| blob | 6f401567c2e198674204e0d265ed67a57f3e45f2 |
1 /* Functions related to invoking -*- C++ -*- methods and overloaded functions.
2 Copyright (C) 1987-2018 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com) and
4 modified by Brendan Kehoe (brendan@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
23 /* High-level class interface. */
46 /* The various kinds of conversion. */
49 ck_identity,
50 ck_lvalue,
51 ck_fnptr,
52 ck_qual,
53 ck_std,
54 ck_ptr,
55 ck_pmem,
56 ck_base,
57 ck_ref_bind,
58 ck_user,
59 ck_ambig,
60 ck_list,
61 ck_aggr,
62 ck_rvalue
63 };
65 /* The rank of the conversion. Order of the enumerals matters; better
66 conversions should come earlier in the list. */
69 cr_identity,
70 cr_exact,
71 cr_promotion,
72 cr_std,
73 cr_pbool,
74 cr_user,
75 cr_ellipsis,
76 cr_bad
77 };
79 /* An implicit conversion sequence, in the sense of [over.best.ics].
80 The first conversion to be performed is at the end of the chain.
81 That conversion is always a cr_identity conversion. */
84 /* The kind of conversion represented by this step. */
85 conversion_kind kind;
86 /* The rank of this conversion. */
87 conversion_rank rank;
91 /* True if this conversion would be permitted with a bending of
92 language standards, e.g. disregarding pointer qualifiers or
93 converting integers to pointers. */
95 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
96 temporary should be created to hold the result of the
97 conversion. If KIND is ck_ambig, true if the context is
98 copy-initialization. */
100 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
101 from a pointer-to-derived to pointer-to-base is being performed. */
103 /* If KIND is ck_ref_bind, true when either an lvalue reference is
104 being bound to an lvalue expression or an rvalue reference is
105 being bound to an rvalue expression. If KIND is ck_rvalue or ck_base,
106 true when we are treating an lvalue as an rvalue (12.8p33). If
107 ck_identity, we will be binding a reference directly or decaying to
108 a pointer. */
111 /* Whether check_narrowing should only check TREE_CONSTANTs; used
112 in build_converted_constant_expr. */
114 /* The type of the expression resulting from the conversion. */
115 tree type;
117 /* The next conversion in the chain. Since the conversions are
118 arranged from outermost to innermost, the NEXT conversion will
119 actually be performed before this conversion. This variant is
120 used only when KIND is neither ck_identity, ck_ambig nor
121 ck_list. Please use the next_conversion function instead
122 of using this field directly. */
124 /* The expression at the beginning of the conversion chain. This
125 variant is used only if KIND is ck_identity or ck_ambig. */
126 tree expr;
127 /* The array of conversions for an initializer_list, so this
128 variant is used only when KIN D is ck_list. */
131 /* The function candidate corresponding to this conversion
132 sequence. This field is only used if KIND is ck_user. */
134 };
136 #define CONVERSION_RANK(NODE) \
137 ((NODE)->bad_p ? cr_bad \
138 : (NODE)->ellipsis_p ? cr_ellipsis \
139 : (NODE)->user_conv_p ? cr_user \
140 : (NODE)->rank)
142 #define BAD_CONVERSION_RANK(NODE) \
143 ((NODE)->ellipsis_p ? cr_ellipsis \
144 : (NODE)->user_conv_p ? cr_user \
145 : (NODE)->rank)
154 tsubst_flags_t);
159 #define convert_like(CONV, EXPR, COMPLAIN) \
160 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, \
163 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
164 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), \
172 tsubst_flags_t);
184 static void add_builtin_candidates
187 static void add_builtin_candidate
191 static void build_builtin_candidate
201 tsubst_flags_t);
203 tsubst_flags_t);
223 tsubst_flags_t);
227 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
228 NAME can take many forms... */
230 bool
232 {
233 /* Just accept something we've already complained about. */
242 {
247 else
249 }
250 else
251 {
252 /* In the case of:
254 template <class T> struct S { ~S(); };
255 int i;
256 i.~S();
258 NAME will be a class template. */
261 }
266 }
268 /* We want the address of a function or method. We avoid creating a
269 pointer-to-member function. */
271 tree
273 {
276 /* We have to do these by hand to avoid real pointer to member
277 functions. */
279 {
281 {
285 complain);
286 }
288 }
289 else
293 }
295 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
296 POINTER_TYPE to those. Note, pointer to member function types
297 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
298 two variants. build_call_a is the primitive taking an array of
299 arguments, while build_call_n is a wrapper that handles varargs. */
301 tree
303 {
306 else
307 {
317 }
318 }
320 /* Update various flags in cfun and the call itself based on what is being
321 called. Split out of build_call_a so that bot_manip can use it too. */
323 void
325 {
326 /* Handle both CALL_EXPRs and AGGR_INIT_EXPRs. */
329 /* We check both the decl and the type; a function may be known not to
330 throw without being declared throw(). */
346 }
348 tree
350 {
351 tree decl;
352 tree result_type;
353 tree fntype;
363 /* An rvalue has no cv-qualifiers. */
374 {
375 /* We invoke build_call directly for several library
376 functions. These may have been declared normally if
377 we're building libgcc, so we can't just check
378 DECL_ARTIFICIAL. */
383 }
389 /* Don't pass empty class objects by value. This is useful
390 for tags in STL, which are used to control overload resolution.
391 We don't need to handle other cases of copying empty classes. */
394 {
398 {
402 }
403 }
406 }
408 /* New overloading code. */
415 };
417 /* Information for providing diagnostics about why overloading failed. */
420 rr_none,
421 rr_arity,
422 rr_explicit_conversion,
423 rr_template_conversion,
424 rr_arg_conversion,
425 rr_bad_arg_conversion,
426 rr_template_unification,
427 rr_invalid_copy,
428 rr_inherited_ctor,
429 rr_constraint_failure
430 };
433 /* The index of the argument, 0-based. */
435 /* The actual argument or its type. */
436 tree from;
437 /* The type of the parameter. */
438 tree to_type;
439 /* The location of the argument. */
440 location_t loc;
441 };
446 /* Information about an arity mismatch. */
448 /* The expected number of arguments. */
450 /* The actual number of arguments in the call. */
452 /* Whether the call was a varargs call. */
455 /* Information about an argument conversion mismatch. */
457 /* Same, but for bad argument conversions. */
459 /* Information about template unification failures. These are the
460 parameters passed to fn_type_unification. */
462 tree tmpl;
463 tree explicit_targs;
467 tree return_type;
468 unification_kind_t strict;
471 /* Information about template instantiation failures. These are the
472 parameters passed to instantiate_template. */
474 tree tmpl;
475 tree targs;
478 };
481 /* The FUNCTION_DECL that will be called if this candidate is
482 selected by overload resolution. */
483 tree fn;
484 /* If not NULL_TREE, the first argument to use when calling this
485 function. */
486 tree first_arg;
487 /* The rest of the arguments to use when calling this function. If
488 there are no further arguments this may be NULL or it may be an
489 empty vector. */
491 /* The implicit conversion sequences for each of the arguments to
492 FN. */
494 /* The number of implicit conversion sequences. */
496 /* If FN is a user-defined conversion, the standard conversion
497 sequence from the type returned by FN to the desired destination
498 type. */
501 /* If FN is a member function, the binfo indicating the path used to
502 qualify the name of FN at the call site. This path is used to
503 determine whether or not FN is accessible if it is selected by
504 overload resolution. The DECL_CONTEXT of FN will always be a
505 (possibly improper) base of this binfo. */
506 tree access_path;
507 /* If FN is a non-static member function, the binfo indicating the
508 subobject to which the `this' pointer should be converted if FN
509 is selected by overload resolution. The type pointed to by
510 the `this' pointer must correspond to the most derived class
511 indicated by the CONVERSION_PATH. */
512 tree conversion_path;
513 tree template_decl;
514 tree explicit_targs;
519 /* The flags active in add_candidate. */
521 };
523 /* Returns true iff T is a null pointer constant in the sense of
524 [conv.ptr]. */
526 bool
528 {
531 /* [conv.ptr]
533 A null pointer constant is an integral constant expression
534 (_expr.const_) rvalue of integer type that evaluates to zero or
535 an rvalue of type std::nullptr_t. */
540 {
543 /* Core issue 903 says only literal 0 is a null pointer constant. */
550 }
552 {
557 }
560 }
562 /* Returns true iff T is a null member pointer value (4.11). */
564 bool
566 {
575 else
577 }
579 /* Returns nonzero if PARMLIST consists of only default parms,
580 ellipsis, and/or undeduced parameter packs. */
582 bool
584 {
591 }
593 /* Allocate N bytes of memory from the conversion obstack. The memory
594 is zeroed before being returned. */
598 {
601 {
604 }
608 }
610 /* Allocate rejection reasons. */
614 {
619 }
623 {
629 }
633 location_t loc)
634 {
642 }
646 location_t loc)
647 {
655 }
659 {
666 }
670 {
677 }
684 {
691 /* Copy args to our own storage. */
699 }
703 {
705 }
709 {
712 }
716 {
719 }
721 // Build a constraint failure record, saving information into the
722 // template_instantiation field of the rejection. If FN is not a template
723 // declaration, the TMPL member is the FN declaration and TARGS is empty.
727 {
730 {
733 }
734 else
735 {
738 }
740 }
742 /* Dynamically allocate a conversion. */
746 {
751 }
753 /* Make sure that all memory on the conversion obstack has been
754 freed. */
756 void
758 {
762 }
764 /* Dynamically allocate an array of N conversions. */
768 {
770 }
774 {
778 /* Note that the caller is responsible for filling in t->cand for
779 user-defined conversions. */
785 {
802 }
808 }
810 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
811 specialization of std::initializer_list<T>, if such a conversion is
812 possible. */
816 {
822 tree val;
824 /* Within a list-initialization we can have more user-defined
825 conversions. */
827 /* But no narrowing conversions. */
830 /* Can't make an array of these types. */
837 {
838 conversion *sub
845 }
853 {
861 }
864 }
866 /* Return the next conversion of the conversion chain (if applicable),
867 or NULL otherwise. Please use this function instead of directly
868 accessing fields of struct conversion. */
872 {
879 }
881 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list,
882 is a valid aggregate initializer for array type ATYPE. */
884 static bool
886 {
890 {
896 else
898 complain);
901 }
903 }
905 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
906 aggregate class, if such a conversion is possible. */
910 {
916 /* We already called reshape_init in implicit_conversion. */
918 /* The conversions within the init-list aren't affected by the enclosing
919 context; they're always simple copy-initialization. */
923 {
925 tree val;
933 /* Value-initialization of reference is ill-formed. */
935 else
936 {
940 }
946 else
948 complain);
955 }
967 }
969 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
970 array type, if such a conversion is possible. */
974 {
979 tree val;
984 /* We might need to propagate the size from the element to the array. */
989 {
993 }
998 {
999 conversion *sub
1011 }
1020 }
1022 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
1023 complex type, if such a conversion is possible. */
1027 tsubst_flags_t complain)
1028 {
1033 tree val;
1044 {
1045 conversion *sub
1057 }
1066 }
1068 /* Build a representation of the identity conversion from EXPR to
1069 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
1073 {
1081 }
1083 /* Converting from EXPR to TYPE was ambiguous in the sense that there
1084 were multiple user-defined conversions to accomplish the job.
1085 Build a conversion that indicates that ambiguity. */
1089 {
1097 }
1099 tree
1101 {
1105 }
1107 /* Returns the standard conversion path (see [conv]) from type FROM to type
1108 TO, if any. For proper handling of null pointer constants, you must
1109 also pass the expression EXPR to convert from. If C_CAST_P is true,
1110 this conversion is coming from a C-style cast. */
1115 {
1119 tree qualified_to;
1123 {
1126 }
1132 {
1134 {
1140 }
1142 {
1143 /* Necessary for eg, TEMPLATE_ID_EXPRs (c++/50961). */
1146 }
1147 }
1154 {
1157 /* Tell convert_like_real that we're using the address. */
1160 }
1161 /* Wrapping a ck_rvalue around a class prvalue (as a result of using
1162 obvalue_p) seems odd, since it's already a prvalue, but that's how we
1163 express the copy constructor call required by copy-initialization. */
1165 {
1167 {
1168 tree bitfield_type;
1171 {
1174 }
1175 }
1178 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */
1180 }
1182 /* Allow conversion between `__complex__' data types. */
1184 {
1185 /* The standard conversion sequence to convert FROM to TO is
1186 the standard conversion sequence to perform componentwise
1187 conversion. */
1190 complain);
1193 {
1196 }
1197 else
1201 }
1204 {
1208 }
1210 /* [conv.ptr]
1211 A null pointer constant can be converted to a pointer type; ... A
1212 null pointer constant of integral type can be converted to an
1213 rvalue of type std::nullptr_t. */
1221 {
1222 /* For backwards brain damage compatibility, allow interconversion of
1223 pointers and integers with a pedwarn. */
1226 }
1228 {
1229 /* For backwards brain damage compatibility, allow interconversion of
1230 enums and integers with a pedwarn. */
1233 }
1236 {
1237 tree to_pointee;
1238 tree from_pointee;
1241 {
1245 /* Since this is the target of a pointer, it can't have function
1246 qualifiers, so any TYPE_QUALS must be for attributes const or
1247 noreturn. Strip them. */
1254 }
1255 else
1256 {
1259 }
1263 to_pointee))
1264 ;
1268 {
1270 /* Don't try to apply restrict to void. */
1275 }
1277 {
1284 && (same_type_ignoring_top_level_qualifiers_p
1286 {
1289 }
1290 else
1292 }
1295 /* [conv.ptr]
1297 An rvalue of type "pointer to cv D," where D is a
1298 class type, can be converted to an rvalue of type
1299 "pointer to cv B," where B is a base class (clause
1300 _class.derived_) of D. If B is an inaccessible
1301 (clause _class.access_) or ambiguous
1302 (_class.member.lookup_) base class of D, a program
1303 that necessitates this conversion is ill-formed.
1304 Therefore, we use DERIVED_FROM_P, and do not check
1305 access or uniqueness. */
1307 {
1308 from_pointee
1314 }
1319 /* In a C-style cast, we ignore CV-qualification because we
1320 are allowed to perform a static_cast followed by a
1321 const_cast. */
1326 /* converting from string constant to char *. */
1330 /* Allow conversions among compatible ObjC pointer types (base
1331 conversions have been already handled above). */
1336 {
1339 }
1340 else
1344 }
1346 {
1360 else
1364 {
1366 tbase,
1372 }
1375 }
1377 {
1378 /* [conv.bool]
1380 A prvalue of arithmetic, unscoped enumeration, pointer, or pointer
1381 to member type can be converted to a prvalue of type bool. ...
1382 For direct-initialization (8.5 [dcl.init]), a prvalue of type
1383 std::nullptr_t can be converted to a prvalue of type bool; */
1389 {
1402 }
1405 }
1406 /* We don't check for ENUMERAL_TYPE here because there are no standard
1407 conversions to enum type. */
1408 /* As an extension, allow conversion to complex type. */
1410 {
1417 /* Give this a better rank if it's a promotion. */
1421 }
1427 {
1431 /* The derived-to-base conversion indicates the initialization
1432 of a parameter with base type from an object of a derived
1433 type. A temporary object is created to hold the result of
1434 the conversion unless we're binding directly to a reference. */
1437 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */
1439 }
1440 else
1447 }
1449 /* Returns nonzero if T1 is reference-related to T2. */
1451 bool
1453 {
1460 /* [dcl.init.ref]
1462 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
1463 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
1464 of T2. */
1468 }
1470 /* Returns nonzero if T1 is reference-compatible with T2. */
1472 static bool
1474 {
1475 /* [dcl.init.ref]
1477 "cv1 T1" is reference compatible with "cv2 T2" if
1478 * T1 is reference-related to T2 or
1479 * T2 is "noexcept function" and T1 is "function", where the
1480 function types are otherwise the same,
1481 and cv1 is the same cv-qualification as, or greater cv-qualification
1482 than, cv2. */
1486 }
1488 /* A reference of the indicated TYPE is being bound directly to the
1489 expression represented by the implicit conversion sequence CONV.
1490 Return a conversion sequence for this binding. */
1494 {
1495 tree t;
1503 /* Mark the identity conv as to not decay to rvalue. */
1506 /* [over.ics.rank]
1508 When a parameter of reference type binds directly
1509 (_dcl.init.ref_) to an argument expression, the implicit
1510 conversion sequence is the identity conversion, unless the
1511 argument expression has a type that is a derived class of the
1512 parameter type, in which case the implicit conversion sequence is
1513 a derived-to-base Conversion.
1515 If the parameter binds directly to the result of applying a
1516 conversion function to the argument expression, the implicit
1517 conversion sequence is a user-defined conversion sequence
1518 (_over.ics.user_), with the second standard conversion sequence
1519 either an identity conversion or, if the conversion function
1520 returns an entity of a type that is a derived class of the
1521 parameter type, a derived-to-base conversion. */
1523 {
1524 /* Represent the derived-to-base conversion. */
1526 /* We will actually be binding to the base-class subobject in
1527 the derived class, so we mark this conversion appropriately.
1528 That way, convert_like knows not to generate a temporary. */
1530 }
1533 }
1535 /* Returns the conversion path from type FROM to reference type TO for
1536 purposes of reference binding. For lvalue binding, either pass a
1537 reference type to FROM or an lvalue expression to EXPR. If the
1538 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1539 the conversion returned. If C_CAST_P is true, this
1540 conversion is coming from a C-style cast. */
1544 tsubst_flags_t complain)
1545 {
1549 tree tfrom;
1552 cp_lvalue_kind gl_kind;
1556 {
1561 }
1564 {
1566 /* DR 1288: Otherwise, if the initializer list has a single element
1567 of type E and ... [T's] referenced type is reference-related to E,
1568 the object or reference is initialized from that element... */
1570 {
1576 {
1580 }
1581 }
1582 /* Otherwise, if T is a reference type, a prvalue temporary of the type
1583 referenced by T is copy-list-initialized, and the reference is bound
1584 to that temporary. */
1586 skip:;
1587 }
1590 {
1595 else
1597 }
1603 else
1606 /* Don't allow a class prvalue when LOOKUP_NO_TEMP_BIND. */
1611 /* Same mask as real_lvalue_p. */
1618 /* Figure out whether or not the types are reference-related and
1619 reference compatible. We have to do this after stripping
1620 references from FROM. */
1622 /* If this is a C cast, first convert to an appropriately qualified
1623 type, so that we can later do a const_cast to the desired type. */
1629 /* Directly bind reference when target expression's type is compatible with
1630 the reference and expression is an lvalue. In DR391, the wording in
1631 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1632 const and rvalue references to rvalues of compatible class type.
1633 We should also do direct bindings for non-class xvalues. */
1635 {
1636 /* [dcl.init.ref]
1638 If the initializer expression
1640 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1641 is reference-compatible with "cv2 T2,"
1643 the reference is bound directly to the initializer expression
1644 lvalue.
1646 [...]
1647 If the initializer expression is an rvalue, with T2 a class type,
1648 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1649 is bound to the object represented by the rvalue or to a sub-object
1650 within that object. */
1656 /* Handle rvalue reference to function properly. */
1657 conv->rvaluedness_matches_p
1659 else
1660 conv->rvaluedness_matches_p
1665 /* For the purposes of overload resolution, we ignore the fact
1666 this expression is a bitfield or packed field. (In particular,
1667 [over.ics.ref] says specifically that a function with a
1668 non-const reference parameter is viable even if the
1669 argument is a bitfield.)
1671 However, when we actually call the function we must create
1672 a temporary to which to bind the reference. If the
1673 reference is volatile, or isn't const, then we cannot make
1674 a temporary, so we just issue an error when the conversion
1675 actually occurs. */
1678 /* Don't allow binding of lvalues (other than function lvalues) to
1679 rvalue references. */
1684 /* Nor the reverse. */
1695 }
1696 /* [class.conv.fct] A conversion function is never used to convert a
1697 (possibly cv-qualified) object to the (possibly cv-qualified) same
1698 object type (or a reference to it), to a (possibly cv-qualified) base
1699 class of that type (or a reference to it).... */
1702 {
1703 /* [dcl.init.ref]
1705 If the initializer expression
1707 -- has a class type (i.e., T2 is a class type) can be
1708 implicitly converted to an lvalue of type "cv3 T3," where
1709 "cv1 T1" is reference-compatible with "cv3 T3". (this
1710 conversion is selected by enumerating the applicable
1711 conversion functions (_over.match.ref_) and choosing the
1712 best one through overload resolution. (_over.match_).
1714 the reference is bound to the lvalue result of the conversion
1715 in the second case. */
1717 complain);
1720 }
1722 /* From this point on, we conceptually need temporaries, even if we
1723 elide them. Only the cases above are "direct bindings". */
1727 /* [over.ics.rank]
1729 When a parameter of reference type is not bound directly to an
1730 argument expression, the conversion sequence is the one required
1731 to convert the argument expression to the underlying type of the
1732 reference according to _over.best.ics_. Conceptually, this
1733 conversion sequence corresponds to copy-initializing a temporary
1734 of the underlying type with the argument expression. Any
1735 difference in top-level cv-qualification is subsumed by the
1736 initialization itself and does not constitute a conversion. */
1738 /* [dcl.init.ref]
1740 Otherwise, the reference shall be an lvalue reference to a
1741 non-volatile const type, or the reference shall be an rvalue
1742 reference.
1744 We try below to treat this as a bad conversion to improve diagnostics,
1745 but if TO is an incomplete class, we need to reject this conversion
1746 now to avoid unnecessary instantiation. */
1751 /* We're generating a temporary now, but don't bind any more in the
1752 conversion (specifically, don't slice the temporary returned by a
1753 conversion operator). */
1756 /* Core issue 899: When [copy-]initializing a temporary to be bound
1757 to the first parameter of a copy constructor (12.8) called with
1758 a single argument in the context of direct-initialization,
1759 explicit conversion functions are also considered.
1761 So don't set LOOKUP_ONLYCONVERTING in that case. */
1772 {
1773 /* If initializing the temporary used a conversion function,
1774 recalculate the second conversion sequence. */
1778 {
1781 conversion *new_second
1787 }
1788 }
1791 /* This reference binding, unlike those above, requires the
1792 creation of a temporary. */
1796 /* [dcl.init.ref]
1798 Otherwise, the reference shall be an lvalue reference to a
1799 non-volatile const type, or the reference shall be an rvalue
1800 reference. */
1804 /* [dcl.init.ref]
1806 Otherwise, a temporary of type "cv1 T1" is created and
1807 initialized from the initializer expression using the rules for a
1808 non-reference copy initialization. If T1 is reference-related to
1809 T2, cv1 must be the same cv-qualification as, or greater
1810 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1815 }
1817 /* Returns the implicit conversion sequence (see [over.ics]) from type
1818 FROM to type TO. The optional expression EXPR may affect the
1819 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1820 true, this conversion is coming from a C-style cast. */
1825 {
1832 /* Other flags only apply to the primary function in overload
1833 resolution, or after we've chosen one. */
1838 /* FIXME: actually we don't want warnings either, but we can't just
1839 have 'complain &= ~(tf_warning|tf_error)' because it would cause
1840 the regression of, eg, g++.old-deja/g++.benjamin/16077.C.
1841 We really ought not to issue that warning until we've committed
1842 to that conversion. */
1845 /* Call reshape_init early to remove redundant braces. */
1850 {
1855 }
1859 else
1866 {
1870 /* As an extension, allow list-initialization of _Complex. */
1872 {
1876 }
1878 /* Allow conversion from an initializer-list with one element to a
1879 scalar type. */
1881 {
1883 tree elt;
1889 else
1895 {
1898 /* Too many levels of braces, i.e. '{{1}}'. */
1901 }
1902 }
1905 }
1911 {
1921 {
1925 {
1926 /* "If C is not an initializer-list constructor and the
1927 initializer list has a single element of type cv U, where U is
1928 X or a class derived from X, the implicit conversion sequence
1929 has Exact Match rank if U is X, or Conversion rank if U is
1930 derived from X." */
1936 }
1938 }
1940 /* We used to try to bind a reference to a temporary here, but that
1941 is now handled after the recursive call to this function at the end
1942 of reference_binding. */
1944 }
1947 }
1949 /* Like implicit_conversion, but return NULL if the conversion is bad.
1951 This is not static so that check_non_deducible_conversion can call it within
1952 add_template_candidate_real as part of overload resolution; it should not be
1953 called outside of overload resolution. */
1955 conversion *
1958 {
1964 }
1966 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1967 functions. ARGS will not be changed until a single candidate is
1968 selected. */
1977 {
1995 }
1997 /* Return the number of remaining arguments in the parameter list
1998 beginning with ARG. */
2000 int
2002 {
2007 n++;
2010 }
2012 /* [over.match.copy]: When initializing a temporary object (12.2) to be bound
2013 to the first parameter of a constructor where the parameter is of type
2014 "reference to possibly cv-qualified T" and the constructor is called with a
2015 single argument in the context of direct-initialization of an object of type
2016 "cv2 T", explicit conversion functions are also considered.
2018 So set LOOKUP_COPY_PARM to let reference_binding know that
2019 it's being called in that context. */
2021 int
2023 {
2025 tree t;
2028 && (same_type_ignoring_top_level_qualifiers_p
2030 {
2036 }
2037 else
2041 }
2043 /* Create an overload candidate for the function or method FN called
2044 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
2045 FLAGS is passed on to implicit_conversion.
2047 This does not change ARGS.
2049 CTYPE, if non-NULL, is the type we want to pretend this function
2050 comes from for purposes of overload resolution. */
2058 tsubst_flags_t complain)
2059 {
2062 tree parmnode;
2068 /* At this point we should not see any functions which haven't been
2069 explicitly declared, except for friend functions which will have
2070 been found using argument dependent lookup. */
2073 /* The `this', `in_chrg' and VTT arguments to constructors are not
2074 considered in overload resolution. */
2076 {
2078 /* Bring back parameters omitted from an inherited ctor. */
2080 else
2084 {
2087 }
2088 }
2089 else
2096 /* 13.3.2 - Viable functions [over.match.viable]
2097 First, to be a viable function, a candidate function shall have enough
2098 parameters to agree in number with the arguments in the list.
2100 We need to check this first; otherwise, checking the ICSes might cause
2101 us to produce an ill-formed template instantiation. */
2105 {
2109 }
2113 {
2117 }
2119 /* An inherited constructor (12.6.3 [class.inhctor.init]) that has a first
2120 parameter of type "reference to cv C" (including such a constructor
2121 instantiated from a template) is excluded from the set of candidate
2122 functions when used to construct an object of type D with an argument list
2123 containing a single argument if C is reference-related to D. */
2125 && flag_new_inheriting_ctors
2127 {
2133 {
2136 }
2137 }
2139 /* Second, for a function to be viable, its constraints must be
2140 satisfied. */
2143 {
2146 }
2148 /* When looking for a function from a subobject from an implicit
2149 copy/move constructor/operator=, don't consider anything that takes (a
2150 reference to) an unrelated type. See c++/44909 and core 1092. */
2152 {
2158 else
2161 {
2164 ctype))
2166 }
2168 /* This only applies at the top level. */
2170 }
2175 /* Third, for F to be a viable function, there shall exist for each
2176 argument an implicit conversion sequence that converts that argument
2177 to the corresponding parameter of F. */
2182 {
2184 tree arg;
2192 {
2193 /* Already set during deduction. */
2196 }
2200 else
2209 {
2214 /* The type of the implicit object parameter ('this') for
2215 overload resolution is not always the same as for the
2216 function itself; conversion functions are considered to
2217 be members of the class being converted, and functions
2218 introduced by a using-declaration are considered to be
2219 members of the class that uses them.
2221 Since build_over_call ignores the ICS for the `this'
2222 parameter, we can just change the parm type. */
2224 {
2225 parmtype = cp_build_qualified_type
2228 {
2229 /* If the function has a ref-qualifier, the implicit
2230 object parameter has reference type. */
2233 /* The special handling of 'this' conversions in compare_ics
2234 does not apply if there is a ref-qualifier. */
2236 }
2237 else
2238 {
2240 /* We don't use build_this here because we don't want to
2241 capture the object argument until we've chosen a
2242 non-static member function. */
2245 }
2246 }
2253 }
2254 else
2255 {
2259 }
2266 {
2271 }
2274 {
2279 }
2280 }
2282 out:
2285 }
2287 /* Create an overload candidate for the conversion function FN which will
2288 be invoked for expression OBJ, producing a pointer-to-function which
2289 will in turn be called with the argument list FIRST_ARG/ARGLIST,
2290 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
2291 passed on to implicit_conversion.
2293 Actually, we don't really care about FN; we care about the type it
2294 converts to. There may be multiple conversion functions that will
2295 convert to that type, and we rely on build_user_type_conversion_1 to
2296 choose the best one; so when we create our candidate, we record the type
2297 instead of the function. */
2303 tsubst_flags_t complain)
2304 {
2322 /* Don't bother looking up the same type twice. */
2327 {
2333 else
2338 {
2341 /* Leave the 'cand' field null; we'll figure out the conversion in
2342 convert_like_real if this candidate is chosen. */
2344 }
2348 {
2352 }
2353 else
2354 {
2358 }
2365 {
2369 }
2376 }
2380 {
2384 }
2388 }
2390 static void
2394 {
2408 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
2409 conversion ops are allowed. We handle that here by just checking for
2410 boolean_type_node because other operators don't ask for it. COND_EXPR
2411 also does contextual conversion to bool for the first operand, but we
2412 handle that in build_conditional_expr, and type1 here is operand 2. */
2417 {
2424 {
2426 /* We need something for printing the candidate. */
2430 }
2432 {
2437 }
2439 }
2441 /* For COND_EXPR we rearranged the arguments; undo that now. */
2443 {
2448 complain);
2451 else
2452 {
2455 boolean_type_node,
2457 }
2458 }
2465 }
2467 static bool
2469 {
2471 }
2473 /* Returns nonzero if TYPE is a promoted arithmetic type. */
2475 static bool
2477 {
2478 /* [over.built]
2480 In this section, the term promoted integral type is used to refer
2481 to those integral types which are preserved by integral promotion
2482 (including e.g. int and long but excluding e.g. char).
2483 Similarly, the term promoted arithmetic type refers to promoted
2484 integral types plus floating types. */
2488 }
2490 /* Create any builtin operator overload candidates for the operator in
2491 question given the converted operand types TYPE1 and TYPE2. The other
2492 args are passed through from add_builtin_candidates to
2493 build_builtin_candidate.
2495 TYPE1 and TYPE2 may not be permissible, and we must filter them.
2496 If CODE is requires candidates operands of the same type of the kind
2497 of which TYPE1 and TYPE2 are, we add both candidates
2498 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
2500 static void
2504 tsubst_flags_t complain)
2505 {
2507 {
2515 }
2518 {
2520 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2521 and VQ is either volatile or empty, there exist candidate operator
2522 functions of the form
2523 VQ T& operator++(VQ T&);
2524 T operator++(VQ T&, int);
2525 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
2526 type other than bool, and VQ is either volatile or empty, there exist
2527 candidate operator functions of the form
2528 VQ T& operator--(VQ T&);
2529 T operator--(VQ T&, int);
2530 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
2531 complete object type, and VQ is either volatile or empty, there exist
2532 candidate operator functions of the form
2533 T*VQ& operator++(T*VQ&);
2534 T*VQ& operator--(T*VQ&);
2535 T* operator++(T*VQ&, int);
2536 T* operator--(T*VQ&, int); */
2542 /* FALLTHRU */
2546 {
2549 }
2552 /* 7 For every cv-qualified or cv-unqualified object type T, there
2553 exist candidate operator functions of the form
2555 T& operator*(T*);
2557 8 For every function type T, there exist candidate operator functions of
2558 the form
2559 T& operator*(T*); */
2568 /* 9 For every type T, there exist candidate operator functions of the form
2569 T* operator+(T*);
2571 10For every promoted arithmetic type T, there exist candidate operator
2572 functions of the form
2573 T operator+(T);
2574 T operator-(T); */
2579 /* FALLTHRU */
2585 /* 11For every promoted integral type T, there exist candidate operator
2586 functions of the form
2587 T operator~(T); */
2594 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
2595 is the same type as C2 or is a derived class of C2, T is a complete
2596 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
2597 there exist candidate operator functions of the form
2598 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
2599 where CV12 is the union of CV1 and CV2. */
2603 {
2611 }
2614 /* 13For every pair of promoted arithmetic types L and R, there exist can-
2615 didate operator functions of the form
2616 LR operator*(L, R);
2617 LR operator/(L, R);
2618 LR operator+(L, R);
2619 LR operator-(L, R);
2620 bool operator<(L, R);
2621 bool operator>(L, R);
2622 bool operator<=(L, R);
2623 bool operator>=(L, R);
2624 bool operator==(L, R);
2625 bool operator!=(L, R);
2626 where LR is the result of the usual arithmetic conversions between
2627 types L and R.
2629 14For every pair of types T and I, where T is a cv-qualified or cv-
2630 unqualified complete object type and I is a promoted integral type,
2631 there exist candidate operator functions of the form
2632 T* operator+(T*, I);
2633 T& operator[](T*, I);
2634 T* operator-(T*, I);
2635 T* operator+(I, T*);
2636 T& operator[](I, T*);
2638 15For every T, where T is a pointer to complete object type, there exist
2639 candidate operator functions of the form112)
2640 ptrdiff_t operator-(T, T);
2642 16For every pointer or enumeration type T, there exist candidate operator
2643 functions of the form
2644 bool operator<(T, T);
2645 bool operator>(T, T);
2646 bool operator<=(T, T);
2647 bool operator>=(T, T);
2648 bool operator==(T, T);
2649 bool operator!=(T, T);
2651 17For every pointer to member type T, there exist candidate operator
2652 functions of the form
2653 bool operator==(T, T);
2654 bool operator!=(T, T); */
2661 {
2664 }
2665 /* FALLTHRU */
2678 {
2681 }
2683 {
2686 }
2687 /* Fall through. */
2703 {
2706 }
2709 {
2712 }
2718 /* FALLTHRU */
2721 {
2724 }
2726 {
2729 }
2732 /* 18For every pair of promoted integral types L and R, there exist candi-
2733 date operator functions of the form
2734 LR operator%(L, R);
2735 LR operator&(L, R);
2736 LR operator^(L, R);
2737 LR operator|(L, R);
2738 L operator<<(L, R);
2739 L operator>>(L, R);
2740 where LR is the result of the usual arithmetic conversions between
2741 types L and R. */
2749 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2753 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2754 type, VQ is either volatile or empty, and R is a promoted arithmetic
2755 type, there exist candidate operator functions of the form
2756 VQ L& operator=(VQ L&, R);
2757 VQ L& operator*=(VQ L&, R);
2758 VQ L& operator/=(VQ L&, R);
2759 VQ L& operator+=(VQ L&, R);
2760 VQ L& operator-=(VQ L&, R);
2762 20For every pair T, VQ), where T is any type and VQ is either volatile
2763 or empty, there exist candidate operator functions of the form
2764 T*VQ& operator=(T*VQ&, T*);
2766 21For every pair T, VQ), where T is a pointer to member type and VQ is
2767 either volatile or empty, there exist candidate operator functions of
2768 the form
2769 VQ T& operator=(VQ T&, T);
2771 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2772 unqualified complete object type, VQ is either volatile or empty, and
2773 I is a promoted integral type, there exist candidate operator func-
2774 tions of the form
2775 T*VQ& operator+=(T*VQ&, I);
2776 T*VQ& operator-=(T*VQ&, I);
2778 23For every triple L, VQ, R), where L is an integral or enumeration
2779 type, VQ is either volatile or empty, and R is a promoted integral
2780 type, there exist candidate operator functions of the form
2782 VQ L& operator%=(VQ L&, R);
2783 VQ L& operator<<=(VQ L&, R);
2784 VQ L& operator>>=(VQ L&, R);
2785 VQ L& operator&=(VQ L&, R);
2786 VQ L& operator^=(VQ L&, R);
2787 VQ L& operator|=(VQ L&, R); */
2791 {
2795 {
2798 }
2799 /* FALLTHRU */
2812 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2825 {
2828 }
2833 }
2838 /* [over.built]
2840 For every pair of promoted arithmetic types L and R, there
2841 exist candidate operator functions of the form
2843 LR operator?(bool, L, R);
2845 where LR is the result of the usual arithmetic conversions
2846 between types L and R.
2848 For every type T, where T is a pointer or pointer-to-member
2849 type, there exist candidate operator functions of the form T
2850 operator?(bool, T, T); */
2854 /* That's OK. */
2857 /* Otherwise, the types should be pointers. */
2861 /* We don't check that the two types are the same; the logic
2862 below will actually create two candidates; one in which both
2863 parameter types are TYPE1, and one in which both parameter
2864 types are TYPE2. */
2875 }
2877 /* Make sure we don't create builtin candidates with dependent types. */
2881 {
2882 /* Try to recover if one of the types is non-dependent. But if
2883 there's only one type, there's nothing we can do. */
2886 /* And we lose if both are dependent. */
2889 /* Or if they have different forms. */
2897 }
2899 /* If we're dealing with two pointer types or two enumeral types,
2900 we need candidates for both of them. */
2909 {
2911 {
2913 error_mark_node,
2914 error_mark_node,
2915 CPO_CONVERSION,
2916 tf_none);
2918 {
2919 build_builtin_candidate
2923 }
2924 }
2926 build_builtin_candidate
2928 build_builtin_candidate
2931 }
2933 build_builtin_candidate
2935 }
2937 tree
2939 {
2945 }
2947 /* There are three conditions of builtin candidates:
2949 1) bool-taking candidates. These are the same regardless of the input.
2950 2) pointer-pair taking candidates. These are generated for each type
2951 one of the input types converts to.
2952 3) arithmetic candidates. According to the standard, we should generate
2953 all of these, but I'm trying not to...
2955 Here we generate a superset of the possible candidates for this particular
2956 case. That is a subset of the full set the standard defines, plus some
2957 other cases which the standard disallows. add_builtin_candidate will
2958 filter out the invalid set. */
2960 static void
2964 {
2968 /* TYPES[i] is the set of possible builtin-operator parameter types
2969 we will consider for the Ith argument. */
2974 {
2977 else
2979 }
2982 {
2983 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2984 and VQ is either volatile or empty, there exist candidate operator
2985 functions of the form
2986 VQ T& operator++(VQ T&); */
2996 /* 24There also exist candidate operator functions of the form
2997 bool operator!(bool);
2998 bool operator&&(bool, bool);
2999 bool operator||(bool, bool); */
3002 build_builtin_candidate
3009 build_builtin_candidate
3027 /* Fall through. */
3031 }
3037 {
3039 ;
3041 {
3042 tree convs;
3050 {
3055 }
3061 {
3074 {
3080 }
3084 }
3085 }
3086 else
3087 {
3092 {
3098 }
3100 }
3101 }
3103 /* Run through the possible parameter types of both arguments,
3104 creating candidates with those parameter types. */
3106 {
3108 tree u;
3112 add_builtin_candidate
3115 else
3116 add_builtin_candidate
3119 }
3123 }
3126 /* If TMPL can be successfully instantiated as indicated by
3127 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
3129 TMPL is the template. EXPLICIT_TARGS are any explicit template
3130 arguments. ARGLIST is the arguments provided at the call-site.
3131 This does not change ARGLIST. The RETURN_TYPE is the desired type
3132 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
3133 as for add_function_candidate. If an OBJ is supplied, FLAGS and
3134 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
3142 tsubst_flags_t complain)
3143 {
3153 tree arg;
3155 tree fn;
3160 /* We don't do deduction on the in-charge parameter, the VTT
3161 parameter or 'this'. */
3163 {
3167 /* We're deducing for a call to the result of a template conversion
3169 else
3171 }
3176 {
3179 else
3181 }
3189 {
3190 /* 12.8/6 says, "A declaration of a constructor for a class X is
3191 ill-formed if its first parameter is of type (optionally cv-qualified)
3192 X and either there are no other parameters or else all other
3193 parameters have default arguments. A member function template is never
3194 instantiated to produce such a constructor signature."
3196 So if we're trying to copy an object of the containing class, don't
3197 consider a template constructor that has a first parameter type that
3198 is just a template parameter, as we would deduce a signature that we
3199 would then reject in the code below. */
3201 {
3206 {
3210 }
3211 }
3212 }
3219 {
3222 }
3226 {
3229 }
3236 args_without_in_chrg,
3237 nargs_without_in_chrg,
3242 {
3243 /* Don't repeat unification later if it already resulted in errors. */
3247 nargs_without_in_chrg,
3249 else
3252 }
3254 /* Now the explicit specifier might have been deduced; check if this
3255 declaration is explicit. If it is and we're ignoring non-converting
3256 constructors, don't add this function to the set of candidates. */
3261 {
3264 ctype))
3265 {
3266 /* We're trying to produce a constructor with a prohibited signature,
3267 as discussed above; handle here any cases we didn't catch then,
3268 such as X(X<T>). */
3271 }
3272 }
3275 /* Aha, this is a conversion function. */
3278 else
3283 /* This situation can occur if a member template of a template
3284 class is specialized. Then, instantiate_template might return
3285 an instantiation of the specialization, in which case the
3286 DECL_TI_TEMPLATE field will point at the original
3287 specialization. For example:
3289 template <class T> struct S { template <class U> void f(U);
3290 template <> void f(int) {}; };
3291 S<double> sd;
3292 sd.f(3);
3294 Here, TMPL will be template <class U> S<double>::f(U).
3295 And, instantiate template will give us the specialization
3296 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
3297 for this will point at template <class T> template <> S<T>::f(int),
3298 so that we can find the definition. For the purposes of
3299 overload resolution, however, we want the original TMPL. */
3301 else
3306 fail:
3309 }
3318 {
3319 return
3324 }
3326 /* Create an overload candidate for the conversion function template TMPL,
3327 returning RETURN_TYPE, which will be invoked for expression OBJ to produce a
3328 pointer-to-function which will in turn be called with the argument list
3329 ARGLIST, and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
3330 passed on to implicit_conversion. */
3334 tree obj,
3338 {
3339 /* Making this work broke PR 71117 and 85118, so until the committee resolves
3340 core issue 2189, let's disable this candidate if there are any call
3341 operators. */
3345 return
3349 complain);
3350 }
3352 /* The CANDS are the set of candidates that were considered for
3353 overload resolution. Return the set of viable candidates, or CANDS
3354 if none are viable. If any of the candidates were viable, set
3355 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
3356 considered viable only if it is strictly viable. */
3362 {
3368 /* Be strict inside templates, since build_over_call won't actually
3369 do the conversions to get pedwarns. */
3379 {
3383 {
3384 /* Be strict in the presence of a viable candidate. Also if
3385 there are template candidates, so that we get deduction errors
3386 for them instead of silently preferring a bad conversion. */
3389 {
3390 /* Put any spliced near matches back onto the main list so
3391 that we see them if there is no strict match. */
3397 }
3398 }
3401 {
3409 }
3410 else
3412 }
3415 }
3417 static bool
3419 {
3424 }
3426 /* OBJ is being used in an expression like "OBJ.f (...)". In other
3427 words, it is about to become the "this" pointer for a member
3428 function call. Take the address of the object. */
3430 static tree
3432 {
3433 /* In a template, we are only concerned about the type of the
3434 expression, so we can take a shortcut. */
3439 }
3441 /* Returns true iff functions are equivalent. Equivalent functions are
3442 not '==' only if one is a function-local extern function or if
3443 both are extern "C". */
3447 {
3456 }
3458 /* Print information about a candidate FN being rejected due to INFO. */
3460 static void
3462 tree fn)
3463 {
3468 {
3469 /* Conversion of implicit `this' argument failed. */
3471 /* A bad conversion for 'this' must be discarding cv-quals. */
3474 from);
3475 else
3479 }
3481 {
3486 tf_warning_or_error);
3487 }
3489 /* Conversion of conversion function return value failed. */
3492 else
3493 {
3498 }
3499 }
3501 /* Print information about a candidate with WANT parameters and we found
3502 HAVE. */
3504 static void
3506 {
3511 }
3513 /* Print information about one overload candidate CANDIDATE. MSGSTR
3514 is the text to print before the candidate itself.
3516 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
3517 to have been run through gettext by the caller. This wart makes
3518 life simpler in print_z_candidates and for the translators. */
3520 static void
3523 {
3533 {
3544 else
3547 }
3554 else
3557 {
3560 }
3561 /* Give the user some information about why this candidate failed. */
3563 {
3567 {
3580 "cannot be converted to %qT with a qualification "
3586 "conversion function specialization to %qT is not an "
3591 /* We use template_unification_error_rejection if unification caused
3592 actual non-SFINAE errors, in which case we don't need to repeat
3593 them here. */
3595 {
3599 }
3600 /* Re-run template unification with diagnostics. */
3604 (make_tree_vec
3615 " a constructor taking a single argument of its own "
3619 {
3623 }
3627 "initialization from an expression of the same or derived "
3632 /* This candidate didn't have any issues or we failed to
3633 handle a particular code. Either way... */
3635 }
3636 }
3637 }
3639 static void
3641 {
3648 /* Remove non-viable deleted candidates. */
3651 {
3656 else
3658 }
3659 /* ...if there are any non-deleted ones. */
3663 /* There may be duplicates in the set of candidates. We put off
3664 checking this condition as long as possible, since we have no way
3665 to eliminate duplicates from a set of functions in less than n^2
3666 time. Now we are about to emit an error message, so it is more
3667 permissible to go slowly. */
3669 {
3671 /* Skip builtin candidates and conversion functions. */
3676 {
3680 else
3682 }
3683 }
3687 }
3689 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3690 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3691 the result of the conversion function to convert it to the final
3692 desired type. Merge the two sequences into a single sequence,
3693 and return the merged sequence. */
3697 {
3703 /* Find the end of the second conversion sequence. */
3705 {
3706 /* The entire sequence is a user-conversion sequence. */
3710 }
3713 /* We're binding a reference directly to the result of the conversion.
3714 build_user_type_conversion_1 stripped the REFERENCE_TYPE from the return
3715 type, but we want it back. */
3718 /* Replace the identity conversion with the user conversion
3719 sequence. */
3723 }
3725 /* Handle overload resolution for initializing an object of class type from
3726 an initializer list. First we look for a suitable constructor that
3727 takes a std::initializer_list; if we don't find one, we then look for a
3728 non-list constructor.
3730 Parameters are as for add_candidates, except that the arguments are in
3731 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and
3732 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3734 static void
3741 tsubst_flags_t complain)
3742 {
3745 /* We're looking for a ctor for list-initialization. */
3747 /* And we don't allow narrowing conversions. We also use this flag to
3748 avoid the copy constructor call for copy-list-initialization. */
3754 /* Always use the default constructor if the list is empty (DR 990). */
3757 ;
3758 /* If the class has a list ctor, try passing the list as a single
3759 argument first, but only consider list ctors. */
3761 {
3768 }
3770 /* Expand the CONSTRUCTOR into a new argument vec. */
3778 /* We aren't looking for list-ctors anymore. */
3780 /* We allow more user-defined conversions within an init-list. */
3786 }
3788 /* Returns the best overload candidate to perform the requested
3789 conversion. This function is used for three the overloading situations
3790 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3791 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as
3792 per [dcl.init.ref], so we ignore temporary bindings. */
3796 tsubst_flags_t complain)
3797 {
3799 tree fromtype;
3813 /* We represent conversion within a hierarchy using RVALUE_CONV and
3814 BASE_CONV, as specified by [over.best.ics]; these become plain
3815 constructor calls, as specified in [dcl.init]. */
3820 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid
3821 creating a garbage BASELINK; constructors can't be inherited. */
3825 {
3830 {
3831 /* [class.conv.fct] A conversion function is never used to
3832 convert a (possibly cv-qualified) object to the (possibly
3833 cv-qualified) same object type (or a reference to it), to a
3834 (possibly cv-qualified) base class of that type (or a
3835 reference to it)... */
3836 }
3837 else
3839 }
3846 /* It's OK to bind a temporary for converting constructor arguments, but
3847 not in converting the return value of a conversion operator. */
3853 {
3858 /* We should never try to call the abstract or base constructor
3859 from here. */
3865 {
3866 /* List-initialization. */
3870 }
3871 else
3872 {
3876 }
3879 {
3882 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3883 set, then this is copy-initialization. In that case, "The
3884 result of the call is then used to direct-initialize the
3885 object that is the destination of the copy-initialization."
3886 [dcl.init]
3888 We represent this in the conversion sequence with an
3889 rvalue conversion, which means a constructor call. */
3892 cand->second_conv
3894 }
3895 }
3898 {
3901 else
3903 }
3906 {
3910 /* If we are called to convert to a reference type, we are trying to
3911 find a direct binding, so don't even consider temporaries. If
3912 we don't find a direct binding, the caller will try again to
3913 look for a temporary binding. */
3924 {
3926 conversion *ics
3928 rettype,
3931 complain);
3933 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
3934 copy-initialization. In that case, "The result of the
3935 call is then used to direct-initialize the object that is
3936 the destination of the copy-initialization." [dcl.init]
3938 We represent this in the conversion sequence with an
3939 rvalue conversion, which means a constructor call. But
3940 don't add a second rvalue conversion if there's already
3941 one there. Which there really shouldn't be, but it's
3942 harmless since we'd add it here anyway. */
3950 {
3955 }
3958 {
3959 /* 13.3.1.5: For direct-initialization, those explicit
3960 conversion functions that are not hidden within S and
3961 yield type T or a type that can be converted to type T
3962 with a qualification conversion (4.4) are also candidate
3963 functions. */
3964 /* 13.3.1.6 doesn't have a parallel restriction, but it should;
3965 I've raised this issue with the committee. --jason 9/2011 */
3968 }
3970 {
3972 cand->reason
3976 }
3979 {
3980 /* 13.3.3.1.2: If the user-defined conversion is specified by
3981 a specialization of a conversion function template, the
3982 second standard conversion sequence shall have exact match
3983 rank. */
3986 }
3987 }
3988 }
3992 {
3996 }
4000 {
4002 {
4003 auto_diagnostic_group d;
4007 }
4016 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
4017 ambiguous conversion is no worse than another user-defined
4018 conversion. */
4021 }
4023 tree convtype;
4027 /* DR 5: [in the first step of copy-initialization]...if the function
4028 is a constructor, the call initializes a temporary of the
4029 cv-unqualified version of the destination type. */
4031 else
4033 /* Build the user conversion sequence. */
4034 conv = build_conv
4036 convtype,
4042 /* We're performing the maybe-rvalue overload resolution and
4043 a conversion function is in play. Reject converting the return
4044 value of the conversion function to a base class. */
4050 /* Remember that this was a list-initialization. */
4054 /* Combine it with the second conversion sequence. */
4059 }
4061 /* Wrapper for above. */
4063 tree
4065 tsubst_flags_t complain)
4066 {
4068 tree ret;
4074 {
4077 else
4078 {
4081 }
4082 }
4083 else
4088 }
4090 /* Subroutine of convert_nontype_argument.
4092 EXPR is an expression used in a context that requires a converted
4093 constant-expression, such as a template non-type parameter. Do any
4094 necessary conversions (that are permitted for converted
4095 constant-expressions) to convert it to the desired type.
4097 If conversion is successful, returns the converted expression;
4098 otherwise, returns error_mark_node. */
4100 tree
4102 {
4105 tree t;
4111 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4118 /* A converted constant expression of type T is an expression, implicitly
4119 converted to type T, where the converted expression is a constant
4120 expression and the implicit conversion sequence contains only
4122 * user-defined conversions,
4123 * lvalue-to-rvalue conversions (7.1),
4124 * array-to-pointer conversions (7.2),
4125 * function-to-pointer conversions (7.3),
4126 * qualification conversions (7.5),
4127 * integral promotions (7.6),
4128 * integral conversions (7.8) other than narrowing conversions (11.6.4),
4129 * null pointer conversions (7.11) from std::nullptr_t,
4130 * null member pointer conversions (7.12) from std::nullptr_t, and
4131 * function pointer conversions (7.13),
4133 and where the reference binding (if any) binds directly. */
4138 {
4140 {
4141 /* A conversion function is OK. If it isn't constexpr, we'll
4142 complain later that the argument isn't constant. */
4144 /* The lvalue-to-rvalue conversion is OK. */
4146 /* Array-to-pointer and function-to-pointer. */
4148 /* Function pointer conversions. */
4150 /* Qualification conversions. */
4156 {
4162 }
4172 /* Integral promotion or conversion. */
4175 /* Conversion from nullptr to pointer or pointer-to-member. */
4181 /* fall through. */
4186 }
4187 }
4189 /* Avoid confusing convert_nontype_argument by introducing
4190 a redundant conversion to the same reference type. */
4193 {
4197 }
4200 {
4204 }
4205 else
4206 {
4211 }
4213 /* Free all the conversions we allocated. */
4217 }
4219 /* Do any initial processing on the arguments to a function call. */
4223 {
4225 tree arg;
4228 {
4232 {
4236 }
4239 }
4241 }
4243 /* Perform overload resolution on FN, which is called with the ARGS.
4245 Return the candidate function selected by overload resolution, or
4246 NULL if the event that overload resolution failed. In the case
4247 that overload resolution fails, *CANDIDATES will be the set of
4248 candidates considered, and ANY_VIABLE_P will be set to true or
4249 false to indicate whether or not any of the candidates were
4250 viable.
4252 The ARGS should already have gone through RESOLVE_ARGS before this
4253 function is called. */
4260 {
4262 tree explicit_targs;
4273 /* Check FN. */
4280 {
4284 }
4286 /* Add the various candidate functions. */
4291 LOOKUP_NORMAL,
4297 else
4302 }
4304 /* Print an error message about being unable to build a call to FN with
4305 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
4306 be located; CANDIDATES is a possibly empty list of such
4307 functions. */
4309 static void
4312 {
4315 {
4318 }
4324 auto_diagnostic_group d;
4328 else
4333 }
4335 /* Return an expression for a call to FN (a namespace-scope function,
4336 or a static member function) with the ARGS. This may change
4337 ARGS. */
4339 tree
4341 tsubst_flags_t complain)
4342 {
4346 tree result;
4349 {
4353 }
4358 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4362 complain);
4365 {
4367 {
4368 // If there is a single (non-viable) function candidate,
4369 // let the error be diagnosed by cp_build_function_call_vec.
4374 // Otherwise, emit notes for non-viable candidates.
4376 }
4378 }
4379 else
4380 {
4382 /* If fn is template_id_expr, the call has explicit template arguments
4383 (e.g. func<int>(5)), communicate this info to build_over_call
4384 through flags so that later we can use it to decide whether to warn
4385 about peculiar null pointer conversion. */
4387 {
4388 /* If overload resolution selects a specialization of a
4389 function concept for non-dependent template arguments,
4390 the expression is true if the constraints are satisfied
4391 and false otherwise.
4393 NOTE: This is an extension of Concepts Lite TS that
4394 allows constraints to be used in expressions. */
4396 {
4402 }
4405 }
4408 }
4410 /* Free all the conversions we allocated. */
4414 }
4416 /* Build a call to a global operator new. FNNAME is the name of the
4417 operator (either "operator new" or "operator new[]") and ARGS are
4418 the arguments provided. This may change ARGS. *SIZE points to the
4419 total number of bytes required by the allocation, and is updated if
4420 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
4421 be used. If this function determines that no cookie should be
4422 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK
4423 is not NULL_TREE, it is evaluated before calculating the final
4424 array size, and if it fails, the array size is replaced with
4425 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN
4426 is non-NULL, it will be set, upon return, to the allocation
4427 function called. */
4429 tree
4434 {
4436 tree fns;
4443 /* Set to (size_t)-1 if the size check fails. */
4445 {
4451 }
4457 /* Based on:
4459 [expr.new]
4461 If this lookup fails to find the name, or if the allocated type
4462 is not a class type, the allocation function's name is looked
4463 up in the global scope.
4465 we disregard block-scope declarations of "operator new". */
4470 {
4477 /* If no aligned allocation function matches, try again without the
4478 alignment. */
4479 }
4481 /* Figure out what function is being called. */
4484 complain);
4486 /* If no suitable function could be found, issue an error message
4487 and give up. */
4489 {
4493 }
4495 /* If a cookie is required, add some extra space. Whether
4496 or not a cookie is required cannot be determined until
4497 after we know which function was called. */
4499 {
4501 tree arg_types;
4504 /* Skip the size_t parameter. */
4506 /* Check the remaining parameters (if any). */
4510 ptr_type_node))
4512 /* If we need a cookie, adjust the number of bytes allocated. */
4514 {
4515 /* Update the total size. */
4518 {
4519 /* Set to (size_t)-1 if the size check fails. */
4523 }
4524 /* Update the argument list to reflect the adjusted size. */
4526 }
4527 else
4529 }
4531 /* Tell our caller which function we decided to call. */
4535 /* Build the CALL_EXPR. */
4537 }
4539 /* Build a new call to operator(). This may change ARGS. */
4541 static tree
4543 {
4560 {
4562 /* It's no good looking for an overloaded operator() on a
4563 pointer-to-member-function. */
4567 }
4570 {
4574 }
4575 else
4579 {
4583 }
4585 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4589 {
4597 }
4602 {
4610 {
4617 add_template_conv_candidate
4621 else
4625 }
4626 }
4628 /* Be strict here because if we choose a bad conversion candidate, the
4629 errors we get won't mention the call context. */
4632 {
4634 {
4635 auto_diagnostic_group d;
4639 }
4641 }
4642 else
4643 {
4646 {
4648 {
4649 auto_diagnostic_group d;
4653 }
4655 }
4660 else
4661 {
4665 else
4666 {
4669 }
4672 }
4673 }
4675 /* Free all the conversions we allocated. */
4679 }
4681 /* Wrapper for above. */
4683 tree
4685 {
4686 tree ret;
4691 }
4693 /* Called by op_error to prepare format strings suitable for the error
4694 function. It concatenates a prefix (controlled by MATCH), ERRMSG,
4695 and a suffix (controlled by NTYPES). */
4699 {
4709 else
4713 }
4715 static void
4718 {
4723 {
4729 else
4741 else
4751 else
4762 else
4772 else
4777 else
4781 else
4786 }
4787 }
4789 /* Return the implicit conversion sequence that could be used to
4790 convert E1 to E2 in [expr.cond]. */
4794 {
4800 /* [expr.cond]
4802 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
4803 implicitly converted (clause _conv_) to the type "lvalue reference to
4804 T2", subject to the constraint that in the conversion the
4805 reference must bind directly (_dcl.init.ref_) to an lvalue.
4807 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
4808 implicitly converted to the type "rvalue reference to T2", subject to
4809 the constraint that the reference must bind directly. */
4811 {
4814 t1,
4815 e1,
4817 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND
4819 complain);
4822 }
4824 /* If E2 is a prvalue or if neither of the conversions above can be done
4825 and at least one of the operands has (possibly cv-qualified) class
4826 type: */
4830 /* [expr.cond]
4832 If E1 and E2 have class type, and the underlying class types are
4833 the same or one is a base class of the other: E1 can be converted
4834 to match E2 if the class of T2 is the same type as, or a base
4835 class of, the class of T1, and the cv-qualification of T2 is the
4836 same cv-qualification as, or a greater cv-qualification than, the
4837 cv-qualification of T1. If the conversion is applied, E1 is
4838 changed to an rvalue of type T2 that still refers to the original
4839 source class object (or the appropriate subobject thereof). */
4842 {
4844 {
4849 else
4852 }
4853 else
4855 }
4856 else
4857 /* [expr.cond]
4859 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
4860 converted to the type that expression E2 would have if E2 were
4861 converted to an rvalue (or the type it has, if E2 is an rvalue). */
4864 }
4866 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4867 arguments to the conditional expression. */
4869 static tree
4871 tsubst_flags_t complain)
4872 {
4873 tree arg2_type;
4874 tree arg3_type;
4883 /* As a G++ extension, the second argument to the conditional can be
4884 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
4885 c'.) If the second operand is omitted, make sure it is
4886 calculated only once. */
4888 {
4896 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
4899 else
4901 }
4903 /* If something has already gone wrong, just pass that fact up the
4904 tree. */
4914 {
4917 /* If arg1 is another cond_expr choosing between -1 and 0,
4918 then we can use its comparison. It may help to avoid
4919 additional comparison, produce more accurate diagnostics
4920 and enables folding. */
4930 /* force_rvalue can return error_mark on valid arguments. */
4941 {
4942 /* Rely on the error messages of the scalar version. */
4951 {
4959 }
4963 /* We could pass complain & tf_warning to unsafe_conversion_p,
4964 but the warnings (like Wsign-conversion) have already been
4965 given by the scalar build_conditional_expr_1. We still check
4966 unsafe_conversion_p to forbid truncating long long -> float. */
4968 {
4973 }
4975 {
4980 }
4990 }
4993 {
4999 {
5003 {
5009 }
5011 {
5017 }
5020 }
5021 }
5027 {
5030 "incompatible vector types in conditional expression: "
5034 }
5037 {
5040 }
5042 }
5044 /* [expr.cond]
5046 The first expression is implicitly converted to bool (clause
5047 _conv_). */
5049 LOOKUP_NORMAL);
5053 /* [expr.cond]
5055 If either the second or the third operand has type (possibly
5056 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
5057 array-to-pointer (_conv.array_), and function-to-pointer
5058 (_conv.func_) standard conversions are performed on the second
5059 and third operands. */
5063 {
5064 /* [expr.cond]
5066 One of the following shall hold:
5068 --The second or the third operand (but not both) is a
5069 throw-expression (_except.throw_); the result is of the type
5070 and value category of the other.
5072 --Both the second and the third operands have type void; the
5073 result is of type void and is a prvalue. */
5076 {
5079 }
5082 {
5085 }
5087 {
5090 }
5091 else
5092 {
5094 {
5097 "second operand to the conditional operator "
5098 "is of type %<void%>, but the third operand is "
5100 else
5102 "third operand to the conditional operator "
5103 "is of type %<void%>, but the second operand is "
5105 }
5107 }
5110 }
5111 /* [expr.cond]
5113 Otherwise, if the second and third operand have different types,
5114 and either has (possibly cv-qualified) class type, or if both are
5115 glvalues of the same value category and the same type except for
5116 cv-qualification, an attempt is made to convert each of those operands
5117 to the type of the other. */
5121 arg3_type)
5124 {
5129 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5135 /* [expr.cond]
5137 If both can be converted, or one can be converted but the
5138 conversion is ambiguous, the program is ill-formed. If
5139 neither can be converted, the operands are left unchanged and
5140 further checking is performed as described below. If exactly
5141 one conversion is possible, that conversion is applied to the
5142 chosen operand and the converted operand is used in place of
5143 the original operand for the remainder of this section. */
5148 {
5150 {
5157 else
5159 }
5161 }
5163 {
5167 /* Even if CONV2 is a valid conversion, the result of the
5168 conversion may be invalid. For example, if ARG3 has type
5169 "volatile X", and X does not have a copy constructor
5170 accepting a "volatile X&", then even if ARG2 can be
5171 converted to X, the conversion will fail. */
5175 }
5177 {
5184 }
5186 /* Free all the conversions we allocated. */
5192 /* If, after the conversion, both operands have class type,
5193 treat the cv-qualification of both operands as if it were the
5194 union of the cv-qualification of the operands.
5196 The standard is not clear about what to do in this
5197 circumstance. For example, if the first operand has type
5198 "const X" and the second operand has a user-defined
5199 conversion to "volatile X", what is the type of the second
5200 operand after this step? Making it be "const X" (matching
5201 the first operand) seems wrong, as that discards the
5202 qualification without actually performing a copy. Leaving it
5203 as "volatile X" seems wrong as that will result in the
5204 conditional expression failing altogether, even though,
5205 according to this step, the one operand could be converted to
5206 the type of the other. */
5214 }
5216 /* [expr.cond]
5218 If the second and third operands are glvalues of the same value
5219 category and have the same type, the result is of that type and
5220 value category. */
5224 {
5229 }
5231 /* [expr.cond]
5233 Otherwise, the result is an rvalue. If the second and third
5234 operand do not have the same type, and either has (possibly
5235 cv-qualified) class type, overload resolution is used to
5236 determine the conversions (if any) to be applied to the operands
5237 (_over.match.oper_, _over.built_). */
5241 {
5246 /* Rearrange the arguments so that add_builtin_candidate only has
5247 to know about two args. In build_builtin_candidate, the
5248 arguments are unscrambled. */
5253 COND_EXPR,
5254 NOP_EXPR,
5256 args,
5259 /* [expr.cond]
5261 If the overload resolution fails, the program is
5262 ill-formed. */
5265 {
5270 }
5273 {
5275 {
5276 auto_diagnostic_group d;
5279 }
5281 }
5283 /* [expr.cond]
5285 Otherwise, the conversions thus determined are applied, and
5286 the converted operands are used in place of the original
5287 operands for the remainder of this section. */
5296 }
5298 /* [expr.cond]
5300 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
5301 and function-to-pointer (_conv.func_) standard conversions are
5302 performed on the second and third operands.
5304 We need to force the lvalue-to-rvalue conversion here for class types,
5305 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
5306 that isn't wrapped with a TARGET_EXPR plays havoc with exception
5307 regions. */
5320 /* [expr.cond]
5322 After those conversions, one of the following shall hold:
5324 --The second and third operands have the same type; the result is of
5325 that type. */
5328 /* [expr.cond]
5330 --The second and third operands have arithmetic or enumeration
5331 type; the usual arithmetic conversions are performed to bring
5332 them to a common type, and the result is of that type. */
5337 {
5338 /* In this case, there is always a common type. */
5340 arg3_type);
5343 "implicit conversion from %qH to %qI to "
5345 loc);
5349 {
5353 /* Two enumerators from the same enumeration can have different
5359 }
5366 {
5370 }
5374 }
5375 /* [expr.cond]
5377 --The second and third operands have pointer type, or one has
5378 pointer type and the other is a null pointer constant; pointer
5379 conversions (_conv.ptr_) and qualification conversions
5380 (_conv.qual_) are performed to bring them to their composite
5381 pointer type (_expr.rel_). The result is of the composite
5382 pointer type.
5384 --The second and third operands have pointer to member type, or
5385 one has pointer to member type and the other is a null pointer
5386 constant; pointer to member conversions (_conv.mem_) and
5387 qualification conversions (_conv.qual_) are performed to bring
5388 them to a common type, whose cv-qualification shall match the
5389 cv-qualification of either the second or the third operand.
5390 The result is of the common type. */
5398 {
5401 complain);
5406 }
5409 {
5414 }
5419 valid_operands:
5421 {
5422 /* Let lvalue_kind know this was a glvalue. */
5425 }
5429 /* If the ARG2 and ARG3 are the same and don't have side-effects,
5430 warn here, because the COND_EXPR will be turned into ARG2. */
5437 /* We can't use result_type below, as fold might have returned a
5438 throw_expr. */
5441 {
5442 /* Expand both sides into the same slot, hopefully the target of
5443 the ?: expression. We used to check for TARGET_EXPRs here,
5444 but now we sometimes wrap them in NOP_EXPRs so the test would
5445 fail. */
5448 /* If this expression is an rvalue, but might be mistaken for an
5449 lvalue, we must add a NON_LVALUE_EXPR. */
5451 }
5452 else
5456 }
5458 /* Wrapper for above. */
5460 tree
5462 tsubst_flags_t complain)
5463 {
5464 tree ret;
5469 }
5471 /* OPERAND is an operand to an expression. Perform necessary steps
5472 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
5473 returned. */
5475 static tree
5477 {
5479 {
5482 /* Make sure the template type is instantiated now. */
5484 }
5487 }
5489 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
5490 OVERLOAD) to the CANDIDATES, returning an updated list of
5491 CANDIDATES. The ARGS are the arguments provided to the call;
5492 if FIRST_ARG is non-null it is the implicit object argument,
5493 otherwise the first element of ARGS is used if needed. The
5494 EXPLICIT_TARGS are explicit template arguments provided.
5495 TEMPLATE_ONLY is true if only template functions should be
5496 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
5497 add_function_candidate. */
5499 static void
5501 tree return_type,
5506 tsubst_flags_t complain)
5507 {
5508 tree ctype;
5512 unification_kind_t strict;
5517 /* Precalculate special handling of constructors and conversion ops. */
5520 {
5524 /* We're doing return_type(x). */
5526 else
5527 /* We're doing x.operator return_type(). */
5529 /* [over.match.funcs] For conversion functions, the function
5530 is considered to be a member of the class of the implicit
5531 object argument for the purpose of defining the type of
5532 the implicit object parameter. */
5534 }
5535 else
5536 {
5538 {
5540 /* For list-initialization we consider explicit constructors
5541 and complain if one is chosen. */
5542 check_converting
5545 }
5548 }
5552 else
5553 /* Delay creating the implicit this parameter until it is needed. */
5557 {
5569 {
5570 /* Figure out where the object arg comes from. If this
5571 function is a non-static member and we didn't get an
5572 implicit object argument, move it out of args. */
5574 {
5576 tree arg;
5583 }
5587 }
5591 fn,
5592 ctype,
5593 explicit_targs,
5594 fn_first_arg,
5595 fn_args,
5596 return_type,
5597 access_path,
5598 conversion_path,
5599 flags,
5600 strict,
5601 complain);
5604 fn,
5605 ctype,
5606 fn_first_arg,
5607 fn_args,
5608 access_path,
5609 conversion_path,
5610 flags,
5611 NULL,
5612 complain);
5613 }
5614 }
5616 /* Returns 1 if P0145R2 says that the LHS of operator CODE is evaluated first,
5617 -1 if the RHS is evaluated first, or 0 if the order is unspecified. */
5619 static int
5621 {
5623 {
5624 // 5. b @= a
5628 // 6. a[b]
5632 // 1. a.b
5633 // Not overloadable (yet).
5634 // 2. a->b
5635 // Only one argument.
5636 // 3. a->*b
5638 // 7. a << b
5640 // 8. a >> b
5646 }
5647 }
5649 static tree
5652 {
5673 {
5676 }
5683 {
5688 /* Use build_op_new_call and build_op_delete_call instead. */
5692 /* Use build_op_call instead. */
5699 /* These are saved for the sake of warn_logical_operator. */
5709 /* These are saved for the sake of maybe_warn_bool_compare. */
5714 /* =, ->, [], () must be non-static member functions. */
5718 /* FALLTHRU */
5726 }
5732 /* Use build_conditional_expr instead. */
5748 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5751 /* Add namespace-scope operators to the list of functions to
5752 consider. */
5754 {
5760 }
5766 /* Add class-member operators to the candidate set. */
5768 {
5769 tree fns;
5773 {
5776 }
5784 }
5785 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then
5786 only non-member functions that have type T1 or reference to
5787 cv-qualified-opt T1 for the first argument, if the first argument
5788 has an enumeration type, or T2 or reference to cv-qualified-opt
5789 T2 for the second argument, if the second argument has an
5790 enumeration type. Filter out those that don't match. */
5792 {
5796 {
5806 {
5812 && (same_type_ignoring_top_level_qualifiers_p
5817 }
5819 /* No argument has an appropriate type, so remove this
5820 candidate function from the list. */
5822 {
5825 }
5826 }
5827 }
5833 {
5836 /* For these, the built-in candidates set is empty
5837 [over.match.oper]/3. We don't want non-strict matches
5838 because exact matches are always possible with built-in
5839 operators. The built-in candidate set for COMPONENT_REF
5840 would be empty too, but since there are no such built-in
5841 operators, we accept non-strict matches for them. */
5848 }
5852 {
5854 {
5857 /* Don't try anything fancy if we're not allowed to produce
5858 errors. */
5862 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
5863 distinguish between prefix and postfix ++ and
5864 operator++() was used for both, so we allow this with
5865 -fpermissive. */
5866 else
5867 {
5873 }
5880 else
5886 /* The caller will deal with these. */
5896 {
5897 /* If one of the arguments of the operator represents
5898 an invalid use of member function pointer, try to report
5899 a meaningful error ... */
5904 else
5905 {
5906 /* ... Otherwise, report the more generic
5907 "no matching operator found" error */
5908 auto_diagnostic_group d;
5911 }
5912 }
5915 }
5916 }
5917 else
5918 {
5921 {
5923 {
5924 auto_diagnostic_group d;
5927 }
5929 }
5931 {
5937 else
5943 {
5948 /* This prevents build_new_function_call from discarding this
5949 function during instantiation of the enclosing template. */
5952 /* Specify evaluation order as per P0145R2. */
5955 {
5966 }
5967 }
5968 }
5969 else
5970 {
5971 /* Give any warnings we noticed during overload resolution. */
5973 {
5977 }
5979 /* Check for comparison of different enum types. */
5981 {
5993 {
5997 }
6001 }
6003 /* We need to strip any leading REF_BIND so that bitfields
6004 don't cause errors. This should not remove any important
6005 conversions, because builtins don't apply to class
6006 objects directly. */
6013 {
6017 else
6020 /* We need to call warn_logical_operator before
6021 converting arg2 to a boolean_type, but after
6022 decaying an enumerator to its value. */
6029 }
6031 {
6036 }
6038 }
6039 }
6041 user_defined_result_ready:
6043 /* Free all the conversions we allocated. */
6049 builtin:
6051 {
6066 /* Fall through. */
6079 /* Fall through. */
6112 complain),
6115 /* The caller will deal with these. */
6123 }
6125 }
6127 /* Wrapper for above. */
6129 tree
6133 {
6134 tree ret;
6140 }
6142 /* CALL was returned by some call-building function; extract the actual
6143 CALL_EXPR from any bits that have been tacked on, e.g. by
6144 convert_from_reference. */
6146 tree
6148 {
6159 }
6161 /* Returns true if FN has two parameters, of which the second has type
6162 size_t. */
6164 static bool
6166 {
6178 }
6180 /* True if T, an allocation function, has std::align_val_t as its second
6181 argument. */
6183 bool
6185 {
6191 }
6193 /* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation
6194 function (3.7.4.2 [basic.stc.dynamic.deallocation]) with a parameter of
6195 std::align_val_t. */
6197 static bool
6199 {
6203 /* A template instance is never a usual deallocation function,
6204 regardless of its signature. */
6220 }
6222 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
6223 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
6225 bool
6227 {
6228 /* A template instance is never a usual deallocation function,
6229 regardless of its signature. */
6234 /* If a class T has a member deallocation function named operator delete
6235 with exactly one parameter, then that function is a usual
6236 (non-placement) deallocation function. If class T does not declare
6237 such an operator delete but does declare a member deallocation
6238 function named operator delete with exactly two parameters, the second
6239 of which has type std::size_t (18.2), then this function is a usual
6240 deallocation function. */
6252 }
6254 /* Build a call to operator delete. This has to be handled very specially,
6255 because the restrictions on what signatures match are different from all
6256 other call instances. For a normal delete, only a delete taking (void *)
6257 or (void *, size_t) is accepted. For a placement delete, only an exact
6258 match with the placement new is accepted.
6260 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
6261 ADDR is the pointer to be deleted.
6262 SIZE is the size of the memory block to be deleted.
6263 GLOBAL_P is true if the delete-expression should not consider
6264 class-specific delete operators.
6265 PLACEMENT is the corresponding placement new call, or NULL_TREE.
6267 If this call to "operator delete" is being generated as part to
6268 deallocate memory allocated via a new-expression (as per [expr.new]
6269 which requires that if the initialization throws an exception then
6270 we call a deallocation function), then ALLOC_FN is the allocation
6271 function. */
6273 tree
6277 {
6291 /* In [class.free]
6293 If the result of the lookup is ambiguous or inaccessible, or if
6294 the lookup selects a placement deallocation function, the
6295 program is ill-formed.
6297 Therefore, we ask lookup_fnfields to complain about ambiguity. */
6298 {
6302 }
6303 else
6309 /* Strip const and volatile from addr. */
6313 {
6314 /* "A declaration of a placement deallocation function matches the
6315 declaration of a placement allocation function if it has the same
6316 number of parameters and, after parameter transformations (8.3.5),
6317 all parameter types except the first are identical."
6319 So we build up the function type we want and ask instantiate_type
6320 to get it for us. */
6331 /* "If the lookup finds the two-parameter form of a usual deallocation
6332 function (3.7.4.2) and that function, considered as a placement
6333 deallocation function, would have been selected as a match for the
6334 allocation function, the program is ill-formed." */
6336 {
6344 /* But if the class has an operator delete (void *), then that is
6345 the usual deallocation function, so we shouldn't complain
6346 about using the operator delete (void *, size_t). */
6350 {
6355 }
6356 /* Before C++14 a two-parameter global deallocation function is
6357 always a placement deallocation function, but warn if
6358 -Wc++14-compat. */
6360 {
6362 {
6363 auto_diagnostic_group d;
6366 }
6368 }
6371 {
6372 auto_diagnostic_group d;
6374 {
6375 /* Only mention C++14 for namespace-scope delete. */
6378 else
6380 "%qD is a usual (non-placement) deallocation "
6382 }
6383 }
6384 else
6386 ok:;
6387 }
6388 }
6389 else
6390 /* "Any non-placement deallocation function matches a non-placement
6391 allocation function. If the lookup finds a single matching
6392 deallocation function, that function will be called; otherwise, no
6393 deallocation function will be called." */
6395 {
6398 {
6400 {
6403 }
6405 /* -- If the type has new-extended alignment, a function with a
6406 parameter of type std::align_val_t is preferred; otherwise a
6407 function without such a parameter is preferred. If exactly one
6408 preferred function is found, that function is selected and the
6409 selection process terminates. If more than one preferred
6410 function is found, all non-preferred functions are eliminated
6411 from further consideration. */
6413 {
6419 {
6423 }
6424 }
6426 /* -- If the deallocation functions have class scope, the one
6427 without a parameter of type std::size_t is selected. */
6432 /* -- If the type is complete and if, for the second alternative
6433 (delete array) only, the operand is a pointer to a class type
6434 with a non-trivial destructor or a (possibly multi-dimensional)
6435 array thereof, the function with a parameter of type std::size_t
6436 is selected.
6438 -- Otherwise, it is unspecified whether a deallocation function
6439 with a parameter of type std::size_t is selected. */
6440 else
6441 {
6445 /* We need a cookie to determine the array size. */
6447 }
6453 }
6454 }
6456 /* If we have a matching function, call it. */
6458 {
6461 /* If the FN is a member function, make sure that it is
6462 accessible. */
6465 complain);
6467 /* Core issue 901: It's ok to new a type with deleted delete. */
6472 {
6473 /* The placement args might not be suitable for overload
6474 resolution at this point, so build the call directly. */
6484 }
6485 else
6486 {
6487 tree ret;
6493 {
6496 }
6500 }
6501 }
6503 /* [expr.new]
6505 If no unambiguous matching deallocation function can be found,
6506 propagating the exception does not cause the object's memory to
6507 be freed. */
6509 {
6513 alloc_fn);
6515 }
6521 }
6523 /* Issue diagnostics about a disallowed access of DECL, using DIAG_DECL
6524 in the diagnostics.
6526 If ISSUE_ERROR is true, then issue an error about the
6527 access, followed by a note showing the declaration.
6528 Otherwise, just show the note. */
6530 void
6532 {
6534 {
6539 }
6541 {
6546 }
6547 else
6548 {
6552 }
6553 }
6555 /* If the current scope isn't allowed to access DECL along
6556 BASETYPE_PATH, give an error. The most derived class in
6557 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
6558 the declaration to use in the error diagnostic. */
6560 bool
6563 {
6568 {
6569 /* 7.3.3/18: The additional constructors are accessible if they would be
6570 accessible when used to construct an object of the corresponding base
6571 class. */
6575 }
6578 {
6586 }
6589 }
6591 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
6592 bitwise or of LOOKUP_* values. If any errors are warnings are
6593 generated, set *DIAGNOSTIC_FN to "error" or "warning",
6594 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
6595 to NULL. */
6597 static tree
6600 {
6606 /* If the source is a packed field, calling the copy constructor will require
6607 binding the field to the reference parameter to the copy constructor, and
6608 we'll end up with an infinite loop. If we can use a bitwise copy, then
6609 do that now. */
6625 }
6627 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
6628 Also handle a subset of zero as null warnings.
6629 EXPR is implicitly converted to type TOTYPE.
6630 FN and ARGNUM are used for diagnostics. */
6632 static void
6634 {
6635 /* Issue warnings about peculiar, but valid, uses of NULL. */
6638 {
6639 source_location loc =
6646 else
6649 }
6651 /* Issue warnings if "false" is converted to a NULL pointer */
6654 {
6657 "converting %<false%> to pointer type for argument %P "
6659 else
6662 }
6663 /* Handle zero as null pointer warnings for cases other
6664 than EQ_EXPR and NE_EXPR */
6667 {
6668 source_location loc =
6671 }
6672 }
6674 /* We gave a diagnostic during a conversion. If this was in the second
6675 standard conversion sequence of a user-defined conversion sequence, say
6676 which user-defined conversion. */
6678 static void
6680 {
6684 {
6688 }
6689 }
6691 /* Locate the parameter with the given index within FNDECL.
6692 ARGNUM is zero based, -1 indicates the `this' argument of a method.
6693 Return the location of the FNDECL itself if there are problems. */
6695 location_t
6697 {
6699 tree param;
6701 /* Locate param by index within DECL_ARGUMENTS (fndecl). */
6705 ;
6707 /* If something went wrong (e.g. if we have a builtin and thus no arguments),
6708 return the location of FNDECL. */
6713 }
6715 /* Perform the conversions in CONVS on the expression EXPR. FN and
6716 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
6717 indicates the `this' argument of a method. INNER is nonzero when
6718 being called to continue a conversion chain. It is negative when a
6719 reference binding will be applied, positive otherwise. If
6720 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
6721 conversions will be emitted if appropriate. If C_CAST_P is true,
6722 this conversion is coming from a C-style cast; in that case,
6723 conversions to inaccessible bases are permitted. */
6725 static tree
6729 {
6731 diagnostic_t diag_kind;
6747 {
6751 /* Give a helpful error if this is bad because of excess braces. */
6756 {
6762 }
6764 /* Give a helpful error if this is bad because a conversion to bool
6765 from std::nullptr_t requires direct-initialization. */
6773 {
6775 {
6776 auto_diagnostic_group d;
6779 totype);
6785 complain);
6789 complain);
6790 else
6796 }
6798 {
6802 complain);
6804 }
6809 complain);
6812 }
6814 {
6820 }
6826 }
6832 {
6834 {
6838 /* We chose the surrogate function from add_conv_candidate, now we
6839 actually need to build the conversion. */
6845 /* When converting from an init list we consider explicit
6846 constructors, but actually trying to call one is an error. */
6849 /* Unless this is for direct-list-initialization. */
6851 /* And in C++98 a default constructor can't be explicit. */
6853 {
6859 {
6860 auto_diagnostic_group d;
6866 }
6867 else
6870 }
6872 /* If we're initializing from {}, it's value-initialization. */
6876 {
6883 {
6886 }
6888 }
6892 /* Pass LOOKUP_NO_CONVERSION so rvalue/base handling knows not to allow
6893 any more UDCs. */
6895 complain);
6897 /* If this is a constructor or a function returning an aggr type,
6898 we need to build up a TARGET_EXPR. */
6900 {
6903 /* Remember that this was list-initialization. */
6906 }
6909 }
6912 {
6918 else
6920 }
6929 /* If __null has been converted to an integer type, we do not want to
6930 continue to warn about uses of EXPR as an integer, rather than as a
6931 pointer. */
6935 /* We leave bad_p off ck_ambig because overload resolution considers
6936 it valid, it just fails when we try to perform it. So we need to
6937 check complain here, too. */
6939 {
6940 /* Call build_user_type_conversion again for the error. */
6948 }
6952 {
6953 /* Conversion to std::initializer_list<T>. */
6961 /* Convert all the elements. */
6963 {
6974 }
6975 /* Build up the array. */
6976 elttype = cp_build_qualified_type
6980 /* Take the address explicitly rather than via decay_conversion
6981 to avoid the error about taking the address of a temporary. */
6987 /* Build up the initializer_list object. Note: fail gracefully
6988 if the object cannot be completed because, for example, no
6989 definition is provided (c++/80956). */
6999 }
7003 {
7012 }
7015 complain);
7022 };
7032 {
7036 {
7038 {
7039 auto_diagnostic_group d;
7044 }
7046 }
7051 /* Don't introduce copies when passing arguments along to the inherited
7052 constructor. */
7054 && flag_new_inheriting_ctors
7060 /* Copy-list-initialization doesn't actually involve a copy. */
7063 /* Fall through. */
7066 {
7067 /* We are going to bind a reference directly to a base-class
7068 subobject of EXPR. */
7069 /* Build an expression for `*((base*) &expr)'. */
7073 }
7075 /* Copy-initialization where the cv-unqualified version of the source
7076 type is the same class as, or a derived class of, the class of the
7077 destination [is treated as direct-initialization]. [dcl.init] */
7080 /* This conversion is being done in the context of a user-defined
7081 conversion (i.e. the second step of copy-initialization), so
7082 don't allow any more. */
7084 else
7087 /* standard_conversion got LOOKUP_PREFER_RVALUE. */
7091 {
7092 auto_diagnostic_group d;
7097 }
7102 {
7106 {
7108 auto_diagnostic_group d;
7120 else
7127 }
7129 /* If necessary, create a temporary.
7131 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
7132 that need temporaries, even when their types are reference
7133 compatible with the type of reference being bound, so the
7134 upcoming call to cp_build_addr_expr doesn't fail. */
7138 {
7139 /* Otherwise, a temporary of type "cv1 T1" is created and
7140 initialized from the initializer expression using the rules
7141 for a non-reference copy-initialization (8.5). */
7150 {
7151 /* If the reference is volatile or non-const, we
7152 cannot create a temporary. */
7159 else
7163 }
7164 /* If the source is a packed field, and we must use a copy
7165 constructor, then building the target expr will require
7166 binding the field to the reference parameter to the
7167 copy constructor, and we'll end up with an infinite
7168 loop. If we can use a bitwise copy, then we'll be
7169 OK. */
7173 {
7177 }
7179 {
7182 }
7184 }
7186 /* Take the address of the thing to which we will bind the
7187 reference. */
7192 /* Convert it to a pointer to the type referred to by the
7193 reference. This will adjust the pointer if a derived to
7194 base conversion is being performed. */
7197 /* Convert the pointer to the desired reference type. */
7199 }
7205 /* ??? Should the address of a transaction-safe pointer point to the TM
7206 clone, and this conversion look up the primary function? */
7210 /* Warn about deprecated conversion if appropriate. */
7226 }
7236 else
7240 }
7242 /* ARG is being passed to a varargs function. Perform any conversions
7243 required. Return the converted value. */
7245 tree
7247 {
7248 tree arg_type;
7251 /* [expr.call]
7253 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
7254 standard conversions are performed. */
7257 /* [expr.call]
7259 If the argument has integral or enumeration type that is subject
7260 to the integral promotions (_conv.prom_), or a floating point
7261 type that is subject to the floating point promotion
7262 (_conv.fpprom_), the value of the argument is converted to the
7263 promoted type before the call. */
7268 {
7272 "implicit conversion from %qH to %qI when passing "
7276 }
7280 {
7282 {
7284 complain);
7294 }
7295 else
7297 }
7303 /* In a template (or ill-formed code), we can have an incomplete type
7304 even after require_complete_type_sfinae, in which case we don't know
7305 whether it has trivial copy or not. */
7308 {
7309 /* [expr.call] 5.2.2/7:
7310 Passing a potentially-evaluated argument of class type (Clause 9)
7311 with a non-trivial copy constructor or a non-trivial destructor
7312 with no corresponding parameter is conditionally-supported, with
7313 implementation-defined semantics.
7315 We support it as pass-by-invisible-reference, just like a normal
7316 value parameter.
7318 If the call appears in the context of a sizeof expression,
7319 it is not potentially-evaluated. */
7322 {
7326 "passing objects of non-trivially-copyable "
7328 arg_type);
7330 }
7331 /* Build up a real lvalue-to-rvalue conversion in case the
7332 copy constructor is trivial but not callable. */
7336 }
7339 }
7341 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
7343 tree
7345 {
7347 {
7351 }
7361 {
7364 }
7368 {
7369 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat
7370 it as pass by invisible reference. */
7372 "receiving objects of non-trivially-copyable type %q#T "
7378 }
7382 /* Wrap the VA_ARG_EXPR in a TARGET_EXPR now so other code doesn't need to
7383 know how to handle it. */
7386 }
7388 /* TYPE has been given to va_arg. Apply the default conversions which
7389 would have happened when passed via ellipsis. Return the promoted
7390 type, or the passed type if there is no change. */
7392 tree
7394 {
7395 tree promote;
7397 /* Perform the array-to-pointer and function-to-pointer
7398 conversions. */
7406 }
7408 /* ARG is a default argument expression being passed to a parameter of
7409 the indicated TYPE, which is a parameter to FN. PARMNUM is the
7410 zero-based argument number. Do any required conversions. Return
7411 the converted value. */
7414 void
7418 void
7422 tree
7424 tsubst_flags_t complain)
7425 {
7427 tree t;
7429 /* See through clones. */
7431 /* And inheriting ctors. */
7435 /* Detect recursion. */
7438 {
7442 }
7444 /* If the ARG is an unparsed default argument expression, the
7445 conversion cannot be performed. */
7447 {
7452 }
7459 /* Due to:
7461 [dcl.fct.default]
7463 The names in the expression are bound, and the semantic
7464 constraints are checked, at the point where the default
7465 expressions appears.
7467 we must not perform access checks here. */
7469 /* We must make a copy of ARG, in case subsequent processing
7470 alters any part of it. */
7475 complain);
7482 }
7484 /* Returns the type which will really be used for passing an argument of
7485 type TYPE. */
7487 tree
7489 {
7490 /* Pass classes with copy ctors by invisible reference. */
7492 {
7494 /* There are no other pointers to this temporary. */
7496 }
7504 }
7506 /* Actually perform the appropriate conversion. */
7508 tree
7510 {
7511 tree bitfield_type;
7513 /* If VAL is a bitfield, then -- since it has already been converted
7514 to TYPE -- it cannot have a precision greater than TYPE.
7516 If it has a smaller precision, we must widen it here. For
7517 example, passing "int f:3;" to a function expecting an "int" will
7518 not result in any conversion before this point.
7520 If the precision is the same we must not risk widening. For
7521 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
7522 often have type "int", even though the C++ type for the field is
7523 "long long". If the value is being passed to a function
7524 expecting an "int", then no conversions will be required. But,
7525 if we call convert_bitfield_to_declared_type, the bitfield will
7526 be converted to "long long". */
7533 ;
7534 /* Pass classes with copy ctors by invisible reference. */
7543 {
7545 {
7553 "argument of function call might be a candidate "
7555 }
7557 }
7559 }
7561 /* Returns non-zero iff FN is a function with magic varargs, i.e. ones for
7562 which just decay_conversion or no conversions at all should be done.
7563 This is true for some builtins which don't act like normal functions.
7564 Return 2 if no conversions at all should be done, 1 if just
7565 decay_conversion. Return 3 for special treatment of the 3rd argument
7566 for __builtin_*_overflow_p. */
7568 int
7570 {
7573 {
7588 }
7591 }
7593 /* Returns the decl of the dispatcher function if FN is a function version. */
7595 tree
7597 {
7607 {
7611 }
7616 }
7618 /* fn is a function version dispatcher that is marked used. Mark all the
7619 semantically identical function versions it will dispatch as used. */
7621 void
7623 {
7640 /* All semantically identical versions are chained. Traverse and mark each
7641 one of them as used. */
7644 {
7647 }
7648 }
7650 /* Build a call to "the copy constructor" for the type of A, even if it
7651 wouldn't be selected by normal overload resolution. Used for
7652 diagnostics. */
7654 static tree
7656 {
7667 }
7669 /* Return true iff T refers to a base field. */
7671 static bool
7673 {
7682 }
7684 /* We can't elide a copy from a function returning by value to a base
7685 subobject, as the callee might clobber tail padding. Return true iff this
7686 could be that case. */
7688 static bool
7690 {
7691 /* Copy elision only happens with a TARGET_EXPR. */
7695 /* It's safe to elide the copy for a class with no tail padding. */
7698 /* It's safe to elide the copy if we aren't initializing a base object. */
7702 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */
7706 {
7707 /* We'll end up copying from each of the arms of the COND_EXPR directly
7708 into the target, so look at them. */
7713 }
7716 }
7718 /* True iff C is a conversion that binds a reference to a prvalue. */
7720 static bool
7722 {
7739 }
7741 /* Call the trivial destructor for INSTANCE, which can be either an lvalue of
7742 class type or a pointer to class type. */
7744 tree
7746 {
7750 {
7751 no_clobber:
7753 }
7756 {
7760 }
7762 /* A trivial destructor should still clobber the object. */
7766 }
7768 /* Subroutine of the various build_*_call functions. Overload resolution
7769 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
7770 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
7771 bitmask of various LOOKUP_* flags which apply to the call itself. */
7773 static tree
7775 {
7783 tree val;
7792 /* In a template, there is no need to perform all of the work that
7793 is normally done. We are only interested in the type of the call
7794 expression, i.e., the return type of the function. Any semantic
7795 errors will be deferred until the template is instantiated. */
7797 {
7799 tree return_type;
7805 else
7806 /* Otherwise set TREE_USED for the benefit of -Wunused-function.
7807 See PR80598. */
7814 else
7815 {
7818 tree arg;
7826 }
7836 }
7838 /* Give any warnings we noticed during overload resolution. */
7840 {
7844 }
7846 /* Core issue 2327: P0135 doesn't say how to handle the case where the
7847 argument to the copy constructor ends up being a prvalue after
7848 conversion. Let's do the normal processing, but pretend we aren't
7849 actually using the copy constructor. */
7857 {
7860 }
7862 /* OK, we're actually calling this inherited constructor; set its deletedness
7863 appropriately. We can get away with doing this here because calling is
7864 the only way to refer to a constructor. */
7868 /* Make =delete work with SFINAE. */
7870 {
7874 }
7877 {
7878 tree access_fn;
7879 /* If FN is a template function, two cases must be considered.
7880 For example:
7882 struct A {
7883 protected:
7884 template <class T> void f();
7885 };
7886 template <class T> struct B {
7887 protected:
7888 void g();
7889 };
7890 struct C : A, B<int> {
7891 using A::f; // #1
7892 using B<int>::g; // #2
7893 };
7895 In case #1 where `A::f' is a member template, DECL_ACCESS is
7896 recorded in the primary template but not in its specialization.
7897 We check access of FN using its primary template.
7899 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
7900 because it is a member of class template B, DECL_ACCESS is
7901 recorded in the specialization `B<int>::g'. We cannot use its
7902 primary template because `B<T>::g' and `B<int>::g' may have
7903 different access. */
7907 else
7912 }
7914 /* If we're checking for implicit delete, don't bother with argument
7915 conversions. */
7917 {
7921 /* Reject bad conversions now. */
7923 /* else continue to get conversion error. */
7924 }
7926 not_really_used:
7928 /* N3276 magic doesn't apply to nested calls. */
7931 /* No-Cleanup doesn't apply to nested calls either. */
7935 /* Find maximum size of vector to hold converted arguments. */
7942 /* The implicit parameters to a constructor are not considered by overload
7943 resolution, and must be of the proper type. */
7945 {
7946 tree object_arg;
7948 {
7951 }
7952 else
7953 {
7956 }
7959 /* We should never try to call the abstract constructor. */
7963 {
7967 }
7970 {
7971 /* The implicit move specified in 15.8.3/3 fails "...if the type of
7972 the first parameter of the selected constructor is not an rvalue
7973 reference to the object's type (possibly cv-qualified)...." */
7980 }
7981 }
7982 /* Bypass access control for 'this' parameter. */
7984 {
7987 ? first_arg
7990 tree converted_arg;
7991 tree base_binfo;
7997 {
7999 {
8000 auto_diagnostic_group d;
8005 }
8006 else
8008 }
8010 /* See if the function member or the whole class type is declared
8011 final and the call can be devirtualized. */
8016 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
8017 X is called for an object that is not of type X, or of a type
8018 derived from X, the behavior is undefined.
8020 So we can assume that anything passed as 'this' is non-null, and
8021 optimize accordingly. */
8023 /* Convert to the base in which the function was declared. */
8026 arg,
8029 /* Check that the base class is accessible. */
8032 {
8037 else
8039 }
8040 /* If fn was found by a using declaration, the conversion path
8041 will be to the derived class, not the base declaring fn. We
8042 must convert from derived to base. */
8053 else
8057 }
8062 {
8069 /* If the argument is NULL and used to (implicitly) instantiate a
8070 template function (and bind one of the template arguments to
8071 the type of 'long int'), we don't want to warn about passing NULL
8072 to non-pointer argument.
8073 For example, if we have this template function:
8075 template<typename T> void func(T x) {}
8077 we want to warn (when -Wconversion is enabled) in this case:
8079 void foo() {
8080 func<int>(NULL);
8081 }
8083 but not in this case:
8085 void foo() {
8086 func(NULL);
8087 }
8088 */
8095 /* Warn about initializer_list deduction that isn't currently in the
8096 working draft. */
8098 && flag_deduce_init_list
8102 {
8115 {
8123 }
8124 }
8126 /* Set user_conv_p on the argument conversions, so rvalue/base handling
8127 knows not to allow any more UDCs. This needs to happen after we
8128 process cand->warnings. */
8137 arg_complain);
8142 else
8144 }
8146 /* Default arguments */
8148 {
8154 complain);
8158 }
8160 /* Ellipsis */
8163 {
8166 {
8167 /* Do no conversions for certain magic varargs. */
8171 }
8173 /* For other magic varargs only do decay_conversion. */
8178 {
8179 /* Avoid infinite recursion trying to call A(...). */
8181 /* Try to call the actual copy constructor for a good error. */
8184 }
8185 else
8190 }
8195 /* Avoid to do argument-transformation, if warnings for format, and for
8196 nonnull are disabled. Just in case that at least one of them is active
8197 the check_function_arguments function might warn about something. */
8201 || warn_format
8202 || warn_suggest_attribute_format
8204 {
8208 {
8209 /* For -Wformat undo the implicit passing by hidden reference
8210 done by convert_arg_to_ellipsis. */
8214 else
8216 }
8220 }
8223 {
8224 /* Check for passing ellipsis arguments to an inherited constructor. We
8225 could handle this by open-coding the inherited constructor rather than
8226 defining it, but let's not bother now. */
8230 {
8232 {
8236 }
8238 }
8240 /* A base constructor inheriting from a virtual base doesn't get the
8241 inherited arguments, just this and __vtt. */
8244 }
8246 /* Avoid actually calling copy constructors and copy assignment operators,
8247 if possible. */
8254 /* It's unsafe to elide the constructor when handling
8255 a noexcept-expression, it may evaluate to the wrong
8256 value (c++/53025). */
8258 {
8259 tree targ;
8261 tree fa;
8264 /* Pull out the real argument, disregarding const-correctness. */
8266 /* Strip the reference binding for the constructor parameter. */
8270 /* But don't strip any other reference bindings; binding a temporary to a
8271 reference prevents copy elision. */
8277 {
8282 }
8283 else
8288 else
8291 /* In C++17 we shouldn't be copying a TARGET_EXPR except into a base
8292 subobject. */
8295 || force_elide
8296 /* It's from binding the ref parm to a packed field. */
8299 /* See unsafe_copy_elision_p. */
8306 /* [class.copy]: the copy constructor is implicitly defined even if the
8307 implementation elided its use. But don't warn about deprecation when
8308 eliding a temporary, as then no copy is actually performed. */
8313 {
8317 }
8318 else
8321 /* If we're creating a temp and we already have one, don't create a
8322 new one. If we're not creating a temp but we get one, use
8323 INIT_EXPR to collapse the temp into our target. Otherwise, if the
8324 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
8325 temp or an INIT_EXPR otherwise. */
8327 {
8332 }
8335 {
8340 }
8341 }
8345 {
8346 tree to = cp_stabilize_reference
8354 {
8355 /* Avoid copying empty classes. */
8358 }
8360 {
8364 "assignment from temporary initializer_list does not "
8368 }
8369 else
8370 {
8371 /* We must only copy the non-tail padding parts. */
8379 build_index_type
8388 }
8393 }
8395 {
8399 {
8402 no_cleanup_complain);
8403 else
8405 }
8406 }
8414 /* Warn if the built-in writes to an object of a non-trivial type. */
8421 {
8422 tree t;
8429 complain);
8435 }
8436 else
8437 {
8441 }
8447 {
8449 /* build_new_op_1 will clear this when appropriate. */
8451 }
8453 {
8457 }
8459 }
8461 namespace
8462 {
8464 /* Return the DECL of the first non-static subobject of class TYPE
8465 that satisfies the predicate PRED or null if none can be found. */
8468 tree
8470 {
8475 {
8482 }
8488 {
8494 }
8497 }
8499 struct NonPublicField
8500 {
8502 {
8504 }
8505 };
8507 /* Return the DECL of the first non-public subobject of class TYPE
8508 or null if none can be found. */
8512 {
8514 }
8516 struct NonTrivialField
8517 {
8519 {
8521 }
8522 };
8524 /* Return the DECL of the first non-trivial subobject of class TYPE
8525 or null if none can be found. */
8529 {
8531 }
8535 /* Return true if all copy and move assignment operator overloads for
8536 class TYPE are trivial and at least one of them is not deleted and,
8537 when ACCESS is set, accessible. Return false otherwise. Set
8538 HASASSIGN to true when the TYPE has a (not necessarily trivial)
8539 copy or move assignment. */
8541 static bool
8543 {
8547 /* Iterate over overloads of the assignment operator, checking
8548 accessible copy assignments for triviality. */
8551 {
8554 /* Skip operators that aren't copy assignments. */
8561 /* Skip template assignment operators and deleted functions. */
8571 /* Break early when both properties have been determined. */
8574 }
8576 /* Return true if they're all trivial and one of the expressions
8577 TYPE() = TYPE() or TYPE() = (TYPE&)() is valid. */
8582 }
8584 /* Return true if all copy and move ctor overloads for class TYPE are
8585 trivial and at least one of them is not deleted and, when ACCESS is
8586 set, accessible. Return false otherwise. Set each element of HASCTOR[]
8587 to true when the TYPE has a (not necessarily trivial) default and copy
8588 (or move) ctor, respectively. */
8590 static bool
8592 {
8597 {
8600 /* Skip template constructors. */
8606 /* Skip ctors other than default, copy, and move. */
8622 /* Break early when both properties have been determined. */
8625 }
8628 }
8630 /* Issue a warning on a call to the built-in function FNDECL if it is
8631 a raw memory write whose destination is not an object of (something
8632 like) trivial or standard layout type with a non-deleted assignment
8633 and copy ctor. Detects const correctness violations, corrupting
8634 references, virtual table pointers, and bypassing non-trivial
8635 assignments. */
8637 static void
8640 {
8641 /* Except for bcopy where it's second, the destination pointer is
8642 the first argument for all functions handled here. Compute
8643 the index of the destination and source arguments. */
8653 /* Determine the type of the pointed-to object and whether it's
8654 a complete class type. */
8660 /* Check to see if the raw memory call is made by a non-static member
8661 function with THIS as the destination argument for the destination
8662 type. If so, and if the class has no non-trivial bases or members,
8663 be more permissive. */
8667 {
8676 }
8678 /* True if the class is trivial. */
8681 /* Set to true if DESTYPE has an accessible copy assignment. */
8683 /* True if all of the class' overloaded copy assignment operators
8684 are all trivial (and not deleted) and at least one of them is
8685 accessible. */
8688 /* Set to true if DESTTYPE has an accessible default and copy ctor,
8689 respectively. */
8692 /* True if all of the class' overloaded copy constructors are all
8693 trivial (and not deleted) and at least one of them is accessible. */
8696 /* Set FLD to the first private/protected member of the class. */
8699 /* The warning format string. */
8701 /* A suggested alternative to offer instead of the raw memory call.
8702 Empty string when none can be come up with. */
8707 {
8710 {
8711 /* Diagnose setting non-copy-assignable or non-trivial types,
8712 or types with a private member, to (potentially) non-zero
8713 bytes. Since the value of the bytes being written is unknown,
8714 suggest using assignment instead (if one exists). Also warn
8715 for writes into objects for which zero-initialization doesn't
8716 mean all bits clear (pointer-to-member data, where null is all
8717 bits set). Since the value being written is (most likely)
8718 non-zero, simply suggest assignment (but not copy assignment). */
8726 {
8729 "%qD writing to an object of type %#qT with "
8732 }
8738 }
8739 /* Fall through. */
8742 /* Similarly to the above, diagnose clearing non-trivial or non-
8743 standard layout objects, or objects of types with no assignmenmt.
8744 Since the value being written is known to be zero, suggest either
8745 copy assignment, copy ctor, or default ctor as an alternative,
8746 depending on what's available. */
8769 /* Determine the type of the source object. */
8773 else
8776 /* Since it's impossible to determine wheter the byte copy is
8777 being used in place of assignment to an existing object or
8778 as a substitute for initialization, assume it's the former.
8779 Determine the best alternative to use instead depending on
8780 what's not deleted. */
8801 srctype))
8802 {
8803 /* Warn when copying into a non-trivial object from an object
8804 of a different type other than void or char. */
8806 "%qD copying an object of non-trivial type "
8809 }
8814 srctype))
8815 {
8818 "%qD copying an object of type %#qT with "
8819 "%qs member %qD from an array of %#qT; use "
8822 }
8824 {
8829 /* Finally, warn on partial copies. */
8830 unsigned HOST_WIDE_INT typesize
8836 "a non-trivial type %#qT leaves %wu "
8839 "a non-trivial type %#qT leaves %wu "
8842 }
8857 {
8861 /* Finally, warn on reallocation into insufficient space. */
8863 "%qD moving an object of non-trivial type "
8866 sz);
8867 }
8872 }
8875 {
8879 else
8882 }
8886 }
8888 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
8889 This function performs no overload resolution, conversion, or other
8890 high-level operations. */
8892 tree
8894 tsubst_flags_t complain)
8895 {
8896 tree fndecl;
8898 /* Remember roughly where this call is. */
8905 /* Check that arguments to builtin functions match the expectations. */
8907 && !processing_template_decl
8909 {
8912 /* We need to take care that values to BUILT_IN_NORMAL
8913 are reduced. */
8920 }
8925 /* 5.2.2/11: If a function call is a prvalue of object type: if the
8926 function call is either the operand of a decltype-specifier or the
8927 right operand of a comma operator that is the operand of a
8928 decltype-specifier, a temporary object is not introduced for the
8929 prvalue. The type of the prvalue may be incomplete. */
8931 {
8937 {
8940 }
8941 }
8943 }
8945 /* Returns the value to use for the in-charge parameter when making a
8946 call to a function with the indicated NAME.
8948 FIXME:Can't we find a neater way to do this mapping? */
8950 tree
8952 {
8954 {
8958 }
8959 else
8960 {
8966 }
8969 }
8971 /* We've built up a constructor call RET. Complain if it delegates to the
8972 constructor we're currently compiling. */
8974 static void
8976 {
8982 }
8984 /* Build a call to a constructor, destructor, or an assignment
8985 operator for INSTANCE, an expression with class type. NAME
8986 indicates the special member function to call; *ARGS are the
8987 arguments. ARGS may be NULL. This may change ARGS. BINFO
8988 indicates the base of INSTANCE that is to be passed as the `this'
8989 parameter to the member function called.
8991 FLAGS are the LOOKUP_* flags to use when processing the call.
8993 If NAME indicates a complete object constructor, INSTANCE may be
8994 NULL_TREE. In this case, the caller will call build_cplus_new to
8995 store the newly constructed object into a VAR_DECL. */
8997 tree
9000 {
9001 tree fns;
9002 /* The type of the subobject to be constructed or destroyed. */
9003 tree class_type;
9005 tree ret;
9013 {
9016 /* Shortcut to avoid lazy destructor declaration. */
9018 }
9021 {
9022 /* Resolve the name. */
9027 }
9033 /* Handle the special case where INSTANCE is NULL_TREE. */
9036 else
9037 {
9038 /* Convert to the base class, if necessary. */
9041 {
9043 /* For constructors and destructors, either the base is
9044 non-virtual, or it is virtual but we are doing the
9045 conversion from a constructor or destructor for the
9046 complete object. In either case, we can convert
9047 statically. */
9049 else
9050 {
9051 /* However, for assignment operators, we must convert
9052 dynamically if the base is virtual. */
9056 }
9057 }
9058 }
9062 /* In C++17, "If the initializer expression is a prvalue and the
9063 cv-unqualified version of the source type is the same class as the class
9064 of the destination, the initializer expression is used to initialize the
9065 destination object." Handle that here to avoid doing overload
9066 resolution. */
9070 {
9080 && (same_type_ignoring_top_level_qualifiers_p
9082 {
9091 /* Avoid change of behavior on Wunused-var-2.C. */
9094 }
9095 }
9099 /* When making a call to a constructor or destructor for a subobject
9100 that uses virtual base classes, pass down a pointer to a VTT for
9101 the subobject. */
9105 {
9106 tree vtt;
9107 tree sub_vtt;
9109 /* If the current function is a complete object constructor
9110 or destructor, then we fetch the VTT directly.
9111 Otherwise, we look it up using the VTT we were given. */
9119 else
9123 {
9126 }
9129 }
9134 complain);
9145 }
9147 /* Return the NAME, as a C string. The NAME indicates a function that
9148 is a member of TYPE. *FREE_P is set to true if the caller must
9149 free the memory returned.
9151 Rather than go through all of this, we should simply set the names
9152 of constructors and destructors appropriately, and dispense with
9153 ctor_identifier, dtor_identifier, etc. */
9157 {
9160 /* Assume that we will not allocate memory. */
9162 /* Constructors and destructors are special. */
9164 {
9165 pretty_name
9167 /* For a destructor, add the '~'. */
9169 {
9171 /* Remember that we need to free the memory allocated. */
9173 }
9174 }
9176 {
9179 TFF_PLAIN_IDENTIFIER),
9180 NULL);
9181 /* Remember that we need to free the memory allocated. */
9183 }
9184 else
9188 }
9190 /* If CANDIDATES contains exactly one candidate, return it, otherwise
9191 return NULL. */
9195 {
9203 }
9205 /* If CANDIDATE is invalid due to a bad argument type, return the
9206 pertinent conversion_info.
9208 Otherwise, return NULL. */
9212 {
9213 /* Must be an rr_arg_conversion or rr_bad_arg_conversion. */
9220 {
9229 }
9230 }
9232 /* Issue an error and note complaining about a bad argument type at a
9233 callsite with a single candidate FNDECL.
9235 ARG_LOC is the location of the argument (or UNKNOWN_LOCATION, in which
9236 case input_location is used).
9237 FROM_TYPE is the type of the actual argument; TO_TYPE is the type of
9238 the formal parameter. */
9240 void
9244 {
9245 auto_diagnostic_group d;
9249 {
9252 }
9259 }
9261 /* Subroutine of build_new_method_call_1, for where there are no viable
9262 candidates for the call. */
9264 static void
9267 tree explicit_targs,
9268 tree basetype,
9272 {
9273 auto_diagnostic_group d;
9280 else
9281 {
9282 /* Special-case for when there's a single candidate that's failing
9283 due to a bad argument type. */
9287 {
9292 }
9298 {
9301 }
9309 }
9311 }
9313 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
9314 be set, upon return, to the function called. ARGS may be NULL.
9315 This may change ARGS. */
9317 static tree
9321 {
9326 tree optype;
9328 tree name;
9331 tree call;
9332 tree fn;
9335 tree orig_instance;
9336 tree orig_fns;
9342 /* We don't know what function we're going to call, yet. */
9351 {
9355 }
9360 /* Dismantle the baselink to collect all the information we need. */
9368 {
9372 }
9383 /* Under DR 147 A::A() is an invalid constructor call,
9384 not a functional cast. */
9386 {
9392 auto_diagnostic_group d;
9399 complain);
9401 }
9404 {
9409 }
9411 /* Process the argument list. */
9413 {
9418 }
9420 /* Consider the object argument to be used even if we end up selecting a
9421 static member function. */
9424 /* Figure out whether to skip the first argument for the error
9425 message we will display to users if an error occurs. We don't
9426 want to display any compiler-generated arguments. The "this"
9427 pointer hasn't been added yet. However, we must remove the VTT
9428 pointer if this is a call to a base-class constructor or
9429 destructor. */
9432 {
9433 /* Callers should explicitly indicate whether they want to ctor
9434 the complete object or just the part without virtual bases. */
9437 /* Remove the VTT pointer, if present. */
9442 /* It's OK to call destructors and constructors on cv-qualified
9443 objects. Therefore, convert the INSTANCE to the unqualified
9444 type, if necessary. */
9446 {
9450 }
9451 }
9452 else
9455 /* For the overload resolution we need to find the actual `this`
9456 that would be captured if the call turns out to be to a
9457 non-static member function. Do not actually capture it at this
9458 point. */
9460 /* Constructors don't use the enclosing 'this'. */
9462 else
9465 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9468 /* The number of arguments artificial parms in ARGS; we subtract one because
9469 there's no 'this' in ARGS. */
9472 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
9473 initializer, not T({ }). */
9477 {
9484 /* If the initializer list has no elements and T is a class type with
9485 a default constructor, the object is value-initialized. Handle
9486 this here so we don't need to handle it wherever we use
9487 build_special_member_call. */
9490 /* For a user-provided default constructor, use the normal
9491 mechanisms so that protected access works. */
9496 /* If BASETYPE is an aggregate, we need to do aggregate
9497 initialization. */
9499 {
9502 }
9505 {
9511 }
9513 /* Otherwise go ahead with overload resolution. */
9518 }
9519 else
9528 {
9533 skip_first_for_error,
9534 user_args);
9536 }
9537 else
9538 {
9541 {
9544 tree arglist;
9547 {
9552 auto_diagnostic_group d;
9556 else
9562 }
9564 }
9565 else
9566 {
9574 {
9575 /* This is not an error, it is runtime undefined
9576 behavior. */
9585 fn);
9586 }
9591 {
9596 {
9597 /* We captured 'this' in the current lambda now that
9598 we know we really need it. */
9600 }
9602 /* We can't tell until instantiation time whether we can use
9604 else
9605 {
9608 fn);
9610 }
9611 }
9614 {
9615 /* Optimize away vtable lookup if we know that this
9616 function can't be overridden. We need to check if
9617 the context and the type where we found fn are the same,
9618 actually FN might be defined in a different class
9619 type because of a using-declaration. In this case, we
9620 do not want to perform a non-virtual call. */
9622 && same_type_ignoring_top_level_qualifiers_p
9628 /* Now we know what function is being called. */
9631 /* Build the actual CALL_EXPR. */
9633 /* In an expression of the form `a->f()' where `f' turns
9634 out to be a static member function, `a' is
9635 none-the-less evaluated. */
9639 {
9640 /* But avoid the implicit lvalue-rvalue conversion when 'a'
9641 is volatile. */
9646 }
9650 /* An explicit call of the form "x->~X()" has type
9651 "void". However, on platforms where destructors
9652 return "this" (i.e., those where
9653 targetm.cxx.cdtor_returns_this is true), such calls
9654 will appear to have a return value of pointer type
9655 to the low-level call machinery. We do not want to
9656 change the low-level machinery, since we want to be
9657 able to optimize "delete f()" on such platforms as
9658 "operator delete(~X(f()))" (rather than generating
9659 "t = f(), ~X(t), operator delete (t)"). */
9661 }
9662 }
9663 }
9666 {
9672 {
9675 }
9678 call = (build_min_non_dep_call_vec
9682 orig_args));
9687 }
9689 /* Free all the conversions we allocated. */
9696 }
9698 /* Wrapper for above. */
9700 tree
9704 {
9705 tree ret;
9711 }
9713 /* Returns true iff standard conversion sequence ICS1 is a proper
9714 subsequence of ICS2. */
9716 static bool
9718 {
9719 /* We can assume that a conversion of the same code
9720 between the same types indicates a subsequence since we only get
9721 here if the types we are converting from are the same. */
9728 {
9738 /* At this point, ICS1 cannot be a proper subsequence of
9739 ICS2. We can get a USER_CONV when we are comparing the
9740 second standard conversion sequence of two user conversion
9741 sequences. */
9756 }
9757 }
9759 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
9760 be any _TYPE nodes. */
9762 bool
9764 {
9768 /* We only allow proper derivation here. The DERIVED_FROM_P macro
9769 considers every class derived from itself. */
9772 }
9774 /* We build the ICS for an implicit object parameter as a pointer
9775 conversion sequence. However, such a sequence should be compared
9776 as if it were a reference conversion sequence. If ICS is the
9777 implicit conversion sequence for an implicit object parameter,
9778 modify it accordingly. */
9780 static void
9782 {
9784 {
9785 /* [over.match.funcs]
9787 For non-static member functions, the type of the
9788 implicit object parameter is "reference to cv X"
9789 where X is the class of which the function is a
9790 member and cv is the cv-qualification on the member
9791 function declaration. */
9793 tree reference_type;
9795 /* The `this' parameter is a pointer to a class type. Make the
9796 implicit conversion talk about a reference to that same class
9797 type. */
9810 }
9811 }
9813 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
9814 and return the initial reference binding conversion. Otherwise,
9815 leave *ICS unchanged and return NULL. */
9819 {
9821 {
9826 }
9829 }
9831 /* Compare two implicit conversion sequences according to the rules set out in
9832 [over.ics.rank]. Return values:
9834 1: ics1 is better than ics2
9835 -1: ics2 is better than ics1
9836 0: ics1 and ics2 are indistinguishable */
9838 static int
9840 {
9841 tree from_type1;
9842 tree from_type2;
9843 tree to_type1;
9844 tree to_type2;
9851 /* REF_BINDING is nonzero if the result of the conversion sequence
9852 is a reference type. In that case REF_CONV is the reference
9853 binding conversion. */
9857 /* Compare badness before stripping the reference conversion. */
9863 /* Handle implicit object parameters. */
9867 /* Handle reference parameters. */
9871 /* List-initialization sequence L1 is a better conversion sequence than
9872 list-initialization sequence L2 if L1 converts to
9873 std::initializer_list<X> for some X and L2 does not. */
9879 /* [over.ics.rank]
9881 When comparing the basic forms of implicit conversion sequences (as
9882 defined in _over.best.ics_)
9884 --a standard conversion sequence (_over.ics.scs_) is a better
9885 conversion sequence than a user-defined conversion sequence
9886 or an ellipsis conversion sequence, and
9888 --a user-defined conversion sequence (_over.ics.user_) is a
9889 better conversion sequence than an ellipsis conversion sequence
9890 (_over.ics.ellipsis_). */
9891 /* Use BAD_CONVERSION_RANK because we already checked for a badness
9892 mismatch. If both ICS are bad, we try to make a decision based on
9893 what would have happened if they'd been good. This is not an
9894 extension, we'll still give an error when we build up the call; this
9895 just helps us give a more helpful error message. */
9905 /* Both conversions are ellipsis conversions. */
9908 /* User-defined conversion sequence U1 is a better conversion sequence
9909 than another user-defined conversion sequence U2 if they contain the
9910 same user-defined conversion operator or constructor and if the sec-
9911 ond standard conversion sequence of U1 is better than the second
9912 standard conversion sequence of U2. */
9914 /* Handle list-conversion with the same code even though it isn't always
9915 ranked as a user-defined conversion and it doesn't have a second
9916 standard conversion sequence; it will still have the desired effect.
9917 Specifically, we need to do the reference binding comparison at the
9918 end of this function. */
9921 {
9937 {
9942 }
9943 else
9944 {
9945 /* For ambiguous or aggregate conversions, use the target type as
9946 a proxy for the conversion function. */
9949 }
9951 /* We can just fall through here, after setting up
9952 FROM_TYPE1 and FROM_TYPE2. */
9955 }
9956 else
9957 {
9961 /* We're dealing with two standard conversion sequences.
9963 [over.ics.rank]
9965 Standard conversion sequence S1 is a better conversion
9966 sequence than standard conversion sequence S2 if
9968 --S1 is a proper subsequence of S2 (comparing the conversion
9969 sequences in the canonical form defined by _over.ics.scs_,
9970 excluding any Lvalue Transformation; the identity
9971 conversion sequence is considered to be a subsequence of
9972 any non-identity conversion sequence */
9983 }
9985 /* One sequence can only be a subsequence of the other if they start with
9986 the same type. They can start with different types when comparing the
9987 second standard conversion sequence in two user-defined conversion
9988 sequences. */
9990 {
9995 }
9997 /* [over.ics.rank]
9999 Or, if not that,
10001 --the rank of S1 is better than the rank of S2 (by the rules
10002 defined below):
10004 Standard conversion sequences are ordered by their ranks: an Exact
10005 Match is a better conversion than a Promotion, which is a better
10006 conversion than a Conversion.
10008 Two conversion sequences with the same rank are indistinguishable
10009 unless one of the following rules applies:
10011 --A conversion that does not a convert a pointer, pointer to member,
10012 or std::nullptr_t to bool is better than one that does.
10014 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
10015 so that we do not have to check it explicitly. */
10024 /* A conversion from scalar arithmetic type to complex is worse than a
10025 conversion between scalar arithmetic types. */
10032 {
10035 else
10037 }
10043 {
10048 }
10049 /* The rules for pointers to members A::* are just like the rules
10050 for pointers A*, except opposite: if B is derived from A then
10051 A::* converts to B::*, not vice versa. For that reason, we
10052 switch the from_ and to_ variables here. */
10059 {
10064 }
10069 {
10070 /* This was one of the pointer or pointer-like conversions.
10072 [over.ics.rank]
10074 --If class B is derived directly or indirectly from class A,
10075 conversion of B* to A* is better than conversion of B* to
10076 void*, and conversion of A* to void* is better than
10077 conversion of B* to void*. */
10080 {
10082 deref_from_type2))
10085 deref_from_type1))
10087 }
10090 {
10092 {
10094 {
10096 deref_to_type1))
10098 }
10099 /* We know that DEREF_TO_TYPE1 is `void' here. */
10101 deref_to_type2))
10103 }
10104 }
10107 {
10108 /* [over.ics.rank]
10110 --If class B is derived directly or indirectly from class A
10111 and class C is derived directly or indirectly from B,
10113 --conversion of C* to B* is better than conversion of C* to
10114 A*,
10116 --conversion of B* to A* is better than conversion of C* to
10117 A* */
10119 {
10121 deref_to_type2))
10124 deref_to_type1))
10126 }
10128 {
10130 deref_from_type1))
10133 deref_from_type2))
10135 }
10136 }
10137 }
10140 {
10143 /* [over.ics.rank]
10145 --binding of an expression of type C to a reference of type
10146 B& is better than binding an expression of type C to a
10147 reference of type A&
10149 --conversion of C to B is better than conversion of C to A, */
10152 {
10157 }
10158 }
10161 {
10164 /* [over.ics.rank]
10166 --binding of an expression of type B to a reference of type
10167 A& is better than binding an expression of type C to a
10168 reference of type A&,
10170 --conversion of B to A is better than conversion of C to A */
10173 {
10178 }
10179 }
10181 /* [over.ics.rank]
10183 --S1 and S2 differ only in their qualification conversion and yield
10184 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
10185 qualification signature of type T1 is a proper subset of the cv-
10186 qualification signature of type T2 */
10190 {
10194 }
10196 /* [over.ics.rank]
10198 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
10199 to an implicit object parameter of a non-static member function
10200 declared without a ref-qualifier, and either S1 binds an lvalue
10201 reference to an lvalue and S2 binds an rvalue reference or S1 binds an
10202 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x
10203 draft standard, 13.3.3.2)
10205 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
10206 types to which the references refer are the same type except for
10207 top-level cv-qualifiers, and the type to which the reference
10208 initialized by S2 refers is more cv-qualified than the type to
10209 which the reference initialized by S1 refers.
10211 DR 1328 [over.match.best]: the context is an initialization by
10212 conversion function for direct reference binding (13.3.1.6) of a
10213 reference to function type, the return type of F1 is the same kind of
10214 reference (i.e. lvalue or rvalue) as the reference being initialized,
10215 and the return type of F2 is not. */
10218 {
10225 {
10229 /* Don't prefer a bad conversion that drops cv-quals to a bad
10230 conversion with the wrong rvalueness. */
10234 }
10237 {
10241 {
10242 /* Prefer the one that drops fewer cv-quals. */
10247 }
10249 }
10250 }
10252 /* Neither conversion sequence is better than the other. */
10254 }
10256 /* The source type for this standard conversion sequence. */
10258 static tree
10260 {
10262 {
10267 }
10269 }
10271 /* Note a warning about preferring WINNER to LOSER. We do this by storing
10272 a pointer to LOSER and re-running joust to produce the warning if WINNER
10273 is actually used. */
10275 static void
10277 {
10283 }
10285 /* Compare two candidates for overloading as described in
10286 [over.match.best]. Return values:
10288 1: cand1 is better than cand2
10289 -1: cand2 is better than cand1
10290 0: cand1 and cand2 are indistinguishable */
10292 static int
10294 tsubst_flags_t complain)
10295 {
10301 /* Candidates that involve bad conversions are always worse than those
10302 that don't. */
10308 /* If we have two pseudo-candidates for conversions to the same type,
10309 or two candidates for the same function, arbitrarily pick one. */
10314 /* Prefer a non-deleted function over an implicitly deleted move
10315 constructor or assignment operator. This differs slightly from the
10316 wording for issue 1402 (which says the move op is ignored by overload
10317 resolution), but this way produces better error messages. */
10321 {
10328 }
10330 /* a viable function F1
10331 is defined to be a better function than another viable function F2 if
10332 for all arguments i, ICSi(F1) is not a worse conversion sequence than
10333 ICSi(F2), and then */
10335 /* for some argument j, ICSj(F1) is a better conversion sequence than
10336 ICSj(F2) */
10338 /* For comparing static and non-static member functions, we ignore
10339 the implicit object parameter of the non-static function. The
10340 standard says to pretend that the static function has an object
10341 parm, but that won't work with operator overloading. */
10344 {
10350 /* We're comparing a near-match list constructor and a near-match
10351 non-list constructor. Just treat them as unordered. */
10358 else
10359 {
10362 }
10363 }
10366 {
10372 {
10374 && warn_sign_promo
10386 {
10393 else
10398 {
10402 }
10403 else
10405 }
10408 {
10411 }
10413 }
10414 }
10416 /* warn about confusing overload resolution for user-defined conversions,
10417 either between a constructor and a conversion op, or between two
10418 conversion ops. */
10423 {
10429 else
10432 /* We don't want to complain about `X::operator T1 ()'
10433 beating `X::operator T2 () const', when T2 is a no less
10434 cv-qualified version of T1. */
10437 {
10442 {
10445 }
10448 }
10449 else
10455 {
10459 auto_diagnostic_group d;
10463 {
10465 }
10466 }
10467 else
10469 }
10474 /* DR 495 moved this tiebreaker above the template ones. */
10475 /* or, if not that,
10476 the context is an initialization by user-defined conversion (see
10477 _dcl.init_ and _over.match.user_) and the standard conversion
10478 sequence from the return type of F1 to the destination type (i.e.,
10479 the type of the entity being initialized) is a better conversion
10480 sequence than the standard conversion sequence from the return type
10481 of F2 to the destination type. */
10484 {
10488 }
10490 /* or, if not that,
10491 F1 is a non-template function and F2 is a template function
10492 specialization. */
10499 /* or, if not that,
10500 F1 and F2 are template functions and the function template for F1 is
10501 more specialized than the template for F2 according to the partial
10502 ordering rules. */
10505 {
10506 winner = more_specialized_fn
10509 /* [temp.func.order]: The presence of unused ellipsis and default
10510 arguments has no effect on the partial ordering of function
10511 templates. add_function_candidate() will not have
10512 counted the "this" argument for constructors. */
10516 }
10518 // C++ Concepts
10519 // or, if not that, F1 is more constrained than F2.
10521 {
10525 }
10527 /* F1 is generated from a deduction-guide (13.3.1.8) and F2 is not */
10529 {
10531 /* We distinguish between candidates from an explicit deduction guide and
10532 candidates built from a constructor based on DECL_ARTIFICIAL. */
10539 {
10540 /* Prefer the special copy guide over a declared copy/move
10541 constructor. */
10547 /* Prefer a candidate generated from a non-template constructor. */
10552 }
10553 }
10555 /* F1 is a member of a class D, F2 is a member of a base class B of D, and
10556 for all arguments the corresponding parameters of F1 and F2 have the same
10557 type (CWG 2273/2277). */
10562 {
10576 {
10578 {
10583 }
10586 }
10587 }
10589 /* Check whether we can discard a builtin candidate, either because we
10590 have two identical ones or matching builtin and non-builtin candidates.
10592 (Pedantically in the latter case the builtin which matched the user
10593 function should not be added to the overload set, but we spot it here.
10595 [over.match.oper]
10596 ... the builtin candidates include ...
10597 - do not have the same parameter type list as any non-template
10598 non-member candidate. */
10601 {
10607 {
10609 /* Two built-in candidates; arbitrarily pick one. */
10612 /* cand1 is built-in; prefer cand2. */
10614 else
10615 /* cand2 is built-in; prefer cand1. */
10617 }
10618 }
10620 /* For candidates of a multi-versioned function, make the version with
10621 the highest priority win. This version will be checked for dispatching
10622 first. If this version can be inlined into the caller, the front-end
10623 will simply make a direct call to this function. */
10629 {
10635 /* Check if cand1->fn and cand2->fn are versions of the same function. It
10636 is possible that cand1->fn and cand2->fn are function versions but of
10637 different functions. Check types to see if they are versions of the same
10638 function. */
10641 {
10642 /* Always make the version with the higher priority, more
10643 specialized, win. */
10647 else
10649 }
10650 }
10652 /* If the two function declarations represent the same function (this can
10653 happen with declarations in multiple scopes and arg-dependent lookup),
10654 arbitrarily choose one. But first make sure the default args we're
10655 using match. */
10658 {
10665 {
10666 /* Don't crash if the fn is variadic. */
10671 }
10679 {
10682 {
10684 {
10686 {
10687 auto_diagnostic_group d;
10689 "default argument mismatch in "
10691 {
10696 }
10697 }
10698 else
10700 }
10701 else
10704 }
10707 }
10710 }
10712 tweak:
10714 /* Extension: If the worst conversion for one candidate is worse than the
10715 worst conversion for the other, take the first. */
10717 {
10722 {
10727 }
10733 {
10734 /* Don't choose a deleted function over ambiguity. */
10738 {
10739 auto_diagnostic_group d;
10741 "ISO C++ says that these are ambiguous, even "
10742 "though the worst conversion for the first is better than "
10746 }
10747 else
10750 }
10751 }
10755 }
10757 /* Given a list of candidates for overloading, find the best one, if any.
10758 This algorithm has a worst case of O(2n) (winner is last), and a best
10759 case of O(n/2) (totally ambiguous); much better than a sorting
10760 algorithm. */
10764 {
10769 /* Walk through the list once, comparing each current champ to the next
10770 candidate, knocking out a candidate or two with each comparison. */
10773 {
10777 else
10778 {
10780 {
10785 }
10786 else
10787 {
10790 }
10793 }
10794 }
10796 /* Make sure the champ is better than all the candidates it hasn't yet
10797 been compared to. */
10800 challenger != champ
10803 {
10807 }
10810 }
10812 /* Returns nonzero if things of type FROM can be converted to TO. */
10814 bool
10816 {
10818 /* implicit_conversion only considers user-defined conversions
10819 if it has an expression for the call argument list. */
10823 }
10825 /* Returns nonzero if things of type FROM can be converted to TO with a
10826 standard conversion. */
10828 bool
10830 {
10832 }
10834 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
10836 bool
10838 tsubst_flags_t complain)
10839 {
10844 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10846 /* We want to discard any access checks done for this test,
10847 as we might not be in the appropriate access context and
10848 we'll do the check again when we actually perform the
10849 conversion. */
10856 /* Discard the access checks now. */
10858 /* Free all the conversions we allocated. */
10862 }
10864 /* Like can_convert_arg, but allows dubious conversions as well. */
10866 bool
10868 tsubst_flags_t complain)
10869 {
10873 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10875 /* Try to perform the conversion. */
10878 /* Free all the conversions we allocated. */
10882 }
10884 /* Convert EXPR to TYPE. Return the converted expression.
10886 Note that we allow bad conversions here because by the time we get to
10887 this point we are committed to doing the conversion. If we end up
10888 doing a bad conversion, convert_like will complain. */
10890 tree
10893 {
10900 else
10906 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10914 {
10916 {
10917 /* If expr has unknown type, then it is an overloaded function.
10918 Call instantiate_type to get good error messages. */
10923 else
10924 {
10929 }
10930 }
10932 }
10934 {
10935 /* In a template, we are only concerned about determining the
10936 type of non-dependent expressions, so we do not have to
10937 perform the actual conversion. But for initializers, we
10938 need to be able to perform it at instantiation
10939 (or instantiate_non_dependent_expr) time. */
10943 }
10944 else
10947 /* Free all the conversions we allocated. */
10951 }
10953 tree
10955 {
10957 LOOKUP_IMPLICIT);
10958 }
10960 /* Convert EXPR to TYPE (as a direct-initialization) if that is
10961 permitted. If the conversion is valid, the converted expression is
10962 returned. Otherwise, NULL_TREE is returned, except in the case
10963 that TYPE is a class type; in that case, an error is issued. If
10964 C_CAST_P is true, then this direct-initialization is taking
10965 place as part of a static_cast being attempted as part of a C-style
10966 cast. */
10968 tree
10970 tree expr,
10972 tsubst_flags_t complain)
10973 {
10979 /* [dcl.init]
10981 If the destination type is a (possibly cv-qualified) class type:
10983 -- If the initialization is direct-initialization ...,
10984 constructors are considered. ... If no constructor applies, or
10985 the overload resolution is ambiguous, the initialization is
10986 ill-formed. */
10988 {
10994 }
10996 /* Get the high-water mark for the CONVERSION_OBSTACK. */
11000 c_cast_p,
11005 {
11006 /* In a template, we are only concerned about determining the
11007 type of non-dependent expressions, so we do not have to
11008 perform the actual conversion. But for initializers, we
11009 need to be able to perform it at instantiation
11010 (or instantiate_non_dependent_expr) time. */
11013 }
11014 else
11017 c_cast_p,
11018 complain);
11020 /* Free all the conversions we allocated. */
11024 }
11026 /* When initializing a reference that lasts longer than a full-expression,
11027 this special rule applies:
11029 [class.temporary]
11031 The temporary to which the reference is bound or the temporary
11032 that is the complete object to which the reference is bound
11033 persists for the lifetime of the reference.
11035 The temporaries created during the evaluation of the expression
11036 initializing the reference, except the temporary to which the
11037 reference is bound, are destroyed at the end of the
11038 full-expression in which they are created.
11040 In that case, we store the converted expression into a new
11041 VAR_DECL in a new scope.
11043 However, we want to be careful not to create temporaries when
11044 they are not required. For example, given:
11046 struct B {};
11047 struct D : public B {};
11048 D f();
11049 const B& b = f();
11051 there is no need to copy the return value from "f"; we can just
11052 extend its lifetime. Similarly, given:
11054 struct S {};
11055 struct T { operator S(); };
11056 T t;
11057 const S& s = t;
11059 we can extend the lifetime of the return value of the conversion
11060 operator.
11062 The next several functions are involved in this lifetime extension. */
11064 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The
11065 reference is being bound to a temporary. Create and return a new
11066 VAR_DECL with the indicated TYPE; this variable will store the value to
11067 which the reference is bound. */
11069 tree
11071 {
11074 /* Register the variable. */
11077 {
11078 /* Namespace-scope or local static; give it a mangled name. */
11079 /* FIXME share comdat with decl? */
11090 }
11091 else
11092 /* Create a new cleanup level if necessary. */
11096 }
11098 /* EXPR is the initializer for a variable DECL of reference or
11099 std::initializer_list type. Create, push and return a new VAR_DECL
11100 for the initializer so that it will live as long as DECL. Any
11101 cleanup for the new variable is returned through CLEANUP, and the
11102 code to initialize the new variable is returned through INITP. */
11104 static tree
11107 {
11108 tree init;
11109 tree type;
11110 tree var;
11112 /* Create the temporary variable. */
11116 /* If the rvalue is the result of a function call it will be
11117 a TARGET_EXPR. If it is some other construct (such as a
11118 member access expression where the underlying object is
11119 itself the result of a function call), turn it into a
11120 TARGET_EXPR here. It is important that EXPR be a
11121 TARGET_EXPR below since otherwise the INIT_EXPR will
11122 attempt to make a bitwise copy of EXPR to initialize
11123 VAR. */
11129 {
11133 }
11135 /* Recursively extend temps in this initializer. */
11139 /* Any reference temp has a non-trivial initializer. */
11142 /* If the initializer is constant, put it in DECL_INITIAL so we get
11143 static initialization and use in constant expressions. */
11145 /* As in store_init_value. */
11148 {
11150 {
11151 /* 5.19 says that a constant expression can include an
11152 lvalue-rvalue conversion applied to "a glvalue of literal type
11153 that refers to a non-volatile temporary object initialized
11154 with a constant expression". Rather than try to communicate
11155 that this VAR_DECL is a temporary, just mark it constexpr. */
11160 }
11163 }
11164 else
11165 /* Create the INIT_EXPR that will initialize the temporary
11166 variable. */
11169 {
11174 else
11175 {
11179 }
11181 /* We must be careful to destroy the temporary only
11182 after its initialization has taken place. If the
11183 initialization throws an exception, then the
11184 destructor should not be run. We cannot simply
11185 transform INIT into something like:
11187 (INIT, ({ CLEANUP_STMT; }))
11189 because emit_local_var always treats the
11190 initializer as a full-expression. Thus, the
11191 destructor would run too early; it would run at the
11192 end of initializing the reference variable, rather
11193 than at the end of the block enclosing the
11194 reference variable.
11196 The solution is to pass back a cleanup expression
11197 which the caller is responsible for attaching to
11198 the statement tree. */
11199 }
11200 else
11201 {
11204 {
11207 tls_aggregates);
11208 else
11210 static_aggregates);
11211 }
11212 else
11213 /* Check whether the dtor is callable. */
11215 }
11216 /* Avoid -Wunused-variable warning (c++/38958). */
11223 }
11225 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
11226 initializing a variable of that TYPE. */
11228 tree
11231 {
11239 /* Get the high-water mark for the CONVERSION_OBSTACK. */
11245 {
11247 {
11256 else
11260 }
11262 }
11265 /* Perform the conversion. */
11268 /* We gave an error in build_user_type_conversion_1. */
11270 else
11273 /* Free all the conversions we allocated. */
11277 }
11279 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer,
11280 which is bound either to a reference or a std::initializer_list. */
11282 static tree
11284 {
11289 {
11293 }
11296 /* Deal with binding to a subobject. */
11302 {
11310 }
11312 }
11314 /* INIT is part of the initializer for DECL. If there are any
11315 reference or initializer lists being initialized, extend their
11316 lifetime to match that of DECL. */
11318 tree
11320 {
11326 else
11327 {
11332 {
11334 {
11335 /* The temporary array underlying a std::initializer_list
11336 is handled like a reference temporary. */
11340 }
11341 else
11342 {
11348 }
11352 }
11353 }
11356 }
11358 /* Returns true iff an initializer for TYPE could contain temporaries that
11359 need to be extended because they are bound to references or
11360 std::initializer_list. */
11362 bool
11364 {
11369 {
11376 }
11378 }
11380 /* Returns true iff TYPE is some variant of std::initializer_list. */
11382 bool
11384 {
11389 /* Look through typedefs. */
11394 }
11396 /* Returns true iff DECL is a list constructor: i.e. a constructor which
11397 will accept an argument list of a single std::initializer_list<T>. */
11399 bool
11401 {
11403 tree arg;
11415 /* There are more non-defaulted parms. */
11419 }