| blob | 31fa4b03136a0b4d187bfbc6f5a93bd1cc1b4fbd |
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 add any missing tags. */
1566 static void
1568 {
1576 /* No need to worry about things local to this TU. */
1589 {
1593 else
1597 }
1600 }
1602 /* Check that DECL has all the ABI tags that are used in parts of its type
1603 that are not reflected in its mangled name. */
1605 void
1607 {
1608 tree t;
1614 /* Make sure that our template has the appropriate tags, since
1615 write_unqualified_name looks for them there. */
1622 }
1624 void
1626 {
1636 {
1639 {
1643 }
1644 }
1646 // If we found some tags on our template arguments, add them to our
1647 // abi_tag attribute.
1649 {
1653 else
1657 }
1660 }
1662 /* Return true, iff class T has a non-virtual destructor that is
1663 accessible from outside the class heirarchy (i.e. is public, or
1664 there's a suitable friend. */
1666 static bool
1668 {
1671 /* An implicitly declared destructor is always public. And,
1672 if it were virtual, we would have created it by now. */
1687 }
1689 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1690 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1691 properties of the bases. */
1693 static void
1697 {
1701 tree base_binfo;
1702 tree binfo;
1712 {
1721 /* If any base class is non-literal, so is the derived class. */
1725 /* If the base class doesn't have copy constructors or
1726 assignment operators that take const references, then the
1727 derived class cannot have such a member automatically
1728 generated. */
1737 /* A virtual base does not effect nearly emptiness. */
1738 ;
1740 {
1742 /* And if there is more than one nearly empty base, then the
1743 derived class is not nearly empty either. */
1745 else
1746 /* Remember we've seen one. */
1748 }
1750 /* If the base class is not empty or nearly empty, then this
1751 class cannot be nearly empty. */
1754 /* A lot of properties from the bases also apply to the derived
1755 class. */
1772 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1775 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1779 /* A standard-layout class is a class that:
1780 ...
1781 * has no non-standard-layout base classes, */
1784 {
1785 tree basefield;
1786 /* ...has no base classes of the same type as the first non-static
1787 data member... */
1789 && (same_type_ignoring_top_level_qualifiers_p
1792 else
1793 /* ...either has no non-static data members in the most-derived
1794 class and at most one base class with non-static data
1795 members, or has no base classes with non-static data
1796 members */
1800 {
1803 else
1806 }
1807 }
1809 /* Don't bother collecting tm attributes if transactional memory
1810 support is not enabled. */
1812 {
1816 }
1819 }
1821 /* If one of the base classes had TM attributes, and the current class
1822 doesn't define its own, then the current class inherits one. */
1824 {
1827 }
1828 }
1830 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1831 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1832 that have had a nearly-empty virtual primary base stolen by some
1833 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1834 T. */
1836 static void
1838 {
1842 tree base_binfo;
1844 /* Determine the primary bases of our bases. */
1847 {
1850 /* See if we're the non-virtual primary of our inheritance
1851 chain. */
1853 {
1860 /* We are the primary binfo. */
1862 }
1863 /* Determine if we have a virtual primary base, and mark it so.
1864 */
1866 {
1870 /* Someone already claimed this base. */
1872 else
1873 {
1874 tree delta;
1879 /* A virtual binfo might have been copied from within
1880 another hierarchy. As we're about to use it as a
1881 primary base, make sure the offsets match. */
1889 }
1890 }
1891 }
1893 /* First look for a dynamic direct non-virtual base. */
1895 {
1899 {
1902 }
1903 }
1905 /* A "nearly-empty" virtual base class can be the primary base
1906 class, if no non-virtual polymorphic base can be found. Look for
1907 a nearly-empty virtual dynamic base that is not already a primary
1908 base of something in the hierarchy. If there is no such base,
1909 just pick the first nearly-empty virtual base. */
1915 {
1917 {
1918 /* Found one that is not primary. */
1921 }
1923 /* Remember the first candidate. */
1925 }
1927 found:
1928 /* If we've got a primary base, use it. */
1930 {
1935 /* We are stealing a primary base. */
1939 {
1940 tree delta;
1943 /* A virtual binfo might have been copied from within
1944 another hierarchy. As we're about to use it as a primary
1945 base, make sure the offsets match. */
1950 }
1957 }
1958 }
1960 /* Update the variant types of T. */
1962 void
1964 {
1965 tree variants;
1971 variants;
1973 {
1974 /* These fields are in the _TYPE part of the node, not in
1975 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1985 /* Copy whatever these are holding today. */
1988 }
1989 }
1991 /* KLASS is a class that we're applying may_alias to after the body is
1992 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
1993 canonical type(s) will be implicitly updated. */
1995 static void
1997 {
1998 tree t;
2004 }
2006 /* Early variant fixups: we apply attributes at the beginning of the class
2007 definition, and we need to fix up any variants that have already been
2008 made via elaborated-type-specifier so that check_qualified_type works. */
2010 void
2012 {
2013 tree variants;
2027 variants;
2029 {
2030 /* These are the two fields that check_qualified_type looks at and
2031 are affected by attributes. */
2036 else
2041 }
2042 }
2043 \f
2044 /* Set memoizing fields and bits of T (and its variants) for later
2045 use. */
2047 static void
2049 {
2050 /* Fix up variants (if any). */
2054 /* For a class w/o baseclasses, 'finish_struct' has set
2055 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2056 Similarly for a class whose base classes do not have vtables.
2057 When neither of these is true, we might have removed abstract
2058 virtuals (by providing a definition), added some (by declaring
2059 new ones), or redeclared ones from a base class. We need to
2060 recalculate what's really an abstract virtual at this point (by
2061 looking in the vtables). */
2064 /* If this type has a copy constructor or a destructor, force its
2065 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2066 nonzero. This will cause it to be passed by invisible reference
2067 and prevent it from being returned in a register. */
2070 {
2071 tree variants;
2074 {
2077 }
2078 }
2079 }
2081 /* Issue warnings about T having private constructors, but no friends,
2082 and so forth.
2084 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2085 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2086 non-private static member functions. */
2088 static void
2090 {
2093 tree fn;
2096 /* If the class has friends, those entities might create and
2097 access instances, so we should not warn. */
2100 /* We will have warned when the template was declared; there's
2101 no need to warn on every instantiation. */
2103 /* There's no reason to even consider warning about this
2104 class. */
2107 /* We only issue one warning, if more than one applies, because
2108 otherwise, on code like:
2110 class A {
2111 // Oops - forgot `public:'
2112 A();
2113 A(const A&);
2114 ~A();
2115 };
2117 we warn several times about essentially the same problem. */
2119 /* Check to see if all (non-constructor, non-destructor) member
2120 functions are private. (Since there are no friends or
2121 non-private statics, we can't ever call any of the private member
2122 functions.) */
2124 /* We're not interested in compiler-generated methods; they don't
2125 provide any way to call private members. */
2127 {
2129 {
2131 /* A non-private static member function is just like a
2132 friend; it can create and invoke private member
2133 functions, and be accessed without a class
2134 instance. */
2138 /* Keep searching for a static member function. */
2139 }
2142 }
2145 {
2146 /* There are no non-private methods, and there's at least one
2147 private member function that isn't a constructor or
2148 destructor. (If all the private members are
2149 constructors/destructors we want to use the code below that
2150 issues error messages specifically referring to
2151 constructors/destructors.) */
2157 {
2160 }
2162 {
2166 }
2167 }
2169 /* Even if some of the member functions are non-private, the class
2170 won't be useful for much if all the constructors or destructors
2171 are private: such an object can never be created or destroyed. */
2174 {
2177 t);
2179 }
2181 /* Warn about classes that have private constructors and no friends. */
2183 /* Implicitly generated constructors are always public. */
2186 {
2189 /* If a non-template class does not define a copy
2190 constructor, one is defined for it, enabling it to avoid
2191 this warning. For a template class, this does not
2192 happen, and so we would normally get a warning on:
2194 template <class T> class C { private: C(); };
2196 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2197 complete non-template or fully instantiated classes have this
2198 flag set. */
2201 else
2203 {
2205 /* Ideally, we wouldn't count copy constructors (or, in
2206 fact, any constructor that takes an argument of the
2207 class type as a parameter) because such things cannot
2208 be used to construct an instance of the class unless
2209 you already have one. But, for now at least, we're
2210 more generous. */
2212 {
2215 }
2216 }
2219 {
2222 t);
2224 }
2225 }
2226 }
2229 gt_pointer_operator new_value;
2233 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2235 static int
2237 {
2250 }
2252 /* This routine compares two fields like method_name_cmp but using the
2253 pointer operator in resort_field_decl_data. */
2255 static int
2257 {
2266 {
2273 }
2275 }
2277 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2279 void
2282 gt_pointer_operator new_value,
2284 {
2288 tree fn;
2290 /* The type conversion ops have to live at the front of the vec, so we
2291 can't sort them. */
2299 {
2303 resort_method_name_cmp);
2304 }
2305 }
2307 /* Warn about duplicate methods in fn_fields.
2309 Sort methods that are not special (i.e., constructors, destructors,
2310 and type conversion operators) so that we can find them faster in
2311 search. */
2313 static void
2315 {
2316 tree fn_fields;
2326 /* Clear DECL_IN_AGGR_P for all functions. */
2331 /* Issue warnings about private constructors and such. If there are
2332 no methods, then some public defaults are generated. */
2335 /* The type conversion ops have to live at the front of the vec, so we
2336 can't sort them. */
2345 }
2347 /* Make BINFO's vtable have N entries, including RTTI entries,
2348 vbase and vcall offsets, etc. Set its type and call the back end
2349 to lay it out. */
2351 static void
2353 {
2354 tree atype;
2355 tree vtable;
2360 /* We may have to grow the vtable. */
2363 {
2367 }
2368 }
2370 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2371 have the same signature. */
2373 int
2375 {
2376 /* One destructor overrides another if they are the same kind of
2377 destructor. */
2381 /* But a non-destructor never overrides a destructor, nor vice
2382 versa, nor do different kinds of destructors override
2383 one-another. For example, a complete object destructor does not
2384 override a deleting destructor. */
2393 {
2401 }
2403 }
2405 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2406 subobject. */
2408 static bool
2410 {
2411 tree probe;
2414 {
2418 /* If we meet a virtual base, we can't follow the inheritance
2419 any more. See if the complete type of DERIVED contains
2420 such a virtual base. */
2423 }
2425 }
2428 /* The function for which we are trying to find a final overrider. */
2429 tree fn;
2430 /* The base class in which the function was declared. */
2431 tree declaring_base;
2432 /* The candidate overriders. */
2433 tree candidates;
2434 /* Path to most derived. */
2436 };
2438 /* Add the overrider along the current path to FFOD->CANDIDATES.
2439 Returns true if an overrider was found; false otherwise. */
2441 static bool
2445 {
2446 tree method;
2448 /* If BINFO is not the most derived type, try a more derived class.
2449 A definition there will overrider a definition here. */
2451 {
2452 depth--;
2456 }
2460 {
2463 /* Remove any candidates overridden by this new function. */
2465 {
2466 /* If *CANDIDATE overrides METHOD, then METHOD
2467 cannot override anything else on the list. */
2470 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2473 else
2475 }
2477 /* Add the new function. */
2480 }
2483 }
2485 /* Called from find_final_overrider via dfs_walk. */
2487 static tree
2489 {
2497 }
2499 static tree
2501 {
2506 }
2508 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2509 FN and whose TREE_VALUE is the binfo for the base where the
2510 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2511 DERIVED) is the base object in which FN is declared. */
2513 static tree
2515 {
2516 find_final_overrider_data ffod;
2518 /* Getting this right is a little tricky. This is valid:
2520 struct S { virtual void f (); };
2521 struct T { virtual void f (); };
2522 struct U : public S, public T { };
2524 even though calling `f' in `U' is ambiguous. But,
2526 struct R { virtual void f(); };
2527 struct S : virtual public R { virtual void f (); };
2528 struct T : virtual public R { virtual void f (); };
2529 struct U : public S, public T { };
2531 is not -- there's no way to decide whether to put `S::f' or
2532 `T::f' in the vtable for `R'.
2534 The solution is to look at all paths to BINFO. If we find
2535 different overriders along any two, then there is a problem. */
2539 /* Determine the depth of the hierarchy. */
2550 /* If there was no winner, issue an error message. */
2555 }
2557 /* Return the index of the vcall offset for FN when TYPE is used as a
2558 virtual base. */
2560 static tree
2562 {
2564 tree_pair_p p;
2572 /* There should always be an appropriate index. */
2574 }
2576 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2577 dominated by T. FN is the old function; VIRTUALS points to the
2578 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2579 of that entry in the list. */
2581 static void
2584 {
2585 tree b;
2586 tree overrider;
2587 tree delta;
2588 tree virtual_base;
2589 tree first_defn;
2595 /* Find the nearest primary base (possibly binfo itself) which defines
2596 this function; this is the class the caller will convert to when
2597 calling FN through BINFO. */
2599 {
2604 /* The nearest definition is from a lost primary. */
2607 }
2610 /* Find the final overrider. */
2613 {
2616 }
2619 /* Check for adjusting covariant return types. */
2627 /* If the overrider is invalid, don't even try. */
2629 {
2630 /* If FN is a covariant thunk, we must figure out the adjustment
2631 to the final base FN was converting to. As OVERRIDER_TARGET might
2632 also be converting to the return type of FN, we have to
2633 combine the two conversions here. */
2640 {
2644 }
2645 else
2649 /* Find the equivalent binfo within the return type of the
2650 overriding function. We will want the vbase offset from
2651 there. */
2653 over_return);
2656 {
2657 /* There was no existing virtual thunk (which takes
2658 precedence). So find the binfo of the base function's
2659 return type within the overriding function's return type.
2660 Fortunately we know the covariancy is valid (it
2661 has already been checked), so we can just iterate along
2662 the binfos, which have been chained in inheritance graph
2663 order. Of course it is lame that we have to repeat the
2664 search here anyway -- we should really be caching pieces
2665 of the vtable and avoiding this repeated work. */
2668 /* Find the base binfo within the overriding function's
2669 return type. We will always find a thunk_binfo, except
2670 when the covariancy is invalid (which we will have
2671 already diagnosed). */
2674 thunk_binfo;
2680 /* See if virtual inheritance is involved. */
2682 virtual_offset;
2689 {
2693 {
2694 /* We convert via virtual base. Adjust the fixed
2695 offset to be from there. */
2696 offset =
2700 }
2702 /* There was an existing fixed offset, this must be
2703 from the base just converted to, and the base the
2704 FN was thunking to. */
2706 else
2708 }
2709 }
2712 /* Replace the overriding function with a covariant thunk. We
2713 will emit the overriding function in its own slot as
2714 well. */
2717 }
2718 else
2722 /* If we need a covariant thunk, then we may need to adjust first_defn.
2723 The ABI specifies that the thunks emitted with a function are
2724 determined by which bases the function overrides, so we need to be
2725 sure that we're using a thunk for some overridden base; even if we
2726 know that the necessary this adjustment is zero, there may not be an
2727 appropriate zero-this-adjusment thunk for us to use since thunks for
2728 overriding virtual bases always use the vcall offset.
2730 Furthermore, just choosing any base that overrides this function isn't
2731 quite right, as this slot won't be used for calls through a type that
2732 puts a covariant thunk here. Calling the function through such a type
2733 will use a different slot, and that slot is the one that determines
2734 the thunk emitted for that base.
2736 So, keep looking until we find the base that we're really overriding
2737 in this slot: the nearest primary base that doesn't use a covariant
2738 thunk in this slot. */
2740 {
2742 /* We already know that the overrider needs a covariant thunk. */
2745 {
2752 }
2754 }
2756 /* Assume that we will produce a thunk that convert all the way to
2757 the final overrider, and not to an intermediate virtual base. */
2760 /* See if we can convert to an intermediate virtual base first, and then
2761 use the vcall offset located there to finish the conversion. */
2763 {
2764 /* If we find the final overrider, then we can stop
2765 walking. */
2770 /* If we find a virtual base, and we haven't yet found the
2771 overrider, then there is a virtual base between the
2772 declaring base (first_defn) and the final overrider. */
2774 {
2777 }
2778 }
2780 /* Compute the constant adjustment to the `this' pointer. The
2781 `this' pointer, when this function is called, will point at BINFO
2782 (or one of its primary bases, which are at the same offset). */
2784 /* The `this' pointer needs to be adjusted from the declaration to
2785 the nearest virtual base. */
2790 /* If the nearest definition is in a lost primary, we don't need an
2791 entry in our vtable. Except possibly in a constructor vtable,
2792 if we happen to get our primary back. In that case, the offset
2793 will be zero, as it will be a primary base. */
2795 else
2796 /* The `this' pointer needs to be adjusted from pointing to
2797 BINFO to pointing at the base where the final overrider
2798 appears. */
2809 else
2813 }
2815 /* Called from modify_all_vtables via dfs_walk. */
2817 static tree
2819 {
2821 tree virtuals;
2822 tree old_virtuals;
2826 /* A base without a vtable needs no modification, and its bases
2827 are uninteresting. */
2832 /* Don't do the primary vtable, if it's new. */
2836 /* There's no need to modify the vtable for a non-virtual primary
2837 base; we're not going to use that vtable anyhow. We do still
2838 need to do this for virtual primary bases, as they could become
2839 non-primary in a construction vtable. */
2844 /* Now, go through each of the virtual functions in the virtual
2845 function table for BINFO. Find the final overrider, and update
2846 the BINFO_VIRTUALS list appropriately. */
2849 virtuals;
2853 binfo,
2858 }
2860 /* Update all of the primary and secondary vtables for T. Create new
2861 vtables as required, and initialize their RTTI information. Each
2862 of the functions in VIRTUALS is declared in T and may override a
2863 virtual function from a base class; find and modify the appropriate
2864 entries to point to the overriding functions. Returns a list, in
2865 declaration order, of the virtual functions that are declared in T,
2866 but do not appear in the primary base class vtable, and which
2867 should therefore be appended to the end of the vtable for T. */
2869 static tree
2871 {
2875 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2879 /* Update all of the vtables. */
2882 /* Add virtual functions not already in our primary vtable. These
2883 will be both those introduced by this class, and those overridden
2884 from secondary bases. It does not include virtuals merely
2885 inherited from secondary bases. */
2887 {
2892 {
2893 /* We don't need to adjust the `this' pointer when
2894 calling this function. */
2898 /* This is a function not already in our vtable. Keep it. */
2900 }
2901 else
2902 /* We've already got an entry for this function. Skip it. */
2904 }
2907 }
2909 /* Get the base virtual function declarations in T that have the
2910 indicated NAME. */
2912 static void
2914 {
2915 tree methods;
2919 /* Find virtual functions in T with the indicated NAME. */
2924 methods;
2926 {
2931 {
2934 }
2935 }
2941 {
2944 }
2945 }
2947 /* If this declaration supersedes the declaration of
2948 a method declared virtual in the base class, then
2949 mark this field as being virtual as well. */
2951 void
2953 {
2956 /* In [temp.mem] we have:
2958 A specialization of a member function template does not
2959 override a virtual function from a base class. */
2966 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2967 the error_mark_node so that we know it is an overriding
2968 function. */
2969 {
2976 }
2979 {
2985 }
2990 }
2992 /* Warn about hidden virtual functions that are not overridden in t.
2993 We know that constructors and destructors don't apply. */
2995 static void
2997 {
2999 tree fns;
3002 /* We go through each separately named virtual function. */
3006 {
3007 tree fn;
3008 tree name;
3009 tree fndecl;
3010 tree base_binfo;
3011 tree binfo;
3014 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
3015 have the same name. Figure out what name that is. */
3017 /* There are no possibly hidden functions yet. */
3019 /* Iterate through all of the base classes looking for possibly
3020 hidden functions. */
3023 {
3026 }
3028 /* If there are no functions to hide, continue. */
3032 /* Remove any overridden functions. */
3034 {
3038 {
3039 /* If the method from the base class has the same
3040 signature as the method from the derived class, it
3041 has been overridden. */
3046 }
3047 }
3049 /* Now give a warning for all base functions without overriders,
3050 as they are hidden. */
3052 tree base_fndecl;
3055 {
3056 /* Here we know it is a hider, and no overrider exists. */
3058 OPT_Woverloaded_virtual,
3062 }
3063 }
3064 }
3066 /* Recursive helper for finish_struct_anon. */
3068 static void
3070 {
3074 {
3075 /* We're generally only interested in entities the user
3076 declared, but we also find nested classes by noticing
3077 the TYPE_DECL that we create implicitly. You're
3078 allowed to put one anonymous union inside another,
3079 though, so we explicitly tolerate that. We use
3080 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
3081 we also allow unnamed types used for defining fields. */
3088 {
3089 /* We already complained about static data members in
3090 finish_static_data_member_decl. */
3092 {
3095 "%q#D invalid; an anonymous union can "
3097 else
3099 "%q#D invalid; an anonymous struct can "
3101 }
3103 }
3106 {
3108 {
3112 else
3115 }
3117 {
3121 else
3124 }
3125 }
3130 /* Recurse into the anonymous aggregates to handle correctly
3131 access control (c++/24926):
3133 class A {
3134 union {
3135 union {
3136 int i;
3137 };
3138 };
3139 };
3141 int j=A().i; */
3145 }
3146 }
3148 /* Check for things that are invalid. There are probably plenty of other
3149 things we should check for also. */
3151 static void
3153 {
3155 {
3164 }
3165 }
3167 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3168 will be used later during class template instantiation.
3169 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3170 a non-static member data (FIELD_DECL), a member function
3171 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3172 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3173 When FRIEND_P is nonzero, T is either a friend class
3174 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3175 (FUNCTION_DECL, TEMPLATE_DECL). */
3177 void
3179 {
3180 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3185 }
3187 /* This function is called from declare_virt_assop_and_dtor via
3188 dfs_walk_all.
3190 DATA is a type that direcly or indirectly inherits the base
3191 represented by BINFO. If BINFO contains a virtual assignment [copy
3192 assignment or move assigment] operator or a virtual constructor,
3193 declare that function in DATA if it hasn't been already declared. */
3195 static tree
3197 {
3205 /* A base without a vtable needs no modification, and its bases
3206 are uninteresting. */
3210 /* If this is a primary base, then we have already looked at the
3211 virtual functions of its vtable. */
3215 {
3219 {
3224 }
3228 }
3231 }
3233 /* If the class type T has a direct or indirect base that contains a
3234 virtual assignment operator or a virtual destructor, declare that
3235 function in T if it hasn't been already declared. */
3237 static void
3239 {
3247 dfs_declare_virt_assop_and_dtor,
3249 }
3251 /* Declare the inheriting constructor for class T inherited from base
3252 constructor CTOR with the parameter array PARMS of size NPARMS. */
3254 static void
3256 {
3257 /* We don't declare an inheriting ctor that would be a default,
3258 copy or move ctor for derived or base. */
3263 {
3267 }
3276 {
3279 }
3280 }
3282 /* Declare all the inheriting constructors for class T inherited from base
3283 constructor CTOR. */
3285 static void
3287 {
3293 {
3297 }
3300 {
3304 }
3305 }
3307 /* Create default constructors, assignment operators, and so forth for
3308 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3309 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3310 the class cannot have a default constructor, copy constructor
3311 taking a const reference argument, or an assignment operator taking
3312 a const reference, respectively. */
3314 static void
3318 {
3326 /* Destructor. */
3328 {
3329 /* In general, we create destructors lazily. */
3334 /* But if this is a Java class, any non-trivial destructor is
3335 invalid, even if compiler-generated. Therefore, if the
3336 destructor is non-trivial we create it now. */
3338 }
3340 /* [class.ctor]
3342 If there is no user-declared constructor for a class, a default
3343 constructor is implicitly declared. */
3345 {
3350 /* Don't force the declaration to get a hard answer; if the
3351 definition would have made the class non-literal, it will still be
3352 non-literal because of the base or member in question, and that
3353 gives a better diagnostic. */
3355 }
3357 /* [class.ctor]
3359 If a class definition does not explicitly declare a copy
3360 constructor, one is declared implicitly. */
3362 {
3368 }
3370 /* If there is no assignment operator, one will be created if and
3371 when it is needed. For now, just record whether or not the type
3372 of the parameter to the assignment operator will be a const or
3373 non-const reference. */
3375 {
3381 }
3383 /* We can't be lazy about declaring functions that might override
3384 a virtual function from a base class. */
3388 {
3392 {
3393 /* declare, then remove the decl */
3402 }
3403 else
3405 }
3406 }
3408 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3409 count the number of fields in TYPE, including anonymous union
3410 members. */
3412 static int
3414 {
3415 tree x;
3418 {
3421 else
3423 }
3425 }
3427 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3428 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3429 elts, starting at offset IDX. */
3431 static int
3433 {
3434 tree x;
3436 {
3439 else
3441 }
3443 }
3445 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3446 starting at offset IDX. */
3448 static int
3452 {
3453 tree values;
3457 }
3459 /* FIELD is a bit-field. We are finishing the processing for its
3460 enclosing type. Issue any appropriate messages and set appropriate
3461 flags. Returns false if an error has been diagnosed. */
3463 static bool
3465 {
3467 tree w;
3469 /* Extract the declared width of the bitfield, which has been
3470 temporarily stashed in DECL_INITIAL. */
3473 /* Remove the bit-field width indicator so that the rest of the
3474 compiler does not treat that value as an initializer. */
3477 /* Detect invalid bit-field type. */
3479 {
3482 }
3483 else
3484 {
3486 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3489 /* detect invalid field size. */
3495 {
3498 }
3500 {
3503 }
3505 {
3508 }
3523 }
3526 {
3530 }
3531 else
3532 {
3533 /* Non-bit-fields are aligned for their type. */
3537 }
3538 }
3540 /* FIELD is a non bit-field. We are finishing the processing for its
3541 enclosing type T. Issue any appropriate messages and set appropriate
3542 flags. */
3544 static bool
3546 tree t,
3549 {
3553 /* In C++98 an anonymous union cannot contain any fields which would change
3554 the settings of CANT_HAVE_CONST_CTOR and friends. */
3556 ;
3557 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3558 structs. So, we recurse through their fields here. */
3560 {
3565 cant_have_const_ctor,
3566 no_const_asn_ref);
3567 }
3568 /* Check members with class type for constructors, destructors,
3569 etc. */
3571 {
3572 /* Never let anything with uninheritable virtuals
3573 make it through without complaint. */
3577 {
3582 field);
3587 field);
3589 {
3593 }
3594 }
3595 else
3596 {
3609 }
3618 }
3623 /* `build_class_init_list' does not recognize
3624 non-FIELD_DECLs. */
3628 }
3630 /* Check the data members (both static and non-static), class-scoped
3631 typedefs, etc., appearing in the declaration of T. Issue
3632 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3633 declaration order) of access declarations; each TREE_VALUE in this
3634 list is a USING_DECL.
3636 In addition, set the following flags:
3638 EMPTY_P
3639 The class is empty, i.e., contains no non-static data members.
3641 CANT_HAVE_CONST_CTOR_P
3642 This class cannot have an implicitly generated copy constructor
3643 taking a const reference.
3645 CANT_HAVE_CONST_ASN_REF
3646 This class cannot have an implicitly generated assignment
3647 operator taking a const reference.
3649 All of these flags should be initialized before calling this
3650 function.
3652 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3653 fields can be added by adding to this chain. */
3655 static void
3659 {
3667 /* Assume there are no access declarations. */
3669 /* Assume this class has no pointer members. */
3671 /* Assume none of the members of this class have default
3672 initializations. */
3676 {
3684 {
3685 /* Save the access declarations for our caller. */
3688 }
3694 /* If we've gotten this far, it's a data member, possibly static,
3695 or an enumerator. */
3699 /* When this goes into scope, it will be a non-local reference. */
3704 {
3705 /* [class.union] (C++98)
3707 If a union contains a static data member, or a member of
3708 reference type, the program is ill-formed.
3710 In C++11 this limitation doesn't exist anymore. */
3712 {
3716 }
3718 {
3722 }
3723 }
3725 /* Perform error checking that did not get done in
3726 grokdeclarator. */
3728 {
3732 }
3734 {
3738 }
3746 /* Now it can only be a FIELD_DECL. */
3751 /* If at least one non-static data member is non-literal, the whole
3752 class becomes non-literal. Per Core/1453, volatile non-static
3753 data members and base classes are also not allowed.
3754 Note: if the type is incomplete we will complain later on. */
3759 /* A standard-layout class is a class that:
3760 ...
3761 has the same access control (Clause 11) for all non-static data members,
3762 ... */
3769 /* If this is of reference type, check if it needs an init. */
3771 {
3777 {
3778 /* ARM $12.6.2: [A member initializer list] (or, for an
3779 aggregate, initialization by a brace-enclosed list) is the
3780 only way to initialize nonstatic const and reference
3781 members. */
3784 }
3785 }
3790 {
3792 {
3793 warning_at
3796 x);
3798 }
3802 }
3805 /* We don't treat zero-width bitfields as making a class
3806 non-empty. */
3807 ;
3808 else
3809 {
3810 /* The class is non-empty. */
3812 /* The class is not even nearly empty. */
3814 /* If one of the data members contains an empty class,
3815 so does T. */
3819 }
3821 /* This is used by -Weffc++ (see below). Warn only for pointers
3822 to members which might hold dynamic memory. So do not warn
3823 for pointers to functions or pointers to members. */
3829 {
3834 }
3840 {
3842 {
3846 }
3848 {
3852 }
3853 }
3856 /* DR 148 now allows pointers to members (which are POD themselves),
3857 to be allowed in POD structs. */
3866 /* We set DECL_C_BIT_FIELD in grokbitfield.
3867 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3870 cant_have_const_ctor_p,
3871 no_const_asn_ref_p))
3872 {
3877 }
3879 /* Now that we've removed bit-field widths from DECL_INITIAL,
3880 anything left in DECL_INITIAL is an NSDMI that makes the class
3881 non-aggregate in C++11. */
3885 /* If any field is const, the structure type is pseudo-const. */
3887 {
3892 {
3893 /* ARM $12.6.2: [A member initializer list] (or, for an
3894 aggregate, initialization by a brace-enclosed list) is the
3895 only way to initialize nonstatic const and reference
3896 members. */
3899 }
3900 }
3901 /* A field that is pseudo-const makes the structure likewise. */
3903 {
3908 }
3910 /* Core issue 80: A nonstatic data member is required to have a
3911 different name from the class iff the class has a
3912 user-declared constructor. */
3917 }
3919 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3920 it should also define a copy constructor and an assignment operator to
3921 implement the correct copy semantic (deep vs shallow, etc.). As it is
3922 not feasible to check whether the constructors do allocate dynamic memory
3923 and store it within members, we approximate the warning like this:
3925 -- Warn only if there are members which are pointers
3926 -- Warn only if there is a non-trivial constructor (otherwise,
3927 there cannot be memory allocated).
3928 -- Warn only if there is a non-trivial destructor. We assume that the
3929 user at least implemented the cleanup correctly, and a destructor
3930 is needed to free dynamic memory.
3932 This seems enough for practical purposes. */
3934 && has_pointers
3938 {
3942 {
3947 }
3951 }
3953 /* Non-static data member initializers make the default constructor
3954 non-trivial. */
3956 {
3959 }
3961 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3965 /* Check anonymous struct/anonymous union fields. */
3968 /* We've built up the list of access declarations in reverse order.
3969 Fix that now. */
3971 }
3973 /* If TYPE is an empty class type, records its OFFSET in the table of
3974 OFFSETS. */
3976 static int
3978 {
3979 splay_tree_node n;
3984 /* Record the location of this empty object in OFFSETS. */
3992 type,
3996 }
3998 /* Returns nonzero if TYPE is an empty class type and there is
3999 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
4001 static int
4003 {
4004 splay_tree_node n;
4005 tree t;
4010 /* Record the location of this empty object in OFFSETS. */
4020 }
4022 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
4023 F for every subobject, passing it the type, offset, and table of
4024 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
4025 be traversed.
4027 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
4028 than MAX_OFFSET will not be walked.
4030 If F returns a nonzero value, the traversal ceases, and that value
4031 is returned. Otherwise, returns zero. */
4033 static int
4035 subobject_offset_fn f,
4036 tree offset,
4037 splay_tree offsets,
4038 tree max_offset,
4040 {
4044 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
4045 stop. */
4053 {
4056 }
4059 {
4060 tree field;
4061 tree binfo;
4064 /* Avoid recursing into objects that are not interesting. */
4068 /* Record the location of TYPE. */
4073 /* Iterate through the direct base classes of TYPE. */
4077 {
4078 tree binfo_offset;
4083 tree orig_binfo;
4084 /* We cannot rely on BINFO_OFFSET being set for the base
4085 class yet, but the offsets for direct non-virtual
4086 bases can be calculated by going back to the TYPE. */
4089 offset,
4093 f,
4094 binfo_offset,
4095 offsets,
4096 max_offset,
4100 }
4103 {
4107 /* Iterate through the virtual base classes of TYPE. In G++
4108 3.2, we included virtual bases in the direct base class
4109 loop above, which results in incorrect results; the
4110 correct offsets for virtual bases are only known when
4111 working with the most derived type. */
4115 {
4117 f,
4119 offset,
4121 offsets,
4122 max_offset,
4126 }
4127 else
4128 {
4129 /* We still have to walk the primary base, if it is
4130 virtual. (If it is non-virtual, then it was walked
4131 above.) */
4137 {
4138 r = (walk_subobject_offsets
4143 }
4144 }
4145 }
4147 /* Iterate through the fields of TYPE. */
4152 {
4153 tree field_offset;
4158 f,
4160 offset,
4161 field_offset),
4162 offsets,
4163 max_offset,
4167 }
4168 }
4170 {
4173 tree index;
4175 /* Avoid recursing into objects that are not interesting. */
4181 /* Step through each of the elements in the array. */
4185 {
4187 f,
4188 offset,
4189 offsets,
4190 max_offset,
4196 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4197 there's no point in iterating through the remaining
4198 elements of the array. */
4201 }
4202 }
4205 }
4207 /* Record all of the empty subobjects of TYPE (either a type or a
4208 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4209 is being placed at OFFSET; otherwise, it is a base class that is
4210 being placed at OFFSET. */
4212 static void
4214 tree offset,
4215 splay_tree offsets,
4217 {
4218 tree max_offset;
4219 /* If recording subobjects for a non-static data member or a
4220 non-empty base class , we do not need to record offsets beyond
4221 the size of the biggest empty class. Additional data members
4222 will go at the end of the class. Additional base classes will go
4223 either at offset zero (if empty, in which case they cannot
4224 overlap with offsets past the size of the biggest empty class) or
4225 at the end of the class.
4227 However, if we are placing an empty base class, then we must record
4228 all offsets, as either the empty class is at offset zero (where
4229 other empty classes might later be placed) or at the end of the
4230 class (where other objects might then be placed, so other empty
4231 subobjects might later overlap). */
4235 else
4239 }
4241 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4242 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4243 virtual bases of TYPE are examined. */
4245 static int
4247 tree offset,
4248 splay_tree offsets,
4250 {
4251 splay_tree_node max_node;
4253 /* Get the node in OFFSETS that indicates the maximum offset where
4254 an empty subobject is located. */
4256 /* If there aren't any empty subobjects, then there's no point in
4257 performing this check. */
4263 vbases_p);
4264 }
4266 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4267 non-static data member of the type indicated by RLI. BINFO is the
4268 binfo corresponding to the base subobject, OFFSETS maps offsets to
4269 types already located at those offsets. This function determines
4270 the position of the DECL. */
4272 static void
4274 tree decl,
4275 tree binfo,
4276 splay_tree offsets)
4277 {
4280 tree type;
4283 {
4284 /* For the purposes of determining layout conflicts, we want to
4285 use the class type of BINFO; TREE_TYPE (DECL) will be the
4286 CLASSTYPE_AS_BASE version, which does not contain entries for
4287 zero-sized bases. */
4290 }
4291 else
4292 {
4295 }
4297 /* Try to place the field. It may take more than one try if we have
4298 a hard time placing the field without putting two objects of the
4299 same type at the same address. */
4301 {
4304 /* Place this field. */
4308 /* We have to check to see whether or not there is already
4309 something of the same type at the offset we're about to use.
4310 For example, consider:
4312 struct S {};
4313 struct T : public S { int i; };
4314 struct U : public S, public T {};
4316 Here, we put S at offset zero in U. Then, we can't put T at
4317 offset zero -- its S component would be at the same address
4318 as the S we already allocated. So, we have to skip ahead.
4319 Since all data members, including those whose type is an
4320 empty class, have nonzero size, any overlap can happen only
4321 with a direct or indirect base-class -- it can't happen with
4322 a data member. */
4323 /* In a union, overlap is permitted; all members are placed at
4324 offset zero. */
4329 {
4330 /* Strip off the size allocated to this field. That puts us
4331 at the first place we could have put the field with
4332 proper alignment. */
4335 /* Bump up by the alignment required for the type. */
4336 rli->bitpos
4342 }
4345 {
4346 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4347 the offset wasn't aligned like a pointer when we started to
4348 layout this field, that affects its position. */
4351 {
4354 "alignment of %qD increased in -fabi-version=9 "
4356 else
4359 }
4361 }
4362 else
4363 /* There was no conflict. We're done laying out this field. */
4365 }
4367 /* Now that we know where it will be placed, update its
4368 BINFO_OFFSET. */
4370 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4371 this point because their BINFO_OFFSET is copied from another
4372 hierarchy. Therefore, we may not need to add the entire
4373 OFFSET. */
4379 }
4381 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4383 static int
4385 tree offset,
4387 {
4389 }
4391 /* Layout the empty base BINFO. EOC indicates the byte currently just
4392 past the end of the class, and should be correctly aligned for a
4393 class of the type indicated by BINFO; OFFSETS gives the offsets of
4394 the empty bases allocated so far. T is the most derived
4395 type. Return nonzero iff we added it at the end. */
4397 static bool
4400 {
4401 tree alignment;
4405 /* This routine should only be used for empty classes. */
4410 propagate_binfo_offsets
4414 /* This is an empty base class. We first try to put it at offset
4415 zero. */
4418 offsets,
4420 {
4421 /* That didn't work. Now, we move forward from the next
4422 available spot in the class. */
4426 {
4429 offsets,
4431 /* We finally found a spot where there's no overlap. */
4434 /* There's overlap here, too. Bump along to the next spot. */
4436 }
4437 }
4440 {
4445 }
4448 }
4450 /* Layout the base given by BINFO in the class indicated by RLI.
4451 *BASE_ALIGN is a running maximum of the alignments of
4452 any base class. OFFSETS gives the location of empty base
4453 subobjects. T is the most derived type. Return nonzero if the new
4454 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4455 *NEXT_FIELD, unless BINFO is for an empty base class.
4457 Returns the location at which the next field should be inserted. */
4462 {
4467 /* This error is now reported in xref_tag, thus giving better
4468 location information. */
4471 /* Place the base class. */
4473 {
4474 tree decl;
4476 /* The containing class is non-empty because it has a non-empty
4477 base class. */
4480 /* Create the FIELD_DECL. */
4487 {
4495 /* Try to place the field. It may take more than one try if we
4496 have a hard time placing the field without putting two
4497 objects of the same type at the same address. */
4499 /* Add the new FIELD_DECL to the list of fields for T. */
4503 }
4504 }
4505 else
4506 {
4507 tree eoc;
4510 /* On some platforms (ARM), even empty classes will not be
4511 byte-aligned. */
4516 /* A nearly-empty class "has no proper base class that is empty,
4517 not morally virtual, and at an offset other than zero." */
4519 {
4522 /* The check above (used in G++ 3.2) is insufficient because
4523 an empty class placed at offset zero might itself have an
4524 empty base at a nonzero offset. */
4526 empty_base_at_nonzero_offset_p,
4527 size_zero_node,
4532 }
4534 /* We do not create a FIELD_DECL for empty base classes because
4535 it might overlap some other field. We want to be able to
4536 create CONSTRUCTORs for the class by iterating over the
4537 FIELD_DECLs, and the back end does not handle overlapping
4538 FIELD_DECLs. */
4540 /* An empty virtual base causes a class to be non-empty
4541 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4542 here because that was already done when the virtual table
4543 pointer was created. */
4544 }
4546 /* Record the offsets of BINFO and its base subobjects. */
4549 offsets,
4553 }
4555 /* Layout all of the non-virtual base classes. Record empty
4556 subobjects in OFFSETS. T is the most derived type. Return nonzero
4557 if the type cannot be nearly empty. The fields created
4558 corresponding to the base classes will be inserted at
4559 *NEXT_FIELD. */
4561 static void
4564 {
4565 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4566 subobjects. */
4571 /* The primary base class is always allocated first. */
4576 /* Now allocate the rest of the bases. */
4578 {
4579 tree base_binfo;
4583 /* The primary base was already allocated above, so we don't
4584 need to allocate it again here. */
4588 /* Virtual bases are added at the end (a primary virtual base
4589 will have already been added). */
4595 }
4596 }
4598 /* Go through the TYPE_METHODS of T issuing any appropriate
4599 diagnostics, figuring out which methods override which other
4600 methods, and so forth. */
4602 static void
4604 {
4605 tree x;
4608 {
4612 /* The name of the field is the original field name
4613 Save this in auxiliary field for later overloading. */
4615 {
4619 }
4620 /* All user-provided destructors are non-trivial.
4621 Constructors and assignment ops are handled in
4622 grok_special_member_properties. */
4628 "%<transaction_safe_dynamic%> may only be specified for "
4630 }
4631 }
4633 /* FN is a constructor or destructor. Clone the declaration to create
4634 a specialized in-charge or not-in-charge version, as indicated by
4635 NAME. */
4637 static tree
4639 {
4640 tree parms;
4641 tree clone;
4643 /* Copy the function. */
4645 /* Reset the function name. */
4647 /* Remember where this function came from. */
4649 /* Make it easy to find the CLONE given the FN. */
4653 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4655 {
4662 }
4663 else
4664 {
4665 // Clone constraints.
4669 }
4674 /* There's no pending inline data for this function. */
4678 /* The base-class destructor is not virtual. */
4680 {
4684 }
4686 /* If there was an in-charge parameter, drop it from the function
4687 type. */
4689 {
4690 tree basetype;
4691 tree parmtypes;
4692 tree exceptions;
4697 /* Skip the `this' parameter. */
4699 /* Skip the in-charge parameter. */
4701 /* And the VTT parm, in a complete [cd]tor. */
4705 /* If this is subobject constructor or destructor, add the vtt
4706 parameter. */
4710 parmtypes);
4713 exceptions);
4717 }
4719 /* Copy the function parameters. */
4721 /* Remove the in-charge parameter. */
4723 {
4727 }
4728 /* And the VTT parm, in a complete [cd]tor. */
4730 {
4733 else
4734 {
4738 }
4739 }
4742 {
4745 }
4747 /* Create the RTL for this function. */
4752 }
4754 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4755 not invoke this function directly.
4757 For a non-thunk function, returns the address of the slot for storing
4758 the function it is a clone of. Otherwise returns NULL_TREE.
4760 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4761 cloned_function is unset. This is to support the separate
4762 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4763 on a template makes sense, but not the former. */
4765 tree *
4767 {
4775 {
4776 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4779 else
4780 #endif
4782 }
4787 else
4789 }
4791 /* Produce declarations for all appropriate clones of FN. If
4792 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4793 CLASTYPE_METHOD_VEC as well. */
4795 void
4797 {
4798 tree clone;
4800 /* Avoid inappropriate cloning. */
4806 {
4807 /* For each constructor, we need two variants: an in-charge version
4808 and a not-in-charge version. */
4815 }
4816 else
4817 {
4820 /* For each destructor, we need three variants: an in-charge
4821 version, a not-in-charge version, and an in-charge deleting
4822 version. We clone the deleting version first because that
4823 means it will go second on the TYPE_METHODS list -- and that
4824 corresponds to the correct layout order in the virtual
4825 function table.
4827 For a non-virtual destructor, we do not build a deleting
4828 destructor. */
4830 {
4834 }
4841 }
4843 /* Note that this is an abstract function that is never emitted. */
4845 }
4847 /* DECL is an in charge constructor, which is being defined. This will
4848 have had an in class declaration, from whence clones were
4849 declared. An out-of-class definition can specify additional default
4850 arguments. As it is the clones that are involved in overload
4851 resolution, we must propagate the information from the DECL to its
4852 clones. */
4854 void
4856 {
4857 tree clone;
4861 {
4868 /* Skip the 'this' parameter. */
4884 {
4889 {
4890 /* A default parameter has been added. Adjust the
4891 clone's parameters. */
4895 tree type;
4900 {
4903 clone_parms);
4905 }
4908 clone_parms);
4917 }
4918 }
4920 }
4921 }
4923 /* For each of the constructors and destructors in T, create an
4924 in-charge and not-in-charge variant. */
4926 static void
4928 {
4929 tree fns;
4931 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4932 out now. */
4940 }
4942 /* Deduce noexcept for a destructor DTOR. */
4944 void
4946 {
4948 {
4951 }
4952 }
4954 /* For each destructor in T, deduce noexcept:
4956 12.4/3: A declaration of a destructor that does not have an
4957 exception-specification is implicitly considered to have the
4958 same exception-specification as an implicit declaration (15.4). */
4960 static void
4962 {
4963 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4964 out now. */
4970 }
4972 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4973 of TYPE for virtual functions which FNDECL overrides. Return a
4974 mask of the tm attributes found therein. */
4976 static int
4978 {
4980 tree base_binfo;
4984 {
4992 {
4996 else
4999 }
5000 else
5002 }
5005 }
5007 /* Subroutine of set_method_tm_attributes. Handle the checks and
5008 inheritance for one virtual method FNDECL. */
5010 static void
5012 {
5013 tree tm_attr;
5018 /* If FNDECL doesn't actually override anything (i.e. T is the
5019 class that first declares FNDECL virtual), then we're done. */
5026 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
5027 tm_pure must match exactly, otherwise no weakening of
5028 tm_safe > tm_callable > nothing. */
5029 /* ??? The tm_pure attribute didn't make the transition to the
5030 multivendor language spec. */
5032 {
5034 {
5037 }
5038 }
5039 /* If the overridden function is tm_pure, then FNDECL must be. */
5042 /* Look for base class combinations that cannot be satisfied. */
5044 {
5050 }
5051 /* If FNDECL did not declare an attribute, then inherit the most
5052 restrictive one. */
5054 {
5056 }
5057 /* Otherwise validate that we're not weaker than a function
5058 that is being overridden. */
5059 else
5060 {
5064 }
5067 err_override:
5071 }
5073 /* For each of the methods in T, propagate a class-level tm attribute. */
5075 static void
5077 {
5080 /* Don't bother collecting tm attributes if transactional memory
5081 support is not enabled. */
5085 /* Process virtual methods first, as they inherit directly from the
5086 base virtual function and also require validation of new attributes. */
5088 {
5089 tree vchain;
5092 {
5097 }
5098 }
5100 /* If the class doesn't have an attribute, nothing more to do. */
5105 /* Any method that does not yet have a tm attribute inherits
5106 the one from the class. */
5108 {
5111 }
5112 }
5114 /* Returns true iff class T has a user-defined constructor other than
5115 the default constructor. */
5117 bool
5119 {
5120 tree fns;
5126 {
5133 }
5136 }
5138 /* Returns the defaulted constructor if T has one. Otherwise, returns
5139 NULL_TREE. */
5141 tree
5143 {
5150 {
5154 {
5160 }
5161 }
5164 }
5166 /* Returns true iff FN is a user-provided function, i.e. user-declared
5167 and not defaulted at its first declaration; or explicit, private,
5168 protected, or non-const. */
5170 bool
5172 {
5175 else
5179 }
5181 /* Returns true iff class T has a user-provided constructor. */
5183 bool
5185 {
5186 tree fns;
5194 /* This can happen in error cases; avoid crashing. */
5203 }
5205 /* Returns true iff class T has a user-provided or explicit constructor. */
5207 bool
5209 {
5210 tree fns;
5218 /* This can happen in error cases; avoid crashing. */
5223 {
5227 }
5230 }
5232 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5233 declared or explicitly defaulted in the class body) default
5234 constructor. */
5236 bool
5238 {
5239 tree fns;
5247 {
5253 }
5256 }
5258 /* TYPE is being used as a virtual base, and has a non-trivial move
5259 assignment. Return true if this is due to there being a user-provided
5260 move assignment in TYPE or one of its subobjects; if there isn't, then
5261 multiple move assignment can't cause any harm. */
5263 bool
5265 {
5266 /* Does the type itself have a user-provided move assignment operator? */
5270 {
5274 }
5276 /* Do any of its bases? */
5278 tree base_binfo;
5283 /* Or non-static data members? */
5285 {
5290 }
5292 /* Seems not. */
5294 }
5296 /* If default-initialization leaves part of TYPE uninitialized, returns
5297 a DECL for the field or TYPE itself (DR 253). */
5299 tree
5301 {
5312 {
5316 }
5321 {
5325 }
5328 }
5330 /* Returns true iff for class T, a trivial synthesized default constructor
5331 would be constexpr. */
5333 bool
5335 {
5336 /* A defaulted trivial default constructor is constexpr
5337 if there is nothing to initialize. */
5340 }
5342 /* Returns true iff class T has a constexpr default constructor. */
5344 bool
5346 {
5347 tree fns;
5350 {
5351 /* The caller should have stripped an enclosing array. */
5354 }
5356 {
5359 /* Non-trivial, we need to check subobject constructors. */
5361 }
5364 }
5366 /* Returns true iff class T has a constexpr default constructor or has an
5367 implicitly declared default constructor that we can't tell if it's constexpr
5368 without forcing a lazy declaration (which might cause undesired
5369 instantiations). */
5371 bool
5373 {
5376 /* Assume it's constexpr. */
5379 }
5381 /* Returns true iff class TYPE has a virtual destructor. */
5383 bool
5385 {
5386 tree dtor;
5394 }
5396 /* Returns true iff class T has a move constructor. */
5398 bool
5400 {
5401 tree fns;
5404 {
5407 }
5417 }
5419 /* Returns true iff class T has a move assignment operator. */
5421 bool
5423 {
5424 tree fns;
5427 {
5430 }
5438 }
5440 /* Returns true iff class T has a move constructor that was explicitly
5441 declared in the class body. Note that this is different from
5442 "user-provided", which doesn't include functions that are defaulted in
5443 the class. */
5445 bool
5447 {
5448 tree fns;
5457 {
5461 }
5464 }
5466 /* Returns true iff class T has a move assignment operator that was
5467 explicitly declared in the class body. */
5469 bool
5471 {
5472 tree fns;
5479 {
5483 }
5486 }
5488 /* Nonzero if we need to build up a constructor call when initializing an
5489 object of this class, either because it has a user-declared constructor
5490 or because it doesn't have a default constructor (so we need to give an
5491 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5492 what you care about is whether or not an object can be produced by a
5493 constructor (e.g. so we don't set TREE_READONLY on const variables of
5494 such type); use this function when what you care about is whether or not
5495 to try to call a constructor to create an object. The latter case is
5496 the former plus some cases of constructors that cannot be called. */
5498 bool
5500 {
5501 tree inner;
5511 /* A user-declared constructor might be private, and a constructor might
5512 be trivial but deleted. */
5515 {
5520 }
5522 }
5524 /* Like type_build_ctor_call, but for destructors. */
5526 bool
5528 {
5529 tree inner;
5538 /* A user-declared destructor might be private, and a destructor might
5539 be trivial but deleted. */
5542 {
5547 }
5549 }
5551 /* Remove all zero-width bit-fields from T. */
5553 static void
5555 {
5560 {
5563 /* We should not be confused by the fact that grokbitfield
5564 temporarily sets the width of the bit field into
5565 DECL_INITIAL (*fieldsp).
5566 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5567 to that width. */
5571 else
5573 }
5574 }
5576 /* Returns TRUE iff we need a cookie when dynamically allocating an
5577 array whose elements have the indicated class TYPE. */
5579 static bool
5581 {
5582 tree fns;
5587 /* If there's a non-trivial destructor, we need a cookie. In order
5588 to iterate through the array calling the destructor for each
5589 element, we'll have to know how many elements there are. */
5593 /* If the usual deallocation function is a two-argument whose second
5594 argument is of type `size_t', then we have to pass the size of
5595 the array to the deallocation function, so we will need to store
5596 a cookie. */
5600 /* If there are no `operator []' members, or the lookup is
5601 ambiguous, then we don't need a cookie. */
5604 /* Loop through all of the functions. */
5606 {
5607 tree fn;
5608 tree second_parm;
5610 /* Select the current function. */
5612 /* See if this function is a one-argument delete function. If
5613 it is, then it will be the usual deallocation function. */
5617 /* Do not consider this function if its second argument is an
5618 ellipsis. */
5621 /* Otherwise, if we have a two-argument function and the second
5622 argument is `size_t', it will be the usual deallocation
5623 function -- unless there is one-argument function, too. */
5627 }
5630 }
5632 /* Finish computing the `literal type' property of class type T.
5634 At this point, we have already processed base classes and
5635 non-static data members. We need to check whether the copy
5636 constructor is trivial, the destructor is trivial, and there
5637 is a trivial default constructor or at least one constexpr
5638 constructor other than the copy constructor. */
5640 static void
5642 {
5643 tree fn;
5659 {
5662 {
5666 }
5667 }
5668 }
5670 /* T is a non-literal type used in a context which requires a constant
5671 expression. Explain why it isn't literal. */
5673 void
5675 {
5685 /* Already explained. */
5694 {
5696 "default constructor, and has no constexpr constructor that "
5699 {
5700 /* Note that we can't simply call locate_ctor because when the
5701 constructor is deleted it just returns NULL_TREE. */
5702 tree fns;
5704 {
5711 {
5714 else
5717 }
5718 }
5719 }
5720 }
5721 else
5722 {
5726 {
5729 {
5734 }
5735 }
5737 {
5738 tree ftype;
5743 {
5746 field);
5749 }
5753 }
5754 }
5755 }
5757 /* Check the validity of the bases and members declared in T. Add any
5758 implicitly-generated functions (like copy-constructors and
5759 assignment operators). Compute various flag bits (like
5760 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5761 level: i.e., independently of the ABI in use. */
5763 static void
5765 {
5766 /* Nonzero if the implicitly generated copy constructor should take
5767 a non-const reference argument. */
5769 /* Nonzero if the implicitly generated assignment operator
5770 should take a non-const reference argument. */
5772 tree access_decls;
5775 tree fn;
5777 /* By default, we use const reference arguments and generate default
5778 constructors. */
5782 /* Check all the base-classes and set FMEM members to point to arrays
5783 of potential interest. */
5786 /* Deduce noexcept on destructors. This needs to happen after we've set
5787 triviality flags appropriately for our bases. */
5791 /* Check all the method declarations. */
5794 /* Save the initial values of these flags which only indicate whether
5795 or not the class has user-provided functions. As we analyze the
5796 bases and members we can set these flags for other reasons. */
5800 /* Check all the data member declarations. We cannot call
5801 check_field_decls until we have called check_bases check_methods,
5802 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5803 being set appropriately. */
5808 /* A nearly-empty class has to be vptr-containing; a nearly empty
5809 class contains just a vptr. */
5813 /* Do some bookkeeping that will guide the generation of implicitly
5814 declared member functions. */
5817 /* We need to call a constructor for this class if it has a
5818 user-provided constructor, or if the default constructor is going
5819 to initialize the vptr. (This is not an if-and-only-if;
5820 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5821 themselves need constructing.) */
5824 /* [dcl.init.aggr]
5826 An aggregate is an array or a class with no user-provided
5827 constructors ... and no virtual functions.
5829 Again, other conditions for being an aggregate are checked
5830 elsewhere. */
5834 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5835 retain the old definition internally for ABI reasons. */
5844 /* If the only explicitly declared default constructor is user-provided,
5845 set TYPE_HAS_COMPLEX_DFLT. */
5851 /* Warn if a public base of a polymorphic type has an accessible
5852 non-virtual destructor. It is only now that we know the class is
5853 polymorphic. Although a polymorphic base will have a already
5854 been diagnosed during its definition, we warn on use too. */
5856 {
5859 tree base_binfo;
5863 {
5871 basetype);
5872 }
5873 }
5875 /* If the class has no user-declared constructor, but does have
5876 non-static const or reference data members that can never be
5877 initialized, issue a warning. */
5879 /* Classes with user-declared constructors are presumed to
5880 initialize these members. */
5882 /* Aggregates can be initialized with brace-enclosed
5883 initializers. */
5885 {
5886 tree field;
5889 {
5890 tree type;
5907 }
5908 }
5910 /* Synthesize any needed methods. */
5912 cant_have_const_ctor,
5913 no_const_asn_ref);
5915 /* Check defaulted declarations here so we have cant_have_const_ctor
5916 and don't need to worry about clones. */
5919 {
5922 {
5923 bool imp_const_p
5929 /* If the function is defaulted outside the class, we just
5930 give the synthesis error. */
5933 }
5935 }
5938 {
5939 /* "This class type is not an aggregate." */
5941 }
5943 /* Compute the 'literal type' property before we
5944 do anything with non-static member functions. */
5947 /* Create the in-charge and not-in-charge variants of constructors
5948 and destructors. */
5951 /* Process the using-declarations. */
5955 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5958 /* Figure out whether or not we will need a cookie when dynamically
5959 allocating an array of this type. */
5962 }
5964 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5965 accordingly. If a new vfield was created (because T doesn't have a
5966 primary base class), then the newly created field is returned. It
5967 is not added to the TYPE_FIELDS list; it is the caller's
5968 responsibility to do that. Accumulate declared virtual functions
5969 on VIRTUALS_P. */
5971 static tree
5973 {
5974 tree fn;
5976 /* Collect the virtual functions declared in T. */
5981 {
5990 }
5992 /* If we couldn't find an appropriate base class, create a new field
5993 here. Even if there weren't any new virtual functions, we might need a
5994 new virtual function table if we're supposed to include vptrs in
5995 all classes that need them. */
5997 {
5998 /* We build this decl with vtbl_ptr_type_node, which is a
5999 `vtable_entry_type*'. It might seem more precise to use
6000 `vtable_entry_type (*)[N]' where N is the number of virtual
6001 functions. However, that would require the vtable pointer in
6002 base classes to have a different type than the vtable pointer
6003 in derived classes. We could make that happen, but that
6004 still wouldn't solve all the problems. In particular, the
6005 type-based alias analysis code would decide that assignments
6006 to the base class vtable pointer can't alias assignments to
6007 the derived class vtable pointer, since they have different
6008 types. Thus, in a derived class destructor, where the base
6009 class constructor was inlined, we could generate bad code for
6010 setting up the vtable pointer.
6012 Therefore, we use one type for all vtable pointers. We still
6013 use a type-correct type; it's just doesn't indicate the array
6014 bounds. That's better than using `void*' or some such; it's
6015 cleaner, and it let's the alias analysis code know that these
6016 stores cannot alias stores to void*! */
6017 tree field;
6030 /* This class is non-empty. */
6034 }
6037 }
6039 /* Add OFFSET to all base types of BINFO which is a base in the
6040 hierarchy dominated by T.
6042 OFFSET, which is a type offset, is number of bytes. */
6044 static void
6046 {
6048 tree primary_binfo;
6049 tree base_binfo;
6051 /* Update BINFO's offset. */
6056 offset));
6058 /* Find the primary base class. */
6064 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
6065 downwards. */
6067 {
6068 /* Don't do the primary base twice. */
6076 }
6077 }
6079 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6080 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6081 empty subobjects of T. */
6083 static void
6085 {
6086 tree vbase;
6093 /* Find the last field. The artificial fields created for virtual
6094 bases will go after the last extant field to date. */
6099 /* Go through the virtual bases, allocating space for each virtual
6100 base that is not already a primary base class. These are
6101 allocated in inheritance graph order. */
6103 {
6108 {
6109 /* This virtual base is not a primary base of any class in the
6110 hierarchy, so we have to add space for it. */
6113 }
6114 }
6115 }
6117 /* Returns the offset of the byte just past the end of the base class
6118 BINFO. */
6120 static tree
6122 {
6123 tree size;
6128 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6129 allocate some space for it. It cannot have virtual bases, so
6130 TYPE_SIZE_UNIT is fine. */
6132 else
6136 }
6138 /* Returns the offset of the byte just past the end of the base class
6139 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6140 only non-virtual bases are included. */
6142 static tree
6144 {
6147 tree binfo;
6148 tree base_binfo;
6149 tree offset;
6154 {
6164 }
6169 {
6173 }
6176 }
6178 /* Warn about bases of T that are inaccessible because they are
6179 ambiguous. For example:
6181 struct S {};
6182 struct T : public S {};
6183 struct U : public S, public T {};
6185 Here, `(S*) new U' is not allowed because there are two `S'
6186 subobjects of U. */
6188 static void
6190 {
6193 tree basetype;
6194 tree binfo;
6195 tree base_binfo;
6197 /* If there are no repeated bases, nothing can be ambiguous. */
6201 /* Check direct bases. */
6204 {
6210 }
6212 /* Check for ambiguous virtual bases. */
6216 {
6222 }
6223 }
6225 /* Compare two INTEGER_CSTs K1 and K2. */
6227 static int
6229 {
6231 }
6233 /* Increase the size indicated in RLI to account for empty classes
6234 that are "off the end" of the class. */
6236 static void
6238 {
6239 tree eoc;
6240 tree rli_size;
6242 /* It might be the case that we grew the class to allocate a
6243 zero-sized base class. That won't be reflected in RLI, yet,
6244 because we are willing to overlay multiple bases at the same
6245 offset. However, now we need to make sure that RLI is big enough
6246 to reflect the entire class. */
6252 {
6253 /* The size should have been rounded to a whole byte. */
6256 rli->bitpos
6265 }
6266 }
6268 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6269 BINFO_OFFSETs for all of the base-classes. Position the vtable
6270 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6272 static void
6274 {
6275 tree non_static_data_members;
6276 tree field;
6277 tree vptr;
6278 record_layout_info rli;
6279 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6280 types that appear at that offset. */
6281 splay_tree empty_base_offsets;
6282 /* True if the last field laid out was a bit-field. */
6284 /* The location at which the next field should be inserted. */
6286 /* T, as a base class. */
6287 tree base_t;
6289 /* Keep track of the first non-static data member. */
6292 /* Start laying out the record. */
6295 /* Mark all the primary bases in the hierarchy. */
6298 /* Create a pointer to our virtual function table. */
6301 /* The vptr is always the first thing in the class. */
6303 {
6308 }
6309 else
6312 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6317 /* Layout the non-static data members. */
6319 {
6320 tree type;
6321 tree padding;
6323 /* We still pass things that aren't non-static data members to
6324 the back end, in case it wants to do something with them. */
6326 {
6328 /* If the static data member has incomplete type, keep track
6329 of it so that it can be completed later. (The handling
6330 of pending statics in finish_record_layout is
6331 insufficient; consider:
6333 struct S1;
6334 struct S2 { static S1 s1; };
6336 At this point, finish_record_layout will be called, but
6337 S1 is still incomplete.) */
6339 {
6341 /* The visibility of static data members is determined
6342 at their point of declaration, not their point of
6343 definition. */
6345 }
6347 }
6355 /* If this field is a bit-field whose width is greater than its
6356 type, then there are some special rules for allocating
6357 it. */
6360 {
6362 tree integer_type;
6364 /* We must allocate the bits as if suitably aligned for the
6365 longest integer type that fits in this many bits. type
6366 of the field. Then, we are supposed to use the left over
6367 bits as additional padding. */
6376 /* ITK now indicates a type that is too large for the
6377 field. We have to back up by one to find the largest
6378 type that fits. */
6379 do
6380 {
6385 /* Figure out how much additional padding is required. */
6387 {
6389 /* In a union, the padding field must have the full width
6390 of the bit-field; all fields start at offset zero. */
6392 else
6395 }
6397 /* An unnamed bitfield does not normally affect the
6398 alignment of the containing class on a target where
6399 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6400 make any exceptions for unnamed bitfields when the
6401 bitfields are longer than their types. Therefore, we
6402 temporarily give the field a name. */
6404 {
6407 }
6413 empty_base_offsets);
6416 /* Now that layout has been performed, set the size of the
6417 field to the size of its declared type; the rest of the
6418 field is effectively invisible. */
6420 /* We must also reset the DECL_MODE of the field. */
6422 }
6423 else
6425 empty_base_offsets);
6427 /* Remember the location of any empty classes in FIELD. */
6430 empty_base_offsets,
6433 /* If a bit-field does not immediately follow another bit-field,
6434 and yet it starts in the middle of a byte, we have failed to
6435 comply with the ABI. */
6438 /* The TREE_NO_WARNING flag gets set by Objective-C when
6439 laying out an Objective-C class. The ObjC ABI differs
6440 from the C++ ABI, and so we do not want a warning
6441 here. */
6443 && !last_field_was_bitfield
6446 bitsize_unit_node)))
6448 "offset of %qD is not ABI-compliant and may "
6451 /* The middle end uses the type of expressions to determine the
6452 possible range of expression values. In order to optimize
6453 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6454 must be made aware of the width of "i", via its type.
6456 Because C++ does not have integer types of arbitrary width,
6457 we must (for the purposes of the front end) convert from the
6458 type assigned here to the declared type of the bitfield
6459 whenever a bitfield expression is used as an rvalue.
6460 Similarly, when assigning a value to a bitfield, the value
6461 must be converted to the type given the bitfield here. */
6463 {
6468 {
6475 }
6476 }
6478 /* If we needed additional padding after this field, add it
6479 now. */
6481 {
6482 tree padding_field;
6485 FIELD_DECL,
6486 NULL_TREE,
6487 char_type_node);
6494 NULL_TREE,
6495 empty_base_offsets);
6496 }
6499 }
6502 {
6503 /* Make sure that we are on a byte boundary so that the size of
6504 the class without virtual bases will always be a round number
6505 of bytes. */
6508 }
6510 /* Delete all zero-width bit-fields from the list of fields. Now
6511 that the type is laid out they are no longer important. */
6514 /* Create the version of T used for virtual bases. We do not use
6515 make_class_type for this version; this is an artificial type. For
6516 a POD type, we just reuse T. */
6518 {
6521 /* Set the size and alignment for the new type. */
6522 tree eoc;
6524 /* If the ABI version is not at least two, and the last
6525 field was a bit-field, RLI may not be on a byte
6526 boundary. In particular, rli_size_unit_so_far might
6527 indicate the last complete byte, while rli_size_so_far
6528 indicates the total number of bits used. Therefore,
6529 rli_size_so_far, rather than rli_size_unit_so_far, is
6530 used to compute TYPE_SIZE_UNIT. */
6538 eoc);
6548 /* Copy the fields from T. */
6552 {
6556 }
6559 /* Record the base version of the type. */
6562 }
6563 else
6566 /* Every empty class contains an empty class. */
6570 /* Set the TYPE_DECL for this type to contain the right
6571 value for DECL_OFFSET, so that we can use it as part
6572 of a COMPONENT_REF for multiple inheritance. */
6575 /* Now fix up any virtual base class types that we left lying
6576 around. We must get these done before we try to lay out the
6577 virtual function table. As a side-effect, this will remove the
6578 base subobject fields. */
6581 /* Make sure that empty classes are reflected in RLI at this
6582 point. */
6585 /* Make sure not to create any structures with zero size. */
6591 /* If this is a non-POD, declaring it packed makes a difference to how it
6592 can be used as a field; don't let finalize_record_size undo it. */
6596 /* Let the back end lay out the type. */
6605 /* Warn about bases that can't be talked about due to ambiguity. */
6608 /* Now that we're done with layout, give the base fields the real types. */
6613 /* Clean up. */
6620 }
6622 /* Determine the "key method" for the class type indicated by TYPE,
6623 and set CLASSTYPE_KEY_METHOD accordingly. */
6625 void
6627 {
6628 tree method;
6631 || processing_template_decl
6636 /* The key method is the first non-pure virtual function that is not
6637 inline at the point of class definition. On some targets the
6638 key function may not be inline; those targets should not call
6639 this function until the end of the translation unit. */
6646 {
6649 }
6652 }
6655 /* Allocate and return an instance of struct sorted_fields_type with
6656 N fields. */
6660 {
6667 }
6669 /* Helper of find_flexarrays. Return true when FLD refers to a non-static
6670 class data member of non-zero size, otherwise false. */
6674 {
6682 {
6686 }
6689 }
6691 /* Used by find_flexarrays and related. */
6693 /* The first flexible array member or non-zero array member found
6694 in order of layout. */
6695 tree array;
6696 /* First non-static non-empty data member in the class or its bases. */
6697 tree first;
6698 /* First non-static non-empty data member following either the flexible
6699 array member, if found, or the zero-length array member. */
6700 tree after;
6701 };
6703 /* Find either the first flexible array member or the first zero-length
6704 array, in that order or preference, among members of class T (but not
6705 its base classes), and set members of FMEM accordingly. */
6707 static void
6709 {
6711 {
6712 /* Find the next non-static data member if it exists. */
6721 {
6722 /* Members of anonymous structs and unions are treated as if
6723 they were members of the containing class. Descend into
6724 the anonymous struct or union and find a flexible array
6725 member or zero-length array among its fields. */
6728 }
6730 /* Skip anything that's not a (non-static) data member. */
6734 /* Skip virtual table pointers. */
6739 {
6740 /* Remember the first non-static data member. */
6744 /* Remember the first non-static data member after the flexible
6745 array member, if one has been found, or the zero-length array
6746 if it has been found. */
6749 }
6751 /* Skip non-arrays. */
6755 /* Determine the upper bound of the array if it has one. */
6757 {
6759 {
6760 /* Make a record of the zero-length array if either one
6761 such field or a flexible array member has been seen to
6762 handle the pathological and unlikely case of multiple
6763 such members. */
6766 }
6768 /* Remember the first zero-length array unless a flexible array
6769 member has already been seen. */
6771 }
6772 else
6773 {
6774 /* Flexible array members have no upper bound. */
6776 {
6777 /* Replace the zero-length array if it's been stored and
6778 reset the after pointer. */
6780 {
6783 }
6784 }
6785 else
6787 }
6788 }
6789 }
6791 /* Issue diagnostics for invalid flexible array members or zero-length
6792 arrays that are not the last elements of the containing class or its
6793 base classes or that are its sole members. */
6795 static void
6797 {
6798 /* Members of anonymous structs and unions are considered to be members
6799 of the containing struct or union. */
6806 {
6816 }
6817 else
6818 {
6825 {
6829 /* In the unlikely event that the member following the flexible
6830 array member is declared in a different class, point to it.
6831 Otherwise it should be obvious. */
6839 }
6840 }
6841 }
6844 /* Recursively check to make sure that any flexible array or zero-length
6845 array members of class T or its bases are valid (i.e., not the sole
6846 non-static data member of T and, if one exists, that it is the last
6847 non-static data member of T and its base classes. FMEM is expected
6848 to be initially null and is used internally by recursive calls to
6849 the function. Issue the appropriate diagnostics for the array member
6850 that fails the checks. */
6852 static void
6854 {
6855 /* Initialize the result of a search for flexible array and zero-length
6856 array members. Avoid doing any work if the most interesting FMEM data
6857 have already been populated. */
6864 /* Recursively check the primary base class first. */
6866 {
6869 }
6871 /* Recursively check the base classes. */
6874 {
6877 /* The primary base class was already checked above. */
6881 /* Virtual base classes are at the end. */
6885 /* Check the base class. */
6887 }
6890 {
6891 /* Check virtual base classes only once per derived class.
6892 I.e., this check is not performed recursively for base
6893 classes. */
6895 tree base_binfo;
6899 {
6900 /* Check the virtual base class. */
6904 }
6905 }
6907 /* Search the members of the current (derived) class. */
6911 {
6912 /* Issue diagnostics for invalid flexible and zero-length array members
6913 found in base classes or among the members of the current class. */
6915 }
6916 }
6918 /* Perform processing required when the definition of T (a class type)
6919 is complete. Diagnose invalid definitions of flexible array members
6920 and zero-size arrays. */
6922 void
6924 {
6925 tree x;
6926 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6930 {
6935 }
6937 /* If this type was previously laid out as a forward reference,
6938 make sure we lay it out again. */
6942 /* Make assumptions about the class; we'll reset the flags if
6943 necessary. */
6949 /* Do end-of-class semantic processing: checking the validity of the
6950 bases and members and add implicitly generated methods. */
6953 /* Find the key method. */
6955 {
6956 /* The Itanium C++ ABI permits the key method to be chosen when
6957 the class is defined -- even though the key method so
6958 selected may later turn out to be an inline function. On
6959 some systems (such as ARM Symbian OS) the key method cannot
6960 be determined until the end of the translation unit. On such
6961 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6962 will cause the class to be added to KEYED_CLASSES. Then, in
6963 finish_file we will determine the key method. */
6967 /* If a polymorphic class has no key method, we may emit the vtable
6968 in every translation unit where the class definition appears. If
6969 we're devirtualizing, we can look into the vtable even if we
6970 aren't emitting it. */
6973 }
6975 /* Layout the class itself. */
6978 /* We use the base type for trivial assignments, and hence it
6979 needs a mode. */
6982 /* With the layout complete, check for flexible array members and
6983 zero-length arrays that might overlap other members in the final
6984 layout. */
6989 /* If necessary, create the primary vtable for this class. */
6991 {
6992 /* We must enter these virtuals into the table. */
6996 /* Here we know enough to change the type of our virtual
6997 function table, but we will wait until later this function. */
7000 /* If we're warning about ABI tags, check the types of the new
7001 virtual functions. */
7005 }
7008 {
7010 tree fn;
7017 /* Add entries for virtual functions introduced by this class. */
7021 /* Set DECL_VINDEX for all functions declared in this class. */
7023 fn;
7025 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
7027 {
7031 /* A thunk. We should never be calling this entry directly
7032 from this vtable -- we'd use the entry for the non
7033 thunk base function. */
7037 }
7038 }
7045 /* Complete the rtl for any static member objects of the type we're
7046 working on. */
7053 /* Done with FIELDS...now decide whether to sort these for
7054 faster lookups later.
7056 We use a small number because most searches fail (succeeding
7057 ultimately as the search bores through the inheritance
7058 hierarchy), and we want this failure to occur quickly. */
7062 /* Complain if one of the field types requires lower visibility. */
7065 /* Make the rtl for any new vtables we have created, and unmark
7066 the base types we marked. */
7069 /* Build the VTT for T. */
7072 /* This warning does not make sense for Java classes, since they
7073 cannot have destructors. */
7078 "%q#T has virtual functions and accessible"
7086 /* Class layout, assignment of virtual table slots, etc., is now
7087 complete. Give the back end a chance to tweak the visibility of
7088 the class or perform any other required target modifications. */
7098 /* Finish debugging output for this type. */
7102 {
7105 {
7108 }
7110 {
7113 else
7114 {
7117 }
7119 }
7121 {
7123 "the type of the first field has a different ABI from the "
7126 }
7127 }
7128 }
7130 /* Insert FIELDS into T for the sorted case if the FIELDS count is
7131 equal to THRESHOLD or greater than THRESHOLD. */
7133 static void
7135 {
7138 {
7143 }
7144 }
7146 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
7148 void
7150 {
7153 {
7155 int n_fields
7166 }
7167 }
7169 /* When T was built up, the member declarations were added in reverse
7170 order. Rearrange them to declaration order. */
7172 void
7174 {
7175 tree next;
7176 tree prev;
7177 tree x;
7179 /* The following lists are all in reverse order. Put them in
7180 declaration order now. */
7184 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
7185 reverse order, so we can't just use nreverse. */
7190 {
7194 }
7196 {
7200 }
7201 }
7203 tree
7205 {
7208 /* Now that we've got all the field declarations, reverse everything
7209 as necessary. */
7215 /* Nadger the current location so that diagnostics point to the start of
7216 the struct, not the end. */
7220 {
7221 tree x;
7227 /* We need to emit an error message if this type was used as a parameter
7228 and it is an abstract type, even if it is a template. We construct
7229 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
7230 account and we call complete_vars with this type, which will check
7231 the PARM_DECLS. Note that while the type is being defined,
7232 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
7233 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
7239 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
7240 an enclosing scope is a template class, so that this function be
7241 found by lookup_fnfields_1 when the using declaration is not
7242 instantiated yet. */
7245 {
7250 }
7252 /* Remember current #pragma pack value. */
7255 /* Fix up any variants we've already built. */
7257 {
7262 }
7263 }
7264 else
7268 {
7269 /* People keep complaining that the compiler crashes on an invalid
7270 definition of initializer_list, so I guess we should explicitly
7271 reject it. What the compiler internals care about is that it's a
7272 template and has a pointer field followed by an integer field. */
7275 {
7278 {
7282 }
7283 }
7286 "definition of std::initializer_list does not match "
7288 }
7296 else
7300 /* Lambdas are defined by the LAMBDA_EXPR. */
7305 }
7306 \f
7307 /* Hash table to avoid endless recursion when handling references. */
7310 /* Return the dynamic type of INSTANCE, if known.
7311 Used to determine whether the virtual function table is needed
7312 or not.
7314 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7315 of our knowledge of its type. *NONNULL should be initialized
7316 before this function is called. */
7318 static tree
7320 {
7321 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7324 {
7328 else
7332 /* This is a call to a constructor, hence it's never zero. */
7334 {
7338 }
7342 /* This is a call to a constructor, hence it's never zero. */
7344 {
7348 }
7357 /* Propagate nonnull. */
7362 CASE_CONVERT:
7368 {
7369 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7370 with a real object -- given &p->f, p can still be null. */
7372 /* ??? Probably should check DECL_WEAK here. */
7375 }
7379 /* If this component is really a base class reference, then the field
7380 itself isn't definitive. */
7389 {
7393 }
7394 /* fall through... */
7399 {
7403 }
7405 {
7409 /* if we're in a ctor or dtor, we know our type. If
7410 current_class_ptr is set but we aren't in a function, we're in
7411 an NSDMI (and therefore a constructor). */
7416 {
7420 }
7421 }
7423 {
7424 /* We only need one hash table because it is always left empty. */
7426 fixed_type_or_null_ref_ht
7429 /* Reference variables should be references to objects. */
7433 /* Enter the INSTANCE in a table to prevent recursion; a
7434 variable's initializer may refer to the variable
7435 itself. */
7440 {
7441 tree type;
7450 }
7451 }
7456 }
7457 #undef RECUR
7458 }
7460 /* Return nonzero if the dynamic type of INSTANCE is known, and
7461 equivalent to the static type. We also handle the case where
7462 INSTANCE is really a pointer. Return negative if this is a
7463 ctor/dtor. There the dynamic type is known, but this might not be
7464 the most derived base of the original object, and hence virtual
7465 bases may not be laid out according to this type.
7467 Used to determine whether the virtual function table is needed
7468 or not.
7470 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7471 of our knowledge of its type. *NONNULL should be initialized
7472 before this function is called. */
7474 int
7476 {
7479 tree fixed;
7481 /* processing_template_decl can be false in a template if we're in
7482 instantiate_non_dependent_expr, but we still want to suppress
7483 this check. */
7485 {
7486 /* In a template we only care about the type of the result. */
7490 }
7500 }
7502 \f
7503 void
7505 {
7508 current_class_stack
7516 }
7518 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7520 static void
7522 {
7523 tree type;
7525 /* We are re-entering the same class we just left, so we don't
7526 have to search the whole inheritance matrix to find all the
7527 decls to bind again. Instead, we install the cached
7528 class_shadowed list and walk through it binding names. */
7531 /* Restore IDENTIFIER_TYPE_VALUE. */
7533 type;
7536 }
7538 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7539 appropriate for TYPE.
7541 So that we may avoid calls to lookup_name, we cache the _TYPE
7542 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7544 For multiple inheritance, we perform a two-pass depth-first search
7545 of the type lattice. */
7547 void
7549 {
7550 class_stack_node_t csn;
7554 /* Make sure there is enough room for the new entry on the stack. */
7556 {
7558 current_class_stack
7560 current_class_stack_size);
7561 }
7563 /* Insert a new entry on the class stack. */
7570 current_class_depth++;
7572 /* Now set up the new type. */
7578 /* By default, things in classes are private, while things in
7579 structures or unions are public. */
7581 ? access_private_node
7587 {
7588 /* Forcibly remove any old class remnants. */
7590 }
7596 else
7598 }
7600 /* When we exit a toplevel class scope, we save its binding level so
7601 that we can restore it quickly. Here, we've entered some other
7602 class, so we must invalidate our cache. */
7604 void
7606 {
7608 }
7610 /* Get out of the current class scope. If we were in a class scope
7611 previously, that is the one popped to. */
7613 void
7615 {
7618 current_class_depth--;
7624 }
7626 /* Mark the top of the class stack as hidden. */
7628 void
7630 {
7633 }
7635 /* Mark the top of the class stack as un-hidden. */
7637 void
7639 {
7642 }
7644 /* Returns 1 if the class type currently being defined is either T or
7645 a nested type of T. Returns the type from the current_class_stack,
7646 which might be equivalent to but not equal to T in case of
7647 constrained partial specializations. */
7649 tree
7651 {
7659 /* We start looking from 1 because entry 0 is from global scope,
7660 and has no type. */
7662 {
7663 tree c;
7666 else
7667 {
7671 }
7676 }
7678 }
7680 /* If either current_class_type or one of its enclosing classes are derived
7681 from T, return the appropriate type. Used to determine how we found
7682 something via unqualified lookup. */
7684 tree
7686 {
7689 /* The bases of a dependent type are unknown. */
7700 {
7705 }
7708 }
7710 /* Return the outermost enclosing class type that is still open, or
7711 NULL_TREE. */
7713 tree
7715 {
7722 {
7729 }
7731 }
7733 /* Returns the innermost class type which is not a lambda closure type. */
7735 tree
7737 {
7740 /* We start looking from 1 because entry 0 is from global scope,
7741 and has no type. */
7743 {
7744 tree c;
7747 else
7748 {
7752 }
7757 }
7759 }
7761 /* When entering a class scope, all enclosing class scopes' names with
7762 static meaning (static variables, static functions, types and
7763 enumerators) have to be visible. This recursive function calls
7764 pushclass for all enclosing class contexts until global or a local
7765 scope is reached. TYPE is the enclosed class. */
7767 void
7769 {
7770 /* A namespace might be passed in error cases, like A::B:C. */
7778 }
7780 /* Undoes a push_nested_class call. */
7782 void
7784 {
7790 }
7792 /* Returns the number of extern "LANG" blocks we are nested within. */
7794 int
7796 {
7798 }
7800 /* Set global variables CURRENT_LANG_NAME to appropriate value
7801 so that behavior of name-mangling machinery is correct. */
7803 void
7805 {
7809 {
7811 }
7813 {
7815 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7816 (See record_builtin_java_type in decl.c.) However, that causes
7817 incorrect debug entries if these types are actually used.
7818 So we re-enable debug output after extern "Java". */
7827 }
7829 {
7831 }
7832 else
7834 }
7836 /* Get out of the current language scope. */
7838 void
7840 {
7842 }
7843 \f
7844 /* Type instantiation routines. */
7846 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7847 matches the TARGET_TYPE. If there is no satisfactory match, return
7848 error_mark_node, and issue an error & warning messages under
7849 control of FLAGS. Permit pointers to member function if FLAGS
7850 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7851 a template-id, and EXPLICIT_TARGS are the explicitly provided
7852 template arguments.
7854 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7855 is the base path used to reference those member functions. If
7856 the address is resolved to a member function, access checks will be
7857 performed and errors issued if appropriate. */
7859 static tree
7861 tree overload,
7862 tsubst_flags_t complain,
7864 tree explicit_targs,
7865 tree access_path)
7866 {
7867 /* Here's what the standard says:
7869 [over.over]
7871 If the name is a function template, template argument deduction
7872 is done, and if the argument deduction succeeds, the deduced
7873 arguments are used to generate a single template function, which
7874 is added to the set of overloaded functions considered.
7876 Non-member functions and static member functions match targets of
7877 type "pointer-to-function" or "reference-to-function." Nonstatic
7878 member functions match targets of type "pointer-to-member
7879 function;" the function type of the pointer to member is used to
7880 select the member function from the set of overloaded member
7881 functions. If a nonstatic member function is selected, the
7882 reference to the overloaded function name is required to have the
7883 form of a pointer to member as described in 5.3.1.
7885 If more than one function is selected, any template functions in
7886 the set are eliminated if the set also contains a non-template
7887 function, and any given template function is eliminated if the
7888 set contains a second template function that is more specialized
7889 than the first according to the partial ordering rules 14.5.5.2.
7890 After such eliminations, if any, there shall remain exactly one
7891 selected function. */
7894 /* We store the matches in a TREE_LIST rooted here. The functions
7895 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7896 interoperability with most_specialized_instantiation. */
7898 tree fn;
7899 tree target_fn_type;
7901 /* By the time we get here, we should be seeing only real
7902 pointer-to-member types, not the internal POINTER_TYPE to
7903 METHOD_TYPE representation. */
7909 /* Check that the TARGET_TYPE is reasonable. */
7914 /* This is OK, too. */
7917 /* This is OK, too. This comes from a conversion to reference
7918 type. */
7920 else
7921 {
7927 }
7929 /* Non-member functions and static member functions match targets of type
7930 "pointer-to-function" or "reference-to-function." Nonstatic member
7931 functions match targets of type "pointer-to-member-function;" the
7932 function type of the pointer to member is used to select the member
7933 function from the set of overloaded member functions.
7935 So figure out the FUNCTION_TYPE that we want to match against. */
7938 /* If we can find a non-template function that matches, we can just
7939 use it. There's no point in generating template instantiations
7940 if we're just going to throw them out anyhow. But, of course, we
7941 can only do this when we don't *need* a template function. */
7943 {
7944 tree fns;
7947 {
7951 /* We're not looking for templates just yet. */
7956 /* We're looking for a non-static member, and this isn't
7957 one, or vice versa. */
7960 /* Ignore functions which haven't been explicitly
7961 declared. */
7965 /* See if there's a match. */
7970 }
7971 }
7973 /* Now, if we've already got a match (or matches), there's no need
7974 to proceed to the template functions. But, if we don't have a
7975 match we need to look at them, too. */
7977 {
7978 tree target_arg_types;
7979 tree target_ret_type;
7980 tree fns;
7983 tree arg;
7997 {
7999 tree instantiation;
8000 tree targs;
8003 /* We're only looking for templates. */
8008 /* We're not looking for a non-static member, and this is
8009 one, or vice versa. */
8014 /* If the template has a deduced return type, don't expose it to
8015 template argument deduction. */
8019 /* Try to do argument deduction. */
8026 /* Instantiation failed. */
8029 /* Constraints must be satisfied. This is done before
8030 return type deduction since that instantiates the
8031 function. */
8035 /* And now force instantiation to do return type deduction. */
8037 {
8043 }
8045 /* See if there's a match. */
8050 }
8052 /* Now, remove all but the most specialized of the matches. */
8054 {
8059 NULL_TREE,
8060 NULL_TREE);
8061 }
8062 }
8064 /* Now we should have exactly one function in MATCHES. */
8066 {
8067 /* There were *no* matches. */
8069 {
8072 target_type);
8075 }
8077 }
8079 {
8080 /* There were too many matches. First check if they're all
8081 the same function. */
8086 /* For multi-versioned functions, more than one match is just fine and
8087 decls_match will return false as they are different. */
8095 {
8097 {
8100 target_type);
8102 /* Since print_candidates expects the functions in the
8103 TREE_VALUE slot, we flip them here. */
8108 }
8111 }
8112 }
8114 /* Good, exactly one match. Now, convert it to the correct type. */
8119 {
8127 {
8130 }
8131 }
8133 /* If a pointer to a function that is multi-versioned is requested, the
8134 pointer to the dispatcher function is returned instead. This works
8135 well because indirectly calling the function will dispatch the right
8136 function version at run-time. */
8138 {
8142 /* Mark all the versions corresponding to the dispatcher as used. */
8145 }
8147 /* If we're doing overload resolution purely for the purpose of
8148 determining conversion sequences, we should not consider the
8149 function used. If this conversion sequence is selected, the
8150 function will be marked as used at this point. */
8152 {
8153 /* Make =delete work with SFINAE. */
8158 }
8160 /* We could not check access to member functions when this
8161 expression was originally created since we did not know at that
8162 time to which function the expression referred. */
8164 {
8167 }
8171 else
8172 {
8173 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
8174 will mark the function as addressed, but here we must do it
8175 explicitly. */
8179 }
8180 }
8182 /* This function will instantiate the type of the expression given in
8183 RHS to match the type of LHSTYPE. If errors exist, then return
8184 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
8185 we complain on errors. If we are not complaining, never modify rhs,
8186 as overload resolution wants to try many possible instantiations, in
8187 the hope that at least one will work.
8189 For non-recursive calls, LHSTYPE should be a function, pointer to
8190 function, or a pointer to member function. */
8192 tree
8194 {
8201 {
8205 }
8208 {
8215 /* Microsoft allows `A::f' to be resolved to a
8216 pointer-to-member. */
8217 ;
8218 else
8219 {
8224 }
8225 }
8228 {
8231 }
8233 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
8234 deduce any type information. */
8236 {
8240 }
8242 /* There only a few kinds of expressions that may have a type
8243 dependent on overload resolution. */
8249 /* This should really only be used when attempting to distinguish
8250 what sort of a pointer to function we have. For now, any
8251 arithmetic operation which is not supported on pointers
8252 is rejected as an error. */
8255 {
8257 {
8263 /* Do not lose object's side effects. */
8267 }
8274 /* This can happen if we are forming a pointer-to-member for a
8275 member template. */
8278 /* Fall through. */
8281 {
8285 return
8289 }
8293 return
8297 access_path);
8300 {
8305 }
8312 }
8314 }
8315 \f
8316 /* Return the name of the virtual function pointer field
8317 (as an IDENTIFIER_NODE) for the given TYPE. Note that
8318 this may have to look back through base types to find the
8319 ultimate field name. (For single inheritance, these could
8320 all be the same name. Who knows for multiple inheritance). */
8322 static tree
8324 {
8331 {
8337 }
8345 }
8347 void
8349 {
8356 {
8361 }
8362 }
8364 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8365 according to [class]:
8366 The class-name is also inserted
8367 into the scope of the class itself. For purposes of access checking,
8368 the inserted class name is treated as if it were a public member name. */
8370 void
8372 {
8375 tree saved_cas;
8390 }
8392 /* Returns 1 if TYPE contains only padding bytes. */
8394 int
8396 {
8404 }
8406 /* Returns true if TYPE contains no actual data, just various
8407 possible combinations of empty classes and possibly a vptr. */
8409 bool
8411 {
8413 {
8414 tree field;
8415 tree binfo;
8416 tree base_binfo;
8419 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8420 out, but we'd like to be able to check this before then. */
8431 /* An unnamed bit-field is not a data member. */
8436 }
8441 }
8443 /* Note that NAME was looked up while the current class was being
8444 defined and that the result of that lookup was DECL. */
8446 void
8448 {
8449 splay_tree names_used;
8451 /* If we're not defining a class, there's nothing to do. */
8457 /* If there's already a binding for this NAME, then we don't have
8458 anything to worry about. */
8471 }
8473 /* Note that NAME was declared (as DECL) in the current class. Check
8474 to see that the declaration is valid. */
8476 void
8478 {
8479 splay_tree names_used;
8480 splay_tree_node n;
8482 /* Look to see if we ever used this name. */
8483 names_used
8487 /* The C language allows members to be declared with a type of the same
8488 name, and the C++ standard says this diagnostic is not required. So
8489 allow it in extern "C" blocks unless predantic is specified.
8490 Allow it in all cases if -ms-extensions is specified. */
8496 {
8497 /* [basic.scope.class]
8499 A name N used in a class S shall refer to the same declaration
8500 in its context and when re-evaluated in the completed scope of
8501 S. */
8506 }
8507 }
8509 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8510 Secondary vtables are merged with primary vtables; this function
8511 will return the VAR_DECL for the primary vtable. */
8513 tree
8515 {
8516 tree decl;
8520 {
8523 }
8527 }
8530 /* Returns the binfo for the primary base of BINFO. If the resulting
8531 BINFO is a virtual base, and it is inherited elsewhere in the
8532 hierarchy, then the returned binfo might not be the primary base of
8533 BINFO in the complete object. Check BINFO_PRIMARY_P or
8534 BINFO_LOST_PRIMARY_P to be sure. */
8536 static tree
8538 {
8539 tree primary_base;
8546 }
8548 /* As above, but iterate until we reach the binfo that actually provides the
8549 vptr for BINFO. */
8551 static tree
8553 {
8557 {
8562 }
8564 }
8566 /* Returns true if BINFO gets its vptr from a virtual base of the most derived
8567 type. Note that the virtual inheritance might be above or below BINFO in
8568 the hierarchy. */
8570 bool
8572 {
8576 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is
8577 a morally virtual base. */
8580 }
8582 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8584 static int
8586 {
8590 }
8592 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8593 INDENT should be zero when called from the top level; it is
8594 incremented recursively. IGO indicates the next expected BINFO in
8595 inheritance graph ordering. */
8597 static tree
8600 tree binfo,
8601 tree igo,
8603 {
8605 tree base_binfo;
8613 {
8616 }
8631 {
8635 TFF_PLAIN_IDENTIFIER),
8637 }
8639 {
8642 }
8647 {
8651 {
8655 TFF_PLAIN_IDENTIFIER));
8656 }
8658 {
8662 TFF_PLAIN_IDENTIFIER));
8663 }
8665 {
8669 TFF_PLAIN_IDENTIFIER));
8670 }
8672 {
8676 TFF_PLAIN_IDENTIFIER));
8677 }
8681 }
8687 }
8689 /* Dump the BINFO hierarchy for T. */
8691 static void
8693 {
8705 }
8707 /* Debug interface to hierarchy dumping. */
8709 void
8711 {
8713 }
8715 static void
8717 {
8722 {
8724 }
8725 }
8727 static void
8729 {
8730 tree value;
8732 HOST_WIDE_INT elt;
8740 TFF_PLAIN_IDENTIFIER));
8747 }
8749 static void
8751 {
8759 {
8766 {
8771 }
8775 }
8776 }
8778 static void
8780 {
8788 {
8793 }
8794 }
8796 /* Dump a function or thunk and its thunkees. */
8798 static void
8800 {
8803 tree thunks;
8811 {
8821 else
8827 }
8831 }
8833 /* Dump the thunks for FN. */
8835 void
8837 {
8839 }
8841 /* Virtual function table initialization. */
8843 /* Create all the necessary vtables for T and its base classes. */
8845 static void
8847 {
8848 tree vbase;
8852 /* We lay out the primary and secondary vtables in one contiguous
8853 vtable. The primary vtable is first, followed by the non-virtual
8854 secondary vtables in inheritance graph order. */
8858 /* Then come the virtual bases, also in inheritance graph order. */
8860 {
8864 }
8868 }
8870 /* Initialize the vtable for BINFO with the INITS. */
8872 static void
8874 {
8875 tree decl;
8881 }
8883 /* Build the VTT (virtual table table) for T.
8884 A class requires a VTT if it has virtual bases.
8886 This holds
8887 1 - primary virtual pointer for complete object T
8888 2 - secondary VTTs for each direct non-virtual base of T which requires a
8889 VTT
8890 3 - secondary virtual pointers for each direct or indirect base of T which
8891 has virtual bases or is reachable via a virtual path from T.
8892 4 - secondary VTTs for each direct or indirect virtual base of T.
8894 Secondary VTTs look like complete object VTTs without part 4. */
8896 static void
8898 {
8899 tree type;
8900 tree vtt;
8901 tree index;
8904 /* Build up the initializers for the VTT. */
8909 /* If we didn't need a VTT, we're done. */
8913 /* Figure out the type of the VTT. */
8917 /* Now, build the VTT object itself. */
8920 /* Add the VTT to the vtables list. */
8925 }
8927 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8928 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8929 and CHAIN the vtable pointer for this binfo after construction is
8930 complete. VALUE can also be another BINFO, in which case we recurse. */
8932 static tree
8934 {
8935 tree vt;
8938 {
8944 else
8946 }
8949 }
8951 /* Data for secondary VTT initialization. */
8952 struct secondary_vptr_vtt_init_data
8953 {
8954 /* Is this the primary VTT? */
8957 /* Current index into the VTT. */
8958 tree index;
8960 /* Vector of initializers built up. */
8963 /* The type being constructed by this secondary VTT. */
8964 tree type_being_constructed;
8965 };
8967 /* Recursively build the VTT-initializer for BINFO (which is in the
8968 hierarchy dominated by T). INITS points to the end of the initializer
8969 list to date. INDEX is the VTT index where the next element will be
8970 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8971 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8972 for virtual bases of T. When it is not so, we build the constructor
8973 vtables for the BINFO-in-T variant. */
8975 static void
8978 {
8980 tree b;
8981 tree init;
8982 secondary_vptr_vtt_init_data data;
8985 /* We only need VTTs for subobjects with virtual bases. */
8989 /* We need to use a construction vtable if this is not the primary
8990 VTT. */
8992 {
8995 /* Record the offset in the VTT where this sub-VTT can be found. */
8997 }
8999 /* Add the address of the primary vtable for the complete object. */
9003 {
9006 }
9009 /* Recursively add the secondary VTTs for non-virtual bases. */
9014 /* Add secondary virtual pointers for all subobjects of BINFO with
9015 either virtual bases or reachable along a virtual path, except
9016 subobjects that are non-virtual primary bases. */
9026 /* data.inits might have grown as we added secondary virtual pointers.
9027 Make sure our caller knows about the new vector. */
9031 /* Add the secondary VTTs for virtual bases in inheritance graph
9032 order. */
9034 {
9039 }
9040 else
9041 /* Remove the ctor vtables we created. */
9043 }
9045 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
9046 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
9048 static tree
9050 {
9053 /* We don't care about bases that don't have vtables. */
9057 /* We're only interested in proper subobjects of the type being
9058 constructed. */
9062 /* We're only interested in bases with virtual bases or reachable
9063 via a virtual path from the type being constructed. */
9068 /* We're not interested in non-virtual primary bases. */
9072 /* Record the index where this secondary vptr can be found. */
9074 {
9079 {
9080 /* It's a primary virtual base, and this is not a
9081 construction vtable. Find the base this is primary of in
9082 the inheritance graph, and use that base's vtable
9083 now. */
9086 }
9087 }
9089 /* Add the initializer for the secondary vptr itself. */
9092 /* Advance the vtt index. */
9097 }
9099 /* Called from build_vtt_inits via dfs_walk. After building
9100 constructor vtables and generating the sub-vtt from them, we need
9101 to restore the BINFO_VTABLES that were scribbled on. DATA is the
9102 binfo of the base whose sub vtt was generated. */
9104 static tree
9106 {
9110 /* If this class has no vtable, none of its bases do. */
9114 /* This might be a primary base, so have no vtable in this
9115 hierarchy. */
9118 /* If we scribbled the construction vtable vptr into BINFO, clear it
9119 out now. */
9125 }
9127 /* Build the construction vtable group for BINFO which is in the
9128 hierarchy dominated by T. */
9130 static void
9132 {
9133 tree type;
9134 tree vtbl;
9135 tree id;
9136 tree vbase;
9139 /* See if we've already created this construction vtable group. */
9145 /* Build a version of VTBL (with the wrong type) for use in
9146 constructing the addresses of secondary vtables in the
9147 construction vtable group. */
9150 /* Don't export construction vtables from shared libraries. Even on
9151 targets that don't support hidden visibility, this tells
9152 can_refer_decl_in_current_unit_p not to assume that it's safe to
9153 access from a different compilation unit (bz 54314). */
9161 /* Add the vtables for each of our virtual bases using the vbase in T
9162 binfo. */
9164 vbase;
9166 {
9167 tree b;
9174 }
9176 /* Figure out the type of the construction vtable. */
9183 /* Initialize the construction vtable. */
9187 }
9189 /* Add the vtbl initializers for BINFO (and its bases other than
9190 non-virtual primaries) to the list of INITS. BINFO is in the
9191 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
9192 the constructor the vtbl inits should be accumulated for. (If this
9193 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
9194 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
9195 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
9196 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
9197 but are not necessarily the same in terms of layout. */
9199 static void
9201 tree orig_binfo,
9202 tree rtti_binfo,
9203 tree vtbl,
9204 tree t,
9206 {
9208 tree base_binfo;
9213 /* If it doesn't have a vptr, we don't do anything. */
9217 /* If we're building a construction vtable, we're not interested in
9218 subobjects that don't require construction vtables. */
9224 /* Build the initializers for the BINFO-in-T vtable. */
9227 /* Walk the BINFO and its bases. We walk in preorder so that as we
9228 initialize each vtable we can figure out at what offset the
9229 secondary vtable lies from the primary vtable. We can't use
9230 dfs_walk here because we need to iterate through bases of BINFO
9231 and RTTI_BINFO simultaneously. */
9233 {
9234 /* Skip virtual bases. */
9240 inits);
9241 }
9242 }
9244 /* Called from accumulate_vtbl_inits. Adds the initializers for the
9245 BINFO vtable to L. */
9247 static void
9249 tree orig_binfo,
9250 tree rtti_binfo,
9251 tree orig_vtbl,
9252 tree t,
9254 {
9261 {
9262 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
9263 primary virtual base. If it is not the same primary in
9264 the hierarchy of T, we'll need to generate a ctor vtable
9265 for it, to place at its location in T. If it is the same
9266 primary, we still need a VTT entry for the vtable, but it
9267 should point to the ctor vtable for the base it is a
9268 primary for within the sub-hierarchy of RTTI_BINFO.
9270 There are three possible cases:
9272 1) We are in the same place.
9273 2) We are a primary base within a lost primary virtual base of
9274 RTTI_BINFO.
9275 3) We are primary to something not a base of RTTI_BINFO. */
9277 tree b;
9280 /* First, look through the bases we are primary to for RTTI_BINFO
9281 or a virtual base. */
9284 {
9289 }
9290 /* If we run out of primary links, keep looking down our
9291 inheritance chain; we might be an indirect primary. */
9295 found:
9297 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
9298 base B and it is a base of RTTI_BINFO, this is case 2. In
9299 either case, we share our vtable with LAST, i.e. the
9300 derived-most base within B of which we are a primary. */
9303 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
9304 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
9305 binfo_ctor_vtable after everything's been set up. */
9308 /* Otherwise, this is case 3 and we get our own. */
9309 }
9316 {
9317 tree index;
9320 /* Add the initializer for this vtable. */
9324 /* Figure out the position to which the VPTR should point. */
9330 }
9333 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
9334 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
9335 straighten this out. */
9338 /* Throw away any unneeded intializers. */
9340 else
9341 /* For an ordinary vtable, set BINFO_VTABLE. */
9343 }
9347 /* Construct the initializer for BINFO's virtual function table. BINFO
9348 is part of the hierarchy dominated by T. If we're building a
9349 construction vtable, the ORIG_BINFO is the binfo we should use to
9350 find the actual function pointers to put in the vtable - but they
9351 can be overridden on the path to most-derived in the graph that
9352 ORIG_BINFO belongs. Otherwise,
9353 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
9354 BINFO that should be indicated by the RTTI information in the
9355 vtable; it will be a base class of T, rather than T itself, if we
9356 are building a construction vtable.
9358 The value returned is a TREE_LIST suitable for wrapping in a
9359 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9360 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9361 number of non-function entries in the vtable.
9363 It might seem that this function should never be called with a
9364 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9365 base is always subsumed by a derived class vtable. However, when
9366 we are building construction vtables, we do build vtables for
9367 primary bases; we need these while the primary base is being
9368 constructed. */
9370 static void
9372 tree orig_binfo,
9373 tree t,
9374 tree rtti_binfo,
9377 {
9378 tree v;
9379 vtbl_init_data vid;
9381 tree vbinfo;
9385 /* Initialize VID. */
9393 /* The first vbase or vcall offset is at index -3 in the vtable. */
9396 /* Add entries to the vtable for RTTI. */
9399 /* Create an array for keeping track of the functions we've
9400 processed. When we see multiple functions with the same
9401 signature, we share the vcall offsets. */
9403 /* Add the vcall and vbase offset entries. */
9406 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9407 build_vbase_offset_vtbl_entries. */
9412 /* If the target requires padding between data entries, add that now. */
9414 {
9419 /* Move data entries into their new positions and add padding
9420 after the new positions. Iterate backwards so we don't
9421 overwrite entries that we would need to process later. */
9424 ix--)
9425 {
9433 {
9437 null_pointer_node);
9438 }
9439 }
9440 }
9445 /* The initializers for virtual functions were built up in reverse
9446 order. Straighten them out and add them to the running list in one
9447 step. */
9456 /* Go through all the ordinary virtual functions, building up
9457 initializers. */
9459 {
9460 tree delta;
9461 tree vcall_index;
9468 {
9472 {
9475 }
9477 }
9479 /* If the only definition of this function signature along our
9480 primary base chain is from a lost primary, this vtable slot will
9481 never be used, so just zero it out. This is important to avoid
9482 requiring extra thunks which cannot be generated with the function.
9484 We first check this in update_vtable_entry_for_fn, so we handle
9485 restored primary bases properly; we also need to do it here so we
9486 zero out unused slots in ctor vtables, rather than filling them
9487 with erroneous values (though harmless, apart from relocation
9488 costs). */
9493 {
9494 /* Pull the offset for `this', and the function to call, out of
9495 the list. */
9502 /* You can't call an abstract virtual function; it's abstract.
9503 So, we replace these functions with __pure_virtual. */
9505 {
9508 {
9510 abort_fndecl_addr
9514 }
9515 }
9516 /* Likewise for deleted virtuals. */
9518 {
9527 }
9528 else
9529 {
9531 {
9535 }
9536 /* Take the address of the function, considering it to be of an
9537 appropriate generic type. */
9541 /* Don't refer to a virtual destructor from a constructor
9542 vtable or a vtable for an abstract class, since destroying
9543 an object under construction is undefined behavior and we
9544 don't want it to be considered a candidate for speculative
9545 devirtualization. But do create the thunk for ABI
9546 compliance. */
9551 }
9552 }
9554 /* And add it to the chain of initializers. */
9556 {
9561 else
9563 {
9569 }
9570 }
9571 else
9573 }
9574 }
9576 /* Adds to vid->inits the initializers for the vbase and vcall
9577 offsets in BINFO, which is in the hierarchy dominated by T. */
9579 static void
9581 {
9582 tree b;
9584 /* If this is a derived class, we must first create entries
9585 corresponding to the primary base class. */
9590 /* Add the vbase entries for this base. */
9592 /* Add the vcall entries for this base. */
9594 }
9596 /* Returns the initializers for the vbase offset entries in the vtable
9597 for BINFO (which is part of the class hierarchy dominated by T), in
9598 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9599 where the next vbase offset will go. */
9601 static void
9603 {
9604 tree vbase;
9605 tree t;
9606 tree non_primary_binfo;
9608 /* If there are no virtual baseclasses, then there is nothing to
9609 do. */
9615 /* We might be a primary base class. Go up the inheritance hierarchy
9616 until we find the most derived class of which we are a primary base:
9617 it is the offset of that which we need to use. */
9620 {
9621 tree b;
9623 /* If we have reached a virtual base, then it must be a primary
9624 base (possibly multi-level) of vid->binfo, or we wouldn't
9625 have called build_vcall_and_vbase_vtbl_entries for it. But it
9626 might be a lost primary, so just skip down to vid->binfo. */
9628 {
9631 }
9637 }
9639 /* Go through the virtual bases, adding the offsets. */
9641 vbase;
9643 {
9644 tree b;
9645 tree delta;
9650 /* Find the instance of this virtual base in the complete
9651 object. */
9654 /* If we've already got an offset for this virtual base, we
9655 don't need another one. */
9660 /* Figure out where we can find this vbase offset. */
9669 /* The vbase offset had better be the same. */
9672 /* The next vbase will come at a more negative offset. */
9676 /* The initializer is the delta from BINFO to this virtual base.
9677 The vbase offsets go in reverse inheritance-graph order, and
9678 we are walking in inheritance graph order so these end up in
9679 the right order. */
9686 }
9687 }
9689 /* Adds the initializers for the vcall offset entries in the vtable
9690 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9691 to VID->INITS. */
9693 static void
9695 {
9696 /* We only need these entries if this base is a virtual base. We
9697 compute the indices -- but do not add to the vtable -- when
9698 building the main vtable for a class. */
9701 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9702 correspond to VID->DERIVED), we are building a primary
9703 construction virtual table. Since this is a primary
9704 virtual table, we do not need the vcall offsets for
9705 BINFO. */
9707 {
9708 /* We need a vcall offset for each of the virtual functions in this
9709 vtable. For example:
9711 class A { virtual void f (); };
9712 class B1 : virtual public A { virtual void f (); };
9713 class B2 : virtual public A { virtual void f (); };
9714 class C: public B1, public B2 { virtual void f (); };
9716 A C object has a primary base of B1, which has a primary base of A. A
9717 C also has a secondary base of B2, which no longer has a primary base
9718 of A. So the B2-in-C construction vtable needs a secondary vtable for
9719 A, which will adjust the A* to a B2* to call f. We have no way of
9720 knowing what (or even whether) this offset will be when we define B2,
9721 so we store this "vcall offset" in the A sub-vtable and look it up in
9722 a "virtual thunk" for B2::f.
9724 We need entries for all the functions in our primary vtable and
9725 in our non-virtual bases' secondary vtables. */
9727 /* If we are just computing the vcall indices -- but do not need
9728 the actual entries -- not that. */
9731 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9733 }
9734 }
9736 /* Build vcall offsets, starting with those for BINFO. */
9738 static void
9740 {
9742 tree primary_binfo;
9743 tree base_binfo;
9745 /* Don't walk into virtual bases -- except, of course, for the
9746 virtual base for which we are building vcall offsets. Any
9747 primary virtual base will have already had its offsets generated
9748 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9752 /* If BINFO has a primary base, process it first. */
9757 /* Add BINFO itself to the list. */
9760 /* Scan the non-primary bases of BINFO. */
9764 }
9766 /* Called from build_vcall_offset_vtbl_entries_r. */
9768 static void
9770 {
9771 /* Make entries for the rest of the virtuals. */
9772 tree orig_fn;
9774 /* The ABI requires that the methods be processed in declaration
9775 order. */
9777 orig_fn;
9781 }
9783 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9785 static void
9787 {
9789 tree vcall_offset;
9790 tree derived_entry;
9792 /* If there is already an entry for a function with the same
9793 signature as FN, then we do not need a second vcall offset.
9794 Check the list of functions already present in the derived
9795 class vtable. */
9797 {
9799 /* We only use one vcall offset for virtual destructors,
9800 even though there are two virtual table entries. */
9804 }
9806 /* If we are building these vcall offsets as part of building
9807 the vtable for the most derived class, remember the vcall
9808 offset. */
9810 {
9813 }
9815 /* The next vcall offset will be found at a more negative
9816 offset. */
9820 /* Keep track of this function. */
9824 {
9825 tree base;
9826 tree fn;
9828 /* Find the overriding function. */
9832 else
9833 {
9836 /* The vbase we're working on is a primary base of
9837 vid->binfo. But it might be a lost primary, so its
9838 BINFO_OFFSET might be wrong, so we just use the
9839 BINFO_OFFSET from vid->binfo. */
9845 vcall_offset);
9846 }
9847 /* Add the initializer to the vtable. */
9849 }
9850 }
9852 /* Return vtbl initializers for the RTTI entries corresponding to the
9853 BINFO's vtable. The RTTI entries should indicate the object given
9854 by VID->rtti_binfo. */
9856 static void
9858 {
9859 tree b;
9860 tree t;
9861 tree offset;
9862 tree decl;
9863 tree init;
9867 /* To find the complete object, we will first convert to our most
9868 primary base, and then add the offset in the vtbl to that value. */
9873 /* The second entry is the address of the typeinfo object. */
9876 else
9879 /* Convert the declaration to a type that can be stored in the
9880 vtable. */
9884 /* Add the offset-to-top entry. It comes earlier in the vtable than
9885 the typeinfo entry. Convert the offset to look like a
9886 function pointer, so that we can put it in the vtable. */
9889 }
9891 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9892 accessibility. */
9894 bool
9896 {
9899 }
9901 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9903 bool
9905 {
9909 }
9911 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9912 class between them, if any. */
9914 tree
9916 {
9928 {
9931 }
9935 }