| blob | 33ece0dbe2fc22f44bdc542332e727630a891d3a |
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. */
534 /* At one time the vtable info was grabbed 2 words at a time. This
535 fails on sparc unless you have 8-byte alignment. (tiemann) */
542 }
544 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
545 or even complete. If this does not exist, create it. If COMPLETE is
546 nonzero, then complete the definition of it -- that will render it
547 impossible to actually build the vtable, but is useful to get at those
548 which are known to exist in the runtime. */
550 tree
552 {
553 tree decl;
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 /* Make BINFO's vtable have N entries, including RTTI entries,
1928 vbase and vcall offsets, etc. Set its type and call the backend
1929 to lay it out. */
1931 static void
1933 {
1934 tree atype;
1935 tree vtable;
1941 /* We may have to grow the vtable. */
1944 {
1948 }
1949 }
1951 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1952 have the same signature. */
1954 int
1956 {
1957 /* One destructor overrides another if they are the same kind of
1958 destructor. */
1962 /* But a non-destructor never overrides a destructor, nor vice
1963 versa, nor do different kinds of destructors override
1964 one-another. For example, a complete object destructor does not
1965 override a deleting destructor. */
1970 {
1978 }
1980 }
1982 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1983 subobject. */
1985 static bool
1987 {
1988 tree probe;
1991 {
1995 /* If we meet a virtual base, we can't follow the inheritance
1996 any more. See if the complete type of DERIVED contains
1997 such a virtual base. */
2001 }
2003 }
2006 /* The function for which we are trying to find a final overrider. */
2007 tree fn;
2008 /* The base class in which the function was declared. */
2009 tree declaring_base;
2010 /* The most derived class in the hierarchy. */
2011 tree most_derived_type;
2012 /* The candidate overriders. */
2013 tree candidates;
2014 /* Binfos which inherited virtually on the currrent path. */
2015 tree vpath;
2018 /* Called from find_final_overrider via dfs_walk. */
2020 static tree
2022 {
2026 {
2027 /* We've found a path to the declaring base. Walk the path from
2028 derived to base, looking for an overrider for FN. */
2031 /* Build the path, using the inheritance chain and record of
2032 virtual inheritance. */
2034 {
2039 {
2042 }
2043 else
2045 }
2046 /* Now walk path, looking for overrides. */
2048 {
2049 tree method = look_for_overrides_here
2053 {
2057 /* Remove any candidates overridden by this new function. */
2059 {
2060 /* If *CANDIDATE overrides METHOD, then METHOD
2061 cannot override anything else on the list. */
2064 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2067 else
2069 }
2071 /* Add the new function. */
2074 }
2075 }
2076 }
2079 }
2081 static tree
2083 {
2091 }
2093 static tree
2095 {
2102 }
2104 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2105 FN and whose TREE_VALUE is the binfo for the base where the
2106 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2107 DERIVED) is the base object in which FN is declared. */
2109 static tree
2111 {
2112 find_final_overrider_data ffod;
2114 /* Getting this right is a little tricky. This is valid:
2116 struct S { virtual void f (); };
2117 struct T { virtual void f (); };
2118 struct U : public S, public T { };
2120 even though calling `f' in `U' is ambiguous. But,
2122 struct R { virtual void f(); };
2123 struct S : virtual public R { virtual void f (); };
2124 struct T : virtual public R { virtual void f (); };
2125 struct U : public S, public T { };
2127 is not -- there's no way to decide whether to put `S::f' or
2128 `T::f' in the vtable for `R'.
2130 The solution is to look at all paths to BINFO. If we find
2131 different overriders along any two, then there is a problem. */
2142 dfs_find_final_overrider,
2143 dfs_find_final_overrider_post,
2144 dfs_find_final_overrider_q,
2147 /* If there was no winner, issue an error message. */
2149 {
2153 }
2156 }
2158 /* Return the index of the vcall offset for FN when TYPE is used as a
2159 virtual base. */
2161 static tree
2163 {
2164 tree v;
2171 /* There should always be an appropriate index. */
2175 }
2177 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2178 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2179 corresponding position in the BINFO_VIRTUALS list. */
2181 static void
2184 {
2185 tree b;
2186 tree overrider;
2187 tree delta;
2188 tree virtual_base;
2189 tree first_defn;
2195 /* Find the nearest primary base (possibly binfo itself) which defines
2196 this function; this is the class the caller will convert to when
2197 calling FN through BINFO. */
2199 {
2204 /* The nearest definition is from a lost primary. */
2207 }
2210 /* Find the final overrider. */
2216 /* Check for adjusting covariant return types. */
2224 {
2225 /* If FN is a covariant thunk, we must figure out the adjustment
2226 to the final base FN was converting to. As OVERRIDER_TARGET might
2227 also be converting to the return type of FN, we have to
2228 combine the two conversions here. */
2232 {
2235 }
2236 else
2240 {
2241 /* There was no existing virtual thunk (which takes
2242 precidence). */
2243 tree thunk_binfo;
2244 base_kind kind;
2252 {
2256 {
2257 /* We convert via virtual base. Find the virtual
2258 base and adjust the fixed offset to be from there. */
2265 }
2267 /* There was an existing fixed offset, this must be
2268 from the base just converted to, and the base the
2269 FN was thunking to. */
2271 else
2273 }
2274 }
2277 /* Replace the overriding function with a covariant thunk. We
2278 will emit the overriding function in its own slot as
2279 well. */
2282 }
2283 else
2286 /* Assume that we will produce a thunk that convert all the way to
2287 the final overrider, and not to an intermediate virtual base. */
2290 /* See if we can convert to an intermediate virtual base first, and then
2291 use the vcall offset located there to finish the conversion. */
2293 {
2294 /* If we find the final overrider, then we can stop
2295 walking. */
2300 /* If we find a virtual base, and we haven't yet found the
2301 overrider, then there is a virtual base between the
2302 declaring base (first_defn) and the final overrider. */
2304 {
2307 }
2308 }
2311 {
2312 /* The ABI specifies that a covariant thunk includes a mangling
2313 for a this pointer adjustment. This-adjusting thunks that
2314 override a function from a virtual base have a vcall
2315 adjustment. When the virtual base in question is a primary
2316 virtual base, we know the adjustments are zero, (and in the
2317 non-covariant case, we would not use the thunk).
2318 Unfortunately we didn't notice this could happen, when
2319 designing the ABI and so never mandated that such a covariant
2320 thunk should be emitted. Because we must use the ABI mandated
2321 name, we must continue searching from the binfo where we
2322 found the most recent definition of the function, towards the
2323 primary binfo which first introduced the function into the
2324 vtable. If that enters a virtual base, we must use a vcall
2325 this-adjusting thunk. Bleah! */
2326 tree probe;
2329 {
2334 }
2336 /* Even if we find a virtual base, the correct delta is
2337 between the overrider and the binfo we're building a vtable
2338 for. */
2340 }
2342 /* Compute the constant adjustment to the `this' pointer. The
2343 `this' pointer, when this function is called, will point at BINFO
2344 (or one of its primary bases, which are at the same offset). */
2346 /* The `this' pointer needs to be adjusted from the declaration to
2347 the nearest virtual base. */
2351 /* If the nearest definition is in a lost primary, we don't need an
2352 entry in our vtable. Except possibly in a constructor vtable,
2353 if we happen to get our primary back. In that case, the offset
2354 will be zero, as it will be a primary base. */
2356 else
2357 /* The `this' pointer needs to be adjusted from pointing to
2358 BINFO to pointing at the base where the final overrider
2359 appears. */
2360 virtual_covariant:
2369 }
2371 /* Called from modify_all_vtables via dfs_walk. */
2373 static tree
2375 {
2377 primary base; we're not going to use that vtable anyhow.
2378 We do still need to do this for virtual primary bases, as they
2379 could become non-primary in a construction vtable. */
2381 /* Similarly, a base without a vtable needs no modification. */
2383 {
2385 tree virtuals;
2386 tree old_virtuals;
2391 /* Now, go through each of the virtual functions in the virtual
2392 function table for BINFO. Find the final overrider, and
2393 update the BINFO_VIRTUALS list appropriately. */
2396 virtuals;
2400 binfo,
2403 }
2408 }
2410 /* Update all of the primary and secondary vtables for T. Create new
2411 vtables as required, and initialize their RTTI information. Each
2412 of the functions in VIRTUALS is declared in T and may override a
2413 virtual function from a base class; find and modify the appropriate
2414 entries to point to the overriding functions. Returns a list, in
2415 declaration order, of the virtual functions that are declared in T,
2416 but do not appear in the primary base class vtable, and which
2417 should therefore be appended to the end of the vtable for T. */
2419 static tree
2421 {
2425 /* Update all of the vtables. */
2429 /* Add virtual functions not already in our primary vtable. These
2430 will be both those introduced by this class, and those overridden
2431 from secondary bases. It does not include virtuals merely
2432 inherited from secondary bases. */
2434 {
2439 {
2440 /* We don't need to adjust the `this' pointer when
2441 calling this function. */
2445 /* This is a function not already in our vtable. Keep it. */
2447 }
2448 else
2449 /* We've already got an entry for this function. Skip it. */
2451 }
2454 }
2456 /* Get the base virtual function declarations in T that have the
2457 indicated NAME. */
2459 static tree
2461 {
2462 tree methods;
2467 /* Find virtual functions in T with the indicated NAME. */
2471 methods;
2473 {
2479 }
2485 {
2488 base_fndecls);
2489 }
2492 }
2494 /* If this declaration supersedes the declaration of
2495 a method declared virtual in the base class, then
2496 mark this field as being virtual as well. */
2498 static void
2500 {
2502 /* In [temp.mem] we have:
2504 A specialization of a member function template does not
2505 override a virtual function from a base class. */
2511 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2512 the error_mark_node so that we know it is an overriding
2513 function. */
2517 {
2521 }
2522 }
2524 /* Warn about hidden virtual functions that are not overridden in t.
2525 We know that constructors and destructors don't apply. */
2527 void
2529 {
2534 /* We go through each separately named virtual function. */
2536 {
2537 tree fns;
2538 tree name;
2539 tree fndecl;
2540 tree base_fndecls;
2543 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2544 have the same name. Figure out what name that is. */
2546 /* There are no possibly hidden functions yet. */
2548 /* Iterate through all of the base classes looking for possibly
2549 hidden functions. */
2551 {
2554 base_fndecls);
2555 }
2557 /* If there are no functions to hide, continue. */
2561 /* Remove any overridden functions. */
2563 {
2566 {
2570 /* If the method from the base class has the same
2571 signature as the method from the derived class, it
2572 has been overridden. */
2575 else
2577 }
2578 }
2580 /* Now give a warning for all base functions without overriders,
2581 as they are hidden. */
2583 {
2584 /* Here we know it is a hider, and no overrider exists. */
2589 }
2590 }
2591 }
2593 /* Check for things that are invalid. There are probably plenty of other
2594 things we should check for also. */
2596 static void
2598 {
2599 tree field;
2602 {
2610 {
2613 {
2614 /* We're generally only interested in entities the user
2615 declared, but we also find nested classes by noticing
2616 the TYPE_DECL that we create implicitly. You're
2617 allowed to put one anonymous union inside another,
2618 though, so we explicitly tolerate that. We use
2619 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2620 we also allow unnamed types used for defining fields. */
2628 elt);
2631 {
2633 elt);
2635 }
2639 elt);
2642 elt);
2646 }
2647 }
2648 }
2649 }
2651 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2652 will be used later during class template instantiation.
2653 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2654 a non-static member data (FIELD_DECL), a member function
2655 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2656 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2657 When FRIEND_P is nonzero, T is either a friend class
2658 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2659 (FUNCTION_DECL, TEMPLATE_DECL). */
2661 void
2663 {
2664 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2669 }
2671 /* Create default constructors, assignment operators, and so forth for
2672 the type indicated by T, if they are needed.
2673 CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2674 CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2675 class cannot have a default constructor, copy constructor taking a
2676 const reference argument, or an assignment operator taking a const
2677 reference, respectively. If a virtual destructor is created, its
2678 DECL is returned; otherwise the return value is NULL_TREE. */
2680 static void
2685 {
2686 tree default_fn;
2693 /* Destructor. */
2695 {
2699 /* If we couldn't make it work, then pretend we didn't need it. */
2702 else
2703 {
2709 }
2710 }
2711 else
2712 /* Any non-implicit destructor is non-trivial. */
2715 /* Default constructor. */
2717 {
2721 }
2723 /* Copy constructor. */
2725 {
2726 /* ARM 12.18: You get either X(X&) or X(const X&), but
2727 not both. --Chip */
2728 default_fn
2733 }
2735 /* Assignment operator. */
2737 {
2738 default_fn
2743 }
2745 /* Now, hook all of the new functions on to TYPE_METHODS,
2746 and add them to the CLASSTYPE_METHOD_VEC. */
2748 {
2751 }
2753 /* G++ 3.2 put the implicit destructor at the *beginning* of the
2754 list, which cause the destructor to be emitted in an incorrect
2755 location in the vtable. */
2757 else
2758 {
2761 "and may change in a future version of GCC due to implicit "
2763 t);
2766 }
2769 }
2771 /* Subroutine of finish_struct_1. Recursively count the number of fields
2772 in TYPE, including anonymous union members. */
2774 static int
2776 {
2777 tree x;
2780 {
2783 else
2785 }
2787 }
2789 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2790 TREE_LIST FIELDS to the TREE_VEC FIELD_VEC, starting at offset IDX. */
2792 static int
2794 {
2795 tree x;
2797 {
2800 else
2802 }
2804 }
2806 /* FIELD is a bit-field. We are finishing the processing for its
2807 enclosing type. Issue any appropriate messages and set appropriate
2808 flags. */
2810 static void
2812 {
2816 /* Detect invalid bit-field type. */
2819 {
2822 }
2824 /* Detect and ignore out of range field width. */
2826 {
2829 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2832 /* detect invalid field size. */
2835 else
2839 {
2841 field);
2843 }
2845 {
2848 }
2850 {
2853 }
2863 min_precision
2868 }
2870 /* Remove the bit-field width indicator so that the rest of the
2871 compiler does not treat that value as an initializer. */
2875 {
2878 }
2879 else
2880 {
2881 /* Non-bit-fields are aligned for their type. */
2884 }
2885 }
2887 /* FIELD is a non bit-field. We are finishing the processing for its
2888 enclosing type T. Issue any appropriate messages and set appropriate
2889 flags. */
2891 static void
2893 tree t,
2898 {
2901 /* An anonymous union cannot contain any fields which would change
2902 the settings of CANT_HAVE_CONST_CTOR and friends. */
2904 ;
2905 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2906 structs. So, we recurse through their fields here. */
2908 {
2909 tree fields;
2915 any_default_members);
2916 }
2917 /* Check members with class type for constructors, destructors,
2918 etc. */
2920 {
2921 /* Never let anything with uninheritable virtuals
2922 make it through without complaint. */
2926 {
2929 field);
2932 field);
2935 field);
2936 }
2937 else
2938 {
2944 }
2955 }
2957 {
2958 /* `build_class_init_list' does not recognize
2959 non-FIELD_DECLs. */
2963 }
2964 }
2966 /* Check the data members (both static and non-static), class-scoped
2967 typedefs, etc., appearing in the declaration of T. Issue
2968 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2969 declaration order) of access declarations; each TREE_VALUE in this
2970 list is a USING_DECL.
2972 In addition, set the following flags:
2974 EMPTY_P
2975 The class is empty, i.e., contains no non-static data members.
2977 CANT_HAVE_DEFAULT_CTOR_P
2978 This class cannot have an implicitly generated default
2979 constructor.
2981 CANT_HAVE_CONST_CTOR_P
2982 This class cannot have an implicitly generated copy constructor
2983 taking a const reference.
2985 CANT_HAVE_CONST_ASN_REF
2986 This class cannot have an implicitly generated assignment
2987 operator taking a const reference.
2989 All of these flags should be initialized before calling this
2990 function.
2992 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2993 fields can be added by adding to this chain. */
2995 static void
3000 {
3006 /* First, delete any duplicate fields. */
3009 /* Assume there are no access declarations. */
3011 /* Assume this class has no pointer members. */
3013 /* Assume none of the members of this class have default
3014 initializations. */
3018 {
3025 {
3029 /* We don't treat zero-width bitfields as making a class
3030 non-empty. */
3031 ;
3032 else
3033 {
3034 tree element_type;
3036 /* The class is non-empty. */
3038 /* The class is not even nearly empty. */
3040 /* If one of the data members contains an empty class,
3041 so does T. */
3046 }
3047 }
3050 {
3051 /* Prune the access declaration from the list of fields. */
3054 /* Save the access declarations for our caller. */
3057 /* Since we've reset *FIELD there's no reason to skip to the
3058 next field. */
3061 }
3067 /* If we've gotten this far, it's a data member, possibly static,
3068 or an enumerator. */
3072 /* ``A local class cannot have static data members.'' ARM 9.4 */
3076 /* Perform error checking that did not get done in
3077 grokdeclarator. */
3079 {
3081 x);
3084 }
3086 {
3090 }
3092 {
3096 }
3101 /* When this goes into scope, it will be a non-local reference. */
3108 {
3110 /* Unions cannot have static members. */
3114 }
3116 /* Now it can only be a FIELD_DECL. */
3121 /* If this is of reference type, check if it needs an init.
3122 Also do a little ANSI jig if necessary. */
3124 {
3129 /* ARM $12.6.2: [A member initializer list] (or, for an
3130 aggregate, initialization by a brace-enclosed list) is the
3131 only way to initialize nonstatic const and reference
3132 members. */
3139 }
3150 /* DR 148 now allows pointers to members (which are POD themselves),
3151 to be allowed in POD structs. */
3157 /* If any field is const, the structure type is pseudo-const. */
3159 {
3164 /* ARM $12.6.2: [A member initializer list] (or, for an
3165 aggregate, initialization by a brace-enclosed list) is the
3166 only way to initialize nonstatic const and reference
3167 members. */
3174 }
3175 /* A field that is pseudo-const makes the structure likewise. */
3177 {
3182 }
3184 /* Core issue 80: A nonstatic data member is required to have a
3185 different name from the class iff the class has a
3186 user-defined constructor. */
3190 /* We set DECL_C_BIT_FIELD in grokbitfield.
3191 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3194 else
3196 cant_have_const_ctor_p,
3197 cant_have_default_ctor_p,
3198 no_const_asn_ref_p,
3200 }
3202 /* Effective C++ rule 11. */
3205 {
3209 {
3213 }
3216 }
3219 /* Check anonymous struct/anonymous union fields. */
3222 /* We've built up the list of access declarations in reverse order.
3223 Fix that now. */
3225 }
3227 /* If TYPE is an empty class type, records its OFFSET in the table of
3228 OFFSETS. */
3230 static int
3232 {
3233 splay_tree_node n;
3238 /* Record the location of this empty object in OFFSETS. */
3246 type,
3250 }
3252 /* Returns nonzero if TYPE is an empty class type and there is
3253 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3255 static int
3257 {
3258 splay_tree_node n;
3259 tree t;
3264 /* Record the location of this empty object in OFFSETS. */
3274 }
3276 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3277 F for every subobject, passing it the type, offset, and table of
3278 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3279 be traversed.
3281 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3282 than MAX_OFFSET will not be walked.
3284 If F returns a nonzero value, the traversal ceases, and that value
3285 is returned. Otherwise, returns zero. */
3287 static int
3289 subobject_offset_fn f,
3290 tree offset,
3291 splay_tree offsets,
3292 tree max_offset,
3294 {
3298 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3299 stop. */
3304 {
3308 }
3311 {
3312 tree field;
3313 tree binfo;
3316 /* Avoid recursing into objects that are not interesting. */
3320 /* Record the location of TYPE. */
3325 /* Iterate through the direct base classes of TYPE. */
3329 {
3330 tree binfo_offset;
3345 offset,
3347 else
3348 {
3349 tree orig_binfo;
3350 /* We cannot rely on BINFO_OFFSET being set for the base
3351 class yet, but the offsets for direct non-virtual
3352 bases can be calculated by going back to the TYPE. */
3355 offset,
3357 }
3360 f,
3361 binfo_offset,
3362 offsets,
3363 max_offset,
3368 }
3371 {
3372 tree vbase;
3374 /* Iterate through the virtual base classes of TYPE. In G++
3375 3.2, we included virtual bases in the direct base class
3376 loop above, which results in incorrect results; the
3377 correct offsets for virtual bases are only known when
3378 working with the most derived type. */
3381 vbase;
3383 {
3386 f,
3388 offset,
3390 offsets,
3391 max_offset,
3395 }
3396 else
3397 {
3398 /* We still have to walk the primary base, if it is
3399 virtual. (If it is non-virtual, then it was walked
3400 above.) */
3404 {
3405 r = (walk_subobject_offsets
3410 }
3411 }
3412 }
3414 /* Iterate through the fields of TYPE. */
3417 {
3418 tree field_offset;
3422 else
3423 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3427 f,
3429 offset,
3430 field_offset),
3431 offsets,
3432 max_offset,
3436 }
3437 }
3439 {
3442 tree index;
3444 /* Avoid recursing into objects that are not interesting. */
3449 /* Step through each of the elements in the array. */
3451 /* G++ 3.2 had an off-by-one error here. */
3456 {
3458 f,
3459 offset,
3460 offsets,
3461 max_offset,
3467 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3468 there's no point in iterating through the remaining
3469 elements of the array. */
3472 }
3473 }
3476 }
3478 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3479 OFFSETS. If VBASES_P is nonzero, virtual bases of TYPE are
3480 examined. */
3482 static void
3484 tree offset,
3485 splay_tree offsets,
3487 {
3490 }
3492 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3493 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3494 virtual bases of TYPE are examined. */
3496 static int
3498 tree offset,
3499 splay_tree offsets,
3501 {
3502 splay_tree_node max_node;
3504 /* Get the node in OFFSETS that indicates the maximum offset where
3505 an empty subobject is located. */
3507 /* If there aren't any empty subobjects, then there's no point in
3508 performing this check. */
3514 vbases_p);
3515 }
3517 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3518 non-static data member of the type indicated by RLI. BINFO is the
3519 binfo corresponding to the base subobject, OFFSETS maps offsets to
3520 types already located at those offsets. This function determines
3521 the position of the DECL. */
3523 static void
3525 tree decl,
3526 tree binfo,
3527 splay_tree offsets)
3528 {
3531 tree type;
3534 {
3535 /* For the purposes of determining layout conflicts, we want to
3536 use the class type of BINFO; TREE_TYPE (DECL) will be the
3537 CLASSTYPE_AS_BASE version, which does not contain entries for
3538 zero-sized bases. */
3541 }
3542 else
3543 {
3546 }
3548 /* Try to place the field. It may take more than one try if we have
3549 a hard time placing the field without putting two objects of the
3550 same type at the same address. */
3552 {
3555 /* Place this field. */
3559 /* We have to check to see whether or not there is already
3560 something of the same type at the offset we're about to use.
3561 For example:
3563 struct S {};
3564 struct T : public S { int i; };
3565 struct U : public S, public T {};
3567 Here, we put S at offset zero in U. Then, we can't put T at
3568 offset zero -- its S component would be at the same address
3569 as the S we already allocated. So, we have to skip ahead.
3570 Since all data members, including those whose type is an
3571 empty class, have nonzero size, any overlap can happen only
3572 with a direct or indirect base-class -- it can't happen with
3573 a data member. */
3574 /* G++ 3.2 did not check for overlaps when placing a non-empty
3575 virtual base. */
3580 {
3581 /* Strip off the size allocated to this field. That puts us
3582 at the first place we could have put the field with
3583 proper alignment. */
3586 /* Bump up by the alignment required for the type. */
3587 rli->bitpos
3593 }
3594 else
3595 /* There was no conflict. We're done laying out this field. */
3597 }
3599 /* Now that we know where it will be placed, update its
3600 BINFO_OFFSET. */
3602 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3603 this point because their BINFO_OFFSET is copied from another
3604 hierarchy. Therefore, we may not need to add the entire
3605 OFFSET. */
3610 }
3612 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3614 static int
3616 tree offset,
3617 splay_tree offsets ATTRIBUTE_UNUSED)
3618 {
3620 }
3622 /* Layout the empty base BINFO. EOC indicates the byte currently just
3623 past the end of the class, and should be correctly aligned for a
3624 class of the type indicated by BINFO; OFFSETS gives the offsets of
3625 the empty bases allocated so far. T is the most derived
3626 type. Return nonzero iff we added it at the end. */
3628 static bool
3630 {
3631 tree alignment;
3635 /* This routine should only be used for empty classes. */
3646 /* This is an empty base class. We first try to put it at offset
3647 zero. */
3650 offsets,
3652 {
3653 /* That didn't work. Now, we move forward from the next
3654 available spot in the class. */
3658 {
3661 offsets,
3663 /* We finally found a spot where there's no overlap. */
3666 /* There's overlap here, too. Bump along to the next spot. */
3668 }
3669 }
3671 }
3673 /* Layout the the base given by BINFO in the class indicated by RLI.
3674 *BASE_ALIGN is a running maximum of the alignments of
3675 any base class. OFFSETS gives the location of empty base
3676 subobjects. T is the most derived type. Return nonzero if the new
3677 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3678 *NEXT_FIELD, unless BINFO is for an empty base class.
3680 Returns the location at which the next field should be inserted. */
3685 {
3690 /* This error is now reported in xref_tag, thus giving better
3691 location information. */
3694 /* Place the base class. */
3696 {
3697 tree decl;
3699 /* The containing class is non-empty because it has a non-empty
3700 base class. */
3703 /* Create the FIELD_DECL. */
3713 /* Try to place the field. It may take more than one try if we
3714 have a hard time placing the field without putting two
3715 objects of the same type at the same address. */
3717 /* Add the new FIELD_DECL to the list of fields for T. */
3721 }
3722 else
3723 {
3724 tree eoc;
3727 /* On some platforms (ARM), even empty classes will not be
3728 byte-aligned. */
3732 /* A nearly-empty class "has no proper base class that is empty,
3733 not morally virtual, and at an offset other than zero." */
3735 {
3738 /* The check above (used in G++ 3.2) is insufficient because
3739 an empty class placed at offset zero might itself have an
3740 empty base at a nonzero offset. */
3742 empty_base_at_nonzero_offset_p,
3743 size_zero_node,
3747 {
3753 }
3754 }
3756 /* We do not create a FIELD_DECL for empty base classes because
3757 it might overlap some other field. We want to be able to
3758 create CONSTRUCTORs for the class by iterating over the
3759 FIELD_DECLs, and the back end does not handle overlapping
3760 FIELD_DECLs. */
3762 /* An empty virtual base causes a class to be non-empty
3763 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3764 here because that was already done when the virtual table
3765 pointer was created. */
3766 }
3768 /* Record the offsets of BINFO and its base subobjects. */
3771 offsets,
3775 }
3777 /* Layout all of the non-virtual base classes. Record empty
3778 subobjects in OFFSETS. T is the most derived type. Return nonzero
3779 if the type cannot be nearly empty. The fields created
3780 corresponding to the base classes will be inserted at
3781 *NEXT_FIELD. */
3783 static void
3786 {
3787 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3788 subobjects. */
3793 /* The primary base class is always allocated first. */
3798 /* Now allocate the rest of the bases. */
3800 {
3801 tree base_binfo;
3805 /* The primary base was already allocated above, so we don't
3806 need to allocate it again here. */
3810 /* Virtual bases are added at the end (a primary virtual base
3811 will have already been added). */
3817 }
3818 }
3820 /* Go through the TYPE_METHODS of T issuing any appropriate
3821 diagnostics, figuring out which methods override which other
3822 methods, and so forth. */
3824 static void
3826 {
3827 tree x;
3830 {
3831 /* If this was an evil function, don't keep it in class. */
3840 /* The name of the field is the original field name
3841 Save this in auxiliary field for later overloading. */
3843 {
3848 }
3849 }
3850 }
3852 /* FN is a constructor or destructor. Clone the declaration to create
3853 a specialized in-charge or not-in-charge version, as indicated by
3854 NAME. */
3856 static tree
3858 {
3859 tree parms;
3860 tree clone;
3862 /* Copy the function. */
3864 /* Remember where this function came from. */
3867 /* Reset the function name. */
3870 /* There's no pending inline data for this function. */
3873 /* And it hasn't yet been deferred. */
3876 /* The base-class destructor is not virtual. */
3878 {
3882 }
3884 /* If there was an in-charge parameter, drop it from the function
3885 type. */
3887 {
3888 tree basetype;
3889 tree parmtypes;
3890 tree exceptions;
3895 /* Skip the `this' parameter. */
3897 /* Skip the in-charge parameter. */
3899 /* And the VTT parm, in a complete [cd]tor. */
3903 /* If this is subobject constructor or destructor, add the vtt
3904 parameter. */
3908 parmtypes);
3911 exceptions);
3912 }
3914 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3915 aren't function parameters; those are the template parameters. */
3917 {
3919 /* Remove the in-charge parameter. */
3921 {
3925 }
3926 /* And the VTT parm, in a complete [cd]tor. */
3928 {
3931 else
3932 {
3936 }
3937 }
3940 {
3943 }
3944 }
3946 /* Create the RTL for this function. */
3950 /* Make it easy to find the CLONE given the FN. */
3954 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3956 {
3957 tree result;
3964 }
3969 }
3971 /* Produce declarations for all appropriate clones of FN. If
3972 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3973 CLASTYPE_METHOD_VEC as well. */
3975 void
3977 {
3978 tree clone;
3980 /* Avoid inappropriate cloning. */
3986 {
3987 /* For each constructor, we need two variants: an in-charge version
3988 and a not-in-charge version. */
3995 }
3996 else
3997 {
4000 /* For each destructor, we need three variants: an in-charge
4001 version, a not-in-charge version, and an in-charge deleting
4002 version. We clone the deleting version first because that
4003 means it will go second on the TYPE_METHODS list -- and that
4004 corresponds to the correct layout order in the virtual
4005 function table.
4007 For a non-virtual destructor, we do not build a deleting
4008 destructor. */
4010 {
4014 }
4021 }
4023 /* Note that this is an abstract function that is never emitted. */
4025 }
4027 /* DECL is an in charge constructor, which is being defined. This will
4028 have had an in class declaration, from whence clones were
4029 declared. An out-of-class definition can specify additional default
4030 arguments. As it is the clones that are involved in overload
4031 resolution, we must propagate the information from the DECL to its
4032 clones. */
4034 void
4036 {
4037 tree clone;
4041 {
4048 /* Skip the 'this' parameter. */
4064 {
4069 {
4070 /* A default parameter has been added. Adjust the
4071 clone's parameters. */
4074 tree type;
4079 {
4082 clone_parms);
4084 }
4087 clone_parms);
4094 }
4095 }
4097 }
4098 }
4100 /* For each of the constructors and destructors in T, create an
4101 in-charge and not-in-charge variant. */
4103 static void
4105 {
4106 tree fns;
4108 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4109 out now. */
4117 }
4119 /* Remove all zero-width bit-fields from T. */
4121 static void
4123 {
4128 {
4133 else
4135 }
4136 }
4138 /* Returns TRUE iff we need a cookie when dynamically allocating an
4139 array whose elements have the indicated class TYPE. */
4141 static bool
4143 {
4144 tree fns;
4149 /* If there's a non-trivial destructor, we need a cookie. In order
4150 to iterate through the array calling the destructor for each
4151 element, we'll have to know how many elements there are. */
4155 /* If the usual deallocation function is a two-argument whose second
4156 argument is of type `size_t', then we have to pass the size of
4157 the array to the deallocation function, so we will need to store
4158 a cookie. */
4162 /* If there are no `operator []' members, or the lookup is
4163 ambiguous, then we don't need a cookie. */
4166 /* Loop through all of the functions. */
4168 {
4169 tree fn;
4170 tree second_parm;
4172 /* Select the current function. */
4174 /* See if this function is a one-argument delete function. If
4175 it is, then it will be the usual deallocation function. */
4179 /* Otherwise, if we have a two-argument function and the second
4180 argument is `size_t', it will be the usual deallocation
4181 function -- unless there is one-argument function, too. */
4185 }
4188 }
4190 /* Check the validity of the bases and members declared in T. Add any
4191 implicitly-generated functions (like copy-constructors and
4192 assignment operators). Compute various flag bits (like
4193 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4194 level: i.e., independently of the ABI in use. */
4196 static void
4198 {
4199 /* Nonzero if we are not allowed to generate a default constructor
4200 for this case. */
4202 /* Nonzero if the implicitly generated copy constructor should take
4203 a non-const reference argument. */
4205 /* Nonzero if the the implicitly generated assignment operator
4206 should take a non-const reference argument. */
4208 tree access_decls;
4210 /* By default, we use const reference arguments and generate default
4211 constructors. */
4216 /* Check all the base-classes. */
4220 /* Check all the data member declarations. */
4226 /* Check all the method declarations. */
4229 /* A nearly-empty class has to be vptr-containing; a nearly empty
4230 class contains just a vptr. */
4234 /* Do some bookkeeping that will guide the generation of implicitly
4235 declared member functions. */
4253 /* Synthesize any needed methods. Note that methods will be synthesized
4254 for anonymous unions; grok_x_components undoes that. */
4256 cant_have_const_ctor,
4257 no_const_asn_ref);
4259 /* Create the in-charge and not-in-charge variants of constructors
4260 and destructors. */
4263 /* Process the using-declarations. */
4267 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4270 /* Figure out whether or not we will need a cookie when dynamically
4271 allocating an array of this type. */
4274 }
4276 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4277 accordingly. If a new vfield was created (because T doesn't have a
4278 primary base class), then the newly created field is returned. It
4279 is not added to the TYPE_FIELDS list; it is the caller's
4280 responsibility to do that. Accumulate declared virtual functions
4281 on VIRTUALS_P. */
4283 static tree
4285 {
4286 tree fn;
4288 /* Collect the virtual functions declared in T. */
4292 {
4300 }
4302 /* If we couldn't find an appropriate base class, create a new field
4303 here. Even if there weren't any new virtual functions, we might need a
4304 new virtual function table if we're supposed to include vptrs in
4305 all classes that need them. */
4307 {
4308 /* We build this decl with vtbl_ptr_type_node, which is a
4309 `vtable_entry_type*'. It might seem more precise to use
4310 `vtable_entry_type (*)[N]' where N is the number of firtual
4311 functions. However, that would require the vtable pointer in
4312 base classes to have a different type than the vtable pointer
4313 in derived classes. We could make that happen, but that
4314 still wouldn't solve all the problems. In particular, the
4315 type-based alias analysis code would decide that assignments
4316 to the base class vtable pointer can't alias assignments to
4317 the derived class vtable pointer, since they have different
4318 types. Thus, in a derived class destructor, where the base
4319 class constructor was inlined, we could generate bad code for
4320 setting up the vtable pointer.
4322 Therefore, we use one type for all vtable pointers. We still
4323 use a type-correct type; it's just doesn't indicate the array
4324 bounds. That's better than using `void*' or some such; it's
4325 cleaner, and it let's the alias analysis code know that these
4326 stores cannot alias stores to void*! */
4327 tree field;
4338 /* This class is non-empty. */
4342 /* If there were any baseclasses, they can't possibly be at
4343 offset zero any more, because that's where the vtable
4344 pointer is. So, converting to a base class is going to
4345 take work. */
4349 }
4352 }
4354 /* Fixup the inline function given by INFO now that the class is
4355 complete. */
4357 static void
4359 {
4361 {
4364 {
4367 }
4368 }
4369 }
4371 /* Fixup the inline methods and friends in TYPE now that TYPE is
4372 complete. */
4374 static void
4376 {
4380 {
4385 else
4387 }
4389 /* Do inline member functions. */
4393 /* Do friends. */
4395 method;
4399 }
4401 /* Add OFFSET to all base types of BINFO which is a base in the
4402 hierarchy dominated by T.
4404 OFFSET, which is a type offset, is number of bytes. */
4406 static void
4408 {
4410 tree primary_binfo;
4412 /* Update BINFO's offset. */
4417 offset));
4419 /* Find the primary base class. */
4422 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4423 downwards. */
4425 {
4426 tree base_binfo;
4428 /* On the first time through the loop, do the primary base.
4429 Because the primary base need not be an immediate base, we
4430 must handle the primary base specially. */
4432 {
4437 }
4438 else
4439 {
4441 /* Don't do the primary base twice. */
4444 }
4446 /* Skip virtual bases that aren't our canonical primary base. */
4452 }
4453 }
4455 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4456 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4457 empty subobjects of T. */
4459 static void
4461 {
4462 tree vbase;
4471 {
4472 /* In G++ 3.2, we incorrectly rounded the size before laying out
4473 the virtual bases. */
4475 #ifdef STRUCTURE_SIZE_BOUNDARY
4476 /* Packed structures don't need to have minimum size. */
4479 #endif
4483 }
4485 /* Find the last field. The artificial fields created for virtual
4486 bases will go after the last extant field to date. */
4491 /* Go through the virtual bases, allocating space for each virtual
4492 base that is not already a primary base class. These are
4493 allocated in inheritance graph order. */
4495 {
4500 {
4503 /* This virtual base is not a primary base of any class in the
4504 hierarchy, so we have to add space for it. */
4508 /* If the first virtual base might have been placed at a
4509 lower address, had we started from CLASSTYPE_SIZE, rather
4510 than TYPE_SIZE, issue a warning. There can be both false
4511 positives and false negatives from this warning in rare
4512 cases; to deal with all the possibilities would probably
4513 require performing both layout algorithms and comparing
4514 the results which is not particularly tractable. */
4516 && first_vbase
4517 && (tree_int_cst_lt
4521 bitsize_unit_node),
4523 warning ("offset of virtual base `%T' is not ABI-compliant and may change in a future version of GCC",
4524 basetype);
4527 }
4528 }
4529 }
4531 /* Returns the offset of the byte just past the end of the base class
4532 BINFO. */
4534 static tree
4536 {
4537 tree size;
4540 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4541 allocate some space for it. It cannot have virtual bases, so
4542 TYPE_SIZE_UNIT is fine. */
4544 else
4548 }
4550 /* Returns the offset of the byte just past the end of the base class
4551 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4552 only non-virtual bases are included. */
4554 static tree
4556 {
4558 tree binfo;
4559 tree offset;
4563 {
4574 }
4576 /* G++ 3.2 did not check indirect virtual bases. */
4579 binfo;
4581 {
4585 }
4588 }
4590 /* Warn about bases of T that are inaccessible because they are
4591 ambiguous. For example:
4593 struct S {};
4594 struct T : public S {};
4595 struct U : public S, public T {};
4597 Here, `(S*) new U' is not allowed because there are two `S'
4598 subobjects of U. */
4600 static void
4602 {
4604 tree vbases;
4605 tree basetype;
4607 /* Check direct bases. */
4609 {
4615 }
4617 /* Check for ambiguous virtual bases. */
4620 vbases;
4622 {
4628 }
4629 }
4631 /* Compare two INTEGER_CSTs K1 and K2. */
4633 static int
4635 {
4637 }
4639 /* Increase the size indicated in RLI to account for empty classes
4640 that are "off the end" of the class. */
4642 static void
4644 {
4645 tree eoc;
4646 tree rli_size;
4648 /* It might be the case that we grew the class to allocate a
4649 zero-sized base class. That won't be reflected in RLI, yet,
4650 because we are willing to overlay multiple bases at the same
4651 offset. However, now we need to make sure that RLI is big enough
4652 to reflect the entire class. */
4658 {
4660 rli->bitpos
4669 }
4670 }
4672 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4673 BINFO_OFFSETs for all of the base-classes. Position the vtable
4674 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4676 static void
4678 {
4679 tree non_static_data_members;
4680 tree field;
4681 tree vptr;
4682 record_layout_info rli;
4683 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4684 types that appear at that offset. */
4685 splay_tree empty_base_offsets;
4686 /* True if the last field layed out was a bit-field. */
4688 /* The location at which the next field should be inserted. */
4690 /* T, as a base class. */
4691 tree base_t;
4693 /* Keep track of the first non-static data member. */
4696 /* Start laying out the record. */
4699 /* If possible, we reuse the virtual function table pointer from one
4700 of our base classes. */
4703 /* Create a pointer to our virtual function table. */
4706 /* The vptr is always the first thing in the class. */
4708 {
4713 }
4714 else
4717 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4722 /* Layout the non-static data members. */
4724 {
4725 tree type;
4726 tree padding;
4729 /* We still pass things that aren't non-static data members to
4730 the back-end, in case it wants to do something with them. */
4732 {
4734 /* If the static data member has incomplete type, keep track
4735 of it so that it can be completed later. (The handling
4736 of pending statics in finish_record_layout is
4737 insufficient; consider:
4739 struct S1;
4740 struct S2 { static S1 s1; };
4742 At this point, finish_record_layout will be called, but
4743 S1 is still incomplete.) */
4747 }
4753 /* If this field is a bit-field whose width is greater than its
4754 type, then there are some special rules for allocating
4755 it. */
4758 {
4759 integer_type_kind itk;
4760 tree integer_type;
4761 /* We must allocate the bits as if suitably aligned for the
4762 longest integer type that fits in this many bits. type
4763 of the field. Then, we are supposed to use the left over
4764 bits as additional padding. */
4770 /* ITK now indicates a type that is too large for the
4771 field. We have to back up by one to find the largest
4772 type that fits. */
4775 /* Figure out how much additional padding is required. GCC
4776 3.2 always created a padding field, even if it had zero
4777 width. */
4780 {
4782 /* In a union, the padding field must have the full width
4783 of the bit-field; all fields start at offset zero. */
4785 else
4786 {
4789 "ABI-compliant and may change in a future "
4791 t);
4794 }
4795 }
4796 #ifdef PCC_BITFIELD_TYPE_MATTERS
4797 /* An unnamed bitfield does not normally affect the
4798 alignment of the containing class on a target where
4799 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4800 make any exceptions for unnamed bitfields when the
4801 bitfields are longer than their types. Therefore, we
4802 temporarily give the field a name. */
4804 {
4807 }
4808 #endif
4812 }
4815 empty_base_offsets);
4816 /* If the bit-field had no name originally, remove the name
4817 now. */
4821 /* Remember the location of any empty classes in FIELD. */
4825 empty_base_offsets,
4828 /* If a bit-field does not immediately follow another bit-field,
4829 and yet it starts in the middle of a byte, we have failed to
4830 comply with the ABI. */
4833 && !last_field_was_bitfield
4836 bitsize_unit_node)))
4837 cp_warning_at ("offset of `%D' is not ABI-compliant and may change in a future version of GCC",
4838 field);
4840 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4841 offset of the field. */
4847 "classes to be placed at different locations in a "
4849 field);
4851 /* If we needed additional padding after this field, add it
4852 now. */
4854 {
4855 tree padding_field;
4858 NULL_TREE,
4859 char_type_node);
4864 NULL_TREE,
4865 empty_base_offsets);
4866 }
4869 }
4872 {
4873 /* Make sure that we are on a byte boundary so that the size of
4874 the class without virtual bases will always be a round number
4875 of bytes. */
4878 }
4880 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4881 padding. */
4885 /* Delete all zero-width bit-fields from the list of fields. Now
4886 that the type is laid out they are no longer important. */
4889 /* Create the version of T used for virtual bases. We do not use
4890 make_aggr_type for this version; this is an artificial type. For
4891 a POD type, we just reuse T. */
4893 {
4896 /* Set the size and alignment for the new type. In G++ 3.2, all
4897 empty classes were considered to have size zero when used as
4898 base classes. */
4900 {
4906 t);
4907 }
4908 else
4909 {
4910 tree eoc;
4912 /* If the ABI version is not at least two, and the last
4913 field was a bit-field, RLI may not be on a byte
4914 boundary. In particular, rli_size_unit_so_far might
4915 indicate the last complete byte, while rli_size_so_far
4916 indicates the total number of bits used. Therefore,
4917 rli_size_so_far, rather than rli_size_unit_so_far, is
4918 used to compute TYPE_SIZE_UNIT. */
4926 eoc);
4933 }
4937 /* Copy the fields from T. */
4941 {
4950 }
4952 /* Record the base version of the type. */
4955 }
4956 else
4959 /* Every empty class contains an empty class. */
4963 /* Set the TYPE_DECL for this type to contain the right
4964 value for DECL_OFFSET, so that we can use it as part
4965 of a COMPONENT_REF for multiple inheritance. */
4968 /* Now fix up any virtual base class types that we left lying
4969 around. We must get these done before we try to lay out the
4970 virtual function table. As a side-effect, this will remove the
4971 base subobject fields. */
4974 /* Make sure that empty classes are reflected in RLI at this
4975 point. */
4978 /* Make sure not to create any structures with zero size. */
4983 /* Let the back-end lay out the type. */
4986 /* Warn about bases that can't be talked about due to ambiguity. */
4989 /* Clean up. */
4991 }
4993 /* Returns the virtual function with which the vtable for TYPE is
4994 emitted, or NULL_TREE if that heuristic is not applicable to TYPE. */
4996 static tree
4998 {
4999 tree method;
5002 || processing_template_decl
5015 }
5017 /* Perform processing required when the definition of T (a class type)
5018 is complete. */
5020 void
5022 {
5023 tree x;
5024 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5027 tree vfield;
5030 {
5033 else
5037 }
5039 /* If this type was previously laid out as a forward reference,
5040 make sure we lay it out again. */
5047 /* Make assumptions about the class; we'll reset the flags if
5048 necessary. */
5053 /* Do end-of-class semantic processing: checking the validity of the
5054 bases and members and add implicitly generated methods. */
5057 /* Find the key method */
5059 {
5062 /* If a polymorphic class has no key method, we may emit the vtable
5063 in every translation unit where the class definition appears. */
5066 }
5068 /* Layout the class itself. */
5071 /* Make sure that we get our own copy of the vfield FIELD_DECL. */
5074 {
5080 /* The vtable better be at the start. */
5089 }
5090 else
5095 /* If we created a new vtbl pointer for this class, add it to the
5096 list. */
5101 /* If necessary, create the primary vtable for this class. */
5103 {
5104 /* We must enter these virtuals into the table. */
5108 /* Here we know enough to change the type of our virtual
5109 function table, but we will wait until later this function. */
5111 }
5114 {
5116 tree fn;
5125 /* Add entries for virtual functions introduced by this class. */
5128 /* Set DECL_VINDEX for all functions declared in this class. */
5130 fn;
5132 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5134 {
5138 /* A thunk. We should never be calling this entry directly
5139 from this vtable -- we'd use the entry for the non
5140 thunk base function. */
5144 }
5145 }
5149 /* Complete the rtl for any static member objects of the type we're
5150 working on. */
5156 /* Done with FIELDS...now decide whether to sort these for
5157 faster lookups later.
5159 We use a small number because most searches fail (succeeding
5160 ultimately as the search bores through the inheritance
5161 hierarchy), and we want this failure to occur quickly. */
5165 {
5169 field_decl_cmp);
5173 }
5176 {
5181 /* Mark the fact that constructor for T could affect anybody
5182 inheriting from T who wants to initialize vtables for
5183 VFIELDS's type. */
5186 }
5188 /* Make the rtl for any new vtables we have created, and unmark
5189 the base types we marked. */
5192 /* Build the VTT for T. */
5208 /* Finish debugging output for this type. */
5210 }
5212 /* When T was built up, the member declarations were added in reverse
5213 order. Rearrange them to declaration order. */
5215 void
5217 {
5218 tree next;
5219 tree prev;
5220 tree x;
5222 /* The following lists are all in reverse order. Put them in
5223 declaration order now. */
5228 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5229 reverse order, so we can't just use nreverse. */
5234 {
5238 }
5240 {
5244 }
5245 }
5247 tree
5249 {
5253 /* Now that we've got all the field declarations, reverse everything
5254 as necessary. */
5259 /* Nadger the current location so that diagnostics point to the start of
5260 the struct, not the end. */
5265 {
5268 }
5269 else
5279 else
5286 }
5287 \f
5288 /* Return the dynamic type of INSTANCE, if known.
5289 Used to determine whether the virtual function table is needed
5290 or not.
5292 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5293 of our knowledge of its type. *NONNULL should be initialized
5294 before this function is called. */
5296 static tree
5298 {
5300 {
5304 else
5309 /* This is a call to a constructor, hence it's never zero. */
5311 {
5315 }
5319 /* This is a call to a constructor, hence it's never zero. */
5321 {
5325 }
5336 /* Propagate nonnull. */
5356 {
5360 }
5361 /* fall through... */
5366 {
5370 }
5372 {
5376 /* if we're in a ctor or dtor, we know our type. */
5380 {
5384 }
5385 }
5387 {
5388 /* Reference variables should be references to objects. */
5392 /* DECL_VAR_MARKED_P is used to prevent recursion; a
5393 variable's initializer may refer to the variable
5394 itself. */
5398 {
5399 tree type;
5405 }
5406 }
5411 }
5412 }
5414 /* Return nonzero if the dynamic type of INSTANCE is known, and
5415 equivalent to the static type. We also handle the case where
5416 INSTANCE is really a pointer. Return negative if this is a
5417 ctor/dtor. There the dynamic type is known, but this might not be
5418 the most derived base of the original object, and hence virtual
5419 bases may not be layed out according to this type.
5421 Used to determine whether the virtual function table is needed
5422 or not.
5424 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5425 of our knowledge of its type. *NONNULL should be initialized
5426 before this function is called. */
5428 int
5430 {
5442 }
5444 \f
5445 void
5447 {
5450 current_class_stack
5458 }
5460 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5461 appropriate for TYPE.
5463 If MODIFY is 1, we set IDENTIFIER_CLASS_VALUE's of names
5464 which can be seen locally to the class. They are shadowed by
5465 any subsequent local declaration (including parameter names).
5467 If MODIFY is 2, we set IDENTIFIER_CLASS_VALUE's of names
5468 which have static meaning (i.e., static members, static
5469 member functions, enum declarations, etc).
5471 If MODIFY is 3, we set IDENTIFIER_CLASS_VALUE of names
5472 which can be seen locally to the class (as in 1), but
5473 know that we are doing this for declaration purposes
5474 (i.e. friend foo::bar (int)).
5476 So that we may avoid calls to lookup_name, we cache the _TYPE
5477 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5479 For multiple inheritance, we perform a two-pass depth-first search
5480 of the type lattice. The first pass performs a pre-order search,
5481 marking types after the type has had its fields installed in
5482 the appropriate IDENTIFIER_CLASS_VALUE slot. The second pass merely
5483 unmarks the marked types. If a field or member function name
5484 appears in an ambiguous way, the IDENTIFIER_CLASS_VALUE of
5485 that name becomes `error_mark_node'. */
5487 void
5489 {
5492 /* Make sure there is enough room for the new entry on the stack. */
5494 {
5496 current_class_stack
5498 current_class_stack_size
5500 }
5502 /* Insert a new entry on the class stack. */
5507 current_class_depth++;
5509 /* Now set up the new type. */
5515 /* By default, things in classes are private, while things in
5516 structures or unions are public. */
5518 ? access_private_node
5525 {
5526 /* Forcibly remove any old class remnants. */
5528 }
5530 /* If we're about to enter a nested class, clear
5531 IDENTIFIER_CLASS_VALUE for the enclosing classes. */
5538 {
5541 else
5542 {
5543 tree item;
5545 /* We are re-entering the same class we just left, so we
5546 don't have to search the whole inheritance matrix to find
5547 all the decls to bind again. Instead, we install the
5548 cached class_shadowed list, and walk through it binding
5549 names and setting up IDENTIFIER_TYPE_VALUEs. */
5552 {
5559 }
5561 }
5564 }
5565 }
5567 /* When we exit a toplevel class scope, we save the
5568 IDENTIFIER_CLASS_VALUEs so that we can restore them quickly if we
5569 reenter the class. Here, we've entered some other class, so we
5570 must invalidate our cache. */
5572 void
5574 {
5575 tree t;
5577 /* The IDENTIFIER_CLASS_VALUEs are no longer valid. */
5583 }
5585 /* Get out of the current class scope. If we were in a class scope
5586 previously, that is the one popped to. */
5588 void
5590 {
5594 current_class_depth--;
5600 }
5602 /* Returns 1 if current_class_type is either T or a nested type of T.
5603 We start looking from 1 because entry 0 is from global scope, and has
5604 no type. */
5606 int
5608 {
5617 }
5619 /* If either current_class_type or one of its enclosing classes are derived
5620 from T, return the appropriate type. Used to determine how we found
5621 something via unqualified lookup. */
5623 tree
5625 {
5628 /* The bases of a dependent type are unknown. */
5640 }
5642 /* When entering a class scope, all enclosing class scopes' names with
5643 static meaning (static variables, static functions, types and
5644 enumerators) have to be visible. This recursive function calls
5645 pushclass for all enclosing class contexts until global or a local
5646 scope is reached. TYPE is the enclosed class. */
5648 void
5650 {
5651 tree context;
5653 /* A namespace might be passed in error cases, like A::B:C. */
5667 }
5669 /* Undoes a push_nested_class call. */
5671 void
5673 {
5679 }
5681 /* Returns the number of extern "LANG" blocks we are nested within. */
5683 int
5685 {
5687 }
5689 /* Set global variables CURRENT_LANG_NAME to appropriate value
5690 so that behavior of name-mangling machinery is correct. */
5692 void
5694 {
5698 {
5700 }
5702 {
5704 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5705 (See record_builtin_java_type in decl.c.) However, that causes
5706 incorrect debug entries if these types are actually used.
5707 So we re-enable debug output after extern "Java". */
5716 }
5718 {
5720 }
5721 else
5723 }
5725 /* Get out of the current language scope. */
5727 void
5729 {
5732 }
5733 \f
5734 /* Type instantiation routines. */
5736 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5737 matches the TARGET_TYPE. If there is no satisfactory match, return
5738 error_mark_node, and issue an error message if COMPLAIN is
5739 nonzero. Permit pointers to member function if PTRMEM is nonzero.
5740 If TEMPLATE_ONLY, the name of the overloaded function
5741 was a template-id, and EXPLICIT_TARGS are the explicitly provided
5742 template arguments. */
5744 static tree
5746 tree overload,
5750 tree explicit_targs)
5751 {
5752 /* Here's what the standard says:
5754 [over.over]
5756 If the name is a function template, template argument deduction
5757 is done, and if the argument deduction succeeds, the deduced
5758 arguments are used to generate a single template function, which
5759 is added to the set of overloaded functions considered.
5761 Non-member functions and static member functions match targets of
5762 type "pointer-to-function" or "reference-to-function." Nonstatic
5763 member functions match targets of type "pointer-to-member
5764 function;" the function type of the pointer to member is used to
5765 select the member function from the set of overloaded member
5766 functions. If a nonstatic member function is selected, the
5767 reference to the overloaded function name is required to have the
5768 form of a pointer to member as described in 5.3.1.
5770 If more than one function is selected, any template functions in
5771 the set are eliminated if the set also contains a non-template
5772 function, and any given template function is eliminated if the
5773 set contains a second template function that is more specialized
5774 than the first according to the partial ordering rules 14.5.5.2.
5775 After such eliminations, if any, there shall remain exactly one
5776 selected function. */
5780 /* We store the matches in a TREE_LIST rooted here. The functions
5781 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5782 interoperability with most_specialized_instantiation. */
5784 tree fn;
5786 /* By the time we get here, we should be seeing only real
5787 pointer-to-member types, not the internal POINTER_TYPE to
5788 METHOD_TYPE representation. */
5796 /* Check that the TARGET_TYPE is reasonable. */
5800 /* This is OK, too. */
5803 {
5804 /* This is OK, too. This comes from a conversion to reference
5805 type. */
5808 }
5809 else
5810 {
5816 }
5818 /* If we can find a non-template function that matches, we can just
5819 use it. There's no point in generating template instantiations
5820 if we're just going to throw them out anyhow. But, of course, we
5821 can only do this when we don't *need* a template function. */
5823 {
5824 tree fns;
5827 {
5829 tree fntype;
5832 /* We're not looking for templates just yet. */
5837 /* We're looking for a non-static member, and this isn't
5838 one, or vice versa. */
5841 /* See if there's a match. */
5850 }
5851 }
5853 /* Now, if we've already got a match (or matches), there's no need
5854 to proceed to the template functions. But, if we don't have a
5855 match we need to look at them, too. */
5857 {
5858 tree target_fn_type;
5859 tree target_arg_types;
5860 tree target_ret_type;
5861 tree fns;
5864 target_fn_type
5866 else
5871 /* Never do unification on the 'this' parameter. */
5876 {
5878 tree instantiation;
5879 tree instantiation_type;
5880 tree targs;
5883 /* We're only looking for templates. */
5888 /* We're not looking for a non-static member, and this is
5889 one, or vice versa. */
5892 /* Try to do argument deduction. */
5897 /* Argument deduction failed. */
5900 /* Instantiate the template. */
5904 /* Instantiation failed. */
5907 /* See if there's a match. */
5910 instantiation_type =
5916 }
5918 /* Now, remove all but the most specialized of the matches. */
5920 {
5925 }
5926 }
5928 /* Now we should have exactly one function in MATCHES. */
5930 {
5931 /* There were *no* matches. */
5933 {
5936 target_type);
5938 /* print_candidates expects a chain with the functions in
5939 TREE_VALUE slots, so we cons one up here (we're losing anyway,
5940 so why be clever?). */
5943 matches);
5946 }
5948 }
5950 {
5951 /* There were too many matches. */
5954 {
5955 tree match;
5959 target_type);
5961 /* Since print_candidates expects the functions in the
5962 TREE_VALUE slot, we flip them here. */
5967 }
5970 }
5972 /* Good, exactly one match. Now, convert it to the correct type. */
5977 {
5985 {
5988 }
5989 }
5994 else
5995 {
5996 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
5997 will mark the function as addressed, but here we must do it
5998 explicitly. */
6002 }
6003 }
6005 /* This function will instantiate the type of the expression given in
6006 RHS to match the type of LHSTYPE. If errors exist, then return
6007 error_mark_node. FLAGS is a bit mask. If ITF_COMPLAIN is set, then
6008 we complain on errors. If we are not complaining, never modify rhs,
6009 as overload resolution wants to try many possible instantiations, in
6010 the hope that at least one will work.
6012 For non-recursive calls, LHSTYPE should be a function, pointer to
6013 function, or a pointer to member function. */
6015 tree
6017 {
6026 {
6030 }
6033 {
6039 /* Microsoft allows `A::f' to be resolved to a
6040 pointer-to-member. */
6041 ;
6042 else
6043 {
6048 }
6049 }
6054 /* We don't overwrite rhs if it is an overloaded function.
6055 Copying it would destroy the tree link. */
6059 /* This should really only be used when attempting to distinguish
6060 what sort of a pointer to function we have. For now, any
6061 arithmetic operation which is not supported on pointers
6062 is rejected as an error. */
6065 {
6076 {
6077 tree new_rhs;
6087 }
6103 /* This can happen if we are forming a pointer-to-member for a
6104 member template. */
6107 /* Fall through. */
6110 {
6114 return
6116 fns,
6117 complain,
6118 allow_ptrmem,
6120 args);
6121 }
6125 return
6127 rhs,
6128 complain,
6129 allow_ptrmem,
6134 /* Now we should have a baselink. */
6140 /* This is too hard for now. */
6214 {
6218 }
6241 {
6246 }
6257 }
6258 }
6259 \f
6260 /* Return the name of the virtual function pointer field
6261 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6262 this may have to look back through base types to find the
6263 ultimate field name. (For single inheritance, these could
6264 all be the same name. Who knows for multiple inheritance). */
6266 static tree
6268 {
6283 }
6285 void
6287 {
6288 #ifdef GATHER_STATISTICS
6294 {
6299 }
6300 #endif
6301 }
6303 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6304 according to [class]:
6305 The class-name is also inserted
6306 into the scope of the class itself. For purposes of access checking,
6307 the inserted class name is treated as if it were a public member name. */
6309 void
6311 {
6314 tree saved_cas;
6327 }
6329 /* Returns 1 if TYPE contains only padding bytes. */
6331 int
6333 {
6340 /* In G++ 3.2, whether or not a class was empty was determined by
6341 looking at its size. */
6344 else
6346 }
6348 /* Returns true if TYPE contains an empty class. */
6350 static bool
6352 {
6356 {
6357 tree field;
6368 }
6372 }
6374 /* Find the enclosing class of the given NODE. NODE can be a *_DECL or
6375 a *_TYPE node. NODE can also be a local class. */
6377 tree
6379 {
6383 {
6385 {
6398 }
6399 }
6401 }
6403 /* Return 1 if TYPE or one of its enclosing classes is derived from BASE. */
6405 int
6407 {
6409 {
6414 }
6416 }
6418 /* Note that NAME was looked up while the current class was being
6419 defined and that the result of that lookup was DECL. */
6421 void
6423 {
6424 splay_tree names_used;
6426 /* If we're not defining a class, there's nothing to do. */
6430 /* If there's already a binding for this NAME, then we don't have
6431 anything to worry about. */
6443 }
6445 /* Note that NAME was declared (as DECL) in the current class. Check
6446 to see that the declaration is valid. */
6448 void
6450 {
6451 splay_tree names_used;
6452 splay_tree_node n;
6454 /* Look to see if we ever used this name. */
6455 names_used
6462 {
6463 /* [basic.scope.class]
6465 A name N used in a class S shall refer to the same declaration
6466 in its context and when re-evaluated in the completed scope of
6467 S. */
6472 }
6473 }
6475 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6476 Secondary vtables are merged with primary vtables; this function
6477 will return the VAR_DECL for the primary vtable. */
6479 tree
6481 {
6482 tree decl;
6486 {
6490 }
6494 }
6497 /* Returns the binfo for the primary base of BINFO. If the resulting
6498 BINFO is a virtual base, and it is inherited elsewhere in the
6499 hierarchy, then the returned binfo might not be the primary base of
6500 BINFO in the complete object. Check BINFO_PRIMARY_P or
6501 BINFO_LOST_PRIMARY_P to be sure. */
6503 tree
6505 {
6506 tree primary_base;
6507 tree result;
6515 }
6517 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6519 static int
6521 {
6525 }
6527 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6528 INDENT should be zero when called from the top level; it is
6529 incremented recursively. IGO indicates the next expected BINFO in
6530 inheritance graph ordering. */
6532 static tree
6535 tree binfo,
6536 tree igo,
6538 {
6540 tree base_binfos;
6547 {
6550 }
6565 {
6569 TFF_PLAIN_IDENTIFIER),
6571 }
6573 {
6576 }
6581 {
6585 {
6589 TFF_PLAIN_IDENTIFIER));
6590 }
6592 {
6596 TFF_PLAIN_IDENTIFIER));
6597 }
6599 {
6603 TFF_PLAIN_IDENTIFIER));
6604 }
6606 {
6610 TFF_PLAIN_IDENTIFIER));
6611 }
6615 }
6619 {
6624 {
6629 }
6630 }
6633 }
6635 /* Dump the BINFO hierarchy for T. */
6637 static void
6639 {
6658 }
6660 static void
6662 {
6663 tree inits;
6665 HOST_WIDE_INT elt;
6673 TFF_PLAIN_IDENTIFIER));
6680 }
6682 static void
6684 {
6692 {
6699 {
6703 }
6707 }
6710 }
6712 static void
6714 {
6722 {
6727 }
6730 }
6732 /* Virtual function table initialization. */
6734 /* Create all the necessary vtables for T and its base classes. */
6736 static void
6738 {
6739 tree list;
6740 tree vbase;
6742 /* We lay out the primary and secondary vtables in one contiguous
6743 vtable. The primary vtable is first, followed by the non-virtual
6744 secondary vtables in inheritance graph order. */
6749 /* Then come the virtual bases, also in inheritance graph order. */
6751 {
6755 }
6759 }
6761 /* Initialize the vtable for BINFO with the INITS. */
6763 static void
6765 {
6766 tree decl;
6772 }
6774 /* Initialize DECL (a declaration for a namespace-scope array) with
6775 the INITS. */
6777 static void
6779 {
6780 tree context;
6788 }
6790 /* Build the VTT (virtual table table) for T.
6791 A class requires a VTT if it has virtual bases.
6793 This holds
6794 1 - primary virtual pointer for complete object T
6795 2 - secondary VTTs for each direct non-virtual base of T which requires a
6796 VTT
6797 3 - secondary virtual pointers for each direct or indirect base of T which
6798 has virtual bases or is reachable via a virtual path from T.
6799 4 - secondary VTTs for each direct or indirect virtual base of T.
6801 Secondary VTTs look like complete object VTTs without part 4. */
6803 static void
6805 {
6806 tree inits;
6807 tree type;
6808 tree vtt;
6809 tree index;
6811 /* Build up the initializers for the VTT. */
6816 /* If we didn't need a VTT, we're done. */
6820 /* Figure out the type of the VTT. */
6824 /* Now, build the VTT object itself. */
6827 /* Add the VTT to the vtables list. */
6832 }
6834 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6835 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6836 and CHAIN the vtable pointer for this binfo after construction is
6837 complete. VALUE can also be another BINFO, in which case we recurse. */
6839 static tree
6841 {
6842 tree vt;
6845 {
6851 else
6853 }
6856 }
6858 /* Recursively build the VTT-initializer for BINFO (which is in the
6859 hierarchy dominated by T). INITS points to the end of the initializer
6860 list to date. INDEX is the VTT index where the next element will be
6861 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6862 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
6863 for virtual bases of T. When it is not so, we build the constructor
6864 vtables for the BINFO-in-T variant. */
6868 {
6870 tree b;
6871 tree init;
6872 tree secondary_vptrs;
6875 /* We only need VTTs for subobjects with virtual bases. */
6879 /* We need to use a construction vtable if this is not the primary
6880 VTT. */
6882 {
6885 /* Record the offset in the VTT where this sub-VTT can be found. */
6887 }
6889 /* Add the address of the primary vtable for the complete object. */
6894 {
6897 }
6900 /* Recursively add the secondary VTTs for non-virtual bases. */
6902 {
6907 }
6909 /* Add secondary virtual pointers for all subobjects of BINFO with
6910 either virtual bases or reachable along a virtual path, except
6911 subobjects that are non-virtual primary bases. */
6918 dfs_build_secondary_vptr_vtt_inits,
6919 NULL,
6920 dfs_ctor_vtable_bases_queue_p,
6921 secondary_vptrs);
6924 secondary_vptrs);
6928 /* The secondary vptrs come back in reverse order. After we reverse
6929 them, and add the INITS, the last init will be the first element
6930 of the chain. */
6933 {
6937 }
6939 /* Add the secondary VTTs for virtual bases. */
6942 {
6947 }
6950 {
6956 dfs_ctor_vtable_bases_queue_p,
6957 data);
6958 }
6961 }
6963 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo
6964 for the base in most derived. DATA is a TREE_LIST who's
6965 TREE_CHAIN is the type of the base being
6966 constructed whilst this secondary vptr is live. The TREE_UNSIGNED
6967 flag of DATA indicates that this is a constructor vtable. The
6968 TREE_TOP_LEVEL flag indicates that this is the primary VTT. */
6970 static tree
6972 {
6973 tree l;
6974 tree t;
6975 tree init;
6976 tree index;
6985 /* We don't care about bases that don't have vtables. */
6989 /* We're only interested in proper subobjects of T. */
6993 /* We're not interested in non-virtual primary bases. */
6997 /* If BINFO has virtual bases or is reachable via a virtual path
6998 from T, it'll have a secondary vptr. */
7003 /* Record the index where this secondary vptr can be found. */
7006 {
7009 }
7013 /* Add the initializer for the secondary vptr itself. */
7015 {
7016 /* It's a primary virtual base, and this is not the construction
7017 vtable. Find the base this is primary of in the inheritance graph,
7018 and use that base's vtable now. */
7021 }
7026 }
7028 /* dfs_walk_real predicate for building vtables. DATA is a TREE_LIST,
7029 VTT_MARKED_BINFO_P indicates whether marked or unmarked bases
7030 should be walked. TREE_PURPOSE is the TREE_TYPE that dominates the
7031 hierarchy. */
7033 static tree
7036 {
7042 }
7044 /* Called from build_vtt_inits via dfs_walk. After building constructor
7045 vtables and generating the sub-vtt from them, we need to restore the
7046 BINFO_VTABLES that were scribbled on. DATA is a TREE_LIST whose
7047 TREE_VALUE is the TREE_TYPE of the base whose sub vtt was generated. */
7049 static tree
7051 {
7054 /* We don't care about bases that don't have vtables. */
7058 /* If we scribbled the construction vtable vptr into BINFO, clear it
7059 out now. */
7067 }
7069 /* Build the construction vtable group for BINFO which is in the
7070 hierarchy dominated by T. */
7072 static void
7074 {
7075 tree list;
7076 tree type;
7077 tree vtbl;
7078 tree inits;
7079 tree id;
7080 tree vbase;
7082 /* See if we've already created this construction vtable group. */
7088 /* Build a version of VTBL (with the wrong type) for use in
7089 constructing the addresses of secondary vtables in the
7090 construction vtable group. */
7096 /* Add the vtables for each of our virtual bases using the vbase in T
7097 binfo. */
7099 vbase;
7101 {
7102 tree b;
7109 }
7112 /* Figure out the type of the construction vtable. */
7117 /* Initialize the construction vtable. */
7121 }
7123 /* Add the vtbl initializers for BINFO (and its bases other than
7124 non-virtual primaries) to the list of INITS. BINFO is in the
7125 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7126 the constructor the vtbl inits should be accumulated for. (If this
7127 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7128 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7129 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7130 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7131 but are not necessarily the same in terms of layout. */
7133 static void
7135 tree orig_binfo,
7136 tree rtti_binfo,
7137 tree t,
7138 tree inits)
7139 {
7147 /* If it doesn't have a vptr, we don't do anything. */
7151 /* If we're building a construction vtable, we're not interested in
7152 subobjects that don't require construction vtables. */
7158 /* Build the initializers for the BINFO-in-T vtable. */
7164 /* Walk the BINFO and its bases. We walk in preorder so that as we
7165 initialize each vtable we can figure out at what offset the
7166 secondary vtable lies from the primary vtable. We can't use
7167 dfs_walk here because we need to iterate through bases of BINFO
7168 and RTTI_BINFO simultaneously. */
7170 {
7173 /* Skip virtual bases. */
7179 inits);
7180 }
7181 }
7183 /* Called from accumulate_vtbl_inits. Returns the initializers for
7184 the BINFO vtable. */
7186 static tree
7188 tree orig_binfo,
7189 tree rtti_binfo,
7190 tree t,
7191 tree l)
7192 {
7199 {
7200 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7201 primary virtual base. If it is not the same primary in
7202 the hierarchy of T, we'll need to generate a ctor vtable
7203 for it, to place at its location in T. If it is the same
7204 primary, we still need a VTT entry for the vtable, but it
7205 should point to the ctor vtable for the base it is a
7206 primary for within the sub-hierarchy of RTTI_BINFO.
7208 There are three possible cases:
7210 1) We are in the same place.
7211 2) We are a primary base within a lost primary virtual base of
7212 RTTI_BINFO.
7213 3) We are primary to something not a base of RTTI_BINFO. */
7218 /* First, look through the bases we are primary to for RTTI_BINFO
7219 or a virtual base. */
7221 {
7225 }
7226 /* If we run out of primary links, keep looking down our
7227 inheritance chain; we might be an indirect primary. */
7233 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7234 base B and it is a base of RTTI_BINFO, this is case 2. In
7235 either case, we share our vtable with LAST, i.e. the
7236 derived-most base within B of which we are a primary. */
7240 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7241 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7242 binfo_ctor_vtable after everything's been set up. */
7245 /* Otherwise, this is case 3 and we get our own. */
7246 }
7251 {
7252 tree index;
7255 /* Compute the initializer for this vtable. */
7259 /* Figure out the position to which the VPTR should point. */
7262 vtbl_ptr_type_node,
7263 vtbl);
7270 index);
7273 }
7276 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7277 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7278 straighten this out. */
7282 else
7283 /* For an ordinary vtable, set BINFO_VTABLE. */
7287 }
7289 /* Construct the initializer for BINFO's virtual function table. BINFO
7290 is part of the hierarchy dominated by T. If we're building a
7291 construction vtable, the ORIG_BINFO is the binfo we should use to
7292 find the actual function pointers to put in the vtable - but they
7293 can be overridden on the path to most-derived in the graph that
7294 ORIG_BINFO belongs. Otherwise,
7295 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7296 BINFO that should be indicated by the RTTI information in the
7297 vtable; it will be a base class of T, rather than T itself, if we
7298 are building a construction vtable.
7300 The value returned is a TREE_LIST suitable for wrapping in a
7301 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7302 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7303 number of non-function entries in the vtable.
7305 It might seem that this function should never be called with a
7306 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7307 base is always subsumed by a derived class vtable. However, when
7308 we are building construction vtables, we do build vtables for
7309 primary bases; we need these while the primary base is being
7310 constructed. */
7312 static tree
7314 tree orig_binfo,
7315 tree t,
7316 tree rtti_binfo,
7318 {
7320 tree vfun_inits;
7321 tree vbase;
7322 vtbl_init_data vid;
7324 /* Initialize VID. */
7333 /* The first vbase or vcall offset is at index -3 in the vtable. */
7336 /* Add entries to the vtable for RTTI. */
7339 /* Create an array for keeping track of the functions we've
7340 processed. When we see multiple functions with the same
7341 signature, we share the vcall offsets. */
7343 /* Add the vcall and vbase offset entries. */
7345 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7346 build_vbase_offset_vtbl_entries. */
7348 vbase;
7352 /* If the target requires padding between data entries, add that now. */
7354 {
7358 {
7365 null_pointer_node),
7366 add);
7368 }
7369 }
7374 /* Go through all the ordinary virtual functions, building up
7375 initializers. */
7378 {
7379 tree delta;
7380 tree vcall_index;
7387 {
7391 }
7393 /* If the only definition of this function signature along our
7394 primary base chain is from a lost primary, this vtable slot will
7395 never be used, so just zero it out. This is important to avoid
7396 requiring extra thunks which cannot be generated with the function.
7398 We first check this in update_vtable_entry_for_fn, so we handle
7399 restored primary bases properly; we also need to do it here so we
7400 zero out unused slots in ctor vtables, rather than filling themff
7401 with erroneous values (though harmless, apart from relocation
7402 costs). */
7404 {
7405 /* We found a defn before a lost primary; go ahead as normal. */
7409 /* The nearest definition is from a lost primary; clear the
7410 slot. */
7412 {
7415 }
7416 }
7419 {
7420 /* Pull the offset for `this', and the function to call, out of
7421 the list. */
7428 /* You can't call an abstract virtual function; it's abstract.
7429 So, we replace these functions with __pure_virtual. */
7433 {
7437 }
7438 /* Take the address of the function, considering it to be of an
7439 appropriate generic type. */
7441 /* The address of a function can't change. */
7443 }
7445 /* And add it to the chain of initializers. */
7447 {
7452 else
7454 {
7461 }
7462 }
7463 else
7465 }
7467 /* The initializers for virtual functions were built up in reverse
7468 order; straighten them out now. */
7471 /* The negative offset initializers are also in reverse order. */
7474 /* Chain the two together. */
7476 }
7478 /* Adds to vid->inits the initializers for the vbase and vcall
7479 offsets in BINFO, which is in the hierarchy dominated by T. */
7481 static void
7483 {
7484 tree b;
7486 /* If this is a derived class, we must first create entries
7487 corresponding to the primary base class. */
7492 /* Add the vbase entries for this base. */
7494 /* Add the vcall entries for this base. */
7496 }
7498 /* Returns the initializers for the vbase offset entries in the vtable
7499 for BINFO (which is part of the class hierarchy dominated by T), in
7500 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7501 where the next vbase offset will go. */
7503 static void
7505 {
7506 tree vbase;
7507 tree t;
7508 tree non_primary_binfo;
7510 /* If there are no virtual baseclasses, then there is nothing to
7511 do. */
7517 /* We might be a primary base class. Go up the inheritance hierarchy
7518 until we find the most derived class of which we are a primary base:
7519 it is the offset of that which we need to use. */
7522 {
7523 tree b;
7525 /* If we have reached a virtual base, then it must be a primary
7526 base (possibly multi-level) of vid->binfo, or we wouldn't
7527 have called build_vcall_and_vbase_vtbl_entries for it. But it
7528 might be a lost primary, so just skip down to vid->binfo. */
7530 {
7533 }
7539 }
7541 /* Go through the virtual bases, adding the offsets. */
7543 vbase;
7545 {
7546 tree b;
7547 tree delta;
7552 /* Find the instance of this virtual base in the complete
7553 object. */
7556 /* If we've already got an offset for this virtual base, we
7557 don't need another one. */
7562 /* Figure out where we can find this vbase offset. */
7571 {
7572 /* The vbase offset had better be the same. */
7576 }
7578 /* The next vbase will come at a more negative offset. */
7582 /* The initializer is the delta from BINFO to this virtual base.
7583 The vbase offsets go in reverse inheritance-graph order, and
7584 we are walking in inheritance graph order so these end up in
7585 the right order. */
7591 vtable_entry_type,
7592 delta)));
7594 }
7595 }
7597 /* Adds the initializers for the vcall offset entries in the vtable
7598 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7599 to VID->INITS. */
7601 static void
7603 {
7604 /* We only need these entries if this base is a virtual base. We
7605 compute the indices -- but do not add to the vtable -- when
7606 building the main vtable for a class. */
7608 {
7609 /* We need a vcall offset for each of the virtual functions in this
7610 vtable. For example:
7612 class A { virtual void f (); };
7613 class B1 : virtual public A { virtual void f (); };
7614 class B2 : virtual public A { virtual void f (); };
7615 class C: public B1, public B2 { virtual void f (); };
7617 A C object has a primary base of B1, which has a primary base of A. A
7618 C also has a secondary base of B2, which no longer has a primary base
7619 of A. So the B2-in-C construction vtable needs a secondary vtable for
7620 A, which will adjust the A* to a B2* to call f. We have no way of
7621 knowing what (or even whether) this offset will be when we define B2,
7622 so we store this "vcall offset" in the A sub-vtable and look it up in
7623 a "virtual thunk" for B2::f.
7625 We need entries for all the functions in our primary vtable and
7626 in our non-virtual bases' secondary vtables. */
7628 /* If we are just computing the vcall indices -- but do not need
7629 the actual entries -- not that. */
7632 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7634 }
7635 }
7637 /* Build vcall offsets, starting with those for BINFO. */
7639 static void
7641 {
7643 tree primary_binfo;
7645 /* Don't walk into virtual bases -- except, of course, for the
7646 virtual base for which we are building vcall offsets. Any
7647 primary virtual base will have already had its offsets generated
7648 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7652 /* If BINFO has a primary base, process it first. */
7657 /* Add BINFO itself to the list. */
7660 /* Scan the non-primary bases of BINFO. */
7662 {
7663 tree base_binfo;
7668 }
7669 }
7671 /* Called from build_vcall_offset_vtbl_entries_r. */
7673 static void
7675 {
7676 /* Make entries for the rest of the virtuals. */
7678 {
7679 tree orig_fn;
7681 /* The ABI requires that the methods be processed in declaration
7682 order. G++ 3.2 used the order in the vtable. */
7684 orig_fn;
7688 }
7689 else
7690 {
7691 tree derived_virtuals;
7692 tree base_virtuals;
7693 tree orig_virtuals;
7694 /* If BINFO is a primary base, the most derived class which has
7695 BINFO as a primary base; otherwise, just BINFO. */
7696 tree non_primary_binfo;
7698 /* We might be a primary base class. Go up the inheritance hierarchy
7699 until we find the most derived class of which we are a primary base:
7700 it is the BINFO_VIRTUALS there that we need to consider. */
7703 {
7704 tree b;
7706 /* If we have reached a virtual base, then it must be vid->vbase,
7707 because we ignore other virtual bases in
7708 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7709 base (possibly multi-level) of vid->binfo, or we wouldn't
7710 have called build_vcall_and_vbase_vtbl_entries for it. But it
7711 might be a lost primary, so just skip down to vid->binfo. */
7713 {
7718 }
7724 }
7727 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7728 where rtti_binfo is the most derived type. */
7729 non_primary_binfo
7735 base_virtuals;
7739 {
7740 tree orig_fn;
7742 /* Find the declaration that originally caused this function to
7743 be present in BINFO_TYPE (binfo). */
7746 /* When processing BINFO, we only want to generate vcall slots for
7747 function slots introduced in BINFO. So don't try to generate
7748 one if the function isn't even defined in BINFO. */
7753 }
7754 }
7755 }
7757 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7759 static void
7761 {
7763 tree vcall_offset;
7765 /* If there is already an entry for a function with the same
7766 signature as FN, then we do not need a second vcall offset.
7767 Check the list of functions already present in the derived
7768 class vtable. */
7770 {
7771 tree derived_entry;
7775 /* We only use one vcall offset for virtual destructors,
7776 even though there are two virtual table entries. */
7780 }
7782 /* If we are building these vcall offsets as part of building
7783 the vtable for the most derived class, remember the vcall
7784 offset. */
7790 /* The next vcall offset will be found at a more negative
7791 offset. */
7795 /* Keep track of this function. */
7799 {
7800 tree base;
7801 tree fn;
7803 /* Find the overriding function. */
7807 integer_zero_node);
7808 else
7809 {
7812 /* The vbase we're working on is a primary base of
7813 vid->binfo. But it might be a lost primary, so its
7814 BINFO_OFFSET might be wrong, so we just use the
7815 BINFO_OFFSET from vid->binfo. */
7819 vcall_offset));
7820 }
7821 /* Add the intiailizer to the vtable. */
7824 }
7825 }
7827 /* Return vtbl initializers for the RTTI entries coresponding to the
7828 BINFO's vtable. The RTTI entries should indicate the object given
7829 by VID->rtti_binfo. */
7831 static void
7833 {
7834 tree b;
7835 tree t;
7836 tree basetype;
7837 tree offset;
7838 tree decl;
7839 tree init;
7844 /* To find the complete object, we will first convert to our most
7845 primary base, and then add the offset in the vtbl to that value. */
7849 {
7850 tree primary_base;
7855 }
7858 /* The second entry is the address of the typeinfo object. */
7861 else
7864 /* Convert the declaration to a type that can be stored in the
7865 vtable. */
7870 /* Add the offset-to-top entry. It comes earlier in the vtable that
7871 the the typeinfo entry. Convert the offset to look like a
7872 function pointer, so that we can put it in the vtable. */
7876 }