| blob | 0c3ce47bc756be930d768cdc2d8b5b423285fde7 |
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),
438 v_offset);
450 /* Negative fixed_type_p means this is a constructor or destructor;
451 virtual base layout is fixed in in-charge [cd]tors, but not in
452 base [cd]tors. */
456 v_offset,
459 else
461 }
469 {
474 }
475 else
481 out:
487 }
489 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
490 Perform a derived-to-base conversion by recursively building up a
491 sequence of COMPONENT_REFs to the appropriate base fields. */
493 static tree
495 {
498 tree field;
501 {
502 tree temp;
506 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
507 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
508 an lvalue in the front end; only _DECLs and _REFs are lvalues
509 in the back end. */
515 }
517 /* Recurse. */
522 /* Is this the base field created by build_base_field? */
526 /* If we're looking for a field in the most-derived class,
527 also check the field offset; we can have two base fields
528 of the same type if one is an indirect virtual base and one
529 is a direct non-virtual base. */
533 {
534 /* We don't use build_class_member_access_expr here, as that
535 has unnecessary checks, and more importantly results in
536 recursive calls to dfs_walk_once. */
544 /* Mark the expression const or volatile, as appropriate.
545 Even though we've dealt with the type above, we still have
546 to mark the expression itself. */
553 }
555 /* Didn't find the base field?!? */
557 }
559 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
560 type is a class type or a pointer to a class type. In the former
561 case, TYPE is also a class type; in the latter it is another
562 pointer type. If CHECK_ACCESS is true, an error message is emitted
563 if TYPE is inaccessible. If OBJECT has pointer type, the value is
564 assumed to be non-NULL. */
566 tree
568 tsubst_flags_t complain)
569 {
570 tree binfo;
571 tree object_type;
574 {
577 }
578 else
587 }
589 /* EXPR is an expression with unqualified class type. BASE is a base
590 binfo of that class type. Returns EXPR, converted to the BASE
591 type. This function assumes that EXPR is the most derived class;
592 therefore virtual bases can be found at their static offsets. */
594 tree
596 {
597 tree expr_type;
601 {
602 /* If this is a non-empty base, use a COMPONENT_REF. */
606 /* We use fold_build2 and fold_convert below to simplify the trees
607 provided to the optimizers. It is not safe to call these functions
608 when processing a template because they do not handle C++-specific
609 trees. */
617 }
620 }
622 \f
623 tree
625 {
631 /* First, convert to the requested type. */
636 /* Second, the requested type may not be the owner of its own vptr.
637 If not, convert to the base class that owns it. We cannot use
638 convert_to_base here, because VCONTEXT may appear more than once
639 in the inheritance hierarchy of TYPE, and thus direct conversion
640 between the types may be ambiguous. Following the path back up
641 one step at a time via primary bases avoids the problem. */
645 {
648 }
651 }
653 /* Given an object INSTANCE, return an expression which yields the
654 vtable element corresponding to INDEX. There are many special
655 cases for INSTANCE which we take care of here, mainly to avoid
656 creating extra tree nodes when we don't have to. */
658 static tree
660 {
661 tree aref;
664 /* Try to figure out what a reference refers to, and
665 access its virtual function table directly. */
673 {
678 }
687 }
689 tree
691 {
695 }
697 /* Given a stable object pointer INSTANCE_PTR, return an expression which
698 yields a function pointer corresponding to vtable element INDEX. */
700 tree
702 {
703 tree aref;
706 tf_warning_or_error),
707 idx);
709 /* When using function descriptors, the address of the
710 vtable entry is treated as a function pointer. */
715 /* Remember this as a method reference, for later devirtualization. */
719 }
721 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
722 for the given TYPE. */
724 static tree
726 {
728 }
730 /* DECL is an entity associated with TYPE, like a virtual table or an
731 implicitly generated constructor. Determine whether or not DECL
732 should have external or internal linkage at the object file
733 level. This routine does not deal with COMDAT linkage and other
734 similar complexities; it simply sets TREE_PUBLIC if it possible for
735 entities in other translation units to contain copies of DECL, in
736 the abstract. */
738 void
740 {
743 }
745 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
746 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
747 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
749 static tree
751 {
752 tree decl;
755 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
756 now to avoid confusion in mangle_decl. */
765 /* At one time the vtable info was grabbed 2 words at a time. This
766 fails on sparc unless you have 8-byte alignment. (tiemann) */
770 /* The vtable has not been defined -- yet. */
774 /* Mark the VAR_DECL node representing the vtable itself as a
775 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
776 is rather important that such things be ignored because any
777 effort to actually generate DWARF for them will run into
778 trouble when/if we encounter code like:
780 #pragma interface
781 struct S { virtual void member (); };
783 because the artificial declaration of the vtable itself (as
784 manufactured by the g++ front end) will say that the vtable is
785 a static member of `S' but only *after* the debug output for
786 the definition of `S' has already been output. This causes
787 grief because the DWARF entry for the definition of the vtable
788 will try to refer back to an earlier *declaration* of the
789 vtable as a static member of `S' and there won't be one. We
790 might be able to arrange to have the "vtable static member"
791 attached to the member list for `S' before the debug info for
792 `S' get written (which would solve the problem) but that would
793 require more intrusive changes to the g++ front end. */
797 }
799 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
800 or even complete. If this does not exist, create it. If COMPLETE is
801 nonzero, then complete the definition of it -- that will render it
802 impossible to actually build the vtable, but is useful to get at those
803 which are known to exist in the runtime. */
805 tree
807 {
808 tree decl;
817 {
820 }
823 }
825 /* Build the primary virtual function table for TYPE. If BINFO is
826 non-NULL, build the vtable starting with the initial approximation
827 that it is the same as the one which is the head of the association
828 list. Returns a nonzero value if a new vtable is actually
829 created. */
831 static int
833 {
834 tree decl;
835 tree virtuals;
840 {
842 /* We have already created a vtable for this base, so there's
843 no need to do it again. */
850 }
851 else
852 {
855 }
858 {
861 }
863 /* Initialize the association list for this type, based
864 on our first approximation. */
869 }
871 /* Give BINFO a new virtual function table which is initialized
872 with a skeleton-copy of its original initialization. The only
873 entry that changes is the `delta' entry, so we can really
874 share a lot of structure.
876 FOR_TYPE is the most derived type which caused this table to
877 be needed.
879 Returns nonzero if we haven't met BINFO before.
881 The order in which vtables are built (by calling this function) for
882 an object must remain the same, otherwise a binary incompatibility
883 can result. */
885 static int
887 {
889 /* We already created a vtable for this base. There's no need to
890 do it again. */
893 /* Remember that we've created a vtable for this BINFO, so that we
894 don't try to do so again. */
897 /* Make fresh virtual list, so we can smash it later. */
900 /* Secondary vtables are laid out as part of the same structure as
901 the primary vtable. */
904 }
906 /* Create a new vtable for BINFO which is the hierarchy dominated by
907 T. Return nonzero if we actually created a new vtable. */
909 static int
911 {
913 /* In this case, it is *type*'s vtable we are modifying. We start
914 with the approximation that its vtable is that of the
915 immediate base class. */
917 else
918 /* This is our very own copy of `basetype' to play with. Later,
919 we will fill in all the virtual functions that override the
920 virtual functions in these base classes which are not defined
921 by the current type. */
923 }
925 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
926 (which is in the hierarchy dominated by T) list FNDECL as its
927 BV_FN. DELTA is the required constant adjustment from the `this'
928 pointer where the vtable entry appears to the `this' required when
929 the function is actually called. */
931 static void
933 tree binfo,
934 tree fndecl,
935 tree delta,
937 {
938 tree v;
944 {
945 /* We need a new vtable for BINFO. */
947 {
948 /* If we really did make a new vtable, we also made a copy
949 of the BINFO_VIRTUALS list. Now, we have to find the
950 corresponding entry in that list. */
955 }
960 }
961 }
963 \f
964 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
965 the USING_DECL naming METHOD. Returns true if the method could be
966 added to the method vec. */
968 bool
970 {
972 tree overload;
978 tree current_fns;
979 tree fns;
992 {
993 /* Make a new method vector. We start with 8 entries. We must
994 allocate at least two (for constructors and destructors), and
995 we're going to end up with an assignment operator at some
996 point as well. */
998 /* Create slots for constructors and destructors. */
1002 }
1004 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1007 /* Constructors and destructors go in special slots. */
1011 {
1015 {
1021 type);
1022 }
1023 }
1024 else
1025 {
1026 tree m;
1029 /* See if we already have an entry with this name. */
1033 {
1036 {
1041 }
1045 {
1048 }
1053 }
1054 }
1057 /* Check to see if we've already got this method. */
1059 {
1061 tree fn_type;
1062 tree method_type;
1063 tree parms1;
1064 tree parms2;
1069 /* [over.load] Member function declarations with the
1070 same name and the same parameter types cannot be
1071 overloaded if any of them is a static member
1072 function declaration.
1074 [over.load] Member function declarations with the same name and
1075 the same parameter-type-list as well as member function template
1076 declarations with the same name, the same parameter-type-list, and
1077 the same template parameter lists cannot be overloaded if any of
1078 them, but not all, have a ref-qualifier.
1080 [namespace.udecl] When a using-declaration brings names
1081 from a base class into a derived class scope, member
1082 functions in the derived class override and/or hide member
1083 functions with the same name and parameter types in a base
1084 class (rather than conflicting). */
1090 /* Compare the quals on the 'this' parm. Don't compare
1091 the whole types, as used functions are treated as
1092 coming from the using class in overload resolution. */
1095 /* Either both or neither need to be ref-qualified for
1096 differing quals to allow overloading. */
1103 /* For templates, the return type and template parameters
1104 must be identical. */
1121 {
1122 /* For function versions, their parms and types match
1123 but they are not duplicates. Record function versions
1124 as and when they are found. extern "C" functions are
1125 not treated as versions. */
1131 {
1132 /* Mark functions as versions if necessary. Modify the mangled
1133 decl name if necessary. */
1135 {
1139 }
1141 {
1145 }
1148 }
1150 {
1152 {
1159 }
1160 /* Otherwise defer to the other function. */
1162 }
1164 {
1166 /* Defer to the local function. */
1168 }
1169 else
1170 {
1173 }
1175 /* We don't call duplicate_decls here to merge the
1176 declarations because that will confuse things if the
1177 methods have inline definitions. In particular, we
1178 will crash while processing the definitions. */
1180 }
1181 }
1183 /* A class should never have more than one destructor. */
1187 /* Add the new binding. */
1189 {
1192 }
1193 else
1202 {
1205 /* We only expect to add few methods in the COMPLETE_P case, so
1206 just make room for one more method in that case. */
1209 else
1215 else
1217 }
1218 else
1219 /* Replace the current slot. */
1222 }
1224 /* Subroutines of finish_struct. */
1226 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1227 legit, otherwise return 0. */
1229 static int
1231 {
1232 tree elem;
1241 {
1243 {
1247 else
1250 }
1251 else
1252 {
1253 /* They're changing the access to the same thing they changed
1254 it to before. That's OK. */
1255 ;
1256 }
1257 }
1258 else
1259 {
1261 tf_warning_or_error);
1264 }
1266 }
1268 /* Process the USING_DECL, which is a member of T. */
1270 static void
1272 {
1275 tree access
1280 tree old_value;
1285 tf_warning_or_error);
1287 {
1293 else
1295 }
1303 ;
1305 {
1307 /* It's OK to use functions from a base when there are functions with
1309 else
1310 {
1315 }
1316 }
1318 {
1322 }
1324 /* Make type T see field decl FDECL with access ACCESS. */
1327 {
1330 }
1331 else
1333 }
1334 \f
1335 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1336 types with abi tags, add the corresponding identifiers to the VEC in
1337 *DATA and set IDENTIFIER_MARKED. */
1339 struct abi_tag_data
1340 {
1341 tree t;
1342 tree subob;
1343 // error_mark_node to get diagnostics; otherwise collect missing tags here
1344 tree tags;
1345 };
1347 static tree
1349 {
1353 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1354 anyway, but let's make sure of it. */
1358 {
1362 {
1366 {
1368 {
1369 /* We're collecting tags from template arguments. */
1375 /* Don't inherit this tag multiple times. */
1377 }
1379 /* Otherwise we're diagnosing missing tags. */
1381 {
1386 }
1387 else
1388 {
1395 }
1396 }
1397 }
1398 }
1400 }
1402 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1403 complete) template arguments. */
1405 static void
1407 {
1410 {
1413 {
1417 }
1418 }
1419 }
1421 /* Check that class T has all the abi tags that subobject SUBOB has, or
1422 warn if not. */
1424 static void
1426 {
1435 }
1437 void
1439 {
1448 {
1451 {
1455 }
1456 }
1458 // If we found some tags on our template arguments, add them to our
1459 // abi_tag attribute.
1461 {
1465 else
1469 }
1472 }
1474 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1475 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1476 properties of the bases. */
1478 static void
1482 {
1486 tree base_binfo;
1487 tree binfo;
1497 {
1506 /* If any base class is non-literal, so is the derived class. */
1510 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1511 here because the case of virtual functions but non-virtual
1512 dtor is handled in finish_struct_1. */
1517 /* If the base class doesn't have copy constructors or
1518 assignment operators that take const references, then the
1519 derived class cannot have such a member automatically
1520 generated. */
1529 /* A virtual base does not effect nearly emptiness. */
1530 ;
1532 {
1534 /* And if there is more than one nearly empty base, then the
1535 derived class is not nearly empty either. */
1537 else
1538 /* Remember we've seen one. */
1540 }
1542 /* If the base class is not empty or nearly empty, then this
1543 class cannot be nearly empty. */
1546 /* A lot of properties from the bases also apply to the derived
1547 class. */
1564 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1567 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1571 /* A standard-layout class is a class that:
1572 ...
1573 * has no non-standard-layout base classes, */
1576 {
1577 tree basefield;
1578 /* ...has no base classes of the same type as the first non-static
1579 data member... */
1581 && (same_type_ignoring_top_level_qualifiers_p
1584 else
1585 /* ...either has no non-static data members in the most-derived
1586 class and at most one base class with non-static data
1587 members, or has no base classes with non-static data
1588 members */
1592 {
1595 else
1598 }
1599 }
1601 /* Don't bother collecting tm attributes if transactional memory
1602 support is not enabled. */
1604 {
1608 }
1611 }
1613 /* If one of the base classes had TM attributes, and the current class
1614 doesn't define its own, then the current class inherits one. */
1616 {
1619 }
1620 }
1622 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1623 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1624 that have had a nearly-empty virtual primary base stolen by some
1625 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1626 T. */
1628 static void
1630 {
1634 tree base_binfo;
1636 /* Determine the primary bases of our bases. */
1639 {
1642 /* See if we're the non-virtual primary of our inheritance
1643 chain. */
1645 {
1652 /* We are the primary binfo. */
1654 }
1655 /* Determine if we have a virtual primary base, and mark it so.
1656 */
1658 {
1662 /* Someone already claimed this base. */
1664 else
1665 {
1666 tree delta;
1671 /* A virtual binfo might have been copied from within
1672 another hierarchy. As we're about to use it as a
1673 primary base, make sure the offsets match. */
1681 }
1682 }
1683 }
1685 /* First look for a dynamic direct non-virtual base. */
1687 {
1691 {
1694 }
1695 }
1697 /* A "nearly-empty" virtual base class can be the primary base
1698 class, if no non-virtual polymorphic base can be found. Look for
1699 a nearly-empty virtual dynamic base that is not already a primary
1700 base of something in the hierarchy. If there is no such base,
1701 just pick the first nearly-empty virtual base. */
1707 {
1709 {
1710 /* Found one that is not primary. */
1713 }
1715 /* Remember the first candidate. */
1717 }
1719 found:
1720 /* If we've got a primary base, use it. */
1722 {
1727 /* We are stealing a primary base. */
1731 {
1732 tree delta;
1735 /* A virtual binfo might have been copied from within
1736 another hierarchy. As we're about to use it as a primary
1737 base, make sure the offsets match. */
1742 }
1749 }
1750 }
1752 /* Update the variant types of T. */
1754 void
1756 {
1757 tree variants;
1763 variants;
1765 {
1766 /* These fields are in the _TYPE part of the node, not in
1767 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1777 /* Copy whatever these are holding today. */
1781 }
1782 }
1784 /* Early variant fixups: we apply attributes at the beginning of the class
1785 definition, and we need to fix up any variants that have already been
1786 made via elaborated-type-specifier so that check_qualified_type works. */
1788 void
1790 {
1791 tree variants;
1797 variants;
1799 {
1800 /* These are the two fields that check_qualified_type looks at and
1801 are affected by attributes. */
1804 }
1805 }
1806 \f
1807 /* Set memoizing fields and bits of T (and its variants) for later
1808 use. */
1810 static void
1812 {
1813 /* Fix up variants (if any). */
1817 /* For a class w/o baseclasses, 'finish_struct' has set
1818 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1819 Similarly for a class whose base classes do not have vtables.
1820 When neither of these is true, we might have removed abstract
1821 virtuals (by providing a definition), added some (by declaring
1822 new ones), or redeclared ones from a base class. We need to
1823 recalculate what's really an abstract virtual at this point (by
1824 looking in the vtables). */
1827 /* If this type has a copy constructor or a destructor, force its
1828 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1829 nonzero. This will cause it to be passed by invisible reference
1830 and prevent it from being returned in a register. */
1833 {
1834 tree variants;
1837 {
1840 }
1841 }
1842 }
1844 /* Issue warnings about T having private constructors, but no friends,
1845 and so forth.
1847 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1848 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1849 non-private static member functions. */
1851 static void
1853 {
1856 tree fn;
1859 /* If the class has friends, those entities might create and
1860 access instances, so we should not warn. */
1863 /* We will have warned when the template was declared; there's
1864 no need to warn on every instantiation. */
1866 /* There's no reason to even consider warning about this
1867 class. */
1870 /* We only issue one warning, if more than one applies, because
1871 otherwise, on code like:
1873 class A {
1874 // Oops - forgot `public:'
1875 A();
1876 A(const A&);
1877 ~A();
1878 };
1880 we warn several times about essentially the same problem. */
1882 /* Check to see if all (non-constructor, non-destructor) member
1883 functions are private. (Since there are no friends or
1884 non-private statics, we can't ever call any of the private member
1885 functions.) */
1887 /* We're not interested in compiler-generated methods; they don't
1888 provide any way to call private members. */
1890 {
1892 {
1894 /* A non-private static member function is just like a
1895 friend; it can create and invoke private member
1896 functions, and be accessed without a class
1897 instance. */
1901 /* Keep searching for a static member function. */
1902 }
1905 }
1908 {
1909 /* There are no non-private methods, and there's at least one
1910 private member function that isn't a constructor or
1911 destructor. (If all the private members are
1912 constructors/destructors we want to use the code below that
1913 issues error messages specifically referring to
1914 constructors/destructors.) */
1920 {
1923 }
1925 {
1929 }
1930 }
1932 /* Even if some of the member functions are non-private, the class
1933 won't be useful for much if all the constructors or destructors
1934 are private: such an object can never be created or destroyed. */
1937 {
1940 t);
1942 }
1944 /* Warn about classes that have private constructors and no friends. */
1946 /* Implicitly generated constructors are always public. */
1949 {
1952 /* If a non-template class does not define a copy
1953 constructor, one is defined for it, enabling it to avoid
1954 this warning. For a template class, this does not
1955 happen, and so we would normally get a warning on:
1957 template <class T> class C { private: C(); };
1959 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1960 complete non-template or fully instantiated classes have this
1961 flag set. */
1964 else
1966 {
1968 /* Ideally, we wouldn't count copy constructors (or, in
1969 fact, any constructor that takes an argument of the
1970 class type as a parameter) because such things cannot
1971 be used to construct an instance of the class unless
1972 you already have one. But, for now at least, we're
1973 more generous. */
1975 {
1978 }
1979 }
1982 {
1985 t);
1987 }
1988 }
1989 }
1992 gt_pointer_operator new_value;
1996 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1998 static int
2000 {
2013 }
2015 /* This routine compares two fields like method_name_cmp but using the
2016 pointer operator in resort_field_decl_data. */
2018 static int
2020 {
2029 {
2036 }
2038 }
2040 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2042 void
2045 gt_pointer_operator new_value,
2047 {
2051 tree fn;
2053 /* The type conversion ops have to live at the front of the vec, so we
2054 can't sort them. */
2062 {
2066 resort_method_name_cmp);
2067 }
2068 }
2070 /* Warn about duplicate methods in fn_fields.
2072 Sort methods that are not special (i.e., constructors, destructors,
2073 and type conversion operators) so that we can find them faster in
2074 search. */
2076 static void
2078 {
2079 tree fn_fields;
2089 /* Clear DECL_IN_AGGR_P for all functions. */
2094 /* Issue warnings about private constructors and such. If there are
2095 no methods, then some public defaults are generated. */
2098 /* The type conversion ops have to live at the front of the vec, so we
2099 can't sort them. */
2108 }
2110 /* Make BINFO's vtable have N entries, including RTTI entries,
2111 vbase and vcall offsets, etc. Set its type and call the back end
2112 to lay it out. */
2114 static void
2116 {
2117 tree atype;
2118 tree vtable;
2123 /* We may have to grow the vtable. */
2126 {
2130 }
2131 }
2133 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2134 have the same signature. */
2136 int
2138 {
2139 /* One destructor overrides another if they are the same kind of
2140 destructor. */
2144 /* But a non-destructor never overrides a destructor, nor vice
2145 versa, nor do different kinds of destructors override
2146 one-another. For example, a complete object destructor does not
2147 override a deleting destructor. */
2156 {
2164 }
2166 }
2168 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2169 subobject. */
2171 static bool
2173 {
2174 tree probe;
2177 {
2181 /* If we meet a virtual base, we can't follow the inheritance
2182 any more. See if the complete type of DERIVED contains
2183 such a virtual base. */
2186 }
2188 }
2191 /* The function for which we are trying to find a final overrider. */
2192 tree fn;
2193 /* The base class in which the function was declared. */
2194 tree declaring_base;
2195 /* The candidate overriders. */
2196 tree candidates;
2197 /* Path to most derived. */
2201 /* Add the overrider along the current path to FFOD->CANDIDATES.
2202 Returns true if an overrider was found; false otherwise. */
2204 static bool
2208 {
2209 tree method;
2211 /* If BINFO is not the most derived type, try a more derived class.
2212 A definition there will overrider a definition here. */
2214 {
2215 depth--;
2219 }
2223 {
2226 /* Remove any candidates overridden by this new function. */
2228 {
2229 /* If *CANDIDATE overrides METHOD, then METHOD
2230 cannot override anything else on the list. */
2233 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2236 else
2238 }
2240 /* Add the new function. */
2243 }
2246 }
2248 /* Called from find_final_overrider via dfs_walk. */
2250 static tree
2252 {
2260 }
2262 static tree
2264 {
2269 }
2271 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2272 FN and whose TREE_VALUE is the binfo for the base where the
2273 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2274 DERIVED) is the base object in which FN is declared. */
2276 static tree
2278 {
2279 find_final_overrider_data ffod;
2281 /* Getting this right is a little tricky. This is valid:
2283 struct S { virtual void f (); };
2284 struct T { virtual void f (); };
2285 struct U : public S, public T { };
2287 even though calling `f' in `U' is ambiguous. But,
2289 struct R { virtual void f(); };
2290 struct S : virtual public R { virtual void f (); };
2291 struct T : virtual public R { virtual void f (); };
2292 struct U : public S, public T { };
2294 is not -- there's no way to decide whether to put `S::f' or
2295 `T::f' in the vtable for `R'.
2297 The solution is to look at all paths to BINFO. If we find
2298 different overriders along any two, then there is a problem. */
2302 /* Determine the depth of the hierarchy. */
2313 /* If there was no winner, issue an error message. */
2318 }
2320 /* Return the index of the vcall offset for FN when TYPE is used as a
2321 virtual base. */
2323 static tree
2325 {
2327 tree_pair_p p;
2335 /* There should always be an appropriate index. */
2337 }
2339 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2340 dominated by T. FN is the old function; VIRTUALS points to the
2341 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2342 of that entry in the list. */
2344 static void
2347 {
2348 tree b;
2349 tree overrider;
2350 tree delta;
2351 tree virtual_base;
2352 tree first_defn;
2358 /* Find the nearest primary base (possibly binfo itself) which defines
2359 this function; this is the class the caller will convert to when
2360 calling FN through BINFO. */
2362 {
2367 /* The nearest definition is from a lost primary. */
2370 }
2373 /* Find the final overrider. */
2376 {
2379 }
2382 /* Check for adjusting covariant return types. */
2390 /* If the overrider is invalid, don't even try. */
2392 {
2393 /* If FN is a covariant thunk, we must figure out the adjustment
2394 to the final base FN was converting to. As OVERRIDER_TARGET might
2395 also be converting to the return type of FN, we have to
2396 combine the two conversions here. */
2403 {
2407 }
2408 else
2412 /* Find the equivalent binfo within the return type of the
2413 overriding function. We will want the vbase offset from
2414 there. */
2416 over_return);
2419 {
2420 /* There was no existing virtual thunk (which takes
2421 precedence). So find the binfo of the base function's
2422 return type within the overriding function's return type.
2423 We cannot call lookup base here, because we're inside a
2424 dfs_walk, and will therefore clobber the BINFO_MARKED
2425 flags. Fortunately we know the covariancy is valid (it
2426 has already been checked), so we can just iterate along
2427 the binfos, which have been chained in inheritance graph
2428 order. Of course it is lame that we have to repeat the
2429 search here anyway -- we should really be caching pieces
2430 of the vtable and avoiding this repeated work. */
2433 /* Find the base binfo within the overriding function's
2434 return type. We will always find a thunk_binfo, except
2435 when the covariancy is invalid (which we will have
2436 already diagnosed). */
2439 thunk_binfo;
2445 /* See if virtual inheritance is involved. */
2447 virtual_offset;
2454 {
2458 {
2459 /* We convert via virtual base. Adjust the fixed
2460 offset to be from there. */
2461 offset =
2465 }
2467 /* There was an existing fixed offset, this must be
2468 from the base just converted to, and the base the
2469 FN was thunking to. */
2471 else
2473 }
2474 }
2477 /* Replace the overriding function with a covariant thunk. We
2478 will emit the overriding function in its own slot as
2479 well. */
2482 }
2483 else
2487 /* If we need a covariant thunk, then we may need to adjust first_defn.
2488 The ABI specifies that the thunks emitted with a function are
2489 determined by which bases the function overrides, so we need to be
2490 sure that we're using a thunk for some overridden base; even if we
2491 know that the necessary this adjustment is zero, there may not be an
2492 appropriate zero-this-adjusment thunk for us to use since thunks for
2493 overriding virtual bases always use the vcall offset.
2495 Furthermore, just choosing any base that overrides this function isn't
2496 quite right, as this slot won't be used for calls through a type that
2497 puts a covariant thunk here. Calling the function through such a type
2498 will use a different slot, and that slot is the one that determines
2499 the thunk emitted for that base.
2501 So, keep looking until we find the base that we're really overriding
2502 in this slot: the nearest primary base that doesn't use a covariant
2503 thunk in this slot. */
2505 {
2507 /* We already know that the overrider needs a covariant thunk. */
2510 {
2517 }
2519 }
2521 /* Assume that we will produce a thunk that convert all the way to
2522 the final overrider, and not to an intermediate virtual base. */
2525 /* See if we can convert to an intermediate virtual base first, and then
2526 use the vcall offset located there to finish the conversion. */
2528 {
2529 /* If we find the final overrider, then we can stop
2530 walking. */
2535 /* If we find a virtual base, and we haven't yet found the
2536 overrider, then there is a virtual base between the
2537 declaring base (first_defn) and the final overrider. */
2539 {
2542 }
2543 }
2545 /* Compute the constant adjustment to the `this' pointer. The
2546 `this' pointer, when this function is called, will point at BINFO
2547 (or one of its primary bases, which are at the same offset). */
2549 /* The `this' pointer needs to be adjusted from the declaration to
2550 the nearest virtual base. */
2555 /* If the nearest definition is in a lost primary, we don't need an
2556 entry in our vtable. Except possibly in a constructor vtable,
2557 if we happen to get our primary back. In that case, the offset
2558 will be zero, as it will be a primary base. */
2560 else
2561 /* The `this' pointer needs to be adjusted from pointing to
2562 BINFO to pointing at the base where the final overrider
2563 appears. */
2574 else
2578 }
2580 /* Called from modify_all_vtables via dfs_walk. */
2582 static tree
2584 {
2586 tree virtuals;
2587 tree old_virtuals;
2591 /* A base without a vtable needs no modification, and its bases
2592 are uninteresting. */
2597 /* Don't do the primary vtable, if it's new. */
2601 /* There's no need to modify the vtable for a non-virtual primary
2602 base; we're not going to use that vtable anyhow. We do still
2603 need to do this for virtual primary bases, as they could become
2604 non-primary in a construction vtable. */
2609 /* Now, go through each of the virtual functions in the virtual
2610 function table for BINFO. Find the final overrider, and update
2611 the BINFO_VIRTUALS list appropriately. */
2614 virtuals;
2618 binfo,
2623 }
2625 /* Update all of the primary and secondary vtables for T. Create new
2626 vtables as required, and initialize their RTTI information. Each
2627 of the functions in VIRTUALS is declared in T and may override a
2628 virtual function from a base class; find and modify the appropriate
2629 entries to point to the overriding functions. Returns a list, in
2630 declaration order, of the virtual functions that are declared in T,
2631 but do not appear in the primary base class vtable, and which
2632 should therefore be appended to the end of the vtable for T. */
2634 static tree
2636 {
2640 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2644 /* Update all of the vtables. */
2647 /* Add virtual functions not already in our primary vtable. These
2648 will be both those introduced by this class, and those overridden
2649 from secondary bases. It does not include virtuals merely
2650 inherited from secondary bases. */
2652 {
2657 {
2658 /* We don't need to adjust the `this' pointer when
2659 calling this function. */
2663 /* This is a function not already in our vtable. Keep it. */
2665 }
2666 else
2667 /* We've already got an entry for this function. Skip it. */
2669 }
2672 }
2674 /* Get the base virtual function declarations in T that have the
2675 indicated NAME. */
2677 static tree
2679 {
2680 tree methods;
2685 /* Find virtual functions in T with the indicated NAME. */
2689 methods;
2691 {
2697 }
2703 {
2706 base_fndecls);
2707 }
2710 }
2712 /* If this declaration supersedes the declaration of
2713 a method declared virtual in the base class, then
2714 mark this field as being virtual as well. */
2716 void
2718 {
2721 /* In [temp.mem] we have:
2723 A specialization of a member function template does not
2724 override a virtual function from a base class. */
2731 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2732 the error_mark_node so that we know it is an overriding
2733 function. */
2734 {
2737 }
2740 {
2746 }
2751 }
2753 /* Warn about hidden virtual functions that are not overridden in t.
2754 We know that constructors and destructors don't apply. */
2756 static void
2758 {
2760 tree fns;
2763 /* We go through each separately named virtual function. */
2767 {
2768 tree fn;
2769 tree name;
2770 tree fndecl;
2771 tree base_fndecls;
2772 tree base_binfo;
2773 tree binfo;
2776 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2777 have the same name. Figure out what name that is. */
2779 /* There are no possibly hidden functions yet. */
2781 /* Iterate through all of the base classes looking for possibly
2782 hidden functions. */
2785 {
2788 base_fndecls);
2789 }
2791 /* If there are no functions to hide, continue. */
2795 /* Remove any overridden functions. */
2797 {
2800 {
2804 /* If the method from the base class has the same
2805 signature as the method from the derived class, it
2806 has been overridden. */
2809 else
2811 }
2812 }
2814 /* Now give a warning for all base functions without overriders,
2815 as they are hidden. */
2817 {
2818 /* Here we know it is a hider, and no overrider exists. */
2822 }
2823 }
2824 }
2826 /* Recursive helper for finish_struct_anon. */
2828 static void
2830 {
2834 {
2835 /* We're generally only interested in entities the user
2836 declared, but we also find nested classes by noticing
2837 the TYPE_DECL that we create implicitly. You're
2838 allowed to put one anonymous union inside another,
2839 though, so we explicitly tolerate that. We use
2840 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2841 we also allow unnamed types used for defining fields. */
2848 {
2850 {
2853 "%q+#D invalid; an anonymous union can "
2855 else
2857 "%q+#D invalid; an anonymous struct can "
2859 }
2861 }
2864 {
2866 {
2870 else
2873 }
2875 {
2879 else
2882 }
2883 }
2888 /* Recurse into the anonymous aggregates to handle correctly
2889 access control (c++/24926):
2891 class A {
2892 union {
2893 union {
2894 int i;
2895 };
2896 };
2897 };
2899 int j=A().i; */
2903 }
2904 }
2906 /* Check for things that are invalid. There are probably plenty of other
2907 things we should check for also. */
2909 static void
2911 {
2913 {
2922 }
2923 }
2925 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2926 will be used later during class template instantiation.
2927 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2928 a non-static member data (FIELD_DECL), a member function
2929 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2930 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2931 When FRIEND_P is nonzero, T is either a friend class
2932 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2933 (FUNCTION_DECL, TEMPLATE_DECL). */
2935 void
2937 {
2938 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2943 }
2945 /* This function is called from declare_virt_assop_and_dtor via
2946 dfs_walk_all.
2948 DATA is a type that direcly or indirectly inherits the base
2949 represented by BINFO. If BINFO contains a virtual assignment [copy
2950 assignment or move assigment] operator or a virtual constructor,
2951 declare that function in DATA if it hasn't been already declared. */
2953 static tree
2955 {
2963 /* A base without a vtable needs no modification, and its bases
2964 are uninteresting. */
2968 /* If this is a primary base, then we have already looked at the
2969 virtual functions of its vtable. */
2973 {
2977 {
2982 }
2986 }
2989 }
2991 /* If the class type T has a direct or indirect base that contains a
2992 virtual assignment operator or a virtual destructor, declare that
2993 function in T if it hasn't been already declared. */
2995 static void
2997 {
3005 dfs_declare_virt_assop_and_dtor,
3007 }
3009 /* Declare the inheriting constructor for class T inherited from base
3010 constructor CTOR with the parameter array PARMS of size NPARMS. */
3012 static void
3014 {
3015 /* We don't declare an inheriting ctor that would be a default,
3016 copy or move ctor for derived or base. */
3021 {
3025 }
3033 {
3036 }
3037 }
3039 /* Declare all the inheriting constructors for class T inherited from base
3040 constructor CTOR. */
3042 static void
3044 {
3050 {
3054 }
3057 {
3061 }
3062 }
3064 /* Create default constructors, assignment operators, and so forth for
3065 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3066 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3067 the class cannot have a default constructor, copy constructor
3068 taking a const reference argument, or an assignment operator taking
3069 a const reference, respectively. */
3071 static void
3075 {
3083 /* Destructor. */
3085 {
3086 /* In general, we create destructors lazily. */
3091 /* But if this is a Java class, any non-trivial destructor is
3092 invalid, even if compiler-generated. Therefore, if the
3093 destructor is non-trivial we create it now. */
3095 }
3097 /* [class.ctor]
3099 If there is no user-declared constructor for a class, a default
3100 constructor is implicitly declared. */
3102 {
3107 /* This might force the declaration. */
3109 }
3111 /* [class.ctor]
3113 If a class definition does not explicitly declare a copy
3114 constructor, one is declared implicitly. */
3116 {
3122 }
3124 /* If there is no assignment operator, one will be created if and
3125 when it is needed. For now, just record whether or not the type
3126 of the parameter to the assignment operator will be a const or
3127 non-const reference. */
3129 {
3135 }
3137 /* We can't be lazy about declaring functions that might override
3138 a virtual function from a base class. */
3142 {
3146 {
3147 /* declare, then remove the decl */
3156 }
3157 else
3159 }
3160 }
3162 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3163 count the number of fields in TYPE, including anonymous union
3164 members. */
3166 static int
3168 {
3169 tree x;
3172 {
3175 else
3177 }
3179 }
3181 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3182 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3183 elts, starting at offset IDX. */
3185 static int
3187 {
3188 tree x;
3190 {
3193 else
3195 }
3197 }
3199 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3200 starting at offset IDX. */
3202 static int
3206 {
3207 tree values;
3211 }
3213 /* FIELD is a bit-field. We are finishing the processing for its
3214 enclosing type. Issue any appropriate messages and set appropriate
3215 flags. Returns false if an error has been diagnosed. */
3217 static bool
3219 {
3221 tree w;
3223 /* Extract the declared width of the bitfield, which has been
3224 temporarily stashed in DECL_INITIAL. */
3227 /* Remove the bit-field width indicator so that the rest of the
3228 compiler does not treat that value as an initializer. */
3231 /* Detect invalid bit-field type. */
3233 {
3236 }
3237 else
3238 {
3240 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3243 /* detect invalid field size. */
3249 {
3252 }
3254 {
3257 }
3259 {
3262 }
3274 }
3277 {
3281 }
3282 else
3283 {
3284 /* Non-bit-fields are aligned for their type. */
3288 }
3289 }
3291 /* FIELD is a non bit-field. We are finishing the processing for its
3292 enclosing type T. Issue any appropriate messages and set appropriate
3293 flags. */
3295 static void
3297 tree t,
3301 {
3304 /* In C++98 an anonymous union cannot contain any fields which would change
3305 the settings of CANT_HAVE_CONST_CTOR and friends. */
3307 ;
3308 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3309 structs. So, we recurse through their fields here. */
3311 {
3312 tree fields;
3318 }
3319 /* Check members with class type for constructors, destructors,
3320 etc. */
3322 {
3323 /* Never let anything with uninheritable virtuals
3324 make it through without complaint. */
3328 {
3333 field);
3338 field);
3340 {
3344 }
3345 }
3346 else
3347 {
3360 }
3369 }
3374 {
3375 /* `build_class_init_list' does not recognize
3376 non-FIELD_DECLs. */
3380 }
3381 }
3383 /* Check the data members (both static and non-static), class-scoped
3384 typedefs, etc., appearing in the declaration of T. Issue
3385 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3386 declaration order) of access declarations; each TREE_VALUE in this
3387 list is a USING_DECL.
3389 In addition, set the following flags:
3391 EMPTY_P
3392 The class is empty, i.e., contains no non-static data members.
3394 CANT_HAVE_CONST_CTOR_P
3395 This class cannot have an implicitly generated copy constructor
3396 taking a const reference.
3398 CANT_HAVE_CONST_ASN_REF
3399 This class cannot have an implicitly generated assignment
3400 operator taking a const reference.
3402 All of these flags should be initialized before calling this
3403 function.
3405 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3406 fields can be added by adding to this chain. */
3408 static void
3412 {
3420 /* Assume there are no access declarations. */
3422 /* Assume this class has no pointer members. */
3424 /* Assume none of the members of this class have default
3425 initializations. */
3429 {
3437 {
3438 /* Save the access declarations for our caller. */
3441 }
3447 /* If we've gotten this far, it's a data member, possibly static,
3448 or an enumerator. */
3452 /* When this goes into scope, it will be a non-local reference. */
3456 {
3457 /* [class.union]
3459 If a union contains a static data member, or a member of
3460 reference type, the program is ill-formed. */
3462 {
3465 }
3467 {
3472 }
3473 }
3475 /* Perform error checking that did not get done in
3476 grokdeclarator. */
3478 {
3482 }
3484 {
3488 }
3496 /* Now it can only be a FIELD_DECL. */
3501 /* If at least one non-static data member is non-literal, the whole
3502 class becomes non-literal. Note: if the type is incomplete we
3503 will complain later on. */
3507 /* A standard-layout class is a class that:
3508 ...
3509 has the same access control (Clause 11) for all non-static data members,
3510 ... */
3517 /* If this is of reference type, check if it needs an init. */
3519 {
3525 /* ARM $12.6.2: [A member initializer list] (or, for an
3526 aggregate, initialization by a brace-enclosed list) is the
3527 only way to initialize nonstatic const and reference
3528 members. */
3531 }
3536 {
3538 {
3539 warning
3542 x);
3544 }
3548 }
3551 /* We don't treat zero-width bitfields as making a class
3552 non-empty. */
3553 ;
3554 else
3555 {
3556 /* The class is non-empty. */
3558 /* The class is not even nearly empty. */
3560 /* If one of the data members contains an empty class,
3561 so does T. */
3565 }
3567 /* This is used by -Weffc++ (see below). Warn only for pointers
3568 to members which might hold dynamic memory. So do not warn
3569 for pointers to functions or pointers to members. */
3575 {
3580 }
3586 {
3588 {
3592 }
3594 {
3598 }
3599 }
3602 /* DR 148 now allows pointers to members (which are POD themselves),
3603 to be allowed in POD structs. */
3612 /* We set DECL_C_BIT_FIELD in grokbitfield.
3613 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3616 cant_have_const_ctor_p,
3617 no_const_asn_ref_p,
3620 /* Now that we've removed bit-field widths from DECL_INITIAL,
3621 anything left in DECL_INITIAL is an NSDMI that makes the class
3622 non-aggregate. */
3626 /* If any field is const, the structure type is pseudo-const. */
3628 {
3633 /* ARM $12.6.2: [A member initializer list] (or, for an
3634 aggregate, initialization by a brace-enclosed list) is the
3635 only way to initialize nonstatic const and reference
3636 members. */
3639 }
3640 /* A field that is pseudo-const makes the structure likewise. */
3642 {
3647 }
3649 /* Core issue 80: A nonstatic data member is required to have a
3650 different name from the class iff the class has a
3651 user-declared constructor. */
3655 }
3657 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3658 it should also define a copy constructor and an assignment operator to
3659 implement the correct copy semantic (deep vs shallow, etc.). As it is
3660 not feasible to check whether the constructors do allocate dynamic memory
3661 and store it within members, we approximate the warning like this:
3663 -- Warn only if there are members which are pointers
3664 -- Warn only if there is a non-trivial constructor (otherwise,
3665 there cannot be memory allocated).
3666 -- Warn only if there is a non-trivial destructor. We assume that the
3667 user at least implemented the cleanup correctly, and a destructor
3668 is needed to free dynamic memory.
3670 This seems enough for practical purposes. */
3672 && has_pointers
3676 {
3680 {
3685 }
3689 }
3691 /* Non-static data member initializers make the default constructor
3692 non-trivial. */
3694 {
3697 }
3699 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3703 /* Check anonymous struct/anonymous union fields. */
3706 /* We've built up the list of access declarations in reverse order.
3707 Fix that now. */
3709 }
3711 /* If TYPE is an empty class type, records its OFFSET in the table of
3712 OFFSETS. */
3714 static int
3716 {
3717 splay_tree_node n;
3722 /* Record the location of this empty object in OFFSETS. */
3730 type,
3734 }
3736 /* Returns nonzero if TYPE is an empty class type and there is
3737 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3739 static int
3741 {
3742 splay_tree_node n;
3743 tree t;
3748 /* Record the location of this empty object in OFFSETS. */
3758 }
3760 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3761 F for every subobject, passing it the type, offset, and table of
3762 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3763 be traversed.
3765 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3766 than MAX_OFFSET will not be walked.
3768 If F returns a nonzero value, the traversal ceases, and that value
3769 is returned. Otherwise, returns zero. */
3771 static int
3773 subobject_offset_fn f,
3774 tree offset,
3775 splay_tree offsets,
3776 tree max_offset,
3778 {
3782 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3783 stop. */
3791 {
3795 }
3798 {
3799 tree field;
3800 tree binfo;
3803 /* Avoid recursing into objects that are not interesting. */
3807 /* Record the location of TYPE. */
3812 /* Iterate through the direct base classes of TYPE. */
3816 {
3817 tree binfo_offset;
3830 offset,
3832 else
3833 {
3834 tree orig_binfo;
3835 /* We cannot rely on BINFO_OFFSET being set for the base
3836 class yet, but the offsets for direct non-virtual
3837 bases can be calculated by going back to the TYPE. */
3840 offset,
3842 }
3845 f,
3846 binfo_offset,
3847 offsets,
3848 max_offset,
3853 }
3856 {
3860 /* Iterate through the virtual base classes of TYPE. In G++
3861 3.2, we included virtual bases in the direct base class
3862 loop above, which results in incorrect results; the
3863 correct offsets for virtual bases are only known when
3864 working with the most derived type. */
3868 {
3870 f,
3872 offset,
3874 offsets,
3875 max_offset,
3879 }
3880 else
3881 {
3882 /* We still have to walk the primary base, if it is
3883 virtual. (If it is non-virtual, then it was walked
3884 above.) */
3890 {
3891 r = (walk_subobject_offsets
3896 }
3897 }
3898 }
3900 /* Iterate through the fields of TYPE. */
3905 {
3906 tree field_offset;
3910 else
3911 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3915 f,
3917 offset,
3918 field_offset),
3919 offsets,
3920 max_offset,
3924 }
3925 }
3927 {
3930 tree index;
3932 /* Avoid recursing into objects that are not interesting. */
3937 /* Step through each of the elements in the array. */
3939 /* G++ 3.2 had an off-by-one error here. */
3944 {
3946 f,
3947 offset,
3948 offsets,
3949 max_offset,
3955 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3956 there's no point in iterating through the remaining
3957 elements of the array. */
3960 }
3961 }
3964 }
3966 /* Record all of the empty subobjects of TYPE (either a type or a
3967 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3968 is being placed at OFFSET; otherwise, it is a base class that is
3969 being placed at OFFSET. */
3971 static void
3973 tree offset,
3974 splay_tree offsets,
3976 {
3977 tree max_offset;
3978 /* If recording subobjects for a non-static data member or a
3979 non-empty base class , we do not need to record offsets beyond
3980 the size of the biggest empty class. Additional data members
3981 will go at the end of the class. Additional base classes will go
3982 either at offset zero (if empty, in which case they cannot
3983 overlap with offsets past the size of the biggest empty class) or
3984 at the end of the class.
3986 However, if we are placing an empty base class, then we must record
3987 all offsets, as either the empty class is at offset zero (where
3988 other empty classes might later be placed) or at the end of the
3989 class (where other objects might then be placed, so other empty
3990 subobjects might later overlap). */
3994 else
3998 }
4000 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4001 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4002 virtual bases of TYPE are examined. */
4004 static int
4006 tree offset,
4007 splay_tree offsets,
4009 {
4010 splay_tree_node max_node;
4012 /* Get the node in OFFSETS that indicates the maximum offset where
4013 an empty subobject is located. */
4015 /* If there aren't any empty subobjects, then there's no point in
4016 performing this check. */
4022 vbases_p);
4023 }
4025 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4026 non-static data member of the type indicated by RLI. BINFO is the
4027 binfo corresponding to the base subobject, OFFSETS maps offsets to
4028 types already located at those offsets. This function determines
4029 the position of the DECL. */
4031 static void
4033 tree decl,
4034 tree binfo,
4035 splay_tree offsets)
4036 {
4039 tree type;
4042 {
4043 /* For the purposes of determining layout conflicts, we want to
4044 use the class type of BINFO; TREE_TYPE (DECL) will be the
4045 CLASSTYPE_AS_BASE version, which does not contain entries for
4046 zero-sized bases. */
4049 }
4050 else
4051 {
4054 }
4056 /* Try to place the field. It may take more than one try if we have
4057 a hard time placing the field without putting two objects of the
4058 same type at the same address. */
4060 {
4063 /* Place this field. */
4067 /* We have to check to see whether or not there is already
4068 something of the same type at the offset we're about to use.
4069 For example, consider:
4071 struct S {};
4072 struct T : public S { int i; };
4073 struct U : public S, public T {};
4075 Here, we put S at offset zero in U. Then, we can't put T at
4076 offset zero -- its S component would be at the same address
4077 as the S we already allocated. So, we have to skip ahead.
4078 Since all data members, including those whose type is an
4079 empty class, have nonzero size, any overlap can happen only
4080 with a direct or indirect base-class -- it can't happen with
4081 a data member. */
4082 /* In a union, overlap is permitted; all members are placed at
4083 offset zero. */
4086 /* G++ 3.2 did not check for overlaps when placing a non-empty
4087 virtual base. */
4092 {
4093 /* Strip off the size allocated to this field. That puts us
4094 at the first place we could have put the field with
4095 proper alignment. */
4098 /* Bump up by the alignment required for the type. */
4099 rli->bitpos
4105 }
4106 else
4107 /* There was no conflict. We're done laying out this field. */
4109 }
4111 /* Now that we know where it will be placed, update its
4112 BINFO_OFFSET. */
4114 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4115 this point because their BINFO_OFFSET is copied from another
4116 hierarchy. Therefore, we may not need to add the entire
4117 OFFSET. */
4123 }
4125 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4127 static int
4129 tree offset,
4131 {
4133 }
4135 /* Layout the empty base BINFO. EOC indicates the byte currently just
4136 past the end of the class, and should be correctly aligned for a
4137 class of the type indicated by BINFO; OFFSETS gives the offsets of
4138 the empty bases allocated so far. T is the most derived
4139 type. Return nonzero iff we added it at the end. */
4141 static bool
4144 {
4145 tree alignment;
4149 /* This routine should only be used for empty classes. */
4154 {
4156 propagate_binfo_offsets
4159 else
4161 "offset of empty base %qT may not be ABI-compliant and may"
4164 }
4166 /* This is an empty base class. We first try to put it at offset
4167 zero. */
4170 offsets,
4172 {
4173 /* That didn't work. Now, we move forward from the next
4174 available spot in the class. */
4178 {
4181 offsets,
4183 /* We finally found a spot where there's no overlap. */
4186 /* There's overlap here, too. Bump along to the next spot. */
4188 }
4189 }
4192 {
4197 }
4200 }
4202 /* Layout the base given by BINFO in the class indicated by RLI.
4203 *BASE_ALIGN is a running maximum of the alignments of
4204 any base class. OFFSETS gives the location of empty base
4205 subobjects. T is the most derived type. Return nonzero if the new
4206 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4207 *NEXT_FIELD, unless BINFO is for an empty base class.
4209 Returns the location at which the next field should be inserted. */
4214 {
4219 /* This error is now reported in xref_tag, thus giving better
4220 location information. */
4223 /* Place the base class. */
4225 {
4226 tree decl;
4228 /* The containing class is non-empty because it has a non-empty
4229 base class. */
4232 /* Create the FIELD_DECL. */
4239 {
4247 /* Try to place the field. It may take more than one try if we
4248 have a hard time placing the field without putting two
4249 objects of the same type at the same address. */
4251 /* Add the new FIELD_DECL to the list of fields for T. */
4255 }
4256 }
4257 else
4258 {
4259 tree eoc;
4262 /* On some platforms (ARM), even empty classes will not be
4263 byte-aligned. */
4268 /* A nearly-empty class "has no proper base class that is empty,
4269 not morally virtual, and at an offset other than zero." */
4271 {
4274 /* The check above (used in G++ 3.2) is insufficient because
4275 an empty class placed at offset zero might itself have an
4276 empty base at a nonzero offset. */
4278 empty_base_at_nonzero_offset_p,
4279 size_zero_node,
4283 {
4286 else
4288 "class %qT will be considered nearly empty in a "
4290 }
4291 }
4293 /* We do not create a FIELD_DECL for empty base classes because
4294 it might overlap some other field. We want to be able to
4295 create CONSTRUCTORs for the class by iterating over the
4296 FIELD_DECLs, and the back end does not handle overlapping
4297 FIELD_DECLs. */
4299 /* An empty virtual base causes a class to be non-empty
4300 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4301 here because that was already done when the virtual table
4302 pointer was created. */
4303 }
4305 /* Record the offsets of BINFO and its base subobjects. */
4308 offsets,
4312 }
4314 /* Layout all of the non-virtual base classes. Record empty
4315 subobjects in OFFSETS. T is the most derived type. Return nonzero
4316 if the type cannot be nearly empty. The fields created
4317 corresponding to the base classes will be inserted at
4318 *NEXT_FIELD. */
4320 static void
4323 {
4324 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4325 subobjects. */
4330 /* The primary base class is always allocated first. */
4335 /* Now allocate the rest of the bases. */
4337 {
4338 tree base_binfo;
4342 /* The primary base was already allocated above, so we don't
4343 need to allocate it again here. */
4347 /* Virtual bases are added at the end (a primary virtual base
4348 will have already been added). */
4354 }
4355 }
4357 /* Go through the TYPE_METHODS of T issuing any appropriate
4358 diagnostics, figuring out which methods override which other
4359 methods, and so forth. */
4361 static void
4363 {
4364 tree x;
4367 {
4371 /* The name of the field is the original field name
4372 Save this in auxiliary field for later overloading. */
4374 {
4378 }
4379 /* All user-provided destructors are non-trivial.
4380 Constructors and assignment ops are handled in
4381 grok_special_member_properties. */
4384 }
4385 }
4387 /* FN is a constructor or destructor. Clone the declaration to create
4388 a specialized in-charge or not-in-charge version, as indicated by
4389 NAME. */
4391 static tree
4393 {
4394 tree parms;
4395 tree clone;
4397 /* Copy the function. */
4399 /* Reset the function name. */
4402 /* Remember where this function came from. */
4404 /* Make it easy to find the CLONE given the FN. */
4408 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4410 {
4417 }
4420 /* There's no pending inline data for this function. */
4424 /* The base-class destructor is not virtual. */
4426 {
4430 }
4432 /* If there was an in-charge parameter, drop it from the function
4433 type. */
4435 {
4436 tree basetype;
4437 tree parmtypes;
4438 tree exceptions;
4443 /* Skip the `this' parameter. */
4445 /* Skip the in-charge parameter. */
4447 /* And the VTT parm, in a complete [cd]tor. */
4451 /* If this is subobject constructor or destructor, add the vtt
4452 parameter. */
4456 parmtypes);
4459 exceptions);
4463 }
4465 /* Copy the function parameters. */
4467 /* Remove the in-charge parameter. */
4469 {
4473 }
4474 /* And the VTT parm, in a complete [cd]tor. */
4476 {
4479 else
4480 {
4484 }
4485 }
4488 {
4491 }
4493 /* Create the RTL for this function. */
4501 }
4503 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4504 not invoke this function directly.
4506 For a non-thunk function, returns the address of the slot for storing
4507 the function it is a clone of. Otherwise returns NULL_TREE.
4509 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4510 cloned_function is unset. This is to support the separate
4511 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4512 on a template makes sense, but not the former. */
4514 tree *
4516 {
4524 {
4525 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4528 else
4529 #endif
4531 }
4536 else
4538 }
4540 /* Produce declarations for all appropriate clones of FN. If
4541 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4542 CLASTYPE_METHOD_VEC as well. */
4544 void
4546 {
4547 tree clone;
4549 /* Avoid inappropriate cloning. */
4555 {
4556 /* For each constructor, we need two variants: an in-charge version
4557 and a not-in-charge version. */
4564 }
4565 else
4566 {
4569 /* For each destructor, we need three variants: an in-charge
4570 version, a not-in-charge version, and an in-charge deleting
4571 version. We clone the deleting version first because that
4572 means it will go second on the TYPE_METHODS list -- and that
4573 corresponds to the correct layout order in the virtual
4574 function table.
4576 For a non-virtual destructor, we do not build a deleting
4577 destructor. */
4579 {
4583 }
4590 }
4592 /* Note that this is an abstract function that is never emitted. */
4594 }
4596 /* DECL is an in charge constructor, which is being defined. This will
4597 have had an in class declaration, from whence clones were
4598 declared. An out-of-class definition can specify additional default
4599 arguments. As it is the clones that are involved in overload
4600 resolution, we must propagate the information from the DECL to its
4601 clones. */
4603 void
4605 {
4606 tree clone;
4610 {
4617 /* Skip the 'this' parameter. */
4633 {
4638 {
4639 /* A default parameter has been added. Adjust the
4640 clone's parameters. */
4644 tree type;
4649 {
4652 clone_parms);
4654 }
4657 clone_parms);
4666 }
4667 }
4669 }
4670 }
4672 /* For each of the constructors and destructors in T, create an
4673 in-charge and not-in-charge variant. */
4675 static void
4677 {
4678 tree fns;
4680 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4681 out now. */
4689 }
4691 /* Deduce noexcept for a destructor DTOR. */
4693 void
4695 {
4697 {
4704 }
4705 }
4707 /* For each destructor in T, deduce noexcept:
4709 12.4/3: A declaration of a destructor that does not have an
4710 exception-specification is implicitly considered to have the
4711 same exception-specification as an implicit declaration (15.4). */
4713 static void
4715 {
4716 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4717 out now. */
4723 }
4725 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4726 of TYPE for virtual functions which FNDECL overrides. Return a
4727 mask of the tm attributes found therein. */
4729 static int
4731 {
4733 tree base_binfo;
4737 {
4747 else
4749 }
4752 }
4754 /* Subroutine of set_method_tm_attributes. Handle the checks and
4755 inheritance for one virtual method FNDECL. */
4757 static void
4759 {
4760 tree tm_attr;
4765 /* If FNDECL doesn't actually override anything (i.e. T is the
4766 class that first declares FNDECL virtual), then we're done. */
4773 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4774 tm_pure must match exactly, otherwise no weakening of
4775 tm_safe > tm_callable > nothing. */
4776 /* ??? The tm_pure attribute didn't make the transition to the
4777 multivendor language spec. */
4779 {
4781 {
4784 }
4785 }
4786 /* If the overridden function is tm_pure, then FNDECL must be. */
4789 /* Look for base class combinations that cannot be satisfied. */
4791 {
4797 }
4798 /* If FNDECL did not declare an attribute, then inherit the most
4799 restrictive one. */
4801 {
4803 }
4804 /* Otherwise validate that we're not weaker than a function
4805 that is being overridden. */
4806 else
4807 {
4811 }
4814 err_override:
4818 }
4820 /* For each of the methods in T, propagate a class-level tm attribute. */
4822 static void
4824 {
4827 /* Don't bother collecting tm attributes if transactional memory
4828 support is not enabled. */
4832 /* Process virtual methods first, as they inherit directly from the
4833 base virtual function and also require validation of new attributes. */
4835 {
4836 tree vchain;
4839 {
4844 }
4845 }
4847 /* If the class doesn't have an attribute, nothing more to do. */
4852 /* Any method that does not yet have a tm attribute inherits
4853 the one from the class. */
4855 {
4858 }
4859 }
4861 /* Returns true iff class T has a user-defined constructor other than
4862 the default constructor. */
4864 bool
4866 {
4867 tree fns;
4873 {
4880 }
4883 }
4885 /* Returns the defaulted constructor if T has one. Otherwise, returns
4886 NULL_TREE. */
4888 tree
4890 {
4897 {
4901 {
4907 }
4908 }
4911 }
4913 /* Returns true iff FN is a user-provided function, i.e. user-declared
4914 and not defaulted at its first declaration; or explicit, private,
4915 protected, or non-const. */
4917 bool
4919 {
4922 else
4926 }
4928 /* Returns true iff class T has a user-provided constructor. */
4930 bool
4932 {
4933 tree fns;
4941 /* This can happen in error cases; avoid crashing. */
4950 }
4952 /* Returns true iff class T has a user-provided default constructor. */
4954 bool
4956 {
4957 tree fns;
4963 {
4969 }
4972 }
4974 /* TYPE is being used as a virtual base, and has a non-trivial move
4975 assignment. Return true if this is due to there being a user-provided
4976 move assignment in TYPE or one of its subobjects; if there isn't, then
4977 multiple move assignment can't cause any harm. */
4979 bool
4981 {
4982 /* Does the type itself have a user-provided move assignment operator? */
4986 {
4990 }
4992 /* Do any of its bases? */
4994 tree base_binfo;
4999 /* Or non-static data members? */
5001 {
5006 }
5008 /* Seems not. */
5010 }
5012 /* If default-initialization leaves part of TYPE uninitialized, returns
5013 a DECL for the field or TYPE itself (DR 253). */
5015 tree
5017 {
5028 {
5032 }
5037 {
5041 }
5044 }
5046 /* Returns true iff for class T, a trivial synthesized default constructor
5047 would be constexpr. */
5049 bool
5051 {
5052 /* A defaulted trivial default constructor is constexpr
5053 if there is nothing to initialize. */
5056 }
5058 /* Returns true iff class T has a constexpr default constructor. */
5060 bool
5062 {
5063 tree fns;
5066 {
5067 /* The caller should have stripped an enclosing array. */
5070 }
5072 {
5075 /* Non-trivial, we need to check subobject constructors. */
5077 }
5080 }
5082 /* Returns true iff class TYPE has a virtual destructor. */
5084 bool
5086 {
5087 tree dtor;
5095 }
5097 /* Returns true iff class T has a move constructor. */
5099 bool
5101 {
5102 tree fns;
5105 {
5108 }
5118 }
5120 /* Returns true iff class T has a move assignment operator. */
5122 bool
5124 {
5125 tree fns;
5128 {
5131 }
5139 }
5141 /* Returns true iff class T has a move constructor that was explicitly
5142 declared in the class body. Note that this is different from
5143 "user-provided", which doesn't include functions that are defaulted in
5144 the class. */
5146 bool
5148 {
5149 tree fns;
5158 {
5162 }
5165 }
5167 /* Returns true iff class T has a move assignment operator that was
5168 explicitly declared in the class body. */
5170 bool
5172 {
5173 tree fns;
5180 {
5184 }
5187 }
5189 /* Nonzero if we need to build up a constructor call when initializing an
5190 object of this class, either because it has a user-declared constructor
5191 or because it doesn't have a default constructor (so we need to give an
5192 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5193 what you care about is whether or not an object can be produced by a
5194 constructor (e.g. so we don't set TREE_READONLY on const variables of
5195 such type); use this function when what you care about is whether or not
5196 to try to call a constructor to create an object. The latter case is
5197 the former plus some cases of constructors that cannot be called. */
5199 bool
5201 {
5202 tree inner;
5212 /* A user-declared constructor might be private, and a constructor might
5213 be trivial but deleted. */
5216 {
5221 }
5223 }
5225 /* Like type_build_ctor_call, but for destructors. */
5227 bool
5229 {
5230 tree inner;
5239 /* A user-declared destructor might be private, and a destructor might
5240 be trivial but deleted. */
5243 {
5248 }
5250 }
5252 /* Remove all zero-width bit-fields from T. */
5254 static void
5256 {
5261 {
5264 /* We should not be confused by the fact that grokbitfield
5265 temporarily sets the width of the bit field into
5266 DECL_INITIAL (*fieldsp).
5267 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5268 to that width. */
5271 else
5273 }
5274 }
5276 /* Returns TRUE iff we need a cookie when dynamically allocating an
5277 array whose elements have the indicated class TYPE. */
5279 static bool
5281 {
5282 tree fns;
5287 /* If there's a non-trivial destructor, we need a cookie. In order
5288 to iterate through the array calling the destructor for each
5289 element, we'll have to know how many elements there are. */
5293 /* If the usual deallocation function is a two-argument whose second
5294 argument is of type `size_t', then we have to pass the size of
5295 the array to the deallocation function, so we will need to store
5296 a cookie. */
5300 /* If there are no `operator []' members, or the lookup is
5301 ambiguous, then we don't need a cookie. */
5304 /* Loop through all of the functions. */
5306 {
5307 tree fn;
5308 tree second_parm;
5310 /* Select the current function. */
5312 /* See if this function is a one-argument delete function. If
5313 it is, then it will be the usual deallocation function. */
5317 /* Do not consider this function if its second argument is an
5318 ellipsis. */
5321 /* Otherwise, if we have a two-argument function and the second
5322 argument is `size_t', it will be the usual deallocation
5323 function -- unless there is one-argument function, too. */
5327 }
5330 }
5332 /* Finish computing the `literal type' property of class type T.
5334 At this point, we have already processed base classes and
5335 non-static data members. We need to check whether the copy
5336 constructor is trivial, the destructor is trivial, and there
5337 is a trivial default constructor or at least one constexpr
5338 constructor other than the copy constructor. */
5340 static void
5342 {
5343 tree fn;
5359 {
5362 {
5366 }
5367 }
5368 }
5370 /* T is a non-literal type used in a context which requires a constant
5371 expression. Explain why it isn't literal. */
5373 void
5375 {
5385 /* Already explained. */
5394 {
5396 "default constructor, and has no constexpr constructor that "
5400 {
5401 /* Note that we can't simply call locate_ctor because when the
5402 constructor is deleted it just returns NULL_TREE. */
5403 tree fns;
5405 {
5412 {
5415 else
5418 }
5419 }
5420 }
5421 }
5422 else
5423 {
5427 {
5430 {
5435 }
5436 }
5438 {
5439 tree ftype;
5444 {
5449 }
5450 }
5451 }
5452 }
5454 /* Check the validity of the bases and members declared in T. Add any
5455 implicitly-generated functions (like copy-constructors and
5456 assignment operators). Compute various flag bits (like
5457 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5458 level: i.e., independently of the ABI in use. */
5460 static void
5462 {
5463 /* Nonzero if the implicitly generated copy constructor should take
5464 a non-const reference argument. */
5466 /* Nonzero if the implicitly generated assignment operator
5467 should take a non-const reference argument. */
5469 tree access_decls;
5472 tree fn;
5474 /* Pick up any abi_tags from our template arguments before checking. */
5477 /* By default, we use const reference arguments and generate default
5478 constructors. */
5482 /* Check all the base-classes. */
5486 /* Deduce noexcept on destructors. This needs to happen after we've set
5487 triviality flags appropriately for our bases. */
5491 /* Check all the method declarations. */
5494 /* Save the initial values of these flags which only indicate whether
5495 or not the class has user-provided functions. As we analyze the
5496 bases and members we can set these flags for other reasons. */
5500 /* Check all the data member declarations. We cannot call
5501 check_field_decls until we have called check_bases check_methods,
5502 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5503 being set appropriately. */
5508 /* A nearly-empty class has to be vptr-containing; a nearly empty
5509 class contains just a vptr. */
5513 /* Do some bookkeeping that will guide the generation of implicitly
5514 declared member functions. */
5517 /* We need to call a constructor for this class if it has a
5518 user-provided constructor, or if the default constructor is going
5519 to initialize the vptr. (This is not an if-and-only-if;
5520 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5521 themselves need constructing.) */
5524 /* [dcl.init.aggr]
5526 An aggregate is an array or a class with no user-provided
5527 constructors ... and no virtual functions.
5529 Again, other conditions for being an aggregate are checked
5530 elsewhere. */
5533 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5534 retain the old definition internally for ABI reasons. */
5543 /* If the class has no user-declared constructor, but does have
5544 non-static const or reference data members that can never be
5545 initialized, issue a warning. */
5547 /* Classes with user-declared constructors are presumed to
5548 initialize these members. */
5550 /* Aggregates can be initialized with brace-enclosed
5551 initializers. */
5553 {
5554 tree field;
5557 {
5558 tree type;
5573 }
5574 }
5576 /* Synthesize any needed methods. */
5578 cant_have_const_ctor,
5579 no_const_asn_ref);
5581 /* Check defaulted declarations here so we have cant_have_const_ctor
5582 and don't need to worry about clones. */
5585 {
5588 {
5589 bool imp_const_p
5595 /* If the function is defaulted outside the class, we just
5596 give the synthesis error. */
5599 }
5601 }
5604 {
5605 /* "The closure type associated with a lambda-expression has a deleted
5606 default constructor and a deleted copy assignment operator." */
5612 /* "This class type is not an aggregate." */
5614 }
5616 /* Compute the 'literal type' property before we
5617 do anything with non-static member functions. */
5620 /* Create the in-charge and not-in-charge variants of constructors
5621 and destructors. */
5624 /* Process the using-declarations. */
5628 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5631 /* Figure out whether or not we will need a cookie when dynamically
5632 allocating an array of this type. */
5635 }
5637 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5638 accordingly. If a new vfield was created (because T doesn't have a
5639 primary base class), then the newly created field is returned. It
5640 is not added to the TYPE_FIELDS list; it is the caller's
5641 responsibility to do that. Accumulate declared virtual functions
5642 on VIRTUALS_P. */
5644 static tree
5646 {
5647 tree fn;
5649 /* Collect the virtual functions declared in T. */
5653 {
5662 }
5664 /* If we couldn't find an appropriate base class, create a new field
5665 here. Even if there weren't any new virtual functions, we might need a
5666 new virtual function table if we're supposed to include vptrs in
5667 all classes that need them. */
5669 {
5670 /* We build this decl with vtbl_ptr_type_node, which is a
5671 `vtable_entry_type*'. It might seem more precise to use
5672 `vtable_entry_type (*)[N]' where N is the number of virtual
5673 functions. However, that would require the vtable pointer in
5674 base classes to have a different type than the vtable pointer
5675 in derived classes. We could make that happen, but that
5676 still wouldn't solve all the problems. In particular, the
5677 type-based alias analysis code would decide that assignments
5678 to the base class vtable pointer can't alias assignments to
5679 the derived class vtable pointer, since they have different
5680 types. Thus, in a derived class destructor, where the base
5681 class constructor was inlined, we could generate bad code for
5682 setting up the vtable pointer.
5684 Therefore, we use one type for all vtable pointers. We still
5685 use a type-correct type; it's just doesn't indicate the array
5686 bounds. That's better than using `void*' or some such; it's
5687 cleaner, and it let's the alias analysis code know that these
5688 stores cannot alias stores to void*! */
5689 tree field;
5702 /* This class is non-empty. */
5706 }
5709 }
5711 /* Add OFFSET to all base types of BINFO which is a base in the
5712 hierarchy dominated by T.
5714 OFFSET, which is a type offset, is number of bytes. */
5716 static void
5718 {
5720 tree primary_binfo;
5721 tree base_binfo;
5723 /* Update BINFO's offset. */
5728 offset));
5730 /* Find the primary base class. */
5736 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5737 downwards. */
5739 {
5740 /* Don't do the primary base twice. */
5748 }
5749 }
5751 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5752 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5753 empty subobjects of T. */
5755 static void
5757 {
5758 tree vbase;
5767 {
5768 /* In G++ 3.2, we incorrectly rounded the size before laying out
5769 the virtual bases. */
5771 #ifdef STRUCTURE_SIZE_BOUNDARY
5772 /* Packed structures don't need to have minimum size. */
5775 #endif
5779 }
5781 /* Find the last field. The artificial fields created for virtual
5782 bases will go after the last extant field to date. */
5787 /* Go through the virtual bases, allocating space for each virtual
5788 base that is not already a primary base class. These are
5789 allocated in inheritance graph order. */
5791 {
5796 {
5799 /* This virtual base is not a primary base of any class in the
5800 hierarchy, so we have to add space for it. */
5804 /* If the first virtual base might have been placed at a
5805 lower address, had we started from CLASSTYPE_SIZE, rather
5806 than TYPE_SIZE, issue a warning. There can be both false
5807 positives and false negatives from this warning in rare
5808 cases; to deal with all the possibilities would probably
5809 require performing both layout algorithms and comparing
5810 the results which is not particularly tractable. */
5812 && first_vbase
5813 && (tree_int_cst_lt
5818 bitsize_unit_node),
5821 "offset of virtual base %qT is not ABI-compliant and "
5823 basetype);
5826 }
5827 }
5828 }
5830 /* Returns the offset of the byte just past the end of the base class
5831 BINFO. */
5833 static tree
5835 {
5836 tree size;
5841 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5842 allocate some space for it. It cannot have virtual bases, so
5843 TYPE_SIZE_UNIT is fine. */
5845 else
5849 }
5851 /* Returns the offset of the byte just past the end of the base class
5852 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5853 only non-virtual bases are included. */
5855 static tree
5857 {
5860 tree binfo;
5861 tree base_binfo;
5862 tree offset;
5867 {
5877 }
5879 /* G++ 3.2 did not check indirect virtual bases. */
5883 {
5887 }
5890 }
5892 /* Warn about bases of T that are inaccessible because they are
5893 ambiguous. For example:
5895 struct S {};
5896 struct T : public S {};
5897 struct U : public S, public T {};
5899 Here, `(S*) new U' is not allowed because there are two `S'
5900 subobjects of U. */
5902 static void
5904 {
5907 tree basetype;
5908 tree binfo;
5909 tree base_binfo;
5911 /* If there are no repeated bases, nothing can be ambiguous. */
5915 /* Check direct bases. */
5918 {
5924 }
5926 /* Check for ambiguous virtual bases. */
5930 {
5936 }
5937 }
5939 /* Compare two INTEGER_CSTs K1 and K2. */
5941 static int
5943 {
5945 }
5947 /* Increase the size indicated in RLI to account for empty classes
5948 that are "off the end" of the class. */
5950 static void
5952 {
5953 tree eoc;
5954 tree rli_size;
5956 /* It might be the case that we grew the class to allocate a
5957 zero-sized base class. That won't be reflected in RLI, yet,
5958 because we are willing to overlay multiple bases at the same
5959 offset. However, now we need to make sure that RLI is big enough
5960 to reflect the entire class. */
5966 {
5968 /* In version 1 of the ABI, the size of a class that ends with
5969 a bitfield was not rounded up to a whole multiple of a
5970 byte. Because rli_size_unit_so_far returns only the number
5971 of fully allocated bytes, any extra bits were not included
5972 in the size. */
5974 else
5975 /* The size should have been rounded to a whole byte. */
5978 rli->bitpos
5987 }
5988 }
5990 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5991 BINFO_OFFSETs for all of the base-classes. Position the vtable
5992 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5994 static void
5996 {
5997 tree non_static_data_members;
5998 tree field;
5999 tree vptr;
6000 record_layout_info rli;
6001 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6002 types that appear at that offset. */
6003 splay_tree empty_base_offsets;
6004 /* True if the last field laid out was a bit-field. */
6006 /* The location at which the next field should be inserted. */
6008 /* T, as a base class. */
6009 tree base_t;
6011 /* Keep track of the first non-static data member. */
6014 /* Start laying out the record. */
6017 /* Mark all the primary bases in the hierarchy. */
6020 /* Create a pointer to our virtual function table. */
6023 /* The vptr is always the first thing in the class. */
6025 {
6030 }
6031 else
6034 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6039 /* Layout the non-static data members. */
6041 {
6042 tree type;
6043 tree padding;
6045 /* We still pass things that aren't non-static data members to
6046 the back end, in case it wants to do something with them. */
6048 {
6050 /* If the static data member has incomplete type, keep track
6051 of it so that it can be completed later. (The handling
6052 of pending statics in finish_record_layout is
6053 insufficient; consider:
6055 struct S1;
6056 struct S2 { static S1 s1; };
6058 At this point, finish_record_layout will be called, but
6059 S1 is still incomplete.) */
6061 {
6063 /* The visibility of static data members is determined
6064 at their point of declaration, not their point of
6065 definition. */
6067 }
6069 }
6077 /* If this field is a bit-field whose width is greater than its
6078 type, then there are some special rules for allocating
6079 it. */
6082 {
6084 tree integer_type;
6086 /* We must allocate the bits as if suitably aligned for the
6087 longest integer type that fits in this many bits. type
6088 of the field. Then, we are supposed to use the left over
6089 bits as additional padding. */
6098 /* ITK now indicates a type that is too large for the
6099 field. We have to back up by one to find the largest
6100 type that fits. */
6101 do
6102 {
6107 /* Figure out how much additional padding is required. GCC
6108 3.2 always created a padding field, even if it had zero
6109 width. */
6112 {
6114 /* In a union, the padding field must have the full width
6115 of the bit-field; all fields start at offset zero. */
6117 else
6118 {
6121 "ABI-compliant and may change in a future "
6123 t);
6126 }
6127 }
6128 #ifdef PCC_BITFIELD_TYPE_MATTERS
6129 /* An unnamed bitfield does not normally affect the
6130 alignment of the containing class on a target where
6131 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6132 make any exceptions for unnamed bitfields when the
6133 bitfields are longer than their types. Therefore, we
6134 temporarily give the field a name. */
6136 {
6139 }
6140 #endif
6145 empty_base_offsets);
6148 /* Now that layout has been performed, set the size of the
6149 field to the size of its declared type; the rest of the
6150 field is effectively invisible. */
6152 /* We must also reset the DECL_MODE of the field. */
6157 /* Versions of G++ before G++ 3.4 did not reset the
6158 DECL_MODE. */
6160 "the offset of %qD may not be ABI-compliant and may "
6162 }
6163 else
6165 empty_base_offsets);
6167 /* Remember the location of any empty classes in FIELD. */
6171 empty_base_offsets,
6174 /* If a bit-field does not immediately follow another bit-field,
6175 and yet it starts in the middle of a byte, we have failed to
6176 comply with the ABI. */
6179 /* The TREE_NO_WARNING flag gets set by Objective-C when
6180 laying out an Objective-C class. The ObjC ABI differs
6181 from the C++ ABI, and so we do not want a warning
6182 here. */
6184 && !last_field_was_bitfield
6187 bitsize_unit_node)))
6191 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6192 offset of the field. */
6199 "classes to be placed at different locations in a "
6202 /* The middle end uses the type of expressions to determine the
6203 possible range of expression values. In order to optimize
6204 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6205 must be made aware of the width of "i", via its type.
6207 Because C++ does not have integer types of arbitrary width,
6208 we must (for the purposes of the front end) convert from the
6209 type assigned here to the declared type of the bitfield
6210 whenever a bitfield expression is used as an rvalue.
6211 Similarly, when assigning a value to a bitfield, the value
6212 must be converted to the type given the bitfield here. */
6214 {
6219 {
6226 }
6227 }
6229 /* If we needed additional padding after this field, add it
6230 now. */
6232 {
6233 tree padding_field;
6236 FIELD_DECL,
6237 NULL_TREE,
6238 char_type_node);
6245 NULL_TREE,
6246 empty_base_offsets);
6247 }
6250 }
6253 {
6254 /* Make sure that we are on a byte boundary so that the size of
6255 the class without virtual bases will always be a round number
6256 of bytes. */
6259 }
6261 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6262 padding. */
6266 /* Delete all zero-width bit-fields from the list of fields. Now
6267 that the type is laid out they are no longer important. */
6270 /* Create the version of T used for virtual bases. We do not use
6271 make_class_type for this version; this is an artificial type. For
6272 a POD type, we just reuse T. */
6274 {
6277 /* Set the size and alignment for the new type. In G++ 3.2, all
6278 empty classes were considered to have size zero when used as
6279 base classes. */
6281 {
6286 "layout of classes derived from empty class %qT "
6288 t);
6289 }
6290 else
6291 {
6292 tree eoc;
6294 /* If the ABI version is not at least two, and the last
6295 field was a bit-field, RLI may not be on a byte
6296 boundary. In particular, rli_size_unit_so_far might
6297 indicate the last complete byte, while rli_size_so_far
6298 indicates the total number of bits used. Therefore,
6299 rli_size_so_far, rather than rli_size_unit_so_far, is
6300 used to compute TYPE_SIZE_UNIT. */
6308 eoc);
6315 }
6319 /* Copy the fields from T. */
6323 {
6325 FIELD_DECL,
6335 }
6337 /* Record the base version of the type. */
6340 }
6341 else
6344 /* Every empty class contains an empty class. */
6348 /* Set the TYPE_DECL for this type to contain the right
6349 value for DECL_OFFSET, so that we can use it as part
6350 of a COMPONENT_REF for multiple inheritance. */
6353 /* Now fix up any virtual base class types that we left lying
6354 around. We must get these done before we try to lay out the
6355 virtual function table. As a side-effect, this will remove the
6356 base subobject fields. */
6359 /* Make sure that empty classes are reflected in RLI at this
6360 point. */
6363 /* Make sure not to create any structures with zero size. */
6369 /* If this is a non-POD, declaring it packed makes a difference to how it
6370 can be used as a field; don't let finalize_record_size undo it. */
6374 /* Let the back end lay out the type. */
6383 /* Warn about bases that can't be talked about due to ambiguity. */
6386 /* Now that we're done with layout, give the base fields the real types. */
6391 /* Clean up. */
6398 }
6400 /* Determine the "key method" for the class type indicated by TYPE,
6401 and set CLASSTYPE_KEY_METHOD accordingly. */
6403 void
6405 {
6406 tree method;
6409 || processing_template_decl
6414 /* The key method is the first non-pure virtual function that is not
6415 inline at the point of class definition. On some targets the
6416 key function may not be inline; those targets should not call
6417 this function until the end of the translation unit. */
6423 {
6426 }
6429 }
6432 /* Allocate and return an instance of struct sorted_fields_type with
6433 N fields. */
6437 {
6444 }
6447 /* Perform processing required when the definition of T (a class type)
6448 is complete. */
6450 void
6452 {
6453 tree x;
6454 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6458 {
6463 }
6465 /* If this type was previously laid out as a forward reference,
6466 make sure we lay it out again. */
6470 /* Make assumptions about the class; we'll reset the flags if
6471 necessary. */
6477 /* Do end-of-class semantic processing: checking the validity of the
6478 bases and members and add implicitly generated methods. */
6481 /* Find the key method. */
6483 {
6484 /* The Itanium C++ ABI permits the key method to be chosen when
6485 the class is defined -- even though the key method so
6486 selected may later turn out to be an inline function. On
6487 some systems (such as ARM Symbian OS) the key method cannot
6488 be determined until the end of the translation unit. On such
6489 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6490 will cause the class to be added to KEYED_CLASSES. Then, in
6491 finish_file we will determine the key method. */
6495 /* If a polymorphic class has no key method, we may emit the vtable
6496 in every translation unit where the class definition appears. */
6499 }
6501 /* Layout the class itself. */
6504 /* We use the base type for trivial assignments, and hence it
6505 needs a mode. */
6510 /* If necessary, create the primary vtable for this class. */
6512 {
6513 /* We must enter these virtuals into the table. */
6517 /* Here we know enough to change the type of our virtual
6518 function table, but we will wait until later this function. */
6521 /* If we're warning about ABI tags, check the types of the new
6522 virtual functions. */
6526 }
6529 {
6531 tree fn;
6538 /* Add entries for virtual functions introduced by this class. */
6542 /* Set DECL_VINDEX for all functions declared in this class. */
6544 fn;
6546 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6548 {
6552 /* A thunk. We should never be calling this entry directly
6553 from this vtable -- we'd use the entry for the non
6554 thunk base function. */
6558 }
6559 }
6564 /* Complete the rtl for any static member objects of the type we're
6565 working on. */
6572 /* Done with FIELDS...now decide whether to sort these for
6573 faster lookups later.
6575 We use a small number because most searches fail (succeeding
6576 ultimately as the search bores through the inheritance
6577 hierarchy), and we want this failure to occur quickly. */
6581 /* Complain if one of the field types requires lower visibility. */
6584 /* Make the rtl for any new vtables we have created, and unmark
6585 the base types we marked. */
6588 /* Build the VTT for T. */
6591 /* This warning does not make sense for Java classes, since they
6592 cannot have destructors. */
6594 {
6595 tree dtor;
6599 if it were virtual, we would have created it by now. */
6600 !dtor
6609 "%q#T has virtual functions and accessible"
6611 }
6618 /* Class layout, assignment of virtual table slots, etc., is now
6619 complete. Give the back end a chance to tweak the visibility of
6620 the class or perform any other required target modifications. */
6630 /* Finish debugging output for this type. */
6634 {
6637 {
6640 }
6642 {
6645 else
6646 {
6649 }
6651 }
6653 {
6655 "the type of the first field has a different ABI from the "
6658 }
6659 }
6660 }
6662 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6663 equal to THRESHOLD or greater than THRESHOLD. */
6665 static void
6667 {
6670 {
6675 }
6676 }
6678 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6680 void
6682 {
6685 {
6687 int n_fields
6698 }
6699 }
6701 /* When T was built up, the member declarations were added in reverse
6702 order. Rearrange them to declaration order. */
6704 void
6706 {
6707 tree next;
6708 tree prev;
6709 tree x;
6711 /* The following lists are all in reverse order. Put them in
6712 declaration order now. */
6716 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6717 reverse order, so we can't just use nreverse. */
6722 {
6726 }
6728 {
6732 }
6733 }
6735 tree
6737 {
6740 /* Now that we've got all the field declarations, reverse everything
6741 as necessary. */
6746 /* Nadger the current location so that diagnostics point to the start of
6747 the struct, not the end. */
6751 {
6752 tree x;
6758 /* We need to emit an error message if this type was used as a parameter
6759 and it is an abstract type, even if it is a template. We construct
6760 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6761 account and we call complete_vars with this type, which will check
6762 the PARM_DECLS. Note that while the type is being defined,
6763 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6764 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6770 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6771 an enclosing scope is a template class, so that this function be
6772 found by lookup_fnfields_1 when the using declaration is not
6773 instantiated yet. */
6776 {
6781 }
6783 /* Remember current #pragma pack value. */
6786 /* Fix up any variants we've already built. */
6788 {
6793 }
6794 }
6795 else
6804 else
6808 /* Lambdas are defined by the LAMBDA_EXPR. */
6813 }
6814 \f
6815 /* Hash table to avoid endless recursion when handling references. */
6818 /* Return the dynamic type of INSTANCE, if known.
6819 Used to determine whether the virtual function table is needed
6820 or not.
6822 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6823 of our knowledge of its type. *NONNULL should be initialized
6824 before this function is called. */
6826 static tree
6828 {
6829 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6832 {
6836 else
6840 /* This is a call to a constructor, hence it's never zero. */
6842 {
6846 }
6850 /* This is a call to a constructor, hence it's never zero. */
6852 {
6856 }
6865 /* Propagate nonnull. */
6870 CASE_CONVERT:
6876 {
6877 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6878 with a real object -- given &p->f, p can still be null. */
6880 /* ??? Probably should check DECL_WEAK here. */
6883 }
6887 /* If this component is really a base class reference, then the field
6888 itself isn't definitive. */
6897 {
6901 }
6902 /* fall through... */
6907 {
6911 }
6913 {
6917 /* if we're in a ctor or dtor, we know our type. If
6918 current_class_ptr is set but we aren't in a function, we're in
6919 an NSDMI (and therefore a constructor). */
6924 {
6928 }
6929 }
6931 {
6932 /* We only need one hash table because it is always left empty. */
6936 /* Reference variables should be references to objects. */
6940 /* Enter the INSTANCE in a table to prevent recursion; a
6941 variable's initializer may refer to the variable
6942 itself. */
6947 {
6948 tree type;
6957 }
6958 }
6963 }
6964 #undef RECUR
6965 }
6967 /* Return nonzero if the dynamic type of INSTANCE is known, and
6968 equivalent to the static type. We also handle the case where
6969 INSTANCE is really a pointer. Return negative if this is a
6970 ctor/dtor. There the dynamic type is known, but this might not be
6971 the most derived base of the original object, and hence virtual
6972 bases may not be laid out according to this type.
6974 Used to determine whether the virtual function table is needed
6975 or not.
6977 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6978 of our knowledge of its type. *NONNULL should be initialized
6979 before this function is called. */
6981 int
6983 {
6986 tree fixed;
6988 /* processing_template_decl can be false in a template if we're in
6989 fold_non_dependent_expr, but we still want to suppress this check. */
6991 {
6992 /* In a template we only care about the type of the result. */
6996 }
7006 }
7008 \f
7009 void
7011 {
7014 current_class_stack
7022 }
7024 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7026 static void
7028 {
7029 tree type;
7031 /* We are re-entering the same class we just left, so we don't
7032 have to search the whole inheritance matrix to find all the
7033 decls to bind again. Instead, we install the cached
7034 class_shadowed list and walk through it binding names. */
7037 /* Restore IDENTIFIER_TYPE_VALUE. */
7039 type;
7042 }
7044 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7045 appropriate for TYPE.
7047 So that we may avoid calls to lookup_name, we cache the _TYPE
7048 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7050 For multiple inheritance, we perform a two-pass depth-first search
7051 of the type lattice. */
7053 void
7055 {
7056 class_stack_node_t csn;
7060 /* Make sure there is enough room for the new entry on the stack. */
7062 {
7064 current_class_stack
7066 current_class_stack_size);
7067 }
7069 /* Insert a new entry on the class stack. */
7076 current_class_depth++;
7078 /* Now set up the new type. */
7084 /* By default, things in classes are private, while things in
7085 structures or unions are public. */
7087 ? access_private_node
7093 {
7094 /* Forcibly remove any old class remnants. */
7096 }
7102 else
7104 }
7106 /* When we exit a toplevel class scope, we save its binding level so
7107 that we can restore it quickly. Here, we've entered some other
7108 class, so we must invalidate our cache. */
7110 void
7112 {
7114 }
7116 /* Get out of the current class scope. If we were in a class scope
7117 previously, that is the one popped to. */
7119 void
7121 {
7124 current_class_depth--;
7130 }
7132 /* Mark the top of the class stack as hidden. */
7134 void
7136 {
7139 }
7141 /* Mark the top of the class stack as un-hidden. */
7143 void
7145 {
7148 }
7150 /* Returns 1 if the class type currently being defined is either T or
7151 a nested type of T. */
7153 bool
7155 {
7163 /* We start looking from 1 because entry 0 is from global scope,
7164 and has no type. */
7166 {
7167 tree c;
7170 else
7171 {
7175 }
7180 }
7182 }
7184 /* If either current_class_type or one of its enclosing classes are derived
7185 from T, return the appropriate type. Used to determine how we found
7186 something via unqualified lookup. */
7188 tree
7190 {
7193 /* The bases of a dependent type are unknown. */
7204 {
7209 }
7212 }
7214 /* Returns the innermost class type which is not a lambda closure type. */
7216 tree
7218 {
7221 /* We start looking from 1 because entry 0 is from global scope,
7222 and has no type. */
7224 {
7225 tree c;
7228 else
7229 {
7233 }
7238 }
7240 }
7242 /* When entering a class scope, all enclosing class scopes' names with
7243 static meaning (static variables, static functions, types and
7244 enumerators) have to be visible. This recursive function calls
7245 pushclass for all enclosing class contexts until global or a local
7246 scope is reached. TYPE is the enclosed class. */
7248 void
7250 {
7251 /* A namespace might be passed in error cases, like A::B:C. */
7259 }
7261 /* Undoes a push_nested_class call. */
7263 void
7265 {
7271 }
7273 /* Returns the number of extern "LANG" blocks we are nested within. */
7275 int
7277 {
7279 }
7281 /* Set global variables CURRENT_LANG_NAME to appropriate value
7282 so that behavior of name-mangling machinery is correct. */
7284 void
7286 {
7290 {
7292 }
7294 {
7296 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7297 (See record_builtin_java_type in decl.c.) However, that causes
7298 incorrect debug entries if these types are actually used.
7299 So we re-enable debug output after extern "Java". */
7308 }
7310 {
7312 }
7313 else
7315 }
7317 /* Get out of the current language scope. */
7319 void
7321 {
7323 }
7324 \f
7325 /* Type instantiation routines. */
7327 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7328 matches the TARGET_TYPE. If there is no satisfactory match, return
7329 error_mark_node, and issue an error & warning messages under
7330 control of FLAGS. Permit pointers to member function if FLAGS
7331 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7332 a template-id, and EXPLICIT_TARGS are the explicitly provided
7333 template arguments.
7335 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7336 is the base path used to reference those member functions. If
7337 the address is resolved to a member function, access checks will be
7338 performed and errors issued if appropriate. */
7340 static tree
7342 tree overload,
7343 tsubst_flags_t flags,
7345 tree explicit_targs,
7346 tree access_path)
7347 {
7348 /* Here's what the standard says:
7350 [over.over]
7352 If the name is a function template, template argument deduction
7353 is done, and if the argument deduction succeeds, the deduced
7354 arguments are used to generate a single template function, which
7355 is added to the set of overloaded functions considered.
7357 Non-member functions and static member functions match targets of
7358 type "pointer-to-function" or "reference-to-function." Nonstatic
7359 member functions match targets of type "pointer-to-member
7360 function;" the function type of the pointer to member is used to
7361 select the member function from the set of overloaded member
7362 functions. If a nonstatic member function is selected, the
7363 reference to the overloaded function name is required to have the
7364 form of a pointer to member as described in 5.3.1.
7366 If more than one function is selected, any template functions in
7367 the set are eliminated if the set also contains a non-template
7368 function, and any given template function is eliminated if the
7369 set contains a second template function that is more specialized
7370 than the first according to the partial ordering rules 14.5.5.2.
7371 After such eliminations, if any, there shall remain exactly one
7372 selected function. */
7375 /* We store the matches in a TREE_LIST rooted here. The functions
7376 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7377 interoperability with most_specialized_instantiation. */
7379 tree fn;
7380 tree target_fn_type;
7382 /* By the time we get here, we should be seeing only real
7383 pointer-to-member types, not the internal POINTER_TYPE to
7384 METHOD_TYPE representation. */
7390 /* Check that the TARGET_TYPE is reasonable. */
7395 /* This is OK, too. */
7398 /* This is OK, too. This comes from a conversion to reference
7399 type. */
7401 else
7402 {
7408 }
7410 /* Non-member functions and static member functions match targets of type
7411 "pointer-to-function" or "reference-to-function." Nonstatic member
7412 functions match targets of type "pointer-to-member-function;" the
7413 function type of the pointer to member is used to select the member
7414 function from the set of overloaded member functions.
7416 So figure out the FUNCTION_TYPE that we want to match against. */
7419 /* If we can find a non-template function that matches, we can just
7420 use it. There's no point in generating template instantiations
7421 if we're just going to throw them out anyhow. But, of course, we
7422 can only do this when we don't *need* a template function. */
7424 {
7425 tree fns;
7428 {
7432 /* We're not looking for templates just yet. */
7437 /* We're looking for a non-static member, and this isn't
7438 one, or vice versa. */
7441 /* Ignore functions which haven't been explicitly
7442 declared. */
7446 /* See if there's a match. */
7449 }
7450 }
7452 /* Now, if we've already got a match (or matches), there's no need
7453 to proceed to the template functions. But, if we don't have a
7454 match we need to look at them, too. */
7456 {
7457 tree target_arg_types;
7458 tree target_ret_type;
7459 tree fns;
7462 tree arg;
7476 {
7478 tree instantiation;
7479 tree targs;
7482 /* We're only looking for templates. */
7487 /* We're not looking for a non-static member, and this is
7488 one, or vice versa. */
7493 /* If the template has a deduced return type, don't expose it to
7494 template argument deduction. */
7498 /* Try to do argument deduction. */
7505 /* Instantiation failed. */
7508 /* And now force instantiation to do return type deduction. */
7510 {
7516 }
7518 /* See if there's a match. */
7521 }
7523 /* Now, remove all but the most specialized of the matches. */
7525 {
7530 NULL_TREE,
7531 NULL_TREE);
7532 }
7533 }
7535 /* Now we should have exactly one function in MATCHES. */
7537 {
7538 /* There were *no* matches. */
7540 {
7543 target_type);
7546 }
7548 }
7550 {
7551 /* There were too many matches. First check if they're all
7552 the same function. */
7557 /* For multi-versioned functions, more than one match is just fine and
7558 decls_match will return false as they are different. */
7566 {
7568 {
7571 target_type);
7573 /* Since print_candidates expects the functions in the
7574 TREE_VALUE slot, we flip them here. */
7579 }
7582 }
7583 }
7585 /* Good, exactly one match. Now, convert it to the correct type. */
7590 {
7598 {
7601 }
7602 }
7604 /* If a pointer to a function that is multi-versioned is requested, the
7605 pointer to the dispatcher function is returned instead. This works
7606 well because indirectly calling the function will dispatch the right
7607 function version at run-time. */
7609 {
7613 /* Mark all the versions corresponding to the dispatcher as used. */
7616 }
7618 /* If we're doing overload resolution purely for the purpose of
7619 determining conversion sequences, we should not consider the
7620 function used. If this conversion sequence is selected, the
7621 function will be marked as used at this point. */
7623 {
7624 /* Make =delete work with SFINAE. */
7629 }
7631 /* We could not check access to member functions when this
7632 expression was originally created since we did not know at that
7633 time to which function the expression referred. */
7635 {
7638 }
7642 else
7643 {
7644 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7645 will mark the function as addressed, but here we must do it
7646 explicitly. */
7650 }
7651 }
7653 /* This function will instantiate the type of the expression given in
7654 RHS to match the type of LHSTYPE. If errors exist, then return
7655 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7656 we complain on errors. If we are not complaining, never modify rhs,
7657 as overload resolution wants to try many possible instantiations, in
7658 the hope that at least one will work.
7660 For non-recursive calls, LHSTYPE should be a function, pointer to
7661 function, or a pointer to member function. */
7663 tree
7665 {
7672 {
7676 }
7679 {
7686 /* Microsoft allows `A::f' to be resolved to a
7687 pointer-to-member. */
7688 ;
7689 else
7690 {
7695 }
7696 }
7699 {
7702 }
7704 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7705 deduce any type information. */
7707 {
7711 }
7713 /* There only a few kinds of expressions that may have a type
7714 dependent on overload resolution. */
7720 /* This should really only be used when attempting to distinguish
7721 what sort of a pointer to function we have. For now, any
7722 arithmetic operation which is not supported on pointers
7723 is rejected as an error. */
7726 {
7728 {
7734 /* Do not lose object's side effects. */
7738 }
7745 /* This can happen if we are forming a pointer-to-member for a
7746 member template. */
7749 /* Fall through. */
7752 {
7756 return
7760 }
7764 return
7768 access_path);
7771 {
7776 }
7783 }
7785 }
7786 \f
7787 /* Return the name of the virtual function pointer field
7788 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7789 this may have to look back through base types to find the
7790 ultimate field name. (For single inheritance, these could
7791 all be the same name. Who knows for multiple inheritance). */
7793 static tree
7795 {
7802 {
7808 }
7816 }
7818 void
7820 {
7827 {
7832 }
7833 }
7835 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7836 according to [class]:
7837 The class-name is also inserted
7838 into the scope of the class itself. For purposes of access checking,
7839 the inserted class name is treated as if it were a public member name. */
7841 void
7843 {
7846 tree saved_cas;
7861 }
7863 /* Returns 1 if TYPE contains only padding bytes. */
7865 int
7867 {
7874 /* In G++ 3.2, whether or not a class was empty was determined by
7875 looking at its size. */
7878 else
7880 }
7882 /* Returns true if TYPE contains an empty class. */
7884 static bool
7886 {
7890 {
7891 tree field;
7892 tree binfo;
7893 tree base_binfo;
7905 }
7909 }
7911 /* Returns true if TYPE contains no actual data, just various
7912 possible combinations of empty classes and possibly a vptr. */
7914 bool
7916 {
7918 {
7919 tree field;
7920 tree binfo;
7921 tree base_binfo;
7924 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7925 out, but we'd like to be able to check this before then. */
7939 }
7943 }
7945 /* Note that NAME was looked up while the current class was being
7946 defined and that the result of that lookup was DECL. */
7948 void
7950 {
7951 splay_tree names_used;
7953 /* If we're not defining a class, there's nothing to do. */
7959 /* If there's already a binding for this NAME, then we don't have
7960 anything to worry about. */
7973 }
7975 /* Note that NAME was declared (as DECL) in the current class. Check
7976 to see that the declaration is valid. */
7978 void
7980 {
7981 splay_tree names_used;
7982 splay_tree_node n;
7984 /* Look to see if we ever used this name. */
7985 names_used
7989 /* The C language allows members to be declared with a type of the same
7990 name, and the C++ standard says this diagnostic is not required. So
7991 allow it in extern "C" blocks unless predantic is specified.
7992 Allow it in all cases if -ms-extensions is specified. */
7998 {
7999 /* [basic.scope.class]
8001 A name N used in a class S shall refer to the same declaration
8002 in its context and when re-evaluated in the completed scope of
8003 S. */
8007 }
8008 }
8010 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8011 Secondary vtables are merged with primary vtables; this function
8012 will return the VAR_DECL for the primary vtable. */
8014 tree
8016 {
8017 tree decl;
8021 {
8024 }
8028 }
8031 /* Returns the binfo for the primary base of BINFO. If the resulting
8032 BINFO is a virtual base, and it is inherited elsewhere in the
8033 hierarchy, then the returned binfo might not be the primary base of
8034 BINFO in the complete object. Check BINFO_PRIMARY_P or
8035 BINFO_LOST_PRIMARY_P to be sure. */
8037 static tree
8039 {
8040 tree primary_base;
8047 }
8049 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8051 static int
8053 {
8057 }
8059 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8060 INDENT should be zero when called from the top level; it is
8061 incremented recursively. IGO indicates the next expected BINFO in
8062 inheritance graph ordering. */
8064 static tree
8067 tree binfo,
8068 tree igo,
8070 {
8072 tree base_binfo;
8080 {
8083 }
8098 {
8102 TFF_PLAIN_IDENTIFIER),
8104 }
8106 {
8109 }
8114 {
8118 {
8122 TFF_PLAIN_IDENTIFIER));
8123 }
8125 {
8129 TFF_PLAIN_IDENTIFIER));
8130 }
8132 {
8136 TFF_PLAIN_IDENTIFIER));
8137 }
8139 {
8143 TFF_PLAIN_IDENTIFIER));
8144 }
8148 }
8154 }
8156 /* Dump the BINFO hierarchy for T. */
8158 static void
8160 {
8172 }
8174 /* Debug interface to hierarchy dumping. */
8176 void
8178 {
8180 }
8182 static void
8184 {
8189 {
8192 }
8193 }
8195 static void
8197 {
8198 tree value;
8200 HOST_WIDE_INT elt;
8208 TFF_PLAIN_IDENTIFIER));
8215 }
8217 static void
8219 {
8227 {
8234 {
8239 }
8243 }
8246 }
8248 static void
8250 {
8258 {
8263 }
8266 }
8268 /* Dump a function or thunk and its thunkees. */
8270 static void
8272 {
8275 tree thunks;
8283 {
8293 else
8299 }
8303 }
8305 /* Dump the thunks for FN. */
8307 void
8309 {
8311 }
8313 /* Virtual function table initialization. */
8315 /* Create all the necessary vtables for T and its base classes. */
8317 static void
8319 {
8320 tree vbase;
8324 /* We lay out the primary and secondary vtables in one contiguous
8325 vtable. The primary vtable is first, followed by the non-virtual
8326 secondary vtables in inheritance graph order. */
8330 /* Then come the virtual bases, also in inheritance graph order. */
8332 {
8336 }
8340 }
8342 /* Initialize the vtable for BINFO with the INITS. */
8344 static void
8346 {
8347 tree decl;
8353 }
8355 /* Build the VTT (virtual table table) for T.
8356 A class requires a VTT if it has virtual bases.
8358 This holds
8359 1 - primary virtual pointer for complete object T
8360 2 - secondary VTTs for each direct non-virtual base of T which requires a
8361 VTT
8362 3 - secondary virtual pointers for each direct or indirect base of T which
8363 has virtual bases or is reachable via a virtual path from T.
8364 4 - secondary VTTs for each direct or indirect virtual base of T.
8366 Secondary VTTs look like complete object VTTs without part 4. */
8368 static void
8370 {
8371 tree type;
8372 tree vtt;
8373 tree index;
8376 /* Build up the initializers for the VTT. */
8381 /* If we didn't need a VTT, we're done. */
8385 /* Figure out the type of the VTT. */
8389 /* Now, build the VTT object itself. */
8392 /* Add the VTT to the vtables list. */
8397 }
8399 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8400 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8401 and CHAIN the vtable pointer for this binfo after construction is
8402 complete. VALUE can also be another BINFO, in which case we recurse. */
8404 static tree
8406 {
8407 tree vt;
8410 {
8416 else
8418 }
8421 }
8423 /* Data for secondary VTT initialization. */
8425 {
8426 /* Is this the primary VTT? */
8429 /* Current index into the VTT. */
8430 tree index;
8432 /* Vector of initializers built up. */
8435 /* The type being constructed by this secondary VTT. */
8436 tree type_being_constructed;
8439 /* Recursively build the VTT-initializer for BINFO (which is in the
8440 hierarchy dominated by T). INITS points to the end of the initializer
8441 list to date. INDEX is the VTT index where the next element will be
8442 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8443 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8444 for virtual bases of T. When it is not so, we build the constructor
8445 vtables for the BINFO-in-T variant. */
8447 static void
8450 {
8452 tree b;
8453 tree init;
8454 secondary_vptr_vtt_init_data data;
8457 /* We only need VTTs for subobjects with virtual bases. */
8461 /* We need to use a construction vtable if this is not the primary
8462 VTT. */
8464 {
8467 /* Record the offset in the VTT where this sub-VTT can be found. */
8469 }
8471 /* Add the address of the primary vtable for the complete object. */
8475 {
8478 }
8481 /* Recursively add the secondary VTTs for non-virtual bases. */
8486 /* Add secondary virtual pointers for all subobjects of BINFO with
8487 either virtual bases or reachable along a virtual path, except
8488 subobjects that are non-virtual primary bases. */
8498 /* data.inits might have grown as we added secondary virtual pointers.
8499 Make sure our caller knows about the new vector. */
8503 /* Add the secondary VTTs for virtual bases in inheritance graph
8504 order. */
8506 {
8511 }
8512 else
8513 /* Remove the ctor vtables we created. */
8515 }
8517 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8518 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8520 static tree
8522 {
8525 /* We don't care about bases that don't have vtables. */
8529 /* We're only interested in proper subobjects of the type being
8530 constructed. */
8534 /* We're only interested in bases with virtual bases or reachable
8535 via a virtual path from the type being constructed. */
8540 /* We're not interested in non-virtual primary bases. */
8544 /* Record the index where this secondary vptr can be found. */
8546 {
8551 {
8552 /* It's a primary virtual base, and this is not a
8553 construction vtable. Find the base this is primary of in
8554 the inheritance graph, and use that base's vtable
8555 now. */
8558 }
8559 }
8561 /* Add the initializer for the secondary vptr itself. */
8564 /* Advance the vtt index. */
8569 }
8571 /* Called from build_vtt_inits via dfs_walk. After building
8572 constructor vtables and generating the sub-vtt from them, we need
8573 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8574 binfo of the base whose sub vtt was generated. */
8576 static tree
8578 {
8582 /* If this class has no vtable, none of its bases do. */
8586 /* This might be a primary base, so have no vtable in this
8587 hierarchy. */
8590 /* If we scribbled the construction vtable vptr into BINFO, clear it
8591 out now. */
8597 }
8599 /* Build the construction vtable group for BINFO which is in the
8600 hierarchy dominated by T. */
8602 static void
8604 {
8605 tree type;
8606 tree vtbl;
8607 tree id;
8608 tree vbase;
8611 /* See if we've already created this construction vtable group. */
8617 /* Build a version of VTBL (with the wrong type) for use in
8618 constructing the addresses of secondary vtables in the
8619 construction vtable group. */
8622 /* Don't export construction vtables from shared libraries. Even on
8623 targets that don't support hidden visibility, this tells
8624 can_refer_decl_in_current_unit_p not to assume that it's safe to
8625 access from a different compilation unit (bz 54314). */
8633 /* Add the vtables for each of our virtual bases using the vbase in T
8634 binfo. */
8636 vbase;
8638 {
8639 tree b;
8646 }
8648 /* Figure out the type of the construction vtable. */
8655 /* Initialize the construction vtable. */
8659 }
8661 /* Add the vtbl initializers for BINFO (and its bases other than
8662 non-virtual primaries) to the list of INITS. BINFO is in the
8663 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8664 the constructor the vtbl inits should be accumulated for. (If this
8665 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8666 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8667 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8668 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8669 but are not necessarily the same in terms of layout. */
8671 static void
8673 tree orig_binfo,
8674 tree rtti_binfo,
8675 tree vtbl,
8676 tree t,
8678 {
8680 tree base_binfo;
8685 /* If it doesn't have a vptr, we don't do anything. */
8689 /* If we're building a construction vtable, we're not interested in
8690 subobjects that don't require construction vtables. */
8696 /* Build the initializers for the BINFO-in-T vtable. */
8699 /* Walk the BINFO and its bases. We walk in preorder so that as we
8700 initialize each vtable we can figure out at what offset the
8701 secondary vtable lies from the primary vtable. We can't use
8702 dfs_walk here because we need to iterate through bases of BINFO
8703 and RTTI_BINFO simultaneously. */
8705 {
8706 /* Skip virtual bases. */
8712 inits);
8713 }
8714 }
8716 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8717 BINFO vtable to L. */
8719 static void
8721 tree orig_binfo,
8722 tree rtti_binfo,
8723 tree orig_vtbl,
8724 tree t,
8726 {
8733 {
8734 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8735 primary virtual base. If it is not the same primary in
8736 the hierarchy of T, we'll need to generate a ctor vtable
8737 for it, to place at its location in T. If it is the same
8738 primary, we still need a VTT entry for the vtable, but it
8739 should point to the ctor vtable for the base it is a
8740 primary for within the sub-hierarchy of RTTI_BINFO.
8742 There are three possible cases:
8744 1) We are in the same place.
8745 2) We are a primary base within a lost primary virtual base of
8746 RTTI_BINFO.
8747 3) We are primary to something not a base of RTTI_BINFO. */
8749 tree b;
8752 /* First, look through the bases we are primary to for RTTI_BINFO
8753 or a virtual base. */
8756 {
8761 }
8762 /* If we run out of primary links, keep looking down our
8763 inheritance chain; we might be an indirect primary. */
8767 found:
8769 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8770 base B and it is a base of RTTI_BINFO, this is case 2. In
8771 either case, we share our vtable with LAST, i.e. the
8772 derived-most base within B of which we are a primary. */
8775 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8776 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8777 binfo_ctor_vtable after everything's been set up. */
8780 /* Otherwise, this is case 3 and we get our own. */
8781 }
8788 {
8789 tree index;
8792 /* Add the initializer for this vtable. */
8796 /* Figure out the position to which the VPTR should point. */
8802 }
8805 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8806 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8807 straighten this out. */
8810 /* Throw away any unneeded intializers. */
8812 else
8813 /* For an ordinary vtable, set BINFO_VTABLE. */
8815 }
8819 /* Construct the initializer for BINFO's virtual function table. BINFO
8820 is part of the hierarchy dominated by T. If we're building a
8821 construction vtable, the ORIG_BINFO is the binfo we should use to
8822 find the actual function pointers to put in the vtable - but they
8823 can be overridden on the path to most-derived in the graph that
8824 ORIG_BINFO belongs. Otherwise,
8825 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8826 BINFO that should be indicated by the RTTI information in the
8827 vtable; it will be a base class of T, rather than T itself, if we
8828 are building a construction vtable.
8830 The value returned is a TREE_LIST suitable for wrapping in a
8831 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8832 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8833 number of non-function entries in the vtable.
8835 It might seem that this function should never be called with a
8836 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8837 base is always subsumed by a derived class vtable. However, when
8838 we are building construction vtables, we do build vtables for
8839 primary bases; we need these while the primary base is being
8840 constructed. */
8842 static void
8844 tree orig_binfo,
8845 tree t,
8846 tree rtti_binfo,
8849 {
8850 tree v;
8851 vtbl_init_data vid;
8853 tree vbinfo;
8857 /* Initialize VID. */
8865 /* The first vbase or vcall offset is at index -3 in the vtable. */
8868 /* Add entries to the vtable for RTTI. */
8871 /* Create an array for keeping track of the functions we've
8872 processed. When we see multiple functions with the same
8873 signature, we share the vcall offsets. */
8875 /* Add the vcall and vbase offset entries. */
8878 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8879 build_vbase_offset_vtbl_entries. */
8884 /* If the target requires padding between data entries, add that now. */
8886 {
8891 /* Move data entries into their new positions and add padding
8892 after the new positions. Iterate backwards so we don't
8893 overwrite entries that we would need to process later. */
8896 ix--)
8897 {
8905 {
8909 null_pointer_node);
8910 }
8911 }
8912 }
8917 /* The initializers for virtual functions were built up in reverse
8918 order. Straighten them out and add them to the running list in one
8919 step. */
8928 /* Go through all the ordinary virtual functions, building up
8929 initializers. */
8931 {
8932 tree delta;
8933 tree vcall_index;
8940 {
8944 {
8947 }
8949 }
8951 /* If the only definition of this function signature along our
8952 primary base chain is from a lost primary, this vtable slot will
8953 never be used, so just zero it out. This is important to avoid
8954 requiring extra thunks which cannot be generated with the function.
8956 We first check this in update_vtable_entry_for_fn, so we handle
8957 restored primary bases properly; we also need to do it here so we
8958 zero out unused slots in ctor vtables, rather than filling them
8959 with erroneous values (though harmless, apart from relocation
8960 costs). */
8965 {
8966 /* Pull the offset for `this', and the function to call, out of
8967 the list. */
8974 /* You can't call an abstract virtual function; it's abstract.
8975 So, we replace these functions with __pure_virtual. */
8977 {
8980 {
8982 abort_fndecl_addr
8986 }
8987 }
8988 /* Likewise for deleted virtuals. */
8990 {
8999 }
9000 else
9001 {
9003 {
9007 }
9008 /* Take the address of the function, considering it to be of an
9009 appropriate generic type. */
9013 }
9014 }
9016 /* And add it to the chain of initializers. */
9018 {
9023 else
9025 {
9031 }
9032 }
9033 else
9035 }
9036 }
9038 /* Adds to vid->inits the initializers for the vbase and vcall
9039 offsets in BINFO, which is in the hierarchy dominated by T. */
9041 static void
9043 {
9044 tree b;
9046 /* If this is a derived class, we must first create entries
9047 corresponding to the primary base class. */
9052 /* Add the vbase entries for this base. */
9054 /* Add the vcall entries for this base. */
9056 }
9058 /* Returns the initializers for the vbase offset entries in the vtable
9059 for BINFO (which is part of the class hierarchy dominated by T), in
9060 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9061 where the next vbase offset will go. */
9063 static void
9065 {
9066 tree vbase;
9067 tree t;
9068 tree non_primary_binfo;
9070 /* If there are no virtual baseclasses, then there is nothing to
9071 do. */
9077 /* We might be a primary base class. Go up the inheritance hierarchy
9078 until we find the most derived class of which we are a primary base:
9079 it is the offset of that which we need to use. */
9082 {
9083 tree b;
9085 /* If we have reached a virtual base, then it must be a primary
9086 base (possibly multi-level) of vid->binfo, or we wouldn't
9087 have called build_vcall_and_vbase_vtbl_entries for it. But it
9088 might be a lost primary, so just skip down to vid->binfo. */
9090 {
9093 }
9099 }
9101 /* Go through the virtual bases, adding the offsets. */
9103 vbase;
9105 {
9106 tree b;
9107 tree delta;
9112 /* Find the instance of this virtual base in the complete
9113 object. */
9116 /* If we've already got an offset for this virtual base, we
9117 don't need another one. */
9122 /* Figure out where we can find this vbase offset. */
9131 /* The vbase offset had better be the same. */
9134 /* The next vbase will come at a more negative offset. */
9138 /* The initializer is the delta from BINFO to this virtual base.
9139 The vbase offsets go in reverse inheritance-graph order, and
9140 we are walking in inheritance graph order so these end up in
9141 the right order. */
9148 }
9149 }
9151 /* Adds the initializers for the vcall offset entries in the vtable
9152 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9153 to VID->INITS. */
9155 static void
9157 {
9158 /* We only need these entries if this base is a virtual base. We
9159 compute the indices -- but do not add to the vtable -- when
9160 building the main vtable for a class. */
9163 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9164 correspond to VID->DERIVED), we are building a primary
9165 construction virtual table. Since this is a primary
9166 virtual table, we do not need the vcall offsets for
9167 BINFO. */
9169 {
9170 /* We need a vcall offset for each of the virtual functions in this
9171 vtable. For example:
9173 class A { virtual void f (); };
9174 class B1 : virtual public A { virtual void f (); };
9175 class B2 : virtual public A { virtual void f (); };
9176 class C: public B1, public B2 { virtual void f (); };
9178 A C object has a primary base of B1, which has a primary base of A. A
9179 C also has a secondary base of B2, which no longer has a primary base
9180 of A. So the B2-in-C construction vtable needs a secondary vtable for
9181 A, which will adjust the A* to a B2* to call f. We have no way of
9182 knowing what (or even whether) this offset will be when we define B2,
9183 so we store this "vcall offset" in the A sub-vtable and look it up in
9184 a "virtual thunk" for B2::f.
9186 We need entries for all the functions in our primary vtable and
9187 in our non-virtual bases' secondary vtables. */
9189 /* If we are just computing the vcall indices -- but do not need
9190 the actual entries -- not that. */
9193 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9195 }
9196 }
9198 /* Build vcall offsets, starting with those for BINFO. */
9200 static void
9202 {
9204 tree primary_binfo;
9205 tree base_binfo;
9207 /* Don't walk into virtual bases -- except, of course, for the
9208 virtual base for which we are building vcall offsets. Any
9209 primary virtual base will have already had its offsets generated
9210 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9214 /* If BINFO has a primary base, process it first. */
9219 /* Add BINFO itself to the list. */
9222 /* Scan the non-primary bases of BINFO. */
9226 }
9228 /* Called from build_vcall_offset_vtbl_entries_r. */
9230 static void
9232 {
9233 /* Make entries for the rest of the virtuals. */
9235 {
9236 tree orig_fn;
9238 /* The ABI requires that the methods be processed in declaration
9239 order. G++ 3.2 used the order in the vtable. */
9241 orig_fn;
9245 }
9246 else
9247 {
9248 tree derived_virtuals;
9249 tree base_virtuals;
9250 tree orig_virtuals;
9251 /* If BINFO is a primary base, the most derived class which has
9252 BINFO as a primary base; otherwise, just BINFO. */
9253 tree non_primary_binfo;
9255 /* We might be a primary base class. Go up the inheritance hierarchy
9256 until we find the most derived class of which we are a primary base:
9257 it is the BINFO_VIRTUALS there that we need to consider. */
9260 {
9261 tree b;
9263 /* If we have reached a virtual base, then it must be vid->vbase,
9264 because we ignore other virtual bases in
9265 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9266 base (possibly multi-level) of vid->binfo, or we wouldn't
9267 have called build_vcall_and_vbase_vtbl_entries for it. But it
9268 might be a lost primary, so just skip down to vid->binfo. */
9270 {
9274 }
9280 }
9283 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9284 where rtti_binfo is the most derived type. */
9285 non_primary_binfo
9291 base_virtuals;
9295 {
9296 tree orig_fn;
9298 /* Find the declaration that originally caused this function to
9299 be present in BINFO_TYPE (binfo). */
9302 /* When processing BINFO, we only want to generate vcall slots for
9303 function slots introduced in BINFO. So don't try to generate
9304 one if the function isn't even defined in BINFO. */
9309 }
9310 }
9311 }
9313 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9315 static void
9317 {
9319 tree vcall_offset;
9320 tree derived_entry;
9322 /* If there is already an entry for a function with the same
9323 signature as FN, then we do not need a second vcall offset.
9324 Check the list of functions already present in the derived
9325 class vtable. */
9327 {
9329 /* We only use one vcall offset for virtual destructors,
9330 even though there are two virtual table entries. */
9334 }
9336 /* If we are building these vcall offsets as part of building
9337 the vtable for the most derived class, remember the vcall
9338 offset. */
9340 {
9343 }
9345 /* The next vcall offset will be found at a more negative
9346 offset. */
9350 /* Keep track of this function. */
9354 {
9355 tree base;
9356 tree fn;
9358 /* Find the overriding function. */
9362 else
9363 {
9366 /* The vbase we're working on is a primary base of
9367 vid->binfo. But it might be a lost primary, so its
9368 BINFO_OFFSET might be wrong, so we just use the
9369 BINFO_OFFSET from vid->binfo. */
9375 vcall_offset);
9376 }
9377 /* Add the initializer to the vtable. */
9379 }
9380 }
9382 /* Return vtbl initializers for the RTTI entries corresponding to the
9383 BINFO's vtable. The RTTI entries should indicate the object given
9384 by VID->rtti_binfo. */
9386 static void
9388 {
9389 tree b;
9390 tree t;
9391 tree offset;
9392 tree decl;
9393 tree init;
9397 /* To find the complete object, we will first convert to our most
9398 primary base, and then add the offset in the vtbl to that value. */
9402 {
9403 tree primary_base;
9409 }
9413 /* The second entry is the address of the typeinfo object. */
9416 else
9419 /* Convert the declaration to a type that can be stored in the
9420 vtable. */
9424 /* Add the offset-to-top entry. It comes earlier in the vtable than
9425 the typeinfo entry. Convert the offset to look like a
9426 function pointer, so that we can put it in the vtable. */
9429 }
9431 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9432 accessibility. */
9434 bool
9436 {
9439 }
9441 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9443 bool
9445 {
9449 }
9451 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9452 class between them, if any. */
9454 tree
9456 {
9468 {
9471 }
9475 }