| blob | c5830297b931266099b00efc2958b454a55ed4c9 |
1 /* Handle initialization things in -*- C++ -*-
2 Copyright (C) 1987-2023 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/>. */
21 /* High-level class interface. */
55 /* We are about to generate some complex initialization code.
56 Conceptually, it is all a single expression. However, we may want
57 to include conditionals, loops, and other such statement-level
58 constructs. Therefore, we build the initialization code inside a
59 statement-expression. This function starts such an expression.
60 STMT_EXPR_P and COMPOUND_STMT_P are filled in by this function;
61 pass them back to finish_init_stmts when the expression is
62 complete. */
64 static bool
66 {
73 }
75 /* Finish out the statement-expression begun by the previous call to
76 begin_init_stmts. Returns the statement-expression itself. */
78 static tree
80 {
88 }
90 /* Constructors */
92 /* Called from initialize_vtbl_ptrs via dfs_walk. BINFO is the base
93 which we want to initialize the vtable pointer for, DATA is
94 TREE_LIST whose TREE_VALUE is the this ptr expression. */
96 static tree
98 {
103 {
107 tf_warning_or_error);
110 }
113 }
115 /* Initialize all the vtable pointers in the object pointed to by
116 ADDR. */
118 void
120 {
121 tree list;
122 tree type;
127 /* Walk through the hierarchy, initializing the vptr in each base
128 class. We do these in pre-order because we can't find the virtual
129 bases for a class until we've initialized the vtbl for that
130 class. */
132 }
134 /* Return an expression for the zero-initialization of an object with
135 type T. This expression will either be a constant (in the case
136 that T is a scalar), or a CONSTRUCTOR (in the case that T is an
137 aggregate), or NULL (in the case that T does not require
138 initialization). In either case, the value can be used as
139 DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
140 initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
141 is the number of elements in the array. If STATIC_STORAGE_P is
142 TRUE, initializers are only generated for entities for which
143 zero-initialization does not simply mean filling the storage with
144 zero bytes. FIELD_SIZE, if non-NULL, is the bit size of the field,
145 subfields with bit positions at or above that bit size shouldn't
146 be added. Note that this only works when the result is assigned
147 to a base COMPONENT_REF; if we only have a pointer to the base subobject,
148 expand_assignment will end up clearing the full size of TYPE. */
150 static tree
152 tree field_size)
153 {
156 /* [dcl.init]
158 To zero-initialize an object of type T means:
160 -- if T is a scalar type, the storage is set to the value of zero
161 converted to T.
163 -- if T is a non-union class type, the storage for each non-static
164 data member and each base-class subobject is zero-initialized.
166 -- if T is a union type, the storage for its first data member is
167 zero-initialized.
169 -- if T is an array type, the storage for each element is
170 zero-initialized.
172 -- if T is a reference type, no initialization is performed. */
177 ;
179 /* In order to save space, we do not explicitly build initializers
180 for items that do not need them. GCC's semantics are that
181 items with static storage duration that are not otherwise
182 initialized are initialized to zero. */
183 ;
191 {
195 /* Iterate over the fields, building initializations. */
197 {
203 /* For unions, only the first field is initialized. */
210 /* Don't add virtual bases for base classes if they are beyond
211 the size of the current field, that means it is present
212 somewhere else in the object. */
214 {
219 }
221 /* Don't add zero width bitfields. */
226 /* Note that for class types there will be FIELD_DECLs
227 corresponding to base classes as well. Thus, iterating
228 over TYPE_FIELDs will result in correct initialization of
229 all of the subobjects. */
231 {
232 tree new_field_size
239 static_storage_p,
240 new_field_size);
243 }
244 }
246 /* Build a constructor to contain the initializations. */
248 }
250 {
251 tree max_index;
254 /* Iterate over the array elements, building initializations. */
259 /* Treat flexible array members like [0] arrays. */
262 else
265 /* If we have an error_mark here, we should just return error mark
266 as we don't know the size of the array yet. */
271 /* A zero-sized array, which is accepted as an extension, will
272 have an upper bound of -1. */
274 {
275 constructor_elt ce;
277 /* If this is a one element array, we just use a regular init. */
280 else
282 max_index);
287 {
290 }
291 }
293 /* Build a constructor to contain the initializations. */
295 }
298 else
301 /* In all cases, the initializer is a constant. */
306 }
308 /* Return an expression for the zero-initialization of an object with
309 type T. This expression will either be a constant (in the case
310 that T is a scalar), or a CONSTRUCTOR (in the case that T is an
311 aggregate), or NULL (in the case that T does not require
312 initialization). In either case, the value can be used as
313 DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
314 initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
315 is the number of elements in the array. If STATIC_STORAGE_P is
316 TRUE, initializers are only generated for entities for which
317 zero-initialization does not simply mean filling the storage with
318 zero bytes. */
320 tree
322 {
324 }
326 /* Return a suitable initializer for value-initializing an object of type
327 TYPE, as described in [dcl.init]. */
329 tree
331 {
332 /* [dcl.init]
334 To value-initialize an object of type T means:
336 - if T is a class type (clause 9) with either no default constructor
337 (12.1) or a default constructor that is user-provided or deleted,
338 then the object is default-initialized;
340 - if T is a (possibly cv-qualified) class type without a user-provided
341 or deleted default constructor, then the object is zero-initialized
342 and the semantic constraints for default-initialization are checked,
343 and if T has a non-trivial default constructor, the object is
344 default-initialized;
346 - if T is an array type, then each element is value-initialized;
348 - otherwise, the object is zero-initialized.
350 A program that calls for default-initialization or
351 value-initialization of an entity of reference type is ill-formed. */
354 {
355 tree ctor
361 /* The AGGR_INIT_EXPR tweaking below breaks in templates. */
370 {
371 /* This is a class that needs constructing, but doesn't have
372 a user-provided constructor. So we need to zero-initialize
373 the object and then call the implicitly defined ctor.
374 This will be handled in simplify_aggr_init_expr. */
377 }
378 }
380 /* Discard any access checking during subobject initialization;
381 the checks are implied by the call to the ctor which we have
382 verified is OK (cpp0x/defaulted46.C). */
387 }
389 /* Like build_value_init, but don't call the constructor for TYPE. Used
390 for base initializers. */
392 tree
394 {
396 {
400 }
401 /* FIXME the class and array cases should just use digest_init once it is
402 SFINAE-enabled. */
404 {
409 {
410 tree field;
413 /* Iterate over the fields, building initializations. */
415 {
426 /* Ignore flexible array members for value initialization. */
435 /* Ignore unnamed zero-width bitfields. */
440 /* We could skip vfields and fields of types with
441 user-defined constructors, but I think that won't improve
442 performance at all; it should be simpler in general just
443 to zero out the entire object than try to only zero the
444 bits that actually need it. */
446 /* Note that for class types there will be FIELD_DECLs
447 corresponding to base classes as well. Thus, iterating
448 over TYPE_FIELDs will result in correct initialization of
449 all of the subobjects. */
458 /* We shouldn't have gotten here for anything that would need
459 non-trivial initialization, and gimplify_init_ctor_preeval
460 would need to be fixed to allow it. */
463 }
465 /* Build a constructor to contain the zero- initializations. */
467 }
468 }
470 {
473 /* Iterate over the array elements, building initializations. */
476 /* If we have an error_mark here, we should just return error mark
477 as we don't know the size of the array yet. */
479 {
482 type);
484 }
487 /* A zero-sized array, which is accepted as an extension, will
488 have an upper bound of -1. */
490 {
491 constructor_elt ce;
493 /* If this is a one element array, we just use a regular init. */
496 else
507 /* We shouldn't have gotten here for anything that would need
508 non-trivial initialization, and gimplify_init_ctor_preeval
509 would need to be fixed to allow it. */
512 }
514 /* Build a constructor to contain the initializations. */
516 }
518 {
522 }
524 {
528 }
531 }
533 /* Initialize current class with INIT, a TREE_LIST of arguments for
534 a target constructor. If TREE_LIST is void_type_node, an empty
535 initializer list was given. Return the target constructor. */
537 static tree
539 {
544 tf_warning_or_error);
547 {
550 LOOKUP_NORMAL
551 |LOOKUP_NONVIRTUAL
555 {
558 LOOKUP_NORMAL
559 |LOOKUP_NONVIRTUAL
563 }
567 }
569 }
571 /* Instantiate the default member initializer of MEMBER, if needed.
572 Only get_nsdmi should use the return value of this function. */
574 tree
576 {
579 /* tsubst_decl uses void_node to indicate an uninstantiated DMI. */
581 {
582 /* Clear any special tsubst flags; the result of NSDMI instantiation
583 should be independent of the substitution context. */
587 location_t expr_loc
591 /* Check recursive instantiation. */
593 {
598 }
599 else
600 {
601 cp_evaluated ev;
613 {
617 }
623 /* Do deferred instantiation of the NSDMI. */
636 {
639 }
643 }
644 }
647 }
649 /* Return the non-static data initializer for FIELD_DECL MEMBER. */
651 tree
653 {
660 {
662 {
667 }
669 }
672 {
675 }
676 else
677 {
678 /* Use a PLACEHOLDER_EXPR when we don't have a 'this' parameter to
679 refer to; constexpr evaluation knows what to do with it. */
682 }
684 /* Clear processing_template_decl for sake of break_out_target_exprs;
685 INIT is always non-templated. */
686 processing_template_decl_sentinel ptds;
688 /* Strip redundant TARGET_EXPR so we don't need to remap it, and
689 so the aggregate init code below will see a CONSTRUCTOR. */
695 /* In a constructor, this expresses the full initialization, prevent
696 perform_member_init from calling another constructor (58162). */
699 /* Now put it back so C++17 copy elision works. */
707 }
709 /* Diagnose the flexible array MEMBER if its INITializer is non-null
710 and return true if so. Otherwise return false. */
712 bool
714 {
722 /* Point at the flexible array member declaration if it's initialized
723 in-class, and at the ctor if it's initialized in a ctor member
724 initializer list. */
725 location_t loc;
727 || !current_function_decl
730 else
735 }
737 /* If INIT's value can come from a call to std::initializer_list<T>::begin,
738 return that function. Otherwise, NULL_TREE. */
740 static tree
742 {
748 {
756 }
763 }
765 /* If INIT initializing MEMBER is copying the address of the underlying array
766 of an initializer_list, warn. */
768 static void
770 {
780 /* Do not warn if the parameter is an lvalue reference to non-const. */
798 "initializing %qD from %qE does not extend the lifetime "
800 }
802 /* Data structure for find_uninit_fields_r, below. */
805 /* The set tracking the yet-uninitialized members. */
807 /* The data member we are currently initializing. It can be either
808 a type (initializing a base class/delegating constructors), or
809 a COMPONENT_REF. */
810 tree member;
811 };
813 /* walk_tree callback that warns about using uninitialized data in
814 a member-initializer-list. */
816 static tree
818 {
824 /* No need to look into types or unevaluated operands. */
826 {
829 }
832 {
833 /* We'd need data flow info to avoid false positives. */
837 /* We might see a MODIFY_EXPR in cases like S() : a((b = 42)), c(b) { }
838 where the initializer for 'a' surreptitiously initializes 'b'. Let's
839 not bother with these complicated scenarios in the front end. */
841 /* Don't attempt to handle statement-expressions, either. */
845 /* If we're just taking the address of an object, it doesn't matter
846 whether it's been initialized. */
852 }
854 /* We'd need data flow info to avoid false positives. */
857 /* Attempt to handle a simple a{b}, but no more. */
859 {
863 else
865 }
866 /* Warn about uninitialized 'this'. */
868 {
871 {
877 }
878 /* Functions (whether static or nonstatic member) may have side effects
879 and initialize other members; it's not the front end's job to try to
880 figure it out. But don't give up for constructors: we still want to
881 warn when initializing base classes:
883 struct D : public B {
884 int x;
885 D() : B(x) {}
886 };
888 so carry on to detect that 'x' is used uninitialized. */
891 }
893 /* If we find FIELD in the uninitialized set, we warn. */
895 {
899 /* We're initializing a reference member with itself. */
905 {
908 "reference %qD is not yet bound to a value when used "
914 }
915 }
919 give_up:
923 }
925 /* Wrapper around find_uninit_fields_r above. */
927 static void
929 {
931 {
934 }
935 }
937 /* Initialize MEMBER, a FIELD_DECL, with INIT, a TREE_LIST of
938 arguments. If TREE_LIST is void_type_node, an empty initializer
939 list was given; if NULL_TREE no initializer was given. UNINITIALIZED
940 is the hash set that tracks uninitialized fields. */
942 static void
944 {
945 tree decl;
948 /* Use the non-static data member initializer if there was no
949 mem-initializer for this field. */
956 /* Effective C++ rule 12 requires that all data members be
957 initialized. */
961 member);
963 /* Get an lvalue for the data member. */
967 tf_warning_or_error);
972 && init
975 {
977 /* Handle references. */
984 member);
985 else
987 }
990 {
993 }
996 {
997 /* A(): a{e} */
1000 tf_warning_or_error);
1001 /* We are trying to initialize an array from a ()-list. If we
1002 should attempt to do so, conjure up a CONSTRUCTOR. */
1004 /* P0960 is a C++20 feature. */
1009 tf_warning_or_error);
1010 /* If we're initializing a class from a ()-list, leave the TREE_LIST
1011 alone: we might call an appropriate constructor, or (in C++20)
1012 do aggregate-initialization. */
1013 }
1015 /* Assume we are initializing the member. */
1019 {
1020 /* mem() means value-initialization. */
1022 {
1026 }
1027 else
1028 {
1034 }
1035 }
1036 /* Deal with this here, as we will get confused if we try to call the
1037 assignment op for an anonymous union. This can happen in a
1038 synthesized copy constructor. */
1040 {
1042 {
1045 }
1046 }
1052 {
1053 /* With references and list-initialization, we need to deal with
1054 extending temporary lifetimes. 12.2p5: "A temporary bound to a
1055 reference member in a constructor’s ctor-initializer (12.6.2)
1056 persists until the constructor exits." */
1058 releasing_vec cleanups;
1060 {
1065 }
1070 /* Don't add trivial initialization of an empty base/field, as they
1071 might not be ordered the way the back-end expects. */
1073 /* A FIELD_DECL doesn't really have a suitable lifetime, but
1074 make_temporary_var_for_ref_to_temp will treat it as automatic and
1075 set_up_extended_ref_temp wants to use the decl in a warning. */
1084 }
1087 {
1089 {
1093 {
1095 {
1096 /* Initialize the array only if it's not a flexible
1097 array member (i.e., if it has an upper bound). */
1101 }
1102 }
1103 else
1105 }
1106 else
1107 {
1114 {
1115 /* TYPE_NEEDS_CONSTRUCTING can be set just because we have a
1116 vtable; still give this diagnostic. */
1117 auto_diagnostic_group d;
1122 }
1124 tf_warning_or_error));
1125 }
1126 }
1127 else
1128 {
1130 {
1131 tree core_type;
1132 /* member traversal: note it leaves init NULL */
1134 {
1135 auto_diagnostic_group d;
1140 }
1142 {
1143 auto_diagnostic_group d;
1148 }
1159 /* We left the member uninitialized. */
1161 }
1168 tf_warning_or_error));
1169 }
1172 /* This member is now initialized, remove it from the uninitialized
1173 set. */
1177 {
1178 tree expr;
1183 tf_warning_or_error);
1187 tf_warning_or_error);
1192 }
1193 }
1195 /* Returns a TREE_LIST containing (as the TREE_PURPOSE of each node) all
1196 the FIELD_DECLs on the TYPE_FIELDS list for T, in reverse order. */
1198 static tree
1200 {
1201 tree fields;
1203 /* Note whether or not T is a union. */
1208 {
1209 tree fieldtype;
1211 /* Skip CONST_DECLs for enumeration constants and so forth. */
1217 /* For an anonymous struct or union, we must recursively
1218 consider the fields of the anonymous type. They can be
1219 directly initialized from the constructor. */
1221 {
1222 /* Add this field itself. Synthesized copy constructors
1223 initialize the entire aggregate. */
1225 /* And now add the fields in the anonymous aggregate. */
1228 }
1229 /* Add this field. */
1232 }
1235 }
1237 /* Return the innermost aggregate scope for FIELD, whether that is
1238 the enclosing class or an anonymous aggregate within it. */
1240 static tree
1242 {
1245 else
1247 }
1249 /* The MEM_INITS are a TREE_LIST. The TREE_PURPOSE of each list gives
1250 a FIELD_DECL or BINFO in T that needs initialization. The
1251 TREE_VALUE gives the initializer, or list of initializer arguments.
1253 Return a TREE_LIST containing all of the initializations required
1254 for T, in the order in which they should be performed. The output
1255 list has the same format as the input. */
1257 static tree
1259 {
1260 tree init;
1262 tree sorted_inits;
1263 tree next_subobject;
1268 /* Build up a list of initializations. The TREE_PURPOSE of entry
1269 will be the subobject (a FIELD_DECL or BINFO) to initialize. The
1270 TREE_VALUE will be the constructor arguments, or NULL if no
1271 explicit initialization was provided. */
1274 /* Process the virtual bases. */
1279 /* Process the direct bases. */
1285 /* Process the non-static data members. */
1287 /* Reverse the entire list of initializations, so that they are in
1288 the order that they will actually be performed. */
1291 /* If the user presented the initializers in an order different from
1292 that in which they will actually occur, we issue a warning. Keep
1293 track of the next subobject which can be explicitly initialized
1294 without issuing a warning. */
1297 /* Go through the explicit initializers, filling in TREE_PURPOSE in
1298 the SORTED_INITS. */
1300 {
1301 tree subobject;
1302 tree subobject_init;
1306 /* If the explicit initializers are in sorted order, then
1307 SUBOBJECT will be NEXT_SUBOBJECT, or something following
1308 it. */
1310 subobject_init;
1315 /* Issue a warning if the explicit initializer order does not
1316 match that which will actually occur.
1317 ??? Are all these on the correct lines? */
1319 {
1324 else
1330 else
1334 }
1336 /* Look again, from the beginning of the list. */
1338 {
1342 }
1344 /* It is invalid to initialize the same subobject more than
1345 once. */
1347 {
1351 subobject);
1352 else
1355 subobject);
1356 }
1358 /* Record the initialization. */
1360 /* Carry over the dummy TREE_TYPE node containing the source location. */
1363 }
1365 /* [class.base.init]
1367 If a ctor-initializer specifies more than one mem-initializer for
1368 multiple members of the same union (including members of
1369 anonymous unions), the ctor-initializer is ill-formed.
1371 Here we also splice out uninitialized union members. */
1373 {
1377 {
1378 tree field;
1379 tree ctx;
1385 /* Skip base classes. */
1389 /* If this is an anonymous aggregate with no explicit initializer,
1390 splice it out. */
1394 /* See if this field is a member of a union, or a member of a
1395 structure contained in a union, etc. */
1398 /* If this field is not a member of a union, skip it. */
1403 /* If this union member has no explicit initializer and no NSDMI,
1404 splice it out. */
1407 else
1410 /* It's only an error if we have two initializers for the same
1411 union type. */
1413 {
1416 }
1418 /* See if LAST_FIELD and the field initialized by INIT are
1419 members of the same union (or the union itself). If so, there's
1420 a problem, unless they're actually members of the same structure
1421 which is itself a member of a union. For example, given:
1423 union { struct { int i; int j; }; };
1425 initializing both `i' and `j' makes sense. */
1426 ctx = common_enclosing_class
1432 {
1433 /* A mem-initializer hides an NSDMI. */
1438 else
1439 {
1442 ctx);
1444 }
1445 }
1449 next:
1452 splice:
1454 }
1455 }
1458 }
1460 /* Callback for cp_walk_tree to mark all PARM_DECLs in a tree as read. */
1462 static tree
1464 {
1469 }
1471 /* Initialize all bases and members of CURRENT_CLASS_TYPE. MEM_INITS
1472 is a TREE_LIST giving the explicit mem-initializer-list for the
1473 constructor. The TREE_PURPOSE of each entry is a subobject (a
1474 FIELD_DECL or a BINFO) of the CURRENT_CLASS_TYPE. The TREE_VALUE
1475 is a TREE_LIST giving the arguments to the constructor or
1476 void_type_node for an empty list of arguments. */
1478 void
1480 {
1483 /* We will already have issued an error message about the fact that
1484 the type is incomplete. */
1488 /* Keep a set holding fields that are not initialized. */
1491 /* Initially that is all of them. */
1503 {
1504 /* Delegating constructor. */
1509 }
1515 /* Sort the mem-initializers into the order in which the
1516 initializations should be performed. */
1521 /* Initialize base classes. */
1525 {
1529 /* We already have issued an error message. */
1533 /* Suppress access control when calling the inherited ctor. */
1535 && flag_new_inheriting_ctors
1541 {
1542 /* If these initializations are taking place in a copy constructor,
1543 the base class should probably be explicitly initialized if there
1544 is a user-defined constructor in the base class (other than the
1545 default constructor, which will be called anyway). */
1553 }
1555 /* Initialize the base. */
1557 {
1558 tree base_addr;
1564 arguments,
1565 flags,
1566 tf_warning_or_error);
1571 }
1573 /* C++14 DR1658 Means we do not have to construct vbases of
1574 abstract classes. */
1576 else
1577 /* When not constructing vbases of abstract classes, at least mark
1578 the arguments expressions as read to avoid
1579 -Wunused-but-set-parameter false positives. */
1584 }
1587 /* Initialize the vptrs. */
1590 /* Initialize the data members. */
1592 {
1593 /* If this initializer was explicitly provided, then the dummy TREE_TYPE
1594 node contains the source location. */
1599 uninitialized);
1602 }
1603 }
1605 /* Returns the address of the vtable (i.e., the value that should be
1606 assigned to the vptr) for BINFO. */
1608 tree
1610 {
1612 tree vtbl;
1615 /* If this is a virtual primary base, then the vtable we want to store
1616 is that for the base this is being used as the primary base of. We
1617 can't simply skip the initialization, because we may be expanding the
1618 inits of a subobject constructor where the virtual base layout
1619 can be different. */
1623 /* Figure out what vtable BINFO's vtable is based on, and mark it as
1624 used. */
1628 /* Now compute the address to use when initializing the vptr. */
1634 }
1636 /* This code sets up the virtual function tables appropriate for
1637 the pointer DECL. It is a one-ply initialization.
1639 BINFO is the exact type that DECL is supposed to be. In
1640 multiple inheritance, this might mean "C's A" if C : A, B. */
1642 static void
1644 {
1646 tree vtt_index;
1648 /* Compute the initializer for vptr. */
1651 /* We may get this vptr from a VTT, if this is a subobject
1652 constructor or subobject destructor. */
1655 {
1656 tree vtbl2;
1657 tree vtt_parm;
1659 /* Compute the value to use, when there's a VTT. */
1665 /* The actual initializer is the VTT value only in the subobject
1666 constructor. In maybe_clone_body we'll substitute NULL for
1667 the vtt_parm in the case of the non-subobject constructor. */
1669 }
1671 /* Compute the location of the vtpr. */
1676 /* Assign the vtable to the vptr. */
1680 }
1682 /* If an exception is thrown in a constructor, those base classes already
1683 constructed must be destroyed. This function creates the cleanup
1684 for BINFO, which has just been constructed. If FLAG is non-NULL,
1685 it is a DECL which is nonzero when this base needs to be
1686 destroyed. */
1688 static void
1690 {
1691 tree expr;
1696 /* Call the destructor. */
1698 base_dtor_identifier,
1699 NULL,
1700 binfo,
1702 tf_warning_or_error);
1714 }
1716 /* Construct the virtual base-class VBASE passing the ARGUMENTS to its
1717 constructor. */
1719 static void
1721 {
1722 tree inner_if_stmt;
1723 tree exp;
1724 tree flag;
1726 /* If there are virtual base classes with destructors, we need to
1727 emit cleanups to destroy them if an exception is thrown during
1728 the construction process. These exception regions (i.e., the
1729 period during which the cleanups must occur) begin from the time
1730 the construction is complete to the end of the function. If we
1731 create a conditional block in which to initialize the
1732 base-classes, then the cleanup region for the virtual base begins
1733 inside a block, and ends outside of that block. This situation
1734 confuses the sjlj exception-handling code. Therefore, we do not
1735 create a single conditional block, but one for each
1736 initialization. (That way the cleanup regions always begin
1737 in the outer block.) We trust the back end to figure out
1738 that the FLAG will not change across initializations, and
1739 avoid doing multiple tests. */
1744 /* Compute the location of the virtual base. If we're
1745 constructing virtual bases, then we must be the most derived
1746 class. Therefore, we don't have to look up the virtual base;
1747 we already know where it is. */
1756 }
1758 /* Find the context in which this FIELD can be initialized. */
1760 static tree
1762 {
1765 /* Anonymous union members can be initialized in the first enclosing
1766 non-anonymous union context. */
1770 }
1772 /* Function to give error message if member initialization specification
1773 is erroneous. FIELD is the member we decided to initialize.
1774 TYPE is the type for which the initialization is being performed.
1775 FIELD must be a member of TYPE.
1777 MEMBER_NAME is the name of the member. */
1779 static int
1781 {
1785 {
1787 member_name);
1789 }
1791 {
1794 field);
1796 }
1798 {
1802 }
1804 {
1806 member_name);
1808 }
1811 }
1813 /* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
1814 is a _TYPE node or TYPE_DECL which names a base for that type.
1815 Check the validity of NAME, and return either the base _TYPE, base
1816 binfo, or the FIELD_DECL of the member. If NAME is invalid, return
1817 NULL_TREE and issue a diagnostic.
1819 An old style unnamed direct single base construction is permitted,
1820 where NAME is NULL. */
1822 tree
1824 {
1825 tree basetype;
1826 tree field;
1832 {
1833 /* This is an obsolete unnamed base class initializer. The
1834 parser will already have warned about its use. */
1836 {
1839 current_class_type);
1842 basetype = BINFO_TYPE
1847 current_class_type);
1849 }
1850 }
1852 {
1855 }
1858 else
1862 {
1863 tree class_binfo;
1864 tree direct_binfo;
1865 tree virtual_binfo;
1876 /* Look for a direct base. */
1881 /* Look for a virtual base -- unless the direct base is itself
1882 virtual. */
1886 /* [class.base.init]
1888 If a mem-initializer-id is ambiguous because it designates
1889 both a direct non-virtual base class and an inherited virtual
1890 base class, the mem-initializer is ill-formed. */
1892 {
1894 basetype);
1896 }
1899 {
1903 else
1907 }
1910 }
1911 else
1912 {
1915 else
1920 }
1923 }
1925 /* This is like `expand_member_init', only it stores one aggregate
1926 value into another.
1928 INIT comes in two flavors: it is either a value which
1929 is to be stored in EXP, or it is a parameter list
1930 to go to a constructor, which will operate on EXP.
1931 If INIT is not a parameter list for a constructor, then set
1932 LOOKUP_ONLYCONVERTING.
1933 If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
1934 the initializer, if FLAGS is 0, then it is the (init) form.
1935 If `init' is a CONSTRUCTOR, then we emit a warning message,
1936 explaining that such initializations are invalid.
1938 If INIT resolves to a CALL_EXPR which happens to return
1939 something of the type we are looking for, then we know
1940 that we can safely use that call to perform the
1941 initialization.
1943 The virtual function table pointer cannot be set up here, because
1944 we do not really know its type.
1946 This never calls operator=().
1948 When initializing, nothing is CONST.
1950 A default copy constructor may have to be used to perform the
1951 initialization.
1953 A constructor or a conversion operator may have to be used to
1954 perform the initialization, but not both, as it would be ambiguous. */
1956 tree
1958 {
1959 tree stmt_expr;
1960 tree compound_stmt;
1970 location_t init_loc = (init
1978 {
1983 {
1989 {
1990 /* Wrap the initializer in a CONSTRUCTOR so that build_vec_init
1991 recognizes it as direct-initialization. */
1995 }
1996 }
1997 else
1998 {
1999 /* Must arrange to initialize each element of EXP
2000 from elements of INIT. */
2009 && (!from_array
2011 /* Can happen, eg, handling the compound-literals
2012 extension (ext/complit12.C). */
2014 {
2019 }
2020 }
2024 from_array,
2025 complain);
2029 /* Restore the type of init unless it was used directly. */
2033 }
2053 /* Just know that we've seen something for this node. */
2057 }
2059 static bool
2061 tsubst_flags_t complain)
2062 {
2065 /* It fails because there may not be a constructor which takes
2066 its own type as the first (or only parameter), but which does
2067 take other types via a conversion. So, if the thing initializing
2068 the expression is a unit element of type X, first try X(X&),
2069 followed by initialization by X. If neither of these work
2070 out, then look hard. */
2071 tree rval;
2074 /* If we have direct-initialization from an initializer list, pull
2075 it out of the TREE_LIST so the code below can see it. */
2078 {
2082 /* Only call reshape_init if it has not been called earlier
2083 by the callers. */
2086 }
2090 /* A brace-enclosed initializer for an aggregate. In C++0x this can
2091 happen for direct-initialization, too. */
2097 /* A CONSTRUCTOR of the target's type is a previously digested
2098 initializer, whether that happened just above or in
2099 cp_parser_late_parsing_nsdmi.
2101 A TARGET_EXPR with TARGET_EXPR_DIRECT_INIT_P or TARGET_EXPR_LIST_INIT_P
2102 set represents the whole initialization, so we shouldn't build up
2103 another ctor call. */
2110 {
2111 /* Early initialization via a TARGET_EXPR only works for
2112 complete objects. */
2119 }
2124 {
2125 /* Base subobjects should only get direct-initialization. */
2129 /* Do nothing. We hit this in two cases: Reference initialization,
2130 where we aren't initializing a real variable, so we don't want
2131 to run a new constructor; and catching an exception, where we
2132 have already built up the constructor call so we could wrap it
2134 else
2135 {
2140 }
2142 /* We need to protect the initialization of a catch parm with a
2143 call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
2144 around the TARGET_EXPR for the copy constructor. See
2145 initialize_handler_parm. */
2149 {
2150 /* Avoid voidify_wrapper_expr making a temporary. */
2153 }
2157 }
2162 {
2166 }
2167 else
2172 {
2173 /* Delegating constructor. */
2174 tree complete;
2175 tree base;
2178 /* Unshare the arguments for the second call. */
2179 releasing_vec parms2;
2181 {
2184 }
2187 complain);
2192 complain);
2197 }
2198 else
2199 {
2204 complain);
2207 }
2213 {
2216 {
2220 }
2221 }
2223 /* FIXME put back convert_to_void? */
2228 }
2230 /* This function is responsible for initializing EXP with INIT
2231 (if any). Returns true on success, false on failure.
2233 BINFO is the binfo of the type for who we are performing the
2234 initialization. For example, if W is a virtual base class of A and B,
2235 and C : A, B.
2236 If we are initializing B, then W must contain B's W vtable, whereas
2237 were we initializing C, W must contain C's W vtable.
2239 TRUE_EXP is nonzero if it is the true expression being initialized.
2240 In this case, it may be EXP, or may just contain EXP. The reason we
2241 need this is because if EXP is a base element of TRUE_EXP, we
2242 don't necessarily know by looking at EXP where its virtual
2243 baseclass fields should really be pointing. But we do know
2244 from TRUE_EXP. In constructors, we don't know anything about
2245 the value being initialized.
2247 FLAGS is just passed to `build_new_method_call'. See that function
2248 for its description. */
2250 static bool
2252 tsubst_flags_t complain)
2253 {
2259 /* Use a function returning the desired type to initialize EXP for us.
2260 If the function is a constructor, and its first argument is
2261 NULL_TREE, know that it was meant for us--just slide exp on
2262 in and expand the constructor. Constructors now come
2263 as TARGET_EXPRs. */
2267 {
2269 /* If store_init_value returns NULL_TREE, the INIT has been
2270 recorded as the DECL_INITIAL for EXP. That means there's
2271 nothing more we have to do. */
2277 }
2279 /* List-initialization from {} becomes value-initialization for non-aggregate
2280 classes with default constructors. Handle this here when we're
2281 initializing a base, so protected access works. */
2283 {
2290 }
2292 /* If an explicit -- but empty -- initializer list was present,
2293 that's value-initialization. */
2295 {
2296 /* If the type has data but no user-provided default ctor, we need to zero
2297 out the object. */
2300 {
2303 /* Don't clobber already initialized virtual bases. */
2306 field_size);
2309 }
2311 /* If we don't need to mess with the constructor at all,
2312 then we're done. */
2316 /* Otherwise fall through and call the constructor. */
2318 }
2320 /* We know that expand_default_init can handle everything we want
2321 at this point. */
2323 }
2325 /* Report an error if TYPE is not a user-defined, class type. If
2326 OR_ELSE is nonzero, give an error message. */
2328 int
2330 {
2335 {
2339 }
2341 }
2343 /* Returns true iff the initializer INIT represents copy-initialization
2344 (and therefore we must set LOOKUP_ONLYCONVERTING when processing it). */
2346 bool
2348 {
2354 }
2356 /* Build a reference to a member of an aggregate. This is not a C++
2357 `&', but really something which can have its address taken, and
2358 then act as a pointer to member, for example TYPE :: FIELD can have
2359 its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
2360 this expression is the operand of "&".
2362 @@ Prints out lousy diagnostics for operator <typename>
2363 @@ fields.
2365 @@ This function should be rewritten and placed in search.cc. */
2367 tree
2369 tsubst_flags_t complain)
2370 {
2371 tree decl;
2374 /* class templates can come in as TEMPLATE_DECLs here. */
2387 /* Callers should call mark_used before this point, except for functions. */
2393 {
2397 }
2399 /* Entities other than non-static members need no further
2400 processing. */
2407 {
2411 }
2413 /* Set up BASEBINFO for member lookup. */
2416 /* A lot of this logic is now handled in lookup_member. */
2418 {
2419 /* Go from the TREE_BASELINK to the member function info. */
2423 {
2424 /* Get rid of a potential OVERLOAD around it. */
2427 /* Unique functions are handled easily. */
2429 /* For non-static member of base class, we need a special rule
2430 for access checking [class.protected]:
2432 If the access is to form a pointer to member, the
2433 nested-name-specifier shall name the derived class
2434 (or any class derived from that class). */
2439 complain);
2440 else
2442 complain);
2448 }
2449 else
2451 }
2453 {
2454 /* We need additional test besides the one in
2455 check_accessibility_of_qualified_id in case it is
2456 a pointer to non-static member. */
2458 complain))
2460 }
2463 {
2464 /* If MEMBER is non-static, then the program has fallen afoul of
2465 [expr.prim]:
2467 An id-expression that denotes a non-static data member or
2468 non-static member function of a class can only be used:
2470 -- as part of a class member access (_expr.ref_) in which the
2471 object-expression refers to the member's class or a class
2472 derived from that class, or
2474 -- to form a pointer to member (_expr.unary.op_), or
2476 -- in the body of a non-static member function of that class or
2477 of a class derived from that class (_class.mfct.non-static_), or
2479 -- in a mem-initializer for a constructor for that class or for
2480 a class derived from that class (_class.base.init_). */
2482 {
2483 /* Build a representation of the qualified name suitable
2484 for use as the operand to "&" -- even though the "&" is
2485 not actually present. */
2487 /* In Microsoft mode, treat a non-static member function as if
2488 it were a pointer-to-member. */
2490 {
2493 }
2498 }
2500 {
2504 }
2506 }
2511 }
2513 /* If DECL is a scalar enumeration constant or variable with a
2514 constant initializer, return the initializer (or, its initializers,
2515 recursively); otherwise, return DECL. If STRICT_P, the
2516 initializer is only returned if DECL is a
2517 constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to
2518 return an aggregate constant. If UNSHARE_P, return an unshared
2519 copy of the initializer. */
2521 static tree
2524 {
2529 {
2530 tree init;
2531 /* If DECL is a static data member in a template
2532 specialization, we must instantiate it here. The
2533 initializer for the static data member is not processed
2534 until needed; we need it now. */
2538 {
2541 /* Treat the error as a constant to avoid cascading errors on
2542 excessively recursive template instantiation (c++/9335). */
2544 else
2546 }
2547 /* Initializers in templates are generally expanded during
2548 instantiation, so before that for const int i(2)
2549 INIT is a TREE_LIST with the actual initializer as
2550 TREE_VALUE. */
2552 && init
2556 /* Instantiate a non-dependent initializer for user variables. We
2557 mustn't do this for the temporary for an array compound literal;
2558 trying to instatiate the initializer will keep creating new
2559 temporaries until we crash. Probably it's not useful to do it for
2560 other artificial variables, either. */
2566 || (!return_aggregate_cst_ok_p
2567 /* Unless RETURN_AGGREGATE_CST_OK_P is true, do not
2568 return an aggregate constant (of which string
2569 literals are a special case), as we do not want
2570 to make inadvertent copies of such entities, and
2571 we must be sure that their addresses are the
2572 same everywhere. */
2576 /* Don't return a CONSTRUCTOR for a variable with partial run-time
2577 initialization, since it doesn't represent the entire value.
2578 Similarly for VECTOR_CSTs created by cp_folding those
2579 CONSTRUCTORs. */
2584 /* If the variable has a dynamic initializer, don't use its
2585 DECL_INITIAL which doesn't reflect the real value. */
2592 }
2594 }
2596 /* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by constant
2597 of integral or enumeration type, or a constexpr variable of scalar type,
2598 then return that value. These are those variables permitted in constant
2599 expressions by [5.19/1]. */
2601 tree
2603 {
2607 }
2609 /* Like scalar_constant_value, but can also return aggregate initializers.
2610 If UNSHARE_P, return an unshared copy of the initializer. */
2612 tree
2614 {
2618 }
2620 /* A more relaxed version of decl_really_constant_value, used by the
2621 common C/C++ code. */
2623 tree
2625 {
2629 }
2631 tree
2633 {
2635 }
2636 \f
2637 /* Common subroutines of build_new and build_vec_delete. */
2638 \f
2639 /* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
2640 the type of the object being allocated; otherwise, it's just TYPE.
2641 INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
2642 user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
2643 a vector of arguments to be provided as arguments to a placement
2644 new operator. This routine performs no semantic checks; it just
2645 creates and returns a NEW_EXPR. */
2647 static tree
2650 {
2651 tree init_list;
2652 tree new_expr;
2654 /* If INIT is NULL, the we want to store NULL_TREE in the NEW_EXPR.
2655 If INIT is not NULL, then we want to store VOID_ZERO_NODE. This
2656 permits us to distinguish the case of a missing initializer "new
2657 int" from an empty initializer "new int()". */
2662 else
2667 init_list);
2672 }
2674 /* Diagnose uninitialized const members or reference members of type
2675 TYPE. USING_NEW is used to disambiguate the diagnostic between a
2676 new expression without a new-initializer and a declaration. Returns
2677 the error count. */
2679 static int
2682 {
2683 tree field;
2690 {
2691 tree field_type;
2702 {
2705 {
2707 {
2711 else
2713 }
2714 else
2715 {
2720 else
2723 }
2726 }
2727 }
2730 {
2733 {
2735 {
2739 else
2741 }
2742 else
2743 {
2748 else
2751 }
2754 }
2755 }
2758 error_count
2761 }
2763 }
2765 int
2767 {
2769 }
2771 /* Call __cxa_bad_array_new_length to indicate that the size calculation
2772 overflowed. Pretend it returns sizetype so that it plays nicely in the
2773 COND_EXPR. */
2775 tree
2777 {
2779 {
2784 fn = push_throw_library_fn
2786 }
2789 }
2791 /* Attempt to verify that the argument, OPER, of a placement new expression
2792 refers to an object sufficiently large for an object of TYPE or an array
2793 of NELTS of such objects when NELTS is non-null, and issue a warning when
2794 it does not. SIZE specifies the size needed to construct the object or
2795 array and captures the result of NELTS * sizeof (TYPE). (SIZE could be
2796 greater when the array under construction requires a cookie to store
2797 NELTS. GCC's placement new expression stores the cookie when invoking
2798 a user-defined placement new operator function but not the default one.
2799 Placement new expressions with user-defined placement new operator are
2800 not diagnosed since we don't know how they use the buffer (this could
2801 be a future extension). */
2802 static void
2804 {
2809 /* Using a function argument or a (non-array) variable as an argument
2810 to placement new is not checked since it's unknown what it might
2811 point to. */
2817 /* Evaluate any constant expressions. */
2820 access_ref ref;
2827 /* We can only draw conclusions if ref.deref == -1,
2828 i.e. oper is the address of the object. */
2833 offset_int bytes_need;
2842 else
2843 {
2844 /* The type is a VLA. */
2846 }
2851 /* True when the size to mention in the warning is exact as opposed
2852 to "at least N". */
2863 (exact_size
2865 "of type %<%T [%wu]%> and size %qwu "
2868 "of type %<%T [%wu]%> and size %qwu "
2869 "in a region of type %qT and size "
2874 else
2876 (exact_size
2878 "of objects of type %qT and size %qwu "
2881 "of objects of type %qT and size %qwu "
2882 "in a region of type %qT and size "
2886 else
2888 (exact_size
2890 "of type %qT and size %qwu in a region "
2893 "of type %qT "
2894 "and size %qwu in a region of type %qT "
2903 /* Avoid mentioning the offset when its lower bound is zero
2904 or when it's impossibly large. */
2911 else
2915 }
2917 /* True if alignof(T) > __STDCPP_DEFAULT_NEW_ALIGNMENT__. */
2919 bool
2921 {
2924 }
2926 /* Return the alignment we expect malloc to guarantee. This should just be
2927 MALLOC_ABI_ALIGNMENT, but that macro defaults to only BITS_PER_WORD for some
2928 reason, so don't let the threshold be smaller than max_align_t_align. */
2930 unsigned
2932 {
2934 }
2936 /* Determine whether an allocation function is a namespace-scope
2937 non-replaceable placement new function. See DR 1748. */
2938 static bool
2940 {
2942 {
2947 }
2949 }
2951 /* For element type ELT_TYPE, return the appropriate type of the heap object
2952 containing such element(s). COOKIE_SIZE is the size of cookie in bytes.
2953 Return
2954 struct { size_t[COOKIE_SIZE/sizeof(size_t)]; ELT_TYPE[N]; }
2955 where N is nothing (flexible array member) if ITYPE2 is NULL, otherwise
2956 the array has ITYPE2 as its TYPE_DOMAIN. */
2958 tree
2960 {
2979 }
2981 /* Help the constexpr code to find the right type for the heap variable
2982 by adding a NOP_EXPR around ALLOC_CALL if needed for cookie_size.
2983 Return ALLOC_CALL or ALLOC_CALL cast to a pointer to
2984 struct { size_t[cookie_size/sizeof(size_t)]; elt_type[]; }. */
2986 static tree
2988 {
3007 NULL_TREE);
3009 }
3011 /* Generate code for a new-expression, including calling the "operator
3012 new" function, initializing the object, and, if an exception occurs
3013 during construction, cleaning up. The arguments are as for
3014 build_raw_new_expr. This may change PLACEMENT and INIT.
3015 TYPE is the type of the object being constructed, possibly an array
3016 of NELTS elements when NELTS is non-null (in "new T[NELTS]", T may
3017 be an array of the form U[inner], with the whole expression being
3018 "new U[NELTS][inner]"). */
3020 static tree
3023 tsubst_flags_t complain)
3024 {
3026 /* True iff this is a call to "operator new[]" instead of just
3027 "operator new". */
3029 /* If ARRAY_P is true, the element type of the array. This is never
3030 an ARRAY_TYPE; for something like "new int[3][4]", the
3031 ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
3032 TYPE. */
3033 tree elt_type;
3034 /* The type of the new-expression. (This type is always a pointer
3035 type.) */
3036 tree pointer_type;
3037 tree non_const_pointer_type;
3038 /* The most significant array bound in int[OUTER_NELTS][inner]. */
3040 /* For arrays with a non-constant number of elements, a bounds checks
3041 on the NELTS parameter to avoid integer overflow at runtime. */
3044 /* Number of the "inner" elements in "new T[OUTER_NELTS][inner]". */
3047 /* Size of the inner array elements (those with constant dimensions). */
3048 offset_int inner_size;
3049 /* The address returned by the call to "operator new". This node is
3050 a VAR_DECL and is therefore reusable. */
3051 tree alloc_node;
3052 tree alloc_fn;
3055 /* If non-NULL, the number of extra bytes to allocate at the
3056 beginning of the storage allocated for an array-new expression in
3057 order to store the number of elements. */
3059 tree placement_first;
3061 /* True if the function we are calling is a placement allocation
3062 function. */
3064 /* True if the storage must be initialized, either by a constructor
3065 or due to an explicit new-initializer. */
3067 /* The address of the thing allocated, not including any cookie. In
3068 particular, if an array cookie is in use, DATA_ADDR is the
3069 address of the first array element. This node is a VAR_DECL, and
3070 is therefore reusable. */
3071 tree data_addr;
3075 {
3078 }
3080 {
3081 /* Transforms new (T[N]) to new T[N]. The former is a GNU
3082 extension for variable N. (This also covers new T where T is
3083 a VLA typedef.) */
3089 }
3091 /* Lots of logic below depends on whether we have a constant number of
3092 elements, so go ahead and fold it now. */
3095 /* If our base type is an array, then make sure we know how many elements
3096 it has. */
3100 {
3104 {
3109 {
3113 }
3115 }
3116 else
3117 {
3119 {
3123 }
3125 }
3129 inner_nelts_cst,
3130 complain);
3131 }
3138 {
3141 }
3146 /* Warn if we performed the (T[N]) to T[N] transformation and N is
3147 variable. */
3150 {
3152 {
3159 }
3160 else
3162 }
3165 {
3169 }
3173 "%<new%> of %<initializer_list%> does not "
3182 {
3184 /* A program that calls for default-initialization [...] of an
3185 entity of reference type is ill-formed. */
3189 /* A new-expression that creates an object of type T initializes
3190 that object as follows:
3191 - If the new-initializer is omitted:
3192 -- If T is a (possibly cv-qualified) non-POD class type
3193 (or array thereof), the object is default-initialized (8.5).
3194 [...]
3195 -- Otherwise, the object created has indeterminate
3196 value. If T is a const-qualified type, or a (possibly
3197 cv-qualified) POD class type (or array thereof)
3198 containing (directly or indirectly) a member of
3199 const-qualified type, the program is ill-formed; */
3209 }
3213 {
3217 }
3221 {
3222 /* Maximum available size in bytes. Half of the address space
3223 minus the cookie size. */
3224 offset_int max_size
3226 /* Maximum number of outer elements which can be allocated. */
3227 offset_int max_outer_nelts;
3228 tree max_outer_nelts_tree;
3234 /* Unconditionally subtract the cookie size. This decreases the
3235 maximum object size and is safe even if we choose not to use
3236 a cookie after all. */
3242 {
3244 {
3245 cst_size_error error;
3248 else
3249 {
3253 inner_nelts_count));
3255 }
3258 }
3260 }
3268 {
3270 {
3271 /* When the array size is constant, check it at compile time
3272 to make sure it doesn't exceed the implementation-defined
3273 maximum, as required by C++ 14 (in C++ 11 this requirement
3274 isn't explicitly stated but it's enforced anyway -- see
3275 grokdeclarator in cp/decl.cc). */
3277 {
3281 }
3283 }
3284 }
3285 else
3286 {
3287 /* When a runtime check is necessary because the array size
3288 isn't constant, keep only the top-most seven bits (starting
3289 with the most significant non-zero bit) of the maximum size
3290 to compare the array size against, to simplify encoding the
3291 constant maximum size in the instruction stream. */
3298 outer_nelts,
3299 max_outer_nelts_tree);
3300 }
3301 }
3305 {
3307 /* Also consider the alignment of the cookie, if any. */
3311 }
3315 /* If PLACEMENT is a single simple pointer type not passed by
3316 reference, prepare to capture it in a temporary variable. Do
3317 this now, since PLACEMENT will change in the calls below. */
3325 /* Allocate the object. */
3326 tree fnname;
3327 tree fns;
3331 member_new_p = !globally_qualified_p
3333 && (array_p
3339 && (array_p
3344 {
3345 /* Use a class-specific operator new. */
3346 /* If a cookie is required, add some extra space. */
3349 else
3350 {
3352 /* No size arithmetic necessary, so the size check is
3353 not needed. */
3356 }
3357 /* Perform the overflow check. */
3364 /* Create the argument list. */
3366 /* Do name-lookup to find the appropriate operator. */
3369 {
3373 }
3375 {
3377 {
3380 }
3382 }
3386 {
3389 alloc_call
3393 /* If no matching function is found and the allocated object type
3394 has new-extended alignment, the alignment argument is removed
3395 from the argument list, and overload resolution is performed
3396 again. */
3399 }
3403 LOOKUP_NORMAL,
3405 }
3406 else
3407 {
3408 /* Use a global operator new. */
3409 /* See if a cookie might be required. */
3411 {
3413 /* No size arithmetic necessary, so the size check is
3414 not needed. */
3417 }
3419 /* If size is zero e.g. due to type having zero size, try to
3420 preserve outer_nelts for constant expression evaluation
3421 purposes. */
3429 }
3436 /* Now, check to see if this function is actually a placement
3437 allocation function. This can happen even when PLACEMENT is NULL
3438 because we might have something like:
3440 struct S { void* operator new (size_t, int i = 0); };
3442 A call to `new S' will get this allocation function, even though
3443 there is no explicit placement argument. If there is more than
3444 one argument, or there are variable arguments, then this is a
3445 placement allocation function. */
3446 placement_allocation_fn_p
3451 && warn_aligned_new
3452 && !placement_allocation_fn_p
3457 {
3458 auto_diagnostic_group d;
3461 {
3467 }
3468 }
3470 /* If we found a simple case of PLACEMENT_EXPR above, then copy it
3471 into a temporary variable. */
3477 {
3483 {
3487 }
3491 {
3492 /* Attempt to make the warning point at the operator new argument. */
3497 }
3498 }
3503 cookie_size);
3505 /* In the simple case, we can stop now. */
3510 /* Store the result of the allocation call in a variable so that we can
3511 use it more than once. */
3515 /* Strip any COMPOUND_EXPRs from ALLOC_CALL. */
3519 /* Preevaluate the placement args so that we don't reevaluate them for a
3520 placement delete. */
3522 {
3523 tree inits;
3527 alloc_expr);
3528 }
3530 /* unless an allocation function is declared with an empty excep-
3531 tion-specification (_except.spec_), throw(), it indicates failure to
3532 allocate storage by throwing a bad_alloc exception (clause _except_,
3533 _lib.bad.alloc_); it returns a non-null pointer otherwise If the allo-
3534 cation function is declared with an empty exception-specification,
3535 throw(), it returns null to indicate failure to allocate storage and a
3536 non-null pointer otherwise.
3538 So check for a null exception spec on the op new we just called. */
3541 check_new
3545 {
3546 tree cookie;
3547 tree cookie_ptr;
3548 tree size_ptr_type;
3550 /* Adjust so we're pointing to the start of the object. */
3553 /* Store the number of bytes allocated so that we can know how
3554 many elements to destroy later. We use the last sizeof
3555 (size_t) bytes to store the number of elements. */
3566 {
3567 /* Also store the element size. */
3578 }
3579 }
3580 else
3581 {
3584 }
3586 /* Now use a pointer to the type we've actually allocated. */
3588 /* But we want to operate on a non-const version to start with,
3589 since we'll be modifying the elements. */
3590 non_const_pointer_type = build_pointer_type
3594 /* Any further uses of alloc_node will want this type, too. */
3597 /* Now initialize the allocated object. Note that we preevaluate the
3598 initialization expression, apart from the actual constructor call or
3599 assignment--we do this because we want to delay the allocation as long
3600 as possible in order to minimize the size of the exception region for
3601 placement delete. */
3603 {
3607 {
3610 }
3613 {
3614 /* Avoid an ICE when converting to a base in build_simple_base_path.
3615 We'll throw this all away anyway, and build_new will create
3616 a NEW_EXPR. */
3618 /* build_value_init doesn't work in templates, and we don't need
3619 the initializer anyway since we're going to throw it away and
3620 rebuild it at instantiation time, so just build up a single
3621 constructor call to get any appropriate diagnostics. */
3625 complete_ctor_identifier,
3627 LOOKUP_NORMAL,
3628 complain);
3629 }
3631 {
3635 {
3639 else
3640 {
3644 complain);
3645 else
3646 /* We'll check the length at runtime. */
3649 /* If we have new char[4]{"foo"}, we have to reshape
3650 so that the STRING_CST isn't wrapped in { }. */
3652 /* The middle end doesn't cope with the location wrapper
3653 around a STRING_CST. */
3656 }
3657 }
3659 {
3663 }
3664 init_expr
3668 integer_one_node,
3669 complain),
3670 vecinit,
3671 explicit_value_init_p,
3673 complain);
3674 }
3675 else
3676 {
3680 {
3682 complete_ctor_identifier,
3684 LOOKUP_NORMAL,
3686 }
3688 {
3689 /* Something like `new int()'. NO_CLEANUP is needed so
3690 we don't try and build a (possibly ill-formed)
3691 destructor. */
3696 }
3697 else
3698 {
3699 tree ie;
3701 /* We are processing something like `new int (10)', which
3702 means allocate an int, and initialize it with 10.
3704 In C++20, also handle `new A(1, 2)'. */
3708 {
3713 }
3714 else
3716 complain);
3719 }
3720 /* If the initializer uses C++14 aggregate NSDMI that refer to the
3721 object being initialized, replace them now and don't try to
3722 preevaluate. */
3730 }
3734 }
3735 else
3738 /* If any part of the object initialization terminates by throwing an
3739 exception and a suitable deallocation function can be found, the
3740 deallocation function is called to free the memory in which the
3741 object was being constructed, after which the exception continues
3742 to propagate in the context of the new-expression. If no
3743 unambiguous matching deallocation function can be found,
3744 propagating the exception does not cause the object's memory to be
3745 freed. */
3747 {
3749 tree cleanup;
3751 /* The Standard is unclear here, but the right thing to do
3752 is to use the same method for finding deallocation
3753 functions that we use for finding allocation functions. */
3754 cleanup = (build_op_delete_call
3756 alloc_node,
3757 size,
3758 globally_qualified_p,
3760 alloc_fn,
3761 complain));
3764 /* Ack! First we allocate the memory. Then we set our sentry
3765 variable to true, and expand a cleanup that deletes the
3766 memory if sentry is true. Then we run the constructor, and
3767 finally clear the sentry.
3769 We need to do this because we allocate the space first, so
3770 if there are any temporaries with cleanups in the
3771 constructor args, we need this EH region to extend until
3772 end of full-expression to preserve nesting.
3774 We used to try to evaluate the args first to avoid this, but
3775 since C++17 [expr.new] says that "The invocation of the
3776 allocation function is sequenced before the evaluations of
3777 expressions in the new-initializer." */
3778 {
3786 /* CLEANUP is compiler-generated, so no diagnostics. */
3796 init_expr
3799 end));
3800 /* Likewise, this is compiler-generated. */
3802 }
3803 }
3805 /* Now build up the return value in reverse order. */
3817 /* If we don't have an initializer or a cookie, strip the TARGET_EXPR
3818 and return the call (which doesn't need to be adjusted). */
3820 else
3821 {
3823 {
3826 nullptr_node,
3827 complain);
3830 }
3832 /* Perform the allocation before anything else, so that ALLOC_NODE
3833 has been initialized before we start using it. */
3835 }
3837 /* A new-expression is never an lvalue. */
3841 }
3843 /* Generate a representation for a C++ "new" expression. *PLACEMENT
3844 is a vector of placement-new arguments (or NULL if none). If NELTS
3845 is NULL, TYPE is the type of the storage to be allocated. If NELTS
3846 is not NULL, then this is an array-new allocation; TYPE is the type
3847 of the elements in the array and NELTS is the number of elements in
3848 the array. *INIT, if non-NULL, is the initializer for the new
3849 object, or an empty vector to indicate an initializer of "()". If
3850 USE_GLOBAL_NEW is true, then the user explicitly wrote "::new"
3851 rather than just "new". This may change PLACEMENT and INIT. */
3853 tree
3856 tsubst_flags_t complain)
3857 {
3858 tree rval;
3867 /* Don't do auto deduction where it might affect mangling. */
3869 {
3872 {
3875 /* E.g. new auto(x) must have exactly one element, or
3876 a {} initializer will have one element. */
3878 {
3881 }
3882 /* For the rest, e.g. new A(1, 2, 3), create a list. */
3884 {
3886 tree t;
3889 {
3893 }
3894 }
3896 }
3897 }
3900 {
3907 use_global_new);
3912 {
3914 /* Also copy any CONSTRUCTORs in *init, since reshape_init and
3915 digest_init clobber them in place. */
3917 {
3921 }
3922 }
3928 }
3931 {
3934 {
3938 else
3940 }
3942 /* Try to determine the constant value only for the purposes
3943 of the diagnostic below but continue to use the original
3944 value and handle const folding later. */
3947 /* The expression in a noptr-new-declarator is erroneous if it's of
3948 non-class type and its value before converting to std::size_t is
3949 less than zero. ... If the expression is a constant expression,
3950 the program is ill-fomed. */
3958 }
3960 /* ``A reference cannot be created by the new operator. A reference
3961 is not an object (8.2.2, 8.4.3), so a pointer to it could not be
3962 returned by new.'' ARM 5.3.3 */
3964 {
3967 else
3970 }
3973 {
3977 }
3979 /* P1009: Array size deduction in new-expressions. */
3982 /* If ARRAY_P, we have to deduce the array bound. For C++20 paren-init,
3983 we have to process the parenthesized-list. But don't do it for (),
3984 which is value-initialization, and INIT should stay empty. */
3986 {
3987 /* This means we have 'new T[]()'. */
3989 {
3993 }
3995 /* The C++20 'new T[](e_0, ..., e_k)' case allowed by P0960. */
3997 {
4002 /* We've squashed all the vector elements into the first one;
4003 truncate the rest. */
4005 }
4006 /* Otherwise we should have 'new T[]{e_0, ..., e_k}'. */
4008 {
4009 /* We need to reshape before deducing the bounds to handle code like
4011 struct S { int x, y; };
4012 new S[]{1, 2, 3, 4};
4014 which should deduce S[2]. But don't change ELT itself: we want to
4015 pass a list-initializer to build_new_1, even for STRING_CSTs. */
4020 }
4021 }
4023 /* The type allocated must be complete. If the new-type-id was
4024 "T[N]" then we are just checking that "T" is complete here, but
4025 that is equivalent, since the value of "N" doesn't matter. */
4034 {
4040 }
4042 /* Wrap it in a NOP_EXPR so warn_if_unused_value doesn't complain. */
4047 }
4048 \f
4049 static tree
4051 special_function_kind auto_delete_vec,
4054 {
4055 tree virtual_size;
4057 tree size_exp;
4059 /* Temporary variables used by the loop. */
4062 /* This is the body of the loop that implements the deletion of a
4063 single element, and moves temp variables to next elements. */
4064 tree body;
4066 /* This is the LOOP_EXPR that governs the deletion of the elements. */
4069 /* This is the thing that governs what to do after the loop has run. */
4072 /* This is the BIND_EXPR which holds the outermost iterator of the
4073 loop. It is convenient to set this variable up and test it before
4074 executing any other code in the loop.
4075 This is also the containing expression returned by this function. */
4077 tree tmp;
4079 /* We should only have 1-D arrays here. */
4090 {
4092 {
4093 auto_diagnostic_group d;
4095 "possible problem detected in invocation of "
4097 {
4100 "class-specific operator %<delete []%> will be called, "
4102 }
4103 }
4104 /* This size won't actually be used. */
4107 }
4114 {
4115 /* Make sure the destructor is callable. */
4117 {
4123 }
4125 }
4127 /* The below is short by the cookie size. */
4134 virtual_size);
4149 /* [expr.delete]/3: "In an array delete expression, if the dynamic type of
4150 the object to be deleted is not similar to its static type, the behavior
4151 is undefined." So we can set LOOKUP_NONVIRTUAL. */
4161 /* If one destructor throws, keep trying to clean up the rest, unless we're
4162 already in a build_vec_init cleanup. */
4164 {
4167 /* Tell honor_protect_cleanup_actions to discard this on the
4168 exceptional path. */
4170 }
4174 no_destructor:
4175 /* Delete the storage if appropriate. */
4177 {
4178 tree base_tbd;
4180 /* The below is short by the cookie size. */
4185 /* no header */
4187 else
4188 {
4189 tree cookie_size;
4193 MINUS_EXPR,
4196 cookie_size,
4197 complain);
4201 /* True size with header. */
4203 }
4210 complain);
4211 }
4217 ;
4220 else
4221 /* The delete operator must be called, even if a destructor
4222 throws. */
4228 /* Outermost wrapper: If pointer is null, punt. */
4231 /* This is a compiler generated comparison, don't emit
4232 e.g. -Wnonnull-compare warning for it. */
4240 {
4243 }
4246 /* Pre-evaluate the SAVE_EXPR outside of the BIND_EXPR. */
4250 }
4252 /* Create an unnamed variable of the indicated TYPE. */
4254 tree
4256 {
4257 tree decl;
4267 }
4269 /* Create a new temporary variable of the indicated TYPE, initialized
4270 to INIT.
4272 It is not entered into current_binding_level, because that breaks
4273 things when it comes time to do final cleanups (which take place
4274 "outside" the binding contour of the function). */
4276 tree
4278 {
4279 tree decl;
4288 }
4290 /* Subroutine of build_vec_init. Returns true if assigning to an array of
4291 INNER_ELT_TYPE from INIT is trivial. */
4293 static bool
4295 {
4300 }
4302 /* Subroutine of build_vec_init: Check that the array has at least N
4303 elements. Other parameters are local variables in build_vec_init. */
4305 void
4307 {
4310 {
4312 {
4314 nelts);
4318 }
4319 /* Don't check an array new when -fno-exceptions. */
4320 }
4323 {
4324 /* Make sure the last element of the initializer is in bounds. */
4325 finish_expr_stmt
4326 (ubsan_instrument_bounds
4328 }
4329 }
4331 /* walk_tree callback to collect temporaries in an expression. */
4333 tree
4335 {
4345 }
4347 /* walk_tree callback to collect temporaries in an expression that
4348 are allocator arguments to standard library classes. */
4350 static tree
4352 {
4356 {
4359 }
4361 /* If this is a call to a constructor for a std:: class, look for
4362 a reference-to-allocator argument. */
4366 {
4369 {
4374 {
4377 {
4381 }
4382 }
4383 }
4384 }
4387 }
4389 /* If INIT initializes a standard library class, and involves a temporary
4390 std::allocator<T>, use ALLOC_OBJ for all such temporaries.
4392 Note that this can clobber the input to build_vec_init; no unsharing is
4393 done. To make this safe we use the TARGET_EXPR in all places rather than
4394 pulling out the TARGET_EXPR_SLOT.
4396 Used by build_vec_init when initializing an array of e.g. strings to reuse
4397 the same temporary allocator for all of the strings. We can do this because
4398 std::allocator has no data and the standard library doesn't care about the
4399 address of allocator objects.
4401 ??? Add an attribute to allow users to assert the same property for other
4402 classes, i.e. one object of the type is interchangeable with any other? */
4404 static void
4406 {
4410 {
4413 else
4415 }
4416 }
4418 /* `build_vec_init' returns tree structure that performs
4419 initialization of a vector of aggregate types.
4421 BASE is a reference to the vector, of ARRAY_TYPE, or a pointer
4422 to the first element, of POINTER_TYPE.
4423 MAXINDEX is the maximum index of the array (one less than the
4424 number of elements). It is only used if BASE is a pointer or
4425 TYPE_DOMAIN (TREE_TYPE (BASE)) == NULL_TREE.
4427 INIT is the (possibly NULL) initializer.
4429 If EXPLICIT_VALUE_INIT_P is true, then INIT must be NULL. All
4430 elements in the array are value-initialized.
4432 FROM_ARRAY is 0 if we should init everything with INIT
4433 (i.e., every element initialized from INIT).
4434 FROM_ARRAY is 1 if we should index into INIT in parallel
4435 with initialization of DECL.
4436 FROM_ARRAY is 2 if we should index into INIT in parallel,
4437 but use assignment instead of initialization. */
4439 tree
4443 tsubst_flags_t complain,
4445 {
4446 tree rval;
4449 tree iterator;
4450 /* The type of BASE. */
4452 /* The type of an element in the array. */
4454 /* The element type reached after removing all outer array
4455 types. */
4456 tree inner_elt_type;
4457 /* The type of a pointer to an element in the array. */
4458 tree ptype;
4459 tree stmt_expr;
4460 tree compound_stmt;
4482 /* Look through the TARGET_EXPR around a compound literal. */
4486 && (same_type_ignoring_top_level_qualifiers_p
4496 {
4500 {
4503 }
4504 }
4506 /* from_array doesn't apply to initialization from CONSTRUCTOR. */
4510 /* If we have a braced-init-list or string constant, make sure that the array
4511 is big enough for all the initializers. */
4527 || (same_type_ignoring_top_level_qualifiers_p
4529 /* Don't do this if the CONSTRUCTOR might contain something
4530 that might throw and require us to clean up. */
4534 {
4535 /* Do non-default initialization of trivial arrays resulting from
4536 brace-enclosed initializers. In this case, digest_init and
4537 store_constructor will handle the semantics for us. */
4543 }
4549 {
4555 }
4556 else
4560 {
4561 /* Shortcut zero element case to avoid unneeded constructor synthesis. */
4565 }
4567 /* The code we are generating looks like:
4568 ({
4569 T* t1 = (T*) base;
4570 T* rval = t1;
4571 ptrdiff_t iterator = maxindex;
4572 try {
4573 for (; iterator != -1; --iterator) {
4574 ... initialize *t1 ...
4575 ++t1;
4576 }
4577 } catch (...) {
4578 ... destroy elements that were constructed ...
4579 }
4580 rval;
4581 })
4583 We can omit the try and catch blocks if we know that the
4584 initialization will never throw an exception, or if the array
4585 elements do not have destructors. We can omit the loop completely if
4586 the elements of the array do not have constructors.
4588 We actually wrap the entire body of the above in a STMT_EXPR, for
4589 tidiness.
4591 When copying from array to another, when the array elements have
4592 only trivial copy constructors, we should use __builtin_memcpy
4593 rather than generating a loop. That way, we could take advantage
4594 of whatever cleverness the back end has for dealing with copies
4595 of blocks of memory. */
4606 /* If initializing one array from another, initialize element by
4607 element. We rely upon the below calls to do the argument
4608 checking. Evaluate the initializer before entering the try block. */
4610 {
4614 {
4615 /* Avoid error in decay_conversion. */
4618 }
4619 else
4626 }
4628 /* Protect the entire array initialization so that we can destroy
4629 the partially constructed array if an exception is thrown.
4630 But don't do this if we're assigning. */
4633 {
4634 tree e;
4637 complain);
4639 /* Flatten multi-dimensional array since build_vec_delete only
4640 expects one-dimensional array. */
4644 /* Avoid mixing signed and unsigned. */
4647 complain);
4658 /* Since we push this cleanup before doing any initialization, cleanups
4659 for any temporaries in the initialization are naturally within our
4660 cleanup region, so we don't want wrap_temporary_cleanups to do
4661 anything for arrays. But if the array is a subobject, we need to
4662 tell split_nonconstant_init how to turn off this cleanup in favor of
4663 the cleanup for the complete object. */
4666 }
4668 /* Should we try to create a constant initializer? */
4672 : (type_has_constexpr_default_constructor
4678 /* If we're initializing a static array, we want to do static
4679 initialization of any elements with constant initializers even if
4680 some are non-constant. */
4686 /* Skip over the handling of non-empty init lists. */
4689 /* Maybe pull out constant value when from_array? */
4692 {
4693 /* Do non-default initialization of non-trivial arrays resulting from
4694 brace-enclosed initializers. */
4697 /* If the constructor already has the array type, it's been through
4698 digest_init, so we shouldn't try to do anything more. */
4711 {
4713 tree one_init;
4715 num_initialized_elts++;
4717 /* We need to see sub-array TARGET_EXPR before cp_fold_r so we can
4718 handle cleanup flags properly. */
4725 cleanup_flags);
4728 else
4734 {
4739 {
4743 else
4745 }
4746 else
4747 {
4749 {
4754 }
4756 }
4757 }
4760 {
4761 /* Only create one std::allocator temporary. */
4764 }
4767 complain);
4770 else
4774 complain);
4777 else
4779 }
4781 /* Any elements without explicit initializers get T{}. */
4783 }
4785 {
4786 /* Check that the array is at least as long as the string. */
4793 /* Copy the string to the first part of the array. */
4799 /* Adjust the counter and pointer. */
4808 /* And set the rest of the array to NUL. */
4811 }
4813 {
4818 {
4822 }
4823 }
4825 /* Now, default-initialize any remaining elements. We don't need to
4826 do that if a) the type does not need constructing, or b) we've
4827 already initialized all the elements.
4829 We do need to keep going if we're copying an array. */
4834 /* With a constexpr default constructor, which we checked for when
4835 setting try_const above, default-initialization is equivalent to
4836 value-initialization, and build_value_init gives us something more
4837 friendly to maybe_constant_init. Except in C++20 and up a constexpr
4838 constructor need not initialize all the members. */
4843 && (num_initialized_elts
4845 {
4846 /* If the ITERATOR is lesser or equal to -1, then we don't have to loop;
4847 we've already initialized all the elements. */
4848 tree for_stmt;
4849 tree elt_init;
4850 tree to;
4857 /* We used to pass this decrement to finish_for_expr; now we add it to
4858 elt_init below so it's part of the same full-expression as the
4859 initialization, and thus happens before any potentially throwing
4860 temporary cleanups. */
4862 complain);
4867 /* If the initializer is {}, then all elements are initialized from T{}.
4868 But for non-classes, that's the same as value-initialization. */
4870 {
4872 {
4874 }
4875 else
4876 {
4879 }
4880 }
4883 {
4884 tree from;
4887 {
4893 }
4894 else
4907 complain);
4908 else
4910 }
4912 {
4914 {
4919 }
4920 else
4923 explicit_value_init_p,
4925 }
4927 {
4931 }
4932 else
4933 {
4937 else
4938 {
4941 complain);
4943 ? error_mark_node
4945 }
4946 }
4952 {
4953 /* FIXME refs to earlier elts */
4956 {
4958 /* Don't fill the CONSTRUCTOR with zeros. */
4962 }
4963 else
4964 {
4968 else
4970 }
4973 {
4976 {
4982 }
4983 }
4984 }
4986 /* [class.temporary]: "There are three contexts in which temporaries are
4987 destroyed at a different point than the end of the full-
4988 expression. The first context is when a default constructor is called
4989 to initialize an element of an array with no corresponding
4990 initializer. The second context is when a copy constructor is called
4991 to copy an element of an array while the entire array is copied. In
4992 either case, if the constructor has one or more default arguments, the
4993 destruction of every temporary created in a default argument is
4994 sequenced before the construction of the next array element, if any."
4996 So, for this loop, statements are full-expressions. */
5000 else
5006 complain));
5009 complain));
5012 }
5014 /* The value of the array initialization is the array itself, RVAL
5015 is a pointer to the first element. */
5026 {
5028 {
5031 }
5034 else
5036 }
5038 /* Now make the result have the correct type. */
5040 {
5044 }
5047 }
5049 /* Call the DTOR_KIND destructor for EXP. FLAGS are as for
5050 build_delete. */
5052 static tree
5054 tsubst_flags_t complain)
5055 {
5056 tree name;
5058 {
5073 }
5078 flags,
5079 complain);
5080 }
5082 /* Generate a call to a destructor. TYPE is the type to cast ADDR to.
5083 ADDR is an expression which yields the store to be destroyed.
5084 AUTO_DELETE is the name of the destructor to call, i.e., either
5085 sfk_complete_destructor, sfk_base_destructor, or
5086 sfk_deleting_destructor.
5088 FLAGS is the logical disjunction of zero or more LOOKUP_
5089 flags. See cp-tree.h for more info. */
5091 tree
5093 special_function_kind auto_delete,
5095 {
5096 tree expr;
5103 /* Can happen when CURRENT_EXCEPTION_OBJECT gets its type
5104 set to `error_mark_node' before it gets properly cleaned up. */
5112 {
5114 {
5118 }
5121 }
5127 {
5130 /* We don't want to warn about delete of void*, only other
5131 incomplete types. Deleting other incomplete types
5132 invokes undefined behavior, but it is not ill-formed, so
5133 compile to something that would even do The Right Thing
5134 (TM) should the type have a trivial dtor and no delete
5135 operator. */
5137 {
5145 {
5147 {
5148 auto_diagnostic_group d;
5150 "possible problem detected in invocation of "
5152 {
5155 "neither the destructor nor the class-specific "
5156 "%<operator delete%> will be called, even if "
5158 }
5159 }
5160 }
5164 {
5167 {
5170 "deleting object of abstract class type %qT"
5171 " which has non-virtual destructor"
5173 else
5175 "deleting object of polymorphic class type %qT"
5176 " which has non-virtual destructor"
5178 }
5179 }
5180 }
5182 /* Throw away const and volatile on target type of addr. */
5184 }
5185 else
5186 {
5187 /* Don't check PROTECT here; leave that decision to the
5188 destructor. If the destructor is accessible, call it,
5189 else report error. */
5195 }
5198 /* We will use ADDR multiple times so we must save it. */
5203 {
5207 }
5214 {
5215 /* Leave do_delete null. */
5216 }
5217 /* For `::delete x', we must not use the deleting destructor
5218 since then we would not be sure to get the global `operator
5219 delete'. */
5221 {
5223 /* Delete the object. */
5225 head,
5230 complain);
5231 /* Otherwise, treat this like a complete object destructor
5232 call. */
5234 }
5235 /* If the destructor is non-virtual, there is no deleting
5236 variant. Instead, we must explicitly call the appropriate
5237 `operator delete' here. */
5239 {
5240 /* Build the call. */
5242 addr,
5247 complain);
5248 /* Call the complete object destructor. */
5251 {
5254 }
5255 }
5257 {
5258 /* Make sure we have access to the member op delete, even though
5259 we'll actually be calling it from the destructor. */
5264 complain);
5265 }
5268 /* The operator delete will call the destructor. */
5273 else
5279 {
5282 }
5290 /* The delete operator must be called, regardless of whether
5291 the destructor throws.
5293 [expr.delete]/7 The deallocation function is called
5294 regardless of whether the destructor for the object or some
5295 element of the array throws an exception. */
5298 /* We need to calculate this before the dtor changes the vptr. */
5302 /* Handle deleting a null pointer. */
5310 /* This is a compiler generated comparison, don't emit
5311 e.g. -Wnonnull-compare warning for it. */
5320 }
5322 /* At the beginning of a destructor, push cleanups that will call the
5323 destructors for our base classes and members.
5325 Called from begin_destructor_body. */
5327 void
5329 {
5332 tree member;
5333 tree expr;
5336 /* Run destructors for all virtual baseclasses. */
5339 {
5340 tree cond = (condition_conversion
5342 current_in_charge_parm,
5343 integer_two_node)));
5345 /* The CLASSTYPE_VBASECLASSES vector is in initialization
5346 order, which is also the right order for pushing cleanups. */
5349 {
5351 {
5353 base_dtor_identifier,
5354 NULL,
5355 base_binfo,
5356 (LOOKUP_NORMAL
5358 tf_warning_or_error);
5360 {
5364 }
5365 }
5366 }
5367 }
5369 /* Take care of the remaining baseclasses. */
5372 {
5378 base_dtor_identifier,
5381 tf_warning_or_error);
5384 }
5386 /* Don't automatically destroy union members. */
5392 {
5401 {
5402 tree this_member = (build_class_member_access_expr
5406 tf_warning_or_error));
5408 sfk_complete_destructor,
5413 }
5414 }
5415 }
5417 /* Build a C++ vector delete expression.
5418 MAXINDEX is the number of elements to be deleted.
5419 ELT_SIZE is the nominal size of each element in the vector.
5420 BASE is the expression that should yield the store to be deleted.
5421 This function expands (or synthesizes) these calls itself.
5422 AUTO_DELETE_VEC says whether the container (vector) should be deallocated.
5424 This also calls delete for virtual baseclasses of elements of the vector.
5426 Update: MAXINDEX is no longer needed. The size can be extracted from the
5427 start of the vector for pointers, and from the type for arrays. We still
5428 use MAXINDEX for arrays because it happens to already have one of the
5429 values we'd have to extract. (We could use MAXINDEX with pointers to
5430 confirm the size, and trap if the numbers differ; not clear that it'd
5431 be worth bothering.) */
5433 tree
5435 special_function_kind auto_delete_vec,
5437 {
5438 tree type;
5439 tree rval;
5445 {
5446 /* Step back one from start of vector, and read dimension. */
5447 tree cookie_addr;
5452 {
5455 }
5460 cookie_addr);
5462 }
5464 {
5465 /* Get the total number of things in the array, maxindex is a
5466 bad name. */
5473 {
5476 }
5477 }
5478 else
5479 {
5484 }
5493 }