| blob | 01d4dd215ed6ac0085b7a9688c75d93722db7be1 |
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. */
39 /* The number of nested classes being processed. If we are not in the
40 scope of any class, this is zero. */
44 /* In order to deal with nested classes, we keep a stack of classes.
45 The topmost entry is the innermost class, and is the entry at index
46 CURRENT_CLASS_DEPTH */
49 /* The name of the class. */
50 tree name;
52 /* The _TYPE node for the class. */
53 tree type;
55 /* The access specifier pending for new declarations in the scope of
56 this class. */
57 tree access;
59 /* If were defining TYPE, the names used in this class. */
60 splay_tree names_used;
64 {
65 /* The base for which we're building initializers. */
66 tree binfo;
67 /* The type of the most-derived type. */
68 tree derived;
69 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
70 unless ctor_vtbl_p is true. */
71 tree rtti_binfo;
72 /* The negative-index vtable initializers built up so far. These
73 are in order from least negative index to most negative index. */
74 tree inits;
75 /* The last (i.e., most negative) entry in INITS. */
77 /* The binfo for the virtual base for which we're building
78 vcall offset initializers. */
79 tree vbase;
80 /* The functions in vbase for which we have already provided vcall
81 offsets. */
82 varray_type fns;
83 /* The vtable index of the next vcall or vbase offset. */
84 tree index;
85 /* Nonzero if we are building the initializer for the primary
86 vtable. */
88 /* Nonzero if we are building the initializer for a construction
89 vtable. */
91 /* True when adding vcall offset entries to the vtable. False when
92 merely computing the indices. */
96 /* The type of a function passed to walk_subobject_offsets. */
99 /* The stack itself. This is a dynamically resized array. The
100 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
104 /* An array of all local classes present in this translation unit, in
105 declaration order. */
106 varray_type local_classes;
183 tree);
186 vtbl_init_data *);
206 splay_tree_key k2);
215 /* Macros for dfs walking during vtt construction. See
216 dfs_ctor_vtable_bases_queue_p, dfs_build_secondary_vptr_vtt_inits
217 and dfs_fixup_binfo_vtbls. */
218 #define VTT_TOP_LEVEL_P(NODE) TREE_UNSIGNED (NODE)
219 #define VTT_MARKED_BINFO_P(NODE) TREE_USED (NODE)
221 /* Variables shared between class.c and call.c. */
223 #ifdef GATHER_STATISTICS
232 #endif
234 /* Convert to or from a base subobject. EXPR is an expression of type
235 `A' or `A*', an expression of type `B' or `B*' is returned. To
236 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
237 the B base instance within A. To convert base A to derived B, CODE
238 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
239 In this latter case, A must not be a morally virtual base of B.
240 NONNULL is true if EXPR is known to be non-NULL (this is only
241 needed when EXPR is of pointer type). CV qualifiers are preserved
242 from EXPR. */
244 tree
246 tree expr,
247 tree binfo,
249 {
252 tree probe;
253 tree offset;
254 tree target_type;
256 tree ptr_target_type;
264 {
268 }
281 {
285 }
288 /* This must happen before the call to save_expr. */
301 {
302 /* Going via virtual base V_BINFO. We need the static offset
303 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
304 V_BINFO. That offset is an entry in D_BINFO's vtable. */
305 tree v_offset;
308 {
309 /* In a base member initializer, we cannot rely on
310 the vtable being set up. We have to use the vtt_parm. */
318 v_offset);
320 }
321 else
329 v_offset);
340 /* Negative fixed_type_p means this is a constructor or destructor;
341 virtual base layout is fixed in in-charge [cd]tors, but not in
342 base [cd]tors. */
346 v_offset,
348 else
350 }
354 target_type = cp_build_qualified_type
364 else
373 expr);
376 }
378 /* Convert OBJECT to the base TYPE. If CHECK_ACCESS is true, an error
379 message is emitted if TYPE is inaccessible. OBJECT is assumed to
380 be non-NULL. */
382 tree
384 {
385 tree binfo;
389 NULL);
394 }
396 \f
397 /* Virtual function things. */
399 static tree
401 {
423 }
425 /* Given an object INSTANCE, return an expression which yields the
426 vtable element corresponding to INDEX. There are many special
427 cases for INSTANCE which we take care of here, mainly to avoid
428 creating extra tree nodes when we don't have to. */
430 static tree
432 {
433 tree aref;
436 /* Try to figure out what a reference refers to, and
437 access its virtual function table directly. */
447 {
452 }
463 }
465 tree
467 {
474 }
476 /* Given an object INSTANCE, return an expression which yields a
477 function pointer corresponding to vtable element INDEX. */
479 tree
481 {
484 /* When using function descriptors, the address of the
485 vtable entry is treated as a function pointer. */
494 }
496 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
497 for the given TYPE. */
499 static tree
501 {
503 }
505 /* Return an IDENTIFIER_NODE for the name of the virtual table table
506 for TYPE. */
508 tree
510 {
512 }
514 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
515 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
516 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
518 static tree
520 {
521 tree decl;
524 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
525 now to avoid confusion in mangle_decl. */
537 }
539 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
540 or even complete. If this does not exist, create it. If COMPLETE is
541 nonzero, then complete the definition of it -- that will render it
542 impossible to actually build the vtable, but is useful to get at those
543 which are known to exist in the runtime. */
545 tree
547 {
548 tree decl;
556 /* At one time the vtable info was grabbed 2 words at a time. This
557 fails on sparc unless you have 8-byte alignment. (tiemann) */
562 {
565 }
568 }
570 /* Returns a copy of the BINFO_VIRTUALS list in BINFO. The
571 BV_VCALL_INDEX for each entry is cleared. */
573 static tree
575 {
576 tree copies;
577 tree t;
584 }
586 /* Build the primary virtual function table for TYPE. If BINFO is
587 non-NULL, build the vtable starting with the initial approximation
588 that it is the same as the one which is the head of the association
589 list. Returns a nonzero value if a new vtable is actually
590 created. */
592 static int
594 {
595 tree decl;
596 tree virtuals;
601 {
603 /* We have already created a vtable for this base, so there's
604 no need to do it again. */
611 }
612 else
613 {
616 }
618 #ifdef GATHER_STATISTICS
621 #endif
623 /* Initialize the association list for this type, based
624 on our first approximation. */
629 }
631 /* Give BINFO a new virtual function table which is initialized
632 with a skeleton-copy of its original initialization. The only
633 entry that changes is the `delta' entry, so we can really
634 share a lot of structure.
636 FOR_TYPE is the most derived type which caused this table to
637 be needed.
639 Returns nonzero if we haven't met BINFO before.
641 The order in which vtables are built (by calling this function) for
642 an object must remain the same, otherwise a binary incompatibility
643 can result. */
645 static int
647 {
649 /* We already created a vtable for this base. There's no need to
650 do it again. */
653 /* Remember that we've created a vtable for this BINFO, so that we
654 don't try to do so again. */
657 /* Make fresh virtual list, so we can smash it later. */
660 /* Secondary vtables are laid out as part of the same structure as
661 the primary vtable. */
664 }
666 /* Create a new vtable for BINFO which is the hierarchy dominated by
667 T. Return nonzero if we actually created a new vtable. */
669 static int
671 {
673 /* In this case, it is *type*'s vtable we are modifying. We start
674 with the approximation that its vtable is that of the
675 immediate base class. */
676 /* ??? This actually passes TYPE_BINFO (t), not the primary base binfo,
677 since we've updated DECL_CONTEXT (TYPE_VFIELD (t)) by now. */
679 t);
680 else
681 /* This is our very own copy of `basetype' to play with. Later,
682 we will fill in all the virtual functions that override the
683 virtual functions in these base classes which are not defined
684 by the current type. */
686 }
688 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
689 (which is in the hierarchy dominated by T) list FNDECL as its
690 BV_FN. DELTA is the required constant adjustment from the `this'
691 pointer where the vtable entry appears to the `this' required when
692 the function is actually called. */
694 static void
696 tree binfo,
697 tree fndecl,
698 tree delta,
700 {
701 tree v;
707 {
708 /* We need a new vtable for BINFO. */
710 {
711 /* If we really did make a new vtable, we also made a copy
712 of the BINFO_VIRTUALS list. Now, we have to find the
713 corresponding entry in that list. */
718 }
723 }
724 }
726 \f
727 /* Add method METHOD to class TYPE. If ERROR_P is true, we are adding
728 the method after the class has already been defined because a
729 declaration for it was seen. (Even though that is erroneous, we
730 add the method for improved error recovery.) */
732 void
734 {
738 tree method_vec;
743 /* Make a new method vector. We start with 8 entries. We must
744 allocate at least two (for constructors and destructors), and
745 we're going to end up with an assignment operator at some point
746 as well.
748 We could use a TREE_LIST for now, and convert it to a TREE_VEC
749 in finish_struct, but we would probably waste more memory
750 making the links in the list than we would by over-allocating
751 the size of the vector here. Furthermore, we would complicate
752 all the code that expects this to be a vector. */
758 /* Constructors and destructors go in special slots. */
763 else
764 {
767 /* See if we already have an entry with this name. */
769 {
777 {
781 /* If we need to move things up, see if there's
782 space. */
784 {
787 slot++;
788 }
790 }
793 }
796 {
797 /* We need a bigger method vector. */
799 tree new_vec;
801 /* In the non-error case, we are processing a class
802 definition. Double the size of the vector to give room
803 for new methods. */
806 /* In the error case, the vector is already complete. We
807 don't expect many errors, and the rest of the front-end
808 will get confused if there are empty slots in the vector. */
809 else
817 }
820 {
821 /* Type conversion operators have to come before ordinary
822 methods; add_conversions depends on this to speed up
823 looking for conversion operators. So, if necessary, we
824 slide some of the vector elements up. In theory, this
825 makes this algorithm O(N^2) but we don't expect many
826 conversion operators. */
829 else
831 {
835 /* There are no more entries in the vector, so we
836 can insert the new conversion operator here. */
840 /* We can insert the new function right at the
841 SLOTth position. */
843 }
848 /* There is nothing in the Ith slot, so we can avoid
849 moving anything. */
850 ;
851 else
852 {
853 /* We know the last slot in the vector is empty
854 because we know that at this point there's room
855 for a new function. */
860 }
861 }
862 }
865 /* TYPE is a template class. Don't issue any errors now; wait
866 until instantiation time to complain. */
867 ;
868 else
869 {
870 tree fns;
872 /* Check to see if we've already got this method. */
874 fns;
876 {
878 tree parms1;
879 tree parms2;
885 /* [over.load] Member function declarations with the
886 same name and the same parameter types cannot be
887 overloaded if any of them is a static member
888 function declaration.
890 [namespace.udecl] When a using-declaration brings names
891 from a base class into a derived class scope, member
892 functions in the derived class override and/or hide member
893 functions with the same name and parameter types in a base
894 class (rather than conflicting). */
898 /* Compare the quals on the 'this' parm. Don't compare
899 the whole types, as used functions are treated as
900 coming from the using class in overload resolution. */
907 /* For templates, the template parms must be identical. */
922 {
924 /* Defer to the local function. */
926 else
927 {
931 /* We don't call duplicate_decls here to merge
932 the declarations because that will confuse
933 things if the methods have inline
934 definitions. In particular, we will crash
935 while processing the definitions. */
937 }
938 }
939 }
940 }
942 /* Actually insert the new method. */
946 /* Add the new binding. */
951 }
953 /* Subroutines of finish_struct. */
955 /* Look through the list of fields for this struct, deleting
956 duplicates as we go. This must be recursive to handle
957 anonymous unions.
959 FIELD is the field which may not appear anywhere in FIELDS.
960 FIELD_PTR, if non-null, is the starting point at which
961 chained deletions may take place.
962 The value returned is the first acceptable entry found
963 in FIELDS.
965 Note that anonymous fields which are not of UNION_TYPE are
966 not duplicates, they are just anonymous fields. This happens
967 when we have unnamed bitfields, for example. */
969 static tree
971 {
972 tree x;
975 {
982 }
983 else
984 {
986 {
988 {
994 {
997 else
999 }
1000 }
1002 /* A using declaration is allowed to appear more than
1003 once. We'll prune these from the field list later, and
1004 handle_using_decl will complain about invalid multiple
1005 uses. */
1006 ;
1008 {
1015 x);
1018 {
1022 }
1025 {
1026 /* Hide tag decls. */
1033 x);
1034 }
1035 else
1039 else
1041 }
1042 }
1043 }
1045 }
1047 static void
1049 {
1050 tree x;
1053 }
1055 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1056 legit, otherwise return 0. */
1058 static int
1060 {
1061 tree elem;
1071 {
1073 {
1076 else
1079 }
1080 else
1081 {
1082 /* They're changing the access to the same thing they changed
1083 it to before. That's OK. */
1084 ;
1085 }
1086 }
1087 else
1088 {
1092 }
1094 }
1096 /* Process the USING_DECL, which is a member of T. */
1098 static void
1100 {
1103 tree access
1109 tree old_value;
1113 {
1116 }
1119 {
1122 }
1124 {
1127 }
1132 {
1135 }
1138 /* Ignore base type this came from. */
1143 {
1149 else
1151 }
1157 ;
1159 {
1161 /* It's OK to use functions from a base when there are functions with
1163 else
1164 {
1169 }
1170 }
1172 {
1176 }
1178 /* Make type T see field decl FDECL with access ACCESS.*/
1181 {
1184 }
1185 else
1187 }
1188 \f
1189 /* Run through the base clases of T, updating
1190 CANT_HAVE_DEFAULT_CTOR_P, CANT_HAVE_CONST_CTOR_P, and
1191 NO_CONST_ASN_REF_P. Also set flag bits in T based on properties of
1192 the bases. */
1194 static void
1199 {
1203 tree binfos;
1209 /* An aggregate cannot have baseclasses. */
1213 {
1214 tree base_binfo;
1215 tree basetype;
1217 /* Figure out what base we're looking at. */
1221 /* If the type of basetype is incomplete, then we already
1222 complained about that fact (and we should have fixed it up as
1223 well). */
1225 {
1227 /* The base type is of incomplete type. It is
1228 probably best to pretend that it does not
1229 exist. */
1237 }
1239 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1240 here because the case of virtual functions but non-virtual
1241 dtor is handled in finish_struct_1. */
1245 basetype);
1247 /* If the base class doesn't have copy constructors or
1248 assignment operators that take const references, then the
1249 derived class cannot have such a member automatically
1250 generated. */
1256 /* Similarly, if the base class doesn't have a default
1257 constructor, then the derived class won't have an
1258 automatically generated default constructor. */
1261 {
1265 basetype);
1266 }
1269 /* A virtual base does not effect nearly emptiness. */
1270 ;
1272 {
1274 /* And if there is more than one nearly empty base, then the
1275 derived class is not nearly empty either. */
1277 else
1278 /* Remember we've seen one. */
1280 }
1282 /* If the base class is not empty or nearly empty, then this
1283 class cannot be nearly empty. */
1286 /* A lot of properties from the bases also apply to the derived
1287 class. */
1300 }
1301 }
1303 /* Set BINFO_PRIMARY_BASE_OF for all binfos in the hierarchy
1304 dominated by TYPE that are primary bases. */
1306 static void
1308 {
1309 tree binfo;
1311 /* Walk the bases in inheritance graph order. */
1313 {
1320 else
1321 {
1323 /* A virtual binfo might have been copied from within
1324 another hierarchy. As we're about to use it as a primary
1325 base, make sure the offsets match. */
1327 {
1334 }
1335 }
1336 }
1337 }
1339 /* Make the BINFO the primary base of T. */
1341 static void
1343 {
1344 tree basetype;
1351 }
1353 /* Determine the primary class for T. */
1355 static void
1357 {
1359 tree vbases;
1360 tree type_binfo;
1362 /* If there are no baseclasses, there is certainly no primary base. */
1369 {
1374 {
1375 /* We prefer a non-virtual base, although a virtual one will
1376 do. */
1381 {
1384 }
1385 else
1386 {
1387 tree vfields;
1389 /* Only add unique vfields, and flatten them out as we go. */
1391 vfields;
1399 }
1400 }
1401 }
1406 /* Find the indirect primary bases - those virtual bases which are primary
1407 bases of something else in this hierarchy. */
1409 vbases;
1411 {
1414 /* See if this virtual base is an indirect primary base. To be so,
1415 it must be a primary base within the hierarchy of one of our
1416 direct bases. */
1418 {
1420 tree v;
1423 v;
1425 {
1431 {
1434 }
1435 }
1437 /* If we've discovered that this virtual base is an indirect
1438 primary base, then we can move on to the next virtual
1439 base. */
1442 }
1443 }
1445 /* A "nearly-empty" virtual base class can be the primary base
1446 class, if no non-virtual polymorphic base can be found. */
1448 {
1449 /* If not NULL, this is the best primary base candidate we have
1450 found so far. */
1452 tree base_binfo;
1454 /* Loop over the baseclasses. */
1456 base_binfo;
1458 {
1463 {
1464 /* If this is not an indirect primary base, then it's
1465 definitely our primary base. */
1467 {
1470 }
1472 /* If this is an indirect primary base, it still could be
1473 our primary base -- unless we later find there's another
1474 nearly-empty virtual base that isn't an indirect
1475 primary base. */
1478 }
1479 }
1481 /* If we've got a primary base, use it. */
1483 {
1487 }
1488 }
1490 /* Mark the primary base classes at this point. */
1492 }
1493 \f
1494 /* Set memoizing fields and bits of T (and its variants) for later
1495 use. */
1497 static void
1499 {
1502 /* Fix up variants (if any). */
1505 {
1506 /* These fields are in the _TYPE part of the node, not in
1507 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1518 /* Copy whatever these are holding today. */
1525 }
1528 /* For a class w/o baseclasses, `finish_struct' has set
1529 CLASS_TYPE_ABSTRACT_VIRTUALS correctly (by
1530 definition). Similarly for a class whose base classes do not
1531 have vtables. When neither of these is true, we might have
1532 removed abstract virtuals (by providing a definition), added
1533 some (by declaring new ones), or redeclared ones from a base
1534 class. We need to recalculate what's really an abstract virtual
1535 at this point (by looking in the vtables). */
1539 {
1540 /* Notice whether this class has type conversion functions defined. */
1543 tree basetype;
1546 {
1550 }
1551 }
1553 /* If this type has a copy constructor or a destructor, force its mode to
1554 be BLKmode, and force its TREE_ADDRESSABLE bit to be nonzero. This
1555 will cause it to be passed by invisible reference and prevent it from
1556 being returned in a register. */
1558 {
1559 tree variants;
1562 {
1565 }
1566 }
1567 }
1569 /* Issue warnings about T having private constructors, but no friends,
1570 and so forth.
1572 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1573 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1574 non-private static member functions. */
1576 static void
1578 {
1581 tree fn;
1584 /* If the class has friends, those entities might create and
1585 access instances, so we should not warn. */
1588 /* We will have warned when the template was declared; there's
1589 no need to warn on every instantiation. */
1591 /* There's no reason to even consider warning about this
1592 class. */
1595 /* We only issue one warning, if more than one applies, because
1596 otherwise, on code like:
1598 class A {
1599 // Oops - forgot `public:'
1600 A();
1601 A(const A&);
1602 ~A();
1603 };
1605 we warn several times about essentially the same problem. */
1607 /* Check to see if all (non-constructor, non-destructor) member
1608 functions are private. (Since there are no friends or
1609 non-private statics, we can't ever call any of the private member
1610 functions.) */
1612 /* We're not interested in compiler-generated methods; they don't
1613 provide any way to call private members. */
1615 {
1617 {
1619 /* A non-private static member function is just like a
1620 friend; it can create and invoke private member
1621 functions, and be accessed without a class
1622 instance. */
1626 /* Keep searching for a static member function. */
1627 }
1630 }
1633 {
1634 /* There are no non-private methods, and there's at least one
1635 private member function that isn't a constructor or
1636 destructor. (If all the private members are
1637 constructors/destructors we want to use the code below that
1638 issues error messages specifically referring to
1639 constructors/destructors.) */
1645 {
1648 }
1650 {
1653 }
1654 }
1656 /* Even if some of the member functions are non-private, the class
1657 won't be useful for much if all the constructors or destructors
1658 are private: such an object can never be created or destroyed. */
1660 {
1664 {
1666 t);
1668 }
1669 }
1672 {
1675 /* If a non-template class does not define a copy
1676 constructor, one is defined for it, enabling it to avoid
1677 this warning. For a template class, this does not
1678 happen, and so we would normally get a warning on:
1680 template <class T> class C { private: C(); };
1682 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1683 complete non-template or fully instantiated classes have this
1684 flag set. */
1687 else
1689 fn;
1691 {
1693 /* Ideally, we wouldn't count copy constructors (or, in
1694 fact, any constructor that takes an argument of the
1695 class type as a parameter) because such things cannot
1696 be used to construct an instance of the class unless
1697 you already have one. But, for now at least, we're
1698 more generous. */
1700 {
1703 }
1704 }
1707 {
1709 t);
1711 }
1712 }
1713 }
1715 /* Function to help qsort sort FIELD_DECLs by name order. */
1717 static int
1719 {
1723 /* A nontype is "greater" than a type. */
1732 }
1735 gt_pointer_operator new_value;
1739 /* This routine compares two fields like field_decl_cmp but using the
1740 pointer operator in resort_data. */
1742 static int
1744 {
1749 /* A nontype is "greater" than a type. */
1755 {
1762 }
1764 }
1766 /* Resort DECL_SORTED_FIELDS because pointers have been reordered. */
1768 void
1771 gt_pointer_operator new_value,
1773 {
1778 resort_field_decl_cmp);
1779 }
1781 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1783 static int
1785 {
1798 }
1800 /* This routine compares two fields like method_name_cmp but using the
1801 pointer operator in resort_field_decl_data. */
1803 static int
1805 {
1814 {
1821 }
1823 }
1825 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1827 void
1830 gt_pointer_operator new_value,
1832 {
1837 /* The type conversion ops have to live at the front of the vec, so we
1838 can't sort them. */
1840 {
1845 }
1847 {
1851 resort_method_name_cmp);
1852 }
1853 }
1855 /* Warn about duplicate methods in fn_fields. Also compact method
1856 lists so that lookup can be made faster.
1858 Data Structure: List of method lists. The outer list is a
1859 TREE_LIST, whose TREE_PURPOSE field is the field name and the
1860 TREE_VALUE is the DECL_CHAIN of the FUNCTION_DECLs. TREE_CHAIN
1861 links the entire list of methods for TYPE_METHODS. Friends are
1862 chained in the same way as member functions (? TREE_CHAIN or
1863 DECL_CHAIN), but they live in the TREE_TYPE field of the outer
1864 list. That allows them to be quickly deleted, and requires no
1865 extra storage.
1867 Sort methods that are not special (i.e., constructors, destructors,
1868 and type conversion operators) so that we can find them faster in
1869 search. */
1871 static void
1873 {
1874 tree fn_fields;
1875 tree method_vec;
1879 {
1880 /* Clear these for safety; perhaps some parsing error could set
1881 these incorrectly. */
1886 }
1892 /* First fill in entry 0 with the constructors, entry 1 with destructors,
1893 and the next few with type conversion operators (if any). */
1896 /* Clear out this flag. */
1900 /* We thought there was a destructor, but there wasn't. Some
1901 parse errors cause this anomalous situation. */
1904 /* Issue warnings about private constructors and such. If there are
1905 no methods, then some public defaults are generated. */
1908 /* Now sort the methods. */
1910 len--;
1913 /* The type conversion ops have to live at the front of the vec, so we
1914 can't sort them. */
1916 {
1921 }
1924 method_name_cmp);
1925 }
1927 /* Emit error when a duplicate definition of a type is seen. Patch up. */
1929 void
1931 {
1935 /* Pretend we haven't defined this type. */
1937 /* All of the component_decl's were TREE_CHAINed together in the parser.
1938 finish_struct_methods walks these chains and assembles all methods with
1939 the same base name into DECL_CHAINs. Now we don't need the parser chains
1940 anymore, so we unravel them. */
1942 /* This used to be in finish_struct, but it turns out that the
1943 TREE_CHAIN is used by dbxout_type_methods and perhaps some other
1944 things... */
1946 {
1950 {
1953 {
1956 }
1957 }
1958 }
1961 {
1979 }
1987 /* Clear TYPE_LANG_FLAGS -- those in TYPE_LANG_SPECIFIC are cleared above. */
1995 /* But not this one. */
1997 }
1999 /* Make BINFO's vtable have N entries, including RTTI entries,
2000 vbase and vcall offsets, etc. Set its type and call the backend
2001 to lay it out. */
2003 static void
2005 {
2006 tree atype;
2007 tree vtable;
2013 /* We may have to grow the vtable. */
2016 {
2021 /* At one time the vtable info was grabbed 2 words at a time. This
2022 fails on SPARC unless you have 8-byte alignment. */
2025 }
2026 }
2028 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2029 have the same signature. */
2031 int
2033 {
2034 /* One destructor overrides another if they are the same kind of
2035 destructor. */
2039 /* But a non-destructor never overrides a destructor, nor vice
2040 versa, nor do different kinds of destructors override
2041 one-another. For example, a complete object destructor does not
2042 override a deleting destructor. */
2047 {
2055 }
2057 }
2059 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2060 subobject. */
2062 static bool
2064 {
2065 tree probe;
2068 {
2072 /* If we meet a virtual base, we can't follow the inheritance
2073 any more. See if the complete type of DERIVED contains
2074 such a virtual base. */
2078 }
2080 }
2083 /* The function for which we are trying to find a final overrider. */
2084 tree fn;
2085 /* The base class in which the function was declared. */
2086 tree declaring_base;
2087 /* The most derived class in the hierarchy. */
2088 tree most_derived_type;
2089 /* The candidate overriders. */
2090 tree candidates;
2091 /* Binfos which inherited virtually on the currrent path. */
2092 tree vpath;
2095 /* Called from find_final_overrider via dfs_walk. */
2097 static tree
2099 {
2103 {
2104 /* We've found a path to the declaring base. Walk the path from
2105 derived to base, looking for an overrider for FN. */
2108 /* Build the path, using the inheritance chain and record of
2109 virtual inheritance. */
2111 {
2116 {
2119 }
2120 else
2122 }
2123 /* Now walk path, looking for overrides. */
2125 {
2126 tree method = look_for_overrides_here
2130 {
2134 /* Remove any candidates overridden by this new function. */
2136 {
2137 /* If *CANDIDATE overrides METHOD, then METHOD
2138 cannot override anything else on the list. */
2141 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2144 else
2146 }
2148 /* Add the new function. */
2151 }
2152 }
2153 }
2156 }
2158 static tree
2160 {
2168 }
2170 static tree
2172 {
2179 }
2181 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2182 FN and whose TREE_VALUE is the binfo for the base where the
2183 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2184 DERIVED) is the base object in which FN is declared. */
2186 static tree
2188 {
2189 find_final_overrider_data ffod;
2191 /* Getting this right is a little tricky. This is valid:
2193 struct S { virtual void f (); };
2194 struct T { virtual void f (); };
2195 struct U : public S, public T { };
2197 even though calling `f' in `U' is ambiguous. But,
2199 struct R { virtual void f(); };
2200 struct S : virtual public R { virtual void f (); };
2201 struct T : virtual public R { virtual void f (); };
2202 struct U : public S, public T { };
2204 is not -- there's no way to decide whether to put `S::f' or
2205 `T::f' in the vtable for `R'.
2207 The solution is to look at all paths to BINFO. If we find
2208 different overriders along any two, then there is a problem. */
2219 dfs_find_final_overrider,
2220 dfs_find_final_overrider_post,
2221 dfs_find_final_overrider_q,
2224 /* If there was no winner, issue an error message. */
2226 {
2230 }
2233 }
2235 /* Return the index of the vcall offset for FN when TYPE is used as a
2236 virtual base. */
2238 static tree
2240 {
2241 tree v;
2248 /* There should always be an appropriate index. */
2252 }
2254 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2255 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2256 corresponding position in the BINFO_VIRTUALS list. */
2258 static void
2261 {
2262 tree b;
2263 tree overrider;
2264 tree delta;
2265 tree virtual_base;
2266 tree first_defn;
2272 /* Find the nearest primary base (possibly binfo itself) which defines
2273 this function; this is the class the caller will convert to when
2274 calling FN through BINFO. */
2276 {
2281 /* The nearest definition is from a lost primary. */
2284 }
2287 /* Find the final overrider. */
2293 /* Check for adjusting covariant return types. */
2301 {
2302 /* If FN is a covariant thunk, we must figure out the adjustment
2303 to the final base FN was converting to. As OVERRIDER_TARGET might
2304 also be converting to the return type of FN, we have to
2305 combine the two conversions here. */
2309 {
2312 }
2313 else
2317 {
2318 /* There was no existing virtual thunk (which takes
2319 precidence). */
2320 tree thunk_binfo;
2321 base_kind kind;
2329 {
2333 {
2334 /* We convert via virtual base. Find the virtual
2335 base and adjust the fixed offset to be from there. */
2342 }
2344 /* There was an existing fixed offset, this must be
2345 from the base just converted to, and the base the
2346 FN was thunking to. */
2348 else
2350 }
2351 }
2354 /* Replace the overriding function with a covariant thunk. We
2355 will emit the overriding function in its own slot as
2356 well. */
2359 }
2360 else
2363 /* Assume that we will produce a thunk that convert all the way to
2364 the final overrider, and not to an intermediate virtual base. */
2367 /* See if we can convert to an intermediate virtual base first, and then
2368 use the vcall offset located there to finish the conversion. */
2370 {
2371 /* If we find the final overrider, then we can stop
2372 walking. */
2377 /* If we find a virtual base, and we haven't yet found the
2378 overrider, then there is a virtual base between the
2379 declaring base (first_defn) and the final overrider. */
2381 {
2384 }
2385 }
2388 {
2389 /* The ABI specifies that a covariant thunk includes a mangling
2390 for a this pointer adjustment. This-adjusting thunks that
2391 override a function from a virtual base have a vcall
2392 adjustment. When the virtual base in question is a primary
2393 virtual base, we know the adjustments are zero, (and in the
2394 non-covariant case, we would not use the thunk).
2395 Unfortunately we didn't notice this could happen, when
2396 designing the ABI and so never mandated that such a covariant
2397 thunk should be emitted. Because we must use the ABI mandated
2398 name, we must continue searching from the binfo where we
2399 found the most recent definition of the function, towards the
2400 primary binfo which first introduced the function into the
2401 vtable. If that enters a virtual base, we must use a vcall
2402 this-adjusting thunk. Bleah! */
2403 tree probe;
2406 {
2411 }
2413 /* Even if we find a virtual base, the correct delta is
2414 between the overrider and the binfo we're building a vtable
2415 for. */
2417 }
2419 /* Compute the constant adjustment to the `this' pointer. The
2420 `this' pointer, when this function is called, will point at BINFO
2421 (or one of its primary bases, which are at the same offset). */
2423 /* The `this' pointer needs to be adjusted from the declaration to
2424 the nearest virtual base. */
2428 /* If the nearest definition is in a lost primary, we don't need an
2429 entry in our vtable. Except possibly in a constructor vtable,
2430 if we happen to get our primary back. In that case, the offset
2431 will be zero, as it will be a primary base. */
2433 else
2434 /* The `this' pointer needs to be adjusted from pointing to
2435 BINFO to pointing at the base where the final overrider
2436 appears. */
2437 virtual_covariant:
2446 }
2448 /* Called from modify_all_vtables via dfs_walk. */
2450 static tree
2452 {
2454 primary base; we're not going to use that vtable anyhow.
2455 We do still need to do this for virtual primary bases, as they
2456 could become non-primary in a construction vtable. */
2458 /* Similarly, a base without a vtable needs no modification. */
2460 {
2462 tree virtuals;
2463 tree old_virtuals;
2468 /* Now, go through each of the virtual functions in the virtual
2469 function table for BINFO. Find the final overrider, and
2470 update the BINFO_VIRTUALS list appropriately. */
2473 virtuals;
2477 binfo,
2480 }
2485 }
2487 /* Update all of the primary and secondary vtables for T. Create new
2488 vtables as required, and initialize their RTTI information. Each
2489 of the functions in VIRTUALS is declared in T and may override a
2490 virtual function from a base class; find and modify the appropriate
2491 entries to point to the overriding functions. Returns a list, in
2492 declaration order, of the virtual functions that are declared in T,
2493 but do not appear in the primary base class vtable, and which
2494 should therefore be appended to the end of the vtable for T. */
2496 static tree
2498 {
2502 /* Update all of the vtables. */
2506 /* Add virtual functions not already in our primary vtable. These
2507 will be both those introduced by this class, and those overridden
2508 from secondary bases. It does not include virtuals merely
2509 inherited from secondary bases. */
2511 {
2516 {
2517 /* We don't need to adjust the `this' pointer when
2518 calling this function. */
2522 /* This is a function not already in our vtable. Keep it. */
2524 }
2525 else
2526 /* We've already got an entry for this function. Skip it. */
2528 }
2531 }
2533 /* Get the base virtual function declarations in T that have the
2534 indicated NAME. */
2536 static tree
2538 {
2539 tree methods;
2544 /* Find virtual functions in T with the indicated NAME. */
2548 methods;
2550 {
2556 }
2562 {
2565 base_fndecls);
2566 }
2569 }
2571 /* If this declaration supersedes the declaration of
2572 a method declared virtual in the base class, then
2573 mark this field as being virtual as well. */
2575 static void
2577 {
2579 /* In [temp.mem] we have:
2581 A specialization of a member function template does not
2582 override a virtual function from a base class. */
2588 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2589 the error_mark_node so that we know it is an overriding
2590 function. */
2594 {
2598 }
2599 }
2601 /* Warn about hidden virtual functions that are not overridden in t.
2602 We know that constructors and destructors don't apply. */
2604 void
2606 {
2611 /* We go through each separately named virtual function. */
2613 {
2614 tree fns;
2615 tree name;
2616 tree fndecl;
2617 tree base_fndecls;
2620 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2621 have the same name. Figure out what name that is. */
2623 /* There are no possibly hidden functions yet. */
2625 /* Iterate through all of the base classes looking for possibly
2626 hidden functions. */
2628 {
2631 base_fndecls);
2632 }
2634 /* If there are no functions to hide, continue. */
2638 /* Remove any overridden functions. */
2640 {
2643 {
2647 /* If the method from the base class has the same
2648 signature as the method from the derived class, it
2649 has been overridden. */
2652 else
2654 }
2655 }
2657 /* Now give a warning for all base functions without overriders,
2658 as they are hidden. */
2660 {
2661 /* Here we know it is a hider, and no overrider exists. */
2666 }
2667 }
2668 }
2670 /* Check for things that are invalid. There are probably plenty of other
2671 things we should check for also. */
2673 static void
2675 {
2676 tree field;
2679 {
2687 {
2690 {
2691 /* We're generally only interested in entities the user
2692 declared, but we also find nested classes by noticing
2693 the TYPE_DECL that we create implicitly. You're
2694 allowed to put one anonymous union inside another,
2695 though, so we explicitly tolerate that. We use
2696 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2697 we also allow unnamed types used for defining fields. */
2705 elt);
2708 {
2710 elt);
2712 }
2716 elt);
2719 elt);
2723 }
2724 }
2725 }
2726 }
2728 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2729 will be used later during class template instantiation.
2730 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2731 a non-static member data (FIELD_DECL), a member function
2732 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2733 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2734 When FRIEND_P is nonzero, T is either a friend class
2735 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2736 (FUNCTION_DECL, TEMPLATE_DECL). */
2738 void
2740 {
2741 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2746 }
2748 /* Create default constructors, assignment operators, and so forth for
2749 the type indicated by T, if they are needed.
2750 CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2751 CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2752 class cannot have a default constructor, copy constructor taking a
2753 const reference argument, or an assignment operator taking a const
2754 reference, respectively. If a virtual destructor is created, its
2755 DECL is returned; otherwise the return value is NULL_TREE. */
2757 static void
2762 {
2763 tree default_fn;
2770 /* Destructor. */
2772 {
2776 /* If we couldn't make it work, then pretend we didn't need it. */
2779 else
2780 {
2786 }
2787 }
2788 else
2789 /* Any non-implicit destructor is non-trivial. */
2792 /* Default constructor. */
2794 {
2798 }
2800 /* Copy constructor. */
2802 {
2803 /* ARM 12.18: You get either X(X&) or X(const X&), but
2804 not both. --Chip */
2805 default_fn
2810 }
2812 /* Assignment operator. */
2814 {
2815 default_fn
2820 }
2822 /* Now, hook all of the new functions on to TYPE_METHODS,
2823 and add them to the CLASSTYPE_METHOD_VEC. */
2825 {
2828 }
2830 /* G++ 3.2 put the implicit destructor at the *beginning* of the
2831 list, which cause the destructor to be emitted in an incorrect
2832 location in the vtable. */
2834 else
2835 {
2838 "and may change in a future version of GCC due to implicit "
2840 t);
2843 }
2846 }
2848 /* Subroutine of finish_struct_1. Recursively count the number of fields
2849 in TYPE, including anonymous union members. */
2851 static int
2853 {
2854 tree x;
2857 {
2860 else
2862 }
2864 }
2866 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2867 TREE_LIST FIELDS to the TREE_VEC FIELD_VEC, starting at offset IDX. */
2869 static int
2871 {
2872 tree x;
2874 {
2877 else
2879 }
2881 }
2883 /* FIELD is a bit-field. We are finishing the processing for its
2884 enclosing type. Issue any appropriate messages and set appropriate
2885 flags. */
2887 static void
2889 {
2893 /* Detect invalid bit-field type. */
2896 {
2899 }
2901 /* Detect and ignore out of range field width. */
2903 {
2906 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2909 /* detect invalid field size. */
2912 else
2916 {
2918 field);
2920 }
2922 {
2925 }
2927 {
2930 }
2940 min_precision
2945 }
2947 /* Remove the bit-field width indicator so that the rest of the
2948 compiler does not treat that value as an initializer. */
2952 {
2958 {
2959 #ifdef EMPTY_FIELD_BOUNDARY
2961 EMPTY_FIELD_BOUNDARY);
2962 #endif
2963 #ifdef PCC_BITFIELD_TYPE_MATTERS
2965 {
2969 }
2970 #endif
2971 }
2972 }
2973 else
2974 {
2975 /* Non-bit-fields are aligned for their type. */
2980 }
2981 }
2983 /* FIELD is a non bit-field. We are finishing the processing for its
2984 enclosing type T. Issue any appropriate messages and set appropriate
2985 flags. */
2987 static void
2989 tree t,
2994 {
2997 /* An anonymous union cannot contain any fields which would change
2998 the settings of CANT_HAVE_CONST_CTOR and friends. */
3000 ;
3001 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
3002 structs. So, we recurse through their fields here. */
3004 {
3005 tree fields;
3011 any_default_members);
3012 }
3013 /* Check members with class type for constructors, destructors,
3014 etc. */
3016 {
3017 /* Never let anything with uninheritable virtuals
3018 make it through without complaint. */
3022 {
3025 field);
3028 field);
3031 field);
3032 }
3033 else
3034 {
3040 }
3051 }
3053 {
3054 /* `build_class_init_list' does not recognize
3055 non-FIELD_DECLs. */
3059 }
3060 }
3062 /* Check the data members (both static and non-static), class-scoped
3063 typedefs, etc., appearing in the declaration of T. Issue
3064 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3065 declaration order) of access declarations; each TREE_VALUE in this
3066 list is a USING_DECL.
3068 In addition, set the following flags:
3070 EMPTY_P
3071 The class is empty, i.e., contains no non-static data members.
3073 CANT_HAVE_DEFAULT_CTOR_P
3074 This class cannot have an implicitly generated default
3075 constructor.
3077 CANT_HAVE_CONST_CTOR_P
3078 This class cannot have an implicitly generated copy constructor
3079 taking a const reference.
3081 CANT_HAVE_CONST_ASN_REF
3082 This class cannot have an implicitly generated assignment
3083 operator taking a const reference.
3085 All of these flags should be initialized before calling this
3086 function.
3088 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3089 fields can be added by adding to this chain. */
3091 static void
3096 {
3102 /* First, delete any duplicate fields. */
3105 /* Assume there are no access declarations. */
3107 /* Assume this class has no pointer members. */
3109 /* Assume none of the members of this class have default
3110 initializations. */
3114 {
3121 {
3125 /* We don't treat zero-width bitfields as making a class
3126 non-empty. */
3127 ;
3128 else
3129 {
3130 tree element_type;
3132 /* The class is non-empty. */
3134 /* The class is not even nearly empty. */
3136 /* If one of the data members contains an empty class,
3137 so does T. */
3142 }
3143 }
3146 {
3147 /* Prune the access declaration from the list of fields. */
3150 /* Save the access declarations for our caller. */
3153 /* Since we've reset *FIELD there's no reason to skip to the
3154 next field. */
3157 }
3163 /* If we've gotten this far, it's a data member, possibly static,
3164 or an enumerator. */
3168 /* ``A local class cannot have static data members.'' ARM 9.4 */
3172 /* Perform error checking that did not get done in
3173 grokdeclarator. */
3175 {
3177 x);
3180 }
3182 {
3186 }
3188 {
3192 }
3197 /* When this goes into scope, it will be a non-local reference. */
3204 {
3206 /* Unions cannot have static members. */
3210 }
3212 /* Now it can only be a FIELD_DECL. */
3217 /* If this is of reference type, check if it needs an init.
3218 Also do a little ANSI jig if necessary. */
3220 {
3225 /* ARM $12.6.2: [A member initializer list] (or, for an
3226 aggregate, initialization by a brace-enclosed list) is the
3227 only way to initialize nonstatic const and reference
3228 members. */
3235 }
3246 /* DR 148 now allows pointers to members (which are POD themselves),
3247 to be allowed in POD structs. */
3253 /* If any field is const, the structure type is pseudo-const. */
3255 {
3260 /* ARM $12.6.2: [A member initializer list] (or, for an
3261 aggregate, initialization by a brace-enclosed list) is the
3262 only way to initialize nonstatic const and reference
3263 members. */
3270 }
3271 /* A field that is pseudo-const makes the structure likewise. */
3273 {
3278 }
3280 /* Core issue 80: A nonstatic data member is required to have a
3281 different name from the class iff the class has a
3282 user-defined constructor. */
3286 /* We set DECL_C_BIT_FIELD in grokbitfield.
3287 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3290 else
3292 cant_have_const_ctor_p,
3293 cant_have_default_ctor_p,
3294 no_const_asn_ref_p,
3296 }
3298 /* Effective C++ rule 11. */
3301 {
3305 {
3309 }
3312 }
3315 /* Check anonymous struct/anonymous union fields. */
3318 /* We've built up the list of access declarations in reverse order.
3319 Fix that now. */
3321 }
3323 /* If TYPE is an empty class type, records its OFFSET in the table of
3324 OFFSETS. */
3326 static int
3328 {
3329 splay_tree_node n;
3334 /* Record the location of this empty object in OFFSETS. */
3342 type,
3346 }
3348 /* Returns nonzero if TYPE is an empty class type and there is
3349 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3351 static int
3353 {
3354 splay_tree_node n;
3355 tree t;
3360 /* Record the location of this empty object in OFFSETS. */
3370 }
3372 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3373 F for every subobject, passing it the type, offset, and table of
3374 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3375 be traversed.
3377 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3378 than MAX_OFFSET will not be walked.
3380 If F returns a nonzero value, the traversal ceases, and that value
3381 is returned. Otherwise, returns zero. */
3383 static int
3385 subobject_offset_fn f,
3386 tree offset,
3387 splay_tree offsets,
3388 tree max_offset,
3390 {
3394 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3395 stop. */
3400 {
3404 }
3407 {
3408 tree field;
3409 tree binfo;
3412 /* Avoid recursing into objects that are not interesting. */
3416 /* Record the location of TYPE. */
3421 /* Iterate through the direct base classes of TYPE. */
3425 {
3426 tree binfo_offset;
3441 offset,
3443 else
3444 {
3445 tree orig_binfo;
3446 /* We cannot rely on BINFO_OFFSET being set for the base
3447 class yet, but the offsets for direct non-virtual
3448 bases can be calculated by going back to the TYPE. */
3451 offset,
3453 }
3456 f,
3457 binfo_offset,
3458 offsets,
3459 max_offset,
3464 }
3467 {
3468 tree vbase;
3470 /* Iterate through the virtual base classes of TYPE. In G++
3471 3.2, we included virtual bases in the direct base class
3472 loop above, which results in incorrect results; the
3473 correct offsets for virtual bases are only known when
3474 working with the most derived type. */
3477 vbase;
3479 {
3482 f,
3484 offset,
3486 offsets,
3487 max_offset,
3491 }
3492 else
3493 {
3494 /* We still have to walk the primary base, if it is
3495 virtual. (If it is non-virtual, then it was walked
3496 above.) */
3500 {
3501 r = (walk_subobject_offsets
3506 }
3507 }
3508 }
3510 /* Iterate through the fields of TYPE. */
3513 {
3514 tree field_offset;
3518 else
3519 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3523 f,
3525 offset,
3526 field_offset),
3527 offsets,
3528 max_offset,
3532 }
3533 }
3535 {
3538 tree index;
3540 /* Avoid recursing into objects that are not interesting. */
3545 /* Step through each of the elements in the array. */
3547 /* G++ 3.2 had an off-by-one error here. */
3552 {
3554 f,
3555 offset,
3556 offsets,
3557 max_offset,
3563 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3564 there's no point in iterating through the remaining
3565 elements of the array. */
3568 }
3569 }
3572 }
3574 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3575 OFFSETS. If VBASES_P is nonzero, virtual bases of TYPE are
3576 examined. */
3578 static void
3580 tree offset,
3581 splay_tree offsets,
3583 {
3586 }
3588 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3589 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3590 virtual bases of TYPE are examined. */
3592 static int
3594 tree offset,
3595 splay_tree offsets,
3597 {
3598 splay_tree_node max_node;
3600 /* Get the node in OFFSETS that indicates the maximum offset where
3601 an empty subobject is located. */
3603 /* If there aren't any empty subobjects, then there's no point in
3604 performing this check. */
3610 vbases_p);
3611 }
3613 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3614 non-static data member of the type indicated by RLI. BINFO is the
3615 binfo corresponding to the base subobject, OFFSETS maps offsets to
3616 types already located at those offsets. This function determines
3617 the position of the DECL. */
3619 static void
3621 tree decl,
3622 tree binfo,
3623 splay_tree offsets)
3624 {
3627 tree type;
3630 {
3631 /* For the purposes of determining layout conflicts, we want to
3632 use the class type of BINFO; TREE_TYPE (DECL) will be the
3633 CLASSTYPE_AS_BASE version, which does not contain entries for
3634 zero-sized bases. */
3637 }
3638 else
3639 {
3642 }
3644 /* Try to place the field. It may take more than one try if we have
3645 a hard time placing the field without putting two objects of the
3646 same type at the same address. */
3648 {
3651 /* Place this field. */
3655 /* We have to check to see whether or not there is already
3656 something of the same type at the offset we're about to use.
3657 For example:
3659 struct S {};
3660 struct T : public S { int i; };
3661 struct U : public S, public T {};
3663 Here, we put S at offset zero in U. Then, we can't put T at
3664 offset zero -- its S component would be at the same address
3665 as the S we already allocated. So, we have to skip ahead.
3666 Since all data members, including those whose type is an
3667 empty class, have nonzero size, any overlap can happen only
3668 with a direct or indirect base-class -- it can't happen with
3669 a data member. */
3670 /* G++ 3.2 did not check for overlaps when placing a non-empty
3671 virtual base. */
3676 {
3677 /* Strip off the size allocated to this field. That puts us
3678 at the first place we could have put the field with
3679 proper alignment. */
3682 /* Bump up by the alignment required for the type. */
3683 rli->bitpos
3689 }
3690 else
3691 /* There was no conflict. We're done laying out this field. */
3693 }
3695 /* Now that we know where it will be placed, update its
3696 BINFO_OFFSET. */
3698 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3699 this point because their BINFO_OFFSET is copied from another
3700 hierarchy. Therefore, we may not need to add the entire
3701 OFFSET. */
3706 }
3708 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3710 static int
3712 tree offset,
3713 splay_tree offsets ATTRIBUTE_UNUSED)
3714 {
3716 }
3718 /* Layout the empty base BINFO. EOC indicates the byte currently just
3719 past the end of the class, and should be correctly aligned for a
3720 class of the type indicated by BINFO; OFFSETS gives the offsets of
3721 the empty bases allocated so far. T is the most derived
3722 type. Return nonzero iff we added it at the end. */
3724 static bool
3726 {
3727 tree alignment;
3731 /* This routine should only be used for empty classes. */
3742 /* This is an empty base class. We first try to put it at offset
3743 zero. */
3746 offsets,
3748 {
3749 /* That didn't work. Now, we move forward from the next
3750 available spot in the class. */
3754 {
3757 offsets,
3759 /* We finally found a spot where there's no overlap. */
3762 /* There's overlap here, too. Bump along to the next spot. */
3764 }
3765 }
3767 }
3769 /* Layout the the base given by BINFO in the class indicated by RLI.
3770 *BASE_ALIGN is a running maximum of the alignments of
3771 any base class. OFFSETS gives the location of empty base
3772 subobjects. T is the most derived type. Return nonzero if the new
3773 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3774 *NEXT_FIELD, unless BINFO is for an empty base class.
3776 Returns the location at which the next field should be inserted. */
3781 {
3786 /* This error is now reported in xref_tag, thus giving better
3787 location information. */
3790 /* Place the base class. */
3792 {
3793 tree decl;
3795 /* The containing class is non-empty because it has a non-empty
3796 base class. */
3799 /* Create the FIELD_DECL. */
3809 /* Try to place the field. It may take more than one try if we
3810 have a hard time placing the field without putting two
3811 objects of the same type at the same address. */
3813 /* Add the new FIELD_DECL to the list of fields for T. */
3817 }
3818 else
3819 {
3820 tree eoc;
3823 /* On some platforms (ARM), even empty classes will not be
3824 byte-aligned. */
3828 /* A nearly-empty class "has no proper base class that is empty,
3829 not morally virtual, and at an offset other than zero." */
3831 {
3834 /* The check above (used in G++ 3.2) is insufficient because
3835 an empty class placed at offset zero might itself have an
3836 empty base at a nonzero offset. */
3838 empty_base_at_nonzero_offset_p,
3839 size_zero_node,
3843 {
3849 }
3850 }
3852 /* We do not create a FIELD_DECL for empty base classes because
3853 it might overlap some other field. We want to be able to
3854 create CONSTRUCTORs for the class by iterating over the
3855 FIELD_DECLs, and the back end does not handle overlapping
3856 FIELD_DECLs. */
3858 /* An empty virtual base causes a class to be non-empty
3859 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3860 here because that was already done when the virtual table
3861 pointer was created. */
3862 }
3864 /* Record the offsets of BINFO and its base subobjects. */
3867 offsets,
3871 }
3873 /* Layout all of the non-virtual base classes. Record empty
3874 subobjects in OFFSETS. T is the most derived type. Return nonzero
3875 if the type cannot be nearly empty. The fields created
3876 corresponding to the base classes will be inserted at
3877 *NEXT_FIELD. */
3879 static void
3882 {
3883 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3884 subobjects. */
3889 /* The primary base class is always allocated first. */
3894 /* Now allocate the rest of the bases. */
3896 {
3897 tree base_binfo;
3901 /* The primary base was already allocated above, so we don't
3902 need to allocate it again here. */
3906 /* Virtual bases are added at the end (a primary virtual base
3907 will have already been added). */
3913 }
3914 }
3916 /* Go through the TYPE_METHODS of T issuing any appropriate
3917 diagnostics, figuring out which methods override which other
3918 methods, and so forth. */
3920 static void
3922 {
3923 tree x;
3926 {
3927 /* If this was an evil function, don't keep it in class. */
3936 /* The name of the field is the original field name
3937 Save this in auxiliary field for later overloading. */
3939 {
3944 }
3945 }
3946 }
3948 /* FN is a constructor or destructor. Clone the declaration to create
3949 a specialized in-charge or not-in-charge version, as indicated by
3950 NAME. */
3952 static tree
3954 {
3955 tree parms;
3956 tree clone;
3958 /* Copy the function. */
3960 /* Remember where this function came from. */
3963 /* Reset the function name. */
3966 /* There's no pending inline data for this function. */
3969 /* And it hasn't yet been deferred. */
3972 /* The base-class destructor is not virtual. */
3974 {
3978 }
3980 /* If there was an in-charge parameter, drop it from the function
3981 type. */
3983 {
3984 tree basetype;
3985 tree parmtypes;
3986 tree exceptions;
3991 /* Skip the `this' parameter. */
3993 /* Skip the in-charge parameter. */
3995 /* And the VTT parm, in a complete [cd]tor. */
3999 /* If this is subobject constructor or destructor, add the vtt
4000 parameter. */
4004 parmtypes);
4007 exceptions);
4008 }
4010 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
4011 aren't function parameters; those are the template parameters. */
4013 {
4015 /* Remove the in-charge parameter. */
4017 {
4021 }
4022 /* And the VTT parm, in a complete [cd]tor. */
4024 {
4027 else
4028 {
4032 }
4033 }
4036 {
4039 }
4040 }
4042 /* Create the RTL for this function. */
4046 /* Make it easy to find the CLONE given the FN. */
4050 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
4052 {
4053 tree result;
4060 }
4065 }
4067 /* Produce declarations for all appropriate clones of FN. If
4068 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4069 CLASTYPE_METHOD_VEC as well. */
4071 void
4073 {
4074 tree clone;
4076 /* Avoid inappropriate cloning. */
4082 {
4083 /* For each constructor, we need two variants: an in-charge version
4084 and a not-in-charge version. */
4091 }
4092 else
4093 {
4096 /* For each destructor, we need three variants: an in-charge
4097 version, a not-in-charge version, and an in-charge deleting
4098 version. We clone the deleting version first because that
4099 means it will go second on the TYPE_METHODS list -- and that
4100 corresponds to the correct layout order in the virtual
4101 function table.
4103 For a non-virtual destructor, we do not build a deleting
4104 destructor. */
4106 {
4110 }
4117 }
4119 /* Note that this is an abstract function that is never emitted. */
4121 }
4123 /* DECL is an in charge constructor, which is being defined. This will
4124 have had an in class declaration, from whence clones were
4125 declared. An out-of-class definition can specify additional default
4126 arguments. As it is the clones that are involved in overload
4127 resolution, we must propagate the information from the DECL to its
4128 clones. */
4130 void
4132 {
4133 tree clone;
4137 {
4144 /* Skip the 'this' parameter. */
4160 {
4165 {
4166 /* A default parameter has been added. Adjust the
4167 clone's parameters. */
4170 tree type;
4175 {
4178 clone_parms);
4180 }
4183 clone_parms);
4190 }
4191 }
4193 }
4194 }
4196 /* For each of the constructors and destructors in T, create an
4197 in-charge and not-in-charge variant. */
4199 static void
4201 {
4202 tree fns;
4204 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4205 out now. */
4213 }
4215 /* Remove all zero-width bit-fields from T. */
4217 static void
4219 {
4224 {
4229 else
4231 }
4232 }
4234 /* Returns TRUE iff we need a cookie when dynamically allocating an
4235 array whose elements have the indicated class TYPE. */
4237 static bool
4239 {
4240 tree fns;
4245 /* If there's a non-trivial destructor, we need a cookie. In order
4246 to iterate through the array calling the destructor for each
4247 element, we'll have to know how many elements there are. */
4251 /* If the usual deallocation function is a two-argument whose second
4252 argument is of type `size_t', then we have to pass the size of
4253 the array to the deallocation function, so we will need to store
4254 a cookie. */
4258 /* If there are no `operator []' members, or the lookup is
4259 ambiguous, then we don't need a cookie. */
4262 /* Loop through all of the functions. */
4264 {
4265 tree fn;
4266 tree second_parm;
4268 /* Select the current function. */
4270 /* See if this function is a one-argument delete function. If
4271 it is, then it will be the usual deallocation function. */
4275 /* Otherwise, if we have a two-argument function and the second
4276 argument is `size_t', it will be the usual deallocation
4277 function -- unless there is one-argument function, too. */
4281 }
4284 }
4286 /* Check the validity of the bases and members declared in T. Add any
4287 implicitly-generated functions (like copy-constructors and
4288 assignment operators). Compute various flag bits (like
4289 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4290 level: i.e., independently of the ABI in use. */
4292 static void
4294 {
4295 /* Nonzero if we are not allowed to generate a default constructor
4296 for this case. */
4298 /* Nonzero if the implicitly generated copy constructor should take
4299 a non-const reference argument. */
4301 /* Nonzero if the the implicitly generated assignment operator
4302 should take a non-const reference argument. */
4304 tree access_decls;
4306 /* By default, we use const reference arguments and generate default
4307 constructors. */
4312 /* Check all the base-classes. */
4316 /* Check all the data member declarations. */
4322 /* Check all the method declarations. */
4325 /* A nearly-empty class has to be vptr-containing; a nearly empty
4326 class contains just a vptr. */
4330 /* Do some bookkeeping that will guide the generation of implicitly
4331 declared member functions. */
4349 /* Synthesize any needed methods. Note that methods will be synthesized
4350 for anonymous unions; grok_x_components undoes that. */
4352 cant_have_const_ctor,
4353 no_const_asn_ref);
4355 /* Create the in-charge and not-in-charge variants of constructors
4356 and destructors. */
4359 /* Process the using-declarations. */
4363 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4366 /* Figure out whether or not we will need a cookie when dynamically
4367 allocating an array of this type. */
4370 }
4372 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4373 accordingly. If a new vfield was created (because T doesn't have a
4374 primary base class), then the newly created field is returned. It
4375 is not added to the TYPE_FIELDS list; it is the caller's
4376 responsibility to do that. Accumulate declared virtual functions
4377 on VIRTUALS_P. */
4379 static tree
4381 {
4382 tree fn;
4384 /* Collect the virtual functions declared in T. */
4388 {
4396 }
4398 /* If we couldn't find an appropriate base class, create a new field
4399 here. Even if there weren't any new virtual functions, we might need a
4400 new virtual function table if we're supposed to include vptrs in
4401 all classes that need them. */
4403 {
4404 /* We build this decl with vtbl_ptr_type_node, which is a
4405 `vtable_entry_type*'. It might seem more precise to use
4406 `vtable_entry_type (*)[N]' where N is the number of firtual
4407 functions. However, that would require the vtable pointer in
4408 base classes to have a different type than the vtable pointer
4409 in derived classes. We could make that happen, but that
4410 still wouldn't solve all the problems. In particular, the
4411 type-based alias analysis code would decide that assignments
4412 to the base class vtable pointer can't alias assignments to
4413 the derived class vtable pointer, since they have different
4414 types. Thus, in a derived class destructor, where the base
4415 class constructor was inlined, we could generate bad code for
4416 setting up the vtable pointer.
4418 Therefore, we use one type for all vtable pointers. We still
4419 use a type-correct type; it's just doesn't indicate the array
4420 bounds. That's better than using `void*' or some such; it's
4421 cleaner, and it let's the alias analysis code know that these
4422 stores cannot alias stores to void*! */
4423 tree field;
4436 /* This class is non-empty. */
4440 /* If there were any baseclasses, they can't possibly be at
4441 offset zero any more, because that's where the vtable
4442 pointer is. So, converting to a base class is going to
4443 take work. */
4447 }
4450 }
4452 /* Fixup the inline function given by INFO now that the class is
4453 complete. */
4455 static void
4457 {
4459 {
4462 {
4465 }
4466 }
4467 }
4469 /* Fixup the inline methods and friends in TYPE now that TYPE is
4470 complete. */
4472 static void
4474 {
4478 {
4483 else
4485 }
4487 /* Do inline member functions. */
4491 /* Do friends. */
4493 method;
4497 }
4499 /* Add OFFSET to all base types of BINFO which is a base in the
4500 hierarchy dominated by T.
4502 OFFSET, which is a type offset, is number of bytes. */
4504 static void
4506 {
4508 tree primary_binfo;
4510 /* Update BINFO's offset. */
4515 offset));
4517 /* Find the primary base class. */
4520 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4521 downwards. */
4523 {
4524 tree base_binfo;
4526 /* On the first time through the loop, do the primary base.
4527 Because the primary base need not be an immediate base, we
4528 must handle the primary base specially. */
4530 {
4535 }
4536 else
4537 {
4539 /* Don't do the primary base twice. */
4542 }
4544 /* Skip virtual bases that aren't our canonical primary base. */
4550 }
4551 }
4553 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4554 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4555 empty subobjects of T. */
4557 static void
4559 {
4560 tree vbase;
4569 {
4570 /* In G++ 3.2, we incorrectly rounded the size before laying out
4571 the virtual bases. */
4573 #ifdef STRUCTURE_SIZE_BOUNDARY
4574 /* Packed structures don't need to have minimum size. */
4577 #endif
4581 }
4583 /* Find the last field. The artificial fields created for virtual
4584 bases will go after the last extant field to date. */
4589 /* Go through the virtual bases, allocating space for each virtual
4590 base that is not already a primary base class. These are
4591 allocated in inheritance graph order. */
4593 {
4598 {
4601 /* This virtual base is not a primary base of any class in the
4602 hierarchy, so we have to add space for it. */
4606 /* If the first virtual base might have been placed at a
4607 lower address, had we started from CLASSTYPE_SIZE, rather
4608 than TYPE_SIZE, issue a warning. There can be both false
4609 positives and false negatives from this warning in rare
4610 cases; to deal with all the possibilities would probably
4611 require performing both layout algorithms and comparing
4612 the results which is not particularly tractable. */
4614 && first_vbase
4615 && (tree_int_cst_lt
4619 bitsize_unit_node),
4621 warning ("offset of virtual base `%T' is not ABI-compliant and may change in a future version of GCC",
4622 basetype);
4625 }
4626 }
4627 }
4629 /* Returns the offset of the byte just past the end of the base class
4630 BINFO. */
4632 static tree
4634 {
4635 tree size;
4638 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4639 allocate some space for it. It cannot have virtual bases, so
4640 TYPE_SIZE_UNIT is fine. */
4642 else
4646 }
4648 /* Returns the offset of the byte just past the end of the base class
4649 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4650 only non-virtual bases are included. */
4652 static tree
4654 {
4656 tree binfo;
4657 tree offset;
4661 {
4672 }
4674 /* G++ 3.2 did not check indirect virtual bases. */
4677 binfo;
4679 {
4683 }
4686 }
4688 /* Warn about bases of T that are inaccessible because they are
4689 ambiguous. For example:
4691 struct S {};
4692 struct T : public S {};
4693 struct U : public S, public T {};
4695 Here, `(S*) new U' is not allowed because there are two `S'
4696 subobjects of U. */
4698 static void
4700 {
4702 tree vbases;
4703 tree basetype;
4705 /* Check direct bases. */
4707 {
4713 }
4715 /* Check for ambiguous virtual bases. */
4718 vbases;
4720 {
4726 }
4727 }
4729 /* Compare two INTEGER_CSTs K1 and K2. */
4731 static int
4733 {
4735 }
4737 /* Increase the size indicated in RLI to account for empty classes
4738 that are "off the end" of the class. */
4740 static void
4742 {
4743 tree eoc;
4744 tree rli_size;
4746 /* It might be the case that we grew the class to allocate a
4747 zero-sized base class. That won't be reflected in RLI, yet,
4748 because we are willing to overlay multiple bases at the same
4749 offset. However, now we need to make sure that RLI is big enough
4750 to reflect the entire class. */
4756 {
4758 rli->bitpos
4767 }
4768 }
4770 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4771 BINFO_OFFSETs for all of the base-classes. Position the vtable
4772 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4774 static void
4776 {
4777 tree non_static_data_members;
4778 tree field;
4779 tree vptr;
4780 record_layout_info rli;
4781 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4782 types that appear at that offset. */
4783 splay_tree empty_base_offsets;
4784 /* True if the last field layed out was a bit-field. */
4786 /* The location at which the next field should be inserted. */
4788 /* T, as a base class. */
4789 tree base_t;
4791 /* Keep track of the first non-static data member. */
4794 /* Start laying out the record. */
4797 /* If possible, we reuse the virtual function table pointer from one
4798 of our base classes. */
4801 /* Create a pointer to our virtual function table. */
4804 /* The vptr is always the first thing in the class. */
4806 {
4811 }
4812 else
4815 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4820 /* Layout the non-static data members. */
4822 {
4823 tree type;
4824 tree padding;
4827 /* We still pass things that aren't non-static data members to
4828 the back-end, in case it wants to do something with them. */
4830 {
4832 /* If the static data member has incomplete type, keep track
4833 of it so that it can be completed later. (The handling
4834 of pending statics in finish_record_layout is
4835 insufficient; consider:
4837 struct S1;
4838 struct S2 { static S1 s1; };
4840 At this point, finish_record_layout will be called, but
4841 S1 is still incomplete.) */
4845 }
4849 /* If this field is a bit-field whose width is greater than its
4850 type, then there are some special rules for allocating
4851 it. */
4854 {
4855 integer_type_kind itk;
4856 tree integer_type;
4857 /* We must allocate the bits as if suitably aligned for the
4858 longest integer type that fits in this many bits. type
4859 of the field. Then, we are supposed to use the left over
4860 bits as additional padding. */
4866 /* ITK now indicates a type that is too large for the
4867 field. We have to back up by one to find the largest
4868 type that fits. */
4872 /* In a union, the padding field must have the full width
4873 of the bit-field; all fields start at offset zero. */
4875 else
4876 {
4879 "ABI-compliant and may change in a future "
4881 t);
4884 }
4885 #ifdef PCC_BITFIELD_TYPE_MATTERS
4886 /* An unnamed bitfield does not normally affect the
4887 alignment of the containing class on a target where
4888 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4889 make any exceptions for unnamed bitfields when the
4890 bitfields are longer than their types. Therefore, we
4891 temporarily give the field a name. */
4893 {
4896 }
4897 #endif
4901 }
4902 else
4906 empty_base_offsets);
4907 /* If the bit-field had no name originally, remove the name
4908 now. */
4912 /* Remember the location of any empty classes in FIELD. */
4916 empty_base_offsets,
4919 /* If a bit-field does not immediately follow another bit-field,
4920 and yet it starts in the middle of a byte, we have failed to
4921 comply with the ABI. */
4924 && !last_field_was_bitfield
4927 bitsize_unit_node)))
4928 cp_warning_at ("offset of `%D' is not ABI-compliant and may change in a future version of GCC",
4929 field);
4931 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4932 offset of the field. */
4938 "classes to be placed at different locations in a "
4940 field);
4942 /* If we needed additional padding after this field, add it
4943 now. */
4945 {
4946 tree padding_field;
4949 NULL_TREE,
4950 char_type_node);
4956 NULL_TREE,
4957 empty_base_offsets);
4958 }
4961 }
4964 {
4965 /* Make sure that we are on a byte boundary so that the size of
4966 the class without virtual bases will always be a round number
4967 of bytes. */
4970 }
4972 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4973 padding. */
4977 /* Delete all zero-width bit-fields from the list of fields. Now
4978 that the type is laid out they are no longer important. */
4981 /* Create the version of T used for virtual bases. We do not use
4982 make_aggr_type for this version; this is an artificial type. For
4983 a POD type, we just reuse T. */
4985 {
4988 /* Set the size and alignment for the new type. In G++ 3.2, all
4989 empty classes were considered to have size zero when used as
4990 base classes. */
4992 {
4998 t);
4999 }
5000 else
5001 {
5002 tree eoc;
5004 /* If the ABI version is not at least two, and the last
5005 field was a bit-field, RLI may not be on a byte
5006 boundary. In particular, rli_size_unit_so_far might
5007 indicate the last complete byte, while rli_size_so_far
5008 indicates the total number of bits used. Therefore,
5009 rli_size_so_far, rather than rli_size_unit_so_far, is
5010 used to compute TYPE_SIZE_UNIT. */
5018 eoc);
5025 }
5029 /* Copy the fields from T. */
5033 {
5042 }
5044 /* Record the base version of the type. */
5047 }
5048 else
5051 /* Every empty class contains an empty class. */
5055 /* Set the TYPE_DECL for this type to contain the right
5056 value for DECL_OFFSET, so that we can use it as part
5057 of a COMPONENT_REF for multiple inheritance. */
5060 /* Now fix up any virtual base class types that we left lying
5061 around. We must get these done before we try to lay out the
5062 virtual function table. As a side-effect, this will remove the
5063 base subobject fields. */
5066 /* Make sure that empty classes are reflected in RLI at this
5067 point. */
5070 /* Make sure not to create any structures with zero size. */
5075 /* Let the back-end lay out the type. */
5078 /* Warn about bases that can't be talked about due to ambiguity. */
5081 /* Clean up. */
5083 }
5085 /* Returns the virtual function with which the vtable for TYPE is
5086 emitted, or NULL_TREE if that heuristic is not applicable to TYPE. */
5088 static tree
5090 {
5091 tree method;
5094 || processing_template_decl
5107 }
5109 /* Perform processing required when the definition of T (a class type)
5110 is complete. */
5112 void
5114 {
5115 tree x;
5116 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5119 tree vfield;
5122 {
5125 else
5129 }
5131 /* If this type was previously laid out as a forward reference,
5132 make sure we lay it out again. */
5139 /* Make assumptions about the class; we'll reset the flags if
5140 necessary. */
5145 /* Do end-of-class semantic processing: checking the validity of the
5146 bases and members and add implicitly generated methods. */
5149 /* Find the key method */
5151 {
5154 /* If a polymorphic class has no key method, we may emit the vtable
5155 in every translation unit where the class definition appears. */
5158 }
5160 /* Layout the class itself. */
5163 /* Make sure that we get our own copy of the vfield FIELD_DECL. */
5166 {
5172 /* The vtable better be at the start. */
5181 }
5182 else
5187 /* If we created a new vtbl pointer for this class, add it to the
5188 list. */
5193 /* If necessary, create the primary vtable for this class. */
5195 {
5196 /* We must enter these virtuals into the table. */
5200 /* Here we know enough to change the type of our virtual
5201 function table, but we will wait until later this function. */
5203 }
5206 {
5208 tree fn;
5217 /* Add entries for virtual functions introduced by this class. */
5220 /* Set DECL_VINDEX for all functions declared in this class. */
5222 fn;
5224 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5226 {
5230 /* A thunk. We should never be calling this entry directly
5231 from this vtable -- we'd use the entry for the non
5232 thunk base function. */
5236 }
5237 }
5241 /* Complete the rtl for any static member objects of the type we're
5242 working on. */
5248 /* Done with FIELDS...now decide whether to sort these for
5249 faster lookups later.
5251 We use a small number because most searches fail (succeeding
5252 ultimately as the search bores through the inheritance
5253 hierarchy), and we want this failure to occur quickly. */
5257 {
5261 field_decl_cmp);
5265 }
5268 {
5273 /* Mark the fact that constructor for T could affect anybody
5274 inheriting from T who wants to initialize vtables for
5275 VFIELDS's type. */
5278 }
5280 /* Make the rtl for any new vtables we have created, and unmark
5281 the base types we marked. */
5284 /* Build the VTT for T. */
5300 /* Finish debugging output for this type. */
5302 }
5304 /* When T was built up, the member declarations were added in reverse
5305 order. Rearrange them to declaration order. */
5307 void
5309 {
5310 tree next;
5311 tree prev;
5312 tree x;
5314 /* The following lists are all in reverse order. Put them in
5315 declaration order now. */
5320 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5321 reverse order, so we can't just use nreverse. */
5326 {
5330 }
5332 {
5336 }
5337 }
5339 tree
5341 {
5345 /* Now that we've got all the field declarations, reverse everything
5346 as necessary. */
5351 /* Nadger the current location so that diagnostics point to the start of
5352 the struct, not the end. */
5357 {
5360 }
5361 else
5371 else
5378 }
5379 \f
5380 /* Return the dynamic type of INSTANCE, if known.
5381 Used to determine whether the virtual function table is needed
5382 or not.
5384 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5385 of our knowledge of its type. *NONNULL should be initialized
5386 before this function is called. */
5388 static tree
5390 {
5392 {
5396 else
5401 /* This is a call to a constructor, hence it's never zero. */
5403 {
5407 }
5411 /* This is a call to a constructor, hence it's never zero. */
5413 {
5417 }
5428 /* Propagate nonnull. */
5448 {
5452 }
5453 /* fall through... */
5458 {
5462 }
5464 {
5468 /* if we're in a ctor or dtor, we know our type. */
5472 {
5476 }
5477 }
5479 {
5480 /* Reference variables should be references to objects. */
5488 }
5493 }
5494 }
5496 /* Return nonzero if the dynamic type of INSTANCE is known, and
5497 equivalent to the static type. We also handle the case where
5498 INSTANCE is really a pointer. Return negative if this is a
5499 ctor/dtor. There the dynamic type is known, but this might not be
5500 the most derived base of the original object, and hence virtual
5501 bases may not be layed out according to this type.
5503 Used to determine whether the virtual function table is needed
5504 or not.
5506 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5507 of our knowledge of its type. *NONNULL should be initialized
5508 before this function is called. */
5510 int
5512 {
5524 }
5526 \f
5527 void
5529 {
5532 current_class_stack
5540 }
5542 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5543 appropriate for TYPE.
5545 If MODIFY is 1, we set IDENTIFIER_CLASS_VALUE's of names
5546 which can be seen locally to the class. They are shadowed by
5547 any subsequent local declaration (including parameter names).
5549 If MODIFY is 2, we set IDENTIFIER_CLASS_VALUE's of names
5550 which have static meaning (i.e., static members, static
5551 member functions, enum declarations, etc).
5553 If MODIFY is 3, we set IDENTIFIER_CLASS_VALUE of names
5554 which can be seen locally to the class (as in 1), but
5555 know that we are doing this for declaration purposes
5556 (i.e. friend foo::bar (int)).
5558 So that we may avoid calls to lookup_name, we cache the _TYPE
5559 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5561 For multiple inheritance, we perform a two-pass depth-first search
5562 of the type lattice. The first pass performs a pre-order search,
5563 marking types after the type has had its fields installed in
5564 the appropriate IDENTIFIER_CLASS_VALUE slot. The second pass merely
5565 unmarks the marked types. If a field or member function name
5566 appears in an ambiguous way, the IDENTIFIER_CLASS_VALUE of
5567 that name becomes `error_mark_node'. */
5569 void
5571 {
5574 /* Make sure there is enough room for the new entry on the stack. */
5576 {
5578 current_class_stack
5580 current_class_stack_size
5582 }
5584 /* Insert a new entry on the class stack. */
5589 current_class_depth++;
5591 /* Now set up the new type. */
5597 /* By default, things in classes are private, while things in
5598 structures or unions are public. */
5600 ? access_private_node
5607 {
5608 /* Forcibly remove any old class remnants. */
5610 }
5612 /* If we're about to enter a nested class, clear
5613 IDENTIFIER_CLASS_VALUE for the enclosing classes. */
5620 {
5623 else
5624 {
5625 tree item;
5627 /* We are re-entering the same class we just left, so we
5628 don't have to search the whole inheritance matrix to find
5629 all the decls to bind again. Instead, we install the
5630 cached class_shadowed list, and walk through it binding
5631 names and setting up IDENTIFIER_TYPE_VALUEs. */
5634 {
5641 }
5643 }
5646 }
5647 }
5649 /* When we exit a toplevel class scope, we save the
5650 IDENTIFIER_CLASS_VALUEs so that we can restore them quickly if we
5651 reenter the class. Here, we've entered some other class, so we
5652 must invalidate our cache. */
5654 void
5656 {
5657 tree t;
5659 /* The IDENTIFIER_CLASS_VALUEs are no longer valid. */
5665 }
5667 /* Get out of the current class scope. If we were in a class scope
5668 previously, that is the one popped to. */
5670 void
5672 {
5676 current_class_depth--;
5682 }
5684 /* Returns 1 if current_class_type is either T or a nested type of T.
5685 We start looking from 1 because entry 0 is from global scope, and has
5686 no type. */
5688 int
5690 {
5699 }
5701 /* If either current_class_type or one of its enclosing classes are derived
5702 from T, return the appropriate type. Used to determine how we found
5703 something via unqualified lookup. */
5705 tree
5707 {
5710 /* The bases of a dependent type are unknown. */
5722 }
5724 /* When entering a class scope, all enclosing class scopes' names with
5725 static meaning (static variables, static functions, types and
5726 enumerators) have to be visible. This recursive function calls
5727 pushclass for all enclosing class contexts until global or a local
5728 scope is reached. TYPE is the enclosed class. */
5730 void
5732 {
5733 tree context;
5735 /* A namespace might be passed in error cases, like A::B:C. */
5749 }
5751 /* Undoes a push_nested_class call. */
5753 void
5755 {
5761 }
5763 /* Returns the number of extern "LANG" blocks we are nested within. */
5765 int
5767 {
5769 }
5771 /* Set global variables CURRENT_LANG_NAME to appropriate value
5772 so that behavior of name-mangling machinery is correct. */
5774 void
5776 {
5780 {
5782 }
5784 {
5786 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5787 (See record_builtin_java_type in decl.c.) However, that causes
5788 incorrect debug entries if these types are actually used.
5789 So we re-enable debug output after extern "Java". */
5798 }
5800 {
5802 }
5803 else
5805 }
5807 /* Get out of the current language scope. */
5809 void
5811 {
5814 }
5815 \f
5816 /* Type instantiation routines. */
5818 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5819 matches the TARGET_TYPE. If there is no satisfactory match, return
5820 error_mark_node, and issue an error message if COMPLAIN is
5821 nonzero. Permit pointers to member function if PTRMEM is nonzero.
5822 If TEMPLATE_ONLY, the name of the overloaded function
5823 was a template-id, and EXPLICIT_TARGS are the explicitly provided
5824 template arguments. */
5826 static tree
5828 tree overload,
5832 tree explicit_targs)
5833 {
5834 /* Here's what the standard says:
5836 [over.over]
5838 If the name is a function template, template argument deduction
5839 is done, and if the argument deduction succeeds, the deduced
5840 arguments are used to generate a single template function, which
5841 is added to the set of overloaded functions considered.
5843 Non-member functions and static member functions match targets of
5844 type "pointer-to-function" or "reference-to-function." Nonstatic
5845 member functions match targets of type "pointer-to-member
5846 function;" the function type of the pointer to member is used to
5847 select the member function from the set of overloaded member
5848 functions. If a nonstatic member function is selected, the
5849 reference to the overloaded function name is required to have the
5850 form of a pointer to member as described in 5.3.1.
5852 If more than one function is selected, any template functions in
5853 the set are eliminated if the set also contains a non-template
5854 function, and any given template function is eliminated if the
5855 set contains a second template function that is more specialized
5856 than the first according to the partial ordering rules 14.5.5.2.
5857 After such eliminations, if any, there shall remain exactly one
5858 selected function. */
5862 /* We store the matches in a TREE_LIST rooted here. The functions
5863 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5864 interoperability with most_specialized_instantiation. */
5866 tree fn;
5868 /* By the time we get here, we should be seeing only real
5869 pointer-to-member types, not the internal POINTER_TYPE to
5870 METHOD_TYPE representation. */
5878 /* Check that the TARGET_TYPE is reasonable. */
5882 /* This is OK, too. */
5885 {
5886 /* This is OK, too. This comes from a conversion to reference
5887 type. */
5890 }
5891 else
5892 {
5898 }
5900 /* If we can find a non-template function that matches, we can just
5901 use it. There's no point in generating template instantiations
5902 if we're just going to throw them out anyhow. But, of course, we
5903 can only do this when we don't *need* a template function. */
5905 {
5906 tree fns;
5909 {
5911 tree fntype;
5914 /* We're not looking for templates just yet. */
5919 /* We're looking for a non-static member, and this isn't
5920 one, or vice versa. */
5923 /* See if there's a match. */
5932 }
5933 }
5935 /* Now, if we've already got a match (or matches), there's no need
5936 to proceed to the template functions. But, if we don't have a
5937 match we need to look at them, too. */
5939 {
5940 tree target_fn_type;
5941 tree target_arg_types;
5942 tree target_ret_type;
5943 tree fns;
5946 target_fn_type
5948 else
5953 /* Never do unification on the 'this' parameter. */
5958 {
5960 tree instantiation;
5961 tree instantiation_type;
5962 tree targs;
5965 /* We're only looking for templates. */
5970 /* We're not looking for a non-static member, and this is
5971 one, or vice versa. */
5974 /* Try to do argument deduction. */
5979 /* Argument deduction failed. */
5982 /* Instantiate the template. */
5986 /* Instantiation failed. */
5989 /* See if there's a match. */
5992 instantiation_type =
5998 }
6000 /* Now, remove all but the most specialized of the matches. */
6002 {
6007 }
6008 }
6010 /* Now we should have exactly one function in MATCHES. */
6012 {
6013 /* There were *no* matches. */
6015 {
6018 target_type);
6020 /* print_candidates expects a chain with the functions in
6021 TREE_VALUE slots, so we cons one up here (we're losing anyway,
6022 so why be clever?). */
6025 matches);
6028 }
6030 }
6032 {
6033 /* There were too many matches. */
6036 {
6037 tree match;
6041 target_type);
6043 /* Since print_candidates expects the functions in the
6044 TREE_VALUE slot, we flip them here. */
6049 }
6052 }
6054 /* Good, exactly one match. Now, convert it to the correct type. */
6059 {
6067 {
6070 }
6071 }
6076 else
6077 {
6078 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
6079 will mark the function as addressed, but here we must do it
6080 explicitly. */
6084 }
6085 }
6087 /* This function will instantiate the type of the expression given in
6088 RHS to match the type of LHSTYPE. If errors exist, then return
6089 error_mark_node. FLAGS is a bit mask. If ITF_COMPLAIN is set, then
6090 we complain on errors. If we are not complaining, never modify rhs,
6091 as overload resolution wants to try many possible instantiations, in
6092 the hope that at least one will work.
6094 For non-recursive calls, LHSTYPE should be a function, pointer to
6095 function, or a pointer to member function. */
6097 tree
6099 {
6108 {
6112 }
6115 {
6121 /* Microsoft allows `A::f' to be resolved to a
6122 pointer-to-member. */
6123 ;
6124 else
6125 {
6130 }
6131 }
6136 /* We don't overwrite rhs if it is an overloaded function.
6137 Copying it would destroy the tree link. */
6141 /* This should really only be used when attempting to distinguish
6142 what sort of a pointer to function we have. For now, any
6143 arithmetic operation which is not supported on pointers
6144 is rejected as an error. */
6147 {
6158 {
6159 tree new_rhs;
6169 }
6185 /* This can happen if we are forming a pointer-to-member for a
6186 member template. */
6189 /* Fall through. */
6192 {
6196 return
6198 fns,
6199 complain,
6200 allow_ptrmem,
6202 args);
6203 }
6207 return
6209 rhs,
6210 complain,
6211 allow_ptrmem,
6216 /* Now we should have a baselink. */
6222 /* This is too hard for now. */
6296 {
6300 }
6323 {
6328 }
6339 }
6340 }
6341 \f
6342 /* Return the name of the virtual function pointer field
6343 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6344 this may have to look back through base types to find the
6345 ultimate field name. (For single inheritance, these could
6346 all be the same name. Who knows for multiple inheritance). */
6348 static tree
6350 {
6365 }
6367 void
6369 {
6370 #ifdef GATHER_STATISTICS
6376 {
6381 }
6382 #endif
6383 }
6385 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6386 according to [class]:
6387 The class-name is also inserted
6388 into the scope of the class itself. For purposes of access checking,
6389 the inserted class name is treated as if it were a public member name. */
6391 void
6393 {
6396 tree saved_cas;
6409 }
6411 /* Returns 1 if TYPE contains only padding bytes. */
6413 int
6415 {
6422 /* In G++ 3.2, whether or not a class was empty was determined by
6423 looking at its size. */
6426 else
6428 }
6430 /* Returns true if TYPE contains an empty class. */
6432 static bool
6434 {
6438 {
6439 tree field;
6450 }
6454 }
6456 /* Find the enclosing class of the given NODE. NODE can be a *_DECL or
6457 a *_TYPE node. NODE can also be a local class. */
6459 tree
6461 {
6465 {
6467 {
6480 }
6481 }
6483 }
6485 /* Return 1 if TYPE or one of its enclosing classes is derived from BASE. */
6487 int
6489 {
6491 {
6496 }
6498 }
6500 /* Note that NAME was looked up while the current class was being
6501 defined and that the result of that lookup was DECL. */
6503 void
6505 {
6506 splay_tree names_used;
6508 /* If we're not defining a class, there's nothing to do. */
6512 /* If there's already a binding for this NAME, then we don't have
6513 anything to worry about. */
6525 }
6527 /* Note that NAME was declared (as DECL) in the current class. Check
6528 to see that the declaration is valid. */
6530 void
6532 {
6533 splay_tree names_used;
6534 splay_tree_node n;
6536 /* Look to see if we ever used this name. */
6537 names_used
6544 {
6545 /* [basic.scope.class]
6547 A name N used in a class S shall refer to the same declaration
6548 in its context and when re-evaluated in the completed scope of
6549 S. */
6554 }
6555 }
6557 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6558 Secondary vtables are merged with primary vtables; this function
6559 will return the VAR_DECL for the primary vtable. */
6561 tree
6563 {
6564 tree decl;
6568 {
6572 }
6576 }
6579 /* Returns the binfo for the primary base of BINFO. If the resulting
6580 BINFO is a virtual base, and it is inherited elsewhere in the
6581 hierarchy, then the returned binfo might not be the primary base of
6582 BINFO in the complete object. Check BINFO_PRIMARY_P or
6583 BINFO_LOST_PRIMARY_P to be sure. */
6585 tree
6587 {
6588 tree primary_base;
6589 tree result;
6597 }
6599 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6601 static int
6603 {
6607 }
6609 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6610 INDENT should be zero when called from the top level; it is
6611 incremented recursively. IGO indicates the next expected BINFO in
6612 inheritance graph ordering. */
6614 static tree
6617 tree binfo,
6618 tree igo,
6620 {
6622 tree base_binfos;
6629 {
6632 }
6647 {
6651 TFF_PLAIN_IDENTIFIER),
6653 }
6655 {
6658 }
6663 {
6667 {
6671 TFF_PLAIN_IDENTIFIER));
6672 }
6674 {
6678 TFF_PLAIN_IDENTIFIER));
6679 }
6681 {
6685 TFF_PLAIN_IDENTIFIER));
6686 }
6688 {
6692 TFF_PLAIN_IDENTIFIER));
6693 }
6697 }
6701 {
6706 {
6711 }
6712 }
6715 }
6717 /* Dump the BINFO hierarchy for T. */
6719 static void
6721 {
6740 }
6742 static void
6744 {
6745 tree inits;
6747 HOST_WIDE_INT elt;
6755 TFF_PLAIN_IDENTIFIER));
6762 }
6764 static void
6766 {
6774 {
6781 {
6785 }
6789 }
6792 }
6794 static void
6796 {
6804 {
6809 }
6812 }
6814 /* Virtual function table initialization. */
6816 /* Create all the necessary vtables for T and its base classes. */
6818 static void
6820 {
6821 tree list;
6822 tree vbase;
6824 /* We lay out the primary and secondary vtables in one contiguous
6825 vtable. The primary vtable is first, followed by the non-virtual
6826 secondary vtables in inheritance graph order. */
6831 /* Then come the virtual bases, also in inheritance graph order. */
6833 {
6837 }
6841 }
6843 /* Initialize the vtable for BINFO with the INITS. */
6845 static void
6847 {
6848 tree decl;
6854 }
6856 /* Initialize DECL (a declaration for a namespace-scope array) with
6857 the INITS. */
6859 static void
6861 {
6862 tree context;
6870 }
6872 /* Build the VTT (virtual table table) for T.
6873 A class requires a VTT if it has virtual bases.
6875 This holds
6876 1 - primary virtual pointer for complete object T
6877 2 - secondary VTTs for each direct non-virtual base of T which requires a
6878 VTT
6879 3 - secondary virtual pointers for each direct or indirect base of T which
6880 has virtual bases or is reachable via a virtual path from T.
6881 4 - secondary VTTs for each direct or indirect virtual base of T.
6883 Secondary VTTs look like complete object VTTs without part 4. */
6885 static void
6887 {
6888 tree inits;
6889 tree type;
6890 tree vtt;
6891 tree index;
6893 /* Build up the initializers for the VTT. */
6898 /* If we didn't need a VTT, we're done. */
6902 /* Figure out the type of the VTT. */
6906 /* Now, build the VTT object itself. */
6909 /* Add the VTT to the vtables list. */
6914 }
6916 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6917 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6918 and CHAIN the vtable pointer for this binfo after construction is
6919 complete. VALUE can also be another BINFO, in which case we recurse. */
6921 static tree
6923 {
6924 tree vt;
6927 {
6933 else
6935 }
6938 }
6940 /* Recursively build the VTT-initializer for BINFO (which is in the
6941 hierarchy dominated by T). INITS points to the end of the initializer
6942 list to date. INDEX is the VTT index where the next element will be
6943 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6944 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
6945 for virtual bases of T. When it is not so, we build the constructor
6946 vtables for the BINFO-in-T variant. */
6950 {
6952 tree b;
6953 tree init;
6954 tree secondary_vptrs;
6957 /* We only need VTTs for subobjects with virtual bases. */
6961 /* We need to use a construction vtable if this is not the primary
6962 VTT. */
6964 {
6967 /* Record the offset in the VTT where this sub-VTT can be found. */
6969 }
6971 /* Add the address of the primary vtable for the complete object. */
6976 {
6979 }
6982 /* Recursively add the secondary VTTs for non-virtual bases. */
6984 {
6989 }
6991 /* Add secondary virtual pointers for all subobjects of BINFO with
6992 either virtual bases or reachable along a virtual path, except
6993 subobjects that are non-virtual primary bases. */
7000 dfs_build_secondary_vptr_vtt_inits,
7001 NULL,
7002 dfs_ctor_vtable_bases_queue_p,
7003 secondary_vptrs);
7006 secondary_vptrs);
7010 /* The secondary vptrs come back in reverse order. After we reverse
7011 them, and add the INITS, the last init will be the first element
7012 of the chain. */
7015 {
7019 }
7021 /* Add the secondary VTTs for virtual bases. */
7024 {
7029 }
7032 {
7038 dfs_ctor_vtable_bases_queue_p,
7039 data);
7040 }
7043 }
7045 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo
7046 for the base in most derived. DATA is a TREE_LIST who's
7047 TREE_CHAIN is the type of the base being
7048 constructed whilst this secondary vptr is live. The TREE_UNSIGNED
7049 flag of DATA indicates that this is a constructor vtable. The
7050 TREE_TOP_LEVEL flag indicates that this is the primary VTT. */
7052 static tree
7054 {
7055 tree l;
7056 tree t;
7057 tree init;
7058 tree index;
7067 /* We don't care about bases that don't have vtables. */
7071 /* We're only interested in proper subobjects of T. */
7075 /* We're not interested in non-virtual primary bases. */
7079 /* If BINFO has virtual bases or is reachable via a virtual path
7080 from T, it'll have a secondary vptr. */
7085 /* Record the index where this secondary vptr can be found. */
7088 {
7091 }
7095 /* Add the initializer for the secondary vptr itself. */
7097 {
7098 /* It's a primary virtual base, and this is not the construction
7099 vtable. Find the base this is primary of in the inheritance graph,
7100 and use that base's vtable now. */
7103 }
7108 }
7110 /* dfs_walk_real predicate for building vtables. DATA is a TREE_LIST,
7111 VTT_MARKED_BINFO_P indicates whether marked or unmarked bases
7112 should be walked. TREE_PURPOSE is the TREE_TYPE that dominates the
7113 hierarchy. */
7115 static tree
7118 {
7124 }
7126 /* Called from build_vtt_inits via dfs_walk. After building constructor
7127 vtables and generating the sub-vtt from them, we need to restore the
7128 BINFO_VTABLES that were scribbled on. DATA is a TREE_LIST whose
7129 TREE_VALUE is the TREE_TYPE of the base whose sub vtt was generated. */
7131 static tree
7133 {
7136 /* We don't care about bases that don't have vtables. */
7140 /* If we scribbled the construction vtable vptr into BINFO, clear it
7141 out now. */
7149 }
7151 /* Build the construction vtable group for BINFO which is in the
7152 hierarchy dominated by T. */
7154 static void
7156 {
7157 tree list;
7158 tree type;
7159 tree vtbl;
7160 tree inits;
7161 tree id;
7162 tree vbase;
7164 /* See if we've already created this construction vtable group. */
7170 /* Build a version of VTBL (with the wrong type) for use in
7171 constructing the addresses of secondary vtables in the
7172 construction vtable group. */
7178 /* Add the vtables for each of our virtual bases using the vbase in T
7179 binfo. */
7181 vbase;
7183 {
7184 tree b;
7191 }
7194 /* Figure out the type of the construction vtable. */
7199 /* Initialize the construction vtable. */
7203 }
7205 /* Add the vtbl initializers for BINFO (and its bases other than
7206 non-virtual primaries) to the list of INITS. BINFO is in the
7207 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7208 the constructor the vtbl inits should be accumulated for. (If this
7209 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7210 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7211 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7212 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7213 but are not necessarily the same in terms of layout. */
7215 static void
7217 tree orig_binfo,
7218 tree rtti_binfo,
7219 tree t,
7220 tree inits)
7221 {
7229 /* If it doesn't have a vptr, we don't do anything. */
7233 /* If we're building a construction vtable, we're not interested in
7234 subobjects that don't require construction vtables. */
7240 /* Build the initializers for the BINFO-in-T vtable. */
7246 /* Walk the BINFO and its bases. We walk in preorder so that as we
7247 initialize each vtable we can figure out at what offset the
7248 secondary vtable lies from the primary vtable. We can't use
7249 dfs_walk here because we need to iterate through bases of BINFO
7250 and RTTI_BINFO simultaneously. */
7252 {
7255 /* Skip virtual bases. */
7261 inits);
7262 }
7263 }
7265 /* Called from accumulate_vtbl_inits. Returns the initializers for
7266 the BINFO vtable. */
7268 static tree
7270 tree orig_binfo,
7271 tree rtti_binfo,
7272 tree t,
7273 tree l)
7274 {
7281 {
7282 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7283 primary virtual base. If it is not the same primary in
7284 the hierarchy of T, we'll need to generate a ctor vtable
7285 for it, to place at its location in T. If it is the same
7286 primary, we still need a VTT entry for the vtable, but it
7287 should point to the ctor vtable for the base it is a
7288 primary for within the sub-hierarchy of RTTI_BINFO.
7290 There are three possible cases:
7292 1) We are in the same place.
7293 2) We are a primary base within a lost primary virtual base of
7294 RTTI_BINFO.
7295 3) We are primary to something not a base of RTTI_BINFO. */
7300 /* First, look through the bases we are primary to for RTTI_BINFO
7301 or a virtual base. */
7303 {
7307 }
7308 /* If we run out of primary links, keep looking down our
7309 inheritance chain; we might be an indirect primary. */
7315 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7316 base B and it is a base of RTTI_BINFO, this is case 2. In
7317 either case, we share our vtable with LAST, i.e. the
7318 derived-most base within B of which we are a primary. */
7322 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7323 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7324 binfo_ctor_vtable after everything's been set up. */
7327 /* Otherwise, this is case 3 and we get our own. */
7328 }
7333 {
7334 tree index;
7337 /* Compute the initializer for this vtable. */
7341 /* Figure out the position to which the VPTR should point. */
7344 vtbl_ptr_type_node,
7345 vtbl);
7352 index);
7355 }
7358 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7359 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7360 straighten this out. */
7364 else
7365 /* For an ordinary vtable, set BINFO_VTABLE. */
7369 }
7371 /* Construct the initializer for BINFO's virtual function table. BINFO
7372 is part of the hierarchy dominated by T. If we're building a
7373 construction vtable, the ORIG_BINFO is the binfo we should use to
7374 find the actual function pointers to put in the vtable - but they
7375 can be overridden on the path to most-derived in the graph that
7376 ORIG_BINFO belongs. Otherwise,
7377 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7378 BINFO that should be indicated by the RTTI information in the
7379 vtable; it will be a base class of T, rather than T itself, if we
7380 are building a construction vtable.
7382 The value returned is a TREE_LIST suitable for wrapping in a
7383 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7384 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7385 number of non-function entries in the vtable.
7387 It might seem that this function should never be called with a
7388 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7389 base is always subsumed by a derived class vtable. However, when
7390 we are building construction vtables, we do build vtables for
7391 primary bases; we need these while the primary base is being
7392 constructed. */
7394 static tree
7396 tree orig_binfo,
7397 tree t,
7398 tree rtti_binfo,
7400 {
7402 tree vfun_inits;
7403 tree vbase;
7404 vtbl_init_data vid;
7406 /* Initialize VID. */
7415 /* The first vbase or vcall offset is at index -3 in the vtable. */
7418 /* Add entries to the vtable for RTTI. */
7421 /* Create an array for keeping track of the functions we've
7422 processed. When we see multiple functions with the same
7423 signature, we share the vcall offsets. */
7425 /* Add the vcall and vbase offset entries. */
7427 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7428 build_vbase_offset_vtbl_entries. */
7430 vbase;
7434 /* If the target requires padding between data entries, add that now. */
7436 {
7440 {
7447 null_pointer_node),
7448 add);
7450 }
7451 }
7456 /* Go through all the ordinary virtual functions, building up
7457 initializers. */
7460 {
7461 tree delta;
7462 tree vcall_index;
7469 {
7473 }
7475 /* If the only definition of this function signature along our
7476 primary base chain is from a lost primary, this vtable slot will
7477 never be used, so just zero it out. This is important to avoid
7478 requiring extra thunks which cannot be generated with the function.
7480 We first check this in update_vtable_entry_for_fn, so we handle
7481 restored primary bases properly; we also need to do it here so we
7482 zero out unused slots in ctor vtables, rather than filling themff
7483 with erroneous values (though harmless, apart from relocation
7484 costs). */
7486 {
7487 /* We found a defn before a lost primary; go ahead as normal. */
7491 /* The nearest definition is from a lost primary; clear the
7492 slot. */
7494 {
7497 }
7498 }
7501 {
7502 /* Pull the offset for `this', and the function to call, out of
7503 the list. */
7510 /* You can't call an abstract virtual function; it's abstract.
7511 So, we replace these functions with __pure_virtual. */
7515 {
7519 }
7520 /* Take the address of the function, considering it to be of an
7521 appropriate generic type. */
7523 /* The address of a function can't change. */
7525 }
7527 /* And add it to the chain of initializers. */
7529 {
7534 else
7536 {
7543 }
7544 }
7545 else
7547 }
7549 /* The initializers for virtual functions were built up in reverse
7550 order; straighten them out now. */
7553 /* The negative offset initializers are also in reverse order. */
7556 /* Chain the two together. */
7558 }
7560 /* Adds to vid->inits the initializers for the vbase and vcall
7561 offsets in BINFO, which is in the hierarchy dominated by T. */
7563 static void
7565 {
7566 tree b;
7568 /* If this is a derived class, we must first create entries
7569 corresponding to the primary base class. */
7574 /* Add the vbase entries for this base. */
7576 /* Add the vcall entries for this base. */
7578 }
7580 /* Returns the initializers for the vbase offset entries in the vtable
7581 for BINFO (which is part of the class hierarchy dominated by T), in
7582 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7583 where the next vbase offset will go. */
7585 static void
7587 {
7588 tree vbase;
7589 tree t;
7590 tree non_primary_binfo;
7592 /* If there are no virtual baseclasses, then there is nothing to
7593 do. */
7599 /* We might be a primary base class. Go up the inheritance hierarchy
7600 until we find the most derived class of which we are a primary base:
7601 it is the offset of that which we need to use. */
7604 {
7605 tree b;
7607 /* If we have reached a virtual base, then it must be a primary
7608 base (possibly multi-level) of vid->binfo, or we wouldn't
7609 have called build_vcall_and_vbase_vtbl_entries for it. But it
7610 might be a lost primary, so just skip down to vid->binfo. */
7612 {
7615 }
7621 }
7623 /* Go through the virtual bases, adding the offsets. */
7625 vbase;
7627 {
7628 tree b;
7629 tree delta;
7634 /* Find the instance of this virtual base in the complete
7635 object. */
7638 /* If we've already got an offset for this virtual base, we
7639 don't need another one. */
7644 /* Figure out where we can find this vbase offset. */
7653 {
7654 /* The vbase offset had better be the same. */
7658 }
7660 /* The next vbase will come at a more negative offset. */
7664 /* The initializer is the delta from BINFO to this virtual base.
7665 The vbase offsets go in reverse inheritance-graph order, and
7666 we are walking in inheritance graph order so these end up in
7667 the right order. */
7673 vtable_entry_type,
7674 delta)));
7676 }
7677 }
7679 /* Adds the initializers for the vcall offset entries in the vtable
7680 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7681 to VID->INITS. */
7683 static void
7685 {
7686 /* We only need these entries if this base is a virtual base. We
7687 compute the indices -- but do not add to the vtable -- when
7688 building the main vtable for a class. */
7690 {
7691 /* We need a vcall offset for each of the virtual functions in this
7692 vtable. For example:
7694 class A { virtual void f (); };
7695 class B1 : virtual public A { virtual void f (); };
7696 class B2 : virtual public A { virtual void f (); };
7697 class C: public B1, public B2 { virtual void f (); };
7699 A C object has a primary base of B1, which has a primary base of A. A
7700 C also has a secondary base of B2, which no longer has a primary base
7701 of A. So the B2-in-C construction vtable needs a secondary vtable for
7702 A, which will adjust the A* to a B2* to call f. We have no way of
7703 knowing what (or even whether) this offset will be when we define B2,
7704 so we store this "vcall offset" in the A sub-vtable and look it up in
7705 a "virtual thunk" for B2::f.
7707 We need entries for all the functions in our primary vtable and
7708 in our non-virtual bases' secondary vtables. */
7710 /* If we are just computing the vcall indices -- but do not need
7711 the actual entries -- not that. */
7714 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7716 }
7717 }
7719 /* Build vcall offsets, starting with those for BINFO. */
7721 static void
7723 {
7725 tree primary_binfo;
7727 /* Don't walk into virtual bases -- except, of course, for the
7728 virtual base for which we are building vcall offsets. Any
7729 primary virtual base will have already had its offsets generated
7730 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7734 /* If BINFO has a primary base, process it first. */
7739 /* Add BINFO itself to the list. */
7742 /* Scan the non-primary bases of BINFO. */
7744 {
7745 tree base_binfo;
7750 }
7751 }
7753 /* Called from build_vcall_offset_vtbl_entries_r. */
7755 static void
7757 {
7758 /* Make entries for the rest of the virtuals. */
7760 {
7761 tree orig_fn;
7763 /* The ABI requires that the methods be processed in declaration
7764 order. G++ 3.2 used the order in the vtable. */
7766 orig_fn;
7770 }
7771 else
7772 {
7773 tree derived_virtuals;
7774 tree base_virtuals;
7775 tree orig_virtuals;
7776 /* If BINFO is a primary base, the most derived class which has
7777 BINFO as a primary base; otherwise, just BINFO. */
7778 tree non_primary_binfo;
7780 /* We might be a primary base class. Go up the inheritance hierarchy
7781 until we find the most derived class of which we are a primary base:
7782 it is the BINFO_VIRTUALS there that we need to consider. */
7785 {
7786 tree b;
7788 /* If we have reached a virtual base, then it must be vid->vbase,
7789 because we ignore other virtual bases in
7790 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7791 base (possibly multi-level) of vid->binfo, or we wouldn't
7792 have called build_vcall_and_vbase_vtbl_entries for it. But it
7793 might be a lost primary, so just skip down to vid->binfo. */
7795 {
7800 }
7806 }
7809 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7810 where rtti_binfo is the most derived type. */
7811 non_primary_binfo
7817 base_virtuals;
7821 {
7822 tree orig_fn;
7824 /* Find the declaration that originally caused this function to
7825 be present in BINFO_TYPE (binfo). */
7828 /* When processing BINFO, we only want to generate vcall slots for
7829 function slots introduced in BINFO. So don't try to generate
7830 one if the function isn't even defined in BINFO. */
7835 }
7836 }
7837 }
7839 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7841 static void
7843 {
7845 tree vcall_offset;
7847 /* If there is already an entry for a function with the same
7848 signature as FN, then we do not need a second vcall offset.
7849 Check the list of functions already present in the derived
7850 class vtable. */
7852 {
7853 tree derived_entry;
7857 /* We only use one vcall offset for virtual destructors,
7858 even though there are two virtual table entries. */
7862 }
7864 /* If we are building these vcall offsets as part of building
7865 the vtable for the most derived class, remember the vcall
7866 offset. */
7872 /* The next vcall offset will be found at a more negative
7873 offset. */
7877 /* Keep track of this function. */
7881 {
7882 tree base;
7883 tree fn;
7885 /* Find the overriding function. */
7889 integer_zero_node);
7890 else
7891 {
7894 /* The vbase we're working on is a primary base of
7895 vid->binfo. But it might be a lost primary, so its
7896 BINFO_OFFSET might be wrong, so we just use the
7897 BINFO_OFFSET from vid->binfo. */
7901 vcall_offset));
7902 }
7903 /* Add the intiailizer to the vtable. */
7906 }
7907 }
7909 /* Return vtbl initializers for the RTTI entries coresponding to the
7910 BINFO's vtable. The RTTI entries should indicate the object given
7911 by VID->rtti_binfo. */
7913 static void
7915 {
7916 tree b;
7917 tree t;
7918 tree basetype;
7919 tree offset;
7920 tree decl;
7921 tree init;
7926 /* To find the complete object, we will first convert to our most
7927 primary base, and then add the offset in the vtbl to that value. */
7931 {
7932 tree primary_base;
7937 }
7940 /* The second entry is the address of the typeinfo object. */
7943 else
7946 /* Convert the declaration to a type that can be stored in the
7947 vtable. */
7952 /* Add the offset-to-top entry. It comes earlier in the vtable that
7953 the the typeinfo entry. Convert the offset to look like a
7954 function pointer, so that we can put it in the vtable. */
7958 }