| blob | dc90d1952e10d94e3d183fb4d1c5301b7fc97ce9 |
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
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_rvalue
60 /* The rank of the conversion. Order of the enumerals matters; better
61 conversions should come earlier in the list. */
64 cr_identity,
65 cr_exact,
66 cr_promotion,
67 cr_std,
68 cr_pbool,
69 cr_user,
70 cr_ellipsis,
71 cr_bad
74 /* An implicit conversion sequence, in the sense of [over.best.ics].
75 The first conversion to be performed is at the end of the chain.
76 That conversion is always a cr_identity conversion. */
80 /* The kind of conversion represented by this step. */
81 conversion_kind kind;
82 /* The rank of this conversion. */
83 conversion_rank rank;
88 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
89 temporary should be created to hold the result of the
90 conversion. */
92 /* If KIND is ck_identity or ck_base_conv, true to indicate that the
93 copy constructor must be accessible, even though it is not being
94 used. */
96 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
97 from a pointer-to-derived to pointer-to-base is being performed. */
99 /* If KIND is ck_ref_bind, true when either an lvalue reference is
100 being bound to an lvalue expression or an rvalue reference is
101 being bound to an rvalue expression. */
103 /* The type of the expression resulting from the conversion. */
104 tree type;
106 /* The next conversion in the chain. Since the conversions are
107 arranged from outermost to innermost, the NEXT conversion will
108 actually be performed before this conversion. This variant is
109 used only when KIND is neither ck_identity nor ck_ambig. */
111 /* The expression at the beginning of the conversion chain. This
112 variant is used only if KIND is ck_identity or ck_ambig. */
113 tree expr;
115 /* The function candidate corresponding to this conversion
116 sequence. This field is only used if KIND is ck_user. */
118 };
120 #define CONVERSION_RANK(NODE) \
121 ((NODE)->bad_p ? cr_bad \
122 : (NODE)->ellipsis_p ? cr_ellipsis \
123 : (NODE)->user_conv_p ? cr_user \
124 : (NODE)->rank)
135 #define convert_like(CONV, EXPR) \
136 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
139 #define convert_like_with_context(CONV, EXPR, FN, ARGNO) \
140 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
163 static void add_builtin_candidates
166 static void add_builtin_candidate
170 static void build_builtin_candidate
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 {
226 else
228 }
229 else
230 {
231 /* In the case of:
233 template <class T> struct S { ~S(); };
234 int i;
235 i.~S();
237 NAME will be a class template. */
240 }
245 }
247 /* We want the address of a function or method. We avoid creating a
248 pointer-to-member function. */
250 tree
252 {
255 /* We have to do these by hand to avoid real pointer to member
256 functions. */
258 {
260 {
264 }
266 }
267 else
271 }
273 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
274 POINTER_TYPE to those. Note, pointer to member function types
275 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
276 two variants. build_call_a is the primitive taking an array of
277 arguments, while build_call_n is a wrapper that handles varargs. */
279 tree
281 {
284 else
285 {
295 }
296 }
298 tree
300 {
303 tree decl;
304 tree result_type;
305 tree fntype;
318 {
321 {
322 /* We invoke build_call directly for several library
323 functions. These may have been declared normally if
324 we're building libgcc, so we can't just check
325 DECL_ARTIFICIAL. */
330 }
331 }
332 else
335 /* We check both the decl and the type; a function may be known not to
336 throw without being declared throw(). */
350 /* Don't pass empty class objects by value. This is useful
351 for tags in STL, which are used to control overload resolution.
352 We don't need to handle other cases of copying empty classes. */
357 {
361 }
368 }
370 /* Build something of the form ptr->method (args)
371 or object.method (args). This can also build
372 calls to constructors, and find friends.
374 Member functions always take their class variable
375 as a pointer.
377 INSTANCE is a class instance.
379 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
381 PARMS help to figure out what that NAME really refers to.
383 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
384 down to the real instance type to use for access checking. We need this
385 information to get protected accesses correct.
387 FLAGS is the logical disjunction of zero or more LOOKUP_
388 flags. See cp-tree.h for more info.
390 If this is all OK, calls build_function_call with the resolved
391 member function.
393 This function must also handle being called to perform
394 initialization, promotion/coercion of arguments, and
395 instantiation of default parameters.
397 Note that NAME may refer to an instance variable name. If
398 `operator()()' is defined for the type of that field, then we return
399 that result. */
401 /* New overloading code. */
409 };
412 /* The FUNCTION_DECL that will be called if this candidate is
413 selected by overload resolution. */
414 tree fn;
415 /* The arguments to use when calling this function. */
416 tree args;
417 /* The implicit conversion sequences for each of the arguments to
418 FN. */
420 /* The number of implicit conversion sequences. */
422 /* If FN is a user-defined conversion, the standard conversion
423 sequence from the type returned by FN to the desired destination
424 type. */
427 /* If FN is a member function, the binfo indicating the path used to
428 qualify the name of FN at the call site. This path is used to
429 determine whether or not FN is accessible if it is selected by
430 overload resolution. The DECL_CONTEXT of FN will always be a
431 (possibly improper) base of this binfo. */
432 tree access_path;
433 /* If FN is a non-static member function, the binfo indicating the
434 subobject to which the `this' pointer should be converted if FN
435 is selected by overload resolution. The type pointed to the by
436 the `this' pointer must correspond to the most derived class
437 indicated by the CONVERSION_PATH. */
438 tree conversion_path;
439 tree template_decl;
442 };
444 /* Returns true iff T is a null pointer constant in the sense of
445 [conv.ptr]. */
447 bool
449 {
450 /* [conv.ptr]
452 A null pointer constant is an integral constant expression
453 (_expr.const_) rvalue of integer type that evaluates to zero. */
458 {
462 }
464 }
466 /* Returns nonzero if PARMLIST consists of only default parms and/or
467 ellipsis. */
469 bool
471 {
477 }
479 /* Allocate N bytes of memory from the conversion obstack. The memory
480 is zeroed before being returned. */
484 {
487 {
490 }
494 }
496 /* Dynamically allocate a conversion. */
500 {
505 }
507 #ifdef ENABLE_CHECKING
509 /* Make sure that all memory on the conversion obstack has been
510 freed. */
512 void
514 {
518 }
522 /* Dynamically allocate an array of N conversions. */
526 {
528 }
532 {
536 /* We can't use buildl1 here because CODE could be USER_CONV, which
537 takes two arguments. In that case, the caller is responsible for
538 filling in the second argument. */
544 {
560 }
566 }
568 /* Build a representation of the identity conversion from EXPR to
569 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
573 {
581 }
583 /* Converting from EXPR to TYPE was ambiguous in the sense that there
584 were multiple user-defined conversions to accomplish the job.
585 Build a conversion that indicates that ambiguity. */
589 {
597 }
599 tree
601 {
605 }
607 /* Returns the standard conversion path (see [conv]) from type FROM to type
608 TO, if any. For proper handling of null pointer constants, you must
609 also pass the expression EXPR to convert from. If C_CAST_P is true,
610 this conversion is coming from a C-style cast. */
615 {
622 {
625 }
631 {
636 }
643 {
647 }
649 {
651 {
652 tree bitfield_type;
655 {
658 }
659 }
661 }
663 /* Allow conversion between `__complex__' data types. */
665 {
666 /* The standard conversion sequence to convert FROM to TO is
667 the standard conversion sequence to perform componentwise
668 conversion. */
673 {
676 }
677 else
681 }
691 {
692 /* For backwards brain damage compatibility, allow interconversion of
693 pointers and integers with a pedwarn. */
696 }
698 {
699 /* For backwards brain damage compatibility, allow interconversion of
700 enums and integers with a pedwarn. */
703 }
706 {
707 tree to_pointee;
708 tree from_pointee;
713 ;
717 {
718 from = build_pointer_type
722 }
724 {
729 && (same_type_ignoring_top_level_qualifiers_p
732 {
736 }
739 }
742 /* [conv.ptr]
744 An rvalue of type "pointer to cv D," where D is a
745 class type, can be converted to an rvalue of type
746 "pointer to cv B," where B is a base class (clause
747 _class.derived_) of D. If B is an inaccessible
748 (clause _class.access_) or ambiguous
749 (_class.member.lookup_) base class of D, a program
750 that necessitates this conversion is ill-formed.
751 Therefore, we use DERIVED_FROM_P, and do not check
752 access or uniqueness. */
754 /* If FROM is not yet complete, then we must be parsing
755 the body of a class. We know what's derived from
756 what, but we can't actually perform a
757 derived-to-base conversion. For example, in:
759 struct D : public B {
760 static const int i = sizeof((B*)(D*)0);
761 };
763 the D*-to-B* conversion is a reinterpret_cast, not a
764 static_cast. */
766 {
767 from =
773 }
776 {
779 }
780 else
781 {
784 }
789 /* In a C-style cast, we ignore CV-qualification because we
790 are allowed to perform a static_cast followed by a
791 const_cast. */
796 /* converting from string constant to char *. */
799 {
802 }
803 else
807 }
809 {
829 }
831 {
832 /* [conv.bool]
834 An rvalue of arithmetic, enumeration, pointer, or pointer to
835 member type can be converted to an rvalue of type bool. */
840 {
848 }
851 }
852 /* We don't check for ENUMERAL_TYPE here because there are no standard
853 conversions to enum type. */
856 {
861 /* Give this a better rank if it's a promotion. */
865 }
872 {
876 /* The derived-to-base conversion indicates the initialization
877 of a parameter with base type from an object of a derived
878 type. A temporary object is created to hold the result of
879 the conversion. */
881 }
882 else
886 }
888 /* Returns nonzero if T1 is reference-related to T2. */
890 static bool
892 {
896 /* [dcl.init.ref]
898 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
899 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
900 of T2. */
904 }
906 /* Returns nonzero if T1 is reference-compatible with T2. */
908 static bool
910 {
911 /* [dcl.init.ref]
913 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
914 reference-related to T2 and cv1 is the same cv-qualification as,
915 or greater cv-qualification than, cv2. */
918 }
920 /* Determine whether or not the EXPR (of class type S) can be
921 converted to T as in [over.match.ref]. */
925 {
926 tree conversions;
927 tree arglist;
929 tree t;
938 /* [over.match.ref]
940 Assuming that "cv1 T" is the underlying type of the reference
941 being initialized, and "cv S" is the type of the initializer
942 expression, with S a class type, the candidate functions are
943 selected as follows:
945 --The conversion functions of S and its base classes are
946 considered. Those that are not hidden within S and yield type
947 "reference to cv2 T2", where "cv1 T" is reference-compatible
948 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
950 The argument list has one argument, which is the initializer
951 expression. */
955 /* Conceptually, we should take the address of EXPR and put it in
956 the argument list. Unfortunately, however, that can result in
957 error messages, which we should not issue now because we are just
958 trying to find a conversion operator. Therefore, we use NULL,
959 cast to the appropriate type. */
966 {
970 {
976 /* If this is a template function, try to get an exact
977 match. */
979 {
982 NULL_TREE,
983 arglist,
984 reference_type,
987 LOOKUP_NORMAL,
988 DEDUCE_CONV);
991 {
992 /* Now, see if the conversion function really returns
993 an lvalue of the appropriate type. From the
994 point of view of unification, simply returning an
995 rvalue of the right type is good enough. */
1000 {
1003 }
1004 }
1005 }
1011 LOOKUP_NORMAL);
1014 {
1016 /* Build a standard conversion sequence indicating the
1017 binding from the reference type returned by the
1018 function to the desired REFERENCE_TYPE. */
1019 identity_conv
1022 NULL_TREE);
1023 cand->second_conv
1024 = (direct_reference_binding
1030 }
1031 }
1033 }
1036 /* If none of the conversion functions worked out, let our caller
1037 know. */
1045 /* Now that we know that this is the function we're going to use fix
1046 the dummy first argument. */
1051 /* Build a user-defined conversion sequence representing the
1052 conversion. */
1058 /* Merge it with the standard conversion sequence from the
1059 conversion function's return type to the desired type. */
1066 }
1068 /* A reference of the indicated TYPE is being bound directly to the
1069 expression represented by the implicit conversion sequence CONV.
1070 Return a conversion sequence for this binding. */
1074 {
1075 tree t;
1082 /* [over.ics.rank]
1084 When a parameter of reference type binds directly
1085 (_dcl.init.ref_) to an argument expression, the implicit
1086 conversion sequence is the identity conversion, unless the
1087 argument expression has a type that is a derived class of the
1088 parameter type, in which case the implicit conversion sequence is
1089 a derived-to-base Conversion.
1091 If the parameter binds directly to the result of applying a
1092 conversion function to the argument expression, the implicit
1093 conversion sequence is a user-defined conversion sequence
1094 (_over.ics.user_), with the second standard conversion sequence
1095 either an identity conversion or, if the conversion function
1096 returns an entity of a type that is a derived class of the
1097 parameter type, a derived-to-base conversion. */
1099 {
1100 /* Represent the derived-to-base conversion. */
1102 /* We will actually be binding to the base-class subobject in
1103 the derived class, so we mark this conversion appropriately.
1104 That way, convert_like knows not to generate a temporary. */
1106 }
1108 }
1110 /* Returns the conversion path from type FROM to reference type TO for
1111 purposes of reference binding. For lvalue binding, either pass a
1112 reference type to FROM or an lvalue expression to EXPR. If the
1113 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1114 the conversion returned. If C_CAST_P is true, this
1115 conversion is coming from a C-style cast. */
1119 {
1128 {
1133 }
1136 {
1137 /* Anything with reference type is an lvalue. */
1140 }
1144 /* Figure out whether or not the types are reference-related and
1145 reference compatible. We have do do this after stripping
1146 references from FROM. */
1148 /* If this is a C cast, first convert to an appropriately qualified
1149 type, so that we can later do a const_cast to the desired type. */
1155 /* Directly bind reference when target expression's type is compatible with
1156 the reference and expression is an lvalue. In C++0x, the wording in
1157 [8.5.3/5 dcl.init.ref] is changed to also allow direct bindings for const
1158 and rvalue references to rvalues of compatible class type, as part of
1159 DR391. */
1161 && (lvalue_p
1165 {
1166 /* [dcl.init.ref]
1168 If the initializer expression
1170 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1171 is reference-compatible with "cv2 T2,"
1173 the reference is bound directly to the initializer expression
1174 lvalue. */
1179 /* The top-level caller requested that we pretend that the lvalue
1180 be treated as an rvalue. */
1182 else
1183 conv->rvaluedness_matches_p
1188 /* For the purposes of overload resolution, we ignore the fact
1189 this expression is a bitfield or packed field. (In particular,
1190 [over.ics.ref] says specifically that a function with a
1191 non-const reference parameter is viable even if the
1192 argument is a bitfield.)
1194 However, when we actually call the function we must create
1195 a temporary to which to bind the reference. If the
1196 reference is volatile, or isn't const, then we cannot make
1197 a temporary, so we just issue an error when the conversion
1198 actually occurs. */
1202 }
1203 /* [class.conv.fct] A conversion function is never used to convert a
1204 (possibly cv-qualified) object to the (possibly cv-qualified) same
1205 object type (or a reference to it), to a (possibly cv-qualified) base
1206 class of that type (or a reference to it).... */
1209 {
1210 /* [dcl.init.ref]
1212 If the initializer expression
1214 -- has a class type (i.e., T2 is a class type) can be
1215 implicitly converted to an lvalue of type "cv3 T3," where
1216 "cv1 T1" is reference-compatible with "cv3 T3". (this
1217 conversion is selected by enumerating the applicable
1218 conversion functions (_over.match.ref_) and choosing the
1219 best one through overload resolution. (_over.match_).
1221 the reference is bound to the lvalue result of the conversion
1222 in the second case. */
1226 }
1228 /* From this point on, we conceptually need temporaries, even if we
1229 elide them. Only the cases above are "direct bindings". */
1233 /* [over.ics.rank]
1235 When a parameter of reference type is not bound directly to an
1236 argument expression, the conversion sequence is the one required
1237 to convert the argument expression to the underlying type of the
1238 reference according to _over.best.ics_. Conceptually, this
1239 conversion sequence corresponds to copy-initializing a temporary
1240 of the underlying type with the argument expression. Any
1241 difference in top-level cv-qualification is subsumed by the
1242 initialization itself and does not constitute a conversion. */
1244 /* [dcl.init.ref]
1246 Otherwise, the reference shall be to a non-volatile const type.
1248 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1252 /* [dcl.init.ref]
1254 If the initializer expression is an rvalue, with T2 a class type,
1255 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1256 is bound in one of the following ways:
1258 -- The reference is bound to the object represented by the rvalue
1259 or to a sub-object within that object.
1261 -- ...
1263 We use the first alternative. The implicit conversion sequence
1264 is supposed to be same as we would obtain by generating a
1265 temporary. Fortunately, if the types are reference compatible,
1266 then this is either an identity conversion or the derived-to-base
1267 conversion, just as for direct binding. */
1269 {
1276 }
1278 /* [dcl.init.ref]
1280 Otherwise, a temporary of type "cv1 T1" is created and
1281 initialized from the initializer expression using the rules for a
1282 non-reference copy initialization. If T1 is reference-related to
1283 T2, cv1 must be the same cv-qualification as, or greater
1284 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1289 flags);
1294 /* This reference binding, unlike those above, requires the
1295 creation of a temporary. */
1300 }
1302 /* Returns the implicit conversion sequence (see [over.ics]) from type
1303 FROM to type TO. The optional expression EXPR may affect the
1304 conversion. FLAGS are the usual overloading flags. Only
1305 LOOKUP_NO_CONVERSION is significant. If C_CAST_P is true, this
1306 conversion is coming from a C-style cast. */
1311 {
1320 else
1330 {
1333 cand = build_user_type_conversion_1
1338 /* We used to try to bind a reference to a temporary here, but that
1339 is now handled after the recursive call to this function at the end
1340 of reference_binding. */
1342 }
1345 }
1347 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1348 functions. */
1356 {
1371 }
1373 /* Create an overload candidate for the function or method FN called with
1374 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1375 to implicit_conversion.
1377 CTYPE, if non-NULL, is the type we want to pretend this function
1378 comes from for purposes of overload resolution. */
1385 {
1390 tree orig_arglist;
1393 /* At this point we should not see any functions which haven't been
1394 explicitly declared, except for friend functions which will have
1395 been found using argument dependent lookup. */
1398 /* The `this', `in_chrg' and VTT arguments to constructors are not
1399 considered in overload resolution. */
1401 {
1405 }
1406 else
1412 /* 13.3.2 - Viable functions [over.match.viable]
1413 First, to be a viable function, a candidate function shall have enough
1414 parameters to agree in number with the arguments in the list.
1416 We need to check this first; otherwise, checking the ICSes might cause
1417 us to produce an ill-formed template instantiation. */
1421 {
1425 }
1430 /* Make sure there are default args for the rest of the parms. */
1437 /* Second, for F to be a viable function, there shall exist for each
1438 argument an implicit conversion sequence that converts that argument
1439 to the corresponding parameter of F. */
1445 {
1458 {
1461 /* The type of the implicit object parameter ('this') for
1462 overload resolution is not always the same as for the
1463 function itself; conversion functions are considered to
1464 be members of the class being converted, and functions
1465 introduced by a using-declaration are considered to be
1466 members of the class that uses them.
1468 Since build_over_call ignores the ICS for the `this'
1469 parameter, we can just change the parm type. */
1471 {
1472 parmtype
1476 }
1480 }
1481 else
1482 {
1485 }
1492 {
1495 }
1503 }
1505 out:
1508 }
1510 /* Create an overload candidate for the conversion function FN which will
1511 be invoked for expression OBJ, producing a pointer-to-function which
1512 will in turn be called with the argument list ARGLIST, and add it to
1513 CANDIDATES. FLAGS is passed on to implicit_conversion.
1515 Actually, we don't really care about FN; we care about the type it
1516 converts to. There may be multiple conversion functions that will
1517 convert to that type, and we rely on build_user_type_conversion_1 to
1518 choose the best one; so when we create our candidate, we record the type
1519 instead of the function. */
1524 {
1541 /* Don't bother looking up the same type twice. */
1546 {
1553 flags);
1559 else
1560 {
1563 }
1578 }
1588 }
1590 static void
1594 {
1608 {
1615 {
1617 /* We need something for printing the candidate. */
1619 }
1623 }
1625 /* For COND_EXPR we rearranged the arguments; undo that now. */
1627 {
1634 else
1636 }
1642 viable);
1643 }
1645 static bool
1647 {
1649 }
1651 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1653 static bool
1655 {
1656 /* [over.built]
1658 In this section, the term promoted integral type is used to refer
1659 to those integral types which are preserved by integral promotion
1660 (including e.g. int and long but excluding e.g. char).
1661 Similarly, the term promoted arithmetic type refers to promoted
1662 integral types plus floating types. */
1666 }
1668 /* Create any builtin operator overload candidates for the operator in
1669 question given the converted operand types TYPE1 and TYPE2. The other
1670 args are passed through from add_builtin_candidates to
1671 build_builtin_candidate.
1673 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1674 If CODE is requires candidates operands of the same type of the kind
1675 of which TYPE1 and TYPE2 are, we add both candidates
1676 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1678 static void
1682 {
1684 {
1692 }
1695 {
1697 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1698 and VQ is either volatile or empty, there exist candidate operator
1699 functions of the form
1700 VQ T& operator++(VQ T&);
1701 T operator++(VQ T&, int);
1702 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1703 type other than bool, and VQ is either volatile or empty, there exist
1704 candidate operator functions of the form
1705 VQ T& operator--(VQ T&);
1706 T operator--(VQ T&, int);
1707 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1708 complete object type, and VQ is either volatile or empty, there exist
1709 candidate operator functions of the form
1710 T*VQ& operator++(T*VQ&);
1711 T*VQ& operator--(T*VQ&);
1712 T* operator++(T*VQ&, int);
1713 T* operator--(T*VQ&, int); */
1722 {
1725 }
1728 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1729 exist candidate operator functions of the form
1731 T& operator*(T*);
1733 8 For every function type T, there exist candidate operator functions of
1734 the form
1735 T& operator*(T*); */
1744 /* 9 For every type T, there exist candidate operator functions of the form
1745 T* operator+(T*);
1747 10For every promoted arithmetic type T, there exist candidate operator
1748 functions of the form
1749 T operator+(T);
1750 T operator-(T); */
1760 /* 11For every promoted integral type T, there exist candidate operator
1761 functions of the form
1762 T operator~(T); */
1769 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1770 is the same type as C2 or is a derived class of C2, T is a complete
1771 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1772 there exist candidate operator functions of the form
1773 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1774 where CV12 is the union of CV1 and CV2. */
1779 {
1787 }
1790 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1791 didate operator functions of the form
1792 LR operator*(L, R);
1793 LR operator/(L, R);
1794 LR operator+(L, R);
1795 LR operator-(L, R);
1796 bool operator<(L, R);
1797 bool operator>(L, R);
1798 bool operator<=(L, R);
1799 bool operator>=(L, R);
1800 bool operator==(L, R);
1801 bool operator!=(L, R);
1802 where LR is the result of the usual arithmetic conversions between
1803 types L and R.
1805 14For every pair of types T and I, where T is a cv-qualified or cv-
1806 unqualified complete object type and I is a promoted integral type,
1807 there exist candidate operator functions of the form
1808 T* operator+(T*, I);
1809 T& operator[](T*, I);
1810 T* operator-(T*, I);
1811 T* operator+(I, T*);
1812 T& operator[](I, T*);
1814 15For every T, where T is a pointer to complete object type, there exist
1815 candidate operator functions of the form112)
1816 ptrdiff_t operator-(T, T);
1818 16For every pointer or enumeration type T, there exist candidate operator
1819 functions of the form
1820 bool operator<(T, T);
1821 bool operator>(T, T);
1822 bool operator<=(T, T);
1823 bool operator>=(T, T);
1824 bool operator==(T, T);
1825 bool operator!=(T, T);
1827 17For every pointer to member type T, there exist candidate operator
1828 functions of the form
1829 bool operator==(T, T);
1830 bool operator!=(T, T); */
1836 {
1839 }
1852 {
1855 }
1857 {
1860 }
1861 /* Fall through. */
1878 {
1881 }
1885 {
1888 }
1896 {
1899 }
1901 {
1904 }
1907 /* 18For every pair of promoted integral types L and R, there exist candi-
1908 date operator functions of the form
1909 LR operator%(L, R);
1910 LR operator&(L, R);
1911 LR operator^(L, R);
1912 LR operator|(L, R);
1913 L operator<<(L, R);
1914 L operator>>(L, R);
1915 where LR is the result of the usual arithmetic conversions between
1916 types L and R. */
1928 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
1929 type, VQ is either volatile or empty, and R is a promoted arithmetic
1930 type, there exist candidate operator functions of the form
1931 VQ L& operator=(VQ L&, R);
1932 VQ L& operator*=(VQ L&, R);
1933 VQ L& operator/=(VQ L&, R);
1934 VQ L& operator+=(VQ L&, R);
1935 VQ L& operator-=(VQ L&, R);
1937 20For every pair T, VQ), where T is any type and VQ is either volatile
1938 or empty, there exist candidate operator functions of the form
1939 T*VQ& operator=(T*VQ&, T*);
1941 21For every pair T, VQ), where T is a pointer to member type and VQ is
1942 either volatile or empty, there exist candidate operator functions of
1943 the form
1944 VQ T& operator=(VQ T&, T);
1946 22For every triple T, VQ, I), where T is a cv-qualified or cv-
1947 unqualified complete object type, VQ is either volatile or empty, and
1948 I is a promoted integral type, there exist candidate operator func-
1949 tions of the form
1950 T*VQ& operator+=(T*VQ&, I);
1951 T*VQ& operator-=(T*VQ&, I);
1953 23For every triple L, VQ, R), where L is an integral or enumeration
1954 type, VQ is either volatile or empty, and R is a promoted integral
1955 type, there exist candidate operator functions of the form
1957 VQ L& operator%=(VQ L&, R);
1958 VQ L& operator<<=(VQ L&, R);
1959 VQ L& operator>>=(VQ L&, R);
1960 VQ L& operator&=(VQ L&, R);
1961 VQ L& operator^=(VQ L&, R);
1962 VQ L& operator|=(VQ L&, R); */
1966 {
1970 {
1973 }
1999 {
2002 }
2007 }
2012 /* [over.built]
2014 For every pair of promoted arithmetic types L and R, there
2015 exist candidate operator functions of the form
2017 LR operator?(bool, L, R);
2019 where LR is the result of the usual arithmetic conversions
2020 between types L and R.
2022 For every type T, where T is a pointer or pointer-to-member
2023 type, there exist candidate operator functions of the form T
2024 operator?(bool, T, T); */
2028 /* That's OK. */
2031 /* Otherwise, the types should be pointers. */
2036 /* We don't check that the two types are the same; the logic
2037 below will actually create two candidates; one in which both
2038 parameter types are TYPE1, and one in which both parameter
2039 types are TYPE2. */
2044 }
2046 /* If we're dealing with two pointer types or two enumeral types,
2047 we need candidates for both of them. */
2056 {
2057 build_builtin_candidate
2059 build_builtin_candidate
2062 }
2064 build_builtin_candidate
2066 }
2068 tree
2070 {
2076 }
2078 /* There are three conditions of builtin candidates:
2080 1) bool-taking candidates. These are the same regardless of the input.
2081 2) pointer-pair taking candidates. These are generated for each type
2082 one of the input types converts to.
2083 3) arithmetic candidates. According to the standard, we should generate
2084 all of these, but I'm trying not to...
2086 Here we generate a superset of the possible candidates for this particular
2087 case. That is a subset of the full set the standard defines, plus some
2088 other cases which the standard disallows. add_builtin_candidate will
2089 filter out the invalid set. */
2091 static void
2095 {
2099 /* TYPES[i] is the set of possible builtin-operator parameter types
2100 we will consider for the Ith argument. These are represented as
2101 a TREE_LIST; the TREE_VALUE of each node is the potential
2102 parameter type. */
2106 {
2109 else
2111 }
2114 {
2115 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2116 and VQ is either volatile or empty, there exist candidate operator
2117 functions of the form
2118 VQ T& operator++(VQ T&); */
2128 /* 24There also exist candidate operator functions of the form
2129 bool operator!(bool);
2130 bool operator&&(bool, bool);
2131 bool operator||(bool, bool); */
2134 build_builtin_candidate
2141 build_builtin_candidate
2159 /* Fall through. */
2163 }
2168 {
2170 ;
2172 {
2173 tree convs;
2181 {
2188 }
2194 {
2207 {
2213 }
2217 }
2218 }
2219 else
2220 {
2226 {
2232 }
2234 }
2235 }
2237 /* Run through the possible parameter types of both arguments,
2238 creating candidates with those parameter types. */
2240 {
2243 add_builtin_candidate
2246 else
2247 add_builtin_candidate
2250 }
2251 }
2254 /* If TMPL can be successfully instantiated as indicated by
2255 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2257 TMPL is the template. EXPLICIT_TARGS are any explicit template
2258 arguments. ARGLIST is the arguments provided at the call-site.
2259 The RETURN_TYPE is the desired type for conversion operators. If
2260 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2261 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2262 add_conv_candidate. */
2269 unification_kind_t strict)
2270 {
2276 tree fn;
2278 /* We don't do deduction on the in-charge parameter, the VTT
2279 parameter or 'this'. */
2289 args_without_in_chrg,
2299 /* In [class.copy]:
2301 A member function template is never instantiated to perform the
2302 copy of a class object to an object of its class type.
2304 It's a little unclear what this means; the standard explicitly
2305 does allow a template to be used to copy a class. For example,
2306 in:
2308 struct A {
2309 A(A&);
2310 template <class T> A(const T&);
2311 };
2312 const A f ();
2313 void g () { A a (f ()); }
2315 the member template will be used to make the copy. The section
2316 quoted above appears in the paragraph that forbids constructors
2317 whose only parameter is (a possibly cv-qualified variant of) the
2318 class type, and a logical interpretation is that the intent was
2319 to forbid the instantiation of member templates which would then
2320 have that form. */
2322 {
2325 ctype))
2327 }
2330 /* Aha, this is a conversion function. */
2333 else
2338 /* This situation can occur if a member template of a template
2339 class is specialized. Then, instantiate_template might return
2340 an instantiation of the specialization, in which case the
2341 DECL_TI_TEMPLATE field will point at the original
2342 specialization. For example:
2344 template <class T> struct S { template <class U> void f(U);
2345 template <> void f(int) {}; };
2346 S<double> sd;
2347 sd.f(3);
2349 Here, TMPL will be template <class U> S<double>::f(U).
2350 And, instantiate template will give us the specialization
2351 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2352 for this will point at template <class T> template <> S<T>::f(int),
2353 so that we can find the definition. For the purposes of
2354 overload resolution, however, we want the original TMPL. */
2356 else
2360 }
2367 unification_kind_t strict)
2368 {
2369 return
2374 }
2381 {
2382 return
2386 }
2388 /* The CANDS are the set of candidates that were considered for
2389 overload resolution. Return the set of viable candidates. If none
2390 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2391 is true if a candidate should be considered viable only if it is
2392 strictly viable. */
2398 {
2409 {
2412 {
2418 }
2419 else
2421 }
2424 }
2426 static bool
2428 {
2433 }
2435 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2436 words, it is about to become the "this" pointer for a member
2437 function call. Take the address of the object. */
2439 static tree
2441 {
2442 /* In a template, we are only concerned about the type of the
2443 expression, so we can take a shortcut. */
2448 }
2450 /* Returns true iff functions are equivalent. Equivalent functions are
2451 not '==' only if one is a function-local extern function or if
2452 both are extern "C". */
2456 {
2461 }
2463 /* Print information about one overload candidate CANDIDATE. MSGSTR
2464 is the text to print before the candidate itself.
2466 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2467 to have been run through gettext by the caller. This wart makes
2468 life simpler in print_z_candidates and for the translators. */
2470 static void
2472 {
2474 {
2484 else
2487 }
2492 else
2494 }
2496 static void
2498 {
2503 /* There may be duplicates in the set of candidates. We put off
2504 checking this condition as long as possible, since we have no way
2505 to eliminate duplicates from a set of functions in less than n^2
2506 time. Now we are about to emit an error message, so it is more
2507 permissible to go slowly. */
2509 {
2511 /* Skip builtin candidates and conversion functions. */
2516 {
2520 else
2522 }
2523 }
2531 {
2532 /* Indent successive candidates by the width of the translation
2533 of the above string. */
2540 do
2541 {
2544 }
2546 }
2547 }
2549 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2550 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2551 the result of the conversion function to convert it to the final
2552 desired type. Merge the two sequences into a single sequence,
2553 and return the merged sequence. */
2557 {
2562 /* Find the end of the second conversion sequence. */
2567 /* Replace the identity conversion with the user conversion
2568 sequence. */
2571 /* The entire sequence is a user-conversion sequence. */
2575 }
2577 /* Returns the best overload candidate to perform the requested
2578 conversion. This function is used for three the overloading situations
2579 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2580 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2581 per [dcl.init.ref], so we ignore temporary bindings. */
2585 {
2594 /* We represent conversion within a hierarchy using RVALUE_CONV and
2595 BASE_CONV, as specified by [over.best.ics]; these become plain
2596 constructor calls, as specified in [dcl.init]. */
2610 {
2611 tree t;
2617 /* We should never try to call the abstract or base constructor
2618 from here. */
2622 }
2624 {
2634 flags,
2635 DEDUCE_CALL);
2636 else
2640 flags);
2644 }
2650 {
2651 tree fns;
2655 /* If we are called to convert to a reference type, we are trying to
2656 find an lvalue binding, so don't even consider temporaries. If
2657 we don't find an lvalue binding, the caller will try again to
2658 look for a temporary binding. */
2663 {
2666 /* [over.match.funcs] For conversion functions, the function
2667 is considered to be a member of the class of the implicit
2668 object argument for the purpose of defining the type of
2669 the implicit object parameter.
2671 So we pass fromtype as CTYPE to add_*_candidate. */
2675 NULL_TREE,
2678 conversion_path,
2679 flags,
2680 DEDUCE_CONV);
2681 else
2683 args,
2685 conversion_path,
2686 flags);
2689 {
2690 conversion *ics
2702 }
2703 }
2704 }
2712 {
2714 {
2718 }
2725 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2726 ambiguous conversion is no worse than another user-defined
2727 conversion. */
2730 }
2732 /* Build the user conversion sequence. */
2733 conv = build_conv
2740 /* Combine it with the second conversion sequence. */
2748 }
2750 tree
2752 {
2757 {
2762 }
2764 }
2766 /* Do any initial processing on the arguments to a function call. */
2768 static tree
2770 {
2771 tree t;
2773 {
2779 {
2782 }
2785 }
2787 }
2789 /* Perform overload resolution on FN, which is called with the ARGS.
2791 Return the candidate function selected by overload resolution, or
2792 NULL if the event that overload resolution failed. In the case
2793 that overload resolution fails, *CANDIDATES will be the set of
2794 candidates considered, and ANY_VIABLE_P will be set to true or
2795 false to indicate whether or not any of the candidates were
2796 viable.
2798 The ARGS should already have gone through RESOLVE_ARGS before this
2799 function is called. */
2803 tree args,
2806 {
2814 /* Check FN and ARGS. */
2822 {
2826 }
2828 /* Add the various candidate functions. */
2832 LOOKUP_NORMAL,
2833 candidates);
2841 }
2843 /* Return an expression for a call to FN (a namespace-scope function,
2844 or a static member function) with the ARGS. */
2846 tree
2848 {
2852 tree result;
2858 /* If this function was found without using argument dependent
2859 lookup, then we want to ignore any undeclared friend
2860 functions. */
2862 {
2867 {
2871 }
2872 }
2874 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2880 {
2888 else
2894 }
2895 else
2898 /* Free all the conversions we allocated. */
2902 }
2904 /* Build a call to a global operator new. FNNAME is the name of the
2905 operator (either "operator new" or "operator new[]") and ARGS are
2906 the arguments provided. *SIZE points to the total number of bytes
2907 required by the allocation, and is updated if that is changed here.
2908 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
2909 function determines that no cookie should be used, after all,
2910 *COOKIE_SIZE is set to NULL_TREE. If FN is non-NULL, it will be
2911 set, upon return, to the allocation function called. */
2913 tree
2917 {
2918 tree fns;
2930 /* Based on:
2932 [expr.new]
2934 If this lookup fails to find the name, or if the allocated type
2935 is not a class type, the allocation function's name is looked
2936 up in the global scope.
2938 we disregard block-scope declarations of "operator new". */
2941 /* Figure out what function is being called. */
2944 /* If no suitable function could be found, issue an error message
2945 and give up. */
2947 {
2951 else
2957 }
2959 /* If a cookie is required, add some extra space. Whether
2960 or not a cookie is required cannot be determined until
2961 after we know which function was called. */
2963 {
2966 {
2968 /* In G++ 3.2, the check was implemented incorrectly; it
2969 looked at the placement expression, rather than the
2970 type of the function. */
2973 ptr_type_node))
2975 }
2976 else
2977 {
2978 tree arg_types;
2981 /* Skip the size_t parameter. */
2983 /* Check the remaining parameters (if any). */
2987 ptr_type_node))
2989 }
2990 /* If we need a cookie, adjust the number of bytes allocated. */
2992 {
2993 /* Update the total size. */
2995 /* Update the argument list to reflect the adjusted size. */
2997 }
2998 else
3000 }
3002 /* Tell our caller which function we decided to call. */
3006 /* Build the CALL_EXPR. */
3008 }
3010 static tree
3012 {
3021 {
3022 /* It's no good looking for an overloaded operator() on a
3023 pointer-to-member-function. */
3024 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3026 }
3029 {
3033 }
3034 else
3042 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3046 {
3051 {
3059 else
3060 add_function_candidate
3063 }
3064 }
3069 {
3081 {
3084 add_template_conv_candidate
3088 else
3092 }
3093 }
3097 {
3101 }
3102 else
3103 {
3106 {
3110 }
3111 /* Since cand->fn will be a type, not a function, for a conversion
3112 function, we must be careful not to unconditionally look at
3113 DECL_NAME here. */
3117 else
3118 {
3122 }
3123 }
3125 /* Free all the conversions we allocated. */
3129 }
3131 static void
3134 {
3139 else
3143 {
3167 else
3171 }
3172 }
3174 /* Return the implicit conversion sequence that could be used to
3175 convert E1 to E2 in [expr.cond]. */
3179 {
3185 /* [expr.cond]
3187 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3188 implicitly converted (clause _conv_) to the type "reference to
3189 T2", subject to the constraint that in the conversion the
3190 reference must bind directly (_dcl.init.ref_) to E1. */
3192 {
3194 t1,
3195 e1,
3197 LOOKUP_NO_TEMP_BIND);
3200 }
3202 /* [expr.cond]
3204 If E1 and E2 have class type, and the underlying class types are
3205 the same or one is a base class of the other: E1 can be converted
3206 to match E2 if the class of T2 is the same type as, or a base
3207 class of, the class of T1, and the cv-qualification of T2 is the
3208 same cv-qualification as, or a greater cv-qualification than, the
3209 cv-qualification of T1. If the conversion is applied, E1 is
3210 changed to an rvalue of type T2 that still refers to the original
3211 source class object (or the appropriate subobject thereof). */
3214 {
3216 {
3221 else
3224 }
3225 else
3227 }
3228 else
3229 /* [expr.cond]
3231 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3232 converted to the type that expression E2 would have if E2 were
3233 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3235 LOOKUP_NORMAL);
3236 }
3238 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3239 arguments to the conditional expression. */
3241 tree
3243 {
3244 tree arg2_type;
3245 tree arg3_type;
3253 /* As a G++ extension, the second argument to the conditional can be
3254 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3255 c'.) If the second operand is omitted, make sure it is
3256 calculated only once. */
3258 {
3262 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3265 else
3267 }
3269 /* [expr.cond]
3271 The first expr ession is implicitly converted to bool (clause
3272 _conv_). */
3275 /* If something has already gone wrong, just pass that fact up the
3276 tree. */
3282 /* [expr.cond]
3284 If either the second or the third operand has type (possibly
3285 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3286 array-to-pointer (_conv.array_), and function-to-pointer
3287 (_conv.func_) standard conversions are performed on the second
3288 and third operands. */
3292 {
3293 /* Do the conversions. We don't these for `void' type arguments
3294 since it can't have any effect and since decay_conversion
3295 does not handle that case gracefully. */
3303 /* [expr.cond]
3305 One of the following shall hold:
3307 --The second or the third operand (but not both) is a
3308 throw-expression (_except.throw_); the result is of the
3309 type of the other and is an rvalue.
3311 --Both the second and the third operands have type void; the
3312 result is of type void and is an rvalue.
3314 We must avoid calling force_rvalue for expressions of type
3315 "void" because it will complain that their value is being
3316 used. */
3319 {
3324 }
3327 {
3332 }
3335 else
3336 {
3339 "is of type %<void%>, "
3340 "but the third operand is neither a throw-expression "
3342 else
3344 "is of type %<void%>, "
3345 "but the second operand is neither a throw-expression "
3348 }
3352 }
3353 /* [expr.cond]
3355 Otherwise, if the second and third operand have different types,
3356 and either has (possibly cv-qualified) class type, an attempt is
3357 made to convert each of those operands to the type of the other. */
3360 {
3364 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3370 /* [expr.cond]
3372 If both can be converted, or one can be converted but the
3373 conversion is ambiguous, the program is ill-formed. If
3374 neither can be converted, the operands are left unchanged and
3375 further checking is performed as described below. If exactly
3376 one conversion is possible, that conversion is applied to the
3377 chosen operand and the converted operand is used in place of
3378 the original operand for the remainder of this section. */
3383 {
3387 }
3389 {
3393 /* Even if CONV2 is a valid conversion, the result of the
3394 conversion may be invalid. For example, if ARG3 has type
3395 "volatile X", and X does not have a copy constructor
3396 accepting a "volatile X&", then even if ARG2 can be
3397 converted to X, the conversion will fail. */
3400 }
3402 {
3408 }
3410 /* Free all the conversions we allocated. */
3416 /* If, after the conversion, both operands have class type,
3417 treat the cv-qualification of both operands as if it were the
3418 union of the cv-qualification of the operands.
3420 The standard is not clear about what to do in this
3421 circumstance. For example, if the first operand has type
3422 "const X" and the second operand has a user-defined
3423 conversion to "volatile X", what is the type of the second
3424 operand after this step? Making it be "const X" (matching
3425 the first operand) seems wrong, as that discards the
3426 qualification without actually performing a copy. Leaving it
3427 as "volatile X" seems wrong as that will result in the
3428 conditional expression failing altogether, even though,
3429 according to this step, the one operand could be converted to
3430 the type of the other. */
3438 }
3440 /* [expr.cond]
3442 If the second and third operands are lvalues and have the same
3443 type, the result is of that type and is an lvalue. */
3447 {
3450 }
3452 /* [expr.cond]
3454 Otherwise, the result is an rvalue. If the second and third
3455 operand do not have the same type, and either has (possibly
3456 cv-qualified) class type, overload resolution is used to
3457 determine the conversions (if any) to be applied to the operands
3458 (_over.match.oper_, _over.built_). */
3462 {
3467 /* Rearrange the arguments so that add_builtin_candidate only has
3468 to know about two args. In build_builtin_candidates, the
3469 arguments are unscrambled. */
3474 COND_EXPR,
3475 NOP_EXPR,
3477 args,
3478 LOOKUP_NORMAL);
3480 /* [expr.cond]
3482 If the overload resolution fails, the program is
3483 ill-formed. */
3486 {
3490 }
3493 {
3497 }
3499 /* [expr.cond]
3501 Otherwise, the conversions thus determined are applied, and
3502 the converted operands are used in place of the original
3503 operands for the remainder of this section. */
3510 }
3512 /* [expr.cond]
3514 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3515 and function-to-pointer (_conv.func_) standard conversions are
3516 performed on the second and third operands.
3518 We need to force the lvalue-to-rvalue conversion here for class types,
3519 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3520 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3521 regions. */
3534 /* [expr.cond]
3536 After those conversions, one of the following shall hold:
3538 --The second and third operands have the same type; the result is of
3539 that type. */
3542 /* [expr.cond]
3544 --The second and third operands have arithmetic or enumeration
3545 type; the usual arithmetic conversions are performed to bring
3546 them to a common type, and the result is of that type. */
3551 {
3552 /* In this case, there is always a common type. */
3554 arg3_type);
3569 }
3570 /* [expr.cond]
3572 --The second and third operands have pointer type, or one has
3573 pointer type and the other is a null pointer constant; pointer
3574 conversions (_conv.ptr_) and qualification conversions
3575 (_conv.qual_) are performed to bring them to their composite
3576 pointer type (_expr.rel_). The result is of the composite
3577 pointer type.
3579 --The second and third operands have pointer to member type, or
3580 one has pointer to member type and the other is a null pointer
3581 constant; pointer to member conversions (_conv.mem_) and
3582 qualification conversions (_conv.qual_) are performed to bring
3583 them to a common type, whose cv-qualification shall match the
3584 cv-qualification of either the second or the third operand.
3585 The result is of the common type. */
3593 {
3600 }
3603 {
3607 }
3609 valid_operands:
3612 /* We can't use result_type below, as fold might have returned a
3613 throw_expr. */
3616 {
3617 /* Expand both sides into the same slot, hopefully the target of
3618 the ?: expression. We used to check for TARGET_EXPRs here,
3619 but now we sometimes wrap them in NOP_EXPRs so the test would
3620 fail. */
3623 /* If this expression is an rvalue, but might be mistaken for an
3624 lvalue, we must add a NON_LVALUE_EXPR. */
3626 }
3629 }
3631 /* OPERAND is an operand to an expression. Perform necessary steps
3632 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3633 returned. */
3635 static tree
3637 {
3639 {
3642 /* Make sure the template type is instantiated now. */
3644 }
3647 }
3649 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3650 OVERLOAD) to the CANDIDATES, returning an updated list of
3651 CANDIDATES. The ARGS are the arguments provided to the call,
3652 without any implicit object parameter. The EXPLICIT_TARGS are
3653 explicit template arguments provided. TEMPLATE_ONLY is true if
3654 only template functions should be considered. CONVERSION_PATH,
3655 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3657 static void
3663 {
3664 tree ctype;
3665 tree non_static_args;
3668 /* Delay creating the implicit this parameter until it is needed. */
3672 {
3673 tree fn;
3674 tree fn_args;
3677 /* Figure out which set of arguments to use. */
3679 {
3680 /* If this function is a non-static member, prepend the implicit
3681 object parameter. */
3687 }
3688 else
3689 /* Otherwise, just use the list of arguments provided. */
3694 fn,
3695 ctype,
3696 explicit_targs,
3697 fn_args,
3698 NULL_TREE,
3699 access_path,
3700 conversion_path,
3701 flags,
3702 DEDUCE_CALL);
3705 fn,
3706 ctype,
3707 fn_args,
3708 access_path,
3709 conversion_path,
3710 flags);
3712 }
3713 }
3715 tree
3718 {
3737 {
3741 }
3742 else
3748 {
3753 /* Use build_op_new_call and build_op_delete_call instead. */
3767 }
3773 {
3780 }
3795 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3798 /* Add namespace-scope operators to the list of functions to
3799 consider. */
3803 /* Add class-member operators to the candidate set. */
3805 {
3806 tree fns;
3810 {
3813 }
3820 }
3822 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
3823 to know about two args; a builtin candidate will always have a first
3824 parameter of type bool. We'll handle that in
3825 build_builtin_candidate. */
3827 {
3831 }
3832 else
3833 {
3837 }
3842 {
3845 /* For these, the built-in candidates set is empty
3846 [over.match.oper]/3. We don't want non-strict matches
3847 because exact matches are always possible with built-in
3848 operators. The built-in candidate set for COMPONENT_REF
3849 would be empty too, but since there are no such built-in
3850 operators, we accept non-strict matches for them. */
3857 }
3861 {
3863 {
3866 /* Look for an `operator++ (int)'. If they didn't have
3867 one, then we fall back to the old way of doing things. */
3871 fnname,
3875 else
3878 overloaded_p);
3881 /* The caller will deal with these. */
3891 {
3894 }
3897 }
3898 }
3899 else
3900 {
3903 {
3905 {
3908 }
3910 }
3912 {
3917 }
3918 else
3919 {
3920 /* Give any warnings we noticed during overload resolution. */
3922 {
3926 }
3928 /* Check for comparison of different enum types. */
3930 {
3941 {
3944 }
3948 }
3950 /* We need to strip any leading REF_BIND so that bitfields
3951 don't cause errors. This should not remove any important
3952 conversions, because builtins don't apply to class
3953 objects directly. */
3959 {
3964 }
3966 {
3971 }
3974 {
3977 }
3978 }
3979 }
3981 user_defined_result_ready:
3983 /* Free all the conversions we allocated. */
3989 builtin:
3991 {
4045 /* The caller will deal with these. */
4053 }
4055 }
4057 /* Build a call to operator delete. This has to be handled very specially,
4058 because the restrictions on what signatures match are different from all
4059 other call instances. For a normal delete, only a delete taking (void *)
4060 or (void *, size_t) is accepted. For a placement delete, only an exact
4061 match with the placement new is accepted.
4063 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4064 ADDR is the pointer to be deleted.
4065 SIZE is the size of the memory block to be deleted.
4066 GLOBAL_P is true if the delete-expression should not consider
4067 class-specific delete operators.
4068 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4070 If this call to "operator delete" is being generated as part to
4071 deallocate memory allocated via a new-expression (as per [expr.new]
4072 which requires that if the initialization throws an exception then
4073 we call a deallocation function), then ALLOC_FN is the allocation
4074 function. */
4076 tree
4079 tree alloc_fn)
4080 {
4095 /* In [class.free]
4097 If the result of the lookup is ambiguous or inaccessible, or if
4098 the lookup selects a placement deallocation function, the
4099 program is ill-formed.
4101 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4102 {
4106 }
4107 else
4113 /* Strip const and volatile from addr. */
4117 {
4118 /* Get the parameter types for the allocation function that is
4119 being called. */
4122 }
4123 else
4124 {
4125 /* First try it without the size argument. */
4127 }
4129 /* We make two tries at finding a matching `operator delete'. On
4130 the first pass, we look for a one-operator (or placement)
4131 operator delete. If we're not doing placement delete, then on
4132 the second pass we look for a two-argument delete. */
4134 {
4135 /* Go through the `operator delete' functions looking for one
4136 with a matching type. */
4138 fn;
4140 {
4141 tree t;
4143 /* The first argument must be "void *". */
4148 /* On the first pass, check the rest of the arguments. */
4150 {
4153 {
4158 }
4161 }
4162 /* On the second pass, look for a function with exactly two
4163 arguments: "void *" and "size_t". */
4165 /* For "operator delete(void *, ...)" there will be
4166 no second argument, but we will not get an exact
4167 match above. */
4168 && t
4172 }
4174 /* If we found a match, we're done. */
4177 }
4179 /* If we have a matching function, call it. */
4181 {
4182 /* Make sure we have the actual function, and not an
4183 OVERLOAD. */
4186 /* If the FN is a member function, make sure that it is
4187 accessible. */
4192 {
4193 /* The placement args might not be suitable for overload
4194 resolution at this point, so build the call directly. */
4203 }
4204 else
4205 {
4206 tree args;
4209 else
4213 }
4214 }
4216 /* [expr.new]
4218 If no unambiguous matching deallocation function can be found,
4219 propagating the exception does not cause the object's memory to
4220 be freed. */
4222 {
4225 alloc_fn);
4227 }
4232 }
4234 /* If the current scope isn't allowed to access DECL along
4235 BASETYPE_PATH, give an error. The most derived class in
4236 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4237 the declaration to use in the error diagnostic. */
4239 bool
4241 {
4245 {
4250 else
4254 }
4257 }
4259 /* Check that a callable constructor to initialize a temporary of
4260 TYPE from an EXPR exists. */
4262 static void
4264 {
4266 complete_ctor_identifier,
4268 type,
4269 LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING
4270 | LOOKUP_NO_CONVERSION
4272 }
4274 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4275 bitwise or of LOOKUP_* values. If any errors are warnings are
4276 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4277 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4278 to NULL. */
4280 static tree
4283 {
4288 complete_ctor_identifier,
4295 else
4298 }
4300 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4301 EXPR is implicitly converted to type TOTYPE.
4302 FN and ARGNUM are used for diagnostics. */
4304 static void
4306 {
4309 /* Issue warnings about peculiar, but valid, uses of NULL. */
4311 {
4315 else
4317 }
4319 /* Issue warnings if "false" is converted to a NULL pointer */
4324 }
4326 /* Perform the conversions in CONVS on the expression EXPR. FN and
4327 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4328 indicates the `this' argument of a method. INNER is nonzero when
4329 being called to continue a conversion chain. It is negative when a
4330 reference binding will be applied, positive otherwise. If
4331 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4332 conversions will be emitted if appropriate. If C_CAST_P is true,
4333 this conversion is coming from a C-style cast; in that case,
4334 conversions to inaccessible bases are permitted. */
4336 static tree
4340 {
4342 diagnostic_fn_t diagnostic_fn;
4348 {
4351 {
4353 {
4358 }
4365 }
4370 }
4376 {
4378 {
4384 /* If this is a constructor or a function returning an aggr type,
4385 we need to build up a TARGET_EXPR. */
4389 /* The result of the call is then used to direct-initialize the object
4390 that is the destination of the copy-initialization. [dcl.init]
4392 Note that this step is not reflected in the conversion sequence;
4393 it affects the semantics when we actually perform the
4394 conversion, but is not considered during overload resolution.
4396 If the target is a class, that means call a ctor. */
4399 {
4400 expr = (build_temp
4402 /* Core issue 84, now a DR, says that we don't
4403 allow UDCs for these args (which deliberately
4404 breaks copy-init of an auto_ptr<Base> from an
4405 auto_ptr<Derived>). */
4410 {
4412 diagnostic_fn
4415 else
4416 diagnostic_fn
4418 }
4420 }
4422 }
4426 /* Convert a constant to its underlying value, unless we are
4427 about to bind it to a reference, in which case we need to
4428 leave it as an lvalue. */
4435 /* Call build_user_type_conversion again for the error. */
4436 return build_user_type_conversion
4441 };
4446 c_cast_p);
4451 {
4456 /* Else fall through. */
4459 {
4460 /* We are going to bind a reference directly to a base-class
4461 subobject of EXPR. */
4464 /* Build an expression for `*((base*) &expr)'. */
4470 }
4472 /* Copy-initialization where the cv-unqualified version of the source
4473 type is the same class as, or a derived class of, the class of the
4474 destination [is treated as direct-initialization]. [dcl.init] */
4482 {
4485 /* If necessary, create a temporary.
4487 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
4488 that need temporaries, even when their types are reference
4489 compatible with the type of reference being bound, so the
4490 upcoming call to build_unary_op (ADDR_EXPR, expr, ...)
4491 doesn't fail. */
4495 {
4501 {
4502 /* If the reference is volatile or non-const, we
4503 cannot create a temporary. */
4510 else
4513 }
4514 /* If the source is a packed field, and we must use a copy
4515 constructor, then building the target expr will require
4516 binding the field to the reference parameter to the
4517 copy constructor, and we'll end up with an infinite
4518 loop. If we can use a bitwise copy, then we'll be
4519 OK. */
4523 {
4527 }
4529 }
4531 /* Take the address of the thing to which we will bind the
4532 reference. */
4537 /* Convert it to a pointer to the type referred to by the
4538 reference. This will adjust the pointer if a derived to
4539 base conversion is being performed. */
4541 expr);
4542 /* Convert the pointer to the desired reference type. */
4544 }
4550 /* Warn about deprecated conversion if appropriate. */
4562 c_cast_p);
4566 }
4570 else
4574 }
4576 /* Build a call to __builtin_trap. */
4578 static tree
4580 {
4586 }
4588 /* ARG is being passed to a varargs function. Perform any conversions
4589 required. Return the converted value. */
4591 tree
4593 {
4594 /* [expr.call]
4596 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4597 standard conversions are performed. */
4599 /* [expr.call]
4601 If the argument has integral or enumeration type that is subject
4602 to the integral promotions (_conv.prom_), or a floating point
4603 type that is subject to the floating point promotion
4604 (_conv.fpprom_), the value of the argument is converted to the
4605 promoted type before the call. */
4617 {
4618 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4619 here and do a bitwise copy, but now cp_expr_size will abort if we
4620 try to do that.
4621 If the call appears in the context of a sizeof expression,
4622 there is no need to emit a warning, since the expression won't be
4623 evaluated. We keep the builtin_trap just as a safety check. */
4629 integer_zero_node);
4630 }
4633 }
4635 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4637 tree
4639 {
4649 {
4650 /* Remove reference types so we don't ICE later on. */
4652 /* Undefined behavior [expr.call] 5.2.2/7. */
4660 }
4663 }
4665 /* TYPE has been given to va_arg. Apply the default conversions which
4666 would have happened when passed via ellipsis. Return the promoted
4667 type, or the passed type if there is no change. */
4669 tree
4671 {
4672 tree promote;
4674 /* Perform the array-to-pointer and function-to-pointer
4675 conversions. */
4683 }
4685 /* ARG is a default argument expression being passed to a parameter of
4686 the indicated TYPE, which is a parameter to FN. Do any required
4687 conversions. Return the converted value. */
4689 tree
4691 {
4692 /* If the ARG is an unparsed default argument expression, the
4693 conversion cannot be performed. */
4695 {
4700 }
4708 {
4712 }
4713 else
4714 {
4715 /* We must make a copy of ARG, in case subsequent processing
4716 alters any part of it. For example, during gimplification a
4717 cast of the form (T) &X::f (where "f" is a member function)
4718 will lead to replacing the PTRMEM_CST for &X::f with a
4719 VAR_DECL. We can avoid the copy for constants, since they
4720 are never modified in place. */
4726 }
4729 }
4731 /* Returns the type which will really be used for passing an argument of
4732 type TYPE. */
4734 tree
4736 {
4737 /* Pass classes with copy ctors by invisible reference. */
4739 {
4741 /* There are no other pointers to this temporary. */
4743 }
4752 }
4754 /* Actually perform the appropriate conversion. */
4756 tree
4758 {
4759 tree bitfield_type;
4761 /* If VAL is a bitfield, then -- since it has already been converted
4762 to TYPE -- it cannot have a precision greater than TYPE.
4764 If it has a smaller precision, we must widen it here. For
4765 example, passing "int f:3;" to a function expecting an "int" will
4766 not result in any conversion before this point.
4768 If the precision is the same we must not risk widening. For
4769 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
4770 often have type "int", even though the C++ type for the field is
4771 "long long". If the value is being passed to a function
4772 expecting an "int", then no conversions will be required. But,
4773 if we call convert_bitfield_to_declared_type, the bitfield will
4774 be converted to "long long". */
4781 ;
4782 /* Pass classes with copy ctors by invisible reference. */
4792 {
4801 }
4803 }
4805 /* Returns true iff FN is a function with magic varargs, i.e. ones for
4806 which no conversions at all should be done. This is true for some
4807 builtins which don't act like normal functions. */
4809 static bool
4811 {
4814 {
4825 }
4828 }
4830 /* Subroutine of the various build_*_call functions. Overload resolution
4831 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
4832 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
4833 bitmask of various LOOKUP_* flags which apply to the call itself. */
4835 static tree
4837 {
4851 /* In a template, there is no need to perform all of the work that
4852 is normally done. We are only interested in the type of the call
4853 expression, i.e., the return type of the function. Any semantic
4854 errors will be deferred until the template is instantiated. */
4856 {
4857 tree expr;
4858 tree return_type;
4866 }
4868 /* Give any warnings we noticed during overload resolution. */
4870 {
4874 }
4877 {
4878 /* If FN is a template function, two cases must be considered.
4879 For example:
4881 struct A {
4882 protected:
4883 template <class T> void f();
4884 };
4885 template <class T> struct B {
4886 protected:
4887 void g();
4888 };
4889 struct C : A, B<int> {
4890 using A::f; // #1
4891 using B<int>::g; // #2
4892 };
4894 In case #1 where `A::f' is a member template, DECL_ACCESS is
4895 recorded in the primary template but not in its specialization.
4896 We check access of FN using its primary template.
4898 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
4899 because it is a member of class template B, DECL_ACCESS is
4900 recorded in the specialization `B<int>::g'. We cannot use its
4901 primary template because `B<T>::g' and `B<int>::g' may have
4902 different access. */
4907 else
4909 }
4915 /* Find maximum size of vector to hold converted arguments. */
4922 /* The implicit parameters to a constructor are not considered by overload
4923 resolution, and must be of the proper type. */
4925 {
4929 /* We should never try to call the abstract constructor. */
4933 {
4937 }
4938 }
4939 /* Bypass access control for 'this' parameter. */
4941 {
4944 tree converted_arg;
4945 tree base_binfo;
4951 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
4952 X is called for an object that is not of type X, or of a type
4953 derived from X, the behavior is undefined.
4955 So we can assume that anything passed as 'this' is non-null, and
4956 optimize accordingly. */
4958 /* Convert to the base in which the function was declared. */
4964 /* Check that the base class is accessible. */
4970 /* If fn was found by a using declaration, the conversion path
4971 will be to the derived class, not the base declaring fn. We
4972 must convert from derived to base. */
4983 }
4987 {
4992 /* Don't make a copy here if build_call is going to. */
4997 val = convert_like_with_context
5002 }
5004 /* Default arguments */
5009 /* Ellipsis */
5011 {
5015 else
5018 }
5026 /* Avoid actually calling copy constructors and copy assignment operators,
5027 if possible. */
5034 {
5035 tree targ;
5038 /* Pull out the real argument, disregarding const-correctness. */
5045 {
5050 }
5051 else
5056 else
5059 /* [class.copy]: the copy constructor is implicitly defined even if
5060 the implementation elided its use. */
5064 /* If we're creating a temp and we already have one, don't create a
5065 new one. If we're not creating a temp but we get one, use
5066 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5067 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5068 temp or an INIT_EXPR otherwise. */
5070 {
5075 }
5078 {
5079 tree to = stabilize_reference
5084 }
5085 }
5089 {
5090 tree to = stabilize_reference
5097 {
5100 }
5101 else
5102 {
5103 /* We must only copy the non-tail padding parts.
5104 Use __builtin_memcpy for the bitwise copy. */
5116 }
5119 }
5124 {
5125 tree t;
5137 else
5140 }
5143 else
5147 }
5149 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5150 This function performs no overload resolution, conversion, or other
5151 high-level operations. */
5153 tree
5155 {
5156 tree fndecl;
5160 /* If this call might throw an exception, note that fact. */
5167 /* Some built-in function calls will be evaluated at compile-time in
5168 fold (). */
5181 }
5185 /* Make an expression which yields the address of the Java interface
5186 method FN. This is achieved by generating a call to libjava's
5187 _Jv_LookupInterfaceMethodIdx(). */
5189 static tree
5191 {
5197 {
5202 endlink)));
5203 java_iface_lookup_fn
5207 }
5209 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5210 This is the first entry in the vtable. */
5212 integer_zero_node);
5214 /* Get the java.lang.Class pointer for the interface being called. */
5219 {
5221 iface);
5223 }
5227 /* Determine the itable index of FN. */
5230 {
5235 i++;
5236 }
5241 java_iface_lookup_fn);
5244 }
5246 /* Returns the value to use for the in-charge parameter when making a
5247 call to a function with the indicated NAME.
5249 FIXME:Can't we find a neater way to do this mapping? */
5251 tree
5253 {
5264 /* This function should only be called with one of the names listed
5265 above. */
5268 }
5270 /* Build a call to a constructor, destructor, or an assignment
5271 operator for INSTANCE, an expression with class type. NAME
5272 indicates the special member function to call; ARGS are the
5273 arguments. BINFO indicates the base of INSTANCE that is to be
5274 passed as the `this' parameter to the member function called.
5276 FLAGS are the LOOKUP_* flags to use when processing the call.
5278 If NAME indicates a complete object constructor, INSTANCE may be
5279 NULL_TREE. In this case, the caller will call build_cplus_new to
5280 store the newly constructed object into a VAR_DECL. */
5282 tree
5285 {
5286 tree fns;
5287 /* The type of the subobject to be constructed or destroyed. */
5288 tree class_type;
5297 {
5298 /* Resolve the name. */
5303 }
5309 /* Handle the special case where INSTANCE is NULL_TREE. */
5311 {
5314 }
5315 else
5316 {
5322 /* Convert to the base class, if necessary. */
5325 {
5327 /* For constructors and destructors, either the base is
5328 non-virtual, or it is virtual but we are doing the
5329 conversion from a constructor or destructor for the
5330 complete object. In either case, we can convert
5331 statically. */
5333 else
5334 /* However, for assignment operators, we must convert
5335 dynamically if the base is virtual. */
5338 }
5339 }
5345 /* When making a call to a constructor or destructor for a subobject
5346 that uses virtual base classes, pass down a pointer to a VTT for
5347 the subobject. */
5351 {
5352 tree vtt;
5353 tree sub_vtt;
5355 /* If the current function is a complete object constructor
5356 or destructor, then we fetch the VTT directly.
5357 Otherwise, we look it up using the VTT we were given. */
5363 current_vtt_parm,
5364 vtt);
5370 }
5375 }
5377 /* Return the NAME, as a C string. The NAME indicates a function that
5378 is a member of TYPE. *FREE_P is set to true if the caller must
5379 free the memory returned.
5381 Rather than go through all of this, we should simply set the names
5382 of constructors and destructors appropriately, and dispense with
5383 ctor_identifier, dtor_identifier, etc. */
5387 {
5390 /* Assume that we will not allocate memory. */
5392 /* Constructors and destructors are special. */
5394 {
5395 pretty_name
5397 /* For a destructor, add the '~'. */
5401 {
5403 /* Remember that we need to free the memory allocated. */
5405 }
5406 }
5408 {
5411 TFF_PLAIN_IDENTIFIER),
5412 NULL);
5413 /* Remember that we need to free the memory allocated. */
5415 }
5416 else
5420 }
5422 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5423 be set, upon return, to the function called. */
5425 tree
5429 {
5433 tree access_binfo;
5434 tree optype;
5436 tree name;
5437 tree user_args;
5438 tree call;
5439 tree fn;
5440 tree class_type;
5443 tree orig_instance;
5444 tree orig_fns;
5445 tree orig_args;
5450 /* We don't know what function we're going to call, yet. */
5460 {
5463 }
5469 /* Dismantle the baselink to collect all the information we need. */
5476 {
5480 }
5491 {
5494 }
5496 /* The USER_ARGS are the arguments we will display to users if an
5497 error occurs. The USER_ARGS should not include any
5498 compiler-generated arguments. The "this" pointer hasn't been
5499 added yet. However, we must remove the VTT pointer if this is a
5500 call to a base-class constructor or destructor. */
5503 {
5504 /* Callers should explicitly indicate whether they want to construct
5505 the complete object or just the part without virtual bases. */
5507 /* Similarly for destructors. */
5509 /* Remove the VTT pointer, if present. */
5513 }
5515 /* Process the argument list. */
5522 /* It's OK to call destructors and constructors on cv-qualified objects.
5523 Therefore, convert the INSTANCE_PTR to the unqualified type, if
5524 necessary. */
5527 {
5531 }
5538 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5542 {
5544 tree this_arglist;
5546 /* We can end up here for copy-init of same or base class. */
5553 else
5557 /* A member template. */
5559 class_type,
5560 explicit_targs,
5562 access_binfo,
5563 conversion_path,
5564 flags,
5565 DEDUCE_CALL);
5568 class_type,
5569 this_arglist,
5570 access_binfo,
5571 conversion_path,
5572 flags);
5573 }
5577 {
5580 else
5581 {
5591 }
5594 }
5595 else
5596 {
5599 {
5605 user_args);
5610 }
5611 else
5612 {
5620 /* This is not an error, it is runtime undefined
5621 behavior. */
5623 "abstract virtual %q#D called from constructor"
5625 fn);
5629 {
5631 fn);
5633 }
5634 else
5635 {
5639 /* Now we know what function is being called. */
5642 /* Build the actual CALL_EXPR. */
5644 /* In an expression of the form `a->f()' where `f' turns
5645 out to be a static member function, `a' is
5646 none-the-less evaluated. */
5655 /* An explicit call of the form "x->~X()" has type
5656 "void". However, on platforms where destructors
5657 return "this" (i.e., those where
5658 targetm.cxx.cdtor_returns_this is true), such calls
5659 will appear to have a return value of pointer type
5660 to the low-level call machinery. We do not want to
5661 change the low-level machinery, since we want to be
5662 able to optimize "delete f()" on such platforms as
5663 "operator delete(~X(f()))" (rather than generating
5664 "t = f(), ~X(t), operator delete (t)"). */
5666 }
5667 }
5668 }
5671 call = (build_min_non_dep_call_list
5674 orig_args));
5676 /* Free all the conversions we allocated. */
5680 }
5682 /* Returns true iff standard conversion sequence ICS1 is a proper
5683 subsequence of ICS2. */
5685 static bool
5687 {
5688 /* We can assume that a conversion of the same code
5689 between the same types indicates a subsequence since we only get
5690 here if the types we are converting from are the same. */
5697 {
5705 /* At this point, ICS1 cannot be a proper subsequence of
5706 ICS2. We can get a USER_CONV when we are comparing the
5707 second standard conversion sequence of two user conversion
5708 sequences. */
5718 }
5719 }
5721 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
5722 be any _TYPE nodes. */
5724 bool
5726 {
5731 /* We only allow proper derivation here. The DERIVED_FROM_P macro
5732 considers every class derived from itself. */
5735 }
5737 /* We build the ICS for an implicit object parameter as a pointer
5738 conversion sequence. However, such a sequence should be compared
5739 as if it were a reference conversion sequence. If ICS is the
5740 implicit conversion sequence for an implicit object parameter,
5741 modify it accordingly. */
5743 static void
5745 {
5747 {
5748 /* [over.match.funcs]
5750 For non-static member functions, the type of the
5751 implicit object parameter is "reference to cv X"
5752 where X is the class of which the function is a
5753 member and cv is the cv-qualification on the member
5754 function declaration. */
5756 tree reference_type;
5758 /* The `this' parameter is a pointer to a class type. Make the
5759 implicit conversion talk about a reference to that same class
5760 type. */
5773 }
5774 }
5776 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
5777 and return the initial reference binding conversion. Otherwise,
5778 leave *ICS unchanged and return NULL. */
5782 {
5784 {
5790 }
5793 }
5795 /* Compare two implicit conversion sequences according to the rules set out in
5796 [over.ics.rank]. Return values:
5798 1: ics1 is better than ics2
5799 -1: ics2 is better than ics1
5800 0: ics1 and ics2 are indistinguishable */
5802 static int
5804 {
5805 tree from_type1;
5806 tree from_type2;
5807 tree to_type1;
5808 tree to_type2;
5815 /* REF_BINDING is nonzero if the result of the conversion sequence
5816 is a reference type. In that case REF_CONV is the reference
5817 binding conversion. */
5821 /* Handle implicit object parameters. */
5825 /* Handle reference parameters. */
5829 /* [over.ics.rank]
5831 When comparing the basic forms of implicit conversion sequences (as
5832 defined in _over.best.ics_)
5834 --a standard conversion sequence (_over.ics.scs_) is a better
5835 conversion sequence than a user-defined conversion sequence
5836 or an ellipsis conversion sequence, and
5838 --a user-defined conversion sequence (_over.ics.user_) is a
5839 better conversion sequence than an ellipsis conversion sequence
5840 (_over.ics.ellipsis_). */
5850 {
5851 /* XXX Isn't this an extension? */
5852 /* Both ICS are bad. We try to make a decision based on what
5853 would have happened if they'd been good. */
5861 /* We couldn't make up our minds; try to figure it out below. */
5862 }
5865 /* Both conversions are ellipsis conversions. */
5868 /* User-defined conversion sequence U1 is a better conversion sequence
5869 than another user-defined conversion sequence U2 if they contain the
5870 same user-defined conversion operator or constructor and if the sec-
5871 ond standard conversion sequence of U1 is better than the second
5872 standard conversion sequence of U2. */
5875 {
5889 /* We can just fall through here, after setting up
5890 FROM_TYPE1 and FROM_TYPE2. */
5893 }
5894 else
5895 {
5899 /* We're dealing with two standard conversion sequences.
5901 [over.ics.rank]
5903 Standard conversion sequence S1 is a better conversion
5904 sequence than standard conversion sequence S2 if
5906 --S1 is a proper subsequence of S2 (comparing the conversion
5907 sequences in the canonical form defined by _over.ics.scs_,
5908 excluding any Lvalue Transformation; the identity
5909 conversion sequence is considered to be a subsequence of
5910 any non-identity conversion sequence */
5921 }
5924 {
5929 }
5930 /* Otherwise, one sequence cannot be a subsequence of the other; they
5931 don't start with the same type. This can happen when comparing the
5932 second standard conversion sequence in two user-defined conversion
5933 sequences. */
5935 /* [over.ics.rank]
5937 Or, if not that,
5939 --the rank of S1 is better than the rank of S2 (by the rules
5940 defined below):
5942 Standard conversion sequences are ordered by their ranks: an Exact
5943 Match is a better conversion than a Promotion, which is a better
5944 conversion than a Conversion.
5946 Two conversion sequences with the same rank are indistinguishable
5947 unless one of the following rules applies:
5949 --A conversion that is not a conversion of a pointer, or pointer
5950 to member, to bool is better than another conversion that is such
5951 a conversion.
5953 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
5954 so that we do not have to check it explicitly. */
5967 {
5972 }
5973 /* The rules for pointers to members A::* are just like the rules
5974 for pointers A*, except opposite: if B is derived from A then
5975 A::* converts to B::*, not vice versa. For that reason, we
5976 switch the from_ and to_ variables here. */
5983 {
5988 }
5993 {
5994 /* This was one of the pointer or pointer-like conversions.
5996 [over.ics.rank]
5998 --If class B is derived directly or indirectly from class A,
5999 conversion of B* to A* is better than conversion of B* to
6000 void*, and conversion of A* to void* is better than
6001 conversion of B* to void*. */
6004 {
6006 deref_from_type2))
6009 deref_from_type1))
6011 }
6014 {
6016 {
6018 {
6020 deref_to_type1))
6022 }
6023 /* We know that DEREF_TO_TYPE1 is `void' here. */
6025 deref_to_type2))
6027 }
6028 }
6031 {
6032 /* [over.ics.rank]
6034 --If class B is derived directly or indirectly from class A
6035 and class C is derived directly or indirectly from B,
6037 --conversion of C* to B* is better than conversion of C* to
6038 A*,
6040 --conversion of B* to A* is better than conversion of C* to
6041 A* */
6043 {
6045 deref_to_type2))
6048 deref_to_type1))
6050 }
6052 {
6054 deref_from_type1))
6057 deref_from_type2))
6059 }
6060 }
6061 }
6064 {
6067 /* [over.ics.rank]
6069 --binding of an expression of type C to a reference of type
6070 B& is better than binding an expression of type C to a
6071 reference of type A&
6073 --conversion of C to B is better than conversion of C to A, */
6076 {
6081 }
6082 }
6085 {
6088 /* [over.ics.rank]
6090 --binding of an expression of type B to a reference of type
6091 A& is better than binding an expression of type C to a
6092 reference of type A&,
6094 --conversion of B to A is better than conversion of C to A */
6097 {
6102 }
6103 }
6105 /* [over.ics.rank]
6107 --S1 and S2 differ only in their qualification conversion and yield
6108 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6109 qualification signature of type T1 is a proper subset of the cv-
6110 qualification signature of type T2 */
6116 /* [over.ics.rank]
6118 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6119 to an implicit object parameter, and either S1 binds an lvalue reference
6120 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6121 reference to an rvalue and S2 binds an lvalue reference
6122 (C++0x draft standard, 13.3.3.2)
6124 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6125 types to which the references refer are the same type except for
6126 top-level cv-qualifiers, and the type to which the reference
6127 initialized by S2 refers is more cv-qualified than the type to
6128 which the reference initialized by S1 refers */
6131 {
6135 {
6140 }
6145 }
6147 /* Neither conversion sequence is better than the other. */
6149 }
6151 /* The source type for this standard conversion sequence. */
6153 static tree
6155 {
6157 {
6162 }
6164 }
6166 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6167 a pointer to LOSER and re-running joust to produce the warning if WINNER
6168 is actually used. */
6170 static void
6172 {
6178 }
6180 /* Compare two candidates for overloading as described in
6181 [over.match.best]. Return values:
6183 1: cand1 is better than cand2
6184 -1: cand2 is better than cand1
6185 0: cand1 and cand2 are indistinguishable */
6187 static int
6189 {
6195 /* Candidates that involve bad conversions are always worse than those
6196 that don't. */
6202 /* If we have two pseudo-candidates for conversions to the same type,
6203 or two candidates for the same function, arbitrarily pick one. */
6208 /* a viable function F1
6209 is defined to be a better function than another viable function F2 if
6210 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6211 ICSi(F2), and then */
6213 /* for some argument j, ICSj(F1) is a better conversion sequence than
6214 ICSj(F2) */
6216 /* For comparing static and non-static member functions, we ignore
6217 the implicit object parameter of the non-static function. The
6218 standard says to pretend that the static function has an object
6219 parm, but that won't work with operator overloading. */
6222 {
6230 else
6231 {
6234 }
6235 }
6238 {
6244 {
6257 {
6264 else
6269 {
6273 }
6274 else
6276 }
6279 {
6282 }
6284 }
6285 }
6287 /* warn about confusing overload resolution for user-defined conversions,
6288 either between a constructor and a conversion op, or between two
6289 conversion ops. */
6293 {
6299 else
6302 /* We don't want to complain about `X::operator T1 ()'
6303 beating `X::operator T2 () const', when T2 is a no less
6304 cv-qualified version of T1. */
6307 {
6312 {
6315 }
6318 }
6319 else
6325 {
6333 }
6334 else
6336 }
6341 /* or, if not that,
6342 F1 is a non-template function and F2 is a template function
6343 specialization. */
6350 /* or, if not that,
6351 F1 and F2 are template functions and the function template for F1 is
6352 more specialized than the template for F2 according to the partial
6353 ordering rules. */
6356 {
6357 winner = more_specialized_fn
6360 /* [temp.func.order]: The presence of unused ellipsis and default
6361 arguments has no effect on the partial ordering of function
6362 templates. add_function_candidate() will not have
6363 counted the "this" argument for constructors. */
6367 }
6369 /* or, if not that,
6370 the context is an initialization by user-defined conversion (see
6371 _dcl.init_ and _over.match.user_) and the standard conversion
6372 sequence from the return type of F1 to the destination type (i.e.,
6373 the type of the entity being initialized) is a better conversion
6374 sequence than the standard conversion sequence from the return type
6375 of F2 to the destination type. */
6378 {
6382 }
6384 /* Check whether we can discard a builtin candidate, either because we
6385 have two identical ones or matching builtin and non-builtin candidates.
6387 (Pedantically in the latter case the builtin which matched the user
6388 function should not be added to the overload set, but we spot it here.
6390 [over.match.oper]
6391 ... the builtin candidates include ...
6392 - do not have the same parameter type list as any non-template
6393 non-member candidate. */
6397 {
6403 {
6405 /* Two built-in candidates; arbitrarily pick one. */
6408 /* cand1 is built-in; prefer cand2. */
6410 else
6411 /* cand2 is built-in; prefer cand1. */
6413 }
6414 }
6416 /* If the two functions are the same (this can happen with declarations
6417 in multiple scopes and arg-dependent lookup), arbitrarily choose one. */
6422 tweak:
6424 /* Extension: If the worst conversion for one candidate is worse than the
6425 worst conversion for the other, take the first. */
6427 {
6432 {
6437 }
6443 {
6445 {
6447 ISO C++ says that these are ambiguous, even \
6448 though the worst conversion for the first is better than \
6452 }
6453 else
6456 }
6457 }
6461 }
6463 /* Given a list of candidates for overloading, find the best one, if any.
6464 This algorithm has a worst case of O(2n) (winner is last), and a best
6465 case of O(n/2) (totally ambiguous); much better than a sorting
6466 algorithm. */
6470 {
6475 /* Walk through the list once, comparing each current champ to the next
6476 candidate, knocking out a candidate or two with each comparison. */
6479 {
6483 else
6484 {
6486 {
6491 }
6492 else
6493 {
6496 }
6499 }
6500 }
6502 /* Make sure the champ is better than all the candidates it hasn't yet
6503 been compared to. */
6506 challenger != champ
6509 {
6513 }
6516 }
6518 /* Returns nonzero if things of type FROM can be converted to TO. */
6520 bool
6522 {
6524 }
6526 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
6528 bool
6530 {
6535 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6539 flags);
6542 /* Free all the conversions we allocated. */
6546 }
6548 /* Like can_convert_arg, but allows dubious conversions as well. */
6550 bool
6552 {
6556 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6558 /* Try to perform the conversion. */
6560 LOOKUP_NORMAL);
6561 /* Free all the conversions we allocated. */
6565 }
6567 /* Convert EXPR to TYPE. Return the converted expression.
6569 Note that we allow bad conversions here because by the time we get to
6570 this point we are committed to doing the conversion. If we end up
6571 doing a bad conversion, convert_like will complain. */
6573 tree
6575 {
6582 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6587 LOOKUP_NORMAL);
6589 {
6592 }
6594 {
6595 /* In a template, we are only concerned about determining the
6596 type of non-dependent expressions, so we do not have to
6597 perform the actual conversion. */
6600 }
6601 else
6604 /* Free all the conversions we allocated. */
6608 }
6610 /* Convert EXPR to TYPE (as a direct-initialization) if that is
6611 permitted. If the conversion is valid, the converted expression is
6612 returned. Otherwise, NULL_TREE is returned, except in the case
6613 that TYPE is a class type; in that case, an error is issued. If
6614 C_CAST_P is true, then this direction initialization is taking
6615 place as part of a static_cast being attempted as part of a C-style
6616 cast. */
6618 tree
6620 tree expr,
6622 {
6628 /* [dcl.init]
6630 If the destination type is a (possibly cv-qualified) class type:
6632 -- If the initialization is direct-initialization ...,
6633 constructors are considered. ... If no constructor applies, or
6634 the overload resolution is ambiguous, the initialization is
6635 ill-formed. */
6637 {
6642 }
6644 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6648 c_cast_p,
6649 LOOKUP_NORMAL);
6652 else
6655 c_cast_p);
6657 /* Free all the conversions we allocated. */
6661 }
6663 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
6664 is being bound to a temporary. Create and return a new VAR_DECL
6665 with the indicated TYPE; this variable will store the value to
6666 which the reference is bound. */
6668 tree
6670 {
6671 tree var;
6673 /* Create the variable. */
6676 /* Register the variable. */
6678 {
6679 /* Namespace-scope or local static; give it a mangled name. */
6680 tree name;
6687 }
6688 else
6689 /* Create a new cleanup level if necessary. */
6693 }
6695 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
6696 initializing a variable of that TYPE. If DECL is non-NULL, it is
6697 the VAR_DECL being initialized with the EXPR. (In that case, the
6698 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
6699 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
6700 return, if *CLEANUP is no longer NULL, it will be an expression
6701 that should be pushed as a cleanup after the returned expression
6702 is used to initialize DECL.
6704 Return the converted expression. */
6706 tree
6708 {
6715 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6719 LOOKUP_NORMAL);
6721 {
6727 else
6732 }
6734 /* If DECL is non-NULL, then this special rule applies:
6736 [class.temporary]
6738 The temporary to which the reference is bound or the temporary
6739 that is the complete object to which the reference is bound
6740 persists for the lifetime of the reference.
6742 The temporaries created during the evaluation of the expression
6743 initializing the reference, except the temporary to which the
6744 reference is bound, are destroyed at the end of the
6745 full-expression in which they are created.
6747 In that case, we store the converted expression into a new
6748 VAR_DECL in a new scope.
6750 However, we want to be careful not to create temporaries when
6751 they are not required. For example, given:
6753 struct B {};
6754 struct D : public B {};
6755 D f();
6756 const B& b = f();
6758 there is no need to copy the return value from "f"; we can just
6759 extend its lifetime. Similarly, given:
6761 struct S {};
6762 struct T { operator S(); };
6763 T t;
6764 const S& s = t;
6766 we can extend the lifetime of the return value of the conversion
6767 operator. */
6770 {
6771 tree var;
6772 tree base_conv_type;
6774 /* Skip over the REF_BIND. */
6776 /* If the next conversion is a BASE_CONV, skip that too -- but
6777 remember that the conversion was required. */
6779 {
6784 }
6785 else
6787 /* Perform the remainder of the conversion. */
6795 else
6796 {
6798 {
6799 tree init;
6800 tree type;
6802 /* Create the temporary variable. */
6806 /* If the rvalue is the result of a function call it will be
6807 a TARGET_EXPR. If it is some other construct (such as a
6808 member access expression where the underlying object is
6809 itself the result of a function call), turn it into a
6810 TARGET_EXPR here. It is important that EXPR be a
6811 TARGET_EXPR below since otherwise the INIT_EXPR will
6812 attempt to make a bitwise copy of EXPR to initialize
6813 VAR. */
6816 /* Create the INIT_EXPR that will initialize the temporary
6817 variable. */
6820 {
6824 /* We must be careful to destroy the temporary only
6825 after its initialization has taken place. If the
6826 initialization throws an exception, then the
6827 destructor should not be run. We cannot simply
6828 transform INIT into something like:
6830 (INIT, ({ CLEANUP_STMT; }))
6832 because emit_local_var always treats the
6833 initializer as a full-expression. Thus, the
6834 destructor would run too early; it would run at the
6835 end of initializing the reference variable, rather
6836 than at the end of the block enclosing the
6837 reference variable.
6839 The solution is to pass back a cleanup expression
6840 which the caller is responsible for attaching to
6841 the statement tree. */
6842 }
6843 else
6844 {
6848 static_aggregates);
6849 }
6850 /* Use its address to initialize the reference variable. */
6858 }
6859 else
6860 /* Take the address of EXPR. */
6862 /* If a BASE_CONV was required, perform it now. */
6864 expr = (perform_implicit_conversion
6867 }
6868 }
6869 else
6870 /* Perform the conversion. */
6873 /* Free all the conversions we allocated. */
6877 }