| blob | 31cd1c701080d6d85a27291f0fba1dfd55462c21 |
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 // Returns true if NEW_FN and OLD_FN are non-template member functions
938 // of a class template with with different constraints. The types of the
939 // functions are assumed to be equivalent.
942 {
943 // Non-temploids cannot be constrained.
947 else
949 }
951 \f
952 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
953 the USING_DECL naming METHOD. Returns true if the method could be
954 added to the method vec. */
956 bool
958 {
960 tree overload;
966 tree current_fns;
967 tree fns;
980 {
981 /* Make a new method vector. We start with 8 entries. We must
982 allocate at least two (for constructors and destructors), and
983 we're going to end up with an assignment operator at some
984 point as well. */
986 /* Create slots for constructors and destructors. */
990 }
992 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
995 /* Constructors and destructors go in special slots. */
999 {
1003 {
1009 type);
1010 }
1011 }
1012 else
1013 {
1014 tree m;
1017 /* See if we already have an entry with this name. */
1021 {
1024 {
1029 }
1033 {
1036 }
1041 }
1042 }
1045 /* Check to see if we've already got this method. */
1047 {
1049 tree fn_type;
1050 tree method_type;
1051 tree parms1;
1052 tree parms2;
1057 /* [over.load] Member function declarations with the
1058 same name and the same parameter types cannot be
1059 overloaded if any of them is a static member
1060 function declaration.
1062 [over.load] Member function declarations with the same name and
1063 the same parameter-type-list as well as member function template
1064 declarations with the same name, the same parameter-type-list, and
1065 the same template parameter lists cannot be overloaded if any of
1066 them, but not all, have a ref-qualifier.
1068 [namespace.udecl] When a using-declaration brings names
1069 from a base class into a derived class scope, member
1070 functions in the derived class override and/or hide member
1071 functions with the same name and parameter types in a base
1072 class (rather than conflicting). */
1078 /* Compare the quals on the 'this' parm. Don't compare
1079 the whole types, as used functions are treated as
1080 coming from the using class in overload resolution. */
1083 /* Either both or neither need to be ref-qualified for
1084 differing quals to allow overloading. */
1091 /* For templates, the return type and template parameters
1092 must be identical. */
1109 {
1110 /* For function versions, their parms and types match
1111 but they are not duplicates. Record function versions
1112 as and when they are found. extern "C" functions are
1113 not treated as versions. */
1119 {
1120 /* Mark functions as versions if necessary. Modify the mangled
1121 decl name if necessary. */
1123 {
1127 }
1129 {
1133 }
1136 }
1138 {
1140 {
1147 }
1148 /* Otherwise defer to the other function. */
1150 }
1152 {
1154 /* Defer to the local function. */
1156 }
1159 else
1160 {
1163 }
1165 /* We don't call duplicate_decls here to merge the
1166 declarations because that will confuse things if the
1167 methods have inline definitions. In particular, we
1168 will crash while processing the definitions. */
1170 }
1171 }
1173 /* A class should never have more than one destructor. */
1177 /* Add the new binding. */
1179 {
1182 }
1183 else
1192 {
1195 /* We only expect to add few methods in the COMPLETE_P case, so
1196 just make room for one more method in that case. */
1199 else
1205 else
1207 }
1208 else
1209 /* Replace the current slot. */
1212 }
1214 /* Subroutines of finish_struct. */
1216 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1217 legit, otherwise return 0. */
1219 static int
1221 {
1222 tree elem;
1231 {
1233 {
1237 else
1240 }
1241 else
1242 {
1243 /* They're changing the access to the same thing they changed
1244 it to before. That's OK. */
1245 ;
1246 }
1247 }
1248 else
1249 {
1251 tf_warning_or_error);
1254 }
1256 }
1258 /* Process the USING_DECL, which is a member of T. */
1260 static void
1262 {
1265 tree access
1270 tree old_value;
1275 tf_warning_or_error);
1277 {
1283 else
1285 }
1293 ;
1295 {
1297 /* It's OK to use functions from a base when there are functions with
1299 else
1300 {
1305 }
1306 }
1308 {
1312 }
1314 /* Make type T see field decl FDECL with access ACCESS. */
1317 {
1320 }
1321 else
1323 }
1324 \f
1325 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1326 types with abi tags, add the corresponding identifiers to the VEC in
1327 *DATA and set IDENTIFIER_MARKED. */
1329 struct abi_tag_data
1330 {
1331 tree t;
1332 tree subob;
1333 };
1335 static tree
1337 {
1342 {
1346 {
1350 {
1352 {
1357 }
1358 else
1359 {
1366 }
1367 }
1368 }
1369 }
1371 }
1373 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its (transitively
1374 complete) template arguments. */
1376 static void
1378 {
1381 {
1384 {
1388 }
1389 }
1391 /* Also mark ABI tags from template arguments. */
1393 {
1396 {
1399 {
1403 }
1404 }
1405 }
1406 }
1408 /* Check that class T has all the abi tags that subobject SUBOB has, or
1409 warn if not. */
1411 static void
1413 {
1422 }
1424 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1425 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1426 properties of the bases. */
1428 static void
1432 {
1436 tree base_binfo;
1437 tree binfo;
1447 {
1456 /* If any base class is non-literal, so is the derived class. */
1460 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1461 here because the case of virtual functions but non-virtual
1462 dtor is handled in finish_struct_1. */
1467 /* If the base class doesn't have copy constructors or
1468 assignment operators that take const references, then the
1469 derived class cannot have such a member automatically
1470 generated. */
1479 /* A virtual base does not effect nearly emptiness. */
1480 ;
1482 {
1484 /* And if there is more than one nearly empty base, then the
1485 derived class is not nearly empty either. */
1487 else
1488 /* Remember we've seen one. */
1490 }
1492 /* If the base class is not empty or nearly empty, then this
1493 class cannot be nearly empty. */
1496 /* A lot of properties from the bases also apply to the derived
1497 class. */
1515 /* A standard-layout class is a class that:
1516 ...
1517 * has no non-standard-layout base classes, */
1520 {
1521 tree basefield;
1522 /* ...has no base classes of the same type as the first non-static
1523 data member... */
1525 && (same_type_ignoring_top_level_qualifiers_p
1528 else
1529 /* ...either has no non-static data members in the most-derived
1530 class and at most one base class with non-static data
1531 members, or has no base classes with non-static data
1532 members */
1536 {
1539 else
1542 }
1543 }
1545 /* Don't bother collecting tm attributes if transactional memory
1546 support is not enabled. */
1548 {
1552 }
1555 }
1557 /* If one of the base classes had TM attributes, and the current class
1558 doesn't define its own, then the current class inherits one. */
1560 {
1563 }
1564 }
1566 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1567 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1568 that have had a nearly-empty virtual primary base stolen by some
1569 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1570 T. */
1572 static void
1574 {
1578 tree base_binfo;
1580 /* Determine the primary bases of our bases. */
1583 {
1586 /* See if we're the non-virtual primary of our inheritance
1587 chain. */
1589 {
1596 /* We are the primary binfo. */
1598 }
1599 /* Determine if we have a virtual primary base, and mark it so.
1600 */
1602 {
1606 /* Someone already claimed this base. */
1608 else
1609 {
1610 tree delta;
1615 /* A virtual binfo might have been copied from within
1616 another hierarchy. As we're about to use it as a
1617 primary base, make sure the offsets match. */
1625 }
1626 }
1627 }
1629 /* First look for a dynamic direct non-virtual base. */
1631 {
1635 {
1638 }
1639 }
1641 /* A "nearly-empty" virtual base class can be the primary base
1642 class, if no non-virtual polymorphic base can be found. Look for
1643 a nearly-empty virtual dynamic base that is not already a primary
1644 base of something in the hierarchy. If there is no such base,
1645 just pick the first nearly-empty virtual base. */
1651 {
1653 {
1654 /* Found one that is not primary. */
1657 }
1659 /* Remember the first candidate. */
1661 }
1663 found:
1664 /* If we've got a primary base, use it. */
1666 {
1671 /* We are stealing a primary base. */
1675 {
1676 tree delta;
1679 /* A virtual binfo might have been copied from within
1680 another hierarchy. As we're about to use it as a primary
1681 base, make sure the offsets match. */
1686 }
1693 }
1694 }
1696 /* Update the variant types of T. */
1698 void
1700 {
1701 tree variants;
1707 variants;
1709 {
1710 /* These fields are in the _TYPE part of the node, not in
1711 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1721 /* Copy whatever these are holding today. */
1725 }
1726 }
1728 /* Early variant fixups: we apply attributes at the beginning of the class
1729 definition, and we need to fix up any variants that have already been
1730 made via elaborated-type-specifier so that check_qualified_type works. */
1732 void
1734 {
1735 tree variants;
1741 variants;
1743 {
1744 /* These are the two fields that check_qualified_type looks at and
1745 are affected by attributes. */
1748 }
1749 }
1750 \f
1751 /* Set memoizing fields and bits of T (and its variants) for later
1752 use. */
1754 static void
1756 {
1757 /* Fix up variants (if any). */
1761 /* For a class w/o baseclasses, 'finish_struct' has set
1762 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1763 Similarly for a class whose base classes do not have vtables.
1764 When neither of these is true, we might have removed abstract
1765 virtuals (by providing a definition), added some (by declaring
1766 new ones), or redeclared ones from a base class. We need to
1767 recalculate what's really an abstract virtual at this point (by
1768 looking in the vtables). */
1771 /* If this type has a copy constructor or a destructor, force its
1772 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1773 nonzero. This will cause it to be passed by invisible reference
1774 and prevent it from being returned in a register. */
1777 {
1778 tree variants;
1781 {
1784 }
1785 }
1786 }
1788 /* Issue warnings about T having private constructors, but no friends,
1789 and so forth.
1791 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1792 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1793 non-private static member functions. */
1795 static void
1797 {
1800 tree fn;
1803 /* If the class has friends, those entities might create and
1804 access instances, so we should not warn. */
1807 /* We will have warned when the template was declared; there's
1808 no need to warn on every instantiation. */
1810 /* There's no reason to even consider warning about this
1811 class. */
1814 /* We only issue one warning, if more than one applies, because
1815 otherwise, on code like:
1817 class A {
1818 // Oops - forgot `public:'
1819 A();
1820 A(const A&);
1821 ~A();
1822 };
1824 we warn several times about essentially the same problem. */
1826 /* Check to see if all (non-constructor, non-destructor) member
1827 functions are private. (Since there are no friends or
1828 non-private statics, we can't ever call any of the private member
1829 functions.) */
1831 /* We're not interested in compiler-generated methods; they don't
1832 provide any way to call private members. */
1834 {
1836 {
1838 /* A non-private static member function is just like a
1839 friend; it can create and invoke private member
1840 functions, and be accessed without a class
1841 instance. */
1845 /* Keep searching for a static member function. */
1846 }
1849 }
1852 {
1853 /* There are no non-private methods, and there's at least one
1854 private member function that isn't a constructor or
1855 destructor. (If all the private members are
1856 constructors/destructors we want to use the code below that
1857 issues error messages specifically referring to
1858 constructors/destructors.) */
1864 {
1867 }
1869 {
1873 }
1874 }
1876 /* Even if some of the member functions are non-private, the class
1877 won't be useful for much if all the constructors or destructors
1878 are private: such an object can never be created or destroyed. */
1881 {
1884 t);
1886 }
1888 /* Warn about classes that have private constructors and no friends. */
1890 /* Implicitly generated constructors are always public. */
1893 {
1896 /* If a non-template class does not define a copy
1897 constructor, one is defined for it, enabling it to avoid
1898 this warning. For a template class, this does not
1899 happen, and so we would normally get a warning on:
1901 template <class T> class C { private: C(); };
1903 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1904 complete non-template or fully instantiated classes have this
1905 flag set. */
1908 else
1910 {
1912 /* Ideally, we wouldn't count copy constructors (or, in
1913 fact, any constructor that takes an argument of the
1914 class type as a parameter) because such things cannot
1915 be used to construct an instance of the class unless
1916 you already have one. But, for now at least, we're
1917 more generous. */
1919 {
1922 }
1923 }
1926 {
1929 t);
1931 }
1932 }
1933 }
1936 gt_pointer_operator new_value;
1940 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1942 static int
1944 {
1957 }
1959 /* This routine compares two fields like method_name_cmp but using the
1960 pointer operator in resort_field_decl_data. */
1962 static int
1964 {
1973 {
1980 }
1982 }
1984 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1986 void
1989 gt_pointer_operator new_value,
1991 {
1995 tree fn;
1997 /* The type conversion ops have to live at the front of the vec, so we
1998 can't sort them. */
2006 {
2010 resort_method_name_cmp);
2011 }
2012 }
2014 /* Warn about duplicate methods in fn_fields.
2016 Sort methods that are not special (i.e., constructors, destructors,
2017 and type conversion operators) so that we can find them faster in
2018 search. */
2020 static void
2022 {
2023 tree fn_fields;
2033 /* Clear DECL_IN_AGGR_P for all functions. */
2038 /* Issue warnings about private constructors and such. If there are
2039 no methods, then some public defaults are generated. */
2042 /* The type conversion ops have to live at the front of the vec, so we
2043 can't sort them. */
2052 }
2054 /* Make BINFO's vtable have N entries, including RTTI entries,
2055 vbase and vcall offsets, etc. Set its type and call the back end
2056 to lay it out. */
2058 static void
2060 {
2061 tree atype;
2062 tree vtable;
2067 /* We may have to grow the vtable. */
2070 {
2074 }
2075 }
2077 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2078 have the same signature. */
2080 int
2082 {
2083 /* One destructor overrides another if they are the same kind of
2084 destructor. */
2088 /* But a non-destructor never overrides a destructor, nor vice
2089 versa, nor do different kinds of destructors override
2090 one-another. For example, a complete object destructor does not
2091 override a deleting destructor. */
2100 {
2108 }
2110 }
2112 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2113 subobject. */
2115 static bool
2117 {
2118 tree probe;
2121 {
2125 /* If we meet a virtual base, we can't follow the inheritance
2126 any more. See if the complete type of DERIVED contains
2127 such a virtual base. */
2130 }
2132 }
2135 /* The function for which we are trying to find a final overrider. */
2136 tree fn;
2137 /* The base class in which the function was declared. */
2138 tree declaring_base;
2139 /* The candidate overriders. */
2140 tree candidates;
2141 /* Path to most derived. */
2145 /* Add the overrider along the current path to FFOD->CANDIDATES.
2146 Returns true if an overrider was found; false otherwise. */
2148 static bool
2152 {
2153 tree method;
2155 /* If BINFO is not the most derived type, try a more derived class.
2156 A definition there will overrider a definition here. */
2158 {
2159 depth--;
2163 }
2167 {
2170 /* Remove any candidates overridden by this new function. */
2172 {
2173 /* If *CANDIDATE overrides METHOD, then METHOD
2174 cannot override anything else on the list. */
2177 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2180 else
2182 }
2184 /* Add the new function. */
2187 }
2190 }
2192 /* Called from find_final_overrider via dfs_walk. */
2194 static tree
2196 {
2204 }
2206 static tree
2208 {
2213 }
2215 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2216 FN and whose TREE_VALUE is the binfo for the base where the
2217 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2218 DERIVED) is the base object in which FN is declared. */
2220 static tree
2222 {
2223 find_final_overrider_data ffod;
2225 /* Getting this right is a little tricky. This is valid:
2227 struct S { virtual void f (); };
2228 struct T { virtual void f (); };
2229 struct U : public S, public T { };
2231 even though calling `f' in `U' is ambiguous. But,
2233 struct R { virtual void f(); };
2234 struct S : virtual public R { virtual void f (); };
2235 struct T : virtual public R { virtual void f (); };
2236 struct U : public S, public T { };
2238 is not -- there's no way to decide whether to put `S::f' or
2239 `T::f' in the vtable for `R'.
2241 The solution is to look at all paths to BINFO. If we find
2242 different overriders along any two, then there is a problem. */
2246 /* Determine the depth of the hierarchy. */
2257 /* If there was no winner, issue an error message. */
2262 }
2264 /* Return the index of the vcall offset for FN when TYPE is used as a
2265 virtual base. */
2267 static tree
2269 {
2271 tree_pair_p p;
2279 /* There should always be an appropriate index. */
2281 }
2283 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2284 dominated by T. FN is the old function; VIRTUALS points to the
2285 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2286 of that entry in the list. */
2288 static void
2291 {
2292 tree b;
2293 tree overrider;
2294 tree delta;
2295 tree virtual_base;
2296 tree first_defn;
2302 /* Find the nearest primary base (possibly binfo itself) which defines
2303 this function; this is the class the caller will convert to when
2304 calling FN through BINFO. */
2306 {
2311 /* The nearest definition is from a lost primary. */
2314 }
2317 /* Find the final overrider. */
2320 {
2323 }
2326 /* Check for adjusting covariant return types. */
2334 /* If the overrider is invalid, don't even try. */
2336 {
2337 /* If FN is a covariant thunk, we must figure out the adjustment
2338 to the final base FN was converting to. As OVERRIDER_TARGET might
2339 also be converting to the return type of FN, we have to
2340 combine the two conversions here. */
2347 {
2351 }
2352 else
2356 /* Find the equivalent binfo within the return type of the
2357 overriding function. We will want the vbase offset from
2358 there. */
2360 over_return);
2363 {
2364 /* There was no existing virtual thunk (which takes
2365 precedence). So find the binfo of the base function's
2366 return type within the overriding function's return type.
2367 We cannot call lookup base here, because we're inside a
2368 dfs_walk, and will therefore clobber the BINFO_MARKED
2369 flags. Fortunately we know the covariancy is valid (it
2370 has already been checked), so we can just iterate along
2371 the binfos, which have been chained in inheritance graph
2372 order. Of course it is lame that we have to repeat the
2373 search here anyway -- we should really be caching pieces
2374 of the vtable and avoiding this repeated work. */
2377 /* Find the base binfo within the overriding function's
2378 return type. We will always find a thunk_binfo, except
2379 when the covariancy is invalid (which we will have
2380 already diagnosed). */
2383 thunk_binfo;
2389 /* See if virtual inheritance is involved. */
2391 virtual_offset;
2398 {
2402 {
2403 /* We convert via virtual base. Adjust the fixed
2404 offset to be from there. */
2405 offset =
2409 }
2411 /* There was an existing fixed offset, this must be
2412 from the base just converted to, and the base the
2413 FN was thunking to. */
2415 else
2417 }
2418 }
2421 /* Replace the overriding function with a covariant thunk. We
2422 will emit the overriding function in its own slot as
2423 well. */
2426 }
2427 else
2431 /* If we need a covariant thunk, then we may need to adjust first_defn.
2432 The ABI specifies that the thunks emitted with a function are
2433 determined by which bases the function overrides, so we need to be
2434 sure that we're using a thunk for some overridden base; even if we
2435 know that the necessary this adjustment is zero, there may not be an
2436 appropriate zero-this-adjusment thunk for us to use since thunks for
2437 overriding virtual bases always use the vcall offset.
2439 Furthermore, just choosing any base that overrides this function isn't
2440 quite right, as this slot won't be used for calls through a type that
2441 puts a covariant thunk here. Calling the function through such a type
2442 will use a different slot, and that slot is the one that determines
2443 the thunk emitted for that base.
2445 So, keep looking until we find the base that we're really overriding
2446 in this slot: the nearest primary base that doesn't use a covariant
2447 thunk in this slot. */
2449 {
2451 /* We already know that the overrider needs a covariant thunk. */
2454 {
2461 }
2463 }
2465 /* Assume that we will produce a thunk that convert all the way to
2466 the final overrider, and not to an intermediate virtual base. */
2469 /* See if we can convert to an intermediate virtual base first, and then
2470 use the vcall offset located there to finish the conversion. */
2472 {
2473 /* If we find the final overrider, then we can stop
2474 walking. */
2479 /* If we find a virtual base, and we haven't yet found the
2480 overrider, then there is a virtual base between the
2481 declaring base (first_defn) and the final overrider. */
2483 {
2486 }
2487 }
2489 /* Compute the constant adjustment to the `this' pointer. The
2490 `this' pointer, when this function is called, will point at BINFO
2491 (or one of its primary bases, which are at the same offset). */
2493 /* The `this' pointer needs to be adjusted from the declaration to
2494 the nearest virtual base. */
2499 /* If the nearest definition is in a lost primary, we don't need an
2500 entry in our vtable. Except possibly in a constructor vtable,
2501 if we happen to get our primary back. In that case, the offset
2502 will be zero, as it will be a primary base. */
2504 else
2505 /* The `this' pointer needs to be adjusted from pointing to
2506 BINFO to pointing at the base where the final overrider
2507 appears. */
2518 else
2522 }
2524 /* Called from modify_all_vtables via dfs_walk. */
2526 static tree
2528 {
2530 tree virtuals;
2531 tree old_virtuals;
2535 /* A base without a vtable needs no modification, and its bases
2536 are uninteresting. */
2541 /* Don't do the primary vtable, if it's new. */
2545 /* There's no need to modify the vtable for a non-virtual primary
2546 base; we're not going to use that vtable anyhow. We do still
2547 need to do this for virtual primary bases, as they could become
2548 non-primary in a construction vtable. */
2553 /* Now, go through each of the virtual functions in the virtual
2554 function table for BINFO. Find the final overrider, and update
2555 the BINFO_VIRTUALS list appropriately. */
2558 virtuals;
2562 binfo,
2567 }
2569 /* Update all of the primary and secondary vtables for T. Create new
2570 vtables as required, and initialize their RTTI information. Each
2571 of the functions in VIRTUALS is declared in T and may override a
2572 virtual function from a base class; find and modify the appropriate
2573 entries to point to the overriding functions. Returns a list, in
2574 declaration order, of the virtual functions that are declared in T,
2575 but do not appear in the primary base class vtable, and which
2576 should therefore be appended to the end of the vtable for T. */
2578 static tree
2580 {
2584 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2588 /* Update all of the vtables. */
2591 /* Add virtual functions not already in our primary vtable. These
2592 will be both those introduced by this class, and those overridden
2593 from secondary bases. It does not include virtuals merely
2594 inherited from secondary bases. */
2596 {
2601 {
2602 /* We don't need to adjust the `this' pointer when
2603 calling this function. */
2607 /* This is a function not already in our vtable. Keep it. */
2609 }
2610 else
2611 /* We've already got an entry for this function. Skip it. */
2613 }
2616 }
2618 /* Get the base virtual function declarations in T that have the
2619 indicated NAME. */
2621 static tree
2623 {
2624 tree methods;
2629 /* Find virtual functions in T with the indicated NAME. */
2633 methods;
2635 {
2641 }
2647 {
2650 base_fndecls);
2651 }
2654 }
2656 /* If this declaration supersedes the declaration of
2657 a method declared virtual in the base class, then
2658 mark this field as being virtual as well. */
2660 void
2662 {
2665 /* In [temp.mem] we have:
2667 A specialization of a member function template does not
2668 override a virtual function from a base class. */
2675 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2676 the error_mark_node so that we know it is an overriding
2677 function. */
2678 {
2681 }
2684 {
2690 }
2695 }
2697 /* Warn about hidden virtual functions that are not overridden in t.
2698 We know that constructors and destructors don't apply. */
2700 static void
2702 {
2704 tree fns;
2707 /* We go through each separately named virtual function. */
2711 {
2712 tree fn;
2713 tree name;
2714 tree fndecl;
2715 tree base_fndecls;
2716 tree base_binfo;
2717 tree binfo;
2720 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2721 have the same name. Figure out what name that is. */
2723 /* There are no possibly hidden functions yet. */
2725 /* Iterate through all of the base classes looking for possibly
2726 hidden functions. */
2729 {
2732 base_fndecls);
2733 }
2735 /* If there are no functions to hide, continue. */
2739 /* Remove any overridden functions. */
2741 {
2744 {
2748 /* If the method from the base class has the same
2749 signature as the method from the derived class, it
2750 has been overridden. */
2753 else
2755 }
2756 }
2758 /* Now give a warning for all base functions without overriders,
2759 as they are hidden. */
2761 {
2762 /* Here we know it is a hider, and no overrider exists. */
2766 }
2767 }
2768 }
2770 /* Check for things that are invalid. There are probably plenty of other
2771 things we should check for also. */
2773 static void
2775 {
2776 tree field;
2779 {
2787 {
2791 {
2792 /* We're generally only interested in entities the user
2793 declared, but we also find nested classes by noticing
2794 the TYPE_DECL that we create implicitly. You're
2795 allowed to put one anonymous union inside another,
2796 though, so we explicitly tolerate that. We use
2797 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2798 we also allow unnamed types used for defining fields. */
2805 {
2809 else
2813 }
2816 {
2819 else
2821 }
2823 {
2826 else
2828 }
2832 }
2833 }
2834 }
2835 }
2837 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2838 will be used later during class template instantiation.
2839 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2840 a non-static member data (FIELD_DECL), a member function
2841 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2842 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2843 When FRIEND_P is nonzero, T is either a friend class
2844 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2845 (FUNCTION_DECL, TEMPLATE_DECL). */
2847 void
2849 {
2850 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2855 }
2857 /* This function is called from declare_virt_assop_and_dtor via
2858 dfs_walk_all.
2860 DATA is a type that direcly or indirectly inherits the base
2861 represented by BINFO. If BINFO contains a virtual assignment [copy
2862 assignment or move assigment] operator or a virtual constructor,
2863 declare that function in DATA if it hasn't been already declared. */
2865 static tree
2867 {
2875 /* A base without a vtable needs no modification, and its bases
2876 are uninteresting. */
2880 /* If this is a primary base, then we have already looked at the
2881 virtual functions of its vtable. */
2885 {
2889 {
2894 }
2898 }
2901 }
2903 /* If the class type T has a direct or indirect base that contains a
2904 virtual assignment operator or a virtual destructor, declare that
2905 function in T if it hasn't been already declared. */
2907 static void
2909 {
2917 dfs_declare_virt_assop_and_dtor,
2919 }
2921 /* Declare the inheriting constructor for class T inherited from base
2922 constructor CTOR with the parameter array PARMS of size NPARMS. */
2924 static void
2926 {
2927 /* We don't declare an inheriting ctor that would be a default,
2928 copy or move ctor for derived or base. */
2933 {
2937 }
2945 {
2948 }
2949 }
2951 /* Declare all the inheriting constructors for class T inherited from base
2952 constructor CTOR. */
2954 static void
2956 {
2962 {
2966 }
2969 {
2973 }
2974 }
2976 /* Create default constructors, assignment operators, and so forth for
2977 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2978 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2979 the class cannot have a default constructor, copy constructor
2980 taking a const reference argument, or an assignment operator taking
2981 a const reference, respectively. */
2983 static void
2987 {
2995 /* Destructor. */
2997 {
2998 /* In general, we create destructors lazily. */
3003 /* But if this is a Java class, any non-trivial destructor is
3004 invalid, even if compiler-generated. Therefore, if the
3005 destructor is non-trivial we create it now. */
3007 }
3009 /* [class.ctor]
3011 If there is no user-declared constructor for a class, a default
3012 constructor is implicitly declared. */
3014 {
3019 /* This might force the declaration. */
3021 }
3023 /* [class.ctor]
3025 If a class definition does not explicitly declare a copy
3026 constructor, one is declared implicitly. */
3028 {
3034 }
3036 /* If there is no assignment operator, one will be created if and
3037 when it is needed. For now, just record whether or not the type
3038 of the parameter to the assignment operator will be a const or
3039 non-const reference. */
3041 {
3047 }
3049 /* We can't be lazy about declaring functions that might override
3050 a virtual function from a base class. */
3054 {
3058 {
3059 /* declare, then remove the decl */
3068 }
3069 else
3071 }
3072 }
3074 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3075 count the number of fields in TYPE, including anonymous union
3076 members. */
3078 static int
3080 {
3081 tree x;
3084 {
3087 else
3089 }
3091 }
3093 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3094 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3095 elts, starting at offset IDX. */
3097 static int
3099 {
3100 tree x;
3102 {
3105 else
3107 }
3109 }
3111 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3112 starting at offset IDX. */
3114 static int
3118 {
3119 tree values;
3123 }
3125 /* FIELD is a bit-field. We are finishing the processing for its
3126 enclosing type. Issue any appropriate messages and set appropriate
3127 flags. Returns false if an error has been diagnosed. */
3129 static bool
3131 {
3133 tree w;
3135 /* Extract the declared width of the bitfield, which has been
3136 temporarily stashed in DECL_INITIAL. */
3139 /* Remove the bit-field width indicator so that the rest of the
3140 compiler does not treat that value as an initializer. */
3143 /* Detect invalid bit-field type. */
3145 {
3148 }
3149 else
3150 {
3152 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3155 /* detect invalid field size. */
3161 {
3164 }
3166 {
3169 }
3171 {
3174 }
3186 }
3189 {
3193 }
3194 else
3195 {
3196 /* Non-bit-fields are aligned for their type. */
3200 }
3201 }
3203 /* FIELD is a non bit-field. We are finishing the processing for its
3204 enclosing type T. Issue any appropriate messages and set appropriate
3205 flags. */
3207 static void
3209 tree t,
3213 {
3216 /* In C++98 an anonymous union cannot contain any fields which would change
3217 the settings of CANT_HAVE_CONST_CTOR and friends. */
3219 ;
3220 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3221 structs. So, we recurse through their fields here. */
3223 {
3224 tree fields;
3230 }
3231 /* Check members with class type for constructors, destructors,
3232 etc. */
3234 {
3235 /* Never let anything with uninheritable virtuals
3236 make it through without complaint. */
3240 {
3245 field);
3250 field);
3252 {
3256 }
3257 }
3258 else
3259 {
3272 }
3281 }
3286 {
3287 /* `build_class_init_list' does not recognize
3288 non-FIELD_DECLs. */
3292 }
3293 }
3295 /* Check the data members (both static and non-static), class-scoped
3296 typedefs, etc., appearing in the declaration of T. Issue
3297 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3298 declaration order) of access declarations; each TREE_VALUE in this
3299 list is a USING_DECL.
3301 In addition, set the following flags:
3303 EMPTY_P
3304 The class is empty, i.e., contains no non-static data members.
3306 CANT_HAVE_CONST_CTOR_P
3307 This class cannot have an implicitly generated copy constructor
3308 taking a const reference.
3310 CANT_HAVE_CONST_ASN_REF
3311 This class cannot have an implicitly generated assignment
3312 operator taking a const reference.
3314 All of these flags should be initialized before calling this
3315 function.
3317 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3318 fields can be added by adding to this chain. */
3320 static void
3324 {
3332 /* Assume there are no access declarations. */
3334 /* Assume this class has no pointer members. */
3336 /* Assume none of the members of this class have default
3337 initializations. */
3341 {
3349 {
3350 /* Save the access declarations for our caller. */
3353 }
3359 /* If we've gotten this far, it's a data member, possibly static,
3360 or an enumerator. */
3364 /* When this goes into scope, it will be a non-local reference. */
3368 {
3369 /* [class.union]
3371 If a union contains a static data member, or a member of
3372 reference type, the program is ill-formed. */
3374 {
3377 }
3379 {
3384 }
3385 }
3387 /* Perform error checking that did not get done in
3388 grokdeclarator. */
3390 {
3394 }
3396 {
3400 }
3408 /* Now it can only be a FIELD_DECL. */
3413 /* If at least one non-static data member is non-literal, the whole
3414 class becomes non-literal. Note: if the type is incomplete we
3415 will complain later on. */
3419 /* A standard-layout class is a class that:
3420 ...
3421 has the same access control (Clause 11) for all non-static data members,
3422 ... */
3429 /* If this is of reference type, check if it needs an init. */
3431 {
3437 /* ARM $12.6.2: [A member initializer list] (or, for an
3438 aggregate, initialization by a brace-enclosed list) is the
3439 only way to initialize nonstatic const and reference
3440 members. */
3443 }
3448 {
3450 {
3451 warning
3454 x);
3456 }
3460 }
3463 /* We don't treat zero-width bitfields as making a class
3464 non-empty. */
3465 ;
3466 else
3467 {
3468 /* The class is non-empty. */
3470 /* The class is not even nearly empty. */
3472 /* If one of the data members contains an empty class,
3473 so does T. */
3477 }
3479 /* This is used by -Weffc++ (see below). Warn only for pointers
3480 to members which might hold dynamic memory. So do not warn
3481 for pointers to functions or pointers to members. */
3487 {
3492 }
3498 /* DR 148 now allows pointers to members (which are POD themselves),
3499 to be allowed in POD structs. */
3508 /* We set DECL_C_BIT_FIELD in grokbitfield.
3509 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3512 cant_have_const_ctor_p,
3513 no_const_asn_ref_p,
3516 /* Now that we've removed bit-field widths from DECL_INITIAL,
3517 anything left in DECL_INITIAL is an NSDMI that makes the class
3518 non-aggregate. */
3522 /* If any field is const, the structure type is pseudo-const. */
3524 {
3529 /* ARM $12.6.2: [A member initializer list] (or, for an
3530 aggregate, initialization by a brace-enclosed list) is the
3531 only way to initialize nonstatic const and reference
3532 members. */
3535 }
3536 /* A field that is pseudo-const makes the structure likewise. */
3538 {
3543 }
3545 /* Core issue 80: A nonstatic data member is required to have a
3546 different name from the class iff the class has a
3547 user-declared constructor. */
3551 }
3553 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3554 it should also define a copy constructor and an assignment operator to
3555 implement the correct copy semantic (deep vs shallow, etc.). As it is
3556 not feasible to check whether the constructors do allocate dynamic memory
3557 and store it within members, we approximate the warning like this:
3559 -- Warn only if there are members which are pointers
3560 -- Warn only if there is a non-trivial constructor (otherwise,
3561 there cannot be memory allocated).
3562 -- Warn only if there is a non-trivial destructor. We assume that the
3563 user at least implemented the cleanup correctly, and a destructor
3564 is needed to free dynamic memory.
3566 This seems enough for practical purposes. */
3568 && has_pointers
3572 {
3576 {
3581 }
3585 }
3587 /* Non-static data member initializers make the default constructor
3588 non-trivial. */
3590 {
3593 }
3595 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3599 /* Check anonymous struct/anonymous union fields. */
3602 /* We've built up the list of access declarations in reverse order.
3603 Fix that now. */
3605 }
3607 /* If TYPE is an empty class type, records its OFFSET in the table of
3608 OFFSETS. */
3610 static int
3612 {
3613 splay_tree_node n;
3618 /* Record the location of this empty object in OFFSETS. */
3626 type,
3630 }
3632 /* Returns nonzero if TYPE is an empty class type and there is
3633 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3635 static int
3637 {
3638 splay_tree_node n;
3639 tree t;
3644 /* Record the location of this empty object in OFFSETS. */
3654 }
3656 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3657 F for every subobject, passing it the type, offset, and table of
3658 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3659 be traversed.
3661 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3662 than MAX_OFFSET will not be walked.
3664 If F returns a nonzero value, the traversal ceases, and that value
3665 is returned. Otherwise, returns zero. */
3667 static int
3669 subobject_offset_fn f,
3670 tree offset,
3671 splay_tree offsets,
3672 tree max_offset,
3674 {
3678 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3679 stop. */
3687 {
3691 }
3694 {
3695 tree field;
3696 tree binfo;
3699 /* Avoid recursing into objects that are not interesting. */
3703 /* Record the location of TYPE. */
3708 /* Iterate through the direct base classes of TYPE. */
3712 {
3713 tree binfo_offset;
3726 offset,
3728 else
3729 {
3730 tree orig_binfo;
3731 /* We cannot rely on BINFO_OFFSET being set for the base
3732 class yet, but the offsets for direct non-virtual
3733 bases can be calculated by going back to the TYPE. */
3736 offset,
3738 }
3741 f,
3742 binfo_offset,
3743 offsets,
3744 max_offset,
3749 }
3752 {
3756 /* Iterate through the virtual base classes of TYPE. In G++
3757 3.2, we included virtual bases in the direct base class
3758 loop above, which results in incorrect results; the
3759 correct offsets for virtual bases are only known when
3760 working with the most derived type. */
3764 {
3766 f,
3768 offset,
3770 offsets,
3771 max_offset,
3775 }
3776 else
3777 {
3778 /* We still have to walk the primary base, if it is
3779 virtual. (If it is non-virtual, then it was walked
3780 above.) */
3786 {
3787 r = (walk_subobject_offsets
3792 }
3793 }
3794 }
3796 /* Iterate through the fields of TYPE. */
3801 {
3802 tree field_offset;
3806 else
3807 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3811 f,
3813 offset,
3814 field_offset),
3815 offsets,
3816 max_offset,
3820 }
3821 }
3823 {
3826 tree index;
3828 /* Avoid recursing into objects that are not interesting. */
3833 /* Step through each of the elements in the array. */
3835 /* G++ 3.2 had an off-by-one error here. */
3840 {
3842 f,
3843 offset,
3844 offsets,
3845 max_offset,
3851 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3852 there's no point in iterating through the remaining
3853 elements of the array. */
3856 }
3857 }
3860 }
3862 /* Record all of the empty subobjects of TYPE (either a type or a
3863 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3864 is being placed at OFFSET; otherwise, it is a base class that is
3865 being placed at OFFSET. */
3867 static void
3869 tree offset,
3870 splay_tree offsets,
3872 {
3873 tree max_offset;
3874 /* If recording subobjects for a non-static data member or a
3875 non-empty base class , we do not need to record offsets beyond
3876 the size of the biggest empty class. Additional data members
3877 will go at the end of the class. Additional base classes will go
3878 either at offset zero (if empty, in which case they cannot
3879 overlap with offsets past the size of the biggest empty class) or
3880 at the end of the class.
3882 However, if we are placing an empty base class, then we must record
3883 all offsets, as either the empty class is at offset zero (where
3884 other empty classes might later be placed) or at the end of the
3885 class (where other objects might then be placed, so other empty
3886 subobjects might later overlap). */
3890 else
3894 }
3896 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3897 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3898 virtual bases of TYPE are examined. */
3900 static int
3902 tree offset,
3903 splay_tree offsets,
3905 {
3906 splay_tree_node max_node;
3908 /* Get the node in OFFSETS that indicates the maximum offset where
3909 an empty subobject is located. */
3911 /* If there aren't any empty subobjects, then there's no point in
3912 performing this check. */
3918 vbases_p);
3919 }
3921 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3922 non-static data member of the type indicated by RLI. BINFO is the
3923 binfo corresponding to the base subobject, OFFSETS maps offsets to
3924 types already located at those offsets. This function determines
3925 the position of the DECL. */
3927 static void
3929 tree decl,
3930 tree binfo,
3931 splay_tree offsets)
3932 {
3935 tree type;
3938 {
3939 /* For the purposes of determining layout conflicts, we want to
3940 use the class type of BINFO; TREE_TYPE (DECL) will be the
3941 CLASSTYPE_AS_BASE version, which does not contain entries for
3942 zero-sized bases. */
3945 }
3946 else
3947 {
3950 }
3952 /* Try to place the field. It may take more than one try if we have
3953 a hard time placing the field without putting two objects of the
3954 same type at the same address. */
3956 {
3959 /* Place this field. */
3963 /* We have to check to see whether or not there is already
3964 something of the same type at the offset we're about to use.
3965 For example, consider:
3967 struct S {};
3968 struct T : public S { int i; };
3969 struct U : public S, public T {};
3971 Here, we put S at offset zero in U. Then, we can't put T at
3972 offset zero -- its S component would be at the same address
3973 as the S we already allocated. So, we have to skip ahead.
3974 Since all data members, including those whose type is an
3975 empty class, have nonzero size, any overlap can happen only
3976 with a direct or indirect base-class -- it can't happen with
3977 a data member. */
3978 /* In a union, overlap is permitted; all members are placed at
3979 offset zero. */
3982 /* G++ 3.2 did not check for overlaps when placing a non-empty
3983 virtual base. */
3988 {
3989 /* Strip off the size allocated to this field. That puts us
3990 at the first place we could have put the field with
3991 proper alignment. */
3994 /* Bump up by the alignment required for the type. */
3995 rli->bitpos
4001 }
4002 else
4003 /* There was no conflict. We're done laying out this field. */
4005 }
4007 /* Now that we know where it will be placed, update its
4008 BINFO_OFFSET. */
4010 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4011 this point because their BINFO_OFFSET is copied from another
4012 hierarchy. Therefore, we may not need to add the entire
4013 OFFSET. */
4019 }
4021 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4023 static int
4025 tree offset,
4027 {
4029 }
4031 /* Layout the empty base BINFO. EOC indicates the byte currently just
4032 past the end of the class, and should be correctly aligned for a
4033 class of the type indicated by BINFO; OFFSETS gives the offsets of
4034 the empty bases allocated so far. T is the most derived
4035 type. Return nonzero iff we added it at the end. */
4037 static bool
4040 {
4041 tree alignment;
4045 /* This routine should only be used for empty classes. */
4050 {
4052 propagate_binfo_offsets
4055 else
4057 "offset of empty base %qT may not be ABI-compliant and may"
4060 }
4062 /* This is an empty base class. We first try to put it at offset
4063 zero. */
4066 offsets,
4068 {
4069 /* That didn't work. Now, we move forward from the next
4070 available spot in the class. */
4074 {
4077 offsets,
4079 /* We finally found a spot where there's no overlap. */
4082 /* There's overlap here, too. Bump along to the next spot. */
4084 }
4085 }
4088 {
4093 }
4096 }
4098 /* Layout the base given by BINFO in the class indicated by RLI.
4099 *BASE_ALIGN is a running maximum of the alignments of
4100 any base class. OFFSETS gives the location of empty base
4101 subobjects. T is the most derived type. Return nonzero if the new
4102 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4103 *NEXT_FIELD, unless BINFO is for an empty base class.
4105 Returns the location at which the next field should be inserted. */
4110 {
4115 /* This error is now reported in xref_tag, thus giving better
4116 location information. */
4119 /* Place the base class. */
4121 {
4122 tree decl;
4124 /* The containing class is non-empty because it has a non-empty
4125 base class. */
4128 /* Create the FIELD_DECL. */
4135 {
4143 /* Try to place the field. It may take more than one try if we
4144 have a hard time placing the field without putting two
4145 objects of the same type at the same address. */
4147 /* Add the new FIELD_DECL to the list of fields for T. */
4151 }
4152 }
4153 else
4154 {
4155 tree eoc;
4158 /* On some platforms (ARM), even empty classes will not be
4159 byte-aligned. */
4164 /* A nearly-empty class "has no proper base class that is empty,
4165 not morally virtual, and at an offset other than zero." */
4167 {
4170 /* The check above (used in G++ 3.2) is insufficient because
4171 an empty class placed at offset zero might itself have an
4172 empty base at a nonzero offset. */
4174 empty_base_at_nonzero_offset_p,
4175 size_zero_node,
4179 {
4182 else
4184 "class %qT will be considered nearly empty in a "
4186 }
4187 }
4189 /* We do not create a FIELD_DECL for empty base classes because
4190 it might overlap some other field. We want to be able to
4191 create CONSTRUCTORs for the class by iterating over the
4192 FIELD_DECLs, and the back end does not handle overlapping
4193 FIELD_DECLs. */
4195 /* An empty virtual base causes a class to be non-empty
4196 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4197 here because that was already done when the virtual table
4198 pointer was created. */
4199 }
4201 /* Record the offsets of BINFO and its base subobjects. */
4204 offsets,
4208 }
4210 /* Layout all of the non-virtual base classes. Record empty
4211 subobjects in OFFSETS. T is the most derived type. Return nonzero
4212 if the type cannot be nearly empty. The fields created
4213 corresponding to the base classes will be inserted at
4214 *NEXT_FIELD. */
4216 static void
4219 {
4220 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4221 subobjects. */
4226 /* The primary base class is always allocated first. */
4231 /* Now allocate the rest of the bases. */
4233 {
4234 tree base_binfo;
4238 /* The primary base was already allocated above, so we don't
4239 need to allocate it again here. */
4243 /* Virtual bases are added at the end (a primary virtual base
4244 will have already been added). */
4250 }
4251 }
4253 /* Go through the TYPE_METHODS of T issuing any appropriate
4254 diagnostics, figuring out which methods override which other
4255 methods, and so forth. */
4257 static void
4259 {
4260 tree x;
4263 {
4267 /* The name of the field is the original field name
4268 Save this in auxiliary field for later overloading. */
4270 {
4274 }
4275 /* All user-provided destructors are non-trivial.
4276 Constructors and assignment ops are handled in
4277 grok_special_member_properties. */
4280 }
4281 }
4283 /* FN is a constructor or destructor. Clone the declaration to create
4284 a specialized in-charge or not-in-charge version, as indicated by
4285 NAME. */
4287 static tree
4289 {
4290 tree parms;
4291 tree clone;
4293 /* Copy the function. */
4295 /* Reset the function name. */
4298 /* Remember where this function came from. */
4300 /* Make it easy to find the CLONE given the FN. */
4304 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4306 {
4313 }
4316 /* There's no pending inline data for this function. */
4320 /* The base-class destructor is not virtual. */
4322 {
4326 }
4328 /* If there was an in-charge parameter, drop it from the function
4329 type. */
4331 {
4332 tree basetype;
4333 tree parmtypes;
4334 tree exceptions;
4339 /* Skip the `this' parameter. */
4341 /* Skip the in-charge parameter. */
4343 /* And the VTT parm, in a complete [cd]tor. */
4347 /* If this is subobject constructor or destructor, add the vtt
4348 parameter. */
4352 parmtypes);
4355 exceptions);
4359 }
4361 /* Copy the function parameters. */
4363 /* Remove the in-charge parameter. */
4365 {
4369 }
4370 /* And the VTT parm, in a complete [cd]tor. */
4372 {
4375 else
4376 {
4380 }
4381 }
4384 {
4387 }
4389 /* Create the RTL for this function. */
4397 }
4399 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4400 not invoke this function directly.
4402 For a non-thunk function, returns the address of the slot for storing
4403 the function it is a clone of. Otherwise returns NULL_TREE.
4405 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4406 cloned_function is unset. This is to support the separate
4407 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4408 on a template makes sense, but not the former. */
4410 tree *
4412 {
4420 {
4421 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4424 else
4425 #endif
4427 }
4432 else
4434 }
4436 /* Produce declarations for all appropriate clones of FN. If
4437 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4438 CLASTYPE_METHOD_VEC as well. */
4440 void
4442 {
4443 tree clone;
4445 /* Avoid inappropriate cloning. */
4451 {
4452 /* For each constructor, we need two variants: an in-charge version
4453 and a not-in-charge version. */
4460 }
4461 else
4462 {
4465 /* For each destructor, we need three variants: an in-charge
4466 version, a not-in-charge version, and an in-charge deleting
4467 version. We clone the deleting version first because that
4468 means it will go second on the TYPE_METHODS list -- and that
4469 corresponds to the correct layout order in the virtual
4470 function table.
4472 For a non-virtual destructor, we do not build a deleting
4473 destructor. */
4475 {
4479 }
4486 }
4488 /* Note that this is an abstract function that is never emitted. */
4490 }
4492 /* DECL is an in charge constructor, which is being defined. This will
4493 have had an in class declaration, from whence clones were
4494 declared. An out-of-class definition can specify additional default
4495 arguments. As it is the clones that are involved in overload
4496 resolution, we must propagate the information from the DECL to its
4497 clones. */
4499 void
4501 {
4502 tree clone;
4506 {
4513 /* Skip the 'this' parameter. */
4529 {
4534 {
4535 /* A default parameter has been added. Adjust the
4536 clone's parameters. */
4540 tree type;
4545 {
4548 clone_parms);
4550 }
4553 clone_parms);
4562 }
4563 }
4565 }
4566 }
4568 /* For each of the constructors and destructors in T, create an
4569 in-charge and not-in-charge variant. */
4571 static void
4573 {
4574 tree fns;
4576 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4577 out now. */
4585 }
4587 /* Deduce noexcept for a destructor DTOR. */
4589 void
4591 {
4593 {
4600 }
4601 }
4603 /* For each destructor in T, deduce noexcept:
4605 12.4/3: A declaration of a destructor that does not have an
4606 exception-specification is implicitly considered to have the
4607 same exception-specification as an implicit declaration (15.4). */
4609 static void
4611 {
4612 tree fns;
4614 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4615 out now. */
4621 }
4623 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4624 of TYPE for virtual functions which FNDECL overrides. Return a
4625 mask of the tm attributes found therein. */
4627 static int
4629 {
4631 tree base_binfo;
4635 {
4645 else
4647 }
4650 }
4652 /* Subroutine of set_method_tm_attributes. Handle the checks and
4653 inheritance for one virtual method FNDECL. */
4655 static void
4657 {
4658 tree tm_attr;
4663 /* If FNDECL doesn't actually override anything (i.e. T is the
4664 class that first declares FNDECL virtual), then we're done. */
4671 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4672 tm_pure must match exactly, otherwise no weakening of
4673 tm_safe > tm_callable > nothing. */
4674 /* ??? The tm_pure attribute didn't make the transition to the
4675 multivendor language spec. */
4677 {
4679 {
4682 }
4683 }
4684 /* If the overridden function is tm_pure, then FNDECL must be. */
4687 /* Look for base class combinations that cannot be satisfied. */
4689 {
4695 }
4696 /* If FNDECL did not declare an attribute, then inherit the most
4697 restrictive one. */
4699 {
4701 }
4702 /* Otherwise validate that we're not weaker than a function
4703 that is being overridden. */
4704 else
4705 {
4709 }
4712 err_override:
4716 }
4718 /* For each of the methods in T, propagate a class-level tm attribute. */
4720 static void
4722 {
4725 /* Don't bother collecting tm attributes if transactional memory
4726 support is not enabled. */
4730 /* Process virtual methods first, as they inherit directly from the
4731 base virtual function and also require validation of new attributes. */
4733 {
4734 tree vchain;
4737 {
4742 }
4743 }
4745 /* If the class doesn't have an attribute, nothing more to do. */
4750 /* Any method that does not yet have a tm attribute inherits
4751 the one from the class. */
4753 {
4756 }
4757 }
4759 /* Returns true iff class T has a user-defined constructor other than
4760 the default constructor. */
4762 bool
4764 {
4765 tree fns;
4771 {
4778 }
4781 }
4783 /* Returns the defaulted constructor if T has one. Otherwise, returns
4784 NULL_TREE. */
4786 tree
4788 {
4795 {
4799 {
4805 }
4806 }
4809 }
4811 /* Returns true iff FN is a user-provided function, i.e. user-declared
4812 and not defaulted at its first declaration; or explicit, private,
4813 protected, or non-const. */
4815 bool
4817 {
4820 else
4823 }
4825 /* Returns true iff class T has a user-provided constructor. */
4827 bool
4829 {
4830 tree fns;
4838 /* This can happen in error cases; avoid crashing. */
4847 }
4849 /* Returns true iff class T has a user-provided default constructor. */
4851 bool
4853 {
4854 tree fns;
4860 {
4866 }
4869 }
4871 /* TYPE is being used as a virtual base, and has a non-trivial move
4872 assignment. Return true if this is due to there being a user-provided
4873 move assignment in TYPE or one of its subobjects; if there isn't, then
4874 multiple move assignment can't cause any harm. */
4876 bool
4878 {
4879 /* Does the type itself have a user-provided move assignment operator? */
4883 {
4887 }
4889 /* Do any of its bases? */
4891 tree base_binfo;
4896 /* Or non-static data members? */
4898 {
4903 }
4905 /* Seems not. */
4907 }
4909 /* If default-initialization leaves part of TYPE uninitialized, returns
4910 a DECL for the field or TYPE itself (DR 253). */
4912 tree
4914 {
4925 {
4929 }
4934 {
4938 }
4941 }
4943 /* Returns true iff for class T, a trivial synthesized default constructor
4944 would be constexpr. */
4946 bool
4948 {
4949 /* A defaulted trivial default constructor is constexpr
4950 if there is nothing to initialize. */
4953 }
4955 /* Returns true iff class T has a constexpr default constructor. */
4957 bool
4959 {
4960 tree fns;
4963 {
4964 /* The caller should have stripped an enclosing array. */
4967 }
4969 {
4972 /* Non-trivial, we need to check subobject constructors. */
4974 }
4977 }
4979 /* Returns true iff class TYPE has a virtual destructor. */
4981 bool
4983 {
4984 tree dtor;
4992 }
4994 /* Returns true iff class T has a move constructor. */
4996 bool
4998 {
4999 tree fns;
5002 {
5005 }
5015 }
5017 /* Returns true iff class T has a move assignment operator. */
5019 bool
5021 {
5022 tree fns;
5025 {
5028 }
5036 }
5038 /* Returns true iff class T has a move constructor that was explicitly
5039 declared in the class body. Note that this is different from
5040 "user-provided", which doesn't include functions that are defaulted in
5041 the class. */
5043 bool
5045 {
5046 tree fns;
5055 {
5059 }
5062 }
5064 /* Returns true iff class T has a move assignment operator that was
5065 explicitly declared in the class body. */
5067 bool
5069 {
5070 tree fns;
5077 {
5081 }
5084 }
5086 /* Nonzero if we need to build up a constructor call when initializing an
5087 object of this class, either because it has a user-provided constructor
5088 or because it doesn't have a default constructor (so we need to give an
5089 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5090 what you care about is whether or not an object can be produced by a
5091 constructor (e.g. so we don't set TREE_READONLY on const variables of
5092 such type); use this function when what you care about is whether or not
5093 to try to call a constructor to create an object. The latter case is
5094 the former plus some cases of constructors that cannot be called. */
5096 bool
5098 {
5099 tree inner;
5105 }
5107 /* Remove all zero-width bit-fields from T. */
5109 static void
5111 {
5116 {
5119 /* We should not be confused by the fact that grokbitfield
5120 temporarily sets the width of the bit field into
5121 DECL_INITIAL (*fieldsp).
5122 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5123 to that width. */
5126 else
5128 }
5129 }
5131 /* Returns TRUE iff we need a cookie when dynamically allocating an
5132 array whose elements have the indicated class TYPE. */
5134 static bool
5136 {
5137 tree fns;
5142 /* If there's a non-trivial destructor, we need a cookie. In order
5143 to iterate through the array calling the destructor for each
5144 element, we'll have to know how many elements there are. */
5148 /* If the usual deallocation function is a two-argument whose second
5149 argument is of type `size_t', then we have to pass the size of
5150 the array to the deallocation function, so we will need to store
5151 a cookie. */
5155 /* If there are no `operator []' members, or the lookup is
5156 ambiguous, then we don't need a cookie. */
5159 /* Loop through all of the functions. */
5161 {
5162 tree fn;
5163 tree second_parm;
5165 /* Select the current function. */
5167 /* See if this function is a one-argument delete function. If
5168 it is, then it will be the usual deallocation function. */
5172 /* Do not consider this function if its second argument is an
5173 ellipsis. */
5176 /* Otherwise, if we have a two-argument function and the second
5177 argument is `size_t', it will be the usual deallocation
5178 function -- unless there is one-argument function, too. */
5182 }
5185 }
5187 /* Finish computing the `literal type' property of class type T.
5189 At this point, we have already processed base classes and
5190 non-static data members. We need to check whether the copy
5191 constructor is trivial, the destructor is trivial, and there
5192 is a trivial default constructor or at least one constexpr
5193 constructor other than the copy constructor. */
5195 static void
5197 {
5198 tree fn;
5214 {
5217 {
5221 }
5222 }
5223 }
5225 /* T is a non-literal type used in a context which requires a constant
5226 expression. Explain why it isn't literal. */
5228 void
5230 {
5240 /* Already explained. */
5249 {
5251 "default constructor, and has no constexpr constructor that "
5255 {
5256 /* Note that we can't simply call locate_ctor because when the
5257 constructor is deleted it just returns NULL_TREE. */
5258 tree fns;
5260 {
5267 {
5270 else
5273 }
5274 }
5275 }
5276 }
5277 else
5278 {
5282 {
5285 {
5290 }
5291 }
5293 {
5294 tree ftype;
5299 {
5304 }
5305 }
5306 }
5307 }
5309 /* Check the validity of the bases and members declared in T. Add any
5310 implicitly-generated functions (like copy-constructors and
5311 assignment operators). Compute various flag bits (like
5312 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5313 level: i.e., independently of the ABI in use. */
5315 static void
5317 {
5318 /* Nonzero if the implicitly generated copy constructor should take
5319 a non-const reference argument. */
5321 /* Nonzero if the implicitly generated assignment operator
5322 should take a non-const reference argument. */
5324 tree access_decls;
5327 tree fn;
5329 /* By default, we use const reference arguments and generate default
5330 constructors. */
5334 /* Check all the base-classes. */
5338 /* Deduce noexcept on destructors. This needs to happen after we've set
5339 triviality flags appropriately for our bases. */
5343 /* Check all the method declarations. */
5346 /* Save the initial values of these flags which only indicate whether
5347 or not the class has user-provided functions. As we analyze the
5348 bases and members we can set these flags for other reasons. */
5352 /* Check all the data member declarations. We cannot call
5353 check_field_decls until we have called check_bases check_methods,
5354 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5355 being set appropriately. */
5360 /* A nearly-empty class has to be vptr-containing; a nearly empty
5361 class contains just a vptr. */
5365 /* Do some bookkeeping that will guide the generation of implicitly
5366 declared member functions. */
5369 /* We need to call a constructor for this class if it has a
5370 user-provided constructor, or if the default constructor is going
5371 to initialize the vptr. (This is not an if-and-only-if;
5372 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5373 themselves need constructing.) */
5376 /* [dcl.init.aggr]
5378 An aggregate is an array or a class with no user-provided
5379 constructors ... and no virtual functions.
5381 Again, other conditions for being an aggregate are checked
5382 elsewhere. */
5385 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5386 retain the old definition internally for ABI reasons. */
5395 /* If the class has no user-declared constructor, but does have
5396 non-static const or reference data members that can never be
5397 initialized, issue a warning. */
5399 /* Classes with user-declared constructors are presumed to
5400 initialize these members. */
5402 /* Aggregates can be initialized with brace-enclosed
5403 initializers. */
5405 {
5406 tree field;
5409 {
5410 tree type;
5425 }
5426 }
5428 /* Synthesize any needed methods. */
5430 cant_have_const_ctor,
5431 no_const_asn_ref);
5433 /* Check defaulted declarations here so we have cant_have_const_ctor
5434 and don't need to worry about clones. */
5437 {
5440 {
5441 bool imp_const_p
5447 /* If the function is defaulted outside the class, we just
5448 give the synthesis error. */
5451 }
5453 }
5456 {
5457 /* "The closure type associated with a lambda-expression has a deleted
5458 default constructor and a deleted copy assignment operator." */
5464 /* "This class type is not an aggregate." */
5466 }
5468 /* Compute the 'literal type' property before we
5469 do anything with non-static member functions. */
5472 /* Create the in-charge and not-in-charge variants of constructors
5473 and destructors. */
5476 /* Process the using-declarations. */
5480 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5483 /* Figure out whether or not we will need a cookie when dynamically
5484 allocating an array of this type. */
5487 }
5489 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5490 accordingly. If a new vfield was created (because T doesn't have a
5491 primary base class), then the newly created field is returned. It
5492 is not added to the TYPE_FIELDS list; it is the caller's
5493 responsibility to do that. Accumulate declared virtual functions
5494 on VIRTUALS_P. */
5496 static tree
5498 {
5499 tree fn;
5501 /* Collect the virtual functions declared in T. */
5505 {
5514 }
5516 /* If we couldn't find an appropriate base class, create a new field
5517 here. Even if there weren't any new virtual functions, we might need a
5518 new virtual function table if we're supposed to include vptrs in
5519 all classes that need them. */
5521 {
5522 /* We build this decl with vtbl_ptr_type_node, which is a
5523 `vtable_entry_type*'. It might seem more precise to use
5524 `vtable_entry_type (*)[N]' where N is the number of virtual
5525 functions. However, that would require the vtable pointer in
5526 base classes to have a different type than the vtable pointer
5527 in derived classes. We could make that happen, but that
5528 still wouldn't solve all the problems. In particular, the
5529 type-based alias analysis code would decide that assignments
5530 to the base class vtable pointer can't alias assignments to
5531 the derived class vtable pointer, since they have different
5532 types. Thus, in a derived class destructor, where the base
5533 class constructor was inlined, we could generate bad code for
5534 setting up the vtable pointer.
5536 Therefore, we use one type for all vtable pointers. We still
5537 use a type-correct type; it's just doesn't indicate the array
5538 bounds. That's better than using `void*' or some such; it's
5539 cleaner, and it let's the alias analysis code know that these
5540 stores cannot alias stores to void*! */
5541 tree field;
5554 /* This class is non-empty. */
5558 }
5561 }
5563 /* Add OFFSET to all base types of BINFO which is a base in the
5564 hierarchy dominated by T.
5566 OFFSET, which is a type offset, is number of bytes. */
5568 static void
5570 {
5572 tree primary_binfo;
5573 tree base_binfo;
5575 /* Update BINFO's offset. */
5580 offset));
5582 /* Find the primary base class. */
5588 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5589 downwards. */
5591 {
5592 /* Don't do the primary base twice. */
5600 }
5601 }
5603 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5604 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5605 empty subobjects of T. */
5607 static void
5609 {
5610 tree vbase;
5619 {
5620 /* In G++ 3.2, we incorrectly rounded the size before laying out
5621 the virtual bases. */
5623 #ifdef STRUCTURE_SIZE_BOUNDARY
5624 /* Packed structures don't need to have minimum size. */
5627 #endif
5631 }
5633 /* Find the last field. The artificial fields created for virtual
5634 bases will go after the last extant field to date. */
5639 /* Go through the virtual bases, allocating space for each virtual
5640 base that is not already a primary base class. These are
5641 allocated in inheritance graph order. */
5643 {
5648 {
5651 /* This virtual base is not a primary base of any class in the
5652 hierarchy, so we have to add space for it. */
5656 /* If the first virtual base might have been placed at a
5657 lower address, had we started from CLASSTYPE_SIZE, rather
5658 than TYPE_SIZE, issue a warning. There can be both false
5659 positives and false negatives from this warning in rare
5660 cases; to deal with all the possibilities would probably
5661 require performing both layout algorithms and comparing
5662 the results which is not particularly tractable. */
5664 && first_vbase
5665 && (tree_int_cst_lt
5670 bitsize_unit_node),
5673 "offset of virtual base %qT is not ABI-compliant and "
5675 basetype);
5678 }
5679 }
5680 }
5682 /* Returns the offset of the byte just past the end of the base class
5683 BINFO. */
5685 static tree
5687 {
5688 tree size;
5693 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5694 allocate some space for it. It cannot have virtual bases, so
5695 TYPE_SIZE_UNIT is fine. */
5697 else
5701 }
5703 /* Returns the offset of the byte just past the end of the base class
5704 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5705 only non-virtual bases are included. */
5707 static tree
5709 {
5712 tree binfo;
5713 tree base_binfo;
5714 tree offset;
5719 {
5729 }
5731 /* G++ 3.2 did not check indirect virtual bases. */
5735 {
5739 }
5742 }
5744 /* Warn about bases of T that are inaccessible because they are
5745 ambiguous. For example:
5747 struct S {};
5748 struct T : public S {};
5749 struct U : public S, public T {};
5751 Here, `(S*) new U' is not allowed because there are two `S'
5752 subobjects of U. */
5754 static void
5756 {
5759 tree basetype;
5760 tree binfo;
5761 tree base_binfo;
5763 /* If there are no repeated bases, nothing can be ambiguous. */
5767 /* Check direct bases. */
5770 {
5776 }
5778 /* Check for ambiguous virtual bases. */
5782 {
5788 }
5789 }
5791 /* Compare two INTEGER_CSTs K1 and K2. */
5793 static int
5795 {
5797 }
5799 /* Increase the size indicated in RLI to account for empty classes
5800 that are "off the end" of the class. */
5802 static void
5804 {
5805 tree eoc;
5806 tree rli_size;
5808 /* It might be the case that we grew the class to allocate a
5809 zero-sized base class. That won't be reflected in RLI, yet,
5810 because we are willing to overlay multiple bases at the same
5811 offset. However, now we need to make sure that RLI is big enough
5812 to reflect the entire class. */
5818 {
5820 /* In version 1 of the ABI, the size of a class that ends with
5821 a bitfield was not rounded up to a whole multiple of a
5822 byte. Because rli_size_unit_so_far returns only the number
5823 of fully allocated bytes, any extra bits were not included
5824 in the size. */
5826 else
5827 /* The size should have been rounded to a whole byte. */
5830 rli->bitpos
5839 }
5840 }
5842 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5843 BINFO_OFFSETs for all of the base-classes. Position the vtable
5844 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5846 static void
5848 {
5849 tree non_static_data_members;
5850 tree field;
5851 tree vptr;
5852 record_layout_info rli;
5853 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5854 types that appear at that offset. */
5855 splay_tree empty_base_offsets;
5856 /* True if the last field layed out was a bit-field. */
5858 /* The location at which the next field should be inserted. */
5860 /* T, as a base class. */
5861 tree base_t;
5863 /* Keep track of the first non-static data member. */
5866 /* Start laying out the record. */
5869 /* Mark all the primary bases in the hierarchy. */
5872 /* Create a pointer to our virtual function table. */
5875 /* The vptr is always the first thing in the class. */
5877 {
5882 }
5883 else
5886 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5891 /* Layout the non-static data members. */
5893 {
5894 tree type;
5895 tree padding;
5897 /* We still pass things that aren't non-static data members to
5898 the back end, in case it wants to do something with them. */
5900 {
5902 /* If the static data member has incomplete type, keep track
5903 of it so that it can be completed later. (The handling
5904 of pending statics in finish_record_layout is
5905 insufficient; consider:
5907 struct S1;
5908 struct S2 { static S1 s1; };
5910 At this point, finish_record_layout will be called, but
5911 S1 is still incomplete.) */
5913 {
5915 /* The visibility of static data members is determined
5916 at their point of declaration, not their point of
5917 definition. */
5919 }
5921 }
5929 /* If this field is a bit-field whose width is greater than its
5930 type, then there are some special rules for allocating
5931 it. */
5934 {
5936 tree integer_type;
5938 /* We must allocate the bits as if suitably aligned for the
5939 longest integer type that fits in this many bits. type
5940 of the field. Then, we are supposed to use the left over
5941 bits as additional padding. */
5950 /* ITK now indicates a type that is too large for the
5951 field. We have to back up by one to find the largest
5952 type that fits. */
5953 do
5954 {
5959 /* Figure out how much additional padding is required. GCC
5960 3.2 always created a padding field, even if it had zero
5961 width. */
5964 {
5966 /* In a union, the padding field must have the full width
5967 of the bit-field; all fields start at offset zero. */
5969 else
5970 {
5973 "ABI-compliant and may change in a future "
5975 t);
5978 }
5979 }
5980 #ifdef PCC_BITFIELD_TYPE_MATTERS
5981 /* An unnamed bitfield does not normally affect the
5982 alignment of the containing class on a target where
5983 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5984 make any exceptions for unnamed bitfields when the
5985 bitfields are longer than their types. Therefore, we
5986 temporarily give the field a name. */
5988 {
5991 }
5992 #endif
5997 empty_base_offsets);
6000 /* Now that layout has been performed, set the size of the
6001 field to the size of its declared type; the rest of the
6002 field is effectively invisible. */
6004 /* We must also reset the DECL_MODE of the field. */
6009 /* Versions of G++ before G++ 3.4 did not reset the
6010 DECL_MODE. */
6012 "the offset of %qD may not be ABI-compliant and may "
6014 }
6015 else
6017 empty_base_offsets);
6019 /* Remember the location of any empty classes in FIELD. */
6023 empty_base_offsets,
6026 /* If a bit-field does not immediately follow another bit-field,
6027 and yet it starts in the middle of a byte, we have failed to
6028 comply with the ABI. */
6031 /* The TREE_NO_WARNING flag gets set by Objective-C when
6032 laying out an Objective-C class. The ObjC ABI differs
6033 from the C++ ABI, and so we do not want a warning
6034 here. */
6036 && !last_field_was_bitfield
6039 bitsize_unit_node)))
6043 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6044 offset of the field. */
6051 "classes to be placed at different locations in a "
6054 /* The middle end uses the type of expressions to determine the
6055 possible range of expression values. In order to optimize
6056 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6057 must be made aware of the width of "i", via its type.
6059 Because C++ does not have integer types of arbitrary width,
6060 we must (for the purposes of the front end) convert from the
6061 type assigned here to the declared type of the bitfield
6062 whenever a bitfield expression is used as an rvalue.
6063 Similarly, when assigning a value to a bitfield, the value
6064 must be converted to the type given the bitfield here. */
6066 {
6071 {
6078 }
6079 }
6081 /* If we needed additional padding after this field, add it
6082 now. */
6084 {
6085 tree padding_field;
6088 FIELD_DECL,
6089 NULL_TREE,
6090 char_type_node);
6097 NULL_TREE,
6098 empty_base_offsets);
6099 }
6102 }
6105 {
6106 /* Make sure that we are on a byte boundary so that the size of
6107 the class without virtual bases will always be a round number
6108 of bytes. */
6111 }
6113 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6114 padding. */
6118 /* Delete all zero-width bit-fields from the list of fields. Now
6119 that the type is laid out they are no longer important. */
6122 /* Create the version of T used for virtual bases. We do not use
6123 make_class_type for this version; this is an artificial type. For
6124 a POD type, we just reuse T. */
6126 {
6129 /* Set the size and alignment for the new type. In G++ 3.2, all
6130 empty classes were considered to have size zero when used as
6131 base classes. */
6133 {
6138 "layout of classes derived from empty class %qT "
6140 t);
6141 }
6142 else
6143 {
6144 tree eoc;
6146 /* If the ABI version is not at least two, and the last
6147 field was a bit-field, RLI may not be on a byte
6148 boundary. In particular, rli_size_unit_so_far might
6149 indicate the last complete byte, while rli_size_so_far
6150 indicates the total number of bits used. Therefore,
6151 rli_size_so_far, rather than rli_size_unit_so_far, is
6152 used to compute TYPE_SIZE_UNIT. */
6160 eoc);
6167 }
6171 /* Copy the fields from T. */
6175 {
6177 FIELD_DECL,
6187 }
6189 /* Record the base version of the type. */
6192 }
6193 else
6196 /* Every empty class contains an empty class. */
6200 /* Set the TYPE_DECL for this type to contain the right
6201 value for DECL_OFFSET, so that we can use it as part
6202 of a COMPONENT_REF for multiple inheritance. */
6205 /* Now fix up any virtual base class types that we left lying
6206 around. We must get these done before we try to lay out the
6207 virtual function table. As a side-effect, this will remove the
6208 base subobject fields. */
6211 /* Make sure that empty classes are reflected in RLI at this
6212 point. */
6215 /* Make sure not to create any structures with zero size. */
6221 /* If this is a non-POD, declaring it packed makes a difference to how it
6222 can be used as a field; don't let finalize_record_size undo it. */
6226 /* Let the back end lay out the type. */
6229 /* Warn about bases that can't be talked about due to ambiguity. */
6232 /* Now that we're done with layout, give the base fields the real types. */
6237 /* Clean up. */
6244 }
6246 /* Determine the "key method" for the class type indicated by TYPE,
6247 and set CLASSTYPE_KEY_METHOD accordingly. */
6249 void
6251 {
6252 tree method;
6255 || processing_template_decl
6260 /* The key method is the first non-pure virtual function that is not
6261 inline at the point of class definition. On some targets the
6262 key function may not be inline; those targets should not call
6263 this function until the end of the translation unit. */
6269 {
6272 }
6275 }
6278 /* Allocate and return an instance of struct sorted_fields_type with
6279 N fields. */
6283 {
6290 }
6293 /* Perform processing required when the definition of T (a class type)
6294 is complete. */
6296 void
6298 {
6299 tree x;
6300 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6304 {
6309 }
6311 /* If this type was previously laid out as a forward reference,
6312 make sure we lay it out again. */
6316 /* Make assumptions about the class; we'll reset the flags if
6317 necessary. */
6323 /* Do end-of-class semantic processing: checking the validity of the
6324 bases and members and add implicitly generated methods. */
6327 /* Find the key method. */
6329 {
6330 /* The Itanium C++ ABI permits the key method to be chosen when
6331 the class is defined -- even though the key method so
6332 selected may later turn out to be an inline function. On
6333 some systems (such as ARM Symbian OS) the key method cannot
6334 be determined until the end of the translation unit. On such
6335 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6336 will cause the class to be added to KEYED_CLASSES. Then, in
6337 finish_file we will determine the key method. */
6341 /* If a polymorphic class has no key method, we may emit the vtable
6342 in every translation unit where the class definition appears. */
6345 }
6347 /* Layout the class itself. */
6350 /* We use the base type for trivial assignments, and hence it
6351 needs a mode. */
6356 /* If necessary, create the primary vtable for this class. */
6358 {
6359 /* We must enter these virtuals into the table. */
6363 /* Here we know enough to change the type of our virtual
6364 function table, but we will wait until later this function. */
6367 /* If we're warning about ABI tags, check the types of the new
6368 virtual functions. */
6372 }
6375 {
6377 tree fn;
6384 /* Add entries for virtual functions introduced by this class. */
6388 /* Set DECL_VINDEX for all functions declared in this class. */
6390 fn;
6392 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6394 {
6398 /* A thunk. We should never be calling this entry directly
6399 from this vtable -- we'd use the entry for the non
6400 thunk base function. */
6404 }
6405 }
6410 /* Complete the rtl for any static member objects of the type we're
6411 working on. */
6418 /* Done with FIELDS...now decide whether to sort these for
6419 faster lookups later.
6421 We use a small number because most searches fail (succeeding
6422 ultimately as the search bores through the inheritance
6423 hierarchy), and we want this failure to occur quickly. */
6427 /* Complain if one of the field types requires lower visibility. */
6430 /* Make the rtl for any new vtables we have created, and unmark
6431 the base types we marked. */
6434 /* Build the VTT for T. */
6437 /* This warning does not make sense for Java classes, since they
6438 cannot have destructors. */
6440 {
6441 tree dtor;
6445 if it were virtual, we would have created it by now. */
6446 !dtor
6455 "%q#T has virtual functions and accessible"
6457 }
6464 /* Class layout, assignment of virtual table slots, etc., is now
6465 complete. Give the back end a chance to tweak the visibility of
6466 the class or perform any other required target modifications. */
6473 /* Finish debugging output for this type. */
6477 {
6480 {
6483 }
6485 {
6488 else
6489 {
6492 }
6494 }
6496 {
6498 "the type of the first field has a different ABI from the "
6501 }
6502 }
6503 }
6505 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6506 equal to THRESHOLD or greater than THRESHOLD. */
6508 static void
6510 {
6513 {
6518 }
6519 }
6521 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6523 void
6525 {
6528 {
6530 int n_fields
6541 }
6542 }
6544 /* When T was built up, the member declarations were added in reverse
6545 order. Rearrange them to declaration order. */
6547 void
6549 {
6550 tree next;
6551 tree prev;
6552 tree x;
6554 /* The following lists are all in reverse order. Put them in
6555 declaration order now. */
6559 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6560 reverse order, so we can't just use nreverse. */
6565 {
6569 }
6571 {
6575 }
6576 }
6578 tree
6580 {
6583 /* Now that we've got all the field declarations, reverse everything
6584 as necessary. */
6589 /* Nadger the current location so that diagnostics point to the start of
6590 the struct, not the end. */
6594 {
6595 tree x;
6601 /* We need to emit an error message if this type was used as a parameter
6602 and it is an abstract type, even if it is a template. We construct
6603 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6604 account and we call complete_vars with this type, which will check
6605 the PARM_DECLS. Note that while the type is being defined,
6606 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6607 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6613 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6614 an enclosing scope is a template class, so that this function be
6615 found by lookup_fnfields_1 when the using declaration is not
6616 instantiated yet. */
6619 {
6624 }
6626 /* Remember current #pragma pack value. */
6629 /* Fix up any variants we've already built. */
6631 {
6636 }
6637 }
6638 else
6647 else
6651 /* Lambdas are defined by the LAMBDA_EXPR. */
6656 }
6657 \f
6658 /* Hash table to avoid endless recursion when handling references. */
6661 /* Return the dynamic type of INSTANCE, if known.
6662 Used to determine whether the virtual function table is needed
6663 or not.
6665 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6666 of our knowledge of its type. *NONNULL should be initialized
6667 before this function is called. */
6669 static tree
6671 {
6672 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6675 {
6679 else
6683 /* This is a call to a constructor, hence it's never zero. */
6685 {
6689 }
6693 /* This is a call to a constructor, hence it's never zero. */
6695 {
6699 }
6708 /* Propagate nonnull. */
6713 CASE_CONVERT:
6719 {
6720 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6721 with a real object -- given &p->f, p can still be null. */
6723 /* ??? Probably should check DECL_WEAK here. */
6726 }
6730 /* If this component is really a base class reference, then the field
6731 itself isn't definitive. */
6740 {
6744 }
6745 /* fall through... */
6750 {
6754 }
6756 {
6760 /* if we're in a ctor or dtor, we know our type. If
6761 current_class_ptr is set but we aren't in a function, we're in
6762 an NSDMI (and therefore a constructor). */
6767 {
6771 }
6772 }
6774 {
6775 /* We only need one hash table because it is always left empty. */
6779 /* Reference variables should be references to objects. */
6783 /* Enter the INSTANCE in a table to prevent recursion; a
6784 variable's initializer may refer to the variable
6785 itself. */
6790 {
6791 tree type;
6800 }
6801 }
6806 }
6807 #undef RECUR
6808 }
6810 /* Return nonzero if the dynamic type of INSTANCE is known, and
6811 equivalent to the static type. We also handle the case where
6812 INSTANCE is really a pointer. Return negative if this is a
6813 ctor/dtor. There the dynamic type is known, but this might not be
6814 the most derived base of the original object, and hence virtual
6815 bases may not be layed out according to this type.
6817 Used to determine whether the virtual function table is needed
6818 or not.
6820 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6821 of our knowledge of its type. *NONNULL should be initialized
6822 before this function is called. */
6824 int
6826 {
6829 tree fixed;
6831 /* processing_template_decl can be false in a template if we're in
6832 fold_non_dependent_expr, but we still want to suppress this check. */
6834 {
6835 /* In a template we only care about the type of the result. */
6839 }
6849 }
6851 \f
6852 void
6854 {
6857 current_class_stack
6865 }
6867 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6869 static void
6871 {
6872 tree type;
6874 /* We are re-entering the same class we just left, so we don't
6875 have to search the whole inheritance matrix to find all the
6876 decls to bind again. Instead, we install the cached
6877 class_shadowed list and walk through it binding names. */
6880 /* Restore IDENTIFIER_TYPE_VALUE. */
6882 type;
6885 }
6887 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6888 appropriate for TYPE.
6890 So that we may avoid calls to lookup_name, we cache the _TYPE
6891 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6893 For multiple inheritance, we perform a two-pass depth-first search
6894 of the type lattice. */
6896 void
6898 {
6899 class_stack_node_t csn;
6903 /* Make sure there is enough room for the new entry on the stack. */
6905 {
6907 current_class_stack
6909 current_class_stack_size);
6910 }
6912 /* Insert a new entry on the class stack. */
6919 current_class_depth++;
6921 /* Now set up the new type. */
6927 /* By default, things in classes are private, while things in
6928 structures or unions are public. */
6930 ? access_private_node
6936 {
6937 /* Forcibly remove any old class remnants. */
6939 }
6945 else
6947 }
6949 /* When we exit a toplevel class scope, we save its binding level so
6950 that we can restore it quickly. Here, we've entered some other
6951 class, so we must invalidate our cache. */
6953 void
6955 {
6957 }
6959 /* Get out of the current class scope. If we were in a class scope
6960 previously, that is the one popped to. */
6962 void
6964 {
6967 current_class_depth--;
6973 }
6975 /* Mark the top of the class stack as hidden. */
6977 void
6979 {
6982 }
6984 /* Mark the top of the class stack as un-hidden. */
6986 void
6988 {
6991 }
6993 /* Returns 1 if the class type currently being defined is either T or
6994 a nested type of T. */
6996 bool
6998 {
7006 /* We start looking from 1 because entry 0 is from global scope,
7007 and has no type. */
7009 {
7010 tree c;
7013 else
7014 {
7018 }
7023 }
7025 }
7027 /* If either current_class_type or one of its enclosing classes are derived
7028 from T, return the appropriate type. Used to determine how we found
7029 something via unqualified lookup. */
7031 tree
7033 {
7036 /* The bases of a dependent type are unknown. */
7047 {
7052 }
7055 }
7057 /* Returns the innermost class type which is not a lambda closure type. */
7059 tree
7061 {
7064 /* We start looking from 1 because entry 0 is from global scope,
7065 and has no type. */
7067 {
7068 tree c;
7071 else
7072 {
7076 }
7081 }
7083 }
7085 /* When entering a class scope, all enclosing class scopes' names with
7086 static meaning (static variables, static functions, types and
7087 enumerators) have to be visible. This recursive function calls
7088 pushclass for all enclosing class contexts until global or a local
7089 scope is reached. TYPE is the enclosed class. */
7091 void
7093 {
7094 /* A namespace might be passed in error cases, like A::B:C. */
7102 }
7104 /* Undoes a push_nested_class call. */
7106 void
7108 {
7114 }
7116 /* Returns the number of extern "LANG" blocks we are nested within. */
7118 int
7120 {
7122 }
7124 /* Set global variables CURRENT_LANG_NAME to appropriate value
7125 so that behavior of name-mangling machinery is correct. */
7127 void
7129 {
7133 {
7135 }
7137 {
7139 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7140 (See record_builtin_java_type in decl.c.) However, that causes
7141 incorrect debug entries if these types are actually used.
7142 So we re-enable debug output after extern "Java". */
7151 }
7153 {
7155 }
7156 else
7158 }
7160 /* Get out of the current language scope. */
7162 void
7164 {
7166 }
7167 \f
7168 /* Type instantiation routines. */
7170 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7171 matches the TARGET_TYPE. If there is no satisfactory match, return
7172 error_mark_node, and issue an error & warning messages under
7173 control of FLAGS. Permit pointers to member function if FLAGS
7174 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7175 a template-id, and EXPLICIT_TARGS are the explicitly provided
7176 template arguments.
7178 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7179 is the base path used to reference those member functions. If
7180 the address is resolved to a member function, access checks will be
7181 performed and errors issued if appropriate. */
7183 static tree
7185 tree overload,
7186 tsubst_flags_t flags,
7188 tree explicit_targs,
7189 tree access_path)
7190 {
7191 /* Here's what the standard says:
7193 [over.over]
7195 If the name is a function template, template argument deduction
7196 is done, and if the argument deduction succeeds, the deduced
7197 arguments are used to generate a single template function, which
7198 is added to the set of overloaded functions considered.
7200 Non-member functions and static member functions match targets of
7201 type "pointer-to-function" or "reference-to-function." Nonstatic
7202 member functions match targets of type "pointer-to-member
7203 function;" the function type of the pointer to member is used to
7204 select the member function from the set of overloaded member
7205 functions. If a nonstatic member function is selected, the
7206 reference to the overloaded function name is required to have the
7207 form of a pointer to member as described in 5.3.1.
7209 If more than one function is selected, any template functions in
7210 the set are eliminated if the set also contains a non-template
7211 function, and any given template function is eliminated if the
7212 set contains a second template function that is more specialized
7213 than the first according to the partial ordering rules 14.5.5.2.
7214 After such eliminations, if any, there shall remain exactly one
7215 selected function. */
7218 /* We store the matches in a TREE_LIST rooted here. The functions
7219 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7220 interoperability with most_specialized_instantiation. */
7222 tree fn;
7223 tree target_fn_type;
7225 /* By the time we get here, we should be seeing only real
7226 pointer-to-member types, not the internal POINTER_TYPE to
7227 METHOD_TYPE representation. */
7233 /* Check that the TARGET_TYPE is reasonable. */
7238 /* This is OK, too. */
7241 /* This is OK, too. This comes from a conversion to reference
7242 type. */
7244 else
7245 {
7251 }
7253 /* Non-member functions and static member functions match targets of type
7254 "pointer-to-function" or "reference-to-function." Nonstatic member
7255 functions match targets of type "pointer-to-member-function;" the
7256 function type of the pointer to member is used to select the member
7257 function from the set of overloaded member functions.
7259 So figure out the FUNCTION_TYPE that we want to match against. */
7262 /* If we can find a non-template function that matches, we can just
7263 use it. There's no point in generating template instantiations
7264 if we're just going to throw them out anyhow. But, of course, we
7265 can only do this when we don't *need* a template function. */
7267 {
7268 tree fns;
7271 {
7275 /* We're not looking for templates just yet. */
7280 /* We're looking for a non-static member, and this isn't
7281 one, or vice versa. */
7284 /* Ignore functions which haven't been explicitly
7285 declared. */
7289 /* See if there's a match. */
7292 }
7293 }
7295 /* Now, if we've already got a match (or matches), there's no need
7296 to proceed to the template functions. But, if we don't have a
7297 match we need to look at them, too. */
7299 {
7300 tree target_arg_types;
7301 tree target_ret_type;
7302 tree fns;
7305 tree arg;
7319 {
7321 tree instantiation;
7322 tree targs;
7325 /* We're only looking for templates. */
7330 /* We're not looking for a non-static member, and this is
7331 one, or vice versa. */
7336 /* If the template has a deduced return type, don't expose it to
7337 template argument deduction. */
7341 /* Try to do argument deduction. */
7348 /* Instantiation failed. */
7351 /* And now force instantiation to do return type deduction. */
7353 {
7359 }
7361 /* See if there's a match. */
7366 }
7368 /* Now, remove all but the most specialized of the matches. */
7370 {
7375 NULL_TREE,
7376 NULL_TREE);
7377 }
7378 }
7380 /* Now we should have exactly one function in MATCHES. */
7382 {
7383 /* There were *no* matches. */
7385 {
7388 target_type);
7391 }
7393 }
7395 {
7396 /* There were too many matches. First check if they're all
7397 the same function. */
7402 /* For multi-versioned functions, more than one match is just fine and
7403 decls_match will return false as they are different. */
7411 {
7413 {
7416 target_type);
7418 /* Since print_candidates expects the functions in the
7419 TREE_VALUE slot, we flip them here. */
7424 }
7427 }
7428 }
7430 /* Good, exactly one match. Now, convert it to the correct type. */
7435 {
7443 {
7446 }
7447 }
7449 /* If a pointer to a function that is multi-versioned is requested, the
7450 pointer to the dispatcher function is returned instead. This works
7451 well because indirectly calling the function will dispatch the right
7452 function version at run-time. */
7454 {
7458 /* Mark all the versions corresponding to the dispatcher as used. */
7461 }
7463 /* If we're doing overload resolution purely for the purpose of
7464 determining conversion sequences, we should not consider the
7465 function used. If this conversion sequence is selected, the
7466 function will be marked as used at this point. */
7468 {
7469 /* Make =delete work with SFINAE. */
7474 }
7476 /* We could not check access to member functions when this
7477 expression was originally created since we did not know at that
7478 time to which function the expression referred. */
7480 {
7483 }
7487 else
7488 {
7489 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7490 will mark the function as addressed, but here we must do it
7491 explicitly. */
7495 }
7496 }
7498 /* This function will instantiate the type of the expression given in
7499 RHS to match the type of LHSTYPE. If errors exist, then return
7500 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7501 we complain on errors. If we are not complaining, never modify rhs,
7502 as overload resolution wants to try many possible instantiations, in
7503 the hope that at least one will work.
7505 For non-recursive calls, LHSTYPE should be a function, pointer to
7506 function, or a pointer to member function. */
7508 tree
7510 {
7517 {
7521 }
7524 {
7531 /* Microsoft allows `A::f' to be resolved to a
7532 pointer-to-member. */
7533 ;
7534 else
7535 {
7540 }
7541 }
7544 {
7547 }
7549 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7550 deduce any type information. */
7552 {
7556 }
7558 /* There only a few kinds of expressions that may have a type
7559 dependent on overload resolution. */
7565 /* This should really only be used when attempting to distinguish
7566 what sort of a pointer to function we have. For now, any
7567 arithmetic operation which is not supported on pointers
7568 is rejected as an error. */
7571 {
7573 {
7579 /* Do not lose object's side effects. */
7583 }
7590 /* This can happen if we are forming a pointer-to-member for a
7591 member template. */
7594 /* Fall through. */
7597 {
7601 return
7605 }
7609 return
7613 access_path);
7616 {
7621 }
7628 }
7630 }
7631 \f
7632 /* Return the name of the virtual function pointer field
7633 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7634 this may have to look back through base types to find the
7635 ultimate field name. (For single inheritance, these could
7636 all be the same name. Who knows for multiple inheritance). */
7638 static tree
7640 {
7647 {
7653 }
7661 }
7663 void
7665 {
7672 {
7677 }
7678 }
7680 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7681 according to [class]:
7682 The class-name is also inserted
7683 into the scope of the class itself. For purposes of access checking,
7684 the inserted class name is treated as if it were a public member name. */
7686 void
7688 {
7691 tree saved_cas;
7706 }
7708 /* Returns 1 if TYPE contains only padding bytes. */
7710 int
7712 {
7719 /* In G++ 3.2, whether or not a class was empty was determined by
7720 looking at its size. */
7723 else
7725 }
7727 /* Returns true if TYPE contains an empty class. */
7729 static bool
7731 {
7735 {
7736 tree field;
7737 tree binfo;
7738 tree base_binfo;
7750 }
7754 }
7756 /* Returns true if TYPE contains no actual data, just various
7757 possible combinations of empty classes and possibly a vptr. */
7759 bool
7761 {
7763 {
7764 tree field;
7765 tree binfo;
7766 tree base_binfo;
7769 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7770 out, but we'd like to be able to check this before then. */
7784 }
7788 }
7790 /* Note that NAME was looked up while the current class was being
7791 defined and that the result of that lookup was DECL. */
7793 void
7795 {
7796 splay_tree names_used;
7798 /* If we're not defining a class, there's nothing to do. */
7804 /* If there's already a binding for this NAME, then we don't have
7805 anything to worry about. */
7818 }
7820 /* Note that NAME was declared (as DECL) in the current class. Check
7821 to see that the declaration is valid. */
7823 void
7825 {
7826 splay_tree names_used;
7827 splay_tree_node n;
7829 /* Look to see if we ever used this name. */
7830 names_used
7834 /* The C language allows members to be declared with a type of the same
7835 name, and the C++ standard says this diagnostic is not required. So
7836 allow it in extern "C" blocks unless predantic is specified.
7837 Allow it in all cases if -ms-extensions is specified. */
7843 {
7844 /* [basic.scope.class]
7846 A name N used in a class S shall refer to the same declaration
7847 in its context and when re-evaluated in the completed scope of
7848 S. */
7852 }
7853 }
7855 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7856 Secondary vtables are merged with primary vtables; this function
7857 will return the VAR_DECL for the primary vtable. */
7859 tree
7861 {
7862 tree decl;
7866 {
7869 }
7873 }
7876 /* Returns the binfo for the primary base of BINFO. If the resulting
7877 BINFO is a virtual base, and it is inherited elsewhere in the
7878 hierarchy, then the returned binfo might not be the primary base of
7879 BINFO in the complete object. Check BINFO_PRIMARY_P or
7880 BINFO_LOST_PRIMARY_P to be sure. */
7882 static tree
7884 {
7885 tree primary_base;
7892 }
7894 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7896 static int
7898 {
7902 }
7904 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7905 INDENT should be zero when called from the top level; it is
7906 incremented recursively. IGO indicates the next expected BINFO in
7907 inheritance graph ordering. */
7909 static tree
7912 tree binfo,
7913 tree igo,
7915 {
7917 tree base_binfo;
7925 {
7928 }
7943 {
7947 TFF_PLAIN_IDENTIFIER),
7949 }
7951 {
7954 }
7959 {
7963 {
7967 TFF_PLAIN_IDENTIFIER));
7968 }
7970 {
7974 TFF_PLAIN_IDENTIFIER));
7975 }
7977 {
7981 TFF_PLAIN_IDENTIFIER));
7982 }
7984 {
7988 TFF_PLAIN_IDENTIFIER));
7989 }
7993 }
7999 }
8001 /* Dump the BINFO hierarchy for T. */
8003 static void
8005 {
8017 }
8019 /* Debug interface to hierarchy dumping. */
8021 void
8023 {
8025 }
8027 static void
8029 {
8034 {
8037 }
8038 }
8040 static void
8042 {
8043 tree value;
8045 HOST_WIDE_INT elt;
8053 TFF_PLAIN_IDENTIFIER));
8060 }
8062 static void
8064 {
8072 {
8079 {
8084 }
8088 }
8091 }
8093 static void
8095 {
8103 {
8108 }
8111 }
8113 /* Dump a function or thunk and its thunkees. */
8115 static void
8117 {
8120 tree thunks;
8128 {
8138 else
8144 }
8148 }
8150 /* Dump the thunks for FN. */
8152 void
8154 {
8156 }
8158 /* Virtual function table initialization. */
8160 /* Create all the necessary vtables for T and its base classes. */
8162 static void
8164 {
8165 tree vbase;
8169 /* We lay out the primary and secondary vtables in one contiguous
8170 vtable. The primary vtable is first, followed by the non-virtual
8171 secondary vtables in inheritance graph order. */
8175 /* Then come the virtual bases, also in inheritance graph order. */
8177 {
8181 }
8185 }
8187 /* Initialize the vtable for BINFO with the INITS. */
8189 static void
8191 {
8192 tree decl;
8198 }
8200 /* Build the VTT (virtual table table) for T.
8201 A class requires a VTT if it has virtual bases.
8203 This holds
8204 1 - primary virtual pointer for complete object T
8205 2 - secondary VTTs for each direct non-virtual base of T which requires a
8206 VTT
8207 3 - secondary virtual pointers for each direct or indirect base of T which
8208 has virtual bases or is reachable via a virtual path from T.
8209 4 - secondary VTTs for each direct or indirect virtual base of T.
8211 Secondary VTTs look like complete object VTTs without part 4. */
8213 static void
8215 {
8216 tree type;
8217 tree vtt;
8218 tree index;
8221 /* Build up the initializers for the VTT. */
8226 /* If we didn't need a VTT, we're done. */
8230 /* Figure out the type of the VTT. */
8234 /* Now, build the VTT object itself. */
8237 /* Add the VTT to the vtables list. */
8242 }
8244 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8245 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8246 and CHAIN the vtable pointer for this binfo after construction is
8247 complete. VALUE can also be another BINFO, in which case we recurse. */
8249 static tree
8251 {
8252 tree vt;
8255 {
8261 else
8263 }
8266 }
8268 /* Data for secondary VTT initialization. */
8270 {
8271 /* Is this the primary VTT? */
8274 /* Current index into the VTT. */
8275 tree index;
8277 /* Vector of initializers built up. */
8280 /* The type being constructed by this secondary VTT. */
8281 tree type_being_constructed;
8284 /* Recursively build the VTT-initializer for BINFO (which is in the
8285 hierarchy dominated by T). INITS points to the end of the initializer
8286 list to date. INDEX is the VTT index where the next element will be
8287 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8288 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8289 for virtual bases of T. When it is not so, we build the constructor
8290 vtables for the BINFO-in-T variant. */
8292 static void
8295 {
8297 tree b;
8298 tree init;
8299 secondary_vptr_vtt_init_data data;
8302 /* We only need VTTs for subobjects with virtual bases. */
8306 /* We need to use a construction vtable if this is not the primary
8307 VTT. */
8309 {
8312 /* Record the offset in the VTT where this sub-VTT can be found. */
8314 }
8316 /* Add the address of the primary vtable for the complete object. */
8320 {
8323 }
8326 /* Recursively add the secondary VTTs for non-virtual bases. */
8331 /* Add secondary virtual pointers for all subobjects of BINFO with
8332 either virtual bases or reachable along a virtual path, except
8333 subobjects that are non-virtual primary bases. */
8343 /* data.inits might have grown as we added secondary virtual pointers.
8344 Make sure our caller knows about the new vector. */
8348 /* Add the secondary VTTs for virtual bases in inheritance graph
8349 order. */
8351 {
8356 }
8357 else
8358 /* Remove the ctor vtables we created. */
8360 }
8362 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8363 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8365 static tree
8367 {
8370 /* We don't care about bases that don't have vtables. */
8374 /* We're only interested in proper subobjects of the type being
8375 constructed. */
8379 /* We're only interested in bases with virtual bases or reachable
8380 via a virtual path from the type being constructed. */
8385 /* We're not interested in non-virtual primary bases. */
8389 /* Record the index where this secondary vptr can be found. */
8391 {
8396 {
8397 /* It's a primary virtual base, and this is not a
8398 construction vtable. Find the base this is primary of in
8399 the inheritance graph, and use that base's vtable
8400 now. */
8403 }
8404 }
8406 /* Add the initializer for the secondary vptr itself. */
8409 /* Advance the vtt index. */
8414 }
8416 /* Called from build_vtt_inits via dfs_walk. After building
8417 constructor vtables and generating the sub-vtt from them, we need
8418 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8419 binfo of the base whose sub vtt was generated. */
8421 static tree
8423 {
8427 /* If this class has no vtable, none of its bases do. */
8431 /* This might be a primary base, so have no vtable in this
8432 hierarchy. */
8435 /* If we scribbled the construction vtable vptr into BINFO, clear it
8436 out now. */
8442 }
8444 /* Build the construction vtable group for BINFO which is in the
8445 hierarchy dominated by T. */
8447 static void
8449 {
8450 tree type;
8451 tree vtbl;
8452 tree id;
8453 tree vbase;
8456 /* See if we've already created this construction vtable group. */
8462 /* Build a version of VTBL (with the wrong type) for use in
8463 constructing the addresses of secondary vtables in the
8464 construction vtable group. */
8467 /* Don't export construction vtables from shared libraries. Even on
8468 targets that don't support hidden visibility, this tells
8469 can_refer_decl_in_current_unit_p not to assume that it's safe to
8470 access from a different compilation unit (bz 54314). */
8478 /* Add the vtables for each of our virtual bases using the vbase in T
8479 binfo. */
8481 vbase;
8483 {
8484 tree b;
8491 }
8493 /* Figure out the type of the construction vtable. */
8500 /* Initialize the construction vtable. */
8504 }
8506 /* Add the vtbl initializers for BINFO (and its bases other than
8507 non-virtual primaries) to the list of INITS. BINFO is in the
8508 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8509 the constructor the vtbl inits should be accumulated for. (If this
8510 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8511 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8512 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8513 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8514 but are not necessarily the same in terms of layout. */
8516 static void
8518 tree orig_binfo,
8519 tree rtti_binfo,
8520 tree vtbl,
8521 tree t,
8523 {
8525 tree base_binfo;
8530 /* If it doesn't have a vptr, we don't do anything. */
8534 /* If we're building a construction vtable, we're not interested in
8535 subobjects that don't require construction vtables. */
8541 /* Build the initializers for the BINFO-in-T vtable. */
8544 /* Walk the BINFO and its bases. We walk in preorder so that as we
8545 initialize each vtable we can figure out at what offset the
8546 secondary vtable lies from the primary vtable. We can't use
8547 dfs_walk here because we need to iterate through bases of BINFO
8548 and RTTI_BINFO simultaneously. */
8550 {
8551 /* Skip virtual bases. */
8557 inits);
8558 }
8559 }
8561 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8562 BINFO vtable to L. */
8564 static void
8566 tree orig_binfo,
8567 tree rtti_binfo,
8568 tree orig_vtbl,
8569 tree t,
8571 {
8578 {
8579 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8580 primary virtual base. If it is not the same primary in
8581 the hierarchy of T, we'll need to generate a ctor vtable
8582 for it, to place at its location in T. If it is the same
8583 primary, we still need a VTT entry for the vtable, but it
8584 should point to the ctor vtable for the base it is a
8585 primary for within the sub-hierarchy of RTTI_BINFO.
8587 There are three possible cases:
8589 1) We are in the same place.
8590 2) We are a primary base within a lost primary virtual base of
8591 RTTI_BINFO.
8592 3) We are primary to something not a base of RTTI_BINFO. */
8594 tree b;
8597 /* First, look through the bases we are primary to for RTTI_BINFO
8598 or a virtual base. */
8601 {
8606 }
8607 /* If we run out of primary links, keep looking down our
8608 inheritance chain; we might be an indirect primary. */
8612 found:
8614 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8615 base B and it is a base of RTTI_BINFO, this is case 2. In
8616 either case, we share our vtable with LAST, i.e. the
8617 derived-most base within B of which we are a primary. */
8620 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8621 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8622 binfo_ctor_vtable after everything's been set up. */
8625 /* Otherwise, this is case 3 and we get our own. */
8626 }
8633 {
8634 tree index;
8637 /* Add the initializer for this vtable. */
8641 /* Figure out the position to which the VPTR should point. */
8647 }
8650 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8651 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8652 straighten this out. */
8655 /* Throw away any unneeded intializers. */
8657 else
8658 /* For an ordinary vtable, set BINFO_VTABLE. */
8660 }
8664 /* Construct the initializer for BINFO's virtual function table. BINFO
8665 is part of the hierarchy dominated by T. If we're building a
8666 construction vtable, the ORIG_BINFO is the binfo we should use to
8667 find the actual function pointers to put in the vtable - but they
8668 can be overridden on the path to most-derived in the graph that
8669 ORIG_BINFO belongs. Otherwise,
8670 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8671 BINFO that should be indicated by the RTTI information in the
8672 vtable; it will be a base class of T, rather than T itself, if we
8673 are building a construction vtable.
8675 The value returned is a TREE_LIST suitable for wrapping in a
8676 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8677 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8678 number of non-function entries in the vtable.
8680 It might seem that this function should never be called with a
8681 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8682 base is always subsumed by a derived class vtable. However, when
8683 we are building construction vtables, we do build vtables for
8684 primary bases; we need these while the primary base is being
8685 constructed. */
8687 static void
8689 tree orig_binfo,
8690 tree t,
8691 tree rtti_binfo,
8694 {
8695 tree v;
8696 vtbl_init_data vid;
8698 tree vbinfo;
8702 /* Initialize VID. */
8710 /* The first vbase or vcall offset is at index -3 in the vtable. */
8713 /* Add entries to the vtable for RTTI. */
8716 /* Create an array for keeping track of the functions we've
8717 processed. When we see multiple functions with the same
8718 signature, we share the vcall offsets. */
8720 /* Add the vcall and vbase offset entries. */
8723 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8724 build_vbase_offset_vtbl_entries. */
8729 /* If the target requires padding between data entries, add that now. */
8731 {
8736 /* Move data entries into their new positions and add padding
8737 after the new positions. Iterate backwards so we don't
8738 overwrite entries that we would need to process later. */
8741 ix--)
8742 {
8750 {
8754 null_pointer_node);
8755 }
8756 }
8757 }
8762 /* The initializers for virtual functions were built up in reverse
8763 order. Straighten them out and add them to the running list in one
8764 step. */
8773 /* Go through all the ordinary virtual functions, building up
8774 initializers. */
8776 {
8777 tree delta;
8778 tree vcall_index;
8785 {
8789 {
8792 }
8794 }
8796 /* If the only definition of this function signature along our
8797 primary base chain is from a lost primary, this vtable slot will
8798 never be used, so just zero it out. This is important to avoid
8799 requiring extra thunks which cannot be generated with the function.
8801 We first check this in update_vtable_entry_for_fn, so we handle
8802 restored primary bases properly; we also need to do it here so we
8803 zero out unused slots in ctor vtables, rather than filling them
8804 with erroneous values (though harmless, apart from relocation
8805 costs). */
8810 {
8811 /* Pull the offset for `this', and the function to call, out of
8812 the list. */
8819 /* You can't call an abstract virtual function; it's abstract.
8820 So, we replace these functions with __pure_virtual. */
8822 {
8825 {
8827 abort_fndecl_addr
8831 }
8832 }
8833 /* Likewise for deleted virtuals. */
8835 {
8840 NULL_TREE);
8844 }
8845 else
8846 {
8848 {
8852 }
8853 /* Take the address of the function, considering it to be of an
8854 appropriate generic type. */
8858 }
8859 }
8861 /* And add it to the chain of initializers. */
8863 {
8868 else
8870 {
8876 }
8877 }
8878 else
8880 }
8881 }
8883 /* Adds to vid->inits the initializers for the vbase and vcall
8884 offsets in BINFO, which is in the hierarchy dominated by T. */
8886 static void
8888 {
8889 tree b;
8891 /* If this is a derived class, we must first create entries
8892 corresponding to the primary base class. */
8897 /* Add the vbase entries for this base. */
8899 /* Add the vcall entries for this base. */
8901 }
8903 /* Returns the initializers for the vbase offset entries in the vtable
8904 for BINFO (which is part of the class hierarchy dominated by T), in
8905 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8906 where the next vbase offset will go. */
8908 static void
8910 {
8911 tree vbase;
8912 tree t;
8913 tree non_primary_binfo;
8915 /* If there are no virtual baseclasses, then there is nothing to
8916 do. */
8922 /* We might be a primary base class. Go up the inheritance hierarchy
8923 until we find the most derived class of which we are a primary base:
8924 it is the offset of that which we need to use. */
8927 {
8928 tree b;
8930 /* If we have reached a virtual base, then it must be a primary
8931 base (possibly multi-level) of vid->binfo, or we wouldn't
8932 have called build_vcall_and_vbase_vtbl_entries for it. But it
8933 might be a lost primary, so just skip down to vid->binfo. */
8935 {
8938 }
8944 }
8946 /* Go through the virtual bases, adding the offsets. */
8948 vbase;
8950 {
8951 tree b;
8952 tree delta;
8957 /* Find the instance of this virtual base in the complete
8958 object. */
8961 /* If we've already got an offset for this virtual base, we
8962 don't need another one. */
8967 /* Figure out where we can find this vbase offset. */
8976 /* The vbase offset had better be the same. */
8979 /* The next vbase will come at a more negative offset. */
8983 /* The initializer is the delta from BINFO to this virtual base.
8984 The vbase offsets go in reverse inheritance-graph order, and
8985 we are walking in inheritance graph order so these end up in
8986 the right order. */
8993 }
8994 }
8996 /* Adds the initializers for the vcall offset entries in the vtable
8997 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8998 to VID->INITS. */
9000 static void
9002 {
9003 /* We only need these entries if this base is a virtual base. We
9004 compute the indices -- but do not add to the vtable -- when
9005 building the main vtable for a class. */
9008 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9009 correspond to VID->DERIVED), we are building a primary
9010 construction virtual table. Since this is a primary
9011 virtual table, we do not need the vcall offsets for
9012 BINFO. */
9014 {
9015 /* We need a vcall offset for each of the virtual functions in this
9016 vtable. For example:
9018 class A { virtual void f (); };
9019 class B1 : virtual public A { virtual void f (); };
9020 class B2 : virtual public A { virtual void f (); };
9021 class C: public B1, public B2 { virtual void f (); };
9023 A C object has a primary base of B1, which has a primary base of A. A
9024 C also has a secondary base of B2, which no longer has a primary base
9025 of A. So the B2-in-C construction vtable needs a secondary vtable for
9026 A, which will adjust the A* to a B2* to call f. We have no way of
9027 knowing what (or even whether) this offset will be when we define B2,
9028 so we store this "vcall offset" in the A sub-vtable and look it up in
9029 a "virtual thunk" for B2::f.
9031 We need entries for all the functions in our primary vtable and
9032 in our non-virtual bases' secondary vtables. */
9034 /* If we are just computing the vcall indices -- but do not need
9035 the actual entries -- not that. */
9038 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9040 }
9041 }
9043 /* Build vcall offsets, starting with those for BINFO. */
9045 static void
9047 {
9049 tree primary_binfo;
9050 tree base_binfo;
9052 /* Don't walk into virtual bases -- except, of course, for the
9053 virtual base for which we are building vcall offsets. Any
9054 primary virtual base will have already had its offsets generated
9055 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9059 /* If BINFO has a primary base, process it first. */
9064 /* Add BINFO itself to the list. */
9067 /* Scan the non-primary bases of BINFO. */
9071 }
9073 /* Called from build_vcall_offset_vtbl_entries_r. */
9075 static void
9077 {
9078 /* Make entries for the rest of the virtuals. */
9080 {
9081 tree orig_fn;
9083 /* The ABI requires that the methods be processed in declaration
9084 order. G++ 3.2 used the order in the vtable. */
9086 orig_fn;
9090 }
9091 else
9092 {
9093 tree derived_virtuals;
9094 tree base_virtuals;
9095 tree orig_virtuals;
9096 /* If BINFO is a primary base, the most derived class which has
9097 BINFO as a primary base; otherwise, just BINFO. */
9098 tree non_primary_binfo;
9100 /* We might be a primary base class. Go up the inheritance hierarchy
9101 until we find the most derived class of which we are a primary base:
9102 it is the BINFO_VIRTUALS there that we need to consider. */
9105 {
9106 tree b;
9108 /* If we have reached a virtual base, then it must be vid->vbase,
9109 because we ignore other virtual bases in
9110 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9111 base (possibly multi-level) of vid->binfo, or we wouldn't
9112 have called build_vcall_and_vbase_vtbl_entries for it. But it
9113 might be a lost primary, so just skip down to vid->binfo. */
9115 {
9119 }
9125 }
9128 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9129 where rtti_binfo is the most derived type. */
9130 non_primary_binfo
9136 base_virtuals;
9140 {
9141 tree orig_fn;
9143 /* Find the declaration that originally caused this function to
9144 be present in BINFO_TYPE (binfo). */
9147 /* When processing BINFO, we only want to generate vcall slots for
9148 function slots introduced in BINFO. So don't try to generate
9149 one if the function isn't even defined in BINFO. */
9154 }
9155 }
9156 }
9158 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9160 static void
9162 {
9164 tree vcall_offset;
9165 tree derived_entry;
9167 /* If there is already an entry for a function with the same
9168 signature as FN, then we do not need a second vcall offset.
9169 Check the list of functions already present in the derived
9170 class vtable. */
9172 {
9174 /* We only use one vcall offset for virtual destructors,
9175 even though there are two virtual table entries. */
9179 }
9181 /* If we are building these vcall offsets as part of building
9182 the vtable for the most derived class, remember the vcall
9183 offset. */
9185 {
9188 }
9190 /* The next vcall offset will be found at a more negative
9191 offset. */
9195 /* Keep track of this function. */
9199 {
9200 tree base;
9201 tree fn;
9203 /* Find the overriding function. */
9207 else
9208 {
9211 /* The vbase we're working on is a primary base of
9212 vid->binfo. But it might be a lost primary, so its
9213 BINFO_OFFSET might be wrong, so we just use the
9214 BINFO_OFFSET from vid->binfo. */
9220 vcall_offset);
9221 }
9222 /* Add the initializer to the vtable. */
9224 }
9225 }
9227 /* Return vtbl initializers for the RTTI entries corresponding to the
9228 BINFO's vtable. The RTTI entries should indicate the object given
9229 by VID->rtti_binfo. */
9231 static void
9233 {
9234 tree b;
9235 tree t;
9236 tree offset;
9237 tree decl;
9238 tree init;
9242 /* To find the complete object, we will first convert to our most
9243 primary base, and then add the offset in the vtbl to that value. */
9247 {
9248 tree primary_base;
9254 }
9258 /* The second entry is the address of the typeinfo object. */
9261 else
9264 /* Convert the declaration to a type that can be stored in the
9265 vtable. */
9269 /* Add the offset-to-top entry. It comes earlier in the vtable than
9270 the typeinfo entry. Convert the offset to look like a
9271 function pointer, so that we can put it in the vtable. */
9274 }
9276 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9277 accessibility. */
9279 bool
9281 {
9284 }
9286 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9288 bool
9290 {
9294 }
9296 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9297 class between them, if any. */
9299 tree
9301 {
9313 {
9316 }
9320 }