| blob | c618b2938af8e01166584366a09a53990d73723b |
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);
206 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
207 NAME can take many forms... */
209 bool
211 {
212 /* Just accept something we've already complained about. */
221 {
227 else
229 }
230 else
231 {
232 /* In the case of:
234 template <class T> struct S { ~S(); };
235 int i;
236 i.~S();
238 NAME will be a class template. */
241 }
246 }
248 /* We want the address of a function or method. We avoid creating a
249 pointer-to-member function. */
251 tree
253 {
256 /* We have to do these by hand to avoid real pointer to member
257 functions. */
259 {
261 {
265 }
267 }
268 else
272 }
274 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
275 POINTER_TYPE to those. Note, pointer to member function types
276 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
277 two variants. build_call_a is the primitive taking an array of
278 arguments, while build_call_n is a wrapper that handles varargs. */
280 tree
282 {
285 else
286 {
296 }
297 }
299 tree
301 {
304 tree decl;
305 tree result_type;
306 tree fntype;
316 /* An rvalue has no cv-qualifiers. */
322 {
325 {
326 /* We invoke build_call directly for several library
327 functions. These may have been declared normally if
328 we're building libgcc, so we can't just check
329 DECL_ARTIFICIAL. */
334 }
335 }
336 else
339 /* We check both the decl and the type; a function may be known not to
340 throw without being declared throw(). */
354 /* Don't pass empty class objects by value. This is useful
355 for tags in STL, which are used to control overload resolution.
356 We don't need to handle other cases of copying empty classes. */
361 {
365 }
373 }
375 /* Build something of the form ptr->method (args)
376 or object.method (args). This can also build
377 calls to constructors, and find friends.
379 Member functions always take their class variable
380 as a pointer.
382 INSTANCE is a class instance.
384 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
386 PARMS help to figure out what that NAME really refers to.
388 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
389 down to the real instance type to use for access checking. We need this
390 information to get protected accesses correct.
392 FLAGS is the logical disjunction of zero or more LOOKUP_
393 flags. See cp-tree.h for more info.
395 If this is all OK, calls build_function_call with the resolved
396 member function.
398 This function must also handle being called to perform
399 initialization, promotion/coercion of arguments, and
400 instantiation of default parameters.
402 Note that NAME may refer to an instance variable name. If
403 `operator()()' is defined for the type of that field, then we return
404 that result. */
406 /* New overloading code. */
414 };
417 /* The FUNCTION_DECL that will be called if this candidate is
418 selected by overload resolution. */
419 tree fn;
420 /* If not NULL_TREE, the first argument to use when calling this
421 function. */
422 tree first_arg;
423 /* The rest of the arguments to use when calling this function. If
424 there are no further arguments this may be NULL or it may be an
425 empty vector. */
427 /* The implicit conversion sequences for each of the arguments to
428 FN. */
430 /* The number of implicit conversion sequences. */
432 /* If FN is a user-defined conversion, the standard conversion
433 sequence from the type returned by FN to the desired destination
434 type. */
437 /* If FN is a member function, the binfo indicating the path used to
438 qualify the name of FN at the call site. This path is used to
439 determine whether or not FN is accessible if it is selected by
440 overload resolution. The DECL_CONTEXT of FN will always be a
441 (possibly improper) base of this binfo. */
442 tree access_path;
443 /* If FN is a non-static member function, the binfo indicating the
444 subobject to which the `this' pointer should be converted if FN
445 is selected by overload resolution. The type pointed to the by
446 the `this' pointer must correspond to the most derived class
447 indicated by the CONVERSION_PATH. */
448 tree conversion_path;
449 tree template_decl;
452 };
454 /* Returns true iff T is a null pointer constant in the sense of
455 [conv.ptr]. */
457 bool
459 {
460 /* [conv.ptr]
462 A null pointer constant is an integral constant expression
463 (_expr.const_) rvalue of integer type that evaluates to zero or
464 an rvalue of type std::nullptr_t. */
470 {
474 }
476 }
478 /* Returns nonzero if PARMLIST consists of only default parms and/or
479 ellipsis. */
481 bool
483 {
489 }
491 /* Allocate N bytes of memory from the conversion obstack. The memory
492 is zeroed before being returned. */
496 {
499 {
502 }
506 }
508 /* Dynamically allocate a conversion. */
512 {
517 }
519 #ifdef ENABLE_CHECKING
521 /* Make sure that all memory on the conversion obstack has been
522 freed. */
524 void
526 {
530 }
534 /* Dynamically allocate an array of N conversions. */
538 {
540 }
544 {
548 /* Note that the caller is responsible for filling in t->cand for
549 user-defined conversions. */
555 {
571 }
577 }
579 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
580 specialization of std::initializer_list<T>, if such a conversion is
581 possible. */
585 {
591 tree val;
594 {
595 conversion *sub
602 }
610 {
618 }
621 }
623 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
624 aggregate class, if such a conversion is possible. */
628 {
634 {
636 {
644 }
647 }
658 }
660 /* Build a representation of the identity conversion from EXPR to
661 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
665 {
673 }
675 /* Converting from EXPR to TYPE was ambiguous in the sense that there
676 were multiple user-defined conversions to accomplish the job.
677 Build a conversion that indicates that ambiguity. */
681 {
689 }
691 tree
693 {
697 }
699 /* Returns the standard conversion path (see [conv]) from type FROM to type
700 TO, if any. For proper handling of null pointer constants, you must
701 also pass the expression EXPR to convert from. If C_CAST_P is true,
702 this conversion is coming from a C-style cast. */
707 {
714 {
717 }
723 {
731 }
738 {
742 }
744 {
746 {
747 tree bitfield_type;
750 {
753 }
754 }
756 }
758 /* Allow conversion between `__complex__' data types. */
760 {
761 /* The standard conversion sequence to convert FROM to TO is
762 the standard conversion sequence to perform componentwise
763 conversion. */
768 {
771 }
772 else
776 }
781 /* [conv.ptr]
782 A null pointer constant can be converted to a pointer type; ... A
783 null pointer constant of integral type can be converted to an
784 rvalue of type std::nullptr_t. */
791 {
792 /* For backwards brain damage compatibility, allow interconversion of
793 pointers and integers with a pedwarn. */
796 }
798 {
799 /* For backwards brain damage compatibility, allow interconversion of
800 enums and integers with a pedwarn. */
803 }
806 {
807 tree to_pointee;
808 tree from_pointee;
813 ;
817 {
818 from = build_pointer_type
822 }
824 {
829 && (same_type_ignoring_top_level_qualifiers_p
832 {
836 }
839 }
842 /* [conv.ptr]
844 An rvalue of type "pointer to cv D," where D is a
845 class type, can be converted to an rvalue of type
846 "pointer to cv B," where B is a base class (clause
847 _class.derived_) of D. If B is an inaccessible
848 (clause _class.access_) or ambiguous
849 (_class.member.lookup_) base class of D, a program
850 that necessitates this conversion is ill-formed.
851 Therefore, we use DERIVED_FROM_P, and do not check
852 access or uniqueness. */
854 {
855 from =
861 }
864 {
867 }
868 else
869 {
872 }
877 /* In a C-style cast, we ignore CV-qualification because we
878 are allowed to perform a static_cast followed by a
879 const_cast. */
884 /* converting from string constant to char *. */
887 {
890 }
891 else
895 }
897 {
914 }
916 {
917 /* [conv.bool]
919 An rvalue of arithmetic, unscoped enumeration, pointer, or
920 pointer to member type can be converted to an rvalue of type
921 bool. ... An rvalue of type std::nullptr_t can be converted
922 to an rvalue of type bool; */
928 {
937 }
940 }
941 /* We don't check for ENUMERAL_TYPE here because there are no standard
942 conversions to enum type. */
943 /* As an extension, allow conversion to complex type. */
945 {
951 /* Give this a better rank if it's a promotion. */
955 }
961 {
965 /* The derived-to-base conversion indicates the initialization
966 of a parameter with base type from an object of a derived
967 type. A temporary object is created to hold the result of
968 the conversion unless we're binding directly to a reference. */
970 }
971 else
978 }
980 /* Returns nonzero if T1 is reference-related to T2. */
982 bool
984 {
988 /* [dcl.init.ref]
990 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
991 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
992 of T2. */
996 }
998 /* Returns nonzero if T1 is reference-compatible with T2. */
1000 static bool
1002 {
1003 /* [dcl.init.ref]
1005 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
1006 reference-related to T2 and cv1 is the same cv-qualification as,
1007 or greater cv-qualification than, cv2. */
1010 }
1012 /* Determine whether or not the EXPR (of class type S) can be
1013 converted to T as in [over.match.ref]. */
1017 {
1018 tree conversions;
1019 tree first_arg;
1021 tree t;
1030 /* [over.match.ref]
1032 Assuming that "cv1 T" is the underlying type of the reference
1033 being initialized, and "cv S" is the type of the initializer
1034 expression, with S a class type, the candidate functions are
1035 selected as follows:
1037 --The conversion functions of S and its base classes are
1038 considered. Those that are not hidden within S and yield type
1039 "reference to cv2 T2", where "cv1 T" is reference-compatible
1040 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1042 The argument list has one argument, which is the initializer
1043 expression. */
1047 /* Conceptually, we should take the address of EXPR and put it in
1048 the argument list. Unfortunately, however, that can result in
1049 error messages, which we should not issue now because we are just
1050 trying to find a conversion operator. Therefore, we use NULL,
1051 cast to the appropriate type. */
1056 /* We're performing a user-defined conversion to a desired type, so set
1057 this for the benefit of add_candidates. */
1061 {
1072 {
1073 /* Now, see if the conversion function really returns
1074 an lvalue of the appropriate type. From the
1075 point of view of unification, simply returning an
1076 rvalue of the right type is good enough. */
1081 {
1083 }
1084 else
1085 {
1087 /* Build a standard conversion sequence indicating the
1088 binding from the reference type returned by the
1089 function to the desired REFERENCE_TYPE. */
1090 identity_conv
1093 NULL_TREE);
1094 cand->second_conv
1095 = (direct_reference_binding
1102 /* Don't allow binding of lvalues to rvalue references. */
1106 }
1107 }
1108 }
1111 /* If none of the conversion functions worked out, let our caller
1112 know. */
1120 /* Now that we know that this is the function we're going to use fix
1121 the dummy first argument. */
1126 /* Build a user-defined conversion sequence representing the
1127 conversion. */
1136 /* Merge it with the standard conversion sequence from the
1137 conversion function's return type to the desired type. */
1141 }
1143 /* A reference of the indicated TYPE is being bound directly to the
1144 expression represented by the implicit conversion sequence CONV.
1145 Return a conversion sequence for this binding. */
1149 {
1150 tree t;
1157 /* [over.ics.rank]
1159 When a parameter of reference type binds directly
1160 (_dcl.init.ref_) to an argument expression, the implicit
1161 conversion sequence is the identity conversion, unless the
1162 argument expression has a type that is a derived class of the
1163 parameter type, in which case the implicit conversion sequence is
1164 a derived-to-base Conversion.
1166 If the parameter binds directly to the result of applying a
1167 conversion function to the argument expression, the implicit
1168 conversion sequence is a user-defined conversion sequence
1169 (_over.ics.user_), with the second standard conversion sequence
1170 either an identity conversion or, if the conversion function
1171 returns an entity of a type that is a derived class of the
1172 parameter type, a derived-to-base conversion. */
1174 {
1175 /* Represent the derived-to-base conversion. */
1177 /* We will actually be binding to the base-class subobject in
1178 the derived class, so we mark this conversion appropriately.
1179 That way, convert_like knows not to generate a temporary. */
1181 }
1183 }
1185 /* Returns the conversion path from type FROM to reference type TO for
1186 purposes of reference binding. For lvalue binding, either pass a
1187 reference type to FROM or an lvalue expression to EXPR. If the
1188 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1189 the conversion returned. If C_CAST_P is true, this
1190 conversion is coming from a C-style cast. */
1194 {
1198 tree tfrom;
1204 {
1209 }
1212 {
1213 /* Anything with reference type is an lvalue. */
1216 }
1219 {
1222 flags);
1225 {
1230 }
1231 }
1240 /* Figure out whether or not the types are reference-related and
1241 reference compatible. We have do do this after stripping
1242 references from FROM. */
1244 /* If this is a C cast, first convert to an appropriately qualified
1245 type, so that we can later do a const_cast to the desired type. */
1251 /* Directly bind reference when target expression's type is compatible with
1252 the reference and expression is an lvalue. In DR391, the wording in
1253 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1254 const and rvalue references to rvalues of compatible class type.
1255 We should also do direct bindings for non-class "rvalues" derived from
1256 rvalue references. */
1258 && (is_lvalue
1263 {
1264 /* [dcl.init.ref]
1266 If the initializer expression
1268 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1269 is reference-compatible with "cv2 T2,"
1271 the reference is bound directly to the initializer expression
1272 lvalue.
1274 [...]
1275 If the initializer expression is an rvalue, with T2 a class type,
1276 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1277 is bound to the object represented by the rvalue or to a sub-object
1278 within that object. */
1284 /* The top-level caller requested that we pretend that the lvalue
1285 be treated as an rvalue. */
1287 else
1288 conv->rvaluedness_matches_p
1293 /* For the purposes of overload resolution, we ignore the fact
1294 this expression is a bitfield or packed field. (In particular,
1295 [over.ics.ref] says specifically that a function with a
1296 non-const reference parameter is viable even if the
1297 argument is a bitfield.)
1299 However, when we actually call the function we must create
1300 a temporary to which to bind the reference. If the
1301 reference is volatile, or isn't const, then we cannot make
1302 a temporary, so we just issue an error when the conversion
1303 actually occurs. */
1306 /* Don't allow binding of lvalues to rvalue references. */
1312 }
1313 /* [class.conv.fct] A conversion function is never used to convert a
1314 (possibly cv-qualified) object to the (possibly cv-qualified) same
1315 object type (or a reference to it), to a (possibly cv-qualified) base
1316 class of that type (or a reference to it).... */
1319 {
1320 /* [dcl.init.ref]
1322 If the initializer expression
1324 -- has a class type (i.e., T2 is a class type) can be
1325 implicitly converted to an lvalue of type "cv3 T3," where
1326 "cv1 T1" is reference-compatible with "cv3 T3". (this
1327 conversion is selected by enumerating the applicable
1328 conversion functions (_over.match.ref_) and choosing the
1329 best one through overload resolution. (_over.match_).
1331 the reference is bound to the lvalue result of the conversion
1332 in the second case. */
1336 }
1338 /* From this point on, we conceptually need temporaries, even if we
1339 elide them. Only the cases above are "direct bindings". */
1343 /* [over.ics.rank]
1345 When a parameter of reference type is not bound directly to an
1346 argument expression, the conversion sequence is the one required
1347 to convert the argument expression to the underlying type of the
1348 reference according to _over.best.ics_. Conceptually, this
1349 conversion sequence corresponds to copy-initializing a temporary
1350 of the underlying type with the argument expression. Any
1351 difference in top-level cv-qualification is subsumed by the
1352 initialization itself and does not constitute a conversion. */
1354 /* [dcl.init.ref]
1356 Otherwise, the reference shall be to a non-volatile const type.
1358 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1362 /* [dcl.init.ref]
1364 Otherwise, a temporary of type "cv1 T1" is created and
1365 initialized from the initializer expression using the rules for a
1366 non-reference copy initialization. If T1 is reference-related to
1367 T2, cv1 must be the same cv-qualification as, or greater
1368 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1372 /* We're generating a temporary now, but don't bind any more in the
1373 conversion (specifically, don't slice the temporary returned by a
1374 conversion operator). */
1377 /* Temporaries are copy-initialized, except for this hack to allow
1378 explicit conversion ops to the copy ctor. See also
1379 add_function_candidate. */
1385 flags);
1390 /* This reference binding, unlike those above, requires the
1391 creation of a temporary. */
1396 }
1398 /* Returns the implicit conversion sequence (see [over.ics]) from type
1399 FROM to type TO. The optional expression EXPR may affect the
1400 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1401 true, this conversion is coming from a C-style cast. */
1406 {
1415 else
1422 {
1426 /* Allow conversion from an initializer-list with one element to a
1427 scalar type. */
1429 {
1431 tree elt;
1437 else
1443 {
1446 /* Too many levels of braces, i.e. '{{1}}'. */
1449 }
1450 }
1451 }
1457 {
1470 /* We used to try to bind a reference to a temporary here, but that
1471 is now handled after the recursive call to this function at the end
1472 of reference_binding. */
1474 }
1477 }
1479 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1480 functions. ARGS will not be changed until a single candidate is
1481 selected. */
1489 {
1505 }
1507 /* Create an overload candidate for the function or method FN called
1508 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1509 FLAGS is passed on to implicit_conversion.
1511 This does not change ARGS.
1513 CTYPE, if non-NULL, is the type we want to pretend this function
1514 comes from for purposes of overload resolution. */
1521 {
1525 tree parmnode;
1530 /* At this point we should not see any functions which haven't been
1531 explicitly declared, except for friend functions which will have
1532 been found using argument dependent lookup. */
1535 /* The `this', `in_chrg' and VTT arguments to constructors are not
1536 considered in overload resolution. */
1538 {
1542 {
1545 }
1546 }
1547 else
1553 /* 13.3.2 - Viable functions [over.match.viable]
1554 First, to be a viable function, a candidate function shall have enough
1555 parameters to agree in number with the arguments in the list.
1557 We need to check this first; otherwise, checking the ICSes might cause
1558 us to produce an ill-formed template instantiation. */
1562 {
1566 }
1571 /* Make sure there are default args for the rest of the parms. */
1578 /* Second, for F to be a viable function, there shall exist for each
1579 argument an implicit conversion sequence that converts that argument
1580 to the corresponding parameter of F. */
1585 {
1595 else
1604 {
1608 /* The type of the implicit object parameter ('this') for
1609 overload resolution is not always the same as for the
1610 function itself; conversion functions are considered to
1611 be members of the class being converted, and functions
1612 introduced by a using-declaration are considered to be
1613 members of the class that uses them.
1615 Since build_over_call ignores the ICS for the `this'
1616 parameter, we can just change the parm type. */
1618 {
1619 parmtype
1623 }
1627 {
1628 /* Hack: Direct-initialize copy parm (i.e. suppress
1629 LOOKUP_ONLYCONVERTING) to make explicit conversion ops
1630 work. See also reference_binding. */
1634 }
1635 else
1640 }
1641 else
1642 {
1645 }
1652 {
1655 }
1662 }
1664 out:
1667 }
1669 /* Create an overload candidate for the conversion function FN which will
1670 be invoked for expression OBJ, producing a pointer-to-function which
1671 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1672 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1673 passed on to implicit_conversion.
1675 Actually, we don't really care about FN; we care about the type it
1676 converts to. There may be multiple conversion functions that will
1677 convert to that type, and we rely on build_user_type_conversion_1 to
1678 choose the best one; so when we create our candidate, we record the type
1679 instead of the function. */
1685 {
1701 /* Don't bother looking up the same type twice. */
1706 {
1714 else
1721 flags);
1727 else
1728 {
1731 }
1745 }
1755 }
1757 static void
1761 {
1774 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
1775 conversion ops are allowed. We handle that here by just checking for
1776 boolean_type_node because other operators don't ask for it. COND_EXPR
1777 also does contextual conversion to bool for the first operand, but we
1778 handle that in build_conditional_expr, and type1 here is operand 2. */
1783 {
1790 {
1792 /* We need something for printing the candidate. */
1794 }
1798 }
1800 /* For COND_EXPR we rearranged the arguments; undo that now. */
1802 {
1809 else
1811 }
1817 viable);
1818 }
1820 static bool
1822 {
1824 }
1826 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1828 static bool
1830 {
1831 /* [over.built]
1833 In this section, the term promoted integral type is used to refer
1834 to those integral types which are preserved by integral promotion
1835 (including e.g. int and long but excluding e.g. char).
1836 Similarly, the term promoted arithmetic type refers to promoted
1837 integral types plus floating types. */
1841 }
1843 /* Create any builtin operator overload candidates for the operator in
1844 question given the converted operand types TYPE1 and TYPE2. The other
1845 args are passed through from add_builtin_candidates to
1846 build_builtin_candidate.
1848 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1849 If CODE is requires candidates operands of the same type of the kind
1850 of which TYPE1 and TYPE2 are, we add both candidates
1851 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1853 static void
1857 {
1859 {
1867 }
1870 {
1872 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1873 and VQ is either volatile or empty, there exist candidate operator
1874 functions of the form
1875 VQ T& operator++(VQ T&);
1876 T operator++(VQ T&, int);
1877 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1878 type other than bool, and VQ is either volatile or empty, there exist
1879 candidate operator functions of the form
1880 VQ T& operator--(VQ T&);
1881 T operator--(VQ T&, int);
1882 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1883 complete object type, and VQ is either volatile or empty, there exist
1884 candidate operator functions of the form
1885 T*VQ& operator++(T*VQ&);
1886 T*VQ& operator--(T*VQ&);
1887 T* operator++(T*VQ&, int);
1888 T* operator--(T*VQ&, int); */
1897 {
1900 }
1903 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1904 exist candidate operator functions of the form
1906 T& operator*(T*);
1908 8 For every function type T, there exist candidate operator functions of
1909 the form
1910 T& operator*(T*); */
1919 /* 9 For every type T, there exist candidate operator functions of the form
1920 T* operator+(T*);
1922 10For every promoted arithmetic type T, there exist candidate operator
1923 functions of the form
1924 T operator+(T);
1925 T operator-(T); */
1935 /* 11For every promoted integral type T, there exist candidate operator
1936 functions of the form
1937 T operator~(T); */
1944 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1945 is the same type as C2 or is a derived class of C2, T is a complete
1946 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1947 there exist candidate operator functions of the form
1948 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1949 where CV12 is the union of CV1 and CV2. */
1954 {
1962 }
1965 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1966 didate operator functions of the form
1967 LR operator*(L, R);
1968 LR operator/(L, R);
1969 LR operator+(L, R);
1970 LR operator-(L, R);
1971 bool operator<(L, R);
1972 bool operator>(L, R);
1973 bool operator<=(L, R);
1974 bool operator>=(L, R);
1975 bool operator==(L, R);
1976 bool operator!=(L, R);
1977 where LR is the result of the usual arithmetic conversions between
1978 types L and R.
1980 14For every pair of types T and I, where T is a cv-qualified or cv-
1981 unqualified complete object type and I is a promoted integral type,
1982 there exist candidate operator functions of the form
1983 T* operator+(T*, I);
1984 T& operator[](T*, I);
1985 T* operator-(T*, I);
1986 T* operator+(I, T*);
1987 T& operator[](I, T*);
1989 15For every T, where T is a pointer to complete object type, there exist
1990 candidate operator functions of the form112)
1991 ptrdiff_t operator-(T, T);
1993 16For every pointer or enumeration type T, there exist candidate operator
1994 functions of the form
1995 bool operator<(T, T);
1996 bool operator>(T, T);
1997 bool operator<=(T, T);
1998 bool operator>=(T, T);
1999 bool operator==(T, T);
2000 bool operator!=(T, T);
2002 17For every pointer to member type T, there exist candidate operator
2003 functions of the form
2004 bool operator==(T, T);
2005 bool operator!=(T, T); */
2012 {
2015 }
2028 {
2031 }
2033 {
2036 }
2037 /* Fall through. */
2054 {
2057 }
2061 {
2064 }
2072 {
2075 }
2077 {
2080 }
2083 /* 18For every pair of promoted integral types L and R, there exist candi-
2084 date operator functions of the form
2085 LR operator%(L, R);
2086 LR operator&(L, R);
2087 LR operator^(L, R);
2088 LR operator|(L, R);
2089 L operator<<(L, R);
2090 L operator>>(L, R);
2091 where LR is the result of the usual arithmetic conversions between
2092 types L and R. */
2100 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2104 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2105 type, VQ is either volatile or empty, and R is a promoted arithmetic
2106 type, there exist candidate operator functions of the form
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);
2113 20For every pair T, VQ), where T is any type and VQ is either volatile
2114 or empty, there exist candidate operator functions of the form
2115 T*VQ& operator=(T*VQ&, T*);
2117 21For every pair T, VQ), where T is a pointer to member type and VQ is
2118 either volatile or empty, there exist candidate operator functions of
2119 the form
2120 VQ T& operator=(VQ T&, T);
2122 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2123 unqualified complete object type, VQ is either volatile or empty, and
2124 I is a promoted integral type, there exist candidate operator func-
2125 tions of the form
2126 T*VQ& operator+=(T*VQ&, I);
2127 T*VQ& operator-=(T*VQ&, I);
2129 23For every triple L, VQ, R), where L is an integral or enumeration
2130 type, VQ is either volatile or empty, and R is a promoted integral
2131 type, there exist candidate operator functions of the form
2133 VQ L& operator%=(VQ L&, R);
2134 VQ L& operator<<=(VQ L&, R);
2135 VQ L& operator>>=(VQ L&, R);
2136 VQ L& operator&=(VQ L&, R);
2137 VQ L& operator^=(VQ L&, R);
2138 VQ L& operator|=(VQ L&, R); */
2142 {
2146 {
2149 }
2162 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2175 {
2178 }
2183 }
2188 /* [over.built]
2190 For every pair of promoted arithmetic types L and R, there
2191 exist candidate operator functions of the form
2193 LR operator?(bool, L, R);
2195 where LR is the result of the usual arithmetic conversions
2196 between types L and R.
2198 For every type T, where T is a pointer or pointer-to-member
2199 type, there exist candidate operator functions of the form T
2200 operator?(bool, T, T); */
2204 /* That's OK. */
2207 /* Otherwise, the types should be pointers. */
2212 /* We don't check that the two types are the same; the logic
2213 below will actually create two candidates; one in which both
2214 parameter types are TYPE1, and one in which both parameter
2215 types are TYPE2. */
2220 }
2222 /* If we're dealing with two pointer types or two enumeral types,
2223 we need candidates for both of them. */
2232 {
2233 build_builtin_candidate
2235 build_builtin_candidate
2238 }
2240 build_builtin_candidate
2242 }
2244 tree
2246 {
2254 }
2256 /* There are three conditions of builtin candidates:
2258 1) bool-taking candidates. These are the same regardless of the input.
2259 2) pointer-pair taking candidates. These are generated for each type
2260 one of the input types converts to.
2261 3) arithmetic candidates. According to the standard, we should generate
2262 all of these, but I'm trying not to...
2264 Here we generate a superset of the possible candidates for this particular
2265 case. That is a subset of the full set the standard defines, plus some
2266 other cases which the standard disallows. add_builtin_candidate will
2267 filter out the invalid set. */
2269 static void
2273 {
2277 /* TYPES[i] is the set of possible builtin-operator parameter types
2278 we will consider for the Ith argument. These are represented as
2279 a TREE_LIST; the TREE_VALUE of each node is the potential
2280 parameter type. */
2284 {
2287 else
2289 }
2292 {
2293 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2294 and VQ is either volatile or empty, there exist candidate operator
2295 functions of the form
2296 VQ T& operator++(VQ T&); */
2306 /* 24There also exist candidate operator functions of the form
2307 bool operator!(bool);
2308 bool operator&&(bool, bool);
2309 bool operator||(bool, bool); */
2312 build_builtin_candidate
2319 build_builtin_candidate
2337 /* Fall through. */
2341 }
2346 {
2348 ;
2350 {
2351 tree convs;
2360 {
2367 }
2373 {
2386 {
2392 }
2396 }
2397 }
2398 else
2399 {
2405 {
2411 }
2413 }
2414 }
2416 /* Run through the possible parameter types of both arguments,
2417 creating candidates with those parameter types. */
2419 {
2422 add_builtin_candidate
2425 else
2426 add_builtin_candidate
2429 }
2430 }
2433 /* If TMPL can be successfully instantiated as indicated by
2434 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2436 TMPL is the template. EXPLICIT_TARGS are any explicit template
2437 arguments. ARGLIST is the arguments provided at the call-site.
2438 This does not change ARGLIST. The RETURN_TYPE is the desired type
2439 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2440 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2441 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2449 {
2459 tree arg;
2462 tree fn;
2464 /* We don't do deduction on the in-charge parameter, the VTT
2465 parameter or 'this'. */
2467 {
2470 else
2472 }
2477 {
2480 else
2482 }
2492 {
2495 }
2499 {
2502 }
2506 args_without_in_chrg,
2507 nargs_without_in_chrg,
2517 /* In [class.copy]:
2519 A member function template is never instantiated to perform the
2520 copy of a class object to an object of its class type.
2522 It's a little unclear what this means; the standard explicitly
2523 does allow a template to be used to copy a class. For example,
2524 in:
2526 struct A {
2527 A(A&);
2528 template <class T> A(const T&);
2529 };
2530 const A f ();
2531 void g () { A a (f ()); }
2533 the member template will be used to make the copy. The section
2534 quoted above appears in the paragraph that forbids constructors
2535 whose only parameter is (a possibly cv-qualified variant of) the
2536 class type, and a logical interpretation is that the intent was
2537 to forbid the instantiation of member templates which would then
2538 have that form. */
2540 {
2543 ctype))
2545 }
2548 /* Aha, this is a conversion function. */
2551 else
2556 /* This situation can occur if a member template of a template
2557 class is specialized. Then, instantiate_template might return
2558 an instantiation of the specialization, in which case the
2559 DECL_TI_TEMPLATE field will point at the original
2560 specialization. For example:
2562 template <class T> struct S { template <class U> void f(U);
2563 template <> void f(int) {}; };
2564 S<double> sd;
2565 sd.f(3);
2567 Here, TMPL will be template <class U> S<double>::f(U).
2568 And, instantiate template will give us the specialization
2569 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2570 for this will point at template <class T> template <> S<T>::f(int),
2571 so that we can find the definition. For the purposes of
2572 overload resolution, however, we want the original TMPL. */
2574 else
2578 }
2586 unification_kind_t strict)
2587 {
2588 return
2593 }
2601 tree conversion_path)
2602 {
2603 return
2607 }
2609 /* The CANDS are the set of candidates that were considered for
2610 overload resolution. Return the set of viable candidates. If none
2611 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2612 is true if a candidate should be considered viable only if it is
2613 strictly viable. */
2619 {
2630 {
2633 {
2639 }
2640 else
2642 }
2645 }
2647 static bool
2649 {
2654 }
2656 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2657 words, it is about to become the "this" pointer for a member
2658 function call. Take the address of the object. */
2660 static tree
2662 {
2663 /* In a template, we are only concerned about the type of the
2664 expression, so we can take a shortcut. */
2669 }
2671 /* Returns true iff functions are equivalent. Equivalent functions are
2672 not '==' only if one is a function-local extern function or if
2673 both are extern "C". */
2677 {
2682 }
2684 /* Print information about one overload candidate CANDIDATE. MSGSTR
2685 is the text to print before the candidate itself.
2687 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2688 to have been run through gettext by the caller. This wart makes
2689 life simpler in print_z_candidates and for the translators. */
2691 static void
2693 {
2695 {
2705 else
2708 }
2715 else
2717 }
2719 static void
2721 {
2730 /* Remove deleted candidates. */
2733 {
2737 else
2739 }
2740 /* ...if there are any non-deleted ones. */
2744 /* There may be duplicates in the set of candidates. We put off
2745 checking this condition as long as possible, since we have no way
2746 to eliminate duplicates from a set of functions in less than n^2
2747 time. Now we are about to emit an error message, so it is more
2748 permissible to go slowly. */
2750 {
2752 /* Skip builtin candidates and conversion functions. */
2757 {
2761 else
2763 }
2764 }
2769 {
2772 }
2774 }
2776 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2777 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2778 the result of the conversion function to convert it to the final
2779 desired type. Merge the two sequences into a single sequence,
2780 and return the merged sequence. */
2784 {
2789 /* Find the end of the second conversion sequence. */
2794 /* Replace the identity conversion with the user conversion
2795 sequence. */
2798 /* The entire sequence is a user-conversion sequence. */
2802 }
2804 /* Returns the best overload candidate to perform the requested
2805 conversion. This function is used for three the overloading situations
2806 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2807 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2808 per [dcl.init.ref], so we ignore temporary bindings. */
2812 {
2823 /* We represent conversion within a hierarchy using RVALUE_CONV and
2824 BASE_CONV, as specified by [over.best.ics]; these become plain
2825 constructor calls, as specified in [dcl.init]. */
2833 {
2838 {
2839 /* [class.conv.fct] A conversion function is never used to
2840 convert a (possibly cv-qualified) object to the (possibly
2841 cv-qualified) same object type (or a reference to it), to a
2842 (possibly cv-qualified) base class of that type (or a
2843 reference to it)... */
2844 }
2845 else
2848 }
2855 /* It's OK to bind a temporary for converting constructor arguments, but
2856 not in converting the return value of a conversion operator. */
2861 {
2868 {
2869 /* For list-initialization we consider explicit constructors, but
2870 give an error if one is selected. */
2872 /* If the class has a list ctor, try passing the list as a single
2873 argument first, but only consider list ctors. */
2876 else
2878 }
2880 /* We should never try to call the abstract or base constructor
2881 from here. */
2885 /* If EXPR is not an initializer-list, or if totype has a list
2886 constructor, try EXPR as a single argument. */
2888 {
2893 }
2895 /* If we didn't find a suitable list constructor for an initializer-list,
2896 try breaking it apart. */
2898 {
2900 /* We aren't looking for list-ctors anymore. */
2902 /* We still allow more conversions within an init-list. */
2904 /* But not for the copy ctor. */
2909 }
2912 {
2915 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2916 set, then this is copy-initialization. In that case, "The
2917 result of the call is then used to direct-initialize the
2918 object that is the destination of the copy-initialization."
2919 [dcl.init]
2921 We represent this in the conversion sequence with an
2922 rvalue conversion, which means a constructor call. */
2925 cand->second_conv
2927 }
2928 }
2934 {
2938 /* If we are called to convert to a reference type, we are trying to
2939 find an lvalue binding, so don't even consider temporaries. If
2940 we don't find an lvalue binding, the caller will try again to
2941 look for a temporary binding. */
2952 {
2953 conversion *ics
2959 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
2960 copy-initialization. In that case, "The result of the
2961 call is then used to direct-initialize the object that is
2962 the destination of the copy-initialization." [dcl.init]
2964 We represent this in the conversion sequence with an
2965 rvalue conversion, which means a constructor call. But
2966 don't add a second rvalue conversion if there's already
2967 one there. Which there really shouldn't be, but it's
2968 harmless since we'd add it here anyway. */
2979 }
2980 }
2988 {
2990 {
2994 }
3001 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3002 ambiguous conversion is no worse than another user-defined
3003 conversion. */
3006 }
3008 /* Build the user conversion sequence. */
3009 conv = build_conv
3016 /* Remember that this was a list-initialization. */
3020 /* Combine it with the second conversion sequence. */
3028 }
3030 tree
3032 {
3037 {
3042 }
3044 }
3046 /* Do any initial processing on the arguments to a function call. */
3050 {
3052 tree arg;
3055 {
3059 {
3062 }
3065 }
3067 }
3069 /* Perform overload resolution on FN, which is called with the ARGS.
3071 Return the candidate function selected by overload resolution, or
3072 NULL if the event that overload resolution failed. In the case
3073 that overload resolution fails, *CANDIDATES will be the set of
3074 candidates considered, and ANY_VIABLE_P will be set to true or
3075 false to indicate whether or not any of the candidates were
3076 viable.
3078 The ARGS should already have gone through RESOLVE_ARGS before this
3079 function is called. */
3086 {
3094 /* Check FN. */
3101 {
3105 }
3107 /* Add the various candidate functions. */
3112 LOOKUP_NORMAL,
3113 candidates);
3121 }
3123 /* Return an expression for a call to FN (a namespace-scope function,
3124 or a static member function) with the ARGS. This may change
3125 ARGS. */
3127 tree
3129 tsubst_flags_t complain)
3130 {
3134 tree result;
3137 {
3141 }
3143 /* If this function was found without using argument dependent
3144 lookup, then we want to ignore any undeclared friend
3145 functions. */
3147 {
3152 {
3158 }
3159 }
3161 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3167 {
3169 {
3177 else
3182 }
3184 }
3185 else
3188 /* Free all the conversions we allocated. */
3192 }
3194 /* Build a call to a global operator new. FNNAME is the name of the
3195 operator (either "operator new" or "operator new[]") and ARGS are
3196 the arguments provided. This may change ARGS. *SIZE points to the
3197 total number of bytes required by the allocation, and is updated if
3198 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3199 be used. If this function determines that no cookie should be
3200 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3201 non-NULL, it will be set, upon return, to the allocation function
3202 called. */
3204 tree
3208 {
3209 tree fns;
3221 /* Based on:
3223 [expr.new]
3225 If this lookup fails to find the name, or if the allocated type
3226 is not a class type, the allocation function's name is looked
3227 up in the global scope.
3229 we disregard block-scope declarations of "operator new". */
3232 /* Figure out what function is being called. */
3235 /* If no suitable function could be found, issue an error message
3236 and give up. */
3238 {
3242 else
3248 }
3250 /* If a cookie is required, add some extra space. Whether
3251 or not a cookie is required cannot be determined until
3252 after we know which function was called. */
3254 {
3257 {
3258 /* In G++ 3.2, the check was implemented incorrectly; it
3259 looked at the placement expression, rather than the
3260 type of the function. */
3263 ptr_type_node))
3265 }
3266 else
3267 {
3268 tree arg_types;
3271 /* Skip the size_t parameter. */
3273 /* Check the remaining parameters (if any). */
3277 ptr_type_node))
3279 }
3280 /* If we need a cookie, adjust the number of bytes allocated. */
3282 {
3283 /* Update the total size. */
3285 /* Update the argument list to reflect the adjusted size. */
3287 }
3288 else
3290 }
3292 /* Tell our caller which function we decided to call. */
3296 /* Build the CALL_EXPR. */
3298 }
3300 /* Build a new call to operator(). This may change ARGS. */
3302 tree
3304 {
3318 {
3320 /* It's no good looking for an overloaded operator() on a
3321 pointer-to-member-function. */
3322 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3324 }
3327 {
3331 }
3332 else
3336 {
3340 }
3342 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3346 {
3354 }
3359 {
3371 {
3378 add_template_conv_candidate
3382 else
3386 }
3387 }
3391 {
3393 {
3397 }
3399 }
3400 else
3401 {
3404 {
3406 {
3410 }
3412 }
3413 /* Since cand->fn will be a type, not a function, for a conversion
3414 function, we must be careful not to unconditionally look at
3415 DECL_NAME here. */
3419 else
3420 {
3422 complain);
3425 }
3426 }
3428 /* Free all the conversions we allocated. */
3432 }
3434 static void
3437 {
3442 else
3446 {
3451 else
3461 else
3470 else
3480 else
3490 else
3493 else
3497 else
3501 }
3502 }
3504 /* Return the implicit conversion sequence that could be used to
3505 convert E1 to E2 in [expr.cond]. */
3509 {
3515 /* [expr.cond]
3517 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3518 implicitly converted (clause _conv_) to the type "reference to
3519 T2", subject to the constraint that in the conversion the
3520 reference must bind directly (_dcl.init.ref_) to E1. */
3522 {
3524 t1,
3525 e1,
3530 }
3532 /* [expr.cond]
3534 If E1 and E2 have class type, and the underlying class types are
3535 the same or one is a base class of the other: E1 can be converted
3536 to match E2 if the class of T2 is the same type as, or a base
3537 class of, the class of T1, and the cv-qualification of T2 is the
3538 same cv-qualification as, or a greater cv-qualification than, the
3539 cv-qualification of T1. If the conversion is applied, E1 is
3540 changed to an rvalue of type T2 that still refers to the original
3541 source class object (or the appropriate subobject thereof). */
3544 {
3546 {
3551 else
3554 }
3555 else
3557 }
3558 else
3559 /* [expr.cond]
3561 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3562 converted to the type that expression E2 would have if E2 were
3563 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3565 LOOKUP_IMPLICIT);
3566 }
3568 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3569 arguments to the conditional expression. */
3571 tree
3573 tsubst_flags_t complain)
3574 {
3575 tree arg2_type;
3576 tree arg3_type;
3578 tree result_save;
3585 /* As a G++ extension, the second argument to the conditional can be
3586 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3587 c'.) If the second operand is omitted, make sure it is
3588 calculated only once. */
3590 {
3595 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3598 else
3600 }
3602 /* [expr.cond]
3604 The first expression is implicitly converted to bool (clause
3605 _conv_). */
3607 LOOKUP_NORMAL);
3609 /* If something has already gone wrong, just pass that fact up the
3610 tree. */
3616 /* [expr.cond]
3618 If either the second or the third operand has type (possibly
3619 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3620 array-to-pointer (_conv.array_), and function-to-pointer
3621 (_conv.func_) standard conversions are performed on the second
3622 and third operands. */
3626 {
3627 /* Do the conversions. We don't these for `void' type arguments
3628 since it can't have any effect and since decay_conversion
3629 does not handle that case gracefully. */
3637 /* [expr.cond]
3639 One of the following shall hold:
3641 --The second or the third operand (but not both) is a
3642 throw-expression (_except.throw_); the result is of the
3643 type of the other and is an rvalue.
3645 --Both the second and the third operands have type void; the
3646 result is of type void and is an rvalue.
3648 We must avoid calling force_rvalue for expressions of type
3649 "void" because it will complain that their value is being
3650 used. */
3653 {
3658 }
3661 {
3666 }
3669 else
3670 {
3672 {
3675 "is of type %<void%>, "
3676 "but the third operand is neither a throw-expression "
3678 else
3680 "is of type %<void%>, "
3681 "but the second operand is neither a throw-expression "
3683 }
3685 }
3689 }
3690 /* [expr.cond]
3692 Otherwise, if the second and third operand have different types,
3693 and either has (possibly cv-qualified) class type, an attempt is
3694 made to convert each of those operands to the type of the other. */
3697 {
3701 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3707 /* [expr.cond]
3709 If both can be converted, or one can be converted but the
3710 conversion is ambiguous, the program is ill-formed. If
3711 neither can be converted, the operands are left unchanged and
3712 further checking is performed as described below. If exactly
3713 one conversion is possible, that conversion is applied to the
3714 chosen operand and the converted operand is used in place of
3715 the original operand for the remainder of this section. */
3720 {
3724 }
3726 {
3730 /* Even if CONV2 is a valid conversion, the result of the
3731 conversion may be invalid. For example, if ARG3 has type
3732 "volatile X", and X does not have a copy constructor
3733 accepting a "volatile X&", then even if ARG2 can be
3734 converted to X, the conversion will fail. */
3737 }
3739 {
3745 }
3747 /* Free all the conversions we allocated. */
3753 /* If, after the conversion, both operands have class type,
3754 treat the cv-qualification of both operands as if it were the
3755 union of the cv-qualification of the operands.
3757 The standard is not clear about what to do in this
3758 circumstance. For example, if the first operand has type
3759 "const X" and the second operand has a user-defined
3760 conversion to "volatile X", what is the type of the second
3761 operand after this step? Making it be "const X" (matching
3762 the first operand) seems wrong, as that discards the
3763 qualification without actually performing a copy. Leaving it
3764 as "volatile X" seems wrong as that will result in the
3765 conditional expression failing altogether, even though,
3766 according to this step, the one operand could be converted to
3767 the type of the other. */
3775 }
3777 /* [expr.cond]
3779 If the second and third operands are lvalues and have the same
3780 type, the result is of that type and is an lvalue. */
3784 {
3787 }
3789 /* [expr.cond]
3791 Otherwise, the result is an rvalue. If the second and third
3792 operand do not have the same type, and either has (possibly
3793 cv-qualified) class type, overload resolution is used to
3794 determine the conversions (if any) to be applied to the operands
3795 (_over.match.oper_, _over.built_). */
3799 {
3804 /* Rearrange the arguments so that add_builtin_candidate only has
3805 to know about two args. In build_builtin_candidate, the
3806 arguments are unscrambled. */
3811 COND_EXPR,
3812 NOP_EXPR,
3814 args,
3815 LOOKUP_NORMAL);
3817 /* [expr.cond]
3819 If the overload resolution fails, the program is
3820 ill-formed. */
3823 {
3825 {
3828 }
3830 }
3833 {
3835 {
3838 }
3840 }
3842 /* [expr.cond]
3844 Otherwise, the conversions thus determined are applied, and
3845 the converted operands are used in place of the original
3846 operands for the remainder of this section. */
3855 }
3857 /* [expr.cond]
3859 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3860 and function-to-pointer (_conv.func_) standard conversions are
3861 performed on the second and third operands.
3863 We need to force the lvalue-to-rvalue conversion here for class types,
3864 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3865 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3866 regions. */
3879 /* [expr.cond]
3881 After those conversions, one of the following shall hold:
3883 --The second and third operands have the same type; the result is of
3884 that type. */
3887 /* [expr.cond]
3889 --The second and third operands have arithmetic or enumeration
3890 type; the usual arithmetic conversions are performed to bring
3891 them to a common type, and the result is of that type. */
3896 {
3897 /* In this case, there is always a common type. */
3899 arg3_type);
3903 {
3908 }
3914 {
3918 }
3922 }
3923 /* [expr.cond]
3925 --The second and third operands have pointer type, or one has
3926 pointer type and the other is a null pointer constant; pointer
3927 conversions (_conv.ptr_) and qualification conversions
3928 (_conv.qual_) are performed to bring them to their composite
3929 pointer type (_expr.rel_). The result is of the composite
3930 pointer type.
3932 --The second and third operands have pointer to member type, or
3933 one has pointer to member type and the other is a null pointer
3934 constant; pointer to member conversions (_conv.mem_) and
3935 qualification conversions (_conv.qual_) are performed to bring
3936 them to a common type, whose cv-qualification shall match the
3937 cv-qualification of either the second or the third operand.
3938 The result is of the common type. */
3946 {
3949 complain);
3954 }
3957 {
3962 }
3964 valid_operands:
3969 /* Avoid folding to a CALL_EXPR within decltype (c++/42013). */
3972 /* We can't use result_type below, as fold might have returned a
3973 throw_expr. */
3976 {
3977 /* Expand both sides into the same slot, hopefully the target of
3978 the ?: expression. We used to check for TARGET_EXPRs here,
3979 but now we sometimes wrap them in NOP_EXPRs so the test would
3980 fail. */
3983 /* If this expression is an rvalue, but might be mistaken for an
3984 lvalue, we must add a NON_LVALUE_EXPR. */
3986 }
3989 }
3991 /* OPERAND is an operand to an expression. Perform necessary steps
3992 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3993 returned. */
3995 static tree
3997 {
3999 {
4002 /* Make sure the template type is instantiated now. */
4004 }
4007 }
4009 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4010 OVERLOAD) to the CANDIDATES, returning an updated list of
4011 CANDIDATES. The ARGS are the arguments provided to the call;
4012 if FIRST_ARG is non-null it is the implicit object argument,
4013 otherwise the first element of ARGS is used if needed. The
4014 EXPLICIT_TARGS are explicit template arguments provided.
4015 TEMPLATE_ONLY is true if only template functions should be
4016 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4017 add_function_candidate. */
4019 static void
4021 tree return_type,
4026 {
4027 tree ctype;
4031 unification_kind_t strict;
4032 tree fn;
4037 /* Precalculate special handling of constructors and conversion ops. */
4040 {
4044 /* We're doing return_type(x). */
4046 else
4047 /* We're doing x.operator return_type(). */
4049 /* [over.match.funcs] For conversion functions, the function
4050 is considered to be a member of the class of the implicit
4051 object argument for the purpose of defining the type of
4052 the implicit object parameter. */
4054 }
4055 else
4056 {
4058 {
4061 }
4062 else
4063 {
4066 }
4069 }
4073 else
4074 /* Delay creating the implicit this parameter until it is needed. */
4078 {
4079 tree fn_first_arg;
4089 /* Figure out which set of arguments to use. */
4091 {
4092 /* If this function is a non-static member and we didn't get an
4093 implicit object argument, move it out of args. */
4095 {
4097 tree arg;
4104 }
4108 }
4109 else
4110 {
4111 /* Otherwise, just use the list of arguments provided. */
4114 }
4118 fn,
4119 ctype,
4120 explicit_targs,
4121 fn_first_arg,
4122 fn_args,
4123 return_type,
4124 access_path,
4125 conversion_path,
4126 flags,
4127 strict);
4130 fn,
4131 ctype,
4132 fn_first_arg,
4133 fn_args,
4134 access_path,
4135 conversion_path,
4136 flags);
4137 }
4138 }
4140 /* Even unsigned enum types promote to signed int. We don't want to
4141 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4142 original argument and ARG is the argument after any conversions
4143 have been applied. We set TREE_NO_WARNING if we have added a cast
4144 from an unsigned enum type to a signed integer type. */
4146 static void
4148 {
4157 }
4159 tree
4162 {
4168 tree fnname;
4186 {
4190 }
4191 else
4197 {
4202 /* Use build_op_new_call and build_op_delete_call instead. */
4206 /* Use build_op_call instead. */
4213 /* These are saved for the sake of warn_logical_operator. */
4219 }
4225 /* Use build_conditional_expr instead. */
4241 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4244 /* Add namespace-scope operators to the list of functions to
4245 consider. */
4250 /* Add class-member operators to the candidate set. */
4252 {
4253 tree fns;
4257 {
4260 }
4268 }
4277 {
4280 /* For these, the built-in candidates set is empty
4281 [over.match.oper]/3. We don't want non-strict matches
4282 because exact matches are always possible with built-in
4283 operators. The built-in candidate set for COMPONENT_REF
4284 would be empty too, but since there are no such built-in
4285 operators, we accept non-strict matches for them. */
4292 }
4296 {
4298 {
4301 /* Don't try anything fancy if we're not allowed to produce
4302 errors. */
4306 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4307 distinguish between prefix and postfix ++ and
4308 operator++() was used for both, so we allow this with
4309 -fpermissive. */
4311 {
4318 }
4325 else
4331 /* The caller will deal with these. */
4341 {
4342 /* If one of the arguments of the operator represents
4343 an invalid use of member function pointer, try to report
4344 a meaningful error ... */
4349 else
4350 {
4351 /* ... Otherwise, report the more generic
4352 "no matching operator found" error */
4355 }
4356 }
4359 }
4360 }
4361 else
4362 {
4365 {
4367 {
4370 }
4372 }
4374 {
4380 else
4382 }
4383 else
4384 {
4385 /* Give any warnings we noticed during overload resolution. */
4387 {
4391 }
4393 /* Check for comparison of different enum types. */
4395 {
4407 {
4411 }
4415 }
4417 /* We need to strip any leading REF_BIND so that bitfields
4418 don't cause errors. This should not remove any important
4419 conversions, because builtins don't apply to class
4420 objects directly. */
4427 {
4428 /* We need to call warn_logical_operator before
4429 converting arg2 to a boolean_type. */
4439 }
4441 {
4446 }
4448 }
4449 }
4451 user_defined_result_ready:
4453 /* Free all the conversions we allocated. */
4459 builtin:
4465 {
4478 /* Fall through. */
4516 complain),
4517 arg2);
4519 /* The caller will deal with these. */
4527 }
4529 }
4531 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
4532 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
4534 static bool
4536 {
4537 /* A template instance is never a usual deallocation function,
4538 regardless of its signature. */
4543 /* If a class T has a member deallocation function named operator delete
4544 with exactly one parameter, then that function is a usual
4545 (non-placement) deallocation function. If class T does not declare
4546 such an operator delete but does declare a member deallocation
4547 function named operator delete with exactly two parameters, the second
4548 of which has type std::size_t (18.2), then this function is a usual
4549 deallocation function. */
4556 }
4558 /* Build a call to operator delete. This has to be handled very specially,
4559 because the restrictions on what signatures match are different from all
4560 other call instances. For a normal delete, only a delete taking (void *)
4561 or (void *, size_t) is accepted. For a placement delete, only an exact
4562 match with the placement new is accepted.
4564 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4565 ADDR is the pointer to be deleted.
4566 SIZE is the size of the memory block to be deleted.
4567 GLOBAL_P is true if the delete-expression should not consider
4568 class-specific delete operators.
4569 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4571 If this call to "operator delete" is being generated as part to
4572 deallocate memory allocated via a new-expression (as per [expr.new]
4573 which requires that if the initialization throws an exception then
4574 we call a deallocation function), then ALLOC_FN is the allocation
4575 function. */
4577 tree
4580 tree alloc_fn)
4581 {
4595 /* In [class.free]
4597 If the result of the lookup is ambiguous or inaccessible, or if
4598 the lookup selects a placement deallocation function, the
4599 program is ill-formed.
4601 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4602 {
4606 }
4607 else
4613 /* Strip const and volatile from addr. */
4617 {
4618 /* "A declaration of a placement deallocation function matches the
4619 declaration of a placement allocation function if it has the same
4620 number of parameters and, after parameter transformations (8.3.5),
4621 all parameter types except the first are identical."
4623 So we build up the function type we want and ask instantiate_type
4624 to get it for us. */
4636 /* "If the lookup finds the two-parameter form of a usual deallocation
4637 function (3.7.4.2) and that function, considered as a placement
4638 deallocation function, would have been selected as a match for the
4639 allocation function, the program is ill-formed." */
4641 {
4642 /* But if the class has an operator delete (void *), then that is
4643 the usual deallocation function, so we shouldn't complain
4644 about using the operator delete (void *, size_t). */
4647 {
4652 }
4655 ok:;
4656 }
4657 }
4658 else
4659 /* "Any non-placement deallocation function matches a non-placement
4660 allocation function. If the lookup finds a single matching
4661 deallocation function, that function will be called; otherwise, no
4662 deallocation function will be called." */
4665 {
4668 {
4670 /* "If a class T has a member deallocation function named
4671 operator delete with exactly one parameter, then that
4672 function is a usual (non-placement) deallocation
4673 function. If class T does not declare such an operator
4674 delete but does declare a member deallocation function named
4675 operator delete with exactly two parameters, the second of
4676 which has type std::size_t (18.2), then this function is a
4677 usual deallocation function."
4679 So (void*) beats (void*, size_t). */
4682 }
4683 }
4685 /* If we have a matching function, call it. */
4687 {
4690 /* If the FN is a member function, make sure that it is
4691 accessible. */
4695 /* Core issue 901: It's ok to new a type with deleted delete. */
4700 {
4701 /* The placement args might not be suitable for overload
4702 resolution at this point, so build the call directly. */
4711 }
4712 else
4713 {
4714 tree ret;
4722 }
4723 }
4725 /* [expr.new]
4727 If no unambiguous matching deallocation function can be found,
4728 propagating the exception does not cause the object's memory to
4729 be freed. */
4731 {
4734 alloc_fn);
4736 }
4741 }
4743 /* If the current scope isn't allowed to access DECL along
4744 BASETYPE_PATH, give an error. The most derived class in
4745 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4746 the declaration to use in the error diagnostic. */
4748 bool
4750 {
4754 {
4759 else
4763 }
4766 }
4768 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4769 bitwise or of LOOKUP_* values. If any errors are warnings are
4770 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4771 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4772 to NULL. */
4774 static tree
4777 {
4790 else
4793 }
4795 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4796 EXPR is implicitly converted to type TOTYPE.
4797 FN and ARGNUM are used for diagnostics. */
4799 static void
4801 {
4804 /* Issue warnings about peculiar, but valid, uses of NULL. */
4806 {
4811 else
4814 }
4816 /* Issue warnings if "false" is converted to a NULL pointer */
4821 }
4823 /* Perform the conversions in CONVS on the expression EXPR. FN and
4824 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4825 indicates the `this' argument of a method. INNER is nonzero when
4826 being called to continue a conversion chain. It is negative when a
4827 reference binding will be applied, positive otherwise. If
4828 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4829 conversions will be emitted if appropriate. If C_CAST_P is true,
4830 this conversion is coming from a C-style cast; in that case,
4831 conversions to inaccessible bases are permitted. */
4833 static tree
4837 {
4839 diagnostic_t diag_kind;
4849 {
4852 /* Give a helpful error if this is bad because of excess braces. */
4860 {
4862 {
4866 complain);
4868 }
4873 complain);
4876 }
4878 {
4882 }
4883 else
4887 }
4893 {
4895 {
4902 /* When converting from an init list we consider explicit
4903 constructors, but actually trying to call one is an error. */
4905 {
4909 else
4911 }
4913 /* Set user_conv_p on the argument conversions, so rvalue/base
4914 handling knows not to allow any more UDCs. */
4920 /* If this is a constructor or a function returning an aggr type,
4921 we need to build up a TARGET_EXPR. */
4923 {
4926 /* Remember that this was list-initialization. */
4929 }
4932 }
4936 {
4942 else
4944 }
4948 /* Convert a constant to its underlying value, unless we are
4949 about to bind it to a reference, in which case we need to
4950 leave it as an lvalue. */
4952 {
4955 /* If __null has been converted to an integer type, we do not
4956 want to warn about uses of EXPR as an integer, rather than
4957 as a pointer. */
4959 }
4964 /* Call build_user_type_conversion again for the error. */
4965 return build_user_type_conversion
4969 {
4970 /* Conversion to std::initializer_list<T>. */
4978 /* Convert all the elements. */
4980 {
4987 }
4988 /* Build up the array. */
4989 elttype = cp_build_qualified_type
4997 /* Call the private constructor. */
4999 new_ctor = build_special_member_call
5004 }
5011 };
5016 c_cast_p,
5017 complain);
5022 {
5027 /* Else fall through. */
5030 {
5031 /* We are going to bind a reference directly to a base-class
5032 subobject of EXPR. */
5033 /* Build an expression for `*((base*) &expr)'. */
5039 }
5041 /* Copy-initialization where the cv-unqualified version of the source
5042 type is the same class as, or a derived class of, the class of the
5043 destination [is treated as direct-initialization]. [dcl.init] */
5046 /* This conversion is being done in the context of a user-defined
5047 conversion (i.e. the second step of copy-initialization), so
5048 don't allow any more. */
5052 {
5058 }
5062 {
5067 {
5069 {
5074 }
5076 }
5078 /* If necessary, create a temporary.
5080 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5081 that need temporaries, even when their types are reference
5082 compatible with the type of reference being bound, so the
5083 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
5084 doesn't fail. */
5088 {
5094 {
5096 {
5097 /* If the reference is volatile or non-const, we
5098 cannot create a temporary. */
5105 else
5107 }
5109 }
5110 /* If the source is a packed field, and we must use a copy
5111 constructor, then building the target expr will require
5112 binding the field to the reference parameter to the
5113 copy constructor, and we'll end up with an infinite
5114 loop. If we can use a bitwise copy, then we'll be
5115 OK. */
5119 {
5124 }
5126 {
5129 }
5131 }
5133 /* Take the address of the thing to which we will bind the
5134 reference. */
5139 /* Convert it to a pointer to the type referred to by the
5140 reference. This will adjust the pointer if a derived to
5141 base conversion is being performed. */
5143 expr);
5144 /* Convert the pointer to the desired reference type. */
5146 }
5152 /* Warn about deprecated conversion if appropriate. */
5164 c_cast_p);
5168 }
5175 else
5179 }
5181 /* ARG is being passed to a varargs function. Perform any conversions
5182 required. Return the converted value. */
5184 tree
5186 {
5187 /* [expr.call]
5189 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5190 standard conversions are performed. */
5192 /* [expr.call]
5194 If the argument has integral or enumeration type that is subject
5195 to the integral promotions (_conv.prom_), or a floating point
5196 type that is subject to the floating point promotion
5197 (_conv.fpprom_), the value of the argument is converted to the
5198 promoted type before the call. */
5214 {
5215 /* [expr.call] 5.2.2/7:
5216 Passing a potentially-evaluated argument of class type (Clause 9)
5217 with a non-trivial copy constructor or a non-trivial destructor
5218 with no corresponding parameter is conditionally-supported, with
5219 implementation-defined semantics.
5221 We used to just warn here and do a bitwise copy, but now
5222 cp_expr_size will abort if we try to do that.
5224 If the call appears in the context of a sizeof expression,
5225 it is not potentially-evaluated. */
5229 }
5232 }
5234 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5236 tree
5238 {
5252 {
5253 /* Remove reference types so we don't ICE later on. */
5255 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5261 }
5264 }
5266 /* TYPE has been given to va_arg. Apply the default conversions which
5267 would have happened when passed via ellipsis. Return the promoted
5268 type, or the passed type if there is no change. */
5270 tree
5272 {
5273 tree promote;
5275 /* Perform the array-to-pointer and function-to-pointer
5276 conversions. */
5284 }
5286 /* ARG is a default argument expression being passed to a parameter of
5287 the indicated TYPE, which is a parameter to FN. Do any required
5288 conversions. Return the converted value. */
5292 tree
5294 {
5296 tree t;
5298 /* If the ARG is an unparsed default argument expression, the
5299 conversion cannot be performed. */
5301 {
5306 }
5308 /* Detect recursion. */
5311 {
5314 }
5320 /* Due to:
5322 [dcl.fct.default]
5324 The names in the expression are bound, and the semantic
5325 constraints are checked, at the point where the default
5326 expressions appears.
5328 we must not perform access checks here. */
5332 {
5336 tf_warning_or_error);
5337 }
5338 else
5339 {
5340 /* We must make a copy of ARG, in case subsequent processing
5341 alters any part of it. For example, during gimplification a
5342 cast of the form (T) &X::f (where "f" is a member function)
5343 will lead to replacing the PTRMEM_CST for &X::f with a
5344 VAR_DECL. We can avoid the copy for constants, since they
5345 are never modified in place. */
5350 tf_warning_or_error);
5352 }
5358 }
5360 /* Returns the type which will really be used for passing an argument of
5361 type TYPE. */
5363 tree
5365 {
5366 /* Pass classes with copy ctors by invisible reference. */
5368 {
5370 /* There are no other pointers to this temporary. */
5372 }
5381 }
5383 /* Actually perform the appropriate conversion. */
5385 tree
5387 {
5388 tree bitfield_type;
5390 /* If VAL is a bitfield, then -- since it has already been converted
5391 to TYPE -- it cannot have a precision greater than TYPE.
5393 If it has a smaller precision, we must widen it here. For
5394 example, passing "int f:3;" to a function expecting an "int" will
5395 not result in any conversion before this point.
5397 If the precision is the same we must not risk widening. For
5398 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5399 often have type "int", even though the C++ type for the field is
5400 "long long". If the value is being passed to a function
5401 expecting an "int", then no conversions will be required. But,
5402 if we call convert_bitfield_to_declared_type, the bitfield will
5403 be converted to "long long". */
5410 ;
5411 /* Pass classes with copy ctors by invisible reference. */
5421 {
5430 }
5432 }
5434 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5435 which no conversions at all should be done. This is true for some
5436 builtins which don't act like normal functions. */
5438 static bool
5440 {
5443 {
5453 }
5456 }
5458 /* Subroutine of the various build_*_call functions. Overload resolution
5459 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5460 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5461 bitmask of various LOOKUP_* flags which apply to the call itself. */
5463 static tree
5465 {
5473 tree val;
5482 /* In a template, there is no need to perform all of the work that
5483 is normally done. We are only interested in the type of the call
5484 expression, i.e., the return type of the function. Any semantic
5485 errors will be deferred until the template is instantiated. */
5487 {
5488 tree expr;
5489 tree return_type;
5497 else
5498 {
5501 tree arg;
5509 }
5512 argarray);
5518 }
5520 /* Give any warnings we noticed during overload resolution. */
5522 {
5526 }
5528 /* Make =delete work with SFINAE. */
5533 {
5534 /* If FN is a template function, two cases must be considered.
5535 For example:
5537 struct A {
5538 protected:
5539 template <class T> void f();
5540 };
5541 template <class T> struct B {
5542 protected:
5543 void g();
5544 };
5545 struct C : A, B<int> {
5546 using A::f; // #1
5547 using B<int>::g; // #2
5548 };
5550 In case #1 where `A::f' is a member template, DECL_ACCESS is
5551 recorded in the primary template but not in its specialization.
5552 We check access of FN using its primary template.
5554 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5555 because it is a member of class template B, DECL_ACCESS is
5556 recorded in the specialization `B<int>::g'. We cannot use its
5557 primary template because `B<T>::g' and `B<int>::g' may have
5558 different access. */
5563 else
5565 }
5567 /* Find maximum size of vector to hold converted arguments. */
5574 /* The implicit parameters to a constructor are not considered by overload
5575 resolution, and must be of the proper type. */
5577 {
5579 {
5582 }
5583 else
5584 {
5587 }
5589 /* We should never try to call the abstract constructor. */
5593 {
5597 }
5598 }
5599 /* Bypass access control for 'this' parameter. */
5601 {
5604 ? first_arg
5607 tree converted_arg;
5608 tree base_binfo;
5611 {
5615 else
5617 }
5619 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5620 X is called for an object that is not of type X, or of a type
5621 derived from X, the behavior is undefined.
5623 So we can assume that anything passed as 'this' is non-null, and
5624 optimize accordingly. */
5626 /* Convert to the base in which the function was declared. */
5629 arg,
5632 /* Check that the base class is accessible. */
5638 /* If fn was found by a using declaration, the conversion path
5639 will be to the derived class, not the base declaring fn. We
5640 must convert from derived to base. */
5650 else
5654 }
5659 {
5664 /* Don't make a copy here if build_call is going to. */
5670 /* Warn about initializer_list deduction that isn't currently in the
5671 working draft. */
5673 && flag_deduce_init_list
5676 {
5686 {
5693 }
5694 }
5696 val = convert_like_with_context
5698 complain);
5703 else
5705 }
5707 /* Default arguments */
5712 /* Ellipsis */
5714 {
5717 /* Do no conversions for magic varargs. */
5719 else
5722 }
5730 /* Avoid actually calling copy constructors and copy assignment operators,
5731 if possible. */
5738 {
5739 tree targ;
5741 tree fa;
5743 /* Pull out the real argument, disregarding const-correctness. */
5749 {
5754 }
5755 else
5760 else
5765 {
5766 /* Copy-list-initialization doesn't require the copy constructor
5767 to be defined. */
5768 }
5769 /* [class.copy]: the copy constructor is implicitly defined even if
5770 the implementation elided its use. */
5772 {
5775 }
5777 /* If we're creating a temp and we already have one, don't create a
5778 new one. If we're not creating a temp but we get one, use
5779 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5780 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5781 temp or an INIT_EXPR otherwise. */
5786 {
5791 }
5795 {
5797 complain));
5801 }
5802 }
5806 {
5807 tree to = stabilize_reference
5814 {
5815 /* Avoid copying empty classes. */
5820 }
5822 {
5825 }
5826 else
5827 {
5828 /* We must only copy the non-tail padding parts.
5829 Use __builtin_memcpy for the bitwise copy.
5830 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5831 instead of an explicit call to memcpy. */
5841 {
5842 /* If we can't be sure about pointer alignment, a call
5843 to __builtin_memcpy is expanded as a call to memcpy, which
5844 is invalid with identical args. Otherwise it is
5845 expanded as a block move, which should be safe. */
5849 }
5858 }
5861 }
5867 {
5868 tree t;
5874 /* Warn about deprecated virtual functions now, since we're about
5875 to throw away the decl. */
5885 else
5888 }
5889 else
5893 }
5895 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5896 This function performs no overload resolution, conversion, or other
5897 high-level operations. */
5899 tree
5901 {
5902 tree fndecl;
5906 /* If this call might throw an exception, note that fact. */
5913 /* Check that arguments to builtin functions match the expectations. */
5920 /* Some built-in function calls will be evaluated at compile-time in
5921 fold (). */
5934 }
5938 /* Make an expression which yields the address of the Java interface
5939 method FN. This is achieved by generating a call to libjava's
5940 _Jv_LookupInterfaceMethodIdx(). */
5942 static tree
5944 {
5950 {
5955 endlink)));
5956 java_iface_lookup_fn
5960 }
5962 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5963 This is the first entry in the vtable. */
5965 tf_warning_or_error),
5966 integer_zero_node);
5968 /* Get the java.lang.Class pointer for the interface being called. */
5973 {
5975 iface);
5977 }
5981 /* Determine the itable index of FN. */
5984 {
5989 i++;
5990 }
5995 java_iface_lookup_fn);
5998 }
6000 /* Returns the value to use for the in-charge parameter when making a
6001 call to a function with the indicated NAME.
6003 FIXME:Can't we find a neater way to do this mapping? */
6005 tree
6007 {
6018 /* This function should only be called with one of the names listed
6019 above. */
6022 }
6024 /* Build a call to a constructor, destructor, or an assignment
6025 operator for INSTANCE, an expression with class type. NAME
6026 indicates the special member function to call; *ARGS are the
6027 arguments. ARGS may be NULL. This may change ARGS. BINFO
6028 indicates the base of INSTANCE that is to be passed as the `this'
6029 parameter to the member function called.
6031 FLAGS are the LOOKUP_* flags to use when processing the call.
6033 If NAME indicates a complete object constructor, INSTANCE may be
6034 NULL_TREE. In this case, the caller will call build_cplus_new to
6035 store the newly constructed object into a VAR_DECL. */
6037 tree
6040 {
6041 tree fns;
6042 /* The type of the subobject to be constructed or destroyed. */
6043 tree class_type;
6045 tree ret;
6054 {
6055 /* Resolve the name. */
6060 }
6066 /* Handle the special case where INSTANCE is NULL_TREE. */
6068 {
6071 }
6072 else
6073 {
6079 /* Convert to the base class, if necessary. */
6082 {
6084 /* For constructors and destructors, either the base is
6085 non-virtual, or it is virtual but we are doing the
6086 conversion from a constructor or destructor for the
6087 complete object. In either case, we can convert
6088 statically. */
6090 else
6091 /* However, for assignment operators, we must convert
6092 dynamically if the base is virtual. */
6095 }
6096 }
6102 /* When making a call to a constructor or destructor for a subobject
6103 that uses virtual base classes, pass down a pointer to a VTT for
6104 the subobject. */
6108 {
6109 tree vtt;
6110 tree sub_vtt;
6112 /* If the current function is a complete object constructor
6113 or destructor, then we fetch the VTT directly.
6114 Otherwise, we look it up using the VTT we were given. */
6120 current_vtt_parm,
6121 vtt);
6127 {
6130 }
6133 }
6138 complain);
6144 }
6146 /* Return the NAME, as a C string. The NAME indicates a function that
6147 is a member of TYPE. *FREE_P is set to true if the caller must
6148 free the memory returned.
6150 Rather than go through all of this, we should simply set the names
6151 of constructors and destructors appropriately, and dispense with
6152 ctor_identifier, dtor_identifier, etc. */
6156 {
6159 /* Assume that we will not allocate memory. */
6161 /* Constructors and destructors are special. */
6163 {
6164 pretty_name
6166 /* For a destructor, add the '~'. */
6170 {
6172 /* Remember that we need to free the memory allocated. */
6174 }
6175 }
6177 {
6180 TFF_PLAIN_IDENTIFIER),
6181 NULL);
6182 /* Remember that we need to free the memory allocated. */
6184 }
6185 else
6189 }
6191 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6192 be set, upon return, to the function called. ARGS may be NULL.
6193 This may change ARGS. */
6195 tree
6199 {
6203 tree access_binfo;
6204 tree optype;
6206 tree instance_ptr;
6207 tree name;
6210 tree call;
6211 tree fn;
6214 tree orig_instance;
6215 tree orig_fns;
6223 /* We don't know what function we're going to call, yet. */
6232 {
6236 }
6241 /* Dismantle the baselink to collect all the information we need. */
6248 {
6252 }
6263 {
6268 }
6271 /* Under DR 147 A::A() is an invalid constructor call,
6272 not a functional cast. */
6274 {
6284 complain);
6286 }
6288 /* Figure out whether to skip the first argument for the error
6289 message we will display to users if an error occurs. We don't
6290 want to display any compiler-generated arguments. The "this"
6291 pointer hasn't been added yet. However, we must remove the VTT
6292 pointer if this is a call to a base-class constructor or
6293 destructor. */
6296 {
6297 /* Callers should explicitly indicate whether they want to construct
6298 the complete object or just the part without virtual bases. */
6300 /* Similarly for destructors. */
6302 /* Remove the VTT pointer, if present. */
6306 }
6308 /* Process the argument list. */
6310 {
6314 }
6318 /* It's OK to call destructors and constructors on cv-qualified objects.
6319 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6320 necessary. */
6323 {
6327 }
6331 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6332 initializer, not T({ }). If the type doesn't have a list ctor (or no
6333 viable list ctor), break apart the list into separate ctor args. */
6338 {
6344 else
6346 }
6350 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6355 {
6360 }
6363 {
6370 }
6373 {
6375 {
6382 else
6383 {
6386 tree arglist;
6397 }
6399 }
6401 }
6402 else
6403 {
6406 {
6409 tree arglist;
6412 {
6418 arglist);
6422 }
6424 }
6425 else
6426 {
6435 /* This is not an error, it is runtime undefined
6436 behavior. */
6438 "abstract virtual %q#D called from constructor"
6440 fn);
6444 {
6447 fn);
6449 }
6450 else
6451 {
6455 /* Now we know what function is being called. */
6458 /* Build the actual CALL_EXPR. */
6460 /* In an expression of the form `a->f()' where `f' turns
6461 out to be a static member function, `a' is
6462 none-the-less evaluated. */
6471 /* An explicit call of the form "x->~X()" has type
6472 "void". However, on platforms where destructors
6473 return "this" (i.e., those where
6474 targetm.cxx.cdtor_returns_this is true), such calls
6475 will appear to have a return value of pointer type
6476 to the low-level call machinery. We do not want to
6477 change the low-level machinery, since we want to be
6478 able to optimize "delete f()" on such platforms as
6479 "operator delete(~X(f()))" (rather than generating
6480 "t = f(), ~X(t), operator delete (t)"). */
6482 }
6483 }
6484 }
6487 {
6493 {
6496 }
6499 call = (build_min_non_dep_call_vec
6503 orig_args));
6507 }
6509 /* Free all the conversions we allocated. */
6516 }
6518 /* Returns true iff standard conversion sequence ICS1 is a proper
6519 subsequence of ICS2. */
6521 static bool
6523 {
6524 /* We can assume that a conversion of the same code
6525 between the same types indicates a subsequence since we only get
6526 here if the types we are converting from are the same. */
6533 {
6541 /* At this point, ICS1 cannot be a proper subsequence of
6542 ICS2. We can get a USER_CONV when we are comparing the
6543 second standard conversion sequence of two user conversion
6544 sequences. */
6554 }
6555 }
6557 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6558 be any _TYPE nodes. */
6560 bool
6562 {
6566 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6567 considers every class derived from itself. */
6570 }
6572 /* We build the ICS for an implicit object parameter as a pointer
6573 conversion sequence. However, such a sequence should be compared
6574 as if it were a reference conversion sequence. If ICS is the
6575 implicit conversion sequence for an implicit object parameter,
6576 modify it accordingly. */
6578 static void
6580 {
6582 {
6583 /* [over.match.funcs]
6585 For non-static member functions, the type of the
6586 implicit object parameter is "reference to cv X"
6587 where X is the class of which the function is a
6588 member and cv is the cv-qualification on the member
6589 function declaration. */
6591 tree reference_type;
6593 /* The `this' parameter is a pointer to a class type. Make the
6594 implicit conversion talk about a reference to that same class
6595 type. */
6608 }
6609 }
6611 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6612 and return the initial reference binding conversion. Otherwise,
6613 leave *ICS unchanged and return NULL. */
6617 {
6619 {
6624 }
6627 }
6629 /* Compare two implicit conversion sequences according to the rules set out in
6630 [over.ics.rank]. Return values:
6632 1: ics1 is better than ics2
6633 -1: ics2 is better than ics1
6634 0: ics1 and ics2 are indistinguishable */
6636 static int
6638 {
6639 tree from_type1;
6640 tree from_type2;
6641 tree to_type1;
6642 tree to_type2;
6649 /* REF_BINDING is nonzero if the result of the conversion sequence
6650 is a reference type. In that case REF_CONV is the reference
6651 binding conversion. */
6655 /* Handle implicit object parameters. */
6659 /* Handle reference parameters. */
6663 /* List-initialization sequence L1 is a better conversion sequence than
6664 list-initialization sequence L2 if L1 converts to
6665 std::initializer_list<X> for some X and L2 does not. */
6671 /* [over.ics.rank]
6673 When comparing the basic forms of implicit conversion sequences (as
6674 defined in _over.best.ics_)
6676 --a standard conversion sequence (_over.ics.scs_) is a better
6677 conversion sequence than a user-defined conversion sequence
6678 or an ellipsis conversion sequence, and
6680 --a user-defined conversion sequence (_over.ics.user_) is a
6681 better conversion sequence than an ellipsis conversion sequence
6682 (_over.ics.ellipsis_). */
6692 {
6693 /* XXX Isn't this an extension? */
6694 /* Both ICS are bad. We try to make a decision based on what
6695 would have happened if they'd been good. */
6703 /* We couldn't make up our minds; try to figure it out below. */
6704 }
6707 /* Both conversions are ellipsis conversions or both are building a
6708 std::initializer_list. */
6711 /* User-defined conversion sequence U1 is a better conversion sequence
6712 than another user-defined conversion sequence U2 if they contain the
6713 same user-defined conversion operator or constructor and if the sec-
6714 ond standard conversion sequence of U1 is better than the second
6715 standard conversion sequence of U2. */
6718 {
6732 /* We can just fall through here, after setting up
6733 FROM_TYPE1 and FROM_TYPE2. */
6736 }
6737 else
6738 {
6742 /* We're dealing with two standard conversion sequences.
6744 [over.ics.rank]
6746 Standard conversion sequence S1 is a better conversion
6747 sequence than standard conversion sequence S2 if
6749 --S1 is a proper subsequence of S2 (comparing the conversion
6750 sequences in the canonical form defined by _over.ics.scs_,
6751 excluding any Lvalue Transformation; the identity
6752 conversion sequence is considered to be a subsequence of
6753 any non-identity conversion sequence */
6764 }
6766 /* One sequence can only be a subsequence of the other if they start with
6767 the same type. They can start with different types when comparing the
6768 second standard conversion sequence in two user-defined conversion
6769 sequences. */
6771 {
6776 }
6778 /* [over.ics.rank]
6780 Or, if not that,
6782 --the rank of S1 is better than the rank of S2 (by the rules
6783 defined below):
6785 Standard conversion sequences are ordered by their ranks: an Exact
6786 Match is a better conversion than a Promotion, which is a better
6787 conversion than a Conversion.
6789 Two conversion sequences with the same rank are indistinguishable
6790 unless one of the following rules applies:
6792 --A conversion that does not a convert a pointer, pointer to member,
6793 or std::nullptr_t to bool is better than one that does.
6795 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
6796 so that we do not have to check it explicitly. */
6805 /* A conversion from scalar arithmetic type to complex is worse than a
6806 conversion between scalar arithmetic types. */
6813 {
6816 else
6818 }
6824 {
6829 }
6830 /* The rules for pointers to members A::* are just like the rules
6831 for pointers A*, except opposite: if B is derived from A then
6832 A::* converts to B::*, not vice versa. For that reason, we
6833 switch the from_ and to_ variables here. */
6840 {
6845 }
6850 {
6851 /* This was one of the pointer or pointer-like conversions.
6853 [over.ics.rank]
6855 --If class B is derived directly or indirectly from class A,
6856 conversion of B* to A* is better than conversion of B* to
6857 void*, and conversion of A* to void* is better than
6858 conversion of B* to void*. */
6861 {
6863 deref_from_type2))
6866 deref_from_type1))
6868 }
6871 {
6873 {
6875 {
6877 deref_to_type1))
6879 }
6880 /* We know that DEREF_TO_TYPE1 is `void' here. */
6882 deref_to_type2))
6884 }
6885 }
6888 {
6889 /* [over.ics.rank]
6891 --If class B is derived directly or indirectly from class A
6892 and class C is derived directly or indirectly from B,
6894 --conversion of C* to B* is better than conversion of C* to
6895 A*,
6897 --conversion of B* to A* is better than conversion of C* to
6898 A* */
6900 {
6902 deref_to_type2))
6905 deref_to_type1))
6907 }
6909 {
6911 deref_from_type1))
6914 deref_from_type2))
6916 }
6917 }
6918 }
6921 {
6924 /* [over.ics.rank]
6926 --binding of an expression of type C to a reference of type
6927 B& is better than binding an expression of type C to a
6928 reference of type A&
6930 --conversion of C to B is better than conversion of C to A, */
6933 {
6938 }
6939 }
6942 {
6945 /* [over.ics.rank]
6947 --binding of an expression of type B to a reference of type
6948 A& is better than binding an expression of type C to a
6949 reference of type A&,
6951 --conversion of B to A is better than conversion of C to A */
6954 {
6959 }
6960 }
6962 /* [over.ics.rank]
6964 --S1 and S2 differ only in their qualification conversion and yield
6965 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6966 qualification signature of type T1 is a proper subset of the cv-
6967 qualification signature of type T2 */
6971 {
6975 }
6977 /* [over.ics.rank]
6979 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6980 to an implicit object parameter, and either S1 binds an lvalue reference
6981 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6982 reference to an rvalue and S2 binds an lvalue reference
6983 (C++0x draft standard, 13.3.3.2)
6985 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6986 types to which the references refer are the same type except for
6987 top-level cv-qualifiers, and the type to which the reference
6988 initialized by S2 refers is more cv-qualified than the type to
6989 which the reference initialized by S1 refers */
6992 {
6996 {
7001 }
7006 }
7008 /* Neither conversion sequence is better than the other. */
7010 }
7012 /* The source type for this standard conversion sequence. */
7014 static tree
7016 {
7018 {
7023 }
7025 }
7027 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7028 a pointer to LOSER and re-running joust to produce the warning if WINNER
7029 is actually used. */
7031 static void
7033 {
7039 }
7041 /* Compare two candidates for overloading as described in
7042 [over.match.best]. Return values:
7044 1: cand1 is better than cand2
7045 -1: cand2 is better than cand1
7046 0: cand1 and cand2 are indistinguishable */
7048 static int
7050 {
7056 /* Candidates that involve bad conversions are always worse than those
7057 that don't. */
7063 /* If we have two pseudo-candidates for conversions to the same type,
7064 or two candidates for the same function, arbitrarily pick one. */
7069 /* a viable function F1
7070 is defined to be a better function than another viable function F2 if
7071 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7072 ICSi(F2), and then */
7074 /* for some argument j, ICSj(F1) is a better conversion sequence than
7075 ICSj(F2) */
7077 /* For comparing static and non-static member functions, we ignore
7078 the implicit object parameter of the non-static function. The
7079 standard says to pretend that the static function has an object
7080 parm, but that won't work with operator overloading. */
7083 {
7091 else
7092 {
7095 }
7096 }
7099 {
7105 {
7118 {
7125 else
7130 {
7134 }
7135 else
7137 }
7140 {
7143 }
7145 }
7146 }
7148 /* warn about confusing overload resolution for user-defined conversions,
7149 either between a constructor and a conversion op, or between two
7150 conversion ops. */
7154 {
7160 else
7163 /* We don't want to complain about `X::operator T1 ()'
7164 beating `X::operator T2 () const', when T2 is a no less
7165 cv-qualified version of T1. */
7168 {
7173 {
7176 }
7179 }
7180 else
7186 {
7193 {
7195 }
7196 }
7197 else
7199 }
7204 /* or, if not that,
7205 F1 is a non-template function and F2 is a template function
7206 specialization. */
7213 /* or, if not that,
7214 F1 and F2 are template functions and the function template for F1 is
7215 more specialized than the template for F2 according to the partial
7216 ordering rules. */
7219 {
7220 winner = more_specialized_fn
7223 /* [temp.func.order]: The presence of unused ellipsis and default
7224 arguments has no effect on the partial ordering of function
7225 templates. add_function_candidate() will not have
7226 counted the "this" argument for constructors. */
7230 }
7232 /* or, if not that,
7233 the context is an initialization by user-defined conversion (see
7234 _dcl.init_ and _over.match.user_) and the standard conversion
7235 sequence from the return type of F1 to the destination type (i.e.,
7236 the type of the entity being initialized) is a better conversion
7237 sequence than the standard conversion sequence from the return type
7238 of F2 to the destination type. */
7241 {
7245 }
7247 /* Check whether we can discard a builtin candidate, either because we
7248 have two identical ones or matching builtin and non-builtin candidates.
7250 (Pedantically in the latter case the builtin which matched the user
7251 function should not be added to the overload set, but we spot it here.
7253 [over.match.oper]
7254 ... the builtin candidates include ...
7255 - do not have the same parameter type list as any non-template
7256 non-member candidate. */
7260 {
7266 {
7268 /* Two built-in candidates; arbitrarily pick one. */
7271 /* cand1 is built-in; prefer cand2. */
7273 else
7274 /* cand2 is built-in; prefer cand1. */
7276 }
7277 }
7279 /* If the two function declarations represent the same function (this can
7280 happen with declarations in multiple scopes and arg-dependent lookup),
7281 arbitrarily choose one. But first make sure the default args we're
7282 using match. */
7285 {
7292 {
7293 /* Don't crash if the fn is variadic. */
7298 }
7306 {
7309 {
7311 {
7318 }
7319 else
7322 }
7325 }
7328 }
7330 tweak:
7332 /* Extension: If the worst conversion for one candidate is worse than the
7333 worst conversion for the other, take the first. */
7335 {
7340 {
7345 }
7351 {
7353 {
7355 "ISO C++ says that these are ambiguous, even "
7356 "though the worst conversion for the first is better than "
7360 }
7361 else
7364 }
7365 }
7369 }
7371 /* Given a list of candidates for overloading, find the best one, if any.
7372 This algorithm has a worst case of O(2n) (winner is last), and a best
7373 case of O(n/2) (totally ambiguous); much better than a sorting
7374 algorithm. */
7378 {
7383 /* Walk through the list once, comparing each current champ to the next
7384 candidate, knocking out a candidate or two with each comparison. */
7387 {
7391 else
7392 {
7394 {
7399 }
7400 else
7401 {
7404 }
7407 }
7408 }
7410 /* Make sure the champ is better than all the candidates it hasn't yet
7411 been compared to. */
7414 challenger != champ
7417 {
7421 }
7424 }
7426 /* Returns nonzero if things of type FROM can be converted to TO. */
7428 bool
7430 {
7432 }
7434 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7436 bool
7438 {
7443 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7447 flags);
7450 /* Free all the conversions we allocated. */
7454 }
7456 /* Like can_convert_arg, but allows dubious conversions as well. */
7458 bool
7460 {
7464 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7466 /* Try to perform the conversion. */
7468 flags);
7469 /* Free all the conversions we allocated. */
7473 }
7475 /* Convert EXPR to TYPE. Return the converted expression.
7477 Note that we allow bad conversions here because by the time we get to
7478 this point we are committed to doing the conversion. If we end up
7479 doing a bad conversion, convert_like will complain. */
7481 tree
7483 {
7490 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7495 flags);
7498 {
7500 {
7501 /* If expr has unknown type, then it is an overloaded function.
7502 Call instantiate_type to get good error messages. */
7507 else
7509 }
7511 }
7513 {
7514 /* In a template, we are only concerned about determining the
7515 type of non-dependent expressions, so we do not have to
7516 perform the actual conversion. */
7519 }
7520 else
7523 /* Free all the conversions we allocated. */
7527 }
7529 tree
7531 {
7533 }
7535 /* Convert EXPR to TYPE (as a direct-initialization) if that is
7536 permitted. If the conversion is valid, the converted expression is
7537 returned. Otherwise, NULL_TREE is returned, except in the case
7538 that TYPE is a class type; in that case, an error is issued. If
7539 C_CAST_P is true, then this direction initialization is taking
7540 place as part of a static_cast being attempted as part of a C-style
7541 cast. */
7543 tree
7545 tree expr,
7547 tsubst_flags_t complain)
7548 {
7554 /* [dcl.init]
7556 If the destination type is a (possibly cv-qualified) class type:
7558 -- If the initialization is direct-initialization ...,
7559 constructors are considered. ... If no constructor applies, or
7560 the overload resolution is ambiguous, the initialization is
7561 ill-formed. */
7563 {
7569 }
7571 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7575 c_cast_p,
7576 LOOKUP_NORMAL);
7579 else
7582 c_cast_p,
7583 complain);
7585 /* Free all the conversions we allocated. */
7589 }
7591 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
7592 is being bound to a temporary. Create and return a new VAR_DECL
7593 with the indicated TYPE; this variable will store the value to
7594 which the reference is bound. */
7596 tree
7598 {
7599 tree var;
7601 /* Create the variable. */
7604 /* Register the variable. */
7606 {
7607 /* Namespace-scope or local static; give it a mangled name. */
7608 tree name;
7615 }
7616 else
7617 /* Create a new cleanup level if necessary. */
7621 }
7623 /* EXPR is the initializer for a variable DECL of reference or
7624 std::initializer_list type. Create, push and return a new VAR_DECL
7625 for the initializer so that it will live as long as DECL. Any
7626 cleanup for the new variable is returned through CLEANUP, and the
7627 code to initialize the new variable is returned through INITP. */
7629 tree
7631 {
7632 tree init;
7633 tree type;
7634 tree var;
7636 /* Create the temporary variable. */
7640 /* If the rvalue is the result of a function call it will be
7641 a TARGET_EXPR. If it is some other construct (such as a
7642 member access expression where the underlying object is
7643 itself the result of a function call), turn it into a
7644 TARGET_EXPR here. It is important that EXPR be a
7645 TARGET_EXPR below since otherwise the INIT_EXPR will
7646 attempt to make a bitwise copy of EXPR to initialize
7647 VAR. */
7650 /* Create the INIT_EXPR that will initialize the temporary
7651 variable. */
7654 {
7659 else
7662 /* We must be careful to destroy the temporary only
7663 after its initialization has taken place. If the
7664 initialization throws an exception, then the
7665 destructor should not be run. We cannot simply
7666 transform INIT into something like:
7668 (INIT, ({ CLEANUP_STMT; }))
7670 because emit_local_var always treats the
7671 initializer as a full-expression. Thus, the
7672 destructor would run too early; it would run at the
7673 end of initializing the reference variable, rather
7674 than at the end of the block enclosing the
7675 reference variable.
7677 The solution is to pass back a cleanup expression
7678 which the caller is responsible for attaching to
7679 the statement tree. */
7680 }
7681 else
7682 {
7686 static_aggregates);
7687 }
7691 }
7693 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
7694 initializing a variable of that TYPE. If DECL is non-NULL, it is
7695 the VAR_DECL being initialized with the EXPR. (In that case, the
7696 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
7697 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
7698 return, if *CLEANUP is no longer NULL, it will be an expression
7699 that should be pushed as a cleanup after the returned expression
7700 is used to initialize DECL.
7702 Return the converted expression. */
7704 tree
7706 tsubst_flags_t complain)
7707 {
7714 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7718 LOOKUP_NORMAL);
7720 {
7722 {
7729 else
7733 }
7735 }
7737 /* If DECL is non-NULL, then this special rule applies:
7739 [class.temporary]
7741 The temporary to which the reference is bound or the temporary
7742 that is the complete object to which the reference is bound
7743 persists for the lifetime of the reference.
7745 The temporaries created during the evaluation of the expression
7746 initializing the reference, except the temporary to which the
7747 reference is bound, are destroyed at the end of the
7748 full-expression in which they are created.
7750 In that case, we store the converted expression into a new
7751 VAR_DECL in a new scope.
7753 However, we want to be careful not to create temporaries when
7754 they are not required. For example, given:
7756 struct B {};
7757 struct D : public B {};
7758 D f();
7759 const B& b = f();
7761 there is no need to copy the return value from "f"; we can just
7762 extend its lifetime. Similarly, given:
7764 struct S {};
7765 struct T { operator S(); };
7766 T t;
7767 const S& s = t;
7769 we can extend the lifetime of the return value of the conversion
7770 operator. */
7773 {
7774 tree var;
7775 tree base_conv_type;
7777 /* Skip over the REF_BIND. */
7779 /* If the next conversion is a BASE_CONV, skip that too -- but
7780 remember that the conversion was required. */
7782 {
7785 }
7786 else
7788 /* Perform the remainder of the conversion. */
7794 tf_warning_or_error);
7797 else
7798 {
7800 {
7801 tree init;
7803 /* Use its address to initialize the reference variable. */
7811 }
7812 else
7813 /* Take the address of EXPR. */
7815 /* If a BASE_CONV was required, perform it now. */
7817 expr = (perform_implicit_conversion
7819 tf_warning_or_error));
7821 }
7822 }
7823 else
7824 /* Perform the conversion. */
7827 /* Free all the conversions we allocated. */
7831 }
7833 /* Returns true iff TYPE is some variant of std::initializer_list. */
7835 bool
7837 {
7841 }
7843 /* Returns true iff DECL is a list constructor: i.e. a constructor which
7844 will accept an argument list of a single std::initializer_list<T>. */
7846 bool
7848 {
7850 tree arg;
7862 /* There are more non-defaulted parms. */
7866 }