| blob | 4b0955e3b765d439fbe87440a7ab3b9d71769536 |
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. */
468 {
472 }
474 }
476 /* Returns nonzero if PARMLIST consists of only default parms and/or
477 ellipsis. */
479 bool
481 {
487 }
489 /* Allocate N bytes of memory from the conversion obstack. The memory
490 is zeroed before being returned. */
494 {
497 {
500 }
504 }
506 /* Dynamically allocate a conversion. */
510 {
515 }
517 #ifdef ENABLE_CHECKING
519 /* Make sure that all memory on the conversion obstack has been
520 freed. */
522 void
524 {
528 }
532 /* Dynamically allocate an array of N conversions. */
536 {
538 }
542 {
546 /* Note that the caller is responsible for filling in t->cand for
547 user-defined conversions. */
553 {
569 }
575 }
577 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
578 specialization of std::initializer_list<T>, if such a conversion is
579 possible. */
583 {
589 tree val;
592 {
593 conversion *sub
600 }
608 {
616 }
619 }
621 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
622 aggregate class, if such a conversion is possible. */
626 {
632 {
636 {
641 }
644 }
652 }
654 /* Build a representation of the identity conversion from EXPR to
655 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
659 {
667 }
669 /* Converting from EXPR to TYPE was ambiguous in the sense that there
670 were multiple user-defined conversions to accomplish the job.
671 Build a conversion that indicates that ambiguity. */
675 {
683 }
685 tree
687 {
691 }
693 /* Returns the standard conversion path (see [conv]) from type FROM to type
694 TO, if any. For proper handling of null pointer constants, you must
695 also pass the expression EXPR to convert from. If C_CAST_P is true,
696 this conversion is coming from a C-style cast. */
701 {
708 {
711 }
722 {
730 }
737 {
741 }
743 {
745 {
746 tree bitfield_type;
749 {
752 }
753 }
755 }
757 /* Allow conversion between `__complex__' data types. */
759 {
760 /* The standard conversion sequence to convert FROM to TO is
761 the standard conversion sequence to perform componentwise
762 conversion. */
767 {
770 }
771 else
775 }
785 {
786 /* For backwards brain damage compatibility, allow interconversion of
787 pointers and integers with a pedwarn. */
790 }
792 {
793 /* For backwards brain damage compatibility, allow interconversion of
794 enums and integers with a pedwarn. */
797 }
800 {
801 tree to_pointee;
802 tree from_pointee;
807 ;
811 {
812 from = build_pointer_type
816 }
818 {
823 && (same_type_ignoring_top_level_qualifiers_p
826 {
830 }
833 }
836 /* [conv.ptr]
838 An rvalue of type "pointer to cv D," where D is a
839 class type, can be converted to an rvalue of type
840 "pointer to cv B," where B is a base class (clause
841 _class.derived_) of D. If B is an inaccessible
842 (clause _class.access_) or ambiguous
843 (_class.member.lookup_) base class of D, a program
844 that necessitates this conversion is ill-formed.
845 Therefore, we use DERIVED_FROM_P, and do not check
846 access or uniqueness. */
848 {
849 from =
855 }
858 {
861 }
862 else
863 {
866 }
871 /* In a C-style cast, we ignore CV-qualification because we
872 are allowed to perform a static_cast followed by a
873 const_cast. */
878 /* converting from string constant to char *. */
881 {
884 }
885 else
889 }
891 {
908 }
910 {
911 /* [conv.bool]
913 An rvalue of arithmetic, unscoped enumeration, pointer, or
914 pointer to member type can be converted to an rvalue of type
915 bool. */
920 {
928 }
931 }
932 /* We don't check for ENUMERAL_TYPE here because there are no standard
933 conversions to enum type. */
934 /* As an extension, allow conversion to complex type. */
936 {
942 /* Give this a better rank if it's a promotion. */
946 }
952 {
956 /* The derived-to-base conversion indicates the initialization
957 of a parameter with base type from an object of a derived
958 type. A temporary object is created to hold the result of
959 the conversion unless we're binding directly to a reference. */
961 }
962 else
969 }
971 /* Returns nonzero if T1 is reference-related to T2. */
973 bool
975 {
979 /* [dcl.init.ref]
981 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
982 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
983 of T2. */
987 }
989 /* Returns nonzero if T1 is reference-compatible with T2. */
991 static bool
993 {
994 /* [dcl.init.ref]
996 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
997 reference-related to T2 and cv1 is the same cv-qualification as,
998 or greater cv-qualification than, cv2. */
1001 }
1003 /* Determine whether or not the EXPR (of class type S) can be
1004 converted to T as in [over.match.ref]. */
1008 {
1009 tree conversions;
1010 tree first_arg;
1012 tree t;
1021 /* [over.match.ref]
1023 Assuming that "cv1 T" is the underlying type of the reference
1024 being initialized, and "cv S" is the type of the initializer
1025 expression, with S a class type, the candidate functions are
1026 selected as follows:
1028 --The conversion functions of S and its base classes are
1029 considered. Those that are not hidden within S and yield type
1030 "reference to cv2 T2", where "cv1 T" is reference-compatible
1031 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1033 The argument list has one argument, which is the initializer
1034 expression. */
1038 /* Conceptually, we should take the address of EXPR and put it in
1039 the argument list. Unfortunately, however, that can result in
1040 error messages, which we should not issue now because we are just
1041 trying to find a conversion operator. Therefore, we use NULL,
1042 cast to the appropriate type. */
1048 {
1052 {
1062 /* If this is a template function, try to get an exact
1063 match. */
1065 {
1068 NULL_TREE,
1069 first_arg,
1070 NULL,
1071 reference_type,
1074 LOOKUP_NORMAL,
1075 DEDUCE_CONV);
1078 {
1079 /* Now, see if the conversion function really returns
1080 an lvalue of the appropriate type. From the
1081 point of view of unification, simply returning an
1082 rvalue of the right type is good enough. */
1087 {
1090 }
1091 }
1092 }
1098 LOOKUP_NORMAL);
1101 {
1103 /* Build a standard conversion sequence indicating the
1104 binding from the reference type returned by the
1105 function to the desired REFERENCE_TYPE. */
1106 identity_conv
1109 NULL_TREE);
1110 cand->second_conv
1111 = (direct_reference_binding
1118 /* Don't allow binding of lvalues to rvalue references. */
1122 }
1123 }
1124 }
1127 /* If none of the conversion functions worked out, let our caller
1128 know. */
1136 /* Now that we know that this is the function we're going to use fix
1137 the dummy first argument. */
1142 /* Build a user-defined conversion sequence representing the
1143 conversion. */
1152 /* Merge it with the standard conversion sequence from the
1153 conversion function's return type to the desired type. */
1157 }
1159 /* A reference of the indicated TYPE is being bound directly to the
1160 expression represented by the implicit conversion sequence CONV.
1161 Return a conversion sequence for this binding. */
1165 {
1166 tree t;
1173 /* [over.ics.rank]
1175 When a parameter of reference type binds directly
1176 (_dcl.init.ref_) to an argument expression, the implicit
1177 conversion sequence is the identity conversion, unless the
1178 argument expression has a type that is a derived class of the
1179 parameter type, in which case the implicit conversion sequence is
1180 a derived-to-base Conversion.
1182 If the parameter binds directly to the result of applying a
1183 conversion function to the argument expression, the implicit
1184 conversion sequence is a user-defined conversion sequence
1185 (_over.ics.user_), with the second standard conversion sequence
1186 either an identity conversion or, if the conversion function
1187 returns an entity of a type that is a derived class of the
1188 parameter type, a derived-to-base conversion. */
1190 {
1191 /* Represent the derived-to-base conversion. */
1193 /* We will actually be binding to the base-class subobject in
1194 the derived class, so we mark this conversion appropriately.
1195 That way, convert_like knows not to generate a temporary. */
1197 }
1199 }
1201 /* Returns the conversion path from type FROM to reference type TO for
1202 purposes of reference binding. For lvalue binding, either pass a
1203 reference type to FROM or an lvalue expression to EXPR. If the
1204 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1205 the conversion returned. If C_CAST_P is true, this
1206 conversion is coming from a C-style cast. */
1210 {
1214 tree tfrom;
1220 {
1225 }
1228 {
1229 /* Anything with reference type is an lvalue. */
1232 }
1235 {
1238 flags);
1241 {
1246 }
1247 }
1256 /* Figure out whether or not the types are reference-related and
1257 reference compatible. We have do do this after stripping
1258 references from FROM. */
1260 /* If this is a C cast, first convert to an appropriately qualified
1261 type, so that we can later do a const_cast to the desired type. */
1267 /* Directly bind reference when target expression's type is compatible with
1268 the reference and expression is an lvalue. In DR391, the wording in
1269 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1270 const and rvalue references to rvalues of compatible class type.
1271 We should also do direct bindings for non-class "rvalues" derived from
1272 rvalue references. */
1274 && (is_lvalue
1279 {
1280 /* [dcl.init.ref]
1282 If the initializer expression
1284 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1285 is reference-compatible with "cv2 T2,"
1287 the reference is bound directly to the initializer expression
1288 lvalue.
1290 [...]
1291 If the initializer expression is an rvalue, with T2 a class type,
1292 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1293 is bound to the object represented by the rvalue or to a sub-object
1294 within that object. */
1300 /* The top-level caller requested that we pretend that the lvalue
1301 be treated as an rvalue. */
1303 else
1304 conv->rvaluedness_matches_p
1309 /* For the purposes of overload resolution, we ignore the fact
1310 this expression is a bitfield or packed field. (In particular,
1311 [over.ics.ref] says specifically that a function with a
1312 non-const reference parameter is viable even if the
1313 argument is a bitfield.)
1315 However, when we actually call the function we must create
1316 a temporary to which to bind the reference. If the
1317 reference is volatile, or isn't const, then we cannot make
1318 a temporary, so we just issue an error when the conversion
1319 actually occurs. */
1322 /* Don't allow binding of lvalues to rvalue references. */
1328 }
1329 /* [class.conv.fct] A conversion function is never used to convert a
1330 (possibly cv-qualified) object to the (possibly cv-qualified) same
1331 object type (or a reference to it), to a (possibly cv-qualified) base
1332 class of that type (or a reference to it).... */
1335 {
1336 /* [dcl.init.ref]
1338 If the initializer expression
1340 -- has a class type (i.e., T2 is a class type) can be
1341 implicitly converted to an lvalue of type "cv3 T3," where
1342 "cv1 T1" is reference-compatible with "cv3 T3". (this
1343 conversion is selected by enumerating the applicable
1344 conversion functions (_over.match.ref_) and choosing the
1345 best one through overload resolution. (_over.match_).
1347 the reference is bound to the lvalue result of the conversion
1348 in the second case. */
1352 }
1354 /* From this point on, we conceptually need temporaries, even if we
1355 elide them. Only the cases above are "direct bindings". */
1359 /* [over.ics.rank]
1361 When a parameter of reference type is not bound directly to an
1362 argument expression, the conversion sequence is the one required
1363 to convert the argument expression to the underlying type of the
1364 reference according to _over.best.ics_. Conceptually, this
1365 conversion sequence corresponds to copy-initializing a temporary
1366 of the underlying type with the argument expression. Any
1367 difference in top-level cv-qualification is subsumed by the
1368 initialization itself and does not constitute a conversion. */
1370 /* [dcl.init.ref]
1372 Otherwise, the reference shall be to a non-volatile const type.
1374 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1378 /* [dcl.init.ref]
1380 Otherwise, a temporary of type "cv1 T1" is created and
1381 initialized from the initializer expression using the rules for a
1382 non-reference copy initialization. If T1 is reference-related to
1383 T2, cv1 must be the same cv-qualification as, or greater
1384 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1388 /* We're generating a temporary now, but don't bind any more in the
1389 conversion (specifically, don't slice the temporary returned by a
1390 conversion operator). */
1393 /* Temporaries are copy-initialized, except for this hack to allow
1394 explicit conversion ops to the copy ctor. See also
1395 add_function_candidate. */
1401 flags);
1406 /* This reference binding, unlike those above, requires the
1407 creation of a temporary. */
1412 }
1414 /* Returns the implicit conversion sequence (see [over.ics]) from type
1415 FROM to type TO. The optional expression EXPR may affect the
1416 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1417 true, this conversion is coming from a C-style cast. */
1422 {
1431 else
1438 {
1442 /* Allow conversion from an initializer-list with one element to a
1443 scalar type. */
1445 {
1447 tree elt;
1453 else
1459 {
1462 /* Too many levels of braces, i.e. '{{1}}'. */
1465 }
1466 }
1467 }
1473 {
1486 /* We used to try to bind a reference to a temporary here, but that
1487 is now handled after the recursive call to this function at the end
1488 of reference_binding. */
1490 }
1493 }
1495 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1496 functions. ARGS will not be changed until a single candidate is
1497 selected. */
1505 {
1521 }
1523 /* Create an overload candidate for the function or method FN called
1524 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1525 FLAGS is passed on to implicit_conversion.
1527 This does not change ARGS.
1529 CTYPE, if non-NULL, is the type we want to pretend this function
1530 comes from for purposes of overload resolution. */
1537 {
1541 tree parmnode;
1546 /* At this point we should not see any functions which haven't been
1547 explicitly declared, except for friend functions which will have
1548 been found using argument dependent lookup. */
1551 /* The `this', `in_chrg' and VTT arguments to constructors are not
1552 considered in overload resolution. */
1554 {
1558 {
1561 }
1562 }
1563 else
1569 /* 13.3.2 - Viable functions [over.match.viable]
1570 First, to be a viable function, a candidate function shall have enough
1571 parameters to agree in number with the arguments in the list.
1573 We need to check this first; otherwise, checking the ICSes might cause
1574 us to produce an ill-formed template instantiation. */
1578 {
1582 }
1587 /* Make sure there are default args for the rest of the parms. */
1594 /* Second, for F to be a viable function, there shall exist for each
1595 argument an implicit conversion sequence that converts that argument
1596 to the corresponding parameter of F. */
1601 {
1611 else
1620 {
1624 /* The type of the implicit object parameter ('this') for
1625 overload resolution is not always the same as for the
1626 function itself; conversion functions are considered to
1627 be members of the class being converted, and functions
1628 introduced by a using-declaration are considered to be
1629 members of the class that uses them.
1631 Since build_over_call ignores the ICS for the `this'
1632 parameter, we can just change the parm type. */
1634 {
1635 parmtype
1639 }
1643 {
1644 /* Hack: Direct-initialize copy parm (i.e. suppress
1645 LOOKUP_ONLYCONVERTING) to make explicit conversion ops
1646 work. See also reference_binding. */
1650 }
1651 else
1656 }
1657 else
1658 {
1661 }
1668 {
1671 }
1678 }
1680 out:
1683 }
1685 /* Create an overload candidate for the conversion function FN which will
1686 be invoked for expression OBJ, producing a pointer-to-function which
1687 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1688 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1689 passed on to implicit_conversion.
1691 Actually, we don't really care about FN; we care about the type it
1692 converts to. There may be multiple conversion functions that will
1693 convert to that type, and we rely on build_user_type_conversion_1 to
1694 choose the best one; so when we create our candidate, we record the type
1695 instead of the function. */
1701 {
1717 /* Don't bother looking up the same type twice. */
1722 {
1730 else
1737 flags);
1743 else
1744 {
1747 }
1761 }
1771 }
1773 static void
1777 {
1790 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
1791 conversion ops are allowed. We handle that here by just checking for
1792 boolean_type_node because other operators don't ask for it. COND_EXPR
1793 also does contextual conversion to bool for the first operand, but we
1794 handle that in build_conditional_expr, and type1 here is operand 2. */
1799 {
1806 {
1808 /* We need something for printing the candidate. */
1810 }
1814 }
1816 /* For COND_EXPR we rearranged the arguments; undo that now. */
1818 {
1825 else
1827 }
1833 viable);
1834 }
1836 static bool
1838 {
1840 }
1842 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1844 static bool
1846 {
1847 /* [over.built]
1849 In this section, the term promoted integral type is used to refer
1850 to those integral types which are preserved by integral promotion
1851 (including e.g. int and long but excluding e.g. char).
1852 Similarly, the term promoted arithmetic type refers to promoted
1853 integral types plus floating types. */
1857 }
1859 /* Create any builtin operator overload candidates for the operator in
1860 question given the converted operand types TYPE1 and TYPE2. The other
1861 args are passed through from add_builtin_candidates to
1862 build_builtin_candidate.
1864 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1865 If CODE is requires candidates operands of the same type of the kind
1866 of which TYPE1 and TYPE2 are, we add both candidates
1867 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1869 static void
1873 {
1875 {
1883 }
1886 {
1888 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1889 and VQ is either volatile or empty, there exist candidate operator
1890 functions of the form
1891 VQ T& operator++(VQ T&);
1892 T operator++(VQ T&, int);
1893 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1894 type other than bool, and VQ is either volatile or empty, there exist
1895 candidate operator functions of the form
1896 VQ T& operator--(VQ T&);
1897 T operator--(VQ T&, int);
1898 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1899 complete object type, and VQ is either volatile or empty, there exist
1900 candidate operator functions of the form
1901 T*VQ& operator++(T*VQ&);
1902 T*VQ& operator--(T*VQ&);
1903 T* operator++(T*VQ&, int);
1904 T* operator--(T*VQ&, int); */
1913 {
1916 }
1919 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1920 exist candidate operator functions of the form
1922 T& operator*(T*);
1924 8 For every function type T, there exist candidate operator functions of
1925 the form
1926 T& operator*(T*); */
1935 /* 9 For every type T, there exist candidate operator functions of the form
1936 T* operator+(T*);
1938 10For every promoted arithmetic type T, there exist candidate operator
1939 functions of the form
1940 T operator+(T);
1941 T operator-(T); */
1951 /* 11For every promoted integral type T, there exist candidate operator
1952 functions of the form
1953 T operator~(T); */
1960 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1961 is the same type as C2 or is a derived class of C2, T is a complete
1962 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1963 there exist candidate operator functions of the form
1964 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1965 where CV12 is the union of CV1 and CV2. */
1970 {
1978 }
1981 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1982 didate operator functions of the form
1983 LR operator*(L, R);
1984 LR operator/(L, R);
1985 LR operator+(L, R);
1986 LR operator-(L, R);
1987 bool operator<(L, R);
1988 bool operator>(L, R);
1989 bool operator<=(L, R);
1990 bool operator>=(L, R);
1991 bool operator==(L, R);
1992 bool operator!=(L, R);
1993 where LR is the result of the usual arithmetic conversions between
1994 types L and R.
1996 14For every pair of types T and I, where T is a cv-qualified or cv-
1997 unqualified complete object type and I is a promoted integral type,
1998 there exist candidate operator functions of the form
1999 T* operator+(T*, I);
2000 T& operator[](T*, I);
2001 T* operator-(T*, I);
2002 T* operator+(I, T*);
2003 T& operator[](I, T*);
2005 15For every T, where T is a pointer to complete object type, there exist
2006 candidate operator functions of the form112)
2007 ptrdiff_t operator-(T, T);
2009 16For every pointer or enumeration type T, there exist candidate operator
2010 functions of the form
2011 bool operator<(T, T);
2012 bool operator>(T, T);
2013 bool operator<=(T, T);
2014 bool operator>=(T, T);
2015 bool operator==(T, T);
2016 bool operator!=(T, T);
2018 17For every pointer to member type T, there exist candidate operator
2019 functions of the form
2020 bool operator==(T, T);
2021 bool operator!=(T, T); */
2028 {
2031 }
2044 {
2047 }
2049 {
2052 }
2053 /* Fall through. */
2070 {
2073 }
2077 {
2080 }
2088 {
2091 }
2093 {
2096 }
2099 /* 18For every pair of promoted integral types L and R, there exist candi-
2100 date operator functions of the form
2101 LR operator%(L, R);
2102 LR operator&(L, R);
2103 LR operator^(L, R);
2104 LR operator|(L, R);
2105 L operator<<(L, R);
2106 L operator>>(L, R);
2107 where LR is the result of the usual arithmetic conversions between
2108 types L and R. */
2116 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2120 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2121 type, VQ is either volatile or empty, and R is a promoted arithmetic
2122 type, there exist candidate operator functions of the form
2123 VQ L& operator=(VQ L&, R);
2124 VQ L& operator*=(VQ L&, R);
2125 VQ L& operator/=(VQ L&, R);
2126 VQ L& operator+=(VQ L&, R);
2127 VQ L& operator-=(VQ L&, R);
2129 20For every pair T, VQ), where T is any type and VQ is either volatile
2130 or empty, there exist candidate operator functions of the form
2131 T*VQ& operator=(T*VQ&, T*);
2133 21For every pair T, VQ), where T is a pointer to member type and VQ is
2134 either volatile or empty, there exist candidate operator functions of
2135 the form
2136 VQ T& operator=(VQ T&, T);
2138 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2139 unqualified complete object type, VQ is either volatile or empty, and
2140 I is a promoted integral type, there exist candidate operator func-
2141 tions of the form
2142 T*VQ& operator+=(T*VQ&, I);
2143 T*VQ& operator-=(T*VQ&, I);
2145 23For every triple L, VQ, R), where L is an integral or enumeration
2146 type, VQ is either volatile or empty, and R is a promoted integral
2147 type, there exist candidate operator functions of the form
2149 VQ L& operator%=(VQ L&, R);
2150 VQ L& operator<<=(VQ L&, R);
2151 VQ L& operator>>=(VQ L&, R);
2152 VQ L& operator&=(VQ L&, R);
2153 VQ L& operator^=(VQ L&, R);
2154 VQ L& operator|=(VQ L&, R); */
2158 {
2162 {
2165 }
2178 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2191 {
2194 }
2199 }
2204 /* [over.built]
2206 For every pair of promoted arithmetic types L and R, there
2207 exist candidate operator functions of the form
2209 LR operator?(bool, L, R);
2211 where LR is the result of the usual arithmetic conversions
2212 between types L and R.
2214 For every type T, where T is a pointer or pointer-to-member
2215 type, there exist candidate operator functions of the form T
2216 operator?(bool, T, T); */
2220 /* That's OK. */
2223 /* Otherwise, the types should be pointers. */
2228 /* We don't check that the two types are the same; the logic
2229 below will actually create two candidates; one in which both
2230 parameter types are TYPE1, and one in which both parameter
2231 types are TYPE2. */
2236 }
2238 /* If we're dealing with two pointer types or two enumeral types,
2239 we need candidates for both of them. */
2248 {
2249 build_builtin_candidate
2251 build_builtin_candidate
2254 }
2256 build_builtin_candidate
2258 }
2260 tree
2262 {
2268 }
2270 /* There are three conditions of builtin candidates:
2272 1) bool-taking candidates. These are the same regardless of the input.
2273 2) pointer-pair taking candidates. These are generated for each type
2274 one of the input types converts to.
2275 3) arithmetic candidates. According to the standard, we should generate
2276 all of these, but I'm trying not to...
2278 Here we generate a superset of the possible candidates for this particular
2279 case. That is a subset of the full set the standard defines, plus some
2280 other cases which the standard disallows. add_builtin_candidate will
2281 filter out the invalid set. */
2283 static void
2287 {
2291 /* TYPES[i] is the set of possible builtin-operator parameter types
2292 we will consider for the Ith argument. These are represented as
2293 a TREE_LIST; the TREE_VALUE of each node is the potential
2294 parameter type. */
2298 {
2301 else
2303 }
2306 {
2307 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2308 and VQ is either volatile or empty, there exist candidate operator
2309 functions of the form
2310 VQ T& operator++(VQ T&); */
2320 /* 24There also exist candidate operator functions of the form
2321 bool operator!(bool);
2322 bool operator&&(bool, bool);
2323 bool operator||(bool, bool); */
2326 build_builtin_candidate
2333 build_builtin_candidate
2351 /* Fall through. */
2355 }
2360 {
2362 ;
2364 {
2365 tree convs;
2374 {
2381 }
2387 {
2400 {
2406 }
2410 }
2411 }
2412 else
2413 {
2419 {
2425 }
2427 }
2428 }
2430 /* Run through the possible parameter types of both arguments,
2431 creating candidates with those parameter types. */
2433 {
2436 add_builtin_candidate
2439 else
2440 add_builtin_candidate
2443 }
2444 }
2447 /* If TMPL can be successfully instantiated as indicated by
2448 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2450 TMPL is the template. EXPLICIT_TARGS are any explicit template
2451 arguments. ARGLIST is the arguments provided at the call-site.
2452 This does not change ARGLIST. The RETURN_TYPE is the desired type
2453 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2454 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2455 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2463 {
2473 tree arg;
2476 tree fn;
2478 /* We don't do deduction on the in-charge parameter, the VTT
2479 parameter or 'this'. */
2481 {
2484 else
2486 }
2491 {
2494 else
2496 }
2506 {
2509 }
2513 {
2516 }
2520 args_without_in_chrg,
2521 nargs_without_in_chrg,
2531 /* In [class.copy]:
2533 A member function template is never instantiated to perform the
2534 copy of a class object to an object of its class type.
2536 It's a little unclear what this means; the standard explicitly
2537 does allow a template to be used to copy a class. For example,
2538 in:
2540 struct A {
2541 A(A&);
2542 template <class T> A(const T&);
2543 };
2544 const A f ();
2545 void g () { A a (f ()); }
2547 the member template will be used to make the copy. The section
2548 quoted above appears in the paragraph that forbids constructors
2549 whose only parameter is (a possibly cv-qualified variant of) the
2550 class type, and a logical interpretation is that the intent was
2551 to forbid the instantiation of member templates which would then
2552 have that form. */
2554 {
2557 ctype))
2559 }
2562 /* Aha, this is a conversion function. */
2565 else
2570 /* This situation can occur if a member template of a template
2571 class is specialized. Then, instantiate_template might return
2572 an instantiation of the specialization, in which case the
2573 DECL_TI_TEMPLATE field will point at the original
2574 specialization. For example:
2576 template <class T> struct S { template <class U> void f(U);
2577 template <> void f(int) {}; };
2578 S<double> sd;
2579 sd.f(3);
2581 Here, TMPL will be template <class U> S<double>::f(U).
2582 And, instantiate template will give us the specialization
2583 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2584 for this will point at template <class T> template <> S<T>::f(int),
2585 so that we can find the definition. For the purposes of
2586 overload resolution, however, we want the original TMPL. */
2588 else
2592 }
2600 unification_kind_t strict)
2601 {
2602 return
2607 }
2615 tree conversion_path)
2616 {
2617 return
2621 }
2623 /* The CANDS are the set of candidates that were considered for
2624 overload resolution. Return the set of viable candidates. If none
2625 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2626 is true if a candidate should be considered viable only if it is
2627 strictly viable. */
2633 {
2644 {
2647 {
2653 }
2654 else
2656 }
2659 }
2661 static bool
2663 {
2668 }
2670 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2671 words, it is about to become the "this" pointer for a member
2672 function call. Take the address of the object. */
2674 static tree
2676 {
2677 /* In a template, we are only concerned about the type of the
2678 expression, so we can take a shortcut. */
2683 }
2685 /* Returns true iff functions are equivalent. Equivalent functions are
2686 not '==' only if one is a function-local extern function or if
2687 both are extern "C". */
2691 {
2696 }
2698 /* Print information about one overload candidate CANDIDATE. MSGSTR
2699 is the text to print before the candidate itself.
2701 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2702 to have been run through gettext by the caller. This wart makes
2703 life simpler in print_z_candidates and for the translators. */
2705 static void
2707 {
2709 {
2719 else
2722 }
2729 else
2731 }
2733 static void
2735 {
2744 /* Remove deleted candidates. */
2747 {
2751 else
2753 }
2754 /* ...if there are any non-deleted ones. */
2758 /* There may be duplicates in the set of candidates. We put off
2759 checking this condition as long as possible, since we have no way
2760 to eliminate duplicates from a set of functions in less than n^2
2761 time. Now we are about to emit an error message, so it is more
2762 permissible to go slowly. */
2764 {
2766 /* Skip builtin candidates and conversion functions. */
2771 {
2775 else
2777 }
2778 }
2783 {
2786 }
2788 }
2790 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2791 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2792 the result of the conversion function to convert it to the final
2793 desired type. Merge the two sequences into a single sequence,
2794 and return the merged sequence. */
2798 {
2803 /* Find the end of the second conversion sequence. */
2808 /* Replace the identity conversion with the user conversion
2809 sequence. */
2812 /* The entire sequence is a user-conversion sequence. */
2816 }
2818 /* Returns the best overload candidate to perform the requested
2819 conversion. This function is used for three the overloading situations
2820 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2821 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2822 per [dcl.init.ref], so we ignore temporary bindings. */
2826 {
2837 /* We represent conversion within a hierarchy using RVALUE_CONV and
2838 BASE_CONV, as specified by [over.best.ics]; these become plain
2839 constructor calls, as specified in [dcl.init]. */
2847 {
2852 {
2853 /* [class.conv.fct] A conversion function is never used to
2854 convert a (possibly cv-qualified) object to the (possibly
2855 cv-qualified) same object type (or a reference to it), to a
2856 (possibly cv-qualified) base class of that type (or a
2857 reference to it)... */
2858 }
2859 else
2862 }
2867 /* It's OK to bind a temporary for converting constructor arguments, but
2868 not in converting the return value of a conversion operator. */
2873 {
2879 {
2881 /* We still allow more conversions within an init-list. */
2883 /* But not for the copy ctor. */
2884 |LOOKUP_NO_COPY_CTOR_CONVERSION
2886 }
2887 else
2890 /* We should never try to call the abstract or base constructor
2891 from here. */
2894 }
2896 {
2907 flags,
2908 DEDUCE_CALL);
2909 else
2913 flags);
2916 {
2919 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2920 set, then this is copy-initialization. In that case, "The
2921 result of the call is then used to direct-initialize the
2922 object that is the destination of the copy-initialization."
2923 [dcl.init]
2925 We represent this in the conversion sequence with an
2926 rvalue conversion, which means a constructor call. */
2929 cand->second_conv
2931 }
2932 }
2938 {
2939 tree fns;
2942 /* If we are called to convert to a reference type, we are trying to
2943 find an lvalue binding, so don't even consider temporaries. If
2944 we don't find an lvalue binding, the caller will try again to
2945 look for a temporary binding. */
2950 {
2958 /* Lambdas have a static conversion op. */
2962 /* [over.match.funcs] For conversion functions, the function
2963 is considered to be a member of the class of the implicit
2964 object argument for the purpose of defining the type of
2965 the implicit object parameter.
2967 So we pass fromtype as CTYPE to add_*_candidate. */
2971 NULL_TREE,
2974 conversion_path,
2975 flags,
2976 DEDUCE_CONV);
2977 else
2981 conversion_path,
2982 flags);
2985 {
2986 conversion *ics
2992 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
2993 copy-initialization. In that case, "The result of the
2994 call is then used to direct-initialize the object that is
2995 the destination of the copy-initialization." [dcl.init]
2997 We represent this in the conversion sequence with an
2998 rvalue conversion, which means a constructor call. But
2999 don't add a second rvalue conversion if there's already
3000 one there. Which there really shouldn't be, but it's
3001 harmless since we'd add it here anyway. */
3012 }
3013 }
3014 }
3022 {
3024 {
3028 }
3035 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3036 ambiguous conversion is no worse than another user-defined
3037 conversion. */
3040 }
3042 /* Build the user conversion sequence. */
3043 conv = build_conv
3050 /* Remember that this was a list-initialization. */
3054 /* Combine it with the second conversion sequence. */
3062 }
3064 tree
3066 {
3071 {
3076 }
3078 }
3080 /* Do any initial processing on the arguments to a function call. */
3084 {
3086 tree arg;
3089 {
3093 {
3096 }
3099 }
3101 }
3103 /* Perform overload resolution on FN, which is called with the ARGS.
3105 Return the candidate function selected by overload resolution, or
3106 NULL if the event that overload resolution failed. In the case
3107 that overload resolution fails, *CANDIDATES will be the set of
3108 candidates considered, and ANY_VIABLE_P will be set to true or
3109 false to indicate whether or not any of the candidates were
3110 viable.
3112 The ARGS should already have gone through RESOLVE_ARGS before this
3113 function is called. */
3120 {
3128 /* Check FN. */
3135 {
3139 }
3141 /* Add the various candidate functions. */
3145 LOOKUP_NORMAL,
3146 candidates);
3154 }
3156 /* Return an expression for a call to FN (a namespace-scope function,
3157 or a static member function) with the ARGS. This may change
3158 ARGS. */
3160 tree
3162 tsubst_flags_t complain)
3163 {
3167 tree result;
3170 {
3174 }
3176 /* If this function was found without using argument dependent
3177 lookup, then we want to ignore any undeclared friend
3178 functions. */
3180 {
3185 {
3191 }
3192 }
3194 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3200 {
3202 {
3210 else
3215 }
3217 }
3218 else
3221 /* Free all the conversions we allocated. */
3225 }
3227 /* Build a call to a global operator new. FNNAME is the name of the
3228 operator (either "operator new" or "operator new[]") and ARGS are
3229 the arguments provided. This may change ARGS. *SIZE points to the
3230 total number of bytes required by the allocation, and is updated if
3231 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3232 be used. If this function determines that no cookie should be
3233 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3234 non-NULL, it will be set, upon return, to the allocation function
3235 called. */
3237 tree
3241 {
3242 tree fns;
3254 /* Based on:
3256 [expr.new]
3258 If this lookup fails to find the name, or if the allocated type
3259 is not a class type, the allocation function's name is looked
3260 up in the global scope.
3262 we disregard block-scope declarations of "operator new". */
3265 /* Figure out what function is being called. */
3268 /* If no suitable function could be found, issue an error message
3269 and give up. */
3271 {
3275 else
3281 }
3283 /* If a cookie is required, add some extra space. Whether
3284 or not a cookie is required cannot be determined until
3285 after we know which function was called. */
3287 {
3290 {
3291 /* In G++ 3.2, the check was implemented incorrectly; it
3292 looked at the placement expression, rather than the
3293 type of the function. */
3296 ptr_type_node))
3298 }
3299 else
3300 {
3301 tree arg_types;
3304 /* Skip the size_t parameter. */
3306 /* Check the remaining parameters (if any). */
3310 ptr_type_node))
3312 }
3313 /* If we need a cookie, adjust the number of bytes allocated. */
3315 {
3316 /* Update the total size. */
3318 /* Update the argument list to reflect the adjusted size. */
3320 }
3321 else
3323 }
3325 /* Tell our caller which function we decided to call. */
3329 /* Build the CALL_EXPR. */
3331 }
3333 /* Build a new call to operator(). This may change ARGS. */
3335 tree
3337 {
3351 {
3353 /* It's no good looking for an overloaded operator() on a
3354 pointer-to-member-function. */
3355 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3357 }
3360 {
3364 }
3365 else
3369 {
3373 }
3375 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3379 {
3384 {
3397 else
3398 add_function_candidate
3401 }
3402 }
3404 /* Rather than mess with handling static conversion ops here, just don't
3405 look at conversions in lambdas. */
3408 else
3412 {
3424 {
3431 add_template_conv_candidate
3435 else
3439 }
3440 }
3444 {
3446 {
3450 }
3452 }
3453 else
3454 {
3457 {
3459 {
3463 }
3465 }
3466 /* Since cand->fn will be a type, not a function, for a conversion
3467 function, we must be careful not to unconditionally look at
3468 DECL_NAME here. */
3472 else
3473 {
3475 complain);
3478 }
3479 }
3481 /* Free all the conversions we allocated. */
3485 }
3487 static void
3490 {
3495 else
3499 {
3504 else
3514 else
3523 else
3533 else
3543 else
3546 else
3550 else
3554 }
3555 }
3557 /* Return the implicit conversion sequence that could be used to
3558 convert E1 to E2 in [expr.cond]. */
3562 {
3568 /* [expr.cond]
3570 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3571 implicitly converted (clause _conv_) to the type "reference to
3572 T2", subject to the constraint that in the conversion the
3573 reference must bind directly (_dcl.init.ref_) to E1. */
3575 {
3577 t1,
3578 e1,
3583 }
3585 /* [expr.cond]
3587 If E1 and E2 have class type, and the underlying class types are
3588 the same or one is a base class of the other: E1 can be converted
3589 to match E2 if the class of T2 is the same type as, or a base
3590 class of, the class of T1, and the cv-qualification of T2 is the
3591 same cv-qualification as, or a greater cv-qualification than, the
3592 cv-qualification of T1. If the conversion is applied, E1 is
3593 changed to an rvalue of type T2 that still refers to the original
3594 source class object (or the appropriate subobject thereof). */
3597 {
3599 {
3604 else
3607 }
3608 else
3610 }
3611 else
3612 /* [expr.cond]
3614 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3615 converted to the type that expression E2 would have if E2 were
3616 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3618 LOOKUP_IMPLICIT);
3619 }
3621 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3622 arguments to the conditional expression. */
3624 tree
3626 tsubst_flags_t complain)
3627 {
3628 tree arg2_type;
3629 tree arg3_type;
3631 tree result_save;
3638 /* As a G++ extension, the second argument to the conditional can be
3639 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3640 c'.) If the second operand is omitted, make sure it is
3641 calculated only once. */
3643 {
3648 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3651 else
3653 }
3655 /* [expr.cond]
3657 The first expression is implicitly converted to bool (clause
3658 _conv_). */
3660 LOOKUP_NORMAL);
3662 /* If something has already gone wrong, just pass that fact up the
3663 tree. */
3669 /* [expr.cond]
3671 If either the second or the third operand has type (possibly
3672 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3673 array-to-pointer (_conv.array_), and function-to-pointer
3674 (_conv.func_) standard conversions are performed on the second
3675 and third operands. */
3679 {
3680 /* Do the conversions. We don't these for `void' type arguments
3681 since it can't have any effect and since decay_conversion
3682 does not handle that case gracefully. */
3690 /* [expr.cond]
3692 One of the following shall hold:
3694 --The second or the third operand (but not both) is a
3695 throw-expression (_except.throw_); the result is of the
3696 type of the other and is an rvalue.
3698 --Both the second and the third operands have type void; the
3699 result is of type void and is an rvalue.
3701 We must avoid calling force_rvalue for expressions of type
3702 "void" because it will complain that their value is being
3703 used. */
3706 {
3711 }
3714 {
3719 }
3722 else
3723 {
3725 {
3728 "is of type %<void%>, "
3729 "but the third operand is neither a throw-expression "
3731 else
3733 "is of type %<void%>, "
3734 "but the second operand is neither a throw-expression "
3736 }
3738 }
3742 }
3743 /* [expr.cond]
3745 Otherwise, if the second and third operand have different types,
3746 and either has (possibly cv-qualified) class type, an attempt is
3747 made to convert each of those operands to the type of the other. */
3750 {
3754 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3760 /* [expr.cond]
3762 If both can be converted, or one can be converted but the
3763 conversion is ambiguous, the program is ill-formed. If
3764 neither can be converted, the operands are left unchanged and
3765 further checking is performed as described below. If exactly
3766 one conversion is possible, that conversion is applied to the
3767 chosen operand and the converted operand is used in place of
3768 the original operand for the remainder of this section. */
3773 {
3777 }
3779 {
3783 /* Even if CONV2 is a valid conversion, the result of the
3784 conversion may be invalid. For example, if ARG3 has type
3785 "volatile X", and X does not have a copy constructor
3786 accepting a "volatile X&", then even if ARG2 can be
3787 converted to X, the conversion will fail. */
3790 }
3792 {
3798 }
3800 /* Free all the conversions we allocated. */
3806 /* If, after the conversion, both operands have class type,
3807 treat the cv-qualification of both operands as if it were the
3808 union of the cv-qualification of the operands.
3810 The standard is not clear about what to do in this
3811 circumstance. For example, if the first operand has type
3812 "const X" and the second operand has a user-defined
3813 conversion to "volatile X", what is the type of the second
3814 operand after this step? Making it be "const X" (matching
3815 the first operand) seems wrong, as that discards the
3816 qualification without actually performing a copy. Leaving it
3817 as "volatile X" seems wrong as that will result in the
3818 conditional expression failing altogether, even though,
3819 according to this step, the one operand could be converted to
3820 the type of the other. */
3828 }
3830 /* [expr.cond]
3832 If the second and third operands are lvalues and have the same
3833 type, the result is of that type and is an lvalue. */
3837 {
3840 }
3842 /* [expr.cond]
3844 Otherwise, the result is an rvalue. If the second and third
3845 operand do not have the same type, and either has (possibly
3846 cv-qualified) class type, overload resolution is used to
3847 determine the conversions (if any) to be applied to the operands
3848 (_over.match.oper_, _over.built_). */
3852 {
3857 /* Rearrange the arguments so that add_builtin_candidate only has
3858 to know about two args. In build_builtin_candidate, the
3859 arguments are unscrambled. */
3864 COND_EXPR,
3865 NOP_EXPR,
3867 args,
3868 LOOKUP_NORMAL);
3870 /* [expr.cond]
3872 If the overload resolution fails, the program is
3873 ill-formed. */
3876 {
3878 {
3881 }
3883 }
3886 {
3888 {
3891 }
3893 }
3895 /* [expr.cond]
3897 Otherwise, the conversions thus determined are applied, and
3898 the converted operands are used in place of the original
3899 operands for the remainder of this section. */
3908 }
3910 /* [expr.cond]
3912 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3913 and function-to-pointer (_conv.func_) standard conversions are
3914 performed on the second and third operands.
3916 We need to force the lvalue-to-rvalue conversion here for class types,
3917 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3918 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3919 regions. */
3932 /* [expr.cond]
3934 After those conversions, one of the following shall hold:
3936 --The second and third operands have the same type; the result is of
3937 that type. */
3940 /* [expr.cond]
3942 --The second and third operands have arithmetic or enumeration
3943 type; the usual arithmetic conversions are performed to bring
3944 them to a common type, and the result is of that type. */
3949 {
3950 /* In this case, there is always a common type. */
3952 arg3_type);
3956 {
3961 }
3967 {
3971 }
3975 }
3976 /* [expr.cond]
3978 --The second and third operands have pointer type, or one has
3979 pointer type and the other is a null pointer constant; pointer
3980 conversions (_conv.ptr_) and qualification conversions
3981 (_conv.qual_) are performed to bring them to their composite
3982 pointer type (_expr.rel_). The result is of the composite
3983 pointer type.
3985 --The second and third operands have pointer to member type, or
3986 one has pointer to member type and the other is a null pointer
3987 constant; pointer to member conversions (_conv.mem_) and
3988 qualification conversions (_conv.qual_) are performed to bring
3989 them to a common type, whose cv-qualification shall match the
3990 cv-qualification of either the second or the third operand.
3991 The result is of the common type. */
3999 {
4002 complain);
4007 }
4010 {
4015 }
4017 valid_operands:
4022 /* Avoid folding to a CALL_EXPR within decltype (c++/42013). */
4025 /* We can't use result_type below, as fold might have returned a
4026 throw_expr. */
4029 {
4030 /* Expand both sides into the same slot, hopefully the target of
4031 the ?: expression. We used to check for TARGET_EXPRs here,
4032 but now we sometimes wrap them in NOP_EXPRs so the test would
4033 fail. */
4036 /* If this expression is an rvalue, but might be mistaken for an
4037 lvalue, we must add a NON_LVALUE_EXPR. */
4039 }
4042 }
4044 /* OPERAND is an operand to an expression. Perform necessary steps
4045 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
4046 returned. */
4048 static tree
4050 {
4052 {
4055 /* Make sure the template type is instantiated now. */
4057 }
4060 }
4062 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4063 OVERLOAD) to the CANDIDATES, returning an updated list of
4064 CANDIDATES. The ARGS are the arguments provided to the call,
4065 without any implicit object parameter. This may change ARGS. The
4066 EXPLICIT_TARGS are explicit template arguments provided.
4067 TEMPLATE_ONLY is true if only template functions should be
4068 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4069 add_function_candidate. */
4071 static void
4077 {
4078 tree ctype;
4080 tree first_arg;
4083 /* Delay creating the implicit this parameter until it is needed. */
4088 {
4089 tree fn;
4090 tree fn_first_arg;
4094 /* Figure out which set of arguments to use. */
4096 {
4097 /* If this function is a non-static member, prepend the implicit
4098 object parameter. */
4100 {
4102 tree arg;
4108 }
4113 }
4114 else
4115 {
4116 /* Otherwise, just use the list of arguments provided. */
4119 }
4123 fn,
4124 ctype,
4125 explicit_targs,
4126 fn_first_arg,
4127 fn_args,
4128 NULL_TREE,
4129 access_path,
4130 conversion_path,
4131 flags,
4132 DEDUCE_CALL);
4135 fn,
4136 ctype,
4137 fn_first_arg,
4138 fn_args,
4139 access_path,
4140 conversion_path,
4141 flags);
4143 }
4144 }
4146 /* Even unsigned enum types promote to signed int. We don't want to
4147 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4148 original argument and ARG is the argument after any conversions
4149 have been applied. We set TREE_NO_WARNING if we have added a cast
4150 from an unsigned enum type to a signed integer type. */
4152 static void
4154 {
4163 }
4165 tree
4168 {
4174 tree fnname;
4192 {
4196 }
4197 else
4203 {
4208 /* Use build_op_new_call and build_op_delete_call instead. */
4212 /* Use build_op_call instead. */
4219 /* These are saved for the sake of warn_logical_operator. */
4225 }
4231 /* Use build_conditional_expr instead. */
4247 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4250 /* Add namespace-scope operators to the list of functions to
4251 consider. */
4255 /* Add class-member operators to the candidate set. */
4257 {
4258 tree fns;
4262 {
4265 }
4272 }
4281 {
4284 /* For these, the built-in candidates set is empty
4285 [over.match.oper]/3. We don't want non-strict matches
4286 because exact matches are always possible with built-in
4287 operators. The built-in candidate set for COMPONENT_REF
4288 would be empty too, but since there are no such built-in
4289 operators, we accept non-strict matches for them. */
4296 }
4300 {
4302 {
4305 /* Don't try anything fancy if we're not allowed to produce
4306 errors. */
4310 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4311 distinguish between prefix and postfix ++ and
4312 operator++() was used for both, so we allow this with
4313 -fpermissive. */
4315 {
4322 }
4329 else
4335 /* The caller will deal with these. */
4345 {
4346 /* If one of the arguments of the operator represents
4347 an invalid use of member function pointer, try to report
4348 a meaningful error ... */
4353 else
4354 {
4355 /* ... Otherwise, report the more generic
4356 "no matching operator found" error */
4359 }
4360 }
4363 }
4364 }
4365 else
4366 {
4369 {
4371 {
4374 }
4376 }
4378 {
4384 else
4386 }
4387 else
4388 {
4389 /* Give any warnings we noticed during overload resolution. */
4391 {
4395 }
4397 /* Check for comparison of different enum types. */
4399 {
4411 {
4415 }
4419 }
4421 /* We need to strip any leading REF_BIND so that bitfields
4422 don't cause errors. This should not remove any important
4423 conversions, because builtins don't apply to class
4424 objects directly. */
4431 {
4432 /* We need to call warn_logical_operator before
4433 converting arg2 to a boolean_type. */
4443 }
4445 {
4450 }
4452 }
4453 }
4455 user_defined_result_ready:
4457 /* Free all the conversions we allocated. */
4463 builtin:
4469 {
4482 /* Fall through. */
4520 complain),
4521 arg2);
4523 /* The caller will deal with these. */
4531 }
4533 }
4535 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
4536 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
4538 static bool
4540 {
4541 /* A template instance is never a usual deallocation function,
4542 regardless of its signature. */
4547 /* If a class T has a member deallocation function named operator delete
4548 with exactly one parameter, then that function is a usual
4549 (non-placement) deallocation function. If class T does not declare
4550 such an operator delete but does declare a member deallocation
4551 function named operator delete with exactly two parameters, the second
4552 of which has type std::size_t (18.2), then this function is a usual
4553 deallocation function. */
4560 }
4562 /* Build a call to operator delete. This has to be handled very specially,
4563 because the restrictions on what signatures match are different from all
4564 other call instances. For a normal delete, only a delete taking (void *)
4565 or (void *, size_t) is accepted. For a placement delete, only an exact
4566 match with the placement new is accepted.
4568 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4569 ADDR is the pointer to be deleted.
4570 SIZE is the size of the memory block to be deleted.
4571 GLOBAL_P is true if the delete-expression should not consider
4572 class-specific delete operators.
4573 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4575 If this call to "operator delete" is being generated as part to
4576 deallocate memory allocated via a new-expression (as per [expr.new]
4577 which requires that if the initialization throws an exception then
4578 we call a deallocation function), then ALLOC_FN is the allocation
4579 function. */
4581 tree
4584 tree alloc_fn)
4585 {
4599 /* In [class.free]
4601 If the result of the lookup is ambiguous or inaccessible, or if
4602 the lookup selects a placement deallocation function, the
4603 program is ill-formed.
4605 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4606 {
4610 }
4611 else
4617 /* Strip const and volatile from addr. */
4621 {
4622 /* "A declaration of a placement deallocation function matches the
4623 declaration of a placement allocation function if it has the same
4624 number of parameters and, after parameter transformations (8.3.5),
4625 all parameter types except the first are identical."
4627 So we build up the function type we want and ask instantiate_type
4628 to get it for us. */
4640 /* "If the lookup finds the two-parameter form of a usual deallocation
4641 function (3.7.4.2) and that function, considered as a placement
4642 deallocation function, would have been selected as a match for the
4643 allocation function, the program is ill-formed." */
4645 {
4646 /* But if the class has an operator delete (void *), then that is
4647 the usual deallocation function, so we shouldn't complain
4648 about using the operator delete (void *, size_t). */
4651 {
4656 }
4659 ok:;
4660 }
4661 }
4662 else
4663 /* "Any non-placement deallocation function matches a non-placement
4664 allocation function. If the lookup finds a single matching
4665 deallocation function, that function will be called; otherwise, no
4666 deallocation function will be called." */
4669 {
4672 {
4674 /* "If a class T has a member deallocation function named
4675 operator delete with exactly one parameter, then that
4676 function is a usual (non-placement) deallocation
4677 function. If class T does not declare such an operator
4678 delete but does declare a member deallocation function named
4679 operator delete with exactly two parameters, the second of
4680 which has type std::size_t (18.2), then this function is a
4681 usual deallocation function."
4683 So (void*) beats (void*, size_t). */
4686 }
4687 }
4689 /* If we have a matching function, call it. */
4691 {
4694 /* If the FN is a member function, make sure that it is
4695 accessible. */
4699 /* Core issue 901: It's ok to new a type with deleted delete. */
4704 {
4705 /* The placement args might not be suitable for overload
4706 resolution at this point, so build the call directly. */
4715 }
4716 else
4717 {
4718 tree ret;
4726 }
4727 }
4729 /* [expr.new]
4731 If no unambiguous matching deallocation function can be found,
4732 propagating the exception does not cause the object's memory to
4733 be freed. */
4735 {
4738 alloc_fn);
4740 }
4745 }
4747 /* If the current scope isn't allowed to access DECL along
4748 BASETYPE_PATH, give an error. The most derived class in
4749 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4750 the declaration to use in the error diagnostic. */
4752 bool
4754 {
4758 {
4763 else
4767 }
4770 }
4772 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4773 bitwise or of LOOKUP_* values. If any errors are warnings are
4774 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4775 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4776 to NULL. */
4778 static tree
4781 {
4794 else
4797 }
4799 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4800 EXPR is implicitly converted to type TOTYPE.
4801 FN and ARGNUM are used for diagnostics. */
4803 static void
4805 {
4808 /* Issue warnings about peculiar, but valid, uses of NULL. */
4810 {
4814 else
4816 }
4818 /* Issue warnings if "false" is converted to a NULL pointer */
4823 }
4825 /* Perform the conversions in CONVS on the expression EXPR. FN and
4826 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4827 indicates the `this' argument of a method. INNER is nonzero when
4828 being called to continue a conversion chain. It is negative when a
4829 reference binding will be applied, positive otherwise. If
4830 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4831 conversions will be emitted if appropriate. If C_CAST_P is true,
4832 this conversion is coming from a C-style cast; in that case,
4833 conversions to inaccessible bases are permitted. */
4835 static tree
4839 {
4841 diagnostic_t diag_kind;
4851 {
4854 /* Give a helpful error if this is bad because of excess braces. */
4862 {
4864 {
4868 complain);
4870 }
4875 complain);
4878 }
4880 {
4884 }
4885 else
4889 }
4895 {
4897 {
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 }
4935 {
4941 else
4943 }
4947 /* Convert a constant to its underlying value, unless we are
4948 about to bind it to a reference, in which case we need to
4949 leave it as an lvalue. */
4951 {
4954 /* If __null has been converted to an integer type, we do not
4955 want to warn about uses of EXPR as an integer, rather than
4956 as a pointer. */
4958 }
4961 /* Call build_user_type_conversion again for the error. */
4962 return build_user_type_conversion
4966 {
4967 /* Conversion to std::initializer_list<T>. */
4975 /* Convert all the elements. */
4977 {
4984 }
4985 /* Build up the array. */
4986 elttype = cp_build_qualified_type
4994 /* Call the private constructor. */
4996 new_ctor = build_special_member_call
5001 }
5008 };
5013 c_cast_p,
5014 complain);
5019 {
5024 /* Else fall through. */
5027 {
5028 /* We are going to bind a reference directly to a base-class
5029 subobject of EXPR. */
5030 /* Build an expression for `*((base*) &expr)'. */
5036 }
5038 /* Copy-initialization where the cv-unqualified version of the source
5039 type is the same class as, or a derived class of, the class of the
5040 destination [is treated as direct-initialization]. [dcl.init] */
5043 /* This conversion is being done in the context of a user-defined
5044 conversion (i.e. the second step of copy-initialization), so
5045 don't allow any more. */
5049 {
5055 }
5059 {
5064 {
5066 {
5071 }
5073 }
5075 /* If necessary, create a temporary.
5077 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5078 that need temporaries, even when their types are reference
5079 compatible with the type of reference being bound, so the
5080 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
5081 doesn't fail. */
5085 {
5091 {
5093 {
5094 /* If the reference is volatile or non-const, we
5095 cannot create a temporary. */
5102 else
5104 }
5106 }
5107 /* If the source is a packed field, and we must use a copy
5108 constructor, then building the target expr will require
5109 binding the field to the reference parameter to the
5110 copy constructor, and we'll end up with an infinite
5111 loop. If we can use a bitwise copy, then we'll be
5112 OK. */
5116 {
5121 }
5123 {
5126 }
5128 }
5130 /* Take the address of the thing to which we will bind the
5131 reference. */
5136 /* Convert it to a pointer to the type referred to by the
5137 reference. This will adjust the pointer if a derived to
5138 base conversion is being performed. */
5140 expr);
5141 /* Convert the pointer to the desired reference type. */
5143 }
5149 /* Warn about deprecated conversion if appropriate. */
5161 c_cast_p);
5165 }
5172 else
5176 }
5178 /* ARG is being passed to a varargs function. Perform any conversions
5179 required. Return the converted value. */
5181 tree
5183 {
5184 /* [expr.call]
5186 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5187 standard conversions are performed. */
5189 /* [expr.call]
5191 If the argument has integral or enumeration type that is subject
5192 to the integral promotions (_conv.prom_), or a floating point
5193 type that is subject to the floating point promotion
5194 (_conv.fpprom_), the value of the argument is converted to the
5195 promoted type before the call. */
5209 {
5210 /* [expr.call] 5.2.2/7:
5211 Passing a potentially-evaluated argument of class type (Clause 9)
5212 with a non-trivial copy constructor or a non-trivial destructor
5213 with no corresponding parameter is conditionally-supported, with
5214 implementation-defined semantics.
5216 We used to just warn here and do a bitwise copy, but now
5217 cp_expr_size will abort if we try to do that.
5219 If the call appears in the context of a sizeof expression,
5220 it is not potentially-evaluated. */
5224 }
5227 }
5229 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5231 tree
5233 {
5245 {
5246 /* Remove reference types so we don't ICE later on. */
5248 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5254 }
5257 }
5259 /* TYPE has been given to va_arg. Apply the default conversions which
5260 would have happened when passed via ellipsis. Return the promoted
5261 type, or the passed type if there is no change. */
5263 tree
5265 {
5266 tree promote;
5268 /* Perform the array-to-pointer and function-to-pointer
5269 conversions. */
5277 }
5279 /* ARG is a default argument expression being passed to a parameter of
5280 the indicated TYPE, which is a parameter to FN. Do any required
5281 conversions. Return the converted value. */
5285 tree
5287 {
5289 tree t;
5291 /* If the ARG is an unparsed default argument expression, the
5292 conversion cannot be performed. */
5294 {
5299 }
5301 /* Detect recursion. */
5304 {
5307 }
5313 /* Due to:
5315 [dcl.fct.default]
5317 The names in the expression are bound, and the semantic
5318 constraints are checked, at the point where the default
5319 expressions appears.
5321 we must not perform access checks here. */
5325 {
5329 tf_warning_or_error);
5330 }
5331 else
5332 {
5333 /* We must make a copy of ARG, in case subsequent processing
5334 alters any part of it. For example, during gimplification a
5335 cast of the form (T) &X::f (where "f" is a member function)
5336 will lead to replacing the PTRMEM_CST for &X::f with a
5337 VAR_DECL. We can avoid the copy for constants, since they
5338 are never modified in place. */
5343 tf_warning_or_error);
5345 }
5351 }
5353 /* Returns the type which will really be used for passing an argument of
5354 type TYPE. */
5356 tree
5358 {
5359 /* Pass classes with copy ctors by invisible reference. */
5361 {
5363 /* There are no other pointers to this temporary. */
5365 }
5374 }
5376 /* Actually perform the appropriate conversion. */
5378 tree
5380 {
5381 tree bitfield_type;
5383 /* If VAL is a bitfield, then -- since it has already been converted
5384 to TYPE -- it cannot have a precision greater than TYPE.
5386 If it has a smaller precision, we must widen it here. For
5387 example, passing "int f:3;" to a function expecting an "int" will
5388 not result in any conversion before this point.
5390 If the precision is the same we must not risk widening. For
5391 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5392 often have type "int", even though the C++ type for the field is
5393 "long long". If the value is being passed to a function
5394 expecting an "int", then no conversions will be required. But,
5395 if we call convert_bitfield_to_declared_type, the bitfield will
5396 be converted to "long long". */
5403 ;
5404 /* Pass classes with copy ctors by invisible reference. */
5414 {
5423 }
5425 }
5427 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5428 which no conversions at all should be done. This is true for some
5429 builtins which don't act like normal functions. */
5431 static bool
5433 {
5436 {
5446 }
5449 }
5451 /* Subroutine of the various build_*_call functions. Overload resolution
5452 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5453 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5454 bitmask of various LOOKUP_* flags which apply to the call itself. */
5456 static tree
5458 {
5466 tree val;
5475 /* In a template, there is no need to perform all of the work that
5476 is normally done. We are only interested in the type of the call
5477 expression, i.e., the return type of the function. Any semantic
5478 errors will be deferred until the template is instantiated. */
5480 {
5481 tree expr;
5482 tree return_type;
5490 else
5491 {
5494 tree arg;
5502 }
5505 argarray);
5511 }
5513 /* Give any warnings we noticed during overload resolution. */
5515 {
5519 }
5521 /* Make =delete work with SFINAE. */
5526 {
5527 /* If FN is a template function, two cases must be considered.
5528 For example:
5530 struct A {
5531 protected:
5532 template <class T> void f();
5533 };
5534 template <class T> struct B {
5535 protected:
5536 void g();
5537 };
5538 struct C : A, B<int> {
5539 using A::f; // #1
5540 using B<int>::g; // #2
5541 };
5543 In case #1 where `A::f' is a member template, DECL_ACCESS is
5544 recorded in the primary template but not in its specialization.
5545 We check access of FN using its primary template.
5547 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5548 because it is a member of class template B, DECL_ACCESS is
5549 recorded in the specialization `B<int>::g'. We cannot use its
5550 primary template because `B<T>::g' and `B<int>::g' may have
5551 different access. */
5556 else
5558 }
5560 /* Find maximum size of vector to hold converted arguments. */
5567 /* The implicit parameters to a constructor are not considered by overload
5568 resolution, and must be of the proper type. */
5570 {
5572 {
5575 }
5576 else
5577 {
5580 }
5582 /* We should never try to call the abstract constructor. */
5586 {
5590 }
5591 }
5592 /* Bypass access control for 'this' parameter. */
5594 {
5597 ? first_arg
5600 tree converted_arg;
5601 tree base_binfo;
5604 {
5608 else
5610 }
5612 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5613 X is called for an object that is not of type X, or of a type
5614 derived from X, the behavior is undefined.
5616 So we can assume that anything passed as 'this' is non-null, and
5617 optimize accordingly. */
5619 /* Convert to the base in which the function was declared. */
5622 arg,
5625 /* Check that the base class is accessible. */
5631 /* If fn was found by a using declaration, the conversion path
5632 will be to the derived class, not the base declaring fn. We
5633 must convert from derived to base. */
5643 else
5647 }
5652 {
5657 /* Don't make a copy here if build_call is going to. */
5663 /* Warn about initializer_list deduction that isn't currently in the
5664 working draft. */
5666 && flag_deduce_init_list
5669 {
5679 {
5686 }
5687 }
5689 val = convert_like_with_context
5691 complain);
5696 else
5698 }
5700 /* Default arguments */
5705 /* Ellipsis */
5707 {
5711 else
5714 }
5722 /* Avoid actually calling copy constructors and copy assignment operators,
5723 if possible. */
5730 {
5731 tree targ;
5733 tree fa;
5735 /* Pull out the real argument, disregarding const-correctness. */
5741 {
5746 }
5747 else
5752 else
5757 {
5758 /* Copy-list-initialization doesn't require the copy constructor
5759 to be defined. */
5760 }
5761 /* [class.copy]: the copy constructor is implicitly defined even if
5762 the implementation elided its use. */
5764 {
5767 }
5769 /* If we're creating a temp and we already have one, don't create a
5770 new one. If we're not creating a temp but we get one, use
5771 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5772 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5773 temp or an INIT_EXPR otherwise. */
5778 {
5783 }
5787 {
5789 complain));
5793 }
5794 }
5798 {
5799 tree to = stabilize_reference
5806 {
5809 }
5810 else
5811 {
5812 /* We must only copy the non-tail padding parts.
5813 Use __builtin_memcpy for the bitwise copy.
5814 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5815 instead of an explicit call to memcpy. */
5825 {
5826 /* If we can't be sure about pointer alignment, a call
5827 to __builtin_memcpy is expanded as a call to memcpy, which
5828 is invalid with identical args. Otherwise it is
5829 expanded as a block move, which should be safe. */
5833 }
5842 }
5845 }
5851 {
5852 tree t;
5858 /* Warn about deprecated virtual functions now, since we're about
5859 to throw away the decl. */
5869 else
5872 }
5873 else
5877 }
5879 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5880 This function performs no overload resolution, conversion, or other
5881 high-level operations. */
5883 tree
5885 {
5886 tree fndecl;
5890 /* If this call might throw an exception, note that fact. */
5897 /* Check that arguments to builtin functions match the expectations. */
5904 /* Some built-in function calls will be evaluated at compile-time in
5905 fold (). */
5918 }
5922 /* Make an expression which yields the address of the Java interface
5923 method FN. This is achieved by generating a call to libjava's
5924 _Jv_LookupInterfaceMethodIdx(). */
5926 static tree
5928 {
5934 {
5939 endlink)));
5940 java_iface_lookup_fn
5944 }
5946 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5947 This is the first entry in the vtable. */
5949 tf_warning_or_error),
5950 integer_zero_node);
5952 /* Get the java.lang.Class pointer for the interface being called. */
5957 {
5959 iface);
5961 }
5965 /* Determine the itable index of FN. */
5968 {
5973 i++;
5974 }
5979 java_iface_lookup_fn);
5982 }
5984 /* Returns the value to use for the in-charge parameter when making a
5985 call to a function with the indicated NAME.
5987 FIXME:Can't we find a neater way to do this mapping? */
5989 tree
5991 {
6002 /* This function should only be called with one of the names listed
6003 above. */
6006 }
6008 /* Build a call to a constructor, destructor, or an assignment
6009 operator for INSTANCE, an expression with class type. NAME
6010 indicates the special member function to call; *ARGS are the
6011 arguments. ARGS may be NULL. This may change ARGS. BINFO
6012 indicates the base of INSTANCE that is to be passed as the `this'
6013 parameter to the member function called.
6015 FLAGS are the LOOKUP_* flags to use when processing the call.
6017 If NAME indicates a complete object constructor, INSTANCE may be
6018 NULL_TREE. In this case, the caller will call build_cplus_new to
6019 store the newly constructed object into a VAR_DECL. */
6021 tree
6024 {
6025 tree fns;
6026 /* The type of the subobject to be constructed or destroyed. */
6027 tree class_type;
6029 tree ret;
6038 {
6039 /* Resolve the name. */
6044 }
6050 /* Handle the special case where INSTANCE is NULL_TREE. */
6052 {
6055 }
6056 else
6057 {
6063 /* Convert to the base class, if necessary. */
6066 {
6068 /* For constructors and destructors, either the base is
6069 non-virtual, or it is virtual but we are doing the
6070 conversion from a constructor or destructor for the
6071 complete object. In either case, we can convert
6072 statically. */
6074 else
6075 /* However, for assignment operators, we must convert
6076 dynamically if the base is virtual. */
6079 }
6080 }
6086 /* When making a call to a constructor or destructor for a subobject
6087 that uses virtual base classes, pass down a pointer to a VTT for
6088 the subobject. */
6092 {
6093 tree vtt;
6094 tree sub_vtt;
6096 /* If the current function is a complete object constructor
6097 or destructor, then we fetch the VTT directly.
6098 Otherwise, we look it up using the VTT we were given. */
6104 current_vtt_parm,
6105 vtt);
6111 {
6114 }
6117 }
6122 complain);
6128 }
6130 /* Return the NAME, as a C string. The NAME indicates a function that
6131 is a member of TYPE. *FREE_P is set to true if the caller must
6132 free the memory returned.
6134 Rather than go through all of this, we should simply set the names
6135 of constructors and destructors appropriately, and dispense with
6136 ctor_identifier, dtor_identifier, etc. */
6140 {
6143 /* Assume that we will not allocate memory. */
6145 /* Constructors and destructors are special. */
6147 {
6148 pretty_name
6150 /* For a destructor, add the '~'. */
6154 {
6156 /* Remember that we need to free the memory allocated. */
6158 }
6159 }
6161 {
6164 TFF_PLAIN_IDENTIFIER),
6165 NULL);
6166 /* Remember that we need to free the memory allocated. */
6168 }
6169 else
6173 }
6175 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6176 be set, upon return, to the function called. ARGS may be NULL.
6177 This may change ARGS. */
6179 tree
6183 {
6187 tree access_binfo;
6188 tree optype;
6190 tree instance_ptr;
6191 tree name;
6194 tree call;
6195 tree fn;
6196 tree class_type;
6199 tree orig_instance;
6200 tree orig_fns;
6206 /* We don't know what function we're going to call, yet. */
6215 {
6219 }
6224 /* Dismantle the baselink to collect all the information we need. */
6231 {
6235 }
6246 {
6251 }
6254 /* Under DR 147 A::A() is an invalid constructor call,
6255 not a functional cast. */
6257 {
6267 complain);
6269 }
6271 /* Figure out whether to skip the first argument for the error
6272 message we will display to users if an error occurs. We don't
6273 want to display any compiler-generated arguments. The "this"
6274 pointer hasn't been added yet. However, we must remove the VTT
6275 pointer if this is a call to a base-class constructor or
6276 destructor. */
6279 {
6280 /* Callers should explicitly indicate whether they want to construct
6281 the complete object or just the part without virtual bases. */
6283 /* Similarly for destructors. */
6285 /* Remove the VTT pointer, if present. */
6289 }
6291 /* Process the argument list. */
6293 {
6297 }
6301 /* It's OK to call destructors and constructors on cv-qualified objects.
6302 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6303 necessary. */
6306 {
6310 }
6314 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6315 initializer, not T({ }). If the type doesn't have a list ctor,
6316 break apart the list into separate ctor args. */
6321 {
6324 }
6329 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6333 {
6335 tree this_first_arg;
6337 /* We can end up here for copy-init of same or base class. */
6344 else
6348 /* A member template. */
6350 class_type,
6351 explicit_targs,
6352 this_first_arg,
6354 optype,
6355 access_binfo,
6356 conversion_path,
6357 flags,
6358 DEDUCE_CALL);
6361 class_type,
6362 this_first_arg,
6364 access_binfo,
6365 conversion_path,
6366 flags);
6367 }
6371 {
6373 {
6376 else
6377 {
6380 tree arglist;
6391 }
6393 }
6395 }
6396 else
6397 {
6400 {
6403 tree arglist;
6406 {
6412 arglist);
6416 }
6418 }
6419 else
6420 {
6429 /* This is not an error, it is runtime undefined
6430 behavior. */
6432 "abstract virtual %q#D called from constructor"
6434 fn);
6438 {
6441 fn);
6443 }
6444 else
6445 {
6449 /* Now we know what function is being called. */
6452 /* Build the actual CALL_EXPR. */
6454 /* In an expression of the form `a->f()' where `f' turns
6455 out to be a static member function, `a' is
6456 none-the-less evaluated. */
6465 /* An explicit call of the form "x->~X()" has type
6466 "void". However, on platforms where destructors
6467 return "this" (i.e., those where
6468 targetm.cxx.cdtor_returns_this is true), such calls
6469 will appear to have a return value of pointer type
6470 to the low-level call machinery. We do not want to
6471 change the low-level machinery, since we want to be
6472 able to optimize "delete f()" on such platforms as
6473 "operator delete(~X(f()))" (rather than generating
6474 "t = f(), ~X(t), operator delete (t)"). */
6476 }
6477 }
6478 }
6481 {
6487 {
6490 }
6493 call = (build_min_non_dep_call_vec
6497 orig_args));
6501 }
6503 /* Free all the conversions we allocated. */
6510 }
6512 /* Returns true iff standard conversion sequence ICS1 is a proper
6513 subsequence of ICS2. */
6515 static bool
6517 {
6518 /* We can assume that a conversion of the same code
6519 between the same types indicates a subsequence since we only get
6520 here if the types we are converting from are the same. */
6527 {
6535 /* At this point, ICS1 cannot be a proper subsequence of
6536 ICS2. We can get a USER_CONV when we are comparing the
6537 second standard conversion sequence of two user conversion
6538 sequences. */
6548 }
6549 }
6551 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6552 be any _TYPE nodes. */
6554 bool
6556 {
6560 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6561 considers every class derived from itself. */
6564 }
6566 /* We build the ICS for an implicit object parameter as a pointer
6567 conversion sequence. However, such a sequence should be compared
6568 as if it were a reference conversion sequence. If ICS is the
6569 implicit conversion sequence for an implicit object parameter,
6570 modify it accordingly. */
6572 static void
6574 {
6576 {
6577 /* [over.match.funcs]
6579 For non-static member functions, the type of the
6580 implicit object parameter is "reference to cv X"
6581 where X is the class of which the function is a
6582 member and cv is the cv-qualification on the member
6583 function declaration. */
6585 tree reference_type;
6587 /* The `this' parameter is a pointer to a class type. Make the
6588 implicit conversion talk about a reference to that same class
6589 type. */
6602 }
6603 }
6605 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6606 and return the initial reference binding conversion. Otherwise,
6607 leave *ICS unchanged and return NULL. */
6611 {
6613 {
6618 }
6621 }
6623 /* Compare two implicit conversion sequences according to the rules set out in
6624 [over.ics.rank]. Return values:
6626 1: ics1 is better than ics2
6627 -1: ics2 is better than ics1
6628 0: ics1 and ics2 are indistinguishable */
6630 static int
6632 {
6633 tree from_type1;
6634 tree from_type2;
6635 tree to_type1;
6636 tree to_type2;
6643 /* REF_BINDING is nonzero if the result of the conversion sequence
6644 is a reference type. In that case REF_CONV is the reference
6645 binding conversion. */
6649 /* Handle implicit object parameters. */
6653 /* Handle reference parameters. */
6657 /* List-initialization sequence L1 is a better conversion sequence than
6658 list-initialization sequence L2 if L1 converts to
6659 std::initializer_list<X> for some X and L2 does not. */
6665 /* [over.ics.rank]
6667 When comparing the basic forms of implicit conversion sequences (as
6668 defined in _over.best.ics_)
6670 --a standard conversion sequence (_over.ics.scs_) is a better
6671 conversion sequence than a user-defined conversion sequence
6672 or an ellipsis conversion sequence, and
6674 --a user-defined conversion sequence (_over.ics.user_) is a
6675 better conversion sequence than an ellipsis conversion sequence
6676 (_over.ics.ellipsis_). */
6686 {
6687 /* XXX Isn't this an extension? */
6688 /* Both ICS are bad. We try to make a decision based on what
6689 would have happened if they'd been good. */
6697 /* We couldn't make up our minds; try to figure it out below. */
6698 }
6701 /* Both conversions are ellipsis conversions or both are building a
6702 std::initializer_list. */
6705 /* User-defined conversion sequence U1 is a better conversion sequence
6706 than another user-defined conversion sequence U2 if they contain the
6707 same user-defined conversion operator or constructor and if the sec-
6708 ond standard conversion sequence of U1 is better than the second
6709 standard conversion sequence of U2. */
6712 {
6726 /* We can just fall through here, after setting up
6727 FROM_TYPE1 and FROM_TYPE2. */
6730 }
6731 else
6732 {
6736 /* We're dealing with two standard conversion sequences.
6738 [over.ics.rank]
6740 Standard conversion sequence S1 is a better conversion
6741 sequence than standard conversion sequence S2 if
6743 --S1 is a proper subsequence of S2 (comparing the conversion
6744 sequences in the canonical form defined by _over.ics.scs_,
6745 excluding any Lvalue Transformation; the identity
6746 conversion sequence is considered to be a subsequence of
6747 any non-identity conversion sequence */
6758 }
6760 /* One sequence can only be a subsequence of the other if they start with
6761 the same type. They can start with different types when comparing the
6762 second standard conversion sequence in two user-defined conversion
6763 sequences. */
6765 {
6770 }
6772 /* [over.ics.rank]
6774 Or, if not that,
6776 --the rank of S1 is better than the rank of S2 (by the rules
6777 defined below):
6779 Standard conversion sequences are ordered by their ranks: an Exact
6780 Match is a better conversion than a Promotion, which is a better
6781 conversion than a Conversion.
6783 Two conversion sequences with the same rank are indistinguishable
6784 unless one of the following rules applies:
6786 --A conversion that is not a conversion of a pointer, or pointer
6787 to member, to bool is better than another conversion that is such
6788 a conversion.
6790 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
6791 so that we do not have to check it explicitly. */
6800 /* A conversion from scalar arithmetic type to complex is worse than a
6801 conversion between scalar arithmetic types. */
6808 {
6811 else
6813 }
6819 {
6824 }
6825 /* The rules for pointers to members A::* are just like the rules
6826 for pointers A*, except opposite: if B is derived from A then
6827 A::* converts to B::*, not vice versa. For that reason, we
6828 switch the from_ and to_ variables here. */
6835 {
6840 }
6845 {
6846 /* This was one of the pointer or pointer-like conversions.
6848 [over.ics.rank]
6850 --If class B is derived directly or indirectly from class A,
6851 conversion of B* to A* is better than conversion of B* to
6852 void*, and conversion of A* to void* is better than
6853 conversion of B* to void*. */
6856 {
6858 deref_from_type2))
6861 deref_from_type1))
6863 }
6866 {
6868 {
6870 {
6872 deref_to_type1))
6874 }
6875 /* We know that DEREF_TO_TYPE1 is `void' here. */
6877 deref_to_type2))
6879 }
6880 }
6883 {
6884 /* [over.ics.rank]
6886 --If class B is derived directly or indirectly from class A
6887 and class C is derived directly or indirectly from B,
6889 --conversion of C* to B* is better than conversion of C* to
6890 A*,
6892 --conversion of B* to A* is better than conversion of C* to
6893 A* */
6895 {
6897 deref_to_type2))
6900 deref_to_type1))
6902 }
6904 {
6906 deref_from_type1))
6909 deref_from_type2))
6911 }
6912 }
6913 }
6916 {
6919 /* [over.ics.rank]
6921 --binding of an expression of type C to a reference of type
6922 B& is better than binding an expression of type C to a
6923 reference of type A&
6925 --conversion of C to B is better than conversion of C to A, */
6928 {
6933 }
6934 }
6937 {
6940 /* [over.ics.rank]
6942 --binding of an expression of type B to a reference of type
6943 A& is better than binding an expression of type C to a
6944 reference of type A&,
6946 --conversion of B to A is better than conversion of C to A */
6949 {
6954 }
6955 }
6957 /* [over.ics.rank]
6959 --S1 and S2 differ only in their qualification conversion and yield
6960 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6961 qualification signature of type T1 is a proper subset of the cv-
6962 qualification signature of type T2 */
6966 {
6970 }
6972 /* [over.ics.rank]
6974 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6975 to an implicit object parameter, and either S1 binds an lvalue reference
6976 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6977 reference to an rvalue and S2 binds an lvalue reference
6978 (C++0x draft standard, 13.3.3.2)
6980 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6981 types to which the references refer are the same type except for
6982 top-level cv-qualifiers, and the type to which the reference
6983 initialized by S2 refers is more cv-qualified than the type to
6984 which the reference initialized by S1 refers */
6987 {
6991 {
6996 }
7001 }
7003 /* Neither conversion sequence is better than the other. */
7005 }
7007 /* The source type for this standard conversion sequence. */
7009 static tree
7011 {
7013 {
7018 }
7020 }
7022 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7023 a pointer to LOSER and re-running joust to produce the warning if WINNER
7024 is actually used. */
7026 static void
7028 {
7034 }
7036 /* Compare two candidates for overloading as described in
7037 [over.match.best]. Return values:
7039 1: cand1 is better than cand2
7040 -1: cand2 is better than cand1
7041 0: cand1 and cand2 are indistinguishable */
7043 static int
7045 {
7051 /* Candidates that involve bad conversions are always worse than those
7052 that don't. */
7058 /* If we have two pseudo-candidates for conversions to the same type,
7059 or two candidates for the same function, arbitrarily pick one. */
7064 /* a viable function F1
7065 is defined to be a better function than another viable function F2 if
7066 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7067 ICSi(F2), and then */
7069 /* for some argument j, ICSj(F1) is a better conversion sequence than
7070 ICSj(F2) */
7072 /* For comparing static and non-static member functions, we ignore
7073 the implicit object parameter of the non-static function. The
7074 standard says to pretend that the static function has an object
7075 parm, but that won't work with operator overloading. */
7078 {
7086 else
7087 {
7090 }
7091 }
7094 {
7100 {
7113 {
7120 else
7125 {
7129 }
7130 else
7132 }
7135 {
7138 }
7140 }
7141 }
7143 /* warn about confusing overload resolution for user-defined conversions,
7144 either between a constructor and a conversion op, or between two
7145 conversion ops. */
7149 {
7155 else
7158 /* We don't want to complain about `X::operator T1 ()'
7159 beating `X::operator T2 () const', when T2 is a no less
7160 cv-qualified version of T1. */
7163 {
7168 {
7171 }
7174 }
7175 else
7181 {
7188 {
7190 }
7191 }
7192 else
7194 }
7199 /* or, if not that,
7200 F1 is a non-template function and F2 is a template function
7201 specialization. */
7208 /* or, if not that,
7209 F1 and F2 are template functions and the function template for F1 is
7210 more specialized than the template for F2 according to the partial
7211 ordering rules. */
7214 {
7215 winner = more_specialized_fn
7218 /* [temp.func.order]: The presence of unused ellipsis and default
7219 arguments has no effect on the partial ordering of function
7220 templates. add_function_candidate() will not have
7221 counted the "this" argument for constructors. */
7225 }
7227 /* or, if not that,
7228 the context is an initialization by user-defined conversion (see
7229 _dcl.init_ and _over.match.user_) and the standard conversion
7230 sequence from the return type of F1 to the destination type (i.e.,
7231 the type of the entity being initialized) is a better conversion
7232 sequence than the standard conversion sequence from the return type
7233 of F2 to the destination type. */
7236 {
7240 }
7242 /* Check whether we can discard a builtin candidate, either because we
7243 have two identical ones or matching builtin and non-builtin candidates.
7245 (Pedantically in the latter case the builtin which matched the user
7246 function should not be added to the overload set, but we spot it here.
7248 [over.match.oper]
7249 ... the builtin candidates include ...
7250 - do not have the same parameter type list as any non-template
7251 non-member candidate. */
7255 {
7261 {
7263 /* Two built-in candidates; arbitrarily pick one. */
7266 /* cand1 is built-in; prefer cand2. */
7268 else
7269 /* cand2 is built-in; prefer cand1. */
7271 }
7272 }
7274 /* If the two function declarations represent the same function (this can
7275 happen with declarations in multiple scopes and arg-dependent lookup),
7276 arbitrarily choose one. But first make sure the default args we're
7277 using match. */
7280 {
7287 {
7288 /* Don't crash if the fn is variadic. */
7293 }
7301 {
7304 {
7306 {
7313 }
7314 else
7317 }
7320 }
7323 }
7325 tweak:
7327 /* Extension: If the worst conversion for one candidate is worse than the
7328 worst conversion for the other, take the first. */
7330 {
7335 {
7340 }
7346 {
7348 {
7350 "ISO C++ says that these are ambiguous, even "
7351 "though the worst conversion for the first is better than "
7355 }
7356 else
7359 }
7360 }
7364 }
7366 /* Given a list of candidates for overloading, find the best one, if any.
7367 This algorithm has a worst case of O(2n) (winner is last), and a best
7368 case of O(n/2) (totally ambiguous); much better than a sorting
7369 algorithm. */
7373 {
7378 /* Walk through the list once, comparing each current champ to the next
7379 candidate, knocking out a candidate or two with each comparison. */
7382 {
7386 else
7387 {
7389 {
7394 }
7395 else
7396 {
7399 }
7402 }
7403 }
7405 /* Make sure the champ is better than all the candidates it hasn't yet
7406 been compared to. */
7409 challenger != champ
7412 {
7416 }
7419 }
7421 /* Returns nonzero if things of type FROM can be converted to TO. */
7423 bool
7425 {
7427 }
7429 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7431 bool
7433 {
7438 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7442 flags);
7445 /* Free all the conversions we allocated. */
7449 }
7451 /* Like can_convert_arg, but allows dubious conversions as well. */
7453 bool
7455 {
7459 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7461 /* Try to perform the conversion. */
7463 flags);
7464 /* Free all the conversions we allocated. */
7468 }
7470 /* Convert EXPR to TYPE. Return the converted expression.
7472 Note that we allow bad conversions here because by the time we get to
7473 this point we are committed to doing the conversion. If we end up
7474 doing a bad conversion, convert_like will complain. */
7476 tree
7478 {
7485 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7490 flags);
7493 {
7495 {
7496 /* If expr has unknown type, then it is an overloaded function.
7497 Call instantiate_type to get good error messages. */
7502 else
7504 }
7506 }
7508 {
7509 /* In a template, we are only concerned about determining the
7510 type of non-dependent expressions, so we do not have to
7511 perform the actual conversion. */
7514 }
7515 else
7518 /* Free all the conversions we allocated. */
7522 }
7524 tree
7526 {
7528 }
7530 /* Convert EXPR to TYPE (as a direct-initialization) if that is
7531 permitted. If the conversion is valid, the converted expression is
7532 returned. Otherwise, NULL_TREE is returned, except in the case
7533 that TYPE is a class type; in that case, an error is issued. If
7534 C_CAST_P is true, then this direction initialization is taking
7535 place as part of a static_cast being attempted as part of a C-style
7536 cast. */
7538 tree
7540 tree expr,
7542 tsubst_flags_t complain)
7543 {
7549 /* [dcl.init]
7551 If the destination type is a (possibly cv-qualified) class type:
7553 -- If the initialization is direct-initialization ...,
7554 constructors are considered. ... If no constructor applies, or
7555 the overload resolution is ambiguous, the initialization is
7556 ill-formed. */
7558 {
7564 }
7566 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7570 c_cast_p,
7571 LOOKUP_NORMAL);
7574 else
7577 c_cast_p,
7578 tf_warning_or_error);
7580 /* Free all the conversions we allocated. */
7584 }
7586 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
7587 is being bound to a temporary. Create and return a new VAR_DECL
7588 with the indicated TYPE; this variable will store the value to
7589 which the reference is bound. */
7591 tree
7593 {
7594 tree var;
7596 /* Create the variable. */
7599 /* Register the variable. */
7601 {
7602 /* Namespace-scope or local static; give it a mangled name. */
7603 tree name;
7610 }
7611 else
7612 /* Create a new cleanup level if necessary. */
7616 }
7618 /* EXPR is the initializer for a variable DECL of reference or
7619 std::initializer_list type. Create, push and return a new VAR_DECL
7620 for the initializer so that it will live as long as DECL. Any
7621 cleanup for the new variable is returned through CLEANUP, and the
7622 code to initialize the new variable is returned through INITP. */
7624 tree
7626 {
7627 tree init;
7628 tree type;
7629 tree var;
7631 /* Create the temporary variable. */
7635 /* If the rvalue is the result of a function call it will be
7636 a TARGET_EXPR. If it is some other construct (such as a
7637 member access expression where the underlying object is
7638 itself the result of a function call), turn it into a
7639 TARGET_EXPR here. It is important that EXPR be a
7640 TARGET_EXPR below since otherwise the INIT_EXPR will
7641 attempt to make a bitwise copy of EXPR to initialize
7642 VAR. */
7645 /* Create the INIT_EXPR that will initialize the temporary
7646 variable. */
7649 {
7654 else
7657 /* We must be careful to destroy the temporary only
7658 after its initialization has taken place. If the
7659 initialization throws an exception, then the
7660 destructor should not be run. We cannot simply
7661 transform INIT into something like:
7663 (INIT, ({ CLEANUP_STMT; }))
7665 because emit_local_var always treats the
7666 initializer as a full-expression. Thus, the
7667 destructor would run too early; it would run at the
7668 end of initializing the reference variable, rather
7669 than at the end of the block enclosing the
7670 reference variable.
7672 The solution is to pass back a cleanup expression
7673 which the caller is responsible for attaching to
7674 the statement tree. */
7675 }
7676 else
7677 {
7681 static_aggregates);
7682 }
7686 }
7688 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
7689 initializing a variable of that TYPE. If DECL is non-NULL, it is
7690 the VAR_DECL being initialized with the EXPR. (In that case, the
7691 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
7692 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
7693 return, if *CLEANUP is no longer NULL, it will be an expression
7694 that should be pushed as a cleanup after the returned expression
7695 is used to initialize DECL.
7697 Return the converted expression. */
7699 tree
7701 tsubst_flags_t complain)
7702 {
7709 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7713 LOOKUP_NORMAL);
7715 {
7717 {
7724 else
7728 }
7730 }
7732 /* If DECL is non-NULL, then this special rule applies:
7734 [class.temporary]
7736 The temporary to which the reference is bound or the temporary
7737 that is the complete object to which the reference is bound
7738 persists for the lifetime of the reference.
7740 The temporaries created during the evaluation of the expression
7741 initializing the reference, except the temporary to which the
7742 reference is bound, are destroyed at the end of the
7743 full-expression in which they are created.
7745 In that case, we store the converted expression into a new
7746 VAR_DECL in a new scope.
7748 However, we want to be careful not to create temporaries when
7749 they are not required. For example, given:
7751 struct B {};
7752 struct D : public B {};
7753 D f();
7754 const B& b = f();
7756 there is no need to copy the return value from "f"; we can just
7757 extend its lifetime. Similarly, given:
7759 struct S {};
7760 struct T { operator S(); };
7761 T t;
7762 const S& s = t;
7764 we can extend the lifetime of the return value of the conversion
7765 operator. */
7768 {
7769 tree var;
7770 tree base_conv_type;
7772 /* Skip over the REF_BIND. */
7774 /* If the next conversion is a BASE_CONV, skip that too -- but
7775 remember that the conversion was required. */
7777 {
7780 }
7781 else
7783 /* Perform the remainder of the conversion. */
7789 tf_warning_or_error);
7792 else
7793 {
7795 {
7796 tree init;
7798 /* Use its address to initialize the reference variable. */
7806 }
7807 else
7808 /* Take the address of EXPR. */
7810 /* If a BASE_CONV was required, perform it now. */
7812 expr = (perform_implicit_conversion
7814 tf_warning_or_error));
7816 }
7817 }
7818 else
7819 /* Perform the conversion. */
7822 /* Free all the conversions we allocated. */
7826 }
7828 /* Returns true iff TYPE is some variant of std::initializer_list. */
7830 bool
7832 {
7836 }
7838 /* Returns true iff DECL is a list constructor: i.e. a constructor which
7839 will accept an argument list of a single std::initializer_list<T>. */
7841 bool
7843 {
7845 tree arg;
7857 /* There are more non-defaulted parms. */
7861 }