1 /* Language-level data type conversion for GNU C++.
2 Copyright (C) 1987-2013 Free Software Foundation, Inc.
3 Hacked by Michael Tiemann (tiemann@cygnus.com)
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
22 /* This file contains the functions for converting C++ expressions
23 to different data types. The only entry point is `convert'.
24 Every language front end must have a `convert' function
25 but what kind of conversions it does will depend on the language. */
29 #include "coretypes.h"
39 static tree
cp_convert_to_pointer (tree
, tree
, tsubst_flags_t
);
40 static tree
convert_to_pointer_force (tree
, tree
, tsubst_flags_t
);
41 static tree
build_type_conversion (tree
, tree
);
42 static tree
build_up_reference (tree
, tree
, int, tree
, tsubst_flags_t
);
43 static void warn_ref_binding (location_t
, tree
, tree
, tree
);
45 /* Change of width--truncation and extension of integers or reals--
46 is represented with NOP_EXPR. Proper functioning of many things
47 assumes that no other conversions can be NOP_EXPRs.
49 Conversion between integer and pointer is represented with CONVERT_EXPR.
50 Converting integer to real uses FLOAT_EXPR
51 and real to integer uses FIX_TRUNC_EXPR.
53 Here is a list of all the functions that assume that widening and
54 narrowing is always done with a NOP_EXPR:
55 In convert.c, convert_to_integer.
56 In c-typeck.c, build_binary_op_nodefault (boolean ops),
57 and c_common_truthvalue_conversion.
58 In expr.c: expand_expr, for operands of a MULT_EXPR.
59 In fold-const.c: fold.
60 In tree.c: get_narrower and get_unwidened.
62 C++: in multiple-inheritance, converting between pointers may involve
63 adjusting them by a delta stored within the class definition. */
65 /* Subroutines of `convert'. */
67 /* if converting pointer to pointer
68 if dealing with classes, check for derived->base or vice versa
69 else if dealing with method pointers, delegate
71 else if converting class, pass off to build_type_conversion
72 else try C-style pointer conversion. */
75 cp_convert_to_pointer (tree type
, tree expr
, tsubst_flags_t complain
)
77 tree intype
= TREE_TYPE (expr
);
80 location_t loc
= EXPR_LOC_OR_HERE (expr
);
82 if (intype
== error_mark_node
)
83 return error_mark_node
;
85 if (MAYBE_CLASS_TYPE_P (intype
))
87 intype
= complete_type (intype
);
88 if (!COMPLETE_TYPE_P (intype
))
90 if (complain
& tf_error
)
91 error_at (loc
, "can%'t convert from incomplete type %qT to %qT",
93 return error_mark_node
;
96 rval
= build_type_conversion (type
, expr
);
99 if ((complain
& tf_error
)
100 && rval
== error_mark_node
)
101 error_at (loc
, "conversion of %qE from %qT to %qT is ambiguous",
107 /* Handle anachronistic conversions from (::*)() to cv void* or (*)(). */
108 if (TREE_CODE (type
) == POINTER_TYPE
109 && (TREE_CODE (TREE_TYPE (type
)) == FUNCTION_TYPE
110 || VOID_TYPE_P (TREE_TYPE (type
))))
112 if (TYPE_PTRMEMFUNC_P (intype
)
113 || TREE_CODE (intype
) == METHOD_TYPE
)
114 return convert_member_func_to_ptr (type
, expr
, complain
);
115 if (TREE_CODE (TREE_TYPE (expr
)) == POINTER_TYPE
)
116 return build_nop (type
, expr
);
117 intype
= TREE_TYPE (expr
);
120 if (expr
== error_mark_node
)
121 return error_mark_node
;
123 form
= TREE_CODE (intype
);
125 if (POINTER_TYPE_P (intype
))
127 intype
= TYPE_MAIN_VARIANT (intype
);
129 if (TYPE_MAIN_VARIANT (type
) != intype
130 && TREE_CODE (type
) == POINTER_TYPE
131 && TREE_CODE (TREE_TYPE (type
)) == RECORD_TYPE
132 && MAYBE_CLASS_TYPE_P (TREE_TYPE (type
))
133 && MAYBE_CLASS_TYPE_P (TREE_TYPE (intype
))
134 && TREE_CODE (TREE_TYPE (intype
)) == RECORD_TYPE
)
136 enum tree_code code
= PLUS_EXPR
;
142 intype_class
= TREE_TYPE (intype
);
143 type_class
= TREE_TYPE (type
);
145 same_p
= same_type_p (TYPE_MAIN_VARIANT (intype_class
),
146 TYPE_MAIN_VARIANT (type_class
));
148 /* Try derived to base conversion. */
150 binfo
= lookup_base (intype_class
, type_class
, ba_check
,
152 if (!same_p
&& !binfo
)
154 /* Try base to derived conversion. */
155 binfo
= lookup_base (type_class
, intype_class
, ba_check
,
159 if (binfo
== error_mark_node
)
160 return error_mark_node
;
164 expr
= build_base_path (code
, expr
, binfo
, 0, complain
);
165 /* Add any qualifier conversions. */
166 return build_nop (type
, expr
);
170 if (TYPE_PTRMEMFUNC_P (type
))
172 if (complain
& tf_error
)
173 error_at (loc
, "cannot convert %qE from type %qT to type %qT",
175 return error_mark_node
;
178 return build_nop (type
, expr
);
180 else if ((TYPE_PTRDATAMEM_P (type
) && TYPE_PTRDATAMEM_P (intype
))
181 || (TYPE_PTRMEMFUNC_P (type
) && TYPE_PTRMEMFUNC_P (intype
)))
182 return convert_ptrmem (type
, expr
, /*allow_inverse_p=*/false,
183 /*c_cast_p=*/false, complain
);
184 else if (TYPE_PTRMEMFUNC_P (intype
))
188 if (TREE_CODE (expr
) == PTRMEM_CST
)
189 return cp_convert_to_pointer (type
, PTRMEM_CST_MEMBER (expr
),
191 else if (TREE_CODE (expr
) == OFFSET_REF
)
193 tree object
= TREE_OPERAND (expr
, 0);
194 return get_member_function_from_ptrfunc (&object
,
195 TREE_OPERAND (expr
, 1),
199 error_at (loc
, "cannot convert %qE from type %qT to type %qT",
201 return error_mark_node
;
204 if (null_ptr_cst_p (expr
))
206 if (complain
& tf_warning
)
207 maybe_warn_zero_as_null_pointer_constant (expr
, loc
);
209 if (TYPE_PTRMEMFUNC_P (type
))
210 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type
), expr
, 0,
211 /*c_cast_p=*/false, complain
);
213 /* A NULL pointer-to-data-member is represented by -1, not by
215 tree val
= (TYPE_PTRDATAMEM_P (type
)
216 ? build_int_cst_type (type
, -1)
217 : build_int_cst (type
, 0));
219 return (TREE_SIDE_EFFECTS (expr
)
220 ? build2 (COMPOUND_EXPR
, type
, expr
, val
) : val
);
222 else if (TYPE_PTRMEM_P (type
) && INTEGRAL_CODE_P (form
))
224 if (complain
& tf_error
)
225 error_at (loc
, "invalid conversion from %qT to %qT", intype
, type
);
226 return error_mark_node
;
229 if (INTEGRAL_CODE_P (form
))
231 if (TYPE_PRECISION (intype
) == POINTER_SIZE
)
232 return build1 (CONVERT_EXPR
, type
, expr
);
233 expr
= cp_convert (c_common_type_for_size (POINTER_SIZE
, 0), expr
,
235 /* Modes may be different but sizes should be the same. There
236 is supposed to be some integral type that is the same width
238 gcc_assert (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr
)))
239 == GET_MODE_SIZE (TYPE_MODE (type
)));
241 return convert_to_pointer (type
, expr
);
244 if (type_unknown_p (expr
))
245 return instantiate_type (type
, expr
, complain
);
247 if (complain
& tf_error
)
248 error_at (loc
, "cannot convert %qE from type %qT to type %qT",
250 return error_mark_node
;
253 /* Like convert, except permit conversions to take place which
254 are not normally allowed due to access restrictions
255 (such as conversion from sub-type to private super-type). */
258 convert_to_pointer_force (tree type
, tree expr
, tsubst_flags_t complain
)
260 tree intype
= TREE_TYPE (expr
);
261 enum tree_code form
= TREE_CODE (intype
);
263 if (form
== POINTER_TYPE
)
265 intype
= TYPE_MAIN_VARIANT (intype
);
267 if (TYPE_MAIN_VARIANT (type
) != intype
268 && TREE_CODE (TREE_TYPE (type
)) == RECORD_TYPE
269 && MAYBE_CLASS_TYPE_P (TREE_TYPE (type
))
270 && MAYBE_CLASS_TYPE_P (TREE_TYPE (intype
))
271 && TREE_CODE (TREE_TYPE (intype
)) == RECORD_TYPE
)
273 enum tree_code code
= PLUS_EXPR
;
276 binfo
= lookup_base (TREE_TYPE (intype
), TREE_TYPE (type
),
277 ba_unique
, NULL
, complain
);
280 binfo
= lookup_base (TREE_TYPE (type
), TREE_TYPE (intype
),
281 ba_unique
, NULL
, complain
);
284 if (binfo
== error_mark_node
)
285 return error_mark_node
;
288 expr
= build_base_path (code
, expr
, binfo
, 0, complain
);
289 if (expr
== error_mark_node
)
290 return error_mark_node
;
291 /* Add any qualifier conversions. */
292 if (!same_type_p (TREE_TYPE (TREE_TYPE (expr
)),
294 expr
= build_nop (type
, expr
);
300 return cp_convert_to_pointer (type
, expr
, complain
);
303 /* We are passing something to a function which requires a reference.
304 The type we are interested in is in TYPE. The initial
305 value we have to begin with is in ARG.
307 FLAGS controls how we manage access checking.
308 DIRECT_BIND in FLAGS controls how any temporaries are generated.
309 If DIRECT_BIND is set, DECL is the reference we're binding to. */
312 build_up_reference (tree type
, tree arg
, int flags
, tree decl
,
313 tsubst_flags_t complain
)
316 tree argtype
= TREE_TYPE (arg
);
317 tree target_type
= TREE_TYPE (type
);
319 gcc_assert (TREE_CODE (type
) == REFERENCE_TYPE
);
321 if ((flags
& DIRECT_BIND
) && ! real_lvalue_p (arg
))
323 /* Create a new temporary variable. We can't just use a TARGET_EXPR
324 here because it needs to live as long as DECL. */
327 arg
= make_temporary_var_for_ref_to_temp (decl
, target_type
);
329 /* Process the initializer for the declaration. */
330 DECL_INITIAL (arg
) = targ
;
331 cp_finish_decl (arg
, targ
, /*init_const_expr_p=*/false, NULL_TREE
,
332 LOOKUP_ONLYCONVERTING
|DIRECT_BIND
);
334 else if (!(flags
& DIRECT_BIND
) && ! lvalue_p (arg
))
335 return get_target_expr_sfinae (arg
, complain
);
337 /* If we had a way to wrap this up, and say, if we ever needed its
338 address, transform all occurrences of the register, into a memory
339 reference we could win better. */
340 rval
= cp_build_addr_expr (arg
, complain
);
341 if (rval
== error_mark_node
)
342 return error_mark_node
;
344 if ((flags
& LOOKUP_PROTECT
)
345 && TYPE_MAIN_VARIANT (argtype
) != TYPE_MAIN_VARIANT (target_type
)
346 && MAYBE_CLASS_TYPE_P (argtype
)
347 && MAYBE_CLASS_TYPE_P (target_type
))
349 /* We go through lookup_base for the access control. */
350 tree binfo
= lookup_base (argtype
, target_type
, ba_check
,
352 if (binfo
== error_mark_node
)
353 return error_mark_node
;
354 if (binfo
== NULL_TREE
)
355 return error_not_base_type (target_type
, argtype
);
356 rval
= build_base_path (PLUS_EXPR
, rval
, binfo
, 1, complain
);
360 = convert_to_pointer_force (build_pointer_type (target_type
),
362 return build_nop (type
, rval
);
365 /* Subroutine of convert_to_reference. REFTYPE is the target reference type.
366 INTYPE is the original rvalue type and DECL is an optional _DECL node
369 [dcl.init.ref] says that if an rvalue is used to
370 initialize a reference, then the reference must be to a
371 non-volatile const type. */
374 warn_ref_binding (location_t loc
, tree reftype
, tree intype
, tree decl
)
376 tree ttl
= TREE_TYPE (reftype
);
378 if (!CP_TYPE_CONST_NON_VOLATILE_P (ttl
))
382 if (CP_TYPE_VOLATILE_P (ttl
) && decl
)
383 msg
= G_("initialization of volatile reference type %q#T from "
384 "rvalue of type %qT");
385 else if (CP_TYPE_VOLATILE_P (ttl
))
386 msg
= G_("conversion to volatile reference type %q#T "
387 "from rvalue of type %qT");
389 msg
= G_("initialization of non-const reference type %q#T from "
390 "rvalue of type %qT");
392 msg
= G_("conversion to non-const reference type %q#T from "
393 "rvalue of type %qT");
395 permerror (loc
, msg
, reftype
, intype
);
399 /* For C++: Only need to do one-level references, but cannot
400 get tripped up on signed/unsigned differences.
402 DECL is either NULL_TREE or the _DECL node for a reference that is being
403 initialized. It can be error_mark_node if we don't know the _DECL but
404 we know it's an initialization. */
407 convert_to_reference (tree reftype
, tree expr
, int convtype
,
408 int flags
, tree decl
, tsubst_flags_t complain
)
410 tree type
= TYPE_MAIN_VARIANT (TREE_TYPE (reftype
));
412 tree rval
= NULL_TREE
;
413 tree rval_as_conversion
= NULL_TREE
;
414 bool can_convert_intype_to_type
;
415 location_t loc
= EXPR_LOC_OR_HERE (expr
);
417 if (TREE_CODE (type
) == FUNCTION_TYPE
418 && TREE_TYPE (expr
) == unknown_type_node
)
419 expr
= instantiate_type (type
, expr
, complain
);
421 if (expr
== error_mark_node
)
422 return error_mark_node
;
424 intype
= TREE_TYPE (expr
);
426 gcc_assert (TREE_CODE (intype
) != REFERENCE_TYPE
);
427 gcc_assert (TREE_CODE (reftype
) == REFERENCE_TYPE
);
429 intype
= TYPE_MAIN_VARIANT (intype
);
431 can_convert_intype_to_type
= can_convert (type
, intype
, complain
);
433 if (!can_convert_intype_to_type
434 && (convtype
& CONV_IMPLICIT
) && MAYBE_CLASS_TYPE_P (intype
)
435 && ! (flags
& LOOKUP_NO_CONVERSION
))
437 /* Look for a user-defined conversion to lvalue that we can use. */
440 = build_type_conversion (reftype
, expr
);
442 if (rval_as_conversion
&& rval_as_conversion
!= error_mark_node
443 && real_lvalue_p (rval_as_conversion
))
445 expr
= rval_as_conversion
;
446 rval_as_conversion
= NULL_TREE
;
448 can_convert_intype_to_type
= 1;
452 if (((convtype
& CONV_STATIC
) && can_convert (intype
, type
, complain
))
453 || ((convtype
& CONV_IMPLICIT
) && can_convert_intype_to_type
))
456 tree ttl
= TREE_TYPE (reftype
);
457 tree ttr
= lvalue_type (expr
);
459 if ((complain
& tf_warning
)
460 && ! real_lvalue_p (expr
))
461 warn_ref_binding (loc
, reftype
, intype
, decl
);
463 if (! (convtype
& CONV_CONST
)
464 && !at_least_as_qualified_p (ttl
, ttr
))
466 if (complain
& tf_error
)
467 permerror (loc
, "conversion from %qT to %qT discards qualifiers",
470 return error_mark_node
;
474 return build_up_reference (reftype
, expr
, flags
, decl
, complain
);
476 else if ((convtype
& CONV_REINTERPRET
) && lvalue_p (expr
))
478 /* When casting an lvalue to a reference type, just convert into
479 a pointer to the new type and deference it. This is allowed
480 by San Diego WP section 5.2.9 paragraph 12, though perhaps it
481 should be done directly (jason). (int &)ri ---> *(int*)&ri */
483 /* B* bp; A& ar = (A&)bp; is valid, but it's probably not what they
485 if ((complain
& tf_warning
)
486 && TREE_CODE (intype
) == POINTER_TYPE
487 && (comptypes (TREE_TYPE (intype
), type
,
488 COMPARE_BASE
| COMPARE_DERIVED
)))
489 warning_at (loc
, 0, "casting %qT to %qT does not dereference pointer",
492 rval
= cp_build_addr_expr (expr
, complain
);
493 if (rval
!= error_mark_node
)
494 rval
= convert_force (build_pointer_type (TREE_TYPE (reftype
)),
496 if (rval
!= error_mark_node
)
497 rval
= build1 (NOP_EXPR
, reftype
, rval
);
501 rval
= convert_for_initialization (NULL_TREE
, type
, expr
, flags
,
502 ICR_CONVERTING
, 0, 0, complain
);
503 if (rval
== NULL_TREE
|| rval
== error_mark_node
)
505 if (complain
& tf_warning
)
506 warn_ref_binding (loc
, reftype
, intype
, decl
);
507 rval
= build_up_reference (reftype
, rval
, flags
, decl
, complain
);
512 /* If we found a way to convert earlier, then use it. */
516 if (complain
& tf_error
)
517 error_at (loc
, "cannot convert type %qT to type %qT", intype
, reftype
);
519 return error_mark_node
;
522 /* We are using a reference VAL for its value. Bash that reference all the
523 way down to its lowest form. */
526 convert_from_reference (tree val
)
529 && TREE_CODE (TREE_TYPE (val
)) == REFERENCE_TYPE
)
531 tree t
= TREE_TYPE (TREE_TYPE (val
));
532 tree ref
= build1 (INDIRECT_REF
, t
, val
);
535 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
536 so that we get the proper error message if the result is used
537 to assign to. Also, &* is supposed to be a no-op. */
538 TREE_READONLY (ref
) = CP_TYPE_CONST_P (t
);
539 TREE_THIS_VOLATILE (ref
) = CP_TYPE_VOLATILE_P (t
);
540 TREE_SIDE_EFFECTS (ref
)
541 = (TREE_THIS_VOLATILE (ref
) || TREE_SIDE_EFFECTS (val
));
548 /* Really perform an lvalue-to-rvalue conversion, including copying an
549 argument of class type into a temporary. */
552 force_rvalue (tree expr
, tsubst_flags_t complain
)
554 tree type
= TREE_TYPE (expr
);
555 if (MAYBE_CLASS_TYPE_P (type
) && TREE_CODE (expr
) != TARGET_EXPR
)
557 vec
<tree
, va_gc
> *args
= make_tree_vector_single (expr
);
558 expr
= build_special_member_call (NULL_TREE
, complete_ctor_identifier
,
559 &args
, type
, LOOKUP_NORMAL
, complain
);
560 release_tree_vector (args
);
561 expr
= build_cplus_new (type
, expr
, complain
);
564 expr
= decay_conversion (expr
, complain
);
570 /* If EXPR and ORIG are INTEGER_CSTs, return a version of EXPR that has
571 TREE_OVERFLOW set only if it is set in ORIG. Otherwise, return EXPR
575 ignore_overflows (tree expr
, tree orig
)
577 if (TREE_CODE (expr
) == INTEGER_CST
578 && TREE_CODE (orig
) == INTEGER_CST
579 && TREE_OVERFLOW (expr
) != TREE_OVERFLOW (orig
))
581 gcc_assert (!TREE_OVERFLOW (orig
));
582 /* Ensure constant sharing. */
583 expr
= build_int_cst_wide (TREE_TYPE (expr
),
584 TREE_INT_CST_LOW (expr
),
585 TREE_INT_CST_HIGH (expr
));
590 /* Fold away simple conversions, but make sure TREE_OVERFLOW is set
594 cp_fold_convert (tree type
, tree expr
)
596 tree conv
= fold_convert (type
, expr
);
597 conv
= ignore_overflows (conv
, expr
);
601 /* C++ conversions, preference to static cast conversions. */
604 cp_convert (tree type
, tree expr
, tsubst_flags_t complain
)
606 return ocp_convert (type
, expr
, CONV_OLD_CONVERT
, LOOKUP_NORMAL
, complain
);
609 /* C++ equivalent of convert_and_check but using cp_convert as the
612 Convert EXPR to TYPE, warning about conversion problems with constants.
613 Invoke this function on every expression that is converted implicitly,
614 i.e. because of language rules and not because of an explicit cast. */
617 cp_convert_and_check (tree type
, tree expr
, tsubst_flags_t complain
)
621 if (TREE_TYPE (expr
) == type
)
624 result
= cp_convert (type
, expr
, complain
);
626 if ((complain
& tf_warning
)
627 && c_inhibit_evaluation_warnings
== 0
628 && !TREE_OVERFLOW_P (expr
)
629 && result
!= error_mark_node
)
630 warnings_for_convert_and_check (type
, expr
, result
);
637 FLAGS indicates how we should behave. */
640 ocp_convert (tree type
, tree expr
, int convtype
, int flags
,
641 tsubst_flags_t complain
)
644 enum tree_code code
= TREE_CODE (type
);
645 const char *invalid_conv_diag
;
647 location_t loc
= EXPR_LOC_OR_HERE (expr
);
649 if (error_operand_p (e
) || type
== error_mark_node
)
650 return error_mark_node
;
652 complete_type (type
);
653 complete_type (TREE_TYPE (expr
));
655 if ((invalid_conv_diag
656 = targetm
.invalid_conversion (TREE_TYPE (expr
), type
)))
658 if (complain
& tf_error
)
659 error (invalid_conv_diag
);
660 return error_mark_node
;
663 /* FIXME remove when moving to c_fully_fold model. */
664 /* FIXME do we still need this test? */
665 if (!CLASS_TYPE_P (type
))
666 e
= integral_constant_value (e
);
667 if (error_operand_p (e
))
668 return error_mark_node
;
670 if (MAYBE_CLASS_TYPE_P (type
) && (convtype
& CONV_FORCE_TEMP
))
671 /* We need a new temporary; don't take this shortcut. */;
672 else if (same_type_ignoring_top_level_qualifiers_p (type
, TREE_TYPE (e
)))
674 if (same_type_p (type
, TREE_TYPE (e
)))
675 /* The call to fold will not always remove the NOP_EXPR as
676 might be expected, since if one of the types is a typedef;
677 the comparison in fold is just equality of pointers, not a
678 call to comptypes. We don't call fold in this case because
679 that can result in infinite recursion; fold will call
680 convert, which will call ocp_convert, etc. */
682 /* For complex data types, we need to perform componentwise
684 else if (TREE_CODE (type
) == COMPLEX_TYPE
)
685 return fold_if_not_in_template (convert_to_complex (type
, e
));
686 else if (TREE_CODE (type
) == VECTOR_TYPE
)
687 return fold_if_not_in_template (convert_to_vector (type
, e
));
688 else if (TREE_CODE (e
) == TARGET_EXPR
)
690 /* Don't build a NOP_EXPR of class type. Instead, change the
691 type of the temporary. */
692 TREE_TYPE (e
) = TREE_TYPE (TARGET_EXPR_SLOT (e
)) = type
;
697 /* We shouldn't be treating objects of ADDRESSABLE type as
699 gcc_assert (!TREE_ADDRESSABLE (type
));
700 return fold_if_not_in_template (build_nop (type
, e
));
704 e1
= targetm
.convert_to_type (type
, e
);
708 if (code
== VOID_TYPE
&& (convtype
& CONV_STATIC
))
710 e
= convert_to_void (e
, ICV_CAST
, complain
);
714 if (INTEGRAL_CODE_P (code
))
716 tree intype
= TREE_TYPE (e
);
719 if (TREE_CODE (type
) == ENUMERAL_TYPE
)
721 /* enum = enum, enum = int, enum = float, (enum)pointer are all
723 if (((INTEGRAL_OR_ENUMERATION_TYPE_P (intype
)
724 || TREE_CODE (intype
) == REAL_TYPE
)
725 && ! (convtype
& CONV_STATIC
))
726 || TREE_CODE (intype
) == POINTER_TYPE
)
728 if (complain
& tf_error
)
729 permerror (loc
, "conversion from %q#T to %q#T", intype
, type
);
731 return error_mark_node
;
734 /* [expr.static.cast]
736 8. A value of integral or enumeration type can be explicitly
737 converted to an enumeration type. The value is unchanged if
738 the original value is within the range of the enumeration
739 values. Otherwise, the resulting enumeration value is
741 if ((complain
& tf_warning
)
742 && TREE_CODE (e
) == INTEGER_CST
743 && !int_fits_type_p (e
, ENUM_UNDERLYING_TYPE (type
)))
744 warning_at (loc
, OPT_Wconversion
,
745 "the result of the conversion is unspecified because "
746 "%qE is outside the range of type %qT",
749 if (MAYBE_CLASS_TYPE_P (intype
))
752 rval
= build_type_conversion (type
, e
);
755 if (complain
& tf_error
)
756 error_at (loc
, "%q#T used where a %qT was expected", intype
, type
);
757 return error_mark_node
;
759 if (code
== BOOLEAN_TYPE
)
761 if (TREE_CODE (intype
) == VOID_TYPE
)
763 if (complain
& tf_error
)
765 "could not convert %qE from %<void%> to %<bool%>",
767 return error_mark_node
;
770 /* We can't implicitly convert a scoped enum to bool, so convert
771 to the underlying type first. */
772 if (SCOPED_ENUM_P (intype
) && (convtype
& CONV_STATIC
))
773 e
= build_nop (ENUM_UNDERLYING_TYPE (intype
), e
);
774 return cp_truthvalue_conversion (e
);
777 converted
= fold_if_not_in_template (convert_to_integer (type
, e
));
779 /* Ignore any integer overflow caused by the conversion. */
780 return ignore_overflows (converted
, e
);
782 if (NULLPTR_TYPE_P (type
) && e
&& null_ptr_cst_p (e
))
784 if (complain
& tf_warning
)
785 maybe_warn_zero_as_null_pointer_constant (e
, loc
);
788 if (POINTER_TYPE_P (type
) || TYPE_PTRMEM_P (type
))
789 return fold_if_not_in_template (cp_convert_to_pointer (type
, e
, complain
));
790 if (code
== VECTOR_TYPE
)
792 tree in_vtype
= TREE_TYPE (e
);
793 if (MAYBE_CLASS_TYPE_P (in_vtype
))
796 ret_val
= build_type_conversion (type
, e
);
799 if (complain
& tf_error
)
800 error_at (loc
, "%q#T used where a %qT was expected",
802 return error_mark_node
;
804 return fold_if_not_in_template (convert_to_vector (type
, e
));
806 if (code
== REAL_TYPE
|| code
== COMPLEX_TYPE
)
808 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (e
)))
811 rval
= build_type_conversion (type
, e
);
814 else if (complain
& tf_error
)
816 "%q#T used where a floating point value was expected",
819 if (code
== REAL_TYPE
)
820 return fold_if_not_in_template (convert_to_real (type
, e
));
821 else if (code
== COMPLEX_TYPE
)
822 return fold_if_not_in_template (convert_to_complex (type
, e
));
825 /* New C++ semantics: since assignment is now based on
826 memberwise copying, if the rhs type is derived from the
827 lhs type, then we may still do a conversion. */
828 if (RECORD_OR_UNION_CODE_P (code
))
830 tree dtype
= TREE_TYPE (e
);
831 tree ctor
= NULL_TREE
;
833 dtype
= TYPE_MAIN_VARIANT (dtype
);
835 /* Conversion between aggregate types. New C++ semantics allow
836 objects of derived type to be cast to objects of base type.
837 Old semantics only allowed this between pointers.
839 There may be some ambiguity between using a constructor
840 vs. using a type conversion operator when both apply. */
844 if (abstract_virtuals_error_sfinae (NULL_TREE
, type
, complain
))
845 return error_mark_node
;
847 if (BRACE_ENCLOSED_INITIALIZER_P (ctor
))
848 ctor
= perform_implicit_conversion (type
, ctor
, complain
);
849 else if ((flags
& LOOKUP_ONLYCONVERTING
)
850 && ! (CLASS_TYPE_P (dtype
) && DERIVED_FROM_P (type
, dtype
)))
851 /* For copy-initialization, first we create a temp of the proper type
852 with a user-defined conversion sequence, then we direct-initialize
853 the target with the temp (see [dcl.init]). */
854 ctor
= build_user_type_conversion (type
, ctor
, flags
, complain
);
857 vec
<tree
, va_gc
> *ctor_vec
= make_tree_vector_single (ctor
);
858 ctor
= build_special_member_call (NULL_TREE
,
859 complete_ctor_identifier
,
861 type
, flags
, complain
);
862 release_tree_vector (ctor_vec
);
865 return build_cplus_new (type
, ctor
, complain
);
868 if (complain
& tf_error
)
870 /* If the conversion failed and expr was an invalid use of pointer to
871 member function, try to report a meaningful error. */
872 if (invalid_nonstatic_memfn_p (expr
, complain
))
873 /* We displayed the error message. */;
875 error_at (loc
, "conversion from %qT to non-scalar type %qT requested",
876 TREE_TYPE (expr
), type
);
878 return error_mark_node
;
881 /* When an expression is used in a void context, its value is discarded and
882 no lvalue-rvalue and similar conversions happen [expr.static.cast/4,
883 stmt.expr/1, expr.comma/1]. This permits dereferencing an incomplete type
884 in a void context. The C++ standard does not define what an `access' to an
885 object is, but there is reason to believe that it is the lvalue to rvalue
886 conversion -- if it were not, `*&*p = 1' would violate [expr]/4 in that it
887 accesses `*p' not to calculate the value to be stored. But, dcl.type.cv/8
888 indicates that volatile semantics should be the same between C and C++
889 where ever possible. C leaves it implementation defined as to what
890 constitutes an access to a volatile. So, we interpret `*vp' as a read of
891 the volatile object `vp' points to, unless that is an incomplete type. For
892 volatile references we do not do this interpretation, because that would
893 make it impossible to ignore the reference return value from functions. We
894 issue warnings in the confusing cases.
896 The IMPLICIT is ICV_CAST when the user is explicitly converting an expression
897 to void via a cast. If an expression is being implicitly converted, IMPLICIT
898 indicates the context of the implicit conversion. */
901 convert_to_void (tree expr
, impl_conv_void implicit
, tsubst_flags_t complain
)
903 location_t loc
= EXPR_LOC_OR_HERE (expr
);
905 if (expr
== error_mark_node
906 || TREE_TYPE (expr
) == error_mark_node
)
907 return error_mark_node
;
909 if (implicit
== ICV_CAST
)
910 mark_exp_read (expr
);
915 while (TREE_CODE (exprv
) == COMPOUND_EXPR
)
916 exprv
= TREE_OPERAND (exprv
, 1);
918 || handled_component_p (exprv
)
919 || TREE_CODE (exprv
) == INDIRECT_REF
)
920 /* Expr is not being 'used' here, otherwise we whould have
921 called mark_{rl}value_use use here, which would have in turn
922 called mark_exp_read. Rather, we call mark_exp_read directly
923 to avoid some warnings when
924 -Wunused-but-set-{variable,parameter} is in effect. */
925 mark_exp_read (exprv
);
928 if (!TREE_TYPE (expr
))
930 if (invalid_nonstatic_memfn_p (expr
, complain
))
931 return error_mark_node
;
932 if (TREE_CODE (expr
) == PSEUDO_DTOR_EXPR
)
934 if (complain
& tf_error
)
935 error_at (loc
, "pseudo-destructor is not called");
936 return error_mark_node
;
938 if (VOID_TYPE_P (TREE_TYPE (expr
)))
940 switch (TREE_CODE (expr
))
944 /* The two parts of a cond expr might be separate lvalues. */
945 tree op1
= TREE_OPERAND (expr
,1);
946 tree op2
= TREE_OPERAND (expr
,2);
947 bool side_effects
= ((op1
&& TREE_SIDE_EFFECTS (op1
))
948 || TREE_SIDE_EFFECTS (op2
));
949 tree new_op1
, new_op2
;
951 if (implicit
!= ICV_CAST
&& !side_effects
)
954 new_op1
= convert_to_void (op1
, ICV_SECOND_OF_COND
, complain
);
955 new_op2
= convert_to_void (op2
, ICV_THIRD_OF_COND
, complain
);
960 new_op1
= convert_to_void (op1
, ICV_CAST
, complain
);
961 new_op2
= convert_to_void (op2
, ICV_CAST
, complain
);
964 expr
= build3 (COND_EXPR
, TREE_TYPE (new_op2
),
965 TREE_OPERAND (expr
, 0), new_op1
, new_op2
);
971 /* The second part of a compound expr contains the value. */
972 tree op1
= TREE_OPERAND (expr
,1);
974 if (implicit
!= ICV_CAST
&& !TREE_NO_WARNING (expr
))
975 new_op1
= convert_to_void (op1
, ICV_RIGHT_OF_COMMA
, complain
);
977 new_op1
= convert_to_void (op1
, ICV_CAST
, complain
);
981 tree t
= build2 (COMPOUND_EXPR
, TREE_TYPE (new_op1
),
982 TREE_OPERAND (expr
, 0), new_op1
);
989 case NON_LVALUE_EXPR
:
991 /* These have already decayed to rvalue. */
994 case CALL_EXPR
: /* We have a special meaning for volatile void fn(). */
999 tree type
= TREE_TYPE (expr
);
1000 int is_reference
= TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0)))
1002 int is_volatile
= TYPE_VOLATILE (type
);
1003 int is_complete
= COMPLETE_TYPE_P (complete_type (type
));
1005 /* Can't load the value if we don't know the type. */
1006 if (is_volatile
&& !is_complete
)
1008 if (complain
& tf_warning
)
1012 warning_at (loc
, 0, "conversion to void will not access "
1013 "object of incomplete type %qT", type
);
1015 case ICV_SECOND_OF_COND
:
1016 warning_at (loc
, 0, "indirection will not access object of "
1017 "incomplete type %qT in second operand "
1018 "of conditional expression", type
);
1020 case ICV_THIRD_OF_COND
:
1021 warning_at (loc
, 0, "indirection will not access object of "
1022 "incomplete type %qT in third operand "
1023 "of conditional expression", type
);
1025 case ICV_RIGHT_OF_COMMA
:
1026 warning_at (loc
, 0, "indirection will not access object of "
1027 "incomplete type %qT in right operand of "
1028 "comma operator", type
);
1030 case ICV_LEFT_OF_COMMA
:
1031 warning_at (loc
, 0, "indirection will not access object of "
1032 "incomplete type %qT in left operand of "
1033 "comma operator", type
);
1036 warning_at (loc
, 0, "indirection will not access object of "
1037 "incomplete type %qT in statement", type
);
1039 case ICV_THIRD_IN_FOR
:
1040 warning_at (loc
, 0, "indirection will not access object of "
1041 "incomplete type %qT in for increment "
1042 "expression", type
);
1048 /* Don't load the value if this is an implicit dereference, or if
1049 the type needs to be handled by ctors/dtors. */
1050 else if (is_volatile
&& is_reference
)
1052 if (complain
& tf_warning
)
1056 warning_at (loc
, 0, "conversion to void will not access "
1057 "object of type %qT", type
);
1059 case ICV_SECOND_OF_COND
:
1060 warning_at (loc
, 0, "implicit dereference will not access "
1061 "object of type %qT in second operand of "
1062 "conditional expression", type
);
1064 case ICV_THIRD_OF_COND
:
1065 warning_at (loc
, 0, "implicit dereference will not access "
1066 "object of type %qT in third operand of "
1067 "conditional expression", type
);
1069 case ICV_RIGHT_OF_COMMA
:
1070 warning_at (loc
, 0, "implicit dereference will not access "
1071 "object of type %qT in right operand of "
1072 "comma operator", type
);
1074 case ICV_LEFT_OF_COMMA
:
1075 warning_at (loc
, 0, "implicit dereference will not access "
1076 "object of type %qT in left operand of comma "
1080 warning_at (loc
, 0, "implicit dereference will not access "
1081 "object of type %qT in statement", type
);
1083 case ICV_THIRD_IN_FOR
:
1084 warning_at (loc
, 0, "implicit dereference will not access "
1085 "object of type %qT in for increment expression",
1092 else if (is_volatile
&& TREE_ADDRESSABLE (type
))
1094 if (complain
& tf_warning
)
1098 warning_at (loc
, 0, "conversion to void will not access "
1099 "object of non-trivially-copyable type %qT",
1102 case ICV_SECOND_OF_COND
:
1103 warning_at (loc
, 0, "indirection will not access object of "
1104 "non-trivially-copyable type %qT in second "
1105 "operand of conditional expression", type
);
1107 case ICV_THIRD_OF_COND
:
1108 warning_at (loc
, 0, "indirection will not access object of "
1109 "non-trivially-copyable type %qT in third "
1110 "operand of conditional expression", type
);
1112 case ICV_RIGHT_OF_COMMA
:
1113 warning_at (loc
, 0, "indirection will not access object of "
1114 "non-trivially-copyable type %qT in right "
1115 "operand of comma operator", type
);
1117 case ICV_LEFT_OF_COMMA
:
1118 warning_at (loc
, 0, "indirection will not access object of "
1119 "non-trivially-copyable type %qT in left "
1120 "operand of comma operator", type
);
1123 warning_at (loc
, 0, "indirection will not access object of "
1124 "non-trivially-copyable type %qT in statement",
1127 case ICV_THIRD_IN_FOR
:
1128 warning_at (loc
, 0, "indirection will not access object of "
1129 "non-trivially-copyable type %qT in for "
1130 "increment expression", type
);
1136 if (is_reference
|| !is_volatile
|| !is_complete
|| TREE_ADDRESSABLE (type
))
1138 /* Emit a warning (if enabled) when the "effect-less" INDIRECT_REF
1139 operation is stripped off. Note that we don't warn about
1140 - an expression with TREE_NO_WARNING set. (For an example of
1141 such expressions, see build_over_call in call.c.)
1142 - automatic dereferencing of references, since the user cannot
1143 control it. (See also warn_if_unused_value() in c-common.c.) */
1144 if (warn_unused_value
1145 && implicit
!= ICV_CAST
1146 && (complain
& tf_warning
)
1147 && !TREE_NO_WARNING (expr
)
1149 warning_at (loc
, OPT_Wunused_value
, "value computed is not used");
1150 expr
= TREE_OPERAND (expr
, 0);
1158 /* External variables might be incomplete. */
1159 tree type
= TREE_TYPE (expr
);
1160 int is_complete
= COMPLETE_TYPE_P (complete_type (type
));
1162 if (TYPE_VOLATILE (type
) && !is_complete
&& (complain
& tf_warning
))
1166 warning_at (loc
, 0, "conversion to void will not access "
1167 "object %qE of incomplete type %qT", expr
, type
);
1169 case ICV_SECOND_OF_COND
:
1170 warning_at (loc
, 0, "variable %qE of incomplete type %qT will "
1171 "not be accessed in second operand of "
1172 "conditional expression", expr
, type
);
1174 case ICV_THIRD_OF_COND
:
1175 warning_at (loc
, 0, "variable %qE of incomplete type %qT will "
1176 "not be accessed in third operand of "
1177 "conditional expression", expr
, type
);
1179 case ICV_RIGHT_OF_COMMA
:
1180 warning_at (loc
, 0, "variable %qE of incomplete type %qT will "
1181 "not be accessed in right operand of comma operator",
1184 case ICV_LEFT_OF_COMMA
:
1185 warning_at (loc
, 0, "variable %qE of incomplete type %qT will "
1186 "not be accessed in left operand of comma operator",
1190 warning_at (loc
, 0, "variable %qE of incomplete type %qT will "
1191 "not be accessed in statement", expr
, type
);
1193 case ICV_THIRD_IN_FOR
:
1194 warning_at (loc
, 0, "variable %qE of incomplete type %qT will "
1195 "not be accessed in for increment expression",
1206 /* Don't bother with the temporary object returned from a function if
1207 we don't use it and don't need to destroy it. We'll still
1208 allocate space for it in expand_call or declare_return_variable,
1209 but we don't need to track it through all the tree phases. */
1210 if (TARGET_EXPR_IMPLICIT_P (expr
)
1211 && TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (expr
)))
1213 tree init
= TARGET_EXPR_INITIAL (expr
);
1214 if (TREE_CODE (init
) == AGGR_INIT_EXPR
1215 && !AGGR_INIT_VIA_CTOR_P (init
))
1217 tree fn
= AGGR_INIT_EXPR_FN (init
);
1218 expr
= build_call_array_loc (input_location
,
1219 TREE_TYPE (TREE_TYPE (TREE_TYPE (fn
))),
1221 aggr_init_expr_nargs (init
),
1222 AGGR_INIT_EXPR_ARGP (init
));
1229 expr
= resolve_nondeduced_context (expr
);
1233 if (TREE_CODE (probe
) == ADDR_EXPR
)
1234 probe
= TREE_OPERAND (expr
, 0);
1235 if (type_unknown_p (probe
))
1237 /* [over.over] enumerates the places where we can take the address
1238 of an overloaded function, and this is not one of them. */
1239 if (complain
& tf_error
)
1243 error_at (loc
, "conversion to void "
1244 "cannot resolve address of overloaded function");
1246 case ICV_SECOND_OF_COND
:
1247 error_at (loc
, "second operand of conditional expression "
1248 "cannot resolve address of overloaded function");
1250 case ICV_THIRD_OF_COND
:
1251 error_at (loc
, "third operand of conditional expression "
1252 "cannot resolve address of overloaded function");
1254 case ICV_RIGHT_OF_COMMA
:
1255 error_at (loc
, "right operand of comma operator "
1256 "cannot resolve address of overloaded function");
1258 case ICV_LEFT_OF_COMMA
:
1259 error_at (loc
, "left operand of comma operator "
1260 "cannot resolve address of overloaded function");
1263 error_at (loc
, "statement "
1264 "cannot resolve address of overloaded function");
1266 case ICV_THIRD_IN_FOR
:
1267 error_at (loc
, "for increment expression "
1268 "cannot resolve address of overloaded function");
1272 return error_mark_node
;
1273 expr
= void_zero_node
;
1275 else if (implicit
!= ICV_CAST
&& probe
== expr
&& is_overloaded_fn (probe
))
1277 /* Only warn when there is no &. */
1278 if (complain
& tf_warning
)
1281 case ICV_SECOND_OF_COND
:
1282 warning_at (loc
, OPT_Waddress
,
1283 "second operand of conditional expression "
1284 "is a reference, not call, to function %qE", expr
);
1286 case ICV_THIRD_OF_COND
:
1287 warning_at (loc
, OPT_Waddress
,
1288 "third operand of conditional expression "
1289 "is a reference, not call, to function %qE", expr
);
1291 case ICV_RIGHT_OF_COMMA
:
1292 warning_at (loc
, OPT_Waddress
,
1293 "right operand of comma operator "
1294 "is a reference, not call, to function %qE", expr
);
1296 case ICV_LEFT_OF_COMMA
:
1297 warning_at (loc
, OPT_Waddress
,
1298 "left operand of comma operator "
1299 "is a reference, not call, to function %qE", expr
);
1302 warning_at (loc
, OPT_Waddress
,
1303 "statement is a reference, not call, to function %qE",
1306 case ICV_THIRD_IN_FOR
:
1307 warning_at (loc
, OPT_Waddress
,
1308 "for increment expression "
1309 "is a reference, not call, to function %qE", expr
);
1315 if (TREE_CODE (expr
) == COMPONENT_REF
)
1316 expr
= TREE_OPERAND (expr
, 0);
1320 if (expr
!= error_mark_node
&& !VOID_TYPE_P (TREE_TYPE (expr
)))
1322 if (implicit
!= ICV_CAST
1323 && warn_unused_value
1324 && !TREE_NO_WARNING (expr
)
1325 && !processing_template_decl
)
1327 /* The middle end does not warn about expressions that have
1328 been explicitly cast to void, so we must do so here. */
1329 if (!TREE_SIDE_EFFECTS (expr
)) {
1330 if (complain
& tf_warning
)
1333 case ICV_SECOND_OF_COND
:
1334 warning_at (loc
, OPT_Wunused_value
,
1335 "second operand of conditional expression "
1338 case ICV_THIRD_OF_COND
:
1339 warning_at (loc
, OPT_Wunused_value
,
1340 "third operand of conditional expression "
1343 case ICV_RIGHT_OF_COMMA
:
1344 warning_at (loc
, OPT_Wunused_value
,
1345 "right operand of comma operator has no effect");
1347 case ICV_LEFT_OF_COMMA
:
1348 warning_at (loc
, OPT_Wunused_value
,
1349 "left operand of comma operator has no effect");
1352 warning_at (loc
, OPT_Wunused_value
,
1353 "statement has no effect");
1355 case ICV_THIRD_IN_FOR
:
1356 warning_at (loc
, OPT_Wunused_value
,
1357 "for increment expression has no effect");
1366 enum tree_code code
;
1367 enum tree_code_class tclass
;
1370 /* We might like to warn about (say) "(int) f()", as the
1371 cast has no effect, but the compiler itself will
1372 generate implicit conversions under some
1373 circumstances. (For example a block copy will be
1374 turned into a call to "__builtin_memcpy", with a
1375 conversion of the return value to an appropriate
1376 type.) So, to avoid false positives, we strip
1377 conversions. Do not use STRIP_NOPs because it will
1378 not strip conversions to "void", as that is not a
1379 mode-preserving conversion. */
1380 while (TREE_CODE (e
) == NOP_EXPR
)
1381 e
= TREE_OPERAND (e
, 0);
1383 code
= TREE_CODE (e
);
1384 tclass
= TREE_CODE_CLASS (code
);
1385 if ((tclass
== tcc_comparison
1386 || tclass
== tcc_unary
1387 || (tclass
== tcc_binary
1388 && !(code
== MODIFY_EXPR
1389 || code
== INIT_EXPR
1390 || code
== PREDECREMENT_EXPR
1391 || code
== PREINCREMENT_EXPR
1392 || code
== POSTDECREMENT_EXPR
1393 || code
== POSTINCREMENT_EXPR
)))
1394 && (complain
& tf_warning
))
1395 warning_at (loc
, OPT_Wunused_value
, "value computed is not used");
1398 expr
= build1 (CONVERT_EXPR
, void_type_node
, expr
);
1400 if (! TREE_SIDE_EFFECTS (expr
))
1401 expr
= void_zero_node
;
1405 /* Create an expression whose value is that of EXPR,
1406 converted to type TYPE. The TREE_TYPE of the value
1407 is always TYPE. This function implements all reasonable
1408 conversions; callers should filter out those that are
1409 not permitted by the language being compiled.
1411 Most of this routine is from build_reinterpret_cast.
1413 The back end cannot call cp_convert (what was convert) because
1414 conversions to/from basetypes may involve memory references
1415 (vbases) and adding or subtracting small values (multiple
1416 inheritance), but it calls convert from the constant folding code
1417 on subtrees of already built trees after it has ripped them apart.
1419 Also, if we ever support range variables, we'll probably also have to
1420 do a little bit more work. */
1423 convert (tree type
, tree expr
)
1427 if (type
== error_mark_node
|| expr
== error_mark_node
)
1428 return error_mark_node
;
1430 intype
= TREE_TYPE (expr
);
1432 if (POINTER_TYPE_P (type
) && POINTER_TYPE_P (intype
))
1433 return fold_if_not_in_template (build_nop (type
, expr
));
1435 return ocp_convert (type
, expr
, CONV_OLD_CONVERT
,
1436 LOOKUP_NORMAL
|LOOKUP_NO_CONVERSION
,
1437 tf_warning_or_error
);
1440 /* Like cp_convert, except permit conversions to take place which
1441 are not normally allowed due to access restrictions
1442 (such as conversion from sub-type to private super-type). */
1445 convert_force (tree type
, tree expr
, int convtype
, tsubst_flags_t complain
)
1448 enum tree_code code
= TREE_CODE (type
);
1450 if (code
== REFERENCE_TYPE
)
1451 return (fold_if_not_in_template
1452 (convert_to_reference (type
, e
, CONV_C_CAST
, 0,
1453 NULL_TREE
, complain
)));
1455 if (code
== POINTER_TYPE
)
1456 return fold_if_not_in_template (convert_to_pointer_force (type
, e
,
1459 /* From typeck.c convert_for_assignment */
1460 if (((TREE_CODE (TREE_TYPE (e
)) == POINTER_TYPE
&& TREE_CODE (e
) == ADDR_EXPR
1461 && TREE_CODE (TREE_TYPE (e
)) == POINTER_TYPE
1462 && TREE_CODE (TREE_TYPE (TREE_TYPE (e
))) == METHOD_TYPE
)
1463 || integer_zerop (e
)
1464 || TYPE_PTRMEMFUNC_P (TREE_TYPE (e
)))
1465 && TYPE_PTRMEMFUNC_P (type
))
1466 /* compatible pointer to member functions. */
1467 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type
), e
, 1,
1468 /*c_cast_p=*/1, complain
);
1470 return ocp_convert (type
, e
, CONV_C_CAST
|convtype
, LOOKUP_NORMAL
, complain
);
1473 /* Convert an aggregate EXPR to type XTYPE. If a conversion
1474 exists, return the attempted conversion. This may
1475 return ERROR_MARK_NODE if the conversion is not
1476 allowed (references private members, etc).
1477 If no conversion exists, NULL_TREE is returned.
1479 FIXME: Ambiguity checking is wrong. Should choose one by the implicit
1480 object parameter, or by the second standard conversion sequence if
1481 that doesn't do it. This will probably wait for an overloading rewrite.
1485 build_type_conversion (tree xtype
, tree expr
)
1487 /* C++: check to see if we can convert this aggregate type
1488 into the required type. */
1489 return build_user_type_conversion (xtype
, expr
, LOOKUP_NORMAL
,
1490 tf_warning_or_error
);
1493 /* Convert the given EXPR to one of a group of types suitable for use in an
1494 expression. DESIRES is a combination of various WANT_* flags (q.v.)
1495 which indicates which types are suitable. If COMPLAIN is true, complain
1496 about ambiguity; otherwise, the caller will deal with it. */
1499 build_expr_type_conversion (int desires
, tree expr
, bool complain
)
1501 tree basetype
= TREE_TYPE (expr
);
1502 tree conv
= NULL_TREE
;
1503 tree winner
= NULL_TREE
;
1505 if (expr
== null_node
1506 && (desires
& WANT_INT
)
1507 && !(desires
& WANT_NULL
))
1509 source_location loc
=
1510 expansion_point_location_if_in_system_header (input_location
);
1512 warning_at (loc
, OPT_Wconversion_null
,
1513 "converting NULL to non-pointer type");
1516 if (basetype
== error_mark_node
)
1517 return error_mark_node
;
1519 if (! MAYBE_CLASS_TYPE_P (basetype
))
1520 switch (TREE_CODE (basetype
))
1523 if ((desires
& WANT_NULL
) && null_ptr_cst_p (expr
))
1525 /* else fall through... */
1528 return (desires
& WANT_INT
) ? expr
: NULL_TREE
;
1530 return (desires
& WANT_ENUM
) ? expr
: NULL_TREE
;
1532 return (desires
& WANT_FLOAT
) ? expr
: NULL_TREE
;
1534 return (desires
& WANT_POINTER
) ? expr
: NULL_TREE
;
1538 return (desires
& WANT_POINTER
) ? decay_conversion (expr
,
1539 tf_warning_or_error
)
1544 if ((desires
& WANT_VECTOR_OR_COMPLEX
) == 0)
1546 switch (TREE_CODE (TREE_TYPE (basetype
)))
1550 return (desires
& WANT_INT
) ? expr
: NULL_TREE
;
1552 return (desires
& WANT_ENUM
) ? expr
: NULL_TREE
;
1554 return (desires
& WANT_FLOAT
) ? expr
: NULL_TREE
;
1563 /* The code for conversions from class type is currently only used for
1564 delete expressions. Other expressions are handled by build_new_op. */
1565 if (!complete_type_or_maybe_complain (basetype
, expr
, complain
))
1566 return error_mark_node
;
1567 if (!TYPE_HAS_CONVERSION (basetype
))
1570 for (conv
= lookup_conversions (basetype
); conv
; conv
= TREE_CHAIN (conv
))
1574 tree cand
= TREE_VALUE (conv
);
1575 cand
= OVL_CURRENT (cand
);
1577 if (winner
&& winner
== cand
)
1580 if (DECL_NONCONVERTING_P (cand
))
1583 if (TREE_CODE (cand
) == TEMPLATE_DECL
)
1587 error ("ambiguous default type conversion from %qT",
1589 error (" candidate conversions include %qD", cand
);
1591 return error_mark_node
;
1594 candidate
= non_reference (TREE_TYPE (TREE_TYPE (cand
)));
1596 switch (TREE_CODE (candidate
))
1600 win
= (desires
& WANT_INT
); break;
1602 win
= (desires
& WANT_ENUM
); break;
1604 win
= (desires
& WANT_FLOAT
); break;
1606 win
= (desires
& WANT_POINTER
); break;
1610 if ((desires
& WANT_VECTOR_OR_COMPLEX
) == 0)
1612 switch (TREE_CODE (TREE_TYPE (candidate
)))
1616 win
= (desires
& WANT_INT
); break;
1618 win
= (desires
& WANT_ENUM
); break;
1620 win
= (desires
& WANT_FLOAT
); break;
1636 error ("ambiguous default type conversion from %qT",
1638 error (" candidate conversions include %qD and %qD",
1641 return error_mark_node
;
1650 tree type
= non_reference (TREE_TYPE (TREE_TYPE (winner
)));
1651 return build_user_type_conversion (type
, expr
, LOOKUP_NORMAL
,
1652 tf_warning_or_error
);
1658 /* Implements integral promotion (4.1) and float->double promotion. */
1661 type_promotes_to (tree type
)
1665 if (type
== error_mark_node
)
1666 return error_mark_node
;
1668 type
= TYPE_MAIN_VARIANT (type
);
1670 /* Check for promotions of target-defined types first. */
1671 promoted_type
= targetm
.promoted_type (type
);
1673 return promoted_type
;
1675 /* bool always promotes to int (not unsigned), even if it's the same
1677 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
1678 type
= integer_type_node
;
1680 /* Scoped enums don't promote, but pretend they do for backward ABI bug
1681 compatibility wrt varargs. */
1682 else if (SCOPED_ENUM_P (type
) && abi_version_at_least (6))
1685 /* Normally convert enums to int, but convert wide enums to something
1687 else if (TREE_CODE (type
) == ENUMERAL_TYPE
1688 || type
== char16_type_node
1689 || type
== char32_type_node
1690 || type
== wchar_type_node
)
1692 int precision
= MAX (TYPE_PRECISION (type
),
1693 TYPE_PRECISION (integer_type_node
));
1694 tree totype
= c_common_type_for_size (precision
, 0);
1695 if (SCOPED_ENUM_P (type
))
1696 warning (OPT_Wabi
, "scoped enum %qT will not promote to an integral "
1697 "type in a future version of GCC", type
);
1698 if (TREE_CODE (type
) == ENUMERAL_TYPE
)
1699 type
= ENUM_UNDERLYING_TYPE (type
);
1700 if (TYPE_UNSIGNED (type
)
1701 && ! int_fits_type_p (TYPE_MAX_VALUE (type
), totype
))
1702 type
= c_common_type_for_size (precision
, 1);
1706 else if (c_promoting_integer_type_p (type
))
1708 /* Retain unsignedness if really not getting bigger. */
1709 if (TYPE_UNSIGNED (type
)
1710 && TYPE_PRECISION (type
) == TYPE_PRECISION (integer_type_node
))
1711 type
= unsigned_type_node
;
1713 type
= integer_type_node
;
1715 else if (type
== float_type_node
)
1716 type
= double_type_node
;
1721 /* The routines below this point are carefully written to conform to
1722 the standard. They use the same terminology, and follow the rules
1723 closely. Although they are used only in pt.c at the moment, they
1724 should presumably be used everywhere in the future. */
1726 /* Attempt to perform qualification conversions on EXPR to convert it
1727 to TYPE. Return the resulting expression, or error_mark_node if
1728 the conversion was impossible. */
1731 perform_qualification_conversions (tree type
, tree expr
)
1735 expr_type
= TREE_TYPE (expr
);
1737 if (same_type_p (type
, expr_type
))
1739 else if (TYPE_PTR_P (type
) && TYPE_PTR_P (expr_type
)
1740 && comp_ptr_ttypes (TREE_TYPE (type
), TREE_TYPE (expr_type
)))
1741 return build_nop (type
, expr
);
1742 else if (TYPE_PTRMEM_P (type
) && TYPE_PTRMEM_P (expr_type
)
1743 && same_type_p (TYPE_PTRMEM_CLASS_TYPE (type
),
1744 TYPE_PTRMEM_CLASS_TYPE (expr_type
))
1745 && comp_ptr_ttypes (TYPE_PTRMEM_POINTED_TO_TYPE (type
),
1746 TYPE_PTRMEM_POINTED_TO_TYPE (expr_type
)))
1747 return build_nop (type
, expr
);
1749 return error_mark_node
;