| blob | 9f7b614a2938e207e25bf7853268f02930077df7 |
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. */
1250 vtbl2,
1251 vtbl);
1252 }
1254 /* Compute the location of the vtpr. */
1256 tf_warning_or_error),
1260 /* Assign the vtable to the vptr. */
1263 tf_warning_or_error));
1264 }
1266 /* If an exception is thrown in a constructor, those base classes already
1267 constructed must be destroyed. This function creates the cleanup
1268 for BINFO, which has just been constructed. If FLAG is non-NULL,
1269 it is a DECL which is nonzero when this base needs to be
1270 destroyed. */
1272 static void
1274 {
1275 tree expr;
1280 /* Call the destructor. */
1282 base_dtor_identifier,
1283 NULL,
1284 binfo,
1286 tf_warning_or_error);
1298 }
1300 /* Construct the virtual base-class VBASE passing the ARGUMENTS to its
1301 constructor. */
1303 static void
1305 {
1306 tree inner_if_stmt;
1307 tree exp;
1308 tree flag;
1310 /* If there are virtual base classes with destructors, we need to
1311 emit cleanups to destroy them if an exception is thrown during
1312 the construction process. These exception regions (i.e., the
1313 period during which the cleanups must occur) begin from the time
1314 the construction is complete to the end of the function. If we
1315 create a conditional block in which to initialize the
1316 base-classes, then the cleanup region for the virtual base begins
1317 inside a block, and ends outside of that block. This situation
1318 confuses the sjlj exception-handling code. Therefore, we do not
1319 create a single conditional block, but one for each
1320 initialization. (That way the cleanup regions always begin
1321 in the outer block.) We trust the back end to figure out
1322 that the FLAG will not change across initializations, and
1323 avoid doing multiple tests. */
1328 /* Compute the location of the virtual base. If we're
1329 constructing virtual bases, then we must be the most derived
1330 class. Therefore, we don't have to look up the virtual base;
1331 we already know where it is. */
1340 }
1342 /* Find the context in which this FIELD can be initialized. */
1344 static tree
1346 {
1349 /* Anonymous union members can be initialized in the first enclosing
1350 non-anonymous union context. */
1354 }
1356 /* Function to give error message if member initialization specification
1357 is erroneous. FIELD is the member we decided to initialize.
1358 TYPE is the type for which the initialization is being performed.
1359 FIELD must be a member of TYPE.
1361 MEMBER_NAME is the name of the member. */
1363 static int
1365 {
1369 {
1371 member_name);
1373 }
1375 {
1378 field);
1380 }
1382 {
1386 }
1388 {
1390 member_name);
1392 }
1395 }
1397 /* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
1398 is a _TYPE node or TYPE_DECL which names a base for that type.
1399 Check the validity of NAME, and return either the base _TYPE, base
1400 binfo, or the FIELD_DECL of the member. If NAME is invalid, return
1401 NULL_TREE and issue a diagnostic.
1403 An old style unnamed direct single base construction is permitted,
1404 where NAME is NULL. */
1406 tree
1408 {
1409 tree basetype;
1410 tree field;
1416 {
1417 /* This is an obsolete unnamed base class initializer. The
1418 parser will already have warned about its use. */
1420 {
1423 current_class_type);
1426 basetype = BINFO_TYPE
1431 current_class_type);
1433 }
1434 }
1436 {
1439 }
1442 else
1446 {
1447 tree class_binfo;
1448 tree direct_binfo;
1449 tree virtual_binfo;
1460 /* Look for a direct base. */
1465 /* Look for a virtual base -- unless the direct base is itself
1466 virtual. */
1470 /* [class.base.init]
1472 If a mem-initializer-id is ambiguous because it designates
1473 both a direct non-virtual base class and an inherited virtual
1474 base class, the mem-initializer is ill-formed. */
1476 {
1478 basetype);
1480 }
1483 {
1487 else
1491 }
1494 }
1495 else
1496 {
1499 else
1504 }
1507 }
1509 /* This is like `expand_member_init', only it stores one aggregate
1510 value into another.
1512 INIT comes in two flavors: it is either a value which
1513 is to be stored in EXP, or it is a parameter list
1514 to go to a constructor, which will operate on EXP.
1515 If INIT is not a parameter list for a constructor, then set
1516 LOOKUP_ONLYCONVERTING.
1517 If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
1518 the initializer, if FLAGS is 0, then it is the (init) form.
1519 If `init' is a CONSTRUCTOR, then we emit a warning message,
1520 explaining that such initializations are invalid.
1522 If INIT resolves to a CALL_EXPR which happens to return
1523 something of the type we are looking for, then we know
1524 that we can safely use that call to perform the
1525 initialization.
1527 The virtual function table pointer cannot be set up here, because
1528 we do not really know its type.
1530 This never calls operator=().
1532 When initializing, nothing is CONST.
1534 A default copy constructor may have to be used to perform the
1535 initialization.
1537 A constructor or a conversion operator may have to be used to
1538 perform the initialization, but not both, as it would be ambiguous. */
1540 tree
1542 {
1543 tree stmt_expr;
1544 tree compound_stmt;
1565 {
1566 tree itype;
1568 /* An array may not be initialized use the parenthesized
1569 initialization form -- unless the initializer is "()". */
1571 {
1575 }
1576 /* Must arrange to initialize each element of EXP
1577 from elements of INIT. */
1587 complain);
1591 /* Restore the type of init unless it was used directly. */
1595 }
1599 /* Just know that we've seen something for this node. */
1613 }
1615 static void
1617 tsubst_flags_t complain)
1618 {
1620 tree ctor_name;
1622 /* It fails because there may not be a constructor which takes
1623 its own type as the first (or only parameter), but which does
1624 take other types via a conversion. So, if the thing initializing
1625 the expression is a unit element of type X, first try X(X&),
1626 followed by initialization by X. If neither of these work
1627 out, then look hard. */
1628 tree rval;
1631 /* If we have direct-initialization from an initializer list, pull
1632 it out of the TREE_LIST so the code below can see it. */
1635 {
1639 }
1643 /* A brace-enclosed initializer for an aggregate. In C++0x this can
1644 happen for direct-initialization, too. */
1645 {
1648 }
1650 /* A CONSTRUCTOR of the target's type is a previously digested
1651 initializer, whether that happened just above or in
1652 cp_parser_late_parsing_nsdmi.
1654 A TARGET_EXPR with TARGET_EXPR_DIRECT_INIT_P or TARGET_EXPR_LIST_INIT_P
1655 set represents the whole initialization, so we shouldn't build up
1656 another ctor call. */
1663 {
1664 /* Early initialization via a TARGET_EXPR only works for
1665 complete objects. */
1672 }
1676 {
1677 /* Base subobjects should only get direct-initialization. */
1681 /* Do nothing. We hit this in two cases: Reference initialization,
1682 where we aren't initializing a real variable, so we don't want
1683 to run a new constructor; and catching an exception, where we
1684 have already built up the constructor call so we could wrap it
1686 else
1691 /* We need to protect the initialization of a catch parm with a
1692 call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
1693 around the TARGET_EXPR for the copy constructor. See
1694 initialize_handler_parm. */
1695 {
1699 }
1700 else
1705 }
1710 {
1714 }
1715 else
1720 {
1721 /* Delegating constructor. */
1722 tree complete;
1723 tree base;
1726 /* Unshare the arguments for the second call. */
1729 {
1732 }
1735 complain);
1741 complain);
1746 base,
1747 complete);
1748 }
1749 else
1750 {
1753 else
1756 complain);
1757 }
1763 {
1766 {
1770 }
1771 }
1773 /* FIXME put back convert_to_void? */
1776 }
1778 /* This function is responsible for initializing EXP with INIT
1779 (if any).
1781 BINFO is the binfo of the type for who we are performing the
1782 initialization. For example, if W is a virtual base class of A and B,
1783 and C : A, B.
1784 If we are initializing B, then W must contain B's W vtable, whereas
1785 were we initializing C, W must contain C's W vtable.
1787 TRUE_EXP is nonzero if it is the true expression being initialized.
1788 In this case, it may be EXP, or may just contain EXP. The reason we
1789 need this is because if EXP is a base element of TRUE_EXP, we
1790 don't necessarily know by looking at EXP where its virtual
1791 baseclass fields should really be pointing. But we do know
1792 from TRUE_EXP. In constructors, we don't know anything about
1793 the value being initialized.
1795 FLAGS is just passed to `build_new_method_call'. See that function
1796 for its description. */
1798 static void
1800 tsubst_flags_t complain)
1801 {
1807 /* Use a function returning the desired type to initialize EXP for us.
1808 If the function is a constructor, and its first argument is
1809 NULL_TREE, know that it was meant for us--just slide exp on
1810 in and expand the constructor. Constructors now come
1811 as TARGET_EXPRs. */
1815 {
1817 /* If store_init_value returns NULL_TREE, the INIT has been
1818 recorded as the DECL_INITIAL for EXP. That means there's
1819 nothing more we have to do. */
1825 }
1827 /* If an explicit -- but empty -- initializer list was present,
1828 that's value-initialization. */
1830 {
1831 /* If the type has data but no user-provided ctor, we need to zero
1832 out the object. */
1835 {
1838 /* Don't clobber already initialized virtual bases. */
1841 field_size);
1844 }
1846 /* If we don't need to mess with the constructor at all,
1847 then we're done. */
1851 /* Otherwise fall through and call the constructor. */
1853 }
1855 /* We know that expand_default_init can handle everything we want
1856 at this point. */
1858 }
1860 /* Report an error if TYPE is not a user-defined, class type. If
1861 OR_ELSE is nonzero, give an error message. */
1863 int
1865 {
1870 {
1874 }
1876 }
1878 tree
1880 {
1886 else
1888 }
1890 /* Build a reference to a member of an aggregate. This is not a C++
1891 `&', but really something which can have its address taken, and
1892 then act as a pointer to member, for example TYPE :: FIELD can have
1893 its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
1894 this expression is the operand of "&".
1896 @@ Prints out lousy diagnostics for operator <typename>
1897 @@ fields.
1899 @@ This function should be rewritten and placed in search.c. */
1901 tree
1903 tsubst_flags_t complain)
1904 {
1905 tree decl;
1908 /* class templates can come in as TEMPLATE_DECLs here. */
1921 /* Callers should call mark_used before this point. */
1926 {
1930 }
1932 /* Entities other than non-static members need no further
1933 processing. */
1940 {
1944 }
1946 /* Set up BASEBINFO for member lookup. */
1949 /* A lot of this logic is now handled in lookup_member. */
1951 {
1952 /* Go from the TREE_BASELINK to the member function info. */
1956 {
1957 /* Get rid of a potential OVERLOAD around it. */
1960 /* Unique functions are handled easily. */
1962 /* For non-static member of base class, we need a special rule
1963 for access checking [class.protected]:
1965 If the access is to form a pointer to member, the
1966 nested-name-specifier shall name the derived class
1967 (or any class derived from that class). */
1971 complain);
1972 else
1974 complain);
1979 }
1980 else
1982 }
1984 /* We need additional test besides the one in
1985 check_accessibility_of_qualified_id in case it is
1986 a pointer to non-static member. */
1988 complain);
1991 {
1992 /* If MEMBER is non-static, then the program has fallen afoul of
1993 [expr.prim]:
1995 An id-expression that denotes a nonstatic data member or
1996 nonstatic member function of a class can only be used:
1998 -- as part of a class member access (_expr.ref_) in which the
1999 object-expression refers to the member's class or a class
2000 derived from that class, or
2002 -- to form a pointer to member (_expr.unary.op_), or
2004 -- in the body of a nonstatic member function of that class or
2005 of a class derived from that class (_class.mfct.nonstatic_), or
2007 -- in a mem-initializer for a constructor for that class or for
2008 a class derived from that class (_class.base.init_). */
2010 {
2011 /* Build a representation of the qualified name suitable
2012 for use as the operand to "&" -- even though the "&" is
2013 not actually present. */
2015 /* In Microsoft mode, treat a non-static member function as if
2016 it were a pointer-to-member. */
2018 {
2021 }
2026 }
2028 {
2032 }
2034 }
2039 }
2041 /* If DECL is a scalar enumeration constant or variable with a
2042 constant initializer, return the initializer (or, its initializers,
2043 recursively); otherwise, return DECL. If STRICT_P, the
2044 initializer is only returned if DECL is a
2045 constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to
2046 return an aggregate constant. */
2048 static tree
2050 {
2052 || (strict_p
2056 {
2057 tree init;
2058 /* If DECL is a static data member in a template
2059 specialization, we must instantiate it here. The
2060 initializer for the static data member is not processed
2061 until needed; we need it now. */
2066 {
2068 /* Treat the error as a constant to avoid cascading errors on
2069 excessively recursive template instantiation (c++/9335). */
2071 else
2073 }
2074 /* Initializers in templates are generally expanded during
2075 instantiation, so before that for const int i(2)
2076 INIT is a TREE_LIST with the actual initializer as
2077 TREE_VALUE. */
2079 && init
2083 /* Instantiate a non-dependent initializer. */
2088 || (!return_aggregate_cst_ok_p
2089 /* Unless RETURN_AGGREGATE_CST_OK_P is true, do not
2090 return an aggregate constant (of which string
2091 literals are a special case), as we do not want
2092 to make inadvertent copies of such entities, and
2093 we must be sure that their addresses are the
2094 same everywhere. */
2098 /* Don't return a CONSTRUCTOR for a variable with partial run-time
2099 initialization, since it doesn't represent the entire value. */
2104 }
2106 }
2108 /* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by constant
2109 of integral or enumeration type, or a constexpr variable of scalar type,
2110 then return that value. These are those variables permitted in constant
2111 expressions by [5.19/1]. */
2113 tree
2115 {
2118 }
2120 /* Like scalar_constant_value, but can also return aggregate initializers. */
2122 tree
2124 {
2127 }
2129 /* A more relaxed version of scalar_constant_value, used by the
2130 common C/C++ code. */
2132 tree
2134 {
2137 }
2138 \f
2139 /* Common subroutines of build_new and build_vec_delete. */
2140 \f
2141 /* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
2142 the type of the object being allocated; otherwise, it's just TYPE.
2143 INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
2144 user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
2145 a vector of arguments to be provided as arguments to a placement
2146 new operator. This routine performs no semantic checks; it just
2147 creates and returns a NEW_EXPR. */
2149 static tree
2152 {
2153 tree init_list;
2154 tree new_expr;
2156 /* If INIT is NULL, the we want to store NULL_TREE in the NEW_EXPR.
2157 If INIT is not NULL, then we want to store VOID_ZERO_NODE. This
2158 permits us to distinguish the case of a missing initializer "new
2159 int" from an empty initializer "new int()". */
2164 else
2169 init_list);
2174 }
2176 /* Diagnose uninitialized const members or reference members of type
2177 TYPE. USING_NEW is used to disambiguate the diagnostic between a
2178 new expression without a new-initializer and a declaration. Returns
2179 the error count. */
2181 static int
2184 {
2185 tree field;
2192 {
2193 tree field_type;
2204 {
2207 {
2209 {
2213 else
2215 }
2216 else
2217 {
2222 else
2225 }
2228 }
2229 }
2232 {
2235 {
2237 {
2241 else
2243 }
2244 else
2245 {
2250 else
2253 }
2256 }
2257 }
2260 error_count
2263 }
2265 }
2267 int
2269 {
2271 }
2273 /* Call __cxa_bad_array_new_length to indicate that the size calculation
2274 overflowed. Pretend it returns sizetype so that it plays nicely in the
2275 COND_EXPR. */
2277 tree
2279 {
2283 NULL_TREE));
2286 }
2288 /* Attempt to verify that the argument, OPER, of a placement new expression
2289 refers to an object sufficiently large for an object of TYPE or an array
2290 of NELTS of such objects when NELTS is non-null, and issue a warning when
2291 it does not. SIZE specifies the size needed to construct the object or
2292 array and captures the result of NELTS * sizeof (TYPE). (SIZE could be
2293 greater when the array under construction requires a cookie to store
2294 NELTS. GCC's placement new expression stores the cookie when invoking
2295 a user-defined placement new operator function but not the default one.
2296 Placement new expressions with user-defined placement new operator are
2297 not diagnosed since we don't know how they use the buffer (this could
2298 be a future extension). */
2299 static void
2301 {
2304 /* The number of bytes to add to or subtract from the size of the provided
2305 buffer based on an offset into an array or an array element reference.
2306 Although intermediate results may be negative (as in a[3] - 2) the final
2307 result cannot be. */
2309 /* True when the size of the entire destination object should be used
2310 to compute the possibly optimistic estimate of the available space. */
2312 /* True when the reference to the destination buffer is an ADDR_EXPR. */
2317 /* Using a function argument or a (non-array) variable as an argument
2318 to placement new is not checked since it's unknown what it might
2319 point to. */
2325 /* Evaluate any constant expressions. */
2328 /* Handle the common case of array + offset expression when the offset
2329 is a constant. */
2331 {
2332 /* If the offset is comple-time constant, use it to compute a more
2333 accurate estimate of the size of the buffer. Since the operand
2334 of POINTER_PLUS_EXPR is represented as an unsigned type, convert
2335 it to signed first.
2336 Otherwise, use the size of the entire array as an optimistic
2337 estimate (this may lead to false negatives). */
2341 else
2347 }
2352 {
2355 }
2360 {
2361 /* Similar to the offset computed above, see if the array index
2362 is a compile-time constant. If so, and unless the offset was
2363 not a compile-time constant, use the index to determine the
2364 size of the buffer. Otherwise, use the entire array as
2365 an optimistic estimate of the size. */
2369 else
2370 {
2373 }
2376 }
2378 /* Descend into a struct or union to find the member whose address
2379 is being used as the agument. */
2387 {
2388 /* A possibly optimistic estimate of the number of bytes available
2389 in the destination buffer. */
2391 /* True when the estimate above is in fact the exact size
2392 of the destination buffer rather than an estimate. */
2395 /* Treat members of unions and members of structs uniformly, even
2396 though the size of a member of a union may be viewed as extending
2397 to the end of the union itself (it is by __builtin_object_size). */
2400 {
2401 /* Use the size of the entire array object when the expression
2402 refers to a variable or its size depends on an expression
2403 that's not a compile-time constant. */
2406 }
2408 {
2409 /* Use the size of the type of the destination buffer object
2410 as the optimistic estimate of the available space in it. */
2412 }
2413 else
2414 {
2415 /* Bail if neither the size of the object nor its type is known. */
2417 }
2419 /* Avoid diagnosing flexible array members (accepted as an extension
2420 and diagnosed with -Wpedantic).
2421 Constructing objects that appear to overflow the C99 equivalent of
2422 flexible array members (i.e., array members of size zero or one)
2423 are diagnosed in C++ since their declaration cannot be diagnosed. */
2427 /* The size of the buffer can only be adjusted down but not up. */
2430 /* Reduce the size of the buffer by the adjustment computed above
2431 from the offset and/or the index into the array. */
2434 else
2437 /* The minimum amount of space needed for the allocation. This
2438 is an optimistic estimate that makes it possible to detect
2439 placement new invocation for some undersize buffers but not
2440 others. */
2448 else
2452 {
2456 exact_size ?
2457 "placement new constructing an object of type "
2458 "%<%T [%wu]%> and size %qwu in a region of type %qT "
2459 "and size %qwi"
2461 "%<%T [%wu]%> and size %qwu in a region of type %qT "
2465 bytes_avail);
2466 else
2468 exact_size ?
2469 "placement new constructing an array of objects "
2470 "of type %qT and size %qwu in a region of type %qT "
2471 "and size %qwi"
2473 "of type %qT and size %qwu in a region of type %qT "
2476 bytes_avail);
2477 else
2479 exact_size ?
2480 "placement new constructing an object of type %qT "
2481 "and size %qwu in a region of type %qT and size %qwi"
2483 "and size %qwu in a region of type %qT and size "
2486 bytes_avail);
2487 }
2488 }
2489 }
2491 /* Generate code for a new-expression, including calling the "operator
2492 new" function, initializing the object, and, if an exception occurs
2493 during construction, cleaning up. The arguments are as for
2494 build_raw_new_expr. This may change PLACEMENT and INIT.
2495 TYPE is the type of the object being constructed, possibly an array
2496 of NELTS elements when NELTS is non-null (in "new T[NELTS]", T may
2497 be an array of the form U[inner], with the whole expression being
2498 "new U[NELTS][inner]"). */
2500 static tree
2503 tsubst_flags_t complain)
2504 {
2506 /* True iff this is a call to "operator new[]" instead of just
2507 "operator new". */
2509 /* If ARRAY_P is true, the element type of the array. This is never
2510 an ARRAY_TYPE; for something like "new int[3][4]", the
2511 ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
2512 TYPE. */
2513 tree elt_type;
2514 /* The type of the new-expression. (This type is always a pointer
2515 type.) */
2516 tree pointer_type;
2517 tree non_const_pointer_type;
2518 /* The most significant array bound in int[OUTER_NELTS][inner]. */
2520 /* For arrays with a non-constant number of elements, a bounds checks
2521 on the NELTS parameter to avoid integer overflow at runtime. */
2524 /* Number of the "inner" elements in "new T[OUTER_NELTS][inner]". */
2527 /* Size of the inner array elements (those with constant dimensions). */
2528 offset_int inner_size;
2529 /* The address returned by the call to "operator new". This node is
2530 a VAR_DECL and is therefore reusable. */
2531 tree alloc_node;
2532 tree alloc_fn;
2536 /* If non-NULL, the number of extra bytes to allocate at the
2537 beginning of the storage allocated for an array-new expression in
2538 order to store the number of elements. */
2540 tree placement_first;
2542 /* True if the function we are calling is a placement allocation
2543 function. */
2545 /* True if the storage must be initialized, either by a constructor
2546 or due to an explicit new-initializer. */
2548 /* The address of the thing allocated, not including any cookie. In
2549 particular, if an array cookie is in use, DATA_ADDR is the
2550 address of the first array element. This node is a VAR_DECL, and
2551 is therefore reusable. */
2552 tree data_addr;
2557 {
2560 }
2562 {
2563 /* Transforms new (T[N]) to new T[N]. The former is a GNU
2564 extension for variable N. (This also covers new T where T is
2565 a VLA typedef.) */
2571 }
2573 /* Lots of logic below. depends on whether we have a constant number of
2574 elements, so go ahead and fold it now. */
2578 /* If our base type is an array, then make sure we know how many elements
2579 it has. */
2583 {
2587 {
2592 {
2596 }
2598 }
2599 else
2600 {
2602 {
2606 }
2608 }
2612 inner_nelts_cst,
2613 complain);
2614 }
2617 {
2620 }
2625 /* Warn if we performed the (T[N]) to T[N] transformation and N is
2626 variable. */
2629 {
2631 {
2636 else
2641 }
2642 else
2644 }
2647 {
2651 }
2659 {
2661 /* A program that calls for default-initialization [...] of an
2662 entity of reference type is ill-formed. */
2666 /* A new-expression that creates an object of type T initializes
2667 that object as follows:
2668 - If the new-initializer is omitted:
2669 -- If T is a (possibly cv-qualified) non-POD class type
2670 (or array thereof), the object is default-initialized (8.5).
2671 [...]
2672 -- Otherwise, the object created has indeterminate
2673 value. If T is a const-qualified type, or a (possibly
2674 cv-qualified) POD class type (or array thereof)
2675 containing (directly or indirectly) a member of
2676 const-qualified type, the program is ill-formed; */
2686 }
2690 {
2694 }
2698 {
2699 /* Maximum available size in bytes. Half of the address space
2700 minus the cookie size. */
2701 offset_int max_size
2703 /* Maximum number of outer elements which can be allocated. */
2704 offset_int max_outer_nelts;
2705 tree max_outer_nelts_tree;
2711 /* Unconditionally subtract the cookie size. This decreases the
2712 maximum object size and is safe even if we choose not to use
2713 a cookie after all. */
2719 {
2723 }
2731 {
2733 {
2734 /* When the array size is constant, check it at compile time
2735 to make sure it doesn't exceed the implementation-defined
2736 maximum, as required by C++ 14 (in C++ 11 this requirement
2737 isn't explicitly stated but it's enforced anyway -- see
2738 grokdeclarator in cp/decl.c). */
2742 }
2743 }
2744 else
2745 {
2746 /* When a runtime check is necessary because the array size
2747 isn't constant, keep only the top-most seven bits (starting
2748 with the most significant non-zero bit) of the maximum size
2749 to compare the array size against, to simplify encoding the
2750 constant maximum size in the instruction stream. */
2755 shift);
2758 outer_nelts,
2759 max_outer_nelts_tree);
2760 }
2761 }
2765 /* If PLACEMENT is a single simple pointer type not passed by
2766 reference, prepare to capture it in a temporary variable. Do
2767 this now, since PLACEMENT will change in the calls below. */
2775 /* Allocate the object. */
2777 {
2778 tree class_addr;
2779 tree class_decl;
2783 {
2786 }
2795 {
2799 }
2801 {
2805 }
2810 }
2812 {
2815 }
2816 else
2817 {
2818 tree fnname;
2819 tree fns;
2823 member_new_p = !globally_qualified_p
2825 && (array_p
2830 {
2831 /* Use a class-specific operator new. */
2832 /* If a cookie is required, add some extra space. */
2835 else
2836 {
2838 /* No size arithmetic necessary, so the size check is
2839 not needed. */
2842 }
2843 /* Perform the overflow check. */
2850 /* Create the argument list. */
2852 /* Do name-lookup to find the appropriate operator. */
2855 {
2859 }
2861 {
2863 {
2866 }
2868 }
2872 LOOKUP_NORMAL,
2874 complain);
2875 }
2876 else
2877 {
2878 /* Use a global operator new. */
2879 /* See if a cookie might be required. */
2881 {
2883 /* No size arithmetic necessary, so the size check is
2884 not needed. */
2887 }
2891 outer_nelts_check,
2893 }
2894 }
2901 /* If we found a simple case of PLACEMENT_EXPR above, then copy it
2902 into a temporary variable. */
2908 {
2914 {
2918 }
2922 {
2923 /* Attempt to make the warning point at the operator new argument. */
2928 }
2929 }
2931 /* In the simple case, we can stop now. */
2936 /* Store the result of the allocation call in a variable so that we can
2937 use it more than once. */
2941 /* Strip any COMPOUND_EXPRs from ALLOC_CALL. */
2945 /* Now, check to see if this function is actually a placement
2946 allocation function. This can happen even when PLACEMENT is NULL
2947 because we might have something like:
2949 struct S { void* operator new (size_t, int i = 0); };
2951 A call to `new S' will get this allocation function, even though
2952 there is no explicit placement argument. If there is more than
2953 one argument, or there are variable arguments, then this is a
2954 placement allocation function. */
2955 placement_allocation_fn_p
2959 /* Preevaluate the placement args so that we don't reevaluate them for a
2960 placement delete. */
2962 {
2963 tree inits;
2967 alloc_expr);
2968 }
2970 /* unless an allocation function is declared with an empty excep-
2971 tion-specification (_except.spec_), throw(), it indicates failure to
2972 allocate storage by throwing a bad_alloc exception (clause _except_,
2973 _lib.bad.alloc_); it returns a non-null pointer otherwise If the allo-
2974 cation function is declared with an empty exception-specification,
2975 throw(), it returns null to indicate failure to allocate storage and a
2976 non-null pointer otherwise.
2978 So check for a null exception spec on the op new we just called. */
2984 {
2985 tree cookie;
2986 tree cookie_ptr;
2987 tree size_ptr_type;
2989 /* Adjust so we're pointing to the start of the object. */
2992 /* Store the number of bytes allocated so that we can know how
2993 many elements to destroy later. We use the last sizeof
2994 (size_t) bytes to store the number of elements. */
3005 {
3006 /* Also store the element size. */
3017 }
3018 }
3019 else
3020 {
3023 }
3025 /* Now use a pointer to the type we've actually allocated. */
3027 /* But we want to operate on a non-const version to start with,
3028 since we'll be modifying the elements. */
3029 non_const_pointer_type = build_pointer_type
3033 /* Any further uses of alloc_node will want this type, too. */
3036 /* Now initialize the allocated object. Note that we preevaluate the
3037 initialization expression, apart from the actual constructor call or
3038 assignment--we do this because we want to delay the allocation as long
3039 as possible in order to minimize the size of the exception region for
3040 placement delete. */
3042 {
3047 {
3050 }
3053 {
3054 /* build_value_init doesn't work in templates, and we don't need
3055 the initializer anyway since we're going to throw it away and
3056 rebuild it at instantiation time, so just build up a single
3057 constructor call to get any appropriate diagnostics. */
3061 complete_ctor_identifier,
3063 LOOKUP_NORMAL,
3064 complain);
3066 }
3068 {
3072 {
3076 else
3077 {
3081 complain);
3082 else
3083 /* We'll check the length at runtime. */
3087 }
3088 }
3090 {
3094 else
3097 }
3098 init_expr
3102 integer_one_node,
3103 complain),
3104 vecinit,
3105 explicit_value_init_p,
3107 complain);
3109 /* An array initialization is stable because the initialization
3110 of each element is a full-expression, so the temporaries don't
3111 leak out. */
3113 }
3114 else
3115 {
3119 {
3121 complete_ctor_identifier,
3123 LOOKUP_NORMAL,
3124 complain);
3125 }
3127 {
3128 /* Something like `new int()'. */
3133 }
3134 else
3135 {
3136 tree ie;
3138 /* We are processing something like `new int (10)', which
3139 means allocate an int, and initialize it with 10. */
3142 complain);
3144 complain);
3145 }
3147 }
3152 /* If any part of the object initialization terminates by throwing an
3153 exception and a suitable deallocation function can be found, the
3154 deallocation function is called to free the memory in which the
3155 object was being constructed, after which the exception continues
3156 to propagate in the context of the new-expression. If no
3157 unambiguous matching deallocation function can be found,
3158 propagating the exception does not cause the object's memory to be
3159 freed. */
3161 {
3163 tree cleanup;
3165 /* The Standard is unclear here, but the right thing to do
3166 is to use the same method for finding deallocation
3167 functions that we use for finding allocation functions. */
3168 cleanup = (build_op_delete_call
3170 alloc_node,
3171 size,
3172 globally_qualified_p,
3174 alloc_fn,
3175 complain));
3180 /* This is much simpler if we were able to preevaluate all of
3181 the arguments to the constructor call. */
3182 {
3183 /* CLEANUP is compiler-generated, so no diagnostics. */
3187 /* Likewise, this try-catch is compiler-generated. */
3189 }
3190 else
3191 /* Ack! First we allocate the memory. Then we set our sentry
3192 variable to true, and expand a cleanup that deletes the
3193 memory if sentry is true. Then we run the constructor, and
3194 finally clear the sentry.
3196 We need to do this because we allocate the space first, so
3197 if there are any temporaries with cleanups in the
3198 constructor args and we weren't able to preevaluate them, we
3199 need this EH region to extend until end of full-expression
3200 to preserve nesting. */
3201 {
3209 /* CLEANUP is compiler-generated, so no diagnostics. */
3219 init_expr
3222 end));
3223 /* Likewise, this is compiler-generated. */
3225 }
3226 }
3227 }
3228 else
3231 /* Now build up the return value in reverse order. */
3241 /* If we don't have an initializer or a cookie, strip the TARGET_EXPR
3242 and return the call (which doesn't need to be adjusted). */
3244 else
3245 {
3247 {
3250 nullptr_node,
3251 complain);
3254 }
3256 /* Perform the allocation before anything else, so that ALLOC_NODE
3257 has been initialized before we start using it. */
3259 }
3264 /* A new-expression is never an lvalue. */
3268 }
3270 /* Generate a representation for a C++ "new" expression. *PLACEMENT
3271 is a vector of placement-new arguments (or NULL if none). If NELTS
3272 is NULL, TYPE is the type of the storage to be allocated. If NELTS
3273 is not NULL, then this is an array-new allocation; TYPE is the type
3274 of the elements in the array and NELTS is the number of elements in
3275 the array. *INIT, if non-NULL, is the initializer for the new
3276 object, or an empty vector to indicate an initializer of "()". If
3277 USE_GLOBAL_NEW is true, then the user explicitly wrote "::new"
3278 rather than just "new". This may change PLACEMENT and INIT. */
3280 tree
3283 {
3284 tree rval;
3293 /* Don't do auto deduction where it might affect mangling. */
3295 {
3298 {
3302 }
3303 }
3306 {
3313 use_global_new);
3324 }
3327 {
3329 {
3332 else
3334 }
3336 /* Try to determine the constant value only for the purposes
3337 of the diagnostic below but continue to use the original
3338 value and handle const folding later. */
3341 /* The expression in a noptr-new-declarator is erroneous if it's of
3342 non-class type and its value before converting to std::size_t is
3343 less than zero. ... If the expression is a constant expression,
3344 the program is ill-fomed. */
3347 {
3351 }
3355 }
3357 /* ``A reference cannot be created by the new operator. A reference
3358 is not an object (8.2.2, 8.4.3), so a pointer to it could not be
3359 returned by new.'' ARM 5.3.3 */
3361 {
3364 else
3367 }
3370 {
3374 }
3376 /* The type allocated must be complete. If the new-type-id was
3377 "T[N]" then we are just checking that "T" is complete here, but
3378 that is equivalent, since the value of "N" doesn't matter. */
3387 {
3393 }
3395 /* Wrap it in a NOP_EXPR so warn_if_unused_value doesn't complain. */
3400 }
3402 /* Given a Java class, return a decl for the corresponding java.lang.Class. */
3404 tree
3406 {
3412 {
3415 {
3418 }
3420 }
3422 /* Mangle the class$ field. */
3423 {
3424 tree field;
3427 {
3431 }
3433 {
3436 }
3437 }
3441 {
3451 }
3453 }
3454 \f
3455 static tree
3457 special_function_kind auto_delete_vec,
3459 {
3460 tree virtual_size;
3462 tree size_exp;
3464 /* Temporary variables used by the loop. */
3467 /* This is the body of the loop that implements the deletion of a
3468 single element, and moves temp variables to next elements. */
3469 tree body;
3471 /* This is the LOOP_EXPR that governs the deletion of the elements. */
3474 /* This is the thing that governs what to do after the loop has run. */
3477 /* This is the BIND_EXPR which holds the outermost iterator of the
3478 loop. It is convenient to set this variable up and test it before
3479 executing any other code in the loop.
3480 This is also the containing expression returned by this function. */
3482 tree tmp;
3484 /* We should only have 1-D arrays here. */
3491 {
3494 "possible problem detected in invocation of "
3496 {
3499 "class-specific operator delete [] will be called, "
3501 }
3502 /* This size won't actually be used. */
3505 }
3512 {
3513 /* Make sure the destructor is callable. */
3515 {
3518 complain);
3521 }
3523 }
3525 /* The below is short by the cookie size. */
3530 tbase_init
3534 base),
3535 virtual_size),
3536 complain);
3554 complain);
3562 no_destructor:
3563 /* Delete the storage if appropriate. */
3565 {
3566 tree base_tbd;
3568 /* The below is short by the cookie size. */
3573 /* no header */
3575 else
3576 {
3577 tree cookie_size;
3581 MINUS_EXPR,
3584 cookie_size,
3585 complain);
3589 /* True size with header. */
3591 }
3598 complain);
3599 }
3603 ;
3606 else
3612 /* Outermost wrapper: If pointer is null, punt. */
3617 nullptr_node)),
3622 {
3625 }
3628 /* Pre-evaluate the SAVE_EXPR outside of the BIND_EXPR. */
3632 }
3634 /* Create an unnamed variable of the indicated TYPE. */
3636 tree
3638 {
3639 tree decl;
3649 }
3651 /* Create a new temporary variable of the indicated TYPE, initialized
3652 to INIT.
3654 It is not entered into current_binding_level, because that breaks
3655 things when it comes time to do final cleanups (which take place
3656 "outside" the binding contour of the function). */
3658 tree
3660 {
3661 tree decl;
3667 tf_warning_or_error));
3670 }
3672 /* Subroutine of build_vec_init. Returns true if assigning to an array of
3673 INNER_ELT_TYPE from INIT is trivial. */
3675 static bool
3677 {
3682 }
3684 /* `build_vec_init' returns tree structure that performs
3685 initialization of a vector of aggregate types.
3687 BASE is a reference to the vector, of ARRAY_TYPE, or a pointer
3688 to the first element, of POINTER_TYPE.
3689 MAXINDEX is the maximum index of the array (one less than the
3690 number of elements). It is only used if BASE is a pointer or
3691 TYPE_DOMAIN (TREE_TYPE (BASE)) == NULL_TREE.
3693 INIT is the (possibly NULL) initializer.
3695 If EXPLICIT_VALUE_INIT_P is true, then INIT must be NULL. All
3696 elements in the array are value-initialized.
3698 FROM_ARRAY is 0 if we should init everything with INIT
3699 (i.e., every element initialized from INIT).
3700 FROM_ARRAY is 1 if we should index into INIT in parallel
3701 with initialization of DECL.
3702 FROM_ARRAY is 2 if we should index into INIT in parallel,
3703 but use assignment instead of initialization. */
3705 tree
3709 {
3710 tree rval;
3713 tree iterator;
3714 /* The type of BASE. */
3716 /* The type of an element in the array. */
3718 /* The element type reached after removing all outer array
3719 types. */
3720 tree inner_elt_type;
3721 /* The type of a pointer to an element in the array. */
3722 tree ptype;
3723 tree stmt_expr;
3724 tree compound_stmt;
3745 /* Look through the TARGET_EXPR around a compound literal. */
3751 /* If we have a braced-init-list, make sure that the array
3752 is big enough for all the initializers. */
3764 /* Don't do this if the CONSTRUCTOR might contain something
3765 that might throw and require us to clean up. */
3769 {
3770 /* Do non-default initialization of trivial arrays resulting from
3771 brace-enclosed initializers. In this case, digest_init and
3772 store_constructor will handle the semantics for us. */
3778 }
3784 {
3790 }
3791 else
3794 /* The code we are generating looks like:
3795 ({
3796 T* t1 = (T*) base;
3797 T* rval = t1;
3798 ptrdiff_t iterator = maxindex;
3799 try {
3800 for (; iterator != -1; --iterator) {
3801 ... initialize *t1 ...
3802 ++t1;
3803 }
3804 } catch (...) {
3805 ... destroy elements that were constructed ...
3806 }
3807 rval;
3808 })
3810 We can omit the try and catch blocks if we know that the
3811 initialization will never throw an exception, or if the array
3812 elements do not have destructors. We can omit the loop completely if
3813 the elements of the array do not have constructors.
3815 We actually wrap the entire body of the above in a STMT_EXPR, for
3816 tidiness.
3818 When copying from array to another, when the array elements have
3819 only trivial copy constructors, we should use __builtin_memcpy
3820 rather than generating a loop. That way, we could take advantage
3821 of whatever cleverness the back end has for dealing with copies
3822 of blocks of memory. */
3831 /* If initializing one array from another, initialize element by
3832 element. We rely upon the below calls to do the argument
3833 checking. Evaluate the initializer before entering the try block. */
3835 {
3844 }
3846 /* Protect the entire array initialization so that we can destroy
3847 the partially constructed array if an exception is thrown.
3848 But don't do this if we're assigning. */
3851 {
3853 }
3855 /* Should we try to create a constant initializer? */
3859 : (type_has_constexpr_default_constructor
3865 /* If we're initializing a static array, we want to do static
3866 initialization of any elements with constant initializers even if
3867 some are non-constant. */
3873 /* Skip over the handling of non-empty init lists. */
3876 /* Maybe pull out constant value when from_array? */
3879 {
3880 /* Do non-default initialization of non-trivial arrays resulting from
3881 brace-enclosed initializers. */
3884 /* If the constructor already has the array type, it's been through
3885 digest_init, so we shouldn't try to do anything more. */
3890 {
3894 {
3896 {
3898 nelts);
3902 }
3903 /* Don't check an array new when -fno-exceptions. */
3904 }
3907 {
3908 /* Make sure the last element of the initializer is in bounds. */
3909 finish_expr_stmt
3910 (ubsan_instrument_bounds
3912 }
3913 }
3919 {
3921 tree one_init;
3923 num_initialized_elts++;
3930 else
3936 {
3939 {
3943 else
3945 }
3946 else
3947 {
3949 {
3954 }
3956 }
3957 }
3966 else
3970 complain);
3973 else
3975 }
3977 /* Any elements without explicit initializers get T{}. */
3979 }
3981 {
3986 {
3990 }
3991 }
3993 /* Now, default-initialize any remaining elements. We don't need to
3994 do that if a) the type does not need constructing, or b) we've
3995 already initialized all the elements.
3997 We do need to keep going if we're copying an array. */
4000 /* With a constexpr default constructor, which we checked for when
4001 setting try_const above, default-initialization is equivalent to
4002 value-initialization, and build_value_init gives us something more
4003 friendly to maybe_constant_init. */
4008 && (num_initialized_elts
4010 {
4011 /* If the ITERATOR is equal to -1, then we don't have to loop;
4012 we've already initialized all the elements. */
4013 tree for_stmt;
4014 tree elt_init;
4015 tree to;
4023 complain);
4030 /* If the initializer is {}, then all elements are initialized from T{}.
4031 But for non-classes, that's the same as value-initialization. */
4033 {
4035 {
4037 }
4038 else
4039 {
4042 }
4043 }
4046 {
4047 tree from;
4050 {
4054 }
4055 else
4060 complain);
4065 complain);
4066 else
4068 }
4070 {
4072 sorry
4076 explicit_value_init_p,
4078 }
4080 {
4084 }
4085 else
4086 {
4090 else
4091 {
4094 complain);
4096 }
4097 }
4103 {
4104 /* FIXME refs to earlier elts */
4107 {
4109 /* Don't fill the CONSTRUCTOR with zeros. */
4113 }
4114 else
4115 {
4119 else
4121 }
4124 {
4127 {
4130 }
4131 }
4132 }
4140 complain));
4143 complain));
4146 }
4148 /* Make sure to cleanup any partially constructed elements. */
4151 {
4152 tree e;
4155 complain);
4157 /* Flatten multi-dimensional array since build_vec_delete only
4158 expects one-dimensional array. */
4162 /* Avoid mixing signed and unsigned. */
4165 complain);
4174 }
4176 /* The value of the array initialization is the array itself, RVAL
4177 is a pointer to the first element. */
4188 {
4190 {
4193 }
4196 else
4198 }
4200 /* Now make the result have the correct type. */
4202 {
4207 }
4210 }
4212 /* Call the DTOR_KIND destructor for EXP. FLAGS are as for
4213 build_delete. */
4215 static tree
4217 tsubst_flags_t complain)
4218 {
4219 tree name;
4220 tree fn;
4222 {
4237 }
4242 flags,
4244 complain);
4245 }
4247 /* Generate a call to a destructor. TYPE is the type to cast ADDR to.
4248 ADDR is an expression which yields the store to be destroyed.
4249 AUTO_DELETE is the name of the destructor to call, i.e., either
4250 sfk_complete_destructor, sfk_base_destructor, or
4251 sfk_deleting_destructor.
4253 FLAGS is the logical disjunction of zero or more LOOKUP_
4254 flags. See cp-tree.h for more info. */
4256 tree
4259 {
4260 tree expr;
4267 /* Can happen when CURRENT_EXCEPTION_OBJECT gets its type
4268 set to `error_mark_node' before it gets properly cleaned up. */
4276 {
4278 {
4282 }
4285 }
4288 {
4291 /* We don't want to warn about delete of void*, only other
4292 incomplete types. Deleting other incomplete types
4293 invokes undefined behavior, but it is not ill-formed, so
4294 compile to something that would even do The Right Thing
4295 (TM) should the type have a trivial dtor and no delete
4296 operator. */
4298 {
4301 {
4304 "possible problem detected in invocation of "
4306 {
4309 "neither the destructor nor the class-specific "
4310 "operator delete will be called, even if they are "
4312 }
4313 }
4317 {
4318 tree dtor;
4321 {
4324 "deleting object of abstract class type %qT"
4325 " which has non-virtual destructor"
4327 else
4329 "deleting object of polymorphic class type %qT"
4330 " which has non-virtual destructor"
4332 }
4333 }
4334 }
4338 /* Throw away const and volatile on target type of addr. */
4340 }
4341 else
4342 {
4343 /* Don't check PROTECT here; leave that decision to the
4344 destructor. If the destructor is accessible, call it,
4345 else report error. */
4353 }
4356 {
4357 /* Make sure the destructor is callable. */
4359 {
4361 complain),
4365 }
4372 use_global_delete,
4375 complain);
4376 }
4377 else
4378 {
4381 tree ifexp;
4386 /* For `::delete x', we must not use the deleting destructor
4387 since then we would not be sure to get the global `operator
4388 delete'. */
4390 {
4391 /* We will use ADDR multiple times so we must save it. */
4394 /* Delete the object. */
4396 head,
4401 complain);
4402 /* Otherwise, treat this like a complete object destructor
4403 call. */
4405 }
4406 /* If the destructor is non-virtual, there is no deleting
4407 variant. Instead, we must explicitly call the appropriate
4408 `operator delete' here. */
4411 {
4412 /* We will use ADDR multiple times so we must save it. */
4414 /* Build the call. */
4416 addr,
4421 complain);
4422 /* Call the complete object destructor. */
4424 }
4427 {
4428 /* Make sure we have access to the member op delete, even though
4429 we'll actually be calling it from the destructor. */
4434 complain);
4435 }
4444 /* We need to calculate this before the dtor changes the vptr. */
4449 /* Explicit destructor call; don't check for null pointer. */
4451 else
4452 {
4453 /* Handle deleting a null pointer. */
4457 complain));
4460 }
4466 }
4467 }
4469 /* At the beginning of a destructor, push cleanups that will call the
4470 destructors for our base classes and members.
4472 Called from begin_destructor_body. */
4474 void
4476 {
4479 tree member;
4480 tree expr;
4483 /* Run destructors for all virtual baseclasses. */
4485 {
4486 tree cond = (condition_conversion
4488 current_in_charge_parm,
4489 integer_two_node)));
4491 /* The CLASSTYPE_VBASECLASSES vector is in initialization
4492 order, which is also the right order for pushing cleanups. */
4495 {
4497 {
4499 base_dtor_identifier,
4500 NULL,
4501 base_binfo,
4502 (LOOKUP_NORMAL
4504 tf_warning_or_error);
4506 {
4510 }
4511 }
4512 }
4513 }
4515 /* Take care of the remaining baseclasses. */
4518 {
4524 base_dtor_identifier,
4527 tf_warning_or_error);
4530 }
4532 /* Don't automatically destroy union members. */
4538 {
4547 {
4548 tree this_member = (build_class_member_access_expr
4552 tf_warning_or_error));
4554 sfk_complete_destructor,
4559 }
4560 }
4561 }
4563 /* Build a C++ vector delete expression.
4564 MAXINDEX is the number of elements to be deleted.
4565 ELT_SIZE is the nominal size of each element in the vector.
4566 BASE is the expression that should yield the store to be deleted.
4567 This function expands (or synthesizes) these calls itself.
4568 AUTO_DELETE_VEC says whether the container (vector) should be deallocated.
4570 This also calls delete for virtual baseclasses of elements of the vector.
4572 Update: MAXINDEX is no longer needed. The size can be extracted from the
4573 start of the vector for pointers, and from the type for arrays. We still
4574 use MAXINDEX for arrays because it happens to already have one of the
4575 values we'd have to extract. (We could use MAXINDEX with pointers to
4576 confirm the size, and trap if the numbers differ; not clear that it'd
4577 be worth bothering.) */
4579 tree
4581 special_function_kind auto_delete_vec,
4583 {
4584 tree type;
4585 tree rval;
4591 {
4592 /* Step back one from start of vector, and read dimension. */
4593 tree cookie_addr;
4598 {
4601 }
4606 cookie_addr);
4608 }
4610 {
4611 /* Get the total number of things in the array, maxindex is a
4612 bad name. */
4619 {
4622 }
4623 }
4624 else
4625 {
4629 }
4637 }