| blob | 685b7b3fc18dda8b2bd2da4d34f8d1fdd72ad349 |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2015 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. */
46 /* The number of nested classes being processed. If we are not in the
47 scope of any class, this is zero. */
51 /* In order to deal with nested classes, we keep a stack of classes.
52 The topmost entry is the innermost class, and is the entry at index
53 CURRENT_CLASS_DEPTH */
56 /* The name of the class. */
57 tree name;
59 /* The _TYPE node for the class. */
60 tree type;
62 /* The access specifier pending for new declarations in the scope of
63 this class. */
64 tree access;
66 /* If were defining TYPE, the names used in this class. */
67 splay_tree names_used;
69 /* Nonzero if this class is no longer open, because of a call to
70 push_to_top_level. */
74 struct vtbl_init_data
75 {
76 /* The base for which we're building initializers. */
77 tree binfo;
78 /* The type of the most-derived type. */
79 tree derived;
80 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
81 unless ctor_vtbl_p is true. */
82 tree rtti_binfo;
83 /* The negative-index vtable initializers built up so far. These
84 are in order from least negative index to most negative index. */
86 /* The binfo for the virtual base for which we're building
87 vcall offset initializers. */
88 tree vbase;
89 /* The functions in vbase for which we have already provided vcall
90 offsets. */
92 /* The vtable index of the next vcall or vbase offset. */
93 tree index;
94 /* Nonzero if we are building the initializer for the primary
95 vtable. */
97 /* Nonzero if we are building the initializer for a construction
98 vtable. */
100 /* True when adding vcall offset entries to the vtable. False when
101 merely computing the indices. */
103 };
105 /* The type of a function passed to walk_subobject_offsets. */
108 /* The stack itself. This is a dynamically resized array. The
109 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
113 /* The size of the largest empty class seen in this translation unit. */
116 /* An array of all local classes present in this translation unit, in
117 declaration order. */
200 tree *);
210 splay_tree_key k2);
218 /* Variables shared between class.c and call.c. */
228 /* Convert to or from a base subobject. EXPR is an expression of type
229 `A' or `A*', an expression of type `B' or `B*' is returned. To
230 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
231 the B base instance within A. To convert base A to derived B, CODE
232 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
233 In this latter case, A must not be a morally virtual base of B.
234 NONNULL is true if EXPR is known to be non-NULL (this is only
235 needed when EXPR is of pointer type). CV qualifiers are preserved
236 from EXPR. */
238 tree
240 tree expr,
241 tree binfo,
243 tsubst_flags_t complain)
244 {
247 tree probe;
248 tree offset;
249 tree target_type;
251 tree ptr_target_type;
262 {
268 }
276 {
277 /* This can happen when adjust_result_of_qualified_name_lookup can't
278 find a unique base binfo in a call to a member function. We
279 couldn't give the diagnostic then since we might have been calling
280 a static member function, so we do it now. */
282 {
286 }
288 }
295 /* Nothing to do. */
299 {
301 {
303 {
306 "pointer to derived class %qT because the base is "
308 else
312 }
313 else
314 {
320 else
324 }
325 }
327 }
330 {
332 /* This must happen before the call to save_expr. */
334 }
335 else
341 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
342 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
343 expression returned matches the input. */
344 target_type = cp_build_qualified_type
348 /* Do we need to look in the vtable for the real offset? */
351 /* Don't bother with the calculations inside sizeof; they'll ICE if the
352 source type is incomplete and the pointer value doesn't matter. In a
353 template (even in instantiate_non_dependent_expr), we don't have vtables
354 set up properly yet, and the value doesn't matter there either; we're
355 just interested in the result of overload resolution. */
358 {
361 }
363 /* If we're in an NSDMI, we don't have the full constructor context yet
364 that we need for converting to a virtual base, so just build a stub
365 CONVERT_EXPR and expand it later in bot_replace. */
368 {
372 }
374 /* Do we need to check for a null pointer? */
376 {
377 /* If we know the conversion will not actually change the value
378 of EXPR, then we can avoid testing the expression for NULL.
379 We have to avoid generating a COMPONENT_REF for a base class
380 field, because other parts of the compiler know that such
381 expressions are always non-NULL. */
385 }
387 /* Protect against multiple evaluation if necessary. */
391 /* Now that we've saved expr, build the real null test. */
393 {
397 }
399 /* If this is a simple base reference, express it as a COMPONENT_REF. */
401 /* We don't build base fields for empty bases, and they aren't very
402 interesting to the optimizers anyway. */
404 {
413 }
416 {
417 /* Going via virtual base V_BINFO. We need the static offset
418 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
419 V_BINFO. That offset is an entry in D_BINFO's vtable. */
420 tree v_offset;
423 {
424 /* In a base member initializer, we cannot rely on the
425 vtable being set up. We have to indirect via the
426 vtt_parm. */
427 tree t;
433 }
434 else
435 {
438 {
443 }
445 complain),
447 }
455 v_offset);
467 /* Negative fixed_type_p means this is a constructor or destructor;
468 virtual base layout is fixed in in-charge [cd]tors, but not in
469 base [cd]tors. */
473 v_offset,
476 else
478 }
486 {
491 }
492 else
495 indout:
497 {
501 }
503 out:
509 }
511 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
512 Perform a derived-to-base conversion by recursively building up a
513 sequence of COMPONENT_REFs to the appropriate base fields. */
515 static tree
517 {
520 tree field;
523 {
524 tree temp;
528 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
529 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
530 an lvalue in the front end; only _DECLs and _REFs are lvalues
531 in the back end. */
537 }
539 /* Recurse. */
544 /* Is this the base field created by build_base_field? */
548 /* If we're looking for a field in the most-derived class,
549 also check the field offset; we can have two base fields
550 of the same type if one is an indirect virtual base and one
551 is a direct non-virtual base. */
555 {
556 /* We don't use build_class_member_access_expr here, as that
557 has unnecessary checks, and more importantly results in
558 recursive calls to dfs_walk_once. */
566 /* Mark the expression const or volatile, as appropriate.
567 Even though we've dealt with the type above, we still have
568 to mark the expression itself. */
575 }
577 /* Didn't find the base field?!? */
579 }
581 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
582 type is a class type or a pointer to a class type. In the former
583 case, TYPE is also a class type; in the latter it is another
584 pointer type. If CHECK_ACCESS is true, an error message is emitted
585 if TYPE is inaccessible. If OBJECT has pointer type, the value is
586 assumed to be non-NULL. */
588 tree
590 tsubst_flags_t complain)
591 {
592 tree binfo;
593 tree object_type;
596 {
599 }
600 else
609 }
611 /* EXPR is an expression with unqualified class type. BASE is a base
612 binfo of that class type. Returns EXPR, converted to the BASE
613 type. This function assumes that EXPR is the most derived class;
614 therefore virtual bases can be found at their static offsets. */
616 tree
618 {
619 tree expr_type;
623 {
624 /* If this is a non-empty base, use a COMPONENT_REF. */
628 /* We use fold_build2 and fold_convert below to simplify the trees
629 provided to the optimizers. It is not safe to call these functions
630 when processing a template because they do not handle C++-specific
631 trees. */
639 }
642 }
644 \f
645 tree
647 {
651 /* Can happen in case of duplicate base types (c++/59082). */
655 /* First, convert to the requested type. */
660 /* Second, the requested type may not be the owner of its own vptr.
661 If not, convert to the base class that owns it. We cannot use
662 convert_to_base here, because VCONTEXT may appear more than once
663 in the inheritance hierarchy of TYPE, and thus direct conversion
664 between the types may be ambiguous. Following the path back up
665 one step at a time via primary bases avoids the problem. */
669 {
672 }
675 }
677 /* Given an object INSTANCE, return an expression which yields the
678 vtable element corresponding to INDEX. There are many special
679 cases for INSTANCE which we take care of here, mainly to avoid
680 creating extra tree nodes when we don't have to. */
682 static tree
684 {
685 tree aref;
688 /* Try to figure out what a reference refers to, and
689 access its virtual function table directly. */
697 {
702 }
711 }
713 tree
715 {
719 }
721 /* Given a stable object pointer INSTANCE_PTR, return an expression which
722 yields a function pointer corresponding to vtable element INDEX. */
724 tree
726 {
727 tree aref;
730 tf_warning_or_error),
731 idx);
733 /* When using function descriptors, the address of the
734 vtable entry is treated as a function pointer. */
739 /* Remember this as a method reference, for later devirtualization. */
743 }
745 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
746 for the given TYPE. */
748 static tree
750 {
752 }
754 /* DECL is an entity associated with TYPE, like a virtual table or an
755 implicitly generated constructor. Determine whether or not DECL
756 should have external or internal linkage at the object file
757 level. This routine does not deal with COMDAT linkage and other
758 similar complexities; it simply sets TREE_PUBLIC if it possible for
759 entities in other translation units to contain copies of DECL, in
760 the abstract. */
762 void
764 {
767 }
769 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
770 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
771 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
773 static tree
775 {
776 tree decl;
779 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
780 now to avoid confusion in mangle_decl. */
791 /* The vtable has not been defined -- yet. */
795 /* Mark the VAR_DECL node representing the vtable itself as a
796 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
797 is rather important that such things be ignored because any
798 effort to actually generate DWARF for them will run into
799 trouble when/if we encounter code like:
801 #pragma interface
802 struct S { virtual void member (); };
804 because the artificial declaration of the vtable itself (as
805 manufactured by the g++ front end) will say that the vtable is
806 a static member of `S' but only *after* the debug output for
807 the definition of `S' has already been output. This causes
808 grief because the DWARF entry for the definition of the vtable
809 will try to refer back to an earlier *declaration* of the
810 vtable as a static member of `S' and there won't be one. We
811 might be able to arrange to have the "vtable static member"
812 attached to the member list for `S' before the debug info for
813 `S' get written (which would solve the problem) but that would
814 require more intrusive changes to the g++ front end. */
818 }
820 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
821 or even complete. If this does not exist, create it. If COMPLETE is
822 nonzero, then complete the definition of it -- that will render it
823 impossible to actually build the vtable, but is useful to get at those
824 which are known to exist in the runtime. */
826 tree
828 {
829 tree decl;
838 {
841 }
844 }
846 /* Build the primary virtual function table for TYPE. If BINFO is
847 non-NULL, build the vtable starting with the initial approximation
848 that it is the same as the one which is the head of the association
849 list. Returns a nonzero value if a new vtable is actually
850 created. */
852 static int
854 {
855 tree decl;
856 tree virtuals;
861 {
863 /* We have already created a vtable for this base, so there's
864 no need to do it again. */
871 }
872 else
873 {
876 }
879 {
882 }
884 /* Initialize the association list for this type, based
885 on our first approximation. */
890 }
892 /* Give BINFO a new virtual function table which is initialized
893 with a skeleton-copy of its original initialization. The only
894 entry that changes is the `delta' entry, so we can really
895 share a lot of structure.
897 FOR_TYPE is the most derived type which caused this table to
898 be needed.
900 Returns nonzero if we haven't met BINFO before.
902 The order in which vtables are built (by calling this function) for
903 an object must remain the same, otherwise a binary incompatibility
904 can result. */
906 static int
908 {
910 /* We already created a vtable for this base. There's no need to
911 do it again. */
914 /* Remember that we've created a vtable for this BINFO, so that we
915 don't try to do so again. */
918 /* Make fresh virtual list, so we can smash it later. */
921 /* Secondary vtables are laid out as part of the same structure as
922 the primary vtable. */
925 }
927 /* Create a new vtable for BINFO which is the hierarchy dominated by
928 T. Return nonzero if we actually created a new vtable. */
930 static int
932 {
934 /* In this case, it is *type*'s vtable we are modifying. We start
935 with the approximation that its vtable is that of the
936 immediate base class. */
938 else
939 /* This is our very own copy of `basetype' to play with. Later,
940 we will fill in all the virtual functions that override the
941 virtual functions in these base classes which are not defined
942 by the current type. */
944 }
946 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
947 (which is in the hierarchy dominated by T) list FNDECL as its
948 BV_FN. DELTA is the required constant adjustment from the `this'
949 pointer where the vtable entry appears to the `this' required when
950 the function is actually called. */
952 static void
954 tree binfo,
955 tree fndecl,
956 tree delta,
958 {
959 tree v;
965 {
966 /* We need a new vtable for BINFO. */
968 {
969 /* If we really did make a new vtable, we also made a copy
970 of the BINFO_VIRTUALS list. Now, we have to find the
971 corresponding entry in that list. */
976 }
981 }
982 }
984 \f
985 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
986 the USING_DECL naming METHOD. Returns true if the method could be
987 added to the method vec. */
989 bool
991 {
993 tree overload;
999 tree current_fns;
1000 tree fns;
1013 {
1014 /* Make a new method vector. We start with 8 entries. We must
1015 allocate at least two (for constructors and destructors), and
1016 we're going to end up with an assignment operator at some
1017 point as well. */
1019 /* Create slots for constructors and destructors. */
1023 }
1025 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1028 /* Constructors and destructors go in special slots. */
1032 {
1036 {
1042 type);
1043 }
1044 }
1045 else
1046 {
1047 tree m;
1050 /* See if we already have an entry with this name. */
1054 {
1057 {
1062 }
1066 {
1069 }
1074 }
1075 }
1078 /* Check to see if we've already got this method. */
1080 {
1082 tree fn_type;
1083 tree method_type;
1084 tree parms1;
1085 tree parms2;
1090 /* [over.load] Member function declarations with the
1091 same name and the same parameter types cannot be
1092 overloaded if any of them is a static member
1093 function declaration.
1095 [over.load] Member function declarations with the same name and
1096 the same parameter-type-list as well as member function template
1097 declarations with the same name, the same parameter-type-list, and
1098 the same template parameter lists cannot be overloaded if any of
1099 them, but not all, have a ref-qualifier.
1101 [namespace.udecl] When a using-declaration brings names
1102 from a base class into a derived class scope, member
1103 functions in the derived class override and/or hide member
1104 functions with the same name and parameter types in a base
1105 class (rather than conflicting). */
1111 /* Compare the quals on the 'this' parm. Don't compare
1112 the whole types, as used functions are treated as
1113 coming from the using class in overload resolution. */
1116 /* Either both or neither need to be ref-qualified for
1117 differing quals to allow overloading. */
1124 /* For templates, the return type and template parameters
1125 must be identical. */
1143 {
1144 /* For function versions, their parms and types match
1145 but they are not duplicates. Record function versions
1146 as and when they are found. extern "C" functions are
1147 not treated as versions. */
1153 {
1154 /* Mark functions as versions if necessary. Modify the mangled
1155 decl name if necessary. */
1157 {
1161 }
1163 {
1167 }
1170 }
1172 {
1174 {
1181 }
1182 /* Otherwise defer to the other function. */
1184 }
1186 {
1188 /* Defer to the local function. */
1190 }
1191 else
1192 {
1195 }
1197 /* We don't call duplicate_decls here to merge the
1198 declarations because that will confuse things if the
1199 methods have inline definitions. In particular, we
1200 will crash while processing the definitions. */
1202 }
1203 }
1205 /* A class should never have more than one destructor. */
1209 /* Add the new binding. */
1211 {
1214 }
1215 else
1224 {
1227 /* We only expect to add few methods in the COMPLETE_P case, so
1228 just make room for one more method in that case. */
1231 else
1237 else
1239 }
1240 else
1241 /* Replace the current slot. */
1244 }
1246 /* Subroutines of finish_struct. */
1248 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1249 legit, otherwise return 0. */
1251 static int
1253 {
1254 tree elem;
1263 {
1265 {
1269 else
1272 }
1273 else
1274 {
1275 /* They're changing the access to the same thing they changed
1276 it to before. That's OK. */
1277 ;
1278 }
1279 }
1280 else
1281 {
1283 tf_warning_or_error);
1286 }
1288 }
1290 /* Process the USING_DECL, which is a member of T. */
1292 static void
1294 {
1297 tree access
1302 tree old_value;
1307 tf_warning_or_error);
1309 {
1315 else
1317 }
1325 ;
1327 {
1329 /* It's OK to use functions from a base when there are functions with
1331 else
1332 {
1337 }
1338 }
1340 {
1344 }
1346 /* Make type T see field decl FDECL with access ACCESS. */
1349 {
1352 }
1353 else
1355 }
1356 \f
1357 /* Data structure for find_abi_tags_r, below. */
1359 struct abi_tag_data
1360 {
1364 };
1366 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1367 in the context of P. TAG can be either an identifier (the DECL_NAME of
1368 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1370 static void
1372 {
1374 {
1376 {
1377 /* We're collecting tags from template arguments or from
1378 the type of a variable or function return type. */
1381 /* Don't inherit this tag multiple times. */
1385 {
1386 /* Tags inherited from type template arguments are only used
1387 to avoid warnings. */
1390 }
1391 /* For functions and variables we want to warn, too. */
1392 }
1394 /* Otherwise we're diagnosing missing tags. */
1396 {
1401 }
1403 {
1407 }
1409 {
1414 }
1415 else
1416 {
1420 {
1424 }
1425 }
1426 }
1427 }
1429 /* Find all the ABI tags in the attribute list ATTR and either call
1430 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1432 static void
1434 {
1441 {
1446 else
1448 }
1449 }
1451 /* Find all the ABI tags on T and its enclosing scopes and either call
1452 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1454 static void
1456 {
1458 {
1459 tree attr;
1461 {
1464 }
1465 else
1466 {
1469 }
1471 }
1472 }
1474 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1475 types with ABI tags, add the corresponding identifiers to the VEC in
1476 *DATA and set IDENTIFIER_MARKED. */
1478 static tree
1480 {
1484 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1485 anyway, but let's make sure of it. */
1493 }
1495 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1496 IDENTIFIER_MARKED on its ABI tags. */
1498 static tree
1500 {
1504 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1505 anyway, but let's make sure of it. */
1513 }
1515 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1516 scopes. */
1518 static void
1520 {
1523 {
1526 {
1527 /* Template arguments are part of the signature. */
1530 {
1533 }
1534 }
1536 /* A function's parameter types are part of the signature, so
1537 we don't need to inherit any tags that are also in them. */
1542 }
1543 }
1545 /* Check that T has all the ABI tags that subobject SUBOB has, or
1546 warn if not. If T is a (variable or function) declaration, also
1547 add any missing tags. */
1549 static void
1551 {
1559 /* No need to worry about things local to this TU. */
1572 {
1576 else
1580 }
1583 }
1585 /* Check that DECL has all the ABI tags that are used in parts of its type
1586 that are not reflected in its mangled name. */
1588 void
1590 {
1596 }
1598 void
1600 {
1610 {
1613 {
1617 }
1618 }
1620 // If we found some tags on our template arguments, add them to our
1621 // abi_tag attribute.
1623 {
1627 else
1631 }
1634 }
1636 /* Return true, iff class T has a non-virtual destructor that is
1637 accessible from outside the class heirarchy (i.e. is public, or
1638 there's a suitable friend. */
1640 static bool
1642 {
1645 /* An implicitly declared destructor is always public. And,
1646 if it were virtual, we would have created it by now. */
1661 }
1663 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1664 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1665 properties of the bases. */
1667 static void
1671 {
1675 tree base_binfo;
1676 tree binfo;
1686 {
1695 /* If any base class is non-literal, so is the derived class. */
1699 /* If the base class doesn't have copy constructors or
1700 assignment operators that take const references, then the
1701 derived class cannot have such a member automatically
1702 generated. */
1711 /* A virtual base does not effect nearly emptiness. */
1712 ;
1714 {
1716 /* And if there is more than one nearly empty base, then the
1717 derived class is not nearly empty either. */
1719 else
1720 /* Remember we've seen one. */
1722 }
1724 /* If the base class is not empty or nearly empty, then this
1725 class cannot be nearly empty. */
1728 /* A lot of properties from the bases also apply to the derived
1729 class. */
1746 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1749 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1753 /* A standard-layout class is a class that:
1754 ...
1755 * has no non-standard-layout base classes, */
1758 {
1759 tree basefield;
1760 /* ...has no base classes of the same type as the first non-static
1761 data member... */
1763 && (same_type_ignoring_top_level_qualifiers_p
1766 else
1767 /* ...either has no non-static data members in the most-derived
1768 class and at most one base class with non-static data
1769 members, or has no base classes with non-static data
1770 members */
1774 {
1777 else
1780 }
1781 }
1783 /* Don't bother collecting tm attributes if transactional memory
1784 support is not enabled. */
1786 {
1790 }
1793 }
1795 /* If one of the base classes had TM attributes, and the current class
1796 doesn't define its own, then the current class inherits one. */
1798 {
1801 }
1802 }
1804 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1805 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1806 that have had a nearly-empty virtual primary base stolen by some
1807 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1808 T. */
1810 static void
1812 {
1816 tree base_binfo;
1818 /* Determine the primary bases of our bases. */
1821 {
1824 /* See if we're the non-virtual primary of our inheritance
1825 chain. */
1827 {
1834 /* We are the primary binfo. */
1836 }
1837 /* Determine if we have a virtual primary base, and mark it so.
1838 */
1840 {
1844 /* Someone already claimed this base. */
1846 else
1847 {
1848 tree delta;
1853 /* A virtual binfo might have been copied from within
1854 another hierarchy. As we're about to use it as a
1855 primary base, make sure the offsets match. */
1863 }
1864 }
1865 }
1867 /* First look for a dynamic direct non-virtual base. */
1869 {
1873 {
1876 }
1877 }
1879 /* A "nearly-empty" virtual base class can be the primary base
1880 class, if no non-virtual polymorphic base can be found. Look for
1881 a nearly-empty virtual dynamic base that is not already a primary
1882 base of something in the hierarchy. If there is no such base,
1883 just pick the first nearly-empty virtual base. */
1889 {
1891 {
1892 /* Found one that is not primary. */
1895 }
1897 /* Remember the first candidate. */
1899 }
1901 found:
1902 /* If we've got a primary base, use it. */
1904 {
1909 /* We are stealing a primary base. */
1913 {
1914 tree delta;
1917 /* A virtual binfo might have been copied from within
1918 another hierarchy. As we're about to use it as a primary
1919 base, make sure the offsets match. */
1924 }
1931 }
1932 }
1934 /* Update the variant types of T. */
1936 void
1938 {
1939 tree variants;
1945 variants;
1947 {
1948 /* These fields are in the _TYPE part of the node, not in
1949 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1959 /* Copy whatever these are holding today. */
1962 }
1963 }
1965 /* Early variant fixups: we apply attributes at the beginning of the class
1966 definition, and we need to fix up any variants that have already been
1967 made via elaborated-type-specifier so that check_qualified_type works. */
1969 void
1971 {
1972 tree variants;
1982 variants;
1984 {
1985 /* These are the two fields that check_qualified_type looks at and
1986 are affected by attributes. */
1991 else
1994 }
1995 }
1996 \f
1997 /* Set memoizing fields and bits of T (and its variants) for later
1998 use. */
2000 static void
2002 {
2003 /* Fix up variants (if any). */
2007 /* For a class w/o baseclasses, 'finish_struct' has set
2008 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2009 Similarly for a class whose base classes do not have vtables.
2010 When neither of these is true, we might have removed abstract
2011 virtuals (by providing a definition), added some (by declaring
2012 new ones), or redeclared ones from a base class. We need to
2013 recalculate what's really an abstract virtual at this point (by
2014 looking in the vtables). */
2017 /* If this type has a copy constructor or a destructor, force its
2018 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2019 nonzero. This will cause it to be passed by invisible reference
2020 and prevent it from being returned in a register. */
2023 {
2024 tree variants;
2027 {
2030 }
2031 }
2032 }
2034 /* Issue warnings about T having private constructors, but no friends,
2035 and so forth.
2037 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2038 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2039 non-private static member functions. */
2041 static void
2043 {
2046 tree fn;
2049 /* If the class has friends, those entities might create and
2050 access instances, so we should not warn. */
2053 /* We will have warned when the template was declared; there's
2054 no need to warn on every instantiation. */
2056 /* There's no reason to even consider warning about this
2057 class. */
2060 /* We only issue one warning, if more than one applies, because
2061 otherwise, on code like:
2063 class A {
2064 // Oops - forgot `public:'
2065 A();
2066 A(const A&);
2067 ~A();
2068 };
2070 we warn several times about essentially the same problem. */
2072 /* Check to see if all (non-constructor, non-destructor) member
2073 functions are private. (Since there are no friends or
2074 non-private statics, we can't ever call any of the private member
2075 functions.) */
2077 /* We're not interested in compiler-generated methods; they don't
2078 provide any way to call private members. */
2080 {
2082 {
2084 /* A non-private static member function is just like a
2085 friend; it can create and invoke private member
2086 functions, and be accessed without a class
2087 instance. */
2091 /* Keep searching for a static member function. */
2092 }
2095 }
2098 {
2099 /* There are no non-private methods, and there's at least one
2100 private member function that isn't a constructor or
2101 destructor. (If all the private members are
2102 constructors/destructors we want to use the code below that
2103 issues error messages specifically referring to
2104 constructors/destructors.) */
2110 {
2113 }
2115 {
2119 }
2120 }
2122 /* Even if some of the member functions are non-private, the class
2123 won't be useful for much if all the constructors or destructors
2124 are private: such an object can never be created or destroyed. */
2127 {
2130 t);
2132 }
2134 /* Warn about classes that have private constructors and no friends. */
2136 /* Implicitly generated constructors are always public. */
2139 {
2142 /* If a non-template class does not define a copy
2143 constructor, one is defined for it, enabling it to avoid
2144 this warning. For a template class, this does not
2145 happen, and so we would normally get a warning on:
2147 template <class T> class C { private: C(); };
2149 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2150 complete non-template or fully instantiated classes have this
2151 flag set. */
2154 else
2156 {
2158 /* Ideally, we wouldn't count copy constructors (or, in
2159 fact, any constructor that takes an argument of the
2160 class type as a parameter) because such things cannot
2161 be used to construct an instance of the class unless
2162 you already have one. But, for now at least, we're
2163 more generous. */
2165 {
2168 }
2169 }
2172 {
2175 t);
2177 }
2178 }
2179 }
2182 gt_pointer_operator new_value;
2186 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2188 static int
2190 {
2203 }
2205 /* This routine compares two fields like method_name_cmp but using the
2206 pointer operator in resort_field_decl_data. */
2208 static int
2210 {
2219 {
2226 }
2228 }
2230 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2232 void
2235 gt_pointer_operator new_value,
2237 {
2241 tree fn;
2243 /* The type conversion ops have to live at the front of the vec, so we
2244 can't sort them. */
2252 {
2256 resort_method_name_cmp);
2257 }
2258 }
2260 /* Warn about duplicate methods in fn_fields.
2262 Sort methods that are not special (i.e., constructors, destructors,
2263 and type conversion operators) so that we can find them faster in
2264 search. */
2266 static void
2268 {
2269 tree fn_fields;
2279 /* Clear DECL_IN_AGGR_P for all functions. */
2284 /* Issue warnings about private constructors and such. If there are
2285 no methods, then some public defaults are generated. */
2288 /* The type conversion ops have to live at the front of the vec, so we
2289 can't sort them. */
2298 }
2300 /* Make BINFO's vtable have N entries, including RTTI entries,
2301 vbase and vcall offsets, etc. Set its type and call the back end
2302 to lay it out. */
2304 static void
2306 {
2307 tree atype;
2308 tree vtable;
2313 /* We may have to grow the vtable. */
2316 {
2320 }
2321 }
2323 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2324 have the same signature. */
2326 int
2328 {
2329 /* One destructor overrides another if they are the same kind of
2330 destructor. */
2334 /* But a non-destructor never overrides a destructor, nor vice
2335 versa, nor do different kinds of destructors override
2336 one-another. For example, a complete object destructor does not
2337 override a deleting destructor. */
2346 {
2354 }
2356 }
2358 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2359 subobject. */
2361 static bool
2363 {
2364 tree probe;
2367 {
2371 /* If we meet a virtual base, we can't follow the inheritance
2372 any more. See if the complete type of DERIVED contains
2373 such a virtual base. */
2376 }
2378 }
2381 /* The function for which we are trying to find a final overrider. */
2382 tree fn;
2383 /* The base class in which the function was declared. */
2384 tree declaring_base;
2385 /* The candidate overriders. */
2386 tree candidates;
2387 /* Path to most derived. */
2389 };
2391 /* Add the overrider along the current path to FFOD->CANDIDATES.
2392 Returns true if an overrider was found; false otherwise. */
2394 static bool
2398 {
2399 tree method;
2401 /* If BINFO is not the most derived type, try a more derived class.
2402 A definition there will overrider a definition here. */
2404 {
2405 depth--;
2409 }
2413 {
2416 /* Remove any candidates overridden by this new function. */
2418 {
2419 /* If *CANDIDATE overrides METHOD, then METHOD
2420 cannot override anything else on the list. */
2423 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2426 else
2428 }
2430 /* Add the new function. */
2433 }
2436 }
2438 /* Called from find_final_overrider via dfs_walk. */
2440 static tree
2442 {
2450 }
2452 static tree
2454 {
2459 }
2461 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2462 FN and whose TREE_VALUE is the binfo for the base where the
2463 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2464 DERIVED) is the base object in which FN is declared. */
2466 static tree
2468 {
2469 find_final_overrider_data ffod;
2471 /* Getting this right is a little tricky. This is valid:
2473 struct S { virtual void f (); };
2474 struct T { virtual void f (); };
2475 struct U : public S, public T { };
2477 even though calling `f' in `U' is ambiguous. But,
2479 struct R { virtual void f(); };
2480 struct S : virtual public R { virtual void f (); };
2481 struct T : virtual public R { virtual void f (); };
2482 struct U : public S, public T { };
2484 is not -- there's no way to decide whether to put `S::f' or
2485 `T::f' in the vtable for `R'.
2487 The solution is to look at all paths to BINFO. If we find
2488 different overriders along any two, then there is a problem. */
2492 /* Determine the depth of the hierarchy. */
2503 /* If there was no winner, issue an error message. */
2508 }
2510 /* Return the index of the vcall offset for FN when TYPE is used as a
2511 virtual base. */
2513 static tree
2515 {
2517 tree_pair_p p;
2525 /* There should always be an appropriate index. */
2527 }
2529 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2530 dominated by T. FN is the old function; VIRTUALS points to the
2531 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2532 of that entry in the list. */
2534 static void
2537 {
2538 tree b;
2539 tree overrider;
2540 tree delta;
2541 tree virtual_base;
2542 tree first_defn;
2548 /* Find the nearest primary base (possibly binfo itself) which defines
2549 this function; this is the class the caller will convert to when
2550 calling FN through BINFO. */
2552 {
2557 /* The nearest definition is from a lost primary. */
2560 }
2563 /* Find the final overrider. */
2566 {
2569 }
2572 /* Check for adjusting covariant return types. */
2580 /* If the overrider is invalid, don't even try. */
2582 {
2583 /* If FN is a covariant thunk, we must figure out the adjustment
2584 to the final base FN was converting to. As OVERRIDER_TARGET might
2585 also be converting to the return type of FN, we have to
2586 combine the two conversions here. */
2593 {
2597 }
2598 else
2602 /* Find the equivalent binfo within the return type of the
2603 overriding function. We will want the vbase offset from
2604 there. */
2606 over_return);
2609 {
2610 /* There was no existing virtual thunk (which takes
2611 precedence). So find the binfo of the base function's
2612 return type within the overriding function's return type.
2613 We cannot call lookup base here, because we're inside a
2614 dfs_walk, and will therefore clobber the BINFO_MARKED
2615 flags. Fortunately we know the covariancy is valid (it
2616 has already been checked), so we can just iterate along
2617 the binfos, which have been chained in inheritance graph
2618 order. Of course it is lame that we have to repeat the
2619 search here anyway -- we should really be caching pieces
2620 of the vtable and avoiding this repeated work. */
2623 /* Find the base binfo within the overriding function's
2624 return type. We will always find a thunk_binfo, except
2625 when the covariancy is invalid (which we will have
2626 already diagnosed). */
2629 thunk_binfo;
2635 /* See if virtual inheritance is involved. */
2637 virtual_offset;
2644 {
2648 {
2649 /* We convert via virtual base. Adjust the fixed
2650 offset to be from there. */
2651 offset =
2655 }
2657 /* There was an existing fixed offset, this must be
2658 from the base just converted to, and the base the
2659 FN was thunking to. */
2661 else
2663 }
2664 }
2667 /* Replace the overriding function with a covariant thunk. We
2668 will emit the overriding function in its own slot as
2669 well. */
2672 }
2673 else
2677 /* If we need a covariant thunk, then we may need to adjust first_defn.
2678 The ABI specifies that the thunks emitted with a function are
2679 determined by which bases the function overrides, so we need to be
2680 sure that we're using a thunk for some overridden base; even if we
2681 know that the necessary this adjustment is zero, there may not be an
2682 appropriate zero-this-adjusment thunk for us to use since thunks for
2683 overriding virtual bases always use the vcall offset.
2685 Furthermore, just choosing any base that overrides this function isn't
2686 quite right, as this slot won't be used for calls through a type that
2687 puts a covariant thunk here. Calling the function through such a type
2688 will use a different slot, and that slot is the one that determines
2689 the thunk emitted for that base.
2691 So, keep looking until we find the base that we're really overriding
2692 in this slot: the nearest primary base that doesn't use a covariant
2693 thunk in this slot. */
2695 {
2697 /* We already know that the overrider needs a covariant thunk. */
2700 {
2707 }
2709 }
2711 /* Assume that we will produce a thunk that convert all the way to
2712 the final overrider, and not to an intermediate virtual base. */
2715 /* See if we can convert to an intermediate virtual base first, and then
2716 use the vcall offset located there to finish the conversion. */
2718 {
2719 /* If we find the final overrider, then we can stop
2720 walking. */
2725 /* If we find a virtual base, and we haven't yet found the
2726 overrider, then there is a virtual base between the
2727 declaring base (first_defn) and the final overrider. */
2729 {
2732 }
2733 }
2735 /* Compute the constant adjustment to the `this' pointer. The
2736 `this' pointer, when this function is called, will point at BINFO
2737 (or one of its primary bases, which are at the same offset). */
2739 /* The `this' pointer needs to be adjusted from the declaration to
2740 the nearest virtual base. */
2745 /* If the nearest definition is in a lost primary, we don't need an
2746 entry in our vtable. Except possibly in a constructor vtable,
2747 if we happen to get our primary back. In that case, the offset
2748 will be zero, as it will be a primary base. */
2750 else
2751 /* The `this' pointer needs to be adjusted from pointing to
2752 BINFO to pointing at the base where the final overrider
2753 appears. */
2764 else
2768 }
2770 /* Called from modify_all_vtables via dfs_walk. */
2772 static tree
2774 {
2776 tree virtuals;
2777 tree old_virtuals;
2781 /* A base without a vtable needs no modification, and its bases
2782 are uninteresting. */
2787 /* Don't do the primary vtable, if it's new. */
2791 /* There's no need to modify the vtable for a non-virtual primary
2792 base; we're not going to use that vtable anyhow. We do still
2793 need to do this for virtual primary bases, as they could become
2794 non-primary in a construction vtable. */
2799 /* Now, go through each of the virtual functions in the virtual
2800 function table for BINFO. Find the final overrider, and update
2801 the BINFO_VIRTUALS list appropriately. */
2804 virtuals;
2808 binfo,
2813 }
2815 /* Update all of the primary and secondary vtables for T. Create new
2816 vtables as required, and initialize their RTTI information. Each
2817 of the functions in VIRTUALS is declared in T and may override a
2818 virtual function from a base class; find and modify the appropriate
2819 entries to point to the overriding functions. Returns a list, in
2820 declaration order, of the virtual functions that are declared in T,
2821 but do not appear in the primary base class vtable, and which
2822 should therefore be appended to the end of the vtable for T. */
2824 static tree
2826 {
2830 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2834 /* Update all of the vtables. */
2837 /* Add virtual functions not already in our primary vtable. These
2838 will be both those introduced by this class, and those overridden
2839 from secondary bases. It does not include virtuals merely
2840 inherited from secondary bases. */
2842 {
2847 {
2848 /* We don't need to adjust the `this' pointer when
2849 calling this function. */
2853 /* This is a function not already in our vtable. Keep it. */
2855 }
2856 else
2857 /* We've already got an entry for this function. Skip it. */
2859 }
2862 }
2864 /* Get the base virtual function declarations in T that have the
2865 indicated NAME. */
2867 static void
2869 {
2870 tree methods;
2874 /* Find virtual functions in T with the indicated NAME. */
2879 methods;
2881 {
2886 {
2889 }
2890 }
2896 {
2899 }
2900 }
2902 /* If this declaration supersedes the declaration of
2903 a method declared virtual in the base class, then
2904 mark this field as being virtual as well. */
2906 void
2908 {
2911 /* In [temp.mem] we have:
2913 A specialization of a member function template does not
2914 override a virtual function from a base class. */
2921 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2922 the error_mark_node so that we know it is an overriding
2923 function. */
2924 {
2931 }
2934 {
2940 }
2945 }
2947 /* Warn about hidden virtual functions that are not overridden in t.
2948 We know that constructors and destructors don't apply. */
2950 static void
2952 {
2954 tree fns;
2957 /* We go through each separately named virtual function. */
2961 {
2962 tree fn;
2963 tree name;
2964 tree fndecl;
2965 tree base_binfo;
2966 tree binfo;
2969 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2970 have the same name. Figure out what name that is. */
2972 /* There are no possibly hidden functions yet. */
2974 /* Iterate through all of the base classes looking for possibly
2975 hidden functions. */
2978 {
2981 }
2983 /* If there are no functions to hide, continue. */
2987 /* Remove any overridden functions. */
2989 {
2993 {
2994 /* If the method from the base class has the same
2995 signature as the method from the derived class, it
2996 has been overridden. */
3001 }
3002 }
3004 /* Now give a warning for all base functions without overriders,
3005 as they are hidden. */
3007 tree base_fndecl;
3010 {
3011 /* Here we know it is a hider, and no overrider exists. */
3013 OPT_Woverloaded_virtual,
3017 }
3018 }
3019 }
3021 /* Recursive helper for finish_struct_anon. */
3023 static void
3025 {
3029 {
3030 /* We're generally only interested in entities the user
3031 declared, but we also find nested classes by noticing
3032 the TYPE_DECL that we create implicitly. You're
3033 allowed to put one anonymous union inside another,
3034 though, so we explicitly tolerate that. We use
3035 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
3036 we also allow unnamed types used for defining fields. */
3043 {
3044 /* We already complained about static data members in
3045 finish_static_data_member_decl. */
3047 {
3050 "%q#D invalid; an anonymous union can "
3052 else
3054 "%q#D invalid; an anonymous struct can "
3056 }
3058 }
3061 {
3063 {
3067 else
3070 }
3072 {
3076 else
3079 }
3080 }
3085 /* Recurse into the anonymous aggregates to handle correctly
3086 access control (c++/24926):
3088 class A {
3089 union {
3090 union {
3091 int i;
3092 };
3093 };
3094 };
3096 int j=A().i; */
3100 }
3101 }
3103 /* Check for things that are invalid. There are probably plenty of other
3104 things we should check for also. */
3106 static void
3108 {
3110 {
3119 }
3120 }
3122 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3123 will be used later during class template instantiation.
3124 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3125 a non-static member data (FIELD_DECL), a member function
3126 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3127 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3128 When FRIEND_P is nonzero, T is either a friend class
3129 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3130 (FUNCTION_DECL, TEMPLATE_DECL). */
3132 void
3134 {
3135 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3140 }
3142 /* This function is called from declare_virt_assop_and_dtor via
3143 dfs_walk_all.
3145 DATA is a type that direcly or indirectly inherits the base
3146 represented by BINFO. If BINFO contains a virtual assignment [copy
3147 assignment or move assigment] operator or a virtual constructor,
3148 declare that function in DATA if it hasn't been already declared. */
3150 static tree
3152 {
3160 /* A base without a vtable needs no modification, and its bases
3161 are uninteresting. */
3165 /* If this is a primary base, then we have already looked at the
3166 virtual functions of its vtable. */
3170 {
3174 {
3179 }
3183 }
3186 }
3188 /* If the class type T has a direct or indirect base that contains a
3189 virtual assignment operator or a virtual destructor, declare that
3190 function in T if it hasn't been already declared. */
3192 static void
3194 {
3202 dfs_declare_virt_assop_and_dtor,
3204 }
3206 /* Declare the inheriting constructor for class T inherited from base
3207 constructor CTOR with the parameter array PARMS of size NPARMS. */
3209 static void
3211 {
3212 /* We don't declare an inheriting ctor that would be a default,
3213 copy or move ctor for derived or base. */
3218 {
3222 }
3231 {
3234 }
3235 }
3237 /* Declare all the inheriting constructors for class T inherited from base
3238 constructor CTOR. */
3240 static void
3242 {
3248 {
3252 }
3255 {
3259 }
3260 }
3262 /* Create default constructors, assignment operators, and so forth for
3263 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3264 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3265 the class cannot have a default constructor, copy constructor
3266 taking a const reference argument, or an assignment operator taking
3267 a const reference, respectively. */
3269 static void
3273 {
3281 /* Destructor. */
3283 {
3284 /* In general, we create destructors lazily. */
3289 /* But if this is a Java class, any non-trivial destructor is
3290 invalid, even if compiler-generated. Therefore, if the
3291 destructor is non-trivial we create it now. */
3293 }
3295 /* [class.ctor]
3297 If there is no user-declared constructor for a class, a default
3298 constructor is implicitly declared. */
3300 {
3305 /* This might force the declaration. */
3307 }
3309 /* [class.ctor]
3311 If a class definition does not explicitly declare a copy
3312 constructor, one is declared implicitly. */
3314 {
3320 }
3322 /* If there is no assignment operator, one will be created if and
3323 when it is needed. For now, just record whether or not the type
3324 of the parameter to the assignment operator will be a const or
3325 non-const reference. */
3327 {
3333 }
3335 /* We can't be lazy about declaring functions that might override
3336 a virtual function from a base class. */
3340 {
3344 {
3345 /* declare, then remove the decl */
3354 }
3355 else
3357 }
3358 }
3360 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3361 count the number of fields in TYPE, including anonymous union
3362 members. */
3364 static int
3366 {
3367 tree x;
3370 {
3373 else
3375 }
3377 }
3379 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3380 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3381 elts, starting at offset IDX. */
3383 static int
3385 {
3386 tree x;
3388 {
3391 else
3393 }
3395 }
3397 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3398 starting at offset IDX. */
3400 static int
3404 {
3405 tree values;
3409 }
3411 /* FIELD is a bit-field. We are finishing the processing for its
3412 enclosing type. Issue any appropriate messages and set appropriate
3413 flags. Returns false if an error has been diagnosed. */
3415 static bool
3417 {
3419 tree w;
3421 /* Extract the declared width of the bitfield, which has been
3422 temporarily stashed in DECL_INITIAL. */
3425 /* Remove the bit-field width indicator so that the rest of the
3426 compiler does not treat that value as an initializer. */
3429 /* Detect invalid bit-field type. */
3431 {
3434 }
3435 else
3436 {
3438 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3441 /* detect invalid field size. */
3447 {
3450 }
3452 {
3455 }
3457 {
3460 }
3475 }
3478 {
3482 }
3483 else
3484 {
3485 /* Non-bit-fields are aligned for their type. */
3489 }
3490 }
3492 /* FIELD is a non bit-field. We are finishing the processing for its
3493 enclosing type T. Issue any appropriate messages and set appropriate
3494 flags. */
3496 static void
3498 tree t,
3502 {
3505 /* In C++98 an anonymous union cannot contain any fields which would change
3506 the settings of CANT_HAVE_CONST_CTOR and friends. */
3508 ;
3509 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3510 structs. So, we recurse through their fields here. */
3512 {
3513 tree fields;
3519 }
3520 /* Check members with class type for constructors, destructors,
3521 etc. */
3523 {
3524 /* Never let anything with uninheritable virtuals
3525 make it through without complaint. */
3529 {
3534 field);
3539 field);
3541 {
3545 }
3546 }
3547 else
3548 {
3561 }
3570 }
3575 {
3576 /* `build_class_init_list' does not recognize
3577 non-FIELD_DECLs. */
3581 }
3582 }
3584 /* Check the data members (both static and non-static), class-scoped
3585 typedefs, etc., appearing in the declaration of T. Issue
3586 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3587 declaration order) of access declarations; each TREE_VALUE in this
3588 list is a USING_DECL.
3590 In addition, set the following flags:
3592 EMPTY_P
3593 The class is empty, i.e., contains no non-static data members.
3595 CANT_HAVE_CONST_CTOR_P
3596 This class cannot have an implicitly generated copy constructor
3597 taking a const reference.
3599 CANT_HAVE_CONST_ASN_REF
3600 This class cannot have an implicitly generated assignment
3601 operator taking a const reference.
3603 All of these flags should be initialized before calling this
3604 function.
3606 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3607 fields can be added by adding to this chain. */
3609 static void
3613 {
3621 /* Assume there are no access declarations. */
3623 /* Assume this class has no pointer members. */
3625 /* Assume none of the members of this class have default
3626 initializations. */
3630 {
3638 {
3639 /* Save the access declarations for our caller. */
3642 }
3648 /* If we've gotten this far, it's a data member, possibly static,
3649 or an enumerator. */
3653 /* When this goes into scope, it will be a non-local reference. */
3658 {
3659 /* [class.union] (C++98)
3661 If a union contains a static data member, or a member of
3662 reference type, the program is ill-formed.
3664 In C++11 this limitation doesn't exist anymore. */
3666 {
3670 }
3672 {
3676 }
3677 }
3679 /* Perform error checking that did not get done in
3680 grokdeclarator. */
3682 {
3686 }
3688 {
3692 }
3700 /* Now it can only be a FIELD_DECL. */
3705 /* If at least one non-static data member is non-literal, the whole
3706 class becomes non-literal. Per Core/1453, volatile non-static
3707 data members and base classes are also not allowed.
3708 Note: if the type is incomplete we will complain later on. */
3713 /* A standard-layout class is a class that:
3714 ...
3715 has the same access control (Clause 11) for all non-static data members,
3716 ... */
3723 /* If this is of reference type, check if it needs an init. */
3725 {
3731 {
3732 /* ARM $12.6.2: [A member initializer list] (or, for an
3733 aggregate, initialization by a brace-enclosed list) is the
3734 only way to initialize nonstatic const and reference
3735 members. */
3738 }
3739 }
3744 {
3746 {
3747 warning_at
3750 x);
3752 }
3756 }
3759 /* We don't treat zero-width bitfields as making a class
3760 non-empty. */
3761 ;
3762 else
3763 {
3764 /* The class is non-empty. */
3766 /* The class is not even nearly empty. */
3768 /* If one of the data members contains an empty class,
3769 so does T. */
3773 }
3775 /* This is used by -Weffc++ (see below). Warn only for pointers
3776 to members which might hold dynamic memory. So do not warn
3777 for pointers to functions or pointers to members. */
3783 {
3788 }
3794 {
3796 {
3800 }
3802 {
3806 }
3807 }
3810 /* DR 148 now allows pointers to members (which are POD themselves),
3811 to be allowed in POD structs. */
3820 /* We set DECL_C_BIT_FIELD in grokbitfield.
3821 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3824 cant_have_const_ctor_p,
3825 no_const_asn_ref_p,
3828 /* Now that we've removed bit-field widths from DECL_INITIAL,
3829 anything left in DECL_INITIAL is an NSDMI that makes the class
3830 non-aggregate in C++11. */
3834 /* If any field is const, the structure type is pseudo-const. */
3836 {
3841 {
3842 /* ARM $12.6.2: [A member initializer list] (or, for an
3843 aggregate, initialization by a brace-enclosed list) is the
3844 only way to initialize nonstatic const and reference
3845 members. */
3848 }
3849 }
3850 /* A field that is pseudo-const makes the structure likewise. */
3852 {
3857 }
3859 /* Core issue 80: A nonstatic data member is required to have a
3860 different name from the class iff the class has a
3861 user-declared constructor. */
3866 }
3868 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3869 it should also define a copy constructor and an assignment operator to
3870 implement the correct copy semantic (deep vs shallow, etc.). As it is
3871 not feasible to check whether the constructors do allocate dynamic memory
3872 and store it within members, we approximate the warning like this:
3874 -- Warn only if there are members which are pointers
3875 -- Warn only if there is a non-trivial constructor (otherwise,
3876 there cannot be memory allocated).
3877 -- Warn only if there is a non-trivial destructor. We assume that the
3878 user at least implemented the cleanup correctly, and a destructor
3879 is needed to free dynamic memory.
3881 This seems enough for practical purposes. */
3883 && has_pointers
3887 {
3891 {
3896 }
3900 }
3902 /* Non-static data member initializers make the default constructor
3903 non-trivial. */
3905 {
3908 }
3910 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3914 /* Check anonymous struct/anonymous union fields. */
3917 /* We've built up the list of access declarations in reverse order.
3918 Fix that now. */
3920 }
3922 /* If TYPE is an empty class type, records its OFFSET in the table of
3923 OFFSETS. */
3925 static int
3927 {
3928 splay_tree_node n;
3933 /* Record the location of this empty object in OFFSETS. */
3941 type,
3945 }
3947 /* Returns nonzero if TYPE is an empty class type and there is
3948 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3950 static int
3952 {
3953 splay_tree_node n;
3954 tree t;
3959 /* Record the location of this empty object in OFFSETS. */
3969 }
3971 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3972 F for every subobject, passing it the type, offset, and table of
3973 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3974 be traversed.
3976 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3977 than MAX_OFFSET will not be walked.
3979 If F returns a nonzero value, the traversal ceases, and that value
3980 is returned. Otherwise, returns zero. */
3982 static int
3984 subobject_offset_fn f,
3985 tree offset,
3986 splay_tree offsets,
3987 tree max_offset,
3989 {
3993 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3994 stop. */
4002 {
4005 }
4008 {
4009 tree field;
4010 tree binfo;
4013 /* Avoid recursing into objects that are not interesting. */
4017 /* Record the location of TYPE. */
4022 /* Iterate through the direct base classes of TYPE. */
4026 {
4027 tree binfo_offset;
4032 tree orig_binfo;
4033 /* We cannot rely on BINFO_OFFSET being set for the base
4034 class yet, but the offsets for direct non-virtual
4035 bases can be calculated by going back to the TYPE. */
4038 offset,
4042 f,
4043 binfo_offset,
4044 offsets,
4045 max_offset,
4049 }
4052 {
4056 /* Iterate through the virtual base classes of TYPE. In G++
4057 3.2, we included virtual bases in the direct base class
4058 loop above, which results in incorrect results; the
4059 correct offsets for virtual bases are only known when
4060 working with the most derived type. */
4064 {
4066 f,
4068 offset,
4070 offsets,
4071 max_offset,
4075 }
4076 else
4077 {
4078 /* We still have to walk the primary base, if it is
4079 virtual. (If it is non-virtual, then it was walked
4080 above.) */
4086 {
4087 r = (walk_subobject_offsets
4092 }
4093 }
4094 }
4096 /* Iterate through the fields of TYPE. */
4101 {
4102 tree field_offset;
4107 f,
4109 offset,
4110 field_offset),
4111 offsets,
4112 max_offset,
4116 }
4117 }
4119 {
4122 tree index;
4124 /* Avoid recursing into objects that are not interesting. */
4129 /* Step through each of the elements in the array. */
4133 {
4135 f,
4136 offset,
4137 offsets,
4138 max_offset,
4144 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4145 there's no point in iterating through the remaining
4146 elements of the array. */
4149 }
4150 }
4153 }
4155 /* Record all of the empty subobjects of TYPE (either a type or a
4156 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4157 is being placed at OFFSET; otherwise, it is a base class that is
4158 being placed at OFFSET. */
4160 static void
4162 tree offset,
4163 splay_tree offsets,
4165 {
4166 tree max_offset;
4167 /* If recording subobjects for a non-static data member or a
4168 non-empty base class , we do not need to record offsets beyond
4169 the size of the biggest empty class. Additional data members
4170 will go at the end of the class. Additional base classes will go
4171 either at offset zero (if empty, in which case they cannot
4172 overlap with offsets past the size of the biggest empty class) or
4173 at the end of the class.
4175 However, if we are placing an empty base class, then we must record
4176 all offsets, as either the empty class is at offset zero (where
4177 other empty classes might later be placed) or at the end of the
4178 class (where other objects might then be placed, so other empty
4179 subobjects might later overlap). */
4183 else
4187 }
4189 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4190 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4191 virtual bases of TYPE are examined. */
4193 static int
4195 tree offset,
4196 splay_tree offsets,
4198 {
4199 splay_tree_node max_node;
4201 /* Get the node in OFFSETS that indicates the maximum offset where
4202 an empty subobject is located. */
4204 /* If there aren't any empty subobjects, then there's no point in
4205 performing this check. */
4211 vbases_p);
4212 }
4214 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4215 non-static data member of the type indicated by RLI. BINFO is the
4216 binfo corresponding to the base subobject, OFFSETS maps offsets to
4217 types already located at those offsets. This function determines
4218 the position of the DECL. */
4220 static void
4222 tree decl,
4223 tree binfo,
4224 splay_tree offsets)
4225 {
4228 tree type;
4231 {
4232 /* For the purposes of determining layout conflicts, we want to
4233 use the class type of BINFO; TREE_TYPE (DECL) will be the
4234 CLASSTYPE_AS_BASE version, which does not contain entries for
4235 zero-sized bases. */
4238 }
4239 else
4240 {
4243 }
4245 /* Try to place the field. It may take more than one try if we have
4246 a hard time placing the field without putting two objects of the
4247 same type at the same address. */
4249 {
4252 /* Place this field. */
4256 /* We have to check to see whether or not there is already
4257 something of the same type at the offset we're about to use.
4258 For example, consider:
4260 struct S {};
4261 struct T : public S { int i; };
4262 struct U : public S, public T {};
4264 Here, we put S at offset zero in U. Then, we can't put T at
4265 offset zero -- its S component would be at the same address
4266 as the S we already allocated. So, we have to skip ahead.
4267 Since all data members, including those whose type is an
4268 empty class, have nonzero size, any overlap can happen only
4269 with a direct or indirect base-class -- it can't happen with
4270 a data member. */
4271 /* In a union, overlap is permitted; all members are placed at
4272 offset zero. */
4277 {
4278 /* Strip off the size allocated to this field. That puts us
4279 at the first place we could have put the field with
4280 proper alignment. */
4283 /* Bump up by the alignment required for the type. */
4284 rli->bitpos
4290 }
4293 {
4294 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4295 the offset wasn't aligned like a pointer when we started to
4296 layout this field, that affects its position. */
4299 {
4302 "alignment of %qD increased in -fabi-version=9 "
4304 else
4307 }
4309 }
4310 else
4311 /* There was no conflict. We're done laying out this field. */
4313 }
4315 /* Now that we know where it will be placed, update its
4316 BINFO_OFFSET. */
4318 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4319 this point because their BINFO_OFFSET is copied from another
4320 hierarchy. Therefore, we may not need to add the entire
4321 OFFSET. */
4327 }
4329 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4331 static int
4333 tree offset,
4335 {
4337 }
4339 /* Layout the empty base BINFO. EOC indicates the byte currently just
4340 past the end of the class, and should be correctly aligned for a
4341 class of the type indicated by BINFO; OFFSETS gives the offsets of
4342 the empty bases allocated so far. T is the most derived
4343 type. Return nonzero iff we added it at the end. */
4345 static bool
4348 {
4349 tree alignment;
4353 /* This routine should only be used for empty classes. */
4358 propagate_binfo_offsets
4362 /* This is an empty base class. We first try to put it at offset
4363 zero. */
4366 offsets,
4368 {
4369 /* That didn't work. Now, we move forward from the next
4370 available spot in the class. */
4374 {
4377 offsets,
4379 /* We finally found a spot where there's no overlap. */
4382 /* There's overlap here, too. Bump along to the next spot. */
4384 }
4385 }
4388 {
4393 }
4396 }
4398 /* Layout the base given by BINFO in the class indicated by RLI.
4399 *BASE_ALIGN is a running maximum of the alignments of
4400 any base class. OFFSETS gives the location of empty base
4401 subobjects. T is the most derived type. Return nonzero if the new
4402 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4403 *NEXT_FIELD, unless BINFO is for an empty base class.
4405 Returns the location at which the next field should be inserted. */
4410 {
4415 /* This error is now reported in xref_tag, thus giving better
4416 location information. */
4419 /* Place the base class. */
4421 {
4422 tree decl;
4424 /* The containing class is non-empty because it has a non-empty
4425 base class. */
4428 /* Create the FIELD_DECL. */
4435 {
4443 /* Try to place the field. It may take more than one try if we
4444 have a hard time placing the field without putting two
4445 objects of the same type at the same address. */
4447 /* Add the new FIELD_DECL to the list of fields for T. */
4451 }
4452 }
4453 else
4454 {
4455 tree eoc;
4458 /* On some platforms (ARM), even empty classes will not be
4459 byte-aligned. */
4464 /* A nearly-empty class "has no proper base class that is empty,
4465 not morally virtual, and at an offset other than zero." */
4467 {
4470 /* The check above (used in G++ 3.2) is insufficient because
4471 an empty class placed at offset zero might itself have an
4472 empty base at a nonzero offset. */
4474 empty_base_at_nonzero_offset_p,
4475 size_zero_node,
4480 }
4482 /* We do not create a FIELD_DECL for empty base classes because
4483 it might overlap some other field. We want to be able to
4484 create CONSTRUCTORs for the class by iterating over the
4485 FIELD_DECLs, and the back end does not handle overlapping
4486 FIELD_DECLs. */
4488 /* An empty virtual base causes a class to be non-empty
4489 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4490 here because that was already done when the virtual table
4491 pointer was created. */
4492 }
4494 /* Record the offsets of BINFO and its base subobjects. */
4497 offsets,
4501 }
4503 /* Layout all of the non-virtual base classes. Record empty
4504 subobjects in OFFSETS. T is the most derived type. Return nonzero
4505 if the type cannot be nearly empty. The fields created
4506 corresponding to the base classes will be inserted at
4507 *NEXT_FIELD. */
4509 static void
4512 {
4513 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4514 subobjects. */
4519 /* The primary base class is always allocated first. */
4524 /* Now allocate the rest of the bases. */
4526 {
4527 tree base_binfo;
4531 /* The primary base was already allocated above, so we don't
4532 need to allocate it again here. */
4536 /* Virtual bases are added at the end (a primary virtual base
4537 will have already been added). */
4543 }
4544 }
4546 /* Go through the TYPE_METHODS of T issuing any appropriate
4547 diagnostics, figuring out which methods override which other
4548 methods, and so forth. */
4550 static void
4552 {
4553 tree x;
4556 {
4560 /* The name of the field is the original field name
4561 Save this in auxiliary field for later overloading. */
4563 {
4567 }
4568 /* All user-provided destructors are non-trivial.
4569 Constructors and assignment ops are handled in
4570 grok_special_member_properties. */
4576 "%<transaction_safe_dynamic%> may only be specified for "
4578 }
4579 }
4581 /* FN is a constructor or destructor. Clone the declaration to create
4582 a specialized in-charge or not-in-charge version, as indicated by
4583 NAME. */
4585 static tree
4587 {
4588 tree parms;
4589 tree clone;
4591 /* Copy the function. */
4593 /* Reset the function name. */
4595 /* Remember where this function came from. */
4597 /* Make it easy to find the CLONE given the FN. */
4601 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4603 {
4610 }
4611 else
4612 {
4613 // Clone constraints.
4617 }
4622 /* There's no pending inline data for this function. */
4626 /* The base-class destructor is not virtual. */
4628 {
4632 }
4634 /* If there was an in-charge parameter, drop it from the function
4635 type. */
4637 {
4638 tree basetype;
4639 tree parmtypes;
4640 tree exceptions;
4645 /* Skip the `this' parameter. */
4647 /* Skip the in-charge parameter. */
4649 /* And the VTT parm, in a complete [cd]tor. */
4653 /* If this is subobject constructor or destructor, add the vtt
4654 parameter. */
4658 parmtypes);
4661 exceptions);
4665 }
4667 /* Copy the function parameters. */
4669 /* Remove the in-charge parameter. */
4671 {
4675 }
4676 /* And the VTT parm, in a complete [cd]tor. */
4678 {
4681 else
4682 {
4686 }
4687 }
4690 {
4693 }
4695 /* Create the RTL for this function. */
4700 }
4702 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4703 not invoke this function directly.
4705 For a non-thunk function, returns the address of the slot for storing
4706 the function it is a clone of. Otherwise returns NULL_TREE.
4708 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4709 cloned_function is unset. This is to support the separate
4710 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4711 on a template makes sense, but not the former. */
4713 tree *
4715 {
4723 {
4724 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4727 else
4728 #endif
4730 }
4735 else
4737 }
4739 /* Produce declarations for all appropriate clones of FN. If
4740 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4741 CLASTYPE_METHOD_VEC as well. */
4743 void
4745 {
4746 tree clone;
4748 /* Avoid inappropriate cloning. */
4754 {
4755 /* For each constructor, we need two variants: an in-charge version
4756 and a not-in-charge version. */
4763 }
4764 else
4765 {
4768 /* For each destructor, we need three variants: an in-charge
4769 version, a not-in-charge version, and an in-charge deleting
4770 version. We clone the deleting version first because that
4771 means it will go second on the TYPE_METHODS list -- and that
4772 corresponds to the correct layout order in the virtual
4773 function table.
4775 For a non-virtual destructor, we do not build a deleting
4776 destructor. */
4778 {
4782 }
4789 }
4791 /* Note that this is an abstract function that is never emitted. */
4793 }
4795 /* DECL is an in charge constructor, which is being defined. This will
4796 have had an in class declaration, from whence clones were
4797 declared. An out-of-class definition can specify additional default
4798 arguments. As it is the clones that are involved in overload
4799 resolution, we must propagate the information from the DECL to its
4800 clones. */
4802 void
4804 {
4805 tree clone;
4809 {
4816 /* Skip the 'this' parameter. */
4832 {
4837 {
4838 /* A default parameter has been added. Adjust the
4839 clone's parameters. */
4843 tree type;
4848 {
4851 clone_parms);
4853 }
4856 clone_parms);
4865 }
4866 }
4868 }
4869 }
4871 /* For each of the constructors and destructors in T, create an
4872 in-charge and not-in-charge variant. */
4874 static void
4876 {
4877 tree fns;
4879 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4880 out now. */
4888 }
4890 /* Deduce noexcept for a destructor DTOR. */
4892 void
4894 {
4896 {
4899 }
4900 }
4902 /* For each destructor in T, deduce noexcept:
4904 12.4/3: A declaration of a destructor that does not have an
4905 exception-specification is implicitly considered to have the
4906 same exception-specification as an implicit declaration (15.4). */
4908 static void
4910 {
4911 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4912 out now. */
4918 }
4920 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4921 of TYPE for virtual functions which FNDECL overrides. Return a
4922 mask of the tm attributes found therein. */
4924 static int
4926 {
4928 tree base_binfo;
4932 {
4940 {
4944 else
4947 }
4948 else
4950 }
4953 }
4955 /* Subroutine of set_method_tm_attributes. Handle the checks and
4956 inheritance for one virtual method FNDECL. */
4958 static void
4960 {
4961 tree tm_attr;
4966 /* If FNDECL doesn't actually override anything (i.e. T is the
4967 class that first declares FNDECL virtual), then we're done. */
4974 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4975 tm_pure must match exactly, otherwise no weakening of
4976 tm_safe > tm_callable > nothing. */
4977 /* ??? The tm_pure attribute didn't make the transition to the
4978 multivendor language spec. */
4980 {
4982 {
4985 }
4986 }
4987 /* If the overridden function is tm_pure, then FNDECL must be. */
4990 /* Look for base class combinations that cannot be satisfied. */
4992 {
4998 }
4999 /* If FNDECL did not declare an attribute, then inherit the most
5000 restrictive one. */
5002 {
5004 }
5005 /* Otherwise validate that we're not weaker than a function
5006 that is being overridden. */
5007 else
5008 {
5012 }
5015 err_override:
5019 }
5021 /* For each of the methods in T, propagate a class-level tm attribute. */
5023 static void
5025 {
5028 /* Don't bother collecting tm attributes if transactional memory
5029 support is not enabled. */
5033 /* Process virtual methods first, as they inherit directly from the
5034 base virtual function and also require validation of new attributes. */
5036 {
5037 tree vchain;
5040 {
5045 }
5046 }
5048 /* If the class doesn't have an attribute, nothing more to do. */
5053 /* Any method that does not yet have a tm attribute inherits
5054 the one from the class. */
5056 {
5059 }
5060 }
5062 /* Returns true iff class T has a user-defined constructor other than
5063 the default constructor. */
5065 bool
5067 {
5068 tree fns;
5074 {
5081 }
5084 }
5086 /* Returns the defaulted constructor if T has one. Otherwise, returns
5087 NULL_TREE. */
5089 tree
5091 {
5098 {
5102 {
5108 }
5109 }
5112 }
5114 /* Returns true iff FN is a user-provided function, i.e. user-declared
5115 and not defaulted at its first declaration; or explicit, private,
5116 protected, or non-const. */
5118 bool
5120 {
5123 else
5127 }
5129 /* Returns true iff class T has a user-provided constructor. */
5131 bool
5133 {
5134 tree fns;
5142 /* This can happen in error cases; avoid crashing. */
5151 }
5153 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5154 declared or explicitly defaulted in the class body) default
5155 constructor. */
5157 bool
5159 {
5160 tree fns;
5168 {
5174 }
5177 }
5179 /* TYPE is being used as a virtual base, and has a non-trivial move
5180 assignment. Return true if this is due to there being a user-provided
5181 move assignment in TYPE or one of its subobjects; if there isn't, then
5182 multiple move assignment can't cause any harm. */
5184 bool
5186 {
5187 /* Does the type itself have a user-provided move assignment operator? */
5191 {
5195 }
5197 /* Do any of its bases? */
5199 tree base_binfo;
5204 /* Or non-static data members? */
5206 {
5211 }
5213 /* Seems not. */
5215 }
5217 /* If default-initialization leaves part of TYPE uninitialized, returns
5218 a DECL for the field or TYPE itself (DR 253). */
5220 tree
5222 {
5233 {
5237 }
5242 {
5246 }
5249 }
5251 /* Returns true iff for class T, a trivial synthesized default constructor
5252 would be constexpr. */
5254 bool
5256 {
5257 /* A defaulted trivial default constructor is constexpr
5258 if there is nothing to initialize. */
5261 }
5263 /* Returns true iff class T has a constexpr default constructor. */
5265 bool
5267 {
5268 tree fns;
5271 {
5272 /* The caller should have stripped an enclosing array. */
5275 }
5277 {
5280 /* Non-trivial, we need to check subobject constructors. */
5282 }
5285 }
5287 /* Returns true iff class TYPE has a virtual destructor. */
5289 bool
5291 {
5292 tree dtor;
5300 }
5302 /* Returns true iff class T has a move constructor. */
5304 bool
5306 {
5307 tree fns;
5310 {
5313 }
5323 }
5325 /* Returns true iff class T has a move assignment operator. */
5327 bool
5329 {
5330 tree fns;
5333 {
5336 }
5344 }
5346 /* Returns true iff class T has a move constructor that was explicitly
5347 declared in the class body. Note that this is different from
5348 "user-provided", which doesn't include functions that are defaulted in
5349 the class. */
5351 bool
5353 {
5354 tree fns;
5363 {
5367 }
5370 }
5372 /* Returns true iff class T has a move assignment operator that was
5373 explicitly declared in the class body. */
5375 bool
5377 {
5378 tree fns;
5385 {
5389 }
5392 }
5394 /* Nonzero if we need to build up a constructor call when initializing an
5395 object of this class, either because it has a user-declared constructor
5396 or because it doesn't have a default constructor (so we need to give an
5397 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5398 what you care about is whether or not an object can be produced by a
5399 constructor (e.g. so we don't set TREE_READONLY on const variables of
5400 such type); use this function when what you care about is whether or not
5401 to try to call a constructor to create an object. The latter case is
5402 the former plus some cases of constructors that cannot be called. */
5404 bool
5406 {
5407 tree inner;
5417 /* A user-declared constructor might be private, and a constructor might
5418 be trivial but deleted. */
5421 {
5426 }
5428 }
5430 /* Like type_build_ctor_call, but for destructors. */
5432 bool
5434 {
5435 tree inner;
5444 /* A user-declared destructor might be private, and a destructor might
5445 be trivial but deleted. */
5448 {
5453 }
5455 }
5457 /* Remove all zero-width bit-fields from T. */
5459 static void
5461 {
5466 {
5469 /* We should not be confused by the fact that grokbitfield
5470 temporarily sets the width of the bit field into
5471 DECL_INITIAL (*fieldsp).
5472 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5473 to that width. */
5477 else
5479 }
5480 }
5482 /* Returns TRUE iff we need a cookie when dynamically allocating an
5483 array whose elements have the indicated class TYPE. */
5485 static bool
5487 {
5488 tree fns;
5493 /* If there's a non-trivial destructor, we need a cookie. In order
5494 to iterate through the array calling the destructor for each
5495 element, we'll have to know how many elements there are. */
5499 /* If the usual deallocation function is a two-argument whose second
5500 argument is of type `size_t', then we have to pass the size of
5501 the array to the deallocation function, so we will need to store
5502 a cookie. */
5506 /* If there are no `operator []' members, or the lookup is
5507 ambiguous, then we don't need a cookie. */
5510 /* Loop through all of the functions. */
5512 {
5513 tree fn;
5514 tree second_parm;
5516 /* Select the current function. */
5518 /* See if this function is a one-argument delete function. If
5519 it is, then it will be the usual deallocation function. */
5523 /* Do not consider this function if its second argument is an
5524 ellipsis. */
5527 /* Otherwise, if we have a two-argument function and the second
5528 argument is `size_t', it will be the usual deallocation
5529 function -- unless there is one-argument function, too. */
5533 }
5536 }
5538 /* Finish computing the `literal type' property of class type T.
5540 At this point, we have already processed base classes and
5541 non-static data members. We need to check whether the copy
5542 constructor is trivial, the destructor is trivial, and there
5543 is a trivial default constructor or at least one constexpr
5544 constructor other than the copy constructor. */
5546 static void
5548 {
5549 tree fn;
5565 {
5568 {
5572 }
5573 }
5574 }
5576 /* T is a non-literal type used in a context which requires a constant
5577 expression. Explain why it isn't literal. */
5579 void
5581 {
5591 /* Already explained. */
5600 {
5602 "default constructor, and has no constexpr constructor that "
5605 {
5606 /* Note that we can't simply call locate_ctor because when the
5607 constructor is deleted it just returns NULL_TREE. */
5608 tree fns;
5610 {
5617 {
5620 else
5623 }
5624 }
5625 }
5626 }
5627 else
5628 {
5632 {
5635 {
5640 }
5641 }
5643 {
5644 tree ftype;
5649 {
5652 field);
5655 }
5659 }
5660 }
5661 }
5663 /* Check the validity of the bases and members declared in T. Add any
5664 implicitly-generated functions (like copy-constructors and
5665 assignment operators). Compute various flag bits (like
5666 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5667 level: i.e., independently of the ABI in use. */
5669 static void
5671 {
5672 /* Nonzero if the implicitly generated copy constructor should take
5673 a non-const reference argument. */
5675 /* Nonzero if the implicitly generated assignment operator
5676 should take a non-const reference argument. */
5678 tree access_decls;
5681 tree fn;
5683 /* By default, we use const reference arguments and generate default
5684 constructors. */
5688 /* Check all the base-classes. */
5692 /* Deduce noexcept on destructors. This needs to happen after we've set
5693 triviality flags appropriately for our bases. */
5697 /* Check all the method declarations. */
5700 /* Save the initial values of these flags which only indicate whether
5701 or not the class has user-provided functions. As we analyze the
5702 bases and members we can set these flags for other reasons. */
5706 /* Check all the data member declarations. We cannot call
5707 check_field_decls until we have called check_bases check_methods,
5708 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5709 being set appropriately. */
5714 /* A nearly-empty class has to be vptr-containing; a nearly empty
5715 class contains just a vptr. */
5719 /* Do some bookkeeping that will guide the generation of implicitly
5720 declared member functions. */
5723 /* We need to call a constructor for this class if it has a
5724 user-provided constructor, or if the default constructor is going
5725 to initialize the vptr. (This is not an if-and-only-if;
5726 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5727 themselves need constructing.) */
5730 /* [dcl.init.aggr]
5732 An aggregate is an array or a class with no user-provided
5733 constructors ... and no virtual functions.
5735 Again, other conditions for being an aggregate are checked
5736 elsewhere. */
5739 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5740 retain the old definition internally for ABI reasons. */
5749 /* If the only explicitly declared default constructor is user-provided,
5750 set TYPE_HAS_COMPLEX_DFLT. */
5756 /* Warn if a public base of a polymorphic type has an accessible
5757 non-virtual destructor. It is only now that we know the class is
5758 polymorphic. Although a polymorphic base will have a already
5759 been diagnosed during its definition, we warn on use too. */
5761 {
5764 tree base_binfo;
5768 {
5776 basetype);
5777 }
5778 }
5780 /* If the class has no user-declared constructor, but does have
5781 non-static const or reference data members that can never be
5782 initialized, issue a warning. */
5784 /* Classes with user-declared constructors are presumed to
5785 initialize these members. */
5787 /* Aggregates can be initialized with brace-enclosed
5788 initializers. */
5790 {
5791 tree field;
5794 {
5795 tree type;
5812 }
5813 }
5815 /* Synthesize any needed methods. */
5817 cant_have_const_ctor,
5818 no_const_asn_ref);
5820 /* Check defaulted declarations here so we have cant_have_const_ctor
5821 and don't need to worry about clones. */
5824 {
5827 {
5828 bool imp_const_p
5834 /* If the function is defaulted outside the class, we just
5835 give the synthesis error. */
5838 }
5840 }
5843 {
5844 /* "This class type is not an aggregate." */
5846 }
5848 /* Compute the 'literal type' property before we
5849 do anything with non-static member functions. */
5852 /* Create the in-charge and not-in-charge variants of constructors
5853 and destructors. */
5856 /* Process the using-declarations. */
5860 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5863 /* Figure out whether or not we will need a cookie when dynamically
5864 allocating an array of this type. */
5867 }
5869 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5870 accordingly. If a new vfield was created (because T doesn't have a
5871 primary base class), then the newly created field is returned. It
5872 is not added to the TYPE_FIELDS list; it is the caller's
5873 responsibility to do that. Accumulate declared virtual functions
5874 on VIRTUALS_P. */
5876 static tree
5878 {
5879 tree fn;
5881 /* Collect the virtual functions declared in T. */
5886 {
5895 }
5897 /* If we couldn't find an appropriate base class, create a new field
5898 here. Even if there weren't any new virtual functions, we might need a
5899 new virtual function table if we're supposed to include vptrs in
5900 all classes that need them. */
5902 {
5903 /* We build this decl with vtbl_ptr_type_node, which is a
5904 `vtable_entry_type*'. It might seem more precise to use
5905 `vtable_entry_type (*)[N]' where N is the number of virtual
5906 functions. However, that would require the vtable pointer in
5907 base classes to have a different type than the vtable pointer
5908 in derived classes. We could make that happen, but that
5909 still wouldn't solve all the problems. In particular, the
5910 type-based alias analysis code would decide that assignments
5911 to the base class vtable pointer can't alias assignments to
5912 the derived class vtable pointer, since they have different
5913 types. Thus, in a derived class destructor, where the base
5914 class constructor was inlined, we could generate bad code for
5915 setting up the vtable pointer.
5917 Therefore, we use one type for all vtable pointers. We still
5918 use a type-correct type; it's just doesn't indicate the array
5919 bounds. That's better than using `void*' or some such; it's
5920 cleaner, and it let's the alias analysis code know that these
5921 stores cannot alias stores to void*! */
5922 tree field;
5935 /* This class is non-empty. */
5939 }
5942 }
5944 /* Add OFFSET to all base types of BINFO which is a base in the
5945 hierarchy dominated by T.
5947 OFFSET, which is a type offset, is number of bytes. */
5949 static void
5951 {
5953 tree primary_binfo;
5954 tree base_binfo;
5956 /* Update BINFO's offset. */
5961 offset));
5963 /* Find the primary base class. */
5969 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5970 downwards. */
5972 {
5973 /* Don't do the primary base twice. */
5981 }
5982 }
5984 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5985 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5986 empty subobjects of T. */
5988 static void
5990 {
5991 tree vbase;
5998 /* Find the last field. The artificial fields created for virtual
5999 bases will go after the last extant field to date. */
6004 /* Go through the virtual bases, allocating space for each virtual
6005 base that is not already a primary base class. These are
6006 allocated in inheritance graph order. */
6008 {
6013 {
6014 /* This virtual base is not a primary base of any class in the
6015 hierarchy, so we have to add space for it. */
6018 }
6019 }
6020 }
6022 /* Returns the offset of the byte just past the end of the base class
6023 BINFO. */
6025 static tree
6027 {
6028 tree size;
6033 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6034 allocate some space for it. It cannot have virtual bases, so
6035 TYPE_SIZE_UNIT is fine. */
6037 else
6041 }
6043 /* Returns the offset of the byte just past the end of the base class
6044 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6045 only non-virtual bases are included. */
6047 static tree
6049 {
6052 tree binfo;
6053 tree base_binfo;
6054 tree offset;
6059 {
6069 }
6074 {
6078 }
6081 }
6083 /* Warn about bases of T that are inaccessible because they are
6084 ambiguous. For example:
6086 struct S {};
6087 struct T : public S {};
6088 struct U : public S, public T {};
6090 Here, `(S*) new U' is not allowed because there are two `S'
6091 subobjects of U. */
6093 static void
6095 {
6098 tree basetype;
6099 tree binfo;
6100 tree base_binfo;
6102 /* If there are no repeated bases, nothing can be ambiguous. */
6106 /* Check direct bases. */
6109 {
6115 }
6117 /* Check for ambiguous virtual bases. */
6121 {
6127 }
6128 }
6130 /* Compare two INTEGER_CSTs K1 and K2. */
6132 static int
6134 {
6136 }
6138 /* Increase the size indicated in RLI to account for empty classes
6139 that are "off the end" of the class. */
6141 static void
6143 {
6144 tree eoc;
6145 tree rli_size;
6147 /* It might be the case that we grew the class to allocate a
6148 zero-sized base class. That won't be reflected in RLI, yet,
6149 because we are willing to overlay multiple bases at the same
6150 offset. However, now we need to make sure that RLI is big enough
6151 to reflect the entire class. */
6157 {
6158 /* The size should have been rounded to a whole byte. */
6161 rli->bitpos
6170 }
6171 }
6173 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6174 BINFO_OFFSETs for all of the base-classes. Position the vtable
6175 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6177 static void
6179 {
6180 tree non_static_data_members;
6181 tree field;
6182 tree vptr;
6183 record_layout_info rli;
6184 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6185 types that appear at that offset. */
6186 splay_tree empty_base_offsets;
6187 /* True if the last field laid out was a bit-field. */
6189 /* The location at which the next field should be inserted. */
6191 /* T, as a base class. */
6192 tree base_t;
6194 /* Keep track of the first non-static data member. */
6197 /* Start laying out the record. */
6200 /* Mark all the primary bases in the hierarchy. */
6203 /* Create a pointer to our virtual function table. */
6206 /* The vptr is always the first thing in the class. */
6208 {
6213 }
6214 else
6217 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6222 /* Layout the non-static data members. */
6224 {
6225 tree type;
6226 tree padding;
6228 /* We still pass things that aren't non-static data members to
6229 the back end, in case it wants to do something with them. */
6231 {
6233 /* If the static data member has incomplete type, keep track
6234 of it so that it can be completed later. (The handling
6235 of pending statics in finish_record_layout is
6236 insufficient; consider:
6238 struct S1;
6239 struct S2 { static S1 s1; };
6241 At this point, finish_record_layout will be called, but
6242 S1 is still incomplete.) */
6244 {
6246 /* The visibility of static data members is determined
6247 at their point of declaration, not their point of
6248 definition. */
6250 }
6252 }
6260 /* If this field is a bit-field whose width is greater than its
6261 type, then there are some special rules for allocating
6262 it. */
6265 {
6267 tree integer_type;
6269 /* We must allocate the bits as if suitably aligned for the
6270 longest integer type that fits in this many bits. type
6271 of the field. Then, we are supposed to use the left over
6272 bits as additional padding. */
6281 /* ITK now indicates a type that is too large for the
6282 field. We have to back up by one to find the largest
6283 type that fits. */
6284 do
6285 {
6290 /* Figure out how much additional padding is required. */
6292 {
6294 /* In a union, the padding field must have the full width
6295 of the bit-field; all fields start at offset zero. */
6297 else
6300 }
6302 /* An unnamed bitfield does not normally affect the
6303 alignment of the containing class on a target where
6304 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6305 make any exceptions for unnamed bitfields when the
6306 bitfields are longer than their types. Therefore, we
6307 temporarily give the field a name. */
6309 {
6312 }
6318 empty_base_offsets);
6321 /* Now that layout has been performed, set the size of the
6322 field to the size of its declared type; the rest of the
6323 field is effectively invisible. */
6325 /* We must also reset the DECL_MODE of the field. */
6327 }
6328 else
6330 empty_base_offsets);
6332 /* Remember the location of any empty classes in FIELD. */
6335 empty_base_offsets,
6338 /* If a bit-field does not immediately follow another bit-field,
6339 and yet it starts in the middle of a byte, we have failed to
6340 comply with the ABI. */
6343 /* The TREE_NO_WARNING flag gets set by Objective-C when
6344 laying out an Objective-C class. The ObjC ABI differs
6345 from the C++ ABI, and so we do not want a warning
6346 here. */
6348 && !last_field_was_bitfield
6351 bitsize_unit_node)))
6353 "offset of %qD is not ABI-compliant and may "
6356 /* The middle end uses the type of expressions to determine the
6357 possible range of expression values. In order to optimize
6358 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6359 must be made aware of the width of "i", via its type.
6361 Because C++ does not have integer types of arbitrary width,
6362 we must (for the purposes of the front end) convert from the
6363 type assigned here to the declared type of the bitfield
6364 whenever a bitfield expression is used as an rvalue.
6365 Similarly, when assigning a value to a bitfield, the value
6366 must be converted to the type given the bitfield here. */
6368 {
6373 {
6380 }
6381 }
6383 /* If we needed additional padding after this field, add it
6384 now. */
6386 {
6387 tree padding_field;
6390 FIELD_DECL,
6391 NULL_TREE,
6392 char_type_node);
6399 NULL_TREE,
6400 empty_base_offsets);
6401 }
6404 }
6407 {
6408 /* Make sure that we are on a byte boundary so that the size of
6409 the class without virtual bases will always be a round number
6410 of bytes. */
6413 }
6415 /* Delete all zero-width bit-fields from the list of fields. Now
6416 that the type is laid out they are no longer important. */
6419 /* Create the version of T used for virtual bases. We do not use
6420 make_class_type for this version; this is an artificial type. For
6421 a POD type, we just reuse T. */
6423 {
6426 /* Set the size and alignment for the new type. */
6427 tree eoc;
6429 /* If the ABI version is not at least two, and the last
6430 field was a bit-field, RLI may not be on a byte
6431 boundary. In particular, rli_size_unit_so_far might
6432 indicate the last complete byte, while rli_size_so_far
6433 indicates the total number of bits used. Therefore,
6434 rli_size_so_far, rather than rli_size_unit_so_far, is
6435 used to compute TYPE_SIZE_UNIT. */
6443 eoc);
6453 /* Copy the fields from T. */
6457 {
6459 FIELD_DECL,
6469 }
6471 /* Record the base version of the type. */
6474 }
6475 else
6478 /* Every empty class contains an empty class. */
6482 /* Set the TYPE_DECL for this type to contain the right
6483 value for DECL_OFFSET, so that we can use it as part
6484 of a COMPONENT_REF for multiple inheritance. */
6487 /* Now fix up any virtual base class types that we left lying
6488 around. We must get these done before we try to lay out the
6489 virtual function table. As a side-effect, this will remove the
6490 base subobject fields. */
6493 /* Make sure that empty classes are reflected in RLI at this
6494 point. */
6497 /* Make sure not to create any structures with zero size. */
6503 /* If this is a non-POD, declaring it packed makes a difference to how it
6504 can be used as a field; don't let finalize_record_size undo it. */
6508 /* Let the back end lay out the type. */
6517 /* Warn about bases that can't be talked about due to ambiguity. */
6520 /* Now that we're done with layout, give the base fields the real types. */
6525 /* Clean up. */
6532 }
6534 /* Determine the "key method" for the class type indicated by TYPE,
6535 and set CLASSTYPE_KEY_METHOD accordingly. */
6537 void
6539 {
6540 tree method;
6543 || processing_template_decl
6548 /* The key method is the first non-pure virtual function that is not
6549 inline at the point of class definition. On some targets the
6550 key function may not be inline; those targets should not call
6551 this function until the end of the translation unit. */
6558 {
6561 }
6564 }
6567 /* Allocate and return an instance of struct sorted_fields_type with
6568 N fields. */
6572 {
6579 }
6582 /* Perform processing required when the definition of T (a class type)
6583 is complete. */
6585 void
6587 {
6588 tree x;
6589 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6593 {
6598 }
6600 /* If this type was previously laid out as a forward reference,
6601 make sure we lay it out again. */
6605 /* Make assumptions about the class; we'll reset the flags if
6606 necessary. */
6612 /* Do end-of-class semantic processing: checking the validity of the
6613 bases and members and add implicitly generated methods. */
6616 /* Find the key method. */
6618 {
6619 /* The Itanium C++ ABI permits the key method to be chosen when
6620 the class is defined -- even though the key method so
6621 selected may later turn out to be an inline function. On
6622 some systems (such as ARM Symbian OS) the key method cannot
6623 be determined until the end of the translation unit. On such
6624 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6625 will cause the class to be added to KEYED_CLASSES. Then, in
6626 finish_file we will determine the key method. */
6630 /* If a polymorphic class has no key method, we may emit the vtable
6631 in every translation unit where the class definition appears. If
6632 we're devirtualizing, we can look into the vtable even if we
6633 aren't emitting it. */
6636 }
6638 /* Layout the class itself. */
6641 /* We use the base type for trivial assignments, and hence it
6642 needs a mode. */
6647 /* If necessary, create the primary vtable for this class. */
6649 {
6650 /* We must enter these virtuals into the table. */
6654 /* Here we know enough to change the type of our virtual
6655 function table, but we will wait until later this function. */
6658 /* If we're warning about ABI tags, check the types of the new
6659 virtual functions. */
6663 }
6666 {
6668 tree fn;
6675 /* Add entries for virtual functions introduced by this class. */
6679 /* Set DECL_VINDEX for all functions declared in this class. */
6681 fn;
6683 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6685 {
6689 /* A thunk. We should never be calling this entry directly
6690 from this vtable -- we'd use the entry for the non
6691 thunk base function. */
6695 }
6696 }
6703 /* Complete the rtl for any static member objects of the type we're
6704 working on. */
6711 /* Done with FIELDS...now decide whether to sort these for
6712 faster lookups later.
6714 We use a small number because most searches fail (succeeding
6715 ultimately as the search bores through the inheritance
6716 hierarchy), and we want this failure to occur quickly. */
6720 /* Complain if one of the field types requires lower visibility. */
6723 /* Make the rtl for any new vtables we have created, and unmark
6724 the base types we marked. */
6727 /* Build the VTT for T. */
6730 /* This warning does not make sense for Java classes, since they
6731 cannot have destructors. */
6736 "%q#T has virtual functions and accessible"
6744 /* Class layout, assignment of virtual table slots, etc., is now
6745 complete. Give the back end a chance to tweak the visibility of
6746 the class or perform any other required target modifications. */
6756 /* Finish debugging output for this type. */
6760 {
6763 {
6766 }
6768 {
6771 else
6772 {
6775 }
6777 }
6779 {
6781 "the type of the first field has a different ABI from the "
6784 }
6785 }
6786 }
6788 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6789 equal to THRESHOLD or greater than THRESHOLD. */
6791 static void
6793 {
6796 {
6801 }
6802 }
6804 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6806 void
6808 {
6811 {
6813 int n_fields
6824 }
6825 }
6827 /* When T was built up, the member declarations were added in reverse
6828 order. Rearrange them to declaration order. */
6830 void
6832 {
6833 tree next;
6834 tree prev;
6835 tree x;
6837 /* The following lists are all in reverse order. Put them in
6838 declaration order now. */
6842 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6843 reverse order, so we can't just use nreverse. */
6848 {
6852 }
6854 {
6858 }
6859 }
6861 tree
6863 {
6866 /* Now that we've got all the field declarations, reverse everything
6867 as necessary. */
6873 /* Nadger the current location so that diagnostics point to the start of
6874 the struct, not the end. */
6878 {
6879 tree x;
6885 /* We need to emit an error message if this type was used as a parameter
6886 and it is an abstract type, even if it is a template. We construct
6887 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6888 account and we call complete_vars with this type, which will check
6889 the PARM_DECLS. Note that while the type is being defined,
6890 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6891 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6897 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6898 an enclosing scope is a template class, so that this function be
6899 found by lookup_fnfields_1 when the using declaration is not
6900 instantiated yet. */
6903 {
6908 }
6910 /* Remember current #pragma pack value. */
6913 /* Fix up any variants we've already built. */
6915 {
6920 }
6921 }
6922 else
6926 {
6927 /* People keep complaining that the compiler crashes on an invalid
6928 definition of initializer_list, so I guess we should explicitly
6929 reject it. What the compiler internals care about is that it's a
6930 template and has a pointer field followed by an integer field. */
6933 {
6936 {
6940 }
6941 }
6944 "definition of std::initializer_list does not match "
6946 }
6954 else
6958 /* Lambdas are defined by the LAMBDA_EXPR. */
6963 }
6964 \f
6965 /* Hash table to avoid endless recursion when handling references. */
6968 /* Return the dynamic type of INSTANCE, if known.
6969 Used to determine whether the virtual function table is needed
6970 or not.
6972 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6973 of our knowledge of its type. *NONNULL should be initialized
6974 before this function is called. */
6976 static tree
6978 {
6979 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6982 {
6986 else
6990 /* This is a call to a constructor, hence it's never zero. */
6992 {
6996 }
7000 /* This is a call to a constructor, hence it's never zero. */
7002 {
7006 }
7015 /* Propagate nonnull. */
7020 CASE_CONVERT:
7026 {
7027 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7028 with a real object -- given &p->f, p can still be null. */
7030 /* ??? Probably should check DECL_WEAK here. */
7033 }
7037 /* If this component is really a base class reference, then the field
7038 itself isn't definitive. */
7047 {
7051 }
7052 /* fall through... */
7057 {
7061 }
7063 {
7067 /* if we're in a ctor or dtor, we know our type. If
7068 current_class_ptr is set but we aren't in a function, we're in
7069 an NSDMI (and therefore a constructor). */
7074 {
7078 }
7079 }
7081 {
7082 /* We only need one hash table because it is always left empty. */
7084 fixed_type_or_null_ref_ht
7087 /* Reference variables should be references to objects. */
7091 /* Enter the INSTANCE in a table to prevent recursion; a
7092 variable's initializer may refer to the variable
7093 itself. */
7098 {
7099 tree type;
7108 }
7109 }
7114 }
7115 #undef RECUR
7116 }
7118 /* Return nonzero if the dynamic type of INSTANCE is known, and
7119 equivalent to the static type. We also handle the case where
7120 INSTANCE is really a pointer. Return negative if this is a
7121 ctor/dtor. There the dynamic type is known, but this might not be
7122 the most derived base of the original object, and hence virtual
7123 bases may not be laid out according to this type.
7125 Used to determine whether the virtual function table is needed
7126 or not.
7128 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7129 of our knowledge of its type. *NONNULL should be initialized
7130 before this function is called. */
7132 int
7134 {
7137 tree fixed;
7139 /* processing_template_decl can be false in a template if we're in
7140 instantiate_non_dependent_expr, but we still want to suppress
7141 this check. */
7143 {
7144 /* In a template we only care about the type of the result. */
7148 }
7158 }
7160 \f
7161 void
7163 {
7166 current_class_stack
7174 }
7176 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7178 static void
7180 {
7181 tree type;
7183 /* We are re-entering the same class we just left, so we don't
7184 have to search the whole inheritance matrix to find all the
7185 decls to bind again. Instead, we install the cached
7186 class_shadowed list and walk through it binding names. */
7189 /* Restore IDENTIFIER_TYPE_VALUE. */
7191 type;
7194 }
7196 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7197 appropriate for TYPE.
7199 So that we may avoid calls to lookup_name, we cache the _TYPE
7200 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7202 For multiple inheritance, we perform a two-pass depth-first search
7203 of the type lattice. */
7205 void
7207 {
7208 class_stack_node_t csn;
7212 /* Make sure there is enough room for the new entry on the stack. */
7214 {
7216 current_class_stack
7218 current_class_stack_size);
7219 }
7221 /* Insert a new entry on the class stack. */
7228 current_class_depth++;
7230 /* Now set up the new type. */
7236 /* By default, things in classes are private, while things in
7237 structures or unions are public. */
7239 ? access_private_node
7245 {
7246 /* Forcibly remove any old class remnants. */
7248 }
7254 else
7256 }
7258 /* When we exit a toplevel class scope, we save its binding level so
7259 that we can restore it quickly. Here, we've entered some other
7260 class, so we must invalidate our cache. */
7262 void
7264 {
7266 }
7268 /* Get out of the current class scope. If we were in a class scope
7269 previously, that is the one popped to. */
7271 void
7273 {
7276 current_class_depth--;
7282 }
7284 /* Mark the top of the class stack as hidden. */
7286 void
7288 {
7291 }
7293 /* Mark the top of the class stack as un-hidden. */
7295 void
7297 {
7300 }
7302 /* Returns 1 if the class type currently being defined is either T or
7303 a nested type of T. Returns the type from the current_class_stack,
7304 which might be equivalent to but not equal to T in case of
7305 constrained partial specializations. */
7307 tree
7309 {
7317 /* We start looking from 1 because entry 0 is from global scope,
7318 and has no type. */
7320 {
7321 tree c;
7324 else
7325 {
7329 }
7334 }
7336 }
7338 /* If either current_class_type or one of its enclosing classes are derived
7339 from T, return the appropriate type. Used to determine how we found
7340 something via unqualified lookup. */
7342 tree
7344 {
7347 /* The bases of a dependent type are unknown. */
7358 {
7363 }
7366 }
7368 /* Return the outermost enclosing class type that is still open, or
7369 NULL_TREE. */
7371 tree
7373 {
7380 {
7387 }
7389 }
7391 /* Returns the innermost class type which is not a lambda closure type. */
7393 tree
7395 {
7398 /* We start looking from 1 because entry 0 is from global scope,
7399 and has no type. */
7401 {
7402 tree c;
7405 else
7406 {
7410 }
7415 }
7417 }
7419 /* When entering a class scope, all enclosing class scopes' names with
7420 static meaning (static variables, static functions, types and
7421 enumerators) have to be visible. This recursive function calls
7422 pushclass for all enclosing class contexts until global or a local
7423 scope is reached. TYPE is the enclosed class. */
7425 void
7427 {
7428 /* A namespace might be passed in error cases, like A::B:C. */
7436 }
7438 /* Undoes a push_nested_class call. */
7440 void
7442 {
7448 }
7450 /* Returns the number of extern "LANG" blocks we are nested within. */
7452 int
7454 {
7456 }
7458 /* Set global variables CURRENT_LANG_NAME to appropriate value
7459 so that behavior of name-mangling machinery is correct. */
7461 void
7463 {
7467 {
7469 }
7471 {
7473 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7474 (See record_builtin_java_type in decl.c.) However, that causes
7475 incorrect debug entries if these types are actually used.
7476 So we re-enable debug output after extern "Java". */
7485 }
7487 {
7489 }
7490 else
7492 }
7494 /* Get out of the current language scope. */
7496 void
7498 {
7500 }
7501 \f
7502 /* Type instantiation routines. */
7504 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7505 matches the TARGET_TYPE. If there is no satisfactory match, return
7506 error_mark_node, and issue an error & warning messages under
7507 control of FLAGS. Permit pointers to member function if FLAGS
7508 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7509 a template-id, and EXPLICIT_TARGS are the explicitly provided
7510 template arguments.
7512 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7513 is the base path used to reference those member functions. If
7514 the address is resolved to a member function, access checks will be
7515 performed and errors issued if appropriate. */
7517 static tree
7519 tree overload,
7520 tsubst_flags_t complain,
7522 tree explicit_targs,
7523 tree access_path)
7524 {
7525 /* Here's what the standard says:
7527 [over.over]
7529 If the name is a function template, template argument deduction
7530 is done, and if the argument deduction succeeds, the deduced
7531 arguments are used to generate a single template function, which
7532 is added to the set of overloaded functions considered.
7534 Non-member functions and static member functions match targets of
7535 type "pointer-to-function" or "reference-to-function." Nonstatic
7536 member functions match targets of type "pointer-to-member
7537 function;" the function type of the pointer to member is used to
7538 select the member function from the set of overloaded member
7539 functions. If a nonstatic member function is selected, the
7540 reference to the overloaded function name is required to have the
7541 form of a pointer to member as described in 5.3.1.
7543 If more than one function is selected, any template functions in
7544 the set are eliminated if the set also contains a non-template
7545 function, and any given template function is eliminated if the
7546 set contains a second template function that is more specialized
7547 than the first according to the partial ordering rules 14.5.5.2.
7548 After such eliminations, if any, there shall remain exactly one
7549 selected function. */
7552 /* We store the matches in a TREE_LIST rooted here. The functions
7553 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7554 interoperability with most_specialized_instantiation. */
7556 tree fn;
7557 tree target_fn_type;
7559 /* By the time we get here, we should be seeing only real
7560 pointer-to-member types, not the internal POINTER_TYPE to
7561 METHOD_TYPE representation. */
7567 /* Check that the TARGET_TYPE is reasonable. */
7572 /* This is OK, too. */
7575 /* This is OK, too. This comes from a conversion to reference
7576 type. */
7578 else
7579 {
7585 }
7587 /* Non-member functions and static member functions match targets of type
7588 "pointer-to-function" or "reference-to-function." Nonstatic member
7589 functions match targets of type "pointer-to-member-function;" the
7590 function type of the pointer to member is used to select the member
7591 function from the set of overloaded member functions.
7593 So figure out the FUNCTION_TYPE that we want to match against. */
7596 /* If we can find a non-template function that matches, we can just
7597 use it. There's no point in generating template instantiations
7598 if we're just going to throw them out anyhow. But, of course, we
7599 can only do this when we don't *need* a template function. */
7601 {
7602 tree fns;
7605 {
7609 /* We're not looking for templates just yet. */
7614 /* We're looking for a non-static member, and this isn't
7615 one, or vice versa. */
7618 /* Ignore functions which haven't been explicitly
7619 declared. */
7623 /* See if there's a match. */
7628 }
7629 }
7631 /* Now, if we've already got a match (or matches), there's no need
7632 to proceed to the template functions. But, if we don't have a
7633 match we need to look at them, too. */
7635 {
7636 tree target_arg_types;
7637 tree target_ret_type;
7638 tree fns;
7641 tree arg;
7655 {
7657 tree instantiation;
7658 tree targs;
7661 /* We're only looking for templates. */
7666 /* We're not looking for a non-static member, and this is
7667 one, or vice versa. */
7672 /* If the template has a deduced return type, don't expose it to
7673 template argument deduction. */
7677 /* Try to do argument deduction. */
7684 /* Instantiation failed. */
7687 /* Constraints must be satisfied. This is done before
7688 return type deduction since that instantiates the
7689 function. */
7693 /* And now force instantiation to do return type deduction. */
7695 {
7701 }
7703 /* See if there's a match. */
7708 }
7710 /* Now, remove all but the most specialized of the matches. */
7712 {
7717 NULL_TREE,
7718 NULL_TREE);
7719 }
7720 }
7722 /* Now we should have exactly one function in MATCHES. */
7724 {
7725 /* There were *no* matches. */
7727 {
7730 target_type);
7733 }
7735 }
7737 {
7738 /* There were too many matches. First check if they're all
7739 the same function. */
7744 /* For multi-versioned functions, more than one match is just fine and
7745 decls_match will return false as they are different. */
7753 {
7755 {
7758 target_type);
7760 /* Since print_candidates expects the functions in the
7761 TREE_VALUE slot, we flip them here. */
7766 }
7769 }
7770 }
7772 /* Good, exactly one match. Now, convert it to the correct type. */
7777 {
7785 {
7788 }
7789 }
7791 /* If a pointer to a function that is multi-versioned is requested, the
7792 pointer to the dispatcher function is returned instead. This works
7793 well because indirectly calling the function will dispatch the right
7794 function version at run-time. */
7796 {
7800 /* Mark all the versions corresponding to the dispatcher as used. */
7803 }
7805 /* If we're doing overload resolution purely for the purpose of
7806 determining conversion sequences, we should not consider the
7807 function used. If this conversion sequence is selected, the
7808 function will be marked as used at this point. */
7810 {
7811 /* Make =delete work with SFINAE. */
7816 }
7818 /* We could not check access to member functions when this
7819 expression was originally created since we did not know at that
7820 time to which function the expression referred. */
7822 {
7825 }
7829 else
7830 {
7831 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7832 will mark the function as addressed, but here we must do it
7833 explicitly. */
7837 }
7838 }
7840 /* This function will instantiate the type of the expression given in
7841 RHS to match the type of LHSTYPE. If errors exist, then return
7842 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
7843 we complain on errors. If we are not complaining, never modify rhs,
7844 as overload resolution wants to try many possible instantiations, in
7845 the hope that at least one will work.
7847 For non-recursive calls, LHSTYPE should be a function, pointer to
7848 function, or a pointer to member function. */
7850 tree
7852 {
7859 {
7863 }
7866 {
7873 /* Microsoft allows `A::f' to be resolved to a
7874 pointer-to-member. */
7875 ;
7876 else
7877 {
7882 }
7883 }
7886 {
7889 }
7891 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7892 deduce any type information. */
7894 {
7898 }
7900 /* There only a few kinds of expressions that may have a type
7901 dependent on overload resolution. */
7907 /* This should really only be used when attempting to distinguish
7908 what sort of a pointer to function we have. For now, any
7909 arithmetic operation which is not supported on pointers
7910 is rejected as an error. */
7913 {
7915 {
7921 /* Do not lose object's side effects. */
7925 }
7932 /* This can happen if we are forming a pointer-to-member for a
7933 member template. */
7936 /* Fall through. */
7939 {
7943 return
7947 }
7951 return
7955 access_path);
7958 {
7963 }
7970 }
7972 }
7973 \f
7974 /* Return the name of the virtual function pointer field
7975 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7976 this may have to look back through base types to find the
7977 ultimate field name. (For single inheritance, these could
7978 all be the same name. Who knows for multiple inheritance). */
7980 static tree
7982 {
7989 {
7995 }
8003 }
8005 void
8007 {
8014 {
8019 }
8020 }
8022 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8023 according to [class]:
8024 The class-name is also inserted
8025 into the scope of the class itself. For purposes of access checking,
8026 the inserted class name is treated as if it were a public member name. */
8028 void
8030 {
8033 tree saved_cas;
8048 }
8050 /* Returns 1 if TYPE contains only padding bytes. */
8052 int
8054 {
8062 }
8064 /* Returns true if TYPE contains no actual data, just various
8065 possible combinations of empty classes and possibly a vptr. */
8067 bool
8069 {
8071 {
8072 tree field;
8073 tree binfo;
8074 tree base_binfo;
8077 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8078 out, but we'd like to be able to check this before then. */
8092 }
8096 }
8098 /* Note that NAME was looked up while the current class was being
8099 defined and that the result of that lookup was DECL. */
8101 void
8103 {
8104 splay_tree names_used;
8106 /* If we're not defining a class, there's nothing to do. */
8112 /* If there's already a binding for this NAME, then we don't have
8113 anything to worry about. */
8126 }
8128 /* Note that NAME was declared (as DECL) in the current class. Check
8129 to see that the declaration is valid. */
8131 void
8133 {
8134 splay_tree names_used;
8135 splay_tree_node n;
8137 /* Look to see if we ever used this name. */
8138 names_used
8142 /* The C language allows members to be declared with a type of the same
8143 name, and the C++ standard says this diagnostic is not required. So
8144 allow it in extern "C" blocks unless predantic is specified.
8145 Allow it in all cases if -ms-extensions is specified. */
8151 {
8152 /* [basic.scope.class]
8154 A name N used in a class S shall refer to the same declaration
8155 in its context and when re-evaluated in the completed scope of
8156 S. */
8161 }
8162 }
8164 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8165 Secondary vtables are merged with primary vtables; this function
8166 will return the VAR_DECL for the primary vtable. */
8168 tree
8170 {
8171 tree decl;
8175 {
8178 }
8182 }
8185 /* Returns the binfo for the primary base of BINFO. If the resulting
8186 BINFO is a virtual base, and it is inherited elsewhere in the
8187 hierarchy, then the returned binfo might not be the primary base of
8188 BINFO in the complete object. Check BINFO_PRIMARY_P or
8189 BINFO_LOST_PRIMARY_P to be sure. */
8191 static tree
8193 {
8194 tree primary_base;
8201 }
8203 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8205 static int
8207 {
8211 }
8213 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8214 INDENT should be zero when called from the top level; it is
8215 incremented recursively. IGO indicates the next expected BINFO in
8216 inheritance graph ordering. */
8218 static tree
8221 tree binfo,
8222 tree igo,
8224 {
8226 tree base_binfo;
8234 {
8237 }
8252 {
8256 TFF_PLAIN_IDENTIFIER),
8258 }
8260 {
8263 }
8268 {
8272 {
8276 TFF_PLAIN_IDENTIFIER));
8277 }
8279 {
8283 TFF_PLAIN_IDENTIFIER));
8284 }
8286 {
8290 TFF_PLAIN_IDENTIFIER));
8291 }
8293 {
8297 TFF_PLAIN_IDENTIFIER));
8298 }
8302 }
8308 }
8310 /* Dump the BINFO hierarchy for T. */
8312 static void
8314 {
8326 }
8328 /* Debug interface to hierarchy dumping. */
8330 void
8332 {
8334 }
8336 static void
8338 {
8343 {
8345 }
8346 }
8348 static void
8350 {
8351 tree value;
8353 HOST_WIDE_INT elt;
8361 TFF_PLAIN_IDENTIFIER));
8368 }
8370 static void
8372 {
8380 {
8387 {
8392 }
8396 }
8397 }
8399 static void
8401 {
8409 {
8414 }
8415 }
8417 /* Dump a function or thunk and its thunkees. */
8419 static void
8421 {
8424 tree thunks;
8432 {
8442 else
8448 }
8452 }
8454 /* Dump the thunks for FN. */
8456 void
8458 {
8460 }
8462 /* Virtual function table initialization. */
8464 /* Create all the necessary vtables for T and its base classes. */
8466 static void
8468 {
8469 tree vbase;
8473 /* We lay out the primary and secondary vtables in one contiguous
8474 vtable. The primary vtable is first, followed by the non-virtual
8475 secondary vtables in inheritance graph order. */
8479 /* Then come the virtual bases, also in inheritance graph order. */
8481 {
8485 }
8489 }
8491 /* Initialize the vtable for BINFO with the INITS. */
8493 static void
8495 {
8496 tree decl;
8502 }
8504 /* Build the VTT (virtual table table) for T.
8505 A class requires a VTT if it has virtual bases.
8507 This holds
8508 1 - primary virtual pointer for complete object T
8509 2 - secondary VTTs for each direct non-virtual base of T which requires a
8510 VTT
8511 3 - secondary virtual pointers for each direct or indirect base of T which
8512 has virtual bases or is reachable via a virtual path from T.
8513 4 - secondary VTTs for each direct or indirect virtual base of T.
8515 Secondary VTTs look like complete object VTTs without part 4. */
8517 static void
8519 {
8520 tree type;
8521 tree vtt;
8522 tree index;
8525 /* Build up the initializers for the VTT. */
8530 /* If we didn't need a VTT, we're done. */
8534 /* Figure out the type of the VTT. */
8538 /* Now, build the VTT object itself. */
8541 /* Add the VTT to the vtables list. */
8546 }
8548 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8549 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8550 and CHAIN the vtable pointer for this binfo after construction is
8551 complete. VALUE can also be another BINFO, in which case we recurse. */
8553 static tree
8555 {
8556 tree vt;
8559 {
8565 else
8567 }
8570 }
8572 /* Data for secondary VTT initialization. */
8573 struct secondary_vptr_vtt_init_data
8574 {
8575 /* Is this the primary VTT? */
8578 /* Current index into the VTT. */
8579 tree index;
8581 /* Vector of initializers built up. */
8584 /* The type being constructed by this secondary VTT. */
8585 tree type_being_constructed;
8586 };
8588 /* Recursively build the VTT-initializer for BINFO (which is in the
8589 hierarchy dominated by T). INITS points to the end of the initializer
8590 list to date. INDEX is the VTT index where the next element will be
8591 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8592 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8593 for virtual bases of T. When it is not so, we build the constructor
8594 vtables for the BINFO-in-T variant. */
8596 static void
8599 {
8601 tree b;
8602 tree init;
8603 secondary_vptr_vtt_init_data data;
8606 /* We only need VTTs for subobjects with virtual bases. */
8610 /* We need to use a construction vtable if this is not the primary
8611 VTT. */
8613 {
8616 /* Record the offset in the VTT where this sub-VTT can be found. */
8618 }
8620 /* Add the address of the primary vtable for the complete object. */
8624 {
8627 }
8630 /* Recursively add the secondary VTTs for non-virtual bases. */
8635 /* Add secondary virtual pointers for all subobjects of BINFO with
8636 either virtual bases or reachable along a virtual path, except
8637 subobjects that are non-virtual primary bases. */
8647 /* data.inits might have grown as we added secondary virtual pointers.
8648 Make sure our caller knows about the new vector. */
8652 /* Add the secondary VTTs for virtual bases in inheritance graph
8653 order. */
8655 {
8660 }
8661 else
8662 /* Remove the ctor vtables we created. */
8664 }
8666 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8667 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8669 static tree
8671 {
8674 /* We don't care about bases that don't have vtables. */
8678 /* We're only interested in proper subobjects of the type being
8679 constructed. */
8683 /* We're only interested in bases with virtual bases or reachable
8684 via a virtual path from the type being constructed. */
8689 /* We're not interested in non-virtual primary bases. */
8693 /* Record the index where this secondary vptr can be found. */
8695 {
8700 {
8701 /* It's a primary virtual base, and this is not a
8702 construction vtable. Find the base this is primary of in
8703 the inheritance graph, and use that base's vtable
8704 now. */
8707 }
8708 }
8710 /* Add the initializer for the secondary vptr itself. */
8713 /* Advance the vtt index. */
8718 }
8720 /* Called from build_vtt_inits via dfs_walk. After building
8721 constructor vtables and generating the sub-vtt from them, we need
8722 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8723 binfo of the base whose sub vtt was generated. */
8725 static tree
8727 {
8731 /* If this class has no vtable, none of its bases do. */
8735 /* This might be a primary base, so have no vtable in this
8736 hierarchy. */
8739 /* If we scribbled the construction vtable vptr into BINFO, clear it
8740 out now. */
8746 }
8748 /* Build the construction vtable group for BINFO which is in the
8749 hierarchy dominated by T. */
8751 static void
8753 {
8754 tree type;
8755 tree vtbl;
8756 tree id;
8757 tree vbase;
8760 /* See if we've already created this construction vtable group. */
8766 /* Build a version of VTBL (with the wrong type) for use in
8767 constructing the addresses of secondary vtables in the
8768 construction vtable group. */
8771 /* Don't export construction vtables from shared libraries. Even on
8772 targets that don't support hidden visibility, this tells
8773 can_refer_decl_in_current_unit_p not to assume that it's safe to
8774 access from a different compilation unit (bz 54314). */
8782 /* Add the vtables for each of our virtual bases using the vbase in T
8783 binfo. */
8785 vbase;
8787 {
8788 tree b;
8795 }
8797 /* Figure out the type of the construction vtable. */
8804 /* Initialize the construction vtable. */
8808 }
8810 /* Add the vtbl initializers for BINFO (and its bases other than
8811 non-virtual primaries) to the list of INITS. BINFO is in the
8812 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8813 the constructor the vtbl inits should be accumulated for. (If this
8814 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8815 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8816 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8817 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8818 but are not necessarily the same in terms of layout. */
8820 static void
8822 tree orig_binfo,
8823 tree rtti_binfo,
8824 tree vtbl,
8825 tree t,
8827 {
8829 tree base_binfo;
8834 /* If it doesn't have a vptr, we don't do anything. */
8838 /* If we're building a construction vtable, we're not interested in
8839 subobjects that don't require construction vtables. */
8845 /* Build the initializers for the BINFO-in-T vtable. */
8848 /* Walk the BINFO and its bases. We walk in preorder so that as we
8849 initialize each vtable we can figure out at what offset the
8850 secondary vtable lies from the primary vtable. We can't use
8851 dfs_walk here because we need to iterate through bases of BINFO
8852 and RTTI_BINFO simultaneously. */
8854 {
8855 /* Skip virtual bases. */
8861 inits);
8862 }
8863 }
8865 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8866 BINFO vtable to L. */
8868 static void
8870 tree orig_binfo,
8871 tree rtti_binfo,
8872 tree orig_vtbl,
8873 tree t,
8875 {
8882 {
8883 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8884 primary virtual base. If it is not the same primary in
8885 the hierarchy of T, we'll need to generate a ctor vtable
8886 for it, to place at its location in T. If it is the same
8887 primary, we still need a VTT entry for the vtable, but it
8888 should point to the ctor vtable for the base it is a
8889 primary for within the sub-hierarchy of RTTI_BINFO.
8891 There are three possible cases:
8893 1) We are in the same place.
8894 2) We are a primary base within a lost primary virtual base of
8895 RTTI_BINFO.
8896 3) We are primary to something not a base of RTTI_BINFO. */
8898 tree b;
8901 /* First, look through the bases we are primary to for RTTI_BINFO
8902 or a virtual base. */
8905 {
8910 }
8911 /* If we run out of primary links, keep looking down our
8912 inheritance chain; we might be an indirect primary. */
8916 found:
8918 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8919 base B and it is a base of RTTI_BINFO, this is case 2. In
8920 either case, we share our vtable with LAST, i.e. the
8921 derived-most base within B of which we are a primary. */
8924 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8925 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8926 binfo_ctor_vtable after everything's been set up. */
8929 /* Otherwise, this is case 3 and we get our own. */
8930 }
8937 {
8938 tree index;
8941 /* Add the initializer for this vtable. */
8945 /* Figure out the position to which the VPTR should point. */
8951 }
8954 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8955 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8956 straighten this out. */
8959 /* Throw away any unneeded intializers. */
8961 else
8962 /* For an ordinary vtable, set BINFO_VTABLE. */
8964 }
8968 /* Construct the initializer for BINFO's virtual function table. BINFO
8969 is part of the hierarchy dominated by T. If we're building a
8970 construction vtable, the ORIG_BINFO is the binfo we should use to
8971 find the actual function pointers to put in the vtable - but they
8972 can be overridden on the path to most-derived in the graph that
8973 ORIG_BINFO belongs. Otherwise,
8974 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8975 BINFO that should be indicated by the RTTI information in the
8976 vtable; it will be a base class of T, rather than T itself, if we
8977 are building a construction vtable.
8979 The value returned is a TREE_LIST suitable for wrapping in a
8980 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8981 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8982 number of non-function entries in the vtable.
8984 It might seem that this function should never be called with a
8985 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8986 base is always subsumed by a derived class vtable. However, when
8987 we are building construction vtables, we do build vtables for
8988 primary bases; we need these while the primary base is being
8989 constructed. */
8991 static void
8993 tree orig_binfo,
8994 tree t,
8995 tree rtti_binfo,
8998 {
8999 tree v;
9000 vtbl_init_data vid;
9002 tree vbinfo;
9006 /* Initialize VID. */
9014 /* The first vbase or vcall offset is at index -3 in the vtable. */
9017 /* Add entries to the vtable for RTTI. */
9020 /* Create an array for keeping track of the functions we've
9021 processed. When we see multiple functions with the same
9022 signature, we share the vcall offsets. */
9024 /* Add the vcall and vbase offset entries. */
9027 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9028 build_vbase_offset_vtbl_entries. */
9033 /* If the target requires padding between data entries, add that now. */
9035 {
9040 /* Move data entries into their new positions and add padding
9041 after the new positions. Iterate backwards so we don't
9042 overwrite entries that we would need to process later. */
9045 ix--)
9046 {
9054 {
9058 null_pointer_node);
9059 }
9060 }
9061 }
9066 /* The initializers for virtual functions were built up in reverse
9067 order. Straighten them out and add them to the running list in one
9068 step. */
9077 /* Go through all the ordinary virtual functions, building up
9078 initializers. */
9080 {
9081 tree delta;
9082 tree vcall_index;
9089 {
9093 {
9096 }
9098 }
9100 /* If the only definition of this function signature along our
9101 primary base chain is from a lost primary, this vtable slot will
9102 never be used, so just zero it out. This is important to avoid
9103 requiring extra thunks which cannot be generated with the function.
9105 We first check this in update_vtable_entry_for_fn, so we handle
9106 restored primary bases properly; we also need to do it here so we
9107 zero out unused slots in ctor vtables, rather than filling them
9108 with erroneous values (though harmless, apart from relocation
9109 costs). */
9114 {
9115 /* Pull the offset for `this', and the function to call, out of
9116 the list. */
9123 /* You can't call an abstract virtual function; it's abstract.
9124 So, we replace these functions with __pure_virtual. */
9126 {
9129 {
9131 abort_fndecl_addr
9135 }
9136 }
9137 /* Likewise for deleted virtuals. */
9139 {
9148 }
9149 else
9150 {
9152 {
9156 }
9157 /* Take the address of the function, considering it to be of an
9158 appropriate generic type. */
9162 /* Don't refer to a virtual destructor from a constructor
9163 vtable or a vtable for an abstract class, since destroying
9164 an object under construction is undefined behavior and we
9165 don't want it to be considered a candidate for speculative
9166 devirtualization. But do create the thunk for ABI
9167 compliance. */
9172 }
9173 }
9175 /* And add it to the chain of initializers. */
9177 {
9182 else
9184 {
9190 }
9191 }
9192 else
9194 }
9195 }
9197 /* Adds to vid->inits the initializers for the vbase and vcall
9198 offsets in BINFO, which is in the hierarchy dominated by T. */
9200 static void
9202 {
9203 tree b;
9205 /* If this is a derived class, we must first create entries
9206 corresponding to the primary base class. */
9211 /* Add the vbase entries for this base. */
9213 /* Add the vcall entries for this base. */
9215 }
9217 /* Returns the initializers for the vbase offset entries in the vtable
9218 for BINFO (which is part of the class hierarchy dominated by T), in
9219 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9220 where the next vbase offset will go. */
9222 static void
9224 {
9225 tree vbase;
9226 tree t;
9227 tree non_primary_binfo;
9229 /* If there are no virtual baseclasses, then there is nothing to
9230 do. */
9236 /* We might be a primary base class. Go up the inheritance hierarchy
9237 until we find the most derived class of which we are a primary base:
9238 it is the offset of that which we need to use. */
9241 {
9242 tree b;
9244 /* If we have reached a virtual base, then it must be a primary
9245 base (possibly multi-level) of vid->binfo, or we wouldn't
9246 have called build_vcall_and_vbase_vtbl_entries for it. But it
9247 might be a lost primary, so just skip down to vid->binfo. */
9249 {
9252 }
9258 }
9260 /* Go through the virtual bases, adding the offsets. */
9262 vbase;
9264 {
9265 tree b;
9266 tree delta;
9271 /* Find the instance of this virtual base in the complete
9272 object. */
9275 /* If we've already got an offset for this virtual base, we
9276 don't need another one. */
9281 /* Figure out where we can find this vbase offset. */
9290 /* The vbase offset had better be the same. */
9293 /* The next vbase will come at a more negative offset. */
9297 /* The initializer is the delta from BINFO to this virtual base.
9298 The vbase offsets go in reverse inheritance-graph order, and
9299 we are walking in inheritance graph order so these end up in
9300 the right order. */
9307 }
9308 }
9310 /* Adds the initializers for the vcall offset entries in the vtable
9311 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9312 to VID->INITS. */
9314 static void
9316 {
9317 /* We only need these entries if this base is a virtual base. We
9318 compute the indices -- but do not add to the vtable -- when
9319 building the main vtable for a class. */
9322 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9323 correspond to VID->DERIVED), we are building a primary
9324 construction virtual table. Since this is a primary
9325 virtual table, we do not need the vcall offsets for
9326 BINFO. */
9328 {
9329 /* We need a vcall offset for each of the virtual functions in this
9330 vtable. For example:
9332 class A { virtual void f (); };
9333 class B1 : virtual public A { virtual void f (); };
9334 class B2 : virtual public A { virtual void f (); };
9335 class C: public B1, public B2 { virtual void f (); };
9337 A C object has a primary base of B1, which has a primary base of A. A
9338 C also has a secondary base of B2, which no longer has a primary base
9339 of A. So the B2-in-C construction vtable needs a secondary vtable for
9340 A, which will adjust the A* to a B2* to call f. We have no way of
9341 knowing what (or even whether) this offset will be when we define B2,
9342 so we store this "vcall offset" in the A sub-vtable and look it up in
9343 a "virtual thunk" for B2::f.
9345 We need entries for all the functions in our primary vtable and
9346 in our non-virtual bases' secondary vtables. */
9348 /* If we are just computing the vcall indices -- but do not need
9349 the actual entries -- not that. */
9352 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9354 }
9355 }
9357 /* Build vcall offsets, starting with those for BINFO. */
9359 static void
9361 {
9363 tree primary_binfo;
9364 tree base_binfo;
9366 /* Don't walk into virtual bases -- except, of course, for the
9367 virtual base for which we are building vcall offsets. Any
9368 primary virtual base will have already had its offsets generated
9369 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9373 /* If BINFO has a primary base, process it first. */
9378 /* Add BINFO itself to the list. */
9381 /* Scan the non-primary bases of BINFO. */
9385 }
9387 /* Called from build_vcall_offset_vtbl_entries_r. */
9389 static void
9391 {
9392 /* Make entries for the rest of the virtuals. */
9393 tree orig_fn;
9395 /* The ABI requires that the methods be processed in declaration
9396 order. */
9398 orig_fn;
9402 }
9404 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9406 static void
9408 {
9410 tree vcall_offset;
9411 tree derived_entry;
9413 /* If there is already an entry for a function with the same
9414 signature as FN, then we do not need a second vcall offset.
9415 Check the list of functions already present in the derived
9416 class vtable. */
9418 {
9420 /* We only use one vcall offset for virtual destructors,
9421 even though there are two virtual table entries. */
9425 }
9427 /* If we are building these vcall offsets as part of building
9428 the vtable for the most derived class, remember the vcall
9429 offset. */
9431 {
9434 }
9436 /* The next vcall offset will be found at a more negative
9437 offset. */
9441 /* Keep track of this function. */
9445 {
9446 tree base;
9447 tree fn;
9449 /* Find the overriding function. */
9453 else
9454 {
9457 /* The vbase we're working on is a primary base of
9458 vid->binfo. But it might be a lost primary, so its
9459 BINFO_OFFSET might be wrong, so we just use the
9460 BINFO_OFFSET from vid->binfo. */
9466 vcall_offset);
9467 }
9468 /* Add the initializer to the vtable. */
9470 }
9471 }
9473 /* Return vtbl initializers for the RTTI entries corresponding to the
9474 BINFO's vtable. The RTTI entries should indicate the object given
9475 by VID->rtti_binfo. */
9477 static void
9479 {
9480 tree b;
9481 tree t;
9482 tree offset;
9483 tree decl;
9484 tree init;
9488 /* To find the complete object, we will first convert to our most
9489 primary base, and then add the offset in the vtbl to that value. */
9493 {
9494 tree primary_base;
9500 }
9504 /* The second entry is the address of the typeinfo object. */
9507 else
9510 /* Convert the declaration to a type that can be stored in the
9511 vtable. */
9515 /* Add the offset-to-top entry. It comes earlier in the vtable than
9516 the typeinfo entry. Convert the offset to look like a
9517 function pointer, so that we can put it in the vtable. */
9520 }
9522 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9523 accessibility. */
9525 bool
9527 {
9530 }
9532 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9534 bool
9536 {
9540 }
9542 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9543 class between them, if any. */
9545 tree
9547 {
9559 {
9562 }
9566 }