| blob | c14313c8bf8b196051cb2f2c44426e6c32a83244 |
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, 2004, 2005
4 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
12 any later version.
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
25 /* High-level class interface. */
41 /* The number of nested classes being processed. If we are not in the
42 scope of any class, this is zero. */
46 /* In order to deal with nested classes, we keep a stack of classes.
47 The topmost entry is the innermost class, and is the entry at index
48 CURRENT_CLASS_DEPTH */
51 /* The name of the class. */
52 tree name;
54 /* The _TYPE node for the class. */
55 tree type;
57 /* The access specifier pending for new declarations in the scope of
58 this class. */
59 tree access;
61 /* If were defining TYPE, the names used in this class. */
62 splay_tree names_used;
66 {
67 /* The base for which we're building initializers. */
68 tree binfo;
69 /* The type of the most-derived type. */
70 tree derived;
71 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
72 unless ctor_vtbl_p is true. */
73 tree rtti_binfo;
74 /* The negative-index vtable initializers built up so far. These
75 are in order from least negative index to most negative index. */
76 tree inits;
77 /* The last (i.e., most negative) entry in INITS. */
79 /* The binfo for the virtual base for which we're building
80 vcall offset initializers. */
81 tree vbase;
82 /* The functions in vbase for which we have already provided vcall
83 offsets. */
84 varray_type fns;
85 /* The vtable index of the next vcall or vbase offset. */
86 tree index;
87 /* Nonzero if we are building the initializer for the primary
88 vtable. */
90 /* Nonzero if we are building the initializer for a construction
91 vtable. */
93 /* True when adding vcall offset entries to the vtable. False when
94 merely computing the indices. */
98 /* The type of a function passed to walk_subobject_offsets. */
101 /* The stack itself. This is a dynamically resized array. The
102 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
106 /* An array of all local classes present in this translation unit, in
107 declaration order. */
108 varray_type local_classes;
182 tree);
185 vtbl_init_data *);
205 splay_tree_key k2);
214 /* Macros for dfs walking during vtt construction. See
215 dfs_ctor_vtable_bases_queue_p, dfs_build_secondary_vptr_vtt_inits
216 and dfs_fixup_binfo_vtbls. */
217 #define VTT_TOP_LEVEL_P(NODE) TREE_UNSIGNED (NODE)
218 #define VTT_MARKED_BINFO_P(NODE) TREE_USED (NODE)
220 /* Variables shared between class.c and call.c. */
222 #ifdef GATHER_STATISTICS
230 #endif
232 /* Convert to or from a base subobject. EXPR is an expression of type
233 `A' or `A*', an expression of type `B' or `B*' is returned. To
234 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
235 the B base instance within A. To convert base A to derived B, CODE
236 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
237 In this latter case, A must not be a morally virtual base of B.
238 NONNULL is true if EXPR is known to be non-NULL (this is only
239 needed when EXPR is of pointer type). CV qualifiers are preserved
240 from EXPR. */
242 tree
244 tree expr,
245 tree binfo,
247 {
250 tree probe;
251 tree offset;
252 tree target_type;
254 tree ptr_target_type;
262 {
266 }
279 {
283 }
286 /* This must happen before the call to save_expr. */
299 {
300 /* Going via virtual base V_BINFO. We need the static offset
301 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
302 V_BINFO. That offset is an entry in D_BINFO's vtable. */
303 tree v_offset;
306 {
307 /* In a base member initializer, we cannot rely on
308 the vtable being set up. We have to use the vtt_parm. */
316 v_offset);
318 }
319 else
327 v_offset);
338 /* Negative fixed_type_p means this is a constructor or destructor;
339 virtual base layout is fixed in in-charge [cd]tors, but not in
340 base [cd]tors. */
344 v_offset,
346 else
348 }
352 target_type = cp_build_qualified_type
362 else
371 expr);
374 }
376 /* Convert OBJECT to the base TYPE. If CHECK_ACCESS is true, an error
377 message is emitted if TYPE is inaccessible. OBJECT is assumed to
378 be non-NULL. */
380 tree
382 {
383 tree binfo;
387 NULL);
392 }
394 /* EXPR is an expression with class type. BASE is a base class (a
395 BINFO) of that class type. Returns EXPR, converted to the BASE
396 type. This function assumes that EXPR is the most derived class;
397 therefore virtual bases can be found at their static offsets. */
399 tree
401 {
402 tree expr_type;
406 {
407 tree pointer_type;
416 }
419 }
421 \f
422 /* Given an object INSTANCE, return an expression which yields the
423 vtable element corresponding to INDEX. There are many special
424 cases for INSTANCE which we take care of here, mainly to avoid
425 creating extra tree nodes when we don't have to. */
427 static tree
429 {
430 tree aref;
433 /* Try to figure out what a reference refers to, and
434 access its virtual function table directly. */
442 {
447 }
457 }
459 tree
461 {
465 }
467 /* Given an object INSTANCE, return an expression which yields a
468 function pointer corresponding to vtable element INDEX. */
470 tree
472 {
475 /* When using function descriptors, the address of the
476 vtable entry is treated as a function pointer. */
482 }
484 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
485 for the given TYPE. */
487 static tree
489 {
491 }
493 /* Return an IDENTIFIER_NODE for the name of the virtual table table
494 for TYPE. */
496 tree
498 {
500 }
502 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
503 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
504 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
506 static tree
508 {
509 tree decl;
512 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
513 now to avoid confusion in mangle_decl. */
523 /* At one time the vtable info was grabbed 2 words at a time. This
524 fails on sparc unless you have 8-byte alignment. (tiemann) */
531 }
533 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
534 or even complete. If this does not exist, create it. If COMPLETE is
535 nonzero, then complete the definition of it -- that will render it
536 impossible to actually build the vtable, but is useful to get at those
537 which are known to exist in the runtime. */
539 tree
541 {
542 tree decl;
551 {
554 }
557 }
559 /* Returns a copy of the BINFO_VIRTUALS list in BINFO. The
560 BV_VCALL_INDEX for each entry is cleared. */
562 static tree
564 {
565 tree copies;
566 tree t;
573 }
575 /* Build the primary virtual function table for TYPE. If BINFO is
576 non-NULL, build the vtable starting with the initial approximation
577 that it is the same as the one which is the head of the association
578 list. Returns a nonzero value if a new vtable is actually
579 created. */
581 static int
583 {
584 tree decl;
585 tree virtuals;
590 {
592 /* We have already created a vtable for this base, so there's
593 no need to do it again. */
600 }
601 else
602 {
605 }
607 #ifdef GATHER_STATISTICS
610 #endif
612 /* Initialize the association list for this type, based
613 on our first approximation. */
618 }
620 /* Give BINFO a new virtual function table which is initialized
621 with a skeleton-copy of its original initialization. The only
622 entry that changes is the `delta' entry, so we can really
623 share a lot of structure.
625 FOR_TYPE is the most derived type which caused this table to
626 be needed.
628 Returns nonzero if we haven't met BINFO before.
630 The order in which vtables are built (by calling this function) for
631 an object must remain the same, otherwise a binary incompatibility
632 can result. */
634 static int
636 {
638 /* We already created a vtable for this base. There's no need to
639 do it again. */
642 /* Remember that we've created a vtable for this BINFO, so that we
643 don't try to do so again. */
646 /* Make fresh virtual list, so we can smash it later. */
649 /* Secondary vtables are laid out as part of the same structure as
650 the primary vtable. */
653 }
655 /* Create a new vtable for BINFO which is the hierarchy dominated by
656 T. Return nonzero if we actually created a new vtable. */
658 static int
660 {
662 /* In this case, it is *type*'s vtable we are modifying. We start
663 with the approximation that its vtable is that of the
664 immediate base class. */
665 /* ??? This actually passes TYPE_BINFO (t), not the primary base binfo,
666 since we've updated DECL_CONTEXT (TYPE_VFIELD (t)) by now. */
668 t);
669 else
670 /* This is our very own copy of `basetype' to play with. Later,
671 we will fill in all the virtual functions that override the
672 virtual functions in these base classes which are not defined
673 by the current type. */
675 }
677 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
678 (which is in the hierarchy dominated by T) list FNDECL as its
679 BV_FN. DELTA is the required constant adjustment from the `this'
680 pointer where the vtable entry appears to the `this' required when
681 the function is actually called. */
683 static void
685 tree binfo,
686 tree fndecl,
687 tree delta,
689 {
690 tree v;
696 {
697 /* We need a new vtable for BINFO. */
699 {
700 /* If we really did make a new vtable, we also made a copy
701 of the BINFO_VIRTUALS list. Now, we have to find the
702 corresponding entry in that list. */
707 }
712 }
713 }
715 \f
716 /* Add method METHOD to class TYPE. If ERROR_P is true, we are adding
717 the method after the class has already been defined because a
718 declaration for it was seen. (Even though that is erroneous, we
719 add the method for improved error recovery.) */
721 void
723 {
727 tree method_vec;
738 /* Make a new method vector. We start with 8 entries. We must
739 allocate at least two (for constructors and destructors), and
740 we're going to end up with an assignment operator at some point
741 as well.
743 We could use a TREE_LIST for now, and convert it to a TREE_VEC
744 in finish_struct, but we would probably waste more memory
745 making the links in the list than we would by over-allocating
746 the size of the vector here. Furthermore, we would complicate
747 all the code that expects this to be a vector. */
753 /* Constructors and destructors go in special slots. */
757 {
766 }
767 else
768 {
771 /* See if we already have an entry with this name. */
773 {
781 {
785 /* If we need to move things up, see if there's
786 space. */
788 {
791 slot++;
792 }
794 }
797 }
800 {
801 /* We need a bigger method vector. */
803 tree new_vec;
805 /* In the non-error case, we are processing a class
806 definition. Double the size of the vector to give room
807 for new methods. */
810 /* In the error case, the vector is already complete. We
811 don't expect many errors, and the rest of the front-end
812 will get confused if there are empty slots in the vector. */
813 else
821 }
824 {
825 /* Type conversion operators have to come before ordinary
826 methods; add_conversions depends on this to speed up
827 looking for conversion operators. So, if necessary, we
828 slide some of the vector elements up. In theory, this
829 makes this algorithm O(N^2) but we don't expect many
830 conversion operators. */
833 else
835 {
839 /* There are no more entries in the vector, so we
840 can insert the new conversion operator here. */
844 /* We can insert the new function right at the
845 SLOTth position. */
847 }
852 /* There is nothing in the Ith slot, so we can avoid
853 moving anything. */
854 ;
855 else
856 {
857 /* We know the last slot in the vector is empty
858 because we know that at this point there's room
859 for a new function. */
864 }
865 }
866 }
869 /* TYPE is a template class. Don't issue any errors now; wait
870 until instantiation time to complain. */
871 ;
872 else
873 {
874 tree fns;
876 /* Check to see if we've already got this method. */
878 fns;
880 {
882 tree fn_type;
883 tree method_type;
884 tree parms1;
885 tree parms2;
890 /* [over.load] Member function declarations with the
891 same name and the same parameter types cannot be
892 overloaded if any of them is a static member
893 function declaration.
895 [namespace.udecl] When a using-declaration brings names
896 from a base class into a derived class scope, member
897 functions in the derived class override and/or hide member
898 functions with the same name and parameter types in a base
899 class (rather than conflicting). */
905 /* Compare the quals on the 'this' parm. Don't compare
906 the whole types, as used functions are treated as
907 coming from the using class in overload resolution. */
914 /* For templates, the template parms must be identical. */
931 {
933 /* Defer to the local function. */
935 else
936 {
940 /* We don't call duplicate_decls here to merge
941 the declarations because that will confuse
942 things if the methods have inline
943 definitions. In particular, we will crash
944 while processing the definitions. */
946 }
947 }
948 }
949 }
951 /* Actually insert the new method. */
955 /* Add the new binding. */
960 }
962 /* Subroutines of finish_struct. */
964 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
965 legit, otherwise return 0. */
967 static int
969 {
970 tree elem;
979 {
981 {
984 else
987 }
988 else
989 {
990 /* They're changing the access to the same thing they changed
991 it to before. That's OK. */
992 ;
993 }
994 }
995 else
996 {
1000 }
1002 }
1004 /* Process the USING_DECL, which is a member of T. */
1006 static void
1008 {
1011 tree access
1017 tree old_value;
1024 {
1031 }
1034 {
1037 }
1039 {
1042 }
1047 {
1050 }
1053 /* Ignore base type this came from. */
1058 {
1064 else
1066 }
1072 ;
1074 {
1076 /* It's OK to use functions from a base when there are functions with
1078 else
1079 {
1084 }
1085 }
1087 {
1091 }
1093 /* Make type T see field decl FDECL with access ACCESS. */
1096 {
1099 }
1100 else
1102 }
1103 \f
1104 /* Run through the base clases of T, updating
1105 CANT_HAVE_DEFAULT_CTOR_P, CANT_HAVE_CONST_CTOR_P, and
1106 NO_CONST_ASN_REF_P. Also set flag bits in T based on properties of
1107 the bases. */
1109 static void
1114 {
1118 tree binfos;
1124 /* An aggregate cannot have baseclasses. */
1128 {
1129 tree base_binfo;
1130 tree basetype;
1132 /* Figure out what base we're looking at. */
1136 /* If the type of basetype is incomplete, then we already
1137 complained about that fact (and we should have fixed it up as
1138 well). */
1140 {
1142 /* The base type is of incomplete type. It is
1143 probably best to pretend that it does not
1144 exist. */
1152 }
1154 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1155 here because the case of virtual functions but non-virtual
1156 dtor is handled in finish_struct_1. */
1160 basetype);
1162 /* If the base class doesn't have copy constructors or
1163 assignment operators that take const references, then the
1164 derived class cannot have such a member automatically
1165 generated. */
1171 /* Similarly, if the base class doesn't have a default
1172 constructor, then the derived class won't have an
1173 automatically generated default constructor. */
1176 {
1180 basetype);
1181 }
1184 /* A virtual base does not effect nearly emptiness. */
1185 ;
1187 {
1189 /* And if there is more than one nearly empty base, then the
1190 derived class is not nearly empty either. */
1192 else
1193 /* Remember we've seen one. */
1195 }
1197 /* If the base class is not empty or nearly empty, then this
1198 class cannot be nearly empty. */
1201 /* A lot of properties from the bases also apply to the derived
1202 class. */
1212 }
1213 }
1215 /* Set BINFO_PRIMARY_BASE_OF for all binfos in the hierarchy
1216 dominated by TYPE that are primary bases. */
1218 static void
1220 {
1221 tree binfo;
1223 /* Walk the bases in inheritance graph order. */
1225 {
1232 else
1233 {
1235 /* A virtual binfo might have been copied from within
1236 another hierarchy. As we're about to use it as a primary
1237 base, make sure the offsets match. */
1239 {
1246 }
1247 }
1248 }
1249 }
1251 /* Make the BINFO the primary base of T. */
1253 static void
1255 {
1256 tree basetype;
1263 }
1265 /* Determine the primary class for T. */
1267 static void
1269 {
1271 tree vbases;
1272 tree type_binfo;
1274 /* If there are no baseclasses, there is certainly no primary base. */
1281 {
1286 {
1287 /* We prefer a non-virtual base, although a virtual one will
1288 do. */
1293 {
1296 }
1297 else
1298 {
1299 tree vfields;
1301 /* Only add unique vfields, and flatten them out as we go. */
1303 vfields;
1311 }
1312 }
1313 }
1318 /* Find the indirect primary bases - those virtual bases which are primary
1319 bases of something else in this hierarchy. */
1321 vbases;
1323 {
1326 /* See if this virtual base is an indirect primary base. To be so,
1327 it must be a primary base within the hierarchy of one of our
1328 direct bases. */
1330 {
1332 tree v;
1335 v;
1337 {
1343 {
1346 }
1347 }
1349 /* If we've discovered that this virtual base is an indirect
1350 primary base, then we can move on to the next virtual
1351 base. */
1354 }
1355 }
1357 /* A "nearly-empty" virtual base class can be the primary base
1358 class, if no non-virtual polymorphic base can be found. */
1360 {
1361 /* If not NULL, this is the best primary base candidate we have
1362 found so far. */
1364 tree base_binfo;
1366 /* Loop over the baseclasses. */
1368 base_binfo;
1370 {
1375 {
1376 /* If this is not an indirect primary base, then it's
1377 definitely our primary base. */
1379 {
1382 }
1384 /* If this is an indirect primary base, it still could be
1385 our primary base -- unless we later find there's another
1386 nearly-empty virtual base that isn't an indirect
1387 primary base. */
1390 }
1391 }
1393 /* If we've got a primary base, use it. */
1395 {
1399 }
1400 }
1402 /* Mark the primary base classes at this point. */
1404 }
1405 \f
1406 /* Set memoizing fields and bits of T (and its variants) for later
1407 use. */
1409 static void
1411 {
1414 /* Fix up variants (if any). */
1417 {
1418 /* These fields are in the _TYPE part of the node, not in
1419 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1430 /* Copy whatever these are holding today. */
1437 }
1440 /* For a class w/o baseclasses, `finish_struct' has set
1441 CLASS_TYPE_ABSTRACT_VIRTUALS correctly (by
1442 definition). Similarly for a class whose base classes do not
1443 have vtables. When neither of these is true, we might have
1444 removed abstract virtuals (by providing a definition), added
1445 some (by declaring new ones), or redeclared ones from a base
1446 class. We need to recalculate what's really an abstract virtual
1447 at this point (by looking in the vtables). */
1451 {
1452 /* Notice whether this class has type conversion functions defined. */
1455 tree basetype;
1458 {
1462 }
1463 }
1465 /* If this type has a copy constructor or a destructor, force its mode to
1466 be BLKmode, and force its TREE_ADDRESSABLE bit to be nonzero. This
1467 will cause it to be passed by invisible reference and prevent it from
1468 being returned in a register. */
1470 {
1471 tree variants;
1474 {
1477 }
1478 }
1479 }
1481 /* Issue warnings about T having private constructors, but no friends,
1482 and so forth.
1484 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1485 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1486 non-private static member functions. */
1488 static void
1490 {
1493 tree fn;
1496 /* If the class has friends, those entities might create and
1497 access instances, so we should not warn. */
1500 /* We will have warned when the template was declared; there's
1501 no need to warn on every instantiation. */
1503 /* There's no reason to even consider warning about this
1504 class. */
1507 /* We only issue one warning, if more than one applies, because
1508 otherwise, on code like:
1510 class A {
1511 // Oops - forgot `public:'
1512 A();
1513 A(const A&);
1514 ~A();
1515 };
1517 we warn several times about essentially the same problem. */
1519 /* Check to see if all (non-constructor, non-destructor) member
1520 functions are private. (Since there are no friends or
1521 non-private statics, we can't ever call any of the private member
1522 functions.) */
1524 /* We're not interested in compiler-generated methods; they don't
1525 provide any way to call private members. */
1527 {
1529 {
1531 /* A non-private static member function is just like a
1532 friend; it can create and invoke private member
1533 functions, and be accessed without a class
1534 instance. */
1538 /* Keep searching for a static member function. */
1539 }
1542 }
1545 {
1546 /* There are no non-private methods, and there's at least one
1547 private member function that isn't a constructor or
1548 destructor. (If all the private members are
1549 constructors/destructors we want to use the code below that
1550 issues error messages specifically referring to
1551 constructors/destructors.) */
1557 {
1560 }
1562 {
1565 }
1566 }
1568 /* Even if some of the member functions are non-private, the class
1569 won't be useful for much if all the constructors or destructors
1570 are private: such an object can never be created or destroyed. */
1573 {
1575 t);
1577 }
1580 {
1583 /* If a non-template class does not define a copy
1584 constructor, one is defined for it, enabling it to avoid
1585 this warning. For a template class, this does not
1586 happen, and so we would normally get a warning on:
1588 template <class T> class C { private: C(); };
1590 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1591 complete non-template or fully instantiated classes have this
1592 flag set. */
1595 else
1597 fn;
1599 {
1601 /* Ideally, we wouldn't count copy constructors (or, in
1602 fact, any constructor that takes an argument of the
1603 class type as a parameter) because such things cannot
1604 be used to construct an instance of the class unless
1605 you already have one. But, for now at least, we're
1606 more generous. */
1608 {
1611 }
1612 }
1615 {
1617 t);
1619 }
1620 }
1621 }
1624 gt_pointer_operator new_value;
1628 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1630 static int
1632 {
1645 }
1647 /* This routine compares two fields like method_name_cmp but using the
1648 pointer operator in resort_field_decl_data. */
1650 static int
1652 {
1661 {
1668 }
1670 }
1672 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1674 void
1677 gt_pointer_operator new_value,
1679 {
1684 /* The type conversion ops have to live at the front of the vec, so we
1685 can't sort them. */
1687 {
1692 }
1694 {
1698 resort_method_name_cmp);
1699 }
1700 }
1702 /* Warn about duplicate methods in fn_fields. Also compact method
1703 lists so that lookup can be made faster.
1705 Data Structure: List of method lists. The outer list is a
1706 TREE_LIST, whose TREE_PURPOSE field is the field name and the
1707 TREE_VALUE is the DECL_CHAIN of the FUNCTION_DECLs. TREE_CHAIN
1708 links the entire list of methods for TYPE_METHODS. Friends are
1709 chained in the same way as member functions (? TREE_CHAIN or
1710 DECL_CHAIN), but they live in the TREE_TYPE field of the outer
1711 list. That allows them to be quickly deleted, and requires no
1712 extra storage.
1714 Sort methods that are not special (i.e., constructors, destructors,
1715 and type conversion operators) so that we can find them faster in
1716 search. */
1718 static void
1720 {
1721 tree fn_fields;
1722 tree method_vec;
1726 {
1727 /* Clear these for safety; perhaps some parsing error could set
1728 these incorrectly. */
1733 }
1739 /* First fill in entry 0 with the constructors, entry 1 with destructors,
1740 and the next few with type conversion operators (if any). */
1743 /* Clear out this flag. */
1747 /* We thought there was a destructor, but there wasn't. Some
1748 parse errors cause this anomalous situation. */
1751 /* Issue warnings about private constructors and such. If there are
1752 no methods, then some public defaults are generated. */
1755 /* Now sort the methods. */
1757 len--;
1760 /* The type conversion ops have to live at the front of the vec, so we
1761 can't sort them. */
1763 {
1768 }
1771 method_name_cmp);
1772 }
1774 /* Make BINFO's vtable have N entries, including RTTI entries,
1775 vbase and vcall offsets, etc. Set its type and call the backend
1776 to lay it out. */
1778 static void
1780 {
1781 tree atype;
1782 tree vtable;
1788 /* We may have to grow the vtable. */
1791 {
1795 }
1796 }
1798 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1799 have the same signature. */
1801 int
1803 {
1804 /* One destructor overrides another if they are the same kind of
1805 destructor. */
1809 /* But a non-destructor never overrides a destructor, nor vice
1810 versa, nor do different kinds of destructors override
1811 one-another. For example, a complete object destructor does not
1812 override a deleting destructor. */
1821 {
1829 }
1831 }
1833 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1834 subobject. */
1836 static bool
1838 {
1839 tree probe;
1842 {
1846 /* If we meet a virtual base, we can't follow the inheritance
1847 any more. See if the complete type of DERIVED contains
1848 such a virtual base. */
1852 }
1854 }
1857 /* The depth of the current subobject, with "1" as the depth of the
1858 most derived object in the hierarchy. */
1860 /* The maximum depth found so far. */
1864 /* Called from find_final_overrider via dfs_walk. */
1866 static tree
1868 {
1874 }
1876 /* Called from find_final_overrider via dfs_walk. */
1878 static tree
1880 {
1884 }
1887 /* The function for which we are trying to find a final overrider. */
1888 tree fn;
1889 /* The base class in which the function was declared. */
1890 tree declaring_base;
1891 /* The most derived class in the hierarchy. */
1892 tree most_derived_type;
1893 /* The candidate overriders. */
1894 tree candidates;
1895 /* Each entry in this array is the next-most-derived class for a
1896 virtual base class along the current path. */
1898 /* A pointer one past the top of the VPATH_LIST. */
1902 /* Add the overrider along the current path to FFOD->CANDIDATES.
1903 Returns true if an overrider was found; false otherwise. */
1905 static bool
1909 {
1910 tree method;
1912 /* If BINFO is not the most derived type, try a more derived class.
1913 A definition there will overrider a definition here. */
1915 {
1916 tree derived;
1920 else
1924 }
1928 {
1931 /* Remove any candidates overridden by this new function. */
1933 {
1934 /* If *CANDIDATE overrides METHOD, then METHOD
1935 cannot override anything else on the list. */
1938 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1941 else
1943 }
1945 /* Add the new function. */
1948 }
1951 }
1953 /* Called from find_final_overrider via dfs_walk. */
1955 static tree
1957 {
1964 }
1966 static tree
1968 {
1976 }
1978 static tree
1980 {
1987 }
1989 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1990 FN and whose TREE_VALUE is the binfo for the base where the
1991 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1992 DERIVED) is the base object in which FN is declared. */
1994 static tree
1996 {
1997 find_final_overrider_data ffod;
1998 count_depth_data cd;
2000 /* Getting this right is a little tricky. This is valid:
2002 struct S { virtual void f (); };
2003 struct T { virtual void f (); };
2004 struct U : public S, public T { };
2006 even though calling `f' in `U' is ambiguous. But,
2008 struct R { virtual void f(); };
2009 struct S : virtual public R { virtual void f (); };
2010 struct T : virtual public R { virtual void f (); };
2011 struct U : public S, public T { };
2013 is not -- there's no way to decide whether to put `S::f' or
2014 `T::f' in the vtable for `R'.
2016 The solution is to look at all paths to BINFO. If we find
2017 different overriders along any two, then there is a problem. */
2021 /* Determine the depth of the hierarchy. */
2034 dfs_find_final_overrider,
2035 dfs_find_final_overrider_post,
2036 dfs_find_final_overrider_q,
2041 /* If there was no winner, issue an error message. */
2046 }
2048 /* Return the index of the vcall offset for FN when TYPE is used as a
2049 virtual base. */
2051 static tree
2053 {
2054 tree v;
2061 /* There should always be an appropriate index. */
2065 }
2067 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2068 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2069 corresponding position in the BINFO_VIRTUALS list. */
2071 static void
2074 {
2075 tree b;
2076 tree overrider;
2077 tree delta;
2078 tree virtual_base;
2079 tree first_defn;
2085 /* Find the nearest primary base (possibly binfo itself) which defines
2086 this function; this is the class the caller will convert to when
2087 calling FN through BINFO. */
2089 {
2094 /* The nearest definition is from a lost primary. */
2097 }
2100 /* Find the final overrider. */
2103 {
2106 }
2109 /* Check for adjusting covariant return types. */
2117 {
2118 /* If FN is a covariant thunk, we must figure out the adjustment
2119 to the final base FN was converting to. As OVERRIDER_TARGET might
2120 also be converting to the return type of FN, we have to
2121 combine the two conversions here. */
2128 {
2132 }
2133 else
2137 /* Find the equivalent binfo within the return type of the
2138 overriding function. We will want the vbase offset from
2139 there. */
2140 virtual_offset =
2146 {
2147 /* There was no existing virtual thunk (which takes
2148 precedence). So find the binfo of the base function's
2149 return type within the overriding function's return type.
2150 We cannot call lookup base here, because we're inside a
2151 dfs_walk, and will therefore clobber the BINFO_MARKED
2152 flags. Fortunately we know the covariancy is valid (it
2153 has already been checked), so we can just iterate along
2154 the binfos, which have been chained in inheritance graph
2155 order. Of course it is lame that we have to repeat the
2156 search here anyway -- we should really be caching pieces
2157 of the vtable and avoiding this repeated work. */
2160 /* Find the base binfo within the overriding function's
2161 return type. We will always find a thunk_binfo, except
2162 when the covariancy is invalid (which we will have
2163 already diagnosed). */
2166 thunk_binfo;
2172 /* See if virtual inheritance is involved. */
2174 virtual_offset;
2181 {
2185 {
2186 /* We convert via virtual base. Adjust the fixed
2187 offset to be from there. */
2188 offset = size_diffop
2191 }
2193 /* There was an existing fixed offset, this must be
2194 from the base just converted to, and the base the
2195 FN was thunking to. */
2197 else
2199 }
2200 }
2203 /* Replace the overriding function with a covariant thunk. We
2204 will emit the overriding function in its own slot as
2205 well. */
2208 }
2209 else
2212 /* Assume that we will produce a thunk that convert all the way to
2213 the final overrider, and not to an intermediate virtual base. */
2216 /* See if we can convert to an intermediate virtual base first, and then
2217 use the vcall offset located there to finish the conversion. */
2219 {
2220 /* If we find the final overrider, then we can stop
2221 walking. */
2226 /* If we find a virtual base, and we haven't yet found the
2227 overrider, then there is a virtual base between the
2228 declaring base (first_defn) and the final overrider. */
2230 {
2233 }
2234 }
2237 {
2238 /* The ABI specifies that a covariant thunk includes a mangling
2239 for a this pointer adjustment. This-adjusting thunks that
2240 override a function from a virtual base have a vcall
2241 adjustment. When the virtual base in question is a primary
2242 virtual base, we know the adjustments are zero, (and in the
2243 non-covariant case, we would not use the thunk).
2244 Unfortunately we didn't notice this could happen, when
2245 designing the ABI and so never mandated that such a covariant
2246 thunk should be emitted. Because we must use the ABI mandated
2247 name, we must continue searching from the binfo where we
2248 found the most recent definition of the function, towards the
2249 primary binfo which first introduced the function into the
2250 vtable. If that enters a virtual base, we must use a vcall
2251 this-adjusting thunk. Bleah! */
2260 /* Even if we find a virtual base, the correct delta is
2261 between the overrider and the binfo we're building a vtable
2262 for. */
2264 }
2266 /* Compute the constant adjustment to the `this' pointer. The
2267 `this' pointer, when this function is called, will point at BINFO
2268 (or one of its primary bases, which are at the same offset). */
2270 /* The `this' pointer needs to be adjusted from the declaration to
2271 the nearest virtual base. */
2275 /* If the nearest definition is in a lost primary, we don't need an
2276 entry in our vtable. Except possibly in a constructor vtable,
2277 if we happen to get our primary back. In that case, the offset
2278 will be zero, as it will be a primary base. */
2280 else
2281 /* The `this' pointer needs to be adjusted from pointing to
2282 BINFO to pointing at the base where the final overrider
2283 appears. */
2284 virtual_covariant:
2294 }
2296 /* Called from modify_all_vtables via dfs_walk. */
2298 static tree
2300 {
2302 primary base; we're not going to use that vtable anyhow.
2303 We do still need to do this for virtual primary bases, as they
2304 could become non-primary in a construction vtable. */
2306 /* Similarly, a base without a vtable needs no modification. */
2308 {
2310 tree virtuals;
2311 tree old_virtuals;
2316 /* Now, go through each of the virtual functions in the virtual
2317 function table for BINFO. Find the final overrider, and
2318 update the BINFO_VIRTUALS list appropriately. */
2321 virtuals;
2325 binfo,
2328 }
2333 }
2335 /* Update all of the primary and secondary vtables for T. Create new
2336 vtables as required, and initialize their RTTI information. Each
2337 of the functions in VIRTUALS is declared in T and may override a
2338 virtual function from a base class; find and modify the appropriate
2339 entries to point to the overriding functions. Returns a list, in
2340 declaration order, of the virtual functions that are declared in T,
2341 but do not appear in the primary base class vtable, and which
2342 should therefore be appended to the end of the vtable for T. */
2344 static tree
2346 {
2350 /* Update all of the vtables. */
2354 /* Add virtual functions not already in our primary vtable. These
2355 will be both those introduced by this class, and those overridden
2356 from secondary bases. It does not include virtuals merely
2357 inherited from secondary bases. */
2359 {
2364 {
2365 /* We don't need to adjust the `this' pointer when
2366 calling this function. */
2370 /* This is a function not already in our vtable. Keep it. */
2372 }
2373 else
2374 /* We've already got an entry for this function. Skip it. */
2376 }
2379 }
2381 /* Get the base virtual function declarations in T that have the
2382 indicated NAME. */
2384 static tree
2386 {
2387 tree methods;
2392 /* Find virtual functions in T with the indicated NAME. */
2396 methods;
2398 {
2404 }
2410 {
2413 base_fndecls);
2414 }
2417 }
2419 /* If this declaration supersedes the declaration of
2420 a method declared virtual in the base class, then
2421 mark this field as being virtual as well. */
2423 static void
2425 {
2427 /* In [temp.mem] we have:
2429 A specialization of a member function template does not
2430 override a virtual function from a base class. */
2437 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2438 the error_mark_node so that we know it is an overriding
2439 function. */
2443 {
2447 }
2448 }
2450 /* Warn about hidden virtual functions that are not overridden in t.
2451 We know that constructors and destructors don't apply. */
2453 void
2455 {
2460 /* We go through each separately named virtual function. */
2462 {
2463 tree fns;
2464 tree name;
2465 tree fndecl;
2466 tree base_fndecls;
2469 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2470 have the same name. Figure out what name that is. */
2472 /* There are no possibly hidden functions yet. */
2474 /* Iterate through all of the base classes looking for possibly
2475 hidden functions. */
2477 {
2480 base_fndecls);
2481 }
2483 /* If there are no functions to hide, continue. */
2487 /* Remove any overridden functions. */
2489 {
2492 {
2496 /* If the method from the base class has the same
2497 signature as the method from the derived class, it
2498 has been overridden. */
2501 else
2503 }
2504 }
2506 /* Now give a warning for all base functions without overriders,
2507 as they are hidden. */
2509 {
2510 /* Here we know it is a hider, and no overrider exists. */
2515 }
2516 }
2517 }
2519 /* Check for things that are invalid. There are probably plenty of other
2520 things we should check for also. */
2522 static void
2524 {
2525 tree field;
2528 {
2536 {
2539 {
2540 /* We're generally only interested in entities the user
2541 declared, but we also find nested classes by noticing
2542 the TYPE_DECL that we create implicitly. You're
2543 allowed to put one anonymous union inside another,
2544 though, so we explicitly tolerate that. We use
2545 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2546 we also allow unnamed types used for defining fields. */
2553 {
2555 elt);
2557 }
2561 elt);
2564 elt);
2568 }
2569 }
2570 }
2571 }
2573 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2574 will be used later during class template instantiation.
2575 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2576 a non-static member data (FIELD_DECL), a member function
2577 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2578 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2579 When FRIEND_P is nonzero, T is either a friend class
2580 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2581 (FUNCTION_DECL, TEMPLATE_DECL). */
2583 void
2585 {
2586 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2591 }
2593 /* Create default constructors, assignment operators, and so forth for
2594 the type indicated by T, if they are needed.
2595 CANT_HAVE_DEFAULT_CTOR, CANT_HAVE_CONST_CTOR, and
2596 CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, the
2597 class cannot have a default constructor, copy constructor taking a
2598 const reference argument, or an assignment operator taking a const
2599 reference, respectively. If a virtual destructor is created, its
2600 DECL is returned; otherwise the return value is NULL_TREE. */
2602 static void
2607 {
2608 tree default_fn;
2615 /* Destructor. */
2617 {
2621 /* If we couldn't make it work, then pretend we didn't need it. */
2624 else
2625 {
2631 }
2632 }
2633 else
2634 /* Any non-implicit destructor is non-trivial. */
2637 /* Default constructor. */
2639 {
2643 }
2645 /* Copy constructor. */
2647 {
2648 /* ARM 12.18: You get either X(X&) or X(const X&), but
2649 not both. --Chip */
2650 default_fn
2655 }
2657 /* Assignment operator. */
2659 {
2660 default_fn
2665 }
2667 /* Now, hook all of the new functions on to TYPE_METHODS,
2668 and add them to the CLASSTYPE_METHOD_VEC. */
2670 {
2673 }
2675 /* G++ 3.2 put the implicit destructor at the *beginning* of the
2676 list, which cause the destructor to be emitted in an incorrect
2677 location in the vtable. */
2679 else
2680 {
2683 "and may change in a future version of GCC due to implicit "
2685 t);
2688 }
2691 }
2693 /* Subroutine of finish_struct_1. Recursively count the number of fields
2694 in TYPE, including anonymous union members. */
2696 static int
2698 {
2699 tree x;
2702 {
2705 else
2707 }
2709 }
2711 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2712 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2714 static int
2716 {
2717 tree x;
2719 {
2722 else
2724 }
2726 }
2728 /* FIELD is a bit-field. We are finishing the processing for its
2729 enclosing type. Issue any appropriate messages and set appropriate
2730 flags. */
2732 static void
2734 {
2738 /* Detect invalid bit-field type. */
2741 {
2744 }
2746 /* Detect and ignore out of range field width. */
2748 {
2751 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2754 /* detect invalid field size. */
2757 else
2761 {
2763 field);
2765 }
2767 {
2770 }
2772 {
2775 }
2785 min_precision
2790 }
2792 /* Remove the bit-field width indicator so that the rest of the
2793 compiler does not treat that value as an initializer. */
2797 {
2800 }
2801 else
2802 {
2803 /* Non-bit-fields are aligned for their type. */
2806 }
2807 }
2809 /* FIELD is a non bit-field. We are finishing the processing for its
2810 enclosing type T. Issue any appropriate messages and set appropriate
2811 flags. */
2813 static void
2815 tree t,
2820 {
2823 /* An anonymous union cannot contain any fields which would change
2824 the settings of CANT_HAVE_CONST_CTOR and friends. */
2826 ;
2827 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2828 structs. So, we recurse through their fields here. */
2830 {
2831 tree fields;
2837 any_default_members);
2838 }
2839 /* Check members with class type for constructors, destructors,
2840 etc. */
2842 {
2843 /* Never let anything with uninheritable virtuals
2844 make it through without complaint. */
2848 {
2851 field);
2854 field);
2857 field);
2858 }
2859 else
2860 {
2866 }
2877 }
2879 {
2880 /* `build_class_init_list' does not recognize
2881 non-FIELD_DECLs. */
2885 }
2886 }
2888 /* Check the data members (both static and non-static), class-scoped
2889 typedefs, etc., appearing in the declaration of T. Issue
2890 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2891 declaration order) of access declarations; each TREE_VALUE in this
2892 list is a USING_DECL.
2894 In addition, set the following flags:
2896 EMPTY_P
2897 The class is empty, i.e., contains no non-static data members.
2899 CANT_HAVE_DEFAULT_CTOR_P
2900 This class cannot have an implicitly generated default
2901 constructor.
2903 CANT_HAVE_CONST_CTOR_P
2904 This class cannot have an implicitly generated copy constructor
2905 taking a const reference.
2907 CANT_HAVE_CONST_ASN_REF
2908 This class cannot have an implicitly generated assignment
2909 operator taking a const reference.
2911 All of these flags should be initialized before calling this
2912 function.
2914 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2915 fields can be added by adding to this chain. */
2917 static void
2922 {
2928 /* Assume there are no access declarations. */
2930 /* Assume this class has no pointer members. */
2932 /* Assume none of the members of this class have default
2933 initializations. */
2937 {
2944 {
2946 {
2948 cp_warning_at
2950 x);
2951 else
2953 }
2956 /* We don't treat zero-width bitfields as making a class
2957 non-empty. */
2958 ;
2959 else
2960 {
2961 tree element_type;
2963 /* The class is non-empty. */
2965 /* The class is not even nearly empty. */
2967 /* If one of the data members contains an empty class,
2968 so does T. */
2973 }
2974 }
2977 {
2978 /* Prune the access declaration from the list of fields. */
2981 /* Save the access declarations for our caller. */
2984 /* Since we've reset *FIELD there's no reason to skip to the
2985 next field. */
2988 }
2994 /* If we've gotten this far, it's a data member, possibly static,
2995 or an enumerator. */
2998 /* When this goes into scope, it will be a non-local reference. */
3002 {
3003 /* [class.union]
3005 If a union contains a static data member, or a member of
3006 reference type, the program is ill-formed. */
3008 {
3011 }
3013 {
3017 }
3018 }
3020 /* ``A local class cannot have static data members.'' ARM 9.4 */
3024 /* Perform error checking that did not get done in
3025 grokdeclarator. */
3027 {
3029 x);
3032 }
3034 {
3038 }
3046 /* Now it can only be a FIELD_DECL. */
3051 /* If this is of reference type, check if it needs an init.
3052 Also do a little ANSI jig if necessary. */
3054 {
3059 /* ARM $12.6.2: [A member initializer list] (or, for an
3060 aggregate, initialization by a brace-enclosed list) is the
3061 only way to initialize nonstatic const and reference
3062 members. */
3069 }
3077 {
3082 }
3088 /* DR 148 now allows pointers to members (which are POD themselves),
3089 to be allowed in POD structs. */
3095 /* If any field is const, the structure type is pseudo-const. */
3097 {
3102 /* ARM $12.6.2: [A member initializer list] (or, for an
3103 aggregate, initialization by a brace-enclosed list) is the
3104 only way to initialize nonstatic const and reference
3105 members. */
3112 }
3113 /* A field that is pseudo-const makes the structure likewise. */
3115 {
3120 }
3122 /* Core issue 80: A nonstatic data member is required to have a
3123 different name from the class iff the class has a
3124 user-defined constructor. */
3128 /* We set DECL_C_BIT_FIELD in grokbitfield.
3129 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3132 else
3134 cant_have_const_ctor_p,
3135 cant_have_default_ctor_p,
3136 no_const_asn_ref_p,
3138 }
3140 /* Effective C++ rule 11. */
3143 {
3147 {
3151 }
3154 }
3157 /* Check anonymous struct/anonymous union fields. */
3160 /* We've built up the list of access declarations in reverse order.
3161 Fix that now. */
3163 }
3165 /* If TYPE is an empty class type, records its OFFSET in the table of
3166 OFFSETS. */
3168 static int
3170 {
3171 splay_tree_node n;
3176 /* Record the location of this empty object in OFFSETS. */
3184 type,
3188 }
3190 /* Returns nonzero if TYPE is an empty class type and there is
3191 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3193 static int
3195 {
3196 splay_tree_node n;
3197 tree t;
3202 /* Record the location of this empty object in OFFSETS. */
3212 }
3214 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3215 F for every subobject, passing it the type, offset, and table of
3216 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3217 be traversed.
3219 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3220 than MAX_OFFSET will not be walked.
3222 If F returns a nonzero value, the traversal ceases, and that value
3223 is returned. Otherwise, returns zero. */
3225 static int
3227 subobject_offset_fn f,
3228 tree offset,
3229 splay_tree offsets,
3230 tree max_offset,
3232 {
3236 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3237 stop. */
3242 {
3246 }
3249 {
3250 tree field;
3251 tree binfo;
3254 /* Avoid recursing into objects that are not interesting. */
3258 /* Record the location of TYPE. */
3263 /* Iterate through the direct base classes of TYPE. */
3267 {
3268 tree binfo_offset;
3283 offset,
3285 else
3286 {
3287 tree orig_binfo;
3288 /* We cannot rely on BINFO_OFFSET being set for the base
3289 class yet, but the offsets for direct non-virtual
3290 bases can be calculated by going back to the TYPE. */
3293 offset,
3295 }
3298 f,
3299 binfo_offset,
3300 offsets,
3301 max_offset,
3306 }
3309 {
3310 tree vbase;
3312 /* Iterate through the virtual base classes of TYPE. In G++
3313 3.2, we included virtual bases in the direct base class
3314 loop above, which results in incorrect results; the
3315 correct offsets for virtual bases are only known when
3316 working with the most derived type. */
3319 vbase;
3321 {
3324 f,
3326 offset,
3328 offsets,
3329 max_offset,
3333 }
3334 else
3335 {
3336 /* We still have to walk the primary base, if it is
3337 virtual. (If it is non-virtual, then it was walked
3338 above.) */
3342 {
3343 r = (walk_subobject_offsets
3348 }
3349 }
3350 }
3352 /* Iterate through the fields of TYPE. */
3355 {
3356 tree field_offset;
3360 else
3361 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3365 f,
3367 offset,
3368 field_offset),
3369 offsets,
3370 max_offset,
3374 }
3375 }
3377 {
3380 tree index;
3382 /* Avoid recursing into objects that are not interesting. */
3387 /* Step through each of the elements in the array. */
3389 /* G++ 3.2 had an off-by-one error here. */
3394 {
3396 f,
3397 offset,
3398 offsets,
3399 max_offset,
3405 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3406 there's no point in iterating through the remaining
3407 elements of the array. */
3410 }
3411 }
3414 }
3416 /* Record all of the empty subobjects of TYPE (located at OFFSET) in
3417 OFFSETS. If VBASES_P is nonzero, virtual bases of TYPE are
3418 examined. */
3420 static void
3422 tree offset,
3423 splay_tree offsets,
3425 {
3428 }
3430 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3431 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3432 virtual bases of TYPE are examined. */
3434 static int
3436 tree offset,
3437 splay_tree offsets,
3439 {
3440 splay_tree_node max_node;
3442 /* Get the node in OFFSETS that indicates the maximum offset where
3443 an empty subobject is located. */
3445 /* If there aren't any empty subobjects, then there's no point in
3446 performing this check. */
3452 vbases_p);
3453 }
3455 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3456 non-static data member of the type indicated by RLI. BINFO is the
3457 binfo corresponding to the base subobject, OFFSETS maps offsets to
3458 types already located at those offsets. This function determines
3459 the position of the DECL. */
3461 static void
3463 tree decl,
3464 tree binfo,
3465 splay_tree offsets)
3466 {
3469 tree type;
3472 {
3473 /* For the purposes of determining layout conflicts, we want to
3474 use the class type of BINFO; TREE_TYPE (DECL) will be the
3475 CLASSTYPE_AS_BASE version, which does not contain entries for
3476 zero-sized bases. */
3479 }
3480 else
3481 {
3484 }
3486 /* Try to place the field. It may take more than one try if we have
3487 a hard time placing the field without putting two objects of the
3488 same type at the same address. */
3490 {
3493 /* Place this field. */
3497 /* We have to check to see whether or not there is already
3498 something of the same type at the offset we're about to use.
3499 For example, consider:
3501 struct S {};
3502 struct T : public S { int i; };
3503 struct U : public S, public T {};
3505 Here, we put S at offset zero in U. Then, we can't put T at
3506 offset zero -- its S component would be at the same address
3507 as the S we already allocated. So, we have to skip ahead.
3508 Since all data members, including those whose type is an
3509 empty class, have nonzero size, any overlap can happen only
3510 with a direct or indirect base-class -- it can't happen with
3511 a data member. */
3512 /* In a union, overlap is permitted; all members are placed at
3513 offset zero. */
3516 /* G++ 3.2 did not check for overlaps when placing a non-empty
3517 virtual base. */
3522 {
3523 /* Strip off the size allocated to this field. That puts us
3524 at the first place we could have put the field with
3525 proper alignment. */
3528 /* Bump up by the alignment required for the type. */
3529 rli->bitpos
3535 }
3536 else
3537 /* There was no conflict. We're done laying out this field. */
3539 }
3541 /* Now that we know where it will be placed, update its
3542 BINFO_OFFSET. */
3544 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3545 this point because their BINFO_OFFSET is copied from another
3546 hierarchy. Therefore, we may not need to add the entire
3547 OFFSET. */
3552 }
3554 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3556 static int
3558 tree offset,
3559 splay_tree offsets ATTRIBUTE_UNUSED)
3560 {
3562 }
3564 /* Layout the empty base BINFO. EOC indicates the byte currently just
3565 past the end of the class, and should be correctly aligned for a
3566 class of the type indicated by BINFO; OFFSETS gives the offsets of
3567 the empty bases allocated so far. T is the most derived
3568 type. Return nonzero iff we added it at the end. */
3570 static bool
3572 {
3573 tree alignment;
3577 /* This routine should only be used for empty classes. */
3582 {
3584 propagate_binfo_offsets
3590 }
3592 /* This is an empty base class. We first try to put it at offset
3593 zero. */
3596 offsets,
3598 {
3599 /* That didn't work. Now, we move forward from the next
3600 available spot in the class. */
3604 {
3607 offsets,
3609 /* We finally found a spot where there's no overlap. */
3612 /* There's overlap here, too. Bump along to the next spot. */
3614 }
3615 }
3617 }
3619 /* Layout the the base given by BINFO in the class indicated by RLI.
3620 *BASE_ALIGN is a running maximum of the alignments of
3621 any base class. OFFSETS gives the location of empty base
3622 subobjects. T is the most derived type. Return nonzero if the new
3623 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3624 *NEXT_FIELD, unless BINFO is for an empty base class.
3626 Returns the location at which the next field should be inserted. */
3631 {
3636 /* This error is now reported in xref_tag, thus giving better
3637 location information. */
3640 /* Place the base class. */
3642 {
3643 tree decl;
3645 /* The containing class is non-empty because it has a non-empty
3646 base class. */
3649 /* Create the FIELD_DECL. */
3659 /* Try to place the field. It may take more than one try if we
3660 have a hard time placing the field without putting two
3661 objects of the same type at the same address. */
3663 /* Add the new FIELD_DECL to the list of fields for T. */
3667 }
3668 else
3669 {
3670 tree eoc;
3673 /* On some platforms (ARM), even empty classes will not be
3674 byte-aligned. */
3678 /* A nearly-empty class "has no proper base class that is empty,
3679 not morally virtual, and at an offset other than zero." */
3681 {
3684 /* The check above (used in G++ 3.2) is insufficient because
3685 an empty class placed at offset zero might itself have an
3686 empty base at a nonzero offset. */
3688 empty_base_at_nonzero_offset_p,
3689 size_zero_node,
3693 {
3699 }
3700 }
3702 /* We do not create a FIELD_DECL for empty base classes because
3703 it might overlap some other field. We want to be able to
3704 create CONSTRUCTORs for the class by iterating over the
3705 FIELD_DECLs, and the back end does not handle overlapping
3706 FIELD_DECLs. */
3708 /* An empty virtual base causes a class to be non-empty
3709 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3710 here because that was already done when the virtual table
3711 pointer was created. */
3712 }
3714 /* Record the offsets of BINFO and its base subobjects. */
3717 offsets,
3721 }
3723 /* Layout all of the non-virtual base classes. Record empty
3724 subobjects in OFFSETS. T is the most derived type. Return nonzero
3725 if the type cannot be nearly empty. The fields created
3726 corresponding to the base classes will be inserted at
3727 *NEXT_FIELD. */
3729 static void
3732 {
3733 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3734 subobjects. */
3739 /* The primary base class is always allocated first. */
3744 /* Now allocate the rest of the bases. */
3746 {
3747 tree base_binfo;
3751 /* The primary base was already allocated above, so we don't
3752 need to allocate it again here. */
3756 /* Virtual bases are added at the end (a primary virtual base
3757 will have already been added). */
3763 }
3764 }
3766 /* Go through the TYPE_METHODS of T issuing any appropriate
3767 diagnostics, figuring out which methods override which other
3768 methods, and so forth. */
3770 static void
3772 {
3773 tree x;
3776 {
3777 /* If this was an evil function, don't keep it in class. */
3786 /* The name of the field is the original field name
3787 Save this in auxiliary field for later overloading. */
3789 {
3794 }
3795 }
3796 }
3798 /* FN is a constructor or destructor. Clone the declaration to create
3799 a specialized in-charge or not-in-charge version, as indicated by
3800 NAME. */
3802 static tree
3804 {
3805 tree parms;
3806 tree clone;
3808 /* Copy the function. */
3810 /* Remember where this function came from. */
3813 /* Reset the function name. */
3816 /* There's no pending inline data for this function. */
3819 /* And it hasn't yet been deferred. */
3822 /* The base-class destructor is not virtual. */
3824 {
3828 }
3830 /* If there was an in-charge parameter, drop it from the function
3831 type. */
3833 {
3834 tree basetype;
3835 tree parmtypes;
3836 tree exceptions;
3841 /* Skip the `this' parameter. */
3843 /* Skip the in-charge parameter. */
3845 /* And the VTT parm, in a complete [cd]tor. */
3849 /* If this is subobject constructor or destructor, add the vtt
3850 parameter. */
3854 parmtypes);
3857 exceptions);
3861 }
3863 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3864 aren't function parameters; those are the template parameters. */
3866 {
3868 /* Remove the in-charge parameter. */
3870 {
3874 }
3875 /* And the VTT parm, in a complete [cd]tor. */
3877 {
3880 else
3881 {
3885 }
3886 }
3889 {
3892 }
3893 }
3895 /* Create the RTL for this function. */
3899 /* Make it easy to find the CLONE given the FN. */
3903 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3905 {
3906 tree result;
3913 }
3918 }
3920 /* Produce declarations for all appropriate clones of FN. If
3921 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3922 CLASTYPE_METHOD_VEC as well. */
3924 void
3926 {
3927 tree clone;
3929 /* Avoid inappropriate cloning. */
3935 {
3936 /* For each constructor, we need two variants: an in-charge version
3937 and a not-in-charge version. */
3944 }
3945 else
3946 {
3949 /* For each destructor, we need three variants: an in-charge
3950 version, a not-in-charge version, and an in-charge deleting
3951 version. We clone the deleting version first because that
3952 means it will go second on the TYPE_METHODS list -- and that
3953 corresponds to the correct layout order in the virtual
3954 function table.
3956 For a non-virtual destructor, we do not build a deleting
3957 destructor. */
3959 {
3963 }
3970 }
3972 /* Note that this is an abstract function that is never emitted. */
3974 }
3976 /* DECL is an in charge constructor, which is being defined. This will
3977 have had an in class declaration, from whence clones were
3978 declared. An out-of-class definition can specify additional default
3979 arguments. As it is the clones that are involved in overload
3980 resolution, we must propagate the information from the DECL to its
3981 clones. */
3983 void
3985 {
3986 tree clone;
3990 {
3997 /* Skip the 'this' parameter. */
4013 {
4018 {
4019 /* A default parameter has been added. Adjust the
4020 clone's parameters. */
4023 tree type;
4028 {
4031 clone_parms);
4033 }
4036 clone_parms);
4043 }
4044 }
4046 }
4047 }
4049 /* For each of the constructors and destructors in T, create an
4050 in-charge and not-in-charge variant. */
4052 static void
4054 {
4055 tree fns;
4057 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4058 out now. */
4066 }
4068 /* Remove all zero-width bit-fields from T. */
4070 static void
4072 {
4077 {
4082 else
4084 }
4085 }
4087 /* Returns TRUE iff we need a cookie when dynamically allocating an
4088 array whose elements have the indicated class TYPE. */
4090 static bool
4092 {
4093 tree fns;
4098 /* If there's a non-trivial destructor, we need a cookie. In order
4099 to iterate through the array calling the destructor for each
4100 element, we'll have to know how many elements there are. */
4104 /* If the usual deallocation function is a two-argument whose second
4105 argument is of type `size_t', then we have to pass the size of
4106 the array to the deallocation function, so we will need to store
4107 a cookie. */
4111 /* If there are no `operator []' members, or the lookup is
4112 ambiguous, then we don't need a cookie. */
4115 /* Loop through all of the functions. */
4117 {
4118 tree fn;
4119 tree second_parm;
4121 /* Select the current function. */
4123 /* See if this function is a one-argument delete function. If
4124 it is, then it will be the usual deallocation function. */
4128 /* Otherwise, if we have a two-argument function and the second
4129 argument is `size_t', it will be the usual deallocation
4130 function -- unless there is one-argument function, too. */
4134 }
4137 }
4139 /* Check the validity of the bases and members declared in T. Add any
4140 implicitly-generated functions (like copy-constructors and
4141 assignment operators). Compute various flag bits (like
4142 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4143 level: i.e., independently of the ABI in use. */
4145 static void
4147 {
4148 /* Nonzero if we are not allowed to generate a default constructor
4149 for this case. */
4151 /* Nonzero if the implicitly generated copy constructor should take
4152 a non-const reference argument. */
4154 /* Nonzero if the the implicitly generated assignment operator
4155 should take a non-const reference argument. */
4157 tree access_decls;
4159 /* By default, we use const reference arguments and generate default
4160 constructors. */
4165 /* Check all the base-classes. */
4169 /* Check all the data member declarations. */
4175 /* Check all the method declarations. */
4178 /* A nearly-empty class has to be vptr-containing; a nearly empty
4179 class contains just a vptr. */
4183 /* Do some bookkeeping that will guide the generation of implicitly
4184 declared member functions. */
4202 /* Synthesize any needed methods. Note that methods will be synthesized
4203 for anonymous unions; grok_x_components undoes that. */
4205 cant_have_const_ctor,
4206 no_const_asn_ref);
4208 /* Create the in-charge and not-in-charge variants of constructors
4209 and destructors. */
4212 /* Process the using-declarations. */
4216 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4219 /* Figure out whether or not we will need a cookie when dynamically
4220 allocating an array of this type. */
4223 }
4225 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4226 accordingly. If a new vfield was created (because T doesn't have a
4227 primary base class), then the newly created field is returned. It
4228 is not added to the TYPE_FIELDS list; it is the caller's
4229 responsibility to do that. Accumulate declared virtual functions
4230 on VIRTUALS_P. */
4232 static tree
4234 {
4235 tree fn;
4237 /* Collect the virtual functions declared in T. */
4241 {
4249 }
4251 /* If we couldn't find an appropriate base class, create a new field
4252 here. Even if there weren't any new virtual functions, we might need a
4253 new virtual function table if we're supposed to include vptrs in
4254 all classes that need them. */
4256 {
4257 /* We build this decl with vtbl_ptr_type_node, which is a
4258 `vtable_entry_type*'. It might seem more precise to use
4259 `vtable_entry_type (*)[N]' where N is the number of firtual
4260 functions. However, that would require the vtable pointer in
4261 base classes to have a different type than the vtable pointer
4262 in derived classes. We could make that happen, but that
4263 still wouldn't solve all the problems. In particular, the
4264 type-based alias analysis code would decide that assignments
4265 to the base class vtable pointer can't alias assignments to
4266 the derived class vtable pointer, since they have different
4267 types. Thus, in a derived class destructor, where the base
4268 class constructor was inlined, we could generate bad code for
4269 setting up the vtable pointer.
4271 Therefore, we use one type for all vtable pointers. We still
4272 use a type-correct type; it's just doesn't indicate the array
4273 bounds. That's better than using `void*' or some such; it's
4274 cleaner, and it let's the alias analysis code know that these
4275 stores cannot alias stores to void*! */
4276 tree field;
4287 /* This class is non-empty. */
4291 /* If there were any baseclasses, they can't possibly be at
4292 offset zero any more, because that's where the vtable
4293 pointer is. So, converting to a base class is going to
4294 take work. */
4298 }
4301 }
4303 /* Fixup the inline function given by INFO now that the class is
4304 complete. */
4306 static void
4308 {
4310 {
4313 {
4316 }
4317 }
4318 }
4320 /* Fixup the inline methods and friends in TYPE now that TYPE is
4321 complete. */
4323 static void
4325 {
4329 {
4334 else
4336 }
4338 /* Do inline member functions. */
4342 /* Do friends. */
4344 method;
4348 }
4350 /* Add OFFSET to all base types of BINFO which is a base in the
4351 hierarchy dominated by T.
4353 OFFSET, which is a type offset, is number of bytes. */
4355 static void
4357 {
4359 tree primary_binfo;
4361 /* Update BINFO's offset. */
4366 offset));
4368 /* Find the primary base class. */
4371 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4372 downwards. */
4374 {
4375 tree base_binfo;
4377 /* On the first time through the loop, do the primary base.
4378 Because the primary base need not be an immediate base, we
4379 must handle the primary base specially. */
4381 {
4386 }
4387 else
4388 {
4390 /* Don't do the primary base twice. */
4393 }
4395 /* Skip virtual bases that aren't our canonical primary base. */
4401 }
4402 }
4404 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4405 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4406 empty subobjects of T. */
4408 static void
4410 {
4411 tree vbase;
4420 {
4421 /* In G++ 3.2, we incorrectly rounded the size before laying out
4422 the virtual bases. */
4424 #ifdef STRUCTURE_SIZE_BOUNDARY
4425 /* Packed structures don't need to have minimum size. */
4428 #endif
4432 }
4434 /* Find the last field. The artificial fields created for virtual
4435 bases will go after the last extant field to date. */
4440 /* Go through the virtual bases, allocating space for each virtual
4441 base that is not already a primary base class. These are
4442 allocated in inheritance graph order. */
4444 {
4449 {
4452 /* This virtual base is not a primary base of any class in the
4453 hierarchy, so we have to add space for it. */
4457 /* If the first virtual base might have been placed at a
4458 lower address, had we started from CLASSTYPE_SIZE, rather
4459 than TYPE_SIZE, issue a warning. There can be both false
4460 positives and false negatives from this warning in rare
4461 cases; to deal with all the possibilities would probably
4462 require performing both layout algorithms and comparing
4463 the results which is not particularly tractable. */
4465 && first_vbase
4466 && (tree_int_cst_lt
4470 bitsize_unit_node),
4472 warning ("offset of virtual base `%T' is not ABI-compliant and may change in a future version of GCC",
4473 basetype);
4476 }
4477 }
4478 }
4480 /* Returns the offset of the byte just past the end of the base class
4481 BINFO. */
4483 static tree
4485 {
4486 tree size;
4489 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4490 allocate some space for it. It cannot have virtual bases, so
4491 TYPE_SIZE_UNIT is fine. */
4493 else
4497 }
4499 /* Returns the offset of the byte just past the end of the base class
4500 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4501 only non-virtual bases are included. */
4503 static tree
4505 {
4507 tree binfo;
4508 tree offset;
4512 {
4523 }
4525 /* G++ 3.2 did not check indirect virtual bases. */
4528 binfo;
4530 {
4534 }
4537 }
4539 /* Warn about bases of T that are inaccessible because they are
4540 ambiguous. For example:
4542 struct S {};
4543 struct T : public S {};
4544 struct U : public S, public T {};
4546 Here, `(S*) new U' is not allowed because there are two `S'
4547 subobjects of U. */
4549 static void
4551 {
4553 tree vbases;
4554 tree basetype;
4556 /* Check direct bases. */
4558 {
4564 }
4566 /* Check for ambiguous virtual bases. */
4569 vbases;
4571 {
4577 }
4578 }
4580 /* Compare two INTEGER_CSTs K1 and K2. */
4582 static int
4584 {
4586 }
4588 /* Increase the size indicated in RLI to account for empty classes
4589 that are "off the end" of the class. */
4591 static void
4593 {
4594 tree eoc;
4595 tree rli_size;
4597 /* It might be the case that we grew the class to allocate a
4598 zero-sized base class. That won't be reflected in RLI, yet,
4599 because we are willing to overlay multiple bases at the same
4600 offset. However, now we need to make sure that RLI is big enough
4601 to reflect the entire class. */
4607 {
4609 /* In version 1 of the ABI, the size of a class that ends with
4610 a bitfield was not rounded up to a whole multiple of a
4611 byte. Because rli_size_unit_so_far returns only the number
4612 of fully allocated bytes, any extra bits were not included
4613 in the size. */
4615 else
4616 /* The size should have been rounded to a whole byte. */
4619 BITS_PER_UNIT)),
4621 rli->bitpos
4630 }
4631 }
4633 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4634 BINFO_OFFSETs for all of the base-classes. Position the vtable
4635 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4637 static void
4639 {
4640 tree non_static_data_members;
4641 tree field;
4642 tree vptr;
4643 record_layout_info rli;
4644 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4645 types that appear at that offset. */
4646 splay_tree empty_base_offsets;
4647 /* True if the last field layed out was a bit-field. */
4649 /* The location at which the next field should be inserted. */
4651 /* T, as a base class. */
4652 tree base_t;
4654 /* Keep track of the first non-static data member. */
4657 /* Start laying out the record. */
4660 /* If possible, we reuse the virtual function table pointer from one
4661 of our base classes. */
4664 /* Create a pointer to our virtual function table. */
4667 /* The vptr is always the first thing in the class. */
4669 {
4674 }
4675 else
4678 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4683 /* Layout the non-static data members. */
4685 {
4686 tree type;
4687 tree padding;
4689 /* We still pass things that aren't non-static data members to
4690 the back-end, in case it wants to do something with them. */
4692 {
4694 /* If the static data member has incomplete type, keep track
4695 of it so that it can be completed later. (The handling
4696 of pending statics in finish_record_layout is
4697 insufficient; consider:
4699 struct S1;
4700 struct S2 { static S1 s1; };
4702 At this point, finish_record_layout will be called, but
4703 S1 is still incomplete.) */
4707 }
4713 /* If this field is a bit-field whose width is greater than its
4714 type, then there are some special rules for allocating
4715 it. */
4718 {
4719 integer_type_kind itk;
4720 tree integer_type;
4722 /* We must allocate the bits as if suitably aligned for the
4723 longest integer type that fits in this many bits. type
4724 of the field. Then, we are supposed to use the left over
4725 bits as additional padding. */
4731 /* ITK now indicates a type that is too large for the
4732 field. We have to back up by one to find the largest
4733 type that fits. */
4736 /* Figure out how much additional padding is required. GCC
4737 3.2 always created a padding field, even if it had zero
4738 width. */
4741 {
4743 /* In a union, the padding field must have the full width
4744 of the bit-field; all fields start at offset zero. */
4746 else
4747 {
4750 "ABI-compliant and may change in a future "
4752 t);
4755 }
4756 }
4757 #ifdef PCC_BITFIELD_TYPE_MATTERS
4758 /* An unnamed bitfield does not normally affect the
4759 alignment of the containing class on a target where
4760 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4761 make any exceptions for unnamed bitfields when the
4762 bitfields are longer than their types. Therefore, we
4763 temporarily give the field a name. */
4765 {
4768 }
4769 #endif
4774 empty_base_offsets);
4777 /* Now that layout has been performed, set the size of the
4778 field to the size of its declared type; the rest of the
4779 field is effectively invisible. */
4781 /* We must also reset the DECL_MODE of the field. */
4786 /* Versions of G++ before G++ 3.4 did not reset the
4787 DECL_MODE. */
4790 }
4791 else
4793 empty_base_offsets);
4795 /* Remember the location of any empty classes in FIELD. */
4799 empty_base_offsets,
4802 /* If a bit-field does not immediately follow another bit-field,
4803 and yet it starts in the middle of a byte, we have failed to
4804 comply with the ABI. */
4807 && !last_field_was_bitfield
4810 bitsize_unit_node)))
4811 cp_warning_at ("offset of `%D' is not ABI-compliant and may change in a future version of GCC",
4812 field);
4814 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4815 offset of the field. */
4821 "classes to be placed at different locations in a "
4823 field);
4825 /* If we needed additional padding after this field, add it
4826 now. */
4828 {
4829 tree padding_field;
4832 NULL_TREE,
4833 char_type_node);
4839 NULL_TREE,
4840 empty_base_offsets);
4841 }
4844 }
4847 {
4848 /* Make sure that we are on a byte boundary so that the size of
4849 the class without virtual bases will always be a round number
4850 of bytes. */
4853 }
4855 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
4856 padding. */
4860 /* Delete all zero-width bit-fields from the list of fields. Now
4861 that the type is laid out they are no longer important. */
4864 /* Create the version of T used for virtual bases. We do not use
4865 make_aggr_type for this version; this is an artificial type. For
4866 a POD type, we just reuse T. */
4868 {
4871 /* Set the size and alignment for the new type. In G++ 3.2, all
4872 empty classes were considered to have size zero when used as
4873 base classes. */
4875 {
4881 t);
4882 }
4883 else
4884 {
4885 tree eoc;
4887 /* If the ABI version is not at least two, and the last
4888 field was a bit-field, RLI may not be on a byte
4889 boundary. In particular, rli_size_unit_so_far might
4890 indicate the last complete byte, while rli_size_so_far
4891 indicates the total number of bits used. Therefore,
4892 rli_size_so_far, rather than rli_size_unit_so_far, is
4893 used to compute TYPE_SIZE_UNIT. */
4901 eoc);
4908 }
4912 /* Copy the fields from T. */
4916 {
4927 }
4929 /* Record the base version of the type. */
4932 }
4933 else
4936 /* Every empty class contains an empty class. */
4940 /* Set the TYPE_DECL for this type to contain the right
4941 value for DECL_OFFSET, so that we can use it as part
4942 of a COMPONENT_REF for multiple inheritance. */
4945 /* Now fix up any virtual base class types that we left lying
4946 around. We must get these done before we try to lay out the
4947 virtual function table. As a side-effect, this will remove the
4948 base subobject fields. */
4951 /* Make sure that empty classes are reflected in RLI at this
4952 point. */
4955 /* Make sure not to create any structures with zero size. */
4960 /* Let the back-end lay out the type. */
4963 /* Warn about bases that can't be talked about due to ambiguity. */
4966 /* Clean up. */
4968 }
4970 /* Returns the virtual function with which the vtable for TYPE is
4971 emitted, or NULL_TREE if that heuristic is not applicable to TYPE. */
4973 static tree
4975 {
4976 tree method;
4979 || processing_template_decl
4992 }
4994 /* Perform processing required when the definition of T (a class type)
4995 is complete. */
4997 void
4999 {
5000 tree x;
5001 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5004 tree vfield;
5007 {
5010 else
5014 }
5016 /* If this type was previously laid out as a forward reference,
5017 make sure we lay it out again. */
5023 /* Make assumptions about the class; we'll reset the flags if
5024 necessary. */
5029 /* Do end-of-class semantic processing: checking the validity of the
5030 bases and members and add implicitly generated methods. */
5033 /* Find the key method. */
5035 {
5038 /* If a polymorphic class has no key method, we may emit the vtable
5039 in every translation unit where the class definition appears. */
5042 }
5044 /* Layout the class itself. */
5047 /* We use the base type for trivial assignments, and hence it
5048 needs a mode. */
5051 /* Make sure that we get our own copy of the vfield FIELD_DECL. */
5054 {
5060 /* The vtable better be at the start. */
5069 }
5070 else
5075 /* If we created a new vtbl pointer for this class, add it to the
5076 list. */
5081 /* If necessary, create the primary vtable for this class. */
5083 {
5084 /* We must enter these virtuals into the table. */
5088 /* Here we know enough to change the type of our virtual
5089 function table, but we will wait until later this function. */
5091 }
5094 {
5096 tree fn;
5105 /* Add entries for virtual functions introduced by this class. */
5108 /* Set DECL_VINDEX for all functions declared in this class. */
5110 fn;
5112 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5114 {
5118 /* A thunk. We should never be calling this entry directly
5119 from this vtable -- we'd use the entry for the non
5120 thunk base function. */
5124 }
5125 }
5129 /* Complete the rtl for any static member objects of the type we're
5130 working on. */
5136 /* Done with FIELDS...now decide whether to sort these for
5137 faster lookups later.
5139 We use a small number because most searches fail (succeeding
5140 ultimately as the search bores through the inheritance
5141 hierarchy), and we want this failure to occur quickly. */
5145 {
5151 field_decl_cmp);
5155 }
5158 {
5163 /* Mark the fact that constructor for T could affect anybody
5164 inheriting from T who wants to initialize vtables for
5165 VFIELDS's type. */
5168 }
5170 /* Make the rtl for any new vtables we have created, and unmark
5171 the base types we marked. */
5174 /* Build the VTT for T. */
5190 /* Finish debugging output for this type. */
5192 }
5194 /* When T was built up, the member declarations were added in reverse
5195 order. Rearrange them to declaration order. */
5197 void
5199 {
5200 tree next;
5201 tree prev;
5202 tree x;
5204 /* The following lists are all in reverse order. Put them in
5205 declaration order now. */
5209 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5210 reverse order, so we can't just use nreverse. */
5215 {
5219 }
5221 {
5225 }
5226 }
5228 tree
5230 {
5233 /* Now that we've got all the field declarations, reverse everything
5234 as necessary. */
5239 /* Nadger the current location so that diagnostics point to the start of
5240 the struct, not the end. */
5244 {
5248 }
5249 else
5258 else
5265 }
5266 \f
5267 /* Return the dynamic type of INSTANCE, if known.
5268 Used to determine whether the virtual function table is needed
5269 or not.
5271 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5272 of our knowledge of its type. *NONNULL should be initialized
5273 before this function is called. */
5275 static tree
5277 {
5279 {
5283 else
5288 /* This is a call to a constructor, hence it's never zero. */
5290 {
5294 }
5298 /* This is a call to a constructor, hence it's never zero. */
5300 {
5304 }
5315 /* Propagate nonnull. */
5335 {
5339 }
5340 /* fall through... */
5345 {
5349 }
5351 {
5355 /* if we're in a ctor or dtor, we know our type. */
5359 {
5363 }
5364 }
5366 {
5367 /* Reference variables should be references to objects. */
5371 /* DECL_VAR_MARKED_P is used to prevent recursion; a
5372 variable's initializer may refer to the variable
5373 itself. */
5377 {
5378 tree type;
5384 }
5385 }
5390 }
5391 }
5393 /* Return nonzero if the dynamic type of INSTANCE is known, and
5394 equivalent to the static type. We also handle the case where
5395 INSTANCE is really a pointer. Return negative if this is a
5396 ctor/dtor. There the dynamic type is known, but this might not be
5397 the most derived base of the original object, and hence virtual
5398 bases may not be layed out according to this type.
5400 Used to determine whether the virtual function table is needed
5401 or not.
5403 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5404 of our knowledge of its type. *NONNULL should be initialized
5405 before this function is called. */
5407 int
5409 {
5421 }
5423 \f
5424 void
5426 {
5429 current_class_stack
5436 }
5438 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5439 appropriate for TYPE.
5441 So that we may avoid calls to lookup_name, we cache the _TYPE
5442 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5444 For multiple inheritance, we perform a two-pass depth-first search
5445 of the type lattice. The first pass performs a pre-order search,
5446 marking types after the type has had its fields installed in
5447 the appropriate IDENTIFIER_CLASS_VALUE slot. The second pass merely
5448 unmarks the marked types. If a field or member function name
5449 appears in an ambiguous way, the IDENTIFIER_CLASS_VALUE of
5450 that name becomes `error_mark_node'. */
5452 void
5454 {
5457 /* Make sure there is enough room for the new entry on the stack. */
5459 {
5461 current_class_stack
5463 current_class_stack_size
5465 }
5467 /* Insert a new entry on the class stack. */
5472 current_class_depth++;
5474 /* Now set up the new type. */
5480 /* By default, things in classes are private, while things in
5481 structures or unions are public. */
5483 ? access_private_node
5490 {
5491 /* Forcibly remove any old class remnants. */
5493 }
5495 /* If we're about to enter a nested class, clear
5496 IDENTIFIER_CLASS_VALUE for the enclosing classes. */
5503 {
5506 {
5507 /* If we are entering the scope of a template declaration (not a
5508 specialization), we need to push all the using decls with
5509 dependent scope too. */
5510 tree fields;
5516 }
5517 }
5518 else
5519 {
5520 tree item;
5522 /* We are re-entering the same class we just left, so we don't
5523 have to search the whole inheritance matrix to find all the
5524 decls to bind again. Instead, we install the cached
5525 class_shadowed list, and walk through it binding names and
5526 setting up IDENTIFIER_TYPE_VALUEs. */
5529 {
5536 }
5538 }
5541 }
5543 /* When we exit a toplevel class scope, we save the
5544 IDENTIFIER_CLASS_VALUEs so that we can restore them quickly if we
5545 reenter the class. Here, we've entered some other class, so we
5546 must invalidate our cache. */
5548 void
5550 {
5551 tree t;
5553 /* The IDENTIFIER_CLASS_VALUEs are no longer valid. */
5559 }
5561 /* Get out of the current class scope. If we were in a class scope
5562 previously, that is the one popped to. */
5564 void
5566 {
5570 current_class_depth--;
5576 }
5578 /* Returns 1 if current_class_type is either T or a nested type of T.
5579 We start looking from 1 because entry 0 is from global scope, and has
5580 no type. */
5582 int
5584 {
5593 }
5595 /* If either current_class_type or one of its enclosing classes are derived
5596 from T, return the appropriate type. Used to determine how we found
5597 something via unqualified lookup. */
5599 tree
5601 {
5604 /* The bases of a dependent type are unknown. */
5619 }
5621 /* When entering a class scope, all enclosing class scopes' names with
5622 static meaning (static variables, static functions, types and
5623 enumerators) have to be visible. This recursive function calls
5624 pushclass for all enclosing class contexts until global or a local
5625 scope is reached. TYPE is the enclosed class. */
5627 void
5629 {
5630 tree context;
5632 /* A namespace might be passed in error cases, like A::B:C. */
5646 }
5648 /* Undoes a push_nested_class call. */
5650 void
5652 {
5658 }
5660 /* Returns the number of extern "LANG" blocks we are nested within. */
5662 int
5664 {
5666 }
5668 /* Set global variables CURRENT_LANG_NAME to appropriate value
5669 so that behavior of name-mangling machinery is correct. */
5671 void
5673 {
5677 {
5679 }
5681 {
5683 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5684 (See record_builtin_java_type in decl.c.) However, that causes
5685 incorrect debug entries if these types are actually used.
5686 So we re-enable debug output after extern "Java". */
5695 }
5697 {
5699 }
5700 else
5702 }
5704 /* Get out of the current language scope. */
5706 void
5708 {
5711 }
5712 \f
5713 /* Type instantiation routines. */
5715 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5716 matches the TARGET_TYPE. If there is no satisfactory match, return
5717 error_mark_node, and issue a error & warning messages under control
5718 of FLAGS. Permit pointers to member function if FLAGS permits. If
5719 TEMPLATE_ONLY, the name of the overloaded function was a
5720 template-id, and EXPLICIT_TARGS are the explicitly provided
5721 template arguments. */
5723 static tree
5725 tree overload,
5726 tsubst_flags_t flags,
5728 tree explicit_targs)
5729 {
5730 /* Here's what the standard says:
5732 [over.over]
5734 If the name is a function template, template argument deduction
5735 is done, and if the argument deduction succeeds, the deduced
5736 arguments are used to generate a single template function, which
5737 is added to the set of overloaded functions considered.
5739 Non-member functions and static member functions match targets of
5740 type "pointer-to-function" or "reference-to-function." Nonstatic
5741 member functions match targets of type "pointer-to-member
5742 function;" the function type of the pointer to member is used to
5743 select the member function from the set of overloaded member
5744 functions. If a nonstatic member function is selected, the
5745 reference to the overloaded function name is required to have the
5746 form of a pointer to member as described in 5.3.1.
5748 If more than one function is selected, any template functions in
5749 the set are eliminated if the set also contains a non-template
5750 function, and any given template function is eliminated if the
5751 set contains a second template function that is more specialized
5752 than the first according to the partial ordering rules 14.5.5.2.
5753 After such eliminations, if any, there shall remain exactly one
5754 selected function. */
5758 /* We store the matches in a TREE_LIST rooted here. The functions
5759 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5760 interoperability with most_specialized_instantiation. */
5762 tree fn;
5764 /* By the time we get here, we should be seeing only real
5765 pointer-to-member types, not the internal POINTER_TYPE to
5766 METHOD_TYPE representation. */
5773 /* Check that the TARGET_TYPE is reasonable. */
5777 /* This is OK, too. */
5780 {
5781 /* This is OK, too. This comes from a conversion to reference
5782 type. */
5785 }
5786 else
5787 {
5793 }
5795 /* If we can find a non-template function that matches, we can just
5796 use it. There's no point in generating template instantiations
5797 if we're just going to throw them out anyhow. But, of course, we
5798 can only do this when we don't *need* a template function. */
5800 {
5801 tree fns;
5804 {
5806 tree fntype;
5809 /* We're not looking for templates just yet. */
5814 /* We're looking for a non-static member, and this isn't
5815 one, or vice versa. */
5818 /* Ignore anticipated decls of undeclared builtins. */
5822 /* See if there's a match. */
5831 }
5832 }
5834 /* Now, if we've already got a match (or matches), there's no need
5835 to proceed to the template functions. But, if we don't have a
5836 match we need to look at them, too. */
5838 {
5839 tree target_fn_type;
5840 tree target_arg_types;
5841 tree target_ret_type;
5842 tree fns;
5845 target_fn_type
5847 else
5852 /* Never do unification on the 'this' parameter. */
5857 {
5859 tree instantiation;
5860 tree instantiation_type;
5861 tree targs;
5864 /* We're only looking for templates. */
5869 /* We're not looking for a non-static member, and this is
5870 one, or vice versa. */
5873 /* Try to do argument deduction. */
5878 /* Argument deduction failed. */
5881 /* Instantiate the template. */
5884 /* Instantiation failed. */
5887 /* See if there's a match. */
5890 instantiation_type =
5896 }
5898 /* Now, remove all but the most specialized of the matches. */
5900 {
5905 }
5906 }
5908 /* Now we should have exactly one function in MATCHES. */
5910 {
5911 /* There were *no* matches. */
5913 {
5916 target_type);
5918 /* print_candidates expects a chain with the functions in
5919 TREE_VALUE slots, so we cons one up here (we're losing anyway,
5920 so why be clever?). */
5923 matches);
5926 }
5928 }
5930 {
5931 /* There were too many matches. */
5934 {
5935 tree match;
5939 target_type);
5941 /* Since print_candidates expects the functions in the
5942 TREE_VALUE slot, we flip them here. */
5947 }
5950 }
5952 /* Good, exactly one match. Now, convert it to the correct type. */
5957 {
5965 {
5968 }
5969 }
5971 /* If we're doing overload resolution purely for the purpose of
5972 determining conversion sequences, we should not consider the
5973 function used. If this conversion sequence is selected, the
5974 function will be marked as used at this point. */
5980 else
5981 {
5982 /* The target must be a REFERENCE_TYPE. Above, build_unary_op
5983 will mark the function as addressed, but here we must do it
5984 explicitly. */
5988 }
5989 }
5991 /* This function will instantiate the type of the expression given in
5992 RHS to match the type of LHSTYPE. If errors exist, then return
5993 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
5994 we complain on errors. If we are not complaining, never modify rhs,
5995 as overload resolution wants to try many possible instantiations, in
5996 the hope that at least one will work.
5998 For non-recursive calls, LHSTYPE should be a function, pointer to
5999 function, or a pointer to member function. */
6001 tree
6003 {
6009 {
6013 }
6016 {
6022 /* Microsoft allows `A::f' to be resolved to a
6023 pointer-to-member. */
6024 ;
6025 else
6026 {
6031 }
6032 }
6037 /* We don't overwrite rhs if it is an overloaded function.
6038 Copying it would destroy the tree link. */
6042 /* This should really only be used when attempting to distinguish
6043 what sort of a pointer to function we have. For now, any
6044 arithmetic operation which is not supported on pointers
6045 is rejected as an error. */
6048 {
6059 {
6060 tree new_rhs;
6070 }
6078 {
6083 /* Do not lose object's side effects. */
6087 }
6094 /* This can happen if we are forming a pointer-to-member for a
6095 member template. */
6098 /* Fall through. */
6101 {
6105 return
6108 args);
6109 }
6113 return
6119 /* Now we should have a baselink. */
6125 /* This is too hard for now. */
6198 {
6202 }
6225 {
6230 }
6241 }
6242 }
6243 \f
6244 /* Return the name of the virtual function pointer field
6245 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6246 this may have to look back through base types to find the
6247 ultimate field name. (For single inheritance, these could
6248 all be the same name. Who knows for multiple inheritance). */
6250 static tree
6252 {
6266 }
6268 void
6270 {
6271 #ifdef GATHER_STATISTICS
6275 {
6280 }
6281 #endif
6282 }
6284 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6285 according to [class]:
6286 The class-name is also inserted
6287 into the scope of the class itself. For purposes of access checking,
6288 the inserted class name is treated as if it were a public member name. */
6290 void
6292 {
6295 tree saved_cas;
6309 }
6311 /* Returns 1 if TYPE contains only padding bytes. */
6313 int
6315 {
6322 /* In G++ 3.2, whether or not a class was empty was determined by
6323 looking at its size. */
6326 else
6328 }
6330 /* Returns true if TYPE contains an empty class. */
6332 static bool
6334 {
6338 {
6339 tree field;
6350 }
6354 }
6356 /* Find the enclosing class of the given NODE. NODE can be a *_DECL or
6357 a *_TYPE node. NODE can also be a local class. */
6359 tree
6361 {
6365 {
6367 {
6380 }
6381 }
6383 }
6385 /* Note that NAME was looked up while the current class was being
6386 defined and that the result of that lookup was DECL. */
6388 void
6390 {
6391 splay_tree names_used;
6393 /* If we're not defining a class, there's nothing to do. */
6397 /* If there's already a binding for this NAME, then we don't have
6398 anything to worry about. */
6410 }
6412 /* Note that NAME was declared (as DECL) in the current class. Check
6413 to see that the declaration is valid. */
6415 void
6417 {
6418 splay_tree names_used;
6419 splay_tree_node n;
6421 /* Look to see if we ever used this name. */
6422 names_used
6429 {
6430 /* [basic.scope.class]
6432 A name N used in a class S shall refer to the same declaration
6433 in its context and when re-evaluated in the completed scope of
6434 S. */
6439 }
6440 }
6442 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6443 Secondary vtables are merged with primary vtables; this function
6444 will return the VAR_DECL for the primary vtable. */
6446 tree
6448 {
6449 tree decl;
6453 {
6457 }
6461 }
6464 /* Returns the binfo for the primary base of BINFO. If the resulting
6465 BINFO is a virtual base, and it is inherited elsewhere in the
6466 hierarchy, then the returned binfo might not be the primary base of
6467 BINFO in the complete object. Check BINFO_PRIMARY_P or
6468 BINFO_LOST_PRIMARY_P to be sure. */
6470 tree
6472 {
6473 tree primary_base;
6474 tree result;
6482 }
6484 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6486 static int
6488 {
6492 }
6494 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6495 INDENT should be zero when called from the top level; it is
6496 incremented recursively. IGO indicates the next expected BINFO in
6497 inheritance graph ordering. */
6499 static tree
6502 tree binfo,
6503 tree igo,
6505 {
6507 tree base_binfos;
6514 {
6517 }
6532 {
6536 TFF_PLAIN_IDENTIFIER),
6538 }
6540 {
6543 }
6548 {
6552 {
6556 TFF_PLAIN_IDENTIFIER));
6557 }
6559 {
6563 TFF_PLAIN_IDENTIFIER));
6564 }
6566 {
6570 TFF_PLAIN_IDENTIFIER));
6571 }
6573 {
6577 TFF_PLAIN_IDENTIFIER));
6578 }
6582 }
6586 {
6591 {
6596 }
6597 }
6600 }
6602 /* Dump the BINFO hierarchy for T. */
6604 static void
6606 {
6618 }
6620 /* Debug interface to hierarchy dumping. */
6624 {
6626 }
6628 static void
6630 {
6635 {
6638 }
6639 }
6641 static void
6643 {
6644 tree inits;
6646 HOST_WIDE_INT elt;
6654 TFF_PLAIN_IDENTIFIER));
6661 }
6663 static void
6665 {
6673 {
6680 {
6684 }
6688 }
6691 }
6693 static void
6695 {
6703 {
6708 }
6711 }
6713 /* Dump a function or thunk and its thunkees. */
6715 static void
6717 {
6720 tree thunks;
6728 {
6738 else
6744 }
6748 }
6750 /* Dump the thunks for FN. */
6754 {
6756 }
6758 /* Virtual function table initialization. */
6760 /* Create all the necessary vtables for T and its base classes. */
6762 static void
6764 {
6765 tree list;
6766 tree vbase;
6768 /* We lay out the primary and secondary vtables in one contiguous
6769 vtable. The primary vtable is first, followed by the non-virtual
6770 secondary vtables in inheritance graph order. */
6775 /* Then come the virtual bases, also in inheritance graph order. */
6777 {
6781 }
6785 }
6787 /* Initialize the vtable for BINFO with the INITS. */
6789 static void
6791 {
6792 tree decl;
6798 }
6800 /* Initialize DECL (a declaration for a namespace-scope array) with
6801 the INITS. */
6803 static void
6805 {
6806 tree context;
6814 }
6816 /* Build the VTT (virtual table table) for T.
6817 A class requires a VTT if it has virtual bases.
6819 This holds
6820 1 - primary virtual pointer for complete object T
6821 2 - secondary VTTs for each direct non-virtual base of T which requires a
6822 VTT
6823 3 - secondary virtual pointers for each direct or indirect base of T which
6824 has virtual bases or is reachable via a virtual path from T.
6825 4 - secondary VTTs for each direct or indirect virtual base of T.
6827 Secondary VTTs look like complete object VTTs without part 4. */
6829 static void
6831 {
6832 tree inits;
6833 tree type;
6834 tree vtt;
6835 tree index;
6837 /* Build up the initializers for the VTT. */
6842 /* If we didn't need a VTT, we're done. */
6846 /* Figure out the type of the VTT. */
6850 /* Now, build the VTT object itself. */
6853 /* Add the VTT to the vtables list. */
6858 }
6860 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6861 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6862 and CHAIN the vtable pointer for this binfo after construction is
6863 complete. VALUE can also be another BINFO, in which case we recurse. */
6865 static tree
6867 {
6868 tree vt;
6871 {
6877 else
6879 }
6882 }
6884 /* Recursively build the VTT-initializer for BINFO (which is in the
6885 hierarchy dominated by T). INITS points to the end of the initializer
6886 list to date. INDEX is the VTT index where the next element will be
6887 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
6888 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
6889 for virtual bases of T. When it is not so, we build the constructor
6890 vtables for the BINFO-in-T variant. */
6894 {
6896 tree b;
6897 tree init;
6898 tree secondary_vptrs;
6901 /* We only need VTTs for subobjects with virtual bases. */
6905 /* We need to use a construction vtable if this is not the primary
6906 VTT. */
6908 {
6911 /* Record the offset in the VTT where this sub-VTT can be found. */
6913 }
6915 /* Add the address of the primary vtable for the complete object. */
6920 {
6923 }
6926 /* Recursively add the secondary VTTs for non-virtual bases. */
6928 {
6933 }
6935 /* Add secondary virtual pointers for all subobjects of BINFO with
6936 either virtual bases or reachable along a virtual path, except
6937 subobjects that are non-virtual primary bases. */
6944 dfs_build_secondary_vptr_vtt_inits,
6945 NULL,
6946 dfs_ctor_vtable_bases_queue_p,
6947 secondary_vptrs);
6950 secondary_vptrs);
6954 /* The secondary vptrs come back in reverse order. After we reverse
6955 them, and add the INITS, the last init will be the first element
6956 of the chain. */
6959 {
6963 }
6965 /* Add the secondary VTTs for virtual bases. */
6968 {
6973 }
6976 {
6982 dfs_ctor_vtable_bases_queue_p,
6983 data);
6984 }
6987 }
6989 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo
6990 for the base in most derived. DATA is a TREE_LIST who's
6991 TREE_CHAIN is the type of the base being
6992 constructed whilst this secondary vptr is live. The TREE_UNSIGNED
6993 flag of DATA indicates that this is a constructor vtable. The
6994 TREE_TOP_LEVEL flag indicates that this is the primary VTT. */
6996 static tree
6998 {
6999 tree l;
7000 tree t;
7001 tree init;
7002 tree index;
7011 /* We don't care about bases that don't have vtables. */
7015 /* We're only interested in proper subobjects of T. */
7019 /* We're not interested in non-virtual primary bases. */
7023 /* If BINFO has virtual bases or is reachable via a virtual path
7024 from T, it'll have a secondary vptr. */
7029 /* Record the index where this secondary vptr can be found. */
7032 {
7035 }
7039 /* Add the initializer for the secondary vptr itself. */
7041 {
7042 /* It's a primary virtual base, and this is not the construction
7043 vtable. Find the base this is primary of in the inheritance graph,
7044 and use that base's vtable now. */
7047 }
7052 }
7054 /* dfs_walk_real predicate for building vtables. DATA is a TREE_LIST,
7055 VTT_MARKED_BINFO_P indicates whether marked or unmarked bases
7056 should be walked. TREE_PURPOSE is the TREE_TYPE that dominates the
7057 hierarchy. */
7059 static tree
7062 {
7068 }
7070 /* Called from build_vtt_inits via dfs_walk. After building constructor
7071 vtables and generating the sub-vtt from them, we need to restore the
7072 BINFO_VTABLES that were scribbled on. DATA is a TREE_LIST whose
7073 TREE_VALUE is the TREE_TYPE of the base whose sub vtt was generated. */
7075 static tree
7077 {
7080 /* We don't care about bases that don't have vtables. */
7084 /* If we scribbled the construction vtable vptr into BINFO, clear it
7085 out now. */
7093 }
7095 /* Build the construction vtable group for BINFO which is in the
7096 hierarchy dominated by T. */
7098 static void
7100 {
7101 tree list;
7102 tree type;
7103 tree vtbl;
7104 tree inits;
7105 tree id;
7106 tree vbase;
7108 /* See if we've already created this construction vtable group. */
7114 /* Build a version of VTBL (with the wrong type) for use in
7115 constructing the addresses of secondary vtables in the
7116 construction vtable group. */
7122 /* Add the vtables for each of our virtual bases using the vbase in T
7123 binfo. */
7125 vbase;
7127 {
7128 tree b;
7135 }
7138 /* Figure out the type of the construction vtable. */
7143 /* Initialize the construction vtable. */
7147 }
7149 /* Add the vtbl initializers for BINFO (and its bases other than
7150 non-virtual primaries) to the list of INITS. BINFO is in the
7151 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7152 the constructor the vtbl inits should be accumulated for. (If this
7153 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7154 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7155 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7156 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7157 but are not necessarily the same in terms of layout. */
7159 static void
7161 tree orig_binfo,
7162 tree rtti_binfo,
7163 tree t,
7164 tree inits)
7165 {
7173 /* If it doesn't have a vptr, we don't do anything. */
7177 /* If we're building a construction vtable, we're not interested in
7178 subobjects that don't require construction vtables. */
7184 /* Build the initializers for the BINFO-in-T vtable. */
7190 /* Walk the BINFO and its bases. We walk in preorder so that as we
7191 initialize each vtable we can figure out at what offset the
7192 secondary vtable lies from the primary vtable. We can't use
7193 dfs_walk here because we need to iterate through bases of BINFO
7194 and RTTI_BINFO simultaneously. */
7196 {
7199 /* Skip virtual bases. */
7205 inits);
7206 }
7207 }
7209 /* Called from accumulate_vtbl_inits. Returns the initializers for
7210 the BINFO vtable. */
7212 static tree
7214 tree orig_binfo,
7215 tree rtti_binfo,
7216 tree t,
7217 tree l)
7218 {
7225 {
7226 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7227 primary virtual base. If it is not the same primary in
7228 the hierarchy of T, we'll need to generate a ctor vtable
7229 for it, to place at its location in T. If it is the same
7230 primary, we still need a VTT entry for the vtable, but it
7231 should point to the ctor vtable for the base it is a
7232 primary for within the sub-hierarchy of RTTI_BINFO.
7234 There are three possible cases:
7236 1) We are in the same place.
7237 2) We are a primary base within a lost primary virtual base of
7238 RTTI_BINFO.
7239 3) We are primary to something not a base of RTTI_BINFO. */
7244 /* First, look through the bases we are primary to for RTTI_BINFO
7245 or a virtual base. */
7247 {
7251 }
7252 /* If we run out of primary links, keep looking down our
7253 inheritance chain; we might be an indirect primary. */
7259 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7260 base B and it is a base of RTTI_BINFO, this is case 2. In
7261 either case, we share our vtable with LAST, i.e. the
7262 derived-most base within B of which we are a primary. */
7266 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7267 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7268 binfo_ctor_vtable after everything's been set up. */
7271 /* Otherwise, this is case 3 and we get our own. */
7272 }
7277 {
7278 tree index;
7281 /* Compute the initializer for this vtable. */
7285 /* Figure out the position to which the VPTR should point. */
7288 vtbl_ptr_type_node,
7289 vtbl);
7296 index);
7299 }
7302 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7303 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7304 straighten this out. */
7308 else
7309 /* For an ordinary vtable, set BINFO_VTABLE. */
7313 }
7315 /* Construct the initializer for BINFO's virtual function table. BINFO
7316 is part of the hierarchy dominated by T. If we're building a
7317 construction vtable, the ORIG_BINFO is the binfo we should use to
7318 find the actual function pointers to put in the vtable - but they
7319 can be overridden on the path to most-derived in the graph that
7320 ORIG_BINFO belongs. Otherwise,
7321 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7322 BINFO that should be indicated by the RTTI information in the
7323 vtable; it will be a base class of T, rather than T itself, if we
7324 are building a construction vtable.
7326 The value returned is a TREE_LIST suitable for wrapping in a
7327 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7328 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7329 number of non-function entries in the vtable.
7331 It might seem that this function should never be called with a
7332 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7333 base is always subsumed by a derived class vtable. However, when
7334 we are building construction vtables, we do build vtables for
7335 primary bases; we need these while the primary base is being
7336 constructed. */
7338 static tree
7340 tree orig_binfo,
7341 tree t,
7342 tree rtti_binfo,
7344 {
7346 tree vfun_inits;
7347 tree vbase;
7348 vtbl_init_data vid;
7350 /* Initialize VID. */
7359 /* The first vbase or vcall offset is at index -3 in the vtable. */
7362 /* Add entries to the vtable for RTTI. */
7365 /* Create an array for keeping track of the functions we've
7366 processed. When we see multiple functions with the same
7367 signature, we share the vcall offsets. */
7369 /* Add the vcall and vbase offset entries. */
7371 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7372 build_vbase_offset_vtbl_entries. */
7374 vbase;
7378 /* If the target requires padding between data entries, add that now. */
7380 {
7384 {
7391 null_pointer_node),
7392 add);
7394 }
7395 }
7400 /* Go through all the ordinary virtual functions, building up
7401 initializers. */
7404 {
7405 tree delta;
7406 tree vcall_index;
7413 {
7417 {
7420 }
7422 }
7424 /* If the only definition of this function signature along our
7425 primary base chain is from a lost primary, this vtable slot will
7426 never be used, so just zero it out. This is important to avoid
7427 requiring extra thunks which cannot be generated with the function.
7429 We first check this in update_vtable_entry_for_fn, so we handle
7430 restored primary bases properly; we also need to do it here so we
7431 zero out unused slots in ctor vtables, rather than filling themff
7432 with erroneous values (though harmless, apart from relocation
7433 costs). */
7435 {
7436 /* We found a defn before a lost primary; go ahead as normal. */
7440 /* The nearest definition is from a lost primary; clear the
7441 slot. */
7443 {
7446 }
7447 }
7450 {
7451 /* Pull the offset for `this', and the function to call, out of
7452 the list. */
7459 /* You can't call an abstract virtual function; it's abstract.
7460 So, we replace these functions with __pure_virtual. */
7464 {
7468 }
7469 /* Take the address of the function, considering it to be of an
7470 appropriate generic type. */
7472 /* The address of a function can't change. */
7474 }
7476 /* And add it to the chain of initializers. */
7478 {
7483 else
7485 {
7492 }
7493 }
7494 else
7496 }
7498 /* The initializers for virtual functions were built up in reverse
7499 order; straighten them out now. */
7502 /* The negative offset initializers are also in reverse order. */
7505 /* Chain the two together. */
7507 }
7509 /* Adds to vid->inits the initializers for the vbase and vcall
7510 offsets in BINFO, which is in the hierarchy dominated by T. */
7512 static void
7514 {
7515 tree b;
7517 /* If this is a derived class, we must first create entries
7518 corresponding to the primary base class. */
7523 /* Add the vbase entries for this base. */
7525 /* Add the vcall entries for this base. */
7527 }
7529 /* Returns the initializers for the vbase offset entries in the vtable
7530 for BINFO (which is part of the class hierarchy dominated by T), in
7531 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7532 where the next vbase offset will go. */
7534 static void
7536 {
7537 tree vbase;
7538 tree t;
7539 tree non_primary_binfo;
7541 /* If there are no virtual baseclasses, then there is nothing to
7542 do. */
7548 /* We might be a primary base class. Go up the inheritance hierarchy
7549 until we find the most derived class of which we are a primary base:
7550 it is the offset of that which we need to use. */
7553 {
7554 tree b;
7556 /* If we have reached a virtual base, then it must be a primary
7557 base (possibly multi-level) of vid->binfo, or we wouldn't
7558 have called build_vcall_and_vbase_vtbl_entries for it. But it
7559 might be a lost primary, so just skip down to vid->binfo. */
7561 {
7564 }
7570 }
7572 /* Go through the virtual bases, adding the offsets. */
7574 vbase;
7576 {
7577 tree b;
7578 tree delta;
7583 /* Find the instance of this virtual base in the complete
7584 object. */
7587 /* If we've already got an offset for this virtual base, we
7588 don't need another one. */
7593 /* Figure out where we can find this vbase offset. */
7602 {
7603 /* The vbase offset had better be the same. */
7607 }
7609 /* The next vbase will come at a more negative offset. */
7613 /* The initializer is the delta from BINFO to this virtual base.
7614 The vbase offsets go in reverse inheritance-graph order, and
7615 we are walking in inheritance graph order so these end up in
7616 the right order. */
7622 vtable_entry_type,
7623 delta)));
7625 }
7626 }
7628 /* Adds the initializers for the vcall offset entries in the vtable
7629 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7630 to VID->INITS. */
7632 static void
7634 {
7635 /* We only need these entries if this base is a virtual base. We
7636 compute the indices -- but do not add to the vtable -- when
7637 building the main vtable for a class. */
7639 {
7640 /* We need a vcall offset for each of the virtual functions in this
7641 vtable. For example:
7643 class A { virtual void f (); };
7644 class B1 : virtual public A { virtual void f (); };
7645 class B2 : virtual public A { virtual void f (); };
7646 class C: public B1, public B2 { virtual void f (); };
7648 A C object has a primary base of B1, which has a primary base of A. A
7649 C also has a secondary base of B2, which no longer has a primary base
7650 of A. So the B2-in-C construction vtable needs a secondary vtable for
7651 A, which will adjust the A* to a B2* to call f. We have no way of
7652 knowing what (or even whether) this offset will be when we define B2,
7653 so we store this "vcall offset" in the A sub-vtable and look it up in
7654 a "virtual thunk" for B2::f.
7656 We need entries for all the functions in our primary vtable and
7657 in our non-virtual bases' secondary vtables. */
7659 /* If we are just computing the vcall indices -- but do not need
7660 the actual entries -- not that. */
7663 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7665 }
7666 }
7668 /* Build vcall offsets, starting with those for BINFO. */
7670 static void
7672 {
7674 tree primary_binfo;
7676 /* Don't walk into virtual bases -- except, of course, for the
7677 virtual base for which we are building vcall offsets. Any
7678 primary virtual base will have already had its offsets generated
7679 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7683 /* If BINFO has a primary base, process it first. */
7688 /* Add BINFO itself to the list. */
7691 /* Scan the non-primary bases of BINFO. */
7693 {
7694 tree base_binfo;
7699 }
7700 }
7702 /* Called from build_vcall_offset_vtbl_entries_r. */
7704 static void
7706 {
7707 /* Make entries for the rest of the virtuals. */
7709 {
7710 tree orig_fn;
7712 /* The ABI requires that the methods be processed in declaration
7713 order. G++ 3.2 used the order in the vtable. */
7715 orig_fn;
7719 }
7720 else
7721 {
7722 tree derived_virtuals;
7723 tree base_virtuals;
7724 tree orig_virtuals;
7725 /* If BINFO is a primary base, the most derived class which has
7726 BINFO as a primary base; otherwise, just BINFO. */
7727 tree non_primary_binfo;
7729 /* We might be a primary base class. Go up the inheritance hierarchy
7730 until we find the most derived class of which we are a primary base:
7731 it is the BINFO_VIRTUALS there that we need to consider. */
7734 {
7735 tree b;
7737 /* If we have reached a virtual base, then it must be vid->vbase,
7738 because we ignore other virtual bases in
7739 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7740 base (possibly multi-level) of vid->binfo, or we wouldn't
7741 have called build_vcall_and_vbase_vtbl_entries for it. But it
7742 might be a lost primary, so just skip down to vid->binfo. */
7744 {
7749 }
7755 }
7758 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7759 where rtti_binfo is the most derived type. */
7760 non_primary_binfo
7766 base_virtuals;
7770 {
7771 tree orig_fn;
7773 /* Find the declaration that originally caused this function to
7774 be present in BINFO_TYPE (binfo). */
7777 /* When processing BINFO, we only want to generate vcall slots for
7778 function slots introduced in BINFO. So don't try to generate
7779 one if the function isn't even defined in BINFO. */
7784 }
7785 }
7786 }
7788 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7790 static void
7792 {
7794 tree vcall_offset;
7796 /* If there is already an entry for a function with the same
7797 signature as FN, then we do not need a second vcall offset.
7798 Check the list of functions already present in the derived
7799 class vtable. */
7801 {
7802 tree derived_entry;
7806 /* We only use one vcall offset for virtual destructors,
7807 even though there are two virtual table entries. */
7811 }
7813 /* If we are building these vcall offsets as part of building
7814 the vtable for the most derived class, remember the vcall
7815 offset. */
7821 /* The next vcall offset will be found at a more negative
7822 offset. */
7826 /* Keep track of this function. */
7830 {
7831 tree base;
7832 tree fn;
7834 /* Find the overriding function. */
7838 integer_zero_node);
7839 else
7840 {
7843 /* The vbase we're working on is a primary base of
7844 vid->binfo. But it might be a lost primary, so its
7845 BINFO_OFFSET might be wrong, so we just use the
7846 BINFO_OFFSET from vid->binfo. */
7850 vcall_offset));
7851 }
7852 /* Add the initializer to the vtable. */
7855 }
7856 }
7858 /* Return vtbl initializers for the RTTI entries corresponding to the
7859 BINFO's vtable. The RTTI entries should indicate the object given
7860 by VID->rtti_binfo. */
7862 static void
7864 {
7865 tree b;
7866 tree t;
7867 tree basetype;
7868 tree offset;
7869 tree decl;
7870 tree init;
7875 /* To find the complete object, we will first convert to our most
7876 primary base, and then add the offset in the vtbl to that value. */
7880 {
7881 tree primary_base;
7886 }
7889 /* The second entry is the address of the typeinfo object. */
7892 else
7895 /* Convert the declaration to a type that can be stored in the
7896 vtable. */
7901 /* Add the offset-to-top entry. It comes earlier in the vtable that
7902 the the typeinfo entry. Convert the offset to look like a
7903 function pointer, so that we can put it in the vtable. */
7907 }