| blob | f16e50b9de9d7dba8ebfffbdaf69365cbb09ff2c |
1 /* Functions related to building -*- C++ -*- classes and their related objects.
2 Copyright (C) 1987-2021 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. */
41 /* Id for dumping the class hierarchy. */
44 /* The number of nested classes being processed. If we are not in the
45 scope of any class, this is zero. */
49 /* In order to deal with nested classes, we keep a stack of classes.
50 The topmost entry is the innermost class, and is the entry at index
51 CURRENT_CLASS_DEPTH */
54 /* The name of the class. */
55 tree name;
57 /* The _TYPE node for the class. */
58 tree type;
60 /* The access specifier pending for new declarations in the scope of
61 this class. */
62 tree access;
64 /* If were defining TYPE, the names used in this class. */
65 splay_tree names_used;
67 /* Nonzero if this class is no longer open, because of a call to
68 push_to_top_level. */
72 struct vtbl_init_data
73 {
74 /* The base for which we're building initializers. */
75 tree binfo;
76 /* The type of the most-derived type. */
77 tree derived;
78 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
79 unless ctor_vtbl_p is true. */
80 tree rtti_binfo;
81 /* The negative-index vtable initializers built up so far. These
82 are in order from least negative index to most negative index. */
84 /* The binfo for the virtual base for which we're building
85 vcall offset initializers. */
86 tree vbase;
87 /* The functions in vbase for which we have already provided vcall
88 offsets. */
90 /* The vtable index of the next vcall or vbase offset. */
91 tree index;
92 /* Nonzero if we are building the initializer for the primary
93 vtable. */
95 /* Nonzero if we are building the initializer for a construction
96 vtable. */
98 /* True when adding vcall offset entries to the vtable. False when
99 merely computing the indices. */
101 };
103 /* The type of a function passed to walk_subobject_offsets. */
106 /* The stack itself. This is a dynamically resized array. The
107 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
111 /* The size of the largest empty class seen in this translation unit. */
141 /* Used by find_flexarrays and related functions. */
189 tree *);
198 splay_tree_key k2);
209 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
211 void
213 {
218 else
220 }
222 /* Return a COND_EXPR that executes TRUE_STMT if this execution of the
223 'structor is in charge of 'structing virtual bases, or FALSE_STMT
224 otherwise. */
226 tree
228 {
238 }
240 /* Convert to or from a base subobject. EXPR is an expression of type
241 `A' or `A*', an expression of type `B' or `B*' is returned. To
242 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
243 the B base instance within A. To convert base A to derived B, CODE
244 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
245 In this latter case, A must not be a morally virtual base of B.
246 NONNULL is true if EXPR is known to be non-NULL (this is only
247 needed when EXPR is of pointer type). CV qualifiers are preserved
248 from EXPR. */
250 tree
252 tree expr,
253 tree binfo,
255 tsubst_flags_t complain)
256 {
259 tree probe;
260 tree offset;
261 tree target_type;
263 tree ptr_target_type;
274 {
280 }
291 {
292 /* This can happen when adjust_result_of_qualified_name_lookup can't
293 find a unique base binfo in a call to a member function. We
294 couldn't give the diagnostic then since we might have been calling
295 a static member function, so we do it now. In other cases, eg.
296 during error recovery (c++/71979), we may not have a base at all. */
298 {
302 }
304 }
311 /* Nothing to do. */
315 {
317 {
319 {
322 "pointer to derived class %qT because the base is "
324 else
328 }
329 else
330 {
336 else
340 }
341 }
343 }
346 || processing_template_decl
349 /* For a non-pointer simple base reference, express it as a COMPONENT_REF
350 without taking its address (and so causing lambda capture, 91933). */
355 {
357 /* This must happen before the call to save_expr. */
359 }
360 else
366 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
367 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
368 expression returned matches the input. */
369 target_type = cp_build_qualified_type
373 /* Do we need to look in the vtable for the real offset? */
376 /* Don't bother with the calculations inside sizeof; they'll ICE if the
377 source type is incomplete and the pointer value doesn't matter. In a
378 template (even in instantiate_non_dependent_expr), we don't have vtables
379 set up properly yet, and the value doesn't matter there either; we're
380 just interested in the result of overload resolution. */
382 {
385 }
388 {
394 }
396 /* If we're in an NSDMI, we don't have the full constructor context yet
397 that we need for converting to a virtual base, so just build a stub
398 CONVERT_EXPR and expand it later in bot_replace. */
401 {
405 }
407 /* Do we need to check for a null pointer? */
409 {
410 /* If we know the conversion will not actually change the value
411 of EXPR, then we can avoid testing the expression for NULL.
412 We have to avoid generating a COMPONENT_REF for a base class
413 field, because other parts of the compiler know that such
414 expressions are always non-NULL. */
418 }
420 /* Protect against multiple evaluation if necessary. */
424 /* Store EXPR and build the real null test just before returning. */
428 /* If this is a simple base reference, express it as a COMPONENT_REF. */
430 /* We don't build base fields for empty bases, and they aren't very
431 interesting to the optimizers anyway. */
433 {
442 }
445 {
446 /* Going via virtual base V_BINFO. We need the static offset
447 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
448 V_BINFO. That offset is an entry in D_BINFO's vtable. */
449 tree v_offset;
452 {
453 /* In a base member initializer, we cannot rely on the
454 vtable being set up. We have to indirect via the
455 vtt_parm. */
456 tree t;
462 }
463 else
464 {
468 {
473 }
476 }
484 v_offset);
496 /* Negative fixed_type_p means this is a constructor or destructor;
497 virtual base layout is fixed in in-charge [cd]tors, but not in
498 base [cd]tors. */
499 offset = build_if_in_charge
501 v_offset);
502 else
504 }
510 {
515 }
516 else
521 indout:
523 {
527 }
529 out:
531 /* Wrap EXPR in a null test. */
535 }
537 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
538 Perform a derived-to-base conversion by recursively building up a
539 sequence of COMPONENT_REFs to the appropriate base fields. */
541 static tree
543 {
546 tree field;
549 {
550 tree temp;
554 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
555 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
556 an lvalue in the front end; only _DECLs and _REFs are lvalues
557 in the back end. */
563 }
565 /* Recurse. */
570 /* Is this the base field created by build_base_field? */
574 /* If we're looking for a field in the most-derived class,
575 also check the field offset; we can have two base fields
576 of the same type if one is an indirect virtual base and one
577 is a direct non-virtual base. */
581 {
582 /* We don't use build_class_member_access_expr here, as that
583 has unnecessary checks, and more importantly results in
584 recursive calls to dfs_walk_once. */
590 /* Mark the expression const or volatile, as appropriate.
591 Even though we've dealt with the type above, we still have
592 to mark the expression itself. */
599 }
601 /* Didn't find the base field?!? */
603 }
605 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
606 type is a class type or a pointer to a class type. In the former
607 case, TYPE is also a class type; in the latter it is another
608 pointer type. If CHECK_ACCESS is true, an error message is emitted
609 if TYPE is inaccessible. If OBJECT has pointer type, the value is
610 assumed to be non-NULL. */
612 tree
614 tsubst_flags_t complain)
615 {
616 tree binfo;
617 tree object_type;
620 {
623 }
624 else
633 }
635 /* EXPR is an expression with unqualified class type. BASE is a base
636 binfo of that class type. Returns EXPR, converted to the BASE
637 type. This function assumes that EXPR is the most derived class;
638 therefore virtual bases can be found at their static offsets. */
640 tree
642 {
643 tree expr_type;
647 {
648 /* If this is a non-empty base, use a COMPONENT_REF. */
652 /* We use fold_build2 and fold_convert below to simplify the trees
653 provided to the optimizers. It is not safe to call these functions
654 when processing a template because they do not handle C++-specific
655 trees. */
663 }
666 }
668 /* True IFF EXPR is a reference to an empty base class "subobject", as built in
669 convert_to_base_statically. We look for the result of the fold_convert
670 call, a NOP_EXPR from one pointer type to another, where the target is an
671 empty base of the original type. */
673 bool
675 {
694 }
695 \f
696 tree
698 {
702 /* Can happen in case of duplicate base types (c++/59082). */
706 /* First, convert to the requested type. */
711 /* Second, the requested type may not be the owner of its own vptr.
712 If not, convert to the base class that owns it. We cannot use
713 convert_to_base here, because VCONTEXT may appear more than once
714 in the inheritance hierarchy of TYPE, and thus direct conversion
715 between the types may be ambiguous. Following the path back up
716 one step at a time via primary bases avoids the problem. */
720 {
723 }
726 }
728 /* Given an object INSTANCE, return an expression which yields the
729 vtable element corresponding to INDEX. There are many special
730 cases for INSTANCE which we take care of here, mainly to avoid
731 creating extra tree nodes when we don't have to. */
733 tree
735 {
736 tree aref;
739 /* Try to figure out what a reference refers to, and
740 access its virtual function table directly. */
748 {
753 }
762 }
764 /* Given a stable object pointer INSTANCE_PTR, return an expression which
765 yields a function pointer corresponding to vtable element INDEX. */
767 tree
769 {
770 tree aref;
774 /* When using function descriptors, the address of the
775 vtable entry is treated as a function pointer. */
780 /* Remember this as a method reference, for later devirtualization. */
784 }
786 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
787 for the given TYPE. */
789 static tree
791 {
793 }
795 /* DECL is an entity associated with TYPE, like a virtual table or an
796 implicitly generated constructor. Determine whether or not DECL
797 should have external or internal linkage at the object file
798 level. This routine does not deal with COMDAT linkage and other
799 similar complexities; it simply sets TREE_PUBLIC if it possible for
800 entities in other translation units to contain copies of DECL, in
801 the abstract. */
803 void
805 {
808 }
810 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
811 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
812 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
814 static tree
816 {
817 tree decl;
820 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
821 now to avoid confusion in mangle_decl. */
832 /* The vtable has not been defined -- yet. */
836 /* Mark the VAR_DECL node representing the vtable itself as a
837 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
838 is rather important that such things be ignored because any
839 effort to actually generate DWARF for them will run into
840 trouble when/if we encounter code like:
842 #pragma interface
843 struct S { virtual void member (); };
845 because the artificial declaration of the vtable itself (as
846 manufactured by the g++ front end) will say that the vtable is
847 a static member of `S' but only *after* the debug output for
848 the definition of `S' has already been output. This causes
849 grief because the DWARF entry for the definition of the vtable
850 will try to refer back to an earlier *declaration* of the
851 vtable as a static member of `S' and there won't be one. We
852 might be able to arrange to have the "vtable static member"
853 attached to the member list for `S' before the debug info for
854 `S' get written (which would solve the problem) but that would
855 require more intrusive changes to the g++ front end. */
859 }
861 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
862 or even complete. If this does not exist, create it. If COMPLETE is
863 nonzero, then complete the definition of it -- that will render it
864 impossible to actually build the vtable, but is useful to get at those
865 which are known to exist in the runtime. */
867 tree
869 {
870 tree decl;
879 {
882 }
885 }
887 /* Build the primary virtual function table for TYPE. If BINFO is
888 non-NULL, build the vtable starting with the initial approximation
889 that it is the same as the one which is the head of the association
890 list. Returns a nonzero value if a new vtable is actually
891 created. */
893 static int
895 {
896 tree decl;
897 tree virtuals;
902 {
904 /* We have already created a vtable for this base, so there's
905 no need to do it again. */
912 }
913 else
914 {
917 }
919 /* Initialize the association list for this type, based
920 on our first approximation. */
925 }
927 /* Give BINFO a new virtual function table which is initialized
928 with a skeleton-copy of its original initialization. The only
929 entry that changes is the `delta' entry, so we can really
930 share a lot of structure.
932 FOR_TYPE is the most derived type which caused this table to
933 be needed.
935 Returns nonzero if we haven't met BINFO before.
937 The order in which vtables are built (by calling this function) for
938 an object must remain the same, otherwise a binary incompatibility
939 can result. */
941 static int
943 {
945 /* We already created a vtable for this base. There's no need to
946 do it again. */
949 /* Remember that we've created a vtable for this BINFO, so that we
950 don't try to do so again. */
953 /* Make fresh virtual list, so we can smash it later. */
956 /* Secondary vtables are laid out as part of the same structure as
957 the primary vtable. */
960 }
962 /* Create a new vtable for BINFO which is the hierarchy dominated by
963 T. Return nonzero if we actually created a new vtable. */
965 static int
967 {
969 /* In this case, it is *type*'s vtable we are modifying. We start
970 with the approximation that its vtable is that of the
971 immediate base class. */
973 else
974 /* This is our very own copy of `basetype' to play with. Later,
975 we will fill in all the virtual functions that override the
976 virtual functions in these base classes which are not defined
977 by the current type. */
979 }
981 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
982 (which is in the hierarchy dominated by T) list FNDECL as its
983 BV_FN. DELTA is the required constant adjustment from the `this'
984 pointer where the vtable entry appears to the `this' required when
985 the function is actually called. */
987 static void
989 tree binfo,
990 tree fndecl,
991 tree delta,
993 {
994 tree v;
1000 {
1001 /* We need a new vtable for BINFO. */
1003 {
1004 /* If we really did make a new vtable, we also made a copy
1005 of the BINFO_VIRTUALS list. Now, we have to find the
1006 corresponding entry in that list. */
1011 }
1016 }
1017 }
1019 \f
1020 /* Add method METHOD to class TYPE. If VIA_USING indicates whether
1021 METHOD is being injected via a using_decl. Returns true if the
1022 method could be added to the method vec. */
1024 bool
1026 {
1035 /* See below. */
1038 /* Check to see if we've already got this method. */
1040 {
1046 /* Two using-declarations can coexist, we'll complain about ambiguity in
1047 overload resolution. */
1049 /* Except handle inherited constructors specially. */
1053 /* [over.load] Member function declarations with the
1054 same name and the same parameter types cannot be
1055 overloaded if any of them is a static member
1056 function declaration.
1058 [over.load] Member function declarations with the same name and
1059 the same parameter-type-list as well as member function template
1060 declarations with the same name, the same parameter-type-list, and
1061 the same template parameter lists cannot be overloaded if any of
1062 them, but not all, have a ref-qualifier.
1064 [namespace.udecl] When a using-declaration brings names
1065 from a base class into a derived class scope, member
1066 functions in the derived class override and/or hide member
1067 functions with the same name and parameter types in a base
1068 class (rather than conflicting). */
1072 /* Compare the quals on the 'this' parm. Don't compare
1073 the whole types, as used functions are treated as
1074 coming from the using class in overload resolution. */
1077 /* Either both or neither need to be ref-qualified for
1078 differing quals to allow overloading. */
1088 /* Templates and conversion ops must match return types. */
1093 /* For templates, the template parameters must be identical. */
1095 {
1102 }
1111 /* Bring back parameters omitted from an inherited ctor. The
1112 method and the function can have different omittedness. */
1116 parms2 = (FUNCTION_FIRST_USER_PARMTYPE
1123 {
1125 /* We can't check satisfaction in dependent context, wait until
1126 the class is instantiated. */
1134 /* Member function templates and non-special member functions
1135 coexist if they are not equivalently constrained. A member
1136 function is not hidden by an inherited constructor. */
1139 /* P0848: For special member functions, deleted, unsatisfied, or
1140 less constrained overloads are ineligible. We implement this
1141 by removing them from CLASSTYPE_MEMBER_VEC. Destructors don't
1142 use the notion of eligibility, and the selected destructor can
1143 be deleted, but removing unsatisfied or less constrained
1144 overloads has the same effect as overload resolution. */
1154 else
1157 /* Leave FN in the method vec, discard METHOD. */
1160 {
1161 /* Remove FN, add METHOD. */
1164 }
1165 else
1166 /* Let them coexist for now. */
1168 }
1170 /* If these are versions of the same function, process and
1171 move on. */
1177 {
1179 /* Defer to the other function. */
1185 {
1187 {
1188 /* Inheriting the same constructor along different
1189 paths, combine them. */
1190 SET_DECL_INHERITED_CTOR
1193 /* And discard the new one. */
1195 }
1196 else
1197 /* Inherited ctors can coexist until overload
1198 resolution. */
1200 }
1207 basef);
1209 }
1212 /* Defer to the local function. */
1216 {
1217 /* Remove the inherited constructor. */
1220 }
1221 else
1222 {
1228 }
1229 }
1240 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1246 }
1248 /* Subroutines of finish_struct. */
1250 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1251 legit, otherwise return 0. */
1253 static int
1255 {
1256 tree elem;
1264 {
1266 {
1270 else
1273 }
1274 else
1275 {
1276 /* They're changing the access to the same thing they changed
1277 it to before. That's OK. */
1278 ;
1279 }
1280 }
1281 else
1282 {
1284 tf_warning_or_error);
1287 }
1289 }
1291 /* Return the access node for DECL's access in its enclosing class. */
1293 tree
1295 {
1299 }
1301 /* Process the USING_DECL, which is a member of T. */
1303 static void
1305 {
1310 tree old_value;
1315 tf_warning_or_error);
1317 {
1322 else
1324 }
1332 ;
1334 {
1336 /* It's OK to use functions from a base when there are functions with
1338 else
1339 {
1346 }
1347 }
1349 {
1356 }
1360 /* Make type T see field decl FDECL with access ACCESS. */
1363 {
1366 }
1368 {
1369 /* C++20 using enum can import non-inherited enumerators into class
1370 scope. We implement that by making a copy of the CONST_DECL for which
1371 CONST_DECL_USING_P is true. */
1379 /* We emitted debug info for the USING_DECL above; make sure we don't
1380 also emit anything for this clone. */
1385 }
1386 else
1388 }
1389 \f
1390 /* Data structure for find_abi_tags_r, below. */
1392 struct abi_tag_data
1393 {
1397 };
1399 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1400 in the context of P. TAG can be either an identifier (the DECL_NAME of
1401 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1403 static void
1405 {
1407 {
1409 {
1410 /* We're collecting tags from template arguments or from
1411 the type of a variable or function return type. */
1414 /* Don't inherit this tag multiple times. */
1418 {
1419 /* Tags inherited from type template arguments are only used
1420 to avoid warnings. */
1423 }
1424 /* For functions and variables we want to warn, too. */
1425 }
1427 /* Otherwise we're diagnosing missing tags. */
1429 {
1430 auto_diagnostic_group d;
1435 }
1437 {
1438 auto_diagnostic_group d;
1442 }
1444 {
1445 auto_diagnostic_group d;
1450 }
1451 else
1452 {
1453 auto_diagnostic_group d;
1457 {
1461 }
1462 }
1463 }
1464 }
1466 /* Find all the ABI tags in the attribute list ATTR and either call
1467 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1469 static void
1471 {
1478 {
1483 else
1485 }
1486 }
1488 /* Find all the ABI tags on T and its enclosing scopes and either call
1489 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1491 static void
1493 {
1495 {
1496 tree attr;
1498 {
1501 }
1502 else
1503 {
1506 }
1508 }
1509 }
1511 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1512 types with ABI tags, add the corresponding identifiers to the VEC in
1513 *DATA and set IDENTIFIER_MARKED. */
1515 static tree
1517 {
1519 /* Tell cp_walk_subtrees to look though typedefs. [PR98481] */
1525 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1526 anyway, but let's make sure of it. */
1534 }
1536 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1537 IDENTIFIER_MARKED on its ABI tags. */
1539 static tree
1541 {
1543 /* Tell cp_walk_subtrees to look though typedefs. */
1549 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1550 anyway, but let's make sure of it. */
1558 }
1560 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1561 scopes. */
1563 static void
1565 {
1568 {
1571 {
1572 /* Template arguments are part of the signature. */
1575 {
1578 }
1579 }
1581 /* A function's parameter types are part of the signature, so
1582 we don't need to inherit any tags that are also in them. */
1587 }
1588 }
1590 /* Check that T has all the ABI tags that subobject SUBOB has, or
1591 warn if not. If T is a (variable or function) declaration, also
1592 return any missing tags, and add them to T if JUST_CHECKING is false. */
1594 static tree
1596 {
1604 /* No need to worry about things local to this TU. */
1620 {
1623 }
1624 else
1625 {
1629 else
1632 }
1637 }
1639 /* Check that DECL has all the ABI tags that are used in parts of its type
1640 that are not reflected in its mangled name. */
1642 void
1644 {
1651 }
1653 /* Return any ABI tags that are used in parts of the type of DECL
1654 that are not reflected in its mangled name. This function is only
1655 used in backward-compatible mangling for ABI <11. */
1657 tree
1659 {
1663 /* Don't check DECL_CONV_FN_P here like we do in check_abi_tags, so
1664 that we can use this function for setting need_abi_warning
1665 regardless of the current flag_abi_version. */
1668 else
1670 }
1672 void
1674 {
1684 {
1687 {
1691 }
1692 }
1694 // If we found some tags on our template arguments, add them to our
1695 // abi_tag attribute.
1697 {
1701 else
1704 }
1707 }
1709 /* Return true, iff class T has a non-virtual destructor that is
1710 accessible from outside the class heirarchy (i.e. is public, or
1711 there's a suitable friend. */
1713 static bool
1715 {
1718 /* An implicitly declared destructor is always public. And,
1719 if it were virtual, we would have created it by now. */
1734 }
1736 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1737 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1738 properties of the bases. */
1740 static void
1744 {
1748 tree base_binfo;
1749 tree binfo;
1759 {
1768 /* If any base class is non-literal, so is the derived class. */
1772 /* If the base class doesn't have copy constructors or
1773 assignment operators that take const references, then the
1774 derived class cannot have such a member automatically
1775 generated. */
1784 /* A virtual base does not effect nearly emptiness. */
1785 ;
1787 {
1789 /* And if there is more than one nearly empty base, then the
1790 derived class is not nearly empty either. */
1792 else
1793 /* Remember we've seen one. */
1795 }
1797 /* If the base class is not empty or nearly empty, then this
1798 class cannot be nearly empty. */
1801 /* A lot of properties from the bases also apply to the derived
1802 class. */
1819 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1822 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1828 /* A standard-layout class is a class that:
1829 ...
1830 * has no non-standard-layout base classes, */
1833 {
1834 tree basefield;
1835 /* ...has no base classes of the same type as the first non-static
1836 data member... */
1838 && (same_type_ignoring_top_level_qualifiers_p
1841 /* DR 1813:
1842 ...has at most one base class subobject of any given type... */
1845 else
1846 /* ...has all non-static data members and bit-fields in the class
1847 and its base classes first declared in the same class. */
1853 {
1856 else
1859 }
1860 }
1862 /* Don't bother collecting tm attributes if transactional memory
1863 support is not enabled. */
1865 {
1869 }
1872 }
1874 /* If one of the base classes had TM attributes, and the current class
1875 doesn't define its own, then the current class inherits one. */
1877 {
1880 }
1881 }
1883 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1884 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1885 that have had a nearly-empty virtual primary base stolen by some
1886 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1887 T. */
1889 static void
1891 {
1895 tree base_binfo;
1897 /* Determine the primary bases of our bases. */
1900 {
1903 /* See if we're the non-virtual primary of our inheritance
1904 chain. */
1906 {
1913 /* We are the primary binfo. */
1915 }
1916 /* Determine if we have a virtual primary base, and mark it so.
1917 */
1919 {
1923 /* Someone already claimed this base. */
1925 else
1926 {
1927 tree delta;
1932 /* A virtual binfo might have been copied from within
1933 another hierarchy. As we're about to use it as a
1934 primary base, make sure the offsets match. */
1942 }
1943 }
1944 }
1946 /* First look for a dynamic direct non-virtual base. */
1948 {
1952 {
1955 }
1956 }
1958 /* A "nearly-empty" virtual base class can be the primary base
1959 class, if no non-virtual polymorphic base can be found. Look for
1960 a nearly-empty virtual dynamic base that is not already a primary
1961 base of something in the hierarchy. If there is no such base,
1962 just pick the first nearly-empty virtual base. */
1968 {
1970 {
1971 /* Found one that is not primary. */
1974 }
1976 /* Remember the first candidate. */
1978 }
1980 found:
1981 /* If we've got a primary base, use it. */
1983 {
1988 /* We are stealing a primary base. */
1992 {
1993 tree delta;
1996 /* A virtual binfo might have been copied from within
1997 another hierarchy. As we're about to use it as a primary
1998 base, make sure the offsets match. */
2003 }
2010 }
2011 }
2013 /* Update the variant types of T. */
2015 void
2017 {
2022 variant;
2024 {
2025 /* These fields are in the _TYPE part of the node, not in
2026 the TYPE_LANG_SPECIFIC component, so they are not shared. */
2037 /* Copy whatever these are holding today. */
2047 {
2050 }
2055 }
2056 }
2058 /* KLASS is a class that we're applying may_alias to after the body is
2059 parsed. Fixup any POINTER_TO and REFERENCE_TO types. The
2060 canonical type(s) will be implicitly updated. */
2062 static void
2064 {
2073 }
2075 /* Early variant fixups: we apply attributes at the beginning of the class
2076 definition, and we need to fix up any variants that have already been
2077 made via elaborated-type-specifier so that check_qualified_type works. */
2079 void
2081 {
2082 tree variants;
2097 variants;
2099 {
2100 /* These are the two fields that check_qualified_type looks at and
2101 are affected by attributes. */
2106 else
2112 }
2113 }
2114 \f
2115 /* Set memoizing fields and bits of T (and its variants) for later
2116 use. */
2118 static void
2120 {
2121 /* Fix up variants (if any). */
2125 /* For a class w/o baseclasses, 'finish_struct' has set
2126 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2127 Similarly for a class whose base classes do not have vtables.
2128 When neither of these is true, we might have removed abstract
2129 virtuals (by providing a definition), added some (by declaring
2130 new ones), or redeclared ones from a base class. We need to
2131 recalculate what's really an abstract virtual at this point (by
2132 looking in the vtables). */
2135 /* If this type has a copy constructor or a destructor, force its
2136 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2137 nonzero. This will cause it to be passed by invisible reference
2138 and prevent it from being returned in a register. */
2141 {
2142 tree variants;
2145 {
2148 }
2149 }
2150 }
2152 /* Issue warnings about T having private constructors, but no friends,
2153 and so forth.
2155 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2156 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2157 non-private static member functions. */
2159 static void
2161 {
2167 /* If the class has friends, those entities might create and
2168 access instances, so we should not warn. */
2171 /* We will have warned when the template was declared; there's
2172 no need to warn on every instantiation. */
2174 /* There's no reason to even consider warning about this
2175 class. */
2178 /* We only issue one warning, if more than one applies, because
2179 otherwise, on code like:
2181 class A {
2182 // Oops - forgot `public:'
2183 A();
2184 A(const A&);
2185 ~A();
2186 };
2188 we warn several times about essentially the same problem. */
2190 /* Check to see if all (non-constructor, non-destructor) member
2191 functions are private. (Since there are no friends or
2192 non-private statics, we can't ever call any of the private member
2193 functions.) */
2202 /* We're not interested in compiler-generated methods; they don't
2205 {
2207 /* A non-private static member function is just like a
2208 friend; it can create and invoke private member
2209 functions, and be accessed without a class
2210 instance. */
2214 /* Keep searching for a static member function. */
2215 }
2220 {
2221 /* There are no non-private methods, and there's at least one
2222 private member function that isn't a constructor or
2223 destructor. (If all the private members are
2224 constructors/destructors we want to use the code below that
2225 issues error messages specifically referring to
2226 constructors/destructors.) */
2232 {
2235 }
2237 {
2241 }
2242 }
2244 /* Even if some of the member functions are non-private, the class
2245 won't be useful for much if all the constructors or destructors
2246 are private: such an object can never be created or destroyed. */
2249 {
2252 t);
2254 }
2256 /* Warn about classes that have private constructors and no friends. */
2258 /* Implicitly generated constructors are always public. */
2260 {
2263 /* If a non-template class does not define a copy
2264 constructor, one is defined for it, enabling it to avoid
2265 this warning. For a template class, this does not
2266 happen, and so we would normally get a warning on:
2268 template <class T> class C { private: C(); };
2270 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2271 complete non-template or fully instantiated classes have this
2272 flag set. */
2275 else
2280 /* Ideally, we wouldn't count any constructor that takes
2281 an argument of the class type as a parameter, because
2282 such things cannot be used to construct an instance of
2283 the class unless you already have one. */
2285 else
2286 {
2289 }
2292 {
2294 "%q#T only defines private constructors and has "
2301 }
2302 }
2303 }
2305 /* Make BINFO's vtable have N entries, including RTTI entries,
2306 vbase and vcall offsets, etc. Set its type and call the back end
2307 to lay it out. */
2309 static void
2311 {
2312 tree atype;
2313 tree vtable;
2318 /* We may have to grow the vtable. */
2321 {
2325 }
2326 }
2328 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2329 have the same signature. */
2331 int
2333 {
2334 /* One destructor overrides another if they are the same kind of
2335 destructor. */
2339 /* But a non-destructor never overrides a destructor, nor vice
2340 versa, nor do different kinds of destructors override
2341 one-another. For example, a complete object destructor does not
2342 override a deleting destructor. */
2351 {
2359 }
2361 }
2363 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2364 subobject. */
2366 static bool
2368 {
2369 tree probe;
2372 {
2376 /* If we meet a virtual base, we can't follow the inheritance
2377 any more. See if the complete type of DERIVED contains
2378 such a virtual base. */
2381 }
2383 }
2386 /* The function for which we are trying to find a final overrider. */
2387 tree fn;
2388 /* The base class in which the function was declared. */
2389 tree declaring_base;
2390 /* The candidate overriders. */
2391 tree candidates;
2392 /* Path to most derived. */
2394 };
2396 /* Add the overrider along the current path to FFOD->CANDIDATES.
2397 Returns true if an overrider was found; false otherwise. */
2399 static bool
2403 {
2404 tree method;
2406 /* If BINFO is not the most derived type, try a more derived class.
2407 A definition there will overrider a definition here. */
2409 {
2410 depth--;
2414 }
2418 {
2421 /* Remove any candidates overridden by this new function. */
2423 {
2424 /* If *CANDIDATE overrides METHOD, then METHOD
2425 cannot override anything else on the list. */
2428 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2431 else
2433 }
2435 /* Add the new function. */
2438 }
2441 }
2443 /* Called from find_final_overrider via dfs_walk. */
2445 static tree
2447 {
2455 }
2457 static tree
2459 {
2464 }
2466 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2467 FN and whose TREE_VALUE is the binfo for the base where the
2468 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2469 DERIVED) is the base object in which FN is declared. */
2471 static tree
2473 {
2474 find_final_overrider_data ffod;
2476 /* Getting this right is a little tricky. This is valid:
2478 struct S { virtual void f (); };
2479 struct T { virtual void f (); };
2480 struct U : public S, public T { };
2482 even though calling `f' in `U' is ambiguous. But,
2484 struct R { virtual void f(); };
2485 struct S : virtual public R { virtual void f (); };
2486 struct T : virtual public R { virtual void f (); };
2487 struct U : public S, public T { };
2489 is not -- there's no way to decide whether to put `S::f' or
2490 `T::f' in the vtable for `R'.
2492 The solution is to look at all paths to BINFO. If we find
2493 different overriders along any two, then there is a problem. */
2497 /* Determine the depth of the hierarchy. */
2506 /* If there was no winner, issue an error message. */
2511 }
2513 /* Return the index of the vcall offset for FN when TYPE is used as a
2514 virtual base. */
2516 static tree
2518 {
2520 tree_pair_p p;
2528 /* There should always be an appropriate index. */
2530 }
2532 /* Given a DECL_VINDEX of a virtual function found in BINFO, return the final
2533 overrider at that index in the vtable. This should only be used when we
2534 know that BINFO is correct for the dynamic type of the object. */
2536 tree
2538 {
2543 /* BINFO_VIRTUALS in a primary base isn't accurate, find the derived
2544 class that actually owns the vtable. */
2548 }
2550 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2551 dominated by T. FN is the old function; VIRTUALS points to the
2552 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2553 of that entry in the list. */
2555 static void
2558 {
2559 tree b;
2560 tree overrider;
2561 tree delta;
2562 tree virtual_base;
2563 tree first_defn;
2569 /* Find the nearest primary base (possibly binfo itself) which defines
2570 this function; this is the class the caller will convert to when
2571 calling FN through BINFO. */
2573 {
2578 /* The nearest definition is from a lost primary. */
2581 }
2584 /* Find the final overrider. */
2587 {
2590 }
2593 /* Check for adjusting covariant return types. */
2601 /* If the overrider is invalid, don't even try. */
2603 {
2604 /* If FN is a covariant thunk, we must figure out the adjustment
2605 to the final base FN was converting to. As OVERRIDER_TARGET might
2606 also be converting to the return type of FN, we have to
2607 combine the two conversions here. */
2614 {
2618 }
2619 else
2623 /* Find the equivalent binfo within the return type of the
2624 overriding function. We will want the vbase offset from
2625 there. */
2627 over_return);
2630 {
2631 /* There was no existing virtual thunk (which takes
2632 precedence). So find the binfo of the base function's
2633 return type within the overriding function's return type.
2634 Fortunately we know the covariancy is valid (it
2635 has already been checked), so we can just iterate along
2636 the binfos, which have been chained in inheritance graph
2637 order. Of course it is lame that we have to repeat the
2638 search here anyway -- we should really be caching pieces
2639 of the vtable and avoiding this repeated work. */
2643 /* Find the base binfo within the overriding function's
2644 return type. We will always find a thunk_binfo, except
2645 when the covariancy is invalid (which we will have
2646 already diagnosed). */
2655 /* See if virtual inheritance is involved. */
2657 virtual_offset;
2664 {
2668 {
2669 /* We convert via virtual base. Adjust the fixed
2670 offset to be from there. */
2671 offset =
2675 }
2677 /* There was an existing fixed offset, this must be
2678 from the base just converted to, and the base the
2679 FN was thunking to. */
2681 else
2683 }
2684 }
2687 /* Replace the overriding function with a covariant thunk. We
2688 will emit the overriding function in its own slot as
2689 well. */
2692 }
2693 else
2697 /* If we need a covariant thunk, then we may need to adjust first_defn.
2698 The ABI specifies that the thunks emitted with a function are
2699 determined by which bases the function overrides, so we need to be
2700 sure that we're using a thunk for some overridden base; even if we
2701 know that the necessary this adjustment is zero, there may not be an
2702 appropriate zero-this-adjustment thunk for us to use since thunks for
2703 overriding virtual bases always use the vcall offset.
2705 Furthermore, just choosing any base that overrides this function isn't
2706 quite right, as this slot won't be used for calls through a type that
2707 puts a covariant thunk here. Calling the function through such a type
2708 will use a different slot, and that slot is the one that determines
2709 the thunk emitted for that base.
2711 So, keep looking until we find the base that we're really overriding
2712 in this slot: the nearest primary base that doesn't use a covariant
2713 thunk in this slot. */
2715 {
2717 /* We already know that the overrider needs a covariant thunk. */
2720 {
2727 }
2729 }
2731 /* Assume that we will produce a thunk that convert all the way to
2732 the final overrider, and not to an intermediate virtual base. */
2735 /* See if we can convert to an intermediate virtual base first, and then
2736 use the vcall offset located there to finish the conversion. */
2738 {
2739 /* If we find the final overrider, then we can stop
2740 walking. */
2745 /* If we find a virtual base, and we haven't yet found the
2746 overrider, then there is a virtual base between the
2747 declaring base (first_defn) and the final overrider. */
2749 {
2752 }
2753 }
2755 /* Compute the constant adjustment to the `this' pointer. The
2756 `this' pointer, when this function is called, will point at BINFO
2757 (or one of its primary bases, which are at the same offset). */
2759 /* The `this' pointer needs to be adjusted from the declaration to
2760 the nearest virtual base. */
2765 /* If the nearest definition is in a lost primary, we don't need an
2766 entry in our vtable. Except possibly in a constructor vtable,
2767 if we happen to get our primary back. In that case, the offset
2768 will be zero, as it will be a primary base. */
2770 else
2771 /* The `this' pointer needs to be adjusted from pointing to
2772 BINFO to pointing at the base where the final overrider
2773 appears. */
2784 else
2788 }
2790 /* Called from modify_all_vtables via dfs_walk. */
2792 static tree
2794 {
2796 tree virtuals;
2797 tree old_virtuals;
2801 /* A base without a vtable needs no modification, and its bases
2802 are uninteresting. */
2807 /* Don't do the primary vtable, if it's new. */
2811 /* There's no need to modify the vtable for a non-virtual primary
2812 base; we're not going to use that vtable anyhow. We do still
2813 need to do this for virtual primary bases, as they could become
2814 non-primary in a construction vtable. */
2819 /* Now, go through each of the virtual functions in the virtual
2820 function table for BINFO. Find the final overrider, and update
2821 the BINFO_VIRTUALS list appropriately. */
2824 virtuals;
2828 binfo,
2833 }
2835 /* Update all of the primary and secondary vtables for T. Create new
2836 vtables as required, and initialize their RTTI information. Each
2837 of the functions in VIRTUALS is declared in T and may override a
2838 virtual function from a base class; find and modify the appropriate
2839 entries to point to the overriding functions. Returns a list, in
2840 declaration order, of the virtual functions that are declared in T,
2841 but do not appear in the primary base class vtable, and which
2842 should therefore be appended to the end of the vtable for T. */
2844 static tree
2846 {
2850 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2854 /* Update all of the vtables. */
2857 /* Add virtual functions not already in our primary vtable. These
2858 will be both those introduced by this class, and those overridden
2859 from secondary bases. It does not include virtuals merely
2860 inherited from secondary bases. */
2862 {
2867 {
2868 /* We don't need to adjust the `this' pointer when
2869 calling this function. */
2873 /* This is a function not already in our vtable. Keep it. */
2875 }
2876 else
2877 /* We've already got an entry for this function. Skip it. */
2879 }
2882 }
2884 /* Get the base virtual function declarations in T that have the
2885 indicated NAME. */
2887 static void
2889 {
2892 /* Find virtual functions in T with the indicated NAME. */
2894 {
2896 {
2899 }
2900 }
2907 {
2910 }
2911 }
2913 /* If this method overrides a virtual method from a base, then mark
2914 this member function as being virtual as well. Do 'final' and
2915 'override' checks too. */
2917 void
2919 {
2921 /* In [temp.mem] we have:
2923 A specialization of a member function template does not
2924 override a virtual function from a base class. */
2927 /* IDENTIFIER_VIRTUAL_P indicates whether the name has ever been
2928 used for a vfunc. That avoids the expensive look_for_overrides
2929 call that when we know there's nothing to find. As conversion
2930 operators for the same type can have distinct identifiers, we
2931 cannot optimize those in that way. */
2935 /* Check staticness after we've checked if we 'override'. */
2937 {
2938 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2939 the error_mark_node so that we know it is an overriding
2940 function. */
2949 }
2954 {
2955 /* Remember this identifier is virtual name. */
2959 /* It's a new vfunc. */
2964 }
2967 }
2969 /* Warn about hidden virtual functions that are not overridden in t.
2970 We know that constructors and destructors don't apply. */
2972 static void
2974 {
2977 {
2985 tree base_binfo;
2986 tree binfo;
2989 /* Iterate through all of the base classes looking for possibly
2990 hidden functions. */
2993 {
2996 }
2998 /* If there are no functions to hide, continue. */
3002 /* Remove any overridden functions. */
3004 {
3007 {
3008 /* If the method from the base class has the same
3009 signature as the method from the derived class, it
3010 has been overridden. */
3015 }
3016 }
3018 /* Now give a warning for all base functions without overriders,
3019 as they are hidden. */
3020 tree base_fndecl;
3023 {
3024 auto_diagnostic_group d;
3025 /* Here we know it is a hider, and no overrider exists. */
3027 OPT_Woverloaded_virtual,
3030 }
3031 }
3032 }
3034 /* Recursive helper for finish_struct_anon. */
3036 static void
3038 {
3040 {
3041 /* We're generally only interested in entities the user
3042 declared, but we also find nested classes by noticing
3043 the TYPE_DECL that we create implicitly. You're
3044 allowed to put one anonymous union inside another,
3045 though, so we explicitly tolerate that. We use
3046 TYPE_UNNAMED_P rather than ANON_AGGR_TYPE_P so that
3047 we also allow unnamed types used for defining fields. */
3056 /* Recurse into the anonymous aggregates to correctly handle
3057 access control (c++/24926):
3059 class A {
3060 union {
3061 union {
3062 int i;
3063 };
3064 };
3065 };
3067 int j=A().i; */
3071 }
3072 }
3074 /* Fix up any anonymous union/struct members of T. */
3076 static void
3078 {
3080 {
3089 }
3090 }
3092 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3093 will be used later during class template instantiation.
3094 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3095 a non-static member data (FIELD_DECL), a member function
3096 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3097 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3098 When FRIEND_P is nonzero, T is either a friend class
3099 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3100 (FUNCTION_DECL, TEMPLATE_DECL). */
3102 void
3104 {
3107 {
3112 }
3113 }
3115 /* This function is called from declare_virt_assop_and_dtor via
3116 dfs_walk_all.
3118 DATA is a type that direcly or indirectly inherits the base
3119 represented by BINFO. If BINFO contains a virtual assignment [copy
3120 assignment or move assigment] operator or a virtual constructor,
3121 declare that function in DATA if it hasn't been already declared. */
3123 static tree
3125 {
3133 /* A base without a vtable needs no modification, and its bases
3134 are uninteresting. */
3138 /* If this is a primary base, then we have already looked at the
3139 virtual functions of its vtable. */
3143 {
3147 {
3152 }
3156 }
3159 }
3161 /* If the class type T has a direct or indirect base that contains a
3162 virtual assignment operator or a virtual destructor, declare that
3163 function in T if it hasn't been already declared. */
3165 static void
3167 {
3175 dfs_declare_virt_assop_and_dtor,
3177 }
3179 /* Declare the inheriting constructor for class T inherited from base
3180 constructor CTOR with the parameter array PARMS of size NPARMS. */
3182 static void
3184 {
3187 /* We don't declare an inheriting ctor that would be a default,
3188 copy or move ctor for derived or base. */
3193 {
3197 }
3206 {
3209 }
3210 }
3212 /* Declare all the inheriting constructors for class T inherited from base
3213 constructor CTOR. */
3215 static void
3217 {
3221 {
3226 }
3231 {
3235 }
3238 {
3239 auto_diagnostic_group d;
3243 }
3244 }
3246 /* Create default constructors, assignment operators, and so forth for
3247 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3248 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3249 the class cannot have a default constructor, copy constructor
3250 taking a const reference argument, or an assignment operator taking
3251 a const reference, respectively. */
3253 static void
3257 {
3258 /* Destructor. */
3260 /* In general, we create destructors lazily. */
3269 /* [class.ctor]
3271 If there is no user-declared constructor for a class, a default
3272 constructor is implicitly declared. */
3274 {
3279 /* Don't force the declaration to get a hard answer; if the
3280 definition would have made the class non-literal, it will still be
3281 non-literal because of the base or member in question, and that
3282 gives a better diagnostic. */
3284 }
3286 /* [class.ctor]
3288 If a class definition does not explicitly declare a copy
3289 constructor, one is declared implicitly. */
3291 {
3297 }
3299 /* If there is no assignment operator, one will be created if and
3300 when it is needed. For now, just record whether or not the type
3301 of the parameter to the assignment operator will be a const or
3302 non-const reference. */
3304 {
3310 }
3312 /* We can't be lazy about declaring functions that might override
3313 a virtual function from a base class. */
3316 /* If the class definition does not explicitly declare an == operator
3317 function, but declares a defaulted three-way comparison operator function,
3318 an == operator function is declared implicitly. */
3321 {
3323 NULL_TREE);
3328 else
3329 {
3333 }
3335 }
3338 {
3342 {
3343 /* declare, then remove the decl */
3351 }
3352 else
3354 }
3355 }
3357 /* Cache of enum_min_precision values. */
3360 /* Return the minimum precision of a bit-field needed to store all
3361 enumerators of ENUMERAL_TYPE TYPE. */
3363 static int
3365 {
3367 /* For unscoped enums without fixed underlying type and without mode
3368 attribute we can just use precision of the underlying type. */
3384 {
3388 {
3399 }
3400 }
3401 else
3409 }
3411 /* FIELD is a bit-field. We are finishing the processing for its
3412 enclosing type. Issue any appropriate messages and set appropriate
3413 flags. Returns false if an error has been diagnosed. */
3415 static bool
3417 {
3419 tree w;
3421 /* Extract the declared width of the bitfield, which has been
3422 temporarily stashed in DECL_BIT_FIELD_REPRESENTATIVE by grokbitfield. */
3425 /* Remove the bit-field width indicator so that the rest of the
3426 compiler does not treat that value as a qualifier. */
3429 /* Detect invalid bit-field type. */
3431 {
3435 }
3436 else
3437 {
3439 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3442 /* detect invalid field size. */
3448 {
3451 }
3453 {
3456 }
3458 {
3461 }
3471 {
3477 }
3478 }
3481 {
3485 }
3486 else
3487 {
3488 /* Non-bit-fields are aligned for their type. */
3492 }
3493 }
3495 /* FIELD is a non bit-field. We are finishing the processing for its
3496 enclosing type T. Issue any appropriate messages and set appropriate
3497 flags. */
3499 static bool
3501 tree t,
3504 {
3508 /* In C++98 an anonymous union cannot contain any fields which would change
3509 the settings of CANT_HAVE_CONST_CTOR and friends. */
3511 ;
3512 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3513 structs. So, we recurse through their fields here. */
3515 {
3520 cant_have_const_ctor,
3521 no_const_asn_ref);
3522 }
3523 /* Check members with class type for constructors, destructors,
3524 etc. */
3526 {
3527 /* Never let anything with uninheritable virtuals
3528 make it through without complaint. */
3532 {
3537 field);
3542 field);
3544 {
3548 }
3549 }
3550 else
3551 {
3564 }
3573 }
3578 /* `build_class_init_list' does not recognize
3579 non-FIELD_DECLs. */
3583 }
3585 /* Check the data members (both static and non-static), class-scoped
3586 typedefs, etc., appearing in the declaration of T. Issue
3587 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3588 declaration order) of access declarations; each TREE_VALUE in this
3589 list is a USING_DECL.
3591 In addition, set the following flags:
3593 EMPTY_P
3594 The class is empty, i.e., contains no non-static data members.
3596 CANT_HAVE_CONST_CTOR_P
3597 This class cannot have an implicitly generated copy constructor
3598 taking a const reference.
3600 CANT_HAVE_CONST_ASN_REF
3601 This class cannot have an implicitly generated assignment
3602 operator taking a const reference.
3604 All of these flags should be initialized before calling this
3605 function. */
3607 static void
3611 {
3614 /* Assume there are no access declarations. */
3616 /* Effective C has things to say about classes with pointer members. */
3618 /* Default initialized members affect the whole class. */
3620 /* Lack of any non-static data member of non-volatile literal
3621 type affects a union. */
3623 /* Standard layout requires all FIELDS have same access. */
3627 {
3631 {
3636 /* Save the access declarations for our caller. */
3645 /* FIXME: We should fold in the checking from check_methods. */
3655 {
3656 /* [class.union]
3658 (C++98) If a union contains a static data member,
3659 ... the program is ill-formed. */
3663 }
3668 {
3669 /* [class.union]
3671 If a union contains ... or a [non-static data] member
3672 of reference type, the program is ill-formed. */
3676 }
3678 data_member:
3679 /* Common VAR_DECL & FIELD_DECL processing. */
3683 /* Template instantiation can cause this. Perhaps this
3684 should be a specific instantiation check? */
3686 {
3690 }
3692 {
3696 }
3699 }
3707 /* If it is not a union and at least one non-static data member is
3708 non-literal, the whole class becomes non-literal. Per Core/1453,
3709 volatile non-static data members and base classes are also not allowed.
3710 If it is a union, we might set CLASSTYPE_LITERAL_P after we've seen all
3711 members.
3712 Note: if the type is incomplete we will complain later on. */
3714 {
3717 else
3719 }
3724 {
3725 /* A standard-layout class is a class that:
3727 ... has the same access control (Clause 11) for all
3728 non-static data members, */
3731 else
3734 /* Aggregates must be public. */
3737 }
3739 /* If this is of reference type, check if it needs an init. */
3741 {
3747 {
3748 /* ARM $12.6.2: [A member initializer list] (or, for an
3749 aggregate, initialization by a brace-enclosed list) is the
3750 only way to initialize non-static const and reference
3751 members. */
3754 }
3755 }
3760 {
3762 {
3764 "ignoring packed attribute because of"
3767 }
3771 }
3775 /* We don't treat zero-width bitfields as making a class
3776 non-empty. */
3777 ;
3780 /* Empty data members also don't make a class non-empty. */
3782 else
3783 {
3784 /* The class is non-empty. */
3786 /* The class is not even nearly empty. */
3788 /* If one of the data members contains an empty class, so
3789 does T. */
3793 }
3795 /* This is used by -Weffc++ (see below). Warn only for pointers
3796 to members which might hold dynamic memory. So do not warn
3797 for pointers to functions or pointers to members. */
3803 {
3808 }
3814 {
3821 }
3824 /* DR 148 now allows pointers to members (which are POD themselves),
3825 to be allowed in POD structs. */
3829 /* A potentially-overlapping non-static data member makes the class
3830 non-layout-POD. */
3839 /* We set DECL_C_BIT_FIELD in grokbitfield.
3840 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3846 {
3849 {
3853 default_init_member);
3854 }
3856 }
3858 /* Now that we've removed bit-field widths from DECL_INITIAL,
3859 anything left in DECL_INITIAL is an NSDMI that makes the class
3860 non-aggregate in C++11. */
3865 {
3866 /* If any field is const, the structure type is pseudo-const. */
3871 {
3872 /* ARM $12.6.2: [A member initializer list] (or, for an
3873 aggregate, initialization by a brace-enclosed list) is the
3874 only way to initialize non-static const and reference
3875 members. */
3878 }
3879 }
3880 /* A field that is pseudo-const makes the structure likewise. */
3882 {
3887 }
3889 /* Core issue 80: A non-static data member is required to have a
3890 different name from the class iff the class has a
3891 user-declared constructor. */
3896 }
3898 /* Per CWG 2096, a type is a literal type if it is a union, and at least
3899 one of its non-static data members is of non-volatile literal type. */
3903 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3904 it should also define a copy constructor and an assignment operator to
3905 implement the correct copy semantic (deep vs shallow, etc.). As it is
3906 not feasible to check whether the constructors do allocate dynamic memory
3907 and store it within members, we approximate the warning like this:
3909 -- Warn only if there are members which are pointers
3910 -- Warn only if there is a non-trivial constructor (otherwise,
3911 there cannot be memory allocated).
3912 -- Warn only if there is a non-trivial destructor. We assume that the
3913 user at least implemented the cleanup correctly, and a destructor
3914 is needed to free dynamic memory.
3916 This seems enough for practical purposes. */
3918 && pointer_member
3922 {
3924 {
3926 {
3931 }
3937 }
3938 }
3940 /* Non-static data member initializers make the default constructor
3941 non-trivial. */
3943 {
3946 }
3948 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3952 /* Check anonymous struct/anonymous union fields. */
3955 /* We've built up the list of access declarations in reverse order.
3956 Fix that now. */
3958 }
3960 /* If TYPE is an empty class type, records its OFFSET in the table of
3961 OFFSETS. */
3963 static int
3965 {
3966 splay_tree_node n;
3971 /* Record the location of this empty object in OFFSETS. */
3979 type,
3983 }
3985 /* Returns nonzero if TYPE is an empty class type and there is
3986 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3988 static int
3990 {
3991 splay_tree_node n;
3992 tree t;
3997 /* Record the location of this empty object in OFFSETS. */
4007 }
4009 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
4010 F for every subobject, passing it the type, offset, and table of
4011 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
4012 be traversed.
4014 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
4015 than MAX_OFFSET will not be walked.
4017 If F returns a nonzero value, the traversal ceases, and that value
4018 is returned. Otherwise, returns zero. */
4020 static int
4022 subobject_offset_fn f,
4023 tree offset,
4024 splay_tree offsets,
4025 tree max_offset,
4027 {
4031 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
4032 stop. */
4040 {
4043 }
4046 {
4047 tree field;
4048 tree binfo;
4051 /* Avoid recursing into objects that are not interesting. */
4055 /* Record the location of TYPE. */
4060 /* Iterate through the direct base classes of TYPE. */
4064 {
4065 tree binfo_offset;
4070 tree orig_binfo;
4071 /* We cannot rely on BINFO_OFFSET being set for the base
4072 class yet, but the offsets for direct non-virtual
4073 bases can be calculated by going back to the TYPE. */
4076 offset,
4080 f,
4081 binfo_offset,
4082 offsets,
4083 max_offset,
4087 }
4090 {
4094 /* Iterate through the virtual base classes of TYPE. In G++
4095 3.2, we included virtual bases in the direct base class
4096 loop above, which results in incorrect results; the
4097 correct offsets for virtual bases are only known when
4098 working with the most derived type. */
4102 {
4104 f,
4106 offset,
4108 offsets,
4109 max_offset,
4113 }
4114 else
4115 {
4116 /* We still have to walk the primary base, if it is
4117 virtual. (If it is non-virtual, then it was walked
4118 above.) */
4124 {
4125 r = (walk_subobject_offsets
4130 }
4131 }
4132 }
4134 /* Iterate through the fields of TYPE. */
4139 {
4140 tree field_offset;
4145 f,
4147 offset,
4148 field_offset),
4149 offsets,
4150 max_offset,
4154 }
4155 }
4157 {
4160 tree index;
4162 /* Avoid recursing into objects that are not interesting. */
4165 || !domain
4169 /* Step through each of the elements in the array. */
4173 {
4175 f,
4176 offset,
4177 offsets,
4178 max_offset,
4184 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4185 there's no point in iterating through the remaining
4186 elements of the array. */
4189 }
4190 }
4193 }
4195 /* Return true iff FIELD_DECL DECL is potentially overlapping. */
4197 static bool
4199 {
4200 /* Base fields are actually potentially overlapping, but C++ bases go through
4201 a different code path based on binfos, and ObjC++ base fields are laid out
4202 in objc-act, so we don't want layout_class_type to mess with them. */
4204 {
4207 }
4211 }
4213 /* Return true iff DECL is an empty field, either for an empty base or a
4214 [[no_unique_address]] data member. */
4216 bool
4218 {
4226 /* Empty fields should have size zero. */
4230 }
4232 /* Record all of the empty subobjects of DECL_OR_BINFO. */
4234 static void
4236 splay_tree offsets)
4237 {
4242 {
4248 }
4249 else
4250 {
4255 }
4257 tree max_offset;
4258 /* If recording subobjects for a non-static data member or a
4259 non-empty base class, we do not need to record offsets beyond
4260 the size of the biggest empty class. Additional data members
4261 will go at the end of the class. Additional base classes will go
4262 either at offset zero (if empty, in which case they cannot
4263 overlap with offsets past the size of the biggest empty class) or
4264 at the end of the class.
4266 However, if we are placing an empty base class, then we must record
4267 all offsets, as either the empty class is at offset zero (where
4268 other empty classes might later be placed) or at the end of the
4269 class (where other objects might then be placed, so other empty
4270 subobjects might later overlap). */
4274 else
4278 }
4280 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4281 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4282 virtual bases of TYPE are examined. */
4284 static int
4286 tree offset,
4287 splay_tree offsets,
4289 {
4290 splay_tree_node max_node;
4292 /* Get the node in OFFSETS that indicates the maximum offset where
4293 an empty subobject is located. */
4295 /* If there aren't any empty subobjects, then there's no point in
4296 performing this check. */
4302 vbases_p);
4303 }
4305 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4306 non-static data member of the type indicated by RLI. BINFO is the
4307 binfo corresponding to the base subobject, OFFSETS maps offsets to
4308 types already located at those offsets. This function determines
4309 the position of the DECL. */
4311 static void
4313 tree decl,
4314 tree binfo,
4315 splay_tree offsets)
4316 {
4319 tree type;
4322 {
4323 /* For the purposes of determining layout conflicts, we want to
4324 use the class type of BINFO; TREE_TYPE (DECL) will be the
4325 CLASSTYPE_AS_BASE version, which does not contain entries for
4326 zero-sized bases. */
4329 }
4330 else
4331 {
4334 }
4336 /* Try to place the field. It may take more than one try if we have
4337 a hard time placing the field without putting two objects of the
4338 same type at the same address. */
4340 {
4343 /* Place this field. */
4347 /* We have to check to see whether or not there is already
4348 something of the same type at the offset we're about to use.
4349 For example, consider:
4351 struct S {};
4352 struct T : public S { int i; };
4353 struct U : public S, public T {};
4355 Here, we put S at offset zero in U. Then, we can't put T at
4356 offset zero -- its S component would be at the same address
4357 as the S we already allocated. So, we have to skip ahead.
4358 Since all data members, including those whose type is an
4359 empty class, have nonzero size, any overlap can happen only
4360 with a direct or indirect base-class -- it can't happen with
4361 a data member. */
4362 /* In a union, overlap is permitted; all members are placed at
4363 offset zero. */
4368 {
4369 /* Strip off the size allocated to this field. That puts us
4370 at the first place we could have put the field with
4371 proper alignment. */
4374 /* Bump up by the alignment required for the type. */
4375 rli->bitpos
4381 }
4384 {
4385 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4386 the offset wasn't aligned like a pointer when we started to
4387 layout this field, that affects its position. */
4390 {
4393 "alignment of %qD increased in %<-fabi-version=9%> "
4395 else
4398 decl);
4399 }
4401 }
4402 else
4403 /* There was no conflict. We're done laying out this field. */
4405 }
4407 /* Now that we know where it will be placed, update its
4408 BINFO_OFFSET. */
4410 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4411 this point because their BINFO_OFFSET is copied from another
4412 hierarchy. Therefore, we may not need to add the entire
4413 OFFSET. */
4419 }
4421 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4423 static int
4425 tree offset,
4427 {
4429 }
4431 /* Layout the empty base BINFO. EOC indicates the byte currently just
4432 past the end of the class, and should be correctly aligned for a
4433 class of the type indicated by BINFO; OFFSETS gives the offsets of
4434 the empty bases allocated so far. T is the most derived
4435 type. Return nonzero iff we added it at the end. */
4437 static bool
4439 splay_tree offsets)
4440 {
4441 tree alignment;
4445 tree type;
4447 {
4450 }
4451 else
4452 {
4455 }
4457 /* On some platforms (ARM), even empty classes will not be
4458 byte-aligned. */
4463 /* This routine should only be used for empty classes. */
4468 else
4471 /* This is an empty base class. We first try to put it at offset
4472 zero. */
4476 offset,
4477 offsets,
4479 {
4480 /* That didn't work. Now, we move forward from the next
4481 available spot in the class. */
4485 {
4487 offset,
4488 offsets,
4490 /* We finally found a spot where there's no overlap. */
4493 /* There's overlap here, too. Bump along to the next spot. */
4495 }
4496 }
4499 {
4504 }
4506 {
4511 }
4514 /* Adjust BINFO_OFFSET (binfo) to be exactly OFFSET. */
4517 else
4518 {
4522 }
4525 }
4527 /* Build the FIELD_DECL for BASETYPE as a base of T, add it to the chain of
4528 fields at NEXT_FIELD, and return it. */
4530 static tree
4532 {
4533 /* Create the FIELD_DECL. */
4543 /* CLASSTYPE_SIZE is one byte, but the field needs to have size zero. */
4545 else
4546 {
4549 }
4560 /* Add the new FIELD_DECL to the list of fields for T. */
4566 }
4568 /* Layout the base given by BINFO in the class indicated by RLI.
4569 *BASE_ALIGN is a running maximum of the alignments of
4570 any base class. OFFSETS gives the location of empty base
4571 subobjects. T is the most derived type. Return nonzero if the new
4572 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4573 *NEXT_FIELD, unless BINFO is for an empty base class.
4575 Returns the location at which the next field should be inserted. */
4580 {
4585 /* This error is now reported in xref_tag, thus giving better
4586 location information. */
4589 /* Place the base class. */
4591 {
4592 tree decl;
4594 /* The containing class is non-empty because it has a non-empty
4595 base class. */
4598 /* Create the FIELD_DECL. */
4601 /* Try to place the field. It may take more than one try if we
4602 have a hard time placing the field without putting two
4603 objects of the same type at the same address. */
4605 }
4606 else
4607 {
4609 /* A nearly-empty class "has no proper base class that is empty,
4610 not morally virtual, and at an offset other than zero." */
4612 {
4615 /* The check above (used in G++ 3.2) is insufficient because
4616 an empty class placed at offset zero might itself have an
4617 empty base at a nonzero offset. */
4619 empty_base_at_nonzero_offset_p,
4620 size_zero_node,
4625 }
4627 /* We used to not create a FIELD_DECL for empty base classes because of
4628 back end issues with overlapping FIELD_DECLs, but that doesn't seem to
4629 be a problem anymore. We need them to handle initialization of C++17
4630 aggregate bases. */
4632 {
4638 }
4640 /* An empty virtual base causes a class to be non-empty
4641 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4642 here because that was already done when the virtual table
4643 pointer was created. */
4644 }
4646 /* Record the offsets of BINFO and its base subobjects. */
4650 }
4652 /* Layout all of the non-virtual base classes. Record empty
4653 subobjects in OFFSETS. T is the most derived type. Return nonzero
4654 if the type cannot be nearly empty. The fields created
4655 corresponding to the base classes will be inserted at
4656 *NEXT_FIELD. */
4658 static void
4661 {
4662 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4663 subobjects. */
4668 /* The primary base class is always allocated first. */
4671 {
4672 /* We need to walk BINFO_BASE_BINFO to find the access of the primary
4673 base, if it is direct. Indirect base fields are private. */
4676 {
4679 {
4682 }
4683 }
4685 primary_access,
4687 }
4689 /* Now allocate the rest of the bases. */
4691 {
4694 /* The primary base was already allocated above, so we don't
4695 need to allocate it again here. */
4699 /* Virtual bases are added at the end (a primary virtual base
4700 will have already been added). */
4707 }
4708 }
4710 /* Go through the TYPE_FIELDS of T issuing any appropriate
4711 diagnostics, figuring out which methods override which other
4712 methods, and so forth. */
4714 static void
4716 {
4719 {
4725 /* The name of the field is the original field name
4726 Save this in auxiliary field for later overloading. */
4728 {
4732 }
4738 "%<transaction_safe_dynamic%> may only be specified for "
4740 }
4742 /* Check whether the eligible special member functions (P0848) are
4743 user-provided. add_method arranged that the CLASSTYPE_MEMBER_VEC only
4744 has the eligible ones; TYPE_FIELDS also contains ineligible overloads,
4745 which is why this needs to be separate from the loop above. */
4748 {
4750 {
4751 /* P0848: At the end of the definition of a class, overload
4752 resolution is performed among the prospective destructors declared
4753 in that class with an empty argument list to select the destructor
4754 for the class, also known as the selected destructor. The program
4755 is ill-formed if overload resolution fails. */
4756 auto_diagnostic_group d;
4759 }
4762 }
4765 {
4772 }
4775 {
4782 }
4783 }
4785 /* FN is constructor, destructor or operator function. Clone the
4786 declaration to create a NAME'd variant. NEED_VTT_PARM_P and
4787 OMIT_INHERITED_PARMS_P are relevant if it's a cdtor. */
4789 static tree
4792 {
4793 /* Copy the function. */
4795 /* Reset the function name. */
4799 /* Clone constraints. */
4804 /* There's no pending inline data for this function. */
4809 {
4810 /* The base-class destructor is not virtual. */
4813 }
4815 {
4816 /* Set the operator code. */
4820 /* The operator could be virtual. */
4823 }
4828 /* If there was an in-charge parameter, drop it from the function
4829 type. */
4831 {
4834 /* Skip the `this' parameter. */
4836 /* Skip the in-charge parameter. */
4838 /* And the VTT parm, in a complete [cd]tor. */
4842 {
4843 /* If we're omitting inherited parms, that just leaves the VTT. */
4846 }
4850 parmtypes);
4856 }
4858 /* Copy the function parameters. */
4861 /* Remove the in-charge parameter. */
4863 {
4867 }
4869 /* And the VTT parm, in a complete [cd]tor. */
4871 {
4874 else
4875 {
4879 }
4880 }
4882 /* A base constructor inheriting from a virtual base doesn't get the
4883 arguments. */
4888 {
4891 }
4893 /* Create the RTL for this function. */
4896 /* Regardless of the current scope, this is a member function, so
4897 not at namespace scope. */
4901 }
4903 /* FN is an operator function, create a variant for CODE. */
4905 tree
4907 {
4910 }
4912 /* FN is a constructor or destructor. Clone the declaration to create
4913 a specialized in-charge or not-in-charge version, as indicated by
4914 NAME. */
4916 static tree
4919 {
4920 tree clone;
4922 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4924 {
4936 }
4937 else
4938 {
4942 }
4944 /* Remember where this function came from. */
4947 /* Make it easy to find the CLONE given the FN. Note the
4948 template_result of a template will be chained this way too. */
4953 }
4955 /* Build the clones of FN, return the number of clones built. These
4956 will be inserted onto DECL_CHAIN of FN. */
4958 void
4961 {
4965 {
4966 /* For each constructor, we need two variants: an in-charge version
4967 and a not-in-charge version. */
4970 base_omits_inherited_p);
4972 }
4973 else
4974 {
4977 /* For each destructor, we need three variants: an in-charge
4978 version, a not-in-charge version, and an in-charge deleting
4979 version. We clone the deleting version first because that
4980 means it will go second on the TYPE_FIELDS list -- and that
4981 corresponds to the correct layout order in the virtual
4982 function table.
4984 For a non-virtual destructor, we do not build a deleting
4985 destructor. */
4987 {
4989 count++;
4990 }
4994 }
4996 /* The original is now an abstract function that is never
4997 emitted. */
5002 {
5005 }
5006 }
5008 /* Produce declarations for all appropriate clones of FN. If
5009 UPDATE_METHODS is true, the clones are added to the
5010 CLASSTYPE_MEMBER_VEC. */
5012 void
5014 {
5015 /* Avoid inappropriate cloning. */
5020 /* Base cdtors need a vtt parm if there are virtual bases. */
5023 /* Base ctor omits inherited parms it needs a vttparm and inherited
5024 from a virtual nase ctor. */
5029 }
5031 /* DECL is an in charge constructor, which is being defined. This will
5032 have had an in class declaration, from whence clones were
5033 declared. An out-of-class definition can specify additional default
5034 arguments. As it is the clones that are involved in overload
5035 resolution, we must propagate the information from the DECL to its
5036 clones. */
5038 void
5040 {
5041 tree clone;
5045 {
5050 /* Skip the 'this' parameter. */
5066 {
5068 {
5072 }
5078 {
5079 /* A default parameter has been added. Adjust the
5080 clone's parameters. */
5084 {
5087 clone_parms);
5089 }
5092 tree type
5095 clone_parms);
5103 }
5104 }
5106 }
5107 }
5109 /* For each of the constructors and destructors in T, create an
5110 in-charge and not-in-charge variant. */
5112 static void
5114 {
5115 /* We do not need to propagate the usingness to the clone, at this
5116 point that is not needed. */
5122 }
5124 /* Deduce noexcept for a destructor DTOR. */
5126 void
5128 {
5131 noexcept_deferred_spec);
5132 }
5134 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
5135 of TYPE for virtual functions which FNDECL overrides. Return a
5136 mask of the tm attributes found therein. */
5138 static int
5140 {
5142 tree base_binfo;
5146 {
5154 {
5158 else
5161 }
5162 else
5164 }
5167 }
5169 /* Subroutine of set_method_tm_attributes. Handle the checks and
5170 inheritance for one virtual method FNDECL. */
5172 static void
5174 {
5175 tree tm_attr;
5180 /* If FNDECL doesn't actually override anything (i.e. T is the
5181 class that first declares FNDECL virtual), then we're done. */
5188 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
5189 tm_pure must match exactly, otherwise no weakening of
5190 tm_safe > tm_callable > nothing. */
5191 /* ??? The tm_pure attribute didn't make the transition to the
5192 multivendor language spec. */
5194 {
5196 {
5199 }
5200 }
5201 /* If the overridden function is tm_pure, then FNDECL must be. */
5204 /* Look for base class combinations that cannot be satisfied. */
5206 {
5212 }
5213 /* If FNDECL did not declare an attribute, then inherit the most
5214 restrictive one. */
5216 {
5218 }
5219 /* Otherwise validate that we're not weaker than a function
5220 that is being overridden. */
5221 else
5222 {
5226 }
5229 err_override:
5233 }
5235 /* For each of the methods in T, propagate a class-level tm attribute. */
5237 static void
5239 {
5242 /* Don't bother collecting tm attributes if transactional memory
5243 support is not enabled. */
5247 /* Process virtual methods first, as they inherit directly from the
5248 base virtual function and also require validation of new attributes. */
5250 {
5251 tree vchain;
5254 {
5259 }
5260 }
5262 /* If the class doesn't have an attribute, nothing more to do. */
5267 /* Any method that does not yet have a tm attribute inherits
5268 the one from the class. */
5273 }
5275 /* Returns true if FN is a default constructor. */
5277 bool
5279 {
5282 }
5284 /* Returns true iff class T has a user-provided constructor that can be called
5285 with more than zero arguments. */
5287 bool
5289 {
5294 {
5300 }
5303 }
5305 /* Returns the defaulted constructor if T has one. Otherwise, returns
5306 NULL_TREE. */
5308 tree
5310 {
5315 {
5321 }
5324 }
5326 /* Returns true iff FN is a user-provided function, i.e. user-declared
5327 and not defaulted at its first declaration. */
5329 bool
5331 {
5336 }
5338 /* Returns true iff class T has a user-provided constructor. */
5340 bool
5342 {
5354 }
5356 /* Returns true iff class T has a user-provided or explicit constructor. */
5358 bool
5360 {
5368 {
5372 }
5375 }
5377 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5378 declared or explicitly defaulted in the class body) default
5379 constructor. */
5381 bool
5383 {
5390 {
5396 }
5399 }
5401 /* TYPE is being used as a virtual base, and has a non-trivial move
5402 assignment. Return true if this is due to there being a user-provided
5403 move assignment in TYPE or one of its subobjects; if there isn't, then
5404 multiple move assignment can't cause any harm. */
5406 bool
5408 {
5409 /* Does the type itself have a user-provided move assignment operator? */
5417 /* Do any of its bases? */
5419 tree base_binfo;
5424 /* Or non-static data members? */
5426 {
5431 }
5433 /* Seems not. */
5435 }
5437 /* If default-initialization leaves part of TYPE uninitialized, returns
5438 a DECL for the field or TYPE itself (DR 253). */
5440 tree
5442 {
5453 {
5457 }
5462 {
5466 }
5469 }
5471 /* Returns true iff for class T, a trivial synthesized default constructor
5472 would be constexpr. */
5474 bool
5476 {
5477 /* A defaulted trivial default constructor is constexpr
5478 if there is nothing to initialize. */
5480 /* A class with a vptr doesn't have a trivial default ctor.
5481 In C++20, a class can have transient uninitialized members, e.g.:
5483 struct S { int i; constexpr S() = default; };
5485 should work. */
5488 }
5490 /* Returns true iff class T has a constexpr default constructor. */
5492 bool
5494 {
5495 tree fns;
5498 {
5499 /* The caller should have stripped an enclosing array. */
5502 }
5504 {
5507 /* Non-trivial, we need to check subobject constructors. */
5509 }
5512 }
5514 /* Returns true iff class T has a constexpr default constructor or has an
5515 implicitly declared default constructor that we can't tell if it's constexpr
5516 without forcing a lazy declaration (which might cause undesired
5517 instantiations). */
5519 static bool
5521 {
5524 /* Assume it's constexpr. */
5527 }
5529 /* Returns true iff class T has a constexpr destructor. */
5531 bool
5533 {
5534 tree fns;
5537 /* Non-trivial, we need to check subobject destructors. */
5541 }
5543 /* Returns true iff class T has a constexpr destructor or has an
5544 implicitly declared destructor that we can't tell if it's constexpr
5545 without forcing a lazy declaration (which might cause undesired
5546 instantiations). */
5548 static bool
5550 {
5552 /* Assume it's constexpr. */
5555 }
5557 /* Returns true iff class TYPE has a virtual destructor. */
5559 bool
5561 {
5562 tree dtor;
5570 }
5572 /* Returns true iff T, a class, has a move-assignment or
5573 move-constructor. Does not lazily declare either.
5574 If USER_P is false, any move function will do. If it is true, the
5575 move function must be user-declared.
5577 Note that user-declared here is different from "user-provided",
5578 which doesn't include functions that are defaulted in the
5579 class. */
5581 bool
5583 {
5603 }
5605 /* True iff T has a move constructor that is not deleted. */
5607 bool
5609 {
5616 }
5618 /* If T, a class, has a user-provided copy constructor, copy assignment
5619 operator, or destructor, returns that function. Otherwise, null. */
5621 tree
5623 {
5626 {
5630 }
5636 {
5641 }
5644 {
5648 }
5651 }
5653 /* True iff T has a member or friend declaration of operator OP. */
5655 bool
5657 {
5665 }
5668 /* If T has a defaulted member or friend declaration of OP, return it. */
5670 tree
5672 {
5675 {
5679 }
5683 {
5687 }
5689 }
5691 /* Nonzero if we need to build up a constructor call when initializing an
5692 object of this class, either because it has a user-declared constructor
5693 or because it doesn't have a default constructor (so we need to give an
5694 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5695 what you care about is whether or not an object can be produced by a
5696 constructor (e.g. so we don't set TREE_READONLY on const variables of
5697 such type); use this function when what you care about is whether or not
5698 to try to call a constructor to create an object. The latter case is
5699 the former plus some cases of constructors that cannot be called. */
5701 bool
5703 {
5704 tree inner;
5714 /* A user-declared constructor might be private, and a constructor might
5715 be trivial but deleted. */
5718 {
5725 }
5727 }
5729 /* Like type_build_ctor_call, but for destructors. */
5731 bool
5733 {
5734 tree inner;
5743 /* A user-declared destructor might be private, and a destructor might
5744 be trivial but deleted. */
5747 {
5754 }
5756 }
5758 /* Returns TRUE iff we need a cookie when dynamically allocating an
5759 array whose elements have the indicated class TYPE. */
5761 static bool
5763 {
5764 tree fns;
5769 /* If there's a non-trivial destructor, we need a cookie. In order
5770 to iterate through the array calling the destructor for each
5771 element, we'll have to know how many elements there are. */
5775 /* If the usual deallocation function is a two-argument whose second
5776 argument is of type `size_t', then we have to pass the size of
5777 the array to the deallocation function, so we will need to store
5778 a cookie. */
5782 /* If there are no `operator []' members, or the lookup is
5783 ambiguous, then we don't need a cookie. */
5786 /* Loop through all of the functions. */
5788 {
5791 /* See if this function is a one-argument delete function. If
5792 it is, then it will be the usual deallocation function. */
5796 /* Do not consider this function if its second argument is an
5797 ellipsis. */
5800 /* Otherwise, if we have a two-argument function and the second
5801 argument is `size_t', it will be the usual deallocation
5802 function -- unless there is one-argument function, too. */
5806 }
5809 }
5811 /* Finish computing the `literal type' property of class type T.
5813 At this point, we have already processed base classes and
5814 non-static data members. We need to check whether the copy
5815 constructor is trivial, the destructor is trivial, and there
5816 is a trivial default constructor or at least one constexpr
5817 constructor other than the copy constructor. */
5819 static void
5821 {
5822 tree fn;
5837 /* C++14 DR 1684 removed this restriction. */
5845 {
5848 {
5849 auto_diagnostic_group d;
5851 "enclosing class of %<constexpr%> non-static "
5854 }
5855 }
5856 }
5858 /* T is a non-literal type used in a context which requires a constant
5859 expression. Explain why it isn't literal. */
5861 void
5863 {
5873 /* Already explained. */
5876 auto_diagnostic_group d;
5880 " %qT is a closure type, which is only literal in "
5887 t);
5892 {
5894 " %q+T is not an aggregate, does not have a trivial "
5895 "default constructor, and has no %<constexpr%> constructor that "
5898 /* Note that we can't simply call locate_ctor because when the
5899 constructor is deleted it just returns NULL_TREE. */
5901 {
5908 {
5911 else
5914 }
5915 }
5916 }
5917 else
5918 {
5922 {
5925 {
5931 }
5932 }
5934 {
5935 tree ftype;
5940 {
5943 field);
5946 }
5950 }
5951 }
5952 }
5954 /* Check the validity of the bases and members declared in T. Add any
5955 implicitly-generated functions (like copy-constructors and
5956 assignment operators). Compute various flag bits (like
5957 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5958 level: i.e., independently of the ABI in use. */
5960 static void
5962 {
5963 /* Nonzero if the implicitly generated copy constructor should take
5964 a non-const reference argument. */
5966 /* Nonzero if the implicitly generated assignment operator
5967 should take a non-const reference argument. */
5969 tree access_decls;
5972 tree fn;
5974 /* By default, we use const reference arguments and generate default
5975 constructors. */
5979 /* Check all the base-classes and set FMEM members to point to arrays
5980 of potential interest. */
5983 /* Deduce noexcept on destructor. This needs to happen after we've set
5984 triviality flags appropriately for our bases. */
5989 /* Check all the method declarations. */
5992 /* Save the initial values of these flags which only indicate whether
5993 or not the class has user-provided functions. As we analyze the
5994 bases and members we can set these flags for other reasons. */
5998 /* Check all the data member declarations. We cannot call
5999 check_field_decls until we have called check_bases check_methods,
6000 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
6001 being set appropriately. */
6006 /* A nearly-empty class has to be vptr-containing; a nearly empty
6007 class contains just a vptr. */
6011 /* Do some bookkeeping that will guide the generation of implicitly
6012 declared member functions. */
6015 /* We need to call a constructor for this class if it has a
6016 user-provided constructor, or if the default constructor is going
6017 to initialize the vptr. (This is not an if-and-only-if;
6018 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
6019 themselves need constructing.) */
6022 /* [dcl.init.aggr]
6024 An aggregate is an array or a class with no user-provided
6025 constructors ... and no virtual functions.
6027 Again, other conditions for being an aggregate are checked
6028 elsewhere. */
6034 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
6035 retain the old definition internally for ABI reasons. */
6044 /* If the only explicitly declared default constructor is user-provided,
6045 set TYPE_HAS_COMPLEX_DFLT. */
6051 /* Warn if a public base of a polymorphic type has an accessible
6052 non-virtual destructor. It is only now that we know the class is
6053 polymorphic. Although a polymorphic base will have a already
6054 been diagnosed during its definition, we warn on use too. */
6056 {
6059 tree base_binfo;
6063 {
6071 basetype);
6072 }
6073 }
6075 /* If the class has no user-declared constructor, but does have
6076 non-static const or reference data members that can never be
6077 initialized, issue a warning. */
6079 /* Classes with user-declared constructors are presumed to
6080 initialize these members. */
6082 /* Aggregates can be initialized with brace-enclosed
6083 initializers. */
6085 {
6086 tree field;
6089 {
6090 tree type;
6107 }
6108 }
6110 /* Synthesize any needed methods. */
6112 cant_have_const_ctor,
6113 no_const_asn_ref);
6115 /* Check defaulted declarations here so we have cant_have_const_ctor
6116 and don't need to worry about clones. */
6121 {
6122 /* ...except handle comparisons later, in finish_struct_1. */
6128 {
6129 bool imp_const_p
6135 /* If the function is defaulted outside the class, we just
6136 give the synthesis error. Core Issue #1331 says this is
6137 no longer ill-formed, it is defined as deleted instead. */
6139 }
6141 }
6144 /* "This class type is not an aggregate." */
6147 /* Compute the 'literal type' property before we
6148 do anything with non-static member functions. */
6151 /* Create the in-charge and not-in-charge variants of constructors
6152 and destructors. */
6155 /* Process the using-declarations. */
6159 /* Figure out whether or not we will need a cookie when dynamically
6160 allocating an array of this type. */
6163 }
6165 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
6166 accordingly. If a new vfield was created (because T doesn't have a
6167 primary base class), then the newly created field is returned. It
6168 is not added to the TYPE_FIELDS list; it is the caller's
6169 responsibility to do that. Accumulate declared virtual functions
6170 on VIRTUALS_P. */
6172 static tree
6174 {
6175 tree fn;
6177 /* Collect the virtual functions declared in T. */
6182 {
6191 }
6193 /* If we couldn't find an appropriate base class, create a new field
6194 here. Even if there weren't any new virtual functions, we might need a
6195 new virtual function table if we're supposed to include vptrs in
6196 all classes that need them. */
6198 {
6199 /* We build this decl with vtbl_ptr_type_node, which is a
6200 `vtable_entry_type*'. It might seem more precise to use
6201 `vtable_entry_type (*)[N]' where N is the number of virtual
6202 functions. However, that would require the vtable pointer in
6203 base classes to have a different type than the vtable pointer
6204 in derived classes. We could make that happen, but that
6205 still wouldn't solve all the problems. In particular, the
6206 type-based alias analysis code would decide that assignments
6207 to the base class vtable pointer can't alias assignments to
6208 the derived class vtable pointer, since they have different
6209 types. Thus, in a derived class destructor, where the base
6210 class constructor was inlined, we could generate bad code for
6211 setting up the vtable pointer.
6213 Therefore, we use one type for all vtable pointers. We still
6214 use a type-correct type; it's just doesn't indicate the array
6215 bounds. That's better than using `void*' or some such; it's
6216 cleaner, and it let's the alias analysis code know that these
6217 stores cannot alias stores to void*! */
6218 tree field;
6231 /* This class is non-empty. */
6235 }
6238 }
6240 /* Add OFFSET to all base types of BINFO which is a base in the
6241 hierarchy dominated by T.
6243 OFFSET, which is a type offset, is number of bytes. */
6245 static void
6247 {
6249 tree primary_binfo;
6250 tree base_binfo;
6252 /* Update BINFO's offset. */
6257 offset));
6259 /* Find the primary base class. */
6265 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
6266 downwards. */
6268 {
6269 /* Don't do the primary base twice. */
6277 }
6278 }
6280 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6281 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6282 empty subobjects of T. */
6284 static void
6286 {
6287 tree vbase;
6294 /* Find the last field. The artificial fields created for virtual
6295 bases will go after the last extant field to date. */
6300 /* Go through the virtual bases, allocating space for each virtual
6301 base that is not already a primary base class. These are
6302 allocated in inheritance graph order. */
6304 {
6309 {
6310 /* This virtual base is not a primary base of any class in the
6311 hierarchy, so we have to add space for it. */
6313 access_private_node,
6315 }
6316 }
6317 }
6319 /* Returns the offset of the byte just past the end of the base class
6320 BINFO. */
6322 static tree
6324 {
6325 tree size;
6330 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6331 allocate some space for it. It cannot have virtual bases, so
6332 TYPE_SIZE_UNIT is fine. */
6334 else
6338 }
6340 /* Returns the offset of the byte just past the end of the base class or empty
6341 data member with the highest offset in T. If INCLUDE_VIRTUALS_P is zero,
6342 then only non-virtual bases are included. */
6344 static tree
6346 {
6349 tree binfo;
6350 tree base_binfo;
6351 tree offset;
6356 {
6366 }
6368 /* Also consider empty data members. */
6374 {
6375 /* Update sizeof(C) to max (sizeof(C), offset(D)+sizeof(D)) */
6380 }
6385 {
6389 }
6392 }
6394 /* Warn about bases of T that are inaccessible because they are
6395 ambiguous. For example:
6397 struct S {};
6398 struct T : public S {};
6399 struct U : public S, public T {};
6401 Here, `(S*) new U' is not allowed because there are two `S'
6402 subobjects of U. */
6404 static void
6406 {
6409 tree basetype;
6410 tree binfo;
6411 tree base_binfo;
6413 /* If not checking for warning then return early. */
6417 /* If there are no repeated bases, nothing can be ambiguous. */
6421 /* Check direct bases. */
6424 {
6430 }
6432 /* Check for ambiguous virtual bases. */
6436 {
6442 }
6443 }
6445 /* Compare two INTEGER_CSTs K1 and K2. */
6447 static int
6449 {
6451 }
6453 /* Increase the size indicated in RLI to account for empty classes
6454 that are "off the end" of the class. */
6456 static void
6458 {
6459 tree eoc;
6460 tree rli_size;
6462 /* It might be the case that we grew the class to allocate a
6463 zero-sized base class. That won't be reflected in RLI, yet,
6464 because we are willing to overlay multiple bases at the same
6465 offset. However, now we need to make sure that RLI is big enough
6466 to reflect the entire class. */
6471 {
6472 /* The size should have been rounded to a whole byte. */
6475 rli->bitpos
6484 }
6485 }
6487 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6488 BINFO_OFFSETs for all of the base-classes. Position the vtable
6489 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6491 static void
6493 {
6494 tree non_static_data_members;
6495 tree field;
6496 tree vptr;
6497 record_layout_info rli;
6498 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6499 types that appear at that offset. */
6500 splay_tree empty_base_offsets;
6501 /* True if the last field laid out was a bit-field. */
6503 /* The location at which the next field should be inserted. */
6506 /* Keep track of the first non-static data member. */
6509 /* Start laying out the record. */
6512 /* Mark all the primary bases in the hierarchy. */
6515 /* Create a pointer to our virtual function table. */
6518 /* The vptr is always the first thing in the class. */
6520 {
6525 }
6526 else
6529 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6534 /* Layout the non-static data members. */
6536 {
6537 tree type;
6538 tree padding;
6540 /* We still pass things that aren't non-static data members to
6541 the back end, in case it wants to do something with them. */
6543 {
6545 /* If the static data member has incomplete type, keep track
6546 of it so that it can be completed later. (The handling
6547 of pending statics in finish_record_layout is
6548 insufficient; consider:
6550 struct S1;
6551 struct S2 { static S1 s1; };
6553 At this point, finish_record_layout will be called, but
6554 S1 is still incomplete.) */
6556 {
6558 /* The visibility of static data members is determined
6559 at their point of declaration, not their point of
6560 definition. */
6562 }
6564 }
6576 {
6577 /* if D is a potentially-overlapping data member, update sizeof(C) to
6578 max (sizeof(C), offset(D)+max (nvsize(D), dsize(D))). */
6580 /* end_of_class doesn't always give dsize, but it does in the case of
6581 a class with virtual bases, which is when dsize > nvsize. */
6586 {
6589 }
6590 else
6591 {
6594 }
6595 }
6597 /* If this field is a bit-field whose width is greater than its
6598 type, then there are some special rules for allocating
6599 it. */
6602 {
6604 /* We must allocate the bits as if suitably aligned for the
6605 longest integer type that fits in this many bits. Then,
6606 we are supposed to use the left over bits as additional
6607 padding. */
6609 /* Do not pick a type bigger than MAX_FIXED_MODE_SIZE. */
6617 {
6619 /* Too big, so our current guess is what we want. */
6621 /* Not bigger than limit, ok */
6623 }
6625 /* Figure out how much additional padding is required. */
6627 /* In a union, the padding field must have the full width
6628 of the bit-field; all fields start at offset zero. */
6630 else
6637 /* An unnamed bitfield does not normally affect the
6638 alignment of the containing class on a target where
6639 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6640 make any exceptions for unnamed bitfields when the
6641 bitfields are longer than their types. Therefore, we
6642 temporarily give the field a name. */
6644 {
6647 }
6653 empty_base_offsets);
6656 /* Now that layout has been performed, set the size of the
6657 field to the size of its declared type; the rest of the
6658 field is effectively invisible. */
6660 /* We must also reset the DECL_MODE of the field. */
6662 }
6664 {
6667 }
6668 else
6670 empty_base_offsets);
6672 /* Remember the location of any empty classes in FIELD. */
6675 /* If a bit-field does not immediately follow another bit-field,
6676 and yet it starts in the middle of a byte, we have failed to
6677 comply with the ABI. */
6680 /* The TREE_NO_WARNING flag gets set by Objective-C when
6681 laying out an Objective-C class. The ObjC ABI differs
6682 from the C++ ABI, and so we do not want a warning
6683 here. */
6685 && !last_field_was_bitfield
6688 bitsize_unit_node)))
6690 "offset of %qD is not ABI-compliant and may "
6693 /* The middle end uses the type of expressions to determine the
6694 possible range of expression values. In order to optimize
6695 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6696 must be made aware of the width of "i", via its type.
6698 Because C++ does not have integer types of arbitrary width,
6699 we must (for the purposes of the front end) convert from the
6700 type assigned here to the declared type of the bitfield
6701 whenever a bitfield expression is used as an rvalue.
6702 Similarly, when assigning a value to a bitfield, the value
6703 must be converted to the type given the bitfield here. */
6705 {
6710 {
6717 }
6718 }
6720 /* If we needed additional padding after this field, add it
6721 now. */
6723 {
6724 tree padding_field;
6727 FIELD_DECL,
6728 NULL_TREE,
6729 char_type_node);
6737 NULL_TREE,
6738 empty_base_offsets);
6739 }
6742 }
6745 {
6746 /* Make sure that we are on a byte boundary so that the size of
6747 the class without virtual bases will always be a round number
6748 of bytes. */
6751 }
6753 /* We used to remove zero width bitfields at this point since PR42217,
6754 while the C FE never did that. That caused ABI differences on various
6755 targets. Set the DECL_FIELD_CXX_ZERO_WIDTH_BIT_FIELD flag on them
6756 instead, so that the backends can emit -Wpsabi warnings in the cases
6757 where the ABI changed. */
6761 /* We should not be confused by the fact that grokbitfield
6762 temporarily sets the width of the bit field into
6763 DECL_BIT_FIELD_REPRESENTATIVE (field).
6764 check_bitfield_decl eventually sets DECL_SIZE (field)
6765 to that width. */
6771 {
6772 /* T needs a different layout as a base (eliding virtual bases
6773 or whatever). Create that version. */
6782 /* If the ABI version is not at least two, and the last
6783 field was a bit-field, RLI may not be on a byte
6784 boundary. In particular, rli_size_unit_so_far might
6785 indicate the last complete byte, while rli_size_so_far
6786 indicates the total number of bits used. Therefore,
6787 rli_size_so_far, rather than rli_size_unit_so_far, is
6788 used to compute TYPE_SIZE_UNIT. */
6790 /* Set the size and alignment for the new type. */
6798 eoc);
6810 /* Copy the non-static data members of T. This will include its
6811 direct non-virtual bases & vtable. */
6815 {
6817 /* Zap any NSDMI, it's not needed and might be a deferred
6818 parse. */
6822 }
6825 /* We use the base type for trivial assignments, and hence it
6826 needs a mode. */
6829 /* Record the base version of the type. */
6831 }
6832 else
6835 /* Every empty class contains an empty class. */
6839 /* Set the TYPE_DECL for this type to contain the right
6840 value for DECL_OFFSET, so that we can use it as part
6841 of a COMPONENT_REF for multiple inheritance. */
6844 /* Now fix up any virtual base class types that we left lying
6845 around. We must get these done before we try to lay out the
6846 virtual function table. As a side-effect, this will remove the
6847 base subobject fields. */
6850 /* Make sure that empty classes are reflected in RLI at this
6851 point. */
6854 /* Make sure not to create any structures with zero size. */
6860 /* If this is a non-POD, declaring it packed makes a difference to how it
6861 can be used as a field; don't let finalize_record_size undo it. */
6865 /* Let the back end lay out the type. */
6868 /* If we didn't end up needing an as-base type, don't use it. */
6870 /* If T's CLASSTYPE_AS_BASE is TYPE_USER_ALIGN, but T is not,
6871 replacing the as-base type would change CLASSTYPE_USER_ALIGN,
6872 causing us to lose the user-specified alignment as in PR94050. */
6884 /* Warn about bases that can't be talked about due to ambiguity. */
6887 /* Now that we're done with layout, give the base fields the real types. */
6892 /* Clean up. */
6899 }
6901 /* Determine the "key method" for the class type indicated by TYPE,
6902 and set CLASSTYPE_KEY_METHOD accordingly. */
6904 void
6906 {
6907 tree method;
6914 /* The key method is the first non-pure virtual function that is not
6915 inline at the point of class definition. On some targets the
6916 key function may not be inline; those targets should not call
6917 this function until the end of the translation unit. */
6923 {
6926 }
6929 }
6931 /* Helper of find_flexarrays. Return true when FLD refers to a non-static
6932 class data member of non-zero size, otherwise false. */
6936 {
6944 {
6948 }
6951 }
6953 /* Used by find_flexarrays and related functions. */
6955 struct flexmems_t
6956 {
6957 /* The first flexible array member or non-zero array member found
6958 in the order of layout. */
6959 tree array;
6960 /* First non-static non-empty data member in the class or its bases. */
6961 tree first;
6962 /* The first non-static non-empty data member following either
6963 the flexible array member, if found, or the zero-length array member
6964 otherwise. AFTER[1] refers to the first such data member of a union
6965 of which the struct containing the flexible array member or zero-length
6966 array is a member, or NULL when no such union exists. This element is
6967 only used during searching, not for diagnosing problems. AFTER[0]
6968 refers to the first such data member that is not a member of such
6969 a union. */
6972 /* Refers to a struct (not union) in which the struct of which the flexible
6973 array is member is defined. Used to diagnose strictly (according to C)
6974 invalid uses of the latter structs. */
6975 tree enclosing;
6976 };
6978 /* Find either the first flexible array member or the first zero-length
6979 array, in that order of preference, among members of class T (but not
6980 its base classes), and set members of FMEM accordingly.
6981 BASE_P is true if T is a base class of another class.
6982 PUN is set to the outermost union in which the flexible array member
6983 (or zero-length array) is defined if one such union exists, otherwise
6984 to NULL.
6985 Similarly, PSTR is set to a data member of the outermost struct of
6986 which the flexible array is a member if one such struct exists,
6987 otherwise to NULL. */
6989 static void
6993 {
6994 /* Set the "pointer" to the outermost enclosing union if not set
6995 yet and maintain it for the remainder of the recursion. */
7000 {
7004 /* Is FLD a typedef for an anonymous struct? */
7006 /* FIXME: Note that typedefs (as well as arrays) need to be fully
7007 handled elsewhere so that errors like the following are detected
7008 as well:
7009 typedef struct { int i, a[], j; } S; // bug c++/72753
7010 S s [2]; // bug c++/68489
7011 */
7016 {
7017 /* Check the nested unnamed type referenced via a typedef
7018 independently of FMEM (since it's not a data member of
7019 the enclosing class). */
7022 }
7024 /* Skip anything that's GCC-generated or not a (non-static) data
7025 member. */
7029 /* Type of the member. */
7034 /* Determine the type of the array element or object referenced
7035 by the member so that it can be checked for flexible array
7036 members if it hasn't been yet. */
7043 {
7045 {
7046 /* Once the member after the flexible array has been found
7047 we're done. */
7050 }
7053 {
7054 /* Descend into the non-static member struct or union and try
7055 to find a flexible array member or zero-length array among
7056 its members. This is only necessary for anonymous types
7057 and types in whose context the current type T has not been
7058 defined (the latter must not be checked again because they
7059 are already in the process of being checked by one of the
7060 recursive calls). */
7065 /* If this member isn't anonymous and a prior non-flexible array
7066 member has been seen in one of the enclosing structs, clear
7067 the FIRST member since it doesn't contribute to the flexible
7068 array struct's members. */
7079 {
7080 /* Restore the FIRST member reset above if no flexible
7081 array member has been found in this member's struct. */
7083 }
7085 /* If the member struct contains the first flexible array
7086 member, or if this member is a base class, continue to
7087 the next member and avoid setting the FMEM->NEXT pointer
7088 to point to it. */
7091 }
7092 }
7095 {
7096 /* Remember the first non-static data member. */
7100 /* Remember the first non-static data member after the flexible
7101 array member, if one has been found, or the zero-length array
7102 if it has been found. */
7105 }
7107 /* Skip non-arrays. */
7111 /* Determine the upper bound of the array if it has one. */
7113 {
7115 {
7116 /* Make a record of the zero-length array if either one
7117 such field or a flexible array member has been seen to
7118 handle the pathological and unlikely case of multiple
7119 such members. */
7122 }
7124 {
7125 /* Remember the first zero-length array unless a flexible array
7126 member has already been seen. */
7129 }
7130 }
7131 else
7132 {
7133 /* Flexible array members have no upper bound. */
7135 {
7137 {
7138 /* Replace the zero-length array if it's been stored and
7139 reset the after pointer. */
7143 }
7145 /* Make a record of another flexible array member. */
7147 }
7148 else
7149 {
7152 }
7153 }
7154 }
7155 }
7157 /* Diagnose a strictly (by the C standard) invalid use of a struct with
7158 a flexible array member (or the zero-length array extension). */
7160 static void
7162 {
7164 {
7165 auto_diagnostic_group d;
7176 }
7177 }
7179 /* Issue diagnostics for invalid flexible array members or zero-length
7180 arrays that are not the last elements of the containing class or its
7181 base classes or that are its sole members. */
7183 static void
7185 {
7190 {
7193 }
7195 /* Has a diagnostic been issued? */
7201 {
7208 {
7211 auto_diagnostic_group d;
7213 {
7216 }
7217 }
7218 }
7219 else
7220 {
7227 {
7231 auto_diagnostic_group d;
7234 /* In the unlikely event that the member following the flexible
7235 array member is declared in a different class, or the member
7236 overlaps another member of a common union, point to it.
7237 Otherwise it should be obvious. */
7241 {
7246 }
7247 }
7248 }
7252 }
7255 /* Recursively check to make sure that any flexible array or zero-length
7256 array members of class T or its bases are valid (i.e., not the sole
7257 non-static data member of T and, if one exists, that it is the last
7258 non-static data member of T and its base classes. FMEM is expected
7259 to be initially null and is used internally by recursive calls to
7260 the function. Issue the appropriate diagnostics for the array member
7261 that fails the checks. */
7263 static void
7266 {
7267 /* Initialize the result of a search for flexible array and zero-length
7268 array members. Avoid doing any work if the most interesting FMEM data
7269 have already been populated. */
7278 /* Recursively check the primary base class first. */
7280 {
7283 }
7285 /* Recursively check the base classes. */
7288 {
7291 /* The primary base class was already checked above. */
7295 /* Virtual base classes are at the end. */
7299 /* Check the base class. */
7301 }
7304 {
7305 /* Check virtual base classes only once per derived class.
7306 I.e., this check is not performed recursively for base
7307 classes. */
7309 tree base_binfo;
7313 {
7314 /* Check the virtual base class. */
7318 }
7319 }
7321 /* Is the type unnamed (and therefore a member of it potentially
7322 an anonymous struct or union)? */
7327 /* Search the members of the current (possibly derived) class, skipping
7328 unnamed structs and unions since those could be anonymous. */
7333 {
7334 /* Issue diagnostics for invalid flexible and zero-length array
7335 members found in base classes or among the members of the current
7336 class. Ignore anonymous structs and unions whose members are
7337 considered to be members of the enclosing class and thus will
7338 be diagnosed when checking it. */
7340 }
7341 }
7343 /* Perform processing required when the definition of T (a class type)
7344 is complete. Diagnose invalid definitions of flexible array members
7345 and zero-size arrays. */
7347 void
7349 {
7350 tree x;
7351 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
7355 {
7360 }
7362 /* If this type was previously laid out as a forward reference,
7363 make sure we lay it out again. */
7367 /* Make assumptions about the class; we'll reset the flags if
7368 necessary. */
7374 /* Do end-of-class semantic processing: checking the validity of the
7375 bases and members and add implicitly generated methods. */
7378 /* Find the key method. */
7380 {
7381 /* The Itanium C++ ABI permits the key method to be chosen when
7382 the class is defined -- even though the key method so
7383 selected may later turn out to be an inline function. On
7384 some systems (such as ARM Symbian OS) the key method cannot
7385 be determined until the end of the translation unit. On such
7386 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
7387 will cause the class to be added to KEYED_CLASSES. Then, in
7388 finish_file we will determine the key method. */
7392 /* If a polymorphic class has no key method, we may emit the vtable
7393 in every translation unit where the class definition appears. If
7394 we're devirtualizing, we can look into the vtable even if we
7395 aren't emitting it. */
7398 }
7400 /* Layout the class itself. */
7402 /* COMPLETE_TYPE_P is now true. */
7406 /* With the layout complete, check for flexible array members and
7407 zero-length arrays that might overlap other members in the final
7408 layout. */
7413 /* If necessary, create the primary vtable for this class. */
7415 {
7416 /* We must enter these virtuals into the table. */
7420 /* Here we know enough to change the type of our virtual
7421 function table, but we will wait until later this function. */
7424 /* If we're warning about ABI tags, check the types of the new
7425 virtual functions. */
7429 }
7432 {
7434 tree fn;
7441 /* Add entries for virtual functions introduced by this class. */
7445 /* Set DECL_VINDEX for all functions declared in this class. */
7447 fn;
7449 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
7451 {
7455 /* A thunk. We should never be calling this entry directly
7456 from this vtable -- we'd use the entry for the non
7457 thunk base function. */
7461 }
7462 }
7470 /* Clear DECL_IN_AGGR_P for all member functions. Complete the rtl
7471 for any static member objects of the type we're working on. */
7474 {
7475 /* Synthesize constexpr defaulted comparisons. */
7481 }
7487 /* Complain if one of the field types requires lower visibility. */
7490 /* Make the rtl for any new vtables we have created, and unmark
7491 the base types we marked. */
7494 /* Build the VTT for T. */
7501 "%q#T has virtual functions and accessible"
7509 /* Class layout, assignment of virtual table slots, etc., is now
7510 complete. Give the back end a chance to tweak the visibility of
7511 the class or perform any other required target modifications. */
7521 /* Finish debugging output for this type. */
7525 {
7528 {
7531 }
7533 {
7536 else
7537 {
7540 }
7542 }
7544 {
7546 "the type of the first field has a different ABI from the "
7549 }
7550 }
7551 }
7553 /* When T was built up, the member declarations were added in reverse
7554 order. Rearrange them to declaration order. */
7556 void
7558 {
7559 tree next;
7560 tree prev;
7561 tree x;
7563 /* The following lists are all in reverse order. Put them in
7564 declaration order now. */
7567 /* For the TYPE_FIELDS, only the non TYPE_DECLs are in reverse
7568 order, so we can't just use nreverse. Due to stat_hack
7569 chicanery in finish_member_declaration. */
7574 {
7578 }
7581 {
7584 }
7585 }
7587 tree
7589 {
7592 /* Now that we've got all the field declarations, reverse everything
7593 as necessary. */
7599 /* Nadger the current location so that diagnostics point to the start of
7600 the struct, not the end. */
7604 {
7605 tree x;
7607 /* We need to add the target functions of USING_DECLS, so that
7608 they can be found when the using declaration is not
7609 instantiated yet. */
7612 {
7617 }
7619 {
7623 }
7625 {
7628 }
7630 /* Also add a USING_DECL for operator=. We know there'll be (at
7631 least) one, but we don't know the signature(s). We want name
7632 lookup not to fail or recurse into bases. This isn't added
7633 to the template decl list so we drop this at instantiation
7634 time. */
7636 NULL_TREE);
7646 /* COMPLETE_TYPE_P is now true. */
7650 /* We need to emit an error message if this type was used as a parameter
7651 and it is an abstract type, even if it is a template. We construct
7652 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
7653 account and we call complete_vars with this type, which will check
7654 the PARM_DECLS. Note that while the type is being defined,
7655 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
7656 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
7663 /* Remember current #pragma pack value. */
7667 {
7671 }
7675 /* Fix up any variants we've already built. */
7677 }
7678 else
7680 /* COMPLETE_TYPE_P is now true. */
7685 {
7686 /* People keep complaining that the compiler crashes on an invalid
7687 definition of initializer_list, so I guess we should explicitly
7688 reject it. What the compiler internals care about is that it's a
7689 template and has a pointer field followed by size_type field. */
7692 {
7695 {
7699 }
7700 }
7704 }
7712 else
7724 /* Lambdas are defined by the LAMBDA_EXPR. */
7729 }
7730 \f
7731 /* Hash table to avoid endless recursion when handling references. */
7734 /* Return the dynamic type of INSTANCE, if known.
7735 Used to determine whether the virtual function table is needed
7736 or not.
7738 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7739 of our knowledge of its type. *NONNULL should be initialized
7740 before this function is called. */
7742 static tree
7744 {
7745 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7748 {
7752 else
7756 /* This is a call to a constructor, hence it's never zero. */
7759 {
7763 }
7767 /* This is a call to a constructor, hence it's never zero. */
7769 {
7773 }
7782 /* Propagate nonnull. */
7787 CASE_CONVERT:
7793 {
7794 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7795 with a real object -- given &p->f, p can still be null. */
7797 /* ??? Probably should check DECL_WEAK here. */
7800 }
7804 /* If this component is really a base class reference, then the field
7805 itself isn't definitive. */
7814 {
7818 }
7819 /* fall through. */
7824 {
7828 }
7830 {
7834 /* if we're in a ctor or dtor, we know our type. If
7835 current_class_ptr is set but we aren't in a function, we're in
7836 an NSDMI (and therefore a constructor). */
7841 {
7845 }
7846 }
7848 {
7849 /* We only need one hash table because it is always left empty. */
7851 fixed_type_or_null_ref_ht
7854 /* Reference variables should be references to objects. */
7858 /* Enter the INSTANCE in a table to prevent recursion; a
7859 variable's initializer may refer to the variable
7860 itself. */
7865 {
7866 tree type;
7875 }
7876 }
7882 else
7883 /* TODO: Recursion may be correct for some non-location-wrapper
7884 uses of VIEW_CONVERT_EXPR. */
7889 }
7890 #undef RECUR
7891 }
7893 /* Return nonzero if the dynamic type of INSTANCE is known, and
7894 equivalent to the static type. We also handle the case where
7895 INSTANCE is really a pointer. Return negative if this is a
7896 ctor/dtor. There the dynamic type is known, but this might not be
7897 the most derived base of the original object, and hence virtual
7898 bases may not be laid out according to this type.
7900 Used to determine whether the virtual function table is needed
7901 or not.
7903 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7904 of our knowledge of its type. *NONNULL should be initialized
7905 before this function is called. */
7907 int
7909 {
7912 tree fixed;
7914 /* processing_template_decl can be false in a template if we're in
7915 instantiate_non_dependent_expr, but we still want to suppress
7916 this check. */
7918 {
7919 /* In a template we only care about the type of the result. */
7923 }
7935 }
7937 \f
7938 void
7940 {
7943 current_class_stack
7950 }
7952 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7954 static void
7956 {
7957 tree type;
7959 /* We are re-entering the same class we just left, so we don't
7960 have to search the whole inheritance matrix to find all the
7961 decls to bind again. Instead, we install the cached
7962 class_shadowed list and walk through it binding names. */
7965 /* Restore IDENTIFIER_TYPE_VALUE. */
7967 type;
7970 }
7972 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7973 appropriate for TYPE.
7975 So that we may avoid calls to lookup_name, we cache the _TYPE
7976 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7978 For multiple inheritance, we perform a two-pass depth-first search
7979 of the type lattice. */
7981 void
7983 {
7984 class_stack_node_t csn;
7988 /* Make sure there is enough room for the new entry on the stack. */
7990 {
7992 current_class_stack
7994 current_class_stack_size);
7995 }
7997 /* Insert a new entry on the class stack. */
8004 current_class_depth++;
8006 /* Now set up the new type. */
8012 /* By default, things in classes are private, while things in
8013 structures or unions are public. */
8015 ? access_private_node
8021 {
8022 /* Forcibly remove any old class remnants. */
8024 }
8030 else
8032 }
8034 /* Get out of the current class scope. If we were in a class scope
8035 previously, that is the one popped to. */
8037 void
8039 {
8042 current_class_depth--;
8048 }
8050 /* Mark the top of the class stack as hidden. */
8052 void
8054 {
8057 }
8059 /* Mark the top of the class stack as un-hidden. */
8061 void
8063 {
8066 }
8068 /* If the class type currently being defined is either T or
8069 a nested type of T, returns the type from the current_class_stack,
8070 which might be equivalent to but not equal to T in case of
8071 constrained partial specializations. */
8073 tree
8075 {
8083 /* We start looking from 1 because entry 0 is from global scope,
8084 and has no type. */
8086 {
8087 tree c;
8090 else
8091 {
8095 }
8100 }
8102 }
8104 /* If either current_class_type or one of its enclosing classes are derived
8105 from T, return the appropriate type. Used to determine how we found
8106 something via unqualified lookup. */
8108 tree
8110 {
8113 /* The bases of a dependent type are unknown. */
8124 {
8129 }
8132 }
8134 /* Return the outermost enclosing class type that is still open, or
8135 NULL_TREE. */
8137 tree
8139 {
8146 {
8153 }
8155 }
8157 /* Returns the innermost class type which is not a lambda closure type. */
8159 tree
8161 {
8166 }
8168 /* When entering a class scope, all enclosing class scopes' names with
8169 static meaning (static variables, static functions, types and
8170 enumerators) have to be visible. This recursive function calls
8171 pushclass for all enclosing class contexts until global or a local
8172 scope is reached. TYPE is the enclosed class. */
8174 void
8176 {
8177 /* A namespace might be passed in error cases, like A::B:C. */
8185 }
8187 /* Undoes a push_nested_class call. */
8189 void
8191 {
8197 }
8199 /* Returns the number of extern "LANG" blocks we are nested within. */
8201 int
8203 {
8205 }
8207 /* Set global variables CURRENT_LANG_NAME to appropriate value
8208 so that behavior of name-mangling machinery is correct. */
8210 void
8212 {
8219 else
8221 }
8223 /* Get out of the current language scope. */
8225 void
8227 {
8229 }
8230 \f
8231 /* Type instantiation routines. */
8233 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
8234 matches the TARGET_TYPE. If there is no satisfactory match, return
8235 error_mark_node, and issue an error & warning messages under
8236 control of FLAGS. Permit pointers to member function if FLAGS
8237 permits. If TEMPLATE_ONLY, the name of the overloaded function was
8238 a template-id, and EXPLICIT_TARGS are the explicitly provided
8239 template arguments.
8241 If OVERLOAD is for one or more member functions, then ACCESS_PATH
8242 is the base path used to reference those member functions. If
8243 the address is resolved to a member function, access checks will be
8244 performed and errors issued if appropriate. */
8246 static tree
8248 tree overload,
8249 tsubst_flags_t complain,
8251 tree explicit_targs,
8252 tree access_path)
8253 {
8254 /* Here's what the standard says:
8256 [over.over]
8258 If the name is a function template, template argument deduction
8259 is done, and if the argument deduction succeeds, the deduced
8260 arguments are used to generate a single template function, which
8261 is added to the set of overloaded functions considered.
8263 Non-member functions and static member functions match targets of
8264 type "pointer-to-function" or "reference-to-function." Nonstatic
8265 member functions match targets of type "pointer-to-member
8266 function;" the function type of the pointer to member is used to
8267 select the member function from the set of overloaded member
8268 functions. If a non-static member function is selected, the
8269 reference to the overloaded function name is required to have the
8270 form of a pointer to member as described in 5.3.1.
8272 If more than one function is selected, any template functions in
8273 the set are eliminated if the set also contains a non-template
8274 function, and any given template function is eliminated if the
8275 set contains a second template function that is more specialized
8276 than the first according to the partial ordering rules 14.5.5.2.
8277 After such eliminations, if any, there shall remain exactly one
8278 selected function. */
8281 /* We store the matches in a TREE_LIST rooted here. The functions
8282 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
8283 interoperability with most_specialized_instantiation. */
8285 tree fn;
8286 tree target_fn_type;
8288 /* By the time we get here, we should be seeing only real
8289 pointer-to-member types, not the internal POINTER_TYPE to
8290 METHOD_TYPE representation. */
8296 /* Check that the TARGET_TYPE is reasonable. */
8301 /* This is OK, too. */
8304 /* This is OK, too. This comes from a conversion to reference
8305 type. */
8307 else
8308 {
8314 }
8316 /* Non-member functions and static member functions match targets of type
8317 "pointer-to-function" or "reference-to-function." Nonstatic member
8318 functions match targets of type "pointer-to-member-function;" the
8319 function type of the pointer to member is used to select the member
8320 function from the set of overloaded member functions.
8322 So figure out the FUNCTION_TYPE that we want to match against. */
8325 /* If we can find a non-template function that matches, we can just
8326 use it. There's no point in generating template instantiations
8327 if we're just going to throw them out anyhow. But, of course, we
8328 can only do this when we don't *need* a template function. */
8331 {
8335 /* We're not looking for templates just yet. */
8339 /* We're looking for a non-static member, and this isn't
8340 one, or vice versa. */
8343 /* Constraints must be satisfied. This is done before
8344 return type deduction since that instantiates the
8345 function. */
8350 {
8351 /* Force instantiation to do return type deduction. */
8354 }
8356 /* In C++17 we need the noexcept-qualifier to compare types. */
8361 /* See if there's a match. */
8366 }
8368 /* Now, if we've already got a match (or matches), there's no need
8369 to proceed to the template functions. But, if we don't have a
8370 match we need to look at them, too. */
8372 {
8373 tree target_arg_types;
8374 tree target_ret_type;
8377 tree arg;
8391 {
8393 tree instantiation;
8394 tree targs;
8397 /* We're only looking for templates. */
8402 /* We're not looking for a non-static member, and this is
8403 one, or vice versa. */
8408 /* If the template has a deduced return type, don't expose it to
8409 template argument deduction. */
8413 /* Try to do argument deduction. */
8420 /* Instantiation failed. */
8423 /* Constraints must be satisfied. This is done before
8424 return type deduction since that instantiates the
8425 function. */
8429 /* And now force instantiation to do return type deduction. */
8431 {
8437 }
8439 /* In C++17 we need the noexcept-qualifier to compare types. */
8443 /* See if there's a match. */
8448 }
8450 /* Now, remove all but the most specialized of the matches. */
8452 {
8457 NULL_TREE,
8458 NULL_TREE);
8459 }
8460 }
8462 /* Now we should have exactly one function in MATCHES. */
8464 {
8465 /* There were *no* matches. */
8467 {
8472 }
8474 }
8476 {
8477 /* There were too many matches. First check if they're all
8478 the same function. */
8483 /* For multi-versioned functions, more than one match is just fine and
8484 decls_match will return false as they are different. */
8492 {
8494 {
8498 /* Since print_candidates expects the functions in the
8499 TREE_VALUE slot, we flip them here. */
8504 }
8507 }
8508 }
8510 /* Good, exactly one match. Now, convert it to the correct type. */
8515 {
8521 auto_diagnostic_group d;
8524 {
8528 }
8529 }
8531 /* If a pointer to a function that is multi-versioned is requested, the
8532 pointer to the dispatcher function is returned instead. This works
8533 well because indirectly calling the function will dispatch the right
8534 function version at run-time. */
8536 {
8540 /* Mark all the versions corresponding to the dispatcher as used. */
8543 }
8545 /* If we're doing overload resolution purely for the purpose of
8546 determining conversion sequences, we should not consider the
8547 function used. If this conversion sequence is selected, the
8548 function will be marked as used at this point. */
8550 {
8551 /* Make =delete work with SFINAE. */
8556 }
8558 /* We could not check access to member functions when this
8559 expression was originally created since we did not know at that
8560 time to which function the expression referred. */
8562 {
8565 }
8569 else
8570 {
8571 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
8572 will mark the function as addressed, but here we must do it
8573 explicitly. */
8577 }
8578 }
8580 /* This function will instantiate the type of the expression given in
8581 RHS to match the type of LHSTYPE. If errors exist, then return
8582 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
8583 we complain on errors. If we are not complaining, never modify rhs,
8584 as overload resolution wants to try many possible instantiations, in
8585 the hope that at least one will work.
8587 For non-recursive calls, LHSTYPE should be a function, pointer to
8588 function, or a pointer to member function. */
8590 tree
8592 {
8599 {
8603 }
8606 {
8615 /* Microsoft allows `A::f' to be resolved to a
8616 pointer-to-member. */
8617 ;
8618 else
8619 {
8624 }
8625 }
8627 /* If we instantiate a template, and it is a A ?: C expression
8628 with omitted B, look through the SAVE_EXPR. */
8633 {
8636 }
8638 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
8639 deduce any type information. */
8641 {
8645 }
8647 /* There are only a few kinds of expressions that may have a type
8648 dependent on overload resolution. */
8654 /* This should really only be used when attempting to distinguish
8655 what sort of a pointer to function we have. For now, any
8656 arithmetic operation which is not supported on pointers
8657 is rejected as an error. */
8660 {
8662 {
8668 /* Do not lose object's side effects. */
8672 }
8679 /* This can happen if we are forming a pointer-to-member for a
8680 member template. */
8683 /* Fall through. */
8686 {
8690 return
8694 }
8698 return
8702 access_path);
8705 {
8710 }
8717 }
8719 }
8720 \f
8721 /* Return the name of the virtual function pointer field
8722 (as an IDENTIFIER_NODE) for the given TYPE. Note that
8723 this may have to look back through base types to find the
8724 ultimate field name. (For single inheritance, these could
8725 all be the same name. Who knows for multiple inheritance). */
8727 static tree
8729 {
8735 {
8741 }
8749 }
8751 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8752 according to [class]:
8753 The class-name is also inserted
8754 into the scope of the class itself. For purposes of access checking,
8755 the inserted class name is treated as if it were a public member name. */
8757 void
8759 {
8777 }
8779 /* Returns 1 if TYPE contains only padding bytes. */
8781 int
8783 {
8791 }
8793 /* Returns true if TYPE contains no actual data, just various
8794 possible combinations of empty classes. If IGNORE_VPTR is true,
8795 a vptr doesn't prevent the class from being considered empty. Typically
8796 we want to ignore the vptr on assignment, and not on initialization. */
8798 bool
8800 {
8802 {
8803 tree field;
8804 tree binfo;
8805 tree base_binfo;
8808 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8809 out, but we'd like to be able to check this before then. */
8823 /* An unnamed bit-field is not a data member. */
8828 }
8833 }
8835 /* Note that NAME was looked up while the current class was being
8836 defined and that the result of that lookup was DECL. */
8838 void
8840 {
8841 splay_tree names_used;
8843 /* If we're not defining a class, there's nothing to do. */
8849 /* If there's already a binding for this NAME, then we don't have
8850 anything to worry about. */
8863 }
8865 /* Note that NAME was declared (as DECL) in the current class. Check
8866 to see that the declaration is valid. */
8868 void
8870 {
8871 splay_tree names_used;
8872 splay_tree_node n;
8874 /* Look to see if we ever used this name. */
8875 names_used
8879 /* The C language allows members to be declared with a type of the same
8880 name, and the C++ standard says this diagnostic is not required. So
8881 allow it in extern "C" blocks unless predantic is specified.
8882 Allow it in all cases if -ms-extensions is specified. */
8888 {
8889 /* [basic.scope.class]
8891 A name N used in a class S shall refer to the same declaration
8892 in its context and when re-evaluated in the completed scope of
8893 S. */
8900 }
8901 }
8903 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8904 Secondary vtables are merged with primary vtables; this function
8905 will return the VAR_DECL for the primary vtable. */
8907 tree
8909 {
8910 tree decl;
8914 {
8917 }
8921 }
8924 /* Returns the binfo for the primary base of BINFO. If the resulting
8925 BINFO is a virtual base, and it is inherited elsewhere in the
8926 hierarchy, then the returned binfo might not be the primary base of
8927 BINFO in the complete object. Check BINFO_PRIMARY_P or
8928 BINFO_LOST_PRIMARY_P to be sure. */
8930 static tree
8932 {
8933 tree primary_base;
8940 }
8942 /* As above, but iterate until we reach the binfo that actually provides the
8943 vptr for BINFO. */
8945 static tree
8947 {
8951 {
8956 }
8958 }
8960 /* Returns true if BINFO gets its vptr from a virtual base of the most derived
8961 type. Note that the virtual inheritance might be above or below BINFO in
8962 the hierarchy. */
8964 bool
8966 {
8970 /* Don't limit binfo_via_virtual, we want to return true when BINFO itself is
8971 a morally virtual base. */
8974 }
8976 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8978 static int
8980 {
8984 }
8986 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8987 INDENT should be zero when called from the top level; it is
8988 incremented recursively. IGO indicates the next expected BINFO in
8989 inheritance graph ordering. */
8991 static tree
8993 dump_flags_t flags,
8994 tree binfo,
8995 tree igo,
8997 {
8999 tree base_binfo;
9006 {
9009 }
9023 {
9027 TFF_PLAIN_IDENTIFIER),
9029 }
9031 {
9034 }
9039 {
9043 {
9047 TFF_PLAIN_IDENTIFIER));
9048 }
9050 {
9054 TFF_PLAIN_IDENTIFIER));
9055 }
9057 {
9061 TFF_PLAIN_IDENTIFIER));
9062 }
9064 {
9068 TFF_PLAIN_IDENTIFIER));
9069 }
9073 }
9079 }
9081 /* Dump the BINFO hierarchy for T. */
9083 static void
9085 {
9097 }
9099 /* Debug interface to hierarchy dumping. */
9101 void
9103 {
9105 }
9107 static void
9109 {
9110 dump_flags_t flags;
9112 {
9115 }
9116 }
9118 static void
9120 {
9121 tree value;
9123 HOST_WIDE_INT elt;
9131 TFF_PLAIN_IDENTIFIER));
9138 }
9140 static void
9142 {
9143 dump_flags_t flags;
9150 {
9157 {
9162 }
9166 }
9169 }
9171 static void
9173 {
9174 dump_flags_t flags;
9181 {
9186 }
9189 }
9191 /* Dump a function or thunk and its thunkees. */
9193 static void
9195 {
9198 tree thunks;
9206 {
9216 else
9222 }
9226 }
9228 /* Dump the thunks for FN. */
9230 void
9232 {
9234 }
9236 /* Virtual function table initialization. */
9238 /* Create all the necessary vtables for T and its base classes. */
9240 static void
9242 {
9243 tree vbase;
9247 /* We lay out the primary and secondary vtables in one contiguous
9248 vtable. The primary vtable is first, followed by the non-virtual
9249 secondary vtables in inheritance graph order. */
9253 /* Then come the virtual bases, also in inheritance graph order. */
9255 {
9259 }
9263 }
9265 /* Initialize the vtable for BINFO with the INITS. */
9267 static void
9269 {
9270 tree decl;
9276 }
9278 /* Build the VTT (virtual table table) for T.
9279 A class requires a VTT if it has virtual bases.
9281 This holds
9282 1 - primary virtual pointer for complete object T
9283 2 - secondary VTTs for each direct non-virtual base of T which requires a
9284 VTT
9285 3 - secondary virtual pointers for each direct or indirect base of T which
9286 has virtual bases or is reachable via a virtual path from T.
9287 4 - secondary VTTs for each direct or indirect virtual base of T.
9289 Secondary VTTs look like complete object VTTs without part 4. */
9291 static void
9293 {
9294 tree type;
9295 tree vtt;
9296 tree index;
9299 /* Build up the initializers for the VTT. */
9304 /* If we didn't need a VTT, we're done. */
9308 /* Figure out the type of the VTT. */
9312 /* Now, build the VTT object itself. */
9315 /* Add the VTT to the vtables list. */
9320 }
9322 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
9323 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
9324 and CHAIN the vtable pointer for this binfo after construction is
9325 complete. VALUE can also be another BINFO, in which case we recurse. */
9327 static tree
9329 {
9330 tree vt;
9333 {
9339 else
9341 }
9344 }
9346 /* Data for secondary VTT initialization. */
9347 struct secondary_vptr_vtt_init_data
9348 {
9349 /* Is this the primary VTT? */
9352 /* Current index into the VTT. */
9353 tree index;
9355 /* Vector of initializers built up. */
9358 /* The type being constructed by this secondary VTT. */
9359 tree type_being_constructed;
9360 };
9362 /* Recursively build the VTT-initializer for BINFO (which is in the
9363 hierarchy dominated by T). INITS points to the end of the initializer
9364 list to date. INDEX is the VTT index where the next element will be
9365 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
9366 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
9367 for virtual bases of T. When it is not so, we build the constructor
9368 vtables for the BINFO-in-T variant. */
9370 static void
9373 {
9375 tree b;
9376 tree init;
9377 secondary_vptr_vtt_init_data data;
9380 /* We only need VTTs for subobjects with virtual bases. */
9384 /* We need to use a construction vtable if this is not the primary
9385 VTT. */
9387 {
9390 /* Record the offset in the VTT where this sub-VTT can be found. */
9392 }
9394 /* Add the address of the primary vtable for the complete object. */
9398 {
9401 }
9404 /* Recursively add the secondary VTTs for non-virtual bases. */
9409 /* Add secondary virtual pointers for all subobjects of BINFO with
9410 either virtual bases or reachable along a virtual path, except
9411 subobjects that are non-virtual primary bases. */
9421 /* data.inits might have grown as we added secondary virtual pointers.
9422 Make sure our caller knows about the new vector. */
9426 /* Add the secondary VTTs for virtual bases in inheritance graph
9427 order. */
9429 {
9434 }
9435 else
9436 /* Remove the ctor vtables we created. */
9438 }
9440 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
9441 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
9443 static tree
9445 {
9448 /* We don't care about bases that don't have vtables. */
9452 /* We're only interested in proper subobjects of the type being
9453 constructed. */
9457 /* We're only interested in bases with virtual bases or reachable
9458 via a virtual path from the type being constructed. */
9463 /* We're not interested in non-virtual primary bases. */
9467 /* Record the index where this secondary vptr can be found. */
9469 {
9474 {
9475 /* It's a primary virtual base, and this is not a
9476 construction vtable. Find the base this is primary of in
9477 the inheritance graph, and use that base's vtable
9478 now. */
9481 }
9482 }
9484 /* Add the initializer for the secondary vptr itself. */
9487 /* Advance the vtt index. */
9492 }
9494 /* Called from build_vtt_inits via dfs_walk. After building
9495 constructor vtables and generating the sub-vtt from them, we need
9496 to restore the BINFO_VTABLES that were scribbled on. DATA is the
9497 binfo of the base whose sub vtt was generated. */
9499 static tree
9501 {
9505 /* If this class has no vtable, none of its bases do. */
9509 /* This might be a primary base, so have no vtable in this
9510 hierarchy. */
9513 /* If we scribbled the construction vtable vptr into BINFO, clear it
9514 out now. */
9520 }
9522 /* Build the construction vtable group for BINFO which is in the
9523 hierarchy dominated by T. */
9525 static void
9527 {
9528 tree type;
9529 tree vtbl;
9530 tree id;
9531 tree vbase;
9534 /* See if we've already created this construction vtable group. */
9540 /* Build a version of VTBL (with the wrong type) for use in
9541 constructing the addresses of secondary vtables in the
9542 construction vtable group. */
9545 /* Don't export construction vtables from shared libraries. Even on
9546 targets that don't support hidden visibility, this tells
9547 can_refer_decl_in_current_unit_p not to assume that it's safe to
9548 access from a different compilation unit (bz 54314). */
9556 /* Add the vtables for each of our virtual bases using the vbase in T
9557 binfo. */
9559 vbase;
9561 {
9562 tree b;
9569 }
9571 /* Figure out the type of the construction vtable. */
9578 /* Initialize the construction vtable. */
9582 }
9584 /* Add the vtbl initializers for BINFO (and its bases other than
9585 non-virtual primaries) to the list of INITS. BINFO is in the
9586 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
9587 the constructor the vtbl inits should be accumulated for. (If this
9588 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
9589 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
9590 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
9591 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
9592 but are not necessarily the same in terms of layout. */
9594 static void
9596 tree orig_binfo,
9597 tree rtti_binfo,
9598 tree vtbl,
9599 tree t,
9601 {
9603 tree base_binfo;
9608 /* If it doesn't have a vptr, we don't do anything. */
9612 /* If we're building a construction vtable, we're not interested in
9613 subobjects that don't require construction vtables. */
9619 /* Build the initializers for the BINFO-in-T vtable. */
9622 /* Walk the BINFO and its bases. We walk in preorder so that as we
9623 initialize each vtable we can figure out at what offset the
9624 secondary vtable lies from the primary vtable. We can't use
9625 dfs_walk here because we need to iterate through bases of BINFO
9626 and RTTI_BINFO simultaneously. */
9628 {
9629 /* Skip virtual bases. */
9635 inits);
9636 }
9637 }
9639 /* Called from accumulate_vtbl_inits. Adds the initializers for the
9640 BINFO vtable to L. */
9642 static void
9644 tree orig_binfo,
9645 tree rtti_binfo,
9646 tree orig_vtbl,
9647 tree t,
9649 {
9656 {
9657 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
9658 primary virtual base. If it is not the same primary in
9659 the hierarchy of T, we'll need to generate a ctor vtable
9660 for it, to place at its location in T. If it is the same
9661 primary, we still need a VTT entry for the vtable, but it
9662 should point to the ctor vtable for the base it is a
9663 primary for within the sub-hierarchy of RTTI_BINFO.
9665 There are three possible cases:
9667 1) We are in the same place.
9668 2) We are a primary base within a lost primary virtual base of
9669 RTTI_BINFO.
9670 3) We are primary to something not a base of RTTI_BINFO. */
9672 tree b;
9675 /* First, look through the bases we are primary to for RTTI_BINFO
9676 or a virtual base. */
9679 {
9684 }
9685 /* If we run out of primary links, keep looking down our
9686 inheritance chain; we might be an indirect primary. */
9690 found:
9692 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
9693 base B and it is a base of RTTI_BINFO, this is case 2. In
9694 either case, we share our vtable with LAST, i.e. the
9695 derived-most base within B of which we are a primary. */
9698 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
9699 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
9700 binfo_ctor_vtable after everything's been set up. */
9703 /* Otherwise, this is case 3 and we get our own. */
9704 }
9711 {
9712 tree index;
9715 /* Add the initializer for this vtable. */
9719 /* Figure out the position to which the VPTR should point. */
9725 }
9728 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
9729 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
9730 straighten this out. */
9733 /* Throw away any unneeded intializers. */
9735 else
9736 /* For an ordinary vtable, set BINFO_VTABLE. */
9738 }
9743 /* Construct the initializer for BINFO's virtual function table. BINFO
9744 is part of the hierarchy dominated by T. If we're building a
9745 construction vtable, the ORIG_BINFO is the binfo we should use to
9746 find the actual function pointers to put in the vtable - but they
9747 can be overridden on the path to most-derived in the graph that
9748 ORIG_BINFO belongs. Otherwise,
9749 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
9750 BINFO that should be indicated by the RTTI information in the
9751 vtable; it will be a base class of T, rather than T itself, if we
9752 are building a construction vtable.
9754 The value returned is a TREE_LIST suitable for wrapping in a
9755 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9756 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9757 number of non-function entries in the vtable.
9759 It might seem that this function should never be called with a
9760 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9761 base is always subsumed by a derived class vtable. However, when
9762 we are building construction vtables, we do build vtables for
9763 primary bases; we need these while the primary base is being
9764 constructed. */
9766 static void
9768 tree orig_binfo,
9769 tree t,
9770 tree rtti_binfo,
9773 {
9774 tree v;
9775 vtbl_init_data vid;
9777 tree vbinfo;
9781 /* Initialize VID. */
9789 /* The first vbase or vcall offset is at index -3 in the vtable. */
9792 /* Add entries to the vtable for RTTI. */
9795 /* Create an array for keeping track of the functions we've
9796 processed. When we see multiple functions with the same
9797 signature, we share the vcall offsets. */
9799 /* Add the vcall and vbase offset entries. */
9802 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9803 build_vbase_offset_vtbl_entries. */
9808 /* If the target requires padding between data entries, add that now. */
9810 {
9816 /* Move data entries into their new positions and add padding
9817 after the new positions. Iterate backwards so we don't
9818 overwrite entries that we would need to process later. */
9821 ix--)
9822 {
9830 {
9834 null_pointer_node);
9835 }
9836 }
9837 }
9842 /* The initializers for virtual functions were built up in reverse
9843 order. Straighten them out and add them to the running list in one
9844 step. */
9853 /* Go through all the ordinary virtual functions, building up
9854 initializers. */
9856 {
9857 tree delta;
9858 tree vcall_index;
9865 {
9869 {
9872 }
9874 }
9876 /* If the only definition of this function signature along our
9877 primary base chain is from a lost primary, this vtable slot will
9878 never be used, so just zero it out. This is important to avoid
9879 requiring extra thunks which cannot be generated with the function.
9881 We first check this in update_vtable_entry_for_fn, so we handle
9882 restored primary bases properly; we also need to do it here so we
9883 zero out unused slots in ctor vtables, rather than filling them
9884 with erroneous values (though harmless, apart from relocation
9885 costs). */
9890 {
9891 /* Pull the offset for `this', and the function to call, out of
9892 the list. */
9899 /* You can't call an abstract virtual function; it's abstract.
9900 So, we replace these functions with __pure_virtual. */
9902 {
9905 {
9907 abort_fndecl_addr
9911 }
9912 }
9913 /* Likewise for deleted virtuals. */
9915 {
9917 {
9921 dvirt_fn = push_library_fn
9925 }
9930 }
9931 else
9932 {
9934 {
9939 }
9940 /* Take the address of the function, considering it to be of an
9941 appropriate generic type. */
9945 /* Don't refer to a virtual destructor from a constructor
9946 vtable or a vtable for an abstract class, since destroying
9947 an object under construction is undefined behavior and we
9948 don't want it to be considered a candidate for speculative
9949 devirtualization. But do create the thunk for ABI
9950 compliance. */
9955 }
9956 }
9958 /* And add it to the chain of initializers. */
9960 {
9965 else
9967 {
9973 }
9974 }
9975 else
9977 }
9978 }
9980 /* Adds to vid->inits the initializers for the vbase and vcall
9981 offsets in BINFO, which is in the hierarchy dominated by T. */
9983 static void
9985 {
9986 tree b;
9988 /* If this is a derived class, we must first create entries
9989 corresponding to the primary base class. */
9994 /* Add the vbase entries for this base. */
9996 /* Add the vcall entries for this base. */
9998 }
10000 /* Returns the initializers for the vbase offset entries in the vtable
10001 for BINFO (which is part of the class hierarchy dominated by T), in
10002 reverse order. VBASE_OFFSET_INDEX gives the vtable index
10003 where the next vbase offset will go. */
10005 static void
10007 {
10008 tree vbase;
10009 tree t;
10010 tree non_primary_binfo;
10012 /* If there are no virtual baseclasses, then there is nothing to
10013 do. */
10019 /* We might be a primary base class. Go up the inheritance hierarchy
10020 until we find the most derived class of which we are a primary base:
10021 it is the offset of that which we need to use. */
10024 {
10025 tree b;
10027 /* If we have reached a virtual base, then it must be a primary
10028 base (possibly multi-level) of vid->binfo, or we wouldn't
10029 have called build_vcall_and_vbase_vtbl_entries for it. But it
10030 might be a lost primary, so just skip down to vid->binfo. */
10032 {
10035 }
10041 }
10043 /* Go through the virtual bases, adding the offsets. */
10045 vbase;
10047 {
10048 tree b;
10049 tree delta;
10054 /* Find the instance of this virtual base in the complete
10055 object. */
10058 /* If we've already got an offset for this virtual base, we
10059 don't need another one. */
10064 /* Figure out where we can find this vbase offset. */
10073 /* The vbase offset had better be the same. */
10076 /* The next vbase will come at a more negative offset. */
10080 /* The initializer is the delta from BINFO to this virtual base.
10081 The vbase offsets go in reverse inheritance-graph order, and
10082 we are walking in inheritance graph order so these end up in
10083 the right order. */
10090 }
10091 }
10093 /* Adds the initializers for the vcall offset entries in the vtable
10094 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
10095 to VID->INITS. */
10097 static void
10099 {
10100 /* We only need these entries if this base is a virtual base. We
10101 compute the indices -- but do not add to the vtable -- when
10102 building the main vtable for a class. */
10105 /* If BINFO is RTTI_BINFO, then (since BINFO does not
10106 correspond to VID->DERIVED), we are building a primary
10107 construction virtual table. Since this is a primary
10108 virtual table, we do not need the vcall offsets for
10109 BINFO. */
10111 {
10112 /* We need a vcall offset for each of the virtual functions in this
10113 vtable. For example:
10115 class A { virtual void f (); };
10116 class B1 : virtual public A { virtual void f (); };
10117 class B2 : virtual public A { virtual void f (); };
10118 class C: public B1, public B2 { virtual void f (); };
10120 A C object has a primary base of B1, which has a primary base of A. A
10121 C also has a secondary base of B2, which no longer has a primary base
10122 of A. So the B2-in-C construction vtable needs a secondary vtable for
10123 A, which will adjust the A* to a B2* to call f. We have no way of
10124 knowing what (or even whether) this offset will be when we define B2,
10125 so we store this "vcall offset" in the A sub-vtable and look it up in
10126 a "virtual thunk" for B2::f.
10128 We need entries for all the functions in our primary vtable and
10129 in our non-virtual bases' secondary vtables. */
10131 /* If we are just computing the vcall indices -- but do not need
10132 the actual entries -- not that. */
10135 /* Now, walk through the non-virtual bases, adding vcall offsets. */
10137 }
10138 }
10140 /* Build vcall offsets, starting with those for BINFO. */
10142 static void
10144 {
10146 tree primary_binfo;
10147 tree base_binfo;
10149 /* Don't walk into virtual bases -- except, of course, for the
10150 virtual base for which we are building vcall offsets. Any
10151 primary virtual base will have already had its offsets generated
10152 through the recursion in build_vcall_and_vbase_vtbl_entries. */
10156 /* If BINFO has a primary base, process it first. */
10161 /* Add BINFO itself to the list. */
10164 /* Scan the non-primary bases of BINFO. */
10168 }
10170 /* Called from build_vcall_offset_vtbl_entries_r. */
10172 static void
10174 {
10175 /* Make entries for the rest of the virtuals. */
10176 tree orig_fn;
10178 /* The ABI requires that the methods be processed in declaration
10179 order. */
10181 orig_fn;
10185 }
10187 /* Add a vcall offset entry for ORIG_FN to the vtable. */
10189 static void
10191 {
10193 tree vcall_offset;
10194 tree derived_entry;
10196 /* If there is already an entry for a function with the same
10197 signature as FN, then we do not need a second vcall offset.
10198 Check the list of functions already present in the derived
10199 class vtable. */
10201 {
10203 /* We only use one vcall offset for virtual destructors,
10204 even though there are two virtual table entries. */
10208 }
10210 /* If we are building these vcall offsets as part of building
10211 the vtable for the most derived class, remember the vcall
10212 offset. */
10214 {
10217 }
10219 /* The next vcall offset will be found at a more negative
10220 offset. */
10224 /* Keep track of this function. */
10228 {
10229 tree base;
10230 tree fn;
10232 /* Find the overriding function. */
10236 else
10237 {
10240 /* The vbase we're working on is a primary base of
10241 vid->binfo. But it might be a lost primary, so its
10242 BINFO_OFFSET might be wrong, so we just use the
10243 BINFO_OFFSET from vid->binfo. */
10249 vcall_offset);
10250 }
10251 /* Add the initializer to the vtable. */
10253 }
10254 }
10256 /* Return vtbl initializers for the RTTI entries corresponding to the
10257 BINFO's vtable. The RTTI entries should indicate the object given
10258 by VID->rtti_binfo. */
10260 static void
10262 {
10263 tree b;
10264 tree t;
10265 tree offset;
10266 tree decl;
10267 tree init;
10271 /* To find the complete object, we will first convert to our most
10272 primary base, and then add the offset in the vtbl to that value. */
10277 /* The second entry is the address of the typeinfo object. */
10280 else
10283 /* Convert the declaration to a type that can be stored in the
10284 vtable. */
10288 /* Add the offset-to-top entry. It comes earlier in the vtable than
10289 the typeinfo entry. Convert the offset to look like a
10290 function pointer, so that we can put it in the vtable. */
10293 }
10295 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
10296 accessibility. */
10298 bool
10300 {
10303 }
10305 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
10307 bool
10309 {
10313 }
10315 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
10316 class between them, if any. */
10318 tree
10320 {
10332 {
10335 }
10339 }