| blob | 6a7a1b861a03ea8bb64153fc6b98066adc1e35ce |
1 /* Functions related to invoking methods and overloaded functions.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com) and
6 modified by Brendan Kehoe (brendan@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
13 any later version.
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 /* High-level class interface. */
44 /* The various kinds of conversion. */
47 ck_identity,
48 ck_lvalue,
49 ck_qual,
50 ck_std,
51 ck_ptr,
52 ck_pmem,
53 ck_base,
54 ck_ref_bind,
55 ck_user,
56 ck_ambig,
57 ck_list,
58 ck_aggr,
59 ck_rvalue
62 /* The rank of the conversion. Order of the enumerals matters; better
63 conversions should come earlier in the list. */
66 cr_identity,
67 cr_exact,
68 cr_promotion,
69 cr_std,
70 cr_pbool,
71 cr_user,
72 cr_ellipsis,
73 cr_bad
76 /* An implicit conversion sequence, in the sense of [over.best.ics].
77 The first conversion to be performed is at the end of the chain.
78 That conversion is always a cr_identity conversion. */
82 /* The kind of conversion represented by this step. */
83 conversion_kind kind;
84 /* The rank of this conversion. */
85 conversion_rank rank;
90 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
91 temporary should be created to hold the result of the
92 conversion. */
94 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
95 from a pointer-to-derived to pointer-to-base is being performed. */
97 /* If KIND is ck_ref_bind, true when either an lvalue reference is
98 being bound to an lvalue expression or an rvalue reference is
99 being bound to an rvalue expression. */
102 /* The type of the expression resulting from the conversion. */
103 tree type;
105 /* The next conversion in the chain. Since the conversions are
106 arranged from outermost to innermost, the NEXT conversion will
107 actually be performed before this conversion. This variant is
108 used only when KIND is neither ck_identity nor ck_ambig. */
110 /* The expression at the beginning of the conversion chain. This
111 variant is used only if KIND is ck_identity or ck_ambig. */
112 tree expr;
113 /* The array of conversions for an initializer_list. */
116 /* The function candidate corresponding to this conversion
117 sequence. This field is only used if KIND is ck_user. */
119 };
121 #define CONVERSION_RANK(NODE) \
122 ((NODE)->bad_p ? cr_bad \
123 : (NODE)->ellipsis_p ? cr_ellipsis \
124 : (NODE)->user_conv_p ? cr_user \
125 : (NODE)->rank)
136 #define convert_like(CONV, EXPR, COMPLAIN) \
137 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
140 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
141 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
164 static void add_builtin_candidates
167 static void add_builtin_candidate
171 static void build_builtin_candidate
176 tree);
207 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
208 NAME can take many forms... */
210 bool
212 {
213 /* Just accept something we've already complained about. */
222 {
228 else
230 }
231 else
232 {
233 /* In the case of:
235 template <class T> struct S { ~S(); };
236 int i;
237 i.~S();
239 NAME will be a class template. */
242 }
247 }
249 /* We want the address of a function or method. We avoid creating a
250 pointer-to-member function. */
252 tree
254 {
257 /* We have to do these by hand to avoid real pointer to member
258 functions. */
260 {
262 {
266 }
268 }
269 else
273 }
275 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
276 POINTER_TYPE to those. Note, pointer to member function types
277 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
278 two variants. build_call_a is the primitive taking an array of
279 arguments, while build_call_n is a wrapper that handles varargs. */
281 tree
283 {
286 else
287 {
297 }
298 }
300 tree
302 {
305 tree decl;
306 tree result_type;
307 tree fntype;
320 {
323 {
324 /* We invoke build_call directly for several library
325 functions. These may have been declared normally if
326 we're building libgcc, so we can't just check
327 DECL_ARTIFICIAL. */
332 }
333 }
334 else
337 /* We check both the decl and the type; a function may be known not to
338 throw without being declared throw(). */
352 /* Don't pass empty class objects by value. This is useful
353 for tags in STL, which are used to control overload resolution.
354 We don't need to handle other cases of copying empty classes. */
359 {
363 }
370 }
372 /* Build something of the form ptr->method (args)
373 or object.method (args). This can also build
374 calls to constructors, and find friends.
376 Member functions always take their class variable
377 as a pointer.
379 INSTANCE is a class instance.
381 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
383 PARMS help to figure out what that NAME really refers to.
385 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
386 down to the real instance type to use for access checking. We need this
387 information to get protected accesses correct.
389 FLAGS is the logical disjunction of zero or more LOOKUP_
390 flags. See cp-tree.h for more info.
392 If this is all OK, calls build_function_call with the resolved
393 member function.
395 This function must also handle being called to perform
396 initialization, promotion/coercion of arguments, and
397 instantiation of default parameters.
399 Note that NAME may refer to an instance variable name. If
400 `operator()()' is defined for the type of that field, then we return
401 that result. */
403 /* New overloading code. */
411 };
414 /* The FUNCTION_DECL that will be called if this candidate is
415 selected by overload resolution. */
416 tree fn;
417 /* If not NULL_TREE, the first argument to use when calling this
418 function. */
419 tree first_arg;
420 /* The rest of the arguments to use when calling this function. If
421 there are no further arguments this may be NULL or it may be an
422 empty vector. */
424 /* The implicit conversion sequences for each of the arguments to
425 FN. */
427 /* The number of implicit conversion sequences. */
429 /* If FN is a user-defined conversion, the standard conversion
430 sequence from the type returned by FN to the desired destination
431 type. */
434 /* If FN is a member function, the binfo indicating the path used to
435 qualify the name of FN at the call site. This path is used to
436 determine whether or not FN is accessible if it is selected by
437 overload resolution. The DECL_CONTEXT of FN will always be a
438 (possibly improper) base of this binfo. */
439 tree access_path;
440 /* If FN is a non-static member function, the binfo indicating the
441 subobject to which the `this' pointer should be converted if FN
442 is selected by overload resolution. The type pointed to the by
443 the `this' pointer must correspond to the most derived class
444 indicated by the CONVERSION_PATH. */
445 tree conversion_path;
446 tree template_decl;
449 };
451 /* Returns true iff T is a null pointer constant in the sense of
452 [conv.ptr]. */
454 bool
456 {
457 /* [conv.ptr]
459 A null pointer constant is an integral constant expression
460 (_expr.const_) rvalue of integer type that evaluates to zero. */
465 {
469 }
471 }
473 /* Returns nonzero if PARMLIST consists of only default parms and/or
474 ellipsis. */
476 bool
478 {
484 }
486 /* Allocate N bytes of memory from the conversion obstack. The memory
487 is zeroed before being returned. */
491 {
494 {
497 }
501 }
503 /* Dynamically allocate a conversion. */
507 {
512 }
514 #ifdef ENABLE_CHECKING
516 /* Make sure that all memory on the conversion obstack has been
517 freed. */
519 void
521 {
525 }
529 /* Dynamically allocate an array of N conversions. */
533 {
535 }
539 {
543 /* Note that the caller is responsible for filling in t->cand for
544 user-defined conversions. */
550 {
566 }
572 }
574 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
575 specialization of std::initializer_list<T>, if such a conversion is
576 possible. */
580 {
586 tree val;
589 {
590 conversion *sub
597 }
605 {
613 }
616 }
618 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
619 aggregate class, if such a conversion is possible. */
623 {
629 {
633 {
638 }
641 }
649 }
651 /* Build a representation of the identity conversion from EXPR to
652 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
656 {
664 }
666 /* Converting from EXPR to TYPE was ambiguous in the sense that there
667 were multiple user-defined conversions to accomplish the job.
668 Build a conversion that indicates that ambiguity. */
672 {
680 }
682 tree
684 {
688 }
690 /* Returns the standard conversion path (see [conv]) from type FROM to type
691 TO, if any. For proper handling of null pointer constants, you must
692 also pass the expression EXPR to convert from. If C_CAST_P is true,
693 this conversion is coming from a C-style cast. */
698 {
705 {
708 }
714 {
722 }
729 {
733 }
735 {
737 {
738 tree bitfield_type;
741 {
744 }
745 }
747 }
749 /* Allow conversion between `__complex__' data types. */
751 {
752 /* The standard conversion sequence to convert FROM to TO is
753 the standard conversion sequence to perform componentwise
754 conversion. */
759 {
762 }
763 else
767 }
777 {
778 /* For backwards brain damage compatibility, allow interconversion of
779 pointers and integers with a pedwarn. */
782 }
784 {
785 /* For backwards brain damage compatibility, allow interconversion of
786 enums and integers with a pedwarn. */
789 }
792 {
793 tree to_pointee;
794 tree from_pointee;
799 ;
803 {
804 from = build_pointer_type
808 }
810 {
815 && (same_type_ignoring_top_level_qualifiers_p
818 {
822 }
825 }
828 /* [conv.ptr]
830 An rvalue of type "pointer to cv D," where D is a
831 class type, can be converted to an rvalue of type
832 "pointer to cv B," where B is a base class (clause
833 _class.derived_) of D. If B is an inaccessible
834 (clause _class.access_) or ambiguous
835 (_class.member.lookup_) base class of D, a program
836 that necessitates this conversion is ill-formed.
837 Therefore, we use DERIVED_FROM_P, and do not check
838 access or uniqueness. */
840 {
841 from =
847 }
850 {
853 }
854 else
855 {
858 }
863 /* In a C-style cast, we ignore CV-qualification because we
864 are allowed to perform a static_cast followed by a
865 const_cast. */
870 /* converting from string constant to char *. */
873 {
876 }
877 else
881 }
883 {
903 }
905 {
906 /* [conv.bool]
908 An rvalue of arithmetic, unscoped enumeration, pointer, or
909 pointer to member type can be converted to an rvalue of type
910 bool. */
915 {
923 }
926 }
927 /* We don't check for ENUMERAL_TYPE here because there are no standard
928 conversions to enum type. */
929 /* As an extension, allow conversion to complex type. */
931 {
937 /* Give this a better rank if it's a promotion. */
941 }
947 {
951 /* The derived-to-base conversion indicates the initialization
952 of a parameter with base type from an object of a derived
953 type. A temporary object is created to hold the result of
954 the conversion unless we're binding directly to a reference. */
956 }
957 else
964 }
966 /* Returns nonzero if T1 is reference-related to T2. */
968 static bool
970 {
974 /* [dcl.init.ref]
976 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
977 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
978 of T2. */
982 }
984 /* Returns nonzero if T1 is reference-compatible with T2. */
986 static bool
988 {
989 /* [dcl.init.ref]
991 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
992 reference-related to T2 and cv1 is the same cv-qualification as,
993 or greater cv-qualification than, cv2. */
996 }
998 /* Determine whether or not the EXPR (of class type S) can be
999 converted to T as in [over.match.ref]. */
1003 {
1004 tree conversions;
1005 tree first_arg;
1007 tree t;
1016 /* [over.match.ref]
1018 Assuming that "cv1 T" is the underlying type of the reference
1019 being initialized, and "cv S" is the type of the initializer
1020 expression, with S a class type, the candidate functions are
1021 selected as follows:
1023 --The conversion functions of S and its base classes are
1024 considered. Those that are not hidden within S and yield type
1025 "reference to cv2 T2", where "cv1 T" is reference-compatible
1026 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1028 The argument list has one argument, which is the initializer
1029 expression. */
1033 /* Conceptually, we should take the address of EXPR and put it in
1034 the argument list. Unfortunately, however, that can result in
1035 error messages, which we should not issue now because we are just
1036 trying to find a conversion operator. Therefore, we use NULL,
1037 cast to the appropriate type. */
1043 {
1047 {
1057 /* If this is a template function, try to get an exact
1058 match. */
1060 {
1063 NULL_TREE,
1064 first_arg,
1065 NULL,
1066 reference_type,
1069 LOOKUP_NORMAL,
1070 DEDUCE_CONV);
1073 {
1074 /* Now, see if the conversion function really returns
1075 an lvalue of the appropriate type. From the
1076 point of view of unification, simply returning an
1077 rvalue of the right type is good enough. */
1082 {
1085 }
1086 }
1087 }
1093 LOOKUP_NORMAL);
1096 {
1098 /* Build a standard conversion sequence indicating the
1099 binding from the reference type returned by the
1100 function to the desired REFERENCE_TYPE. */
1101 identity_conv
1104 NULL_TREE);
1105 cand->second_conv
1106 = (direct_reference_binding
1112 }
1113 }
1114 }
1117 /* If none of the conversion functions worked out, let our caller
1118 know. */
1126 /* Now that we know that this is the function we're going to use fix
1127 the dummy first argument. */
1132 /* Build a user-defined conversion sequence representing the
1133 conversion. */
1139 /* Merge it with the standard conversion sequence from the
1140 conversion function's return type to the desired type. */
1147 }
1149 /* A reference of the indicated TYPE is being bound directly to the
1150 expression represented by the implicit conversion sequence CONV.
1151 Return a conversion sequence for this binding. */
1155 {
1156 tree t;
1163 /* [over.ics.rank]
1165 When a parameter of reference type binds directly
1166 (_dcl.init.ref_) to an argument expression, the implicit
1167 conversion sequence is the identity conversion, unless the
1168 argument expression has a type that is a derived class of the
1169 parameter type, in which case the implicit conversion sequence is
1170 a derived-to-base Conversion.
1172 If the parameter binds directly to the result of applying a
1173 conversion function to the argument expression, the implicit
1174 conversion sequence is a user-defined conversion sequence
1175 (_over.ics.user_), with the second standard conversion sequence
1176 either an identity conversion or, if the conversion function
1177 returns an entity of a type that is a derived class of the
1178 parameter type, a derived-to-base conversion. */
1180 {
1181 /* Represent the derived-to-base conversion. */
1183 /* We will actually be binding to the base-class subobject in
1184 the derived class, so we mark this conversion appropriately.
1185 That way, convert_like knows not to generate a temporary. */
1187 }
1189 }
1191 /* Returns the conversion path from type FROM to reference type TO for
1192 purposes of reference binding. For lvalue binding, either pass a
1193 reference type to FROM or an lvalue expression to EXPR. If the
1194 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1195 the conversion returned. If C_CAST_P is true, this
1196 conversion is coming from a C-style cast. */
1200 {
1204 tree tfrom;
1210 {
1215 }
1218 {
1219 /* Anything with reference type is an lvalue. */
1222 }
1230 /* Figure out whether or not the types are reference-related and
1231 reference compatible. We have do do this after stripping
1232 references from FROM. */
1234 /* If this is a C cast, first convert to an appropriately qualified
1235 type, so that we can later do a const_cast to the desired type. */
1241 /* Directly bind reference when target expression's type is compatible with
1242 the reference and expression is an lvalue. In DR391, the wording in
1243 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1244 const and rvalue references to rvalues of compatible class type. */
1246 && (lvalue_p
1250 {
1251 /* [dcl.init.ref]
1253 If the initializer expression
1255 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1256 is reference-compatible with "cv2 T2,"
1258 the reference is bound directly to the initializer expression
1259 lvalue.
1261 [...]
1262 If the initializer expression is an rvalue, with T2 a class type,
1263 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1264 is bound to the object represented by the rvalue or to a sub-object
1265 within that object. */
1271 /* The top-level caller requested that we pretend that the lvalue
1272 be treated as an rvalue. */
1274 else
1275 conv->rvaluedness_matches_p
1280 /* For the purposes of overload resolution, we ignore the fact
1281 this expression is a bitfield or packed field. (In particular,
1282 [over.ics.ref] says specifically that a function with a
1283 non-const reference parameter is viable even if the
1284 argument is a bitfield.)
1286 However, when we actually call the function we must create
1287 a temporary to which to bind the reference. If the
1288 reference is volatile, or isn't const, then we cannot make
1289 a temporary, so we just issue an error when the conversion
1290 actually occurs. */
1294 }
1295 /* [class.conv.fct] A conversion function is never used to convert a
1296 (possibly cv-qualified) object to the (possibly cv-qualified) same
1297 object type (or a reference to it), to a (possibly cv-qualified) base
1298 class of that type (or a reference to it).... */
1301 {
1302 /* [dcl.init.ref]
1304 If the initializer expression
1306 -- has a class type (i.e., T2 is a class type) can be
1307 implicitly converted to an lvalue of type "cv3 T3," where
1308 "cv1 T1" is reference-compatible with "cv3 T3". (this
1309 conversion is selected by enumerating the applicable
1310 conversion functions (_over.match.ref_) and choosing the
1311 best one through overload resolution. (_over.match_).
1313 the reference is bound to the lvalue result of the conversion
1314 in the second case. */
1318 }
1320 /* From this point on, we conceptually need temporaries, even if we
1321 elide them. Only the cases above are "direct bindings". */
1325 /* [over.ics.rank]
1327 When a parameter of reference type is not bound directly to an
1328 argument expression, the conversion sequence is the one required
1329 to convert the argument expression to the underlying type of the
1330 reference according to _over.best.ics_. Conceptually, this
1331 conversion sequence corresponds to copy-initializing a temporary
1332 of the underlying type with the argument expression. Any
1333 difference in top-level cv-qualification is subsumed by the
1334 initialization itself and does not constitute a conversion. */
1336 /* [dcl.init.ref]
1338 Otherwise, the reference shall be to a non-volatile const type.
1340 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1344 /* [dcl.init.ref]
1346 Otherwise, a temporary of type "cv1 T1" is created and
1347 initialized from the initializer expression using the rules for a
1348 non-reference copy initialization. If T1 is reference-related to
1349 T2, cv1 must be the same cv-qualification as, or greater
1350 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1354 /* We're generating a temporary now, but don't bind any more in the
1355 conversion (specifically, don't slice the temporary returned by a
1356 conversion operator). */
1359 /* Temporaries are copy-initialized, except for this hack to allow
1360 explicit conversion ops to the copy ctor. See also
1361 add_function_candidate. */
1366 flags);
1371 /* This reference binding, unlike those above, requires the
1372 creation of a temporary. */
1377 }
1379 /* Returns the implicit conversion sequence (see [over.ics]) from type
1380 FROM to type TO. The optional expression EXPR may affect the
1381 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1382 true, this conversion is coming from a C-style cast. */
1387 {
1396 else
1403 {
1407 /* Allow conversion from an initializer-list with one element to a
1408 scalar type. */
1410 {
1412 tree elt;
1418 else
1424 {
1427 /* Too many levels of braces, i.e. '{{1}}'. */
1430 }
1431 }
1432 }
1438 {
1451 /* We used to try to bind a reference to a temporary here, but that
1452 is now handled after the recursive call to this function at the end
1453 of reference_binding. */
1455 }
1458 }
1460 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1461 functions. ARGS will not be changed until a single candidate is
1462 selected. */
1470 {
1486 }
1488 /* Create an overload candidate for the function or method FN called
1489 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1490 FLAGS is passed on to implicit_conversion.
1492 This does not change ARGS.
1494 CTYPE, if non-NULL, is the type we want to pretend this function
1495 comes from for purposes of overload resolution. */
1502 {
1506 tree parmnode;
1511 /* At this point we should not see any functions which haven't been
1512 explicitly declared, except for friend functions which will have
1513 been found using argument dependent lookup. */
1516 /* The `this', `in_chrg' and VTT arguments to constructors are not
1517 considered in overload resolution. */
1519 {
1523 {
1526 }
1527 }
1528 else
1534 /* 13.3.2 - Viable functions [over.match.viable]
1535 First, to be a viable function, a candidate function shall have enough
1536 parameters to agree in number with the arguments in the list.
1538 We need to check this first; otherwise, checking the ICSes might cause
1539 us to produce an ill-formed template instantiation. */
1543 {
1547 }
1552 /* Make sure there are default args for the rest of the parms. */
1559 /* Second, for F to be a viable function, there shall exist for each
1560 argument an implicit conversion sequence that converts that argument
1561 to the corresponding parameter of F. */
1566 {
1576 else
1585 {
1589 /* The type of the implicit object parameter ('this') for
1590 overload resolution is not always the same as for the
1591 function itself; conversion functions are considered to
1592 be members of the class being converted, and functions
1593 introduced by a using-declaration are considered to be
1594 members of the class that uses them.
1596 Since build_over_call ignores the ICS for the `this'
1597 parameter, we can just change the parm type. */
1599 {
1600 parmtype
1604 }
1607 {
1608 /* Hack: Direct-initialize copy parm (i.e. suppress
1609 LOOKUP_ONLYCONVERTING) to make explicit conversion ops
1610 work. See also reference_binding. */
1614 }
1615 else
1620 }
1621 else
1622 {
1625 }
1632 {
1635 }
1642 }
1644 out:
1647 }
1649 /* Create an overload candidate for the conversion function FN which will
1650 be invoked for expression OBJ, producing a pointer-to-function which
1651 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1652 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1653 passed on to implicit_conversion.
1655 Actually, we don't really care about FN; we care about the type it
1656 converts to. There may be multiple conversion functions that will
1657 convert to that type, and we rely on build_user_type_conversion_1 to
1658 choose the best one; so when we create our candidate, we record the type
1659 instead of the function. */
1665 {
1681 /* Don't bother looking up the same type twice. */
1686 {
1694 else
1701 flags);
1707 else
1708 {
1711 }
1725 }
1735 }
1737 static void
1741 {
1756 {
1763 {
1765 /* We need something for printing the candidate. */
1767 }
1771 }
1773 /* For COND_EXPR we rearranged the arguments; undo that now. */
1775 {
1782 else
1784 }
1790 viable);
1791 }
1793 static bool
1795 {
1797 }
1799 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1801 static bool
1803 {
1804 /* [over.built]
1806 In this section, the term promoted integral type is used to refer
1807 to those integral types which are preserved by integral promotion
1808 (including e.g. int and long but excluding e.g. char).
1809 Similarly, the term promoted arithmetic type refers to promoted
1810 integral types plus floating types. */
1814 }
1816 /* Create any builtin operator overload candidates for the operator in
1817 question given the converted operand types TYPE1 and TYPE2. The other
1818 args are passed through from add_builtin_candidates to
1819 build_builtin_candidate.
1821 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1822 If CODE is requires candidates operands of the same type of the kind
1823 of which TYPE1 and TYPE2 are, we add both candidates
1824 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1826 static void
1830 {
1832 {
1840 }
1843 {
1845 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1846 and VQ is either volatile or empty, there exist candidate operator
1847 functions of the form
1848 VQ T& operator++(VQ T&);
1849 T operator++(VQ T&, int);
1850 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1851 type other than bool, and VQ is either volatile or empty, there exist
1852 candidate operator functions of the form
1853 VQ T& operator--(VQ T&);
1854 T operator--(VQ T&, int);
1855 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1856 complete object type, and VQ is either volatile or empty, there exist
1857 candidate operator functions of the form
1858 T*VQ& operator++(T*VQ&);
1859 T*VQ& operator--(T*VQ&);
1860 T* operator++(T*VQ&, int);
1861 T* operator--(T*VQ&, int); */
1870 {
1873 }
1876 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1877 exist candidate operator functions of the form
1879 T& operator*(T*);
1881 8 For every function type T, there exist candidate operator functions of
1882 the form
1883 T& operator*(T*); */
1892 /* 9 For every type T, there exist candidate operator functions of the form
1893 T* operator+(T*);
1895 10For every promoted arithmetic type T, there exist candidate operator
1896 functions of the form
1897 T operator+(T);
1898 T operator-(T); */
1908 /* 11For every promoted integral type T, there exist candidate operator
1909 functions of the form
1910 T operator~(T); */
1917 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1918 is the same type as C2 or is a derived class of C2, T is a complete
1919 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1920 there exist candidate operator functions of the form
1921 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1922 where CV12 is the union of CV1 and CV2. */
1927 {
1935 }
1938 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1939 didate operator functions of the form
1940 LR operator*(L, R);
1941 LR operator/(L, R);
1942 LR operator+(L, R);
1943 LR operator-(L, R);
1944 bool operator<(L, R);
1945 bool operator>(L, R);
1946 bool operator<=(L, R);
1947 bool operator>=(L, R);
1948 bool operator==(L, R);
1949 bool operator!=(L, R);
1950 where LR is the result of the usual arithmetic conversions between
1951 types L and R.
1953 14For every pair of types T and I, where T is a cv-qualified or cv-
1954 unqualified complete object type and I is a promoted integral type,
1955 there exist candidate operator functions of the form
1956 T* operator+(T*, I);
1957 T& operator[](T*, I);
1958 T* operator-(T*, I);
1959 T* operator+(I, T*);
1960 T& operator[](I, T*);
1962 15For every T, where T is a pointer to complete object type, there exist
1963 candidate operator functions of the form112)
1964 ptrdiff_t operator-(T, T);
1966 16For every pointer or enumeration type T, there exist candidate operator
1967 functions of the form
1968 bool operator<(T, T);
1969 bool operator>(T, T);
1970 bool operator<=(T, T);
1971 bool operator>=(T, T);
1972 bool operator==(T, T);
1973 bool operator!=(T, T);
1975 17For every pointer to member type T, there exist candidate operator
1976 functions of the form
1977 bool operator==(T, T);
1978 bool operator!=(T, T); */
1985 {
1988 }
2001 {
2004 }
2006 {
2009 }
2010 /* Fall through. */
2027 {
2030 }
2034 {
2037 }
2045 {
2048 }
2050 {
2053 }
2056 /* 18For every pair of promoted integral types L and R, there exist candi-
2057 date operator functions of the form
2058 LR operator%(L, R);
2059 LR operator&(L, R);
2060 LR operator^(L, R);
2061 LR operator|(L, R);
2062 L operator<<(L, R);
2063 L operator>>(L, R);
2064 where LR is the result of the usual arithmetic conversions between
2065 types L and R. */
2073 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2077 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2078 type, VQ is either volatile or empty, and R is a promoted arithmetic
2079 type, there exist candidate operator functions of the form
2080 VQ L& operator=(VQ L&, R);
2081 VQ L& operator*=(VQ L&, R);
2082 VQ L& operator/=(VQ L&, R);
2083 VQ L& operator+=(VQ L&, R);
2084 VQ L& operator-=(VQ L&, R);
2086 20For every pair T, VQ), where T is any type and VQ is either volatile
2087 or empty, there exist candidate operator functions of the form
2088 T*VQ& operator=(T*VQ&, T*);
2090 21For every pair T, VQ), where T is a pointer to member type and VQ is
2091 either volatile or empty, there exist candidate operator functions of
2092 the form
2093 VQ T& operator=(VQ T&, T);
2095 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2096 unqualified complete object type, VQ is either volatile or empty, and
2097 I is a promoted integral type, there exist candidate operator func-
2098 tions of the form
2099 T*VQ& operator+=(T*VQ&, I);
2100 T*VQ& operator-=(T*VQ&, I);
2102 23For every triple L, VQ, R), where L is an integral or enumeration
2103 type, VQ is either volatile or empty, and R is a promoted integral
2104 type, there exist candidate operator functions of the form
2106 VQ L& operator%=(VQ L&, R);
2107 VQ L& operator<<=(VQ L&, R);
2108 VQ L& operator>>=(VQ L&, R);
2109 VQ L& operator&=(VQ L&, R);
2110 VQ L& operator^=(VQ L&, R);
2111 VQ L& operator|=(VQ L&, R); */
2115 {
2119 {
2122 }
2135 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2148 {
2151 }
2156 }
2161 /* [over.built]
2163 For every pair of promoted arithmetic types L and R, there
2164 exist candidate operator functions of the form
2166 LR operator?(bool, L, R);
2168 where LR is the result of the usual arithmetic conversions
2169 between types L and R.
2171 For every type T, where T is a pointer or pointer-to-member
2172 type, there exist candidate operator functions of the form T
2173 operator?(bool, T, T); */
2177 /* That's OK. */
2180 /* Otherwise, the types should be pointers. */
2185 /* We don't check that the two types are the same; the logic
2186 below will actually create two candidates; one in which both
2187 parameter types are TYPE1, and one in which both parameter
2188 types are TYPE2. */
2193 }
2195 /* If we're dealing with two pointer types or two enumeral types,
2196 we need candidates for both of them. */
2205 {
2206 build_builtin_candidate
2208 build_builtin_candidate
2211 }
2213 build_builtin_candidate
2215 }
2217 tree
2219 {
2225 }
2227 /* There are three conditions of builtin candidates:
2229 1) bool-taking candidates. These are the same regardless of the input.
2230 2) pointer-pair taking candidates. These are generated for each type
2231 one of the input types converts to.
2232 3) arithmetic candidates. According to the standard, we should generate
2233 all of these, but I'm trying not to...
2235 Here we generate a superset of the possible candidates for this particular
2236 case. That is a subset of the full set the standard defines, plus some
2237 other cases which the standard disallows. add_builtin_candidate will
2238 filter out the invalid set. */
2240 static void
2244 {
2248 /* TYPES[i] is the set of possible builtin-operator parameter types
2249 we will consider for the Ith argument. These are represented as
2250 a TREE_LIST; the TREE_VALUE of each node is the potential
2251 parameter type. */
2255 {
2258 else
2260 }
2263 {
2264 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2265 and VQ is either volatile or empty, there exist candidate operator
2266 functions of the form
2267 VQ T& operator++(VQ T&); */
2277 /* 24There also exist candidate operator functions of the form
2278 bool operator!(bool);
2279 bool operator&&(bool, bool);
2280 bool operator||(bool, bool); */
2283 build_builtin_candidate
2290 build_builtin_candidate
2308 /* Fall through. */
2312 }
2317 {
2319 ;
2321 {
2322 tree convs;
2330 {
2337 }
2343 {
2356 {
2362 }
2366 }
2367 }
2368 else
2369 {
2375 {
2381 }
2383 }
2384 }
2386 /* Run through the possible parameter types of both arguments,
2387 creating candidates with those parameter types. */
2389 {
2392 add_builtin_candidate
2395 else
2396 add_builtin_candidate
2399 }
2400 }
2403 /* If TMPL can be successfully instantiated as indicated by
2404 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2406 TMPL is the template. EXPLICIT_TARGS are any explicit template
2407 arguments. ARGLIST is the arguments provided at the call-site.
2408 This does not change ARGLIST. The RETURN_TYPE is the desired type
2409 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2410 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2411 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2419 {
2424 tree first_arg_without_in_chrg;
2428 tree arg;
2431 tree fn;
2439 /* We don't do deduction on the in-charge parameter, the VTT
2440 parameter or 'this'. */
2442 {
2445 else
2447 }
2452 {
2455 else
2457 }
2465 {
2468 }
2472 {
2475 }
2479 args_without_in_chrg,
2480 nargs_without_in_chrg,
2490 /* In [class.copy]:
2492 A member function template is never instantiated to perform the
2493 copy of a class object to an object of its class type.
2495 It's a little unclear what this means; the standard explicitly
2496 does allow a template to be used to copy a class. For example,
2497 in:
2499 struct A {
2500 A(A&);
2501 template <class T> A(const T&);
2502 };
2503 const A f ();
2504 void g () { A a (f ()); }
2506 the member template will be used to make the copy. The section
2507 quoted above appears in the paragraph that forbids constructors
2508 whose only parameter is (a possibly cv-qualified variant of) the
2509 class type, and a logical interpretation is that the intent was
2510 to forbid the instantiation of member templates which would then
2511 have that form. */
2513 {
2516 ctype))
2518 }
2521 /* Aha, this is a conversion function. */
2524 else
2529 /* This situation can occur if a member template of a template
2530 class is specialized. Then, instantiate_template might return
2531 an instantiation of the specialization, in which case the
2532 DECL_TI_TEMPLATE field will point at the original
2533 specialization. For example:
2535 template <class T> struct S { template <class U> void f(U);
2536 template <> void f(int) {}; };
2537 S<double> sd;
2538 sd.f(3);
2540 Here, TMPL will be template <class U> S<double>::f(U).
2541 And, instantiate template will give us the specialization
2542 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2543 for this will point at template <class T> template <> S<T>::f(int),
2544 so that we can find the definition. For the purposes of
2545 overload resolution, however, we want the original TMPL. */
2547 else
2551 }
2559 unification_kind_t strict)
2560 {
2561 return
2566 }
2574 tree conversion_path)
2575 {
2576 return
2580 }
2582 /* The CANDS are the set of candidates that were considered for
2583 overload resolution. Return the set of viable candidates. If none
2584 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2585 is true if a candidate should be considered viable only if it is
2586 strictly viable. */
2592 {
2603 {
2606 {
2612 }
2613 else
2615 }
2618 }
2620 static bool
2622 {
2627 }
2629 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2630 words, it is about to become the "this" pointer for a member
2631 function call. Take the address of the object. */
2633 static tree
2635 {
2636 /* In a template, we are only concerned about the type of the
2637 expression, so we can take a shortcut. */
2642 }
2644 /* Returns true iff functions are equivalent. Equivalent functions are
2645 not '==' only if one is a function-local extern function or if
2646 both are extern "C". */
2650 {
2655 }
2657 /* Print information about one overload candidate CANDIDATE. MSGSTR
2658 is the text to print before the candidate itself.
2660 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2661 to have been run through gettext by the caller. This wart makes
2662 life simpler in print_z_candidates and for the translators. */
2664 static void
2666 {
2668 {
2678 else
2681 }
2686 else
2688 }
2690 static void
2692 {
2697 /* There may be duplicates in the set of candidates. We put off
2698 checking this condition as long as possible, since we have no way
2699 to eliminate duplicates from a set of functions in less than n^2
2700 time. Now we are about to emit an error message, so it is more
2701 permissible to go slowly. */
2703 {
2705 /* Skip builtin candidates and conversion functions. */
2710 {
2714 else
2716 }
2717 }
2725 {
2726 /* Indent successive candidates by the width of the translation
2727 of the above string. */
2734 do
2735 {
2738 }
2740 }
2741 }
2743 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2744 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2745 the result of the conversion function to convert it to the final
2746 desired type. Merge the two sequences into a single sequence,
2747 and return the merged sequence. */
2751 {
2756 /* Find the end of the second conversion sequence. */
2761 /* Replace the identity conversion with the user conversion
2762 sequence. */
2765 /* The entire sequence is a user-conversion sequence. */
2769 }
2771 /* Returns the best overload candidate to perform the requested
2772 conversion. This function is used for three the overloading situations
2773 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2774 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2775 per [dcl.init.ref], so we ignore temporary bindings. */
2779 {
2790 /* We represent conversion within a hierarchy using RVALUE_CONV and
2791 BASE_CONV, as specified by [over.best.ics]; these become plain
2792 constructor calls, as specified in [dcl.init]. */
2800 {
2805 {
2806 /* [class.conv.fct] A conversion function is never used to
2807 convert a (possibly cv-qualified) object to the (possibly
2808 cv-qualified) same object type (or a reference to it), to a
2809 (possibly cv-qualified) base class of that type (or a
2810 reference to it)... */
2811 }
2812 else
2814 }
2819 /* It's OK to bind a temporary for converting constructor arguments, but
2820 not in converting the return value of a conversion operator. */
2825 {
2831 {
2833 /* We still allow more conversions within an init-list. */
2835 /* But not for the copy ctor. */
2836 |LOOKUP_NO_COPY_CTOR_CONVERSION
2838 }
2839 else
2842 /* We should never try to call the abstract or base constructor
2843 from here. */
2846 }
2848 {
2859 flags,
2860 DEDUCE_CALL);
2861 else
2865 flags);
2868 {
2871 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2872 set, then this is copy-initialization. In that case, "The
2873 result of the call is then used to direct-initialize the
2874 object that is the destination of the copy-initialization."
2875 [dcl.init]
2877 We represent this in the conversion sequence with an
2878 rvalue conversion, which means a constructor call. */
2881 cand->second_conv
2883 }
2884 }
2890 {
2891 tree fns;
2894 /* If we are called to convert to a reference type, we are trying to
2895 find an lvalue binding, so don't even consider temporaries. If
2896 we don't find an lvalue binding, the caller will try again to
2897 look for a temporary binding. */
2902 {
2909 /* [over.match.funcs] For conversion functions, the function
2910 is considered to be a member of the class of the implicit
2911 object argument for the purpose of defining the type of
2912 the implicit object parameter.
2914 So we pass fromtype as CTYPE to add_*_candidate. */
2918 NULL_TREE,
2921 conversion_path,
2922 flags,
2923 DEDUCE_CONV);
2924 else
2928 conversion_path,
2929 flags);
2932 {
2933 conversion *ics
2939 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
2940 copy-initialization. In that case, "The result of the
2941 call is then used to direct-initialize the object that is
2942 the destination of the copy-initialization." [dcl.init]
2944 We represent this in the conversion sequence with an
2945 rvalue conversion, which means a constructor call. But
2946 don't add a second rvalue conversion if there's already
2947 one there. Which there really shouldn't be, but it's
2948 harmless since we'd add it here anyway. */
2959 }
2960 }
2961 }
2969 {
2971 {
2975 }
2982 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2983 ambiguous conversion is no worse than another user-defined
2984 conversion. */
2987 }
2989 /* Build the user conversion sequence. */
2990 conv = build_conv
2997 /* Remember that this was a list-initialization. */
3001 /* Combine it with the second conversion sequence. */
3009 }
3011 tree
3013 {
3018 {
3023 }
3025 }
3027 /* Do any initial processing on the arguments to a function call. */
3031 {
3033 tree arg;
3036 {
3040 {
3043 }
3046 }
3048 }
3050 /* Perform overload resolution on FN, which is called with the ARGS.
3052 Return the candidate function selected by overload resolution, or
3053 NULL if the event that overload resolution failed. In the case
3054 that overload resolution fails, *CANDIDATES will be the set of
3055 candidates considered, and ANY_VIABLE_P will be set to true or
3056 false to indicate whether or not any of the candidates were
3057 viable.
3059 The ARGS should already have gone through RESOLVE_ARGS before this
3060 function is called. */
3067 {
3075 /* Check FN. */
3082 {
3086 }
3088 /* Add the various candidate functions. */
3092 LOOKUP_NORMAL,
3093 candidates);
3101 }
3103 /* Return an expression for a call to FN (a namespace-scope function,
3104 or a static member function) with the ARGS. This may change
3105 ARGS. */
3107 tree
3109 tsubst_flags_t complain)
3110 {
3114 tree result;
3117 {
3121 }
3123 /* If this function was found without using argument dependent
3124 lookup, then we want to ignore any undeclared friend
3125 functions. */
3127 {
3132 {
3138 }
3139 }
3141 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3147 {
3149 {
3157 else
3162 }
3164 }
3165 else
3168 /* Free all the conversions we allocated. */
3172 }
3174 /* Build a call to a global operator new. FNNAME is the name of the
3175 operator (either "operator new" or "operator new[]") and ARGS are
3176 the arguments provided. This may change ARGS. *SIZE points to the
3177 total number of bytes required by the allocation, and is updated if
3178 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3179 be used. If this function determines that no cookie should be
3180 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3181 non-NULL, it will be set, upon return, to the allocation function
3182 called. */
3184 tree
3188 {
3189 tree fns;
3201 /* Based on:
3203 [expr.new]
3205 If this lookup fails to find the name, or if the allocated type
3206 is not a class type, the allocation function's name is looked
3207 up in the global scope.
3209 we disregard block-scope declarations of "operator new". */
3212 /* Figure out what function is being called. */
3215 /* If no suitable function could be found, issue an error message
3216 and give up. */
3218 {
3222 else
3228 }
3230 /* If a cookie is required, add some extra space. Whether
3231 or not a cookie is required cannot be determined until
3232 after we know which function was called. */
3234 {
3237 {
3238 /* In G++ 3.2, the check was implemented incorrectly; it
3239 looked at the placement expression, rather than the
3240 type of the function. */
3243 ptr_type_node))
3245 }
3246 else
3247 {
3248 tree arg_types;
3251 /* Skip the size_t parameter. */
3253 /* Check the remaining parameters (if any). */
3257 ptr_type_node))
3259 }
3260 /* If we need a cookie, adjust the number of bytes allocated. */
3262 {
3263 /* Update the total size. */
3265 /* Update the argument list to reflect the adjusted size. */
3267 }
3268 else
3270 }
3272 /* Tell our caller which function we decided to call. */
3276 /* Build the CALL_EXPR. */
3278 }
3280 /* Build a new call to operator(). This may change ARGS. */
3282 tree
3284 {
3298 {
3300 /* It's no good looking for an overloaded operator() on a
3301 pointer-to-member-function. */
3302 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3304 }
3307 {
3311 }
3312 else
3316 {
3320 }
3322 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3326 {
3331 {
3339 else
3340 add_function_candidate
3343 }
3344 }
3349 {
3361 {
3368 add_template_conv_candidate
3372 else
3376 }
3377 }
3381 {
3383 {
3387 }
3389 }
3390 else
3391 {
3394 {
3396 {
3400 }
3402 }
3403 /* Since cand->fn will be a type, not a function, for a conversion
3404 function, we must be careful not to unconditionally look at
3405 DECL_NAME here. */
3409 else
3410 {
3412 complain);
3415 }
3416 }
3418 /* Free all the conversions we allocated. */
3422 }
3424 static void
3427 {
3432 else
3436 {
3460 else
3464 }
3465 }
3467 /* Return the implicit conversion sequence that could be used to
3468 convert E1 to E2 in [expr.cond]. */
3472 {
3478 /* [expr.cond]
3480 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3481 implicitly converted (clause _conv_) to the type "reference to
3482 T2", subject to the constraint that in the conversion the
3483 reference must bind directly (_dcl.init.ref_) to E1. */
3485 {
3487 t1,
3488 e1,
3493 }
3495 /* [expr.cond]
3497 If E1 and E2 have class type, and the underlying class types are
3498 the same or one is a base class of the other: E1 can be converted
3499 to match E2 if the class of T2 is the same type as, or a base
3500 class of, the class of T1, and the cv-qualification of T2 is the
3501 same cv-qualification as, or a greater cv-qualification than, the
3502 cv-qualification of T1. If the conversion is applied, E1 is
3503 changed to an rvalue of type T2 that still refers to the original
3504 source class object (or the appropriate subobject thereof). */
3507 {
3509 {
3514 else
3517 }
3518 else
3520 }
3521 else
3522 /* [expr.cond]
3524 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3525 converted to the type that expression E2 would have if E2 were
3526 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3528 LOOKUP_IMPLICIT);
3529 }
3531 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3532 arguments to the conditional expression. */
3534 tree
3536 tsubst_flags_t complain)
3537 {
3538 tree arg2_type;
3539 tree arg3_type;
3547 /* As a G++ extension, the second argument to the conditional can be
3548 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3549 c'.) If the second operand is omitted, make sure it is
3550 calculated only once. */
3552 {
3557 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3560 else
3562 }
3564 /* [expr.cond]
3566 The first expression is implicitly converted to bool (clause
3567 _conv_). */
3570 /* If something has already gone wrong, just pass that fact up the
3571 tree. */
3577 /* [expr.cond]
3579 If either the second or the third operand has type (possibly
3580 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3581 array-to-pointer (_conv.array_), and function-to-pointer
3582 (_conv.func_) standard conversions are performed on the second
3583 and third operands. */
3587 {
3588 /* Do the conversions. We don't these for `void' type arguments
3589 since it can't have any effect and since decay_conversion
3590 does not handle that case gracefully. */
3598 /* [expr.cond]
3600 One of the following shall hold:
3602 --The second or the third operand (but not both) is a
3603 throw-expression (_except.throw_); the result is of the
3604 type of the other and is an rvalue.
3606 --Both the second and the third operands have type void; the
3607 result is of type void and is an rvalue.
3609 We must avoid calling force_rvalue for expressions of type
3610 "void" because it will complain that their value is being
3611 used. */
3614 {
3619 }
3622 {
3627 }
3630 else
3631 {
3633 {
3636 "is of type %<void%>, "
3637 "but the third operand is neither a throw-expression "
3639 else
3641 "is of type %<void%>, "
3642 "but the second operand is neither a throw-expression "
3644 }
3646 }
3650 }
3651 /* [expr.cond]
3653 Otherwise, if the second and third operand have different types,
3654 and either has (possibly cv-qualified) class type, an attempt is
3655 made to convert each of those operands to the type of the other. */
3658 {
3662 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3668 /* [expr.cond]
3670 If both can be converted, or one can be converted but the
3671 conversion is ambiguous, the program is ill-formed. If
3672 neither can be converted, the operands are left unchanged and
3673 further checking is performed as described below. If exactly
3674 one conversion is possible, that conversion is applied to the
3675 chosen operand and the converted operand is used in place of
3676 the original operand for the remainder of this section. */
3681 {
3685 }
3687 {
3691 /* Even if CONV2 is a valid conversion, the result of the
3692 conversion may be invalid. For example, if ARG3 has type
3693 "volatile X", and X does not have a copy constructor
3694 accepting a "volatile X&", then even if ARG2 can be
3695 converted to X, the conversion will fail. */
3698 }
3700 {
3706 }
3708 /* Free all the conversions we allocated. */
3714 /* If, after the conversion, both operands have class type,
3715 treat the cv-qualification of both operands as if it were the
3716 union of the cv-qualification of the operands.
3718 The standard is not clear about what to do in this
3719 circumstance. For example, if the first operand has type
3720 "const X" and the second operand has a user-defined
3721 conversion to "volatile X", what is the type of the second
3722 operand after this step? Making it be "const X" (matching
3723 the first operand) seems wrong, as that discards the
3724 qualification without actually performing a copy. Leaving it
3725 as "volatile X" seems wrong as that will result in the
3726 conditional expression failing altogether, even though,
3727 according to this step, the one operand could be converted to
3728 the type of the other. */
3736 }
3738 /* [expr.cond]
3740 If the second and third operands are lvalues and have the same
3741 type, the result is of that type and is an lvalue. */
3745 {
3748 }
3750 /* [expr.cond]
3752 Otherwise, the result is an rvalue. If the second and third
3753 operand do not have the same type, and either has (possibly
3754 cv-qualified) class type, overload resolution is used to
3755 determine the conversions (if any) to be applied to the operands
3756 (_over.match.oper_, _over.built_). */
3760 {
3765 /* Rearrange the arguments so that add_builtin_candidate only has
3766 to know about two args. In build_builtin_candidates, the
3767 arguments are unscrambled. */
3772 COND_EXPR,
3773 NOP_EXPR,
3775 args,
3776 LOOKUP_NORMAL);
3778 /* [expr.cond]
3780 If the overload resolution fails, the program is
3781 ill-formed. */
3784 {
3786 {
3789 }
3791 }
3794 {
3796 {
3799 }
3801 }
3803 /* [expr.cond]
3805 Otherwise, the conversions thus determined are applied, and
3806 the converted operands are used in place of the original
3807 operands for the remainder of this section. */
3814 }
3816 /* [expr.cond]
3818 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3819 and function-to-pointer (_conv.func_) standard conversions are
3820 performed on the second and third operands.
3822 We need to force the lvalue-to-rvalue conversion here for class types,
3823 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3824 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3825 regions. */
3838 /* [expr.cond]
3840 After those conversions, one of the following shall hold:
3842 --The second and third operands have the same type; the result is of
3843 that type. */
3846 /* [expr.cond]
3848 --The second and third operands have arithmetic or enumeration
3849 type; the usual arithmetic conversions are performed to bring
3850 them to a common type, and the result is of that type. */
3855 {
3856 /* In this case, there is always a common type. */
3858 arg3_type);
3862 {
3867 }
3873 {
3877 }
3881 }
3882 /* [expr.cond]
3884 --The second and third operands have pointer type, or one has
3885 pointer type and the other is a null pointer constant; pointer
3886 conversions (_conv.ptr_) and qualification conversions
3887 (_conv.qual_) are performed to bring them to their composite
3888 pointer type (_expr.rel_). The result is of the composite
3889 pointer type.
3891 --The second and third operands have pointer to member type, or
3892 one has pointer to member type and the other is a null pointer
3893 constant; pointer to member conversions (_conv.mem_) and
3894 qualification conversions (_conv.qual_) are performed to bring
3895 them to a common type, whose cv-qualification shall match the
3896 cv-qualification of either the second or the third operand.
3897 The result is of the common type. */
3905 {
3908 complain);
3913 }
3916 {
3921 }
3923 valid_operands:
3926 /* We can't use result_type below, as fold might have returned a
3927 throw_expr. */
3930 {
3931 /* Expand both sides into the same slot, hopefully the target of
3932 the ?: expression. We used to check for TARGET_EXPRs here,
3933 but now we sometimes wrap them in NOP_EXPRs so the test would
3934 fail. */
3937 /* If this expression is an rvalue, but might be mistaken for an
3938 lvalue, we must add a NON_LVALUE_EXPR. */
3940 }
3943 }
3945 /* OPERAND is an operand to an expression. Perform necessary steps
3946 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3947 returned. */
3949 static tree
3951 {
3953 {
3956 /* Make sure the template type is instantiated now. */
3958 }
3961 }
3963 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3964 OVERLOAD) to the CANDIDATES, returning an updated list of
3965 CANDIDATES. The ARGS are the arguments provided to the call,
3966 without any implicit object parameter. This may change ARGS. The
3967 EXPLICIT_TARGS are explicit template arguments provided.
3968 TEMPLATE_ONLY is true if only template functions should be
3969 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
3970 add_function_candidate. */
3972 static void
3978 {
3979 tree ctype;
3981 tree first_arg;
3984 /* Delay creating the implicit this parameter until it is needed. */
3989 {
3990 tree fn;
3991 tree fn_first_arg;
3995 /* Figure out which set of arguments to use. */
3997 {
3998 /* If this function is a non-static member, prepend the implicit
3999 object parameter. */
4001 {
4003 tree arg;
4009 }
4014 }
4015 else
4016 {
4017 /* Otherwise, just use the list of arguments provided. */
4020 }
4024 fn,
4025 ctype,
4026 explicit_targs,
4027 fn_first_arg,
4028 fn_args,
4029 NULL_TREE,
4030 access_path,
4031 conversion_path,
4032 flags,
4033 DEDUCE_CALL);
4036 fn,
4037 ctype,
4038 fn_first_arg,
4039 fn_args,
4040 access_path,
4041 conversion_path,
4042 flags);
4044 }
4045 }
4047 /* Even unsigned enum types promote to signed int. We don't want to
4048 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4049 original argument and ARG is the argument after any conversions
4050 have been applied. We set TREE_NO_WARNING if we have added a cast
4051 from an unsigned enum type to a signed integer type. */
4053 static void
4055 {
4064 }
4066 tree
4069 {
4075 tree fnname;
4093 {
4097 }
4098 else
4104 {
4109 /* Use build_op_new_call and build_op_delete_call instead. */
4113 /* Use build_op_call instead. */
4120 /* These are saved for the sake of warn_logical_operator. */
4126 }
4132 {
4139 }
4154 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4157 /* Add namespace-scope operators to the list of functions to
4158 consider. */
4162 /* Add class-member operators to the candidate set. */
4164 {
4165 tree fns;
4169 {
4172 }
4179 }
4181 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
4182 to know about two args; a builtin candidate will always have a first
4183 parameter of type bool. We'll handle that in
4184 build_builtin_candidate. */
4186 {
4190 }
4191 else
4192 {
4196 }
4201 {
4204 /* For these, the built-in candidates set is empty
4205 [over.match.oper]/3. We don't want non-strict matches
4206 because exact matches are always possible with built-in
4207 operators. The built-in candidate set for COMPONENT_REF
4208 would be empty too, but since there are no such built-in
4209 operators, we accept non-strict matches for them. */
4216 }
4220 {
4222 {
4225 /* Don't try anything fancy if we're not allowed to produce
4226 errors. */
4230 /* Look for an `operator++ (int)'. If they didn't have
4231 one, then we fall back to the old way of doing things. */
4235 fnname,
4239 else
4245 /* The caller will deal with these. */
4255 {
4256 /* If one of the arguments of the operator represents
4257 an invalid use of member function pointer, try to report
4258 a meaningful error ... */
4263 else
4264 {
4265 /* ... Otherwise, report the more generic
4266 "no matching operator found" error */
4269 }
4270 }
4273 }
4274 }
4275 else
4276 {
4279 {
4281 {
4284 }
4286 }
4288 {
4294 else
4296 }
4297 else
4298 {
4299 /* Give any warnings we noticed during overload resolution. */
4301 {
4305 }
4307 /* Check for comparison of different enum types. */
4309 {
4321 {
4325 }
4329 }
4331 /* We need to strip any leading REF_BIND so that bitfields
4332 don't cause errors. This should not remove any important
4333 conversions, because builtins don't apply to class
4334 objects directly. */
4341 {
4342 /* We need to call warn_logical_operator before
4343 converting arg2 to a boolean_type. */
4353 }
4355 {
4360 }
4362 }
4363 }
4365 user_defined_result_ready:
4367 /* Free all the conversions we allocated. */
4373 builtin:
4379 {
4392 /* Fall through. */
4433 complain),
4434 arg2);
4436 /* The caller will deal with these. */
4444 }
4446 }
4448 /* Build a call to operator delete. This has to be handled very specially,
4449 because the restrictions on what signatures match are different from all
4450 other call instances. For a normal delete, only a delete taking (void *)
4451 or (void *, size_t) is accepted. For a placement delete, only an exact
4452 match with the placement new is accepted.
4454 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4455 ADDR is the pointer to be deleted.
4456 SIZE is the size of the memory block to be deleted.
4457 GLOBAL_P is true if the delete-expression should not consider
4458 class-specific delete operators.
4459 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4461 If this call to "operator delete" is being generated as part to
4462 deallocate memory allocated via a new-expression (as per [expr.new]
4463 which requires that if the initialization throws an exception then
4464 we call a deallocation function), then ALLOC_FN is the allocation
4465 function. */
4467 tree
4470 tree alloc_fn)
4471 {
4486 /* In [class.free]
4488 If the result of the lookup is ambiguous or inaccessible, or if
4489 the lookup selects a placement deallocation function, the
4490 program is ill-formed.
4492 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4493 {
4497 }
4498 else
4504 /* Strip const and volatile from addr. */
4508 {
4509 /* Get the parameter types for the allocation function that is
4510 being called. */
4513 }
4514 else
4515 {
4516 /* First try it without the size argument. */
4518 }
4520 /* We make two tries at finding a matching `operator delete'. On
4521 the first pass, we look for a one-operator (or placement)
4522 operator delete. If we're not doing placement delete, then on
4523 the second pass we look for a two-argument delete. */
4525 {
4526 /* Go through the `operator delete' functions looking for one
4527 with a matching type. */
4529 fn;
4531 {
4532 tree t;
4534 /* The first argument must be "void *". */
4539 /* On the first pass, check the rest of the arguments. */
4541 {
4544 {
4549 }
4552 }
4553 /* On the second pass, look for a function with exactly two
4554 arguments: "void *" and "size_t". */
4556 /* For "operator delete(void *, ...)" there will be
4557 no second argument, but we will not get an exact
4558 match above. */
4559 && t
4563 }
4565 /* If we found a match, we're done. */
4568 }
4570 /* If we have a matching function, call it. */
4572 {
4573 /* Make sure we have the actual function, and not an
4574 OVERLOAD. */
4577 /* If the FN is a member function, make sure that it is
4578 accessible. */
4583 {
4584 /* The placement args might not be suitable for overload
4585 resolution at this point, so build the call directly. */
4594 }
4595 else
4596 {
4597 tree ret;
4605 }
4606 }
4608 /* [expr.new]
4610 If no unambiguous matching deallocation function can be found,
4611 propagating the exception does not cause the object's memory to
4612 be freed. */
4614 {
4617 alloc_fn);
4619 }
4624 }
4626 /* If the current scope isn't allowed to access DECL along
4627 BASETYPE_PATH, give an error. The most derived class in
4628 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4629 the declaration to use in the error diagnostic. */
4631 bool
4633 {
4637 {
4642 else
4646 }
4649 }
4651 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4652 bitwise or of LOOKUP_* values. If any errors are warnings are
4653 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4654 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4655 to NULL. */
4657 static tree
4660 {
4673 else
4676 }
4678 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4679 EXPR is implicitly converted to type TOTYPE.
4680 FN and ARGNUM are used for diagnostics. */
4682 static void
4684 {
4687 /* Issue warnings about peculiar, but valid, uses of NULL. */
4689 {
4693 else
4695 }
4697 /* Issue warnings if "false" is converted to a NULL pointer */
4702 }
4704 /* Perform the conversions in CONVS on the expression EXPR. FN and
4705 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4706 indicates the `this' argument of a method. INNER is nonzero when
4707 being called to continue a conversion chain. It is negative when a
4708 reference binding will be applied, positive otherwise. If
4709 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4710 conversions will be emitted if appropriate. If C_CAST_P is true,
4711 this conversion is coming from a C-style cast; in that case,
4712 conversions to inaccessible bases are permitted. */
4714 static tree
4718 {
4720 diagnostic_t diag_kind;
4730 {
4733 /* Give a helpful error if this is bad because of excess braces. */
4741 {
4743 {
4747 complain);
4749 }
4754 complain);
4757 }
4759 {
4763 }
4764 else
4768 }
4774 {
4776 {
4781 /* When converting from an init list we consider explicit
4782 constructors, but actually trying to call one is an error. */
4784 {
4788 else
4790 }
4792 /* Set user_conv_p on the argument conversions, so rvalue/base
4793 handling knows not to allow any more UDCs. */
4799 /* If this is a constructor or a function returning an aggr type,
4800 we need to build up a TARGET_EXPR. */
4802 {
4805 /* Remember that this was list-initialization. */
4808 }
4811 }
4814 {
4820 else
4822 }
4826 /* Convert a constant to its underlying value, unless we are
4827 about to bind it to a reference, in which case we need to
4828 leave it as an lvalue. */
4830 {
4833 /* If __null has been converted to an integer type, we do not
4834 want to warn about uses of EXPR as an integer, rather than
4835 as a pointer. */
4837 }
4840 /* Call build_user_type_conversion again for the error. */
4841 return build_user_type_conversion
4845 {
4846 /* Conversion to std::initializer_list<T>. */
4854 /* Convert all the elements. */
4856 {
4863 }
4864 /* Build up the array. */
4865 elttype = cp_build_qualified_type
4873 /* Call the private constructor. */
4875 new_ctor = build_special_member_call
4880 }
4887 };
4892 c_cast_p,
4893 complain);
4898 {
4903 /* Else fall through. */
4906 {
4907 /* We are going to bind a reference directly to a base-class
4908 subobject of EXPR. */
4909 /* Build an expression for `*((base*) &expr)'. */
4915 }
4917 /* Copy-initialization where the cv-unqualified version of the source
4918 type is the same class as, or a derived class of, the class of the
4919 destination [is treated as direct-initialization]. [dcl.init] */
4922 /* This conversion is being done in the context of a user-defined
4923 conversion (i.e. the second step of copy-initialization), so
4924 don't allow any more. */
4928 {
4934 }
4938 {
4941 /* If necessary, create a temporary.
4943 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
4944 that need temporaries, even when their types are reference
4945 compatible with the type of reference being bound, so the
4946 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
4947 doesn't fail. */
4951 {
4957 {
4959 {
4960 /* If the reference is volatile or non-const, we
4961 cannot create a temporary. */
4968 else
4970 }
4972 }
4973 /* If the source is a packed field, and we must use a copy
4974 constructor, then building the target expr will require
4975 binding the field to the reference parameter to the
4976 copy constructor, and we'll end up with an infinite
4977 loop. If we can use a bitwise copy, then we'll be
4978 OK. */
4982 {
4987 }
4989 {
4992 }
4994 }
4996 /* Take the address of the thing to which we will bind the
4997 reference. */
5002 /* Convert it to a pointer to the type referred to by the
5003 reference. This will adjust the pointer if a derived to
5004 base conversion is being performed. */
5006 expr);
5007 /* Convert the pointer to the desired reference type. */
5009 }
5015 /* Warn about deprecated conversion if appropriate. */
5027 c_cast_p);
5031 }
5038 else
5042 }
5044 /* ARG is being passed to a varargs function. Perform any conversions
5045 required. Return the converted value. */
5047 tree
5049 {
5050 /* [expr.call]
5052 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5053 standard conversions are performed. */
5055 /* [expr.call]
5057 If the argument has integral or enumeration type that is subject
5058 to the integral promotions (_conv.prom_), or a floating point
5059 type that is subject to the floating point promotion
5060 (_conv.fpprom_), the value of the argument is converted to the
5061 promoted type before the call. */
5074 {
5075 /* [expr.call] 5.2.2/7:
5076 Passing a potentially-evaluated argument of class type (Clause 9)
5077 with a non-trivial copy constructor or a non-trivial destructor
5078 with no corresponding parameter is conditionally-supported, with
5079 implementation-defined semantics.
5081 We used to just warn here and do a bitwise copy, but now
5082 cp_expr_size will abort if we try to do that.
5084 If the call appears in the context of a sizeof expression,
5085 it is not potentially-evaluated. */
5089 }
5092 }
5094 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5096 tree
5098 {
5110 {
5111 /* Remove reference types so we don't ICE later on. */
5113 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5119 }
5122 }
5124 /* TYPE has been given to va_arg. Apply the default conversions which
5125 would have happened when passed via ellipsis. Return the promoted
5126 type, or the passed type if there is no change. */
5128 tree
5130 {
5131 tree promote;
5133 /* Perform the array-to-pointer and function-to-pointer
5134 conversions. */
5142 }
5144 /* ARG is a default argument expression being passed to a parameter of
5145 the indicated TYPE, which is a parameter to FN. Do any required
5146 conversions. Return the converted value. */
5150 tree
5152 {
5154 tree t;
5156 /* If the ARG is an unparsed default argument expression, the
5157 conversion cannot be performed. */
5159 {
5164 }
5166 /* Detect recursion. */
5169 {
5172 }
5178 /* Due to:
5180 [dcl.fct.default]
5182 The names in the expression are bound, and the semantic
5183 constraints are checked, at the point where the default
5184 expressions appears.
5186 we must not perform access checks here. */
5190 {
5194 tf_warning_or_error);
5195 }
5196 else
5197 {
5198 /* We must make a copy of ARG, in case subsequent processing
5199 alters any part of it. For example, during gimplification a
5200 cast of the form (T) &X::f (where "f" is a member function)
5201 will lead to replacing the PTRMEM_CST for &X::f with a
5202 VAR_DECL. We can avoid the copy for constants, since they
5203 are never modified in place. */
5208 tf_warning_or_error);
5210 }
5216 }
5218 /* Returns the type which will really be used for passing an argument of
5219 type TYPE. */
5221 tree
5223 {
5224 /* Pass classes with copy ctors by invisible reference. */
5226 {
5228 /* There are no other pointers to this temporary. */
5230 }
5239 }
5241 /* Actually perform the appropriate conversion. */
5243 tree
5245 {
5246 tree bitfield_type;
5248 /* If VAL is a bitfield, then -- since it has already been converted
5249 to TYPE -- it cannot have a precision greater than TYPE.
5251 If it has a smaller precision, we must widen it here. For
5252 example, passing "int f:3;" to a function expecting an "int" will
5253 not result in any conversion before this point.
5255 If the precision is the same we must not risk widening. For
5256 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5257 often have type "int", even though the C++ type for the field is
5258 "long long". If the value is being passed to a function
5259 expecting an "int", then no conversions will be required. But,
5260 if we call convert_bitfield_to_declared_type, the bitfield will
5261 be converted to "long long". */
5268 ;
5269 /* Pass classes with copy ctors by invisible reference. */
5279 {
5288 }
5290 }
5292 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5293 which no conversions at all should be done. This is true for some
5294 builtins which don't act like normal functions. */
5296 static bool
5298 {
5301 {
5311 }
5314 }
5316 /* Subroutine of the various build_*_call functions. Overload resolution
5317 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5318 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5319 bitmask of various LOOKUP_* flags which apply to the call itself. */
5321 static tree
5323 {
5331 tree val;
5340 /* In a template, there is no need to perform all of the work that
5341 is normally done. We are only interested in the type of the call
5342 expression, i.e., the return type of the function. Any semantic
5343 errors will be deferred until the template is instantiated. */
5345 {
5346 tree expr;
5347 tree return_type;
5355 else
5356 {
5359 tree arg;
5367 }
5369 argarray);
5375 }
5377 /* Give any warnings we noticed during overload resolution. */
5379 {
5383 }
5385 /* Make =delete work with SFINAE. */
5390 {
5391 /* If FN is a template function, two cases must be considered.
5392 For example:
5394 struct A {
5395 protected:
5396 template <class T> void f();
5397 };
5398 template <class T> struct B {
5399 protected:
5400 void g();
5401 };
5402 struct C : A, B<int> {
5403 using A::f; // #1
5404 using B<int>::g; // #2
5405 };
5407 In case #1 where `A::f' is a member template, DECL_ACCESS is
5408 recorded in the primary template but not in its specialization.
5409 We check access of FN using its primary template.
5411 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5412 because it is a member of class template B, DECL_ACCESS is
5413 recorded in the specialization `B<int>::g'. We cannot use its
5414 primary template because `B<T>::g' and `B<int>::g' may have
5415 different access. */
5420 else
5422 }
5424 /* Find maximum size of vector to hold converted arguments. */
5431 /* The implicit parameters to a constructor are not considered by overload
5432 resolution, and must be of the proper type. */
5434 {
5436 {
5439 }
5440 else
5441 {
5444 }
5446 /* We should never try to call the abstract constructor. */
5450 {
5454 }
5455 }
5456 /* Bypass access control for 'this' parameter. */
5458 {
5461 ? first_arg
5464 tree converted_arg;
5465 tree base_binfo;
5468 {
5472 else
5474 }
5476 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5477 X is called for an object that is not of type X, or of a type
5478 derived from X, the behavior is undefined.
5480 So we can assume that anything passed as 'this' is non-null, and
5481 optimize accordingly. */
5483 /* Convert to the base in which the function was declared. */
5486 arg,
5489 /* Check that the base class is accessible. */
5495 /* If fn was found by a using declaration, the conversion path
5496 will be to the derived class, not the base declaring fn. We
5497 must convert from derived to base. */
5507 else
5511 }
5516 {
5521 /* Don't make a copy here if build_call is going to. */
5527 val = convert_like_with_context
5529 complain);
5534 else
5536 }
5538 /* Default arguments */
5543 /* Ellipsis */
5545 {
5549 else
5552 }
5560 /* Avoid actually calling copy constructors and copy assignment operators,
5561 if possible. */
5568 {
5569 tree targ;
5571 tree fa;
5573 /* Pull out the real argument, disregarding const-correctness. */
5579 {
5584 }
5585 else
5590 else
5595 {
5596 /* Copy-list-initialization doesn't require the copy constructor
5597 to be defined. */
5598 }
5599 /* [class.copy]: the copy constructor is implicitly defined even if
5600 the implementation elided its use. */
5602 {
5605 }
5607 /* If we're creating a temp and we already have one, don't create a
5608 new one. If we're not creating a temp but we get one, use
5609 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5610 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5611 temp or an INIT_EXPR otherwise. */
5616 {
5621 }
5625 {
5627 complain));
5631 }
5632 }
5636 {
5637 tree to = stabilize_reference
5644 {
5647 }
5648 else
5649 {
5650 /* We must only copy the non-tail padding parts.
5651 Use __builtin_memcpy for the bitwise copy.
5652 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5653 instead of an explicit call to memcpy. */
5663 {
5664 /* If we can't be sure about pointer alignment, a call
5665 to __builtin_memcpy is expanded as a call to memcpy, which
5666 is invalid with identical args. Otherwise it is
5667 expanded as a block move, which should be safe. */
5671 }
5680 }
5683 }
5689 {
5690 tree t;
5696 /* Warn about deprecated virtual functions now, since we're about
5697 to throw away the decl. */
5707 else
5710 }
5711 else
5715 }
5717 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5718 This function performs no overload resolution, conversion, or other
5719 high-level operations. */
5721 tree
5723 {
5724 tree fndecl;
5728 /* If this call might throw an exception, note that fact. */
5735 /* Check that arguments to builtin functions match the expectations. */
5742 /* Some built-in function calls will be evaluated at compile-time in
5743 fold (). */
5756 }
5760 /* Make an expression which yields the address of the Java interface
5761 method FN. This is achieved by generating a call to libjava's
5762 _Jv_LookupInterfaceMethodIdx(). */
5764 static tree
5766 {
5772 {
5777 endlink)));
5778 java_iface_lookup_fn
5782 }
5784 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5785 This is the first entry in the vtable. */
5787 tf_warning_or_error),
5788 integer_zero_node);
5790 /* Get the java.lang.Class pointer for the interface being called. */
5795 {
5797 iface);
5799 }
5803 /* Determine the itable index of FN. */
5806 {
5811 i++;
5812 }
5817 java_iface_lookup_fn);
5820 }
5822 /* Returns the value to use for the in-charge parameter when making a
5823 call to a function with the indicated NAME.
5825 FIXME:Can't we find a neater way to do this mapping? */
5827 tree
5829 {
5840 /* This function should only be called with one of the names listed
5841 above. */
5844 }
5846 /* Build a call to a constructor, destructor, or an assignment
5847 operator for INSTANCE, an expression with class type. NAME
5848 indicates the special member function to call; *ARGS are the
5849 arguments. ARGS may be NULL. This may change ARGS. BINFO
5850 indicates the base of INSTANCE that is to be passed as the `this'
5851 parameter to the member function called.
5853 FLAGS are the LOOKUP_* flags to use when processing the call.
5855 If NAME indicates a complete object constructor, INSTANCE may be
5856 NULL_TREE. In this case, the caller will call build_cplus_new to
5857 store the newly constructed object into a VAR_DECL. */
5859 tree
5862 {
5863 tree fns;
5864 /* The type of the subobject to be constructed or destroyed. */
5865 tree class_type;
5867 tree ret;
5876 {
5877 /* Resolve the name. */
5882 }
5888 /* Handle the special case where INSTANCE is NULL_TREE. */
5890 {
5893 }
5894 else
5895 {
5901 /* Convert to the base class, if necessary. */
5904 {
5906 /* For constructors and destructors, either the base is
5907 non-virtual, or it is virtual but we are doing the
5908 conversion from a constructor or destructor for the
5909 complete object. In either case, we can convert
5910 statically. */
5912 else
5913 /* However, for assignment operators, we must convert
5914 dynamically if the base is virtual. */
5917 }
5918 }
5924 /* When making a call to a constructor or destructor for a subobject
5925 that uses virtual base classes, pass down a pointer to a VTT for
5926 the subobject. */
5930 {
5931 tree vtt;
5932 tree sub_vtt;
5934 /* If the current function is a complete object constructor
5935 or destructor, then we fetch the VTT directly.
5936 Otherwise, we look it up using the VTT we were given. */
5942 current_vtt_parm,
5943 vtt);
5949 {
5952 }
5955 }
5960 complain);
5966 }
5968 /* Return the NAME, as a C string. The NAME indicates a function that
5969 is a member of TYPE. *FREE_P is set to true if the caller must
5970 free the memory returned.
5972 Rather than go through all of this, we should simply set the names
5973 of constructors and destructors appropriately, and dispense with
5974 ctor_identifier, dtor_identifier, etc. */
5978 {
5981 /* Assume that we will not allocate memory. */
5983 /* Constructors and destructors are special. */
5985 {
5986 pretty_name
5988 /* For a destructor, add the '~'. */
5992 {
5994 /* Remember that we need to free the memory allocated. */
5996 }
5997 }
5999 {
6002 TFF_PLAIN_IDENTIFIER),
6003 NULL);
6004 /* Remember that we need to free the memory allocated. */
6006 }
6007 else
6011 }
6013 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6014 be set, upon return, to the function called. ARGS may be NULL.
6015 This may change ARGS. */
6017 tree
6021 {
6025 tree access_binfo;
6026 tree optype;
6028 tree instance_ptr;
6029 tree name;
6032 tree call;
6033 tree fn;
6034 tree class_type;
6037 tree orig_instance;
6038 tree orig_fns;
6044 /* We don't know what function we're going to call, yet. */
6053 {
6057 }
6062 /* Dismantle the baselink to collect all the information we need. */
6069 {
6073 }
6084 {
6089 }
6091 /* Figure out whether to skip the first argument for the error
6092 message we will display to users if an error occurs. We don't
6093 want to display any compiler-generated arguments. The "this"
6094 pointer hasn't been added yet. However, we must remove the VTT
6095 pointer if this is a call to a base-class constructor or
6096 destructor. */
6100 {
6101 /* Callers should explicitly indicate whether they want to construct
6102 the complete object or just the part without virtual bases. */
6104 /* Similarly for destructors. */
6106 /* Remove the VTT pointer, if present. */
6110 }
6112 /* Process the argument list. */
6114 {
6118 }
6122 /* It's OK to call destructors and constructors on cv-qualified objects.
6123 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6124 necessary. */
6127 {
6131 }
6135 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6136 initializer, not T({ }). If the type doesn't have a list ctor,
6137 break apart the list into separate ctor args. */
6142 {
6145 }
6150 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6154 {
6156 tree this_first_arg;
6158 /* We can end up here for copy-init of same or base class. */
6165 else
6169 /* A member template. */
6171 class_type,
6172 explicit_targs,
6173 this_first_arg,
6175 optype,
6176 access_binfo,
6177 conversion_path,
6178 flags,
6179 DEDUCE_CALL);
6182 class_type,
6183 this_first_arg,
6185 access_binfo,
6186 conversion_path,
6187 flags);
6188 }
6192 {
6194 {
6197 else
6198 {
6201 tree arglist;
6212 }
6214 }
6216 }
6217 else
6218 {
6221 {
6224 tree arglist;
6227 {
6233 arglist);
6237 }
6239 }
6240 else
6241 {
6250 /* This is not an error, it is runtime undefined
6251 behavior. */
6253 "abstract virtual %q#D called from constructor"
6255 fn);
6259 {
6262 fn);
6264 }
6265 else
6266 {
6270 /* Now we know what function is being called. */
6273 /* Build the actual CALL_EXPR. */
6275 /* In an expression of the form `a->f()' where `f' turns
6276 out to be a static member function, `a' is
6277 none-the-less evaluated. */
6286 /* An explicit call of the form "x->~X()" has type
6287 "void". However, on platforms where destructors
6288 return "this" (i.e., those where
6289 targetm.cxx.cdtor_returns_this is true), such calls
6290 will appear to have a return value of pointer type
6291 to the low-level call machinery. We do not want to
6292 change the low-level machinery, since we want to be
6293 able to optimize "delete f()" on such platforms as
6294 "operator delete(~X(f()))" (rather than generating
6295 "t = f(), ~X(t), operator delete (t)"). */
6297 }
6298 }
6299 }
6302 {
6308 {
6311 }
6314 call = (build_min_non_dep_call_vec
6318 orig_args));
6322 }
6324 /* Free all the conversions we allocated. */
6331 }
6333 /* Returns true iff standard conversion sequence ICS1 is a proper
6334 subsequence of ICS2. */
6336 static bool
6338 {
6339 /* We can assume that a conversion of the same code
6340 between the same types indicates a subsequence since we only get
6341 here if the types we are converting from are the same. */
6348 {
6356 /* At this point, ICS1 cannot be a proper subsequence of
6357 ICS2. We can get a USER_CONV when we are comparing the
6358 second standard conversion sequence of two user conversion
6359 sequences. */
6369 }
6370 }
6372 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6373 be any _TYPE nodes. */
6375 bool
6377 {
6381 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6382 considers every class derived from itself. */
6385 }
6387 /* We build the ICS for an implicit object parameter as a pointer
6388 conversion sequence. However, such a sequence should be compared
6389 as if it were a reference conversion sequence. If ICS is the
6390 implicit conversion sequence for an implicit object parameter,
6391 modify it accordingly. */
6393 static void
6395 {
6397 {
6398 /* [over.match.funcs]
6400 For non-static member functions, the type of the
6401 implicit object parameter is "reference to cv X"
6402 where X is the class of which the function is a
6403 member and cv is the cv-qualification on the member
6404 function declaration. */
6406 tree reference_type;
6408 /* The `this' parameter is a pointer to a class type. Make the
6409 implicit conversion talk about a reference to that same class
6410 type. */
6423 }
6424 }
6426 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6427 and return the initial reference binding conversion. Otherwise,
6428 leave *ICS unchanged and return NULL. */
6432 {
6434 {
6440 }
6443 }
6445 /* Compare two implicit conversion sequences according to the rules set out in
6446 [over.ics.rank]. Return values:
6448 1: ics1 is better than ics2
6449 -1: ics2 is better than ics1
6450 0: ics1 and ics2 are indistinguishable */
6452 static int
6454 {
6455 tree from_type1;
6456 tree from_type2;
6457 tree to_type1;
6458 tree to_type2;
6465 /* REF_BINDING is nonzero if the result of the conversion sequence
6466 is a reference type. In that case REF_CONV is the reference
6467 binding conversion. */
6471 /* Handle implicit object parameters. */
6475 /* Handle reference parameters. */
6479 /* [over.ics.rank]
6481 When comparing the basic forms of implicit conversion sequences (as
6482 defined in _over.best.ics_)
6484 --a standard conversion sequence (_over.ics.scs_) is a better
6485 conversion sequence than a user-defined conversion sequence
6486 or an ellipsis conversion sequence, and
6488 --a user-defined conversion sequence (_over.ics.user_) is a
6489 better conversion sequence than an ellipsis conversion sequence
6490 (_over.ics.ellipsis_). */
6500 {
6501 /* XXX Isn't this an extension? */
6502 /* Both ICS are bad. We try to make a decision based on what
6503 would have happened if they'd been good. */
6511 /* We couldn't make up our minds; try to figure it out below. */
6512 }
6515 /* Both conversions are ellipsis conversions. */
6518 /* User-defined conversion sequence U1 is a better conversion sequence
6519 than another user-defined conversion sequence U2 if they contain the
6520 same user-defined conversion operator or constructor and if the sec-
6521 ond standard conversion sequence of U1 is better than the second
6522 standard conversion sequence of U2. */
6525 {
6536 /* Conversion to std::initializer_list is better than other
6537 user-defined conversions. */
6540 {
6545 else
6547 }
6552 /* We can just fall through here, after setting up
6553 FROM_TYPE1 and FROM_TYPE2. */
6556 }
6557 else
6558 {
6562 /* We're dealing with two standard conversion sequences.
6564 [over.ics.rank]
6566 Standard conversion sequence S1 is a better conversion
6567 sequence than standard conversion sequence S2 if
6569 --S1 is a proper subsequence of S2 (comparing the conversion
6570 sequences in the canonical form defined by _over.ics.scs_,
6571 excluding any Lvalue Transformation; the identity
6572 conversion sequence is considered to be a subsequence of
6573 any non-identity conversion sequence */
6584 }
6586 /* One sequence can only be a subsequence of the other if they start with
6587 the same type. They can start with different types when comparing the
6588 second standard conversion sequence in two user-defined conversion
6589 sequences. */
6591 {
6596 }
6598 /* [over.ics.rank]
6600 Or, if not that,
6602 --the rank of S1 is better than the rank of S2 (by the rules
6603 defined below):
6605 Standard conversion sequences are ordered by their ranks: an Exact
6606 Match is a better conversion than a Promotion, which is a better
6607 conversion than a Conversion.
6609 Two conversion sequences with the same rank are indistinguishable
6610 unless one of the following rules applies:
6612 --A conversion that is not a conversion of a pointer, or pointer
6613 to member, to bool is better than another conversion that is such
6614 a conversion.
6616 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
6617 so that we do not have to check it explicitly. */
6626 /* A conversion from scalar arithmetic type to complex is worse than a
6627 conversion between scalar arithmetic types. */
6634 {
6637 else
6639 }
6645 {
6650 }
6651 /* The rules for pointers to members A::* are just like the rules
6652 for pointers A*, except opposite: if B is derived from A then
6653 A::* converts to B::*, not vice versa. For that reason, we
6654 switch the from_ and to_ variables here. */
6661 {
6666 }
6671 {
6672 /* This was one of the pointer or pointer-like conversions.
6674 [over.ics.rank]
6676 --If class B is derived directly or indirectly from class A,
6677 conversion of B* to A* is better than conversion of B* to
6678 void*, and conversion of A* to void* is better than
6679 conversion of B* to void*. */
6682 {
6684 deref_from_type2))
6687 deref_from_type1))
6689 }
6692 {
6694 {
6696 {
6698 deref_to_type1))
6700 }
6701 /* We know that DEREF_TO_TYPE1 is `void' here. */
6703 deref_to_type2))
6705 }
6706 }
6709 {
6710 /* [over.ics.rank]
6712 --If class B is derived directly or indirectly from class A
6713 and class C is derived directly or indirectly from B,
6715 --conversion of C* to B* is better than conversion of C* to
6716 A*,
6718 --conversion of B* to A* is better than conversion of C* to
6719 A* */
6721 {
6723 deref_to_type2))
6726 deref_to_type1))
6728 }
6730 {
6732 deref_from_type1))
6735 deref_from_type2))
6737 }
6738 }
6739 }
6742 {
6745 /* [over.ics.rank]
6747 --binding of an expression of type C to a reference of type
6748 B& is better than binding an expression of type C to a
6749 reference of type A&
6751 --conversion of C to B is better than conversion of C to A, */
6754 {
6759 }
6760 }
6763 {
6766 /* [over.ics.rank]
6768 --binding of an expression of type B to a reference of type
6769 A& is better than binding an expression of type C to a
6770 reference of type A&,
6772 --conversion of B to A is better than conversion of C to A */
6775 {
6780 }
6781 }
6783 /* [over.ics.rank]
6785 --S1 and S2 differ only in their qualification conversion and yield
6786 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6787 qualification signature of type T1 is a proper subset of the cv-
6788 qualification signature of type T2 */
6792 {
6796 }
6798 /* [over.ics.rank]
6800 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6801 to an implicit object parameter, and either S1 binds an lvalue reference
6802 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6803 reference to an rvalue and S2 binds an lvalue reference
6804 (C++0x draft standard, 13.3.3.2)
6806 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6807 types to which the references refer are the same type except for
6808 top-level cv-qualifiers, and the type to which the reference
6809 initialized by S2 refers is more cv-qualified than the type to
6810 which the reference initialized by S1 refers */
6813 {
6817 {
6822 }
6827 }
6829 /* Neither conversion sequence is better than the other. */
6831 }
6833 /* The source type for this standard conversion sequence. */
6835 static tree
6837 {
6839 {
6844 }
6846 }
6848 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6849 a pointer to LOSER and re-running joust to produce the warning if WINNER
6850 is actually used. */
6852 static void
6854 {
6860 }
6862 /* Compare two candidates for overloading as described in
6863 [over.match.best]. Return values:
6865 1: cand1 is better than cand2
6866 -1: cand2 is better than cand1
6867 0: cand1 and cand2 are indistinguishable */
6869 static int
6871 {
6877 /* Candidates that involve bad conversions are always worse than those
6878 that don't. */
6884 /* If we have two pseudo-candidates for conversions to the same type,
6885 or two candidates for the same function, arbitrarily pick one. */
6890 /* a viable function F1
6891 is defined to be a better function than another viable function F2 if
6892 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6893 ICSi(F2), and then */
6895 /* for some argument j, ICSj(F1) is a better conversion sequence than
6896 ICSj(F2) */
6898 /* For comparing static and non-static member functions, we ignore
6899 the implicit object parameter of the non-static function. The
6900 standard says to pretend that the static function has an object
6901 parm, but that won't work with operator overloading. */
6904 {
6912 else
6913 {
6916 }
6917 }
6920 {
6926 {
6939 {
6946 else
6951 {
6955 }
6956 else
6958 }
6961 {
6964 }
6966 }
6967 }
6969 /* warn about confusing overload resolution for user-defined conversions,
6970 either between a constructor and a conversion op, or between two
6971 conversion ops. */
6975 {
6981 else
6984 /* We don't want to complain about `X::operator T1 ()'
6985 beating `X::operator T2 () const', when T2 is a no less
6986 cv-qualified version of T1. */
6989 {
6994 {
6997 }
7000 }
7001 else
7007 {
7014 {
7016 }
7017 }
7018 else
7020 }
7025 /* or, if not that,
7026 F1 is a non-template function and F2 is a template function
7027 specialization. */
7034 /* or, if not that,
7035 F1 and F2 are template functions and the function template for F1 is
7036 more specialized than the template for F2 according to the partial
7037 ordering rules. */
7040 {
7041 winner = more_specialized_fn
7044 /* [temp.func.order]: The presence of unused ellipsis and default
7045 arguments has no effect on the partial ordering of function
7046 templates. add_function_candidate() will not have
7047 counted the "this" argument for constructors. */
7051 }
7053 /* or, if not that,
7054 the context is an initialization by user-defined conversion (see
7055 _dcl.init_ and _over.match.user_) and the standard conversion
7056 sequence from the return type of F1 to the destination type (i.e.,
7057 the type of the entity being initialized) is a better conversion
7058 sequence than the standard conversion sequence from the return type
7059 of F2 to the destination type. */
7062 {
7066 }
7068 /* Check whether we can discard a builtin candidate, either because we
7069 have two identical ones or matching builtin and non-builtin candidates.
7071 (Pedantically in the latter case the builtin which matched the user
7072 function should not be added to the overload set, but we spot it here.
7074 [over.match.oper]
7075 ... the builtin candidates include ...
7076 - do not have the same parameter type list as any non-template
7077 non-member candidate. */
7081 {
7087 {
7089 /* Two built-in candidates; arbitrarily pick one. */
7092 /* cand1 is built-in; prefer cand2. */
7094 else
7095 /* cand2 is built-in; prefer cand1. */
7097 }
7098 }
7100 /* If the two function declarations represent the same function (this can
7101 happen with declarations in multiple scopes and arg-dependent lookup),
7102 arbitrarily choose one. But first make sure the default args we're
7103 using match. */
7106 {
7113 {
7114 /* Don't crash if the fn is variadic. */
7119 }
7127 {
7130 {
7132 {
7139 }
7140 else
7143 }
7146 }
7149 }
7151 tweak:
7153 /* Extension: If the worst conversion for one candidate is worse than the
7154 worst conversion for the other, take the first. */
7156 {
7161 {
7166 }
7172 {
7174 {
7176 "ISO C++ says that these are ambiguous, even "
7177 "though the worst conversion for the first is better than "
7181 }
7182 else
7185 }
7186 }
7190 }
7192 /* Given a list of candidates for overloading, find the best one, if any.
7193 This algorithm has a worst case of O(2n) (winner is last), and a best
7194 case of O(n/2) (totally ambiguous); much better than a sorting
7195 algorithm. */
7199 {
7204 /* Walk through the list once, comparing each current champ to the next
7205 candidate, knocking out a candidate or two with each comparison. */
7208 {
7212 else
7213 {
7215 {
7220 }
7221 else
7222 {
7225 }
7228 }
7229 }
7231 /* Make sure the champ is better than all the candidates it hasn't yet
7232 been compared to. */
7235 challenger != champ
7238 {
7242 }
7245 }
7247 /* Returns nonzero if things of type FROM can be converted to TO. */
7249 bool
7251 {
7253 }
7255 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7257 bool
7259 {
7264 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7268 flags);
7271 /* Free all the conversions we allocated. */
7275 }
7277 /* Like can_convert_arg, but allows dubious conversions as well. */
7279 bool
7281 {
7285 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7287 /* Try to perform the conversion. */
7289 flags);
7290 /* Free all the conversions we allocated. */
7294 }
7296 /* Convert EXPR to TYPE. Return the converted expression.
7298 Note that we allow bad conversions here because by the time we get to
7299 this point we are committed to doing the conversion. If we end up
7300 doing a bad conversion, convert_like will complain. */
7302 tree
7304 {
7311 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7316 flags);
7319 {
7321 {
7322 /* If expr has unknown type, then it is an overloaded function.
7323 Call instantiate_type to get good error messages. */
7328 else
7330 }
7332 }
7334 {
7335 /* In a template, we are only concerned about determining the
7336 type of non-dependent expressions, so we do not have to
7337 perform the actual conversion. */
7340 }
7341 else
7344 /* Free all the conversions we allocated. */
7348 }
7350 tree
7352 {
7354 }
7356 /* Convert EXPR to TYPE (as a direct-initialization) if that is
7357 permitted. If the conversion is valid, the converted expression is
7358 returned. Otherwise, NULL_TREE is returned, except in the case
7359 that TYPE is a class type; in that case, an error is issued. If
7360 C_CAST_P is true, then this direction initialization is taking
7361 place as part of a static_cast being attempted as part of a C-style
7362 cast. */
7364 tree
7366 tree expr,
7368 tsubst_flags_t complain)
7369 {
7375 /* [dcl.init]
7377 If the destination type is a (possibly cv-qualified) class type:
7379 -- If the initialization is direct-initialization ...,
7380 constructors are considered. ... If no constructor applies, or
7381 the overload resolution is ambiguous, the initialization is
7382 ill-formed. */
7384 {
7390 }
7392 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7396 c_cast_p,
7397 LOOKUP_NORMAL);
7400 else
7403 c_cast_p,
7404 tf_warning_or_error);
7406 /* Free all the conversions we allocated. */
7410 }
7412 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
7413 is being bound to a temporary. Create and return a new VAR_DECL
7414 with the indicated TYPE; this variable will store the value to
7415 which the reference is bound. */
7417 tree
7419 {
7420 tree var;
7422 /* Create the variable. */
7425 /* Register the variable. */
7427 {
7428 /* Namespace-scope or local static; give it a mangled name. */
7429 tree name;
7436 }
7437 else
7438 /* Create a new cleanup level if necessary. */
7442 }
7444 /* EXPR is the initializer for a variable DECL of reference or
7445 std::initializer_list type. Create, push and return a new VAR_DECL
7446 for the initializer so that it will live as long as DECL. Any
7447 cleanup for the new variable is returned through CLEANUP, and the
7448 code to initialize the new variable is returned through INITP. */
7450 tree
7452 {
7453 tree init;
7454 tree type;
7455 tree var;
7457 /* Create the temporary variable. */
7461 /* If the rvalue is the result of a function call it will be
7462 a TARGET_EXPR. If it is some other construct (such as a
7463 member access expression where the underlying object is
7464 itself the result of a function call), turn it into a
7465 TARGET_EXPR here. It is important that EXPR be a
7466 TARGET_EXPR below since otherwise the INIT_EXPR will
7467 attempt to make a bitwise copy of EXPR to initialize
7468 VAR. */
7471 /* Create the INIT_EXPR that will initialize the temporary
7472 variable. */
7475 {
7480 else
7483 /* We must be careful to destroy the temporary only
7484 after its initialization has taken place. If the
7485 initialization throws an exception, then the
7486 destructor should not be run. We cannot simply
7487 transform INIT into something like:
7489 (INIT, ({ CLEANUP_STMT; }))
7491 because emit_local_var always treats the
7492 initializer as a full-expression. Thus, the
7493 destructor would run too early; it would run at the
7494 end of initializing the reference variable, rather
7495 than at the end of the block enclosing the
7496 reference variable.
7498 The solution is to pass back a cleanup expression
7499 which the caller is responsible for attaching to
7500 the statement tree. */
7501 }
7502 else
7503 {
7507 static_aggregates);
7508 }
7512 }
7514 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
7515 initializing a variable of that TYPE. If DECL is non-NULL, it is
7516 the VAR_DECL being initialized with the EXPR. (In that case, the
7517 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
7518 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
7519 return, if *CLEANUP is no longer NULL, it will be an expression
7520 that should be pushed as a cleanup after the returned expression
7521 is used to initialize DECL.
7523 Return the converted expression. */
7525 tree
7527 {
7534 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7538 LOOKUP_NORMAL);
7540 {
7546 else
7551 }
7553 /* If DECL is non-NULL, then this special rule applies:
7555 [class.temporary]
7557 The temporary to which the reference is bound or the temporary
7558 that is the complete object to which the reference is bound
7559 persists for the lifetime of the reference.
7561 The temporaries created during the evaluation of the expression
7562 initializing the reference, except the temporary to which the
7563 reference is bound, are destroyed at the end of the
7564 full-expression in which they are created.
7566 In that case, we store the converted expression into a new
7567 VAR_DECL in a new scope.
7569 However, we want to be careful not to create temporaries when
7570 they are not required. For example, given:
7572 struct B {};
7573 struct D : public B {};
7574 D f();
7575 const B& b = f();
7577 there is no need to copy the return value from "f"; we can just
7578 extend its lifetime. Similarly, given:
7580 struct S {};
7581 struct T { operator S(); };
7582 T t;
7583 const S& s = t;
7585 we can extend the lifetime of the return value of the conversion
7586 operator. */
7589 {
7590 tree var;
7591 tree base_conv_type;
7593 /* Skip over the REF_BIND. */
7595 /* If the next conversion is a BASE_CONV, skip that too -- but
7596 remember that the conversion was required. */
7598 {
7601 }
7602 else
7604 /* Perform the remainder of the conversion. */
7610 tf_warning_or_error);
7613 else
7614 {
7616 {
7617 tree init;
7619 /* Use its address to initialize the reference variable. */
7627 }
7628 else
7629 /* Take the address of EXPR. */
7631 /* If a BASE_CONV was required, perform it now. */
7633 expr = (perform_implicit_conversion
7635 tf_warning_or_error));
7637 }
7638 }
7639 else
7640 /* Perform the conversion. */
7643 /* Free all the conversions we allocated. */
7647 }
7649 /* Returns true iff TYPE is some variant of std::initializer_list. */
7651 bool
7653 {
7657 }
7659 /* Returns true iff DECL is a list constructor: i.e. a constructor which
7660 will accept an argument list of a single std::initializer_list<T>. */
7662 bool
7664 {
7666 tree arg;
7678 /* There are more non-defaulted parms. */
7682 }