| blob | 286164d020294ef7b2f8fd4554698c0b26400807 |
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 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1358 complete) template arguments. */
1360 static void
1362 {
1365 {
1368 {
1372 }
1373 }
1375 /* Also mark ABI tags from template arguments. */
1377 {
1380 {
1383 {
1387 }
1388 }
1389 }
1390 }
1392 /* Check that class T has all the abi tags that subobject SUBOB has, or
1393 warn if not. */
1395 static void
1397 {
1406 }
1408 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1409 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1410 properties of the bases. */
1412 static void
1416 {
1420 tree base_binfo;
1421 tree binfo;
1431 {
1440 /* If any base class is non-literal, so is the derived class. */
1444 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1445 here because the case of virtual functions but non-virtual
1446 dtor is handled in finish_struct_1. */
1451 /* If the base class doesn't have copy constructors or
1452 assignment operators that take const references, then the
1453 derived class cannot have such a member automatically
1454 generated. */
1463 /* A virtual base does not effect nearly emptiness. */
1464 ;
1466 {
1468 /* And if there is more than one nearly empty base, then the
1469 derived class is not nearly empty either. */
1471 else
1472 /* Remember we've seen one. */
1474 }
1476 /* If the base class is not empty or nearly empty, then this
1477 class cannot be nearly empty. */
1480 /* A lot of properties from the bases also apply to the derived
1481 class. */
1499 /* A standard-layout class is a class that:
1500 ...
1501 * has no non-standard-layout base classes, */
1504 {
1505 tree basefield;
1506 /* ...has no base classes of the same type as the first non-static
1507 data member... */
1509 && (same_type_ignoring_top_level_qualifiers_p
1512 else
1513 /* ...either has no non-static data members in the most-derived
1514 class and at most one base class with non-static data
1515 members, or has no base classes with non-static data
1516 members */
1520 {
1523 else
1526 }
1527 }
1529 /* Don't bother collecting tm attributes if transactional memory
1530 support is not enabled. */
1532 {
1536 }
1539 }
1541 /* If one of the base classes had TM attributes, and the current class
1542 doesn't define its own, then the current class inherits one. */
1544 {
1547 }
1548 }
1550 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1551 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1552 that have had a nearly-empty virtual primary base stolen by some
1553 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1554 T. */
1556 static void
1558 {
1562 tree base_binfo;
1564 /* Determine the primary bases of our bases. */
1567 {
1570 /* See if we're the non-virtual primary of our inheritance
1571 chain. */
1573 {
1580 /* We are the primary binfo. */
1582 }
1583 /* Determine if we have a virtual primary base, and mark it so.
1584 */
1586 {
1590 /* Someone already claimed this base. */
1592 else
1593 {
1594 tree delta;
1599 /* A virtual binfo might have been copied from within
1600 another hierarchy. As we're about to use it as a
1601 primary base, make sure the offsets match. */
1609 }
1610 }
1611 }
1613 /* First look for a dynamic direct non-virtual base. */
1615 {
1619 {
1622 }
1623 }
1625 /* A "nearly-empty" virtual base class can be the primary base
1626 class, if no non-virtual polymorphic base can be found. Look for
1627 a nearly-empty virtual dynamic base that is not already a primary
1628 base of something in the hierarchy. If there is no such base,
1629 just pick the first nearly-empty virtual base. */
1635 {
1637 {
1638 /* Found one that is not primary. */
1641 }
1643 /* Remember the first candidate. */
1645 }
1647 found:
1648 /* If we've got a primary base, use it. */
1650 {
1655 /* We are stealing a primary base. */
1659 {
1660 tree delta;
1663 /* A virtual binfo might have been copied from within
1664 another hierarchy. As we're about to use it as a primary
1665 base, make sure the offsets match. */
1670 }
1677 }
1678 }
1680 /* Update the variant types of T. */
1682 void
1684 {
1685 tree variants;
1691 variants;
1693 {
1694 /* These fields are in the _TYPE part of the node, not in
1695 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1705 /* Copy whatever these are holding today. */
1709 }
1710 }
1712 /* Early variant fixups: we apply attributes at the beginning of the class
1713 definition, and we need to fix up any variants that have already been
1714 made via elaborated-type-specifier so that check_qualified_type works. */
1716 void
1718 {
1719 tree variants;
1725 variants;
1727 {
1728 /* These are the two fields that check_qualified_type looks at and
1729 are affected by attributes. */
1732 }
1733 }
1734 \f
1735 /* Set memoizing fields and bits of T (and its variants) for later
1736 use. */
1738 static void
1740 {
1741 /* Fix up variants (if any). */
1745 /* For a class w/o baseclasses, 'finish_struct' has set
1746 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1747 Similarly for a class whose base classes do not have vtables.
1748 When neither of these is true, we might have removed abstract
1749 virtuals (by providing a definition), added some (by declaring
1750 new ones), or redeclared ones from a base class. We need to
1751 recalculate what's really an abstract virtual at this point (by
1752 looking in the vtables). */
1755 /* If this type has a copy constructor or a destructor, force its
1756 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1757 nonzero. This will cause it to be passed by invisible reference
1758 and prevent it from being returned in a register. */
1761 {
1762 tree variants;
1765 {
1768 }
1769 }
1770 }
1772 /* Issue warnings about T having private constructors, but no friends,
1773 and so forth.
1775 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1776 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1777 non-private static member functions. */
1779 static void
1781 {
1784 tree fn;
1787 /* If the class has friends, those entities might create and
1788 access instances, so we should not warn. */
1791 /* We will have warned when the template was declared; there's
1792 no need to warn on every instantiation. */
1794 /* There's no reason to even consider warning about this
1795 class. */
1798 /* We only issue one warning, if more than one applies, because
1799 otherwise, on code like:
1801 class A {
1802 // Oops - forgot `public:'
1803 A();
1804 A(const A&);
1805 ~A();
1806 };
1808 we warn several times about essentially the same problem. */
1810 /* Check to see if all (non-constructor, non-destructor) member
1811 functions are private. (Since there are no friends or
1812 non-private statics, we can't ever call any of the private member
1813 functions.) */
1815 /* We're not interested in compiler-generated methods; they don't
1816 provide any way to call private members. */
1818 {
1820 {
1822 /* A non-private static member function is just like a
1823 friend; it can create and invoke private member
1824 functions, and be accessed without a class
1825 instance. */
1829 /* Keep searching for a static member function. */
1830 }
1833 }
1836 {
1837 /* There are no non-private methods, and there's at least one
1838 private member function that isn't a constructor or
1839 destructor. (If all the private members are
1840 constructors/destructors we want to use the code below that
1841 issues error messages specifically referring to
1842 constructors/destructors.) */
1848 {
1851 }
1853 {
1857 }
1858 }
1860 /* Even if some of the member functions are non-private, the class
1861 won't be useful for much if all the constructors or destructors
1862 are private: such an object can never be created or destroyed. */
1865 {
1868 t);
1870 }
1872 /* Warn about classes that have private constructors and no friends. */
1874 /* Implicitly generated constructors are always public. */
1877 {
1880 /* If a non-template class does not define a copy
1881 constructor, one is defined for it, enabling it to avoid
1882 this warning. For a template class, this does not
1883 happen, and so we would normally get a warning on:
1885 template <class T> class C { private: C(); };
1887 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1888 complete non-template or fully instantiated classes have this
1889 flag set. */
1892 else
1894 {
1896 /* Ideally, we wouldn't count copy constructors (or, in
1897 fact, any constructor that takes an argument of the
1898 class type as a parameter) because such things cannot
1899 be used to construct an instance of the class unless
1900 you already have one. But, for now at least, we're
1901 more generous. */
1903 {
1906 }
1907 }
1910 {
1913 t);
1915 }
1916 }
1917 }
1920 gt_pointer_operator new_value;
1924 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1926 static int
1928 {
1941 }
1943 /* This routine compares two fields like method_name_cmp but using the
1944 pointer operator in resort_field_decl_data. */
1946 static int
1948 {
1957 {
1964 }
1966 }
1968 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1970 void
1973 gt_pointer_operator new_value,
1975 {
1979 tree fn;
1981 /* The type conversion ops have to live at the front of the vec, so we
1982 can't sort them. */
1990 {
1994 resort_method_name_cmp);
1995 }
1996 }
1998 /* Warn about duplicate methods in fn_fields.
2000 Sort methods that are not special (i.e., constructors, destructors,
2001 and type conversion operators) so that we can find them faster in
2002 search. */
2004 static void
2006 {
2007 tree fn_fields;
2017 /* Clear DECL_IN_AGGR_P for all functions. */
2022 /* Issue warnings about private constructors and such. If there are
2023 no methods, then some public defaults are generated. */
2026 /* The type conversion ops have to live at the front of the vec, so we
2027 can't sort them. */
2036 }
2038 /* Make BINFO's vtable have N entries, including RTTI entries,
2039 vbase and vcall offsets, etc. Set its type and call the back end
2040 to lay it out. */
2042 static void
2044 {
2045 tree atype;
2046 tree vtable;
2051 /* We may have to grow the vtable. */
2054 {
2058 }
2059 }
2061 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2062 have the same signature. */
2064 int
2066 {
2067 /* One destructor overrides another if they are the same kind of
2068 destructor. */
2072 /* But a non-destructor never overrides a destructor, nor vice
2073 versa, nor do different kinds of destructors override
2074 one-another. For example, a complete object destructor does not
2075 override a deleting destructor. */
2084 {
2092 }
2094 }
2096 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2097 subobject. */
2099 static bool
2101 {
2102 tree probe;
2105 {
2109 /* If we meet a virtual base, we can't follow the inheritance
2110 any more. See if the complete type of DERIVED contains
2111 such a virtual base. */
2114 }
2116 }
2119 /* The function for which we are trying to find a final overrider. */
2120 tree fn;
2121 /* The base class in which the function was declared. */
2122 tree declaring_base;
2123 /* The candidate overriders. */
2124 tree candidates;
2125 /* Path to most derived. */
2129 /* Add the overrider along the current path to FFOD->CANDIDATES.
2130 Returns true if an overrider was found; false otherwise. */
2132 static bool
2136 {
2137 tree method;
2139 /* If BINFO is not the most derived type, try a more derived class.
2140 A definition there will overrider a definition here. */
2142 {
2143 depth--;
2147 }
2151 {
2154 /* Remove any candidates overridden by this new function. */
2156 {
2157 /* If *CANDIDATE overrides METHOD, then METHOD
2158 cannot override anything else on the list. */
2161 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2164 else
2166 }
2168 /* Add the new function. */
2171 }
2174 }
2176 /* Called from find_final_overrider via dfs_walk. */
2178 static tree
2180 {
2188 }
2190 static tree
2192 {
2197 }
2199 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2200 FN and whose TREE_VALUE is the binfo for the base where the
2201 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2202 DERIVED) is the base object in which FN is declared. */
2204 static tree
2206 {
2207 find_final_overrider_data ffod;
2209 /* Getting this right is a little tricky. This is valid:
2211 struct S { virtual void f (); };
2212 struct T { virtual void f (); };
2213 struct U : public S, public T { };
2215 even though calling `f' in `U' is ambiguous. But,
2217 struct R { virtual void f(); };
2218 struct S : virtual public R { virtual void f (); };
2219 struct T : virtual public R { virtual void f (); };
2220 struct U : public S, public T { };
2222 is not -- there's no way to decide whether to put `S::f' or
2223 `T::f' in the vtable for `R'.
2225 The solution is to look at all paths to BINFO. If we find
2226 different overriders along any two, then there is a problem. */
2230 /* Determine the depth of the hierarchy. */
2241 /* If there was no winner, issue an error message. */
2246 }
2248 /* Return the index of the vcall offset for FN when TYPE is used as a
2249 virtual base. */
2251 static tree
2253 {
2255 tree_pair_p p;
2263 /* There should always be an appropriate index. */
2265 }
2267 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2268 dominated by T. FN is the old function; VIRTUALS points to the
2269 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2270 of that entry in the list. */
2272 static void
2275 {
2276 tree b;
2277 tree overrider;
2278 tree delta;
2279 tree virtual_base;
2280 tree first_defn;
2286 /* Find the nearest primary base (possibly binfo itself) which defines
2287 this function; this is the class the caller will convert to when
2288 calling FN through BINFO. */
2290 {
2295 /* The nearest definition is from a lost primary. */
2298 }
2301 /* Find the final overrider. */
2304 {
2307 }
2310 /* Check for adjusting covariant return types. */
2318 /* If the overrider is invalid, don't even try. */
2320 {
2321 /* If FN is a covariant thunk, we must figure out the adjustment
2322 to the final base FN was converting to. As OVERRIDER_TARGET might
2323 also be converting to the return type of FN, we have to
2324 combine the two conversions here. */
2331 {
2335 }
2336 else
2340 /* Find the equivalent binfo within the return type of the
2341 overriding function. We will want the vbase offset from
2342 there. */
2344 over_return);
2347 {
2348 /* There was no existing virtual thunk (which takes
2349 precedence). So find the binfo of the base function's
2350 return type within the overriding function's return type.
2351 We cannot call lookup base here, because we're inside a
2352 dfs_walk, and will therefore clobber the BINFO_MARKED
2353 flags. Fortunately we know the covariancy is valid (it
2354 has already been checked), so we can just iterate along
2355 the binfos, which have been chained in inheritance graph
2356 order. Of course it is lame that we have to repeat the
2357 search here anyway -- we should really be caching pieces
2358 of the vtable and avoiding this repeated work. */
2361 /* Find the base binfo within the overriding function's
2362 return type. We will always find a thunk_binfo, except
2363 when the covariancy is invalid (which we will have
2364 already diagnosed). */
2367 thunk_binfo;
2373 /* See if virtual inheritance is involved. */
2375 virtual_offset;
2382 {
2386 {
2387 /* We convert via virtual base. Adjust the fixed
2388 offset to be from there. */
2389 offset =
2393 }
2395 /* There was an existing fixed offset, this must be
2396 from the base just converted to, and the base the
2397 FN was thunking to. */
2399 else
2401 }
2402 }
2405 /* Replace the overriding function with a covariant thunk. We
2406 will emit the overriding function in its own slot as
2407 well. */
2410 }
2411 else
2415 /* If we need a covariant thunk, then we may need to adjust first_defn.
2416 The ABI specifies that the thunks emitted with a function are
2417 determined by which bases the function overrides, so we need to be
2418 sure that we're using a thunk for some overridden base; even if we
2419 know that the necessary this adjustment is zero, there may not be an
2420 appropriate zero-this-adjusment thunk for us to use since thunks for
2421 overriding virtual bases always use the vcall offset.
2423 Furthermore, just choosing any base that overrides this function isn't
2424 quite right, as this slot won't be used for calls through a type that
2425 puts a covariant thunk here. Calling the function through such a type
2426 will use a different slot, and that slot is the one that determines
2427 the thunk emitted for that base.
2429 So, keep looking until we find the base that we're really overriding
2430 in this slot: the nearest primary base that doesn't use a covariant
2431 thunk in this slot. */
2433 {
2435 /* We already know that the overrider needs a covariant thunk. */
2438 {
2445 }
2447 }
2449 /* Assume that we will produce a thunk that convert all the way to
2450 the final overrider, and not to an intermediate virtual base. */
2453 /* See if we can convert to an intermediate virtual base first, and then
2454 use the vcall offset located there to finish the conversion. */
2456 {
2457 /* If we find the final overrider, then we can stop
2458 walking. */
2463 /* If we find a virtual base, and we haven't yet found the
2464 overrider, then there is a virtual base between the
2465 declaring base (first_defn) and the final overrider. */
2467 {
2470 }
2471 }
2473 /* Compute the constant adjustment to the `this' pointer. The
2474 `this' pointer, when this function is called, will point at BINFO
2475 (or one of its primary bases, which are at the same offset). */
2477 /* The `this' pointer needs to be adjusted from the declaration to
2478 the nearest virtual base. */
2483 /* If the nearest definition is in a lost primary, we don't need an
2484 entry in our vtable. Except possibly in a constructor vtable,
2485 if we happen to get our primary back. In that case, the offset
2486 will be zero, as it will be a primary base. */
2488 else
2489 /* The `this' pointer needs to be adjusted from pointing to
2490 BINFO to pointing at the base where the final overrider
2491 appears. */
2502 else
2506 }
2508 /* Called from modify_all_vtables via dfs_walk. */
2510 static tree
2512 {
2514 tree virtuals;
2515 tree old_virtuals;
2519 /* A base without a vtable needs no modification, and its bases
2520 are uninteresting. */
2525 /* Don't do the primary vtable, if it's new. */
2529 /* There's no need to modify the vtable for a non-virtual primary
2530 base; we're not going to use that vtable anyhow. We do still
2531 need to do this for virtual primary bases, as they could become
2532 non-primary in a construction vtable. */
2537 /* Now, go through each of the virtual functions in the virtual
2538 function table for BINFO. Find the final overrider, and update
2539 the BINFO_VIRTUALS list appropriately. */
2542 virtuals;
2546 binfo,
2551 }
2553 /* Update all of the primary and secondary vtables for T. Create new
2554 vtables as required, and initialize their RTTI information. Each
2555 of the functions in VIRTUALS is declared in T and may override a
2556 virtual function from a base class; find and modify the appropriate
2557 entries to point to the overriding functions. Returns a list, in
2558 declaration order, of the virtual functions that are declared in T,
2559 but do not appear in the primary base class vtable, and which
2560 should therefore be appended to the end of the vtable for T. */
2562 static tree
2564 {
2568 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2572 /* Update all of the vtables. */
2575 /* Add virtual functions not already in our primary vtable. These
2576 will be both those introduced by this class, and those overridden
2577 from secondary bases. It does not include virtuals merely
2578 inherited from secondary bases. */
2580 {
2585 {
2586 /* We don't need to adjust the `this' pointer when
2587 calling this function. */
2591 /* This is a function not already in our vtable. Keep it. */
2593 }
2594 else
2595 /* We've already got an entry for this function. Skip it. */
2597 }
2600 }
2602 /* Get the base virtual function declarations in T that have the
2603 indicated NAME. */
2605 static tree
2607 {
2608 tree methods;
2613 /* Find virtual functions in T with the indicated NAME. */
2617 methods;
2619 {
2625 }
2631 {
2634 base_fndecls);
2635 }
2638 }
2640 /* If this declaration supersedes the declaration of
2641 a method declared virtual in the base class, then
2642 mark this field as being virtual as well. */
2644 void
2646 {
2649 /* In [temp.mem] we have:
2651 A specialization of a member function template does not
2652 override a virtual function from a base class. */
2659 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2660 the error_mark_node so that we know it is an overriding
2661 function. */
2662 {
2665 }
2668 {
2674 }
2679 }
2681 /* Warn about hidden virtual functions that are not overridden in t.
2682 We know that constructors and destructors don't apply. */
2684 static void
2686 {
2688 tree fns;
2691 /* We go through each separately named virtual function. */
2695 {
2696 tree fn;
2697 tree name;
2698 tree fndecl;
2699 tree base_fndecls;
2700 tree base_binfo;
2701 tree binfo;
2704 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2705 have the same name. Figure out what name that is. */
2707 /* There are no possibly hidden functions yet. */
2709 /* Iterate through all of the base classes looking for possibly
2710 hidden functions. */
2713 {
2716 base_fndecls);
2717 }
2719 /* If there are no functions to hide, continue. */
2723 /* Remove any overridden functions. */
2725 {
2728 {
2732 /* If the method from the base class has the same
2733 signature as the method from the derived class, it
2734 has been overridden. */
2737 else
2739 }
2740 }
2742 /* Now give a warning for all base functions without overriders,
2743 as they are hidden. */
2745 {
2746 /* Here we know it is a hider, and no overrider exists. */
2750 }
2751 }
2752 }
2754 /* Check for things that are invalid. There are probably plenty of other
2755 things we should check for also. */
2757 static void
2759 {
2760 tree field;
2763 {
2771 {
2775 {
2776 /* We're generally only interested in entities the user
2777 declared, but we also find nested classes by noticing
2778 the TYPE_DECL that we create implicitly. You're
2779 allowed to put one anonymous union inside another,
2780 though, so we explicitly tolerate that. We use
2781 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2782 we also allow unnamed types used for defining fields. */
2789 {
2793 else
2797 }
2800 {
2803 else
2805 }
2807 {
2810 else
2812 }
2816 }
2817 }
2818 }
2819 }
2821 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2822 will be used later during class template instantiation.
2823 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2824 a non-static member data (FIELD_DECL), a member function
2825 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2826 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2827 When FRIEND_P is nonzero, T is either a friend class
2828 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2829 (FUNCTION_DECL, TEMPLATE_DECL). */
2831 void
2833 {
2834 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2839 }
2841 /* This function is called from declare_virt_assop_and_dtor via
2842 dfs_walk_all.
2844 DATA is a type that direcly or indirectly inherits the base
2845 represented by BINFO. If BINFO contains a virtual assignment [copy
2846 assignment or move assigment] operator or a virtual constructor,
2847 declare that function in DATA if it hasn't been already declared. */
2849 static tree
2851 {
2859 /* A base without a vtable needs no modification, and its bases
2860 are uninteresting. */
2864 /* If this is a primary base, then we have already looked at the
2865 virtual functions of its vtable. */
2869 {
2873 {
2878 }
2882 }
2885 }
2887 /* If the class type T has a direct or indirect base that contains a
2888 virtual assignment operator or a virtual destructor, declare that
2889 function in T if it hasn't been already declared. */
2891 static void
2893 {
2901 dfs_declare_virt_assop_and_dtor,
2903 }
2905 /* Declare the inheriting constructor for class T inherited from base
2906 constructor CTOR with the parameter array PARMS of size NPARMS. */
2908 static void
2910 {
2911 /* We don't declare an inheriting ctor that would be a default,
2912 copy or move ctor for derived or base. */
2917 {
2921 }
2929 {
2932 }
2933 }
2935 /* Declare all the inheriting constructors for class T inherited from base
2936 constructor CTOR. */
2938 static void
2940 {
2946 {
2950 }
2953 {
2957 }
2958 }
2960 /* Create default constructors, assignment operators, and so forth for
2961 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2962 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2963 the class cannot have a default constructor, copy constructor
2964 taking a const reference argument, or an assignment operator taking
2965 a const reference, respectively. */
2967 static void
2971 {
2979 /* Destructor. */
2981 {
2982 /* In general, we create destructors lazily. */
2987 /* But if this is a Java class, any non-trivial destructor is
2988 invalid, even if compiler-generated. Therefore, if the
2989 destructor is non-trivial we create it now. */
2991 }
2993 /* [class.ctor]
2995 If there is no user-declared constructor for a class, a default
2996 constructor is implicitly declared. */
2998 {
3003 /* This might force the declaration. */
3005 }
3007 /* [class.ctor]
3009 If a class definition does not explicitly declare a copy
3010 constructor, one is declared implicitly. */
3012 {
3018 }
3020 /* If there is no assignment operator, one will be created if and
3021 when it is needed. For now, just record whether or not the type
3022 of the parameter to the assignment operator will be a const or
3023 non-const reference. */
3025 {
3031 }
3033 /* We can't be lazy about declaring functions that might override
3034 a virtual function from a base class. */
3038 {
3042 {
3043 /* declare, then remove the decl */
3052 }
3053 else
3055 }
3056 }
3058 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3059 count the number of fields in TYPE, including anonymous union
3060 members. */
3062 static int
3064 {
3065 tree x;
3068 {
3071 else
3073 }
3075 }
3077 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3078 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3079 elts, starting at offset IDX. */
3081 static int
3083 {
3084 tree x;
3086 {
3089 else
3091 }
3093 }
3095 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3096 starting at offset IDX. */
3098 static int
3102 {
3103 tree values;
3107 }
3109 /* FIELD is a bit-field. We are finishing the processing for its
3110 enclosing type. Issue any appropriate messages and set appropriate
3111 flags. Returns false if an error has been diagnosed. */
3113 static bool
3115 {
3117 tree w;
3119 /* Extract the declared width of the bitfield, which has been
3120 temporarily stashed in DECL_INITIAL. */
3123 /* Remove the bit-field width indicator so that the rest of the
3124 compiler does not treat that value as an initializer. */
3127 /* Detect invalid bit-field type. */
3129 {
3132 }
3133 else
3134 {
3136 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3139 /* detect invalid field size. */
3145 {
3148 }
3150 {
3153 }
3155 {
3158 }
3170 }
3173 {
3177 }
3178 else
3179 {
3180 /* Non-bit-fields are aligned for their type. */
3184 }
3185 }
3187 /* FIELD is a non bit-field. We are finishing the processing for its
3188 enclosing type T. Issue any appropriate messages and set appropriate
3189 flags. */
3191 static void
3193 tree t,
3197 {
3200 /* In C++98 an anonymous union cannot contain any fields which would change
3201 the settings of CANT_HAVE_CONST_CTOR and friends. */
3203 ;
3204 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3205 structs. So, we recurse through their fields here. */
3207 {
3208 tree fields;
3214 }
3215 /* Check members with class type for constructors, destructors,
3216 etc. */
3218 {
3219 /* Never let anything with uninheritable virtuals
3220 make it through without complaint. */
3224 {
3229 field);
3234 field);
3236 {
3240 }
3241 }
3242 else
3243 {
3256 }
3265 }
3270 {
3271 /* `build_class_init_list' does not recognize
3272 non-FIELD_DECLs. */
3276 }
3277 }
3279 /* Check the data members (both static and non-static), class-scoped
3280 typedefs, etc., appearing in the declaration of T. Issue
3281 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3282 declaration order) of access declarations; each TREE_VALUE in this
3283 list is a USING_DECL.
3285 In addition, set the following flags:
3287 EMPTY_P
3288 The class is empty, i.e., contains no non-static data members.
3290 CANT_HAVE_CONST_CTOR_P
3291 This class cannot have an implicitly generated copy constructor
3292 taking a const reference.
3294 CANT_HAVE_CONST_ASN_REF
3295 This class cannot have an implicitly generated assignment
3296 operator taking a const reference.
3298 All of these flags should be initialized before calling this
3299 function.
3301 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3302 fields can be added by adding to this chain. */
3304 static void
3308 {
3316 /* Assume there are no access declarations. */
3318 /* Assume this class has no pointer members. */
3320 /* Assume none of the members of this class have default
3321 initializations. */
3325 {
3333 {
3334 /* Save the access declarations for our caller. */
3337 }
3343 /* If we've gotten this far, it's a data member, possibly static,
3344 or an enumerator. */
3348 /* When this goes into scope, it will be a non-local reference. */
3352 {
3353 /* [class.union]
3355 If a union contains a static data member, or a member of
3356 reference type, the program is ill-formed. */
3358 {
3361 }
3363 {
3368 }
3369 }
3371 /* Perform error checking that did not get done in
3372 grokdeclarator. */
3374 {
3378 }
3380 {
3384 }
3392 /* Now it can only be a FIELD_DECL. */
3397 /* If at least one non-static data member is non-literal, the whole
3398 class becomes non-literal. Note: if the type is incomplete we
3399 will complain later on. */
3403 /* A standard-layout class is a class that:
3404 ...
3405 has the same access control (Clause 11) for all non-static data members,
3406 ... */
3413 /* If this is of reference type, check if it needs an init. */
3415 {
3421 /* ARM $12.6.2: [A member initializer list] (or, for an
3422 aggregate, initialization by a brace-enclosed list) is the
3423 only way to initialize nonstatic const and reference
3424 members. */
3427 }
3432 {
3434 {
3435 warning
3438 x);
3440 }
3444 }
3447 /* We don't treat zero-width bitfields as making a class
3448 non-empty. */
3449 ;
3450 else
3451 {
3452 /* The class is non-empty. */
3454 /* The class is not even nearly empty. */
3456 /* If one of the data members contains an empty class,
3457 so does T. */
3461 }
3463 /* This is used by -Weffc++ (see below). Warn only for pointers
3464 to members which might hold dynamic memory. So do not warn
3465 for pointers to functions or pointers to members. */
3471 {
3476 }
3482 /* DR 148 now allows pointers to members (which are POD themselves),
3483 to be allowed in POD structs. */
3492 /* We set DECL_C_BIT_FIELD in grokbitfield.
3493 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3496 cant_have_const_ctor_p,
3497 no_const_asn_ref_p,
3500 /* Now that we've removed bit-field widths from DECL_INITIAL,
3501 anything left in DECL_INITIAL is an NSDMI that makes the class
3502 non-aggregate. */
3506 /* If any field is const, the structure type is pseudo-const. */
3508 {
3513 /* ARM $12.6.2: [A member initializer list] (or, for an
3514 aggregate, initialization by a brace-enclosed list) is the
3515 only way to initialize nonstatic const and reference
3516 members. */
3519 }
3520 /* A field that is pseudo-const makes the structure likewise. */
3522 {
3527 }
3529 /* Core issue 80: A nonstatic data member is required to have a
3530 different name from the class iff the class has a
3531 user-declared constructor. */
3535 }
3537 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3538 it should also define a copy constructor and an assignment operator to
3539 implement the correct copy semantic (deep vs shallow, etc.). As it is
3540 not feasible to check whether the constructors do allocate dynamic memory
3541 and store it within members, we approximate the warning like this:
3543 -- Warn only if there are members which are pointers
3544 -- Warn only if there is a non-trivial constructor (otherwise,
3545 there cannot be memory allocated).
3546 -- Warn only if there is a non-trivial destructor. We assume that the
3547 user at least implemented the cleanup correctly, and a destructor
3548 is needed to free dynamic memory.
3550 This seems enough for practical purposes. */
3552 && has_pointers
3556 {
3560 {
3565 }
3569 }
3571 /* Non-static data member initializers make the default constructor
3572 non-trivial. */
3574 {
3577 }
3579 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3583 /* Check anonymous struct/anonymous union fields. */
3586 /* We've built up the list of access declarations in reverse order.
3587 Fix that now. */
3589 }
3591 /* If TYPE is an empty class type, records its OFFSET in the table of
3592 OFFSETS. */
3594 static int
3596 {
3597 splay_tree_node n;
3602 /* Record the location of this empty object in OFFSETS. */
3610 type,
3614 }
3616 /* Returns nonzero if TYPE is an empty class type and there is
3617 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3619 static int
3621 {
3622 splay_tree_node n;
3623 tree t;
3628 /* Record the location of this empty object in OFFSETS. */
3638 }
3640 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3641 F for every subobject, passing it the type, offset, and table of
3642 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3643 be traversed.
3645 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3646 than MAX_OFFSET will not be walked.
3648 If F returns a nonzero value, the traversal ceases, and that value
3649 is returned. Otherwise, returns zero. */
3651 static int
3653 subobject_offset_fn f,
3654 tree offset,
3655 splay_tree offsets,
3656 tree max_offset,
3658 {
3662 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3663 stop. */
3671 {
3675 }
3678 {
3679 tree field;
3680 tree binfo;
3683 /* Avoid recursing into objects that are not interesting. */
3687 /* Record the location of TYPE. */
3692 /* Iterate through the direct base classes of TYPE. */
3696 {
3697 tree binfo_offset;
3710 offset,
3712 else
3713 {
3714 tree orig_binfo;
3715 /* We cannot rely on BINFO_OFFSET being set for the base
3716 class yet, but the offsets for direct non-virtual
3717 bases can be calculated by going back to the TYPE. */
3720 offset,
3722 }
3725 f,
3726 binfo_offset,
3727 offsets,
3728 max_offset,
3733 }
3736 {
3740 /* Iterate through the virtual base classes of TYPE. In G++
3741 3.2, we included virtual bases in the direct base class
3742 loop above, which results in incorrect results; the
3743 correct offsets for virtual bases are only known when
3744 working with the most derived type. */
3748 {
3750 f,
3752 offset,
3754 offsets,
3755 max_offset,
3759 }
3760 else
3761 {
3762 /* We still have to walk the primary base, if it is
3763 virtual. (If it is non-virtual, then it was walked
3764 above.) */
3770 {
3771 r = (walk_subobject_offsets
3776 }
3777 }
3778 }
3780 /* Iterate through the fields of TYPE. */
3785 {
3786 tree field_offset;
3790 else
3791 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3795 f,
3797 offset,
3798 field_offset),
3799 offsets,
3800 max_offset,
3804 }
3805 }
3807 {
3810 tree index;
3812 /* Avoid recursing into objects that are not interesting. */
3817 /* Step through each of the elements in the array. */
3819 /* G++ 3.2 had an off-by-one error here. */
3824 {
3826 f,
3827 offset,
3828 offsets,
3829 max_offset,
3835 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3836 there's no point in iterating through the remaining
3837 elements of the array. */
3840 }
3841 }
3844 }
3846 /* Record all of the empty subobjects of TYPE (either a type or a
3847 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3848 is being placed at OFFSET; otherwise, it is a base class that is
3849 being placed at OFFSET. */
3851 static void
3853 tree offset,
3854 splay_tree offsets,
3856 {
3857 tree max_offset;
3858 /* If recording subobjects for a non-static data member or a
3859 non-empty base class , we do not need to record offsets beyond
3860 the size of the biggest empty class. Additional data members
3861 will go at the end of the class. Additional base classes will go
3862 either at offset zero (if empty, in which case they cannot
3863 overlap with offsets past the size of the biggest empty class) or
3864 at the end of the class.
3866 However, if we are placing an empty base class, then we must record
3867 all offsets, as either the empty class is at offset zero (where
3868 other empty classes might later be placed) or at the end of the
3869 class (where other objects might then be placed, so other empty
3870 subobjects might later overlap). */
3874 else
3878 }
3880 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3881 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3882 virtual bases of TYPE are examined. */
3884 static int
3886 tree offset,
3887 splay_tree offsets,
3889 {
3890 splay_tree_node max_node;
3892 /* Get the node in OFFSETS that indicates the maximum offset where
3893 an empty subobject is located. */
3895 /* If there aren't any empty subobjects, then there's no point in
3896 performing this check. */
3902 vbases_p);
3903 }
3905 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3906 non-static data member of the type indicated by RLI. BINFO is the
3907 binfo corresponding to the base subobject, OFFSETS maps offsets to
3908 types already located at those offsets. This function determines
3909 the position of the DECL. */
3911 static void
3913 tree decl,
3914 tree binfo,
3915 splay_tree offsets)
3916 {
3919 tree type;
3922 {
3923 /* For the purposes of determining layout conflicts, we want to
3924 use the class type of BINFO; TREE_TYPE (DECL) will be the
3925 CLASSTYPE_AS_BASE version, which does not contain entries for
3926 zero-sized bases. */
3929 }
3930 else
3931 {
3934 }
3936 /* Try to place the field. It may take more than one try if we have
3937 a hard time placing the field without putting two objects of the
3938 same type at the same address. */
3940 {
3943 /* Place this field. */
3947 /* We have to check to see whether or not there is already
3948 something of the same type at the offset we're about to use.
3949 For example, consider:
3951 struct S {};
3952 struct T : public S { int i; };
3953 struct U : public S, public T {};
3955 Here, we put S at offset zero in U. Then, we can't put T at
3956 offset zero -- its S component would be at the same address
3957 as the S we already allocated. So, we have to skip ahead.
3958 Since all data members, including those whose type is an
3959 empty class, have nonzero size, any overlap can happen only
3960 with a direct or indirect base-class -- it can't happen with
3961 a data member. */
3962 /* In a union, overlap is permitted; all members are placed at
3963 offset zero. */
3966 /* G++ 3.2 did not check for overlaps when placing a non-empty
3967 virtual base. */
3972 {
3973 /* Strip off the size allocated to this field. That puts us
3974 at the first place we could have put the field with
3975 proper alignment. */
3978 /* Bump up by the alignment required for the type. */
3979 rli->bitpos
3985 }
3986 else
3987 /* There was no conflict. We're done laying out this field. */
3989 }
3991 /* Now that we know where it will be placed, update its
3992 BINFO_OFFSET. */
3994 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3995 this point because their BINFO_OFFSET is copied from another
3996 hierarchy. Therefore, we may not need to add the entire
3997 OFFSET. */
4003 }
4005 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4007 static int
4009 tree offset,
4011 {
4013 }
4015 /* Layout the empty base BINFO. EOC indicates the byte currently just
4016 past the end of the class, and should be correctly aligned for a
4017 class of the type indicated by BINFO; OFFSETS gives the offsets of
4018 the empty bases allocated so far. T is the most derived
4019 type. Return nonzero iff we added it at the end. */
4021 static bool
4024 {
4025 tree alignment;
4029 /* This routine should only be used for empty classes. */
4034 {
4036 propagate_binfo_offsets
4039 else
4041 "offset of empty base %qT may not be ABI-compliant and may"
4044 }
4046 /* This is an empty base class. We first try to put it at offset
4047 zero. */
4050 offsets,
4052 {
4053 /* That didn't work. Now, we move forward from the next
4054 available spot in the class. */
4058 {
4061 offsets,
4063 /* We finally found a spot where there's no overlap. */
4066 /* There's overlap here, too. Bump along to the next spot. */
4068 }
4069 }
4072 {
4077 }
4080 }
4082 /* Layout the base given by BINFO in the class indicated by RLI.
4083 *BASE_ALIGN is a running maximum of the alignments of
4084 any base class. OFFSETS gives the location of empty base
4085 subobjects. T is the most derived type. Return nonzero if the new
4086 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4087 *NEXT_FIELD, unless BINFO is for an empty base class.
4089 Returns the location at which the next field should be inserted. */
4094 {
4099 /* This error is now reported in xref_tag, thus giving better
4100 location information. */
4103 /* Place the base class. */
4105 {
4106 tree decl;
4108 /* The containing class is non-empty because it has a non-empty
4109 base class. */
4112 /* Create the FIELD_DECL. */
4119 {
4127 /* Try to place the field. It may take more than one try if we
4128 have a hard time placing the field without putting two
4129 objects of the same type at the same address. */
4131 /* Add the new FIELD_DECL to the list of fields for T. */
4135 }
4136 }
4137 else
4138 {
4139 tree eoc;
4142 /* On some platforms (ARM), even empty classes will not be
4143 byte-aligned. */
4148 /* A nearly-empty class "has no proper base class that is empty,
4149 not morally virtual, and at an offset other than zero." */
4151 {
4154 /* The check above (used in G++ 3.2) is insufficient because
4155 an empty class placed at offset zero might itself have an
4156 empty base at a nonzero offset. */
4158 empty_base_at_nonzero_offset_p,
4159 size_zero_node,
4163 {
4166 else
4168 "class %qT will be considered nearly empty in a "
4170 }
4171 }
4173 /* We do not create a FIELD_DECL for empty base classes because
4174 it might overlap some other field. We want to be able to
4175 create CONSTRUCTORs for the class by iterating over the
4176 FIELD_DECLs, and the back end does not handle overlapping
4177 FIELD_DECLs. */
4179 /* An empty virtual base causes a class to be non-empty
4180 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4181 here because that was already done when the virtual table
4182 pointer was created. */
4183 }
4185 /* Record the offsets of BINFO and its base subobjects. */
4188 offsets,
4192 }
4194 /* Layout all of the non-virtual base classes. Record empty
4195 subobjects in OFFSETS. T is the most derived type. Return nonzero
4196 if the type cannot be nearly empty. The fields created
4197 corresponding to the base classes will be inserted at
4198 *NEXT_FIELD. */
4200 static void
4203 {
4204 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4205 subobjects. */
4210 /* The primary base class is always allocated first. */
4215 /* Now allocate the rest of the bases. */
4217 {
4218 tree base_binfo;
4222 /* The primary base was already allocated above, so we don't
4223 need to allocate it again here. */
4227 /* Virtual bases are added at the end (a primary virtual base
4228 will have already been added). */
4234 }
4235 }
4237 /* Go through the TYPE_METHODS of T issuing any appropriate
4238 diagnostics, figuring out which methods override which other
4239 methods, and so forth. */
4241 static void
4243 {
4244 tree x;
4247 {
4251 /* The name of the field is the original field name
4252 Save this in auxiliary field for later overloading. */
4254 {
4258 }
4259 /* All user-provided destructors are non-trivial.
4260 Constructors and assignment ops are handled in
4261 grok_special_member_properties. */
4264 }
4265 }
4267 /* FN is a constructor or destructor. Clone the declaration to create
4268 a specialized in-charge or not-in-charge version, as indicated by
4269 NAME. */
4271 static tree
4273 {
4274 tree parms;
4275 tree clone;
4277 /* Copy the function. */
4279 /* Reset the function name. */
4282 /* Remember where this function came from. */
4284 /* Make it easy to find the CLONE given the FN. */
4288 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4290 {
4297 }
4300 /* There's no pending inline data for this function. */
4304 /* The base-class destructor is not virtual. */
4306 {
4310 }
4312 /* If there was an in-charge parameter, drop it from the function
4313 type. */
4315 {
4316 tree basetype;
4317 tree parmtypes;
4318 tree exceptions;
4323 /* Skip the `this' parameter. */
4325 /* Skip the in-charge parameter. */
4327 /* And the VTT parm, in a complete [cd]tor. */
4331 /* If this is subobject constructor or destructor, add the vtt
4332 parameter. */
4336 parmtypes);
4339 exceptions);
4343 }
4345 /* Copy the function parameters. */
4347 /* Remove the in-charge parameter. */
4349 {
4353 }
4354 /* And the VTT parm, in a complete [cd]tor. */
4356 {
4359 else
4360 {
4364 }
4365 }
4368 {
4371 }
4373 /* Create the RTL for this function. */
4381 }
4383 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4384 not invoke this function directly.
4386 For a non-thunk function, returns the address of the slot for storing
4387 the function it is a clone of. Otherwise returns NULL_TREE.
4389 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4390 cloned_function is unset. This is to support the separate
4391 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4392 on a template makes sense, but not the former. */
4394 tree *
4396 {
4404 {
4405 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4408 else
4409 #endif
4411 }
4416 else
4418 }
4420 /* Produce declarations for all appropriate clones of FN. If
4421 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4422 CLASTYPE_METHOD_VEC as well. */
4424 void
4426 {
4427 tree clone;
4429 /* Avoid inappropriate cloning. */
4435 {
4436 /* For each constructor, we need two variants: an in-charge version
4437 and a not-in-charge version. */
4444 }
4445 else
4446 {
4449 /* For each destructor, we need three variants: an in-charge
4450 version, a not-in-charge version, and an in-charge deleting
4451 version. We clone the deleting version first because that
4452 means it will go second on the TYPE_METHODS list -- and that
4453 corresponds to the correct layout order in the virtual
4454 function table.
4456 For a non-virtual destructor, we do not build a deleting
4457 destructor. */
4459 {
4463 }
4470 }
4472 /* Note that this is an abstract function that is never emitted. */
4474 }
4476 /* DECL is an in charge constructor, which is being defined. This will
4477 have had an in class declaration, from whence clones were
4478 declared. An out-of-class definition can specify additional default
4479 arguments. As it is the clones that are involved in overload
4480 resolution, we must propagate the information from the DECL to its
4481 clones. */
4483 void
4485 {
4486 tree clone;
4490 {
4497 /* Skip the 'this' parameter. */
4513 {
4518 {
4519 /* A default parameter has been added. Adjust the
4520 clone's parameters. */
4524 tree type;
4529 {
4532 clone_parms);
4534 }
4537 clone_parms);
4546 }
4547 }
4549 }
4550 }
4552 /* For each of the constructors and destructors in T, create an
4553 in-charge and not-in-charge variant. */
4555 static void
4557 {
4558 tree fns;
4560 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4561 out now. */
4569 }
4571 /* Deduce noexcept for a destructor DTOR. */
4573 void
4575 {
4577 {
4584 }
4585 }
4587 /* For each destructor in T, deduce noexcept:
4589 12.4/3: A declaration of a destructor that does not have an
4590 exception-specification is implicitly considered to have the
4591 same exception-specification as an implicit declaration (15.4). */
4593 static void
4595 {
4596 tree fns;
4598 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4599 out now. */
4605 }
4607 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4608 of TYPE for virtual functions which FNDECL overrides. Return a
4609 mask of the tm attributes found therein. */
4611 static int
4613 {
4615 tree base_binfo;
4619 {
4629 else
4631 }
4634 }
4636 /* Subroutine of set_method_tm_attributes. Handle the checks and
4637 inheritance for one virtual method FNDECL. */
4639 static void
4641 {
4642 tree tm_attr;
4647 /* If FNDECL doesn't actually override anything (i.e. T is the
4648 class that first declares FNDECL virtual), then we're done. */
4655 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4656 tm_pure must match exactly, otherwise no weakening of
4657 tm_safe > tm_callable > nothing. */
4658 /* ??? The tm_pure attribute didn't make the transition to the
4659 multivendor language spec. */
4661 {
4663 {
4666 }
4667 }
4668 /* If the overridden function is tm_pure, then FNDECL must be. */
4671 /* Look for base class combinations that cannot be satisfied. */
4673 {
4679 }
4680 /* If FNDECL did not declare an attribute, then inherit the most
4681 restrictive one. */
4683 {
4685 }
4686 /* Otherwise validate that we're not weaker than a function
4687 that is being overridden. */
4688 else
4689 {
4693 }
4696 err_override:
4700 }
4702 /* For each of the methods in T, propagate a class-level tm attribute. */
4704 static void
4706 {
4709 /* Don't bother collecting tm attributes if transactional memory
4710 support is not enabled. */
4714 /* Process virtual methods first, as they inherit directly from the
4715 base virtual function and also require validation of new attributes. */
4717 {
4718 tree vchain;
4721 {
4726 }
4727 }
4729 /* If the class doesn't have an attribute, nothing more to do. */
4734 /* Any method that does not yet have a tm attribute inherits
4735 the one from the class. */
4737 {
4740 }
4741 }
4743 /* Returns true iff class T has a user-defined constructor other than
4744 the default constructor. */
4746 bool
4748 {
4749 tree fns;
4755 {
4762 }
4765 }
4767 /* Returns the defaulted constructor if T has one. Otherwise, returns
4768 NULL_TREE. */
4770 tree
4772 {
4779 {
4783 {
4789 }
4790 }
4793 }
4795 /* Returns true iff FN is a user-provided function, i.e. user-declared
4796 and not defaulted at its first declaration; or explicit, private,
4797 protected, or non-const. */
4799 bool
4801 {
4804 else
4807 }
4809 /* Returns true iff class T has a user-provided constructor. */
4811 bool
4813 {
4814 tree fns;
4822 /* This can happen in error cases; avoid crashing. */
4831 }
4833 /* Returns true iff class T has a user-provided default constructor. */
4835 bool
4837 {
4838 tree fns;
4844 {
4850 }
4853 }
4855 /* TYPE is being used as a virtual base, and has a non-trivial move
4856 assignment. Return true if this is due to there being a user-provided
4857 move assignment in TYPE or one of its subobjects; if there isn't, then
4858 multiple move assignment can't cause any harm. */
4860 bool
4862 {
4863 /* Does the type itself have a user-provided move assignment operator? */
4867 {
4871 }
4873 /* Do any of its bases? */
4875 tree base_binfo;
4880 /* Or non-static data members? */
4882 {
4887 }
4889 /* Seems not. */
4891 }
4893 /* If default-initialization leaves part of TYPE uninitialized, returns
4894 a DECL for the field or TYPE itself (DR 253). */
4896 tree
4898 {
4909 {
4913 }
4918 {
4922 }
4925 }
4927 /* Returns true iff for class T, a trivial synthesized default constructor
4928 would be constexpr. */
4930 bool
4932 {
4933 /* A defaulted trivial default constructor is constexpr
4934 if there is nothing to initialize. */
4937 }
4939 /* Returns true iff class T has a constexpr default constructor. */
4941 bool
4943 {
4944 tree fns;
4947 {
4948 /* The caller should have stripped an enclosing array. */
4951 }
4953 {
4956 /* Non-trivial, we need to check subobject constructors. */
4958 }
4961 }
4963 /* Returns true iff class TYPE has a virtual destructor. */
4965 bool
4967 {
4968 tree dtor;
4976 }
4978 /* Returns true iff class T has a move constructor. */
4980 bool
4982 {
4983 tree fns;
4986 {
4989 }
4999 }
5001 /* Returns true iff class T has a move assignment operator. */
5003 bool
5005 {
5006 tree fns;
5009 {
5012 }
5020 }
5022 /* Returns true iff class T has a move constructor that was explicitly
5023 declared in the class body. Note that this is different from
5024 "user-provided", which doesn't include functions that are defaulted in
5025 the class. */
5027 bool
5029 {
5030 tree fns;
5039 {
5043 }
5046 }
5048 /* Returns true iff class T has a move assignment operator that was
5049 explicitly declared in the class body. */
5051 bool
5053 {
5054 tree fns;
5061 {
5065 }
5068 }
5070 /* Nonzero if we need to build up a constructor call when initializing an
5071 object of this class, either because it has a user-provided constructor
5072 or because it doesn't have a default constructor (so we need to give an
5073 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5074 what you care about is whether or not an object can be produced by a
5075 constructor (e.g. so we don't set TREE_READONLY on const variables of
5076 such type); use this function when what you care about is whether or not
5077 to try to call a constructor to create an object. The latter case is
5078 the former plus some cases of constructors that cannot be called. */
5080 bool
5082 {
5083 tree inner;
5089 }
5091 /* Remove all zero-width bit-fields from T. */
5093 static void
5095 {
5100 {
5103 /* We should not be confused by the fact that grokbitfield
5104 temporarily sets the width of the bit field into
5105 DECL_INITIAL (*fieldsp).
5106 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5107 to that width. */
5110 else
5112 }
5113 }
5115 /* Returns TRUE iff we need a cookie when dynamically allocating an
5116 array whose elements have the indicated class TYPE. */
5118 static bool
5120 {
5121 tree fns;
5126 /* If there's a non-trivial destructor, we need a cookie. In order
5127 to iterate through the array calling the destructor for each
5128 element, we'll have to know how many elements there are. */
5132 /* If the usual deallocation function is a two-argument whose second
5133 argument is of type `size_t', then we have to pass the size of
5134 the array to the deallocation function, so we will need to store
5135 a cookie. */
5139 /* If there are no `operator []' members, or the lookup is
5140 ambiguous, then we don't need a cookie. */
5143 /* Loop through all of the functions. */
5145 {
5146 tree fn;
5147 tree second_parm;
5149 /* Select the current function. */
5151 /* See if this function is a one-argument delete function. If
5152 it is, then it will be the usual deallocation function. */
5156 /* Do not consider this function if its second argument is an
5157 ellipsis. */
5160 /* Otherwise, if we have a two-argument function and the second
5161 argument is `size_t', it will be the usual deallocation
5162 function -- unless there is one-argument function, too. */
5166 }
5169 }
5171 /* Finish computing the `literal type' property of class type T.
5173 At this point, we have already processed base classes and
5174 non-static data members. We need to check whether the copy
5175 constructor is trivial, the destructor is trivial, and there
5176 is a trivial default constructor or at least one constexpr
5177 constructor other than the copy constructor. */
5179 static void
5181 {
5182 tree fn;
5198 {
5201 {
5205 }
5206 }
5207 }
5209 /* T is a non-literal type used in a context which requires a constant
5210 expression. Explain why it isn't literal. */
5212 void
5214 {
5224 /* Already explained. */
5233 {
5235 "default constructor, and has no constexpr constructor that "
5239 {
5240 /* Note that we can't simply call locate_ctor because when the
5241 constructor is deleted it just returns NULL_TREE. */
5242 tree fns;
5244 {
5251 {
5254 else
5257 }
5258 }
5259 }
5260 }
5261 else
5262 {
5266 {
5269 {
5274 }
5275 }
5277 {
5278 tree ftype;
5283 {
5288 }
5289 }
5290 }
5291 }
5293 /* Check the validity of the bases and members declared in T. Add any
5294 implicitly-generated functions (like copy-constructors and
5295 assignment operators). Compute various flag bits (like
5296 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5297 level: i.e., independently of the ABI in use. */
5299 static void
5301 {
5302 /* Nonzero if the implicitly generated copy constructor should take
5303 a non-const reference argument. */
5305 /* Nonzero if the implicitly generated assignment operator
5306 should take a non-const reference argument. */
5308 tree access_decls;
5311 tree fn;
5313 /* By default, we use const reference arguments and generate default
5314 constructors. */
5318 /* Check all the base-classes. */
5322 /* Deduce noexcept on destructors. This needs to happen after we've set
5323 triviality flags appropriately for our bases. */
5327 /* Check all the method declarations. */
5330 /* Save the initial values of these flags which only indicate whether
5331 or not the class has user-provided functions. As we analyze the
5332 bases and members we can set these flags for other reasons. */
5336 /* Check all the data member declarations. We cannot call
5337 check_field_decls until we have called check_bases check_methods,
5338 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5339 being set appropriately. */
5344 /* A nearly-empty class has to be vptr-containing; a nearly empty
5345 class contains just a vptr. */
5349 /* Do some bookkeeping that will guide the generation of implicitly
5350 declared member functions. */
5353 /* We need to call a constructor for this class if it has a
5354 user-provided constructor, or if the default constructor is going
5355 to initialize the vptr. (This is not an if-and-only-if;
5356 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5357 themselves need constructing.) */
5360 /* [dcl.init.aggr]
5362 An aggregate is an array or a class with no user-provided
5363 constructors ... and no virtual functions.
5365 Again, other conditions for being an aggregate are checked
5366 elsewhere. */
5369 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5370 retain the old definition internally for ABI reasons. */
5379 /* If the class has no user-declared constructor, but does have
5380 non-static const or reference data members that can never be
5381 initialized, issue a warning. */
5383 /* Classes with user-declared constructors are presumed to
5384 initialize these members. */
5386 /* Aggregates can be initialized with brace-enclosed
5387 initializers. */
5389 {
5390 tree field;
5393 {
5394 tree type;
5409 }
5410 }
5412 /* Synthesize any needed methods. */
5414 cant_have_const_ctor,
5415 no_const_asn_ref);
5417 /* Check defaulted declarations here so we have cant_have_const_ctor
5418 and don't need to worry about clones. */
5421 {
5424 {
5425 bool imp_const_p
5431 /* If the function is defaulted outside the class, we just
5432 give the synthesis error. */
5435 }
5437 }
5440 {
5441 /* "The closure type associated with a lambda-expression has a deleted
5442 default constructor and a deleted copy assignment operator." */
5448 /* "This class type is not an aggregate." */
5450 }
5452 /* Compute the 'literal type' property before we
5453 do anything with non-static member functions. */
5456 /* Create the in-charge and not-in-charge variants of constructors
5457 and destructors. */
5460 /* Process the using-declarations. */
5464 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5467 /* Figure out whether or not we will need a cookie when dynamically
5468 allocating an array of this type. */
5471 }
5473 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5474 accordingly. If a new vfield was created (because T doesn't have a
5475 primary base class), then the newly created field is returned. It
5476 is not added to the TYPE_FIELDS list; it is the caller's
5477 responsibility to do that. Accumulate declared virtual functions
5478 on VIRTUALS_P. */
5480 static tree
5482 {
5483 tree fn;
5485 /* Collect the virtual functions declared in T. */
5489 {
5498 }
5500 /* If we couldn't find an appropriate base class, create a new field
5501 here. Even if there weren't any new virtual functions, we might need a
5502 new virtual function table if we're supposed to include vptrs in
5503 all classes that need them. */
5505 {
5506 /* We build this decl with vtbl_ptr_type_node, which is a
5507 `vtable_entry_type*'. It might seem more precise to use
5508 `vtable_entry_type (*)[N]' where N is the number of virtual
5509 functions. However, that would require the vtable pointer in
5510 base classes to have a different type than the vtable pointer
5511 in derived classes. We could make that happen, but that
5512 still wouldn't solve all the problems. In particular, the
5513 type-based alias analysis code would decide that assignments
5514 to the base class vtable pointer can't alias assignments to
5515 the derived class vtable pointer, since they have different
5516 types. Thus, in a derived class destructor, where the base
5517 class constructor was inlined, we could generate bad code for
5518 setting up the vtable pointer.
5520 Therefore, we use one type for all vtable pointers. We still
5521 use a type-correct type; it's just doesn't indicate the array
5522 bounds. That's better than using `void*' or some such; it's
5523 cleaner, and it let's the alias analysis code know that these
5524 stores cannot alias stores to void*! */
5525 tree field;
5538 /* This class is non-empty. */
5542 }
5545 }
5547 /* Add OFFSET to all base types of BINFO which is a base in the
5548 hierarchy dominated by T.
5550 OFFSET, which is a type offset, is number of bytes. */
5552 static void
5554 {
5556 tree primary_binfo;
5557 tree base_binfo;
5559 /* Update BINFO's offset. */
5564 offset));
5566 /* Find the primary base class. */
5572 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5573 downwards. */
5575 {
5576 /* Don't do the primary base twice. */
5584 }
5585 }
5587 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5588 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5589 empty subobjects of T. */
5591 static void
5593 {
5594 tree vbase;
5603 {
5604 /* In G++ 3.2, we incorrectly rounded the size before laying out
5605 the virtual bases. */
5607 #ifdef STRUCTURE_SIZE_BOUNDARY
5608 /* Packed structures don't need to have minimum size. */
5611 #endif
5615 }
5617 /* Find the last field. The artificial fields created for virtual
5618 bases will go after the last extant field to date. */
5623 /* Go through the virtual bases, allocating space for each virtual
5624 base that is not already a primary base class. These are
5625 allocated in inheritance graph order. */
5627 {
5632 {
5635 /* This virtual base is not a primary base of any class in the
5636 hierarchy, so we have to add space for it. */
5640 /* If the first virtual base might have been placed at a
5641 lower address, had we started from CLASSTYPE_SIZE, rather
5642 than TYPE_SIZE, issue a warning. There can be both false
5643 positives and false negatives from this warning in rare
5644 cases; to deal with all the possibilities would probably
5645 require performing both layout algorithms and comparing
5646 the results which is not particularly tractable. */
5648 && first_vbase
5649 && (tree_int_cst_lt
5654 bitsize_unit_node),
5657 "offset of virtual base %qT is not ABI-compliant and "
5659 basetype);
5662 }
5663 }
5664 }
5666 /* Returns the offset of the byte just past the end of the base class
5667 BINFO. */
5669 static tree
5671 {
5672 tree size;
5677 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5678 allocate some space for it. It cannot have virtual bases, so
5679 TYPE_SIZE_UNIT is fine. */
5681 else
5685 }
5687 /* Returns the offset of the byte just past the end of the base class
5688 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5689 only non-virtual bases are included. */
5691 static tree
5693 {
5696 tree binfo;
5697 tree base_binfo;
5698 tree offset;
5703 {
5713 }
5715 /* G++ 3.2 did not check indirect virtual bases. */
5719 {
5723 }
5726 }
5728 /* Warn about bases of T that are inaccessible because they are
5729 ambiguous. For example:
5731 struct S {};
5732 struct T : public S {};
5733 struct U : public S, public T {};
5735 Here, `(S*) new U' is not allowed because there are two `S'
5736 subobjects of U. */
5738 static void
5740 {
5743 tree basetype;
5744 tree binfo;
5745 tree base_binfo;
5747 /* If there are no repeated bases, nothing can be ambiguous. */
5751 /* Check direct bases. */
5754 {
5760 }
5762 /* Check for ambiguous virtual bases. */
5766 {
5772 }
5773 }
5775 /* Compare two INTEGER_CSTs K1 and K2. */
5777 static int
5779 {
5781 }
5783 /* Increase the size indicated in RLI to account for empty classes
5784 that are "off the end" of the class. */
5786 static void
5788 {
5789 tree eoc;
5790 tree rli_size;
5792 /* It might be the case that we grew the class to allocate a
5793 zero-sized base class. That won't be reflected in RLI, yet,
5794 because we are willing to overlay multiple bases at the same
5795 offset. However, now we need to make sure that RLI is big enough
5796 to reflect the entire class. */
5802 {
5804 /* In version 1 of the ABI, the size of a class that ends with
5805 a bitfield was not rounded up to a whole multiple of a
5806 byte. Because rli_size_unit_so_far returns only the number
5807 of fully allocated bytes, any extra bits were not included
5808 in the size. */
5810 else
5811 /* The size should have been rounded to a whole byte. */
5814 rli->bitpos
5823 }
5824 }
5826 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5827 BINFO_OFFSETs for all of the base-classes. Position the vtable
5828 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5830 static void
5832 {
5833 tree non_static_data_members;
5834 tree field;
5835 tree vptr;
5836 record_layout_info rli;
5837 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5838 types that appear at that offset. */
5839 splay_tree empty_base_offsets;
5840 /* True if the last field layed out was a bit-field. */
5842 /* The location at which the next field should be inserted. */
5844 /* T, as a base class. */
5845 tree base_t;
5847 /* Keep track of the first non-static data member. */
5850 /* Start laying out the record. */
5853 /* Mark all the primary bases in the hierarchy. */
5856 /* Create a pointer to our virtual function table. */
5859 /* The vptr is always the first thing in the class. */
5861 {
5866 }
5867 else
5870 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5875 /* Layout the non-static data members. */
5877 {
5878 tree type;
5879 tree padding;
5881 /* We still pass things that aren't non-static data members to
5882 the back end, in case it wants to do something with them. */
5884 {
5886 /* If the static data member has incomplete type, keep track
5887 of it so that it can be completed later. (The handling
5888 of pending statics in finish_record_layout is
5889 insufficient; consider:
5891 struct S1;
5892 struct S2 { static S1 s1; };
5894 At this point, finish_record_layout will be called, but
5895 S1 is still incomplete.) */
5897 {
5899 /* The visibility of static data members is determined
5900 at their point of declaration, not their point of
5901 definition. */
5903 }
5905 }
5913 /* If this field is a bit-field whose width is greater than its
5914 type, then there are some special rules for allocating
5915 it. */
5918 {
5920 tree integer_type;
5922 /* We must allocate the bits as if suitably aligned for the
5923 longest integer type that fits in this many bits. type
5924 of the field. Then, we are supposed to use the left over
5925 bits as additional padding. */
5934 /* ITK now indicates a type that is too large for the
5935 field. We have to back up by one to find the largest
5936 type that fits. */
5937 do
5938 {
5943 /* Figure out how much additional padding is required. GCC
5944 3.2 always created a padding field, even if it had zero
5945 width. */
5948 {
5950 /* In a union, the padding field must have the full width
5951 of the bit-field; all fields start at offset zero. */
5953 else
5954 {
5957 "ABI-compliant and may change in a future "
5959 t);
5962 }
5963 }
5964 #ifdef PCC_BITFIELD_TYPE_MATTERS
5965 /* An unnamed bitfield does not normally affect the
5966 alignment of the containing class on a target where
5967 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5968 make any exceptions for unnamed bitfields when the
5969 bitfields are longer than their types. Therefore, we
5970 temporarily give the field a name. */
5972 {
5975 }
5976 #endif
5981 empty_base_offsets);
5984 /* Now that layout has been performed, set the size of the
5985 field to the size of its declared type; the rest of the
5986 field is effectively invisible. */
5988 /* We must also reset the DECL_MODE of the field. */
5993 /* Versions of G++ before G++ 3.4 did not reset the
5994 DECL_MODE. */
5996 "the offset of %qD may not be ABI-compliant and may "
5998 }
5999 else
6001 empty_base_offsets);
6003 /* Remember the location of any empty classes in FIELD. */
6007 empty_base_offsets,
6010 /* If a bit-field does not immediately follow another bit-field,
6011 and yet it starts in the middle of a byte, we have failed to
6012 comply with the ABI. */
6015 /* The TREE_NO_WARNING flag gets set by Objective-C when
6016 laying out an Objective-C class. The ObjC ABI differs
6017 from the C++ ABI, and so we do not want a warning
6018 here. */
6020 && !last_field_was_bitfield
6023 bitsize_unit_node)))
6027 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6028 offset of the field. */
6035 "classes to be placed at different locations in a "
6038 /* The middle end uses the type of expressions to determine the
6039 possible range of expression values. In order to optimize
6040 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6041 must be made aware of the width of "i", via its type.
6043 Because C++ does not have integer types of arbitrary width,
6044 we must (for the purposes of the front end) convert from the
6045 type assigned here to the declared type of the bitfield
6046 whenever a bitfield expression is used as an rvalue.
6047 Similarly, when assigning a value to a bitfield, the value
6048 must be converted to the type given the bitfield here. */
6050 {
6055 {
6062 }
6063 }
6065 /* If we needed additional padding after this field, add it
6066 now. */
6068 {
6069 tree padding_field;
6072 FIELD_DECL,
6073 NULL_TREE,
6074 char_type_node);
6081 NULL_TREE,
6082 empty_base_offsets);
6083 }
6086 }
6089 {
6090 /* Make sure that we are on a byte boundary so that the size of
6091 the class without virtual bases will always be a round number
6092 of bytes. */
6095 }
6097 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6098 padding. */
6102 /* Delete all zero-width bit-fields from the list of fields. Now
6103 that the type is laid out they are no longer important. */
6106 /* Create the version of T used for virtual bases. We do not use
6107 make_class_type for this version; this is an artificial type. For
6108 a POD type, we just reuse T. */
6110 {
6113 /* Set the size and alignment for the new type. In G++ 3.2, all
6114 empty classes were considered to have size zero when used as
6115 base classes. */
6117 {
6122 "layout of classes derived from empty class %qT "
6124 t);
6125 }
6126 else
6127 {
6128 tree eoc;
6130 /* If the ABI version is not at least two, and the last
6131 field was a bit-field, RLI may not be on a byte
6132 boundary. In particular, rli_size_unit_so_far might
6133 indicate the last complete byte, while rli_size_so_far
6134 indicates the total number of bits used. Therefore,
6135 rli_size_so_far, rather than rli_size_unit_so_far, is
6136 used to compute TYPE_SIZE_UNIT. */
6144 eoc);
6151 }
6155 /* Copy the fields from T. */
6159 {
6161 FIELD_DECL,
6171 }
6173 /* Record the base version of the type. */
6176 }
6177 else
6180 /* Every empty class contains an empty class. */
6184 /* Set the TYPE_DECL for this type to contain the right
6185 value for DECL_OFFSET, so that we can use it as part
6186 of a COMPONENT_REF for multiple inheritance. */
6189 /* Now fix up any virtual base class types that we left lying
6190 around. We must get these done before we try to lay out the
6191 virtual function table. As a side-effect, this will remove the
6192 base subobject fields. */
6195 /* Make sure that empty classes are reflected in RLI at this
6196 point. */
6199 /* Make sure not to create any structures with zero size. */
6205 /* If this is a non-POD, declaring it packed makes a difference to how it
6206 can be used as a field; don't let finalize_record_size undo it. */
6210 /* Let the back end lay out the type. */
6213 /* Warn about bases that can't be talked about due to ambiguity. */
6216 /* Now that we're done with layout, give the base fields the real types. */
6221 /* Clean up. */
6228 }
6230 /* Determine the "key method" for the class type indicated by TYPE,
6231 and set CLASSTYPE_KEY_METHOD accordingly. */
6233 void
6235 {
6236 tree method;
6239 || processing_template_decl
6244 /* The key method is the first non-pure virtual function that is not
6245 inline at the point of class definition. On some targets the
6246 key function may not be inline; those targets should not call
6247 this function until the end of the translation unit. */
6253 {
6256 }
6259 }
6262 /* Allocate and return an instance of struct sorted_fields_type with
6263 N fields. */
6267 {
6274 }
6277 /* Perform processing required when the definition of T (a class type)
6278 is complete. */
6280 void
6282 {
6283 tree x;
6284 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6288 {
6293 }
6295 /* If this type was previously laid out as a forward reference,
6296 make sure we lay it out again. */
6300 /* Make assumptions about the class; we'll reset the flags if
6301 necessary. */
6307 /* Do end-of-class semantic processing: checking the validity of the
6308 bases and members and add implicitly generated methods. */
6311 /* Find the key method. */
6313 {
6314 /* The Itanium C++ ABI permits the key method to be chosen when
6315 the class is defined -- even though the key method so
6316 selected may later turn out to be an inline function. On
6317 some systems (such as ARM Symbian OS) the key method cannot
6318 be determined until the end of the translation unit. On such
6319 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6320 will cause the class to be added to KEYED_CLASSES. Then, in
6321 finish_file we will determine the key method. */
6325 /* If a polymorphic class has no key method, we may emit the vtable
6326 in every translation unit where the class definition appears. */
6329 }
6331 /* Layout the class itself. */
6334 /* We use the base type for trivial assignments, and hence it
6335 needs a mode. */
6340 /* If necessary, create the primary vtable for this class. */
6342 {
6343 /* We must enter these virtuals into the table. */
6347 /* Here we know enough to change the type of our virtual
6348 function table, but we will wait until later this function. */
6351 /* If we're warning about ABI tags, check the types of the new
6352 virtual functions. */
6356 }
6359 {
6361 tree fn;
6368 /* Add entries for virtual functions introduced by this class. */
6372 /* Set DECL_VINDEX for all functions declared in this class. */
6374 fn;
6376 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6378 {
6382 /* A thunk. We should never be calling this entry directly
6383 from this vtable -- we'd use the entry for the non
6384 thunk base function. */
6388 }
6389 }
6394 /* Complete the rtl for any static member objects of the type we're
6395 working on. */
6402 /* Done with FIELDS...now decide whether to sort these for
6403 faster lookups later.
6405 We use a small number because most searches fail (succeeding
6406 ultimately as the search bores through the inheritance
6407 hierarchy), and we want this failure to occur quickly. */
6411 /* Complain if one of the field types requires lower visibility. */
6414 /* Make the rtl for any new vtables we have created, and unmark
6415 the base types we marked. */
6418 /* Build the VTT for T. */
6421 /* This warning does not make sense for Java classes, since they
6422 cannot have destructors. */
6424 {
6425 tree dtor;
6429 if it were virtual, we would have created it by now. */
6430 !dtor
6439 "%q#T has virtual functions and accessible"
6441 }
6448 /* Class layout, assignment of virtual table slots, etc., is now
6449 complete. Give the back end a chance to tweak the visibility of
6450 the class or perform any other required target modifications. */
6457 /* Finish debugging output for this type. */
6461 {
6464 {
6467 }
6469 {
6472 else
6473 {
6476 }
6478 }
6480 {
6482 "the type of the first field has a different ABI from the "
6485 }
6486 }
6487 }
6489 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6490 equal to THRESHOLD or greater than THRESHOLD. */
6492 static void
6494 {
6497 {
6502 }
6503 }
6505 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6507 void
6509 {
6512 {
6514 int n_fields
6525 }
6526 }
6528 /* When T was built up, the member declarations were added in reverse
6529 order. Rearrange them to declaration order. */
6531 void
6533 {
6534 tree next;
6535 tree prev;
6536 tree x;
6538 /* The following lists are all in reverse order. Put them in
6539 declaration order now. */
6543 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6544 reverse order, so we can't just use nreverse. */
6549 {
6553 }
6555 {
6559 }
6560 }
6562 tree
6564 {
6567 /* Now that we've got all the field declarations, reverse everything
6568 as necessary. */
6573 /* Nadger the current location so that diagnostics point to the start of
6574 the struct, not the end. */
6578 {
6579 tree x;
6585 /* We need to emit an error message if this type was used as a parameter
6586 and it is an abstract type, even if it is a template. We construct
6587 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6588 account and we call complete_vars with this type, which will check
6589 the PARM_DECLS. Note that while the type is being defined,
6590 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6591 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6597 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6598 an enclosing scope is a template class, so that this function be
6599 found by lookup_fnfields_1 when the using declaration is not
6600 instantiated yet. */
6603 {
6608 }
6610 /* Remember current #pragma pack value. */
6613 /* Fix up any variants we've already built. */
6615 {
6620 }
6621 }
6622 else
6631 else
6635 /* Lambdas are defined by the LAMBDA_EXPR. */
6640 }
6641 \f
6642 /* Hash table to avoid endless recursion when handling references. */
6645 /* Return the dynamic type of INSTANCE, if known.
6646 Used to determine whether the virtual function table is needed
6647 or not.
6649 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6650 of our knowledge of its type. *NONNULL should be initialized
6651 before this function is called. */
6653 static tree
6655 {
6656 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6659 {
6663 else
6667 /* This is a call to a constructor, hence it's never zero. */
6669 {
6673 }
6677 /* This is a call to a constructor, hence it's never zero. */
6679 {
6683 }
6692 /* Propagate nonnull. */
6697 CASE_CONVERT:
6703 {
6704 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6705 with a real object -- given &p->f, p can still be null. */
6707 /* ??? Probably should check DECL_WEAK here. */
6710 }
6714 /* If this component is really a base class reference, then the field
6715 itself isn't definitive. */
6724 {
6728 }
6729 /* fall through... */
6734 {
6738 }
6740 {
6744 /* if we're in a ctor or dtor, we know our type. If
6745 current_class_ptr is set but we aren't in a function, we're in
6746 an NSDMI (and therefore a constructor). */
6751 {
6755 }
6756 }
6758 {
6759 /* We only need one hash table because it is always left empty. */
6763 /* Reference variables should be references to objects. */
6767 /* Enter the INSTANCE in a table to prevent recursion; a
6768 variable's initializer may refer to the variable
6769 itself. */
6774 {
6775 tree type;
6784 }
6785 }
6790 }
6791 #undef RECUR
6792 }
6794 /* Return nonzero if the dynamic type of INSTANCE is known, and
6795 equivalent to the static type. We also handle the case where
6796 INSTANCE is really a pointer. Return negative if this is a
6797 ctor/dtor. There the dynamic type is known, but this might not be
6798 the most derived base of the original object, and hence virtual
6799 bases may not be layed out according to this type.
6801 Used to determine whether the virtual function table is needed
6802 or not.
6804 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6805 of our knowledge of its type. *NONNULL should be initialized
6806 before this function is called. */
6808 int
6810 {
6813 tree fixed;
6815 /* processing_template_decl can be false in a template if we're in
6816 fold_non_dependent_expr, but we still want to suppress this check. */
6818 {
6819 /* In a template we only care about the type of the result. */
6823 }
6833 }
6835 \f
6836 void
6838 {
6841 current_class_stack
6849 }
6851 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6853 static void
6855 {
6856 tree type;
6858 /* We are re-entering the same class we just left, so we don't
6859 have to search the whole inheritance matrix to find all the
6860 decls to bind again. Instead, we install the cached
6861 class_shadowed list and walk through it binding names. */
6864 /* Restore IDENTIFIER_TYPE_VALUE. */
6866 type;
6869 }
6871 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6872 appropriate for TYPE.
6874 So that we may avoid calls to lookup_name, we cache the _TYPE
6875 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6877 For multiple inheritance, we perform a two-pass depth-first search
6878 of the type lattice. */
6880 void
6882 {
6883 class_stack_node_t csn;
6887 /* Make sure there is enough room for the new entry on the stack. */
6889 {
6891 current_class_stack
6893 current_class_stack_size);
6894 }
6896 /* Insert a new entry on the class stack. */
6903 current_class_depth++;
6905 /* Now set up the new type. */
6911 /* By default, things in classes are private, while things in
6912 structures or unions are public. */
6914 ? access_private_node
6920 {
6921 /* Forcibly remove any old class remnants. */
6923 }
6929 else
6931 }
6933 /* When we exit a toplevel class scope, we save its binding level so
6934 that we can restore it quickly. Here, we've entered some other
6935 class, so we must invalidate our cache. */
6937 void
6939 {
6941 }
6943 /* Get out of the current class scope. If we were in a class scope
6944 previously, that is the one popped to. */
6946 void
6948 {
6951 current_class_depth--;
6957 }
6959 /* Mark the top of the class stack as hidden. */
6961 void
6963 {
6966 }
6968 /* Mark the top of the class stack as un-hidden. */
6970 void
6972 {
6975 }
6977 /* Returns 1 if the class type currently being defined is either T or
6978 a nested type of T. */
6980 bool
6982 {
6990 /* We start looking from 1 because entry 0 is from global scope,
6991 and has no type. */
6993 {
6994 tree c;
6997 else
6998 {
7002 }
7007 }
7009 }
7011 /* If either current_class_type or one of its enclosing classes are derived
7012 from T, return the appropriate type. Used to determine how we found
7013 something via unqualified lookup. */
7015 tree
7017 {
7020 /* The bases of a dependent type are unknown. */
7031 {
7036 }
7039 }
7041 /* Returns the innermost class type which is not a lambda closure type. */
7043 tree
7045 {
7048 /* We start looking from 1 because entry 0 is from global scope,
7049 and has no type. */
7051 {
7052 tree c;
7055 else
7056 {
7060 }
7065 }
7067 }
7069 /* When entering a class scope, all enclosing class scopes' names with
7070 static meaning (static variables, static functions, types and
7071 enumerators) have to be visible. This recursive function calls
7072 pushclass for all enclosing class contexts until global or a local
7073 scope is reached. TYPE is the enclosed class. */
7075 void
7077 {
7078 /* A namespace might be passed in error cases, like A::B:C. */
7086 }
7088 /* Undoes a push_nested_class call. */
7090 void
7092 {
7098 }
7100 /* Returns the number of extern "LANG" blocks we are nested within. */
7102 int
7104 {
7106 }
7108 /* Set global variables CURRENT_LANG_NAME to appropriate value
7109 so that behavior of name-mangling machinery is correct. */
7111 void
7113 {
7117 {
7119 }
7121 {
7123 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7124 (See record_builtin_java_type in decl.c.) However, that causes
7125 incorrect debug entries if these types are actually used.
7126 So we re-enable debug output after extern "Java". */
7135 }
7137 {
7139 }
7140 else
7142 }
7144 /* Get out of the current language scope. */
7146 void
7148 {
7150 }
7151 \f
7152 /* Type instantiation routines. */
7154 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7155 matches the TARGET_TYPE. If there is no satisfactory match, return
7156 error_mark_node, and issue an error & warning messages under
7157 control of FLAGS. Permit pointers to member function if FLAGS
7158 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7159 a template-id, and EXPLICIT_TARGS are the explicitly provided
7160 template arguments.
7162 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7163 is the base path used to reference those member functions. If
7164 the address is resolved to a member function, access checks will be
7165 performed and errors issued if appropriate. */
7167 static tree
7169 tree overload,
7170 tsubst_flags_t flags,
7172 tree explicit_targs,
7173 tree access_path)
7174 {
7175 /* Here's what the standard says:
7177 [over.over]
7179 If the name is a function template, template argument deduction
7180 is done, and if the argument deduction succeeds, the deduced
7181 arguments are used to generate a single template function, which
7182 is added to the set of overloaded functions considered.
7184 Non-member functions and static member functions match targets of
7185 type "pointer-to-function" or "reference-to-function." Nonstatic
7186 member functions match targets of type "pointer-to-member
7187 function;" the function type of the pointer to member is used to
7188 select the member function from the set of overloaded member
7189 functions. If a nonstatic member function is selected, the
7190 reference to the overloaded function name is required to have the
7191 form of a pointer to member as described in 5.3.1.
7193 If more than one function is selected, any template functions in
7194 the set are eliminated if the set also contains a non-template
7195 function, and any given template function is eliminated if the
7196 set contains a second template function that is more specialized
7197 than the first according to the partial ordering rules 14.5.5.2.
7198 After such eliminations, if any, there shall remain exactly one
7199 selected function. */
7202 /* We store the matches in a TREE_LIST rooted here. The functions
7203 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7204 interoperability with most_specialized_instantiation. */
7206 tree fn;
7207 tree target_fn_type;
7209 /* By the time we get here, we should be seeing only real
7210 pointer-to-member types, not the internal POINTER_TYPE to
7211 METHOD_TYPE representation. */
7217 /* Check that the TARGET_TYPE is reasonable. */
7222 /* This is OK, too. */
7225 /* This is OK, too. This comes from a conversion to reference
7226 type. */
7228 else
7229 {
7235 }
7237 /* Non-member functions and static member functions match targets of type
7238 "pointer-to-function" or "reference-to-function." Nonstatic member
7239 functions match targets of type "pointer-to-member-function;" the
7240 function type of the pointer to member is used to select the member
7241 function from the set of overloaded member functions.
7243 So figure out the FUNCTION_TYPE that we want to match against. */
7246 /* If we can find a non-template function that matches, we can just
7247 use it. There's no point in generating template instantiations
7248 if we're just going to throw them out anyhow. But, of course, we
7249 can only do this when we don't *need* a template function. */
7251 {
7252 tree fns;
7255 {
7259 /* We're not looking for templates just yet. */
7264 /* We're looking for a non-static member, and this isn't
7265 one, or vice versa. */
7268 /* Ignore functions which haven't been explicitly
7269 declared. */
7273 /* See if there's a match. */
7276 }
7277 }
7279 /* Now, if we've already got a match (or matches), there's no need
7280 to proceed to the template functions. But, if we don't have a
7281 match we need to look at them, too. */
7283 {
7284 tree target_arg_types;
7285 tree target_ret_type;
7286 tree fns;
7289 tree arg;
7303 {
7305 tree instantiation;
7306 tree targs;
7309 /* We're only looking for templates. */
7314 /* We're not looking for a non-static member, and this is
7315 one, or vice versa. */
7320 /* If the template has a deduced return type, don't expose it to
7321 template argument deduction. */
7325 /* Try to do argument deduction. */
7332 /* Instantiation failed. */
7335 /* And now force instantiation to do return type deduction. */
7337 {
7343 }
7345 /* See if there's a match. */
7350 }
7352 /* Now, remove all but the most specialized of the matches. */
7354 {
7359 NULL_TREE,
7360 NULL_TREE);
7361 }
7362 }
7364 /* Now we should have exactly one function in MATCHES. */
7366 {
7367 /* There were *no* matches. */
7369 {
7372 target_type);
7375 }
7377 }
7379 {
7380 /* There were too many matches. First check if they're all
7381 the same function. */
7386 /* For multi-versioned functions, more than one match is just fine and
7387 decls_match will return false as they are different. */
7395 {
7397 {
7400 target_type);
7402 /* Since print_candidates expects the functions in the
7403 TREE_VALUE slot, we flip them here. */
7408 }
7411 }
7412 }
7414 /* Good, exactly one match. Now, convert it to the correct type. */
7419 {
7427 {
7430 }
7431 }
7433 /* If a pointer to a function that is multi-versioned is requested, the
7434 pointer to the dispatcher function is returned instead. This works
7435 well because indirectly calling the function will dispatch the right
7436 function version at run-time. */
7438 {
7442 /* Mark all the versions corresponding to the dispatcher as used. */
7445 }
7447 /* If we're doing overload resolution purely for the purpose of
7448 determining conversion sequences, we should not consider the
7449 function used. If this conversion sequence is selected, the
7450 function will be marked as used at this point. */
7452 {
7453 /* Make =delete work with SFINAE. */
7458 }
7460 /* We could not check access to member functions when this
7461 expression was originally created since we did not know at that
7462 time to which function the expression referred. */
7464 {
7467 }
7471 else
7472 {
7473 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7474 will mark the function as addressed, but here we must do it
7475 explicitly. */
7479 }
7480 }
7482 /* This function will instantiate the type of the expression given in
7483 RHS to match the type of LHSTYPE. If errors exist, then return
7484 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7485 we complain on errors. If we are not complaining, never modify rhs,
7486 as overload resolution wants to try many possible instantiations, in
7487 the hope that at least one will work.
7489 For non-recursive calls, LHSTYPE should be a function, pointer to
7490 function, or a pointer to member function. */
7492 tree
7494 {
7501 {
7505 }
7508 {
7515 /* Microsoft allows `A::f' to be resolved to a
7516 pointer-to-member. */
7517 ;
7518 else
7519 {
7524 }
7525 }
7528 {
7531 }
7533 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7534 deduce any type information. */
7536 {
7540 }
7542 /* There only a few kinds of expressions that may have a type
7543 dependent on overload resolution. */
7549 /* This should really only be used when attempting to distinguish
7550 what sort of a pointer to function we have. For now, any
7551 arithmetic operation which is not supported on pointers
7552 is rejected as an error. */
7555 {
7557 {
7563 /* Do not lose object's side effects. */
7567 }
7574 /* This can happen if we are forming a pointer-to-member for a
7575 member template. */
7578 /* Fall through. */
7581 {
7585 return
7589 }
7593 return
7597 access_path);
7600 {
7605 }
7612 }
7614 }
7615 \f
7616 /* Return the name of the virtual function pointer field
7617 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7618 this may have to look back through base types to find the
7619 ultimate field name. (For single inheritance, these could
7620 all be the same name. Who knows for multiple inheritance). */
7622 static tree
7624 {
7631 {
7637 }
7645 }
7647 void
7649 {
7656 {
7661 }
7662 }
7664 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7665 according to [class]:
7666 The class-name is also inserted
7667 into the scope of the class itself. For purposes of access checking,
7668 the inserted class name is treated as if it were a public member name. */
7670 void
7672 {
7675 tree saved_cas;
7690 }
7692 /* Returns 1 if TYPE contains only padding bytes. */
7694 int
7696 {
7703 /* In G++ 3.2, whether or not a class was empty was determined by
7704 looking at its size. */
7707 else
7709 }
7711 /* Returns true if TYPE contains an empty class. */
7713 static bool
7715 {
7719 {
7720 tree field;
7721 tree binfo;
7722 tree base_binfo;
7734 }
7738 }
7740 /* Returns true if TYPE contains no actual data, just various
7741 possible combinations of empty classes and possibly a vptr. */
7743 bool
7745 {
7747 {
7748 tree field;
7749 tree binfo;
7750 tree base_binfo;
7753 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7754 out, but we'd like to be able to check this before then. */
7768 }
7772 }
7774 /* Note that NAME was looked up while the current class was being
7775 defined and that the result of that lookup was DECL. */
7777 void
7779 {
7780 splay_tree names_used;
7782 /* If we're not defining a class, there's nothing to do. */
7788 /* If there's already a binding for this NAME, then we don't have
7789 anything to worry about. */
7802 }
7804 /* Note that NAME was declared (as DECL) in the current class. Check
7805 to see that the declaration is valid. */
7807 void
7809 {
7810 splay_tree names_used;
7811 splay_tree_node n;
7813 /* Look to see if we ever used this name. */
7814 names_used
7818 /* The C language allows members to be declared with a type of the same
7819 name, and the C++ standard says this diagnostic is not required. So
7820 allow it in extern "C" blocks unless predantic is specified.
7821 Allow it in all cases if -ms-extensions is specified. */
7827 {
7828 /* [basic.scope.class]
7830 A name N used in a class S shall refer to the same declaration
7831 in its context and when re-evaluated in the completed scope of
7832 S. */
7836 }
7837 }
7839 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7840 Secondary vtables are merged with primary vtables; this function
7841 will return the VAR_DECL for the primary vtable. */
7843 tree
7845 {
7846 tree decl;
7850 {
7853 }
7857 }
7860 /* Returns the binfo for the primary base of BINFO. If the resulting
7861 BINFO is a virtual base, and it is inherited elsewhere in the
7862 hierarchy, then the returned binfo might not be the primary base of
7863 BINFO in the complete object. Check BINFO_PRIMARY_P or
7864 BINFO_LOST_PRIMARY_P to be sure. */
7866 static tree
7868 {
7869 tree primary_base;
7876 }
7878 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7880 static int
7882 {
7886 }
7888 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7889 INDENT should be zero when called from the top level; it is
7890 incremented recursively. IGO indicates the next expected BINFO in
7891 inheritance graph ordering. */
7893 static tree
7896 tree binfo,
7897 tree igo,
7899 {
7901 tree base_binfo;
7909 {
7912 }
7927 {
7931 TFF_PLAIN_IDENTIFIER),
7933 }
7935 {
7938 }
7943 {
7947 {
7951 TFF_PLAIN_IDENTIFIER));
7952 }
7954 {
7958 TFF_PLAIN_IDENTIFIER));
7959 }
7961 {
7965 TFF_PLAIN_IDENTIFIER));
7966 }
7968 {
7972 TFF_PLAIN_IDENTIFIER));
7973 }
7977 }
7983 }
7985 /* Dump the BINFO hierarchy for T. */
7987 static void
7989 {
8001 }
8003 /* Debug interface to hierarchy dumping. */
8005 void
8007 {
8009 }
8011 static void
8013 {
8018 {
8021 }
8022 }
8024 static void
8026 {
8027 tree value;
8029 HOST_WIDE_INT elt;
8037 TFF_PLAIN_IDENTIFIER));
8044 }
8046 static void
8048 {
8056 {
8063 {
8068 }
8072 }
8075 }
8077 static void
8079 {
8087 {
8092 }
8095 }
8097 /* Dump a function or thunk and its thunkees. */
8099 static void
8101 {
8104 tree thunks;
8112 {
8122 else
8128 }
8132 }
8134 /* Dump the thunks for FN. */
8136 void
8138 {
8140 }
8142 /* Virtual function table initialization. */
8144 /* Create all the necessary vtables for T and its base classes. */
8146 static void
8148 {
8149 tree vbase;
8153 /* We lay out the primary and secondary vtables in one contiguous
8154 vtable. The primary vtable is first, followed by the non-virtual
8155 secondary vtables in inheritance graph order. */
8159 /* Then come the virtual bases, also in inheritance graph order. */
8161 {
8165 }
8169 }
8171 /* Initialize the vtable for BINFO with the INITS. */
8173 static void
8175 {
8176 tree decl;
8182 }
8184 /* Build the VTT (virtual table table) for T.
8185 A class requires a VTT if it has virtual bases.
8187 This holds
8188 1 - primary virtual pointer for complete object T
8189 2 - secondary VTTs for each direct non-virtual base of T which requires a
8190 VTT
8191 3 - secondary virtual pointers for each direct or indirect base of T which
8192 has virtual bases or is reachable via a virtual path from T.
8193 4 - secondary VTTs for each direct or indirect virtual base of T.
8195 Secondary VTTs look like complete object VTTs without part 4. */
8197 static void
8199 {
8200 tree type;
8201 tree vtt;
8202 tree index;
8205 /* Build up the initializers for the VTT. */
8210 /* If we didn't need a VTT, we're done. */
8214 /* Figure out the type of the VTT. */
8218 /* Now, build the VTT object itself. */
8221 /* Add the VTT to the vtables list. */
8226 }
8228 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8229 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8230 and CHAIN the vtable pointer for this binfo after construction is
8231 complete. VALUE can also be another BINFO, in which case we recurse. */
8233 static tree
8235 {
8236 tree vt;
8239 {
8245 else
8247 }
8250 }
8252 /* Data for secondary VTT initialization. */
8254 {
8255 /* Is this the primary VTT? */
8258 /* Current index into the VTT. */
8259 tree index;
8261 /* Vector of initializers built up. */
8264 /* The type being constructed by this secondary VTT. */
8265 tree type_being_constructed;
8268 /* Recursively build the VTT-initializer for BINFO (which is in the
8269 hierarchy dominated by T). INITS points to the end of the initializer
8270 list to date. INDEX is the VTT index where the next element will be
8271 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8272 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8273 for virtual bases of T. When it is not so, we build the constructor
8274 vtables for the BINFO-in-T variant. */
8276 static void
8279 {
8281 tree b;
8282 tree init;
8283 secondary_vptr_vtt_init_data data;
8286 /* We only need VTTs for subobjects with virtual bases. */
8290 /* We need to use a construction vtable if this is not the primary
8291 VTT. */
8293 {
8296 /* Record the offset in the VTT where this sub-VTT can be found. */
8298 }
8300 /* Add the address of the primary vtable for the complete object. */
8304 {
8307 }
8310 /* Recursively add the secondary VTTs for non-virtual bases. */
8315 /* Add secondary virtual pointers for all subobjects of BINFO with
8316 either virtual bases or reachable along a virtual path, except
8317 subobjects that are non-virtual primary bases. */
8327 /* data.inits might have grown as we added secondary virtual pointers.
8328 Make sure our caller knows about the new vector. */
8332 /* Add the secondary VTTs for virtual bases in inheritance graph
8333 order. */
8335 {
8340 }
8341 else
8342 /* Remove the ctor vtables we created. */
8344 }
8346 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8347 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8349 static tree
8351 {
8354 /* We don't care about bases that don't have vtables. */
8358 /* We're only interested in proper subobjects of the type being
8359 constructed. */
8363 /* We're only interested in bases with virtual bases or reachable
8364 via a virtual path from the type being constructed. */
8369 /* We're not interested in non-virtual primary bases. */
8373 /* Record the index where this secondary vptr can be found. */
8375 {
8380 {
8381 /* It's a primary virtual base, and this is not a
8382 construction vtable. Find the base this is primary of in
8383 the inheritance graph, and use that base's vtable
8384 now. */
8387 }
8388 }
8390 /* Add the initializer for the secondary vptr itself. */
8393 /* Advance the vtt index. */
8398 }
8400 /* Called from build_vtt_inits via dfs_walk. After building
8401 constructor vtables and generating the sub-vtt from them, we need
8402 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8403 binfo of the base whose sub vtt was generated. */
8405 static tree
8407 {
8411 /* If this class has no vtable, none of its bases do. */
8415 /* This might be a primary base, so have no vtable in this
8416 hierarchy. */
8419 /* If we scribbled the construction vtable vptr into BINFO, clear it
8420 out now. */
8426 }
8428 /* Build the construction vtable group for BINFO which is in the
8429 hierarchy dominated by T. */
8431 static void
8433 {
8434 tree type;
8435 tree vtbl;
8436 tree id;
8437 tree vbase;
8440 /* See if we've already created this construction vtable group. */
8446 /* Build a version of VTBL (with the wrong type) for use in
8447 constructing the addresses of secondary vtables in the
8448 construction vtable group. */
8451 /* Don't export construction vtables from shared libraries. Even on
8452 targets that don't support hidden visibility, this tells
8453 can_refer_decl_in_current_unit_p not to assume that it's safe to
8454 access from a different compilation unit (bz 54314). */
8462 /* Add the vtables for each of our virtual bases using the vbase in T
8463 binfo. */
8465 vbase;
8467 {
8468 tree b;
8475 }
8477 /* Figure out the type of the construction vtable. */
8484 /* Initialize the construction vtable. */
8488 }
8490 /* Add the vtbl initializers for BINFO (and its bases other than
8491 non-virtual primaries) to the list of INITS. BINFO is in the
8492 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8493 the constructor the vtbl inits should be accumulated for. (If this
8494 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8495 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8496 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8497 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8498 but are not necessarily the same in terms of layout. */
8500 static void
8502 tree orig_binfo,
8503 tree rtti_binfo,
8504 tree vtbl,
8505 tree t,
8507 {
8509 tree base_binfo;
8514 /* If it doesn't have a vptr, we don't do anything. */
8518 /* If we're building a construction vtable, we're not interested in
8519 subobjects that don't require construction vtables. */
8525 /* Build the initializers for the BINFO-in-T vtable. */
8528 /* Walk the BINFO and its bases. We walk in preorder so that as we
8529 initialize each vtable we can figure out at what offset the
8530 secondary vtable lies from the primary vtable. We can't use
8531 dfs_walk here because we need to iterate through bases of BINFO
8532 and RTTI_BINFO simultaneously. */
8534 {
8535 /* Skip virtual bases. */
8541 inits);
8542 }
8543 }
8545 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8546 BINFO vtable to L. */
8548 static void
8550 tree orig_binfo,
8551 tree rtti_binfo,
8552 tree orig_vtbl,
8553 tree t,
8555 {
8562 {
8563 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8564 primary virtual base. If it is not the same primary in
8565 the hierarchy of T, we'll need to generate a ctor vtable
8566 for it, to place at its location in T. If it is the same
8567 primary, we still need a VTT entry for the vtable, but it
8568 should point to the ctor vtable for the base it is a
8569 primary for within the sub-hierarchy of RTTI_BINFO.
8571 There are three possible cases:
8573 1) We are in the same place.
8574 2) We are a primary base within a lost primary virtual base of
8575 RTTI_BINFO.
8576 3) We are primary to something not a base of RTTI_BINFO. */
8578 tree b;
8581 /* First, look through the bases we are primary to for RTTI_BINFO
8582 or a virtual base. */
8585 {
8590 }
8591 /* If we run out of primary links, keep looking down our
8592 inheritance chain; we might be an indirect primary. */
8596 found:
8598 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8599 base B and it is a base of RTTI_BINFO, this is case 2. In
8600 either case, we share our vtable with LAST, i.e. the
8601 derived-most base within B of which we are a primary. */
8604 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8605 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8606 binfo_ctor_vtable after everything's been set up. */
8609 /* Otherwise, this is case 3 and we get our own. */
8610 }
8617 {
8618 tree index;
8621 /* Add the initializer for this vtable. */
8625 /* Figure out the position to which the VPTR should point. */
8631 }
8634 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8635 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8636 straighten this out. */
8639 /* Throw away any unneeded intializers. */
8641 else
8642 /* For an ordinary vtable, set BINFO_VTABLE. */
8644 }
8648 /* Construct the initializer for BINFO's virtual function table. BINFO
8649 is part of the hierarchy dominated by T. If we're building a
8650 construction vtable, the ORIG_BINFO is the binfo we should use to
8651 find the actual function pointers to put in the vtable - but they
8652 can be overridden on the path to most-derived in the graph that
8653 ORIG_BINFO belongs. Otherwise,
8654 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8655 BINFO that should be indicated by the RTTI information in the
8656 vtable; it will be a base class of T, rather than T itself, if we
8657 are building a construction vtable.
8659 The value returned is a TREE_LIST suitable for wrapping in a
8660 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8661 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8662 number of non-function entries in the vtable.
8664 It might seem that this function should never be called with a
8665 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8666 base is always subsumed by a derived class vtable. However, when
8667 we are building construction vtables, we do build vtables for
8668 primary bases; we need these while the primary base is being
8669 constructed. */
8671 static void
8673 tree orig_binfo,
8674 tree t,
8675 tree rtti_binfo,
8678 {
8679 tree v;
8680 vtbl_init_data vid;
8682 tree vbinfo;
8686 /* Initialize VID. */
8694 /* The first vbase or vcall offset is at index -3 in the vtable. */
8697 /* Add entries to the vtable for RTTI. */
8700 /* Create an array for keeping track of the functions we've
8701 processed. When we see multiple functions with the same
8702 signature, we share the vcall offsets. */
8704 /* Add the vcall and vbase offset entries. */
8707 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8708 build_vbase_offset_vtbl_entries. */
8713 /* If the target requires padding between data entries, add that now. */
8715 {
8720 /* Move data entries into their new positions and add padding
8721 after the new positions. Iterate backwards so we don't
8722 overwrite entries that we would need to process later. */
8725 ix--)
8726 {
8734 {
8738 null_pointer_node);
8739 }
8740 }
8741 }
8746 /* The initializers for virtual functions were built up in reverse
8747 order. Straighten them out and add them to the running list in one
8748 step. */
8757 /* Go through all the ordinary virtual functions, building up
8758 initializers. */
8760 {
8761 tree delta;
8762 tree vcall_index;
8769 {
8773 {
8776 }
8778 }
8780 /* If the only definition of this function signature along our
8781 primary base chain is from a lost primary, this vtable slot will
8782 never be used, so just zero it out. This is important to avoid
8783 requiring extra thunks which cannot be generated with the function.
8785 We first check this in update_vtable_entry_for_fn, so we handle
8786 restored primary bases properly; we also need to do it here so we
8787 zero out unused slots in ctor vtables, rather than filling them
8788 with erroneous values (though harmless, apart from relocation
8789 costs). */
8794 {
8795 /* Pull the offset for `this', and the function to call, out of
8796 the list. */
8803 /* You can't call an abstract virtual function; it's abstract.
8804 So, we replace these functions with __pure_virtual. */
8806 {
8809 {
8811 abort_fndecl_addr
8815 }
8816 }
8817 /* Likewise for deleted virtuals. */
8819 {
8824 NULL_TREE);
8828 }
8829 else
8830 {
8832 {
8836 }
8837 /* Take the address of the function, considering it to be of an
8838 appropriate generic type. */
8842 }
8843 }
8845 /* And add it to the chain of initializers. */
8847 {
8852 else
8854 {
8860 }
8861 }
8862 else
8864 }
8865 }
8867 /* Adds to vid->inits the initializers for the vbase and vcall
8868 offsets in BINFO, which is in the hierarchy dominated by T. */
8870 static void
8872 {
8873 tree b;
8875 /* If this is a derived class, we must first create entries
8876 corresponding to the primary base class. */
8881 /* Add the vbase entries for this base. */
8883 /* Add the vcall entries for this base. */
8885 }
8887 /* Returns the initializers for the vbase offset entries in the vtable
8888 for BINFO (which is part of the class hierarchy dominated by T), in
8889 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8890 where the next vbase offset will go. */
8892 static void
8894 {
8895 tree vbase;
8896 tree t;
8897 tree non_primary_binfo;
8899 /* If there are no virtual baseclasses, then there is nothing to
8900 do. */
8906 /* We might be a primary base class. Go up the inheritance hierarchy
8907 until we find the most derived class of which we are a primary base:
8908 it is the offset of that which we need to use. */
8911 {
8912 tree b;
8914 /* If we have reached a virtual base, then it must be a primary
8915 base (possibly multi-level) of vid->binfo, or we wouldn't
8916 have called build_vcall_and_vbase_vtbl_entries for it. But it
8917 might be a lost primary, so just skip down to vid->binfo. */
8919 {
8922 }
8928 }
8930 /* Go through the virtual bases, adding the offsets. */
8932 vbase;
8934 {
8935 tree b;
8936 tree delta;
8941 /* Find the instance of this virtual base in the complete
8942 object. */
8945 /* If we've already got an offset for this virtual base, we
8946 don't need another one. */
8951 /* Figure out where we can find this vbase offset. */
8960 /* The vbase offset had better be the same. */
8963 /* The next vbase will come at a more negative offset. */
8967 /* The initializer is the delta from BINFO to this virtual base.
8968 The vbase offsets go in reverse inheritance-graph order, and
8969 we are walking in inheritance graph order so these end up in
8970 the right order. */
8977 }
8978 }
8980 /* Adds the initializers for the vcall offset entries in the vtable
8981 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8982 to VID->INITS. */
8984 static void
8986 {
8987 /* We only need these entries if this base is a virtual base. We
8988 compute the indices -- but do not add to the vtable -- when
8989 building the main vtable for a class. */
8992 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8993 correspond to VID->DERIVED), we are building a primary
8994 construction virtual table. Since this is a primary
8995 virtual table, we do not need the vcall offsets for
8996 BINFO. */
8998 {
8999 /* We need a vcall offset for each of the virtual functions in this
9000 vtable. For example:
9002 class A { virtual void f (); };
9003 class B1 : virtual public A { virtual void f (); };
9004 class B2 : virtual public A { virtual void f (); };
9005 class C: public B1, public B2 { virtual void f (); };
9007 A C object has a primary base of B1, which has a primary base of A. A
9008 C also has a secondary base of B2, which no longer has a primary base
9009 of A. So the B2-in-C construction vtable needs a secondary vtable for
9010 A, which will adjust the A* to a B2* to call f. We have no way of
9011 knowing what (or even whether) this offset will be when we define B2,
9012 so we store this "vcall offset" in the A sub-vtable and look it up in
9013 a "virtual thunk" for B2::f.
9015 We need entries for all the functions in our primary vtable and
9016 in our non-virtual bases' secondary vtables. */
9018 /* If we are just computing the vcall indices -- but do not need
9019 the actual entries -- not that. */
9022 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9024 }
9025 }
9027 /* Build vcall offsets, starting with those for BINFO. */
9029 static void
9031 {
9033 tree primary_binfo;
9034 tree base_binfo;
9036 /* Don't walk into virtual bases -- except, of course, for the
9037 virtual base for which we are building vcall offsets. Any
9038 primary virtual base will have already had its offsets generated
9039 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9043 /* If BINFO has a primary base, process it first. */
9048 /* Add BINFO itself to the list. */
9051 /* Scan the non-primary bases of BINFO. */
9055 }
9057 /* Called from build_vcall_offset_vtbl_entries_r. */
9059 static void
9061 {
9062 /* Make entries for the rest of the virtuals. */
9064 {
9065 tree orig_fn;
9067 /* The ABI requires that the methods be processed in declaration
9068 order. G++ 3.2 used the order in the vtable. */
9070 orig_fn;
9074 }
9075 else
9076 {
9077 tree derived_virtuals;
9078 tree base_virtuals;
9079 tree orig_virtuals;
9080 /* If BINFO is a primary base, the most derived class which has
9081 BINFO as a primary base; otherwise, just BINFO. */
9082 tree non_primary_binfo;
9084 /* We might be a primary base class. Go up the inheritance hierarchy
9085 until we find the most derived class of which we are a primary base:
9086 it is the BINFO_VIRTUALS there that we need to consider. */
9089 {
9090 tree b;
9092 /* If we have reached a virtual base, then it must be vid->vbase,
9093 because we ignore other virtual bases in
9094 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9095 base (possibly multi-level) of vid->binfo, or we wouldn't
9096 have called build_vcall_and_vbase_vtbl_entries for it. But it
9097 might be a lost primary, so just skip down to vid->binfo. */
9099 {
9103 }
9109 }
9112 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9113 where rtti_binfo is the most derived type. */
9114 non_primary_binfo
9120 base_virtuals;
9124 {
9125 tree orig_fn;
9127 /* Find the declaration that originally caused this function to
9128 be present in BINFO_TYPE (binfo). */
9131 /* When processing BINFO, we only want to generate vcall slots for
9132 function slots introduced in BINFO. So don't try to generate
9133 one if the function isn't even defined in BINFO. */
9138 }
9139 }
9140 }
9142 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9144 static void
9146 {
9148 tree vcall_offset;
9149 tree derived_entry;
9151 /* If there is already an entry for a function with the same
9152 signature as FN, then we do not need a second vcall offset.
9153 Check the list of functions already present in the derived
9154 class vtable. */
9156 {
9158 /* We only use one vcall offset for virtual destructors,
9159 even though there are two virtual table entries. */
9163 }
9165 /* If we are building these vcall offsets as part of building
9166 the vtable for the most derived class, remember the vcall
9167 offset. */
9169 {
9172 }
9174 /* The next vcall offset will be found at a more negative
9175 offset. */
9179 /* Keep track of this function. */
9183 {
9184 tree base;
9185 tree fn;
9187 /* Find the overriding function. */
9191 else
9192 {
9195 /* The vbase we're working on is a primary base of
9196 vid->binfo. But it might be a lost primary, so its
9197 BINFO_OFFSET might be wrong, so we just use the
9198 BINFO_OFFSET from vid->binfo. */
9204 vcall_offset);
9205 }
9206 /* Add the initializer to the vtable. */
9208 }
9209 }
9211 /* Return vtbl initializers for the RTTI entries corresponding to the
9212 BINFO's vtable. The RTTI entries should indicate the object given
9213 by VID->rtti_binfo. */
9215 static void
9217 {
9218 tree b;
9219 tree t;
9220 tree offset;
9221 tree decl;
9222 tree init;
9226 /* To find the complete object, we will first convert to our most
9227 primary base, and then add the offset in the vtbl to that value. */
9231 {
9232 tree primary_base;
9238 }
9242 /* The second entry is the address of the typeinfo object. */
9245 else
9248 /* Convert the declaration to a type that can be stored in the
9249 vtable. */
9253 /* Add the offset-to-top entry. It comes earlier in the vtable than
9254 the typeinfo entry. Convert the offset to look like a
9255 function pointer, so that we can put it in the vtable. */
9258 }
9260 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9261 accessibility. */
9263 bool
9265 {
9268 }
9270 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9272 bool
9274 {
9278 }
9280 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9281 class between them, if any. */
9283 tree
9285 {
9297 {
9300 }
9304 }