1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@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 2, or (at your option)
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 COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
46 static tree pfn_from_ptrmemfunc (tree);
47 static tree convert_for_assignment (tree, tree, const char *, tree, int);
48 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
49 static tree rationalize_conditional_expr (enum tree_code, tree);
50 static int comp_ptr_ttypes_real (tree, tree, int);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
60 /* APPLE LOCAL radar 6087117 */
61 static tree convert_arguments (tree, tree, tree, int, int);
63 /* Do `exp = require_complete_type (exp);' to make sure exp
64 does not have an incomplete type. (That includes void types.)
65 Returns the error_mark_node if the VALUE does not have
66 complete type when this function returns. */
69 require_complete_type (tree value)
73 if (processing_template_decl || value == error_mark_node)
76 if (TREE_CODE (value) == OVERLOAD)
77 type = unknown_type_node;
79 type = TREE_TYPE (value);
81 if (type == error_mark_node)
82 return error_mark_node;
84 /* First, detect a valid value with a complete type. */
85 if (COMPLETE_TYPE_P (type))
88 if (complete_type_or_else (type, value))
91 return error_mark_node;
94 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
95 a template instantiation, do the instantiation. Returns TYPE,
96 whether or not it could be completed, unless something goes
97 horribly wrong, in which case the error_mark_node is returned. */
100 complete_type (tree type)
102 if (type == NULL_TREE)
103 /* Rather than crash, we return something sure to cause an error
105 return error_mark_node;
107 if (type == error_mark_node || COMPLETE_TYPE_P (type))
109 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
111 tree t = complete_type (TREE_TYPE (type));
112 unsigned int needs_constructing, has_nontrivial_dtor;
113 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
116 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
118 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
119 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
121 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
122 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
125 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
126 instantiate_class_template (TYPE_MAIN_VARIANT (type));
131 /* Like complete_type, but issue an error if the TYPE cannot be completed.
132 VALUE is used for informative diagnostics.
133 Returns NULL_TREE if the type cannot be made complete. */
136 complete_type_or_else (tree type, tree value)
138 type = complete_type (type);
139 if (type == error_mark_node)
140 /* We already issued an error. */
142 else if (!COMPLETE_TYPE_P (type))
144 cxx_incomplete_type_diagnostic (value, type, 0);
151 /* Return truthvalue of whether type of EXP is instantiated. */
154 type_unknown_p (tree exp)
156 return (TREE_CODE (exp) == TREE_LIST
157 || TREE_TYPE (exp) == unknown_type_node);
161 /* Return the common type of two parameter lists.
162 We assume that comptypes has already been done and returned 1;
163 if that isn't so, this may crash.
165 As an optimization, free the space we allocate if the parameter
166 lists are already common. */
169 commonparms (tree p1, tree p2)
171 tree oldargs = p1, newargs, n;
175 len = list_length (p1);
176 newargs = tree_last (p1);
178 if (newargs == void_list_node)
187 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
192 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
194 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
196 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
199 else if (! TREE_PURPOSE (p1))
201 if (TREE_PURPOSE (p2))
203 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
209 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
211 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
213 if (TREE_VALUE (p1) != TREE_VALUE (p2))
216 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
219 TREE_VALUE (n) = TREE_VALUE (p1);
227 /* Given a type, perhaps copied for a typedef,
228 find the "original" version of it. */
230 original_type (tree t)
232 int quals = cp_type_quals (t);
233 while (t != error_mark_node
234 && TYPE_NAME (t) != NULL_TREE)
236 tree x = TYPE_NAME (t);
237 if (TREE_CODE (x) != TYPE_DECL)
239 x = DECL_ORIGINAL_TYPE (x);
244 return cp_build_qualified_type (t, quals);
247 /* T1 and T2 are arithmetic or enumeration types. Return the type
248 that will result from the "usual arithmetic conversions" on T1 and
249 T2 as described in [expr]. */
252 type_after_usual_arithmetic_conversions (tree t1, tree t2)
254 enum tree_code code1 = TREE_CODE (t1);
255 enum tree_code code2 = TREE_CODE (t2);
258 /* FIXME: Attributes. */
259 gcc_assert (ARITHMETIC_TYPE_P (t1)
260 || TREE_CODE (t1) == VECTOR_TYPE
261 || TREE_CODE (t1) == ENUMERAL_TYPE);
262 gcc_assert (ARITHMETIC_TYPE_P (t2)
263 || TREE_CODE (t2) == VECTOR_TYPE
264 || TREE_CODE (t2) == ENUMERAL_TYPE);
266 /* In what follows, we slightly generalize the rules given in [expr] so
267 as to deal with `long long' and `complex'. First, merge the
269 attributes = (*targetm.merge_type_attributes) (t1, t2);
271 /* If one type is complex, form the common type of the non-complex
272 components, then make that complex. Use T1 or T2 if it is the
274 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
276 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
277 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
279 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
281 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
282 return build_type_attribute_variant (t1, attributes);
283 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
284 return build_type_attribute_variant (t2, attributes);
286 return build_type_attribute_variant (build_complex_type (subtype),
290 if (code1 == VECTOR_TYPE)
292 /* When we get here we should have two vectors of the same size.
293 Just prefer the unsigned one if present. */
294 if (TYPE_UNSIGNED (t1))
295 return build_type_attribute_variant (t1, attributes);
297 return build_type_attribute_variant (t2, attributes);
300 /* If only one is real, use it as the result. */
301 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
302 return build_type_attribute_variant (t1, attributes);
303 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
304 return build_type_attribute_variant (t2, attributes);
306 /* Perform the integral promotions. */
307 if (code1 != REAL_TYPE)
309 t1 = type_promotes_to (t1);
310 t2 = type_promotes_to (t2);
313 /* Both real or both integers; use the one with greater precision. */
314 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
315 return build_type_attribute_variant (t1, attributes);
316 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
317 return build_type_attribute_variant (t2, attributes);
319 /* The types are the same; no need to do anything fancy. */
320 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
321 return build_type_attribute_variant (t1, attributes);
323 if (code1 != REAL_TYPE)
325 /* If one is a sizetype, use it so size_binop doesn't blow up. */
326 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
327 return build_type_attribute_variant (t1, attributes);
328 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
329 return build_type_attribute_variant (t2, attributes);
331 /* If one is unsigned long long, then convert the other to unsigned
333 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
334 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
335 return build_type_attribute_variant (long_long_unsigned_type_node,
337 /* If one is a long long, and the other is an unsigned long, and
338 long long can represent all the values of an unsigned long, then
339 convert to a long long. Otherwise, convert to an unsigned long
340 long. Otherwise, if either operand is long long, convert the
343 Since we're here, we know the TYPE_PRECISION is the same;
344 therefore converting to long long cannot represent all the values
345 of an unsigned long, so we choose unsigned long long in that
347 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
348 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
350 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
351 ? long_long_unsigned_type_node
352 : long_long_integer_type_node);
353 return build_type_attribute_variant (t, attributes);
356 /* Go through the same procedure, but for longs. */
357 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
358 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
359 return build_type_attribute_variant (long_unsigned_type_node,
361 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
362 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
364 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
365 ? long_unsigned_type_node : long_integer_type_node);
366 return build_type_attribute_variant (t, attributes);
368 /* Otherwise prefer the unsigned one. */
369 if (TYPE_UNSIGNED (t1))
370 return build_type_attribute_variant (t1, attributes);
372 return build_type_attribute_variant (t2, attributes);
376 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
377 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
378 return build_type_attribute_variant (long_double_type_node,
380 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
381 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
382 return build_type_attribute_variant (double_type_node,
384 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
385 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
386 return build_type_attribute_variant (float_type_node,
389 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
390 the standard C++ floating-point types. Logic earlier in this
391 function has already eliminated the possibility that
392 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
393 compelling reason to choose one or the other. */
394 return build_type_attribute_variant (t1, attributes);
398 /* Subroutine of composite_pointer_type to implement the recursive
399 case. See that function for documentation fo the parameters. */
402 composite_pointer_type_r (tree t1, tree t2, const char* location)
409 /* Determine the types pointed to by T1 and T2. */
410 /* APPLE LOCAL blocks 6040305 */
411 if (TREE_CODE (t1) == POINTER_TYPE || TREE_CODE (t1) == BLOCK_POINTER_TYPE)
413 pointee1 = TREE_TYPE (t1);
414 pointee2 = TREE_TYPE (t2);
418 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
419 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
424 Otherwise, the composite pointer type is a pointer type
425 similar (_conv.qual_) to the type of one of the operands,
426 with a cv-qualification signature (_conv.qual_) that is the
427 union of the cv-qualification signatures of the operand
429 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
430 result_type = pointee1;
431 else if ((TREE_CODE (pointee1) == POINTER_TYPE
432 && TREE_CODE (pointee2) == POINTER_TYPE)
433 || (TYPE_PTR_TO_MEMBER_P (pointee1)
434 && TYPE_PTR_TO_MEMBER_P (pointee2)))
435 result_type = composite_pointer_type_r (pointee1, pointee2, location);
438 pedwarn ("%s between distinct pointer types %qT and %qT "
441 result_type = void_type_node;
443 result_type = cp_build_qualified_type (result_type,
444 (cp_type_quals (pointee1)
445 | cp_type_quals (pointee2)));
446 /* If the original types were pointers to members, so is the
448 if (TYPE_PTR_TO_MEMBER_P (t1))
450 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
451 TYPE_PTRMEM_CLASS_TYPE (t2)))
452 pedwarn ("%s between distinct pointer types %qT and %qT "
455 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
458 /* APPLE LOCAL begin blocks 6065211 */
459 else if (TREE_CODE (t1) == BLOCK_POINTER_TYPE
460 && result_type != void_type_node)
461 result_type = build_block_pointer_type (result_type);
463 result_type = build_pointer_type (result_type);
464 /* APPLE LOCAL end blocks 6065211 */
466 /* Merge the attributes. */
467 attributes = (*targetm.merge_type_attributes) (t1, t2);
468 return build_type_attribute_variant (result_type, attributes);
471 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
472 ARG1 and ARG2 are the values with those types. The LOCATION is a
473 string describing the current location, in case an error occurs.
475 This routine also implements the computation of a common type for
476 pointers-to-members as per [expr.eq]. */
479 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
480 const char* location)
487 If one operand is a null pointer constant, the composite pointer
488 type is the type of the other operand. */
489 if (null_ptr_cst_p (arg1))
491 if (null_ptr_cst_p (arg2))
498 If one of the operands has type "pointer to cv1 void*", then
499 the other has type "pointer to cv2T", and the composite pointer
500 type is "pointer to cv12 void", where cv12 is the union of cv1
503 If either type is a pointer to void, make sure it is T1. */
504 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
512 /* Now, if T1 is a pointer to void, merge the qualifiers. */
513 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
518 if (pedantic && TYPE_PTRFN_P (t2))
519 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
520 "and pointer-to-function", location);
522 = cp_build_qualified_type (void_type_node,
523 (cp_type_quals (TREE_TYPE (t1))
524 | cp_type_quals (TREE_TYPE (t2))));
525 result_type = build_pointer_type (result_type);
526 /* Merge the attributes. */
527 attributes = (*targetm.merge_type_attributes) (t1, t2);
528 return build_type_attribute_variant (result_type, attributes);
531 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
532 && TREE_CODE (t2) == POINTER_TYPE)
534 /* APPLE LOCAL radar 4229905 - radar 6231433 */
535 if (objc_have_common_type (t1, t2, -3, NULL_TREE, location))
536 /* APPLE LOCAL 4154928 */
537 return objc_common_type (t1, t2);
540 /* [expr.eq] permits the application of a pointer conversion to
541 bring the pointers to a common type. */
542 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
543 && CLASS_TYPE_P (TREE_TYPE (t1))
544 && CLASS_TYPE_P (TREE_TYPE (t2))
545 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
548 class1 = TREE_TYPE (t1);
549 class2 = TREE_TYPE (t2);
551 if (DERIVED_FROM_P (class1, class2))
552 t2 = (build_pointer_type
553 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
554 else if (DERIVED_FROM_P (class2, class1))
555 t1 = (build_pointer_type
556 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
559 error ("%s between distinct pointer types %qT and %qT "
560 "lacks a cast", location, t1, t2);
561 return error_mark_node;
564 /* [expr.eq] permits the application of a pointer-to-member
565 conversion to change the class type of one of the types. */
566 else if (TYPE_PTR_TO_MEMBER_P (t1)
567 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
568 TYPE_PTRMEM_CLASS_TYPE (t2)))
570 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
571 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
573 if (DERIVED_FROM_P (class1, class2))
574 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
575 else if (DERIVED_FROM_P (class2, class1))
576 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
579 error ("%s between distinct pointer-to-member types %qT and %qT "
580 "lacks a cast", location, t1, t2);
581 return error_mark_node;
584 /* APPLE LOCAL begin blocks 6065211 */
585 else if (TREE_CODE (t1) != TREE_CODE (t2))
587 error ("%s between distinct pointer types %qT and %qT "
588 "lacks a cast", location, t1, t2);
589 return error_mark_node;
591 /* APPLE LOCAL end blocks 6065211 */
593 return composite_pointer_type_r (t1, t2, location);
596 /* Return the merged type of two types.
597 We assume that comptypes has already been done and returned 1;
598 if that isn't so, this may crash.
600 This just combines attributes and default arguments; any other
601 differences would cause the two types to compare unalike. */
604 merge_types (tree t1, tree t2)
606 enum tree_code code1;
607 enum tree_code code2;
610 /* Save time if the two types are the same. */
613 if (original_type (t1) == original_type (t2))
616 /* If one type is nonsense, use the other. */
617 if (t1 == error_mark_node)
619 if (t2 == error_mark_node)
622 /* Merge the attributes. */
623 attributes = (*targetm.merge_type_attributes) (t1, t2);
625 if (TYPE_PTRMEMFUNC_P (t1))
626 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
627 if (TYPE_PTRMEMFUNC_P (t2))
628 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
630 code1 = TREE_CODE (t1);
631 code2 = TREE_CODE (t2);
637 /* For two pointers, do this recursively on the target type. */
639 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
640 int quals = cp_type_quals (t1);
642 if (code1 == POINTER_TYPE)
643 t1 = build_pointer_type (target);
645 t1 = build_reference_type (target);
646 t1 = build_type_attribute_variant (t1, attributes);
647 t1 = cp_build_qualified_type (t1, quals);
649 if (TREE_CODE (target) == METHOD_TYPE)
650 t1 = build_ptrmemfunc_type (t1);
659 quals = cp_type_quals (t1);
660 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
661 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
662 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
664 t1 = cp_build_qualified_type (t1, quals);
670 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
671 /* Save space: see if the result is identical to one of the args. */
672 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
673 return build_type_attribute_variant (t1, attributes);
674 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
675 return build_type_attribute_variant (t2, attributes);
676 /* Merge the element types, and have a size if either arg has one. */
677 t1 = build_cplus_array_type
678 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
683 /* Function types: prefer the one that specified arg types.
684 If both do, merge the arg types. Also merge the return types. */
686 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
687 tree p1 = TYPE_ARG_TYPES (t1);
688 tree p2 = TYPE_ARG_TYPES (t2);
691 /* Save space: see if the result is identical to one of the args. */
692 if (valtype == TREE_TYPE (t1) && ! p2)
693 return cp_build_type_attribute_variant (t1, attributes);
694 if (valtype == TREE_TYPE (t2) && ! p1)
695 return cp_build_type_attribute_variant (t2, attributes);
697 /* Simple way if one arg fails to specify argument types. */
698 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
700 rval = build_function_type (valtype, p2);
701 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
702 rval = build_exception_variant (rval, raises);
703 return cp_build_type_attribute_variant (rval, attributes);
705 raises = TYPE_RAISES_EXCEPTIONS (t1);
706 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
708 rval = build_function_type (valtype, p1);
710 rval = build_exception_variant (rval, raises);
711 return cp_build_type_attribute_variant (rval, attributes);
714 rval = build_function_type (valtype, commonparms (p1, p2));
715 t1 = build_exception_variant (rval, raises);
721 /* Get this value the long way, since TYPE_METHOD_BASETYPE
722 is just the main variant of this. */
723 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
724 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
727 /* If this was a member function type, get back to the
728 original type of type member function (i.e., without
729 the class instance variable up front. */
730 t1 = build_function_type (TREE_TYPE (t1),
731 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
732 t2 = build_function_type (TREE_TYPE (t2),
733 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
734 t3 = merge_types (t1, t2);
735 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
736 TYPE_ARG_TYPES (t3));
737 t1 = build_exception_variant (t3, raises);
742 /* There is no need to merge attributes into a TYPENAME_TYPE.
743 When the type is instantiated it will have whatever
744 attributes result from the instantiation. */
750 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
752 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
755 return cp_build_type_attribute_variant (t1, attributes);
758 /* Return the common type of two types.
759 We assume that comptypes has already been done and returned 1;
760 if that isn't so, this may crash.
762 This is the type for the result of most arithmetic operations
763 if the operands have the given two types. */
766 common_type (tree t1, tree t2)
768 enum tree_code code1;
769 enum tree_code code2;
771 /* If one type is nonsense, bail. */
772 if (t1 == error_mark_node || t2 == error_mark_node)
773 return error_mark_node;
775 code1 = TREE_CODE (t1);
776 code2 = TREE_CODE (t2);
778 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
779 || code1 == VECTOR_TYPE)
780 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
781 || code2 == VECTOR_TYPE))
782 return type_after_usual_arithmetic_conversions (t1, t2);
784 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
785 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
786 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
787 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
793 /* Compare two exception specifier types for exactness or subsetness, if
794 allowed. Returns false for mismatch, true for match (same, or
797 [except.spec] "If a class X ... objects of class X or any class publicly
798 and unambiguously derived from X. Similarly, if a pointer type Y * ...
799 exceptions of type Y * or that are pointers to any type publicly and
800 unambiguously derived from Y. Otherwise a function only allows exceptions
801 that have the same type ..."
802 This does not mention cv qualifiers and is different to what throw
803 [except.throw] and catch [except.catch] will do. They will ignore the
804 top level cv qualifiers, and allow qualifiers in the pointer to class
807 We implement the letter of the standard. */
810 comp_except_types (tree a, tree b, bool exact)
812 if (same_type_p (a, b))
816 if (cp_type_quals (a) || cp_type_quals (b))
819 if (TREE_CODE (a) == POINTER_TYPE
820 && TREE_CODE (b) == POINTER_TYPE)
824 if (cp_type_quals (a) || cp_type_quals (b))
828 if (TREE_CODE (a) != RECORD_TYPE
829 || TREE_CODE (b) != RECORD_TYPE)
832 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
838 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
839 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
840 otherwise it must be exact. Exception lists are unordered, but
841 we've already filtered out duplicates. Most lists will be in order,
842 we should try to make use of that. */
845 comp_except_specs (tree t1, tree t2, bool exact)
854 if (t1 == NULL_TREE) /* T1 is ... */
855 return t2 == NULL_TREE || !exact;
856 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
857 return t2 != NULL_TREE && !TREE_VALUE (t2);
858 if (t2 == NULL_TREE) /* T2 is ... */
860 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
863 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
864 Count how many we find, to determine exactness. For exact matching and
865 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
867 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
869 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
871 tree a = TREE_VALUE (probe);
872 tree b = TREE_VALUE (t2);
874 if (comp_except_types (a, b, exact))
876 if (probe == base && exact)
877 base = TREE_CHAIN (probe);
882 if (probe == NULL_TREE)
885 return !exact || base == NULL_TREE || length == list_length (t1);
888 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
889 [] can match [size]. */
892 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
901 /* The type of the array elements must be the same. */
902 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
905 d1 = TYPE_DOMAIN (t1);
906 d2 = TYPE_DOMAIN (t2);
911 /* If one of the arrays is dimensionless, and the other has a
912 dimension, they are of different types. However, it is valid to
920 declarations for an array object can specify
921 array types that differ by the presence or absence of a major
922 array bound (_dcl.array_). */
924 return allow_redeclaration;
926 /* Check that the dimensions are the same. */
928 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
930 max1 = TYPE_MAX_VALUE (d1);
931 max2 = TYPE_MAX_VALUE (d2);
932 if (processing_template_decl && !abi_version_at_least (2)
933 && !value_dependent_expression_p (max1)
934 && !value_dependent_expression_p (max2))
936 /* With abi-1 we do not fold non-dependent array bounds, (and
937 consequently mangle them incorrectly). We must therefore
938 fold them here, to verify the domains have the same
944 if (!cp_tree_equal (max1, max2))
950 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
951 is a bitwise-or of the COMPARE_* flags. */
954 comptypes (tree t1, tree t2, int strict)
959 /* Suppress errors caused by previously reported errors. */
960 if (t1 == error_mark_node || t2 == error_mark_node)
963 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
965 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
966 current instantiation. */
967 if (TREE_CODE (t1) == TYPENAME_TYPE)
969 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
971 if (resolved != error_mark_node)
975 if (TREE_CODE (t2) == TYPENAME_TYPE)
977 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
979 if (resolved != error_mark_node)
983 /* If either type is the internal version of sizetype, use the
985 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
986 && TYPE_ORIG_SIZE_TYPE (t1))
987 t1 = TYPE_ORIG_SIZE_TYPE (t1);
989 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
990 && TYPE_ORIG_SIZE_TYPE (t2))
991 t2 = TYPE_ORIG_SIZE_TYPE (t2);
993 if (TYPE_PTRMEMFUNC_P (t1))
994 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
995 if (TYPE_PTRMEMFUNC_P (t2))
996 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
998 /* Different classes of types can't be compatible. */
999 if (TREE_CODE (t1) != TREE_CODE (t2))
1002 /* Qualifiers must match. For array types, we will check when we
1003 recur on the array element types. */
1004 if (TREE_CODE (t1) != ARRAY_TYPE
1005 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
1007 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
1010 /* Allow for two different type nodes which have essentially the same
1011 definition. Note that we already checked for equality of the type
1012 qualifiers (just above). */
1014 if (TREE_CODE (t1) != ARRAY_TYPE
1015 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
1018 /* Compare the types. Break out if they could be the same. */
1019 switch (TREE_CODE (t1))
1021 case TEMPLATE_TEMPLATE_PARM:
1022 case BOUND_TEMPLATE_TEMPLATE_PARM:
1023 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1024 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1026 if (!comp_template_parms
1027 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1028 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1030 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1032 /* Don't check inheritance. */
1033 strict = COMPARE_STRICT;
1038 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1039 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1040 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1041 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1044 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1046 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1052 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1053 strict & ~COMPARE_REDECLARATION))
1055 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1059 /* APPLE LOCAL begin blocks 6040305 */
1060 case BLOCK_POINTER_TYPE:
1061 if (TREE_CODE (t2) == BLOCK_POINTER_TYPE)
1063 tree pt1 = TREE_TYPE (t1);
1064 tree pt2 = TREE_TYPE (t2);
1065 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (pt1),
1068 if (!compparms (TYPE_ARG_TYPES (pt1), TYPE_ARG_TYPES (pt2)))
1072 /* APPLE LOCAL end blocks 6040305 */
1075 case REFERENCE_TYPE:
1076 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1077 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1078 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1084 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1086 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1091 /* Target types must match incl. qualifiers. */
1092 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1096 case TEMPLATE_TYPE_PARM:
1097 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1098 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1103 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1104 TYPENAME_TYPE_FULLNAME (t2)))
1106 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1110 case UNBOUND_CLASS_TEMPLATE:
1111 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1113 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1118 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1123 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1124 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1132 /* If we get here, we know that from a target independent POV the
1133 types are the same. Make sure the target attributes are also
1135 return targetm.comp_type_attributes (t1, t2);
1138 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1141 at_least_as_qualified_p (tree type1, tree type2)
1143 int q1 = cp_type_quals (type1);
1144 int q2 = cp_type_quals (type2);
1146 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1147 return (q1 & q2) == q2;
1150 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1151 more cv-qualified that TYPE1, and 0 otherwise. */
1154 comp_cv_qualification (tree type1, tree type2)
1156 int q1 = cp_type_quals (type1);
1157 int q2 = cp_type_quals (type2);
1162 if ((q1 & q2) == q2)
1164 else if ((q1 & q2) == q1)
1170 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1171 subset of the cv-qualification signature of TYPE2, and the types
1172 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1175 comp_cv_qual_signature (tree type1, tree type2)
1177 if (comp_ptr_ttypes_real (type2, type1, -1))
1179 else if (comp_ptr_ttypes_real (type1, type2, -1))
1185 /* If two types share a common base type, return that basetype.
1186 If there is not a unique most-derived base type, this function
1187 returns ERROR_MARK_NODE. */
1190 common_base_type (tree tt1, tree tt2)
1192 tree best = NULL_TREE;
1195 /* If one is a baseclass of another, that's good enough. */
1196 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1198 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1201 /* Otherwise, try to find a unique baseclass of TT1
1202 that is shared by TT2, and follow that down. */
1203 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1205 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1206 tree trial = common_base_type (basetype, tt2);
1210 if (trial == error_mark_node)
1212 if (best == NULL_TREE)
1214 else if (best != trial)
1215 return error_mark_node;
1220 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1222 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1223 tree trial = common_base_type (tt1, basetype);
1227 if (trial == error_mark_node)
1229 if (best == NULL_TREE)
1231 else if (best != trial)
1232 return error_mark_node;
1238 /* Subroutines of `comptypes'. */
1240 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1241 equivalent in the sense that functions with those parameter types
1242 can have equivalent types. The two lists must be equivalent,
1243 element by element. */
1246 compparms (tree parms1, tree parms2)
1250 /* An unspecified parmlist matches any specified parmlist
1251 whose argument types don't need default promotions. */
1253 for (t1 = parms1, t2 = parms2;
1255 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1257 /* If one parmlist is shorter than the other,
1258 they fail to match. */
1261 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1268 /* Process a sizeof or alignof expression where the operand is a
1272 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1277 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1278 if (type == error_mark_node)
1279 return error_mark_node;
1281 type = non_reference (type);
1282 if (TREE_CODE (type) == METHOD_TYPE)
1284 if (complain && (pedantic || warn_pointer_arith))
1285 pedwarn ("invalid application of %qs to a member function",
1286 operator_name_info[(int) op].name);
1287 value = size_one_node;
1290 dependent_p = dependent_type_p (type);
1292 complete_type (type);
1294 /* VLA types will have a non-constant size. In the body of an
1295 uninstantiated template, we don't need to try to compute the
1296 value, because the sizeof expression is not an integral
1297 constant expression in that case. And, if we do try to
1298 compute the value, we'll likely end up with SAVE_EXPRs, which
1299 the template substitution machinery does not expect to see. */
1300 || (processing_template_decl
1301 && COMPLETE_TYPE_P (type)
1302 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1304 value = build_min (op, size_type_node, type);
1305 TREE_READONLY (value) = 1;
1309 return c_sizeof_or_alignof_type (complete_type (type),
1314 /* Process a sizeof expression where the operand is an expression. */
1317 cxx_sizeof_expr (tree e)
1319 if (e == error_mark_node)
1320 return error_mark_node;
1322 if (processing_template_decl)
1324 e = build_min (SIZEOF_EXPR, size_type_node, e);
1325 TREE_SIDE_EFFECTS (e) = 0;
1326 TREE_READONLY (e) = 1;
1331 if (TREE_CODE (e) == COMPONENT_REF
1332 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1333 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1335 error ("invalid application of %<sizeof%> to a bit-field");
1338 else if (is_overloaded_fn (e))
1340 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1344 else if (type_unknown_p (e))
1346 cxx_incomplete_type_error (e, TREE_TYPE (e));
1352 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1355 /* Implement the __alignof keyword: Return the minimum required
1356 alignment of E, measured in bytes. For VAR_DECL's and
1357 FIELD_DECL's return DECL_ALIGN (which can be set from an
1358 "aligned" __attribute__ specification). */
1361 cxx_alignof_expr (tree e)
1365 if (e == error_mark_node)
1366 return error_mark_node;
1368 if (processing_template_decl)
1370 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1371 TREE_SIDE_EFFECTS (e) = 0;
1372 TREE_READONLY (e) = 1;
1377 if (TREE_CODE (e) == VAR_DECL)
1378 t = size_int (DECL_ALIGN_UNIT (e));
1379 else if (TREE_CODE (e) == COMPONENT_REF
1380 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1381 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1383 error ("invalid application of %<__alignof%> to a bit-field");
1386 else if (TREE_CODE (e) == COMPONENT_REF
1387 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1388 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1389 else if (is_overloaded_fn (e))
1391 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1393 if (TREE_CODE (e) == FUNCTION_DECL)
1394 t = size_int (DECL_ALIGN_UNIT (e));
1398 else if (type_unknown_p (e))
1400 cxx_incomplete_type_error (e, TREE_TYPE (e));
1404 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1406 return fold_convert (size_type_node, t);
1409 /* Process a sizeof or alignof expression E with code OP where the operand
1410 is an expression. */
1413 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1415 if (op == SIZEOF_EXPR)
1416 return cxx_sizeof_expr (e);
1418 return cxx_alignof_expr (e);
1421 /* EXPR is being used in a context that is not a function call.
1426 The expression can be used only as the left-hand operand of a
1427 member function call.
1429 [expr.mptr.operator]
1431 If the result of .* or ->* is a function, then that result can be
1432 used only as the operand for the function call operator ().
1434 by issuing an error message if appropriate. Returns true iff EXPR
1435 violates these rules. */
1438 invalid_nonstatic_memfn_p (tree expr)
1440 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1442 error ("invalid use of non-static member function");
1448 /* If EXP is a reference to a bitfield, and the type of EXP does not
1449 match the declared type of the bitfield, return the declared type
1450 of the bitfield. Otherwise, return NULL_TREE. */
1453 is_bitfield_expr_with_lowered_type (tree exp)
1455 switch (TREE_CODE (exp))
1458 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1460 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1463 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1467 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1473 field = TREE_OPERAND (exp, 1);
1474 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1476 if (same_type_ignoring_top_level_qualifiers_p
1477 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1479 return DECL_BIT_FIELD_TYPE (field);
1487 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1488 bitfield with a lowered type, the type of EXP is returned, rather
1492 unlowered_expr_type (tree exp)
1496 type = is_bitfield_expr_with_lowered_type (exp);
1498 type = TREE_TYPE (exp);
1503 /* Perform the conversions in [expr] that apply when an lvalue appears
1504 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1505 function-to-pointer conversions. In addition, manifest constants
1506 are replaced by their values, and bitfield references are converted
1507 to their declared types.
1509 Although the returned value is being used as an rvalue, this
1510 function does not wrap the returned expression in a
1511 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1512 that the return value is no longer an lvalue. */
1515 decay_conversion (tree exp)
1518 enum tree_code code;
1520 type = TREE_TYPE (exp);
1521 if (type == error_mark_node)
1522 return error_mark_node;
1524 if (type_unknown_p (exp))
1526 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1527 return error_mark_node;
1530 exp = decl_constant_value (exp);
1531 if (error_operand_p (exp))
1532 return error_mark_node;
1534 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1535 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1536 code = TREE_CODE (type);
1537 if (code == VOID_TYPE)
1539 error ("void value not ignored as it ought to be");
1540 return error_mark_node;
1542 if (invalid_nonstatic_memfn_p (exp))
1543 return error_mark_node;
1544 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1545 return build_unary_op (ADDR_EXPR, exp, 0);
1546 if (code == ARRAY_TYPE)
1551 if (TREE_CODE (exp) == INDIRECT_REF)
1552 return build_nop (build_pointer_type (TREE_TYPE (type)),
1553 TREE_OPERAND (exp, 0));
1555 if (TREE_CODE (exp) == COMPOUND_EXPR)
1557 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1558 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1559 TREE_OPERAND (exp, 0), op1);
1563 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1565 error ("invalid use of non-lvalue array");
1566 return error_mark_node;
1569 ptrtype = build_pointer_type (TREE_TYPE (type));
1571 if (TREE_CODE (exp) == VAR_DECL)
1573 if (!cxx_mark_addressable (exp))
1574 return error_mark_node;
1575 adr = build_nop (ptrtype, build_address (exp));
1578 /* This way is better for a COMPONENT_REF since it can
1579 simplify the offset for a component. */
1580 adr = build_unary_op (ADDR_EXPR, exp, 1);
1581 return cp_convert (ptrtype, adr);
1584 /* If a bitfield is used in a context where integral promotion
1585 applies, then the caller is expected to have used
1586 default_conversion. That function promotes bitfields correctly
1587 before calling this function. At this point, if we have a
1588 bitfield referenced, we may assume that is not subject to
1589 promotion, and that, therefore, the type of the resulting rvalue
1590 is the declared type of the bitfield. */
1591 exp = convert_bitfield_to_declared_type (exp);
1593 /* We do not call rvalue() here because we do not want to wrap EXP
1594 in a NON_LVALUE_EXPR. */
1598 Non-class rvalues always have cv-unqualified types. */
1599 type = TREE_TYPE (exp);
1600 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1601 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1606 /* Perform prepatory conversions, as part of the "usual arithmetic
1607 conversions". In particular, as per [expr]:
1609 Whenever an lvalue expression appears as an operand of an
1610 operator that expects the rvalue for that operand, the
1611 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1612 standard conversions are applied to convert the expression to an
1615 In addition, we perform integral promotions here, as those are
1616 applied to both operands to a binary operator before determining
1617 what additional conversions should apply. */
1620 default_conversion (tree exp)
1622 /* Perform the integral promotions first so that bitfield
1623 expressions (which may promote to "int", even if the bitfield is
1624 declared "unsigned") are promoted correctly. */
1625 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1626 exp = perform_integral_promotions (exp);
1627 /* Perform the other conversions. */
1628 exp = decay_conversion (exp);
1633 /* EXPR is an expression with an integral or enumeration type.
1634 Perform the integral promotions in [conv.prom], and return the
1638 perform_integral_promotions (tree expr)
1645 If the bitfield has an enumerated type, it is treated as any
1646 other value of that type for promotion purposes. */
1647 type = is_bitfield_expr_with_lowered_type (expr);
1648 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1649 type = TREE_TYPE (expr);
1650 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1651 promoted_type = type_promotes_to (type);
1652 if (type != promoted_type)
1653 expr = cp_convert (promoted_type, expr);
1657 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1661 inline_conversion (tree exp)
1663 if (TREE_CODE (exp) == FUNCTION_DECL)
1664 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1669 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1670 decay_conversion to one. */
1673 string_conv_p (tree totype, tree exp, int warn)
1677 if (TREE_CODE (totype) != POINTER_TYPE)
1680 t = TREE_TYPE (totype);
1681 if (!same_type_p (t, char_type_node)
1682 && !same_type_p (t, wchar_type_node))
1685 if (TREE_CODE (exp) == STRING_CST)
1687 /* Make sure that we don't try to convert between char and wchar_t. */
1688 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1693 /* Is this a string constant which has decayed to 'const char *'? */
1694 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1695 if (!same_type_p (TREE_TYPE (exp), t))
1698 if (TREE_CODE (exp) != ADDR_EXPR
1699 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1703 /* This warning is not very useful, as it complains about printf. */
1705 warning (OPT_Wwrite_strings,
1706 "deprecated conversion from string constant to %qT",
1712 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1713 can, for example, use as an lvalue. This code used to be in
1714 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1715 expressions, where we're dealing with aggregates. But now it's again only
1716 called from unary_complex_lvalue. The case (in particular) that led to
1717 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1721 rationalize_conditional_expr (enum tree_code code, tree t)
1723 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1724 the first operand is always the one to be used if both operands
1725 are equal, so we know what conditional expression this used to be. */
1726 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1728 tree op0 = TREE_OPERAND (t, 0);
1729 tree op1 = TREE_OPERAND (t, 1);
1731 /* The following code is incorrect if either operand side-effects. */
1732 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1733 && !TREE_SIDE_EFFECTS (op1));
1735 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1736 ? LE_EXPR : GE_EXPR),
1737 op0, TREE_CODE (op0),
1738 op1, TREE_CODE (op1),
1739 /*overloaded_p=*/NULL),
1740 build_unary_op (code, op0, 0),
1741 build_unary_op (code, op1, 0));
1745 build_conditional_expr (TREE_OPERAND (t, 0),
1746 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1747 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1750 /* Given the TYPE of an anonymous union field inside T, return the
1751 FIELD_DECL for the field. If not found return NULL_TREE. Because
1752 anonymous unions can nest, we must also search all anonymous unions
1753 that are directly reachable. */
1756 lookup_anon_field (tree t, tree type)
1760 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1762 if (TREE_STATIC (field))
1764 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1767 /* If we find it directly, return the field. */
1768 if (DECL_NAME (field) == NULL_TREE
1769 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1774 /* Otherwise, it could be nested, search harder. */
1775 if (DECL_NAME (field) == NULL_TREE
1776 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1778 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1786 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1787 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1788 non-NULL, it indicates the path to the base used to name MEMBER.
1789 If PRESERVE_REFERENCE is true, the expression returned will have
1790 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1791 returned will have the type referred to by the reference.
1793 This function does not perform access control; that is either done
1794 earlier by the parser when the name of MEMBER is resolved to MEMBER
1795 itself, or later when overload resolution selects one of the
1796 functions indicated by MEMBER. */
1799 build_class_member_access_expr (tree object, tree member,
1800 tree access_path, bool preserve_reference)
1804 tree result = NULL_TREE;
1806 if (error_operand_p (object) || error_operand_p (member))
1807 return error_mark_node;
1809 gcc_assert (DECL_P (member) || BASELINK_P (member));
1813 The type of the first expression shall be "class object" (of a
1815 object_type = TREE_TYPE (object);
1816 if (!currently_open_class (object_type)
1817 && !complete_type_or_else (object_type, object))
1818 return error_mark_node;
1819 if (!CLASS_TYPE_P (object_type))
1821 error ("request for member %qD in %qE, which is of non-class type %qT",
1822 member, object, object_type);
1823 return error_mark_node;
1826 /* The standard does not seem to actually say that MEMBER must be a
1827 member of OBJECT_TYPE. However, that is clearly what is
1829 if (DECL_P (member))
1831 member_scope = DECL_CLASS_CONTEXT (member);
1833 if (TREE_DEPRECATED (member))
1834 warn_deprecated_use (member);
1837 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1838 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1839 presently be the anonymous union. Go outwards until we find a
1840 type related to OBJECT_TYPE. */
1841 while (ANON_AGGR_TYPE_P (member_scope)
1842 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1844 member_scope = TYPE_CONTEXT (member_scope);
1845 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1847 if (TREE_CODE (member) == FIELD_DECL)
1848 error ("invalid use of nonstatic data member %qE", member);
1850 error ("%qD is not a member of %qT", member, object_type);
1851 return error_mark_node;
1854 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1855 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1856 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1858 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1860 object = build_indirect_ref (temp, NULL);
1863 /* In [expr.ref], there is an explicit list of the valid choices for
1864 MEMBER. We check for each of those cases here. */
1865 if (TREE_CODE (member) == VAR_DECL)
1867 /* A static data member. */
1869 /* If OBJECT has side-effects, they are supposed to occur. */
1870 if (TREE_SIDE_EFFECTS (object))
1871 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1873 else if (TREE_CODE (member) == FIELD_DECL)
1875 /* A non-static data member. */
1880 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1881 && integer_zerop (TREE_OPERAND (object, 0)));
1883 /* Convert OBJECT to the type of MEMBER. */
1884 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1885 TYPE_MAIN_VARIANT (member_scope)))
1890 binfo = lookup_base (access_path ? access_path : object_type,
1891 member_scope, ba_unique, &kind);
1892 if (binfo == error_mark_node)
1893 return error_mark_node;
1895 /* It is invalid to try to get to a virtual base of a
1896 NULL object. The most common cause is invalid use of
1898 if (null_object_p && kind == bk_via_virtual)
1900 error ("invalid access to non-static data member %qD of "
1903 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1904 return error_mark_node;
1907 /* Convert to the base. */
1908 object = build_base_path (PLUS_EXPR, object, binfo,
1910 /* If we found the base successfully then we should be able
1911 to convert to it successfully. */
1912 gcc_assert (object != error_mark_node);
1915 /* Complain about other invalid uses of offsetof, even though they will
1916 give the right answer. Note that we complain whether or not they
1917 actually used the offsetof macro, since there's no way to know at this
1918 point. So we just give a warning, instead of a pedwarn. */
1919 /* Do not produce this warning for base class field references, because
1920 we know for a fact that didn't come from offsetof. This does occur
1921 in various testsuite cases where a null object is passed where a
1922 vtable access is required. */
1923 if (null_object_p && warn_invalid_offsetof
1924 && CLASSTYPE_NON_POD_P (object_type)
1925 && !DECL_FIELD_IS_BASE (member)
1926 && !skip_evaluation)
1928 warning (0, "invalid access to non-static data member %qD of NULL object",
1930 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1933 /* If MEMBER is from an anonymous aggregate, we have converted
1934 OBJECT so that it refers to the class containing the
1935 anonymous union. Generate a reference to the anonymous union
1936 itself, and recur to find MEMBER. */
1937 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1938 /* When this code is called from build_field_call, the
1939 object already has the type of the anonymous union.
1940 That is because the COMPONENT_REF was already
1941 constructed, and was then disassembled before calling
1942 build_field_call. After the function-call code is
1943 cleaned up, this waste can be eliminated. */
1944 && (!same_type_ignoring_top_level_qualifiers_p
1945 (TREE_TYPE (object), DECL_CONTEXT (member))))
1947 tree anonymous_union;
1949 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1950 DECL_CONTEXT (member));
1951 object = build_class_member_access_expr (object,
1953 /*access_path=*/NULL_TREE,
1954 preserve_reference);
1957 /* Compute the type of the field, as described in [expr.ref]. */
1958 type_quals = TYPE_UNQUALIFIED;
1959 member_type = TREE_TYPE (member);
1960 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1962 type_quals = (cp_type_quals (member_type)
1963 | cp_type_quals (object_type));
1965 /* A field is const (volatile) if the enclosing object, or the
1966 field itself, is const (volatile). But, a mutable field is
1967 not const, even within a const object. */
1968 if (DECL_MUTABLE_P (member))
1969 type_quals &= ~TYPE_QUAL_CONST;
1970 member_type = cp_build_qualified_type (member_type, type_quals);
1973 result = build3 (COMPONENT_REF, member_type, object, member,
1975 result = fold_if_not_in_template (result);
1977 /* Mark the expression const or volatile, as appropriate. Even
1978 though we've dealt with the type above, we still have to mark the
1979 expression itself. */
1980 if (type_quals & TYPE_QUAL_CONST)
1981 TREE_READONLY (result) = 1;
1982 if (type_quals & TYPE_QUAL_VOLATILE)
1983 TREE_THIS_VOLATILE (result) = 1;
1985 else if (BASELINK_P (member))
1987 /* The member is a (possibly overloaded) member function. */
1991 /* If the MEMBER is exactly one static member function, then we
1992 know the type of the expression. Otherwise, we must wait
1993 until overload resolution has been performed. */
1994 functions = BASELINK_FUNCTIONS (member);
1995 if (TREE_CODE (functions) == FUNCTION_DECL
1996 && DECL_STATIC_FUNCTION_P (functions))
1997 type = TREE_TYPE (functions);
1999 type = unknown_type_node;
2000 /* Note that we do not convert OBJECT to the BASELINK_BINFO
2001 base. That will happen when the function is called. */
2002 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
2004 else if (TREE_CODE (member) == CONST_DECL)
2006 /* The member is an enumerator. */
2008 /* If OBJECT has side-effects, they are supposed to occur. */
2009 if (TREE_SIDE_EFFECTS (object))
2010 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2015 error ("invalid use of %qD", member);
2016 return error_mark_node;
2019 if (!preserve_reference)
2022 If E2 is declared to have type "reference to T", then ... the
2023 type of E1.E2 is T. */
2024 result = convert_from_reference (result);
2029 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
2030 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2033 lookup_destructor (tree object, tree scope, tree dtor_name)
2035 tree object_type = TREE_TYPE (object);
2036 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2039 if (scope && !check_dtor_name (scope, dtor_type))
2041 error ("qualified type %qT does not match destructor name ~%qT",
2043 return error_mark_node;
2045 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2047 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2048 TYPE_MAIN_VARIANT (object_type), dtor_type);
2049 return error_mark_node;
2051 expr = lookup_member (dtor_type, complete_dtor_identifier,
2052 /*protect=*/1, /*want_type=*/false);
2053 expr = (adjust_result_of_qualified_name_lookup
2054 (expr, dtor_type, object_type));
2058 /* An expression of the form "A::template B" has been resolved to
2059 DECL. Issue a diagnostic if B is not a template or template
2063 check_template_keyword (tree decl)
2065 /* The standard says:
2069 If a name prefixed by the keyword template is not a member
2070 template, the program is ill-formed.
2072 DR 228 removed the restriction that the template be a member
2075 DR 96, if accepted would add the further restriction that explicit
2076 template arguments must be provided if the template keyword is
2077 used, but, as of 2005-10-16, that DR is still in "drafting". If
2078 this DR is accepted, then the semantic checks here can be
2079 simplified, as the entity named must in fact be a template
2080 specialization, rather than, as at present, a set of overloaded
2081 functions containing at least one template function. */
2082 if (TREE_CODE (decl) != TEMPLATE_DECL
2083 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2085 if (!is_overloaded_fn (decl))
2086 pedwarn ("%qD is not a template", decl);
2091 if (BASELINK_P (fns))
2092 fns = BASELINK_FUNCTIONS (fns);
2095 tree fn = OVL_CURRENT (fns);
2096 if (TREE_CODE (fn) == TEMPLATE_DECL
2097 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2099 if (TREE_CODE (fn) == FUNCTION_DECL
2100 && DECL_USE_TEMPLATE (fn)
2101 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2103 fns = OVL_NEXT (fns);
2106 pedwarn ("%qD is not a template", decl);
2111 /* This function is called by the parser to process a class member
2112 access expression of the form OBJECT.NAME. NAME is a node used by
2113 the parser to represent a name; it is not yet a DECL. It may,
2114 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2115 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2116 there is no reason to do the lookup twice, so the parser keeps the
2117 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2118 be a template via the use of the "A::template B" syntax. */
2121 finish_class_member_access_expr (tree object, tree name, bool template_p)
2126 tree access_path = NULL_TREE;
2127 tree orig_object = object;
2128 tree orig_name = name;
2130 if (object == error_mark_node || name == error_mark_node)
2131 return error_mark_node;
2133 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2134 if (!objc_is_public (object, name))
2135 return error_mark_node;
2137 object_type = TREE_TYPE (object);
2139 if (processing_template_decl)
2141 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2142 dependent_type_p (object_type)
2143 /* If NAME is just an IDENTIFIER_NODE, then the expression
2145 || TREE_CODE (object) == IDENTIFIER_NODE
2146 /* If NAME is "f<args>", where either 'f' or 'args' is
2147 dependent, then the expression is dependent. */
2148 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2149 && dependent_template_id_p (TREE_OPERAND (name, 0),
2150 TREE_OPERAND (name, 1)))
2151 /* If NAME is "T::X" where "T" is dependent, then the
2152 expression is dependent. */
2153 || (TREE_CODE (name) == SCOPE_REF
2154 && TYPE_P (TREE_OPERAND (name, 0))
2155 && dependent_type_p (TREE_OPERAND (name, 0))))
2156 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2157 object = build_non_dependent_expr (object);
2162 The type of the first expression shall be "class object" (of a
2164 if (!currently_open_class (object_type)
2165 && !complete_type_or_else (object_type, object))
2166 return error_mark_node;
2167 if (!CLASS_TYPE_P (object_type))
2169 error ("request for member %qD in %qE, which is of non-class type %qT",
2170 name, object, object_type);
2171 return error_mark_node;
2174 if (BASELINK_P (name))
2175 /* A member function that has already been looked up. */
2179 bool is_template_id = false;
2180 tree template_args = NULL_TREE;
2183 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2185 is_template_id = true;
2186 template_args = TREE_OPERAND (name, 1);
2187 name = TREE_OPERAND (name, 0);
2189 if (TREE_CODE (name) == OVERLOAD)
2190 name = DECL_NAME (get_first_fn (name));
2191 else if (DECL_P (name))
2192 name = DECL_NAME (name);
2195 if (TREE_CODE (name) == SCOPE_REF)
2197 /* A qualified name. The qualifying class or namespace `S'
2198 has already been looked up; it is either a TYPE or a
2200 scope = TREE_OPERAND (name, 0);
2201 name = TREE_OPERAND (name, 1);
2203 /* If SCOPE is a namespace, then the qualified name does not
2204 name a member of OBJECT_TYPE. */
2205 if (TREE_CODE (scope) == NAMESPACE_DECL)
2207 error ("%<%D::%D%> is not a member of %qT",
2208 scope, name, object_type);
2209 return error_mark_node;
2212 gcc_assert (CLASS_TYPE_P (scope));
2213 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2214 || TREE_CODE (name) == BIT_NOT_EXPR);
2216 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2217 access_path = lookup_base (object_type, scope, ba_check, NULL);
2218 if (access_path == error_mark_node)
2219 return error_mark_node;
2222 error ("%qT is not a base of %qT", scope, object_type);
2223 return error_mark_node;
2229 access_path = object_type;
2232 if (TREE_CODE (name) == BIT_NOT_EXPR)
2233 member = lookup_destructor (object, scope, name);
2236 /* Look up the member. */
2237 member = lookup_member (access_path, name, /*protect=*/1,
2238 /*want_type=*/false);
2239 if (member == NULL_TREE)
2241 error ("%qD has no member named %qE", object_type, name);
2242 return error_mark_node;
2244 if (member == error_mark_node)
2245 return error_mark_node;
2250 tree template = member;
2252 if (BASELINK_P (template))
2253 template = lookup_template_function (template, template_args);
2256 error ("%qD is not a member template function", name);
2257 return error_mark_node;
2262 if (TREE_DEPRECATED (member))
2263 warn_deprecated_use (member);
2266 check_template_keyword (member);
2268 expr = build_class_member_access_expr (object, member, access_path,
2269 /*preserve_reference=*/false);
2270 if (processing_template_decl && expr != error_mark_node)
2272 if (BASELINK_P (member))
2274 if (TREE_CODE (orig_name) == SCOPE_REF)
2275 BASELINK_QUALIFIED_P (member) = 1;
2278 return build_min_non_dep (COMPONENT_REF, expr,
2279 orig_object, orig_name,
2286 /* Return an expression for the MEMBER_NAME field in the internal
2287 representation of PTRMEM, a pointer-to-member function. (Each
2288 pointer-to-member function type gets its own RECORD_TYPE so it is
2289 more convenient to access the fields by name than by FIELD_DECL.)
2290 This routine converts the NAME to a FIELD_DECL and then creates the
2291 node for the complete expression. */
2294 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2300 /* This code is a stripped down version of
2301 build_class_member_access_expr. It does not work to use that
2302 routine directly because it expects the object to be of class
2304 ptrmem_type = TREE_TYPE (ptrmem);
2305 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2306 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2307 /*want_type=*/false);
2308 member_type = cp_build_qualified_type (TREE_TYPE (member),
2309 cp_type_quals (ptrmem_type));
2310 return fold_build3 (COMPONENT_REF, member_type,
2311 ptrmem, member, NULL_TREE);
2314 /* Given an expression PTR for a pointer, return an expression
2315 for the value pointed to.
2316 ERRORSTRING is the name of the operator to appear in error messages.
2318 This function may need to overload OPERATOR_FNNAME.
2319 Must also handle REFERENCE_TYPEs for C++. */
2322 build_x_indirect_ref (tree expr, const char *errorstring)
2324 tree orig_expr = expr;
2327 if (processing_template_decl)
2329 if (type_dependent_expression_p (expr))
2330 return build_min_nt (INDIRECT_REF, expr);
2331 expr = build_non_dependent_expr (expr);
2334 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2335 NULL_TREE, /*overloaded_p=*/NULL);
2337 rval = build_indirect_ref (expr, errorstring);
2339 if (processing_template_decl && rval != error_mark_node)
2340 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2346 build_indirect_ref (tree ptr, const char *errorstring)
2350 if (ptr == error_mark_node)
2351 return error_mark_node;
2353 if (ptr == current_class_ptr)
2354 return current_class_ref;
2356 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2357 ? ptr : decay_conversion (ptr));
2358 type = TREE_TYPE (pointer);
2360 if (POINTER_TYPE_P (type))
2364 If the type of the expression is "pointer to T," the type
2365 of the result is "T."
2367 We must use the canonical variant because certain parts of
2368 the back end, like fold, do pointer comparisons between
2370 tree t = canonical_type_variant (TREE_TYPE (type));
2372 if (TREE_CODE (ptr) == CONVERT_EXPR
2373 || TREE_CODE (ptr) == NOP_EXPR
2374 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2376 /* If a warning is issued, mark it to avoid duplicates from
2377 the backend. This only needs to be done at
2378 warn_strict_aliasing > 2. */
2379 if (warn_strict_aliasing > 2)
2380 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2381 type, TREE_OPERAND (ptr, 0)))
2382 TREE_NO_WARNING (ptr) = 1;
2385 if (VOID_TYPE_P (t))
2387 /* A pointer to incomplete type (other than cv void) can be
2388 dereferenced [expr.unary.op]/1 */
2389 error ("%qT is not a pointer-to-object type", type);
2390 return error_mark_node;
2392 else if (TREE_CODE (pointer) == ADDR_EXPR
2393 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2394 /* The POINTER was something like `&x'. We simplify `*&x' to
2396 return TREE_OPERAND (pointer, 0);
2399 tree ref = build1 (INDIRECT_REF, t, pointer);
2401 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2402 so that we get the proper error message if the result is used
2403 to assign to. Also, &* is supposed to be a no-op. */
2404 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2405 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2406 TREE_SIDE_EFFECTS (ref)
2407 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2411 /* `pointer' won't be an error_mark_node if we were given a
2412 pointer to member, so it's cool to check for this here. */
2413 else if (TYPE_PTR_TO_MEMBER_P (type))
2414 error ("invalid use of %qs on pointer to member", errorstring);
2415 else if (pointer != error_mark_node)
2418 error ("invalid type argument of %qs", errorstring);
2420 error ("invalid type argument");
2422 return error_mark_node;
2425 /* This handles expressions of the form "a[i]", which denotes
2428 This is logically equivalent in C to *(a+i), but we may do it differently.
2429 If A is a variable or a member, we generate a primitive ARRAY_REF.
2430 This avoids forcing the array out of registers, and can work on
2431 arrays that are not lvalues (for example, members of structures returned
2434 If INDEX is of some user-defined type, it must be converted to
2435 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2436 will inherit the type of the array, which will be some pointer type. */
2439 build_array_ref (tree array, tree idx)
2443 error ("subscript missing in array reference");
2444 return error_mark_node;
2447 if (TREE_TYPE (array) == error_mark_node
2448 || TREE_TYPE (idx) == error_mark_node)
2449 return error_mark_node;
2451 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2453 switch (TREE_CODE (array))
2457 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2458 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2459 TREE_OPERAND (array, 0), value);
2463 return build_conditional_expr
2464 (TREE_OPERAND (array, 0),
2465 build_array_ref (TREE_OPERAND (array, 1), idx),
2466 build_array_ref (TREE_OPERAND (array, 2), idx));
2472 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2476 warn_array_subscript_with_type_char (idx);
2478 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2480 error ("array subscript is not an integer");
2481 return error_mark_node;
2484 /* Apply integral promotions *after* noticing character types.
2485 (It is unclear why we do these promotions -- the standard
2486 does not say that we should. In fact, the natural thing would
2487 seem to be to convert IDX to ptrdiff_t; we're performing
2488 pointer arithmetic.) */
2489 idx = perform_integral_promotions (idx);
2491 /* An array that is indexed by a non-constant
2492 cannot be stored in a register; we must be able to do
2493 address arithmetic on its address.
2494 Likewise an array of elements of variable size. */
2495 if (TREE_CODE (idx) != INTEGER_CST
2496 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2497 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2500 if (!cxx_mark_addressable (array))
2501 return error_mark_node;
2504 /* An array that is indexed by a constant value which is not within
2505 the array bounds cannot be stored in a register either; because we
2506 would get a crash in store_bit_field/extract_bit_field when trying
2507 to access a non-existent part of the register. */
2508 if (TREE_CODE (idx) == INTEGER_CST
2509 && TYPE_DOMAIN (TREE_TYPE (array))
2510 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2512 if (!cxx_mark_addressable (array))
2513 return error_mark_node;
2516 if (pedantic && !lvalue_p (array))
2517 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2519 /* Note in C++ it is valid to subscript a `register' array, since
2520 it is valid to take the address of something with that
2521 storage specification. */
2525 while (TREE_CODE (foo) == COMPONENT_REF)
2526 foo = TREE_OPERAND (foo, 0);
2527 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2528 warning (OPT_Wextra, "subscripting array declared %<register%>");
2531 type = TREE_TYPE (TREE_TYPE (array));
2532 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2533 /* Array ref is const/volatile if the array elements are
2534 or if the array is.. */
2535 TREE_READONLY (rval)
2536 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2537 TREE_SIDE_EFFECTS (rval)
2538 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2539 TREE_THIS_VOLATILE (rval)
2540 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2541 return require_complete_type (fold_if_not_in_template (rval));
2545 tree ar = default_conversion (array);
2546 tree ind = default_conversion (idx);
2548 /* Put the integer in IND to simplify error checking. */
2549 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2556 if (ar == error_mark_node)
2559 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2561 error ("subscripted value is neither array nor pointer");
2562 return error_mark_node;
2564 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2566 error ("array subscript is not an integer");
2567 return error_mark_node;
2570 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2575 /* Resolve a pointer to member function. INSTANCE is the object
2576 instance to use, if the member points to a virtual member.
2578 This used to avoid checking for virtual functions if basetype
2579 has no virtual functions, according to an earlier ANSI draft.
2580 With the final ISO C++ rules, such an optimization is
2581 incorrect: A pointer to a derived member can be static_cast
2582 to pointer-to-base-member, as long as the dynamic object
2583 later has the right member. */
2586 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2588 if (TREE_CODE (function) == OFFSET_REF)
2589 function = TREE_OPERAND (function, 1);
2591 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2593 tree idx, delta, e1, e2, e3, vtbl, basetype;
2594 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2596 tree instance_ptr = *instance_ptrptr;
2597 tree instance_save_expr = 0;
2598 if (instance_ptr == error_mark_node)
2600 if (TREE_CODE (function) == PTRMEM_CST)
2602 /* Extracting the function address from a pmf is only
2603 allowed with -Wno-pmf-conversions. It only works for
2605 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2606 e1 = convert (fntype, e1);
2611 error ("object missing in use of %qE", function);
2612 return error_mark_node;
2616 if (TREE_SIDE_EFFECTS (instance_ptr))
2617 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2619 if (TREE_SIDE_EFFECTS (function))
2620 function = save_expr (function);
2622 /* Start by extracting all the information from the PMF itself. */
2623 e3 = pfn_from_ptrmemfunc (function);
2624 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2625 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2626 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2628 case ptrmemfunc_vbit_in_pfn:
2629 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2630 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2633 case ptrmemfunc_vbit_in_delta:
2634 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2635 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2642 /* Convert down to the right base before using the instance. A
2643 special case is that in a pointer to member of class C, C may
2644 be incomplete. In that case, the function will of course be
2645 a member of C, and no conversion is required. In fact,
2646 lookup_base will fail in that case, because incomplete
2647 classes do not have BINFOs. */
2648 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2649 if (!same_type_ignoring_top_level_qualifiers_p
2650 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2652 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2653 basetype, ba_check, NULL);
2654 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2656 if (instance_ptr == error_mark_node)
2657 return error_mark_node;
2659 /* ...and then the delta in the PMF. */
2660 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2661 instance_ptr, delta);
2663 /* Hand back the adjusted 'this' argument to our caller. */
2664 *instance_ptrptr = instance_ptr;
2666 /* Next extract the vtable pointer from the object. */
2667 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2669 vtbl = build_indirect_ref (vtbl, NULL);
2671 /* Finally, extract the function pointer from the vtable. */
2672 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2673 e2 = build_indirect_ref (e2, NULL);
2674 TREE_CONSTANT (e2) = 1;
2675 TREE_INVARIANT (e2) = 1;
2677 /* When using function descriptors, the address of the
2678 vtable entry is treated as a function pointer. */
2679 if (TARGET_VTABLE_USES_DESCRIPTORS)
2680 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2681 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2683 TREE_TYPE (e2) = TREE_TYPE (e3);
2684 e1 = build_conditional_expr (e1, e2, e3);
2686 /* Make sure this doesn't get evaluated first inside one of the
2687 branches of the COND_EXPR. */
2688 if (instance_save_expr)
2689 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2690 instance_save_expr, e1);
2697 /* APPLE LOCAL begin blocks 6040305 (cm) */
2698 /* APPLE LOCAL begin radar 5847213 - radar 6329245 */
2700 build_block_call - Routine to build a block call; as in:
2701 ((double(*)(void *, int))(BLOCK_PTR_EXP->__FuncPtr))(I, 42);
2702 FNTYPE is the original function type derived from the syntax.
2703 BLOCK_PTR_EXP is the block pointer variable.
2704 PARAMS is the parameter list.
2707 build_block_call (tree fntype, tree block_ptr_exp, tree params)
2709 tree function_ptr_exp;
2712 /* APPLE LOCAL radar 6396238 */
2713 bool block_ptr_exp_side_effect = TREE_SIDE_EFFECTS (block_ptr_exp);
2715 /* First convert it to 'void *'. */
2716 block_ptr_exp = convert (ptr_type_node, block_ptr_exp);
2717 gcc_assert (generic_block_literal_struct_type);
2718 block_ptr_exp = convert (build_pointer_type (generic_block_literal_struct_type),
2720 if (block_ptr_exp_side_effect)
2721 block_ptr_exp = save_expr (block_ptr_exp);
2723 /* BLOCK_PTR_VAR->__FuncPtr */
2725 finish_class_member_access_expr (build_indirect_ref (block_ptr_exp, "->"),
2726 get_identifier ("__FuncPtr"), false);
2727 gcc_assert (function_ptr_exp);
2729 /* Build: result_type(*)(void *, function-arg-type-list) */
2730 typelist = TYPE_ARG_TYPES (fntype);
2731 typelist = tree_cons (NULL_TREE, ptr_type_node, typelist);
2732 fntype = build_function_type (TREE_TYPE (fntype), typelist);
2733 function_ptr_exp = convert (build_pointer_type (fntype), function_ptr_exp);
2734 params = tree_cons (NULL_TREE, block_ptr_exp, params);
2735 result = build3 (CALL_EXPR, TREE_TYPE (fntype),
2736 function_ptr_exp, params, NULL_TREE);
2737 /* FIXME: should do more from build_cxx_call */
2738 result = convert_from_reference (result);
2741 /* APPLE LOCAL end radar 5847213 - radar 6329245 */
2742 /* APPLE LOCAL end blocks 6040305 (cm) */
2745 build_function_call (tree function, tree params)
2747 tree fntype, fndecl;
2748 tree coerced_params;
2749 tree name = NULL_TREE;
2751 tree original = function;
2753 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2754 expressions, like those used for ObjC messenger dispatches. */
2755 function = objc_rewrite_function_call (function, params);
2757 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2758 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2759 if (TREE_CODE (function) == NOP_EXPR
2760 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2761 function = TREE_OPERAND (function, 0);
2763 if (TREE_CODE (function) == FUNCTION_DECL)
2765 name = DECL_NAME (function);
2767 mark_used (function);
2770 /* Convert anything with function type to a pointer-to-function. */
2771 if (pedantic && DECL_MAIN_P (function))
2772 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2774 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2775 (because calling an inline function does not mean the function
2776 needs to be separately compiled). */
2778 if (DECL_INLINE (function))
2779 function = inline_conversion (function);
2781 function = build_addr_func (function);
2787 function = build_addr_func (function);
2790 if (function == error_mark_node)
2791 return error_mark_node;
2793 fntype = TREE_TYPE (function);
2795 if (TYPE_PTRMEMFUNC_P (fntype))
2797 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2798 "function in %<%E (...)%>",
2800 return error_mark_node;
2803 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2804 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2806 /* APPLE LOCAL blocks 6040305 */
2807 if (!(((TREE_CODE (fntype) == POINTER_TYPE || TREE_CODE (fntype) == BLOCK_POINTER_TYPE)
2808 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2810 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2812 error ("%qE cannot be used as a function", original);
2813 return error_mark_node;
2816 /* fntype now gets the type of function pointed to. */
2817 fntype = TREE_TYPE (fntype);
2819 /* Convert the parameters to the types declared in the
2820 function prototype, or apply default promotions. */
2822 /* APPLE LOCAL begin radar 6087117 */
2823 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2824 params, fndecl, LOOKUP_NORMAL,
2825 (TREE_CODE (TREE_TYPE (function)) == BLOCK_POINTER_TYPE));
2826 /* APPLE LOCAL end radar 6087117 */
2827 if (coerced_params == error_mark_node)
2828 return error_mark_node;
2830 /* Check for errors in format strings and inappropriately
2833 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2834 TYPE_ARG_TYPES (fntype));
2835 /* APPLE LOCAL begin blocks 6040305 */
2836 if (TREE_CODE (TREE_TYPE (function)) == BLOCK_POINTER_TYPE)
2837 return build_block_call (fntype, function, coerced_params);
2838 /* APPLE LOCAL end blocks 6040305 */
2840 return build_cxx_call (function, coerced_params);
2843 /* Convert the actual parameter expressions in the list VALUES
2844 to the types in the list TYPELIST.
2845 If parmdecls is exhausted, or when an element has NULL as its type,
2846 perform the default conversions.
2848 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2850 This is also where warnings about wrong number of args are generated.
2852 Return a list of expressions for the parameters as converted.
2854 Both VALUES and the returned value are chains of TREE_LIST nodes
2855 with the elements of the list in the TREE_VALUE slots of those nodes.
2857 In C++, unspecified trailing parameters can be filled in with their
2858 default arguments, if such were specified. Do so here. */
2861 /* APPLE LOCAL radar 6087117 */
2862 convert_arguments (tree typelist, tree values, tree fndecl, int flags, int block_call)
2864 tree typetail, valtail;
2865 tree result = NULL_TREE;
2866 const char *called_thing = 0;
2869 /* Argument passing is always copy-initialization. */
2870 flags |= LOOKUP_ONLYCONVERTING;
2874 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2876 if (DECL_NAME (fndecl) == NULL_TREE
2877 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2878 called_thing = "constructor";
2880 called_thing = "member function";
2883 called_thing = "function";
2886 for (valtail = values, typetail = typelist;
2888 valtail = TREE_CHAIN (valtail), i++)
2890 tree type = typetail ? TREE_VALUE (typetail) : 0;
2891 tree val = TREE_VALUE (valtail);
2893 if (val == error_mark_node || type == error_mark_node)
2894 return error_mark_node;
2896 if (type == void_type_node)
2900 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2901 error ("at this point in file");
2904 /* APPLE LOCAL radar 6087117 */
2905 error ("too many arguments to %s", (block_call ? "block call" : "function"));
2906 /* In case anybody wants to know if this argument
2909 TREE_TYPE (tree_last (result)) = error_mark_node;
2913 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2914 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2915 if (TREE_CODE (val) == NOP_EXPR
2916 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2917 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2918 val = TREE_OPERAND (val, 0);
2920 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2922 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2923 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2924 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2925 val = decay_conversion (val);
2928 if (val == error_mark_node)
2929 return error_mark_node;
2933 /* Formal parm type is specified by a function prototype. */
2936 if (!COMPLETE_TYPE_P (complete_type (type)))
2939 error ("parameter %P of %qD has incomplete type %qT",
2942 error ("parameter %P has incomplete type %qT", i, type);
2943 parmval = error_mark_node;
2947 parmval = convert_for_initialization
2948 (NULL_TREE, type, val, flags,
2949 "argument passing", fndecl, i);
2950 parmval = convert_for_arg_passing (type, parmval);
2953 if (parmval == error_mark_node)
2954 return error_mark_node;
2956 result = tree_cons (NULL_TREE, parmval, result);
2960 if (fndecl && DECL_BUILT_IN (fndecl)
2961 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2962 /* Don't do ellipsis conversion for __built_in_constant_p
2963 as this will result in spurious warnings for non-POD
2965 val = require_complete_type (val);
2967 val = convert_arg_to_ellipsis (val);
2969 result = tree_cons (NULL_TREE, val, result);
2973 typetail = TREE_CHAIN (typetail);
2976 if (typetail != 0 && typetail != void_list_node)
2978 /* See if there are default arguments that can be used. */
2979 if (TREE_PURPOSE (typetail)
2980 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2982 for (; typetail != void_list_node; ++i)
2985 = convert_default_arg (TREE_VALUE (typetail),
2986 TREE_PURPOSE (typetail),
2989 if (parmval == error_mark_node)
2990 return error_mark_node;
2992 result = tree_cons (0, parmval, result);
2993 typetail = TREE_CHAIN (typetail);
2994 /* ends with `...'. */
2995 if (typetail == NULL_TREE)
3003 error ("too few arguments to %s %q+#D", called_thing, fndecl);
3004 error ("at this point in file");
3007 /* APPLE LOCAL radar 6087117 */
3008 error ("too few arguments to %s", (block_call ? "block call" : "function"));
3009 return error_mark_node;
3013 return nreverse (result);
3016 /* Build a binary-operation expression, after performing default
3017 conversions on the operands. CODE is the kind of expression to build. */
3020 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
3021 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
3030 if (processing_template_decl)
3032 if (type_dependent_expression_p (arg1)
3033 || type_dependent_expression_p (arg2))
3034 return build_min_nt (code, arg1, arg2);
3035 arg1 = build_non_dependent_expr (arg1);
3036 arg2 = build_non_dependent_expr (arg2);
3039 if (code == DOTSTAR_EXPR)
3040 expr = build_m_component_ref (arg1, arg2);
3042 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3045 /* Check for cases such as x+y<<z which users are likely to
3046 misinterpret. But don't warn about obj << x + y, since that is a
3047 common idiom for I/O. */
3048 if (warn_parentheses
3049 && !processing_template_decl
3050 && !error_operand_p (arg1)
3051 && !error_operand_p (arg2)
3052 && (code != LSHIFT_EXPR
3053 || !IS_AGGR_TYPE (TREE_TYPE (arg1))))
3054 warn_about_parentheses (code, arg1_code, arg2_code);
3056 if (processing_template_decl && expr != error_mark_node)
3057 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
3062 /* Build a binary-operation expression without default conversions.
3063 CODE is the kind of expression to build.
3064 This function differs from `build' in several ways:
3065 the data type of the result is computed and recorded in it,
3066 warnings are generated if arg data types are invalid,
3067 special handling for addition and subtraction of pointers is known,
3068 and some optimization is done (operations on narrow ints
3069 are done in the narrower type when that gives the same result).
3070 Constant folding is also done before the result is returned.
3072 Note that the operands will never have enumeral types
3073 because either they have just had the default conversions performed
3074 or they have both just been converted to some other type in which
3075 the arithmetic is to be done.
3077 C++: must do special pointer arithmetic when implementing
3078 multiple inheritance, and deal with pointer to member functions. */
3081 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3082 int convert_p ATTRIBUTE_UNUSED)
3085 enum tree_code code0, code1;
3087 const char *invalid_op_diag;
3089 /* Expression code to give to the expression when it is built.
3090 Normally this is CODE, which is what the caller asked for,
3091 but in some special cases we change it. */
3092 enum tree_code resultcode = code;
3094 /* Data type in which the computation is to be performed.
3095 In the simplest cases this is the common type of the arguments. */
3096 tree result_type = NULL;
3098 /* Nonzero means operands have already been type-converted
3099 in whatever way is necessary.
3100 Zero means they need to be converted to RESULT_TYPE. */
3103 /* Nonzero means create the expression with this type, rather than
3105 tree build_type = 0;
3107 /* Nonzero means after finally constructing the expression
3108 convert it to this type. */
3109 tree final_type = 0;
3113 /* Nonzero if this is an operation like MIN or MAX which can
3114 safely be computed in short if both args are promoted shorts.
3115 Also implies COMMON.
3116 -1 indicates a bitwise operation; this makes a difference
3117 in the exact conditions for when it is safe to do the operation
3118 in a narrower mode. */
3121 /* Nonzero if this is a comparison operation;
3122 if both args are promoted shorts, compare the original shorts.
3123 Also implies COMMON. */
3124 int short_compare = 0;
3126 /* Nonzero if this is a right-shift operation, which can be computed on the
3127 original short and then promoted if the operand is a promoted short. */
3128 int short_shift = 0;
3130 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3133 /* True if both operands have arithmetic type. */
3134 bool arithmetic_types_p;
3136 /* Apply default conversions. */
3140 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3141 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3142 || code == TRUTH_XOR_EXPR)
3144 if (!really_overloaded_fn (op0))
3145 op0 = decay_conversion (op0);
3146 if (!really_overloaded_fn (op1))
3147 op1 = decay_conversion (op1);
3151 if (!really_overloaded_fn (op0))
3152 op0 = default_conversion (op0);
3153 if (!really_overloaded_fn (op1))
3154 op1 = default_conversion (op1);
3157 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3158 STRIP_TYPE_NOPS (op0);
3159 STRIP_TYPE_NOPS (op1);
3161 /* DTRT if one side is an overloaded function, but complain about it. */
3162 if (type_unknown_p (op0))
3164 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3165 if (t != error_mark_node)
3167 pedwarn ("assuming cast to type %qT from overloaded function",
3172 if (type_unknown_p (op1))
3174 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3175 if (t != error_mark_node)
3177 pedwarn ("assuming cast to type %qT from overloaded function",
3183 type0 = TREE_TYPE (op0);
3184 type1 = TREE_TYPE (op1);
3186 /* The expression codes of the data types of the arguments tell us
3187 whether the arguments are integers, floating, pointers, etc. */
3188 code0 = TREE_CODE (type0);
3189 code1 = TREE_CODE (type1);
3191 /* If an error was already reported for one of the arguments,
3192 avoid reporting another error. */
3194 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3195 return error_mark_node;
3197 if ((invalid_op_diag
3198 = targetm.invalid_binary_op (code, type0, type1)))
3200 error (invalid_op_diag, "");
3201 return error_mark_node;
3207 /* Subtraction of two similar pointers.
3208 We must subtract them as integers, then divide by object size. */
3209 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3210 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3212 return pointer_diff (op0, op1, common_type (type0, type1));
3213 /* In all other cases except pointer - int, the usual arithmetic
3215 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3220 /* The pointer - int case is just like pointer + int; fall
3223 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3224 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3228 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3229 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3230 if (processing_template_decl)
3232 result_type = TREE_TYPE (ptr_operand);
3235 return cp_pointer_int_sum (code,
3246 case TRUNC_DIV_EXPR:
3248 case FLOOR_DIV_EXPR:
3249 case ROUND_DIV_EXPR:
3250 case EXACT_DIV_EXPR:
3251 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3252 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3253 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3254 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3256 enum tree_code tcode0 = code0, tcode1 = code1;
3258 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3259 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3260 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3261 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3263 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3264 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3265 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3266 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3268 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3269 resultcode = RDIV_EXPR;
3271 /* When dividing two signed integers, we have to promote to int.
3272 unless we divide by a constant != -1. Note that default
3273 conversion will have been performed on the operands at this
3274 point, so we have to dig out the original type to find out if
3276 shorten = ((TREE_CODE (op0) == NOP_EXPR
3277 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3278 || (TREE_CODE (op1) == INTEGER_CST
3279 && ! integer_all_onesp (op1)));
3288 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3289 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3293 case TRUNC_MOD_EXPR:
3294 case FLOOR_MOD_EXPR:
3295 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3296 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3297 else if (code1 == REAL_TYPE && real_zerop (op1))
3298 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3300 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3302 /* Although it would be tempting to shorten always here, that loses
3303 on some targets, since the modulo instruction is undefined if the
3304 quotient can't be represented in the computation mode. We shorten
3305 only if unsigned or if dividing by something we know != -1. */
3306 shorten = ((TREE_CODE (op0) == NOP_EXPR
3307 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3308 || (TREE_CODE (op1) == INTEGER_CST
3309 && ! integer_all_onesp (op1)));
3314 case TRUTH_ANDIF_EXPR:
3315 case TRUTH_ORIF_EXPR:
3316 case TRUTH_AND_EXPR:
3318 result_type = boolean_type_node;
3321 /* Shift operations: result has same type as first operand;
3322 always convert second operand to int.
3323 Also set SHORT_SHIFT if shifting rightward. */
3326 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3328 result_type = type0;
3329 if (TREE_CODE (op1) == INTEGER_CST)
3331 if (tree_int_cst_lt (op1, integer_zero_node))
3332 warning (0, "right shift count is negative");
3335 if (! integer_zerop (op1))
3337 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3338 warning (0, "right shift count >= width of type");
3341 /* Convert the shift-count to an integer, regardless of
3342 size of value being shifted. */
3343 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3344 op1 = cp_convert (integer_type_node, op1);
3345 /* Avoid converting op1 to result_type later. */
3351 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3353 result_type = type0;
3354 if (TREE_CODE (op1) == INTEGER_CST)
3356 if (tree_int_cst_lt (op1, integer_zero_node))
3357 warning (0, "left shift count is negative");
3358 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3359 warning (0, "left shift count >= width of type");
3361 /* Convert the shift-count to an integer, regardless of
3362 size of value being shifted. */
3363 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3364 op1 = cp_convert (integer_type_node, op1);
3365 /* Avoid converting op1 to result_type later. */
3372 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3374 result_type = type0;
3375 if (TREE_CODE (op1) == INTEGER_CST)
3377 if (tree_int_cst_lt (op1, integer_zero_node))
3378 warning (0, "%s rotate count is negative",
3379 (code == LROTATE_EXPR) ? "left" : "right");
3380 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3381 warning (0, "%s rotate count >= width of type",
3382 (code == LROTATE_EXPR) ? "left" : "right");
3384 /* Convert the shift-count to an integer, regardless of
3385 size of value being shifted. */
3386 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3387 op1 = cp_convert (integer_type_node, op1);
3393 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3394 warning (OPT_Wfloat_equal,
3395 "comparing floating point with == or != is unsafe");
3396 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3397 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3398 warning (OPT_Waddress,
3399 "comparison with string literal results in unspecified behaviour");
3401 build_type = boolean_type_node;
3402 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3403 || code0 == COMPLEX_TYPE)
3404 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3405 || code1 == COMPLEX_TYPE))
3407 /* APPLE LOCAL begin blocks 6040305 */
3408 else if (((code0 == POINTER_TYPE || code0 == BLOCK_POINTER_TYPE)
3409 && (code1 == POINTER_TYPE || code1 == BLOCK_POINTER_TYPE))
3410 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3411 /* APPLE LOCAL end blocks 6040305 */
3412 result_type = composite_pointer_type (type0, type1, op0, op1,
3414 /* APPLE LOCAL blocks 6040305 (cl) */
3415 else if ((code0 == POINTER_TYPE || code0 == BLOCK_POINTER_TYPE || TYPE_PTRMEM_P (type0))
3416 && null_ptr_cst_p (op1))
3417 result_type = type0;
3418 /* APPLE LOCAL blocks 6040305 (cl) */
3419 else if ((code1 == POINTER_TYPE || code1 == BLOCK_POINTER_TYPE || TYPE_PTRMEM_P (type1))
3420 && null_ptr_cst_p (op0))
3421 result_type = type1;
3422 /* APPLE LOCAL blocks 6040305 (cl) */
3423 else if ((code0 == POINTER_TYPE || code0 == BLOCK_POINTER_TYPE) && code1 == INTEGER_TYPE)
3425 result_type = type0;
3426 error ("ISO C++ forbids comparison between pointer and integer");
3428 /* APPLE LOCAL blocks 6040305 (cl) */
3429 else if (code0 == INTEGER_TYPE && (code1 == POINTER_TYPE || code1 == BLOCK_POINTER_TYPE))
3431 result_type = type1;
3432 error ("ISO C++ forbids comparison between pointer and integer");
3434 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3436 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3437 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3438 result_type = TREE_TYPE (op0);
3440 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3441 return cp_build_binary_op (code, op1, op0);
3442 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3443 && same_type_p (type0, type1))
3445 /* E will be the final comparison. */
3447 /* E1 and E2 are for scratch. */
3455 if (TREE_SIDE_EFFECTS (op0))
3456 op0 = save_expr (op0);
3457 if (TREE_SIDE_EFFECTS (op1))
3458 op1 = save_expr (op1);
3463 && (!op0.pfn || op0.delta == op1.delta))
3465 The reason for the `!op0.pfn' bit is that a NULL
3466 pointer-to-member is any member with a zero PFN; the
3467 DELTA field is unspecified. */
3468 pfn0 = pfn_from_ptrmemfunc (op0);
3469 pfn1 = pfn_from_ptrmemfunc (op1);
3470 delta0 = build_ptrmemfunc_access_expr (op0,
3472 delta1 = build_ptrmemfunc_access_expr (op1,
3474 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3475 e2 = cp_build_binary_op (EQ_EXPR,
3477 cp_convert (TREE_TYPE (pfn0),
3478 integer_zero_node));
3479 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3480 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3481 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3482 if (code == EQ_EXPR)
3484 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3488 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3489 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3491 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3492 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3500 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3501 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3503 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3504 result_type = composite_pointer_type (type0, type1, op0, op1,
3512 if (TREE_CODE (orig_op0) == STRING_CST
3513 || TREE_CODE (orig_op1) == STRING_CST)
3514 warning (OPT_Waddress,
3515 "comparison with string literal results in unspecified behaviour");
3517 build_type = boolean_type_node;
3518 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3519 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3521 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3522 result_type = composite_pointer_type (type0, type1, op0, op1,
3524 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3525 && integer_zerop (op1))
3526 result_type = type0;
3527 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3528 && integer_zerop (op0))
3529 result_type = type1;
3530 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3532 result_type = type0;
3533 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3535 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3537 result_type = type1;
3538 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3542 case UNORDERED_EXPR:
3549 build_type = integer_type_node;
3550 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3552 error ("unordered comparison on non-floating point argument");
3553 return error_mark_node;
3562 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3563 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3564 || code1 == COMPLEX_TYPE)))
3565 arithmetic_types_p = 1;
3568 arithmetic_types_p = 0;
3569 /* Vector arithmetic is only allowed when both sides are vectors. */
3570 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3572 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3573 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3576 binary_op_error (code, type0, type1);
3577 return error_mark_node;
3579 arithmetic_types_p = 1;
3582 /* Determine the RESULT_TYPE, if it is not already known. */
3584 && arithmetic_types_p
3585 && (shorten || common || short_compare))
3586 result_type = common_type (type0, type1);
3590 error ("invalid operands of types %qT and %qT to binary %qO",
3591 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3592 return error_mark_node;
3595 /* If we're in a template, the only thing we need to know is the
3597 if (processing_template_decl)
3598 return build2 (resultcode,
3599 build_type ? build_type : result_type,
3602 if (arithmetic_types_p)
3604 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3606 /* For certain operations (which identify themselves by shorten != 0)
3607 if both args were extended from the same smaller type,
3608 do the arithmetic in that type and then extend.
3610 shorten !=0 and !=1 indicates a bitwise operation.
3611 For them, this optimization is safe only if
3612 both args are zero-extended or both are sign-extended.
3613 Otherwise, we might change the result.
3614 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3615 but calculated in (unsigned short) it would be (unsigned short)-1. */
3617 if (shorten && none_complex)
3619 int unsigned0, unsigned1;
3620 tree arg0 = get_narrower (op0, &unsigned0);
3621 tree arg1 = get_narrower (op1, &unsigned1);
3622 /* UNS is 1 if the operation to be done is an unsigned one. */
3623 int uns = TYPE_UNSIGNED (result_type);
3626 final_type = result_type;
3628 /* Handle the case that OP0 does not *contain* a conversion
3629 but it *requires* conversion to FINAL_TYPE. */
3631 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3632 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3633 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3634 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3636 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3638 /* For bitwise operations, signedness of nominal type
3639 does not matter. Consider only how operands were extended. */
3643 /* Note that in all three cases below we refrain from optimizing
3644 an unsigned operation on sign-extended args.
3645 That would not be valid. */
3647 /* Both args variable: if both extended in same way
3648 from same width, do it in that width.
3649 Do it unsigned if args were zero-extended. */
3650 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3651 < TYPE_PRECISION (result_type))
3652 && (TYPE_PRECISION (TREE_TYPE (arg1))
3653 == TYPE_PRECISION (TREE_TYPE (arg0)))
3654 && unsigned0 == unsigned1
3655 && (unsigned0 || !uns))
3656 result_type = c_common_signed_or_unsigned_type
3657 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3658 else if (TREE_CODE (arg0) == INTEGER_CST
3659 && (unsigned1 || !uns)
3660 && (TYPE_PRECISION (TREE_TYPE (arg1))
3661 < TYPE_PRECISION (result_type))
3662 && (type = c_common_signed_or_unsigned_type
3663 (unsigned1, TREE_TYPE (arg1)),
3664 int_fits_type_p (arg0, type)))
3666 else if (TREE_CODE (arg1) == INTEGER_CST
3667 && (unsigned0 || !uns)
3668 && (TYPE_PRECISION (TREE_TYPE (arg0))
3669 < TYPE_PRECISION (result_type))
3670 && (type = c_common_signed_or_unsigned_type
3671 (unsigned0, TREE_TYPE (arg0)),
3672 int_fits_type_p (arg1, type)))
3676 /* Shifts can be shortened if shifting right. */
3681 tree arg0 = get_narrower (op0, &unsigned_arg);
3683 final_type = result_type;
3685 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3686 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3688 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3689 /* We can shorten only if the shift count is less than the
3690 number of bits in the smaller type size. */
3691 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3692 /* If arg is sign-extended and then unsigned-shifted,
3693 we can simulate this with a signed shift in arg's type
3694 only if the extended result is at least twice as wide
3695 as the arg. Otherwise, the shift could use up all the
3696 ones made by sign-extension and bring in zeros.
3697 We can't optimize that case at all, but in most machines
3698 it never happens because available widths are 2**N. */
3699 && (!TYPE_UNSIGNED (final_type)
3701 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3702 <= TYPE_PRECISION (result_type))))
3704 /* Do an unsigned shift if the operand was zero-extended. */
3706 = c_common_signed_or_unsigned_type (unsigned_arg,
3708 /* Convert value-to-be-shifted to that type. */
3709 if (TREE_TYPE (op0) != result_type)
3710 op0 = cp_convert (result_type, op0);
3715 /* Comparison operations are shortened too but differently.
3716 They identify themselves by setting short_compare = 1. */
3720 /* Don't write &op0, etc., because that would prevent op0
3721 from being kept in a register.
3722 Instead, make copies of the our local variables and
3723 pass the copies by reference, then copy them back afterward. */
3724 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3725 enum tree_code xresultcode = resultcode;
3727 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3729 return cp_convert (boolean_type_node, val);
3730 op0 = xop0, op1 = xop1;
3732 resultcode = xresultcode;
3735 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3736 && warn_sign_compare
3737 /* Do not warn until the template is instantiated; we cannot
3738 bound the ranges of the arguments until that point. */
3739 && !processing_template_decl)
3741 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3742 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3744 int unsignedp0, unsignedp1;
3745 tree primop0 = get_narrower (op0, &unsignedp0);
3746 tree primop1 = get_narrower (op1, &unsignedp1);
3748 /* Check for comparison of different enum types. */
3749 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3750 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3751 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3752 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3754 warning (0, "comparison between types %q#T and %q#T",
3755 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3758 /* Give warnings for comparisons between signed and unsigned
3759 quantities that may fail. */
3760 /* Do the checking based on the original operand trees, so that
3761 casts will be considered, but default promotions won't be. */
3763 /* Do not warn if the comparison is being done in a signed type,
3764 since the signed type will only be chosen if it can represent
3765 all the values of the unsigned type. */
3766 if (!TYPE_UNSIGNED (result_type))
3768 /* Do not warn if both operands are unsigned. */
3769 else if (op0_signed == op1_signed)
3771 /* Do not warn if the signed quantity is an unsuffixed
3772 integer literal (or some static constant expression
3773 involving such literals or a conditional expression
3774 involving such literals) and it is non-negative. */
3775 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3776 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3778 /* Do not warn if the comparison is an equality operation,
3779 the unsigned quantity is an integral constant and it does
3780 not use the most significant bit of result_type. */
3781 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3782 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3783 && int_fits_type_p (orig_op1, c_common_signed_type
3785 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3786 && int_fits_type_p (orig_op0, c_common_signed_type
3790 warning (0, "comparison between signed and unsigned integer expressions");
3792 /* Warn if two unsigned values are being compared in a size
3793 larger than their original size, and one (and only one) is the
3794 result of a `~' operator. This comparison will always fail.
3796 Also warn if one operand is a constant, and the constant does not
3797 have all bits set that are set in the ~ operand when it is
3800 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3801 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3803 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3804 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3805 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3806 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3808 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3811 HOST_WIDE_INT constant, mask;
3815 if (host_integerp (primop0, 0))
3818 unsignedp = unsignedp1;
3819 constant = tree_low_cst (primop0, 0);
3824 unsignedp = unsignedp0;
3825 constant = tree_low_cst (primop1, 0);
3828 bits = TYPE_PRECISION (TREE_TYPE (primop));
3829 if (bits < TYPE_PRECISION (result_type)
3830 && bits < HOST_BITS_PER_LONG && unsignedp)
3832 mask = (~ (HOST_WIDE_INT) 0) << bits;
3833 if ((mask & constant) != mask)
3834 warning (0, "comparison of promoted ~unsigned with constant");
3837 else if (unsignedp0 && unsignedp1
3838 && (TYPE_PRECISION (TREE_TYPE (primop0))
3839 < TYPE_PRECISION (result_type))
3840 && (TYPE_PRECISION (TREE_TYPE (primop1))
3841 < TYPE_PRECISION (result_type)))
3842 warning (0, "comparison of promoted ~unsigned with unsigned");
3847 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3848 Then the expression will be built.
3849 It will be given type FINAL_TYPE if that is nonzero;
3850 otherwise, it will be given type RESULT_TYPE. */
3852 /* Issue warnings about peculiar, but valid, uses of NULL. */
3853 if (/* It's reasonable to use pointer values as operands of &&
3854 and ||, so NULL is no exception. */
3855 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3856 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3857 (orig_op0 == null_node
3858 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3859 /* Or vice versa. */
3860 || (orig_op1 == null_node
3861 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3862 /* Or, both are NULL and the operation was not a comparison. */
3863 || (orig_op0 == null_node && orig_op1 == null_node
3864 && code != EQ_EXPR && code != NE_EXPR)))
3865 /* Some sort of arithmetic operation involving NULL was
3866 performed. Note that pointer-difference and pointer-addition
3867 have already been handled above, and so we don't end up here in
3869 warning (0, "NULL used in arithmetic");
3873 if (TREE_TYPE (op0) != result_type)
3874 op0 = cp_convert (result_type, op0);
3875 if (TREE_TYPE (op1) != result_type)
3876 op1 = cp_convert (result_type, op1);
3878 if (op0 == error_mark_node || op1 == error_mark_node)
3879 return error_mark_node;
3882 if (build_type == NULL_TREE)
3883 build_type = result_type;
3885 result = build2 (resultcode, build_type, op0, op1);
3886 result = fold_if_not_in_template (result);
3887 if (final_type != 0)
3888 result = cp_convert (final_type, result);
3890 if (TREE_OVERFLOW_P (result)
3891 && !TREE_OVERFLOW_P (op0)
3892 && !TREE_OVERFLOW_P (op1))
3893 overflow_warning (result);
3898 /* Return a tree for the sum or difference (RESULTCODE says which)
3899 of pointer PTROP and integer INTOP. */
3902 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3904 tree res_type = TREE_TYPE (ptrop);
3906 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3907 in certain circumstance (when it's valid to do so). So we need
3908 to make sure it's complete. We don't need to check here, if we
3909 can actually complete it at all, as those checks will be done in
3910 pointer_int_sum() anyway. */
3911 complete_type (TREE_TYPE (res_type));
3913 return pointer_int_sum (resultcode, ptrop,
3914 fold_if_not_in_template (intop));
3917 /* Return a tree for the difference of pointers OP0 and OP1.
3918 The resulting tree has type int. */
3921 pointer_diff (tree op0, tree op1, tree ptrtype)
3924 tree restype = ptrdiff_type_node;
3925 tree target_type = TREE_TYPE (ptrtype);
3927 if (!complete_type_or_else (target_type, NULL_TREE))
3928 return error_mark_node;
3930 if (pedantic || warn_pointer_arith)
3932 if (TREE_CODE (target_type) == VOID_TYPE)
3933 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3934 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3935 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3936 if (TREE_CODE (target_type) == METHOD_TYPE)
3937 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3940 /* First do the subtraction as integers;
3941 then drop through to build the divide operator. */
3943 op0 = cp_build_binary_op (MINUS_EXPR,
3944 cp_convert (restype, op0),
3945 cp_convert (restype, op1));
3947 /* This generates an error if op1 is a pointer to an incomplete type. */
3948 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3949 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3951 op1 = (TYPE_PTROB_P (ptrtype)
3952 ? size_in_bytes (target_type)
3953 : integer_one_node);
3955 /* Do the division. */
3957 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3958 return fold_if_not_in_template (result);
3961 /* Construct and perhaps optimize a tree representation
3962 for a unary operation. CODE, a tree_code, specifies the operation
3963 and XARG is the operand. */
3966 build_x_unary_op (enum tree_code code, tree xarg)
3968 tree orig_expr = xarg;
3972 if (processing_template_decl)
3974 if (type_dependent_expression_p (xarg))
3975 return build_min_nt (code, xarg, NULL_TREE);
3977 xarg = build_non_dependent_expr (xarg);
3982 /* [expr.unary.op] says:
3984 The address of an object of incomplete type can be taken.
3986 (And is just the ordinary address operator, not an overloaded
3987 "operator &".) However, if the type is a template
3988 specialization, we must complete the type at this point so that
3989 an overloaded "operator &" will be available if required. */
3990 if (code == ADDR_EXPR
3991 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3992 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3993 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3994 || (TREE_CODE (xarg) == OFFSET_REF)))
3995 /* Don't look for a function. */;
3997 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3998 /*overloaded_p=*/NULL);
3999 if (!exp && code == ADDR_EXPR)
4001 /* A pointer to member-function can be formed only by saying
4003 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
4004 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
4006 if (TREE_CODE (xarg) != OFFSET_REF
4007 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4009 error ("invalid use of %qE to form a pointer-to-member-function",
4011 if (TREE_CODE (xarg) != OFFSET_REF)
4012 inform (" a qualified-id is required");
4013 return error_mark_node;
4017 error ("parentheses around %qE cannot be used to form a"
4018 " pointer-to-member-function",
4020 PTRMEM_OK_P (xarg) = 1;
4024 if (TREE_CODE (xarg) == OFFSET_REF)
4026 ptrmem = PTRMEM_OK_P (xarg);
4028 if (!ptrmem && !flag_ms_extensions
4029 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4031 /* A single non-static member, make sure we don't allow a
4032 pointer-to-member. */
4033 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4034 TREE_OPERAND (xarg, 0),
4035 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4036 PTRMEM_OK_P (xarg) = ptrmem;
4039 else if (TREE_CODE (xarg) == TARGET_EXPR)
4040 warning (0, "taking address of temporary");
4041 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4044 if (processing_template_decl && exp != error_mark_node)
4045 exp = build_min_non_dep (code, exp, orig_expr,
4046 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4047 if (TREE_CODE (exp) == ADDR_EXPR)
4048 PTRMEM_OK_P (exp) = ptrmem;
4052 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4053 constants, where a null value is represented by an INTEGER_CST of
4057 cp_truthvalue_conversion (tree expr)
4059 tree type = TREE_TYPE (expr);
4060 if (TYPE_PTRMEM_P (type))
4061 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4063 return c_common_truthvalue_conversion (expr);
4066 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4069 condition_conversion (tree expr)
4072 if (processing_template_decl)
4074 t = perform_implicit_conversion (boolean_type_node, expr);
4075 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4079 /* Return an ADDR_EXPR giving the address of T. This function
4080 attempts no optimizations or simplifications; it is a low-level
4084 build_address (tree t)
4088 if (error_operand_p (t) || !cxx_mark_addressable (t))
4089 return error_mark_node;
4091 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4096 /* Return a NOP_EXPR converting EXPR to TYPE. */
4099 build_nop (tree type, tree expr)
4101 if (type == error_mark_node || error_operand_p (expr))
4103 return build1 (NOP_EXPR, type, expr);
4106 /* C++: Must handle pointers to members.
4108 Perhaps type instantiation should be extended to handle conversion
4109 from aggregates to types we don't yet know we want? (Or are those
4110 cases typically errors which should be reported?)
4112 NOCONVERT nonzero suppresses the default promotions
4113 (such as from short to int). */
4116 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4118 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4121 const char *errstring = NULL;
4123 const char *invalid_op_diag;
4125 if (arg == error_mark_node)
4126 return error_mark_node;
4128 if ((invalid_op_diag
4129 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4134 error (invalid_op_diag, "");
4135 return error_mark_node;
4140 case UNARY_PLUS_EXPR:
4143 int flags = WANT_ARITH | WANT_ENUM;
4144 /* Unary plus (but not unary minus) is allowed on pointers. */
4145 if (code == UNARY_PLUS_EXPR)
4146 flags |= WANT_POINTER;
4147 arg = build_expr_type_conversion (flags, arg, true);
4149 errstring = (code == NEGATE_EXPR
4150 ? "wrong type argument to unary minus"
4151 : "wrong type argument to unary plus");
4154 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4155 arg = perform_integral_promotions (arg);
4157 /* Make sure the result is not an lvalue: a unary plus or minus
4158 expression is always a rvalue. */
4165 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4169 arg = default_conversion (arg);
4171 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4174 errstring = "wrong type argument to bit-complement";
4175 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4176 arg = perform_integral_promotions (arg);
4180 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4181 errstring = "wrong type argument to abs";
4182 else if (!noconvert)
4183 arg = default_conversion (arg);
4187 /* Conjugating a real value is a no-op, but allow it anyway. */
4188 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4189 errstring = "wrong type argument to conjugation";
4190 else if (!noconvert)
4191 arg = default_conversion (arg);
4194 case TRUTH_NOT_EXPR:
4195 arg = perform_implicit_conversion (boolean_type_node, arg);
4196 val = invert_truthvalue (arg);
4197 if (arg != error_mark_node)
4199 errstring = "in argument to unary !";
4206 if (TREE_CODE (arg) == COMPLEX_CST)
4207 return TREE_REALPART (arg);
4208 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4210 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4211 return fold_if_not_in_template (arg);
4217 if (TREE_CODE (arg) == COMPLEX_CST)
4218 return TREE_IMAGPART (arg);
4219 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4221 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4222 return fold_if_not_in_template (arg);
4225 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4227 case PREINCREMENT_EXPR:
4228 case POSTINCREMENT_EXPR:
4229 case PREDECREMENT_EXPR:
4230 case POSTDECREMENT_EXPR:
4231 /* Handle complex lvalues (when permitted)
4232 by reduction to simpler cases. */
4234 val = unary_complex_lvalue (code, arg);
4238 /* Increment or decrement the real part of the value,
4239 and don't change the imaginary part. */
4240 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4244 arg = stabilize_reference (arg);
4245 real = build_unary_op (REALPART_EXPR, arg, 1);
4246 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4247 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4248 build_unary_op (code, real, 1), imag);
4251 /* Report invalid types. */
4253 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4256 if (code == PREINCREMENT_EXPR)
4257 errstring ="no pre-increment operator for type";
4258 else if (code == POSTINCREMENT_EXPR)
4259 errstring ="no post-increment operator for type";
4260 else if (code == PREDECREMENT_EXPR)
4261 errstring ="no pre-decrement operator for type";
4263 errstring ="no post-decrement operator for type";
4267 /* Report something read-only. */
4269 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4270 || TREE_READONLY (arg))
4271 readonly_error (arg, ((code == PREINCREMENT_EXPR
4272 || code == POSTINCREMENT_EXPR)
4273 ? "increment" : "decrement"),
4279 tree result_type = TREE_TYPE (arg);
4281 declared_type = unlowered_expr_type (arg);
4283 arg = get_unwidened (arg, 0);
4284 argtype = TREE_TYPE (arg);
4286 /* ARM $5.2.5 last annotation says this should be forbidden. */
4287 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4288 pedwarn ("ISO C++ forbids %sing an enum",
4289 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4290 ? "increment" : "decrement");
4292 /* Compute the increment. */
4294 if (TREE_CODE (argtype) == POINTER_TYPE)
4296 tree type = complete_type (TREE_TYPE (argtype));
4298 if (!COMPLETE_OR_VOID_TYPE_P (type))
4299 error ("cannot %s a pointer to incomplete type %qT",
4300 ((code == PREINCREMENT_EXPR
4301 || code == POSTINCREMENT_EXPR)
4302 ? "increment" : "decrement"), TREE_TYPE (argtype));
4303 else if ((pedantic || warn_pointer_arith)
4304 && !TYPE_PTROB_P (argtype))
4305 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
4306 ((code == PREINCREMENT_EXPR
4307 || code == POSTINCREMENT_EXPR)
4308 ? "increment" : "decrement"), argtype);
4309 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4312 inc = integer_one_node;
4314 inc = cp_convert (argtype, inc);
4316 /* Handle incrementing a cast-expression. */
4318 switch (TREE_CODE (arg))
4323 case FIX_TRUNC_EXPR:
4324 case FIX_FLOOR_EXPR:
4325 case FIX_ROUND_EXPR:
4328 tree incremented, modify, value, compound;
4329 if (! lvalue_p (arg) && pedantic)
4330 pedwarn ("cast to non-reference type used as lvalue");
4331 arg = stabilize_reference (arg);
4332 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4335 value = save_expr (arg);
4336 incremented = build2 (((code == PREINCREMENT_EXPR
4337 || code == POSTINCREMENT_EXPR)
4338 ? PLUS_EXPR : MINUS_EXPR),
4339 argtype, value, inc);
4341 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4342 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4345 /* Eliminate warning about unused result of + or -. */
4346 TREE_NO_WARNING (compound) = 1;
4354 /* Complain about anything else that is not a true lvalue. */
4355 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4356 || code == POSTINCREMENT_EXPR)
4357 ? lv_increment : lv_decrement)))
4358 return error_mark_node;
4360 /* Forbid using -- on `bool'. */
4361 if (same_type_p (declared_type, boolean_type_node))
4363 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4365 error ("invalid use of %<--%> on bool variable %qD", arg);
4366 return error_mark_node;
4368 val = boolean_increment (code, arg);
4371 val = build2 (code, TREE_TYPE (arg), arg, inc);
4373 TREE_SIDE_EFFECTS (val) = 1;
4374 return cp_convert (result_type, val);
4378 /* Note that this operation never does default_conversion
4379 regardless of NOCONVERT. */
4381 argtype = lvalue_type (arg);
4383 if (TREE_CODE (arg) == OFFSET_REF)
4386 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4388 tree type = build_pointer_type (TREE_TYPE (argtype));
4389 arg = build1 (CONVERT_EXPR, type, arg);
4392 else if (pedantic && DECL_MAIN_P (arg))
4394 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4396 /* Let &* cancel out to simplify resulting code. */
4397 if (TREE_CODE (arg) == INDIRECT_REF)
4399 /* We don't need to have `current_class_ptr' wrapped in a
4400 NON_LVALUE_EXPR node. */
4401 if (arg == current_class_ref)
4402 return current_class_ptr;
4404 arg = TREE_OPERAND (arg, 0);
4405 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4407 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4408 arg = build1 (CONVERT_EXPR, type, arg);
4411 /* Don't let this be an lvalue. */
4416 /* Uninstantiated types are all functions. Taking the
4417 address of a function is a no-op, so just return the
4420 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4421 || !IDENTIFIER_OPNAME_P (arg));
4423 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4424 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4426 /* They're trying to take the address of a unique non-static
4427 member function. This is ill-formed (except in MS-land),
4428 but let's try to DTRT.
4429 Note: We only handle unique functions here because we don't
4430 want to complain if there's a static overload; non-unique
4431 cases will be handled by instantiate_type. But we need to
4432 handle this case here to allow casts on the resulting PMF.
4433 We could defer this in non-MS mode, but it's easier to give
4434 a useful error here. */
4436 /* Inside constant member functions, the `this' pointer
4437 contains an extra const qualifier. TYPE_MAIN_VARIANT
4438 is used here to remove this const from the diagnostics
4439 and the created OFFSET_REF. */
4440 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4441 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4444 if (! flag_ms_extensions)
4446 tree name = DECL_NAME (fn);
4447 if (current_class_type
4448 && TREE_OPERAND (arg, 0) == current_class_ref)
4449 /* An expression like &memfn. */
4450 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4451 " or parenthesized non-static member function to form"
4452 " a pointer to member function. Say %<&%T::%D%>",
4455 pedwarn ("ISO C++ forbids taking the address of a bound member"
4456 " function to form a pointer to member function."
4460 arg = build_offset_ref (base, fn, /*address_p=*/true);
4464 if (type_unknown_p (arg))
4465 return build1 (ADDR_EXPR, unknown_type_node, arg);
4467 /* Handle complex lvalues (when permitted)
4468 by reduction to simpler cases. */
4469 val = unary_complex_lvalue (code, arg);
4473 switch (TREE_CODE (arg))
4478 case FIX_TRUNC_EXPR:
4479 case FIX_FLOOR_EXPR:
4480 case FIX_ROUND_EXPR:
4482 if (! lvalue_p (arg) && pedantic)
4483 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4487 arg = BASELINK_FUNCTIONS (arg);
4491 arg = OVL_CURRENT (arg);
4495 /* Turn a reference to a non-static data member into a
4496 pointer-to-member. */
4501 if (!PTRMEM_OK_P (arg))
4502 return build_unary_op (code, arg, 0);
4504 t = TREE_OPERAND (arg, 1);
4505 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4507 error ("cannot create pointer to reference member %qD", t);
4508 return error_mark_node;
4511 type = build_ptrmem_type (context_for_name_lookup (t),
4513 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4521 /* Anything not already handled and not a true memory reference
4523 if (TREE_CODE (argtype) != FUNCTION_TYPE
4524 && TREE_CODE (argtype) != METHOD_TYPE
4525 && TREE_CODE (arg) != OFFSET_REF
4526 && !lvalue_or_else (arg, lv_addressof))
4527 return error_mark_node;
4529 if (argtype != error_mark_node)
4530 argtype = build_pointer_type (argtype);
4532 /* In a template, we are processing a non-dependent expression
4533 so we can just form an ADDR_EXPR with the correct type. */
4534 if (processing_template_decl)
4536 val = build_address (arg);
4537 if (TREE_CODE (arg) == OFFSET_REF)
4538 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4542 if (TREE_CODE (arg) != COMPONENT_REF)
4544 val = build_address (arg);
4545 if (TREE_CODE (arg) == OFFSET_REF)
4546 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4548 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4550 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4552 /* We can only get here with a single static member
4554 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4555 && DECL_STATIC_FUNCTION_P (fn));
4557 val = build_address (fn);
4558 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4559 /* Do not lose object's side effects. */
4560 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4561 TREE_OPERAND (arg, 0), val);
4563 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4565 error ("attempt to take address of bit-field structure member %qD",
4566 TREE_OPERAND (arg, 1));
4567 return error_mark_node;
4571 tree object = TREE_OPERAND (arg, 0);
4572 tree field = TREE_OPERAND (arg, 1);
4573 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4574 (TREE_TYPE (object), decl_type_context (field)));
4575 val = build_address (arg);
4578 if (TREE_CODE (argtype) == POINTER_TYPE
4579 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4581 build_ptrmemfunc_type (argtype);
4582 val = build_ptrmemfunc (argtype, val, 0,
4583 /*c_cast_p=*/false);
4595 argtype = TREE_TYPE (arg);
4596 return fold_if_not_in_template (build1 (code, argtype, arg));
4599 error ("%s", errstring);
4600 return error_mark_node;
4603 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4604 for certain kinds of expressions which are not really lvalues
4605 but which we can accept as lvalues.
4607 If ARG is not a kind of expression we can handle, return
4611 unary_complex_lvalue (enum tree_code code, tree arg)
4613 /* Inside a template, making these kinds of adjustments is
4614 pointless; we are only concerned with the type of the
4616 if (processing_template_decl)
4619 /* Handle (a, b) used as an "lvalue". */
4620 if (TREE_CODE (arg) == COMPOUND_EXPR)
4622 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4623 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4624 TREE_OPERAND (arg, 0), real_result);
4627 /* Handle (a ? b : c) used as an "lvalue". */
4628 if (TREE_CODE (arg) == COND_EXPR
4629 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4630 return rationalize_conditional_expr (code, arg);
4632 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4633 if (TREE_CODE (arg) == MODIFY_EXPR
4634 || TREE_CODE (arg) == PREINCREMENT_EXPR
4635 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4637 tree lvalue = TREE_OPERAND (arg, 0);
4638 if (TREE_SIDE_EFFECTS (lvalue))
4640 lvalue = stabilize_reference (lvalue);
4641 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4642 lvalue, TREE_OPERAND (arg, 1));
4644 return unary_complex_lvalue
4645 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4648 if (code != ADDR_EXPR)
4651 /* Handle (a = b) used as an "lvalue" for `&'. */
4652 if (TREE_CODE (arg) == MODIFY_EXPR
4653 || TREE_CODE (arg) == INIT_EXPR)
4655 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4656 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4658 TREE_NO_WARNING (arg) = 1;
4662 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4663 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4664 || TREE_CODE (arg) == OFFSET_REF)
4667 /* We permit compiler to make function calls returning
4668 objects of aggregate type look like lvalues. */
4672 if (TREE_CODE (targ) == SAVE_EXPR)
4673 targ = TREE_OPERAND (targ, 0);
4675 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4677 if (TREE_CODE (arg) == SAVE_EXPR)
4680 targ = build_cplus_new (TREE_TYPE (arg), arg);
4681 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4684 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4685 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4686 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4689 /* Don't let anything else be handled specially. */
4693 /* Mark EXP saying that we need to be able to take the
4694 address of it; it should not be allocated in a register.
4695 Value is true if successful.
4697 C++: we do not allow `current_class_ptr' to be addressable. */
4700 cxx_mark_addressable (tree exp)
4705 switch (TREE_CODE (x))
4712 x = TREE_OPERAND (x, 0);
4716 if (x == current_class_ptr)
4718 error ("cannot take the address of %<this%>, which is an rvalue expression");
4719 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4725 /* Caller should not be trying to mark initialized
4726 constant fields addressable. */
4727 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4728 || DECL_IN_AGGR_P (x) == 0
4730 || DECL_EXTERNAL (x));
4735 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4736 && !DECL_ARTIFICIAL (x))
4738 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4741 ("address of explicit register variable %qD requested", x);
4744 else if (extra_warnings)
4746 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4748 TREE_ADDRESSABLE (x) = 1;
4752 TREE_ADDRESSABLE (x) = 1;
4756 TREE_ADDRESSABLE (x) = 1;
4760 TREE_ADDRESSABLE (x) = 1;
4761 cxx_mark_addressable (TREE_OPERAND (x, 0));
4769 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4772 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4774 tree orig_ifexp = ifexp;
4775 tree orig_op1 = op1;
4776 tree orig_op2 = op2;
4779 if (processing_template_decl)
4781 /* The standard says that the expression is type-dependent if
4782 IFEXP is type-dependent, even though the eventual type of the
4783 expression doesn't dependent on IFEXP. */
4784 if (type_dependent_expression_p (ifexp)
4785 /* As a GNU extension, the middle operand may be omitted. */
4786 || (op1 && type_dependent_expression_p (op1))
4787 || type_dependent_expression_p (op2))
4788 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4789 ifexp = build_non_dependent_expr (ifexp);
4791 op1 = build_non_dependent_expr (op1);
4792 op2 = build_non_dependent_expr (op2);
4795 expr = build_conditional_expr (ifexp, op1, op2);
4796 if (processing_template_decl && expr != error_mark_node)
4797 return build_min_non_dep (COND_EXPR, expr,
4798 orig_ifexp, orig_op1, orig_op2);
4802 /* Given a list of expressions, return a compound expression
4803 that performs them all and returns the value of the last of them. */
4805 tree build_x_compound_expr_from_list (tree list, const char *msg)
4807 tree expr = TREE_VALUE (list);
4809 if (TREE_CHAIN (list))
4812 pedwarn ("%s expression list treated as compound expression", msg);
4814 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4815 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4821 /* Handle overloading of the ',' operator when needed. */
4824 build_x_compound_expr (tree op1, tree op2)
4827 tree orig_op1 = op1;
4828 tree orig_op2 = op2;
4830 if (processing_template_decl)
4832 if (type_dependent_expression_p (op1)
4833 || type_dependent_expression_p (op2))
4834 return build_min_nt (COMPOUND_EXPR, op1, op2);
4835 op1 = build_non_dependent_expr (op1);
4836 op2 = build_non_dependent_expr (op2);
4839 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4840 /*overloaded_p=*/NULL);
4842 result = build_compound_expr (op1, op2);
4844 if (processing_template_decl && result != error_mark_node)
4845 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4850 /* Build a compound expression. */
4853 build_compound_expr (tree lhs, tree rhs)
4855 lhs = convert_to_void (lhs, "left-hand operand of comma");
4857 if (lhs == error_mark_node || rhs == error_mark_node)
4858 return error_mark_node;
4860 if (TREE_CODE (rhs) == TARGET_EXPR)
4862 /* If the rhs is a TARGET_EXPR, then build the compound
4863 expression inside the target_expr's initializer. This
4864 helps the compiler to eliminate unnecessary temporaries. */
4865 tree init = TREE_OPERAND (rhs, 1);
4867 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4868 TREE_OPERAND (rhs, 1) = init;
4873 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4876 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4877 casts away constness. DIAG_FN gives the function to call if we
4878 need to issue a diagnostic; if it is NULL, no diagnostic will be
4879 issued. DESCRIPTION explains what operation is taking place. */
4882 check_for_casting_away_constness (tree src_type, tree dest_type,
4883 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4884 const char *description)
4886 if (diag_fn && casts_away_constness (src_type, dest_type))
4887 diag_fn ("%s from type %qT to type %qT casts away constness",
4888 description, src_type, dest_type);
4891 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4892 (another pointer-to-member type in the same hierarchy) and return
4893 the converted expression. If ALLOW_INVERSE_P is permitted, a
4894 pointer-to-derived may be converted to pointer-to-base; otherwise,
4895 only the other direction is permitted. If C_CAST_P is true, this
4896 conversion is taking place as part of a C-style cast. */
4899 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4902 if (TYPE_PTRMEM_P (type))
4906 if (TREE_CODE (expr) == PTRMEM_CST)
4907 expr = cplus_expand_constant (expr);
4908 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4909 TYPE_PTRMEM_CLASS_TYPE (type),
4912 if (!integer_zerop (delta))
4913 expr = cp_build_binary_op (PLUS_EXPR,
4914 build_nop (ptrdiff_type_node, expr),
4916 return build_nop (type, expr);
4919 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4920 allow_inverse_p, c_cast_p);
4923 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4924 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4925 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4928 ignore_overflows (tree expr, tree orig)
4930 if (TREE_CODE (expr) == INTEGER_CST
4931 && CONSTANT_CLASS_P (orig)
4932 && TREE_CODE (orig) != STRING_CST
4933 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4934 || TREE_CONSTANT_OVERFLOW (expr)
4935 != TREE_CONSTANT_OVERFLOW (orig)))
4937 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4938 /* Ensure constant sharing. */
4939 expr = build_int_cst_wide (TREE_TYPE (expr),
4940 TREE_INT_CST_LOW (expr),
4941 TREE_INT_CST_HIGH (expr));
4944 /* Avoid clobbering a shared constant. */
4945 expr = copy_node (expr);
4946 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4947 TREE_CONSTANT_OVERFLOW (expr)
4948 = TREE_CONSTANT_OVERFLOW (orig);
4954 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4955 this static_cast is being attempted as one of the possible casts
4956 allowed by a C-style cast. (In that case, accessibility of base
4957 classes is not considered, and it is OK to cast away
4958 constness.) Return the result of the cast. *VALID_P is set to
4959 indicate whether or not the cast was valid. */
4962 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4968 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4971 /* Assume the cast is valid. */
4974 intype = TREE_TYPE (expr);
4976 /* Save casted types in the function's used types hash table. */
4977 used_types_insert (type);
4979 /* Determine what to do when casting away constness. */
4982 /* C-style casts are allowed to cast away constness. With
4983 WARN_CAST_QUAL, we still want to issue a warning. */
4984 diag_fn = warn_cast_qual ? warning0 : NULL;
4989 /* A static_cast may not cast away constness. */
4991 desc = "static_cast";
4994 /* [expr.static.cast]
4996 An lvalue of type "cv1 B", where B is a class type, can be cast
4997 to type "reference to cv2 D", where D is a class derived (clause
4998 _class.derived_) from B, if a valid standard conversion from
4999 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
5000 same cv-qualification as, or greater cv-qualification than, cv1,
5001 and B is not a virtual base class of D. */
5002 /* We check this case before checking the validity of "TYPE t =
5003 EXPR;" below because for this case:
5006 struct D : public B { D(const B&); };
5008 void f() { static_cast<const D&>(b); }
5010 we want to avoid constructing a new D. The standard is not
5011 completely clear about this issue, but our interpretation is
5012 consistent with other compilers. */
5013 if (TREE_CODE (type) == REFERENCE_TYPE
5014 && CLASS_TYPE_P (TREE_TYPE (type))
5015 && CLASS_TYPE_P (intype)
5016 && real_lvalue_p (expr)
5017 && DERIVED_FROM_P (intype, TREE_TYPE (type))
5018 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
5019 build_pointer_type (TYPE_MAIN_VARIANT
5020 (TREE_TYPE (type))))
5022 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5026 /* There is a standard conversion from "D*" to "B*" even if "B"
5027 is ambiguous or inaccessible. If this is really a
5028 static_cast, then we check both for inaccessibility and
5029 ambiguity. However, if this is a static_cast being performed
5030 because the user wrote a C-style cast, then accessibility is
5032 base = lookup_base (TREE_TYPE (type), intype,
5033 c_cast_p ? ba_unique : ba_check,
5036 /* Convert from "B*" to "D*". This function will check that "B"
5037 is not a virtual base of "D". */
5038 expr = build_base_path (MINUS_EXPR, build_address (expr),
5039 base, /*nonnull=*/false);
5040 /* Convert the pointer to a reference -- but then remember that
5041 there are no expressions with reference type in C++. */
5042 return convert_from_reference (build_nop (type, expr));
5047 /* [expr.static.cast]
5049 An expression e can be explicitly converted to a type T using a
5050 static_cast of the form static_cast<T>(e) if the declaration T
5051 t(e);" is well-formed, for some invented temporary variable
5053 result = perform_direct_initialization_if_possible (type, expr,
5057 result = convert_from_reference (result);
5059 /* Ignore any integer overflow caused by the cast. */
5060 result = ignore_overflows (result, orig);
5062 /* [expr.static.cast]
5064 If T is a reference type, the result is an lvalue; otherwise,
5065 the result is an rvalue. */
5066 if (TREE_CODE (type) != REFERENCE_TYPE)
5067 result = rvalue (result);
5071 /* [expr.static.cast]
5073 Any expression can be explicitly converted to type cv void. */
5074 if (TREE_CODE (type) == VOID_TYPE)
5075 return convert_to_void (expr, /*implicit=*/NULL);
5077 /* [expr.static.cast]
5079 The inverse of any standard conversion sequence (clause _conv_),
5080 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5081 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5082 (_conv.bool_) conversions, can be performed explicitly using
5083 static_cast subject to the restriction that the explicit
5084 conversion does not cast away constness (_expr.const.cast_), and
5085 the following additional rules for specific cases: */
5086 /* For reference, the conversions not excluded are: integral
5087 promotions, floating point promotion, integral conversions,
5088 floating point conversions, floating-integral conversions,
5089 pointer conversions, and pointer to member conversions. */
5092 A value of integral _or enumeration_ type can be explicitly
5093 converted to an enumeration type. */
5094 /* The effect of all that is that any conversion between any two
5095 types which are integral, floating, or enumeration types can be
5097 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5098 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5100 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5102 /* Ignore any integer overflow caused by the cast. */
5103 expr = ignore_overflows (expr, orig);
5107 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5108 && CLASS_TYPE_P (TREE_TYPE (type))
5109 && CLASS_TYPE_P (TREE_TYPE (intype))
5110 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5111 (TREE_TYPE (intype))),
5112 build_pointer_type (TYPE_MAIN_VARIANT
5113 (TREE_TYPE (type)))))
5118 check_for_casting_away_constness (intype, type, diag_fn, desc);
5119 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5120 c_cast_p ? ba_unique : ba_check,
5122 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5125 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5126 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5133 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5134 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5136 if (TYPE_PTRMEM_P (type))
5138 t1 = (build_ptrmem_type
5140 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5141 t2 = (build_ptrmem_type
5143 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5150 if (can_convert (t1, t2))
5153 check_for_casting_away_constness (intype, type, diag_fn,
5155 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5160 /* [expr.static.cast]
5162 An rvalue of type "pointer to cv void" can be explicitly
5163 converted to a pointer to object type. A value of type pointer
5164 to object converted to "pointer to cv void" and back to the
5165 original pointer type will have its original value. */
5166 if (TREE_CODE (intype) == POINTER_TYPE
5167 && VOID_TYPE_P (TREE_TYPE (intype))
5168 && TYPE_PTROB_P (type))
5171 check_for_casting_away_constness (intype, type, diag_fn, desc);
5172 return build_nop (type, expr);
5176 return error_mark_node;
5179 /* Return an expression representing static_cast<TYPE>(EXPR). */
5182 build_static_cast (tree type, tree expr)
5187 if (type == error_mark_node || expr == error_mark_node)
5188 return error_mark_node;
5190 if (processing_template_decl)
5192 expr = build_min (STATIC_CAST_EXPR, type, expr);
5193 /* We don't know if it will or will not have side effects. */
5194 TREE_SIDE_EFFECTS (expr) = 1;
5195 return convert_from_reference (expr);
5198 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5199 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5200 if (TREE_CODE (type) != REFERENCE_TYPE
5201 && TREE_CODE (expr) == NOP_EXPR
5202 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5203 expr = TREE_OPERAND (expr, 0);
5205 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5209 error ("invalid static_cast from type %qT to type %qT",
5210 TREE_TYPE (expr), type);
5211 return error_mark_node;
5214 /* EXPR is an expression with member function or pointer-to-member
5215 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5216 not permitted by ISO C++, but we accept it in some modes. If we
5217 are not in one of those modes, issue a diagnostic. Return the
5218 converted expression. */
5221 convert_member_func_to_ptr (tree type, tree expr)
5226 intype = TREE_TYPE (expr);
5227 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5228 || TREE_CODE (intype) == METHOD_TYPE);
5230 if (pedantic || warn_pmf2ptr)
5231 pedwarn ("converting from %qT to %qT", intype, type);
5233 if (TREE_CODE (intype) == METHOD_TYPE)
5234 expr = build_addr_func (expr);
5235 else if (TREE_CODE (expr) == PTRMEM_CST)
5236 expr = build_address (PTRMEM_CST_MEMBER (expr));
5239 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5240 decl = build_address (decl);
5241 expr = get_member_function_from_ptrfunc (&decl, expr);
5244 return build_nop (type, expr);
5247 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5248 If C_CAST_P is true, this reinterpret cast is being done as part of
5249 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5250 indicate whether or not reinterpret_cast was valid. */
5253 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5258 /* Assume the cast is invalid. */
5262 if (type == error_mark_node || error_operand_p (expr))
5263 return error_mark_node;
5265 intype = TREE_TYPE (expr);
5267 /* Save casted types in the function's used types hash table. */
5268 used_types_insert (type);
5270 /* [expr.reinterpret.cast]
5271 An lvalue expression of type T1 can be cast to the type
5272 "reference to T2" if an expression of type "pointer to T1" can be
5273 explicitly converted to the type "pointer to T2" using a
5274 reinterpret_cast. */
5275 if (TREE_CODE (type) == REFERENCE_TYPE)
5277 if (! real_lvalue_p (expr))
5279 error ("invalid cast of an rvalue expression of type "
5282 return error_mark_node;
5285 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5286 "B" are related class types; the reinterpret_cast does not
5287 adjust the pointer. */
5288 if (TYPE_PTR_P (intype)
5289 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5290 COMPARE_BASE | COMPARE_DERIVED)))
5291 warning (0, "casting %qT to %qT does not dereference pointer",
5294 expr = build_unary_op (ADDR_EXPR, expr, 0);
5295 if (expr != error_mark_node)
5296 expr = build_reinterpret_cast_1
5297 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5299 if (expr != error_mark_node)
5300 expr = build_indirect_ref (expr, 0);
5304 /* As a G++ extension, we consider conversions from member
5305 functions, and pointers to member functions to
5306 pointer-to-function and pointer-to-void types. If
5307 -Wno-pmf-conversions has not been specified,
5308 convert_member_func_to_ptr will issue an error message. */
5309 if ((TYPE_PTRMEMFUNC_P (intype)
5310 || TREE_CODE (intype) == METHOD_TYPE)
5311 && TYPE_PTR_P (type)
5312 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5313 || VOID_TYPE_P (TREE_TYPE (type))))
5314 return convert_member_func_to_ptr (type, expr);
5316 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5317 array-to-pointer, and function-to-pointer conversions are
5319 expr = decay_conversion (expr);
5321 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5322 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5323 if (TREE_CODE (expr) == NOP_EXPR
5324 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5325 expr = TREE_OPERAND (expr, 0);
5327 if (error_operand_p (expr))
5328 return error_mark_node;
5330 intype = TREE_TYPE (expr);
5332 /* [expr.reinterpret.cast]
5333 A pointer can be converted to any integral type large enough to
5335 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5337 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5338 pedwarn ("cast from %qT to %qT loses precision",
5341 /* [expr.reinterpret.cast]
5342 A value of integral or enumeration type can be explicitly
5343 converted to a pointer. */
5344 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5347 /* APPLE LOCAL begin blocks 6040305 (ck) */
5348 else if (TREE_CODE (type) == INTEGER_TYPE && TREE_CODE (intype) == BLOCK_POINTER_TYPE)
5350 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5351 pedwarn ("cast from %qT to %qT loses precision",
5354 else if (TREE_CODE (type) == BLOCK_POINTER_TYPE && TREE_CODE (intype) == INTEGER_TYPE)
5357 else if (TREE_CODE (type) == BLOCK_POINTER_TYPE && TREE_CODE (intype) == BLOCK_POINTER_TYPE)
5360 else if (TREE_CODE (intype) == BLOCK_POINTER_TYPE
5361 && (objc_is_id (type)
5362 || (TREE_CODE (type) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (type)))))
5365 else if (TREE_CODE (type) == BLOCK_POINTER_TYPE
5366 && TREE_CODE (intype) == POINTER_TYPE
5367 && (objc_is_id (intype) || VOID_TYPE_P (TREE_TYPE (intype))))
5370 /* APPLE LOCAL end blocks 6040305 (ck) */
5371 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5372 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5373 return fold_if_not_in_template (build_nop (type, expr));
5374 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5375 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5380 check_for_casting_away_constness (intype, type, error,
5381 "reinterpret_cast");
5382 /* Warn about possible alignment problems. */
5383 if (STRICT_ALIGNMENT && warn_cast_align
5384 && !VOID_TYPE_P (type)
5385 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5386 && COMPLETE_TYPE_P (TREE_TYPE (type))
5387 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5388 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5389 warning (0, "cast from %qT to %qT increases required alignment of "
5393 /* We need to strip nops here, because the frontend likes to
5394 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5396 if (warn_strict_aliasing <= 2)
5397 strict_aliasing_warning (intype, type, sexpr);
5399 return fold_if_not_in_template (build_nop (type, expr));
5401 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5402 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5405 /* Only issue a warning, as we have always supported this
5406 where possible, and it is necessary in some cases. DR 195
5407 addresses this issue, but as of 2004/10/26 is still in
5409 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5410 return fold_if_not_in_template (build_nop (type, expr));
5412 else if (TREE_CODE (type) == VECTOR_TYPE)
5413 return fold_if_not_in_template (convert_to_vector (type, expr));
5414 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5415 return fold_if_not_in_template (convert_to_integer (type, expr));
5420 error ("invalid cast from type %qT to type %qT", intype, type);
5421 return error_mark_node;
5424 /* APPLE LOCAL begin don't sign-extend pointers cast to integers */
5425 if (TREE_CODE (type) == INTEGER_TYPE
5426 && TREE_CODE (intype) == POINTER_TYPE
5427 && TYPE_PRECISION (type) > TYPE_PRECISION (intype)
5428 && TYPE_UNSIGNED (type))
5429 expr = cp_convert (c_common_type_for_size (POINTER_SIZE, 1), expr);
5430 /* APPLE LOCAL end don't sign-extend pointers cast to integers */
5432 return cp_convert (type, expr);
5436 build_reinterpret_cast (tree type, tree expr)
5438 if (type == error_mark_node || expr == error_mark_node)
5439 return error_mark_node;
5441 if (processing_template_decl)
5443 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5445 if (!TREE_SIDE_EFFECTS (t)
5446 && type_dependent_expression_p (expr))
5447 /* There might turn out to be side effects inside expr. */
5448 TREE_SIDE_EFFECTS (t) = 1;
5449 return convert_from_reference (t);
5452 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5456 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5457 return an appropriate expression. Otherwise, return
5458 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5459 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5460 performing a C-style cast, its value upon return will indicate
5461 whether or not the conversion succeeded. */
5464 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5468 tree reference_type;
5470 /* Callers are responsible for handling error_mark_node as a
5471 destination type. */
5472 gcc_assert (dst_type != error_mark_node);
5473 /* In a template, callers should be building syntactic
5474 representations of casts, not using this machinery. */
5475 gcc_assert (!processing_template_decl);
5477 /* Assume the conversion is invalid. */
5481 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5484 error ("invalid use of const_cast with type %qT, "
5485 "which is not a pointer, "
5486 "reference, nor a pointer-to-data-member type", dst_type);
5487 return error_mark_node;
5490 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5493 error ("invalid use of const_cast with type %qT, which is a pointer "
5494 "or reference to a function type", dst_type);
5495 return error_mark_node;
5498 /* Save casted types in the function's used types hash table. */
5499 used_types_insert (dst_type);
5501 src_type = TREE_TYPE (expr);
5502 /* Expressions do not really have reference types. */
5503 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5504 src_type = TREE_TYPE (src_type);
5506 /* [expr.const.cast]
5508 An lvalue of type T1 can be explicitly converted to an lvalue of
5509 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5510 types) if a pointer to T1 can be explicitly converted to the type
5511 pointer to T2 using a const_cast. */
5512 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5514 reference_type = dst_type;
5515 if (! real_lvalue_p (expr))
5518 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5519 src_type, dst_type);
5520 return error_mark_node;
5522 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5523 src_type = build_pointer_type (src_type);
5527 reference_type = NULL_TREE;
5528 /* If the destination type is not a reference type, the
5529 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5530 conversions are performed. */
5531 src_type = type_decays_to (src_type);
5532 if (src_type == error_mark_node)
5533 return error_mark_node;
5536 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5537 && comp_ptr_ttypes_const (dst_type, src_type))
5542 /* This cast is actually a C-style cast. Issue a warning if
5543 the user is making a potentially unsafe cast. */
5545 check_for_casting_away_constness (src_type, dst_type,
5551 expr = build_unary_op (ADDR_EXPR, expr, 0);
5552 expr = build_nop (reference_type, expr);
5553 return convert_from_reference (expr);
5557 expr = decay_conversion (expr);
5558 /* build_c_cast puts on a NOP_EXPR to make the result not an
5559 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5560 non-lvalue context. */
5561 if (TREE_CODE (expr) == NOP_EXPR
5562 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5563 expr = TREE_OPERAND (expr, 0);
5564 return build_nop (dst_type, expr);
5569 error ("invalid const_cast from type %qT to type %qT",
5570 src_type, dst_type);
5571 return error_mark_node;
5575 build_const_cast (tree type, tree expr)
5577 if (type == error_mark_node || error_operand_p (expr))
5578 return error_mark_node;
5580 if (processing_template_decl)
5582 tree t = build_min (CONST_CAST_EXPR, type, expr);
5584 if (!TREE_SIDE_EFFECTS (t)
5585 && type_dependent_expression_p (expr))
5586 /* There might turn out to be side effects inside expr. */
5587 TREE_SIDE_EFFECTS (t) = 1;
5588 return convert_from_reference (t);
5591 return build_const_cast_1 (type, expr, /*complain=*/true,
5595 /* Build an expression representing an explicit C-style cast to type
5596 TYPE of expression EXPR. */
5599 build_c_cast (tree type, tree expr)
5605 if (type == error_mark_node || error_operand_p (expr))
5606 return error_mark_node;
5608 if (processing_template_decl)
5610 tree t = build_min (CAST_EXPR, type,
5611 tree_cons (NULL_TREE, value, NULL_TREE));
5612 /* We don't know if it will or will not have side effects. */
5613 TREE_SIDE_EFFECTS (t) = 1;
5614 return convert_from_reference (t);
5617 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5618 'Class') should always be retained, because this information aids
5619 in method lookup. */
5620 if (objc_is_object_ptr (type)
5621 && objc_is_object_ptr (TREE_TYPE (expr)))
5622 return build_nop (type, expr);
5624 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5625 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5626 if (TREE_CODE (type) != REFERENCE_TYPE
5627 && TREE_CODE (value) == NOP_EXPR
5628 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5629 value = TREE_OPERAND (value, 0);
5631 if (TREE_CODE (type) == ARRAY_TYPE)
5633 /* Allow casting from T1* to T2[] because Cfront allows it.
5634 NIHCL uses it. It is not valid ISO C++ however. */
5635 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5637 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5638 type = build_pointer_type (TREE_TYPE (type));
5642 error ("ISO C++ forbids casting to an array type %qT", type);
5643 return error_mark_node;
5647 if (TREE_CODE (type) == FUNCTION_TYPE
5648 || TREE_CODE (type) == METHOD_TYPE)
5650 error ("invalid cast to function type %qT", type);
5651 return error_mark_node;
5654 /* A C-style cast can be a const_cast. */
5655 result = build_const_cast_1 (type, value, /*complain=*/false,
5660 /* Or a static cast. */
5661 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5663 /* Or a reinterpret_cast. */
5665 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5667 /* The static_cast or reinterpret_cast may be followed by a
5670 /* A valid cast may result in errors if, for example, a
5671 conversion to am ambiguous base class is required. */
5672 && !error_operand_p (result))
5676 /* Non-class rvalues always have cv-unqualified type. */
5677 if (!CLASS_TYPE_P (type))
5678 type = TYPE_MAIN_VARIANT (type);
5679 result_type = TREE_TYPE (result);
5680 if (!CLASS_TYPE_P (result_type))
5681 result_type = TYPE_MAIN_VARIANT (result_type);
5682 /* If the type of RESULT does not match TYPE, perform a
5683 const_cast to make it match. If the static_cast or
5684 reinterpret_cast succeeded, we will differ by at most
5685 cv-qualification, so the follow-on const_cast is guaranteed
5687 if (!same_type_p (non_reference (type), non_reference (result_type)))
5689 result = build_const_cast_1 (type, result, false, &valid_p);
5690 gcc_assert (valid_p);
5695 return error_mark_node;
5698 /* Build an assignment expression of lvalue LHS from value RHS.
5699 MODIFYCODE is the code for a binary operator that we use
5700 to combine the old value of LHS with RHS to get the new value.
5701 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5703 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5706 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5710 tree lhstype = TREE_TYPE (lhs);
5711 tree olhstype = lhstype;
5712 tree olhs = NULL_TREE;
5713 bool plain_assign = (modifycode == NOP_EXPR);
5715 /* Avoid duplicate error messages from operands that had errors. */
5716 if (error_operand_p (lhs) || error_operand_p (rhs))
5717 return error_mark_node;
5719 /* Handle control structure constructs used as "lvalues". */
5720 switch (TREE_CODE (lhs))
5722 /* Handle --foo = 5; as these are valid constructs in C++. */
5723 case PREDECREMENT_EXPR:
5724 case PREINCREMENT_EXPR:
5725 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5726 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5727 stabilize_reference (TREE_OPERAND (lhs, 0)),
5728 TREE_OPERAND (lhs, 1));
5729 return build2 (COMPOUND_EXPR, lhstype,
5731 build_modify_expr (TREE_OPERAND (lhs, 0),
5734 /* Handle (a, b) used as an "lvalue". */
5736 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5738 if (newrhs == error_mark_node)
5739 return error_mark_node;
5740 return build2 (COMPOUND_EXPR, lhstype,
5741 TREE_OPERAND (lhs, 0), newrhs);
5744 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5745 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5746 stabilize_reference (TREE_OPERAND (lhs, 0)),
5747 TREE_OPERAND (lhs, 1));
5748 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5749 if (newrhs == error_mark_node)
5750 return error_mark_node;
5751 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5755 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5756 when neither operand has side-effects. */
5757 if (!lvalue_or_else (lhs, lv_assign))
5758 return error_mark_node;
5760 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5761 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5763 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5764 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5766 TREE_OPERAND (lhs, 0),
5767 TREE_OPERAND (lhs, 1)),
5768 TREE_OPERAND (lhs, 0),
5769 TREE_OPERAND (lhs, 1));
5772 /* Handle (a ? b : c) used as an "lvalue". */
5775 /* Produce (a ? (b = rhs) : (c = rhs))
5776 except that the RHS goes through a save-expr
5777 so the code to compute it is only emitted once. */
5779 tree preeval = NULL_TREE;
5781 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5783 error ("void value not ignored as it ought to be");
5784 return error_mark_node;
5787 rhs = stabilize_expr (rhs, &preeval);
5789 /* Check this here to avoid odd errors when trying to convert
5790 a throw to the type of the COND_EXPR. */
5791 if (!lvalue_or_else (lhs, lv_assign))
5792 return error_mark_node;
5794 cond = build_conditional_expr
5795 (TREE_OPERAND (lhs, 0),
5796 build_modify_expr (TREE_OPERAND (lhs, 1),
5798 build_modify_expr (TREE_OPERAND (lhs, 2),
5801 if (cond == error_mark_node)
5803 /* Make sure the code to compute the rhs comes out
5804 before the split. */
5806 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5814 if (modifycode == INIT_EXPR)
5816 if (TREE_CODE (rhs) == CONSTRUCTOR)
5818 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5819 /* Call convert to generate an error; see PR 11063. */
5820 rhs = convert (lhstype, rhs);
5821 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5822 TREE_SIDE_EFFECTS (result) = 1;
5825 else if (! IS_AGGR_TYPE (lhstype))
5826 /* Do the default thing. */;
5829 result = build_special_member_call (lhs, complete_ctor_identifier,
5830 build_tree_list (NULL_TREE, rhs),
5831 lhstype, LOOKUP_NORMAL);
5832 if (result == NULL_TREE)
5833 return error_mark_node;
5839 lhs = require_complete_type (lhs);
5840 if (lhs == error_mark_node)
5841 return error_mark_node;
5843 if (modifycode == NOP_EXPR)
5845 /* `operator=' is not an inheritable operator. */
5846 if (! IS_AGGR_TYPE (lhstype))
5847 /* Do the default thing. */;
5850 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5851 lhs, rhs, make_node (NOP_EXPR),
5852 /*overloaded_p=*/NULL);
5853 if (result == NULL_TREE)
5854 return error_mark_node;
5857 /* APPLE LOCAL end C* property (Radar 4436866) */
5858 /* `operator=' is not an inheritable operator. */
5859 if (! IS_AGGR_TYPE (lhstype))
5860 /* Do the default thing. */;
5863 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5864 lhs, rhs, make_node (NOP_EXPR),
5865 /*overloaded_p=*/NULL);
5866 if (result == NULL_TREE)
5867 return error_mark_node;
5874 /* A binary op has been requested. Combine the old LHS
5875 value with the RHS producing the value we should actually
5876 store into the LHS. */
5878 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5879 lhs = stabilize_reference (lhs);
5880 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5881 if (newrhs == error_mark_node)
5883 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5884 TREE_TYPE (lhs), TREE_TYPE (rhs));
5885 return error_mark_node;
5888 /* Now it looks like a plain assignment. */
5889 modifycode = NOP_EXPR;
5892 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5893 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5896 /* The left-hand side must be an lvalue. */
5897 if (!lvalue_or_else (lhs, lv_assign))
5898 return error_mark_node;
5900 /* Warn about modifying something that is `const'. Don't warn if
5901 this is initialization. */
5902 if (modifycode != INIT_EXPR
5903 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5904 /* Functions are not modifiable, even though they are
5906 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5907 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5908 /* If it's an aggregate and any field is const, then it is
5909 effectively const. */
5910 || (CLASS_TYPE_P (lhstype)
5911 && C_TYPE_FIELDS_READONLY (lhstype))))
5912 readonly_error (lhs, "assignment", 0);
5914 /* If storing into a structure or union member, it has probably been
5915 given type `int'. Compute the type that would go with the actual
5916 amount of storage the member occupies. */
5918 if (TREE_CODE (lhs) == COMPONENT_REF
5919 && (TREE_CODE (lhstype) == INTEGER_TYPE
5920 || TREE_CODE (lhstype) == REAL_TYPE
5921 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5923 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5925 /* If storing in a field that is in actuality a short or narrower
5926 than one, we must store in the field in its actual type. */
5928 if (lhstype != TREE_TYPE (lhs))
5930 /* Avoid warnings converting integral types back into enums for
5932 if (TREE_CODE (lhstype) == INTEGER_TYPE
5933 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5935 if (TREE_SIDE_EFFECTS (lhs))
5936 lhs = stabilize_reference (lhs);
5939 lhs = copy_node (lhs);
5940 TREE_TYPE (lhs) = lhstype;
5944 /* Convert new value to destination type. */
5946 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5950 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5951 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5953 error ("incompatible types in assignment of %qT to %qT",
5954 TREE_TYPE (rhs), lhstype);
5955 return error_mark_node;
5958 /* Allow array assignment in compiler-generated code. */
5959 if (! DECL_ARTIFICIAL (current_function_decl))
5961 /* This routine is used for both initialization and assignment.
5962 Make sure the diagnostic message differentiates the context. */
5963 if (modifycode == INIT_EXPR)
5964 error ("array used as initializer");
5966 error ("invalid array assignment");
5967 return error_mark_node;
5970 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5971 ? 1 + (modifycode != INIT_EXPR): 0;
5972 return build_vec_init (lhs, NULL_TREE, newrhs,
5973 /*explicit_default_init_p=*/false,
5977 if (modifycode == INIT_EXPR)
5978 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5979 "initialization", NULL_TREE, 0);
5982 /* Avoid warnings on enum bit fields. */
5983 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5984 && TREE_CODE (lhstype) == INTEGER_TYPE)
5986 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5988 newrhs = convert_force (lhstype, newrhs, 0);
5991 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5993 if (TREE_CODE (newrhs) == CALL_EXPR
5994 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5995 newrhs = build_cplus_new (lhstype, newrhs);
5997 /* Can't initialize directly from a TARGET_EXPR, since that would
5998 cause the lhs to be constructed twice, and possibly result in
5999 accidental self-initialization. So we force the TARGET_EXPR to be
6000 expanded without a target. */
6001 if (TREE_CODE (newrhs) == TARGET_EXPR)
6002 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
6003 TREE_OPERAND (newrhs, 0));
6006 if (newrhs == error_mark_node)
6007 return error_mark_node;
6009 if (c_dialect_objc () && flag_objc_gc)
6011 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
6017 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
6018 lhstype, lhs, newrhs);
6020 TREE_SIDE_EFFECTS (result) = 1;
6022 TREE_NO_WARNING (result) = 1;
6024 /* If we got the LHS in a different type for storing in,
6025 convert the result back to the nominal type of LHS
6026 so that the value we return always has the same type
6027 as the LHS argument. */
6029 if (olhstype == TREE_TYPE (result))
6033 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
6034 TREE_NO_WARNING (result) = 1;
6037 return convert_for_assignment (olhstype, result, "assignment",
6042 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
6044 /* APPLE LOCAL __block assign sequence point 6639533 */
6045 bool insert_sequence_point = false;
6047 if (processing_template_decl)
6048 return build_min_nt (MODOP_EXPR, lhs,
6049 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
6051 /* APPLE LOCAL begin __block assign sequence point 6639533 */
6052 /* For byref = x;, we have to transform this into ({ typeof(x) x' =
6053 x; byref = x`; )} to ensure there is a sequence point before the
6054 evaluation of the byref, inorder to ensure that the access
6055 expression for byref doesn't start running before x is evaluated,
6056 as it will access the __forwarding pointer and that must be done
6057 after x is evaluated. */
6058 /* First we check to see if lhs is a byref... byrefs look like:
6059 __Block_byref_X.__forwarding->x */
6060 if (TREE_CODE (lhs) == COMPONENT_REF)
6062 tree inner = TREE_OPERAND (lhs, 0);
6063 /* now check for -> */
6064 if (TREE_CODE (inner) == INDIRECT_REF)
6066 inner = TREE_OPERAND (inner, 0);
6067 if (TREE_CODE (inner) == COMPONENT_REF)
6069 inner = TREE_OPERAND (inner, 0);
6070 if (TREE_CODE (inner) == VAR_DECL
6071 && COPYABLE_BYREF_LOCAL_VAR (inner))
6074 /* then we save the rhs. */
6075 rhs = save_expr (rhs);
6077 /* And arrange for the sequence point to be inserted. */
6078 insert_sequence_point = true;
6083 /* APPLE LOCAL end __block assign sequence point 6639533 */
6085 if (modifycode != NOP_EXPR)
6087 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
6088 make_node (modifycode),
6089 /*overloaded_p=*/NULL);
6092 /* APPLE LOCAL begin __block assign sequence point 6639533 */
6093 if (insert_sequence_point)
6094 rval = build2 (COMPOUND_EXPR, TREE_TYPE (rval), rhs, rval);
6095 /* APPLE LOCAL end __block assign sequence point 6639533 */
6096 TREE_NO_WARNING (rval) = 1;
6100 lhs = build_modify_expr (lhs, modifycode, rhs);
6101 /* APPLE LOCAL begin __block assign sequence point 6639533 */
6102 if (insert_sequence_point)
6103 lhs = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), rhs, lhs);
6104 /* APPLE LOCAL end __block assign sequence point 6639533 */
6109 /* Get difference in deltas for different pointer to member function
6110 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6111 the conversion is invalid, the constant is zero. If
6112 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6113 If C_CAST_P is true this conversion is taking place as part of a
6116 Note that the naming of FROM and TO is kind of backwards; the return
6117 value is what we add to a TO in order to get a FROM. They are named
6118 this way because we call this function to find out how to convert from
6119 a pointer to member of FROM to a pointer to member of TO. */
6122 get_delta_difference (tree from, tree to,
6123 bool allow_inverse_p,
6130 /* Assume no conversion is required. */
6131 result = integer_zero_node;
6132 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6133 if (kind == bk_inaccessible || kind == bk_ambig)
6134 error (" in pointer to member function conversion");
6137 if (kind != bk_via_virtual)
6138 result = BINFO_OFFSET (binfo);
6141 tree virt_binfo = binfo_from_vbase (binfo);
6143 /* This is a reinterpret cast, we choose to do nothing. */
6144 if (allow_inverse_p)
6145 warning (0, "pointer to member cast via virtual base %qT",
6146 BINFO_TYPE (virt_binfo));
6148 error ("pointer to member conversion via virtual base %qT",
6149 BINFO_TYPE (virt_binfo));
6152 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
6153 /* Pointer to member of incomplete class is permitted*/;
6154 else if (!allow_inverse_p)
6156 error_not_base_type (from, to);
6157 error (" in pointer to member conversion");
6161 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6164 if (kind != bk_via_virtual)
6165 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6168 /* This is a reinterpret cast, we choose to do nothing. */
6169 tree virt_binfo = binfo_from_vbase (binfo);
6171 warning (0, "pointer to member cast via virtual base %qT",
6172 BINFO_TYPE (virt_binfo));
6177 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6181 /* Return a constructor for the pointer-to-member-function TYPE using
6182 the other components as specified. */
6185 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6190 VEC(constructor_elt, gc) *v;
6192 /* Pull the FIELD_DECLs out of the type. */
6193 pfn_field = TYPE_FIELDS (type);
6194 delta_field = TREE_CHAIN (pfn_field);
6196 /* Make sure DELTA has the type we want. */
6197 delta = convert_and_check (delta_type_node, delta);
6199 /* Finish creating the initializer. */
6200 v = VEC_alloc(constructor_elt, gc, 2);
6201 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6202 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6203 u = build_constructor (type, v);
6204 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6205 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6206 TREE_STATIC (u) = (TREE_CONSTANT (u)
6207 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6209 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6214 /* Build a constructor for a pointer to member function. It can be
6215 used to initialize global variables, local variable, or used
6216 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6219 If FORCE is nonzero, then force this conversion, even if
6220 we would rather not do it. Usually set when using an explicit
6221 cast. A C-style cast is being processed iff C_CAST_P is true.
6223 Return error_mark_node, if something goes wrong. */
6226 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6232 if (error_operand_p (pfn))
6233 return error_mark_node;
6235 pfn_type = TREE_TYPE (pfn);
6236 to_type = build_ptrmemfunc_type (type);
6238 /* Handle multiple conversions of pointer to member functions. */
6239 if (TYPE_PTRMEMFUNC_P (pfn_type))
6241 tree delta = NULL_TREE;
6242 tree npfn = NULL_TREE;
6246 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6247 error ("invalid conversion to type %qT from type %qT",
6250 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6251 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6255 /* We don't have to do any conversion to convert a
6256 pointer-to-member to its own type. But, we don't want to
6257 just return a PTRMEM_CST if there's an explicit cast; that
6258 cast should make the expression an invalid template argument. */
6259 if (TREE_CODE (pfn) != PTRMEM_CST)
6261 if (same_type_p (to_type, pfn_type))
6263 else if (integer_zerop (n))
6264 return build_reinterpret_cast (to_type, pfn);
6267 if (TREE_SIDE_EFFECTS (pfn))
6268 pfn = save_expr (pfn);
6270 /* Obtain the function pointer and the current DELTA. */
6271 if (TREE_CODE (pfn) == PTRMEM_CST)
6272 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6275 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6276 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6279 /* Just adjust the DELTA field. */
6280 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6281 (TREE_TYPE (delta), ptrdiff_type_node));
6282 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6283 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6284 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6285 return build_ptrmemfunc1 (to_type, delta, npfn);
6288 /* Handle null pointer to member function conversions. */
6289 if (integer_zerop (pfn))
6291 pfn = build_c_cast (type, integer_zero_node);
6292 return build_ptrmemfunc1 (to_type,
6297 if (type_unknown_p (pfn))
6298 return instantiate_type (type, pfn, tf_warning_or_error);
6300 fn = TREE_OPERAND (pfn, 0);
6301 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6302 /* In a template, we will have preserved the
6304 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6305 return make_ptrmem_cst (to_type, fn);
6308 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6311 ??? There is no consistency as to the types returned for the above
6312 values. Some code acts as if it were a sizetype and some as if it were
6313 integer_type_node. */
6316 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6318 tree type = TREE_TYPE (cst);
6319 tree fn = PTRMEM_CST_MEMBER (cst);
6320 tree ptr_class, fn_class;
6322 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6324 /* The class that the function belongs to. */
6325 fn_class = DECL_CONTEXT (fn);
6327 /* The class that we're creating a pointer to member of. */
6328 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6330 /* First, calculate the adjustment to the function's class. */
6331 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6334 if (!DECL_VIRTUAL_P (fn))
6335 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6338 /* If we're dealing with a virtual function, we have to adjust 'this'
6339 again, to point to the base which provides the vtable entry for
6340 fn; the call will do the opposite adjustment. */
6341 tree orig_class = DECL_CONTEXT (fn);
6342 tree binfo = binfo_or_else (orig_class, fn_class);
6343 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6344 *delta, BINFO_OFFSET (binfo));
6345 *delta = fold_if_not_in_template (*delta);
6347 /* We set PFN to the vtable offset at which the function can be
6348 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6349 case delta is shifted left, and then incremented). */
6350 *pfn = DECL_VINDEX (fn);
6351 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6352 TYPE_SIZE_UNIT (vtable_entry_type));
6353 *pfn = fold_if_not_in_template (*pfn);
6355 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6357 case ptrmemfunc_vbit_in_pfn:
6358 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6360 *pfn = fold_if_not_in_template (*pfn);
6363 case ptrmemfunc_vbit_in_delta:
6364 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6365 *delta, integer_one_node);
6366 *delta = fold_if_not_in_template (*delta);
6367 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6368 *delta, integer_one_node);
6369 *delta = fold_if_not_in_template (*delta);
6376 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6377 *pfn = fold_if_not_in_template (*pfn);
6381 /* Return an expression for PFN from the pointer-to-member function
6385 pfn_from_ptrmemfunc (tree t)
6387 if (TREE_CODE (t) == PTRMEM_CST)
6392 expand_ptrmemfunc_cst (t, &delta, &pfn);
6397 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6400 /* Convert value RHS to type TYPE as preparation for an assignment to
6401 an lvalue of type TYPE. ERRTYPE is a string to use in error
6402 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6403 are doing the conversion in order to pass the PARMNUMth argument of
6407 convert_for_assignment (tree type, tree rhs,
6408 const char *errtype, tree fndecl, int parmnum)
6411 enum tree_code coder;
6412 /* APPLE LOCAL radar 4874632 */
6413 tree new_rhs = NULL_TREE;
6415 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6416 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6417 rhs = TREE_OPERAND (rhs, 0);
6419 rhstype = TREE_TYPE (rhs);
6420 coder = TREE_CODE (rhstype);
6422 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6423 && vector_types_convertible_p (type, rhstype, true))
6424 return convert (type, rhs);
6426 if (rhs == error_mark_node || rhstype == error_mark_node)
6427 return error_mark_node;
6428 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6429 return error_mark_node;
6431 /* The RHS of an assignment cannot have void type. */
6432 if (coder == VOID_TYPE)
6434 error ("void value not ignored as it ought to be");
6435 return error_mark_node;
6438 /* Simplify the RHS if possible. */
6439 if (TREE_CODE (rhs) == CONST_DECL)
6440 rhs = DECL_INITIAL (rhs);
6442 if (c_dialect_objc ())
6445 tree rname = fndecl;
6447 if (!strcmp (errtype, "assignment"))
6449 else if (!strcmp (errtype, "initialization"))
6453 tree selector = objc_message_selector ();
6457 if (selector && parmno > 1)
6464 /* APPLE LOCAL file radar 6231433 */
6465 if (objc_compare_types (type, rhstype, parmno, rname, "comparison"))
6466 /* APPLE LOCAL radar 4874632 */
6467 new_rhs = convert (type, rhs);
6472 The expression is implicitly converted (clause _conv_) to the
6473 cv-unqualified type of the left operand.
6475 We allow bad conversions here because by the time we get to this point
6476 we are committed to doing the conversion. If we end up doing a bad
6477 conversion, convert_like will complain. */
6478 if (!can_convert_arg_bad (type, rhstype, rhs))
6480 /* When -Wno-pmf-conversions is use, we just silently allow
6481 conversions from pointers-to-members to plain pointers. If
6482 the conversion doesn't work, cp_convert will complain. */
6484 && TYPE_PTR_P (type)
6485 && TYPE_PTRMEMFUNC_P (rhstype))
6486 rhs = cp_convert (strip_top_quals (type), rhs);
6489 /* If the right-hand side has unknown type, then it is an
6490 overloaded function. Call instantiate_type to get error
6492 if (rhstype == unknown_type_node)
6493 instantiate_type (type, rhs, tf_warning_or_error);
6495 error ("cannot convert %qT to %qT for argument %qP to %qD",
6496 rhstype, type, parmnum, fndecl);
6498 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6499 return error_mark_node;
6502 if (warn_missing_format_attribute)
6504 const enum tree_code codel = TREE_CODE (type);
6505 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6507 && check_missing_format_attribute (type, rhstype))
6508 warning (OPT_Wmissing_format_attribute,
6509 "%s might be a candidate for a format attribute",
6513 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6515 if (warn_parentheses
6516 && type == boolean_type_node
6517 && TREE_CODE (rhs) == MODIFY_EXPR
6518 && !TREE_NO_WARNING (rhs)
6519 && TREE_TYPE (rhs) != boolean_type_node)
6521 warning (OPT_Wparentheses,
6522 "suggest parentheses around assignment used as truth value");
6523 TREE_NO_WARNING (rhs) = 1;
6526 return perform_implicit_conversion (strip_top_quals (type), rhs);
6529 /* Convert RHS to be of type TYPE.
6530 If EXP is nonzero, it is the target of the initialization.
6531 ERRTYPE is a string to use in error messages.
6533 Two major differences between the behavior of
6534 `convert_for_assignment' and `convert_for_initialization'
6535 are that references are bashed in the former, while
6536 copied in the latter, and aggregates are assigned in
6537 the former (operator=) while initialized in the
6540 If using constructor make sure no conversion operator exists, if one does
6541 exist, an ambiguity exists.
6543 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6546 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6547 const char *errtype, tree fndecl, int parmnum)
6549 enum tree_code codel = TREE_CODE (type);
6551 enum tree_code coder;
6553 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6554 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6555 if (TREE_CODE (rhs) == NOP_EXPR
6556 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6557 && codel != REFERENCE_TYPE)
6558 rhs = TREE_OPERAND (rhs, 0);
6560 if (type == error_mark_node
6561 || rhs == error_mark_node
6562 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6563 return error_mark_node;
6565 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6566 && TREE_CODE (type) != ARRAY_TYPE
6567 && (TREE_CODE (type) != REFERENCE_TYPE
6568 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6569 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6570 && (TREE_CODE (type) != REFERENCE_TYPE
6571 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6572 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6573 rhs = decay_conversion (rhs);
6575 rhstype = TREE_TYPE (rhs);
6576 coder = TREE_CODE (rhstype);
6578 if (coder == ERROR_MARK)
6579 return error_mark_node;
6581 /* We accept references to incomplete types, so we can
6582 return here before checking if RHS is of complete type. */
6584 if (codel == REFERENCE_TYPE)
6586 /* This should eventually happen in convert_arguments. */
6587 int savew = 0, savee = 0;
6590 savew = warningcount, savee = errorcount;
6591 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6595 if (warningcount > savew)
6596 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6597 else if (errorcount > savee)
6598 error ("in passing argument %P of %q+D", parmnum, fndecl);
6604 exp = require_complete_type (exp);
6605 if (exp == error_mark_node)
6606 return error_mark_node;
6608 rhstype = non_reference (rhstype);
6610 type = complete_type (type);
6612 if (IS_AGGR_TYPE (type))
6613 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6615 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6618 /* If RETVAL is the address of, or a reference to, a local variable or
6619 temporary give an appropriate warning. */
6622 maybe_warn_about_returning_address_of_local (tree retval)
6624 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6625 tree whats_returned = retval;
6629 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6630 whats_returned = TREE_OPERAND (whats_returned, 1);
6631 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6632 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6633 || TREE_CODE (whats_returned) == NOP_EXPR)
6634 whats_returned = TREE_OPERAND (whats_returned, 0);
6639 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6641 whats_returned = TREE_OPERAND (whats_returned, 0);
6643 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6645 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6646 || TREE_CODE (whats_returned) == TARGET_EXPR)
6648 warning (0, "returning reference to temporary");
6651 if (TREE_CODE (whats_returned) == VAR_DECL
6652 && DECL_NAME (whats_returned)
6653 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6655 warning (0, "reference to non-lvalue returned");
6660 while (TREE_CODE (whats_returned) == COMPONENT_REF
6661 || TREE_CODE (whats_returned) == ARRAY_REF)
6662 whats_returned = TREE_OPERAND (whats_returned, 0);
6664 if (DECL_P (whats_returned)
6665 && DECL_NAME (whats_returned)
6666 && DECL_FUNCTION_SCOPE_P (whats_returned)
6667 && !(TREE_STATIC (whats_returned)
6668 || TREE_PUBLIC (whats_returned)))
6670 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6671 warning (0, "reference to local variable %q+D returned",
6673 /* APPLE LOCAL begin blocks 6040305 (cn) */
6674 else if (TREE_CODE (valtype) == BLOCK_POINTER_TYPE)
6675 error ("returning block that lives on the local stack");
6676 /* APPLE LOCAL end blocks 6040305 (cn) */
6678 warning (0, "address of local variable %q+D returned",
6684 /* APPLE LOCAL begin blocks 6040305 (cm) */
6686 types_are_block_compatible (tree t1, tree t2)
6688 return comptypes (t1, t2, COMPARE_STRICT);
6690 /* APPLE LOCAL end blocks 6040305 (cm) */
6692 /* Check that returning RETVAL from the current function is valid.
6693 Return an expression explicitly showing all conversions required to
6694 change RETVAL into the function return type, and to assign it to
6695 the DECL_RESULT for the function. Set *NO_WARNING to true if
6696 code reaches end of non-void function warning shouldn't be issued
6697 on this RETURN_EXPR. */
6700 check_return_expr (tree retval, bool *no_warning)
6703 /* The type actually returned by the function, after any
6706 int fn_returns_value_p;
6708 *no_warning = false;
6710 /* A `volatile' function is one that isn't supposed to return, ever.
6711 (This is a G++ extension, used to get better code for functions
6712 that call the `volatile' function.) */
6713 if (TREE_THIS_VOLATILE (current_function_decl))
6714 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6716 /* Check for various simple errors. */
6717 if (DECL_DESTRUCTOR_P (current_function_decl))
6720 error ("returning a value from a destructor");
6723 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6725 if (in_function_try_handler)
6726 /* If a return statement appears in a handler of the
6727 function-try-block of a constructor, the program is ill-formed. */
6728 error ("cannot return from a handler of a function-try-block of a constructor");
6730 /* You can't return a value from a constructor. */
6731 error ("returning a value from a constructor");
6735 /* APPLE LOCAL begin blocks 6040305 (cm) */
6736 /* APPLE LOCAL radar 6185344 */
6737 if (cur_block && !cur_block->block_has_return_type)
6739 /* If this is the first return we've seen in the block, infer the type of
6740 the block from it. */
6741 if (cur_block->return_type == NULL_TREE)
6746 retval = decay_conversion (retval);
6747 restype = TYPE_MAIN_VARIANT (TREE_TYPE (retval));
6748 TREE_TYPE (current_function_decl)
6749 = build_function_type (restype,
6750 TYPE_ARG_TYPES (TREE_TYPE (current_function_decl)));
6751 TREE_TYPE (DECL_RESULT (current_function_decl)) = restype;
6752 relayout_decl (DECL_RESULT (current_function_decl));
6753 cur_block->return_type = restype;
6756 cur_block->return_type = void_type_node;
6759 /* Verify that this result type matches the previous one. We
6760 are pickier with blocks than for normal functions because
6761 this is a new feature and we set the rules. */
6762 if (TREE_CODE (cur_block->return_type) == VOID_TYPE)
6766 error ("void block should not return a value");
6767 return error_mark_node;
6772 error ("non-void block should return a value");
6773 return error_mark_node;
6778 /* We have a non-void block with an expression, continue checking. */
6779 valtype = TREE_TYPE (retval);
6781 /* For now, restrict multiple return statements in a block to have
6782 strict compatible types only. */
6783 if (!types_are_block_compatible (cur_block->return_type, valtype))
6785 error ("incompatible type returning %qT, expected %qT",
6786 valtype, cur_block->return_type);
6787 return error_mark_node;
6791 /* APPLE LOCAL end blocks 6040305 (cm) */
6793 if (processing_template_decl)
6795 current_function_returns_value = 1;
6799 /* When no explicit return-value is given in a function with a named
6800 return value, the named return value is used. */
6801 result = DECL_RESULT (current_function_decl);
6802 valtype = TREE_TYPE (result);
6803 gcc_assert (valtype != NULL_TREE);
6804 fn_returns_value_p = !VOID_TYPE_P (valtype);
6805 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6808 /* Check for a return statement with no return value in a function
6809 that's supposed to return a value. */
6810 if (!retval && fn_returns_value_p)
6812 pedwarn ("return-statement with no value, in function returning %qT",
6814 /* Clear this, so finish_function won't say that we reach the
6815 end of a non-void function (which we don't, we gave a
6817 current_function_returns_null = 0;
6818 /* And signal caller that TREE_NO_WARNING should be set on the
6819 RETURN_EXPR to avoid control reaches end of non-void function
6820 warnings in tree-cfg.c. */
6823 /* Check for a return statement with a value in a function that
6824 isn't supposed to return a value. */
6825 else if (retval && !fn_returns_value_p)
6827 if (VOID_TYPE_P (TREE_TYPE (retval)))
6828 /* You can return a `void' value from a function of `void'
6829 type. In that case, we have to evaluate the expression for
6830 its side-effects. */
6831 finish_expr_stmt (retval);
6833 pedwarn ("return-statement with a value, in function "
6834 "returning 'void'");
6836 current_function_returns_null = 1;
6838 /* There's really no value to return, after all. */
6842 /* Remember that this function can sometimes return without a
6844 current_function_returns_null = 1;
6846 /* Remember that this function did return a value. */
6847 current_function_returns_value = 1;
6849 /* Check for erroneous operands -- but after giving ourselves a
6850 chance to provide an error about returning a value from a void
6852 if (error_operand_p (retval))
6854 current_function_return_value = error_mark_node;
6855 return error_mark_node;
6858 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6859 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6860 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6861 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6863 && null_ptr_cst_p (retval))
6864 warning (0, "%<operator new%> must not return NULL unless it is "
6865 "declared %<throw()%> (or -fcheck-new is in effect)");
6867 /* Effective C++ rule 15. See also start_function. */
6869 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6873 /* The function return type must be a reference to the current
6875 if (TREE_CODE (valtype) == REFERENCE_TYPE
6876 && same_type_ignoring_top_level_qualifiers_p
6877 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6879 /* Returning '*this' is obviously OK. */
6880 if (retval == current_class_ref)
6882 /* If we are calling a function whose return type is the same of
6883 the current class reference, it is ok. */
6884 else if (TREE_CODE (retval) == INDIRECT_REF
6885 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6890 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6893 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6895 [...] For a function with a class return type, if the expression
6896 in the return statement is the name of a local object, and the cv-
6897 unqualified type of the local object is the same as the function
6898 return type, an implementation is permitted to omit creating the tem-
6899 porary object to hold the function return value [...]
6901 So, if this is a value-returning function that always returns the same
6902 local variable, remember it.
6904 It might be nice to be more flexible, and choose the first suitable
6905 variable even if the function sometimes returns something else, but
6906 then we run the risk of clobbering the variable we chose if the other
6907 returned expression uses the chosen variable somehow. And people expect
6908 this restriction, anyway. (jason 2000-11-19)
6910 See finish_function and finalize_nrv for the rest of this optimization. */
6912 if (fn_returns_value_p && flag_elide_constructors)
6914 if (retval != NULL_TREE
6915 && (current_function_return_value == NULL_TREE
6916 || current_function_return_value == retval)
6917 && TREE_CODE (retval) == VAR_DECL
6918 && DECL_CONTEXT (retval) == current_function_decl
6919 && ! TREE_STATIC (retval)
6920 && ! DECL_ANON_UNION_VAR_P (retval)
6921 && (DECL_ALIGN (retval)
6922 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6923 && same_type_p ((TYPE_MAIN_VARIANT
6924 (TREE_TYPE (retval))),
6926 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6927 current_function_return_value = retval;
6929 current_function_return_value = error_mark_node;
6932 /* We don't need to do any conversions when there's nothing being
6937 /* Do any required conversions. */
6938 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6939 /* No conversions are required. */
6943 /* The type the function is declared to return. */
6944 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6946 /* The functype's return type will have been set to void, if it
6947 was an incomplete type. Just treat this as 'return;' */
6948 if (VOID_TYPE_P (functype))
6949 return error_mark_node;
6951 /* First convert the value to the function's return type, then
6952 to the type of return value's location to handle the
6953 case that functype is smaller than the valtype. */
6954 retval = convert_for_initialization
6955 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6956 "return", NULL_TREE, 0);
6957 retval = convert (valtype, retval);
6959 /* If the conversion failed, treat this just like `return;'. */
6960 if (retval == error_mark_node)
6962 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6963 else if (! current_function_returns_struct
6964 && TREE_CODE (retval) == TARGET_EXPR
6965 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6966 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6967 TREE_OPERAND (retval, 0));
6969 maybe_warn_about_returning_address_of_local (retval);
6972 /* Actually copy the value returned into the appropriate location. */
6973 if (retval && retval != result)
6974 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6980 /* Returns nonzero if the pointer-type FROM can be converted to the
6981 pointer-type TO via a qualification conversion. If CONSTP is -1,
6982 then we return nonzero if the pointers are similar, and the
6983 cv-qualification signature of FROM is a proper subset of that of TO.
6985 If CONSTP is positive, then all outer pointers have been
6989 comp_ptr_ttypes_real (tree to, tree from, int constp)
6991 bool to_more_cv_qualified = false;
6993 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6995 if (TREE_CODE (to) != TREE_CODE (from))
6998 if (TREE_CODE (from) == OFFSET_TYPE
6999 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
7000 TYPE_OFFSET_BASETYPE (to)))
7003 /* Const and volatile mean something different for function types,
7004 so the usual checks are not appropriate. */
7005 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
7007 /* In Objective-C++, some types may have been 'volatilized' by
7008 the compiler for EH; when comparing them here, the volatile
7009 qualification must be ignored. */
7010 bool objc_quals_match = objc_type_quals_match (to, from);
7012 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
7015 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
7019 to_more_cv_qualified = true;
7023 constp &= TYPE_READONLY (to);
7026 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
7027 return ((constp >= 0 || to_more_cv_qualified)
7028 && same_type_ignoring_top_level_qualifiers_p (to, from));
7032 /* When comparing, say, char ** to char const **, this function takes
7033 the 'char *' and 'char const *'. Do not pass non-pointer/reference
7034 types to this function. */
7037 comp_ptr_ttypes (tree to, tree from)
7039 return comp_ptr_ttypes_real (to, from, 1);
7042 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
7043 type or inheritance-related types, regardless of cv-quals. */
7046 ptr_reasonably_similar (tree to, tree from)
7048 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7050 /* Any target type is similar enough to void. */
7051 if (TREE_CODE (to) == VOID_TYPE
7052 || TREE_CODE (from) == VOID_TYPE)
7055 if (TREE_CODE (to) != TREE_CODE (from))
7058 if (TREE_CODE (from) == OFFSET_TYPE
7059 && comptypes (TYPE_OFFSET_BASETYPE (to),
7060 TYPE_OFFSET_BASETYPE (from),
7061 COMPARE_BASE | COMPARE_DERIVED))
7064 if (TREE_CODE (to) == VECTOR_TYPE
7065 && vector_types_convertible_p (to, from, false))
7068 if (TREE_CODE (to) == INTEGER_TYPE
7069 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
7072 if (TREE_CODE (to) == FUNCTION_TYPE)
7075 if (TREE_CODE (to) != POINTER_TYPE)
7077 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
7078 COMPARE_BASE | COMPARE_DERIVED);
7082 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
7083 pointer-to-member types) are the same, ignoring cv-qualification at
7087 comp_ptr_ttypes_const (tree to, tree from)
7089 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7091 if (TREE_CODE (to) != TREE_CODE (from))
7094 if (TREE_CODE (from) == OFFSET_TYPE
7095 && same_type_p (TYPE_OFFSET_BASETYPE (from),
7096 TYPE_OFFSET_BASETYPE (to)))
7099 if (TREE_CODE (to) != POINTER_TYPE)
7100 return same_type_ignoring_top_level_qualifiers_p (to, from);
7104 /* Returns the type qualifiers for this type, including the qualifiers on the
7105 elements for an array type. */
7108 cp_type_quals (tree type)
7110 type = strip_array_types (type);
7111 if (type == error_mark_node)
7112 return TYPE_UNQUALIFIED;
7113 return TYPE_QUALS (type);
7116 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
7120 cp_type_readonly (tree type)
7122 type = strip_array_types (type);
7123 return TYPE_READONLY (type);
7126 /* Returns nonzero if the TYPE contains a mutable member. */
7129 cp_has_mutable_p (tree type)
7131 type = strip_array_types (type);
7133 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
7136 /* Apply the TYPE_QUALS to the new DECL. */
7138 cp_apply_type_quals_to_decl (int type_quals, tree decl)
7140 tree type = TREE_TYPE (decl);
7142 if (type == error_mark_node)
7145 if (TREE_CODE (type) == FUNCTION_TYPE
7146 && type_quals != TYPE_UNQUALIFIED)
7148 /* This was an error in C++98 (cv-qualifiers cannot be added to
7149 a function type), but DR 295 makes the code well-formed by
7150 dropping the extra qualifiers. */
7153 tree bad_type = build_qualified_type (type, type_quals);
7154 pedwarn ("ignoring %qV qualifiers added to function type %qT",
7158 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
7162 /* Avoid setting TREE_READONLY incorrectly. */
7163 if (/* If the object has a constructor, the constructor may modify
7165 TYPE_NEEDS_CONSTRUCTING (type)
7166 /* If the type isn't complete, we don't know yet if it will need
7168 || !COMPLETE_TYPE_P (type)
7169 /* If the type has a mutable component, that component might be
7171 || TYPE_HAS_MUTABLE_P (type))
7172 type_quals &= ~TYPE_QUAL_CONST;
7174 c_apply_type_quals_to_decl (type_quals, decl);
7177 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7178 exemplar types such that casting T1 to T2 is casting away constness
7179 if and only if there is no implicit conversion from T1 to T2. */
7182 casts_away_constness_r (tree *t1, tree *t2)
7187 /* [expr.const.cast]
7189 For multi-level pointer to members and multi-level mixed pointers
7190 and pointers to members (conv.qual), the "member" aspect of a
7191 pointer to member level is ignored when determining if a const
7192 cv-qualifier has been cast away. */
7193 /* [expr.const.cast]
7195 For two pointer types:
7197 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7198 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7201 casting from X1 to X2 casts away constness if, for a non-pointer
7202 type T there does not exist an implicit conversion (clause
7205 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7209 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7210 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7211 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7213 *t1 = cp_build_qualified_type (void_type_node,
7214 cp_type_quals (*t1));
7215 *t2 = cp_build_qualified_type (void_type_node,
7216 cp_type_quals (*t2));
7220 quals1 = cp_type_quals (*t1);
7221 quals2 = cp_type_quals (*t2);
7223 if (TYPE_PTRMEM_P (*t1))
7224 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7226 *t1 = TREE_TYPE (*t1);
7227 if (TYPE_PTRMEM_P (*t2))
7228 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7230 *t2 = TREE_TYPE (*t2);
7232 casts_away_constness_r (t1, t2);
7233 *t1 = build_pointer_type (*t1);
7234 *t2 = build_pointer_type (*t2);
7235 *t1 = cp_build_qualified_type (*t1, quals1);
7236 *t2 = cp_build_qualified_type (*t2, quals2);
7239 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7243 casts_away_constness (tree t1, tree t2)
7245 if (TREE_CODE (t2) == REFERENCE_TYPE)
7247 /* [expr.const.cast]
7249 Casting from an lvalue of type T1 to an lvalue of type T2
7250 using a reference cast casts away constness if a cast from an
7251 rvalue of type "pointer to T1" to the type "pointer to T2"
7252 casts away constness. */
7253 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7254 return casts_away_constness (build_pointer_type (t1),
7255 build_pointer_type (TREE_TYPE (t2)));
7258 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7259 /* [expr.const.cast]
7261 Casting from an rvalue of type "pointer to data member of X
7262 of type T1" to the type "pointer to data member of Y of type
7263 T2" casts away constness if a cast from an rvalue of type
7264 "pointer to T1" to the type "pointer to T2" casts away
7266 return casts_away_constness
7267 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7268 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7270 /* Casting away constness is only something that makes sense for
7271 pointer or reference types. */
7272 if (TREE_CODE (t1) != POINTER_TYPE
7273 || TREE_CODE (t2) != POINTER_TYPE)
7276 /* Top-level qualifiers don't matter. */
7277 t1 = TYPE_MAIN_VARIANT (t1);
7278 t2 = TYPE_MAIN_VARIANT (t2);
7279 casts_away_constness_r (&t1, &t2);
7280 if (!can_convert (t2, t1))
7286 /* If T is a REFERENCE_TYPE return the type to which T refers.
7287 Otherwise, return T itself. */
7290 non_reference (tree t)
7292 if (TREE_CODE (t) == REFERENCE_TYPE)
7298 /* Return nonzero if REF is an lvalue valid for this language;
7299 otherwise, print an error message and return zero. USE says
7300 how the lvalue is being used and so selects the error message. */
7303 lvalue_or_else (tree ref, enum lvalue_use use)
7305 int win = lvalue_p (ref);