| blob | c3e3c53afe689554442f9c47a745d98b85563494 |
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, 2007, 2008, 2009, 2010
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 3, 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 COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
24 /* 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;
64 /* Nonzero if this class is no longer open, because of a call to
65 push_to_top_level. */
70 {
71 /* The base for which we're building initializers. */
72 tree binfo;
73 /* The type of the most-derived type. */
74 tree derived;
75 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
76 unless ctor_vtbl_p is true. */
77 tree rtti_binfo;
78 /* The negative-index vtable initializers built up so far. These
79 are in order from least negative index to most negative index. */
81 /* The binfo for the virtual base for which we're building
82 vcall offset initializers. */
83 tree vbase;
84 /* The functions in vbase for which we have already provided vcall
85 offsets. */
87 /* The vtable index of the next vcall or vbase offset. */
88 tree index;
89 /* Nonzero if we are building the initializer for the primary
90 vtable. */
92 /* Nonzero if we are building the initializer for a construction
93 vtable. */
95 /* True when adding vcall offset entries to the vtable. False when
96 merely computing the indices. */
100 /* The type of a function passed to walk_subobject_offsets. */
103 /* The stack itself. This is a dynamically resized array. The
104 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
108 /* The size of the largest empty class seen in this translation unit. */
111 /* An array of all local classes present in this translation unit, in
112 declaration order. */
202 splay_tree_key k2);
211 /* Variables shared between class.c and call.c. */
213 #ifdef GATHER_STATISTICS
221 #endif
223 /* Convert to or from a base subobject. EXPR is an expression of type
224 `A' or `A*', an expression of type `B' or `B*' is returned. To
225 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
226 the B base instance within A. To convert base A to derived B, CODE
227 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
228 In this latter case, A must not be a morally virtual base of B.
229 NONNULL is true if EXPR is known to be non-NULL (this is only
230 needed when EXPR is of pointer type). CV qualifiers are preserved
231 from EXPR. */
233 tree
235 tree expr,
236 tree binfo,
238 {
241 tree probe;
242 tree offset;
243 tree target_type;
245 tree ptr_target_type;
255 {
261 }
273 /* Nothing to do. */
277 {
281 }
284 /* This must happen before the call to save_expr. */
286 else
293 /* Do we need to look in the vtable for the real offset? */
296 /* Don't bother with the calculations inside sizeof; they'll ICE if the
297 source type is incomplete and the pointer value doesn't matter. */
299 {
304 }
306 /* Do we need to check for a null pointer? */
308 {
309 /* If we know the conversion will not actually change the value
310 of EXPR, then we can avoid testing the expression for NULL.
311 We have to avoid generating a COMPONENT_REF for a base class
312 field, because other parts of the compiler know that such
313 expressions are always non-NULL. */
315 {
316 tree class_type;
317 /* TARGET_TYPE has been extracted from BINFO, and, is
318 therefore always cv-unqualified. Extract the
319 cv-qualifiers from EXPR so that the expression returned
320 matches the input. */
322 target_type
326 }
328 }
330 /* Protect against multiple evaluation if necessary. */
334 /* Now that we've saved expr, build the real null test. */
336 {
340 }
342 /* If this is a simple base reference, express it as a COMPONENT_REF. */
344 /* We don't build base fields for empty bases, and they aren't very
345 interesting to the optimizers anyway. */
347 {
354 }
357 {
358 /* Going via virtual base V_BINFO. We need the static offset
359 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
360 V_BINFO. That offset is an entry in D_BINFO's vtable. */
361 tree v_offset;
364 {
365 /* In a base member initializer, we cannot rely on the
366 vtable being set up. We have to indirect via the
367 vtt_parm. */
368 tree t;
374 tf_warning_or_error);
375 }
376 else
378 tf_warning_or_error),
385 v_offset);
397 /* Negative fixed_type_p means this is a constructor or destructor;
398 virtual base layout is fixed in in-charge [cd]tors, but not in
399 base [cd]tors. */
403 v_offset,
406 else
408 }
410 target_type = cp_build_qualified_type
419 {
424 }
425 else
431 out:
435 integer_zero_node));
438 }
440 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
441 Perform a derived-to-base conversion by recursively building up a
442 sequence of COMPONENT_REFs to the appropriate base fields. */
444 static tree
446 {
449 tree field;
452 {
453 tree temp;
457 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
458 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
459 an lvalue in the front end; only _DECLs and _REFs are lvalues
460 in the back end. */
466 }
468 /* Recurse. */
473 /* Is this the base field created by build_base_field? */
477 {
478 /* We don't use build_class_member_access_expr here, as that
479 has unnecessary checks, and more importantly results in
480 recursive calls to dfs_walk_once. */
488 /* Mark the expression const or volatile, as appropriate.
489 Even though we've dealt with the type above, we still have
490 to mark the expression itself. */
497 }
499 /* Didn't find the base field?!? */
501 }
503 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
504 type is a class type or a pointer to a class type. In the former
505 case, TYPE is also a class type; in the latter it is another
506 pointer type. If CHECK_ACCESS is true, an error message is emitted
507 if TYPE is inaccessible. If OBJECT has pointer type, the value is
508 assumed to be non-NULL. */
510 tree
512 tsubst_flags_t complain)
513 {
514 tree binfo;
515 tree object_type;
516 base_access access;
519 {
522 }
523 else
530 access,
531 NULL);
536 }
538 /* EXPR is an expression with unqualified class type. BASE is a base
539 binfo of that class type. Returns EXPR, converted to the BASE
540 type. This function assumes that EXPR is the most derived class;
541 therefore virtual bases can be found at their static offsets. */
543 tree
545 {
546 tree expr_type;
550 {
551 tree pointer_type;
555 /* We use fold_build2 and fold_convert below to simplify the trees
556 provided to the optimizers. It is not safe to call these functions
557 when processing a template because they do not handle C++-specific
558 trees. */
567 }
570 }
572 \f
573 tree
575 {
581 /* First, convert to the requested type. */
586 /* Second, the requested type may not be the owner of its own vptr.
587 If not, convert to the base class that owns it. We cannot use
588 convert_to_base here, because VCONTEXT may appear more than once
589 in the inheritance hierarchy of TYPE, and thus direct conversion
590 between the types may be ambiguous. Following the path back up
591 one step at a time via primary bases avoids the problem. */
595 {
598 }
601 }
603 /* Given an object INSTANCE, return an expression which yields the
604 vtable element corresponding to INDEX. There are many special
605 cases for INSTANCE which we take care of here, mainly to avoid
606 creating extra tree nodes when we don't have to. */
608 static tree
610 {
611 tree aref;
614 /* Try to figure out what a reference refers to, and
615 access its virtual function table directly. */
623 {
628 }
637 }
639 tree
641 {
645 }
647 /* Given a stable object pointer INSTANCE_PTR, return an expression which
648 yields a function pointer corresponding to vtable element INDEX. */
650 tree
652 {
653 tree aref;
656 tf_warning_or_error),
657 idx);
659 /* When using function descriptors, the address of the
660 vtable entry is treated as a function pointer. */
665 /* Remember this as a method reference, for later devirtualization. */
669 }
671 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
672 for the given TYPE. */
674 static tree
676 {
678 }
680 /* DECL is an entity associated with TYPE, like a virtual table or an
681 implicitly generated constructor. Determine whether or not DECL
682 should have external or internal linkage at the object file
683 level. This routine does not deal with COMDAT linkage and other
684 similar complexities; it simply sets TREE_PUBLIC if it possible for
685 entities in other translation units to contain copies of DECL, in
686 the abstract. */
688 void
690 {
691 /* If TYPE involves a local class in a function with internal
692 linkage, then DECL should have internal linkage too. Other local
693 classes have no linkage -- but if their containing functions
694 have external linkage, it makes sense for DECL to have external
695 linkage too. That will allow template definitions to be merged,
696 for example. */
698 {
701 }
702 else
704 }
706 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
707 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
708 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
710 static tree
712 {
713 tree decl;
716 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
717 now to avoid confusion in mangle_decl. */
726 /* At one time the vtable info was grabbed 2 words at a time. This
727 fails on sparc unless you have 8-byte alignment. (tiemann) */
731 /* The vtable has not been defined -- yet. */
735 /* Mark the VAR_DECL node representing the vtable itself as a
736 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
737 is rather important that such things be ignored because any
738 effort to actually generate DWARF for them will run into
739 trouble when/if we encounter code like:
741 #pragma interface
742 struct S { virtual void member (); };
744 because the artificial declaration of the vtable itself (as
745 manufactured by the g++ front end) will say that the vtable is
746 a static member of `S' but only *after* the debug output for
747 the definition of `S' has already been output. This causes
748 grief because the DWARF entry for the definition of the vtable
749 will try to refer back to an earlier *declaration* of the
750 vtable as a static member of `S' and there won't be one. We
751 might be able to arrange to have the "vtable static member"
752 attached to the member list for `S' before the debug info for
753 `S' get written (which would solve the problem) but that would
754 require more intrusive changes to the g++ front end. */
758 }
760 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
761 or even complete. If this does not exist, create it. If COMPLETE is
762 nonzero, then complete the definition of it -- that will render it
763 impossible to actually build the vtable, but is useful to get at those
764 which are known to exist in the runtime. */
766 tree
768 {
769 tree decl;
778 {
781 }
784 }
786 /* Build the primary virtual function table for TYPE. If BINFO is
787 non-NULL, build the vtable starting with the initial approximation
788 that it is the same as the one which is the head of the association
789 list. Returns a nonzero value if a new vtable is actually
790 created. */
792 static int
794 {
795 tree decl;
796 tree virtuals;
801 {
803 /* We have already created a vtable for this base, so there's
804 no need to do it again. */
811 }
812 else
813 {
816 }
818 #ifdef GATHER_STATISTICS
821 #endif
823 /* Initialize the association list for this type, based
824 on our first approximation. */
829 }
831 /* Give BINFO a new virtual function table which is initialized
832 with a skeleton-copy of its original initialization. The only
833 entry that changes is the `delta' entry, so we can really
834 share a lot of structure.
836 FOR_TYPE is the most derived type which caused this table to
837 be needed.
839 Returns nonzero if we haven't met BINFO before.
841 The order in which vtables are built (by calling this function) for
842 an object must remain the same, otherwise a binary incompatibility
843 can result. */
845 static int
847 {
849 /* We already created a vtable for this base. There's no need to
850 do it again. */
853 /* Remember that we've created a vtable for this BINFO, so that we
854 don't try to do so again. */
857 /* Make fresh virtual list, so we can smash it later. */
860 /* Secondary vtables are laid out as part of the same structure as
861 the primary vtable. */
864 }
866 /* Create a new vtable for BINFO which is the hierarchy dominated by
867 T. Return nonzero if we actually created a new vtable. */
869 static int
871 {
873 /* In this case, it is *type*'s vtable we are modifying. We start
874 with the approximation that its vtable is that of the
875 immediate base class. */
877 else
878 /* This is our very own copy of `basetype' to play with. Later,
879 we will fill in all the virtual functions that override the
880 virtual functions in these base classes which are not defined
881 by the current type. */
883 }
885 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
886 (which is in the hierarchy dominated by T) list FNDECL as its
887 BV_FN. DELTA is the required constant adjustment from the `this'
888 pointer where the vtable entry appears to the `this' required when
889 the function is actually called. */
891 static void
893 tree binfo,
894 tree fndecl,
895 tree delta,
897 {
898 tree v;
904 {
905 /* We need a new vtable for BINFO. */
907 {
908 /* If we really did make a new vtable, we also made a copy
909 of the BINFO_VIRTUALS list. Now, we have to find the
910 corresponding entry in that list. */
915 }
920 }
921 }
923 \f
924 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
925 the USING_DECL naming METHOD. Returns true if the method could be
926 added to the method vec. */
928 bool
930 {
932 tree overload;
938 tree current_fns;
939 tree fns;
952 {
953 /* Make a new method vector. We start with 8 entries. We must
954 allocate at least two (for constructors and destructors), and
955 we're going to end up with an assignment operator at some
956 point as well. */
958 /* Create slots for constructors and destructors. */
962 }
964 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
967 /* Constructors and destructors go in special slots. */
971 {
975 {
981 type);
982 }
983 }
984 else
985 {
986 tree m;
989 /* See if we already have an entry with this name. */
993 {
996 {
1001 }
1005 {
1008 }
1013 }
1014 }
1017 /* Check to see if we've already got this method. */
1019 {
1021 tree fn_type;
1022 tree method_type;
1023 tree parms1;
1024 tree parms2;
1029 /* [over.load] Member function declarations with the
1030 same name and the same parameter types cannot be
1031 overloaded if any of them is a static member
1032 function declaration.
1034 [namespace.udecl] When a using-declaration brings names
1035 from a base class into a derived class scope, member
1036 functions in the derived class override and/or hide member
1037 functions with the same name and parameter types in a base
1038 class (rather than conflicting). */
1044 /* Compare the quals on the 'this' parm. Don't compare
1045 the whole types, as used functions are treated as
1046 coming from the using class in overload resolution. */
1055 /* For templates, the return type and template parameters
1056 must be identical. */
1073 {
1075 {
1077 /* Defer to the local function. */
1081 else
1083 using_decl);
1084 }
1085 else
1086 {
1089 }
1091 /* We don't call duplicate_decls here to merge the
1092 declarations because that will confuse things if the
1093 methods have inline definitions. In particular, we
1094 will crash while processing the definitions. */
1096 }
1097 }
1099 /* A class should never have more than one destructor. */
1103 /* Add the new binding. */
1112 {
1115 /* We only expect to add few methods in the COMPLETE_P case, so
1116 just make room for one more method in that case. */
1119 else
1125 else
1127 }
1128 else
1129 /* Replace the current slot. */
1132 }
1134 /* Subroutines of finish_struct. */
1136 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1137 legit, otherwise return 0. */
1139 static int
1141 {
1142 tree elem;
1151 {
1153 {
1157 else
1160 }
1161 else
1162 {
1163 /* They're changing the access to the same thing they changed
1164 it to before. That's OK. */
1165 ;
1166 }
1167 }
1168 else
1169 {
1173 }
1175 }
1177 /* Process the USING_DECL, which is a member of T. */
1179 static void
1181 {
1184 tree access
1189 tree old_value;
1195 {
1201 else
1203 }
1211 ;
1213 {
1215 /* It's OK to use functions from a base when there are functions with
1217 else
1218 {
1223 }
1224 }
1226 {
1230 }
1232 /* Make type T see field decl FDECL with access ACCESS. */
1235 {
1238 }
1239 else
1241 }
1242 \f
1243 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1244 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1245 properties of the bases. */
1247 static void
1251 {
1254 tree base_binfo;
1255 tree binfo;
1267 {
1272 /* If any base class is non-literal, so is the derived class. */
1276 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1277 here because the case of virtual functions but non-virtual
1278 dtor is handled in finish_struct_1. */
1283 /* If the base class doesn't have copy constructors or
1284 assignment operators that take const references, then the
1285 derived class cannot have such a member automatically
1286 generated. */
1295 /* A virtual base does not effect nearly emptiness. */
1296 ;
1298 {
1300 /* And if there is more than one nearly empty base, then the
1301 derived class is not nearly empty either. */
1303 else
1304 /* Remember we've seen one. */
1306 }
1308 /* If the base class is not empty or nearly empty, then this
1309 class cannot be nearly empty. */
1312 /* A lot of properties from the bases also apply to the derived
1313 class. */
1331 /* A standard-layout class is a class that:
1332 ...
1333 * has no non-standard-layout base classes, */
1336 {
1337 tree basefield;
1338 /* ...has no base classes of the same type as the first non-static
1339 data member... */
1341 && (same_type_ignoring_top_level_qualifiers_p
1344 else
1345 /* ...either has no non-static data members in the most-derived
1346 class and at most one base class with non-static data
1347 members, or has no base classes with non-static data
1348 members */
1352 {
1355 else
1358 }
1359 }
1360 }
1361 }
1363 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1364 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1365 that have had a nearly-empty virtual primary base stolen by some
1366 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1367 T. */
1369 static void
1371 {
1375 tree base_binfo;
1377 /* Determine the primary bases of our bases. */
1380 {
1383 /* See if we're the non-virtual primary of our inheritance
1384 chain. */
1386 {
1393 /* We are the primary binfo. */
1395 }
1396 /* Determine if we have a virtual primary base, and mark it so.
1397 */
1399 {
1403 /* Someone already claimed this base. */
1405 else
1406 {
1407 tree delta;
1412 /* A virtual binfo might have been copied from within
1413 another hierarchy. As we're about to use it as a
1414 primary base, make sure the offsets match. */
1422 }
1423 }
1424 }
1426 /* First look for a dynamic direct non-virtual base. */
1428 {
1432 {
1435 }
1436 }
1438 /* A "nearly-empty" virtual base class can be the primary base
1439 class, if no non-virtual polymorphic base can be found. Look for
1440 a nearly-empty virtual dynamic base that is not already a primary
1441 base of something in the hierarchy. If there is no such base,
1442 just pick the first nearly-empty virtual base. */
1448 {
1450 {
1451 /* Found one that is not primary. */
1454 }
1456 /* Remember the first candidate. */
1458 }
1460 found:
1461 /* If we've got a primary base, use it. */
1463 {
1468 /* We are stealing a primary base. */
1472 {
1473 tree delta;
1476 /* A virtual binfo might have been copied from within
1477 another hierarchy. As we're about to use it as a primary
1478 base, make sure the offsets match. */
1483 }
1490 }
1491 }
1493 /* Update the variant types of T. */
1495 void
1497 {
1498 tree variants;
1504 variants;
1506 {
1507 /* These fields are in the _TYPE part of the node, not in
1508 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1518 /* Copy whatever these are holding today. */
1522 }
1523 }
1525 /* Early variant fixups: we apply attributes at the beginning of the class
1526 definition, and we need to fix up any variants that have already been
1527 made via elaborated-type-specifier so that check_qualified_type works. */
1529 void
1531 {
1532 tree variants;
1538 variants;
1540 {
1541 /* These are the two fields that check_qualified_type looks at and
1542 are affected by attributes. */
1545 }
1546 }
1547 \f
1548 /* Set memoizing fields and bits of T (and its variants) for later
1549 use. */
1551 static void
1553 {
1554 /* Fix up variants (if any). */
1558 /* For a class w/o baseclasses, 'finish_struct' has set
1559 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1560 Similarly for a class whose base classes do not have vtables.
1561 When neither of these is true, we might have removed abstract
1562 virtuals (by providing a definition), added some (by declaring
1563 new ones), or redeclared ones from a base class. We need to
1564 recalculate what's really an abstract virtual at this point (by
1565 looking in the vtables). */
1568 /* If this type has a copy constructor or a destructor, force its
1569 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1570 nonzero. This will cause it to be passed by invisible reference
1571 and prevent it from being returned in a register. */
1574 {
1575 tree variants;
1578 {
1581 }
1582 }
1583 }
1585 /* Issue warnings about T having private constructors, but no friends,
1586 and so forth.
1588 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1589 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1590 non-private static member functions. */
1592 static void
1594 {
1597 tree fn;
1600 /* If the class has friends, those entities might create and
1601 access instances, so we should not warn. */
1604 /* We will have warned when the template was declared; there's
1605 no need to warn on every instantiation. */
1607 /* There's no reason to even consider warning about this
1608 class. */
1611 /* We only issue one warning, if more than one applies, because
1612 otherwise, on code like:
1614 class A {
1615 // Oops - forgot `public:'
1616 A();
1617 A(const A&);
1618 ~A();
1619 };
1621 we warn several times about essentially the same problem. */
1623 /* Check to see if all (non-constructor, non-destructor) member
1624 functions are private. (Since there are no friends or
1625 non-private statics, we can't ever call any of the private member
1626 functions.) */
1628 /* We're not interested in compiler-generated methods; they don't
1629 provide any way to call private members. */
1631 {
1633 {
1635 /* A non-private static member function is just like a
1636 friend; it can create and invoke private member
1637 functions, and be accessed without a class
1638 instance. */
1642 /* Keep searching for a static member function. */
1643 }
1646 }
1649 {
1650 /* There are no non-private methods, and there's at least one
1651 private member function that isn't a constructor or
1652 destructor. (If all the private members are
1653 constructors/destructors we want to use the code below that
1654 issues error messages specifically referring to
1655 constructors/destructors.) */
1661 {
1664 }
1666 {
1670 }
1671 }
1673 /* Even if some of the member functions are non-private, the class
1674 won't be useful for much if all the constructors or destructors
1675 are private: such an object can never be created or destroyed. */
1678 {
1681 t);
1683 }
1685 /* Warn about classes that have private constructors and no friends. */
1687 /* Implicitly generated constructors are always public. */
1690 {
1693 /* If a non-template class does not define a copy
1694 constructor, one is defined for it, enabling it to avoid
1695 this warning. For a template class, this does not
1696 happen, and so we would normally get a warning on:
1698 template <class T> class C { private: C(); };
1700 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1701 complete non-template or fully instantiated classes have this
1702 flag set. */
1705 else
1707 {
1709 /* Ideally, we wouldn't count copy constructors (or, in
1710 fact, any constructor that takes an argument of the
1711 class type as a parameter) because such things cannot
1712 be used to construct an instance of the class unless
1713 you already have one. But, for now at least, we're
1714 more generous. */
1716 {
1719 }
1720 }
1723 {
1726 t);
1728 }
1729 }
1730 }
1733 gt_pointer_operator new_value;
1737 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1739 static int
1741 {
1754 }
1756 /* This routine compares two fields like method_name_cmp but using the
1757 pointer operator in resort_field_decl_data. */
1759 static int
1761 {
1770 {
1777 }
1779 }
1781 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1783 void
1786 gt_pointer_operator new_value,
1788 {
1792 tree fn;
1794 /* The type conversion ops have to live at the front of the vec, so we
1795 can't sort them. */
1803 {
1807 resort_method_name_cmp);
1808 }
1809 }
1811 /* Warn about duplicate methods in fn_fields.
1813 Sort methods that are not special (i.e., constructors, destructors,
1814 and type conversion operators) so that we can find them faster in
1815 search. */
1817 static void
1819 {
1820 tree fn_fields;
1830 /* Clear DECL_IN_AGGR_P for all functions. */
1835 /* Issue warnings about private constructors and such. If there are
1836 no methods, then some public defaults are generated. */
1839 /* The type conversion ops have to live at the front of the vec, so we
1840 can't sort them. */
1849 }
1851 /* Make BINFO's vtable have N entries, including RTTI entries,
1852 vbase and vcall offsets, etc. Set its type and call the back end
1853 to lay it out. */
1855 static void
1857 {
1858 tree atype;
1859 tree vtable;
1865 /* We may have to grow the vtable. */
1868 {
1872 }
1873 }
1875 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1876 have the same signature. */
1878 int
1880 {
1881 /* One destructor overrides another if they are the same kind of
1882 destructor. */
1886 /* But a non-destructor never overrides a destructor, nor vice
1887 versa, nor do different kinds of destructors override
1888 one-another. For example, a complete object destructor does not
1889 override a deleting destructor. */
1898 {
1906 }
1908 }
1910 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1911 subobject. */
1913 static bool
1915 {
1916 tree probe;
1919 {
1923 /* If we meet a virtual base, we can't follow the inheritance
1924 any more. See if the complete type of DERIVED contains
1925 such a virtual base. */
1928 }
1930 }
1933 /* The function for which we are trying to find a final overrider. */
1934 tree fn;
1935 /* The base class in which the function was declared. */
1936 tree declaring_base;
1937 /* The candidate overriders. */
1938 tree candidates;
1939 /* Path to most derived. */
1943 /* Add the overrider along the current path to FFOD->CANDIDATES.
1944 Returns true if an overrider was found; false otherwise. */
1946 static bool
1950 {
1951 tree method;
1953 /* If BINFO is not the most derived type, try a more derived class.
1954 A definition there will overrider a definition here. */
1956 {
1957 depth--;
1961 }
1965 {
1968 /* Remove any candidates overridden by this new function. */
1970 {
1971 /* If *CANDIDATE overrides METHOD, then METHOD
1972 cannot override anything else on the list. */
1975 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1978 else
1980 }
1982 /* Add the new function. */
1985 }
1988 }
1990 /* Called from find_final_overrider via dfs_walk. */
1992 static tree
1994 {
2002 }
2004 static tree
2006 {
2011 }
2013 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2014 FN and whose TREE_VALUE is the binfo for the base where the
2015 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2016 DERIVED) is the base object in which FN is declared. */
2018 static tree
2020 {
2021 find_final_overrider_data ffod;
2023 /* Getting this right is a little tricky. This is valid:
2025 struct S { virtual void f (); };
2026 struct T { virtual void f (); };
2027 struct U : public S, public T { };
2029 even though calling `f' in `U' is ambiguous. But,
2031 struct R { virtual void f(); };
2032 struct S : virtual public R { virtual void f (); };
2033 struct T : virtual public R { virtual void f (); };
2034 struct U : public S, public T { };
2036 is not -- there's no way to decide whether to put `S::f' or
2037 `T::f' in the vtable for `R'.
2039 The solution is to look at all paths to BINFO. If we find
2040 different overriders along any two, then there is a problem. */
2044 /* Determine the depth of the hierarchy. */
2055 /* If there was no winner, issue an error message. */
2060 }
2062 /* Return the index of the vcall offset for FN when TYPE is used as a
2063 virtual base. */
2065 static tree
2067 {
2069 tree_pair_p p;
2077 /* There should always be an appropriate index. */
2079 }
2081 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2082 dominated by T. FN is the old function; VIRTUALS points to the
2083 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2084 of that entry in the list. */
2086 static void
2089 {
2090 tree b;
2091 tree overrider;
2092 tree delta;
2093 tree virtual_base;
2094 tree first_defn;
2100 /* Find the nearest primary base (possibly binfo itself) which defines
2101 this function; this is the class the caller will convert to when
2102 calling FN through BINFO. */
2104 {
2109 /* The nearest definition is from a lost primary. */
2112 }
2115 /* Find the final overrider. */
2118 {
2121 }
2124 /* Check for adjusting covariant return types. */
2132 /* If the overrider is invalid, don't even try. */
2134 {
2135 /* If FN is a covariant thunk, we must figure out the adjustment
2136 to the final base FN was converting to. As OVERRIDER_TARGET might
2137 also be converting to the return type of FN, we have to
2138 combine the two conversions here. */
2145 {
2149 }
2150 else
2154 /* Find the equivalent binfo within the return type of the
2155 overriding function. We will want the vbase offset from
2156 there. */
2158 over_return);
2161 {
2162 /* There was no existing virtual thunk (which takes
2163 precedence). So find the binfo of the base function's
2164 return type within the overriding function's return type.
2165 We cannot call lookup base here, because we're inside a
2166 dfs_walk, and will therefore clobber the BINFO_MARKED
2167 flags. Fortunately we know the covariancy is valid (it
2168 has already been checked), so we can just iterate along
2169 the binfos, which have been chained in inheritance graph
2170 order. Of course it is lame that we have to repeat the
2171 search here anyway -- we should really be caching pieces
2172 of the vtable and avoiding this repeated work. */
2175 /* Find the base binfo within the overriding function's
2176 return type. We will always find a thunk_binfo, except
2177 when the covariancy is invalid (which we will have
2178 already diagnosed). */
2181 thunk_binfo;
2187 /* See if virtual inheritance is involved. */
2189 virtual_offset;
2196 {
2200 {
2201 /* We convert via virtual base. Adjust the fixed
2202 offset to be from there. */
2203 offset =
2207 }
2209 /* There was an existing fixed offset, this must be
2210 from the base just converted to, and the base the
2211 FN was thunking to. */
2213 else
2215 }
2216 }
2219 /* Replace the overriding function with a covariant thunk. We
2220 will emit the overriding function in its own slot as
2221 well. */
2224 }
2225 else
2229 /* If we need a covariant thunk, then we may need to adjust first_defn.
2230 The ABI specifies that the thunks emitted with a function are
2231 determined by which bases the function overrides, so we need to be
2232 sure that we're using a thunk for some overridden base; even if we
2233 know that the necessary this adjustment is zero, there may not be an
2234 appropriate zero-this-adjusment thunk for us to use since thunks for
2235 overriding virtual bases always use the vcall offset.
2237 Furthermore, just choosing any base that overrides this function isn't
2238 quite right, as this slot won't be used for calls through a type that
2239 puts a covariant thunk here. Calling the function through such a type
2240 will use a different slot, and that slot is the one that determines
2241 the thunk emitted for that base.
2243 So, keep looking until we find the base that we're really overriding
2244 in this slot: the nearest primary base that doesn't use a covariant
2245 thunk in this slot. */
2247 {
2249 /* We already know that the overrider needs a covariant thunk. */
2252 {
2259 }
2261 }
2263 /* Assume that we will produce a thunk that convert all the way to
2264 the final overrider, and not to an intermediate virtual base. */
2267 /* See if we can convert to an intermediate virtual base first, and then
2268 use the vcall offset located there to finish the conversion. */
2270 {
2271 /* If we find the final overrider, then we can stop
2272 walking. */
2277 /* If we find a virtual base, and we haven't yet found the
2278 overrider, then there is a virtual base between the
2279 declaring base (first_defn) and the final overrider. */
2281 {
2284 }
2285 }
2287 /* Compute the constant adjustment to the `this' pointer. The
2288 `this' pointer, when this function is called, will point at BINFO
2289 (or one of its primary bases, which are at the same offset). */
2291 /* The `this' pointer needs to be adjusted from the declaration to
2292 the nearest virtual base. */
2297 /* If the nearest definition is in a lost primary, we don't need an
2298 entry in our vtable. Except possibly in a constructor vtable,
2299 if we happen to get our primary back. In that case, the offset
2300 will be zero, as it will be a primary base. */
2302 else
2303 /* The `this' pointer needs to be adjusted from pointing to
2304 BINFO to pointing at the base where the final overrider
2305 appears. */
2316 else
2321 }
2323 /* Called from modify_all_vtables via dfs_walk. */
2325 static tree
2327 {
2329 tree virtuals;
2330 tree old_virtuals;
2334 /* A base without a vtable needs no modification, and its bases
2335 are uninteresting. */
2340 /* Don't do the primary vtable, if it's new. */
2344 /* There's no need to modify the vtable for a non-virtual primary
2345 base; we're not going to use that vtable anyhow. We do still
2346 need to do this for virtual primary bases, as they could become
2347 non-primary in a construction vtable. */
2352 /* Now, go through each of the virtual functions in the virtual
2353 function table for BINFO. Find the final overrider, and update
2354 the BINFO_VIRTUALS list appropriately. */
2357 virtuals;
2361 binfo,
2366 }
2368 /* Update all of the primary and secondary vtables for T. Create new
2369 vtables as required, and initialize their RTTI information. Each
2370 of the functions in VIRTUALS is declared in T and may override a
2371 virtual function from a base class; find and modify the appropriate
2372 entries to point to the overriding functions. Returns a list, in
2373 declaration order, of the virtual functions that are declared in T,
2374 but do not appear in the primary base class vtable, and which
2375 should therefore be appended to the end of the vtable for T. */
2377 static tree
2379 {
2383 /* Update all of the vtables. */
2386 /* Add virtual functions not already in our primary vtable. These
2387 will be both those introduced by this class, and those overridden
2388 from secondary bases. It does not include virtuals merely
2389 inherited from secondary bases. */
2391 {
2396 {
2397 /* We don't need to adjust the `this' pointer when
2398 calling this function. */
2402 /* This is a function not already in our vtable. Keep it. */
2404 }
2405 else
2406 /* We've already got an entry for this function. Skip it. */
2408 }
2411 }
2413 /* Get the base virtual function declarations in T that have the
2414 indicated NAME. */
2416 static tree
2418 {
2419 tree methods;
2424 /* Find virtual functions in T with the indicated NAME. */
2428 methods;
2430 {
2436 }
2442 {
2445 base_fndecls);
2446 }
2449 }
2451 /* If this declaration supersedes the declaration of
2452 a method declared virtual in the base class, then
2453 mark this field as being virtual as well. */
2455 void
2457 {
2459 /* In [temp.mem] we have:
2461 A specialization of a member function template does not
2462 override a virtual function from a base class. */
2469 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2470 the error_mark_node so that we know it is an overriding
2471 function. */
2475 {
2479 }
2480 }
2482 /* Warn about hidden virtual functions that are not overridden in t.
2483 We know that constructors and destructors don't apply. */
2485 static void
2487 {
2489 tree fns;
2492 /* We go through each separately named virtual function. */
2496 {
2497 tree fn;
2498 tree name;
2499 tree fndecl;
2500 tree base_fndecls;
2501 tree base_binfo;
2502 tree binfo;
2505 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2506 have the same name. Figure out what name that is. */
2508 /* There are no possibly hidden functions yet. */
2510 /* Iterate through all of the base classes looking for possibly
2511 hidden functions. */
2514 {
2517 base_fndecls);
2518 }
2520 /* If there are no functions to hide, continue. */
2524 /* Remove any overridden functions. */
2526 {
2529 {
2533 /* If the method from the base class has the same
2534 signature as the method from the derived class, it
2535 has been overridden. */
2538 else
2540 }
2541 }
2543 /* Now give a warning for all base functions without overriders,
2544 as they are hidden. */
2546 {
2547 /* Here we know it is a hider, and no overrider exists. */
2551 }
2552 }
2553 }
2555 /* Check for things that are invalid. There are probably plenty of other
2556 things we should check for also. */
2558 static void
2560 {
2561 tree field;
2564 {
2572 {
2576 {
2577 /* We're generally only interested in entities the user
2578 declared, but we also find nested classes by noticing
2579 the TYPE_DECL that we create implicitly. You're
2580 allowed to put one anonymous union inside another,
2581 though, so we explicitly tolerate that. We use
2582 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2583 we also allow unnamed types used for defining fields. */
2590 {
2594 else
2598 }
2601 {
2604 else
2606 }
2608 {
2611 else
2613 }
2617 }
2618 }
2619 }
2620 }
2622 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2623 will be used later during class template instantiation.
2624 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2625 a non-static member data (FIELD_DECL), a member function
2626 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2627 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2628 When FRIEND_P is nonzero, T is either a friend class
2629 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2630 (FUNCTION_DECL, TEMPLATE_DECL). */
2632 void
2634 {
2635 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2640 }
2642 /* Create default constructors, assignment operators, and so forth for
2643 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2644 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2645 the class cannot have a default constructor, copy constructor
2646 taking a const reference argument, or an assignment operator taking
2647 a const reference, respectively. */
2649 static void
2653 {
2654 /* Destructor. */
2656 {
2657 /* In general, we create destructors lazily. */
2662 /* But if this is a Java class, any non-trivial destructor is
2663 invalid, even if compiler-generated. Therefore, if the
2664 destructor is non-trivial we create it now. */
2666 }
2668 /* [class.ctor]
2670 If there is no user-declared constructor for a class, a default
2671 constructor is implicitly declared. */
2673 {
2676 }
2678 /* [class.ctor]
2680 If a class definition does not explicitly declare a copy
2681 constructor, one is declared implicitly. */
2684 {
2690 }
2692 /* If there is no assignment operator, one will be created if and
2693 when it is needed. For now, just record whether or not the type
2694 of the parameter to the assignment operator will be a const or
2695 non-const reference. */
2698 {
2704 }
2706 /* We can't be lazy about declaring functions that might override
2707 a virtual function from a base class. */
2712 {
2714 tree base_binfo;
2718 {
2719 tree bv;
2721 {
2724 {
2729 }
2733 }
2734 }
2735 }
2736 }
2738 /* Subroutine of finish_struct_1. Recursively count the number of fields
2739 in TYPE, including anonymous union members. */
2741 static int
2743 {
2744 tree x;
2747 {
2750 else
2752 }
2754 }
2756 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2757 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2759 static int
2761 {
2762 tree x;
2764 {
2767 else
2769 }
2771 }
2773 /* FIELD is a bit-field. We are finishing the processing for its
2774 enclosing type. Issue any appropriate messages and set appropriate
2775 flags. Returns false if an error has been diagnosed. */
2777 static bool
2779 {
2781 tree w;
2783 /* Extract the declared width of the bitfield, which has been
2784 temporarily stashed in DECL_INITIAL. */
2787 /* Remove the bit-field width indicator so that the rest of the
2788 compiler does not treat that value as an initializer. */
2791 /* Detect invalid bit-field type. */
2793 {
2796 }
2797 else
2798 {
2799 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2802 /* detect invalid field size. */
2806 {
2809 }
2811 {
2814 }
2816 {
2819 }
2828 }
2831 {
2835 }
2836 else
2837 {
2838 /* Non-bit-fields are aligned for their type. */
2842 }
2843 }
2845 /* FIELD is a non bit-field. We are finishing the processing for its
2846 enclosing type T. Issue any appropriate messages and set appropriate
2847 flags. */
2849 static void
2851 tree t,
2855 {
2858 /* In C++98 an anonymous union cannot contain any fields which would change
2859 the settings of CANT_HAVE_CONST_CTOR and friends. */
2861 ;
2862 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
2863 structs. So, we recurse through their fields here. */
2865 {
2866 tree fields;
2872 }
2873 /* Check members with class type for constructors, destructors,
2874 etc. */
2876 {
2877 /* Never let anything with uninheritable virtuals
2878 make it through without complaint. */
2882 {
2887 field);
2892 field);
2894 {
2898 }
2899 }
2900 else
2901 {
2914 }
2923 }
2925 {
2926 /* `build_class_init_list' does not recognize
2927 non-FIELD_DECLs. */
2931 }
2932 }
2934 /* Check the data members (both static and non-static), class-scoped
2935 typedefs, etc., appearing in the declaration of T. Issue
2936 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2937 declaration order) of access declarations; each TREE_VALUE in this
2938 list is a USING_DECL.
2940 In addition, set the following flags:
2942 EMPTY_P
2943 The class is empty, i.e., contains no non-static data members.
2945 CANT_HAVE_CONST_CTOR_P
2946 This class cannot have an implicitly generated copy constructor
2947 taking a const reference.
2949 CANT_HAVE_CONST_ASN_REF
2950 This class cannot have an implicitly generated assignment
2951 operator taking a const reference.
2953 All of these flags should be initialized before calling this
2954 function.
2956 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2957 fields can be added by adding to this chain. */
2959 static void
2963 {
2971 /* Assume there are no access declarations. */
2973 /* Assume this class has no pointer members. */
2975 /* Assume none of the members of this class have default
2976 initializations. */
2980 {
2988 {
2989 /* Prune the access declaration from the list of fields. */
2992 /* Save the access declarations for our caller. */
2995 /* Since we've reset *FIELD there's no reason to skip to the
2996 next field. */
2999 }
3005 /* If we've gotten this far, it's a data member, possibly static,
3006 or an enumerator. */
3009 /* When this goes into scope, it will be a non-local reference. */
3013 {
3014 /* [class.union]
3016 If a union contains a static data member, or a member of
3017 reference type, the program is ill-formed. */
3019 {
3022 }
3024 {
3029 }
3030 }
3032 /* Perform error checking that did not get done in
3033 grokdeclarator. */
3035 {
3039 }
3041 {
3045 }
3053 /* Now it can only be a FIELD_DECL. */
3058 /* If at least one non-static data member is non-literal, the whole
3059 class becomes non-literal. */
3063 /* A standard-layout class is a class that:
3064 ...
3065 has the same access control (Clause 11) for all non-static data members,
3066 ... */
3073 /* If this is of reference type, check if it needs an init. */
3075 {
3081 /* ARM $12.6.2: [A member initializer list] (or, for an
3082 aggregate, initialization by a brace-enclosed list) is the
3083 only way to initialize nonstatic const and reference
3084 members. */
3087 }
3092 {
3094 {
3095 warning
3098 x);
3100 }
3104 }
3107 /* We don't treat zero-width bitfields as making a class
3108 non-empty. */
3109 ;
3110 else
3111 {
3112 /* The class is non-empty. */
3114 /* The class is not even nearly empty. */
3116 /* If one of the data members contains an empty class,
3117 so does T. */
3121 }
3123 /* This is used by -Weffc++ (see below). Warn only for pointers
3124 to members which might hold dynamic memory. So do not warn
3125 for pointers to functions or pointers to members. */
3132 {
3137 }
3143 /* DR 148 now allows pointers to members (which are POD themselves),
3144 to be allowed in POD structs. */
3153 /* We set DECL_C_BIT_FIELD in grokbitfield.
3154 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3157 cant_have_const_ctor_p,
3158 no_const_asn_ref_p,
3161 /* If any field is const, the structure type is pseudo-const. */
3163 {
3168 /* ARM $12.6.2: [A member initializer list] (or, for an
3169 aggregate, initialization by a brace-enclosed list) is the
3170 only way to initialize nonstatic const and reference
3171 members. */
3174 }
3175 /* A field that is pseudo-const makes the structure likewise. */
3177 {
3182 }
3184 /* Core issue 80: A nonstatic data member is required to have a
3185 different name from the class iff the class has a
3186 user-declared constructor. */
3190 }
3192 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3193 it should also define a copy constructor and an assignment operator to
3194 implement the correct copy semantic (deep vs shallow, etc.). As it is
3195 not feasible to check whether the constructors do allocate dynamic memory
3196 and store it within members, we approximate the warning like this:
3198 -- Warn only if there are members which are pointers
3199 -- Warn only if there is a non-trivial constructor (otherwise,
3200 there cannot be memory allocated).
3201 -- Warn only if there is a non-trivial destructor. We assume that the
3202 user at least implemented the cleanup correctly, and a destructor
3203 is needed to free dynamic memory.
3205 This seems enough for practical purposes. */
3207 && has_pointers
3211 {
3215 {
3220 }
3224 }
3226 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3230 /* Check anonymous struct/anonymous union fields. */
3233 /* We've built up the list of access declarations in reverse order.
3234 Fix that now. */
3236 }
3238 /* If TYPE is an empty class type, records its OFFSET in the table of
3239 OFFSETS. */
3241 static int
3243 {
3244 splay_tree_node n;
3249 /* Record the location of this empty object in OFFSETS. */
3257 type,
3261 }
3263 /* Returns nonzero if TYPE is an empty class type and there is
3264 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3266 static int
3268 {
3269 splay_tree_node n;
3270 tree t;
3275 /* Record the location of this empty object in OFFSETS. */
3285 }
3287 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3288 F for every subobject, passing it the type, offset, and table of
3289 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3290 be traversed.
3292 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3293 than MAX_OFFSET will not be walked.
3295 If F returns a nonzero value, the traversal ceases, and that value
3296 is returned. Otherwise, returns zero. */
3298 static int
3300 subobject_offset_fn f,
3301 tree offset,
3302 splay_tree offsets,
3303 tree max_offset,
3305 {
3309 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3310 stop. */
3318 {
3322 }
3325 {
3326 tree field;
3327 tree binfo;
3330 /* Avoid recursing into objects that are not interesting. */
3334 /* Record the location of TYPE. */
3339 /* Iterate through the direct base classes of TYPE. */
3343 {
3344 tree binfo_offset;
3357 offset,
3359 else
3360 {
3361 tree orig_binfo;
3362 /* We cannot rely on BINFO_OFFSET being set for the base
3363 class yet, but the offsets for direct non-virtual
3364 bases can be calculated by going back to the TYPE. */
3367 offset,
3369 }
3372 f,
3373 binfo_offset,
3374 offsets,
3375 max_offset,
3380 }
3383 {
3387 /* Iterate through the virtual base classes of TYPE. In G++
3388 3.2, we included virtual bases in the direct base class
3389 loop above, which results in incorrect results; the
3390 correct offsets for virtual bases are only known when
3391 working with the most derived type. */
3395 {
3397 f,
3399 offset,
3401 offsets,
3402 max_offset,
3406 }
3407 else
3408 {
3409 /* We still have to walk the primary base, if it is
3410 virtual. (If it is non-virtual, then it was walked
3411 above.) */
3417 {
3418 r = (walk_subobject_offsets
3423 }
3424 }
3425 }
3427 /* Iterate through the fields of TYPE. */
3430 {
3431 tree field_offset;
3435 else
3436 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3440 f,
3442 offset,
3443 field_offset),
3444 offsets,
3445 max_offset,
3449 }
3450 }
3452 {
3455 tree index;
3457 /* Avoid recursing into objects that are not interesting. */
3462 /* Step through each of the elements in the array. */
3464 /* G++ 3.2 had an off-by-one error here. */
3469 {
3471 f,
3472 offset,
3473 offsets,
3474 max_offset,
3480 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3481 there's no point in iterating through the remaining
3482 elements of the array. */
3485 }
3486 }
3489 }
3491 /* Record all of the empty subobjects of TYPE (either a type or a
3492 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3493 is being placed at OFFSET; otherwise, it is a base class that is
3494 being placed at OFFSET. */
3496 static void
3498 tree offset,
3499 splay_tree offsets,
3501 {
3502 tree max_offset;
3503 /* If recording subobjects for a non-static data member or a
3504 non-empty base class , we do not need to record offsets beyond
3505 the size of the biggest empty class. Additional data members
3506 will go at the end of the class. Additional base classes will go
3507 either at offset zero (if empty, in which case they cannot
3508 overlap with offsets past the size of the biggest empty class) or
3509 at the end of the class.
3511 However, if we are placing an empty base class, then we must record
3512 all offsets, as either the empty class is at offset zero (where
3513 other empty classes might later be placed) or at the end of the
3514 class (where other objects might then be placed, so other empty
3515 subobjects might later overlap). */
3519 else
3523 }
3525 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3526 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3527 virtual bases of TYPE are examined. */
3529 static int
3531 tree offset,
3532 splay_tree offsets,
3534 {
3535 splay_tree_node max_node;
3537 /* Get the node in OFFSETS that indicates the maximum offset where
3538 an empty subobject is located. */
3540 /* If there aren't any empty subobjects, then there's no point in
3541 performing this check. */
3547 vbases_p);
3548 }
3550 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3551 non-static data member of the type indicated by RLI. BINFO is the
3552 binfo corresponding to the base subobject, OFFSETS maps offsets to
3553 types already located at those offsets. This function determines
3554 the position of the DECL. */
3556 static void
3558 tree decl,
3559 tree binfo,
3560 splay_tree offsets)
3561 {
3564 tree type;
3567 {
3568 /* For the purposes of determining layout conflicts, we want to
3569 use the class type of BINFO; TREE_TYPE (DECL) will be the
3570 CLASSTYPE_AS_BASE version, which does not contain entries for
3571 zero-sized bases. */
3574 }
3575 else
3576 {
3579 }
3581 /* Try to place the field. It may take more than one try if we have
3582 a hard time placing the field without putting two objects of the
3583 same type at the same address. */
3585 {
3588 /* Place this field. */
3592 /* We have to check to see whether or not there is already
3593 something of the same type at the offset we're about to use.
3594 For example, consider:
3596 struct S {};
3597 struct T : public S { int i; };
3598 struct U : public S, public T {};
3600 Here, we put S at offset zero in U. Then, we can't put T at
3601 offset zero -- its S component would be at the same address
3602 as the S we already allocated. So, we have to skip ahead.
3603 Since all data members, including those whose type is an
3604 empty class, have nonzero size, any overlap can happen only
3605 with a direct or indirect base-class -- it can't happen with
3606 a data member. */
3607 /* In a union, overlap is permitted; all members are placed at
3608 offset zero. */
3611 /* G++ 3.2 did not check for overlaps when placing a non-empty
3612 virtual base. */
3617 {
3618 /* Strip off the size allocated to this field. That puts us
3619 at the first place we could have put the field with
3620 proper alignment. */
3623 /* Bump up by the alignment required for the type. */
3624 rli->bitpos
3630 }
3631 else
3632 /* There was no conflict. We're done laying out this field. */
3634 }
3636 /* Now that we know where it will be placed, update its
3637 BINFO_OFFSET. */
3639 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3640 this point because their BINFO_OFFSET is copied from another
3641 hierarchy. Therefore, we may not need to add the entire
3642 OFFSET. */
3648 }
3650 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3652 static int
3654 tree offset,
3655 splay_tree offsets ATTRIBUTE_UNUSED)
3656 {
3658 }
3660 /* Layout the empty base BINFO. EOC indicates the byte currently just
3661 past the end of the class, and should be correctly aligned for a
3662 class of the type indicated by BINFO; OFFSETS gives the offsets of
3663 the empty bases allocated so far. T is the most derived
3664 type. Return nonzero iff we added it at the end. */
3666 static bool
3669 {
3670 tree alignment;
3674 /* This routine should only be used for empty classes. */
3679 {
3681 propagate_binfo_offsets
3684 else
3686 "offset of empty base %qT may not be ABI-compliant and may"
3689 }
3691 /* This is an empty base class. We first try to put it at offset
3692 zero. */
3695 offsets,
3697 {
3698 /* That didn't work. Now, we move forward from the next
3699 available spot in the class. */
3703 {
3706 offsets,
3708 /* We finally found a spot where there's no overlap. */
3711 /* There's overlap here, too. Bump along to the next spot. */
3713 }
3714 }
3717 {
3722 }
3725 }
3727 /* Layout the base given by BINFO in the class indicated by RLI.
3728 *BASE_ALIGN is a running maximum of the alignments of
3729 any base class. OFFSETS gives the location of empty base
3730 subobjects. T is the most derived type. Return nonzero if the new
3731 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3732 *NEXT_FIELD, unless BINFO is for an empty base class.
3734 Returns the location at which the next field should be inserted. */
3739 {
3744 /* This error is now reported in xref_tag, thus giving better
3745 location information. */
3748 /* Place the base class. */
3750 {
3751 tree decl;
3753 /* The containing class is non-empty because it has a non-empty
3754 base class. */
3757 /* Create the FIELD_DECL. */
3764 {
3772 /* Try to place the field. It may take more than one try if we
3773 have a hard time placing the field without putting two
3774 objects of the same type at the same address. */
3776 /* Add the new FIELD_DECL to the list of fields for T. */
3780 }
3781 }
3782 else
3783 {
3784 tree eoc;
3787 /* On some platforms (ARM), even empty classes will not be
3788 byte-aligned. */
3793 /* A nearly-empty class "has no proper base class that is empty,
3794 not morally virtual, and at an offset other than zero." */
3796 {
3799 /* The check above (used in G++ 3.2) is insufficient because
3800 an empty class placed at offset zero might itself have an
3801 empty base at a nonzero offset. */
3803 empty_base_at_nonzero_offset_p,
3804 size_zero_node,
3808 {
3811 else
3813 "class %qT will be considered nearly empty in a "
3815 }
3816 }
3818 /* We do not create a FIELD_DECL for empty base classes because
3819 it might overlap some other field. We want to be able to
3820 create CONSTRUCTORs for the class by iterating over the
3821 FIELD_DECLs, and the back end does not handle overlapping
3822 FIELD_DECLs. */
3824 /* An empty virtual base causes a class to be non-empty
3825 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3826 here because that was already done when the virtual table
3827 pointer was created. */
3828 }
3830 /* Record the offsets of BINFO and its base subobjects. */
3833 offsets,
3837 }
3839 /* Layout all of the non-virtual base classes. Record empty
3840 subobjects in OFFSETS. T is the most derived type. Return nonzero
3841 if the type cannot be nearly empty. The fields created
3842 corresponding to the base classes will be inserted at
3843 *NEXT_FIELD. */
3845 static void
3848 {
3849 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3850 subobjects. */
3855 /* The primary base class is always allocated first. */
3860 /* Now allocate the rest of the bases. */
3862 {
3863 tree base_binfo;
3867 /* The primary base was already allocated above, so we don't
3868 need to allocate it again here. */
3872 /* Virtual bases are added at the end (a primary virtual base
3873 will have already been added). */
3879 }
3880 }
3882 /* Go through the TYPE_METHODS of T issuing any appropriate
3883 diagnostics, figuring out which methods override which other
3884 methods, and so forth. */
3886 static void
3888 {
3889 tree x;
3892 {
3896 /* The name of the field is the original field name
3897 Save this in auxiliary field for later overloading. */
3899 {
3903 }
3904 /* All user-provided destructors are non-trivial.
3905 Constructors and assignment ops are handled in
3906 grok_special_member_properties. */
3909 }
3910 }
3912 /* FN is a constructor or destructor. Clone the declaration to create
3913 a specialized in-charge or not-in-charge version, as indicated by
3914 NAME. */
3916 static tree
3918 {
3919 tree parms;
3920 tree clone;
3922 /* Copy the function. */
3924 /* Reset the function name. */
3927 /* Remember where this function came from. */
3929 /* Make it easy to find the CLONE given the FN. */
3933 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
3935 {
3942 }
3945 /* There's no pending inline data for this function. */
3949 /* The base-class destructor is not virtual. */
3951 {
3955 }
3957 /* If there was an in-charge parameter, drop it from the function
3958 type. */
3960 {
3961 tree basetype;
3962 tree parmtypes;
3963 tree exceptions;
3968 /* Skip the `this' parameter. */
3970 /* Skip the in-charge parameter. */
3972 /* And the VTT parm, in a complete [cd]tor. */
3976 /* If this is subobject constructor or destructor, add the vtt
3977 parameter. */
3981 parmtypes);
3984 exceptions);
3988 }
3990 /* Copy the function parameters. */
3992 /* Remove the in-charge parameter. */
3994 {
3998 }
3999 /* And the VTT parm, in a complete [cd]tor. */
4001 {
4004 else
4005 {
4009 }
4010 }
4013 {
4016 }
4018 /* Create the RTL for this function. */
4026 }
4028 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4029 not invoke this function directly.
4031 For a non-thunk function, returns the address of the slot for storing
4032 the function it is a clone of. Otherwise returns NULL_TREE.
4034 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4035 cloned_function is unset. This is to support the separate
4036 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4037 on a template makes sense, but not the former. */
4039 tree *
4041 {
4049 {
4050 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4053 else
4054 #endif
4056 }
4061 else
4063 }
4065 /* Produce declarations for all appropriate clones of FN. If
4066 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4067 CLASTYPE_METHOD_VEC as well. */
4069 void
4071 {
4072 tree clone;
4074 /* Avoid inappropriate cloning. */
4080 {
4081 /* For each constructor, we need two variants: an in-charge version
4082 and a not-in-charge version. */
4089 }
4090 else
4091 {
4094 /* For each destructor, we need three variants: an in-charge
4095 version, a not-in-charge version, and an in-charge deleting
4096 version. We clone the deleting version first because that
4097 means it will go second on the TYPE_METHODS list -- and that
4098 corresponds to the correct layout order in the virtual
4099 function table.
4101 For a non-virtual destructor, we do not build a deleting
4102 destructor. */
4104 {
4108 }
4115 }
4117 /* Note that this is an abstract function that is never emitted. */
4119 }
4121 /* DECL is an in charge constructor, which is being defined. This will
4122 have had an in class declaration, from whence clones were
4123 declared. An out-of-class definition can specify additional default
4124 arguments. As it is the clones that are involved in overload
4125 resolution, we must propagate the information from the DECL to its
4126 clones. */
4128 void
4130 {
4131 tree clone;
4135 {
4142 /* Skip the 'this' parameter. */
4158 {
4163 {
4164 /* A default parameter has been added. Adjust the
4165 clone's parameters. */
4169 tree type;
4174 {
4177 clone_parms);
4179 }
4182 clone_parms);
4191 }
4192 }
4194 }
4195 }
4197 /* For each of the constructors and destructors in T, create an
4198 in-charge and not-in-charge variant. */
4200 static void
4202 {
4203 tree fns;
4205 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4206 out now. */
4214 }
4216 /* Returns true iff class T has a user-defined constructor other than
4217 the default constructor. */
4219 bool
4221 {
4222 tree fns;
4228 {
4235 }
4238 }
4240 /* Returns the defaulted constructor if T has one. Otherwise, returns
4241 NULL_TREE. */
4243 tree
4245 {
4252 {
4256 {
4262 }
4263 }
4266 }
4268 /* Returns true iff FN is a user-provided function, i.e. user-declared
4269 and not defaulted at its first declaration; or explicit, private,
4270 protected, or non-const. */
4272 bool
4274 {
4277 else
4280 }
4282 /* Returns true iff class T has a user-provided constructor. */
4284 bool
4286 {
4287 tree fns;
4295 /* This can happen in error cases; avoid crashing. */
4304 }
4306 /* Returns true iff class T has a user-provided default constructor. */
4308 bool
4310 {
4311 tree fns;
4317 {
4323 }
4326 }
4328 /* Returns true iff class T has a constexpr default constructor. */
4330 bool
4332 {
4333 tree fns;
4339 }
4341 /* Returns true iff class TYPE has a virtual destructor. */
4343 bool
4345 {
4346 tree dtor;
4354 }
4356 /* Returns true iff class T has a move constructor. */
4358 bool
4360 {
4361 tree fns;
4364 {
4367 }
4377 }
4379 /* Returns true iff class T has a move assignment operator. */
4381 bool
4383 {
4384 tree fns;
4387 {
4390 }
4398 }
4400 /* Remove all zero-width bit-fields from T. */
4402 static void
4404 {
4409 {
4412 /* We should not be confused by the fact that grokbitfield
4413 temporarily sets the width of the bit field into
4414 DECL_INITIAL (*fieldsp).
4415 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
4416 to that width. */
4419 else
4421 }
4422 }
4424 /* Returns TRUE iff we need a cookie when dynamically allocating an
4425 array whose elements have the indicated class TYPE. */
4427 static bool
4429 {
4430 tree fns;
4435 /* If there's a non-trivial destructor, we need a cookie. In order
4436 to iterate through the array calling the destructor for each
4437 element, we'll have to know how many elements there are. */
4441 /* If the usual deallocation function is a two-argument whose second
4442 argument is of type `size_t', then we have to pass the size of
4443 the array to the deallocation function, so we will need to store
4444 a cookie. */
4448 /* If there are no `operator []' members, or the lookup is
4449 ambiguous, then we don't need a cookie. */
4452 /* Loop through all of the functions. */
4454 {
4455 tree fn;
4456 tree second_parm;
4458 /* Select the current function. */
4460 /* See if this function is a one-argument delete function. If
4461 it is, then it will be the usual deallocation function. */
4465 /* Do not consider this function if its second argument is an
4466 ellipsis. */
4469 /* Otherwise, if we have a two-argument function and the second
4470 argument is `size_t', it will be the usual deallocation
4471 function -- unless there is one-argument function, too. */
4475 }
4478 }
4480 /* Finish computing the `literal type' property of class type T.
4482 At this point, we have already processed base classes and
4483 non-static data members. We need to check whether the copy
4484 constructor is trivial, the destructor is trivial, and there
4485 is a trivial default constructor or at least one constexpr
4486 constructor other than the copy constructor. */
4488 static void
4490 {
4493 /* FIXME These constraints seem unnecessary; remove from standard.
4494 || !TYPE_HAS_TRIVIAL_COPY_CTOR (t)
4502 {
4503 tree fn;
4508 {
4511 }
4512 }
4513 }
4515 /* Check the validity of the bases and members declared in T. Add any
4516 implicitly-generated functions (like copy-constructors and
4517 assignment operators). Compute various flag bits (like
4518 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
4519 level: i.e., independently of the ABI in use. */
4521 static void
4523 {
4524 /* Nonzero if the implicitly generated copy constructor should take
4525 a non-const reference argument. */
4527 /* Nonzero if the implicitly generated assignment operator
4528 should take a non-const reference argument. */
4530 tree access_decls;
4533 tree fn;
4535 /* By default, we use const reference arguments and generate default
4536 constructors. */
4540 /* Check all the base-classes. */
4544 /* Check all the method declarations. */
4547 /* Save the initial values of these flags which only indicate whether
4548 or not the class has user-provided functions. As we analyze the
4549 bases and members we can set these flags for other reasons. */
4553 /* Check all the data member declarations. We cannot call
4554 check_field_decls until we have called check_bases check_methods,
4555 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4556 being set appropriately. */
4561 /* A nearly-empty class has to be vptr-containing; a nearly empty
4562 class contains just a vptr. */
4566 /* Do some bookkeeping that will guide the generation of implicitly
4567 declared member functions. */
4570 /* We need to call a constructor for this class if it has a
4571 user-provided constructor, or if the default constructor is going
4572 to initialize the vptr. (This is not an if-and-only-if;
4573 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
4574 themselves need constructing.) */
4577 /* [dcl.init.aggr]
4579 An aggregate is an array or a class with no user-provided
4580 constructors ... and no virtual functions.
4582 Again, other conditions for being an aggregate are checked
4583 elsewhere. */
4586 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
4587 retain the old definition internally for ABI reasons. */
4596 /* If the class has no user-declared constructor, but does have
4597 non-static const or reference data members that can never be
4598 initialized, issue a warning. */
4600 /* Classes with user-declared constructors are presumed to
4601 initialize these members. */
4603 /* Aggregates can be initialized with brace-enclosed
4604 initializers. */
4606 {
4607 tree field;
4610 {
4611 tree type;
4625 }
4626 }
4628 /* Synthesize any needed methods. */
4630 cant_have_const_ctor,
4631 no_const_asn_ref);
4633 /* Check defaulted declarations here so we have cant_have_const_ctor
4634 and don't need to worry about clones. */
4637 {
4640 {
4641 bool imp_const_p
4647 /* If the function is defaulted outside the class, we just
4648 give the synthesis error. */
4654 }
4656 }
4659 {
4660 /* "The closure type associated with a lambda-expression has a deleted
4661 default constructor and a deleted copy assignment operator." */
4667 /* "This class type is not an aggregate." */
4669 }
4671 /* Compute the 'literal type' property before we
4672 do anything with non-static member functions. */
4675 /* Create the in-charge and not-in-charge variants of constructors
4676 and destructors. */
4679 /* Process the using-declarations. */
4683 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4686 /* Figure out whether or not we will need a cookie when dynamically
4687 allocating an array of this type. */
4690 }
4692 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4693 accordingly. If a new vfield was created (because T doesn't have a
4694 primary base class), then the newly created field is returned. It
4695 is not added to the TYPE_FIELDS list; it is the caller's
4696 responsibility to do that. Accumulate declared virtual functions
4697 on VIRTUALS_P. */
4699 static tree
4701 {
4702 tree fn;
4704 /* Collect the virtual functions declared in T. */
4708 {
4717 }
4719 /* If we couldn't find an appropriate base class, create a new field
4720 here. Even if there weren't any new virtual functions, we might need a
4721 new virtual function table if we're supposed to include vptrs in
4722 all classes that need them. */
4724 {
4725 /* We build this decl with vtbl_ptr_type_node, which is a
4726 `vtable_entry_type*'. It might seem more precise to use
4727 `vtable_entry_type (*)[N]' where N is the number of virtual
4728 functions. However, that would require the vtable pointer in
4729 base classes to have a different type than the vtable pointer
4730 in derived classes. We could make that happen, but that
4731 still wouldn't solve all the problems. In particular, the
4732 type-based alias analysis code would decide that assignments
4733 to the base class vtable pointer can't alias assignments to
4734 the derived class vtable pointer, since they have different
4735 types. Thus, in a derived class destructor, where the base
4736 class constructor was inlined, we could generate bad code for
4737 setting up the vtable pointer.
4739 Therefore, we use one type for all vtable pointers. We still
4740 use a type-correct type; it's just doesn't indicate the array
4741 bounds. That's better than using `void*' or some such; it's
4742 cleaner, and it let's the alias analysis code know that these
4743 stores cannot alias stores to void*! */
4744 tree field;
4757 /* This class is non-empty. */
4761 }
4764 }
4766 /* Add OFFSET to all base types of BINFO which is a base in the
4767 hierarchy dominated by T.
4769 OFFSET, which is a type offset, is number of bytes. */
4771 static void
4773 {
4775 tree primary_binfo;
4776 tree base_binfo;
4778 /* Update BINFO's offset. */
4783 offset));
4785 /* Find the primary base class. */
4791 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4792 downwards. */
4794 {
4795 /* Don't do the primary base twice. */
4803 }
4804 }
4806 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4807 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4808 empty subobjects of T. */
4810 static void
4812 {
4813 tree vbase;
4822 {
4823 /* In G++ 3.2, we incorrectly rounded the size before laying out
4824 the virtual bases. */
4826 #ifdef STRUCTURE_SIZE_BOUNDARY
4827 /* Packed structures don't need to have minimum size. */
4830 #endif
4834 }
4836 /* Find the last field. The artificial fields created for virtual
4837 bases will go after the last extant field to date. */
4842 /* Go through the virtual bases, allocating space for each virtual
4843 base that is not already a primary base class. These are
4844 allocated in inheritance graph order. */
4846 {
4851 {
4854 /* This virtual base is not a primary base of any class in the
4855 hierarchy, so we have to add space for it. */
4859 /* If the first virtual base might have been placed at a
4860 lower address, had we started from CLASSTYPE_SIZE, rather
4861 than TYPE_SIZE, issue a warning. There can be both false
4862 positives and false negatives from this warning in rare
4863 cases; to deal with all the possibilities would probably
4864 require performing both layout algorithms and comparing
4865 the results which is not particularly tractable. */
4867 && first_vbase
4868 && (tree_int_cst_lt
4873 bitsize_unit_node),
4876 "offset of virtual base %qT is not ABI-compliant and "
4878 basetype);
4881 }
4882 }
4883 }
4885 /* Returns the offset of the byte just past the end of the base class
4886 BINFO. */
4888 static tree
4890 {
4891 tree size;
4896 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4897 allocate some space for it. It cannot have virtual bases, so
4898 TYPE_SIZE_UNIT is fine. */
4900 else
4904 }
4906 /* Returns the offset of the byte just past the end of the base class
4907 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4908 only non-virtual bases are included. */
4910 static tree
4912 {
4915 tree binfo;
4916 tree base_binfo;
4917 tree offset;
4922 {
4932 }
4934 /* G++ 3.2 did not check indirect virtual bases. */
4938 {
4942 }
4945 }
4947 /* Warn about bases of T that are inaccessible because they are
4948 ambiguous. For example:
4950 struct S {};
4951 struct T : public S {};
4952 struct U : public S, public T {};
4954 Here, `(S*) new U' is not allowed because there are two `S'
4955 subobjects of U. */
4957 static void
4959 {
4962 tree basetype;
4963 tree binfo;
4964 tree base_binfo;
4966 /* If there are no repeated bases, nothing can be ambiguous. */
4970 /* Check direct bases. */
4973 {
4979 }
4981 /* Check for ambiguous virtual bases. */
4985 {
4991 }
4992 }
4994 /* Compare two INTEGER_CSTs K1 and K2. */
4996 static int
4998 {
5000 }
5002 /* Increase the size indicated in RLI to account for empty classes
5003 that are "off the end" of the class. */
5005 static void
5007 {
5008 tree eoc;
5009 tree rli_size;
5011 /* It might be the case that we grew the class to allocate a
5012 zero-sized base class. That won't be reflected in RLI, yet,
5013 because we are willing to overlay multiple bases at the same
5014 offset. However, now we need to make sure that RLI is big enough
5015 to reflect the entire class. */
5021 {
5023 /* In version 1 of the ABI, the size of a class that ends with
5024 a bitfield was not rounded up to a whole multiple of a
5025 byte. Because rli_size_unit_so_far returns only the number
5026 of fully allocated bytes, any extra bits were not included
5027 in the size. */
5029 else
5030 /* The size should have been rounded to a whole byte. */
5033 rli->bitpos
5042 }
5043 }
5045 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5046 BINFO_OFFSETs for all of the base-classes. Position the vtable
5047 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5049 static void
5051 {
5052 tree non_static_data_members;
5053 tree field;
5054 tree vptr;
5055 record_layout_info rli;
5056 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5057 types that appear at that offset. */
5058 splay_tree empty_base_offsets;
5059 /* True if the last field layed out was a bit-field. */
5061 /* The location at which the next field should be inserted. */
5063 /* T, as a base class. */
5064 tree base_t;
5066 /* Keep track of the first non-static data member. */
5069 /* Start laying out the record. */
5072 /* Mark all the primary bases in the hierarchy. */
5075 /* Create a pointer to our virtual function table. */
5078 /* The vptr is always the first thing in the class. */
5080 {
5085 }
5086 else
5089 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5094 /* Layout the non-static data members. */
5096 {
5097 tree type;
5098 tree padding;
5100 /* We still pass things that aren't non-static data members to
5101 the back end, in case it wants to do something with them. */
5103 {
5105 /* If the static data member has incomplete type, keep track
5106 of it so that it can be completed later. (The handling
5107 of pending statics in finish_record_layout is
5108 insufficient; consider:
5110 struct S1;
5111 struct S2 { static S1 s1; };
5113 At this point, finish_record_layout will be called, but
5114 S1 is still incomplete.) */
5116 {
5118 /* The visibility of static data members is determined
5119 at their point of declaration, not their point of
5120 definition. */
5122 }
5124 }
5132 /* If this field is a bit-field whose width is greater than its
5133 type, then there are some special rules for allocating
5134 it. */
5137 {
5139 tree integer_type;
5141 /* We must allocate the bits as if suitably aligned for the
5142 longest integer type that fits in this many bits. type
5143 of the field. Then, we are supposed to use the left over
5144 bits as additional padding. */
5153 /* ITK now indicates a type that is too large for the
5154 field. We have to back up by one to find the largest
5155 type that fits. */
5156 do
5157 {
5162 /* Figure out how much additional padding is required. GCC
5163 3.2 always created a padding field, even if it had zero
5164 width. */
5167 {
5169 /* In a union, the padding field must have the full width
5170 of the bit-field; all fields start at offset zero. */
5172 else
5173 {
5176 "ABI-compliant and may change in a future "
5178 t);
5181 }
5182 }
5183 #ifdef PCC_BITFIELD_TYPE_MATTERS
5184 /* An unnamed bitfield does not normally affect the
5185 alignment of the containing class on a target where
5186 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5187 make any exceptions for unnamed bitfields when the
5188 bitfields are longer than their types. Therefore, we
5189 temporarily give the field a name. */
5191 {
5194 }
5195 #endif
5200 empty_base_offsets);
5203 /* Now that layout has been performed, set the size of the
5204 field to the size of its declared type; the rest of the
5205 field is effectively invisible. */
5207 /* We must also reset the DECL_MODE of the field. */
5212 /* Versions of G++ before G++ 3.4 did not reset the
5213 DECL_MODE. */
5215 "the offset of %qD may not be ABI-compliant and may "
5217 }
5218 else
5220 empty_base_offsets);
5222 /* Remember the location of any empty classes in FIELD. */
5226 empty_base_offsets,
5229 /* If a bit-field does not immediately follow another bit-field,
5230 and yet it starts in the middle of a byte, we have failed to
5231 comply with the ABI. */
5234 /* The TREE_NO_WARNING flag gets set by Objective-C when
5235 laying out an Objective-C class. The ObjC ABI differs
5236 from the C++ ABI, and so we do not want a warning
5237 here. */
5239 && !last_field_was_bitfield
5242 bitsize_unit_node)))
5246 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5247 offset of the field. */
5254 "classes to be placed at different locations in a "
5257 /* The middle end uses the type of expressions to determine the
5258 possible range of expression values. In order to optimize
5259 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5260 must be made aware of the width of "i", via its type.
5262 Because C++ does not have integer types of arbitrary width,
5263 we must (for the purposes of the front end) convert from the
5264 type assigned here to the declared type of the bitfield
5265 whenever a bitfield expression is used as an rvalue.
5266 Similarly, when assigning a value to a bitfield, the value
5267 must be converted to the type given the bitfield here. */
5269 {
5274 {
5281 }
5282 }
5284 /* If we needed additional padding after this field, add it
5285 now. */
5287 {
5288 tree padding_field;
5291 FIELD_DECL,
5292 NULL_TREE,
5293 char_type_node);
5300 NULL_TREE,
5301 empty_base_offsets);
5302 }
5305 }
5308 {
5309 /* Make sure that we are on a byte boundary so that the size of
5310 the class without virtual bases will always be a round number
5311 of bytes. */
5314 }
5316 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5317 padding. */
5321 /* Delete all zero-width bit-fields from the list of fields. Now
5322 that the type is laid out they are no longer important. */
5325 /* Create the version of T used for virtual bases. We do not use
5326 make_class_type for this version; this is an artificial type. For
5327 a POD type, we just reuse T. */
5329 {
5332 /* Set the size and alignment for the new type. In G++ 3.2, all
5333 empty classes were considered to have size zero when used as
5334 base classes. */
5336 {
5341 "layout of classes derived from empty class %qT "
5343 t);
5344 }
5345 else
5346 {
5347 tree eoc;
5349 /* If the ABI version is not at least two, and the last
5350 field was a bit-field, RLI may not be on a byte
5351 boundary. In particular, rli_size_unit_so_far might
5352 indicate the last complete byte, while rli_size_so_far
5353 indicates the total number of bits used. Therefore,
5354 rli_size_so_far, rather than rli_size_unit_so_far, is
5355 used to compute TYPE_SIZE_UNIT. */
5363 eoc);
5370 }
5374 /* Copy the fields from T. */
5378 {
5380 FIELD_DECL,
5390 }
5392 /* Record the base version of the type. */
5395 }
5396 else
5399 /* Every empty class contains an empty class. */
5403 /* Set the TYPE_DECL for this type to contain the right
5404 value for DECL_OFFSET, so that we can use it as part
5405 of a COMPONENT_REF for multiple inheritance. */
5408 /* Now fix up any virtual base class types that we left lying
5409 around. We must get these done before we try to lay out the
5410 virtual function table. As a side-effect, this will remove the
5411 base subobject fields. */
5414 /* Make sure that empty classes are reflected in RLI at this
5415 point. */
5418 /* Make sure not to create any structures with zero size. */
5424 /* If this is a non-POD, declaring it packed makes a difference to how it
5425 can be used as a field; don't let finalize_record_size undo it. */
5429 /* Let the back end lay out the type. */
5432 /* Warn about bases that can't be talked about due to ambiguity. */
5435 /* Now that we're done with layout, give the base fields the real types. */
5440 /* Clean up. */
5447 }
5449 /* Determine the "key method" for the class type indicated by TYPE,
5450 and set CLASSTYPE_KEY_METHOD accordingly. */
5452 void
5454 {
5455 tree method;
5458 || processing_template_decl
5463 /* The key method is the first non-pure virtual function that is not
5464 inline at the point of class definition. On some targets the
5465 key function may not be inline; those targets should not call
5466 this function until the end of the translation unit. */
5472 {
5475 }
5478 }
5480 /* Perform processing required when the definition of T (a class type)
5481 is complete. */
5483 void
5485 {
5486 tree x;
5487 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5492 {
5497 }
5499 /* If this type was previously laid out as a forward reference,
5500 make sure we lay it out again. */
5504 /* Make assumptions about the class; we'll reset the flags if
5505 necessary. */
5511 /* Do end-of-class semantic processing: checking the validity of the
5512 bases and members and add implicitly generated methods. */
5515 /* Find the key method. */
5517 {
5518 /* The Itanium C++ ABI permits the key method to be chosen when
5519 the class is defined -- even though the key method so
5520 selected may later turn out to be an inline function. On
5521 some systems (such as ARM Symbian OS) the key method cannot
5522 be determined until the end of the translation unit. On such
5523 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
5524 will cause the class to be added to KEYED_CLASSES. Then, in
5525 finish_file we will determine the key method. */
5529 /* If a polymorphic class has no key method, we may emit the vtable
5530 in every translation unit where the class definition appears. */
5533 }
5535 /* Layout the class itself. */
5538 /* We use the base type for trivial assignments, and hence it
5539 needs a mode. */
5544 /* If necessary, create the primary vtable for this class. */
5546 {
5547 /* We must enter these virtuals into the table. */
5551 /* Here we know enough to change the type of our virtual
5552 function table, but we will wait until later this function. */
5554 }
5557 {
5559 tree fn;
5566 /* Add entries for virtual functions introduced by this class. */
5570 /* Set DECL_VINDEX for all functions declared in this class. */
5572 fn;
5574 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5576 {
5580 /* A thunk. We should never be calling this entry directly
5581 from this vtable -- we'd use the entry for the non
5582 thunk base function. */
5586 }
5587 }
5591 /* Complete the rtl for any static member objects of the type we're
5592 working on. */
5599 /* Done with FIELDS...now decide whether to sort these for
5600 faster lookups later.
5602 We use a small number because most searches fail (succeeding
5603 ultimately as the search bores through the inheritance
5604 hierarchy), and we want this failure to occur quickly. */
5608 {
5614 field_decl_cmp);
5616 }
5618 /* Complain if one of the field types requires lower visibility. */
5621 /* Make the rtl for any new vtables we have created, and unmark
5622 the base types we marked. */
5625 /* Build the VTT for T. */
5628 /* This warning does not make sense for Java classes, since they
5629 cannot have destructors. */
5631 {
5632 tree dtor;
5636 if it were virtual, we would have created it by now. */
5637 !dtor
5646 "%q#T has virtual functions and accessible"
5648 }
5655 /* Class layout, assignment of virtual table slots, etc., is now
5656 complete. Give the back end a chance to tweak the visibility of
5657 the class or perform any other required target modifications. */
5664 /* Finish debugging output for this type. */
5666 }
5668 /* When T was built up, the member declarations were added in reverse
5669 order. Rearrange them to declaration order. */
5671 void
5673 {
5674 tree next;
5675 tree prev;
5676 tree x;
5678 /* The following lists are all in reverse order. Put them in
5679 declaration order now. */
5683 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5684 reverse order, so we can't just use nreverse. */
5689 {
5693 }
5695 {
5699 }
5700 }
5702 tree
5704 {
5707 /* Now that we've got all the field declarations, reverse everything
5708 as necessary. */
5713 /* Nadger the current location so that diagnostics point to the start of
5714 the struct, not the end. */
5718 {
5719 tree x;
5725 /* We need to emit an error message if this type was used as a parameter
5726 and it is an abstract type, even if it is a template. We construct
5727 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5728 account and we call complete_vars with this type, which will check
5729 the PARM_DECLS. Note that while the type is being defined,
5730 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5731 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5738 /* Remember current #pragma pack value. */
5740 }
5741 else
5750 else
5757 }
5758 \f
5759 /* Return the dynamic type of INSTANCE, if known.
5760 Used to determine whether the virtual function table is needed
5761 or not.
5763 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5764 of our knowledge of its type. *NONNULL should be initialized
5765 before this function is called. */
5767 static tree
5769 {
5770 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
5773 {
5777 else
5781 /* This is a call to a constructor, hence it's never zero. */
5783 {
5787 }
5791 /* This is a call to a constructor, hence it's never zero. */
5793 {
5797 }
5806 /* Propagate nonnull. */
5811 CASE_CONVERT:
5817 {
5818 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5819 with a real object -- given &p->f, p can still be null. */
5821 /* ??? Probably should check DECL_WEAK here. */
5824 }
5828 /* If this component is really a base class reference, then the field
5829 itself isn't definitive. */
5838 {
5842 }
5843 /* fall through... */
5848 {
5852 }
5854 {
5858 /* if we're in a ctor or dtor, we know our type. */
5862 {
5866 }
5867 }
5869 {
5870 /* We only need one hash table because it is always left empty. */
5874 htab_hash_pointer,
5875 htab_eq_pointer,
5878 /* Reference variables should be references to objects. */
5882 /* Enter the INSTANCE in a table to prevent recursion; a
5883 variable's initializer may refer to the variable
5884 itself. */
5888 {
5889 tree type;
5898 }
5899 }
5904 }
5905 #undef RECUR
5906 }
5908 /* Return nonzero if the dynamic type of INSTANCE is known, and
5909 equivalent to the static type. We also handle the case where
5910 INSTANCE is really a pointer. Return negative if this is a
5911 ctor/dtor. There the dynamic type is known, but this might not be
5912 the most derived base of the original object, and hence virtual
5913 bases may not be layed out according to this type.
5915 Used to determine whether the virtual function table is needed
5916 or not.
5918 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5919 of our knowledge of its type. *NONNULL should be initialized
5920 before this function is called. */
5922 int
5924 {
5935 }
5937 \f
5938 void
5940 {
5943 current_class_stack
5951 }
5953 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5955 static void
5957 {
5958 tree type;
5960 /* We are re-entering the same class we just left, so we don't
5961 have to search the whole inheritance matrix to find all the
5962 decls to bind again. Instead, we install the cached
5963 class_shadowed list and walk through it binding names. */
5966 /* Restore IDENTIFIER_TYPE_VALUE. */
5968 type;
5971 }
5973 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5974 appropriate for TYPE.
5976 So that we may avoid calls to lookup_name, we cache the _TYPE
5977 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5979 For multiple inheritance, we perform a two-pass depth-first search
5980 of the type lattice. */
5982 void
5984 {
5985 class_stack_node_t csn;
5989 /* Make sure there is enough room for the new entry on the stack. */
5991 {
5993 current_class_stack
5995 current_class_stack_size);
5996 }
5998 /* Insert a new entry on the class stack. */
6005 current_class_depth++;
6007 /* Now set up the new type. */
6013 /* By default, things in classes are private, while things in
6014 structures or unions are public. */
6016 ? access_private_node
6022 {
6023 /* Forcibly remove any old class remnants. */
6025 }
6031 else
6033 }
6035 /* When we exit a toplevel class scope, we save its binding level so
6036 that we can restore it quickly. Here, we've entered some other
6037 class, so we must invalidate our cache. */
6039 void
6041 {
6043 }
6045 /* Get out of the current class scope. If we were in a class scope
6046 previously, that is the one popped to. */
6048 void
6050 {
6053 current_class_depth--;
6059 }
6061 /* Mark the top of the class stack as hidden. */
6063 void
6065 {
6068 }
6070 /* Mark the top of the class stack as un-hidden. */
6072 void
6074 {
6077 }
6079 /* Returns 1 if the class type currently being defined is either T or
6080 a nested type of T. */
6082 bool
6084 {
6092 /* We start looking from 1 because entry 0 is from global scope,
6093 and has no type. */
6095 {
6096 tree c;
6099 else
6100 {
6104 }
6109 }
6111 }
6113 /* If either current_class_type or one of its enclosing classes are derived
6114 from T, return the appropriate type. Used to determine how we found
6115 something via unqualified lookup. */
6117 tree
6119 {
6122 /* The bases of a dependent type are unknown. */
6133 {
6138 }
6141 }
6143 /* Returns the innermost class type which is not a lambda closure type. */
6145 tree
6147 {
6150 /* We start looking from 1 because entry 0 is from global scope,
6151 and has no type. */
6153 {
6154 tree c;
6157 else
6158 {
6162 }
6167 }
6169 }
6171 /* When entering a class scope, all enclosing class scopes' names with
6172 static meaning (static variables, static functions, types and
6173 enumerators) have to be visible. This recursive function calls
6174 pushclass for all enclosing class contexts until global or a local
6175 scope is reached. TYPE is the enclosed class. */
6177 void
6179 {
6180 /* A namespace might be passed in error cases, like A::B:C. */
6188 }
6190 /* Undoes a push_nested_class call. */
6192 void
6194 {
6200 }
6202 /* Returns the number of extern "LANG" blocks we are nested within. */
6204 int
6206 {
6208 }
6210 /* Set global variables CURRENT_LANG_NAME to appropriate value
6211 so that behavior of name-mangling machinery is correct. */
6213 void
6215 {
6219 {
6221 }
6223 {
6225 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
6226 (See record_builtin_java_type in decl.c.) However, that causes
6227 incorrect debug entries if these types are actually used.
6228 So we re-enable debug output after extern "Java". */
6237 }
6239 {
6241 }
6242 else
6244 }
6246 /* Get out of the current language scope. */
6248 void
6250 {
6252 }
6253 \f
6254 /* Type instantiation routines. */
6256 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
6257 matches the TARGET_TYPE. If there is no satisfactory match, return
6258 error_mark_node, and issue an error & warning messages under
6259 control of FLAGS. Permit pointers to member function if FLAGS
6260 permits. If TEMPLATE_ONLY, the name of the overloaded function was
6261 a template-id, and EXPLICIT_TARGS are the explicitly provided
6262 template arguments.
6264 If OVERLOAD is for one or more member functions, then ACCESS_PATH
6265 is the base path used to reference those member functions. If
6266 TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is
6267 resolved to a member function, access checks will be performed and
6268 errors issued if appropriate. */
6270 static tree
6272 tree overload,
6273 tsubst_flags_t flags,
6275 tree explicit_targs,
6276 tree access_path)
6277 {
6278 /* Here's what the standard says:
6280 [over.over]
6282 If the name is a function template, template argument deduction
6283 is done, and if the argument deduction succeeds, the deduced
6284 arguments are used to generate a single template function, which
6285 is added to the set of overloaded functions considered.
6287 Non-member functions and static member functions match targets of
6288 type "pointer-to-function" or "reference-to-function." Nonstatic
6289 member functions match targets of type "pointer-to-member
6290 function;" the function type of the pointer to member is used to
6291 select the member function from the set of overloaded member
6292 functions. If a nonstatic member function is selected, the
6293 reference to the overloaded function name is required to have the
6294 form of a pointer to member as described in 5.3.1.
6296 If more than one function is selected, any template functions in
6297 the set are eliminated if the set also contains a non-template
6298 function, and any given template function is eliminated if the
6299 set contains a second template function that is more specialized
6300 than the first according to the partial ordering rules 14.5.5.2.
6301 After such eliminations, if any, there shall remain exactly one
6302 selected function. */
6305 /* We store the matches in a TREE_LIST rooted here. The functions
6306 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
6307 interoperability with most_specialized_instantiation. */
6309 tree fn;
6310 tree target_fn_type;
6312 /* By the time we get here, we should be seeing only real
6313 pointer-to-member types, not the internal POINTER_TYPE to
6314 METHOD_TYPE representation. */
6320 /* Check that the TARGET_TYPE is reasonable. */
6324 /* This is OK, too. */
6327 /* This is OK, too. This comes from a conversion to reference
6328 type. */
6330 else
6331 {
6337 }
6339 /* Non-member functions and static member functions match targets of type
6340 "pointer-to-function" or "reference-to-function." Nonstatic member
6341 functions match targets of type "pointer-to-member-function;" the
6342 function type of the pointer to member is used to select the member
6343 function from the set of overloaded member functions.
6345 So figure out the FUNCTION_TYPE that we want to match against. */
6348 /* If we can find a non-template function that matches, we can just
6349 use it. There's no point in generating template instantiations
6350 if we're just going to throw them out anyhow. But, of course, we
6351 can only do this when we don't *need* a template function. */
6353 {
6354 tree fns;
6357 {
6361 /* We're not looking for templates just yet. */
6366 /* We're looking for a non-static member, and this isn't
6367 one, or vice versa. */
6370 /* Ignore functions which haven't been explicitly
6371 declared. */
6375 /* See if there's a match. */
6378 }
6379 }
6381 /* Now, if we've already got a match (or matches), there's no need
6382 to proceed to the template functions. But, if we don't have a
6383 match we need to look at them, too. */
6385 {
6386 tree target_arg_types;
6387 tree target_ret_type;
6388 tree fns;
6391 tree arg;
6405 {
6407 tree instantiation;
6408 tree targs;
6411 /* We're only looking for templates. */
6416 /* We're not looking for a non-static member, and this is
6417 one, or vice versa. */
6420 /* Try to do argument deduction. */
6424 LOOKUP_NORMAL))
6425 /* Argument deduction failed. */
6428 /* Instantiate the template. */
6431 /* Instantiation failed. */
6434 /* See if there's a match. */
6437 }
6439 /* Now, remove all but the most specialized of the matches. */
6441 {
6446 NULL_TREE,
6447 NULL_TREE);
6448 }
6449 }
6451 /* Now we should have exactly one function in MATCHES. */
6453 {
6454 /* There were *no* matches. */
6456 {
6459 target_type);
6461 /* print_candidates expects a chain with the functions in
6462 TREE_VALUE slots, so we cons one up here (we're losing anyway,
6463 so why be clever?). */
6466 matches);
6469 }
6471 }
6473 {
6474 /* There were too many matches. First check if they're all
6475 the same function. */
6476 tree match;
6484 {
6486 {
6489 target_type);
6491 /* Since print_candidates expects the functions in the
6492 TREE_VALUE slot, we flip them here. */
6497 }
6500 }
6501 }
6503 /* Good, exactly one match. Now, convert it to the correct type. */
6508 {
6516 {
6519 }
6520 }
6522 /* If we're doing overload resolution purely for the purpose of
6523 determining conversion sequences, we should not consider the
6524 function used. If this conversion sequence is selected, the
6525 function will be marked as used at this point. */
6527 {
6528 /* Make =delete work with SFINAE. */
6533 }
6535 /* We could not check access to member functions when this
6536 expression was originally created since we did not know at that
6537 time to which function the expression referred. */
6540 {
6543 }
6547 else
6548 {
6549 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
6550 will mark the function as addressed, but here we must do it
6551 explicitly. */
6555 }
6556 }
6558 /* This function will instantiate the type of the expression given in
6559 RHS to match the type of LHSTYPE. If errors exist, then return
6560 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
6561 we complain on errors. If we are not complaining, never modify rhs,
6562 as overload resolution wants to try many possible instantiations, in
6563 the hope that at least one will work.
6565 For non-recursive calls, LHSTYPE should be a function, pointer to
6566 function, or a pointer to member function. */
6568 tree
6570 {
6577 {
6581 }
6584 {
6590 /* Microsoft allows `A::f' to be resolved to a
6591 pointer-to-member. */
6592 ;
6593 else
6594 {
6599 }
6600 }
6603 {
6606 }
6608 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
6609 deduce any type information. */
6611 {
6615 }
6617 /* There only a few kinds of expressions that may have a type
6618 dependent on overload resolution. */
6624 /* This should really only be used when attempting to distinguish
6625 what sort of a pointer to function we have. For now, any
6626 arithmetic operation which is not supported on pointers
6627 is rejected as an error. */
6630 {
6632 {
6638 /* Do not lose object's side effects. */
6642 }
6649 /* This can happen if we are forming a pointer-to-member for a
6650 member template. */
6653 /* Fall through. */
6656 {
6660 return
6664 }
6668 return
6672 access_path);
6675 {
6680 }
6687 }
6689 }
6690 \f
6691 /* Return the name of the virtual function pointer field
6692 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6693 this may have to look back through base types to find the
6694 ultimate field name. (For single inheritance, these could
6695 all be the same name. Who knows for multiple inheritance). */
6697 static tree
6699 {
6706 {
6712 }
6720 }
6722 void
6724 {
6725 #ifdef GATHER_STATISTICS
6729 {
6734 }
6735 #endif
6736 }
6738 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6739 according to [class]:
6740 The class-name is also inserted
6741 into the scope of the class itself. For purposes of access checking,
6742 the inserted class name is treated as if it were a public member name. */
6744 void
6746 {
6749 tree saved_cas;
6764 }
6766 /* Returns 1 if TYPE contains only padding bytes. */
6768 int
6770 {
6777 /* In G++ 3.2, whether or not a class was empty was determined by
6778 looking at its size. */
6781 else
6783 }
6785 /* Returns true if TYPE contains an empty class. */
6787 static bool
6789 {
6793 {
6794 tree field;
6795 tree binfo;
6796 tree base_binfo;
6808 }
6812 }
6814 /* Returns true if TYPE contains no actual data, just various
6815 possible combinations of empty classes. */
6817 bool
6819 {
6823 {
6824 tree field;
6825 tree binfo;
6826 tree base_binfo;
6839 }
6843 }
6845 /* Note that NAME was looked up while the current class was being
6846 defined and that the result of that lookup was DECL. */
6848 void
6850 {
6851 splay_tree names_used;
6853 /* If we're not defining a class, there's nothing to do. */
6859 /* If there's already a binding for this NAME, then we don't have
6860 anything to worry about. */
6873 }
6875 /* Note that NAME was declared (as DECL) in the current class. Check
6876 to see that the declaration is valid. */
6878 void
6880 {
6881 splay_tree names_used;
6882 splay_tree_node n;
6884 /* Look to see if we ever used this name. */
6885 names_used
6889 /* The C language allows members to be declared with a type of the same
6890 name, and the C++ standard says this diagnostic is not required. So
6891 allow it in extern "C" blocks unless predantic is specified.
6892 Allow it in all cases if -ms-extensions is specified. */
6898 {
6899 /* [basic.scope.class]
6901 A name N used in a class S shall refer to the same declaration
6902 in its context and when re-evaluated in the completed scope of
6903 S. */
6907 }
6908 }
6910 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6911 Secondary vtables are merged with primary vtables; this function
6912 will return the VAR_DECL for the primary vtable. */
6914 tree
6916 {
6917 tree decl;
6921 {
6924 }
6928 }
6931 /* Returns the binfo for the primary base of BINFO. If the resulting
6932 BINFO is a virtual base, and it is inherited elsewhere in the
6933 hierarchy, then the returned binfo might not be the primary base of
6934 BINFO in the complete object. Check BINFO_PRIMARY_P or
6935 BINFO_LOST_PRIMARY_P to be sure. */
6937 static tree
6939 {
6940 tree primary_base;
6947 }
6949 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6951 static int
6953 {
6957 }
6959 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6960 INDENT should be zero when called from the top level; it is
6961 incremented recursively. IGO indicates the next expected BINFO in
6962 inheritance graph ordering. */
6964 static tree
6967 tree binfo,
6968 tree igo,
6970 {
6972 tree base_binfo;
6980 {
6983 }
6998 {
7002 TFF_PLAIN_IDENTIFIER),
7004 }
7006 {
7009 }
7014 {
7018 {
7022 TFF_PLAIN_IDENTIFIER));
7023 }
7025 {
7029 TFF_PLAIN_IDENTIFIER));
7030 }
7032 {
7036 TFF_PLAIN_IDENTIFIER));
7037 }
7039 {
7043 TFF_PLAIN_IDENTIFIER));
7044 }
7048 }
7054 }
7056 /* Dump the BINFO hierarchy for T. */
7058 static void
7060 {
7072 }
7074 /* Debug interface to hierarchy dumping. */
7076 void
7078 {
7080 }
7082 static void
7084 {
7089 {
7092 }
7093 }
7095 static void
7097 {
7098 tree value;
7100 HOST_WIDE_INT elt;
7108 TFF_PLAIN_IDENTIFIER));
7115 }
7117 static void
7119 {
7127 {
7134 {
7138 }
7142 }
7145 }
7147 static void
7149 {
7157 {
7162 }
7165 }
7167 /* Dump a function or thunk and its thunkees. */
7169 static void
7171 {
7174 tree thunks;
7182 {
7192 else
7198 }
7202 }
7204 /* Dump the thunks for FN. */
7206 void
7208 {
7210 }
7212 /* Virtual function table initialization. */
7214 /* Create all the necessary vtables for T and its base classes. */
7216 static void
7218 {
7219 tree vbase;
7223 /* We lay out the primary and secondary vtables in one contiguous
7224 vtable. The primary vtable is first, followed by the non-virtual
7225 secondary vtables in inheritance graph order. */
7229 /* Then come the virtual bases, also in inheritance graph order. */
7231 {
7235 }
7239 }
7241 /* Initialize the vtable for BINFO with the INITS. */
7243 static void
7245 {
7246 tree decl;
7252 }
7254 /* Build the VTT (virtual table table) for T.
7255 A class requires a VTT if it has virtual bases.
7257 This holds
7258 1 - primary virtual pointer for complete object T
7259 2 - secondary VTTs for each direct non-virtual base of T which requires a
7260 VTT
7261 3 - secondary virtual pointers for each direct or indirect base of T which
7262 has virtual bases or is reachable via a virtual path from T.
7263 4 - secondary VTTs for each direct or indirect virtual base of T.
7265 Secondary VTTs look like complete object VTTs without part 4. */
7267 static void
7269 {
7270 tree type;
7271 tree vtt;
7272 tree index;
7275 /* Build up the initializers for the VTT. */
7280 /* If we didn't need a VTT, we're done. */
7284 /* Figure out the type of the VTT. */
7288 /* Now, build the VTT object itself. */
7291 /* Add the VTT to the vtables list. */
7296 }
7298 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7299 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7300 and CHAIN the vtable pointer for this binfo after construction is
7301 complete. VALUE can also be another BINFO, in which case we recurse. */
7303 static tree
7305 {
7306 tree vt;
7309 {
7315 else
7317 }
7320 }
7322 /* Data for secondary VTT initialization. */
7324 {
7325 /* Is this the primary VTT? */
7328 /* Current index into the VTT. */
7329 tree index;
7331 /* Vector of initializers built up. */
7334 /* The type being constructed by this secondary VTT. */
7335 tree type_being_constructed;
7338 /* Recursively build the VTT-initializer for BINFO (which is in the
7339 hierarchy dominated by T). INITS points to the end of the initializer
7340 list to date. INDEX is the VTT index where the next element will be
7341 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7342 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7343 for virtual bases of T. When it is not so, we build the constructor
7344 vtables for the BINFO-in-T variant. */
7346 static void
7348 {
7350 tree b;
7351 tree init;
7352 secondary_vptr_vtt_init_data data;
7355 /* We only need VTTs for subobjects with virtual bases. */
7359 /* We need to use a construction vtable if this is not the primary
7360 VTT. */
7362 {
7365 /* Record the offset in the VTT where this sub-VTT can be found. */
7367 }
7369 /* Add the address of the primary vtable for the complete object. */
7373 {
7376 }
7379 /* Recursively add the secondary VTTs for non-virtual bases. */
7384 /* Add secondary virtual pointers for all subobjects of BINFO with
7385 either virtual bases or reachable along a virtual path, except
7386 subobjects that are non-virtual primary bases. */
7396 /* data.inits might have grown as we added secondary virtual pointers.
7397 Make sure our caller knows about the new vector. */
7401 /* Add the secondary VTTs for virtual bases in inheritance graph
7402 order. */
7404 {
7409 }
7410 else
7411 /* Remove the ctor vtables we created. */
7413 }
7415 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
7416 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
7418 static tree
7420 {
7423 /* We don't care about bases that don't have vtables. */
7427 /* We're only interested in proper subobjects of the type being
7428 constructed. */
7432 /* We're only interested in bases with virtual bases or reachable
7433 via a virtual path from the type being constructed. */
7438 /* We're not interested in non-virtual primary bases. */
7442 /* Record the index where this secondary vptr can be found. */
7444 {
7449 {
7450 /* It's a primary virtual base, and this is not a
7451 construction vtable. Find the base this is primary of in
7452 the inheritance graph, and use that base's vtable
7453 now. */
7456 }
7457 }
7459 /* Add the initializer for the secondary vptr itself. */
7462 /* Advance the vtt index. */
7467 }
7469 /* Called from build_vtt_inits via dfs_walk. After building
7470 constructor vtables and generating the sub-vtt from them, we need
7471 to restore the BINFO_VTABLES that were scribbled on. DATA is the
7472 binfo of the base whose sub vtt was generated. */
7474 static tree
7476 {
7480 /* If this class has no vtable, none of its bases do. */
7484 /* This might be a primary base, so have no vtable in this
7485 hierarchy. */
7488 /* If we scribbled the construction vtable vptr into BINFO, clear it
7489 out now. */
7495 }
7497 /* Build the construction vtable group for BINFO which is in the
7498 hierarchy dominated by T. */
7500 static void
7502 {
7503 tree type;
7504 tree vtbl;
7505 tree id;
7506 tree vbase;
7509 /* See if we've already created this construction vtable group. */
7515 /* Build a version of VTBL (with the wrong type) for use in
7516 constructing the addresses of secondary vtables in the
7517 construction vtable group. */
7525 /* Add the vtables for each of our virtual bases using the vbase in T
7526 binfo. */
7528 vbase;
7530 {
7531 tree b;
7538 }
7540 /* Figure out the type of the construction vtable. */
7548 /* Initialize the construction vtable. */
7552 }
7554 /* Add the vtbl initializers for BINFO (and its bases other than
7555 non-virtual primaries) to the list of INITS. BINFO is in the
7556 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7557 the constructor the vtbl inits should be accumulated for. (If this
7558 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7559 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7560 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7561 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7562 but are not necessarily the same in terms of layout. */
7564 static void
7566 tree orig_binfo,
7567 tree rtti_binfo,
7568 tree vtbl,
7569 tree t,
7571 {
7573 tree base_binfo;
7578 /* If it doesn't have a vptr, we don't do anything. */
7582 /* If we're building a construction vtable, we're not interested in
7583 subobjects that don't require construction vtables. */
7589 /* Build the initializers for the BINFO-in-T vtable. */
7592 /* Walk the BINFO and its bases. We walk in preorder so that as we
7593 initialize each vtable we can figure out at what offset the
7594 secondary vtable lies from the primary vtable. We can't use
7595 dfs_walk here because we need to iterate through bases of BINFO
7596 and RTTI_BINFO simultaneously. */
7598 {
7599 /* Skip virtual bases. */
7605 inits);
7606 }
7607 }
7609 /* Called from accumulate_vtbl_inits. Adds the initializers for the
7610 BINFO vtable to L. */
7612 static void
7614 tree orig_binfo,
7615 tree rtti_binfo,
7616 tree orig_vtbl,
7617 tree t,
7619 {
7626 {
7627 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7628 primary virtual base. If it is not the same primary in
7629 the hierarchy of T, we'll need to generate a ctor vtable
7630 for it, to place at its location in T. If it is the same
7631 primary, we still need a VTT entry for the vtable, but it
7632 should point to the ctor vtable for the base it is a
7633 primary for within the sub-hierarchy of RTTI_BINFO.
7635 There are three possible cases:
7637 1) We are in the same place.
7638 2) We are a primary base within a lost primary virtual base of
7639 RTTI_BINFO.
7640 3) We are primary to something not a base of RTTI_BINFO. */
7642 tree b;
7645 /* First, look through the bases we are primary to for RTTI_BINFO
7646 or a virtual base. */
7649 {
7654 }
7655 /* If we run out of primary links, keep looking down our
7656 inheritance chain; we might be an indirect primary. */
7660 found:
7662 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7663 base B and it is a base of RTTI_BINFO, this is case 2. In
7664 either case, we share our vtable with LAST, i.e. the
7665 derived-most base within B of which we are a primary. */
7668 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7669 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7670 binfo_ctor_vtable after everything's been set up. */
7673 /* Otherwise, this is case 3 and we get our own. */
7674 }
7681 {
7682 tree index;
7685 /* Add the initializer for this vtable. */
7689 /* Figure out the position to which the VPTR should point. */
7696 index);
7698 }
7701 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7702 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7703 straighten this out. */
7706 /* Throw away any unneeded intializers. */
7708 else
7709 /* For an ordinary vtable, set BINFO_VTABLE. */
7711 }
7715 /* Construct the initializer for BINFO's virtual function table. BINFO
7716 is part of the hierarchy dominated by T. If we're building a
7717 construction vtable, the ORIG_BINFO is the binfo we should use to
7718 find the actual function pointers to put in the vtable - but they
7719 can be overridden on the path to most-derived in the graph that
7720 ORIG_BINFO belongs. Otherwise,
7721 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7722 BINFO that should be indicated by the RTTI information in the
7723 vtable; it will be a base class of T, rather than T itself, if we
7724 are building a construction vtable.
7726 The value returned is a TREE_LIST suitable for wrapping in a
7727 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7728 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7729 number of non-function entries in the vtable.
7731 It might seem that this function should never be called with a
7732 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7733 base is always subsumed by a derived class vtable. However, when
7734 we are building construction vtables, we do build vtables for
7735 primary bases; we need these while the primary base is being
7736 constructed. */
7738 static void
7740 tree orig_binfo,
7741 tree t,
7742 tree rtti_binfo,
7745 {
7746 tree v;
7747 vtbl_init_data vid;
7749 tree vbinfo;
7753 /* Initialize VID. */
7761 /* The first vbase or vcall offset is at index -3 in the vtable. */
7764 /* Add entries to the vtable for RTTI. */
7767 /* Create an array for keeping track of the functions we've
7768 processed. When we see multiple functions with the same
7769 signature, we share the vcall offsets. */
7771 /* Add the vcall and vbase offset entries. */
7774 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7775 build_vbase_offset_vtbl_entries. */
7780 /* If the target requires padding between data entries, add that now. */
7782 {
7788 /* Move data entries into their new positions and add padding
7789 after the new positions. Iterate backwards so we don't
7790 overwrite entries that we would need to process later. */
7793 ix--)
7794 {
7802 {
7807 null_pointer_node);
7808 }
7809 }
7810 }
7815 /* The initializers for virtual functions were built up in reverse
7816 order. Straighten them out and add them to the running list in one
7817 step. */
7827 /* Go through all the ordinary virtual functions, building up
7828 initializers. */
7830 {
7831 tree delta;
7832 tree vcall_index;
7839 {
7843 {
7846 }
7848 }
7850 /* If the only definition of this function signature along our
7851 primary base chain is from a lost primary, this vtable slot will
7852 never be used, so just zero it out. This is important to avoid
7853 requiring extra thunks which cannot be generated with the function.
7855 We first check this in update_vtable_entry_for_fn, so we handle
7856 restored primary bases properly; we also need to do it here so we
7857 zero out unused slots in ctor vtables, rather than filling them
7858 with erroneous values (though harmless, apart from relocation
7859 costs). */
7864 {
7865 /* Pull the offset for `this', and the function to call, out of
7866 the list. */
7873 /* You can't call an abstract virtual function; it's abstract.
7874 So, we replace these functions with __pure_virtual. */
7876 {
7879 {
7881 abort_fndecl_addr
7885 }
7886 }
7887 else
7888 {
7890 {
7894 }
7895 /* Take the address of the function, considering it to be of an
7896 appropriate generic type. */
7900 }
7901 }
7903 /* And add it to the chain of initializers. */
7905 {
7910 else
7912 {
7918 }
7919 }
7920 else
7922 }
7923 }
7925 /* Adds to vid->inits the initializers for the vbase and vcall
7926 offsets in BINFO, which is in the hierarchy dominated by T. */
7928 static void
7930 {
7931 tree b;
7933 /* If this is a derived class, we must first create entries
7934 corresponding to the primary base class. */
7939 /* Add the vbase entries for this base. */
7941 /* Add the vcall entries for this base. */
7943 }
7945 /* Returns the initializers for the vbase offset entries in the vtable
7946 for BINFO (which is part of the class hierarchy dominated by T), in
7947 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7948 where the next vbase offset will go. */
7950 static void
7952 {
7953 tree vbase;
7954 tree t;
7955 tree non_primary_binfo;
7957 /* If there are no virtual baseclasses, then there is nothing to
7958 do. */
7964 /* We might be a primary base class. Go up the inheritance hierarchy
7965 until we find the most derived class of which we are a primary base:
7966 it is the offset of that which we need to use. */
7969 {
7970 tree b;
7972 /* If we have reached a virtual base, then it must be a primary
7973 base (possibly multi-level) of vid->binfo, or we wouldn't
7974 have called build_vcall_and_vbase_vtbl_entries for it. But it
7975 might be a lost primary, so just skip down to vid->binfo. */
7977 {
7980 }
7986 }
7988 /* Go through the virtual bases, adding the offsets. */
7990 vbase;
7992 {
7993 tree b;
7994 tree delta;
7999 /* Find the instance of this virtual base in the complete
8000 object. */
8003 /* If we've already got an offset for this virtual base, we
8004 don't need another one. */
8009 /* Figure out where we can find this vbase offset. */
8018 /* The vbase offset had better be the same. */
8021 /* The next vbase will come at a more negative offset. */
8025 /* The initializer is the delta from BINFO to this virtual base.
8026 The vbase offsets go in reverse inheritance-graph order, and
8027 we are walking in inheritance graph order so these end up in
8028 the right order. */
8035 }
8036 }
8038 /* Adds the initializers for the vcall offset entries in the vtable
8039 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8040 to VID->INITS. */
8042 static void
8044 {
8045 /* We only need these entries if this base is a virtual base. We
8046 compute the indices -- but do not add to the vtable -- when
8047 building the main vtable for a class. */
8050 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8051 correspond to VID->DERIVED), we are building a primary
8052 construction virtual table. Since this is a primary
8053 virtual table, we do not need the vcall offsets for
8054 BINFO. */
8056 {
8057 /* We need a vcall offset for each of the virtual functions in this
8058 vtable. For example:
8060 class A { virtual void f (); };
8061 class B1 : virtual public A { virtual void f (); };
8062 class B2 : virtual public A { virtual void f (); };
8063 class C: public B1, public B2 { virtual void f (); };
8065 A C object has a primary base of B1, which has a primary base of A. A
8066 C also has a secondary base of B2, which no longer has a primary base
8067 of A. So the B2-in-C construction vtable needs a secondary vtable for
8068 A, which will adjust the A* to a B2* to call f. We have no way of
8069 knowing what (or even whether) this offset will be when we define B2,
8070 so we store this "vcall offset" in the A sub-vtable and look it up in
8071 a "virtual thunk" for B2::f.
8073 We need entries for all the functions in our primary vtable and
8074 in our non-virtual bases' secondary vtables. */
8076 /* If we are just computing the vcall indices -- but do not need
8077 the actual entries -- not that. */
8080 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8082 }
8083 }
8085 /* Build vcall offsets, starting with those for BINFO. */
8087 static void
8089 {
8091 tree primary_binfo;
8092 tree base_binfo;
8094 /* Don't walk into virtual bases -- except, of course, for the
8095 virtual base for which we are building vcall offsets. Any
8096 primary virtual base will have already had its offsets generated
8097 through the recursion in build_vcall_and_vbase_vtbl_entries. */
8101 /* If BINFO has a primary base, process it first. */
8106 /* Add BINFO itself to the list. */
8109 /* Scan the non-primary bases of BINFO. */
8113 }
8115 /* Called from build_vcall_offset_vtbl_entries_r. */
8117 static void
8119 {
8120 /* Make entries for the rest of the virtuals. */
8122 {
8123 tree orig_fn;
8125 /* The ABI requires that the methods be processed in declaration
8126 order. G++ 3.2 used the order in the vtable. */
8128 orig_fn;
8132 }
8133 else
8134 {
8135 tree derived_virtuals;
8136 tree base_virtuals;
8137 tree orig_virtuals;
8138 /* If BINFO is a primary base, the most derived class which has
8139 BINFO as a primary base; otherwise, just BINFO. */
8140 tree non_primary_binfo;
8142 /* We might be a primary base class. Go up the inheritance hierarchy
8143 until we find the most derived class of which we are a primary base:
8144 it is the BINFO_VIRTUALS there that we need to consider. */
8147 {
8148 tree b;
8150 /* If we have reached a virtual base, then it must be vid->vbase,
8151 because we ignore other virtual bases in
8152 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
8153 base (possibly multi-level) of vid->binfo, or we wouldn't
8154 have called build_vcall_and_vbase_vtbl_entries for it. But it
8155 might be a lost primary, so just skip down to vid->binfo. */
8157 {
8161 }
8167 }
8170 /* For a ctor vtable we need the equivalent binfo within the hierarchy
8171 where rtti_binfo is the most derived type. */
8172 non_primary_binfo
8178 base_virtuals;
8182 {
8183 tree orig_fn;
8185 /* Find the declaration that originally caused this function to
8186 be present in BINFO_TYPE (binfo). */
8189 /* When processing BINFO, we only want to generate vcall slots for
8190 function slots introduced in BINFO. So don't try to generate
8191 one if the function isn't even defined in BINFO. */
8196 }
8197 }
8198 }
8200 /* Add a vcall offset entry for ORIG_FN to the vtable. */
8202 static void
8204 {
8206 tree vcall_offset;
8207 tree derived_entry;
8209 /* If there is already an entry for a function with the same
8210 signature as FN, then we do not need a second vcall offset.
8211 Check the list of functions already present in the derived
8212 class vtable. */
8214 {
8216 /* We only use one vcall offset for virtual destructors,
8217 even though there are two virtual table entries. */
8221 }
8223 /* If we are building these vcall offsets as part of building
8224 the vtable for the most derived class, remember the vcall
8225 offset. */
8227 {
8230 NULL);
8233 }
8235 /* The next vcall offset will be found at a more negative
8236 offset. */
8240 /* Keep track of this function. */
8244 {
8245 tree base;
8246 tree fn;
8248 /* Find the overriding function. */
8252 integer_zero_node);
8253 else
8254 {
8257 /* The vbase we're working on is a primary base of
8258 vid->binfo. But it might be a lost primary, so its
8259 BINFO_OFFSET might be wrong, so we just use the
8260 BINFO_OFFSET from vid->binfo. */
8266 vcall_offset);
8267 }
8268 /* Add the initializer to the vtable. */
8270 }
8271 }
8273 /* Return vtbl initializers for the RTTI entries corresponding to the
8274 BINFO's vtable. The RTTI entries should indicate the object given
8275 by VID->rtti_binfo. */
8277 static void
8279 {
8280 tree b;
8281 tree t;
8282 tree offset;
8283 tree decl;
8284 tree init;
8288 /* To find the complete object, we will first convert to our most
8289 primary base, and then add the offset in the vtbl to that value. */
8293 {
8294 tree primary_base;
8300 }
8304 /* The second entry is the address of the typeinfo object. */
8307 else
8310 /* Convert the declaration to a type that can be stored in the
8311 vtable. */
8315 /* Add the offset-to-top entry. It comes earlier in the vtable than
8316 the typeinfo entry. Convert the offset to look like a
8317 function pointer, so that we can put it in the vtable. */
8320 }
8322 /* Fold a OBJ_TYPE_REF expression to the address of a function.
8323 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
8325 tree
8327 {
8331 tree fndecl;
8334 {
8335 i += (TARGET_VTABLE_USES_DESCRIPTORS
8338 }
8342 #ifdef ENABLE_CHECKING
8345 #endif
8350 }