whether this class has type conversion functions defined. */
1750 tree basetype;
1753 {
1757 }
1758 }
1760 /* If this type has a copy constructor or a destructor, force its mode to
1761 be BLKmode, and force its TREE_ADDRESSABLE bit to be nonzero. This
1762 will cause it to be passed by invisible reference and prevent it from
1763 being returned in a register. */
1765 {
1766 tree variants;
1769 {
1772 }
1773 }
1774 }
1776 /* Issue warnings about T having private constructors, but no friends,
1777 and so forth.
1779 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1780 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1781 non-private static member functions. */
1783 static void
1785 tree t;
1786 {
1789 tree fn;
1792 /* If the class has friends, those entities might create and
1793 access instances, so we should not warn. */
1796 /* We will have warned when the template was declared; there's
1797 no need to warn on every instantiation. */
1799 /* There's no reason to even consider warning about this
1800 class. */
1803 /* We only issue one warning, if more than one applies, because
1804 otherwise, on code like:
1806 class A {
1807 // Oops - forgot `public:'
1808 A();
1809 A(const A&);
1810 ~A();
1811 };
1813 we warn several times about essentially the same problem. */
1815 /* Check to see if all (non-constructor, non-destructor) member
1816 functions are private. (Since there are no friends or
1817 non-private statics, we can't ever call any of the private member
1818 functions.) */
1820 /* We're not interested in compiler-generated methods; they don't
1821 provide any way to call private members. */
1823 {
1825 {
1827 /* A non-private static member function is just like a
1828 friend; it can create and invoke private member
1829 functions, and be accessed without a class
1830 instance. */
1835 }
1838 }
1841 {
1842 /* There are no non-private methods, and there's at least one
1843 private member function that isn't a constructor or
1844 destructor. (If all the private members are
1845 constructors/destructors we want to use the code below that
1846 issues error messages specifically referring to
1847 constructors/destructors.) */
1853 {
1856 }
1858 {
1861 }
1862 }
1864 /* Even if some of the member functions are non-private, the class
1865 won't be useful for much if all the constructors or destructors
1866 are private: such an object can never be created or destroyed. */
1868 {
1872 {
1874 t);
1876 }
1877 }
1880 {
1883 /* If a non-template class does not define a copy
1884 constructor, one is defined for it, enabling it to avoid
1885 this warning. For a template class, this does not
1886 happen, and so we would normally get a warning on:
1888 template <class T> class C { private: C(); };
1890 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1891 complete non-template or fully instantiated classes have this
1892 flag set. */
1895 else
1897 fn;
1899 {
1901 /* Ideally, we wouldn't count copy constructors (or, in
1902 fact, any constructor that takes an argument of the
1903 class type as a parameter) because such things cannot
1904 be used to construct an instance of the class unless
1905 you already have one. But, for now at least, we're
1906 more generous. */
1908 {
1911 }
1912 }
1915 {
1917 t);
1919 }
1920 }
1921 }
1923 /* Function to help qsort sort FIELD_DECLs by name order. */
1925 static int
1928 {
1930 /* A nontype is "greater" than a type. */
1939 }
1941 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1943 static int
1946 {
1956 }
1958 /* Warn about duplicate methods in fn_fields. Also compact method
1959 lists so that lookup can be made faster.
1961 Data Structure: List of method lists. The outer list is a
1962 TREE_LIST, whose TREE_PURPOSE field is the field name and the
1963 TREE_VALUE is the DECL_CHAIN of the FUNCTION_DECLs. TREE_CHAIN
1964 links the entire list of methods for TYPE_METHODS. Friends are
1965 chained in the same way as member functions (? TREE_CHAIN or
1966 DECL_CHAIN), but they live in the TREE_TYPE field of the outer
1967 list. That allows them to be quickly deleted, and requires no
1968 extra storage.
1970 Sort methods that are not special (i.e., constructors, destructors,
1971 and type conversion operators) so that we can find them faster in
1972 search. */
1974 static void
1976 tree t;
1977 {
1978 tree fn_fields;
1979 tree method_vec;
1983 {
1984 /* Clear these for safety; perhaps some parsing error could set
1985 these incorrectly. */
1990 }
1996 /* First fill in entry 0 with the constructors, entry 1 with destructors,
1997 and the next few with type conversion operators (if any). */
2000 /* Clear out this flag. */
2004 /* We thought there was a destructor, but there wasn't. Some
2005 parse errors cause this anomalous situation. */
2008 /* Issue warnings about private constructors and such. If there are
2009 no methods, then some public defaults are generated. */
2012 /* Now sort the methods. */
2014 len--;
2017 /* The type conversion ops have to live at the front of the vec, so we
2018 can't sort them. */
2020 {
2025 }
2029 }
2031 /* Emit error when a duplicate definition of a type is seen. Patch up. */
2033 void
2035 tree t;
2036 {
2040 /* Pretend we haven't defined this type. */
2042 /* All of the component_decl's were TREE_CHAINed together in the parser.
2043 finish_struct_methods walks these chains and assembles all methods with
2044 the same base name into DECL_CHAINs. Now we don't need the parser chains
2045 anymore, so we unravel them. */
2047 /* This used to be in finish_struct, but it turns out that the
2048 TREE_CHAIN is used by dbxout_type_methods and perhaps some other
2049 things... */
2051 {
2055 {
2058 {
2061 }
2062 }
2063 }
2066 {
2084 }
2092 /* Clear TYPE_LANG_FLAGS -- those in TYPE_LANG_SPECIFIC are cleared above. */
2100 /* But not this one. */
2102 }
2104 /* Make BINFO's vtable have N entries, including RTTI entries,
2105 vbase and vcall offsets, etc. Set its type and call the backend
2106 to lay it out. */
2108 static void
2110 tree binfo;
2112 {
2113 tree atype;
2114 tree vtable;
2120 /* We may have to grow the vtable. */
2123 {
2128 /* At one time the vtable info was grabbed 2 words at a time. This
2129 fails on SPARC unless you have 8-byte alignment. */
2132 }
2133 }
2135 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2136 have the same signature. */
2138 int
2141 {
2142 /* One destructor overrides another if they are the same kind of
2143 destructor. */
2147 /* But a non-destructor never overrides a destructor, nor vice
2148 versa, nor do different kinds of destructors override
2149 one-another. For example, a complete object destructor does not
2150 override a deleting destructor. */
2155 {
2163 }
2165 }
2167 /* Called from base_derived_from via dfs_walk. */
2169 static tree
2171 {
2179 }
2181 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2182 subobject. */
2184 static bool
2186 {
2188 }
2191 /* The function for which we are trying to find a final overrider. */
2192 tree fn;
2193 /* The base class in which the function was declared. */
2194 tree declaring_base;
2195 /* The most derived class in the hierarchy. */
2196 tree most_derived_type;
2197 /* The candidate overriders. */
2198 tree candidates;
2201 /* Called from find_final_overrider via dfs_walk. */
2203 static tree
2205 tree binfo;
2207 {
2214 {
2215 tree path;
2216 tree method;
2218 /* We haven't found an overrider yet. */
2220 /* We've found a path to the declaring base. Walk down the path
2221 looking for an overrider for FN. */
2223 path;
2225 {
2229 {
2232 }
2233 }
2235 /* If we found an overrider, record the overriding function, and
2236 the base from which it came. */
2238 {
2241 /* Remove any candidates overridden by this new function. */
2244 {
2245 /* If *CANDIDATE overrides METHOD, then METHOD
2246 cannot override anything else on the list. */
2249 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2252 else
2254 }
2256 /* Add the new function. */
2258 }
2259 }
2262 }
2264 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2265 FN and whose TREE_VALUE is the binfo for the base where the
2266 overriding occurs. BINFO (in the hierarchy dominated by T) is the
2267 base object in which FN is declared. */
2269 static tree
2271 tree t;
2272 tree binfo;
2273 tree fn;
2274 {
2275 find_final_overrider_data ffod;
2277 /* Getting this right is a little tricky. This is valid:
2279 struct S { virtual void f (); };
2280 struct T { virtual void f (); };
2281 struct U : public S, public T { };
2283 even though calling `f' in `U' is ambiguous. But,
2285 struct R { virtual void f(); };
2286 struct S : virtual public R { virtual void f (); };
2287 struct T : virtual public R { virtual void f (); };
2288 struct U : public S, public T { };
2290 is not -- there's no way to decide whether to put `S::f' or
2291 `T::f' in the vtable for `R'.
2293 The solution is to look at all paths to BINFO. If we find
2294 different overriders along any two, then there is a problem. */
2301 dfs_find_final_overrider,
2302 NULL,
2305 /* If there was no winner, issue an error message. */
2307 {
2310 }
2313 }
2315 /* Return the index of the vcall offset for FN when TYPE is used as a
2316 virtual base. */
2318 static tree
2320 {
2321 tree v;
2328 /* There should always be an appropriate index. */
2332 }
2334 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2335 dominated by T. FN has been overriden in BINFO; VIRTUALS points to the
2336 corresponding position in the BINFO_VIRTUALS list. */
2338 static void
2340 tree t;
2341 tree binfo;
2342 tree fn;
2344 {
2345 tree b;
2346 tree overrider;
2347 tree delta;
2348 tree virtual_base;
2349 tree first_defn;
2352 /* Find the nearest primary base (possibly binfo itself) which defines
2353 this function; this is the class the caller will convert to when
2354 calling FN through BINFO. */
2356 {
2360 /* The nearest definition is from a lost primary. */
2363 }
2366 /* Find the final overrider. */
2371 /* Check for unsupported covariant returns again now that we've
2372 calculated the base offsets. */
2375 /* Assume that we will produce a thunk that convert all the way to
2376 the final overrider, and not to an intermediate virtual base. */
2379 /* See if we can convert to an intermediate virtual base first, and then
2380 use the vcall offset located there to finish the conversion. */
2382 {
2383 /* If we find the final overrider, then we can stop
2384 walking. */
2389 /* If we find a virtual base, and we haven't yet found the
2390 overrider, then there is a virtual base between the
2391 declaring base (first_defn) and the final overrider. */
2394 }
2396 /* Compute the constant adjustment to the `this' pointer. The
2397 `this' pointer, when this function is called, will point at BINFO
2398 (or one of its primary bases, which are at the same offset). */
2400 /* The `this' pointer needs to be adjusted from the declaration to
2401 the nearest virtual base. */
2405 /* If the nearest definition is in a lost primary, we don't need an
2406 entry in our vtable. Except possibly in a constructor vtable,
2407 if we happen to get our primary back. In that case, the offset
2408 will be zero, as it will be a primary base. */
2410 else
2411 /* The `this' pointer needs to be adjusted from pointing to
2412 BINFO to pointing at the base where the final overrider
2413 appears. */
2418 binfo,
2420 delta,
2421 virtuals);
2427 }
2429 /* Called from modify_all_vtables via dfs_walk. */
2431 static tree
2433 tree binfo;
2435 {
2437 primary base; we're not going to use that vtable anyhow.
2438 We do still need to do this for virtual primary bases, as they
2439 could become non-primary in a construction vtable. */
2441 /* Similarly, a base without a vtable needs no modification. */
2443 {
2444 tree t;
2445 tree virtuals;
2446 tree old_virtuals;
2452 /* Now, go through each of the virtual functions in the virtual
2453 function table for BINFO. Find the final overrider, and
2454 update the BINFO_VIRTUALS list appropriately. */
2457 virtuals;
2461 binfo,
2464 }
2469 }
2471 /* Update all of the primary and secondary vtables for T. Create new
2472 vtables as required, and initialize their RTTI information. Each
2473 of the functions in VIRTUALS is declared in T and may override a
2474 virtual function from a base class; find and modify the appropriate
2475 entries to point to the overriding functions. Returns a list, in
2476 declaration order, of the virtual functions that are declared in T,
2477 but do not appear in the primary base class vtable, and which
2478 should therefore be appended to the end of the vtable for T. */
2480 static tree
2482 tree t;
2483 tree virtuals;
2484 {
2488 /* Update all of the vtables. */
2490 dfs_modify_vtables,
2491 dfs_unmarked_real_bases_queue_p,
2492 t);
2495 /* Add virtual functions not already in our primary vtable. These
2496 will be both those introduced by this class, and those overridden
2497 from secondary bases. It does not include virtuals merely
2498 inherited from secondary bases. */
2500 {
2505 {
2506 /* We don't need to adjust the `this' pointer when
2507 calling this function. */
2511 /* This is a function not already in our vtable. Keep it. */
2513 }
2514 else
2515 /* We've already got an entry for this function. Skip it. */
2517 }
2520 }
2522 /* Get the base virtual function declarations in T that have the
2523 indicated NAME. */
2525 static tree
2528 {
2529 tree methods;
2544 {
2547 base_fndecls);
2548 }
2551 }
2553 /* If this declaration supersedes the declaration of
2554 a method declared virtual in the base class, then
2555 mark this field as being virtual as well. */
2557 static void
2560 {
2562 /* In [temp.mem] we have:
2564 A specialization of a member function template does not
2565 override a virtual function from a base class. */
2571 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2572 the error_mark_node so that we know it is an overriding
2573 function. */
2577 {
2581 }
2582 }
2584 /* Warn about hidden virtual functions that are not overridden in t.
2585 We know that constructors and destructors don't apply. */
2587 void
2589 tree t;
2590 {
2595 /* We go through each separately named virtual function. */
2597 {
2598 tree fns;
2599 tree name;
2600 tree fndecl;
2601 tree base_fndecls;
2604 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2605 have the same name. Figure out what name that is. */
2607 /* There are no possibly hidden functions yet. */
2609 /* Iterate through all of the base classes looking for possibly
2610 hidden functions. */
2612 {
2615 base_fndecls);
2616 }
2618 /* If there are no functions to hide, continue. */
2622 /* Remove any overridden functions. */
2624 {
2627 {
2631 /* If the method from the base class has the same
2632 signature as the method from the derived class, it
2633 has been overridden. */
2636 else
2638 }
2639 }
2641 /* Now give a warning for all base functions without overriders,
2642 as they are hidden. */
2644 {
2645 /* Here we know it is a hider, and no overrider exists. */
2650 }
2651 }
2652 }
2654 /* Check for things that are invalid. There are probably plenty of other
2655 things we should check for also. */
2657 static void
2659 tree t;
2660 {
2661 tree field;
2664 {
2672 {
2675 {
2676 /* We're generally only interested in entities the user
2677 declared, but we also find nested classes by noticing
2678 the TYPE_DECL that we create implicitly. You're
2679 allowed to put one anonymous union inside another,
2680 though, so we explicitly tolerate that. We use
2681 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2682 we also allow unnamed types used for defining fields. */
2690 elt);
2693 {
2695 elt);
2697 }
2701 elt);
2704 elt);
2708 }
2709 }
2710 }
2711 }
2713 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2714 will be used later during class template instantiation.
2715 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2716 a non-static member data (FIELD_DECL), a member function
2717 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2718 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2719 When FRIEND_P is nonzero, T is either a friend class
2720 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2721 (FUNCTION_DECL, TEMPLATE_DECL). */
2723 void
2725 tree type;
2726 tree t;
2728 {
2729 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2734 }
2736 /* Create default constructors, assignment operators, and so forth for
2737 the type indicated by T, if they are needed.
2738 CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2739 CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2740 class cannot have a default constructor, copy constructor taking a
2741 const reference argument, or an assignment operator taking a const
2742 reference, respectively. If a virtual destructor is created, its
2743 DECL is returned; otherwise the return value is NULL_TREE. */
2745 static tree
2747 cant_have_const_cctor,
2748 cant_have_const_assignment)
2749 tree t;
2753 {
2754 tree default_fn;
2761 /* Destructor. */
2763 {
2767 /* If we couldn't make it work, then pretend we didn't need it. */
2770 else
2771 {
2777 }
2778 }
2779 else
2780 /* Any non-implicit destructor is non-trivial. */
2783 /* Default constructor. */
2785 {
2789 }
2791 /* Copy constructor. */
2793 {
2794 /* ARM 12.18: You get either X(X&) or X(const X&), but
2795 not both. --Chip */
2796 default_fn
2801 }
2803 /* Assignment operator. */
2805 {
2806 default_fn
2811 }
2813 /* Now, hook all of the new functions on to TYPE_METHODS,
2814 and add them to the CLASSTYPE_METHOD_VEC. */
2816 {
2819 }
2826 }
2828 /* Subroutine of finish_struct_1. Recursively count the number of fields
2829 in TYPE, including anonymous union members. */
2831 static int
2833 tree fields;
2834 {
2835 tree x;
2838 {
2841 else
2843 }
2845 }
2847 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2848 TREE_LIST FIELDS to the TREE_VEC FIELD_VEC, starting at offset IDX. */
2850 static int
2854 {
2855 tree x;
2857 {
2860 else
2862 }
2864 }
2866 /* FIELD is a bit-field. We are finishing the processing for its
2867 enclosing type. Issue any appropriate messages and set appropriate
2868 flags. */
2870 static void
2872 tree field;
2873 {
2877 /* Detect invalid bit-field type. */
2880 {
2883 }
2885 /* Detect and ignore out of range field width. */
2887 {
2890 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2893 /* detect invalid field size. */
2896 else
2900 {
2902 field);
2904 }
2906 {
2909 }
2911 {
2914 }
2924 min_precision
2929 }
2931 /* Remove the bit-field width indicator so that the rest of the
2932 compiler does not treat that value as an initializer. */
2936 {
2942 {
2943 #ifdef EMPTY_FIELD_BOUNDARY
2945 EMPTY_FIELD_BOUNDARY);
2946 #endif
2947 #ifdef PCC_BITFIELD_TYPE_MATTERS
2949 {
2953 }
2954 #endif
2955 }
2956 }
2957 else
2958 {
2959 /* Non-bit-fields are aligned for their type. */
2964 }
2965 }
2967 /* FIELD is a non bit-field. We are finishing the processing for its
2968 enclosing type T. Issue any appropriate messages and set appropriate
2969 flags. */
2971 static void
2974 any_default_members)
2975 tree field;
2976 tree t;
2981 {
2984 /* An anonymous union cannot contain any fields which would change
2985 the settings of CANT_HAVE_CONST_CTOR and friends. */
2987 ;
2988 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2989 structs. So, we recurse through their fields here. */
2991 {
2992 tree fields;
2998 any_default_members);
2999 }
3000 /* Check members with class type for constructors, destructors,
3001 etc. */
3003 {
3004 /* Never let anything with uninheritable virtuals
3005 make it through without complaint. */
3009 {
3012 field);
3015 field);
3018 field);
3019 }
3020 else
3021 {
3027 }
3038 }
3040 {
3041 /* `build_class_init_list' does not recognize
3042 non-FIELD_DECLs. */
3046 }
3048 /* Non-bit-fields are aligned for their type, except packed fields
3049 which require only BITS_PER_UNIT alignment. */
3052 ? BITS_PER_UNIT
3056 }
3058 /* Check the data members (both static and non-static), class-scoped
3059 typedefs, etc., appearing in the declaration of T. Issue
3060 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3061 declaration order) of access declarations; each TREE_VALUE in this
3062 list is a USING_DECL.
3064 In addition, set the following flags:
3066 EMPTY_P
3067 The class is empty, i.e., contains no non-static data members.
3069 CANT_HAVE_DEFAULT_CTOR_P
3070 This class cannot have an implicitly generated default
3071 constructor.
3073 CANT_HAVE_CONST_CTOR_P
3074 This class cannot have an implicitly generated copy constructor
3075 taking a const reference.
3077 CANT_HAVE_CONST_ASN_REF
3078 This class cannot have an implicitly generated assignment
3079 operator taking a const reference.
3081 All of these flags should be initialized before calling this
3082 function.
3084 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3085 fields can be added by adding to this chain. */
3087 static void
3092 {
3098 /* First, delete any duplicate fields. */
3101 /* Assume there are no access declarations. */
3103 /* Assume this class has no pointer members. */
3105 /* Assume none of the members of this class have default
3106 initializations. */
3110 {
3117 {
3121 /* We don't treat zero-width bitfields as making a class
3122 non-empty. */
3123 ;
3124 else
3125 {
3126 tree element_type;
3128 /* The class is non-empty. */
3130 /* The class is not even nearly empty. */
3132 /* If one of the data members contains an empty class,
3133 so does T. */
3138 }
3139 }
3142 {
3143 /* Prune the access declaration from the list of fields. */
3146 /* Save the access declarations for our caller. */
3149 /* Since we've reset *FIELD there's no reason to skip to the
3150 next field. */
3153 }
3159 /* If we've gotten this far, it's a data member, possibly static,
3160 or an enumerator. */
3164 /* ``A local class cannot have static data members.'' ARM 9.4 */
3168 /* Perform error checking that did not get done in
3169 grokdeclarator. */
3171 {
3173 x);
3176 }
3178 {
3182 }
3184 {
3188 }
3193 /* When this goes into scope, it will be a non-local reference. */
3200 {
3202 /* Unions cannot have static members. */
3206 }
3208 /* Now it can only be a FIELD_DECL. */
3213 /* If this is of reference type, check if it needs an init.
3214 Also do a little ANSI jig if necessary. */
3216 {
3221 /* ARM $12.6.2: [A member initializer list] (or, for an
3222 aggregate, initialization by a brace-enclosed list) is the
3223 only way to initialize nonstatic const and reference
3224 members. */
3231 }
3242 /* DR 148 now allows pointers to members (which are POD themselves),
3243 to be allowed in POD structs. */
3249 /* If any field is const, the structure type is pseudo-const. */
3251 {
3256 /* ARM $12.6.2: [A member initializer list] (or, for an
3257 aggregate, initialization by a brace-enclosed list) is the
3258 only way to initialize nonstatic const and reference
3259 members. */
3266 }
3267 /* A field that is pseudo-const makes the structure likewise. */
3269 {
3274 }
3276 /* Core issue 80: A nonstatic data member is required to have a
3277 different name from the class iff the class has a
3278 user-defined constructor. */
3283 /* We set DECL_C_BIT_FIELD in grokbitfield.
3284 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3287 else
3289 cant_have_const_ctor_p,
3290 cant_have_default_ctor_p,
3291 no_const_asn_ref_p,
3293 }
3295 /* Effective C++ rule 11. */
3298 {
3302 {
3306 }
3309 }
3312 /* Check anonymous struct/anonymous union fields. */
3315 /* We've built up the list of access declarations in reverse order.
3316 Fix that now. */
3318 }
3320 /* If TYPE is an empty class type, records its OFFSET in the table of
3321 OFFSETS. */
3323 static int
3325 tree type;
3326 tree offset;
3327 splay_tree offsets;
3328 {
3329 splay_tree_node n;
3334 /* Record the location of this empty object in OFFSETS. */
3342 type,
3346 }
3348 /* Returns nonzero if TYPE is an empty class type and there is
3349 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3351 static int
3353 tree type;
3354 tree offset;
3355 splay_tree offsets;
3356 {
3357 splay_tree_node n;
3358 tree t;
3363 /* Record the location of this empty object in OFFSETS. */
3373 }
3375 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3376 F for every subobject, passing it the type, offset, and table of
3377 OFFSETS. If VBASES_P is nonzero, then even virtual non-primary
3378 bases should be traversed; otherwise, they are ignored.
3380 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3381 than MAX_OFFSET will not be walked.
3383 If F returns a nonzero value, the traversal ceases, and that value
3384 is returned. Otherwise, returns zero. */
3386 static int
3388 tree type;
3389 subobject_offset_fn f;
3390 tree offset;
3391 splay_tree offsets;
3392 tree max_offset;
3394 {
3397 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3398 stop. */
3403 {
3404 tree field;
3405 tree binfo;
3408 /* Avoid recursing into objects that are not interesting. */
3412 /* Record the location of TYPE. */
3417 /* Iterate through the direct base classes of TYPE. */
3419 {
3432 f,
3434 offset,
3436 offsets,
3437 max_offset,
3442 }
3444 /* Iterate through the virtual base classes of TYPE. In G++
3445 3.2, we included virtual bases in the direct base class loop
3446 above, which results in incorrect results; the correct
3447 offsets for virtual bases are only known when working with
3448 the most derived type. */
3450 {
3451 tree vbase;
3454 vbase;
3456 {
3459 f,
3461 offset,
3463 offsets,
3464 max_offset,
3466 }
3467 }
3469 /* Iterate through the fields of TYPE. */
3472 {
3473 tree field_offset;
3477 else
3478 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3482 f,
3484 offset,
3485 field_offset),
3486 offsets,
3487 max_offset,
3491 }
3492 }
3494 {
3497 tree index;
3499 /* Avoid recursing into objects that are not interesting. */
3504 /* Step through each of the elements in the array. */
3506 /* G++ 3.2 had an off-by-one error here. */
3511 {
3513 f,
3514 offset,
3515 offsets,
3516 max_offset,
3522 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3523 there's no point in iterating through the remaining
3524 elements of the array. */
3527 }
3528 }
3531 }
3533 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3534 OFFSETS. If VBASES_P is nonzero, virtual bases of TYPE are
3535 examined. */
3537 static void
3539 tree type;
3540 tree offset;
3541 splay_tree offsets;
3543 {
3546 }
3548 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3549 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3550 virtual bases of TYPE are examined. */
3552 static int
3554 tree type;
3555 tree offset;
3556 splay_tree offsets;
3558 {
3559 splay_tree_node max_node;
3561 /* Get the node in OFFSETS that indicates the maximum offset where
3562 an empty subobject is located. */
3564 /* If there aren't any empty subobjects, then there's no point in
3565 performing this check. */
3571 vbases_p);
3572 }
3574 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3575 non-static data member of the type indicated by RLI. BINFO is the
3576 binfo corresponding to the base subobject, OFFSETS maps offsets to
3577 types already located at those offsets. This function determines
3578 the position of the DECL. */
3580 static void
3582 tree decl,
3583 tree binfo,
3584 splay_tree offsets)
3585 {
3589 tree type;
3592 {
3593 /* For the purposes of determining layout conflicts, we want to
3594 use the class type of BINFO; TREE_TYPE (DECL) will be the
3595 CLASSTYPE_AS_BASE version, which does not contain entries for
3596 zero-sized bases. */
3599 }
3600 else
3601 {
3604 }
3606 /* Try to place the field. It may take more than one try if we have
3607 a hard time placing the field without putting two objects of the
3608 same type at the same address. */
3610 {
3613 /* Place this field. */
3617 /* We have to check to see whether or not there is already
3618 something of the same type at the offset we're about to use.
3619 For example:
3621 struct S {};
3622 struct T : public S { int i; };
3623 struct U : public S, public T {};
3625 Here, we put S at offset zero in U. Then, we can't put T at
3626 offset zero -- its S component would be at the same address
3627 as the S we already allocated. So, we have to skip ahead.
3628 Since all data members, including those whose type is an
3629 empty class, have nonzero size, any overlap can happen only
3630 with a direct or indirect base-class -- it can't happen with
3631 a data member. */
3632 /* G++ 3.2 did not check for overlaps when placing a non-empty
3633 virtual base. */
3637 {
3638 /* Strip off the size allocated to this field. That puts us
3639 at the first place we could have put the field with
3640 proper alignment. */
3643 /* Bump up by the alignment required for the type. */
3644 rli->bitpos
3650 }
3651 else
3652 /* There was no conflict. We're done laying out this field. */
3654 }
3656 /* Now that we know where it will be placed, update its
3657 BINFO_OFFSET. */
3659 /* Indirect virtual bases may have a non-zero BINFO_OFFSET at
3660 this point because their BINFO_OFFSET is copied from another
3661 hierarchy. Therefore, we may not need to add the entire
3662 OFFSET. */
3667 t);
3668 }
3670 /* Returns true if TYPE is empty and OFFSET is non-zero. */
3672 static int
3674 tree offset,
3675 splay_tree offsets ATTRIBUTE_UNUSED)
3676 {
3678 }
3680 /* Layout the empty base BINFO. EOC indicates the byte currently just
3681 past the end of the class, and should be correctly aligned for a
3682 class of the type indicated by BINFO; OFFSETS gives the offsets of
3683 the empty bases allocated so far. T is the most derived
3684 type. Return nonzero iff we added it at the end. */
3686 static bool
3688 tree binfo;
3689 tree eoc;
3690 splay_tree offsets;
3691 tree t;
3692 {
3693 tree alignment;
3697 /* This routine should only be used for empty classes. */
3708 /* This is an empty base class. We first try to put it at offset
3709 zero. */
3712 offsets,
3714 {
3715 /* That didn't work. Now, we move forward from the next
3716 available spot in the class. */
3720 {
3723 offsets,
3725 /* We finally found a spot where there's no overlap. */
3728 /* There's overlap here, too. Bump along to the next spot. */
3730 }
3731 }
3733 }
3735 /* Layout the the base given by BINFO in the class indicated by RLI.
3736 *BASE_ALIGN is a running maximum of the alignments of
3737 any base class. OFFSETS gives the location of empty base
3738 subobjects. T is the most derived type. Return nonzero if the new
3739 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3740 *NEXT_FIELD, unless BINFO is for an empty base class.
3742 Returns the location at which the next field should be inserted. */
3747 {
3752 /* This error is now reported in xref_tag, thus giving better
3753 location information. */
3756 /* Place the base class. */
3758 {
3759 tree decl;
3761 /* The containing class is non-empty because it has a non-empty
3762 base class. */
3765 /* Create the FIELD_DECL. */
3773 /* Tell the backend not to round up to TYPE_ALIGN. */
3776 /* Try to place the field. It may take more than one try if we
3777 have a hard time placing the field without putting two
3778 objects of the same type at the same address. */
3780 /* Add the new FIELD_DECL to the list of fields for T. */
3784 }
3785 else
3786 {
3787 tree eoc;
3790 /* On some platforms (ARM), even empty classes will not be
3791 byte-aligned. */
3795 /* A nearly-empty class "has no proper base class that is empty,
3796 not morally virtual, and at an offset other than zero." */
3798 {
3801 /* The check above (used in G++ 3.2) is insufficient because
3802 an empty class placed at offset zero might itself have an
3803 empty base at a non-zero offset. */
3805 empty_base_at_nonzero_offset_p,
3806 size_zero_node,
3810 {
3816 }
3817 }
3819 /* We do not create a FIELD_DECL for empty base classes because
3820 it might overlap some other field. We want to be able to
3821 create CONSTRUCTORs for the class by iterating over the
3822 FIELD_DECLs, and the back end does not handle overlapping
3823 FIELD_DECLs. */
3825 /* An empty virtual base causes a class to be non-empty
3826 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3827 here because that was already done when the virtual table
3828 pointer was created. */
3829 }
3831 /* Record the offsets of BINFO and its base subobjects. */
3834 offsets,
3838 }
3840 /* Layout all of the non-virtual base classes. Record empty
3841 subobjects in OFFSETS. T is the most derived type. Return nonzero
3842 if the type cannot be nearly empty. The fields created
3843 corresponding to the base classes will be inserted at
3844 *NEXT_FIELD. */
3846 static void
3849 {
3850 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3851 subobjects. */
3856 /* The primary base class is always allocated first. */
3861 /* Now allocate the rest of the bases. */
3863 {
3864 tree base_binfo;
3868 /* The primary base was already allocated above, so we don't
3869 need to allocate it again here. */
3873 /* A primary virtual base class is allocated just like any other
3874 base class, but a non-primary virtual base is allocated
3875 later, in layout_virtual_bases. */
3882 }
3883 }
3885 /* Go through the TYPE_METHODS of T issuing any appropriate
3886 diagnostics, figuring out which methods override which other
3887 methods, and so forth. */
3889 static void
3891 tree t;
3892 {
3893 tree x;
3896 {
3897 /* If this was an evil function, don't keep it in class. */
3906 /* The name of the field is the original field name
3907 Save this in auxiliary field for later overloading. */
3909 {
3914 }
3915 }
3916 }
3918 /* FN is a constructor or destructor. Clone the declaration to create
3919 a specialized in-charge or not-in-charge version, as indicated by
3920 NAME. */
3922 static tree
3924 tree fn;
3925 tree name;
3926 {
3927 tree parms;
3928 tree clone;
3930 /* Copy the function. */
3932 /* Remember where this function came from. */
3935 /* Reset the function name. */
3938 /* There's no pending inline data for this function. */
3941 /* And it hasn't yet been deferred. */
3944 /* The base-class destructor is not virtual. */
3946 {
3950 }
3952 /* If there was an in-charge parameter, drop it from the function
3953 type. */
3955 {
3956 tree basetype;
3957 tree parmtypes;
3958 tree exceptions;
3963 /* Skip the `this' parameter. */
3965 /* Skip the in-charge parameter. */
3967 /* And the VTT parm, in a complete [cd]tor. */
3971 /* If this is subobject constructor or destructor, add the vtt
3972 parameter. */
3976 parmtypes);
3979 exceptions);
3980 }
3982 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3983 aren't function parameters; those are the template parameters. */
3985 {
3987 /* Remove the in-charge parameter. */
3989 {
3993 }
3994 /* And the VTT parm, in a complete [cd]tor. */
3996 {
3999 else
4000 {
4004 }
4005 }
4008 {
4011 }
4012 }
4014 /* Create the RTL for this function. */
4018 /* Make it easy to find the CLONE given the FN. */
4022 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
4024 {
4025 tree result;
4032 }
4037 }
4039 /* Produce declarations for all appropriate clones of FN. If
4040 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4041 CLASTYPE_METHOD_VEC as well. */
4043 void
4045 tree fn;
4047 {
4048 tree clone;
4050 /* Avoid inappropriate cloning. */
4056 {
4057 /* For each constructor, we need two variants: an in-charge version
4058 and a not-in-charge version. */
4065 }
4066 else
4067 {
4070 /* For each destructor, we need three variants: an in-charge
4071 version, a not-in-charge version, and an in-charge deleting
4072 version. We clone the deleting version first because that
4073 means it will go second on the TYPE_METHODS list -- and that
4074 corresponds to the correct layout order in the virtual
4075 function table.
4077 For a non-virtual destructor, we do not build a deleting
4078 destructor. */
4080 {
4084 }
4091 }
4093 /* Note that this is an abstract function that is never emitted. */
4095 }
4097 /* DECL is an in charge constructor, which is being defined. This will
4098 have had an in class declaration, from whence clones were
4099 declared. An out-of-class definition can specify additional default
4100 arguments. As it is the clones that are involved in overload
4101 resolution, we must propagate the information from the DECL to its
4102 clones. */
4104 void
4106 tree decl;
4107 {
4108 tree clone;
4112 {
4119 /* Skip the 'this' parameter. */
4135 {
4140 {
4141 /* A default parameter has been added. Adjust the
4142 clone's parameters. */
4145 tree type;
4150 {
4153 clone_parms);
4155 }
4158 clone_parms);
4165 }
4166 }
4168 }
4169 }
4171 /* For each of the constructors and destructors in T, create an
4172 in-charge and not-in-charge variant. */
4174 static void
4176 tree t;
4177 {
4178 tree fns;
4180 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4181 out now. */
4189 }
4191 /* Remove all zero-width bit-fields from T. */
4193 static void
4195 tree t;
4196 {
4201 {
4206 else
4208 }
4209 }
4211 /* Returns TRUE iff we need a cookie when dynamically allocating an
4212 array whose elements have the indicated class TYPE. */
4214 static bool
4216 tree type;
4217 {
4218 tree fns;
4223 /* If there's a non-trivial destructor, we need a cookie. In order
4224 to iterate through the array calling the destructor for each
4225 element, we'll have to know how many elements there are. */
4229 /* If the usual deallocation function is a two-argument whose second
4230 argument is of type `size_t', then we have to pass the size of
4231 the array to the deallocation function, so we will need to store
4232 a cookie. */
4236 /* If there are no `operator []' members, or the lookup is
4237 ambiguous, then we don't need a cookie. */
4240 /* Loop through all of the functions. */
4242 {
4243 tree fn;
4244 tree second_parm;
4246 /* Select the current function. */
4248 /* See if this function is a one-argument delete function. If
4249 it is, then it will be the usual deallocation function. */
4253 /* Otherwise, if we have a two-argument function and the second
4254 argument is `size_t', it will be the usual deallocation
4255 function -- unless there is one-argument function, too. */
4259 }
4262 }
4264 /* Check the validity of the bases and members declared in T. Add any
4265 implicitly-generated functions (like copy-constructors and
4266 assignment operators). Compute various flag bits (like
4267 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4268 level: i.e., independently of the ABI in use. */
4270 static void
4272 {
4273 /* Nonzero if we are not allowed to generate a default constructor
4274 for this case. */
4276 /* Nonzero if the implicitly generated copy constructor should take
4277 a non-const reference argument. */
4279 /* Nonzero if the the implicitly generated assignment operator
4280 should take a non-const reference argument. */
4282 tree access_decls;
4284 /* By default, we use const reference arguments and generate default
4285 constructors. */
4290 /* Check all the base-classes. */
4294 /* Check all the data member declarations. */
4300 /* Check all the method declarations. */
4303 /* A nearly-empty class has to be vptr-containing; a nearly empty
4304 class contains just a vptr. */
4308 /* Do some bookkeeping that will guide the generation of implicitly
4309 declared member functions. */
4327 /* Synthesize any needed methods. Note that methods will be synthesized
4328 for anonymous unions; grok_x_components undoes that. */
4330 cant_have_const_ctor,
4331 no_const_asn_ref);
4333 /* Create the in-charge and not-in-charge variants of constructors
4334 and destructors. */
4337 /* Process the using-declarations. */
4341 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4344 /* Figure out whether or not we will need a cookie when dynamically
4345 allocating an array of this type. */
4348 }
4350 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4351 accordingly. If a new vfield was created (because T doesn't have a
4352 primary base class), then the newly created field is returned. It
4353 is not added to the TYPE_FIELDS list; it is the caller's
4354 responsibility to do that. Accumulate declared virtual functions
4355 on VIRTUALS_P. */
4357 static tree
4359 tree t;
4361 {
4362 tree fn;
4364 /* Collect the virtual functions declared in T. */
4368 {
4376 }
4378 /* If we couldn't find an appropriate base class, create a new field
4379 here. Even if there weren't any new virtual functions, we might need a
4380 new virtual function table if we're supposed to include vptrs in
4381 all classes that need them. */
4383 {
4384 /* We build this decl with vtbl_ptr_type_node, which is a
4385 `vtable_entry_type*'. It might seem more precise to use
4386 `vtable_entry_type (*)[N]' where N is the number of firtual
4387 functions. However, that would require the vtable pointer in
4388 base classes to have a different type than the vtable pointer
4389 in derived classes. We could make that happen, but that
4390 still wouldn't solve all the problems. In particular, the
4391 type-based alias analysis code would decide that assignments
4392 to the base class vtable pointer can't alias assignments to
4393 the derived class vtable pointer, since they have different
4394 types. Thus, in an derived class destructor, where the base
4395 class constructor was inlined, we could generate bad code for
4396 setting up the vtable pointer.
4398 Therefore, we use one type for all vtable pointers. We still
4399 use a type-correct type; it's just doesn't indicate the array
4400 bounds. That's better than using `void*' or some such; it's
4401 cleaner, and it let's the alias analysis code know that these
4402 stores cannot alias stores to void*! */
4403 tree field;
4416 /* This class is non-empty. */
4420 /* If there were any baseclasses, they can't possibly be at
4421 offset zero any more, because that's where the vtable
4422 pointer is. So, converting to a base class is going to
4423 take work. */
4427 }
4430 }
4432 /* Fixup the inline function given by INFO now that the class is
4433 complete. */
4435 static void
4437 tree fn;
4438 {
4440 {
4443 {
4446 }
4447 }
4448 }
4450 /* Fixup the inline methods and friends in TYPE now that TYPE is
4451 complete. */
4453 static void
4455 tree type;
4456 {
4460 {
4465 else
4467 }
4469 /* Do inline member functions. */
4473 /* Do friends. */
4475 method;
4479 }
4481 /* Add OFFSET to all base types of BINFO which is a base in the
4482 hierarchy dominated by T.
4484 OFFSET, which is a type offset, is number of bytes. */
4486 static void
4488 tree binfo;
4489 tree offset;
4490 tree t;
4491 {
4493 tree primary_binfo;
4495 /* Update BINFO's offset. */
4500 offset));
4502 /* Find the primary base class. */
4505 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4506 downwards. */
4508 {
4509 tree base_binfo;
4511 /* On the first time through the loop, do the primary base.
4512 Because the primary base need not be an immediate base, we
4513 must handle the primary base specially. */
4515 {
4520 }
4521 else
4522 {
4524 /* Don't do the primary base twice. */
4527 }
4529 /* Skip virtual bases that aren't our canonical primary base. */
4536 }
4537 }
4539 /* Called via dfs_walk from layout_virtual bases. */
4541 static tree
4543 tree binfo;
4545 {
4546 /* If this is a virtual base, make sure it has the same offset as
4547 the shared copy. If it's a primary base, then we know it's
4548 correct. */
4550 {
4552 tree vbase;
4553 tree offset;
4557 {
4560 }
4561 }
4564 }
4566 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4567 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4568 empty subobjects of T. */
4570 static void
4572 {
4573 tree vbases;
4582 {
4583 /* In G++ 3.2, we incorrectly rounded the size before laying out
4584 the virtual bases. */
4586 #ifdef STRUCTURE_SIZE_BOUNDARY
4587 /* Packed structures don't need to have minimum size. */
4590 #endif
4594 }
4596 /* Find the last field. The artificial fields created for virtual
4597 bases will go after the last extant field to date. */
4602 /* Go through the virtual bases, allocating space for each virtual
4603 base that is not already a primary base class. These are
4604 allocated in inheritance graph order. */
4606 vbases;
4608 {
4609 tree vbase;
4617 {
4620 /* This virtual base is not a primary base of any class in the
4621 hierarchy, so we have to add space for it. */
4625 /* If the first virtual base might have been placed at a
4626 lower address, had we started from CLASSTYPE_SIZE, rather
4627 than TYPE_SIZE, issue a warning. There can be both false
4628 positives and false negatives from this warning in rare
4629 cases; to deal with all the possibilities would probably
4630 require performing both layout algorithms and comparing
4631 the results which is not particularly tractable. */
4633 && first_vbase
4634 && (tree_int_cst_lt
4638 bitsize_unit_node),
4640 warning ("offset of virtual base `%T' is not ABI-compliant and may change in a future version of GCC",
4641 basetype);
4644 }
4645 }
4647 /* Now, go through the TYPE_BINFO hierarchy, setting the
4648 BINFO_OFFSETs correctly for all non-primary copies of the virtual
4649 bases and their direct and indirect bases. The ambiguity checks
4650 in lookup_base depend on the BINFO_OFFSETs being set
4651 correctly. */
4653 }
4655 /* Returns the offset of the byte just past the end of the base class
4656 BINFO. */
4658 static tree
4660 {
4661 tree size;
4664 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4665 allocate some space for it. It cannot have virtual bases, so
4666 TYPE_SIZE_UNIT is fine. */
4668 else
4672 }
4674 /* Returns the offset of the byte just past the end of the base class
4675 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4676 only non-virtual bases are included. */
4678 static tree
4680 tree t;
4682 {
4684 tree binfo;
4685 tree offset;
4689 {
4700 }
4702 /* G++ 3.2 did not check indirect virtual bases. */
4705 binfo;
4707 {
4711 }
4714 }
4716 /* Warn about bases of T that are inaccessible because they are
4717 ambiguous. For example:
4719 struct S {};
4720 struct T : public S {};
4721 struct U : public S, public T {};
4723 Here, `(S*) new U' is not allowed because there are two `S'
4724 subobjects of U. */
4726 static void
4728 tree t;
4729 {
4731 tree vbases;
4732 tree basetype;
4734 /* Check direct bases. */
4736 {
4742 }
4744 /* Check for ambiguous virtual bases. */
4747 vbases;
4749 {
4755 }
4756 }
4758 /* Compare two INTEGER_CSTs K1 and K2. */
4760 static int
4762 splay_tree_key k1;
4763 splay_tree_key k2;
4764 {
4766 }
4768 /* Increase the size indicated in RLI to account for empty classes
4769 that are "off the end" of the class. */
4771 static void
4773 {
4774 tree eoc;
4775 tree rli_size;
4777 /* It might be the case that we grew the class to allocate a
4778 zero-sized base class. That won't be reflected in RLI, yet,
4779 because we are willing to overlay multiple bases at the same
4780 offset. However, now we need to make sure that RLI is big enough
4781 to reflect the entire class. */
4787 {
4789 rli->bitpos
4798 }
4799 }
4801 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4802 BINFO_OFFSETs for all of the base-classes. Position the vtable
4803 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4805 static void
4807 {
4808 tree non_static_data_members;
4809 tree field;
4810 tree vptr;
4811 record_layout_info rli;
4812 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4813 types that appear at that offset. */
4814 splay_tree empty_base_offsets;
4815 /* True if the last field layed out was a bit-field. */
4817 /* The location at which the next field should be inserted. */
4819 /* T, as a base class. */
4820 tree base_t;
4822 /* Keep track of the first non-static data member. */
4825 /* Start laying out the record. */
4828 /* If possible, we reuse the virtual function table pointer from one
4829 of our base classes. */
4832 /* Create a pointer to our virtual function table. */
4835 /* The vptr is always the first thing in the class. */
4837 {
4842 }
4843 else
4846 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4851 /* Layout the non-static data members. */
4853 {
4854 tree type;
4855 tree padding;
4857 /* We still pass things that aren't non-static data members to
4858 the back-end, in case it wants to do something with them. */
4860 {
4862 /* If the static data member has incomplete type, keep track
4863 of it so that it can be completed later. (The handling
4864 of pending statics in finish_record_layout is
4865 insufficient; consider:
4867 struct S1;
4868 struct S2 { static S1 s1; };
4870 At this point, finish_record_layout will be called, but
4871 S1 is still incomplete.) */
4875 }
4879 /* If this field is a bit-field whose width is greater than its
4880 type, then there are some special rules for allocating
4881 it. */
4884 {
4885 integer_type_kind itk;
4886 tree integer_type;
4888 /* We must allocate the bits as if suitably aligned for the
4889 longest integer type that fits in this many bits. type
4890 of the field. Then, we are supposed to use the left over
4891 bits as additional padding. */
4897 /* ITK now indicates a type that is too large for the
4898 field. We have to back up by one to find the largest
4899 type that fits. */
4903 /* In a union, the padding field must have the full width
4904 of the bit-field; all fields start at offset zero. */
4906 else
4907 {
4910 "ABI-compliant and may change in a future "
4912 t);
4915 }
4919 }
4920 else
4924 empty_base_offsets);
4926 /* If a bit-field does not immediately follow another bit-field,
4927 and yet it starts in the middle of a byte, we have failed to
4928 comply with the ABI. */
4931 && !last_field_was_bitfield
4934 bitsize_unit_node)))
4935 cp_warning_at ("offset of `%D' is not ABI-compliant and may change in a future version of GCC",
4936 field);
4938 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4939 offset of the field. */
4945 "classes to be placed at different locations in a "
4947 field);
4949 /* If we needed additional padding after this field, add it
4950 now. */
4952 {
4953 tree padding_field;
4956 NULL_TREE,
4957 char_type_node);
4963 NULL_TREE,
4964 empty_base_offsets);
4965 }
4968 }
4971 {
4972 /* Make sure that we are on a byte boundary so that the size of
4973 the class without virtual bases will always be a round number
4974 of bytes. */
4977 }
4979 /* Make sure that empty classes are reflected in RLI at this
4980 point. */
4983 /* Delete all zero-width bit-fields from the list of fields. Now
4984 that the type is laid out they are no longer important. */
4987 /* Create the version of T used for virtual bases. We do not use
4988 make_aggr_type for this version; this is an artificial type. For
4989 a POD type, we just reuse T. */
4991 {
4994 /* Set the size and alignment for the new type. In G++ 3.2, all
4995 empty classes were considered to have size zero when used as
4996 base classes. */
4998 {
5004 t);
5005 }
5006 else
5007 {
5010 }
5014 /* Copy the fields from T. */
5018 {
5027 }
5029 /* Record the base version of the type. */
5031 }
5032 else
5035 /* Every empty class contains an empty class. */
5039 /* Set the TYPE_DECL for this type to contain the right
5040 value for DECL_OFFSET, so that we can use it as part
5041 of a COMPONENT_REF for multiple inheritance. */
5044 /* Now fix up any virtual base class types that we left lying
5045 around. We must get these done before we try to lay out the
5046 virtual function table. As a side-effect, this will remove the
5047 base subobject fields. */
5050 /* Make sure that empty classes are reflected in RLI at this
5051 point. */
5054 /* Make sure not to create any structures with zero size. */
5059 /* Let the back-end lay out the type. */
5062 /* Warn about bases that can't be talked about due to ambiguity. */
5065 /* Clean up. */
5067 }
5069 /* Perform processing required when the definition of T (a class type)
5070 is complete. */
5072 void
5074 tree t;
5075 {
5076 tree x;
5077 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5080 tree vfield;
5083 {
5086 else
5090 }
5092 /* If this type was previously laid out as a forward reference,
5093 make sure we lay it out again. */
5100 /* Make assumptions about the class; we'll reset the flags if
5101 necessary. */
5106 /* Do end-of-class semantic processing: checking the validity of the
5107 bases and members and add implicitly generated methods. */
5110 /* Layout the class itself. */
5113 /* Make sure that we get our own copy of the vfield FIELD_DECL. */
5116 {
5122 /* The vtable better be at the start. */
5131 }
5132 else
5137 /* If we created a new vtbl pointer for this class, add it to the
5138 list. */
5143 /* If necessary, create the primary vtable for this class. */
5145 {
5146 /* We must enter these virtuals into the table. */
5150 /* Here we know enough to change the type of our virtual
5151 function table, but we will wait until later this function. */
5153 }
5156 {
5158 tree fn;
5167 /* Add entries for virtual functions introduced by this class. */
5170 /* Set DECL_VINDEX for all functions declared in this class. */
5172 fn;
5174 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5179 /* Add this class to the list of dynamic classes. */
5181 }
5185 /* Complete the rtl for any static member objects of the type we're
5186 working on. */
5192 /* Done with FIELDS...now decide whether to sort these for
5193 faster lookups later.
5195 The C front-end only does this when n_fields > 15. We use
5196 a smaller number because most searches fail (succeeding
5197 ultimately as the search bores through the inheritance
5198 hierarchy), and we want this failure to occur quickly. */
5202 {
5210 }
5213 {
5218 /* Mark the fact that constructor for T could affect anybody
5219 inheriting from T who wants to initialize vtables for
5220 VFIELDS's type. */
5223 }
5225 /* Make the rtl for any new vtables we have created, and unmark
5226 the base types we marked. */
5229 /* Build the VTT for T. */
5245 /* Finish debugging output for this type. */
5247 }
5249 /* When T was built up, the member declarations were added in reverse
5250 order. Rearrange them to declaration order. */
5252 void
5254 tree t;
5255 {
5256 tree next;
5257 tree prev;
5258 tree x;
5260 /* The following lists are all in reverse order. Put them in
5261 declaration order now. */
5266 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5267 reverse order, so we can't just use nreverse. */
5272 {
5276 }
5278 {
5282 }
5283 }
5285 tree
5288 {
5292 /* Now that we've got all the field declarations, reverse everything
5293 as necessary. */
5298 /* Nadger the current location so that diagnostics point to the start of
5299 the struct, not the end. */
5304 {
5307 }
5308 else
5318 else
5325 }
5326 \f
5327 /* Return the dynamic type of INSTANCE, if known.
5328 Used to determine whether the virtual function table is needed
5329 or not.
5331 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5332 of our knowledge of its type. *NONNULL should be initialized
5333 before this function is called. */
5335 static tree
5337 tree instance;
5340 {
5342 {
5346 else
5351 /* This is a call to a constructor, hence it's never zero. */
5353 {
5357 }
5361 /* This is a call to a constructor, hence it's never zero. */
5363 {
5367 }
5378 /* Propagate nonnull. */
5398 {
5402 }
5403 /* fall through... */
5408 {
5412 }
5414 {
5418 /* if we're in a ctor or dtor, we know our type. */
5422 {
5426 }
5427 }
5429 {
5430 /* Reference variables should be references to objects. */
5438 }
5443 }
5444 }
5446 /* Return nonzero if the dynamic type of INSTANCE is known, and
5447 equivalent to the static type. We also handle the case where
5448 INSTANCE is really a pointer. Return negative if this is a
5449 ctor/dtor. There the dynamic type is known, but this might not be
5450 the most derived base of the original object, and hence virtual
5451 bases may not be layed out according to this type.
5453 Used to determine whether the virtual function table is needed
5454 or not.
5456 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5457 of our knowledge of its type. *NONNULL should be initialized
5458 before this function is called. */
5460 int
5462 tree instance;
5464 {
5476 }
5478 \f
5479 void
5481 {
5484 current_class_stack
5501 }
5503 /* Set current scope to NAME. CODE tells us if this is a
5504 STRUCT, UNION, or ENUM environment.
5506 NAME may end up being NULL_TREE if this is an anonymous or
5507 late-bound struct (as in "struct { ... } foo;") */
5509 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE to
5510 appropriate values, found by looking up the type definition of
5511 NAME (as a CODE).
5513 If MODIFY is 1, we set IDENTIFIER_CLASS_VALUE's of names
5514 which can be seen locally to the class. They are shadowed by
5515 any subsequent local declaration (including parameter names).
5517 If MODIFY is 2, we set IDENTIFIER_CLASS_VALUE's of names
5518 which have static meaning (i.e., static members, static
5519 member functions, enum declarations, etc).
5521 If MODIFY is 3, we set IDENTIFIER_CLASS_VALUE of names
5522 which can be seen locally to the class (as in 1), but
5523 know that we are doing this for declaration purposes
5524 (i.e. friend foo::bar (int)).
5526 So that we may avoid calls to lookup_name, we cache the _TYPE
5527 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5529 For multiple inheritance, we perform a two-pass depth-first search
5530 of the type lattice. The first pass performs a pre-order search,
5531 marking types after the type has had its fields installed in
5532 the appropriate IDENTIFIER_CLASS_VALUE slot. The second pass merely
5533 unmarks the marked types. If a field or member function name
5534 appears in an ambiguous way, the IDENTIFIER_CLASS_VALUE of
5535 that name becomes `error_mark_node'. */
5537 void
5539 tree type;
5541 {
5544 /* Make sure there is enough room for the new entry on the stack. */
5546 {
5548 current_class_stack
5550 current_class_stack_size
5552 }
5554 /* Insert a new entry on the class stack. */
5559 current_class_depth++;
5561 /* Now set up the new type. */
5567 /* By default, things in classes are private, while things in
5568 structures or unions are public. */
5570 ? access_private_node
5577 {
5578 /* Forcibly remove any old class remnants. */
5580 }
5582 /* If we're about to enter a nested class, clear
5583 IDENTIFIER_CLASS_VALUE for the enclosing classes. */
5590 {
5593 else
5594 {
5595 tree item;
5597 /* We are re-entering the same class we just left, so we
5598 don't have to search the whole inheritance matrix to find
5599 all the decls to bind again. Instead, we install the
5600 cached class_shadowed list, and walk through it binding
5601 names and setting up IDENTIFIER_TYPE_VALUEs. */
5604 {
5611 }
5613 }
5616 }
5617 }
5619 /* When we exit a toplevel class scope, we save the
5620 IDENTIFIER_CLASS_VALUEs so that we can restore them quickly if we
5621 reenter the class. Here, we've entered some other class, so we
5622 must invalidate our cache. */
5624 void
5626 {
5627 tree t;
5629 /* The IDENTIFIER_CLASS_VALUEs are no longer valid. */
5635 }
5637 /* Get out of the current class scope. If we were in a class scope
5638 previously, that is the one popped to. */
5640 void
5642 {
5646 current_class_depth--;
5652 }
5654 /* Returns 1 if current_class_type is either T or a nested type of T.
5655 We start looking from 1 because entry 0 is from global scope, and has
5656 no type. */
5658 int
5660 tree t;
5661 {
5669 }
5671 /* If either current_class_type or one of its enclosing classes are derived
5672 from T, return the appropriate type. Used to determine how we found
5673 something via unqualified lookup. */
5675 tree
5677 tree t;
5678 {
5689 }
5691 /* When entering a class scope, all enclosing class scopes' names with
5692 static meaning (static variables, static functions, types and enumerators)
5693 have to be visible. This recursive function calls pushclass for all
5694 enclosing class contexts until global or a local scope is reached.
5695 TYPE is the enclosed class and MODIFY is equivalent with the pushclass
5696 formal of the same name. */
5698 void
5700 tree type;
5702 {
5703 tree context;
5705 /* A namespace might be passed in error cases, like A::B:C. */
5719 }
5721 /* Undoes a push_nested_class call. MODIFY is passed on to popclass. */
5723 void
5725 {
5731 }
5733 /* Returns the number of extern "LANG" blocks we are nested within. */
5735 int
5737 {
5739 }
5741 /* Set global variables CURRENT_LANG_NAME to appropriate value
5742 so that behavior of name-mangling machinery is correct. */
5744 void
5746 tree name;
5747 {
5751 {
5753 }
5755 {
5757 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5758 (See record_builtin_java_type in decl.c.) However, that causes
5759 incorrect debug entries if these types are actually used.
5760 So we re-enable debug output after extern "Java". */
5769 }
5771 {
5773 }
5774 else
5776 }
5778 /* Get out of the current language scope. */
5780 void
5782 {
5785 }
5786 \f
5787 /* Type instantiation routines. */
5789 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5790 matches the TARGET_TYPE. If there is no satisfactory match, return
5791 error_mark_node, and issue an error message if COMPLAIN is
5792 nonzero. Permit pointers to member function if PTRMEM is nonzero.
5793 If TEMPLATE_ONLY, the name of the overloaded function
5794 was a template-id, and EXPLICIT_TARGS are the explicitly provided
5795 template arguments. */
5797 static tree
5799 overload,
5800 complain,
5801 ptrmem,
5802 template_only,
5803 explicit_targs)
5804 tree target_type;
5805 tree overload;
5809 tree explicit_targs;
5810 {
5811 /* Here's what the standard says:
5813 [over.over]
5815 If the name is a function template, template argument deduction
5816 is done, and if the argument deduction succeeds, the deduced
5817 arguments are used to generate a single template function, which
5818 is added to the set of overloaded functions considered.
5820 Non-member functions and static member functions match targets of
5821 type "pointer-to-function" or "reference-to-function." Nonstatic
5822 member functions match targets of type "pointer-to-member
5823 function;" the function type of the pointer to member is used to
5824 select the member function from the set of overloaded member
5825 functions. If a nonstatic member function is selected, the
5826 reference to the overloaded function name is required to have the
5827 form of a pointer to member as described in 5.3.1.
5829 If more than one function is selected, any template functions in
5830 the set are eliminated if the set also contains a non-template
5831 function, and any given template function is eliminated if the
5832 set contains a second template function that is more specialized
5833 than the first according to the partial ordering rules 14.5.5.2.
5834 After such eliminations, if any, there shall remain exactly one
5835 selected function. */
5839 /* We store the matches in a TREE_LIST rooted here. The functions
5840 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5841 interoperability with most_specialized_instantiation. */
5843 tree fn;
5845 /* By the time we get here, we should be seeing only real
5846 pointer-to-member types, not the internal POINTER_TYPE to
5847 METHOD_TYPE representation. */
5855 /* Check that the TARGET_TYPE is reasonable. */
5859 /* This is OK, too. */
5862 {
5863 /* This is OK, too. This comes from a conversion to reference
5864 type. */
5867 }
5868 else
5869 {
5875 }
5877 /* If we can find a non-template function that matches, we can just
5878 use it. There's no point in generating template instantiations
5879 if we're just going to throw them out anyhow. But, of course, we
5880 can only do this when we don't *need* a template function. */
5882 {
5883 tree fns;
5886 {
5888 tree fntype;
5891 /* We're not looking for templates just yet. */
5896 /* We're looking for a non-static member, and this isn't
5897 one, or vice versa. */
5900 /* See if there's a match. */
5909 }
5910 }
5912 /* Now, if we've already got a match (or matches), there's no need
5913 to proceed to the template functions. But, if we don't have a
5914 match we need to look at them, too. */
5916 {
5917 tree target_fn_type;
5918 tree target_arg_types;
5919 tree target_ret_type;
5920 tree fns;
5923 target_fn_type
5925 else
5930 /* Never do unification on the 'this' parameter. */
5935 {
5937 tree instantiation;
5938 tree instantiation_type;
5939 tree targs;
5942 /* We're only looking for templates. */
5947 /* We're not looking for a non-static member, and this is
5948 one, or vice versa. */
5951 /* Try to do argument deduction. */
5956 /* Argument deduction failed. */
5959 /* Instantiate the template. */
5962 /* Instantiation failed. */
5965 /* See if there's a match. */
5968 instantiation_type =
5974 }
5976 /* Now, remove all but the most specialized of the matches. */
5978 {
5983 }
5984 }
5986 /* Now we should have exactly one function in MATCHES. */
5988 {
5989 /* There were *no* matches. */
5991 {
5994 target_type);
5996 /* print_candidates expects a chain with the functions in
5997 TREE_VALUE slots, so we cons one up here (we're losing anyway,
5998 so why be clever?). */
6001 matches);
6004 }
6006 }
6008 {
6009 /* There were too many matches. */
6012 {
6013 tree match;
6017 target_type);
6019 /* Since print_candidates expects the functions in the
6020 TREE_VALUE slot, we flip them here. */
6025 }
6028 }
6030 /* Good, exactly one match. Now, convert it to the correct type. */
6035 {
6043 {
6046 }
6047 }
6052 else
6053 {
6054 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
6055 will mark the function as addressed, but here we must do it
6056 explicitly. */
6060 }
6061 }
6063 /* This function will instantiate the type of the expression given in
6064 RHS to match the type of LHSTYPE. If errors exist, then return
6065 error_mark_node. FLAGS is a bit mask. If ITF_COMPLAIN is set, then
6066 we complain on errors. If we are not complaining, never modify rhs,
6067 as overload resolution wants to try many possible instantiations, in
6068 the hope that at least one will work.
6070 For non-recursive calls, LHSTYPE should be a function, pointer to
6071 function, or a pointer to member function. */
6073 tree
6076 tsubst_flags_t flags;
6077 {
6086 {
6090 }
6093 {
6100 }
6105 /* We don't overwrite rhs if it is an overloaded function.
6106 Copying it would destroy the tree link. */
6110 /* This should really only be used when attempting to distinguish
6111 what sort of a pointer to function we have. For now, any
6112 arithmetic operation which is not supported on pointers
6113 is rejected as an error. */
6116 {
6127 {
6128 tree new_rhs;
6138 }
6154 /* This can happen if we are forming a pointer-to-member for a
6155 member template. */
6158 /* Fall through. */
6161 {
6165 return
6167 fns,
6168 complain,
6169 allow_ptrmem,
6171 args);
6172 }
6175 return
6177 rhs,
6178 complain,
6179 allow_ptrmem,
6184 /* Now we should have a baselink. */
6190 /* This is too hard for now. */
6264 {
6268 }
6291 {
6296 }
6307 }
6308 }
6309 \f
6310 /* Return the name of the virtual function pointer field
6311 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6312 this may have to look back through base types to find the
6313 ultimate field name. (For single inheritance, these could
6314 all be the same name. Who knows for multiple inheritance). */
6316 static tree
6318 tree type;
6319 {
6334 }
6336 void
6338 {
6339 #ifdef GATHER_STATISTICS
6345 {
6350 }
6351 #endif
6352 }
6354 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6355 according to [class]:
6356 The class-name is also inserted
6357 into the scope of the class itself. For purposes of access checking,
6358 the inserted class name is treated as if it were a public member name. */
6360 void
6362 {
6365 tree saved_cas;
6378 }
6380 /* Returns 1 if TYPE contains only padding bytes. */
6382 int
6384 tree type;
6385 {
6392 /* In G++ 3.2, whether or not a class was empty was determined by
6393 looking at its size. */
6396 else
6398 }
6400 /* Returns true if TYPE contains an empty class. */
6402 static bool
6404 {
6408 {
6409 tree field;
6420 }
6424 }
6426 /* Find the enclosing class of the given NODE. NODE can be a *_DECL or
6427 a *_TYPE node. NODE can also be a local class. */
6429 tree
6431 tree type;
6432 {
6436 {
6438 {
6451 }
6452 }
6454 }
6456 /* Return 1 if TYPE or one of its enclosing classes is derived from BASE. */
6458 int
6461 {
6463 {
6468 }
6470 }
6472 /* Note that NAME was looked up while the current class was being
6473 defined and that the result of that lookup was DECL. */
6475 void
6477 tree name;
6478 tree decl;
6479 {
6480 splay_tree names_used;
6482 /* If we're not defining a class, there's nothing to do. */
6486 /* If there's already a binding for this NAME, then we don't have
6487 anything to worry about. */
6499 }
6501 /* Note that NAME was declared (as DECL) in the current class. Check
6502 to see that the declaration is valid. */
6504 void
6506 tree name;
6507 tree decl;
6508 {
6509 splay_tree names_used;
6510 splay_tree_node n;
6512 /* Look to see if we ever used this name. */
6513 names_used
6520 {
6521 /* [basic.scope.class]
6523 A name N used in a class S shall refer to the same declaration
6524 in its context and when re-evaluated in the completed scope of
6525 S. */
6530 }
6531 }
6533 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6534 Secondary vtables are merged with primary vtables; this function
6535 will return the VAR_DECL for the primary vtable. */
6537 tree
6539 tree binfo;
6540 {
6541 tree decl;
6545 {
6549 }
6553 }
6555 /* Called from get_primary_binfo via dfs_walk. DATA is a TREE_LIST
6556 who's TREE_PURPOSE is the TYPE of the required primary base and
6557 who's TREE_VALUE is a list of candidate binfos that we fill in. */
6559 static tree
6561 tree binfo;
6563 {
6569 /* This is the right type of binfo, but it might be an unshared
6570 instance, and the shared instance is later in the dfs walk. We
6571 must keep looking. */
6575 }
6577 /* Returns the unshared binfo for the primary base of BINFO. Note
6578 that in a complex hierarchy the resulting BINFO may not actually
6579 *be* primary. In particular if the resulting BINFO is a virtual
6580 base, and it occurs elsewhere in the hierarchy, then this
6581 occurrence may not actually be a primary base in the complete
6582 object. Check BINFO_PRIMARY_P to be sure. */
6584 tree
6586 tree binfo;
6587 {
6588 tree primary_base;
6590 tree virtuals;
6596 /* A non-virtual primary base is always a direct base, and easy to
6597 find. */
6599 {
6602 /* Scan the direct basetypes until we find a base with the same
6603 type as the primary base. */
6605 {
6611 }
6613 /* We should always find the primary base. */
6615 }
6617 /* For a primary virtual base, we have to scan the entire hierarchy
6618 rooted at BINFO; the virtual base could be an indirect virtual
6619 base. There could be more than one instance of the primary base
6620 in the hierarchy, and if one is the canonical binfo we want that
6621 one. If it exists, it should be the first one we find, but as a
6622 consistency check we find them all and make sure. */
6627 /* We must have found at least one instance. */
6631 {
6632 /* We found more than one instance of the base. We must make
6633 sure that, if one is the canonical one, it is the first one
6634 we found. As the chain is in reverse dfs order, that means
6635 the last on the list. */
6636 tree complete_binfo;
6637 tree canonical;
6647 {
6651 {
6652 /* This is the unshared instance. Make sure it was the
6653 first one found. */
6656 }
6657 }
6658 }
6659 else
6662 }
6664 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6666 static int
6671 {
6675 }
6677 /* Dump the offsets of all the bases rooted at BINFO (in the hierarchy
6678 dominated by T) to stderr. INDENT should be zero when called from
6679 the top level; it is incremented recursively. */
6681 static void
6685 tree t;
6686 tree binfo;
6688 {
6703 {
6709 else
6711 }
6716 {
6720 TFF_PLAIN_IDENTIFIER),
6722 }
6724 {
6727 }
6732 {
6736 {
6740 TFF_PLAIN_IDENTIFIER));
6741 }
6743 {
6747 TFF_PLAIN_IDENTIFIER));
6748 }
6750 {
6754 TFF_PLAIN_IDENTIFIER));
6755 }
6757 {
6761 TFF_PLAIN_IDENTIFIER));
6762 }
6766 }
6773 }
6775 /* Dump the BINFO hierarchy for T. */
6777 static void
6779 tree t;
6780 {
6794 }
6796 static void
6799 tree decl;
6800 {
6801 tree inits;
6803 HOST_WIDE_INT elt;
6811 TFF_PLAIN_IDENTIFIER));
6818 }
6820 static void
6822 tree t;
6823 tree binfo;
6824 tree vtable;
6825 {
6833 {
6840 {
6844 }
6848 }
6851 }
6853 static void
6855 tree t;
6856 tree vtt;
6857 {
6865 {
6870 }
6873 }
6875 /* Virtual function table initialization. */
6877 /* Create all the necessary vtables for T and its base classes. */
6879 static void
6881 tree t;
6882 {
6883 tree list;
6884 tree vbase;
6887 /* We lay out the primary and secondary vtables in one contiguous
6888 vtable. The primary vtable is first, followed by the non-virtual
6889 secondary vtables in inheritance graph order. */
6894 /* Then come the virtual bases, also in inheritance graph order. */
6896 {
6897 tree real_base;
6902 /* Although we walk in inheritance order, that might not get the
6903 canonical base. */
6908 }
6910 /* Fill in BINFO_VPTR_FIELD in the immediate binfos for our virtual
6911 base classes, for the benefit of the debugging backends. */
6913 {
6916 {
6919 }
6920 }
6924 }
6926 /* Initialize the vtable for BINFO with the INITS. */
6928 static void
6930 tree binfo;
6931 tree inits;
6932 {
6933 tree decl;
6939 }
6941 /* Initialize DECL (a declaration for a namespace-scope array) with
6942 the INITS. */
6944 static void
6946 tree decl;
6947 tree inits;
6948 {
6949 tree context;
6957 }
6959 /* Build the VTT (virtual table table) for T.
6960 A class requires a VTT if it has virtual bases.
6962 This holds
6963 1 - primary virtual pointer for complete object T
6964 2 - secondary VTTs for each direct non-virtual base of T which requires a
6965 VTT
6966 3 - secondary virtual pointers for each direct or indirect base of T which
6967 has virtual bases or is reachable via a virtual path from T.
6968 4 - secondary VTTs for each direct or indirect virtual base of T.
6970 Secondary VTTs look like complete object VTTs without part 4. */
6972 static void
6974 tree t;
6975 {
6976 tree inits;
6977 tree type;
6978 tree vtt;
6979 tree index;
6981 /* Build up the initializers for the VTT. */
6986 /* If we didn't need a VTT, we're done. */
6990 /* Figure out the type of the VTT. */
6994 /* Now, build the VTT object itself. */
6997 /* Add the VTT to the vtables list. */
7002 }
7004 /* The type corresponding to BASE_BINFO is a base of the type of BINFO, but
7005 from within some hierarchy which is inherited from the type of BINFO.
7006 Return BASE_BINFO's equivalent binfo from the hierarchy dominated by
7007 BINFO. */
7009 static tree
7011 tree base_binfo;
7012 tree binfo;
7013 {
7014 tree derived;
7029 }
7031 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7032 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7033 and CHAIN the vtable pointer for this binfo after construction is
7034 complete. VALUE can also be another BINFO, in which case we recurse. */
7036 static tree
7038 tree binfo;
7039 {
7040 tree vt;
7043 {
7049 else
7051 }
7054 }
7056 /* Recursively build the VTT-initializer for BINFO (which is in the
7057 hierarchy dominated by T). INITS points to the end of the initializer
7058 list to date. INDEX is the VTT index where the next element will be
7059 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7060 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7061 for virtual bases of T. When it is not so, we build the constructor
7062 vtables for the BINFO-in-T variant. */
7066 tree binfo;
7067 tree t;
7070 {
7072 tree b;
7073 tree init;
7074 tree secondary_vptrs;
7077 /* We only need VTTs for subobjects with virtual bases. */
7081 /* We need to use a construction vtable if this is not the primary
7082 VTT. */
7084 {
7087 /* Record the offset in the VTT where this sub-VTT can be found. */
7089 }
7091 /* Add the address of the primary vtable for the complete object. */
7096 {
7099 }
7102 /* Recursively add the secondary VTTs for non-virtual bases. */
7104 {
7109 }
7111 /* Add secondary virtual pointers for all subobjects of BINFO with
7112 either virtual bases or reachable along a virtual path, except
7113 subobjects that are non-virtual primary bases. */
7120 dfs_build_secondary_vptr_vtt_inits,
7121 NULL,
7122 dfs_ctor_vtable_bases_queue_p,
7123 secondary_vptrs);
7126 secondary_vptrs);
7130 /* The secondary vptrs come back in reverse order. After we reverse
7131 them, and add the INITS, the last init will be the first element
7132 of the chain. */
7135 {
7139 }
7141 /* Add the secondary VTTs for virtual bases. */
7144 {
7145 tree vbase;
7152 }
7155 {
7161 dfs_ctor_vtable_bases_queue_p,
7162 data);
7163 }
7166 }
7168 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo
7169 for the base in most derived. DATA is a TREE_LIST who's
7170 TREE_CHAIN is the type of the base being
7171 constructed whilst this secondary vptr is live. The TREE_UNSIGNED
7172 flag of DATA indicates that this is a constructor vtable. The
7173 TREE_TOP_LEVEL flag indicates that this is the primary VTT. */
7175 static tree
7177 tree binfo;
7179 {
7180 tree l;
7181 tree t;
7182 tree init;
7183 tree index;
7192 /* We don't care about bases that don't have vtables. */
7196 /* We're only interested in proper subobjects of T. */
7200 /* We're not interested in non-virtual primary bases. */
7204 /* If BINFO has virtual bases or is reachable via a virtual path
7205 from T, it'll have a secondary vptr. */
7210 /* Record the index where this secondary vptr can be found. */
7213 {
7216 }
7220 /* Add the initializer for the secondary vptr itself. */
7222 {
7223 /* It's a primary virtual base, and this is not the construction
7224 vtable. Find the base this is primary of in the inheritance graph,
7225 and use that base's vtable now. */
7228 }
7233 }
7235 /* dfs_walk_real predicate for building vtables. DATA is a TREE_LIST,
7236 VTT_MARKED_BINFO_P indicates whether marked or unmarked bases
7237 should be walked. TREE_PURPOSE is the TREE_TYPE that dominates the
7238 hierarchy. */
7240 static tree
7242 tree binfo;
7244 {
7246 /* Get the shared version. */
7252 }
7254 /* Called from build_vtt_inits via dfs_walk. After building constructor
7255 vtables and generating the sub-vtt from them, we need to restore the
7256 BINFO_VTABLES that were scribbled on. DATA is a TREE_LIST whose
7257 TREE_VALUE is the TREE_TYPE of the base whose sub vtt was generated. */
7259 static tree
7261 tree binfo;
7263 {
7266 /* We don't care about bases that don't have vtables. */
7270 /* If we scribbled the construction vtable vptr into BINFO, clear it
7271 out now. */
7279 }
7281 /* Build the construction vtable group for BINFO which is in the
7282 hierarchy dominated by T. */
7284 static void
7286 tree binfo;
7287 tree t;
7288 {
7289 tree list;
7290 tree type;
7291 tree vtbl;
7292 tree inits;
7293 tree id;
7294 tree vbase;
7296 /* See if we've already created this construction vtable group. */
7302 /* Build a version of VTBL (with the wrong type) for use in
7303 constructing the addresses of secondary vtables in the
7304 construction vtable group. */
7310 /* Add the vtables for each of our virtual bases using the vbase in T
7311 binfo. */
7313 vbase;
7315 {
7316 tree b;
7317 tree orig_base;
7325 }
7328 /* Figure out the type of the construction vtable. */
7333 /* Initialize the construction vtable. */
7337 }
7339 /* Add the vtbl initializers for BINFO (and its bases other than
7340 non-virtual primaries) to the list of INITS. BINFO is in the
7341 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7342 the constructor the vtbl inits should be accumulated for. (If this
7343 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7344 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7345 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7346 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7347 but are not necessarily the same in terms of layout. */
7349 static void
7351 tree binfo;
7352 tree orig_binfo;
7353 tree rtti_binfo;
7354 tree t;
7355 tree inits;
7356 {
7364 /* If it doesn't have a vptr, we don't do anything. */
7368 /* If we're building a construction vtable, we're not interested in
7369 subobjects that don't require construction vtables. */
7375 /* Build the initializers for the BINFO-in-T vtable. */
7381 /* Walk the BINFO and its bases. We walk in preorder so that as we
7382 initialize each vtable we can figure out at what offset the
7383 secondary vtable lies from the primary vtable. We can't use
7384 dfs_walk here because we need to iterate through bases of BINFO
7385 and RTTI_BINFO simultaneously. */
7387 {
7390 /* Skip virtual bases. */
7396 inits);
7397 }
7398 }
7400 /* Called from accumulate_vtbl_inits. Returns the initializers for
7401 the BINFO vtable. */
7403 static tree
7405 tree binfo;
7406 tree orig_binfo;
7407 tree rtti_binfo;
7408 tree t;
7409 tree l;
7410 {
7417 {
7418 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7419 primary virtual base. If it is not the same primary in
7420 the hierarchy of T, we'll need to generate a ctor vtable
7421 for it, to place at its location in T. If it is the same
7422 primary, we still need a VTT entry for the vtable, but it
7423 should point to the ctor vtable for the base it is a
7424 primary for within the sub-hierarchy of RTTI_BINFO.
7426 There are three possible cases:
7428 1) We are in the same place.
7429 2) We are a primary base within a lost primary virtual base of
7430 RTTI_BINFO.
7431 3) We are primary to something not a base of RTTI_BINFO. */
7436 /* First, look through the bases we are primary to for RTTI_BINFO
7437 or a virtual base. */
7439 {
7443 }
7444 /* If we run out of primary links, keep looking down our
7445 inheritance chain; we might be an indirect primary. */
7451 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7452 base B and it is a base of RTTI_BINFO, this is case 2. In
7453 either case, we share our vtable with LAST, i.e. the
7454 derived-most base within B of which we are a primary. */
7458 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7459 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7460 binfo_ctor_vtable after everything's been set up. */
7463 /* Otherwise, this is case 3 and we get our own. */
7464 }
7469 {
7470 tree index;
7473 /* Compute the initializer for this vtable. */
7477 /* Figure out the position to which the VPTR should point. */
7480 vtbl_ptr_type_node,
7481 vtbl);
7488 index);
7491 }
7494 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7495 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7496 straighten this out. */
7500 else
7501 /* For an ordinary vtable, set BINFO_VTABLE. */
7505 }
7507 /* Construct the initializer for BINFO's virtual function table. BINFO
7508 is part of the hierarchy dominated by T. If we're building a
7509 construction vtable, the ORIG_BINFO is the binfo we should use to
7510 find the actual function pointers to put in the vtable - but they
7511 can be overridden on the path to most-derived in the graph that
7512 ORIG_BINFO belongs. Otherwise,
7513 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7514 BINFO that should be indicated by the RTTI information in the
7515 vtable; it will be a base class of T, rather than T itself, if we
7516 are building a construction vtable.
7518 The value returned is a TREE_LIST suitable for wrapping in a
7519 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7520 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7521 number of non-function entries in the vtable.
7523 It might seem that this function should never be called with a
7524 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7525 base is always subsumed by a derived class vtable. However, when
7526 we are building construction vtables, we do build vtables for
7527 primary bases; we need these while the primary base is being
7528 constructed. */
7530 static tree
7532 tree binfo;
7533 tree orig_binfo;
7534 tree t;
7535 tree rtti_binfo;
7537 {
7539 tree vfun_inits;
7540 tree vbase;
7541 vtbl_init_data vid;
7543 /* Initialize VID. */
7552 /* The first vbase or vcall offset is at index -3 in the vtable. */
7555 /* Add entries to the vtable for RTTI. */
7558 /* Create an array for keeping track of the functions we've
7559 processed. When we see multiple functions with the same
7560 signature, we share the vcall offsets. */
7562 /* Add the vcall and vbase offset entries. */
7564 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7565 build_vbase_offset_vtbl_entries. */
7567 vbase;
7571 /* If the target requires padding between data entries, add that now. */
7573 {
7577 {
7584 null_pointer_node),
7585 add);
7587 }
7588 }
7593 /* Go through all the ordinary virtual functions, building up
7594 initializers. */
7597 {
7598 tree delta;
7599 tree vcall_index;
7600 tree fn;
7605 /* If the only definition of this function signature along our
7606 primary base chain is from a lost primary, this vtable slot will
7607 never be used, so just zero it out. This is important to avoid
7608 requiring extra thunks which cannot be generated with the function.
7610 We first check this in update_vtable_entry_for_fn, so we handle
7611 restored primary bases properly; we also need to do it here so we
7612 zero out unused slots in ctor vtables, rather than filling themff
7613 with erroneous values (though harmless, apart from relocation
7614 costs). */
7616 {
7617 /* We found a defn before a lost primary; go ahead as normal. */
7621 /* The nearest definition is from a lost primary; clear the
7622 slot. */
7624 {
7627 }
7628 }
7631 {
7632 /* Pull the offset for `this', and the function to call, out of
7633 the list. */
7640 /* You can't call an abstract virtual function; it's abstract.
7641 So, we replace these functions with __pure_virtual. */
7646 /* Take the address of the function, considering it to be of an
7647 appropriate generic type. */
7649 /* The address of a function can't change. */
7651 }
7653 /* And add it to the chain of initializers. */
7655 {
7660 else
7662 {
7669 }
7670 }
7671 else
7673 }
7675 /* The initializers for virtual functions were built up in reverse
7676 order; straighten them out now. */
7679 /* The negative offset initializers are also in reverse order. */
7682 /* Chain the two together. */
7684 }
7686 /* Adds to vid->inits the initializers for the vbase and vcall
7687 offsets in BINFO, which is in the hierarchy dominated by T. */
7689 static void
7691 tree binfo;
7693 {
7694 tree b;
7696 /* If this is a derived class, we must first create entries
7697 corresponding to the primary base class. */
7702 /* Add the vbase entries for this base. */
7704 /* Add the vcall entries for this base. */
7706 }
7708 /* Returns the initializers for the vbase offset entries in the vtable
7709 for BINFO (which is part of the class hierarchy dominated by T), in
7710 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7711 where the next vbase offset will go. */
7713 static void
7715 tree binfo;
7717 {
7718 tree vbase;
7719 tree t;
7720 tree non_primary_binfo;
7722 /* If there are no virtual baseclasses, then there is nothing to
7723 do. */
7729 /* We might be a primary base class. Go up the inheritance hierarchy
7730 until we find the most derived class of which we are a primary base:
7731 it is the offset of that which we need to use. */
7734 {
7735 tree b;
7737 /* If we have reached a virtual base, then it must be a primary
7738 base (possibly multi-level) of vid->binfo, or we wouldn't
7739 have called build_vcall_and_vbase_vtbl_entries for it. But it
7740 might be a lost primary, so just skip down to vid->binfo. */
7742 {
7745 }
7751 }
7753 /* Go through the virtual bases, adding the offsets. */
7755 vbase;
7757 {
7758 tree b;
7759 tree delta;
7764 /* Find the instance of this virtual base in the complete
7765 object. */
7768 /* If we've already got an offset for this virtual base, we
7769 don't need another one. */
7774 /* Figure out where we can find this vbase offset. */
7783 {
7784 tree orig_vbase;
7786 /* Find the instance of this virtual base in the type of BINFO. */
7790 /* The vbase offset had better be the same. */
7794 }
7796 /* The next vbase will come at a more negative offset. */
7800 /* The initializer is the delta from BINFO to this virtual base.
7801 The vbase offsets go in reverse inheritance-graph order, and
7802 we are walking in inheritance graph order so these end up in
7803 the right order. */
7809 vtable_entry_type,
7810 delta)));
7812 }
7813 }
7815 /* Adds the initializers for the vcall offset entries in the vtable
7816 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7817 to VID->INITS. */
7819 static void
7821 tree binfo;
7823 {
7824 /* We only need these entries if this base is a virtual base. We
7825 compute the indices -- but do not add to the vtable -- when
7826 building the main vtable for a class. */
7828 {
7829 /* We need a vcall offset for each of the virtual functions in this
7830 vtable. For example:
7832 class A { virtual void f (); };
7833 class B1 : virtual public A { virtual void f (); };
7834 class B2 : virtual public A { virtual void f (); };
7835 class C: public B1, public B2 { virtual void f (); };
7837 A C object has a primary base of B1, which has a primary base of A. A
7838 C also has a secondary base of B2, which no longer has a primary base
7839 of A. So the B2-in-C construction vtable needs a secondary vtable for
7840 A, which will adjust the A* to a B2* to call f. We have no way of
7841 knowing what (or even whether) this offset will be when we define B2,
7842 so we store this "vcall offset" in the A sub-vtable and look it up in
7843 a "virtual thunk" for B2::f.
7845 We need entries for all the functions in our primary vtable and
7846 in our non-virtual bases' secondary vtables. */
7848 /* If we are just computing the vcall indices -- but do not need
7849 the actual entries -- not that. */
7852 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7854 }
7855 }
7857 /* Build vcall offsets, starting with those for BINFO. */
7859 static void
7861 tree binfo;
7863 {
7865 tree primary_binfo;
7867 /* Don't walk into virtual bases -- except, of course, for the
7868 virtual base for which we are building vcall offsets. Any
7869 primary virtual base will have already had its offsets generated
7870 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7874 /* If BINFO has a primary base, process it first. */
7879 /* Add BINFO itself to the list. */
7882 /* Scan the non-primary bases of BINFO. */
7884 {
7885 tree base_binfo;
7890 }
7891 }
7893 /* Called from build_vcall_offset_vtbl_entries_r. */
7895 static void
7897 tree binfo;
7899 {
7900 tree derived_virtuals;
7901 tree base_virtuals;
7902 tree orig_virtuals;
7903 tree binfo_inits;
7904 /* If BINFO is a primary base, the most derived class which has BINFO as
7905 a primary base; otherwise, just BINFO. */
7906 tree non_primary_binfo;
7910 /* We might be a primary base class. Go up the inheritance hierarchy
7911 until we find the most derived class of which we are a primary base:
7912 it is the BINFO_VIRTUALS there that we need to consider. */
7915 {
7916 tree b;
7918 /* If we have reached a virtual base, then it must be vid->vbase,
7919 because we ignore other virtual bases in
7920 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7921 base (possibly multi-level) of vid->binfo, or we wouldn't
7922 have called build_vcall_and_vbase_vtbl_entries for it. But it
7923 might be a lost primary, so just skip down to vid->binfo. */
7925 {
7930 }
7936 }
7939 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7940 where rtti_binfo is the most derived type. */
7941 non_primary_binfo = get_original_base
7944 /* Make entries for the rest of the virtuals. */
7948 base_virtuals;
7952 {
7953 tree orig_fn;
7954 tree fn;
7956 tree vcall_offset;
7958 /* Find the declaration that originally caused this function to
7959 be present in BINFO_TYPE (binfo). */
7962 /* When processing BINFO, we only want to generate vcall slots for
7963 function slots introduced in BINFO. So don't try to generate
7964 one if the function isn't even defined in BINFO. */
7968 /* Find the overriding function. */
7971 /* If there is already an entry for a function with the same
7972 signature as FN, then we do not need a second vcall offset.
7973 Check the list of functions already present in the derived
7974 class vtable. */
7976 {
7977 tree derived_entry;
7981 /* We only use one vcall offset for virtual destructors,
7982 even though there are two virtual table entries. */
7986 }
7990 /* If we are building these vcall offsets as part of building
7991 the vtable for the most derived class, remember the vcall
7992 offset. */
7997 /* The next vcall offset will be found at a more negative
7998 offset. */
8002 /* Keep track of this function. */
8006 {
8007 tree base;
8008 tree base_binfo;
8010 /* The FN comes from BASE. So, we must calculate the
8011 adjustment from vid->vbase to BASE. We can just look for
8012 BASE in the complete object because we are converting
8013 from a virtual base, so if there were multiple copies,
8014 there would not be a unique final overrider and
8015 vid->derived would be ill-formed. */
8019 /* Compute the vcall offset. */
8020 /* As mentioned above, the vbase we're working on is a
8021 primary base of vid->binfo. But it might be a lost
8022 primary, so its BINFO_OFFSET might be wrong, so we just
8023 use the BINFO_OFFSET from vid->binfo. */
8026 vcall_offset);
8028 vcall_offset));
8032 }
8033 }
8034 }
8036 /* Return vtbl initializers for the RTTI entries coresponding to the
8037 BINFO's vtable. The RTTI entries should indicate the object given
8038 by VID->rtti_binfo. */
8040 static void
8042 tree binfo;
8044 {
8045 tree b;
8046 tree t;
8047 tree basetype;
8048 tree offset;
8049 tree decl;
8050 tree init;
8055 /* To find the complete object, we will first convert to our most
8056 primary base, and then add the offset in the vtbl to that value. */
8060 {
8061 tree primary_base;
8066 }
8069 /* The second entry is the address of the typeinfo object. */
8072 else
8075 /* Convert the declaration to a type that can be stored in the
8076 vtable. */
8082 /* Add the offset-to-top entry. It comes earlier in the vtable that
8083 the the typeinfo entry. Convert the offset to look like a
8084 function pointer, so that we can put it in the vtable. */
8089 }