| blob | 039dbd0df3e9f5b3a078ee43aa81ae39f6a39cee |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2013 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* High-level class interface. */
44 /* The number of nested classes being processed. If we are not in the
45 scope of any class, this is zero. */
49 /* In order to deal with nested classes, we keep a stack of classes.
50 The topmost entry is the innermost class, and is the entry at index
51 CURRENT_CLASS_DEPTH */
54 /* The name of the class. */
55 tree name;
57 /* The _TYPE node for the class. */
58 tree type;
60 /* The access specifier pending for new declarations in the scope of
61 this class. */
62 tree access;
64 /* If were defining TYPE, the names used in this class. */
65 splay_tree names_used;
67 /* Nonzero if this class is no longer open, because of a call to
68 push_to_top_level. */
73 {
74 /* The base for which we're building initializers. */
75 tree binfo;
76 /* The type of the most-derived type. */
77 tree derived;
78 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
79 unless ctor_vtbl_p is true. */
80 tree rtti_binfo;
81 /* The negative-index vtable initializers built up so far. These
82 are in order from least negative index to most negative index. */
84 /* The binfo for the virtual base for which we're building
85 vcall offset initializers. */
86 tree vbase;
87 /* The functions in vbase for which we have already provided vcall
88 offsets. */
90 /* The vtable index of the next vcall or vbase offset. */
91 tree index;
92 /* Nonzero if we are building the initializer for the primary
93 vtable. */
95 /* Nonzero if we are building the initializer for a construction
96 vtable. */
98 /* True when adding vcall offset entries to the vtable. False when
99 merely computing the indices. */
103 /* The type of a function passed to walk_subobject_offsets. */
106 /* The stack itself. This is a dynamically resized array. The
107 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
111 /* The size of the largest empty class seen in this translation unit. */
114 /* An array of all local classes present in this translation unit, in
115 declaration order. */
197 tree *);
207 splay_tree_key k2);
216 /* Variables shared between class.c and call.c. */
226 /* Convert to or from a base subobject. EXPR is an expression of type
227 `A' or `A*', an expression of type `B' or `B*' is returned. To
228 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
229 the B base instance within A. To convert base A to derived B, CODE
230 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
231 In this latter case, A must not be a morally virtual base of B.
232 NONNULL is true if EXPR is known to be non-NULL (this is only
233 needed when EXPR is of pointer type). CV qualifiers are preserved
234 from EXPR. */
236 tree
238 tree expr,
239 tree binfo,
241 tsubst_flags_t complain)
242 {
245 tree probe;
246 tree offset;
247 tree target_type;
249 tree ptr_target_type;
259 {
265 }
273 {
274 /* This can happen when adjust_result_of_qualified_name_lookup can't
275 find a unique base binfo in a call to a member function. We
276 couldn't give the diagnostic then since we might have been calling
277 a static member function, so we do it now. */
279 {
283 }
285 }
292 /* Nothing to do. */
296 {
298 {
300 {
303 "pointer to derived class %qT because the base is "
305 else
309 }
310 else
311 {
317 else
321 }
322 }
324 }
327 /* This must happen before the call to save_expr. */
329 else
335 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
336 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
337 expression returned matches the input. */
338 target_type = cp_build_qualified_type
342 /* Do we need to look in the vtable for the real offset? */
345 /* Don't bother with the calculations inside sizeof; they'll ICE if the
346 source type is incomplete and the pointer value doesn't matter. In a
347 template (even in fold_non_dependent_expr), we don't have vtables set
348 up properly yet, and the value doesn't matter there either; we're just
349 interested in the result of overload resolution. */
352 {
357 }
359 /* If we're in an NSDMI, we don't have the full constructor context yet
360 that we need for converting to a virtual base, so just build a stub
361 CONVERT_EXPR and expand it later in bot_replace. */
364 {
370 }
372 /* Do we need to check for a null pointer? */
374 {
375 /* If we know the conversion will not actually change the value
376 of EXPR, then we can avoid testing the expression for NULL.
377 We have to avoid generating a COMPONENT_REF for a base class
378 field, because other parts of the compiler know that such
379 expressions are always non-NULL. */
383 }
385 /* Protect against multiple evaluation if necessary. */
389 /* Now that we've saved expr, build the real null test. */
391 {
395 }
397 /* If this is a simple base reference, express it as a COMPONENT_REF. */
399 /* We don't build base fields for empty bases, and they aren't very
400 interesting to the optimizers anyway. */
402 {
409 }
412 {
413 /* Going via virtual base V_BINFO. We need the static offset
414 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
415 V_BINFO. That offset is an entry in D_BINFO's vtable. */
416 tree v_offset;
419 {
420 /* In a base member initializer, we cannot rely on the
421 vtable being set up. We have to indirect via the
422 vtt_parm. */
423 tree t;
429 }
430 else
432 complain),
438 v_offset);
450 /* Negative fixed_type_p means this is a constructor or destructor;
451 virtual base layout is fixed in in-charge [cd]tors, but not in
452 base [cd]tors. */
456 v_offset,
459 else
461 }
469 {
474 }
475 else
481 out:
487 }
489 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
490 Perform a derived-to-base conversion by recursively building up a
491 sequence of COMPONENT_REFs to the appropriate base fields. */
493 static tree
495 {
498 tree field;
501 {
502 tree temp;
506 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
507 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
508 an lvalue in the front end; only _DECLs and _REFs are lvalues
509 in the back end. */
515 }
517 /* Recurse. */
522 /* Is this the base field created by build_base_field? */
526 /* If we're looking for a field in the most-derived class,
527 also check the field offset; we can have two base fields
528 of the same type if one is an indirect virtual base and one
529 is a direct non-virtual base. */
533 {
534 /* We don't use build_class_member_access_expr here, as that
535 has unnecessary checks, and more importantly results in
536 recursive calls to dfs_walk_once. */
544 /* Mark the expression const or volatile, as appropriate.
545 Even though we've dealt with the type above, we still have
546 to mark the expression itself. */
553 }
555 /* Didn't find the base field?!? */
557 }
559 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
560 type is a class type or a pointer to a class type. In the former
561 case, TYPE is also a class type; in the latter it is another
562 pointer type. If CHECK_ACCESS is true, an error message is emitted
563 if TYPE is inaccessible. If OBJECT has pointer type, the value is
564 assumed to be non-NULL. */
566 tree
568 tsubst_flags_t complain)
569 {
570 tree binfo;
571 tree object_type;
574 {
577 }
578 else
587 }
589 /* EXPR is an expression with unqualified class type. BASE is a base
590 binfo of that class type. Returns EXPR, converted to the BASE
591 type. This function assumes that EXPR is the most derived class;
592 therefore virtual bases can be found at their static offsets. */
594 tree
596 {
597 tree expr_type;
601 {
602 /* If this is a non-empty base, use a COMPONENT_REF. */
606 /* We use fold_build2 and fold_convert below to simplify the trees
607 provided to the optimizers. It is not safe to call these functions
608 when processing a template because they do not handle C++-specific
609 trees. */
617 }
620 }
622 \f
623 tree
625 {
631 /* First, convert to the requested type. */
636 /* Second, the requested type may not be the owner of its own vptr.
637 If not, convert to the base class that owns it. We cannot use
638 convert_to_base here, because VCONTEXT may appear more than once
639 in the inheritance hierarchy of TYPE, and thus direct conversion
640 between the types may be ambiguous. Following the path back up
641 one step at a time via primary bases avoids the problem. */
645 {
648 }
651 }
653 /* Given an object INSTANCE, return an expression which yields the
654 vtable element corresponding to INDEX. There are many special
655 cases for INSTANCE which we take care of here, mainly to avoid
656 creating extra tree nodes when we don't have to. */
658 static tree
660 {
661 tree aref;
664 /* Try to figure out what a reference refers to, and
665 access its virtual function table directly. */
673 {
678 }
687 }
689 tree
691 {
695 }
697 /* Given a stable object pointer INSTANCE_PTR, return an expression which
698 yields a function pointer corresponding to vtable element INDEX. */
700 tree
702 {
703 tree aref;
706 tf_warning_or_error),
707 idx);
709 /* When using function descriptors, the address of the
710 vtable entry is treated as a function pointer. */
715 /* Remember this as a method reference, for later devirtualization. */
719 }
721 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
722 for the given TYPE. */
724 static tree
726 {
728 }
730 /* DECL is an entity associated with TYPE, like a virtual table or an
731 implicitly generated constructor. Determine whether or not DECL
732 should have external or internal linkage at the object file
733 level. This routine does not deal with COMDAT linkage and other
734 similar complexities; it simply sets TREE_PUBLIC if it possible for
735 entities in other translation units to contain copies of DECL, in
736 the abstract. */
738 void
740 {
743 }
745 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
746 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
747 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
749 static tree
751 {
752 tree decl;
755 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
756 now to avoid confusion in mangle_decl. */
765 /* At one time the vtable info was grabbed 2 words at a time. This
766 fails on sparc unless you have 8-byte alignment. (tiemann) */
770 /* The vtable has not been defined -- yet. */
774 /* Mark the VAR_DECL node representing the vtable itself as a
775 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
776 is rather important that such things be ignored because any
777 effort to actually generate DWARF for them will run into
778 trouble when/if we encounter code like:
780 #pragma interface
781 struct S { virtual void member (); };
783 because the artificial declaration of the vtable itself (as
784 manufactured by the g++ front end) will say that the vtable is
785 a static member of `S' but only *after* the debug output for
786 the definition of `S' has already been output. This causes
787 grief because the DWARF entry for the definition of the vtable
788 will try to refer back to an earlier *declaration* of the
789 vtable as a static member of `S' and there won't be one. We
790 might be able to arrange to have the "vtable static member"
791 attached to the member list for `S' before the debug info for
792 `S' get written (which would solve the problem) but that would
793 require more intrusive changes to the g++ front end. */
797 }
799 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
800 or even complete. If this does not exist, create it. If COMPLETE is
801 nonzero, then complete the definition of it -- that will render it
802 impossible to actually build the vtable, but is useful to get at those
803 which are known to exist in the runtime. */
805 tree
807 {
808 tree decl;
817 {
820 }
823 }
825 /* Build the primary virtual function table for TYPE. If BINFO is
826 non-NULL, build the vtable starting with the initial approximation
827 that it is the same as the one which is the head of the association
828 list. Returns a nonzero value if a new vtable is actually
829 created. */
831 static int
833 {
834 tree decl;
835 tree virtuals;
840 {
842 /* We have already created a vtable for this base, so there's
843 no need to do it again. */
850 }
851 else
852 {
855 }
858 {
861 }
863 /* Initialize the association list for this type, based
864 on our first approximation. */
869 }
871 /* Give BINFO a new virtual function table which is initialized
872 with a skeleton-copy of its original initialization. The only
873 entry that changes is the `delta' entry, so we can really
874 share a lot of structure.
876 FOR_TYPE is the most derived type which caused this table to
877 be needed.
879 Returns nonzero if we haven't met BINFO before.
881 The order in which vtables are built (by calling this function) for
882 an object must remain the same, otherwise a binary incompatibility
883 can result. */
885 static int
887 {
889 /* We already created a vtable for this base. There's no need to
890 do it again. */
893 /* Remember that we've created a vtable for this BINFO, so that we
894 don't try to do so again. */
897 /* Make fresh virtual list, so we can smash it later. */
900 /* Secondary vtables are laid out as part of the same structure as
901 the primary vtable. */
904 }
906 /* Create a new vtable for BINFO which is the hierarchy dominated by
907 T. Return nonzero if we actually created a new vtable. */
909 static int
911 {
913 /* In this case, it is *type*'s vtable we are modifying. We start
914 with the approximation that its vtable is that of the
915 immediate base class. */
917 else
918 /* This is our very own copy of `basetype' to play with. Later,
919 we will fill in all the virtual functions that override the
920 virtual functions in these base classes which are not defined
921 by the current type. */
923 }
925 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
926 (which is in the hierarchy dominated by T) list FNDECL as its
927 BV_FN. DELTA is the required constant adjustment from the `this'
928 pointer where the vtable entry appears to the `this' required when
929 the function is actually called. */
931 static void
933 tree binfo,
934 tree fndecl,
935 tree delta,
937 {
938 tree v;
944 {
945 /* We need a new vtable for BINFO. */
947 {
948 /* If we really did make a new vtable, we also made a copy
949 of the BINFO_VIRTUALS list. Now, we have to find the
950 corresponding entry in that list. */
955 }
960 }
961 }
963 \f
964 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
965 the USING_DECL naming METHOD. Returns true if the method could be
966 added to the method vec. */
968 bool
970 {
972 tree overload;
978 tree current_fns;
979 tree fns;
992 {
993 /* Make a new method vector. We start with 8 entries. We must
994 allocate at least two (for constructors and destructors), and
995 we're going to end up with an assignment operator at some
996 point as well. */
998 /* Create slots for constructors and destructors. */
1002 }
1004 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1007 /* Constructors and destructors go in special slots. */
1011 {
1015 {
1021 type);
1022 }
1023 }
1024 else
1025 {
1026 tree m;
1029 /* See if we already have an entry with this name. */
1033 {
1036 {
1041 }
1045 {
1048 }
1053 }
1054 }
1057 /* Check to see if we've already got this method. */
1059 {
1061 tree fn_type;
1062 tree method_type;
1063 tree parms1;
1064 tree parms2;
1069 /* [over.load] Member function declarations with the
1070 same name and the same parameter types cannot be
1071 overloaded if any of them is a static member
1072 function declaration.
1074 [over.load] Member function declarations with the same name and
1075 the same parameter-type-list as well as member function template
1076 declarations with the same name, the same parameter-type-list, and
1077 the same template parameter lists cannot be overloaded if any of
1078 them, but not all, have a ref-qualifier.
1080 [namespace.udecl] When a using-declaration brings names
1081 from a base class into a derived class scope, member
1082 functions in the derived class override and/or hide member
1083 functions with the same name and parameter types in a base
1084 class (rather than conflicting). */
1090 /* Compare the quals on the 'this' parm. Don't compare
1091 the whole types, as used functions are treated as
1092 coming from the using class in overload resolution. */
1095 /* Either both or neither need to be ref-qualified for
1096 differing quals to allow overloading. */
1103 /* For templates, the return type and template parameters
1104 must be identical. */
1121 {
1122 /* For function versions, their parms and types match
1123 but they are not duplicates. Record function versions
1124 as and when they are found. extern "C" functions are
1125 not treated as versions. */
1131 {
1132 /* Mark functions as versions if necessary. Modify the mangled
1133 decl name if necessary. */
1135 {
1139 }
1141 {
1145 }
1148 }
1150 {
1152 {
1159 }
1160 /* Otherwise defer to the other function. */
1162 }
1164 {
1166 /* Defer to the local function. */
1168 }
1169 else
1170 {
1173 }
1175 /* We don't call duplicate_decls here to merge the
1176 declarations because that will confuse things if the
1177 methods have inline definitions. In particular, we
1178 will crash while processing the definitions. */
1180 }
1181 }
1183 /* A class should never have more than one destructor. */
1187 /* Add the new binding. */
1189 {
1192 }
1193 else
1202 {
1205 /* We only expect to add few methods in the COMPLETE_P case, so
1206 just make room for one more method in that case. */
1209 else
1215 else
1217 }
1218 else
1219 /* Replace the current slot. */
1222 }
1224 /* Subroutines of finish_struct. */
1226 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1227 legit, otherwise return 0. */
1229 static int
1231 {
1232 tree elem;
1241 {
1243 {
1247 else
1250 }
1251 else
1252 {
1253 /* They're changing the access to the same thing they changed
1254 it to before. That's OK. */
1255 ;
1256 }
1257 }
1258 else
1259 {
1261 tf_warning_or_error);
1264 }
1266 }
1268 /* Process the USING_DECL, which is a member of T. */
1270 static void
1272 {
1275 tree access
1280 tree old_value;
1285 tf_warning_or_error);
1287 {
1293 else
1295 }
1303 ;
1305 {
1307 /* It's OK to use functions from a base when there are functions with
1309 else
1310 {
1315 }
1316 }
1318 {
1322 }
1324 /* Make type T see field decl FDECL with access ACCESS. */
1327 {
1330 }
1331 else
1333 }
1334 \f
1335 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1336 types with abi tags, add the corresponding identifiers to the VEC in
1337 *DATA and set IDENTIFIER_MARKED. */
1339 struct abi_tag_data
1340 {
1341 tree t;
1342 tree subob;
1343 };
1345 static tree
1347 {
1352 {
1356 {
1360 {
1362 {
1367 }
1368 else
1369 {
1376 }
1377 }
1378 }
1379 }
1381 }
1383 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1384 complete) template arguments. */
1386 static void
1388 {
1391 {
1394 {
1398 }
1399 }
1401 /* Also mark ABI tags from template arguments. */
1403 {
1406 {
1409 {
1413 }
1414 }
1415 }
1416 }
1418 /* Check that class T has all the abi tags that subobject SUBOB has, or
1419 warn if not. */
1421 static void
1423 {
1432 }
1434 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1435 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1436 properties of the bases. */
1438 static void
1442 {
1446 tree base_binfo;
1447 tree binfo;
1457 {
1466 /* If any base class is non-literal, so is the derived class. */
1470 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1471 here because the case of virtual functions but non-virtual
1472 dtor is handled in finish_struct_1. */
1477 /* If the base class doesn't have copy constructors or
1478 assignment operators that take const references, then the
1479 derived class cannot have such a member automatically
1480 generated. */
1489 /* A virtual base does not effect nearly emptiness. */
1490 ;
1492 {
1494 /* And if there is more than one nearly empty base, then the
1495 derived class is not nearly empty either. */
1497 else
1498 /* Remember we've seen one. */
1500 }
1502 /* If the base class is not empty or nearly empty, then this
1503 class cannot be nearly empty. */
1506 /* A lot of properties from the bases also apply to the derived
1507 class. */
1524 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1527 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1531 /* A standard-layout class is a class that:
1532 ...
1533 * has no non-standard-layout base classes, */
1536 {
1537 tree basefield;
1538 /* ...has no base classes of the same type as the first non-static
1539 data member... */
1541 && (same_type_ignoring_top_level_qualifiers_p
1544 else
1545 /* ...either has no non-static data members in the most-derived
1546 class and at most one base class with non-static data
1547 members, or has no base classes with non-static data
1548 members */
1552 {
1555 else
1558 }
1559 }
1561 /* Don't bother collecting tm attributes if transactional memory
1562 support is not enabled. */
1564 {
1568 }
1571 }
1573 /* If one of the base classes had TM attributes, and the current class
1574 doesn't define its own, then the current class inherits one. */
1576 {
1579 }
1580 }
1582 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1583 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1584 that have had a nearly-empty virtual primary base stolen by some
1585 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1586 T. */
1588 static void
1590 {
1594 tree base_binfo;
1596 /* Determine the primary bases of our bases. */
1599 {
1602 /* See if we're the non-virtual primary of our inheritance
1603 chain. */
1605 {
1612 /* We are the primary binfo. */
1614 }
1615 /* Determine if we have a virtual primary base, and mark it so.
1616 */
1618 {
1622 /* Someone already claimed this base. */
1624 else
1625 {
1626 tree delta;
1631 /* A virtual binfo might have been copied from within
1632 another hierarchy. As we're about to use it as a
1633 primary base, make sure the offsets match. */
1641 }
1642 }
1643 }
1645 /* First look for a dynamic direct non-virtual base. */
1647 {
1651 {
1654 }
1655 }
1657 /* A "nearly-empty" virtual base class can be the primary base
1658 class, if no non-virtual polymorphic base can be found. Look for
1659 a nearly-empty virtual dynamic base that is not already a primary
1660 base of something in the hierarchy. If there is no such base,
1661 just pick the first nearly-empty virtual base. */
1667 {
1669 {
1670 /* Found one that is not primary. */
1673 }
1675 /* Remember the first candidate. */
1677 }
1679 found:
1680 /* If we've got a primary base, use it. */
1682 {
1687 /* We are stealing a primary base. */
1691 {
1692 tree delta;
1695 /* A virtual binfo might have been copied from within
1696 another hierarchy. As we're about to use it as a primary
1697 base, make sure the offsets match. */
1702 }
1709 }
1710 }
1712 /* Update the variant types of T. */
1714 void
1716 {
1717 tree variants;
1723 variants;
1725 {
1726 /* These fields are in the _TYPE part of the node, not in
1727 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1737 /* Copy whatever these are holding today. */
1741 }
1742 }
1744 /* Early variant fixups: we apply attributes at the beginning of the class
1745 definition, and we need to fix up any variants that have already been
1746 made via elaborated-type-specifier so that check_qualified_type works. */
1748 void
1750 {
1751 tree variants;
1757 variants;
1759 {
1760 /* These are the two fields that check_qualified_type looks at and
1761 are affected by attributes. */
1764 }
1765 }
1766 \f
1767 /* Set memoizing fields and bits of T (and its variants) for later
1768 use. */
1770 static void
1772 {
1773 /* Fix up variants (if any). */
1777 /* For a class w/o baseclasses, 'finish_struct' has set
1778 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1779 Similarly for a class whose base classes do not have vtables.
1780 When neither of these is true, we might have removed abstract
1781 virtuals (by providing a definition), added some (by declaring
1782 new ones), or redeclared ones from a base class. We need to
1783 recalculate what's really an abstract virtual at this point (by
1784 looking in the vtables). */
1787 /* If this type has a copy constructor or a destructor, force its
1788 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1789 nonzero. This will cause it to be passed by invisible reference
1790 and prevent it from being returned in a register. */
1793 {
1794 tree variants;
1797 {
1800 }
1801 }
1802 }
1804 /* Issue warnings about T having private constructors, but no friends,
1805 and so forth.
1807 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1808 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1809 non-private static member functions. */
1811 static void
1813 {
1816 tree fn;
1819 /* If the class has friends, those entities might create and
1820 access instances, so we should not warn. */
1823 /* We will have warned when the template was declared; there's
1824 no need to warn on every instantiation. */
1826 /* There's no reason to even consider warning about this
1827 class. */
1830 /* We only issue one warning, if more than one applies, because
1831 otherwise, on code like:
1833 class A {
1834 // Oops - forgot `public:'
1835 A();
1836 A(const A&);
1837 ~A();
1838 };
1840 we warn several times about essentially the same problem. */
1842 /* Check to see if all (non-constructor, non-destructor) member
1843 functions are private. (Since there are no friends or
1844 non-private statics, we can't ever call any of the private member
1845 functions.) */
1847 /* We're not interested in compiler-generated methods; they don't
1848 provide any way to call private members. */
1850 {
1852 {
1854 /* A non-private static member function is just like a
1855 friend; it can create and invoke private member
1856 functions, and be accessed without a class
1857 instance. */
1861 /* Keep searching for a static member function. */
1862 }
1865 }
1868 {
1869 /* There are no non-private methods, and there's at least one
1870 private member function that isn't a constructor or
1871 destructor. (If all the private members are
1872 constructors/destructors we want to use the code below that
1873 issues error messages specifically referring to
1874 constructors/destructors.) */
1880 {
1883 }
1885 {
1889 }
1890 }
1892 /* Even if some of the member functions are non-private, the class
1893 won't be useful for much if all the constructors or destructors
1894 are private: such an object can never be created or destroyed. */
1897 {
1900 t);
1902 }
1904 /* Warn about classes that have private constructors and no friends. */
1906 /* Implicitly generated constructors are always public. */
1909 {
1912 /* If a non-template class does not define a copy
1913 constructor, one is defined for it, enabling it to avoid
1914 this warning. For a template class, this does not
1915 happen, and so we would normally get a warning on:
1917 template <class T> class C { private: C(); };
1919 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1920 complete non-template or fully instantiated classes have this
1921 flag set. */
1924 else
1926 {
1928 /* Ideally, we wouldn't count copy constructors (or, in
1929 fact, any constructor that takes an argument of the
1930 class type as a parameter) because such things cannot
1931 be used to construct an instance of the class unless
1932 you already have one. But, for now at least, we're
1933 more generous. */
1935 {
1938 }
1939 }
1942 {
1945 t);
1947 }
1948 }
1949 }
1952 gt_pointer_operator new_value;
1956 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1958 static int
1960 {
1973 }
1975 /* This routine compares two fields like method_name_cmp but using the
1976 pointer operator in resort_field_decl_data. */
1978 static int
1980 {
1989 {
1996 }
1998 }
2000 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2002 void
2005 gt_pointer_operator new_value,
2007 {
2011 tree fn;
2013 /* The type conversion ops have to live at the front of the vec, so we
2014 can't sort them. */
2022 {
2026 resort_method_name_cmp);
2027 }
2028 }
2030 /* Warn about duplicate methods in fn_fields.
2032 Sort methods that are not special (i.e., constructors, destructors,
2033 and type conversion operators) so that we can find them faster in
2034 search. */
2036 static void
2038 {
2039 tree fn_fields;
2049 /* Clear DECL_IN_AGGR_P for all functions. */
2054 /* Issue warnings about private constructors and such. If there are
2055 no methods, then some public defaults are generated. */
2058 /* The type conversion ops have to live at the front of the vec, so we
2059 can't sort them. */
2068 }
2070 /* Make BINFO's vtable have N entries, including RTTI entries,
2071 vbase and vcall offsets, etc. Set its type and call the back end
2072 to lay it out. */
2074 static void
2076 {
2077 tree atype;
2078 tree vtable;
2083 /* We may have to grow the vtable. */
2086 {
2090 }
2091 }
2093 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2094 have the same signature. */
2096 int
2098 {
2099 /* One destructor overrides another if they are the same kind of
2100 destructor. */
2104 /* But a non-destructor never overrides a destructor, nor vice
2105 versa, nor do different kinds of destructors override
2106 one-another. For example, a complete object destructor does not
2107 override a deleting destructor. */
2116 {
2124 }
2126 }
2128 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2129 subobject. */
2131 static bool
2133 {
2134 tree probe;
2137 {
2141 /* If we meet a virtual base, we can't follow the inheritance
2142 any more. See if the complete type of DERIVED contains
2143 such a virtual base. */
2146 }
2148 }
2151 /* The function for which we are trying to find a final overrider. */
2152 tree fn;
2153 /* The base class in which the function was declared. */
2154 tree declaring_base;
2155 /* The candidate overriders. */
2156 tree candidates;
2157 /* Path to most derived. */
2161 /* Add the overrider along the current path to FFOD->CANDIDATES.
2162 Returns true if an overrider was found; false otherwise. */
2164 static bool
2168 {
2169 tree method;
2171 /* If BINFO is not the most derived type, try a more derived class.
2172 A definition there will overrider a definition here. */
2174 {
2175 depth--;
2179 }
2183 {
2186 /* Remove any candidates overridden by this new function. */
2188 {
2189 /* If *CANDIDATE overrides METHOD, then METHOD
2190 cannot override anything else on the list. */
2193 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2196 else
2198 }
2200 /* Add the new function. */
2203 }
2206 }
2208 /* Called from find_final_overrider via dfs_walk. */
2210 static tree
2212 {
2220 }
2222 static tree
2224 {
2229 }
2231 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2232 FN and whose TREE_VALUE is the binfo for the base where the
2233 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2234 DERIVED) is the base object in which FN is declared. */
2236 static tree
2238 {
2239 find_final_overrider_data ffod;
2241 /* Getting this right is a little tricky. This is valid:
2243 struct S { virtual void f (); };
2244 struct T { virtual void f (); };
2245 struct U : public S, public T { };
2247 even though calling `f' in `U' is ambiguous. But,
2249 struct R { virtual void f(); };
2250 struct S : virtual public R { virtual void f (); };
2251 struct T : virtual public R { virtual void f (); };
2252 struct U : public S, public T { };
2254 is not -- there's no way to decide whether to put `S::f' or
2255 `T::f' in the vtable for `R'.
2257 The solution is to look at all paths to BINFO. If we find
2258 different overriders along any two, then there is a problem. */
2262 /* Determine the depth of the hierarchy. */
2273 /* If there was no winner, issue an error message. */
2278 }
2280 /* Return the index of the vcall offset for FN when TYPE is used as a
2281 virtual base. */
2283 static tree
2285 {
2287 tree_pair_p p;
2295 /* There should always be an appropriate index. */
2297 }
2299 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2300 dominated by T. FN is the old function; VIRTUALS points to the
2301 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2302 of that entry in the list. */
2304 static void
2307 {
2308 tree b;
2309 tree overrider;
2310 tree delta;
2311 tree virtual_base;
2312 tree first_defn;
2318 /* Find the nearest primary base (possibly binfo itself) which defines
2319 this function; this is the class the caller will convert to when
2320 calling FN through BINFO. */
2322 {
2327 /* The nearest definition is from a lost primary. */
2330 }
2333 /* Find the final overrider. */
2336 {
2339 }
2342 /* Check for adjusting covariant return types. */
2350 /* If the overrider is invalid, don't even try. */
2352 {
2353 /* If FN is a covariant thunk, we must figure out the adjustment
2354 to the final base FN was converting to. As OVERRIDER_TARGET might
2355 also be converting to the return type of FN, we have to
2356 combine the two conversions here. */
2363 {
2367 }
2368 else
2372 /* Find the equivalent binfo within the return type of the
2373 overriding function. We will want the vbase offset from
2374 there. */
2376 over_return);
2379 {
2380 /* There was no existing virtual thunk (which takes
2381 precedence). So find the binfo of the base function's
2382 return type within the overriding function's return type.
2383 We cannot call lookup base here, because we're inside a
2384 dfs_walk, and will therefore clobber the BINFO_MARKED
2385 flags. Fortunately we know the covariancy is valid (it
2386 has already been checked), so we can just iterate along
2387 the binfos, which have been chained in inheritance graph
2388 order. Of course it is lame that we have to repeat the
2389 search here anyway -- we should really be caching pieces
2390 of the vtable and avoiding this repeated work. */
2393 /* Find the base binfo within the overriding function's
2394 return type. We will always find a thunk_binfo, except
2395 when the covariancy is invalid (which we will have
2396 already diagnosed). */
2399 thunk_binfo;
2405 /* See if virtual inheritance is involved. */
2407 virtual_offset;
2414 {
2418 {
2419 /* We convert via virtual base. Adjust the fixed
2420 offset to be from there. */
2421 offset =
2425 }
2427 /* There was an existing fixed offset, this must be
2428 from the base just converted to, and the base the
2429 FN was thunking to. */
2431 else
2433 }
2434 }
2437 /* Replace the overriding function with a covariant thunk. We
2438 will emit the overriding function in its own slot as
2439 well. */
2442 }
2443 else
2447 /* If we need a covariant thunk, then we may need to adjust first_defn.
2448 The ABI specifies that the thunks emitted with a function are
2449 determined by which bases the function overrides, so we need to be
2450 sure that we're using a thunk for some overridden base; even if we
2451 know that the necessary this adjustment is zero, there may not be an
2452 appropriate zero-this-adjusment thunk for us to use since thunks for
2453 overriding virtual bases always use the vcall offset.
2455 Furthermore, just choosing any base that overrides this function isn't
2456 quite right, as this slot won't be used for calls through a type that
2457 puts a covariant thunk here. Calling the function through such a type
2458 will use a different slot, and that slot is the one that determines
2459 the thunk emitted for that base.
2461 So, keep looking until we find the base that we're really overriding
2462 in this slot: the nearest primary base that doesn't use a covariant
2463 thunk in this slot. */
2465 {
2467 /* We already know that the overrider needs a covariant thunk. */
2470 {
2477 }
2479 }
2481 /* Assume that we will produce a thunk that convert all the way to
2482 the final overrider, and not to an intermediate virtual base. */
2485 /* See if we can convert to an intermediate virtual base first, and then
2486 use the vcall offset located there to finish the conversion. */
2488 {
2489 /* If we find the final overrider, then we can stop
2490 walking. */
2495 /* If we find a virtual base, and we haven't yet found the
2496 overrider, then there is a virtual base between the
2497 declaring base (first_defn) and the final overrider. */
2499 {
2502 }
2503 }
2505 /* Compute the constant adjustment to the `this' pointer. The
2506 `this' pointer, when this function is called, will point at BINFO
2507 (or one of its primary bases, which are at the same offset). */
2509 /* The `this' pointer needs to be adjusted from the declaration to
2510 the nearest virtual base. */
2515 /* If the nearest definition is in a lost primary, we don't need an
2516 entry in our vtable. Except possibly in a constructor vtable,
2517 if we happen to get our primary back. In that case, the offset
2518 will be zero, as it will be a primary base. */
2520 else
2521 /* The `this' pointer needs to be adjusted from pointing to
2522 BINFO to pointing at the base where the final overrider
2523 appears. */
2534 else
2538 }
2540 /* Called from modify_all_vtables via dfs_walk. */
2542 static tree
2544 {
2546 tree virtuals;
2547 tree old_virtuals;
2551 /* A base without a vtable needs no modification, and its bases
2552 are uninteresting. */
2557 /* Don't do the primary vtable, if it's new. */
2561 /* There's no need to modify the vtable for a non-virtual primary
2562 base; we're not going to use that vtable anyhow. We do still
2563 need to do this for virtual primary bases, as they could become
2564 non-primary in a construction vtable. */
2569 /* Now, go through each of the virtual functions in the virtual
2570 function table for BINFO. Find the final overrider, and update
2571 the BINFO_VIRTUALS list appropriately. */
2574 virtuals;
2578 binfo,
2583 }
2585 /* Update all of the primary and secondary vtables for T. Create new
2586 vtables as required, and initialize their RTTI information. Each
2587 of the functions in VIRTUALS is declared in T and may override a
2588 virtual function from a base class; find and modify the appropriate
2589 entries to point to the overriding functions. Returns a list, in
2590 declaration order, of the virtual functions that are declared in T,
2591 but do not appear in the primary base class vtable, and which
2592 should therefore be appended to the end of the vtable for T. */
2594 static tree
2596 {
2600 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2604 /* Update all of the vtables. */
2607 /* Add virtual functions not already in our primary vtable. These
2608 will be both those introduced by this class, and those overridden
2609 from secondary bases. It does not include virtuals merely
2610 inherited from secondary bases. */
2612 {
2617 {
2618 /* We don't need to adjust the `this' pointer when
2619 calling this function. */
2623 /* This is a function not already in our vtable. Keep it. */
2625 }
2626 else
2627 /* We've already got an entry for this function. Skip it. */
2629 }
2632 }
2634 /* Get the base virtual function declarations in T that have the
2635 indicated NAME. */
2637 static tree
2639 {
2640 tree methods;
2645 /* Find virtual functions in T with the indicated NAME. */
2649 methods;
2651 {
2657 }
2663 {
2666 base_fndecls);
2667 }
2670 }
2672 /* If this declaration supersedes the declaration of
2673 a method declared virtual in the base class, then
2674 mark this field as being virtual as well. */
2676 void
2678 {
2681 /* In [temp.mem] we have:
2683 A specialization of a member function template does not
2684 override a virtual function from a base class. */
2691 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2692 the error_mark_node so that we know it is an overriding
2693 function. */
2694 {
2697 }
2700 {
2706 }
2711 }
2713 /* Warn about hidden virtual functions that are not overridden in t.
2714 We know that constructors and destructors don't apply. */
2716 static void
2718 {
2720 tree fns;
2723 /* We go through each separately named virtual function. */
2727 {
2728 tree fn;
2729 tree name;
2730 tree fndecl;
2731 tree base_fndecls;
2732 tree base_binfo;
2733 tree binfo;
2736 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2737 have the same name. Figure out what name that is. */
2739 /* There are no possibly hidden functions yet. */
2741 /* Iterate through all of the base classes looking for possibly
2742 hidden functions. */
2745 {
2748 base_fndecls);
2749 }
2751 /* If there are no functions to hide, continue. */
2755 /* Remove any overridden functions. */
2757 {
2760 {
2764 /* If the method from the base class has the same
2765 signature as the method from the derived class, it
2766 has been overridden. */
2769 else
2771 }
2772 }
2774 /* Now give a warning for all base functions without overriders,
2775 as they are hidden. */
2777 {
2778 /* Here we know it is a hider, and no overrider exists. */
2782 }
2783 }
2784 }
2786 /* Recursive helper for finish_struct_anon. */
2788 static void
2790 {
2794 {
2795 /* We're generally only interested in entities the user
2796 declared, but we also find nested classes by noticing
2797 the TYPE_DECL that we create implicitly. You're
2798 allowed to put one anonymous union inside another,
2799 though, so we explicitly tolerate that. We use
2800 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2801 we also allow unnamed types used for defining fields. */
2808 {
2810 {
2813 "%q+#D invalid; an anonymous union can "
2815 else
2817 "%q+#D invalid; an anonymous struct can "
2819 }
2821 }
2824 {
2826 {
2830 else
2833 }
2835 {
2839 else
2842 }
2843 }
2848 /* Recurse into the anonymous aggregates to handle correctly
2849 access control (c++/24926):
2851 class A {
2852 union {
2853 union {
2854 int i;
2855 };
2856 };
2857 };
2859 int j=A().i; */
2863 }
2864 }
2866 /* Check for things that are invalid. There are probably plenty of other
2867 things we should check for also. */
2869 static void
2871 {
2873 {
2882 }
2883 }
2885 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2886 will be used later during class template instantiation.
2887 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2888 a non-static member data (FIELD_DECL), a member function
2889 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2890 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2891 When FRIEND_P is nonzero, T is either a friend class
2892 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2893 (FUNCTION_DECL, TEMPLATE_DECL). */
2895 void
2897 {
2898 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2903 }
2905 /* This function is called from declare_virt_assop_and_dtor via
2906 dfs_walk_all.
2908 DATA is a type that direcly or indirectly inherits the base
2909 represented by BINFO. If BINFO contains a virtual assignment [copy
2910 assignment or move assigment] operator or a virtual constructor,
2911 declare that function in DATA if it hasn't been already declared. */
2913 static tree
2915 {
2923 /* A base without a vtable needs no modification, and its bases
2924 are uninteresting. */
2928 /* If this is a primary base, then we have already looked at the
2929 virtual functions of its vtable. */
2933 {
2937 {
2942 }
2946 }
2949 }
2951 /* If the class type T has a direct or indirect base that contains a
2952 virtual assignment operator or a virtual destructor, declare that
2953 function in T if it hasn't been already declared. */
2955 static void
2957 {
2965 dfs_declare_virt_assop_and_dtor,
2967 }
2969 /* Declare the inheriting constructor for class T inherited from base
2970 constructor CTOR with the parameter array PARMS of size NPARMS. */
2972 static void
2974 {
2975 /* We don't declare an inheriting ctor that would be a default,
2976 copy or move ctor for derived or base. */
2981 {
2985 }
2993 {
2996 }
2997 }
2999 /* Declare all the inheriting constructors for class T inherited from base
3000 constructor CTOR. */
3002 static void
3004 {
3010 {
3014 }
3017 {
3021 }
3022 }
3024 /* Create default constructors, assignment operators, and so forth for
3025 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3026 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3027 the class cannot have a default constructor, copy constructor
3028 taking a const reference argument, or an assignment operator taking
3029 a const reference, respectively. */
3031 static void
3035 {
3043 /* Destructor. */
3045 {
3046 /* In general, we create destructors lazily. */
3051 /* But if this is a Java class, any non-trivial destructor is
3052 invalid, even if compiler-generated. Therefore, if the
3053 destructor is non-trivial we create it now. */
3055 }
3057 /* [class.ctor]
3059 If there is no user-declared constructor for a class, a default
3060 constructor is implicitly declared. */
3062 {
3067 /* This might force the declaration. */
3069 }
3071 /* [class.ctor]
3073 If a class definition does not explicitly declare a copy
3074 constructor, one is declared implicitly. */
3076 {
3082 }
3084 /* If there is no assignment operator, one will be created if and
3085 when it is needed. For now, just record whether or not the type
3086 of the parameter to the assignment operator will be a const or
3087 non-const reference. */
3089 {
3095 }
3097 /* We can't be lazy about declaring functions that might override
3098 a virtual function from a base class. */
3102 {
3106 {
3107 /* declare, then remove the decl */
3116 }
3117 else
3119 }
3120 }
3122 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3123 count the number of fields in TYPE, including anonymous union
3124 members. */
3126 static int
3128 {
3129 tree x;
3132 {
3135 else
3137 }
3139 }
3141 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3142 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3143 elts, starting at offset IDX. */
3145 static int
3147 {
3148 tree x;
3150 {
3153 else
3155 }
3157 }
3159 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3160 starting at offset IDX. */
3162 static int
3166 {
3167 tree values;
3171 }
3173 /* FIELD is a bit-field. We are finishing the processing for its
3174 enclosing type. Issue any appropriate messages and set appropriate
3175 flags. Returns false if an error has been diagnosed. */
3177 static bool
3179 {
3181 tree w;
3183 /* Extract the declared width of the bitfield, which has been
3184 temporarily stashed in DECL_INITIAL. */
3187 /* Remove the bit-field width indicator so that the rest of the
3188 compiler does not treat that value as an initializer. */
3191 /* Detect invalid bit-field type. */
3193 {
3196 }
3197 else
3198 {
3200 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3203 /* detect invalid field size. */
3209 {
3212 }
3214 {
3217 }
3219 {
3222 }
3234 }
3237 {
3241 }
3242 else
3243 {
3244 /* Non-bit-fields are aligned for their type. */
3248 }
3249 }
3251 /* FIELD is a non bit-field. We are finishing the processing for its
3252 enclosing type T. Issue any appropriate messages and set appropriate
3253 flags. */
3255 static void
3257 tree t,
3261 {
3264 /* In C++98 an anonymous union cannot contain any fields which would change
3265 the settings of CANT_HAVE_CONST_CTOR and friends. */
3267 ;
3268 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3269 structs. So, we recurse through their fields here. */
3271 {
3272 tree fields;
3278 }
3279 /* Check members with class type for constructors, destructors,
3280 etc. */
3282 {
3283 /* Never let anything with uninheritable virtuals
3284 make it through without complaint. */
3288 {
3293 field);
3298 field);
3300 {
3304 }
3305 }
3306 else
3307 {
3320 }
3329 }
3334 {
3335 /* `build_class_init_list' does not recognize
3336 non-FIELD_DECLs. */
3340 }
3341 }
3343 /* Check the data members (both static and non-static), class-scoped
3344 typedefs, etc., appearing in the declaration of T. Issue
3345 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3346 declaration order) of access declarations; each TREE_VALUE in this
3347 list is a USING_DECL.
3349 In addition, set the following flags:
3351 EMPTY_P
3352 The class is empty, i.e., contains no non-static data members.
3354 CANT_HAVE_CONST_CTOR_P
3355 This class cannot have an implicitly generated copy constructor
3356 taking a const reference.
3358 CANT_HAVE_CONST_ASN_REF
3359 This class cannot have an implicitly generated assignment
3360 operator taking a const reference.
3362 All of these flags should be initialized before calling this
3363 function.
3365 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3366 fields can be added by adding to this chain. */
3368 static void
3372 {
3380 /* Assume there are no access declarations. */
3382 /* Assume this class has no pointer members. */
3384 /* Assume none of the members of this class have default
3385 initializations. */
3389 {
3397 {
3398 /* Save the access declarations for our caller. */
3401 }
3407 /* If we've gotten this far, it's a data member, possibly static,
3408 or an enumerator. */
3412 /* When this goes into scope, it will be a non-local reference. */
3416 {
3417 /* [class.union]
3419 If a union contains a static data member, or a member of
3420 reference type, the program is ill-formed. */
3422 {
3425 }
3427 {
3432 }
3433 }
3435 /* Perform error checking that did not get done in
3436 grokdeclarator. */
3438 {
3442 }
3444 {
3448 }
3456 /* Now it can only be a FIELD_DECL. */
3461 /* If at least one non-static data member is non-literal, the whole
3462 class becomes non-literal. Note: if the type is incomplete we
3463 will complain later on. */
3467 /* A standard-layout class is a class that:
3468 ...
3469 has the same access control (Clause 11) for all non-static data members,
3470 ... */
3477 /* If this is of reference type, check if it needs an init. */
3479 {
3485 /* ARM $12.6.2: [A member initializer list] (or, for an
3486 aggregate, initialization by a brace-enclosed list) is the
3487 only way to initialize nonstatic const and reference
3488 members. */
3491 }
3496 {
3498 {
3499 warning
3502 x);
3504 }
3508 }
3511 /* We don't treat zero-width bitfields as making a class
3512 non-empty. */
3513 ;
3514 else
3515 {
3516 /* The class is non-empty. */
3518 /* The class is not even nearly empty. */
3520 /* If one of the data members contains an empty class,
3521 so does T. */
3525 }
3527 /* This is used by -Weffc++ (see below). Warn only for pointers
3528 to members which might hold dynamic memory. So do not warn
3529 for pointers to functions or pointers to members. */
3535 {
3540 }
3546 {
3548 {
3552 }
3554 {
3558 }
3559 }
3562 /* DR 148 now allows pointers to members (which are POD themselves),
3563 to be allowed in POD structs. */
3572 /* We set DECL_C_BIT_FIELD in grokbitfield.
3573 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3576 cant_have_const_ctor_p,
3577 no_const_asn_ref_p,
3580 /* Now that we've removed bit-field widths from DECL_INITIAL,
3581 anything left in DECL_INITIAL is an NSDMI that makes the class
3582 non-aggregate. */
3586 /* If any field is const, the structure type is pseudo-const. */
3588 {
3593 /* ARM $12.6.2: [A member initializer list] (or, for an
3594 aggregate, initialization by a brace-enclosed list) is the
3595 only way to initialize nonstatic const and reference
3596 members. */
3599 }
3600 /* A field that is pseudo-const makes the structure likewise. */
3602 {
3607 }
3609 /* Core issue 80: A nonstatic data member is required to have a
3610 different name from the class iff the class has a
3611 user-declared constructor. */
3615 }
3617 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3618 it should also define a copy constructor and an assignment operator to
3619 implement the correct copy semantic (deep vs shallow, etc.). As it is
3620 not feasible to check whether the constructors do allocate dynamic memory
3621 and store it within members, we approximate the warning like this:
3623 -- Warn only if there are members which are pointers
3624 -- Warn only if there is a non-trivial constructor (otherwise,
3625 there cannot be memory allocated).
3626 -- Warn only if there is a non-trivial destructor. We assume that the
3627 user at least implemented the cleanup correctly, and a destructor
3628 is needed to free dynamic memory.
3630 This seems enough for practical purposes. */
3632 && has_pointers
3636 {
3640 {
3645 }
3649 }
3651 /* Non-static data member initializers make the default constructor
3652 non-trivial. */
3654 {
3657 }
3659 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3663 /* Check anonymous struct/anonymous union fields. */
3666 /* We've built up the list of access declarations in reverse order.
3667 Fix that now. */
3669 }
3671 /* If TYPE is an empty class type, records its OFFSET in the table of
3672 OFFSETS. */
3674 static int
3676 {
3677 splay_tree_node n;
3682 /* Record the location of this empty object in OFFSETS. */
3690 type,
3694 }
3696 /* Returns nonzero if TYPE is an empty class type and there is
3697 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3699 static int
3701 {
3702 splay_tree_node n;
3703 tree t;
3708 /* Record the location of this empty object in OFFSETS. */
3718 }
3720 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3721 F for every subobject, passing it the type, offset, and table of
3722 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3723 be traversed.
3725 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3726 than MAX_OFFSET will not be walked.
3728 If F returns a nonzero value, the traversal ceases, and that value
3729 is returned. Otherwise, returns zero. */
3731 static int
3733 subobject_offset_fn f,
3734 tree offset,
3735 splay_tree offsets,
3736 tree max_offset,
3738 {
3742 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3743 stop. */
3751 {
3755 }
3758 {
3759 tree field;
3760 tree binfo;
3763 /* Avoid recursing into objects that are not interesting. */
3767 /* Record the location of TYPE. */
3772 /* Iterate through the direct base classes of TYPE. */
3776 {
3777 tree binfo_offset;
3790 offset,
3792 else
3793 {
3794 tree orig_binfo;
3795 /* We cannot rely on BINFO_OFFSET being set for the base
3796 class yet, but the offsets for direct non-virtual
3797 bases can be calculated by going back to the TYPE. */
3800 offset,
3802 }
3805 f,
3806 binfo_offset,
3807 offsets,
3808 max_offset,
3813 }
3816 {
3820 /* Iterate through the virtual base classes of TYPE. In G++
3821 3.2, we included virtual bases in the direct base class
3822 loop above, which results in incorrect results; the
3823 correct offsets for virtual bases are only known when
3824 working with the most derived type. */
3828 {
3830 f,
3832 offset,
3834 offsets,
3835 max_offset,
3839 }
3840 else
3841 {
3842 /* We still have to walk the primary base, if it is
3843 virtual. (If it is non-virtual, then it was walked
3844 above.) */
3850 {
3851 r = (walk_subobject_offsets
3856 }
3857 }
3858 }
3860 /* Iterate through the fields of TYPE. */
3865 {
3866 tree field_offset;
3870 else
3871 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3875 f,
3877 offset,
3878 field_offset),
3879 offsets,
3880 max_offset,
3884 }
3885 }
3887 {
3890 tree index;
3892 /* Avoid recursing into objects that are not interesting. */
3897 /* Step through each of the elements in the array. */
3899 /* G++ 3.2 had an off-by-one error here. */
3904 {
3906 f,
3907 offset,
3908 offsets,
3909 max_offset,
3915 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3916 there's no point in iterating through the remaining
3917 elements of the array. */
3920 }
3921 }
3924 }
3926 /* Record all of the empty subobjects of TYPE (either a type or a
3927 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3928 is being placed at OFFSET; otherwise, it is a base class that is
3929 being placed at OFFSET. */
3931 static void
3933 tree offset,
3934 splay_tree offsets,
3936 {
3937 tree max_offset;
3938 /* If recording subobjects for a non-static data member or a
3939 non-empty base class , we do not need to record offsets beyond
3940 the size of the biggest empty class. Additional data members
3941 will go at the end of the class. Additional base classes will go
3942 either at offset zero (if empty, in which case they cannot
3943 overlap with offsets past the size of the biggest empty class) or
3944 at the end of the class.
3946 However, if we are placing an empty base class, then we must record
3947 all offsets, as either the empty class is at offset zero (where
3948 other empty classes might later be placed) or at the end of the
3949 class (where other objects might then be placed, so other empty
3950 subobjects might later overlap). */
3954 else
3958 }
3960 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3961 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3962 virtual bases of TYPE are examined. */
3964 static int
3966 tree offset,
3967 splay_tree offsets,
3969 {
3970 splay_tree_node max_node;
3972 /* Get the node in OFFSETS that indicates the maximum offset where
3973 an empty subobject is located. */
3975 /* If there aren't any empty subobjects, then there's no point in
3976 performing this check. */
3982 vbases_p);
3983 }
3985 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3986 non-static data member of the type indicated by RLI. BINFO is the
3987 binfo corresponding to the base subobject, OFFSETS maps offsets to
3988 types already located at those offsets. This function determines
3989 the position of the DECL. */
3991 static void
3993 tree decl,
3994 tree binfo,
3995 splay_tree offsets)
3996 {
3999 tree type;
4002 {
4003 /* For the purposes of determining layout conflicts, we want to
4004 use the class type of BINFO; TREE_TYPE (DECL) will be the
4005 CLASSTYPE_AS_BASE version, which does not contain entries for
4006 zero-sized bases. */
4009 }
4010 else
4011 {
4014 }
4016 /* Try to place the field. It may take more than one try if we have
4017 a hard time placing the field without putting two objects of the
4018 same type at the same address. */
4020 {
4023 /* Place this field. */
4027 /* We have to check to see whether or not there is already
4028 something of the same type at the offset we're about to use.
4029 For example, consider:
4031 struct S {};
4032 struct T : public S { int i; };
4033 struct U : public S, public T {};
4035 Here, we put S at offset zero in U. Then, we can't put T at
4036 offset zero -- its S component would be at the same address
4037 as the S we already allocated. So, we have to skip ahead.
4038 Since all data members, including those whose type is an
4039 empty class, have nonzero size, any overlap can happen only
4040 with a direct or indirect base-class -- it can't happen with
4041 a data member. */
4042 /* In a union, overlap is permitted; all members are placed at
4043 offset zero. */
4046 /* G++ 3.2 did not check for overlaps when placing a non-empty
4047 virtual base. */
4052 {
4053 /* Strip off the size allocated to this field. That puts us
4054 at the first place we could have put the field with
4055 proper alignment. */
4058 /* Bump up by the alignment required for the type. */
4059 rli->bitpos
4065 }
4066 else
4067 /* There was no conflict. We're done laying out this field. */
4069 }
4071 /* Now that we know where it will be placed, update its
4072 BINFO_OFFSET. */
4074 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4075 this point because their BINFO_OFFSET is copied from another
4076 hierarchy. Therefore, we may not need to add the entire
4077 OFFSET. */
4083 }
4085 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4087 static int
4089 tree offset,
4091 {
4093 }
4095 /* Layout the empty base BINFO. EOC indicates the byte currently just
4096 past the end of the class, and should be correctly aligned for a
4097 class of the type indicated by BINFO; OFFSETS gives the offsets of
4098 the empty bases allocated so far. T is the most derived
4099 type. Return nonzero iff we added it at the end. */
4101 static bool
4104 {
4105 tree alignment;
4109 /* This routine should only be used for empty classes. */
4114 {
4116 propagate_binfo_offsets
4119 else
4121 "offset of empty base %qT may not be ABI-compliant and may"
4124 }
4126 /* This is an empty base class. We first try to put it at offset
4127 zero. */
4130 offsets,
4132 {
4133 /* That didn't work. Now, we move forward from the next
4134 available spot in the class. */
4138 {
4141 offsets,
4143 /* We finally found a spot where there's no overlap. */
4146 /* There's overlap here, too. Bump along to the next spot. */
4148 }
4149 }
4152 {
4157 }
4160 }
4162 /* Layout the base given by BINFO in the class indicated by RLI.
4163 *BASE_ALIGN is a running maximum of the alignments of
4164 any base class. OFFSETS gives the location of empty base
4165 subobjects. T is the most derived type. Return nonzero if the new
4166 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4167 *NEXT_FIELD, unless BINFO is for an empty base class.
4169 Returns the location at which the next field should be inserted. */
4174 {
4179 /* This error is now reported in xref_tag, thus giving better
4180 location information. */
4183 /* Place the base class. */
4185 {
4186 tree decl;
4188 /* The containing class is non-empty because it has a non-empty
4189 base class. */
4192 /* Create the FIELD_DECL. */
4199 {
4207 /* Try to place the field. It may take more than one try if we
4208 have a hard time placing the field without putting two
4209 objects of the same type at the same address. */
4211 /* Add the new FIELD_DECL to the list of fields for T. */
4215 }
4216 }
4217 else
4218 {
4219 tree eoc;
4222 /* On some platforms (ARM), even empty classes will not be
4223 byte-aligned. */
4228 /* A nearly-empty class "has no proper base class that is empty,
4229 not morally virtual, and at an offset other than zero." */
4231 {
4234 /* The check above (used in G++ 3.2) is insufficient because
4235 an empty class placed at offset zero might itself have an
4236 empty base at a nonzero offset. */
4238 empty_base_at_nonzero_offset_p,
4239 size_zero_node,
4243 {
4246 else
4248 "class %qT will be considered nearly empty in a "
4250 }
4251 }
4253 /* We do not create a FIELD_DECL for empty base classes because
4254 it might overlap some other field. We want to be able to
4255 create CONSTRUCTORs for the class by iterating over the
4256 FIELD_DECLs, and the back end does not handle overlapping
4257 FIELD_DECLs. */
4259 /* An empty virtual base causes a class to be non-empty
4260 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4261 here because that was already done when the virtual table
4262 pointer was created. */
4263 }
4265 /* Record the offsets of BINFO and its base subobjects. */
4268 offsets,
4272 }
4274 /* Layout all of the non-virtual base classes. Record empty
4275 subobjects in OFFSETS. T is the most derived type. Return nonzero
4276 if the type cannot be nearly empty. The fields created
4277 corresponding to the base classes will be inserted at
4278 *NEXT_FIELD. */
4280 static void
4283 {
4284 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4285 subobjects. */
4290 /* The primary base class is always allocated first. */
4295 /* Now allocate the rest of the bases. */
4297 {
4298 tree base_binfo;
4302 /* The primary base was already allocated above, so we don't
4303 need to allocate it again here. */
4307 /* Virtual bases are added at the end (a primary virtual base
4308 will have already been added). */
4314 }
4315 }
4317 /* Go through the TYPE_METHODS of T issuing any appropriate
4318 diagnostics, figuring out which methods override which other
4319 methods, and so forth. */
4321 static void
4323 {
4324 tree x;
4327 {
4331 /* The name of the field is the original field name
4332 Save this in auxiliary field for later overloading. */
4334 {
4338 }
4339 /* All user-provided destructors are non-trivial.
4340 Constructors and assignment ops are handled in
4341 grok_special_member_properties. */
4344 }
4345 }
4347 /* FN is a constructor or destructor. Clone the declaration to create
4348 a specialized in-charge or not-in-charge version, as indicated by
4349 NAME. */
4351 static tree
4353 {
4354 tree parms;
4355 tree clone;
4357 /* Copy the function. */
4359 /* Reset the function name. */
4362 /* Remember where this function came from. */
4364 /* Make it easy to find the CLONE given the FN. */
4368 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4370 {
4377 }
4380 /* There's no pending inline data for this function. */
4384 /* The base-class destructor is not virtual. */
4386 {
4390 }
4392 /* If there was an in-charge parameter, drop it from the function
4393 type. */
4395 {
4396 tree basetype;
4397 tree parmtypes;
4398 tree exceptions;
4403 /* Skip the `this' parameter. */
4405 /* Skip the in-charge parameter. */
4407 /* And the VTT parm, in a complete [cd]tor. */
4411 /* If this is subobject constructor or destructor, add the vtt
4412 parameter. */
4416 parmtypes);
4419 exceptions);
4423 }
4425 /* Copy the function parameters. */
4427 /* Remove the in-charge parameter. */
4429 {
4433 }
4434 /* And the VTT parm, in a complete [cd]tor. */
4436 {
4439 else
4440 {
4444 }
4445 }
4448 {
4451 }
4453 /* Create the RTL for this function. */
4461 }
4463 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4464 not invoke this function directly.
4466 For a non-thunk function, returns the address of the slot for storing
4467 the function it is a clone of. Otherwise returns NULL_TREE.
4469 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4470 cloned_function is unset. This is to support the separate
4471 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4472 on a template makes sense, but not the former. */
4474 tree *
4476 {
4484 {
4485 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4488 else
4489 #endif
4491 }
4496 else
4498 }
4500 /* Produce declarations for all appropriate clones of FN. If
4501 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4502 CLASTYPE_METHOD_VEC as well. */
4504 void
4506 {
4507 tree clone;
4509 /* Avoid inappropriate cloning. */
4515 {
4516 /* For each constructor, we need two variants: an in-charge version
4517 and a not-in-charge version. */
4524 }
4525 else
4526 {
4529 /* For each destructor, we need three variants: an in-charge
4530 version, a not-in-charge version, and an in-charge deleting
4531 version. We clone the deleting version first because that
4532 means it will go second on the TYPE_METHODS list -- and that
4533 corresponds to the correct layout order in the virtual
4534 function table.
4536 For a non-virtual destructor, we do not build a deleting
4537 destructor. */
4539 {
4543 }
4550 }
4552 /* Note that this is an abstract function that is never emitted. */
4554 }
4556 /* DECL is an in charge constructor, which is being defined. This will
4557 have had an in class declaration, from whence clones were
4558 declared. An out-of-class definition can specify additional default
4559 arguments. As it is the clones that are involved in overload
4560 resolution, we must propagate the information from the DECL to its
4561 clones. */
4563 void
4565 {
4566 tree clone;
4570 {
4577 /* Skip the 'this' parameter. */
4593 {
4598 {
4599 /* A default parameter has been added. Adjust the
4600 clone's parameters. */
4604 tree type;
4609 {
4612 clone_parms);
4614 }
4617 clone_parms);
4626 }
4627 }
4629 }
4630 }
4632 /* For each of the constructors and destructors in T, create an
4633 in-charge and not-in-charge variant. */
4635 static void
4637 {
4638 tree fns;
4640 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4641 out now. */
4649 }
4651 /* Deduce noexcept for a destructor DTOR. */
4653 void
4655 {
4657 {
4664 }
4665 }
4667 /* For each destructor in T, deduce noexcept:
4669 12.4/3: A declaration of a destructor that does not have an
4670 exception-specification is implicitly considered to have the
4671 same exception-specification as an implicit declaration (15.4). */
4673 static void
4675 {
4676 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4677 out now. */
4683 }
4685 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4686 of TYPE for virtual functions which FNDECL overrides. Return a
4687 mask of the tm attributes found therein. */
4689 static int
4691 {
4693 tree base_binfo;
4697 {
4707 else
4709 }
4712 }
4714 /* Subroutine of set_method_tm_attributes. Handle the checks and
4715 inheritance for one virtual method FNDECL. */
4717 static void
4719 {
4720 tree tm_attr;
4725 /* If FNDECL doesn't actually override anything (i.e. T is the
4726 class that first declares FNDECL virtual), then we're done. */
4733 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4734 tm_pure must match exactly, otherwise no weakening of
4735 tm_safe > tm_callable > nothing. */
4736 /* ??? The tm_pure attribute didn't make the transition to the
4737 multivendor language spec. */
4739 {
4741 {
4744 }
4745 }
4746 /* If the overridden function is tm_pure, then FNDECL must be. */
4749 /* Look for base class combinations that cannot be satisfied. */
4751 {
4757 }
4758 /* If FNDECL did not declare an attribute, then inherit the most
4759 restrictive one. */
4761 {
4763 }
4764 /* Otherwise validate that we're not weaker than a function
4765 that is being overridden. */
4766 else
4767 {
4771 }
4774 err_override:
4778 }
4780 /* For each of the methods in T, propagate a class-level tm attribute. */
4782 static void
4784 {
4787 /* Don't bother collecting tm attributes if transactional memory
4788 support is not enabled. */
4792 /* Process virtual methods first, as they inherit directly from the
4793 base virtual function and also require validation of new attributes. */
4795 {
4796 tree vchain;
4799 {
4804 }
4805 }
4807 /* If the class doesn't have an attribute, nothing more to do. */
4812 /* Any method that does not yet have a tm attribute inherits
4813 the one from the class. */
4815 {
4818 }
4819 }
4821 /* Returns true iff class T has a user-defined constructor other than
4822 the default constructor. */
4824 bool
4826 {
4827 tree fns;
4833 {
4840 }
4843 }
4845 /* Returns the defaulted constructor if T has one. Otherwise, returns
4846 NULL_TREE. */
4848 tree
4850 {
4857 {
4861 {
4867 }
4868 }
4871 }
4873 /* Returns true iff FN is a user-provided function, i.e. user-declared
4874 and not defaulted at its first declaration; or explicit, private,
4875 protected, or non-const. */
4877 bool
4879 {
4882 else
4886 }
4888 /* Returns true iff class T has a user-provided constructor. */
4890 bool
4892 {
4893 tree fns;
4901 /* This can happen in error cases; avoid crashing. */
4910 }
4912 /* Returns true iff class T has a user-provided default constructor. */
4914 bool
4916 {
4917 tree fns;
4923 {
4929 }
4932 }
4934 /* TYPE is being used as a virtual base, and has a non-trivial move
4935 assignment. Return true if this is due to there being a user-provided
4936 move assignment in TYPE or one of its subobjects; if there isn't, then
4937 multiple move assignment can't cause any harm. */
4939 bool
4941 {
4942 /* Does the type itself have a user-provided move assignment operator? */
4946 {
4950 }
4952 /* Do any of its bases? */
4954 tree base_binfo;
4959 /* Or non-static data members? */
4961 {
4966 }
4968 /* Seems not. */
4970 }
4972 /* If default-initialization leaves part of TYPE uninitialized, returns
4973 a DECL for the field or TYPE itself (DR 253). */
4975 tree
4977 {
4988 {
4992 }
4997 {
5001 }
5004 }
5006 /* Returns true iff for class T, a trivial synthesized default constructor
5007 would be constexpr. */
5009 bool
5011 {
5012 /* A defaulted trivial default constructor is constexpr
5013 if there is nothing to initialize. */
5016 }
5018 /* Returns true iff class T has a constexpr default constructor. */
5020 bool
5022 {
5023 tree fns;
5026 {
5027 /* The caller should have stripped an enclosing array. */
5030 }
5032 {
5035 /* Non-trivial, we need to check subobject constructors. */
5037 }
5040 }
5042 /* Returns true iff class TYPE has a virtual destructor. */
5044 bool
5046 {
5047 tree dtor;
5055 }
5057 /* Returns true iff class T has a move constructor. */
5059 bool
5061 {
5062 tree fns;
5065 {
5068 }
5078 }
5080 /* Returns true iff class T has a move assignment operator. */
5082 bool
5084 {
5085 tree fns;
5088 {
5091 }
5099 }
5101 /* Returns true iff class T has a move constructor that was explicitly
5102 declared in the class body. Note that this is different from
5103 "user-provided", which doesn't include functions that are defaulted in
5104 the class. */
5106 bool
5108 {
5109 tree fns;
5118 {
5122 }
5125 }
5127 /* Returns true iff class T has a move assignment operator that was
5128 explicitly declared in the class body. */
5130 bool
5132 {
5133 tree fns;
5140 {
5144 }
5147 }
5149 /* Nonzero if we need to build up a constructor call when initializing an
5150 object of this class, either because it has a user-declared constructor
5151 or because it doesn't have a default constructor (so we need to give an
5152 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5153 what you care about is whether or not an object can be produced by a
5154 constructor (e.g. so we don't set TREE_READONLY on const variables of
5155 such type); use this function when what you care about is whether or not
5156 to try to call a constructor to create an object. The latter case is
5157 the former plus some cases of constructors that cannot be called. */
5159 bool
5161 {
5162 tree inner;
5172 /* A user-declared constructor might be private, and a constructor might
5173 be trivial but deleted. */
5176 {
5181 }
5183 }
5185 /* Like type_build_ctor_call, but for destructors. */
5187 bool
5189 {
5190 tree inner;
5199 /* A user-declared destructor might be private, and a destructor might
5200 be trivial but deleted. */
5203 {
5208 }
5210 }
5212 /* Remove all zero-width bit-fields from T. */
5214 static void
5216 {
5221 {
5224 /* We should not be confused by the fact that grokbitfield
5225 temporarily sets the width of the bit field into
5226 DECL_INITIAL (*fieldsp).
5227 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5228 to that width. */
5231 else
5233 }
5234 }
5236 /* Returns TRUE iff we need a cookie when dynamically allocating an
5237 array whose elements have the indicated class TYPE. */
5239 static bool
5241 {
5242 tree fns;
5247 /* If there's a non-trivial destructor, we need a cookie. In order
5248 to iterate through the array calling the destructor for each
5249 element, we'll have to know how many elements there are. */
5253 /* If the usual deallocation function is a two-argument whose second
5254 argument is of type `size_t', then we have to pass the size of
5255 the array to the deallocation function, so we will need to store
5256 a cookie. */
5260 /* If there are no `operator []' members, or the lookup is
5261 ambiguous, then we don't need a cookie. */
5264 /* Loop through all of the functions. */
5266 {
5267 tree fn;
5268 tree second_parm;
5270 /* Select the current function. */
5272 /* See if this function is a one-argument delete function. If
5273 it is, then it will be the usual deallocation function. */
5277 /* Do not consider this function if its second argument is an
5278 ellipsis. */
5281 /* Otherwise, if we have a two-argument function and the second
5282 argument is `size_t', it will be the usual deallocation
5283 function -- unless there is one-argument function, too. */
5287 }
5290 }
5292 /* Finish computing the `literal type' property of class type T.
5294 At this point, we have already processed base classes and
5295 non-static data members. We need to check whether the copy
5296 constructor is trivial, the destructor is trivial, and there
5297 is a trivial default constructor or at least one constexpr
5298 constructor other than the copy constructor. */
5300 static void
5302 {
5303 tree fn;
5319 {
5322 {
5326 }
5327 }
5328 }
5330 /* T is a non-literal type used in a context which requires a constant
5331 expression. Explain why it isn't literal. */
5333 void
5335 {
5345 /* Already explained. */
5354 {
5356 "default constructor, and has no constexpr constructor that "
5360 {
5361 /* Note that we can't simply call locate_ctor because when the
5362 constructor is deleted it just returns NULL_TREE. */
5363 tree fns;
5365 {
5372 {
5375 else
5378 }
5379 }
5380 }
5381 }
5382 else
5383 {
5387 {
5390 {
5395 }
5396 }
5398 {
5399 tree ftype;
5404 {
5409 }
5410 }
5411 }
5412 }
5414 /* Check the validity of the bases and members declared in T. Add any
5415 implicitly-generated functions (like copy-constructors and
5416 assignment operators). Compute various flag bits (like
5417 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5418 level: i.e., independently of the ABI in use. */
5420 static void
5422 {
5423 /* Nonzero if the implicitly generated copy constructor should take
5424 a non-const reference argument. */
5426 /* Nonzero if the implicitly generated assignment operator
5427 should take a non-const reference argument. */
5429 tree access_decls;
5432 tree fn;
5434 /* By default, we use const reference arguments and generate default
5435 constructors. */
5439 /* Check all the base-classes. */
5443 /* Deduce noexcept on destructors. This needs to happen after we've set
5444 triviality flags appropriately for our bases. */
5448 /* Check all the method declarations. */
5451 /* Save the initial values of these flags which only indicate whether
5452 or not the class has user-provided functions. As we analyze the
5453 bases and members we can set these flags for other reasons. */
5457 /* Check all the data member declarations. We cannot call
5458 check_field_decls until we have called check_bases check_methods,
5459 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5460 being set appropriately. */
5465 /* A nearly-empty class has to be vptr-containing; a nearly empty
5466 class contains just a vptr. */
5470 /* Do some bookkeeping that will guide the generation of implicitly
5471 declared member functions. */
5474 /* We need to call a constructor for this class if it has a
5475 user-provided constructor, or if the default constructor is going
5476 to initialize the vptr. (This is not an if-and-only-if;
5477 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5478 themselves need constructing.) */
5481 /* [dcl.init.aggr]
5483 An aggregate is an array or a class with no user-provided
5484 constructors ... and no virtual functions.
5486 Again, other conditions for being an aggregate are checked
5487 elsewhere. */
5490 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5491 retain the old definition internally for ABI reasons. */
5500 /* If the class has no user-declared constructor, but does have
5501 non-static const or reference data members that can never be
5502 initialized, issue a warning. */
5504 /* Classes with user-declared constructors are presumed to
5505 initialize these members. */
5507 /* Aggregates can be initialized with brace-enclosed
5508 initializers. */
5510 {
5511 tree field;
5514 {
5515 tree type;
5530 }
5531 }
5533 /* Synthesize any needed methods. */
5535 cant_have_const_ctor,
5536 no_const_asn_ref);
5538 /* Check defaulted declarations here so we have cant_have_const_ctor
5539 and don't need to worry about clones. */
5542 {
5545 {
5546 bool imp_const_p
5552 /* If the function is defaulted outside the class, we just
5553 give the synthesis error. */
5556 }
5558 }
5561 {
5562 /* "The closure type associated with a lambda-expression has a deleted
5563 default constructor and a deleted copy assignment operator." */
5569 /* "This class type is not an aggregate." */
5571 }
5573 /* Compute the 'literal type' property before we
5574 do anything with non-static member functions. */
5577 /* Create the in-charge and not-in-charge variants of constructors
5578 and destructors. */
5581 /* Process the using-declarations. */
5585 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5588 /* Figure out whether or not we will need a cookie when dynamically
5589 allocating an array of this type. */
5592 }
5594 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5595 accordingly. If a new vfield was created (because T doesn't have a
5596 primary base class), then the newly created field is returned. It
5597 is not added to the TYPE_FIELDS list; it is the caller's
5598 responsibility to do that. Accumulate declared virtual functions
5599 on VIRTUALS_P. */
5601 static tree
5603 {
5604 tree fn;
5606 /* Collect the virtual functions declared in T. */
5610 {
5619 }
5621 /* If we couldn't find an appropriate base class, create a new field
5622 here. Even if there weren't any new virtual functions, we might need a
5623 new virtual function table if we're supposed to include vptrs in
5624 all classes that need them. */
5626 {
5627 /* We build this decl with vtbl_ptr_type_node, which is a
5628 `vtable_entry_type*'. It might seem more precise to use
5629 `vtable_entry_type (*)[N]' where N is the number of virtual
5630 functions. However, that would require the vtable pointer in
5631 base classes to have a different type than the vtable pointer
5632 in derived classes. We could make that happen, but that
5633 still wouldn't solve all the problems. In particular, the
5634 type-based alias analysis code would decide that assignments
5635 to the base class vtable pointer can't alias assignments to
5636 the derived class vtable pointer, since they have different
5637 types. Thus, in a derived class destructor, where the base
5638 class constructor was inlined, we could generate bad code for
5639 setting up the vtable pointer.
5641 Therefore, we use one type for all vtable pointers. We still
5642 use a type-correct type; it's just doesn't indicate the array
5643 bounds. That's better than using `void*' or some such; it's
5644 cleaner, and it let's the alias analysis code know that these
5645 stores cannot alias stores to void*! */
5646 tree field;
5659 /* This class is non-empty. */
5663 }
5666 }
5668 /* Add OFFSET to all base types of BINFO which is a base in the
5669 hierarchy dominated by T.
5671 OFFSET, which is a type offset, is number of bytes. */
5673 static void
5675 {
5677 tree primary_binfo;
5678 tree base_binfo;
5680 /* Update BINFO's offset. */
5685 offset));
5687 /* Find the primary base class. */
5693 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5694 downwards. */
5696 {
5697 /* Don't do the primary base twice. */
5705 }
5706 }
5708 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5709 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5710 empty subobjects of T. */
5712 static void
5714 {
5715 tree vbase;
5724 {
5725 /* In G++ 3.2, we incorrectly rounded the size before laying out
5726 the virtual bases. */
5728 #ifdef STRUCTURE_SIZE_BOUNDARY
5729 /* Packed structures don't need to have minimum size. */
5732 #endif
5736 }
5738 /* Find the last field. The artificial fields created for virtual
5739 bases will go after the last extant field to date. */
5744 /* Go through the virtual bases, allocating space for each virtual
5745 base that is not already a primary base class. These are
5746 allocated in inheritance graph order. */
5748 {
5753 {
5756 /* This virtual base is not a primary base of any class in the
5757 hierarchy, so we have to add space for it. */
5761 /* If the first virtual base might have been placed at a
5762 lower address, had we started from CLASSTYPE_SIZE, rather
5763 than TYPE_SIZE, issue a warning. There can be both false
5764 positives and false negatives from this warning in rare
5765 cases; to deal with all the possibilities would probably
5766 require performing both layout algorithms and comparing
5767 the results which is not particularly tractable. */
5769 && first_vbase
5770 && (tree_int_cst_lt
5775 bitsize_unit_node),
5778 "offset of virtual base %qT is not ABI-compliant and "
5780 basetype);
5783 }
5784 }
5785 }
5787 /* Returns the offset of the byte just past the end of the base class
5788 BINFO. */
5790 static tree
5792 {
5793 tree size;
5798 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5799 allocate some space for it. It cannot have virtual bases, so
5800 TYPE_SIZE_UNIT is fine. */
5802 else
5806 }
5808 /* Returns the offset of the byte just past the end of the base class
5809 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5810 only non-virtual bases are included. */
5812 static tree
5814 {
5817 tree binfo;
5818 tree base_binfo;
5819 tree offset;
5824 {
5834 }
5836 /* G++ 3.2 did not check indirect virtual bases. */
5840 {
5844 }
5847 }
5849 /* Warn about bases of T that are inaccessible because they are
5850 ambiguous. For example:
5852 struct S {};
5853 struct T : public S {};
5854 struct U : public S, public T {};
5856 Here, `(S*) new U' is not allowed because there are two `S'
5857 subobjects of U. */
5859 static void
5861 {
5864 tree basetype;
5865 tree binfo;
5866 tree base_binfo;
5868 /* If there are no repeated bases, nothing can be ambiguous. */
5872 /* Check direct bases. */
5875 {
5881 }
5883 /* Check for ambiguous virtual bases. */
5887 {
5893 }
5894 }
5896 /* Compare two INTEGER_CSTs K1 and K2. */
5898 static int
5900 {
5902 }
5904 /* Increase the size indicated in RLI to account for empty classes
5905 that are "off the end" of the class. */
5907 static void
5909 {
5910 tree eoc;
5911 tree rli_size;
5913 /* It might be the case that we grew the class to allocate a
5914 zero-sized base class. That won't be reflected in RLI, yet,
5915 because we are willing to overlay multiple bases at the same
5916 offset. However, now we need to make sure that RLI is big enough
5917 to reflect the entire class. */
5923 {
5925 /* In version 1 of the ABI, the size of a class that ends with
5926 a bitfield was not rounded up to a whole multiple of a
5927 byte. Because rli_size_unit_so_far returns only the number
5928 of fully allocated bytes, any extra bits were not included
5929 in the size. */
5931 else
5932 /* The size should have been rounded to a whole byte. */
5935 rli->bitpos
5944 }
5945 }
5947 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5948 BINFO_OFFSETs for all of the base-classes. Position the vtable
5949 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5951 static void
5953 {
5954 tree non_static_data_members;
5955 tree field;
5956 tree vptr;
5957 record_layout_info rli;
5958 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5959 types that appear at that offset. */
5960 splay_tree empty_base_offsets;
5961 /* True if the last field laid out was a bit-field. */
5963 /* The location at which the next field should be inserted. */
5965 /* T, as a base class. */
5966 tree base_t;
5968 /* Keep track of the first non-static data member. */
5971 /* Start laying out the record. */
5974 /* Mark all the primary bases in the hierarchy. */
5977 /* Create a pointer to our virtual function table. */
5980 /* The vptr is always the first thing in the class. */
5982 {
5987 }
5988 else
5991 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5996 /* Layout the non-static data members. */
5998 {
5999 tree type;
6000 tree padding;
6002 /* We still pass things that aren't non-static data members to
6003 the back end, in case it wants to do something with them. */
6005 {
6007 /* If the static data member has incomplete type, keep track
6008 of it so that it can be completed later. (The handling
6009 of pending statics in finish_record_layout is
6010 insufficient; consider:
6012 struct S1;
6013 struct S2 { static S1 s1; };
6015 At this point, finish_record_layout will be called, but
6016 S1 is still incomplete.) */
6018 {
6020 /* The visibility of static data members is determined
6021 at their point of declaration, not their point of
6022 definition. */
6024 }
6026 }
6034 /* If this field is a bit-field whose width is greater than its
6035 type, then there are some special rules for allocating
6036 it. */
6039 {
6041 tree integer_type;
6043 /* We must allocate the bits as if suitably aligned for the
6044 longest integer type that fits in this many bits. type
6045 of the field. Then, we are supposed to use the left over
6046 bits as additional padding. */
6055 /* ITK now indicates a type that is too large for the
6056 field. We have to back up by one to find the largest
6057 type that fits. */
6058 do
6059 {
6064 /* Figure out how much additional padding is required. GCC
6065 3.2 always created a padding field, even if it had zero
6066 width. */
6069 {
6071 /* In a union, the padding field must have the full width
6072 of the bit-field; all fields start at offset zero. */
6074 else
6075 {
6078 "ABI-compliant and may change in a future "
6080 t);
6083 }
6084 }
6085 #ifdef PCC_BITFIELD_TYPE_MATTERS
6086 /* An unnamed bitfield does not normally affect the
6087 alignment of the containing class on a target where
6088 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6089 make any exceptions for unnamed bitfields when the
6090 bitfields are longer than their types. Therefore, we
6091 temporarily give the field a name. */
6093 {
6096 }
6097 #endif
6102 empty_base_offsets);
6105 /* Now that layout has been performed, set the size of the
6106 field to the size of its declared type; the rest of the
6107 field is effectively invisible. */
6109 /* We must also reset the DECL_MODE of the field. */
6114 /* Versions of G++ before G++ 3.4 did not reset the
6115 DECL_MODE. */
6117 "the offset of %qD may not be ABI-compliant and may "
6119 }
6120 else
6122 empty_base_offsets);
6124 /* Remember the location of any empty classes in FIELD. */
6128 empty_base_offsets,
6131 /* If a bit-field does not immediately follow another bit-field,
6132 and yet it starts in the middle of a byte, we have failed to
6133 comply with the ABI. */
6136 /* The TREE_NO_WARNING flag gets set by Objective-C when
6137 laying out an Objective-C class. The ObjC ABI differs
6138 from the C++ ABI, and so we do not want a warning
6139 here. */
6141 && !last_field_was_bitfield
6144 bitsize_unit_node)))
6148 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6149 offset of the field. */
6156 "classes to be placed at different locations in a "
6159 /* The middle end uses the type of expressions to determine the
6160 possible range of expression values. In order to optimize
6161 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6162 must be made aware of the width of "i", via its type.
6164 Because C++ does not have integer types of arbitrary width,
6165 we must (for the purposes of the front end) convert from the
6166 type assigned here to the declared type of the bitfield
6167 whenever a bitfield expression is used as an rvalue.
6168 Similarly, when assigning a value to a bitfield, the value
6169 must be converted to the type given the bitfield here. */
6171 {
6176 {
6183 }
6184 }
6186 /* If we needed additional padding after this field, add it
6187 now. */
6189 {
6190 tree padding_field;
6193 FIELD_DECL,
6194 NULL_TREE,
6195 char_type_node);
6202 NULL_TREE,
6203 empty_base_offsets);
6204 }
6207 }
6210 {
6211 /* Make sure that we are on a byte boundary so that the size of
6212 the class without virtual bases will always be a round number
6213 of bytes. */
6216 }
6218 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6219 padding. */
6223 /* Delete all zero-width bit-fields from the list of fields. Now
6224 that the type is laid out they are no longer important. */
6227 /* Create the version of T used for virtual bases. We do not use
6228 make_class_type for this version; this is an artificial type. For
6229 a POD type, we just reuse T. */
6231 {
6234 /* Set the size and alignment for the new type. In G++ 3.2, all
6235 empty classes were considered to have size zero when used as
6236 base classes. */
6238 {
6243 "layout of classes derived from empty class %qT "
6245 t);
6246 }
6247 else
6248 {
6249 tree eoc;
6251 /* If the ABI version is not at least two, and the last
6252 field was a bit-field, RLI may not be on a byte
6253 boundary. In particular, rli_size_unit_so_far might
6254 indicate the last complete byte, while rli_size_so_far
6255 indicates the total number of bits used. Therefore,
6256 rli_size_so_far, rather than rli_size_unit_so_far, is
6257 used to compute TYPE_SIZE_UNIT. */
6265 eoc);
6272 }
6276 /* Copy the fields from T. */
6280 {
6282 FIELD_DECL,
6292 }
6294 /* Record the base version of the type. */
6297 }
6298 else
6301 /* Every empty class contains an empty class. */
6305 /* Set the TYPE_DECL for this type to contain the right
6306 value for DECL_OFFSET, so that we can use it as part
6307 of a COMPONENT_REF for multiple inheritance. */
6310 /* Now fix up any virtual base class types that we left lying
6311 around. We must get these done before we try to lay out the
6312 virtual function table. As a side-effect, this will remove the
6313 base subobject fields. */
6316 /* Make sure that empty classes are reflected in RLI at this
6317 point. */
6320 /* Make sure not to create any structures with zero size. */
6326 /* If this is a non-POD, declaring it packed makes a difference to how it
6327 can be used as a field; don't let finalize_record_size undo it. */
6331 /* Let the back end lay out the type. */
6340 /* Warn about bases that can't be talked about due to ambiguity. */
6343 /* Now that we're done with layout, give the base fields the real types. */
6348 /* Clean up. */
6355 }
6357 /* Determine the "key method" for the class type indicated by TYPE,
6358 and set CLASSTYPE_KEY_METHOD accordingly. */
6360 void
6362 {
6363 tree method;
6366 || processing_template_decl
6371 /* The key method is the first non-pure virtual function that is not
6372 inline at the point of class definition. On some targets the
6373 key function may not be inline; those targets should not call
6374 this function until the end of the translation unit. */
6380 {
6383 }
6386 }
6389 /* Allocate and return an instance of struct sorted_fields_type with
6390 N fields. */
6394 {
6401 }
6404 /* Perform processing required when the definition of T (a class type)
6405 is complete. */
6407 void
6409 {
6410 tree x;
6411 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6415 {
6420 }
6422 /* If this type was previously laid out as a forward reference,
6423 make sure we lay it out again. */
6427 /* Make assumptions about the class; we'll reset the flags if
6428 necessary. */
6434 /* Do end-of-class semantic processing: checking the validity of the
6435 bases and members and add implicitly generated methods. */
6438 /* Find the key method. */
6440 {
6441 /* The Itanium C++ ABI permits the key method to be chosen when
6442 the class is defined -- even though the key method so
6443 selected may later turn out to be an inline function. On
6444 some systems (such as ARM Symbian OS) the key method cannot
6445 be determined until the end of the translation unit. On such
6446 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6447 will cause the class to be added to KEYED_CLASSES. Then, in
6448 finish_file we will determine the key method. */
6452 /* If a polymorphic class has no key method, we may emit the vtable
6453 in every translation unit where the class definition appears. */
6456 }
6458 /* Layout the class itself. */
6461 /* We use the base type for trivial assignments, and hence it
6462 needs a mode. */
6467 /* If necessary, create the primary vtable for this class. */
6469 {
6470 /* We must enter these virtuals into the table. */
6474 /* Here we know enough to change the type of our virtual
6475 function table, but we will wait until later this function. */
6478 /* If we're warning about ABI tags, check the types of the new
6479 virtual functions. */
6483 }
6486 {
6488 tree fn;
6495 /* Add entries for virtual functions introduced by this class. */
6499 /* Set DECL_VINDEX for all functions declared in this class. */
6501 fn;
6503 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6505 {
6509 /* A thunk. We should never be calling this entry directly
6510 from this vtable -- we'd use the entry for the non
6511 thunk base function. */
6515 }
6516 }
6521 /* Complete the rtl for any static member objects of the type we're
6522 working on. */
6529 /* Done with FIELDS...now decide whether to sort these for
6530 faster lookups later.
6532 We use a small number because most searches fail (succeeding
6533 ultimately as the search bores through the inheritance
6534 hierarchy), and we want this failure to occur quickly. */
6538 /* Complain if one of the field types requires lower visibility. */
6541 /* Make the rtl for any new vtables we have created, and unmark
6542 the base types we marked. */
6545 /* Build the VTT for T. */
6548 /* This warning does not make sense for Java classes, since they
6549 cannot have destructors. */
6551 {
6552 tree dtor;
6556 if it were virtual, we would have created it by now. */
6557 !dtor
6566 "%q#T has virtual functions and accessible"
6568 }
6575 /* Class layout, assignment of virtual table slots, etc., is now
6576 complete. Give the back end a chance to tweak the visibility of
6577 the class or perform any other required target modifications. */
6587 /* Finish debugging output for this type. */
6591 {
6594 {
6597 }
6599 {
6602 else
6603 {
6606 }
6608 }
6610 {
6612 "the type of the first field has a different ABI from the "
6615 }
6616 }
6617 }
6619 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6620 equal to THRESHOLD or greater than THRESHOLD. */
6622 static void
6624 {
6627 {
6632 }
6633 }
6635 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6637 void
6639 {
6642 {
6644 int n_fields
6655 }
6656 }
6658 /* When T was built up, the member declarations were added in reverse
6659 order. Rearrange them to declaration order. */
6661 void
6663 {
6664 tree next;
6665 tree prev;
6666 tree x;
6668 /* The following lists are all in reverse order. Put them in
6669 declaration order now. */
6673 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6674 reverse order, so we can't just use nreverse. */
6679 {
6683 }
6685 {
6689 }
6690 }
6692 tree
6694 {
6697 /* Now that we've got all the field declarations, reverse everything
6698 as necessary. */
6703 /* Nadger the current location so that diagnostics point to the start of
6704 the struct, not the end. */
6708 {
6709 tree x;
6715 /* We need to emit an error message if this type was used as a parameter
6716 and it is an abstract type, even if it is a template. We construct
6717 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6718 account and we call complete_vars with this type, which will check
6719 the PARM_DECLS. Note that while the type is being defined,
6720 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6721 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6727 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6728 an enclosing scope is a template class, so that this function be
6729 found by lookup_fnfields_1 when the using declaration is not
6730 instantiated yet. */
6733 {
6738 }
6740 /* Remember current #pragma pack value. */
6743 /* Fix up any variants we've already built. */
6745 {
6750 }
6751 }
6752 else
6761 else
6765 /* Lambdas are defined by the LAMBDA_EXPR. */
6770 }
6771 \f
6772 /* Hash table to avoid endless recursion when handling references. */
6775 /* Return the dynamic type of INSTANCE, if known.
6776 Used to determine whether the virtual function table is needed
6777 or not.
6779 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6780 of our knowledge of its type. *NONNULL should be initialized
6781 before this function is called. */
6783 static tree
6785 {
6786 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6789 {
6793 else
6797 /* This is a call to a constructor, hence it's never zero. */
6799 {
6803 }
6807 /* This is a call to a constructor, hence it's never zero. */
6809 {
6813 }
6822 /* Propagate nonnull. */
6827 CASE_CONVERT:
6833 {
6834 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6835 with a real object -- given &p->f, p can still be null. */
6837 /* ??? Probably should check DECL_WEAK here. */
6840 }
6844 /* If this component is really a base class reference, then the field
6845 itself isn't definitive. */
6854 {
6858 }
6859 /* fall through... */
6864 {
6868 }
6870 {
6874 /* if we're in a ctor or dtor, we know our type. If
6875 current_class_ptr is set but we aren't in a function, we're in
6876 an NSDMI (and therefore a constructor). */
6881 {
6885 }
6886 }
6888 {
6889 /* We only need one hash table because it is always left empty. */
6893 /* Reference variables should be references to objects. */
6897 /* Enter the INSTANCE in a table to prevent recursion; a
6898 variable's initializer may refer to the variable
6899 itself. */
6904 {
6905 tree type;
6914 }
6915 }
6920 }
6921 #undef RECUR
6922 }
6924 /* Return nonzero if the dynamic type of INSTANCE is known, and
6925 equivalent to the static type. We also handle the case where
6926 INSTANCE is really a pointer. Return negative if this is a
6927 ctor/dtor. There the dynamic type is known, but this might not be
6928 the most derived base of the original object, and hence virtual
6929 bases may not be laid out according to this type.
6931 Used to determine whether the virtual function table is needed
6932 or not.
6934 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6935 of our knowledge of its type. *NONNULL should be initialized
6936 before this function is called. */
6938 int
6940 {
6943 tree fixed;
6945 /* processing_template_decl can be false in a template if we're in
6946 fold_non_dependent_expr, but we still want to suppress this check. */
6948 {
6949 /* In a template we only care about the type of the result. */
6953 }
6963 }
6965 \f
6966 void
6968 {
6971 current_class_stack
6979 }
6981 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6983 static void
6985 {
6986 tree type;
6988 /* We are re-entering the same class we just left, so we don't
6989 have to search the whole inheritance matrix to find all the
6990 decls to bind again. Instead, we install the cached
6991 class_shadowed list and walk through it binding names. */
6994 /* Restore IDENTIFIER_TYPE_VALUE. */
6996 type;
6999 }
7001 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7002 appropriate for TYPE.
7004 So that we may avoid calls to lookup_name, we cache the _TYPE
7005 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7007 For multiple inheritance, we perform a two-pass depth-first search
7008 of the type lattice. */
7010 void
7012 {
7013 class_stack_node_t csn;
7017 /* Make sure there is enough room for the new entry on the stack. */
7019 {
7021 current_class_stack
7023 current_class_stack_size);
7024 }
7026 /* Insert a new entry on the class stack. */
7033 current_class_depth++;
7035 /* Now set up the new type. */
7041 /* By default, things in classes are private, while things in
7042 structures or unions are public. */
7044 ? access_private_node
7050 {
7051 /* Forcibly remove any old class remnants. */
7053 }
7059 else
7061 }
7063 /* When we exit a toplevel class scope, we save its binding level so
7064 that we can restore it quickly. Here, we've entered some other
7065 class, so we must invalidate our cache. */
7067 void
7069 {
7071 }
7073 /* Get out of the current class scope. If we were in a class scope
7074 previously, that is the one popped to. */
7076 void
7078 {
7081 current_class_depth--;
7087 }
7089 /* Mark the top of the class stack as hidden. */
7091 void
7093 {
7096 }
7098 /* Mark the top of the class stack as un-hidden. */
7100 void
7102 {
7105 }
7107 /* Returns 1 if the class type currently being defined is either T or
7108 a nested type of T. */
7110 bool
7112 {
7120 /* We start looking from 1 because entry 0 is from global scope,
7121 and has no type. */
7123 {
7124 tree c;
7127 else
7128 {
7132 }
7137 }
7139 }
7141 /* If either current_class_type or one of its enclosing classes are derived
7142 from T, return the appropriate type. Used to determine how we found
7143 something via unqualified lookup. */
7145 tree
7147 {
7150 /* The bases of a dependent type are unknown. */
7161 {
7166 }
7169 }
7171 /* Returns the innermost class type which is not a lambda closure type. */
7173 tree
7175 {
7178 /* We start looking from 1 because entry 0 is from global scope,
7179 and has no type. */
7181 {
7182 tree c;
7185 else
7186 {
7190 }
7195 }
7197 }
7199 /* When entering a class scope, all enclosing class scopes' names with
7200 static meaning (static variables, static functions, types and
7201 enumerators) have to be visible. This recursive function calls
7202 pushclass for all enclosing class contexts until global or a local
7203 scope is reached. TYPE is the enclosed class. */
7205 void
7207 {
7208 /* A namespace might be passed in error cases, like A::B:C. */
7216 }
7218 /* Undoes a push_nested_class call. */
7220 void
7222 {
7228 }
7230 /* Returns the number of extern "LANG" blocks we are nested within. */
7232 int
7234 {
7236 }
7238 /* Set global variables CURRENT_LANG_NAME to appropriate value
7239 so that behavior of name-mangling machinery is correct. */
7241 void
7243 {
7247 {
7249 }
7251 {
7253 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7254 (See record_builtin_java_type in decl.c.) However, that causes
7255 incorrect debug entries if these types are actually used.
7256 So we re-enable debug output after extern "Java". */
7265 }
7267 {
7269 }
7270 else
7272 }
7274 /* Get out of the current language scope. */
7276 void
7278 {
7280 }
7281 \f
7282 /* Type instantiation routines. */
7284 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7285 matches the TARGET_TYPE. If there is no satisfactory match, return
7286 error_mark_node, and issue an error & warning messages under
7287 control of FLAGS. Permit pointers to member function if FLAGS
7288 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7289 a template-id, and EXPLICIT_TARGS are the explicitly provided
7290 template arguments.
7292 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7293 is the base path used to reference those member functions. If
7294 the address is resolved to a member function, access checks will be
7295 performed and errors issued if appropriate. */
7297 static tree
7299 tree overload,
7300 tsubst_flags_t flags,
7302 tree explicit_targs,
7303 tree access_path)
7304 {
7305 /* Here's what the standard says:
7307 [over.over]
7309 If the name is a function template, template argument deduction
7310 is done, and if the argument deduction succeeds, the deduced
7311 arguments are used to generate a single template function, which
7312 is added to the set of overloaded functions considered.
7314 Non-member functions and static member functions match targets of
7315 type "pointer-to-function" or "reference-to-function." Nonstatic
7316 member functions match targets of type "pointer-to-member
7317 function;" the function type of the pointer to member is used to
7318 select the member function from the set of overloaded member
7319 functions. If a nonstatic member function is selected, the
7320 reference to the overloaded function name is required to have the
7321 form of a pointer to member as described in 5.3.1.
7323 If more than one function is selected, any template functions in
7324 the set are eliminated if the set also contains a non-template
7325 function, and any given template function is eliminated if the
7326 set contains a second template function that is more specialized
7327 than the first according to the partial ordering rules 14.5.5.2.
7328 After such eliminations, if any, there shall remain exactly one
7329 selected function. */
7332 /* We store the matches in a TREE_LIST rooted here. The functions
7333 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7334 interoperability with most_specialized_instantiation. */
7336 tree fn;
7337 tree target_fn_type;
7339 /* By the time we get here, we should be seeing only real
7340 pointer-to-member types, not the internal POINTER_TYPE to
7341 METHOD_TYPE representation. */
7347 /* Check that the TARGET_TYPE is reasonable. */
7352 /* This is OK, too. */
7355 /* This is OK, too. This comes from a conversion to reference
7356 type. */
7358 else
7359 {
7365 }
7367 /* Non-member functions and static member functions match targets of type
7368 "pointer-to-function" or "reference-to-function." Nonstatic member
7369 functions match targets of type "pointer-to-member-function;" the
7370 function type of the pointer to member is used to select the member
7371 function from the set of overloaded member functions.
7373 So figure out the FUNCTION_TYPE that we want to match against. */
7376 /* If we can find a non-template function that matches, we can just
7377 use it. There's no point in generating template instantiations
7378 if we're just going to throw them out anyhow. But, of course, we
7379 can only do this when we don't *need* a template function. */
7381 {
7382 tree fns;
7385 {
7389 /* We're not looking for templates just yet. */
7394 /* We're looking for a non-static member, and this isn't
7395 one, or vice versa. */
7398 /* Ignore functions which haven't been explicitly
7399 declared. */
7403 /* See if there's a match. */
7406 }
7407 }
7409 /* Now, if we've already got a match (or matches), there's no need
7410 to proceed to the template functions. But, if we don't have a
7411 match we need to look at them, too. */
7413 {
7414 tree target_arg_types;
7415 tree target_ret_type;
7416 tree fns;
7419 tree arg;
7433 {
7435 tree instantiation;
7436 tree targs;
7439 /* We're only looking for templates. */
7444 /* We're not looking for a non-static member, and this is
7445 one, or vice versa. */
7450 /* If the template has a deduced return type, don't expose it to
7451 template argument deduction. */
7455 /* Try to do argument deduction. */
7462 /* Instantiation failed. */
7465 /* And now force instantiation to do return type deduction. */
7467 {
7473 }
7475 /* See if there's a match. */
7478 }
7480 /* Now, remove all but the most specialized of the matches. */
7482 {
7487 NULL_TREE,
7488 NULL_TREE);
7489 }
7490 }
7492 /* Now we should have exactly one function in MATCHES. */
7494 {
7495 /* There were *no* matches. */
7497 {
7500 target_type);
7503 }
7505 }
7507 {
7508 /* There were too many matches. First check if they're all
7509 the same function. */
7514 /* For multi-versioned functions, more than one match is just fine and
7515 decls_match will return false as they are different. */
7523 {
7525 {
7528 target_type);
7530 /* Since print_candidates expects the functions in the
7531 TREE_VALUE slot, we flip them here. */
7536 }
7539 }
7540 }
7542 /* Good, exactly one match. Now, convert it to the correct type. */
7547 {
7555 {
7558 }
7559 }
7561 /* If a pointer to a function that is multi-versioned is requested, the
7562 pointer to the dispatcher function is returned instead. This works
7563 well because indirectly calling the function will dispatch the right
7564 function version at run-time. */
7566 {
7570 /* Mark all the versions corresponding to the dispatcher as used. */
7573 }
7575 /* If we're doing overload resolution purely for the purpose of
7576 determining conversion sequences, we should not consider the
7577 function used. If this conversion sequence is selected, the
7578 function will be marked as used at this point. */
7580 {
7581 /* Make =delete work with SFINAE. */
7586 }
7588 /* We could not check access to member functions when this
7589 expression was originally created since we did not know at that
7590 time to which function the expression referred. */
7592 {
7595 }
7599 else
7600 {
7601 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7602 will mark the function as addressed, but here we must do it
7603 explicitly. */
7607 }
7608 }
7610 /* This function will instantiate the type of the expression given in
7611 RHS to match the type of LHSTYPE. If errors exist, then return
7612 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7613 we complain on errors. If we are not complaining, never modify rhs,
7614 as overload resolution wants to try many possible instantiations, in
7615 the hope that at least one will work.
7617 For non-recursive calls, LHSTYPE should be a function, pointer to
7618 function, or a pointer to member function. */
7620 tree
7622 {
7629 {
7633 }
7636 {
7643 /* Microsoft allows `A::f' to be resolved to a
7644 pointer-to-member. */
7645 ;
7646 else
7647 {
7652 }
7653 }
7656 {
7659 }
7661 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7662 deduce any type information. */
7664 {
7668 }
7670 /* There only a few kinds of expressions that may have a type
7671 dependent on overload resolution. */
7677 /* This should really only be used when attempting to distinguish
7678 what sort of a pointer to function we have. For now, any
7679 arithmetic operation which is not supported on pointers
7680 is rejected as an error. */
7683 {
7685 {
7691 /* Do not lose object's side effects. */
7695 }
7702 /* This can happen if we are forming a pointer-to-member for a
7703 member template. */
7706 /* Fall through. */
7709 {
7713 return
7717 }
7721 return
7725 access_path);
7728 {
7733 }
7740 }
7742 }
7743 \f
7744 /* Return the name of the virtual function pointer field
7745 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7746 this may have to look back through base types to find the
7747 ultimate field name. (For single inheritance, these could
7748 all be the same name. Who knows for multiple inheritance). */
7750 static tree
7752 {
7759 {
7765 }
7773 }
7775 void
7777 {
7784 {
7789 }
7790 }
7792 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7793 according to [class]:
7794 The class-name is also inserted
7795 into the scope of the class itself. For purposes of access checking,
7796 the inserted class name is treated as if it were a public member name. */
7798 void
7800 {
7803 tree saved_cas;
7818 }
7820 /* Returns 1 if TYPE contains only padding bytes. */
7822 int
7824 {
7831 /* In G++ 3.2, whether or not a class was empty was determined by
7832 looking at its size. */
7835 else
7837 }
7839 /* Returns true if TYPE contains an empty class. */
7841 static bool
7843 {
7847 {
7848 tree field;
7849 tree binfo;
7850 tree base_binfo;
7862 }
7866 }
7868 /* Returns true if TYPE contains no actual data, just various
7869 possible combinations of empty classes and possibly a vptr. */
7871 bool
7873 {
7875 {
7876 tree field;
7877 tree binfo;
7878 tree base_binfo;
7881 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7882 out, but we'd like to be able to check this before then. */
7896 }
7900 }
7902 /* Note that NAME was looked up while the current class was being
7903 defined and that the result of that lookup was DECL. */
7905 void
7907 {
7908 splay_tree names_used;
7910 /* If we're not defining a class, there's nothing to do. */
7916 /* If there's already a binding for this NAME, then we don't have
7917 anything to worry about. */
7930 }
7932 /* Note that NAME was declared (as DECL) in the current class. Check
7933 to see that the declaration is valid. */
7935 void
7937 {
7938 splay_tree names_used;
7939 splay_tree_node n;
7941 /* Look to see if we ever used this name. */
7942 names_used
7946 /* The C language allows members to be declared with a type of the same
7947 name, and the C++ standard says this diagnostic is not required. So
7948 allow it in extern "C" blocks unless predantic is specified.
7949 Allow it in all cases if -ms-extensions is specified. */
7955 {
7956 /* [basic.scope.class]
7958 A name N used in a class S shall refer to the same declaration
7959 in its context and when re-evaluated in the completed scope of
7960 S. */
7964 }
7965 }
7967 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7968 Secondary vtables are merged with primary vtables; this function
7969 will return the VAR_DECL for the primary vtable. */
7971 tree
7973 {
7974 tree decl;
7978 {
7981 }
7985 }
7988 /* Returns the binfo for the primary base of BINFO. If the resulting
7989 BINFO is a virtual base, and it is inherited elsewhere in the
7990 hierarchy, then the returned binfo might not be the primary base of
7991 BINFO in the complete object. Check BINFO_PRIMARY_P or
7992 BINFO_LOST_PRIMARY_P to be sure. */
7994 static tree
7996 {
7997 tree primary_base;
8004 }
8006 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8008 static int
8010 {
8014 }
8016 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8017 INDENT should be zero when called from the top level; it is
8018 incremented recursively. IGO indicates the next expected BINFO in
8019 inheritance graph ordering. */
8021 static tree
8024 tree binfo,
8025 tree igo,
8027 {
8029 tree base_binfo;
8037 {
8040 }
8055 {
8059 TFF_PLAIN_IDENTIFIER),
8061 }
8063 {
8066 }
8071 {
8075 {
8079 TFF_PLAIN_IDENTIFIER));
8080 }
8082 {
8086 TFF_PLAIN_IDENTIFIER));
8087 }
8089 {
8093 TFF_PLAIN_IDENTIFIER));
8094 }
8096 {
8100 TFF_PLAIN_IDENTIFIER));
8101 }
8105 }
8111 }
8113 /* Dump the BINFO hierarchy for T. */
8115 static void
8117 {
8129 }
8131 /* Debug interface to hierarchy dumping. */
8133 void
8135 {
8137 }
8139 static void
8141 {
8146 {
8149 }
8150 }
8152 static void
8154 {
8155 tree value;
8157 HOST_WIDE_INT elt;
8165 TFF_PLAIN_IDENTIFIER));
8172 }
8174 static void
8176 {
8184 {
8191 {
8196 }
8200 }
8203 }
8205 static void
8207 {
8215 {
8220 }
8223 }
8225 /* Dump a function or thunk and its thunkees. */
8227 static void
8229 {
8232 tree thunks;
8240 {
8250 else
8256 }
8260 }
8262 /* Dump the thunks for FN. */
8264 void
8266 {
8268 }
8270 /* Virtual function table initialization. */
8272 /* Create all the necessary vtables for T and its base classes. */
8274 static void
8276 {
8277 tree vbase;
8281 /* We lay out the primary and secondary vtables in one contiguous
8282 vtable. The primary vtable is first, followed by the non-virtual
8283 secondary vtables in inheritance graph order. */
8287 /* Then come the virtual bases, also in inheritance graph order. */
8289 {
8293 }
8297 }
8299 /* Initialize the vtable for BINFO with the INITS. */
8301 static void
8303 {
8304 tree decl;
8310 }
8312 /* Build the VTT (virtual table table) for T.
8313 A class requires a VTT if it has virtual bases.
8315 This holds
8316 1 - primary virtual pointer for complete object T
8317 2 - secondary VTTs for each direct non-virtual base of T which requires a
8318 VTT
8319 3 - secondary virtual pointers for each direct or indirect base of T which
8320 has virtual bases or is reachable via a virtual path from T.
8321 4 - secondary VTTs for each direct or indirect virtual base of T.
8323 Secondary VTTs look like complete object VTTs without part 4. */
8325 static void
8327 {
8328 tree type;
8329 tree vtt;
8330 tree index;
8333 /* Build up the initializers for the VTT. */
8338 /* If we didn't need a VTT, we're done. */
8342 /* Figure out the type of the VTT. */
8346 /* Now, build the VTT object itself. */
8349 /* Add the VTT to the vtables list. */
8354 }
8356 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8357 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8358 and CHAIN the vtable pointer for this binfo after construction is
8359 complete. VALUE can also be another BINFO, in which case we recurse. */
8361 static tree
8363 {
8364 tree vt;
8367 {
8373 else
8375 }
8378 }
8380 /* Data for secondary VTT initialization. */
8382 {
8383 /* Is this the primary VTT? */
8386 /* Current index into the VTT. */
8387 tree index;
8389 /* Vector of initializers built up. */
8392 /* The type being constructed by this secondary VTT. */
8393 tree type_being_constructed;
8396 /* Recursively build the VTT-initializer for BINFO (which is in the
8397 hierarchy dominated by T). INITS points to the end of the initializer
8398 list to date. INDEX is the VTT index where the next element will be
8399 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8400 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8401 for virtual bases of T. When it is not so, we build the constructor
8402 vtables for the BINFO-in-T variant. */
8404 static void
8407 {
8409 tree b;
8410 tree init;
8411 secondary_vptr_vtt_init_data data;
8414 /* We only need VTTs for subobjects with virtual bases. */
8418 /* We need to use a construction vtable if this is not the primary
8419 VTT. */
8421 {
8424 /* Record the offset in the VTT where this sub-VTT can be found. */
8426 }
8428 /* Add the address of the primary vtable for the complete object. */
8432 {
8435 }
8438 /* Recursively add the secondary VTTs for non-virtual bases. */
8443 /* Add secondary virtual pointers for all subobjects of BINFO with
8444 either virtual bases or reachable along a virtual path, except
8445 subobjects that are non-virtual primary bases. */
8455 /* data.inits might have grown as we added secondary virtual pointers.
8456 Make sure our caller knows about the new vector. */
8460 /* Add the secondary VTTs for virtual bases in inheritance graph
8461 order. */
8463 {
8468 }
8469 else
8470 /* Remove the ctor vtables we created. */
8472 }
8474 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8475 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8477 static tree
8479 {
8482 /* We don't care about bases that don't have vtables. */
8486 /* We're only interested in proper subobjects of the type being
8487 constructed. */
8491 /* We're only interested in bases with virtual bases or reachable
8492 via a virtual path from the type being constructed. */
8497 /* We're not interested in non-virtual primary bases. */
8501 /* Record the index where this secondary vptr can be found. */
8503 {
8508 {
8509 /* It's a primary virtual base, and this is not a
8510 construction vtable. Find the base this is primary of in
8511 the inheritance graph, and use that base's vtable
8512 now. */
8515 }
8516 }
8518 /* Add the initializer for the secondary vptr itself. */
8521 /* Advance the vtt index. */
8526 }
8528 /* Called from build_vtt_inits via dfs_walk. After building
8529 constructor vtables and generating the sub-vtt from them, we need
8530 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8531 binfo of the base whose sub vtt was generated. */
8533 static tree
8535 {
8539 /* If this class has no vtable, none of its bases do. */
8543 /* This might be a primary base, so have no vtable in this
8544 hierarchy. */
8547 /* If we scribbled the construction vtable vptr into BINFO, clear it
8548 out now. */
8554 }
8556 /* Build the construction vtable group for BINFO which is in the
8557 hierarchy dominated by T. */
8559 static void
8561 {
8562 tree type;
8563 tree vtbl;
8564 tree id;
8565 tree vbase;
8568 /* See if we've already created this construction vtable group. */
8574 /* Build a version of VTBL (with the wrong type) for use in
8575 constructing the addresses of secondary vtables in the
8576 construction vtable group. */
8579 /* Don't export construction vtables from shared libraries. Even on
8580 targets that don't support hidden visibility, this tells
8581 can_refer_decl_in_current_unit_p not to assume that it's safe to
8582 access from a different compilation unit (bz 54314). */
8590 /* Add the vtables for each of our virtual bases using the vbase in T
8591 binfo. */
8593 vbase;
8595 {
8596 tree b;
8603 }
8605 /* Figure out the type of the construction vtable. */
8612 /* Initialize the construction vtable. */
8616 }
8618 /* Add the vtbl initializers for BINFO (and its bases other than
8619 non-virtual primaries) to the list of INITS. BINFO is in the
8620 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8621 the constructor the vtbl inits should be accumulated for. (If this
8622 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8623 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8624 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8625 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8626 but are not necessarily the same in terms of layout. */
8628 static void
8630 tree orig_binfo,
8631 tree rtti_binfo,
8632 tree vtbl,
8633 tree t,
8635 {
8637 tree base_binfo;
8642 /* If it doesn't have a vptr, we don't do anything. */
8646 /* If we're building a construction vtable, we're not interested in
8647 subobjects that don't require construction vtables. */
8653 /* Build the initializers for the BINFO-in-T vtable. */
8656 /* Walk the BINFO and its bases. We walk in preorder so that as we
8657 initialize each vtable we can figure out at what offset the
8658 secondary vtable lies from the primary vtable. We can't use
8659 dfs_walk here because we need to iterate through bases of BINFO
8660 and RTTI_BINFO simultaneously. */
8662 {
8663 /* Skip virtual bases. */
8669 inits);
8670 }
8671 }
8673 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8674 BINFO vtable to L. */
8676 static void
8678 tree orig_binfo,
8679 tree rtti_binfo,
8680 tree orig_vtbl,
8681 tree t,
8683 {
8690 {
8691 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8692 primary virtual base. If it is not the same primary in
8693 the hierarchy of T, we'll need to generate a ctor vtable
8694 for it, to place at its location in T. If it is the same
8695 primary, we still need a VTT entry for the vtable, but it
8696 should point to the ctor vtable for the base it is a
8697 primary for within the sub-hierarchy of RTTI_BINFO.
8699 There are three possible cases:
8701 1) We are in the same place.
8702 2) We are a primary base within a lost primary virtual base of
8703 RTTI_BINFO.
8704 3) We are primary to something not a base of RTTI_BINFO. */
8706 tree b;
8709 /* First, look through the bases we are primary to for RTTI_BINFO
8710 or a virtual base. */
8713 {
8718 }
8719 /* If we run out of primary links, keep looking down our
8720 inheritance chain; we might be an indirect primary. */
8724 found:
8726 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8727 base B and it is a base of RTTI_BINFO, this is case 2. In
8728 either case, we share our vtable with LAST, i.e. the
8729 derived-most base within B of which we are a primary. */
8732 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8733 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8734 binfo_ctor_vtable after everything's been set up. */
8737 /* Otherwise, this is case 3 and we get our own. */
8738 }
8745 {
8746 tree index;
8749 /* Add the initializer for this vtable. */
8753 /* Figure out the position to which the VPTR should point. */
8759 }
8762 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8763 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8764 straighten this out. */
8767 /* Throw away any unneeded intializers. */
8769 else
8770 /* For an ordinary vtable, set BINFO_VTABLE. */
8772 }
8776 /* Construct the initializer for BINFO's virtual function table. BINFO
8777 is part of the hierarchy dominated by T. If we're building a
8778 construction vtable, the ORIG_BINFO is the binfo we should use to
8779 find the actual function pointers to put in the vtable - but they
8780 can be overridden on the path to most-derived in the graph that
8781 ORIG_BINFO belongs. Otherwise,
8782 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8783 BINFO that should be indicated by the RTTI information in the
8784 vtable; it will be a base class of T, rather than T itself, if we
8785 are building a construction vtable.
8787 The value returned is a TREE_LIST suitable for wrapping in a
8788 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8789 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8790 number of non-function entries in the vtable.
8792 It might seem that this function should never be called with a
8793 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8794 base is always subsumed by a derived class vtable. However, when
8795 we are building construction vtables, we do build vtables for
8796 primary bases; we need these while the primary base is being
8797 constructed. */
8799 static void
8801 tree orig_binfo,
8802 tree t,
8803 tree rtti_binfo,
8806 {
8807 tree v;
8808 vtbl_init_data vid;
8810 tree vbinfo;
8814 /* Initialize VID. */
8822 /* The first vbase or vcall offset is at index -3 in the vtable. */
8825 /* Add entries to the vtable for RTTI. */
8828 /* Create an array for keeping track of the functions we've
8829 processed. When we see multiple functions with the same
8830 signature, we share the vcall offsets. */
8832 /* Add the vcall and vbase offset entries. */
8835 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8836 build_vbase_offset_vtbl_entries. */
8841 /* If the target requires padding between data entries, add that now. */
8843 {
8848 /* Move data entries into their new positions and add padding
8849 after the new positions. Iterate backwards so we don't
8850 overwrite entries that we would need to process later. */
8853 ix--)
8854 {
8862 {
8866 null_pointer_node);
8867 }
8868 }
8869 }
8874 /* The initializers for virtual functions were built up in reverse
8875 order. Straighten them out and add them to the running list in one
8876 step. */
8885 /* Go through all the ordinary virtual functions, building up
8886 initializers. */
8888 {
8889 tree delta;
8890 tree vcall_index;
8897 {
8901 {
8904 }
8906 }
8908 /* If the only definition of this function signature along our
8909 primary base chain is from a lost primary, this vtable slot will
8910 never be used, so just zero it out. This is important to avoid
8911 requiring extra thunks which cannot be generated with the function.
8913 We first check this in update_vtable_entry_for_fn, so we handle
8914 restored primary bases properly; we also need to do it here so we
8915 zero out unused slots in ctor vtables, rather than filling them
8916 with erroneous values (though harmless, apart from relocation
8917 costs). */
8922 {
8923 /* Pull the offset for `this', and the function to call, out of
8924 the list. */
8931 /* You can't call an abstract virtual function; it's abstract.
8932 So, we replace these functions with __pure_virtual. */
8934 {
8937 {
8939 abort_fndecl_addr
8943 }
8944 }
8945 /* Likewise for deleted virtuals. */
8947 {
8956 }
8957 else
8958 {
8960 {
8964 }
8965 /* Take the address of the function, considering it to be of an
8966 appropriate generic type. */
8970 }
8971 }
8973 /* And add it to the chain of initializers. */
8975 {
8980 else
8982 {
8988 }
8989 }
8990 else
8992 }
8993 }
8995 /* Adds to vid->inits the initializers for the vbase and vcall
8996 offsets in BINFO, which is in the hierarchy dominated by T. */
8998 static void
9000 {
9001 tree b;
9003 /* If this is a derived class, we must first create entries
9004 corresponding to the primary base class. */
9009 /* Add the vbase entries for this base. */
9011 /* Add the vcall entries for this base. */
9013 }
9015 /* Returns the initializers for the vbase offset entries in the vtable
9016 for BINFO (which is part of the class hierarchy dominated by T), in
9017 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9018 where the next vbase offset will go. */
9020 static void
9022 {
9023 tree vbase;
9024 tree t;
9025 tree non_primary_binfo;
9027 /* If there are no virtual baseclasses, then there is nothing to
9028 do. */
9034 /* We might be a primary base class. Go up the inheritance hierarchy
9035 until we find the most derived class of which we are a primary base:
9036 it is the offset of that which we need to use. */
9039 {
9040 tree b;
9042 /* If we have reached a virtual base, then it must be a primary
9043 base (possibly multi-level) of vid->binfo, or we wouldn't
9044 have called build_vcall_and_vbase_vtbl_entries for it. But it
9045 might be a lost primary, so just skip down to vid->binfo. */
9047 {
9050 }
9056 }
9058 /* Go through the virtual bases, adding the offsets. */
9060 vbase;
9062 {
9063 tree b;
9064 tree delta;
9069 /* Find the instance of this virtual base in the complete
9070 object. */
9073 /* If we've already got an offset for this virtual base, we
9074 don't need another one. */
9079 /* Figure out where we can find this vbase offset. */
9088 /* The vbase offset had better be the same. */
9091 /* The next vbase will come at a more negative offset. */
9095 /* The initializer is the delta from BINFO to this virtual base.
9096 The vbase offsets go in reverse inheritance-graph order, and
9097 we are walking in inheritance graph order so these end up in
9098 the right order. */
9105 }
9106 }
9108 /* Adds the initializers for the vcall offset entries in the vtable
9109 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9110 to VID->INITS. */
9112 static void
9114 {
9115 /* We only need these entries if this base is a virtual base. We
9116 compute the indices -- but do not add to the vtable -- when
9117 building the main vtable for a class. */
9120 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9121 correspond to VID->DERIVED), we are building a primary
9122 construction virtual table. Since this is a primary
9123 virtual table, we do not need the vcall offsets for
9124 BINFO. */
9126 {
9127 /* We need a vcall offset for each of the virtual functions in this
9128 vtable. For example:
9130 class A { virtual void f (); };
9131 class B1 : virtual public A { virtual void f (); };
9132 class B2 : virtual public A { virtual void f (); };
9133 class C: public B1, public B2 { virtual void f (); };
9135 A C object has a primary base of B1, which has a primary base of A. A
9136 C also has a secondary base of B2, which no longer has a primary base
9137 of A. So the B2-in-C construction vtable needs a secondary vtable for
9138 A, which will adjust the A* to a B2* to call f. We have no way of
9139 knowing what (or even whether) this offset will be when we define B2,
9140 so we store this "vcall offset" in the A sub-vtable and look it up in
9141 a "virtual thunk" for B2::f.
9143 We need entries for all the functions in our primary vtable and
9144 in our non-virtual bases' secondary vtables. */
9146 /* If we are just computing the vcall indices -- but do not need
9147 the actual entries -- not that. */
9150 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9152 }
9153 }
9155 /* Build vcall offsets, starting with those for BINFO. */
9157 static void
9159 {
9161 tree primary_binfo;
9162 tree base_binfo;
9164 /* Don't walk into virtual bases -- except, of course, for the
9165 virtual base for which we are building vcall offsets. Any
9166 primary virtual base will have already had its offsets generated
9167 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9171 /* If BINFO has a primary base, process it first. */
9176 /* Add BINFO itself to the list. */
9179 /* Scan the non-primary bases of BINFO. */
9183 }
9185 /* Called from build_vcall_offset_vtbl_entries_r. */
9187 static void
9189 {
9190 /* Make entries for the rest of the virtuals. */
9192 {
9193 tree orig_fn;
9195 /* The ABI requires that the methods be processed in declaration
9196 order. G++ 3.2 used the order in the vtable. */
9198 orig_fn;
9202 }
9203 else
9204 {
9205 tree derived_virtuals;
9206 tree base_virtuals;
9207 tree orig_virtuals;
9208 /* If BINFO is a primary base, the most derived class which has
9209 BINFO as a primary base; otherwise, just BINFO. */
9210 tree non_primary_binfo;
9212 /* We might be a primary base class. Go up the inheritance hierarchy
9213 until we find the most derived class of which we are a primary base:
9214 it is the BINFO_VIRTUALS there that we need to consider. */
9217 {
9218 tree b;
9220 /* If we have reached a virtual base, then it must be vid->vbase,
9221 because we ignore other virtual bases in
9222 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9223 base (possibly multi-level) of vid->binfo, or we wouldn't
9224 have called build_vcall_and_vbase_vtbl_entries for it. But it
9225 might be a lost primary, so just skip down to vid->binfo. */
9227 {
9231 }
9237 }
9240 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9241 where rtti_binfo is the most derived type. */
9242 non_primary_binfo
9248 base_virtuals;
9252 {
9253 tree orig_fn;
9255 /* Find the declaration that originally caused this function to
9256 be present in BINFO_TYPE (binfo). */
9259 /* When processing BINFO, we only want to generate vcall slots for
9260 function slots introduced in BINFO. So don't try to generate
9261 one if the function isn't even defined in BINFO. */
9266 }
9267 }
9268 }
9270 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9272 static void
9274 {
9276 tree vcall_offset;
9277 tree derived_entry;
9279 /* If there is already an entry for a function with the same
9280 signature as FN, then we do not need a second vcall offset.
9281 Check the list of functions already present in the derived
9282 class vtable. */
9284 {
9286 /* We only use one vcall offset for virtual destructors,
9287 even though there are two virtual table entries. */
9291 }
9293 /* If we are building these vcall offsets as part of building
9294 the vtable for the most derived class, remember the vcall
9295 offset. */
9297 {
9300 }
9302 /* The next vcall offset will be found at a more negative
9303 offset. */
9307 /* Keep track of this function. */
9311 {
9312 tree base;
9313 tree fn;
9315 /* Find the overriding function. */
9319 else
9320 {
9323 /* The vbase we're working on is a primary base of
9324 vid->binfo. But it might be a lost primary, so its
9325 BINFO_OFFSET might be wrong, so we just use the
9326 BINFO_OFFSET from vid->binfo. */
9332 vcall_offset);
9333 }
9334 /* Add the initializer to the vtable. */
9336 }
9337 }
9339 /* Return vtbl initializers for the RTTI entries corresponding to the
9340 BINFO's vtable. The RTTI entries should indicate the object given
9341 by VID->rtti_binfo. */
9343 static void
9345 {
9346 tree b;
9347 tree t;
9348 tree offset;
9349 tree decl;
9350 tree init;
9354 /* To find the complete object, we will first convert to our most
9355 primary base, and then add the offset in the vtbl to that value. */
9359 {
9360 tree primary_base;
9366 }
9370 /* The second entry is the address of the typeinfo object. */
9373 else
9376 /* Convert the declaration to a type that can be stored in the
9377 vtable. */
9381 /* Add the offset-to-top entry. It comes earlier in the vtable than
9382 the typeinfo entry. Convert the offset to look like a
9383 function pointer, so that we can put it in the vtable. */
9386 }
9388 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9389 accessibility. */
9391 bool
9393 {
9396 }
9398 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9400 bool
9402 {
9406 }
9408 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9409 class between them, if any. */
9411 tree
9413 {
9425 {
9428 }
9432 }