| blob | fd0f011d0aedceea0fbf5401b61fd554e7ca93e9 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
4 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
12 any later version.
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
24 /* High-level class interface. */
42 /* The number of nested classes being processed. If we are not in the
43 scope of any class, this is zero. */
47 /* In order to deal with nested classes, we keep a stack of classes.
48 The topmost entry is the innermost class, and is the entry at index
49 CURRENT_CLASS_DEPTH */
52 /* The name of the class. */
53 tree name;
55 /* The _TYPE node for the class. */
56 tree type;
58 /* The access specifier pending for new declarations in the scope of
59 this class. */
60 tree access;
62 /* If were defining TYPE, the names used in this class. */
63 splay_tree names_used;
65 /* Nonzero if this class is no longer open, because of a call to
66 push_to_top_level. */
71 {
72 /* The base for which we're building initializers. */
73 tree binfo;
74 /* The type of the most-derived type. */
75 tree derived;
76 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
77 unless ctor_vtbl_p is true. */
78 tree rtti_binfo;
79 /* The negative-index vtable initializers built up so far. These
80 are in order from least negative index to most negative index. */
82 /* The binfo for the virtual base for which we're building
83 vcall offset initializers. */
84 tree vbase;
85 /* The functions in vbase for which we have already provided vcall
86 offsets. */
88 /* The vtable index of the next vcall or vbase offset. */
89 tree index;
90 /* Nonzero if we are building the initializer for the primary
91 vtable. */
93 /* Nonzero if we are building the initializer for a construction
94 vtable. */
96 /* True when adding vcall offset entries to the vtable. False when
97 merely computing the indices. */
101 /* The type of a function passed to walk_subobject_offsets. */
104 /* The stack itself. This is a dynamically resized array. The
105 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
109 /* The size of the largest empty class seen in this translation unit. */
112 /* An array of all local classes present in this translation unit, in
113 declaration order. */
203 splay_tree_key k2);
212 /* Variables shared between class.c and call.c. */
214 #ifdef GATHER_STATISTICS
222 #endif
224 /* Convert to or from a base subobject. EXPR is an expression of type
225 `A' or `A*', an expression of type `B' or `B*' is returned. To
226 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
227 the B base instance within A. To convert base A to derived B, CODE
228 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
229 In this latter case, A must not be a morally virtual base of B.
230 NONNULL is true if EXPR is known to be non-NULL (this is only
231 needed when EXPR is of pointer type). CV qualifiers are preserved
232 from EXPR. */
234 tree
236 tree expr,
237 tree binfo,
239 {
242 tree probe;
243 tree offset;
244 tree target_type;
246 tree ptr_target_type;
256 {
262 }
274 /* Nothing to do. */
278 {
282 }
285 /* This must happen before the call to save_expr. */
287 else
293 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
294 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
295 expression returned matches the input. */
296 target_type = cp_build_qualified_type
300 /* Do we need to look in the vtable for the real offset? */
303 /* Don't bother with the calculations inside sizeof; they'll ICE if the
304 source type is incomplete and the pointer value doesn't matter. */
306 {
311 }
313 /* Do we need to check for a null pointer? */
315 {
316 /* If we know the conversion will not actually change the value
317 of EXPR, then we can avoid testing the expression for NULL.
318 We have to avoid generating a COMPONENT_REF for a base class
319 field, because other parts of the compiler know that such
320 expressions are always non-NULL. */
324 }
326 /* Protect against multiple evaluation if necessary. */
330 /* Now that we've saved expr, build the real null test. */
332 {
336 }
338 /* If this is a simple base reference, express it as a COMPONENT_REF. */
340 /* We don't build base fields for empty bases, and they aren't very
341 interesting to the optimizers anyway. */
343 {
350 }
353 {
354 /* Going via virtual base V_BINFO. We need the static offset
355 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
356 V_BINFO. That offset is an entry in D_BINFO's vtable. */
357 tree v_offset;
360 {
361 /* In a base member initializer, we cannot rely on the
362 vtable being set up. We have to indirect via the
363 vtt_parm. */
364 tree t;
370 tf_warning_or_error);
371 }
372 else
374 tf_warning_or_error),
380 v_offset);
392 /* Negative fixed_type_p means this is a constructor or destructor;
393 virtual base layout is fixed in in-charge [cd]tors, but not in
394 base [cd]tors. */
398 v_offset,
401 else
403 }
411 {
416 }
417 else
423 out:
429 }
431 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
432 Perform a derived-to-base conversion by recursively building up a
433 sequence of COMPONENT_REFs to the appropriate base fields. */
435 static tree
437 {
440 tree field;
443 {
444 tree temp;
448 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
449 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
450 an lvalue in the front end; only _DECLs and _REFs are lvalues
451 in the back end. */
457 }
459 /* Recurse. */
464 /* Is this the base field created by build_base_field? */
468 {
469 /* We don't use build_class_member_access_expr here, as that
470 has unnecessary checks, and more importantly results in
471 recursive calls to dfs_walk_once. */
479 /* Mark the expression const or volatile, as appropriate.
480 Even though we've dealt with the type above, we still have
481 to mark the expression itself. */
488 }
490 /* Didn't find the base field?!? */
492 }
494 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
495 type is a class type or a pointer to a class type. In the former
496 case, TYPE is also a class type; in the latter it is another
497 pointer type. If CHECK_ACCESS is true, an error message is emitted
498 if TYPE is inaccessible. If OBJECT has pointer type, the value is
499 assumed to be non-NULL. */
501 tree
503 tsubst_flags_t complain)
504 {
505 tree binfo;
506 tree object_type;
507 base_access access;
510 {
513 }
514 else
521 access,
522 NULL);
527 }
529 /* EXPR is an expression with unqualified class type. BASE is a base
530 binfo of that class type. Returns EXPR, converted to the BASE
531 type. This function assumes that EXPR is the most derived class;
532 therefore virtual bases can be found at their static offsets. */
534 tree
536 {
537 tree expr_type;
541 {
542 /* We use fold_build2 and fold_convert below to simplify the trees
543 provided to the optimizers. It is not safe to call these functions
544 when processing a template because they do not handle C++-specific
545 trees. */
553 }
556 }
558 \f
559 tree
561 {
567 /* First, convert to the requested type. */
572 /* Second, the requested type may not be the owner of its own vptr.
573 If not, convert to the base class that owns it. We cannot use
574 convert_to_base here, because VCONTEXT may appear more than once
575 in the inheritance hierarchy of TYPE, and thus direct conversion
576 between the types may be ambiguous. Following the path back up
577 one step at a time via primary bases avoids the problem. */
581 {
584 }
587 }
589 /* Given an object INSTANCE, return an expression which yields the
590 vtable element corresponding to INDEX. There are many special
591 cases for INSTANCE which we take care of here, mainly to avoid
592 creating extra tree nodes when we don't have to. */
594 static tree
596 {
597 tree aref;
600 /* Try to figure out what a reference refers to, and
601 access its virtual function table directly. */
609 {
614 }
623 }
625 tree
627 {
631 }
633 /* Given a stable object pointer INSTANCE_PTR, return an expression which
634 yields a function pointer corresponding to vtable element INDEX. */
636 tree
638 {
639 tree aref;
642 tf_warning_or_error),
643 idx);
645 /* When using function descriptors, the address of the
646 vtable entry is treated as a function pointer. */
651 /* Remember this as a method reference, for later devirtualization. */
655 }
657 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
658 for the given TYPE. */
660 static tree
662 {
664 }
666 /* DECL is an entity associated with TYPE, like a virtual table or an
667 implicitly generated constructor. Determine whether or not DECL
668 should have external or internal linkage at the object file
669 level. This routine does not deal with COMDAT linkage and other
670 similar complexities; it simply sets TREE_PUBLIC if it possible for
671 entities in other translation units to contain copies of DECL, in
672 the abstract. */
674 void
676 {
679 }
681 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
682 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
683 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
685 static tree
687 {
688 tree decl;
691 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
692 now to avoid confusion in mangle_decl. */
701 /* At one time the vtable info was grabbed 2 words at a time. This
702 fails on sparc unless you have 8-byte alignment. (tiemann) */
706 /* The vtable has not been defined -- yet. */
710 /* Mark the VAR_DECL node representing the vtable itself as a
711 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
712 is rather important that such things be ignored because any
713 effort to actually generate DWARF for them will run into
714 trouble when/if we encounter code like:
716 #pragma interface
717 struct S { virtual void member (); };
719 because the artificial declaration of the vtable itself (as
720 manufactured by the g++ front end) will say that the vtable is
721 a static member of `S' but only *after* the debug output for
722 the definition of `S' has already been output. This causes
723 grief because the DWARF entry for the definition of the vtable
724 will try to refer back to an earlier *declaration* of the
725 vtable as a static member of `S' and there won't be one. We
726 might be able to arrange to have the "vtable static member"
727 attached to the member list for `S' before the debug info for
728 `S' get written (which would solve the problem) but that would
729 require more intrusive changes to the g++ front end. */
733 }
735 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
736 or even complete. If this does not exist, create it. If COMPLETE is
737 nonzero, then complete the definition of it -- that will render it
738 impossible to actually build the vtable, but is useful to get at those
739 which are known to exist in the runtime. */
741 tree
743 {
744 tree decl;
753 {
756 }
759 }
761 /* Build the primary virtual function table for TYPE. If BINFO is
762 non-NULL, build the vtable starting with the initial approximation
763 that it is the same as the one which is the head of the association
764 list. Returns a nonzero value if a new vtable is actually
765 created. */
767 static int
769 {
770 tree decl;
771 tree virtuals;
776 {
778 /* We have already created a vtable for this base, so there's
779 no need to do it again. */
786 }
787 else
788 {
791 }
793 #ifdef GATHER_STATISTICS
796 #endif
798 /* Initialize the association list for this type, based
799 on our first approximation. */
804 }
806 /* Give BINFO a new virtual function table which is initialized
807 with a skeleton-copy of its original initialization. The only
808 entry that changes is the `delta' entry, so we can really
809 share a lot of structure.
811 FOR_TYPE is the most derived type which caused this table to
812 be needed.
814 Returns nonzero if we haven't met BINFO before.
816 The order in which vtables are built (by calling this function) for
817 an object must remain the same, otherwise a binary incompatibility
818 can result. */
820 static int
822 {
824 /* We already created a vtable for this base. There's no need to
825 do it again. */
828 /* Remember that we've created a vtable for this BINFO, so that we
829 don't try to do so again. */
832 /* Make fresh virtual list, so we can smash it later. */
835 /* Secondary vtables are laid out as part of the same structure as
836 the primary vtable. */
839 }
841 /* Create a new vtable for BINFO which is the hierarchy dominated by
842 T. Return nonzero if we actually created a new vtable. */
844 static int
846 {
848 /* In this case, it is *type*'s vtable we are modifying. We start
849 with the approximation that its vtable is that of the
850 immediate base class. */
852 else
853 /* This is our very own copy of `basetype' to play with. Later,
854 we will fill in all the virtual functions that override the
855 virtual functions in these base classes which are not defined
856 by the current type. */
858 }
860 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
861 (which is in the hierarchy dominated by T) list FNDECL as its
862 BV_FN. DELTA is the required constant adjustment from the `this'
863 pointer where the vtable entry appears to the `this' required when
864 the function is actually called. */
866 static void
868 tree binfo,
869 tree fndecl,
870 tree delta,
872 {
873 tree v;
879 {
880 /* We need a new vtable for BINFO. */
882 {
883 /* If we really did make a new vtable, we also made a copy
884 of the BINFO_VIRTUALS list. Now, we have to find the
885 corresponding entry in that list. */
890 }
895 }
896 }
898 \f
899 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
900 the USING_DECL naming METHOD. Returns true if the method could be
901 added to the method vec. */
903 bool
905 {
907 tree overload;
913 tree current_fns;
914 tree fns;
927 {
928 /* Make a new method vector. We start with 8 entries. We must
929 allocate at least two (for constructors and destructors), and
930 we're going to end up with an assignment operator at some
931 point as well. */
933 /* Create slots for constructors and destructors. */
937 }
939 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
942 /* Constructors and destructors go in special slots. */
946 {
950 {
956 type);
957 }
958 }
959 else
960 {
961 tree m;
964 /* See if we already have an entry with this name. */
968 {
971 {
976 }
980 {
983 }
988 }
989 }
992 /* Check to see if we've already got this method. */
994 {
996 tree fn_type;
997 tree method_type;
998 tree parms1;
999 tree parms2;
1004 /* [over.load] Member function declarations with the
1005 same name and the same parameter types cannot be
1006 overloaded if any of them is a static member
1007 function declaration.
1009 [namespace.udecl] When a using-declaration brings names
1010 from a base class into a derived class scope, member
1011 functions in the derived class override and/or hide member
1012 functions with the same name and parameter types in a base
1013 class (rather than conflicting). */
1019 /* Compare the quals on the 'this' parm. Don't compare
1020 the whole types, as used functions are treated as
1021 coming from the using class in overload resolution. */
1030 /* For templates, the return type and template parameters
1031 must be identical. */
1048 {
1050 {
1052 /* Defer to the local function. */
1056 else
1058 using_decl);
1059 }
1060 else
1061 {
1064 }
1066 /* We don't call duplicate_decls here to merge the
1067 declarations because that will confuse things if the
1068 methods have inline definitions. In particular, we
1069 will crash while processing the definitions. */
1071 }
1072 }
1074 /* A class should never have more than one destructor. */
1078 /* Add the new binding. */
1087 {
1090 /* We only expect to add few methods in the COMPLETE_P case, so
1091 just make room for one more method in that case. */
1094 else
1100 else
1102 }
1103 else
1104 /* Replace the current slot. */
1107 }
1109 /* Subroutines of finish_struct. */
1111 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1112 legit, otherwise return 0. */
1114 static int
1116 {
1117 tree elem;
1126 {
1128 {
1132 else
1135 }
1136 else
1137 {
1138 /* They're changing the access to the same thing they changed
1139 it to before. That's OK. */
1140 ;
1141 }
1142 }
1143 else
1144 {
1148 }
1150 }
1152 /* Process the USING_DECL, which is a member of T. */
1154 static void
1156 {
1159 tree access
1164 tree old_value;
1170 {
1176 else
1178 }
1186 ;
1188 {
1190 /* It's OK to use functions from a base when there are functions with
1192 else
1193 {
1198 }
1199 }
1201 {
1205 }
1207 /* Make type T see field decl FDECL with access ACCESS. */
1210 {
1213 }
1214 else
1216 }
1217 \f
1218 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1219 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1220 properties of the bases. */
1222 static void
1226 {
1229 tree base_binfo;
1230 tree binfo;
1242 {
1251 /* If any base class is non-literal, so is the derived class. */
1255 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1256 here because the case of virtual functions but non-virtual
1257 dtor is handled in finish_struct_1. */
1262 /* If the base class doesn't have copy constructors or
1263 assignment operators that take const references, then the
1264 derived class cannot have such a member automatically
1265 generated. */
1274 /* A virtual base does not effect nearly emptiness. */
1275 ;
1277 {
1279 /* And if there is more than one nearly empty base, then the
1280 derived class is not nearly empty either. */
1282 else
1283 /* Remember we've seen one. */
1285 }
1287 /* If the base class is not empty or nearly empty, then this
1288 class cannot be nearly empty. */
1291 /* A lot of properties from the bases also apply to the derived
1292 class. */
1310 /* A standard-layout class is a class that:
1311 ...
1312 * has no non-standard-layout base classes, */
1315 {
1316 tree basefield;
1317 /* ...has no base classes of the same type as the first non-static
1318 data member... */
1320 && (same_type_ignoring_top_level_qualifiers_p
1323 else
1324 /* ...either has no non-static data members in the most-derived
1325 class and at most one base class with non-static data
1326 members, or has no base classes with non-static data
1327 members */
1331 {
1334 else
1337 }
1338 }
1339 }
1340 }
1342 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1343 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1344 that have had a nearly-empty virtual primary base stolen by some
1345 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1346 T. */
1348 static void
1350 {
1354 tree base_binfo;
1356 /* Determine the primary bases of our bases. */
1359 {
1362 /* See if we're the non-virtual primary of our inheritance
1363 chain. */
1365 {
1372 /* We are the primary binfo. */
1374 }
1375 /* Determine if we have a virtual primary base, and mark it so.
1376 */
1378 {
1382 /* Someone already claimed this base. */
1384 else
1385 {
1386 tree delta;
1391 /* A virtual binfo might have been copied from within
1392 another hierarchy. As we're about to use it as a
1393 primary base, make sure the offsets match. */
1401 }
1402 }
1403 }
1405 /* First look for a dynamic direct non-virtual base. */
1407 {
1411 {
1414 }
1415 }
1417 /* A "nearly-empty" virtual base class can be the primary base
1418 class, if no non-virtual polymorphic base can be found. Look for
1419 a nearly-empty virtual dynamic base that is not already a primary
1420 base of something in the hierarchy. If there is no such base,
1421 just pick the first nearly-empty virtual base. */
1427 {
1429 {
1430 /* Found one that is not primary. */
1433 }
1435 /* Remember the first candidate. */
1437 }
1439 found:
1440 /* If we've got a primary base, use it. */
1442 {
1447 /* We are stealing a primary base. */
1451 {
1452 tree delta;
1455 /* A virtual binfo might have been copied from within
1456 another hierarchy. As we're about to use it as a primary
1457 base, make sure the offsets match. */
1462 }
1469 }
1470 }
1472 /* Update the variant types of T. */
1474 void
1476 {
1477 tree variants;
1483 variants;
1485 {
1486 /* These fields are in the _TYPE part of the node, not in
1487 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1497 /* Copy whatever these are holding today. */
1501 }
1502 }
1504 /* Early variant fixups: we apply attributes at the beginning of the class
1505 definition, and we need to fix up any variants that have already been
1506 made via elaborated-type-specifier so that check_qualified_type works. */
1508 void
1510 {
1511 tree variants;
1517 variants;
1519 {
1520 /* These are the two fields that check_qualified_type looks at and
1521 are affected by attributes. */
1524 }
1525 }
1526 \f
1527 /* Set memoizing fields and bits of T (and its variants) for later
1528 use. */
1530 static void
1532 {
1533 /* Fix up variants (if any). */
1537 /* For a class w/o baseclasses, 'finish_struct' has set
1538 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1539 Similarly for a class whose base classes do not have vtables.
1540 When neither of these is true, we might have removed abstract
1541 virtuals (by providing a definition), added some (by declaring
1542 new ones), or redeclared ones from a base class. We need to
1543 recalculate what's really an abstract virtual at this point (by
1544 looking in the vtables). */
1547 /* If this type has a copy constructor or a destructor, force its
1548 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1549 nonzero. This will cause it to be passed by invisible reference
1550 and prevent it from being returned in a register. */
1553 {
1554 tree variants;
1557 {
1560 }
1561 }
1562 }
1564 /* Issue warnings about T having private constructors, but no friends,
1565 and so forth.
1567 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1568 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1569 non-private static member functions. */
1571 static void
1573 {
1576 tree fn;
1579 /* If the class has friends, those entities might create and
1580 access instances, so we should not warn. */
1583 /* We will have warned when the template was declared; there's
1584 no need to warn on every instantiation. */
1586 /* There's no reason to even consider warning about this
1587 class. */
1590 /* We only issue one warning, if more than one applies, because
1591 otherwise, on code like:
1593 class A {
1594 // Oops - forgot `public:'
1595 A();
1596 A(const A&);
1597 ~A();
1598 };
1600 we warn several times about essentially the same problem. */
1602 /* Check to see if all (non-constructor, non-destructor) member
1603 functions are private. (Since there are no friends or
1604 non-private statics, we can't ever call any of the private member
1605 functions.) */
1607 /* We're not interested in compiler-generated methods; they don't
1608 provide any way to call private members. */
1610 {
1612 {
1614 /* A non-private static member function is just like a
1615 friend; it can create and invoke private member
1616 functions, and be accessed without a class
1617 instance. */
1621 /* Keep searching for a static member function. */
1622 }
1625 }
1628 {
1629 /* There are no non-private methods, and there's at least one
1630 private member function that isn't a constructor or
1631 destructor. (If all the private members are
1632 constructors/destructors we want to use the code below that
1633 issues error messages specifically referring to
1634 constructors/destructors.) */
1640 {
1643 }
1645 {
1649 }
1650 }
1652 /* Even if some of the member functions are non-private, the class
1653 won't be useful for much if all the constructors or destructors
1654 are private: such an object can never be created or destroyed. */
1657 {
1660 t);
1662 }
1664 /* Warn about classes that have private constructors and no friends. */
1666 /* Implicitly generated constructors are always public. */
1669 {
1672 /* If a non-template class does not define a copy
1673 constructor, one is defined for it, enabling it to avoid
1674 this warning. For a template class, this does not
1675 happen, and so we would normally get a warning on:
1677 template <class T> class C { private: C(); };
1679 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1680 complete non-template or fully instantiated classes have this
1681 flag set. */
1684 else
1686 {
1688 /* Ideally, we wouldn't count copy constructors (or, in
1689 fact, any constructor that takes an argument of the
1690 class type as a parameter) because such things cannot
1691 be used to construct an instance of the class unless
1692 you already have one. But, for now at least, we're
1693 more generous. */
1695 {
1698 }
1699 }
1702 {
1705 t);
1707 }
1708 }
1709 }
1712 gt_pointer_operator new_value;
1716 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1718 static int
1720 {
1733 }
1735 /* This routine compares two fields like method_name_cmp but using the
1736 pointer operator in resort_field_decl_data. */
1738 static int
1740 {
1749 {
1756 }
1758 }
1760 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1762 void
1765 gt_pointer_operator new_value,
1767 {
1771 tree fn;
1773 /* The type conversion ops have to live at the front of the vec, so we
1774 can't sort them. */
1782 {
1786 resort_method_name_cmp);
1787 }
1788 }
1790 /* Warn about duplicate methods in fn_fields.
1792 Sort methods that are not special (i.e., constructors, destructors,
1793 and type conversion operators) so that we can find them faster in
1794 search. */
1796 static void
1798 {
1799 tree fn_fields;
1809 /* Clear DECL_IN_AGGR_P for all functions. */
1814 /* Issue warnings about private constructors and such. If there are
1815 no methods, then some public defaults are generated. */
1818 /* The type conversion ops have to live at the front of the vec, so we
1819 can't sort them. */
1828 }
1830 /* Make BINFO's vtable have N entries, including RTTI entries,
1831 vbase and vcall offsets, etc. Set its type and call the back end
1832 to lay it out. */
1834 static void
1836 {
1837 tree atype;
1838 tree vtable;
1843 /* We may have to grow the vtable. */
1846 {
1850 }
1851 }
1853 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1854 have the same signature. */
1856 int
1858 {
1859 /* One destructor overrides another if they are the same kind of
1860 destructor. */
1864 /* But a non-destructor never overrides a destructor, nor vice
1865 versa, nor do different kinds of destructors override
1866 one-another. For example, a complete object destructor does not
1867 override a deleting destructor. */
1876 {
1884 }
1886 }
1888 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1889 subobject. */
1891 static bool
1893 {
1894 tree probe;
1897 {
1901 /* If we meet a virtual base, we can't follow the inheritance
1902 any more. See if the complete type of DERIVED contains
1903 such a virtual base. */
1906 }
1908 }
1911 /* The function for which we are trying to find a final overrider. */
1912 tree fn;
1913 /* The base class in which the function was declared. */
1914 tree declaring_base;
1915 /* The candidate overriders. */
1916 tree candidates;
1917 /* Path to most derived. */
1921 /* Add the overrider along the current path to FFOD->CANDIDATES.
1922 Returns true if an overrider was found; false otherwise. */
1924 static bool
1928 {
1929 tree method;
1931 /* If BINFO is not the most derived type, try a more derived class.
1932 A definition there will overrider a definition here. */
1934 {
1935 depth--;
1939 }
1943 {
1946 /* Remove any candidates overridden by this new function. */
1948 {
1949 /* If *CANDIDATE overrides METHOD, then METHOD
1950 cannot override anything else on the list. */
1953 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1956 else
1958 }
1960 /* Add the new function. */
1963 }
1966 }
1968 /* Called from find_final_overrider via dfs_walk. */
1970 static tree
1972 {
1980 }
1982 static tree
1984 {
1989 }
1991 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1992 FN and whose TREE_VALUE is the binfo for the base where the
1993 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1994 DERIVED) is the base object in which FN is declared. */
1996 static tree
1998 {
1999 find_final_overrider_data ffod;
2001 /* Getting this right is a little tricky. This is valid:
2003 struct S { virtual void f (); };
2004 struct T { virtual void f (); };
2005 struct U : public S, public T { };
2007 even though calling `f' in `U' is ambiguous. But,
2009 struct R { virtual void f(); };
2010 struct S : virtual public R { virtual void f (); };
2011 struct T : virtual public R { virtual void f (); };
2012 struct U : public S, public T { };
2014 is not -- there's no way to decide whether to put `S::f' or
2015 `T::f' in the vtable for `R'.
2017 The solution is to look at all paths to BINFO. If we find
2018 different overriders along any two, then there is a problem. */
2022 /* Determine the depth of the hierarchy. */
2033 /* If there was no winner, issue an error message. */
2038 }
2040 /* Return the index of the vcall offset for FN when TYPE is used as a
2041 virtual base. */
2043 static tree
2045 {
2047 tree_pair_p p;
2055 /* There should always be an appropriate index. */
2057 }
2059 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2060 dominated by T. FN is the old function; VIRTUALS points to the
2061 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2062 of that entry in the list. */
2064 static void
2067 {
2068 tree b;
2069 tree overrider;
2070 tree delta;
2071 tree virtual_base;
2072 tree first_defn;
2078 /* Find the nearest primary base (possibly binfo itself) which defines
2079 this function; this is the class the caller will convert to when
2080 calling FN through BINFO. */
2082 {
2087 /* The nearest definition is from a lost primary. */
2090 }
2093 /* Find the final overrider. */
2096 {
2099 }
2102 /* Check for adjusting covariant return types. */
2110 /* If the overrider is invalid, don't even try. */
2112 {
2113 /* If FN is a covariant thunk, we must figure out the adjustment
2114 to the final base FN was converting to. As OVERRIDER_TARGET might
2115 also be converting to the return type of FN, we have to
2116 combine the two conversions here. */
2123 {
2127 }
2128 else
2132 /* Find the equivalent binfo within the return type of the
2133 overriding function. We will want the vbase offset from
2134 there. */
2136 over_return);
2139 {
2140 /* There was no existing virtual thunk (which takes
2141 precedence). So find the binfo of the base function's
2142 return type within the overriding function's return type.
2143 We cannot call lookup base here, because we're inside a
2144 dfs_walk, and will therefore clobber the BINFO_MARKED
2145 flags. Fortunately we know the covariancy is valid (it
2146 has already been checked), so we can just iterate along
2147 the binfos, which have been chained in inheritance graph
2148 order. Of course it is lame that we have to repeat the
2149 search here anyway -- we should really be caching pieces
2150 of the vtable and avoiding this repeated work. */
2153 /* Find the base binfo within the overriding function's
2154 return type. We will always find a thunk_binfo, except
2155 when the covariancy is invalid (which we will have
2156 already diagnosed). */
2159 thunk_binfo;
2165 /* See if virtual inheritance is involved. */
2167 virtual_offset;
2174 {
2178 {
2179 /* We convert via virtual base. Adjust the fixed
2180 offset to be from there. */
2181 offset =
2185 }
2187 /* There was an existing fixed offset, this must be
2188 from the base just converted to, and the base the
2189 FN was thunking to. */
2191 else
2193 }
2194 }
2197 /* Replace the overriding function with a covariant thunk. We
2198 will emit the overriding function in its own slot as
2199 well. */
2202 }
2203 else
2207 /* If we need a covariant thunk, then we may need to adjust first_defn.
2208 The ABI specifies that the thunks emitted with a function are
2209 determined by which bases the function overrides, so we need to be
2210 sure that we're using a thunk for some overridden base; even if we
2211 know that the necessary this adjustment is zero, there may not be an
2212 appropriate zero-this-adjusment thunk for us to use since thunks for
2213 overriding virtual bases always use the vcall offset.
2215 Furthermore, just choosing any base that overrides this function isn't
2216 quite right, as this slot won't be used for calls through a type that
2217 puts a covariant thunk here. Calling the function through such a type
2218 will use a different slot, and that slot is the one that determines
2219 the thunk emitted for that base.
2221 So, keep looking until we find the base that we're really overriding
2222 in this slot: the nearest primary base that doesn't use a covariant
2223 thunk in this slot. */
2225 {
2227 /* We already know that the overrider needs a covariant thunk. */
2230 {
2237 }
2239 }
2241 /* Assume that we will produce a thunk that convert all the way to
2242 the final overrider, and not to an intermediate virtual base. */
2245 /* See if we can convert to an intermediate virtual base first, and then
2246 use the vcall offset located there to finish the conversion. */
2248 {
2249 /* If we find the final overrider, then we can stop
2250 walking. */
2255 /* If we find a virtual base, and we haven't yet found the
2256 overrider, then there is a virtual base between the
2257 declaring base (first_defn) and the final overrider. */
2259 {
2262 }
2263 }
2265 /* Compute the constant adjustment to the `this' pointer. The
2266 `this' pointer, when this function is called, will point at BINFO
2267 (or one of its primary bases, which are at the same offset). */
2269 /* The `this' pointer needs to be adjusted from the declaration to
2270 the nearest virtual base. */
2275 /* If the nearest definition is in a lost primary, we don't need an
2276 entry in our vtable. Except possibly in a constructor vtable,
2277 if we happen to get our primary back. In that case, the offset
2278 will be zero, as it will be a primary base. */
2280 else
2281 /* The `this' pointer needs to be adjusted from pointing to
2282 BINFO to pointing at the base where the final overrider
2283 appears. */
2294 else
2298 }
2300 /* Called from modify_all_vtables via dfs_walk. */
2302 static tree
2304 {
2306 tree virtuals;
2307 tree old_virtuals;
2311 /* A base without a vtable needs no modification, and its bases
2312 are uninteresting. */
2317 /* Don't do the primary vtable, if it's new. */
2321 /* There's no need to modify the vtable for a non-virtual primary
2322 base; we're not going to use that vtable anyhow. We do still
2323 need to do this for virtual primary bases, as they could become
2324 non-primary in a construction vtable. */
2329 /* Now, go through each of the virtual functions in the virtual
2330 function table for BINFO. Find the final overrider, and update
2331 the BINFO_VIRTUALS list appropriately. */
2334 virtuals;
2338 binfo,
2343 }
2345 /* Update all of the primary and secondary vtables for T. Create new
2346 vtables as required, and initialize their RTTI information. Each
2347 of the functions in VIRTUALS is declared in T and may override a
2348 virtual function from a base class; find and modify the appropriate
2349 entries to point to the overriding functions. Returns a list, in
2350 declaration order, of the virtual functions that are declared in T,
2351 but do not appear in the primary base class vtable, and which
2352 should therefore be appended to the end of the vtable for T. */
2354 static tree
2356 {
2360 /* Update all of the vtables. */
2363 /* Add virtual functions not already in our primary vtable. These
2364 will be both those introduced by this class, and those overridden
2365 from secondary bases. It does not include virtuals merely
2366 inherited from secondary bases. */
2368 {
2373 {
2374 /* We don't need to adjust the `this' pointer when
2375 calling this function. */
2379 /* This is a function not already in our vtable. Keep it. */
2381 }
2382 else
2383 /* We've already got an entry for this function. Skip it. */
2385 }
2388 }
2390 /* Get the base virtual function declarations in T that have the
2391 indicated NAME. */
2393 static tree
2395 {
2396 tree methods;
2401 /* Find virtual functions in T with the indicated NAME. */
2405 methods;
2407 {
2413 }
2419 {
2422 base_fndecls);
2423 }
2426 }
2428 /* If this declaration supersedes the declaration of
2429 a method declared virtual in the base class, then
2430 mark this field as being virtual as well. */
2432 void
2434 {
2437 /* In [temp.mem] we have:
2439 A specialization of a member function template does not
2440 override a virtual function from a base class. */
2447 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2448 the error_mark_node so that we know it is an overriding
2449 function. */
2450 {
2453 }
2456 {
2462 }
2467 }
2469 /* Warn about hidden virtual functions that are not overridden in t.
2470 We know that constructors and destructors don't apply. */
2472 static void
2474 {
2476 tree fns;
2479 /* We go through each separately named virtual function. */
2483 {
2484 tree fn;
2485 tree name;
2486 tree fndecl;
2487 tree base_fndecls;
2488 tree base_binfo;
2489 tree binfo;
2492 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2493 have the same name. Figure out what name that is. */
2495 /* There are no possibly hidden functions yet. */
2497 /* Iterate through all of the base classes looking for possibly
2498 hidden functions. */
2501 {
2504 base_fndecls);
2505 }
2507 /* If there are no functions to hide, continue. */
2511 /* Remove any overridden functions. */
2513 {
2516 {
2520 /* If the method from the base class has the same
2521 signature as the method from the derived class, it
2522 has been overridden. */
2525 else
2527 }
2528 }
2530 /* Now give a warning for all base functions without overriders,
2531 as they are hidden. */
2533 {
2534 /* Here we know it is a hider, and no overrider exists. */
2538 }
2539 }
2540 }
2542 /* Check for things that are invalid. There are probably plenty of other
2543 things we should check for also. */
2545 static void
2547 {
2548 tree field;
2551 {
2559 {
2563 {
2564 /* We're generally only interested in entities the user
2565 declared, but we also find nested classes by noticing
2566 the TYPE_DECL that we create implicitly. You're
2567 allowed to put one anonymous union inside another,
2568 though, so we explicitly tolerate that. We use
2569 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2570 we also allow unnamed types used for defining fields. */
2577 {
2581 else
2585 }
2588 {
2591 else
2593 }
2595 {
2598 else
2600 }
2604 }
2605 }
2606 }
2607 }
2609 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2610 will be used later during class template instantiation.
2611 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2612 a non-static member data (FIELD_DECL), a member function
2613 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2614 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2615 When FRIEND_P is nonzero, T is either a friend class
2616 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2617 (FUNCTION_DECL, TEMPLATE_DECL). */
2619 void
2621 {
2622 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2627 }
2629 /* This function is called from declare_virt_assop_and_dtor via
2630 dfs_walk_all.
2632 DATA is a type that direcly or indirectly inherits the base
2633 represented by BINFO. If BINFO contains a virtual assignment [copy
2634 assignment or move assigment] operator or a virtual constructor,
2635 declare that function in DATA if it hasn't been already declared. */
2637 static tree
2639 {
2647 /* A base without a vtable needs no modification, and its bases
2648 are uninteresting. */
2652 /* If this is a primary base, then we have already looked at the
2653 virtual functions of its vtable. */
2657 {
2661 {
2666 }
2670 }
2673 }
2675 /* If the class type T has a direct or indirect base that contains a
2676 virtual assignment operator or a virtual destructor, declare that
2677 function in T if it hasn't been already declared. */
2679 static void
2681 {
2689 dfs_declare_virt_assop_and_dtor,
2691 }
2693 /* Create default constructors, assignment operators, and so forth for
2694 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2695 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2696 the class cannot have a default constructor, copy constructor
2697 taking a const reference argument, or an assignment operator taking
2698 a const reference, respectively. */
2700 static void
2704 {
2705 /* Destructor. */
2707 {
2708 /* In general, we create destructors lazily. */
2713 /* But if this is a Java class, any non-trivial destructor is
2714 invalid, even if compiler-generated. Therefore, if the
2715 destructor is non-trivial we create it now. */
2717 }
2719 /* [class.ctor]
2721 If there is no user-declared constructor for a class, a default
2722 constructor is implicitly declared. */
2724 {
2730 }
2732 /* [class.ctor]
2734 If a class definition does not explicitly declare a copy
2735 constructor, one is declared implicitly. */
2738 {
2744 }
2746 /* If there is no assignment operator, one will be created if and
2747 when it is needed. For now, just record whether or not the type
2748 of the parameter to the assignment operator will be a const or
2749 non-const reference. */
2752 {
2758 }
2760 /* We can't be lazy about declaring functions that might override
2761 a virtual function from a base class. */
2763 }
2765 /* Subroutine of finish_struct_1. Recursively count the number of fields
2766 in TYPE, including anonymous union members. */
2768 static int
2770 {
2771 tree x;
2774 {
2777 else
2779 }
2781 }
2783 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2784 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2786 static int
2788 {
2789 tree x;
2791 {
2794 else
2796 }
2798 }
2800 /* FIELD is a bit-field. We are finishing the processing for its
2801 enclosing type. Issue any appropriate messages and set appropriate
2802 flags. Returns false if an error has been diagnosed. */
2804 static bool
2806 {
2808 tree w;
2810 /* Extract the declared width of the bitfield, which has been
2811 temporarily stashed in DECL_INITIAL. */
2814 /* Remove the bit-field width indicator so that the rest of the
2815 compiler does not treat that value as an initializer. */
2818 /* Detect invalid bit-field type. */
2820 {
2823 }
2824 else
2825 {
2827 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2830 /* detect invalid field size. */
2836 {
2839 }
2841 {
2844 }
2846 {
2849 }
2858 }
2861 {
2865 }
2866 else
2867 {
2868 /* Non-bit-fields are aligned for their type. */
2872 }
2873 }
2875 /* FIELD is a non bit-field. We are finishing the processing for its
2876 enclosing type T. Issue any appropriate messages and set appropriate
2877 flags. */
2879 static void
2881 tree t,
2885 {
2888 /* In C++98 an anonymous union cannot contain any fields which would change
2889 the settings of CANT_HAVE_CONST_CTOR and friends. */
2891 ;
2892 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
2893 structs. So, we recurse through their fields here. */
2895 {
2896 tree fields;
2902 }
2903 /* Check members with class type for constructors, destructors,
2904 etc. */
2906 {
2907 /* Never let anything with uninheritable virtuals
2908 make it through without complaint. */
2912 {
2917 field);
2922 field);
2924 {
2928 }
2929 }
2930 else
2931 {
2944 }
2953 }
2955 {
2956 /* `build_class_init_list' does not recognize
2957 non-FIELD_DECLs. */
2961 }
2962 }
2964 /* Check the data members (both static and non-static), class-scoped
2965 typedefs, etc., appearing in the declaration of T. Issue
2966 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2967 declaration order) of access declarations; each TREE_VALUE in this
2968 list is a USING_DECL.
2970 In addition, set the following flags:
2972 EMPTY_P
2973 The class is empty, i.e., contains no non-static data members.
2975 CANT_HAVE_CONST_CTOR_P
2976 This class cannot have an implicitly generated copy constructor
2977 taking a const reference.
2979 CANT_HAVE_CONST_ASN_REF
2980 This class cannot have an implicitly generated assignment
2981 operator taking a const reference.
2983 All of these flags should be initialized before calling this
2984 function.
2986 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2987 fields can be added by adding to this chain. */
2989 static void
2993 {
3001 /* Assume there are no access declarations. */
3003 /* Assume this class has no pointer members. */
3005 /* Assume none of the members of this class have default
3006 initializations. */
3010 {
3018 {
3019 /* Prune the access declaration from the list of fields. */
3022 /* Save the access declarations for our caller. */
3025 /* Since we've reset *FIELD there's no reason to skip to the
3026 next field. */
3029 }
3035 /* If we've gotten this far, it's a data member, possibly static,
3036 or an enumerator. */
3039 /* When this goes into scope, it will be a non-local reference. */
3043 {
3044 /* [class.union]
3046 If a union contains a static data member, or a member of
3047 reference type, the program is ill-formed. */
3049 {
3052 }
3054 {
3059 }
3060 }
3062 /* Perform error checking that did not get done in
3063 grokdeclarator. */
3065 {
3069 }
3071 {
3075 }
3083 /* Now it can only be a FIELD_DECL. */
3088 /* If at least one non-static data member is non-literal, the whole
3089 class becomes non-literal. */
3093 /* A standard-layout class is a class that:
3094 ...
3095 has the same access control (Clause 11) for all non-static data members,
3096 ... */
3103 /* If this is of reference type, check if it needs an init. */
3105 {
3111 /* ARM $12.6.2: [A member initializer list] (or, for an
3112 aggregate, initialization by a brace-enclosed list) is the
3113 only way to initialize nonstatic const and reference
3114 members. */
3117 }
3122 {
3124 {
3125 warning
3128 x);
3130 }
3134 }
3137 /* We don't treat zero-width bitfields as making a class
3138 non-empty. */
3139 ;
3140 else
3141 {
3142 /* The class is non-empty. */
3144 /* The class is not even nearly empty. */
3146 /* If one of the data members contains an empty class,
3147 so does T. */
3151 }
3153 /* This is used by -Weffc++ (see below). Warn only for pointers
3154 to members which might hold dynamic memory. So do not warn
3155 for pointers to functions or pointers to members. */
3162 {
3167 }
3173 /* DR 148 now allows pointers to members (which are POD themselves),
3174 to be allowed in POD structs. */
3183 /* We set DECL_C_BIT_FIELD in grokbitfield.
3184 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3187 cant_have_const_ctor_p,
3188 no_const_asn_ref_p,
3191 /* If any field is const, the structure type is pseudo-const. */
3193 {
3198 /* ARM $12.6.2: [A member initializer list] (or, for an
3199 aggregate, initialization by a brace-enclosed list) is the
3200 only way to initialize nonstatic const and reference
3201 members. */
3204 }
3205 /* A field that is pseudo-const makes the structure likewise. */
3207 {
3212 }
3214 /* Core issue 80: A nonstatic data member is required to have a
3215 different name from the class iff the class has a
3216 user-declared constructor. */
3220 }
3222 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3223 it should also define a copy constructor and an assignment operator to
3224 implement the correct copy semantic (deep vs shallow, etc.). As it is
3225 not feasible to check whether the constructors do allocate dynamic memory
3226 and store it within members, we approximate the warning like this:
3228 -- Warn only if there are members which are pointers
3229 -- Warn only if there is a non-trivial constructor (otherwise,
3230 there cannot be memory allocated).
3231 -- Warn only if there is a non-trivial destructor. We assume that the
3232 user at least implemented the cleanup correctly, and a destructor
3233 is needed to free dynamic memory.
3235 This seems enough for practical purposes. */
3237 && has_pointers
3241 {
3245 {
3250 }
3254 }
3256 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3260 /* Check anonymous struct/anonymous union fields. */
3263 /* We've built up the list of access declarations in reverse order.
3264 Fix that now. */
3266 }
3268 /* If TYPE is an empty class type, records its OFFSET in the table of
3269 OFFSETS. */
3271 static int
3273 {
3274 splay_tree_node n;
3279 /* Record the location of this empty object in OFFSETS. */
3287 type,
3291 }
3293 /* Returns nonzero if TYPE is an empty class type and there is
3294 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3296 static int
3298 {
3299 splay_tree_node n;
3300 tree t;
3305 /* Record the location of this empty object in OFFSETS. */
3315 }
3317 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3318 F for every subobject, passing it the type, offset, and table of
3319 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3320 be traversed.
3322 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3323 than MAX_OFFSET will not be walked.
3325 If F returns a nonzero value, the traversal ceases, and that value
3326 is returned. Otherwise, returns zero. */
3328 static int
3330 subobject_offset_fn f,
3331 tree offset,
3332 splay_tree offsets,
3333 tree max_offset,
3335 {
3339 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3340 stop. */
3348 {
3352 }
3355 {
3356 tree field;
3357 tree binfo;
3360 /* Avoid recursing into objects that are not interesting. */
3364 /* Record the location of TYPE. */
3369 /* Iterate through the direct base classes of TYPE. */
3373 {
3374 tree binfo_offset;
3387 offset,
3389 else
3390 {
3391 tree orig_binfo;
3392 /* We cannot rely on BINFO_OFFSET being set for the base
3393 class yet, but the offsets for direct non-virtual
3394 bases can be calculated by going back to the TYPE. */
3397 offset,
3399 }
3402 f,
3403 binfo_offset,
3404 offsets,
3405 max_offset,
3410 }
3413 {
3417 /* Iterate through the virtual base classes of TYPE. In G++
3418 3.2, we included virtual bases in the direct base class
3419 loop above, which results in incorrect results; the
3420 correct offsets for virtual bases are only known when
3421 working with the most derived type. */
3425 {
3427 f,
3429 offset,
3431 offsets,
3432 max_offset,
3436 }
3437 else
3438 {
3439 /* We still have to walk the primary base, if it is
3440 virtual. (If it is non-virtual, then it was walked
3441 above.) */
3447 {
3448 r = (walk_subobject_offsets
3453 }
3454 }
3455 }
3457 /* Iterate through the fields of TYPE. */
3460 {
3461 tree field_offset;
3465 else
3466 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3470 f,
3472 offset,
3473 field_offset),
3474 offsets,
3475 max_offset,
3479 }
3480 }
3482 {
3485 tree index;
3487 /* Avoid recursing into objects that are not interesting. */
3492 /* Step through each of the elements in the array. */
3494 /* G++ 3.2 had an off-by-one error here. */
3499 {
3501 f,
3502 offset,
3503 offsets,
3504 max_offset,
3510 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3511 there's no point in iterating through the remaining
3512 elements of the array. */
3515 }
3516 }
3519 }
3521 /* Record all of the empty subobjects of TYPE (either a type or a
3522 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3523 is being placed at OFFSET; otherwise, it is a base class that is
3524 being placed at OFFSET. */
3526 static void
3528 tree offset,
3529 splay_tree offsets,
3531 {
3532 tree max_offset;
3533 /* If recording subobjects for a non-static data member or a
3534 non-empty base class , we do not need to record offsets beyond
3535 the size of the biggest empty class. Additional data members
3536 will go at the end of the class. Additional base classes will go
3537 either at offset zero (if empty, in which case they cannot
3538 overlap with offsets past the size of the biggest empty class) or
3539 at the end of the class.
3541 However, if we are placing an empty base class, then we must record
3542 all offsets, as either the empty class is at offset zero (where
3543 other empty classes might later be placed) or at the end of the
3544 class (where other objects might then be placed, so other empty
3545 subobjects might later overlap). */
3549 else
3553 }
3555 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3556 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3557 virtual bases of TYPE are examined. */
3559 static int
3561 tree offset,
3562 splay_tree offsets,
3564 {
3565 splay_tree_node max_node;
3567 /* Get the node in OFFSETS that indicates the maximum offset where
3568 an empty subobject is located. */
3570 /* If there aren't any empty subobjects, then there's no point in
3571 performing this check. */
3577 vbases_p);
3578 }
3580 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3581 non-static data member of the type indicated by RLI. BINFO is the
3582 binfo corresponding to the base subobject, OFFSETS maps offsets to
3583 types already located at those offsets. This function determines
3584 the position of the DECL. */
3586 static void
3588 tree decl,
3589 tree binfo,
3590 splay_tree offsets)
3591 {
3594 tree type;
3597 {
3598 /* For the purposes of determining layout conflicts, we want to
3599 use the class type of BINFO; TREE_TYPE (DECL) will be the
3600 CLASSTYPE_AS_BASE version, which does not contain entries for
3601 zero-sized bases. */
3604 }
3605 else
3606 {
3609 }
3611 /* Try to place the field. It may take more than one try if we have
3612 a hard time placing the field without putting two objects of the
3613 same type at the same address. */
3615 {
3618 /* Place this field. */
3622 /* We have to check to see whether or not there is already
3623 something of the same type at the offset we're about to use.
3624 For example, consider:
3626 struct S {};
3627 struct T : public S { int i; };
3628 struct U : public S, public T {};
3630 Here, we put S at offset zero in U. Then, we can't put T at
3631 offset zero -- its S component would be at the same address
3632 as the S we already allocated. So, we have to skip ahead.
3633 Since all data members, including those whose type is an
3634 empty class, have nonzero size, any overlap can happen only
3635 with a direct or indirect base-class -- it can't happen with
3636 a data member. */
3637 /* In a union, overlap is permitted; all members are placed at
3638 offset zero. */
3641 /* G++ 3.2 did not check for overlaps when placing a non-empty
3642 virtual base. */
3647 {
3648 /* Strip off the size allocated to this field. That puts us
3649 at the first place we could have put the field with
3650 proper alignment. */
3653 /* Bump up by the alignment required for the type. */
3654 rli->bitpos
3660 }
3661 else
3662 /* There was no conflict. We're done laying out this field. */
3664 }
3666 /* Now that we know where it will be placed, update its
3667 BINFO_OFFSET. */
3669 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3670 this point because their BINFO_OFFSET is copied from another
3671 hierarchy. Therefore, we may not need to add the entire
3672 OFFSET. */
3678 }
3680 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3682 static int
3684 tree offset,
3685 splay_tree offsets ATTRIBUTE_UNUSED)
3686 {
3688 }
3690 /* Layout the empty base BINFO. EOC indicates the byte currently just
3691 past the end of the class, and should be correctly aligned for a
3692 class of the type indicated by BINFO; OFFSETS gives the offsets of
3693 the empty bases allocated so far. T is the most derived
3694 type. Return nonzero iff we added it at the end. */
3696 static bool
3699 {
3700 tree alignment;
3704 /* This routine should only be used for empty classes. */
3709 {
3711 propagate_binfo_offsets
3714 else
3716 "offset of empty base %qT may not be ABI-compliant and may"
3719 }
3721 /* This is an empty base class. We first try to put it at offset
3722 zero. */
3725 offsets,
3727 {
3728 /* That didn't work. Now, we move forward from the next
3729 available spot in the class. */
3733 {
3736 offsets,
3738 /* We finally found a spot where there's no overlap. */
3741 /* There's overlap here, too. Bump along to the next spot. */
3743 }
3744 }
3747 {
3752 }
3755 }
3757 /* Layout the base given by BINFO in the class indicated by RLI.
3758 *BASE_ALIGN is a running maximum of the alignments of
3759 any base class. OFFSETS gives the location of empty base
3760 subobjects. T is the most derived type. Return nonzero if the new
3761 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3762 *NEXT_FIELD, unless BINFO is for an empty base class.
3764 Returns the location at which the next field should be inserted. */
3769 {
3774 /* This error is now reported in xref_tag, thus giving better
3775 location information. */
3778 /* Place the base class. */
3780 {
3781 tree decl;
3783 /* The containing class is non-empty because it has a non-empty
3784 base class. */
3787 /* Create the FIELD_DECL. */
3794 {
3802 /* Try to place the field. It may take more than one try if we
3803 have a hard time placing the field without putting two
3804 objects of the same type at the same address. */
3806 /* Add the new FIELD_DECL to the list of fields for T. */
3810 }
3811 }
3812 else
3813 {
3814 tree eoc;
3817 /* On some platforms (ARM), even empty classes will not be
3818 byte-aligned. */
3823 /* A nearly-empty class "has no proper base class that is empty,
3824 not morally virtual, and at an offset other than zero." */
3826 {
3829 /* The check above (used in G++ 3.2) is insufficient because
3830 an empty class placed at offset zero might itself have an
3831 empty base at a nonzero offset. */
3833 empty_base_at_nonzero_offset_p,
3834 size_zero_node,
3838 {
3841 else
3843 "class %qT will be considered nearly empty in a "
3845 }
3846 }
3848 /* We do not create a FIELD_DECL for empty base classes because
3849 it might overlap some other field. We want to be able to
3850 create CONSTRUCTORs for the class by iterating over the
3851 FIELD_DECLs, and the back end does not handle overlapping
3852 FIELD_DECLs. */
3854 /* An empty virtual base causes a class to be non-empty
3855 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3856 here because that was already done when the virtual table
3857 pointer was created. */
3858 }
3860 /* Record the offsets of BINFO and its base subobjects. */
3863 offsets,
3867 }
3869 /* Layout all of the non-virtual base classes. Record empty
3870 subobjects in OFFSETS. T is the most derived type. Return nonzero
3871 if the type cannot be nearly empty. The fields created
3872 corresponding to the base classes will be inserted at
3873 *NEXT_FIELD. */
3875 static void
3878 {
3879 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3880 subobjects. */
3885 /* The primary base class is always allocated first. */
3890 /* Now allocate the rest of the bases. */
3892 {
3893 tree base_binfo;
3897 /* The primary base was already allocated above, so we don't
3898 need to allocate it again here. */
3902 /* Virtual bases are added at the end (a primary virtual base
3903 will have already been added). */
3909 }
3910 }
3912 /* Go through the TYPE_METHODS of T issuing any appropriate
3913 diagnostics, figuring out which methods override which other
3914 methods, and so forth. */
3916 static void
3918 {
3919 tree x;
3922 {
3926 /* The name of the field is the original field name
3927 Save this in auxiliary field for later overloading. */
3929 {
3933 }
3934 /* All user-provided destructors are non-trivial.
3935 Constructors and assignment ops are handled in
3936 grok_special_member_properties. */
3939 }
3940 }
3942 /* FN is a constructor or destructor. Clone the declaration to create
3943 a specialized in-charge or not-in-charge version, as indicated by
3944 NAME. */
3946 static tree
3948 {
3949 tree parms;
3950 tree clone;
3952 /* Copy the function. */
3954 /* Reset the function name. */
3957 /* Remember where this function came from. */
3959 /* Make it easy to find the CLONE given the FN. */
3963 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
3965 {
3972 }
3975 /* There's no pending inline data for this function. */
3979 /* The base-class destructor is not virtual. */
3981 {
3985 }
3987 /* If there was an in-charge parameter, drop it from the function
3988 type. */
3990 {
3991 tree basetype;
3992 tree parmtypes;
3993 tree exceptions;
3998 /* Skip the `this' parameter. */
4000 /* Skip the in-charge parameter. */
4002 /* And the VTT parm, in a complete [cd]tor. */
4006 /* If this is subobject constructor or destructor, add the vtt
4007 parameter. */
4011 parmtypes);
4014 exceptions);
4018 }
4020 /* Copy the function parameters. */
4022 /* Remove the in-charge parameter. */
4024 {
4028 }
4029 /* And the VTT parm, in a complete [cd]tor. */
4031 {
4034 else
4035 {
4039 }
4040 }
4043 {
4046 }
4048 /* Create the RTL for this function. */
4056 }
4058 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4059 not invoke this function directly.
4061 For a non-thunk function, returns the address of the slot for storing
4062 the function it is a clone of. Otherwise returns NULL_TREE.
4064 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4065 cloned_function is unset. This is to support the separate
4066 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4067 on a template makes sense, but not the former. */
4069 tree *
4071 {
4079 {
4080 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4083 else
4084 #endif
4086 }
4091 else
4093 }
4095 /* Produce declarations for all appropriate clones of FN. If
4096 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4097 CLASTYPE_METHOD_VEC as well. */
4099 void
4101 {
4102 tree clone;
4104 /* Avoid inappropriate cloning. */
4110 {
4111 /* For each constructor, we need two variants: an in-charge version
4112 and a not-in-charge version. */
4119 }
4120 else
4121 {
4124 /* For each destructor, we need three variants: an in-charge
4125 version, a not-in-charge version, and an in-charge deleting
4126 version. We clone the deleting version first because that
4127 means it will go second on the TYPE_METHODS list -- and that
4128 corresponds to the correct layout order in the virtual
4129 function table.
4131 For a non-virtual destructor, we do not build a deleting
4132 destructor. */
4134 {
4138 }
4145 }
4147 /* Note that this is an abstract function that is never emitted. */
4149 }
4151 /* DECL is an in charge constructor, which is being defined. This will
4152 have had an in class declaration, from whence clones were
4153 declared. An out-of-class definition can specify additional default
4154 arguments. As it is the clones that are involved in overload
4155 resolution, we must propagate the information from the DECL to its
4156 clones. */
4158 void
4160 {
4161 tree clone;
4165 {
4172 /* Skip the 'this' parameter. */
4188 {
4193 {
4194 /* A default parameter has been added. Adjust the
4195 clone's parameters. */
4199 tree type;
4204 {
4207 clone_parms);
4209 }
4212 clone_parms);
4221 }
4222 }
4224 }
4225 }
4227 /* For each of the constructors and destructors in T, create an
4228 in-charge and not-in-charge variant. */
4230 static void
4232 {
4233 tree fns;
4235 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4236 out now. */
4244 }
4246 /* Returns true iff class T has a user-defined constructor other than
4247 the default constructor. */
4249 bool
4251 {
4252 tree fns;
4258 {
4265 }
4268 }
4270 /* Returns the defaulted constructor if T has one. Otherwise, returns
4271 NULL_TREE. */
4273 tree
4275 {
4282 {
4286 {
4292 }
4293 }
4296 }
4298 /* Returns true iff FN is a user-provided function, i.e. user-declared
4299 and not defaulted at its first declaration; or explicit, private,
4300 protected, or non-const. */
4302 bool
4304 {
4307 else
4310 }
4312 /* Returns true iff class T has a user-provided constructor. */
4314 bool
4316 {
4317 tree fns;
4325 /* This can happen in error cases; avoid crashing. */
4334 }
4336 /* Returns true iff class T has a user-provided default constructor. */
4338 bool
4340 {
4341 tree fns;
4347 {
4353 }
4356 }
4358 /* Returns true iff for class T, a synthesized default constructor
4359 would be constexpr. */
4361 bool
4363 {
4364 /* A defaulted default constructor is constexpr
4365 if there is nothing to initialize. */
4366 /* FIXME adjust for non-static data member initializers. */
4368 }
4370 /* Returns true iff class T has a constexpr default constructor. */
4372 bool
4374 {
4375 tree fns;
4378 {
4379 /* The caller should have stripped an enclosing array. */
4382 }
4387 }
4389 /* Returns true iff class TYPE has a virtual destructor. */
4391 bool
4393 {
4394 tree dtor;
4402 }
4404 /* Returns true iff class T has a move constructor. */
4406 bool
4408 {
4409 tree fns;
4412 {
4415 }
4425 }
4427 /* Returns true iff class T has a move assignment operator. */
4429 bool
4431 {
4432 tree fns;
4435 {
4438 }
4446 }
4448 /* Nonzero if we need to build up a constructor call when initializing an
4449 object of this class, either because it has a user-provided constructor
4450 or because it doesn't have a default constructor (so we need to give an
4451 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
4452 what you care about is whether or not an object can be produced by a
4453 constructor (e.g. so we don't set TREE_READONLY on const variables of
4454 such type); use this function when what you care about is whether or not
4455 to try to call a constructor to create an object. The latter case is
4456 the former plus some cases of constructors that cannot be called. */
4458 bool
4460 {
4461 tree inner;
4467 }
4469 /* Remove all zero-width bit-fields from T. */
4471 static void
4473 {
4478 {
4481 /* We should not be confused by the fact that grokbitfield
4482 temporarily sets the width of the bit field into
4483 DECL_INITIAL (*fieldsp).
4484 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
4485 to that width. */
4488 else
4490 }
4491 }
4493 /* Returns TRUE iff we need a cookie when dynamically allocating an
4494 array whose elements have the indicated class TYPE. */
4496 static bool
4498 {
4499 tree fns;
4504 /* If there's a non-trivial destructor, we need a cookie. In order
4505 to iterate through the array calling the destructor for each
4506 element, we'll have to know how many elements there are. */
4510 /* If the usual deallocation function is a two-argument whose second
4511 argument is of type `size_t', then we have to pass the size of
4512 the array to the deallocation function, so we will need to store
4513 a cookie. */
4517 /* If there are no `operator []' members, or the lookup is
4518 ambiguous, then we don't need a cookie. */
4521 /* Loop through all of the functions. */
4523 {
4524 tree fn;
4525 tree second_parm;
4527 /* Select the current function. */
4529 /* See if this function is a one-argument delete function. If
4530 it is, then it will be the usual deallocation function. */
4534 /* Do not consider this function if its second argument is an
4535 ellipsis. */
4538 /* Otherwise, if we have a two-argument function and the second
4539 argument is `size_t', it will be the usual deallocation
4540 function -- unless there is one-argument function, too. */
4544 }
4547 }
4549 /* Finish computing the `literal type' property of class type T.
4551 At this point, we have already processed base classes and
4552 non-static data members. We need to check whether the copy
4553 constructor is trivial, the destructor is trivial, and there
4554 is a trivial default constructor or at least one constexpr
4555 constructor other than the copy constructor. */
4557 static void
4559 {
4560 tree fn;
4576 {
4579 {
4583 }
4584 }
4585 }
4587 /* T is a non-literal type used in a context which requires a constant
4588 expression. Explain why it isn't literal. */
4590 void
4592 {
4602 /* Already explained. */
4612 "default constructor, and has no constexpr constructor that "
4614 else
4615 {
4619 {
4622 {
4627 }
4628 }
4630 {
4631 tree ftype;
4636 {
4641 }
4642 }
4643 }
4644 }
4646 /* Check the validity of the bases and members declared in T. Add any
4647 implicitly-generated functions (like copy-constructors and
4648 assignment operators). Compute various flag bits (like
4649 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
4650 level: i.e., independently of the ABI in use. */
4652 static void
4654 {
4655 /* Nonzero if the implicitly generated copy constructor should take
4656 a non-const reference argument. */
4658 /* Nonzero if the implicitly generated assignment operator
4659 should take a non-const reference argument. */
4661 tree access_decls;
4664 tree fn;
4666 /* By default, we use const reference arguments and generate default
4667 constructors. */
4671 /* Check all the base-classes. */
4675 /* Check all the method declarations. */
4678 /* Save the initial values of these flags which only indicate whether
4679 or not the class has user-provided functions. As we analyze the
4680 bases and members we can set these flags for other reasons. */
4684 /* Check all the data member declarations. We cannot call
4685 check_field_decls until we have called check_bases check_methods,
4686 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4687 being set appropriately. */
4692 /* A nearly-empty class has to be vptr-containing; a nearly empty
4693 class contains just a vptr. */
4697 /* Do some bookkeeping that will guide the generation of implicitly
4698 declared member functions. */
4701 /* We need to call a constructor for this class if it has a
4702 user-provided constructor, or if the default constructor is going
4703 to initialize the vptr. (This is not an if-and-only-if;
4704 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
4705 themselves need constructing.) */
4708 /* [dcl.init.aggr]
4710 An aggregate is an array or a class with no user-provided
4711 constructors ... and no virtual functions.
4713 Again, other conditions for being an aggregate are checked
4714 elsewhere. */
4717 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
4718 retain the old definition internally for ABI reasons. */
4727 /* If the class has no user-declared constructor, but does have
4728 non-static const or reference data members that can never be
4729 initialized, issue a warning. */
4731 /* Classes with user-declared constructors are presumed to
4732 initialize these members. */
4734 /* Aggregates can be initialized with brace-enclosed
4735 initializers. */
4737 {
4738 tree field;
4741 {
4742 tree type;
4756 }
4757 }
4759 /* Synthesize any needed methods. */
4761 cant_have_const_ctor,
4762 no_const_asn_ref);
4764 /* Check defaulted declarations here so we have cant_have_const_ctor
4765 and don't need to worry about clones. */
4768 {
4771 {
4772 bool imp_const_p
4778 /* If the function is defaulted outside the class, we just
4779 give the synthesis error. */
4785 }
4787 }
4790 {
4791 /* "The closure type associated with a lambda-expression has a deleted
4792 default constructor and a deleted copy assignment operator." */
4798 /* "This class type is not an aggregate." */
4800 }
4802 /* Compute the 'literal type' property before we
4803 do anything with non-static member functions. */
4806 /* Create the in-charge and not-in-charge variants of constructors
4807 and destructors. */
4810 /* Process the using-declarations. */
4814 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4817 /* Figure out whether or not we will need a cookie when dynamically
4818 allocating an array of this type. */
4821 }
4823 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4824 accordingly. If a new vfield was created (because T doesn't have a
4825 primary base class), then the newly created field is returned. It
4826 is not added to the TYPE_FIELDS list; it is the caller's
4827 responsibility to do that. Accumulate declared virtual functions
4828 on VIRTUALS_P. */
4830 static tree
4832 {
4833 tree fn;
4835 /* Collect the virtual functions declared in T. */
4839 {
4848 }
4850 /* If we couldn't find an appropriate base class, create a new field
4851 here. Even if there weren't any new virtual functions, we might need a
4852 new virtual function table if we're supposed to include vptrs in
4853 all classes that need them. */
4855 {
4856 /* We build this decl with vtbl_ptr_type_node, which is a
4857 `vtable_entry_type*'. It might seem more precise to use
4858 `vtable_entry_type (*)[N]' where N is the number of virtual
4859 functions. However, that would require the vtable pointer in
4860 base classes to have a different type than the vtable pointer
4861 in derived classes. We could make that happen, but that
4862 still wouldn't solve all the problems. In particular, the
4863 type-based alias analysis code would decide that assignments
4864 to the base class vtable pointer can't alias assignments to
4865 the derived class vtable pointer, since they have different
4866 types. Thus, in a derived class destructor, where the base
4867 class constructor was inlined, we could generate bad code for
4868 setting up the vtable pointer.
4870 Therefore, we use one type for all vtable pointers. We still
4871 use a type-correct type; it's just doesn't indicate the array
4872 bounds. That's better than using `void*' or some such; it's
4873 cleaner, and it let's the alias analysis code know that these
4874 stores cannot alias stores to void*! */
4875 tree field;
4888 /* This class is non-empty. */
4892 }
4895 }
4897 /* Add OFFSET to all base types of BINFO which is a base in the
4898 hierarchy dominated by T.
4900 OFFSET, which is a type offset, is number of bytes. */
4902 static void
4904 {
4906 tree primary_binfo;
4907 tree base_binfo;
4909 /* Update BINFO's offset. */
4914 offset));
4916 /* Find the primary base class. */
4922 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4923 downwards. */
4925 {
4926 /* Don't do the primary base twice. */
4934 }
4935 }
4937 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4938 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4939 empty subobjects of T. */
4941 static void
4943 {
4944 tree vbase;
4953 {
4954 /* In G++ 3.2, we incorrectly rounded the size before laying out
4955 the virtual bases. */
4957 #ifdef STRUCTURE_SIZE_BOUNDARY
4958 /* Packed structures don't need to have minimum size. */
4961 #endif
4965 }
4967 /* Find the last field. The artificial fields created for virtual
4968 bases will go after the last extant field to date. */
4973 /* Go through the virtual bases, allocating space for each virtual
4974 base that is not already a primary base class. These are
4975 allocated in inheritance graph order. */
4977 {
4982 {
4985 /* This virtual base is not a primary base of any class in the
4986 hierarchy, so we have to add space for it. */
4990 /* If the first virtual base might have been placed at a
4991 lower address, had we started from CLASSTYPE_SIZE, rather
4992 than TYPE_SIZE, issue a warning. There can be both false
4993 positives and false negatives from this warning in rare
4994 cases; to deal with all the possibilities would probably
4995 require performing both layout algorithms and comparing
4996 the results which is not particularly tractable. */
4998 && first_vbase
4999 && (tree_int_cst_lt
5004 bitsize_unit_node),
5007 "offset of virtual base %qT is not ABI-compliant and "
5009 basetype);
5012 }
5013 }
5014 }
5016 /* Returns the offset of the byte just past the end of the base class
5017 BINFO. */
5019 static tree
5021 {
5022 tree size;
5027 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5028 allocate some space for it. It cannot have virtual bases, so
5029 TYPE_SIZE_UNIT is fine. */
5031 else
5035 }
5037 /* Returns the offset of the byte just past the end of the base class
5038 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5039 only non-virtual bases are included. */
5041 static tree
5043 {
5046 tree binfo;
5047 tree base_binfo;
5048 tree offset;
5053 {
5063 }
5065 /* G++ 3.2 did not check indirect virtual bases. */
5069 {
5073 }
5076 }
5078 /* Warn about bases of T that are inaccessible because they are
5079 ambiguous. For example:
5081 struct S {};
5082 struct T : public S {};
5083 struct U : public S, public T {};
5085 Here, `(S*) new U' is not allowed because there are two `S'
5086 subobjects of U. */
5088 static void
5090 {
5093 tree basetype;
5094 tree binfo;
5095 tree base_binfo;
5097 /* If there are no repeated bases, nothing can be ambiguous. */
5101 /* Check direct bases. */
5104 {
5110 }
5112 /* Check for ambiguous virtual bases. */
5116 {
5122 }
5123 }
5125 /* Compare two INTEGER_CSTs K1 and K2. */
5127 static int
5129 {
5131 }
5133 /* Increase the size indicated in RLI to account for empty classes
5134 that are "off the end" of the class. */
5136 static void
5138 {
5139 tree eoc;
5140 tree rli_size;
5142 /* It might be the case that we grew the class to allocate a
5143 zero-sized base class. That won't be reflected in RLI, yet,
5144 because we are willing to overlay multiple bases at the same
5145 offset. However, now we need to make sure that RLI is big enough
5146 to reflect the entire class. */
5152 {
5154 /* In version 1 of the ABI, the size of a class that ends with
5155 a bitfield was not rounded up to a whole multiple of a
5156 byte. Because rli_size_unit_so_far returns only the number
5157 of fully allocated bytes, any extra bits were not included
5158 in the size. */
5160 else
5161 /* The size should have been rounded to a whole byte. */
5164 rli->bitpos
5173 }
5174 }
5176 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5177 BINFO_OFFSETs for all of the base-classes. Position the vtable
5178 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5180 static void
5182 {
5183 tree non_static_data_members;
5184 tree field;
5185 tree vptr;
5186 record_layout_info rli;
5187 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5188 types that appear at that offset. */
5189 splay_tree empty_base_offsets;
5190 /* True if the last field layed out was a bit-field. */
5192 /* The location at which the next field should be inserted. */
5194 /* T, as a base class. */
5195 tree base_t;
5197 /* Keep track of the first non-static data member. */
5200 /* Start laying out the record. */
5203 /* Mark all the primary bases in the hierarchy. */
5206 /* Create a pointer to our virtual function table. */
5209 /* The vptr is always the first thing in the class. */
5211 {
5216 }
5217 else
5220 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5225 /* Layout the non-static data members. */
5227 {
5228 tree type;
5229 tree padding;
5231 /* We still pass things that aren't non-static data members to
5232 the back end, in case it wants to do something with them. */
5234 {
5236 /* If the static data member has incomplete type, keep track
5237 of it so that it can be completed later. (The handling
5238 of pending statics in finish_record_layout is
5239 insufficient; consider:
5241 struct S1;
5242 struct S2 { static S1 s1; };
5244 At this point, finish_record_layout will be called, but
5245 S1 is still incomplete.) */
5247 {
5249 /* The visibility of static data members is determined
5250 at their point of declaration, not their point of
5251 definition. */
5253 }
5255 }
5263 /* If this field is a bit-field whose width is greater than its
5264 type, then there are some special rules for allocating
5265 it. */
5268 {
5270 tree integer_type;
5272 /* We must allocate the bits as if suitably aligned for the
5273 longest integer type that fits in this many bits. type
5274 of the field. Then, we are supposed to use the left over
5275 bits as additional padding. */
5284 /* ITK now indicates a type that is too large for the
5285 field. We have to back up by one to find the largest
5286 type that fits. */
5287 do
5288 {
5293 /* Figure out how much additional padding is required. GCC
5294 3.2 always created a padding field, even if it had zero
5295 width. */
5298 {
5300 /* In a union, the padding field must have the full width
5301 of the bit-field; all fields start at offset zero. */
5303 else
5304 {
5307 "ABI-compliant and may change in a future "
5309 t);
5312 }
5313 }
5314 #ifdef PCC_BITFIELD_TYPE_MATTERS
5315 /* An unnamed bitfield does not normally affect the
5316 alignment of the containing class on a target where
5317 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5318 make any exceptions for unnamed bitfields when the
5319 bitfields are longer than their types. Therefore, we
5320 temporarily give the field a name. */
5322 {
5325 }
5326 #endif
5331 empty_base_offsets);
5334 /* Now that layout has been performed, set the size of the
5335 field to the size of its declared type; the rest of the
5336 field is effectively invisible. */
5338 /* We must also reset the DECL_MODE of the field. */
5343 /* Versions of G++ before G++ 3.4 did not reset the
5344 DECL_MODE. */
5346 "the offset of %qD may not be ABI-compliant and may "
5348 }
5349 else
5351 empty_base_offsets);
5353 /* Remember the location of any empty classes in FIELD. */
5357 empty_base_offsets,
5360 /* If a bit-field does not immediately follow another bit-field,
5361 and yet it starts in the middle of a byte, we have failed to
5362 comply with the ABI. */
5365 /* The TREE_NO_WARNING flag gets set by Objective-C when
5366 laying out an Objective-C class. The ObjC ABI differs
5367 from the C++ ABI, and so we do not want a warning
5368 here. */
5370 && !last_field_was_bitfield
5373 bitsize_unit_node)))
5377 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5378 offset of the field. */
5385 "classes to be placed at different locations in a "
5388 /* The middle end uses the type of expressions to determine the
5389 possible range of expression values. In order to optimize
5390 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5391 must be made aware of the width of "i", via its type.
5393 Because C++ does not have integer types of arbitrary width,
5394 we must (for the purposes of the front end) convert from the
5395 type assigned here to the declared type of the bitfield
5396 whenever a bitfield expression is used as an rvalue.
5397 Similarly, when assigning a value to a bitfield, the value
5398 must be converted to the type given the bitfield here. */
5400 {
5405 {
5412 }
5413 }
5415 /* If we needed additional padding after this field, add it
5416 now. */
5418 {
5419 tree padding_field;
5422 FIELD_DECL,
5423 NULL_TREE,
5424 char_type_node);
5431 NULL_TREE,
5432 empty_base_offsets);
5433 }
5436 }
5439 {
5440 /* Make sure that we are on a byte boundary so that the size of
5441 the class without virtual bases will always be a round number
5442 of bytes. */
5445 }
5447 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5448 padding. */
5452 /* Delete all zero-width bit-fields from the list of fields. Now
5453 that the type is laid out they are no longer important. */
5456 /* Create the version of T used for virtual bases. We do not use
5457 make_class_type for this version; this is an artificial type. For
5458 a POD type, we just reuse T. */
5460 {
5463 /* Set the size and alignment for the new type. In G++ 3.2, all
5464 empty classes were considered to have size zero when used as
5465 base classes. */
5467 {
5472 "layout of classes derived from empty class %qT "
5474 t);
5475 }
5476 else
5477 {
5478 tree eoc;
5480 /* If the ABI version is not at least two, and the last
5481 field was a bit-field, RLI may not be on a byte
5482 boundary. In particular, rli_size_unit_so_far might
5483 indicate the last complete byte, while rli_size_so_far
5484 indicates the total number of bits used. Therefore,
5485 rli_size_so_far, rather than rli_size_unit_so_far, is
5486 used to compute TYPE_SIZE_UNIT. */
5494 eoc);
5501 }
5505 /* Copy the fields from T. */
5509 {
5511 FIELD_DECL,
5521 }
5523 /* Record the base version of the type. */
5526 }
5527 else
5530 /* Every empty class contains an empty class. */
5534 /* Set the TYPE_DECL for this type to contain the right
5535 value for DECL_OFFSET, so that we can use it as part
5536 of a COMPONENT_REF for multiple inheritance. */
5539 /* Now fix up any virtual base class types that we left lying
5540 around. We must get these done before we try to lay out the
5541 virtual function table. As a side-effect, this will remove the
5542 base subobject fields. */
5545 /* Make sure that empty classes are reflected in RLI at this
5546 point. */
5549 /* Make sure not to create any structures with zero size. */
5555 /* If this is a non-POD, declaring it packed makes a difference to how it
5556 can be used as a field; don't let finalize_record_size undo it. */
5560 /* Let the back end lay out the type. */
5563 /* Warn about bases that can't be talked about due to ambiguity. */
5566 /* Now that we're done with layout, give the base fields the real types. */
5571 /* Clean up. */
5578 }
5580 /* Determine the "key method" for the class type indicated by TYPE,
5581 and set CLASSTYPE_KEY_METHOD accordingly. */
5583 void
5585 {
5586 tree method;
5589 || processing_template_decl
5594 /* The key method is the first non-pure virtual function that is not
5595 inline at the point of class definition. On some targets the
5596 key function may not be inline; those targets should not call
5597 this function until the end of the translation unit. */
5603 {
5606 }
5609 }
5611 /* Perform processing required when the definition of T (a class type)
5612 is complete. */
5614 void
5616 {
5617 tree x;
5618 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5623 {
5628 }
5630 /* If this type was previously laid out as a forward reference,
5631 make sure we lay it out again. */
5635 /* Make assumptions about the class; we'll reset the flags if
5636 necessary. */
5642 /* Do end-of-class semantic processing: checking the validity of the
5643 bases and members and add implicitly generated methods. */
5646 /* Find the key method. */
5648 {
5649 /* The Itanium C++ ABI permits the key method to be chosen when
5650 the class is defined -- even though the key method so
5651 selected may later turn out to be an inline function. On
5652 some systems (such as ARM Symbian OS) the key method cannot
5653 be determined until the end of the translation unit. On such
5654 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
5655 will cause the class to be added to KEYED_CLASSES. Then, in
5656 finish_file we will determine the key method. */
5660 /* If a polymorphic class has no key method, we may emit the vtable
5661 in every translation unit where the class definition appears. */
5664 }
5666 /* Layout the class itself. */
5669 /* We use the base type for trivial assignments, and hence it
5670 needs a mode. */
5675 /* If necessary, create the primary vtable for this class. */
5677 {
5678 /* We must enter these virtuals into the table. */
5682 /* Here we know enough to change the type of our virtual
5683 function table, but we will wait until later this function. */
5685 }
5688 {
5690 tree fn;
5697 /* Add entries for virtual functions introduced by this class. */
5701 /* Set DECL_VINDEX for all functions declared in this class. */
5703 fn;
5705 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5707 {
5711 /* A thunk. We should never be calling this entry directly
5712 from this vtable -- we'd use the entry for the non
5713 thunk base function. */
5717 }
5718 }
5722 /* Complete the rtl for any static member objects of the type we're
5723 working on. */
5730 /* Done with FIELDS...now decide whether to sort these for
5731 faster lookups later.
5733 We use a small number because most searches fail (succeeding
5734 ultimately as the search bores through the inheritance
5735 hierarchy), and we want this failure to occur quickly. */
5739 {
5745 field_decl_cmp);
5747 }
5749 /* Complain if one of the field types requires lower visibility. */
5752 /* Make the rtl for any new vtables we have created, and unmark
5753 the base types we marked. */
5756 /* Build the VTT for T. */
5759 /* This warning does not make sense for Java classes, since they
5760 cannot have destructors. */
5762 {
5763 tree dtor;
5767 if it were virtual, we would have created it by now. */
5768 !dtor
5777 "%q#T has virtual functions and accessible"
5779 }
5786 /* Class layout, assignment of virtual table slots, etc., is now
5787 complete. Give the back end a chance to tweak the visibility of
5788 the class or perform any other required target modifications. */
5795 /* Finish debugging output for this type. */
5797 }
5799 /* When T was built up, the member declarations were added in reverse
5800 order. Rearrange them to declaration order. */
5802 void
5804 {
5805 tree next;
5806 tree prev;
5807 tree x;
5809 /* The following lists are all in reverse order. Put them in
5810 declaration order now. */
5814 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5815 reverse order, so we can't just use nreverse. */
5820 {
5824 }
5826 {
5830 }
5831 }
5833 tree
5835 {
5838 /* Now that we've got all the field declarations, reverse everything
5839 as necessary. */
5844 /* Nadger the current location so that diagnostics point to the start of
5845 the struct, not the end. */
5849 {
5850 tree x;
5856 /* We need to emit an error message if this type was used as a parameter
5857 and it is an abstract type, even if it is a template. We construct
5858 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5859 account and we call complete_vars with this type, which will check
5860 the PARM_DECLS. Note that while the type is being defined,
5861 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5862 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5869 /* Remember current #pragma pack value. */
5871 }
5872 else
5881 else
5888 }
5889 \f
5890 /* Return the dynamic type of INSTANCE, if known.
5891 Used to determine whether the virtual function table is needed
5892 or not.
5894 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5895 of our knowledge of its type. *NONNULL should be initialized
5896 before this function is called. */
5898 static tree
5900 {
5901 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
5904 {
5908 else
5912 /* This is a call to a constructor, hence it's never zero. */
5914 {
5918 }
5922 /* This is a call to a constructor, hence it's never zero. */
5924 {
5928 }
5937 /* Propagate nonnull. */
5942 CASE_CONVERT:
5948 {
5949 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5950 with a real object -- given &p->f, p can still be null. */
5952 /* ??? Probably should check DECL_WEAK here. */
5955 }
5959 /* If this component is really a base class reference, then the field
5960 itself isn't definitive. */
5969 {
5973 }
5974 /* fall through... */
5979 {
5983 }
5985 {
5989 /* if we're in a ctor or dtor, we know our type. */
5993 {
5997 }
5998 }
6000 {
6001 /* We only need one hash table because it is always left empty. */
6005 htab_hash_pointer,
6006 htab_eq_pointer,
6009 /* Reference variables should be references to objects. */
6013 /* Enter the INSTANCE in a table to prevent recursion; a
6014 variable's initializer may refer to the variable
6015 itself. */
6020 {
6021 tree type;
6030 }
6031 }
6036 }
6037 #undef RECUR
6038 }
6040 /* Return nonzero if the dynamic type of INSTANCE is known, and
6041 equivalent to the static type. We also handle the case where
6042 INSTANCE is really a pointer. Return negative if this is a
6043 ctor/dtor. There the dynamic type is known, but this might not be
6044 the most derived base of the original object, and hence virtual
6045 bases may not be layed out according to this type.
6047 Used to determine whether the virtual function table is needed
6048 or not.
6050 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6051 of our knowledge of its type. *NONNULL should be initialized
6052 before this function is called. */
6054 int
6056 {
6059 tree fixed;
6062 {
6063 /* In a template we only care about the type of the result. */
6067 }
6077 }
6079 \f
6080 void
6082 {
6085 current_class_stack
6093 }
6095 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6097 static void
6099 {
6100 tree type;
6102 /* We are re-entering the same class we just left, so we don't
6103 have to search the whole inheritance matrix to find all the
6104 decls to bind again. Instead, we install the cached
6105 class_shadowed list and walk through it binding names. */
6108 /* Restore IDENTIFIER_TYPE_VALUE. */
6110 type;
6113 }
6115 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6116 appropriate for TYPE.
6118 So that we may avoid calls to lookup_name, we cache the _TYPE
6119 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6121 For multiple inheritance, we perform a two-pass depth-first search
6122 of the type lattice. */
6124 void
6126 {
6127 class_stack_node_t csn;
6131 /* Make sure there is enough room for the new entry on the stack. */
6133 {
6135 current_class_stack
6137 current_class_stack_size);
6138 }
6140 /* Insert a new entry on the class stack. */
6147 current_class_depth++;
6149 /* Now set up the new type. */
6155 /* By default, things in classes are private, while things in
6156 structures or unions are public. */
6158 ? access_private_node
6164 {
6165 /* Forcibly remove any old class remnants. */
6167 }
6173 else
6175 }
6177 /* When we exit a toplevel class scope, we save its binding level so
6178 that we can restore it quickly. Here, we've entered some other
6179 class, so we must invalidate our cache. */
6181 void
6183 {
6185 }
6187 /* Get out of the current class scope. If we were in a class scope
6188 previously, that is the one popped to. */
6190 void
6192 {
6195 current_class_depth--;
6201 }
6203 /* Mark the top of the class stack as hidden. */
6205 void
6207 {
6210 }
6212 /* Mark the top of the class stack as un-hidden. */
6214 void
6216 {
6219 }
6221 /* Returns 1 if the class type currently being defined is either T or
6222 a nested type of T. */
6224 bool
6226 {
6234 /* We start looking from 1 because entry 0 is from global scope,
6235 and has no type. */
6237 {
6238 tree c;
6241 else
6242 {
6246 }
6251 }
6253 }
6255 /* If either current_class_type or one of its enclosing classes are derived
6256 from T, return the appropriate type. Used to determine how we found
6257 something via unqualified lookup. */
6259 tree
6261 {
6264 /* The bases of a dependent type are unknown. */
6275 {
6280 }
6283 }
6285 /* Returns the innermost class type which is not a lambda closure type. */
6287 tree
6289 {
6292 /* We start looking from 1 because entry 0 is from global scope,
6293 and has no type. */
6295 {
6296 tree c;
6299 else
6300 {
6304 }
6309 }
6311 }
6313 /* When entering a class scope, all enclosing class scopes' names with
6314 static meaning (static variables, static functions, types and
6315 enumerators) have to be visible. This recursive function calls
6316 pushclass for all enclosing class contexts until global or a local
6317 scope is reached. TYPE is the enclosed class. */
6319 void
6321 {
6322 /* A namespace might be passed in error cases, like A::B:C. */
6330 }
6332 /* Undoes a push_nested_class call. */
6334 void
6336 {
6342 }
6344 /* Returns the number of extern "LANG" blocks we are nested within. */
6346 int
6348 {
6350 }
6352 /* Set global variables CURRENT_LANG_NAME to appropriate value
6353 so that behavior of name-mangling machinery is correct. */
6355 void
6357 {
6361 {
6363 }
6365 {
6367 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
6368 (See record_builtin_java_type in decl.c.) However, that causes
6369 incorrect debug entries if these types are actually used.
6370 So we re-enable debug output after extern "Java". */
6379 }
6381 {
6383 }
6384 else
6386 }
6388 /* Get out of the current language scope. */
6390 void
6392 {
6394 }
6395 \f
6396 /* Type instantiation routines. */
6398 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
6399 matches the TARGET_TYPE. If there is no satisfactory match, return
6400 error_mark_node, and issue an error & warning messages under
6401 control of FLAGS. Permit pointers to member function if FLAGS
6402 permits. If TEMPLATE_ONLY, the name of the overloaded function was
6403 a template-id, and EXPLICIT_TARGS are the explicitly provided
6404 template arguments.
6406 If OVERLOAD is for one or more member functions, then ACCESS_PATH
6407 is the base path used to reference those member functions. If
6408 TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is
6409 resolved to a member function, access checks will be performed and
6410 errors issued if appropriate. */
6412 static tree
6414 tree overload,
6415 tsubst_flags_t flags,
6417 tree explicit_targs,
6418 tree access_path)
6419 {
6420 /* Here's what the standard says:
6422 [over.over]
6424 If the name is a function template, template argument deduction
6425 is done, and if the argument deduction succeeds, the deduced
6426 arguments are used to generate a single template function, which
6427 is added to the set of overloaded functions considered.
6429 Non-member functions and static member functions match targets of
6430 type "pointer-to-function" or "reference-to-function." Nonstatic
6431 member functions match targets of type "pointer-to-member
6432 function;" the function type of the pointer to member is used to
6433 select the member function from the set of overloaded member
6434 functions. If a nonstatic member function is selected, the
6435 reference to the overloaded function name is required to have the
6436 form of a pointer to member as described in 5.3.1.
6438 If more than one function is selected, any template functions in
6439 the set are eliminated if the set also contains a non-template
6440 function, and any given template function is eliminated if the
6441 set contains a second template function that is more specialized
6442 than the first according to the partial ordering rules 14.5.5.2.
6443 After such eliminations, if any, there shall remain exactly one
6444 selected function. */
6447 /* We store the matches in a TREE_LIST rooted here. The functions
6448 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
6449 interoperability with most_specialized_instantiation. */
6451 tree fn;
6452 tree target_fn_type;
6454 /* By the time we get here, we should be seeing only real
6455 pointer-to-member types, not the internal POINTER_TYPE to
6456 METHOD_TYPE representation. */
6462 /* Check that the TARGET_TYPE is reasonable. */
6466 /* This is OK, too. */
6469 /* This is OK, too. This comes from a conversion to reference
6470 type. */
6472 else
6473 {
6479 }
6481 /* Non-member functions and static member functions match targets of type
6482 "pointer-to-function" or "reference-to-function." Nonstatic member
6483 functions match targets of type "pointer-to-member-function;" the
6484 function type of the pointer to member is used to select the member
6485 function from the set of overloaded member functions.
6487 So figure out the FUNCTION_TYPE that we want to match against. */
6490 /* If we can find a non-template function that matches, we can just
6491 use it. There's no point in generating template instantiations
6492 if we're just going to throw them out anyhow. But, of course, we
6493 can only do this when we don't *need* a template function. */
6495 {
6496 tree fns;
6499 {
6503 /* We're not looking for templates just yet. */
6508 /* We're looking for a non-static member, and this isn't
6509 one, or vice versa. */
6512 /* Ignore functions which haven't been explicitly
6513 declared. */
6517 /* See if there's a match. */
6520 }
6521 }
6523 /* Now, if we've already got a match (or matches), there's no need
6524 to proceed to the template functions. But, if we don't have a
6525 match we need to look at them, too. */
6527 {
6528 tree target_arg_types;
6529 tree target_ret_type;
6530 tree fns;
6533 tree arg;
6547 {
6549 tree instantiation;
6550 tree targs;
6553 /* We're only looking for templates. */
6558 /* We're not looking for a non-static member, and this is
6559 one, or vice versa. */
6562 /* Try to do argument deduction. */
6567 /* Argument deduction failed. */
6570 /* Instantiate the template. */
6573 /* Instantiation failed. */
6576 /* See if there's a match. */
6579 }
6581 /* Now, remove all but the most specialized of the matches. */
6583 {
6588 NULL_TREE,
6589 NULL_TREE);
6590 }
6591 }
6593 /* Now we should have exactly one function in MATCHES. */
6595 {
6596 /* There were *no* matches. */
6598 {
6601 target_type);
6604 }
6606 }
6608 {
6609 /* There were too many matches. First check if they're all
6610 the same function. */
6611 tree match;
6619 {
6621 {
6624 target_type);
6626 /* Since print_candidates expects the functions in the
6627 TREE_VALUE slot, we flip them here. */
6632 }
6635 }
6636 }
6638 /* Good, exactly one match. Now, convert it to the correct type. */
6643 {
6651 {
6654 }
6655 }
6657 /* If we're doing overload resolution purely for the purpose of
6658 determining conversion sequences, we should not consider the
6659 function used. If this conversion sequence is selected, the
6660 function will be marked as used at this point. */
6662 {
6663 /* Make =delete work with SFINAE. */
6668 }
6670 /* We could not check access to member functions when this
6671 expression was originally created since we did not know at that
6672 time to which function the expression referred. */
6675 {
6678 }
6682 else
6683 {
6684 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
6685 will mark the function as addressed, but here we must do it
6686 explicitly. */
6690 }
6691 }
6693 /* This function will instantiate the type of the expression given in
6694 RHS to match the type of LHSTYPE. If errors exist, then return
6695 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
6696 we complain on errors. If we are not complaining, never modify rhs,
6697 as overload resolution wants to try many possible instantiations, in
6698 the hope that at least one will work.
6700 For non-recursive calls, LHSTYPE should be a function, pointer to
6701 function, or a pointer to member function. */
6703 tree
6705 {
6712 {
6716 }
6719 {
6725 /* Microsoft allows `A::f' to be resolved to a
6726 pointer-to-member. */
6727 ;
6728 else
6729 {
6734 }
6735 }
6738 {
6741 }
6743 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
6744 deduce any type information. */
6746 {
6750 }
6752 /* There only a few kinds of expressions that may have a type
6753 dependent on overload resolution. */
6759 /* This should really only be used when attempting to distinguish
6760 what sort of a pointer to function we have. For now, any
6761 arithmetic operation which is not supported on pointers
6762 is rejected as an error. */
6765 {
6767 {
6773 /* Do not lose object's side effects. */
6777 }
6784 /* This can happen if we are forming a pointer-to-member for a
6785 member template. */
6788 /* Fall through. */
6791 {
6795 return
6799 }
6803 return
6807 access_path);
6810 {
6815 }
6822 }
6824 }
6825 \f
6826 /* Return the name of the virtual function pointer field
6827 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6828 this may have to look back through base types to find the
6829 ultimate field name. (For single inheritance, these could
6830 all be the same name. Who knows for multiple inheritance). */
6832 static tree
6834 {
6841 {
6847 }
6855 }
6857 void
6859 {
6860 #ifdef GATHER_STATISTICS
6864 {
6869 }
6870 #endif
6871 }
6873 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6874 according to [class]:
6875 The class-name is also inserted
6876 into the scope of the class itself. For purposes of access checking,
6877 the inserted class name is treated as if it were a public member name. */
6879 void
6881 {
6884 tree saved_cas;
6899 }
6901 /* Returns 1 if TYPE contains only padding bytes. */
6903 int
6905 {
6912 /* In G++ 3.2, whether or not a class was empty was determined by
6913 looking at its size. */
6916 else
6918 }
6920 /* Returns true if TYPE contains an empty class. */
6922 static bool
6924 {
6928 {
6929 tree field;
6930 tree binfo;
6931 tree base_binfo;
6943 }
6947 }
6949 /* Returns true if TYPE contains no actual data, just various
6950 possible combinations of empty classes and possibly a vptr. */
6952 bool
6954 {
6956 {
6957 tree field;
6958 tree binfo;
6959 tree base_binfo;
6962 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
6963 out, but we'd like to be able to check this before then. */
6977 }
6981 }
6983 /* Note that NAME was looked up while the current class was being
6984 defined and that the result of that lookup was DECL. */
6986 void
6988 {
6989 splay_tree names_used;
6991 /* If we're not defining a class, there's nothing to do. */
6997 /* If there's already a binding for this NAME, then we don't have
6998 anything to worry about. */
7011 }
7013 /* Note that NAME was declared (as DECL) in the current class. Check
7014 to see that the declaration is valid. */
7016 void
7018 {
7019 splay_tree names_used;
7020 splay_tree_node n;
7022 /* Look to see if we ever used this name. */
7023 names_used
7027 /* The C language allows members to be declared with a type of the same
7028 name, and the C++ standard says this diagnostic is not required. So
7029 allow it in extern "C" blocks unless predantic is specified.
7030 Allow it in all cases if -ms-extensions is specified. */
7036 {
7037 /* [basic.scope.class]
7039 A name N used in a class S shall refer to the same declaration
7040 in its context and when re-evaluated in the completed scope of
7041 S. */
7045 }
7046 }
7048 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7049 Secondary vtables are merged with primary vtables; this function
7050 will return the VAR_DECL for the primary vtable. */
7052 tree
7054 {
7055 tree decl;
7059 {
7062 }
7066 }
7069 /* Returns the binfo for the primary base of BINFO. If the resulting
7070 BINFO is a virtual base, and it is inherited elsewhere in the
7071 hierarchy, then the returned binfo might not be the primary base of
7072 BINFO in the complete object. Check BINFO_PRIMARY_P or
7073 BINFO_LOST_PRIMARY_P to be sure. */
7075 static tree
7077 {
7078 tree primary_base;
7085 }
7087 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7089 static int
7091 {
7095 }
7097 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7098 INDENT should be zero when called from the top level; it is
7099 incremented recursively. IGO indicates the next expected BINFO in
7100 inheritance graph ordering. */
7102 static tree
7105 tree binfo,
7106 tree igo,
7108 {
7110 tree base_binfo;
7118 {
7121 }
7136 {
7140 TFF_PLAIN_IDENTIFIER),
7142 }
7144 {
7147 }
7152 {
7156 {
7160 TFF_PLAIN_IDENTIFIER));
7161 }
7163 {
7167 TFF_PLAIN_IDENTIFIER));
7168 }
7170 {
7174 TFF_PLAIN_IDENTIFIER));
7175 }
7177 {
7181 TFF_PLAIN_IDENTIFIER));
7182 }
7186 }
7192 }
7194 /* Dump the BINFO hierarchy for T. */
7196 static void
7198 {
7210 }
7212 /* Debug interface to hierarchy dumping. */
7214 void
7216 {
7218 }
7220 static void
7222 {
7227 {
7230 }
7231 }
7233 static void
7235 {
7236 tree value;
7238 HOST_WIDE_INT elt;
7246 TFF_PLAIN_IDENTIFIER));
7253 }
7255 static void
7257 {
7265 {
7272 {
7276 }
7280 }
7283 }
7285 static void
7287 {
7295 {
7300 }
7303 }
7305 /* Dump a function or thunk and its thunkees. */
7307 static void
7309 {
7312 tree thunks;
7320 {
7330 else
7336 }
7340 }
7342 /* Dump the thunks for FN. */
7344 void
7346 {
7348 }
7350 /* Virtual function table initialization. */
7352 /* Create all the necessary vtables for T and its base classes. */
7354 static void
7356 {
7357 tree vbase;
7361 /* We lay out the primary and secondary vtables in one contiguous
7362 vtable. The primary vtable is first, followed by the non-virtual
7363 secondary vtables in inheritance graph order. */
7367 /* Then come the virtual bases, also in inheritance graph order. */
7369 {
7373 }
7377 }
7379 /* Initialize the vtable for BINFO with the INITS. */
7381 static void
7383 {
7384 tree decl;
7390 }
7392 /* Build the VTT (virtual table table) for T.
7393 A class requires a VTT if it has virtual bases.
7395 This holds
7396 1 - primary virtual pointer for complete object T
7397 2 - secondary VTTs for each direct non-virtual base of T which requires a
7398 VTT
7399 3 - secondary virtual pointers for each direct or indirect base of T which
7400 has virtual bases or is reachable via a virtual path from T.
7401 4 - secondary VTTs for each direct or indirect virtual base of T.
7403 Secondary VTTs look like complete object VTTs without part 4. */
7405 static void
7407 {
7408 tree type;
7409 tree vtt;
7410 tree index;
7413 /* Build up the initializers for the VTT. */
7418 /* If we didn't need a VTT, we're done. */
7422 /* Figure out the type of the VTT. */
7426 /* Now, build the VTT object itself. */
7429 /* Add the VTT to the vtables list. */
7434 }
7436 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7437 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7438 and CHAIN the vtable pointer for this binfo after construction is
7439 complete. VALUE can also be another BINFO, in which case we recurse. */
7441 static tree
7443 {
7444 tree vt;
7447 {
7453 else
7455 }
7458 }
7460 /* Data for secondary VTT initialization. */
7462 {
7463 /* Is this the primary VTT? */
7466 /* Current index into the VTT. */
7467 tree index;
7469 /* Vector of initializers built up. */
7472 /* The type being constructed by this secondary VTT. */
7473 tree type_being_constructed;
7476 /* Recursively build the VTT-initializer for BINFO (which is in the
7477 hierarchy dominated by T). INITS points to the end of the initializer
7478 list to date. INDEX is the VTT index where the next element will be
7479 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7480 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7481 for virtual bases of T. When it is not so, we build the constructor
7482 vtables for the BINFO-in-T variant. */
7484 static void
7486 {
7488 tree b;
7489 tree init;
7490 secondary_vptr_vtt_init_data data;
7493 /* We only need VTTs for subobjects with virtual bases. */
7497 /* We need to use a construction vtable if this is not the primary
7498 VTT. */
7500 {
7503 /* Record the offset in the VTT where this sub-VTT can be found. */
7505 }
7507 /* Add the address of the primary vtable for the complete object. */
7511 {
7514 }
7517 /* Recursively add the secondary VTTs for non-virtual bases. */
7522 /* Add secondary virtual pointers for all subobjects of BINFO with
7523 either virtual bases or reachable along a virtual path, except
7524 subobjects that are non-virtual primary bases. */
7534 /* data.inits might have grown as we added secondary virtual pointers.
7535 Make sure our caller knows about the new vector. */
7539 /* Add the secondary VTTs for virtual bases in inheritance graph
7540 order. */
7542 {
7547 }
7548 else
7549 /* Remove the ctor vtables we created. */
7551 }
7553 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
7554 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
7556 static tree
7558 {
7561 /* We don't care about bases that don't have vtables. */
7565 /* We're only interested in proper subobjects of the type being
7566 constructed. */
7570 /* We're only interested in bases with virtual bases or reachable
7571 via a virtual path from the type being constructed. */
7576 /* We're not interested in non-virtual primary bases. */
7580 /* Record the index where this secondary vptr can be found. */
7582 {
7587 {
7588 /* It's a primary virtual base, and this is not a
7589 construction vtable. Find the base this is primary of in
7590 the inheritance graph, and use that base's vtable
7591 now. */
7594 }
7595 }
7597 /* Add the initializer for the secondary vptr itself. */
7600 /* Advance the vtt index. */
7605 }
7607 /* Called from build_vtt_inits via dfs_walk. After building
7608 constructor vtables and generating the sub-vtt from them, we need
7609 to restore the BINFO_VTABLES that were scribbled on. DATA is the
7610 binfo of the base whose sub vtt was generated. */
7612 static tree
7614 {
7618 /* If this class has no vtable, none of its bases do. */
7622 /* This might be a primary base, so have no vtable in this
7623 hierarchy. */
7626 /* If we scribbled the construction vtable vptr into BINFO, clear it
7627 out now. */
7633 }
7635 /* Build the construction vtable group for BINFO which is in the
7636 hierarchy dominated by T. */
7638 static void
7640 {
7641 tree type;
7642 tree vtbl;
7643 tree id;
7644 tree vbase;
7647 /* See if we've already created this construction vtable group. */
7653 /* Build a version of VTBL (with the wrong type) for use in
7654 constructing the addresses of secondary vtables in the
7655 construction vtable group. */
7663 /* Add the vtables for each of our virtual bases using the vbase in T
7664 binfo. */
7666 vbase;
7668 {
7669 tree b;
7676 }
7678 /* Figure out the type of the construction vtable. */
7686 /* Initialize the construction vtable. */
7690 }
7692 /* Add the vtbl initializers for BINFO (and its bases other than
7693 non-virtual primaries) to the list of INITS. BINFO is in the
7694 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7695 the constructor the vtbl inits should be accumulated for. (If this
7696 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7697 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7698 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7699 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7700 but are not necessarily the same in terms of layout. */
7702 static void
7704 tree orig_binfo,
7705 tree rtti_binfo,
7706 tree vtbl,
7707 tree t,
7709 {
7711 tree base_binfo;
7716 /* If it doesn't have a vptr, we don't do anything. */
7720 /* If we're building a construction vtable, we're not interested in
7721 subobjects that don't require construction vtables. */
7727 /* Build the initializers for the BINFO-in-T vtable. */
7730 /* Walk the BINFO and its bases. We walk in preorder so that as we
7731 initialize each vtable we can figure out at what offset the
7732 secondary vtable lies from the primary vtable. We can't use
7733 dfs_walk here because we need to iterate through bases of BINFO
7734 and RTTI_BINFO simultaneously. */
7736 {
7737 /* Skip virtual bases. */
7743 inits);
7744 }
7745 }
7747 /* Called from accumulate_vtbl_inits. Adds the initializers for the
7748 BINFO vtable to L. */
7750 static void
7752 tree orig_binfo,
7753 tree rtti_binfo,
7754 tree orig_vtbl,
7755 tree t,
7757 {
7764 {
7765 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7766 primary virtual base. If it is not the same primary in
7767 the hierarchy of T, we'll need to generate a ctor vtable
7768 for it, to place at its location in T. If it is the same
7769 primary, we still need a VTT entry for the vtable, but it
7770 should point to the ctor vtable for the base it is a
7771 primary for within the sub-hierarchy of RTTI_BINFO.
7773 There are three possible cases:
7775 1) We are in the same place.
7776 2) We are a primary base within a lost primary virtual base of
7777 RTTI_BINFO.
7778 3) We are primary to something not a base of RTTI_BINFO. */
7780 tree b;
7783 /* First, look through the bases we are primary to for RTTI_BINFO
7784 or a virtual base. */
7787 {
7792 }
7793 /* If we run out of primary links, keep looking down our
7794 inheritance chain; we might be an indirect primary. */
7798 found:
7800 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7801 base B and it is a base of RTTI_BINFO, this is case 2. In
7802 either case, we share our vtable with LAST, i.e. the
7803 derived-most base within B of which we are a primary. */
7806 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7807 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7808 binfo_ctor_vtable after everything's been set up. */
7811 /* Otherwise, this is case 3 and we get our own. */
7812 }
7819 {
7820 tree index;
7823 /* Add the initializer for this vtable. */
7827 /* Figure out the position to which the VPTR should point. */
7833 }
7836 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7837 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7838 straighten this out. */
7841 /* Throw away any unneeded intializers. */
7843 else
7844 /* For an ordinary vtable, set BINFO_VTABLE. */
7846 }
7850 /* Construct the initializer for BINFO's virtual function table. BINFO
7851 is part of the hierarchy dominated by T. If we're building a
7852 construction vtable, the ORIG_BINFO is the binfo we should use to
7853 find the actual function pointers to put in the vtable - but they
7854 can be overridden on the path to most-derived in the graph that
7855 ORIG_BINFO belongs. Otherwise,
7856 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7857 BINFO that should be indicated by the RTTI information in the
7858 vtable; it will be a base class of T, rather than T itself, if we
7859 are building a construction vtable.
7861 The value returned is a TREE_LIST suitable for wrapping in a
7862 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7863 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7864 number of non-function entries in the vtable.
7866 It might seem that this function should never be called with a
7867 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7868 base is always subsumed by a derived class vtable. However, when
7869 we are building construction vtables, we do build vtables for
7870 primary bases; we need these while the primary base is being
7871 constructed. */
7873 static void
7875 tree orig_binfo,
7876 tree t,
7877 tree rtti_binfo,
7880 {
7881 tree v;
7882 vtbl_init_data vid;
7884 tree vbinfo;
7888 /* Initialize VID. */
7896 /* The first vbase or vcall offset is at index -3 in the vtable. */
7899 /* Add entries to the vtable for RTTI. */
7902 /* Create an array for keeping track of the functions we've
7903 processed. When we see multiple functions with the same
7904 signature, we share the vcall offsets. */
7906 /* Add the vcall and vbase offset entries. */
7909 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7910 build_vbase_offset_vtbl_entries. */
7915 /* If the target requires padding between data entries, add that now. */
7917 {
7923 /* Move data entries into their new positions and add padding
7924 after the new positions. Iterate backwards so we don't
7925 overwrite entries that we would need to process later. */
7928 ix--)
7929 {
7937 {
7942 null_pointer_node);
7943 }
7944 }
7945 }
7950 /* The initializers for virtual functions were built up in reverse
7951 order. Straighten them out and add them to the running list in one
7952 step. */
7962 /* Go through all the ordinary virtual functions, building up
7963 initializers. */
7965 {
7966 tree delta;
7967 tree vcall_index;
7974 {
7978 {
7981 }
7983 }
7985 /* If the only definition of this function signature along our
7986 primary base chain is from a lost primary, this vtable slot will
7987 never be used, so just zero it out. This is important to avoid
7988 requiring extra thunks which cannot be generated with the function.
7990 We first check this in update_vtable_entry_for_fn, so we handle
7991 restored primary bases properly; we also need to do it here so we
7992 zero out unused slots in ctor vtables, rather than filling them
7993 with erroneous values (though harmless, apart from relocation
7994 costs). */
7999 {
8000 /* Pull the offset for `this', and the function to call, out of
8001 the list. */
8008 /* You can't call an abstract virtual function; it's abstract.
8009 So, we replace these functions with __pure_virtual. */
8011 {
8014 {
8016 abort_fndecl_addr
8020 }
8021 }
8022 else
8023 {
8025 {
8029 }
8030 /* Take the address of the function, considering it to be of an
8031 appropriate generic type. */
8035 }
8036 }
8038 /* And add it to the chain of initializers. */
8040 {
8045 else
8047 {
8053 }
8054 }
8055 else
8057 }
8058 }
8060 /* Adds to vid->inits the initializers for the vbase and vcall
8061 offsets in BINFO, which is in the hierarchy dominated by T. */
8063 static void
8065 {
8066 tree b;
8068 /* If this is a derived class, we must first create entries
8069 corresponding to the primary base class. */
8074 /* Add the vbase entries for this base. */
8076 /* Add the vcall entries for this base. */
8078 }
8080 /* Returns the initializers for the vbase offset entries in the vtable
8081 for BINFO (which is part of the class hierarchy dominated by T), in
8082 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8083 where the next vbase offset will go. */
8085 static void
8087 {
8088 tree vbase;
8089 tree t;
8090 tree non_primary_binfo;
8092 /* If there are no virtual baseclasses, then there is nothing to
8093 do. */
8099 /* We might be a primary base class. Go up the inheritance hierarchy
8100 until we find the most derived class of which we are a primary base:
8101 it is the offset of that which we need to use. */
8104 {
8105 tree b;
8107 /* If we have reached a virtual base, then it must be a primary
8108 base (possibly multi-level) of vid->binfo, or we wouldn't
8109 have called build_vcall_and_vbase_vtbl_entries for it. But it
8110 might be a lost primary, so just skip down to vid->binfo. */
8112 {
8115 }
8121 }
8123 /* Go through the virtual bases, adding the offsets. */
8125 vbase;
8127 {
8128 tree b;
8129 tree delta;
8134 /* Find the instance of this virtual base in the complete
8135 object. */
8138 /* If we've already got an offset for this virtual base, we
8139 don't need another one. */
8144 /* Figure out where we can find this vbase offset. */
8153 /* The vbase offset had better be the same. */
8156 /* The next vbase will come at a more negative offset. */
8160 /* The initializer is the delta from BINFO to this virtual base.
8161 The vbase offsets go in reverse inheritance-graph order, and
8162 we are walking in inheritance graph order so these end up in
8163 the right order. */
8170 }
8171 }
8173 /* Adds the initializers for the vcall offset entries in the vtable
8174 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8175 to VID->INITS. */
8177 static void
8179 {
8180 /* We only need these entries if this base is a virtual base. We
8181 compute the indices -- but do not add to the vtable -- when
8182 building the main vtable for a class. */
8185 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8186 correspond to VID->DERIVED), we are building a primary
8187 construction virtual table. Since this is a primary
8188 virtual table, we do not need the vcall offsets for
8189 BINFO. */
8191 {
8192 /* We need a vcall offset for each of the virtual functions in this
8193 vtable. For example:
8195 class A { virtual void f (); };
8196 class B1 : virtual public A { virtual void f (); };
8197 class B2 : virtual public A { virtual void f (); };
8198 class C: public B1, public B2 { virtual void f (); };
8200 A C object has a primary base of B1, which has a primary base of A. A
8201 C also has a secondary base of B2, which no longer has a primary base
8202 of A. So the B2-in-C construction vtable needs a secondary vtable for
8203 A, which will adjust the A* to a B2* to call f. We have no way of
8204 knowing what (or even whether) this offset will be when we define B2,
8205 so we store this "vcall offset" in the A sub-vtable and look it up in
8206 a "virtual thunk" for B2::f.
8208 We need entries for all the functions in our primary vtable and
8209 in our non-virtual bases' secondary vtables. */
8211 /* If we are just computing the vcall indices -- but do not need
8212 the actual entries -- not that. */
8215 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8217 }
8218 }
8220 /* Build vcall offsets, starting with those for BINFO. */
8222 static void
8224 {
8226 tree primary_binfo;
8227 tree base_binfo;
8229 /* Don't walk into virtual bases -- except, of course, for the
8230 virtual base for which we are building vcall offsets. Any
8231 primary virtual base will have already had its offsets generated
8232 through the recursion in build_vcall_and_vbase_vtbl_entries. */
8236 /* If BINFO has a primary base, process it first. */
8241 /* Add BINFO itself to the list. */
8244 /* Scan the non-primary bases of BINFO. */
8248 }
8250 /* Called from build_vcall_offset_vtbl_entries_r. */
8252 static void
8254 {
8255 /* Make entries for the rest of the virtuals. */
8257 {
8258 tree orig_fn;
8260 /* The ABI requires that the methods be processed in declaration
8261 order. G++ 3.2 used the order in the vtable. */
8263 orig_fn;
8267 }
8268 else
8269 {
8270 tree derived_virtuals;
8271 tree base_virtuals;
8272 tree orig_virtuals;
8273 /* If BINFO is a primary base, the most derived class which has
8274 BINFO as a primary base; otherwise, just BINFO. */
8275 tree non_primary_binfo;
8277 /* We might be a primary base class. Go up the inheritance hierarchy
8278 until we find the most derived class of which we are a primary base:
8279 it is the BINFO_VIRTUALS there that we need to consider. */
8282 {
8283 tree b;
8285 /* If we have reached a virtual base, then it must be vid->vbase,
8286 because we ignore other virtual bases in
8287 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
8288 base (possibly multi-level) of vid->binfo, or we wouldn't
8289 have called build_vcall_and_vbase_vtbl_entries for it. But it
8290 might be a lost primary, so just skip down to vid->binfo. */
8292 {
8296 }
8302 }
8305 /* For a ctor vtable we need the equivalent binfo within the hierarchy
8306 where rtti_binfo is the most derived type. */
8307 non_primary_binfo
8313 base_virtuals;
8317 {
8318 tree orig_fn;
8320 /* Find the declaration that originally caused this function to
8321 be present in BINFO_TYPE (binfo). */
8324 /* When processing BINFO, we only want to generate vcall slots for
8325 function slots introduced in BINFO. So don't try to generate
8326 one if the function isn't even defined in BINFO. */
8331 }
8332 }
8333 }
8335 /* Add a vcall offset entry for ORIG_FN to the vtable. */
8337 static void
8339 {
8341 tree vcall_offset;
8342 tree derived_entry;
8344 /* If there is already an entry for a function with the same
8345 signature as FN, then we do not need a second vcall offset.
8346 Check the list of functions already present in the derived
8347 class vtable. */
8349 {
8351 /* We only use one vcall offset for virtual destructors,
8352 even though there are two virtual table entries. */
8356 }
8358 /* If we are building these vcall offsets as part of building
8359 the vtable for the most derived class, remember the vcall
8360 offset. */
8362 {
8365 NULL);
8368 }
8370 /* The next vcall offset will be found at a more negative
8371 offset. */
8375 /* Keep track of this function. */
8379 {
8380 tree base;
8381 tree fn;
8383 /* Find the overriding function. */
8387 else
8388 {
8391 /* The vbase we're working on is a primary base of
8392 vid->binfo. But it might be a lost primary, so its
8393 BINFO_OFFSET might be wrong, so we just use the
8394 BINFO_OFFSET from vid->binfo. */
8400 vcall_offset);
8401 }
8402 /* Add the initializer to the vtable. */
8404 }
8405 }
8407 /* Return vtbl initializers for the RTTI entries corresponding to the
8408 BINFO's vtable. The RTTI entries should indicate the object given
8409 by VID->rtti_binfo. */
8411 static void
8413 {
8414 tree b;
8415 tree t;
8416 tree offset;
8417 tree decl;
8418 tree init;
8422 /* To find the complete object, we will first convert to our most
8423 primary base, and then add the offset in the vtbl to that value. */
8427 {
8428 tree primary_base;
8434 }
8438 /* The second entry is the address of the typeinfo object. */
8441 else
8444 /* Convert the declaration to a type that can be stored in the
8445 vtable. */
8449 /* Add the offset-to-top entry. It comes earlier in the vtable than
8450 the typeinfo entry. Convert the offset to look like a
8451 function pointer, so that we can put it in the vtable. */
8454 }