| blob | b2ca667c8b42ca6cf75101293a8293bb2ddc5e5f |
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 }
3255 {
3258 ctype))
3259 {
3260 /* We're trying to produce a constructor with a prohibited signature,
3261 as discussed above; handle here any cases we didn't catch then,
3262 such as X(X<T>). */
3265 }
3266 }
3269 /* Aha, this is a conversion function. */
3272 else
3277 /* This situation can occur if a member template of a template
3278 class is specialized. Then, instantiate_template might return
3279 an instantiation of the specialization, in which case the
3280 DECL_TI_TEMPLATE field will point at the original
3281 specialization. For example:
3283 template <class T> struct S { template <class U> void f(U);
3284 template <> void f(int) {}; };
3285 S<double> sd;
3286 sd.f(3);
3288 Here, TMPL will be template <class U> S<double>::f(U).
3289 And, instantiate template will give us the specialization
3290 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
3291 for this will point at template <class T> template <> S<T>::f(int),
3292 so that we can find the definition. For the purposes of
3293 overload resolution, however, we want the original TMPL. */
3295 else
3300 fail:
3303 }
3312 {
3313 return
3318 }
3320 /* Create an overload candidate for the conversion function template TMPL,
3321 returning RETURN_TYPE, which will be invoked for expression OBJ to produce a
3322 pointer-to-function which will in turn be called with the argument list
3323 ARGLIST, and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
3324 passed on to implicit_conversion. */
3328 tree obj,
3332 {
3333 /* Making this work broke PR 71117 and 85118, so until the committee resolves
3334 core issue 2189, let's disable this candidate if there are any call
3335 operators. */
3339 return
3343 complain);
3344 }
3346 /* The CANDS are the set of candidates that were considered for
3347 overload resolution. Return the set of viable candidates, or CANDS
3348 if none are viable. If any of the candidates were viable, set
3349 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
3350 considered viable only if it is strictly viable. */
3356 {
3362 /* Be strict inside templates, since build_over_call won't actually
3363 do the conversions to get pedwarns. */
3373 {
3377 {
3378 /* Be strict in the presence of a viable candidate. Also if
3379 there are template candidates, so that we get deduction errors
3380 for them instead of silently preferring a bad conversion. */
3383 {
3384 /* Put any spliced near matches back onto the main list so
3385 that we see them if there is no strict match. */
3391 }
3392 }
3395 {
3403 }
3404 else
3406 }
3409 }
3411 static bool
3413 {
3418 }
3420 /* OBJ is being used in an expression like "OBJ.f (...)". In other
3421 words, it is about to become the "this" pointer for a member
3422 function call. Take the address of the object. */
3424 static tree
3426 {
3427 /* In a template, we are only concerned about the type of the
3428 expression, so we can take a shortcut. */
3433 }
3435 /* Returns true iff functions are equivalent. Equivalent functions are
3436 not '==' only if one is a function-local extern function or if
3437 both are extern "C". */
3441 {
3450 }
3452 /* Print information about a candidate FN being rejected due to INFO. */
3454 static void
3456 tree fn)
3457 {
3462 {
3463 /* Conversion of implicit `this' argument failed. */
3465 /* A bad conversion for 'this' must be discarding cv-quals. */
3468 from);
3469 else
3473 }
3475 {
3480 tf_warning_or_error);
3481 }
3483 /* Conversion of conversion function return value failed. */
3486 else
3487 {
3492 }
3493 }
3495 /* Print information about a candidate with WANT parameters and we found
3496 HAVE. */
3498 static void
3500 {
3505 }
3507 /* Print information about one overload candidate CANDIDATE. MSGSTR
3508 is the text to print before the candidate itself.
3510 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
3511 to have been run through gettext by the caller. This wart makes
3512 life simpler in print_z_candidates and for the translators. */
3514 static void
3517 {
3527 {
3538 else
3541 }
3548 else
3551 {
3554 }
3555 /* Give the user some information about why this candidate failed. */
3557 {
3561 {
3574 "cannot be converted to %qT with a qualification "
3580 "conversion function specialization to %qT is not an "
3585 /* We use template_unification_error_rejection if unification caused
3586 actual non-SFINAE errors, in which case we don't need to repeat
3587 them here. */
3589 {
3593 }
3594 /* Re-run template unification with diagnostics. */
3598 (make_tree_vec
3609 " a constructor taking a single argument of its own "
3613 {
3617 }
3621 "initialization from an expression of the same or derived "
3626 /* This candidate didn't have any issues or we failed to
3627 handle a particular code. Either way... */
3629 }
3630 }
3631 }
3633 static void
3635 {
3642 /* Remove non-viable deleted candidates. */
3645 {
3650 else
3652 }
3653 /* ...if there are any non-deleted ones. */
3657 /* There may be duplicates in the set of candidates. We put off
3658 checking this condition as long as possible, since we have no way
3659 to eliminate duplicates from a set of functions in less than n^2
3660 time. Now we are about to emit an error message, so it is more
3661 permissible to go slowly. */
3663 {
3665 /* Skip builtin candidates and conversion functions. */
3670 {
3674 else
3676 }
3677 }
3681 }
3683 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3684 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3685 the result of the conversion function to convert it to the final
3686 desired type. Merge the two sequences into a single sequence,
3687 and return the merged sequence. */
3691 {
3697 /* Find the end of the second conversion sequence. */
3699 {
3700 /* The entire sequence is a user-conversion sequence. */
3704 }
3707 /* We're binding a reference directly to the result of the conversion.
3708 build_user_type_conversion_1 stripped the REFERENCE_TYPE from the return
3709 type, but we want it back. */
3712 /* Replace the identity conversion with the user conversion
3713 sequence. */
3717 }
3719 /* Handle overload resolution for initializing an object of class type from
3720 an initializer list. First we look for a suitable constructor that
3721 takes a std::initializer_list; if we don't find one, we then look for a
3722 non-list constructor.
3724 Parameters are as for add_candidates, except that the arguments are in
3725 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and
3726 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3728 static void
3735 tsubst_flags_t complain)
3736 {
3739 /* We're looking for a ctor for list-initialization. */
3741 /* And we don't allow narrowing conversions. We also use this flag to
3742 avoid the copy constructor call for copy-list-initialization. */
3748 /* Always use the default constructor if the list is empty (DR 990). */
3751 ;
3752 /* If the class has a list ctor, try passing the list as a single
3753 argument first, but only consider list ctors. */
3755 {
3762 }
3764 /* Expand the CONSTRUCTOR into a new argument vec. */
3772 /* We aren't looking for list-ctors anymore. */
3774 /* We allow more user-defined conversions within an init-list. */
3780 }
3782 /* Returns the best overload candidate to perform the requested
3783 conversion. This function is used for three the overloading situations
3784 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3785 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as
3786 per [dcl.init.ref], so we ignore temporary bindings. */
3790 tsubst_flags_t complain)
3791 {
3793 tree fromtype;
3807 /* We represent conversion within a hierarchy using RVALUE_CONV and
3808 BASE_CONV, as specified by [over.best.ics]; these become plain
3809 constructor calls, as specified in [dcl.init]. */
3814 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid
3815 creating a garbage BASELINK; constructors can't be inherited. */
3819 {
3824 {
3825 /* [class.conv.fct] A conversion function is never used to
3826 convert a (possibly cv-qualified) object to the (possibly
3827 cv-qualified) same object type (or a reference to it), to a
3828 (possibly cv-qualified) base class of that type (or a
3829 reference to it)... */
3830 }
3831 else
3833 }
3840 /* It's OK to bind a temporary for converting constructor arguments, but
3841 not in converting the return value of a conversion operator. */
3847 {
3852 /* We should never try to call the abstract or base constructor
3853 from here. */
3859 {
3860 /* List-initialization. */
3864 }
3865 else
3866 {
3870 }
3873 {
3876 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3877 set, then this is copy-initialization. In that case, "The
3878 result of the call is then used to direct-initialize the
3879 object that is the destination of the copy-initialization."
3880 [dcl.init]
3882 We represent this in the conversion sequence with an
3883 rvalue conversion, which means a constructor call. */
3886 cand->second_conv
3888 }
3889 }
3892 {
3895 else
3897 }
3900 {
3904 /* If we are called to convert to a reference type, we are trying to
3905 find a direct binding, so don't even consider temporaries. If
3906 we don't find a direct binding, the caller will try again to
3907 look for a temporary binding. */
3918 {
3920 conversion *ics
3922 rettype,
3925 complain);
3927 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
3928 copy-initialization. In that case, "The result of the
3929 call is then used to direct-initialize the object that is
3930 the destination of the copy-initialization." [dcl.init]
3932 We represent this in the conversion sequence with an
3933 rvalue conversion, which means a constructor call. But
3934 don't add a second rvalue conversion if there's already
3935 one there. Which there really shouldn't be, but it's
3936 harmless since we'd add it here anyway. */
3944 {
3949 }
3952 {
3953 /* 13.3.1.5: For direct-initialization, those explicit
3954 conversion functions that are not hidden within S and
3955 yield type T or a type that can be converted to type T
3956 with a qualification conversion (4.4) are also candidate
3957 functions. */
3958 /* 13.3.1.6 doesn't have a parallel restriction, but it should;
3959 I've raised this issue with the committee. --jason 9/2011 */
3962 }
3964 {
3966 cand->reason
3970 }
3973 {
3974 /* 13.3.3.1.2: If the user-defined conversion is specified by
3975 a specialization of a conversion function template, the
3976 second standard conversion sequence shall have exact match
3977 rank. */
3980 }
3981 }
3982 }
3986 {
3990 }
3994 {
3996 {
3997 auto_diagnostic_group d;
4001 }
4010 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
4011 ambiguous conversion is no worse than another user-defined
4012 conversion. */
4015 }
4017 tree convtype;
4021 /* DR 5: [in the first step of copy-initialization]...if the function
4022 is a constructor, the call initializes a temporary of the
4023 cv-unqualified version of the destination type. */
4025 else
4027 /* Build the user conversion sequence. */
4028 conv = build_conv
4030 convtype,
4036 /* We're performing the maybe-rvalue overload resolution and
4037 a conversion function is in play. Reject converting the return
4038 value of the conversion function to a base class. */
4044 /* Remember that this was a list-initialization. */
4048 /* Combine it with the second conversion sequence. */
4053 }
4055 /* Wrapper for above. */
4057 tree
4059 tsubst_flags_t complain)
4060 {
4062 tree ret;
4068 {
4071 else
4072 {
4075 }
4076 }
4077 else
4082 }
4084 /* Subroutine of convert_nontype_argument.
4086 EXPR is an expression used in a context that requires a converted
4087 constant-expression, such as a template non-type parameter. Do any
4088 necessary conversions (that are permitted for converted
4089 constant-expressions) to convert it to the desired type.
4091 If conversion is successful, returns the converted expression;
4092 otherwise, returns error_mark_node. */
4094 tree
4096 {
4099 tree t;
4105 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4112 /* A converted constant expression of type T is an expression, implicitly
4113 converted to type T, where the converted expression is a constant
4114 expression and the implicit conversion sequence contains only
4116 * user-defined conversions,
4117 * lvalue-to-rvalue conversions (7.1),
4118 * array-to-pointer conversions (7.2),
4119 * function-to-pointer conversions (7.3),
4120 * qualification conversions (7.5),
4121 * integral promotions (7.6),
4122 * integral conversions (7.8) other than narrowing conversions (11.6.4),
4123 * null pointer conversions (7.11) from std::nullptr_t,
4124 * null member pointer conversions (7.12) from std::nullptr_t, and
4125 * function pointer conversions (7.13),
4127 and where the reference binding (if any) binds directly. */
4132 {
4134 {
4135 /* A conversion function is OK. If it isn't constexpr, we'll
4136 complain later that the argument isn't constant. */
4138 /* The lvalue-to-rvalue conversion is OK. */
4140 /* Array-to-pointer and function-to-pointer. */
4142 /* Function pointer conversions. */
4144 /* Qualification conversions. */
4150 {
4156 }
4166 /* Integral promotion or conversion. */
4169 /* Conversion from nullptr to pointer or pointer-to-member. */
4175 /* fall through. */
4180 }
4181 }
4183 /* Avoid confusing convert_nontype_argument by introducing
4184 a redundant conversion to the same reference type. */
4187 {
4191 }
4194 {
4198 }
4199 else
4200 {
4205 }
4207 /* Free all the conversions we allocated. */
4211 }
4213 /* Do any initial processing on the arguments to a function call. */
4217 {
4219 tree arg;
4222 {
4226 {
4230 }
4233 }
4235 }
4237 /* Perform overload resolution on FN, which is called with the ARGS.
4239 Return the candidate function selected by overload resolution, or
4240 NULL if the event that overload resolution failed. In the case
4241 that overload resolution fails, *CANDIDATES will be the set of
4242 candidates considered, and ANY_VIABLE_P will be set to true or
4243 false to indicate whether or not any of the candidates were
4244 viable.
4246 The ARGS should already have gone through RESOLVE_ARGS before this
4247 function is called. */
4254 {
4256 tree explicit_targs;
4267 /* Check FN. */
4274 {
4278 }
4280 /* Add the various candidate functions. */
4285 LOOKUP_NORMAL,
4291 else
4296 }
4298 /* Print an error message about being unable to build a call to FN with
4299 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
4300 be located; CANDIDATES is a possibly empty list of such
4301 functions. */
4303 static void
4306 {
4309 {
4312 }
4318 auto_diagnostic_group d;
4322 else
4327 }
4329 /* Return an expression for a call to FN (a namespace-scope function,
4330 or a static member function) with the ARGS. This may change
4331 ARGS. */
4333 tree
4335 tsubst_flags_t complain)
4336 {
4340 tree result;
4343 {
4347 }
4352 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4356 complain);
4359 {
4361 {
4362 // If there is a single (non-viable) function candidate,
4363 // let the error be diagnosed by cp_build_function_call_vec.
4368 // Otherwise, emit notes for non-viable candidates.
4370 }
4372 }
4373 else
4374 {
4376 /* If fn is template_id_expr, the call has explicit template arguments
4377 (e.g. func<int>(5)), communicate this info to build_over_call
4378 through flags so that later we can use it to decide whether to warn
4379 about peculiar null pointer conversion. */
4381 {
4382 /* If overload resolution selects a specialization of a
4383 function concept for non-dependent template arguments,
4384 the expression is true if the constraints are satisfied
4385 and false otherwise.
4387 NOTE: This is an extension of Concepts Lite TS that
4388 allows constraints to be used in expressions. */
4390 {
4396 }
4399 }
4402 }
4404 /* Free all the conversions we allocated. */
4408 }
4410 /* Build a call to a global operator new. FNNAME is the name of the
4411 operator (either "operator new" or "operator new[]") and ARGS are
4412 the arguments provided. This may change ARGS. *SIZE points to the
4413 total number of bytes required by the allocation, and is updated if
4414 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
4415 be used. If this function determines that no cookie should be
4416 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK
4417 is not NULL_TREE, it is evaluated before calculating the final
4418 array size, and if it fails, the array size is replaced with
4419 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN
4420 is non-NULL, it will be set, upon return, to the allocation
4421 function called. */
4423 tree
4428 {
4430 tree fns;
4437 /* Set to (size_t)-1 if the size check fails. */
4439 {
4445 }
4451 /* Based on:
4453 [expr.new]
4455 If this lookup fails to find the name, or if the allocated type
4456 is not a class type, the allocation function's name is looked
4457 up in the global scope.
4459 we disregard block-scope declarations of "operator new". */
4464 {
4471 /* If no aligned allocation function matches, try again without the
4472 alignment. */
4473 }
4475 /* Figure out what function is being called. */
4478 complain);
4480 /* If no suitable function could be found, issue an error message
4481 and give up. */
4483 {
4487 }
4489 /* If a cookie is required, add some extra space. Whether
4490 or not a cookie is required cannot be determined until
4491 after we know which function was called. */
4493 {
4495 tree arg_types;
4498 /* Skip the size_t parameter. */
4500 /* Check the remaining parameters (if any). */
4504 ptr_type_node))
4506 /* If we need a cookie, adjust the number of bytes allocated. */
4508 {
4509 /* Update the total size. */
4512 {
4513 /* Set to (size_t)-1 if the size check fails. */
4517 }
4518 /* Update the argument list to reflect the adjusted size. */
4520 }
4521 else
4523 }
4525 /* Tell our caller which function we decided to call. */
4529 /* Build the CALL_EXPR. */
4531 }
4533 /* Build a new call to operator(). This may change ARGS. */
4535 static tree
4537 {
4554 {
4556 /* It's no good looking for an overloaded operator() on a
4557 pointer-to-member-function. */
4561 }
4564 {
4568 }
4569 else
4573 {
4577 }
4579 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4583 {
4591 }
4596 {
4604 {
4611 add_template_conv_candidate
4615 else
4619 }
4620 }
4622 /* Be strict here because if we choose a bad conversion candidate, the
4623 errors we get won't mention the call context. */
4626 {
4628 {
4629 auto_diagnostic_group d;
4633 }
4635 }
4636 else
4637 {
4640 {
4642 {
4643 auto_diagnostic_group d;
4647 }
4649 }
4654 else
4655 {
4659 else
4660 {
4663 }
4666 }
4667 }
4669 /* Free all the conversions we allocated. */
4673 }
4675 /* Wrapper for above. */
4677 tree
4679 {
4680 tree ret;
4685 }
4687 /* Called by op_error to prepare format strings suitable for the error
4688 function. It concatenates a prefix (controlled by MATCH), ERRMSG,
4689 and a suffix (controlled by NTYPES). */
4693 {
4703 else
4707 }
4709 static void
4712 {
4717 {
4723 else
4735 else
4745 else
4756 else
4766 else
4771 else
4775 else
4780 }
4781 }
4783 /* Return the implicit conversion sequence that could be used to
4784 convert E1 to E2 in [expr.cond]. */
4788 {
4794 /* [expr.cond]
4796 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
4797 implicitly converted (clause _conv_) to the type "lvalue reference to
4798 T2", subject to the constraint that in the conversion the
4799 reference must bind directly (_dcl.init.ref_) to an lvalue.
4801 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
4802 implicitly converted to the type "rvalue reference to T2", subject to
4803 the constraint that the reference must bind directly. */
4805 {
4808 t1,
4809 e1,
4811 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND
4813 complain);
4816 }
4818 /* If E2 is a prvalue or if neither of the conversions above can be done
4819 and at least one of the operands has (possibly cv-qualified) class
4820 type: */
4824 /* [expr.cond]
4826 If E1 and E2 have class type, and the underlying class types are
4827 the same or one is a base class of the other: E1 can be converted
4828 to match E2 if the class of T2 is the same type as, or a base
4829 class of, the class of T1, and the cv-qualification of T2 is the
4830 same cv-qualification as, or a greater cv-qualification than, the
4831 cv-qualification of T1. If the conversion is applied, E1 is
4832 changed to an rvalue of type T2 that still refers to the original
4833 source class object (or the appropriate subobject thereof). */
4836 {
4838 {
4843 else
4846 }
4847 else
4849 }
4850 else
4851 /* [expr.cond]
4853 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
4854 converted to the type that expression E2 would have if E2 were
4855 converted to an rvalue (or the type it has, if E2 is an rvalue). */
4858 }
4860 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4861 arguments to the conditional expression. */
4863 static tree
4865 tsubst_flags_t complain)
4866 {
4867 tree arg2_type;
4868 tree arg3_type;
4877 /* As a G++ extension, the second argument to the conditional can be
4878 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
4879 c'.) If the second operand is omitted, make sure it is
4880 calculated only once. */
4882 {
4890 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
4893 else
4895 }
4897 /* If something has already gone wrong, just pass that fact up the
4898 tree. */
4908 {
4911 /* If arg1 is another cond_expr choosing between -1 and 0,
4912 then we can use its comparison. It may help to avoid
4913 additional comparison, produce more accurate diagnostics
4914 and enables folding. */
4924 /* force_rvalue can return error_mark on valid arguments. */
4935 {
4936 /* Rely on the error messages of the scalar version. */
4945 {
4953 }
4957 /* We could pass complain & tf_warning to unsafe_conversion_p,
4958 but the warnings (like Wsign-conversion) have already been
4959 given by the scalar build_conditional_expr_1. We still check
4960 unsafe_conversion_p to forbid truncating long long -> float. */
4962 {
4967 }
4969 {
4974 }
4984 }
4987 {
4993 {
4997 {
5003 }
5005 {
5011 }
5014 }
5015 }
5021 {
5024 "incompatible vector types in conditional expression: "
5028 }
5031 {
5034 }
5036 }
5038 /* [expr.cond]
5040 The first expression is implicitly converted to bool (clause
5041 _conv_). */
5043 LOOKUP_NORMAL);
5047 /* [expr.cond]
5049 If either the second or the third operand has type (possibly
5050 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
5051 array-to-pointer (_conv.array_), and function-to-pointer
5052 (_conv.func_) standard conversions are performed on the second
5053 and third operands. */
5057 {
5058 /* [expr.cond]
5060 One of the following shall hold:
5062 --The second or the third operand (but not both) is a
5063 throw-expression (_except.throw_); the result is of the type
5064 and value category of the other.
5066 --Both the second and the third operands have type void; the
5067 result is of type void and is a prvalue. */
5070 {
5073 }
5076 {
5079 }
5081 {
5084 }
5085 else
5086 {
5088 {
5091 "second operand to the conditional operator "
5092 "is of type %<void%>, but the third operand is "
5094 else
5096 "third operand to the conditional operator "
5097 "is of type %<void%>, but the second operand is "
5099 }
5101 }
5104 }
5105 /* [expr.cond]
5107 Otherwise, if the second and third operand have different types,
5108 and either has (possibly cv-qualified) class type, or if both are
5109 glvalues of the same value category and the same type except for
5110 cv-qualification, an attempt is made to convert each of those operands
5111 to the type of the other. */
5115 arg3_type)
5118 {
5123 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5129 /* [expr.cond]
5131 If both can be converted, or one can be converted but the
5132 conversion is ambiguous, the program is ill-formed. If
5133 neither can be converted, the operands are left unchanged and
5134 further checking is performed as described below. If exactly
5135 one conversion is possible, that conversion is applied to the
5136 chosen operand and the converted operand is used in place of
5137 the original operand for the remainder of this section. */
5142 {
5144 {
5151 else
5153 }
5155 }
5157 {
5161 /* Even if CONV2 is a valid conversion, the result of the
5162 conversion may be invalid. For example, if ARG3 has type
5163 "volatile X", and X does not have a copy constructor
5164 accepting a "volatile X&", then even if ARG2 can be
5165 converted to X, the conversion will fail. */
5169 }
5171 {
5178 }
5180 /* Free all the conversions we allocated. */
5186 /* If, after the conversion, both operands have class type,
5187 treat the cv-qualification of both operands as if it were the
5188 union of the cv-qualification of the operands.
5190 The standard is not clear about what to do in this
5191 circumstance. For example, if the first operand has type
5192 "const X" and the second operand has a user-defined
5193 conversion to "volatile X", what is the type of the second
5194 operand after this step? Making it be "const X" (matching
5195 the first operand) seems wrong, as that discards the
5196 qualification without actually performing a copy. Leaving it
5197 as "volatile X" seems wrong as that will result in the
5198 conditional expression failing altogether, even though,
5199 according to this step, the one operand could be converted to
5200 the type of the other. */
5208 }
5210 /* [expr.cond]
5212 If the second and third operands are glvalues of the same value
5213 category and have the same type, the result is of that type and
5214 value category. */
5218 {
5223 }
5225 /* [expr.cond]
5227 Otherwise, the result is an rvalue. If the second and third
5228 operand do not have the same type, and either has (possibly
5229 cv-qualified) class type, overload resolution is used to
5230 determine the conversions (if any) to be applied to the operands
5231 (_over.match.oper_, _over.built_). */
5235 {
5240 /* Rearrange the arguments so that add_builtin_candidate only has
5241 to know about two args. In build_builtin_candidate, the
5242 arguments are unscrambled. */
5247 COND_EXPR,
5248 NOP_EXPR,
5250 args,
5253 /* [expr.cond]
5255 If the overload resolution fails, the program is
5256 ill-formed. */
5259 {
5264 }
5267 {
5269 {
5270 auto_diagnostic_group d;
5273 }
5275 }
5277 /* [expr.cond]
5279 Otherwise, the conversions thus determined are applied, and
5280 the converted operands are used in place of the original
5281 operands for the remainder of this section. */
5290 }
5292 /* [expr.cond]
5294 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
5295 and function-to-pointer (_conv.func_) standard conversions are
5296 performed on the second and third operands.
5298 We need to force the lvalue-to-rvalue conversion here for class types,
5299 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
5300 that isn't wrapped with a TARGET_EXPR plays havoc with exception
5301 regions. */
5314 /* [expr.cond]
5316 After those conversions, one of the following shall hold:
5318 --The second and third operands have the same type; the result is of
5319 that type. */
5322 /* [expr.cond]
5324 --The second and third operands have arithmetic or enumeration
5325 type; the usual arithmetic conversions are performed to bring
5326 them to a common type, and the result is of that type. */
5331 {
5332 /* In this case, there is always a common type. */
5334 arg3_type);
5337 "implicit conversion from %qH to %qI to "
5339 loc);
5343 {
5347 /* Two enumerators from the same enumeration can have different
5353 }
5360 {
5364 }
5368 }
5369 /* [expr.cond]
5371 --The second and third operands have pointer type, or one has
5372 pointer type and the other is a null pointer constant; pointer
5373 conversions (_conv.ptr_) and qualification conversions
5374 (_conv.qual_) are performed to bring them to their composite
5375 pointer type (_expr.rel_). The result is of the composite
5376 pointer type.
5378 --The second and third operands have pointer to member type, or
5379 one has pointer to member type and the other is a null pointer
5380 constant; pointer to member conversions (_conv.mem_) and
5381 qualification conversions (_conv.qual_) are performed to bring
5382 them to a common type, whose cv-qualification shall match the
5383 cv-qualification of either the second or the third operand.
5384 The result is of the common type. */
5392 {
5395 complain);
5400 }
5403 {
5408 }
5413 valid_operands:
5415 {
5416 /* Let lvalue_kind know this was a glvalue. */
5419 }
5423 /* If the ARG2 and ARG3 are the same and don't have side-effects,
5424 warn here, because the COND_EXPR will be turned into ARG2. */
5431 /* We can't use result_type below, as fold might have returned a
5432 throw_expr. */
5435 {
5436 /* Expand both sides into the same slot, hopefully the target of
5437 the ?: expression. We used to check for TARGET_EXPRs here,
5438 but now we sometimes wrap them in NOP_EXPRs so the test would
5439 fail. */
5442 /* If this expression is an rvalue, but might be mistaken for an
5443 lvalue, we must add a NON_LVALUE_EXPR. */
5445 }
5446 else
5450 }
5452 /* Wrapper for above. */
5454 tree
5456 tsubst_flags_t complain)
5457 {
5458 tree ret;
5463 }
5465 /* OPERAND is an operand to an expression. Perform necessary steps
5466 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
5467 returned. */
5469 static tree
5471 {
5473 {
5476 /* Make sure the template type is instantiated now. */
5478 }
5481 }
5483 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
5484 OVERLOAD) to the CANDIDATES, returning an updated list of
5485 CANDIDATES. The ARGS are the arguments provided to the call;
5486 if FIRST_ARG is non-null it is the implicit object argument,
5487 otherwise the first element of ARGS is used if needed. The
5488 EXPLICIT_TARGS are explicit template arguments provided.
5489 TEMPLATE_ONLY is true if only template functions should be
5490 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
5491 add_function_candidate. */
5493 static void
5495 tree return_type,
5500 tsubst_flags_t complain)
5501 {
5502 tree ctype;
5506 unification_kind_t strict;
5511 /* Precalculate special handling of constructors and conversion ops. */
5514 {
5518 /* We're doing return_type(x). */
5520 else
5521 /* We're doing x.operator return_type(). */
5523 /* [over.match.funcs] For conversion functions, the function
5524 is considered to be a member of the class of the implicit
5525 object argument for the purpose of defining the type of
5526 the implicit object parameter. */
5528 }
5529 else
5530 {
5532 {
5534 /* For list-initialization we consider explicit constructors
5535 and complain if one is chosen. */
5536 check_converting
5539 }
5542 }
5546 else
5547 /* Delay creating the implicit this parameter until it is needed. */
5551 {
5563 {
5564 /* Figure out where the object arg comes from. If this
5565 function is a non-static member and we didn't get an
5566 implicit object argument, move it out of args. */
5568 {
5570 tree arg;
5577 }
5581 }
5585 fn,
5586 ctype,
5587 explicit_targs,
5588 fn_first_arg,
5589 fn_args,
5590 return_type,
5591 access_path,
5592 conversion_path,
5593 flags,
5594 strict,
5595 complain);
5598 fn,
5599 ctype,
5600 fn_first_arg,
5601 fn_args,
5602 access_path,
5603 conversion_path,
5604 flags,
5605 NULL,
5606 complain);
5607 }
5608 }
5610 /* Returns 1 if P0145R2 says that the LHS of operator CODE is evaluated first,
5611 -1 if the RHS is evaluated first, or 0 if the order is unspecified. */
5613 static int
5615 {
5617 {
5618 // 5. b @= a
5622 // 6. a[b]
5626 // 1. a.b
5627 // Not overloadable (yet).
5628 // 2. a->b
5629 // Only one argument.
5630 // 3. a->*b
5632 // 7. a << b
5634 // 8. a >> b
5640 }
5641 }
5643 static tree
5646 {
5667 {
5670 }
5677 {
5682 /* Use build_op_new_call and build_op_delete_call instead. */
5686 /* Use build_op_call instead. */
5693 /* These are saved for the sake of warn_logical_operator. */
5703 /* These are saved for the sake of maybe_warn_bool_compare. */
5708 /* =, ->, [], () must be non-static member functions. */
5712 /* FALLTHRU */
5720 }
5726 /* Use build_conditional_expr instead. */
5742 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5745 /* Add namespace-scope operators to the list of functions to
5746 consider. */
5748 {
5754 }
5760 /* Add class-member operators to the candidate set. */
5762 {
5763 tree fns;
5767 {
5770 }
5778 }
5779 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then
5780 only non-member functions that have type T1 or reference to
5781 cv-qualified-opt T1 for the first argument, if the first argument
5782 has an enumeration type, or T2 or reference to cv-qualified-opt
5783 T2 for the second argument, if the second argument has an
5784 enumeration type. Filter out those that don't match. */
5786 {
5790 {
5800 {
5806 && (same_type_ignoring_top_level_qualifiers_p
5811 }
5813 /* No argument has an appropriate type, so remove this
5814 candidate function from the list. */
5816 {
5819 }
5820 }
5821 }
5827 {
5830 /* For these, the built-in candidates set is empty
5831 [over.match.oper]/3. We don't want non-strict matches
5832 because exact matches are always possible with built-in
5833 operators. The built-in candidate set for COMPONENT_REF
5834 would be empty too, but since there are no such built-in
5835 operators, we accept non-strict matches for them. */
5842 }
5846 {
5848 {
5851 /* Don't try anything fancy if we're not allowed to produce
5852 errors. */
5856 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
5857 distinguish between prefix and postfix ++ and
5858 operator++() was used for both, so we allow this with
5859 -fpermissive. */
5860 else
5861 {
5867 }
5874 else
5880 /* The caller will deal with these. */
5890 {
5891 /* If one of the arguments of the operator represents
5892 an invalid use of member function pointer, try to report
5893 a meaningful error ... */
5898 else
5899 {
5900 /* ... Otherwise, report the more generic
5901 "no matching operator found" error */
5902 auto_diagnostic_group d;
5905 }
5906 }
5909 }
5910 }
5911 else
5912 {
5915 {
5917 {
5918 auto_diagnostic_group d;
5921 }
5923 }
5925 {
5931 else
5937 {
5942 /* This prevents build_new_function_call from discarding this
5943 function during instantiation of the enclosing template. */
5946 /* Specify evaluation order as per P0145R2. */
5949 {
5960 }
5961 }
5962 }
5963 else
5964 {
5965 /* Give any warnings we noticed during overload resolution. */
5967 {
5971 }
5973 /* Check for comparison of different enum types. */
5975 {
5987 {
5991 }
5995 }
5997 /* We need to strip any leading REF_BIND so that bitfields
5998 don't cause errors. This should not remove any important
5999 conversions, because builtins don't apply to class
6000 objects directly. */
6007 {
6011 else
6014 /* We need to call warn_logical_operator before
6015 converting arg2 to a boolean_type, but after
6016 decaying an enumerator to its value. */
6023 }
6025 {
6030 }
6032 }
6033 }
6035 user_defined_result_ready:
6037 /* Free all the conversions we allocated. */
6043 builtin:
6045 {
6060 /* Fall through. */
6073 /* Fall through. */
6106 complain),
6109 /* The caller will deal with these. */
6117 }
6119 }
6121 /* Wrapper for above. */
6123 tree
6127 {
6128 tree ret;
6134 }
6136 /* CALL was returned by some call-building function; extract the actual
6137 CALL_EXPR from any bits that have been tacked on, e.g. by
6138 convert_from_reference. */
6140 tree
6142 {
6153 }
6155 /* Returns true if FN has two parameters, of which the second has type
6156 size_t. */
6158 static bool
6160 {
6172 }
6174 /* True if T, an allocation function, has std::align_val_t as its second
6175 argument. */
6177 bool
6179 {
6185 }
6187 /* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation
6188 function (3.7.4.2 [basic.stc.dynamic.deallocation]) with a parameter of
6189 std::align_val_t. */
6191 static bool
6193 {
6197 /* A template instance is never a usual deallocation function,
6198 regardless of its signature. */
6214 }
6216 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
6217 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
6219 bool
6221 {
6222 /* A template instance is never a usual deallocation function,
6223 regardless of its signature. */
6228 /* If a class T has a member deallocation function named operator delete
6229 with exactly one parameter, then that function is a usual
6230 (non-placement) deallocation function. If class T does not declare
6231 such an operator delete but does declare a member deallocation
6232 function named operator delete with exactly two parameters, the second
6233 of which has type std::size_t (18.2), then this function is a usual
6234 deallocation function. */
6246 }
6248 /* Build a call to operator delete. This has to be handled very specially,
6249 because the restrictions on what signatures match are different from all
6250 other call instances. For a normal delete, only a delete taking (void *)
6251 or (void *, size_t) is accepted. For a placement delete, only an exact
6252 match with the placement new is accepted.
6254 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
6255 ADDR is the pointer to be deleted.
6256 SIZE is the size of the memory block to be deleted.
6257 GLOBAL_P is true if the delete-expression should not consider
6258 class-specific delete operators.
6259 PLACEMENT is the corresponding placement new call, or NULL_TREE.
6261 If this call to "operator delete" is being generated as part to
6262 deallocate memory allocated via a new-expression (as per [expr.new]
6263 which requires that if the initialization throws an exception then
6264 we call a deallocation function), then ALLOC_FN is the allocation
6265 function. */
6267 tree
6271 {
6285 /* In [class.free]
6287 If the result of the lookup is ambiguous or inaccessible, or if
6288 the lookup selects a placement deallocation function, the
6289 program is ill-formed.
6291 Therefore, we ask lookup_fnfields to complain about ambiguity. */
6292 {
6296 }
6297 else
6303 /* Strip const and volatile from addr. */
6307 {
6308 /* "A declaration of a placement deallocation function matches the
6309 declaration of a placement allocation function if it has the same
6310 number of parameters and, after parameter transformations (8.3.5),
6311 all parameter types except the first are identical."
6313 So we build up the function type we want and ask instantiate_type
6314 to get it for us. */
6325 /* "If the lookup finds the two-parameter form of a usual deallocation
6326 function (3.7.4.2) and that function, considered as a placement
6327 deallocation function, would have been selected as a match for the
6328 allocation function, the program is ill-formed." */
6330 {
6338 /* But if the class has an operator delete (void *), then that is
6339 the usual deallocation function, so we shouldn't complain
6340 about using the operator delete (void *, size_t). */
6344 {
6349 }
6350 /* Before C++14 a two-parameter global deallocation function is
6351 always a placement deallocation function, but warn if
6352 -Wc++14-compat. */
6354 {
6356 {
6357 auto_diagnostic_group d;
6360 }
6362 }
6365 {
6366 auto_diagnostic_group d;
6368 {
6369 /* Only mention C++14 for namespace-scope delete. */
6372 else
6374 "%qD is a usual (non-placement) deallocation "
6376 }
6377 }
6378 else
6380 ok:;
6381 }
6382 }
6383 else
6384 /* "Any non-placement deallocation function matches a non-placement
6385 allocation function. If the lookup finds a single matching
6386 deallocation function, that function will be called; otherwise, no
6387 deallocation function will be called." */
6389 {
6392 {
6394 {
6397 }
6399 /* -- If the type has new-extended alignment, a function with a
6400 parameter of type std::align_val_t is preferred; otherwise a
6401 function without such a parameter is preferred. If exactly one
6402 preferred function is found, that function is selected and the
6403 selection process terminates. If more than one preferred
6404 function is found, all non-preferred functions are eliminated
6405 from further consideration. */
6407 {
6413 {
6417 }
6418 }
6420 /* -- If the deallocation functions have class scope, the one
6421 without a parameter of type std::size_t is selected. */
6426 /* -- If the type is complete and if, for the second alternative
6427 (delete array) only, the operand is a pointer to a class type
6428 with a non-trivial destructor or a (possibly multi-dimensional)
6429 array thereof, the function with a parameter of type std::size_t
6430 is selected.
6432 -- Otherwise, it is unspecified whether a deallocation function
6433 with a parameter of type std::size_t is selected. */
6434 else
6435 {
6439 /* We need a cookie to determine the array size. */
6441 }
6447 }
6448 }
6450 /* If we have a matching function, call it. */
6452 {
6455 /* If the FN is a member function, make sure that it is
6456 accessible. */
6459 complain);
6461 /* Core issue 901: It's ok to new a type with deleted delete. */
6466 {
6467 /* The placement args might not be suitable for overload
6468 resolution at this point, so build the call directly. */
6478 }
6479 else
6480 {
6481 tree ret;
6487 {
6490 }
6494 }
6495 }
6497 /* [expr.new]
6499 If no unambiguous matching deallocation function can be found,
6500 propagating the exception does not cause the object's memory to
6501 be freed. */
6503 {
6507 alloc_fn);
6509 }
6515 }
6517 /* If the current scope isn't allowed to access DECL along
6518 BASETYPE_PATH, give an error. The most derived class in
6519 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
6520 the declaration to use in the error diagnostic. */
6522 bool
6525 {
6530 {
6531 /* 7.3.3/18: The additional constructors are accessible if they would be
6532 accessible when used to construct an object of the corresponding base
6533 class. */
6537 }
6540 {
6542 {
6546 {
6552 }
6554 {
6560 }
6561 else
6562 {
6567 }
6568 }
6570 }
6573 }
6575 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
6576 bitwise or of LOOKUP_* values. If any errors are warnings are
6577 generated, set *DIAGNOSTIC_FN to "error" or "warning",
6578 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
6579 to NULL. */
6581 static tree
6584 {
6590 /* If the source is a packed field, calling the copy constructor will require
6591 binding the field to the reference parameter to the copy constructor, and
6592 we'll end up with an infinite loop. If we can use a bitwise copy, then
6593 do that now. */
6609 }
6611 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
6612 Also handle a subset of zero as null warnings.
6613 EXPR is implicitly converted to type TOTYPE.
6614 FN and ARGNUM are used for diagnostics. */
6616 static void
6618 {
6619 /* Issue warnings about peculiar, but valid, uses of NULL. */
6622 {
6623 source_location loc =
6630 else
6633 }
6635 /* Issue warnings if "false" is converted to a NULL pointer */
6638 {
6641 "converting %<false%> to pointer type for argument %P "
6643 else
6646 }
6647 /* Handle zero as null pointer warnings for cases other
6648 than EQ_EXPR and NE_EXPR */
6651 {
6652 source_location loc =
6655 }
6656 }
6658 /* We gave a diagnostic during a conversion. If this was in the second
6659 standard conversion sequence of a user-defined conversion sequence, say
6660 which user-defined conversion. */
6662 static void
6664 {
6668 {
6672 }
6673 }
6675 /* Locate the parameter with the given index within FNDECL.
6676 ARGNUM is zero based, -1 indicates the `this' argument of a method.
6677 Return the location of the FNDECL itself if there are problems. */
6679 location_t
6681 {
6683 tree param;
6685 /* Locate param by index within DECL_ARGUMENTS (fndecl). */
6689 ;
6691 /* If something went wrong (e.g. if we have a builtin and thus no arguments),
6692 return the location of FNDECL. */
6697 }
6699 /* Perform the conversions in CONVS on the expression EXPR. FN and
6700 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
6701 indicates the `this' argument of a method. INNER is nonzero when
6702 being called to continue a conversion chain. It is negative when a
6703 reference binding will be applied, positive otherwise. If
6704 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
6705 conversions will be emitted if appropriate. If C_CAST_P is true,
6706 this conversion is coming from a C-style cast; in that case,
6707 conversions to inaccessible bases are permitted. */
6709 static tree
6713 {
6715 diagnostic_t diag_kind;
6731 {
6735 /* Give a helpful error if this is bad because of excess braces. */
6740 {
6746 }
6748 /* Give a helpful error if this is bad because a conversion to bool
6749 from std::nullptr_t requires direct-initialization. */
6757 {
6759 {
6760 auto_diagnostic_group d;
6763 totype);
6769 complain);
6773 complain);
6774 else
6780 }
6782 {
6786 complain);
6788 }
6793 complain);
6796 }
6798 {
6804 }
6810 }
6816 {
6818 {
6822 /* We chose the surrogate function from add_conv_candidate, now we
6823 actually need to build the conversion. */
6829 /* When converting from an init list we consider explicit
6830 constructors, but actually trying to call one is an error. */
6833 /* Unless this is for direct-list-initialization. */
6835 /* And in C++98 a default constructor can't be explicit. */
6837 {
6843 {
6844 auto_diagnostic_group d;
6850 }
6851 else
6854 }
6856 /* If we're initializing from {}, it's value-initialization. */
6860 {
6867 {
6870 }
6872 }
6876 /* Pass LOOKUP_NO_CONVERSION so rvalue/base handling knows not to allow
6877 any more UDCs. */
6879 complain);
6881 /* If this is a constructor or a function returning an aggr type,
6882 we need to build up a TARGET_EXPR. */
6884 {
6887 /* Remember that this was list-initialization. */
6890 }
6893 }
6896 {
6902 else
6904 }
6913 /* If __null has been converted to an integer type, we do not want to
6914 continue to warn about uses of EXPR as an integer, rather than as a
6915 pointer. */
6919 /* We leave bad_p off ck_ambig because overload resolution considers
6920 it valid, it just fails when we try to perform it. So we need to
6921 check complain here, too. */
6923 {
6924 /* Call build_user_type_conversion again for the error. */
6932 }
6936 {
6937 /* Conversion to std::initializer_list<T>. */
6945 /* Convert all the elements. */
6947 {
6958 }
6959 /* Build up the array. */
6960 elttype = cp_build_qualified_type
6964 /* Take the address explicitly rather than via decay_conversion
6965 to avoid the error about taking the address of a temporary. */
6971 /* Build up the initializer_list object. Note: fail gracefully
6972 if the object cannot be completed because, for example, no
6973 definition is provided (c++/80956). */
6983 }
6987 {
6996 }
6999 complain);
7006 };
7016 {
7020 {
7022 {
7023 auto_diagnostic_group d;
7028 }
7030 }
7035 /* Don't introduce copies when passing arguments along to the inherited
7036 constructor. */
7038 && flag_new_inheriting_ctors
7044 /* Copy-list-initialization doesn't actually involve a copy. */
7047 /* Fall through. */
7050 {
7051 /* We are going to bind a reference directly to a base-class
7052 subobject of EXPR. */
7053 /* Build an expression for `*((base*) &expr)'. */
7057 }
7059 /* Copy-initialization where the cv-unqualified version of the source
7060 type is the same class as, or a derived class of, the class of the
7061 destination [is treated as direct-initialization]. [dcl.init] */
7064 /* This conversion is being done in the context of a user-defined
7065 conversion (i.e. the second step of copy-initialization), so
7066 don't allow any more. */
7068 else
7071 /* standard_conversion got LOOKUP_PREFER_RVALUE. */
7075 {
7076 auto_diagnostic_group d;
7081 }
7086 {
7090 {
7092 auto_diagnostic_group d;
7104 else
7111 }
7113 /* If necessary, create a temporary.
7115 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
7116 that need temporaries, even when their types are reference
7117 compatible with the type of reference being bound, so the
7118 upcoming call to cp_build_addr_expr doesn't fail. */
7122 {
7123 /* Otherwise, a temporary of type "cv1 T1" is created and
7124 initialized from the initializer expression using the rules
7125 for a non-reference copy-initialization (8.5). */
7134 {
7135 /* If the reference is volatile or non-const, we
7136 cannot create a temporary. */
7143 else
7147 }
7148 /* If the source is a packed field, and we must use a copy
7149 constructor, then building the target expr will require
7150 binding the field to the reference parameter to the
7151 copy constructor, and we'll end up with an infinite
7152 loop. If we can use a bitwise copy, then we'll be
7153 OK. */
7157 {
7161 }
7163 {
7166 }
7168 }
7170 /* Take the address of the thing to which we will bind the
7171 reference. */
7176 /* Convert it to a pointer to the type referred to by the
7177 reference. This will adjust the pointer if a derived to
7178 base conversion is being performed. */
7181 /* Convert the pointer to the desired reference type. */
7183 }
7189 /* ??? Should the address of a transaction-safe pointer point to the TM
7190 clone, and this conversion look up the primary function? */
7194 /* Warn about deprecated conversion if appropriate. */
7210 }
7220 else
7224 }
7226 /* ARG is being passed to a varargs function. Perform any conversions
7227 required. Return the converted value. */
7229 tree
7231 {
7232 tree arg_type;
7235 /* [expr.call]
7237 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
7238 standard conversions are performed. */
7241 /* [expr.call]
7243 If the argument has integral or enumeration type that is subject
7244 to the integral promotions (_conv.prom_), or a floating point
7245 type that is subject to the floating point promotion
7246 (_conv.fpprom_), the value of the argument is converted to the
7247 promoted type before the call. */
7252 {
7256 "implicit conversion from %qH to %qI when passing "
7260 }
7264 {
7266 {
7268 complain);
7278 }
7279 else
7281 }
7287 /* In a template (or ill-formed code), we can have an incomplete type
7288 even after require_complete_type_sfinae, in which case we don't know
7289 whether it has trivial copy or not. */
7292 {
7293 /* [expr.call] 5.2.2/7:
7294 Passing a potentially-evaluated argument of class type (Clause 9)
7295 with a non-trivial copy constructor or a non-trivial destructor
7296 with no corresponding parameter is conditionally-supported, with
7297 implementation-defined semantics.
7299 We support it as pass-by-invisible-reference, just like a normal
7300 value parameter.
7302 If the call appears in the context of a sizeof expression,
7303 it is not potentially-evaluated. */
7306 {
7310 "passing objects of non-trivially-copyable "
7312 arg_type);
7314 }
7315 /* Build up a real lvalue-to-rvalue conversion in case the
7316 copy constructor is trivial but not callable. */
7320 }
7323 }
7325 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
7327 tree
7329 {
7331 {
7335 }
7345 {
7348 }
7352 {
7353 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat
7354 it as pass by invisible reference. */
7356 "receiving objects of non-trivially-copyable type %q#T "
7362 }
7366 /* Wrap the VA_ARG_EXPR in a TARGET_EXPR now so other code doesn't need to
7367 know how to handle it. */
7370 }
7372 /* TYPE has been given to va_arg. Apply the default conversions which
7373 would have happened when passed via ellipsis. Return the promoted
7374 type, or the passed type if there is no change. */
7376 tree
7378 {
7379 tree promote;
7381 /* Perform the array-to-pointer and function-to-pointer
7382 conversions. */
7390 }
7392 /* ARG is a default argument expression being passed to a parameter of
7393 the indicated TYPE, which is a parameter to FN. PARMNUM is the
7394 zero-based argument number. Do any required conversions. Return
7395 the converted value. */
7398 void
7402 void
7406 tree
7408 tsubst_flags_t complain)
7409 {
7411 tree t;
7413 /* See through clones. */
7415 /* And inheriting ctors. */
7419 /* Detect recursion. */
7422 {
7426 }
7428 /* If the ARG is an unparsed default argument expression, the
7429 conversion cannot be performed. */
7431 {
7436 }
7443 /* Due to:
7445 [dcl.fct.default]
7447 The names in the expression are bound, and the semantic
7448 constraints are checked, at the point where the default
7449 expressions appears.
7451 we must not perform access checks here. */
7453 /* We must make a copy of ARG, in case subsequent processing
7454 alters any part of it. */
7459 complain);
7466 }
7468 /* Returns the type which will really be used for passing an argument of
7469 type TYPE. */
7471 tree
7473 {
7474 /* Pass classes with copy ctors by invisible reference. */
7476 {
7478 /* There are no other pointers to this temporary. */
7480 }
7488 }
7490 /* Actually perform the appropriate conversion. */
7492 tree
7494 {
7495 tree bitfield_type;
7497 /* If VAL is a bitfield, then -- since it has already been converted
7498 to TYPE -- it cannot have a precision greater than TYPE.
7500 If it has a smaller precision, we must widen it here. For
7501 example, passing "int f:3;" to a function expecting an "int" will
7502 not result in any conversion before this point.
7504 If the precision is the same we must not risk widening. For
7505 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
7506 often have type "int", even though the C++ type for the field is
7507 "long long". If the value is being passed to a function
7508 expecting an "int", then no conversions will be required. But,
7509 if we call convert_bitfield_to_declared_type, the bitfield will
7510 be converted to "long long". */
7517 ;
7518 /* Pass classes with copy ctors by invisible reference. */
7527 {
7529 {
7537 "argument of function call might be a candidate "
7539 }
7541 }
7543 }
7545 /* Returns non-zero iff FN is a function with magic varargs, i.e. ones for
7546 which just decay_conversion or no conversions at all should be done.
7547 This is true for some builtins which don't act like normal functions.
7548 Return 2 if no conversions at all should be done, 1 if just
7549 decay_conversion. Return 3 for special treatment of the 3rd argument
7550 for __builtin_*_overflow_p. */
7552 int
7554 {
7557 {
7572 }
7575 }
7577 /* Returns the decl of the dispatcher function if FN is a function version. */
7579 tree
7581 {
7591 {
7595 }
7600 }
7602 /* fn is a function version dispatcher that is marked used. Mark all the
7603 semantically identical function versions it will dispatch as used. */
7605 void
7607 {
7624 /* All semantically identical versions are chained. Traverse and mark each
7625 one of them as used. */
7628 {
7631 }
7632 }
7634 /* Build a call to "the copy constructor" for the type of A, even if it
7635 wouldn't be selected by normal overload resolution. Used for
7636 diagnostics. */
7638 static tree
7640 {
7651 }
7653 /* Return true iff T refers to a base field. */
7655 static bool
7657 {
7666 }
7668 /* We can't elide a copy from a function returning by value to a base
7669 subobject, as the callee might clobber tail padding. Return true iff this
7670 could be that case. */
7672 static bool
7674 {
7675 /* Copy elision only happens with a TARGET_EXPR. */
7679 /* It's safe to elide the copy for a class with no tail padding. */
7682 /* It's safe to elide the copy if we aren't initializing a base object. */
7686 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */
7690 {
7691 /* We'll end up copying from each of the arms of the COND_EXPR directly
7692 into the target, so look at them. */
7697 }
7700 }
7702 /* True iff C is a conversion that binds a reference to a prvalue. */
7704 static bool
7706 {
7723 }
7725 /* Call the trivial destructor for INSTANCE, which can be either an lvalue of
7726 class type or a pointer to class type. */
7728 tree
7730 {
7734 {
7735 no_clobber:
7737 }
7740 {
7744 }
7746 /* A trivial destructor should still clobber the object. */
7750 }
7752 /* Subroutine of the various build_*_call functions. Overload resolution
7753 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
7754 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
7755 bitmask of various LOOKUP_* flags which apply to the call itself. */
7757 static tree
7759 {
7767 tree val;
7776 /* In a template, there is no need to perform all of the work that
7777 is normally done. We are only interested in the type of the call
7778 expression, i.e., the return type of the function. Any semantic
7779 errors will be deferred until the template is instantiated. */
7781 {
7783 tree return_type;
7789 else
7790 /* Otherwise set TREE_USED for the benefit of -Wunused-function.
7791 See PR80598. */
7798 else
7799 {
7802 tree arg;
7810 }
7820 }
7822 /* Give any warnings we noticed during overload resolution. */
7824 {
7828 }
7830 /* Core issue 2327: P0135 doesn't say how to handle the case where the
7831 argument to the copy constructor ends up being a prvalue after
7832 conversion. Let's do the normal processing, but pretend we aren't
7833 actually using the copy constructor. */
7841 {
7844 }
7846 /* OK, we're actually calling this inherited constructor; set its deletedness
7847 appropriately. We can get away with doing this here because calling is
7848 the only way to refer to a constructor. */
7852 /* Make =delete work with SFINAE. */
7854 {
7858 }
7861 {
7862 tree access_fn;
7863 /* If FN is a template function, two cases must be considered.
7864 For example:
7866 struct A {
7867 protected:
7868 template <class T> void f();
7869 };
7870 template <class T> struct B {
7871 protected:
7872 void g();
7873 };
7874 struct C : A, B<int> {
7875 using A::f; // #1
7876 using B<int>::g; // #2
7877 };
7879 In case #1 where `A::f' is a member template, DECL_ACCESS is
7880 recorded in the primary template but not in its specialization.
7881 We check access of FN using its primary template.
7883 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
7884 because it is a member of class template B, DECL_ACCESS is
7885 recorded in the specialization `B<int>::g'. We cannot use its
7886 primary template because `B<T>::g' and `B<int>::g' may have
7887 different access. */
7891 else
7896 }
7898 /* If we're checking for implicit delete, don't bother with argument
7899 conversions. */
7901 {
7905 /* Reject bad conversions now. */
7907 /* else continue to get conversion error. */
7908 }
7910 not_really_used:
7912 /* N3276 magic doesn't apply to nested calls. */
7915 /* No-Cleanup doesn't apply to nested calls either. */
7919 /* Find maximum size of vector to hold converted arguments. */
7926 /* The implicit parameters to a constructor are not considered by overload
7927 resolution, and must be of the proper type. */
7929 {
7930 tree object_arg;
7932 {
7935 }
7936 else
7937 {
7940 }
7943 /* We should never try to call the abstract constructor. */
7947 {
7951 }
7954 {
7955 /* The implicit move specified in 15.8.3/3 fails "...if the type of
7956 the first parameter of the selected constructor is not an rvalue
7957 reference to the object's type (possibly cv-qualified)...." */
7964 }
7965 }
7966 /* Bypass access control for 'this' parameter. */
7968 {
7971 ? first_arg
7974 tree converted_arg;
7975 tree base_binfo;
7981 {
7983 {
7984 auto_diagnostic_group d;
7989 }
7990 else
7992 }
7994 /* See if the function member or the whole class type is declared
7995 final and the call can be devirtualized. */
8000 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
8001 X is called for an object that is not of type X, or of a type
8002 derived from X, the behavior is undefined.
8004 So we can assume that anything passed as 'this' is non-null, and
8005 optimize accordingly. */
8007 /* Convert to the base in which the function was declared. */
8010 arg,
8013 /* Check that the base class is accessible. */
8016 {
8021 else
8023 }
8024 /* If fn was found by a using declaration, the conversion path
8025 will be to the derived class, not the base declaring fn. We
8026 must convert from derived to base. */
8037 else
8041 }
8046 {
8053 /* If the argument is NULL and used to (implicitly) instantiate a
8054 template function (and bind one of the template arguments to
8055 the type of 'long int'), we don't want to warn about passing NULL
8056 to non-pointer argument.
8057 For example, if we have this template function:
8059 template<typename T> void func(T x) {}
8061 we want to warn (when -Wconversion is enabled) in this case:
8063 void foo() {
8064 func<int>(NULL);
8065 }
8067 but not in this case:
8069 void foo() {
8070 func(NULL);
8071 }
8072 */
8079 /* Warn about initializer_list deduction that isn't currently in the
8080 working draft. */
8082 && flag_deduce_init_list
8086 {
8099 {
8107 }
8108 }
8110 /* Set user_conv_p on the argument conversions, so rvalue/base handling
8111 knows not to allow any more UDCs. This needs to happen after we
8112 process cand->warnings. */
8121 arg_complain);
8126 else
8128 }
8130 /* Default arguments */
8132 {
8138 complain);
8142 }
8144 /* Ellipsis */
8147 {
8150 {
8151 /* Do no conversions for certain magic varargs. */
8155 }
8157 /* For other magic varargs only do decay_conversion. */
8162 {
8163 /* Avoid infinite recursion trying to call A(...). */
8165 /* Try to call the actual copy constructor for a good error. */
8168 }
8169 else
8174 }
8179 /* Avoid to do argument-transformation, if warnings for format, and for
8180 nonnull are disabled. Just in case that at least one of them is active
8181 the check_function_arguments function might warn about something. */
8185 || warn_format
8186 || warn_suggest_attribute_format
8188 {
8192 {
8193 /* For -Wformat undo the implicit passing by hidden reference
8194 done by convert_arg_to_ellipsis. */
8198 else
8200 }
8204 }
8207 {
8208 /* Check for passing ellipsis arguments to an inherited constructor. We
8209 could handle this by open-coding the inherited constructor rather than
8210 defining it, but let's not bother now. */
8214 {
8216 {
8220 }
8222 }
8224 /* A base constructor inheriting from a virtual base doesn't get the
8225 inherited arguments, just this and __vtt. */
8228 }
8230 /* Avoid actually calling copy constructors and copy assignment operators,
8231 if possible. */
8238 /* It's unsafe to elide the constructor when handling
8239 a noexcept-expression, it may evaluate to the wrong
8240 value (c++/53025). */
8242 {
8243 tree targ;
8245 tree fa;
8248 /* Pull out the real argument, disregarding const-correctness. */
8250 /* Strip the reference binding for the constructor parameter. */
8254 /* But don't strip any other reference bindings; binding a temporary to a
8255 reference prevents copy elision. */
8261 {
8266 }
8267 else
8272 else
8275 /* In C++17 we shouldn't be copying a TARGET_EXPR except into a base
8276 subobject. */
8279 || force_elide
8280 /* It's from binding the ref parm to a packed field. */
8283 /* See unsafe_copy_elision_p. */
8290 /* [class.copy]: the copy constructor is implicitly defined even if the
8291 implementation elided its use. But don't warn about deprecation when
8292 eliding a temporary, as then no copy is actually performed. */
8297 {
8301 }
8302 else
8305 /* If we're creating a temp and we already have one, don't create a
8306 new one. If we're not creating a temp but we get one, use
8307 INIT_EXPR to collapse the temp into our target. Otherwise, if the
8308 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
8309 temp or an INIT_EXPR otherwise. */
8311 {
8316 }
8319 {
8324 }
8325 }
8329 {
8330 tree to = cp_stabilize_reference
8338 {
8339 /* Avoid copying empty classes. */
8342 }
8344 {
8348 "assignment from temporary initializer_list does not "
8352 }
8353 else
8354 {
8355 /* We must only copy the non-tail padding parts. */
8363 build_index_type
8372 }
8377 }
8379 {
8383 {
8386 no_cleanup_complain);
8387 else
8389 }
8390 }
8398 /* Warn if the built-in writes to an object of a non-trivial type. */
8405 {
8406 tree t;
8413 complain);
8419 }
8420 else
8421 {
8425 }
8431 {
8433 /* build_new_op_1 will clear this when appropriate. */
8435 }
8437 {
8441 }
8443 }
8445 namespace
8446 {
8448 /* Return the DECL of the first non-static subobject of class TYPE
8449 that satisfies the predicate PRED or null if none can be found. */
8452 tree
8454 {
8459 {
8466 }
8472 {
8478 }
8481 }
8483 struct NonPublicField
8484 {
8486 {
8488 }
8489 };
8491 /* Return the DECL of the first non-public subobject of class TYPE
8492 or null if none can be found. */
8496 {
8498 }
8500 struct NonTrivialField
8501 {
8503 {
8505 }
8506 };
8508 /* Return the DECL of the first non-trivial subobject of class TYPE
8509 or null if none can be found. */
8513 {
8515 }
8519 /* Return true if all copy and move assignment operator overloads for
8520 class TYPE are trivial and at least one of them is not deleted and,
8521 when ACCESS is set, accessible. Return false otherwise. Set
8522 HASASSIGN to true when the TYPE has a (not necessarily trivial)
8523 copy or move assignment. */
8525 static bool
8527 {
8531 /* Iterate over overloads of the assignment operator, checking
8532 accessible copy assignments for triviality. */
8535 {
8538 /* Skip operators that aren't copy assignments. */
8545 /* Skip template assignment operators and deleted functions. */
8555 /* Break early when both properties have been determined. */
8558 }
8560 /* Return true if they're all trivial and one of the expressions
8561 TYPE() = TYPE() or TYPE() = (TYPE&)() is valid. */
8566 }
8568 /* Return true if all copy and move ctor overloads for class TYPE are
8569 trivial and at least one of them is not deleted and, when ACCESS is
8570 set, accessible. Return false otherwise. Set each element of HASCTOR[]
8571 to true when the TYPE has a (not necessarily trivial) default and copy
8572 (or move) ctor, respectively. */
8574 static bool
8576 {
8581 {
8584 /* Skip template constructors. */
8590 /* Skip ctors other than default, copy, and move. */
8606 /* Break early when both properties have been determined. */
8609 }
8612 }
8614 /* Issue a warning on a call to the built-in function FNDECL if it is
8615 a raw memory write whose destination is not an object of (something
8616 like) trivial or standard layout type with a non-deleted assignment
8617 and copy ctor. Detects const correctness violations, corrupting
8618 references, virtual table pointers, and bypassing non-trivial
8619 assignments. */
8621 static void
8624 {
8625 /* Except for bcopy where it's second, the destination pointer is
8626 the first argument for all functions handled here. Compute
8627 the index of the destination and source arguments. */
8637 /* Determine the type of the pointed-to object and whether it's
8638 a complete class type. */
8644 /* Check to see if the raw memory call is made by a non-static member
8645 function with THIS as the destination argument for the destination
8646 type. If so, and if the class has no non-trivial bases or members,
8647 be more permissive. */
8651 {
8656 /* FIXME: The following if statement is overly permissive (see
8657 bug 84851). Remove it in GCC 9. */
8669 }
8671 /* True if the class is trivial. */
8674 /* Set to true if DESTYPE has an accessible copy assignment. */
8676 /* True if all of the class' overloaded copy assignment operators
8677 are all trivial (and not deleted) and at least one of them is
8678 accessible. */
8681 /* Set to true if DESTTYPE has an accessible default and copy ctor,
8682 respectively. */
8685 /* True if all of the class' overloaded copy constructors are all
8686 trivial (and not deleted) and at least one of them is accessible. */
8689 /* Set FLD to the first private/protected member of the class. */
8692 /* The warning format string. */
8694 /* A suggested alternative to offer instead of the raw memory call.
8695 Empty string when none can be come up with. */
8700 {
8703 {
8704 /* Diagnose setting non-copy-assignable or non-trivial types,
8705 or types with a private member, to (potentially) non-zero
8706 bytes. Since the value of the bytes being written is unknown,
8707 suggest using assignment instead (if one exists). Also warn
8708 for writes into objects for which zero-initialization doesn't
8709 mean all bits clear (pointer-to-member data, where null is all
8710 bits set). Since the value being written is (most likely)
8711 non-zero, simply suggest assignment (but not copy assignment). */
8719 {
8722 "%qD writing to an object of type %#qT with "
8725 }
8731 }
8732 /* Fall through. */
8735 /* Similarly to the above, diagnose clearing non-trivial or non-
8736 standard layout objects, or objects of types with no assignmenmt.
8737 Since the value being written is known to be zero, suggest either
8738 copy assignment, copy ctor, or default ctor as an alternative,
8739 depending on what's available. */
8762 /* Determine the type of the source object. */
8766 else
8769 /* Since it's impossible to determine wheter the byte copy is
8770 being used in place of assignment to an existing object or
8771 as a substitute for initialization, assume it's the former.
8772 Determine the best alternative to use instead depending on
8773 what's not deleted. */
8794 srctype))
8795 {
8796 /* Warn when copying into a non-trivial object from an object
8797 of a different type other than void or char. */
8799 "%qD copying an object of non-trivial type "
8802 }
8807 srctype))
8808 {
8811 "%qD copying an object of type %#qT with "
8812 "%qs member %qD from an array of %#qT; use "
8815 }
8817 {
8822 /* Finally, warn on partial copies. */
8823 unsigned HOST_WIDE_INT typesize
8829 "a non-trivial type %#qT leaves %wu "
8832 "a non-trivial type %#qT leaves %wu "
8835 }
8850 {
8854 /* Finally, warn on reallocation into insufficient space. */
8856 "%qD moving an object of non-trivial type "
8859 sz);
8860 }
8865 }
8868 {
8872 else
8875 }
8879 }
8881 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
8882 This function performs no overload resolution, conversion, or other
8883 high-level operations. */
8885 tree
8887 tsubst_flags_t complain)
8888 {
8889 tree fndecl;
8891 /* Remember roughly where this call is. */
8898 /* Check that arguments to builtin functions match the expectations. */
8900 && !processing_template_decl
8902 {
8905 /* We need to take care that values to BUILT_IN_NORMAL
8906 are reduced. */
8913 }
8918 /* 5.2.2/11: If a function call is a prvalue of object type: if the
8919 function call is either the operand of a decltype-specifier or the
8920 right operand of a comma operator that is the operand of a
8921 decltype-specifier, a temporary object is not introduced for the
8922 prvalue. The type of the prvalue may be incomplete. */
8924 {
8930 {
8933 }
8934 }
8936 }
8938 /* Returns the value to use for the in-charge parameter when making a
8939 call to a function with the indicated NAME.
8941 FIXME:Can't we find a neater way to do this mapping? */
8943 tree
8945 {
8947 {
8951 }
8952 else
8953 {
8959 }
8962 }
8964 /* We've built up a constructor call RET. Complain if it delegates to the
8965 constructor we're currently compiling. */
8967 static void
8969 {
8975 }
8977 /* Build a call to a constructor, destructor, or an assignment
8978 operator for INSTANCE, an expression with class type. NAME
8979 indicates the special member function to call; *ARGS are the
8980 arguments. ARGS may be NULL. This may change ARGS. BINFO
8981 indicates the base of INSTANCE that is to be passed as the `this'
8982 parameter to the member function called.
8984 FLAGS are the LOOKUP_* flags to use when processing the call.
8986 If NAME indicates a complete object constructor, INSTANCE may be
8987 NULL_TREE. In this case, the caller will call build_cplus_new to
8988 store the newly constructed object into a VAR_DECL. */
8990 tree
8993 {
8994 tree fns;
8995 /* The type of the subobject to be constructed or destroyed. */
8996 tree class_type;
8998 tree ret;
9006 {
9009 /* Shortcut to avoid lazy destructor declaration. */
9011 }
9014 {
9015 /* Resolve the name. */
9020 }
9026 /* Handle the special case where INSTANCE is NULL_TREE. */
9029 else
9030 {
9031 /* Convert to the base class, if necessary. */
9034 {
9036 /* For constructors and destructors, either the base is
9037 non-virtual, or it is virtual but we are doing the
9038 conversion from a constructor or destructor for the
9039 complete object. In either case, we can convert
9040 statically. */
9042 else
9043 {
9044 /* However, for assignment operators, we must convert
9045 dynamically if the base is virtual. */
9049 }
9050 }
9051 }
9055 /* In C++17, "If the initializer expression is a prvalue and the
9056 cv-unqualified version of the source type is the same class as the class
9057 of the destination, the initializer expression is used to initialize the
9058 destination object." Handle that here to avoid doing overload
9059 resolution. */
9063 {
9073 && (same_type_ignoring_top_level_qualifiers_p
9075 {
9084 /* Avoid change of behavior on Wunused-var-2.C. */
9087 }
9088 }
9092 /* When making a call to a constructor or destructor for a subobject
9093 that uses virtual base classes, pass down a pointer to a VTT for
9094 the subobject. */
9098 {
9099 tree vtt;
9100 tree sub_vtt;
9102 /* If the current function is a complete object constructor
9103 or destructor, then we fetch the VTT directly.
9104 Otherwise, we look it up using the VTT we were given. */
9112 else
9116 {
9119 }
9122 }
9127 complain);
9138 }
9140 /* Return the NAME, as a C string. The NAME indicates a function that
9141 is a member of TYPE. *FREE_P is set to true if the caller must
9142 free the memory returned.
9144 Rather than go through all of this, we should simply set the names
9145 of constructors and destructors appropriately, and dispense with
9146 ctor_identifier, dtor_identifier, etc. */
9150 {
9153 /* Assume that we will not allocate memory. */
9155 /* Constructors and destructors are special. */
9157 {
9158 pretty_name
9160 /* For a destructor, add the '~'. */
9162 {
9164 /* Remember that we need to free the memory allocated. */
9166 }
9167 }
9169 {
9172 TFF_PLAIN_IDENTIFIER),
9173 NULL);
9174 /* Remember that we need to free the memory allocated. */
9176 }
9177 else
9181 }
9183 /* If CANDIDATES contains exactly one candidate, return it, otherwise
9184 return NULL. */
9188 {
9196 }
9198 /* If CANDIDATE is invalid due to a bad argument type, return the
9199 pertinent conversion_info.
9201 Otherwise, return NULL. */
9205 {
9206 /* Must be an rr_arg_conversion or rr_bad_arg_conversion. */
9213 {
9222 }
9223 }
9225 /* Issue an error and note complaining about a bad argument type at a
9226 callsite with a single candidate FNDECL.
9228 ARG_LOC is the location of the argument (or UNKNOWN_LOCATION, in which
9229 case input_location is used).
9230 FROM_TYPE is the type of the actual argument; TO_TYPE is the type of
9231 the formal parameter. */
9233 void
9237 {
9238 auto_diagnostic_group d;
9242 {
9245 }
9252 }
9254 /* Subroutine of build_new_method_call_1, for where there are no viable
9255 candidates for the call. */
9257 static void
9260 tree explicit_targs,
9261 tree basetype,
9265 {
9266 auto_diagnostic_group d;
9273 else
9274 {
9275 /* Special-case for when there's a single candidate that's failing
9276 due to a bad argument type. */
9280 {
9285 }
9291 {
9294 }
9302 }
9304 }
9306 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
9307 be set, upon return, to the function called. ARGS may be NULL.
9308 This may change ARGS. */
9310 static tree
9314 {
9319 tree optype;
9321 tree name;
9324 tree call;
9325 tree fn;
9328 tree orig_instance;
9329 tree orig_fns;
9335 /* We don't know what function we're going to call, yet. */
9344 {
9348 }
9353 /* Dismantle the baselink to collect all the information we need. */
9361 {
9365 }
9376 /* Under DR 147 A::A() is an invalid constructor call,
9377 not a functional cast. */
9379 {
9385 auto_diagnostic_group d;
9392 complain);
9394 }
9397 {
9402 }
9404 /* Process the argument list. */
9406 {
9411 }
9413 /* Consider the object argument to be used even if we end up selecting a
9414 static member function. */
9417 /* Figure out whether to skip the first argument for the error
9418 message we will display to users if an error occurs. We don't
9419 want to display any compiler-generated arguments. The "this"
9420 pointer hasn't been added yet. However, we must remove the VTT
9421 pointer if this is a call to a base-class constructor or
9422 destructor. */
9425 {
9426 /* Callers should explicitly indicate whether they want to ctor
9427 the complete object or just the part without virtual bases. */
9430 /* Remove the VTT pointer, if present. */
9435 /* It's OK to call destructors and constructors on cv-qualified
9436 objects. Therefore, convert the INSTANCE to the unqualified
9437 type, if necessary. */
9439 {
9443 }
9444 }
9445 else
9448 /* For the overload resolution we need to find the actual `this`
9449 that would be captured if the call turns out to be to a
9450 non-static member function. Do not actually capture it at this
9451 point. */
9453 /* Constructors don't use the enclosing 'this'. */
9455 else
9458 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9461 /* The number of arguments artificial parms in ARGS; we subtract one because
9462 there's no 'this' in ARGS. */
9465 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
9466 initializer, not T({ }). */
9470 {
9477 /* If the initializer list has no elements and T is a class type with
9478 a default constructor, the object is value-initialized. Handle
9479 this here so we don't need to handle it wherever we use
9480 build_special_member_call. */
9483 /* For a user-provided default constructor, use the normal
9484 mechanisms so that protected access works. */
9489 /* If BASETYPE is an aggregate, we need to do aggregate
9490 initialization. */
9492 {
9495 }
9498 {
9504 }
9506 /* Otherwise go ahead with overload resolution. */
9511 }
9512 else
9521 {
9526 skip_first_for_error,
9527 user_args);
9529 }
9530 else
9531 {
9534 {
9537 tree arglist;
9540 {
9545 auto_diagnostic_group d;
9549 else
9555 }
9557 }
9558 else
9559 {
9567 {
9568 /* This is not an error, it is runtime undefined
9569 behavior. */
9578 fn);
9579 }
9584 {
9589 {
9590 /* We captured 'this' in the current lambda now that
9591 we know we really need it. */
9593 }
9595 /* We can't tell until instantiation time whether we can use
9597 else
9598 {
9601 fn);
9603 }
9604 }
9607 {
9608 /* Optimize away vtable lookup if we know that this
9609 function can't be overridden. We need to check if
9610 the context and the type where we found fn are the same,
9611 actually FN might be defined in a different class
9612 type because of a using-declaration. In this case, we
9613 do not want to perform a non-virtual call. */
9615 && same_type_ignoring_top_level_qualifiers_p
9621 /* Now we know what function is being called. */
9624 /* Build the actual CALL_EXPR. */
9626 /* In an expression of the form `a->f()' where `f' turns
9627 out to be a static member function, `a' is
9628 none-the-less evaluated. */
9632 {
9633 /* But avoid the implicit lvalue-rvalue conversion when 'a'
9634 is volatile. */
9639 }
9643 /* An explicit call of the form "x->~X()" has type
9644 "void". However, on platforms where destructors
9645 return "this" (i.e., those where
9646 targetm.cxx.cdtor_returns_this is true), such calls
9647 will appear to have a return value of pointer type
9648 to the low-level call machinery. We do not want to
9649 change the low-level machinery, since we want to be
9650 able to optimize "delete f()" on such platforms as
9651 "operator delete(~X(f()))" (rather than generating
9652 "t = f(), ~X(t), operator delete (t)"). */
9654 }
9655 }
9656 }
9659 {
9665 {
9668 }
9671 call = (build_min_non_dep_call_vec
9675 orig_args));
9680 }
9682 /* Free all the conversions we allocated. */
9689 }
9691 /* Wrapper for above. */
9693 tree
9697 {
9698 tree ret;
9704 }
9706 /* Returns true iff standard conversion sequence ICS1 is a proper
9707 subsequence of ICS2. */
9709 static bool
9711 {
9712 /* We can assume that a conversion of the same code
9713 between the same types indicates a subsequence since we only get
9714 here if the types we are converting from are the same. */
9721 {
9731 /* At this point, ICS1 cannot be a proper subsequence of
9732 ICS2. We can get a USER_CONV when we are comparing the
9733 second standard conversion sequence of two user conversion
9734 sequences. */
9749 }
9750 }
9752 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
9753 be any _TYPE nodes. */
9755 bool
9757 {
9761 /* We only allow proper derivation here. The DERIVED_FROM_P macro
9762 considers every class derived from itself. */
9765 }
9767 /* We build the ICS for an implicit object parameter as a pointer
9768 conversion sequence. However, such a sequence should be compared
9769 as if it were a reference conversion sequence. If ICS is the
9770 implicit conversion sequence for an implicit object parameter,
9771 modify it accordingly. */
9773 static void
9775 {
9777 {
9778 /* [over.match.funcs]
9780 For non-static member functions, the type of the
9781 implicit object parameter is "reference to cv X"
9782 where X is the class of which the function is a
9783 member and cv is the cv-qualification on the member
9784 function declaration. */
9786 tree reference_type;
9788 /* The `this' parameter is a pointer to a class type. Make the
9789 implicit conversion talk about a reference to that same class
9790 type. */
9803 }
9804 }
9806 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
9807 and return the initial reference binding conversion. Otherwise,
9808 leave *ICS unchanged and return NULL. */
9812 {
9814 {
9819 }
9822 }
9824 /* Compare two implicit conversion sequences according to the rules set out in
9825 [over.ics.rank]. Return values:
9827 1: ics1 is better than ics2
9828 -1: ics2 is better than ics1
9829 0: ics1 and ics2 are indistinguishable */
9831 static int
9833 {
9834 tree from_type1;
9835 tree from_type2;
9836 tree to_type1;
9837 tree to_type2;
9844 /* REF_BINDING is nonzero if the result of the conversion sequence
9845 is a reference type. In that case REF_CONV is the reference
9846 binding conversion. */
9850 /* Compare badness before stripping the reference conversion. */
9856 /* Handle implicit object parameters. */
9860 /* Handle reference parameters. */
9864 /* List-initialization sequence L1 is a better conversion sequence than
9865 list-initialization sequence L2 if L1 converts to
9866 std::initializer_list<X> for some X and L2 does not. */
9872 /* [over.ics.rank]
9874 When comparing the basic forms of implicit conversion sequences (as
9875 defined in _over.best.ics_)
9877 --a standard conversion sequence (_over.ics.scs_) is a better
9878 conversion sequence than a user-defined conversion sequence
9879 or an ellipsis conversion sequence, and
9881 --a user-defined conversion sequence (_over.ics.user_) is a
9882 better conversion sequence than an ellipsis conversion sequence
9883 (_over.ics.ellipsis_). */
9884 /* Use BAD_CONVERSION_RANK because we already checked for a badness
9885 mismatch. If both ICS are bad, we try to make a decision based on
9886 what would have happened if they'd been good. This is not an
9887 extension, we'll still give an error when we build up the call; this
9888 just helps us give a more helpful error message. */
9898 /* Both conversions are ellipsis conversions. */
9901 /* User-defined conversion sequence U1 is a better conversion sequence
9902 than another user-defined conversion sequence U2 if they contain the
9903 same user-defined conversion operator or constructor and if the sec-
9904 ond standard conversion sequence of U1 is better than the second
9905 standard conversion sequence of U2. */
9907 /* Handle list-conversion with the same code even though it isn't always
9908 ranked as a user-defined conversion and it doesn't have a second
9909 standard conversion sequence; it will still have the desired effect.
9910 Specifically, we need to do the reference binding comparison at the
9911 end of this function. */
9914 {
9930 {
9935 }
9936 else
9937 {
9938 /* For ambiguous or aggregate conversions, use the target type as
9939 a proxy for the conversion function. */
9942 }
9944 /* We can just fall through here, after setting up
9945 FROM_TYPE1 and FROM_TYPE2. */
9948 }
9949 else
9950 {
9954 /* We're dealing with two standard conversion sequences.
9956 [over.ics.rank]
9958 Standard conversion sequence S1 is a better conversion
9959 sequence than standard conversion sequence S2 if
9961 --S1 is a proper subsequence of S2 (comparing the conversion
9962 sequences in the canonical form defined by _over.ics.scs_,
9963 excluding any Lvalue Transformation; the identity
9964 conversion sequence is considered to be a subsequence of
9965 any non-identity conversion sequence */
9976 }
9978 /* One sequence can only be a subsequence of the other if they start with
9979 the same type. They can start with different types when comparing the
9980 second standard conversion sequence in two user-defined conversion
9981 sequences. */
9983 {
9988 }
9990 /* [over.ics.rank]
9992 Or, if not that,
9994 --the rank of S1 is better than the rank of S2 (by the rules
9995 defined below):
9997 Standard conversion sequences are ordered by their ranks: an Exact
9998 Match is a better conversion than a Promotion, which is a better
9999 conversion than a Conversion.
10001 Two conversion sequences with the same rank are indistinguishable
10002 unless one of the following rules applies:
10004 --A conversion that does not a convert a pointer, pointer to member,
10005 or std::nullptr_t to bool is better than one that does.
10007 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
10008 so that we do not have to check it explicitly. */
10017 /* A conversion from scalar arithmetic type to complex is worse than a
10018 conversion between scalar arithmetic types. */
10025 {
10028 else
10030 }
10036 {
10041 }
10042 /* The rules for pointers to members A::* are just like the rules
10043 for pointers A*, except opposite: if B is derived from A then
10044 A::* converts to B::*, not vice versa. For that reason, we
10045 switch the from_ and to_ variables here. */
10052 {
10057 }
10062 {
10063 /* This was one of the pointer or pointer-like conversions.
10065 [over.ics.rank]
10067 --If class B is derived directly or indirectly from class A,
10068 conversion of B* to A* is better than conversion of B* to
10069 void*, and conversion of A* to void* is better than
10070 conversion of B* to void*. */
10073 {
10075 deref_from_type2))
10078 deref_from_type1))
10080 }
10083 {
10085 {
10087 {
10089 deref_to_type1))
10091 }
10092 /* We know that DEREF_TO_TYPE1 is `void' here. */
10094 deref_to_type2))
10096 }
10097 }
10100 {
10101 /* [over.ics.rank]
10103 --If class B is derived directly or indirectly from class A
10104 and class C is derived directly or indirectly from B,
10106 --conversion of C* to B* is better than conversion of C* to
10107 A*,
10109 --conversion of B* to A* is better than conversion of C* to
10110 A* */
10112 {
10114 deref_to_type2))
10117 deref_to_type1))
10119 }
10121 {
10123 deref_from_type1))
10126 deref_from_type2))
10128 }
10129 }
10130 }
10133 {
10136 /* [over.ics.rank]
10138 --binding of an expression of type C to a reference of type
10139 B& is better than binding an expression of type C to a
10140 reference of type A&
10142 --conversion of C to B is better than conversion of C to A, */
10145 {
10150 }
10151 }
10154 {
10157 /* [over.ics.rank]
10159 --binding of an expression of type B to a reference of type
10160 A& is better than binding an expression of type C to a
10161 reference of type A&,
10163 --conversion of B to A is better than conversion of C to A */
10166 {
10171 }
10172 }
10174 /* [over.ics.rank]
10176 --S1 and S2 differ only in their qualification conversion and yield
10177 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
10178 qualification signature of type T1 is a proper subset of the cv-
10179 qualification signature of type T2 */
10183 {
10187 }
10189 /* [over.ics.rank]
10191 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
10192 to an implicit object parameter of a non-static member function
10193 declared without a ref-qualifier, and either S1 binds an lvalue
10194 reference to an lvalue and S2 binds an rvalue reference or S1 binds an
10195 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x
10196 draft standard, 13.3.3.2)
10198 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
10199 types to which the references refer are the same type except for
10200 top-level cv-qualifiers, and the type to which the reference
10201 initialized by S2 refers is more cv-qualified than the type to
10202 which the reference initialized by S1 refers.
10204 DR 1328 [over.match.best]: the context is an initialization by
10205 conversion function for direct reference binding (13.3.1.6) of a
10206 reference to function type, the return type of F1 is the same kind of
10207 reference (i.e. lvalue or rvalue) as the reference being initialized,
10208 and the return type of F2 is not. */
10211 {
10218 {
10222 /* Don't prefer a bad conversion that drops cv-quals to a bad
10223 conversion with the wrong rvalueness. */
10227 }
10230 {
10234 {
10235 /* Prefer the one that drops fewer cv-quals. */
10240 }
10242 }
10243 }
10245 /* Neither conversion sequence is better than the other. */
10247 }
10249 /* The source type for this standard conversion sequence. */
10251 static tree
10253 {
10255 {
10260 }
10262 }
10264 /* Note a warning about preferring WINNER to LOSER. We do this by storing
10265 a pointer to LOSER and re-running joust to produce the warning if WINNER
10266 is actually used. */
10268 static void
10270 {
10276 }
10278 /* Compare two candidates for overloading as described in
10279 [over.match.best]. Return values:
10281 1: cand1 is better than cand2
10282 -1: cand2 is better than cand1
10283 0: cand1 and cand2 are indistinguishable */
10285 static int
10287 tsubst_flags_t complain)
10288 {
10294 /* Candidates that involve bad conversions are always worse than those
10295 that don't. */
10301 /* If we have two pseudo-candidates for conversions to the same type,
10302 or two candidates for the same function, arbitrarily pick one. */
10307 /* Prefer a non-deleted function over an implicitly deleted move
10308 constructor or assignment operator. This differs slightly from the
10309 wording for issue 1402 (which says the move op is ignored by overload
10310 resolution), but this way produces better error messages. */
10314 {
10321 }
10323 /* a viable function F1
10324 is defined to be a better function than another viable function F2 if
10325 for all arguments i, ICSi(F1) is not a worse conversion sequence than
10326 ICSi(F2), and then */
10328 /* for some argument j, ICSj(F1) is a better conversion sequence than
10329 ICSj(F2) */
10331 /* For comparing static and non-static member functions, we ignore
10332 the implicit object parameter of the non-static function. The
10333 standard says to pretend that the static function has an object
10334 parm, but that won't work with operator overloading. */
10337 {
10343 /* We're comparing a near-match list constructor and a near-match
10344 non-list constructor. Just treat them as unordered. */
10351 else
10352 {
10355 }
10356 }
10359 {
10365 {
10367 && warn_sign_promo
10379 {
10386 else
10391 {
10395 }
10396 else
10398 }
10401 {
10404 }
10406 }
10407 }
10409 /* warn about confusing overload resolution for user-defined conversions,
10410 either between a constructor and a conversion op, or between two
10411 conversion ops. */
10416 {
10422 else
10425 /* We don't want to complain about `X::operator T1 ()'
10426 beating `X::operator T2 () const', when T2 is a no less
10427 cv-qualified version of T1. */
10430 {
10435 {
10438 }
10441 }
10442 else
10448 {
10452 auto_diagnostic_group d;
10456 {
10458 }
10459 }
10460 else
10462 }
10467 /* DR 495 moved this tiebreaker above the template ones. */
10468 /* or, if not that,
10469 the context is an initialization by user-defined conversion (see
10470 _dcl.init_ and _over.match.user_) and the standard conversion
10471 sequence from the return type of F1 to the destination type (i.e.,
10472 the type of the entity being initialized) is a better conversion
10473 sequence than the standard conversion sequence from the return type
10474 of F2 to the destination type. */
10477 {
10481 }
10483 /* or, if not that,
10484 F1 is a non-template function and F2 is a template function
10485 specialization. */
10492 /* or, if not that,
10493 F1 and F2 are template functions and the function template for F1 is
10494 more specialized than the template for F2 according to the partial
10495 ordering rules. */
10498 {
10499 winner = more_specialized_fn
10502 /* [temp.func.order]: The presence of unused ellipsis and default
10503 arguments has no effect on the partial ordering of function
10504 templates. add_function_candidate() will not have
10505 counted the "this" argument for constructors. */
10509 }
10511 // C++ Concepts
10512 // or, if not that, F1 is more constrained than F2.
10514 {
10518 }
10520 /* F1 is generated from a deduction-guide (13.3.1.8) and F2 is not */
10522 {
10524 /* We distinguish between candidates from an explicit deduction guide and
10525 candidates built from a constructor based on DECL_ARTIFICIAL. */
10532 {
10533 /* Prefer the special copy guide over a declared copy/move
10534 constructor. */
10540 /* Prefer a candidate generated from a non-template constructor. */
10545 }
10546 }
10548 /* F1 is a member of a class D, F2 is a member of a base class B of D, and
10549 for all arguments the corresponding parameters of F1 and F2 have the same
10550 type (CWG 2273/2277). */
10555 {
10569 {
10571 {
10576 }
10579 }
10580 }
10582 /* Check whether we can discard a builtin candidate, either because we
10583 have two identical ones or matching builtin and non-builtin candidates.
10585 (Pedantically in the latter case the builtin which matched the user
10586 function should not be added to the overload set, but we spot it here.
10588 [over.match.oper]
10589 ... the builtin candidates include ...
10590 - do not have the same parameter type list as any non-template
10591 non-member candidate. */
10594 {
10600 {
10602 /* Two built-in candidates; arbitrarily pick one. */
10605 /* cand1 is built-in; prefer cand2. */
10607 else
10608 /* cand2 is built-in; prefer cand1. */
10610 }
10611 }
10613 /* For candidates of a multi-versioned function, make the version with
10614 the highest priority win. This version will be checked for dispatching
10615 first. If this version can be inlined into the caller, the front-end
10616 will simply make a direct call to this function. */
10622 {
10628 /* Check if cand1->fn and cand2->fn are versions of the same function. It
10629 is possible that cand1->fn and cand2->fn are function versions but of
10630 different functions. Check types to see if they are versions of the same
10631 function. */
10634 {
10635 /* Always make the version with the higher priority, more
10636 specialized, win. */
10640 else
10642 }
10643 }
10645 /* If the two function declarations represent the same function (this can
10646 happen with declarations in multiple scopes and arg-dependent lookup),
10647 arbitrarily choose one. But first make sure the default args we're
10648 using match. */
10651 {
10658 {
10659 /* Don't crash if the fn is variadic. */
10664 }
10672 {
10675 {
10677 {
10679 {
10680 auto_diagnostic_group d;
10682 "default argument mismatch in "
10684 {
10689 }
10690 }
10691 else
10693 }
10694 else
10697 }
10700 }
10703 }
10705 tweak:
10707 /* Extension: If the worst conversion for one candidate is worse than the
10708 worst conversion for the other, take the first. */
10710 {
10715 {
10720 }
10726 {
10727 /* Don't choose a deleted function over ambiguity. */
10731 {
10732 auto_diagnostic_group d;
10734 "ISO C++ says that these are ambiguous, even "
10735 "though the worst conversion for the first is better than "
10739 }
10740 else
10743 }
10744 }
10748 }
10750 /* Given a list of candidates for overloading, find the best one, if any.
10751 This algorithm has a worst case of O(2n) (winner is last), and a best
10752 case of O(n/2) (totally ambiguous); much better than a sorting
10753 algorithm. */
10757 {
10762 /* Walk through the list once, comparing each current champ to the next
10763 candidate, knocking out a candidate or two with each comparison. */
10766 {
10770 else
10771 {
10773 {
10778 }
10779 else
10780 {
10783 }
10786 }
10787 }
10789 /* Make sure the champ is better than all the candidates it hasn't yet
10790 been compared to. */
10793 challenger != champ
10796 {
10800 }
10803 }
10805 /* Returns nonzero if things of type FROM can be converted to TO. */
10807 bool
10809 {
10811 /* implicit_conversion only considers user-defined conversions
10812 if it has an expression for the call argument list. */
10816 }
10818 /* Returns nonzero if things of type FROM can be converted to TO with a
10819 standard conversion. */
10821 bool
10823 {
10825 }
10827 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
10829 bool
10831 tsubst_flags_t complain)
10832 {
10837 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10839 /* We want to discard any access checks done for this test,
10840 as we might not be in the appropriate access context and
10841 we'll do the check again when we actually perform the
10842 conversion. */
10849 /* Discard the access checks now. */
10851 /* Free all the conversions we allocated. */
10855 }
10857 /* Like can_convert_arg, but allows dubious conversions as well. */
10859 bool
10861 tsubst_flags_t complain)
10862 {
10866 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10868 /* Try to perform the conversion. */
10871 /* Free all the conversions we allocated. */
10875 }
10877 /* Convert EXPR to TYPE. Return the converted expression.
10879 Note that we allow bad conversions here because by the time we get to
10880 this point we are committed to doing the conversion. If we end up
10881 doing a bad conversion, convert_like will complain. */
10883 tree
10886 {
10893 else
10899 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10907 {
10909 {
10910 /* If expr has unknown type, then it is an overloaded function.
10911 Call instantiate_type to get good error messages. */
10916 else
10917 {
10922 }
10923 }
10925 }
10927 {
10928 /* In a template, we are only concerned about determining the
10929 type of non-dependent expressions, so we do not have to
10930 perform the actual conversion. But for initializers, we
10931 need to be able to perform it at instantiation
10932 (or instantiate_non_dependent_expr) time. */
10936 }
10937 else
10940 /* Free all the conversions we allocated. */
10944 }
10946 tree
10948 {
10950 LOOKUP_IMPLICIT);
10951 }
10953 /* Convert EXPR to TYPE (as a direct-initialization) if that is
10954 permitted. If the conversion is valid, the converted expression is
10955 returned. Otherwise, NULL_TREE is returned, except in the case
10956 that TYPE is a class type; in that case, an error is issued. If
10957 C_CAST_P is true, then this direct-initialization is taking
10958 place as part of a static_cast being attempted as part of a C-style
10959 cast. */
10961 tree
10963 tree expr,
10965 tsubst_flags_t complain)
10966 {
10972 /* [dcl.init]
10974 If the destination type is a (possibly cv-qualified) class type:
10976 -- If the initialization is direct-initialization ...,
10977 constructors are considered. ... If no constructor applies, or
10978 the overload resolution is ambiguous, the initialization is
10979 ill-formed. */
10981 {
10987 }
10989 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10993 c_cast_p,
10998 {
10999 /* In a template, we are only concerned about determining the
11000 type of non-dependent expressions, so we do not have to
11001 perform the actual conversion. But for initializers, we
11002 need to be able to perform it at instantiation
11003 (or instantiate_non_dependent_expr) time. */
11006 }
11007 else
11010 c_cast_p,
11011 complain);
11013 /* Free all the conversions we allocated. */
11017 }
11019 /* When initializing a reference that lasts longer than a full-expression,
11020 this special rule applies:
11022 [class.temporary]
11024 The temporary to which the reference is bound or the temporary
11025 that is the complete object to which the reference is bound
11026 persists for the lifetime of the reference.
11028 The temporaries created during the evaluation of the expression
11029 initializing the reference, except the temporary to which the
11030 reference is bound, are destroyed at the end of the
11031 full-expression in which they are created.
11033 In that case, we store the converted expression into a new
11034 VAR_DECL in a new scope.
11036 However, we want to be careful not to create temporaries when
11037 they are not required. For example, given:
11039 struct B {};
11040 struct D : public B {};
11041 D f();
11042 const B& b = f();
11044 there is no need to copy the return value from "f"; we can just
11045 extend its lifetime. Similarly, given:
11047 struct S {};
11048 struct T { operator S(); };
11049 T t;
11050 const S& s = t;
11052 we can extend the lifetime of the return value of the conversion
11053 operator.
11055 The next several functions are involved in this lifetime extension. */
11057 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The
11058 reference is being bound to a temporary. Create and return a new
11059 VAR_DECL with the indicated TYPE; this variable will store the value to
11060 which the reference is bound. */
11062 tree
11064 {
11067 /* Register the variable. */
11070 {
11071 /* Namespace-scope or local static; give it a mangled name. */
11072 /* FIXME share comdat with decl? */
11083 }
11084 else
11085 /* Create a new cleanup level if necessary. */
11089 }
11091 /* EXPR is the initializer for a variable DECL of reference or
11092 std::initializer_list type. Create, push and return a new VAR_DECL
11093 for the initializer so that it will live as long as DECL. Any
11094 cleanup for the new variable is returned through CLEANUP, and the
11095 code to initialize the new variable is returned through INITP. */
11097 static tree
11100 {
11101 tree init;
11102 tree type;
11103 tree var;
11105 /* Create the temporary variable. */
11109 /* If the rvalue is the result of a function call it will be
11110 a TARGET_EXPR. If it is some other construct (such as a
11111 member access expression where the underlying object is
11112 itself the result of a function call), turn it into a
11113 TARGET_EXPR here. It is important that EXPR be a
11114 TARGET_EXPR below since otherwise the INIT_EXPR will
11115 attempt to make a bitwise copy of EXPR to initialize
11116 VAR. */
11122 {
11126 }
11128 /* Recursively extend temps in this initializer. */
11132 /* Any reference temp has a non-trivial initializer. */
11135 /* If the initializer is constant, put it in DECL_INITIAL so we get
11136 static initialization and use in constant expressions. */
11138 /* As in store_init_value. */
11141 {
11143 {
11144 /* 5.19 says that a constant expression can include an
11145 lvalue-rvalue conversion applied to "a glvalue of literal type
11146 that refers to a non-volatile temporary object initialized
11147 with a constant expression". Rather than try to communicate
11148 that this VAR_DECL is a temporary, just mark it constexpr. */
11153 }
11156 }
11157 else
11158 /* Create the INIT_EXPR that will initialize the temporary
11159 variable. */
11162 {
11167 else
11168 {
11172 }
11174 /* We must be careful to destroy the temporary only
11175 after its initialization has taken place. If the
11176 initialization throws an exception, then the
11177 destructor should not be run. We cannot simply
11178 transform INIT into something like:
11180 (INIT, ({ CLEANUP_STMT; }))
11182 because emit_local_var always treats the
11183 initializer as a full-expression. Thus, the
11184 destructor would run too early; it would run at the
11185 end of initializing the reference variable, rather
11186 than at the end of the block enclosing the
11187 reference variable.
11189 The solution is to pass back a cleanup expression
11190 which the caller is responsible for attaching to
11191 the statement tree. */
11192 }
11193 else
11194 {
11197 {
11200 tls_aggregates);
11201 else
11203 static_aggregates);
11204 }
11205 else
11206 /* Check whether the dtor is callable. */
11208 }
11209 /* Avoid -Wunused-variable warning (c++/38958). */
11216 }
11218 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
11219 initializing a variable of that TYPE. */
11221 tree
11224 {
11232 /* Get the high-water mark for the CONVERSION_OBSTACK. */
11238 {
11240 {
11249 else
11253 }
11255 }
11258 /* Perform the conversion. */
11261 /* We gave an error in build_user_type_conversion_1. */
11263 else
11266 /* Free all the conversions we allocated. */
11270 }
11272 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer,
11273 which is bound either to a reference or a std::initializer_list. */
11275 static tree
11277 {
11282 {
11286 }
11289 /* Deal with binding to a subobject. */
11295 {
11303 }
11305 }
11307 /* INIT is part of the initializer for DECL. If there are any
11308 reference or initializer lists being initialized, extend their
11309 lifetime to match that of DECL. */
11311 tree
11313 {
11319 else
11320 {
11325 {
11327 {
11328 /* The temporary array underlying a std::initializer_list
11329 is handled like a reference temporary. */
11333 }
11334 else
11335 {
11341 }
11345 }
11346 }
11349 }
11351 /* Returns true iff an initializer for TYPE could contain temporaries that
11352 need to be extended because they are bound to references or
11353 std::initializer_list. */
11355 bool
11357 {
11362 {
11369 }
11371 }
11373 /* Returns true iff TYPE is some variant of std::initializer_list. */
11375 bool
11377 {
11382 /* Look through typedefs. */
11387 }
11389 /* Returns true iff DECL is a list constructor: i.e. a constructor which
11390 will accept an argument list of a single std::initializer_list<T>. */
11392 bool
11394 {
11396 tree arg;
11408 /* There are more non-defaulted parms. */
11412 }