| blob | b936ac85ad7956ebbbca0b4080c648234803dcbf |
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. */
40 /* The number of nested classes being processed. If we are not in the
41 scope of any class, this is zero. */
45 /* In order to deal with nested classes, we keep a stack of classes.
46 The topmost entry is the innermost class, and is the entry at index
47 CURRENT_CLASS_DEPTH */
50 /* The name of the class. */
51 tree name;
53 /* The _TYPE node for the class. */
54 tree type;
56 /* The access specifier pending for new declarations in the scope of
57 this class. */
58 tree access;
60 /* If were defining TYPE, the names used in this class. */
61 splay_tree names_used;
63 /* Nonzero if this class is no longer open, because of a call to
64 push_to_top_level. */
69 {
70 /* The base for which we're building initializers. */
71 tree binfo;
72 /* The type of the most-derived type. */
73 tree derived;
74 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
75 unless ctor_vtbl_p is true. */
76 tree rtti_binfo;
77 /* The negative-index vtable initializers built up so far. These
78 are in order from least negative index to most negative index. */
80 /* The binfo for the virtual base for which we're building
81 vcall offset initializers. */
82 tree vbase;
83 /* The functions in vbase for which we have already provided vcall
84 offsets. */
86 /* The vtable index of the next vcall or vbase offset. */
87 tree index;
88 /* Nonzero if we are building the initializer for the primary
89 vtable. */
91 /* Nonzero if we are building the initializer for a construction
92 vtable. */
94 /* True when adding vcall offset entries to the vtable. False when
95 merely computing the indices. */
99 /* The type of a function passed to walk_subobject_offsets. */
102 /* The stack itself. This is a dynamically resized array. The
103 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
107 /* The size of the largest empty class seen in this translation unit. */
110 /* An array of all local classes present in this translation unit, in
111 declaration order. */
193 tree *);
203 splay_tree_key k2);
212 /* Variables shared between class.c and call.c. */
222 /* Convert to or from a base subobject. EXPR is an expression of type
223 `A' or `A*', an expression of type `B' or `B*' is returned. To
224 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
225 the B base instance within A. To convert base A to derived B, CODE
226 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
227 In this latter case, A must not be a morally virtual base of B.
228 NONNULL is true if EXPR is known to be non-NULL (this is only
229 needed when EXPR is of pointer type). CV qualifiers are preserved
230 from EXPR. */
232 tree
234 tree expr,
235 tree binfo,
237 tsubst_flags_t complain)
238 {
241 tree probe;
242 tree offset;
243 tree target_type;
245 tree ptr_target_type;
255 {
261 }
269 {
270 /* This can happen when adjust_result_of_qualified_name_lookup can't
271 find a unique base binfo in a call to a member function. We
272 couldn't give the diagnostic then since we might have been calling
273 a static member function, so we do it now. */
275 {
279 }
281 }
288 /* Nothing to do. */
292 {
298 }
301 /* This must happen before the call to save_expr. */
303 else
309 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
310 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
311 expression returned matches the input. */
312 target_type = cp_build_qualified_type
316 /* Do we need to look in the vtable for the real offset? */
319 /* Don't bother with the calculations inside sizeof; they'll ICE if the
320 source type is incomplete and the pointer value doesn't matter. In a
321 template (even in fold_non_dependent_expr), we don't have vtables set
322 up properly yet, and the value doesn't matter there either; we're just
323 interested in the result of overload resolution. */
326 {
331 }
333 /* If we're in an NSDMI, we don't have the full constructor context yet
334 that we need for converting to a virtual base, so just build a stub
335 CONVERT_EXPR and expand it later in bot_replace. */
338 {
344 }
346 /* Do we need to check for a null pointer? */
348 {
349 /* If we know the conversion will not actually change the value
350 of EXPR, then we can avoid testing the expression for NULL.
351 We have to avoid generating a COMPONENT_REF for a base class
352 field, because other parts of the compiler know that such
353 expressions are always non-NULL. */
357 }
359 /* Protect against multiple evaluation if necessary. */
363 /* Now that we've saved expr, build the real null test. */
365 {
369 }
371 /* If this is a simple base reference, express it as a COMPONENT_REF. */
373 /* We don't build base fields for empty bases, and they aren't very
374 interesting to the optimizers anyway. */
376 {
383 }
386 {
387 /* Going via virtual base V_BINFO. We need the static offset
388 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
389 V_BINFO. That offset is an entry in D_BINFO's vtable. */
390 tree v_offset;
393 {
394 /* In a base member initializer, we cannot rely on the
395 vtable being set up. We have to indirect via the
396 vtt_parm. */
397 tree t;
403 }
404 else
406 complain),
412 v_offset);
424 /* Negative fixed_type_p means this is a constructor or destructor;
425 virtual base layout is fixed in in-charge [cd]tors, but not in
426 base [cd]tors. */
430 v_offset,
433 else
435 }
443 {
448 }
449 else
455 out:
461 }
463 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
464 Perform a derived-to-base conversion by recursively building up a
465 sequence of COMPONENT_REFs to the appropriate base fields. */
467 static tree
469 {
472 tree field;
475 {
476 tree temp;
480 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
481 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
482 an lvalue in the front end; only _DECLs and _REFs are lvalues
483 in the back end. */
489 }
491 /* Recurse. */
496 /* Is this the base field created by build_base_field? */
500 /* If we're looking for a field in the most-derived class,
501 also check the field offset; we can have two base fields
502 of the same type if one is an indirect virtual base and one
503 is a direct non-virtual base. */
507 {
508 /* We don't use build_class_member_access_expr here, as that
509 has unnecessary checks, and more importantly results in
510 recursive calls to dfs_walk_once. */
518 /* Mark the expression const or volatile, as appropriate.
519 Even though we've dealt with the type above, we still have
520 to mark the expression itself. */
527 }
529 /* Didn't find the base field?!? */
531 }
533 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
534 type is a class type or a pointer to a class type. In the former
535 case, TYPE is also a class type; in the latter it is another
536 pointer type. If CHECK_ACCESS is true, an error message is emitted
537 if TYPE is inaccessible. If OBJECT has pointer type, the value is
538 assumed to be non-NULL. */
540 tree
542 tsubst_flags_t complain)
543 {
544 tree binfo;
545 tree object_type;
548 {
551 }
552 else
561 }
563 /* EXPR is an expression with unqualified class type. BASE is a base
564 binfo of that class type. Returns EXPR, converted to the BASE
565 type. This function assumes that EXPR is the most derived class;
566 therefore virtual bases can be found at their static offsets. */
568 tree
570 {
571 tree expr_type;
575 {
576 /* If this is a non-empty base, use a COMPONENT_REF. */
580 /* We use fold_build2 and fold_convert below to simplify the trees
581 provided to the optimizers. It is not safe to call these functions
582 when processing a template because they do not handle C++-specific
583 trees. */
591 }
594 }
596 \f
597 tree
599 {
605 /* First, convert to the requested type. */
610 /* Second, the requested type may not be the owner of its own vptr.
611 If not, convert to the base class that owns it. We cannot use
612 convert_to_base here, because VCONTEXT may appear more than once
613 in the inheritance hierarchy of TYPE, and thus direct conversion
614 between the types may be ambiguous. Following the path back up
615 one step at a time via primary bases avoids the problem. */
619 {
622 }
625 }
627 /* Given an object INSTANCE, return an expression which yields the
628 vtable element corresponding to INDEX. There are many special
629 cases for INSTANCE which we take care of here, mainly to avoid
630 creating extra tree nodes when we don't have to. */
632 static tree
634 {
635 tree aref;
638 /* Try to figure out what a reference refers to, and
639 access its virtual function table directly. */
647 {
652 }
661 }
663 tree
665 {
669 }
671 /* Given a stable object pointer INSTANCE_PTR, return an expression which
672 yields a function pointer corresponding to vtable element INDEX. */
674 tree
676 {
677 tree aref;
680 tf_warning_or_error),
681 idx);
683 /* When using function descriptors, the address of the
684 vtable entry is treated as a function pointer. */
689 /* Remember this as a method reference, for later devirtualization. */
693 }
695 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
696 for the given TYPE. */
698 static tree
700 {
702 }
704 /* DECL is an entity associated with TYPE, like a virtual table or an
705 implicitly generated constructor. Determine whether or not DECL
706 should have external or internal linkage at the object file
707 level. This routine does not deal with COMDAT linkage and other
708 similar complexities; it simply sets TREE_PUBLIC if it possible for
709 entities in other translation units to contain copies of DECL, in
710 the abstract. */
712 void
714 {
717 }
719 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
720 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
721 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
723 static tree
725 {
726 tree decl;
729 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
730 now to avoid confusion in mangle_decl. */
739 /* At one time the vtable info was grabbed 2 words at a time. This
740 fails on sparc unless you have 8-byte alignment. (tiemann) */
744 /* The vtable has not been defined -- yet. */
748 /* Mark the VAR_DECL node representing the vtable itself as a
749 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
750 is rather important that such things be ignored because any
751 effort to actually generate DWARF for them will run into
752 trouble when/if we encounter code like:
754 #pragma interface
755 struct S { virtual void member (); };
757 because the artificial declaration of the vtable itself (as
758 manufactured by the g++ front end) will say that the vtable is
759 a static member of `S' but only *after* the debug output for
760 the definition of `S' has already been output. This causes
761 grief because the DWARF entry for the definition of the vtable
762 will try to refer back to an earlier *declaration* of the
763 vtable as a static member of `S' and there won't be one. We
764 might be able to arrange to have the "vtable static member"
765 attached to the member list for `S' before the debug info for
766 `S' get written (which would solve the problem) but that would
767 require more intrusive changes to the g++ front end. */
771 }
773 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
774 or even complete. If this does not exist, create it. If COMPLETE is
775 nonzero, then complete the definition of it -- that will render it
776 impossible to actually build the vtable, but is useful to get at those
777 which are known to exist in the runtime. */
779 tree
781 {
782 tree decl;
791 {
794 }
797 }
799 /* Build the primary virtual function table for TYPE. If BINFO is
800 non-NULL, build the vtable starting with the initial approximation
801 that it is the same as the one which is the head of the association
802 list. Returns a nonzero value if a new vtable is actually
803 created. */
805 static int
807 {
808 tree decl;
809 tree virtuals;
814 {
816 /* We have already created a vtable for this base, so there's
817 no need to do it again. */
824 }
825 else
826 {
829 }
832 {
835 }
837 /* Initialize the association list for this type, based
838 on our first approximation. */
843 }
845 /* Give BINFO a new virtual function table which is initialized
846 with a skeleton-copy of its original initialization. The only
847 entry that changes is the `delta' entry, so we can really
848 share a lot of structure.
850 FOR_TYPE is the most derived type which caused this table to
851 be needed.
853 Returns nonzero if we haven't met BINFO before.
855 The order in which vtables are built (by calling this function) for
856 an object must remain the same, otherwise a binary incompatibility
857 can result. */
859 static int
861 {
863 /* We already created a vtable for this base. There's no need to
864 do it again. */
867 /* Remember that we've created a vtable for this BINFO, so that we
868 don't try to do so again. */
871 /* Make fresh virtual list, so we can smash it later. */
874 /* Secondary vtables are laid out as part of the same structure as
875 the primary vtable. */
878 }
880 /* Create a new vtable for BINFO which is the hierarchy dominated by
881 T. Return nonzero if we actually created a new vtable. */
883 static int
885 {
887 /* In this case, it is *type*'s vtable we are modifying. We start
888 with the approximation that its vtable is that of the
889 immediate base class. */
891 else
892 /* This is our very own copy of `basetype' to play with. Later,
893 we will fill in all the virtual functions that override the
894 virtual functions in these base classes which are not defined
895 by the current type. */
897 }
899 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
900 (which is in the hierarchy dominated by T) list FNDECL as its
901 BV_FN. DELTA is the required constant adjustment from the `this'
902 pointer where the vtable entry appears to the `this' required when
903 the function is actually called. */
905 static void
907 tree binfo,
908 tree fndecl,
909 tree delta,
911 {
912 tree v;
918 {
919 /* We need a new vtable for BINFO. */
921 {
922 /* If we really did make a new vtable, we also made a copy
923 of the BINFO_VIRTUALS list. Now, we have to find the
924 corresponding entry in that list. */
929 }
934 }
935 }
937 \f
938 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
939 the USING_DECL naming METHOD. Returns true if the method could be
940 added to the method vec. */
942 bool
944 {
946 tree overload;
952 tree current_fns;
953 tree fns;
966 {
967 /* Make a new method vector. We start with 8 entries. We must
968 allocate at least two (for constructors and destructors), and
969 we're going to end up with an assignment operator at some
970 point as well. */
972 /* Create slots for constructors and destructors. */
976 }
978 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
981 /* Constructors and destructors go in special slots. */
985 {
989 {
995 type);
996 }
997 }
998 else
999 {
1000 tree m;
1003 /* See if we already have an entry with this name. */
1007 {
1010 {
1015 }
1019 {
1022 }
1027 }
1028 }
1031 /* Check to see if we've already got this method. */
1033 {
1035 tree fn_type;
1036 tree method_type;
1037 tree parms1;
1038 tree parms2;
1043 /* [over.load] Member function declarations with the
1044 same name and the same parameter types cannot be
1045 overloaded if any of them is a static member
1046 function declaration.
1048 [over.load] Member function declarations with the same name and
1049 the same parameter-type-list as well as member function template
1050 declarations with the same name, the same parameter-type-list, and
1051 the same template parameter lists cannot be overloaded if any of
1052 them, but not all, have a ref-qualifier.
1054 [namespace.udecl] When a using-declaration brings names
1055 from a base class into a derived class scope, member
1056 functions in the derived class override and/or hide member
1057 functions with the same name and parameter types in a base
1058 class (rather than conflicting). */
1064 /* Compare the quals on the 'this' parm. Don't compare
1065 the whole types, as used functions are treated as
1066 coming from the using class in overload resolution. */
1069 /* Either both or neither need to be ref-qualified for
1070 differing quals to allow overloading. */
1077 /* For templates, the return type and template parameters
1078 must be identical. */
1095 {
1096 /* For function versions, their parms and types match
1097 but they are not duplicates. Record function versions
1098 as and when they are found. extern "C" functions are
1099 not treated as versions. */
1105 {
1106 /* Mark functions as versions if necessary. Modify the mangled
1107 decl name if necessary. */
1109 {
1113 }
1115 {
1119 }
1122 }
1124 {
1126 {
1133 }
1134 /* Otherwise defer to the other function. */
1136 }
1138 {
1140 /* Defer to the local function. */
1142 }
1143 else
1144 {
1147 }
1149 /* We don't call duplicate_decls here to merge the
1150 declarations because that will confuse things if the
1151 methods have inline definitions. In particular, we
1152 will crash while processing the definitions. */
1154 }
1155 }
1157 /* A class should never have more than one destructor. */
1161 /* Add the new binding. */
1163 {
1166 }
1167 else
1176 {
1179 /* We only expect to add few methods in the COMPLETE_P case, so
1180 just make room for one more method in that case. */
1183 else
1189 else
1191 }
1192 else
1193 /* Replace the current slot. */
1196 }
1198 /* Subroutines of finish_struct. */
1200 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1201 legit, otherwise return 0. */
1203 static int
1205 {
1206 tree elem;
1215 {
1217 {
1221 else
1224 }
1225 else
1226 {
1227 /* They're changing the access to the same thing they changed
1228 it to before. That's OK. */
1229 ;
1230 }
1231 }
1232 else
1233 {
1235 tf_warning_or_error);
1238 }
1240 }
1242 /* Process the USING_DECL, which is a member of T. */
1244 static void
1246 {
1249 tree access
1254 tree old_value;
1259 tf_warning_or_error);
1261 {
1267 else
1269 }
1277 ;
1279 {
1281 /* It's OK to use functions from a base when there are functions with
1283 else
1284 {
1289 }
1290 }
1292 {
1296 }
1298 /* Make type T see field decl FDECL with access ACCESS. */
1301 {
1304 }
1305 else
1307 }
1308 \f
1309 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1310 types with abi tags, add the corresponding identifiers to the VEC in
1311 *DATA and set IDENTIFIER_MARKED. */
1313 struct abi_tag_data
1314 {
1315 tree t;
1316 tree subob;
1317 };
1319 static tree
1321 {
1326 {
1330 {
1334 {
1336 {
1341 }
1342 else
1343 {
1350 }
1351 }
1352 }
1353 }
1355 }
1357 /* Check that class T has all the abi tags that subobject SUBOB has, or
1358 warn if not. */
1360 static void
1362 {
1365 {
1368 {
1372 }
1373 }
1381 {
1384 {
1388 }
1389 }
1390 }
1392 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1393 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1394 properties of the bases. */
1396 static void
1400 {
1404 tree base_binfo;
1405 tree binfo;
1415 {
1424 /* If any base class is non-literal, so is the derived class. */
1428 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1429 here because the case of virtual functions but non-virtual
1430 dtor is handled in finish_struct_1. */
1435 /* If the base class doesn't have copy constructors or
1436 assignment operators that take const references, then the
1437 derived class cannot have such a member automatically
1438 generated. */
1447 /* A virtual base does not effect nearly emptiness. */
1448 ;
1450 {
1452 /* And if there is more than one nearly empty base, then the
1453 derived class is not nearly empty either. */
1455 else
1456 /* Remember we've seen one. */
1458 }
1460 /* If the base class is not empty or nearly empty, then this
1461 class cannot be nearly empty. */
1464 /* A lot of properties from the bases also apply to the derived
1465 class. */
1483 /* A standard-layout class is a class that:
1484 ...
1485 * has no non-standard-layout base classes, */
1488 {
1489 tree basefield;
1490 /* ...has no base classes of the same type as the first non-static
1491 data member... */
1493 && (same_type_ignoring_top_level_qualifiers_p
1496 else
1497 /* ...either has no non-static data members in the most-derived
1498 class and at most one base class with non-static data
1499 members, or has no base classes with non-static data
1500 members */
1504 {
1507 else
1510 }
1511 }
1513 /* Don't bother collecting tm attributes if transactional memory
1514 support is not enabled. */
1516 {
1520 }
1523 }
1525 /* If one of the base classes had TM attributes, and the current class
1526 doesn't define its own, then the current class inherits one. */
1528 {
1531 }
1532 }
1534 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1535 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1536 that have had a nearly-empty virtual primary base stolen by some
1537 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1538 T. */
1540 static void
1542 {
1546 tree base_binfo;
1548 /* Determine the primary bases of our bases. */
1551 {
1554 /* See if we're the non-virtual primary of our inheritance
1555 chain. */
1557 {
1564 /* We are the primary binfo. */
1566 }
1567 /* Determine if we have a virtual primary base, and mark it so.
1568 */
1570 {
1574 /* Someone already claimed this base. */
1576 else
1577 {
1578 tree delta;
1583 /* A virtual binfo might have been copied from within
1584 another hierarchy. As we're about to use it as a
1585 primary base, make sure the offsets match. */
1593 }
1594 }
1595 }
1597 /* First look for a dynamic direct non-virtual base. */
1599 {
1603 {
1606 }
1607 }
1609 /* A "nearly-empty" virtual base class can be the primary base
1610 class, if no non-virtual polymorphic base can be found. Look for
1611 a nearly-empty virtual dynamic base that is not already a primary
1612 base of something in the hierarchy. If there is no such base,
1613 just pick the first nearly-empty virtual base. */
1619 {
1621 {
1622 /* Found one that is not primary. */
1625 }
1627 /* Remember the first candidate. */
1629 }
1631 found:
1632 /* If we've got a primary base, use it. */
1634 {
1639 /* We are stealing a primary base. */
1643 {
1644 tree delta;
1647 /* A virtual binfo might have been copied from within
1648 another hierarchy. As we're about to use it as a primary
1649 base, make sure the offsets match. */
1654 }
1661 }
1662 }
1664 /* Update the variant types of T. */
1666 void
1668 {
1669 tree variants;
1675 variants;
1677 {
1678 /* These fields are in the _TYPE part of the node, not in
1679 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1689 /* Copy whatever these are holding today. */
1693 }
1694 }
1696 /* Early variant fixups: we apply attributes at the beginning of the class
1697 definition, and we need to fix up any variants that have already been
1698 made via elaborated-type-specifier so that check_qualified_type works. */
1700 void
1702 {
1703 tree variants;
1709 variants;
1711 {
1712 /* These are the two fields that check_qualified_type looks at and
1713 are affected by attributes. */
1716 }
1717 }
1718 \f
1719 /* Set memoizing fields and bits of T (and its variants) for later
1720 use. */
1722 static void
1724 {
1725 /* Fix up variants (if any). */
1729 /* For a class w/o baseclasses, 'finish_struct' has set
1730 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1731 Similarly for a class whose base classes do not have vtables.
1732 When neither of these is true, we might have removed abstract
1733 virtuals (by providing a definition), added some (by declaring
1734 new ones), or redeclared ones from a base class. We need to
1735 recalculate what's really an abstract virtual at this point (by
1736 looking in the vtables). */
1739 /* If this type has a copy constructor or a destructor, force its
1740 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1741 nonzero. This will cause it to be passed by invisible reference
1742 and prevent it from being returned in a register. */
1745 {
1746 tree variants;
1749 {
1752 }
1753 }
1754 }
1756 /* Issue warnings about T having private constructors, but no friends,
1757 and so forth.
1759 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1760 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1761 non-private static member functions. */
1763 static void
1765 {
1768 tree fn;
1771 /* If the class has friends, those entities might create and
1772 access instances, so we should not warn. */
1775 /* We will have warned when the template was declared; there's
1776 no need to warn on every instantiation. */
1778 /* There's no reason to even consider warning about this
1779 class. */
1782 /* We only issue one warning, if more than one applies, because
1783 otherwise, on code like:
1785 class A {
1786 // Oops - forgot `public:'
1787 A();
1788 A(const A&);
1789 ~A();
1790 };
1792 we warn several times about essentially the same problem. */
1794 /* Check to see if all (non-constructor, non-destructor) member
1795 functions are private. (Since there are no friends or
1796 non-private statics, we can't ever call any of the private member
1797 functions.) */
1799 /* We're not interested in compiler-generated methods; they don't
1800 provide any way to call private members. */
1802 {
1804 {
1806 /* A non-private static member function is just like a
1807 friend; it can create and invoke private member
1808 functions, and be accessed without a class
1809 instance. */
1813 /* Keep searching for a static member function. */
1814 }
1817 }
1820 {
1821 /* There are no non-private methods, and there's at least one
1822 private member function that isn't a constructor or
1823 destructor. (If all the private members are
1824 constructors/destructors we want to use the code below that
1825 issues error messages specifically referring to
1826 constructors/destructors.) */
1832 {
1835 }
1837 {
1841 }
1842 }
1844 /* Even if some of the member functions are non-private, the class
1845 won't be useful for much if all the constructors or destructors
1846 are private: such an object can never be created or destroyed. */
1849 {
1852 t);
1854 }
1856 /* Warn about classes that have private constructors and no friends. */
1858 /* Implicitly generated constructors are always public. */
1861 {
1864 /* If a non-template class does not define a copy
1865 constructor, one is defined for it, enabling it to avoid
1866 this warning. For a template class, this does not
1867 happen, and so we would normally get a warning on:
1869 template <class T> class C { private: C(); };
1871 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1872 complete non-template or fully instantiated classes have this
1873 flag set. */
1876 else
1878 {
1880 /* Ideally, we wouldn't count copy constructors (or, in
1881 fact, any constructor that takes an argument of the
1882 class type as a parameter) because such things cannot
1883 be used to construct an instance of the class unless
1884 you already have one. But, for now at least, we're
1885 more generous. */
1887 {
1890 }
1891 }
1894 {
1897 t);
1899 }
1900 }
1901 }
1904 gt_pointer_operator new_value;
1908 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1910 static int
1912 {
1925 }
1927 /* This routine compares two fields like method_name_cmp but using the
1928 pointer operator in resort_field_decl_data. */
1930 static int
1932 {
1941 {
1948 }
1950 }
1952 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1954 void
1957 gt_pointer_operator new_value,
1959 {
1963 tree fn;
1965 /* The type conversion ops have to live at the front of the vec, so we
1966 can't sort them. */
1974 {
1978 resort_method_name_cmp);
1979 }
1980 }
1982 /* Warn about duplicate methods in fn_fields.
1984 Sort methods that are not special (i.e., constructors, destructors,
1985 and type conversion operators) so that we can find them faster in
1986 search. */
1988 static void
1990 {
1991 tree fn_fields;
2001 /* Clear DECL_IN_AGGR_P for all functions. */
2006 /* Issue warnings about private constructors and such. If there are
2007 no methods, then some public defaults are generated. */
2010 /* The type conversion ops have to live at the front of the vec, so we
2011 can't sort them. */
2020 }
2022 /* Make BINFO's vtable have N entries, including RTTI entries,
2023 vbase and vcall offsets, etc. Set its type and call the back end
2024 to lay it out. */
2026 static void
2028 {
2029 tree atype;
2030 tree vtable;
2035 /* We may have to grow the vtable. */
2038 {
2042 }
2043 }
2045 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2046 have the same signature. */
2048 int
2050 {
2051 /* One destructor overrides another if they are the same kind of
2052 destructor. */
2056 /* But a non-destructor never overrides a destructor, nor vice
2057 versa, nor do different kinds of destructors override
2058 one-another. For example, a complete object destructor does not
2059 override a deleting destructor. */
2068 {
2076 }
2078 }
2080 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2081 subobject. */
2083 static bool
2085 {
2086 tree probe;
2089 {
2093 /* If we meet a virtual base, we can't follow the inheritance
2094 any more. See if the complete type of DERIVED contains
2095 such a virtual base. */
2098 }
2100 }
2103 /* The function for which we are trying to find a final overrider. */
2104 tree fn;
2105 /* The base class in which the function was declared. */
2106 tree declaring_base;
2107 /* The candidate overriders. */
2108 tree candidates;
2109 /* Path to most derived. */
2113 /* Add the overrider along the current path to FFOD->CANDIDATES.
2114 Returns true if an overrider was found; false otherwise. */
2116 static bool
2120 {
2121 tree method;
2123 /* If BINFO is not the most derived type, try a more derived class.
2124 A definition there will overrider a definition here. */
2126 {
2127 depth--;
2131 }
2135 {
2138 /* Remove any candidates overridden by this new function. */
2140 {
2141 /* If *CANDIDATE overrides METHOD, then METHOD
2142 cannot override anything else on the list. */
2145 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2148 else
2150 }
2152 /* Add the new function. */
2155 }
2158 }
2160 /* Called from find_final_overrider via dfs_walk. */
2162 static tree
2164 {
2172 }
2174 static tree
2176 {
2181 }
2183 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2184 FN and whose TREE_VALUE is the binfo for the base where the
2185 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2186 DERIVED) is the base object in which FN is declared. */
2188 static tree
2190 {
2191 find_final_overrider_data ffod;
2193 /* Getting this right is a little tricky. This is valid:
2195 struct S { virtual void f (); };
2196 struct T { virtual void f (); };
2197 struct U : public S, public T { };
2199 even though calling `f' in `U' is ambiguous. But,
2201 struct R { virtual void f(); };
2202 struct S : virtual public R { virtual void f (); };
2203 struct T : virtual public R { virtual void f (); };
2204 struct U : public S, public T { };
2206 is not -- there's no way to decide whether to put `S::f' or
2207 `T::f' in the vtable for `R'.
2209 The solution is to look at all paths to BINFO. If we find
2210 different overriders along any two, then there is a problem. */
2214 /* Determine the depth of the hierarchy. */
2225 /* If there was no winner, issue an error message. */
2230 }
2232 /* Return the index of the vcall offset for FN when TYPE is used as a
2233 virtual base. */
2235 static tree
2237 {
2239 tree_pair_p p;
2247 /* There should always be an appropriate index. */
2249 }
2251 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2252 dominated by T. FN is the old function; VIRTUALS points to the
2253 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2254 of that entry in the list. */
2256 static void
2259 {
2260 tree b;
2261 tree overrider;
2262 tree delta;
2263 tree virtual_base;
2264 tree first_defn;
2270 /* Find the nearest primary base (possibly binfo itself) which defines
2271 this function; this is the class the caller will convert to when
2272 calling FN through BINFO. */
2274 {
2279 /* The nearest definition is from a lost primary. */
2282 }
2285 /* Find the final overrider. */
2288 {
2291 }
2294 /* Check for adjusting covariant return types. */
2302 /* If the overrider is invalid, don't even try. */
2304 {
2305 /* If FN is a covariant thunk, we must figure out the adjustment
2306 to the final base FN was converting to. As OVERRIDER_TARGET might
2307 also be converting to the return type of FN, we have to
2308 combine the two conversions here. */
2315 {
2319 }
2320 else
2324 /* Find the equivalent binfo within the return type of the
2325 overriding function. We will want the vbase offset from
2326 there. */
2328 over_return);
2331 {
2332 /* There was no existing virtual thunk (which takes
2333 precedence). So find the binfo of the base function's
2334 return type within the overriding function's return type.
2335 We cannot call lookup base here, because we're inside a
2336 dfs_walk, and will therefore clobber the BINFO_MARKED
2337 flags. Fortunately we know the covariancy is valid (it
2338 has already been checked), so we can just iterate along
2339 the binfos, which have been chained in inheritance graph
2340 order. Of course it is lame that we have to repeat the
2341 search here anyway -- we should really be caching pieces
2342 of the vtable and avoiding this repeated work. */
2345 /* Find the base binfo within the overriding function's
2346 return type. We will always find a thunk_binfo, except
2347 when the covariancy is invalid (which we will have
2348 already diagnosed). */
2351 thunk_binfo;
2357 /* See if virtual inheritance is involved. */
2359 virtual_offset;
2366 {
2370 {
2371 /* We convert via virtual base. Adjust the fixed
2372 offset to be from there. */
2373 offset =
2377 }
2379 /* There was an existing fixed offset, this must be
2380 from the base just converted to, and the base the
2381 FN was thunking to. */
2383 else
2385 }
2386 }
2389 /* Replace the overriding function with a covariant thunk. We
2390 will emit the overriding function in its own slot as
2391 well. */
2394 }
2395 else
2399 /* If we need a covariant thunk, then we may need to adjust first_defn.
2400 The ABI specifies that the thunks emitted with a function are
2401 determined by which bases the function overrides, so we need to be
2402 sure that we're using a thunk for some overridden base; even if we
2403 know that the necessary this adjustment is zero, there may not be an
2404 appropriate zero-this-adjusment thunk for us to use since thunks for
2405 overriding virtual bases always use the vcall offset.
2407 Furthermore, just choosing any base that overrides this function isn't
2408 quite right, as this slot won't be used for calls through a type that
2409 puts a covariant thunk here. Calling the function through such a type
2410 will use a different slot, and that slot is the one that determines
2411 the thunk emitted for that base.
2413 So, keep looking until we find the base that we're really overriding
2414 in this slot: the nearest primary base that doesn't use a covariant
2415 thunk in this slot. */
2417 {
2419 /* We already know that the overrider needs a covariant thunk. */
2422 {
2429 }
2431 }
2433 /* Assume that we will produce a thunk that convert all the way to
2434 the final overrider, and not to an intermediate virtual base. */
2437 /* See if we can convert to an intermediate virtual base first, and then
2438 use the vcall offset located there to finish the conversion. */
2440 {
2441 /* If we find the final overrider, then we can stop
2442 walking. */
2447 /* If we find a virtual base, and we haven't yet found the
2448 overrider, then there is a virtual base between the
2449 declaring base (first_defn) and the final overrider. */
2451 {
2454 }
2455 }
2457 /* Compute the constant adjustment to the `this' pointer. The
2458 `this' pointer, when this function is called, will point at BINFO
2459 (or one of its primary bases, which are at the same offset). */
2461 /* The `this' pointer needs to be adjusted from the declaration to
2462 the nearest virtual base. */
2467 /* If the nearest definition is in a lost primary, we don't need an
2468 entry in our vtable. Except possibly in a constructor vtable,
2469 if we happen to get our primary back. In that case, the offset
2470 will be zero, as it will be a primary base. */
2472 else
2473 /* The `this' pointer needs to be adjusted from pointing to
2474 BINFO to pointing at the base where the final overrider
2475 appears. */
2486 else
2490 }
2492 /* Called from modify_all_vtables via dfs_walk. */
2494 static tree
2496 {
2498 tree virtuals;
2499 tree old_virtuals;
2503 /* A base without a vtable needs no modification, and its bases
2504 are uninteresting. */
2509 /* Don't do the primary vtable, if it's new. */
2513 /* There's no need to modify the vtable for a non-virtual primary
2514 base; we're not going to use that vtable anyhow. We do still
2515 need to do this for virtual primary bases, as they could become
2516 non-primary in a construction vtable. */
2521 /* Now, go through each of the virtual functions in the virtual
2522 function table for BINFO. Find the final overrider, and update
2523 the BINFO_VIRTUALS list appropriately. */
2526 virtuals;
2530 binfo,
2535 }
2537 /* Update all of the primary and secondary vtables for T. Create new
2538 vtables as required, and initialize their RTTI information. Each
2539 of the functions in VIRTUALS is declared in T and may override a
2540 virtual function from a base class; find and modify the appropriate
2541 entries to point to the overriding functions. Returns a list, in
2542 declaration order, of the virtual functions that are declared in T,
2543 but do not appear in the primary base class vtable, and which
2544 should therefore be appended to the end of the vtable for T. */
2546 static tree
2548 {
2552 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2556 /* Update all of the vtables. */
2559 /* Add virtual functions not already in our primary vtable. These
2560 will be both those introduced by this class, and those overridden
2561 from secondary bases. It does not include virtuals merely
2562 inherited from secondary bases. */
2564 {
2569 {
2570 /* We don't need to adjust the `this' pointer when
2571 calling this function. */
2575 /* This is a function not already in our vtable. Keep it. */
2577 }
2578 else
2579 /* We've already got an entry for this function. Skip it. */
2581 }
2584 }
2586 /* Get the base virtual function declarations in T that have the
2587 indicated NAME. */
2589 static tree
2591 {
2592 tree methods;
2597 /* Find virtual functions in T with the indicated NAME. */
2601 methods;
2603 {
2609 }
2615 {
2618 base_fndecls);
2619 }
2622 }
2624 /* If this declaration supersedes the declaration of
2625 a method declared virtual in the base class, then
2626 mark this field as being virtual as well. */
2628 void
2630 {
2633 /* In [temp.mem] we have:
2635 A specialization of a member function template does not
2636 override a virtual function from a base class. */
2643 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2644 the error_mark_node so that we know it is an overriding
2645 function. */
2646 {
2649 }
2652 {
2658 }
2663 }
2665 /* Warn about hidden virtual functions that are not overridden in t.
2666 We know that constructors and destructors don't apply. */
2668 static void
2670 {
2672 tree fns;
2675 /* We go through each separately named virtual function. */
2679 {
2680 tree fn;
2681 tree name;
2682 tree fndecl;
2683 tree base_fndecls;
2684 tree base_binfo;
2685 tree binfo;
2688 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2689 have the same name. Figure out what name that is. */
2691 /* There are no possibly hidden functions yet. */
2693 /* Iterate through all of the base classes looking for possibly
2694 hidden functions. */
2697 {
2700 base_fndecls);
2701 }
2703 /* If there are no functions to hide, continue. */
2707 /* Remove any overridden functions. */
2709 {
2712 {
2716 /* If the method from the base class has the same
2717 signature as the method from the derived class, it
2718 has been overridden. */
2721 else
2723 }
2724 }
2726 /* Now give a warning for all base functions without overriders,
2727 as they are hidden. */
2729 {
2730 /* Here we know it is a hider, and no overrider exists. */
2734 }
2735 }
2736 }
2738 /* Check for things that are invalid. There are probably plenty of other
2739 things we should check for also. */
2741 static void
2743 {
2744 tree field;
2747 {
2755 {
2759 {
2760 /* We're generally only interested in entities the user
2761 declared, but we also find nested classes by noticing
2762 the TYPE_DECL that we create implicitly. You're
2763 allowed to put one anonymous union inside another,
2764 though, so we explicitly tolerate that. We use
2765 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2766 we also allow unnamed types used for defining fields. */
2773 {
2777 else
2781 }
2784 {
2787 else
2789 }
2791 {
2794 else
2796 }
2800 }
2801 }
2802 }
2803 }
2805 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2806 will be used later during class template instantiation.
2807 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2808 a non-static member data (FIELD_DECL), a member function
2809 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2810 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2811 When FRIEND_P is nonzero, T is either a friend class
2812 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2813 (FUNCTION_DECL, TEMPLATE_DECL). */
2815 void
2817 {
2818 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2823 }
2825 /* This function is called from declare_virt_assop_and_dtor via
2826 dfs_walk_all.
2828 DATA is a type that direcly or indirectly inherits the base
2829 represented by BINFO. If BINFO contains a virtual assignment [copy
2830 assignment or move assigment] operator or a virtual constructor,
2831 declare that function in DATA if it hasn't been already declared. */
2833 static tree
2835 {
2843 /* A base without a vtable needs no modification, and its bases
2844 are uninteresting. */
2848 /* If this is a primary base, then we have already looked at the
2849 virtual functions of its vtable. */
2853 {
2857 {
2862 }
2866 }
2869 }
2871 /* If the class type T has a direct or indirect base that contains a
2872 virtual assignment operator or a virtual destructor, declare that
2873 function in T if it hasn't been already declared. */
2875 static void
2877 {
2885 dfs_declare_virt_assop_and_dtor,
2887 }
2889 /* Declare the inheriting constructor for class T inherited from base
2890 constructor CTOR with the parameter array PARMS of size NPARMS. */
2892 static void
2894 {
2895 /* We don't declare an inheriting ctor that would be a default,
2896 copy or move ctor for derived or base. */
2901 {
2905 }
2913 {
2916 }
2917 }
2919 /* Declare all the inheriting constructors for class T inherited from base
2920 constructor CTOR. */
2922 static void
2924 {
2930 {
2934 }
2937 {
2941 }
2942 }
2944 /* Create default constructors, assignment operators, and so forth for
2945 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2946 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2947 the class cannot have a default constructor, copy constructor
2948 taking a const reference argument, or an assignment operator taking
2949 a const reference, respectively. */
2951 static void
2955 {
2963 /* Destructor. */
2965 {
2966 /* In general, we create destructors lazily. */
2971 /* But if this is a Java class, any non-trivial destructor is
2972 invalid, even if compiler-generated. Therefore, if the
2973 destructor is non-trivial we create it now. */
2975 }
2977 /* [class.ctor]
2979 If there is no user-declared constructor for a class, a default
2980 constructor is implicitly declared. */
2982 {
2987 /* This might force the declaration. */
2989 }
2991 /* [class.ctor]
2993 If a class definition does not explicitly declare a copy
2994 constructor, one is declared implicitly. */
2996 {
3002 }
3004 /* If there is no assignment operator, one will be created if and
3005 when it is needed. For now, just record whether or not the type
3006 of the parameter to the assignment operator will be a const or
3007 non-const reference. */
3009 {
3015 }
3017 /* We can't be lazy about declaring functions that might override
3018 a virtual function from a base class. */
3022 {
3026 {
3027 /* declare, then remove the decl */
3036 }
3037 else
3039 }
3040 }
3042 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3043 count the number of fields in TYPE, including anonymous union
3044 members. */
3046 static int
3048 {
3049 tree x;
3052 {
3055 else
3057 }
3059 }
3061 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3062 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3063 elts, starting at offset IDX. */
3065 static int
3067 {
3068 tree x;
3070 {
3073 else
3075 }
3077 }
3079 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3080 starting at offset IDX. */
3082 static int
3086 {
3087 tree values;
3091 }
3093 /* FIELD is a bit-field. We are finishing the processing for its
3094 enclosing type. Issue any appropriate messages and set appropriate
3095 flags. Returns false if an error has been diagnosed. */
3097 static bool
3099 {
3101 tree w;
3103 /* Extract the declared width of the bitfield, which has been
3104 temporarily stashed in DECL_INITIAL. */
3107 /* Remove the bit-field width indicator so that the rest of the
3108 compiler does not treat that value as an initializer. */
3111 /* Detect invalid bit-field type. */
3113 {
3116 }
3117 else
3118 {
3120 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3123 /* detect invalid field size. */
3129 {
3132 }
3134 {
3137 }
3139 {
3142 }
3151 }
3154 {
3158 }
3159 else
3160 {
3161 /* Non-bit-fields are aligned for their type. */
3165 }
3166 }
3168 /* FIELD is a non bit-field. We are finishing the processing for its
3169 enclosing type T. Issue any appropriate messages and set appropriate
3170 flags. */
3172 static void
3174 tree t,
3178 {
3181 /* In C++98 an anonymous union cannot contain any fields which would change
3182 the settings of CANT_HAVE_CONST_CTOR and friends. */
3184 ;
3185 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3186 structs. So, we recurse through their fields here. */
3188 {
3189 tree fields;
3195 }
3196 /* Check members with class type for constructors, destructors,
3197 etc. */
3199 {
3200 /* Never let anything with uninheritable virtuals
3201 make it through without complaint. */
3205 {
3210 field);
3215 field);
3217 {
3221 }
3222 }
3223 else
3224 {
3237 }
3246 }
3251 {
3252 /* `build_class_init_list' does not recognize
3253 non-FIELD_DECLs. */
3257 }
3258 }
3260 /* Check the data members (both static and non-static), class-scoped
3261 typedefs, etc., appearing in the declaration of T. Issue
3262 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3263 declaration order) of access declarations; each TREE_VALUE in this
3264 list is a USING_DECL.
3266 In addition, set the following flags:
3268 EMPTY_P
3269 The class is empty, i.e., contains no non-static data members.
3271 CANT_HAVE_CONST_CTOR_P
3272 This class cannot have an implicitly generated copy constructor
3273 taking a const reference.
3275 CANT_HAVE_CONST_ASN_REF
3276 This class cannot have an implicitly generated assignment
3277 operator taking a const reference.
3279 All of these flags should be initialized before calling this
3280 function.
3282 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3283 fields can be added by adding to this chain. */
3285 static void
3289 {
3297 /* Assume there are no access declarations. */
3299 /* Assume this class has no pointer members. */
3301 /* Assume none of the members of this class have default
3302 initializations. */
3306 {
3314 {
3315 /* Save the access declarations for our caller. */
3318 }
3324 /* If we've gotten this far, it's a data member, possibly static,
3325 or an enumerator. */
3329 /* When this goes into scope, it will be a non-local reference. */
3333 {
3334 /* [class.union]
3336 If a union contains a static data member, or a member of
3337 reference type, the program is ill-formed. */
3339 {
3342 }
3344 {
3349 }
3350 }
3352 /* Perform error checking that did not get done in
3353 grokdeclarator. */
3355 {
3359 }
3361 {
3365 }
3373 /* Now it can only be a FIELD_DECL. */
3378 /* If at least one non-static data member is non-literal, the whole
3379 class becomes non-literal. Note: if the type is incomplete we
3380 will complain later on. */
3384 /* A standard-layout class is a class that:
3385 ...
3386 has the same access control (Clause 11) for all non-static data members,
3387 ... */
3394 /* If this is of reference type, check if it needs an init. */
3396 {
3402 /* ARM $12.6.2: [A member initializer list] (or, for an
3403 aggregate, initialization by a brace-enclosed list) is the
3404 only way to initialize nonstatic const and reference
3405 members. */
3408 }
3413 {
3415 {
3416 warning
3419 x);
3421 }
3425 }
3428 /* We don't treat zero-width bitfields as making a class
3429 non-empty. */
3430 ;
3431 else
3432 {
3433 /* The class is non-empty. */
3435 /* The class is not even nearly empty. */
3437 /* If one of the data members contains an empty class,
3438 so does T. */
3442 }
3444 /* This is used by -Weffc++ (see below). Warn only for pointers
3445 to members which might hold dynamic memory. So do not warn
3446 for pointers to functions or pointers to members. */
3452 {
3457 }
3463 /* DR 148 now allows pointers to members (which are POD themselves),
3464 to be allowed in POD structs. */
3473 /* We set DECL_C_BIT_FIELD in grokbitfield.
3474 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3477 cant_have_const_ctor_p,
3478 no_const_asn_ref_p,
3481 /* Now that we've removed bit-field widths from DECL_INITIAL,
3482 anything left in DECL_INITIAL is an NSDMI that makes the class
3483 non-aggregate. */
3487 /* If any field is const, the structure type is pseudo-const. */
3489 {
3494 /* ARM $12.6.2: [A member initializer list] (or, for an
3495 aggregate, initialization by a brace-enclosed list) is the
3496 only way to initialize nonstatic const and reference
3497 members. */
3500 }
3501 /* A field that is pseudo-const makes the structure likewise. */
3503 {
3508 }
3510 /* Core issue 80: A nonstatic data member is required to have a
3511 different name from the class iff the class has a
3512 user-declared constructor. */
3516 }
3518 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3519 it should also define a copy constructor and an assignment operator to
3520 implement the correct copy semantic (deep vs shallow, etc.). As it is
3521 not feasible to check whether the constructors do allocate dynamic memory
3522 and store it within members, we approximate the warning like this:
3524 -- Warn only if there are members which are pointers
3525 -- Warn only if there is a non-trivial constructor (otherwise,
3526 there cannot be memory allocated).
3527 -- Warn only if there is a non-trivial destructor. We assume that the
3528 user at least implemented the cleanup correctly, and a destructor
3529 is needed to free dynamic memory.
3531 This seems enough for practical purposes. */
3533 && has_pointers
3537 {
3541 {
3546 }
3550 }
3552 /* Non-static data member initializers make the default constructor
3553 non-trivial. */
3555 {
3558 }
3560 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3564 /* Check anonymous struct/anonymous union fields. */
3567 /* We've built up the list of access declarations in reverse order.
3568 Fix that now. */
3570 }
3572 /* If TYPE is an empty class type, records its OFFSET in the table of
3573 OFFSETS. */
3575 static int
3577 {
3578 splay_tree_node n;
3583 /* Record the location of this empty object in OFFSETS. */
3591 type,
3595 }
3597 /* Returns nonzero if TYPE is an empty class type and there is
3598 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3600 static int
3602 {
3603 splay_tree_node n;
3604 tree t;
3609 /* Record the location of this empty object in OFFSETS. */
3619 }
3621 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3622 F for every subobject, passing it the type, offset, and table of
3623 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3624 be traversed.
3626 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3627 than MAX_OFFSET will not be walked.
3629 If F returns a nonzero value, the traversal ceases, and that value
3630 is returned. Otherwise, returns zero. */
3632 static int
3634 subobject_offset_fn f,
3635 tree offset,
3636 splay_tree offsets,
3637 tree max_offset,
3639 {
3643 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3644 stop. */
3652 {
3656 }
3659 {
3660 tree field;
3661 tree binfo;
3664 /* Avoid recursing into objects that are not interesting. */
3668 /* Record the location of TYPE. */
3673 /* Iterate through the direct base classes of TYPE. */
3677 {
3678 tree binfo_offset;
3691 offset,
3693 else
3694 {
3695 tree orig_binfo;
3696 /* We cannot rely on BINFO_OFFSET being set for the base
3697 class yet, but the offsets for direct non-virtual
3698 bases can be calculated by going back to the TYPE. */
3701 offset,
3703 }
3706 f,
3707 binfo_offset,
3708 offsets,
3709 max_offset,
3714 }
3717 {
3721 /* Iterate through the virtual base classes of TYPE. In G++
3722 3.2, we included virtual bases in the direct base class
3723 loop above, which results in incorrect results; the
3724 correct offsets for virtual bases are only known when
3725 working with the most derived type. */
3729 {
3731 f,
3733 offset,
3735 offsets,
3736 max_offset,
3740 }
3741 else
3742 {
3743 /* We still have to walk the primary base, if it is
3744 virtual. (If it is non-virtual, then it was walked
3745 above.) */
3751 {
3752 r = (walk_subobject_offsets
3757 }
3758 }
3759 }
3761 /* Iterate through the fields of TYPE. */
3764 {
3765 tree field_offset;
3769 else
3770 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3774 f,
3776 offset,
3777 field_offset),
3778 offsets,
3779 max_offset,
3783 }
3784 }
3786 {
3789 tree index;
3791 /* Avoid recursing into objects that are not interesting. */
3796 /* Step through each of the elements in the array. */
3798 /* G++ 3.2 had an off-by-one error here. */
3803 {
3805 f,
3806 offset,
3807 offsets,
3808 max_offset,
3814 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3815 there's no point in iterating through the remaining
3816 elements of the array. */
3819 }
3820 }
3823 }
3825 /* Record all of the empty subobjects of TYPE (either a type or a
3826 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3827 is being placed at OFFSET; otherwise, it is a base class that is
3828 being placed at OFFSET. */
3830 static void
3832 tree offset,
3833 splay_tree offsets,
3835 {
3836 tree max_offset;
3837 /* If recording subobjects for a non-static data member or a
3838 non-empty base class , we do not need to record offsets beyond
3839 the size of the biggest empty class. Additional data members
3840 will go at the end of the class. Additional base classes will go
3841 either at offset zero (if empty, in which case they cannot
3842 overlap with offsets past the size of the biggest empty class) or
3843 at the end of the class.
3845 However, if we are placing an empty base class, then we must record
3846 all offsets, as either the empty class is at offset zero (where
3847 other empty classes might later be placed) or at the end of the
3848 class (where other objects might then be placed, so other empty
3849 subobjects might later overlap). */
3853 else
3857 }
3859 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3860 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3861 virtual bases of TYPE are examined. */
3863 static int
3865 tree offset,
3866 splay_tree offsets,
3868 {
3869 splay_tree_node max_node;
3871 /* Get the node in OFFSETS that indicates the maximum offset where
3872 an empty subobject is located. */
3874 /* If there aren't any empty subobjects, then there's no point in
3875 performing this check. */
3881 vbases_p);
3882 }
3884 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3885 non-static data member of the type indicated by RLI. BINFO is the
3886 binfo corresponding to the base subobject, OFFSETS maps offsets to
3887 types already located at those offsets. This function determines
3888 the position of the DECL. */
3890 static void
3892 tree decl,
3893 tree binfo,
3894 splay_tree offsets)
3895 {
3898 tree type;
3901 {
3902 /* For the purposes of determining layout conflicts, we want to
3903 use the class type of BINFO; TREE_TYPE (DECL) will be the
3904 CLASSTYPE_AS_BASE version, which does not contain entries for
3905 zero-sized bases. */
3908 }
3909 else
3910 {
3913 }
3915 /* Try to place the field. It may take more than one try if we have
3916 a hard time placing the field without putting two objects of the
3917 same type at the same address. */
3919 {
3922 /* Place this field. */
3926 /* We have to check to see whether or not there is already
3927 something of the same type at the offset we're about to use.
3928 For example, consider:
3930 struct S {};
3931 struct T : public S { int i; };
3932 struct U : public S, public T {};
3934 Here, we put S at offset zero in U. Then, we can't put T at
3935 offset zero -- its S component would be at the same address
3936 as the S we already allocated. So, we have to skip ahead.
3937 Since all data members, including those whose type is an
3938 empty class, have nonzero size, any overlap can happen only
3939 with a direct or indirect base-class -- it can't happen with
3940 a data member. */
3941 /* In a union, overlap is permitted; all members are placed at
3942 offset zero. */
3945 /* G++ 3.2 did not check for overlaps when placing a non-empty
3946 virtual base. */
3951 {
3952 /* Strip off the size allocated to this field. That puts us
3953 at the first place we could have put the field with
3954 proper alignment. */
3957 /* Bump up by the alignment required for the type. */
3958 rli->bitpos
3964 }
3965 else
3966 /* There was no conflict. We're done laying out this field. */
3968 }
3970 /* Now that we know where it will be placed, update its
3971 BINFO_OFFSET. */
3973 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3974 this point because their BINFO_OFFSET is copied from another
3975 hierarchy. Therefore, we may not need to add the entire
3976 OFFSET. */
3982 }
3984 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3986 static int
3988 tree offset,
3990 {
3992 }
3994 /* Layout the empty base BINFO. EOC indicates the byte currently just
3995 past the end of the class, and should be correctly aligned for a
3996 class of the type indicated by BINFO; OFFSETS gives the offsets of
3997 the empty bases allocated so far. T is the most derived
3998 type. Return nonzero iff we added it at the end. */
4000 static bool
4003 {
4004 tree alignment;
4008 /* This routine should only be used for empty classes. */
4013 {
4015 propagate_binfo_offsets
4018 else
4020 "offset of empty base %qT may not be ABI-compliant and may"
4023 }
4025 /* This is an empty base class. We first try to put it at offset
4026 zero. */
4029 offsets,
4031 {
4032 /* That didn't work. Now, we move forward from the next
4033 available spot in the class. */
4037 {
4040 offsets,
4042 /* We finally found a spot where there's no overlap. */
4045 /* There's overlap here, too. Bump along to the next spot. */
4047 }
4048 }
4051 {
4056 }
4059 }
4061 /* Layout the base given by BINFO in the class indicated by RLI.
4062 *BASE_ALIGN is a running maximum of the alignments of
4063 any base class. OFFSETS gives the location of empty base
4064 subobjects. T is the most derived type. Return nonzero if the new
4065 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4066 *NEXT_FIELD, unless BINFO is for an empty base class.
4068 Returns the location at which the next field should be inserted. */
4073 {
4078 /* This error is now reported in xref_tag, thus giving better
4079 location information. */
4082 /* Place the base class. */
4084 {
4085 tree decl;
4087 /* The containing class is non-empty because it has a non-empty
4088 base class. */
4091 /* Create the FIELD_DECL. */
4098 {
4106 /* Try to place the field. It may take more than one try if we
4107 have a hard time placing the field without putting two
4108 objects of the same type at the same address. */
4110 /* Add the new FIELD_DECL to the list of fields for T. */
4114 }
4115 }
4116 else
4117 {
4118 tree eoc;
4121 /* On some platforms (ARM), even empty classes will not be
4122 byte-aligned. */
4127 /* A nearly-empty class "has no proper base class that is empty,
4128 not morally virtual, and at an offset other than zero." */
4130 {
4133 /* The check above (used in G++ 3.2) is insufficient because
4134 an empty class placed at offset zero might itself have an
4135 empty base at a nonzero offset. */
4137 empty_base_at_nonzero_offset_p,
4138 size_zero_node,
4142 {
4145 else
4147 "class %qT will be considered nearly empty in a "
4149 }
4150 }
4152 /* We do not create a FIELD_DECL for empty base classes because
4153 it might overlap some other field. We want to be able to
4154 create CONSTRUCTORs for the class by iterating over the
4155 FIELD_DECLs, and the back end does not handle overlapping
4156 FIELD_DECLs. */
4158 /* An empty virtual base causes a class to be non-empty
4159 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4160 here because that was already done when the virtual table
4161 pointer was created. */
4162 }
4164 /* Record the offsets of BINFO and its base subobjects. */
4167 offsets,
4171 }
4173 /* Layout all of the non-virtual base classes. Record empty
4174 subobjects in OFFSETS. T is the most derived type. Return nonzero
4175 if the type cannot be nearly empty. The fields created
4176 corresponding to the base classes will be inserted at
4177 *NEXT_FIELD. */
4179 static void
4182 {
4183 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4184 subobjects. */
4189 /* The primary base class is always allocated first. */
4194 /* Now allocate the rest of the bases. */
4196 {
4197 tree base_binfo;
4201 /* The primary base was already allocated above, so we don't
4202 need to allocate it again here. */
4206 /* Virtual bases are added at the end (a primary virtual base
4207 will have already been added). */
4213 }
4214 }
4216 /* Go through the TYPE_METHODS of T issuing any appropriate
4217 diagnostics, figuring out which methods override which other
4218 methods, and so forth. */
4220 static void
4222 {
4223 tree x;
4226 {
4230 /* The name of the field is the original field name
4231 Save this in auxiliary field for later overloading. */
4233 {
4237 }
4238 /* All user-provided destructors are non-trivial.
4239 Constructors and assignment ops are handled in
4240 grok_special_member_properties. */
4243 }
4244 }
4246 /* FN is a constructor or destructor. Clone the declaration to create
4247 a specialized in-charge or not-in-charge version, as indicated by
4248 NAME. */
4250 static tree
4252 {
4253 tree parms;
4254 tree clone;
4256 /* Copy the function. */
4258 /* Reset the function name. */
4261 /* Remember where this function came from. */
4263 /* Make it easy to find the CLONE given the FN. */
4267 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4269 {
4276 }
4279 /* There's no pending inline data for this function. */
4283 /* The base-class destructor is not virtual. */
4285 {
4289 }
4291 /* If there was an in-charge parameter, drop it from the function
4292 type. */
4294 {
4295 tree basetype;
4296 tree parmtypes;
4297 tree exceptions;
4302 /* Skip the `this' parameter. */
4304 /* Skip the in-charge parameter. */
4306 /* And the VTT parm, in a complete [cd]tor. */
4310 /* If this is subobject constructor or destructor, add the vtt
4311 parameter. */
4315 parmtypes);
4318 exceptions);
4322 }
4324 /* Copy the function parameters. */
4326 /* Remove the in-charge parameter. */
4328 {
4332 }
4333 /* And the VTT parm, in a complete [cd]tor. */
4335 {
4338 else
4339 {
4343 }
4344 }
4347 {
4350 }
4352 /* Create the RTL for this function. */
4360 }
4362 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4363 not invoke this function directly.
4365 For a non-thunk function, returns the address of the slot for storing
4366 the function it is a clone of. Otherwise returns NULL_TREE.
4368 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4369 cloned_function is unset. This is to support the separate
4370 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4371 on a template makes sense, but not the former. */
4373 tree *
4375 {
4383 {
4384 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4387 else
4388 #endif
4390 }
4395 else
4397 }
4399 /* Produce declarations for all appropriate clones of FN. If
4400 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4401 CLASTYPE_METHOD_VEC as well. */
4403 void
4405 {
4406 tree clone;
4408 /* Avoid inappropriate cloning. */
4414 {
4415 /* For each constructor, we need two variants: an in-charge version
4416 and a not-in-charge version. */
4423 }
4424 else
4425 {
4428 /* For each destructor, we need three variants: an in-charge
4429 version, a not-in-charge version, and an in-charge deleting
4430 version. We clone the deleting version first because that
4431 means it will go second on the TYPE_METHODS list -- and that
4432 corresponds to the correct layout order in the virtual
4433 function table.
4435 For a non-virtual destructor, we do not build a deleting
4436 destructor. */
4438 {
4442 }
4449 }
4451 /* Note that this is an abstract function that is never emitted. */
4453 }
4455 /* DECL is an in charge constructor, which is being defined. This will
4456 have had an in class declaration, from whence clones were
4457 declared. An out-of-class definition can specify additional default
4458 arguments. As it is the clones that are involved in overload
4459 resolution, we must propagate the information from the DECL to its
4460 clones. */
4462 void
4464 {
4465 tree clone;
4469 {
4476 /* Skip the 'this' parameter. */
4492 {
4497 {
4498 /* A default parameter has been added. Adjust the
4499 clone's parameters. */
4503 tree type;
4508 {
4511 clone_parms);
4513 }
4516 clone_parms);
4525 }
4526 }
4528 }
4529 }
4531 /* For each of the constructors and destructors in T, create an
4532 in-charge and not-in-charge variant. */
4534 static void
4536 {
4537 tree fns;
4539 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4540 out now. */
4548 }
4550 /* Deduce noexcept for a destructor DTOR. */
4552 void
4554 {
4556 {
4563 }
4564 }
4566 /* For each destructor in T, deduce noexcept:
4568 12.4/3: A declaration of a destructor that does not have an
4569 exception-specification is implicitly considered to have the
4570 same exception-specification as an implicit declaration (15.4). */
4572 static void
4574 {
4575 tree fns;
4577 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4578 out now. */
4584 }
4586 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4587 of TYPE for virtual functions which FNDECL overrides. Return a
4588 mask of the tm attributes found therein. */
4590 static int
4592 {
4594 tree base_binfo;
4598 {
4608 else
4610 }
4613 }
4615 /* Subroutine of set_method_tm_attributes. Handle the checks and
4616 inheritance for one virtual method FNDECL. */
4618 static void
4620 {
4621 tree tm_attr;
4626 /* If FNDECL doesn't actually override anything (i.e. T is the
4627 class that first declares FNDECL virtual), then we're done. */
4634 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4635 tm_pure must match exactly, otherwise no weakening of
4636 tm_safe > tm_callable > nothing. */
4637 /* ??? The tm_pure attribute didn't make the transition to the
4638 multivendor language spec. */
4640 {
4642 {
4645 }
4646 }
4647 /* If the overridden function is tm_pure, then FNDECL must be. */
4650 /* Look for base class combinations that cannot be satisfied. */
4652 {
4658 }
4659 /* If FNDECL did not declare an attribute, then inherit the most
4660 restrictive one. */
4662 {
4664 }
4665 /* Otherwise validate that we're not weaker than a function
4666 that is being overridden. */
4667 else
4668 {
4672 }
4675 err_override:
4679 }
4681 /* For each of the methods in T, propagate a class-level tm attribute. */
4683 static void
4685 {
4688 /* Don't bother collecting tm attributes if transactional memory
4689 support is not enabled. */
4693 /* Process virtual methods first, as they inherit directly from the
4694 base virtual function and also require validation of new attributes. */
4696 {
4697 tree vchain;
4700 {
4705 }
4706 }
4708 /* If the class doesn't have an attribute, nothing more to do. */
4713 /* Any method that does not yet have a tm attribute inherits
4714 the one from the class. */
4716 {
4719 }
4720 }
4722 /* Returns true iff class T has a user-defined constructor other than
4723 the default constructor. */
4725 bool
4727 {
4728 tree fns;
4734 {
4741 }
4744 }
4746 /* Returns the defaulted constructor if T has one. Otherwise, returns
4747 NULL_TREE. */
4749 tree
4751 {
4758 {
4762 {
4768 }
4769 }
4772 }
4774 /* Returns true iff FN is a user-provided function, i.e. user-declared
4775 and not defaulted at its first declaration; or explicit, private,
4776 protected, or non-const. */
4778 bool
4780 {
4783 else
4786 }
4788 /* Returns true iff class T has a user-provided constructor. */
4790 bool
4792 {
4793 tree fns;
4801 /* This can happen in error cases; avoid crashing. */
4810 }
4812 /* Returns true iff class T has a user-provided default constructor. */
4814 bool
4816 {
4817 tree fns;
4823 {
4829 }
4832 }
4834 /* If default-initialization leaves part of TYPE uninitialized, returns
4835 a DECL for the field or TYPE itself (DR 253). */
4837 tree
4839 {
4850 {
4854 }
4859 {
4863 }
4866 }
4868 /* Returns true iff for class T, a trivial synthesized default constructor
4869 would be constexpr. */
4871 bool
4873 {
4874 /* A defaulted trivial default constructor is constexpr
4875 if there is nothing to initialize. */
4878 }
4880 /* Returns true iff class T has a constexpr default constructor. */
4882 bool
4884 {
4885 tree fns;
4888 {
4889 /* The caller should have stripped an enclosing array. */
4892 }
4894 {
4897 /* Non-trivial, we need to check subobject constructors. */
4899 }
4902 }
4904 /* Returns true iff class TYPE has a virtual destructor. */
4906 bool
4908 {
4909 tree dtor;
4917 }
4919 /* Returns true iff class T has a move constructor. */
4921 bool
4923 {
4924 tree fns;
4927 {
4930 }
4940 }
4942 /* Returns true iff class T has a move assignment operator. */
4944 bool
4946 {
4947 tree fns;
4950 {
4953 }
4961 }
4963 /* Returns true iff class T has a move constructor that was explicitly
4964 declared in the class body. Note that this is different from
4965 "user-provided", which doesn't include functions that are defaulted in
4966 the class. */
4968 bool
4970 {
4971 tree fns;
4980 {
4984 }
4987 }
4989 /* Returns true iff class T has a move assignment operator that was
4990 explicitly declared in the class body. */
4992 bool
4994 {
4995 tree fns;
5002 {
5006 }
5009 }
5011 /* Nonzero if we need to build up a constructor call when initializing an
5012 object of this class, either because it has a user-provided constructor
5013 or because it doesn't have a default constructor (so we need to give an
5014 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5015 what you care about is whether or not an object can be produced by a
5016 constructor (e.g. so we don't set TREE_READONLY on const variables of
5017 such type); use this function when what you care about is whether or not
5018 to try to call a constructor to create an object. The latter case is
5019 the former plus some cases of constructors that cannot be called. */
5021 bool
5023 {
5024 tree inner;
5030 }
5032 /* Remove all zero-width bit-fields from T. */
5034 static void
5036 {
5041 {
5044 /* We should not be confused by the fact that grokbitfield
5045 temporarily sets the width of the bit field into
5046 DECL_INITIAL (*fieldsp).
5047 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5048 to that width. */
5051 else
5053 }
5054 }
5056 /* Returns TRUE iff we need a cookie when dynamically allocating an
5057 array whose elements have the indicated class TYPE. */
5059 static bool
5061 {
5062 tree fns;
5067 /* If there's a non-trivial destructor, we need a cookie. In order
5068 to iterate through the array calling the destructor for each
5069 element, we'll have to know how many elements there are. */
5073 /* If the usual deallocation function is a two-argument whose second
5074 argument is of type `size_t', then we have to pass the size of
5075 the array to the deallocation function, so we will need to store
5076 a cookie. */
5080 /* If there are no `operator []' members, or the lookup is
5081 ambiguous, then we don't need a cookie. */
5084 /* Loop through all of the functions. */
5086 {
5087 tree fn;
5088 tree second_parm;
5090 /* Select the current function. */
5092 /* See if this function is a one-argument delete function. If
5093 it is, then it will be the usual deallocation function. */
5097 /* Do not consider this function if its second argument is an
5098 ellipsis. */
5101 /* Otherwise, if we have a two-argument function and the second
5102 argument is `size_t', it will be the usual deallocation
5103 function -- unless there is one-argument function, too. */
5107 }
5110 }
5112 /* Finish computing the `literal type' property of class type T.
5114 At this point, we have already processed base classes and
5115 non-static data members. We need to check whether the copy
5116 constructor is trivial, the destructor is trivial, and there
5117 is a trivial default constructor or at least one constexpr
5118 constructor other than the copy constructor. */
5120 static void
5122 {
5123 tree fn;
5139 {
5142 {
5146 }
5147 }
5148 }
5150 /* T is a non-literal type used in a context which requires a constant
5151 expression. Explain why it isn't literal. */
5153 void
5155 {
5165 /* Already explained. */
5174 {
5176 "default constructor, and has no constexpr constructor that "
5180 {
5181 /* Note that we can't simply call locate_ctor because when the
5182 constructor is deleted it just returns NULL_TREE. */
5183 tree fns;
5185 {
5192 {
5195 else
5198 }
5199 }
5200 }
5201 }
5202 else
5203 {
5207 {
5210 {
5215 }
5216 }
5218 {
5219 tree ftype;
5224 {
5229 }
5230 }
5231 }
5232 }
5234 /* Check the validity of the bases and members declared in T. Add any
5235 implicitly-generated functions (like copy-constructors and
5236 assignment operators). Compute various flag bits (like
5237 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5238 level: i.e., independently of the ABI in use. */
5240 static void
5242 {
5243 /* Nonzero if the implicitly generated copy constructor should take
5244 a non-const reference argument. */
5246 /* Nonzero if the implicitly generated assignment operator
5247 should take a non-const reference argument. */
5249 tree access_decls;
5252 tree fn;
5254 /* By default, we use const reference arguments and generate default
5255 constructors. */
5259 /* Check all the base-classes. */
5263 /* Deduce noexcept on destructors. This needs to happen after we've set
5264 triviality flags appropriately for our bases. */
5268 /* Check all the method declarations. */
5271 /* Save the initial values of these flags which only indicate whether
5272 or not the class has user-provided functions. As we analyze the
5273 bases and members we can set these flags for other reasons. */
5277 /* Check all the data member declarations. We cannot call
5278 check_field_decls until we have called check_bases check_methods,
5279 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5280 being set appropriately. */
5285 /* A nearly-empty class has to be vptr-containing; a nearly empty
5286 class contains just a vptr. */
5290 /* Do some bookkeeping that will guide the generation of implicitly
5291 declared member functions. */
5294 /* We need to call a constructor for this class if it has a
5295 user-provided constructor, or if the default constructor is going
5296 to initialize the vptr. (This is not an if-and-only-if;
5297 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5298 themselves need constructing.) */
5301 /* [dcl.init.aggr]
5303 An aggregate is an array or a class with no user-provided
5304 constructors ... and no virtual functions.
5306 Again, other conditions for being an aggregate are checked
5307 elsewhere. */
5310 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5311 retain the old definition internally for ABI reasons. */
5320 /* If the class has no user-declared constructor, but does have
5321 non-static const or reference data members that can never be
5322 initialized, issue a warning. */
5324 /* Classes with user-declared constructors are presumed to
5325 initialize these members. */
5327 /* Aggregates can be initialized with brace-enclosed
5328 initializers. */
5330 {
5331 tree field;
5334 {
5335 tree type;
5350 }
5351 }
5353 /* Synthesize any needed methods. */
5355 cant_have_const_ctor,
5356 no_const_asn_ref);
5358 /* Check defaulted declarations here so we have cant_have_const_ctor
5359 and don't need to worry about clones. */
5362 {
5365 {
5366 bool imp_const_p
5372 /* If the function is defaulted outside the class, we just
5373 give the synthesis error. */
5376 }
5378 }
5381 {
5382 /* "The closure type associated with a lambda-expression has a deleted
5383 default constructor and a deleted copy assignment operator." */
5389 /* "This class type is not an aggregate." */
5391 }
5393 /* Compute the 'literal type' property before we
5394 do anything with non-static member functions. */
5397 /* Create the in-charge and not-in-charge variants of constructors
5398 and destructors. */
5401 /* Process the using-declarations. */
5405 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5408 /* Figure out whether or not we will need a cookie when dynamically
5409 allocating an array of this type. */
5412 }
5414 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5415 accordingly. If a new vfield was created (because T doesn't have a
5416 primary base class), then the newly created field is returned. It
5417 is not added to the TYPE_FIELDS list; it is the caller's
5418 responsibility to do that. Accumulate declared virtual functions
5419 on VIRTUALS_P. */
5421 static tree
5423 {
5424 tree fn;
5426 /* Collect the virtual functions declared in T. */
5430 {
5439 }
5441 /* If we couldn't find an appropriate base class, create a new field
5442 here. Even if there weren't any new virtual functions, we might need a
5443 new virtual function table if we're supposed to include vptrs in
5444 all classes that need them. */
5446 {
5447 /* We build this decl with vtbl_ptr_type_node, which is a
5448 `vtable_entry_type*'. It might seem more precise to use
5449 `vtable_entry_type (*)[N]' where N is the number of virtual
5450 functions. However, that would require the vtable pointer in
5451 base classes to have a different type than the vtable pointer
5452 in derived classes. We could make that happen, but that
5453 still wouldn't solve all the problems. In particular, the
5454 type-based alias analysis code would decide that assignments
5455 to the base class vtable pointer can't alias assignments to
5456 the derived class vtable pointer, since they have different
5457 types. Thus, in a derived class destructor, where the base
5458 class constructor was inlined, we could generate bad code for
5459 setting up the vtable pointer.
5461 Therefore, we use one type for all vtable pointers. We still
5462 use a type-correct type; it's just doesn't indicate the array
5463 bounds. That's better than using `void*' or some such; it's
5464 cleaner, and it let's the alias analysis code know that these
5465 stores cannot alias stores to void*! */
5466 tree field;
5479 /* This class is non-empty. */
5483 }
5486 }
5488 /* Add OFFSET to all base types of BINFO which is a base in the
5489 hierarchy dominated by T.
5491 OFFSET, which is a type offset, is number of bytes. */
5493 static void
5495 {
5497 tree primary_binfo;
5498 tree base_binfo;
5500 /* Update BINFO's offset. */
5505 offset));
5507 /* Find the primary base class. */
5513 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5514 downwards. */
5516 {
5517 /* Don't do the primary base twice. */
5525 }
5526 }
5528 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5529 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5530 empty subobjects of T. */
5532 static void
5534 {
5535 tree vbase;
5544 {
5545 /* In G++ 3.2, we incorrectly rounded the size before laying out
5546 the virtual bases. */
5548 #ifdef STRUCTURE_SIZE_BOUNDARY
5549 /* Packed structures don't need to have minimum size. */
5552 #endif
5556 }
5558 /* Find the last field. The artificial fields created for virtual
5559 bases will go after the last extant field to date. */
5564 /* Go through the virtual bases, allocating space for each virtual
5565 base that is not already a primary base class. These are
5566 allocated in inheritance graph order. */
5568 {
5573 {
5576 /* This virtual base is not a primary base of any class in the
5577 hierarchy, so we have to add space for it. */
5581 /* If the first virtual base might have been placed at a
5582 lower address, had we started from CLASSTYPE_SIZE, rather
5583 than TYPE_SIZE, issue a warning. There can be both false
5584 positives and false negatives from this warning in rare
5585 cases; to deal with all the possibilities would probably
5586 require performing both layout algorithms and comparing
5587 the results which is not particularly tractable. */
5589 && first_vbase
5590 && (tree_int_cst_lt
5595 bitsize_unit_node),
5598 "offset of virtual base %qT is not ABI-compliant and "
5600 basetype);
5603 }
5604 }
5605 }
5607 /* Returns the offset of the byte just past the end of the base class
5608 BINFO. */
5610 static tree
5612 {
5613 tree size;
5618 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5619 allocate some space for it. It cannot have virtual bases, so
5620 TYPE_SIZE_UNIT is fine. */
5622 else
5626 }
5628 /* Returns the offset of the byte just past the end of the base class
5629 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5630 only non-virtual bases are included. */
5632 static tree
5634 {
5637 tree binfo;
5638 tree base_binfo;
5639 tree offset;
5644 {
5654 }
5656 /* G++ 3.2 did not check indirect virtual bases. */
5660 {
5664 }
5667 }
5669 /* Warn about bases of T that are inaccessible because they are
5670 ambiguous. For example:
5672 struct S {};
5673 struct T : public S {};
5674 struct U : public S, public T {};
5676 Here, `(S*) new U' is not allowed because there are two `S'
5677 subobjects of U. */
5679 static void
5681 {
5684 tree basetype;
5685 tree binfo;
5686 tree base_binfo;
5688 /* If there are no repeated bases, nothing can be ambiguous. */
5692 /* Check direct bases. */
5695 {
5701 }
5703 /* Check for ambiguous virtual bases. */
5707 {
5713 }
5714 }
5716 /* Compare two INTEGER_CSTs K1 and K2. */
5718 static int
5720 {
5722 }
5724 /* Increase the size indicated in RLI to account for empty classes
5725 that are "off the end" of the class. */
5727 static void
5729 {
5730 tree eoc;
5731 tree rli_size;
5733 /* It might be the case that we grew the class to allocate a
5734 zero-sized base class. That won't be reflected in RLI, yet,
5735 because we are willing to overlay multiple bases at the same
5736 offset. However, now we need to make sure that RLI is big enough
5737 to reflect the entire class. */
5743 {
5745 /* In version 1 of the ABI, the size of a class that ends with
5746 a bitfield was not rounded up to a whole multiple of a
5747 byte. Because rli_size_unit_so_far returns only the number
5748 of fully allocated bytes, any extra bits were not included
5749 in the size. */
5751 else
5752 /* The size should have been rounded to a whole byte. */
5755 rli->bitpos
5764 }
5765 }
5767 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5768 BINFO_OFFSETs for all of the base-classes. Position the vtable
5769 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5771 static void
5773 {
5774 tree non_static_data_members;
5775 tree field;
5776 tree vptr;
5777 record_layout_info rli;
5778 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5779 types that appear at that offset. */
5780 splay_tree empty_base_offsets;
5781 /* True if the last field layed out was a bit-field. */
5783 /* The location at which the next field should be inserted. */
5785 /* T, as a base class. */
5786 tree base_t;
5788 /* Keep track of the first non-static data member. */
5791 /* Start laying out the record. */
5794 /* Mark all the primary bases in the hierarchy. */
5797 /* Create a pointer to our virtual function table. */
5800 /* The vptr is always the first thing in the class. */
5802 {
5807 }
5808 else
5811 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5816 /* Layout the non-static data members. */
5818 {
5819 tree type;
5820 tree padding;
5822 /* We still pass things that aren't non-static data members to
5823 the back end, in case it wants to do something with them. */
5825 {
5827 /* If the static data member has incomplete type, keep track
5828 of it so that it can be completed later. (The handling
5829 of pending statics in finish_record_layout is
5830 insufficient; consider:
5832 struct S1;
5833 struct S2 { static S1 s1; };
5835 At this point, finish_record_layout will be called, but
5836 S1 is still incomplete.) */
5838 {
5840 /* The visibility of static data members is determined
5841 at their point of declaration, not their point of
5842 definition. */
5844 }
5846 }
5854 /* If this field is a bit-field whose width is greater than its
5855 type, then there are some special rules for allocating
5856 it. */
5859 {
5861 tree integer_type;
5863 /* We must allocate the bits as if suitably aligned for the
5864 longest integer type that fits in this many bits. type
5865 of the field. Then, we are supposed to use the left over
5866 bits as additional padding. */
5875 /* ITK now indicates a type that is too large for the
5876 field. We have to back up by one to find the largest
5877 type that fits. */
5878 do
5879 {
5884 /* Figure out how much additional padding is required. GCC
5885 3.2 always created a padding field, even if it had zero
5886 width. */
5889 {
5891 /* In a union, the padding field must have the full width
5892 of the bit-field; all fields start at offset zero. */
5894 else
5895 {
5898 "ABI-compliant and may change in a future "
5900 t);
5903 }
5904 }
5905 #ifdef PCC_BITFIELD_TYPE_MATTERS
5906 /* An unnamed bitfield does not normally affect the
5907 alignment of the containing class on a target where
5908 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5909 make any exceptions for unnamed bitfields when the
5910 bitfields are longer than their types. Therefore, we
5911 temporarily give the field a name. */
5913 {
5916 }
5917 #endif
5922 empty_base_offsets);
5925 /* Now that layout has been performed, set the size of the
5926 field to the size of its declared type; the rest of the
5927 field is effectively invisible. */
5929 /* We must also reset the DECL_MODE of the field. */
5934 /* Versions of G++ before G++ 3.4 did not reset the
5935 DECL_MODE. */
5937 "the offset of %qD may not be ABI-compliant and may "
5939 }
5940 else
5942 empty_base_offsets);
5944 /* Remember the location of any empty classes in FIELD. */
5948 empty_base_offsets,
5951 /* If a bit-field does not immediately follow another bit-field,
5952 and yet it starts in the middle of a byte, we have failed to
5953 comply with the ABI. */
5956 /* The TREE_NO_WARNING flag gets set by Objective-C when
5957 laying out an Objective-C class. The ObjC ABI differs
5958 from the C++ ABI, and so we do not want a warning
5959 here. */
5961 && !last_field_was_bitfield
5964 bitsize_unit_node)))
5968 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5969 offset of the field. */
5976 "classes to be placed at different locations in a "
5979 /* The middle end uses the type of expressions to determine the
5980 possible range of expression values. In order to optimize
5981 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5982 must be made aware of the width of "i", via its type.
5984 Because C++ does not have integer types of arbitrary width,
5985 we must (for the purposes of the front end) convert from the
5986 type assigned here to the declared type of the bitfield
5987 whenever a bitfield expression is used as an rvalue.
5988 Similarly, when assigning a value to a bitfield, the value
5989 must be converted to the type given the bitfield here. */
5991 {
5996 {
6003 }
6004 }
6006 /* If we needed additional padding after this field, add it
6007 now. */
6009 {
6010 tree padding_field;
6013 FIELD_DECL,
6014 NULL_TREE,
6015 char_type_node);
6022 NULL_TREE,
6023 empty_base_offsets);
6024 }
6027 }
6030 {
6031 /* Make sure that we are on a byte boundary so that the size of
6032 the class without virtual bases will always be a round number
6033 of bytes. */
6036 }
6038 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6039 padding. */
6043 /* Delete all zero-width bit-fields from the list of fields. Now
6044 that the type is laid out they are no longer important. */
6047 /* Create the version of T used for virtual bases. We do not use
6048 make_class_type for this version; this is an artificial type. For
6049 a POD type, we just reuse T. */
6051 {
6054 /* Set the size and alignment for the new type. In G++ 3.2, all
6055 empty classes were considered to have size zero when used as
6056 base classes. */
6058 {
6063 "layout of classes derived from empty class %qT "
6065 t);
6066 }
6067 else
6068 {
6069 tree eoc;
6071 /* If the ABI version is not at least two, and the last
6072 field was a bit-field, RLI may not be on a byte
6073 boundary. In particular, rli_size_unit_so_far might
6074 indicate the last complete byte, while rli_size_so_far
6075 indicates the total number of bits used. Therefore,
6076 rli_size_so_far, rather than rli_size_unit_so_far, is
6077 used to compute TYPE_SIZE_UNIT. */
6085 eoc);
6092 }
6096 /* Copy the fields from T. */
6100 {
6102 FIELD_DECL,
6112 }
6114 /* Record the base version of the type. */
6117 }
6118 else
6121 /* Every empty class contains an empty class. */
6125 /* Set the TYPE_DECL for this type to contain the right
6126 value for DECL_OFFSET, so that we can use it as part
6127 of a COMPONENT_REF for multiple inheritance. */
6130 /* Now fix up any virtual base class types that we left lying
6131 around. We must get these done before we try to lay out the
6132 virtual function table. As a side-effect, this will remove the
6133 base subobject fields. */
6136 /* Make sure that empty classes are reflected in RLI at this
6137 point. */
6140 /* Make sure not to create any structures with zero size. */
6146 /* If this is a non-POD, declaring it packed makes a difference to how it
6147 can be used as a field; don't let finalize_record_size undo it. */
6151 /* Let the back end lay out the type. */
6154 /* Warn about bases that can't be talked about due to ambiguity. */
6157 /* Now that we're done with layout, give the base fields the real types. */
6162 /* Clean up. */
6169 }
6171 /* Determine the "key method" for the class type indicated by TYPE,
6172 and set CLASSTYPE_KEY_METHOD accordingly. */
6174 void
6176 {
6177 tree method;
6180 || processing_template_decl
6185 /* The key method is the first non-pure virtual function that is not
6186 inline at the point of class definition. On some targets the
6187 key function may not be inline; those targets should not call
6188 this function until the end of the translation unit. */
6194 {
6197 }
6200 }
6203 /* Allocate and return an instance of struct sorted_fields_type with
6204 N fields. */
6208 {
6215 }
6218 /* Perform processing required when the definition of T (a class type)
6219 is complete. */
6221 void
6223 {
6224 tree x;
6225 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6229 {
6234 }
6236 /* If this type was previously laid out as a forward reference,
6237 make sure we lay it out again. */
6241 /* Make assumptions about the class; we'll reset the flags if
6242 necessary. */
6248 /* Do end-of-class semantic processing: checking the validity of the
6249 bases and members and add implicitly generated methods. */
6252 /* Find the key method. */
6254 {
6255 /* The Itanium C++ ABI permits the key method to be chosen when
6256 the class is defined -- even though the key method so
6257 selected may later turn out to be an inline function. On
6258 some systems (such as ARM Symbian OS) the key method cannot
6259 be determined until the end of the translation unit. On such
6260 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6261 will cause the class to be added to KEYED_CLASSES. Then, in
6262 finish_file we will determine the key method. */
6266 /* If a polymorphic class has no key method, we may emit the vtable
6267 in every translation unit where the class definition appears. */
6270 }
6272 /* Layout the class itself. */
6275 /* We use the base type for trivial assignments, and hence it
6276 needs a mode. */
6281 /* If necessary, create the primary vtable for this class. */
6283 {
6284 /* We must enter these virtuals into the table. */
6288 /* Here we know enough to change the type of our virtual
6289 function table, but we will wait until later this function. */
6292 /* If we're warning about ABI tags, check the types of the new
6293 virtual functions. */
6297 }
6300 {
6302 tree fn;
6309 /* Add entries for virtual functions introduced by this class. */
6313 /* Set DECL_VINDEX for all functions declared in this class. */
6315 fn;
6317 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6319 {
6323 /* A thunk. We should never be calling this entry directly
6324 from this vtable -- we'd use the entry for the non
6325 thunk base function. */
6329 }
6330 }
6335 /* Complete the rtl for any static member objects of the type we're
6336 working on. */
6343 /* Done with FIELDS...now decide whether to sort these for
6344 faster lookups later.
6346 We use a small number because most searches fail (succeeding
6347 ultimately as the search bores through the inheritance
6348 hierarchy), and we want this failure to occur quickly. */
6352 /* Complain if one of the field types requires lower visibility. */
6355 /* Make the rtl for any new vtables we have created, and unmark
6356 the base types we marked. */
6359 /* Build the VTT for T. */
6362 /* This warning does not make sense for Java classes, since they
6363 cannot have destructors. */
6365 {
6366 tree dtor;
6370 if it were virtual, we would have created it by now. */
6371 !dtor
6380 "%q#T has virtual functions and accessible"
6382 }
6389 /* Class layout, assignment of virtual table slots, etc., is now
6390 complete. Give the back end a chance to tweak the visibility of
6391 the class or perform any other required target modifications. */
6398 /* Finish debugging output for this type. */
6402 {
6405 {
6408 }
6410 {
6413 else
6414 {
6417 }
6419 }
6421 {
6423 "the type of the first field has a different ABI from the "
6426 }
6427 }
6428 }
6430 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6431 equal to THRESHOLD or greater than THRESHOLD. */
6433 static void
6435 {
6438 {
6443 }
6444 }
6446 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6448 void
6450 {
6453 {
6455 int n_fields
6466 }
6467 }
6469 /* When T was built up, the member declarations were added in reverse
6470 order. Rearrange them to declaration order. */
6472 void
6474 {
6475 tree next;
6476 tree prev;
6477 tree x;
6479 /* The following lists are all in reverse order. Put them in
6480 declaration order now. */
6484 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6485 reverse order, so we can't just use nreverse. */
6490 {
6494 }
6496 {
6500 }
6501 }
6503 tree
6505 {
6508 /* Now that we've got all the field declarations, reverse everything
6509 as necessary. */
6514 /* Nadger the current location so that diagnostics point to the start of
6515 the struct, not the end. */
6519 {
6520 tree x;
6526 /* We need to emit an error message if this type was used as a parameter
6527 and it is an abstract type, even if it is a template. We construct
6528 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6529 account and we call complete_vars with this type, which will check
6530 the PARM_DECLS. Note that while the type is being defined,
6531 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6532 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6538 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6539 an enclosing scope is a template class, so that this function be
6540 found by lookup_fnfields_1 when the using declaration is not
6541 instantiated yet. */
6544 {
6549 }
6551 /* Remember current #pragma pack value. */
6554 /* Fix up any variants we've already built. */
6556 {
6561 }
6562 }
6563 else
6572 else
6576 /* Lambdas are defined by the LAMBDA_EXPR. */
6581 }
6582 \f
6583 /* Hash table to avoid endless recursion when handling references. */
6586 /* Return the dynamic type of INSTANCE, if known.
6587 Used to determine whether the virtual function table is needed
6588 or not.
6590 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6591 of our knowledge of its type. *NONNULL should be initialized
6592 before this function is called. */
6594 static tree
6596 {
6597 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6600 {
6604 else
6608 /* This is a call to a constructor, hence it's never zero. */
6610 {
6614 }
6618 /* This is a call to a constructor, hence it's never zero. */
6620 {
6624 }
6633 /* Propagate nonnull. */
6638 CASE_CONVERT:
6644 {
6645 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6646 with a real object -- given &p->f, p can still be null. */
6648 /* ??? Probably should check DECL_WEAK here. */
6651 }
6655 /* If this component is really a base class reference, then the field
6656 itself isn't definitive. */
6665 {
6669 }
6670 /* fall through... */
6675 {
6679 }
6681 {
6685 /* if we're in a ctor or dtor, we know our type. If
6686 current_class_ptr is set but we aren't in a function, we're in
6687 an NSDMI (and therefore a constructor). */
6692 {
6696 }
6697 }
6699 {
6700 /* We only need one hash table because it is always left empty. */
6704 /* Reference variables should be references to objects. */
6708 /* Enter the INSTANCE in a table to prevent recursion; a
6709 variable's initializer may refer to the variable
6710 itself. */
6715 {
6716 tree type;
6725 }
6726 }
6731 }
6732 #undef RECUR
6733 }
6735 /* Return nonzero if the dynamic type of INSTANCE is known, and
6736 equivalent to the static type. We also handle the case where
6737 INSTANCE is really a pointer. Return negative if this is a
6738 ctor/dtor. There the dynamic type is known, but this might not be
6739 the most derived base of the original object, and hence virtual
6740 bases may not be layed out according to this type.
6742 Used to determine whether the virtual function table is needed
6743 or not.
6745 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6746 of our knowledge of its type. *NONNULL should be initialized
6747 before this function is called. */
6749 int
6751 {
6754 tree fixed;
6756 /* processing_template_decl can be false in a template if we're in
6757 fold_non_dependent_expr, but we still want to suppress this check. */
6759 {
6760 /* In a template we only care about the type of the result. */
6764 }
6774 }
6776 \f
6777 void
6779 {
6782 current_class_stack
6790 }
6792 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6794 static void
6796 {
6797 tree type;
6799 /* We are re-entering the same class we just left, so we don't
6800 have to search the whole inheritance matrix to find all the
6801 decls to bind again. Instead, we install the cached
6802 class_shadowed list and walk through it binding names. */
6805 /* Restore IDENTIFIER_TYPE_VALUE. */
6807 type;
6810 }
6812 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6813 appropriate for TYPE.
6815 So that we may avoid calls to lookup_name, we cache the _TYPE
6816 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6818 For multiple inheritance, we perform a two-pass depth-first search
6819 of the type lattice. */
6821 void
6823 {
6824 class_stack_node_t csn;
6828 /* Make sure there is enough room for the new entry on the stack. */
6830 {
6832 current_class_stack
6834 current_class_stack_size);
6835 }
6837 /* Insert a new entry on the class stack. */
6844 current_class_depth++;
6846 /* Now set up the new type. */
6852 /* By default, things in classes are private, while things in
6853 structures or unions are public. */
6855 ? access_private_node
6861 {
6862 /* Forcibly remove any old class remnants. */
6864 }
6870 else
6872 }
6874 /* When we exit a toplevel class scope, we save its binding level so
6875 that we can restore it quickly. Here, we've entered some other
6876 class, so we must invalidate our cache. */
6878 void
6880 {
6882 }
6884 /* Get out of the current class scope. If we were in a class scope
6885 previously, that is the one popped to. */
6887 void
6889 {
6892 current_class_depth--;
6898 }
6900 /* Mark the top of the class stack as hidden. */
6902 void
6904 {
6907 }
6909 /* Mark the top of the class stack as un-hidden. */
6911 void
6913 {
6916 }
6918 /* Returns 1 if the class type currently being defined is either T or
6919 a nested type of T. */
6921 bool
6923 {
6931 /* We start looking from 1 because entry 0 is from global scope,
6932 and has no type. */
6934 {
6935 tree c;
6938 else
6939 {
6943 }
6948 }
6950 }
6952 /* If either current_class_type or one of its enclosing classes are derived
6953 from T, return the appropriate type. Used to determine how we found
6954 something via unqualified lookup. */
6956 tree
6958 {
6961 /* The bases of a dependent type are unknown. */
6972 {
6977 }
6980 }
6982 /* Returns the innermost class type which is not a lambda closure type. */
6984 tree
6986 {
6989 /* We start looking from 1 because entry 0 is from global scope,
6990 and has no type. */
6992 {
6993 tree c;
6996 else
6997 {
7001 }
7006 }
7008 }
7010 /* When entering a class scope, all enclosing class scopes' names with
7011 static meaning (static variables, static functions, types and
7012 enumerators) have to be visible. This recursive function calls
7013 pushclass for all enclosing class contexts until global or a local
7014 scope is reached. TYPE is the enclosed class. */
7016 void
7018 {
7019 /* A namespace might be passed in error cases, like A::B:C. */
7027 }
7029 /* Undoes a push_nested_class call. */
7031 void
7033 {
7039 }
7041 /* Returns the number of extern "LANG" blocks we are nested within. */
7043 int
7045 {
7047 }
7049 /* Set global variables CURRENT_LANG_NAME to appropriate value
7050 so that behavior of name-mangling machinery is correct. */
7052 void
7054 {
7058 {
7060 }
7062 {
7064 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7065 (See record_builtin_java_type in decl.c.) However, that causes
7066 incorrect debug entries if these types are actually used.
7067 So we re-enable debug output after extern "Java". */
7076 }
7078 {
7080 }
7081 else
7083 }
7085 /* Get out of the current language scope. */
7087 void
7089 {
7091 }
7092 \f
7093 /* Type instantiation routines. */
7095 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7096 matches the TARGET_TYPE. If there is no satisfactory match, return
7097 error_mark_node, and issue an error & warning messages under
7098 control of FLAGS. Permit pointers to member function if FLAGS
7099 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7100 a template-id, and EXPLICIT_TARGS are the explicitly provided
7101 template arguments.
7103 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7104 is the base path used to reference those member functions. If
7105 the address is resolved to a member function, access checks will be
7106 performed and errors issued if appropriate. */
7108 static tree
7110 tree overload,
7111 tsubst_flags_t flags,
7113 tree explicit_targs,
7114 tree access_path)
7115 {
7116 /* Here's what the standard says:
7118 [over.over]
7120 If the name is a function template, template argument deduction
7121 is done, and if the argument deduction succeeds, the deduced
7122 arguments are used to generate a single template function, which
7123 is added to the set of overloaded functions considered.
7125 Non-member functions and static member functions match targets of
7126 type "pointer-to-function" or "reference-to-function." Nonstatic
7127 member functions match targets of type "pointer-to-member
7128 function;" the function type of the pointer to member is used to
7129 select the member function from the set of overloaded member
7130 functions. If a nonstatic member function is selected, the
7131 reference to the overloaded function name is required to have the
7132 form of a pointer to member as described in 5.3.1.
7134 If more than one function is selected, any template functions in
7135 the set are eliminated if the set also contains a non-template
7136 function, and any given template function is eliminated if the
7137 set contains a second template function that is more specialized
7138 than the first according to the partial ordering rules 14.5.5.2.
7139 After such eliminations, if any, there shall remain exactly one
7140 selected function. */
7143 /* We store the matches in a TREE_LIST rooted here. The functions
7144 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7145 interoperability with most_specialized_instantiation. */
7147 tree fn;
7148 tree target_fn_type;
7150 /* By the time we get here, we should be seeing only real
7151 pointer-to-member types, not the internal POINTER_TYPE to
7152 METHOD_TYPE representation. */
7158 /* Check that the TARGET_TYPE is reasonable. */
7163 /* This is OK, too. */
7166 /* This is OK, too. This comes from a conversion to reference
7167 type. */
7169 else
7170 {
7176 }
7178 /* Non-member functions and static member functions match targets of type
7179 "pointer-to-function" or "reference-to-function." Nonstatic member
7180 functions match targets of type "pointer-to-member-function;" the
7181 function type of the pointer to member is used to select the member
7182 function from the set of overloaded member functions.
7184 So figure out the FUNCTION_TYPE that we want to match against. */
7187 /* If we can find a non-template function that matches, we can just
7188 use it. There's no point in generating template instantiations
7189 if we're just going to throw them out anyhow. But, of course, we
7190 can only do this when we don't *need* a template function. */
7192 {
7193 tree fns;
7196 {
7200 /* We're not looking for templates just yet. */
7205 /* We're looking for a non-static member, and this isn't
7206 one, or vice versa. */
7209 /* Ignore functions which haven't been explicitly
7210 declared. */
7214 /* See if there's a match. */
7217 }
7218 }
7220 /* Now, if we've already got a match (or matches), there's no need
7221 to proceed to the template functions. But, if we don't have a
7222 match we need to look at them, too. */
7224 {
7225 tree target_arg_types;
7226 tree target_ret_type;
7227 tree fns;
7230 tree arg;
7244 {
7246 tree instantiation;
7247 tree targs;
7250 /* We're only looking for templates. */
7255 /* We're not looking for a non-static member, and this is
7256 one, or vice versa. */
7261 /* If the template has a deduced return type, don't expose it to
7262 template argument deduction. */
7266 /* Try to do argument deduction. */
7273 /* Instantiation failed. */
7276 /* And now force instantiation to do return type deduction. */
7278 {
7284 }
7286 /* See if there's a match. */
7291 }
7293 /* Now, remove all but the most specialized of the matches. */
7295 {
7300 NULL_TREE,
7301 NULL_TREE);
7302 }
7303 }
7305 /* Now we should have exactly one function in MATCHES. */
7307 {
7308 /* There were *no* matches. */
7310 {
7313 target_type);
7316 }
7318 }
7320 {
7321 /* There were too many matches. First check if they're all
7322 the same function. */
7327 /* For multi-versioned functions, more than one match is just fine and
7328 decls_match will return false as they are different. */
7336 {
7338 {
7341 target_type);
7343 /* Since print_candidates expects the functions in the
7344 TREE_VALUE slot, we flip them here. */
7349 }
7352 }
7353 }
7355 /* Good, exactly one match. Now, convert it to the correct type. */
7360 {
7368 {
7371 }
7372 }
7374 /* If a pointer to a function that is multi-versioned is requested, the
7375 pointer to the dispatcher function is returned instead. This works
7376 well because indirectly calling the function will dispatch the right
7377 function version at run-time. */
7379 {
7383 /* Mark all the versions corresponding to the dispatcher as used. */
7386 }
7388 /* If we're doing overload resolution purely for the purpose of
7389 determining conversion sequences, we should not consider the
7390 function used. If this conversion sequence is selected, the
7391 function will be marked as used at this point. */
7393 {
7394 /* Make =delete work with SFINAE. */
7399 }
7401 /* We could not check access to member functions when this
7402 expression was originally created since we did not know at that
7403 time to which function the expression referred. */
7405 {
7408 }
7412 else
7413 {
7414 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7415 will mark the function as addressed, but here we must do it
7416 explicitly. */
7420 }
7421 }
7423 /* This function will instantiate the type of the expression given in
7424 RHS to match the type of LHSTYPE. If errors exist, then return
7425 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7426 we complain on errors. If we are not complaining, never modify rhs,
7427 as overload resolution wants to try many possible instantiations, in
7428 the hope that at least one will work.
7430 For non-recursive calls, LHSTYPE should be a function, pointer to
7431 function, or a pointer to member function. */
7433 tree
7435 {
7442 {
7446 }
7449 {
7456 /* Microsoft allows `A::f' to be resolved to a
7457 pointer-to-member. */
7458 ;
7459 else
7460 {
7465 }
7466 }
7469 {
7472 }
7474 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7475 deduce any type information. */
7477 {
7481 }
7483 /* There only a few kinds of expressions that may have a type
7484 dependent on overload resolution. */
7490 /* This should really only be used when attempting to distinguish
7491 what sort of a pointer to function we have. For now, any
7492 arithmetic operation which is not supported on pointers
7493 is rejected as an error. */
7496 {
7498 {
7504 /* Do not lose object's side effects. */
7508 }
7515 /* This can happen if we are forming a pointer-to-member for a
7516 member template. */
7519 /* Fall through. */
7522 {
7526 return
7530 }
7534 return
7538 access_path);
7541 {
7546 }
7553 }
7555 }
7556 \f
7557 /* Return the name of the virtual function pointer field
7558 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7559 this may have to look back through base types to find the
7560 ultimate field name. (For single inheritance, these could
7561 all be the same name. Who knows for multiple inheritance). */
7563 static tree
7565 {
7572 {
7578 }
7586 }
7588 void
7590 {
7597 {
7602 }
7603 }
7605 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7606 according to [class]:
7607 The class-name is also inserted
7608 into the scope of the class itself. For purposes of access checking,
7609 the inserted class name is treated as if it were a public member name. */
7611 void
7613 {
7616 tree saved_cas;
7631 }
7633 /* Returns 1 if TYPE contains only padding bytes. */
7635 int
7637 {
7644 /* In G++ 3.2, whether or not a class was empty was determined by
7645 looking at its size. */
7648 else
7650 }
7652 /* Returns true if TYPE contains an empty class. */
7654 static bool
7656 {
7660 {
7661 tree field;
7662 tree binfo;
7663 tree base_binfo;
7675 }
7679 }
7681 /* Returns true if TYPE contains no actual data, just various
7682 possible combinations of empty classes and possibly a vptr. */
7684 bool
7686 {
7688 {
7689 tree field;
7690 tree binfo;
7691 tree base_binfo;
7694 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7695 out, but we'd like to be able to check this before then. */
7709 }
7713 }
7715 /* Note that NAME was looked up while the current class was being
7716 defined and that the result of that lookup was DECL. */
7718 void
7720 {
7721 splay_tree names_used;
7723 /* If we're not defining a class, there's nothing to do. */
7729 /* If there's already a binding for this NAME, then we don't have
7730 anything to worry about. */
7743 }
7745 /* Note that NAME was declared (as DECL) in the current class. Check
7746 to see that the declaration is valid. */
7748 void
7750 {
7751 splay_tree names_used;
7752 splay_tree_node n;
7754 /* Look to see if we ever used this name. */
7755 names_used
7759 /* The C language allows members to be declared with a type of the same
7760 name, and the C++ standard says this diagnostic is not required. So
7761 allow it in extern "C" blocks unless predantic is specified.
7762 Allow it in all cases if -ms-extensions is specified. */
7768 {
7769 /* [basic.scope.class]
7771 A name N used in a class S shall refer to the same declaration
7772 in its context and when re-evaluated in the completed scope of
7773 S. */
7777 }
7778 }
7780 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7781 Secondary vtables are merged with primary vtables; this function
7782 will return the VAR_DECL for the primary vtable. */
7784 tree
7786 {
7787 tree decl;
7791 {
7794 }
7798 }
7801 /* Returns the binfo for the primary base of BINFO. If the resulting
7802 BINFO is a virtual base, and it is inherited elsewhere in the
7803 hierarchy, then the returned binfo might not be the primary base of
7804 BINFO in the complete object. Check BINFO_PRIMARY_P or
7805 BINFO_LOST_PRIMARY_P to be sure. */
7807 static tree
7809 {
7810 tree primary_base;
7817 }
7819 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7821 static int
7823 {
7827 }
7829 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7830 INDENT should be zero when called from the top level; it is
7831 incremented recursively. IGO indicates the next expected BINFO in
7832 inheritance graph ordering. */
7834 static tree
7837 tree binfo,
7838 tree igo,
7840 {
7842 tree base_binfo;
7850 {
7853 }
7868 {
7872 TFF_PLAIN_IDENTIFIER),
7874 }
7876 {
7879 }
7884 {
7888 {
7892 TFF_PLAIN_IDENTIFIER));
7893 }
7895 {
7899 TFF_PLAIN_IDENTIFIER));
7900 }
7902 {
7906 TFF_PLAIN_IDENTIFIER));
7907 }
7909 {
7913 TFF_PLAIN_IDENTIFIER));
7914 }
7918 }
7924 }
7926 /* Dump the BINFO hierarchy for T. */
7928 static void
7930 {
7942 }
7944 /* Debug interface to hierarchy dumping. */
7946 void
7948 {
7950 }
7952 static void
7954 {
7959 {
7962 }
7963 }
7965 static void
7967 {
7968 tree value;
7970 HOST_WIDE_INT elt;
7978 TFF_PLAIN_IDENTIFIER));
7985 }
7987 static void
7989 {
7997 {
8004 {
8009 }
8013 }
8016 }
8018 static void
8020 {
8028 {
8033 }
8036 }
8038 /* Dump a function or thunk and its thunkees. */
8040 static void
8042 {
8045 tree thunks;
8053 {
8063 else
8069 }
8073 }
8075 /* Dump the thunks for FN. */
8077 void
8079 {
8081 }
8083 /* Virtual function table initialization. */
8085 /* Create all the necessary vtables for T and its base classes. */
8087 static void
8089 {
8090 tree vbase;
8094 /* We lay out the primary and secondary vtables in one contiguous
8095 vtable. The primary vtable is first, followed by the non-virtual
8096 secondary vtables in inheritance graph order. */
8100 /* Then come the virtual bases, also in inheritance graph order. */
8102 {
8106 }
8110 }
8112 /* Initialize the vtable for BINFO with the INITS. */
8114 static void
8116 {
8117 tree decl;
8123 }
8125 /* Build the VTT (virtual table table) for T.
8126 A class requires a VTT if it has virtual bases.
8128 This holds
8129 1 - primary virtual pointer for complete object T
8130 2 - secondary VTTs for each direct non-virtual base of T which requires a
8131 VTT
8132 3 - secondary virtual pointers for each direct or indirect base of T which
8133 has virtual bases or is reachable via a virtual path from T.
8134 4 - secondary VTTs for each direct or indirect virtual base of T.
8136 Secondary VTTs look like complete object VTTs without part 4. */
8138 static void
8140 {
8141 tree type;
8142 tree vtt;
8143 tree index;
8146 /* Build up the initializers for the VTT. */
8151 /* If we didn't need a VTT, we're done. */
8155 /* Figure out the type of the VTT. */
8159 /* Now, build the VTT object itself. */
8162 /* Add the VTT to the vtables list. */
8167 }
8169 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8170 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8171 and CHAIN the vtable pointer for this binfo after construction is
8172 complete. VALUE can also be another BINFO, in which case we recurse. */
8174 static tree
8176 {
8177 tree vt;
8180 {
8186 else
8188 }
8191 }
8193 /* Data for secondary VTT initialization. */
8195 {
8196 /* Is this the primary VTT? */
8199 /* Current index into the VTT. */
8200 tree index;
8202 /* Vector of initializers built up. */
8205 /* The type being constructed by this secondary VTT. */
8206 tree type_being_constructed;
8209 /* Recursively build the VTT-initializer for BINFO (which is in the
8210 hierarchy dominated by T). INITS points to the end of the initializer
8211 list to date. INDEX is the VTT index where the next element will be
8212 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8213 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8214 for virtual bases of T. When it is not so, we build the constructor
8215 vtables for the BINFO-in-T variant. */
8217 static void
8220 {
8222 tree b;
8223 tree init;
8224 secondary_vptr_vtt_init_data data;
8227 /* We only need VTTs for subobjects with virtual bases. */
8231 /* We need to use a construction vtable if this is not the primary
8232 VTT. */
8234 {
8237 /* Record the offset in the VTT where this sub-VTT can be found. */
8239 }
8241 /* Add the address of the primary vtable for the complete object. */
8245 {
8248 }
8251 /* Recursively add the secondary VTTs for non-virtual bases. */
8256 /* Add secondary virtual pointers for all subobjects of BINFO with
8257 either virtual bases or reachable along a virtual path, except
8258 subobjects that are non-virtual primary bases. */
8268 /* data.inits might have grown as we added secondary virtual pointers.
8269 Make sure our caller knows about the new vector. */
8273 /* Add the secondary VTTs for virtual bases in inheritance graph
8274 order. */
8276 {
8281 }
8282 else
8283 /* Remove the ctor vtables we created. */
8285 }
8287 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8288 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8290 static tree
8292 {
8295 /* We don't care about bases that don't have vtables. */
8299 /* We're only interested in proper subobjects of the type being
8300 constructed. */
8304 /* We're only interested in bases with virtual bases or reachable
8305 via a virtual path from the type being constructed. */
8310 /* We're not interested in non-virtual primary bases. */
8314 /* Record the index where this secondary vptr can be found. */
8316 {
8321 {
8322 /* It's a primary virtual base, and this is not a
8323 construction vtable. Find the base this is primary of in
8324 the inheritance graph, and use that base's vtable
8325 now. */
8328 }
8329 }
8331 /* Add the initializer for the secondary vptr itself. */
8334 /* Advance the vtt index. */
8339 }
8341 /* Called from build_vtt_inits via dfs_walk. After building
8342 constructor vtables and generating the sub-vtt from them, we need
8343 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8344 binfo of the base whose sub vtt was generated. */
8346 static tree
8348 {
8352 /* If this class has no vtable, none of its bases do. */
8356 /* This might be a primary base, so have no vtable in this
8357 hierarchy. */
8360 /* If we scribbled the construction vtable vptr into BINFO, clear it
8361 out now. */
8367 }
8369 /* Build the construction vtable group for BINFO which is in the
8370 hierarchy dominated by T. */
8372 static void
8374 {
8375 tree type;
8376 tree vtbl;
8377 tree id;
8378 tree vbase;
8381 /* See if we've already created this construction vtable group. */
8387 /* Build a version of VTBL (with the wrong type) for use in
8388 constructing the addresses of secondary vtables in the
8389 construction vtable group. */
8392 /* Don't export construction vtables from shared libraries. Even on
8393 targets that don't support hidden visibility, this tells
8394 can_refer_decl_in_current_unit_p not to assume that it's safe to
8395 access from a different compilation unit (bz 54314). */
8403 /* Add the vtables for each of our virtual bases using the vbase in T
8404 binfo. */
8406 vbase;
8408 {
8409 tree b;
8416 }
8418 /* Figure out the type of the construction vtable. */
8425 /* Initialize the construction vtable. */
8429 }
8431 /* Add the vtbl initializers for BINFO (and its bases other than
8432 non-virtual primaries) to the list of INITS. BINFO is in the
8433 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8434 the constructor the vtbl inits should be accumulated for. (If this
8435 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8436 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8437 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8438 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8439 but are not necessarily the same in terms of layout. */
8441 static void
8443 tree orig_binfo,
8444 tree rtti_binfo,
8445 tree vtbl,
8446 tree t,
8448 {
8450 tree base_binfo;
8455 /* If it doesn't have a vptr, we don't do anything. */
8459 /* If we're building a construction vtable, we're not interested in
8460 subobjects that don't require construction vtables. */
8466 /* Build the initializers for the BINFO-in-T vtable. */
8469 /* Walk the BINFO and its bases. We walk in preorder so that as we
8470 initialize each vtable we can figure out at what offset the
8471 secondary vtable lies from the primary vtable. We can't use
8472 dfs_walk here because we need to iterate through bases of BINFO
8473 and RTTI_BINFO simultaneously. */
8475 {
8476 /* Skip virtual bases. */
8482 inits);
8483 }
8484 }
8486 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8487 BINFO vtable to L. */
8489 static void
8491 tree orig_binfo,
8492 tree rtti_binfo,
8493 tree orig_vtbl,
8494 tree t,
8496 {
8503 {
8504 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8505 primary virtual base. If it is not the same primary in
8506 the hierarchy of T, we'll need to generate a ctor vtable
8507 for it, to place at its location in T. If it is the same
8508 primary, we still need a VTT entry for the vtable, but it
8509 should point to the ctor vtable for the base it is a
8510 primary for within the sub-hierarchy of RTTI_BINFO.
8512 There are three possible cases:
8514 1) We are in the same place.
8515 2) We are a primary base within a lost primary virtual base of
8516 RTTI_BINFO.
8517 3) We are primary to something not a base of RTTI_BINFO. */
8519 tree b;
8522 /* First, look through the bases we are primary to for RTTI_BINFO
8523 or a virtual base. */
8526 {
8531 }
8532 /* If we run out of primary links, keep looking down our
8533 inheritance chain; we might be an indirect primary. */
8537 found:
8539 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8540 base B and it is a base of RTTI_BINFO, this is case 2. In
8541 either case, we share our vtable with LAST, i.e. the
8542 derived-most base within B of which we are a primary. */
8545 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8546 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8547 binfo_ctor_vtable after everything's been set up. */
8550 /* Otherwise, this is case 3 and we get our own. */
8551 }
8558 {
8559 tree index;
8562 /* Add the initializer for this vtable. */
8566 /* Figure out the position to which the VPTR should point. */
8572 }
8575 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8576 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8577 straighten this out. */
8580 /* Throw away any unneeded intializers. */
8582 else
8583 /* For an ordinary vtable, set BINFO_VTABLE. */
8585 }
8589 /* Construct the initializer for BINFO's virtual function table. BINFO
8590 is part of the hierarchy dominated by T. If we're building a
8591 construction vtable, the ORIG_BINFO is the binfo we should use to
8592 find the actual function pointers to put in the vtable - but they
8593 can be overridden on the path to most-derived in the graph that
8594 ORIG_BINFO belongs. Otherwise,
8595 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8596 BINFO that should be indicated by the RTTI information in the
8597 vtable; it will be a base class of T, rather than T itself, if we
8598 are building a construction vtable.
8600 The value returned is a TREE_LIST suitable for wrapping in a
8601 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8602 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8603 number of non-function entries in the vtable.
8605 It might seem that this function should never be called with a
8606 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8607 base is always subsumed by a derived class vtable. However, when
8608 we are building construction vtables, we do build vtables for
8609 primary bases; we need these while the primary base is being
8610 constructed. */
8612 static void
8614 tree orig_binfo,
8615 tree t,
8616 tree rtti_binfo,
8619 {
8620 tree v;
8621 vtbl_init_data vid;
8623 tree vbinfo;
8627 /* Initialize VID. */
8635 /* The first vbase or vcall offset is at index -3 in the vtable. */
8638 /* Add entries to the vtable for RTTI. */
8641 /* Create an array for keeping track of the functions we've
8642 processed. When we see multiple functions with the same
8643 signature, we share the vcall offsets. */
8645 /* Add the vcall and vbase offset entries. */
8648 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8649 build_vbase_offset_vtbl_entries. */
8654 /* If the target requires padding between data entries, add that now. */
8656 {
8661 /* Move data entries into their new positions and add padding
8662 after the new positions. Iterate backwards so we don't
8663 overwrite entries that we would need to process later. */
8666 ix--)
8667 {
8675 {
8679 null_pointer_node);
8680 }
8681 }
8682 }
8687 /* The initializers for virtual functions were built up in reverse
8688 order. Straighten them out and add them to the running list in one
8689 step. */
8698 /* Go through all the ordinary virtual functions, building up
8699 initializers. */
8701 {
8702 tree delta;
8703 tree vcall_index;
8710 {
8714 {
8717 }
8719 }
8721 /* If the only definition of this function signature along our
8722 primary base chain is from a lost primary, this vtable slot will
8723 never be used, so just zero it out. This is important to avoid
8724 requiring extra thunks which cannot be generated with the function.
8726 We first check this in update_vtable_entry_for_fn, so we handle
8727 restored primary bases properly; we also need to do it here so we
8728 zero out unused slots in ctor vtables, rather than filling them
8729 with erroneous values (though harmless, apart from relocation
8730 costs). */
8735 {
8736 /* Pull the offset for `this', and the function to call, out of
8737 the list. */
8744 /* You can't call an abstract virtual function; it's abstract.
8745 So, we replace these functions with __pure_virtual. */
8747 {
8750 {
8752 abort_fndecl_addr
8756 }
8757 }
8758 /* Likewise for deleted virtuals. */
8760 {
8765 NULL_TREE);
8769 }
8770 else
8771 {
8773 {
8777 }
8778 /* Take the address of the function, considering it to be of an
8779 appropriate generic type. */
8783 }
8784 }
8786 /* And add it to the chain of initializers. */
8788 {
8793 else
8795 {
8801 }
8802 }
8803 else
8805 }
8806 }
8808 /* Adds to vid->inits the initializers for the vbase and vcall
8809 offsets in BINFO, which is in the hierarchy dominated by T. */
8811 static void
8813 {
8814 tree b;
8816 /* If this is a derived class, we must first create entries
8817 corresponding to the primary base class. */
8822 /* Add the vbase entries for this base. */
8824 /* Add the vcall entries for this base. */
8826 }
8828 /* Returns the initializers for the vbase offset entries in the vtable
8829 for BINFO (which is part of the class hierarchy dominated by T), in
8830 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8831 where the next vbase offset will go. */
8833 static void
8835 {
8836 tree vbase;
8837 tree t;
8838 tree non_primary_binfo;
8840 /* If there are no virtual baseclasses, then there is nothing to
8841 do. */
8847 /* We might be a primary base class. Go up the inheritance hierarchy
8848 until we find the most derived class of which we are a primary base:
8849 it is the offset of that which we need to use. */
8852 {
8853 tree b;
8855 /* If we have reached a virtual base, then it must be a primary
8856 base (possibly multi-level) of vid->binfo, or we wouldn't
8857 have called build_vcall_and_vbase_vtbl_entries for it. But it
8858 might be a lost primary, so just skip down to vid->binfo. */
8860 {
8863 }
8869 }
8871 /* Go through the virtual bases, adding the offsets. */
8873 vbase;
8875 {
8876 tree b;
8877 tree delta;
8882 /* Find the instance of this virtual base in the complete
8883 object. */
8886 /* If we've already got an offset for this virtual base, we
8887 don't need another one. */
8892 /* Figure out where we can find this vbase offset. */
8901 /* The vbase offset had better be the same. */
8904 /* The next vbase will come at a more negative offset. */
8908 /* The initializer is the delta from BINFO to this virtual base.
8909 The vbase offsets go in reverse inheritance-graph order, and
8910 we are walking in inheritance graph order so these end up in
8911 the right order. */
8918 }
8919 }
8921 /* Adds the initializers for the vcall offset entries in the vtable
8922 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8923 to VID->INITS. */
8925 static void
8927 {
8928 /* We only need these entries if this base is a virtual base. We
8929 compute the indices -- but do not add to the vtable -- when
8930 building the main vtable for a class. */
8933 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8934 correspond to VID->DERIVED), we are building a primary
8935 construction virtual table. Since this is a primary
8936 virtual table, we do not need the vcall offsets for
8937 BINFO. */
8939 {
8940 /* We need a vcall offset for each of the virtual functions in this
8941 vtable. For example:
8943 class A { virtual void f (); };
8944 class B1 : virtual public A { virtual void f (); };
8945 class B2 : virtual public A { virtual void f (); };
8946 class C: public B1, public B2 { virtual void f (); };
8948 A C object has a primary base of B1, which has a primary base of A. A
8949 C also has a secondary base of B2, which no longer has a primary base
8950 of A. So the B2-in-C construction vtable needs a secondary vtable for
8951 A, which will adjust the A* to a B2* to call f. We have no way of
8952 knowing what (or even whether) this offset will be when we define B2,
8953 so we store this "vcall offset" in the A sub-vtable and look it up in
8954 a "virtual thunk" for B2::f.
8956 We need entries for all the functions in our primary vtable and
8957 in our non-virtual bases' secondary vtables. */
8959 /* If we are just computing the vcall indices -- but do not need
8960 the actual entries -- not that. */
8963 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8965 }
8966 }
8968 /* Build vcall offsets, starting with those for BINFO. */
8970 static void
8972 {
8974 tree primary_binfo;
8975 tree base_binfo;
8977 /* Don't walk into virtual bases -- except, of course, for the
8978 virtual base for which we are building vcall offsets. Any
8979 primary virtual base will have already had its offsets generated
8980 through the recursion in build_vcall_and_vbase_vtbl_entries. */
8984 /* If BINFO has a primary base, process it first. */
8989 /* Add BINFO itself to the list. */
8992 /* Scan the non-primary bases of BINFO. */
8996 }
8998 /* Called from build_vcall_offset_vtbl_entries_r. */
9000 static void
9002 {
9003 /* Make entries for the rest of the virtuals. */
9005 {
9006 tree orig_fn;
9008 /* The ABI requires that the methods be processed in declaration
9009 order. G++ 3.2 used the order in the vtable. */
9011 orig_fn;
9015 }
9016 else
9017 {
9018 tree derived_virtuals;
9019 tree base_virtuals;
9020 tree orig_virtuals;
9021 /* If BINFO is a primary base, the most derived class which has
9022 BINFO as a primary base; otherwise, just BINFO. */
9023 tree non_primary_binfo;
9025 /* We might be a primary base class. Go up the inheritance hierarchy
9026 until we find the most derived class of which we are a primary base:
9027 it is the BINFO_VIRTUALS there that we need to consider. */
9030 {
9031 tree b;
9033 /* If we have reached a virtual base, then it must be vid->vbase,
9034 because we ignore other virtual bases in
9035 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9036 base (possibly multi-level) of vid->binfo, or we wouldn't
9037 have called build_vcall_and_vbase_vtbl_entries for it. But it
9038 might be a lost primary, so just skip down to vid->binfo. */
9040 {
9044 }
9050 }
9053 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9054 where rtti_binfo is the most derived type. */
9055 non_primary_binfo
9061 base_virtuals;
9065 {
9066 tree orig_fn;
9068 /* Find the declaration that originally caused this function to
9069 be present in BINFO_TYPE (binfo). */
9072 /* When processing BINFO, we only want to generate vcall slots for
9073 function slots introduced in BINFO. So don't try to generate
9074 one if the function isn't even defined in BINFO. */
9079 }
9080 }
9081 }
9083 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9085 static void
9087 {
9089 tree vcall_offset;
9090 tree derived_entry;
9092 /* If there is already an entry for a function with the same
9093 signature as FN, then we do not need a second vcall offset.
9094 Check the list of functions already present in the derived
9095 class vtable. */
9097 {
9099 /* We only use one vcall offset for virtual destructors,
9100 even though there are two virtual table entries. */
9104 }
9106 /* If we are building these vcall offsets as part of building
9107 the vtable for the most derived class, remember the vcall
9108 offset. */
9110 {
9113 }
9115 /* The next vcall offset will be found at a more negative
9116 offset. */
9120 /* Keep track of this function. */
9124 {
9125 tree base;
9126 tree fn;
9128 /* Find the overriding function. */
9132 else
9133 {
9136 /* The vbase we're working on is a primary base of
9137 vid->binfo. But it might be a lost primary, so its
9138 BINFO_OFFSET might be wrong, so we just use the
9139 BINFO_OFFSET from vid->binfo. */
9145 vcall_offset);
9146 }
9147 /* Add the initializer to the vtable. */
9149 }
9150 }
9152 /* Return vtbl initializers for the RTTI entries corresponding to the
9153 BINFO's vtable. The RTTI entries should indicate the object given
9154 by VID->rtti_binfo. */
9156 static void
9158 {
9159 tree b;
9160 tree t;
9161 tree offset;
9162 tree decl;
9163 tree init;
9167 /* To find the complete object, we will first convert to our most
9168 primary base, and then add the offset in the vtbl to that value. */
9172 {
9173 tree primary_base;
9179 }
9183 /* The second entry is the address of the typeinfo object. */
9186 else
9189 /* Convert the declaration to a type that can be stored in the
9190 vtable. */
9194 /* Add the offset-to-top entry. It comes earlier in the vtable than
9195 the typeinfo entry. Convert the offset to look like a
9196 function pointer, so that we can put it in the vtable. */
9199 }
9201 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9202 accessibility. */
9204 bool
9206 {
9209 }
9211 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9213 bool
9215 {
9219 }