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1 /* Handle initialization things in C++.
2 Copyright (C) 1987-2016 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* High-level class interface. */
48 /* We are about to generate some complex initialization code.
49 Conceptually, it is all a single expression. However, we may want
50 to include conditionals, loops, and other such statement-level
51 constructs. Therefore, we build the initialization code inside a
52 statement-expression. This function starts such an expression.
53 STMT_EXPR_P and COMPOUND_STMT_P are filled in by this function;
54 pass them back to finish_init_stmts when the expression is
55 complete. */
57 static bool
59 {
66 }
68 /* Finish out the statement-expression begun by the previous call to
69 begin_init_stmts. Returns the statement-expression itself. */
71 static tree
73 {
81 }
83 /* Constructors */
85 /* Called from initialize_vtbl_ptrs via dfs_walk. BINFO is the base
86 which we want to initialize the vtable pointer for, DATA is
87 TREE_LIST whose TREE_VALUE is the this ptr expression. */
89 static tree
91 {
96 {
100 tf_warning_or_error);
103 }
106 }
108 /* Initialize all the vtable pointers in the object pointed to by
109 ADDR. */
111 void
113 {
114 tree list;
115 tree type;
120 /* Walk through the hierarchy, initializing the vptr in each base
121 class. We do these in pre-order because we can't find the virtual
122 bases for a class until we've initialized the vtbl for that
123 class. */
125 }
127 /* Return an expression for the zero-initialization of an object with
128 type T. This expression will either be a constant (in the case
129 that T is a scalar), or a CONSTRUCTOR (in the case that T is an
130 aggregate), or NULL (in the case that T does not require
131 initialization). In either case, the value can be used as
132 DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
133 initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
134 is the number of elements in the array. If STATIC_STORAGE_P is
135 TRUE, initializers are only generated for entities for which
136 zero-initialization does not simply mean filling the storage with
137 zero bytes. FIELD_SIZE, if non-NULL, is the bit size of the field,
138 subfields with bit positions at or above that bit size shouldn't
139 be added. Note that this only works when the result is assigned
140 to a base COMPONENT_REF; if we only have a pointer to the base subobject,
141 expand_assignment will end up clearing the full size of TYPE. */
143 static tree
145 tree field_size)
146 {
149 /* [dcl.init]
151 To zero-initialize an object of type T means:
153 -- if T is a scalar type, the storage is set to the value of zero
154 converted to T.
156 -- if T is a non-union class type, the storage for each nonstatic
157 data member and each base-class subobject is zero-initialized.
159 -- if T is a union type, the storage for its first data member is
160 zero-initialized.
162 -- if T is an array type, the storage for each element is
163 zero-initialized.
165 -- if T is a reference type, no initialization is performed. */
170 ;
172 /* In order to save space, we do not explicitly build initializers
173 for items that do not need them. GCC's semantics are that
174 items with static storage duration that are not otherwise
175 initialized are initialized to zero. */
176 ;
182 {
183 tree field;
186 /* Iterate over the fields, building initializations. */
188 {
195 /* Don't add virtual bases for base classes if they are beyond
196 the size of the current field, that means it is present
197 somewhere else in the object. */
199 {
204 }
206 /* Note that for class types there will be FIELD_DECLs
207 corresponding to base classes as well. Thus, iterating
208 over TYPE_FIELDs will result in correct initialization of
209 all of the subobjects. */
211 {
212 tree new_field_size
219 static_storage_p,
220 new_field_size);
223 }
225 /* For unions, only the first field is initialized. */
228 }
230 /* Build a constructor to contain the initializations. */
232 }
234 {
235 tree max_index;
238 /* Iterate over the array elements, building initializations. */
243 else
246 /* If we have an error_mark here, we should just return error mark
247 as we don't know the size of the array yet. */
252 /* A zero-sized array, which is accepted as an extension, will
253 have an upper bound of -1. */
255 {
256 constructor_elt ce;
258 /* If this is a one element array, we just use a regular init. */
261 else
263 max_index);
269 {
272 }
273 }
275 /* Build a constructor to contain the initializations. */
277 }
280 else
283 /* In all cases, the initializer is a constant. */
288 }
290 /* Return an expression for the zero-initialization of an object with
291 type T. This expression will either be a constant (in the case
292 that T is a scalar), or a CONSTRUCTOR (in the case that T is an
293 aggregate), or NULL (in the case that T does not require
294 initialization). In either case, the value can be used as
295 DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
296 initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
297 is the number of elements in the array. If STATIC_STORAGE_P is
298 TRUE, initializers are only generated for entities for which
299 zero-initialization does not simply mean filling the storage with
300 zero bytes. */
302 tree
304 {
306 }
308 /* Return a suitable initializer for value-initializing an object of type
309 TYPE, as described in [dcl.init]. */
311 tree
313 {
314 /* [dcl.init]
316 To value-initialize an object of type T means:
318 - if T is a class type (clause 9) with either no default constructor
319 (12.1) or a default constructor that is user-provided or deleted,
320 then the object is default-initialized;
322 - if T is a (possibly cv-qualified) class type without a user-provided
323 or deleted default constructor, then the object is zero-initialized
324 and the semantic constraints for default-initialization are checked,
325 and if T has a non-trivial default constructor, the object is
326 default-initialized;
328 - if T is an array type, then each element is value-initialized;
330 - otherwise, the object is zero-initialized.
332 A program that calls for default-initialization or
333 value-initialization of an entity of reference type is ill-formed. */
335 /* The AGGR_INIT_EXPR tweaking below breaks in templates. */
341 {
342 tree ctor =
345 complain);
355 {
356 /* This is a class that needs constructing, but doesn't have
357 a user-provided constructor. So we need to zero-initialize
358 the object and then call the implicitly defined ctor.
359 This will be handled in simplify_aggr_init_expr. */
362 }
363 }
365 /* Discard any access checking during subobject initialization;
366 the checks are implied by the call to the ctor which we have
367 verified is OK (cpp0x/defaulted46.C). */
372 }
374 /* Like build_value_init, but don't call the constructor for TYPE. Used
375 for base initializers. */
377 tree
379 {
381 {
385 }
386 /* FIXME the class and array cases should just use digest_init once it is
387 SFINAE-enabled. */
389 {
394 {
395 tree field;
398 /* Iterate over the fields, building initializations. */
400 {
411 /* We could skip vfields and fields of types with
412 user-defined constructors, but I think that won't improve
413 performance at all; it should be simpler in general just
414 to zero out the entire object than try to only zero the
415 bits that actually need it. */
417 /* Note that for class types there will be FIELD_DECLs
418 corresponding to base classes as well. Thus, iterating
419 over TYPE_FIELDs will result in correct initialization of
420 all of the subobjects. */
429 /* We shouldn't have gotten here for anything that would need
430 non-trivial initialization, and gimplify_init_ctor_preeval
431 would need to be fixed to allow it. */
434 }
436 /* Build a constructor to contain the zero- initializations. */
438 }
439 }
441 {
444 /* Iterate over the array elements, building initializations. */
447 /* If we have an error_mark here, we should just return error mark
448 as we don't know the size of the array yet. */
450 {
453 type);
455 }
458 /* A zero-sized array, which is accepted as an extension, will
459 have an upper bound of -1. */
461 {
462 constructor_elt ce;
464 /* If this is a one element array, we just use a regular init. */
467 else
478 /* We shouldn't have gotten here for anything that would need
479 non-trivial initialization, and gimplify_init_ctor_preeval
480 would need to be fixed to allow it. */
483 }
485 /* Build a constructor to contain the initializations. */
487 }
489 {
493 }
495 {
499 }
502 }
504 /* Initialize current class with INIT, a TREE_LIST of
505 arguments for a target constructor. If TREE_LIST is void_type_node,
506 an empty initializer list was given. */
508 static void
510 {
516 tf_warning_or_error));
518 {
520 LOOKUP_NORMAL
521 |LOOKUP_NONVIRTUAL
527 }
528 }
530 /* Return the non-static data initializer for FIELD_DECL MEMBER. */
532 tree
534 {
535 tree init;
540 {
541 /* Use a PLACEHOLDER_EXPR when we don't have a 'this' parameter to
542 refer to; constexpr evaluation knows what to do with it. */
545 }
548 {
553 /* Check recursive instantiation. */
555 {
559 }
560 else
561 {
564 /* Do deferred instantiation of the NSDMI. */
565 init = (tsubst_copy_and_build
572 }
573 }
574 else
575 {
578 {
579 unparsed:
584 }
585 /* Strip redundant TARGET_EXPR so we don't need to remap it, and
586 so the aggregate init code below will see a CONSTRUCTOR. */
590 }
594 }
596 /* Initialize MEMBER, a FIELD_DECL, with INIT, a TREE_LIST of
597 arguments. If TREE_LIST is void_type_node, an empty initializer
598 list was given; if NULL_TREE no initializer was given. */
600 static void
602 {
603 tree decl;
606 /* Use the non-static data member initializer if there was no
607 mem-initializer for this field. */
614 /* Effective C++ rule 12 requires that all data members be
615 initialized. */
619 member);
621 /* Get an lvalue for the data member. */
625 tf_warning_or_error);
631 {
633 /* Handle references. */
640 member);
641 }
644 {
645 /* mem() means value-initialization. */
647 {
651 }
652 else
653 {
659 }
660 }
661 /* Deal with this here, as we will get confused if we try to call the
662 assignment op for an anonymous union. This can happen in a
663 synthesized copy constructor. */
665 {
667 {
670 }
671 }
674 /* Pre-digested NSDMI. */
677 /* { } mem-initializer. */
682 {
683 /* With references and list-initialization, we need to deal with
684 extending temporary lifetimes. 12.2p5: "A temporary bound to a
685 reference member in a constructor’s ctor-initializer (12.6.2)
686 persists until the constructor exits." */
691 tf_warning_or_error);
693 {
698 }
701 /* A FIELD_DECL doesn't really have a suitable lifetime, but
702 make_temporary_var_for_ref_to_temp will treat it as automatic and
703 set_up_extended_ref_temp wants to use the decl in a warning. */
713 }
716 {
718 {
720 {
723 else
727 }
731 {
733 {
734 /* Initialize the array only if it's not a flexible
735 array member (i.e., if it has an upper bound). */
739 }
740 }
741 else
743 }
744 else
745 {
752 {
753 /* TYPE_NEEDS_CONSTRUCTING can be set just because we have a
754 vtable; still give this diagnostic. */
759 }
761 tf_warning_or_error));
762 }
763 }
764 else
765 {
767 {
768 tree core_type;
769 /* member traversal: note it leaves init NULL */
771 {
776 }
778 {
783 }
793 }
795 /* There was an explicit member initialization. Do some work
796 in that case. */
798 tf_warning_or_error);
803 tf_warning_or_error));
804 }
807 {
808 tree expr;
813 tf_warning_or_error);
816 tf_warning_or_error);
821 }
822 }
824 /* Returns a TREE_LIST containing (as the TREE_PURPOSE of each node) all
825 the FIELD_DECLs on the TYPE_FIELDS list for T, in reverse order. */
827 static tree
829 {
830 tree fields;
832 /* Note whether or not T is a union. */
837 {
838 tree fieldtype;
840 /* Skip CONST_DECLs for enumeration constants and so forth. */
846 /* For an anonymous struct or union, we must recursively
847 consider the fields of the anonymous type. They can be
848 directly initialized from the constructor. */
850 {
851 /* Add this field itself. Synthesized copy constructors
852 initialize the entire aggregate. */
854 /* And now add the fields in the anonymous aggregate. */
857 }
858 /* Add this field. */
861 }
864 }
866 /* Return the innermost aggregate scope for FIELD, whether that is
867 the enclosing class or an anonymous aggregate within it. */
869 static tree
871 {
874 else
876 }
878 /* The MEM_INITS are a TREE_LIST. The TREE_PURPOSE of each list gives
879 a FIELD_DECL or BINFO in T that needs initialization. The
880 TREE_VALUE gives the initializer, or list of initializer arguments.
882 Return a TREE_LIST containing all of the initializations required
883 for T, in the order in which they should be performed. The output
884 list has the same format as the input. */
886 static tree
888 {
889 tree init;
891 tree sorted_inits;
892 tree next_subobject;
897 /* Build up a list of initializations. The TREE_PURPOSE of entry
898 will be the subobject (a FIELD_DECL or BINFO) to initialize. The
899 TREE_VALUE will be the constructor arguments, or NULL if no
900 explicit initialization was provided. */
903 /* Process the virtual bases. */
908 /* Process the direct bases. */
914 /* Process the non-static data members. */
916 /* Reverse the entire list of initializations, so that they are in
917 the order that they will actually be performed. */
920 /* If the user presented the initializers in an order different from
921 that in which they will actually occur, we issue a warning. Keep
922 track of the next subobject which can be explicitly initialized
923 without issuing a warning. */
926 /* Go through the explicit initializers, filling in TREE_PURPOSE in
927 the SORTED_INITS. */
929 {
930 tree subobject;
931 tree subobject_init;
935 /* If the explicit initializers are in sorted order, then
936 SUBOBJECT will be NEXT_SUBOBJECT, or something following
937 it. */
939 subobject_init;
944 /* Issue a warning if the explicit initializer order does not
945 match that which will actually occur.
946 ??? Are all these on the correct lines? */
948 {
953 else
959 else
963 }
965 /* Look again, from the beginning of the list. */
967 {
971 }
973 /* It is invalid to initialize the same subobject more than
974 once. */
976 {
980 subobject);
981 else
984 subobject);
985 }
987 /* Record the initialization. */
990 }
992 /* [class.base.init]
994 If a ctor-initializer specifies more than one mem-initializer for
995 multiple members of the same union (including members of
996 anonymous unions), the ctor-initializer is ill-formed.
998 Here we also splice out uninitialized union members. */
1000 {
1004 {
1005 tree field;
1006 tree ctx;
1012 /* Skip base classes. */
1016 /* If this is an anonymous aggregate with no explicit initializer,
1017 splice it out. */
1021 /* See if this field is a member of a union, or a member of a
1022 structure contained in a union, etc. */
1025 /* If this field is not a member of a union, skip it. */
1030 /* If this union member has no explicit initializer and no NSDMI,
1031 splice it out. */
1034 else
1037 /* It's only an error if we have two initializers for the same
1038 union type. */
1040 {
1043 }
1045 /* See if LAST_FIELD and the field initialized by INIT are
1046 members of the same union (or the union itself). If so, there's
1047 a problem, unless they're actually members of the same structure
1048 which is itself a member of a union. For example, given:
1050 union { struct { int i; int j; }; };
1052 initializing both `i' and `j' makes sense. */
1053 ctx = common_enclosing_class
1059 {
1060 /* A mem-initializer hides an NSDMI. */
1065 else
1066 {
1069 ctx);
1071 }
1072 }
1076 next:
1079 splice:
1082 }
1083 }
1086 }
1088 /* Initialize all bases and members of CURRENT_CLASS_TYPE. MEM_INITS
1089 is a TREE_LIST giving the explicit mem-initializer-list for the
1090 constructor. The TREE_PURPOSE of each entry is a subobject (a
1091 FIELD_DECL or a BINFO) of the CURRENT_CLASS_TYPE. The TREE_VALUE
1092 is a TREE_LIST giving the arguments to the constructor or
1093 void_type_node for an empty list of arguments. */
1095 void
1097 {
1100 /* We will already have issued an error message about the fact that
1101 the type is incomplete. */
1108 {
1109 /* Delegating constructor. */
1113 }
1119 /* Sort the mem-initializers into the order in which the
1120 initializations should be performed. */
1125 /* Initialize base classes. */
1129 {
1133 /* We already have issued an error message. */
1138 {
1139 /* If these initializations are taking place in a copy constructor,
1140 the base class should probably be explicitly initialized if there
1141 is a user-defined constructor in the base class (other than the
1142 default constructor, which will be called anyway). */
1150 }
1152 /* Initialize the base. */
1155 else
1156 {
1157 tree base_addr;
1163 tf_warning_or_error),
1164 arguments,
1165 flags,
1166 tf_warning_or_error);
1168 }
1169 }
1172 /* Initialize the vptrs. */
1175 /* Initialize the data members. */
1177 {
1181 }
1182 }
1184 /* Returns the address of the vtable (i.e., the value that should be
1185 assigned to the vptr) for BINFO. */
1187 tree
1189 {
1191 tree vtbl;
1194 /* If this is a virtual primary base, then the vtable we want to store
1195 is that for the base this is being used as the primary base of. We
1196 can't simply skip the initialization, because we may be expanding the
1197 inits of a subobject constructor where the virtual base layout
1198 can be different. */
1202 /* Figure out what vtable BINFO's vtable is based on, and mark it as
1203 used. */
1207 /* Now compute the address to use when initializing the vptr. */
1213 }
1215 /* This code sets up the virtual function tables appropriate for
1216 the pointer DECL. It is a one-ply initialization.
1218 BINFO is the exact type that DECL is supposed to be. In
1219 multiple inheritance, this might mean "C's A" if C : A, B. */
1221 static void
1223 {
1225 tree vtt_index;
1227 /* Compute the initializer for vptr. */
1230 /* We may get this vptr from a VTT, if this is a subobject
1231 constructor or subobject destructor. */
1234 {
1235 tree vtbl2;
1236 tree vtt_parm;
1238 /* Compute the value to use, when there's a VTT. */
1244 /* The actual initializer is the VTT value only in the subobject
1245 constructor. In maybe_clone_body we'll substitute NULL for
1246 the vtt_parm in the case of the non-subobject constructor. */
1248 }
1250 /* Compute the location of the vtpr. */
1252 tf_warning_or_error),
1256 /* Assign the vtable to the vptr. */
1260 }
1262 /* If an exception is thrown in a constructor, those base classes already
1263 constructed must be destroyed. This function creates the cleanup
1264 for BINFO, which has just been constructed. If FLAG is non-NULL,
1265 it is a DECL which is nonzero when this base needs to be
1266 destroyed. */
1268 static void
1270 {
1271 tree expr;
1276 /* Call the destructor. */
1278 base_dtor_identifier,
1279 NULL,
1280 binfo,
1282 tf_warning_or_error);
1294 }
1296 /* Construct the virtual base-class VBASE passing the ARGUMENTS to its
1297 constructor. */
1299 static void
1301 {
1302 tree inner_if_stmt;
1303 tree exp;
1304 tree flag;
1306 /* If there are virtual base classes with destructors, we need to
1307 emit cleanups to destroy them if an exception is thrown during
1308 the construction process. These exception regions (i.e., the
1309 period during which the cleanups must occur) begin from the time
1310 the construction is complete to the end of the function. If we
1311 create a conditional block in which to initialize the
1312 base-classes, then the cleanup region for the virtual base begins
1313 inside a block, and ends outside of that block. This situation
1314 confuses the sjlj exception-handling code. Therefore, we do not
1315 create a single conditional block, but one for each
1316 initialization. (That way the cleanup regions always begin
1317 in the outer block.) We trust the back end to figure out
1318 that the FLAG will not change across initializations, and
1319 avoid doing multiple tests. */
1324 /* Compute the location of the virtual base. If we're
1325 constructing virtual bases, then we must be the most derived
1326 class. Therefore, we don't have to look up the virtual base;
1327 we already know where it is. */
1336 }
1338 /* Find the context in which this FIELD can be initialized. */
1340 static tree
1342 {
1345 /* Anonymous union members can be initialized in the first enclosing
1346 non-anonymous union context. */
1350 }
1352 /* Function to give error message if member initialization specification
1353 is erroneous. FIELD is the member we decided to initialize.
1354 TYPE is the type for which the initialization is being performed.
1355 FIELD must be a member of TYPE.
1357 MEMBER_NAME is the name of the member. */
1359 static int
1361 {
1365 {
1367 member_name);
1369 }
1371 {
1374 field);
1376 }
1378 {
1382 }
1384 {
1386 member_name);
1388 }
1391 }
1393 /* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
1394 is a _TYPE node or TYPE_DECL which names a base for that type.
1395 Check the validity of NAME, and return either the base _TYPE, base
1396 binfo, or the FIELD_DECL of the member. If NAME is invalid, return
1397 NULL_TREE and issue a diagnostic.
1399 An old style unnamed direct single base construction is permitted,
1400 where NAME is NULL. */
1402 tree
1404 {
1405 tree basetype;
1406 tree field;
1412 {
1413 /* This is an obsolete unnamed base class initializer. The
1414 parser will already have warned about its use. */
1416 {
1419 current_class_type);
1422 basetype = BINFO_TYPE
1427 current_class_type);
1429 }
1430 }
1432 {
1435 }
1438 else
1442 {
1443 tree class_binfo;
1444 tree direct_binfo;
1445 tree virtual_binfo;
1456 /* Look for a direct base. */
1461 /* Look for a virtual base -- unless the direct base is itself
1462 virtual. */
1466 /* [class.base.init]
1468 If a mem-initializer-id is ambiguous because it designates
1469 both a direct non-virtual base class and an inherited virtual
1470 base class, the mem-initializer is ill-formed. */
1472 {
1474 basetype);
1476 }
1479 {
1483 else
1487 }
1490 }
1491 else
1492 {
1495 else
1500 }
1503 }
1505 /* This is like `expand_member_init', only it stores one aggregate
1506 value into another.
1508 INIT comes in two flavors: it is either a value which
1509 is to be stored in EXP, or it is a parameter list
1510 to go to a constructor, which will operate on EXP.
1511 If INIT is not a parameter list for a constructor, then set
1512 LOOKUP_ONLYCONVERTING.
1513 If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
1514 the initializer, if FLAGS is 0, then it is the (init) form.
1515 If `init' is a CONSTRUCTOR, then we emit a warning message,
1516 explaining that such initializations are invalid.
1518 If INIT resolves to a CALL_EXPR which happens to return
1519 something of the type we are looking for, then we know
1520 that we can safely use that call to perform the
1521 initialization.
1523 The virtual function table pointer cannot be set up here, because
1524 we do not really know its type.
1526 This never calls operator=().
1528 When initializing, nothing is CONST.
1530 A default copy constructor may have to be used to perform the
1531 initialization.
1533 A constructor or a conversion operator may have to be used to
1534 perform the initialization, but not both, as it would be ambiguous. */
1536 tree
1538 {
1539 tree stmt_expr;
1540 tree compound_stmt;
1561 {
1562 tree itype;
1564 /* An array may not be initialized use the parenthesized
1565 initialization form -- unless the initializer is "()". */
1567 {
1571 }
1572 /* Must arrange to initialize each element of EXP
1573 from elements of INIT. */
1583 complain);
1587 /* Restore the type of init unless it was used directly. */
1591 }
1595 /* Just know that we've seen something for this node. */
1609 }
1611 static void
1613 tsubst_flags_t complain)
1614 {
1616 tree ctor_name;
1618 /* It fails because there may not be a constructor which takes
1619 its own type as the first (or only parameter), but which does
1620 take other types via a conversion. So, if the thing initializing
1621 the expression is a unit element of type X, first try X(X&),
1622 followed by initialization by X. If neither of these work
1623 out, then look hard. */
1624 tree rval;
1627 /* If we have direct-initialization from an initializer list, pull
1628 it out of the TREE_LIST so the code below can see it. */
1631 {
1635 /* Only call reshape_init if it has not been called earlier
1636 by the callers. */
1639 }
1643 /* A brace-enclosed initializer for an aggregate. In C++0x this can
1644 happen for direct-initialization, too. */
1647 /* A CONSTRUCTOR of the target's type is a previously digested
1648 initializer, whether that happened just above or in
1649 cp_parser_late_parsing_nsdmi.
1651 A TARGET_EXPR with TARGET_EXPR_DIRECT_INIT_P or TARGET_EXPR_LIST_INIT_P
1652 set represents the whole initialization, so we shouldn't build up
1653 another ctor call. */
1660 {
1661 /* Early initialization via a TARGET_EXPR only works for
1662 complete objects. */
1669 }
1673 {
1674 /* Base subobjects should only get direct-initialization. */
1678 /* Do nothing. We hit this in two cases: Reference initialization,
1679 where we aren't initializing a real variable, so we don't want
1680 to run a new constructor; and catching an exception, where we
1681 have already built up the constructor call so we could wrap it
1683 else
1688 /* We need to protect the initialization of a catch parm with a
1689 call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
1690 around the TARGET_EXPR for the copy constructor. See
1691 initialize_handler_parm. */
1692 {
1696 }
1697 else
1702 }
1707 {
1711 }
1712 else
1717 {
1718 /* Delegating constructor. */
1719 tree complete;
1720 tree base;
1723 /* Unshare the arguments for the second call. */
1726 {
1729 }
1732 complain);
1738 complain);
1741 }
1742 else
1743 {
1746 else
1749 complain);
1750 }
1756 {
1759 {
1763 }
1764 }
1766 /* FIXME put back convert_to_void? */
1769 }
1771 /* This function is responsible for initializing EXP with INIT
1772 (if any).
1774 BINFO is the binfo of the type for who we are performing the
1775 initialization. For example, if W is a virtual base class of A and B,
1776 and C : A, B.
1777 If we are initializing B, then W must contain B's W vtable, whereas
1778 were we initializing C, W must contain C's W vtable.
1780 TRUE_EXP is nonzero if it is the true expression being initialized.
1781 In this case, it may be EXP, or may just contain EXP. The reason we
1782 need this is because if EXP is a base element of TRUE_EXP, we
1783 don't necessarily know by looking at EXP where its virtual
1784 baseclass fields should really be pointing. But we do know
1785 from TRUE_EXP. In constructors, we don't know anything about
1786 the value being initialized.
1788 FLAGS is just passed to `build_new_method_call'. See that function
1789 for its description. */
1791 static void
1793 tsubst_flags_t complain)
1794 {
1800 /* Use a function returning the desired type to initialize EXP for us.
1801 If the function is a constructor, and its first argument is
1802 NULL_TREE, know that it was meant for us--just slide exp on
1803 in and expand the constructor. Constructors now come
1804 as TARGET_EXPRs. */
1808 {
1810 /* If store_init_value returns NULL_TREE, the INIT has been
1811 recorded as the DECL_INITIAL for EXP. That means there's
1812 nothing more we have to do. */
1818 }
1820 /* If an explicit -- but empty -- initializer list was present,
1821 that's value-initialization. */
1823 {
1824 /* If the type has data but no user-provided ctor, we need to zero
1825 out the object. */
1828 {
1831 /* Don't clobber already initialized virtual bases. */
1834 field_size);
1837 }
1839 /* If we don't need to mess with the constructor at all,
1840 then we're done. */
1844 /* Otherwise fall through and call the constructor. */
1846 }
1848 /* We know that expand_default_init can handle everything we want
1849 at this point. */
1851 }
1853 /* Report an error if TYPE is not a user-defined, class type. If
1854 OR_ELSE is nonzero, give an error message. */
1856 int
1858 {
1863 {
1867 }
1869 }
1871 tree
1873 {
1879 else
1881 }
1883 /* Build a reference to a member of an aggregate. This is not a C++
1884 `&', but really something which can have its address taken, and
1885 then act as a pointer to member, for example TYPE :: FIELD can have
1886 its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
1887 this expression is the operand of "&".
1889 @@ Prints out lousy diagnostics for operator <typename>
1890 @@ fields.
1892 @@ This function should be rewritten and placed in search.c. */
1894 tree
1896 tsubst_flags_t complain)
1897 {
1898 tree decl;
1901 /* class templates can come in as TEMPLATE_DECLs here. */
1914 /* Callers should call mark_used before this point. */
1919 {
1923 }
1925 /* Entities other than non-static members need no further
1926 processing. */
1933 {
1937 }
1939 /* Set up BASEBINFO for member lookup. */
1942 /* A lot of this logic is now handled in lookup_member. */
1944 {
1945 /* Go from the TREE_BASELINK to the member function info. */
1949 {
1950 /* Get rid of a potential OVERLOAD around it. */
1953 /* Unique functions are handled easily. */
1955 /* For non-static member of base class, we need a special rule
1956 for access checking [class.protected]:
1958 If the access is to form a pointer to member, the
1959 nested-name-specifier shall name the derived class
1960 (or any class derived from that class). */
1964 complain);
1965 else
1967 complain);
1972 }
1973 else
1975 }
1977 /* We need additional test besides the one in
1978 check_accessibility_of_qualified_id in case it is
1979 a pointer to non-static member. */
1981 complain);
1984 {
1985 /* If MEMBER is non-static, then the program has fallen afoul of
1986 [expr.prim]:
1988 An id-expression that denotes a nonstatic data member or
1989 nonstatic member function of a class can only be used:
1991 -- as part of a class member access (_expr.ref_) in which the
1992 object-expression refers to the member's class or a class
1993 derived from that class, or
1995 -- to form a pointer to member (_expr.unary.op_), or
1997 -- in the body of a nonstatic member function of that class or
1998 of a class derived from that class (_class.mfct.nonstatic_), or
2000 -- in a mem-initializer for a constructor for that class or for
2001 a class derived from that class (_class.base.init_). */
2003 {
2004 /* Build a representation of the qualified name suitable
2005 for use as the operand to "&" -- even though the "&" is
2006 not actually present. */
2008 /* In Microsoft mode, treat a non-static member function as if
2009 it were a pointer-to-member. */
2011 {
2014 }
2019 }
2021 {
2025 }
2027 }
2032 }
2034 /* If DECL is a scalar enumeration constant or variable with a
2035 constant initializer, return the initializer (or, its initializers,
2036 recursively); otherwise, return DECL. If STRICT_P, the
2037 initializer is only returned if DECL is a
2038 constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to
2039 return an aggregate constant. */
2041 static tree
2043 {
2045 || (strict_p
2049 {
2050 tree init;
2051 /* If DECL is a static data member in a template
2052 specialization, we must instantiate it here. The
2053 initializer for the static data member is not processed
2054 until needed; we need it now. */
2059 {
2061 /* Treat the error as a constant to avoid cascading errors on
2062 excessively recursive template instantiation (c++/9335). */
2064 else
2066 }
2067 /* Initializers in templates are generally expanded during
2068 instantiation, so before that for const int i(2)
2069 INIT is a TREE_LIST with the actual initializer as
2070 TREE_VALUE. */
2072 && init
2076 /* Instantiate a non-dependent initializer. */
2081 || (!return_aggregate_cst_ok_p
2082 /* Unless RETURN_AGGREGATE_CST_OK_P is true, do not
2083 return an aggregate constant (of which string
2084 literals are a special case), as we do not want
2085 to make inadvertent copies of such entities, and
2086 we must be sure that their addresses are the
2087 same everywhere. */
2091 /* Don't return a CONSTRUCTOR for a variable with partial run-time
2092 initialization, since it doesn't represent the entire value. */
2097 }
2099 }
2101 /* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by constant
2102 of integral or enumeration type, or a constexpr variable of scalar type,
2103 then return that value. These are those variables permitted in constant
2104 expressions by [5.19/1]. */
2106 tree
2108 {
2111 }
2113 /* Like scalar_constant_value, but can also return aggregate initializers. */
2115 tree
2117 {
2120 }
2122 /* A more relaxed version of scalar_constant_value, used by the
2123 common C/C++ code. */
2125 tree
2127 {
2130 }
2131 \f
2132 /* Common subroutines of build_new and build_vec_delete. */
2133 \f
2134 /* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
2135 the type of the object being allocated; otherwise, it's just TYPE.
2136 INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
2137 user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
2138 a vector of arguments to be provided as arguments to a placement
2139 new operator. This routine performs no semantic checks; it just
2140 creates and returns a NEW_EXPR. */
2142 static tree
2145 {
2146 tree init_list;
2147 tree new_expr;
2149 /* If INIT is NULL, the we want to store NULL_TREE in the NEW_EXPR.
2150 If INIT is not NULL, then we want to store VOID_ZERO_NODE. This
2151 permits us to distinguish the case of a missing initializer "new
2152 int" from an empty initializer "new int()". */
2157 else
2162 init_list);
2167 }
2169 /* Diagnose uninitialized const members or reference members of type
2170 TYPE. USING_NEW is used to disambiguate the diagnostic between a
2171 new expression without a new-initializer and a declaration. Returns
2172 the error count. */
2174 static int
2177 {
2178 tree field;
2185 {
2186 tree field_type;
2197 {
2200 {
2202 {
2206 else
2208 }
2209 else
2210 {
2215 else
2218 }
2221 }
2222 }
2225 {
2228 {
2230 {
2234 else
2236 }
2237 else
2238 {
2243 else
2246 }
2249 }
2250 }
2253 error_count
2256 }
2258 }
2260 int
2262 {
2264 }
2266 /* Call __cxa_bad_array_new_length to indicate that the size calculation
2267 overflowed. Pretend it returns sizetype so that it plays nicely in the
2268 COND_EXPR. */
2270 tree
2272 {
2276 NULL_TREE));
2279 }
2281 /* Attempt to find the initializer for field T in the initializer INIT,
2282 when non-null. Returns the initializer when successful and NULL
2283 otherwise. */
2284 static tree
2286 {
2293 /* Iterate over all top-level initializer elements. */
2295 {
2296 /* If the member T is found, return it. */
2300 /* Otherwise continue and/or recurse into nested initializers. */
2304 }
2306 }
2308 /* Attempt to verify that the argument, OPER, of a placement new expression
2309 refers to an object sufficiently large for an object of TYPE or an array
2310 of NELTS of such objects when NELTS is non-null, and issue a warning when
2311 it does not. SIZE specifies the size needed to construct the object or
2312 array and captures the result of NELTS * sizeof (TYPE). (SIZE could be
2313 greater when the array under construction requires a cookie to store
2314 NELTS. GCC's placement new expression stores the cookie when invoking
2315 a user-defined placement new operator function but not the default one.
2316 Placement new expressions with user-defined placement new operator are
2317 not diagnosed since we don't know how they use the buffer (this could
2318 be a future extension). */
2319 static void
2321 {
2324 /* The number of bytes to add to or subtract from the size of the provided
2325 buffer based on an offset into an array or an array element reference.
2326 Although intermediate results may be negative (as in a[3] - 2) the final
2327 result cannot be. */
2329 /* True when the size of the entire destination object should be used
2330 to compute the possibly optimistic estimate of the available space. */
2332 /* True when the reference to the destination buffer is an ADDR_EXPR. */
2337 /* Using a function argument or a (non-array) variable as an argument
2338 to placement new is not checked since it's unknown what it might
2339 point to. */
2345 /* Evaluate any constant expressions. */
2348 /* Handle the common case of array + offset expression when the offset
2349 is a constant. */
2351 {
2352 /* If the offset is comple-time constant, use it to compute a more
2353 accurate estimate of the size of the buffer. Since the operand
2354 of POINTER_PLUS_EXPR is represented as an unsigned type, convert
2355 it to signed first.
2356 Otherwise, use the size of the entire array as an optimistic
2357 estimate (this may lead to false negatives). */
2361 else
2367 }
2372 {
2375 }
2381 {
2382 /* Similar to the offset computed above, see if the array index
2383 is a compile-time constant. If so, and unless the offset was
2384 not a compile-time constant, use the index to determine the
2385 size of the buffer. Otherwise, use the entire array as
2386 an optimistic estimate of the size. */
2390 else
2391 {
2394 }
2397 }
2399 /* Refers to the declared object that constains the subobject referenced
2400 by OPER. When the object is initialized, makes it possible to determine
2401 the actual size of a flexible array member used as the buffer passed
2402 as OPER to placement new. */
2404 /* True when operand is a COMPONENT_REF, to distinguish flexible array
2405 members from arrays of unspecified size. */
2408 /* Descend into a struct or union to find the member whose address
2409 is being used as the argument. */
2411 {
2417 }
2423 {
2424 /* A possibly optimistic estimate of the number of bytes available
2425 in the destination buffer. */
2427 /* True when the estimate above is in fact the exact size
2428 of the destination buffer rather than an estimate. */
2431 /* Treat members of unions and members of structs uniformly, even
2432 though the size of a member of a union may be viewed as extending
2433 to the end of the union itself (it is by __builtin_object_size). */
2437 {
2438 /* Use the size of the entire array object when the expression
2439 refers to a variable or its size depends on an expression
2440 that's not a compile-time constant. */
2443 }
2446 {
2447 /* Use the size of the type of the destination buffer object
2448 as the optimistic estimate of the available space in it. */
2450 }
2452 {
2453 /* Constructing into a buffer provided by the flexible array
2454 member of a declared object (which is permitted as a G++
2455 extension). If the array member has been initialized,
2456 determine its size from the initializer. Otherwise,
2457 the array size is zero. */
2462 }
2463 else
2464 {
2465 /* Bail if neither the size of the object nor its type is known. */
2467 }
2472 {
2473 /* Avoid diagnosing flexible array members (which are accepted
2474 as an extension and diagnosed with -Wpedantic) and zero-length
2475 arrays (also an extension).
2476 Overflowing construction in one-element arrays is diagnosed
2477 only at level 2. */
2485 && !var_decl
2488 }
2490 /* The size of the buffer can only be adjusted down but not up. */
2493 /* Reduce the size of the buffer by the adjustment computed above
2494 from the offset and/or the index into the array. */
2497 else
2500 /* The minimum amount of space needed for the allocation. This
2501 is an optimistic estimate that makes it possible to detect
2502 placement new invocation for some undersize buffers but not
2503 others. */
2511 else
2515 {
2519 exact_size ?
2520 "placement new constructing an object of type "
2521 "%<%T [%wu]%> and size %qwu in a region of type %qT "
2522 "and size %qwi"
2524 "%<%T [%wu]%> and size %qwu in a region of type %qT "
2528 bytes_avail);
2529 else
2531 exact_size ?
2532 "placement new constructing an array of objects "
2533 "of type %qT and size %qwu in a region of type %qT "
2534 "and size %qwi"
2536 "of type %qT and size %qwu in a region of type %qT "
2539 bytes_avail);
2540 else
2542 exact_size ?
2543 "placement new constructing an object of type %qT "
2544 "and size %qwu in a region of type %qT and size %qwi"
2546 "and size %qwu in a region of type %qT and size "
2549 bytes_avail);
2550 }
2551 }
2552 }
2554 /* Generate code for a new-expression, including calling the "operator
2555 new" function, initializing the object, and, if an exception occurs
2556 during construction, cleaning up. The arguments are as for
2557 build_raw_new_expr. This may change PLACEMENT and INIT.
2558 TYPE is the type of the object being constructed, possibly an array
2559 of NELTS elements when NELTS is non-null (in "new T[NELTS]", T may
2560 be an array of the form U[inner], with the whole expression being
2561 "new U[NELTS][inner]"). */
2563 static tree
2566 tsubst_flags_t complain)
2567 {
2569 /* True iff this is a call to "operator new[]" instead of just
2570 "operator new". */
2572 /* If ARRAY_P is true, the element type of the array. This is never
2573 an ARRAY_TYPE; for something like "new int[3][4]", the
2574 ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
2575 TYPE. */
2576 tree elt_type;
2577 /* The type of the new-expression. (This type is always a pointer
2578 type.) */
2579 tree pointer_type;
2580 tree non_const_pointer_type;
2581 /* The most significant array bound in int[OUTER_NELTS][inner]. */
2583 /* For arrays with a non-constant number of elements, a bounds checks
2584 on the NELTS parameter to avoid integer overflow at runtime. */
2587 /* Number of the "inner" elements in "new T[OUTER_NELTS][inner]". */
2590 /* Size of the inner array elements (those with constant dimensions). */
2591 offset_int inner_size;
2592 /* The address returned by the call to "operator new". This node is
2593 a VAR_DECL and is therefore reusable. */
2594 tree alloc_node;
2595 tree alloc_fn;
2599 /* If non-NULL, the number of extra bytes to allocate at the
2600 beginning of the storage allocated for an array-new expression in
2601 order to store the number of elements. */
2603 tree placement_first;
2605 /* True if the function we are calling is a placement allocation
2606 function. */
2608 /* True if the storage must be initialized, either by a constructor
2609 or due to an explicit new-initializer. */
2611 /* The address of the thing allocated, not including any cookie. In
2612 particular, if an array cookie is in use, DATA_ADDR is the
2613 address of the first array element. This node is a VAR_DECL, and
2614 is therefore reusable. */
2615 tree data_addr;
2620 {
2623 }
2625 {
2626 /* Transforms new (T[N]) to new T[N]. The former is a GNU
2627 extension for variable N. (This also covers new T where T is
2628 a VLA typedef.) */
2634 }
2636 /* Lots of logic below. depends on whether we have a constant number of
2637 elements, so go ahead and fold it now. */
2641 /* If our base type is an array, then make sure we know how many elements
2642 it has. */
2646 {
2650 {
2655 {
2659 }
2661 }
2662 else
2663 {
2665 {
2669 }
2671 }
2675 inner_nelts_cst,
2676 complain);
2677 }
2680 {
2683 }
2688 /* Warn if we performed the (T[N]) to T[N] transformation and N is
2689 variable. */
2692 {
2694 {
2699 else
2704 }
2705 else
2707 }
2710 {
2714 }
2722 {
2724 /* A program that calls for default-initialization [...] of an
2725 entity of reference type is ill-formed. */
2729 /* A new-expression that creates an object of type T initializes
2730 that object as follows:
2731 - If the new-initializer is omitted:
2732 -- If T is a (possibly cv-qualified) non-POD class type
2733 (or array thereof), the object is default-initialized (8.5).
2734 [...]
2735 -- Otherwise, the object created has indeterminate
2736 value. If T is a const-qualified type, or a (possibly
2737 cv-qualified) POD class type (or array thereof)
2738 containing (directly or indirectly) a member of
2739 const-qualified type, the program is ill-formed; */
2749 }
2753 {
2757 }
2761 {
2762 /* Maximum available size in bytes. Half of the address space
2763 minus the cookie size. */
2764 offset_int max_size
2766 /* Maximum number of outer elements which can be allocated. */
2767 offset_int max_outer_nelts;
2768 tree max_outer_nelts_tree;
2774 /* Unconditionally subtract the cookie size. This decreases the
2775 maximum object size and is safe even if we choose not to use
2776 a cookie after all. */
2782 {
2786 }
2794 {
2796 {
2797 /* When the array size is constant, check it at compile time
2798 to make sure it doesn't exceed the implementation-defined
2799 maximum, as required by C++ 14 (in C++ 11 this requirement
2800 isn't explicitly stated but it's enforced anyway -- see
2801 grokdeclarator in cp/decl.c). */
2805 }
2806 }
2807 else
2808 {
2809 /* When a runtime check is necessary because the array size
2810 isn't constant, keep only the top-most seven bits (starting
2811 with the most significant non-zero bit) of the maximum size
2812 to compare the array size against, to simplify encoding the
2813 constant maximum size in the instruction stream. */
2820 outer_nelts,
2821 max_outer_nelts_tree);
2822 }
2823 }
2827 /* If PLACEMENT is a single simple pointer type not passed by
2828 reference, prepare to capture it in a temporary variable. Do
2829 this now, since PLACEMENT will change in the calls below. */
2837 /* Allocate the object. */
2839 {
2840 tree class_addr;
2841 tree class_decl;
2845 {
2848 }
2857 {
2861 }
2863 {
2867 }
2872 {
2876 }
2880 }
2882 {
2885 }
2886 else
2887 {
2888 tree fnname;
2889 tree fns;
2893 member_new_p = !globally_qualified_p
2895 && (array_p
2900 {
2901 /* Use a class-specific operator new. */
2902 /* If a cookie is required, add some extra space. */
2905 else
2906 {
2908 /* No size arithmetic necessary, so the size check is
2909 not needed. */
2912 }
2913 /* Perform the overflow check. */
2920 /* Create the argument list. */
2922 /* Do name-lookup to find the appropriate operator. */
2925 {
2929 }
2931 {
2933 {
2936 }
2938 }
2942 LOOKUP_NORMAL,
2944 complain);
2945 }
2946 else
2947 {
2948 /* Use a global operator new. */
2949 /* See if a cookie might be required. */
2951 {
2953 /* No size arithmetic necessary, so the size check is
2954 not needed. */
2957 }
2961 outer_nelts_check,
2963 }
2964 }
2971 /* If we found a simple case of PLACEMENT_EXPR above, then copy it
2972 into a temporary variable. */
2978 {
2984 {
2988 }
2992 {
2993 /* Attempt to make the warning point at the operator new argument. */
2998 }
2999 }
3001 /* In the simple case, we can stop now. */
3006 /* Store the result of the allocation call in a variable so that we can
3007 use it more than once. */
3011 /* Strip any COMPOUND_EXPRs from ALLOC_CALL. */
3015 /* Now, check to see if this function is actually a placement
3016 allocation function. This can happen even when PLACEMENT is NULL
3017 because we might have something like:
3019 struct S { void* operator new (size_t, int i = 0); };
3021 A call to `new S' will get this allocation function, even though
3022 there is no explicit placement argument. If there is more than
3023 one argument, or there are variable arguments, then this is a
3024 placement allocation function. */
3025 placement_allocation_fn_p
3029 /* Preevaluate the placement args so that we don't reevaluate them for a
3030 placement delete. */
3032 {
3033 tree inits;
3037 alloc_expr);
3038 }
3040 /* unless an allocation function is declared with an empty excep-
3041 tion-specification (_except.spec_), throw(), it indicates failure to
3042 allocate storage by throwing a bad_alloc exception (clause _except_,
3043 _lib.bad.alloc_); it returns a non-null pointer otherwise If the allo-
3044 cation function is declared with an empty exception-specification,
3045 throw(), it returns null to indicate failure to allocate storage and a
3046 non-null pointer otherwise.
3048 So check for a null exception spec on the op new we just called. */
3054 {
3055 tree cookie;
3056 tree cookie_ptr;
3057 tree size_ptr_type;
3059 /* Adjust so we're pointing to the start of the object. */
3062 /* Store the number of bytes allocated so that we can know how
3063 many elements to destroy later. We use the last sizeof
3064 (size_t) bytes to store the number of elements. */
3075 {
3076 /* Also store the element size. */
3087 }
3088 }
3089 else
3090 {
3093 }
3095 /* Now use a pointer to the type we've actually allocated. */
3097 /* But we want to operate on a non-const version to start with,
3098 since we'll be modifying the elements. */
3099 non_const_pointer_type = build_pointer_type
3103 /* Any further uses of alloc_node will want this type, too. */
3106 /* Now initialize the allocated object. Note that we preevaluate the
3107 initialization expression, apart from the actual constructor call or
3108 assignment--we do this because we want to delay the allocation as long
3109 as possible in order to minimize the size of the exception region for
3110 placement delete. */
3112 {
3117 {
3120 }
3123 {
3124 /* build_value_init doesn't work in templates, and we don't need
3125 the initializer anyway since we're going to throw it away and
3126 rebuild it at instantiation time, so just build up a single
3127 constructor call to get any appropriate diagnostics. */
3131 complete_ctor_identifier,
3133 LOOKUP_NORMAL,
3134 complain);
3136 }
3138 {
3142 {
3146 else
3147 {
3151 complain);
3152 else
3153 /* We'll check the length at runtime. */
3157 }
3158 }
3160 {
3164 else
3167 }
3168 init_expr
3172 integer_one_node,
3173 complain),
3174 vecinit,
3175 explicit_value_init_p,
3177 complain);
3179 /* An array initialization is stable because the initialization
3180 of each element is a full-expression, so the temporaries don't
3181 leak out. */
3183 }
3184 else
3185 {
3189 {
3191 complete_ctor_identifier,
3193 LOOKUP_NORMAL,
3194 complain);
3195 }
3197 {
3198 /* Something like `new int()'. */
3203 }
3204 else
3205 {
3206 tree ie;
3208 /* We are processing something like `new int (10)', which
3209 means allocate an int, and initialize it with 10. */
3212 complain);
3215 }
3217 }
3222 /* If any part of the object initialization terminates by throwing an
3223 exception and a suitable deallocation function can be found, the
3224 deallocation function is called to free the memory in which the
3225 object was being constructed, after which the exception continues
3226 to propagate in the context of the new-expression. If no
3227 unambiguous matching deallocation function can be found,
3228 propagating the exception does not cause the object's memory to be
3229 freed. */
3231 {
3233 tree cleanup;
3235 /* The Standard is unclear here, but the right thing to do
3236 is to use the same method for finding deallocation
3237 functions that we use for finding allocation functions. */
3238 cleanup = (build_op_delete_call
3240 alloc_node,
3241 size,
3242 globally_qualified_p,
3244 alloc_fn,
3245 complain));
3250 /* This is much simpler if we were able to preevaluate all of
3251 the arguments to the constructor call. */
3252 {
3253 /* CLEANUP is compiler-generated, so no diagnostics. */
3257 /* Likewise, this try-catch is compiler-generated. */
3259 }
3260 else
3261 /* Ack! First we allocate the memory. Then we set our sentry
3262 variable to true, and expand a cleanup that deletes the
3263 memory if sentry is true. Then we run the constructor, and
3264 finally clear the sentry.
3266 We need to do this because we allocate the space first, so
3267 if there are any temporaries with cleanups in the
3268 constructor args and we weren't able to preevaluate them, we
3269 need this EH region to extend until end of full-expression
3270 to preserve nesting. */
3271 {
3279 /* CLEANUP is compiler-generated, so no diagnostics. */
3289 init_expr
3292 end));
3293 /* Likewise, this is compiler-generated. */
3295 }
3296 }
3297 }
3298 else
3301 /* Now build up the return value in reverse order. */
3311 /* If we don't have an initializer or a cookie, strip the TARGET_EXPR
3312 and return the call (which doesn't need to be adjusted). */
3314 else
3315 {
3317 {
3320 nullptr_node,
3321 complain);
3324 }
3326 /* Perform the allocation before anything else, so that ALLOC_NODE
3327 has been initialized before we start using it. */
3329 }
3334 /* A new-expression is never an lvalue. */
3338 }
3340 /* Generate a representation for a C++ "new" expression. *PLACEMENT
3341 is a vector of placement-new arguments (or NULL if none). If NELTS
3342 is NULL, TYPE is the type of the storage to be allocated. If NELTS
3343 is not NULL, then this is an array-new allocation; TYPE is the type
3344 of the elements in the array and NELTS is the number of elements in
3345 the array. *INIT, if non-NULL, is the initializer for the new
3346 object, or an empty vector to indicate an initializer of "()". If
3347 USE_GLOBAL_NEW is true, then the user explicitly wrote "::new"
3348 rather than just "new". This may change PLACEMENT and INIT. */
3350 tree
3353 {
3354 tree rval;
3363 /* Don't do auto deduction where it might affect mangling. */
3365 {
3368 {
3372 }
3373 }
3376 {
3383 use_global_new);
3394 }
3397 {
3399 {
3402 else
3404 }
3406 /* Try to determine the constant value only for the purposes
3407 of the diagnostic below but continue to use the original
3408 value and handle const folding later. */
3411 /* The expression in a noptr-new-declarator is erroneous if it's of
3412 non-class type and its value before converting to std::size_t is
3413 less than zero. ... If the expression is a constant expression,
3414 the program is ill-fomed. */
3417 {
3421 }
3425 }
3427 /* ``A reference cannot be created by the new operator. A reference
3428 is not an object (8.2.2, 8.4.3), so a pointer to it could not be
3429 returned by new.'' ARM 5.3.3 */
3431 {
3434 else
3437 }
3440 {
3444 }
3446 /* The type allocated must be complete. If the new-type-id was
3447 "T[N]" then we are just checking that "T" is complete here, but
3448 that is equivalent, since the value of "N" doesn't matter. */
3457 {
3463 }
3465 /* Wrap it in a NOP_EXPR so warn_if_unused_value doesn't complain. */
3470 }
3472 /* Given a Java class, return a decl for the corresponding java.lang.Class. */
3474 tree
3476 {
3482 {
3485 {
3488 }
3490 }
3492 /* Mangle the class$ field. */
3493 {
3494 tree field;
3497 {
3501 }
3503 {
3506 }
3507 }
3511 {
3521 }
3523 }
3524 \f
3525 static tree
3527 special_function_kind auto_delete_vec,
3529 {
3530 tree virtual_size;
3532 tree size_exp;
3534 /* Temporary variables used by the loop. */
3537 /* This is the body of the loop that implements the deletion of a
3538 single element, and moves temp variables to next elements. */
3539 tree body;
3541 /* This is the LOOP_EXPR that governs the deletion of the elements. */
3544 /* This is the thing that governs what to do after the loop has run. */
3547 /* This is the BIND_EXPR which holds the outermost iterator of the
3548 loop. It is convenient to set this variable up and test it before
3549 executing any other code in the loop.
3550 This is also the containing expression returned by this function. */
3552 tree tmp;
3554 /* We should only have 1-D arrays here. */
3561 {
3564 "possible problem detected in invocation of "
3566 {
3569 "class-specific operator delete [] will be called, "
3571 }
3572 /* This size won't actually be used. */
3575 }
3582 {
3583 /* Make sure the destructor is callable. */
3585 {
3588 complain);
3591 }
3593 }
3595 /* The below is short by the cookie size. */
3600 tbase_init
3604 base),
3605 virtual_size),
3606 complain);
3624 complain);
3632 no_destructor:
3633 /* Delete the storage if appropriate. */
3635 {
3636 tree base_tbd;
3638 /* The below is short by the cookie size. */
3643 /* no header */
3645 else
3646 {
3647 tree cookie_size;
3651 MINUS_EXPR,
3654 cookie_size,
3655 complain);
3659 /* True size with header. */
3661 }
3668 complain);
3669 }
3673 ;
3676 else
3677 /* The delete operator mist be called, even if a destructor
3678 throws. */
3684 /* Outermost wrapper: If pointer is null, punt. */
3687 /* This is a compiler generated comparison, don't emit
3688 e.g. -Wnonnull-compare warning for it. */
3696 {
3699 }
3702 /* Pre-evaluate the SAVE_EXPR outside of the BIND_EXPR. */
3706 }
3708 /* Create an unnamed variable of the indicated TYPE. */
3710 tree
3712 {
3713 tree decl;
3723 }
3725 /* Create a new temporary variable of the indicated TYPE, initialized
3726 to INIT.
3728 It is not entered into current_binding_level, because that breaks
3729 things when it comes time to do final cleanups (which take place
3730 "outside" the binding contour of the function). */
3732 tree
3734 {
3735 tree decl;
3744 }
3746 /* Subroutine of build_vec_init. Returns true if assigning to an array of
3747 INNER_ELT_TYPE from INIT is trivial. */
3749 static bool
3751 {
3756 }
3758 /* `build_vec_init' returns tree structure that performs
3759 initialization of a vector of aggregate types.
3761 BASE is a reference to the vector, of ARRAY_TYPE, or a pointer
3762 to the first element, of POINTER_TYPE.
3763 MAXINDEX is the maximum index of the array (one less than the
3764 number of elements). It is only used if BASE is a pointer or
3765 TYPE_DOMAIN (TREE_TYPE (BASE)) == NULL_TREE.
3767 INIT is the (possibly NULL) initializer.
3769 If EXPLICIT_VALUE_INIT_P is true, then INIT must be NULL. All
3770 elements in the array are value-initialized.
3772 FROM_ARRAY is 0 if we should init everything with INIT
3773 (i.e., every element initialized from INIT).
3774 FROM_ARRAY is 1 if we should index into INIT in parallel
3775 with initialization of DECL.
3776 FROM_ARRAY is 2 if we should index into INIT in parallel,
3777 but use assignment instead of initialization. */
3779 tree
3783 {
3784 tree rval;
3787 tree iterator;
3788 /* The type of BASE. */
3790 /* The type of an element in the array. */
3792 /* The element type reached after removing all outer array
3793 types. */
3794 tree inner_elt_type;
3795 /* The type of a pointer to an element in the array. */
3796 tree ptype;
3797 tree stmt_expr;
3798 tree compound_stmt;
3819 /* Look through the TARGET_EXPR around a compound literal. */
3825 /* If we have a braced-init-list, make sure that the array
3826 is big enough for all the initializers. */
3838 /* Don't do this if the CONSTRUCTOR might contain something
3839 that might throw and require us to clean up. */
3843 {
3844 /* Do non-default initialization of trivial arrays resulting from
3845 brace-enclosed initializers. In this case, digest_init and
3846 store_constructor will handle the semantics for us. */
3852 }
3858 {
3864 }
3865 else
3868 /* The code we are generating looks like:
3869 ({
3870 T* t1 = (T*) base;
3871 T* rval = t1;
3872 ptrdiff_t iterator = maxindex;
3873 try {
3874 for (; iterator != -1; --iterator) {
3875 ... initialize *t1 ...
3876 ++t1;
3877 }
3878 } catch (...) {
3879 ... destroy elements that were constructed ...
3880 }
3881 rval;
3882 })
3884 We can omit the try and catch blocks if we know that the
3885 initialization will never throw an exception, or if the array
3886 elements do not have destructors. We can omit the loop completely if
3887 the elements of the array do not have constructors.
3889 We actually wrap the entire body of the above in a STMT_EXPR, for
3890 tidiness.
3892 When copying from array to another, when the array elements have
3893 only trivial copy constructors, we should use __builtin_memcpy
3894 rather than generating a loop. That way, we could take advantage
3895 of whatever cleverness the back end has for dealing with copies
3896 of blocks of memory. */
3905 /* If initializing one array from another, initialize element by
3906 element. We rely upon the below calls to do the argument
3907 checking. Evaluate the initializer before entering the try block. */
3909 {
3918 }
3920 /* Protect the entire array initialization so that we can destroy
3921 the partially constructed array if an exception is thrown.
3922 But don't do this if we're assigning. */
3925 {
3927 }
3929 /* Should we try to create a constant initializer? */
3933 : (type_has_constexpr_default_constructor
3939 /* If we're initializing a static array, we want to do static
3940 initialization of any elements with constant initializers even if
3941 some are non-constant. */
3947 /* Skip over the handling of non-empty init lists. */
3950 /* Maybe pull out constant value when from_array? */
3953 {
3954 /* Do non-default initialization of non-trivial arrays resulting from
3955 brace-enclosed initializers. */
3958 /* If the constructor already has the array type, it's been through
3959 digest_init, so we shouldn't try to do anything more. */
3964 {
3968 {
3970 {
3972 nelts);
3976 }
3977 /* Don't check an array new when -fno-exceptions. */
3978 }
3981 {
3982 /* Make sure the last element of the initializer is in bounds. */
3983 finish_expr_stmt
3984 (ubsan_instrument_bounds
3986 }
3987 }
3993 {
3995 tree one_init;
3997 num_initialized_elts++;
4004 else
4010 {
4013 {
4017 else
4019 }
4020 else
4021 {
4023 {
4028 }
4030 }
4031 }
4040 else
4044 complain);
4047 else
4049 }
4051 /* Any elements without explicit initializers get T{}. */
4053 }
4055 {
4060 {
4064 }
4065 }
4067 /* Now, default-initialize any remaining elements. We don't need to
4068 do that if a) the type does not need constructing, or b) we've
4069 already initialized all the elements.
4071 We do need to keep going if we're copying an array. */
4074 /* With a constexpr default constructor, which we checked for when
4075 setting try_const above, default-initialization is equivalent to
4076 value-initialization, and build_value_init gives us something more
4077 friendly to maybe_constant_init. */
4082 && (num_initialized_elts
4084 {
4085 /* If the ITERATOR is lesser or equal to -1, then we don't have to loop;
4086 we've already initialized all the elements. */
4087 tree for_stmt;
4088 tree elt_init;
4089 tree to;
4097 complain);
4104 /* If the initializer is {}, then all elements are initialized from T{}.
4105 But for non-classes, that's the same as value-initialization. */
4107 {
4109 {
4111 }
4112 else
4113 {
4116 }
4117 }
4120 {
4121 tree from;
4124 {
4128 }
4129 else
4139 complain);
4140 else
4142 }
4144 {
4146 sorry
4150 explicit_value_init_p,
4152 }
4154 {
4158 }
4159 else
4160 {
4164 else
4165 {
4168 complain);
4170 }
4171 }
4177 {
4178 /* FIXME refs to earlier elts */
4181 {
4183 /* Don't fill the CONSTRUCTOR with zeros. */
4187 }
4188 else
4189 {
4193 else
4195 }
4198 {
4201 {
4204 }
4205 }
4206 }
4214 complain));
4217 complain));
4220 }
4222 /* Make sure to cleanup any partially constructed elements. */
4225 {
4226 tree e;
4229 complain);
4231 /* Flatten multi-dimensional array since build_vec_delete only
4232 expects one-dimensional array. */
4236 /* Avoid mixing signed and unsigned. */
4239 complain);
4248 }
4250 /* The value of the array initialization is the array itself, RVAL
4251 is a pointer to the first element. */
4262 {
4264 {
4267 }
4270 else
4272 }
4274 /* Now make the result have the correct type. */
4276 {
4281 }
4284 }
4286 /* Call the DTOR_KIND destructor for EXP. FLAGS are as for
4287 build_delete. */
4289 static tree
4291 tsubst_flags_t complain)
4292 {
4293 tree name;
4294 tree fn;
4296 {
4311 }
4316 flags,
4318 complain);
4319 }
4321 /* Generate a call to a destructor. TYPE is the type to cast ADDR to.
4322 ADDR is an expression which yields the store to be destroyed.
4323 AUTO_DELETE is the name of the destructor to call, i.e., either
4324 sfk_complete_destructor, sfk_base_destructor, or
4325 sfk_deleting_destructor.
4327 FLAGS is the logical disjunction of zero or more LOOKUP_
4328 flags. See cp-tree.h for more info. */
4330 tree
4333 {
4334 tree expr;
4341 /* Can happen when CURRENT_EXCEPTION_OBJECT gets its type
4342 set to `error_mark_node' before it gets properly cleaned up. */
4350 {
4352 {
4356 }
4359 }
4362 {
4365 /* We don't want to warn about delete of void*, only other
4366 incomplete types. Deleting other incomplete types
4367 invokes undefined behavior, but it is not ill-formed, so
4368 compile to something that would even do The Right Thing
4369 (TM) should the type have a trivial dtor and no delete
4370 operator. */
4372 {
4375 {
4378 "possible problem detected in invocation of "
4380 {
4383 "neither the destructor nor the class-specific "
4384 "operator delete will be called, even if they are "
4386 }
4387 }
4391 {
4392 tree dtor;
4395 {
4398 "deleting object of abstract class type %qT"
4399 " which has non-virtual destructor"
4401 else
4403 "deleting object of polymorphic class type %qT"
4404 " which has non-virtual destructor"
4406 }
4407 }
4408 }
4412 /* Throw away const and volatile on target type of addr. */
4414 }
4415 else
4416 {
4417 /* Don't check PROTECT here; leave that decision to the
4418 destructor. If the destructor is accessible, call it,
4419 else report error. */
4427 }
4430 {
4431 /* Make sure the destructor is callable. */
4433 {
4435 complain),
4439 }
4446 use_global_delete,
4449 complain);
4450 }
4451 else
4452 {
4455 tree ifexp;
4460 /* For `::delete x', we must not use the deleting destructor
4461 since then we would not be sure to get the global `operator
4462 delete'. */
4464 {
4465 /* We will use ADDR multiple times so we must save it. */
4468 /* Delete the object. */
4470 head,
4475 complain);
4476 /* Otherwise, treat this like a complete object destructor
4477 call. */
4479 }
4480 /* If the destructor is non-virtual, there is no deleting
4481 variant. Instead, we must explicitly call the appropriate
4482 `operator delete' here. */
4485 {
4486 /* We will use ADDR multiple times so we must save it. */
4488 /* Build the call. */
4490 addr,
4495 complain);
4496 /* Call the complete object destructor. */
4498 }
4501 {
4502 /* Make sure we have access to the member op delete, even though
4503 we'll actually be calling it from the destructor. */
4508 complain);
4509 }
4516 /* The delete operator must be called, regardless of whether
4517 the destructor throws.
4519 [expr.delete]/7 The deallocation function is called
4520 regardless of whether the destructor for the object or some
4521 element of the array throws an exception. */
4524 /* We need to calculate this before the dtor changes the vptr. */
4529 /* Explicit destructor call; don't check for null pointer. */
4531 else
4532 {
4533 /* Handle deleting a null pointer. */
4539 /* This is a compiler generated comparison, don't emit
4540 e.g. -Wnonnull-compare warning for it. */
4543 }
4549 }
4550 }
4552 /* At the beginning of a destructor, push cleanups that will call the
4553 destructors for our base classes and members.
4555 Called from begin_destructor_body. */
4557 void
4559 {
4562 tree member;
4563 tree expr;
4566 /* Run destructors for all virtual baseclasses. */
4568 {
4569 tree cond = (condition_conversion
4571 current_in_charge_parm,
4572 integer_two_node)));
4574 /* The CLASSTYPE_VBASECLASSES vector is in initialization
4575 order, which is also the right order for pushing cleanups. */
4578 {
4580 {
4582 base_dtor_identifier,
4583 NULL,
4584 base_binfo,
4585 (LOOKUP_NORMAL
4587 tf_warning_or_error);
4589 {
4593 }
4594 }
4595 }
4596 }
4598 /* Take care of the remaining baseclasses. */
4601 {
4607 base_dtor_identifier,
4610 tf_warning_or_error);
4613 }
4615 /* Don't automatically destroy union members. */
4621 {
4630 {
4631 tree this_member = (build_class_member_access_expr
4635 tf_warning_or_error));
4637 sfk_complete_destructor,
4642 }
4643 }
4644 }
4646 /* Build a C++ vector delete expression.
4647 MAXINDEX is the number of elements to be deleted.
4648 ELT_SIZE is the nominal size of each element in the vector.
4649 BASE is the expression that should yield the store to be deleted.
4650 This function expands (or synthesizes) these calls itself.
4651 AUTO_DELETE_VEC says whether the container (vector) should be deallocated.
4653 This also calls delete for virtual baseclasses of elements of the vector.
4655 Update: MAXINDEX is no longer needed. The size can be extracted from the
4656 start of the vector for pointers, and from the type for arrays. We still
4657 use MAXINDEX for arrays because it happens to already have one of the
4658 values we'd have to extract. (We could use MAXINDEX with pointers to
4659 confirm the size, and trap if the numbers differ; not clear that it'd
4660 be worth bothering.) */
4662 tree
4664 special_function_kind auto_delete_vec,
4666 {
4667 tree type;
4668 tree rval;
4674 {
4675 /* Step back one from start of vector, and read dimension. */
4676 tree cookie_addr;
4681 {
4684 }
4689 cookie_addr);
4691 }
4693 {
4694 /* Get the total number of things in the array, maxindex is a
4695 bad name. */
4702 {
4705 }
4706 }
4707 else
4708 {
4712 }
4720 }