| blob | d17ff5ad0b72d8d6e49e25d150fa3500c45654a2 |
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, 2003 Free Software Foundation, Inc.
4 Contributed by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC 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 GCC 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 GCC; 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. */
40 /* The number of nested classes being processed. If we are not in the
41 scope of any class, this is zero. */
45 /* In order to deal with nested classes, we keep a stack of classes.
46 The topmost entry is the innermost class, and is the entry at index
47 CURRENT_CLASS_DEPTH */
50 /* The name of the class. */
51 tree name;
53 /* The _TYPE node for the class. */
54 tree type;
56 /* The access specifier pending for new declarations in the scope of
57 this class. */
58 tree access;
60 /* If were defining TYPE, the names used in this class. */
61 splay_tree names_used;
65 {
66 /* The base for which we're building initializers. */
67 tree binfo;
68 /* The type of the most-derived type. */
69 tree derived;
70 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
71 unless ctor_vtbl_p is true. */
72 tree rtti_binfo;
73 /* The negative-index vtable initializers built up so far. These
74 are in order from least negative index to most negative index. */
75 tree inits;
76 /* The last (i.e., most negative) entry in INITS. */
78 /* The binfo for the virtual base for which we're building
79 vcall offset initializers. */
80 tree vbase;
81 /* The functions in vbase for which we have already provided vcall
82 offsets. */
83 varray_type fns;
84 /* The vtable index of the next vcall or vbase offset. */
85 tree index;
86 /* Nonzero if we are building the initializer for the primary
87 vtable. */
89 /* Nonzero if we are building the initializer for a construction
90 vtable. */
92 /* True when adding vcall offset entries to the vtable. False when
93 merely computing the indices. */
97 /* The type of a function passed to walk_subobject_offsets. */
100 /* The stack itself. This is a dynamically resized array. The
101 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
105 /* An array of all local classes present in this translation unit, in
106 declaration order. */
107 varray_type local_classes;
181 tree);
184 vtbl_init_data *);
204 splay_tree_key k2);
213 /* Macros for dfs walking during vtt construction. See
214 dfs_ctor_vtable_bases_queue_p, dfs_build_secondary_vptr_vtt_inits
215 and dfs_fixup_binfo_vtbls. */
216 #define VTT_TOP_LEVEL_P(NODE) TREE_UNSIGNED (NODE)
217 #define VTT_MARKED_BINFO_P(NODE) TREE_USED (NODE)
219 /* Variables shared between class.c and call.c. */
221 #ifdef GATHER_STATISTICS
230 #endif
232 /* Convert to or from a base subobject. EXPR is an expression of type
233 `A' or `A*', an expression of type `B' or `B*' is returned. To
234 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
235 the B base instance within A. To convert base A to derived B, CODE
236 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
237 In this latter case, A must not be a morally virtual base of B.
238 NONNULL is true if EXPR is known to be non-NULL (this is only
239 needed when EXPR is of pointer type). CV qualifiers are preserved
240 from EXPR. */
242 tree
244 tree expr,
245 tree binfo,
247 {
250 tree probe;
251 tree offset;
252 tree target_type;
254 tree ptr_target_type;
262 {
266 }
279 {
283 }
286 /* This must happen before the call to save_expr. */
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. */
303 tree v_offset;
306 {
307 /* In a base member initializer, we cannot rely on
308 the vtable being set up. We have to use the vtt_parm. */
316 v_offset);
318 }
319 else
327 v_offset);
339 /* Negative fixed_type_p means this is a constructor or destructor;
340 virtual base layout is fixed in in-charge [cd]tors, but not in
341 base [cd]tors. */
345 v_offset,
347 else
349 }
353 target_type = cp_build_qualified_type
363 else
372 expr);
375 }
377 /* Convert OBJECT to the base TYPE. If CHECK_ACCESS is true, an error
378 message is emitted if TYPE is inaccessible. OBJECT is assumed to
379 be non-NULL. */
381 tree
383 {
384 tree binfo;
388 NULL);
393 }
395 /* EXPR is an expression with class type. BASE is a base class (a
396 BINFO) of that class type. Returns EXPR, converted to the BASE
397 type. This function assumes that EXPR is the most derived class;
398 therefore virtual bases can be found at their static offsets. */
400 tree
402 {
403 tree expr_type;
407 {
408 tree pointer_type;
417 }
420 }
422 \f
423 /* Given an object INSTANCE, return an expression which yields the
424 vtable element corresponding to INDEX. There are many special
425 cases for INSTANCE which we take care of here, mainly to avoid
426 creating extra tree nodes when we don't have to. */
428 static tree
430 {
431 tree aref;
434 /* Try to figure out what a reference refers to, and
435 access its virtual function table directly. */
443 {
448 }
459 }
461 tree
463 {
467 }
469 /* Given an object INSTANCE, return an expression which yields a
470 function pointer corresponding to vtable element INDEX. */
472 tree
474 {
477 /* When using function descriptors, the address of the
478 vtable entry is treated as a function pointer. */
484 }
486 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
487 for the given TYPE. */
489 static tree
491 {
493 }
495 /* Return an IDENTIFIER_NODE for the name of the virtual table table
496 for TYPE. */
498 tree
500 {
502 }
504 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
505 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
506 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
508 static tree
510 {
511 tree decl;
514 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
515 now to avoid confusion in mangle_decl. */
525 /* At one time the vtable info was grabbed 2 words at a time. This
526 fails on sparc unless you have 8-byte alignment. (tiemann) */
533 }
535 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
536 or even complete. If this does not exist, create it. If COMPLETE is
537 nonzero, then complete the definition of it -- that will render it
538 impossible to actually build the vtable, but is useful to get at those
539 which are known to exist in the runtime. */
541 tree
543 {
544 tree decl;
553 {
556 }
559 }
561 /* Returns a copy of the BINFO_VIRTUALS list in BINFO. The
562 BV_VCALL_INDEX for each entry is cleared. */
564 static tree
566 {
567 tree copies;
568 tree t;
575 }
577 /* Build the primary virtual function table for TYPE. If BINFO is
578 non-NULL, build the vtable starting with the initial approximation
579 that it is the same as the one which is the head of the association
580 list. Returns a nonzero value if a new vtable is actually
581 created. */
583 static int
585 {
586 tree decl;
587 tree virtuals;
592 {
594 /* We have already created a vtable for this base, so there's
595 no need to do it again. */
602 }
603 else
604 {
607 }
609 #ifdef GATHER_STATISTICS
612 #endif
614 /* Initialize the association list for this type, based
615 on our first approximation. */
620 }
622 /* Give BINFO a new virtual function table which is initialized
623 with a skeleton-copy of its original initialization. The only
624 entry that changes is the `delta' entry, so we can really
625 share a lot of structure.
627 FOR_TYPE is the most derived type which caused this table to
628 be needed.
630 Returns nonzero if we haven't met BINFO before.
632 The order in which vtables are built (by calling this function) for
633 an object must remain the same, otherwise a binary incompatibility
634 can result. */
636 static int
638 {
640 /* We already created a vtable for this base. There's no need to
641 do it again. */
644 /* Remember that we've created a vtable for this BINFO, so that we
645 don't try to do so again. */
648 /* Make fresh virtual list, so we can smash it later. */
651 /* Secondary vtables are laid out as part of the same structure as
652 the primary vtable. */
655 }
657 /* Create a new vtable for BINFO which is the hierarchy dominated by
658 T. Return nonzero if we actually created a new vtable. */
660 static int
662 {
664 /* In this case, it is *type*'s vtable we are modifying. We start
665 with the approximation that its vtable is that of the
666 immediate base class. */
667 /* ??? This actually passes TYPE_BINFO (t), not the primary base binfo,
668 since we've updated DECL_CONTEXT (TYPE_VFIELD (t)) by now. */
670 t);
671 else
672 /* This is our very own copy of `basetype' to play with. Later,
673 we will fill in all the virtual functions that override the
674 virtual functions in these base classes which are not defined
675 by the current type. */
677 }
679 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
680 (which is in the hierarchy dominated by T) list FNDECL as its
681 BV_FN. DELTA is the required constant adjustment from the `this'
682 pointer where the vtable entry appears to the `this' required when
683 the function is actually called. */
685 static void
687 tree binfo,
688 tree fndecl,
689 tree delta,
691 {
692 tree v;
698 {
699 /* We need a new vtable for BINFO. */
701 {
702 /* If we really did make a new vtable, we also made a copy
703 of the BINFO_VIRTUALS list. Now, we have to find the
704 corresponding entry in that list. */
709 }
714 }
715 }
717 \f
718 /* Add method METHOD to class TYPE. If ERROR_P is true, we are adding
719 the method after the class has already been defined because a
720 declaration for it was seen. (Even though that is erroneous, we
721 add the method for improved error recovery.) */
723 void
725 {
729 tree method_vec;
734 /* Make a new method vector. We start with 8 entries. We must
735 allocate at least two (for constructors and destructors), and
736 we're going to end up with an assignment operator at some point
737 as well.
739 We could use a TREE_LIST for now, and convert it to a TREE_VEC
740 in finish_struct, but we would probably waste more memory
741 making the links in the list than we would by over-allocating
742 the size of the vector here. Furthermore, we would complicate
743 all the code that expects this to be a vector. */
749 /* Constructors and destructors go in special slots. */
753 {
756 }
757 else
758 {
761 /* See if we already have an entry with this name. */
763 {
771 {
775 /* If we need to move things up, see if there's
776 space. */
778 {
781 slot++;
782 }
784 }
787 }
790 {
791 /* We need a bigger method vector. */
793 tree new_vec;
795 /* In the non-error case, we are processing a class
796 definition. Double the size of the vector to give room
797 for new methods. */
800 /* In the error case, the vector is already complete. We
801 don't expect many errors, and the rest of the front-end
802 will get confused if there are empty slots in the vector. */
803 else
811 }
814 {
815 /* Type conversion operators have to come before ordinary
816 methods; add_conversions depends on this to speed up
817 looking for conversion operators. So, if necessary, we
818 slide some of the vector elements up. In theory, this
819 makes this algorithm O(N^2) but we don't expect many
820 conversion operators. */
823 else
825 {
829 /* There are no more entries in the vector, so we
830 can insert the new conversion operator here. */
834 /* We can insert the new function right at the
835 SLOTth position. */
837 }
842 /* There is nothing in the Ith slot, so we can avoid
843 moving anything. */
844 ;
845 else
846 {
847 /* We know the last slot in the vector is empty
848 because we know that at this point there's room
849 for a new function. */
854 }
855 }
856 }
859 /* TYPE is a template class. Don't issue any errors now; wait
860 until instantiation time to complain. */
861 ;
862 else
863 {
864 tree fns;
866 /* Check to see if we've already got this method. */
868 fns;
870 {
872 tree parms1;
873 tree parms2;
879 /* [over.load] Member function declarations with the
880 same name and the same parameter types cannot be
881 overloaded if any of them is a static member
882 function declaration.
884 [namespace.udecl] When a using-declaration brings names
885 from a base class into a derived class scope, member
886 functions in the derived class override and/or hide member
887 functions with the same name and parameter types in a base
888 class (rather than conflicting). */
892 /* Compare the quals on the 'this' parm. Don't compare
893 the whole types, as used functions are treated as
894 coming from the using class in overload resolution. */
901 /* For templates, the template parms must be identical. */
916 {
918 /* Defer to the local function. */
920 else
921 {
925 /* We don't call duplicate_decls here to merge
926 the declarations because that will confuse
927 things if the methods have inline
928 definitions. In particular, we will crash
929 while processing the definitions. */
931 }
932 }
933 }
934 }
936 /* Actually insert the new method. */
940 /* Add the new binding. */
945 }
947 /* Subroutines of finish_struct. */
949 /* Look through the list of fields for this struct, deleting
950 duplicates as we go. This must be recursive to handle
951 anonymous unions.
953 FIELD is the field which may not appear anywhere in FIELDS.
954 FIELD_PTR, if non-null, is the starting point at which
955 chained deletions may take place.
956 The value returned is the first acceptable entry found
957 in FIELDS.
959 Note that anonymous fields which are not of UNION_TYPE are
960 not duplicates, they are just anonymous fields. This happens
961 when we have unnamed bitfields, for example. */
963 static tree
965 {
966 tree x;
969 {
976 }
977 else
978 {
980 {
982 {
988 {
991 else
993 }
994 }
996 /* A using declaration is allowed to appear more than
997 once. We'll prune these from the field list later, and
998 handle_using_decl will complain about invalid multiple
999 uses. */
1000 ;
1002 {
1009 x);
1012 {
1016 }
1019 {
1020 /* Hide tag decls. */
1027 x);
1028 }
1029 else
1033 else
1035 }
1036 }
1037 }
1039 }
1041 static void
1043 {
1044 tree x;
1047 }
1049 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1050 legit, otherwise return 0. */
1052 static int
1054 {
1055 tree elem;
1064 {
1066 {
1069 else
1072 }
1073 else
1074 {
1075 /* They're changing the access to the same thing they changed
1076 it to before. That's OK. */
1077 ;
1078 }
1079 }
1080 else
1081 {
1085 }
1087 }
1089 /* Process the USING_DECL, which is a member of T. */
1091 static void
1093 {
1096 tree access
1102 tree old_value;
1109 {
1112 }
1115 {
1118 }
1120 {
1123 }
1128 {
1131 }
1134 /* Ignore base type this came from. */
1139 {
1145 else
1147 }
1153 ;
1155 {
1157 /* It's OK to use functions from a base when there are functions with
1159 else
1160 {
1165 }
1166 }
1168 {
1172 }
1174 /* Make type T see field decl FDECL with access ACCESS.*/
1177 {
1180 }
1181 else
1183 }
1184 \f
1185 /* Run through the base clases of T, updating
1186 CANT_HAVE_DEFAULT_CTOR_P, CANT_HAVE_CONST_CTOR_P, and
1187 NO_CONST_ASN_REF_P. Also set flag bits in T based on properties of
1188 the bases. */
1190 static void
1195 {
1199 tree binfos;
1205 /* An aggregate cannot have baseclasses. */
1209 {
1210 tree base_binfo;
1211 tree basetype;
1213 /* Figure out what base we're looking at. */
1217 /* If the type of basetype is incomplete, then we already
1218 complained about that fact (and we should have fixed it up as
1219 well). */
1221 {
1223 /* The base type is of incomplete type. It is
1224 probably best to pretend that it does not
1225 exist. */
1233 }
1235 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1236 here because the case of virtual functions but non-virtual
1237 dtor is handled in finish_struct_1. */
1241 basetype);
1243 /* If the base class doesn't have copy constructors or
1244 assignment operators that take const references, then the
1245 derived class cannot have such a member automatically
1246 generated. */
1252 /* Similarly, if the base class doesn't have a default
1253 constructor, then the derived class won't have an
1254 automatically generated default constructor. */
1257 {
1261 basetype);
1262 }
1265 /* A virtual base does not effect nearly emptiness. */
1266 ;
1268 {
1270 /* And if there is more than one nearly empty base, then the
1271 derived class is not nearly empty either. */
1273 else
1274 /* Remember we've seen one. */
1276 }
1278 /* If the base class is not empty or nearly empty, then this
1279 class cannot be nearly empty. */
1282 /* A lot of properties from the bases also apply to the derived
1283 class. */
1293 }
1294 }
1296 /* Set BINFO_PRIMARY_BASE_OF for all binfos in the hierarchy
1297 dominated by TYPE that are primary bases. */
1299 static void
1301 {
1302 tree binfo;
1304 /* Walk the bases in inheritance graph order. */
1306 {
1313 else
1314 {
1316 /* A virtual binfo might have been copied from within
1317 another hierarchy. As we're about to use it as a primary
1318 base, make sure the offsets match. */
1320 {
1327 }
1328 }
1329 }
1330 }
1332 /* Make the BINFO the primary base of T. */
1334 static void
1336 {
1337 tree basetype;
1344 }
1346 /* Determine the primary class for T. */
1348 static void
1350 {
1352 tree vbases;
1353 tree type_binfo;
1355 /* If there are no baseclasses, there is certainly no primary base. */
1362 {
1367 {
1368 /* We prefer a non-virtual base, although a virtual one will
1369 do. */
1374 {
1377 }
1378 else
1379 {
1380 tree vfields;
1382 /* Only add unique vfields, and flatten them out as we go. */
1384 vfields;
1392 }
1393 }
1394 }
1399 /* Find the indirect primary bases - those virtual bases which are primary
1400 bases of something else in this hierarchy. */
1402 vbases;
1404 {
1407 /* See if this virtual base is an indirect primary base. To be so,
1408 it must be a primary base within the hierarchy of one of our
1409 direct bases. */
1411 {
1413 tree v;
1416 v;
1418 {
1424 {
1427 }
1428 }
1430 /* If we've discovered that this virtual base is an indirect
1431 primary base, then we can move on to the next virtual
1432 base. */
1435 }
1436 }
1438 /* A "nearly-empty" virtual base class can be the primary base
1439 class, if no non-virtual polymorphic base can be found. */
1441 {
1442 /* If not NULL, this is the best primary base candidate we have
1443 found so far. */
1445 tree base_binfo;
1447 /* Loop over the baseclasses. */
1449 base_binfo;
1451 {
1456 {
1457 /* If this is not an indirect primary base, then it's
1458 definitely our primary base. */
1460 {
1463 }
1465 /* If this is an indirect primary base, it still could be
1466 our primary base -- unless we later find there's another
1467 nearly-empty virtual base that isn't an indirect
1468 primary base. */
1471 }
1472 }
1474 /* If we've got a primary base, use it. */
1476 {
1480 }
1481 }
1483 /* Mark the primary base classes at this point. */
1485 }
1486 \f
1487 /* Set memoizing fields and bits of T (and its variants) for later
1488 use. */
1490 static void
1492 {
1495 /* Fix up variants (if any). */
1498 {
1499 /* These fields are in the _TYPE part of the node, not in
1500 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1511 /* Copy whatever these are holding today. */
1518 }
1521 /* For a class w/o baseclasses, `finish_struct' has set
1522 CLASS_TYPE_ABSTRACT_VIRTUALS correctly (by
1523 definition). Similarly for a class whose base classes do not
1524 have vtables. When neither of these is true, we might have
1525 removed abstract virtuals (by providing a definition), added
1526 some (by declaring new ones), or redeclared ones from a base
1527 class. We need to recalculate what's really an abstract virtual
1528 at this point (by looking in the vtables). */
1532 {
1533 /* Notice whether this class has type conversion functions defined. */
1536 tree basetype;
1539 {
1543 }
1544 }
1546 /* If this type has a copy constructor or a destructor, force its mode to
1547 be BLKmode, and force its TREE_ADDRESSABLE bit to be nonzero. This
1548 will cause it to be passed by invisible reference and prevent it from
1549 being returned in a register. */
1551 {
1552 tree variants;
1555 {
1558 }
1559 }
1560 }
1562 /* Issue warnings about T having private constructors, but no friends,
1563 and so forth.
1565 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1566 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1567 non-private static member functions. */
1569 static void
1571 {
1574 tree fn;
1577 /* If the class has friends, those entities might create and
1578 access instances, so we should not warn. */
1581 /* We will have warned when the template was declared; there's
1582 no need to warn on every instantiation. */
1584 /* There's no reason to even consider warning about this
1585 class. */
1588 /* We only issue one warning, if more than one applies, because
1589 otherwise, on code like:
1591 class A {
1592 // Oops - forgot `public:'
1593 A();
1594 A(const A&);
1595 ~A();
1596 };
1598 we warn several times about essentially the same problem. */
1600 /* Check to see if all (non-constructor, non-destructor) member
1601 functions are private. (Since there are no friends or
1602 non-private statics, we can't ever call any of the private member
1603 functions.) */
1605 /* We're not interested in compiler-generated methods; they don't
1606 provide any way to call private members. */
1608 {
1610 {
1612 /* A non-private static member function is just like a
1613 friend; it can create and invoke private member
1614 functions, and be accessed without a class
1615 instance. */
1619 /* Keep searching for a static member function. */
1620 }
1623 }
1626 {
1627 /* There are no non-private methods, and there's at least one
1628 private member function that isn't a constructor or
1629 destructor. (If all the private members are
1630 constructors/destructors we want to use the code below that
1631 issues error messages specifically referring to
1632 constructors/destructors.) */
1638 {
1641 }
1643 {
1646 }
1647 }
1649 /* Even if some of the member functions are non-private, the class
1650 won't be useful for much if all the constructors or destructors
1651 are private: such an object can never be created or destroyed. */
1654 {
1656 t);
1658 }
1661 {
1664 /* If a non-template class does not define a copy
1665 constructor, one is defined for it, enabling it to avoid
1666 this warning. For a template class, this does not
1667 happen, and so we would normally get a warning on:
1669 template <class T> class C { private: C(); };
1671 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1672 complete non-template or fully instantiated classes have this
1673 flag set. */
1676 else
1678 fn;
1680 {
1682 /* Ideally, we wouldn't count copy constructors (or, in
1683 fact, any constructor that takes an argument of the
1684 class type as a parameter) because such things cannot
1685 be used to construct an instance of the class unless
1686 you already have one. But, for now at least, we're
1687 more generous. */
1689 {
1692 }
1693 }
1696 {
1698 t);
1700 }
1701 }
1702 }
1705 gt_pointer_operator new_value;
1709 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1711 static int
1713 {
1726 }
1728 /* This routine compares two fields like method_name_cmp but using the
1729 pointer operator in resort_field_decl_data. */
1731 static int
1733 {
1742 {
1749 }
1751 }
1753 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1755 void
1758 gt_pointer_operator new_value,
1760 {
1765 /* The type conversion ops have to live at the front of the vec, so we
1766 can't sort them. */
1768 {
1773 }
1775 {
1779 resort_method_name_cmp);
1780 }
1781 }
1783 /* Warn about duplicate methods in fn_fields. Also compact method
1784 lists so that lookup can be made faster.
1786 Data Structure: List of method lists. The outer list is a
1787 TREE_LIST, whose TREE_PURPOSE field is the field name and the
1788 TREE_VALUE is the DECL_CHAIN of the FUNCTION_DECLs. TREE_CHAIN
1789 links the entire list of methods for TYPE_METHODS. Friends are
1790 chained in the same way as member functions (? TREE_CHAIN or
1791 DECL_CHAIN), but they live in the TREE_TYPE field of the outer
1792 list. That allows them to be quickly deleted, and requires no
1793 extra storage.
1795 Sort methods that are not special (i.e., constructors, destructors,
1796 and type conversion operators) so that we can find them faster in
1797 search. */
1799 static void
1801 {
1802 tree fn_fields;
1803 tree method_vec;
1807 {
1808 /* Clear these for safety; perhaps some parsing error could set
1809 these incorrectly. */
1814 }
1820 /* First fill in entry 0 with the constructors, entry 1 with destructors,
1821 and the next few with type conversion operators (if any). */
1824 /* Clear out this flag. */
1828 /* We thought there was a destructor, but there wasn't. Some
1829 parse errors cause this anomalous situation. */
1832 /* Issue warnings about private constructors and such. If there are
1833 no methods, then some public defaults are generated. */
1836 /* Now sort the methods. */
1838 len--;
1841 /* The type conversion ops have to live at the front of the vec, so we
1842 can't sort them. */
1844 {
1849 }
1852 method_name_cmp);
1853 }
1855 /* Make BINFO's vtable have N entries, including RTTI entries,
1856 vbase and vcall offsets, etc. Set its type and call the backend
1857 to lay it out. */
1859 static void
1861 {
1862 tree atype;
1863 tree vtable;
1869 /* We may have to grow the vtable. */
1872 {
1876 }
1877 }
1879 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1880 have the same signature. */
1882 int
1884 {
1885 /* One destructor overrides another if they are the same kind of
1886 destructor. */
1890 /* But a non-destructor never overrides a destructor, nor vice
1891 versa, nor do different kinds of destructors override
1892 one-another. For example, a complete object destructor does not
1893 override a deleting destructor. */
1898 {
1906 }
1908 }
1910 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1911 subobject. */
1913 static bool
1915 {
1916 tree probe;
1919 {
1923 /* If we meet a virtual base, we can't follow the inheritance
1924 any more. See if the complete type of DERIVED contains
1925 such a virtual base. */
1929 }
1931 }
1934 /* The function for which we are trying to find a final overrider. */
1935 tree fn;
1936 /* The base class in which the function was declared. */
1937 tree declaring_base;
1938 /* The most derived class in the hierarchy. */
1939 tree most_derived_type;
1940 /* The candidate overriders. */
1941 tree candidates;
1942 /* Binfos which inherited virtually on the currrent path. */
1943 tree vpath;
1946 /* Called from find_final_overrider via dfs_walk. */
1948 static tree
1950 {
1954 {
1955 /* We've found a path to the declaring base. Walk the path from
1956 derived to base, looking for an overrider for FN. */
1959 /* Build the path, using the inheritance chain and record of
1960 virtual inheritance. */
1962 {
1967 {
1970 }
1971 else
1973 }
1974 /* Now walk path, looking for overrides. */
1976 {
1977 tree method = look_for_overrides_here
1981 {
1985 /* Remove any candidates overridden by this new function. */
1987 {
1988 /* If *CANDIDATE overrides METHOD, then METHOD
1989 cannot override anything else on the list. */
1992 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1995 else
1997 }
1999 /* Add the new function. */
2002 }
2003 }
2004 }
2007 }
2009 static tree
2011 {
2019 }
2021 static tree
2023 {
2030 }
2032 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2033 FN and whose TREE_VALUE is the binfo for the base where the
2034 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2035 DERIVED) is the base object in which FN is declared. */
2037 static tree
2039 {
2040 find_final_overrider_data ffod;
2042 /* Getting this right is a little tricky. This is valid:
2044 struct S { virtual void f (); };
2045 struct T { virtual void f (); };
2046 struct U : public S, public T { };
2048 even though calling `f' in `U' is ambiguous. But,
2050 struct R { virtual void f(); };
2051 struct S : virtual public R { virtual void f (); };
2052 struct T : virtual public R { virtual void f (); };
2053 struct U : public S, public T { };
2055 is not -- there's no way to decide whether to put `S::f' or
2056 `T::f' in the vtable for `R'.
2058 The solution is to look at all paths to BINFO. If we find
2059 different overriders along any two, then there is a problem. */
2070 dfs_find_final_overrider,
2071 dfs_find_final_overrider_post,
2072 dfs_find_final_overrider_q,
2075 /* If there was no winner, issue an error message. */
2077 {
2081 }
2084 }
2086 /* Return the index of the vcall offset for FN when TYPE is used as a
2087 virtual base. */
2089 static tree
2091 {
2092 tree v;
2099 /* There should always be an appropriate index. */
2103 }
2105 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2106 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2107 corresponding position in the BINFO_VIRTUALS list. */
2109 static void
2112 {
2113 tree b;
2114 tree overrider;
2115 tree delta;
2116 tree virtual_base;
2117 tree first_defn;
2123 /* Find the nearest primary base (possibly binfo itself) which defines
2124 this function; this is the class the caller will convert to when
2125 calling FN through BINFO. */
2127 {
2132 /* The nearest definition is from a lost primary. */
2135 }
2138 /* Find the final overrider. */
2144 /* Check for adjusting covariant return types. */
2152 {
2153 /* If FN is a covariant thunk, we must figure out the adjustment
2154 to the final base FN was converting to. As OVERRIDER_TARGET might
2155 also be converting to the return type of FN, we have to
2156 combine the two conversions here. */
2160 {
2163 }
2164 else
2168 {
2169 /* There was no existing virtual thunk (which takes
2170 precidence). */
2171 tree thunk_binfo;
2172 base_kind kind;
2180 {
2184 {
2185 /* We convert via virtual base. Find the virtual
2186 base and adjust the fixed offset to be from there. */
2193 }
2195 /* There was an existing fixed offset, this must be
2196 from the base just converted to, and the base the
2197 FN was thunking to. */
2199 else
2201 }
2202 }
2205 /* Replace the overriding function with a covariant thunk. We
2206 will emit the overriding function in its own slot as
2207 well. */
2210 }
2211 else
2214 /* Assume that we will produce a thunk that convert all the way to
2215 the final overrider, and not to an intermediate virtual base. */
2218 /* See if we can convert to an intermediate virtual base first, and then
2219 use the vcall offset located there to finish the conversion. */
2221 {
2222 /* If we find the final overrider, then we can stop
2223 walking. */
2228 /* If we find a virtual base, and we haven't yet found the
2229 overrider, then there is a virtual base between the
2230 declaring base (first_defn) and the final overrider. */
2232 {
2235 }
2236 }
2239 {
2240 /* The ABI specifies that a covariant thunk includes a mangling
2241 for a this pointer adjustment. This-adjusting thunks that
2242 override a function from a virtual base have a vcall
2243 adjustment. When the virtual base in question is a primary
2244 virtual base, we know the adjustments are zero, (and in the
2245 non-covariant case, we would not use the thunk).
2246 Unfortunately we didn't notice this could happen, when
2247 designing the ABI and so never mandated that such a covariant
2248 thunk should be emitted. Because we must use the ABI mandated
2249 name, we must continue searching from the binfo where we
2250 found the most recent definition of the function, towards the
2251 primary binfo which first introduced the function into the
2252 vtable. If that enters a virtual base, we must use a vcall
2253 this-adjusting thunk. Bleah! */
2254 tree probe;
2257 {
2262 }
2264 /* Even if we find a virtual base, the correct delta is
2265 between the overrider and the binfo we're building a vtable
2266 for. */
2268 }
2270 /* Compute the constant adjustment to the `this' pointer. The
2271 `this' pointer, when this function is called, will point at BINFO
2272 (or one of its primary bases, which are at the same offset). */
2274 /* The `this' pointer needs to be adjusted from the declaration to
2275 the nearest virtual base. */
2279 /* If the nearest definition is in a lost primary, we don't need an
2280 entry in our vtable. Except possibly in a constructor vtable,
2281 if we happen to get our primary back. In that case, the offset
2282 will be zero, as it will be a primary base. */
2284 else
2285 /* The `this' pointer needs to be adjusted from pointing to
2286 BINFO to pointing at the base where the final overrider
2287 appears. */
2288 virtual_covariant:
2297 }
2299 /* Called from modify_all_vtables via dfs_walk. */
2301 static tree
2303 {
2305 primary base; we're not going to use that vtable anyhow.
2306 We do still need to do this for virtual primary bases, as they
2307 could become non-primary in a construction vtable. */
2309 /* Similarly, a base without a vtable needs no modification. */
2311 {
2313 tree virtuals;
2314 tree old_virtuals;
2319 /* Now, go through each of the virtual functions in the virtual
2320 function table for BINFO. Find the final overrider, and
2321 update the BINFO_VIRTUALS list appropriately. */
2324 virtuals;
2328 binfo,
2331 }
2336 }
2338 /* Update all of the primary and secondary vtables for T. Create new
2339 vtables as required, and initialize their RTTI information. Each
2340 of the functions in VIRTUALS is declared in T and may override a
2341 virtual function from a base class; find and modify the appropriate
2342 entries to point to the overriding functions. Returns a list, in
2343 declaration order, of the virtual functions that are declared in T,
2344 but do not appear in the primary base class vtable, and which
2345 should therefore be appended to the end of the vtable for T. */
2347 static tree
2349 {
2353 /* Update all of the vtables. */
2357 /* Add virtual functions not already in our primary vtable. These
2358 will be both those introduced by this class, and those overridden
2359 from secondary bases. It does not include virtuals merely
2360 inherited from secondary bases. */
2362 {
2367 {
2368 /* We don't need to adjust the `this' pointer when
2369 calling this function. */
2373 /* This is a function not already in our vtable. Keep it. */
2375 }
2376 else
2377 /* We've already got an entry for this function. Skip it. */
2379 }
2382 }
2384 /* Get the base virtual function declarations in T that have the
2385 indicated NAME. */
2387 static tree
2389 {
2390 tree methods;
2395 /* Find virtual functions in T with the indicated NAME. */
2399 methods;
2401 {
2407 }
2413 {
2416 base_fndecls);
2417 }
2420 }
2422 /* If this declaration supersedes the declaration of
2423 a method declared virtual in the base class, then
2424 mark this field as being virtual as well. */
2426 static void
2428 {
2430 /* In [temp.mem] we have:
2432 A specialization of a member function template does not
2433 override a virtual function from a base class. */
2439 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2440 the error_mark_node so that we know it is an overriding
2441 function. */
2445 {
2449 }
2450 }
2452 /* Warn about hidden virtual functions that are not overridden in t.
2453 We know that constructors and destructors don't apply. */
2455 void
2457 {
2462 /* We go through each separately named virtual function. */
2464 {
2465 tree fns;
2466 tree name;
2467 tree fndecl;
2468 tree base_fndecls;
2471 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2472 have the same name. Figure out what name that is. */
2474 /* There are no possibly hidden functions yet. */
2476 /* Iterate through all of the base classes looking for possibly
2477 hidden functions. */
2479 {
2482 base_fndecls);
2483 }
2485 /* If there are no functions to hide, continue. */
2489 /* Remove any overridden functions. */
2491 {
2494 {
2498 /* If the method from the base class has the same
2499 signature as the method from the derived class, it
2500 has been overridden. */
2503 else
2505 }
2506 }
2508 /* Now give a warning for all base functions without overriders,
2509 as they are hidden. */
2511 {
2512 /* Here we know it is a hider, and no overrider exists. */
2517 }
2518 }
2519 }
2521 /* Check for things that are invalid. There are probably plenty of other
2522 things we should check for also. */
2524 static void
2526 {
2527 tree field;
2530 {
2538 {
2541 {
2542 /* We're generally only interested in entities the user
2543 declared, but we also find nested classes by noticing
2544 the TYPE_DECL that we create implicitly. You're
2545 allowed to put one anonymous union inside another,
2546 though, so we explicitly tolerate that. We use
2547 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2548 we also allow unnamed types used for defining fields. */
2556 elt);
2559 {
2561 elt);
2563 }
2567 elt);
2570 elt);
2574 }
2575 }
2576 }
2577 }
2579 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2580 will be used later during class template instantiation.
2581 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2582 a non-static member data (FIELD_DECL), a member function
2583 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2584 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2585 When FRIEND_P is nonzero, T is either a friend class
2586 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2587 (FUNCTION_DECL, TEMPLATE_DECL). */
2589 void
2591 {
2592 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2597 }
2599 /* Create default constructors, assignment operators, and so forth for
2600 the type indicated by T, if they are needed.
2601 CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2602 CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2603 class cannot have a default constructor, copy constructor taking a
2604 const reference argument, or an assignment operator taking a const
2605 reference, respectively. If a virtual destructor is created, its
2606 DECL is returned; otherwise the return value is NULL_TREE. */
2608 static void
2613 {
2614 tree default_fn;
2621 /* Destructor. */
2623 {
2627 /* If we couldn't make it work, then pretend we didn't need it. */
2630 else
2631 {
2637 }
2638 }
2639 else
2640 /* Any non-implicit destructor is non-trivial. */
2643 /* Default constructor. */
2645 {
2649 }
2651 /* Copy constructor. */
2653 {
2654 /* ARM 12.18: You get either X(X&) or X(const X&), but
2655 not both. --Chip */
2656 default_fn
2661 }
2663 /* Assignment operator. */
2665 {
2666 default_fn
2671 }
2673 /* Now, hook all of the new functions on to TYPE_METHODS,
2674 and add them to the CLASSTYPE_METHOD_VEC. */
2676 {
2679 }
2681 /* G++ 3.2 put the implicit destructor at the *beginning* of the
2682 list, which cause the destructor to be emitted in an incorrect
2683 location in the vtable. */
2685 else
2686 {
2689 "and may change in a future version of GCC due to implicit "
2691 t);
2694 }
2697 }
2699 /* Subroutine of finish_struct_1. Recursively count the number of fields
2700 in TYPE, including anonymous union members. */
2702 static int
2704 {
2705 tree x;
2708 {
2711 else
2713 }
2715 }
2717 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2718 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2720 static int
2722 {
2723 tree x;
2725 {
2728 else
2730 }
2732 }
2734 /* FIELD is a bit-field. We are finishing the processing for its
2735 enclosing type. Issue any appropriate messages and set appropriate
2736 flags. */
2738 static void
2740 {
2744 /* Detect invalid bit-field type. */
2747 {
2750 }
2752 /* Detect and ignore out of range field width. */
2754 {
2757 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2760 /* detect invalid field size. */
2763 else
2767 {
2769 field);
2771 }
2773 {
2776 }
2778 {
2781 }
2791 min_precision
2796 }
2798 /* Remove the bit-field width indicator so that the rest of the
2799 compiler does not treat that value as an initializer. */
2803 {
2806 }
2807 else
2808 {
2809 /* Non-bit-fields are aligned for their type. */
2812 }
2813 }
2815 /* FIELD is a non bit-field. We are finishing the processing for its
2816 enclosing type T. Issue any appropriate messages and set appropriate
2817 flags. */
2819 static void
2821 tree t,
2826 {
2829 /* An anonymous union cannot contain any fields which would change
2830 the settings of CANT_HAVE_CONST_CTOR and friends. */
2832 ;
2833 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2834 structs. So, we recurse through their fields here. */
2836 {
2837 tree fields;
2843 any_default_members);
2844 }
2845 /* Check members with class type for constructors, destructors,
2846 etc. */
2848 {
2849 /* Never let anything with uninheritable virtuals
2850 make it through without complaint. */
2854 {
2857 field);
2860 field);
2863 field);
2864 }
2865 else
2866 {
2872 }
2883 }
2885 {
2886 /* `build_class_init_list' does not recognize
2887 non-FIELD_DECLs. */
2891 }
2892 }
2894 /* Check the data members (both static and non-static), class-scoped
2895 typedefs, etc., appearing in the declaration of T. Issue
2896 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2897 declaration order) of access declarations; each TREE_VALUE in this
2898 list is a USING_DECL.
2900 In addition, set the following flags:
2902 EMPTY_P
2903 The class is empty, i.e., contains no non-static data members.
2905 CANT_HAVE_DEFAULT_CTOR_P
2906 This class cannot have an implicitly generated default
2907 constructor.
2909 CANT_HAVE_CONST_CTOR_P
2910 This class cannot have an implicitly generated copy constructor
2911 taking a const reference.
2913 CANT_HAVE_CONST_ASN_REF
2914 This class cannot have an implicitly generated assignment
2915 operator taking a const reference.
2917 All of these flags should be initialized before calling this
2918 function.
2920 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2921 fields can be added by adding to this chain. */
2923 static void
2928 {
2934 /* First, delete any duplicate fields. */
2937 /* Assume there are no access declarations. */
2939 /* Assume this class has no pointer members. */
2941 /* Assume none of the members of this class have default
2942 initializations. */
2946 {
2953 {
2955 {
2957 cp_warning_at
2959 x);
2960 else
2962 }
2965 /* We don't treat zero-width bitfields as making a class
2966 non-empty. */
2967 ;
2968 else
2969 {
2970 tree element_type;
2972 /* The class is non-empty. */
2974 /* The class is not even nearly empty. */
2976 /* If one of the data members contains an empty class,
2977 so does T. */
2982 }
2983 }
2986 {
2987 /* Prune the access declaration from the list of fields. */
2990 /* Save the access declarations for our caller. */
2993 /* Since we've reset *FIELD there's no reason to skip to the
2994 next field. */
2997 }
3003 /* If we've gotten this far, it's a data member, possibly static,
3004 or an enumerator. */
3008 /* ``A local class cannot have static data members.'' ARM 9.4 */
3012 /* Perform error checking that did not get done in
3013 grokdeclarator. */
3015 {
3017 x);
3020 }
3022 {
3026 }
3031 /* When this goes into scope, it will be a non-local reference. */
3038 {
3040 /* Unions cannot have static members. */
3044 }
3046 /* Now it can only be a FIELD_DECL. */
3051 /* If this is of reference type, check if it needs an init.
3052 Also do a little ANSI jig if necessary. */
3054 {
3059 /* ARM $12.6.2: [A member initializer list] (or, for an
3060 aggregate, initialization by a brace-enclosed list) is the
3061 only way to initialize nonstatic const and reference
3062 members. */
3069 }
3080 /* DR 148 now allows pointers to members (which are POD themselves),
3081 to be allowed in POD structs. */
3087 /* If any field is const, the structure type is pseudo-const. */
3089 {
3094 /* ARM $12.6.2: [A member initializer list] (or, for an
3095 aggregate, initialization by a brace-enclosed list) is the
3096 only way to initialize nonstatic const and reference
3097 members. */
3104 }
3105 /* A field that is pseudo-const makes the structure likewise. */
3107 {
3112 }
3114 /* Core issue 80: A nonstatic data member is required to have a
3115 different name from the class iff the class has a
3116 user-defined constructor. */
3120 /* We set DECL_C_BIT_FIELD in grokbitfield.
3121 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3124 else
3126 cant_have_const_ctor_p,
3127 cant_have_default_ctor_p,
3128 no_const_asn_ref_p,
3130 }
3132 /* Effective C++ rule 11. */
3135 {
3139 {
3143 }
3146 }
3149 /* Check anonymous struct/anonymous union fields. */
3152 /* We've built up the list of access declarations in reverse order.
3153 Fix that now. */
3155 }
3157 /* If TYPE is an empty class type, records its OFFSET in the table of
3158 OFFSETS. */
3160 static int
3162 {
3163 splay_tree_node n;
3168 /* Record the location of this empty object in OFFSETS. */
3176 type,
3180 }
3182 /* Returns nonzero if TYPE is an empty class type and there is
3183 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3185 static int
3187 {
3188 splay_tree_node n;
3189 tree t;
3194 /* Record the location of this empty object in OFFSETS. */
3204 }
3206 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3207 F for every subobject, passing it the type, offset, and table of
3208 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3209 be traversed.
3211 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3212 than MAX_OFFSET will not be walked.
3214 If F returns a nonzero value, the traversal ceases, and that value
3215 is returned. Otherwise, returns zero. */
3217 static int
3219 subobject_offset_fn f,
3220 tree offset,
3221 splay_tree offsets,
3222 tree max_offset,
3224 {
3228 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3229 stop. */
3234 {
3238 }
3241 {
3242 tree field;
3243 tree binfo;
3246 /* Avoid recursing into objects that are not interesting. */
3250 /* Record the location of TYPE. */
3255 /* Iterate through the direct base classes of TYPE. */
3259 {
3260 tree binfo_offset;
3275 offset,
3277 else
3278 {
3279 tree orig_binfo;
3280 /* We cannot rely on BINFO_OFFSET being set for the base
3281 class yet, but the offsets for direct non-virtual
3282 bases can be calculated by going back to the TYPE. */
3285 offset,
3287 }
3290 f,
3291 binfo_offset,
3292 offsets,
3293 max_offset,
3298 }
3301 {
3302 tree vbase;
3304 /* Iterate through the virtual base classes of TYPE. In G++
3305 3.2, we included virtual bases in the direct base class
3306 loop above, which results in incorrect results; the
3307 correct offsets for virtual bases are only known when
3308 working with the most derived type. */
3311 vbase;
3313 {
3316 f,
3318 offset,
3320 offsets,
3321 max_offset,
3325 }
3326 else
3327 {
3328 /* We still have to walk the primary base, if it is
3329 virtual. (If it is non-virtual, then it was walked
3330 above.) */
3334 {
3335 r = (walk_subobject_offsets
3340 }
3341 }
3342 }
3344 /* Iterate through the fields of TYPE. */
3347 {
3348 tree field_offset;
3352 else
3353 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3357 f,
3359 offset,
3360 field_offset),
3361 offsets,
3362 max_offset,
3366 }
3367 }
3369 {
3372 tree index;
3374 /* Avoid recursing into objects that are not interesting. */
3379 /* Step through each of the elements in the array. */
3381 /* G++ 3.2 had an off-by-one error here. */
3386 {
3388 f,
3389 offset,
3390 offsets,
3391 max_offset,
3397 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3398 there's no point in iterating through the remaining
3399 elements of the array. */
3402 }
3403 }
3406 }
3408 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3409 OFFSETS. If VBASES_P is nonzero, virtual bases of TYPE are
3410 examined. */
3412 static void
3414 tree offset,
3415 splay_tree offsets,
3417 {
3420 }
3422 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3423 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3424 virtual bases of TYPE are examined. */
3426 static int
3428 tree offset,
3429 splay_tree offsets,
3431 {
3432 splay_tree_node max_node;
3434 /* Get the node in OFFSETS that indicates the maximum offset where
3435 an empty subobject is located. */
3437 /* If there aren't any empty subobjects, then there's no point in
3438 performing this check. */
3444 vbases_p);
3445 }
3447 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3448 non-static data member of the type indicated by RLI. BINFO is the
3449 binfo corresponding to the base subobject, OFFSETS maps offsets to
3450 types already located at those offsets. This function determines
3451 the position of the DECL. */
3453 static void
3455 tree decl,
3456 tree binfo,
3457 splay_tree offsets)
3458 {
3461 tree type;
3464 {
3465 /* For the purposes of determining layout conflicts, we want to
3466 use the class type of BINFO; TREE_TYPE (DECL) will be the
3467 CLASSTYPE_AS_BASE version, which does not contain entries for
3468 zero-sized bases. */
3471 }
3472 else
3473 {
3476 }
3478 /* Try to place the field. It may take more than one try if we have
3479 a hard time placing the field without putting two objects of the
3480 same type at the same address. */
3482 {
3485 /* Place this field. */
3489 /* We have to check to see whether or not there is already
3490 something of the same type at the offset we're about to use.
3491 For example:
3493 struct S {};
3494 struct T : public S { int i; };
3495 struct U : public S, public T {};
3497 Here, we put S at offset zero in U. Then, we can't put T at
3498 offset zero -- its S component would be at the same address
3499 as the S we already allocated. So, we have to skip ahead.
3500 Since all data members, including those whose type is an
3501 empty class, have nonzero size, any overlap can happen only
3502 with a direct or indirect base-class -- it can't happen with
3503 a data member. */
3504 /* G++ 3.2 did not check for overlaps when placing a non-empty
3505 virtual base. */
3510 {
3511 /* Strip off the size allocated to this field. That puts us
3512 at the first place we could have put the field with
3513 proper alignment. */
3516 /* Bump up by the alignment required for the type. */
3517 rli->bitpos
3523 }
3524 else
3525 /* There was no conflict. We're done laying out this field. */
3527 }
3529 /* Now that we know where it will be placed, update its
3530 BINFO_OFFSET. */
3532 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3533 this point because their BINFO_OFFSET is copied from another
3534 hierarchy. Therefore, we may not need to add the entire
3535 OFFSET. */
3540 }
3542 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3544 static int
3546 tree offset,
3547 splay_tree offsets ATTRIBUTE_UNUSED)
3548 {
3550 }
3552 /* Layout the empty base BINFO. EOC indicates the byte currently just
3553 past the end of the class, and should be correctly aligned for a
3554 class of the type indicated by BINFO; OFFSETS gives the offsets of
3555 the empty bases allocated so far. T is the most derived
3556 type. Return nonzero iff we added it at the end. */
3558 static bool
3560 {
3561 tree alignment;
3565 /* This routine should only be used for empty classes. */
3576 /* This is an empty base class. We first try to put it at offset
3577 zero. */
3580 offsets,
3582 {
3583 /* That didn't work. Now, we move forward from the next
3584 available spot in the class. */
3588 {
3591 offsets,
3593 /* We finally found a spot where there's no overlap. */
3596 /* There's overlap here, too. Bump along to the next spot. */
3598 }
3599 }
3601 }
3603 /* Layout the the base given by BINFO in the class indicated by RLI.
3604 *BASE_ALIGN is a running maximum of the alignments of
3605 any base class. OFFSETS gives the location of empty base
3606 subobjects. T is the most derived type. Return nonzero if the new
3607 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3608 *NEXT_FIELD, unless BINFO is for an empty base class.
3610 Returns the location at which the next field should be inserted. */
3615 {
3620 /* This error is now reported in xref_tag, thus giving better
3621 location information. */
3624 /* Place the base class. */
3626 {
3627 tree decl;
3629 /* The containing class is non-empty because it has a non-empty
3630 base class. */
3633 /* Create the FIELD_DECL. */
3643 /* Try to place the field. It may take more than one try if we
3644 have a hard time placing the field without putting two
3645 objects of the same type at the same address. */
3647 /* Add the new FIELD_DECL to the list of fields for T. */
3651 }
3652 else
3653 {
3654 tree eoc;
3657 /* On some platforms (ARM), even empty classes will not be
3658 byte-aligned. */
3662 /* A nearly-empty class "has no proper base class that is empty,
3663 not morally virtual, and at an offset other than zero." */
3665 {
3668 /* The check above (used in G++ 3.2) is insufficient because
3669 an empty class placed at offset zero might itself have an
3670 empty base at a nonzero offset. */
3672 empty_base_at_nonzero_offset_p,
3673 size_zero_node,
3677 {
3683 }
3684 }
3686 /* We do not create a FIELD_DECL for empty base classes because
3687 it might overlap some other field. We want to be able to
3688 create CONSTRUCTORs for the class by iterating over the
3689 FIELD_DECLs, and the back end does not handle overlapping
3690 FIELD_DECLs. */
3692 /* An empty virtual base causes a class to be non-empty
3693 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3694 here because that was already done when the virtual table
3695 pointer was created. */
3696 }
3698 /* Record the offsets of BINFO and its base subobjects. */
3701 offsets,
3705 }
3707 /* Layout all of the non-virtual base classes. Record empty
3708 subobjects in OFFSETS. T is the most derived type. Return nonzero
3709 if the type cannot be nearly empty. The fields created
3710 corresponding to the base classes will be inserted at
3711 *NEXT_FIELD. */
3713 static void
3716 {
3717 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3718 subobjects. */
3723 /* The primary base class is always allocated first. */
3728 /* Now allocate the rest of the bases. */
3730 {
3731 tree base_binfo;
3735 /* The primary base was already allocated above, so we don't
3736 need to allocate it again here. */
3740 /* Virtual bases are added at the end (a primary virtual base
3741 will have already been added). */
3747 }
3748 }
3750 /* Go through the TYPE_METHODS of T issuing any appropriate
3751 diagnostics, figuring out which methods override which other
3752 methods, and so forth. */
3754 static void
3756 {
3757 tree x;
3760 {
3761 /* If this was an evil function, don't keep it in class. */
3770 /* The name of the field is the original field name
3771 Save this in auxiliary field for later overloading. */
3773 {
3778 }
3779 }
3780 }
3782 /* FN is a constructor or destructor. Clone the declaration to create
3783 a specialized in-charge or not-in-charge version, as indicated by
3784 NAME. */
3786 static tree
3788 {
3789 tree parms;
3790 tree clone;
3792 /* Copy the function. */
3794 /* Remember where this function came from. */
3797 /* Reset the function name. */
3800 /* There's no pending inline data for this function. */
3803 /* And it hasn't yet been deferred. */
3806 /* The base-class destructor is not virtual. */
3808 {
3812 }
3814 /* If there was an in-charge parameter, drop it from the function
3815 type. */
3817 {
3818 tree basetype;
3819 tree parmtypes;
3820 tree exceptions;
3825 /* Skip the `this' parameter. */
3827 /* Skip the in-charge parameter. */
3829 /* And the VTT parm, in a complete [cd]tor. */
3833 /* If this is subobject constructor or destructor, add the vtt
3834 parameter. */
3838 parmtypes);
3841 exceptions);
3842 }
3844 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3845 aren't function parameters; those are the template parameters. */
3847 {
3849 /* Remove the in-charge parameter. */
3851 {
3855 }
3856 /* And the VTT parm, in a complete [cd]tor. */
3858 {
3861 else
3862 {
3866 }
3867 }
3870 {
3873 }
3874 }
3876 /* Create the RTL for this function. */
3880 /* Make it easy to find the CLONE given the FN. */
3884 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3886 {
3887 tree result;
3894 }
3899 }
3901 /* Produce declarations for all appropriate clones of FN. If
3902 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3903 CLASTYPE_METHOD_VEC as well. */
3905 void
3907 {
3908 tree clone;
3910 /* Avoid inappropriate cloning. */
3916 {
3917 /* For each constructor, we need two variants: an in-charge version
3918 and a not-in-charge version. */
3925 }
3926 else
3927 {
3930 /* For each destructor, we need three variants: an in-charge
3931 version, a not-in-charge version, and an in-charge deleting
3932 version. We clone the deleting version first because that
3933 means it will go second on the TYPE_METHODS list -- and that
3934 corresponds to the correct layout order in the virtual
3935 function table.
3937 For a non-virtual destructor, we do not build a deleting
3938 destructor. */
3940 {
3944 }
3951 }
3953 /* Note that this is an abstract function that is never emitted. */
3955 }
3957 /* DECL is an in charge constructor, which is being defined. This will
3958 have had an in class declaration, from whence clones were
3959 declared. An out-of-class definition can specify additional default
3960 arguments. As it is the clones that are involved in overload
3961 resolution, we must propagate the information from the DECL to its
3962 clones. */
3964 void
3966 {
3967 tree clone;
3971 {
3978 /* Skip the 'this' parameter. */
3994 {
3999 {
4000 /* A default parameter has been added. Adjust the
4001 clone's parameters. */
4004 tree type;
4009 {
4012 clone_parms);
4014 }
4017 clone_parms);
4024 }
4025 }
4027 }
4028 }
4030 /* For each of the constructors and destructors in T, create an
4031 in-charge and not-in-charge variant. */
4033 static void
4035 {
4036 tree fns;
4038 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4039 out now. */
4047 }
4049 /* Remove all zero-width bit-fields from T. */
4051 static void
4053 {
4058 {
4063 else
4065 }
4066 }
4068 /* Returns TRUE iff we need a cookie when dynamically allocating an
4069 array whose elements have the indicated class TYPE. */
4071 static bool
4073 {
4074 tree fns;
4079 /* If there's a non-trivial destructor, we need a cookie. In order
4080 to iterate through the array calling the destructor for each
4081 element, we'll have to know how many elements there are. */
4085 /* If the usual deallocation function is a two-argument whose second
4086 argument is of type `size_t', then we have to pass the size of
4087 the array to the deallocation function, so we will need to store
4088 a cookie. */
4092 /* If there are no `operator []' members, or the lookup is
4093 ambiguous, then we don't need a cookie. */
4096 /* Loop through all of the functions. */
4098 {
4099 tree fn;
4100 tree second_parm;
4102 /* Select the current function. */
4104 /* See if this function is a one-argument delete function. If
4105 it is, then it will be the usual deallocation function. */
4109 /* Otherwise, if we have a two-argument function and the second
4110 argument is `size_t', it will be the usual deallocation
4111 function -- unless there is one-argument function, too. */
4115 }
4118 }
4120 /* Check the validity of the bases and members declared in T. Add any
4121 implicitly-generated functions (like copy-constructors and
4122 assignment operators). Compute various flag bits (like
4123 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4124 level: i.e., independently of the ABI in use. */
4126 static void
4128 {
4129 /* Nonzero if we are not allowed to generate a default constructor
4130 for this case. */
4132 /* Nonzero if the implicitly generated copy constructor should take
4133 a non-const reference argument. */
4135 /* Nonzero if the the implicitly generated assignment operator
4136 should take a non-const reference argument. */
4138 tree access_decls;
4140 /* By default, we use const reference arguments and generate default
4141 constructors. */
4146 /* Check all the base-classes. */
4150 /* Check all the data member declarations. */
4156 /* Check all the method declarations. */
4159 /* A nearly-empty class has to be vptr-containing; a nearly empty
4160 class contains just a vptr. */
4164 /* Do some bookkeeping that will guide the generation of implicitly
4165 declared member functions. */
4183 /* Synthesize any needed methods. Note that methods will be synthesized
4184 for anonymous unions; grok_x_components undoes that. */
4186 cant_have_const_ctor,
4187 no_const_asn_ref);
4189 /* Create the in-charge and not-in-charge variants of constructors
4190 and destructors. */
4193 /* Process the using-declarations. */
4197 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4200 /* Figure out whether or not we will need a cookie when dynamically
4201 allocating an array of this type. */
4204 }
4206 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4207 accordingly. If a new vfield was created (because T doesn't have a
4208 primary base class), then the newly created field is returned. It
4209 is not added to the TYPE_FIELDS list; it is the caller's
4210 responsibility to do that. Accumulate declared virtual functions
4211 on VIRTUALS_P. */
4213 static tree
4215 {
4216 tree fn;
4218 /* Collect the virtual functions declared in T. */
4222 {
4230 }
4232 /* If we couldn't find an appropriate base class, create a new field
4233 here. Even if there weren't any new virtual functions, we might need a
4234 new virtual function table if we're supposed to include vptrs in
4235 all classes that need them. */
4237 {
4238 /* We build this decl with vtbl_ptr_type_node, which is a
4239 `vtable_entry_type*'. It might seem more precise to use
4240 `vtable_entry_type (*)[N]' where N is the number of firtual
4241 functions. However, that would require the vtable pointer in
4242 base classes to have a different type than the vtable pointer
4243 in derived classes. We could make that happen, but that
4244 still wouldn't solve all the problems. In particular, the
4245 type-based alias analysis code would decide that assignments
4246 to the base class vtable pointer can't alias assignments to
4247 the derived class vtable pointer, since they have different
4248 types. Thus, in a derived class destructor, where the base
4249 class constructor was inlined, we could generate bad code for
4250 setting up the vtable pointer.
4252 Therefore, we use one type for all vtable pointers. We still
4253 use a type-correct type; it's just doesn't indicate the array
4254 bounds. That's better than using `void*' or some such; it's
4255 cleaner, and it let's the alias analysis code know that these
4256 stores cannot alias stores to void*! */
4257 tree field;
4268 /* This class is non-empty. */
4272 /* If there were any baseclasses, they can't possibly be at
4273 offset zero any more, because that's where the vtable
4274 pointer is. So, converting to a base class is going to
4275 take work. */
4279 }
4282 }
4284 /* Fixup the inline function given by INFO now that the class is
4285 complete. */
4287 static void
4289 {
4291 {
4294 {
4297 }
4298 }
4299 }
4301 /* Fixup the inline methods and friends in TYPE now that TYPE is
4302 complete. */
4304 static void
4306 {
4310 {
4315 else
4317 }
4319 /* Do inline member functions. */
4323 /* Do friends. */
4325 method;
4329 }
4331 /* Add OFFSET to all base types of BINFO which is a base in the
4332 hierarchy dominated by T.
4334 OFFSET, which is a type offset, is number of bytes. */
4336 static void
4338 {
4340 tree primary_binfo;
4342 /* Update BINFO's offset. */
4347 offset));
4349 /* Find the primary base class. */
4352 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4353 downwards. */
4355 {
4356 tree base_binfo;
4358 /* On the first time through the loop, do the primary base.
4359 Because the primary base need not be an immediate base, we
4360 must handle the primary base specially. */
4362 {
4367 }
4368 else
4369 {
4371 /* Don't do the primary base twice. */
4374 }
4376 /* Skip virtual bases that aren't our canonical primary base. */
4382 }
4383 }
4385 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4386 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4387 empty subobjects of T. */
4389 static void
4391 {
4392 tree vbase;
4401 {
4402 /* In G++ 3.2, we incorrectly rounded the size before laying out
4403 the virtual bases. */
4405 #ifdef STRUCTURE_SIZE_BOUNDARY
4406 /* Packed structures don't need to have minimum size. */
4409 #endif
4413 }
4415 /* Find the last field. The artificial fields created for virtual
4416 bases will go after the last extant field to date. */
4421 /* Go through the virtual bases, allocating space for each virtual
4422 base that is not already a primary base class. These are
4423 allocated in inheritance graph order. */
4425 {
4430 {
4433 /* This virtual base is not a primary base of any class in the
4434 hierarchy, so we have to add space for it. */
4438 /* If the first virtual base might have been placed at a
4439 lower address, had we started from CLASSTYPE_SIZE, rather
4440 than TYPE_SIZE, issue a warning. There can be both false
4441 positives and false negatives from this warning in rare
4442 cases; to deal with all the possibilities would probably
4443 require performing both layout algorithms and comparing
4444 the results which is not particularly tractable. */
4446 && first_vbase
4447 && (tree_int_cst_lt
4451 bitsize_unit_node),
4453 warning ("offset of virtual base `%T' is not ABI-compliant and may change in a future version of GCC",
4454 basetype);
4457 }
4458 }
4459 }
4461 /* Returns the offset of the byte just past the end of the base class
4462 BINFO. */
4464 static tree
4466 {
4467 tree size;
4470 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4471 allocate some space for it. It cannot have virtual bases, so
4472 TYPE_SIZE_UNIT is fine. */
4474 else
4478 }
4480 /* Returns the offset of the byte just past the end of the base class
4481 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4482 only non-virtual bases are included. */
4484 static tree
4486 {
4488 tree binfo;
4489 tree offset;
4493 {
4504 }
4506 /* G++ 3.2 did not check indirect virtual bases. */
4509 binfo;
4511 {
4515 }
4518 }
4520 /* Warn about bases of T that are inaccessible because they are
4521 ambiguous. For example:
4523 struct S {};
4524 struct T : public S {};
4525 struct U : public S, public T {};
4527 Here, `(S*) new U' is not allowed because there are two `S'
4528 subobjects of U. */
4530 static void
4532 {
4534 tree vbases;
4535 tree basetype;
4537 /* Check direct bases. */
4539 {
4545 }
4547 /* Check for ambiguous virtual bases. */
4550 vbases;
4552 {
4558 }
4559 }
4561 /* Compare two INTEGER_CSTs K1 and K2. */
4563 static int
4565 {
4567 }
4569 /* Increase the size indicated in RLI to account for empty classes
4570 that are "off the end" of the class. */
4572 static void
4574 {
4575 tree eoc;
4576 tree rli_size;
4578 /* It might be the case that we grew the class to allocate a
4579 zero-sized base class. That won't be reflected in RLI, yet,
4580 because we are willing to overlay multiple bases at the same
4581 offset. However, now we need to make sure that RLI is big enough
4582 to reflect the entire class. */
4588 {
4590 /* In version 1 of the ABI, the size of a class that ends with
4591 a bitfield was not rounded up to a whole multiple of a
4592 byte. Because rli_size_unit_so_far returns only the number
4593 of fully allocated bytes, any extra bits were not included
4594 in the size. */
4596 else
4597 /* The size should have been rounded to a whole byte. */
4600 BITS_PER_UNIT)),
4602 rli->bitpos
4611 }
4612 }
4614 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4615 BINFO_OFFSETs for all of the base-classes. Position the vtable
4616 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4618 static void
4620 {
4621 tree non_static_data_members;
4622 tree field;
4623 tree vptr;
4624 record_layout_info rli;
4625 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4626 types that appear at that offset. */
4627 splay_tree empty_base_offsets;
4628 /* True if the last field layed out was a bit-field. */
4630 /* The location at which the next field should be inserted. */
4632 /* T, as a base class. */
4633 tree base_t;
4635 /* Keep track of the first non-static data member. */
4638 /* Start laying out the record. */
4641 /* If possible, we reuse the virtual function table pointer from one
4642 of our base classes. */
4645 /* Create a pointer to our virtual function table. */
4648 /* The vptr is always the first thing in the class. */
4650 {
4655 }
4656 else
4659 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4664 /* Layout the non-static data members. */
4666 {
4667 tree type;
4668 tree padding;
4670 /* We still pass things that aren't non-static data members to
4671 the back-end, in case it wants to do something with them. */
4673 {
4675 /* If the static data member has incomplete type, keep track
4676 of it so that it can be completed later. (The handling
4677 of pending statics in finish_record_layout is
4678 insufficient; consider:
4680 struct S1;
4681 struct S2 { static S1 s1; };
4683 At this point, finish_record_layout will be called, but
4684 S1 is still incomplete.) */
4688 }
4694 /* If this field is a bit-field whose width is greater than its
4695 type, then there are some special rules for allocating
4696 it. */
4699 {
4700 integer_type_kind itk;
4701 tree integer_type;
4703 /* We must allocate the bits as if suitably aligned for the
4704 longest integer type that fits in this many bits. type
4705 of the field. Then, we are supposed to use the left over
4706 bits as additional padding. */
4712 /* ITK now indicates a type that is too large for the
4713 field. We have to back up by one to find the largest
4714 type that fits. */
4717 /* Figure out how much additional padding is required. GCC
4718 3.2 always created a padding field, even if it had zero
4719 width. */
4722 {
4724 /* In a union, the padding field must have the full width
4725 of the bit-field; all fields start at offset zero. */
4727 else
4728 {
4731 "ABI-compliant and may change in a future "
4733 t);
4736 }
4737 }
4738 #ifdef PCC_BITFIELD_TYPE_MATTERS
4739 /* An unnamed bitfield does not normally affect the
4740 alignment of the containing class on a target where
4741 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4742 make any exceptions for unnamed bitfields when the
4743 bitfields are longer than their types. Therefore, we
4744 temporarily give the field a name. */
4746 {
4749 }
4750 #endif
4755 empty_base_offsets);
4758 /* Now that layout has been performed, set the size of the
4759 field to the size of its declared type; the rest of the
4760 field is effectively invisible. */
4762 }
4763 else
4765 empty_base_offsets);
4767 /* Remember the location of any empty classes in FIELD. */
4771 empty_base_offsets,
4774 /* If a bit-field does not immediately follow another bit-field,
4775 and yet it starts in the middle of a byte, we have failed to
4776 comply with the ABI. */
4779 && !last_field_was_bitfield
4782 bitsize_unit_node)))
4783 cp_warning_at ("offset of `%D' is not ABI-compliant and may change in a future version of GCC",
4784 field);
4786 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4787 offset of the field. */
4793 "classes to be placed at different locations in a "
4795 field);
4797 /* If we needed additional padding after this field, add it
4798 now. */
4800 {
4801 tree padding_field;
4804 NULL_TREE,
4805 char_type_node);
4810 NULL_TREE,
4811 empty_base_offsets);
4812 }
4815 }
4818 {
4819 /* Make sure that we are on a byte boundary so that the size of
4820 the class without virtual bases will always be a round number
4821 of bytes. */
4824 }
4826 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4827 padding. */
4831 /* Delete all zero-width bit-fields from the list of fields. Now
4832 that the type is laid out they are no longer important. */
4835 /* Create the version of T used for virtual bases. We do not use
4836 make_aggr_type for this version; this is an artificial type. For
4837 a POD type, we just reuse T. */
4839 {
4842 /* Set the size and alignment for the new type. In G++ 3.2, all
4843 empty classes were considered to have size zero when used as
4844 base classes. */
4846 {
4852 t);
4853 }
4854 else
4855 {
4856 tree eoc;
4858 /* If the ABI version is not at least two, and the last
4859 field was a bit-field, RLI may not be on a byte
4860 boundary. In particular, rli_size_unit_so_far might
4861 indicate the last complete byte, while rli_size_so_far
4862 indicates the total number of bits used. Therefore,
4863 rli_size_so_far, rather than rli_size_unit_so_far, is
4864 used to compute TYPE_SIZE_UNIT. */
4872 eoc);
4879 }
4883 /* Copy the fields from T. */
4887 {
4896 }
4898 /* Record the base version of the type. */
4901 }
4902 else
4905 /* Every empty class contains an empty class. */
4909 /* Set the TYPE_DECL for this type to contain the right
4910 value for DECL_OFFSET, so that we can use it as part
4911 of a COMPONENT_REF for multiple inheritance. */
4914 /* Now fix up any virtual base class types that we left lying
4915 around. We must get these done before we try to lay out the
4916 virtual function table. As a side-effect, this will remove the
4917 base subobject fields. */
4920 /* Make sure that empty classes are reflected in RLI at this
4921 point. */
4924 /* Make sure not to create any structures with zero size. */
4929 /* Let the back-end lay out the type. */
4932 /* Warn about bases that can't be talked about due to ambiguity. */
4935 /* Clean up. */
4937 }
4939 /* Returns the virtual function with which the vtable for TYPE is
4940 emitted, or NULL_TREE if that heuristic is not applicable to TYPE. */
4942 static tree
4944 {
4945 tree method;
4948 || processing_template_decl
4961 }
4963 /* Perform processing required when the definition of T (a class type)
4964 is complete. */
4966 void
4968 {
4969 tree x;
4970 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
4973 tree vfield;
4976 {
4979 else
4983 }
4985 /* If this type was previously laid out as a forward reference,
4986 make sure we lay it out again. */
4992 /* Make assumptions about the class; we'll reset the flags if
4993 necessary. */
4998 /* Do end-of-class semantic processing: checking the validity of the
4999 bases and members and add implicitly generated methods. */
5002 /* Find the key method */
5004 {
5007 /* If a polymorphic class has no key method, we may emit the vtable
5008 in every translation unit where the class definition appears. */
5011 }
5013 /* Layout the class itself. */
5016 /* Make sure that we get our own copy of the vfield FIELD_DECL. */
5019 {
5025 /* The vtable better be at the start. */
5034 }
5035 else
5040 /* If we created a new vtbl pointer for this class, add it to the
5041 list. */
5046 /* If necessary, create the primary vtable for this class. */
5048 {
5049 /* We must enter these virtuals into the table. */
5053 /* Here we know enough to change the type of our virtual
5054 function table, but we will wait until later this function. */
5056 }
5059 {
5061 tree fn;
5070 /* Add entries for virtual functions introduced by this class. */
5073 /* Set DECL_VINDEX for all functions declared in this class. */
5075 fn;
5077 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5079 {
5083 /* A thunk. We should never be calling this entry directly
5084 from this vtable -- we'd use the entry for the non
5085 thunk base function. */
5089 }
5090 }
5094 /* Complete the rtl for any static member objects of the type we're
5095 working on. */
5101 /* Done with FIELDS...now decide whether to sort these for
5102 faster lookups later.
5104 We use a small number because most searches fail (succeeding
5105 ultimately as the search bores through the inheritance
5106 hierarchy), and we want this failure to occur quickly. */
5110 {
5116 field_decl_cmp);
5120 }
5123 {
5128 /* Mark the fact that constructor for T could affect anybody
5129 inheriting from T who wants to initialize vtables for
5130 VFIELDS's type. */
5133 }
5135 /* Make the rtl for any new vtables we have created, and unmark
5136 the base types we marked. */
5139 /* Build the VTT for T. */
5155 /* Finish debugging output for this type. */
5157 }
5159 /* When T was built up, the member declarations were added in reverse
5160 order. Rearrange them to declaration order. */
5162 void
5164 {
5165 tree next;
5166 tree prev;
5167 tree x;
5169 /* The following lists are all in reverse order. Put them in
5170 declaration order now. */
5174 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5175 reverse order, so we can't just use nreverse. */
5180 {
5184 }
5186 {
5190 }
5191 }
5193 tree
5195 {
5198 /* Now that we've got all the field declarations, reverse everything
5199 as necessary. */
5204 /* Nadger the current location so that diagnostics point to the start of
5205 the struct, not the end. */
5209 {
5212 }
5213 else
5222 else
5229 }
5230 \f
5231 /* Return the dynamic type of INSTANCE, if known.
5232 Used to determine whether the virtual function table is needed
5233 or not.
5235 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5236 of our knowledge of its type. *NONNULL should be initialized
5237 before this function is called. */
5239 static tree
5241 {
5243 {
5247 else
5252 /* This is a call to a constructor, hence it's never zero. */
5254 {
5258 }
5262 /* This is a call to a constructor, hence it's never zero. */
5264 {
5268 }
5279 /* Propagate nonnull. */
5299 {
5303 }
5304 /* fall through... */
5309 {
5313 }
5315 {
5319 /* if we're in a ctor or dtor, we know our type. */
5323 {
5327 }
5328 }
5330 {
5331 /* Reference variables should be references to objects. */
5335 /* DECL_VAR_MARKED_P is used to prevent recursion; a
5336 variable's initializer may refer to the variable
5337 itself. */
5341 {
5342 tree type;
5348 }
5349 }
5354 }
5355 }
5357 /* Return nonzero if the dynamic type of INSTANCE is known, and
5358 equivalent to the static type. We also handle the case where
5359 INSTANCE is really a pointer. Return negative if this is a
5360 ctor/dtor. There the dynamic type is known, but this might not be
5361 the most derived base of the original object, and hence virtual
5362 bases may not be layed out according to this type.
5364 Used to determine whether the virtual function table is needed
5365 or not.
5367 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5368 of our knowledge of its type. *NONNULL should be initialized
5369 before this function is called. */
5371 int
5373 {
5385 }
5387 \f
5388 void
5390 {
5393 current_class_stack
5400 }
5402 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5403 appropriate for TYPE.
5405 So that we may avoid calls to lookup_name, we cache the _TYPE
5406 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5408 For multiple inheritance, we perform a two-pass depth-first search
5409 of the type lattice. The first pass performs a pre-order search,
5410 marking types after the type has had its fields installed in
5411 the appropriate IDENTIFIER_CLASS_VALUE slot. The second pass merely
5412 unmarks the marked types. If a field or member function name
5413 appears in an ambiguous way, the IDENTIFIER_CLASS_VALUE of
5414 that name becomes `error_mark_node'. */
5416 void
5418 {
5421 /* Make sure there is enough room for the new entry on the stack. */
5423 {
5425 current_class_stack
5427 current_class_stack_size
5429 }
5431 /* Insert a new entry on the class stack. */
5436 current_class_depth++;
5438 /* Now set up the new type. */
5444 /* By default, things in classes are private, while things in
5445 structures or unions are public. */
5447 ? access_private_node
5454 {
5455 /* Forcibly remove any old class remnants. */
5457 }
5459 /* If we're about to enter a nested class, clear
5460 IDENTIFIER_CLASS_VALUE for the enclosing classes. */
5467 {
5470 {
5471 /* If we are entering the scope of a template declaration (not a
5472 specialization), we need to push all the using decls with
5473 dependent scope too. */
5474 tree fields;
5480 }
5481 }
5482 else
5483 {
5484 tree item;
5486 /* We are re-entering the same class we just left, so we don't
5487 have to search the whole inheritance matrix to find all the
5488 decls to bind again. Instead, we install the cached
5489 class_shadowed list, and walk through it binding names and
5490 setting up IDENTIFIER_TYPE_VALUEs. */
5493 {
5500 }
5502 }
5505 }
5507 /* When we exit a toplevel class scope, we save the
5508 IDENTIFIER_CLASS_VALUEs so that we can restore them quickly if we
5509 reenter the class. Here, we've entered some other class, so we
5510 must invalidate our cache. */
5512 void
5514 {
5515 tree t;
5517 /* The IDENTIFIER_CLASS_VALUEs are no longer valid. */
5523 }
5525 /* Get out of the current class scope. If we were in a class scope
5526 previously, that is the one popped to. */
5528 void
5530 {
5534 current_class_depth--;
5540 }
5542 /* Returns 1 if current_class_type is either T or a nested type of T.
5543 We start looking from 1 because entry 0 is from global scope, and has
5544 no type. */
5546 int
5548 {
5557 }
5559 /* If either current_class_type or one of its enclosing classes are derived
5560 from T, return the appropriate type. Used to determine how we found
5561 something via unqualified lookup. */
5563 tree
5565 {
5568 /* The bases of a dependent type are unknown. */
5580 }
5582 /* When entering a class scope, all enclosing class scopes' names with
5583 static meaning (static variables, static functions, types and
5584 enumerators) have to be visible. This recursive function calls
5585 pushclass for all enclosing class contexts until global or a local
5586 scope is reached. TYPE is the enclosed class. */
5588 void
5590 {
5591 tree context;
5593 /* A namespace might be passed in error cases, like A::B:C. */
5607 }
5609 /* Undoes a push_nested_class call. */
5611 void
5613 {
5619 }
5621 /* Returns the number of extern "LANG" blocks we are nested within. */
5623 int
5625 {
5627 }
5629 /* Set global variables CURRENT_LANG_NAME to appropriate value
5630 so that behavior of name-mangling machinery is correct. */
5632 void
5634 {
5638 {
5640 }
5642 {
5644 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5645 (See record_builtin_java_type in decl.c.) However, that causes
5646 incorrect debug entries if these types are actually used.
5647 So we re-enable debug output after extern "Java". */
5656 }
5658 {
5660 }
5661 else
5663 }
5665 /* Get out of the current language scope. */
5667 void
5669 {
5672 }
5673 \f
5674 /* Type instantiation routines. */
5676 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5677 matches the TARGET_TYPE. If there is no satisfactory match, return
5678 error_mark_node, and issue an error message if COMPLAIN is
5679 nonzero. Permit pointers to member function if PTRMEM is nonzero.
5680 If TEMPLATE_ONLY, the name of the overloaded function
5681 was a template-id, and EXPLICIT_TARGS are the explicitly provided
5682 template arguments. */
5684 static tree
5686 tree overload,
5690 tree explicit_targs)
5691 {
5692 /* Here's what the standard says:
5694 [over.over]
5696 If the name is a function template, template argument deduction
5697 is done, and if the argument deduction succeeds, the deduced
5698 arguments are used to generate a single template function, which
5699 is added to the set of overloaded functions considered.
5701 Non-member functions and static member functions match targets of
5702 type "pointer-to-function" or "reference-to-function." Nonstatic
5703 member functions match targets of type "pointer-to-member
5704 function;" the function type of the pointer to member is used to
5705 select the member function from the set of overloaded member
5706 functions. If a nonstatic member function is selected, the
5707 reference to the overloaded function name is required to have the
5708 form of a pointer to member as described in 5.3.1.
5710 If more than one function is selected, any template functions in
5711 the set are eliminated if the set also contains a non-template
5712 function, and any given template function is eliminated if the
5713 set contains a second template function that is more specialized
5714 than the first according to the partial ordering rules 14.5.5.2.
5715 After such eliminations, if any, there shall remain exactly one
5716 selected function. */
5720 /* We store the matches in a TREE_LIST rooted here. The functions
5721 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5722 interoperability with most_specialized_instantiation. */
5724 tree fn;
5726 /* By the time we get here, we should be seeing only real
5727 pointer-to-member types, not the internal POINTER_TYPE to
5728 METHOD_TYPE representation. */
5736 /* Check that the TARGET_TYPE is reasonable. */
5740 /* This is OK, too. */
5743 {
5744 /* This is OK, too. This comes from a conversion to reference
5745 type. */
5748 }
5749 else
5750 {
5756 }
5758 /* If we can find a non-template function that matches, we can just
5759 use it. There's no point in generating template instantiations
5760 if we're just going to throw them out anyhow. But, of course, we
5761 can only do this when we don't *need* a template function. */
5763 {
5764 tree fns;
5767 {
5769 tree fntype;
5772 /* We're not looking for templates just yet. */
5777 /* We're looking for a non-static member, and this isn't
5778 one, or vice versa. */
5781 /* Ignore anticipated decls of undeclared builtins. */
5785 /* See if there's a match. */
5794 }
5795 }
5797 /* Now, if we've already got a match (or matches), there's no need
5798 to proceed to the template functions. But, if we don't have a
5799 match we need to look at them, too. */
5801 {
5802 tree target_fn_type;
5803 tree target_arg_types;
5804 tree target_ret_type;
5805 tree fns;
5808 target_fn_type
5810 else
5815 /* Never do unification on the 'this' parameter. */
5820 {
5822 tree instantiation;
5823 tree instantiation_type;
5824 tree targs;
5827 /* We're only looking for templates. */
5832 /* We're not looking for a non-static member, and this is
5833 one, or vice versa. */
5836 /* Try to do argument deduction. */
5841 /* Argument deduction failed. */
5844 /* Instantiate the template. */
5848 /* Instantiation failed. */
5851 /* See if there's a match. */
5854 instantiation_type =
5860 }
5862 /* Now, remove all but the most specialized of the matches. */
5864 {
5869 }
5870 }
5872 /* Now we should have exactly one function in MATCHES. */
5874 {
5875 /* There were *no* matches. */
5877 {
5880 target_type);
5882 /* print_candidates expects a chain with the functions in
5883 TREE_VALUE slots, so we cons one up here (we're losing anyway,
5884 so why be clever?). */
5887 matches);
5890 }
5892 }
5894 {
5895 /* There were too many matches. */
5898 {
5899 tree match;
5903 target_type);
5905 /* Since print_candidates expects the functions in the
5906 TREE_VALUE slot, we flip them here. */
5911 }
5914 }
5916 /* Good, exactly one match. Now, convert it to the correct type. */
5921 {
5929 {
5932 }
5933 }
5938 else
5939 {
5940 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
5941 will mark the function as addressed, but here we must do it
5942 explicitly. */
5946 }
5947 }
5949 /* This function will instantiate the type of the expression given in
5950 RHS to match the type of LHSTYPE. If errors exist, then return
5951 error_mark_node. FLAGS is a bit mask. If ITF_COMPLAIN is set, then
5952 we complain on errors. If we are not complaining, never modify rhs,
5953 as overload resolution wants to try many possible instantiations, in
5954 the hope that at least one will work.
5956 For non-recursive calls, LHSTYPE should be a function, pointer to
5957 function, or a pointer to member function. */
5959 tree
5961 {
5968 {
5972 }
5975 {
5981 /* Microsoft allows `A::f' to be resolved to a
5982 pointer-to-member. */
5983 ;
5984 else
5985 {
5990 }
5991 }
5996 /* We don't overwrite rhs if it is an overloaded function.
5997 Copying it would destroy the tree link. */
6001 /* This should really only be used when attempting to distinguish
6002 what sort of a pointer to function we have. For now, any
6003 arithmetic operation which is not supported on pointers
6004 is rejected as an error. */
6007 {
6018 {
6019 tree new_rhs;
6029 }
6045 /* This can happen if we are forming a pointer-to-member for a
6046 member template. */
6049 /* Fall through. */
6052 {
6056 return
6058 fns,
6059 complain,
6060 allow_ptrmem,
6062 args);
6063 }
6067 return
6069 rhs,
6070 complain,
6071 allow_ptrmem,
6076 /* Now we should have a baselink. */
6082 /* This is too hard for now. */
6156 {
6160 }
6183 {
6188 }
6199 }
6200 }
6201 \f
6202 /* Return the name of the virtual function pointer field
6203 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6204 this may have to look back through base types to find the
6205 ultimate field name. (For single inheritance, these could
6206 all be the same name. Who knows for multiple inheritance). */
6208 static tree
6210 {
6224 }
6226 void
6228 {
6229 #ifdef GATHER_STATISTICS
6235 {
6240 }
6241 #endif
6242 }
6244 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6245 according to [class]:
6246 The class-name is also inserted
6247 into the scope of the class itself. For purposes of access checking,
6248 the inserted class name is treated as if it were a public member name. */
6250 void
6252 {
6255 tree saved_cas;
6269 }
6271 /* Returns 1 if TYPE contains only padding bytes. */
6273 int
6275 {
6282 /* In G++ 3.2, whether or not a class was empty was determined by
6283 looking at its size. */
6286 else
6288 }
6290 /* Returns true if TYPE contains an empty class. */
6292 static bool
6294 {
6298 {
6299 tree field;
6310 }
6314 }
6316 /* Find the enclosing class of the given NODE. NODE can be a *_DECL or
6317 a *_TYPE node. NODE can also be a local class. */
6319 tree
6321 {
6325 {
6327 {
6340 }
6341 }
6343 }
6345 /* Note that NAME was looked up while the current class was being
6346 defined and that the result of that lookup was DECL. */
6348 void
6350 {
6351 splay_tree names_used;
6353 /* If we're not defining a class, there's nothing to do. */
6357 /* If there's already a binding for this NAME, then we don't have
6358 anything to worry about. */
6370 }
6372 /* Note that NAME was declared (as DECL) in the current class. Check
6373 to see that the declaration is valid. */
6375 void
6377 {
6378 splay_tree names_used;
6379 splay_tree_node n;
6381 /* Look to see if we ever used this name. */
6382 names_used
6389 {
6390 /* [basic.scope.class]
6392 A name N used in a class S shall refer to the same declaration
6393 in its context and when re-evaluated in the completed scope of
6394 S. */
6399 }
6400 }
6402 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6403 Secondary vtables are merged with primary vtables; this function
6404 will return the VAR_DECL for the primary vtable. */
6406 tree
6408 {
6409 tree decl;
6413 {
6417 }
6421 }
6424 /* Returns the binfo for the primary base of BINFO. If the resulting
6425 BINFO is a virtual base, and it is inherited elsewhere in the
6426 hierarchy, then the returned binfo might not be the primary base of
6427 BINFO in the complete object. Check BINFO_PRIMARY_P or
6428 BINFO_LOST_PRIMARY_P to be sure. */
6430 tree
6432 {
6433 tree primary_base;
6434 tree result;
6442 }
6444 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6446 static int
6448 {
6452 }
6454 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6455 INDENT should be zero when called from the top level; it is
6456 incremented recursively. IGO indicates the next expected BINFO in
6457 inheritance graph ordering. */
6459 static tree
6462 tree binfo,
6463 tree igo,
6465 {
6467 tree base_binfos;
6474 {
6477 }
6492 {
6496 TFF_PLAIN_IDENTIFIER),
6498 }
6500 {
6503 }
6508 {
6512 {
6516 TFF_PLAIN_IDENTIFIER));
6517 }
6519 {
6523 TFF_PLAIN_IDENTIFIER));
6524 }
6526 {
6530 TFF_PLAIN_IDENTIFIER));
6531 }
6533 {
6537 TFF_PLAIN_IDENTIFIER));
6538 }
6542 }
6546 {
6551 {
6556 }
6557 }
6560 }
6562 /* Dump the BINFO hierarchy for T. */
6564 static void
6566 {
6585 }
6587 static void
6589 {
6590 tree inits;
6592 HOST_WIDE_INT elt;
6600 TFF_PLAIN_IDENTIFIER));
6607 }
6609 static void
6611 {
6619 {
6626 {
6630 }
6634 }
6637 }
6639 static void
6641 {
6649 {
6654 }
6657 }
6659 /* Virtual function table initialization. */
6661 /* Create all the necessary vtables for T and its base classes. */
6663 static void
6665 {
6666 tree list;
6667 tree vbase;
6669 /* We lay out the primary and secondary vtables in one contiguous
6670 vtable. The primary vtable is first, followed by the non-virtual
6671 secondary vtables in inheritance graph order. */
6676 /* Then come the virtual bases, also in inheritance graph order. */
6678 {
6682 }
6686 }
6688 /* Initialize the vtable for BINFO with the INITS. */
6690 static void
6692 {
6693 tree decl;
6699 }
6701 /* Initialize DECL (a declaration for a namespace-scope array) with
6702 the INITS. */
6704 static void
6706 {
6707 tree context;
6715 }
6717 /* Build the VTT (virtual table table) for T.
6718 A class requires a VTT if it has virtual bases.
6720 This holds
6721 1 - primary virtual pointer for complete object T
6722 2 - secondary VTTs for each direct non-virtual base of T which requires a
6723 VTT
6724 3 - secondary virtual pointers for each direct or indirect base of T which
6725 has virtual bases or is reachable via a virtual path from T.
6726 4 - secondary VTTs for each direct or indirect virtual base of T.
6728 Secondary VTTs look like complete object VTTs without part 4. */
6730 static void
6732 {
6733 tree inits;
6734 tree type;
6735 tree vtt;
6736 tree index;
6738 /* Build up the initializers for the VTT. */
6743 /* If we didn't need a VTT, we're done. */
6747 /* Figure out the type of the VTT. */
6751 /* Now, build the VTT object itself. */
6754 /* Add the VTT to the vtables list. */
6759 }
6761 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6762 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6763 and CHAIN the vtable pointer for this binfo after construction is
6764 complete. VALUE can also be another BINFO, in which case we recurse. */
6766 static tree
6768 {
6769 tree vt;
6772 {
6778 else
6780 }
6783 }
6785 /* Recursively build the VTT-initializer for BINFO (which is in the
6786 hierarchy dominated by T). INITS points to the end of the initializer
6787 list to date. INDEX is the VTT index where the next element will be
6788 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6789 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
6790 for virtual bases of T. When it is not so, we build the constructor
6791 vtables for the BINFO-in-T variant. */
6795 {
6797 tree b;
6798 tree init;
6799 tree secondary_vptrs;
6802 /* We only need VTTs for subobjects with virtual bases. */
6806 /* We need to use a construction vtable if this is not the primary
6807 VTT. */
6809 {
6812 /* Record the offset in the VTT where this sub-VTT can be found. */
6814 }
6816 /* Add the address of the primary vtable for the complete object. */
6821 {
6824 }
6827 /* Recursively add the secondary VTTs for non-virtual bases. */
6829 {
6834 }
6836 /* Add secondary virtual pointers for all subobjects of BINFO with
6837 either virtual bases or reachable along a virtual path, except
6838 subobjects that are non-virtual primary bases. */
6845 dfs_build_secondary_vptr_vtt_inits,
6846 NULL,
6847 dfs_ctor_vtable_bases_queue_p,
6848 secondary_vptrs);
6851 secondary_vptrs);
6855 /* The secondary vptrs come back in reverse order. After we reverse
6856 them, and add the INITS, the last init will be the first element
6857 of the chain. */
6860 {
6864 }
6866 /* Add the secondary VTTs for virtual bases. */
6869 {
6874 }
6877 {
6883 dfs_ctor_vtable_bases_queue_p,
6884 data);
6885 }
6888 }
6890 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo
6891 for the base in most derived. DATA is a TREE_LIST who's
6892 TREE_CHAIN is the type of the base being
6893 constructed whilst this secondary vptr is live. The TREE_UNSIGNED
6894 flag of DATA indicates that this is a constructor vtable. The
6895 TREE_TOP_LEVEL flag indicates that this is the primary VTT. */
6897 static tree
6899 {
6900 tree l;
6901 tree t;
6902 tree init;
6903 tree index;
6912 /* We don't care about bases that don't have vtables. */
6916 /* We're only interested in proper subobjects of T. */
6920 /* We're not interested in non-virtual primary bases. */
6924 /* If BINFO has virtual bases or is reachable via a virtual path
6925 from T, it'll have a secondary vptr. */
6930 /* Record the index where this secondary vptr can be found. */
6933 {
6936 }
6940 /* Add the initializer for the secondary vptr itself. */
6942 {
6943 /* It's a primary virtual base, and this is not the construction
6944 vtable. Find the base this is primary of in the inheritance graph,
6945 and use that base's vtable now. */
6948 }
6953 }
6955 /* dfs_walk_real predicate for building vtables. DATA is a TREE_LIST,
6956 VTT_MARKED_BINFO_P indicates whether marked or unmarked bases
6957 should be walked. TREE_PURPOSE is the TREE_TYPE that dominates the
6958 hierarchy. */
6960 static tree
6963 {
6969 }
6971 /* Called from build_vtt_inits via dfs_walk. After building constructor
6972 vtables and generating the sub-vtt from them, we need to restore the
6973 BINFO_VTABLES that were scribbled on. DATA is a TREE_LIST whose
6974 TREE_VALUE is the TREE_TYPE of the base whose sub vtt was generated. */
6976 static tree
6978 {
6981 /* We don't care about bases that don't have vtables. */
6985 /* If we scribbled the construction vtable vptr into BINFO, clear it
6986 out now. */
6994 }
6996 /* Build the construction vtable group for BINFO which is in the
6997 hierarchy dominated by T. */
6999 static void
7001 {
7002 tree list;
7003 tree type;
7004 tree vtbl;
7005 tree inits;
7006 tree id;
7007 tree vbase;
7009 /* See if we've already created this construction vtable group. */
7015 /* Build a version of VTBL (with the wrong type) for use in
7016 constructing the addresses of secondary vtables in the
7017 construction vtable group. */
7023 /* Add the vtables for each of our virtual bases using the vbase in T
7024 binfo. */
7026 vbase;
7028 {
7029 tree b;
7036 }
7039 /* Figure out the type of the construction vtable. */
7044 /* Initialize the construction vtable. */
7048 }
7050 /* Add the vtbl initializers for BINFO (and its bases other than
7051 non-virtual primaries) to the list of INITS. BINFO is in the
7052 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7053 the constructor the vtbl inits should be accumulated for. (If this
7054 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7055 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7056 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7057 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7058 but are not necessarily the same in terms of layout. */
7060 static void
7062 tree orig_binfo,
7063 tree rtti_binfo,
7064 tree t,
7065 tree inits)
7066 {
7074 /* If it doesn't have a vptr, we don't do anything. */
7078 /* If we're building a construction vtable, we're not interested in
7079 subobjects that don't require construction vtables. */
7085 /* Build the initializers for the BINFO-in-T vtable. */
7091 /* Walk the BINFO and its bases. We walk in preorder so that as we
7092 initialize each vtable we can figure out at what offset the
7093 secondary vtable lies from the primary vtable. We can't use
7094 dfs_walk here because we need to iterate through bases of BINFO
7095 and RTTI_BINFO simultaneously. */
7097 {
7100 /* Skip virtual bases. */
7106 inits);
7107 }
7108 }
7110 /* Called from accumulate_vtbl_inits. Returns the initializers for
7111 the BINFO vtable. */
7113 static tree
7115 tree orig_binfo,
7116 tree rtti_binfo,
7117 tree t,
7118 tree l)
7119 {
7126 {
7127 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7128 primary virtual base. If it is not the same primary in
7129 the hierarchy of T, we'll need to generate a ctor vtable
7130 for it, to place at its location in T. If it is the same
7131 primary, we still need a VTT entry for the vtable, but it
7132 should point to the ctor vtable for the base it is a
7133 primary for within the sub-hierarchy of RTTI_BINFO.
7135 There are three possible cases:
7137 1) We are in the same place.
7138 2) We are a primary base within a lost primary virtual base of
7139 RTTI_BINFO.
7140 3) We are primary to something not a base of RTTI_BINFO. */
7145 /* First, look through the bases we are primary to for RTTI_BINFO
7146 or a virtual base. */
7148 {
7152 }
7153 /* If we run out of primary links, keep looking down our
7154 inheritance chain; we might be an indirect primary. */
7160 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7161 base B and it is a base of RTTI_BINFO, this is case 2. In
7162 either case, we share our vtable with LAST, i.e. the
7163 derived-most base within B of which we are a primary. */
7167 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7168 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7169 binfo_ctor_vtable after everything's been set up. */
7172 /* Otherwise, this is case 3 and we get our own. */
7173 }
7178 {
7179 tree index;
7182 /* Compute the initializer for this vtable. */
7186 /* Figure out the position to which the VPTR should point. */
7189 vtbl_ptr_type_node,
7190 vtbl);
7197 index);
7200 }
7203 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7204 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7205 straighten this out. */
7209 else
7210 /* For an ordinary vtable, set BINFO_VTABLE. */
7214 }
7216 /* Construct the initializer for BINFO's virtual function table. BINFO
7217 is part of the hierarchy dominated by T. If we're building a
7218 construction vtable, the ORIG_BINFO is the binfo we should use to
7219 find the actual function pointers to put in the vtable - but they
7220 can be overridden on the path to most-derived in the graph that
7221 ORIG_BINFO belongs. Otherwise,
7222 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7223 BINFO that should be indicated by the RTTI information in the
7224 vtable; it will be a base class of T, rather than T itself, if we
7225 are building a construction vtable.
7227 The value returned is a TREE_LIST suitable for wrapping in a
7228 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7229 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7230 number of non-function entries in the vtable.
7232 It might seem that this function should never be called with a
7233 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7234 base is always subsumed by a derived class vtable. However, when
7235 we are building construction vtables, we do build vtables for
7236 primary bases; we need these while the primary base is being
7237 constructed. */
7239 static tree
7241 tree orig_binfo,
7242 tree t,
7243 tree rtti_binfo,
7245 {
7247 tree vfun_inits;
7248 tree vbase;
7249 vtbl_init_data vid;
7251 /* Initialize VID. */
7260 /* The first vbase or vcall offset is at index -3 in the vtable. */
7263 /* Add entries to the vtable for RTTI. */
7266 /* Create an array for keeping track of the functions we've
7267 processed. When we see multiple functions with the same
7268 signature, we share the vcall offsets. */
7270 /* Add the vcall and vbase offset entries. */
7272 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7273 build_vbase_offset_vtbl_entries. */
7275 vbase;
7279 /* If the target requires padding between data entries, add that now. */
7281 {
7285 {
7292 null_pointer_node),
7293 add);
7295 }
7296 }
7301 /* Go through all the ordinary virtual functions, building up
7302 initializers. */
7305 {
7306 tree delta;
7307 tree vcall_index;
7314 {
7318 }
7320 /* If the only definition of this function signature along our
7321 primary base chain is from a lost primary, this vtable slot will
7322 never be used, so just zero it out. This is important to avoid
7323 requiring extra thunks which cannot be generated with the function.
7325 We first check this in update_vtable_entry_for_fn, so we handle
7326 restored primary bases properly; we also need to do it here so we
7327 zero out unused slots in ctor vtables, rather than filling themff
7328 with erroneous values (though harmless, apart from relocation
7329 costs). */
7331 {
7332 /* We found a defn before a lost primary; go ahead as normal. */
7336 /* The nearest definition is from a lost primary; clear the
7337 slot. */
7339 {
7342 }
7343 }
7346 {
7347 /* Pull the offset for `this', and the function to call, out of
7348 the list. */
7355 /* You can't call an abstract virtual function; it's abstract.
7356 So, we replace these functions with __pure_virtual. */
7360 {
7364 }
7365 /* Take the address of the function, considering it to be of an
7366 appropriate generic type. */
7368 /* The address of a function can't change. */
7370 }
7372 /* And add it to the chain of initializers. */
7374 {
7379 else
7381 {
7388 }
7389 }
7390 else
7392 }
7394 /* The initializers for virtual functions were built up in reverse
7395 order; straighten them out now. */
7398 /* The negative offset initializers are also in reverse order. */
7401 /* Chain the two together. */
7403 }
7405 /* Adds to vid->inits the initializers for the vbase and vcall
7406 offsets in BINFO, which is in the hierarchy dominated by T. */
7408 static void
7410 {
7411 tree b;
7413 /* If this is a derived class, we must first create entries
7414 corresponding to the primary base class. */
7419 /* Add the vbase entries for this base. */
7421 /* Add the vcall entries for this base. */
7423 }
7425 /* Returns the initializers for the vbase offset entries in the vtable
7426 for BINFO (which is part of the class hierarchy dominated by T), in
7427 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7428 where the next vbase offset will go. */
7430 static void
7432 {
7433 tree vbase;
7434 tree t;
7435 tree non_primary_binfo;
7437 /* If there are no virtual baseclasses, then there is nothing to
7438 do. */
7444 /* We might be a primary base class. Go up the inheritance hierarchy
7445 until we find the most derived class of which we are a primary base:
7446 it is the offset of that which we need to use. */
7449 {
7450 tree b;
7452 /* If we have reached a virtual base, then it must be a primary
7453 base (possibly multi-level) of vid->binfo, or we wouldn't
7454 have called build_vcall_and_vbase_vtbl_entries for it. But it
7455 might be a lost primary, so just skip down to vid->binfo. */
7457 {
7460 }
7466 }
7468 /* Go through the virtual bases, adding the offsets. */
7470 vbase;
7472 {
7473 tree b;
7474 tree delta;
7479 /* Find the instance of this virtual base in the complete
7480 object. */
7483 /* If we've already got an offset for this virtual base, we
7484 don't need another one. */
7489 /* Figure out where we can find this vbase offset. */
7498 {
7499 /* The vbase offset had better be the same. */
7503 }
7505 /* The next vbase will come at a more negative offset. */
7509 /* The initializer is the delta from BINFO to this virtual base.
7510 The vbase offsets go in reverse inheritance-graph order, and
7511 we are walking in inheritance graph order so these end up in
7512 the right order. */
7518 vtable_entry_type,
7519 delta)));
7521 }
7522 }
7524 /* Adds the initializers for the vcall offset entries in the vtable
7525 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7526 to VID->INITS. */
7528 static void
7530 {
7531 /* We only need these entries if this base is a virtual base. We
7532 compute the indices -- but do not add to the vtable -- when
7533 building the main vtable for a class. */
7535 {
7536 /* We need a vcall offset for each of the virtual functions in this
7537 vtable. For example:
7539 class A { virtual void f (); };
7540 class B1 : virtual public A { virtual void f (); };
7541 class B2 : virtual public A { virtual void f (); };
7542 class C: public B1, public B2 { virtual void f (); };
7544 A C object has a primary base of B1, which has a primary base of A. A
7545 C also has a secondary base of B2, which no longer has a primary base
7546 of A. So the B2-in-C construction vtable needs a secondary vtable for
7547 A, which will adjust the A* to a B2* to call f. We have no way of
7548 knowing what (or even whether) this offset will be when we define B2,
7549 so we store this "vcall offset" in the A sub-vtable and look it up in
7550 a "virtual thunk" for B2::f.
7552 We need entries for all the functions in our primary vtable and
7553 in our non-virtual bases' secondary vtables. */
7555 /* If we are just computing the vcall indices -- but do not need
7556 the actual entries -- not that. */
7559 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7561 }
7562 }
7564 /* Build vcall offsets, starting with those for BINFO. */
7566 static void
7568 {
7570 tree primary_binfo;
7572 /* Don't walk into virtual bases -- except, of course, for the
7573 virtual base for which we are building vcall offsets. Any
7574 primary virtual base will have already had its offsets generated
7575 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7579 /* If BINFO has a primary base, process it first. */
7584 /* Add BINFO itself to the list. */
7587 /* Scan the non-primary bases of BINFO. */
7589 {
7590 tree base_binfo;
7595 }
7596 }
7598 /* Called from build_vcall_offset_vtbl_entries_r. */
7600 static void
7602 {
7603 /* Make entries for the rest of the virtuals. */
7605 {
7606 tree orig_fn;
7608 /* The ABI requires that the methods be processed in declaration
7609 order. G++ 3.2 used the order in the vtable. */
7611 orig_fn;
7615 }
7616 else
7617 {
7618 tree derived_virtuals;
7619 tree base_virtuals;
7620 tree orig_virtuals;
7621 /* If BINFO is a primary base, the most derived class which has
7622 BINFO as a primary base; otherwise, just BINFO. */
7623 tree non_primary_binfo;
7625 /* We might be a primary base class. Go up the inheritance hierarchy
7626 until we find the most derived class of which we are a primary base:
7627 it is the BINFO_VIRTUALS there that we need to consider. */
7630 {
7631 tree b;
7633 /* If we have reached a virtual base, then it must be vid->vbase,
7634 because we ignore other virtual bases in
7635 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7636 base (possibly multi-level) of vid->binfo, or we wouldn't
7637 have called build_vcall_and_vbase_vtbl_entries for it. But it
7638 might be a lost primary, so just skip down to vid->binfo. */
7640 {
7645 }
7651 }
7654 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7655 where rtti_binfo is the most derived type. */
7656 non_primary_binfo
7662 base_virtuals;
7666 {
7667 tree orig_fn;
7669 /* Find the declaration that originally caused this function to
7670 be present in BINFO_TYPE (binfo). */
7673 /* When processing BINFO, we only want to generate vcall slots for
7674 function slots introduced in BINFO. So don't try to generate
7675 one if the function isn't even defined in BINFO. */
7680 }
7681 }
7682 }
7684 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7686 static void
7688 {
7690 tree vcall_offset;
7692 /* If there is already an entry for a function with the same
7693 signature as FN, then we do not need a second vcall offset.
7694 Check the list of functions already present in the derived
7695 class vtable. */
7697 {
7698 tree derived_entry;
7702 /* We only use one vcall offset for virtual destructors,
7703 even though there are two virtual table entries. */
7707 }
7709 /* If we are building these vcall offsets as part of building
7710 the vtable for the most derived class, remember the vcall
7711 offset. */
7717 /* The next vcall offset will be found at a more negative
7718 offset. */
7722 /* Keep track of this function. */
7726 {
7727 tree base;
7728 tree fn;
7730 /* Find the overriding function. */
7734 integer_zero_node);
7735 else
7736 {
7739 /* The vbase we're working on is a primary base of
7740 vid->binfo. But it might be a lost primary, so its
7741 BINFO_OFFSET might be wrong, so we just use the
7742 BINFO_OFFSET from vid->binfo. */
7746 vcall_offset));
7747 }
7748 /* Add the initializer to the vtable. */
7751 }
7752 }
7754 /* Return vtbl initializers for the RTTI entries corresponding to the
7755 BINFO's vtable. The RTTI entries should indicate the object given
7756 by VID->rtti_binfo. */
7758 static void
7760 {
7761 tree b;
7762 tree t;
7763 tree basetype;
7764 tree offset;
7765 tree decl;
7766 tree init;
7771 /* To find the complete object, we will first convert to our most
7772 primary base, and then add the offset in the vtbl to that value. */
7776 {
7777 tree primary_base;
7782 }
7785 /* The second entry is the address of the typeinfo object. */
7788 else
7791 /* Convert the declaration to a type that can be stored in the
7792 vtable. */
7797 /* Add the offset-to-top entry. It comes earlier in the vtable that
7798 the the typeinfo entry. Convert the offset to look like a
7799 function pointer, so that we can put it in the vtable. */
7803 }