| blob | f5b9010c3a993a02d55ea27665e445a9ba144027 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2014 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* High-level class interface. */
44 /* The number of nested classes being processed. If we are not in the
45 scope of any class, this is zero. */
49 /* In order to deal with nested classes, we keep a stack of classes.
50 The topmost entry is the innermost class, and is the entry at index
51 CURRENT_CLASS_DEPTH */
54 /* The name of the class. */
55 tree name;
57 /* The _TYPE node for the class. */
58 tree type;
60 /* The access specifier pending for new declarations in the scope of
61 this class. */
62 tree access;
64 /* If were defining TYPE, the names used in this class. */
65 splay_tree names_used;
67 /* Nonzero if this class is no longer open, because of a call to
68 push_to_top_level. */
73 {
74 /* The base for which we're building initializers. */
75 tree binfo;
76 /* The type of the most-derived type. */
77 tree derived;
78 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
79 unless ctor_vtbl_p is true. */
80 tree rtti_binfo;
81 /* The negative-index vtable initializers built up so far. These
82 are in order from least negative index to most negative index. */
84 /* The binfo for the virtual base for which we're building
85 vcall offset initializers. */
86 tree vbase;
87 /* The functions in vbase for which we have already provided vcall
88 offsets. */
90 /* The vtable index of the next vcall or vbase offset. */
91 tree index;
92 /* Nonzero if we are building the initializer for the primary
93 vtable. */
95 /* Nonzero if we are building the initializer for a construction
96 vtable. */
98 /* True when adding vcall offset entries to the vtable. False when
99 merely computing the indices. */
103 /* The type of a function passed to walk_subobject_offsets. */
106 /* The stack itself. This is a dynamically resized array. The
107 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
111 /* The size of the largest empty class seen in this translation unit. */
114 /* An array of all local classes present in this translation unit, in
115 declaration order. */
197 tree *);
207 splay_tree_key k2);
216 /* Variables shared between class.c and call.c. */
226 /* Convert to or from a base subobject. EXPR is an expression of type
227 `A' or `A*', an expression of type `B' or `B*' is returned. To
228 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
229 the B base instance within A. To convert base A to derived B, CODE
230 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
231 In this latter case, A must not be a morally virtual base of B.
232 NONNULL is true if EXPR is known to be non-NULL (this is only
233 needed when EXPR is of pointer type). CV qualifiers are preserved
234 from EXPR. */
236 tree
238 tree expr,
239 tree binfo,
241 tsubst_flags_t complain)
242 {
245 tree probe;
246 tree offset;
247 tree target_type;
249 tree ptr_target_type;
259 {
265 }
273 {
274 /* This can happen when adjust_result_of_qualified_name_lookup can't
275 find a unique base binfo in a call to a member function. We
276 couldn't give the diagnostic then since we might have been calling
277 a static member function, so we do it now. */
279 {
283 }
285 }
292 /* Nothing to do. */
296 {
298 {
300 {
303 "pointer to derived class %qT because the base is "
305 else
309 }
310 else
311 {
317 else
321 }
322 }
324 }
327 /* This must happen before the call to save_expr. */
329 else
335 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
336 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
337 expression returned matches the input. */
338 target_type = cp_build_qualified_type
342 /* Do we need to look in the vtable for the real offset? */
345 /* Don't bother with the calculations inside sizeof; they'll ICE if the
346 source type is incomplete and the pointer value doesn't matter. In a
347 template (even in fold_non_dependent_expr), we don't have vtables set
348 up properly yet, and the value doesn't matter there either; we're just
349 interested in the result of overload resolution. */
352 {
357 }
359 /* If we're in an NSDMI, we don't have the full constructor context yet
360 that we need for converting to a virtual base, so just build a stub
361 CONVERT_EXPR and expand it later in bot_replace. */
364 {
370 }
372 /* Do we need to check for a null pointer? */
374 {
375 /* If we know the conversion will not actually change the value
376 of EXPR, then we can avoid testing the expression for NULL.
377 We have to avoid generating a COMPONENT_REF for a base class
378 field, because other parts of the compiler know that such
379 expressions are always non-NULL. */
383 }
385 /* Protect against multiple evaluation if necessary. */
389 /* Now that we've saved expr, build the real null test. */
391 {
395 }
397 /* If this is a simple base reference, express it as a COMPONENT_REF. */
399 /* We don't build base fields for empty bases, and they aren't very
400 interesting to the optimizers anyway. */
402 {
409 }
412 {
413 /* Going via virtual base V_BINFO. We need the static offset
414 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
415 V_BINFO. That offset is an entry in D_BINFO's vtable. */
416 tree v_offset;
419 {
420 /* In a base member initializer, we cannot rely on the
421 vtable being set up. We have to indirect via the
422 vtt_parm. */
423 tree t;
429 }
430 else
432 complain),
441 v_offset);
453 /* Negative fixed_type_p means this is a constructor or destructor;
454 virtual base layout is fixed in in-charge [cd]tors, but not in
455 base [cd]tors. */
459 v_offset,
462 else
464 }
472 {
477 }
478 else
484 out:
490 }
492 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
493 Perform a derived-to-base conversion by recursively building up a
494 sequence of COMPONENT_REFs to the appropriate base fields. */
496 static tree
498 {
501 tree field;
504 {
505 tree temp;
509 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
510 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
511 an lvalue in the front end; only _DECLs and _REFs are lvalues
512 in the back end. */
518 }
520 /* Recurse. */
525 /* Is this the base field created by build_base_field? */
529 /* If we're looking for a field in the most-derived class,
530 also check the field offset; we can have two base fields
531 of the same type if one is an indirect virtual base and one
532 is a direct non-virtual base. */
536 {
537 /* We don't use build_class_member_access_expr here, as that
538 has unnecessary checks, and more importantly results in
539 recursive calls to dfs_walk_once. */
547 /* Mark the expression const or volatile, as appropriate.
548 Even though we've dealt with the type above, we still have
549 to mark the expression itself. */
556 }
558 /* Didn't find the base field?!? */
560 }
562 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
563 type is a class type or a pointer to a class type. In the former
564 case, TYPE is also a class type; in the latter it is another
565 pointer type. If CHECK_ACCESS is true, an error message is emitted
566 if TYPE is inaccessible. If OBJECT has pointer type, the value is
567 assumed to be non-NULL. */
569 tree
571 tsubst_flags_t complain)
572 {
573 tree binfo;
574 tree object_type;
577 {
580 }
581 else
590 }
592 /* EXPR is an expression with unqualified class type. BASE is a base
593 binfo of that class type. Returns EXPR, converted to the BASE
594 type. This function assumes that EXPR is the most derived class;
595 therefore virtual bases can be found at their static offsets. */
597 tree
599 {
600 tree expr_type;
604 {
605 /* If this is a non-empty base, use a COMPONENT_REF. */
609 /* We use fold_build2 and fold_convert below to simplify the trees
610 provided to the optimizers. It is not safe to call these functions
611 when processing a template because they do not handle C++-specific
612 trees. */
620 }
623 }
625 \f
626 tree
628 {
632 /* Can happen in case of duplicate base types (c++/59082). */
636 /* First, convert to the requested type. */
641 /* Second, the requested type may not be the owner of its own vptr.
642 If not, convert to the base class that owns it. We cannot use
643 convert_to_base here, because VCONTEXT may appear more than once
644 in the inheritance hierarchy of TYPE, and thus direct conversion
645 between the types may be ambiguous. Following the path back up
646 one step at a time via primary bases avoids the problem. */
650 {
653 }
656 }
658 /* Given an object INSTANCE, return an expression which yields the
659 vtable element corresponding to INDEX. There are many special
660 cases for INSTANCE which we take care of here, mainly to avoid
661 creating extra tree nodes when we don't have to. */
663 static tree
665 {
666 tree aref;
669 /* Try to figure out what a reference refers to, and
670 access its virtual function table directly. */
678 {
683 }
692 }
694 tree
696 {
700 }
702 /* Given a stable object pointer INSTANCE_PTR, return an expression which
703 yields a function pointer corresponding to vtable element INDEX. */
705 tree
707 {
708 tree aref;
711 tf_warning_or_error),
712 idx);
714 /* When using function descriptors, the address of the
715 vtable entry is treated as a function pointer. */
720 /* Remember this as a method reference, for later devirtualization. */
724 }
726 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
727 for the given TYPE. */
729 static tree
731 {
733 }
735 /* DECL is an entity associated with TYPE, like a virtual table or an
736 implicitly generated constructor. Determine whether or not DECL
737 should have external or internal linkage at the object file
738 level. This routine does not deal with COMDAT linkage and other
739 similar complexities; it simply sets TREE_PUBLIC if it possible for
740 entities in other translation units to contain copies of DECL, in
741 the abstract. */
743 void
745 {
748 }
750 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
751 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
752 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
754 static tree
756 {
757 tree decl;
760 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
761 now to avoid confusion in mangle_decl. */
770 /* At one time the vtable info was grabbed 2 words at a time. This
771 fails on sparc unless you have 8-byte alignment. (tiemann) */
775 /* The vtable has not been defined -- yet. */
779 /* Mark the VAR_DECL node representing the vtable itself as a
780 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
781 is rather important that such things be ignored because any
782 effort to actually generate DWARF for them will run into
783 trouble when/if we encounter code like:
785 #pragma interface
786 struct S { virtual void member (); };
788 because the artificial declaration of the vtable itself (as
789 manufactured by the g++ front end) will say that the vtable is
790 a static member of `S' but only *after* the debug output for
791 the definition of `S' has already been output. This causes
792 grief because the DWARF entry for the definition of the vtable
793 will try to refer back to an earlier *declaration* of the
794 vtable as a static member of `S' and there won't be one. We
795 might be able to arrange to have the "vtable static member"
796 attached to the member list for `S' before the debug info for
797 `S' get written (which would solve the problem) but that would
798 require more intrusive changes to the g++ front end. */
802 }
804 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
805 or even complete. If this does not exist, create it. If COMPLETE is
806 nonzero, then complete the definition of it -- that will render it
807 impossible to actually build the vtable, but is useful to get at those
808 which are known to exist in the runtime. */
810 tree
812 {
813 tree decl;
822 {
825 }
828 }
830 /* Build the primary virtual function table for TYPE. If BINFO is
831 non-NULL, build the vtable starting with the initial approximation
832 that it is the same as the one which is the head of the association
833 list. Returns a nonzero value if a new vtable is actually
834 created. */
836 static int
838 {
839 tree decl;
840 tree virtuals;
845 {
847 /* We have already created a vtable for this base, so there's
848 no need to do it again. */
855 }
856 else
857 {
860 }
863 {
866 }
868 /* Initialize the association list for this type, based
869 on our first approximation. */
874 }
876 /* Give BINFO a new virtual function table which is initialized
877 with a skeleton-copy of its original initialization. The only
878 entry that changes is the `delta' entry, so we can really
879 share a lot of structure.
881 FOR_TYPE is the most derived type which caused this table to
882 be needed.
884 Returns nonzero if we haven't met BINFO before.
886 The order in which vtables are built (by calling this function) for
887 an object must remain the same, otherwise a binary incompatibility
888 can result. */
890 static int
892 {
894 /* We already created a vtable for this base. There's no need to
895 do it again. */
898 /* Remember that we've created a vtable for this BINFO, so that we
899 don't try to do so again. */
902 /* Make fresh virtual list, so we can smash it later. */
905 /* Secondary vtables are laid out as part of the same structure as
906 the primary vtable. */
909 }
911 /* Create a new vtable for BINFO which is the hierarchy dominated by
912 T. Return nonzero if we actually created a new vtable. */
914 static int
916 {
918 /* In this case, it is *type*'s vtable we are modifying. We start
919 with the approximation that its vtable is that of the
920 immediate base class. */
922 else
923 /* This is our very own copy of `basetype' to play with. Later,
924 we will fill in all the virtual functions that override the
925 virtual functions in these base classes which are not defined
926 by the current type. */
928 }
930 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
931 (which is in the hierarchy dominated by T) list FNDECL as its
932 BV_FN. DELTA is the required constant adjustment from the `this'
933 pointer where the vtable entry appears to the `this' required when
934 the function is actually called. */
936 static void
938 tree binfo,
939 tree fndecl,
940 tree delta,
942 {
943 tree v;
949 {
950 /* We need a new vtable for BINFO. */
952 {
953 /* If we really did make a new vtable, we also made a copy
954 of the BINFO_VIRTUALS list. Now, we have to find the
955 corresponding entry in that list. */
960 }
965 }
966 }
968 // Returns the template associated with the member FN or
969 // NULL if the declaration is neither a template nor temploid.
972 {
978 }
980 // Returns true if NEWDECL and OLDDECL are member functions with with
981 // different constraints. If NEWDECL and OLDDECL are non-template members
982 // or specializations of non-template members, the overloads are
983 // differentiated by the template constraints.
984 //
985 // Note that the types of the functions are assumed to be equivalent.
988 {
992 // If neither is a template or temploid, then they cannot
993 // be constrained declarations.
996 else
998 }
1000 \f
1001 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
1002 the USING_DECL naming METHOD. Returns true if the method could be
1003 added to the method vec. */
1005 bool
1007 {
1009 tree overload;
1015 tree current_fns;
1016 tree fns;
1029 {
1030 /* Make a new method vector. We start with 8 entries. We must
1031 allocate at least two (for constructors and destructors), and
1032 we're going to end up with an assignment operator at some
1033 point as well. */
1035 /* Create slots for constructors and destructors. */
1039 }
1041 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1044 /* Constructors and destructors go in special slots. */
1048 {
1052 {
1058 type);
1059 }
1060 }
1061 else
1062 {
1063 tree m;
1066 /* See if we already have an entry with this name. */
1070 {
1073 {
1078 }
1082 {
1085 }
1090 }
1091 }
1094 /* Check to see if we've already got this method. */
1096 {
1098 tree fn_type;
1099 tree method_type;
1100 tree parms1;
1101 tree parms2;
1106 /* [over.load] Member function declarations with the
1107 same name and the same parameter types cannot be
1108 overloaded if any of them is a static member
1109 function declaration.
1111 [over.load] Member function declarations with the same name and
1112 the same parameter-type-list as well as member function template
1113 declarations with the same name, the same parameter-type-list, and
1114 the same template parameter lists cannot be overloaded if any of
1115 them, but not all, have a ref-qualifier.
1117 [namespace.udecl] When a using-declaration brings names
1118 from a base class into a derived class scope, member
1119 functions in the derived class override and/or hide member
1120 functions with the same name and parameter types in a base
1121 class (rather than conflicting). */
1127 /* Compare the quals on the 'this' parm. Don't compare
1128 the whole types, as used functions are treated as
1129 coming from the using class in overload resolution. */
1132 /* Either both or neither need to be ref-qualified for
1133 differing quals to allow overloading. */
1140 /* For templates, the return type and template parameters
1141 must be identical. */
1158 {
1159 /* For function versions, their parms and types match
1160 but they are not duplicates. Record function versions
1161 as and when they are found. extern "C" functions are
1162 not treated as versions. */
1168 {
1169 /* Mark functions as versions if necessary. Modify the mangled
1170 decl name if necessary. */
1172 {
1176 }
1178 {
1182 }
1185 }
1187 {
1189 {
1196 }
1197 /* Otherwise defer to the other function. */
1199 }
1201 {
1203 /* Defer to the local function. */
1205 }
1208 else
1209 {
1212 }
1214 /* We don't call duplicate_decls here to merge the
1215 declarations because that will confuse things if the
1216 methods have inline definitions. In particular, we
1217 will crash while processing the definitions. */
1219 }
1220 }
1222 /* A class should never have more than one destructor. */
1226 /* Add the new binding. */
1228 {
1231 }
1232 else
1241 {
1244 /* We only expect to add few methods in the COMPLETE_P case, so
1245 just make room for one more method in that case. */
1248 else
1254 else
1256 }
1257 else
1258 /* Replace the current slot. */
1261 }
1263 /* Subroutines of finish_struct. */
1265 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1266 legit, otherwise return 0. */
1268 static int
1270 {
1271 tree elem;
1280 {
1282 {
1286 else
1289 }
1290 else
1291 {
1292 /* They're changing the access to the same thing they changed
1293 it to before. That's OK. */
1294 ;
1295 }
1296 }
1297 else
1298 {
1300 tf_warning_or_error);
1303 }
1305 }
1307 /* Process the USING_DECL, which is a member of T. */
1309 static void
1311 {
1314 tree access
1319 tree old_value;
1324 tf_warning_or_error);
1326 {
1332 else
1334 }
1342 ;
1344 {
1346 /* It's OK to use functions from a base when there are functions with
1348 else
1349 {
1354 }
1355 }
1357 {
1361 }
1363 /* Make type T see field decl FDECL with access ACCESS. */
1366 {
1369 }
1370 else
1372 }
1373 \f
1374 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1375 types with abi tags, add the corresponding identifiers to the VEC in
1376 *DATA and set IDENTIFIER_MARKED. */
1378 struct abi_tag_data
1379 {
1380 tree t;
1381 tree subob;
1382 // error_mark_node to get diagnostics; otherwise collect missing tags here
1383 tree tags;
1384 };
1386 static tree
1388 {
1392 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1393 anyway, but let's make sure of it. */
1397 {
1401 {
1405 {
1407 {
1408 /* We're collecting tags from template arguments. */
1414 /* Don't inherit this tag multiple times. */
1416 }
1418 /* Otherwise we're diagnosing missing tags. */
1420 {
1425 }
1426 else
1427 {
1434 }
1435 }
1436 }
1437 }
1439 }
1441 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1442 complete) template arguments. */
1444 static void
1446 {
1449 {
1452 {
1456 }
1457 }
1458 }
1460 /* Check that class T has all the abi tags that subobject SUBOB has, or
1461 warn if not. */
1463 static void
1465 {
1474 }
1476 void
1478 {
1487 {
1490 {
1494 }
1495 }
1497 // If we found some tags on our template arguments, add them to our
1498 // abi_tag attribute.
1500 {
1504 else
1508 }
1511 }
1513 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1514 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1515 properties of the bases. */
1517 static void
1521 {
1525 tree base_binfo;
1526 tree binfo;
1536 {
1545 /* If any base class is non-literal, so is the derived class. */
1549 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1550 here because the case of virtual functions but non-virtual
1551 dtor is handled in finish_struct_1. */
1556 /* If the base class doesn't have copy constructors or
1557 assignment operators that take const references, then the
1558 derived class cannot have such a member automatically
1559 generated. */
1568 /* A virtual base does not effect nearly emptiness. */
1569 ;
1571 {
1573 /* And if there is more than one nearly empty base, then the
1574 derived class is not nearly empty either. */
1576 else
1577 /* Remember we've seen one. */
1579 }
1581 /* If the base class is not empty or nearly empty, then this
1582 class cannot be nearly empty. */
1585 /* A lot of properties from the bases also apply to the derived
1586 class. */
1603 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1606 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1610 /* A standard-layout class is a class that:
1611 ...
1612 * has no non-standard-layout base classes, */
1615 {
1616 tree basefield;
1617 /* ...has no base classes of the same type as the first non-static
1618 data member... */
1620 && (same_type_ignoring_top_level_qualifiers_p
1623 else
1624 /* ...either has no non-static data members in the most-derived
1625 class and at most one base class with non-static data
1626 members, or has no base classes with non-static data
1627 members */
1631 {
1634 else
1637 }
1638 }
1640 /* Don't bother collecting tm attributes if transactional memory
1641 support is not enabled. */
1643 {
1647 }
1650 }
1652 /* If one of the base classes had TM attributes, and the current class
1653 doesn't define its own, then the current class inherits one. */
1655 {
1658 }
1659 }
1661 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1662 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1663 that have had a nearly-empty virtual primary base stolen by some
1664 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1665 T. */
1667 static void
1669 {
1673 tree base_binfo;
1675 /* Determine the primary bases of our bases. */
1678 {
1681 /* See if we're the non-virtual primary of our inheritance
1682 chain. */
1684 {
1691 /* We are the primary binfo. */
1693 }
1694 /* Determine if we have a virtual primary base, and mark it so.
1695 */
1697 {
1701 /* Someone already claimed this base. */
1703 else
1704 {
1705 tree delta;
1710 /* A virtual binfo might have been copied from within
1711 another hierarchy. As we're about to use it as a
1712 primary base, make sure the offsets match. */
1720 }
1721 }
1722 }
1724 /* First look for a dynamic direct non-virtual base. */
1726 {
1730 {
1733 }
1734 }
1736 /* A "nearly-empty" virtual base class can be the primary base
1737 class, if no non-virtual polymorphic base can be found. Look for
1738 a nearly-empty virtual dynamic base that is not already a primary
1739 base of something in the hierarchy. If there is no such base,
1740 just pick the first nearly-empty virtual base. */
1746 {
1748 {
1749 /* Found one that is not primary. */
1752 }
1754 /* Remember the first candidate. */
1756 }
1758 found:
1759 /* If we've got a primary base, use it. */
1761 {
1766 /* We are stealing a primary base. */
1770 {
1771 tree delta;
1774 /* A virtual binfo might have been copied from within
1775 another hierarchy. As we're about to use it as a primary
1776 base, make sure the offsets match. */
1781 }
1788 }
1789 }
1791 /* Update the variant types of T. */
1793 void
1795 {
1796 tree variants;
1802 variants;
1804 {
1805 /* These fields are in the _TYPE part of the node, not in
1806 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1816 /* Copy whatever these are holding today. */
1820 }
1821 }
1823 /* Early variant fixups: we apply attributes at the beginning of the class
1824 definition, and we need to fix up any variants that have already been
1825 made via elaborated-type-specifier so that check_qualified_type works. */
1827 void
1829 {
1830 tree variants;
1836 variants;
1838 {
1839 /* These are the two fields that check_qualified_type looks at and
1840 are affected by attributes. */
1843 }
1844 }
1845 \f
1846 /* Set memoizing fields and bits of T (and its variants) for later
1847 use. */
1849 static void
1851 {
1852 /* Fix up variants (if any). */
1856 /* For a class w/o baseclasses, 'finish_struct' has set
1857 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1858 Similarly for a class whose base classes do not have vtables.
1859 When neither of these is true, we might have removed abstract
1860 virtuals (by providing a definition), added some (by declaring
1861 new ones), or redeclared ones from a base class. We need to
1862 recalculate what's really an abstract virtual at this point (by
1863 looking in the vtables). */
1866 /* If this type has a copy constructor or a destructor, force its
1867 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1868 nonzero. This will cause it to be passed by invisible reference
1869 and prevent it from being returned in a register. */
1872 {
1873 tree variants;
1876 {
1879 }
1880 }
1881 }
1883 /* Issue warnings about T having private constructors, but no friends,
1884 and so forth.
1886 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1887 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1888 non-private static member functions. */
1890 static void
1892 {
1895 tree fn;
1898 /* If the class has friends, those entities might create and
1899 access instances, so we should not warn. */
1902 /* We will have warned when the template was declared; there's
1903 no need to warn on every instantiation. */
1905 /* There's no reason to even consider warning about this
1906 class. */
1909 /* We only issue one warning, if more than one applies, because
1910 otherwise, on code like:
1912 class A {
1913 // Oops - forgot `public:'
1914 A();
1915 A(const A&);
1916 ~A();
1917 };
1919 we warn several times about essentially the same problem. */
1921 /* Check to see if all (non-constructor, non-destructor) member
1922 functions are private. (Since there are no friends or
1923 non-private statics, we can't ever call any of the private member
1924 functions.) */
1926 /* We're not interested in compiler-generated methods; they don't
1927 provide any way to call private members. */
1929 {
1931 {
1933 /* A non-private static member function is just like a
1934 friend; it can create and invoke private member
1935 functions, and be accessed without a class
1936 instance. */
1940 /* Keep searching for a static member function. */
1941 }
1944 }
1947 {
1948 /* There are no non-private methods, and there's at least one
1949 private member function that isn't a constructor or
1950 destructor. (If all the private members are
1951 constructors/destructors we want to use the code below that
1952 issues error messages specifically referring to
1953 constructors/destructors.) */
1959 {
1962 }
1964 {
1968 }
1969 }
1971 /* Even if some of the member functions are non-private, the class
1972 won't be useful for much if all the constructors or destructors
1973 are private: such an object can never be created or destroyed. */
1976 {
1979 t);
1981 }
1983 /* Warn about classes that have private constructors and no friends. */
1985 /* Implicitly generated constructors are always public. */
1988 {
1991 /* If a non-template class does not define a copy
1992 constructor, one is defined for it, enabling it to avoid
1993 this warning. For a template class, this does not
1994 happen, and so we would normally get a warning on:
1996 template <class T> class C { private: C(); };
1998 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1999 complete non-template or fully instantiated classes have this
2000 flag set. */
2003 else
2005 {
2007 /* Ideally, we wouldn't count copy constructors (or, in
2008 fact, any constructor that takes an argument of the
2009 class type as a parameter) because such things cannot
2010 be used to construct an instance of the class unless
2011 you already have one. But, for now at least, we're
2012 more generous. */
2014 {
2017 }
2018 }
2021 {
2024 t);
2026 }
2027 }
2028 }
2031 gt_pointer_operator new_value;
2035 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2037 static int
2039 {
2052 }
2054 /* This routine compares two fields like method_name_cmp but using the
2055 pointer operator in resort_field_decl_data. */
2057 static int
2059 {
2068 {
2075 }
2077 }
2079 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2081 void
2084 gt_pointer_operator new_value,
2086 {
2090 tree fn;
2092 /* The type conversion ops have to live at the front of the vec, so we
2093 can't sort them. */
2101 {
2105 resort_method_name_cmp);
2106 }
2107 }
2109 /* Warn about duplicate methods in fn_fields.
2111 Sort methods that are not special (i.e., constructors, destructors,
2112 and type conversion operators) so that we can find them faster in
2113 search. */
2115 static void
2117 {
2118 tree fn_fields;
2128 /* Clear DECL_IN_AGGR_P for all functions. */
2133 /* Issue warnings about private constructors and such. If there are
2134 no methods, then some public defaults are generated. */
2137 /* The type conversion ops have to live at the front of the vec, so we
2138 can't sort them. */
2147 }
2149 /* Make BINFO's vtable have N entries, including RTTI entries,
2150 vbase and vcall offsets, etc. Set its type and call the back end
2151 to lay it out. */
2153 static void
2155 {
2156 tree atype;
2157 tree vtable;
2162 /* We may have to grow the vtable. */
2165 {
2169 }
2170 }
2172 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2173 have the same signature. */
2175 int
2177 {
2178 /* One destructor overrides another if they are the same kind of
2179 destructor. */
2183 /* But a non-destructor never overrides a destructor, nor vice
2184 versa, nor do different kinds of destructors override
2185 one-another. For example, a complete object destructor does not
2186 override a deleting destructor. */
2195 {
2203 }
2205 }
2207 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2208 subobject. */
2210 static bool
2212 {
2213 tree probe;
2216 {
2220 /* If we meet a virtual base, we can't follow the inheritance
2221 any more. See if the complete type of DERIVED contains
2222 such a virtual base. */
2225 }
2227 }
2230 /* The function for which we are trying to find a final overrider. */
2231 tree fn;
2232 /* The base class in which the function was declared. */
2233 tree declaring_base;
2234 /* The candidate overriders. */
2235 tree candidates;
2236 /* Path to most derived. */
2240 /* Add the overrider along the current path to FFOD->CANDIDATES.
2241 Returns true if an overrider was found; false otherwise. */
2243 static bool
2247 {
2248 tree method;
2250 /* If BINFO is not the most derived type, try a more derived class.
2251 A definition there will overrider a definition here. */
2253 {
2254 depth--;
2258 }
2262 {
2265 /* Remove any candidates overridden by this new function. */
2267 {
2268 /* If *CANDIDATE overrides METHOD, then METHOD
2269 cannot override anything else on the list. */
2272 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2275 else
2277 }
2279 /* Add the new function. */
2282 }
2285 }
2287 /* Called from find_final_overrider via dfs_walk. */
2289 static tree
2291 {
2299 }
2301 static tree
2303 {
2308 }
2310 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2311 FN and whose TREE_VALUE is the binfo for the base where the
2312 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2313 DERIVED) is the base object in which FN is declared. */
2315 static tree
2317 {
2318 find_final_overrider_data ffod;
2320 /* Getting this right is a little tricky. This is valid:
2322 struct S { virtual void f (); };
2323 struct T { virtual void f (); };
2324 struct U : public S, public T { };
2326 even though calling `f' in `U' is ambiguous. But,
2328 struct R { virtual void f(); };
2329 struct S : virtual public R { virtual void f (); };
2330 struct T : virtual public R { virtual void f (); };
2331 struct U : public S, public T { };
2333 is not -- there's no way to decide whether to put `S::f' or
2334 `T::f' in the vtable for `R'.
2336 The solution is to look at all paths to BINFO. If we find
2337 different overriders along any two, then there is a problem. */
2341 /* Determine the depth of the hierarchy. */
2352 /* If there was no winner, issue an error message. */
2357 }
2359 /* Return the index of the vcall offset for FN when TYPE is used as a
2360 virtual base. */
2362 static tree
2364 {
2366 tree_pair_p p;
2374 /* There should always be an appropriate index. */
2376 }
2378 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2379 dominated by T. FN is the old function; VIRTUALS points to the
2380 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2381 of that entry in the list. */
2383 static void
2386 {
2387 tree b;
2388 tree overrider;
2389 tree delta;
2390 tree virtual_base;
2391 tree first_defn;
2397 /* Find the nearest primary base (possibly binfo itself) which defines
2398 this function; this is the class the caller will convert to when
2399 calling FN through BINFO. */
2401 {
2406 /* The nearest definition is from a lost primary. */
2409 }
2412 /* Find the final overrider. */
2415 {
2418 }
2421 /* Check for adjusting covariant return types. */
2429 /* If the overrider is invalid, don't even try. */
2431 {
2432 /* If FN is a covariant thunk, we must figure out the adjustment
2433 to the final base FN was converting to. As OVERRIDER_TARGET might
2434 also be converting to the return type of FN, we have to
2435 combine the two conversions here. */
2442 {
2446 }
2447 else
2451 /* Find the equivalent binfo within the return type of the
2452 overriding function. We will want the vbase offset from
2453 there. */
2455 over_return);
2458 {
2459 /* There was no existing virtual thunk (which takes
2460 precedence). So find the binfo of the base function's
2461 return type within the overriding function's return type.
2462 We cannot call lookup base here, because we're inside a
2463 dfs_walk, and will therefore clobber the BINFO_MARKED
2464 flags. Fortunately we know the covariancy is valid (it
2465 has already been checked), so we can just iterate along
2466 the binfos, which have been chained in inheritance graph
2467 order. Of course it is lame that we have to repeat the
2468 search here anyway -- we should really be caching pieces
2469 of the vtable and avoiding this repeated work. */
2472 /* Find the base binfo within the overriding function's
2473 return type. We will always find a thunk_binfo, except
2474 when the covariancy is invalid (which we will have
2475 already diagnosed). */
2478 thunk_binfo;
2484 /* See if virtual inheritance is involved. */
2486 virtual_offset;
2493 {
2497 {
2498 /* We convert via virtual base. Adjust the fixed
2499 offset to be from there. */
2500 offset =
2504 }
2506 /* There was an existing fixed offset, this must be
2507 from the base just converted to, and the base the
2508 FN was thunking to. */
2510 else
2512 }
2513 }
2516 /* Replace the overriding function with a covariant thunk. We
2517 will emit the overriding function in its own slot as
2518 well. */
2521 }
2522 else
2526 /* If we need a covariant thunk, then we may need to adjust first_defn.
2527 The ABI specifies that the thunks emitted with a function are
2528 determined by which bases the function overrides, so we need to be
2529 sure that we're using a thunk for some overridden base; even if we
2530 know that the necessary this adjustment is zero, there may not be an
2531 appropriate zero-this-adjusment thunk for us to use since thunks for
2532 overriding virtual bases always use the vcall offset.
2534 Furthermore, just choosing any base that overrides this function isn't
2535 quite right, as this slot won't be used for calls through a type that
2536 puts a covariant thunk here. Calling the function through such a type
2537 will use a different slot, and that slot is the one that determines
2538 the thunk emitted for that base.
2540 So, keep looking until we find the base that we're really overriding
2541 in this slot: the nearest primary base that doesn't use a covariant
2542 thunk in this slot. */
2544 {
2546 /* We already know that the overrider needs a covariant thunk. */
2549 {
2556 }
2558 }
2560 /* Assume that we will produce a thunk that convert all the way to
2561 the final overrider, and not to an intermediate virtual base. */
2564 /* See if we can convert to an intermediate virtual base first, and then
2565 use the vcall offset located there to finish the conversion. */
2567 {
2568 /* If we find the final overrider, then we can stop
2569 walking. */
2574 /* If we find a virtual base, and we haven't yet found the
2575 overrider, then there is a virtual base between the
2576 declaring base (first_defn) and the final overrider. */
2578 {
2581 }
2582 }
2584 /* Compute the constant adjustment to the `this' pointer. The
2585 `this' pointer, when this function is called, will point at BINFO
2586 (or one of its primary bases, which are at the same offset). */
2588 /* The `this' pointer needs to be adjusted from the declaration to
2589 the nearest virtual base. */
2594 /* If the nearest definition is in a lost primary, we don't need an
2595 entry in our vtable. Except possibly in a constructor vtable,
2596 if we happen to get our primary back. In that case, the offset
2597 will be zero, as it will be a primary base. */
2599 else
2600 /* The `this' pointer needs to be adjusted from pointing to
2601 BINFO to pointing at the base where the final overrider
2602 appears. */
2613 else
2617 }
2619 /* Called from modify_all_vtables via dfs_walk. */
2621 static tree
2623 {
2625 tree virtuals;
2626 tree old_virtuals;
2630 /* A base without a vtable needs no modification, and its bases
2631 are uninteresting. */
2636 /* Don't do the primary vtable, if it's new. */
2640 /* There's no need to modify the vtable for a non-virtual primary
2641 base; we're not going to use that vtable anyhow. We do still
2642 need to do this for virtual primary bases, as they could become
2643 non-primary in a construction vtable. */
2648 /* Now, go through each of the virtual functions in the virtual
2649 function table for BINFO. Find the final overrider, and update
2650 the BINFO_VIRTUALS list appropriately. */
2653 virtuals;
2657 binfo,
2662 }
2664 /* Update all of the primary and secondary vtables for T. Create new
2665 vtables as required, and initialize their RTTI information. Each
2666 of the functions in VIRTUALS is declared in T and may override a
2667 virtual function from a base class; find and modify the appropriate
2668 entries to point to the overriding functions. Returns a list, in
2669 declaration order, of the virtual functions that are declared in T,
2670 but do not appear in the primary base class vtable, and which
2671 should therefore be appended to the end of the vtable for T. */
2673 static tree
2675 {
2679 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2683 /* Update all of the vtables. */
2686 /* Add virtual functions not already in our primary vtable. These
2687 will be both those introduced by this class, and those overridden
2688 from secondary bases. It does not include virtuals merely
2689 inherited from secondary bases. */
2691 {
2696 {
2697 /* We don't need to adjust the `this' pointer when
2698 calling this function. */
2702 /* This is a function not already in our vtable. Keep it. */
2704 }
2705 else
2706 /* We've already got an entry for this function. Skip it. */
2708 }
2711 }
2713 /* Get the base virtual function declarations in T that have the
2714 indicated NAME. */
2716 static tree
2718 {
2719 tree methods;
2724 /* Find virtual functions in T with the indicated NAME. */
2728 methods;
2730 {
2736 }
2742 {
2745 base_fndecls);
2746 }
2749 }
2751 /* If this declaration supersedes the declaration of
2752 a method declared virtual in the base class, then
2753 mark this field as being virtual as well. */
2755 void
2757 {
2760 /* In [temp.mem] we have:
2762 A specialization of a member function template does not
2763 override a virtual function from a base class. */
2770 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2771 the error_mark_node so that we know it is an overriding
2772 function. */
2773 {
2776 }
2779 {
2785 }
2790 }
2792 /* Warn about hidden virtual functions that are not overridden in t.
2793 We know that constructors and destructors don't apply. */
2795 static void
2797 {
2799 tree fns;
2802 /* We go through each separately named virtual function. */
2806 {
2807 tree fn;
2808 tree name;
2809 tree fndecl;
2810 tree base_fndecls;
2811 tree base_binfo;
2812 tree binfo;
2815 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2816 have the same name. Figure out what name that is. */
2818 /* There are no possibly hidden functions yet. */
2820 /* Iterate through all of the base classes looking for possibly
2821 hidden functions. */
2824 {
2827 base_fndecls);
2828 }
2830 /* If there are no functions to hide, continue. */
2834 /* Remove any overridden functions. */
2836 {
2839 {
2843 /* If the method from the base class has the same
2844 signature as the method from the derived class, it
2845 has been overridden. */
2848 else
2850 }
2851 }
2853 /* Now give a warning for all base functions without overriders,
2854 as they are hidden. */
2856 {
2857 /* Here we know it is a hider, and no overrider exists. */
2861 }
2862 }
2863 }
2865 /* Recursive helper for finish_struct_anon. */
2867 static void
2869 {
2873 {
2874 /* We're generally only interested in entities the user
2875 declared, but we also find nested classes by noticing
2876 the TYPE_DECL that we create implicitly. You're
2877 allowed to put one anonymous union inside another,
2878 though, so we explicitly tolerate that. We use
2879 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2880 we also allow unnamed types used for defining fields. */
2887 {
2888 /* We already complained about static data members in
2889 finish_static_data_member_decl. */
2891 {
2894 "%q+#D invalid; an anonymous union can "
2896 else
2898 "%q+#D invalid; an anonymous struct can "
2900 }
2902 }
2905 {
2907 {
2911 else
2914 }
2916 {
2920 else
2923 }
2924 }
2929 /* Recurse into the anonymous aggregates to handle correctly
2930 access control (c++/24926):
2932 class A {
2933 union {
2934 union {
2935 int i;
2936 };
2937 };
2938 };
2940 int j=A().i; */
2944 }
2945 }
2947 /* Check for things that are invalid. There are probably plenty of other
2948 things we should check for also. */
2950 static void
2952 {
2954 {
2963 }
2964 }
2966 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2967 will be used later during class template instantiation.
2968 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2969 a non-static member data (FIELD_DECL), a member function
2970 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2971 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2972 When FRIEND_P is nonzero, T is either a friend class
2973 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2974 (FUNCTION_DECL, TEMPLATE_DECL). */
2976 void
2978 {
2979 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2984 }
2986 /* This function is called from declare_virt_assop_and_dtor via
2987 dfs_walk_all.
2989 DATA is a type that direcly or indirectly inherits the base
2990 represented by BINFO. If BINFO contains a virtual assignment [copy
2991 assignment or move assigment] operator or a virtual constructor,
2992 declare that function in DATA if it hasn't been already declared. */
2994 static tree
2996 {
3004 /* A base without a vtable needs no modification, and its bases
3005 are uninteresting. */
3009 /* If this is a primary base, then we have already looked at the
3010 virtual functions of its vtable. */
3014 {
3018 {
3023 }
3027 }
3030 }
3032 /* If the class type T has a direct or indirect base that contains a
3033 virtual assignment operator or a virtual destructor, declare that
3034 function in T if it hasn't been already declared. */
3036 static void
3038 {
3046 dfs_declare_virt_assop_and_dtor,
3048 }
3050 /* Declare the inheriting constructor for class T inherited from base
3051 constructor CTOR with the parameter array PARMS of size NPARMS. */
3053 static void
3055 {
3056 /* We don't declare an inheriting ctor that would be a default,
3057 copy or move ctor for derived or base. */
3062 {
3066 }
3074 {
3077 }
3078 }
3080 /* Declare all the inheriting constructors for class T inherited from base
3081 constructor CTOR. */
3083 static void
3085 {
3091 {
3095 }
3098 {
3102 }
3103 }
3105 /* Create default constructors, assignment operators, and so forth for
3106 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3107 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3108 the class cannot have a default constructor, copy constructor
3109 taking a const reference argument, or an assignment operator taking
3110 a const reference, respectively. */
3112 static void
3116 {
3124 /* Destructor. */
3126 {
3127 /* In general, we create destructors lazily. */
3132 /* But if this is a Java class, any non-trivial destructor is
3133 invalid, even if compiler-generated. Therefore, if the
3134 destructor is non-trivial we create it now. */
3136 }
3138 /* [class.ctor]
3140 If there is no user-declared constructor for a class, a default
3141 constructor is implicitly declared. */
3143 {
3148 /* This might force the declaration. */
3150 }
3152 /* [class.ctor]
3154 If a class definition does not explicitly declare a copy
3155 constructor, one is declared implicitly. */
3157 {
3163 }
3165 /* If there is no assignment operator, one will be created if and
3166 when it is needed. For now, just record whether or not the type
3167 of the parameter to the assignment operator will be a const or
3168 non-const reference. */
3170 {
3176 }
3178 /* We can't be lazy about declaring functions that might override
3179 a virtual function from a base class. */
3183 {
3187 {
3188 /* declare, then remove the decl */
3197 }
3198 else
3200 }
3201 }
3203 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3204 count the number of fields in TYPE, including anonymous union
3205 members. */
3207 static int
3209 {
3210 tree x;
3213 {
3216 else
3218 }
3220 }
3222 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3223 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3224 elts, starting at offset IDX. */
3226 static int
3228 {
3229 tree x;
3231 {
3234 else
3236 }
3238 }
3240 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3241 starting at offset IDX. */
3243 static int
3247 {
3248 tree values;
3252 }
3254 /* FIELD is a bit-field. We are finishing the processing for its
3255 enclosing type. Issue any appropriate messages and set appropriate
3256 flags. Returns false if an error has been diagnosed. */
3258 static bool
3260 {
3262 tree w;
3264 /* Extract the declared width of the bitfield, which has been
3265 temporarily stashed in DECL_INITIAL. */
3268 /* Remove the bit-field width indicator so that the rest of the
3269 compiler does not treat that value as an initializer. */
3272 /* Detect invalid bit-field type. */
3274 {
3277 }
3278 else
3279 {
3281 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3284 /* detect invalid field size. */
3290 {
3293 }
3295 {
3298 }
3300 {
3303 }
3315 }
3318 {
3322 }
3323 else
3324 {
3325 /* Non-bit-fields are aligned for their type. */
3329 }
3330 }
3332 /* FIELD is a non bit-field. We are finishing the processing for its
3333 enclosing type T. Issue any appropriate messages and set appropriate
3334 flags. */
3336 static void
3338 tree t,
3342 {
3345 /* In C++98 an anonymous union cannot contain any fields which would change
3346 the settings of CANT_HAVE_CONST_CTOR and friends. */
3348 ;
3349 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3350 structs. So, we recurse through their fields here. */
3352 {
3353 tree fields;
3359 }
3360 /* Check members with class type for constructors, destructors,
3361 etc. */
3363 {
3364 /* Never let anything with uninheritable virtuals
3365 make it through without complaint. */
3369 {
3374 field);
3379 field);
3381 {
3385 }
3386 }
3387 else
3388 {
3401 }
3410 }
3415 {
3416 /* `build_class_init_list' does not recognize
3417 non-FIELD_DECLs. */
3421 }
3422 }
3424 /* Check the data members (both static and non-static), class-scoped
3425 typedefs, etc., appearing in the declaration of T. Issue
3426 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3427 declaration order) of access declarations; each TREE_VALUE in this
3428 list is a USING_DECL.
3430 In addition, set the following flags:
3432 EMPTY_P
3433 The class is empty, i.e., contains no non-static data members.
3435 CANT_HAVE_CONST_CTOR_P
3436 This class cannot have an implicitly generated copy constructor
3437 taking a const reference.
3439 CANT_HAVE_CONST_ASN_REF
3440 This class cannot have an implicitly generated assignment
3441 operator taking a const reference.
3443 All of these flags should be initialized before calling this
3444 function.
3446 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3447 fields can be added by adding to this chain. */
3449 static void
3453 {
3461 /* Assume there are no access declarations. */
3463 /* Assume this class has no pointer members. */
3465 /* Assume none of the members of this class have default
3466 initializations. */
3470 {
3478 {
3479 /* Save the access declarations for our caller. */
3482 }
3488 /* If we've gotten this far, it's a data member, possibly static,
3489 or an enumerator. */
3493 /* When this goes into scope, it will be a non-local reference. */
3497 {
3498 /* [class.union]
3500 If a union contains a static data member, or a member of
3501 reference type, the program is ill-formed. */
3503 {
3506 }
3508 {
3513 }
3514 }
3516 /* Perform error checking that did not get done in
3517 grokdeclarator. */
3519 {
3523 }
3525 {
3529 }
3537 /* Now it can only be a FIELD_DECL. */
3542 /* If at least one non-static data member is non-literal, the whole
3543 class becomes non-literal. Note: if the type is incomplete we
3544 will complain later on. */
3548 /* A standard-layout class is a class that:
3549 ...
3550 has the same access control (Clause 11) for all non-static data members,
3551 ... */
3558 /* If this is of reference type, check if it needs an init. */
3560 {
3566 /* ARM $12.6.2: [A member initializer list] (or, for an
3567 aggregate, initialization by a brace-enclosed list) is the
3568 only way to initialize nonstatic const and reference
3569 members. */
3572 }
3577 {
3579 {
3580 warning
3583 x);
3585 }
3589 }
3592 /* We don't treat zero-width bitfields as making a class
3593 non-empty. */
3594 ;
3595 else
3596 {
3597 /* The class is non-empty. */
3599 /* The class is not even nearly empty. */
3601 /* If one of the data members contains an empty class,
3602 so does T. */
3606 }
3608 /* This is used by -Weffc++ (see below). Warn only for pointers
3609 to members which might hold dynamic memory. So do not warn
3610 for pointers to functions or pointers to members. */
3616 {
3621 }
3627 {
3629 {
3633 }
3635 {
3639 }
3640 }
3643 /* DR 148 now allows pointers to members (which are POD themselves),
3644 to be allowed in POD structs. */
3653 /* We set DECL_C_BIT_FIELD in grokbitfield.
3654 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3657 cant_have_const_ctor_p,
3658 no_const_asn_ref_p,
3661 /* Now that we've removed bit-field widths from DECL_INITIAL,
3662 anything left in DECL_INITIAL is an NSDMI that makes the class
3663 non-aggregate. */
3667 /* If any field is const, the structure type is pseudo-const. */
3669 {
3674 /* ARM $12.6.2: [A member initializer list] (or, for an
3675 aggregate, initialization by a brace-enclosed list) is the
3676 only way to initialize nonstatic const and reference
3677 members. */
3680 }
3681 /* A field that is pseudo-const makes the structure likewise. */
3683 {
3688 }
3690 /* Core issue 80: A nonstatic data member is required to have a
3691 different name from the class iff the class has a
3692 user-declared constructor. */
3696 }
3698 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3699 it should also define a copy constructor and an assignment operator to
3700 implement the correct copy semantic (deep vs shallow, etc.). As it is
3701 not feasible to check whether the constructors do allocate dynamic memory
3702 and store it within members, we approximate the warning like this:
3704 -- Warn only if there are members which are pointers
3705 -- Warn only if there is a non-trivial constructor (otherwise,
3706 there cannot be memory allocated).
3707 -- Warn only if there is a non-trivial destructor. We assume that the
3708 user at least implemented the cleanup correctly, and a destructor
3709 is needed to free dynamic memory.
3711 This seems enough for practical purposes. */
3713 && has_pointers
3717 {
3721 {
3726 }
3730 }
3732 /* Non-static data member initializers make the default constructor
3733 non-trivial. */
3735 {
3738 }
3740 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3744 /* Check anonymous struct/anonymous union fields. */
3747 /* We've built up the list of access declarations in reverse order.
3748 Fix that now. */
3750 }
3752 /* If TYPE is an empty class type, records its OFFSET in the table of
3753 OFFSETS. */
3755 static int
3757 {
3758 splay_tree_node n;
3763 /* Record the location of this empty object in OFFSETS. */
3771 type,
3775 }
3777 /* Returns nonzero if TYPE is an empty class type and there is
3778 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3780 static int
3782 {
3783 splay_tree_node n;
3784 tree t;
3789 /* Record the location of this empty object in OFFSETS. */
3799 }
3801 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3802 F for every subobject, passing it the type, offset, and table of
3803 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3804 be traversed.
3806 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3807 than MAX_OFFSET will not be walked.
3809 If F returns a nonzero value, the traversal ceases, and that value
3810 is returned. Otherwise, returns zero. */
3812 static int
3814 subobject_offset_fn f,
3815 tree offset,
3816 splay_tree offsets,
3817 tree max_offset,
3819 {
3823 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3824 stop. */
3832 {
3836 }
3839 {
3840 tree field;
3841 tree binfo;
3844 /* Avoid recursing into objects that are not interesting. */
3848 /* Record the location of TYPE. */
3853 /* Iterate through the direct base classes of TYPE. */
3857 {
3858 tree binfo_offset;
3871 offset,
3873 else
3874 {
3875 tree orig_binfo;
3876 /* We cannot rely on BINFO_OFFSET being set for the base
3877 class yet, but the offsets for direct non-virtual
3878 bases can be calculated by going back to the TYPE. */
3881 offset,
3883 }
3886 f,
3887 binfo_offset,
3888 offsets,
3889 max_offset,
3894 }
3897 {
3901 /* Iterate through the virtual base classes of TYPE. In G++
3902 3.2, we included virtual bases in the direct base class
3903 loop above, which results in incorrect results; the
3904 correct offsets for virtual bases are only known when
3905 working with the most derived type. */
3909 {
3911 f,
3913 offset,
3915 offsets,
3916 max_offset,
3920 }
3921 else
3922 {
3923 /* We still have to walk the primary base, if it is
3924 virtual. (If it is non-virtual, then it was walked
3925 above.) */
3931 {
3932 r = (walk_subobject_offsets
3937 }
3938 }
3939 }
3941 /* Iterate through the fields of TYPE. */
3946 {
3947 tree field_offset;
3951 else
3952 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3956 f,
3958 offset,
3959 field_offset),
3960 offsets,
3961 max_offset,
3965 }
3966 }
3968 {
3971 tree index;
3973 /* Avoid recursing into objects that are not interesting. */
3978 /* Step through each of the elements in the array. */
3980 /* G++ 3.2 had an off-by-one error here. */
3985 {
3987 f,
3988 offset,
3989 offsets,
3990 max_offset,
3996 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3997 there's no point in iterating through the remaining
3998 elements of the array. */
4001 }
4002 }
4005 }
4007 /* Record all of the empty subobjects of TYPE (either a type or a
4008 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4009 is being placed at OFFSET; otherwise, it is a base class that is
4010 being placed at OFFSET. */
4012 static void
4014 tree offset,
4015 splay_tree offsets,
4017 {
4018 tree max_offset;
4019 /* If recording subobjects for a non-static data member or a
4020 non-empty base class , we do not need to record offsets beyond
4021 the size of the biggest empty class. Additional data members
4022 will go at the end of the class. Additional base classes will go
4023 either at offset zero (if empty, in which case they cannot
4024 overlap with offsets past the size of the biggest empty class) or
4025 at the end of the class.
4027 However, if we are placing an empty base class, then we must record
4028 all offsets, as either the empty class is at offset zero (where
4029 other empty classes might later be placed) or at the end of the
4030 class (where other objects might then be placed, so other empty
4031 subobjects might later overlap). */
4035 else
4039 }
4041 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4042 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4043 virtual bases of TYPE are examined. */
4045 static int
4047 tree offset,
4048 splay_tree offsets,
4050 {
4051 splay_tree_node max_node;
4053 /* Get the node in OFFSETS that indicates the maximum offset where
4054 an empty subobject is located. */
4056 /* If there aren't any empty subobjects, then there's no point in
4057 performing this check. */
4063 vbases_p);
4064 }
4066 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4067 non-static data member of the type indicated by RLI. BINFO is the
4068 binfo corresponding to the base subobject, OFFSETS maps offsets to
4069 types already located at those offsets. This function determines
4070 the position of the DECL. */
4072 static void
4074 tree decl,
4075 tree binfo,
4076 splay_tree offsets)
4077 {
4080 tree type;
4083 {
4084 /* For the purposes of determining layout conflicts, we want to
4085 use the class type of BINFO; TREE_TYPE (DECL) will be the
4086 CLASSTYPE_AS_BASE version, which does not contain entries for
4087 zero-sized bases. */
4090 }
4091 else
4092 {
4095 }
4097 /* Try to place the field. It may take more than one try if we have
4098 a hard time placing the field without putting two objects of the
4099 same type at the same address. */
4101 {
4104 /* Place this field. */
4108 /* We have to check to see whether or not there is already
4109 something of the same type at the offset we're about to use.
4110 For example, consider:
4112 struct S {};
4113 struct T : public S { int i; };
4114 struct U : public S, public T {};
4116 Here, we put S at offset zero in U. Then, we can't put T at
4117 offset zero -- its S component would be at the same address
4118 as the S we already allocated. So, we have to skip ahead.
4119 Since all data members, including those whose type is an
4120 empty class, have nonzero size, any overlap can happen only
4121 with a direct or indirect base-class -- it can't happen with
4122 a data member. */
4123 /* In a union, overlap is permitted; all members are placed at
4124 offset zero. */
4127 /* G++ 3.2 did not check for overlaps when placing a non-empty
4128 virtual base. */
4133 {
4134 /* Strip off the size allocated to this field. That puts us
4135 at the first place we could have put the field with
4136 proper alignment. */
4139 /* Bump up by the alignment required for the type. */
4140 rli->bitpos
4146 }
4147 else
4148 /* There was no conflict. We're done laying out this field. */
4150 }
4152 /* Now that we know where it will be placed, update its
4153 BINFO_OFFSET. */
4155 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4156 this point because their BINFO_OFFSET is copied from another
4157 hierarchy. Therefore, we may not need to add the entire
4158 OFFSET. */
4164 }
4166 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4168 static int
4170 tree offset,
4172 {
4174 }
4176 /* Layout the empty base BINFO. EOC indicates the byte currently just
4177 past the end of the class, and should be correctly aligned for a
4178 class of the type indicated by BINFO; OFFSETS gives the offsets of
4179 the empty bases allocated so far. T is the most derived
4180 type. Return nonzero iff we added it at the end. */
4182 static bool
4185 {
4186 tree alignment;
4190 /* This routine should only be used for empty classes. */
4195 {
4197 propagate_binfo_offsets
4200 else
4202 "offset of empty base %qT may not be ABI-compliant and may"
4205 }
4207 /* This is an empty base class. We first try to put it at offset
4208 zero. */
4211 offsets,
4213 {
4214 /* That didn't work. Now, we move forward from the next
4215 available spot in the class. */
4219 {
4222 offsets,
4224 /* We finally found a spot where there's no overlap. */
4227 /* There's overlap here, too. Bump along to the next spot. */
4229 }
4230 }
4233 {
4238 }
4241 }
4243 /* Layout the base given by BINFO in the class indicated by RLI.
4244 *BASE_ALIGN is a running maximum of the alignments of
4245 any base class. OFFSETS gives the location of empty base
4246 subobjects. T is the most derived type. Return nonzero if the new
4247 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4248 *NEXT_FIELD, unless BINFO is for an empty base class.
4250 Returns the location at which the next field should be inserted. */
4255 {
4260 /* This error is now reported in xref_tag, thus giving better
4261 location information. */
4264 /* Place the base class. */
4266 {
4267 tree decl;
4269 /* The containing class is non-empty because it has a non-empty
4270 base class. */
4273 /* Create the FIELD_DECL. */
4280 {
4288 /* Try to place the field. It may take more than one try if we
4289 have a hard time placing the field without putting two
4290 objects of the same type at the same address. */
4292 /* Add the new FIELD_DECL to the list of fields for T. */
4296 }
4297 }
4298 else
4299 {
4300 tree eoc;
4303 /* On some platforms (ARM), even empty classes will not be
4304 byte-aligned. */
4309 /* A nearly-empty class "has no proper base class that is empty,
4310 not morally virtual, and at an offset other than zero." */
4312 {
4315 /* The check above (used in G++ 3.2) is insufficient because
4316 an empty class placed at offset zero might itself have an
4317 empty base at a nonzero offset. */
4319 empty_base_at_nonzero_offset_p,
4320 size_zero_node,
4324 {
4327 else
4329 "class %qT will be considered nearly empty in a "
4331 }
4332 }
4334 /* We do not create a FIELD_DECL for empty base classes because
4335 it might overlap some other field. We want to be able to
4336 create CONSTRUCTORs for the class by iterating over the
4337 FIELD_DECLs, and the back end does not handle overlapping
4338 FIELD_DECLs. */
4340 /* An empty virtual base causes a class to be non-empty
4341 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4342 here because that was already done when the virtual table
4343 pointer was created. */
4344 }
4346 /* Record the offsets of BINFO and its base subobjects. */
4349 offsets,
4353 }
4355 /* Layout all of the non-virtual base classes. Record empty
4356 subobjects in OFFSETS. T is the most derived type. Return nonzero
4357 if the type cannot be nearly empty. The fields created
4358 corresponding to the base classes will be inserted at
4359 *NEXT_FIELD. */
4361 static void
4364 {
4365 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4366 subobjects. */
4371 /* The primary base class is always allocated first. */
4376 /* Now allocate the rest of the bases. */
4378 {
4379 tree base_binfo;
4383 /* The primary base was already allocated above, so we don't
4384 need to allocate it again here. */
4388 /* Virtual bases are added at the end (a primary virtual base
4389 will have already been added). */
4395 }
4396 }
4398 /* Go through the TYPE_METHODS of T issuing any appropriate
4399 diagnostics, figuring out which methods override which other
4400 methods, and so forth. */
4402 static void
4404 {
4405 tree x;
4408 {
4412 /* The name of the field is the original field name
4413 Save this in auxiliary field for later overloading. */
4415 {
4419 }
4420 /* All user-provided destructors are non-trivial.
4421 Constructors and assignment ops are handled in
4422 grok_special_member_properties. */
4425 }
4426 }
4428 /* FN is a constructor or destructor. Clone the declaration to create
4429 a specialized in-charge or not-in-charge version, as indicated by
4430 NAME. */
4432 static tree
4434 {
4435 tree parms;
4436 tree clone;
4438 /* Copy the function. */
4440 /* Reset the function name. */
4443 /* Remember where this function came from. */
4445 /* Make it easy to find the CLONE given the FN. */
4449 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4451 {
4458 }
4461 /* There's no pending inline data for this function. */
4465 /* The base-class destructor is not virtual. */
4467 {
4471 }
4473 /* If there was an in-charge parameter, drop it from the function
4474 type. */
4476 {
4477 tree basetype;
4478 tree parmtypes;
4479 tree exceptions;
4484 /* Skip the `this' parameter. */
4486 /* Skip the in-charge parameter. */
4488 /* And the VTT parm, in a complete [cd]tor. */
4492 /* If this is subobject constructor or destructor, add the vtt
4493 parameter. */
4497 parmtypes);
4500 exceptions);
4504 }
4506 /* Copy the function parameters. */
4508 /* Remove the in-charge parameter. */
4510 {
4514 }
4515 /* And the VTT parm, in a complete [cd]tor. */
4517 {
4520 else
4521 {
4525 }
4526 }
4529 {
4532 }
4534 /* Create the RTL for this function. */
4542 }
4544 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4545 not invoke this function directly.
4547 For a non-thunk function, returns the address of the slot for storing
4548 the function it is a clone of. Otherwise returns NULL_TREE.
4550 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4551 cloned_function is unset. This is to support the separate
4552 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4553 on a template makes sense, but not the former. */
4555 tree *
4557 {
4565 {
4566 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4569 else
4570 #endif
4572 }
4577 else
4579 }
4581 /* Produce declarations for all appropriate clones of FN. If
4582 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4583 CLASTYPE_METHOD_VEC as well. */
4585 void
4587 {
4588 tree clone;
4590 /* Avoid inappropriate cloning. */
4596 {
4597 /* For each constructor, we need two variants: an in-charge version
4598 and a not-in-charge version. */
4605 }
4606 else
4607 {
4610 /* For each destructor, we need three variants: an in-charge
4611 version, a not-in-charge version, and an in-charge deleting
4612 version. We clone the deleting version first because that
4613 means it will go second on the TYPE_METHODS list -- and that
4614 corresponds to the correct layout order in the virtual
4615 function table.
4617 For a non-virtual destructor, we do not build a deleting
4618 destructor. */
4620 {
4624 }
4631 }
4633 /* Note that this is an abstract function that is never emitted. */
4635 }
4637 /* DECL is an in charge constructor, which is being defined. This will
4638 have had an in class declaration, from whence clones were
4639 declared. An out-of-class definition can specify additional default
4640 arguments. As it is the clones that are involved in overload
4641 resolution, we must propagate the information from the DECL to its
4642 clones. */
4644 void
4646 {
4647 tree clone;
4651 {
4658 /* Skip the 'this' parameter. */
4674 {
4679 {
4680 /* A default parameter has been added. Adjust the
4681 clone's parameters. */
4685 tree type;
4690 {
4693 clone_parms);
4695 }
4698 clone_parms);
4707 }
4708 }
4710 }
4711 }
4713 /* For each of the constructors and destructors in T, create an
4714 in-charge and not-in-charge variant. */
4716 static void
4718 {
4719 tree fns;
4721 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4722 out now. */
4730 }
4732 /* Deduce noexcept for a destructor DTOR. */
4734 void
4736 {
4738 {
4745 }
4746 }
4748 /* For each destructor in T, deduce noexcept:
4750 12.4/3: A declaration of a destructor that does not have an
4751 exception-specification is implicitly considered to have the
4752 same exception-specification as an implicit declaration (15.4). */
4754 static void
4756 {
4757 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4758 out now. */
4764 }
4766 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4767 of TYPE for virtual functions which FNDECL overrides. Return a
4768 mask of the tm attributes found therein. */
4770 static int
4772 {
4774 tree base_binfo;
4778 {
4788 else
4790 }
4793 }
4795 /* Subroutine of set_method_tm_attributes. Handle the checks and
4796 inheritance for one virtual method FNDECL. */
4798 static void
4800 {
4801 tree tm_attr;
4806 /* If FNDECL doesn't actually override anything (i.e. T is the
4807 class that first declares FNDECL virtual), then we're done. */
4814 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4815 tm_pure must match exactly, otherwise no weakening of
4816 tm_safe > tm_callable > nothing. */
4817 /* ??? The tm_pure attribute didn't make the transition to the
4818 multivendor language spec. */
4820 {
4822 {
4825 }
4826 }
4827 /* If the overridden function is tm_pure, then FNDECL must be. */
4830 /* Look for base class combinations that cannot be satisfied. */
4832 {
4838 }
4839 /* If FNDECL did not declare an attribute, then inherit the most
4840 restrictive one. */
4842 {
4844 }
4845 /* Otherwise validate that we're not weaker than a function
4846 that is being overridden. */
4847 else
4848 {
4852 }
4855 err_override:
4859 }
4861 /* For each of the methods in T, propagate a class-level tm attribute. */
4863 static void
4865 {
4868 /* Don't bother collecting tm attributes if transactional memory
4869 support is not enabled. */
4873 /* Process virtual methods first, as they inherit directly from the
4874 base virtual function and also require validation of new attributes. */
4876 {
4877 tree vchain;
4880 {
4885 }
4886 }
4888 /* If the class doesn't have an attribute, nothing more to do. */
4893 /* Any method that does not yet have a tm attribute inherits
4894 the one from the class. */
4896 {
4899 }
4900 }
4902 /* Returns true iff class T has a user-defined constructor other than
4903 the default constructor. */
4905 bool
4907 {
4908 tree fns;
4914 {
4921 }
4924 }
4926 /* Returns the defaulted constructor if T has one. Otherwise, returns
4927 NULL_TREE. */
4929 tree
4931 {
4938 {
4942 {
4948 }
4949 }
4952 }
4954 /* Returns true iff FN is a user-provided function, i.e. user-declared
4955 and not defaulted at its first declaration; or explicit, private,
4956 protected, or non-const. */
4958 bool
4960 {
4963 else
4967 }
4969 /* Returns true iff class T has a user-provided constructor. */
4971 bool
4973 {
4974 tree fns;
4982 /* This can happen in error cases; avoid crashing. */
4991 }
4993 /* Returns true iff class T has a user-provided default constructor. */
4995 bool
4997 {
4998 tree fns;
5004 {
5010 }
5013 }
5015 /* TYPE is being used as a virtual base, and has a non-trivial move
5016 assignment. Return true if this is due to there being a user-provided
5017 move assignment in TYPE or one of its subobjects; if there isn't, then
5018 multiple move assignment can't cause any harm. */
5020 bool
5022 {
5023 /* Does the type itself have a user-provided move assignment operator? */
5027 {
5031 }
5033 /* Do any of its bases? */
5035 tree base_binfo;
5040 /* Or non-static data members? */
5042 {
5047 }
5049 /* Seems not. */
5051 }
5053 /* If default-initialization leaves part of TYPE uninitialized, returns
5054 a DECL for the field or TYPE itself (DR 253). */
5056 tree
5058 {
5069 {
5073 }
5078 {
5082 }
5085 }
5087 /* Returns true iff for class T, a trivial synthesized default constructor
5088 would be constexpr. */
5090 bool
5092 {
5093 /* A defaulted trivial default constructor is constexpr
5094 if there is nothing to initialize. */
5097 }
5099 /* Returns true iff class T has a constexpr default constructor. */
5101 bool
5103 {
5104 tree fns;
5107 {
5108 /* The caller should have stripped an enclosing array. */
5111 }
5113 {
5116 /* Non-trivial, we need to check subobject constructors. */
5118 }
5121 }
5123 /* Returns true iff class TYPE has a virtual destructor. */
5125 bool
5127 {
5128 tree dtor;
5136 }
5138 /* Returns true iff class T has a move constructor. */
5140 bool
5142 {
5143 tree fns;
5146 {
5149 }
5159 }
5161 /* Returns true iff class T has a move assignment operator. */
5163 bool
5165 {
5166 tree fns;
5169 {
5172 }
5180 }
5182 /* Returns true iff class T has a move constructor that was explicitly
5183 declared in the class body. Note that this is different from
5184 "user-provided", which doesn't include functions that are defaulted in
5185 the class. */
5187 bool
5189 {
5190 tree fns;
5199 {
5203 }
5206 }
5208 /* Returns true iff class T has a move assignment operator that was
5209 explicitly declared in the class body. */
5211 bool
5213 {
5214 tree fns;
5221 {
5225 }
5228 }
5230 /* Nonzero if we need to build up a constructor call when initializing an
5231 object of this class, either because it has a user-declared constructor
5232 or because it doesn't have a default constructor (so we need to give an
5233 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5234 what you care about is whether or not an object can be produced by a
5235 constructor (e.g. so we don't set TREE_READONLY on const variables of
5236 such type); use this function when what you care about is whether or not
5237 to try to call a constructor to create an object. The latter case is
5238 the former plus some cases of constructors that cannot be called. */
5240 bool
5242 {
5243 tree inner;
5253 /* A user-declared constructor might be private, and a constructor might
5254 be trivial but deleted. */
5257 {
5262 }
5264 }
5266 /* Like type_build_ctor_call, but for destructors. */
5268 bool
5270 {
5271 tree inner;
5280 /* A user-declared destructor might be private, and a destructor might
5281 be trivial but deleted. */
5284 {
5289 }
5291 }
5293 /* Remove all zero-width bit-fields from T. */
5295 static void
5297 {
5302 {
5305 /* We should not be confused by the fact that grokbitfield
5306 temporarily sets the width of the bit field into
5307 DECL_INITIAL (*fieldsp).
5308 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5309 to that width. */
5312 else
5314 }
5315 }
5317 /* Returns TRUE iff we need a cookie when dynamically allocating an
5318 array whose elements have the indicated class TYPE. */
5320 static bool
5322 {
5323 tree fns;
5328 /* If there's a non-trivial destructor, we need a cookie. In order
5329 to iterate through the array calling the destructor for each
5330 element, we'll have to know how many elements there are. */
5334 /* If the usual deallocation function is a two-argument whose second
5335 argument is of type `size_t', then we have to pass the size of
5336 the array to the deallocation function, so we will need to store
5337 a cookie. */
5341 /* If there are no `operator []' members, or the lookup is
5342 ambiguous, then we don't need a cookie. */
5345 /* Loop through all of the functions. */
5347 {
5348 tree fn;
5349 tree second_parm;
5351 /* Select the current function. */
5353 /* See if this function is a one-argument delete function. If
5354 it is, then it will be the usual deallocation function. */
5358 /* Do not consider this function if its second argument is an
5359 ellipsis. */
5362 /* Otherwise, if we have a two-argument function and the second
5363 argument is `size_t', it will be the usual deallocation
5364 function -- unless there is one-argument function, too. */
5368 }
5371 }
5373 /* Finish computing the `literal type' property of class type T.
5375 At this point, we have already processed base classes and
5376 non-static data members. We need to check whether the copy
5377 constructor is trivial, the destructor is trivial, and there
5378 is a trivial default constructor or at least one constexpr
5379 constructor other than the copy constructor. */
5381 static void
5383 {
5384 tree fn;
5400 {
5403 {
5407 }
5408 }
5409 }
5411 /* T is a non-literal type used in a context which requires a constant
5412 expression. Explain why it isn't literal. */
5414 void
5416 {
5426 /* Already explained. */
5435 {
5437 "default constructor, and has no constexpr constructor that "
5441 {
5442 /* Note that we can't simply call locate_ctor because when the
5443 constructor is deleted it just returns NULL_TREE. */
5444 tree fns;
5446 {
5453 {
5456 else
5459 }
5460 }
5461 }
5462 }
5463 else
5464 {
5468 {
5471 {
5476 }
5477 }
5479 {
5480 tree ftype;
5485 {
5490 }
5491 }
5492 }
5493 }
5495 /* Check the validity of the bases and members declared in T. Add any
5496 implicitly-generated functions (like copy-constructors and
5497 assignment operators). Compute various flag bits (like
5498 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5499 level: i.e., independently of the ABI in use. */
5501 static void
5503 {
5504 /* Nonzero if the implicitly generated copy constructor should take
5505 a non-const reference argument. */
5507 /* Nonzero if the implicitly generated assignment operator
5508 should take a non-const reference argument. */
5510 tree access_decls;
5513 tree fn;
5515 /* Pick up any abi_tags from our template arguments before checking. */
5518 /* By default, we use const reference arguments and generate default
5519 constructors. */
5523 /* Check all the base-classes. */
5527 /* Deduce noexcept on destructors. This needs to happen after we've set
5528 triviality flags appropriately for our bases. */
5532 /* Check all the method declarations. */
5535 /* Save the initial values of these flags which only indicate whether
5536 or not the class has user-provided functions. As we analyze the
5537 bases and members we can set these flags for other reasons. */
5541 /* Check all the data member declarations. We cannot call
5542 check_field_decls until we have called check_bases check_methods,
5543 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5544 being set appropriately. */
5549 /* A nearly-empty class has to be vptr-containing; a nearly empty
5550 class contains just a vptr. */
5554 /* Do some bookkeeping that will guide the generation of implicitly
5555 declared member functions. */
5558 /* We need to call a constructor for this class if it has a
5559 user-provided constructor, or if the default constructor is going
5560 to initialize the vptr. (This is not an if-and-only-if;
5561 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5562 themselves need constructing.) */
5565 /* [dcl.init.aggr]
5567 An aggregate is an array or a class with no user-provided
5568 constructors ... and no virtual functions.
5570 Again, other conditions for being an aggregate are checked
5571 elsewhere. */
5574 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5575 retain the old definition internally for ABI reasons. */
5584 /* If the class has no user-declared constructor, but does have
5585 non-static const or reference data members that can never be
5586 initialized, issue a warning. */
5588 /* Classes with user-declared constructors are presumed to
5589 initialize these members. */
5591 /* Aggregates can be initialized with brace-enclosed
5592 initializers. */
5594 {
5595 tree field;
5598 {
5599 tree type;
5614 }
5615 }
5617 /* Synthesize any needed methods. */
5619 cant_have_const_ctor,
5620 no_const_asn_ref);
5622 /* Check defaulted declarations here so we have cant_have_const_ctor
5623 and don't need to worry about clones. */
5626 {
5629 {
5630 bool imp_const_p
5636 /* If the function is defaulted outside the class, we just
5637 give the synthesis error. */
5640 }
5642 }
5645 {
5646 /* "The closure type associated with a lambda-expression has a deleted
5647 default constructor and a deleted copy assignment operator." */
5653 /* "This class type is not an aggregate." */
5655 }
5657 /* Compute the 'literal type' property before we
5658 do anything with non-static member functions. */
5661 /* Create the in-charge and not-in-charge variants of constructors
5662 and destructors. */
5665 /* Process the using-declarations. */
5669 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5672 /* Figure out whether or not we will need a cookie when dynamically
5673 allocating an array of this type. */
5676 }
5678 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5679 accordingly. If a new vfield was created (because T doesn't have a
5680 primary base class), then the newly created field is returned. It
5681 is not added to the TYPE_FIELDS list; it is the caller's
5682 responsibility to do that. Accumulate declared virtual functions
5683 on VIRTUALS_P. */
5685 static tree
5687 {
5688 tree fn;
5690 /* Collect the virtual functions declared in T. */
5694 {
5703 }
5705 /* If we couldn't find an appropriate base class, create a new field
5706 here. Even if there weren't any new virtual functions, we might need a
5707 new virtual function table if we're supposed to include vptrs in
5708 all classes that need them. */
5710 {
5711 /* We build this decl with vtbl_ptr_type_node, which is a
5712 `vtable_entry_type*'. It might seem more precise to use
5713 `vtable_entry_type (*)[N]' where N is the number of virtual
5714 functions. However, that would require the vtable pointer in
5715 base classes to have a different type than the vtable pointer
5716 in derived classes. We could make that happen, but that
5717 still wouldn't solve all the problems. In particular, the
5718 type-based alias analysis code would decide that assignments
5719 to the base class vtable pointer can't alias assignments to
5720 the derived class vtable pointer, since they have different
5721 types. Thus, in a derived class destructor, where the base
5722 class constructor was inlined, we could generate bad code for
5723 setting up the vtable pointer.
5725 Therefore, we use one type for all vtable pointers. We still
5726 use a type-correct type; it's just doesn't indicate the array
5727 bounds. That's better than using `void*' or some such; it's
5728 cleaner, and it let's the alias analysis code know that these
5729 stores cannot alias stores to void*! */
5730 tree field;
5743 /* This class is non-empty. */
5747 }
5750 }
5752 /* Add OFFSET to all base types of BINFO which is a base in the
5753 hierarchy dominated by T.
5755 OFFSET, which is a type offset, is number of bytes. */
5757 static void
5759 {
5761 tree primary_binfo;
5762 tree base_binfo;
5764 /* Update BINFO's offset. */
5769 offset));
5771 /* Find the primary base class. */
5777 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5778 downwards. */
5780 {
5781 /* Don't do the primary base twice. */
5789 }
5790 }
5792 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5793 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5794 empty subobjects of T. */
5796 static void
5798 {
5799 tree vbase;
5808 {
5809 /* In G++ 3.2, we incorrectly rounded the size before laying out
5810 the virtual bases. */
5812 #ifdef STRUCTURE_SIZE_BOUNDARY
5813 /* Packed structures don't need to have minimum size. */
5816 #endif
5820 }
5822 /* Find the last field. The artificial fields created for virtual
5823 bases will go after the last extant field to date. */
5828 /* Go through the virtual bases, allocating space for each virtual
5829 base that is not already a primary base class. These are
5830 allocated in inheritance graph order. */
5832 {
5837 {
5840 /* This virtual base is not a primary base of any class in the
5841 hierarchy, so we have to add space for it. */
5845 /* If the first virtual base might have been placed at a
5846 lower address, had we started from CLASSTYPE_SIZE, rather
5847 than TYPE_SIZE, issue a warning. There can be both false
5848 positives and false negatives from this warning in rare
5849 cases; to deal with all the possibilities would probably
5850 require performing both layout algorithms and comparing
5851 the results which is not particularly tractable. */
5853 && first_vbase
5854 && (tree_int_cst_lt
5859 bitsize_unit_node),
5862 "offset of virtual base %qT is not ABI-compliant and "
5864 basetype);
5867 }
5868 }
5869 }
5871 /* Returns the offset of the byte just past the end of the base class
5872 BINFO. */
5874 static tree
5876 {
5877 tree size;
5882 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5883 allocate some space for it. It cannot have virtual bases, so
5884 TYPE_SIZE_UNIT is fine. */
5886 else
5890 }
5892 /* Returns the offset of the byte just past the end of the base class
5893 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5894 only non-virtual bases are included. */
5896 static tree
5898 {
5901 tree binfo;
5902 tree base_binfo;
5903 tree offset;
5908 {
5918 }
5920 /* G++ 3.2 did not check indirect virtual bases. */
5924 {
5928 }
5931 }
5933 /* Warn about bases of T that are inaccessible because they are
5934 ambiguous. For example:
5936 struct S {};
5937 struct T : public S {};
5938 struct U : public S, public T {};
5940 Here, `(S*) new U' is not allowed because there are two `S'
5941 subobjects of U. */
5943 static void
5945 {
5948 tree basetype;
5949 tree binfo;
5950 tree base_binfo;
5952 /* If there are no repeated bases, nothing can be ambiguous. */
5956 /* Check direct bases. */
5959 {
5965 }
5967 /* Check for ambiguous virtual bases. */
5971 {
5977 }
5978 }
5980 /* Compare two INTEGER_CSTs K1 and K2. */
5982 static int
5984 {
5986 }
5988 /* Increase the size indicated in RLI to account for empty classes
5989 that are "off the end" of the class. */
5991 static void
5993 {
5994 tree eoc;
5995 tree rli_size;
5997 /* It might be the case that we grew the class to allocate a
5998 zero-sized base class. That won't be reflected in RLI, yet,
5999 because we are willing to overlay multiple bases at the same
6000 offset. However, now we need to make sure that RLI is big enough
6001 to reflect the entire class. */
6007 {
6009 /* In version 1 of the ABI, the size of a class that ends with
6010 a bitfield was not rounded up to a whole multiple of a
6011 byte. Because rli_size_unit_so_far returns only the number
6012 of fully allocated bytes, any extra bits were not included
6013 in the size. */
6015 else
6016 /* The size should have been rounded to a whole byte. */
6019 rli->bitpos
6028 }
6029 }
6031 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6032 BINFO_OFFSETs for all of the base-classes. Position the vtable
6033 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6035 static void
6037 {
6038 tree non_static_data_members;
6039 tree field;
6040 tree vptr;
6041 record_layout_info rli;
6042 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6043 types that appear at that offset. */
6044 splay_tree empty_base_offsets;
6045 /* True if the last field laid out was a bit-field. */
6047 /* The location at which the next field should be inserted. */
6049 /* T, as a base class. */
6050 tree base_t;
6052 /* Keep track of the first non-static data member. */
6055 /* Start laying out the record. */
6058 /* Mark all the primary bases in the hierarchy. */
6061 /* Create a pointer to our virtual function table. */
6064 /* The vptr is always the first thing in the class. */
6066 {
6071 }
6072 else
6075 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6080 /* Layout the non-static data members. */
6082 {
6083 tree type;
6084 tree padding;
6086 /* We still pass things that aren't non-static data members to
6087 the back end, in case it wants to do something with them. */
6089 {
6091 /* If the static data member has incomplete type, keep track
6092 of it so that it can be completed later. (The handling
6093 of pending statics in finish_record_layout is
6094 insufficient; consider:
6096 struct S1;
6097 struct S2 { static S1 s1; };
6099 At this point, finish_record_layout will be called, but
6100 S1 is still incomplete.) */
6102 {
6104 /* The visibility of static data members is determined
6105 at their point of declaration, not their point of
6106 definition. */
6108 }
6110 }
6118 /* If this field is a bit-field whose width is greater than its
6119 type, then there are some special rules for allocating
6120 it. */
6123 {
6125 tree integer_type;
6127 /* We must allocate the bits as if suitably aligned for the
6128 longest integer type that fits in this many bits. type
6129 of the field. Then, we are supposed to use the left over
6130 bits as additional padding. */
6139 /* ITK now indicates a type that is too large for the
6140 field. We have to back up by one to find the largest
6141 type that fits. */
6142 do
6143 {
6148 /* Figure out how much additional padding is required. GCC
6149 3.2 always created a padding field, even if it had zero
6150 width. */
6153 {
6155 /* In a union, the padding field must have the full width
6156 of the bit-field; all fields start at offset zero. */
6158 else
6159 {
6162 "ABI-compliant and may change in a future "
6164 t);
6167 }
6168 }
6169 #ifdef PCC_BITFIELD_TYPE_MATTERS
6170 /* An unnamed bitfield does not normally affect the
6171 alignment of the containing class on a target where
6172 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6173 make any exceptions for unnamed bitfields when the
6174 bitfields are longer than their types. Therefore, we
6175 temporarily give the field a name. */
6177 {
6180 }
6181 #endif
6186 empty_base_offsets);
6189 /* Now that layout has been performed, set the size of the
6190 field to the size of its declared type; the rest of the
6191 field is effectively invisible. */
6193 /* We must also reset the DECL_MODE of the field. */
6198 /* Versions of G++ before G++ 3.4 did not reset the
6199 DECL_MODE. */
6201 "the offset of %qD may not be ABI-compliant and may "
6203 }
6204 else
6206 empty_base_offsets);
6208 /* Remember the location of any empty classes in FIELD. */
6212 empty_base_offsets,
6215 /* If a bit-field does not immediately follow another bit-field,
6216 and yet it starts in the middle of a byte, we have failed to
6217 comply with the ABI. */
6220 /* The TREE_NO_WARNING flag gets set by Objective-C when
6221 laying out an Objective-C class. The ObjC ABI differs
6222 from the C++ ABI, and so we do not want a warning
6223 here. */
6225 && !last_field_was_bitfield
6228 bitsize_unit_node)))
6232 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6233 offset of the field. */
6240 "classes to be placed at different locations in a "
6243 /* The middle end uses the type of expressions to determine the
6244 possible range of expression values. In order to optimize
6245 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6246 must be made aware of the width of "i", via its type.
6248 Because C++ does not have integer types of arbitrary width,
6249 we must (for the purposes of the front end) convert from the
6250 type assigned here to the declared type of the bitfield
6251 whenever a bitfield expression is used as an rvalue.
6252 Similarly, when assigning a value to a bitfield, the value
6253 must be converted to the type given the bitfield here. */
6255 {
6260 {
6267 }
6268 }
6270 /* If we needed additional padding after this field, add it
6271 now. */
6273 {
6274 tree padding_field;
6277 FIELD_DECL,
6278 NULL_TREE,
6279 char_type_node);
6286 NULL_TREE,
6287 empty_base_offsets);
6288 }
6291 }
6294 {
6295 /* Make sure that we are on a byte boundary so that the size of
6296 the class without virtual bases will always be a round number
6297 of bytes. */
6300 }
6302 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6303 padding. */
6307 /* Delete all zero-width bit-fields from the list of fields. Now
6308 that the type is laid out they are no longer important. */
6311 /* Create the version of T used for virtual bases. We do not use
6312 make_class_type for this version; this is an artificial type. For
6313 a POD type, we just reuse T. */
6315 {
6318 /* Set the size and alignment for the new type. In G++ 3.2, all
6319 empty classes were considered to have size zero when used as
6320 base classes. */
6322 {
6327 "layout of classes derived from empty class %qT "
6329 t);
6330 }
6331 else
6332 {
6333 tree eoc;
6335 /* If the ABI version is not at least two, and the last
6336 field was a bit-field, RLI may not be on a byte
6337 boundary. In particular, rli_size_unit_so_far might
6338 indicate the last complete byte, while rli_size_so_far
6339 indicates the total number of bits used. Therefore,
6340 rli_size_so_far, rather than rli_size_unit_so_far, is
6341 used to compute TYPE_SIZE_UNIT. */
6349 eoc);
6356 }
6360 /* Copy the fields from T. */
6364 {
6366 FIELD_DECL,
6376 }
6378 /* Record the base version of the type. */
6381 }
6382 else
6385 /* Every empty class contains an empty class. */
6389 /* Set the TYPE_DECL for this type to contain the right
6390 value for DECL_OFFSET, so that we can use it as part
6391 of a COMPONENT_REF for multiple inheritance. */
6394 /* Now fix up any virtual base class types that we left lying
6395 around. We must get these done before we try to lay out the
6396 virtual function table. As a side-effect, this will remove the
6397 base subobject fields. */
6400 /* Make sure that empty classes are reflected in RLI at this
6401 point. */
6404 /* Make sure not to create any structures with zero size. */
6410 /* If this is a non-POD, declaring it packed makes a difference to how it
6411 can be used as a field; don't let finalize_record_size undo it. */
6415 /* Let the back end lay out the type. */
6424 /* Warn about bases that can't be talked about due to ambiguity. */
6427 /* Now that we're done with layout, give the base fields the real types. */
6432 /* Clean up. */
6439 }
6441 /* Determine the "key method" for the class type indicated by TYPE,
6442 and set CLASSTYPE_KEY_METHOD accordingly. */
6444 void
6446 {
6447 tree method;
6450 || processing_template_decl
6455 /* The key method is the first non-pure virtual function that is not
6456 inline at the point of class definition. On some targets the
6457 key function may not be inline; those targets should not call
6458 this function until the end of the translation unit. */
6464 {
6467 }
6470 }
6473 /* Allocate and return an instance of struct sorted_fields_type with
6474 N fields. */
6478 {
6485 }
6488 /* Perform processing required when the definition of T (a class type)
6489 is complete. */
6491 void
6493 {
6494 tree x;
6495 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6499 {
6504 }
6506 /* If this type was previously laid out as a forward reference,
6507 make sure we lay it out again. */
6511 /* Make assumptions about the class; we'll reset the flags if
6512 necessary. */
6518 /* Do end-of-class semantic processing: checking the validity of the
6519 bases and members and add implicitly generated methods. */
6522 /* Find the key method. */
6524 {
6525 /* The Itanium C++ ABI permits the key method to be chosen when
6526 the class is defined -- even though the key method so
6527 selected may later turn out to be an inline function. On
6528 some systems (such as ARM Symbian OS) the key method cannot
6529 be determined until the end of the translation unit. On such
6530 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6531 will cause the class to be added to KEYED_CLASSES. Then, in
6532 finish_file we will determine the key method. */
6536 /* If a polymorphic class has no key method, we may emit the vtable
6537 in every translation unit where the class definition appears. */
6540 }
6542 /* Layout the class itself. */
6545 /* We use the base type for trivial assignments, and hence it
6546 needs a mode. */
6551 /* If necessary, create the primary vtable for this class. */
6553 {
6554 /* We must enter these virtuals into the table. */
6558 /* Here we know enough to change the type of our virtual
6559 function table, but we will wait until later this function. */
6562 /* If we're warning about ABI tags, check the types of the new
6563 virtual functions. */
6567 }
6570 {
6572 tree fn;
6579 /* Add entries for virtual functions introduced by this class. */
6583 /* Set DECL_VINDEX for all functions declared in this class. */
6585 fn;
6587 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6589 {
6593 /* A thunk. We should never be calling this entry directly
6594 from this vtable -- we'd use the entry for the non
6595 thunk base function. */
6599 }
6600 }
6605 /* Complete the rtl for any static member objects of the type we're
6606 working on. */
6613 /* Done with FIELDS...now decide whether to sort these for
6614 faster lookups later.
6616 We use a small number because most searches fail (succeeding
6617 ultimately as the search bores through the inheritance
6618 hierarchy), and we want this failure to occur quickly. */
6622 /* Complain if one of the field types requires lower visibility. */
6625 /* Make the rtl for any new vtables we have created, and unmark
6626 the base types we marked. */
6629 /* Build the VTT for T. */
6632 /* This warning does not make sense for Java classes, since they
6633 cannot have destructors. */
6635 {
6636 tree dtor;
6640 if it were virtual, we would have created it by now. */
6641 !dtor
6650 "%q#T has virtual functions and accessible"
6652 }
6659 /* Class layout, assignment of virtual table slots, etc., is now
6660 complete. Give the back end a chance to tweak the visibility of
6661 the class or perform any other required target modifications. */
6671 /* Finish debugging output for this type. */
6675 {
6678 {
6681 }
6683 {
6686 else
6687 {
6690 }
6692 }
6694 {
6696 "the type of the first field has a different ABI from the "
6699 }
6700 }
6701 }
6703 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6704 equal to THRESHOLD or greater than THRESHOLD. */
6706 static void
6708 {
6711 {
6716 }
6717 }
6719 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6721 void
6723 {
6726 {
6728 int n_fields
6739 }
6740 }
6742 /* When T was built up, the member declarations were added in reverse
6743 order. Rearrange them to declaration order. */
6745 void
6747 {
6748 tree next;
6749 tree prev;
6750 tree x;
6752 /* The following lists are all in reverse order. Put them in
6753 declaration order now. */
6757 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6758 reverse order, so we can't just use nreverse. */
6763 {
6767 }
6769 {
6773 }
6774 }
6776 tree
6778 {
6781 /* Now that we've got all the field declarations, reverse everything
6782 as necessary. */
6787 /* Nadger the current location so that diagnostics point to the start of
6788 the struct, not the end. */
6792 {
6793 tree x;
6799 /* We need to emit an error message if this type was used as a parameter
6800 and it is an abstract type, even if it is a template. We construct
6801 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6802 account and we call complete_vars with this type, which will check
6803 the PARM_DECLS. Note that while the type is being defined,
6804 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6805 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6811 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6812 an enclosing scope is a template class, so that this function be
6813 found by lookup_fnfields_1 when the using declaration is not
6814 instantiated yet. */
6817 {
6822 }
6824 /* Remember current #pragma pack value. */
6827 /* Fix up any variants we've already built. */
6829 {
6834 }
6835 }
6836 else
6845 else
6849 /* Lambdas are defined by the LAMBDA_EXPR. */
6854 }
6855 \f
6856 /* Hash table to avoid endless recursion when handling references. */
6859 /* Return the dynamic type of INSTANCE, if known.
6860 Used to determine whether the virtual function table is needed
6861 or not.
6863 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6864 of our knowledge of its type. *NONNULL should be initialized
6865 before this function is called. */
6867 static tree
6869 {
6870 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6873 {
6877 else
6881 /* This is a call to a constructor, hence it's never zero. */
6883 {
6887 }
6891 /* This is a call to a constructor, hence it's never zero. */
6893 {
6897 }
6906 /* Propagate nonnull. */
6911 CASE_CONVERT:
6917 {
6918 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6919 with a real object -- given &p->f, p can still be null. */
6921 /* ??? Probably should check DECL_WEAK here. */
6924 }
6928 /* If this component is really a base class reference, then the field
6929 itself isn't definitive. */
6938 {
6942 }
6943 /* fall through... */
6948 {
6952 }
6954 {
6958 /* if we're in a ctor or dtor, we know our type. If
6959 current_class_ptr is set but we aren't in a function, we're in
6960 an NSDMI (and therefore a constructor). */
6965 {
6969 }
6970 }
6972 {
6973 /* We only need one hash table because it is always left empty. */
6977 /* Reference variables should be references to objects. */
6981 /* Enter the INSTANCE in a table to prevent recursion; a
6982 variable's initializer may refer to the variable
6983 itself. */
6988 {
6989 tree type;
6998 }
6999 }
7004 }
7005 #undef RECUR
7006 }
7008 /* Return nonzero if the dynamic type of INSTANCE is known, and
7009 equivalent to the static type. We also handle the case where
7010 INSTANCE is really a pointer. Return negative if this is a
7011 ctor/dtor. There the dynamic type is known, but this might not be
7012 the most derived base of the original object, and hence virtual
7013 bases may not be laid out according to this type.
7015 Used to determine whether the virtual function table is needed
7016 or not.
7018 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7019 of our knowledge of its type. *NONNULL should be initialized
7020 before this function is called. */
7022 int
7024 {
7027 tree fixed;
7029 /* processing_template_decl can be false in a template if we're in
7030 fold_non_dependent_expr, but we still want to suppress this check. */
7032 {
7033 /* In a template we only care about the type of the result. */
7037 }
7047 }
7049 \f
7050 void
7052 {
7055 current_class_stack
7063 }
7065 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7067 static void
7069 {
7070 tree type;
7072 /* We are re-entering the same class we just left, so we don't
7073 have to search the whole inheritance matrix to find all the
7074 decls to bind again. Instead, we install the cached
7075 class_shadowed list and walk through it binding names. */
7078 /* Restore IDENTIFIER_TYPE_VALUE. */
7080 type;
7083 }
7085 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7086 appropriate for TYPE.
7088 So that we may avoid calls to lookup_name, we cache the _TYPE
7089 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7091 For multiple inheritance, we perform a two-pass depth-first search
7092 of the type lattice. */
7094 void
7096 {
7097 class_stack_node_t csn;
7101 /* Make sure there is enough room for the new entry on the stack. */
7103 {
7105 current_class_stack
7107 current_class_stack_size);
7108 }
7110 /* Insert a new entry on the class stack. */
7117 current_class_depth++;
7119 /* Now set up the new type. */
7125 /* By default, things in classes are private, while things in
7126 structures or unions are public. */
7128 ? access_private_node
7134 {
7135 /* Forcibly remove any old class remnants. */
7137 }
7143 else
7145 }
7147 /* When we exit a toplevel class scope, we save its binding level so
7148 that we can restore it quickly. Here, we've entered some other
7149 class, so we must invalidate our cache. */
7151 void
7153 {
7155 }
7157 /* Get out of the current class scope. If we were in a class scope
7158 previously, that is the one popped to. */
7160 void
7162 {
7165 current_class_depth--;
7171 }
7173 /* Mark the top of the class stack as hidden. */
7175 void
7177 {
7180 }
7182 /* Mark the top of the class stack as un-hidden. */
7184 void
7186 {
7189 }
7191 /* Returns 1 if the class type currently being defined is either T or
7192 a nested type of T. */
7194 bool
7196 {
7204 /* We start looking from 1 because entry 0 is from global scope,
7205 and has no type. */
7207 {
7208 tree c;
7211 else
7212 {
7216 }
7221 }
7223 }
7225 /* If either current_class_type or one of its enclosing classes are derived
7226 from T, return the appropriate type. Used to determine how we found
7227 something via unqualified lookup. */
7229 tree
7231 {
7234 /* The bases of a dependent type are unknown. */
7245 {
7250 }
7253 }
7255 /* Returns the innermost class type which is not a lambda closure type. */
7257 tree
7259 {
7262 /* We start looking from 1 because entry 0 is from global scope,
7263 and has no type. */
7265 {
7266 tree c;
7269 else
7270 {
7274 }
7279 }
7281 }
7283 /* When entering a class scope, all enclosing class scopes' names with
7284 static meaning (static variables, static functions, types and
7285 enumerators) have to be visible. This recursive function calls
7286 pushclass for all enclosing class contexts until global or a local
7287 scope is reached. TYPE is the enclosed class. */
7289 void
7291 {
7292 /* A namespace might be passed in error cases, like A::B:C. */
7300 }
7302 /* Undoes a push_nested_class call. */
7304 void
7306 {
7312 }
7314 /* Returns the number of extern "LANG" blocks we are nested within. */
7316 int
7318 {
7320 }
7322 /* Set global variables CURRENT_LANG_NAME to appropriate value
7323 so that behavior of name-mangling machinery is correct. */
7325 void
7327 {
7331 {
7333 }
7335 {
7337 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7338 (See record_builtin_java_type in decl.c.) However, that causes
7339 incorrect debug entries if these types are actually used.
7340 So we re-enable debug output after extern "Java". */
7349 }
7351 {
7353 }
7354 else
7356 }
7358 /* Get out of the current language scope. */
7360 void
7362 {
7364 }
7365 \f
7366 /* Type instantiation routines. */
7368 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7369 matches the TARGET_TYPE. If there is no satisfactory match, return
7370 error_mark_node, and issue an error & warning messages under
7371 control of FLAGS. Permit pointers to member function if FLAGS
7372 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7373 a template-id, and EXPLICIT_TARGS are the explicitly provided
7374 template arguments.
7376 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7377 is the base path used to reference those member functions. If
7378 the address is resolved to a member function, access checks will be
7379 performed and errors issued if appropriate. */
7381 static tree
7383 tree overload,
7384 tsubst_flags_t flags,
7386 tree explicit_targs,
7387 tree access_path)
7388 {
7389 /* Here's what the standard says:
7391 [over.over]
7393 If the name is a function template, template argument deduction
7394 is done, and if the argument deduction succeeds, the deduced
7395 arguments are used to generate a single template function, which
7396 is added to the set of overloaded functions considered.
7398 Non-member functions and static member functions match targets of
7399 type "pointer-to-function" or "reference-to-function." Nonstatic
7400 member functions match targets of type "pointer-to-member
7401 function;" the function type of the pointer to member is used to
7402 select the member function from the set of overloaded member
7403 functions. If a nonstatic member function is selected, the
7404 reference to the overloaded function name is required to have the
7405 form of a pointer to member as described in 5.3.1.
7407 If more than one function is selected, any template functions in
7408 the set are eliminated if the set also contains a non-template
7409 function, and any given template function is eliminated if the
7410 set contains a second template function that is more specialized
7411 than the first according to the partial ordering rules 14.5.5.2.
7412 After such eliminations, if any, there shall remain exactly one
7413 selected function. */
7416 /* We store the matches in a TREE_LIST rooted here. The functions
7417 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7418 interoperability with most_specialized_instantiation. */
7420 tree fn;
7421 tree target_fn_type;
7423 /* By the time we get here, we should be seeing only real
7424 pointer-to-member types, not the internal POINTER_TYPE to
7425 METHOD_TYPE representation. */
7431 /* Check that the TARGET_TYPE is reasonable. */
7436 /* This is OK, too. */
7439 /* This is OK, too. This comes from a conversion to reference
7440 type. */
7442 else
7443 {
7449 }
7451 /* Non-member functions and static member functions match targets of type
7452 "pointer-to-function" or "reference-to-function." Nonstatic member
7453 functions match targets of type "pointer-to-member-function;" the
7454 function type of the pointer to member is used to select the member
7455 function from the set of overloaded member functions.
7457 So figure out the FUNCTION_TYPE that we want to match against. */
7460 /* If we can find a non-template function that matches, we can just
7461 use it. There's no point in generating template instantiations
7462 if we're just going to throw them out anyhow. But, of course, we
7463 can only do this when we don't *need* a template function. */
7465 {
7466 tree fns;
7469 {
7473 /* We're not looking for templates just yet. */
7478 /* We're looking for a non-static member, and this isn't
7479 one, or vice versa. */
7482 /* Ignore functions which haven't been explicitly
7483 declared. */
7487 /* See if there's a match. */
7490 }
7491 }
7493 /* Now, if we've already got a match (or matches), there's no need
7494 to proceed to the template functions. But, if we don't have a
7495 match we need to look at them, too. */
7497 {
7498 tree target_arg_types;
7499 tree target_ret_type;
7500 tree fns;
7503 tree arg;
7517 {
7519 tree instantiation;
7520 tree targs;
7523 /* We're only looking for templates. */
7528 /* We're not looking for a non-static member, and this is
7529 one, or vice versa. */
7534 /* If the template has a deduced return type, don't expose it to
7535 template argument deduction. */
7539 /* Try to do argument deduction. */
7546 /* Instantiation failed. */
7549 /* And now force instantiation to do return type deduction. */
7551 {
7557 }
7559 /* See if there's a match. */
7562 }
7564 /* Now, remove all but the most specialized of the matches. */
7566 {
7571 NULL_TREE,
7572 NULL_TREE);
7573 }
7574 }
7576 /* Now we should have exactly one function in MATCHES. */
7578 {
7579 /* There were *no* matches. */
7581 {
7584 target_type);
7587 }
7589 }
7591 {
7592 /* There were too many matches. First check if they're all
7593 the same function. */
7598 /* For multi-versioned functions, more than one match is just fine and
7599 decls_match will return false as they are different. */
7607 {
7609 {
7612 target_type);
7614 /* Since print_candidates expects the functions in the
7615 TREE_VALUE slot, we flip them here. */
7620 }
7623 }
7624 }
7626 /* Good, exactly one match. Now, convert it to the correct type. */
7631 {
7639 {
7642 }
7643 }
7645 /* If a pointer to a function that is multi-versioned is requested, the
7646 pointer to the dispatcher function is returned instead. This works
7647 well because indirectly calling the function will dispatch the right
7648 function version at run-time. */
7650 {
7654 /* Mark all the versions corresponding to the dispatcher as used. */
7657 }
7659 /* If we're doing overload resolution purely for the purpose of
7660 determining conversion sequences, we should not consider the
7661 function used. If this conversion sequence is selected, the
7662 function will be marked as used at this point. */
7664 {
7665 /* Make =delete work with SFINAE. */
7670 }
7672 /* We could not check access to member functions when this
7673 expression was originally created since we did not know at that
7674 time to which function the expression referred. */
7676 {
7679 }
7683 else
7684 {
7685 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7686 will mark the function as addressed, but here we must do it
7687 explicitly. */
7691 }
7692 }
7694 /* This function will instantiate the type of the expression given in
7695 RHS to match the type of LHSTYPE. If errors exist, then return
7696 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7697 we complain on errors. If we are not complaining, never modify rhs,
7698 as overload resolution wants to try many possible instantiations, in
7699 the hope that at least one will work.
7701 For non-recursive calls, LHSTYPE should be a function, pointer to
7702 function, or a pointer to member function. */
7704 tree
7706 {
7713 {
7717 }
7720 {
7727 /* Microsoft allows `A::f' to be resolved to a
7728 pointer-to-member. */
7729 ;
7730 else
7731 {
7736 }
7737 }
7740 {
7743 }
7745 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7746 deduce any type information. */
7748 {
7752 }
7754 /* There only a few kinds of expressions that may have a type
7755 dependent on overload resolution. */
7761 /* This should really only be used when attempting to distinguish
7762 what sort of a pointer to function we have. For now, any
7763 arithmetic operation which is not supported on pointers
7764 is rejected as an error. */
7767 {
7769 {
7775 /* Do not lose object's side effects. */
7779 }
7786 /* This can happen if we are forming a pointer-to-member for a
7787 member template. */
7790 /* Fall through. */
7793 {
7797 return
7801 }
7805 return
7809 access_path);
7812 {
7817 }
7824 }
7826 }
7827 \f
7828 /* Return the name of the virtual function pointer field
7829 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7830 this may have to look back through base types to find the
7831 ultimate field name. (For single inheritance, these could
7832 all be the same name. Who knows for multiple inheritance). */
7834 static tree
7836 {
7843 {
7849 }
7857 }
7859 void
7861 {
7868 {
7873 }
7874 }
7876 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7877 according to [class]:
7878 The class-name is also inserted
7879 into the scope of the class itself. For purposes of access checking,
7880 the inserted class name is treated as if it were a public member name. */
7882 void
7884 {
7887 tree saved_cas;
7902 }
7904 /* Returns 1 if TYPE contains only padding bytes. */
7906 int
7908 {
7915 /* In G++ 3.2, whether or not a class was empty was determined by
7916 looking at its size. */
7919 else
7921 }
7923 /* Returns true if TYPE contains an empty class. */
7925 static bool
7927 {
7931 {
7932 tree field;
7933 tree binfo;
7934 tree base_binfo;
7946 }
7950 }
7952 /* Returns true if TYPE contains no actual data, just various
7953 possible combinations of empty classes and possibly a vptr. */
7955 bool
7957 {
7959 {
7960 tree field;
7961 tree binfo;
7962 tree base_binfo;
7965 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7966 out, but we'd like to be able to check this before then. */
7980 }
7984 }
7986 /* Note that NAME was looked up while the current class was being
7987 defined and that the result of that lookup was DECL. */
7989 void
7991 {
7992 splay_tree names_used;
7994 /* If we're not defining a class, there's nothing to do. */
8000 /* If there's already a binding for this NAME, then we don't have
8001 anything to worry about. */
8014 }
8016 /* Note that NAME was declared (as DECL) in the current class. Check
8017 to see that the declaration is valid. */
8019 void
8021 {
8022 splay_tree names_used;
8023 splay_tree_node n;
8025 /* Look to see if we ever used this name. */
8026 names_used
8030 /* The C language allows members to be declared with a type of the same
8031 name, and the C++ standard says this diagnostic is not required. So
8032 allow it in extern "C" blocks unless predantic is specified.
8033 Allow it in all cases if -ms-extensions is specified. */
8039 {
8040 /* [basic.scope.class]
8042 A name N used in a class S shall refer to the same declaration
8043 in its context and when re-evaluated in the completed scope of
8044 S. */
8048 }
8049 }
8051 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8052 Secondary vtables are merged with primary vtables; this function
8053 will return the VAR_DECL for the primary vtable. */
8055 tree
8057 {
8058 tree decl;
8062 {
8065 }
8069 }
8072 /* Returns the binfo for the primary base of BINFO. If the resulting
8073 BINFO is a virtual base, and it is inherited elsewhere in the
8074 hierarchy, then the returned binfo might not be the primary base of
8075 BINFO in the complete object. Check BINFO_PRIMARY_P or
8076 BINFO_LOST_PRIMARY_P to be sure. */
8078 static tree
8080 {
8081 tree primary_base;
8088 }
8090 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8092 static int
8094 {
8098 }
8100 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8101 INDENT should be zero when called from the top level; it is
8102 incremented recursively. IGO indicates the next expected BINFO in
8103 inheritance graph ordering. */
8105 static tree
8108 tree binfo,
8109 tree igo,
8111 {
8113 tree base_binfo;
8121 {
8124 }
8139 {
8143 TFF_PLAIN_IDENTIFIER),
8145 }
8147 {
8150 }
8155 {
8159 {
8163 TFF_PLAIN_IDENTIFIER));
8164 }
8166 {
8170 TFF_PLAIN_IDENTIFIER));
8171 }
8173 {
8177 TFF_PLAIN_IDENTIFIER));
8178 }
8180 {
8184 TFF_PLAIN_IDENTIFIER));
8185 }
8189 }
8195 }
8197 /* Dump the BINFO hierarchy for T. */
8199 static void
8201 {
8213 }
8215 /* Debug interface to hierarchy dumping. */
8217 void
8219 {
8221 }
8223 static void
8225 {
8230 {
8233 }
8234 }
8236 static void
8238 {
8239 tree value;
8241 HOST_WIDE_INT elt;
8249 TFF_PLAIN_IDENTIFIER));
8256 }
8258 static void
8260 {
8268 {
8275 {
8280 }
8284 }
8287 }
8289 static void
8291 {
8299 {
8304 }
8307 }
8309 /* Dump a function or thunk and its thunkees. */
8311 static void
8313 {
8316 tree thunks;
8324 {
8334 else
8340 }
8344 }
8346 /* Dump the thunks for FN. */
8348 void
8350 {
8352 }
8354 /* Virtual function table initialization. */
8356 /* Create all the necessary vtables for T and its base classes. */
8358 static void
8360 {
8361 tree vbase;
8365 /* We lay out the primary and secondary vtables in one contiguous
8366 vtable. The primary vtable is first, followed by the non-virtual
8367 secondary vtables in inheritance graph order. */
8371 /* Then come the virtual bases, also in inheritance graph order. */
8373 {
8377 }
8381 }
8383 /* Initialize the vtable for BINFO with the INITS. */
8385 static void
8387 {
8388 tree decl;
8394 }
8396 /* Build the VTT (virtual table table) for T.
8397 A class requires a VTT if it has virtual bases.
8399 This holds
8400 1 - primary virtual pointer for complete object T
8401 2 - secondary VTTs for each direct non-virtual base of T which requires a
8402 VTT
8403 3 - secondary virtual pointers for each direct or indirect base of T which
8404 has virtual bases or is reachable via a virtual path from T.
8405 4 - secondary VTTs for each direct or indirect virtual base of T.
8407 Secondary VTTs look like complete object VTTs without part 4. */
8409 static void
8411 {
8412 tree type;
8413 tree vtt;
8414 tree index;
8417 /* Build up the initializers for the VTT. */
8422 /* If we didn't need a VTT, we're done. */
8426 /* Figure out the type of the VTT. */
8430 /* Now, build the VTT object itself. */
8433 /* Add the VTT to the vtables list. */
8438 }
8440 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8441 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8442 and CHAIN the vtable pointer for this binfo after construction is
8443 complete. VALUE can also be another BINFO, in which case we recurse. */
8445 static tree
8447 {
8448 tree vt;
8451 {
8457 else
8459 }
8462 }
8464 /* Data for secondary VTT initialization. */
8466 {
8467 /* Is this the primary VTT? */
8470 /* Current index into the VTT. */
8471 tree index;
8473 /* Vector of initializers built up. */
8476 /* The type being constructed by this secondary VTT. */
8477 tree type_being_constructed;
8480 /* Recursively build the VTT-initializer for BINFO (which is in the
8481 hierarchy dominated by T). INITS points to the end of the initializer
8482 list to date. INDEX is the VTT index where the next element will be
8483 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8484 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8485 for virtual bases of T. When it is not so, we build the constructor
8486 vtables for the BINFO-in-T variant. */
8488 static void
8491 {
8493 tree b;
8494 tree init;
8495 secondary_vptr_vtt_init_data data;
8498 /* We only need VTTs for subobjects with virtual bases. */
8502 /* We need to use a construction vtable if this is not the primary
8503 VTT. */
8505 {
8508 /* Record the offset in the VTT where this sub-VTT can be found. */
8510 }
8512 /* Add the address of the primary vtable for the complete object. */
8516 {
8519 }
8522 /* Recursively add the secondary VTTs for non-virtual bases. */
8527 /* Add secondary virtual pointers for all subobjects of BINFO with
8528 either virtual bases or reachable along a virtual path, except
8529 subobjects that are non-virtual primary bases. */
8539 /* data.inits might have grown as we added secondary virtual pointers.
8540 Make sure our caller knows about the new vector. */
8544 /* Add the secondary VTTs for virtual bases in inheritance graph
8545 order. */
8547 {
8552 }
8553 else
8554 /* Remove the ctor vtables we created. */
8556 }
8558 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8559 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8561 static tree
8563 {
8566 /* We don't care about bases that don't have vtables. */
8570 /* We're only interested in proper subobjects of the type being
8571 constructed. */
8575 /* We're only interested in bases with virtual bases or reachable
8576 via a virtual path from the type being constructed. */
8581 /* We're not interested in non-virtual primary bases. */
8585 /* Record the index where this secondary vptr can be found. */
8587 {
8592 {
8593 /* It's a primary virtual base, and this is not a
8594 construction vtable. Find the base this is primary of in
8595 the inheritance graph, and use that base's vtable
8596 now. */
8599 }
8600 }
8602 /* Add the initializer for the secondary vptr itself. */
8605 /* Advance the vtt index. */
8610 }
8612 /* Called from build_vtt_inits via dfs_walk. After building
8613 constructor vtables and generating the sub-vtt from them, we need
8614 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8615 binfo of the base whose sub vtt was generated. */
8617 static tree
8619 {
8623 /* If this class has no vtable, none of its bases do. */
8627 /* This might be a primary base, so have no vtable in this
8628 hierarchy. */
8631 /* If we scribbled the construction vtable vptr into BINFO, clear it
8632 out now. */
8638 }
8640 /* Build the construction vtable group for BINFO which is in the
8641 hierarchy dominated by T. */
8643 static void
8645 {
8646 tree type;
8647 tree vtbl;
8648 tree id;
8649 tree vbase;
8652 /* See if we've already created this construction vtable group. */
8658 /* Build a version of VTBL (with the wrong type) for use in
8659 constructing the addresses of secondary vtables in the
8660 construction vtable group. */
8663 /* Don't export construction vtables from shared libraries. Even on
8664 targets that don't support hidden visibility, this tells
8665 can_refer_decl_in_current_unit_p not to assume that it's safe to
8666 access from a different compilation unit (bz 54314). */
8674 /* Add the vtables for each of our virtual bases using the vbase in T
8675 binfo. */
8677 vbase;
8679 {
8680 tree b;
8687 }
8689 /* Figure out the type of the construction vtable. */
8696 /* Initialize the construction vtable. */
8700 }
8702 /* Add the vtbl initializers for BINFO (and its bases other than
8703 non-virtual primaries) to the list of INITS. BINFO is in the
8704 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8705 the constructor the vtbl inits should be accumulated for. (If this
8706 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8707 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8708 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8709 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8710 but are not necessarily the same in terms of layout. */
8712 static void
8714 tree orig_binfo,
8715 tree rtti_binfo,
8716 tree vtbl,
8717 tree t,
8719 {
8721 tree base_binfo;
8726 /* If it doesn't have a vptr, we don't do anything. */
8730 /* If we're building a construction vtable, we're not interested in
8731 subobjects that don't require construction vtables. */
8737 /* Build the initializers for the BINFO-in-T vtable. */
8740 /* Walk the BINFO and its bases. We walk in preorder so that as we
8741 initialize each vtable we can figure out at what offset the
8742 secondary vtable lies from the primary vtable. We can't use
8743 dfs_walk here because we need to iterate through bases of BINFO
8744 and RTTI_BINFO simultaneously. */
8746 {
8747 /* Skip virtual bases. */
8753 inits);
8754 }
8755 }
8757 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8758 BINFO vtable to L. */
8760 static void
8762 tree orig_binfo,
8763 tree rtti_binfo,
8764 tree orig_vtbl,
8765 tree t,
8767 {
8774 {
8775 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8776 primary virtual base. If it is not the same primary in
8777 the hierarchy of T, we'll need to generate a ctor vtable
8778 for it, to place at its location in T. If it is the same
8779 primary, we still need a VTT entry for the vtable, but it
8780 should point to the ctor vtable for the base it is a
8781 primary for within the sub-hierarchy of RTTI_BINFO.
8783 There are three possible cases:
8785 1) We are in the same place.
8786 2) We are a primary base within a lost primary virtual base of
8787 RTTI_BINFO.
8788 3) We are primary to something not a base of RTTI_BINFO. */
8790 tree b;
8793 /* First, look through the bases we are primary to for RTTI_BINFO
8794 or a virtual base. */
8797 {
8802 }
8803 /* If we run out of primary links, keep looking down our
8804 inheritance chain; we might be an indirect primary. */
8808 found:
8810 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8811 base B and it is a base of RTTI_BINFO, this is case 2. In
8812 either case, we share our vtable with LAST, i.e. the
8813 derived-most base within B of which we are a primary. */
8816 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8817 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8818 binfo_ctor_vtable after everything's been set up. */
8821 /* Otherwise, this is case 3 and we get our own. */
8822 }
8829 {
8830 tree index;
8833 /* Add the initializer for this vtable. */
8837 /* Figure out the position to which the VPTR should point. */
8843 }
8846 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8847 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8848 straighten this out. */
8851 /* Throw away any unneeded intializers. */
8853 else
8854 /* For an ordinary vtable, set BINFO_VTABLE. */
8856 }
8860 /* Construct the initializer for BINFO's virtual function table. BINFO
8861 is part of the hierarchy dominated by T. If we're building a
8862 construction vtable, the ORIG_BINFO is the binfo we should use to
8863 find the actual function pointers to put in the vtable - but they
8864 can be overridden on the path to most-derived in the graph that
8865 ORIG_BINFO belongs. Otherwise,
8866 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8867 BINFO that should be indicated by the RTTI information in the
8868 vtable; it will be a base class of T, rather than T itself, if we
8869 are building a construction vtable.
8871 The value returned is a TREE_LIST suitable for wrapping in a
8872 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8873 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8874 number of non-function entries in the vtable.
8876 It might seem that this function should never be called with a
8877 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8878 base is always subsumed by a derived class vtable. However, when
8879 we are building construction vtables, we do build vtables for
8880 primary bases; we need these while the primary base is being
8881 constructed. */
8883 static void
8885 tree orig_binfo,
8886 tree t,
8887 tree rtti_binfo,
8890 {
8891 tree v;
8892 vtbl_init_data vid;
8894 tree vbinfo;
8898 /* Initialize VID. */
8906 /* The first vbase or vcall offset is at index -3 in the vtable. */
8909 /* Add entries to the vtable for RTTI. */
8912 /* Create an array for keeping track of the functions we've
8913 processed. When we see multiple functions with the same
8914 signature, we share the vcall offsets. */
8916 /* Add the vcall and vbase offset entries. */
8919 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8920 build_vbase_offset_vtbl_entries. */
8925 /* If the target requires padding between data entries, add that now. */
8927 {
8932 /* Move data entries into their new positions and add padding
8933 after the new positions. Iterate backwards so we don't
8934 overwrite entries that we would need to process later. */
8937 ix--)
8938 {
8946 {
8950 null_pointer_node);
8951 }
8952 }
8953 }
8958 /* The initializers for virtual functions were built up in reverse
8959 order. Straighten them out and add them to the running list in one
8960 step. */
8969 /* Go through all the ordinary virtual functions, building up
8970 initializers. */
8972 {
8973 tree delta;
8974 tree vcall_index;
8981 {
8985 {
8988 }
8990 }
8992 /* If the only definition of this function signature along our
8993 primary base chain is from a lost primary, this vtable slot will
8994 never be used, so just zero it out. This is important to avoid
8995 requiring extra thunks which cannot be generated with the function.
8997 We first check this in update_vtable_entry_for_fn, so we handle
8998 restored primary bases properly; we also need to do it here so we
8999 zero out unused slots in ctor vtables, rather than filling them
9000 with erroneous values (though harmless, apart from relocation
9001 costs). */
9006 {
9007 /* Pull the offset for `this', and the function to call, out of
9008 the list. */
9015 /* You can't call an abstract virtual function; it's abstract.
9016 So, we replace these functions with __pure_virtual. */
9018 {
9021 {
9023 abort_fndecl_addr
9027 }
9028 }
9029 /* Likewise for deleted virtuals. */
9031 {
9040 }
9041 else
9042 {
9044 {
9048 }
9049 /* Take the address of the function, considering it to be of an
9050 appropriate generic type. */
9054 }
9055 }
9057 /* And add it to the chain of initializers. */
9059 {
9064 else
9066 {
9072 }
9073 }
9074 else
9076 }
9077 }
9079 /* Adds to vid->inits the initializers for the vbase and vcall
9080 offsets in BINFO, which is in the hierarchy dominated by T. */
9082 static void
9084 {
9085 tree b;
9087 /* If this is a derived class, we must first create entries
9088 corresponding to the primary base class. */
9093 /* Add the vbase entries for this base. */
9095 /* Add the vcall entries for this base. */
9097 }
9099 /* Returns the initializers for the vbase offset entries in the vtable
9100 for BINFO (which is part of the class hierarchy dominated by T), in
9101 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9102 where the next vbase offset will go. */
9104 static void
9106 {
9107 tree vbase;
9108 tree t;
9109 tree non_primary_binfo;
9111 /* If there are no virtual baseclasses, then there is nothing to
9112 do. */
9118 /* We might be a primary base class. Go up the inheritance hierarchy
9119 until we find the most derived class of which we are a primary base:
9120 it is the offset of that which we need to use. */
9123 {
9124 tree b;
9126 /* If we have reached a virtual base, then it must be a primary
9127 base (possibly multi-level) of vid->binfo, or we wouldn't
9128 have called build_vcall_and_vbase_vtbl_entries for it. But it
9129 might be a lost primary, so just skip down to vid->binfo. */
9131 {
9134 }
9140 }
9142 /* Go through the virtual bases, adding the offsets. */
9144 vbase;
9146 {
9147 tree b;
9148 tree delta;
9153 /* Find the instance of this virtual base in the complete
9154 object. */
9157 /* If we've already got an offset for this virtual base, we
9158 don't need another one. */
9163 /* Figure out where we can find this vbase offset. */
9172 /* The vbase offset had better be the same. */
9175 /* The next vbase will come at a more negative offset. */
9179 /* The initializer is the delta from BINFO to this virtual base.
9180 The vbase offsets go in reverse inheritance-graph order, and
9181 we are walking in inheritance graph order so these end up in
9182 the right order. */
9189 }
9190 }
9192 /* Adds the initializers for the vcall offset entries in the vtable
9193 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9194 to VID->INITS. */
9196 static void
9198 {
9199 /* We only need these entries if this base is a virtual base. We
9200 compute the indices -- but do not add to the vtable -- when
9201 building the main vtable for a class. */
9204 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9205 correspond to VID->DERIVED), we are building a primary
9206 construction virtual table. Since this is a primary
9207 virtual table, we do not need the vcall offsets for
9208 BINFO. */
9210 {
9211 /* We need a vcall offset for each of the virtual functions in this
9212 vtable. For example:
9214 class A { virtual void f (); };
9215 class B1 : virtual public A { virtual void f (); };
9216 class B2 : virtual public A { virtual void f (); };
9217 class C: public B1, public B2 { virtual void f (); };
9219 A C object has a primary base of B1, which has a primary base of A. A
9220 C also has a secondary base of B2, which no longer has a primary base
9221 of A. So the B2-in-C construction vtable needs a secondary vtable for
9222 A, which will adjust the A* to a B2* to call f. We have no way of
9223 knowing what (or even whether) this offset will be when we define B2,
9224 so we store this "vcall offset" in the A sub-vtable and look it up in
9225 a "virtual thunk" for B2::f.
9227 We need entries for all the functions in our primary vtable and
9228 in our non-virtual bases' secondary vtables. */
9230 /* If we are just computing the vcall indices -- but do not need
9231 the actual entries -- not that. */
9234 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9236 }
9237 }
9239 /* Build vcall offsets, starting with those for BINFO. */
9241 static void
9243 {
9245 tree primary_binfo;
9246 tree base_binfo;
9248 /* Don't walk into virtual bases -- except, of course, for the
9249 virtual base for which we are building vcall offsets. Any
9250 primary virtual base will have already had its offsets generated
9251 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9255 /* If BINFO has a primary base, process it first. */
9260 /* Add BINFO itself to the list. */
9263 /* Scan the non-primary bases of BINFO. */
9267 }
9269 /* Called from build_vcall_offset_vtbl_entries_r. */
9271 static void
9273 {
9274 /* Make entries for the rest of the virtuals. */
9276 {
9277 tree orig_fn;
9279 /* The ABI requires that the methods be processed in declaration
9280 order. G++ 3.2 used the order in the vtable. */
9282 orig_fn;
9286 }
9287 else
9288 {
9289 tree derived_virtuals;
9290 tree base_virtuals;
9291 tree orig_virtuals;
9292 /* If BINFO is a primary base, the most derived class which has
9293 BINFO as a primary base; otherwise, just BINFO. */
9294 tree non_primary_binfo;
9296 /* We might be a primary base class. Go up the inheritance hierarchy
9297 until we find the most derived class of which we are a primary base:
9298 it is the BINFO_VIRTUALS there that we need to consider. */
9301 {
9302 tree b;
9304 /* If we have reached a virtual base, then it must be vid->vbase,
9305 because we ignore other virtual bases in
9306 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9307 base (possibly multi-level) of vid->binfo, or we wouldn't
9308 have called build_vcall_and_vbase_vtbl_entries for it. But it
9309 might be a lost primary, so just skip down to vid->binfo. */
9311 {
9315 }
9321 }
9324 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9325 where rtti_binfo is the most derived type. */
9326 non_primary_binfo
9332 base_virtuals;
9336 {
9337 tree orig_fn;
9339 /* Find the declaration that originally caused this function to
9340 be present in BINFO_TYPE (binfo). */
9343 /* When processing BINFO, we only want to generate vcall slots for
9344 function slots introduced in BINFO. So don't try to generate
9345 one if the function isn't even defined in BINFO. */
9350 }
9351 }
9352 }
9354 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9356 static void
9358 {
9360 tree vcall_offset;
9361 tree derived_entry;
9363 /* If there is already an entry for a function with the same
9364 signature as FN, then we do not need a second vcall offset.
9365 Check the list of functions already present in the derived
9366 class vtable. */
9368 {
9370 /* We only use one vcall offset for virtual destructors,
9371 even though there are two virtual table entries. */
9375 }
9377 /* If we are building these vcall offsets as part of building
9378 the vtable for the most derived class, remember the vcall
9379 offset. */
9381 {
9384 }
9386 /* The next vcall offset will be found at a more negative
9387 offset. */
9391 /* Keep track of this function. */
9395 {
9396 tree base;
9397 tree fn;
9399 /* Find the overriding function. */
9403 else
9404 {
9407 /* The vbase we're working on is a primary base of
9408 vid->binfo. But it might be a lost primary, so its
9409 BINFO_OFFSET might be wrong, so we just use the
9410 BINFO_OFFSET from vid->binfo. */
9416 vcall_offset);
9417 }
9418 /* Add the initializer to the vtable. */
9420 }
9421 }
9423 /* Return vtbl initializers for the RTTI entries corresponding to the
9424 BINFO's vtable. The RTTI entries should indicate the object given
9425 by VID->rtti_binfo. */
9427 static void
9429 {
9430 tree b;
9431 tree t;
9432 tree offset;
9433 tree decl;
9434 tree init;
9438 /* To find the complete object, we will first convert to our most
9439 primary base, and then add the offset in the vtbl to that value. */
9443 {
9444 tree primary_base;
9450 }
9454 /* The second entry is the address of the typeinfo object. */
9457 else
9460 /* Convert the declaration to a type that can be stored in the
9461 vtable. */
9465 /* Add the offset-to-top entry. It comes earlier in the vtable than
9466 the typeinfo entry. Convert the offset to look like a
9467 function pointer, so that we can put it in the vtable. */
9470 }
9472 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9473 accessibility. */
9475 bool
9477 {
9480 }
9482 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9484 bool
9486 {
9490 }
9492 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9493 class between them, if any. */
9495 tree
9497 {
9509 {
9512 }
9516 }