| blob | 7362c732646bf6af5f16fcad13d8fcb185de673e |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2016 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. */
68 struct vtbl_init_data
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. */
97 };
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. */
150 /* Used by find_flexarrays and related. */
200 tree *);
210 splay_tree_key k2);
219 /* Variables shared between class.c and call.c. */
229 /* Return a COND_EXPR that executes TRUE_STMT if this execution of the
230 'structor is in charge of 'structing virtual bases, or FALSE_STMT
231 otherwise. */
233 tree
235 {
245 }
247 /* Convert to or from a base subobject. EXPR is an expression of type
248 `A' or `A*', an expression of type `B' or `B*' is returned. To
249 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
250 the B base instance within A. To convert base A to derived B, CODE
251 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
252 In this latter case, A must not be a morally virtual base of B.
253 NONNULL is true if EXPR is known to be non-NULL (this is only
254 needed when EXPR is of pointer type). CV qualifiers are preserved
255 from EXPR. */
257 tree
259 tree expr,
260 tree binfo,
262 tsubst_flags_t complain)
263 {
266 tree probe;
267 tree offset;
268 tree target_type;
270 tree ptr_target_type;
281 {
287 }
295 {
296 /* This can happen when adjust_result_of_qualified_name_lookup can't
297 find a unique base binfo in a call to a member function. We
298 couldn't give the diagnostic then since we might have been calling
299 a static member function, so we do it now. */
301 {
305 }
307 }
314 /* Nothing to do. */
318 {
320 {
322 {
325 "pointer to derived class %qT because the base is "
327 else
331 }
332 else
333 {
339 else
343 }
344 }
346 }
349 {
351 /* This must happen before the call to save_expr. */
353 }
354 else
360 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
361 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
362 expression returned matches the input. */
363 target_type = cp_build_qualified_type
367 /* Do we need to look in the vtable for the real offset? */
370 /* Don't bother with the calculations inside sizeof; they'll ICE if the
371 source type is incomplete and the pointer value doesn't matter. In a
372 template (even in instantiate_non_dependent_expr), we don't have vtables
373 set up properly yet, and the value doesn't matter there either; we're
374 just interested in the result of overload resolution. */
377 {
380 }
382 /* If we're in an NSDMI, we don't have the full constructor context yet
383 that we need for converting to a virtual base, so just build a stub
384 CONVERT_EXPR and expand it later in bot_replace. */
387 {
391 }
393 /* Do we need to check for a null pointer? */
395 {
396 /* If we know the conversion will not actually change the value
397 of EXPR, then we can avoid testing the expression for NULL.
398 We have to avoid generating a COMPONENT_REF for a base class
399 field, because other parts of the compiler know that such
400 expressions are always non-NULL. */
404 }
406 /* Protect against multiple evaluation if necessary. */
410 /* Now that we've saved expr, build the real null test. */
412 {
416 /* This is a compiler generated comparison, don't emit
417 e.g. -Wnonnull-compare warning for it. */
419 }
421 /* If this is a simple base reference, express it as a COMPONENT_REF. */
423 /* We don't build base fields for empty bases, and they aren't very
424 interesting to the optimizers anyway. */
426 {
435 }
438 {
439 /* Going via virtual base V_BINFO. We need the static offset
440 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
441 V_BINFO. That offset is an entry in D_BINFO's vtable. */
442 tree v_offset;
445 {
446 /* In a base member initializer, we cannot rely on the
447 vtable being set up. We have to indirect via the
448 vtt_parm. */
449 tree t;
455 }
456 else
457 {
460 {
465 }
467 complain),
469 }
477 v_offset);
489 /* Negative fixed_type_p means this is a constructor or destructor;
490 virtual base layout is fixed in in-charge [cd]tors, but not in
491 base [cd]tors. */
492 offset = build_if_in_charge
494 v_offset);
495 else
497 }
505 {
510 }
511 else
514 indout:
516 {
520 }
522 out:
528 }
530 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
531 Perform a derived-to-base conversion by recursively building up a
532 sequence of COMPONENT_REFs to the appropriate base fields. */
534 static tree
536 {
539 tree field;
542 {
543 tree temp;
547 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
548 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
549 an lvalue in the front end; only _DECLs and _REFs are lvalues
550 in the back end. */
556 }
558 /* Recurse. */
563 /* Is this the base field created by build_base_field? */
567 /* If we're looking for a field in the most-derived class,
568 also check the field offset; we can have two base fields
569 of the same type if one is an indirect virtual base and one
570 is a direct non-virtual base. */
574 {
575 /* We don't use build_class_member_access_expr here, as that
576 has unnecessary checks, and more importantly results in
577 recursive calls to dfs_walk_once. */
583 /* Mark the expression const or volatile, as appropriate.
584 Even though we've dealt with the type above, we still have
585 to mark the expression itself. */
592 }
594 /* Didn't find the base field?!? */
596 }
598 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
599 type is a class type or a pointer to a class type. In the former
600 case, TYPE is also a class type; in the latter it is another
601 pointer type. If CHECK_ACCESS is true, an error message is emitted
602 if TYPE is inaccessible. If OBJECT has pointer type, the value is
603 assumed to be non-NULL. */
605 tree
607 tsubst_flags_t complain)
608 {
609 tree binfo;
610 tree object_type;
613 {
616 }
617 else
626 }
628 /* EXPR is an expression with unqualified class type. BASE is a base
629 binfo of that class type. Returns EXPR, converted to the BASE
630 type. This function assumes that EXPR is the most derived class;
631 therefore virtual bases can be found at their static offsets. */
633 tree
635 {
636 tree expr_type;
640 {
641 /* If this is a non-empty base, use a COMPONENT_REF. */
645 /* We use fold_build2 and fold_convert below to simplify the trees
646 provided to the optimizers. It is not safe to call these functions
647 when processing a template because they do not handle C++-specific
648 trees. */
656 }
659 }
661 \f
662 tree
664 {
668 /* Can happen in case of duplicate base types (c++/59082). */
672 /* First, convert to the requested type. */
677 /* Second, the requested type may not be the owner of its own vptr.
678 If not, convert to the base class that owns it. We cannot use
679 convert_to_base here, because VCONTEXT may appear more than once
680 in the inheritance hierarchy of TYPE, and thus direct conversion
681 between the types may be ambiguous. Following the path back up
682 one step at a time via primary bases avoids the problem. */
686 {
689 }
692 }
694 /* Given an object INSTANCE, return an expression which yields the
695 vtable element corresponding to INDEX. There are many special
696 cases for INSTANCE which we take care of here, mainly to avoid
697 creating extra tree nodes when we don't have to. */
699 static tree
701 {
702 tree aref;
705 /* Try to figure out what a reference refers to, and
706 access its virtual function table directly. */
714 {
719 }
728 }
730 tree
732 {
736 }
738 /* Given a stable object pointer INSTANCE_PTR, return an expression which
739 yields a function pointer corresponding to vtable element INDEX. */
741 tree
743 {
744 tree aref;
747 tf_warning_or_error),
748 idx);
750 /* When using function descriptors, the address of the
751 vtable entry is treated as a function pointer. */
756 /* Remember this as a method reference, for later devirtualization. */
760 }
762 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
763 for the given TYPE. */
765 static tree
767 {
769 }
771 /* DECL is an entity associated with TYPE, like a virtual table or an
772 implicitly generated constructor. Determine whether or not DECL
773 should have external or internal linkage at the object file
774 level. This routine does not deal with COMDAT linkage and other
775 similar complexities; it simply sets TREE_PUBLIC if it possible for
776 entities in other translation units to contain copies of DECL, in
777 the abstract. */
779 void
781 {
784 }
786 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
787 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
788 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
790 static tree
792 {
793 tree decl;
796 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
797 now to avoid confusion in mangle_decl. */
808 /* The vtable has not been defined -- yet. */
812 /* Mark the VAR_DECL node representing the vtable itself as a
813 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
814 is rather important that such things be ignored because any
815 effort to actually generate DWARF for them will run into
816 trouble when/if we encounter code like:
818 #pragma interface
819 struct S { virtual void member (); };
821 because the artificial declaration of the vtable itself (as
822 manufactured by the g++ front end) will say that the vtable is
823 a static member of `S' but only *after* the debug output for
824 the definition of `S' has already been output. This causes
825 grief because the DWARF entry for the definition of the vtable
826 will try to refer back to an earlier *declaration* of the
827 vtable as a static member of `S' and there won't be one. We
828 might be able to arrange to have the "vtable static member"
829 attached to the member list for `S' before the debug info for
830 `S' get written (which would solve the problem) but that would
831 require more intrusive changes to the g++ front end. */
835 }
837 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
838 or even complete. If this does not exist, create it. If COMPLETE is
839 nonzero, then complete the definition of it -- that will render it
840 impossible to actually build the vtable, but is useful to get at those
841 which are known to exist in the runtime. */
843 tree
845 {
846 tree decl;
855 {
858 }
861 }
863 /* Build the primary virtual function table for TYPE. If BINFO is
864 non-NULL, build the vtable starting with the initial approximation
865 that it is the same as the one which is the head of the association
866 list. Returns a nonzero value if a new vtable is actually
867 created. */
869 static int
871 {
872 tree decl;
873 tree virtuals;
878 {
880 /* We have already created a vtable for this base, so there's
881 no need to do it again. */
888 }
889 else
890 {
893 }
896 {
899 }
901 /* Initialize the association list for this type, based
902 on our first approximation. */
907 }
909 /* Give BINFO a new virtual function table which is initialized
910 with a skeleton-copy of its original initialization. The only
911 entry that changes is the `delta' entry, so we can really
912 share a lot of structure.
914 FOR_TYPE is the most derived type which caused this table to
915 be needed.
917 Returns nonzero if we haven't met BINFO before.
919 The order in which vtables are built (by calling this function) for
920 an object must remain the same, otherwise a binary incompatibility
921 can result. */
923 static int
925 {
927 /* We already created a vtable for this base. There's no need to
928 do it again. */
931 /* Remember that we've created a vtable for this BINFO, so that we
932 don't try to do so again. */
935 /* Make fresh virtual list, so we can smash it later. */
938 /* Secondary vtables are laid out as part of the same structure as
939 the primary vtable. */
942 }
944 /* Create a new vtable for BINFO which is the hierarchy dominated by
945 T. Return nonzero if we actually created a new vtable. */
947 static int
949 {
951 /* In this case, it is *type*'s vtable we are modifying. We start
952 with the approximation that its vtable is that of the
953 immediate base class. */
955 else
956 /* This is our very own copy of `basetype' to play with. Later,
957 we will fill in all the virtual functions that override the
958 virtual functions in these base classes which are not defined
959 by the current type. */
961 }
963 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
964 (which is in the hierarchy dominated by T) list FNDECL as its
965 BV_FN. DELTA is the required constant adjustment from the `this'
966 pointer where the vtable entry appears to the `this' required when
967 the function is actually called. */
969 static void
971 tree binfo,
972 tree fndecl,
973 tree delta,
975 {
976 tree v;
982 {
983 /* We need a new vtable for BINFO. */
985 {
986 /* If we really did make a new vtable, we also made a copy
987 of the BINFO_VIRTUALS list. Now, we have to find the
988 corresponding entry in that list. */
993 }
998 }
999 }
1001 \f
1002 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
1003 the USING_DECL naming METHOD. Returns true if the method could be
1004 added to the method vec. */
1006 bool
1008 {
1010 tree overload;
1016 tree current_fns;
1017 tree fns;
1030 {
1031 /* Make a new method vector. We start with 8 entries. We must
1032 allocate at least two (for constructors and destructors), and
1033 we're going to end up with an assignment operator at some
1034 point as well. */
1036 /* Create slots for constructors and destructors. */
1040 }
1042 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1045 /* Constructors and destructors go in special slots. */
1049 {
1053 {
1059 type);
1060 }
1061 }
1062 else
1063 {
1064 tree m;
1067 /* See if we already have an entry with this name. */
1071 {
1074 {
1079 }
1083 {
1086 }
1091 }
1092 }
1095 /* Check to see if we've already got this method. */
1097 {
1099 tree fn_type;
1100 tree method_type;
1101 tree parms1;
1102 tree parms2;
1107 /* [over.load] Member function declarations with the
1108 same name and the same parameter types cannot be
1109 overloaded if any of them is a static member
1110 function declaration.
1112 [over.load] Member function declarations with the same name and
1113 the same parameter-type-list as well as member function template
1114 declarations with the same name, the same parameter-type-list, and
1115 the same template parameter lists cannot be overloaded if any of
1116 them, but not all, have a ref-qualifier.
1118 [namespace.udecl] When a using-declaration brings names
1119 from a base class into a derived class scope, member
1120 functions in the derived class override and/or hide member
1121 functions with the same name and parameter types in a base
1122 class (rather than conflicting). */
1128 /* Compare the quals on the 'this' parm. Don't compare
1129 the whole types, as used functions are treated as
1130 coming from the using class in overload resolution. */
1133 /* Either both or neither need to be ref-qualified for
1134 differing quals to allow overloading. */
1141 /* For templates, the return type and template parameters
1142 must be identical. */
1160 {
1161 /* For function versions, their parms and types match
1162 but they are not duplicates. Record function versions
1163 as and when they are found. extern "C" functions are
1164 not treated as versions. */
1170 {
1171 /* Mark functions as versions if necessary. Modify the mangled
1172 decl name if necessary. */
1174 {
1178 }
1180 {
1184 }
1187 }
1189 {
1191 {
1198 }
1199 /* Otherwise defer to the other function. */
1201 }
1203 {
1205 /* Defer to the local function. */
1207 }
1208 else
1209 {
1212 }
1214 /* We don't call duplicate_decls here to merge the
1215 declarations because that will confuse things if the
1216 methods have inline definitions. In particular, we
1217 will crash while processing the definitions. */
1219 }
1220 }
1222 /* A class should never have more than one destructor. */
1226 /* Add the new binding. */
1228 {
1231 }
1232 else
1241 {
1244 /* We only expect to add few methods in the COMPLETE_P case, so
1245 just make room for one more method in that case. */
1248 else
1254 else
1256 }
1257 else
1258 /* Replace the current slot. */
1261 }
1263 /* Subroutines of finish_struct. */
1265 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1266 legit, otherwise return 0. */
1268 static int
1270 {
1271 tree elem;
1280 {
1282 {
1286 else
1289 }
1290 else
1291 {
1292 /* They're changing the access to the same thing they changed
1293 it to before. That's OK. */
1294 ;
1295 }
1296 }
1297 else
1298 {
1300 tf_warning_or_error);
1303 }
1305 }
1307 /* Process the USING_DECL, which is a member of T. */
1309 static void
1311 {
1314 tree access
1319 tree old_value;
1324 tf_warning_or_error);
1326 {
1332 else
1334 }
1342 ;
1344 {
1346 /* It's OK to use functions from a base when there are functions with
1348 else
1349 {
1354 }
1355 }
1357 {
1361 }
1363 /* Make type T see field decl FDECL with access ACCESS. */
1366 {
1369 }
1370 else
1372 }
1373 \f
1374 /* Data structure for find_abi_tags_r, below. */
1376 struct abi_tag_data
1377 {
1381 };
1383 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1384 in the context of P. TAG can be either an identifier (the DECL_NAME of
1385 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1387 static void
1389 {
1391 {
1393 {
1394 /* We're collecting tags from template arguments or from
1395 the type of a variable or function return type. */
1398 /* Don't inherit this tag multiple times. */
1402 {
1403 /* Tags inherited from type template arguments are only used
1404 to avoid warnings. */
1407 }
1408 /* For functions and variables we want to warn, too. */
1409 }
1411 /* Otherwise we're diagnosing missing tags. */
1413 {
1418 }
1420 {
1424 }
1426 {
1431 }
1432 else
1433 {
1437 {
1441 }
1442 }
1443 }
1444 }
1446 /* Find all the ABI tags in the attribute list ATTR and either call
1447 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1449 static void
1451 {
1458 {
1463 else
1465 }
1466 }
1468 /* Find all the ABI tags on T and its enclosing scopes and either call
1469 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1471 static void
1473 {
1475 {
1476 tree attr;
1478 {
1481 }
1482 else
1483 {
1486 }
1488 }
1489 }
1491 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1492 types with ABI tags, add the corresponding identifiers to the VEC in
1493 *DATA and set IDENTIFIER_MARKED. */
1495 static tree
1497 {
1501 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1502 anyway, but let's make sure of it. */
1510 }
1512 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1513 IDENTIFIER_MARKED on its ABI tags. */
1515 static tree
1517 {
1521 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1522 anyway, but let's make sure of it. */
1530 }
1532 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1533 scopes. */
1535 static void
1537 {
1540 {
1543 {
1544 /* Template arguments are part of the signature. */
1547 {
1550 }
1551 }
1553 /* A function's parameter types are part of the signature, so
1554 we don't need to inherit any tags that are also in them. */
1559 }
1560 }
1562 /* Check that T has all the ABI tags that subobject SUBOB has, or
1563 warn if not. If T is a (variable or function) declaration, also
1564 return any missing tags, and add them to T if JUST_CHECKING is false. */
1566 static tree
1568 {
1576 /* No need to worry about things local to this TU. */
1592 {
1595 }
1596 else
1597 {
1601 else
1605 }
1610 }
1612 /* Check that DECL has all the ABI tags that are used in parts of its type
1613 that are not reflected in its mangled name. */
1615 void
1617 {
1624 }
1626 /* Return any ABI tags that are used in parts of the type of DECL
1627 that are not reflected in its mangled name. This function is only
1628 used in backward-compatible mangling for ABI <11. */
1630 tree
1632 {
1636 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so
1637 that we can use this function for setting need_abi_warning
1638 regardless of the current flag_abi_version. */
1641 else
1643 }
1645 void
1647 {
1657 {
1660 {
1664 }
1665 }
1667 // If we found some tags on our template arguments, add them to our
1668 // abi_tag attribute.
1670 {
1674 else
1678 }
1681 }
1683 /* Return true, iff class T has a non-virtual destructor that is
1684 accessible from outside the class heirarchy (i.e. is public, or
1685 there's a suitable friend. */
1687 static bool
1689 {
1692 /* An implicitly declared destructor is always public. And,
1693 if it were virtual, we would have created it by now. */
1708 }
1710 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1711 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1712 properties of the bases. */
1714 static void
1718 {
1722 tree base_binfo;
1723 tree binfo;
1733 {
1742 /* If any base class is non-literal, so is the derived class. */
1746 /* If the base class doesn't have copy constructors or
1747 assignment operators that take const references, then the
1748 derived class cannot have such a member automatically
1749 generated. */
1758 /* A virtual base does not effect nearly emptiness. */
1759 ;
1761 {
1763 /* And if there is more than one nearly empty base, then the
1764 derived class is not nearly empty either. */
1766 else
1767 /* Remember we've seen one. */
1769 }
1771 /* If the base class is not empty or nearly empty, then this
1772 class cannot be nearly empty. */
1775 /* A lot of properties from the bases also apply to the derived
1776 class. */
1793 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1796 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1802 /* A standard-layout class is a class that:
1803 ...
1804 * has no non-standard-layout base classes, */
1807 {
1808 tree basefield;
1809 /* ...has no base classes of the same type as the first non-static
1810 data member... */
1812 && (same_type_ignoring_top_level_qualifiers_p
1815 else
1816 /* ...either has no non-static data members in the most-derived
1817 class and at most one base class with non-static data
1818 members, or has no base classes with non-static data
1819 members */
1823 {
1826 else
1829 }
1830 }
1832 /* Don't bother collecting tm attributes if transactional memory
1833 support is not enabled. */
1835 {
1839 }
1842 }
1844 /* If one of the base classes had TM attributes, and the current class
1845 doesn't define its own, then the current class inherits one. */
1847 {
1850 }
1851 }
1853 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1854 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1855 that have had a nearly-empty virtual primary base stolen by some
1856 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1857 T. */
1859 static void
1861 {
1865 tree base_binfo;
1867 /* Determine the primary bases of our bases. */
1870 {
1873 /* See if we're the non-virtual primary of our inheritance
1874 chain. */
1876 {
1883 /* We are the primary binfo. */
1885 }
1886 /* Determine if we have a virtual primary base, and mark it so.
1887 */
1889 {
1893 /* Someone already claimed this base. */
1895 else
1896 {
1897 tree delta;
1902 /* A virtual binfo might have been copied from within
1903 another hierarchy. As we're about to use it as a
1904 primary base, make sure the offsets match. */
1912 }
1913 }
1914 }
1916 /* First look for a dynamic direct non-virtual base. */
1918 {
1922 {
1925 }
1926 }
1928 /* A "nearly-empty" virtual base class can be the primary base
1929 class, if no non-virtual polymorphic base can be found. Look for
1930 a nearly-empty virtual dynamic base that is not already a primary
1931 base of something in the hierarchy. If there is no such base,
1932 just pick the first nearly-empty virtual base. */
1938 {
1940 {
1941 /* Found one that is not primary. */
1944 }
1946 /* Remember the first candidate. */
1948 }
1950 found:
1951 /* If we've got a primary base, use it. */
1953 {
1958 /* We are stealing a primary base. */
1962 {
1963 tree delta;
1966 /* A virtual binfo might have been copied from within
1967 another hierarchy. As we're about to use it as a primary
1968 base, make sure the offsets match. */
1973 }
1980 }
1981 }
1983 /* Update the variant types of T. */
1985 void
1987 {
1988 tree variants;
1994 variants;
1996 {
1997 /* These fields are in the _TYPE part of the node, not in
1998 the TYPE_LANG_SPECIFIC component, so they are not shared. */
2008 /* Copy whatever these are holding today. */
2011 }
2012 }
2014 /* KLASS is a class that we're applying may_alias to after the body is
2015 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
2016 canonical type(s) will be implicitly updated. */
2018 static void
2020 {
2021 tree t;
2027 }
2029 /* Early variant fixups: we apply attributes at the beginning of the class
2030 definition, and we need to fix up any variants that have already been
2031 made via elaborated-type-specifier so that check_qualified_type works. */
2033 void
2035 {
2036 tree variants;
2050 variants;
2052 {
2053 /* These are the two fields that check_qualified_type looks at and
2054 are affected by attributes. */
2059 else
2064 }
2065 }
2066 \f
2067 /* Set memoizing fields and bits of T (and its variants) for later
2068 use. */
2070 static void
2072 {
2073 /* Fix up variants (if any). */
2077 /* For a class w/o baseclasses, 'finish_struct' has set
2078 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2079 Similarly for a class whose base classes do not have vtables.
2080 When neither of these is true, we might have removed abstract
2081 virtuals (by providing a definition), added some (by declaring
2082 new ones), or redeclared ones from a base class. We need to
2083 recalculate what's really an abstract virtual at this point (by
2084 looking in the vtables). */
2087 /* If this type has a copy constructor or a destructor, force its
2088 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2089 nonzero. This will cause it to be passed by invisible reference
2090 and prevent it from being returned in a register. */
2093 {
2094 tree variants;
2097 {
2100 }
2101 }
2102 }
2104 /* Issue warnings about T having private constructors, but no friends,
2105 and so forth.
2107 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2108 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2109 non-private static member functions. */
2111 static void
2113 {
2116 tree fn;
2119 /* If the class has friends, those entities might create and
2120 access instances, so we should not warn. */
2123 /* We will have warned when the template was declared; there's
2124 no need to warn on every instantiation. */
2126 /* There's no reason to even consider warning about this
2127 class. */
2130 /* We only issue one warning, if more than one applies, because
2131 otherwise, on code like:
2133 class A {
2134 // Oops - forgot `public:'
2135 A();
2136 A(const A&);
2137 ~A();
2138 };
2140 we warn several times about essentially the same problem. */
2142 /* Check to see if all (non-constructor, non-destructor) member
2143 functions are private. (Since there are no friends or
2144 non-private statics, we can't ever call any of the private member
2145 functions.) */
2147 /* We're not interested in compiler-generated methods; they don't
2148 provide any way to call private members. */
2150 {
2152 {
2154 /* A non-private static member function is just like a
2155 friend; it can create and invoke private member
2156 functions, and be accessed without a class
2157 instance. */
2161 /* Keep searching for a static member function. */
2162 }
2165 }
2168 {
2169 /* There are no non-private methods, and there's at least one
2170 private member function that isn't a constructor or
2171 destructor. (If all the private members are
2172 constructors/destructors we want to use the code below that
2173 issues error messages specifically referring to
2174 constructors/destructors.) */
2180 {
2183 }
2185 {
2189 }
2190 }
2192 /* Even if some of the member functions are non-private, the class
2193 won't be useful for much if all the constructors or destructors
2194 are private: such an object can never be created or destroyed. */
2197 {
2200 t);
2202 }
2204 /* Warn about classes that have private constructors and no friends. */
2206 /* Implicitly generated constructors are always public. */
2209 {
2212 /* If a non-template class does not define a copy
2213 constructor, one is defined for it, enabling it to avoid
2214 this warning. For a template class, this does not
2215 happen, and so we would normally get a warning on:
2217 template <class T> class C { private: C(); };
2219 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2220 complete non-template or fully instantiated classes have this
2221 flag set. */
2224 else
2226 {
2228 /* Ideally, we wouldn't count copy constructors (or, in
2229 fact, any constructor that takes an argument of the
2230 class type as a parameter) because such things cannot
2231 be used to construct an instance of the class unless
2232 you already have one. But, for now at least, we're
2233 more generous. */
2235 {
2238 }
2239 }
2242 {
2245 t);
2247 }
2248 }
2249 }
2252 gt_pointer_operator new_value;
2256 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2258 static int
2260 {
2273 }
2275 /* This routine compares two fields like method_name_cmp but using the
2276 pointer operator in resort_field_decl_data. */
2278 static int
2280 {
2289 {
2296 }
2298 }
2300 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2302 void
2305 gt_pointer_operator new_value,
2307 {
2311 tree fn;
2313 /* The type conversion ops have to live at the front of the vec, so we
2314 can't sort them. */
2322 {
2326 resort_method_name_cmp);
2327 }
2328 }
2330 /* Warn about duplicate methods in fn_fields.
2332 Sort methods that are not special (i.e., constructors, destructors,
2333 and type conversion operators) so that we can find them faster in
2334 search. */
2336 static void
2338 {
2339 tree fn_fields;
2349 /* Clear DECL_IN_AGGR_P for all functions. */
2354 /* Issue warnings about private constructors and such. If there are
2355 no methods, then some public defaults are generated. */
2358 /* The type conversion ops have to live at the front of the vec, so we
2359 can't sort them. */
2368 }
2370 /* Make BINFO's vtable have N entries, including RTTI entries,
2371 vbase and vcall offsets, etc. Set its type and call the back end
2372 to lay it out. */
2374 static void
2376 {
2377 tree atype;
2378 tree vtable;
2383 /* We may have to grow the vtable. */
2386 {
2390 }
2391 }
2393 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2394 have the same signature. */
2396 int
2398 {
2399 /* One destructor overrides another if they are the same kind of
2400 destructor. */
2404 /* But a non-destructor never overrides a destructor, nor vice
2405 versa, nor do different kinds of destructors override
2406 one-another. For example, a complete object destructor does not
2407 override a deleting destructor. */
2416 {
2424 }
2426 }
2428 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2429 subobject. */
2431 static bool
2433 {
2434 tree probe;
2437 {
2441 /* If we meet a virtual base, we can't follow the inheritance
2442 any more. See if the complete type of DERIVED contains
2443 such a virtual base. */
2446 }
2448 }
2451 /* The function for which we are trying to find a final overrider. */
2452 tree fn;
2453 /* The base class in which the function was declared. */
2454 tree declaring_base;
2455 /* The candidate overriders. */
2456 tree candidates;
2457 /* Path to most derived. */
2459 };
2461 /* Add the overrider along the current path to FFOD->CANDIDATES.
2462 Returns true if an overrider was found; false otherwise. */
2464 static bool
2468 {
2469 tree method;
2471 /* If BINFO is not the most derived type, try a more derived class.
2472 A definition there will overrider a definition here. */
2474 {
2475 depth--;
2479 }
2483 {
2486 /* Remove any candidates overridden by this new function. */
2488 {
2489 /* If *CANDIDATE overrides METHOD, then METHOD
2490 cannot override anything else on the list. */
2493 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2496 else
2498 }
2500 /* Add the new function. */
2503 }
2506 }
2508 /* Called from find_final_overrider via dfs_walk. */
2510 static tree
2512 {
2520 }
2522 static tree
2524 {
2529 }
2531 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2532 FN and whose TREE_VALUE is the binfo for the base where the
2533 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2534 DERIVED) is the base object in which FN is declared. */
2536 static tree
2538 {
2539 find_final_overrider_data ffod;
2541 /* Getting this right is a little tricky. This is valid:
2543 struct S { virtual void f (); };
2544 struct T { virtual void f (); };
2545 struct U : public S, public T { };
2547 even though calling `f' in `U' is ambiguous. But,
2549 struct R { virtual void f(); };
2550 struct S : virtual public R { virtual void f (); };
2551 struct T : virtual public R { virtual void f (); };
2552 struct U : public S, public T { };
2554 is not -- there's no way to decide whether to put `S::f' or
2555 `T::f' in the vtable for `R'.
2557 The solution is to look at all paths to BINFO. If we find
2558 different overriders along any two, then there is a problem. */
2562 /* Determine the depth of the hierarchy. */
2573 /* If there was no winner, issue an error message. */
2578 }
2580 /* Return the index of the vcall offset for FN when TYPE is used as a
2581 virtual base. */
2583 static tree
2585 {
2587 tree_pair_p p;
2595 /* There should always be an appropriate index. */
2597 }
2599 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2600 dominated by T. FN is the old function; VIRTUALS points to the
2601 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2602 of that entry in the list. */
2604 static void
2607 {
2608 tree b;
2609 tree overrider;
2610 tree delta;
2611 tree virtual_base;
2612 tree first_defn;
2618 /* Find the nearest primary base (possibly binfo itself) which defines
2619 this function; this is the class the caller will convert to when
2620 calling FN through BINFO. */
2622 {
2627 /* The nearest definition is from a lost primary. */
2630 }
2633 /* Find the final overrider. */
2636 {
2639 }
2642 /* Check for adjusting covariant return types. */
2650 /* If the overrider is invalid, don't even try. */
2652 {
2653 /* If FN is a covariant thunk, we must figure out the adjustment
2654 to the final base FN was converting to. As OVERRIDER_TARGET might
2655 also be converting to the return type of FN, we have to
2656 combine the two conversions here. */
2663 {
2667 }
2668 else
2672 /* Find the equivalent binfo within the return type of the
2673 overriding function. We will want the vbase offset from
2674 there. */
2676 over_return);
2679 {
2680 /* There was no existing virtual thunk (which takes
2681 precedence). So find the binfo of the base function's
2682 return type within the overriding function's return type.
2683 Fortunately we know the covariancy is valid (it
2684 has already been checked), so we can just iterate along
2685 the binfos, which have been chained in inheritance graph
2686 order. Of course it is lame that we have to repeat the
2687 search here anyway -- we should really be caching pieces
2688 of the vtable and avoiding this repeated work. */
2691 /* Find the base binfo within the overriding function's
2692 return type. We will always find a thunk_binfo, except
2693 when the covariancy is invalid (which we will have
2694 already diagnosed). */
2697 thunk_binfo;
2703 /* See if virtual inheritance is involved. */
2705 virtual_offset;
2712 {
2716 {
2717 /* We convert via virtual base. Adjust the fixed
2718 offset to be from there. */
2719 offset =
2723 }
2725 /* There was an existing fixed offset, this must be
2726 from the base just converted to, and the base the
2727 FN was thunking to. */
2729 else
2731 }
2732 }
2735 /* Replace the overriding function with a covariant thunk. We
2736 will emit the overriding function in its own slot as
2737 well. */
2740 }
2741 else
2745 /* If we need a covariant thunk, then we may need to adjust first_defn.
2746 The ABI specifies that the thunks emitted with a function are
2747 determined by which bases the function overrides, so we need to be
2748 sure that we're using a thunk for some overridden base; even if we
2749 know that the necessary this adjustment is zero, there may not be an
2750 appropriate zero-this-adjusment thunk for us to use since thunks for
2751 overriding virtual bases always use the vcall offset.
2753 Furthermore, just choosing any base that overrides this function isn't
2754 quite right, as this slot won't be used for calls through a type that
2755 puts a covariant thunk here. Calling the function through such a type
2756 will use a different slot, and that slot is the one that determines
2757 the thunk emitted for that base.
2759 So, keep looking until we find the base that we're really overriding
2760 in this slot: the nearest primary base that doesn't use a covariant
2761 thunk in this slot. */
2763 {
2765 /* We already know that the overrider needs a covariant thunk. */
2768 {
2775 }
2777 }
2779 /* Assume that we will produce a thunk that convert all the way to
2780 the final overrider, and not to an intermediate virtual base. */
2783 /* See if we can convert to an intermediate virtual base first, and then
2784 use the vcall offset located there to finish the conversion. */
2786 {
2787 /* If we find the final overrider, then we can stop
2788 walking. */
2793 /* If we find a virtual base, and we haven't yet found the
2794 overrider, then there is a virtual base between the
2795 declaring base (first_defn) and the final overrider. */
2797 {
2800 }
2801 }
2803 /* Compute the constant adjustment to the `this' pointer. The
2804 `this' pointer, when this function is called, will point at BINFO
2805 (or one of its primary bases, which are at the same offset). */
2807 /* The `this' pointer needs to be adjusted from the declaration to
2808 the nearest virtual base. */
2813 /* If the nearest definition is in a lost primary, we don't need an
2814 entry in our vtable. Except possibly in a constructor vtable,
2815 if we happen to get our primary back. In that case, the offset
2816 will be zero, as it will be a primary base. */
2818 else
2819 /* The `this' pointer needs to be adjusted from pointing to
2820 BINFO to pointing at the base where the final overrider
2821 appears. */
2832 else
2836 }
2838 /* Called from modify_all_vtables via dfs_walk. */
2840 static tree
2842 {
2844 tree virtuals;
2845 tree old_virtuals;
2849 /* A base without a vtable needs no modification, and its bases
2850 are uninteresting. */
2855 /* Don't do the primary vtable, if it's new. */
2859 /* There's no need to modify the vtable for a non-virtual primary
2860 base; we're not going to use that vtable anyhow. We do still
2861 need to do this for virtual primary bases, as they could become
2862 non-primary in a construction vtable. */
2867 /* Now, go through each of the virtual functions in the virtual
2868 function table for BINFO. Find the final overrider, and update
2869 the BINFO_VIRTUALS list appropriately. */
2872 virtuals;
2876 binfo,
2881 }
2883 /* Update all of the primary and secondary vtables for T. Create new
2884 vtables as required, and initialize their RTTI information. Each
2885 of the functions in VIRTUALS is declared in T and may override a
2886 virtual function from a base class; find and modify the appropriate
2887 entries to point to the overriding functions. Returns a list, in
2888 declaration order, of the virtual functions that are declared in T,
2889 but do not appear in the primary base class vtable, and which
2890 should therefore be appended to the end of the vtable for T. */
2892 static tree
2894 {
2898 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2902 /* Update all of the vtables. */
2905 /* Add virtual functions not already in our primary vtable. These
2906 will be both those introduced by this class, and those overridden
2907 from secondary bases. It does not include virtuals merely
2908 inherited from secondary bases. */
2910 {
2915 {
2916 /* We don't need to adjust the `this' pointer when
2917 calling this function. */
2921 /* This is a function not already in our vtable. Keep it. */
2923 }
2924 else
2925 /* We've already got an entry for this function. Skip it. */
2927 }
2930 }
2932 /* Get the base virtual function declarations in T that have the
2933 indicated NAME. */
2935 static void
2937 {
2938 tree methods;
2942 /* Find virtual functions in T with the indicated NAME. */
2947 methods;
2949 {
2954 {
2957 }
2958 }
2964 {
2967 }
2968 }
2970 /* If this declaration supersedes the declaration of
2971 a method declared virtual in the base class, then
2972 mark this field as being virtual as well. */
2974 void
2976 {
2979 /* In [temp.mem] we have:
2981 A specialization of a member function template does not
2982 override a virtual function from a base class. */
2989 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2990 the error_mark_node so that we know it is an overriding
2991 function. */
2992 {
2999 }
3002 {
3008 }
3013 }
3015 /* Warn about hidden virtual functions that are not overridden in t.
3016 We know that constructors and destructors don't apply. */
3018 static void
3020 {
3022 tree fns;
3025 /* We go through each separately named virtual function. */
3029 {
3030 tree fn;
3031 tree name;
3032 tree fndecl;
3033 tree base_binfo;
3034 tree binfo;
3037 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
3038 have the same name. Figure out what name that is. */
3040 /* There are no possibly hidden functions yet. */
3042 /* Iterate through all of the base classes looking for possibly
3043 hidden functions. */
3046 {
3049 }
3051 /* If there are no functions to hide, continue. */
3055 /* Remove any overridden functions. */
3057 {
3061 {
3062 /* If the method from the base class has the same
3063 signature as the method from the derived class, it
3064 has been overridden. */
3069 }
3070 }
3072 /* Now give a warning for all base functions without overriders,
3073 as they are hidden. */
3075 tree base_fndecl;
3078 {
3079 /* Here we know it is a hider, and no overrider exists. */
3081 OPT_Woverloaded_virtual,
3085 }
3086 }
3087 }
3089 /* Recursive helper for finish_struct_anon. */
3091 static void
3093 {
3097 {
3098 /* We're generally only interested in entities the user
3099 declared, but we also find nested classes by noticing
3100 the TYPE_DECL that we create implicitly. You're
3101 allowed to put one anonymous union inside another,
3102 though, so we explicitly tolerate that. We use
3103 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that
3104 we also allow unnamed types used for defining fields. */
3111 {
3112 /* We already complained about static data members in
3113 finish_static_data_member_decl. */
3115 {
3118 "%q#D invalid; an anonymous union can "
3120 else
3122 "%q#D invalid; an anonymous struct can "
3124 }
3126 }
3129 {
3131 {
3135 else
3138 }
3140 {
3144 else
3147 }
3148 }
3153 /* Recurse into the anonymous aggregates to handle correctly
3154 access control (c++/24926):
3156 class A {
3157 union {
3158 union {
3159 int i;
3160 };
3161 };
3162 };
3164 int j=A().i; */
3168 }
3169 }
3171 /* Check for things that are invalid. There are probably plenty of other
3172 things we should check for also. */
3174 static void
3176 {
3178 {
3187 }
3188 }
3190 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3191 will be used later during class template instantiation.
3192 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3193 a non-static member data (FIELD_DECL), a member function
3194 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3195 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3196 When FRIEND_P is nonzero, T is either a friend class
3197 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3198 (FUNCTION_DECL, TEMPLATE_DECL). */
3200 void
3202 {
3203 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3208 }
3210 /* This function is called from declare_virt_assop_and_dtor via
3211 dfs_walk_all.
3213 DATA is a type that direcly or indirectly inherits the base
3214 represented by BINFO. If BINFO contains a virtual assignment [copy
3215 assignment or move assigment] operator or a virtual constructor,
3216 declare that function in DATA if it hasn't been already declared. */
3218 static tree
3220 {
3228 /* A base without a vtable needs no modification, and its bases
3229 are uninteresting. */
3233 /* If this is a primary base, then we have already looked at the
3234 virtual functions of its vtable. */
3238 {
3242 {
3247 }
3251 }
3254 }
3256 /* If the class type T has a direct or indirect base that contains a
3257 virtual assignment operator or a virtual destructor, declare that
3258 function in T if it hasn't been already declared. */
3260 static void
3262 {
3270 dfs_declare_virt_assop_and_dtor,
3272 }
3274 /* Declare the inheriting constructor for class T inherited from base
3275 constructor CTOR with the parameter array PARMS of size NPARMS. */
3277 static void
3279 {
3280 /* We don't declare an inheriting ctor that would be a default,
3281 copy or move ctor for derived or base. */
3286 {
3290 }
3299 {
3302 }
3303 }
3305 /* Declare all the inheriting constructors for class T inherited from base
3306 constructor CTOR. */
3308 static void
3310 {
3316 {
3320 }
3323 {
3327 }
3328 }
3330 /* Create default constructors, assignment operators, and so forth for
3331 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3332 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3333 the class cannot have a default constructor, copy constructor
3334 taking a const reference argument, or an assignment operator taking
3335 a const reference, respectively. */
3337 static void
3341 {
3349 /* Destructor. */
3351 {
3352 /* In general, we create destructors lazily. */
3357 /* But if this is a Java class, any non-trivial destructor is
3358 invalid, even if compiler-generated. Therefore, if the
3359 destructor is non-trivial we create it now. */
3361 }
3363 /* [class.ctor]
3365 If there is no user-declared constructor for a class, a default
3366 constructor is implicitly declared. */
3368 {
3373 /* Don't force the declaration to get a hard answer; if the
3374 definition would have made the class non-literal, it will still be
3375 non-literal because of the base or member in question, and that
3376 gives a better diagnostic. */
3378 }
3380 /* [class.ctor]
3382 If a class definition does not explicitly declare a copy
3383 constructor, one is declared implicitly. */
3385 {
3391 }
3393 /* If there is no assignment operator, one will be created if and
3394 when it is needed. For now, just record whether or not the type
3395 of the parameter to the assignment operator will be a const or
3396 non-const reference. */
3398 {
3404 }
3406 /* We can't be lazy about declaring functions that might override
3407 a virtual function from a base class. */
3411 {
3415 {
3416 /* declare, then remove the decl */
3425 }
3426 else
3428 }
3429 }
3431 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3432 count the number of fields in TYPE, including anonymous union
3433 members. */
3435 static int
3437 {
3438 tree x;
3441 {
3444 else
3446 }
3448 }
3450 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3451 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3452 elts, starting at offset IDX. */
3454 static int
3456 {
3457 tree x;
3459 {
3462 else
3464 }
3466 }
3468 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3469 starting at offset IDX. */
3471 static int
3475 {
3476 tree values;
3480 }
3482 /* FIELD is a bit-field. We are finishing the processing for its
3483 enclosing type. Issue any appropriate messages and set appropriate
3484 flags. Returns false if an error has been diagnosed. */
3486 static bool
3488 {
3490 tree w;
3492 /* Extract the declared width of the bitfield, which has been
3493 temporarily stashed in DECL_INITIAL. */
3496 /* Remove the bit-field width indicator so that the rest of the
3497 compiler does not treat that value as an initializer. */
3500 /* Detect invalid bit-field type. */
3502 {
3505 }
3506 else
3507 {
3509 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3512 /* detect invalid field size. */
3518 {
3521 }
3523 {
3526 }
3528 {
3531 }
3546 }
3549 {
3553 }
3554 else
3555 {
3556 /* Non-bit-fields are aligned for their type. */
3560 }
3561 }
3563 /* FIELD is a non bit-field. We are finishing the processing for its
3564 enclosing type T. Issue any appropriate messages and set appropriate
3565 flags. */
3567 static bool
3569 tree t,
3572 {
3576 /* In C++98 an anonymous union cannot contain any fields which would change
3577 the settings of CANT_HAVE_CONST_CTOR and friends. */
3579 ;
3580 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3581 structs. So, we recurse through their fields here. */
3583 {
3588 cant_have_const_ctor,
3589 no_const_asn_ref);
3590 }
3591 /* Check members with class type for constructors, destructors,
3592 etc. */
3594 {
3595 /* Never let anything with uninheritable virtuals
3596 make it through without complaint. */
3600 {
3605 field);
3610 field);
3612 {
3616 }
3617 }
3618 else
3619 {
3632 }
3641 }
3646 /* `build_class_init_list' does not recognize
3647 non-FIELD_DECLs. */
3651 }
3653 /* Check the data members (both static and non-static), class-scoped
3654 typedefs, etc., appearing in the declaration of T. Issue
3655 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3656 declaration order) of access declarations; each TREE_VALUE in this
3657 list is a USING_DECL.
3659 In addition, set the following flags:
3661 EMPTY_P
3662 The class is empty, i.e., contains no non-static data members.
3664 CANT_HAVE_CONST_CTOR_P
3665 This class cannot have an implicitly generated copy constructor
3666 taking a const reference.
3668 CANT_HAVE_CONST_ASN_REF
3669 This class cannot have an implicitly generated assignment
3670 operator taking a const reference.
3672 All of these flags should be initialized before calling this
3673 function.
3675 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3676 fields can be added by adding to this chain. */
3678 static void
3682 {
3690 /* Assume there are no access declarations. */
3692 /* Assume this class has no pointer members. */
3694 /* Assume none of the members of this class have default
3695 initializations. */
3699 {
3707 {
3708 /* Save the access declarations for our caller. */
3711 }
3717 /* If we've gotten this far, it's a data member, possibly static,
3718 or an enumerator. */
3722 /* When this goes into scope, it will be a non-local reference. */
3727 {
3728 /* [class.union] (C++98)
3730 If a union contains a static data member, or a member of
3731 reference type, the program is ill-formed.
3733 In C++11 this limitation doesn't exist anymore. */
3735 {
3739 }
3741 {
3745 }
3746 }
3748 /* Perform error checking that did not get done in
3749 grokdeclarator. */
3751 {
3755 }
3757 {
3761 }
3769 /* Now it can only be a FIELD_DECL. */
3774 /* If at least one non-static data member is non-literal, the whole
3775 class becomes non-literal. Per Core/1453, volatile non-static
3776 data members and base classes are also not allowed.
3777 Note: if the type is incomplete we will complain later on. */
3782 /* A standard-layout class is a class that:
3783 ...
3784 has the same access control (Clause 11) for all non-static data members,
3785 ... */
3792 /* If this is of reference type, check if it needs an init. */
3794 {
3800 {
3801 /* ARM $12.6.2: [A member initializer list] (or, for an
3802 aggregate, initialization by a brace-enclosed list) is the
3803 only way to initialize nonstatic const and reference
3804 members. */
3807 }
3808 }
3813 {
3815 {
3816 warning_at
3819 x);
3821 }
3825 }
3828 /* We don't treat zero-width bitfields as making a class
3829 non-empty. */
3830 ;
3831 else
3832 {
3833 /* The class is non-empty. */
3835 /* The class is not even nearly empty. */
3837 /* If one of the data members contains an empty class,
3838 so does T. */
3842 }
3844 /* This is used by -Weffc++ (see below). Warn only for pointers
3845 to members which might hold dynamic memory. So do not warn
3846 for pointers to functions or pointers to members. */
3852 {
3857 }
3863 {
3865 {
3869 }
3871 {
3875 }
3876 }
3879 /* DR 148 now allows pointers to members (which are POD themselves),
3880 to be allowed in POD structs. */
3889 /* We set DECL_C_BIT_FIELD in grokbitfield.
3890 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3893 cant_have_const_ctor_p,
3894 no_const_asn_ref_p))
3895 {
3900 }
3902 /* Now that we've removed bit-field widths from DECL_INITIAL,
3903 anything left in DECL_INITIAL is an NSDMI that makes the class
3904 non-aggregate in C++11. */
3908 /* If any field is const, the structure type is pseudo-const. */
3910 {
3915 {
3916 /* ARM $12.6.2: [A member initializer list] (or, for an
3917 aggregate, initialization by a brace-enclosed list) is the
3918 only way to initialize nonstatic const and reference
3919 members. */
3922 }
3923 }
3924 /* A field that is pseudo-const makes the structure likewise. */
3926 {
3931 }
3933 /* Core issue 80: A nonstatic data member is required to have a
3934 different name from the class iff the class has a
3935 user-declared constructor. */
3940 }
3942 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3943 it should also define a copy constructor and an assignment operator to
3944 implement the correct copy semantic (deep vs shallow, etc.). As it is
3945 not feasible to check whether the constructors do allocate dynamic memory
3946 and store it within members, we approximate the warning like this:
3948 -- Warn only if there are members which are pointers
3949 -- Warn only if there is a non-trivial constructor (otherwise,
3950 there cannot be memory allocated).
3951 -- Warn only if there is a non-trivial destructor. We assume that the
3952 user at least implemented the cleanup correctly, and a destructor
3953 is needed to free dynamic memory.
3955 This seems enough for practical purposes. */
3957 && has_pointers
3961 {
3965 {
3970 }
3974 }
3976 /* Non-static data member initializers make the default constructor
3977 non-trivial. */
3979 {
3982 }
3984 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3988 /* Check anonymous struct/anonymous union fields. */
3991 /* We've built up the list of access declarations in reverse order.
3992 Fix that now. */
3994 }
3996 /* If TYPE is an empty class type, records its OFFSET in the table of
3997 OFFSETS. */
3999 static int
4001 {
4002 splay_tree_node n;
4007 /* Record the location of this empty object in OFFSETS. */
4015 type,
4019 }
4021 /* Returns nonzero if TYPE is an empty class type and there is
4022 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
4024 static int
4026 {
4027 splay_tree_node n;
4028 tree t;
4033 /* Record the location of this empty object in OFFSETS. */
4043 }
4045 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
4046 F for every subobject, passing it the type, offset, and table of
4047 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
4048 be traversed.
4050 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
4051 than MAX_OFFSET will not be walked.
4053 If F returns a nonzero value, the traversal ceases, and that value
4054 is returned. Otherwise, returns zero. */
4056 static int
4058 subobject_offset_fn f,
4059 tree offset,
4060 splay_tree offsets,
4061 tree max_offset,
4063 {
4067 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
4068 stop. */
4076 {
4079 }
4082 {
4083 tree field;
4084 tree binfo;
4087 /* Avoid recursing into objects that are not interesting. */
4091 /* Record the location of TYPE. */
4096 /* Iterate through the direct base classes of TYPE. */
4100 {
4101 tree binfo_offset;
4106 tree orig_binfo;
4107 /* We cannot rely on BINFO_OFFSET being set for the base
4108 class yet, but the offsets for direct non-virtual
4109 bases can be calculated by going back to the TYPE. */
4112 offset,
4116 f,
4117 binfo_offset,
4118 offsets,
4119 max_offset,
4123 }
4126 {
4130 /* Iterate through the virtual base classes of TYPE. In G++
4131 3.2, we included virtual bases in the direct base class
4132 loop above, which results in incorrect results; the
4133 correct offsets for virtual bases are only known when
4134 working with the most derived type. */
4138 {
4140 f,
4142 offset,
4144 offsets,
4145 max_offset,
4149 }
4150 else
4151 {
4152 /* We still have to walk the primary base, if it is
4153 virtual. (If it is non-virtual, then it was walked
4154 above.) */
4160 {
4161 r = (walk_subobject_offsets
4166 }
4167 }
4168 }
4170 /* Iterate through the fields of TYPE. */
4175 {
4176 tree field_offset;
4181 f,
4183 offset,
4184 field_offset),
4185 offsets,
4186 max_offset,
4190 }
4191 }
4193 {
4196 tree index;
4198 /* Avoid recursing into objects that are not interesting. */
4201 || !domain
4205 /* Step through each of the elements in the array. */
4209 {
4211 f,
4212 offset,
4213 offsets,
4214 max_offset,
4220 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4221 there's no point in iterating through the remaining
4222 elements of the array. */
4225 }
4226 }
4229 }
4231 /* Record all of the empty subobjects of TYPE (either a type or a
4232 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4233 is being placed at OFFSET; otherwise, it is a base class that is
4234 being placed at OFFSET. */
4236 static void
4238 tree offset,
4239 splay_tree offsets,
4241 {
4242 tree max_offset;
4243 /* If recording subobjects for a non-static data member or a
4244 non-empty base class , we do not need to record offsets beyond
4245 the size of the biggest empty class. Additional data members
4246 will go at the end of the class. Additional base classes will go
4247 either at offset zero (if empty, in which case they cannot
4248 overlap with offsets past the size of the biggest empty class) or
4249 at the end of the class.
4251 However, if we are placing an empty base class, then we must record
4252 all offsets, as either the empty class is at offset zero (where
4253 other empty classes might later be placed) or at the end of the
4254 class (where other objects might then be placed, so other empty
4255 subobjects might later overlap). */
4259 else
4263 }
4265 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4266 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4267 virtual bases of TYPE are examined. */
4269 static int
4271 tree offset,
4272 splay_tree offsets,
4274 {
4275 splay_tree_node max_node;
4277 /* Get the node in OFFSETS that indicates the maximum offset where
4278 an empty subobject is located. */
4280 /* If there aren't any empty subobjects, then there's no point in
4281 performing this check. */
4287 vbases_p);
4288 }
4290 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4291 non-static data member of the type indicated by RLI. BINFO is the
4292 binfo corresponding to the base subobject, OFFSETS maps offsets to
4293 types already located at those offsets. This function determines
4294 the position of the DECL. */
4296 static void
4298 tree decl,
4299 tree binfo,
4300 splay_tree offsets)
4301 {
4304 tree type;
4307 {
4308 /* For the purposes of determining layout conflicts, we want to
4309 use the class type of BINFO; TREE_TYPE (DECL) will be the
4310 CLASSTYPE_AS_BASE version, which does not contain entries for
4311 zero-sized bases. */
4314 }
4315 else
4316 {
4319 }
4321 /* Try to place the field. It may take more than one try if we have
4322 a hard time placing the field without putting two objects of the
4323 same type at the same address. */
4325 {
4328 /* Place this field. */
4332 /* We have to check to see whether or not there is already
4333 something of the same type at the offset we're about to use.
4334 For example, consider:
4336 struct S {};
4337 struct T : public S { int i; };
4338 struct U : public S, public T {};
4340 Here, we put S at offset zero in U. Then, we can't put T at
4341 offset zero -- its S component would be at the same address
4342 as the S we already allocated. So, we have to skip ahead.
4343 Since all data members, including those whose type is an
4344 empty class, have nonzero size, any overlap can happen only
4345 with a direct or indirect base-class -- it can't happen with
4346 a data member. */
4347 /* In a union, overlap is permitted; all members are placed at
4348 offset zero. */
4353 {
4354 /* Strip off the size allocated to this field. That puts us
4355 at the first place we could have put the field with
4356 proper alignment. */
4359 /* Bump up by the alignment required for the type. */
4360 rli->bitpos
4366 }
4369 {
4370 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4371 the offset wasn't aligned like a pointer when we started to
4372 layout this field, that affects its position. */
4375 {
4378 "alignment of %qD increased in -fabi-version=9 "
4380 else
4383 }
4385 }
4386 else
4387 /* There was no conflict. We're done laying out this field. */
4389 }
4391 /* Now that we know where it will be placed, update its
4392 BINFO_OFFSET. */
4394 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4395 this point because their BINFO_OFFSET is copied from another
4396 hierarchy. Therefore, we may not need to add the entire
4397 OFFSET. */
4403 }
4405 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4407 static int
4409 tree offset,
4411 {
4413 }
4415 /* Layout the empty base BINFO. EOC indicates the byte currently just
4416 past the end of the class, and should be correctly aligned for a
4417 class of the type indicated by BINFO; OFFSETS gives the offsets of
4418 the empty bases allocated so far. T is the most derived
4419 type. Return nonzero iff we added it at the end. */
4421 static bool
4424 {
4425 tree alignment;
4429 /* This routine should only be used for empty classes. */
4434 propagate_binfo_offsets
4438 /* This is an empty base class. We first try to put it at offset
4439 zero. */
4442 offsets,
4444 {
4445 /* That didn't work. Now, we move forward from the next
4446 available spot in the class. */
4450 {
4453 offsets,
4455 /* We finally found a spot where there's no overlap. */
4458 /* There's overlap here, too. Bump along to the next spot. */
4460 }
4461 }
4464 {
4469 }
4472 }
4474 /* Layout the base given by BINFO in the class indicated by RLI.
4475 *BASE_ALIGN is a running maximum of the alignments of
4476 any base class. OFFSETS gives the location of empty base
4477 subobjects. T is the most derived type. Return nonzero if the new
4478 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4479 *NEXT_FIELD, unless BINFO is for an empty base class.
4481 Returns the location at which the next field should be inserted. */
4486 {
4491 /* This error is now reported in xref_tag, thus giving better
4492 location information. */
4495 /* Place the base class. */
4497 {
4498 tree decl;
4500 /* The containing class is non-empty because it has a non-empty
4501 base class. */
4504 /* Create the FIELD_DECL. */
4511 {
4519 /* Try to place the field. It may take more than one try if we
4520 have a hard time placing the field without putting two
4521 objects of the same type at the same address. */
4523 /* Add the new FIELD_DECL to the list of fields for T. */
4527 }
4528 }
4529 else
4530 {
4531 tree eoc;
4534 /* On some platforms (ARM), even empty classes will not be
4535 byte-aligned. */
4540 /* A nearly-empty class "has no proper base class that is empty,
4541 not morally virtual, and at an offset other than zero." */
4543 {
4546 /* The check above (used in G++ 3.2) is insufficient because
4547 an empty class placed at offset zero might itself have an
4548 empty base at a nonzero offset. */
4550 empty_base_at_nonzero_offset_p,
4551 size_zero_node,
4556 }
4558 /* We do not create a FIELD_DECL for empty base classes because
4559 it might overlap some other field. We want to be able to
4560 create CONSTRUCTORs for the class by iterating over the
4561 FIELD_DECLs, and the back end does not handle overlapping
4562 FIELD_DECLs. */
4564 /* An empty virtual base causes a class to be non-empty
4565 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4566 here because that was already done when the virtual table
4567 pointer was created. */
4568 }
4570 /* Record the offsets of BINFO and its base subobjects. */
4573 offsets,
4577 }
4579 /* Layout all of the non-virtual base classes. Record empty
4580 subobjects in OFFSETS. T is the most derived type. Return nonzero
4581 if the type cannot be nearly empty. The fields created
4582 corresponding to the base classes will be inserted at
4583 *NEXT_FIELD. */
4585 static void
4588 {
4589 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4590 subobjects. */
4595 /* The primary base class is always allocated first. */
4600 /* Now allocate the rest of the bases. */
4602 {
4603 tree base_binfo;
4607 /* The primary base was already allocated above, so we don't
4608 need to allocate it again here. */
4612 /* Virtual bases are added at the end (a primary virtual base
4613 will have already been added). */
4619 }
4620 }
4622 /* Go through the TYPE_METHODS of T issuing any appropriate
4623 diagnostics, figuring out which methods override which other
4624 methods, and so forth. */
4626 static void
4628 {
4629 tree x;
4632 {
4636 /* The name of the field is the original field name
4637 Save this in auxiliary field for later overloading. */
4639 {
4643 }
4644 /* All user-provided destructors are non-trivial.
4645 Constructors and assignment ops are handled in
4646 grok_special_member_properties. */
4652 "%<transaction_safe_dynamic%> may only be specified for "
4654 }
4655 }
4657 /* FN is a constructor or destructor. Clone the declaration to create
4658 a specialized in-charge or not-in-charge version, as indicated by
4659 NAME. */
4661 static tree
4663 {
4664 tree parms;
4665 tree clone;
4667 /* Copy the function. */
4669 /* Reset the function name. */
4671 /* Remember where this function came from. */
4673 /* Make it easy to find the CLONE given the FN. */
4677 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4679 {
4686 }
4687 else
4688 {
4689 // Clone constraints.
4693 }
4698 /* There's no pending inline data for this function. */
4702 /* The base-class destructor is not virtual. */
4704 {
4708 }
4710 /* If there was an in-charge parameter, drop it from the function
4711 type. */
4713 {
4714 tree basetype;
4715 tree parmtypes;
4716 tree exceptions;
4721 /* Skip the `this' parameter. */
4723 /* Skip the in-charge parameter. */
4725 /* And the VTT parm, in a complete [cd]tor. */
4729 /* If this is subobject constructor or destructor, add the vtt
4730 parameter. */
4734 parmtypes);
4737 exceptions);
4741 }
4743 /* Copy the function parameters. */
4745 /* Remove the in-charge parameter. */
4747 {
4751 }
4752 /* And the VTT parm, in a complete [cd]tor. */
4754 {
4757 else
4758 {
4762 }
4763 }
4766 {
4769 }
4771 /* Create the RTL for this function. */
4776 }
4778 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4779 not invoke this function directly.
4781 For a non-thunk function, returns the address of the slot for storing
4782 the function it is a clone of. Otherwise returns NULL_TREE.
4784 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4785 cloned_function is unset. This is to support the separate
4786 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4787 on a template makes sense, but not the former. */
4789 tree *
4791 {
4799 {
4800 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4803 else
4804 #endif
4806 }
4811 else
4813 }
4815 /* Produce declarations for all appropriate clones of FN. If
4816 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4817 CLASTYPE_METHOD_VEC as well. */
4819 void
4821 {
4822 tree clone;
4824 /* Avoid inappropriate cloning. */
4830 {
4831 /* For each constructor, we need two variants: an in-charge version
4832 and a not-in-charge version. */
4839 }
4840 else
4841 {
4844 /* For each destructor, we need three variants: an in-charge
4845 version, a not-in-charge version, and an in-charge deleting
4846 version. We clone the deleting version first because that
4847 means it will go second on the TYPE_METHODS list -- and that
4848 corresponds to the correct layout order in the virtual
4849 function table.
4851 For a non-virtual destructor, we do not build a deleting
4852 destructor. */
4854 {
4858 }
4865 }
4867 /* Note that this is an abstract function that is never emitted. */
4869 }
4871 /* DECL is an in charge constructor, which is being defined. This will
4872 have had an in class declaration, from whence clones were
4873 declared. An out-of-class definition can specify additional default
4874 arguments. As it is the clones that are involved in overload
4875 resolution, we must propagate the information from the DECL to its
4876 clones. */
4878 void
4880 {
4881 tree clone;
4885 {
4892 /* Skip the 'this' parameter. */
4908 {
4913 {
4914 /* A default parameter has been added. Adjust the
4915 clone's parameters. */
4919 tree type;
4924 {
4927 clone_parms);
4929 }
4932 clone_parms);
4941 }
4942 }
4944 }
4945 }
4947 /* For each of the constructors and destructors in T, create an
4948 in-charge and not-in-charge variant. */
4950 static void
4952 {
4953 tree fns;
4955 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4956 out now. */
4964 }
4966 /* Deduce noexcept for a destructor DTOR. */
4968 void
4970 {
4972 {
4975 }
4976 }
4978 /* For each destructor in T, deduce noexcept:
4980 12.4/3: A declaration of a destructor that does not have an
4981 exception-specification is implicitly considered to have the
4982 same exception-specification as an implicit declaration (15.4). */
4984 static void
4986 {
4987 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4988 out now. */
4994 }
4996 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4997 of TYPE for virtual functions which FNDECL overrides. Return a
4998 mask of the tm attributes found therein. */
5000 static int
5002 {
5004 tree base_binfo;
5008 {
5016 {
5020 else
5023 }
5024 else
5026 }
5029 }
5031 /* Subroutine of set_method_tm_attributes. Handle the checks and
5032 inheritance for one virtual method FNDECL. */
5034 static void
5036 {
5037 tree tm_attr;
5042 /* If FNDECL doesn't actually override anything (i.e. T is the
5043 class that first declares FNDECL virtual), then we're done. */
5050 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
5051 tm_pure must match exactly, otherwise no weakening of
5052 tm_safe > tm_callable > nothing. */
5053 /* ??? The tm_pure attribute didn't make the transition to the
5054 multivendor language spec. */
5056 {
5058 {
5061 }
5062 }
5063 /* If the overridden function is tm_pure, then FNDECL must be. */
5066 /* Look for base class combinations that cannot be satisfied. */
5068 {
5074 }
5075 /* If FNDECL did not declare an attribute, then inherit the most
5076 restrictive one. */
5078 {
5080 }
5081 /* Otherwise validate that we're not weaker than a function
5082 that is being overridden. */
5083 else
5084 {
5088 }
5091 err_override:
5095 }
5097 /* For each of the methods in T, propagate a class-level tm attribute. */
5099 static void
5101 {
5104 /* Don't bother collecting tm attributes if transactional memory
5105 support is not enabled. */
5109 /* Process virtual methods first, as they inherit directly from the
5110 base virtual function and also require validation of new attributes. */
5112 {
5113 tree vchain;
5116 {
5121 }
5122 }
5124 /* If the class doesn't have an attribute, nothing more to do. */
5129 /* Any method that does not yet have a tm attribute inherits
5130 the one from the class. */
5132 {
5135 }
5136 }
5138 /* Returns true if FN is a default constructor. */
5140 bool
5142 {
5145 }
5147 /* Returns true iff class T has a user-defined constructor that can be called
5148 with more than zero arguments. */
5150 bool
5152 {
5153 tree fns;
5159 {
5166 }
5169 }
5171 /* Returns the defaulted constructor if T has one. Otherwise, returns
5172 NULL_TREE. */
5174 tree
5176 {
5181 {
5187 }
5190 }
5192 /* Returns true iff FN is a user-provided function, i.e. user-declared
5193 and not defaulted at its first declaration. */
5195 bool
5197 {
5200 else
5204 }
5206 /* Returns true iff class T has a user-provided constructor. */
5208 bool
5210 {
5211 tree fns;
5219 /* This can happen in error cases; avoid crashing. */
5228 }
5230 /* Returns true iff class T has a user-provided or explicit constructor. */
5232 bool
5234 {
5235 tree fns;
5243 /* This can happen in error cases; avoid crashing. */
5248 {
5252 }
5255 }
5257 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5258 declared or explicitly defaulted in the class body) default
5259 constructor. */
5261 bool
5263 {
5264 tree fns;
5272 {
5278 }
5281 }
5283 /* TYPE is being used as a virtual base, and has a non-trivial move
5284 assignment. Return true if this is due to there being a user-provided
5285 move assignment in TYPE or one of its subobjects; if there isn't, then
5286 multiple move assignment can't cause any harm. */
5288 bool
5290 {
5291 /* Does the type itself have a user-provided move assignment operator? */
5295 {
5299 }
5301 /* Do any of its bases? */
5303 tree base_binfo;
5308 /* Or non-static data members? */
5310 {
5315 }
5317 /* Seems not. */
5319 }
5321 /* If default-initialization leaves part of TYPE uninitialized, returns
5322 a DECL for the field or TYPE itself (DR 253). */
5324 tree
5326 {
5337 {
5341 }
5346 {
5350 }
5353 }
5355 /* Returns true iff for class T, a trivial synthesized default constructor
5356 would be constexpr. */
5358 bool
5360 {
5361 /* A defaulted trivial default constructor is constexpr
5362 if there is nothing to initialize. */
5365 }
5367 /* Returns true iff class T has a constexpr default constructor. */
5369 bool
5371 {
5372 tree fns;
5375 {
5376 /* The caller should have stripped an enclosing array. */
5379 }
5381 {
5384 /* Non-trivial, we need to check subobject constructors. */
5386 }
5389 }
5391 /* Returns true iff class T has a constexpr default constructor or has an
5392 implicitly declared default constructor that we can't tell if it's constexpr
5393 without forcing a lazy declaration (which might cause undesired
5394 instantiations). */
5396 bool
5398 {
5401 /* Assume it's constexpr. */
5404 }
5406 /* Returns true iff class TYPE has a virtual destructor. */
5408 bool
5410 {
5411 tree dtor;
5419 }
5421 /* Returns true iff class T has a move constructor. */
5423 bool
5425 {
5426 tree fns;
5429 {
5432 }
5442 }
5444 /* Returns true iff class T has a move assignment operator. */
5446 bool
5448 {
5449 tree fns;
5452 {
5455 }
5463 }
5465 /* Returns true iff class T has a move constructor that was explicitly
5466 declared in the class body. Note that this is different from
5467 "user-provided", which doesn't include functions that are defaulted in
5468 the class. */
5470 bool
5472 {
5473 tree fns;
5482 {
5486 }
5489 }
5491 /* Returns true iff class T has a move assignment operator that was
5492 explicitly declared in the class body. */
5494 bool
5496 {
5497 tree fns;
5504 {
5508 }
5511 }
5513 /* Nonzero if we need to build up a constructor call when initializing an
5514 object of this class, either because it has a user-declared constructor
5515 or because it doesn't have a default constructor (so we need to give an
5516 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5517 what you care about is whether or not an object can be produced by a
5518 constructor (e.g. so we don't set TREE_READONLY on const variables of
5519 such type); use this function when what you care about is whether or not
5520 to try to call a constructor to create an object. The latter case is
5521 the former plus some cases of constructors that cannot be called. */
5523 bool
5525 {
5526 tree inner;
5536 /* A user-declared constructor might be private, and a constructor might
5537 be trivial but deleted. */
5540 {
5545 }
5547 }
5549 /* Like type_build_ctor_call, but for destructors. */
5551 bool
5553 {
5554 tree inner;
5563 /* A user-declared destructor might be private, and a destructor might
5564 be trivial but deleted. */
5567 {
5572 }
5574 }
5576 /* Remove all zero-width bit-fields from T. */
5578 static void
5580 {
5585 {
5588 /* We should not be confused by the fact that grokbitfield
5589 temporarily sets the width of the bit field into
5590 DECL_INITIAL (*fieldsp).
5591 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5592 to that width. */
5596 else
5598 }
5599 }
5601 /* Returns TRUE iff we need a cookie when dynamically allocating an
5602 array whose elements have the indicated class TYPE. */
5604 static bool
5606 {
5607 tree fns;
5612 /* If there's a non-trivial destructor, we need a cookie. In order
5613 to iterate through the array calling the destructor for each
5614 element, we'll have to know how many elements there are. */
5618 /* If the usual deallocation function is a two-argument whose second
5619 argument is of type `size_t', then we have to pass the size of
5620 the array to the deallocation function, so we will need to store
5621 a cookie. */
5625 /* If there are no `operator []' members, or the lookup is
5626 ambiguous, then we don't need a cookie. */
5629 /* Loop through all of the functions. */
5631 {
5632 tree fn;
5633 tree second_parm;
5635 /* Select the current function. */
5637 /* See if this function is a one-argument delete function. If
5638 it is, then it will be the usual deallocation function. */
5642 /* Do not consider this function if its second argument is an
5643 ellipsis. */
5646 /* Otherwise, if we have a two-argument function and the second
5647 argument is `size_t', it will be the usual deallocation
5648 function -- unless there is one-argument function, too. */
5652 }
5655 }
5657 /* Finish computing the `literal type' property of class type T.
5659 At this point, we have already processed base classes and
5660 non-static data members. We need to check whether the copy
5661 constructor is trivial, the destructor is trivial, and there
5662 is a trivial default constructor or at least one constexpr
5663 constructor other than the copy constructor. */
5665 static void
5667 {
5668 tree fn;
5684 {
5687 {
5691 }
5692 }
5693 }
5695 /* T is a non-literal type used in a context which requires a constant
5696 expression. Explain why it isn't literal. */
5698 void
5700 {
5710 /* Already explained. */
5719 {
5721 "default constructor, and has no constexpr constructor that "
5724 {
5725 /* Note that we can't simply call locate_ctor because when the
5726 constructor is deleted it just returns NULL_TREE. */
5727 tree fns;
5729 {
5736 {
5739 else
5742 }
5743 }
5744 }
5745 }
5746 else
5747 {
5751 {
5754 {
5759 }
5760 }
5762 {
5763 tree ftype;
5768 {
5771 field);
5774 }
5778 }
5779 }
5780 }
5782 /* Check the validity of the bases and members declared in T. Add any
5783 implicitly-generated functions (like copy-constructors and
5784 assignment operators). Compute various flag bits (like
5785 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5786 level: i.e., independently of the ABI in use. */
5788 static void
5790 {
5791 /* Nonzero if the implicitly generated copy constructor should take
5792 a non-const reference argument. */
5794 /* Nonzero if the implicitly generated assignment operator
5795 should take a non-const reference argument. */
5797 tree access_decls;
5800 tree fn;
5802 /* By default, we use const reference arguments and generate default
5803 constructors. */
5807 /* Check all the base-classes and set FMEM members to point to arrays
5808 of potential interest. */
5811 /* Deduce noexcept on destructors. This needs to happen after we've set
5812 triviality flags appropriately for our bases. */
5816 /* Check all the method declarations. */
5819 /* Save the initial values of these flags which only indicate whether
5820 or not the class has user-provided functions. As we analyze the
5821 bases and members we can set these flags for other reasons. */
5825 /* Check all the data member declarations. We cannot call
5826 check_field_decls until we have called check_bases check_methods,
5827 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5828 being set appropriately. */
5833 /* A nearly-empty class has to be vptr-containing; a nearly empty
5834 class contains just a vptr. */
5838 /* Do some bookkeeping that will guide the generation of implicitly
5839 declared member functions. */
5842 /* We need to call a constructor for this class if it has a
5843 user-provided constructor, or if the default constructor is going
5844 to initialize the vptr. (This is not an if-and-only-if;
5845 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5846 themselves need constructing.) */
5849 /* [dcl.init.aggr]
5851 An aggregate is an array or a class with no user-provided
5852 constructors ... and no virtual functions.
5854 Again, other conditions for being an aggregate are checked
5855 elsewhere. */
5859 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5860 retain the old definition internally for ABI reasons. */
5869 /* If the only explicitly declared default constructor is user-provided,
5870 set TYPE_HAS_COMPLEX_DFLT. */
5876 /* Warn if a public base of a polymorphic type has an accessible
5877 non-virtual destructor. It is only now that we know the class is
5878 polymorphic. Although a polymorphic base will have a already
5879 been diagnosed during its definition, we warn on use too. */
5881 {
5884 tree base_binfo;
5888 {
5896 basetype);
5897 }
5898 }
5900 /* If the class has no user-declared constructor, but does have
5901 non-static const or reference data members that can never be
5902 initialized, issue a warning. */
5904 /* Classes with user-declared constructors are presumed to
5905 initialize these members. */
5907 /* Aggregates can be initialized with brace-enclosed
5908 initializers. */
5910 {
5911 tree field;
5914 {
5915 tree type;
5932 }
5933 }
5935 /* Synthesize any needed methods. */
5937 cant_have_const_ctor,
5938 no_const_asn_ref);
5940 /* Check defaulted declarations here so we have cant_have_const_ctor
5941 and don't need to worry about clones. */
5944 {
5947 {
5948 bool imp_const_p
5954 /* If the function is defaulted outside the class, we just
5955 give the synthesis error. */
5958 }
5960 }
5963 {
5964 /* "This class type is not an aggregate." */
5966 }
5968 /* Compute the 'literal type' property before we
5969 do anything with non-static member functions. */
5972 /* Create the in-charge and not-in-charge variants of constructors
5973 and destructors. */
5976 /* Process the using-declarations. */
5980 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5983 /* Figure out whether or not we will need a cookie when dynamically
5984 allocating an array of this type. */
5987 }
5989 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5990 accordingly. If a new vfield was created (because T doesn't have a
5991 primary base class), then the newly created field is returned. It
5992 is not added to the TYPE_FIELDS list; it is the caller's
5993 responsibility to do that. Accumulate declared virtual functions
5994 on VIRTUALS_P. */
5996 static tree
5998 {
5999 tree fn;
6001 /* Collect the virtual functions declared in T. */
6006 {
6015 }
6017 /* If we couldn't find an appropriate base class, create a new field
6018 here. Even if there weren't any new virtual functions, we might need a
6019 new virtual function table if we're supposed to include vptrs in
6020 all classes that need them. */
6022 {
6023 /* We build this decl with vtbl_ptr_type_node, which is a
6024 `vtable_entry_type*'. It might seem more precise to use
6025 `vtable_entry_type (*)[N]' where N is the number of virtual
6026 functions. However, that would require the vtable pointer in
6027 base classes to have a different type than the vtable pointer
6028 in derived classes. We could make that happen, but that
6029 still wouldn't solve all the problems. In particular, the
6030 type-based alias analysis code would decide that assignments
6031 to the base class vtable pointer can't alias assignments to
6032 the derived class vtable pointer, since they have different
6033 types. Thus, in a derived class destructor, where the base
6034 class constructor was inlined, we could generate bad code for
6035 setting up the vtable pointer.
6037 Therefore, we use one type for all vtable pointers. We still
6038 use a type-correct type; it's just doesn't indicate the array
6039 bounds. That's better than using `void*' or some such; it's
6040 cleaner, and it let's the alias analysis code know that these
6041 stores cannot alias stores to void*! */
6042 tree field;
6055 /* This class is non-empty. */
6059 }
6062 }
6064 /* Add OFFSET to all base types of BINFO which is a base in the
6065 hierarchy dominated by T.
6067 OFFSET, which is a type offset, is number of bytes. */
6069 static void
6071 {
6073 tree primary_binfo;
6074 tree base_binfo;
6076 /* Update BINFO's offset. */
6081 offset));
6083 /* Find the primary base class. */
6089 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
6090 downwards. */
6092 {
6093 /* Don't do the primary base twice. */
6101 }
6102 }
6104 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6105 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6106 empty subobjects of T. */
6108 static void
6110 {
6111 tree vbase;
6118 /* Find the last field. The artificial fields created for virtual
6119 bases will go after the last extant field to date. */
6124 /* Go through the virtual bases, allocating space for each virtual
6125 base that is not already a primary base class. These are
6126 allocated in inheritance graph order. */
6128 {
6133 {
6134 /* This virtual base is not a primary base of any class in the
6135 hierarchy, so we have to add space for it. */
6138 }
6139 }
6140 }
6142 /* Returns the offset of the byte just past the end of the base class
6143 BINFO. */
6145 static tree
6147 {
6148 tree size;
6153 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6154 allocate some space for it. It cannot have virtual bases, so
6155 TYPE_SIZE_UNIT is fine. */
6157 else
6161 }
6163 /* Returns the offset of the byte just past the end of the base class
6164 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6165 only non-virtual bases are included. */
6167 static tree
6169 {
6172 tree binfo;
6173 tree base_binfo;
6174 tree offset;
6179 {
6189 }
6194 {
6198 }
6201 }
6203 /* Warn about bases of T that are inaccessible because they are
6204 ambiguous. For example:
6206 struct S {};
6207 struct T : public S {};
6208 struct U : public S, public T {};
6210 Here, `(S*) new U' is not allowed because there are two `S'
6211 subobjects of U. */
6213 static void
6215 {
6218 tree basetype;
6219 tree binfo;
6220 tree base_binfo;
6222 /* If there are no repeated bases, nothing can be ambiguous. */
6226 /* Check direct bases. */
6229 {
6235 }
6237 /* Check for ambiguous virtual bases. */
6241 {
6247 }
6248 }
6250 /* Compare two INTEGER_CSTs K1 and K2. */
6252 static int
6254 {
6256 }
6258 /* Increase the size indicated in RLI to account for empty classes
6259 that are "off the end" of the class. */
6261 static void
6263 {
6264 tree eoc;
6265 tree rli_size;
6267 /* It might be the case that we grew the class to allocate a
6268 zero-sized base class. That won't be reflected in RLI, yet,
6269 because we are willing to overlay multiple bases at the same
6270 offset. However, now we need to make sure that RLI is big enough
6271 to reflect the entire class. */
6277 {
6278 /* The size should have been rounded to a whole byte. */
6281 rli->bitpos
6290 }
6291 }
6293 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6294 BINFO_OFFSETs for all of the base-classes. Position the vtable
6295 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6297 static void
6299 {
6300 tree non_static_data_members;
6301 tree field;
6302 tree vptr;
6303 record_layout_info rli;
6304 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6305 types that appear at that offset. */
6306 splay_tree empty_base_offsets;
6307 /* True if the last field laid out was a bit-field. */
6309 /* The location at which the next field should be inserted. */
6311 /* T, as a base class. */
6312 tree base_t;
6314 /* Keep track of the first non-static data member. */
6317 /* Start laying out the record. */
6320 /* Mark all the primary bases in the hierarchy. */
6323 /* Create a pointer to our virtual function table. */
6326 /* The vptr is always the first thing in the class. */
6328 {
6333 }
6334 else
6337 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6342 /* Layout the non-static data members. */
6344 {
6345 tree type;
6346 tree padding;
6348 /* We still pass things that aren't non-static data members to
6349 the back end, in case it wants to do something with them. */
6351 {
6353 /* If the static data member has incomplete type, keep track
6354 of it so that it can be completed later. (The handling
6355 of pending statics in finish_record_layout is
6356 insufficient; consider:
6358 struct S1;
6359 struct S2 { static S1 s1; };
6361 At this point, finish_record_layout will be called, but
6362 S1 is still incomplete.) */
6364 {
6366 /* The visibility of static data members is determined
6367 at their point of declaration, not their point of
6368 definition. */
6370 }
6372 }
6380 /* If this field is a bit-field whose width is greater than its
6381 type, then there are some special rules for allocating
6382 it. */
6385 {
6387 tree integer_type;
6389 /* We must allocate the bits as if suitably aligned for the
6390 longest integer type that fits in this many bits. type
6391 of the field. Then, we are supposed to use the left over
6392 bits as additional padding. */
6401 /* ITK now indicates a type that is too large for the
6402 field. We have to back up by one to find the largest
6403 type that fits. */
6404 do
6405 {
6410 /* Figure out how much additional padding is required. */
6412 {
6414 /* In a union, the padding field must have the full width
6415 of the bit-field; all fields start at offset zero. */
6417 else
6420 }
6422 /* An unnamed bitfield does not normally affect the
6423 alignment of the containing class on a target where
6424 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6425 make any exceptions for unnamed bitfields when the
6426 bitfields are longer than their types. Therefore, we
6427 temporarily give the field a name. */
6429 {
6432 }
6438 empty_base_offsets);
6441 /* Now that layout has been performed, set the size of the
6442 field to the size of its declared type; the rest of the
6443 field is effectively invisible. */
6445 /* We must also reset the DECL_MODE of the field. */
6447 }
6448 else
6450 empty_base_offsets);
6452 /* Remember the location of any empty classes in FIELD. */
6455 empty_base_offsets,
6458 /* If a bit-field does not immediately follow another bit-field,
6459 and yet it starts in the middle of a byte, we have failed to
6460 comply with the ABI. */
6463 /* The TREE_NO_WARNING flag gets set by Objective-C when
6464 laying out an Objective-C class. The ObjC ABI differs
6465 from the C++ ABI, and so we do not want a warning
6466 here. */
6468 && !last_field_was_bitfield
6471 bitsize_unit_node)))
6473 "offset of %qD is not ABI-compliant and may "
6476 /* The middle end uses the type of expressions to determine the
6477 possible range of expression values. In order to optimize
6478 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6479 must be made aware of the width of "i", via its type.
6481 Because C++ does not have integer types of arbitrary width,
6482 we must (for the purposes of the front end) convert from the
6483 type assigned here to the declared type of the bitfield
6484 whenever a bitfield expression is used as an rvalue.
6485 Similarly, when assigning a value to a bitfield, the value
6486 must be converted to the type given the bitfield here. */
6488 {
6493 {
6500 }
6501 }
6503 /* If we needed additional padding after this field, add it
6504 now. */
6506 {
6507 tree padding_field;
6510 FIELD_DECL,
6511 NULL_TREE,
6512 char_type_node);
6519 NULL_TREE,
6520 empty_base_offsets);
6521 }
6524 }
6527 {
6528 /* Make sure that we are on a byte boundary so that the size of
6529 the class without virtual bases will always be a round number
6530 of bytes. */
6533 }
6535 /* Delete all zero-width bit-fields from the list of fields. Now
6536 that the type is laid out they are no longer important. */
6539 /* Create the version of T used for virtual bases. We do not use
6540 make_class_type for this version; this is an artificial type. For
6541 a POD type, we just reuse T. */
6543 {
6546 /* Set the size and alignment for the new type. */
6547 tree eoc;
6549 /* If the ABI version is not at least two, and the last
6550 field was a bit-field, RLI may not be on a byte
6551 boundary. In particular, rli_size_unit_so_far might
6552 indicate the last complete byte, while rli_size_so_far
6553 indicates the total number of bits used. Therefore,
6554 rli_size_so_far, rather than rli_size_unit_so_far, is
6555 used to compute TYPE_SIZE_UNIT. */
6563 eoc);
6573 /* Copy the fields from T. */
6577 {
6581 }
6584 /* Record the base version of the type. */
6587 }
6588 else
6591 /* Every empty class contains an empty class. */
6595 /* Set the TYPE_DECL for this type to contain the right
6596 value for DECL_OFFSET, so that we can use it as part
6597 of a COMPONENT_REF for multiple inheritance. */
6600 /* Now fix up any virtual base class types that we left lying
6601 around. We must get these done before we try to lay out the
6602 virtual function table. As a side-effect, this will remove the
6603 base subobject fields. */
6606 /* Make sure that empty classes are reflected in RLI at this
6607 point. */
6610 /* Make sure not to create any structures with zero size. */
6616 /* If this is a non-POD, declaring it packed makes a difference to how it
6617 can be used as a field; don't let finalize_record_size undo it. */
6621 /* Let the back end lay out the type. */
6630 /* Warn about bases that can't be talked about due to ambiguity. */
6633 /* Now that we're done with layout, give the base fields the real types. */
6638 /* Clean up. */
6645 }
6647 /* Determine the "key method" for the class type indicated by TYPE,
6648 and set CLASSTYPE_KEY_METHOD accordingly. */
6650 void
6652 {
6653 tree method;
6656 || processing_template_decl
6661 /* The key method is the first non-pure virtual function that is not
6662 inline at the point of class definition. On some targets the
6663 key function may not be inline; those targets should not call
6664 this function until the end of the translation unit. */
6671 {
6674 }
6677 }
6680 /* Allocate and return an instance of struct sorted_fields_type with
6681 N fields. */
6685 {
6692 }
6694 /* Helper of find_flexarrays. Return true when FLD refers to a non-static
6695 class data member of non-zero size, otherwise false. */
6699 {
6707 {
6711 }
6714 }
6716 /* Used by find_flexarrays and related. */
6718 /* The first flexible array member or non-zero array member found
6719 in order of layout. */
6720 tree array;
6721 /* First non-static non-empty data member in the class or its bases. */
6722 tree first;
6723 /* First non-static non-empty data member following either the flexible
6724 array member, if found, or the zero-length array member. */
6725 tree after;
6726 };
6728 /* Find either the first flexible array member or the first zero-length
6729 array, in that order or preference, among members of class T (but not
6730 its base classes), and set members of FMEM accordingly. */
6732 static void
6734 {
6736 {
6737 /* Find the next non-static data member if it exists. */
6746 {
6747 /* Members of anonymous structs and unions are treated as if
6748 they were members of the containing class. Descend into
6749 the anonymous struct or union and find a flexible array
6750 member or zero-length array among its fields. */
6753 }
6755 /* Skip anything that's not a (non-static) data member. */
6759 /* Skip virtual table pointers. */
6764 {
6765 /* Remember the first non-static data member. */
6769 /* Remember the first non-static data member after the flexible
6770 array member, if one has been found, or the zero-length array
6771 if it has been found. */
6774 }
6776 /* Skip non-arrays. */
6780 /* Determine the upper bound of the array if it has one. */
6782 {
6784 {
6785 /* Make a record of the zero-length array if either one
6786 such field or a flexible array member has been seen to
6787 handle the pathological and unlikely case of multiple
6788 such members. */
6791 }
6793 /* Remember the first zero-length array unless a flexible array
6794 member has already been seen. */
6796 }
6797 else
6798 {
6799 /* Flexible array members have no upper bound. */
6801 {
6802 /* Replace the zero-length array if it's been stored and
6803 reset the after pointer. */
6805 {
6808 }
6809 }
6810 else
6812 }
6813 }
6814 }
6816 /* Issue diagnostics for invalid flexible array members or zero-length
6817 arrays that are not the last elements of the containing class or its
6818 base classes or that are its sole members. */
6820 static void
6822 {
6823 /* Members of anonymous structs and unions are considered to be members
6824 of the containing struct or union. */
6831 {
6841 }
6842 else
6843 {
6850 {
6854 /* In the unlikely event that the member following the flexible
6855 array member is declared in a different class, point to it.
6856 Otherwise it should be obvious. */
6864 }
6865 }
6866 }
6869 /* Recursively check to make sure that any flexible array or zero-length
6870 array members of class T or its bases are valid (i.e., not the sole
6871 non-static data member of T and, if one exists, that it is the last
6872 non-static data member of T and its base classes. FMEM is expected
6873 to be initially null and is used internally by recursive calls to
6874 the function. Issue the appropriate diagnostics for the array member
6875 that fails the checks. */
6877 static void
6879 {
6880 /* Initialize the result of a search for flexible array and zero-length
6881 array members. Avoid doing any work if the most interesting FMEM data
6882 have already been populated. */
6889 /* Recursively check the primary base class first. */
6891 {
6894 }
6896 /* Recursively check the base classes. */
6899 {
6902 /* The primary base class was already checked above. */
6906 /* Virtual base classes are at the end. */
6910 /* Check the base class. */
6912 }
6915 {
6916 /* Check virtual base classes only once per derived class.
6917 I.e., this check is not performed recursively for base
6918 classes. */
6920 tree base_binfo;
6924 {
6925 /* Check the virtual base class. */
6929 }
6930 }
6932 /* Search the members of the current (derived) class. */
6936 {
6937 /* Issue diagnostics for invalid flexible and zero-length array members
6938 found in base classes or among the members of the current class. */
6940 }
6941 }
6943 /* Perform processing required when the definition of T (a class type)
6944 is complete. Diagnose invalid definitions of flexible array members
6945 and zero-size arrays. */
6947 void
6949 {
6950 tree x;
6951 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6955 {
6960 }
6962 /* If this type was previously laid out as a forward reference,
6963 make sure we lay it out again. */
6967 /* Make assumptions about the class; we'll reset the flags if
6968 necessary. */
6974 /* Do end-of-class semantic processing: checking the validity of the
6975 bases and members and add implicitly generated methods. */
6978 /* Find the key method. */
6980 {
6981 /* The Itanium C++ ABI permits the key method to be chosen when
6982 the class is defined -- even though the key method so
6983 selected may later turn out to be an inline function. On
6984 some systems (such as ARM Symbian OS) the key method cannot
6985 be determined until the end of the translation unit. On such
6986 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6987 will cause the class to be added to KEYED_CLASSES. Then, in
6988 finish_file we will determine the key method. */
6992 /* If a polymorphic class has no key method, we may emit the vtable
6993 in every translation unit where the class definition appears. If
6994 we're devirtualizing, we can look into the vtable even if we
6995 aren't emitting it. */
6998 }
7000 /* Layout the class itself. */
7003 /* We use the base type for trivial assignments, and hence it
7004 needs a mode. */
7007 /* With the layout complete, check for flexible array members and
7008 zero-length arrays that might overlap other members in the final
7009 layout. */
7014 /* If necessary, create the primary vtable for this class. */
7016 {
7017 /* We must enter these virtuals into the table. */
7021 /* Here we know enough to change the type of our virtual
7022 function table, but we will wait until later this function. */
7025 /* If we're warning about ABI tags, check the types of the new
7026 virtual functions. */
7030 }
7033 {
7035 tree fn;
7042 /* Add entries for virtual functions introduced by this class. */
7046 /* Set DECL_VINDEX for all functions declared in this class. */
7048 fn;
7050 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
7052 {
7056 /* A thunk. We should never be calling this entry directly
7057 from this vtable -- we'd use the entry for the non
7058 thunk base function. */
7062 }
7063 }
7070 /* Complete the rtl for any static member objects of the type we're
7071 working on. */
7078 /* Done with FIELDS...now decide whether to sort these for
7079 faster lookups later.
7081 We use a small number because most searches fail (succeeding
7082 ultimately as the search bores through the inheritance
7083 hierarchy), and we want this failure to occur quickly. */
7087 /* Complain if one of the field types requires lower visibility. */
7090 /* Make the rtl for any new vtables we have created, and unmark
7091 the base types we marked. */
7094 /* Build the VTT for T. */
7097 /* This warning does not make sense for Java classes, since they
7098 cannot have destructors. */
7103 "%q#T has virtual functions and accessible"
7111 /* Class layout, assignment of virtual table slots, etc., is now
7112 complete. Give the back end a chance to tweak the visibility of
7113 the class or perform any other required target modifications. */
7123 /* Finish debugging output for this type. */
7127 {
7130 {
7133 }
7135 {
7138 else
7139 {
7142 }
7144 }
7146 {
7148 "the type of the first field has a different ABI from the "
7151 }
7152 }
7153 }
7155 /* Insert FIELDS into T for the sorted case if the FIELDS count is
7156 equal to THRESHOLD or greater than THRESHOLD. */
7158 static void
7160 {
7163 {
7168 }
7169 }
7171 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
7173 void
7175 {
7178 {
7180 int n_fields
7191 }
7192 }
7194 /* When T was built up, the member declarations were added in reverse
7195 order. Rearrange them to declaration order. */
7197 void
7199 {
7200 tree next;
7201 tree prev;
7202 tree x;
7204 /* The following lists are all in reverse order. Put them in
7205 declaration order now. */
7209 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
7210 reverse order, so we can't just use nreverse. */
7215 {
7219 }
7221 {
7225 }
7226 }
7228 tree
7230 {
7233 /* Now that we've got all the field declarations, reverse everything
7234 as necessary. */
7240 /* Nadger the current location so that diagnostics point to the start of
7241 the struct, not the end. */
7245 {
7246 tree x;
7252 /* We need to emit an error message if this type was used as a parameter
7253 and it is an abstract type, even if it is a template. We construct
7254 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
7255 account and we call complete_vars with this type, which will check
7256 the PARM_DECLS. Note that while the type is being defined,
7257 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
7258 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
7264 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
7265 an enclosing scope is a template class, so that this function be
7266 found by lookup_fnfields_1 when the using declaration is not
7267 instantiated yet. */
7270 {
7275 }
7277 /* Remember current #pragma pack value. */
7280 /* Fix up any variants we've already built. */
7282 {
7287 }
7288 }
7289 else
7293 {
7294 /* People keep complaining that the compiler crashes on an invalid
7295 definition of initializer_list, so I guess we should explicitly
7296 reject it. What the compiler internals care about is that it's a
7297 template and has a pointer field followed by an integer field. */
7300 {
7303 {
7307 }
7308 }
7311 "definition of std::initializer_list does not match "
7313 }
7321 else
7325 /* Lambdas are defined by the LAMBDA_EXPR. */
7330 }
7331 \f
7332 /* Hash table to avoid endless recursion when handling references. */
7335 /* Return the dynamic type of INSTANCE, if known.
7336 Used to determine whether the virtual function table is needed
7337 or not.
7339 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7340 of our knowledge of its type. *NONNULL should be initialized
7341 before this function is called. */
7343 static tree
7345 {
7346 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7349 {
7353 else
7357 /* This is a call to a constructor, hence it's never zero. */
7359 {
7363 }
7367 /* This is a call to a constructor, hence it's never zero. */
7369 {
7373 }
7382 /* Propagate nonnull. */
7387 CASE_CONVERT:
7393 {
7394 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7395 with a real object -- given &p->f, p can still be null. */
7397 /* ??? Probably should check DECL_WEAK here. */
7400 }
7404 /* If this component is really a base class reference, then the field
7405 itself isn't definitive. */
7414 {
7418 }
7419 /* fall through. */
7424 {
7428 }
7430 {
7434 /* if we're in a ctor or dtor, we know our type. If
7435 current_class_ptr is set but we aren't in a function, we're in
7436 an NSDMI (and therefore a constructor). */
7441 {
7445 }
7446 }
7448 {
7449 /* We only need one hash table because it is always left empty. */
7451 fixed_type_or_null_ref_ht
7454 /* Reference variables should be references to objects. */
7458 /* Enter the INSTANCE in a table to prevent recursion; a
7459 variable's initializer may refer to the variable
7460 itself. */
7465 {
7466 tree type;
7475 }
7476 }
7481 }
7482 #undef RECUR
7483 }
7485 /* Return nonzero if the dynamic type of INSTANCE is known, and
7486 equivalent to the static type. We also handle the case where
7487 INSTANCE is really a pointer. Return negative if this is a
7488 ctor/dtor. There the dynamic type is known, but this might not be
7489 the most derived base of the original object, and hence virtual
7490 bases may not be laid out according to this type.
7492 Used to determine whether the virtual function table is needed
7493 or not.
7495 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7496 of our knowledge of its type. *NONNULL should be initialized
7497 before this function is called. */
7499 int
7501 {
7504 tree fixed;
7506 /* processing_template_decl can be false in a template if we're in
7507 instantiate_non_dependent_expr, but we still want to suppress
7508 this check. */
7510 {
7511 /* In a template we only care about the type of the result. */
7515 }
7525 }
7527 \f
7528 void
7530 {
7533 current_class_stack
7541 }
7543 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7545 static void
7547 {
7548 tree type;
7550 /* We are re-entering the same class we just left, so we don't
7551 have to search the whole inheritance matrix to find all the
7552 decls to bind again. Instead, we install the cached
7553 class_shadowed list and walk through it binding names. */
7556 /* Restore IDENTIFIER_TYPE_VALUE. */
7558 type;
7561 }
7563 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7564 appropriate for TYPE.
7566 So that we may avoid calls to lookup_name, we cache the _TYPE
7567 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7569 For multiple inheritance, we perform a two-pass depth-first search
7570 of the type lattice. */
7572 void
7574 {
7575 class_stack_node_t csn;
7579 /* Make sure there is enough room for the new entry on the stack. */
7581 {
7583 current_class_stack
7585 current_class_stack_size);
7586 }
7588 /* Insert a new entry on the class stack. */
7595 current_class_depth++;
7597 /* Now set up the new type. */
7603 /* By default, things in classes are private, while things in
7604 structures or unions are public. */
7606 ? access_private_node
7612 {
7613 /* Forcibly remove any old class remnants. */
7615 }
7621 else
7623 }
7625 /* When we exit a toplevel class scope, we save its binding level so
7626 that we can restore it quickly. Here, we've entered some other
7627 class, so we must invalidate our cache. */
7629 void
7631 {
7633 }
7635 /* Get out of the current class scope. If we were in a class scope
7636 previously, that is the one popped to. */
7638 void
7640 {
7643 current_class_depth--;
7649 }
7651 /* Mark the top of the class stack as hidden. */
7653 void
7655 {
7658 }
7660 /* Mark the top of the class stack as un-hidden. */
7662 void
7664 {
7667 }
7669 /* Returns 1 if the class type currently being defined is either T or
7670 a nested type of T. Returns the type from the current_class_stack,
7671 which might be equivalent to but not equal to T in case of
7672 constrained partial specializations. */
7674 tree
7676 {
7684 /* We start looking from 1 because entry 0 is from global scope,
7685 and has no type. */
7687 {
7688 tree c;
7691 else
7692 {
7696 }
7701 }
7703 }
7705 /* If either current_class_type or one of its enclosing classes are derived
7706 from T, return the appropriate type. Used to determine how we found
7707 something via unqualified lookup. */
7709 tree
7711 {
7714 /* The bases of a dependent type are unknown. */
7725 {
7730 }
7733 }
7735 /* Return the outermost enclosing class type that is still open, or
7736 NULL_TREE. */
7738 tree
7740 {
7747 {
7754 }
7756 }
7758 /* Returns the innermost class type which is not a lambda closure type. */
7760 tree
7762 {
7765 /* We start looking from 1 because entry 0 is from global scope,
7766 and has no type. */
7768 {
7769 tree c;
7772 else
7773 {
7777 }
7782 }
7784 }
7786 /* When entering a class scope, all enclosing class scopes' names with
7787 static meaning (static variables, static functions, types and
7788 enumerators) have to be visible. This recursive function calls
7789 pushclass for all enclosing class contexts until global or a local
7790 scope is reached. TYPE is the enclosed class. */
7792 void
7794 {
7795 /* A namespace might be passed in error cases, like A::B:C. */
7803 }
7805 /* Undoes a push_nested_class call. */
7807 void
7809 {
7815 }
7817 /* Returns the number of extern "LANG" blocks we are nested within. */
7819 int
7821 {
7823 }
7825 /* Set global variables CURRENT_LANG_NAME to appropriate value
7826 so that behavior of name-mangling machinery is correct. */
7828 void
7830 {
7834 {
7836 }
7838 {
7840 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7841 (See record_builtin_java_type in decl.c.) However, that causes
7842 incorrect debug entries if these types are actually used.
7843 So we re-enable debug output after extern "Java". */
7852 }
7854 {
7856 }
7857 else
7859 }
7861 /* Get out of the current language scope. */
7863 void
7865 {
7867 }
7868 \f
7869 /* Type instantiation routines. */
7871 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7872 matches the TARGET_TYPE. If there is no satisfactory match, return
7873 error_mark_node, and issue an error & warning messages under
7874 control of FLAGS. Permit pointers to member function if FLAGS
7875 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7876 a template-id, and EXPLICIT_TARGS are the explicitly provided
7877 template arguments.
7879 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7880 is the base path used to reference those member functions. If
7881 the address is resolved to a member function, access checks will be
7882 performed and errors issued if appropriate. */
7884 static tree
7886 tree overload,
7887 tsubst_flags_t complain,
7889 tree explicit_targs,
7890 tree access_path)
7891 {
7892 /* Here's what the standard says:
7894 [over.over]
7896 If the name is a function template, template argument deduction
7897 is done, and if the argument deduction succeeds, the deduced
7898 arguments are used to generate a single template function, which
7899 is added to the set of overloaded functions considered.
7901 Non-member functions and static member functions match targets of
7902 type "pointer-to-function" or "reference-to-function." Nonstatic
7903 member functions match targets of type "pointer-to-member
7904 function;" the function type of the pointer to member is used to
7905 select the member function from the set of overloaded member
7906 functions. If a nonstatic member function is selected, the
7907 reference to the overloaded function name is required to have the
7908 form of a pointer to member as described in 5.3.1.
7910 If more than one function is selected, any template functions in
7911 the set are eliminated if the set also contains a non-template
7912 function, and any given template function is eliminated if the
7913 set contains a second template function that is more specialized
7914 than the first according to the partial ordering rules 14.5.5.2.
7915 After such eliminations, if any, there shall remain exactly one
7916 selected function. */
7919 /* We store the matches in a TREE_LIST rooted here. The functions
7920 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7921 interoperability with most_specialized_instantiation. */
7923 tree fn;
7924 tree target_fn_type;
7926 /* By the time we get here, we should be seeing only real
7927 pointer-to-member types, not the internal POINTER_TYPE to
7928 METHOD_TYPE representation. */
7934 /* Check that the TARGET_TYPE is reasonable. */
7939 /* This is OK, too. */
7942 /* This is OK, too. This comes from a conversion to reference
7943 type. */
7945 else
7946 {
7952 }
7954 /* Non-member functions and static member functions match targets of type
7955 "pointer-to-function" or "reference-to-function." Nonstatic member
7956 functions match targets of type "pointer-to-member-function;" the
7957 function type of the pointer to member is used to select the member
7958 function from the set of overloaded member functions.
7960 So figure out the FUNCTION_TYPE that we want to match against. */
7963 /* If we can find a non-template function that matches, we can just
7964 use it. There's no point in generating template instantiations
7965 if we're just going to throw them out anyhow. But, of course, we
7966 can only do this when we don't *need* a template function. */
7968 {
7969 tree fns;
7972 {
7976 /* We're not looking for templates just yet. */
7981 /* We're looking for a non-static member, and this isn't
7982 one, or vice versa. */
7985 /* Ignore functions which haven't been explicitly
7986 declared. */
7990 /* See if there's a match. */
7995 }
7996 }
7998 /* Now, if we've already got a match (or matches), there's no need
7999 to proceed to the template functions. But, if we don't have a
8000 match we need to look at them, too. */
8002 {
8003 tree target_arg_types;
8004 tree target_ret_type;
8005 tree fns;
8008 tree arg;
8022 {
8024 tree instantiation;
8025 tree targs;
8028 /* We're only looking for templates. */
8033 /* We're not looking for a non-static member, and this is
8034 one, or vice versa. */
8039 /* If the template has a deduced return type, don't expose it to
8040 template argument deduction. */
8044 /* Try to do argument deduction. */
8051 /* Instantiation failed. */
8054 /* Constraints must be satisfied. This is done before
8055 return type deduction since that instantiates the
8056 function. */
8060 /* And now force instantiation to do return type deduction. */
8062 {
8068 }
8070 /* See if there's a match. */
8075 }
8077 /* Now, remove all but the most specialized of the matches. */
8079 {
8084 NULL_TREE,
8085 NULL_TREE);
8086 }
8087 }
8089 /* Now we should have exactly one function in MATCHES. */
8091 {
8092 /* There were *no* matches. */
8094 {
8097 target_type);
8100 }
8102 }
8104 {
8105 /* There were too many matches. First check if they're all
8106 the same function. */
8111 /* For multi-versioned functions, more than one match is just fine and
8112 decls_match will return false as they are different. */
8120 {
8122 {
8125 target_type);
8127 /* Since print_candidates expects the functions in the
8128 TREE_VALUE slot, we flip them here. */
8133 }
8136 }
8137 }
8139 /* Good, exactly one match. Now, convert it to the correct type. */
8144 {
8152 {
8155 }
8156 }
8158 /* If a pointer to a function that is multi-versioned is requested, the
8159 pointer to the dispatcher function is returned instead. This works
8160 well because indirectly calling the function will dispatch the right
8161 function version at run-time. */
8163 {
8167 /* Mark all the versions corresponding to the dispatcher as used. */
8170 }
8172 /* If we're doing overload resolution purely for the purpose of
8173 determining conversion sequences, we should not consider the
8174 function used. If this conversion sequence is selected, the
8175 function will be marked as used at this point. */
8177 {
8178 /* Make =delete work with SFINAE. */
8183 }
8185 /* We could not check access to member functions when this
8186 expression was originally created since we did not know at that
8187 time to which function the expression referred. */
8189 {
8192 }
8196 else
8197 {
8198 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
8199 will mark the function as addressed, but here we must do it
8200 explicitly. */
8204 }
8205 }
8207 /* This function will instantiate the type of the expression given in
8208 RHS to match the type of LHSTYPE. If errors exist, then return
8209 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
8210 we complain on errors. If we are not complaining, never modify rhs,
8211 as overload resolution wants to try many possible instantiations, in
8212 the hope that at least one will work.
8214 For non-recursive calls, LHSTYPE should be a function, pointer to
8215 function, or a pointer to member function. */
8217 tree
8219 {
8226 {
8230 }
8233 {
8240 /* Microsoft allows `A::f' to be resolved to a
8241 pointer-to-member. */
8242 ;
8243 else
8244 {
8249 }
8250 }
8253 {
8256 }
8258 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
8259 deduce any type information. */
8261 {
8265 }
8267 /* If we instantiate a template, and it is a A ?: C expression
8268 with omitted B, look through the SAVE_EXPR. */
8272 /* There are only a few kinds of expressions that may have a type
8273 dependent on overload resolution. */
8279 /* This should really only be used when attempting to distinguish
8280 what sort of a pointer to function we have. For now, any
8281 arithmetic operation which is not supported on pointers
8282 is rejected as an error. */
8285 {
8287 {
8293 /* Do not lose object's side effects. */
8297 }
8304 /* This can happen if we are forming a pointer-to-member for a
8305 member template. */
8308 /* Fall through. */
8311 {
8315 return
8319 }
8323 return
8327 access_path);
8330 {
8335 }
8342 }
8344 }
8345 \f
8346 /* Return the name of the virtual function pointer field
8347 (as an IDENTIFIER_NODE) for the given TYPE. Note that
8348 this may have to look back through base types to find the
8349 ultimate field name. (For single inheritance, these could
8350 all be the same name. Who knows for multiple inheritance). */
8352 static tree
8354 {
8361 {
8367 }
8375 }
8377 void
8379 {
8386 {
8391 }
8392 }
8394 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8395 according to [class]:
8396 The class-name is also inserted
8397 into the scope of the class itself. For purposes of access checking,
8398 the inserted class name is treated as if it were a public member name. */
8400 void
8402 {
8405 tree saved_cas;
8420 }
8422 /* Returns 1 if TYPE contains only padding bytes. */
8424 int
8426 {
8434 }
8436 /* Returns true if TYPE contains no actual data, just various
8437 possible combinations of empty classes and possibly a vptr. */
8439 bool
8441 {
8443 {
8444 tree field;
8445 tree binfo;
8446 tree base_binfo;
8449 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8450 out, but we'd like to be able to check this before then. */
8461 /* An unnamed bit-field is not a data member. */
8466 }
8471 }
8473 /* Note that NAME was looked up while the current class was being
8474 defined and that the result of that lookup was DECL. */
8476 void
8478 {
8479 splay_tree names_used;
8481 /* If we're not defining a class, there's nothing to do. */
8487 /* If there's already a binding for this NAME, then we don't have
8488 anything to worry about. */
8501 }
8503 /* Note that NAME was declared (as DECL) in the current class. Check
8504 to see that the declaration is valid. */
8506 void
8508 {
8509 splay_tree names_used;
8510 splay_tree_node n;
8512 /* Look to see if we ever used this name. */
8513 names_used
8517 /* The C language allows members to be declared with a type of the same
8518 name, and the C++ standard says this diagnostic is not required. So
8519 allow it in extern "C" blocks unless predantic is specified.
8520 Allow it in all cases if -ms-extensions is specified. */
8526 {
8527 /* [basic.scope.class]
8529 A name N used in a class S shall refer to the same declaration
8530 in its context and when re-evaluated in the completed scope of
8531 S. */
8536 }
8537 }
8539 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8540 Secondary vtables are merged with primary vtables; this function
8541 will return the VAR_DECL for the primary vtable. */
8543 tree
8545 {
8546 tree decl;
8550 {
8553 }
8557 }
8560 /* Returns the binfo for the primary base of BINFO. If the resulting
8561 BINFO is a virtual base, and it is inherited elsewhere in the
8562 hierarchy, then the returned binfo might not be the primary base of
8563 BINFO in the complete object. Check BINFO_PRIMARY_P or
8564 BINFO_LOST_PRIMARY_P to be sure. */
8566 static tree
8568 {
8569 tree primary_base;
8576 }
8578 /* As above, but iterate until we reach the binfo that actually provides the
8579 vptr for BINFO. */
8581 static tree
8583 {
8587 {
8592 }
8594 }
8596 /* Returns true if BINFO gets its vptr from a virtual base of the most derived
8597 type. Note that the virtual inheritance might be above or below BINFO in
8598 the hierarchy. */
8600 bool
8602 {
8606 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is
8607 a morally virtual base. */
8610 }
8612 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8614 static int
8616 {
8620 }
8622 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8623 INDENT should be zero when called from the top level; it is
8624 incremented recursively. IGO indicates the next expected BINFO in
8625 inheritance graph ordering. */
8627 static tree
8630 tree binfo,
8631 tree igo,
8633 {
8635 tree base_binfo;
8643 {
8646 }
8661 {
8665 TFF_PLAIN_IDENTIFIER),
8667 }
8669 {
8672 }
8677 {
8681 {
8685 TFF_PLAIN_IDENTIFIER));
8686 }
8688 {
8692 TFF_PLAIN_IDENTIFIER));
8693 }
8695 {
8699 TFF_PLAIN_IDENTIFIER));
8700 }
8702 {
8706 TFF_PLAIN_IDENTIFIER));
8707 }
8711 }
8717 }
8719 /* Dump the BINFO hierarchy for T. */
8721 static void
8723 {
8735 }
8737 /* Debug interface to hierarchy dumping. */
8739 void
8741 {
8743 }
8745 static void
8747 {
8752 {
8754 }
8755 }
8757 static void
8759 {
8760 tree value;
8762 HOST_WIDE_INT elt;
8770 TFF_PLAIN_IDENTIFIER));
8777 }
8779 static void
8781 {
8789 {
8796 {
8801 }
8805 }
8806 }
8808 static void
8810 {
8818 {
8823 }
8824 }
8826 /* Dump a function or thunk and its thunkees. */
8828 static void
8830 {
8833 tree thunks;
8841 {
8851 else
8857 }
8861 }
8863 /* Dump the thunks for FN. */
8865 void
8867 {
8869 }
8871 /* Virtual function table initialization. */
8873 /* Create all the necessary vtables for T and its base classes. */
8875 static void
8877 {
8878 tree vbase;
8882 /* We lay out the primary and secondary vtables in one contiguous
8883 vtable. The primary vtable is first, followed by the non-virtual
8884 secondary vtables in inheritance graph order. */
8888 /* Then come the virtual bases, also in inheritance graph order. */
8890 {
8894 }
8898 }
8900 /* Initialize the vtable for BINFO with the INITS. */
8902 static void
8904 {
8905 tree decl;
8911 }
8913 /* Build the VTT (virtual table table) for T.
8914 A class requires a VTT if it has virtual bases.
8916 This holds
8917 1 - primary virtual pointer for complete object T
8918 2 - secondary VTTs for each direct non-virtual base of T which requires a
8919 VTT
8920 3 - secondary virtual pointers for each direct or indirect base of T which
8921 has virtual bases or is reachable via a virtual path from T.
8922 4 - secondary VTTs for each direct or indirect virtual base of T.
8924 Secondary VTTs look like complete object VTTs without part 4. */
8926 static void
8928 {
8929 tree type;
8930 tree vtt;
8931 tree index;
8934 /* Build up the initializers for the VTT. */
8939 /* If we didn't need a VTT, we're done. */
8943 /* Figure out the type of the VTT. */
8947 /* Now, build the VTT object itself. */
8950 /* Add the VTT to the vtables list. */
8955 }
8957 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8958 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8959 and CHAIN the vtable pointer for this binfo after construction is
8960 complete. VALUE can also be another BINFO, in which case we recurse. */
8962 static tree
8964 {
8965 tree vt;
8968 {
8974 else
8976 }
8979 }
8981 /* Data for secondary VTT initialization. */
8982 struct secondary_vptr_vtt_init_data
8983 {
8984 /* Is this the primary VTT? */
8987 /* Current index into the VTT. */
8988 tree index;
8990 /* Vector of initializers built up. */
8993 /* The type being constructed by this secondary VTT. */
8994 tree type_being_constructed;
8995 };
8997 /* Recursively build the VTT-initializer for BINFO (which is in the
8998 hierarchy dominated by T). INITS points to the end of the initializer
8999 list to date. INDEX is the VTT index where the next element will be
9000 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
9001 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
9002 for virtual bases of T. When it is not so, we build the constructor
9003 vtables for the BINFO-in-T variant. */
9005 static void
9008 {
9010 tree b;
9011 tree init;
9012 secondary_vptr_vtt_init_data data;
9015 /* We only need VTTs for subobjects with virtual bases. */
9019 /* We need to use a construction vtable if this is not the primary
9020 VTT. */
9022 {
9025 /* Record the offset in the VTT where this sub-VTT can be found. */
9027 }
9029 /* Add the address of the primary vtable for the complete object. */
9033 {
9036 }
9039 /* Recursively add the secondary VTTs for non-virtual bases. */
9044 /* Add secondary virtual pointers for all subobjects of BINFO with
9045 either virtual bases or reachable along a virtual path, except
9046 subobjects that are non-virtual primary bases. */
9056 /* data.inits might have grown as we added secondary virtual pointers.
9057 Make sure our caller knows about the new vector. */
9061 /* Add the secondary VTTs for virtual bases in inheritance graph
9062 order. */
9064 {
9069 }
9070 else
9071 /* Remove the ctor vtables we created. */
9073 }
9075 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
9076 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
9078 static tree
9080 {
9083 /* We don't care about bases that don't have vtables. */
9087 /* We're only interested in proper subobjects of the type being
9088 constructed. */
9092 /* We're only interested in bases with virtual bases or reachable
9093 via a virtual path from the type being constructed. */
9098 /* We're not interested in non-virtual primary bases. */
9102 /* Record the index where this secondary vptr can be found. */
9104 {
9109 {
9110 /* It's a primary virtual base, and this is not a
9111 construction vtable. Find the base this is primary of in
9112 the inheritance graph, and use that base's vtable
9113 now. */
9116 }
9117 }
9119 /* Add the initializer for the secondary vptr itself. */
9122 /* Advance the vtt index. */
9127 }
9129 /* Called from build_vtt_inits via dfs_walk. After building
9130 constructor vtables and generating the sub-vtt from them, we need
9131 to restore the BINFO_VTABLES that were scribbled on. DATA is the
9132 binfo of the base whose sub vtt was generated. */
9134 static tree
9136 {
9140 /* If this class has no vtable, none of its bases do. */
9144 /* This might be a primary base, so have no vtable in this
9145 hierarchy. */
9148 /* If we scribbled the construction vtable vptr into BINFO, clear it
9149 out now. */
9155 }
9157 /* Build the construction vtable group for BINFO which is in the
9158 hierarchy dominated by T. */
9160 static void
9162 {
9163 tree type;
9164 tree vtbl;
9165 tree id;
9166 tree vbase;
9169 /* See if we've already created this construction vtable group. */
9175 /* Build a version of VTBL (with the wrong type) for use in
9176 constructing the addresses of secondary vtables in the
9177 construction vtable group. */
9180 /* Don't export construction vtables from shared libraries. Even on
9181 targets that don't support hidden visibility, this tells
9182 can_refer_decl_in_current_unit_p not to assume that it's safe to
9183 access from a different compilation unit (bz 54314). */
9191 /* Add the vtables for each of our virtual bases using the vbase in T
9192 binfo. */
9194 vbase;
9196 {
9197 tree b;
9204 }
9206 /* Figure out the type of the construction vtable. */
9213 /* Initialize the construction vtable. */
9217 }
9219 /* Add the vtbl initializers for BINFO (and its bases other than
9220 non-virtual primaries) to the list of INITS. BINFO is in the
9221 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
9222 the constructor the vtbl inits should be accumulated for. (If this
9223 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
9224 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
9225 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
9226 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
9227 but are not necessarily the same in terms of layout. */
9229 static void
9231 tree orig_binfo,
9232 tree rtti_binfo,
9233 tree vtbl,
9234 tree t,
9236 {
9238 tree base_binfo;
9243 /* If it doesn't have a vptr, we don't do anything. */
9247 /* If we're building a construction vtable, we're not interested in
9248 subobjects that don't require construction vtables. */
9254 /* Build the initializers for the BINFO-in-T vtable. */
9257 /* Walk the BINFO and its bases. We walk in preorder so that as we
9258 initialize each vtable we can figure out at what offset the
9259 secondary vtable lies from the primary vtable. We can't use
9260 dfs_walk here because we need to iterate through bases of BINFO
9261 and RTTI_BINFO simultaneously. */
9263 {
9264 /* Skip virtual bases. */
9270 inits);
9271 }
9272 }
9274 /* Called from accumulate_vtbl_inits. Adds the initializers for the
9275 BINFO vtable to L. */
9277 static void
9279 tree orig_binfo,
9280 tree rtti_binfo,
9281 tree orig_vtbl,
9282 tree t,
9284 {
9291 {
9292 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
9293 primary virtual base. If it is not the same primary in
9294 the hierarchy of T, we'll need to generate a ctor vtable
9295 for it, to place at its location in T. If it is the same
9296 primary, we still need a VTT entry for the vtable, but it
9297 should point to the ctor vtable for the base it is a
9298 primary for within the sub-hierarchy of RTTI_BINFO.
9300 There are three possible cases:
9302 1) We are in the same place.
9303 2) We are a primary base within a lost primary virtual base of
9304 RTTI_BINFO.
9305 3) We are primary to something not a base of RTTI_BINFO. */
9307 tree b;
9310 /* First, look through the bases we are primary to for RTTI_BINFO
9311 or a virtual base. */
9314 {
9319 }
9320 /* If we run out of primary links, keep looking down our
9321 inheritance chain; we might be an indirect primary. */
9325 found:
9327 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
9328 base B and it is a base of RTTI_BINFO, this is case 2. In
9329 either case, we share our vtable with LAST, i.e. the
9330 derived-most base within B of which we are a primary. */
9333 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
9334 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
9335 binfo_ctor_vtable after everything's been set up. */
9338 /* Otherwise, this is case 3 and we get our own. */
9339 }
9346 {
9347 tree index;
9350 /* Add the initializer for this vtable. */
9354 /* Figure out the position to which the VPTR should point. */
9360 }
9363 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
9364 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
9365 straighten this out. */
9368 /* Throw away any unneeded intializers. */
9370 else
9371 /* For an ordinary vtable, set BINFO_VTABLE. */
9373 }
9377 /* Construct the initializer for BINFO's virtual function table. BINFO
9378 is part of the hierarchy dominated by T. If we're building a
9379 construction vtable, the ORIG_BINFO is the binfo we should use to
9380 find the actual function pointers to put in the vtable - but they
9381 can be overridden on the path to most-derived in the graph that
9382 ORIG_BINFO belongs. Otherwise,
9383 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
9384 BINFO that should be indicated by the RTTI information in the
9385 vtable; it will be a base class of T, rather than T itself, if we
9386 are building a construction vtable.
9388 The value returned is a TREE_LIST suitable for wrapping in a
9389 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9390 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9391 number of non-function entries in the vtable.
9393 It might seem that this function should never be called with a
9394 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9395 base is always subsumed by a derived class vtable. However, when
9396 we are building construction vtables, we do build vtables for
9397 primary bases; we need these while the primary base is being
9398 constructed. */
9400 static void
9402 tree orig_binfo,
9403 tree t,
9404 tree rtti_binfo,
9407 {
9408 tree v;
9409 vtbl_init_data vid;
9411 tree vbinfo;
9415 /* Initialize VID. */
9423 /* The first vbase or vcall offset is at index -3 in the vtable. */
9426 /* Add entries to the vtable for RTTI. */
9429 /* Create an array for keeping track of the functions we've
9430 processed. When we see multiple functions with the same
9431 signature, we share the vcall offsets. */
9433 /* Add the vcall and vbase offset entries. */
9436 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9437 build_vbase_offset_vtbl_entries. */
9442 /* If the target requires padding between data entries, add that now. */
9444 {
9449 /* Move data entries into their new positions and add padding
9450 after the new positions. Iterate backwards so we don't
9451 overwrite entries that we would need to process later. */
9454 ix--)
9455 {
9463 {
9467 null_pointer_node);
9468 }
9469 }
9470 }
9475 /* The initializers for virtual functions were built up in reverse
9476 order. Straighten them out and add them to the running list in one
9477 step. */
9486 /* Go through all the ordinary virtual functions, building up
9487 initializers. */
9489 {
9490 tree delta;
9491 tree vcall_index;
9498 {
9502 {
9505 }
9507 }
9509 /* If the only definition of this function signature along our
9510 primary base chain is from a lost primary, this vtable slot will
9511 never be used, so just zero it out. This is important to avoid
9512 requiring extra thunks which cannot be generated with the function.
9514 We first check this in update_vtable_entry_for_fn, so we handle
9515 restored primary bases properly; we also need to do it here so we
9516 zero out unused slots in ctor vtables, rather than filling them
9517 with erroneous values (though harmless, apart from relocation
9518 costs). */
9523 {
9524 /* Pull the offset for `this', and the function to call, out of
9525 the list. */
9532 /* You can't call an abstract virtual function; it's abstract.
9533 So, we replace these functions with __pure_virtual. */
9535 {
9538 {
9540 abort_fndecl_addr
9544 }
9545 }
9546 /* Likewise for deleted virtuals. */
9548 {
9557 }
9558 else
9559 {
9561 {
9565 }
9566 /* Take the address of the function, considering it to be of an
9567 appropriate generic type. */
9571 /* Don't refer to a virtual destructor from a constructor
9572 vtable or a vtable for an abstract class, since destroying
9573 an object under construction is undefined behavior and we
9574 don't want it to be considered a candidate for speculative
9575 devirtualization. But do create the thunk for ABI
9576 compliance. */
9581 }
9582 }
9584 /* And add it to the chain of initializers. */
9586 {
9591 else
9593 {
9599 }
9600 }
9601 else
9603 }
9604 }
9606 /* Adds to vid->inits the initializers for the vbase and vcall
9607 offsets in BINFO, which is in the hierarchy dominated by T. */
9609 static void
9611 {
9612 tree b;
9614 /* If this is a derived class, we must first create entries
9615 corresponding to the primary base class. */
9620 /* Add the vbase entries for this base. */
9622 /* Add the vcall entries for this base. */
9624 }
9626 /* Returns the initializers for the vbase offset entries in the vtable
9627 for BINFO (which is part of the class hierarchy dominated by T), in
9628 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9629 where the next vbase offset will go. */
9631 static void
9633 {
9634 tree vbase;
9635 tree t;
9636 tree non_primary_binfo;
9638 /* If there are no virtual baseclasses, then there is nothing to
9639 do. */
9645 /* We might be a primary base class. Go up the inheritance hierarchy
9646 until we find the most derived class of which we are a primary base:
9647 it is the offset of that which we need to use. */
9650 {
9651 tree b;
9653 /* If we have reached a virtual base, then it must be a primary
9654 base (possibly multi-level) of vid->binfo, or we wouldn't
9655 have called build_vcall_and_vbase_vtbl_entries for it. But it
9656 might be a lost primary, so just skip down to vid->binfo. */
9658 {
9661 }
9667 }
9669 /* Go through the virtual bases, adding the offsets. */
9671 vbase;
9673 {
9674 tree b;
9675 tree delta;
9680 /* Find the instance of this virtual base in the complete
9681 object. */
9684 /* If we've already got an offset for this virtual base, we
9685 don't need another one. */
9690 /* Figure out where we can find this vbase offset. */
9699 /* The vbase offset had better be the same. */
9702 /* The next vbase will come at a more negative offset. */
9706 /* The initializer is the delta from BINFO to this virtual base.
9707 The vbase offsets go in reverse inheritance-graph order, and
9708 we are walking in inheritance graph order so these end up in
9709 the right order. */
9716 }
9717 }
9719 /* Adds the initializers for the vcall offset entries in the vtable
9720 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9721 to VID->INITS. */
9723 static void
9725 {
9726 /* We only need these entries if this base is a virtual base. We
9727 compute the indices -- but do not add to the vtable -- when
9728 building the main vtable for a class. */
9731 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9732 correspond to VID->DERIVED), we are building a primary
9733 construction virtual table. Since this is a primary
9734 virtual table, we do not need the vcall offsets for
9735 BINFO. */
9737 {
9738 /* We need a vcall offset for each of the virtual functions in this
9739 vtable. For example:
9741 class A { virtual void f (); };
9742 class B1 : virtual public A { virtual void f (); };
9743 class B2 : virtual public A { virtual void f (); };
9744 class C: public B1, public B2 { virtual void f (); };
9746 A C object has a primary base of B1, which has a primary base of A. A
9747 C also has a secondary base of B2, which no longer has a primary base
9748 of A. So the B2-in-C construction vtable needs a secondary vtable for
9749 A, which will adjust the A* to a B2* to call f. We have no way of
9750 knowing what (or even whether) this offset will be when we define B2,
9751 so we store this "vcall offset" in the A sub-vtable and look it up in
9752 a "virtual thunk" for B2::f.
9754 We need entries for all the functions in our primary vtable and
9755 in our non-virtual bases' secondary vtables. */
9757 /* If we are just computing the vcall indices -- but do not need
9758 the actual entries -- not that. */
9761 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9763 }
9764 }
9766 /* Build vcall offsets, starting with those for BINFO. */
9768 static void
9770 {
9772 tree primary_binfo;
9773 tree base_binfo;
9775 /* Don't walk into virtual bases -- except, of course, for the
9776 virtual base for which we are building vcall offsets. Any
9777 primary virtual base will have already had its offsets generated
9778 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9782 /* If BINFO has a primary base, process it first. */
9787 /* Add BINFO itself to the list. */
9790 /* Scan the non-primary bases of BINFO. */
9794 }
9796 /* Called from build_vcall_offset_vtbl_entries_r. */
9798 static void
9800 {
9801 /* Make entries for the rest of the virtuals. */
9802 tree orig_fn;
9804 /* The ABI requires that the methods be processed in declaration
9805 order. */
9807 orig_fn;
9811 }
9813 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9815 static void
9817 {
9819 tree vcall_offset;
9820 tree derived_entry;
9822 /* If there is already an entry for a function with the same
9823 signature as FN, then we do not need a second vcall offset.
9824 Check the list of functions already present in the derived
9825 class vtable. */
9827 {
9829 /* We only use one vcall offset for virtual destructors,
9830 even though there are two virtual table entries. */
9834 }
9836 /* If we are building these vcall offsets as part of building
9837 the vtable for the most derived class, remember the vcall
9838 offset. */
9840 {
9843 }
9845 /* The next vcall offset will be found at a more negative
9846 offset. */
9850 /* Keep track of this function. */
9854 {
9855 tree base;
9856 tree fn;
9858 /* Find the overriding function. */
9862 else
9863 {
9866 /* The vbase we're working on is a primary base of
9867 vid->binfo. But it might be a lost primary, so its
9868 BINFO_OFFSET might be wrong, so we just use the
9869 BINFO_OFFSET from vid->binfo. */
9875 vcall_offset);
9876 }
9877 /* Add the initializer to the vtable. */
9879 }
9880 }
9882 /* Return vtbl initializers for the RTTI entries corresponding to the
9883 BINFO's vtable. The RTTI entries should indicate the object given
9884 by VID->rtti_binfo. */
9886 static void
9888 {
9889 tree b;
9890 tree t;
9891 tree offset;
9892 tree decl;
9893 tree init;
9897 /* To find the complete object, we will first convert to our most
9898 primary base, and then add the offset in the vtbl to that value. */
9903 /* The second entry is the address of the typeinfo object. */
9906 else
9909 /* Convert the declaration to a type that can be stored in the
9910 vtable. */
9914 /* Add the offset-to-top entry. It comes earlier in the vtable than
9915 the typeinfo entry. Convert the offset to look like a
9916 function pointer, so that we can put it in the vtable. */
9919 }
9921 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9922 accessibility. */
9924 bool
9926 {
9929 }
9931 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9933 bool
9935 {
9939 }
9941 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9942 class between them, if any. */
9944 tree
9946 {
9958 {
9961 }
9965 }