| blob | 48dadea487c4fdd736a5bbdd8e30a28d283613d7 |
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. */
92 /* The type of a function passed to walk_subobject_offsets. */
95 /* The stack itself. This is an dynamically resized array. The
96 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
100 /* An array of all local classes present in this translation unit, in
101 declaration order. */
102 varray_type local_classes;
180 tree));
184 vtbl_init_data *));
210 splay_tree_key k2));
214 /* Macros for dfs walking during vtt construction. See
215 dfs_ctor_vtable_bases_queue_p, dfs_build_secondary_vptr_vtt_inits
216 and dfs_fixup_binfo_vtbls. */
217 #define VTT_TOP_LEVEL_P(NODE) TREE_UNSIGNED (NODE)
218 #define VTT_MARKED_BINFO_P(NODE) TREE_USED (NODE)
220 /* Variables shared between class.c and call.c. */
222 #ifdef GATHER_STATISTICS
231 #endif
233 /* Convert to or from a base subobject. EXPR is an expression of type
234 `A' or `A*', an expression of type `B' or `B*' is returned. To
235 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
236 the B base instance within A. To convert base A to derived B, CODE
237 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
238 In this latter case, A must not be a morally virtual base of B.
239 NONNULL is true if EXPR is known to be non-NULL (this is only
240 needed when EXPR is of pointer type). CV qualifiers are preserved
241 from EXPR. */
243 tree
246 tree expr;
247 tree binfo;
249 {
252 tree probe;
253 tree offset;
254 tree target_type;
256 tree ptr_target_type;
264 {
268 }
281 {
285 }
299 {
300 /* Going via virtual base V_BINFO. We need the static offset
301 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
302 V_BINFO. That offset is an entry in D_BINFO's vtable. */
312 v_offset);
323 /* Negative fixed_type_p means this is a constructor or destructor;
324 virtual base layout is fixed in in-charge [cd]tors, but not in
325 base [cd]tors. */
329 v_offset,
331 else
333 }
337 target_type = cp_build_qualified_type
347 else
356 expr);
359 }
361 /* Convert OBJECT to the base TYPE. If CHECK_ACCESS is true, an error
362 message is emitted if TYPE is inaccessible. OBJECT is assumed to
363 be non-NULL. */
365 tree
367 {
368 tree binfo;
372 NULL);
377 }
379 \f
380 /* Virtual function things. */
382 static tree
385 {
407 }
409 /* Given an object INSTANCE, return an expression which yields the
410 vtable element corresponding to INDEX. There are many special
411 cases for INSTANCE which we take care of here, mainly to avoid
412 creating extra tree nodes when we don't have to. */
414 static tree
417 {
418 tree aref;
421 /* Try to figure out what a reference refers to, and
422 access its virtual function table directly. */
432 {
437 }
440 {
442 }
450 }
452 tree
455 {
462 }
464 /* Given an object INSTANCE, return an expression which yields a
465 function pointer corresponding to vtable element INDEX. */
467 tree
470 {
473 /* When using function descriptors, the address of the
474 vtable entry is treated as a function pointer. */
483 }
485 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
486 for the given TYPE. */
488 static tree
490 tree type;
491 {
493 }
495 /* Return an IDENTIFIER_NODE for the name of the virtual table table
496 for TYPE. */
498 tree
500 tree type;
501 {
503 }
505 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
506 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
507 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
509 static tree
511 tree class_type;
512 tree name;
513 tree vtable_type;
514 {
515 tree decl;
518 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
519 now to avoid confusion in mangle_decl. */
531 }
533 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
534 or even complete. If this does not exist, create it. If COMPLETE is
535 non-zero, then complete the definition of it -- that will render it
536 impossible to actually build the vtable, but is useful to get at those
537 which are known to exist in the runtime. */
539 tree
541 tree type;
543 {
548 {
552 }
559 /* At one time the vtable info was grabbed 2 words at a time. This
560 fails on sparc unless you have 8-byte alignment. (tiemann) */
565 {
568 }
571 }
573 /* Returns a copy of the BINFO_VIRTUALS list in BINFO. The
574 BV_VCALL_INDEX for each entry is cleared. */
576 static tree
578 tree binfo;
579 {
580 tree copies;
581 tree t;
585 {
588 }
591 }
593 /* Build the primary virtual function table for TYPE. If BINFO is
594 non-NULL, build the vtable starting with the initial approximation
595 that it is the same as the one which is the head of the association
596 list. Returns a non-zero value if a new vtable is actually
597 created. */
599 static int
602 {
603 tree decl;
604 tree virtuals;
609 {
611 /* We have already created a vtable for this base, so there's
612 no need to do it again. */
619 }
620 else
621 {
625 }
627 #ifdef GATHER_STATISTICS
630 #endif
632 /* Initialize the association list for this type, based
633 on our first approximation. */
638 }
640 /* Give BINFO a new virtual function table which is initialized
641 with a skeleton-copy of its original initialization. The only
642 entry that changes is the `delta' entry, so we can really
643 share a lot of structure.
645 FOR_TYPE is the most derived type which caused this table to
646 be needed.
648 Returns non-zero if we haven't met BINFO before.
650 The order in which vtables are built (by calling this function) for
651 an object must remain the same, otherwise a binary incompatibility
652 can result. */
654 static int
657 {
661 /* We already created a vtable for this base. There's no need to
662 do it again. */
665 /* Remember that we've created a vtable for this BINFO, so that we
666 don't try to do so again. */
669 /* Make fresh virtual list, so we can smash it later. */
672 /* Secondary vtables are laid out as part of the same structure as
673 the primary vtable. */
676 }
678 /* Create a new vtable for BINFO which is the hierarchy dominated by
679 T. Return non-zero if we actually created a new vtable. */
681 static int
683 tree t;
684 tree binfo;
685 {
687 /* In this case, it is *type*'s vtable we are modifying. We start
688 with the approximation that its vtable is that of the
689 immediate base class. */
690 /* ??? This actually passes TYPE_BINFO (t), not the primary base binfo,
691 since we've updated DECL_CONTEXT (TYPE_VFIELD (t)) by now. */
693 t);
694 else
695 /* This is our very own copy of `basetype' to play with. Later,
696 we will fill in all the virtual functions that override the
697 virtual functions in these base classes which are not defined
698 by the current type. */
700 }
702 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
703 (which is in the hierarchy dominated by T) list FNDECL as its
704 BV_FN. DELTA is the required constant adjustment from the `this'
705 pointer where the vtable entry appears to the `this' required when
706 the function is actually called. */
708 static void
710 tree t;
711 tree binfo;
712 tree fndecl;
713 tree delta;
715 {
716 tree v;
722 {
723 tree base_fndecl;
725 /* We need a new vtable for BINFO. */
727 {
728 /* If we really did make a new vtable, we also made a copy
729 of the BINFO_VIRTUALS list. Now, we have to find the
730 corresponding entry in that list. */
735 }
742 /* Now assign virtual dispatch information, if unset. We can
743 dispatch this through any overridden base function.
745 FIXME this can choose a secondary vtable if the primary is not
746 also lexically first, leading to useless conversions.
747 In the V3 ABI, there's no reason for DECL_VIRTUAL_CONTEXT to
748 ever be different from DECL_CONTEXT. */
750 {
753 }
754 }
755 }
757 /* Set DECL_VINDEX for DECL. VINDEX_P is the number of virtual
758 functions present in the vtable so far. */
760 static void
762 tree decl;
764 {
771 }
772 \f
773 /* Add method METHOD to class TYPE. If ERROR_P is true, we are adding
774 the method after the class has already been defined because a
775 declaration for it was seen. (Even though that is erroneous, we
776 add the method for improved error recovery.) */
778 void
780 tree type;
781 tree method;
783 {
787 tree method_vec;
792 /* Make a new method vector. We start with 8 entries. We must
793 allocate at least two (for constructors and destructors), and
794 we're going to end up with an assignment operator at some point
795 as well.
797 We could use a TREE_LIST for now, and convert it to a TREE_VEC
798 in finish_struct, but we would probably waste more memory
799 making the links in the list than we would by over-allocating
800 the size of the vector here. Furthermore, we would complicate
801 all the code that expects this to be a vector. */
807 /* Constructors and destructors go in special slots. */
812 else
813 {
816 /* See if we already have an entry with this name. */
818 {
826 {
830 /* If we need to move things up, see if there's
831 space. */
833 {
836 slot++;
837 }
839 }
842 }
845 {
846 /* We need a bigger method vector. */
848 tree new_vec;
850 /* In the non-error case, we are processing a class
851 definition. Double the size of the vector to give room
852 for new methods. */
855 /* In the error case, the vector is already complete. We
856 don't expect many errors, and the rest of the front-end
857 will get confused if there are empty slots in the vector. */
858 else
866 }
869 {
870 /* Type conversion operators have to come before ordinary
871 methods; add_conversions depends on this to speed up
872 looking for conversion operators. So, if necessary, we
873 slide some of the vector elements up. In theory, this
874 makes this algorithm O(N^2) but we don't expect many
875 conversion operators. */
878 else
880 {
884 /* There are no more entries in the vector, so we
885 can insert the new conversion operator here. */
889 /* We can insert the new function right at the
890 SLOTth position. */
892 }
897 /* There is nothing in the Ith slot, so we can avoid
898 moving anything. */
899 ;
900 else
901 {
902 /* We know the last slot in the vector is empty
903 because we know that at this point there's room
904 for a new function. */
909 }
910 }
911 }
914 /* TYPE is a template class. Don't issue any errors now; wait
915 until instantiation time to complain. */
916 ;
917 else
918 {
919 tree fns;
921 /* Check to see if we've already got this method. */
923 fns;
925 {
927 tree parms1;
928 tree parms2;
934 /* [over.load] Member function declarations with the
935 same name and the same parameter types cannot be
936 overloaded if any of them is a static member
937 function declaration.
939 [namespace.udecl] When a using-declaration brings names
940 from a base class into a derived class scope, member
941 functions in the derived class override and/or hide member
942 functions with the same name and parameter types in a base
943 class (rather than conflicting). */
947 /* Compare the quals on the 'this' parm. Don't compare
948 the whole types, as used functions are treated as
949 coming from the using class in overload resolution. */
964 {
966 /* Defer to the local function. */
968 else
969 {
973 /* We don't call duplicate_decls here to merge
974 the declarations because that will confuse
975 things if the methods have inline
976 definitions. In particular, we will crash
977 while processing the definitions. */
979 }
980 }
981 }
982 }
984 /* Actually insert the new method. */
988 /* Add the new binding. */
993 }
995 /* Subroutines of finish_struct. */
997 /* Look through the list of fields for this struct, deleting
998 duplicates as we go. This must be recursive to handle
999 anonymous unions.
1001 FIELD is the field which may not appear anywhere in FIELDS.
1002 FIELD_PTR, if non-null, is the starting point at which
1003 chained deletions may take place.
1004 The value returned is the first acceptable entry found
1005 in FIELDS.
1007 Note that anonymous fields which are not of UNION_TYPE are
1008 not duplicates, they are just anonymous fields. This happens
1009 when we have unnamed bitfields, for example. */
1011 static tree
1014 {
1015 tree x;
1018 {
1025 }
1026 else
1027 {
1029 {
1031 {
1037 {
1040 else
1042 }
1043 }
1045 /* A using declaration is allowed to appear more than
1046 once. We'll prune these from the field list later, and
1047 handle_using_decl will complain about invalid multiple
1048 uses. */
1049 ;
1051 {
1058 x);
1061 {
1065 }
1068 {
1069 /* Hide tag decls. */
1076 x);
1077 }
1078 else
1082 else
1084 }
1085 }
1086 }
1088 }
1090 static void
1092 tree fields;
1093 {
1094 tree x;
1097 }
1099 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1100 legit, otherwise return 0. */
1102 static int
1104 tree t;
1105 tree fdecl;
1106 tree access;
1107 {
1108 tree elem;
1118 {
1120 {
1123 else
1126 }
1127 else
1128 {
1129 /* They're changing the access to the same thing they changed
1130 it to before. That's OK. */
1131 ;
1132 }
1133 }
1134 else
1135 {
1139 }
1141 }
1143 /* Process the USING_DECL, which is a member of T. */
1145 static void
1147 tree using_decl;
1148 tree t;
1149 {
1152 tree access
1158 tree old_value;
1165 {
1168 }
1170 {
1173 }
1178 {
1181 }
1184 /* Ignore base type this came from. */
1189 {
1195 else
1197 }
1203 ;
1205 {
1207 /* It's OK to use functions from a base when there are functions with
1209 else
1210 {
1215 }
1216 }
1218 {
1222 }
1224 /* Make type T see field decl FDECL with access ACCESS.*/
1227 {
1230 }
1231 else
1233 }
1234 \f
1235 /* Run through the base clases of T, updating
1236 CANT_HAVE_DEFAULT_CTOR_P, CANT_HAVE_CONST_CTOR_P, and
1237 NO_CONST_ASN_REF_P. Also set flag bits in T based on properties of
1238 the bases. */
1240 static void
1242 no_const_asn_ref_p)
1243 tree t;
1247 {
1251 tree binfos;
1257 /* An aggregate cannot have baseclasses. */
1261 {
1262 tree base_binfo;
1263 tree basetype;
1265 /* Figure out what base we're looking at. */
1269 /* If the type of basetype is incomplete, then we already
1270 complained about that fact (and we should have fixed it up as
1271 well). */
1273 {
1275 /* The base type is of incomplete type. It is
1276 probably best to pretend that it does not
1277 exist. */
1285 }
1287 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1288 here because the case of virtual functions but non-virtual
1289 dtor is handled in finish_struct_1. */
1293 basetype);
1295 /* If the base class doesn't have copy constructors or
1296 assignment operators that take const references, then the
1297 derived class cannot have such a member automatically
1298 generated. */
1304 /* Similarly, if the base class doesn't have a default
1305 constructor, then the derived class won't have an
1306 automatically generated default constructor. */
1309 {
1313 basetype);
1314 }
1317 /* A virtual base does not effect nearly emptiness. */
1318 ;
1320 {
1322 /* And if there is more than one nearly empty base, then the
1323 derived class is not nearly empty either. */
1325 else
1326 /* Remember we've seen one. */
1328 }
1330 /* If the base class is not empty or nearly empty, then this
1331 class cannot be nearly empty. */
1334 /* A lot of properties from the bases also apply to the derived
1335 class. */
1346 }
1347 }
1349 /* Binfo FROM is within a virtual hierarchy which is being reseated to
1350 TO. Move primary information from FROM to TO, and recursively traverse
1351 into FROM's bases. The hierarchy is dominated by TYPE. MAPPINGS is an
1352 assoc list of binfos that have already been reseated. */
1354 static void
1356 tree to;
1357 tree from;
1358 tree type;
1359 tree mappings;
1360 {
1372 {
1374 tree assoc;
1376 /* We might have just moved the primary base too, see if it's on our
1377 mappings. */
1383 }
1390 {
1396 }
1399 {
1404 {
1407 /* This base is a primary of some binfo we have already
1408 reseated. We must reseat this one too. */
1410 }
1411 else
1413 }
1414 }
1416 /* FROM is the canonical binfo for a virtual base. It is being reseated to
1417 make TO the canonical binfo, within the hierarchy dominated by TYPE.
1418 MAPPINGS is an assoc list of binfos that have already been reseated.
1419 Adjust any non-virtual bases within FROM, and also move any virtual bases
1420 which are canonical. This complication arises because selecting primary
1421 bases walks in inheritance graph order, but we don't share binfos for
1422 virtual bases, hence we can fill in the primaries for a virtual base,
1423 and then discover that a later base requires the virtual as its
1424 primary. */
1426 static void
1428 tree to;
1429 tree from;
1430 tree type;
1431 tree mappings;
1432 {
1436 {
1439 }
1440 }
1442 /* Make BASE_BINFO the a primary virtual base within the hierarchy
1443 dominated by TYPE. Returns BASE_BINFO, if it is not already one, NULL
1444 otherwise (because something else has already made it primary). */
1446 static tree
1448 tree base_binfo;
1449 tree type;
1450 {
1454 {
1455 /* It's already allocated in the hierarchy. BINFO won't have a
1456 primary base in this hierarchy, even though the complete object
1457 BINFO is for, would do. */
1459 }
1461 /* We need to make sure that the assoc list
1462 CLASSTYPE_VBASECLASSES of TYPE, indicates this particular
1463 primary BINFO for the virtual base, as this is the one
1464 that'll really exist. */
1469 }
1471 /* If BINFO is an unmarked virtual binfo for a class with a primary virtual
1472 base, then BINFO has no primary base in this graph. Called from
1473 mark_primary_bases. DATA is the most derived type. */
1476 tree binfo;
1478 {
1483 {
1484 /* This morally virtual base has a primary base when it
1485 is a complete object. We need to locate the shared instance
1486 of this binfo in the type dominated by T. We duplicate the
1487 primary base information from there to here. */
1488 tree vbase;
1489 tree unshared_base;
1496 t));
1501 }
1504 /* The vtable fields will have been copied when duplicating the
1505 base binfos. That information is bogus, make sure we don't try
1506 and use it. */
1509 /* If this is a virtual primary base, make sure its offset matches
1510 that which it is primary for. */
1513 {
1518 }
1522 }
1524 /* Set BINFO_PRIMARY_BASE_OF for all binfos in the hierarchy
1525 dominated by TYPE that are primary bases. */
1527 static void
1529 tree type;
1530 {
1531 tree binfo;
1533 /* Walk the bases in inheritance graph order. */
1535 {
1536 tree base_binfo;
1539 /* Not a dynamic base. */
1549 else
1553 }
1554 /* There could remain unshared morally virtual bases which were not
1555 visited in the inheritance graph walk. These bases will have lost
1556 their virtual primary base (should they have one). We must now
1557 find them. Also we must fix up the BINFO_OFFSETs of primary
1558 virtual bases. We could not do that as we went along, as they
1559 were originally copied from the bases we inherited from by
1560 unshare_base_binfos. That may have decided differently about
1561 where a virtual primary base went. */
1563 }
1565 /* Make the BINFO the primary base of T. */
1567 static void
1569 tree t;
1570 tree binfo;
1572 {
1573 tree basetype;
1582 }
1584 /* Determine the primary class for T. */
1586 static void
1588 tree t;
1590 {
1592 tree vbases;
1593 tree type_binfo;
1595 /* If there are no baseclasses, there is certainly no primary base. */
1602 {
1607 {
1608 /* Even a virtual baseclass can contain our RTTI
1609 information. But, we prefer a non-virtual polymorphic
1610 baseclass. */
1614 /* We prefer a non-virtual base, although a virtual one will
1615 do. */
1620 {
1623 }
1624 else
1625 {
1626 tree vfields;
1628 /* Only add unique vfields, and flatten them out as we go. */
1630 vfields;
1638 }
1639 }
1640 }
1645 /* Find the indirect primary bases - those virtual bases which are primary
1646 bases of something else in this hierarchy. */
1648 vbases;
1650 {
1653 /* See if this virtual base is an indirect primary base. To be so,
1654 it must be a primary base within the hierarchy of one of our
1655 direct bases. */
1657 {
1659 tree v;
1662 v;
1664 {
1670 {
1673 }
1674 }
1676 /* If we've discovered that this virtual base is an indirect
1677 primary base, then we can move on to the next virtual
1678 base. */
1681 }
1682 }
1684 /* A "nearly-empty" virtual base class can be the primary base
1685 class, if no non-virtual polymorphic base can be found. */
1687 {
1688 /* If not NULL, this is the best primary base candidate we have
1689 found so far. */
1691 tree base_binfo;
1693 /* Loop over the baseclasses. */
1695 base_binfo;
1697 {
1702 {
1703 /* If this is not an indirect primary base, then it's
1704 definitely our primary base. */
1706 {
1709 }
1711 /* If this is an indirect primary base, it still could be
1712 our primary base -- unless we later find there's another
1713 nearly-empty virtual base that isn't an indirect
1714 primary base. */
1717 }
1718 }
1720 /* If we've got a primary base, use it. */
1722 {
1726 }
1727 }
1729 /* Mark the primary base classes at this point. */
1731 }
1732 \f
1733 /* Set memoizing fields and bits of T (and its variants) for later
1734 use. */
1736 static void
1738 tree t;
1739 {
1742 /* Fix up variants (if any). */
1745 {
1746 /* These fields are in the _TYPE part of the node, not in
1747 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1758 /* Copy whatever these are holding today. */
1765 }
1768 /* For a class w/o baseclasses, `finish_struct' has set
1769 CLASS_TYPE_ABSTRACT_VIRTUALS correctly (by
1770 definition). Similarly for a class whose base classes do not
1771 have vtables. When neither of these is true, we might have
1772 removed abstract virtuals (by providing a definition), added
1773 some (by declaring new ones), or redeclared ones from a base
1774 class. We need to recalculate what's really an abstract virtual
1775 at this point (by looking in the vtables). */
1779 {
1780 /* Notice whether this class has type conversion functions defined. */
1783 tree basetype;
1786 {
1790 }
1791 }
1793 /* If this type has a copy constructor or a destructor, force its mode to
1794 be BLKmode, and force its TREE_ADDRESSABLE bit to be nonzero. This
1795 will cause it to be passed by invisible reference and prevent it from
1796 being returned in a register. */
1798 {
1799 tree variants;
1802 {
1805 }
1806 }
1807 }
1809 /* Issue warnings about T having private constructors, but no friends,
1810 and so forth.
1812 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1813 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1814 non-private static member functions. */
1816 static void
1818 tree t;
1819 {
1822 tree fn;
1825 /* If the class has friends, those entities might create and
1826 access instances, so we should not warn. */
1829 /* We will have warned when the template was declared; there's
1830 no need to warn on every instantiation. */
1832 /* There's no reason to even consider warning about this
1833 class. */
1836 /* We only issue one warning, if more than one applies, because
1837 otherwise, on code like:
1839 class A {
1840 // Oops - forgot `public:'
1841 A();
1842 A(const A&);
1843 ~A();
1844 };
1846 we warn several times about essentially the same problem. */
1848 /* Check to see if all (non-constructor, non-destructor) member
1849 functions are private. (Since there are no friends or
1850 non-private statics, we can't ever call any of the private member
1851 functions.) */
1853 /* We're not interested in compiler-generated methods; they don't
1854 provide any way to call private members. */
1856 {
1858 {
1860 /* A non-private static member function is just like a
1861 friend; it can create and invoke private member
1862 functions, and be accessed without a class
1863 instance. */
1868 }
1871 }
1874 {
1875 /* There are no non-private methods, and there's at least one
1876 private member function that isn't a constructor or
1877 destructor. (If all the private members are
1878 constructors/destructors we want to use the code below that
1879 issues error messages specifically referring to
1880 constructors/destructors.) */
1886 {
1889 }
1891 {
1894 }
1895 }
1897 /* Even if some of the member functions are non-private, the class
1898 won't be useful for much if all the constructors or destructors
1899 are private: such an object can never be created or destroyed. */
1901 {
1905 {
1907 t);
1909 }
1910 }
1913 {
1916 /* If a non-template class does not define a copy
1917 constructor, one is defined for it, enabling it to avoid
1918 this warning. For a template class, this does not
1919 happen, and so we would normally get a warning on:
1921 template <class T> class C { private: C(); };
1923 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1924 complete non-template or fully instantiated classes have this
1925 flag set. */
1928 else
1930 fn;
1932 {
1934 /* Ideally, we wouldn't count copy constructors (or, in
1935 fact, any constructor that takes an argument of the
1936 class type as a parameter) because such things cannot
1937 be used to construct an instance of the class unless
1938 you already have one. But, for now at least, we're
1939 more generous. */
1941 {
1944 }
1945 }
1948 {
1950 t);
1952 }
1953 }
1954 }
1956 /* Function to help qsort sort FIELD_DECLs by name order. */
1958 static int
1961 {
1963 /* A nontype is "greater" than a type. */
1972 }
1974 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1976 static int
1979 {
1989 }
1991 /* Warn about duplicate methods in fn_fields. Also compact method
1992 lists so that lookup can be made faster.
1994 Data Structure: List of method lists. The outer list is a
1995 TREE_LIST, whose TREE_PURPOSE field is the field name and the
1996 TREE_VALUE is the DECL_CHAIN of the FUNCTION_DECLs. TREE_CHAIN
1997 links the entire list of methods for TYPE_METHODS. Friends are
1998 chained in the same way as member functions (? TREE_CHAIN or
1999 DECL_CHAIN), but they live in the TREE_TYPE field of the outer
2000 list. That allows them to be quickly deleted, and requires no
2001 extra storage.
2003 Sort methods that are not special (i.e., constructors, destructors,
2004 and type conversion operators) so that we can find them faster in
2005 search. */
2007 static void
2009 tree t;
2010 {
2011 tree fn_fields;
2012 tree method_vec;
2016 {
2017 /* Clear these for safety; perhaps some parsing error could set
2018 these incorrectly. */
2023 }
2029 /* First fill in entry 0 with the constructors, entry 1 with destructors,
2030 and the next few with type conversion operators (if any). */
2033 /* Clear out this flag. */
2037 /* We thought there was a destructor, but there wasn't. Some
2038 parse errors cause this anomalous situation. */
2041 /* Issue warnings about private constructors and such. If there are
2042 no methods, then some public defaults are generated. */
2045 /* Now sort the methods. */
2047 len--;
2050 /* The type conversion ops have to live at the front of the vec, so we
2051 can't sort them. */
2053 {
2058 }
2062 }
2064 /* Emit error when a duplicate definition of a type is seen. Patch up. */
2066 void
2068 tree t;
2069 {
2073 /* Pretend we haven't defined this type. */
2075 /* All of the component_decl's were TREE_CHAINed together in the parser.
2076 finish_struct_methods walks these chains and assembles all methods with
2077 the same base name into DECL_CHAINs. Now we don't need the parser chains
2078 anymore, so we unravel them. */
2080 /* This used to be in finish_struct, but it turns out that the
2081 TREE_CHAIN is used by dbxout_type_methods and perhaps some other
2082 things... */
2084 {
2088 {
2091 {
2094 }
2095 }
2096 }
2099 {
2116 }
2124 /* Clear TYPE_LANG_FLAGS -- those in TYPE_LANG_SPECIFIC are cleared above. */
2132 /* But not this one. */
2134 }
2136 /* Make BINFO's vtable have N entries, including RTTI entries,
2137 vbase and vcall offsets, etc. Set its type and call the backend
2138 to lay it out. */
2140 static void
2142 tree binfo;
2144 {
2145 tree atype;
2146 tree vtable;
2152 /* We may have to grow the vtable. */
2155 {
2160 /* At one time the vtable info was grabbed 2 words at a time. This
2161 fails on Sparc unless you have 8-byte alignment. */
2164 }
2165 }
2167 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2168 have the same signature. */
2170 int
2173 {
2174 /* One destructor overrides another if they are the same kind of
2175 destructor. */
2179 /* But a non-destructor never overrides a destructor, nor vice
2180 versa, nor do different kinds of destructors override
2181 one-another. For example, a complete object destructor does not
2182 override a deleting destructor. */
2187 {
2195 }
2197 }
2200 /* The function for which we are trying to find a final overrider. */
2201 tree fn;
2202 /* The base class in which the function was declared. */
2203 tree declaring_base;
2204 /* The most derived class in the hierarchy. */
2205 tree most_derived_type;
2206 /* The final overriding function. */
2207 tree overriding_fn;
2208 /* The functions that we thought might be final overriders, but
2209 aren't. */
2210 tree candidates;
2211 /* The BINFO for the class in which the final overriding function
2212 appears. */
2213 tree overriding_base;
2216 /* Called from find_final_overrider via dfs_walk. */
2218 static tree
2220 tree binfo;
2222 {
2229 {
2230 tree path;
2231 tree method;
2233 /* We haven't found an overrider yet. */
2235 /* We've found a path to the declaring base. Walk down the path
2236 looking for an overrider for FN. */
2238 path;
2240 {
2245 }
2247 /* If we found an overrider, record the overriding function, and
2248 the base from which it came. */
2250 {
2251 tree base;
2253 /* Assume the path is non-virtual. See if there are any
2254 virtual bases from (but not including) the overrider up
2255 to and including the base where the function is
2256 defined. */
2259 {
2262 }
2264 /* If we didn't already have an overrider, or any
2265 candidates, then this function is the best candidate so
2266 far. */
2268 {
2271 }
2273 {
2274 /* We had a best overrider; let's see how this compares. */
2277 && (tree_int_cst_equal
2280 /* We found the same overrider we already have, and in the
2283 /* The old function overrides this function; it's still the
2286 {
2287 /* The new function overrides the old; it's now the
2288 best. */
2291 }
2292 else
2293 {
2294 /* Ambiguous. */
2295 ffod->candidates
2299 ffod->candidates
2303 }
2304 }
2305 else
2306 {
2307 /* We had a list of ambiguous overrides; let's see how this
2308 new one compares. */
2310 tree candidates;
2313 /* If there were previous candidates, and this function
2314 overrides all of them, then it is the new best
2315 candidate. */
2317 candidates;
2319 {
2320 /* If the candidate overrides the METHOD, then we
2321 needn't worry about it any further. */
2323 method))
2324 {
2327 }
2329 /* If the METHOD doesn't override the candidate,
2330 then it is incomporable. */
2334 }
2336 /* If METHOD overrode all the candidates, then it is the
2337 new best candidate. */
2339 {
2343 }
2344 /* If METHOD didn't override all the candidates, then it
2345 is another candidate. */
2347 ffod->candidates
2349 }
2350 }
2351 }
2354 }
2356 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2357 FN and whose TREE_VALUE is the binfo for the base where the
2358 overriding occurs. BINFO (in the hierarchy dominated by T) is the
2359 base object in which FN is declared. */
2361 static tree
2363 tree t;
2364 tree binfo;
2365 tree fn;
2366 {
2367 find_final_overrider_data ffod;
2369 /* Getting this right is a little tricky. This is valid:
2371 struct S { virtual void f (); };
2372 struct T { virtual void f (); };
2373 struct U : public S, public T { };
2375 even though calling `f' in `U' is ambiguous. But,
2377 struct R { virtual void f(); };
2378 struct S : virtual public R { virtual void f (); };
2379 struct T : virtual public R { virtual void f (); };
2380 struct U : public S, public T { };
2382 is not -- there's no way to decide whether to put `S::f' or
2383 `T::f' in the vtable for `R'.
2385 The solution is to look at all paths to BINFO. If we find
2386 different overriders along any two, then there is a problem. */
2395 dfs_find_final_overrider,
2396 NULL,
2399 /* If there was no winner, issue an error message. */
2401 {
2404 }
2407 }
2409 /* Returns the function from the BINFO_VIRTUALS entry in T which matches
2410 the signature of FUNCTION_DECL FN, or NULL_TREE if none. In other words,
2411 the function that the slot in T's primary vtable points to. */
2414 static tree
2417 {
2418 tree f;
2424 }
2426 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2427 dominated by T. FN has been overriden in BINFO; VIRTUALS points to the
2428 corresponding position in the BINFO_VIRTUALS list. */
2430 static void
2432 tree t;
2433 tree binfo;
2434 tree fn;
2436 {
2437 tree b;
2438 tree overrider;
2439 tree delta;
2440 tree virtual_base;
2441 tree first_defn;
2444 /* Find the nearest primary base (possibly binfo itself) which defines
2445 this function; this is the class the caller will convert to when
2446 calling FN through BINFO. */
2448 {
2452 /* The nearest definition is from a lost primary. */
2455 }
2458 /* Find the final overrider. */
2463 /* Check for unsupported covariant returns again now that we've
2464 calculated the base offsets. */
2467 /* Assume that we will produce a thunk that convert all the way to
2468 the final overrider, and not to an intermediate virtual base. */
2471 /* See if we can convert to an intermediate virtual base first, and then
2472 use the vcall offset located there to finish the conversion. */
2474 {
2475 /* If we find the final overrider, then we can stop
2476 walking. */
2481 /* If we find a virtual base, and we haven't yet found the
2482 overrider, then there is a virtual base between the
2483 declaring base (first_defn) and the final overrider. */
2486 }
2488 /* Compute the constant adjustment to the `this' pointer. The
2489 `this' pointer, when this function is called, will point at BINFO
2490 (or one of its primary bases, which are at the same offset). */
2493 /* The `this' pointer needs to be adjusted from the declaration to
2494 the nearest virtual base. */
2498 /* If the nearest definition is in a lost primary, we don't need an
2499 entry in our vtable. Except possibly in a constructor vtable,
2500 if we happen to get our primary back. In that case, the offset
2501 will be zero, as it will be a primary base. */
2503 else
2504 {
2505 /* The `this' pointer needs to be adjusted from pointing to
2506 BINFO to pointing at the base where the final overrider
2507 appears. */
2512 {
2513 /* We'll need a thunk. But if we have a (perhaps formerly)
2514 primary virtual base, we have a vcall slot for this function,
2515 so we can use it rather than create a non-virtual thunk. */
2519 {
2522 /* b doesn't have this function; no suitable vbase. */
2525 {
2526 /* Found one; we can treat ourselves as a virtual base. */
2530 }
2531 }
2532 }
2533 }
2536 binfo,
2538 delta,
2539 virtuals);
2543 }
2545 /* Called from modify_all_vtables via dfs_walk. */
2547 static tree
2549 tree binfo;
2551 {
2553 primary base; we're not going to use that vtable anyhow.
2554 We do still need to do this for virtual primary bases, as they
2555 could become non-primary in a construction vtable. */
2557 /* Similarly, a base without a vtable needs no modification. */
2559 {
2560 tree t;
2561 tree virtuals;
2562 tree old_virtuals;
2568 /* Now, go through each of the virtual functions in the virtual
2569 function table for BINFO. Find the final overrider, and
2570 update the BINFO_VIRTUALS list appropriately. */
2573 virtuals;
2577 binfo,
2580 }
2585 }
2587 /* Update all of the primary and secondary vtables for T. Create new
2588 vtables as required, and initialize their RTTI information. Each
2589 of the functions in VIRTUALS is declared in T and may override a
2590 virtual function from a base class; find and modify the appropriate
2591 entries to point to the overriding functions. Returns a list, in
2592 declaration order, of the virtual functions that are declared in T,
2593 but do not appear in the primary base class vtable, and which
2594 should therefore be appended to the end of the vtable for T. */
2596 static tree
2598 tree t;
2600 tree virtuals;
2601 {
2605 /* Update all of the vtables. */
2607 dfs_modify_vtables,
2608 dfs_unmarked_real_bases_queue_p,
2609 t);
2612 /* Add virtual functions not already in our primary vtable. These
2613 will be both those introduced by this class, and those overridden
2614 from secondary bases. It does not include virtuals merely
2615 inherited from secondary bases. */
2617 {
2622 {
2623 /* Set the vtable index. */
2625 /* We don't need to convert to a base class when calling
2626 this function. */
2629 /* We don't need to adjust the `this' pointer when
2630 calling this function. */
2634 /* This is a function not already in our vtable. Keep it. */
2636 }
2637 else
2638 /* We've already got an entry for this function. Skip it. */
2640 }
2643 }
2645 /* Here, we already know that they match in every respect.
2646 All we have to check is where they had their declarations.
2648 Return non-zero iff FNDECL1 is declared in a class which has a
2649 proper base class containing FNDECL2. We don't care about
2650 ambiguity or accessibility. */
2652 static int
2655 {
2656 base_kind kind;
2661 }
2663 /* Get the base virtual function declarations in T that have the
2664 indicated NAME. */
2666 static tree
2669 {
2670 tree methods;
2685 {
2688 base_fndecls);
2689 }
2692 }
2694 /* If this declaration supersedes the declaration of
2695 a method declared virtual in the base class, then
2696 mark this field as being virtual as well. */
2698 static void
2701 {
2703 /* In [temp.mem] we have:
2705 A specialization of a member function template does not
2706 override a virtual function from a base class. */
2712 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2713 the error_mark_node so that we know it is an overriding
2714 function. */
2718 {
2722 }
2723 }
2725 /* Warn about hidden virtual functions that are not overridden in t.
2726 We know that constructors and destructors don't apply. */
2728 void
2730 tree t;
2731 {
2736 /* We go through each separately named virtual function. */
2738 {
2739 tree fns;
2740 tree name;
2741 tree fndecl;
2742 tree base_fndecls;
2745 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2746 have the same name. Figure out what name that is. */
2748 /* There are no possibly hidden functions yet. */
2750 /* Iterate through all of the base classes looking for possibly
2751 hidden functions. */
2753 {
2756 base_fndecls);
2757 }
2759 /* If there are no functions to hide, continue. */
2763 /* Remove any overridden functions. */
2765 {
2768 {
2772 /* If the method from the base class has the same
2773 signature as the method from the derived class, it
2774 has been overridden. */
2777 else
2779 }
2780 }
2782 /* Now give a warning for all base functions without overriders,
2783 as they are hidden. */
2785 {
2786 /* Here we know it is a hider, and no overrider exists. */
2791 }
2792 }
2793 }
2795 /* Check for things that are invalid. There are probably plenty of other
2796 things we should check for also. */
2798 static void
2800 tree t;
2801 {
2802 tree field;
2805 {
2813 {
2816 {
2817 /* We're generally only interested in entities the user
2818 declared, but we also find nested classes by noticing
2819 the TYPE_DECL that we create implicitly. You're
2820 allowed to put one anonymous union inside another,
2821 though, so we explicitly tolerate that. We use
2822 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2823 we also allow unnamed types used for defining fields. */
2831 elt);
2834 {
2836 elt);
2838 }
2842 elt);
2845 elt);
2849 }
2850 }
2851 }
2852 }
2854 /* Create default constructors, assignment operators, and so forth for
2855 the type indicated by T, if they are needed.
2856 CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2857 CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2858 class cannot have a default constructor, copy constructor taking a
2859 const reference argument, or an assignment operator taking a const
2860 reference, respectively. If a virtual destructor is created, its
2861 DECL is returned; otherwise the return value is NULL_TREE. */
2863 static tree
2865 cant_have_const_cctor,
2866 cant_have_const_assignment)
2867 tree t;
2871 {
2872 tree default_fn;
2879 /* Destructor. */
2881 {
2885 /* If we couldn't make it work, then pretend we didn't need it. */
2888 else
2889 {
2895 }
2896 }
2897 else
2898 /* Any non-implicit destructor is non-trivial. */
2901 /* Default constructor. */
2903 {
2907 }
2909 /* Copy constructor. */
2911 {
2912 /* ARM 12.18: You get either X(X&) or X(const X&), but
2913 not both. --Chip */
2914 default_fn
2919 }
2921 /* Assignment operator. */
2923 {
2924 default_fn
2929 }
2931 /* Now, hook all of the new functions on to TYPE_METHODS,
2932 and add them to the CLASSTYPE_METHOD_VEC. */
2941 }
2943 /* Subroutine of finish_struct_1. Recursively count the number of fields
2944 in TYPE, including anonymous union members. */
2946 static int
2948 tree fields;
2949 {
2950 tree x;
2953 {
2956 else
2958 }
2960 }
2962 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2963 TREE_LIST FIELDS to the TREE_VEC FIELD_VEC, starting at offset IDX. */
2965 static int
2969 {
2970 tree x;
2972 {
2975 else
2977 }
2979 }
2981 /* FIELD is a bit-field. We are finishing the processing for its
2982 enclosing type. Issue any appropriate messages and set appropriate
2983 flags. */
2985 static void
2987 tree field;
2988 {
2992 /* Detect invalid bit-field type. */
2995 {
2998 }
3000 /* Detect and ignore out of range field width. */
3002 {
3005 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3008 /* detect invalid field size. */
3011 else
3015 {
3017 field);
3019 }
3021 {
3024 }
3026 {
3029 }
3039 min_precision
3044 }
3046 /* Remove the bit-field width indicator so that the rest of the
3047 compiler does not treat that value as an initializer. */
3051 {
3057 {
3058 #ifdef EMPTY_FIELD_BOUNDARY
3060 EMPTY_FIELD_BOUNDARY);
3061 #endif
3062 #ifdef PCC_BITFIELD_TYPE_MATTERS
3064 {
3068 }
3069 #endif
3070 }
3071 }
3072 else
3073 {
3074 /* Non-bit-fields are aligned for their type. */
3079 }
3080 }
3082 /* FIELD is a non bit-field. We are finishing the processing for its
3083 enclosing type T. Issue any appropriate messages and set appropriate
3084 flags. */
3086 static void
3089 any_default_members)
3090 tree field;
3091 tree t;
3096 {
3099 /* An anonymous union cannot contain any fields which would change
3100 the settings of CANT_HAVE_CONST_CTOR and friends. */
3102 ;
3103 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
3104 structs. So, we recurse through their fields here. */
3106 {
3107 tree fields;
3113 any_default_members);
3114 }
3115 /* Check members with class type for constructors, destructors,
3116 etc. */
3118 {
3119 /* Never let anything with uninheritable virtuals
3120 make it through without complaint. */
3124 {
3127 field);
3130 field);
3133 field);
3134 }
3135 else
3136 {
3142 }
3153 }
3155 {
3156 /* `build_class_init_list' does not recognize
3157 non-FIELD_DECLs. */
3161 }
3163 /* Non-bit-fields are aligned for their type, except packed fields
3164 which require only BITS_PER_UNIT alignment. */
3167 ? BITS_PER_UNIT
3171 }
3173 /* Check the data members (both static and non-static), class-scoped
3174 typedefs, etc., appearing in the declaration of T. Issue
3175 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3176 declaration order) of access declarations; each TREE_VALUE in this
3177 list is a USING_DECL.
3179 In addition, set the following flags:
3181 EMPTY_P
3182 The class is empty, i.e., contains no non-static data members.
3184 CANT_HAVE_DEFAULT_CTOR_P
3185 This class cannot have an implicitly generated default
3186 constructor.
3188 CANT_HAVE_CONST_CTOR_P
3189 This class cannot have an implicitly generated copy constructor
3190 taking a const reference.
3192 CANT_HAVE_CONST_ASN_REF
3193 This class cannot have an implicitly generated assignment
3194 operator taking a const reference.
3196 All of these flags should be initialized before calling this
3197 function.
3199 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3200 fields can be added by adding to this chain. */
3202 static void
3205 no_const_asn_ref_p)
3206 tree t;
3212 {
3218 /* First, delete any duplicate fields. */
3221 /* Assume there are no access declarations. */
3223 /* Assume this class has no pointer members. */
3225 /* Assume none of the members of this class have default
3226 initializations. */
3230 {
3237 {
3241 /* We don't treat zero-width bitfields as making a class
3242 non-empty. */
3243 ;
3244 else
3245 {
3246 /* The class is non-empty. */
3248 /* The class is not even nearly empty. */
3250 }
3251 }
3254 {
3255 /* Prune the access declaration from the list of fields. */
3258 /* Save the access declarations for our caller. */
3261 /* Since we've reset *FIELD there's no reason to skip to the
3262 next field. */
3265 }
3271 /* If we've gotten this far, it's a data member, possibly static,
3272 or an enumerator. */
3276 /* ``A local class cannot have static data members.'' ARM 9.4 */
3280 /* Perform error checking that did not get done in
3281 grokdeclarator. */
3283 {
3285 x);
3288 }
3290 {
3294 }
3296 {
3300 }
3305 /* When this goes into scope, it will be a non-local reference. */
3312 {
3314 /* Unions cannot have static members. */
3318 }
3320 /* Now it can only be a FIELD_DECL. */
3325 /* If this is of reference type, check if it needs an init.
3326 Also do a little ANSI jig if necessary. */
3328 {
3333 /* ARM $12.6.2: [A member initializer list] (or, for an
3334 aggregate, initialization by a brace-enclosed list) is the
3335 only way to initialize nonstatic const and reference
3336 members. */
3342 }
3353 /* DR 148 now allows pointers to members (which are POD themselves),
3354 to be allowed in POD structs. */
3360 /* If any field is const, the structure type is pseudo-const. */
3362 {
3367 /* ARM $12.6.2: [A member initializer list] (or, for an
3368 aggregate, initialization by a brace-enclosed list) is the
3369 only way to initialize nonstatic const and reference
3370 members. */
3376 }
3377 /* A field that is pseudo-const makes the structure likewise. */
3379 {
3383 }
3385 /* Core issue 80: A nonstatic data member is required to have a
3386 different name from the class iff the class has a
3387 user-defined constructor. */
3392 /* We set DECL_C_BIT_FIELD in grokbitfield.
3393 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3396 else
3398 cant_have_const_ctor_p,
3399 cant_have_default_ctor_p,
3400 no_const_asn_ref_p,
3402 }
3404 /* Effective C++ rule 11. */
3407 {
3411 {
3415 }
3418 }
3421 /* Check anonymous struct/anonymous union fields. */
3424 /* We've built up the list of access declarations in reverse order.
3425 Fix that now. */
3427 }
3429 /* If TYPE is an empty class type, records its OFFSET in the table of
3430 OFFSETS. */
3432 static int
3434 tree type;
3435 tree offset;
3436 splay_tree offsets;
3437 {
3438 splay_tree_node n;
3443 /* Record the location of this empty object in OFFSETS. */
3451 type,
3455 }
3457 /* Returns non-zero if TYPE is an empty class type and there is
3458 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3460 static int
3462 tree type;
3463 tree offset;
3464 splay_tree offsets;
3465 {
3466 splay_tree_node n;
3467 tree t;
3472 /* Record the location of this empty object in OFFSETS. */
3482 }
3484 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3485 F for every subobject, passing it the type, offset, and table of
3486 OFFSETS. If VBASES_P is non-zero, then even virtual non-primary
3487 bases should be traversed; otherwise, they are ignored.
3489 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3490 than MAX_OFFSET will not be walked.
3492 If F returns a non-zero value, the traversal ceases, and that value
3493 is returned. Otherwise, returns zero. */
3495 static int
3497 tree type;
3498 subobject_offset_fn f;
3499 tree offset;
3500 splay_tree offsets;
3501 tree max_offset;
3503 {
3506 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3507 stop. */
3512 {
3513 tree field;
3516 /* Record the location of TYPE. */
3521 /* Iterate through the direct base classes of TYPE. */
3523 {
3532 f,
3534 offset,
3536 offsets,
3537 max_offset,
3538 vbases_p);
3541 }
3543 /* Iterate through the fields of TYPE. */
3546 {
3548 f,
3550 offset,
3552 offsets,
3553 max_offset,
3557 }
3558 }
3560 {
3562 tree index;
3564 /* Step through each of the elements in the array. */
3568 {
3570 f,
3571 offset,
3572 offsets,
3573 max_offset,
3579 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3580 there's no point in iterating through the remaining
3581 elements of the array. */
3584 }
3585 }
3588 }
3590 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3591 OFFSETS. If VBASES_P is non-zero, virtual bases of TYPE are
3592 examined. */
3594 static void
3596 tree type;
3597 tree offset;
3598 splay_tree offsets;
3600 {
3603 }
3605 /* Returns non-zero if any of the empty subobjects of TYPE (located at
3606 OFFSET) conflict with entries in OFFSETS. If VBASES_P is non-zero,
3607 virtual bases of TYPE are examined. */
3609 static int
3611 tree type;
3612 tree offset;
3613 splay_tree offsets;
3615 {
3616 splay_tree_node max_node;
3618 /* Get the node in OFFSETS that indicates the maximum offset where
3619 an empty subobject is located. */
3621 /* If there aren't any empty subobjects, then there's no point in
3622 performing this check. */
3628 vbases_p);
3629 }
3631 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3632 non-static data member of the type indicated by RLI. BINFO is the
3633 binfo corresponding to the base subobject, OFFSETS maps offsets to
3634 types already located at those offsets. T is the most derived
3635 type. This function determines the position of the DECL. */
3637 static void
3639 record_layout_info rli;
3640 tree decl;
3641 tree binfo;
3642 splay_tree offsets;
3643 tree t;
3644 {
3647 /* If we are laying out a base class, rather than a field, then
3648 DECL_ARTIFICIAL will be set on the FIELD_DECL. */
3651 /* Try to place the field. It may take more than one try if we have
3652 a hard time placing the field without putting two objects of the
3653 same type at the same address. */
3655 {
3658 /* Place this field. */
3662 /* We have to check to see whether or not there is already
3663 something of the same type at the offset we're about to use.
3664 For example:
3666 struct S {};
3667 struct T : public S { int i; };
3668 struct U : public S, public T {};
3670 Here, we put S at offset zero in U. Then, we can't put T at
3671 offset zero -- its S component would be at the same address
3672 as the S we already allocated. So, we have to skip ahead.
3673 Since all data members, including those whose type is an
3674 empty class, have non-zero size, any overlap can happen only
3675 with a direct or indirect base-class -- it can't happen with
3676 a data member. */
3678 offset,
3679 offsets,
3680 field_p))
3681 {
3682 /* Strip off the size allocated to this field. That puts us
3683 at the first place we could have put the field with
3684 proper alignment. */
3687 /* Bump up by the alignment required for the type. */
3688 rli->bitpos
3694 }
3695 else
3696 /* There was no conflict. We're done laying out this field. */
3698 }
3700 /* Now that we know where it will be placed, update its
3701 BINFO_OFFSET. */
3705 }
3707 /* Layout the empty base BINFO. EOC indicates the byte currently just
3708 past the end of the class, and should be correctly aligned for a
3709 class of the type indicated by BINFO; OFFSETS gives the offsets of
3710 the empty bases allocated so far. T is the most derived
3711 type. Return non-zero iff we added it at the end. */
3713 static bool
3715 tree binfo;
3716 tree eoc;
3717 splay_tree offsets;
3718 tree t;
3719 {
3720 tree alignment;
3724 /* This routine should only be used for empty classes. */
3728 /* This is an empty base class. We first try to put it at offset
3729 zero. */
3732 offsets,
3734 {
3735 /* That didn't work. Now, we move forward from the next
3736 available spot in the class. */
3740 {
3743 offsets,
3745 /* We finally found a spot where there's no overlap. */
3748 /* There's overlap here, too. Bump along to the next spot. */
3750 }
3751 }
3753 }
3755 /* Build a FIELD_DECL for the base given by BINFO in the class
3756 indicated by RLI. If the new object is non-empty, clear *EMPTY_P.
3757 *BASE_ALIGN is a running maximum of the alignments of any base
3758 class. OFFSETS gives the location of empty base subobjects. T is
3759 the most derived type. Return non-zero if the new object cannot be
3760 nearly-empty. */
3762 static bool
3764 record_layout_info rli;
3765 tree binfo;
3767 splay_tree offsets;
3768 tree t;
3769 {
3771 tree decl;
3775 /* This error is now reported in xref_tag, thus giving better
3776 location information. */
3786 /* Tell the backend not to round up to TYPE_ALIGN. */
3790 {
3791 /* The containing class is non-empty because it has a non-empty
3792 base class. */
3795 /* Try to place the field. It may take more than one try if we
3796 have a hard time placing the field without putting two
3797 objects of the same type at the same address. */
3799 }
3800 else
3801 {
3804 /* On some platforms (ARM), even empty classes will not be
3805 byte-aligned. */
3809 }
3811 /* Record the offsets of BINFO and its base subobjects. */
3814 offsets,
3817 }
3819 /* Layout all of the non-virtual base classes. Record empty
3820 subobjects in OFFSETS. T is the most derived type. Return
3821 non-zero if the type cannot be nearly empty. */
3823 static bool
3825 record_layout_info rli;
3827 splay_tree offsets;
3828 tree t;
3829 {
3830 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3831 subobjects. */
3837 /* The primary base class is always allocated first. */
3842 /* Now allocate the rest of the bases. */
3844 {
3845 tree base_binfo;
3849 /* The primary base was already allocated above, so we don't
3850 need to allocate it again here. */
3854 /* A primary virtual base class is allocated just like any other
3855 base class, but a non-primary virtual base is allocated
3856 later, in layout_virtual_bases. */
3862 }
3864 }
3866 /* Go through the TYPE_METHODS of T issuing any appropriate
3867 diagnostics, figuring out which methods override which other
3868 methods, and so forth. */
3870 static void
3872 tree t;
3873 {
3874 tree x;
3877 {
3878 /* If this was an evil function, don't keep it in class. */
3887 /* The name of the field is the original field name
3888 Save this in auxiliary field for later overloading. */
3890 {
3895 }
3896 }
3897 }
3899 /* FN is a constructor or destructor. Clone the declaration to create
3900 a specialized in-charge or not-in-charge version, as indicated by
3901 NAME. */
3903 static tree
3905 tree fn;
3906 tree name;
3907 {
3908 tree parms;
3909 tree clone;
3911 /* Copy the function. */
3913 /* Remember where this function came from. */
3916 /* Reset the function name. */
3919 /* There's no pending inline data for this function. */
3922 /* And it hasn't yet been deferred. */
3925 /* The base-class destructor is not virtual. */
3927 {
3931 }
3933 /* If there was an in-charge parameter, drop it from the function
3934 type. */
3936 {
3937 tree basetype;
3938 tree parmtypes;
3939 tree exceptions;
3944 /* Skip the `this' parameter. */
3946 /* Skip the in-charge parameter. */
3948 /* And the VTT parm, in a complete [cd]tor. */
3952 /* If this is subobject constructor or destructor, add the vtt
3953 parameter. */
3957 parmtypes);
3960 exceptions);
3961 }
3963 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3964 aren't function parameters; those are the template parameters. */
3966 {
3968 /* Remove the in-charge parameter. */
3970 {
3974 }
3975 /* And the VTT parm, in a complete [cd]tor. */
3977 {
3980 else
3981 {
3985 }
3986 }
3989 {
3992 }
3993 }
3995 /* Create the RTL for this function. */
3999 /* Make it easy to find the CLONE given the FN. */
4003 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
4005 {
4006 tree result;
4013 }
4018 }
4020 /* Produce declarations for all appropriate clones of FN. If
4021 UPDATE_METHOD_VEC_P is non-zero, the clones are added to the
4022 CLASTYPE_METHOD_VEC as well. */
4024 void
4026 tree fn;
4028 {
4029 tree clone;
4031 /* Avoid inappropriate cloning. */
4037 {
4038 /* For each constructor, we need two variants: an in-charge version
4039 and a not-in-charge version. */
4046 }
4047 else
4048 {
4051 /* For each destructor, we need three variants: an in-charge
4052 version, a not-in-charge version, and an in-charge deleting
4053 version. We clone the deleting version first because that
4054 means it will go second on the TYPE_METHODS list -- and that
4055 corresponds to the correct layout order in the virtual
4056 function table.
4058 For a non-virtual destructor, we do not build a deleting
4059 destructor. */
4061 {
4065 }
4072 }
4074 /* Note that this is an abstract function that is never emitted. */
4076 }
4078 /* DECL is an in charge constructor, which is being defined. This will
4079 have had an in class declaration, from whence clones were
4080 declared. An out-of-class definition can specify additional default
4081 arguments. As it is the clones that are involved in overload
4082 resolution, we must propagate the information from the DECL to its
4083 clones. */
4085 void
4087 tree decl;
4088 {
4089 tree clone;
4093 {
4100 /* Skip the 'this' parameter. */
4116 {
4121 {
4122 /* A default parameter has been added. Adjust the
4123 clone's parameters. */
4126 tree type;
4131 {
4134 clone_parms);
4136 }
4139 clone_parms);
4146 }
4147 }
4149 }
4150 }
4152 /* For each of the constructors and destructors in T, create an
4153 in-charge and not-in-charge variant. */
4155 static void
4157 tree t;
4158 {
4159 tree fns;
4161 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4162 out now. */
4170 }
4172 /* Remove all zero-width bit-fields from T. */
4174 static void
4176 tree t;
4177 {
4182 {
4187 else
4189 }
4190 }
4192 /* Returns TRUE iff we need a cookie when dynamically allocating an
4193 array whose elements have the indicated class TYPE. */
4195 static bool
4197 tree type;
4198 {
4199 tree fns;
4204 /* If there's a non-trivial destructor, we need a cookie. In order
4205 to iterate through the array calling the destructor for each
4206 element, we'll have to know how many elements there are. */
4210 /* If the usual deallocation function is a two-argument whose second
4211 argument is of type `size_t', then we have to pass the size of
4212 the array to the deallocation function, so we will need to store
4213 a cookie. */
4217 /* If there are no `operator []' members, or the lookup is
4218 ambiguous, then we don't need a cookie. */
4221 /* Loop through all of the functions. */
4223 {
4224 tree fn;
4225 tree second_parm;
4227 /* Select the current function. */
4229 /* See if this function is a one-argument delete function. If
4230 it is, then it will be the usual deallocation function. */
4234 /* Otherwise, if we have a two-argument function and the second
4235 argument is `size_t', it will be the usual deallocation
4236 function -- unless there is one-argument function, too. */
4240 }
4243 }
4245 /* Check the validity of the bases and members declared in T. Add any
4246 implicitly-generated functions (like copy-constructors and
4247 assignment operators). Compute various flag bits (like
4248 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4249 level: i.e., independently of the ABI in use. */
4251 static void
4253 tree t;
4255 {
4256 /* Nonzero if we are not allowed to generate a default constructor
4257 for this case. */
4259 /* Nonzero if the implicitly generated copy constructor should take
4260 a non-const reference argument. */
4262 /* Nonzero if the the implicitly generated assignment operator
4263 should take a non-const reference argument. */
4265 tree access_decls;
4267 /* By default, we use const reference arguments and generate default
4268 constructors. */
4273 /* Assume that the class is nearly empty; we'll clear this flag if
4274 it turns out not to be nearly empty. */
4277 /* Check all the base-classes. */
4281 /* Check all the data member declarations. */
4287 /* Check all the method declarations. */
4290 /* A nearly-empty class has to be vptr-containing; a nearly empty
4291 class contains just a vptr. */
4295 /* Do some bookkeeping that will guide the generation of implicitly
4296 declared member functions. */
4314 /* Synthesize any needed methods. Note that methods will be synthesized
4315 for anonymous unions; grok_x_components undoes that. */
4317 cant_have_const_ctor,
4318 no_const_asn_ref);
4320 /* Create the in-charge and not-in-charge variants of constructors
4321 and destructors. */
4324 /* Process the using-declarations. */
4328 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4331 /* Figure out whether or not we will need a cookie when dynamically
4332 allocating an array of this type. */
4335 }
4337 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4338 accordingly. If a new vfield was created (because T doesn't have a
4339 primary base class), then the newly created field is returned. It
4340 is not added to the TYPE_FIELDS list; it is the caller's
4341 responsibility to do that. Accumulate declared virtual functions
4342 on VIRTUALS_P. */
4344 static tree
4346 tree t;
4349 {
4350 tree fn;
4352 /* Collect the virtual functions declared in T. */
4356 {
4364 }
4366 /* If we couldn't find an appropriate base class, create a new field
4367 here. Even if there weren't any new virtual functions, we might need a
4368 new virtual function table if we're supposed to include vptrs in
4369 all classes that need them. */
4371 {
4372 /* We build this decl with vtbl_ptr_type_node, which is a
4373 `vtable_entry_type*'. It might seem more precise to use
4374 `vtable_entry_type (*)[N]' where N is the number of firtual
4375 functions. However, that would require the vtable pointer in
4376 base classes to have a different type than the vtable pointer
4377 in derived classes. We could make that happen, but that
4378 still wouldn't solve all the problems. In particular, the
4379 type-based alias analysis code would decide that assignments
4380 to the base class vtable pointer can't alias assignments to
4381 the derived class vtable pointer, since they have different
4382 types. Thus, in an derived class destructor, where the base
4383 class constructor was inlined, we could generate bad code for
4384 setting up the vtable pointer.
4386 Therefore, we use one type for all vtable pointers. We still
4387 use a type-correct type; it's just doesn't indicate the array
4388 bounds. That's better than using `void*' or some such; it's
4389 cleaner, and it let's the alias analysis code know that these
4390 stores cannot alias stores to void*! */
4391 tree field;
4404 /* This class is non-empty. */
4408 /* If there were any baseclasses, they can't possibly be at
4409 offset zero any more, because that's where the vtable
4410 pointer is. So, converting to a base class is going to
4411 take work. */
4415 }
4418 }
4420 /* Fixup the inline function given by INFO now that the class is
4421 complete. */
4423 static void
4425 tree fn;
4426 {
4428 {
4431 {
4434 }
4435 }
4436 }
4438 /* Fixup the inline methods and friends in TYPE now that TYPE is
4439 complete. */
4441 static void
4443 tree type;
4444 {
4448 {
4453 else
4455 }
4457 /* Do inline member functions. */
4461 /* Do friends. */
4463 method;
4467 }
4469 /* Add OFFSET to all base types of BINFO which is a base in the
4470 hierarchy dominated by T.
4472 OFFSET, which is a type offset, is number of bytes. */
4474 static void
4476 tree binfo;
4477 tree offset;
4478 tree t;
4479 {
4481 tree primary_binfo;
4483 /* Update BINFO's offset. */
4488 offset));
4490 /* Find the primary base class. */
4493 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4494 downwards. */
4496 {
4497 tree base_binfo;
4499 /* On the first time through the loop, do the primary base.
4500 Because the primary base need not be an immediate base, we
4501 must handle the primary base specially. */
4503 {
4508 }
4509 else
4510 {
4512 /* Don't do the primary base twice. */
4515 }
4517 /* Skip virtual bases that aren't our canonical primary base. */
4524 }
4525 }
4527 /* Called via dfs_walk from layout_virtual bases. */
4529 static tree
4531 tree binfo;
4533 {
4534 /* If this is a virtual base, make sure it has the same offset as
4535 the shared copy. If it's a primary base, then we know it's
4536 correct. */
4538 {
4540 tree vbase;
4541 tree offset;
4545 {
4548 }
4549 }
4552 }
4554 /* Set BINFO_OFFSET for all of the virtual bases for T. Update
4555 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4556 empty subobjects of T. */
4558 static void
4560 tree t;
4561 splay_tree offsets;
4562 {
4570 #ifdef STRUCTURE_SIZE_BOUNDARY
4571 /* Packed structures don't need to have minimum size. */
4574 #endif
4576 /* DSIZE is the size of the class without the virtual bases. */
4579 /* Make every class have alignment of at least one. */
4582 /* Go through the virtual bases, allocating space for each virtual
4583 base that is not already a primary base class. These are
4584 allocated in inheritance graph order. */
4586 vbases;
4588 {
4589 tree vbase;
4597 {
4598 /* This virtual base is not a primary base of any class in the
4599 hierarchy, so we have to add space for it. */
4608 /* Add padding so that we can put the virtual base class at an
4609 appropriately aligned offset. */
4613 /* We try to squish empty virtual bases in just like
4614 ordinary empty bases. */
4619 else
4620 {
4621 tree offset;
4628 /* And compute the offset of the virtual base. */
4630 /* Every virtual baseclass takes a least a UNIT, so that
4631 we can take it's address and get something different
4632 for each base. */
4636 }
4638 /* If the first virtual base might have been placed at a
4639 lower address, had we started from CLASSTYPE_SIZE, rather
4640 than TYPE_SIZE, issue a warning. There can be both false
4641 positives and false negatives from this warning in rare
4642 cases; to deal with all the possibilities would probably
4643 require performing both layout algorithms and comparing
4644 the results which is not particularly tractable. */
4646 && first_vbase
4649 desired_align),
4650 bitsize_unit_node),
4652 warning ("offset of virtual base `%T' is not ABI-compliant and may change in a future version of GCC",
4653 basetype);
4655 /* Keep track of the offsets assigned to this virtual base. */
4658 offsets,
4662 }
4663 }
4665 /* Now, go through the TYPE_BINFO hierarchy, setting the
4666 BINFO_OFFSETs correctly for all non-primary copies of the virtual
4667 bases and their direct and indirect bases. The ambiguity checks
4668 in lookup_base depend on the BINFO_OFFSETs being set
4669 correctly. */
4672 /* If we had empty base classes that protruded beyond the end of the
4673 class, we didn't update DSIZE above; we were hoping to overlay
4674 multiple such bases at the same location. */
4678 /* Now, make sure that the total size of the type is a multiple of
4679 its alignment. */
4684 bitsize_unit_node));
4686 /* Check for ambiguous virtual bases. */
4689 vbases;
4691 {
4697 }
4698 }
4700 /* Returns the offset of the byte just past the end of the base class
4701 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4702 only non-virtual bases are included. */
4704 static unsigned HOST_WIDE_INT
4706 tree t;
4708 {
4713 {
4714 tree base_binfo;
4715 tree offset;
4716 tree size;
4727 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4728 allocate some space for it. It cannot have virtual bases,
4729 so TYPE_SIZE_UNIT is fine. */
4731 else
4735 size);
4739 }
4742 }
4744 /* Warn about direct bases of T that are inaccessible because they are
4745 ambiguous. For example:
4747 struct S {};
4748 struct T : public S {};
4749 struct U : public S, public T {};
4751 Here, `(S*) new U' is not allowed because there are two `S'
4752 subobjects of U. */
4754 static void
4756 tree t;
4757 {
4761 {
4767 }
4768 }
4770 /* Compare two INTEGER_CSTs K1 and K2. */
4772 static int
4774 splay_tree_key k1;
4775 splay_tree_key k2;
4776 {
4778 }
4780 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4781 BINFO_OFFSETs for all of the base-classes. Position the vtable
4782 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4784 static void
4786 tree t;
4790 {
4791 tree non_static_data_members;
4792 tree field;
4793 tree vptr;
4794 record_layout_info rli;
4796 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4797 types that appear at that offset. */
4798 splay_tree empty_base_offsets;
4799 /* True if the last field layed out was a bit-field. */
4802 /* Keep track of the first non-static data member. */
4805 /* Start laying out the record. */
4808 /* If possible, we reuse the virtual function table pointer from one
4809 of our base classes. */
4812 /* Create a pointer to our virtual function table. */
4815 /* The vptr is always the first thing in the class. */
4817 {
4820 }
4822 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4828 /* Layout the non-static data members. */
4830 {
4831 tree type;
4832 tree padding;
4834 /* We still pass things that aren't non-static data members to
4835 the back-end, in case it wants to do something with them. */
4837 {
4839 /* If the static data member has incomplete type, keep track
4840 of it so that it can be completed later. (The handling
4841 of pending statics in finish_record_layout is
4842 insufficient; consider:
4844 struct S1;
4845 struct S2 { static S1 s1; };
4847 At this point, finish_record_layout will be called, but
4848 S1 is still incomplete.) */
4852 }
4856 /* If this field is a bit-field whose width is greater than its
4857 type, then there are some special rules for allocating
4858 it. */
4861 {
4862 integer_type_kind itk;
4863 tree integer_type;
4865 /* We must allocate the bits as if suitably aligned for the
4866 longest integer type that fits in this many bits. type
4867 of the field. Then, we are supposed to use the left over
4868 bits as additional padding. */
4874 /* ITK now indicates a type that is too large for the
4875 field. We have to back up by one to find the largest
4876 type that fits. */
4883 }
4884 else
4890 /* If a bit-field does not immediately follow another bit-field,
4891 and yet it starts in the middle of a byte, we have failed to
4892 comply with the ABI. */
4895 && !last_field_was_bitfield
4898 bitsize_unit_node)))
4899 cp_warning_at ("offset of `%D' is not ABI-compliant and may change in a future version of GCC",
4900 field);
4902 /* If we needed additional padding after this field, add it
4903 now. */
4905 {
4906 tree padding_field;
4909 NULL_TREE,
4910 char_type_node);
4916 NULL_TREE,
4918 }
4921 }
4923 /* It might be the case that we grew the class to allocate a
4924 zero-sized base class. That won't be reflected in RLI, yet,
4925 because we are willing to overlay multiple bases at the same
4926 offset. However, now we need to make sure that RLI is big enough
4927 to reflect the entire class. */
4931 {
4934 }
4936 /* We make all structures have at least one element, so that they
4937 have non-zero size. The class may be empty even if it has
4938 basetypes. Therefore, we add the fake field after all the other
4939 fields; if there are already FIELD_DECLs on the list, their
4940 offsets will not be disturbed. */
4942 {
4943 tree padding;
4947 }
4949 /* Let the back-end lay out the type. Note that at this point we
4950 have only included non-virtual base-classes; we will lay out the
4951 virtual base classes later. So, the TYPE_SIZE/TYPE_ALIGN after
4952 this call are not necessarily correct; they are just the size and
4953 alignment when no virtual base clases are used. */
4956 /* Delete all zero-width bit-fields from the list of fields. Now
4957 that the type is laid out they are no longer important. */
4960 /* Remember the size and alignment of the class before adding
4961 the virtual bases. */
4963 {
4966 }
4967 /* If this is a POD, we can't reuse its tail padding. */
4969 {
4972 }
4973 else
4974 {
4977 }
4982 /* Set the TYPE_DECL for this type to contain the right
4983 value for DECL_OFFSET, so that we can use it as part
4984 of a COMPONENT_REF for multiple inheritance. */
4987 /* Now fix up any virtual base class types that we left lying
4988 around. We must get these done before we try to lay out the
4989 virtual function table. As a side-effect, this will remove the
4990 base subobject fields. */
4993 /* Warn about direct bases that can't be talked about due to
4994 ambiguity. */
4997 /* Clean up. */
4999 }
5001 /* Create a RECORD_TYPE or UNION_TYPE node for a C struct or union declaration
5002 (or C++ class declaration).
5004 For C++, we must handle the building of derived classes.
5005 Also, C++ allows static class members. The way that this is
5006 handled is to keep the field name where it is (as the DECL_NAME
5007 of the field), and place the overloaded decl in the bit position
5008 of the field. layout_record and layout_union will know about this.
5010 More C++ hair: inline functions have text in their
5011 DECL_PENDING_INLINE_INFO nodes which must somehow be parsed into
5012 meaningful tree structure. After the struct has been laid out, set
5013 things up so that this can happen.
5015 And still more: virtual functions. In the case of single inheritance,
5016 when a new virtual function is seen which redefines a virtual function
5017 from the base class, the new virtual function is placed into
5018 the virtual function table at exactly the same address that
5019 it had in the base class. When this is extended to multiple
5020 inheritance, the same thing happens, except that multiple virtual
5021 function tables must be maintained. The first virtual function
5022 table is treated in exactly the same way as in the case of single
5023 inheritance. Additional virtual function tables have different
5024 DELTAs, which tell how to adjust `this' to point to the right thing.
5026 ATTRIBUTES is the set of decl attributes to be applied, if any. */
5028 void
5030 tree t;
5031 {
5032 tree x;
5034 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5037 tree vfield;
5041 {
5044 else
5048 }
5050 /* If this type was previously laid out as a forward reference,
5051 make sure we lay it out again. */
5060 /* Do end-of-class semantic processing: checking the validity of the
5061 bases and members and add implicitly generated methods. */
5064 /* Layout the class itself. */
5067 /* Make sure that we get our own copy of the vfield FIELD_DECL. */
5070 {
5076 /* The vtable better be at the start. */
5085 }
5086 else
5091 /* If we created a new vtbl pointer for this class, add it to the
5092 list. */
5097 /* If necessary, create the primary vtable for this class. */
5099 {
5100 /* We must enter these virtuals into the table. */
5104 /* Here we know enough to change the type of our virtual
5105 function table, but we will wait until later this function. */
5108 /* If this type has basetypes with constructors, then those
5109 constructors might clobber the virtual function table. But
5110 they don't if the derived class shares the exact vtable of the base
5111 class. */
5113 }
5114 /* If we didn't need a new vtable, see if we should copy one from
5115 the base. */
5117 {
5120 /* If this class uses a different vtable than its primary base
5121 then when we will need to initialize our vptr after the base
5122 class constructor runs. */
5125 }
5128 {
5137 /* Add entries for virtual functions introduced by this class. */
5139 }
5143 /* Complete the rtl for any static member objects of the type we're
5144 working on. */
5150 /* Done with FIELDS...now decide whether to sort these for
5151 faster lookups later.
5153 The C front-end only does this when n_fields > 15. We use
5154 a smaller number because most searches fail (succeeding
5155 ultimately as the search bores through the inheritance
5156 hierarchy), and we want this failure to occur quickly. */
5160 {
5168 }
5171 {
5176 /* Mark the fact that constructor for T could affect anybody
5177 inheriting from T who wants to initialize vtables for
5178 VFIELDS's type. */
5181 }
5183 /* Make the rtl for any new vtables we have created, and unmark
5184 the base types we marked. */
5187 /* Build the VTT for T. */
5203 /* Finish debugging output for this type. */
5205 }
5207 /* When T was built up, the member declarations were added in reverse
5208 order. Rearrange them to declaration order. */
5210 void
5212 tree t;
5213 {
5214 tree next;
5215 tree prev;
5216 tree x;
5218 /* The TYPE_FIELDS, TYPE_METHODS, and CLASSTYPE_TAGS are all in
5219 reverse order. Put them in declaration order now. */
5223 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5224 reverse order, so we can't just use nreverse. */
5229 {
5233 }
5235 {
5239 }
5240 }
5242 tree
5245 {
5249 /* Now that we've got all the field declarations, reverse everything
5250 as necessary. */
5255 /* Nadger the current location so that diagnostics point to the start of
5256 the struct, not the end. */
5261 {
5264 }
5265 else
5275 else
5282 }
5283 \f
5284 /* Return the dynamic type of INSTANCE, if known.
5285 Used to determine whether the virtual function table is needed
5286 or not.
5288 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5289 of our knowledge of its type. *NONNULL should be initialized
5290 before this function is called. */
5292 static tree
5294 tree instance;
5297 {
5299 {
5303 else
5308 /* This is a call to a constructor, hence it's never zero. */
5310 {
5314 }
5318 /* This is a call to a constructor, hence it's never zero. */
5320 {
5324 }
5335 /* Propagate nonnull. */
5355 {
5359 }
5360 /* fall through... */
5365 {
5369 }
5371 {
5375 /* if we're in a ctor or dtor, we know our type. */
5379 {
5383 }
5384 }
5386 {
5387 /* Reference variables should be references to objects. */
5395 }
5400 }
5401 }
5403 /* Return non-zero if the dynamic type of INSTANCE is known, and
5404 equivalent to the static type. We also handle the case where
5405 INSTANCE is really a pointer. Return negative if this is a
5406 ctor/dtor. There the dynamic type is known, but this might not be
5407 the most derived base of the original object, and hence virtual
5408 bases may not be layed out according to this type.
5410 Used to determine whether the virtual function table is needed
5411 or not.
5413 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5414 of our knowledge of its type. *NONNULL should be initialized
5415 before this function is called. */
5417 int
5419 tree instance;
5421 {
5433 }
5435 \f
5436 void
5438 {
5441 current_class_stack
5458 }
5460 /* Set current scope to NAME. CODE tells us if this is a
5461 STRUCT, UNION, or ENUM environment.
5463 NAME may end up being NULL_TREE if this is an anonymous or
5464 late-bound struct (as in "struct { ... } foo;") */
5466 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE to
5467 appropriate values, found by looking up the type definition of
5468 NAME (as a CODE).
5470 If MODIFY is 1, we set IDENTIFIER_CLASS_VALUE's of names
5471 which can be seen locally to the class. They are shadowed by
5472 any subsequent local declaration (including parameter names).
5474 If MODIFY is 2, we set IDENTIFIER_CLASS_VALUE's of names
5475 which have static meaning (i.e., static members, static
5476 member functions, enum declarations, etc).
5478 If MODIFY is 3, we set IDENTIFIER_CLASS_VALUE of names
5479 which can be seen locally to the class (as in 1), but
5480 know that we are doing this for declaration purposes
5481 (i.e. friend foo::bar (int)).
5483 So that we may avoid calls to lookup_name, we cache the _TYPE
5484 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5486 For multiple inheritance, we perform a two-pass depth-first search
5487 of the type lattice. The first pass performs a pre-order search,
5488 marking types after the type has had its fields installed in
5489 the appropriate IDENTIFIER_CLASS_VALUE slot. The second pass merely
5490 unmarks the marked types. If a field or member function name
5491 appears in an ambiguous way, the IDENTIFIER_CLASS_VALUE of
5492 that name becomes `error_mark_node'. */
5494 void
5496 tree type;
5498 {
5501 /* Make sure there is enough room for the new entry on the stack. */
5503 {
5505 current_class_stack
5507 current_class_stack_size
5509 }
5511 /* Insert a new entry on the class stack. */
5516 current_class_depth++;
5518 /* Now set up the new type. */
5524 /* By default, things in classes are private, while things in
5525 structures or unions are public. */
5527 ? access_private_node
5534 {
5535 /* Forcibly remove any old class remnants. */
5537 }
5539 /* If we're about to enter a nested class, clear
5540 IDENTIFIER_CLASS_VALUE for the enclosing classes. */
5547 {
5550 else
5551 {
5552 tree item;
5554 /* We are re-entering the same class we just left, so we
5555 don't have to search the whole inheritance matrix to find
5556 all the decls to bind again. Instead, we install the
5557 cached class_shadowed list, and walk through it binding
5558 names and setting up IDENTIFIER_TYPE_VALUEs. */
5561 {
5568 }
5570 }
5573 }
5574 }
5576 /* When we exit a toplevel class scope, we save the
5577 IDENTIFIER_CLASS_VALUEs so that we can restore them quickly if we
5578 reenter the class. Here, we've entered some other class, so we
5579 must invalidate our cache. */
5581 void
5583 {
5584 tree t;
5586 /* The IDENTIFIER_CLASS_VALUEs are no longer valid. */
5592 }
5594 /* Get out of the current class scope. If we were in a class scope
5595 previously, that is the one popped to. */
5597 void
5599 {
5603 current_class_depth--;
5609 }
5611 /* Returns 1 if current_class_type is either T or a nested type of T.
5612 We start looking from 1 because entry 0 is from global scope, and has
5613 no type. */
5615 int
5617 tree t;
5618 {
5626 }
5628 /* If either current_class_type or one of its enclosing classes are derived
5629 from T, return the appropriate type. Used to determine how we found
5630 something via unqualified lookup. */
5632 tree
5634 tree t;
5635 {
5646 }
5648 /* When entering a class scope, all enclosing class scopes' names with
5649 static meaning (static variables, static functions, types and enumerators)
5650 have to be visible. This recursive function calls pushclass for all
5651 enclosing class contexts until global or a local scope is reached.
5652 TYPE is the enclosed class and MODIFY is equivalent with the pushclass
5653 formal of the same name. */
5655 void
5657 tree type;
5659 {
5660 tree context;
5662 /* A namespace might be passed in error cases, like A::B:C. */
5676 }
5678 /* Undoes a push_nested_class call. MODIFY is passed on to popclass. */
5680 void
5682 {
5688 }
5690 /* Returns the number of extern "LANG" blocks we are nested within. */
5692 int
5694 {
5696 }
5698 /* Set global variables CURRENT_LANG_NAME to appropriate value
5699 so that behavior of name-mangling machinery is correct. */
5701 void
5703 tree name;
5704 {
5708 {
5710 }
5712 {
5714 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5715 (See record_builtin_java_type in decl.c.) However, that causes
5716 incorrect debug entries if these types are actually used.
5717 So we re-enable debug output after extern "Java". */
5726 }
5728 {
5730 }
5731 else
5733 }
5735 /* Get out of the current language scope. */
5737 void
5739 {
5742 }
5743 \f
5744 /* Type instantiation routines. */
5746 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5747 matches the TARGET_TYPE. If there is no satisfactory match, return
5748 error_mark_node, and issue an error message if COMPLAIN is
5749 non-zero. Permit pointers to member function if PTRMEM is non-zero.
5750 If TEMPLATE_ONLY, the name of the overloaded function
5751 was a template-id, and EXPLICIT_TARGS are the explicitly provided
5752 template arguments. */
5754 static tree
5756 overload,
5757 complain,
5758 ptrmem,
5759 template_only,
5760 explicit_targs)
5761 tree target_type;
5762 tree overload;
5766 tree explicit_targs;
5767 {
5768 /* Here's what the standard says:
5770 [over.over]
5772 If the name is a function template, template argument deduction
5773 is done, and if the argument deduction succeeds, the deduced
5774 arguments are used to generate a single template function, which
5775 is added to the set of overloaded functions considered.
5777 Non-member functions and static member functions match targets of
5778 type "pointer-to-function" or "reference-to-function." Nonstatic
5779 member functions match targets of type "pointer-to-member
5780 function;" the function type of the pointer to member is used to
5781 select the member function from the set of overloaded member
5782 functions. If a nonstatic member function is selected, the
5783 reference to the overloaded function name is required to have the
5784 form of a pointer to member as described in 5.3.1.
5786 If more than one function is selected, any template functions in
5787 the set are eliminated if the set also contains a non-template
5788 function, and any given template function is eliminated if the
5789 set contains a second template function that is more specialized
5790 than the first according to the partial ordering rules 14.5.5.2.
5791 After such eliminations, if any, there shall remain exactly one
5792 selected function. */
5796 /* We store the matches in a TREE_LIST rooted here. The functions
5797 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5798 interoperability with most_specialized_instantiation. */
5800 tree fn;
5802 /* By the time we get here, we should be seeing only real
5803 pointer-to-member types, not the internal POINTER_TYPE to
5804 METHOD_TYPE representation. */
5812 /* Check that the TARGET_TYPE is reasonable. */
5816 /* This is OK, too. */
5819 {
5820 /* This is OK, too. This comes from a conversion to reference
5821 type. */
5824 }
5825 else
5826 {
5832 }
5834 /* If we can find a non-template function that matches, we can just
5835 use it. There's no point in generating template instantiations
5836 if we're just going to throw them out anyhow. But, of course, we
5837 can only do this when we don't *need* a template function. */
5839 {
5840 tree fns;
5843 {
5845 tree fntype;
5848 /* We're not looking for templates just yet. */
5853 /* We're looking for a non-static member, and this isn't
5854 one, or vice versa. */
5857 /* See if there's a match. */
5866 }
5867 }
5869 /* Now, if we've already got a match (or matches), there's no need
5870 to proceed to the template functions. But, if we don't have a
5871 match we need to look at them, too. */
5873 {
5874 tree target_fn_type;
5875 tree target_arg_types;
5876 tree target_ret_type;
5877 tree fns;
5880 target_fn_type
5882 else
5887 /* Never do unification on the 'this' parameter. */
5892 {
5894 tree instantiation;
5895 tree instantiation_type;
5896 tree targs;
5899 /* We're only looking for templates. */
5904 /* We're not looking for a non-static member, and this is
5905 one, or vice versa. */
5908 /* Try to do argument deduction. */
5913 /* Argument deduction failed. */
5916 /* Instantiate the template. */
5919 /* Instantiation failed. */
5922 /* See if there's a match. */
5925 instantiation_type =
5931 }
5933 /* Now, remove all but the most specialized of the matches. */
5935 {
5940 }
5941 }
5943 /* Now we should have exactly one function in MATCHES. */
5945 {
5946 /* There were *no* matches. */
5948 {
5951 target_type);
5953 /* print_candidates expects a chain with the functions in
5954 TREE_VALUE slots, so we cons one up here (we're losing anyway,
5955 so why be clever?). */
5958 matches);
5961 }
5963 }
5965 {
5966 /* There were too many matches. */
5969 {
5970 tree match;
5974 target_type);
5976 /* Since print_candidates expects the functions in the
5977 TREE_VALUE slot, we flip them here. */
5982 }
5985 }
5987 /* Good, exactly one match. Now, convert it to the correct type. */
5992 {
6000 {
6003 }
6004 }
6009 else
6010 {
6011 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
6012 will mark the function as addressed, but here we must do it
6013 explicitly. */
6017 }
6018 }
6020 /* This function will instantiate the type of the expression given in
6021 RHS to match the type of LHSTYPE. If errors exist, then return
6022 error_mark_node. FLAGS is a bit mask. If ITF_COMPLAIN is set, then
6023 we complain on errors. If we are not complaining, never modify rhs,
6024 as overload resolution wants to try many possible instantiations, in
6025 the hope that at least one will work.
6027 For non-recursive calls, LHSTYPE should be a function, pointer to
6028 function, or a pointer to member function. */
6030 tree
6033 tsubst_flags_t flags;
6034 {
6043 {
6047 }
6050 {
6057 }
6062 /* We don't overwrite rhs if it is an overloaded function.
6063 Copying it would destroy the tree link. */
6067 /* This should really only be used when attempting to distinguish
6068 what sort of a pointer to function we have. For now, any
6069 arithmetic operation which is not supported on pointers
6070 is rejected as an error. */
6073 {
6084 {
6085 tree new_rhs;
6095 }
6111 /* This can happen if we are forming a pointer-to-member for a
6112 member template. */
6115 /* Fall through. */
6118 {
6122 return
6124 fns,
6125 complain,
6126 allow_ptrmem,
6128 args);
6129 }
6132 return
6134 rhs,
6135 complain,
6136 allow_ptrmem,
6141 /* Now we should have a baselink. */
6147 /* This is too hard for now. */
6221 {
6225 }
6248 {
6253 }
6264 }
6265 }
6266 \f
6267 /* Return the name of the virtual function pointer field
6268 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6269 this may have to look back through base types to find the
6270 ultimate field name. (For single inheritance, these could
6271 all be the same name. Who knows for multiple inheritance). */
6273 static tree
6275 tree type;
6276 {
6291 }
6293 void
6295 {
6296 #ifdef GATHER_STATISTICS
6302 {
6307 }
6308 #endif
6309 }
6311 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6312 according to [class]:
6313 The class-name is also inserted
6314 into the scope of the class itself. For purposes of access checking,
6315 the inserted class name is treated as if it were a public member name. */
6317 void
6319 {
6322 tree saved_cas;
6335 }
6337 /* Returns 1 if TYPE contains only padding bytes. */
6339 int
6341 tree type;
6342 {
6350 }
6352 /* Find the enclosing class of the given NODE. NODE can be a *_DECL or
6353 a *_TYPE node. NODE can also be a local class. */
6355 tree
6357 tree type;
6358 {
6362 {
6364 {
6377 }
6378 }
6380 }
6382 /* Return 1 if TYPE or one of its enclosing classes is derived from BASE. */
6384 int
6387 {
6389 {
6394 }
6396 }
6398 /* Note that NAME was looked up while the current class was being
6399 defined and that the result of that lookup was DECL. */
6401 void
6403 tree name;
6404 tree decl;
6405 {
6406 splay_tree names_used;
6408 /* If we're not defining a class, there's nothing to do. */
6412 /* If there's already a binding for this NAME, then we don't have
6413 anything to worry about. */
6425 }
6427 /* Note that NAME was declared (as DECL) in the current class. Check
6428 to see that the declaration is valid. */
6430 void
6432 tree name;
6433 tree decl;
6434 {
6435 splay_tree names_used;
6436 splay_tree_node n;
6438 /* Look to see if we ever used this name. */
6439 names_used
6446 {
6447 /* [basic.scope.class]
6449 A name N used in a class S shall refer to the same declaration
6450 in its context and when re-evaluated in the completed scope of
6451 S. */
6456 }
6457 }
6459 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6460 Secondary vtables are merged with primary vtables; this function
6461 will return the VAR_DECL for the primary vtable. */
6463 tree
6465 tree binfo;
6466 {
6467 tree decl;
6471 {
6475 }
6479 }
6481 /* Called from get_primary_binfo via dfs_walk. DATA is a TREE_LIST
6482 who's TREE_PURPOSE is the TYPE of the required primary base and
6483 who's TREE_VALUE is a list of candidate binfos that we fill in. */
6485 static tree
6487 tree binfo;
6489 {
6495 /* This is the right type of binfo, but it might be an unshared
6496 instance, and the shared instance is later in the dfs walk. We
6497 must keep looking. */
6501 }
6503 /* Returns the unshared binfo for the primary base of BINFO. Note
6504 that in a complex hierarchy the resulting BINFO may not actually
6505 *be* primary. In particular if the resulting BINFO is a virtual
6506 base, and it occurs elsewhere in the hierarchy, then this
6507 occurrence may not actually be a primary base in the complete
6508 object. Check BINFO_PRIMARY_P to be sure. */
6510 tree
6512 tree binfo;
6513 {
6514 tree primary_base;
6516 tree virtuals;
6522 /* A non-virtual primary base is always a direct base, and easy to
6523 find. */
6525 {
6528 /* Scan the direct basetypes until we find a base with the same
6529 type as the primary base. */
6531 {
6537 }
6539 /* We should always find the primary base. */
6541 }
6543 /* For a primary virtual base, we have to scan the entire hierarchy
6544 rooted at BINFO; the virtual base could be an indirect virtual
6545 base. There could be more than one instance of the primary base
6546 in the hierarchy, and if one is the canonical binfo we want that
6547 one. If it exists, it should be the first one we find, but as a
6548 consistency check we find them all and make sure. */
6553 /* We must have found at least one instance. */
6557 {
6558 /* We found more than one instance of the base. We must make
6559 sure that, if one is the canonical one, it is the first one
6560 we found. As the chain is in reverse dfs order, that means
6561 the last on the list. */
6562 tree complete_binfo;
6563 tree canonical;
6573 {
6577 {
6578 /* This is the unshared instance. Make sure it was the
6579 first one found. */
6582 }
6583 }
6584 }
6585 else
6588 }
6590 /* If INDENTED_P is zero, indent to INDENT. Return non-zero. */
6592 static int
6597 {
6601 }
6603 /* Dump the offsets of all the bases rooted at BINFO (in the hierarchy
6604 dominated by T) to stderr. INDENT should be zero when called from
6605 the top level; it is incremented recursively. */
6607 static void
6611 tree t;
6612 tree binfo;
6614 {
6629 {
6635 else
6637 }
6642 {
6646 TFF_PLAIN_IDENTIFIER),
6648 }
6650 {
6653 }
6658 {
6662 {
6666 TFF_PLAIN_IDENTIFIER));
6667 }
6669 {
6673 TFF_PLAIN_IDENTIFIER));
6674 }
6676 {
6680 TFF_PLAIN_IDENTIFIER));
6681 }
6683 {
6687 TFF_PLAIN_IDENTIFIER));
6688 }
6692 }
6699 }
6701 /* Dump the BINFO hierarchy for T. */
6703 static void
6705 tree t;
6706 {
6720 }
6722 static void
6725 tree decl;
6726 {
6727 tree inits;
6729 HOST_WIDE_INT elt;
6737 TFF_PLAIN_IDENTIFIER));
6744 }
6746 static void
6748 tree t;
6749 tree binfo;
6750 tree vtable;
6751 {
6759 {
6766 {
6770 }
6774 }
6777 }
6779 static void
6781 tree t;
6782 tree vtt;
6783 {
6791 {
6796 }
6799 }
6801 /* Virtual function table initialization. */
6803 /* Create all the necessary vtables for T and its base classes. */
6805 static void
6807 tree t;
6808 {
6809 tree list;
6810 tree vbase;
6813 /* We lay out the primary and secondary vtables in one contiguous
6814 vtable. The primary vtable is first, followed by the non-virtual
6815 secondary vtables in inheritance graph order. */
6820 /* Then come the virtual bases, also in inheritance graph order. */
6822 {
6823 tree real_base;
6828 /* Although we walk in inheritance order, that might not get the
6829 canonical base. */
6834 }
6836 /* Fill in BINFO_VPTR_FIELD in the immediate binfos for our virtual
6837 base classes, for the benefit of the debugging backends. */
6839 {
6842 {
6845 }
6846 }
6850 }
6852 /* Initialize the vtable for BINFO with the INITS. */
6854 static void
6856 tree binfo;
6857 tree inits;
6858 {
6859 tree decl;
6865 }
6867 /* Initialize DECL (a declaration for a namespace-scope array) with
6868 the INITS. */
6870 static void
6872 tree decl;
6873 tree inits;
6874 {
6875 tree context;
6882 }
6884 /* Build the VTT (virtual table table) for T.
6885 A class requires a VTT if it has virtual bases.
6887 This holds
6888 1 - primary virtual pointer for complete object T
6889 2 - secondary VTTs for each direct non-virtual base of T which requires a
6890 VTT
6891 3 - secondary virtual pointers for each direct or indirect base of T which
6892 has virtual bases or is reachable via a virtual path from T.
6893 4 - secondary VTTs for each direct or indirect virtual base of T.
6895 Secondary VTTs look like complete object VTTs without part 4. */
6897 static void
6899 tree t;
6900 {
6901 tree inits;
6902 tree type;
6903 tree vtt;
6904 tree index;
6906 /* Build up the initializers for the VTT. */
6911 /* If we didn't need a VTT, we're done. */
6915 /* Figure out the type of the VTT. */
6919 /* Now, build the VTT object itself. */
6925 }
6927 /* The type corresponding to BASE_BINFO is a base of the type of BINFO, but
6928 from within some hierarchy which is inherited from the type of BINFO.
6929 Return BASE_BINFO's equivalent binfo from the hierarchy dominated by
6930 BINFO. */
6932 static tree
6934 tree base_binfo;
6935 tree binfo;
6936 {
6937 tree derived;
6952 }
6954 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6955 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6956 and CHAIN the vtable pointer for this binfo after construction is
6957 complete. VALUE can also be another BINFO, in which case we recurse. */
6959 static tree
6961 tree binfo;
6962 {
6963 tree vt;
6966 {
6972 else
6974 }
6977 }
6979 /* Recursively build the VTT-initializer for BINFO (which is in the
6980 hierarchy dominated by T). INITS points to the end of the initializer
6981 list to date. INDEX is the VTT index where the next element will be
6982 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6983 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
6984 for virtual bases of T. When it is not so, we build the constructor
6985 vtables for the BINFO-in-T variant. */
6989 tree binfo;
6990 tree t;
6993 {
6995 tree b;
6996 tree init;
6997 tree secondary_vptrs;
7000 /* We only need VTTs for subobjects with virtual bases. */
7004 /* We need to use a construction vtable if this is not the primary
7005 VTT. */
7007 {
7010 /* Record the offset in the VTT where this sub-VTT can be found. */
7012 }
7014 /* Add the address of the primary vtable for the complete object. */
7019 {
7022 }
7025 /* Recursively add the secondary VTTs for non-virtual bases. */
7027 {
7032 }
7034 /* Add secondary virtual pointers for all subobjects of BINFO with
7035 either virtual bases or reachable along a virtual path, except
7036 subobjects that are non-virtual primary bases. */
7043 dfs_build_secondary_vptr_vtt_inits,
7044 NULL,
7045 dfs_ctor_vtable_bases_queue_p,
7046 secondary_vptrs);
7049 secondary_vptrs);
7053 /* The secondary vptrs come back in reverse order. After we reverse
7054 them, and add the INITS, the last init will be the first element
7055 of the chain. */
7058 {
7062 }
7064 /* Add the secondary VTTs for virtual bases. */
7067 {
7068 tree vbase;
7075 }
7078 {
7084 dfs_ctor_vtable_bases_queue_p,
7085 data);
7086 }
7089 }
7091 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo
7092 for the base in most derived. DATA is a TREE_LIST who's
7093 TREE_CHAIN is the type of the base being
7094 constructed whilst this secondary vptr is live. The TREE_UNSIGNED
7095 flag of DATA indicates that this is a constructor vtable. The
7096 TREE_TOP_LEVEL flag indicates that this is the primary VTT. */
7098 static tree
7100 tree binfo;
7102 {
7103 tree l;
7104 tree t;
7105 tree init;
7106 tree index;
7115 /* We don't care about bases that don't have vtables. */
7119 /* We're only interested in proper subobjects of T. */
7123 /* We're not interested in non-virtual primary bases. */
7127 /* If BINFO has virtual bases or is reachable via a virtual path
7128 from T, it'll have a secondary vptr. */
7133 /* Record the index where this secondary vptr can be found. */
7136 {
7139 }
7143 /* Add the initializer for the secondary vptr itself. */
7145 {
7146 /* It's a primary virtual base, and this is not the construction
7147 vtable. Find the base this is primary of in the inheritance graph,
7148 and use that base's vtable now. */
7151 }
7156 }
7158 /* dfs_walk_real predicate for building vtables. DATA is a TREE_LIST,
7159 VTT_MARKED_BINFO_P indicates whether marked or unmarked bases
7160 should be walked. TREE_PURPOSE is the TREE_TYPE that dominates the
7161 hierarchy. */
7163 static tree
7165 tree binfo;
7167 {
7169 /* Get the shared version. */
7175 }
7177 /* Called from build_vtt_inits via dfs_walk. After building constructor
7178 vtables and generating the sub-vtt from them, we need to restore the
7179 BINFO_VTABLES that were scribbled on. DATA is a TREE_LIST whose
7180 TREE_VALUE is the TREE_TYPE of the base whose sub vtt was generated. */
7182 static tree
7184 tree binfo;
7186 {
7189 /* We don't care about bases that don't have vtables. */
7193 /* If we scribbled the construction vtable vptr into BINFO, clear it
7194 out now. */
7202 }
7204 /* Build the construction vtable group for BINFO which is in the
7205 hierarchy dominated by T. */
7207 static void
7209 tree binfo;
7210 tree t;
7211 {
7212 tree list;
7213 tree type;
7214 tree vtbl;
7215 tree inits;
7216 tree id;
7217 tree vbase;
7219 /* See if we've already created this construction vtable group. */
7225 /* Build a version of VTBL (with the wrong type) for use in
7226 constructing the addresses of secondary vtables in the
7227 construction vtable group. */
7233 /* Add the vtables for each of our virtual bases using the vbase in T
7234 binfo. */
7236 vbase;
7238 {
7239 tree b;
7240 tree orig_base;
7248 }
7251 /* Figure out the type of the construction vtable. */
7256 /* Initialize the construction vtable. */
7260 }
7262 /* Add the vtbl initializers for BINFO (and its bases other than
7263 non-virtual primaries) to the list of INITS. BINFO is in the
7264 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7265 the constructor the vtbl inits should be accumulated for. (If this
7266 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7267 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7268 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7269 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7270 but are not necessarily the same in terms of layout. */
7272 static void
7274 tree binfo;
7275 tree orig_binfo;
7276 tree rtti_binfo;
7277 tree t;
7278 tree inits;
7279 {
7287 /* If it doesn't have a vptr, we don't do anything. */
7291 /* If we're building a construction vtable, we're not interested in
7292 subobjects that don't require construction vtables. */
7298 /* Build the initializers for the BINFO-in-T vtable. */
7304 /* Walk the BINFO and its bases. We walk in preorder so that as we
7305 initialize each vtable we can figure out at what offset the
7306 secondary vtable lies from the primary vtable. We can't use
7307 dfs_walk here because we need to iterate through bases of BINFO
7308 and RTTI_BINFO simultaneously. */
7310 {
7313 /* Skip virtual bases. */
7319 inits);
7320 }
7321 }
7323 /* Called from accumulate_vtbl_inits. Returns the initializers for
7324 the BINFO vtable. */
7326 static tree
7328 tree binfo;
7329 tree orig_binfo;
7330 tree rtti_binfo;
7331 tree t;
7332 tree l;
7333 {
7340 {
7341 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7342 primary virtual base. If it is not the same primary in
7343 the hierarchy of T, we'll need to generate a ctor vtable
7344 for it, to place at its location in T. If it is the same
7345 primary, we still need a VTT entry for the vtable, but it
7346 should point to the ctor vtable for the base it is a
7347 primary for within the sub-hierarchy of RTTI_BINFO.
7349 There are three possible cases:
7351 1) We are in the same place.
7352 2) We are a primary base within a lost primary virtual base of
7353 RTTI_BINFO.
7354 3) We are primary to something not a base of RTTI_BINFO. */
7359 /* First, look through the bases we are primary to for RTTI_BINFO
7360 or a virtual base. */
7362 {
7366 }
7367 /* If we run out of primary links, keep looking down our
7368 inheritance chain; we might be an indirect primary. */
7374 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7375 base B and it is a base of RTTI_BINFO, this is case 2. In
7376 either case, we share our vtable with LAST, i.e. the
7377 derived-most base within B of which we are a primary. */
7381 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7382 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7383 binfo_ctor_vtable after everything's been set up. */
7386 /* Otherwise, this is case 3 and we get our own. */
7387 }
7392 {
7393 tree index;
7396 /* Compute the initializer for this vtable. */
7400 /* Figure out the position to which the VPTR should point. */
7403 vtbl_ptr_type_node,
7404 vtbl);
7411 index);
7414 }
7417 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7418 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7419 straighten this out. */
7423 else
7424 /* For an ordinary vtable, set BINFO_VTABLE. */
7428 }
7430 /* Construct the initializer for BINFO's virtual function table. BINFO
7431 is part of the hierarchy dominated by T. If we're building a
7432 construction vtable, the ORIG_BINFO is the binfo we should use to
7433 find the actual function pointers to put in the vtable - but they
7434 can be overridden on the path to most-derived in the graph that
7435 ORIG_BINFO belongs. Otherwise,
7436 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7437 BINFO that should be indicated by the RTTI information in the
7438 vtable; it will be a base class of T, rather than T itself, if we
7439 are building a construction vtable.
7441 The value returned is a TREE_LIST suitable for wrapping in a
7442 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7443 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7444 number of non-function entries in the vtable.
7446 It might seem that this function should never be called with a
7447 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7448 base is always subsumed by a derived class vtable. However, when
7449 we are building construction vtables, we do build vtables for
7450 primary bases; we need these while the primary base is being
7451 constructed. */
7453 static tree
7455 tree binfo;
7456 tree orig_binfo;
7457 tree t;
7458 tree rtti_binfo;
7460 {
7462 tree vfun_inits;
7463 tree vbase;
7464 vtbl_init_data vid;
7466 /* Initialize VID. */
7474 /* The first vbase or vcall offset is at index -3 in the vtable. */
7477 /* Add entries to the vtable for RTTI. */
7480 /* Create an array for keeping track of the functions we've
7481 processed. When we see multiple functions with the same
7482 signature, we share the vcall offsets. */
7484 /* Add the vcall and vbase offset entries. */
7486 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7487 build_vbase_offset_vtbl_entries. */
7489 vbase;
7493 /* If the target requires padding between data entries, add that now. */
7495 {
7499 {
7506 }
7507 }
7512 /* Go through all the ordinary virtual functions, building up
7513 initializers. */
7516 {
7517 tree delta;
7518 tree vcall_index;
7519 tree fn;
7520 tree pfn;
7525 /* If the only definition of this function signature along our
7526 primary base chain is from a lost primary, this vtable slot will
7527 never be used, so just zero it out. This is important to avoid
7528 requiring extra thunks which cannot be generated with the function.
7530 We first check this in update_vtable_entry_for_fn, so we handle
7531 restored primary bases properly; we also need to do it here so we
7532 zero out unused slots in ctor vtables, rather than filling themff
7533 with erroneous values (though harmless, apart from relocation
7534 costs). */
7536 {
7537 /* We found a defn before a lost primary; go ahead as normal. */
7541 /* The nearest definition is from a lost primary; clear the
7542 slot. */
7544 {
7547 }
7548 }
7551 {
7552 /* Pull the offset for `this', and the function to call, out of
7553 the list. */
7557 {
7560 }
7561 else
7567 /* You can't call an abstract virtual function; it's abstract.
7568 So, we replace these functions with __pure_virtual. */
7572 /* Take the address of the function, considering it to be of an
7573 appropriate generic type. */
7575 /* The address of a function can't change. */
7578 /* Enter it in the vtable. */
7580 }
7582 /* And add it to the chain of initializers. */
7584 {
7589 else
7591 {
7598 }
7599 }
7600 else
7602 }
7604 /* The initializers for virtual functions were built up in reverse
7605 order; straighten them out now. */
7608 /* The negative offset initializers are also in reverse order. */
7611 /* Chain the two together. */
7613 }
7615 /* Adds to vid->inits the initializers for the vbase and vcall
7616 offsets in BINFO, which is in the hierarchy dominated by T. */
7618 static void
7620 tree binfo;
7622 {
7623 tree b;
7625 /* If this is a derived class, we must first create entries
7626 corresponding to the primary base class. */
7631 /* Add the vbase entries for this base. */
7633 /* Add the vcall entries for this base. */
7635 }
7637 /* Returns the initializers for the vbase offset entries in the vtable
7638 for BINFO (which is part of the class hierarchy dominated by T), in
7639 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7640 where the next vbase offset will go. */
7642 static void
7644 tree binfo;
7646 {
7647 tree vbase;
7648 tree t;
7649 tree non_primary_binfo;
7651 /* If there are no virtual baseclasses, then there is nothing to
7652 do. */
7658 /* We might be a primary base class. Go up the inheritance hierarchy
7659 until we find the most derived class of which we are a primary base:
7660 it is the offset of that which we need to use. */
7663 {
7664 tree b;
7666 /* If we have reached a virtual base, then it must be a primary
7667 base (possibly multi-level) of vid->binfo, or we wouldn't
7668 have called build_vcall_and_vbase_vtbl_entries for it. But it
7669 might be a lost primary, so just skip down to vid->binfo. */
7671 {
7674 }
7680 }
7682 /* Go through the virtual bases, adding the offsets. */
7684 vbase;
7686 {
7687 tree b;
7688 tree delta;
7693 /* Find the instance of this virtual base in the complete
7694 object. */
7697 /* If we've already got an offset for this virtual base, we
7698 don't need another one. */
7703 /* Figure out where we can find this vbase offset. */
7712 {
7713 tree orig_vbase;
7715 /* Find the instance of this virtual base in the type of BINFO. */
7719 /* The vbase offset had better be the same. */
7723 }
7725 /* The next vbase will come at a more negative offset. */
7729 /* The initializer is the delta from BINFO to this virtual base.
7730 The vbase offsets go in reverse inheritance-graph order, and
7731 we are walking in inheritance graph order so these end up in
7732 the right order. */
7738 vtable_entry_type,
7739 delta)));
7741 }
7742 }
7744 /* Adds the initializers for the vcall offset entries in the vtable
7745 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7746 to VID->INITS. */
7748 static void
7750 tree binfo;
7752 {
7753 /* We only need these entries if this base is a virtual base. */
7757 /* We need a vcall offset for each of the virtual functions in this
7758 vtable. For example:
7760 class A { virtual void f (); };
7761 class B1 : virtual public A { virtual void f (); };
7762 class B2 : virtual public A { virtual void f (); };
7763 class C: public B1, public B2 { virtual void f (); };
7765 A C object has a primary base of B1, which has a primary base of A. A
7766 C also has a secondary base of B2, which no longer has a primary base
7767 of A. So the B2-in-C construction vtable needs a secondary vtable for
7768 A, which will adjust the A* to a B2* to call f. We have no way of
7769 knowing what (or even whether) this offset will be when we define B2,
7770 so we store this "vcall offset" in the A sub-vtable and look it up in
7771 a "virtual thunk" for B2::f.
7773 We need entries for all the functions in our primary vtable and
7774 in our non-virtual bases' secondary vtables. */
7776 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7778 }
7780 /* Build vcall offsets, starting with those for BINFO. */
7782 static void
7784 tree binfo;
7786 {
7788 tree primary_binfo;
7790 /* Don't walk into virtual bases -- except, of course, for the
7791 virtual base for which we are building vcall offsets. Any
7792 primary virtual base will have already had its offsets generated
7793 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7797 /* If BINFO has a primary base, process it first. */
7802 /* Add BINFO itself to the list. */
7805 /* Scan the non-primary bases of BINFO. */
7807 {
7808 tree base_binfo;
7813 }
7814 }
7816 /* Called from build_vcall_offset_vtbl_entries_r. */
7818 static void
7820 tree binfo;
7822 {
7823 tree derived_virtuals;
7824 tree base_virtuals;
7825 tree orig_virtuals;
7826 tree binfo_inits;
7827 /* If BINFO is a primary base, the most derived class which has BINFO as
7828 a primary base; otherwise, just BINFO. */
7829 tree non_primary_binfo;
7833 /* We might be a primary base class. Go up the inheritance hierarchy
7834 until we find the most derived class of which we are a primary base:
7835 it is the BINFO_VIRTUALS there that we need to consider. */
7838 {
7839 tree b;
7841 /* If we have reached a virtual base, then it must be vid->vbase,
7842 because we ignore other virtual bases in
7843 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7844 base (possibly multi-level) of vid->binfo, or we wouldn't
7845 have called build_vcall_and_vbase_vtbl_entries for it. But it
7846 might be a lost primary, so just skip down to vid->binfo. */
7848 {
7853 }
7859 }
7862 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7863 where rtti_binfo is the most derived type. */
7864 non_primary_binfo = get_original_base
7867 /* Make entries for the rest of the virtuals. */
7871 base_virtuals;
7875 {
7876 tree orig_fn;
7877 tree fn;
7878 tree base;
7879 tree base_binfo;
7881 tree vcall_offset;
7883 /* Find the declaration that originally caused this function to
7884 be present in BINFO_TYPE (binfo). */
7887 /* When processing BINFO, we only want to generate vcall slots for
7888 function slots introduced in BINFO. So don't try to generate
7889 one if the function isn't even defined in BINFO. */
7893 /* Find the overriding function. */
7896 /* If there is already an entry for a function with the same
7897 signature as FN, then we do not need a second vcall offset.
7898 Check the list of functions already present in the derived
7899 class vtable. */
7901 {
7902 tree derived_entry;
7906 /* We only use one vcall offset for virtual destructors,
7907 even though there are two virtual table entries. */
7910 {
7915 }
7916 }
7920 /* The FN comes from BASE. So, we must calculate the adjustment from
7921 vid->vbase to BASE. We can just look for BASE in the complete
7922 object because we are converting from a virtual base, so if there
7923 were multiple copies, there would not be a unique final overrider
7924 and vid->derived would be ill-formed. */
7928 /* Compute the vcall offset. */
7929 /* As mentioned above, the vbase we're working on is a primary base of
7930 vid->binfo. But it might be a lost primary, so its BINFO_OFFSET
7931 might be wrong, so we just use the BINFO_OFFSET from vid->binfo. */
7934 vcall_offset);
7936 vcall_offset));
7941 /* Keep track of the vtable index where this vcall offset can be
7942 found. For a construction vtable, we already made this
7943 annotation when we built the original vtable. */
7947 /* The next vcall offset will be found at a more negative
7948 offset. */
7951 /* Keep track of this function. */
7953 }
7954 }
7956 /* Return vtbl initializers for the RTTI entries coresponding to the
7957 BINFO's vtable. The RTTI entries should indicate the object given
7958 by VID->rtti_binfo. */
7960 static void
7962 tree binfo;
7964 {
7965 tree b;
7966 tree t;
7967 tree basetype;
7968 tree offset;
7969 tree decl;
7970 tree init;
7975 /* To find the complete object, we will first convert to our most
7976 primary base, and then add the offset in the vtbl to that value. */
7980 {
7981 tree primary_base;
7986 }
7989 /* The second entry is the address of the typeinfo object. */
7992 else
7995 /* Convert the declaration to a type that can be stored in the
7996 vtable. */
8002 /* Add the offset-to-top entry. It comes earlier in the vtable that
8003 the the typeinfo entry. Convert the offset to look like a
8004 function pointer, so that we can put it in the vtable. */
8009 }
8011 /* Build an entry in the virtual function table. DELTA is the offset
8012 for the `this' pointer. VCALL_INDEX is the vtable index containing
8013 the vcall offset; NULL_TREE if none. ENTRY is the virtual function
8014 table entry itself. It's TREE_TYPE must be VFUNC_PTR_TYPE_NODE,
8015 but it may not actually be a virtual function table pointer. (For
8016 example, it might be the address of the RTTI object, under the new
8017 ABI.) */
8019 static tree
8021 tree delta;
8022 tree vcall_index;
8023 tree entry;
8024 {
8029 {
8034 }
8035 #ifdef GATHER_STATISTICS
8037 #endif
8039 }