| blob | ce7798a8fdd4f0b727d6b6b6e836ae911623bf0b |
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, 2011
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. */
204 splay_tree_key k2);
213 /* Variables shared between class.c and call.c. */
215 #ifdef GATHER_STATISTICS
223 #endif
225 /* Convert to or from a base subobject. EXPR is an expression of type
226 `A' or `A*', an expression of type `B' or `B*' is returned. To
227 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
228 the B base instance within A. To convert base A to derived B, CODE
229 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
230 In this latter case, A must not be a morally virtual base of B.
231 NONNULL is true if EXPR is known to be non-NULL (this is only
232 needed when EXPR is of pointer type). CV qualifiers are preserved
233 from EXPR. */
235 tree
237 tree expr,
238 tree binfo,
240 tsubst_flags_t complain)
241 {
244 tree probe;
245 tree offset;
246 tree target_type;
248 tree ptr_target_type;
258 {
264 }
272 {
273 /* This can happen when adjust_result_of_qualified_name_lookup can't
274 find a unique base binfo in a call to a member function. We
275 couldn't give the diagnostic then since we might have been calling
276 a static member function, so we do it now. */
278 {
282 }
284 }
291 /* Nothing to do. */
295 {
301 }
304 /* This must happen before the call to save_expr. */
306 else
312 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
313 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
314 expression returned matches the input. */
315 target_type = cp_build_qualified_type
319 /* Do we need to look in the vtable for the real offset? */
322 /* Don't bother with the calculations inside sizeof; they'll ICE if the
323 source type is incomplete and the pointer value doesn't matter. In a
324 template (even in fold_non_dependent_expr), we don't have vtables set
325 up properly yet, and the value doesn't matter there either; we're just
326 interested in the result of overload resolution. */
328 || (current_function_decl
330 {
335 }
337 /* If we're in an NSDMI, we don't have the full constructor context yet
338 that we need for converting to a virtual base, so just build a stub
339 CONVERT_EXPR and expand it later in bot_replace. */
342 {
348 }
350 /* Do we need to check for a null pointer? */
352 {
353 /* If we know the conversion will not actually change the value
354 of EXPR, then we can avoid testing the expression for NULL.
355 We have to avoid generating a COMPONENT_REF for a base class
356 field, because other parts of the compiler know that such
357 expressions are always non-NULL. */
361 }
363 /* Protect against multiple evaluation if necessary. */
367 /* Now that we've saved expr, build the real null test. */
369 {
373 }
375 /* If this is a simple base reference, express it as a COMPONENT_REF. */
377 /* We don't build base fields for empty bases, and they aren't very
378 interesting to the optimizers anyway. */
380 {
387 }
390 {
391 /* Going via virtual base V_BINFO. We need the static offset
392 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
393 V_BINFO. That offset is an entry in D_BINFO's vtable. */
394 tree v_offset;
397 {
398 /* In a base member initializer, we cannot rely on the
399 vtable being set up. We have to indirect via the
400 vtt_parm. */
401 tree t;
407 }
408 else
410 complain),
416 v_offset);
428 /* Negative fixed_type_p means this is a constructor or destructor;
429 virtual base layout is fixed in in-charge [cd]tors, but not in
430 base [cd]tors. */
434 v_offset,
437 else
439 }
447 {
452 }
453 else
459 out:
465 }
467 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
468 Perform a derived-to-base conversion by recursively building up a
469 sequence of COMPONENT_REFs to the appropriate base fields. */
471 static tree
473 {
476 tree field;
479 {
480 tree temp;
484 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
485 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
486 an lvalue in the front end; only _DECLs and _REFs are lvalues
487 in the back end. */
493 }
495 /* Recurse. */
500 /* Is this the base field created by build_base_field? */
504 /* If we're looking for a field in the most-derived class,
505 also check the field offset; we can have two base fields
506 of the same type if one is an indirect virtual base and one
507 is a direct non-virtual base. */
511 {
512 /* We don't use build_class_member_access_expr here, as that
513 has unnecessary checks, and more importantly results in
514 recursive calls to dfs_walk_once. */
522 /* Mark the expression const or volatile, as appropriate.
523 Even though we've dealt with the type above, we still have
524 to mark the expression itself. */
531 }
533 /* Didn't find the base field?!? */
535 }
537 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
538 type is a class type or a pointer to a class type. In the former
539 case, TYPE is also a class type; in the latter it is another
540 pointer type. If CHECK_ACCESS is true, an error message is emitted
541 if TYPE is inaccessible. If OBJECT has pointer type, the value is
542 assumed to be non-NULL. */
544 tree
546 tsubst_flags_t complain)
547 {
548 tree binfo;
549 tree object_type;
550 base_access access;
553 {
556 }
557 else
564 access,
565 NULL);
570 }
572 /* EXPR is an expression with unqualified class type. BASE is a base
573 binfo of that class type. Returns EXPR, converted to the BASE
574 type. This function assumes that EXPR is the most derived class;
575 therefore virtual bases can be found at their static offsets. */
577 tree
579 {
580 tree expr_type;
584 {
585 /* If this is a non-empty base, use a COMPONENT_REF. */
589 /* We use fold_build2 and fold_convert below to simplify the trees
590 provided to the optimizers. It is not safe to call these functions
591 when processing a template because they do not handle C++-specific
592 trees. */
600 }
603 }
605 \f
606 tree
608 {
614 /* First, convert to the requested type. */
619 /* Second, the requested type may not be the owner of its own vptr.
620 If not, convert to the base class that owns it. We cannot use
621 convert_to_base here, because VCONTEXT may appear more than once
622 in the inheritance hierarchy of TYPE, and thus direct conversion
623 between the types may be ambiguous. Following the path back up
624 one step at a time via primary bases avoids the problem. */
628 {
631 }
634 }
636 /* Given an object INSTANCE, return an expression which yields the
637 vtable element corresponding to INDEX. There are many special
638 cases for INSTANCE which we take care of here, mainly to avoid
639 creating extra tree nodes when we don't have to. */
641 static tree
643 {
644 tree aref;
647 /* Try to figure out what a reference refers to, and
648 access its virtual function table directly. */
656 {
661 }
670 }
672 tree
674 {
678 }
680 /* Given a stable object pointer INSTANCE_PTR, return an expression which
681 yields a function pointer corresponding to vtable element INDEX. */
683 tree
685 {
686 tree aref;
689 tf_warning_or_error),
690 idx);
692 /* When using function descriptors, the address of the
693 vtable entry is treated as a function pointer. */
698 /* Remember this as a method reference, for later devirtualization. */
702 }
704 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
705 for the given TYPE. */
707 static tree
709 {
711 }
713 /* DECL is an entity associated with TYPE, like a virtual table or an
714 implicitly generated constructor. Determine whether or not DECL
715 should have external or internal linkage at the object file
716 level. This routine does not deal with COMDAT linkage and other
717 similar complexities; it simply sets TREE_PUBLIC if it possible for
718 entities in other translation units to contain copies of DECL, in
719 the abstract. */
721 void
723 {
726 }
728 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
729 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
730 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
732 static tree
734 {
735 tree decl;
738 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
739 now to avoid confusion in mangle_decl. */
748 /* At one time the vtable info was grabbed 2 words at a time. This
749 fails on sparc unless you have 8-byte alignment. (tiemann) */
753 /* The vtable has not been defined -- yet. */
757 /* Mark the VAR_DECL node representing the vtable itself as a
758 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
759 is rather important that such things be ignored because any
760 effort to actually generate DWARF for them will run into
761 trouble when/if we encounter code like:
763 #pragma interface
764 struct S { virtual void member (); };
766 because the artificial declaration of the vtable itself (as
767 manufactured by the g++ front end) will say that the vtable is
768 a static member of `S' but only *after* the debug output for
769 the definition of `S' has already been output. This causes
770 grief because the DWARF entry for the definition of the vtable
771 will try to refer back to an earlier *declaration* of the
772 vtable as a static member of `S' and there won't be one. We
773 might be able to arrange to have the "vtable static member"
774 attached to the member list for `S' before the debug info for
775 `S' get written (which would solve the problem) but that would
776 require more intrusive changes to the g++ front end. */
780 }
782 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
783 or even complete. If this does not exist, create it. If COMPLETE is
784 nonzero, then complete the definition of it -- that will render it
785 impossible to actually build the vtable, but is useful to get at those
786 which are known to exist in the runtime. */
788 tree
790 {
791 tree decl;
800 {
803 }
806 }
808 /* Build the primary virtual function table for TYPE. If BINFO is
809 non-NULL, build the vtable starting with the initial approximation
810 that it is the same as the one which is the head of the association
811 list. Returns a nonzero value if a new vtable is actually
812 created. */
814 static int
816 {
817 tree decl;
818 tree virtuals;
823 {
825 /* We have already created a vtable for this base, so there's
826 no need to do it again. */
833 }
834 else
835 {
838 }
840 #ifdef GATHER_STATISTICS
843 #endif
845 /* Initialize the association list for this type, based
846 on our first approximation. */
851 }
853 /* Give BINFO a new virtual function table which is initialized
854 with a skeleton-copy of its original initialization. The only
855 entry that changes is the `delta' entry, so we can really
856 share a lot of structure.
858 FOR_TYPE is the most derived type which caused this table to
859 be needed.
861 Returns nonzero if we haven't met BINFO before.
863 The order in which vtables are built (by calling this function) for
864 an object must remain the same, otherwise a binary incompatibility
865 can result. */
867 static int
869 {
871 /* We already created a vtable for this base. There's no need to
872 do it again. */
875 /* Remember that we've created a vtable for this BINFO, so that we
876 don't try to do so again. */
879 /* Make fresh virtual list, so we can smash it later. */
882 /* Secondary vtables are laid out as part of the same structure as
883 the primary vtable. */
886 }
888 /* Create a new vtable for BINFO which is the hierarchy dominated by
889 T. Return nonzero if we actually created a new vtable. */
891 static int
893 {
895 /* In this case, it is *type*'s vtable we are modifying. We start
896 with the approximation that its vtable is that of the
897 immediate base class. */
899 else
900 /* This is our very own copy of `basetype' to play with. Later,
901 we will fill in all the virtual functions that override the
902 virtual functions in these base classes which are not defined
903 by the current type. */
905 }
907 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
908 (which is in the hierarchy dominated by T) list FNDECL as its
909 BV_FN. DELTA is the required constant adjustment from the `this'
910 pointer where the vtable entry appears to the `this' required when
911 the function is actually called. */
913 static void
915 tree binfo,
916 tree fndecl,
917 tree delta,
919 {
920 tree v;
926 {
927 /* We need a new vtable for BINFO. */
929 {
930 /* If we really did make a new vtable, we also made a copy
931 of the BINFO_VIRTUALS list. Now, we have to find the
932 corresponding entry in that list. */
937 }
942 }
943 }
945 \f
946 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
947 the USING_DECL naming METHOD. Returns true if the method could be
948 added to the method vec. */
950 bool
952 {
954 tree overload;
960 tree current_fns;
961 tree fns;
974 {
975 /* Make a new method vector. We start with 8 entries. We must
976 allocate at least two (for constructors and destructors), and
977 we're going to end up with an assignment operator at some
978 point as well. */
980 /* Create slots for constructors and destructors. */
984 }
986 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
989 /* Constructors and destructors go in special slots. */
993 {
997 {
1003 type);
1004 }
1005 }
1006 else
1007 {
1008 tree m;
1011 /* See if we already have an entry with this name. */
1015 {
1018 {
1023 }
1027 {
1030 }
1035 }
1036 }
1039 /* Check to see if we've already got this method. */
1041 {
1043 tree fn_type;
1044 tree method_type;
1045 tree parms1;
1046 tree parms2;
1051 /* [over.load] Member function declarations with the
1052 same name and the same parameter types cannot be
1053 overloaded if any of them is a static member
1054 function declaration.
1056 [namespace.udecl] When a using-declaration brings names
1057 from a base class into a derived class scope, member
1058 functions in the derived class override and/or hide member
1059 functions with the same name and parameter types in a base
1060 class (rather than conflicting). */
1066 /* Compare the quals on the 'this' parm. Don't compare
1067 the whole types, as used functions are treated as
1068 coming from the using class in overload resolution. */
1077 /* For templates, the return type and template parameters
1078 must be identical. */
1095 {
1097 {
1099 /* Defer to the local function. */
1101 }
1102 else
1103 {
1106 }
1108 /* We don't call duplicate_decls here to merge the
1109 declarations because that will confuse things if the
1110 methods have inline definitions. In particular, we
1111 will crash while processing the definitions. */
1113 }
1114 }
1116 /* A class should never have more than one destructor. */
1120 /* Add the new binding. */
1131 {
1134 /* We only expect to add few methods in the COMPLETE_P case, so
1135 just make room for one more method in that case. */
1138 else
1144 else
1146 }
1147 else
1148 /* Replace the current slot. */
1151 }
1153 /* Subroutines of finish_struct. */
1155 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1156 legit, otherwise return 0. */
1158 static int
1160 {
1161 tree elem;
1170 {
1172 {
1176 else
1179 }
1180 else
1181 {
1182 /* They're changing the access to the same thing they changed
1183 it to before. That's OK. */
1184 ;
1185 }
1186 }
1187 else
1188 {
1192 }
1194 }
1196 /* Process the USING_DECL, which is a member of T. */
1198 static void
1200 {
1203 tree access
1208 tree old_value;
1213 tf_warning_or_error);
1215 {
1221 else
1223 }
1231 ;
1233 {
1235 /* It's OK to use functions from a base when there are functions with
1237 else
1238 {
1243 }
1244 }
1246 {
1250 }
1252 /* Make type T see field decl FDECL with access ACCESS. */
1255 {
1258 }
1259 else
1261 }
1262 \f
1263 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1264 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1265 properties of the bases. */
1267 static void
1271 {
1275 tree base_binfo;
1276 tree binfo;
1286 {
1295 /* If any base class is non-literal, so is the derived class. */
1299 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1300 here because the case of virtual functions but non-virtual
1301 dtor is handled in finish_struct_1. */
1306 /* If the base class doesn't have copy constructors or
1307 assignment operators that take const references, then the
1308 derived class cannot have such a member automatically
1309 generated. */
1318 /* A virtual base does not effect nearly emptiness. */
1319 ;
1321 {
1323 /* And if there is more than one nearly empty base, then the
1324 derived class is not nearly empty either. */
1326 else
1327 /* Remember we've seen one. */
1329 }
1331 /* If the base class is not empty or nearly empty, then this
1332 class cannot be nearly empty. */
1335 /* A lot of properties from the bases also apply to the derived
1336 class. */
1354 /* A standard-layout class is a class that:
1355 ...
1356 * has no non-standard-layout base classes, */
1359 {
1360 tree basefield;
1361 /* ...has no base classes of the same type as the first non-static
1362 data member... */
1364 && (same_type_ignoring_top_level_qualifiers_p
1367 else
1368 /* ...either has no non-static data members in the most-derived
1369 class and at most one base class with non-static data
1370 members, or has no base classes with non-static data
1371 members */
1375 {
1378 else
1381 }
1382 }
1384 /* Don't bother collecting tm attributes if transactional memory
1385 support is not enabled. */
1387 {
1391 }
1392 }
1394 /* If one of the base classes had TM attributes, and the current class
1395 doesn't define its own, then the current class inherits one. */
1397 {
1400 }
1401 }
1403 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1404 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1405 that have had a nearly-empty virtual primary base stolen by some
1406 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1407 T. */
1409 static void
1411 {
1415 tree base_binfo;
1417 /* Determine the primary bases of our bases. */
1420 {
1423 /* See if we're the non-virtual primary of our inheritance
1424 chain. */
1426 {
1433 /* We are the primary binfo. */
1435 }
1436 /* Determine if we have a virtual primary base, and mark it so.
1437 */
1439 {
1443 /* Someone already claimed this base. */
1445 else
1446 {
1447 tree delta;
1452 /* A virtual binfo might have been copied from within
1453 another hierarchy. As we're about to use it as a
1454 primary base, make sure the offsets match. */
1462 }
1463 }
1464 }
1466 /* First look for a dynamic direct non-virtual base. */
1468 {
1472 {
1475 }
1476 }
1478 /* A "nearly-empty" virtual base class can be the primary base
1479 class, if no non-virtual polymorphic base can be found. Look for
1480 a nearly-empty virtual dynamic base that is not already a primary
1481 base of something in the hierarchy. If there is no such base,
1482 just pick the first nearly-empty virtual base. */
1488 {
1490 {
1491 /* Found one that is not primary. */
1494 }
1496 /* Remember the first candidate. */
1498 }
1500 found:
1501 /* If we've got a primary base, use it. */
1503 {
1508 /* We are stealing a primary base. */
1512 {
1513 tree delta;
1516 /* A virtual binfo might have been copied from within
1517 another hierarchy. As we're about to use it as a primary
1518 base, make sure the offsets match. */
1523 }
1530 }
1531 }
1533 /* Update the variant types of T. */
1535 void
1537 {
1538 tree variants;
1544 variants;
1546 {
1547 /* These fields are in the _TYPE part of the node, not in
1548 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1558 /* Copy whatever these are holding today. */
1562 }
1563 }
1565 /* Early variant fixups: we apply attributes at the beginning of the class
1566 definition, and we need to fix up any variants that have already been
1567 made via elaborated-type-specifier so that check_qualified_type works. */
1569 void
1571 {
1572 tree variants;
1578 variants;
1580 {
1581 /* These are the two fields that check_qualified_type looks at and
1582 are affected by attributes. */
1585 }
1586 }
1587 \f
1588 /* Set memoizing fields and bits of T (and its variants) for later
1589 use. */
1591 static void
1593 {
1594 /* Fix up variants (if any). */
1598 /* For a class w/o baseclasses, 'finish_struct' has set
1599 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1600 Similarly for a class whose base classes do not have vtables.
1601 When neither of these is true, we might have removed abstract
1602 virtuals (by providing a definition), added some (by declaring
1603 new ones), or redeclared ones from a base class. We need to
1604 recalculate what's really an abstract virtual at this point (by
1605 looking in the vtables). */
1608 /* If this type has a copy constructor or a destructor, force its
1609 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1610 nonzero. This will cause it to be passed by invisible reference
1611 and prevent it from being returned in a register. */
1614 {
1615 tree variants;
1618 {
1621 }
1622 }
1623 }
1625 /* Issue warnings about T having private constructors, but no friends,
1626 and so forth.
1628 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1629 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1630 non-private static member functions. */
1632 static void
1634 {
1637 tree fn;
1640 /* If the class has friends, those entities might create and
1641 access instances, so we should not warn. */
1644 /* We will have warned when the template was declared; there's
1645 no need to warn on every instantiation. */
1647 /* There's no reason to even consider warning about this
1648 class. */
1651 /* We only issue one warning, if more than one applies, because
1652 otherwise, on code like:
1654 class A {
1655 // Oops - forgot `public:'
1656 A();
1657 A(const A&);
1658 ~A();
1659 };
1661 we warn several times about essentially the same problem. */
1663 /* Check to see if all (non-constructor, non-destructor) member
1664 functions are private. (Since there are no friends or
1665 non-private statics, we can't ever call any of the private member
1666 functions.) */
1668 /* We're not interested in compiler-generated methods; they don't
1669 provide any way to call private members. */
1671 {
1673 {
1675 /* A non-private static member function is just like a
1676 friend; it can create and invoke private member
1677 functions, and be accessed without a class
1678 instance. */
1682 /* Keep searching for a static member function. */
1683 }
1686 }
1689 {
1690 /* There are no non-private methods, and there's at least one
1691 private member function that isn't a constructor or
1692 destructor. (If all the private members are
1693 constructors/destructors we want to use the code below that
1694 issues error messages specifically referring to
1695 constructors/destructors.) */
1701 {
1704 }
1706 {
1710 }
1711 }
1713 /* Even if some of the member functions are non-private, the class
1714 won't be useful for much if all the constructors or destructors
1715 are private: such an object can never be created or destroyed. */
1718 {
1721 t);
1723 }
1725 /* Warn about classes that have private constructors and no friends. */
1727 /* Implicitly generated constructors are always public. */
1730 {
1733 /* If a non-template class does not define a copy
1734 constructor, one is defined for it, enabling it to avoid
1735 this warning. For a template class, this does not
1736 happen, and so we would normally get a warning on:
1738 template <class T> class C { private: C(); };
1740 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1741 complete non-template or fully instantiated classes have this
1742 flag set. */
1745 else
1747 {
1749 /* Ideally, we wouldn't count copy constructors (or, in
1750 fact, any constructor that takes an argument of the
1751 class type as a parameter) because such things cannot
1752 be used to construct an instance of the class unless
1753 you already have one. But, for now at least, we're
1754 more generous. */
1756 {
1759 }
1760 }
1763 {
1766 t);
1768 }
1769 }
1770 }
1773 gt_pointer_operator new_value;
1777 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1779 static int
1781 {
1794 }
1796 /* This routine compares two fields like method_name_cmp but using the
1797 pointer operator in resort_field_decl_data. */
1799 static int
1801 {
1810 {
1817 }
1819 }
1821 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1823 void
1826 gt_pointer_operator new_value,
1828 {
1832 tree fn;
1834 /* The type conversion ops have to live at the front of the vec, so we
1835 can't sort them. */
1843 {
1847 resort_method_name_cmp);
1848 }
1849 }
1851 /* Warn about duplicate methods in fn_fields.
1853 Sort methods that are not special (i.e., constructors, destructors,
1854 and type conversion operators) so that we can find them faster in
1855 search. */
1857 static void
1859 {
1860 tree fn_fields;
1870 /* Clear DECL_IN_AGGR_P for all functions. */
1875 /* Issue warnings about private constructors and such. If there are
1876 no methods, then some public defaults are generated. */
1879 /* The type conversion ops have to live at the front of the vec, so we
1880 can't sort them. */
1889 }
1891 /* Make BINFO's vtable have N entries, including RTTI entries,
1892 vbase and vcall offsets, etc. Set its type and call the back end
1893 to lay it out. */
1895 static void
1897 {
1898 tree atype;
1899 tree vtable;
1904 /* We may have to grow the vtable. */
1907 {
1911 }
1912 }
1914 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1915 have the same signature. */
1917 int
1919 {
1920 /* One destructor overrides another if they are the same kind of
1921 destructor. */
1925 /* But a non-destructor never overrides a destructor, nor vice
1926 versa, nor do different kinds of destructors override
1927 one-another. For example, a complete object destructor does not
1928 override a deleting destructor. */
1937 {
1945 }
1947 }
1949 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1950 subobject. */
1952 static bool
1954 {
1955 tree probe;
1958 {
1962 /* If we meet a virtual base, we can't follow the inheritance
1963 any more. See if the complete type of DERIVED contains
1964 such a virtual base. */
1967 }
1969 }
1972 /* The function for which we are trying to find a final overrider. */
1973 tree fn;
1974 /* The base class in which the function was declared. */
1975 tree declaring_base;
1976 /* The candidate overriders. */
1977 tree candidates;
1978 /* Path to most derived. */
1982 /* Add the overrider along the current path to FFOD->CANDIDATES.
1983 Returns true if an overrider was found; false otherwise. */
1985 static bool
1989 {
1990 tree method;
1992 /* If BINFO is not the most derived type, try a more derived class.
1993 A definition there will overrider a definition here. */
1995 {
1996 depth--;
2000 }
2004 {
2007 /* Remove any candidates overridden by this new function. */
2009 {
2010 /* If *CANDIDATE overrides METHOD, then METHOD
2011 cannot override anything else on the list. */
2014 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2017 else
2019 }
2021 /* Add the new function. */
2024 }
2027 }
2029 /* Called from find_final_overrider via dfs_walk. */
2031 static tree
2033 {
2041 }
2043 static tree
2045 {
2050 }
2052 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2053 FN and whose TREE_VALUE is the binfo for the base where the
2054 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2055 DERIVED) is the base object in which FN is declared. */
2057 static tree
2059 {
2060 find_final_overrider_data ffod;
2062 /* Getting this right is a little tricky. This is valid:
2064 struct S { virtual void f (); };
2065 struct T { virtual void f (); };
2066 struct U : public S, public T { };
2068 even though calling `f' in `U' is ambiguous. But,
2070 struct R { virtual void f(); };
2071 struct S : virtual public R { virtual void f (); };
2072 struct T : virtual public R { virtual void f (); };
2073 struct U : public S, public T { };
2075 is not -- there's no way to decide whether to put `S::f' or
2076 `T::f' in the vtable for `R'.
2078 The solution is to look at all paths to BINFO. If we find
2079 different overriders along any two, then there is a problem. */
2083 /* Determine the depth of the hierarchy. */
2094 /* If there was no winner, issue an error message. */
2099 }
2101 /* Return the index of the vcall offset for FN when TYPE is used as a
2102 virtual base. */
2104 static tree
2106 {
2108 tree_pair_p p;
2116 /* There should always be an appropriate index. */
2118 }
2120 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2121 dominated by T. FN is the old function; VIRTUALS points to the
2122 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2123 of that entry in the list. */
2125 static void
2128 {
2129 tree b;
2130 tree overrider;
2131 tree delta;
2132 tree virtual_base;
2133 tree first_defn;
2139 /* Find the nearest primary base (possibly binfo itself) which defines
2140 this function; this is the class the caller will convert to when
2141 calling FN through BINFO. */
2143 {
2148 /* The nearest definition is from a lost primary. */
2151 }
2154 /* Find the final overrider. */
2157 {
2160 }
2163 /* Check for adjusting covariant return types. */
2171 /* If the overrider is invalid, don't even try. */
2173 {
2174 /* If FN is a covariant thunk, we must figure out the adjustment
2175 to the final base FN was converting to. As OVERRIDER_TARGET might
2176 also be converting to the return type of FN, we have to
2177 combine the two conversions here. */
2184 {
2188 }
2189 else
2193 /* Find the equivalent binfo within the return type of the
2194 overriding function. We will want the vbase offset from
2195 there. */
2197 over_return);
2200 {
2201 /* There was no existing virtual thunk (which takes
2202 precedence). So find the binfo of the base function's
2203 return type within the overriding function's return type.
2204 We cannot call lookup base here, because we're inside a
2205 dfs_walk, and will therefore clobber the BINFO_MARKED
2206 flags. Fortunately we know the covariancy is valid (it
2207 has already been checked), so we can just iterate along
2208 the binfos, which have been chained in inheritance graph
2209 order. Of course it is lame that we have to repeat the
2210 search here anyway -- we should really be caching pieces
2211 of the vtable and avoiding this repeated work. */
2214 /* Find the base binfo within the overriding function's
2215 return type. We will always find a thunk_binfo, except
2216 when the covariancy is invalid (which we will have
2217 already diagnosed). */
2220 thunk_binfo;
2226 /* See if virtual inheritance is involved. */
2228 virtual_offset;
2235 {
2239 {
2240 /* We convert via virtual base. Adjust the fixed
2241 offset to be from there. */
2242 offset =
2246 }
2248 /* There was an existing fixed offset, this must be
2249 from the base just converted to, and the base the
2250 FN was thunking to. */
2252 else
2254 }
2255 }
2258 /* Replace the overriding function with a covariant thunk. We
2259 will emit the overriding function in its own slot as
2260 well. */
2263 }
2264 else
2268 /* If we need a covariant thunk, then we may need to adjust first_defn.
2269 The ABI specifies that the thunks emitted with a function are
2270 determined by which bases the function overrides, so we need to be
2271 sure that we're using a thunk for some overridden base; even if we
2272 know that the necessary this adjustment is zero, there may not be an
2273 appropriate zero-this-adjusment thunk for us to use since thunks for
2274 overriding virtual bases always use the vcall offset.
2276 Furthermore, just choosing any base that overrides this function isn't
2277 quite right, as this slot won't be used for calls through a type that
2278 puts a covariant thunk here. Calling the function through such a type
2279 will use a different slot, and that slot is the one that determines
2280 the thunk emitted for that base.
2282 So, keep looking until we find the base that we're really overriding
2283 in this slot: the nearest primary base that doesn't use a covariant
2284 thunk in this slot. */
2286 {
2288 /* We already know that the overrider needs a covariant thunk. */
2291 {
2298 }
2300 }
2302 /* Assume that we will produce a thunk that convert all the way to
2303 the final overrider, and not to an intermediate virtual base. */
2306 /* See if we can convert to an intermediate virtual base first, and then
2307 use the vcall offset located there to finish the conversion. */
2309 {
2310 /* If we find the final overrider, then we can stop
2311 walking. */
2316 /* If we find a virtual base, and we haven't yet found the
2317 overrider, then there is a virtual base between the
2318 declaring base (first_defn) and the final overrider. */
2320 {
2323 }
2324 }
2326 /* Compute the constant adjustment to the `this' pointer. The
2327 `this' pointer, when this function is called, will point at BINFO
2328 (or one of its primary bases, which are at the same offset). */
2330 /* The `this' pointer needs to be adjusted from the declaration to
2331 the nearest virtual base. */
2336 /* If the nearest definition is in a lost primary, we don't need an
2337 entry in our vtable. Except possibly in a constructor vtable,
2338 if we happen to get our primary back. In that case, the offset
2339 will be zero, as it will be a primary base. */
2341 else
2342 /* The `this' pointer needs to be adjusted from pointing to
2343 BINFO to pointing at the base where the final overrider
2344 appears. */
2355 else
2359 }
2361 /* Called from modify_all_vtables via dfs_walk. */
2363 static tree
2365 {
2367 tree virtuals;
2368 tree old_virtuals;
2372 /* A base without a vtable needs no modification, and its bases
2373 are uninteresting. */
2378 /* Don't do the primary vtable, if it's new. */
2382 /* There's no need to modify the vtable for a non-virtual primary
2383 base; we're not going to use that vtable anyhow. We do still
2384 need to do this for virtual primary bases, as they could become
2385 non-primary in a construction vtable. */
2390 /* Now, go through each of the virtual functions in the virtual
2391 function table for BINFO. Find the final overrider, and update
2392 the BINFO_VIRTUALS list appropriately. */
2395 virtuals;
2399 binfo,
2404 }
2406 /* Update all of the primary and secondary vtables for T. Create new
2407 vtables as required, and initialize their RTTI information. Each
2408 of the functions in VIRTUALS is declared in T and may override a
2409 virtual function from a base class; find and modify the appropriate
2410 entries to point to the overriding functions. Returns a list, in
2411 declaration order, of the virtual functions that are declared in T,
2412 but do not appear in the primary base class vtable, and which
2413 should therefore be appended to the end of the vtable for T. */
2415 static tree
2417 {
2421 /* Update all of the vtables. */
2424 /* Add virtual functions not already in our primary vtable. These
2425 will be both those introduced by this class, and those overridden
2426 from secondary bases. It does not include virtuals merely
2427 inherited from secondary bases. */
2429 {
2434 {
2435 /* We don't need to adjust the `this' pointer when
2436 calling this function. */
2440 /* This is a function not already in our vtable. Keep it. */
2442 }
2443 else
2444 /* We've already got an entry for this function. Skip it. */
2446 }
2449 }
2451 /* Get the base virtual function declarations in T that have the
2452 indicated NAME. */
2454 static tree
2456 {
2457 tree methods;
2462 /* Find virtual functions in T with the indicated NAME. */
2466 methods;
2468 {
2474 }
2480 {
2483 base_fndecls);
2484 }
2487 }
2489 /* If this declaration supersedes the declaration of
2490 a method declared virtual in the base class, then
2491 mark this field as being virtual as well. */
2493 void
2495 {
2498 /* In [temp.mem] we have:
2500 A specialization of a member function template does not
2501 override a virtual function from a base class. */
2508 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2509 the error_mark_node so that we know it is an overriding
2510 function. */
2511 {
2514 }
2517 {
2523 }
2528 }
2530 /* Warn about hidden virtual functions that are not overridden in t.
2531 We know that constructors and destructors don't apply. */
2533 static void
2535 {
2537 tree fns;
2540 /* We go through each separately named virtual function. */
2544 {
2545 tree fn;
2546 tree name;
2547 tree fndecl;
2548 tree base_fndecls;
2549 tree base_binfo;
2550 tree binfo;
2553 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2554 have the same name. Figure out what name that is. */
2556 /* There are no possibly hidden functions yet. */
2558 /* Iterate through all of the base classes looking for possibly
2559 hidden functions. */
2562 {
2565 base_fndecls);
2566 }
2568 /* If there are no functions to hide, continue. */
2572 /* Remove any overridden functions. */
2574 {
2577 {
2581 /* If the method from the base class has the same
2582 signature as the method from the derived class, it
2583 has been overridden. */
2586 else
2588 }
2589 }
2591 /* Now give a warning for all base functions without overriders,
2592 as they are hidden. */
2594 {
2595 /* Here we know it is a hider, and no overrider exists. */
2599 }
2600 }
2601 }
2603 /* Check for things that are invalid. There are probably plenty of other
2604 things we should check for also. */
2606 static void
2608 {
2609 tree field;
2612 {
2620 {
2624 {
2625 /* We're generally only interested in entities the user
2626 declared, but we also find nested classes by noticing
2627 the TYPE_DECL that we create implicitly. You're
2628 allowed to put one anonymous union inside another,
2629 though, so we explicitly tolerate that. We use
2630 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2631 we also allow unnamed types used for defining fields. */
2638 {
2642 else
2646 }
2649 {
2652 else
2654 }
2656 {
2659 else
2661 }
2665 }
2666 }
2667 }
2668 }
2670 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2671 will be used later during class template instantiation.
2672 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2673 a non-static member data (FIELD_DECL), a member function
2674 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2675 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2676 When FRIEND_P is nonzero, T is either a friend class
2677 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2678 (FUNCTION_DECL, TEMPLATE_DECL). */
2680 void
2682 {
2683 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2688 }
2690 /* This function is called from declare_virt_assop_and_dtor via
2691 dfs_walk_all.
2693 DATA is a type that direcly or indirectly inherits the base
2694 represented by BINFO. If BINFO contains a virtual assignment [copy
2695 assignment or move assigment] operator or a virtual constructor,
2696 declare that function in DATA if it hasn't been already declared. */
2698 static tree
2700 {
2708 /* A base without a vtable needs no modification, and its bases
2709 are uninteresting. */
2713 /* If this is a primary base, then we have already looked at the
2714 virtual functions of its vtable. */
2718 {
2722 {
2727 }
2731 }
2734 }
2736 /* If the class type T has a direct or indirect base that contains a
2737 virtual assignment operator or a virtual destructor, declare that
2738 function in T if it hasn't been already declared. */
2740 static void
2742 {
2750 dfs_declare_virt_assop_and_dtor,
2752 }
2754 /* Create default constructors, assignment operators, and so forth for
2755 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2756 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2757 the class cannot have a default constructor, copy constructor
2758 taking a const reference argument, or an assignment operator taking
2759 a const reference, respectively. */
2761 static void
2765 {
2773 /* Destructor. */
2775 {
2776 /* In general, we create destructors lazily. */
2781 /* But if this is a Java class, any non-trivial destructor is
2782 invalid, even if compiler-generated. Therefore, if the
2783 destructor is non-trivial we create it now. */
2785 }
2787 /* [class.ctor]
2789 If there is no user-declared constructor for a class, a default
2790 constructor is implicitly declared. */
2792 {
2797 /* This might force the declaration. */
2799 }
2801 /* [class.ctor]
2803 If a class definition does not explicitly declare a copy
2804 constructor, one is declared implicitly. */
2806 {
2812 }
2814 /* If there is no assignment operator, one will be created if and
2815 when it is needed. For now, just record whether or not the type
2816 of the parameter to the assignment operator will be a const or
2817 non-const reference. */
2819 {
2825 }
2827 /* We can't be lazy about declaring functions that might override
2828 a virtual function from a base class. */
2830 }
2832 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
2833 count the number of fields in TYPE, including anonymous union
2834 members. */
2836 static int
2838 {
2839 tree x;
2842 {
2845 else
2847 }
2849 }
2851 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
2852 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
2853 elts, starting at offset IDX. */
2855 static int
2857 {
2858 tree x;
2860 {
2863 else
2865 }
2867 }
2869 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
2870 starting at offset IDX. */
2872 static int
2876 {
2877 tree values;
2881 }
2883 /* FIELD is a bit-field. We are finishing the processing for its
2884 enclosing type. Issue any appropriate messages and set appropriate
2885 flags. Returns false if an error has been diagnosed. */
2887 static bool
2889 {
2891 tree w;
2893 /* Extract the declared width of the bitfield, which has been
2894 temporarily stashed in DECL_INITIAL. */
2897 /* Remove the bit-field width indicator so that the rest of the
2898 compiler does not treat that value as an initializer. */
2901 /* Detect invalid bit-field type. */
2903 {
2906 }
2907 else
2908 {
2910 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2913 /* detect invalid field size. */
2919 {
2922 }
2924 {
2927 }
2929 {
2932 }
2941 }
2944 {
2948 }
2949 else
2950 {
2951 /* Non-bit-fields are aligned for their type. */
2955 }
2956 }
2958 /* FIELD is a non bit-field. We are finishing the processing for its
2959 enclosing type T. Issue any appropriate messages and set appropriate
2960 flags. */
2962 static void
2964 tree t,
2968 {
2971 /* In C++98 an anonymous union cannot contain any fields which would change
2972 the settings of CANT_HAVE_CONST_CTOR and friends. */
2974 ;
2975 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
2976 structs. So, we recurse through their fields here. */
2978 {
2979 tree fields;
2985 }
2986 /* Check members with class type for constructors, destructors,
2987 etc. */
2989 {
2990 /* Never let anything with uninheritable virtuals
2991 make it through without complaint. */
2995 {
3000 field);
3005 field);
3007 {
3011 }
3012 }
3013 else
3014 {
3027 }
3036 }
3038 {
3039 /* `build_class_init_list' does not recognize
3040 non-FIELD_DECLs. */
3044 }
3045 }
3047 /* Check the data members (both static and non-static), class-scoped
3048 typedefs, etc., appearing in the declaration of T. Issue
3049 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3050 declaration order) of access declarations; each TREE_VALUE in this
3051 list is a USING_DECL.
3053 In addition, set the following flags:
3055 EMPTY_P
3056 The class is empty, i.e., contains no non-static data members.
3058 CANT_HAVE_CONST_CTOR_P
3059 This class cannot have an implicitly generated copy constructor
3060 taking a const reference.
3062 CANT_HAVE_CONST_ASN_REF
3063 This class cannot have an implicitly generated assignment
3064 operator taking a const reference.
3066 All of these flags should be initialized before calling this
3067 function.
3069 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3070 fields can be added by adding to this chain. */
3072 static void
3076 {
3084 /* Assume there are no access declarations. */
3086 /* Assume this class has no pointer members. */
3088 /* Assume none of the members of this class have default
3089 initializations. */
3093 {
3101 {
3102 /* Save the access declarations for our caller. */
3105 }
3111 /* If we've gotten this far, it's a data member, possibly static,
3112 or an enumerator. */
3115 /* When this goes into scope, it will be a non-local reference. */
3119 {
3120 /* [class.union]
3122 If a union contains a static data member, or a member of
3123 reference type, the program is ill-formed. */
3125 {
3128 }
3130 {
3135 }
3136 }
3138 /* Perform error checking that did not get done in
3139 grokdeclarator. */
3141 {
3145 }
3147 {
3151 }
3159 /* Now it can only be a FIELD_DECL. */
3164 /* If at least one non-static data member is non-literal, the whole
3165 class becomes non-literal. Note: if the type is incomplete we
3166 will complain later on. */
3170 /* A standard-layout class is a class that:
3171 ...
3172 has the same access control (Clause 11) for all non-static data members,
3173 ... */
3180 /* If this is of reference type, check if it needs an init. */
3182 {
3188 /* ARM $12.6.2: [A member initializer list] (or, for an
3189 aggregate, initialization by a brace-enclosed list) is the
3190 only way to initialize nonstatic const and reference
3191 members. */
3194 }
3199 {
3201 {
3202 warning
3205 x);
3207 }
3211 }
3214 /* We don't treat zero-width bitfields as making a class
3215 non-empty. */
3216 ;
3217 else
3218 {
3219 /* The class is non-empty. */
3221 /* The class is not even nearly empty. */
3223 /* If one of the data members contains an empty class,
3224 so does T. */
3228 }
3230 /* This is used by -Weffc++ (see below). Warn only for pointers
3231 to members which might hold dynamic memory. So do not warn
3232 for pointers to functions or pointers to members. */
3239 {
3244 }
3250 /* DR 148 now allows pointers to members (which are POD themselves),
3251 to be allowed in POD structs. */
3260 /* We set DECL_C_BIT_FIELD in grokbitfield.
3261 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3264 cant_have_const_ctor_p,
3265 no_const_asn_ref_p,
3268 /* Now that we've removed bit-field widths from DECL_INITIAL,
3269 anything left in DECL_INITIAL is an NSDMI that makes the class
3270 non-aggregate. */
3274 /* If any field is const, the structure type is pseudo-const. */
3276 {
3281 /* ARM $12.6.2: [A member initializer list] (or, for an
3282 aggregate, initialization by a brace-enclosed list) is the
3283 only way to initialize nonstatic const and reference
3284 members. */
3287 }
3288 /* A field that is pseudo-const makes the structure likewise. */
3290 {
3295 }
3297 /* Core issue 80: A nonstatic data member is required to have a
3298 different name from the class iff the class has a
3299 user-declared constructor. */
3303 }
3305 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3306 it should also define a copy constructor and an assignment operator to
3307 implement the correct copy semantic (deep vs shallow, etc.). As it is
3308 not feasible to check whether the constructors do allocate dynamic memory
3309 and store it within members, we approximate the warning like this:
3311 -- Warn only if there are members which are pointers
3312 -- Warn only if there is a non-trivial constructor (otherwise,
3313 there cannot be memory allocated).
3314 -- Warn only if there is a non-trivial destructor. We assume that the
3315 user at least implemented the cleanup correctly, and a destructor
3316 is needed to free dynamic memory.
3318 This seems enough for practical purposes. */
3320 && has_pointers
3324 {
3328 {
3333 }
3337 }
3339 /* Non-static data member initializers make the default constructor
3340 non-trivial. */
3342 {
3345 }
3347 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3351 /* Check anonymous struct/anonymous union fields. */
3354 /* We've built up the list of access declarations in reverse order.
3355 Fix that now. */
3357 }
3359 /* If TYPE is an empty class type, records its OFFSET in the table of
3360 OFFSETS. */
3362 static int
3364 {
3365 splay_tree_node n;
3370 /* Record the location of this empty object in OFFSETS. */
3378 type,
3382 }
3384 /* Returns nonzero if TYPE is an empty class type and there is
3385 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3387 static int
3389 {
3390 splay_tree_node n;
3391 tree t;
3396 /* Record the location of this empty object in OFFSETS. */
3406 }
3408 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3409 F for every subobject, passing it the type, offset, and table of
3410 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3411 be traversed.
3413 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3414 than MAX_OFFSET will not be walked.
3416 If F returns a nonzero value, the traversal ceases, and that value
3417 is returned. Otherwise, returns zero. */
3419 static int
3421 subobject_offset_fn f,
3422 tree offset,
3423 splay_tree offsets,
3424 tree max_offset,
3426 {
3430 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3431 stop. */
3439 {
3443 }
3446 {
3447 tree field;
3448 tree binfo;
3451 /* Avoid recursing into objects that are not interesting. */
3455 /* Record the location of TYPE. */
3460 /* Iterate through the direct base classes of TYPE. */
3464 {
3465 tree binfo_offset;
3478 offset,
3480 else
3481 {
3482 tree orig_binfo;
3483 /* We cannot rely on BINFO_OFFSET being set for the base
3484 class yet, but the offsets for direct non-virtual
3485 bases can be calculated by going back to the TYPE. */
3488 offset,
3490 }
3493 f,
3494 binfo_offset,
3495 offsets,
3496 max_offset,
3501 }
3504 {
3508 /* Iterate through the virtual base classes of TYPE. In G++
3509 3.2, we included virtual bases in the direct base class
3510 loop above, which results in incorrect results; the
3511 correct offsets for virtual bases are only known when
3512 working with the most derived type. */
3516 {
3518 f,
3520 offset,
3522 offsets,
3523 max_offset,
3527 }
3528 else
3529 {
3530 /* We still have to walk the primary base, if it is
3531 virtual. (If it is non-virtual, then it was walked
3532 above.) */
3538 {
3539 r = (walk_subobject_offsets
3544 }
3545 }
3546 }
3548 /* Iterate through the fields of TYPE. */
3551 {
3552 tree field_offset;
3556 else
3557 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3561 f,
3563 offset,
3564 field_offset),
3565 offsets,
3566 max_offset,
3570 }
3571 }
3573 {
3576 tree index;
3578 /* Avoid recursing into objects that are not interesting. */
3583 /* Step through each of the elements in the array. */
3585 /* G++ 3.2 had an off-by-one error here. */
3590 {
3592 f,
3593 offset,
3594 offsets,
3595 max_offset,
3601 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3602 there's no point in iterating through the remaining
3603 elements of the array. */
3606 }
3607 }
3610 }
3612 /* Record all of the empty subobjects of TYPE (either a type or a
3613 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3614 is being placed at OFFSET; otherwise, it is a base class that is
3615 being placed at OFFSET. */
3617 static void
3619 tree offset,
3620 splay_tree offsets,
3622 {
3623 tree max_offset;
3624 /* If recording subobjects for a non-static data member or a
3625 non-empty base class , we do not need to record offsets beyond
3626 the size of the biggest empty class. Additional data members
3627 will go at the end of the class. Additional base classes will go
3628 either at offset zero (if empty, in which case they cannot
3629 overlap with offsets past the size of the biggest empty class) or
3630 at the end of the class.
3632 However, if we are placing an empty base class, then we must record
3633 all offsets, as either the empty class is at offset zero (where
3634 other empty classes might later be placed) or at the end of the
3635 class (where other objects might then be placed, so other empty
3636 subobjects might later overlap). */
3640 else
3644 }
3646 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3647 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3648 virtual bases of TYPE are examined. */
3650 static int
3652 tree offset,
3653 splay_tree offsets,
3655 {
3656 splay_tree_node max_node;
3658 /* Get the node in OFFSETS that indicates the maximum offset where
3659 an empty subobject is located. */
3661 /* If there aren't any empty subobjects, then there's no point in
3662 performing this check. */
3668 vbases_p);
3669 }
3671 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3672 non-static data member of the type indicated by RLI. BINFO is the
3673 binfo corresponding to the base subobject, OFFSETS maps offsets to
3674 types already located at those offsets. This function determines
3675 the position of the DECL. */
3677 static void
3679 tree decl,
3680 tree binfo,
3681 splay_tree offsets)
3682 {
3685 tree type;
3688 {
3689 /* For the purposes of determining layout conflicts, we want to
3690 use the class type of BINFO; TREE_TYPE (DECL) will be the
3691 CLASSTYPE_AS_BASE version, which does not contain entries for
3692 zero-sized bases. */
3695 }
3696 else
3697 {
3700 }
3702 /* Try to place the field. It may take more than one try if we have
3703 a hard time placing the field without putting two objects of the
3704 same type at the same address. */
3706 {
3709 /* Place this field. */
3713 /* We have to check to see whether or not there is already
3714 something of the same type at the offset we're about to use.
3715 For example, consider:
3717 struct S {};
3718 struct T : public S { int i; };
3719 struct U : public S, public T {};
3721 Here, we put S at offset zero in U. Then, we can't put T at
3722 offset zero -- its S component would be at the same address
3723 as the S we already allocated. So, we have to skip ahead.
3724 Since all data members, including those whose type is an
3725 empty class, have nonzero size, any overlap can happen only
3726 with a direct or indirect base-class -- it can't happen with
3727 a data member. */
3728 /* In a union, overlap is permitted; all members are placed at
3729 offset zero. */
3732 /* G++ 3.2 did not check for overlaps when placing a non-empty
3733 virtual base. */
3738 {
3739 /* Strip off the size allocated to this field. That puts us
3740 at the first place we could have put the field with
3741 proper alignment. */
3744 /* Bump up by the alignment required for the type. */
3745 rli->bitpos
3751 }
3752 else
3753 /* There was no conflict. We're done laying out this field. */
3755 }
3757 /* Now that we know where it will be placed, update its
3758 BINFO_OFFSET. */
3760 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3761 this point because their BINFO_OFFSET is copied from another
3762 hierarchy. Therefore, we may not need to add the entire
3763 OFFSET. */
3769 }
3771 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3773 static int
3775 tree offset,
3776 splay_tree offsets ATTRIBUTE_UNUSED)
3777 {
3779 }
3781 /* Layout the empty base BINFO. EOC indicates the byte currently just
3782 past the end of the class, and should be correctly aligned for a
3783 class of the type indicated by BINFO; OFFSETS gives the offsets of
3784 the empty bases allocated so far. T is the most derived
3785 type. Return nonzero iff we added it at the end. */
3787 static bool
3790 {
3791 tree alignment;
3795 /* This routine should only be used for empty classes. */
3800 {
3802 propagate_binfo_offsets
3805 else
3807 "offset of empty base %qT may not be ABI-compliant and may"
3810 }
3812 /* This is an empty base class. We first try to put it at offset
3813 zero. */
3816 offsets,
3818 {
3819 /* That didn't work. Now, we move forward from the next
3820 available spot in the class. */
3824 {
3827 offsets,
3829 /* We finally found a spot where there's no overlap. */
3832 /* There's overlap here, too. Bump along to the next spot. */
3834 }
3835 }
3838 {
3843 }
3846 }
3848 /* Layout the base given by BINFO in the class indicated by RLI.
3849 *BASE_ALIGN is a running maximum of the alignments of
3850 any base class. OFFSETS gives the location of empty base
3851 subobjects. T is the most derived type. Return nonzero if the new
3852 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3853 *NEXT_FIELD, unless BINFO is for an empty base class.
3855 Returns the location at which the next field should be inserted. */
3860 {
3865 /* This error is now reported in xref_tag, thus giving better
3866 location information. */
3869 /* Place the base class. */
3871 {
3872 tree decl;
3874 /* The containing class is non-empty because it has a non-empty
3875 base class. */
3878 /* Create the FIELD_DECL. */
3885 {
3893 /* Try to place the field. It may take more than one try if we
3894 have a hard time placing the field without putting two
3895 objects of the same type at the same address. */
3897 /* Add the new FIELD_DECL to the list of fields for T. */
3901 }
3902 }
3903 else
3904 {
3905 tree eoc;
3908 /* On some platforms (ARM), even empty classes will not be
3909 byte-aligned. */
3914 /* A nearly-empty class "has no proper base class that is empty,
3915 not morally virtual, and at an offset other than zero." */
3917 {
3920 /* The check above (used in G++ 3.2) is insufficient because
3921 an empty class placed at offset zero might itself have an
3922 empty base at a nonzero offset. */
3924 empty_base_at_nonzero_offset_p,
3925 size_zero_node,
3929 {
3932 else
3934 "class %qT will be considered nearly empty in a "
3936 }
3937 }
3939 /* We do not create a FIELD_DECL for empty base classes because
3940 it might overlap some other field. We want to be able to
3941 create CONSTRUCTORs for the class by iterating over the
3942 FIELD_DECLs, and the back end does not handle overlapping
3943 FIELD_DECLs. */
3945 /* An empty virtual base causes a class to be non-empty
3946 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3947 here because that was already done when the virtual table
3948 pointer was created. */
3949 }
3951 /* Record the offsets of BINFO and its base subobjects. */
3954 offsets,
3958 }
3960 /* Layout all of the non-virtual base classes. Record empty
3961 subobjects in OFFSETS. T is the most derived type. Return nonzero
3962 if the type cannot be nearly empty. The fields created
3963 corresponding to the base classes will be inserted at
3964 *NEXT_FIELD. */
3966 static void
3969 {
3970 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3971 subobjects. */
3976 /* The primary base class is always allocated first. */
3981 /* Now allocate the rest of the bases. */
3983 {
3984 tree base_binfo;
3988 /* The primary base was already allocated above, so we don't
3989 need to allocate it again here. */
3993 /* Virtual bases are added at the end (a primary virtual base
3994 will have already been added). */
4000 }
4001 }
4003 /* Go through the TYPE_METHODS of T issuing any appropriate
4004 diagnostics, figuring out which methods override which other
4005 methods, and so forth. */
4007 static void
4009 {
4010 tree x;
4013 {
4017 /* The name of the field is the original field name
4018 Save this in auxiliary field for later overloading. */
4020 {
4024 }
4025 /* All user-provided destructors are non-trivial.
4026 Constructors and assignment ops are handled in
4027 grok_special_member_properties. */
4030 }
4031 }
4033 /* FN is a constructor or destructor. Clone the declaration to create
4034 a specialized in-charge or not-in-charge version, as indicated by
4035 NAME. */
4037 static tree
4039 {
4040 tree parms;
4041 tree clone;
4043 /* Copy the function. */
4045 /* Reset the function name. */
4048 /* Remember where this function came from. */
4050 /* Make it easy to find the CLONE given the FN. */
4054 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4056 {
4063 }
4066 /* There's no pending inline data for this function. */
4070 /* The base-class destructor is not virtual. */
4072 {
4076 }
4078 /* If there was an in-charge parameter, drop it from the function
4079 type. */
4081 {
4082 tree basetype;
4083 tree parmtypes;
4084 tree exceptions;
4089 /* Skip the `this' parameter. */
4091 /* Skip the in-charge parameter. */
4093 /* And the VTT parm, in a complete [cd]tor. */
4097 /* If this is subobject constructor or destructor, add the vtt
4098 parameter. */
4102 parmtypes);
4105 exceptions);
4109 }
4111 /* Copy the function parameters. */
4113 /* Remove the in-charge parameter. */
4115 {
4119 }
4120 /* And the VTT parm, in a complete [cd]tor. */
4122 {
4125 else
4126 {
4130 }
4131 }
4134 {
4137 }
4139 /* Create the RTL for this function. */
4147 }
4149 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4150 not invoke this function directly.
4152 For a non-thunk function, returns the address of the slot for storing
4153 the function it is a clone of. Otherwise returns NULL_TREE.
4155 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4156 cloned_function is unset. This is to support the separate
4157 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4158 on a template makes sense, but not the former. */
4160 tree *
4162 {
4170 {
4171 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4174 else
4175 #endif
4177 }
4182 else
4184 }
4186 /* Produce declarations for all appropriate clones of FN. If
4187 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4188 CLASTYPE_METHOD_VEC as well. */
4190 void
4192 {
4193 tree clone;
4195 /* Avoid inappropriate cloning. */
4201 {
4202 /* For each constructor, we need two variants: an in-charge version
4203 and a not-in-charge version. */
4210 }
4211 else
4212 {
4215 /* For each destructor, we need three variants: an in-charge
4216 version, a not-in-charge version, and an in-charge deleting
4217 version. We clone the deleting version first because that
4218 means it will go second on the TYPE_METHODS list -- and that
4219 corresponds to the correct layout order in the virtual
4220 function table.
4222 For a non-virtual destructor, we do not build a deleting
4223 destructor. */
4225 {
4229 }
4236 }
4238 /* Note that this is an abstract function that is never emitted. */
4240 }
4242 /* DECL is an in charge constructor, which is being defined. This will
4243 have had an in class declaration, from whence clones were
4244 declared. An out-of-class definition can specify additional default
4245 arguments. As it is the clones that are involved in overload
4246 resolution, we must propagate the information from the DECL to its
4247 clones. */
4249 void
4251 {
4252 tree clone;
4256 {
4263 /* Skip the 'this' parameter. */
4279 {
4284 {
4285 /* A default parameter has been added. Adjust the
4286 clone's parameters. */
4290 tree type;
4295 {
4298 clone_parms);
4300 }
4303 clone_parms);
4312 }
4313 }
4315 }
4316 }
4318 /* For each of the constructors and destructors in T, create an
4319 in-charge and not-in-charge variant. */
4321 static void
4323 {
4324 tree fns;
4326 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4327 out now. */
4335 }
4337 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4338 of TYPE for virtual functions which FNDECL overrides. Return a
4339 mask of the tm attributes found therein. */
4341 static int
4343 {
4345 tree base_binfo;
4349 {
4359 else
4361 }
4364 }
4366 /* Subroutine of set_method_tm_attributes. Handle the checks and
4367 inheritance for one virtual method FNDECL. */
4369 static void
4371 {
4372 tree tm_attr;
4377 /* If FNDECL doesn't actually override anything (i.e. T is the
4378 class that first declares FNDECL virtual), then we're done. */
4385 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4386 tm_pure must match exactly, otherwise no weakening of
4387 tm_safe > tm_callable > nothing. */
4388 /* ??? The tm_pure attribute didn't make the transition to the
4389 multivendor language spec. */
4391 {
4393 {
4396 }
4397 }
4398 /* If the overridden function is tm_pure, then FNDECL must be. */
4401 /* Look for base class combinations that cannot be satisfied. */
4403 {
4409 }
4410 /* If FNDECL did not declare an attribute, then inherit the most
4411 restrictive one. */
4413 {
4415 }
4416 /* Otherwise validate that we're not weaker than a function
4417 that is being overridden. */
4418 else
4419 {
4423 }
4426 err_override:
4430 }
4432 /* For each of the methods in T, propagate a class-level tm attribute. */
4434 static void
4436 {
4439 /* Don't bother collecting tm attributes if transactional memory
4440 support is not enabled. */
4444 /* Process virtual methods first, as they inherit directly from the
4445 base virtual function and also require validation of new attributes. */
4447 {
4448 tree vchain;
4451 {
4456 }
4457 }
4459 /* If the class doesn't have an attribute, nothing more to do. */
4464 /* Any method that does not yet have a tm attribute inherits
4465 the one from the class. */
4467 {
4470 }
4471 }
4473 /* Returns true iff class T has a user-defined constructor other than
4474 the default constructor. */
4476 bool
4478 {
4479 tree fns;
4485 {
4492 }
4495 }
4497 /* Returns the defaulted constructor if T has one. Otherwise, returns
4498 NULL_TREE. */
4500 tree
4502 {
4509 {
4513 {
4519 }
4520 }
4523 }
4525 /* Returns true iff FN is a user-provided function, i.e. user-declared
4526 and not defaulted at its first declaration; or explicit, private,
4527 protected, or non-const. */
4529 bool
4531 {
4534 else
4537 }
4539 /* Returns true iff class T has a user-provided constructor. */
4541 bool
4543 {
4544 tree fns;
4552 /* This can happen in error cases; avoid crashing. */
4561 }
4563 /* Returns true iff class T has a user-provided default constructor. */
4565 bool
4567 {
4568 tree fns;
4574 {
4580 }
4583 }
4585 /* If default-initialization leaves part of TYPE uninitialized, returns
4586 a DECL for the field or TYPE itself (DR 253). */
4588 tree
4590 {
4601 {
4605 }
4610 {
4614 }
4617 }
4619 /* Returns true iff for class T, a trivial synthesized default constructor
4620 would be constexpr. */
4622 bool
4624 {
4625 /* A defaulted trivial default constructor is constexpr
4626 if there is nothing to initialize. */
4629 }
4631 /* Returns true iff class T has a constexpr default constructor. */
4633 bool
4635 {
4636 tree fns;
4639 {
4640 /* The caller should have stripped an enclosing array. */
4643 }
4645 {
4648 /* Non-trivial, we need to check subobject constructors. */
4650 }
4653 }
4655 /* Returns true iff class TYPE has a virtual destructor. */
4657 bool
4659 {
4660 tree dtor;
4668 }
4670 /* Returns true iff class T has a move constructor. */
4672 bool
4674 {
4675 tree fns;
4678 {
4681 }
4691 }
4693 /* Returns true iff class T has a move assignment operator. */
4695 bool
4697 {
4698 tree fns;
4701 {
4704 }
4712 }
4714 /* Returns true iff class T has a move constructor that was explicitly
4715 declared in the class body. Note that this is different from
4716 "user-provided", which doesn't include functions that are defaulted in
4717 the class. */
4719 bool
4721 {
4722 tree fns;
4731 {
4735 }
4738 }
4740 /* Returns true iff class T has a move assignment operator that was
4741 explicitly declared in the class body. */
4743 bool
4745 {
4746 tree fns;
4753 {
4757 }
4760 }
4762 /* Nonzero if we need to build up a constructor call when initializing an
4763 object of this class, either because it has a user-provided constructor
4764 or because it doesn't have a default constructor (so we need to give an
4765 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
4766 what you care about is whether or not an object can be produced by a
4767 constructor (e.g. so we don't set TREE_READONLY on const variables of
4768 such type); use this function when what you care about is whether or not
4769 to try to call a constructor to create an object. The latter case is
4770 the former plus some cases of constructors that cannot be called. */
4772 bool
4774 {
4775 tree inner;
4781 }
4783 /* Remove all zero-width bit-fields from T. */
4785 static void
4787 {
4792 {
4795 /* We should not be confused by the fact that grokbitfield
4796 temporarily sets the width of the bit field into
4797 DECL_INITIAL (*fieldsp).
4798 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
4799 to that width. */
4802 else
4804 }
4805 }
4807 /* Returns TRUE iff we need a cookie when dynamically allocating an
4808 array whose elements have the indicated class TYPE. */
4810 static bool
4812 {
4813 tree fns;
4818 /* If there's a non-trivial destructor, we need a cookie. In order
4819 to iterate through the array calling the destructor for each
4820 element, we'll have to know how many elements there are. */
4824 /* If the usual deallocation function is a two-argument whose second
4825 argument is of type `size_t', then we have to pass the size of
4826 the array to the deallocation function, so we will need to store
4827 a cookie. */
4831 /* If there are no `operator []' members, or the lookup is
4832 ambiguous, then we don't need a cookie. */
4835 /* Loop through all of the functions. */
4837 {
4838 tree fn;
4839 tree second_parm;
4841 /* Select the current function. */
4843 /* See if this function is a one-argument delete function. If
4844 it is, then it will be the usual deallocation function. */
4848 /* Do not consider this function if its second argument is an
4849 ellipsis. */
4852 /* Otherwise, if we have a two-argument function and the second
4853 argument is `size_t', it will be the usual deallocation
4854 function -- unless there is one-argument function, too. */
4858 }
4861 }
4863 /* Finish computing the `literal type' property of class type T.
4865 At this point, we have already processed base classes and
4866 non-static data members. We need to check whether the copy
4867 constructor is trivial, the destructor is trivial, and there
4868 is a trivial default constructor or at least one constexpr
4869 constructor other than the copy constructor. */
4871 static void
4873 {
4874 tree fn;
4890 {
4893 {
4897 }
4898 }
4899 }
4901 /* T is a non-literal type used in a context which requires a constant
4902 expression. Explain why it isn't literal. */
4904 void
4906 {
4916 /* Already explained. */
4925 {
4927 "default constructor, and has no constexpr constructor that "
4931 {
4932 /* Note that we can't simply call locate_ctor because when the
4933 constructor is deleted it just returns NULL_TREE. */
4934 tree fns;
4936 {
4943 {
4946 else
4949 }
4950 }
4951 }
4952 }
4953 else
4954 {
4958 {
4961 {
4966 }
4967 }
4969 {
4970 tree ftype;
4975 {
4980 }
4981 }
4982 }
4983 }
4985 /* Check the validity of the bases and members declared in T. Add any
4986 implicitly-generated functions (like copy-constructors and
4987 assignment operators). Compute various flag bits (like
4988 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
4989 level: i.e., independently of the ABI in use. */
4991 static void
4993 {
4994 /* Nonzero if the implicitly generated copy constructor should take
4995 a non-const reference argument. */
4997 /* Nonzero if the implicitly generated assignment operator
4998 should take a non-const reference argument. */
5000 tree access_decls;
5003 tree fn;
5005 /* By default, we use const reference arguments and generate default
5006 constructors. */
5010 /* Check all the base-classes. */
5014 /* Check all the method declarations. */
5017 /* Save the initial values of these flags which only indicate whether
5018 or not the class has user-provided functions. As we analyze the
5019 bases and members we can set these flags for other reasons. */
5023 /* Check all the data member declarations. We cannot call
5024 check_field_decls until we have called check_bases check_methods,
5025 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5026 being set appropriately. */
5031 /* A nearly-empty class has to be vptr-containing; a nearly empty
5032 class contains just a vptr. */
5036 /* Do some bookkeeping that will guide the generation of implicitly
5037 declared member functions. */
5040 /* We need to call a constructor for this class if it has a
5041 user-provided constructor, or if the default constructor is going
5042 to initialize the vptr. (This is not an if-and-only-if;
5043 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5044 themselves need constructing.) */
5047 /* [dcl.init.aggr]
5049 An aggregate is an array or a class with no user-provided
5050 constructors ... and no virtual functions.
5052 Again, other conditions for being an aggregate are checked
5053 elsewhere. */
5056 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5057 retain the old definition internally for ABI reasons. */
5066 /* If the class has no user-declared constructor, but does have
5067 non-static const or reference data members that can never be
5068 initialized, issue a warning. */
5070 /* Classes with user-declared constructors are presumed to
5071 initialize these members. */
5073 /* Aggregates can be initialized with brace-enclosed
5074 initializers. */
5076 {
5077 tree field;
5080 {
5081 tree type;
5096 }
5097 }
5099 /* Synthesize any needed methods. */
5101 cant_have_const_ctor,
5102 no_const_asn_ref);
5104 /* Check defaulted declarations here so we have cant_have_const_ctor
5105 and don't need to worry about clones. */
5108 {
5111 {
5112 bool imp_const_p
5118 /* If the function is defaulted outside the class, we just
5119 give the synthesis error. */
5125 }
5127 }
5130 {
5131 /* "The closure type associated with a lambda-expression has a deleted
5132 default constructor and a deleted copy assignment operator." */
5138 /* "This class type is not an aggregate." */
5140 }
5142 /* Compute the 'literal type' property before we
5143 do anything with non-static member functions. */
5146 /* Create the in-charge and not-in-charge variants of constructors
5147 and destructors. */
5150 /* Process the using-declarations. */
5154 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5157 /* Figure out whether or not we will need a cookie when dynamically
5158 allocating an array of this type. */
5161 }
5163 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5164 accordingly. If a new vfield was created (because T doesn't have a
5165 primary base class), then the newly created field is returned. It
5166 is not added to the TYPE_FIELDS list; it is the caller's
5167 responsibility to do that. Accumulate declared virtual functions
5168 on VIRTUALS_P. */
5170 static tree
5172 {
5173 tree fn;
5175 /* Collect the virtual functions declared in T. */
5179 {
5188 }
5190 /* If we couldn't find an appropriate base class, create a new field
5191 here. Even if there weren't any new virtual functions, we might need a
5192 new virtual function table if we're supposed to include vptrs in
5193 all classes that need them. */
5195 {
5196 /* We build this decl with vtbl_ptr_type_node, which is a
5197 `vtable_entry_type*'. It might seem more precise to use
5198 `vtable_entry_type (*)[N]' where N is the number of virtual
5199 functions. However, that would require the vtable pointer in
5200 base classes to have a different type than the vtable pointer
5201 in derived classes. We could make that happen, but that
5202 still wouldn't solve all the problems. In particular, the
5203 type-based alias analysis code would decide that assignments
5204 to the base class vtable pointer can't alias assignments to
5205 the derived class vtable pointer, since they have different
5206 types. Thus, in a derived class destructor, where the base
5207 class constructor was inlined, we could generate bad code for
5208 setting up the vtable pointer.
5210 Therefore, we use one type for all vtable pointers. We still
5211 use a type-correct type; it's just doesn't indicate the array
5212 bounds. That's better than using `void*' or some such; it's
5213 cleaner, and it let's the alias analysis code know that these
5214 stores cannot alias stores to void*! */
5215 tree field;
5228 /* This class is non-empty. */
5232 }
5235 }
5237 /* Add OFFSET to all base types of BINFO which is a base in the
5238 hierarchy dominated by T.
5240 OFFSET, which is a type offset, is number of bytes. */
5242 static void
5244 {
5246 tree primary_binfo;
5247 tree base_binfo;
5249 /* Update BINFO's offset. */
5254 offset));
5256 /* Find the primary base class. */
5262 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5263 downwards. */
5265 {
5266 /* Don't do the primary base twice. */
5274 }
5275 }
5277 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5278 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5279 empty subobjects of T. */
5281 static void
5283 {
5284 tree vbase;
5293 {
5294 /* In G++ 3.2, we incorrectly rounded the size before laying out
5295 the virtual bases. */
5297 #ifdef STRUCTURE_SIZE_BOUNDARY
5298 /* Packed structures don't need to have minimum size. */
5301 #endif
5305 }
5307 /* Find the last field. The artificial fields created for virtual
5308 bases will go after the last extant field to date. */
5313 /* Go through the virtual bases, allocating space for each virtual
5314 base that is not already a primary base class. These are
5315 allocated in inheritance graph order. */
5317 {
5322 {
5325 /* This virtual base is not a primary base of any class in the
5326 hierarchy, so we have to add space for it. */
5330 /* If the first virtual base might have been placed at a
5331 lower address, had we started from CLASSTYPE_SIZE, rather
5332 than TYPE_SIZE, issue a warning. There can be both false
5333 positives and false negatives from this warning in rare
5334 cases; to deal with all the possibilities would probably
5335 require performing both layout algorithms and comparing
5336 the results which is not particularly tractable. */
5338 && first_vbase
5339 && (tree_int_cst_lt
5344 bitsize_unit_node),
5347 "offset of virtual base %qT is not ABI-compliant and "
5349 basetype);
5352 }
5353 }
5354 }
5356 /* Returns the offset of the byte just past the end of the base class
5357 BINFO. */
5359 static tree
5361 {
5362 tree size;
5367 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5368 allocate some space for it. It cannot have virtual bases, so
5369 TYPE_SIZE_UNIT is fine. */
5371 else
5375 }
5377 /* Returns the offset of the byte just past the end of the base class
5378 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5379 only non-virtual bases are included. */
5381 static tree
5383 {
5386 tree binfo;
5387 tree base_binfo;
5388 tree offset;
5393 {
5403 }
5405 /* G++ 3.2 did not check indirect virtual bases. */
5409 {
5413 }
5416 }
5418 /* Warn about bases of T that are inaccessible because they are
5419 ambiguous. For example:
5421 struct S {};
5422 struct T : public S {};
5423 struct U : public S, public T {};
5425 Here, `(S*) new U' is not allowed because there are two `S'
5426 subobjects of U. */
5428 static void
5430 {
5433 tree basetype;
5434 tree binfo;
5435 tree base_binfo;
5437 /* If there are no repeated bases, nothing can be ambiguous. */
5441 /* Check direct bases. */
5444 {
5450 }
5452 /* Check for ambiguous virtual bases. */
5456 {
5462 }
5463 }
5465 /* Compare two INTEGER_CSTs K1 and K2. */
5467 static int
5469 {
5471 }
5473 /* Increase the size indicated in RLI to account for empty classes
5474 that are "off the end" of the class. */
5476 static void
5478 {
5479 tree eoc;
5480 tree rli_size;
5482 /* It might be the case that we grew the class to allocate a
5483 zero-sized base class. That won't be reflected in RLI, yet,
5484 because we are willing to overlay multiple bases at the same
5485 offset. However, now we need to make sure that RLI is big enough
5486 to reflect the entire class. */
5492 {
5494 /* In version 1 of the ABI, the size of a class that ends with
5495 a bitfield was not rounded up to a whole multiple of a
5496 byte. Because rli_size_unit_so_far returns only the number
5497 of fully allocated bytes, any extra bits were not included
5498 in the size. */
5500 else
5501 /* The size should have been rounded to a whole byte. */
5504 rli->bitpos
5513 }
5514 }
5516 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5517 BINFO_OFFSETs for all of the base-classes. Position the vtable
5518 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5520 static void
5522 {
5523 tree non_static_data_members;
5524 tree field;
5525 tree vptr;
5526 record_layout_info rli;
5527 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5528 types that appear at that offset. */
5529 splay_tree empty_base_offsets;
5530 /* True if the last field layed out was a bit-field. */
5532 /* The location at which the next field should be inserted. */
5534 /* T, as a base class. */
5535 tree base_t;
5537 /* Keep track of the first non-static data member. */
5540 /* Start laying out the record. */
5543 /* Mark all the primary bases in the hierarchy. */
5546 /* Create a pointer to our virtual function table. */
5549 /* The vptr is always the first thing in the class. */
5551 {
5556 }
5557 else
5560 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5565 /* Layout the non-static data members. */
5567 {
5568 tree type;
5569 tree padding;
5571 /* We still pass things that aren't non-static data members to
5572 the back end, in case it wants to do something with them. */
5574 {
5576 /* If the static data member has incomplete type, keep track
5577 of it so that it can be completed later. (The handling
5578 of pending statics in finish_record_layout is
5579 insufficient; consider:
5581 struct S1;
5582 struct S2 { static S1 s1; };
5584 At this point, finish_record_layout will be called, but
5585 S1 is still incomplete.) */
5587 {
5589 /* The visibility of static data members is determined
5590 at their point of declaration, not their point of
5591 definition. */
5593 }
5595 }
5603 /* If this field is a bit-field whose width is greater than its
5604 type, then there are some special rules for allocating
5605 it. */
5608 {
5610 tree integer_type;
5612 /* We must allocate the bits as if suitably aligned for the
5613 longest integer type that fits in this many bits. type
5614 of the field. Then, we are supposed to use the left over
5615 bits as additional padding. */
5624 /* ITK now indicates a type that is too large for the
5625 field. We have to back up by one to find the largest
5626 type that fits. */
5627 do
5628 {
5633 /* Figure out how much additional padding is required. GCC
5634 3.2 always created a padding field, even if it had zero
5635 width. */
5638 {
5640 /* In a union, the padding field must have the full width
5641 of the bit-field; all fields start at offset zero. */
5643 else
5644 {
5647 "ABI-compliant and may change in a future "
5649 t);
5652 }
5653 }
5654 #ifdef PCC_BITFIELD_TYPE_MATTERS
5655 /* An unnamed bitfield does not normally affect the
5656 alignment of the containing class on a target where
5657 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5658 make any exceptions for unnamed bitfields when the
5659 bitfields are longer than their types. Therefore, we
5660 temporarily give the field a name. */
5662 {
5665 }
5666 #endif
5671 empty_base_offsets);
5674 /* Now that layout has been performed, set the size of the
5675 field to the size of its declared type; the rest of the
5676 field is effectively invisible. */
5678 /* We must also reset the DECL_MODE of the field. */
5683 /* Versions of G++ before G++ 3.4 did not reset the
5684 DECL_MODE. */
5686 "the offset of %qD may not be ABI-compliant and may "
5688 }
5689 else
5691 empty_base_offsets);
5693 /* Remember the location of any empty classes in FIELD. */
5697 empty_base_offsets,
5700 /* If a bit-field does not immediately follow another bit-field,
5701 and yet it starts in the middle of a byte, we have failed to
5702 comply with the ABI. */
5705 /* The TREE_NO_WARNING flag gets set by Objective-C when
5706 laying out an Objective-C class. The ObjC ABI differs
5707 from the C++ ABI, and so we do not want a warning
5708 here. */
5710 && !last_field_was_bitfield
5713 bitsize_unit_node)))
5717 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5718 offset of the field. */
5725 "classes to be placed at different locations in a "
5728 /* The middle end uses the type of expressions to determine the
5729 possible range of expression values. In order to optimize
5730 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5731 must be made aware of the width of "i", via its type.
5733 Because C++ does not have integer types of arbitrary width,
5734 we must (for the purposes of the front end) convert from the
5735 type assigned here to the declared type of the bitfield
5736 whenever a bitfield expression is used as an rvalue.
5737 Similarly, when assigning a value to a bitfield, the value
5738 must be converted to the type given the bitfield here. */
5740 {
5745 {
5752 }
5753 }
5755 /* If we needed additional padding after this field, add it
5756 now. */
5758 {
5759 tree padding_field;
5762 FIELD_DECL,
5763 NULL_TREE,
5764 char_type_node);
5771 NULL_TREE,
5772 empty_base_offsets);
5773 }
5776 }
5779 {
5780 /* Make sure that we are on a byte boundary so that the size of
5781 the class without virtual bases will always be a round number
5782 of bytes. */
5785 }
5787 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5788 padding. */
5792 /* Delete all zero-width bit-fields from the list of fields. Now
5793 that the type is laid out they are no longer important. */
5796 /* Create the version of T used for virtual bases. We do not use
5797 make_class_type for this version; this is an artificial type. For
5798 a POD type, we just reuse T. */
5800 {
5803 /* Set the size and alignment for the new type. In G++ 3.2, all
5804 empty classes were considered to have size zero when used as
5805 base classes. */
5807 {
5812 "layout of classes derived from empty class %qT "
5814 t);
5815 }
5816 else
5817 {
5818 tree eoc;
5820 /* If the ABI version is not at least two, and the last
5821 field was a bit-field, RLI may not be on a byte
5822 boundary. In particular, rli_size_unit_so_far might
5823 indicate the last complete byte, while rli_size_so_far
5824 indicates the total number of bits used. Therefore,
5825 rli_size_so_far, rather than rli_size_unit_so_far, is
5826 used to compute TYPE_SIZE_UNIT. */
5834 eoc);
5841 }
5845 /* Copy the fields from T. */
5849 {
5851 FIELD_DECL,
5861 }
5863 /* Record the base version of the type. */
5866 }
5867 else
5870 /* Every empty class contains an empty class. */
5874 /* Set the TYPE_DECL for this type to contain the right
5875 value for DECL_OFFSET, so that we can use it as part
5876 of a COMPONENT_REF for multiple inheritance. */
5879 /* Now fix up any virtual base class types that we left lying
5880 around. We must get these done before we try to lay out the
5881 virtual function table. As a side-effect, this will remove the
5882 base subobject fields. */
5885 /* Make sure that empty classes are reflected in RLI at this
5886 point. */
5889 /* Make sure not to create any structures with zero size. */
5895 /* If this is a non-POD, declaring it packed makes a difference to how it
5896 can be used as a field; don't let finalize_record_size undo it. */
5900 /* Let the back end lay out the type. */
5903 /* Warn about bases that can't be talked about due to ambiguity. */
5906 /* Now that we're done with layout, give the base fields the real types. */
5911 /* Clean up. */
5918 }
5920 /* Determine the "key method" for the class type indicated by TYPE,
5921 and set CLASSTYPE_KEY_METHOD accordingly. */
5923 void
5925 {
5926 tree method;
5929 || processing_template_decl
5934 /* The key method is the first non-pure virtual function that is not
5935 inline at the point of class definition. On some targets the
5936 key function may not be inline; those targets should not call
5937 this function until the end of the translation unit. */
5943 {
5946 }
5949 }
5952 /* Allocate and return an instance of struct sorted_fields_type with
5953 N fields. */
5957 {
5964 }
5967 /* Perform processing required when the definition of T (a class type)
5968 is complete. */
5970 void
5972 {
5973 tree x;
5974 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5978 {
5983 }
5985 /* If this type was previously laid out as a forward reference,
5986 make sure we lay it out again. */
5990 /* Make assumptions about the class; we'll reset the flags if
5991 necessary. */
5997 /* Do end-of-class semantic processing: checking the validity of the
5998 bases and members and add implicitly generated methods. */
6001 /* Find the key method. */
6003 {
6004 /* The Itanium C++ ABI permits the key method to be chosen when
6005 the class is defined -- even though the key method so
6006 selected may later turn out to be an inline function. On
6007 some systems (such as ARM Symbian OS) the key method cannot
6008 be determined until the end of the translation unit. On such
6009 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6010 will cause the class to be added to KEYED_CLASSES. Then, in
6011 finish_file we will determine the key method. */
6015 /* If a polymorphic class has no key method, we may emit the vtable
6016 in every translation unit where the class definition appears. */
6019 }
6021 /* Layout the class itself. */
6024 /* We use the base type for trivial assignments, and hence it
6025 needs a mode. */
6030 /* If necessary, create the primary vtable for this class. */
6032 {
6033 /* We must enter these virtuals into the table. */
6037 /* Here we know enough to change the type of our virtual
6038 function table, but we will wait until later this function. */
6040 }
6043 {
6045 tree fn;
6052 /* Add entries for virtual functions introduced by this class. */
6056 /* Set DECL_VINDEX for all functions declared in this class. */
6058 fn;
6060 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6062 {
6066 /* A thunk. We should never be calling this entry directly
6067 from this vtable -- we'd use the entry for the non
6068 thunk base function. */
6072 }
6073 }
6078 /* Complete the rtl for any static member objects of the type we're
6079 working on. */
6086 /* Done with FIELDS...now decide whether to sort these for
6087 faster lookups later.
6089 We use a small number because most searches fail (succeeding
6090 ultimately as the search bores through the inheritance
6091 hierarchy), and we want this failure to occur quickly. */
6095 /* Complain if one of the field types requires lower visibility. */
6098 /* Make the rtl for any new vtables we have created, and unmark
6099 the base types we marked. */
6102 /* Build the VTT for T. */
6105 /* This warning does not make sense for Java classes, since they
6106 cannot have destructors. */
6108 {
6109 tree dtor;
6113 if it were virtual, we would have created it by now. */
6114 !dtor
6123 "%q#T has virtual functions and accessible"
6125 }
6132 /* Class layout, assignment of virtual table slots, etc., is now
6133 complete. Give the back end a chance to tweak the visibility of
6134 the class or perform any other required target modifications. */
6141 /* Finish debugging output for this type. */
6145 {
6148 {
6151 }
6153 {
6156 else
6157 {
6160 }
6162 }
6163 }
6164 }
6166 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6167 equal to THRESHOLD or greater than THRESHOLD. */
6169 static void
6171 {
6174 {
6179 }
6180 }
6182 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6184 void
6186 {
6189 {
6191 int n_fields
6202 }
6203 }
6205 /* When T was built up, the member declarations were added in reverse
6206 order. Rearrange them to declaration order. */
6208 void
6210 {
6211 tree next;
6212 tree prev;
6213 tree x;
6215 /* The following lists are all in reverse order. Put them in
6216 declaration order now. */
6220 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6221 reverse order, so we can't just use nreverse. */
6226 {
6230 }
6232 {
6236 }
6237 }
6239 tree
6241 {
6244 /* Now that we've got all the field declarations, reverse everything
6245 as necessary. */
6250 /* Nadger the current location so that diagnostics point to the start of
6251 the struct, not the end. */
6255 {
6256 tree x;
6262 /* We need to emit an error message if this type was used as a parameter
6263 and it is an abstract type, even if it is a template. We construct
6264 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6265 account and we call complete_vars with this type, which will check
6266 the PARM_DECLS. Note that while the type is being defined,
6267 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6268 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6274 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6275 an enclosing scope is a template class, so that this function be
6276 found by lookup_fnfields_1 when the using declaration is not
6277 instantiated yet. */
6280 {
6285 }
6287 /* Remember current #pragma pack value. */
6289 }
6290 else
6299 else
6306 }
6307 \f
6308 /* Return the dynamic type of INSTANCE, if known.
6309 Used to determine whether the virtual function table is needed
6310 or not.
6312 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6313 of our knowledge of its type. *NONNULL should be initialized
6314 before this function is called. */
6316 static tree
6318 {
6319 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6322 {
6326 else
6330 /* This is a call to a constructor, hence it's never zero. */
6332 {
6336 }
6340 /* This is a call to a constructor, hence it's never zero. */
6342 {
6346 }
6355 /* Propagate nonnull. */
6360 CASE_CONVERT:
6366 {
6367 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6368 with a real object -- given &p->f, p can still be null. */
6370 /* ??? Probably should check DECL_WEAK here. */
6373 }
6377 /* If this component is really a base class reference, then the field
6378 itself isn't definitive. */
6387 {
6391 }
6392 /* fall through... */
6397 {
6401 }
6403 {
6407 /* if we're in a ctor or dtor, we know our type. If
6408 current_class_ptr is set but we aren't in a function, we're in
6409 an NSDMI (and therefore a constructor). */
6414 {
6418 }
6419 }
6421 {
6422 /* We only need one hash table because it is always left empty. */
6426 htab_hash_pointer,
6427 htab_eq_pointer,
6430 /* Reference variables should be references to objects. */
6434 /* Enter the INSTANCE in a table to prevent recursion; a
6435 variable's initializer may refer to the variable
6436 itself. */
6441 {
6442 tree type;
6451 }
6452 }
6457 }
6458 #undef RECUR
6459 }
6461 /* Return nonzero if the dynamic type of INSTANCE is known, and
6462 equivalent to the static type. We also handle the case where
6463 INSTANCE is really a pointer. Return negative if this is a
6464 ctor/dtor. There the dynamic type is known, but this might not be
6465 the most derived base of the original object, and hence virtual
6466 bases may not be layed out according to this type.
6468 Used to determine whether the virtual function table is needed
6469 or not.
6471 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6472 of our knowledge of its type. *NONNULL should be initialized
6473 before this function is called. */
6475 int
6477 {
6480 tree fixed;
6482 /* processing_template_decl can be false in a template if we're in
6483 fold_non_dependent_expr, but we still want to suppress this check. */
6485 || (current_function_decl
6487 {
6488 /* In a template we only care about the type of the result. */
6492 }
6502 }
6504 \f
6505 void
6507 {
6510 current_class_stack
6518 }
6520 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6522 static void
6524 {
6525 tree type;
6527 /* We are re-entering the same class we just left, so we don't
6528 have to search the whole inheritance matrix to find all the
6529 decls to bind again. Instead, we install the cached
6530 class_shadowed list and walk through it binding names. */
6533 /* Restore IDENTIFIER_TYPE_VALUE. */
6535 type;
6538 }
6540 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6541 appropriate for TYPE.
6543 So that we may avoid calls to lookup_name, we cache the _TYPE
6544 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6546 For multiple inheritance, we perform a two-pass depth-first search
6547 of the type lattice. */
6549 void
6551 {
6552 class_stack_node_t csn;
6556 /* Make sure there is enough room for the new entry on the stack. */
6558 {
6560 current_class_stack
6562 current_class_stack_size);
6563 }
6565 /* Insert a new entry on the class stack. */
6572 current_class_depth++;
6574 /* Now set up the new type. */
6580 /* By default, things in classes are private, while things in
6581 structures or unions are public. */
6583 ? access_private_node
6589 {
6590 /* Forcibly remove any old class remnants. */
6592 }
6598 else
6600 }
6602 /* When we exit a toplevel class scope, we save its binding level so
6603 that we can restore it quickly. Here, we've entered some other
6604 class, so we must invalidate our cache. */
6606 void
6608 {
6610 }
6612 /* Get out of the current class scope. If we were in a class scope
6613 previously, that is the one popped to. */
6615 void
6617 {
6620 current_class_depth--;
6626 }
6628 /* Mark the top of the class stack as hidden. */
6630 void
6632 {
6635 }
6637 /* Mark the top of the class stack as un-hidden. */
6639 void
6641 {
6644 }
6646 /* Returns 1 if the class type currently being defined is either T or
6647 a nested type of T. */
6649 bool
6651 {
6659 /* We start looking from 1 because entry 0 is from global scope,
6660 and has no type. */
6662 {
6663 tree c;
6666 else
6667 {
6671 }
6676 }
6678 }
6680 /* If either current_class_type or one of its enclosing classes are derived
6681 from T, return the appropriate type. Used to determine how we found
6682 something via unqualified lookup. */
6684 tree
6686 {
6689 /* The bases of a dependent type are unknown. */
6700 {
6705 }
6708 }
6710 /* Returns the innermost class type which is not a lambda closure type. */
6712 tree
6714 {
6717 /* We start looking from 1 because entry 0 is from global scope,
6718 and has no type. */
6720 {
6721 tree c;
6724 else
6725 {
6729 }
6734 }
6736 }
6738 /* When entering a class scope, all enclosing class scopes' names with
6739 static meaning (static variables, static functions, types and
6740 enumerators) have to be visible. This recursive function calls
6741 pushclass for all enclosing class contexts until global or a local
6742 scope is reached. TYPE is the enclosed class. */
6744 void
6746 {
6747 /* A namespace might be passed in error cases, like A::B:C. */
6755 }
6757 /* Undoes a push_nested_class call. */
6759 void
6761 {
6767 }
6769 /* Returns the number of extern "LANG" blocks we are nested within. */
6771 int
6773 {
6775 }
6777 /* Set global variables CURRENT_LANG_NAME to appropriate value
6778 so that behavior of name-mangling machinery is correct. */
6780 void
6782 {
6786 {
6788 }
6790 {
6792 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
6793 (See record_builtin_java_type in decl.c.) However, that causes
6794 incorrect debug entries if these types are actually used.
6795 So we re-enable debug output after extern "Java". */
6804 }
6806 {
6808 }
6809 else
6811 }
6813 /* Get out of the current language scope. */
6815 void
6817 {
6819 }
6820 \f
6821 /* Type instantiation routines. */
6823 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
6824 matches the TARGET_TYPE. If there is no satisfactory match, return
6825 error_mark_node, and issue an error & warning messages under
6826 control of FLAGS. Permit pointers to member function if FLAGS
6827 permits. If TEMPLATE_ONLY, the name of the overloaded function was
6828 a template-id, and EXPLICIT_TARGS are the explicitly provided
6829 template arguments.
6831 If OVERLOAD is for one or more member functions, then ACCESS_PATH
6832 is the base path used to reference those member functions. If
6833 TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is
6834 resolved to a member function, access checks will be performed and
6835 errors issued if appropriate. */
6837 static tree
6839 tree overload,
6840 tsubst_flags_t flags,
6842 tree explicit_targs,
6843 tree access_path)
6844 {
6845 /* Here's what the standard says:
6847 [over.over]
6849 If the name is a function template, template argument deduction
6850 is done, and if the argument deduction succeeds, the deduced
6851 arguments are used to generate a single template function, which
6852 is added to the set of overloaded functions considered.
6854 Non-member functions and static member functions match targets of
6855 type "pointer-to-function" or "reference-to-function." Nonstatic
6856 member functions match targets of type "pointer-to-member
6857 function;" the function type of the pointer to member is used to
6858 select the member function from the set of overloaded member
6859 functions. If a nonstatic member function is selected, the
6860 reference to the overloaded function name is required to have the
6861 form of a pointer to member as described in 5.3.1.
6863 If more than one function is selected, any template functions in
6864 the set are eliminated if the set also contains a non-template
6865 function, and any given template function is eliminated if the
6866 set contains a second template function that is more specialized
6867 than the first according to the partial ordering rules 14.5.5.2.
6868 After such eliminations, if any, there shall remain exactly one
6869 selected function. */
6872 /* We store the matches in a TREE_LIST rooted here. The functions
6873 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
6874 interoperability with most_specialized_instantiation. */
6876 tree fn;
6877 tree target_fn_type;
6879 /* By the time we get here, we should be seeing only real
6880 pointer-to-member types, not the internal POINTER_TYPE to
6881 METHOD_TYPE representation. */
6887 /* Check that the TARGET_TYPE is reasonable. */
6891 /* This is OK, too. */
6894 /* This is OK, too. This comes from a conversion to reference
6895 type. */
6897 else
6898 {
6904 }
6906 /* Non-member functions and static member functions match targets of type
6907 "pointer-to-function" or "reference-to-function." Nonstatic member
6908 functions match targets of type "pointer-to-member-function;" the
6909 function type of the pointer to member is used to select the member
6910 function from the set of overloaded member functions.
6912 So figure out the FUNCTION_TYPE that we want to match against. */
6915 /* If we can find a non-template function that matches, we can just
6916 use it. There's no point in generating template instantiations
6917 if we're just going to throw them out anyhow. But, of course, we
6918 can only do this when we don't *need* a template function. */
6920 {
6921 tree fns;
6924 {
6928 /* We're not looking for templates just yet. */
6933 /* We're looking for a non-static member, and this isn't
6934 one, or vice versa. */
6937 /* Ignore functions which haven't been explicitly
6938 declared. */
6942 /* See if there's a match. */
6945 }
6946 }
6948 /* Now, if we've already got a match (or matches), there's no need
6949 to proceed to the template functions. But, if we don't have a
6950 match we need to look at them, too. */
6952 {
6953 tree target_arg_types;
6954 tree target_ret_type;
6955 tree fns;
6958 tree arg;
6972 {
6974 tree instantiation;
6975 tree targs;
6978 /* We're only looking for templates. */
6983 /* We're not looking for a non-static member, and this is
6984 one, or vice versa. */
6987 /* Try to do argument deduction. */
6992 /* Argument deduction failed. */
6995 /* Instantiate the template. */
6998 /* Instantiation failed. */
7001 /* See if there's a match. */
7004 }
7006 /* Now, remove all but the most specialized of the matches. */
7008 {
7013 NULL_TREE,
7014 NULL_TREE);
7015 }
7016 }
7018 /* Now we should have exactly one function in MATCHES. */
7020 {
7021 /* There were *no* matches. */
7023 {
7026 target_type);
7029 }
7031 }
7033 {
7034 /* There were too many matches. First check if they're all
7035 the same function. */
7036 tree match;
7044 {
7046 {
7049 target_type);
7051 /* Since print_candidates expects the functions in the
7052 TREE_VALUE slot, we flip them here. */
7057 }
7060 }
7061 }
7063 /* Good, exactly one match. Now, convert it to the correct type. */
7068 {
7076 {
7079 }
7080 }
7082 /* If we're doing overload resolution purely for the purpose of
7083 determining conversion sequences, we should not consider the
7084 function used. If this conversion sequence is selected, the
7085 function will be marked as used at this point. */
7087 {
7088 /* Make =delete work with SFINAE. */
7093 }
7095 /* We could not check access to member functions when this
7096 expression was originally created since we did not know at that
7097 time to which function the expression referred. */
7100 {
7103 }
7107 else
7108 {
7109 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7110 will mark the function as addressed, but here we must do it
7111 explicitly. */
7115 }
7116 }
7118 /* This function will instantiate the type of the expression given in
7119 RHS to match the type of LHSTYPE. If errors exist, then return
7120 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7121 we complain on errors. If we are not complaining, never modify rhs,
7122 as overload resolution wants to try many possible instantiations, in
7123 the hope that at least one will work.
7125 For non-recursive calls, LHSTYPE should be a function, pointer to
7126 function, or a pointer to member function. */
7128 tree
7130 {
7137 {
7141 }
7144 {
7150 /* Microsoft allows `A::f' to be resolved to a
7151 pointer-to-member. */
7152 ;
7153 else
7154 {
7159 }
7160 }
7163 {
7166 }
7168 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7169 deduce any type information. */
7171 {
7175 }
7177 /* There only a few kinds of expressions that may have a type
7178 dependent on overload resolution. */
7184 /* This should really only be used when attempting to distinguish
7185 what sort of a pointer to function we have. For now, any
7186 arithmetic operation which is not supported on pointers
7187 is rejected as an error. */
7190 {
7192 {
7198 /* Do not lose object's side effects. */
7202 }
7209 /* This can happen if we are forming a pointer-to-member for a
7210 member template. */
7213 /* Fall through. */
7216 {
7220 return
7224 }
7228 return
7232 access_path);
7235 {
7240 }
7247 }
7249 }
7250 \f
7251 /* Return the name of the virtual function pointer field
7252 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7253 this may have to look back through base types to find the
7254 ultimate field name. (For single inheritance, these could
7255 all be the same name. Who knows for multiple inheritance). */
7257 static tree
7259 {
7266 {
7272 }
7280 }
7282 void
7284 {
7285 #ifdef GATHER_STATISTICS
7289 {
7294 }
7295 #endif
7296 }
7298 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7299 according to [class]:
7300 The class-name is also inserted
7301 into the scope of the class itself. For purposes of access checking,
7302 the inserted class name is treated as if it were a public member name. */
7304 void
7306 {
7309 tree saved_cas;
7324 }
7326 /* Returns 1 if TYPE contains only padding bytes. */
7328 int
7330 {
7337 /* In G++ 3.2, whether or not a class was empty was determined by
7338 looking at its size. */
7341 else
7343 }
7345 /* Returns true if TYPE contains an empty class. */
7347 static bool
7349 {
7353 {
7354 tree field;
7355 tree binfo;
7356 tree base_binfo;
7368 }
7372 }
7374 /* Returns true if TYPE contains no actual data, just various
7375 possible combinations of empty classes and possibly a vptr. */
7377 bool
7379 {
7381 {
7382 tree field;
7383 tree binfo;
7384 tree base_binfo;
7387 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7388 out, but we'd like to be able to check this before then. */
7402 }
7406 }
7408 /* Note that NAME was looked up while the current class was being
7409 defined and that the result of that lookup was DECL. */
7411 void
7413 {
7414 splay_tree names_used;
7416 /* If we're not defining a class, there's nothing to do. */
7422 /* If there's already a binding for this NAME, then we don't have
7423 anything to worry about. */
7436 }
7438 /* Note that NAME was declared (as DECL) in the current class. Check
7439 to see that the declaration is valid. */
7441 void
7443 {
7444 splay_tree names_used;
7445 splay_tree_node n;
7447 /* Look to see if we ever used this name. */
7448 names_used
7452 /* The C language allows members to be declared with a type of the same
7453 name, and the C++ standard says this diagnostic is not required. So
7454 allow it in extern "C" blocks unless predantic is specified.
7455 Allow it in all cases if -ms-extensions is specified. */
7461 {
7462 /* [basic.scope.class]
7464 A name N used in a class S shall refer to the same declaration
7465 in its context and when re-evaluated in the completed scope of
7466 S. */
7470 }
7471 }
7473 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7474 Secondary vtables are merged with primary vtables; this function
7475 will return the VAR_DECL for the primary vtable. */
7477 tree
7479 {
7480 tree decl;
7484 {
7487 }
7491 }
7494 /* Returns the binfo for the primary base of BINFO. If the resulting
7495 BINFO is a virtual base, and it is inherited elsewhere in the
7496 hierarchy, then the returned binfo might not be the primary base of
7497 BINFO in the complete object. Check BINFO_PRIMARY_P or
7498 BINFO_LOST_PRIMARY_P to be sure. */
7500 static tree
7502 {
7503 tree primary_base;
7510 }
7512 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7514 static int
7516 {
7520 }
7522 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7523 INDENT should be zero when called from the top level; it is
7524 incremented recursively. IGO indicates the next expected BINFO in
7525 inheritance graph ordering. */
7527 static tree
7530 tree binfo,
7531 tree igo,
7533 {
7535 tree base_binfo;
7543 {
7546 }
7561 {
7565 TFF_PLAIN_IDENTIFIER),
7567 }
7569 {
7572 }
7577 {
7581 {
7585 TFF_PLAIN_IDENTIFIER));
7586 }
7588 {
7592 TFF_PLAIN_IDENTIFIER));
7593 }
7595 {
7599 TFF_PLAIN_IDENTIFIER));
7600 }
7602 {
7606 TFF_PLAIN_IDENTIFIER));
7607 }
7611 }
7617 }
7619 /* Dump the BINFO hierarchy for T. */
7621 static void
7623 {
7635 }
7637 /* Debug interface to hierarchy dumping. */
7639 void
7641 {
7643 }
7645 static void
7647 {
7652 {
7655 }
7656 }
7658 static void
7660 {
7661 tree value;
7663 HOST_WIDE_INT elt;
7671 TFF_PLAIN_IDENTIFIER));
7678 }
7680 static void
7682 {
7690 {
7697 {
7702 }
7706 }
7709 }
7711 static void
7713 {
7721 {
7726 }
7729 }
7731 /* Dump a function or thunk and its thunkees. */
7733 static void
7735 {
7738 tree thunks;
7746 {
7756 else
7762 }
7766 }
7768 /* Dump the thunks for FN. */
7770 void
7772 {
7774 }
7776 /* Virtual function table initialization. */
7778 /* Create all the necessary vtables for T and its base classes. */
7780 static void
7782 {
7783 tree vbase;
7787 /* We lay out the primary and secondary vtables in one contiguous
7788 vtable. The primary vtable is first, followed by the non-virtual
7789 secondary vtables in inheritance graph order. */
7793 /* Then come the virtual bases, also in inheritance graph order. */
7795 {
7799 }
7803 }
7805 /* Initialize the vtable for BINFO with the INITS. */
7807 static void
7809 {
7810 tree decl;
7816 }
7818 /* Build the VTT (virtual table table) for T.
7819 A class requires a VTT if it has virtual bases.
7821 This holds
7822 1 - primary virtual pointer for complete object T
7823 2 - secondary VTTs for each direct non-virtual base of T which requires a
7824 VTT
7825 3 - secondary virtual pointers for each direct or indirect base of T which
7826 has virtual bases or is reachable via a virtual path from T.
7827 4 - secondary VTTs for each direct or indirect virtual base of T.
7829 Secondary VTTs look like complete object VTTs without part 4. */
7831 static void
7833 {
7834 tree type;
7835 tree vtt;
7836 tree index;
7839 /* Build up the initializers for the VTT. */
7844 /* If we didn't need a VTT, we're done. */
7848 /* Figure out the type of the VTT. */
7852 /* Now, build the VTT object itself. */
7855 /* Add the VTT to the vtables list. */
7860 }
7862 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7863 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7864 and CHAIN the vtable pointer for this binfo after construction is
7865 complete. VALUE can also be another BINFO, in which case we recurse. */
7867 static tree
7869 {
7870 tree vt;
7873 {
7879 else
7881 }
7884 }
7886 /* Data for secondary VTT initialization. */
7888 {
7889 /* Is this the primary VTT? */
7892 /* Current index into the VTT. */
7893 tree index;
7895 /* Vector of initializers built up. */
7898 /* The type being constructed by this secondary VTT. */
7899 tree type_being_constructed;
7902 /* Recursively build the VTT-initializer for BINFO (which is in the
7903 hierarchy dominated by T). INITS points to the end of the initializer
7904 list to date. INDEX is the VTT index where the next element will be
7905 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7906 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7907 for virtual bases of T. When it is not so, we build the constructor
7908 vtables for the BINFO-in-T variant. */
7910 static void
7912 {
7914 tree b;
7915 tree init;
7916 secondary_vptr_vtt_init_data data;
7919 /* We only need VTTs for subobjects with virtual bases. */
7923 /* We need to use a construction vtable if this is not the primary
7924 VTT. */
7926 {
7929 /* Record the offset in the VTT where this sub-VTT can be found. */
7931 }
7933 /* Add the address of the primary vtable for the complete object. */
7937 {
7940 }
7943 /* Recursively add the secondary VTTs for non-virtual bases. */
7948 /* Add secondary virtual pointers for all subobjects of BINFO with
7949 either virtual bases or reachable along a virtual path, except
7950 subobjects that are non-virtual primary bases. */
7960 /* data.inits might have grown as we added secondary virtual pointers.
7961 Make sure our caller knows about the new vector. */
7965 /* Add the secondary VTTs for virtual bases in inheritance graph
7966 order. */
7968 {
7973 }
7974 else
7975 /* Remove the ctor vtables we created. */
7977 }
7979 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
7980 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
7982 static tree
7984 {
7987 /* We don't care about bases that don't have vtables. */
7991 /* We're only interested in proper subobjects of the type being
7992 constructed. */
7996 /* We're only interested in bases with virtual bases or reachable
7997 via a virtual path from the type being constructed. */
8002 /* We're not interested in non-virtual primary bases. */
8006 /* Record the index where this secondary vptr can be found. */
8008 {
8013 {
8014 /* It's a primary virtual base, and this is not a
8015 construction vtable. Find the base this is primary of in
8016 the inheritance graph, and use that base's vtable
8017 now. */
8020 }
8021 }
8023 /* Add the initializer for the secondary vptr itself. */
8026 /* Advance the vtt index. */
8031 }
8033 /* Called from build_vtt_inits via dfs_walk. After building
8034 constructor vtables and generating the sub-vtt from them, we need
8035 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8036 binfo of the base whose sub vtt was generated. */
8038 static tree
8040 {
8044 /* If this class has no vtable, none of its bases do. */
8048 /* This might be a primary base, so have no vtable in this
8049 hierarchy. */
8052 /* If we scribbled the construction vtable vptr into BINFO, clear it
8053 out now. */
8059 }
8061 /* Build the construction vtable group for BINFO which is in the
8062 hierarchy dominated by T. */
8064 static void
8066 {
8067 tree type;
8068 tree vtbl;
8069 tree id;
8070 tree vbase;
8073 /* See if we've already created this construction vtable group. */
8079 /* Build a version of VTBL (with the wrong type) for use in
8080 constructing the addresses of secondary vtables in the
8081 construction vtable group. */
8089 /* Add the vtables for each of our virtual bases using the vbase in T
8090 binfo. */
8092 vbase;
8094 {
8095 tree b;
8102 }
8104 /* Figure out the type of the construction vtable. */
8112 /* Initialize the construction vtable. */
8116 }
8118 /* Add the vtbl initializers for BINFO (and its bases other than
8119 non-virtual primaries) to the list of INITS. BINFO is in the
8120 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8121 the constructor the vtbl inits should be accumulated for. (If this
8122 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8123 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8124 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8125 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8126 but are not necessarily the same in terms of layout. */
8128 static void
8130 tree orig_binfo,
8131 tree rtti_binfo,
8132 tree vtbl,
8133 tree t,
8135 {
8137 tree base_binfo;
8142 /* If it doesn't have a vptr, we don't do anything. */
8146 /* If we're building a construction vtable, we're not interested in
8147 subobjects that don't require construction vtables. */
8153 /* Build the initializers for the BINFO-in-T vtable. */
8156 /* Walk the BINFO and its bases. We walk in preorder so that as we
8157 initialize each vtable we can figure out at what offset the
8158 secondary vtable lies from the primary vtable. We can't use
8159 dfs_walk here because we need to iterate through bases of BINFO
8160 and RTTI_BINFO simultaneously. */
8162 {
8163 /* Skip virtual bases. */
8169 inits);
8170 }
8171 }
8173 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8174 BINFO vtable to L. */
8176 static void
8178 tree orig_binfo,
8179 tree rtti_binfo,
8180 tree orig_vtbl,
8181 tree t,
8183 {
8190 {
8191 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8192 primary virtual base. If it is not the same primary in
8193 the hierarchy of T, we'll need to generate a ctor vtable
8194 for it, to place at its location in T. If it is the same
8195 primary, we still need a VTT entry for the vtable, but it
8196 should point to the ctor vtable for the base it is a
8197 primary for within the sub-hierarchy of RTTI_BINFO.
8199 There are three possible cases:
8201 1) We are in the same place.
8202 2) We are a primary base within a lost primary virtual base of
8203 RTTI_BINFO.
8204 3) We are primary to something not a base of RTTI_BINFO. */
8206 tree b;
8209 /* First, look through the bases we are primary to for RTTI_BINFO
8210 or a virtual base. */
8213 {
8218 }
8219 /* If we run out of primary links, keep looking down our
8220 inheritance chain; we might be an indirect primary. */
8224 found:
8226 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8227 base B and it is a base of RTTI_BINFO, this is case 2. In
8228 either case, we share our vtable with LAST, i.e. the
8229 derived-most base within B of which we are a primary. */
8232 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8233 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8234 binfo_ctor_vtable after everything's been set up. */
8237 /* Otherwise, this is case 3 and we get our own. */
8238 }
8245 {
8246 tree index;
8249 /* Add the initializer for this vtable. */
8253 /* Figure out the position to which the VPTR should point. */
8259 }
8262 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8263 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8264 straighten this out. */
8267 /* Throw away any unneeded intializers. */
8269 else
8270 /* For an ordinary vtable, set BINFO_VTABLE. */
8272 }
8276 /* Construct the initializer for BINFO's virtual function table. BINFO
8277 is part of the hierarchy dominated by T. If we're building a
8278 construction vtable, the ORIG_BINFO is the binfo we should use to
8279 find the actual function pointers to put in the vtable - but they
8280 can be overridden on the path to most-derived in the graph that
8281 ORIG_BINFO belongs. Otherwise,
8282 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8283 BINFO that should be indicated by the RTTI information in the
8284 vtable; it will be a base class of T, rather than T itself, if we
8285 are building a construction vtable.
8287 The value returned is a TREE_LIST suitable for wrapping in a
8288 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8289 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8290 number of non-function entries in the vtable.
8292 It might seem that this function should never be called with a
8293 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8294 base is always subsumed by a derived class vtable. However, when
8295 we are building construction vtables, we do build vtables for
8296 primary bases; we need these while the primary base is being
8297 constructed. */
8299 static void
8301 tree orig_binfo,
8302 tree t,
8303 tree rtti_binfo,
8306 {
8307 tree v;
8308 vtbl_init_data vid;
8310 tree vbinfo;
8314 /* Initialize VID. */
8322 /* The first vbase or vcall offset is at index -3 in the vtable. */
8325 /* Add entries to the vtable for RTTI. */
8328 /* Create an array for keeping track of the functions we've
8329 processed. When we see multiple functions with the same
8330 signature, we share the vcall offsets. */
8332 /* Add the vcall and vbase offset entries. */
8335 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8336 build_vbase_offset_vtbl_entries. */
8341 /* If the target requires padding between data entries, add that now. */
8343 {
8349 /* Move data entries into their new positions and add padding
8350 after the new positions. Iterate backwards so we don't
8351 overwrite entries that we would need to process later. */
8354 ix--)
8355 {
8363 {
8368 null_pointer_node);
8369 }
8370 }
8371 }
8376 /* The initializers for virtual functions were built up in reverse
8377 order. Straighten them out and add them to the running list in one
8378 step. */
8388 /* Go through all the ordinary virtual functions, building up
8389 initializers. */
8391 {
8392 tree delta;
8393 tree vcall_index;
8400 {
8404 {
8407 }
8409 }
8411 /* If the only definition of this function signature along our
8412 primary base chain is from a lost primary, this vtable slot will
8413 never be used, so just zero it out. This is important to avoid
8414 requiring extra thunks which cannot be generated with the function.
8416 We first check this in update_vtable_entry_for_fn, so we handle
8417 restored primary bases properly; we also need to do it here so we
8418 zero out unused slots in ctor vtables, rather than filling them
8419 with erroneous values (though harmless, apart from relocation
8420 costs). */
8425 {
8426 /* Pull the offset for `this', and the function to call, out of
8427 the list. */
8434 /* You can't call an abstract virtual function; it's abstract.
8435 So, we replace these functions with __pure_virtual. */
8437 {
8440 {
8442 abort_fndecl_addr
8446 }
8447 }
8448 /* Likewise for deleted virtuals. */
8450 {
8455 NULL_TREE);
8459 }
8460 else
8461 {
8463 {
8467 }
8468 /* Take the address of the function, considering it to be of an
8469 appropriate generic type. */
8473 }
8474 }
8476 /* And add it to the chain of initializers. */
8478 {
8483 else
8485 {
8491 }
8492 }
8493 else
8495 }
8496 }
8498 /* Adds to vid->inits the initializers for the vbase and vcall
8499 offsets in BINFO, which is in the hierarchy dominated by T. */
8501 static void
8503 {
8504 tree b;
8506 /* If this is a derived class, we must first create entries
8507 corresponding to the primary base class. */
8512 /* Add the vbase entries for this base. */
8514 /* Add the vcall entries for this base. */
8516 }
8518 /* Returns the initializers for the vbase offset entries in the vtable
8519 for BINFO (which is part of the class hierarchy dominated by T), in
8520 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8521 where the next vbase offset will go. */
8523 static void
8525 {
8526 tree vbase;
8527 tree t;
8528 tree non_primary_binfo;
8530 /* If there are no virtual baseclasses, then there is nothing to
8531 do. */
8537 /* We might be a primary base class. Go up the inheritance hierarchy
8538 until we find the most derived class of which we are a primary base:
8539 it is the offset of that which we need to use. */
8542 {
8543 tree b;
8545 /* If we have reached a virtual base, then it must be a primary
8546 base (possibly multi-level) of vid->binfo, or we wouldn't
8547 have called build_vcall_and_vbase_vtbl_entries for it. But it
8548 might be a lost primary, so just skip down to vid->binfo. */
8550 {
8553 }
8559 }
8561 /* Go through the virtual bases, adding the offsets. */
8563 vbase;
8565 {
8566 tree b;
8567 tree delta;
8572 /* Find the instance of this virtual base in the complete
8573 object. */
8576 /* If we've already got an offset for this virtual base, we
8577 don't need another one. */
8582 /* Figure out where we can find this vbase offset. */
8591 /* The vbase offset had better be the same. */
8594 /* The next vbase will come at a more negative offset. */
8598 /* The initializer is the delta from BINFO to this virtual base.
8599 The vbase offsets go in reverse inheritance-graph order, and
8600 we are walking in inheritance graph order so these end up in
8601 the right order. */
8608 }
8609 }
8611 /* Adds the initializers for the vcall offset entries in the vtable
8612 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8613 to VID->INITS. */
8615 static void
8617 {
8618 /* We only need these entries if this base is a virtual base. We
8619 compute the indices -- but do not add to the vtable -- when
8620 building the main vtable for a class. */
8623 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8624 correspond to VID->DERIVED), we are building a primary
8625 construction virtual table. Since this is a primary
8626 virtual table, we do not need the vcall offsets for
8627 BINFO. */
8629 {
8630 /* We need a vcall offset for each of the virtual functions in this
8631 vtable. For example:
8633 class A { virtual void f (); };
8634 class B1 : virtual public A { virtual void f (); };
8635 class B2 : virtual public A { virtual void f (); };
8636 class C: public B1, public B2 { virtual void f (); };
8638 A C object has a primary base of B1, which has a primary base of A. A
8639 C also has a secondary base of B2, which no longer has a primary base
8640 of A. So the B2-in-C construction vtable needs a secondary vtable for
8641 A, which will adjust the A* to a B2* to call f. We have no way of
8642 knowing what (or even whether) this offset will be when we define B2,
8643 so we store this "vcall offset" in the A sub-vtable and look it up in
8644 a "virtual thunk" for B2::f.
8646 We need entries for all the functions in our primary vtable and
8647 in our non-virtual bases' secondary vtables. */
8649 /* If we are just computing the vcall indices -- but do not need
8650 the actual entries -- not that. */
8653 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8655 }
8656 }
8658 /* Build vcall offsets, starting with those for BINFO. */
8660 static void
8662 {
8664 tree primary_binfo;
8665 tree base_binfo;
8667 /* Don't walk into virtual bases -- except, of course, for the
8668 virtual base for which we are building vcall offsets. Any
8669 primary virtual base will have already had its offsets generated
8670 through the recursion in build_vcall_and_vbase_vtbl_entries. */
8674 /* If BINFO has a primary base, process it first. */
8679 /* Add BINFO itself to the list. */
8682 /* Scan the non-primary bases of BINFO. */
8686 }
8688 /* Called from build_vcall_offset_vtbl_entries_r. */
8690 static void
8692 {
8693 /* Make entries for the rest of the virtuals. */
8695 {
8696 tree orig_fn;
8698 /* The ABI requires that the methods be processed in declaration
8699 order. G++ 3.2 used the order in the vtable. */
8701 orig_fn;
8705 }
8706 else
8707 {
8708 tree derived_virtuals;
8709 tree base_virtuals;
8710 tree orig_virtuals;
8711 /* If BINFO is a primary base, the most derived class which has
8712 BINFO as a primary base; otherwise, just BINFO. */
8713 tree non_primary_binfo;
8715 /* We might be a primary base class. Go up the inheritance hierarchy
8716 until we find the most derived class of which we are a primary base:
8717 it is the BINFO_VIRTUALS there that we need to consider. */
8720 {
8721 tree b;
8723 /* If we have reached a virtual base, then it must be vid->vbase,
8724 because we ignore other virtual bases in
8725 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
8726 base (possibly multi-level) of vid->binfo, or we wouldn't
8727 have called build_vcall_and_vbase_vtbl_entries for it. But it
8728 might be a lost primary, so just skip down to vid->binfo. */
8730 {
8734 }
8740 }
8743 /* For a ctor vtable we need the equivalent binfo within the hierarchy
8744 where rtti_binfo is the most derived type. */
8745 non_primary_binfo
8751 base_virtuals;
8755 {
8756 tree orig_fn;
8758 /* Find the declaration that originally caused this function to
8759 be present in BINFO_TYPE (binfo). */
8762 /* When processing BINFO, we only want to generate vcall slots for
8763 function slots introduced in BINFO. So don't try to generate
8764 one if the function isn't even defined in BINFO. */
8769 }
8770 }
8771 }
8773 /* Add a vcall offset entry for ORIG_FN to the vtable. */
8775 static void
8777 {
8779 tree vcall_offset;
8780 tree derived_entry;
8782 /* If there is already an entry for a function with the same
8783 signature as FN, then we do not need a second vcall offset.
8784 Check the list of functions already present in the derived
8785 class vtable. */
8787 {
8789 /* We only use one vcall offset for virtual destructors,
8790 even though there are two virtual table entries. */
8794 }
8796 /* If we are building these vcall offsets as part of building
8797 the vtable for the most derived class, remember the vcall
8798 offset. */
8800 {
8803 NULL);
8806 }
8808 /* The next vcall offset will be found at a more negative
8809 offset. */
8813 /* Keep track of this function. */
8817 {
8818 tree base;
8819 tree fn;
8821 /* Find the overriding function. */
8825 else
8826 {
8829 /* The vbase we're working on is a primary base of
8830 vid->binfo. But it might be a lost primary, so its
8831 BINFO_OFFSET might be wrong, so we just use the
8832 BINFO_OFFSET from vid->binfo. */
8838 vcall_offset);
8839 }
8840 /* Add the initializer to the vtable. */
8842 }
8843 }
8845 /* Return vtbl initializers for the RTTI entries corresponding to the
8846 BINFO's vtable. The RTTI entries should indicate the object given
8847 by VID->rtti_binfo. */
8849 static void
8851 {
8852 tree b;
8853 tree t;
8854 tree offset;
8855 tree decl;
8856 tree init;
8860 /* To find the complete object, we will first convert to our most
8861 primary base, and then add the offset in the vtbl to that value. */
8865 {
8866 tree primary_base;
8872 }
8876 /* The second entry is the address of the typeinfo object. */
8879 else
8882 /* Convert the declaration to a type that can be stored in the
8883 vtable. */
8887 /* Add the offset-to-top entry. It comes earlier in the vtable than
8888 the typeinfo entry. Convert the offset to look like a
8889 function pointer, so that we can put it in the vtable. */
8892 }