| blob | d29d6615f331552c1f502040ba84b0c242ed5923 |
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
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. */
80 tree inits;
81 /* The last (i.e., most negative) entry in INITS. */
83 /* The binfo for the virtual base for which we're building
84 vcall offset initializers. */
85 tree vbase;
86 /* The functions in vbase for which we have already provided vcall
87 offsets. */
89 /* The vtable index of the next vcall or vbase offset. */
90 tree index;
91 /* Nonzero if we are building the initializer for the primary
92 vtable. */
94 /* Nonzero if we are building the initializer for a construction
95 vtable. */
97 /* True when adding vcall offset entries to the vtable. False when
98 merely computing the indices. */
102 /* The type of a function passed to walk_subobject_offsets. */
105 /* The stack itself. This is a dynamically resized array. The
106 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
110 /* The size of the largest empty class seen in this translation unit. */
113 /* An array of all local classes present in this translation unit, in
114 declaration order. */
183 tree);
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. */
291 /* Do we need to look in the vtable for the real offset? */
294 /* Don't bother with the calculations inside sizeof; they'll ICE if the
295 source type is incomplete and the pointer value doesn't matter. */
297 {
302 }
304 /* Do we need to check for a null pointer? */
306 {
307 /* If we know the conversion will not actually change the value
308 of EXPR, then we can avoid testing the expression for NULL.
309 We have to avoid generating a COMPONENT_REF for a base class
310 field, because other parts of the compiler know that such
311 expressions are always non-NULL. */
313 {
314 tree class_type;
315 /* TARGET_TYPE has been extracted from BINFO, and, is
316 therefore always cv-unqualified. Extract the
317 cv-qualifiers from EXPR so that the expression returned
318 matches the input. */
320 target_type
324 }
326 }
328 /* Protect against multiple evaluation if necessary. */
332 /* Now that we've saved expr, build the real null test. */
334 {
338 }
340 /* If this is a simple base reference, express it as a COMPONENT_REF. */
342 /* We don't build base fields for empty bases, and they aren't very
343 interesting to the optimizers anyway. */
345 {
352 }
355 {
356 /* Going via virtual base V_BINFO. We need the static offset
357 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
358 V_BINFO. That offset is an entry in D_BINFO's vtable. */
359 tree v_offset;
362 {
363 /* In a base member initializer, we cannot rely on the
364 vtable being set up. We have to indirect via the
365 vtt_parm. */
366 tree t;
372 tf_warning_or_error);
373 }
374 else
376 tf_warning_or_error),
383 v_offset);
395 /* Negative fixed_type_p means this is a constructor or destructor;
396 virtual base layout is fixed in in-charge [cd]tors, but not in
397 base [cd]tors. */
401 v_offset,
404 else
406 }
408 target_type = cp_build_qualified_type
417 {
422 }
423 else
429 out:
433 integer_zero_node));
436 }
438 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
439 Perform a derived-to-base conversion by recursively building up a
440 sequence of COMPONENT_REFs to the appropriate base fields. */
442 static tree
444 {
447 tree field;
450 {
451 tree temp;
455 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
456 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
457 an lvalue in the front end; only _DECLs and _REFs are lvalues
458 in the back end. */
464 }
466 /* Recurse. */
471 /* Is this the base field created by build_base_field? */
475 {
476 /* We don't use build_class_member_access_expr here, as that
477 has unnecessary checks, and more importantly results in
478 recursive calls to dfs_walk_once. */
486 /* Mark the expression const or volatile, as appropriate.
487 Even though we've dealt with the type above, we still have
488 to mark the expression itself. */
495 }
497 /* Didn't find the base field?!? */
499 }
501 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
502 type is a class type or a pointer to a class type. In the former
503 case, TYPE is also a class type; in the latter it is another
504 pointer type. If CHECK_ACCESS is true, an error message is emitted
505 if TYPE is inaccessible. If OBJECT has pointer type, the value is
506 assumed to be non-NULL. */
508 tree
510 {
511 tree binfo;
512 tree object_type;
515 {
518 }
519 else
524 NULL);
529 }
531 /* EXPR is an expression with unqualified class type. BASE is a base
532 binfo of that class type. Returns EXPR, converted to the BASE
533 type. This function assumes that EXPR is the most derived class;
534 therefore virtual bases can be found at their static offsets. */
536 tree
538 {
539 tree expr_type;
543 {
544 tree pointer_type;
548 /* We use fold_build2 and fold_convert below to simplify the trees
549 provided to the optimizers. It is not safe to call these functions
550 when processing a template because they do not handle C++-specific
551 trees. */
554 tf_warning_or_error);
561 }
564 }
566 \f
567 tree
569 {
575 /* First, convert to the requested type. */
580 /* Second, the requested type may not be the owner of its own vptr.
581 If not, convert to the base class that owns it. We cannot use
582 convert_to_base here, because VCONTEXT may appear more than once
583 in the inheritance hierarchy of TYPE, and thus direct conversion
584 between the types may be ambiguous. Following the path back up
585 one step at a time via primary bases avoids the problem. */
589 {
592 }
595 }
597 /* Given an object INSTANCE, return an expression which yields the
598 vtable element corresponding to INDEX. There are many special
599 cases for INSTANCE which we take care of here, mainly to avoid
600 creating extra tree nodes when we don't have to. */
602 static tree
604 {
605 tree aref;
608 /* Try to figure out what a reference refers to, and
609 access its virtual function table directly. */
617 {
622 }
631 }
633 tree
635 {
639 }
641 /* Given a stable object pointer INSTANCE_PTR, return an expression which
642 yields a function pointer corresponding to vtable element INDEX. */
644 tree
646 {
647 tree aref;
650 tf_warning_or_error),
651 idx);
653 /* When using function descriptors, the address of the
654 vtable entry is treated as a function pointer. */
658 tf_warning_or_error));
660 /* Remember this as a method reference, for later devirtualization. */
664 }
666 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
667 for the given TYPE. */
669 static tree
671 {
673 }
675 /* DECL is an entity associated with TYPE, like a virtual table or an
676 implicitly generated constructor. Determine whether or not DECL
677 should have external or internal linkage at the object file
678 level. This routine does not deal with COMDAT linkage and other
679 similar complexities; it simply sets TREE_PUBLIC if it possible for
680 entities in other translation units to contain copies of DECL, in
681 the abstract. */
683 void
685 {
686 /* If TYPE involves a local class in a function with internal
687 linkage, then DECL should have internal linkage too. Other local
688 classes have no linkage -- but if their containing functions
689 have external linkage, it makes sense for DECL to have external
690 linkage too. That will allow template definitions to be merged,
691 for example. */
693 {
696 }
697 else
699 }
701 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
702 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
703 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
705 static tree
707 {
708 tree decl;
711 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
712 now to avoid confusion in mangle_decl. */
721 /* At one time the vtable info was grabbed 2 words at a time. This
722 fails on sparc unless you have 8-byte alignment. (tiemann) */
726 /* The vtable has not been defined -- yet. */
730 /* Mark the VAR_DECL node representing the vtable itself as a
731 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
732 is rather important that such things be ignored because any
733 effort to actually generate DWARF for them will run into
734 trouble when/if we encounter code like:
736 #pragma interface
737 struct S { virtual void member (); };
739 because the artificial declaration of the vtable itself (as
740 manufactured by the g++ front end) will say that the vtable is
741 a static member of `S' but only *after* the debug output for
742 the definition of `S' has already been output. This causes
743 grief because the DWARF entry for the definition of the vtable
744 will try to refer back to an earlier *declaration* of the
745 vtable as a static member of `S' and there won't be one. We
746 might be able to arrange to have the "vtable static member"
747 attached to the member list for `S' before the debug info for
748 `S' get written (which would solve the problem) but that would
749 require more intrusive changes to the g++ front end. */
753 }
755 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
756 or even complete. If this does not exist, create it. If COMPLETE is
757 nonzero, then complete the definition of it -- that will render it
758 impossible to actually build the vtable, but is useful to get at those
759 which are known to exist in the runtime. */
761 tree
763 {
764 tree decl;
773 {
776 }
779 }
781 /* Build the primary virtual function table for TYPE. If BINFO is
782 non-NULL, build the vtable starting with the initial approximation
783 that it is the same as the one which is the head of the association
784 list. Returns a nonzero value if a new vtable is actually
785 created. */
787 static int
789 {
790 tree decl;
791 tree virtuals;
796 {
798 /* We have already created a vtable for this base, so there's
799 no need to do it again. */
806 }
807 else
808 {
811 }
813 #ifdef GATHER_STATISTICS
816 #endif
818 /* Initialize the association list for this type, based
819 on our first approximation. */
824 }
826 /* Give BINFO a new virtual function table which is initialized
827 with a skeleton-copy of its original initialization. The only
828 entry that changes is the `delta' entry, so we can really
829 share a lot of structure.
831 FOR_TYPE is the most derived type which caused this table to
832 be needed.
834 Returns nonzero if we haven't met BINFO before.
836 The order in which vtables are built (by calling this function) for
837 an object must remain the same, otherwise a binary incompatibility
838 can result. */
840 static int
842 {
844 /* We already created a vtable for this base. There's no need to
845 do it again. */
848 /* Remember that we've created a vtable for this BINFO, so that we
849 don't try to do so again. */
852 /* Make fresh virtual list, so we can smash it later. */
855 /* Secondary vtables are laid out as part of the same structure as
856 the primary vtable. */
859 }
861 /* Create a new vtable for BINFO which is the hierarchy dominated by
862 T. Return nonzero if we actually created a new vtable. */
864 static int
866 {
868 /* In this case, it is *type*'s vtable we are modifying. We start
869 with the approximation that its vtable is that of the
870 immediate base class. */
872 else
873 /* This is our very own copy of `basetype' to play with. Later,
874 we will fill in all the virtual functions that override the
875 virtual functions in these base classes which are not defined
876 by the current type. */
878 }
880 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
881 (which is in the hierarchy dominated by T) list FNDECL as its
882 BV_FN. DELTA is the required constant adjustment from the `this'
883 pointer where the vtable entry appears to the `this' required when
884 the function is actually called. */
886 static void
888 tree binfo,
889 tree fndecl,
890 tree delta,
892 {
893 tree v;
899 {
900 /* We need a new vtable for BINFO. */
902 {
903 /* If we really did make a new vtable, we also made a copy
904 of the BINFO_VIRTUALS list. Now, we have to find the
905 corresponding entry in that list. */
910 }
915 }
916 }
918 \f
919 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
920 the USING_DECL naming METHOD. Returns true if the method could be
921 added to the method vec. */
923 bool
925 {
927 tree overload;
933 tree current_fns;
934 tree fns;
947 {
948 /* Make a new method vector. We start with 8 entries. We must
949 allocate at least two (for constructors and destructors), and
950 we're going to end up with an assignment operator at some
951 point as well. */
953 /* Create slots for constructors and destructors. */
957 }
959 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
962 /* Constructors and destructors go in special slots. */
966 {
970 {
976 type);
977 }
978 }
979 else
980 {
981 tree m;
984 /* See if we already have an entry with this name. */
988 {
991 {
996 }
1000 {
1003 }
1008 }
1009 }
1012 /* Check to see if we've already got this method. */
1014 {
1016 tree fn_type;
1017 tree method_type;
1018 tree parms1;
1019 tree parms2;
1024 /* [over.load] Member function declarations with the
1025 same name and the same parameter types cannot be
1026 overloaded if any of them is a static member
1027 function declaration.
1029 [namespace.udecl] When a using-declaration brings names
1030 from a base class into a derived class scope, member
1031 functions in the derived class override and/or hide member
1032 functions with the same name and parameter types in a base
1033 class (rather than conflicting). */
1039 /* Compare the quals on the 'this' parm. Don't compare
1040 the whole types, as used functions are treated as
1041 coming from the using class in overload resolution. */
1050 /* For templates, the return type and template parameters
1051 must be identical. */
1068 {
1070 {
1072 /* Defer to the local function. */
1076 else
1078 using_decl);
1079 }
1080 else
1081 {
1084 }
1086 /* We don't call duplicate_decls here to merge the
1087 declarations because that will confuse things if the
1088 methods have inline definitions. In particular, we
1089 will crash while processing the definitions. */
1091 }
1092 }
1094 /* A class should never have more than one destructor. */
1098 /* Add the new binding. */
1107 {
1110 /* We only expect to add few methods in the COMPLETE_P case, so
1111 just make room for one more method in that case. */
1114 else
1120 else
1122 }
1123 else
1124 /* Replace the current slot. */
1127 }
1129 /* Subroutines of finish_struct. */
1131 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1132 legit, otherwise return 0. */
1134 static int
1136 {
1137 tree elem;
1146 {
1148 {
1152 else
1155 }
1156 else
1157 {
1158 /* They're changing the access to the same thing they changed
1159 it to before. That's OK. */
1160 ;
1161 }
1162 }
1163 else
1164 {
1168 }
1170 }
1172 /* Process the USING_DECL, which is a member of T. */
1174 static void
1176 {
1179 tree access
1184 tree old_value;
1190 {
1196 else
1198 }
1206 ;
1208 {
1210 /* It's OK to use functions from a base when there are functions with
1212 else
1213 {
1218 }
1219 }
1221 {
1225 }
1227 /* Make type T see field decl FDECL with access ACCESS. */
1230 {
1233 }
1234 else
1236 }
1237 \f
1238 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1239 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1240 properties of the bases. */
1242 static void
1246 {
1249 tree base_binfo;
1250 tree binfo;
1262 {
1267 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1268 here because the case of virtual functions but non-virtual
1269 dtor is handled in finish_struct_1. */
1274 /* If the base class doesn't have copy constructors or
1275 assignment operators that take const references, then the
1276 derived class cannot have such a member automatically
1277 generated. */
1285 /* A virtual base does not effect nearly emptiness. */
1286 ;
1288 {
1290 /* And if there is more than one nearly empty base, then the
1291 derived class is not nearly empty either. */
1293 else
1294 /* Remember we've seen one. */
1296 }
1298 /* If the base class is not empty or nearly empty, then this
1299 class cannot be nearly empty. */
1302 /* A lot of properties from the bases also apply to the derived
1303 class. */
1315 /* A standard-layout class is a class that:
1316 ...
1317 * has no non-standard-layout base classes, */
1320 {
1321 tree basefield;
1322 /* ...has no base classes of the same type as the first non-static
1323 data member... */
1325 && (same_type_ignoring_top_level_qualifiers_p
1328 else
1329 /* ...either has no non-static data members in the most-derived
1330 class and at most one base class with non-static data
1331 members, or has no base classes with non-static data
1332 members */
1336 {
1339 else
1342 }
1343 }
1344 }
1345 }
1347 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1348 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1349 that have had a nearly-empty virtual primary base stolen by some
1350 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1351 T. */
1353 static void
1355 {
1359 tree base_binfo;
1361 /* Determine the primary bases of our bases. */
1364 {
1367 /* See if we're the non-virtual primary of our inheritance
1368 chain. */
1370 {
1377 /* We are the primary binfo. */
1379 }
1380 /* Determine if we have a virtual primary base, and mark it so.
1381 */
1383 {
1387 /* Someone already claimed this base. */
1389 else
1390 {
1391 tree delta;
1396 /* A virtual binfo might have been copied from within
1397 another hierarchy. As we're about to use it as a
1398 primary base, make sure the offsets match. */
1406 }
1407 }
1408 }
1410 /* First look for a dynamic direct non-virtual base. */
1412 {
1416 {
1419 }
1420 }
1422 /* A "nearly-empty" virtual base class can be the primary base
1423 class, if no non-virtual polymorphic base can be found. Look for
1424 a nearly-empty virtual dynamic base that is not already a primary
1425 base of something in the hierarchy. If there is no such base,
1426 just pick the first nearly-empty virtual base. */
1432 {
1434 {
1435 /* Found one that is not primary. */
1438 }
1440 /* Remember the first candidate. */
1442 }
1444 found:
1445 /* If we've got a primary base, use it. */
1447 {
1452 /* We are stealing a primary base. */
1456 {
1457 tree delta;
1460 /* A virtual binfo might have been copied from within
1461 another hierarchy. As we're about to use it as a primary
1462 base, make sure the offsets match. */
1467 }
1474 }
1475 }
1477 /* Update the variant types of T. */
1479 void
1481 {
1482 tree variants;
1488 variants;
1490 {
1491 /* These fields are in the _TYPE part of the node, not in
1492 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1502 /* Copy whatever these are holding today. */
1507 /* All variants of a class have the same attributes. */
1509 }
1510 }
1512 \f
1513 /* Set memoizing fields and bits of T (and its variants) for later
1514 use. */
1516 static void
1518 {
1519 /* Fix up variants (if any). */
1523 /* For a class w/o baseclasses, 'finish_struct' has set
1524 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1525 Similarly for a class whose base classes do not have vtables.
1526 When neither of these is true, we might have removed abstract
1527 virtuals (by providing a definition), added some (by declaring
1528 new ones), or redeclared ones from a base class. We need to
1529 recalculate what's really an abstract virtual at this point (by
1530 looking in the vtables). */
1533 /* If this type has a copy constructor or a destructor, force its
1534 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1535 nonzero. This will cause it to be passed by invisible reference
1536 and prevent it from being returned in a register. */
1538 {
1539 tree variants;
1542 {
1545 }
1546 }
1547 }
1549 /* Issue warnings about T having private constructors, but no friends,
1550 and so forth.
1552 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1553 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1554 non-private static member functions. */
1556 static void
1558 {
1561 tree fn;
1564 /* If the class has friends, those entities might create and
1565 access instances, so we should not warn. */
1568 /* We will have warned when the template was declared; there's
1569 no need to warn on every instantiation. */
1571 /* There's no reason to even consider warning about this
1572 class. */
1575 /* We only issue one warning, if more than one applies, because
1576 otherwise, on code like:
1578 class A {
1579 // Oops - forgot `public:'
1580 A();
1581 A(const A&);
1582 ~A();
1583 };
1585 we warn several times about essentially the same problem. */
1587 /* Check to see if all (non-constructor, non-destructor) member
1588 functions are private. (Since there are no friends or
1589 non-private statics, we can't ever call any of the private member
1590 functions.) */
1592 /* We're not interested in compiler-generated methods; they don't
1593 provide any way to call private members. */
1595 {
1597 {
1599 /* A non-private static member function is just like a
1600 friend; it can create and invoke private member
1601 functions, and be accessed without a class
1602 instance. */
1606 /* Keep searching for a static member function. */
1607 }
1610 }
1613 {
1614 /* There are no non-private methods, and there's at least one
1615 private member function that isn't a constructor or
1616 destructor. (If all the private members are
1617 constructors/destructors we want to use the code below that
1618 issues error messages specifically referring to
1619 constructors/destructors.) */
1625 {
1628 }
1630 {
1634 }
1635 }
1637 /* Even if some of the member functions are non-private, the class
1638 won't be useful for much if all the constructors or destructors
1639 are private: such an object can never be created or destroyed. */
1642 {
1645 t);
1647 }
1649 /* Warn about classes that have private constructors and no friends. */
1651 /* Implicitly generated constructors are always public. */
1654 {
1657 /* If a non-template class does not define a copy
1658 constructor, one is defined for it, enabling it to avoid
1659 this warning. For a template class, this does not
1660 happen, and so we would normally get a warning on:
1662 template <class T> class C { private: C(); };
1664 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1665 complete non-template or fully instantiated classes have this
1666 flag set. */
1669 else
1671 {
1673 /* Ideally, we wouldn't count copy constructors (or, in
1674 fact, any constructor that takes an argument of the
1675 class type as a parameter) because such things cannot
1676 be used to construct an instance of the class unless
1677 you already have one. But, for now at least, we're
1678 more generous. */
1680 {
1683 }
1684 }
1687 {
1690 t);
1692 }
1693 }
1694 }
1697 gt_pointer_operator new_value;
1701 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1703 static int
1705 {
1718 }
1720 /* This routine compares two fields like method_name_cmp but using the
1721 pointer operator in resort_field_decl_data. */
1723 static int
1725 {
1734 {
1741 }
1743 }
1745 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1747 void
1750 gt_pointer_operator new_value,
1752 {
1756 tree fn;
1758 /* The type conversion ops have to live at the front of the vec, so we
1759 can't sort them. */
1767 {
1771 resort_method_name_cmp);
1772 }
1773 }
1775 /* Warn about duplicate methods in fn_fields.
1777 Sort methods that are not special (i.e., constructors, destructors,
1778 and type conversion operators) so that we can find them faster in
1779 search. */
1781 static void
1783 {
1784 tree fn_fields;
1794 /* Clear DECL_IN_AGGR_P for all functions. */
1799 /* Issue warnings about private constructors and such. If there are
1800 no methods, then some public defaults are generated. */
1803 /* The type conversion ops have to live at the front of the vec, so we
1804 can't sort them. */
1813 }
1815 /* Make BINFO's vtable have N entries, including RTTI entries,
1816 vbase and vcall offsets, etc. Set its type and call the back end
1817 to lay it out. */
1819 static void
1821 {
1822 tree atype;
1823 tree vtable;
1829 /* We may have to grow the vtable. */
1832 {
1836 }
1837 }
1839 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1840 have the same signature. */
1842 int
1844 {
1845 /* One destructor overrides another if they are the same kind of
1846 destructor. */
1850 /* But a non-destructor never overrides a destructor, nor vice
1851 versa, nor do different kinds of destructors override
1852 one-another. For example, a complete object destructor does not
1853 override a deleting destructor. */
1862 {
1870 }
1872 }
1874 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1875 subobject. */
1877 static bool
1879 {
1880 tree probe;
1883 {
1887 /* If we meet a virtual base, we can't follow the inheritance
1888 any more. See if the complete type of DERIVED contains
1889 such a virtual base. */
1892 }
1894 }
1897 /* The function for which we are trying to find a final overrider. */
1898 tree fn;
1899 /* The base class in which the function was declared. */
1900 tree declaring_base;
1901 /* The candidate overriders. */
1902 tree candidates;
1903 /* Path to most derived. */
1907 /* Add the overrider along the current path to FFOD->CANDIDATES.
1908 Returns true if an overrider was found; false otherwise. */
1910 static bool
1914 {
1915 tree method;
1917 /* If BINFO is not the most derived type, try a more derived class.
1918 A definition there will overrider a definition here. */
1920 {
1921 depth--;
1925 }
1929 {
1932 /* Remove any candidates overridden by this new function. */
1934 {
1935 /* If *CANDIDATE overrides METHOD, then METHOD
1936 cannot override anything else on the list. */
1939 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1942 else
1944 }
1946 /* Add the new function. */
1949 }
1952 }
1954 /* Called from find_final_overrider via dfs_walk. */
1956 static tree
1958 {
1966 }
1968 static tree
1970 {
1975 }
1977 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1978 FN and whose TREE_VALUE is the binfo for the base where the
1979 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1980 DERIVED) is the base object in which FN is declared. */
1982 static tree
1984 {
1985 find_final_overrider_data ffod;
1987 /* Getting this right is a little tricky. This is valid:
1989 struct S { virtual void f (); };
1990 struct T { virtual void f (); };
1991 struct U : public S, public T { };
1993 even though calling `f' in `U' is ambiguous. But,
1995 struct R { virtual void f(); };
1996 struct S : virtual public R { virtual void f (); };
1997 struct T : virtual public R { virtual void f (); };
1998 struct U : public S, public T { };
2000 is not -- there's no way to decide whether to put `S::f' or
2001 `T::f' in the vtable for `R'.
2003 The solution is to look at all paths to BINFO. If we find
2004 different overriders along any two, then there is a problem. */
2008 /* Determine the depth of the hierarchy. */
2019 /* If there was no winner, issue an error message. */
2024 }
2026 /* Return the index of the vcall offset for FN when TYPE is used as a
2027 virtual base. */
2029 static tree
2031 {
2033 tree_pair_p p;
2041 /* There should always be an appropriate index. */
2043 }
2045 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2046 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2047 corresponding position in the BINFO_VIRTUALS list. */
2049 static void
2052 {
2053 tree b;
2054 tree overrider;
2055 tree delta;
2056 tree virtual_base;
2057 tree first_defn;
2063 /* Find the nearest primary base (possibly binfo itself) which defines
2064 this function; this is the class the caller will convert to when
2065 calling FN through BINFO. */
2067 {
2072 /* The nearest definition is from a lost primary. */
2075 }
2078 /* Find the final overrider. */
2081 {
2084 }
2087 /* Check for adjusting covariant return types. */
2095 /* If the overrider is invalid, don't even try. */
2097 {
2098 /* If FN is a covariant thunk, we must figure out the adjustment
2099 to the final base FN was converting to. As OVERRIDER_TARGET might
2100 also be converting to the return type of FN, we have to
2101 combine the two conversions here. */
2108 {
2112 }
2113 else
2117 /* Find the equivalent binfo within the return type of the
2118 overriding function. We will want the vbase offset from
2119 there. */
2121 over_return);
2124 {
2125 /* There was no existing virtual thunk (which takes
2126 precedence). So find the binfo of the base function's
2127 return type within the overriding function's return type.
2128 We cannot call lookup base here, because we're inside a
2129 dfs_walk, and will therefore clobber the BINFO_MARKED
2130 flags. Fortunately we know the covariancy is valid (it
2131 has already been checked), so we can just iterate along
2132 the binfos, which have been chained in inheritance graph
2133 order. Of course it is lame that we have to repeat the
2134 search here anyway -- we should really be caching pieces
2135 of the vtable and avoiding this repeated work. */
2138 /* Find the base binfo within the overriding function's
2139 return type. We will always find a thunk_binfo, except
2140 when the covariancy is invalid (which we will have
2141 already diagnosed). */
2144 thunk_binfo;
2150 /* See if virtual inheritance is involved. */
2152 virtual_offset;
2159 {
2163 {
2164 /* We convert via virtual base. Adjust the fixed
2165 offset to be from there. */
2166 offset =
2170 }
2172 /* There was an existing fixed offset, this must be
2173 from the base just converted to, and the base the
2174 FN was thunking to. */
2176 else
2178 }
2179 }
2182 /* Replace the overriding function with a covariant thunk. We
2183 will emit the overriding function in its own slot as
2184 well. */
2187 }
2188 else
2192 /* Assume that we will produce a thunk that convert all the way to
2193 the final overrider, and not to an intermediate virtual base. */
2196 /* See if we can convert to an intermediate virtual base first, and then
2197 use the vcall offset located there to finish the conversion. */
2199 {
2200 /* If we find the final overrider, then we can stop
2201 walking. */
2206 /* If we find a virtual base, and we haven't yet found the
2207 overrider, then there is a virtual base between the
2208 declaring base (first_defn) and the final overrider. */
2210 {
2213 }
2214 }
2217 {
2218 /* The ABI specifies that a covariant thunk includes a mangling
2219 for a this pointer adjustment. This-adjusting thunks that
2220 override a function from a virtual base have a vcall
2221 adjustment. When the virtual base in question is a primary
2222 virtual base, we know the adjustments are zero, (and in the
2223 non-covariant case, we would not use the thunk).
2224 Unfortunately we didn't notice this could happen, when
2225 designing the ABI and so never mandated that such a covariant
2226 thunk should be emitted. Because we must use the ABI mandated
2227 name, we must continue searching from the binfo where we
2228 found the most recent definition of the function, towards the
2229 primary binfo which first introduced the function into the
2230 vtable. If that enters a virtual base, we must use a vcall
2231 this-adjusting thunk. Bleah! */
2240 /* Even if we find a virtual base, the correct delta is
2241 between the overrider and the binfo we're building a vtable
2242 for. */
2244 }
2246 /* Compute the constant adjustment to the `this' pointer. The
2247 `this' pointer, when this function is called, will point at BINFO
2248 (or one of its primary bases, which are at the same offset). */
2250 /* The `this' pointer needs to be adjusted from the declaration to
2251 the nearest virtual base. */
2256 /* If the nearest definition is in a lost primary, we don't need an
2257 entry in our vtable. Except possibly in a constructor vtable,
2258 if we happen to get our primary back. In that case, the offset
2259 will be zero, as it will be a primary base. */
2261 else
2262 /* The `this' pointer needs to be adjusted from pointing to
2263 BINFO to pointing at the base where the final overrider
2264 appears. */
2265 virtual_covariant:
2276 else
2278 }
2280 /* Called from modify_all_vtables via dfs_walk. */
2282 static tree
2284 {
2286 tree virtuals;
2287 tree old_virtuals;
2291 /* A base without a vtable needs no modification, and its bases
2292 are uninteresting. */
2297 /* Don't do the primary vtable, if it's new. */
2301 /* There's no need to modify the vtable for a non-virtual primary
2302 base; we're not going to use that vtable anyhow. We do still
2303 need to do this for virtual primary bases, as they could become
2304 non-primary in a construction vtable. */
2309 /* Now, go through each of the virtual functions in the virtual
2310 function table for BINFO. Find the final overrider, and update
2311 the BINFO_VIRTUALS list appropriately. */
2314 virtuals;
2318 binfo,
2323 }
2325 /* Update all of the primary and secondary vtables for T. Create new
2326 vtables as required, and initialize their RTTI information. Each
2327 of the functions in VIRTUALS is declared in T and may override a
2328 virtual function from a base class; find and modify the appropriate
2329 entries to point to the overriding functions. Returns a list, in
2330 declaration order, of the virtual functions that are declared in T,
2331 but do not appear in the primary base class vtable, and which
2332 should therefore be appended to the end of the vtable for T. */
2334 static tree
2336 {
2340 /* Update all of the vtables. */
2343 /* Add virtual functions not already in our primary vtable. These
2344 will be both those introduced by this class, and those overridden
2345 from secondary bases. It does not include virtuals merely
2346 inherited from secondary bases. */
2348 {
2353 {
2354 /* We don't need to adjust the `this' pointer when
2355 calling this function. */
2359 /* This is a function not already in our vtable. Keep it. */
2361 }
2362 else
2363 /* We've already got an entry for this function. Skip it. */
2365 }
2368 }
2370 /* Get the base virtual function declarations in T that have the
2371 indicated NAME. */
2373 static tree
2375 {
2376 tree methods;
2381 /* Find virtual functions in T with the indicated NAME. */
2385 methods;
2387 {
2393 }
2399 {
2402 base_fndecls);
2403 }
2406 }
2408 /* If this declaration supersedes the declaration of
2409 a method declared virtual in the base class, then
2410 mark this field as being virtual as well. */
2412 void
2414 {
2416 /* In [temp.mem] we have:
2418 A specialization of a member function template does not
2419 override a virtual function from a base class. */
2426 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2427 the error_mark_node so that we know it is an overriding
2428 function. */
2432 {
2436 }
2437 }
2439 /* Warn about hidden virtual functions that are not overridden in t.
2440 We know that constructors and destructors don't apply. */
2442 static void
2444 {
2446 tree fns;
2449 /* We go through each separately named virtual function. */
2453 {
2454 tree fn;
2455 tree name;
2456 tree fndecl;
2457 tree base_fndecls;
2458 tree base_binfo;
2459 tree binfo;
2462 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2463 have the same name. Figure out what name that is. */
2465 /* There are no possibly hidden functions yet. */
2467 /* Iterate through all of the base classes looking for possibly
2468 hidden functions. */
2471 {
2474 base_fndecls);
2475 }
2477 /* If there are no functions to hide, continue. */
2481 /* Remove any overridden functions. */
2483 {
2486 {
2490 /* If the method from the base class has the same
2491 signature as the method from the derived class, it
2492 has been overridden. */
2495 else
2497 }
2498 }
2500 /* Now give a warning for all base functions without overriders,
2501 as they are hidden. */
2503 {
2504 /* Here we know it is a hider, and no overrider exists. */
2508 }
2509 }
2510 }
2512 /* Check for things that are invalid. There are probably plenty of other
2513 things we should check for also. */
2515 static void
2517 {
2518 tree field;
2521 {
2529 {
2533 {
2534 /* We're generally only interested in entities the user
2535 declared, but we also find nested classes by noticing
2536 the TYPE_DECL that we create implicitly. You're
2537 allowed to put one anonymous union inside another,
2538 though, so we explicitly tolerate that. We use
2539 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2540 we also allow unnamed types used for defining fields. */
2547 {
2551 else
2555 }
2558 {
2561 else
2563 }
2565 {
2568 else
2570 }
2574 }
2575 }
2576 }
2577 }
2579 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2580 will be used later during class template instantiation.
2581 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2582 a non-static member data (FIELD_DECL), a member function
2583 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2584 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2585 When FRIEND_P is nonzero, T is either a friend class
2586 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2587 (FUNCTION_DECL, TEMPLATE_DECL). */
2589 void
2591 {
2592 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2597 }
2599 /* Create default constructors, assignment operators, and so forth for
2600 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2601 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2602 the class cannot have a default constructor, copy constructor
2603 taking a const reference argument, or an assignment operator taking
2604 a const reference, respectively. */
2606 static void
2610 {
2611 /* Destructor. */
2613 {
2614 /* In general, we create destructors lazily. */
2616 /* However, if the implicit destructor is non-trivial
2617 destructor, we sometimes have to create it at this point. */
2619 {
2623 /* If this a Java class, any non-trivial destructor is
2624 invalid, even if compiler-generated. Therefore, if the
2625 destructor is non-trivial we create it now. */
2627 else
2628 {
2629 tree binfo;
2630 tree base_binfo;
2633 /* If the implicit destructor will be virtual, then we must
2634 generate it now because (unfortunately) we do not
2635 generate virtual tables lazily. */
2638 {
2639 tree base_type;
2640 tree dtor;
2645 {
2648 }
2649 }
2650 }
2652 /* If we can't get away with being lazy, generate the destructor
2653 now. */
2656 }
2657 }
2659 /* [class.ctor]
2661 If there is no user-declared constructor for a class, a default
2662 constructor is implicitly declared. */
2664 {
2667 }
2669 /* [class.ctor]
2671 If a class definition does not explicitly declare a copy
2672 constructor, one is declared implicitly. */
2674 {
2678 }
2680 /* Currently only lambdas get a lazy move ctor. */
2684 /* If there is no assignment operator, one will be created if and
2685 when it is needed. For now, just record whether or not the type
2686 of the parameter to the assignment operator will be a const or
2687 non-const reference. */
2689 {
2693 }
2694 }
2696 /* Subroutine of finish_struct_1. Recursively count the number of fields
2697 in TYPE, including anonymous union members. */
2699 static int
2701 {
2702 tree x;
2705 {
2708 else
2710 }
2712 }
2714 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2715 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2717 static int
2719 {
2720 tree x;
2722 {
2725 else
2727 }
2729 }
2731 /* FIELD is a bit-field. We are finishing the processing for its
2732 enclosing type. Issue any appropriate messages and set appropriate
2733 flags. Returns false if an error has been diagnosed. */
2735 static bool
2737 {
2739 tree w;
2741 /* Extract the declared width of the bitfield, which has been
2742 temporarily stashed in DECL_INITIAL. */
2745 /* Remove the bit-field width indicator so that the rest of the
2746 compiler does not treat that value as an initializer. */
2749 /* Detect invalid bit-field type. */
2751 {
2754 }
2755 else
2756 {
2757 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2760 /* detect invalid field size. */
2764 {
2767 }
2769 {
2772 }
2774 {
2777 }
2784 tree_int_cst_min_precision
2788 tree_int_cst_min_precision
2792 }
2795 {
2799 }
2800 else
2801 {
2802 /* Non-bit-fields are aligned for their type. */
2806 }
2807 }
2809 /* FIELD is a non bit-field. We are finishing the processing for its
2810 enclosing type T. Issue any appropriate messages and set appropriate
2811 flags. */
2813 static void
2815 tree t,
2819 {
2822 /* An anonymous union cannot contain any fields which would change
2823 the settings of CANT_HAVE_CONST_CTOR and friends. */
2825 ;
2826 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2827 structs. So, we recurse through their fields here. */
2829 {
2830 tree fields;
2836 }
2837 /* Check members with class type for constructors, destructors,
2838 etc. */
2840 {
2841 /* Never let anything with uninheritable virtuals
2842 make it through without complaint. */
2846 {
2849 field);
2854 field);
2855 }
2856 else
2857 {
2864 }
2871 }
2873 {
2874 /* `build_class_init_list' does not recognize
2875 non-FIELD_DECLs. */
2879 }
2880 }
2882 /* Check the data members (both static and non-static), class-scoped
2883 typedefs, etc., appearing in the declaration of T. Issue
2884 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2885 declaration order) of access declarations; each TREE_VALUE in this
2886 list is a USING_DECL.
2888 In addition, set the following flags:
2890 EMPTY_P
2891 The class is empty, i.e., contains no non-static data members.
2893 CANT_HAVE_CONST_CTOR_P
2894 This class cannot have an implicitly generated copy constructor
2895 taking a const reference.
2897 CANT_HAVE_CONST_ASN_REF
2898 This class cannot have an implicitly generated assignment
2899 operator taking a const reference.
2901 All of these flags should be initialized before calling this
2902 function.
2904 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2905 fields can be added by adding to this chain. */
2907 static void
2911 {
2919 /* Assume there are no access declarations. */
2921 /* Assume this class has no pointer members. */
2923 /* Assume none of the members of this class have default
2924 initializations. */
2928 {
2936 {
2937 /* Prune the access declaration from the list of fields. */
2940 /* Save the access declarations for our caller. */
2943 /* Since we've reset *FIELD there's no reason to skip to the
2944 next field. */
2947 }
2953 /* If we've gotten this far, it's a data member, possibly static,
2954 or an enumerator. */
2957 /* When this goes into scope, it will be a non-local reference. */
2961 {
2962 /* [class.union]
2964 If a union contains a static data member, or a member of
2965 reference type, the program is ill-formed. */
2967 {
2970 }
2972 {
2977 }
2978 }
2980 /* Perform error checking that did not get done in
2981 grokdeclarator. */
2983 {
2987 }
2989 {
2993 }
3001 /* Now it can only be a FIELD_DECL. */
3006 /* A standard-layout class is a class that:
3007 ...
3008 has the same access control (Clause 11) for all non-static data members,
3009 ... */
3016 /* If this is of reference type, check if it needs an init. */
3018 {
3024 /* ARM $12.6.2: [A member initializer list] (or, for an
3025 aggregate, initialization by a brace-enclosed list) is the
3026 only way to initialize nonstatic const and reference
3027 members. */
3029 }
3034 {
3036 {
3037 warning
3040 x);
3042 }
3046 }
3049 /* We don't treat zero-width bitfields as making a class
3050 non-empty. */
3051 ;
3052 else
3053 {
3054 /* The class is non-empty. */
3056 /* The class is not even nearly empty. */
3058 /* If one of the data members contains an empty class,
3059 so does T. */
3063 }
3065 /* This is used by -Weffc++ (see below). Warn only for pointers
3066 to members which might hold dynamic memory. So do not warn
3067 for pointers to functions or pointers to members. */
3074 {
3079 }
3085 /* DR 148 now allows pointers to members (which are POD themselves),
3086 to be allowed in POD structs. */
3095 /* If any field is const, the structure type is pseudo-const. */
3097 {
3102 /* ARM $12.6.2: [A member initializer list] (or, for an
3103 aggregate, initialization by a brace-enclosed list) is the
3104 only way to initialize nonstatic const and reference
3105 members. */
3107 }
3108 /* A field that is pseudo-const makes the structure likewise. */
3110 {
3115 }
3117 /* Core issue 80: A nonstatic data member is required to have a
3118 different name from the class iff the class has a
3119 user-declared constructor. */
3124 /* We set DECL_C_BIT_FIELD in grokbitfield.
3125 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3128 cant_have_const_ctor_p,
3129 no_const_asn_ref_p,
3131 }
3133 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3134 it should also define a copy constructor and an assignment operator to
3135 implement the correct copy semantic (deep vs shallow, etc.). As it is
3136 not feasible to check whether the constructors do allocate dynamic memory
3137 and store it within members, we approximate the warning like this:
3139 -- Warn only if there are members which are pointers
3140 -- Warn only if there is a non-trivial constructor (otherwise,
3141 there cannot be memory allocated).
3142 -- Warn only if there is a non-trivial destructor. We assume that the
3143 user at least implemented the cleanup correctly, and a destructor
3144 is needed to free dynamic memory.
3146 This seems enough for practical purposes. */
3148 && has_pointers
3152 {
3156 {
3161 }
3165 }
3167 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3171 /* Check anonymous struct/anonymous union fields. */
3174 /* We've built up the list of access declarations in reverse order.
3175 Fix that now. */
3177 }
3179 /* If TYPE is an empty class type, records its OFFSET in the table of
3180 OFFSETS. */
3182 static int
3184 {
3185 splay_tree_node n;
3190 /* Record the location of this empty object in OFFSETS. */
3198 type,
3202 }
3204 /* Returns nonzero if TYPE is an empty class type and there is
3205 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3207 static int
3209 {
3210 splay_tree_node n;
3211 tree t;
3216 /* Record the location of this empty object in OFFSETS. */
3226 }
3228 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3229 F for every subobject, passing it the type, offset, and table of
3230 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3231 be traversed.
3233 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3234 than MAX_OFFSET will not be walked.
3236 If F returns a nonzero value, the traversal ceases, and that value
3237 is returned. Otherwise, returns zero. */
3239 static int
3241 subobject_offset_fn f,
3242 tree offset,
3243 splay_tree offsets,
3244 tree max_offset,
3246 {
3250 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3251 stop. */
3259 {
3263 }
3266 {
3267 tree field;
3268 tree binfo;
3271 /* Avoid recursing into objects that are not interesting. */
3275 /* Record the location of TYPE. */
3280 /* Iterate through the direct base classes of TYPE. */
3284 {
3285 tree binfo_offset;
3298 offset,
3300 else
3301 {
3302 tree orig_binfo;
3303 /* We cannot rely on BINFO_OFFSET being set for the base
3304 class yet, but the offsets for direct non-virtual
3305 bases can be calculated by going back to the TYPE. */
3308 offset,
3310 }
3313 f,
3314 binfo_offset,
3315 offsets,
3316 max_offset,
3321 }
3324 {
3328 /* Iterate through the virtual base classes of TYPE. In G++
3329 3.2, we included virtual bases in the direct base class
3330 loop above, which results in incorrect results; the
3331 correct offsets for virtual bases are only known when
3332 working with the most derived type. */
3336 {
3338 f,
3340 offset,
3342 offsets,
3343 max_offset,
3347 }
3348 else
3349 {
3350 /* We still have to walk the primary base, if it is
3351 virtual. (If it is non-virtual, then it was walked
3352 above.) */
3358 {
3359 r = (walk_subobject_offsets
3364 }
3365 }
3366 }
3368 /* Iterate through the fields of TYPE. */
3371 {
3372 tree field_offset;
3376 else
3377 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3381 f,
3383 offset,
3384 field_offset),
3385 offsets,
3386 max_offset,
3390 }
3391 }
3393 {
3396 tree index;
3398 /* Avoid recursing into objects that are not interesting. */
3403 /* Step through each of the elements in the array. */
3405 /* G++ 3.2 had an off-by-one error here. */
3410 {
3412 f,
3413 offset,
3414 offsets,
3415 max_offset,
3421 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3422 there's no point in iterating through the remaining
3423 elements of the array. */
3426 }
3427 }
3430 }
3432 /* Record all of the empty subobjects of TYPE (either a type or a
3433 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3434 is being placed at OFFSET; otherwise, it is a base class that is
3435 being placed at OFFSET. */
3437 static void
3439 tree offset,
3440 splay_tree offsets,
3442 {
3443 tree max_offset;
3444 /* If recording subobjects for a non-static data member or a
3445 non-empty base class , we do not need to record offsets beyond
3446 the size of the biggest empty class. Additional data members
3447 will go at the end of the class. Additional base classes will go
3448 either at offset zero (if empty, in which case they cannot
3449 overlap with offsets past the size of the biggest empty class) or
3450 at the end of the class.
3452 However, if we are placing an empty base class, then we must record
3453 all offsets, as either the empty class is at offset zero (where
3454 other empty classes might later be placed) or at the end of the
3455 class (where other objects might then be placed, so other empty
3456 subobjects might later overlap). */
3460 else
3464 }
3466 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3467 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3468 virtual bases of TYPE are examined. */
3470 static int
3472 tree offset,
3473 splay_tree offsets,
3475 {
3476 splay_tree_node max_node;
3478 /* Get the node in OFFSETS that indicates the maximum offset where
3479 an empty subobject is located. */
3481 /* If there aren't any empty subobjects, then there's no point in
3482 performing this check. */
3488 vbases_p);
3489 }
3491 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3492 non-static data member of the type indicated by RLI. BINFO is the
3493 binfo corresponding to the base subobject, OFFSETS maps offsets to
3494 types already located at those offsets. This function determines
3495 the position of the DECL. */
3497 static void
3499 tree decl,
3500 tree binfo,
3501 splay_tree offsets)
3502 {
3505 tree type;
3508 {
3509 /* For the purposes of determining layout conflicts, we want to
3510 use the class type of BINFO; TREE_TYPE (DECL) will be the
3511 CLASSTYPE_AS_BASE version, which does not contain entries for
3512 zero-sized bases. */
3515 }
3516 else
3517 {
3520 }
3522 /* Try to place the field. It may take more than one try if we have
3523 a hard time placing the field without putting two objects of the
3524 same type at the same address. */
3526 {
3529 /* Place this field. */
3533 /* We have to check to see whether or not there is already
3534 something of the same type at the offset we're about to use.
3535 For example, consider:
3537 struct S {};
3538 struct T : public S { int i; };
3539 struct U : public S, public T {};
3541 Here, we put S at offset zero in U. Then, we can't put T at
3542 offset zero -- its S component would be at the same address
3543 as the S we already allocated. So, we have to skip ahead.
3544 Since all data members, including those whose type is an
3545 empty class, have nonzero size, any overlap can happen only
3546 with a direct or indirect base-class -- it can't happen with
3547 a data member. */
3548 /* In a union, overlap is permitted; all members are placed at
3549 offset zero. */
3552 /* G++ 3.2 did not check for overlaps when placing a non-empty
3553 virtual base. */
3558 {
3559 /* Strip off the size allocated to this field. That puts us
3560 at the first place we could have put the field with
3561 proper alignment. */
3564 /* Bump up by the alignment required for the type. */
3565 rli->bitpos
3571 }
3572 else
3573 /* There was no conflict. We're done laying out this field. */
3575 }
3577 /* Now that we know where it will be placed, update its
3578 BINFO_OFFSET. */
3580 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3581 this point because their BINFO_OFFSET is copied from another
3582 hierarchy. Therefore, we may not need to add the entire
3583 OFFSET. */
3589 }
3591 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3593 static int
3595 tree offset,
3596 splay_tree offsets ATTRIBUTE_UNUSED)
3597 {
3599 }
3601 /* Layout the empty base BINFO. EOC indicates the byte currently just
3602 past the end of the class, and should be correctly aligned for a
3603 class of the type indicated by BINFO; OFFSETS gives the offsets of
3604 the empty bases allocated so far. T is the most derived
3605 type. Return nonzero iff we added it at the end. */
3607 static bool
3610 {
3611 tree alignment;
3615 /* This routine should only be used for empty classes. */
3620 {
3622 propagate_binfo_offsets
3625 else
3627 "offset of empty base %qT may not be ABI-compliant and may"
3630 }
3632 /* This is an empty base class. We first try to put it at offset
3633 zero. */
3636 offsets,
3638 {
3639 /* That didn't work. Now, we move forward from the next
3640 available spot in the class. */
3644 {
3647 offsets,
3649 /* We finally found a spot where there's no overlap. */
3652 /* There's overlap here, too. Bump along to the next spot. */
3654 }
3655 }
3658 {
3663 }
3666 }
3668 /* Layout the base given by BINFO in the class indicated by RLI.
3669 *BASE_ALIGN is a running maximum of the alignments of
3670 any base class. OFFSETS gives the location of empty base
3671 subobjects. T is the most derived type. Return nonzero if the new
3672 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3673 *NEXT_FIELD, unless BINFO is for an empty base class.
3675 Returns the location at which the next field should be inserted. */
3680 {
3685 /* This error is now reported in xref_tag, thus giving better
3686 location information. */
3689 /* Place the base class. */
3691 {
3692 tree decl;
3694 /* The containing class is non-empty because it has a non-empty
3695 base class. */
3698 /* Create the FIELD_DECL. */
3705 {
3713 /* Try to place the field. It may take more than one try if we
3714 have a hard time placing the field without putting two
3715 objects of the same type at the same address. */
3717 /* Add the new FIELD_DECL to the list of fields for T. */
3721 }
3722 }
3723 else
3724 {
3725 tree eoc;
3728 /* On some platforms (ARM), even empty classes will not be
3729 byte-aligned. */
3734 /* A nearly-empty class "has no proper base class that is empty,
3735 not morally virtual, and at an offset other than zero." */
3737 {
3740 /* The check above (used in G++ 3.2) is insufficient because
3741 an empty class placed at offset zero might itself have an
3742 empty base at a nonzero offset. */
3744 empty_base_at_nonzero_offset_p,
3745 size_zero_node,
3749 {
3752 else
3754 "class %qT will be considered nearly empty in a "
3756 }
3757 }
3759 /* We do not create a FIELD_DECL for empty base classes because
3760 it might overlap some other field. We want to be able to
3761 create CONSTRUCTORs for the class by iterating over the
3762 FIELD_DECLs, and the back end does not handle overlapping
3763 FIELD_DECLs. */
3765 /* An empty virtual base causes a class to be non-empty
3766 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3767 here because that was already done when the virtual table
3768 pointer was created. */
3769 }
3771 /* Record the offsets of BINFO and its base subobjects. */
3774 offsets,
3778 }
3780 /* Layout all of the non-virtual base classes. Record empty
3781 subobjects in OFFSETS. T is the most derived type. Return nonzero
3782 if the type cannot be nearly empty. The fields created
3783 corresponding to the base classes will be inserted at
3784 *NEXT_FIELD. */
3786 static void
3789 {
3790 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3791 subobjects. */
3796 /* The primary base class is always allocated first. */
3801 /* Now allocate the rest of the bases. */
3803 {
3804 tree base_binfo;
3808 /* The primary base was already allocated above, so we don't
3809 need to allocate it again here. */
3813 /* Virtual bases are added at the end (a primary virtual base
3814 will have already been added). */
3820 }
3821 }
3823 /* Go through the TYPE_METHODS of T issuing any appropriate
3824 diagnostics, figuring out which methods override which other
3825 methods, and so forth. */
3827 static void
3829 {
3830 tree x;
3833 {
3837 /* The name of the field is the original field name
3838 Save this in auxiliary field for later overloading. */
3840 {
3844 }
3845 /* All user-provided destructors are non-trivial. */
3848 }
3849 }
3851 /* FN is a constructor or destructor. Clone the declaration to create
3852 a specialized in-charge or not-in-charge version, as indicated by
3853 NAME. */
3855 static tree
3857 {
3858 tree parms;
3859 tree clone;
3861 /* Copy the function. */
3863 /* Reset the function name. */
3866 /* Remember where this function came from. */
3868 /* Make it easy to find the CLONE given the FN. */
3872 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
3874 {
3881 }
3884 /* There's no pending inline data for this function. */
3888 /* The base-class destructor is not virtual. */
3890 {
3894 }
3896 /* If there was an in-charge parameter, drop it from the function
3897 type. */
3899 {
3900 tree basetype;
3901 tree parmtypes;
3902 tree exceptions;
3907 /* Skip the `this' parameter. */
3909 /* Skip the in-charge parameter. */
3911 /* And the VTT parm, in a complete [cd]tor. */
3915 /* If this is subobject constructor or destructor, add the vtt
3916 parameter. */
3920 parmtypes);
3923 exceptions);
3927 }
3929 /* Copy the function parameters. */
3931 /* Remove the in-charge parameter. */
3933 {
3937 }
3938 /* And the VTT parm, in a complete [cd]tor. */
3940 {
3943 else
3944 {
3948 }
3949 }
3952 {
3955 }
3957 /* Create the RTL for this function. */
3965 }
3967 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
3968 not invoke this function directly.
3970 For a non-thunk function, returns the address of the slot for storing
3971 the function it is a clone of. Otherwise returns NULL_TREE.
3973 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
3974 cloned_function is unset. This is to support the separate
3975 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
3976 on a template makes sense, but not the former. */
3978 tree *
3980 {
3988 {
3989 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
3992 else
3993 #endif
3995 }
4000 else
4002 }
4004 /* Produce declarations for all appropriate clones of FN. If
4005 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4006 CLASTYPE_METHOD_VEC as well. */
4008 void
4010 {
4011 tree clone;
4013 /* Avoid inappropriate cloning. */
4019 {
4020 /* For each constructor, we need two variants: an in-charge version
4021 and a not-in-charge version. */
4028 }
4029 else
4030 {
4033 /* For each destructor, we need three variants: an in-charge
4034 version, a not-in-charge version, and an in-charge deleting
4035 version. We clone the deleting version first because that
4036 means it will go second on the TYPE_METHODS list -- and that
4037 corresponds to the correct layout order in the virtual
4038 function table.
4040 For a non-virtual destructor, we do not build a deleting
4041 destructor. */
4043 {
4047 }
4054 }
4056 /* Note that this is an abstract function that is never emitted. */
4058 }
4060 /* DECL is an in charge constructor, which is being defined. This will
4061 have had an in class declaration, from whence clones were
4062 declared. An out-of-class definition can specify additional default
4063 arguments. As it is the clones that are involved in overload
4064 resolution, we must propagate the information from the DECL to its
4065 clones. */
4067 void
4069 {
4070 tree clone;
4074 {
4081 /* Skip the 'this' parameter. */
4097 {
4102 {
4103 /* A default parameter has been added. Adjust the
4104 clone's parameters. */
4107 tree type;
4112 {
4115 clone_parms);
4117 }
4120 clone_parms);
4127 }
4128 }
4130 }
4131 }
4133 /* For each of the constructors and destructors in T, create an
4134 in-charge and not-in-charge variant. */
4136 static void
4138 {
4139 tree fns;
4141 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4142 out now. */
4150 }
4152 /* Returns true iff class T has a user-defined constructor other than
4153 the default constructor. */
4155 bool
4157 {
4158 tree fns;
4164 {
4171 }
4174 }
4176 /* Returns true iff FN is a user-provided function, i.e. user-declared
4177 and not defaulted at its first declaration. */
4179 static bool
4181 {
4184 else
4188 }
4190 /* Returns true iff class T has a user-provided constructor. */
4192 bool
4194 {
4195 tree fns;
4203 /* This can happen in error cases; avoid crashing. */
4212 }
4214 /* Returns true iff class T has a user-provided default constructor. */
4216 bool
4218 {
4225 {
4229 {
4235 }
4236 }
4239 }
4241 /* Returns true if FN can be explicitly defaulted. */
4243 bool
4245 {
4247 {
4254 else
4256 }
4262 else
4264 }
4266 /* Remove all zero-width bit-fields from T. */
4268 static void
4270 {
4275 {
4280 else
4282 }
4283 }
4285 /* Returns TRUE iff we need a cookie when dynamically allocating an
4286 array whose elements have the indicated class TYPE. */
4288 static bool
4290 {
4291 tree fns;
4296 /* If there's a non-trivial destructor, we need a cookie. In order
4297 to iterate through the array calling the destructor for each
4298 element, we'll have to know how many elements there are. */
4302 /* If the usual deallocation function is a two-argument whose second
4303 argument is of type `size_t', then we have to pass the size of
4304 the array to the deallocation function, so we will need to store
4305 a cookie. */
4309 /* If there are no `operator []' members, or the lookup is
4310 ambiguous, then we don't need a cookie. */
4313 /* Loop through all of the functions. */
4315 {
4316 tree fn;
4317 tree second_parm;
4319 /* Select the current function. */
4321 /* See if this function is a one-argument delete function. If
4322 it is, then it will be the usual deallocation function. */
4326 /* Do not consider this function if its second argument is an
4327 ellipsis. */
4330 /* Otherwise, if we have a two-argument function and the second
4331 argument is `size_t', it will be the usual deallocation
4332 function -- unless there is one-argument function, too. */
4336 }
4339 }
4341 /* Check the validity of the bases and members declared in T. Add any
4342 implicitly-generated functions (like copy-constructors and
4343 assignment operators). Compute various flag bits (like
4344 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
4345 level: i.e., independently of the ABI in use. */
4347 static void
4349 {
4350 /* Nonzero if the implicitly generated copy constructor should take
4351 a non-const reference argument. */
4353 /* Nonzero if the implicitly generated assignment operator
4354 should take a non-const reference argument. */
4356 tree access_decls;
4360 /* By default, we use const reference arguments and generate default
4361 constructors. */
4365 /* Check all the base-classes. */
4369 /* Check all the method declarations. */
4372 /* Save the initial values of these flags which only indicate whether
4373 or not the class has user-provided functions. As we analyze the
4374 bases and members we can set these flags for other reasons. */
4378 /* Check all the data member declarations. We cannot call
4379 check_field_decls until we have called check_bases check_methods,
4380 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4381 being set appropriately. */
4386 /* A nearly-empty class has to be vptr-containing; a nearly empty
4387 class contains just a vptr. */
4391 /* Do some bookkeeping that will guide the generation of implicitly
4392 declared member functions. */
4394 /* We need to call a constructor for this class if it has a
4395 user-provided constructor, or if the default constructor is going
4396 to initialize the vptr. (This is not an if-and-only-if;
4397 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
4398 themselves need constructing.) */
4401 /* [dcl.init.aggr]
4403 An aggregate is an array or a class with no user-provided
4404 constructors ... and no virtual functions.
4406 Again, other conditions for being an aggregate are checked
4407 elsewhere. */
4410 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
4411 retain the old definition internally for ABI reasons. */
4419 /* If the class has no user-declared constructor, but does have
4420 non-static const or reference data members that can never be
4421 initialized, issue a warning. */
4423 /* Classes with user-declared constructors are presumed to
4424 initialize these members. */
4426 /* Aggregates can be initialized with brace-enclosed
4427 initializers. */
4429 {
4430 tree field;
4433 {
4434 tree type;
4448 }
4449 }
4451 /* Synthesize any needed methods. */
4453 cant_have_const_ctor,
4454 no_const_asn_ref);
4457 {
4458 /* "The closure type associated with a lambda-expression has a deleted
4459 default constructor and a deleted copy assignment operator." */
4466 /* "This class type is not an aggregate." */
4468 }
4470 /* Create the in-charge and not-in-charge variants of constructors
4471 and destructors. */
4474 /* Process the using-declarations. */
4478 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4481 /* Figure out whether or not we will need a cookie when dynamically
4482 allocating an array of this type. */
4485 }
4487 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4488 accordingly. If a new vfield was created (because T doesn't have a
4489 primary base class), then the newly created field is returned. It
4490 is not added to the TYPE_FIELDS list; it is the caller's
4491 responsibility to do that. Accumulate declared virtual functions
4492 on VIRTUALS_P. */
4494 static tree
4496 {
4497 tree fn;
4499 /* Collect the virtual functions declared in T. */
4503 {
4512 }
4514 /* If we couldn't find an appropriate base class, create a new field
4515 here. Even if there weren't any new virtual functions, we might need a
4516 new virtual function table if we're supposed to include vptrs in
4517 all classes that need them. */
4519 {
4520 /* We build this decl with vtbl_ptr_type_node, which is a
4521 `vtable_entry_type*'. It might seem more precise to use
4522 `vtable_entry_type (*)[N]' where N is the number of virtual
4523 functions. However, that would require the vtable pointer in
4524 base classes to have a different type than the vtable pointer
4525 in derived classes. We could make that happen, but that
4526 still wouldn't solve all the problems. In particular, the
4527 type-based alias analysis code would decide that assignments
4528 to the base class vtable pointer can't alias assignments to
4529 the derived class vtable pointer, since they have different
4530 types. Thus, in a derived class destructor, where the base
4531 class constructor was inlined, we could generate bad code for
4532 setting up the vtable pointer.
4534 Therefore, we use one type for all vtable pointers. We still
4535 use a type-correct type; it's just doesn't indicate the array
4536 bounds. That's better than using `void*' or some such; it's
4537 cleaner, and it let's the alias analysis code know that these
4538 stores cannot alias stores to void*! */
4539 tree field;
4550 /* This class is non-empty. */
4554 }
4557 }
4559 /* Add OFFSET to all base types of BINFO which is a base in the
4560 hierarchy dominated by T.
4562 OFFSET, which is a type offset, is number of bytes. */
4564 static void
4566 {
4568 tree primary_binfo;
4569 tree base_binfo;
4571 /* Update BINFO's offset. */
4576 offset));
4578 /* Find the primary base class. */
4584 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4585 downwards. */
4587 {
4588 /* Don't do the primary base twice. */
4596 }
4597 }
4599 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4600 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4601 empty subobjects of T. */
4603 static void
4605 {
4606 tree vbase;
4615 {
4616 /* In G++ 3.2, we incorrectly rounded the size before laying out
4617 the virtual bases. */
4619 #ifdef STRUCTURE_SIZE_BOUNDARY
4620 /* Packed structures don't need to have minimum size. */
4623 #endif
4627 }
4629 /* Find the last field. The artificial fields created for virtual
4630 bases will go after the last extant field to date. */
4635 /* Go through the virtual bases, allocating space for each virtual
4636 base that is not already a primary base class. These are
4637 allocated in inheritance graph order. */
4639 {
4644 {
4647 /* This virtual base is not a primary base of any class in the
4648 hierarchy, so we have to add space for it. */
4652 /* If the first virtual base might have been placed at a
4653 lower address, had we started from CLASSTYPE_SIZE, rather
4654 than TYPE_SIZE, issue a warning. There can be both false
4655 positives and false negatives from this warning in rare
4656 cases; to deal with all the possibilities would probably
4657 require performing both layout algorithms and comparing
4658 the results which is not particularly tractable. */
4660 && first_vbase
4661 && (tree_int_cst_lt
4666 bitsize_unit_node),
4669 "offset of virtual base %qT is not ABI-compliant and "
4671 basetype);
4674 }
4675 }
4676 }
4678 /* Returns the offset of the byte just past the end of the base class
4679 BINFO. */
4681 static tree
4683 {
4684 tree size;
4689 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4690 allocate some space for it. It cannot have virtual bases, so
4691 TYPE_SIZE_UNIT is fine. */
4693 else
4697 }
4699 /* Returns the offset of the byte just past the end of the base class
4700 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4701 only non-virtual bases are included. */
4703 static tree
4705 {
4708 tree binfo;
4709 tree base_binfo;
4710 tree offset;
4715 {
4725 }
4727 /* G++ 3.2 did not check indirect virtual bases. */
4731 {
4735 }
4738 }
4740 /* Warn about bases of T that are inaccessible because they are
4741 ambiguous. For example:
4743 struct S {};
4744 struct T : public S {};
4745 struct U : public S, public T {};
4747 Here, `(S*) new U' is not allowed because there are two `S'
4748 subobjects of U. */
4750 static void
4752 {
4755 tree basetype;
4756 tree binfo;
4757 tree base_binfo;
4759 /* If there are no repeated bases, nothing can be ambiguous. */
4763 /* Check direct bases. */
4766 {
4772 }
4774 /* Check for ambiguous virtual bases. */
4778 {
4784 }
4785 }
4787 /* Compare two INTEGER_CSTs K1 and K2. */
4789 static int
4791 {
4793 }
4795 /* Increase the size indicated in RLI to account for empty classes
4796 that are "off the end" of the class. */
4798 static void
4800 {
4801 tree eoc;
4802 tree rli_size;
4804 /* It might be the case that we grew the class to allocate a
4805 zero-sized base class. That won't be reflected in RLI, yet,
4806 because we are willing to overlay multiple bases at the same
4807 offset. However, now we need to make sure that RLI is big enough
4808 to reflect the entire class. */
4814 {
4816 /* In version 1 of the ABI, the size of a class that ends with
4817 a bitfield was not rounded up to a whole multiple of a
4818 byte. Because rli_size_unit_so_far returns only the number
4819 of fully allocated bytes, any extra bits were not included
4820 in the size. */
4822 else
4823 /* The size should have been rounded to a whole byte. */
4826 rli->bitpos
4835 }
4836 }
4838 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4839 BINFO_OFFSETs for all of the base-classes. Position the vtable
4840 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4842 static void
4844 {
4845 tree non_static_data_members;
4846 tree field;
4847 tree vptr;
4848 record_layout_info rli;
4849 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4850 types that appear at that offset. */
4851 splay_tree empty_base_offsets;
4852 /* True if the last field layed out was a bit-field. */
4854 /* The location at which the next field should be inserted. */
4856 /* T, as a base class. */
4857 tree base_t;
4859 /* Keep track of the first non-static data member. */
4862 /* Start laying out the record. */
4865 /* Mark all the primary bases in the hierarchy. */
4868 /* Create a pointer to our virtual function table. */
4871 /* The vptr is always the first thing in the class. */
4873 {
4878 }
4879 else
4882 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4887 /* Layout the non-static data members. */
4889 {
4890 tree type;
4891 tree padding;
4893 /* We still pass things that aren't non-static data members to
4894 the back end, in case it wants to do something with them. */
4896 {
4898 /* If the static data member has incomplete type, keep track
4899 of it so that it can be completed later. (The handling
4900 of pending statics in finish_record_layout is
4901 insufficient; consider:
4903 struct S1;
4904 struct S2 { static S1 s1; };
4906 At this point, finish_record_layout will be called, but
4907 S1 is still incomplete.) */
4909 {
4911 /* The visibility of static data members is determined
4912 at their point of declaration, not their point of
4913 definition. */
4915 }
4917 }
4925 /* If this field is a bit-field whose width is greater than its
4926 type, then there are some special rules for allocating
4927 it. */
4930 {
4932 tree integer_type;
4934 /* We must allocate the bits as if suitably aligned for the
4935 longest integer type that fits in this many bits. type
4936 of the field. Then, we are supposed to use the left over
4937 bits as additional padding. */
4943 /* ITK now indicates a type that is too large for the
4944 field. We have to back up by one to find the largest
4945 type that fits. */
4948 /* Figure out how much additional padding is required. GCC
4949 3.2 always created a padding field, even if it had zero
4950 width. */
4953 {
4955 /* In a union, the padding field must have the full width
4956 of the bit-field; all fields start at offset zero. */
4958 else
4959 {
4962 "ABI-compliant and may change in a future "
4964 t);
4967 }
4968 }
4969 #ifdef PCC_BITFIELD_TYPE_MATTERS
4970 /* An unnamed bitfield does not normally affect the
4971 alignment of the containing class on a target where
4972 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4973 make any exceptions for unnamed bitfields when the
4974 bitfields are longer than their types. Therefore, we
4975 temporarily give the field a name. */
4977 {
4980 }
4981 #endif
4986 empty_base_offsets);
4989 /* Now that layout has been performed, set the size of the
4990 field to the size of its declared type; the rest of the
4991 field is effectively invisible. */
4993 /* We must also reset the DECL_MODE of the field. */
4998 /* Versions of G++ before G++ 3.4 did not reset the
4999 DECL_MODE. */
5001 "the offset of %qD may not be ABI-compliant and may "
5003 }
5004 else
5006 empty_base_offsets);
5008 /* Remember the location of any empty classes in FIELD. */
5012 empty_base_offsets,
5015 /* If a bit-field does not immediately follow another bit-field,
5016 and yet it starts in the middle of a byte, we have failed to
5017 comply with the ABI. */
5020 /* The TREE_NO_WARNING flag gets set by Objective-C when
5021 laying out an Objective-C class. The ObjC ABI differs
5022 from the C++ ABI, and so we do not want a warning
5023 here. */
5025 && !last_field_was_bitfield
5028 bitsize_unit_node)))
5032 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5033 offset of the field. */
5039 "classes to be placed at different locations in a "
5042 /* The middle end uses the type of expressions to determine the
5043 possible range of expression values. In order to optimize
5044 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5045 must be made aware of the width of "i", via its type.
5047 Because C++ does not have integer types of arbitrary width,
5048 we must (for the purposes of the front end) convert from the
5049 type assigned here to the declared type of the bitfield
5050 whenever a bitfield expression is used as an rvalue.
5051 Similarly, when assigning a value to a bitfield, the value
5052 must be converted to the type given the bitfield here. */
5054 {
5059 {
5066 }
5067 }
5069 /* If we needed additional padding after this field, add it
5070 now. */
5072 {
5073 tree padding_field;
5076 FIELD_DECL,
5077 NULL_TREE,
5078 char_type_node);
5085 NULL_TREE,
5086 empty_base_offsets);
5087 }
5090 }
5093 {
5094 /* Make sure that we are on a byte boundary so that the size of
5095 the class without virtual bases will always be a round number
5096 of bytes. */
5099 }
5101 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5102 padding. */
5106 /* Delete all zero-width bit-fields from the list of fields. Now
5107 that the type is laid out they are no longer important. */
5110 /* Create the version of T used for virtual bases. We do not use
5111 make_class_type for this version; this is an artificial type. For
5112 a POD type, we just reuse T. */
5114 {
5117 /* Set the size and alignment for the new type. In G++ 3.2, all
5118 empty classes were considered to have size zero when used as
5119 base classes. */
5121 {
5126 "layout of classes derived from empty class %qT "
5128 t);
5129 }
5130 else
5131 {
5132 tree eoc;
5134 /* If the ABI version is not at least two, and the last
5135 field was a bit-field, RLI may not be on a byte
5136 boundary. In particular, rli_size_unit_so_far might
5137 indicate the last complete byte, while rli_size_so_far
5138 indicates the total number of bits used. Therefore,
5139 rli_size_so_far, rather than rli_size_unit_so_far, is
5140 used to compute TYPE_SIZE_UNIT. */
5148 eoc);
5155 }
5159 /* Copy the fields from T. */
5163 {
5165 FIELD_DECL,
5175 }
5177 /* Record the base version of the type. */
5180 }
5181 else
5184 /* Every empty class contains an empty class. */
5188 /* Set the TYPE_DECL for this type to contain the right
5189 value for DECL_OFFSET, so that we can use it as part
5190 of a COMPONENT_REF for multiple inheritance. */
5193 /* Now fix up any virtual base class types that we left lying
5194 around. We must get these done before we try to lay out the
5195 virtual function table. As a side-effect, this will remove the
5196 base subobject fields. */
5199 /* Make sure that empty classes are reflected in RLI at this
5200 point. */
5203 /* Make sure not to create any structures with zero size. */
5209 /* Let the back end lay out the type. */
5212 /* Warn about bases that can't be talked about due to ambiguity. */
5215 /* Now that we're done with layout, give the base fields the real types. */
5220 /* Clean up. */
5227 }
5229 /* Determine the "key method" for the class type indicated by TYPE,
5230 and set CLASSTYPE_KEY_METHOD accordingly. */
5232 void
5234 {
5235 tree method;
5238 || processing_template_decl
5243 /* The key method is the first non-pure virtual function that is not
5244 inline at the point of class definition. On some targets the
5245 key function may not be inline; those targets should not call
5246 this function until the end of the translation unit. */
5252 {
5255 }
5258 }
5260 /* Perform processing required when the definition of T (a class type)
5261 is complete. */
5263 void
5265 {
5266 tree x;
5267 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5272 {
5277 }
5279 /* If this type was previously laid out as a forward reference,
5280 make sure we lay it out again. */
5284 /* Make assumptions about the class; we'll reset the flags if
5285 necessary. */
5290 /* Do end-of-class semantic processing: checking the validity of the
5291 bases and members and add implicitly generated methods. */
5294 /* Find the key method. */
5296 {
5297 /* The Itanium C++ ABI permits the key method to be chosen when
5298 the class is defined -- even though the key method so
5299 selected may later turn out to be an inline function. On
5300 some systems (such as ARM Symbian OS) the key method cannot
5301 be determined until the end of the translation unit. On such
5302 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
5303 will cause the class to be added to KEYED_CLASSES. Then, in
5304 finish_file we will determine the key method. */
5308 /* If a polymorphic class has no key method, we may emit the vtable
5309 in every translation unit where the class definition appears. */
5312 }
5314 /* Layout the class itself. */
5317 /* We use the base type for trivial assignments, and hence it
5318 needs a mode. */
5323 /* If necessary, create the primary vtable for this class. */
5325 {
5326 /* We must enter these virtuals into the table. */
5330 /* Here we know enough to change the type of our virtual
5331 function table, but we will wait until later this function. */
5333 }
5336 {
5338 tree fn;
5345 /* Add entries for virtual functions introduced by this class. */
5349 /* Set DECL_VINDEX for all functions declared in this class. */
5351 fn;
5353 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5355 {
5359 /* A thunk. We should never be calling this entry directly
5360 from this vtable -- we'd use the entry for the non
5361 thunk base function. */
5365 }
5366 }
5370 /* Complete the rtl for any static member objects of the type we're
5371 working on. */
5378 /* Done with FIELDS...now decide whether to sort these for
5379 faster lookups later.
5381 We use a small number because most searches fail (succeeding
5382 ultimately as the search bores through the inheritance
5383 hierarchy), and we want this failure to occur quickly. */
5387 {
5394 field_decl_cmp);
5396 }
5398 /* Complain if one of the field types requires lower visibility. */
5401 /* Make the rtl for any new vtables we have created, and unmark
5402 the base types we marked. */
5405 /* Build the VTT for T. */
5408 /* This warning does not make sense for Java classes, since they
5409 cannot have destructors. */
5411 {
5412 tree dtor;
5416 if it were virtual, we would have created it by now. */
5417 !dtor
5426 "%q#T has virtual functions and accessible"
5428 }
5435 /* Class layout, assignment of virtual table slots, etc., is now
5436 complete. Give the back end a chance to tweak the visibility of
5437 the class or perform any other required target modifications. */
5444 /* Finish debugging output for this type. */
5446 }
5448 /* When T was built up, the member declarations were added in reverse
5449 order. Rearrange them to declaration order. */
5451 void
5453 {
5454 tree next;
5455 tree prev;
5456 tree x;
5458 /* The following lists are all in reverse order. Put them in
5459 declaration order now. */
5463 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5464 reverse order, so we can't just use nreverse. */
5469 {
5473 }
5475 {
5479 }
5480 }
5482 tree
5484 {
5487 /* Now that we've got all the field declarations, reverse everything
5488 as necessary. */
5493 /* Nadger the current location so that diagnostics point to the start of
5494 the struct, not the end. */
5498 {
5499 tree x;
5505 /* We need to emit an error message if this type was used as a parameter
5506 and it is an abstract type, even if it is a template. We construct
5507 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5508 account and we call complete_vars with this type, which will check
5509 the PARM_DECLS. Note that while the type is being defined,
5510 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5511 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5517 }
5518 else
5527 else
5534 }
5535 \f
5536 /* Return the dynamic type of INSTANCE, if known.
5537 Used to determine whether the virtual function table is needed
5538 or not.
5540 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5541 of our knowledge of its type. *NONNULL should be initialized
5542 before this function is called. */
5544 static tree
5546 {
5547 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
5550 {
5554 else
5558 /* This is a call to a constructor, hence it's never zero. */
5560 {
5564 }
5568 /* This is a call to a constructor, hence it's never zero. */
5570 {
5574 }
5583 /* Propagate nonnull. */
5588 CASE_CONVERT:
5594 {
5595 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5596 with a real object -- given &p->f, p can still be null. */
5598 /* ??? Probably should check DECL_WEAK here. */
5601 }
5605 /* If this component is really a base class reference, then the field
5606 itself isn't definitive. */
5615 {
5619 }
5620 /* fall through... */
5625 {
5629 }
5631 {
5635 /* if we're in a ctor or dtor, we know our type. */
5639 {
5643 }
5644 }
5646 {
5647 /* We only need one hash table because it is always left empty. */
5651 htab_hash_pointer,
5652 htab_eq_pointer,
5655 /* Reference variables should be references to objects. */
5659 /* Enter the INSTANCE in a table to prevent recursion; a
5660 variable's initializer may refer to the variable
5661 itself. */
5665 {
5666 tree type;
5675 }
5676 }
5681 }
5682 #undef RECUR
5683 }
5685 /* Return nonzero if the dynamic type of INSTANCE is known, and
5686 equivalent to the static type. We also handle the case where
5687 INSTANCE is really a pointer. Return negative if this is a
5688 ctor/dtor. There the dynamic type is known, but this might not be
5689 the most derived base of the original object, and hence virtual
5690 bases may not be layed out according to this type.
5692 Used to determine whether the virtual function table is needed
5693 or not.
5695 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5696 of our knowledge of its type. *NONNULL should be initialized
5697 before this function is called. */
5699 int
5701 {
5712 }
5714 \f
5715 void
5717 {
5720 current_class_stack
5728 }
5730 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5732 static void
5734 {
5735 tree type;
5737 /* We are re-entering the same class we just left, so we don't
5738 have to search the whole inheritance matrix to find all the
5739 decls to bind again. Instead, we install the cached
5740 class_shadowed list and walk through it binding names. */
5743 /* Restore IDENTIFIER_TYPE_VALUE. */
5745 type;
5748 }
5750 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5751 appropriate for TYPE.
5753 So that we may avoid calls to lookup_name, we cache the _TYPE
5754 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5756 For multiple inheritance, we perform a two-pass depth-first search
5757 of the type lattice. */
5759 void
5761 {
5762 class_stack_node_t csn;
5766 /* Make sure there is enough room for the new entry on the stack. */
5768 {
5770 current_class_stack
5772 current_class_stack_size);
5773 }
5775 /* Insert a new entry on the class stack. */
5782 current_class_depth++;
5784 /* Now set up the new type. */
5790 /* By default, things in classes are private, while things in
5791 structures or unions are public. */
5793 ? access_private_node
5799 {
5800 /* Forcibly remove any old class remnants. */
5802 }
5808 else
5810 }
5812 /* When we exit a toplevel class scope, we save its binding level so
5813 that we can restore it quickly. Here, we've entered some other
5814 class, so we must invalidate our cache. */
5816 void
5818 {
5820 }
5822 /* Get out of the current class scope. If we were in a class scope
5823 previously, that is the one popped to. */
5825 void
5827 {
5830 current_class_depth--;
5836 }
5838 /* Mark the top of the class stack as hidden. */
5840 void
5842 {
5845 }
5847 /* Mark the top of the class stack as un-hidden. */
5849 void
5851 {
5854 }
5856 /* Returns 1 if the class type currently being defined is either T or
5857 a nested type of T. */
5859 bool
5861 {
5869 /* We start looking from 1 because entry 0 is from global scope,
5870 and has no type. */
5872 {
5873 tree c;
5876 else
5877 {
5881 }
5886 }
5888 }
5890 /* If either current_class_type or one of its enclosing classes are derived
5891 from T, return the appropriate type. Used to determine how we found
5892 something via unqualified lookup. */
5894 tree
5896 {
5899 /* The bases of a dependent type are unknown. */
5910 {
5915 }
5918 }
5920 /* When entering a class scope, all enclosing class scopes' names with
5921 static meaning (static variables, static functions, types and
5922 enumerators) have to be visible. This recursive function calls
5923 pushclass for all enclosing class contexts until global or a local
5924 scope is reached. TYPE is the enclosed class. */
5926 void
5928 {
5929 /* A namespace might be passed in error cases, like A::B:C. */
5937 }
5939 /* Undoes a push_nested_class call. */
5941 void
5943 {
5949 }
5951 /* Returns the number of extern "LANG" blocks we are nested within. */
5953 int
5955 {
5957 }
5959 /* Set global variables CURRENT_LANG_NAME to appropriate value
5960 so that behavior of name-mangling machinery is correct. */
5962 void
5964 {
5968 {
5970 }
5972 {
5974 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5975 (See record_builtin_java_type in decl.c.) However, that causes
5976 incorrect debug entries if these types are actually used.
5977 So we re-enable debug output after extern "Java". */
5986 }
5988 {
5990 }
5991 else
5993 }
5995 /* Get out of the current language scope. */
5997 void
5999 {
6001 }
6002 \f
6003 /* Type instantiation routines. */
6005 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
6006 matches the TARGET_TYPE. If there is no satisfactory match, return
6007 error_mark_node, and issue an error & warning messages under
6008 control of FLAGS. Permit pointers to member function if FLAGS
6009 permits. If TEMPLATE_ONLY, the name of the overloaded function was
6010 a template-id, and EXPLICIT_TARGS are the explicitly provided
6011 template arguments.
6013 If OVERLOAD is for one or more member functions, then ACCESS_PATH
6014 is the base path used to reference those member functions. If
6015 TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is
6016 resolved to a member function, access checks will be performed and
6017 errors issued if appropriate. */
6019 static tree
6021 tree overload,
6022 tsubst_flags_t flags,
6024 tree explicit_targs,
6025 tree access_path)
6026 {
6027 /* Here's what the standard says:
6029 [over.over]
6031 If the name is a function template, template argument deduction
6032 is done, and if the argument deduction succeeds, the deduced
6033 arguments are used to generate a single template function, which
6034 is added to the set of overloaded functions considered.
6036 Non-member functions and static member functions match targets of
6037 type "pointer-to-function" or "reference-to-function." Nonstatic
6038 member functions match targets of type "pointer-to-member
6039 function;" the function type of the pointer to member is used to
6040 select the member function from the set of overloaded member
6041 functions. If a nonstatic member function is selected, the
6042 reference to the overloaded function name is required to have the
6043 form of a pointer to member as described in 5.3.1.
6045 If more than one function is selected, any template functions in
6046 the set are eliminated if the set also contains a non-template
6047 function, and any given template function is eliminated if the
6048 set contains a second template function that is more specialized
6049 than the first according to the partial ordering rules 14.5.5.2.
6050 After such eliminations, if any, there shall remain exactly one
6051 selected function. */
6055 /* We store the matches in a TREE_LIST rooted here. The functions
6056 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
6057 interoperability with most_specialized_instantiation. */
6059 tree fn;
6061 /* By the time we get here, we should be seeing only real
6062 pointer-to-member types, not the internal POINTER_TYPE to
6063 METHOD_TYPE representation. */
6069 /* Check that the TARGET_TYPE is reasonable. */
6073 /* This is OK, too. */
6076 {
6077 /* This is OK, too. This comes from a conversion to reference
6078 type. */
6081 }
6082 else
6083 {
6089 }
6091 /* If we can find a non-template function that matches, we can just
6092 use it. There's no point in generating template instantiations
6093 if we're just going to throw them out anyhow. But, of course, we
6094 can only do this when we don't *need* a template function. */
6096 {
6097 tree fns;
6100 {
6102 tree fntype;
6105 /* We're not looking for templates just yet. */
6110 /* We're looking for a non-static member, and this isn't
6111 one, or vice versa. */
6114 /* Ignore functions which haven't been explicitly
6115 declared. */
6119 /* See if there's a match. */
6128 }
6129 }
6131 /* Now, if we've already got a match (or matches), there's no need
6132 to proceed to the template functions. But, if we don't have a
6133 match we need to look at them, too. */
6135 {
6136 tree target_fn_type;
6137 tree target_arg_types;
6138 tree target_ret_type;
6139 tree fns;
6142 tree arg;
6145 target_fn_type
6147 else
6152 /* Never do unification on the 'this' parameter. */
6165 {
6167 tree instantiation;
6168 tree instantiation_type;
6169 tree targs;
6172 /* We're only looking for templates. */
6177 /* We're not looking for a non-static member, and this is
6178 one, or vice versa. */
6181 /* Try to do argument deduction. */
6185 LOOKUP_NORMAL))
6186 /* Argument deduction failed. */
6189 /* Instantiate the template. */
6192 /* Instantiation failed. */
6195 /* See if there's a match. */
6198 instantiation_type =
6203 LOOKUP_NORMAL))
6205 }
6207 /* Now, remove all but the most specialized of the matches. */
6209 {
6214 NULL_TREE,
6215 NULL_TREE);
6216 }
6217 }
6219 /* Now we should have exactly one function in MATCHES. */
6221 {
6222 /* There were *no* matches. */
6224 {
6227 target_type);
6229 /* print_candidates expects a chain with the functions in
6230 TREE_VALUE slots, so we cons one up here (we're losing anyway,
6231 so why be clever?). */
6234 matches);
6237 }
6239 }
6241 {
6242 /* There were too many matches. First check if they're all
6243 the same function. */
6244 tree match;
6252 {
6254 {
6257 target_type);
6259 /* Since print_candidates expects the functions in the
6260 TREE_VALUE slot, we flip them here. */
6265 }
6268 }
6269 }
6271 /* Good, exactly one match. Now, convert it to the correct type. */
6276 {
6284 {
6287 }
6288 }
6290 /* If we're doing overload resolution purely for the purpose of
6291 determining conversion sequences, we should not consider the
6292 function used. If this conversion sequence is selected, the
6293 function will be marked as used at this point. */
6295 {
6296 /* Make =delete work with SFINAE. */
6301 }
6303 /* We could not check access to member functions when this
6304 expression was originally created since we did not know at that
6305 time to which function the expression referred. */
6308 {
6311 }
6315 else
6316 {
6317 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
6318 will mark the function as addressed, but here we must do it
6319 explicitly. */
6323 }
6324 }
6326 /* This function will instantiate the type of the expression given in
6327 RHS to match the type of LHSTYPE. If errors exist, then return
6328 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
6329 we complain on errors. If we are not complaining, never modify rhs,
6330 as overload resolution wants to try many possible instantiations, in
6331 the hope that at least one will work.
6333 For non-recursive calls, LHSTYPE should be a function, pointer to
6334 function, or a pointer to member function. */
6336 tree
6338 {
6345 {
6349 }
6352 {
6358 /* Microsoft allows `A::f' to be resolved to a
6359 pointer-to-member. */
6360 ;
6361 else
6362 {
6367 }
6368 }
6371 {
6374 }
6376 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
6377 deduce any type information. */
6379 {
6383 }
6385 /* There only a few kinds of expressions that may have a type
6386 dependent on overload resolution. */
6392 /* This should really only be used when attempting to distinguish
6393 what sort of a pointer to function we have. For now, any
6394 arithmetic operation which is not supported on pointers
6395 is rejected as an error. */
6398 {
6400 {
6406 /* Do not lose object's side effects. */
6410 }
6417 /* This can happen if we are forming a pointer-to-member for a
6418 member template. */
6421 /* Fall through. */
6424 {
6428 return
6432 }
6436 return
6440 access_path);
6443 {
6448 }
6455 }
6457 }
6458 \f
6459 /* Return the name of the virtual function pointer field
6460 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6461 this may have to look back through base types to find the
6462 ultimate field name. (For single inheritance, these could
6463 all be the same name. Who knows for multiple inheritance). */
6465 static tree
6467 {
6474 {
6480 }
6488 }
6490 void
6492 {
6493 #ifdef GATHER_STATISTICS
6497 {
6502 }
6503 #endif
6504 }
6506 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6507 according to [class]:
6508 The class-name is also inserted
6509 into the scope of the class itself. For purposes of access checking,
6510 the inserted class name is treated as if it were a public member name. */
6512 void
6514 {
6517 tree saved_cas;
6531 }
6533 /* Returns 1 if TYPE contains only padding bytes. */
6535 int
6537 {
6544 /* In G++ 3.2, whether or not a class was empty was determined by
6545 looking at its size. */
6548 else
6550 }
6552 /* Returns true if TYPE contains an empty class. */
6554 static bool
6556 {
6560 {
6561 tree field;
6562 tree binfo;
6563 tree base_binfo;
6575 }
6579 }
6581 /* Returns true if TYPE contains no actual data, just various
6582 possible combinations of empty classes. */
6584 bool
6586 {
6590 {
6591 tree field;
6592 tree binfo;
6593 tree base_binfo;
6606 }
6610 }
6612 /* Note that NAME was looked up while the current class was being
6613 defined and that the result of that lookup was DECL. */
6615 void
6617 {
6618 splay_tree names_used;
6620 /* If we're not defining a class, there's nothing to do. */
6626 /* If there's already a binding for this NAME, then we don't have
6627 anything to worry about. */
6640 }
6642 /* Note that NAME was declared (as DECL) in the current class. Check
6643 to see that the declaration is valid. */
6645 void
6647 {
6648 splay_tree names_used;
6649 splay_tree_node n;
6651 /* Look to see if we ever used this name. */
6652 names_used
6659 {
6660 /* [basic.scope.class]
6662 A name N used in a class S shall refer to the same declaration
6663 in its context and when re-evaluated in the completed scope of
6664 S. */
6668 }
6669 }
6671 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6672 Secondary vtables are merged with primary vtables; this function
6673 will return the VAR_DECL for the primary vtable. */
6675 tree
6677 {
6678 tree decl;
6682 {
6685 }
6689 }
6692 /* Returns the binfo for the primary base of BINFO. If the resulting
6693 BINFO is a virtual base, and it is inherited elsewhere in the
6694 hierarchy, then the returned binfo might not be the primary base of
6695 BINFO in the complete object. Check BINFO_PRIMARY_P or
6696 BINFO_LOST_PRIMARY_P to be sure. */
6698 static tree
6700 {
6701 tree primary_base;
6708 }
6710 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6712 static int
6714 {
6718 }
6720 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6721 INDENT should be zero when called from the top level; it is
6722 incremented recursively. IGO indicates the next expected BINFO in
6723 inheritance graph ordering. */
6725 static tree
6728 tree binfo,
6729 tree igo,
6731 {
6733 tree base_binfo;
6741 {
6744 }
6759 {
6763 TFF_PLAIN_IDENTIFIER),
6765 }
6767 {
6770 }
6775 {
6779 {
6783 TFF_PLAIN_IDENTIFIER));
6784 }
6786 {
6790 TFF_PLAIN_IDENTIFIER));
6791 }
6793 {
6797 TFF_PLAIN_IDENTIFIER));
6798 }
6800 {
6804 TFF_PLAIN_IDENTIFIER));
6805 }
6809 }
6815 }
6817 /* Dump the BINFO hierarchy for T. */
6819 static void
6821 {
6833 }
6835 /* Debug interface to hierarchy dumping. */
6837 void
6839 {
6841 }
6843 static void
6845 {
6850 {
6853 }
6854 }
6856 static void
6858 {
6859 tree value;
6861 HOST_WIDE_INT elt;
6869 TFF_PLAIN_IDENTIFIER));
6876 }
6878 static void
6880 {
6888 {
6895 {
6899 }
6903 }
6906 }
6908 static void
6910 {
6918 {
6923 }
6926 }
6928 /* Dump a function or thunk and its thunkees. */
6930 static void
6932 {
6935 tree thunks;
6943 {
6953 else
6959 }
6963 }
6965 /* Dump the thunks for FN. */
6967 void
6969 {
6971 }
6973 /* Virtual function table initialization. */
6975 /* Create all the necessary vtables for T and its base classes. */
6977 static void
6979 {
6980 tree list;
6981 tree vbase;
6983 /* We lay out the primary and secondary vtables in one contiguous
6984 vtable. The primary vtable is first, followed by the non-virtual
6985 secondary vtables in inheritance graph order. */
6990 /* Then come the virtual bases, also in inheritance graph order. */
6992 {
6996 }
7000 }
7002 /* Initialize the vtable for BINFO with the INITS. */
7004 static void
7006 {
7007 tree decl;
7013 }
7015 /* Build the VTT (virtual table table) for T.
7016 A class requires a VTT if it has virtual bases.
7018 This holds
7019 1 - primary virtual pointer for complete object T
7020 2 - secondary VTTs for each direct non-virtual base of T which requires a
7021 VTT
7022 3 - secondary virtual pointers for each direct or indirect base of T which
7023 has virtual bases or is reachable via a virtual path from T.
7024 4 - secondary VTTs for each direct or indirect virtual base of T.
7026 Secondary VTTs look like complete object VTTs without part 4. */
7028 static void
7030 {
7031 tree inits;
7032 tree type;
7033 tree vtt;
7034 tree index;
7036 /* Build up the initializers for the VTT. */
7041 /* If we didn't need a VTT, we're done. */
7045 /* Figure out the type of the VTT. */
7049 /* Now, build the VTT object itself. */
7052 /* Add the VTT to the vtables list. */
7057 }
7059 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7060 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7061 and CHAIN the vtable pointer for this binfo after construction is
7062 complete. VALUE can also be another BINFO, in which case we recurse. */
7064 static tree
7066 {
7067 tree vt;
7070 {
7076 else
7078 }
7081 }
7083 /* Data for secondary VTT initialization. */
7085 {
7086 /* Is this the primary VTT? */
7089 /* Current index into the VTT. */
7090 tree index;
7092 /* TREE_LIST of initializers built up. */
7093 tree inits;
7095 /* The type being constructed by this secondary VTT. */
7096 tree type_being_constructed;
7099 /* Recursively build the VTT-initializer for BINFO (which is in the
7100 hierarchy dominated by T). INITS points to the end of the initializer
7101 list to date. INDEX is the VTT index where the next element will be
7102 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7103 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7104 for virtual bases of T. When it is not so, we build the constructor
7105 vtables for the BINFO-in-T variant. */
7109 {
7111 tree b;
7112 tree init;
7113 tree secondary_vptrs;
7114 secondary_vptr_vtt_init_data data;
7117 /* We only need VTTs for subobjects with virtual bases. */
7121 /* We need to use a construction vtable if this is not the primary
7122 VTT. */
7124 {
7127 /* Record the offset in the VTT where this sub-VTT can be found. */
7129 }
7131 /* Add the address of the primary vtable for the complete object. */
7136 {
7139 }
7142 /* Recursively add the secondary VTTs for non-virtual bases. */
7147 /* Add secondary virtual pointers for all subobjects of BINFO with
7148 either virtual bases or reachable along a virtual path, except
7149 subobjects that are non-virtual primary bases. */
7159 /* The secondary vptrs come back in reverse order. After we reverse
7160 them, and add the INITS, the last init will be the first element
7161 of the chain. */
7164 {
7168 }
7171 /* Add the secondary VTTs for virtual bases in inheritance graph
7172 order. */
7174 {
7179 }
7180 else
7181 /* Remove the ctor vtables we created. */
7185 }
7187 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
7188 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
7190 static tree
7192 {
7195 /* We don't care about bases that don't have vtables. */
7199 /* We're only interested in proper subobjects of the type being
7200 constructed. */
7204 /* We're only interested in bases with virtual bases or reachable
7205 via a virtual path from the type being constructed. */
7210 /* We're not interested in non-virtual primary bases. */
7214 /* Record the index where this secondary vptr can be found. */
7216 {
7221 {
7222 /* It's a primary virtual base, and this is not a
7223 construction vtable. Find the base this is primary of in
7224 the inheritance graph, and use that base's vtable
7225 now. */
7228 }
7229 }
7231 /* Add the initializer for the secondary vptr itself. */
7234 /* Advance the vtt index. */
7239 }
7241 /* Called from build_vtt_inits via dfs_walk. After building
7242 constructor vtables and generating the sub-vtt from them, we need
7243 to restore the BINFO_VTABLES that were scribbled on. DATA is the
7244 binfo of the base whose sub vtt was generated. */
7246 static tree
7248 {
7252 /* If this class has no vtable, none of its bases do. */
7256 /* This might be a primary base, so have no vtable in this
7257 hierarchy. */
7260 /* If we scribbled the construction vtable vptr into BINFO, clear it
7261 out now. */
7267 }
7269 /* Build the construction vtable group for BINFO which is in the
7270 hierarchy dominated by T. */
7272 static void
7274 {
7275 tree list;
7276 tree type;
7277 tree vtbl;
7278 tree inits;
7279 tree id;
7280 tree vbase;
7282 /* See if we've already created this construction vtable group. */
7288 /* Build a version of VTBL (with the wrong type) for use in
7289 constructing the addresses of secondary vtables in the
7290 construction vtable group. */
7297 /* Add the vtables for each of our virtual bases using the vbase in T
7298 binfo. */
7300 vbase;
7302 {
7303 tree b;
7310 }
7313 /* Figure out the type of the construction vtable. */
7321 /* Initialize the construction vtable. */
7325 }
7327 /* Add the vtbl initializers for BINFO (and its bases other than
7328 non-virtual primaries) to the list of INITS. BINFO is in the
7329 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7330 the constructor the vtbl inits should be accumulated for. (If this
7331 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7332 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7333 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7334 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7335 but are not necessarily the same in terms of layout. */
7337 static void
7339 tree orig_binfo,
7340 tree rtti_binfo,
7341 tree t,
7342 tree inits)
7343 {
7345 tree base_binfo;
7350 /* If it doesn't have a vptr, we don't do anything. */
7354 /* If we're building a construction vtable, we're not interested in
7355 subobjects that don't require construction vtables. */
7361 /* Build the initializers for the BINFO-in-T vtable. */
7367 /* Walk the BINFO and its bases. We walk in preorder so that as we
7368 initialize each vtable we can figure out at what offset the
7369 secondary vtable lies from the primary vtable. We can't use
7370 dfs_walk here because we need to iterate through bases of BINFO
7371 and RTTI_BINFO simultaneously. */
7373 {
7374 /* Skip virtual bases. */
7380 inits);
7381 }
7382 }
7384 /* Called from accumulate_vtbl_inits. Returns the initializers for
7385 the BINFO vtable. */
7387 static tree
7389 tree orig_binfo,
7390 tree rtti_binfo,
7391 tree t,
7392 tree l)
7393 {
7400 {
7401 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7402 primary virtual base. If it is not the same primary in
7403 the hierarchy of T, we'll need to generate a ctor vtable
7404 for it, to place at its location in T. If it is the same
7405 primary, we still need a VTT entry for the vtable, but it
7406 should point to the ctor vtable for the base it is a
7407 primary for within the sub-hierarchy of RTTI_BINFO.
7409 There are three possible cases:
7411 1) We are in the same place.
7412 2) We are a primary base within a lost primary virtual base of
7413 RTTI_BINFO.
7414 3) We are primary to something not a base of RTTI_BINFO. */
7416 tree b;
7419 /* First, look through the bases we are primary to for RTTI_BINFO
7420 or a virtual base. */
7423 {
7428 }
7429 /* If we run out of primary links, keep looking down our
7430 inheritance chain; we might be an indirect primary. */
7434 found:
7436 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7437 base B and it is a base of RTTI_BINFO, this is case 2. In
7438 either case, we share our vtable with LAST, i.e. the
7439 derived-most base within B of which we are a primary. */
7442 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7443 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7444 binfo_ctor_vtable after everything's been set up. */
7447 /* Otherwise, this is case 3 and we get our own. */
7448 }
7453 {
7454 tree index;
7457 /* Compute the initializer for this vtable. */
7461 /* Figure out the position to which the VPTR should point. */
7469 index);
7471 }
7474 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7475 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7476 straighten this out. */
7480 else
7481 /* For an ordinary vtable, set BINFO_VTABLE. */
7485 }
7489 /* Construct the initializer for BINFO's virtual function table. BINFO
7490 is part of the hierarchy dominated by T. If we're building a
7491 construction vtable, the ORIG_BINFO is the binfo we should use to
7492 find the actual function pointers to put in the vtable - but they
7493 can be overridden on the path to most-derived in the graph that
7494 ORIG_BINFO belongs. Otherwise,
7495 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7496 BINFO that should be indicated by the RTTI information in the
7497 vtable; it will be a base class of T, rather than T itself, if we
7498 are building a construction vtable.
7500 The value returned is a TREE_LIST suitable for wrapping in a
7501 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7502 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7503 number of non-function entries in the vtable.
7505 It might seem that this function should never be called with a
7506 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7507 base is always subsumed by a derived class vtable. However, when
7508 we are building construction vtables, we do build vtables for
7509 primary bases; we need these while the primary base is being
7510 constructed. */
7512 static tree
7514 tree orig_binfo,
7515 tree t,
7516 tree rtti_binfo,
7518 {
7520 tree vfun_inits;
7521 vtbl_init_data vid;
7523 tree vbinfo;
7526 /* Initialize VID. */
7535 /* The first vbase or vcall offset is at index -3 in the vtable. */
7538 /* Add entries to the vtable for RTTI. */
7541 /* Create an array for keeping track of the functions we've
7542 processed. When we see multiple functions with the same
7543 signature, we share the vcall offsets. */
7545 /* Add the vcall and vbase offset entries. */
7548 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7549 build_vbase_offset_vtbl_entries. */
7554 /* If the target requires padding between data entries, add that now. */
7556 {
7560 {
7567 null_pointer_node),
7568 add);
7570 }
7571 }
7576 /* Go through all the ordinary virtual functions, building up
7577 initializers. */
7580 {
7581 tree delta;
7582 tree vcall_index;
7589 {
7593 {
7596 }
7598 }
7600 /* If the only definition of this function signature along our
7601 primary base chain is from a lost primary, this vtable slot will
7602 never be used, so just zero it out. This is important to avoid
7603 requiring extra thunks which cannot be generated with the function.
7605 We first check this in update_vtable_entry_for_fn, so we handle
7606 restored primary bases properly; we also need to do it here so we
7607 zero out unused slots in ctor vtables, rather than filling them
7608 with erroneous values (though harmless, apart from relocation
7609 costs). */
7611 {
7612 /* We found a defn before a lost primary; go ahead as normal. */
7616 /* The nearest definition is from a lost primary; clear the
7617 slot. */
7619 {
7622 }
7623 }
7626 {
7627 /* Pull the offset for `this', and the function to call, out of
7628 the list. */
7635 /* You can't call an abstract virtual function; it's abstract.
7636 So, we replace these functions with __pure_virtual. */
7638 {
7643 }
7644 else
7645 {
7647 {
7651 }
7652 /* Take the address of the function, considering it to be of an
7653 appropriate generic type. */
7655 }
7656 }
7658 /* And add it to the chain of initializers. */
7660 {
7665 else
7667 {
7674 }
7675 }
7676 else
7678 }
7680 /* The initializers for virtual functions were built up in reverse
7681 order; straighten them out now. */
7684 /* The negative offset initializers are also in reverse order. */
7687 /* Chain the two together. */
7689 }
7691 /* Adds to vid->inits the initializers for the vbase and vcall
7692 offsets in BINFO, which is in the hierarchy dominated by T. */
7694 static void
7696 {
7697 tree b;
7699 /* If this is a derived class, we must first create entries
7700 corresponding to the primary base class. */
7705 /* Add the vbase entries for this base. */
7707 /* Add the vcall entries for this base. */
7709 }
7711 /* Returns the initializers for the vbase offset entries in the vtable
7712 for BINFO (which is part of the class hierarchy dominated by T), in
7713 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7714 where the next vbase offset will go. */
7716 static void
7718 {
7719 tree vbase;
7720 tree t;
7721 tree non_primary_binfo;
7723 /* If there are no virtual baseclasses, then there is nothing to
7724 do. */
7730 /* We might be a primary base class. Go up the inheritance hierarchy
7731 until we find the most derived class of which we are a primary base:
7732 it is the offset of that which we need to use. */
7735 {
7736 tree b;
7738 /* If we have reached a virtual base, then it must be a primary
7739 base (possibly multi-level) of vid->binfo, or we wouldn't
7740 have called build_vcall_and_vbase_vtbl_entries for it. But it
7741 might be a lost primary, so just skip down to vid->binfo. */
7743 {
7746 }
7752 }
7754 /* Go through the virtual bases, adding the offsets. */
7756 vbase;
7758 {
7759 tree b;
7760 tree delta;
7765 /* Find the instance of this virtual base in the complete
7766 object. */
7769 /* If we've already got an offset for this virtual base, we
7770 don't need another one. */
7775 /* Figure out where we can find this vbase offset. */
7784 /* The vbase offset had better be the same. */
7787 /* The next vbase will come at a more negative offset. */
7791 /* The initializer is the delta from BINFO to this virtual base.
7792 The vbase offsets go in reverse inheritance-graph order, and
7793 we are walking in inheritance graph order so these end up in
7794 the right order. */
7801 vtable_entry_type,
7802 delta));
7804 }
7805 }
7807 /* Adds the initializers for the vcall offset entries in the vtable
7808 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7809 to VID->INITS. */
7811 static void
7813 {
7814 /* We only need these entries if this base is a virtual base. We
7815 compute the indices -- but do not add to the vtable -- when
7816 building the main vtable for a class. */
7819 /* If BINFO is RTTI_BINFO, then (since BINFO does not
7820 correspond to VID->DERIVED), we are building a primary
7821 construction virtual table. Since this is a primary
7822 virtual table, we do not need the vcall offsets for
7823 BINFO. */
7825 {
7826 /* We need a vcall offset for each of the virtual functions in this
7827 vtable. For example:
7829 class A { virtual void f (); };
7830 class B1 : virtual public A { virtual void f (); };
7831 class B2 : virtual public A { virtual void f (); };
7832 class C: public B1, public B2 { virtual void f (); };
7834 A C object has a primary base of B1, which has a primary base of A. A
7835 C also has a secondary base of B2, which no longer has a primary base
7836 of A. So the B2-in-C construction vtable needs a secondary vtable for
7837 A, which will adjust the A* to a B2* to call f. We have no way of
7838 knowing what (or even whether) this offset will be when we define B2,
7839 so we store this "vcall offset" in the A sub-vtable and look it up in
7840 a "virtual thunk" for B2::f.
7842 We need entries for all the functions in our primary vtable and
7843 in our non-virtual bases' secondary vtables. */
7845 /* If we are just computing the vcall indices -- but do not need
7846 the actual entries -- not that. */
7849 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7851 }
7852 }
7854 /* Build vcall offsets, starting with those for BINFO. */
7856 static void
7858 {
7860 tree primary_binfo;
7861 tree base_binfo;
7863 /* Don't walk into virtual bases -- except, of course, for the
7864 virtual base for which we are building vcall offsets. Any
7865 primary virtual base will have already had its offsets generated
7866 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7870 /* If BINFO has a primary base, process it first. */
7875 /* Add BINFO itself to the list. */
7878 /* Scan the non-primary bases of BINFO. */
7882 }
7884 /* Called from build_vcall_offset_vtbl_entries_r. */
7886 static void
7888 {
7889 /* Make entries for the rest of the virtuals. */
7891 {
7892 tree orig_fn;
7894 /* The ABI requires that the methods be processed in declaration
7895 order. G++ 3.2 used the order in the vtable. */
7897 orig_fn;
7901 }
7902 else
7903 {
7904 tree derived_virtuals;
7905 tree base_virtuals;
7906 tree orig_virtuals;
7907 /* If BINFO is a primary base, the most derived class which has
7908 BINFO as a primary base; otherwise, just BINFO. */
7909 tree non_primary_binfo;
7911 /* We might be a primary base class. Go up the inheritance hierarchy
7912 until we find the most derived class of which we are a primary base:
7913 it is the BINFO_VIRTUALS there that we need to consider. */
7916 {
7917 tree b;
7919 /* If we have reached a virtual base, then it must be vid->vbase,
7920 because we ignore other virtual bases in
7921 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7922 base (possibly multi-level) of vid->binfo, or we wouldn't
7923 have called build_vcall_and_vbase_vtbl_entries for it. But it
7924 might be a lost primary, so just skip down to vid->binfo. */
7926 {
7930 }
7936 }
7939 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7940 where rtti_binfo is the most derived type. */
7941 non_primary_binfo
7947 base_virtuals;
7951 {
7952 tree orig_fn;
7954 /* Find the declaration that originally caused this function to
7955 be present in BINFO_TYPE (binfo). */
7958 /* When processing BINFO, we only want to generate vcall slots for
7959 function slots introduced in BINFO. So don't try to generate
7960 one if the function isn't even defined in BINFO. */
7965 }
7966 }
7967 }
7969 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7971 static void
7973 {
7975 tree vcall_offset;
7976 tree derived_entry;
7978 /* If there is already an entry for a function with the same
7979 signature as FN, then we do not need a second vcall offset.
7980 Check the list of functions already present in the derived
7981 class vtable. */
7983 {
7985 /* We only use one vcall offset for virtual destructors,
7986 even though there are two virtual table entries. */
7990 }
7992 /* If we are building these vcall offsets as part of building
7993 the vtable for the most derived class, remember the vcall
7994 offset. */
7996 {
7999 NULL);
8002 }
8004 /* The next vcall offset will be found at a more negative
8005 offset. */
8009 /* Keep track of this function. */
8013 {
8014 tree base;
8015 tree fn;
8017 /* Find the overriding function. */
8021 integer_zero_node);
8022 else
8023 {
8026 /* The vbase we're working on is a primary base of
8027 vid->binfo. But it might be a lost primary, so its
8028 BINFO_OFFSET might be wrong, so we just use the
8029 BINFO_OFFSET from vid->binfo. */
8035 vcall_offset);
8036 }
8037 /* Add the initializer to the vtable. */
8040 }
8041 }
8043 /* Return vtbl initializers for the RTTI entries corresponding to the
8044 BINFO's vtable. The RTTI entries should indicate the object given
8045 by VID->rtti_binfo. */
8047 static void
8049 {
8050 tree b;
8051 tree t;
8052 tree basetype;
8053 tree offset;
8054 tree decl;
8055 tree init;
8060 /* To find the complete object, we will first convert to our most
8061 primary base, and then add the offset in the vtbl to that value. */
8065 {
8066 tree primary_base;
8072 }
8076 /* The second entry is the address of the typeinfo object. */
8079 else
8082 /* Convert the declaration to a type that can be stored in the
8083 vtable. */
8088 /* Add the offset-to-top entry. It comes earlier in the vtable than
8089 the typeinfo entry. Convert the offset to look like a
8090 function pointer, so that we can put it in the vtable. */
8094 }
8096 /* Fold a OBJ_TYPE_REF expression to the address of a function.
8097 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
8099 tree
8101 {
8105 tree fndecl;
8108 {
8109 i += (TARGET_VTABLE_USES_DESCRIPTORS
8112 }
8116 #ifdef ENABLE_CHECKING
8119 #endif
8124 }