| blob | b123932599153b65a7965745479a859274f098cd |
1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2015 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 /* The number of nested classes being processed. If we are not in the
42 scope of any class, this is zero. */
46 /* In order to deal with nested classes, we keep a stack of classes.
47 The topmost entry is the innermost class, and is the entry at index
48 CURRENT_CLASS_DEPTH */
51 /* The name of the class. */
52 tree name;
54 /* The _TYPE node for the class. */
55 tree type;
57 /* The access specifier pending for new declarations in the scope of
58 this class. */
59 tree access;
61 /* If were defining TYPE, the names used in this class. */
62 splay_tree names_used;
64 /* Nonzero if this class is no longer open, because of a call to
65 push_to_top_level. */
69 struct vtbl_init_data
70 {
71 /* The base for which we're building initializers. */
72 tree binfo;
73 /* The type of the most-derived type. */
74 tree derived;
75 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
76 unless ctor_vtbl_p is true. */
77 tree rtti_binfo;
78 /* The negative-index vtable initializers built up so far. These
79 are in order from least negative index to most negative index. */
81 /* The binfo for the virtual base for which we're building
82 vcall offset initializers. */
83 tree vbase;
84 /* The functions in vbase for which we have already provided vcall
85 offsets. */
87 /* The vtable index of the next vcall or vbase offset. */
88 tree index;
89 /* Nonzero if we are building the initializer for the primary
90 vtable. */
92 /* Nonzero if we are building the initializer for a construction
93 vtable. */
95 /* True when adding vcall offset entries to the vtable. False when
96 merely computing the indices. */
98 };
100 /* The type of a function passed to walk_subobject_offsets. */
103 /* The stack itself. This is a dynamically resized array. The
104 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
108 /* The size of the largest empty class seen in this translation unit. */
111 /* An array of all local classes present in this translation unit, in
112 declaration order. */
195 tree *);
205 splay_tree_key k2);
213 /* Variables shared between class.c and call.c. */
223 /* Convert to or from a base subobject. EXPR is an expression of type
224 `A' or `A*', an expression of type `B' or `B*' is returned. To
225 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
226 the B base instance within A. To convert base A to derived B, CODE
227 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
228 In this latter case, A must not be a morally virtual base of B.
229 NONNULL is true if EXPR is known to be non-NULL (this is only
230 needed when EXPR is of pointer type). CV qualifiers are preserved
231 from EXPR. */
233 tree
235 tree expr,
236 tree binfo,
238 tsubst_flags_t complain)
239 {
242 tree probe;
243 tree offset;
244 tree target_type;
246 tree ptr_target_type;
257 {
263 }
271 {
272 /* This can happen when adjust_result_of_qualified_name_lookup can't
273 find a unique base binfo in a call to a member function. We
274 couldn't give the diagnostic then since we might have been calling
275 a static member function, so we do it now. */
277 {
281 }
283 }
290 /* Nothing to do. */
294 {
296 {
298 {
301 "pointer to derived class %qT because the base is "
303 else
307 }
308 else
309 {
315 else
319 }
320 }
322 }
325 {
327 /* This must happen before the call to save_expr. */
329 }
330 else
336 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
337 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
338 expression returned matches the input. */
339 target_type = cp_build_qualified_type
343 /* Do we need to look in the vtable for the real offset? */
346 /* Don't bother with the calculations inside sizeof; they'll ICE if the
347 source type is incomplete and the pointer value doesn't matter. In a
348 template (even in instantiate_non_dependent_expr), we don't have vtables
349 set up properly yet, and the value doesn't matter there either; we're
350 just interested in the result of overload resolution. */
353 {
356 }
358 /* If we're in an NSDMI, we don't have the full constructor context yet
359 that we need for converting to a virtual base, so just build a stub
360 CONVERT_EXPR and expand it later in bot_replace. */
363 {
367 }
369 /* Do we need to check for a null pointer? */
371 {
372 /* If we know the conversion will not actually change the value
373 of EXPR, then we can avoid testing the expression for NULL.
374 We have to avoid generating a COMPONENT_REF for a base class
375 field, because other parts of the compiler know that such
376 expressions are always non-NULL. */
380 }
382 /* Protect against multiple evaluation if necessary. */
386 /* Now that we've saved expr, build the real null test. */
388 {
392 }
394 /* If this is a simple base reference, express it as a COMPONENT_REF. */
396 /* We don't build base fields for empty bases, and they aren't very
397 interesting to the optimizers anyway. */
399 {
408 }
411 {
412 /* Going via virtual base V_BINFO. We need the static offset
413 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
414 V_BINFO. That offset is an entry in D_BINFO's vtable. */
415 tree v_offset;
418 {
419 /* In a base member initializer, we cannot rely on the
420 vtable being set up. We have to indirect via the
421 vtt_parm. */
422 tree t;
428 }
429 else
430 {
433 {
438 }
440 complain),
442 }
450 v_offset);
462 /* Negative fixed_type_p means this is a constructor or destructor;
463 virtual base layout is fixed in in-charge [cd]tors, but not in
464 base [cd]tors. */
468 v_offset,
471 else
473 }
481 {
486 }
487 else
490 indout:
492 {
496 }
498 out:
504 }
506 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
507 Perform a derived-to-base conversion by recursively building up a
508 sequence of COMPONENT_REFs to the appropriate base fields. */
510 static tree
512 {
515 tree field;
518 {
519 tree temp;
523 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
524 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
525 an lvalue in the front end; only _DECLs and _REFs are lvalues
526 in the back end. */
532 }
534 /* Recurse. */
539 /* Is this the base field created by build_base_field? */
543 /* If we're looking for a field in the most-derived class,
544 also check the field offset; we can have two base fields
545 of the same type if one is an indirect virtual base and one
546 is a direct non-virtual base. */
550 {
551 /* We don't use build_class_member_access_expr here, as that
552 has unnecessary checks, and more importantly results in
553 recursive calls to dfs_walk_once. */
561 /* Mark the expression const or volatile, as appropriate.
562 Even though we've dealt with the type above, we still have
563 to mark the expression itself. */
570 }
572 /* Didn't find the base field?!? */
574 }
576 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
577 type is a class type or a pointer to a class type. In the former
578 case, TYPE is also a class type; in the latter it is another
579 pointer type. If CHECK_ACCESS is true, an error message is emitted
580 if TYPE is inaccessible. If OBJECT has pointer type, the value is
581 assumed to be non-NULL. */
583 tree
585 tsubst_flags_t complain)
586 {
587 tree binfo;
588 tree object_type;
591 {
594 }
595 else
604 }
606 /* EXPR is an expression with unqualified class type. BASE is a base
607 binfo of that class type. Returns EXPR, converted to the BASE
608 type. This function assumes that EXPR is the most derived class;
609 therefore virtual bases can be found at their static offsets. */
611 tree
613 {
614 tree expr_type;
618 {
619 /* If this is a non-empty base, use a COMPONENT_REF. */
623 /* We use fold_build2 and fold_convert below to simplify the trees
624 provided to the optimizers. It is not safe to call these functions
625 when processing a template because they do not handle C++-specific
626 trees. */
634 }
637 }
639 \f
640 tree
642 {
646 /* Can happen in case of duplicate base types (c++/59082). */
650 /* First, convert to the requested type. */
655 /* Second, the requested type may not be the owner of its own vptr.
656 If not, convert to the base class that owns it. We cannot use
657 convert_to_base here, because VCONTEXT may appear more than once
658 in the inheritance hierarchy of TYPE, and thus direct conversion
659 between the types may be ambiguous. Following the path back up
660 one step at a time via primary bases avoids the problem. */
664 {
667 }
670 }
672 /* Given an object INSTANCE, return an expression which yields the
673 vtable element corresponding to INDEX. There are many special
674 cases for INSTANCE which we take care of here, mainly to avoid
675 creating extra tree nodes when we don't have to. */
677 static tree
679 {
680 tree aref;
683 /* Try to figure out what a reference refers to, and
684 access its virtual function table directly. */
692 {
697 }
706 }
708 tree
710 {
714 }
716 /* Given a stable object pointer INSTANCE_PTR, return an expression which
717 yields a function pointer corresponding to vtable element INDEX. */
719 tree
721 {
722 tree aref;
725 tf_warning_or_error),
726 idx);
728 /* When using function descriptors, the address of the
729 vtable entry is treated as a function pointer. */
734 /* Remember this as a method reference, for later devirtualization. */
738 }
740 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
741 for the given TYPE. */
743 static tree
745 {
747 }
749 /* DECL is an entity associated with TYPE, like a virtual table or an
750 implicitly generated constructor. Determine whether or not DECL
751 should have external or internal linkage at the object file
752 level. This routine does not deal with COMDAT linkage and other
753 similar complexities; it simply sets TREE_PUBLIC if it possible for
754 entities in other translation units to contain copies of DECL, in
755 the abstract. */
757 void
759 {
762 }
764 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
765 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
766 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
768 static tree
770 {
771 tree decl;
774 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
775 now to avoid confusion in mangle_decl. */
786 /* The vtable has not been defined -- yet. */
790 /* Mark the VAR_DECL node representing the vtable itself as a
791 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
792 is rather important that such things be ignored because any
793 effort to actually generate DWARF for them will run into
794 trouble when/if we encounter code like:
796 #pragma interface
797 struct S { virtual void member (); };
799 because the artificial declaration of the vtable itself (as
800 manufactured by the g++ front end) will say that the vtable is
801 a static member of `S' but only *after* the debug output for
802 the definition of `S' has already been output. This causes
803 grief because the DWARF entry for the definition of the vtable
804 will try to refer back to an earlier *declaration* of the
805 vtable as a static member of `S' and there won't be one. We
806 might be able to arrange to have the "vtable static member"
807 attached to the member list for `S' before the debug info for
808 `S' get written (which would solve the problem) but that would
809 require more intrusive changes to the g++ front end. */
813 }
815 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
816 or even complete. If this does not exist, create it. If COMPLETE is
817 nonzero, then complete the definition of it -- that will render it
818 impossible to actually build the vtable, but is useful to get at those
819 which are known to exist in the runtime. */
821 tree
823 {
824 tree decl;
833 {
836 }
839 }
841 /* Build the primary virtual function table for TYPE. If BINFO is
842 non-NULL, build the vtable starting with the initial approximation
843 that it is the same as the one which is the head of the association
844 list. Returns a nonzero value if a new vtable is actually
845 created. */
847 static int
849 {
850 tree decl;
851 tree virtuals;
856 {
858 /* We have already created a vtable for this base, so there's
859 no need to do it again. */
866 }
867 else
868 {
871 }
874 {
877 }
879 /* Initialize the association list for this type, based
880 on our first approximation. */
885 }
887 /* Give BINFO a new virtual function table which is initialized
888 with a skeleton-copy of its original initialization. The only
889 entry that changes is the `delta' entry, so we can really
890 share a lot of structure.
892 FOR_TYPE is the most derived type which caused this table to
893 be needed.
895 Returns nonzero if we haven't met BINFO before.
897 The order in which vtables are built (by calling this function) for
898 an object must remain the same, otherwise a binary incompatibility
899 can result. */
901 static int
903 {
905 /* We already created a vtable for this base. There's no need to
906 do it again. */
909 /* Remember that we've created a vtable for this BINFO, so that we
910 don't try to do so again. */
913 /* Make fresh virtual list, so we can smash it later. */
916 /* Secondary vtables are laid out as part of the same structure as
917 the primary vtable. */
920 }
922 /* Create a new vtable for BINFO which is the hierarchy dominated by
923 T. Return nonzero if we actually created a new vtable. */
925 static int
927 {
929 /* In this case, it is *type*'s vtable we are modifying. We start
930 with the approximation that its vtable is that of the
931 immediate base class. */
933 else
934 /* This is our very own copy of `basetype' to play with. Later,
935 we will fill in all the virtual functions that override the
936 virtual functions in these base classes which are not defined
937 by the current type. */
939 }
941 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
942 (which is in the hierarchy dominated by T) list FNDECL as its
943 BV_FN. DELTA is the required constant adjustment from the `this'
944 pointer where the vtable entry appears to the `this' required when
945 the function is actually called. */
947 static void
949 tree binfo,
950 tree fndecl,
951 tree delta,
953 {
954 tree v;
960 {
961 /* We need a new vtable for BINFO. */
963 {
964 /* If we really did make a new vtable, we also made a copy
965 of the BINFO_VIRTUALS list. Now, we have to find the
966 corresponding entry in that list. */
971 }
976 }
977 }
979 \f
980 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
981 the USING_DECL naming METHOD. Returns true if the method could be
982 added to the method vec. */
984 bool
986 {
988 tree overload;
994 tree current_fns;
995 tree fns;
1008 {
1009 /* Make a new method vector. We start with 8 entries. We must
1010 allocate at least two (for constructors and destructors), and
1011 we're going to end up with an assignment operator at some
1012 point as well. */
1014 /* Create slots for constructors and destructors. */
1018 }
1020 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
1023 /* Constructors and destructors go in special slots. */
1027 {
1031 {
1037 type);
1038 }
1039 }
1040 else
1041 {
1042 tree m;
1045 /* See if we already have an entry with this name. */
1049 {
1052 {
1057 }
1061 {
1064 }
1069 }
1070 }
1073 /* Check to see if we've already got this method. */
1075 {
1077 tree fn_type;
1078 tree method_type;
1079 tree parms1;
1080 tree parms2;
1085 /* [over.load] Member function declarations with the
1086 same name and the same parameter types cannot be
1087 overloaded if any of them is a static member
1088 function declaration.
1090 [over.load] Member function declarations with the same name and
1091 the same parameter-type-list as well as member function template
1092 declarations with the same name, the same parameter-type-list, and
1093 the same template parameter lists cannot be overloaded if any of
1094 them, but not all, have a ref-qualifier.
1096 [namespace.udecl] When a using-declaration brings names
1097 from a base class into a derived class scope, member
1098 functions in the derived class override and/or hide member
1099 functions with the same name and parameter types in a base
1100 class (rather than conflicting). */
1106 /* Compare the quals on the 'this' parm. Don't compare
1107 the whole types, as used functions are treated as
1108 coming from the using class in overload resolution. */
1111 /* Either both or neither need to be ref-qualified for
1112 differing quals to allow overloading. */
1119 /* For templates, the return type and template parameters
1120 must be identical. */
1138 {
1139 /* For function versions, their parms and types match
1140 but they are not duplicates. Record function versions
1141 as and when they are found. extern "C" functions are
1142 not treated as versions. */
1148 {
1149 /* Mark functions as versions if necessary. Modify the mangled
1150 decl name if necessary. */
1152 {
1156 }
1158 {
1162 }
1165 }
1167 {
1169 {
1176 }
1177 /* Otherwise defer to the other function. */
1179 }
1181 {
1183 /* Defer to the local function. */
1185 }
1186 else
1187 {
1190 }
1192 /* We don't call duplicate_decls here to merge the
1193 declarations because that will confuse things if the
1194 methods have inline definitions. In particular, we
1195 will crash while processing the definitions. */
1197 }
1198 }
1200 /* A class should never have more than one destructor. */
1204 /* Add the new binding. */
1206 {
1209 }
1210 else
1219 {
1222 /* We only expect to add few methods in the COMPLETE_P case, so
1223 just make room for one more method in that case. */
1226 else
1232 else
1234 }
1235 else
1236 /* Replace the current slot. */
1239 }
1241 /* Subroutines of finish_struct. */
1243 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1244 legit, otherwise return 0. */
1246 static int
1248 {
1249 tree elem;
1258 {
1260 {
1264 else
1267 }
1268 else
1269 {
1270 /* They're changing the access to the same thing they changed
1271 it to before. That's OK. */
1272 ;
1273 }
1274 }
1275 else
1276 {
1278 tf_warning_or_error);
1281 }
1283 }
1285 /* Process the USING_DECL, which is a member of T. */
1287 static void
1289 {
1292 tree access
1297 tree old_value;
1302 tf_warning_or_error);
1304 {
1310 else
1312 }
1320 ;
1322 {
1324 /* It's OK to use functions from a base when there are functions with
1326 else
1327 {
1332 }
1333 }
1335 {
1339 }
1341 /* Make type T see field decl FDECL with access ACCESS. */
1344 {
1347 }
1348 else
1350 }
1351 \f
1352 /* Data structure for find_abi_tags_r, below. */
1354 struct abi_tag_data
1355 {
1359 };
1361 /* Subroutine of find_abi_tags_r. Handle a single TAG found on the class TP
1362 in the context of P. TAG can be either an identifier (the DECL_NAME of
1363 a tag NAMESPACE_DECL) or a STRING_CST (a tag attribute). */
1365 static void
1367 {
1369 {
1371 {
1372 /* We're collecting tags from template arguments or from
1373 the type of a variable or function return type. */
1376 /* Don't inherit this tag multiple times. */
1380 {
1381 /* Tags inherited from type template arguments are only used
1382 to avoid warnings. */
1385 }
1386 /* For functions and variables we want to warn, too. */
1387 }
1389 /* Otherwise we're diagnosing missing tags. */
1391 {
1396 }
1398 {
1402 }
1404 {
1409 }
1410 else
1411 {
1415 {
1419 }
1420 }
1421 }
1422 }
1424 /* Find all the ABI tags in the attribute list ATTR and either call
1425 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1427 static void
1429 {
1436 {
1441 else
1443 }
1444 }
1446 /* Find all the ABI tags on T and its enclosing scopes and either call
1447 check_tag (if TP is non-null) or set IDENTIFIER_MARKED to val. */
1449 static void
1451 {
1453 {
1454 tree attr;
1456 {
1459 }
1460 else
1461 {
1464 }
1466 }
1467 }
1469 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1470 types with ABI tags, add the corresponding identifiers to the VEC in
1471 *DATA and set IDENTIFIER_MARKED. */
1473 static tree
1475 {
1479 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1480 anyway, but let's make sure of it. */
1488 }
1490 /* walk_tree callback for mark_abi_tags: if *TP is a class, set
1491 IDENTIFIER_MARKED on its ABI tags. */
1493 static tree
1495 {
1499 /* walk_tree shouldn't be walking into any subtrees of a RECORD_TYPE
1500 anyway, but let's make sure of it. */
1508 }
1510 /* Set IDENTIFIER_MARKED on all the ABI tags on T and its enclosing
1511 scopes. */
1513 static void
1515 {
1518 {
1521 {
1522 /* Template arguments are part of the signature. */
1525 {
1528 }
1529 }
1531 /* A function's parameter types are part of the signature, so
1532 we don't need to inherit any tags that are also in them. */
1537 }
1538 }
1540 /* Check that T has all the ABI tags that subobject SUBOB has, or
1541 warn if not. If T is a (variable or function) declaration, also
1542 add any missing tags. */
1544 static void
1546 {
1554 /* No need to worry about things local to this TU. */
1567 {
1571 else
1575 }
1578 }
1580 /* Check that DECL has all the ABI tags that are used in parts of its type
1581 that are not reflected in its mangled name. */
1583 void
1585 {
1591 }
1593 void
1595 {
1605 {
1608 {
1612 }
1613 }
1615 // If we found some tags on our template arguments, add them to our
1616 // abi_tag attribute.
1618 {
1622 else
1626 }
1629 }
1631 /* Return true, iff class T has a non-virtual destructor that is
1632 accessible from outside the class heirarchy (i.e. is public, or
1633 there's a suitable friend. */
1635 static bool
1637 {
1640 /* An implicitly declared destructor is always public. And,
1641 if it were virtual, we would have created it by now. */
1656 }
1658 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1659 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1660 properties of the bases. */
1662 static void
1666 {
1670 tree base_binfo;
1671 tree binfo;
1681 {
1690 /* If any base class is non-literal, so is the derived class. */
1694 /* If the base class doesn't have copy constructors or
1695 assignment operators that take const references, then the
1696 derived class cannot have such a member automatically
1697 generated. */
1706 /* A virtual base does not effect nearly emptiness. */
1707 ;
1709 {
1711 /* And if there is more than one nearly empty base, then the
1712 derived class is not nearly empty either. */
1714 else
1715 /* Remember we've seen one. */
1717 }
1719 /* If the base class is not empty or nearly empty, then this
1720 class cannot be nearly empty. */
1723 /* A lot of properties from the bases also apply to the derived
1724 class. */
1741 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT
1744 SET_CLASSTYPE_REF_FIELDS_NEED_INIT
1748 /* A standard-layout class is a class that:
1749 ...
1750 * has no non-standard-layout base classes, */
1753 {
1754 tree basefield;
1755 /* ...has no base classes of the same type as the first non-static
1756 data member... */
1758 && (same_type_ignoring_top_level_qualifiers_p
1761 else
1762 /* ...either has no non-static data members in the most-derived
1763 class and at most one base class with non-static data
1764 members, or has no base classes with non-static data
1765 members */
1769 {
1772 else
1775 }
1776 }
1778 /* Don't bother collecting tm attributes if transactional memory
1779 support is not enabled. */
1781 {
1785 }
1788 }
1790 /* If one of the base classes had TM attributes, and the current class
1791 doesn't define its own, then the current class inherits one. */
1793 {
1796 }
1797 }
1799 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1800 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1801 that have had a nearly-empty virtual primary base stolen by some
1802 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1803 T. */
1805 static void
1807 {
1811 tree base_binfo;
1813 /* Determine the primary bases of our bases. */
1816 {
1819 /* See if we're the non-virtual primary of our inheritance
1820 chain. */
1822 {
1829 /* We are the primary binfo. */
1831 }
1832 /* Determine if we have a virtual primary base, and mark it so.
1833 */
1835 {
1839 /* Someone already claimed this base. */
1841 else
1842 {
1843 tree delta;
1848 /* A virtual binfo might have been copied from within
1849 another hierarchy. As we're about to use it as a
1850 primary base, make sure the offsets match. */
1858 }
1859 }
1860 }
1862 /* First look for a dynamic direct non-virtual base. */
1864 {
1868 {
1871 }
1872 }
1874 /* A "nearly-empty" virtual base class can be the primary base
1875 class, if no non-virtual polymorphic base can be found. Look for
1876 a nearly-empty virtual dynamic base that is not already a primary
1877 base of something in the hierarchy. If there is no such base,
1878 just pick the first nearly-empty virtual base. */
1884 {
1886 {
1887 /* Found one that is not primary. */
1890 }
1892 /* Remember the first candidate. */
1894 }
1896 found:
1897 /* If we've got a primary base, use it. */
1899 {
1904 /* We are stealing a primary base. */
1908 {
1909 tree delta;
1912 /* A virtual binfo might have been copied from within
1913 another hierarchy. As we're about to use it as a primary
1914 base, make sure the offsets match. */
1919 }
1926 }
1927 }
1929 /* Update the variant types of T. */
1931 void
1933 {
1934 tree variants;
1940 variants;
1942 {
1943 /* These fields are in the _TYPE part of the node, not in
1944 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1954 /* Copy whatever these are holding today. */
1957 }
1958 }
1960 /* Early variant fixups: we apply attributes at the beginning of the class
1961 definition, and we need to fix up any variants that have already been
1962 made via elaborated-type-specifier so that check_qualified_type works. */
1964 void
1966 {
1967 tree variants;
1977 variants;
1979 {
1980 /* These are the two fields that check_qualified_type looks at and
1981 are affected by attributes. */
1986 else
1989 }
1990 }
1991 \f
1992 /* Set memoizing fields and bits of T (and its variants) for later
1993 use. */
1995 static void
1997 {
1998 /* Fix up variants (if any). */
2002 /* For a class w/o baseclasses, 'finish_struct' has set
2003 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
2004 Similarly for a class whose base classes do not have vtables.
2005 When neither of these is true, we might have removed abstract
2006 virtuals (by providing a definition), added some (by declaring
2007 new ones), or redeclared ones from a base class. We need to
2008 recalculate what's really an abstract virtual at this point (by
2009 looking in the vtables). */
2012 /* If this type has a copy constructor or a destructor, force its
2013 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
2014 nonzero. This will cause it to be passed by invisible reference
2015 and prevent it from being returned in a register. */
2018 {
2019 tree variants;
2022 {
2025 }
2026 }
2027 }
2029 /* Issue warnings about T having private constructors, but no friends,
2030 and so forth.
2032 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
2033 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
2034 non-private static member functions. */
2036 static void
2038 {
2041 tree fn;
2044 /* If the class has friends, those entities might create and
2045 access instances, so we should not warn. */
2048 /* We will have warned when the template was declared; there's
2049 no need to warn on every instantiation. */
2051 /* There's no reason to even consider warning about this
2052 class. */
2055 /* We only issue one warning, if more than one applies, because
2056 otherwise, on code like:
2058 class A {
2059 // Oops - forgot `public:'
2060 A();
2061 A(const A&);
2062 ~A();
2063 };
2065 we warn several times about essentially the same problem. */
2067 /* Check to see if all (non-constructor, non-destructor) member
2068 functions are private. (Since there are no friends or
2069 non-private statics, we can't ever call any of the private member
2070 functions.) */
2072 /* We're not interested in compiler-generated methods; they don't
2073 provide any way to call private members. */
2075 {
2077 {
2079 /* A non-private static member function is just like a
2080 friend; it can create and invoke private member
2081 functions, and be accessed without a class
2082 instance. */
2086 /* Keep searching for a static member function. */
2087 }
2090 }
2093 {
2094 /* There are no non-private methods, and there's at least one
2095 private member function that isn't a constructor or
2096 destructor. (If all the private members are
2097 constructors/destructors we want to use the code below that
2098 issues error messages specifically referring to
2099 constructors/destructors.) */
2105 {
2108 }
2110 {
2114 }
2115 }
2117 /* Even if some of the member functions are non-private, the class
2118 won't be useful for much if all the constructors or destructors
2119 are private: such an object can never be created or destroyed. */
2122 {
2125 t);
2127 }
2129 /* Warn about classes that have private constructors and no friends. */
2131 /* Implicitly generated constructors are always public. */
2134 {
2137 /* If a non-template class does not define a copy
2138 constructor, one is defined for it, enabling it to avoid
2139 this warning. For a template class, this does not
2140 happen, and so we would normally get a warning on:
2142 template <class T> class C { private: C(); };
2144 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
2145 complete non-template or fully instantiated classes have this
2146 flag set. */
2149 else
2151 {
2153 /* Ideally, we wouldn't count copy constructors (or, in
2154 fact, any constructor that takes an argument of the
2155 class type as a parameter) because such things cannot
2156 be used to construct an instance of the class unless
2157 you already have one. But, for now at least, we're
2158 more generous. */
2160 {
2163 }
2164 }
2167 {
2170 t);
2172 }
2173 }
2174 }
2177 gt_pointer_operator new_value;
2181 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
2183 static int
2185 {
2198 }
2200 /* This routine compares two fields like method_name_cmp but using the
2201 pointer operator in resort_field_decl_data. */
2203 static int
2205 {
2214 {
2221 }
2223 }
2225 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
2227 void
2230 gt_pointer_operator new_value,
2232 {
2236 tree fn;
2238 /* The type conversion ops have to live at the front of the vec, so we
2239 can't sort them. */
2247 {
2251 resort_method_name_cmp);
2252 }
2253 }
2255 /* Warn about duplicate methods in fn_fields.
2257 Sort methods that are not special (i.e., constructors, destructors,
2258 and type conversion operators) so that we can find them faster in
2259 search. */
2261 static void
2263 {
2264 tree fn_fields;
2274 /* Clear DECL_IN_AGGR_P for all functions. */
2279 /* Issue warnings about private constructors and such. If there are
2280 no methods, then some public defaults are generated. */
2283 /* The type conversion ops have to live at the front of the vec, so we
2284 can't sort them. */
2293 }
2295 /* Make BINFO's vtable have N entries, including RTTI entries,
2296 vbase and vcall offsets, etc. Set its type and call the back end
2297 to lay it out. */
2299 static void
2301 {
2302 tree atype;
2303 tree vtable;
2308 /* We may have to grow the vtable. */
2311 {
2315 }
2316 }
2318 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2319 have the same signature. */
2321 int
2323 {
2324 /* One destructor overrides another if they are the same kind of
2325 destructor. */
2329 /* But a non-destructor never overrides a destructor, nor vice
2330 versa, nor do different kinds of destructors override
2331 one-another. For example, a complete object destructor does not
2332 override a deleting destructor. */
2341 {
2349 }
2351 }
2353 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2354 subobject. */
2356 static bool
2358 {
2359 tree probe;
2362 {
2366 /* If we meet a virtual base, we can't follow the inheritance
2367 any more. See if the complete type of DERIVED contains
2368 such a virtual base. */
2371 }
2373 }
2376 /* The function for which we are trying to find a final overrider. */
2377 tree fn;
2378 /* The base class in which the function was declared. */
2379 tree declaring_base;
2380 /* The candidate overriders. */
2381 tree candidates;
2382 /* Path to most derived. */
2384 };
2386 /* Add the overrider along the current path to FFOD->CANDIDATES.
2387 Returns true if an overrider was found; false otherwise. */
2389 static bool
2393 {
2394 tree method;
2396 /* If BINFO is not the most derived type, try a more derived class.
2397 A definition there will overrider a definition here. */
2399 {
2400 depth--;
2404 }
2408 {
2411 /* Remove any candidates overridden by this new function. */
2413 {
2414 /* If *CANDIDATE overrides METHOD, then METHOD
2415 cannot override anything else on the list. */
2418 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2421 else
2423 }
2425 /* Add the new function. */
2428 }
2431 }
2433 /* Called from find_final_overrider via dfs_walk. */
2435 static tree
2437 {
2445 }
2447 static tree
2449 {
2454 }
2456 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2457 FN and whose TREE_VALUE is the binfo for the base where the
2458 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2459 DERIVED) is the base object in which FN is declared. */
2461 static tree
2463 {
2464 find_final_overrider_data ffod;
2466 /* Getting this right is a little tricky. This is valid:
2468 struct S { virtual void f (); };
2469 struct T { virtual void f (); };
2470 struct U : public S, public T { };
2472 even though calling `f' in `U' is ambiguous. But,
2474 struct R { virtual void f(); };
2475 struct S : virtual public R { virtual void f (); };
2476 struct T : virtual public R { virtual void f (); };
2477 struct U : public S, public T { };
2479 is not -- there's no way to decide whether to put `S::f' or
2480 `T::f' in the vtable for `R'.
2482 The solution is to look at all paths to BINFO. If we find
2483 different overriders along any two, then there is a problem. */
2487 /* Determine the depth of the hierarchy. */
2498 /* If there was no winner, issue an error message. */
2503 }
2505 /* Return the index of the vcall offset for FN when TYPE is used as a
2506 virtual base. */
2508 static tree
2510 {
2512 tree_pair_p p;
2520 /* There should always be an appropriate index. */
2522 }
2524 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2525 dominated by T. FN is the old function; VIRTUALS points to the
2526 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2527 of that entry in the list. */
2529 static void
2532 {
2533 tree b;
2534 tree overrider;
2535 tree delta;
2536 tree virtual_base;
2537 tree first_defn;
2543 /* Find the nearest primary base (possibly binfo itself) which defines
2544 this function; this is the class the caller will convert to when
2545 calling FN through BINFO. */
2547 {
2552 /* The nearest definition is from a lost primary. */
2555 }
2558 /* Find the final overrider. */
2561 {
2564 }
2567 /* Check for adjusting covariant return types. */
2575 /* If the overrider is invalid, don't even try. */
2577 {
2578 /* If FN is a covariant thunk, we must figure out the adjustment
2579 to the final base FN was converting to. As OVERRIDER_TARGET might
2580 also be converting to the return type of FN, we have to
2581 combine the two conversions here. */
2588 {
2592 }
2593 else
2597 /* Find the equivalent binfo within the return type of the
2598 overriding function. We will want the vbase offset from
2599 there. */
2601 over_return);
2604 {
2605 /* There was no existing virtual thunk (which takes
2606 precedence). So find the binfo of the base function's
2607 return type within the overriding function's return type.
2608 We cannot call lookup base here, because we're inside a
2609 dfs_walk, and will therefore clobber the BINFO_MARKED
2610 flags. Fortunately we know the covariancy is valid (it
2611 has already been checked), so we can just iterate along
2612 the binfos, which have been chained in inheritance graph
2613 order. Of course it is lame that we have to repeat the
2614 search here anyway -- we should really be caching pieces
2615 of the vtable and avoiding this repeated work. */
2618 /* Find the base binfo within the overriding function's
2619 return type. We will always find a thunk_binfo, except
2620 when the covariancy is invalid (which we will have
2621 already diagnosed). */
2624 thunk_binfo;
2630 /* See if virtual inheritance is involved. */
2632 virtual_offset;
2639 {
2643 {
2644 /* We convert via virtual base. Adjust the fixed
2645 offset to be from there. */
2646 offset =
2650 }
2652 /* There was an existing fixed offset, this must be
2653 from the base just converted to, and the base the
2654 FN was thunking to. */
2656 else
2658 }
2659 }
2662 /* Replace the overriding function with a covariant thunk. We
2663 will emit the overriding function in its own slot as
2664 well. */
2667 }
2668 else
2672 /* If we need a covariant thunk, then we may need to adjust first_defn.
2673 The ABI specifies that the thunks emitted with a function are
2674 determined by which bases the function overrides, so we need to be
2675 sure that we're using a thunk for some overridden base; even if we
2676 know that the necessary this adjustment is zero, there may not be an
2677 appropriate zero-this-adjusment thunk for us to use since thunks for
2678 overriding virtual bases always use the vcall offset.
2680 Furthermore, just choosing any base that overrides this function isn't
2681 quite right, as this slot won't be used for calls through a type that
2682 puts a covariant thunk here. Calling the function through such a type
2683 will use a different slot, and that slot is the one that determines
2684 the thunk emitted for that base.
2686 So, keep looking until we find the base that we're really overriding
2687 in this slot: the nearest primary base that doesn't use a covariant
2688 thunk in this slot. */
2690 {
2692 /* We already know that the overrider needs a covariant thunk. */
2695 {
2702 }
2704 }
2706 /* Assume that we will produce a thunk that convert all the way to
2707 the final overrider, and not to an intermediate virtual base. */
2710 /* See if we can convert to an intermediate virtual base first, and then
2711 use the vcall offset located there to finish the conversion. */
2713 {
2714 /* If we find the final overrider, then we can stop
2715 walking. */
2720 /* If we find a virtual base, and we haven't yet found the
2721 overrider, then there is a virtual base between the
2722 declaring base (first_defn) and the final overrider. */
2724 {
2727 }
2728 }
2730 /* Compute the constant adjustment to the `this' pointer. The
2731 `this' pointer, when this function is called, will point at BINFO
2732 (or one of its primary bases, which are at the same offset). */
2734 /* The `this' pointer needs to be adjusted from the declaration to
2735 the nearest virtual base. */
2740 /* If the nearest definition is in a lost primary, we don't need an
2741 entry in our vtable. Except possibly in a constructor vtable,
2742 if we happen to get our primary back. In that case, the offset
2743 will be zero, as it will be a primary base. */
2745 else
2746 /* The `this' pointer needs to be adjusted from pointing to
2747 BINFO to pointing at the base where the final overrider
2748 appears. */
2759 else
2763 }
2765 /* Called from modify_all_vtables via dfs_walk. */
2767 static tree
2769 {
2771 tree virtuals;
2772 tree old_virtuals;
2776 /* A base without a vtable needs no modification, and its bases
2777 are uninteresting. */
2782 /* Don't do the primary vtable, if it's new. */
2786 /* There's no need to modify the vtable for a non-virtual primary
2787 base; we're not going to use that vtable anyhow. We do still
2788 need to do this for virtual primary bases, as they could become
2789 non-primary in a construction vtable. */
2794 /* Now, go through each of the virtual functions in the virtual
2795 function table for BINFO. Find the final overrider, and update
2796 the BINFO_VIRTUALS list appropriately. */
2799 virtuals;
2803 binfo,
2808 }
2810 /* Update all of the primary and secondary vtables for T. Create new
2811 vtables as required, and initialize their RTTI information. Each
2812 of the functions in VIRTUALS is declared in T and may override a
2813 virtual function from a base class; find and modify the appropriate
2814 entries to point to the overriding functions. Returns a list, in
2815 declaration order, of the virtual functions that are declared in T,
2816 but do not appear in the primary base class vtable, and which
2817 should therefore be appended to the end of the vtable for T. */
2819 static tree
2821 {
2825 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2829 /* Update all of the vtables. */
2832 /* Add virtual functions not already in our primary vtable. These
2833 will be both those introduced by this class, and those overridden
2834 from secondary bases. It does not include virtuals merely
2835 inherited from secondary bases. */
2837 {
2842 {
2843 /* We don't need to adjust the `this' pointer when
2844 calling this function. */
2848 /* This is a function not already in our vtable. Keep it. */
2850 }
2851 else
2852 /* We've already got an entry for this function. Skip it. */
2854 }
2857 }
2859 /* Get the base virtual function declarations in T that have the
2860 indicated NAME. */
2862 static void
2864 {
2865 tree methods;
2869 /* Find virtual functions in T with the indicated NAME. */
2874 methods;
2876 {
2881 {
2884 }
2885 }
2891 {
2894 }
2895 }
2897 /* If this declaration supersedes the declaration of
2898 a method declared virtual in the base class, then
2899 mark this field as being virtual as well. */
2901 void
2903 {
2906 /* In [temp.mem] we have:
2908 A specialization of a member function template does not
2909 override a virtual function from a base class. */
2916 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2917 the error_mark_node so that we know it is an overriding
2918 function. */
2919 {
2926 }
2929 {
2935 }
2940 }
2942 /* Warn about hidden virtual functions that are not overridden in t.
2943 We know that constructors and destructors don't apply. */
2945 static void
2947 {
2949 tree fns;
2952 /* We go through each separately named virtual function. */
2956 {
2957 tree fn;
2958 tree name;
2959 tree fndecl;
2960 tree base_binfo;
2961 tree binfo;
2964 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2965 have the same name. Figure out what name that is. */
2967 /* There are no possibly hidden functions yet. */
2969 /* Iterate through all of the base classes looking for possibly
2970 hidden functions. */
2973 {
2976 }
2978 /* If there are no functions to hide, continue. */
2982 /* Remove any overridden functions. */
2984 {
2988 {
2989 /* If the method from the base class has the same
2990 signature as the method from the derived class, it
2991 has been overridden. */
2996 }
2997 }
2999 /* Now give a warning for all base functions without overriders,
3000 as they are hidden. */
3002 tree base_fndecl;
3005 {
3006 /* Here we know it is a hider, and no overrider exists. */
3008 OPT_Woverloaded_virtual,
3012 }
3013 }
3014 }
3016 /* Recursive helper for finish_struct_anon. */
3018 static void
3020 {
3024 {
3025 /* We're generally only interested in entities the user
3026 declared, but we also find nested classes by noticing
3027 the TYPE_DECL that we create implicitly. You're
3028 allowed to put one anonymous union inside another,
3029 though, so we explicitly tolerate that. We use
3030 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
3031 we also allow unnamed types used for defining fields. */
3038 {
3039 /* We already complained about static data members in
3040 finish_static_data_member_decl. */
3042 {
3045 "%q#D invalid; an anonymous union can "
3047 else
3049 "%q#D invalid; an anonymous struct can "
3051 }
3053 }
3056 {
3058 {
3062 else
3065 }
3067 {
3071 else
3074 }
3075 }
3080 /* Recurse into the anonymous aggregates to handle correctly
3081 access control (c++/24926):
3083 class A {
3084 union {
3085 union {
3086 int i;
3087 };
3088 };
3089 };
3091 int j=A().i; */
3095 }
3096 }
3098 /* Check for things that are invalid. There are probably plenty of other
3099 things we should check for also. */
3101 static void
3103 {
3105 {
3114 }
3115 }
3117 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
3118 will be used later during class template instantiation.
3119 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
3120 a non-static member data (FIELD_DECL), a member function
3121 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
3122 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
3123 When FRIEND_P is nonzero, T is either a friend class
3124 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
3125 (FUNCTION_DECL, TEMPLATE_DECL). */
3127 void
3129 {
3130 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
3135 }
3137 /* This function is called from declare_virt_assop_and_dtor via
3138 dfs_walk_all.
3140 DATA is a type that direcly or indirectly inherits the base
3141 represented by BINFO. If BINFO contains a virtual assignment [copy
3142 assignment or move assigment] operator or a virtual constructor,
3143 declare that function in DATA if it hasn't been already declared. */
3145 static tree
3147 {
3155 /* A base without a vtable needs no modification, and its bases
3156 are uninteresting. */
3160 /* If this is a primary base, then we have already looked at the
3161 virtual functions of its vtable. */
3165 {
3169 {
3174 }
3178 }
3181 }
3183 /* If the class type T has a direct or indirect base that contains a
3184 virtual assignment operator or a virtual destructor, declare that
3185 function in T if it hasn't been already declared. */
3187 static void
3189 {
3197 dfs_declare_virt_assop_and_dtor,
3199 }
3201 /* Declare the inheriting constructor for class T inherited from base
3202 constructor CTOR with the parameter array PARMS of size NPARMS. */
3204 static void
3206 {
3207 /* We don't declare an inheriting ctor that would be a default,
3208 copy or move ctor for derived or base. */
3213 {
3217 }
3226 {
3229 }
3230 }
3232 /* Declare all the inheriting constructors for class T inherited from base
3233 constructor CTOR. */
3235 static void
3237 {
3243 {
3247 }
3250 {
3254 }
3255 }
3257 /* Create default constructors, assignment operators, and so forth for
3258 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
3259 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
3260 the class cannot have a default constructor, copy constructor
3261 taking a const reference argument, or an assignment operator taking
3262 a const reference, respectively. */
3264 static void
3268 {
3276 /* Destructor. */
3278 {
3279 /* In general, we create destructors lazily. */
3284 /* But if this is a Java class, any non-trivial destructor is
3285 invalid, even if compiler-generated. Therefore, if the
3286 destructor is non-trivial we create it now. */
3288 }
3290 /* [class.ctor]
3292 If there is no user-declared constructor for a class, a default
3293 constructor is implicitly declared. */
3295 {
3300 /* This might force the declaration. */
3302 }
3304 /* [class.ctor]
3306 If a class definition does not explicitly declare a copy
3307 constructor, one is declared implicitly. */
3309 {
3315 }
3317 /* If there is no assignment operator, one will be created if and
3318 when it is needed. For now, just record whether or not the type
3319 of the parameter to the assignment operator will be a const or
3320 non-const reference. */
3322 {
3328 }
3330 /* We can't be lazy about declaring functions that might override
3331 a virtual function from a base class. */
3335 {
3339 {
3340 /* declare, then remove the decl */
3349 }
3350 else
3352 }
3353 }
3355 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3356 count the number of fields in TYPE, including anonymous union
3357 members. */
3359 static int
3361 {
3362 tree x;
3365 {
3368 else
3370 }
3372 }
3374 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3375 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3376 elts, starting at offset IDX. */
3378 static int
3380 {
3381 tree x;
3383 {
3386 else
3388 }
3390 }
3392 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3393 starting at offset IDX. */
3395 static int
3399 {
3400 tree values;
3404 }
3406 /* FIELD is a bit-field. We are finishing the processing for its
3407 enclosing type. Issue any appropriate messages and set appropriate
3408 flags. Returns false if an error has been diagnosed. */
3410 static bool
3412 {
3414 tree w;
3416 /* Extract the declared width of the bitfield, which has been
3417 temporarily stashed in DECL_INITIAL. */
3420 /* Remove the bit-field width indicator so that the rest of the
3421 compiler does not treat that value as an initializer. */
3424 /* Detect invalid bit-field type. */
3426 {
3429 }
3430 else
3431 {
3433 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3436 /* detect invalid field size. */
3442 {
3445 }
3447 {
3450 }
3452 {
3455 }
3470 }
3473 {
3477 }
3478 else
3479 {
3480 /* Non-bit-fields are aligned for their type. */
3484 }
3485 }
3487 /* FIELD is a non bit-field. We are finishing the processing for its
3488 enclosing type T. Issue any appropriate messages and set appropriate
3489 flags. */
3491 static void
3493 tree t,
3497 {
3500 /* In C++98 an anonymous union cannot contain any fields which would change
3501 the settings of CANT_HAVE_CONST_CTOR and friends. */
3503 ;
3504 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3505 structs. So, we recurse through their fields here. */
3507 {
3508 tree fields;
3514 }
3515 /* Check members with class type for constructors, destructors,
3516 etc. */
3518 {
3519 /* Never let anything with uninheritable virtuals
3520 make it through without complaint. */
3524 {
3529 field);
3534 field);
3536 {
3540 }
3541 }
3542 else
3543 {
3556 }
3565 }
3570 {
3571 /* `build_class_init_list' does not recognize
3572 non-FIELD_DECLs. */
3576 }
3577 }
3579 /* Check the data members (both static and non-static), class-scoped
3580 typedefs, etc., appearing in the declaration of T. Issue
3581 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3582 declaration order) of access declarations; each TREE_VALUE in this
3583 list is a USING_DECL.
3585 In addition, set the following flags:
3587 EMPTY_P
3588 The class is empty, i.e., contains no non-static data members.
3590 CANT_HAVE_CONST_CTOR_P
3591 This class cannot have an implicitly generated copy constructor
3592 taking a const reference.
3594 CANT_HAVE_CONST_ASN_REF
3595 This class cannot have an implicitly generated assignment
3596 operator taking a const reference.
3598 All of these flags should be initialized before calling this
3599 function.
3601 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3602 fields can be added by adding to this chain. */
3604 static void
3608 {
3616 /* Assume there are no access declarations. */
3618 /* Assume this class has no pointer members. */
3620 /* Assume none of the members of this class have default
3621 initializations. */
3625 {
3633 {
3634 /* Save the access declarations for our caller. */
3637 }
3643 /* If we've gotten this far, it's a data member, possibly static,
3644 or an enumerator. */
3648 /* When this goes into scope, it will be a non-local reference. */
3653 {
3654 /* [class.union] (C++98)
3656 If a union contains a static data member, or a member of
3657 reference type, the program is ill-formed.
3659 In C++11 this limitation doesn't exist anymore. */
3661 {
3665 }
3667 {
3671 }
3672 }
3674 /* Perform error checking that did not get done in
3675 grokdeclarator. */
3677 {
3681 }
3683 {
3687 }
3695 /* Now it can only be a FIELD_DECL. */
3700 /* If at least one non-static data member is non-literal, the whole
3701 class becomes non-literal. Per Core/1453, volatile non-static
3702 data members and base classes are also not allowed.
3703 Note: if the type is incomplete we will complain later on. */
3708 /* A standard-layout class is a class that:
3709 ...
3710 has the same access control (Clause 11) for all non-static data members,
3711 ... */
3718 /* If this is of reference type, check if it needs an init. */
3720 {
3726 {
3727 /* ARM $12.6.2: [A member initializer list] (or, for an
3728 aggregate, initialization by a brace-enclosed list) is the
3729 only way to initialize nonstatic const and reference
3730 members. */
3733 }
3734 }
3739 {
3741 {
3742 warning_at
3745 x);
3747 }
3751 }
3754 /* We don't treat zero-width bitfields as making a class
3755 non-empty. */
3756 ;
3757 else
3758 {
3759 /* The class is non-empty. */
3761 /* The class is not even nearly empty. */
3763 /* If one of the data members contains an empty class,
3764 so does T. */
3768 }
3770 /* This is used by -Weffc++ (see below). Warn only for pointers
3771 to members which might hold dynamic memory. So do not warn
3772 for pointers to functions or pointers to members. */
3778 {
3783 }
3789 {
3791 {
3795 }
3797 {
3801 }
3802 }
3805 /* DR 148 now allows pointers to members (which are POD themselves),
3806 to be allowed in POD structs. */
3815 /* We set DECL_C_BIT_FIELD in grokbitfield.
3816 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3819 cant_have_const_ctor_p,
3820 no_const_asn_ref_p,
3823 /* Now that we've removed bit-field widths from DECL_INITIAL,
3824 anything left in DECL_INITIAL is an NSDMI that makes the class
3825 non-aggregate in C++11. */
3829 /* If any field is const, the structure type is pseudo-const. */
3831 {
3836 {
3837 /* ARM $12.6.2: [A member initializer list] (or, for an
3838 aggregate, initialization by a brace-enclosed list) is the
3839 only way to initialize nonstatic const and reference
3840 members. */
3843 }
3844 }
3845 /* A field that is pseudo-const makes the structure likewise. */
3847 {
3852 }
3854 /* Core issue 80: A nonstatic data member is required to have a
3855 different name from the class iff the class has a
3856 user-declared constructor. */
3861 }
3863 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3864 it should also define a copy constructor and an assignment operator to
3865 implement the correct copy semantic (deep vs shallow, etc.). As it is
3866 not feasible to check whether the constructors do allocate dynamic memory
3867 and store it within members, we approximate the warning like this:
3869 -- Warn only if there are members which are pointers
3870 -- Warn only if there is a non-trivial constructor (otherwise,
3871 there cannot be memory allocated).
3872 -- Warn only if there is a non-trivial destructor. We assume that the
3873 user at least implemented the cleanup correctly, and a destructor
3874 is needed to free dynamic memory.
3876 This seems enough for practical purposes. */
3878 && has_pointers
3882 {
3886 {
3891 }
3895 }
3897 /* Non-static data member initializers make the default constructor
3898 non-trivial. */
3900 {
3903 }
3905 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3909 /* Check anonymous struct/anonymous union fields. */
3912 /* We've built up the list of access declarations in reverse order.
3913 Fix that now. */
3915 }
3917 /* If TYPE is an empty class type, records its OFFSET in the table of
3918 OFFSETS. */
3920 static int
3922 {
3923 splay_tree_node n;
3928 /* Record the location of this empty object in OFFSETS. */
3936 type,
3940 }
3942 /* Returns nonzero if TYPE is an empty class type and there is
3943 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3945 static int
3947 {
3948 splay_tree_node n;
3949 tree t;
3954 /* Record the location of this empty object in OFFSETS. */
3964 }
3966 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3967 F for every subobject, passing it the type, offset, and table of
3968 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3969 be traversed.
3971 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3972 than MAX_OFFSET will not be walked.
3974 If F returns a nonzero value, the traversal ceases, and that value
3975 is returned. Otherwise, returns zero. */
3977 static int
3979 subobject_offset_fn f,
3980 tree offset,
3981 splay_tree offsets,
3982 tree max_offset,
3984 {
3988 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3989 stop. */
3997 {
4000 }
4003 {
4004 tree field;
4005 tree binfo;
4008 /* Avoid recursing into objects that are not interesting. */
4012 /* Record the location of TYPE. */
4017 /* Iterate through the direct base classes of TYPE. */
4021 {
4022 tree binfo_offset;
4027 tree orig_binfo;
4028 /* We cannot rely on BINFO_OFFSET being set for the base
4029 class yet, but the offsets for direct non-virtual
4030 bases can be calculated by going back to the TYPE. */
4033 offset,
4037 f,
4038 binfo_offset,
4039 offsets,
4040 max_offset,
4044 }
4047 {
4051 /* Iterate through the virtual base classes of TYPE. In G++
4052 3.2, we included virtual bases in the direct base class
4053 loop above, which results in incorrect results; the
4054 correct offsets for virtual bases are only known when
4055 working with the most derived type. */
4059 {
4061 f,
4063 offset,
4065 offsets,
4066 max_offset,
4070 }
4071 else
4072 {
4073 /* We still have to walk the primary base, if it is
4074 virtual. (If it is non-virtual, then it was walked
4075 above.) */
4081 {
4082 r = (walk_subobject_offsets
4087 }
4088 }
4089 }
4091 /* Iterate through the fields of TYPE. */
4096 {
4097 tree field_offset;
4102 f,
4104 offset,
4105 field_offset),
4106 offsets,
4107 max_offset,
4111 }
4112 }
4114 {
4117 tree index;
4119 /* Avoid recursing into objects that are not interesting. */
4124 /* Step through each of the elements in the array. */
4128 {
4130 f,
4131 offset,
4132 offsets,
4133 max_offset,
4139 /* If this new OFFSET is bigger than the MAX_OFFSET, then
4140 there's no point in iterating through the remaining
4141 elements of the array. */
4144 }
4145 }
4148 }
4150 /* Record all of the empty subobjects of TYPE (either a type or a
4151 binfo). If IS_DATA_MEMBER is true, then a non-static data member
4152 is being placed at OFFSET; otherwise, it is a base class that is
4153 being placed at OFFSET. */
4155 static void
4157 tree offset,
4158 splay_tree offsets,
4160 {
4161 tree max_offset;
4162 /* If recording subobjects for a non-static data member or a
4163 non-empty base class , we do not need to record offsets beyond
4164 the size of the biggest empty class. Additional data members
4165 will go at the end of the class. Additional base classes will go
4166 either at offset zero (if empty, in which case they cannot
4167 overlap with offsets past the size of the biggest empty class) or
4168 at the end of the class.
4170 However, if we are placing an empty base class, then we must record
4171 all offsets, as either the empty class is at offset zero (where
4172 other empty classes might later be placed) or at the end of the
4173 class (where other objects might then be placed, so other empty
4174 subobjects might later overlap). */
4178 else
4182 }
4184 /* Returns nonzero if any of the empty subobjects of TYPE (located at
4185 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
4186 virtual bases of TYPE are examined. */
4188 static int
4190 tree offset,
4191 splay_tree offsets,
4193 {
4194 splay_tree_node max_node;
4196 /* Get the node in OFFSETS that indicates the maximum offset where
4197 an empty subobject is located. */
4199 /* If there aren't any empty subobjects, then there's no point in
4200 performing this check. */
4206 vbases_p);
4207 }
4209 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
4210 non-static data member of the type indicated by RLI. BINFO is the
4211 binfo corresponding to the base subobject, OFFSETS maps offsets to
4212 types already located at those offsets. This function determines
4213 the position of the DECL. */
4215 static void
4217 tree decl,
4218 tree binfo,
4219 splay_tree offsets)
4220 {
4223 tree type;
4226 {
4227 /* For the purposes of determining layout conflicts, we want to
4228 use the class type of BINFO; TREE_TYPE (DECL) will be the
4229 CLASSTYPE_AS_BASE version, which does not contain entries for
4230 zero-sized bases. */
4233 }
4234 else
4235 {
4238 }
4240 /* Try to place the field. It may take more than one try if we have
4241 a hard time placing the field without putting two objects of the
4242 same type at the same address. */
4244 {
4247 /* Place this field. */
4251 /* We have to check to see whether or not there is already
4252 something of the same type at the offset we're about to use.
4253 For example, consider:
4255 struct S {};
4256 struct T : public S { int i; };
4257 struct U : public S, public T {};
4259 Here, we put S at offset zero in U. Then, we can't put T at
4260 offset zero -- its S component would be at the same address
4261 as the S we already allocated. So, we have to skip ahead.
4262 Since all data members, including those whose type is an
4263 empty class, have nonzero size, any overlap can happen only
4264 with a direct or indirect base-class -- it can't happen with
4265 a data member. */
4266 /* In a union, overlap is permitted; all members are placed at
4267 offset zero. */
4272 {
4273 /* Strip off the size allocated to this field. That puts us
4274 at the first place we could have put the field with
4275 proper alignment. */
4278 /* Bump up by the alignment required for the type. */
4279 rli->bitpos
4285 }
4288 {
4289 /* Before ABI v9, we were giving nullptr_t alignment of 1; if
4290 the offset wasn't aligned like a pointer when we started to
4291 layout this field, that affects its position. */
4294 {
4297 "alignment of %qD increased in -fabi-version=9 "
4299 else
4302 }
4304 }
4305 else
4306 /* There was no conflict. We're done laying out this field. */
4308 }
4310 /* Now that we know where it will be placed, update its
4311 BINFO_OFFSET. */
4313 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
4314 this point because their BINFO_OFFSET is copied from another
4315 hierarchy. Therefore, we may not need to add the entire
4316 OFFSET. */
4322 }
4324 /* Returns true if TYPE is empty and OFFSET is nonzero. */
4326 static int
4328 tree offset,
4330 {
4332 }
4334 /* Layout the empty base BINFO. EOC indicates the byte currently just
4335 past the end of the class, and should be correctly aligned for a
4336 class of the type indicated by BINFO; OFFSETS gives the offsets of
4337 the empty bases allocated so far. T is the most derived
4338 type. Return nonzero iff we added it at the end. */
4340 static bool
4343 {
4344 tree alignment;
4348 /* This routine should only be used for empty classes. */
4353 propagate_binfo_offsets
4357 /* This is an empty base class. We first try to put it at offset
4358 zero. */
4361 offsets,
4363 {
4364 /* That didn't work. Now, we move forward from the next
4365 available spot in the class. */
4369 {
4372 offsets,
4374 /* We finally found a spot where there's no overlap. */
4377 /* There's overlap here, too. Bump along to the next spot. */
4379 }
4380 }
4383 {
4388 }
4391 }
4393 /* Layout the base given by BINFO in the class indicated by RLI.
4394 *BASE_ALIGN is a running maximum of the alignments of
4395 any base class. OFFSETS gives the location of empty base
4396 subobjects. T is the most derived type. Return nonzero if the new
4397 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4398 *NEXT_FIELD, unless BINFO is for an empty base class.
4400 Returns the location at which the next field should be inserted. */
4405 {
4410 /* This error is now reported in xref_tag, thus giving better
4411 location information. */
4414 /* Place the base class. */
4416 {
4417 tree decl;
4419 /* The containing class is non-empty because it has a non-empty
4420 base class. */
4423 /* Create the FIELD_DECL. */
4430 {
4438 /* Try to place the field. It may take more than one try if we
4439 have a hard time placing the field without putting two
4440 objects of the same type at the same address. */
4442 /* Add the new FIELD_DECL to the list of fields for T. */
4446 }
4447 }
4448 else
4449 {
4450 tree eoc;
4453 /* On some platforms (ARM), even empty classes will not be
4454 byte-aligned. */
4459 /* A nearly-empty class "has no proper base class that is empty,
4460 not morally virtual, and at an offset other than zero." */
4462 {
4465 /* The check above (used in G++ 3.2) is insufficient because
4466 an empty class placed at offset zero might itself have an
4467 empty base at a nonzero offset. */
4469 empty_base_at_nonzero_offset_p,
4470 size_zero_node,
4475 }
4477 /* We do not create a FIELD_DECL for empty base classes because
4478 it might overlap some other field. We want to be able to
4479 create CONSTRUCTORs for the class by iterating over the
4480 FIELD_DECLs, and the back end does not handle overlapping
4481 FIELD_DECLs. */
4483 /* An empty virtual base causes a class to be non-empty
4484 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4485 here because that was already done when the virtual table
4486 pointer was created. */
4487 }
4489 /* Record the offsets of BINFO and its base subobjects. */
4492 offsets,
4496 }
4498 /* Layout all of the non-virtual base classes. Record empty
4499 subobjects in OFFSETS. T is the most derived type. Return nonzero
4500 if the type cannot be nearly empty. The fields created
4501 corresponding to the base classes will be inserted at
4502 *NEXT_FIELD. */
4504 static void
4507 {
4508 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4509 subobjects. */
4514 /* The primary base class is always allocated first. */
4519 /* Now allocate the rest of the bases. */
4521 {
4522 tree base_binfo;
4526 /* The primary base was already allocated above, so we don't
4527 need to allocate it again here. */
4531 /* Virtual bases are added at the end (a primary virtual base
4532 will have already been added). */
4538 }
4539 }
4541 /* Go through the TYPE_METHODS of T issuing any appropriate
4542 diagnostics, figuring out which methods override which other
4543 methods, and so forth. */
4545 static void
4547 {
4548 tree x;
4551 {
4555 /* The name of the field is the original field name
4556 Save this in auxiliary field for later overloading. */
4558 {
4562 }
4563 /* All user-provided destructors are non-trivial.
4564 Constructors and assignment ops are handled in
4565 grok_special_member_properties. */
4571 "%<transaction_safe_dynamic%> may only be specified for "
4573 }
4574 }
4576 /* FN is a constructor or destructor. Clone the declaration to create
4577 a specialized in-charge or not-in-charge version, as indicated by
4578 NAME. */
4580 static tree
4582 {
4583 tree parms;
4584 tree clone;
4586 /* Copy the function. */
4588 /* Reset the function name. */
4590 /* Remember where this function came from. */
4592 /* Make it easy to find the CLONE given the FN. */
4596 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4598 {
4605 }
4606 else
4607 {
4608 // Clone constraints.
4612 }
4617 /* There's no pending inline data for this function. */
4621 /* The base-class destructor is not virtual. */
4623 {
4627 }
4629 /* If there was an in-charge parameter, drop it from the function
4630 type. */
4632 {
4633 tree basetype;
4634 tree parmtypes;
4635 tree exceptions;
4640 /* Skip the `this' parameter. */
4642 /* Skip the in-charge parameter. */
4644 /* And the VTT parm, in a complete [cd]tor. */
4648 /* If this is subobject constructor or destructor, add the vtt
4649 parameter. */
4653 parmtypes);
4656 exceptions);
4660 }
4662 /* Copy the function parameters. */
4664 /* Remove the in-charge parameter. */
4666 {
4670 }
4671 /* And the VTT parm, in a complete [cd]tor. */
4673 {
4676 else
4677 {
4681 }
4682 }
4685 {
4688 }
4690 /* Create the RTL for this function. */
4695 }
4697 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4698 not invoke this function directly.
4700 For a non-thunk function, returns the address of the slot for storing
4701 the function it is a clone of. Otherwise returns NULL_TREE.
4703 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4704 cloned_function is unset. This is to support the separate
4705 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4706 on a template makes sense, but not the former. */
4708 tree *
4710 {
4718 {
4719 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4722 else
4723 #endif
4725 }
4730 else
4732 }
4734 /* Produce declarations for all appropriate clones of FN. If
4735 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4736 CLASTYPE_METHOD_VEC as well. */
4738 void
4740 {
4741 tree clone;
4743 /* Avoid inappropriate cloning. */
4749 {
4750 /* For each constructor, we need two variants: an in-charge version
4751 and a not-in-charge version. */
4758 }
4759 else
4760 {
4763 /* For each destructor, we need three variants: an in-charge
4764 version, a not-in-charge version, and an in-charge deleting
4765 version. We clone the deleting version first because that
4766 means it will go second on the TYPE_METHODS list -- and that
4767 corresponds to the correct layout order in the virtual
4768 function table.
4770 For a non-virtual destructor, we do not build a deleting
4771 destructor. */
4773 {
4777 }
4784 }
4786 /* Note that this is an abstract function that is never emitted. */
4788 }
4790 /* DECL is an in charge constructor, which is being defined. This will
4791 have had an in class declaration, from whence clones were
4792 declared. An out-of-class definition can specify additional default
4793 arguments. As it is the clones that are involved in overload
4794 resolution, we must propagate the information from the DECL to its
4795 clones. */
4797 void
4799 {
4800 tree clone;
4804 {
4811 /* Skip the 'this' parameter. */
4827 {
4832 {
4833 /* A default parameter has been added. Adjust the
4834 clone's parameters. */
4838 tree type;
4843 {
4846 clone_parms);
4848 }
4851 clone_parms);
4860 }
4861 }
4863 }
4864 }
4866 /* For each of the constructors and destructors in T, create an
4867 in-charge and not-in-charge variant. */
4869 static void
4871 {
4872 tree fns;
4874 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4875 out now. */
4883 }
4885 /* Deduce noexcept for a destructor DTOR. */
4887 void
4889 {
4891 {
4894 }
4895 }
4897 /* For each destructor in T, deduce noexcept:
4899 12.4/3: A declaration of a destructor that does not have an
4900 exception-specification is implicitly considered to have the
4901 same exception-specification as an implicit declaration (15.4). */
4903 static void
4905 {
4906 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4907 out now. */
4913 }
4915 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4916 of TYPE for virtual functions which FNDECL overrides. Return a
4917 mask of the tm attributes found therein. */
4919 static int
4921 {
4923 tree base_binfo;
4927 {
4935 {
4939 else
4942 }
4943 else
4945 }
4948 }
4950 /* Subroutine of set_method_tm_attributes. Handle the checks and
4951 inheritance for one virtual method FNDECL. */
4953 static void
4955 {
4956 tree tm_attr;
4961 /* If FNDECL doesn't actually override anything (i.e. T is the
4962 class that first declares FNDECL virtual), then we're done. */
4969 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4970 tm_pure must match exactly, otherwise no weakening of
4971 tm_safe > tm_callable > nothing. */
4972 /* ??? The tm_pure attribute didn't make the transition to the
4973 multivendor language spec. */
4975 {
4977 {
4980 }
4981 }
4982 /* If the overridden function is tm_pure, then FNDECL must be. */
4985 /* Look for base class combinations that cannot be satisfied. */
4987 {
4993 }
4994 /* If FNDECL did not declare an attribute, then inherit the most
4995 restrictive one. */
4997 {
4999 }
5000 /* Otherwise validate that we're not weaker than a function
5001 that is being overridden. */
5002 else
5003 {
5007 }
5010 err_override:
5014 }
5016 /* For each of the methods in T, propagate a class-level tm attribute. */
5018 static void
5020 {
5023 /* Don't bother collecting tm attributes if transactional memory
5024 support is not enabled. */
5028 /* Process virtual methods first, as they inherit directly from the
5029 base virtual function and also require validation of new attributes. */
5031 {
5032 tree vchain;
5035 {
5040 }
5041 }
5043 /* If the class doesn't have an attribute, nothing more to do. */
5048 /* Any method that does not yet have a tm attribute inherits
5049 the one from the class. */
5051 {
5054 }
5055 }
5057 /* Returns true iff class T has a user-defined constructor other than
5058 the default constructor. */
5060 bool
5062 {
5063 tree fns;
5069 {
5076 }
5079 }
5081 /* Returns the defaulted constructor if T has one. Otherwise, returns
5082 NULL_TREE. */
5084 tree
5086 {
5093 {
5097 {
5103 }
5104 }
5107 }
5109 /* Returns true iff FN is a user-provided function, i.e. user-declared
5110 and not defaulted at its first declaration; or explicit, private,
5111 protected, or non-const. */
5113 bool
5115 {
5118 else
5122 }
5124 /* Returns true iff class T has a user-provided constructor. */
5126 bool
5128 {
5129 tree fns;
5137 /* This can happen in error cases; avoid crashing. */
5146 }
5148 /* Returns true iff class T has a user-provided or explicit constructor. */
5150 bool
5152 {
5153 tree fns;
5161 /* This can happen in error cases; avoid crashing. */
5166 {
5170 }
5173 }
5175 /* Returns true iff class T has a non-user-provided (i.e. implicitly
5176 declared or explicitly defaulted in the class body) default
5177 constructor. */
5179 bool
5181 {
5182 tree fns;
5190 {
5196 }
5199 }
5201 /* TYPE is being used as a virtual base, and has a non-trivial move
5202 assignment. Return true if this is due to there being a user-provided
5203 move assignment in TYPE or one of its subobjects; if there isn't, then
5204 multiple move assignment can't cause any harm. */
5206 bool
5208 {
5209 /* Does the type itself have a user-provided move assignment operator? */
5213 {
5217 }
5219 /* Do any of its bases? */
5221 tree base_binfo;
5226 /* Or non-static data members? */
5228 {
5233 }
5235 /* Seems not. */
5237 }
5239 /* If default-initialization leaves part of TYPE uninitialized, returns
5240 a DECL for the field or TYPE itself (DR 253). */
5242 tree
5244 {
5255 {
5259 }
5264 {
5268 }
5271 }
5273 /* Returns true iff for class T, a trivial synthesized default constructor
5274 would be constexpr. */
5276 bool
5278 {
5279 /* A defaulted trivial default constructor is constexpr
5280 if there is nothing to initialize. */
5283 }
5285 /* Returns true iff class T has a constexpr default constructor. */
5287 bool
5289 {
5290 tree fns;
5293 {
5294 /* The caller should have stripped an enclosing array. */
5297 }
5299 {
5302 /* Non-trivial, we need to check subobject constructors. */
5304 }
5307 }
5309 /* Returns true iff class TYPE has a virtual destructor. */
5311 bool
5313 {
5314 tree dtor;
5322 }
5324 /* Returns true iff class T has a move constructor. */
5326 bool
5328 {
5329 tree fns;
5332 {
5335 }
5345 }
5347 /* Returns true iff class T has a move assignment operator. */
5349 bool
5351 {
5352 tree fns;
5355 {
5358 }
5366 }
5368 /* Returns true iff class T has a move constructor that was explicitly
5369 declared in the class body. Note that this is different from
5370 "user-provided", which doesn't include functions that are defaulted in
5371 the class. */
5373 bool
5375 {
5376 tree fns;
5385 {
5389 }
5392 }
5394 /* Returns true iff class T has a move assignment operator that was
5395 explicitly declared in the class body. */
5397 bool
5399 {
5400 tree fns;
5407 {
5411 }
5414 }
5416 /* Nonzero if we need to build up a constructor call when initializing an
5417 object of this class, either because it has a user-declared constructor
5418 or because it doesn't have a default constructor (so we need to give an
5419 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5420 what you care about is whether or not an object can be produced by a
5421 constructor (e.g. so we don't set TREE_READONLY on const variables of
5422 such type); use this function when what you care about is whether or not
5423 to try to call a constructor to create an object. The latter case is
5424 the former plus some cases of constructors that cannot be called. */
5426 bool
5428 {
5429 tree inner;
5439 /* A user-declared constructor might be private, and a constructor might
5440 be trivial but deleted. */
5443 {
5448 }
5450 }
5452 /* Like type_build_ctor_call, but for destructors. */
5454 bool
5456 {
5457 tree inner;
5466 /* A user-declared destructor might be private, and a destructor might
5467 be trivial but deleted. */
5470 {
5475 }
5477 }
5479 /* Remove all zero-width bit-fields from T. */
5481 static void
5483 {
5488 {
5491 /* We should not be confused by the fact that grokbitfield
5492 temporarily sets the width of the bit field into
5493 DECL_INITIAL (*fieldsp).
5494 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5495 to that width. */
5499 else
5501 }
5502 }
5504 /* Returns TRUE iff we need a cookie when dynamically allocating an
5505 array whose elements have the indicated class TYPE. */
5507 static bool
5509 {
5510 tree fns;
5515 /* If there's a non-trivial destructor, we need a cookie. In order
5516 to iterate through the array calling the destructor for each
5517 element, we'll have to know how many elements there are. */
5521 /* If the usual deallocation function is a two-argument whose second
5522 argument is of type `size_t', then we have to pass the size of
5523 the array to the deallocation function, so we will need to store
5524 a cookie. */
5528 /* If there are no `operator []' members, or the lookup is
5529 ambiguous, then we don't need a cookie. */
5532 /* Loop through all of the functions. */
5534 {
5535 tree fn;
5536 tree second_parm;
5538 /* Select the current function. */
5540 /* See if this function is a one-argument delete function. If
5541 it is, then it will be the usual deallocation function. */
5545 /* Do not consider this function if its second argument is an
5546 ellipsis. */
5549 /* Otherwise, if we have a two-argument function and the second
5550 argument is `size_t', it will be the usual deallocation
5551 function -- unless there is one-argument function, too. */
5555 }
5558 }
5560 /* Finish computing the `literal type' property of class type T.
5562 At this point, we have already processed base classes and
5563 non-static data members. We need to check whether the copy
5564 constructor is trivial, the destructor is trivial, and there
5565 is a trivial default constructor or at least one constexpr
5566 constructor other than the copy constructor. */
5568 static void
5570 {
5571 tree fn;
5587 {
5590 {
5594 }
5595 }
5596 }
5598 /* T is a non-literal type used in a context which requires a constant
5599 expression. Explain why it isn't literal. */
5601 void
5603 {
5613 /* Already explained. */
5622 {
5624 "default constructor, and has no constexpr constructor that "
5627 {
5628 /* Note that we can't simply call locate_ctor because when the
5629 constructor is deleted it just returns NULL_TREE. */
5630 tree fns;
5632 {
5639 {
5642 else
5645 }
5646 }
5647 }
5648 }
5649 else
5650 {
5654 {
5657 {
5662 }
5663 }
5665 {
5666 tree ftype;
5671 {
5674 field);
5677 }
5681 }
5682 }
5683 }
5685 /* Check the validity of the bases and members declared in T. Add any
5686 implicitly-generated functions (like copy-constructors and
5687 assignment operators). Compute various flag bits (like
5688 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5689 level: i.e., independently of the ABI in use. */
5691 static void
5693 {
5694 /* Nonzero if the implicitly generated copy constructor should take
5695 a non-const reference argument. */
5697 /* Nonzero if the implicitly generated assignment operator
5698 should take a non-const reference argument. */
5700 tree access_decls;
5703 tree fn;
5705 /* By default, we use const reference arguments and generate default
5706 constructors. */
5710 /* Check all the base-classes. */
5714 /* Deduce noexcept on destructors. This needs to happen after we've set
5715 triviality flags appropriately for our bases. */
5719 /* Check all the method declarations. */
5722 /* Save the initial values of these flags which only indicate whether
5723 or not the class has user-provided functions. As we analyze the
5724 bases and members we can set these flags for other reasons. */
5728 /* Check all the data member declarations. We cannot call
5729 check_field_decls until we have called check_bases check_methods,
5730 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5731 being set appropriately. */
5736 /* A nearly-empty class has to be vptr-containing; a nearly empty
5737 class contains just a vptr. */
5741 /* Do some bookkeeping that will guide the generation of implicitly
5742 declared member functions. */
5745 /* We need to call a constructor for this class if it has a
5746 user-provided constructor, or if the default constructor is going
5747 to initialize the vptr. (This is not an if-and-only-if;
5748 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5749 themselves need constructing.) */
5752 /* [dcl.init.aggr]
5754 An aggregate is an array or a class with no user-provided
5755 constructors ... and no virtual functions.
5757 Again, other conditions for being an aggregate are checked
5758 elsewhere. */
5762 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5763 retain the old definition internally for ABI reasons. */
5772 /* If the only explicitly declared default constructor is user-provided,
5773 set TYPE_HAS_COMPLEX_DFLT. */
5779 /* Warn if a public base of a polymorphic type has an accessible
5780 non-virtual destructor. It is only now that we know the class is
5781 polymorphic. Although a polymorphic base will have a already
5782 been diagnosed during its definition, we warn on use too. */
5784 {
5787 tree base_binfo;
5791 {
5799 basetype);
5800 }
5801 }
5803 /* If the class has no user-declared constructor, but does have
5804 non-static const or reference data members that can never be
5805 initialized, issue a warning. */
5807 /* Classes with user-declared constructors are presumed to
5808 initialize these members. */
5810 /* Aggregates can be initialized with brace-enclosed
5811 initializers. */
5813 {
5814 tree field;
5817 {
5818 tree type;
5835 }
5836 }
5838 /* Synthesize any needed methods. */
5840 cant_have_const_ctor,
5841 no_const_asn_ref);
5843 /* Check defaulted declarations here so we have cant_have_const_ctor
5844 and don't need to worry about clones. */
5847 {
5850 {
5851 bool imp_const_p
5857 /* If the function is defaulted outside the class, we just
5858 give the synthesis error. */
5861 }
5863 }
5866 {
5867 /* "This class type is not an aggregate." */
5869 }
5871 /* Compute the 'literal type' property before we
5872 do anything with non-static member functions. */
5875 /* Create the in-charge and not-in-charge variants of constructors
5876 and destructors. */
5879 /* Process the using-declarations. */
5883 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5886 /* Figure out whether or not we will need a cookie when dynamically
5887 allocating an array of this type. */
5890 }
5892 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5893 accordingly. If a new vfield was created (because T doesn't have a
5894 primary base class), then the newly created field is returned. It
5895 is not added to the TYPE_FIELDS list; it is the caller's
5896 responsibility to do that. Accumulate declared virtual functions
5897 on VIRTUALS_P. */
5899 static tree
5901 {
5902 tree fn;
5904 /* Collect the virtual functions declared in T. */
5909 {
5918 }
5920 /* If we couldn't find an appropriate base class, create a new field
5921 here. Even if there weren't any new virtual functions, we might need a
5922 new virtual function table if we're supposed to include vptrs in
5923 all classes that need them. */
5925 {
5926 /* We build this decl with vtbl_ptr_type_node, which is a
5927 `vtable_entry_type*'. It might seem more precise to use
5928 `vtable_entry_type (*)[N]' where N is the number of virtual
5929 functions. However, that would require the vtable pointer in
5930 base classes to have a different type than the vtable pointer
5931 in derived classes. We could make that happen, but that
5932 still wouldn't solve all the problems. In particular, the
5933 type-based alias analysis code would decide that assignments
5934 to the base class vtable pointer can't alias assignments to
5935 the derived class vtable pointer, since they have different
5936 types. Thus, in a derived class destructor, where the base
5937 class constructor was inlined, we could generate bad code for
5938 setting up the vtable pointer.
5940 Therefore, we use one type for all vtable pointers. We still
5941 use a type-correct type; it's just doesn't indicate the array
5942 bounds. That's better than using `void*' or some such; it's
5943 cleaner, and it let's the alias analysis code know that these
5944 stores cannot alias stores to void*! */
5945 tree field;
5958 /* This class is non-empty. */
5962 }
5965 }
5967 /* Add OFFSET to all base types of BINFO which is a base in the
5968 hierarchy dominated by T.
5970 OFFSET, which is a type offset, is number of bytes. */
5972 static void
5974 {
5976 tree primary_binfo;
5977 tree base_binfo;
5979 /* Update BINFO's offset. */
5984 offset));
5986 /* Find the primary base class. */
5992 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5993 downwards. */
5995 {
5996 /* Don't do the primary base twice. */
6004 }
6005 }
6007 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
6008 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
6009 empty subobjects of T. */
6011 static void
6013 {
6014 tree vbase;
6021 /* Find the last field. The artificial fields created for virtual
6022 bases will go after the last extant field to date. */
6027 /* Go through the virtual bases, allocating space for each virtual
6028 base that is not already a primary base class. These are
6029 allocated in inheritance graph order. */
6031 {
6036 {
6037 /* This virtual base is not a primary base of any class in the
6038 hierarchy, so we have to add space for it. */
6041 }
6042 }
6043 }
6045 /* Returns the offset of the byte just past the end of the base class
6046 BINFO. */
6048 static tree
6050 {
6051 tree size;
6056 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
6057 allocate some space for it. It cannot have virtual bases, so
6058 TYPE_SIZE_UNIT is fine. */
6060 else
6064 }
6066 /* Returns the offset of the byte just past the end of the base class
6067 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
6068 only non-virtual bases are included. */
6070 static tree
6072 {
6075 tree binfo;
6076 tree base_binfo;
6077 tree offset;
6082 {
6092 }
6097 {
6101 }
6104 }
6106 /* Warn about bases of T that are inaccessible because they are
6107 ambiguous. For example:
6109 struct S {};
6110 struct T : public S {};
6111 struct U : public S, public T {};
6113 Here, `(S*) new U' is not allowed because there are two `S'
6114 subobjects of U. */
6116 static void
6118 {
6121 tree basetype;
6122 tree binfo;
6123 tree base_binfo;
6125 /* If there are no repeated bases, nothing can be ambiguous. */
6129 /* Check direct bases. */
6132 {
6138 }
6140 /* Check for ambiguous virtual bases. */
6144 {
6150 }
6151 }
6153 /* Compare two INTEGER_CSTs K1 and K2. */
6155 static int
6157 {
6159 }
6161 /* Increase the size indicated in RLI to account for empty classes
6162 that are "off the end" of the class. */
6164 static void
6166 {
6167 tree eoc;
6168 tree rli_size;
6170 /* It might be the case that we grew the class to allocate a
6171 zero-sized base class. That won't be reflected in RLI, yet,
6172 because we are willing to overlay multiple bases at the same
6173 offset. However, now we need to make sure that RLI is big enough
6174 to reflect the entire class. */
6180 {
6181 /* The size should have been rounded to a whole byte. */
6184 rli->bitpos
6193 }
6194 }
6196 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
6197 BINFO_OFFSETs for all of the base-classes. Position the vtable
6198 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
6200 static void
6202 {
6203 tree non_static_data_members;
6204 tree field;
6205 tree vptr;
6206 record_layout_info rli;
6207 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
6208 types that appear at that offset. */
6209 splay_tree empty_base_offsets;
6210 /* True if the last field laid out was a bit-field. */
6212 /* The location at which the next field should be inserted. */
6214 /* T, as a base class. */
6215 tree base_t;
6217 /* Keep track of the first non-static data member. */
6220 /* Start laying out the record. */
6223 /* Mark all the primary bases in the hierarchy. */
6226 /* Create a pointer to our virtual function table. */
6229 /* The vptr is always the first thing in the class. */
6231 {
6236 }
6237 else
6240 /* Build FIELD_DECLs for all of the non-virtual base-types. */
6245 /* Layout the non-static data members. */
6247 {
6248 tree type;
6249 tree padding;
6251 /* We still pass things that aren't non-static data members to
6252 the back end, in case it wants to do something with them. */
6254 {
6256 /* If the static data member has incomplete type, keep track
6257 of it so that it can be completed later. (The handling
6258 of pending statics in finish_record_layout is
6259 insufficient; consider:
6261 struct S1;
6262 struct S2 { static S1 s1; };
6264 At this point, finish_record_layout will be called, but
6265 S1 is still incomplete.) */
6267 {
6269 /* The visibility of static data members is determined
6270 at their point of declaration, not their point of
6271 definition. */
6273 }
6275 }
6283 /* If this field is a bit-field whose width is greater than its
6284 type, then there are some special rules for allocating
6285 it. */
6288 {
6290 tree integer_type;
6292 /* We must allocate the bits as if suitably aligned for the
6293 longest integer type that fits in this many bits. type
6294 of the field. Then, we are supposed to use the left over
6295 bits as additional padding. */
6304 /* ITK now indicates a type that is too large for the
6305 field. We have to back up by one to find the largest
6306 type that fits. */
6307 do
6308 {
6313 /* Figure out how much additional padding is required. */
6315 {
6317 /* In a union, the padding field must have the full width
6318 of the bit-field; all fields start at offset zero. */
6320 else
6323 }
6325 /* An unnamed bitfield does not normally affect the
6326 alignment of the containing class on a target where
6327 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
6328 make any exceptions for unnamed bitfields when the
6329 bitfields are longer than their types. Therefore, we
6330 temporarily give the field a name. */
6332 {
6335 }
6341 empty_base_offsets);
6344 /* Now that layout has been performed, set the size of the
6345 field to the size of its declared type; the rest of the
6346 field is effectively invisible. */
6348 /* We must also reset the DECL_MODE of the field. */
6350 }
6351 else
6353 empty_base_offsets);
6355 /* Remember the location of any empty classes in FIELD. */
6358 empty_base_offsets,
6361 /* If a bit-field does not immediately follow another bit-field,
6362 and yet it starts in the middle of a byte, we have failed to
6363 comply with the ABI. */
6366 /* The TREE_NO_WARNING flag gets set by Objective-C when
6367 laying out an Objective-C class. The ObjC ABI differs
6368 from the C++ ABI, and so we do not want a warning
6369 here. */
6371 && !last_field_was_bitfield
6374 bitsize_unit_node)))
6376 "offset of %qD is not ABI-compliant and may "
6379 /* The middle end uses the type of expressions to determine the
6380 possible range of expression values. In order to optimize
6381 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6382 must be made aware of the width of "i", via its type.
6384 Because C++ does not have integer types of arbitrary width,
6385 we must (for the purposes of the front end) convert from the
6386 type assigned here to the declared type of the bitfield
6387 whenever a bitfield expression is used as an rvalue.
6388 Similarly, when assigning a value to a bitfield, the value
6389 must be converted to the type given the bitfield here. */
6391 {
6396 {
6403 }
6404 }
6406 /* If we needed additional padding after this field, add it
6407 now. */
6409 {
6410 tree padding_field;
6413 FIELD_DECL,
6414 NULL_TREE,
6415 char_type_node);
6422 NULL_TREE,
6423 empty_base_offsets);
6424 }
6427 }
6430 {
6431 /* Make sure that we are on a byte boundary so that the size of
6432 the class without virtual bases will always be a round number
6433 of bytes. */
6436 }
6438 /* Delete all zero-width bit-fields from the list of fields. Now
6439 that the type is laid out they are no longer important. */
6442 /* Create the version of T used for virtual bases. We do not use
6443 make_class_type for this version; this is an artificial type. For
6444 a POD type, we just reuse T. */
6446 {
6449 /* Set the size and alignment for the new type. */
6450 tree eoc;
6452 /* If the ABI version is not at least two, and the last
6453 field was a bit-field, RLI may not be on a byte
6454 boundary. In particular, rli_size_unit_so_far might
6455 indicate the last complete byte, while rli_size_so_far
6456 indicates the total number of bits used. Therefore,
6457 rli_size_so_far, rather than rli_size_unit_so_far, is
6458 used to compute TYPE_SIZE_UNIT. */
6466 eoc);
6476 /* Copy the fields from T. */
6480 {
6482 FIELD_DECL,
6492 }
6494 /* Record the base version of the type. */
6497 }
6498 else
6501 /* Every empty class contains an empty class. */
6505 /* Set the TYPE_DECL for this type to contain the right
6506 value for DECL_OFFSET, so that we can use it as part
6507 of a COMPONENT_REF for multiple inheritance. */
6510 /* Now fix up any virtual base class types that we left lying
6511 around. We must get these done before we try to lay out the
6512 virtual function table. As a side-effect, this will remove the
6513 base subobject fields. */
6516 /* Make sure that empty classes are reflected in RLI at this
6517 point. */
6520 /* Make sure not to create any structures with zero size. */
6526 /* If this is a non-POD, declaring it packed makes a difference to how it
6527 can be used as a field; don't let finalize_record_size undo it. */
6531 /* Let the back end lay out the type. */
6540 /* Warn about bases that can't be talked about due to ambiguity. */
6543 /* Now that we're done with layout, give the base fields the real types. */
6548 /* Clean up. */
6555 }
6557 /* Determine the "key method" for the class type indicated by TYPE,
6558 and set CLASSTYPE_KEY_METHOD accordingly. */
6560 void
6562 {
6563 tree method;
6566 || processing_template_decl
6571 /* The key method is the first non-pure virtual function that is not
6572 inline at the point of class definition. On some targets the
6573 key function may not be inline; those targets should not call
6574 this function until the end of the translation unit. */
6581 {
6584 }
6587 }
6590 /* Allocate and return an instance of struct sorted_fields_type with
6591 N fields. */
6595 {
6602 }
6605 /* Perform processing required when the definition of T (a class type)
6606 is complete. */
6608 void
6610 {
6611 tree x;
6612 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6616 {
6621 }
6623 /* If this type was previously laid out as a forward reference,
6624 make sure we lay it out again. */
6628 /* Make assumptions about the class; we'll reset the flags if
6629 necessary. */
6635 /* Do end-of-class semantic processing: checking the validity of the
6636 bases and members and add implicitly generated methods. */
6639 /* Find the key method. */
6641 {
6642 /* The Itanium C++ ABI permits the key method to be chosen when
6643 the class is defined -- even though the key method so
6644 selected may later turn out to be an inline function. On
6645 some systems (such as ARM Symbian OS) the key method cannot
6646 be determined until the end of the translation unit. On such
6647 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6648 will cause the class to be added to KEYED_CLASSES. Then, in
6649 finish_file we will determine the key method. */
6653 /* If a polymorphic class has no key method, we may emit the vtable
6654 in every translation unit where the class definition appears. If
6655 we're devirtualizing, we can look into the vtable even if we
6656 aren't emitting it. */
6659 }
6661 /* Layout the class itself. */
6664 /* We use the base type for trivial assignments, and hence it
6665 needs a mode. */
6670 /* If necessary, create the primary vtable for this class. */
6672 {
6673 /* We must enter these virtuals into the table. */
6677 /* Here we know enough to change the type of our virtual
6678 function table, but we will wait until later this function. */
6681 /* If we're warning about ABI tags, check the types of the new
6682 virtual functions. */
6686 }
6689 {
6691 tree fn;
6698 /* Add entries for virtual functions introduced by this class. */
6702 /* Set DECL_VINDEX for all functions declared in this class. */
6704 fn;
6706 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6708 {
6712 /* A thunk. We should never be calling this entry directly
6713 from this vtable -- we'd use the entry for the non
6714 thunk base function. */
6718 }
6719 }
6726 /* Complete the rtl for any static member objects of the type we're
6727 working on. */
6734 /* Done with FIELDS...now decide whether to sort these for
6735 faster lookups later.
6737 We use a small number because most searches fail (succeeding
6738 ultimately as the search bores through the inheritance
6739 hierarchy), and we want this failure to occur quickly. */
6743 /* Complain if one of the field types requires lower visibility. */
6746 /* Make the rtl for any new vtables we have created, and unmark
6747 the base types we marked. */
6750 /* Build the VTT for T. */
6753 /* This warning does not make sense for Java classes, since they
6754 cannot have destructors. */
6759 "%q#T has virtual functions and accessible"
6767 /* Class layout, assignment of virtual table slots, etc., is now
6768 complete. Give the back end a chance to tweak the visibility of
6769 the class or perform any other required target modifications. */
6779 /* Finish debugging output for this type. */
6783 {
6786 {
6789 }
6791 {
6794 else
6795 {
6798 }
6800 }
6802 {
6804 "the type of the first field has a different ABI from the "
6807 }
6808 }
6809 }
6811 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6812 equal to THRESHOLD or greater than THRESHOLD. */
6814 static void
6816 {
6819 {
6824 }
6825 }
6827 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6829 void
6831 {
6834 {
6836 int n_fields
6847 }
6848 }
6850 /* When T was built up, the member declarations were added in reverse
6851 order. Rearrange them to declaration order. */
6853 void
6855 {
6856 tree next;
6857 tree prev;
6858 tree x;
6860 /* The following lists are all in reverse order. Put them in
6861 declaration order now. */
6865 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6866 reverse order, so we can't just use nreverse. */
6871 {
6875 }
6877 {
6881 }
6882 }
6884 tree
6886 {
6889 /* Now that we've got all the field declarations, reverse everything
6890 as necessary. */
6896 /* Nadger the current location so that diagnostics point to the start of
6897 the struct, not the end. */
6901 {
6902 tree x;
6908 /* We need to emit an error message if this type was used as a parameter
6909 and it is an abstract type, even if it is a template. We construct
6910 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6911 account and we call complete_vars with this type, which will check
6912 the PARM_DECLS. Note that while the type is being defined,
6913 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6914 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6920 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6921 an enclosing scope is a template class, so that this function be
6922 found by lookup_fnfields_1 when the using declaration is not
6923 instantiated yet. */
6926 {
6931 }
6933 /* Remember current #pragma pack value. */
6936 /* Fix up any variants we've already built. */
6938 {
6943 }
6944 }
6945 else
6949 {
6950 /* People keep complaining that the compiler crashes on an invalid
6951 definition of initializer_list, so I guess we should explicitly
6952 reject it. What the compiler internals care about is that it's a
6953 template and has a pointer field followed by an integer field. */
6956 {
6959 {
6963 }
6964 }
6967 "definition of std::initializer_list does not match "
6969 }
6977 else
6981 /* Lambdas are defined by the LAMBDA_EXPR. */
6986 }
6987 \f
6988 /* Hash table to avoid endless recursion when handling references. */
6991 /* Return the dynamic type of INSTANCE, if known.
6992 Used to determine whether the virtual function table is needed
6993 or not.
6995 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6996 of our knowledge of its type. *NONNULL should be initialized
6997 before this function is called. */
6999 static tree
7001 {
7002 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
7005 {
7009 else
7013 /* This is a call to a constructor, hence it's never zero. */
7015 {
7019 }
7023 /* This is a call to a constructor, hence it's never zero. */
7025 {
7029 }
7038 /* Propagate nonnull. */
7043 CASE_CONVERT:
7049 {
7050 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
7051 with a real object -- given &p->f, p can still be null. */
7053 /* ??? Probably should check DECL_WEAK here. */
7056 }
7060 /* If this component is really a base class reference, then the field
7061 itself isn't definitive. */
7070 {
7074 }
7075 /* fall through... */
7080 {
7084 }
7086 {
7090 /* if we're in a ctor or dtor, we know our type. If
7091 current_class_ptr is set but we aren't in a function, we're in
7092 an NSDMI (and therefore a constructor). */
7097 {
7101 }
7102 }
7104 {
7105 /* We only need one hash table because it is always left empty. */
7107 fixed_type_or_null_ref_ht
7110 /* Reference variables should be references to objects. */
7114 /* Enter the INSTANCE in a table to prevent recursion; a
7115 variable's initializer may refer to the variable
7116 itself. */
7121 {
7122 tree type;
7131 }
7132 }
7137 }
7138 #undef RECUR
7139 }
7141 /* Return nonzero if the dynamic type of INSTANCE is known, and
7142 equivalent to the static type. We also handle the case where
7143 INSTANCE is really a pointer. Return negative if this is a
7144 ctor/dtor. There the dynamic type is known, but this might not be
7145 the most derived base of the original object, and hence virtual
7146 bases may not be laid out according to this type.
7148 Used to determine whether the virtual function table is needed
7149 or not.
7151 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
7152 of our knowledge of its type. *NONNULL should be initialized
7153 before this function is called. */
7155 int
7157 {
7160 tree fixed;
7162 /* processing_template_decl can be false in a template if we're in
7163 instantiate_non_dependent_expr, but we still want to suppress
7164 this check. */
7166 {
7167 /* In a template we only care about the type of the result. */
7171 }
7181 }
7183 \f
7184 void
7186 {
7189 current_class_stack
7197 }
7199 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
7201 static void
7203 {
7204 tree type;
7206 /* We are re-entering the same class we just left, so we don't
7207 have to search the whole inheritance matrix to find all the
7208 decls to bind again. Instead, we install the cached
7209 class_shadowed list and walk through it binding names. */
7212 /* Restore IDENTIFIER_TYPE_VALUE. */
7214 type;
7217 }
7219 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
7220 appropriate for TYPE.
7222 So that we may avoid calls to lookup_name, we cache the _TYPE
7223 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
7225 For multiple inheritance, we perform a two-pass depth-first search
7226 of the type lattice. */
7228 void
7230 {
7231 class_stack_node_t csn;
7235 /* Make sure there is enough room for the new entry on the stack. */
7237 {
7239 current_class_stack
7241 current_class_stack_size);
7242 }
7244 /* Insert a new entry on the class stack. */
7251 current_class_depth++;
7253 /* Now set up the new type. */
7259 /* By default, things in classes are private, while things in
7260 structures or unions are public. */
7262 ? access_private_node
7268 {
7269 /* Forcibly remove any old class remnants. */
7271 }
7277 else
7279 }
7281 /* When we exit a toplevel class scope, we save its binding level so
7282 that we can restore it quickly. Here, we've entered some other
7283 class, so we must invalidate our cache. */
7285 void
7287 {
7289 }
7291 /* Get out of the current class scope. If we were in a class scope
7292 previously, that is the one popped to. */
7294 void
7296 {
7299 current_class_depth--;
7305 }
7307 /* Mark the top of the class stack as hidden. */
7309 void
7311 {
7314 }
7316 /* Mark the top of the class stack as un-hidden. */
7318 void
7320 {
7323 }
7325 /* Returns 1 if the class type currently being defined is either T or
7326 a nested type of T. Returns the type from the current_class_stack,
7327 which might be equivalent to but not equal to T in case of
7328 constrained partial specializations. */
7330 tree
7332 {
7340 /* We start looking from 1 because entry 0 is from global scope,
7341 and has no type. */
7343 {
7344 tree c;
7347 else
7348 {
7352 }
7357 }
7359 }
7361 /* If either current_class_type or one of its enclosing classes are derived
7362 from T, return the appropriate type. Used to determine how we found
7363 something via unqualified lookup. */
7365 tree
7367 {
7370 /* The bases of a dependent type are unknown. */
7381 {
7386 }
7389 }
7391 /* Return the outermost enclosing class type that is still open, or
7392 NULL_TREE. */
7394 tree
7396 {
7403 {
7410 }
7412 }
7414 /* Returns the innermost class type which is not a lambda closure type. */
7416 tree
7418 {
7421 /* We start looking from 1 because entry 0 is from global scope,
7422 and has no type. */
7424 {
7425 tree c;
7428 else
7429 {
7433 }
7438 }
7440 }
7442 /* When entering a class scope, all enclosing class scopes' names with
7443 static meaning (static variables, static functions, types and
7444 enumerators) have to be visible. This recursive function calls
7445 pushclass for all enclosing class contexts until global or a local
7446 scope is reached. TYPE is the enclosed class. */
7448 void
7450 {
7451 /* A namespace might be passed in error cases, like A::B:C. */
7459 }
7461 /* Undoes a push_nested_class call. */
7463 void
7465 {
7471 }
7473 /* Returns the number of extern "LANG" blocks we are nested within. */
7475 int
7477 {
7479 }
7481 /* Set global variables CURRENT_LANG_NAME to appropriate value
7482 so that behavior of name-mangling machinery is correct. */
7484 void
7486 {
7490 {
7492 }
7494 {
7496 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7497 (See record_builtin_java_type in decl.c.) However, that causes
7498 incorrect debug entries if these types are actually used.
7499 So we re-enable debug output after extern "Java". */
7508 }
7510 {
7512 }
7513 else
7515 }
7517 /* Get out of the current language scope. */
7519 void
7521 {
7523 }
7524 \f
7525 /* Type instantiation routines. */
7527 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7528 matches the TARGET_TYPE. If there is no satisfactory match, return
7529 error_mark_node, and issue an error & warning messages under
7530 control of FLAGS. Permit pointers to member function if FLAGS
7531 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7532 a template-id, and EXPLICIT_TARGS are the explicitly provided
7533 template arguments.
7535 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7536 is the base path used to reference those member functions. If
7537 the address is resolved to a member function, access checks will be
7538 performed and errors issued if appropriate. */
7540 static tree
7542 tree overload,
7543 tsubst_flags_t complain,
7545 tree explicit_targs,
7546 tree access_path)
7547 {
7548 /* Here's what the standard says:
7550 [over.over]
7552 If the name is a function template, template argument deduction
7553 is done, and if the argument deduction succeeds, the deduced
7554 arguments are used to generate a single template function, which
7555 is added to the set of overloaded functions considered.
7557 Non-member functions and static member functions match targets of
7558 type "pointer-to-function" or "reference-to-function." Nonstatic
7559 member functions match targets of type "pointer-to-member
7560 function;" the function type of the pointer to member is used to
7561 select the member function from the set of overloaded member
7562 functions. If a nonstatic member function is selected, the
7563 reference to the overloaded function name is required to have the
7564 form of a pointer to member as described in 5.3.1.
7566 If more than one function is selected, any template functions in
7567 the set are eliminated if the set also contains a non-template
7568 function, and any given template function is eliminated if the
7569 set contains a second template function that is more specialized
7570 than the first according to the partial ordering rules 14.5.5.2.
7571 After such eliminations, if any, there shall remain exactly one
7572 selected function. */
7575 /* We store the matches in a TREE_LIST rooted here. The functions
7576 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7577 interoperability with most_specialized_instantiation. */
7579 tree fn;
7580 tree target_fn_type;
7582 /* By the time we get here, we should be seeing only real
7583 pointer-to-member types, not the internal POINTER_TYPE to
7584 METHOD_TYPE representation. */
7590 /* Check that the TARGET_TYPE is reasonable. */
7595 /* This is OK, too. */
7598 /* This is OK, too. This comes from a conversion to reference
7599 type. */
7601 else
7602 {
7608 }
7610 /* Non-member functions and static member functions match targets of type
7611 "pointer-to-function" or "reference-to-function." Nonstatic member
7612 functions match targets of type "pointer-to-member-function;" the
7613 function type of the pointer to member is used to select the member
7614 function from the set of overloaded member functions.
7616 So figure out the FUNCTION_TYPE that we want to match against. */
7619 /* If we can find a non-template function that matches, we can just
7620 use it. There's no point in generating template instantiations
7621 if we're just going to throw them out anyhow. But, of course, we
7622 can only do this when we don't *need* a template function. */
7624 {
7625 tree fns;
7628 {
7632 /* We're not looking for templates just yet. */
7637 /* We're looking for a non-static member, and this isn't
7638 one, or vice versa. */
7641 /* Ignore functions which haven't been explicitly
7642 declared. */
7646 /* See if there's a match. */
7651 }
7652 }
7654 /* Now, if we've already got a match (or matches), there's no need
7655 to proceed to the template functions. But, if we don't have a
7656 match we need to look at them, too. */
7658 {
7659 tree target_arg_types;
7660 tree target_ret_type;
7661 tree fns;
7664 tree arg;
7678 {
7680 tree instantiation;
7681 tree targs;
7684 /* We're only looking for templates. */
7689 /* We're not looking for a non-static member, and this is
7690 one, or vice versa. */
7695 /* If the template has a deduced return type, don't expose it to
7696 template argument deduction. */
7700 /* Try to do argument deduction. */
7707 /* Instantiation failed. */
7710 /* Constraints must be satisfied. This is done before
7711 return type deduction since that instantiates the
7712 function. */
7716 /* And now force instantiation to do return type deduction. */
7718 {
7724 }
7726 /* See if there's a match. */
7731 }
7733 /* Now, remove all but the most specialized of the matches. */
7735 {
7740 NULL_TREE,
7741 NULL_TREE);
7742 }
7743 }
7745 /* Now we should have exactly one function in MATCHES. */
7747 {
7748 /* There were *no* matches. */
7750 {
7753 target_type);
7756 }
7758 }
7760 {
7761 /* There were too many matches. First check if they're all
7762 the same function. */
7767 /* For multi-versioned functions, more than one match is just fine and
7768 decls_match will return false as they are different. */
7776 {
7778 {
7781 target_type);
7783 /* Since print_candidates expects the functions in the
7784 TREE_VALUE slot, we flip them here. */
7789 }
7792 }
7793 }
7795 /* Good, exactly one match. Now, convert it to the correct type. */
7800 {
7808 {
7811 }
7812 }
7814 /* If a pointer to a function that is multi-versioned is requested, the
7815 pointer to the dispatcher function is returned instead. This works
7816 well because indirectly calling the function will dispatch the right
7817 function version at run-time. */
7819 {
7823 /* Mark all the versions corresponding to the dispatcher as used. */
7826 }
7828 /* If we're doing overload resolution purely for the purpose of
7829 determining conversion sequences, we should not consider the
7830 function used. If this conversion sequence is selected, the
7831 function will be marked as used at this point. */
7833 {
7834 /* Make =delete work with SFINAE. */
7839 }
7841 /* We could not check access to member functions when this
7842 expression was originally created since we did not know at that
7843 time to which function the expression referred. */
7845 {
7848 }
7852 else
7853 {
7854 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7855 will mark the function as addressed, but here we must do it
7856 explicitly. */
7860 }
7861 }
7863 /* This function will instantiate the type of the expression given in
7864 RHS to match the type of LHSTYPE. If errors exist, then return
7865 error_mark_node. COMPLAIN is a bit mask. If TF_ERROR is set, then
7866 we complain on errors. If we are not complaining, never modify rhs,
7867 as overload resolution wants to try many possible instantiations, in
7868 the hope that at least one will work.
7870 For non-recursive calls, LHSTYPE should be a function, pointer to
7871 function, or a pointer to member function. */
7873 tree
7875 {
7882 {
7886 }
7889 {
7896 /* Microsoft allows `A::f' to be resolved to a
7897 pointer-to-member. */
7898 ;
7899 else
7900 {
7905 }
7906 }
7909 {
7912 }
7914 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7915 deduce any type information. */
7917 {
7921 }
7923 /* There only a few kinds of expressions that may have a type
7924 dependent on overload resolution. */
7930 /* This should really only be used when attempting to distinguish
7931 what sort of a pointer to function we have. For now, any
7932 arithmetic operation which is not supported on pointers
7933 is rejected as an error. */
7936 {
7938 {
7944 /* Do not lose object's side effects. */
7948 }
7955 /* This can happen if we are forming a pointer-to-member for a
7956 member template. */
7959 /* Fall through. */
7962 {
7966 return
7970 }
7974 return
7978 access_path);
7981 {
7986 }
7993 }
7995 }
7996 \f
7997 /* Return the name of the virtual function pointer field
7998 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7999 this may have to look back through base types to find the
8000 ultimate field name. (For single inheritance, these could
8001 all be the same name. Who knows for multiple inheritance). */
8003 static tree
8005 {
8012 {
8018 }
8026 }
8028 void
8030 {
8037 {
8042 }
8043 }
8045 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
8046 according to [class]:
8047 The class-name is also inserted
8048 into the scope of the class itself. For purposes of access checking,
8049 the inserted class name is treated as if it were a public member name. */
8051 void
8053 {
8056 tree saved_cas;
8071 }
8073 /* Returns 1 if TYPE contains only padding bytes. */
8075 int
8077 {
8085 }
8087 /* Returns true if TYPE contains no actual data, just various
8088 possible combinations of empty classes and possibly a vptr. */
8090 bool
8092 {
8094 {
8095 tree field;
8096 tree binfo;
8097 tree base_binfo;
8100 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
8101 out, but we'd like to be able to check this before then. */
8115 }
8119 }
8121 /* Note that NAME was looked up while the current class was being
8122 defined and that the result of that lookup was DECL. */
8124 void
8126 {
8127 splay_tree names_used;
8129 /* If we're not defining a class, there's nothing to do. */
8135 /* If there's already a binding for this NAME, then we don't have
8136 anything to worry about. */
8149 }
8151 /* Note that NAME was declared (as DECL) in the current class. Check
8152 to see that the declaration is valid. */
8154 void
8156 {
8157 splay_tree names_used;
8158 splay_tree_node n;
8160 /* Look to see if we ever used this name. */
8161 names_used
8165 /* The C language allows members to be declared with a type of the same
8166 name, and the C++ standard says this diagnostic is not required. So
8167 allow it in extern "C" blocks unless predantic is specified.
8168 Allow it in all cases if -ms-extensions is specified. */
8174 {
8175 /* [basic.scope.class]
8177 A name N used in a class S shall refer to the same declaration
8178 in its context and when re-evaluated in the completed scope of
8179 S. */
8184 }
8185 }
8187 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
8188 Secondary vtables are merged with primary vtables; this function
8189 will return the VAR_DECL for the primary vtable. */
8191 tree
8193 {
8194 tree decl;
8198 {
8201 }
8205 }
8208 /* Returns the binfo for the primary base of BINFO. If the resulting
8209 BINFO is a virtual base, and it is inherited elsewhere in the
8210 hierarchy, then the returned binfo might not be the primary base of
8211 BINFO in the complete object. Check BINFO_PRIMARY_P or
8212 BINFO_LOST_PRIMARY_P to be sure. */
8214 static tree
8216 {
8217 tree primary_base;
8224 }
8226 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
8228 static int
8230 {
8234 }
8236 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
8237 INDENT should be zero when called from the top level; it is
8238 incremented recursively. IGO indicates the next expected BINFO in
8239 inheritance graph ordering. */
8241 static tree
8244 tree binfo,
8245 tree igo,
8247 {
8249 tree base_binfo;
8257 {
8260 }
8275 {
8279 TFF_PLAIN_IDENTIFIER),
8281 }
8283 {
8286 }
8291 {
8295 {
8299 TFF_PLAIN_IDENTIFIER));
8300 }
8302 {
8306 TFF_PLAIN_IDENTIFIER));
8307 }
8309 {
8313 TFF_PLAIN_IDENTIFIER));
8314 }
8316 {
8320 TFF_PLAIN_IDENTIFIER));
8321 }
8325 }
8331 }
8333 /* Dump the BINFO hierarchy for T. */
8335 static void
8337 {
8349 }
8351 /* Debug interface to hierarchy dumping. */
8353 void
8355 {
8357 }
8359 static void
8361 {
8366 {
8368 }
8369 }
8371 static void
8373 {
8374 tree value;
8376 HOST_WIDE_INT elt;
8384 TFF_PLAIN_IDENTIFIER));
8391 }
8393 static void
8395 {
8403 {
8410 {
8415 }
8419 }
8420 }
8422 static void
8424 {
8432 {
8437 }
8438 }
8440 /* Dump a function or thunk and its thunkees. */
8442 static void
8444 {
8447 tree thunks;
8455 {
8465 else
8471 }
8475 }
8477 /* Dump the thunks for FN. */
8479 void
8481 {
8483 }
8485 /* Virtual function table initialization. */
8487 /* Create all the necessary vtables for T and its base classes. */
8489 static void
8491 {
8492 tree vbase;
8496 /* We lay out the primary and secondary vtables in one contiguous
8497 vtable. The primary vtable is first, followed by the non-virtual
8498 secondary vtables in inheritance graph order. */
8502 /* Then come the virtual bases, also in inheritance graph order. */
8504 {
8508 }
8512 }
8514 /* Initialize the vtable for BINFO with the INITS. */
8516 static void
8518 {
8519 tree decl;
8525 }
8527 /* Build the VTT (virtual table table) for T.
8528 A class requires a VTT if it has virtual bases.
8530 This holds
8531 1 - primary virtual pointer for complete object T
8532 2 - secondary VTTs for each direct non-virtual base of T which requires a
8533 VTT
8534 3 - secondary virtual pointers for each direct or indirect base of T which
8535 has virtual bases or is reachable via a virtual path from T.
8536 4 - secondary VTTs for each direct or indirect virtual base of T.
8538 Secondary VTTs look like complete object VTTs without part 4. */
8540 static void
8542 {
8543 tree type;
8544 tree vtt;
8545 tree index;
8548 /* Build up the initializers for the VTT. */
8553 /* If we didn't need a VTT, we're done. */
8557 /* Figure out the type of the VTT. */
8561 /* Now, build the VTT object itself. */
8564 /* Add the VTT to the vtables list. */
8569 }
8571 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8572 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8573 and CHAIN the vtable pointer for this binfo after construction is
8574 complete. VALUE can also be another BINFO, in which case we recurse. */
8576 static tree
8578 {
8579 tree vt;
8582 {
8588 else
8590 }
8593 }
8595 /* Data for secondary VTT initialization. */
8596 struct secondary_vptr_vtt_init_data
8597 {
8598 /* Is this the primary VTT? */
8601 /* Current index into the VTT. */
8602 tree index;
8604 /* Vector of initializers built up. */
8607 /* The type being constructed by this secondary VTT. */
8608 tree type_being_constructed;
8609 };
8611 /* Recursively build the VTT-initializer for BINFO (which is in the
8612 hierarchy dominated by T). INITS points to the end of the initializer
8613 list to date. INDEX is the VTT index where the next element will be
8614 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8615 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8616 for virtual bases of T. When it is not so, we build the constructor
8617 vtables for the BINFO-in-T variant. */
8619 static void
8622 {
8624 tree b;
8625 tree init;
8626 secondary_vptr_vtt_init_data data;
8629 /* We only need VTTs for subobjects with virtual bases. */
8633 /* We need to use a construction vtable if this is not the primary
8634 VTT. */
8636 {
8639 /* Record the offset in the VTT where this sub-VTT can be found. */
8641 }
8643 /* Add the address of the primary vtable for the complete object. */
8647 {
8650 }
8653 /* Recursively add the secondary VTTs for non-virtual bases. */
8658 /* Add secondary virtual pointers for all subobjects of BINFO with
8659 either virtual bases or reachable along a virtual path, except
8660 subobjects that are non-virtual primary bases. */
8670 /* data.inits might have grown as we added secondary virtual pointers.
8671 Make sure our caller knows about the new vector. */
8675 /* Add the secondary VTTs for virtual bases in inheritance graph
8676 order. */
8678 {
8683 }
8684 else
8685 /* Remove the ctor vtables we created. */
8687 }
8689 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8690 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8692 static tree
8694 {
8697 /* We don't care about bases that don't have vtables. */
8701 /* We're only interested in proper subobjects of the type being
8702 constructed. */
8706 /* We're only interested in bases with virtual bases or reachable
8707 via a virtual path from the type being constructed. */
8712 /* We're not interested in non-virtual primary bases. */
8716 /* Record the index where this secondary vptr can be found. */
8718 {
8723 {
8724 /* It's a primary virtual base, and this is not a
8725 construction vtable. Find the base this is primary of in
8726 the inheritance graph, and use that base's vtable
8727 now. */
8730 }
8731 }
8733 /* Add the initializer for the secondary vptr itself. */
8736 /* Advance the vtt index. */
8741 }
8743 /* Called from build_vtt_inits via dfs_walk. After building
8744 constructor vtables and generating the sub-vtt from them, we need
8745 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8746 binfo of the base whose sub vtt was generated. */
8748 static tree
8750 {
8754 /* If this class has no vtable, none of its bases do. */
8758 /* This might be a primary base, so have no vtable in this
8759 hierarchy. */
8762 /* If we scribbled the construction vtable vptr into BINFO, clear it
8763 out now. */
8769 }
8771 /* Build the construction vtable group for BINFO which is in the
8772 hierarchy dominated by T. */
8774 static void
8776 {
8777 tree type;
8778 tree vtbl;
8779 tree id;
8780 tree vbase;
8783 /* See if we've already created this construction vtable group. */
8789 /* Build a version of VTBL (with the wrong type) for use in
8790 constructing the addresses of secondary vtables in the
8791 construction vtable group. */
8794 /* Don't export construction vtables from shared libraries. Even on
8795 targets that don't support hidden visibility, this tells
8796 can_refer_decl_in_current_unit_p not to assume that it's safe to
8797 access from a different compilation unit (bz 54314). */
8805 /* Add the vtables for each of our virtual bases using the vbase in T
8806 binfo. */
8808 vbase;
8810 {
8811 tree b;
8818 }
8820 /* Figure out the type of the construction vtable. */
8827 /* Initialize the construction vtable. */
8831 }
8833 /* Add the vtbl initializers for BINFO (and its bases other than
8834 non-virtual primaries) to the list of INITS. BINFO is in the
8835 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8836 the constructor the vtbl inits should be accumulated for. (If this
8837 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8838 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8839 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8840 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8841 but are not necessarily the same in terms of layout. */
8843 static void
8845 tree orig_binfo,
8846 tree rtti_binfo,
8847 tree vtbl,
8848 tree t,
8850 {
8852 tree base_binfo;
8857 /* If it doesn't have a vptr, we don't do anything. */
8861 /* If we're building a construction vtable, we're not interested in
8862 subobjects that don't require construction vtables. */
8868 /* Build the initializers for the BINFO-in-T vtable. */
8871 /* Walk the BINFO and its bases. We walk in preorder so that as we
8872 initialize each vtable we can figure out at what offset the
8873 secondary vtable lies from the primary vtable. We can't use
8874 dfs_walk here because we need to iterate through bases of BINFO
8875 and RTTI_BINFO simultaneously. */
8877 {
8878 /* Skip virtual bases. */
8884 inits);
8885 }
8886 }
8888 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8889 BINFO vtable to L. */
8891 static void
8893 tree orig_binfo,
8894 tree rtti_binfo,
8895 tree orig_vtbl,
8896 tree t,
8898 {
8905 {
8906 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8907 primary virtual base. If it is not the same primary in
8908 the hierarchy of T, we'll need to generate a ctor vtable
8909 for it, to place at its location in T. If it is the same
8910 primary, we still need a VTT entry for the vtable, but it
8911 should point to the ctor vtable for the base it is a
8912 primary for within the sub-hierarchy of RTTI_BINFO.
8914 There are three possible cases:
8916 1) We are in the same place.
8917 2) We are a primary base within a lost primary virtual base of
8918 RTTI_BINFO.
8919 3) We are primary to something not a base of RTTI_BINFO. */
8921 tree b;
8924 /* First, look through the bases we are primary to for RTTI_BINFO
8925 or a virtual base. */
8928 {
8933 }
8934 /* If we run out of primary links, keep looking down our
8935 inheritance chain; we might be an indirect primary. */
8939 found:
8941 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8942 base B and it is a base of RTTI_BINFO, this is case 2. In
8943 either case, we share our vtable with LAST, i.e. the
8944 derived-most base within B of which we are a primary. */
8947 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8948 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8949 binfo_ctor_vtable after everything's been set up. */
8952 /* Otherwise, this is case 3 and we get our own. */
8953 }
8960 {
8961 tree index;
8964 /* Add the initializer for this vtable. */
8968 /* Figure out the position to which the VPTR should point. */
8974 }
8977 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8978 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8979 straighten this out. */
8982 /* Throw away any unneeded intializers. */
8984 else
8985 /* For an ordinary vtable, set BINFO_VTABLE. */
8987 }
8991 /* Construct the initializer for BINFO's virtual function table. BINFO
8992 is part of the hierarchy dominated by T. If we're building a
8993 construction vtable, the ORIG_BINFO is the binfo we should use to
8994 find the actual function pointers to put in the vtable - but they
8995 can be overridden on the path to most-derived in the graph that
8996 ORIG_BINFO belongs. Otherwise,
8997 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8998 BINFO that should be indicated by the RTTI information in the
8999 vtable; it will be a base class of T, rather than T itself, if we
9000 are building a construction vtable.
9002 The value returned is a TREE_LIST suitable for wrapping in a
9003 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
9004 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
9005 number of non-function entries in the vtable.
9007 It might seem that this function should never be called with a
9008 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
9009 base is always subsumed by a derived class vtable. However, when
9010 we are building construction vtables, we do build vtables for
9011 primary bases; we need these while the primary base is being
9012 constructed. */
9014 static void
9016 tree orig_binfo,
9017 tree t,
9018 tree rtti_binfo,
9021 {
9022 tree v;
9023 vtbl_init_data vid;
9025 tree vbinfo;
9029 /* Initialize VID. */
9037 /* The first vbase or vcall offset is at index -3 in the vtable. */
9040 /* Add entries to the vtable for RTTI. */
9043 /* Create an array for keeping track of the functions we've
9044 processed. When we see multiple functions with the same
9045 signature, we share the vcall offsets. */
9047 /* Add the vcall and vbase offset entries. */
9050 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
9051 build_vbase_offset_vtbl_entries. */
9056 /* If the target requires padding between data entries, add that now. */
9058 {
9063 /* Move data entries into their new positions and add padding
9064 after the new positions. Iterate backwards so we don't
9065 overwrite entries that we would need to process later. */
9068 ix--)
9069 {
9077 {
9081 null_pointer_node);
9082 }
9083 }
9084 }
9089 /* The initializers for virtual functions were built up in reverse
9090 order. Straighten them out and add them to the running list in one
9091 step. */
9100 /* Go through all the ordinary virtual functions, building up
9101 initializers. */
9103 {
9104 tree delta;
9105 tree vcall_index;
9112 {
9116 {
9119 }
9121 }
9123 /* If the only definition of this function signature along our
9124 primary base chain is from a lost primary, this vtable slot will
9125 never be used, so just zero it out. This is important to avoid
9126 requiring extra thunks which cannot be generated with the function.
9128 We first check this in update_vtable_entry_for_fn, so we handle
9129 restored primary bases properly; we also need to do it here so we
9130 zero out unused slots in ctor vtables, rather than filling them
9131 with erroneous values (though harmless, apart from relocation
9132 costs). */
9137 {
9138 /* Pull the offset for `this', and the function to call, out of
9139 the list. */
9146 /* You can't call an abstract virtual function; it's abstract.
9147 So, we replace these functions with __pure_virtual. */
9149 {
9152 {
9154 abort_fndecl_addr
9158 }
9159 }
9160 /* Likewise for deleted virtuals. */
9162 {
9171 }
9172 else
9173 {
9175 {
9179 }
9180 /* Take the address of the function, considering it to be of an
9181 appropriate generic type. */
9185 /* Don't refer to a virtual destructor from a constructor
9186 vtable or a vtable for an abstract class, since destroying
9187 an object under construction is undefined behavior and we
9188 don't want it to be considered a candidate for speculative
9189 devirtualization. But do create the thunk for ABI
9190 compliance. */
9195 }
9196 }
9198 /* And add it to the chain of initializers. */
9200 {
9205 else
9207 {
9213 }
9214 }
9215 else
9217 }
9218 }
9220 /* Adds to vid->inits the initializers for the vbase and vcall
9221 offsets in BINFO, which is in the hierarchy dominated by T. */
9223 static void
9225 {
9226 tree b;
9228 /* If this is a derived class, we must first create entries
9229 corresponding to the primary base class. */
9234 /* Add the vbase entries for this base. */
9236 /* Add the vcall entries for this base. */
9238 }
9240 /* Returns the initializers for the vbase offset entries in the vtable
9241 for BINFO (which is part of the class hierarchy dominated by T), in
9242 reverse order. VBASE_OFFSET_INDEX gives the vtable index
9243 where the next vbase offset will go. */
9245 static void
9247 {
9248 tree vbase;
9249 tree t;
9250 tree non_primary_binfo;
9252 /* If there are no virtual baseclasses, then there is nothing to
9253 do. */
9259 /* We might be a primary base class. Go up the inheritance hierarchy
9260 until we find the most derived class of which we are a primary base:
9261 it is the offset of that which we need to use. */
9264 {
9265 tree b;
9267 /* If we have reached a virtual base, then it must be a primary
9268 base (possibly multi-level) of vid->binfo, or we wouldn't
9269 have called build_vcall_and_vbase_vtbl_entries for it. But it
9270 might be a lost primary, so just skip down to vid->binfo. */
9272 {
9275 }
9281 }
9283 /* Go through the virtual bases, adding the offsets. */
9285 vbase;
9287 {
9288 tree b;
9289 tree delta;
9294 /* Find the instance of this virtual base in the complete
9295 object. */
9298 /* If we've already got an offset for this virtual base, we
9299 don't need another one. */
9304 /* Figure out where we can find this vbase offset. */
9313 /* The vbase offset had better be the same. */
9316 /* The next vbase will come at a more negative offset. */
9320 /* The initializer is the delta from BINFO to this virtual base.
9321 The vbase offsets go in reverse inheritance-graph order, and
9322 we are walking in inheritance graph order so these end up in
9323 the right order. */
9330 }
9331 }
9333 /* Adds the initializers for the vcall offset entries in the vtable
9334 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
9335 to VID->INITS. */
9337 static void
9339 {
9340 /* We only need these entries if this base is a virtual base. We
9341 compute the indices -- but do not add to the vtable -- when
9342 building the main vtable for a class. */
9345 /* If BINFO is RTTI_BINFO, then (since BINFO does not
9346 correspond to VID->DERIVED), we are building a primary
9347 construction virtual table. Since this is a primary
9348 virtual table, we do not need the vcall offsets for
9349 BINFO. */
9351 {
9352 /* We need a vcall offset for each of the virtual functions in this
9353 vtable. For example:
9355 class A { virtual void f (); };
9356 class B1 : virtual public A { virtual void f (); };
9357 class B2 : virtual public A { virtual void f (); };
9358 class C: public B1, public B2 { virtual void f (); };
9360 A C object has a primary base of B1, which has a primary base of A. A
9361 C also has a secondary base of B2, which no longer has a primary base
9362 of A. So the B2-in-C construction vtable needs a secondary vtable for
9363 A, which will adjust the A* to a B2* to call f. We have no way of
9364 knowing what (or even whether) this offset will be when we define B2,
9365 so we store this "vcall offset" in the A sub-vtable and look it up in
9366 a "virtual thunk" for B2::f.
9368 We need entries for all the functions in our primary vtable and
9369 in our non-virtual bases' secondary vtables. */
9371 /* If we are just computing the vcall indices -- but do not need
9372 the actual entries -- not that. */
9375 /* Now, walk through the non-virtual bases, adding vcall offsets. */
9377 }
9378 }
9380 /* Build vcall offsets, starting with those for BINFO. */
9382 static void
9384 {
9386 tree primary_binfo;
9387 tree base_binfo;
9389 /* Don't walk into virtual bases -- except, of course, for the
9390 virtual base for which we are building vcall offsets. Any
9391 primary virtual base will have already had its offsets generated
9392 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9396 /* If BINFO has a primary base, process it first. */
9401 /* Add BINFO itself to the list. */
9404 /* Scan the non-primary bases of BINFO. */
9408 }
9410 /* Called from build_vcall_offset_vtbl_entries_r. */
9412 static void
9414 {
9415 /* Make entries for the rest of the virtuals. */
9416 tree orig_fn;
9418 /* The ABI requires that the methods be processed in declaration
9419 order. */
9421 orig_fn;
9425 }
9427 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9429 static void
9431 {
9433 tree vcall_offset;
9434 tree derived_entry;
9436 /* If there is already an entry for a function with the same
9437 signature as FN, then we do not need a second vcall offset.
9438 Check the list of functions already present in the derived
9439 class vtable. */
9441 {
9443 /* We only use one vcall offset for virtual destructors,
9444 even though there are two virtual table entries. */
9448 }
9450 /* If we are building these vcall offsets as part of building
9451 the vtable for the most derived class, remember the vcall
9452 offset. */
9454 {
9457 }
9459 /* The next vcall offset will be found at a more negative
9460 offset. */
9464 /* Keep track of this function. */
9468 {
9469 tree base;
9470 tree fn;
9472 /* Find the overriding function. */
9476 else
9477 {
9480 /* The vbase we're working on is a primary base of
9481 vid->binfo. But it might be a lost primary, so its
9482 BINFO_OFFSET might be wrong, so we just use the
9483 BINFO_OFFSET from vid->binfo. */
9489 vcall_offset);
9490 }
9491 /* Add the initializer to the vtable. */
9493 }
9494 }
9496 /* Return vtbl initializers for the RTTI entries corresponding to the
9497 BINFO's vtable. The RTTI entries should indicate the object given
9498 by VID->rtti_binfo. */
9500 static void
9502 {
9503 tree b;
9504 tree t;
9505 tree offset;
9506 tree decl;
9507 tree init;
9511 /* To find the complete object, we will first convert to our most
9512 primary base, and then add the offset in the vtbl to that value. */
9516 {
9517 tree primary_base;
9523 }
9527 /* The second entry is the address of the typeinfo object. */
9530 else
9533 /* Convert the declaration to a type that can be stored in the
9534 vtable. */
9538 /* Add the offset-to-top entry. It comes earlier in the vtable than
9539 the typeinfo entry. Convert the offset to look like a
9540 function pointer, so that we can put it in the vtable. */
9543 }
9545 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9546 accessibility. */
9548 bool
9550 {
9553 }
9555 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9557 bool
9559 {
9563 }
9565 /* CTX1 and CTX2 are declaration contexts. Return the innermost common
9566 class between them, if any. */
9568 tree
9570 {
9582 {
9585 }
9589 }