| blob | 5997d53ddb5503dd727c09f52026289f4b7f3772 |
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);
802 tf_warning_or_error));
803 }
806 {
807 tree expr;
812 tf_warning_or_error);
815 tf_warning_or_error);
820 }
821 }
823 /* Returns a TREE_LIST containing (as the TREE_PURPOSE of each node) all
824 the FIELD_DECLs on the TYPE_FIELDS list for T, in reverse order. */
826 static tree
828 {
829 tree fields;
831 /* Note whether or not T is a union. */
836 {
837 tree fieldtype;
839 /* Skip CONST_DECLs for enumeration constants and so forth. */
845 /* For an anonymous struct or union, we must recursively
846 consider the fields of the anonymous type. They can be
847 directly initialized from the constructor. */
849 {
850 /* Add this field itself. Synthesized copy constructors
851 initialize the entire aggregate. */
853 /* And now add the fields in the anonymous aggregate. */
856 }
857 /* Add this field. */
860 }
863 }
865 /* Return the innermost aggregate scope for FIELD, whether that is
866 the enclosing class or an anonymous aggregate within it. */
868 static tree
870 {
873 else
875 }
877 /* The MEM_INITS are a TREE_LIST. The TREE_PURPOSE of each list gives
878 a FIELD_DECL or BINFO in T that needs initialization. The
879 TREE_VALUE gives the initializer, or list of initializer arguments.
881 Return a TREE_LIST containing all of the initializations required
882 for T, in the order in which they should be performed. The output
883 list has the same format as the input. */
885 static tree
887 {
888 tree init;
890 tree sorted_inits;
891 tree next_subobject;
896 /* Build up a list of initializations. The TREE_PURPOSE of entry
897 will be the subobject (a FIELD_DECL or BINFO) to initialize. The
898 TREE_VALUE will be the constructor arguments, or NULL if no
899 explicit initialization was provided. */
902 /* Process the virtual bases. */
907 /* Process the direct bases. */
913 /* Process the non-static data members. */
915 /* Reverse the entire list of initializations, so that they are in
916 the order that they will actually be performed. */
919 /* If the user presented the initializers in an order different from
920 that in which they will actually occur, we issue a warning. Keep
921 track of the next subobject which can be explicitly initialized
922 without issuing a warning. */
925 /* Go through the explicit initializers, filling in TREE_PURPOSE in
926 the SORTED_INITS. */
928 {
929 tree subobject;
930 tree subobject_init;
934 /* If the explicit initializers are in sorted order, then
935 SUBOBJECT will be NEXT_SUBOBJECT, or something following
936 it. */
938 subobject_init;
943 /* Issue a warning if the explicit initializer order does not
944 match that which will actually occur.
945 ??? Are all these on the correct lines? */
947 {
952 else
958 else
962 }
964 /* Look again, from the beginning of the list. */
966 {
970 }
972 /* It is invalid to initialize the same subobject more than
973 once. */
975 {
979 subobject);
980 else
983 subobject);
984 }
986 /* Record the initialization. */
989 }
991 /* [class.base.init]
993 If a ctor-initializer specifies more than one mem-initializer for
994 multiple members of the same union (including members of
995 anonymous unions), the ctor-initializer is ill-formed.
997 Here we also splice out uninitialized union members. */
999 {
1003 {
1004 tree field;
1005 tree ctx;
1011 /* Skip base classes. */
1015 /* If this is an anonymous aggregate with no explicit initializer,
1016 splice it out. */
1020 /* See if this field is a member of a union, or a member of a
1021 structure contained in a union, etc. */
1024 /* If this field is not a member of a union, skip it. */
1029 /* If this union member has no explicit initializer and no NSDMI,
1030 splice it out. */
1033 else
1036 /* It's only an error if we have two initializers for the same
1037 union type. */
1039 {
1042 }
1044 /* See if LAST_FIELD and the field initialized by INIT are
1045 members of the same union (or the union itself). If so, there's
1046 a problem, unless they're actually members of the same structure
1047 which is itself a member of a union. For example, given:
1049 union { struct { int i; int j; }; };
1051 initializing both `i' and `j' makes sense. */
1052 ctx = common_enclosing_class
1058 {
1059 /* A mem-initializer hides an NSDMI. */
1064 else
1065 {
1068 ctx);
1070 }
1071 }
1075 next:
1078 splice:
1081 }
1082 }
1085 }
1087 /* Initialize all bases and members of CURRENT_CLASS_TYPE. MEM_INITS
1088 is a TREE_LIST giving the explicit mem-initializer-list for the
1089 constructor. The TREE_PURPOSE of each entry is a subobject (a
1090 FIELD_DECL or a BINFO) of the CURRENT_CLASS_TYPE. The TREE_VALUE
1091 is a TREE_LIST giving the arguments to the constructor or
1092 void_type_node for an empty list of arguments. */
1094 void
1096 {
1099 /* We will already have issued an error message about the fact that
1100 the type is incomplete. */
1107 {
1108 /* Delegating constructor. */
1112 }
1118 /* Sort the mem-initializers into the order in which the
1119 initializations should be performed. */
1124 /* Initialize base classes. */
1128 {
1132 /* We already have issued an error message. */
1137 {
1138 /* If these initializations are taking place in a copy constructor,
1139 the base class should probably be explicitly initialized if there
1140 is a user-defined constructor in the base class (other than the
1141 default constructor, which will be called anyway). */
1149 }
1151 /* Initialize the base. */
1154 else
1155 {
1156 tree base_addr;
1162 tf_warning_or_error),
1163 arguments,
1164 flags,
1165 tf_warning_or_error);
1167 }
1168 }
1171 /* Initialize the vptrs. */
1174 /* Initialize the data members. */
1176 {
1180 }
1181 }
1183 /* Returns the address of the vtable (i.e., the value that should be
1184 assigned to the vptr) for BINFO. */
1186 tree
1188 {
1190 tree vtbl;
1193 /* If this is a virtual primary base, then the vtable we want to store
1194 is that for the base this is being used as the primary base of. We
1195 can't simply skip the initialization, because we may be expanding the
1196 inits of a subobject constructor where the virtual base layout
1197 can be different. */
1201 /* Figure out what vtable BINFO's vtable is based on, and mark it as
1202 used. */
1206 /* Now compute the address to use when initializing the vptr. */
1212 }
1214 /* This code sets up the virtual function tables appropriate for
1215 the pointer DECL. It is a one-ply initialization.
1217 BINFO is the exact type that DECL is supposed to be. In
1218 multiple inheritance, this might mean "C's A" if C : A, B. */
1220 static void
1222 {
1224 tree vtt_index;
1226 /* Compute the initializer for vptr. */
1229 /* We may get this vptr from a VTT, if this is a subobject
1230 constructor or subobject destructor. */
1233 {
1234 tree vtbl2;
1235 tree vtt_parm;
1237 /* Compute the value to use, when there's a VTT. */
1243 /* The actual initializer is the VTT value only in the subobject
1244 constructor. In maybe_clone_body we'll substitute NULL for
1245 the vtt_parm in the case of the non-subobject constructor. */
1247 }
1249 /* Compute the location of the vtpr. */
1251 tf_warning_or_error),
1255 /* Assign the vtable to the vptr. */
1258 tf_warning_or_error));
1259 }
1261 /* If an exception is thrown in a constructor, those base classes already
1262 constructed must be destroyed. This function creates the cleanup
1263 for BINFO, which has just been constructed. If FLAG is non-NULL,
1264 it is a DECL which is nonzero when this base needs to be
1265 destroyed. */
1267 static void
1269 {
1270 tree expr;
1275 /* Call the destructor. */
1277 base_dtor_identifier,
1278 NULL,
1279 binfo,
1281 tf_warning_or_error);
1293 }
1295 /* Construct the virtual base-class VBASE passing the ARGUMENTS to its
1296 constructor. */
1298 static void
1300 {
1301 tree inner_if_stmt;
1302 tree exp;
1303 tree flag;
1305 /* If there are virtual base classes with destructors, we need to
1306 emit cleanups to destroy them if an exception is thrown during
1307 the construction process. These exception regions (i.e., the
1308 period during which the cleanups must occur) begin from the time
1309 the construction is complete to the end of the function. If we
1310 create a conditional block in which to initialize the
1311 base-classes, then the cleanup region for the virtual base begins
1312 inside a block, and ends outside of that block. This situation
1313 confuses the sjlj exception-handling code. Therefore, we do not
1314 create a single conditional block, but one for each
1315 initialization. (That way the cleanup regions always begin
1316 in the outer block.) We trust the back end to figure out
1317 that the FLAG will not change across initializations, and
1318 avoid doing multiple tests. */
1323 /* Compute the location of the virtual base. If we're
1324 constructing virtual bases, then we must be the most derived
1325 class. Therefore, we don't have to look up the virtual base;
1326 we already know where it is. */
1335 }
1337 /* Find the context in which this FIELD can be initialized. */
1339 static tree
1341 {
1344 /* Anonymous union members can be initialized in the first enclosing
1345 non-anonymous union context. */
1349 }
1351 /* Function to give error message if member initialization specification
1352 is erroneous. FIELD is the member we decided to initialize.
1353 TYPE is the type for which the initialization is being performed.
1354 FIELD must be a member of TYPE.
1356 MEMBER_NAME is the name of the member. */
1358 static int
1360 {
1364 {
1366 member_name);
1368 }
1370 {
1373 field);
1375 }
1377 {
1381 }
1383 {
1385 member_name);
1387 }
1390 }
1392 /* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
1393 is a _TYPE node or TYPE_DECL which names a base for that type.
1394 Check the validity of NAME, and return either the base _TYPE, base
1395 binfo, or the FIELD_DECL of the member. If NAME is invalid, return
1396 NULL_TREE and issue a diagnostic.
1398 An old style unnamed direct single base construction is permitted,
1399 where NAME is NULL. */
1401 tree
1403 {
1404 tree basetype;
1405 tree field;
1411 {
1412 /* This is an obsolete unnamed base class initializer. The
1413 parser will already have warned about its use. */
1415 {
1418 current_class_type);
1421 basetype = BINFO_TYPE
1426 current_class_type);
1428 }
1429 }
1431 {
1434 }
1437 else
1441 {
1442 tree class_binfo;
1443 tree direct_binfo;
1444 tree virtual_binfo;
1455 /* Look for a direct base. */
1460 /* Look for a virtual base -- unless the direct base is itself
1461 virtual. */
1465 /* [class.base.init]
1467 If a mem-initializer-id is ambiguous because it designates
1468 both a direct non-virtual base class and an inherited virtual
1469 base class, the mem-initializer is ill-formed. */
1471 {
1473 basetype);
1475 }
1478 {
1482 else
1486 }
1489 }
1490 else
1491 {
1494 else
1499 }
1502 }
1504 /* This is like `expand_member_init', only it stores one aggregate
1505 value into another.
1507 INIT comes in two flavors: it is either a value which
1508 is to be stored in EXP, or it is a parameter list
1509 to go to a constructor, which will operate on EXP.
1510 If INIT is not a parameter list for a constructor, then set
1511 LOOKUP_ONLYCONVERTING.
1512 If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
1513 the initializer, if FLAGS is 0, then it is the (init) form.
1514 If `init' is a CONSTRUCTOR, then we emit a warning message,
1515 explaining that such initializations are invalid.
1517 If INIT resolves to a CALL_EXPR which happens to return
1518 something of the type we are looking for, then we know
1519 that we can safely use that call to perform the
1520 initialization.
1522 The virtual function table pointer cannot be set up here, because
1523 we do not really know its type.
1525 This never calls operator=().
1527 When initializing, nothing is CONST.
1529 A default copy constructor may have to be used to perform the
1530 initialization.
1532 A constructor or a conversion operator may have to be used to
1533 perform the initialization, but not both, as it would be ambiguous. */
1535 tree
1537 {
1538 tree stmt_expr;
1539 tree compound_stmt;
1560 {
1561 tree itype;
1563 /* An array may not be initialized use the parenthesized
1564 initialization form -- unless the initializer is "()". */
1566 {
1570 }
1571 /* Must arrange to initialize each element of EXP
1572 from elements of INIT. */
1582 complain);
1586 /* Restore the type of init unless it was used directly. */
1590 }
1594 /* Just know that we've seen something for this node. */
1608 }
1610 static void
1612 tsubst_flags_t complain)
1613 {
1615 tree ctor_name;
1617 /* It fails because there may not be a constructor which takes
1618 its own type as the first (or only parameter), but which does
1619 take other types via a conversion. So, if the thing initializing
1620 the expression is a unit element of type X, first try X(X&),
1621 followed by initialization by X. If neither of these work
1622 out, then look hard. */
1623 tree rval;
1626 /* If we have direct-initialization from an initializer list, pull
1627 it out of the TREE_LIST so the code below can see it. */
1630 {
1634 /* Only call reshape_init if it has not been called earlier
1635 by the callers. */
1638 }
1642 /* A brace-enclosed initializer for an aggregate. In C++0x this can
1643 happen for direct-initialization, too. */
1646 /* A CONSTRUCTOR of the target's type is a previously digested
1647 initializer, whether that happened just above or in
1648 cp_parser_late_parsing_nsdmi.
1650 A TARGET_EXPR with TARGET_EXPR_DIRECT_INIT_P or TARGET_EXPR_LIST_INIT_P
1651 set represents the whole initialization, so we shouldn't build up
1652 another ctor call. */
1659 {
1660 /* Early initialization via a TARGET_EXPR only works for
1661 complete objects. */
1668 }
1672 {
1673 /* Base subobjects should only get direct-initialization. */
1677 /* Do nothing. We hit this in two cases: Reference initialization,
1678 where we aren't initializing a real variable, so we don't want
1679 to run a new constructor; and catching an exception, where we
1680 have already built up the constructor call so we could wrap it
1682 else
1687 /* We need to protect the initialization of a catch parm with a
1688 call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
1689 around the TARGET_EXPR for the copy constructor. See
1690 initialize_handler_parm. */
1691 {
1695 }
1696 else
1701 }
1706 {
1710 }
1711 else
1716 {
1717 /* Delegating constructor. */
1718 tree complete;
1719 tree base;
1722 /* Unshare the arguments for the second call. */
1725 {
1728 }
1731 complain);
1737 complain);
1740 }
1741 else
1742 {
1745 else
1748 complain);
1749 }
1755 {
1758 {
1762 }
1763 }
1765 /* FIXME put back convert_to_void? */
1768 }
1770 /* This function is responsible for initializing EXP with INIT
1771 (if any).
1773 BINFO is the binfo of the type for who we are performing the
1774 initialization. For example, if W is a virtual base class of A and B,
1775 and C : A, B.
1776 If we are initializing B, then W must contain B's W vtable, whereas
1777 were we initializing C, W must contain C's W vtable.
1779 TRUE_EXP is nonzero if it is the true expression being initialized.
1780 In this case, it may be EXP, or may just contain EXP. The reason we
1781 need this is because if EXP is a base element of TRUE_EXP, we
1782 don't necessarily know by looking at EXP where its virtual
1783 baseclass fields should really be pointing. But we do know
1784 from TRUE_EXP. In constructors, we don't know anything about
1785 the value being initialized.
1787 FLAGS is just passed to `build_new_method_call'. See that function
1788 for its description. */
1790 static void
1792 tsubst_flags_t complain)
1793 {
1799 /* Use a function returning the desired type to initialize EXP for us.
1800 If the function is a constructor, and its first argument is
1801 NULL_TREE, know that it was meant for us--just slide exp on
1802 in and expand the constructor. Constructors now come
1803 as TARGET_EXPRs. */
1807 {
1809 /* If store_init_value returns NULL_TREE, the INIT has been
1810 recorded as the DECL_INITIAL for EXP. That means there's
1811 nothing more we have to do. */
1817 }
1819 /* If an explicit -- but empty -- initializer list was present,
1820 that's value-initialization. */
1822 {
1823 /* If the type has data but no user-provided ctor, we need to zero
1824 out the object. */
1827 {
1830 /* Don't clobber already initialized virtual bases. */
1833 field_size);
1836 }
1838 /* If we don't need to mess with the constructor at all,
1839 then we're done. */
1843 /* Otherwise fall through and call the constructor. */
1845 }
1847 /* We know that expand_default_init can handle everything we want
1848 at this point. */
1850 }
1852 /* Report an error if TYPE is not a user-defined, class type. If
1853 OR_ELSE is nonzero, give an error message. */
1855 int
1857 {
1862 {
1866 }
1868 }
1870 tree
1872 {
1878 else
1880 }
1882 /* Build a reference to a member of an aggregate. This is not a C++
1883 `&', but really something which can have its address taken, and
1884 then act as a pointer to member, for example TYPE :: FIELD can have
1885 its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
1886 this expression is the operand of "&".
1888 @@ Prints out lousy diagnostics for operator <typename>
1889 @@ fields.
1891 @@ This function should be rewritten and placed in search.c. */
1893 tree
1895 tsubst_flags_t complain)
1896 {
1897 tree decl;
1900 /* class templates can come in as TEMPLATE_DECLs here. */
1913 /* Callers should call mark_used before this point. */
1918 {
1922 }
1924 /* Entities other than non-static members need no further
1925 processing. */
1932 {
1936 }
1938 /* Set up BASEBINFO for member lookup. */
1941 /* A lot of this logic is now handled in lookup_member. */
1943 {
1944 /* Go from the TREE_BASELINK to the member function info. */
1948 {
1949 /* Get rid of a potential OVERLOAD around it. */
1952 /* Unique functions are handled easily. */
1954 /* For non-static member of base class, we need a special rule
1955 for access checking [class.protected]:
1957 If the access is to form a pointer to member, the
1958 nested-name-specifier shall name the derived class
1959 (or any class derived from that class). */
1963 complain);
1964 else
1966 complain);
1971 }
1972 else
1974 }
1976 /* We need additional test besides the one in
1977 check_accessibility_of_qualified_id in case it is
1978 a pointer to non-static member. */
1980 complain);
1983 {
1984 /* If MEMBER is non-static, then the program has fallen afoul of
1985 [expr.prim]:
1987 An id-expression that denotes a nonstatic data member or
1988 nonstatic member function of a class can only be used:
1990 -- as part of a class member access (_expr.ref_) in which the
1991 object-expression refers to the member's class or a class
1992 derived from that class, or
1994 -- to form a pointer to member (_expr.unary.op_), or
1996 -- in the body of a nonstatic member function of that class or
1997 of a class derived from that class (_class.mfct.nonstatic_), or
1999 -- in a mem-initializer for a constructor for that class or for
2000 a class derived from that class (_class.base.init_). */
2002 {
2003 /* Build a representation of the qualified name suitable
2004 for use as the operand to "&" -- even though the "&" is
2005 not actually present. */
2007 /* In Microsoft mode, treat a non-static member function as if
2008 it were a pointer-to-member. */
2010 {
2013 }
2018 }
2020 {
2024 }
2026 }
2031 }
2033 /* If DECL is a scalar enumeration constant or variable with a
2034 constant initializer, return the initializer (or, its initializers,
2035 recursively); otherwise, return DECL. If STRICT_P, the
2036 initializer is only returned if DECL is a
2037 constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to
2038 return an aggregate constant. */
2040 static tree
2042 {
2044 || (strict_p
2048 {
2049 tree init;
2050 /* If DECL is a static data member in a template
2051 specialization, we must instantiate it here. The
2052 initializer for the static data member is not processed
2053 until needed; we need it now. */
2058 {
2060 /* Treat the error as a constant to avoid cascading errors on
2061 excessively recursive template instantiation (c++/9335). */
2063 else
2065 }
2066 /* Initializers in templates are generally expanded during
2067 instantiation, so before that for const int i(2)
2068 INIT is a TREE_LIST with the actual initializer as
2069 TREE_VALUE. */
2071 && init
2075 /* Instantiate a non-dependent initializer. */
2080 || (!return_aggregate_cst_ok_p
2081 /* Unless RETURN_AGGREGATE_CST_OK_P is true, do not
2082 return an aggregate constant (of which string
2083 literals are a special case), as we do not want
2084 to make inadvertent copies of such entities, and
2085 we must be sure that their addresses are the
2086 same everywhere. */
2090 /* Don't return a CONSTRUCTOR for a variable with partial run-time
2091 initialization, since it doesn't represent the entire value. */
2096 }
2098 }
2100 /* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by constant
2101 of integral or enumeration type, or a constexpr variable of scalar type,
2102 then return that value. These are those variables permitted in constant
2103 expressions by [5.19/1]. */
2105 tree
2107 {
2110 }
2112 /* Like scalar_constant_value, but can also return aggregate initializers. */
2114 tree
2116 {
2119 }
2121 /* A more relaxed version of scalar_constant_value, used by the
2122 common C/C++ code. */
2124 tree
2126 {
2129 }
2130 \f
2131 /* Common subroutines of build_new and build_vec_delete. */
2132 \f
2133 /* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
2134 the type of the object being allocated; otherwise, it's just TYPE.
2135 INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
2136 user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
2137 a vector of arguments to be provided as arguments to a placement
2138 new operator. This routine performs no semantic checks; it just
2139 creates and returns a NEW_EXPR. */
2141 static tree
2144 {
2145 tree init_list;
2146 tree new_expr;
2148 /* If INIT is NULL, the we want to store NULL_TREE in the NEW_EXPR.
2149 If INIT is not NULL, then we want to store VOID_ZERO_NODE. This
2150 permits us to distinguish the case of a missing initializer "new
2151 int" from an empty initializer "new int()". */
2156 else
2161 init_list);
2166 }
2168 /* Diagnose uninitialized const members or reference members of type
2169 TYPE. USING_NEW is used to disambiguate the diagnostic between a
2170 new expression without a new-initializer and a declaration. Returns
2171 the error count. */
2173 static int
2176 {
2177 tree field;
2184 {
2185 tree field_type;
2196 {
2199 {
2201 {
2205 else
2207 }
2208 else
2209 {
2214 else
2217 }
2220 }
2221 }
2224 {
2227 {
2229 {
2233 else
2235 }
2236 else
2237 {
2242 else
2245 }
2248 }
2249 }
2252 error_count
2255 }
2257 }
2259 int
2261 {
2263 }
2265 /* Call __cxa_bad_array_new_length to indicate that the size calculation
2266 overflowed. Pretend it returns sizetype so that it plays nicely in the
2267 COND_EXPR. */
2269 tree
2271 {
2275 NULL_TREE));
2278 }
2280 /* Attempt to find the initializer for field T in the initializer INIT,
2281 when non-null. Returns the initializer when successful and NULL
2282 otherwise. */
2283 static tree
2285 {
2292 /* Iterate over all top-level initializer elements. */
2294 {
2295 /* If the member T is found, return it. */
2299 /* Otherwise continue and/or recurse into nested initializers. */
2303 }
2305 }
2307 /* Attempt to verify that the argument, OPER, of a placement new expression
2308 refers to an object sufficiently large for an object of TYPE or an array
2309 of NELTS of such objects when NELTS is non-null, and issue a warning when
2310 it does not. SIZE specifies the size needed to construct the object or
2311 array and captures the result of NELTS * sizeof (TYPE). (SIZE could be
2312 greater when the array under construction requires a cookie to store
2313 NELTS. GCC's placement new expression stores the cookie when invoking
2314 a user-defined placement new operator function but not the default one.
2315 Placement new expressions with user-defined placement new operator are
2316 not diagnosed since we don't know how they use the buffer (this could
2317 be a future extension). */
2318 static void
2320 {
2323 /* The number of bytes to add to or subtract from the size of the provided
2324 buffer based on an offset into an array or an array element reference.
2325 Although intermediate results may be negative (as in a[3] - 2) the final
2326 result cannot be. */
2328 /* True when the size of the entire destination object should be used
2329 to compute the possibly optimistic estimate of the available space. */
2331 /* True when the reference to the destination buffer is an ADDR_EXPR. */
2336 /* Using a function argument or a (non-array) variable as an argument
2337 to placement new is not checked since it's unknown what it might
2338 point to. */
2344 /* Evaluate any constant expressions. */
2347 /* Handle the common case of array + offset expression when the offset
2348 is a constant. */
2350 {
2351 /* If the offset is comple-time constant, use it to compute a more
2352 accurate estimate of the size of the buffer. Since the operand
2353 of POINTER_PLUS_EXPR is represented as an unsigned type, convert
2354 it to signed first.
2355 Otherwise, use the size of the entire array as an optimistic
2356 estimate (this may lead to false negatives). */
2360 else
2366 }
2371 {
2374 }
2379 {
2380 /* Similar to the offset computed above, see if the array index
2381 is a compile-time constant. If so, and unless the offset was
2382 not a compile-time constant, use the index to determine the
2383 size of the buffer. Otherwise, use the entire array as
2384 an optimistic estimate of the size. */
2388 else
2389 {
2392 }
2395 }
2397 /* Refers to the declared object that constains the subobject referenced
2398 by OPER. When the object is initialized, makes it possible to determine
2399 the actual size of a flexible array member used as the buffer passed
2400 as OPER to placement new. */
2402 /* True when operand is a COMPONENT_REF, to distinguish flexible array
2403 members from arrays of unspecified size. */
2406 /* Descend into a struct or union to find the member whose address
2407 is being used as the agument. */
2409 {
2415 }
2421 {
2422 /* A possibly optimistic estimate of the number of bytes available
2423 in the destination buffer. */
2425 /* True when the estimate above is in fact the exact size
2426 of the destination buffer rather than an estimate. */
2429 /* Treat members of unions and members of structs uniformly, even
2430 though the size of a member of a union may be viewed as extending
2431 to the end of the union itself (it is by __builtin_object_size). */
2435 {
2436 /* Use the size of the entire array object when the expression
2437 refers to a variable or its size depends on an expression
2438 that's not a compile-time constant. */
2441 }
2444 {
2445 /* Use the size of the type of the destination buffer object
2446 as the optimistic estimate of the available space in it. */
2448 }
2450 {
2451 /* Constructing into a buffer provided by the flexible array
2452 member of a declared object (which is permitted as a G++
2453 extension). If the array member has been initialized,
2454 determine its size from the initializer. Otherwise,
2455 the array size is zero. */
2460 }
2461 else
2462 {
2463 /* Bail if neither the size of the object nor its type is known. */
2465 }
2470 {
2471 /* Avoid diagnosing flexible array members (which are accepted
2472 as an extension and diagnosed with -Wpedantic) and zero-length
2473 arrays (also an extension).
2474 Overflowing construction in one-element arrays is diagnosed
2475 only at level 2. */
2483 && !var_decl
2486 }
2488 /* The size of the buffer can only be adjusted down but not up. */
2491 /* Reduce the size of the buffer by the adjustment computed above
2492 from the offset and/or the index into the array. */
2495 else
2498 /* The minimum amount of space needed for the allocation. This
2499 is an optimistic estimate that makes it possible to detect
2500 placement new invocation for some undersize buffers but not
2501 others. */
2509 else
2513 {
2517 exact_size ?
2518 "placement new constructing an object of type "
2519 "%<%T [%wu]%> and size %qwu in a region of type %qT "
2520 "and size %qwi"
2522 "%<%T [%wu]%> and size %qwu in a region of type %qT "
2526 bytes_avail);
2527 else
2529 exact_size ?
2530 "placement new constructing an array of objects "
2531 "of type %qT and size %qwu in a region of type %qT "
2532 "and size %qwi"
2534 "of type %qT and size %qwu in a region of type %qT "
2537 bytes_avail);
2538 else
2540 exact_size ?
2541 "placement new constructing an object of type %qT "
2542 "and size %qwu in a region of type %qT and size %qwi"
2544 "and size %qwu in a region of type %qT and size "
2547 bytes_avail);
2548 }
2549 }
2550 }
2552 /* Generate code for a new-expression, including calling the "operator
2553 new" function, initializing the object, and, if an exception occurs
2554 during construction, cleaning up. The arguments are as for
2555 build_raw_new_expr. This may change PLACEMENT and INIT.
2556 TYPE is the type of the object being constructed, possibly an array
2557 of NELTS elements when NELTS is non-null (in "new T[NELTS]", T may
2558 be an array of the form U[inner], with the whole expression being
2559 "new U[NELTS][inner]"). */
2561 static tree
2564 tsubst_flags_t complain)
2565 {
2567 /* True iff this is a call to "operator new[]" instead of just
2568 "operator new". */
2570 /* If ARRAY_P is true, the element type of the array. This is never
2571 an ARRAY_TYPE; for something like "new int[3][4]", the
2572 ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
2573 TYPE. */
2574 tree elt_type;
2575 /* The type of the new-expression. (This type is always a pointer
2576 type.) */
2577 tree pointer_type;
2578 tree non_const_pointer_type;
2579 /* The most significant array bound in int[OUTER_NELTS][inner]. */
2581 /* For arrays with a non-constant number of elements, a bounds checks
2582 on the NELTS parameter to avoid integer overflow at runtime. */
2585 /* Number of the "inner" elements in "new T[OUTER_NELTS][inner]". */
2588 /* Size of the inner array elements (those with constant dimensions). */
2589 offset_int inner_size;
2590 /* The address returned by the call to "operator new". This node is
2591 a VAR_DECL and is therefore reusable. */
2592 tree alloc_node;
2593 tree alloc_fn;
2597 /* If non-NULL, the number of extra bytes to allocate at the
2598 beginning of the storage allocated for an array-new expression in
2599 order to store the number of elements. */
2601 tree placement_first;
2603 /* True if the function we are calling is a placement allocation
2604 function. */
2606 /* True if the storage must be initialized, either by a constructor
2607 or due to an explicit new-initializer. */
2609 /* The address of the thing allocated, not including any cookie. In
2610 particular, if an array cookie is in use, DATA_ADDR is the
2611 address of the first array element. This node is a VAR_DECL, and
2612 is therefore reusable. */
2613 tree data_addr;
2618 {
2621 }
2623 {
2624 /* Transforms new (T[N]) to new T[N]. The former is a GNU
2625 extension for variable N. (This also covers new T where T is
2626 a VLA typedef.) */
2632 }
2634 /* Lots of logic below. depends on whether we have a constant number of
2635 elements, so go ahead and fold it now. */
2639 /* If our base type is an array, then make sure we know how many elements
2640 it has. */
2644 {
2648 {
2653 {
2657 }
2659 }
2660 else
2661 {
2663 {
2667 }
2669 }
2673 inner_nelts_cst,
2674 complain);
2675 }
2678 {
2681 }
2686 /* Warn if we performed the (T[N]) to T[N] transformation and N is
2687 variable. */
2690 {
2692 {
2697 else
2702 }
2703 else
2705 }
2708 {
2712 }
2720 {
2722 /* A program that calls for default-initialization [...] of an
2723 entity of reference type is ill-formed. */
2727 /* A new-expression that creates an object of type T initializes
2728 that object as follows:
2729 - If the new-initializer is omitted:
2730 -- If T is a (possibly cv-qualified) non-POD class type
2731 (or array thereof), the object is default-initialized (8.5).
2732 [...]
2733 -- Otherwise, the object created has indeterminate
2734 value. If T is a const-qualified type, or a (possibly
2735 cv-qualified) POD class type (or array thereof)
2736 containing (directly or indirectly) a member of
2737 const-qualified type, the program is ill-formed; */
2747 }
2751 {
2755 }
2759 {
2760 /* Maximum available size in bytes. Half of the address space
2761 minus the cookie size. */
2762 offset_int max_size
2764 /* Maximum number of outer elements which can be allocated. */
2765 offset_int max_outer_nelts;
2766 tree max_outer_nelts_tree;
2772 /* Unconditionally subtract the cookie size. This decreases the
2773 maximum object size and is safe even if we choose not to use
2774 a cookie after all. */
2780 {
2784 }
2792 {
2794 {
2795 /* When the array size is constant, check it at compile time
2796 to make sure it doesn't exceed the implementation-defined
2797 maximum, as required by C++ 14 (in C++ 11 this requirement
2798 isn't explicitly stated but it's enforced anyway -- see
2799 grokdeclarator in cp/decl.c). */
2803 }
2804 }
2805 else
2806 {
2807 /* When a runtime check is necessary because the array size
2808 isn't constant, keep only the top-most seven bits (starting
2809 with the most significant non-zero bit) of the maximum size
2810 to compare the array size against, to simplify encoding the
2811 constant maximum size in the instruction stream. */
2816 shift);
2819 outer_nelts,
2820 max_outer_nelts_tree);
2821 }
2822 }
2826 /* If PLACEMENT is a single simple pointer type not passed by
2827 reference, prepare to capture it in a temporary variable. Do
2828 this now, since PLACEMENT will change in the calls below. */
2836 /* Allocate the object. */
2838 {
2839 tree class_addr;
2840 tree class_decl;
2844 {
2847 }
2856 {
2860 }
2862 {
2866 }
2871 {
2875 }
2879 }
2881 {
2884 }
2885 else
2886 {
2887 tree fnname;
2888 tree fns;
2892 member_new_p = !globally_qualified_p
2894 && (array_p
2899 {
2900 /* Use a class-specific operator new. */
2901 /* If a cookie is required, add some extra space. */
2904 else
2905 {
2907 /* No size arithmetic necessary, so the size check is
2908 not needed. */
2911 }
2912 /* Perform the overflow check. */
2919 /* Create the argument list. */
2921 /* Do name-lookup to find the appropriate operator. */
2924 {
2928 }
2930 {
2932 {
2935 }
2937 }
2941 LOOKUP_NORMAL,
2943 complain);
2944 }
2945 else
2946 {
2947 /* Use a global operator new. */
2948 /* See if a cookie might be required. */
2950 {
2952 /* No size arithmetic necessary, so the size check is
2953 not needed. */
2956 }
2960 outer_nelts_check,
2962 }
2963 }
2970 /* If we found a simple case of PLACEMENT_EXPR above, then copy it
2971 into a temporary variable. */
2977 {
2983 {
2987 }
2991 {
2992 /* Attempt to make the warning point at the operator new argument. */
2997 }
2998 }
3000 /* In the simple case, we can stop now. */
3005 /* Store the result of the allocation call in a variable so that we can
3006 use it more than once. */
3010 /* Strip any COMPOUND_EXPRs from ALLOC_CALL. */
3014 /* Now, check to see if this function is actually a placement
3015 allocation function. This can happen even when PLACEMENT is NULL
3016 because we might have something like:
3018 struct S { void* operator new (size_t, int i = 0); };
3020 A call to `new S' will get this allocation function, even though
3021 there is no explicit placement argument. If there is more than
3022 one argument, or there are variable arguments, then this is a
3023 placement allocation function. */
3024 placement_allocation_fn_p
3028 /* Preevaluate the placement args so that we don't reevaluate them for a
3029 placement delete. */
3031 {
3032 tree inits;
3036 alloc_expr);
3037 }
3039 /* unless an allocation function is declared with an empty excep-
3040 tion-specification (_except.spec_), throw(), it indicates failure to
3041 allocate storage by throwing a bad_alloc exception (clause _except_,
3042 _lib.bad.alloc_); it returns a non-null pointer otherwise If the allo-
3043 cation function is declared with an empty exception-specification,
3044 throw(), it returns null to indicate failure to allocate storage and a
3045 non-null pointer otherwise.
3047 So check for a null exception spec on the op new we just called. */
3053 {
3054 tree cookie;
3055 tree cookie_ptr;
3056 tree size_ptr_type;
3058 /* Adjust so we're pointing to the start of the object. */
3061 /* Store the number of bytes allocated so that we can know how
3062 many elements to destroy later. We use the last sizeof
3063 (size_t) bytes to store the number of elements. */
3074 {
3075 /* Also store the element size. */
3086 }
3087 }
3088 else
3089 {
3092 }
3094 /* Now use a pointer to the type we've actually allocated. */
3096 /* But we want to operate on a non-const version to start with,
3097 since we'll be modifying the elements. */
3098 non_const_pointer_type = build_pointer_type
3102 /* Any further uses of alloc_node will want this type, too. */
3105 /* Now initialize the allocated object. Note that we preevaluate the
3106 initialization expression, apart from the actual constructor call or
3107 assignment--we do this because we want to delay the allocation as long
3108 as possible in order to minimize the size of the exception region for
3109 placement delete. */
3111 {
3116 {
3119 }
3122 {
3123 /* build_value_init doesn't work in templates, and we don't need
3124 the initializer anyway since we're going to throw it away and
3125 rebuild it at instantiation time, so just build up a single
3126 constructor call to get any appropriate diagnostics. */
3130 complete_ctor_identifier,
3132 LOOKUP_NORMAL,
3133 complain);
3135 }
3137 {
3141 {
3145 else
3146 {
3150 complain);
3151 else
3152 /* We'll check the length at runtime. */
3156 }
3157 }
3159 {
3163 else
3166 }
3167 init_expr
3171 integer_one_node,
3172 complain),
3173 vecinit,
3174 explicit_value_init_p,
3176 complain);
3178 /* An array initialization is stable because the initialization
3179 of each element is a full-expression, so the temporaries don't
3180 leak out. */
3182 }
3183 else
3184 {
3188 {
3190 complete_ctor_identifier,
3192 LOOKUP_NORMAL,
3193 complain);
3194 }
3196 {
3197 /* Something like `new int()'. */
3202 }
3203 else
3204 {
3205 tree ie;
3207 /* We are processing something like `new int (10)', which
3208 means allocate an int, and initialize it with 10. */
3211 complain);
3213 complain);
3214 }
3216 }
3221 /* If any part of the object initialization terminates by throwing an
3222 exception and a suitable deallocation function can be found, the
3223 deallocation function is called to free the memory in which the
3224 object was being constructed, after which the exception continues
3225 to propagate in the context of the new-expression. If no
3226 unambiguous matching deallocation function can be found,
3227 propagating the exception does not cause the object's memory to be
3228 freed. */
3230 {
3232 tree cleanup;
3234 /* The Standard is unclear here, but the right thing to do
3235 is to use the same method for finding deallocation
3236 functions that we use for finding allocation functions. */
3237 cleanup = (build_op_delete_call
3239 alloc_node,
3240 size,
3241 globally_qualified_p,
3243 alloc_fn,
3244 complain));
3249 /* This is much simpler if we were able to preevaluate all of
3250 the arguments to the constructor call. */
3251 {
3252 /* CLEANUP is compiler-generated, so no diagnostics. */
3256 /* Likewise, this try-catch is compiler-generated. */
3258 }
3259 else
3260 /* Ack! First we allocate the memory. Then we set our sentry
3261 variable to true, and expand a cleanup that deletes the
3262 memory if sentry is true. Then we run the constructor, and
3263 finally clear the sentry.
3265 We need to do this because we allocate the space first, so
3266 if there are any temporaries with cleanups in the
3267 constructor args and we weren't able to preevaluate them, we
3268 need this EH region to extend until end of full-expression
3269 to preserve nesting. */
3270 {
3278 /* CLEANUP is compiler-generated, so no diagnostics. */
3288 init_expr
3291 end));
3292 /* Likewise, this is compiler-generated. */
3294 }
3295 }
3296 }
3297 else
3300 /* Now build up the return value in reverse order. */
3310 /* If we don't have an initializer or a cookie, strip the TARGET_EXPR
3311 and return the call (which doesn't need to be adjusted). */
3313 else
3314 {
3316 {
3319 nullptr_node,
3320 complain);
3323 }
3325 /* Perform the allocation before anything else, so that ALLOC_NODE
3326 has been initialized before we start using it. */
3328 }
3333 /* A new-expression is never an lvalue. */
3337 }
3339 /* Generate a representation for a C++ "new" expression. *PLACEMENT
3340 is a vector of placement-new arguments (or NULL if none). If NELTS
3341 is NULL, TYPE is the type of the storage to be allocated. If NELTS
3342 is not NULL, then this is an array-new allocation; TYPE is the type
3343 of the elements in the array and NELTS is the number of elements in
3344 the array. *INIT, if non-NULL, is the initializer for the new
3345 object, or an empty vector to indicate an initializer of "()". If
3346 USE_GLOBAL_NEW is true, then the user explicitly wrote "::new"
3347 rather than just "new". This may change PLACEMENT and INIT. */
3349 tree
3352 {
3353 tree rval;
3362 /* Don't do auto deduction where it might affect mangling. */
3364 {
3367 {
3371 }
3372 }
3375 {
3382 use_global_new);
3393 }
3396 {
3398 {
3401 else
3403 }
3405 /* Try to determine the constant value only for the purposes
3406 of the diagnostic below but continue to use the original
3407 value and handle const folding later. */
3410 /* The expression in a noptr-new-declarator is erroneous if it's of
3411 non-class type and its value before converting to std::size_t is
3412 less than zero. ... If the expression is a constant expression,
3413 the program is ill-fomed. */
3416 {
3420 }
3424 }
3426 /* ``A reference cannot be created by the new operator. A reference
3427 is not an object (8.2.2, 8.4.3), so a pointer to it could not be
3428 returned by new.'' ARM 5.3.3 */
3430 {
3433 else
3436 }
3439 {
3443 }
3445 /* The type allocated must be complete. If the new-type-id was
3446 "T[N]" then we are just checking that "T" is complete here, but
3447 that is equivalent, since the value of "N" doesn't matter. */
3456 {
3462 }
3464 /* Wrap it in a NOP_EXPR so warn_if_unused_value doesn't complain. */
3469 }
3471 /* Given a Java class, return a decl for the corresponding java.lang.Class. */
3473 tree
3475 {
3481 {
3484 {
3487 }
3489 }
3491 /* Mangle the class$ field. */
3492 {
3493 tree field;
3496 {
3500 }
3502 {
3505 }
3506 }
3510 {
3520 }
3522 }
3523 \f
3524 static tree
3526 special_function_kind auto_delete_vec,
3528 {
3529 tree virtual_size;
3531 tree size_exp;
3533 /* Temporary variables used by the loop. */
3536 /* This is the body of the loop that implements the deletion of a
3537 single element, and moves temp variables to next elements. */
3538 tree body;
3540 /* This is the LOOP_EXPR that governs the deletion of the elements. */
3543 /* This is the thing that governs what to do after the loop has run. */
3546 /* This is the BIND_EXPR which holds the outermost iterator of the
3547 loop. It is convenient to set this variable up and test it before
3548 executing any other code in the loop.
3549 This is also the containing expression returned by this function. */
3551 tree tmp;
3553 /* We should only have 1-D arrays here. */
3560 {
3563 "possible problem detected in invocation of "
3565 {
3568 "class-specific operator delete [] will be called, "
3570 }
3571 /* This size won't actually be used. */
3574 }
3581 {
3582 /* Make sure the destructor is callable. */
3584 {
3587 complain);
3590 }
3592 }
3594 /* The below is short by the cookie size. */
3599 tbase_init
3603 base),
3604 virtual_size),
3605 complain);
3623 complain);
3631 no_destructor:
3632 /* Delete the storage if appropriate. */
3634 {
3635 tree base_tbd;
3637 /* The below is short by the cookie size. */
3642 /* no header */
3644 else
3645 {
3646 tree cookie_size;
3650 MINUS_EXPR,
3653 cookie_size,
3654 complain);
3658 /* True size with header. */
3660 }
3667 complain);
3668 }
3672 ;
3675 else
3681 /* Outermost wrapper: If pointer is null, punt. */
3684 /* This is a compiler generated comparison, don't emit
3685 e.g. -Wnonnull-compare warning for it. */
3693 {
3696 }
3699 /* Pre-evaluate the SAVE_EXPR outside of the BIND_EXPR. */
3703 }
3705 /* Create an unnamed variable of the indicated TYPE. */
3707 tree
3709 {
3710 tree decl;
3720 }
3722 /* Create a new temporary variable of the indicated TYPE, initialized
3723 to INIT.
3725 It is not entered into current_binding_level, because that breaks
3726 things when it comes time to do final cleanups (which take place
3727 "outside" the binding contour of the function). */
3729 tree
3731 {
3732 tree decl;
3738 tf_warning_or_error));
3741 }
3743 /* Subroutine of build_vec_init. Returns true if assigning to an array of
3744 INNER_ELT_TYPE from INIT is trivial. */
3746 static bool
3748 {
3753 }
3755 /* `build_vec_init' returns tree structure that performs
3756 initialization of a vector of aggregate types.
3758 BASE is a reference to the vector, of ARRAY_TYPE, or a pointer
3759 to the first element, of POINTER_TYPE.
3760 MAXINDEX is the maximum index of the array (one less than the
3761 number of elements). It is only used if BASE is a pointer or
3762 TYPE_DOMAIN (TREE_TYPE (BASE)) == NULL_TREE.
3764 INIT is the (possibly NULL) initializer.
3766 If EXPLICIT_VALUE_INIT_P is true, then INIT must be NULL. All
3767 elements in the array are value-initialized.
3769 FROM_ARRAY is 0 if we should init everything with INIT
3770 (i.e., every element initialized from INIT).
3771 FROM_ARRAY is 1 if we should index into INIT in parallel
3772 with initialization of DECL.
3773 FROM_ARRAY is 2 if we should index into INIT in parallel,
3774 but use assignment instead of initialization. */
3776 tree
3780 {
3781 tree rval;
3784 tree iterator;
3785 /* The type of BASE. */
3787 /* The type of an element in the array. */
3789 /* The element type reached after removing all outer array
3790 types. */
3791 tree inner_elt_type;
3792 /* The type of a pointer to an element in the array. */
3793 tree ptype;
3794 tree stmt_expr;
3795 tree compound_stmt;
3816 /* Look through the TARGET_EXPR around a compound literal. */
3822 /* If we have a braced-init-list, make sure that the array
3823 is big enough for all the initializers. */
3835 /* Don't do this if the CONSTRUCTOR might contain something
3836 that might throw and require us to clean up. */
3840 {
3841 /* Do non-default initialization of trivial arrays resulting from
3842 brace-enclosed initializers. In this case, digest_init and
3843 store_constructor will handle the semantics for us. */
3849 }
3855 {
3861 }
3862 else
3865 /* The code we are generating looks like:
3866 ({
3867 T* t1 = (T*) base;
3868 T* rval = t1;
3869 ptrdiff_t iterator = maxindex;
3870 try {
3871 for (; iterator != -1; --iterator) {
3872 ... initialize *t1 ...
3873 ++t1;
3874 }
3875 } catch (...) {
3876 ... destroy elements that were constructed ...
3877 }
3878 rval;
3879 })
3881 We can omit the try and catch blocks if we know that the
3882 initialization will never throw an exception, or if the array
3883 elements do not have destructors. We can omit the loop completely if
3884 the elements of the array do not have constructors.
3886 We actually wrap the entire body of the above in a STMT_EXPR, for
3887 tidiness.
3889 When copying from array to another, when the array elements have
3890 only trivial copy constructors, we should use __builtin_memcpy
3891 rather than generating a loop. That way, we could take advantage
3892 of whatever cleverness the back end has for dealing with copies
3893 of blocks of memory. */
3902 /* If initializing one array from another, initialize element by
3903 element. We rely upon the below calls to do the argument
3904 checking. Evaluate the initializer before entering the try block. */
3906 {
3915 }
3917 /* Protect the entire array initialization so that we can destroy
3918 the partially constructed array if an exception is thrown.
3919 But don't do this if we're assigning. */
3922 {
3924 }
3926 /* Should we try to create a constant initializer? */
3930 : (type_has_constexpr_default_constructor
3936 /* If we're initializing a static array, we want to do static
3937 initialization of any elements with constant initializers even if
3938 some are non-constant. */
3944 /* Skip over the handling of non-empty init lists. */
3947 /* Maybe pull out constant value when from_array? */
3950 {
3951 /* Do non-default initialization of non-trivial arrays resulting from
3952 brace-enclosed initializers. */
3955 /* If the constructor already has the array type, it's been through
3956 digest_init, so we shouldn't try to do anything more. */
3961 {
3965 {
3967 {
3969 nelts);
3973 }
3974 /* Don't check an array new when -fno-exceptions. */
3975 }
3978 {
3979 /* Make sure the last element of the initializer is in bounds. */
3980 finish_expr_stmt
3981 (ubsan_instrument_bounds
3983 }
3984 }
3990 {
3992 tree one_init;
3994 num_initialized_elts++;
4001 else
4007 {
4010 {
4014 else
4016 }
4017 else
4018 {
4020 {
4025 }
4027 }
4028 }
4037 else
4041 complain);
4044 else
4046 }
4048 /* Any elements without explicit initializers get T{}. */
4050 }
4052 {
4057 {
4061 }
4062 }
4064 /* Now, default-initialize any remaining elements. We don't need to
4065 do that if a) the type does not need constructing, or b) we've
4066 already initialized all the elements.
4068 We do need to keep going if we're copying an array. */
4071 /* With a constexpr default constructor, which we checked for when
4072 setting try_const above, default-initialization is equivalent to
4073 value-initialization, and build_value_init gives us something more
4074 friendly to maybe_constant_init. */
4079 && (num_initialized_elts
4081 {
4082 /* If the ITERATOR is lesser or equal to -1, then we don't have to loop;
4083 we've already initialized all the elements. */
4084 tree for_stmt;
4085 tree elt_init;
4086 tree to;
4094 complain);
4101 /* If the initializer is {}, then all elements are initialized from T{}.
4102 But for non-classes, that's the same as value-initialization. */
4104 {
4106 {
4108 }
4109 else
4110 {
4113 }
4114 }
4117 {
4118 tree from;
4121 {
4125 }
4126 else
4131 complain);
4136 complain);
4137 else
4139 }
4141 {
4143 sorry
4147 explicit_value_init_p,
4149 }
4151 {
4155 }
4156 else
4157 {
4161 else
4162 {
4165 complain);
4167 }
4168 }
4174 {
4175 /* FIXME refs to earlier elts */
4178 {
4180 /* Don't fill the CONSTRUCTOR with zeros. */
4184 }
4185 else
4186 {
4190 else
4192 }
4195 {
4198 {
4201 }
4202 }
4203 }
4211 complain));
4214 complain));
4217 }
4219 /* Make sure to cleanup any partially constructed elements. */
4222 {
4223 tree e;
4226 complain);
4228 /* Flatten multi-dimensional array since build_vec_delete only
4229 expects one-dimensional array. */
4233 /* Avoid mixing signed and unsigned. */
4236 complain);
4245 }
4247 /* The value of the array initialization is the array itself, RVAL
4248 is a pointer to the first element. */
4259 {
4261 {
4264 }
4267 else
4269 }
4271 /* Now make the result have the correct type. */
4273 {
4278 }
4281 }
4283 /* Call the DTOR_KIND destructor for EXP. FLAGS are as for
4284 build_delete. */
4286 static tree
4288 tsubst_flags_t complain)
4289 {
4290 tree name;
4291 tree fn;
4293 {
4308 }
4313 flags,
4315 complain);
4316 }
4318 /* Generate a call to a destructor. TYPE is the type to cast ADDR to.
4319 ADDR is an expression which yields the store to be destroyed.
4320 AUTO_DELETE is the name of the destructor to call, i.e., either
4321 sfk_complete_destructor, sfk_base_destructor, or
4322 sfk_deleting_destructor.
4324 FLAGS is the logical disjunction of zero or more LOOKUP_
4325 flags. See cp-tree.h for more info. */
4327 tree
4330 {
4331 tree expr;
4338 /* Can happen when CURRENT_EXCEPTION_OBJECT gets its type
4339 set to `error_mark_node' before it gets properly cleaned up. */
4347 {
4349 {
4353 }
4356 }
4359 {
4362 /* We don't want to warn about delete of void*, only other
4363 incomplete types. Deleting other incomplete types
4364 invokes undefined behavior, but it is not ill-formed, so
4365 compile to something that would even do The Right Thing
4366 (TM) should the type have a trivial dtor and no delete
4367 operator. */
4369 {
4372 {
4375 "possible problem detected in invocation of "
4377 {
4380 "neither the destructor nor the class-specific "
4381 "operator delete will be called, even if they are "
4383 }
4384 }
4388 {
4389 tree dtor;
4392 {
4395 "deleting object of abstract class type %qT"
4396 " which has non-virtual destructor"
4398 else
4400 "deleting object of polymorphic class type %qT"
4401 " which has non-virtual destructor"
4403 }
4404 }
4405 }
4409 /* Throw away const and volatile on target type of addr. */
4411 }
4412 else
4413 {
4414 /* Don't check PROTECT here; leave that decision to the
4415 destructor. If the destructor is accessible, call it,
4416 else report error. */
4424 }
4427 {
4428 /* Make sure the destructor is callable. */
4430 {
4432 complain),
4436 }
4443 use_global_delete,
4446 complain);
4447 }
4448 else
4449 {
4452 tree ifexp;
4457 /* For `::delete x', we must not use the deleting destructor
4458 since then we would not be sure to get the global `operator
4459 delete'. */
4461 {
4462 /* We will use ADDR multiple times so we must save it. */
4465 /* Delete the object. */
4467 head,
4472 complain);
4473 /* Otherwise, treat this like a complete object destructor
4474 call. */
4476 }
4477 /* If the destructor is non-virtual, there is no deleting
4478 variant. Instead, we must explicitly call the appropriate
4479 `operator delete' here. */
4482 {
4483 /* We will use ADDR multiple times so we must save it. */
4485 /* Build the call. */
4487 addr,
4492 complain);
4493 /* Call the complete object destructor. */
4495 }
4498 {
4499 /* Make sure we have access to the member op delete, even though
4500 we'll actually be calling it from the destructor. */
4505 complain);
4506 }
4515 /* We need to calculate this before the dtor changes the vptr. */
4520 /* Explicit destructor call; don't check for null pointer. */
4522 else
4523 {
4524 /* Handle deleting a null pointer. */
4530 /* This is a compiler generated comparison, don't emit
4531 e.g. -Wnonnull-compare warning for it. */
4534 }
4540 }
4541 }
4543 /* At the beginning of a destructor, push cleanups that will call the
4544 destructors for our base classes and members.
4546 Called from begin_destructor_body. */
4548 void
4550 {
4553 tree member;
4554 tree expr;
4557 /* Run destructors for all virtual baseclasses. */
4559 {
4560 tree cond = (condition_conversion
4562 current_in_charge_parm,
4563 integer_two_node)));
4565 /* The CLASSTYPE_VBASECLASSES vector is in initialization
4566 order, which is also the right order for pushing cleanups. */
4569 {
4571 {
4573 base_dtor_identifier,
4574 NULL,
4575 base_binfo,
4576 (LOOKUP_NORMAL
4578 tf_warning_or_error);
4580 {
4584 }
4585 }
4586 }
4587 }
4589 /* Take care of the remaining baseclasses. */
4592 {
4598 base_dtor_identifier,
4601 tf_warning_or_error);
4604 }
4606 /* Don't automatically destroy union members. */
4612 {
4621 {
4622 tree this_member = (build_class_member_access_expr
4626 tf_warning_or_error));
4628 sfk_complete_destructor,
4633 }
4634 }
4635 }
4637 /* Build a C++ vector delete expression.
4638 MAXINDEX is the number of elements to be deleted.
4639 ELT_SIZE is the nominal size of each element in the vector.
4640 BASE is the expression that should yield the store to be deleted.
4641 This function expands (or synthesizes) these calls itself.
4642 AUTO_DELETE_VEC says whether the container (vector) should be deallocated.
4644 This also calls delete for virtual baseclasses of elements of the vector.
4646 Update: MAXINDEX is no longer needed. The size can be extracted from the
4647 start of the vector for pointers, and from the type for arrays. We still
4648 use MAXINDEX for arrays because it happens to already have one of the
4649 values we'd have to extract. (We could use MAXINDEX with pointers to
4650 confirm the size, and trap if the numbers differ; not clear that it'd
4651 be worth bothering.) */
4653 tree
4655 special_function_kind auto_delete_vec,
4657 {
4658 tree type;
4659 tree rval;
4665 {
4666 /* Step back one from start of vector, and read dimension. */
4667 tree cookie_addr;
4672 {
4675 }
4680 cookie_addr);
4682 }
4684 {
4685 /* Get the total number of things in the array, maxindex is a
4686 bad name. */
4693 {
4696 }
4697 }
4698 else
4699 {
4703 }
4711 }