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, 2006, 2007, 2008
4 Free Software Foundation, Inc.
5 Hacked by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
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"
48 static tree pfn_from_ptrmemfunc (tree);
49 static tree delta_from_ptrmemfunc (tree);
50 static tree convert_for_assignment (tree, tree, const char *, tree, int,
52 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
53 static tree rationalize_conditional_expr (enum tree_code, tree,
55 static int comp_ptr_ttypes_real (tree, tree, int);
56 static bool comp_except_types (tree, tree, bool);
57 static bool comp_array_types (const_tree, const_tree, bool);
58 static tree pointer_diff (tree, tree, tree);
59 static tree get_delta_difference (tree, tree, bool, bool);
60 static void casts_away_constness_r (tree *, tree *);
61 static bool casts_away_constness (tree, tree);
62 static void maybe_warn_about_returning_address_of_local (tree);
63 static tree lookup_destructor (tree, tree, tree);
64 static int convert_arguments (int, tree *, tree, tree, tree, int,
67 /* Do `exp = require_complete_type (exp);' to make sure exp
68 does not have an incomplete type. (That includes void types.)
69 Returns the error_mark_node if the VALUE does not have
70 complete type when this function returns. */
73 require_complete_type (tree value)
77 if (processing_template_decl || value == error_mark_node)
80 if (TREE_CODE (value) == OVERLOAD)
81 type = unknown_type_node;
83 type = TREE_TYPE (value);
85 if (type == error_mark_node)
86 return error_mark_node;
88 /* First, detect a valid value with a complete type. */
89 if (COMPLETE_TYPE_P (type))
92 if (complete_type_or_else (type, value))
95 return error_mark_node;
98 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
99 a template instantiation, do the instantiation. Returns TYPE,
100 whether or not it could be completed, unless something goes
101 horribly wrong, in which case the error_mark_node is returned. */
104 complete_type (tree type)
106 if (type == NULL_TREE)
107 /* Rather than crash, we return something sure to cause an error
109 return error_mark_node;
111 if (type == error_mark_node || COMPLETE_TYPE_P (type))
113 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
115 tree t = complete_type (TREE_TYPE (type));
116 unsigned int needs_constructing, has_nontrivial_dtor;
117 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
120 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
122 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
123 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
125 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
126 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
129 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
130 instantiate_class_template (TYPE_MAIN_VARIANT (type));
135 /* Like complete_type, but issue an error if the TYPE cannot be completed.
136 VALUE is used for informative diagnostics.
137 Returns NULL_TREE if the type cannot be made complete. */
140 complete_type_or_else (tree type, tree value)
142 type = complete_type (type);
143 if (type == error_mark_node)
144 /* We already issued an error. */
146 else if (!COMPLETE_TYPE_P (type))
148 cxx_incomplete_type_diagnostic (value, type, 0);
155 /* Return truthvalue of whether type of EXP is instantiated. */
158 type_unknown_p (const_tree exp)
160 return (TREE_CODE (exp) == TREE_LIST
161 || TREE_TYPE (exp) == unknown_type_node);
165 /* Return the common type of two parameter lists.
166 We assume that comptypes has already been done and returned 1;
167 if that isn't so, this may crash.
169 As an optimization, free the space we allocate if the parameter
170 lists are already common. */
173 commonparms (tree p1, tree p2)
175 tree oldargs = p1, newargs, n;
179 len = list_length (p1);
180 newargs = tree_last (p1);
182 if (newargs == void_list_node)
191 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
196 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
198 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
200 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
203 else if (! TREE_PURPOSE (p1))
205 if (TREE_PURPOSE (p2))
207 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
213 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
215 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
217 if (TREE_VALUE (p1) != TREE_VALUE (p2))
220 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
223 TREE_VALUE (n) = TREE_VALUE (p1);
231 /* Given a type, perhaps copied for a typedef,
232 find the "original" version of it. */
234 original_type (tree t)
236 int quals = cp_type_quals (t);
237 while (t != error_mark_node
238 && TYPE_NAME (t) != NULL_TREE)
240 tree x = TYPE_NAME (t);
241 if (TREE_CODE (x) != TYPE_DECL)
243 x = DECL_ORIGINAL_TYPE (x);
248 return cp_build_qualified_type (t, quals);
251 /* T1 and T2 are arithmetic or enumeration types. Return the type
252 that will result from the "usual arithmetic conversions" on T1 and
253 T2 as described in [expr]. */
256 type_after_usual_arithmetic_conversions (tree t1, tree t2)
258 enum tree_code code1 = TREE_CODE (t1);
259 enum tree_code code2 = TREE_CODE (t2);
262 /* FIXME: Attributes. */
263 gcc_assert (ARITHMETIC_TYPE_P (t1)
264 || TREE_CODE (t1) == VECTOR_TYPE
265 || TREE_CODE (t1) == ENUMERAL_TYPE);
266 gcc_assert (ARITHMETIC_TYPE_P (t2)
267 || TREE_CODE (t2) == VECTOR_TYPE
268 || TREE_CODE (t2) == ENUMERAL_TYPE);
270 /* In what follows, we slightly generalize the rules given in [expr] so
271 as to deal with `long long' and `complex'. First, merge the
273 attributes = (*targetm.merge_type_attributes) (t1, t2);
275 /* If one type is complex, form the common type of the non-complex
276 components, then make that complex. Use T1 or T2 if it is the
278 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
280 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
281 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
283 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
285 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
286 return build_type_attribute_variant (t1, attributes);
287 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
288 return build_type_attribute_variant (t2, attributes);
290 return build_type_attribute_variant (build_complex_type (subtype),
294 if (code1 == VECTOR_TYPE)
296 /* When we get here we should have two vectors of the same size.
297 Just prefer the unsigned one if present. */
298 if (TYPE_UNSIGNED (t1))
299 return build_type_attribute_variant (t1, attributes);
301 return build_type_attribute_variant (t2, attributes);
304 /* If only one is real, use it as the result. */
305 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
306 return build_type_attribute_variant (t1, attributes);
307 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
308 return build_type_attribute_variant (t2, attributes);
310 /* Perform the integral promotions. */
311 if (code1 != REAL_TYPE)
313 t1 = type_promotes_to (t1);
314 t2 = type_promotes_to (t2);
317 /* Both real or both integers; use the one with greater precision. */
318 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
319 return build_type_attribute_variant (t1, attributes);
320 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
321 return build_type_attribute_variant (t2, attributes);
323 /* The types are the same; no need to do anything fancy. */
324 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
325 return build_type_attribute_variant (t1, attributes);
327 if (code1 != REAL_TYPE)
329 /* If one is unsigned long long, then convert the other to unsigned
331 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
332 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
333 return build_type_attribute_variant (long_long_unsigned_type_node,
335 /* If one is a long long, and the other is an unsigned long, and
336 long long can represent all the values of an unsigned long, then
337 convert to a long long. Otherwise, convert to an unsigned long
338 long. Otherwise, if either operand is long long, convert the
341 Since we're here, we know the TYPE_PRECISION is the same;
342 therefore converting to long long cannot represent all the values
343 of an unsigned long, so we choose unsigned long long in that
345 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
346 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
349 ? long_long_unsigned_type_node
350 : long_long_integer_type_node);
351 return build_type_attribute_variant (t, attributes);
354 /* Go through the same procedure, but for longs. */
355 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
356 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
357 return build_type_attribute_variant (long_unsigned_type_node,
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
363 ? long_unsigned_type_node : long_integer_type_node);
364 return build_type_attribute_variant (t, attributes);
366 /* Otherwise prefer the unsigned one. */
367 if (TYPE_UNSIGNED (t1))
368 return build_type_attribute_variant (t1, attributes);
370 return build_type_attribute_variant (t2, attributes);
374 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
375 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
376 return build_type_attribute_variant (long_double_type_node,
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
380 return build_type_attribute_variant (double_type_node,
382 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
383 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
384 return build_type_attribute_variant (float_type_node,
387 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
388 the standard C++ floating-point types. Logic earlier in this
389 function has already eliminated the possibility that
390 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
391 compelling reason to choose one or the other. */
392 return build_type_attribute_variant (t1, attributes);
396 /* Subroutine of composite_pointer_type to implement the recursive
397 case. See that function for documentation fo the parameters. */
400 composite_pointer_type_r (tree t1, tree t2, const char* location,
401 tsubst_flags_t complain)
408 /* Determine the types pointed to by T1 and T2. */
409 if (TREE_CODE (t1) == POINTER_TYPE)
411 pointee1 = TREE_TYPE (t1);
412 pointee2 = TREE_TYPE (t2);
416 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
417 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
422 Otherwise, the composite pointer type is a pointer type
423 similar (_conv.qual_) to the type of one of the operands,
424 with a cv-qualification signature (_conv.qual_) that is the
425 union of the cv-qualification signatures of the operand
427 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
428 result_type = pointee1;
429 else if ((TREE_CODE (pointee1) == POINTER_TYPE
430 && TREE_CODE (pointee2) == POINTER_TYPE)
431 || (TYPE_PTR_TO_MEMBER_P (pointee1)
432 && TYPE_PTR_TO_MEMBER_P (pointee2)))
433 result_type = composite_pointer_type_r (pointee1, pointee2, location,
437 if (complain & tf_error)
438 permerror ("%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 && (complain & tf_error))
453 permerror ("%s between distinct pointer types %qT and %qT "
456 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
460 result_type = build_pointer_type (result_type);
462 /* Merge the attributes. */
463 attributes = (*targetm.merge_type_attributes) (t1, t2);
464 return build_type_attribute_variant (result_type, attributes);
467 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
468 ARG1 and ARG2 are the values with those types. The LOCATION is a
469 string describing the current location, in case an error occurs.
471 This routine also implements the computation of a common type for
472 pointers-to-members as per [expr.eq]. */
475 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
476 const char* location, tsubst_flags_t complain)
483 If one operand is a null pointer constant, the composite pointer
484 type is the type of the other operand. */
485 if (null_ptr_cst_p (arg1))
487 if (null_ptr_cst_p (arg2))
494 If one of the operands has type "pointer to cv1 void*", then
495 the other has type "pointer to cv2T", and the composite pointer
496 type is "pointer to cv12 void", where cv12 is the union of cv1
499 If either type is a pointer to void, make sure it is T1. */
500 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
508 /* Now, if T1 is a pointer to void, merge the qualifiers. */
509 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
514 if (pedantic && TYPE_PTRFN_P (t2) && (complain & tf_error))
515 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
516 "and pointer-to-function", location);
518 = cp_build_qualified_type (void_type_node,
519 (cp_type_quals (TREE_TYPE (t1))
520 | cp_type_quals (TREE_TYPE (t2))));
521 result_type = build_pointer_type (result_type);
522 /* Merge the attributes. */
523 attributes = (*targetm.merge_type_attributes) (t1, t2);
524 return build_type_attribute_variant (result_type, attributes);
527 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
528 && TREE_CODE (t2) == POINTER_TYPE)
530 if (objc_compare_types (t1, t2, -3, NULL_TREE))
534 /* [expr.eq] permits the application of a pointer conversion to
535 bring the pointers to a common type. */
536 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
537 && CLASS_TYPE_P (TREE_TYPE (t1))
538 && CLASS_TYPE_P (TREE_TYPE (t2))
539 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
542 class1 = TREE_TYPE (t1);
543 class2 = TREE_TYPE (t2);
545 if (DERIVED_FROM_P (class1, class2))
546 t2 = (build_pointer_type
547 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
548 else if (DERIVED_FROM_P (class2, class1))
549 t1 = (build_pointer_type
550 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
553 if (complain & tf_error)
554 error ("%s between distinct pointer types %qT and %qT "
555 "lacks a cast", location, t1, t2);
556 return error_mark_node;
559 /* [expr.eq] permits the application of a pointer-to-member
560 conversion to change the class type of one of the types. */
561 else if (TYPE_PTR_TO_MEMBER_P (t1)
562 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
563 TYPE_PTRMEM_CLASS_TYPE (t2)))
565 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
566 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
568 if (DERIVED_FROM_P (class1, class2))
569 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
570 else if (DERIVED_FROM_P (class2, class1))
571 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
574 if (complain & tf_error)
575 error ("%s between distinct pointer-to-member types %qT and %qT "
576 "lacks a cast", location, t1, t2);
577 return error_mark_node;
581 return composite_pointer_type_r (t1, t2, location, complain);
584 /* Return the merged type of two types.
585 We assume that comptypes has already been done and returned 1;
586 if that isn't so, this may crash.
588 This just combines attributes and default arguments; any other
589 differences would cause the two types to compare unalike. */
592 merge_types (tree t1, tree t2)
594 enum tree_code code1;
595 enum tree_code code2;
598 /* Save time if the two types are the same. */
601 if (original_type (t1) == original_type (t2))
604 /* If one type is nonsense, use the other. */
605 if (t1 == error_mark_node)
607 if (t2 == error_mark_node)
610 /* Merge the attributes. */
611 attributes = (*targetm.merge_type_attributes) (t1, t2);
613 if (TYPE_PTRMEMFUNC_P (t1))
614 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
615 if (TYPE_PTRMEMFUNC_P (t2))
616 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
618 code1 = TREE_CODE (t1);
619 code2 = TREE_CODE (t2);
625 /* For two pointers, do this recursively on the target type. */
627 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
628 int quals = cp_type_quals (t1);
630 if (code1 == POINTER_TYPE)
631 t1 = build_pointer_type (target);
633 t1 = cp_build_reference_type (target, TYPE_REF_IS_RVALUE (t1));
634 t1 = build_type_attribute_variant (t1, attributes);
635 t1 = cp_build_qualified_type (t1, quals);
637 if (TREE_CODE (target) == METHOD_TYPE)
638 t1 = build_ptrmemfunc_type (t1);
647 quals = cp_type_quals (t1);
648 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
649 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
650 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
652 t1 = cp_build_qualified_type (t1, quals);
658 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
659 /* Save space: see if the result is identical to one of the args. */
660 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
661 return build_type_attribute_variant (t1, attributes);
662 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
663 return build_type_attribute_variant (t2, attributes);
664 /* Merge the element types, and have a size if either arg has one. */
665 t1 = build_cplus_array_type
666 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
671 /* Function types: prefer the one that specified arg types.
672 If both do, merge the arg types. Also merge the return types. */
674 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
675 tree p1 = TYPE_ARG_TYPES (t1);
676 tree p2 = TYPE_ARG_TYPES (t2);
679 /* Save space: see if the result is identical to one of the args. */
680 if (valtype == TREE_TYPE (t1) && ! p2)
681 return cp_build_type_attribute_variant (t1, attributes);
682 if (valtype == TREE_TYPE (t2) && ! p1)
683 return cp_build_type_attribute_variant (t2, attributes);
685 /* Simple way if one arg fails to specify argument types. */
686 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
688 rval = build_function_type (valtype, p2);
689 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
690 rval = build_exception_variant (rval, raises);
691 return cp_build_type_attribute_variant (rval, attributes);
693 raises = TYPE_RAISES_EXCEPTIONS (t1);
694 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
696 rval = build_function_type (valtype, p1);
698 rval = build_exception_variant (rval, raises);
699 return cp_build_type_attribute_variant (rval, attributes);
702 rval = build_function_type (valtype, commonparms (p1, p2));
703 t1 = build_exception_variant (rval, raises);
709 /* Get this value the long way, since TYPE_METHOD_BASETYPE
710 is just the main variant of this. */
711 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
712 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
715 /* If this was a member function type, get back to the
716 original type of type member function (i.e., without
717 the class instance variable up front. */
718 t1 = build_function_type (TREE_TYPE (t1),
719 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
720 t2 = build_function_type (TREE_TYPE (t2),
721 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
722 t3 = merge_types (t1, t2);
723 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
724 TYPE_ARG_TYPES (t3));
725 t1 = build_exception_variant (t3, raises);
730 /* There is no need to merge attributes into a TYPENAME_TYPE.
731 When the type is instantiated it will have whatever
732 attributes result from the instantiation. */
738 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
740 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
743 return cp_build_type_attribute_variant (t1, attributes);
746 /* Return the common type of two types.
747 We assume that comptypes has already been done and returned 1;
748 if that isn't so, this may crash.
750 This is the type for the result of most arithmetic operations
751 if the operands have the given two types. */
754 common_type (tree t1, tree t2)
756 enum tree_code code1;
757 enum tree_code code2;
759 /* If one type is nonsense, bail. */
760 if (t1 == error_mark_node || t2 == error_mark_node)
761 return error_mark_node;
763 code1 = TREE_CODE (t1);
764 code2 = TREE_CODE (t2);
766 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
767 || code1 == VECTOR_TYPE)
768 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
769 || code2 == VECTOR_TYPE))
770 return type_after_usual_arithmetic_conversions (t1, t2);
772 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
773 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
774 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
775 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
776 "conversion", tf_warning_or_error);
781 /* Compare two exception specifier types for exactness or subsetness, if
782 allowed. Returns false for mismatch, true for match (same, or
785 [except.spec] "If a class X ... objects of class X or any class publicly
786 and unambiguously derived from X. Similarly, if a pointer type Y * ...
787 exceptions of type Y * or that are pointers to any type publicly and
788 unambiguously derived from Y. Otherwise a function only allows exceptions
789 that have the same type ..."
790 This does not mention cv qualifiers and is different to what throw
791 [except.throw] and catch [except.catch] will do. They will ignore the
792 top level cv qualifiers, and allow qualifiers in the pointer to class
795 We implement the letter of the standard. */
798 comp_except_types (tree a, tree b, bool exact)
800 if (same_type_p (a, b))
804 if (cp_type_quals (a) || cp_type_quals (b))
807 if (TREE_CODE (a) == POINTER_TYPE
808 && TREE_CODE (b) == POINTER_TYPE)
812 if (cp_type_quals (a) || cp_type_quals (b))
816 if (TREE_CODE (a) != RECORD_TYPE
817 || TREE_CODE (b) != RECORD_TYPE)
820 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
826 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
827 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
828 otherwise it must be exact. Exception lists are unordered, but
829 we've already filtered out duplicates. Most lists will be in order,
830 we should try to make use of that. */
833 comp_except_specs (const_tree t1, const_tree t2, bool exact)
842 if (t1 == NULL_TREE) /* T1 is ... */
843 return t2 == NULL_TREE || !exact;
844 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
845 return t2 != NULL_TREE && !TREE_VALUE (t2);
846 if (t2 == NULL_TREE) /* T2 is ... */
848 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
851 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
852 Count how many we find, to determine exactness. For exact matching and
853 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
855 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
857 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
859 tree a = TREE_VALUE (probe);
860 tree b = TREE_VALUE (t2);
862 if (comp_except_types (a, b, exact))
864 if (probe == base && exact)
865 base = TREE_CHAIN (probe);
870 if (probe == NULL_TREE)
873 return !exact || base == NULL_TREE || length == list_length (t1);
876 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
877 [] can match [size]. */
880 comp_array_types (const_tree t1, const_tree t2, bool allow_redeclaration)
889 /* The type of the array elements must be the same. */
890 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
893 d1 = TYPE_DOMAIN (t1);
894 d2 = TYPE_DOMAIN (t2);
899 /* If one of the arrays is dimensionless, and the other has a
900 dimension, they are of different types. However, it is valid to
908 declarations for an array object can specify
909 array types that differ by the presence or absence of a major
910 array bound (_dcl.array_). */
912 return allow_redeclaration;
914 /* Check that the dimensions are the same. */
916 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
918 max1 = TYPE_MAX_VALUE (d1);
919 max2 = TYPE_MAX_VALUE (d2);
920 if (processing_template_decl && !abi_version_at_least (2)
921 && !value_dependent_expression_p (max1)
922 && !value_dependent_expression_p (max2))
924 /* With abi-1 we do not fold non-dependent array bounds, (and
925 consequently mangle them incorrectly). We must therefore
926 fold them here, to verify the domains have the same
932 if (!cp_tree_equal (max1, max2))
938 /* Subroutine in comptypes. */
941 structural_comptypes (tree t1, tree t2, int strict)
946 /* Suppress errors caused by previously reported errors. */
947 if (t1 == error_mark_node || t2 == error_mark_node)
950 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
952 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
953 current instantiation. */
954 if (TREE_CODE (t1) == TYPENAME_TYPE)
955 t1 = resolve_typename_type (t1, /*only_current_p=*/true);
957 if (TREE_CODE (t2) == TYPENAME_TYPE)
958 t2 = resolve_typename_type (t2, /*only_current_p=*/true);
960 if (TYPE_PTRMEMFUNC_P (t1))
961 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
962 if (TYPE_PTRMEMFUNC_P (t2))
963 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
965 /* Different classes of types can't be compatible. */
966 if (TREE_CODE (t1) != TREE_CODE (t2))
969 /* Qualifiers must match. For array types, we will check when we
970 recur on the array element types. */
971 if (TREE_CODE (t1) != ARRAY_TYPE
972 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
974 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
977 /* Allow for two different type nodes which have essentially the same
978 definition. Note that we already checked for equality of the type
979 qualifiers (just above). */
981 if (TREE_CODE (t1) != ARRAY_TYPE
982 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
985 /* Compare the types. Break out if they could be the same. */
986 switch (TREE_CODE (t1))
990 /* All void and bool types are the same. */
994 case FIXED_POINT_TYPE:
996 /* With these nodes, we can't determine type equivalence by
997 looking at what is stored in the nodes themselves, because
998 two nodes might have different TYPE_MAIN_VARIANTs but still
999 represent the same type. For example, wchar_t and int could
1000 have the same properties (TYPE_PRECISION, TYPE_MIN_VALUE,
1001 TYPE_MAX_VALUE, etc.), but have different TYPE_MAIN_VARIANTs
1002 and are distinct types. On the other hand, int and the
1005 typedef int INT __attribute((may_alias));
1007 have identical properties, different TYPE_MAIN_VARIANTs, but
1008 represent the same type. The canonical type system keeps
1009 track of equivalence in this case, so we fall back on it. */
1010 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1012 case TEMPLATE_TEMPLATE_PARM:
1013 case BOUND_TEMPLATE_TEMPLATE_PARM:
1014 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1015 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1016 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1017 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1019 if (!comp_template_parms
1020 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1021 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1023 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1025 /* Don't check inheritance. */
1026 strict = COMPARE_STRICT;
1031 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1032 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1033 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1034 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1037 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1039 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1045 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1046 strict & ~COMPARE_REDECLARATION))
1048 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1052 case REFERENCE_TYPE:
1053 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2))
1055 /* fall through to checks for pointer types */
1058 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1059 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1060 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1066 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1068 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1073 /* Target types must match incl. qualifiers. */
1074 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1078 case TEMPLATE_TYPE_PARM:
1079 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1080 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1081 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1082 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1087 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1088 TYPENAME_TYPE_FULLNAME (t2)))
1090 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1094 case UNBOUND_CLASS_TEMPLATE:
1095 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1097 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1102 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1107 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1108 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1112 case TYPE_PACK_EXPANSION:
1113 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1114 PACK_EXPANSION_PATTERN (t2));
1117 if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1)
1118 != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2)
1119 || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1),
1120 DECLTYPE_TYPE_EXPR (t2)))
1128 /* If we get here, we know that from a target independent POV the
1129 types are the same. Make sure the target attributes are also
1131 return targetm.comp_type_attributes (t1, t2);
1134 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1135 is a bitwise-or of the COMPARE_* flags. */
1138 comptypes (tree t1, tree t2, int strict)
1140 if (strict == COMPARE_STRICT)
1145 if (t1 == error_mark_node || t2 == error_mark_node)
1148 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1149 /* At least one of the types requires structural equality, so
1150 perform a deep check. */
1151 return structural_comptypes (t1, t2, strict);
1153 #ifdef ENABLE_CHECKING
1154 if (USE_CANONICAL_TYPES)
1156 bool result = structural_comptypes (t1, t2, strict);
1158 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1159 /* The two types are structurally equivalent, but their
1160 canonical types were different. This is a failure of the
1161 canonical type propagation code.*/
1163 ("canonical types differ for identical types %T and %T",
1165 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1166 /* Two types are structurally different, but the canonical
1167 types are the same. This means we were over-eager in
1168 assigning canonical types. */
1170 ("same canonical type node for different types %T and %T",
1176 if (USE_CANONICAL_TYPES)
1177 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1180 return structural_comptypes (t1, t2, strict);
1182 else if (strict == COMPARE_STRUCTURAL)
1183 return structural_comptypes (t1, t2, COMPARE_STRICT);
1185 return structural_comptypes (t1, t2, strict);
1188 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1191 at_least_as_qualified_p (const_tree type1, const_tree type2)
1193 int q1 = cp_type_quals (type1);
1194 int q2 = cp_type_quals (type2);
1196 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1197 return (q1 & q2) == q2;
1200 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1201 more cv-qualified that TYPE1, and 0 otherwise. */
1204 comp_cv_qualification (const_tree type1, const_tree type2)
1206 int q1 = cp_type_quals (type1);
1207 int q2 = cp_type_quals (type2);
1212 if ((q1 & q2) == q2)
1214 else if ((q1 & q2) == q1)
1220 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1221 subset of the cv-qualification signature of TYPE2, and the types
1222 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1225 comp_cv_qual_signature (tree type1, tree type2)
1227 if (comp_ptr_ttypes_real (type2, type1, -1))
1229 else if (comp_ptr_ttypes_real (type1, type2, -1))
1235 /* Subroutines of `comptypes'. */
1237 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1238 equivalent in the sense that functions with those parameter types
1239 can have equivalent types. The two lists must be equivalent,
1240 element by element. */
1243 compparms (const_tree parms1, const_tree parms2)
1247 /* An unspecified parmlist matches any specified parmlist
1248 whose argument types don't need default promotions. */
1250 for (t1 = parms1, t2 = parms2;
1252 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1254 /* If one parmlist is shorter than the other,
1255 they fail to match. */
1258 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1265 /* Process a sizeof or alignof expression where the operand is a
1269 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1274 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1275 if (type == error_mark_node)
1276 return error_mark_node;
1278 type = non_reference (type);
1279 if (TREE_CODE (type) == METHOD_TYPE)
1281 if (complain && (pedantic || warn_pointer_arith))
1282 pedwarn ("invalid application of %qs to a member function",
1283 operator_name_info[(int) op].name);
1284 value = size_one_node;
1287 dependent_p = dependent_type_p (type);
1289 complete_type (type);
1291 /* VLA types will have a non-constant size. In the body of an
1292 uninstantiated template, we don't need to try to compute the
1293 value, because the sizeof expression is not an integral
1294 constant expression in that case. And, if we do try to
1295 compute the value, we'll likely end up with SAVE_EXPRs, which
1296 the template substitution machinery does not expect to see. */
1297 || (processing_template_decl
1298 && COMPLETE_TYPE_P (type)
1299 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1301 value = build_min (op, size_type_node, type);
1302 TREE_READONLY (value) = 1;
1306 return c_sizeof_or_alignof_type (complete_type (type),
1311 /* Return the size of the type, without producing any warnings for
1312 types whose size cannot be taken. This routine should be used only
1313 in some other routine that has already produced a diagnostic about
1314 using the size of such a type. */
1316 cxx_sizeof_nowarn (tree type)
1318 if (TREE_CODE (type) == FUNCTION_TYPE
1319 || TREE_CODE (type) == VOID_TYPE
1320 || TREE_CODE (type) == ERROR_MARK)
1321 return size_one_node;
1322 else if (!COMPLETE_TYPE_P (type))
1323 return size_zero_node;
1325 return cxx_sizeof_or_alignof_type (type, SIZEOF_EXPR, false);
1328 /* Process a sizeof expression where the operand is an expression. */
1331 cxx_sizeof_expr (tree e, tsubst_flags_t complain)
1333 if (e == error_mark_node)
1334 return error_mark_node;
1336 if (processing_template_decl)
1338 e = build_min (SIZEOF_EXPR, size_type_node, e);
1339 TREE_SIDE_EFFECTS (e) = 0;
1340 TREE_READONLY (e) = 1;
1345 if (TREE_CODE (e) == COMPONENT_REF
1346 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1347 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1349 if (complain & tf_error)
1350 error ("invalid application of %<sizeof%> to a bit-field");
1352 return error_mark_node;
1355 else if (is_overloaded_fn (e))
1357 if (complain & tf_error)
1358 permerror ("ISO C++ forbids applying %<sizeof%> to an expression of "
1361 return error_mark_node;
1364 else if (type_unknown_p (e))
1366 if (complain & tf_error)
1367 cxx_incomplete_type_error (e, TREE_TYPE (e));
1369 return error_mark_node;
1375 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, complain & tf_error);
1378 /* Implement the __alignof keyword: Return the minimum required
1379 alignment of E, measured in bytes. For VAR_DECL's and
1380 FIELD_DECL's return DECL_ALIGN (which can be set from an
1381 "aligned" __attribute__ specification). */
1384 cxx_alignof_expr (tree e, tsubst_flags_t complain)
1388 if (e == error_mark_node)
1389 return error_mark_node;
1391 if (processing_template_decl)
1393 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1394 TREE_SIDE_EFFECTS (e) = 0;
1395 TREE_READONLY (e) = 1;
1400 if (TREE_CODE (e) == VAR_DECL)
1401 t = size_int (DECL_ALIGN_UNIT (e));
1402 else if (TREE_CODE (e) == COMPONENT_REF
1403 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1404 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1406 if (complain & tf_error)
1407 error ("invalid application of %<__alignof%> to a bit-field");
1409 return error_mark_node;
1412 else if (TREE_CODE (e) == COMPONENT_REF
1413 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1414 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1415 else if (is_overloaded_fn (e))
1417 if (complain & tf_error)
1418 permerror ("ISO C++ forbids applying %<__alignof%> to an expression of "
1421 return error_mark_node;
1422 if (TREE_CODE (e) == FUNCTION_DECL)
1423 t = size_int (DECL_ALIGN_UNIT (e));
1427 else if (type_unknown_p (e))
1429 if (complain & tf_error)
1430 cxx_incomplete_type_error (e, TREE_TYPE (e));
1432 return error_mark_node;
1436 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR,
1437 complain & tf_error);
1439 return fold_convert (size_type_node, t);
1442 /* Process a sizeof or alignof expression E with code OP where the operand
1443 is an expression. */
1446 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op, bool complain)
1448 if (op == SIZEOF_EXPR)
1449 return cxx_sizeof_expr (e, complain? tf_warning_or_error : tf_none);
1451 return cxx_alignof_expr (e, complain? tf_warning_or_error : tf_none);
1454 /* EXPR is being used in a context that is not a function call.
1459 The expression can be used only as the left-hand operand of a
1460 member function call.
1462 [expr.mptr.operator]
1464 If the result of .* or ->* is a function, then that result can be
1465 used only as the operand for the function call operator ().
1467 by issuing an error message if appropriate. Returns true iff EXPR
1468 violates these rules. */
1471 invalid_nonstatic_memfn_p (const_tree expr, tsubst_flags_t complain)
1473 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1475 if (complain & tf_error)
1476 error ("invalid use of non-static member function");
1482 /* If EXP is a reference to a bitfield, and the type of EXP does not
1483 match the declared type of the bitfield, return the declared type
1484 of the bitfield. Otherwise, return NULL_TREE. */
1487 is_bitfield_expr_with_lowered_type (const_tree exp)
1489 switch (TREE_CODE (exp))
1492 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)
1493 ? TREE_OPERAND (exp, 1)
1494 : TREE_OPERAND (exp, 0)))
1496 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1499 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1503 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1509 field = TREE_OPERAND (exp, 1);
1510 if (TREE_CODE (field) != FIELD_DECL || !DECL_BIT_FIELD_TYPE (field))
1512 if (same_type_ignoring_top_level_qualifiers_p
1513 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1515 return DECL_BIT_FIELD_TYPE (field);
1519 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0)))
1520 == TYPE_MAIN_VARIANT (TREE_TYPE (exp)))
1521 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1529 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1530 bitfield with a lowered type, the type of EXP is returned, rather
1534 unlowered_expr_type (const_tree exp)
1538 type = is_bitfield_expr_with_lowered_type (exp);
1540 type = TREE_TYPE (exp);
1545 /* Perform the conversions in [expr] that apply when an lvalue appears
1546 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1547 function-to-pointer conversions. In addition, manifest constants
1548 are replaced by their values, and bitfield references are converted
1549 to their declared types.
1551 Although the returned value is being used as an rvalue, this
1552 function does not wrap the returned expression in a
1553 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1554 that the return value is no longer an lvalue. */
1557 decay_conversion (tree exp)
1560 enum tree_code code;
1562 type = TREE_TYPE (exp);
1563 if (type == error_mark_node)
1564 return error_mark_node;
1566 if (type_unknown_p (exp))
1568 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1569 return error_mark_node;
1572 exp = decl_constant_value (exp);
1573 if (error_operand_p (exp))
1574 return error_mark_node;
1576 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1577 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1578 code = TREE_CODE (type);
1579 if (code == VOID_TYPE)
1581 error ("void value not ignored as it ought to be");
1582 return error_mark_node;
1584 if (invalid_nonstatic_memfn_p (exp, tf_warning_or_error))
1585 return error_mark_node;
1586 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1587 return cp_build_unary_op (ADDR_EXPR, exp, 0, tf_warning_or_error);
1588 if (code == ARRAY_TYPE)
1593 if (TREE_CODE (exp) == INDIRECT_REF)
1594 return build_nop (build_pointer_type (TREE_TYPE (type)),
1595 TREE_OPERAND (exp, 0));
1597 if (TREE_CODE (exp) == COMPOUND_EXPR)
1599 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1600 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1601 TREE_OPERAND (exp, 0), op1);
1605 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1607 error ("invalid use of non-lvalue array");
1608 return error_mark_node;
1611 ptrtype = build_pointer_type (TREE_TYPE (type));
1613 if (TREE_CODE (exp) == VAR_DECL)
1615 if (!cxx_mark_addressable (exp))
1616 return error_mark_node;
1617 adr = build_nop (ptrtype, build_address (exp));
1620 /* This way is better for a COMPONENT_REF since it can
1621 simplify the offset for a component. */
1622 adr = cp_build_unary_op (ADDR_EXPR, exp, 1, tf_warning_or_error);
1623 return cp_convert (ptrtype, adr);
1626 /* If a bitfield is used in a context where integral promotion
1627 applies, then the caller is expected to have used
1628 default_conversion. That function promotes bitfields correctly
1629 before calling this function. At this point, if we have a
1630 bitfield referenced, we may assume that is not subject to
1631 promotion, and that, therefore, the type of the resulting rvalue
1632 is the declared type of the bitfield. */
1633 exp = convert_bitfield_to_declared_type (exp);
1635 /* We do not call rvalue() here because we do not want to wrap EXP
1636 in a NON_LVALUE_EXPR. */
1640 Non-class rvalues always have cv-unqualified types. */
1641 type = TREE_TYPE (exp);
1642 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1643 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1648 /* Perform prepatory conversions, as part of the "usual arithmetic
1649 conversions". In particular, as per [expr]:
1651 Whenever an lvalue expression appears as an operand of an
1652 operator that expects the rvalue for that operand, the
1653 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1654 standard conversions are applied to convert the expression to an
1657 In addition, we perform integral promotions here, as those are
1658 applied to both operands to a binary operator before determining
1659 what additional conversions should apply. */
1662 default_conversion (tree exp)
1664 /* Perform the integral promotions first so that bitfield
1665 expressions (which may promote to "int", even if the bitfield is
1666 declared "unsigned") are promoted correctly. */
1667 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1668 exp = perform_integral_promotions (exp);
1669 /* Perform the other conversions. */
1670 exp = decay_conversion (exp);
1675 /* EXPR is an expression with an integral or enumeration type.
1676 Perform the integral promotions in [conv.prom], and return the
1680 perform_integral_promotions (tree expr)
1687 If the bitfield has an enumerated type, it is treated as any
1688 other value of that type for promotion purposes. */
1689 type = is_bitfield_expr_with_lowered_type (expr);
1690 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1691 type = TREE_TYPE (expr);
1692 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1693 promoted_type = type_promotes_to (type);
1694 if (type != promoted_type)
1695 expr = cp_convert (promoted_type, expr);
1699 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1703 inline_conversion (tree exp)
1705 if (TREE_CODE (exp) == FUNCTION_DECL)
1706 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1711 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1712 decay_conversion to one. */
1715 string_conv_p (const_tree totype, const_tree exp, int warn)
1719 if (TREE_CODE (totype) != POINTER_TYPE)
1722 t = TREE_TYPE (totype);
1723 if (!same_type_p (t, char_type_node)
1724 && !same_type_p (t, char16_type_node)
1725 && !same_type_p (t, char32_type_node)
1726 && !same_type_p (t, wchar_type_node))
1729 if (TREE_CODE (exp) == STRING_CST)
1731 /* Make sure that we don't try to convert between char and wide chars. */
1732 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1737 /* Is this a string constant which has decayed to 'const char *'? */
1738 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1739 if (!same_type_p (TREE_TYPE (exp), t))
1742 if (TREE_CODE (exp) != ADDR_EXPR
1743 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1747 /* This warning is not very useful, as it complains about printf. */
1749 warning (OPT_Wwrite_strings,
1750 "deprecated conversion from string constant to %qT",
1756 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1757 can, for example, use as an lvalue. This code used to be in
1758 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1759 expressions, where we're dealing with aggregates. But now it's again only
1760 called from unary_complex_lvalue. The case (in particular) that led to
1761 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1765 rationalize_conditional_expr (enum tree_code code, tree t,
1766 tsubst_flags_t complain)
1768 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1769 the first operand is always the one to be used if both operands
1770 are equal, so we know what conditional expression this used to be. */
1771 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1773 tree op0 = TREE_OPERAND (t, 0);
1774 tree op1 = TREE_OPERAND (t, 1);
1776 /* The following code is incorrect if either operand side-effects. */
1777 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1778 && !TREE_SIDE_EFFECTS (op1));
1780 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1781 ? LE_EXPR : GE_EXPR),
1782 op0, TREE_CODE (op0),
1783 op1, TREE_CODE (op1),
1784 /*overloaded_p=*/NULL,
1786 cp_build_unary_op (code, op0, 0, complain),
1787 cp_build_unary_op (code, op1, 0, complain),
1792 build_conditional_expr (TREE_OPERAND (t, 0),
1793 cp_build_unary_op (code, TREE_OPERAND (t, 1), 0,
1795 cp_build_unary_op (code, TREE_OPERAND (t, 2), 0,
1800 /* Given the TYPE of an anonymous union field inside T, return the
1801 FIELD_DECL for the field. If not found return NULL_TREE. Because
1802 anonymous unions can nest, we must also search all anonymous unions
1803 that are directly reachable. */
1806 lookup_anon_field (tree t, tree type)
1810 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1812 if (TREE_STATIC (field))
1814 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1817 /* If we find it directly, return the field. */
1818 if (DECL_NAME (field) == NULL_TREE
1819 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1824 /* Otherwise, it could be nested, search harder. */
1825 if (DECL_NAME (field) == NULL_TREE
1826 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1828 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1836 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1837 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1838 non-NULL, it indicates the path to the base used to name MEMBER.
1839 If PRESERVE_REFERENCE is true, the expression returned will have
1840 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1841 returned will have the type referred to by the reference.
1843 This function does not perform access control; that is either done
1844 earlier by the parser when the name of MEMBER is resolved to MEMBER
1845 itself, or later when overload resolution selects one of the
1846 functions indicated by MEMBER. */
1849 build_class_member_access_expr (tree object, tree member,
1850 tree access_path, bool preserve_reference,
1851 tsubst_flags_t complain)
1855 tree result = NULL_TREE;
1857 if (error_operand_p (object) || error_operand_p (member))
1858 return error_mark_node;
1860 gcc_assert (DECL_P (member) || BASELINK_P (member));
1864 The type of the first expression shall be "class object" (of a
1866 object_type = TREE_TYPE (object);
1867 if (!currently_open_class (object_type)
1868 && !complete_type_or_else (object_type, object))
1869 return error_mark_node;
1870 if (!CLASS_TYPE_P (object_type))
1872 if (complain & tf_error)
1873 error ("request for member %qD in %qE, which is of non-class type %qT",
1874 member, object, object_type);
1875 return error_mark_node;
1878 /* The standard does not seem to actually say that MEMBER must be a
1879 member of OBJECT_TYPE. However, that is clearly what is
1881 if (DECL_P (member))
1883 member_scope = DECL_CLASS_CONTEXT (member);
1885 if (TREE_DEPRECATED (member))
1886 warn_deprecated_use (member);
1889 member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member));
1890 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1891 presently be the anonymous union. Go outwards until we find a
1892 type related to OBJECT_TYPE. */
1893 while (ANON_AGGR_TYPE_P (member_scope)
1894 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1896 member_scope = TYPE_CONTEXT (member_scope);
1897 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1899 if (complain & tf_error)
1901 if (TREE_CODE (member) == FIELD_DECL)
1902 error ("invalid use of nonstatic data member %qE", member);
1904 error ("%qD is not a member of %qT", member, object_type);
1906 return error_mark_node;
1909 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1910 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1911 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1913 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1915 object = cp_build_indirect_ref (temp, NULL, complain);
1918 /* In [expr.ref], there is an explicit list of the valid choices for
1919 MEMBER. We check for each of those cases here. */
1920 if (TREE_CODE (member) == VAR_DECL)
1922 /* A static data member. */
1924 /* If OBJECT has side-effects, they are supposed to occur. */
1925 if (TREE_SIDE_EFFECTS (object))
1926 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1928 else if (TREE_CODE (member) == FIELD_DECL)
1930 /* A non-static data member. */
1935 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1936 && integer_zerop (TREE_OPERAND (object, 0)));
1938 /* Convert OBJECT to the type of MEMBER. */
1939 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1940 TYPE_MAIN_VARIANT (member_scope)))
1945 binfo = lookup_base (access_path ? access_path : object_type,
1946 member_scope, ba_unique, &kind);
1947 if (binfo == error_mark_node)
1948 return error_mark_node;
1950 /* It is invalid to try to get to a virtual base of a
1951 NULL object. The most common cause is invalid use of
1953 if (null_object_p && kind == bk_via_virtual)
1955 if (complain & tf_error)
1957 error ("invalid access to non-static data member %qD of "
1960 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1962 return error_mark_node;
1965 /* Convert to the base. */
1966 object = build_base_path (PLUS_EXPR, object, binfo,
1968 /* If we found the base successfully then we should be able
1969 to convert to it successfully. */
1970 gcc_assert (object != error_mark_node);
1973 /* Complain about other invalid uses of offsetof, even though they will
1974 give the right answer. Note that we complain whether or not they
1975 actually used the offsetof macro, since there's no way to know at this
1976 point. So we just give a warning, instead of a pedwarn. */
1977 /* Do not produce this warning for base class field references, because
1978 we know for a fact that didn't come from offsetof. This does occur
1979 in various testsuite cases where a null object is passed where a
1980 vtable access is required. */
1981 if (null_object_p && warn_invalid_offsetof
1982 && CLASSTYPE_NON_POD_P (object_type)
1983 && !DECL_FIELD_IS_BASE (member)
1985 && (complain & tf_warning))
1987 warning (OPT_Winvalid_offsetof,
1988 "invalid access to non-static data member %qD "
1989 " of NULL object", member);
1990 warning (OPT_Winvalid_offsetof,
1991 "(perhaps the %<offsetof%> macro was used incorrectly)");
1994 /* If MEMBER is from an anonymous aggregate, we have converted
1995 OBJECT so that it refers to the class containing the
1996 anonymous union. Generate a reference to the anonymous union
1997 itself, and recur to find MEMBER. */
1998 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1999 /* When this code is called from build_field_call, the
2000 object already has the type of the anonymous union.
2001 That is because the COMPONENT_REF was already
2002 constructed, and was then disassembled before calling
2003 build_field_call. After the function-call code is
2004 cleaned up, this waste can be eliminated. */
2005 && (!same_type_ignoring_top_level_qualifiers_p
2006 (TREE_TYPE (object), DECL_CONTEXT (member))))
2008 tree anonymous_union;
2010 anonymous_union = lookup_anon_field (TREE_TYPE (object),
2011 DECL_CONTEXT (member));
2012 object = build_class_member_access_expr (object,
2014 /*access_path=*/NULL_TREE,
2019 /* Compute the type of the field, as described in [expr.ref]. */
2020 type_quals = TYPE_UNQUALIFIED;
2021 member_type = TREE_TYPE (member);
2022 if (TREE_CODE (member_type) != REFERENCE_TYPE)
2024 type_quals = (cp_type_quals (member_type)
2025 | cp_type_quals (object_type));
2027 /* A field is const (volatile) if the enclosing object, or the
2028 field itself, is const (volatile). But, a mutable field is
2029 not const, even within a const object. */
2030 if (DECL_MUTABLE_P (member))
2031 type_quals &= ~TYPE_QUAL_CONST;
2032 member_type = cp_build_qualified_type (member_type, type_quals);
2035 result = build3 (COMPONENT_REF, member_type, object, member,
2037 result = fold_if_not_in_template (result);
2039 /* Mark the expression const or volatile, as appropriate. Even
2040 though we've dealt with the type above, we still have to mark the
2041 expression itself. */
2042 if (type_quals & TYPE_QUAL_CONST)
2043 TREE_READONLY (result) = 1;
2044 if (type_quals & TYPE_QUAL_VOLATILE)
2045 TREE_THIS_VOLATILE (result) = 1;
2047 else if (BASELINK_P (member))
2049 /* The member is a (possibly overloaded) member function. */
2053 /* If the MEMBER is exactly one static member function, then we
2054 know the type of the expression. Otherwise, we must wait
2055 until overload resolution has been performed. */
2056 functions = BASELINK_FUNCTIONS (member);
2057 if (TREE_CODE (functions) == FUNCTION_DECL
2058 && DECL_STATIC_FUNCTION_P (functions))
2059 type = TREE_TYPE (functions);
2061 type = unknown_type_node;
2062 /* Note that we do not convert OBJECT to the BASELINK_BINFO
2063 base. That will happen when the function is called. */
2064 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
2066 else if (TREE_CODE (member) == CONST_DECL)
2068 /* The member is an enumerator. */
2070 /* If OBJECT has side-effects, they are supposed to occur. */
2071 if (TREE_SIDE_EFFECTS (object))
2072 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2077 if (complain & tf_error)
2078 error ("invalid use of %qD", member);
2079 return error_mark_node;
2082 if (!preserve_reference)
2085 If E2 is declared to have type "reference to T", then ... the
2086 type of E1.E2 is T. */
2087 result = convert_from_reference (result);
2092 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
2093 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2096 lookup_destructor (tree object, tree scope, tree dtor_name)
2098 tree object_type = TREE_TYPE (object);
2099 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2102 if (scope && !check_dtor_name (scope, dtor_type))
2104 error ("qualified type %qT does not match destructor name ~%qT",
2106 return error_mark_node;
2108 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2110 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2111 TYPE_MAIN_VARIANT (object_type), dtor_type);
2112 return error_mark_node;
2114 expr = lookup_member (dtor_type, complete_dtor_identifier,
2115 /*protect=*/1, /*want_type=*/false);
2116 expr = (adjust_result_of_qualified_name_lookup
2117 (expr, dtor_type, object_type));
2121 /* An expression of the form "A::template B" has been resolved to
2122 DECL. Issue a diagnostic if B is not a template or template
2126 check_template_keyword (tree decl)
2128 /* The standard says:
2132 If a name prefixed by the keyword template is not a member
2133 template, the program is ill-formed.
2135 DR 228 removed the restriction that the template be a member
2138 DR 96, if accepted would add the further restriction that explicit
2139 template arguments must be provided if the template keyword is
2140 used, but, as of 2005-10-16, that DR is still in "drafting". If
2141 this DR is accepted, then the semantic checks here can be
2142 simplified, as the entity named must in fact be a template
2143 specialization, rather than, as at present, a set of overloaded
2144 functions containing at least one template function. */
2145 if (TREE_CODE (decl) != TEMPLATE_DECL
2146 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2148 if (!is_overloaded_fn (decl))
2149 permerror ("%qD is not a template", decl);
2154 if (BASELINK_P (fns))
2155 fns = BASELINK_FUNCTIONS (fns);
2158 tree fn = OVL_CURRENT (fns);
2159 if (TREE_CODE (fn) == TEMPLATE_DECL
2160 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2162 if (TREE_CODE (fn) == FUNCTION_DECL
2163 && DECL_USE_TEMPLATE (fn)
2164 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2166 fns = OVL_NEXT (fns);
2169 permerror ("%qD is not a template", decl);
2174 /* This function is called by the parser to process a class member
2175 access expression of the form OBJECT.NAME. NAME is a node used by
2176 the parser to represent a name; it is not yet a DECL. It may,
2177 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2178 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2179 there is no reason to do the lookup twice, so the parser keeps the
2180 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2181 be a template via the use of the "A::template B" syntax. */
2184 finish_class_member_access_expr (tree object, tree name, bool template_p,
2185 tsubst_flags_t complain)
2190 tree access_path = NULL_TREE;
2191 tree orig_object = object;
2192 tree orig_name = name;
2194 if (object == error_mark_node || name == error_mark_node)
2195 return error_mark_node;
2197 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2198 if (!objc_is_public (object, name))
2199 return error_mark_node;
2201 object_type = TREE_TYPE (object);
2203 if (processing_template_decl)
2205 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2206 dependent_type_p (object_type)
2207 /* If NAME is just an IDENTIFIER_NODE, then the expression
2209 || TREE_CODE (object) == IDENTIFIER_NODE
2210 /* If NAME is "f<args>", where either 'f' or 'args' is
2211 dependent, then the expression is dependent. */
2212 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2213 && dependent_template_id_p (TREE_OPERAND (name, 0),
2214 TREE_OPERAND (name, 1)))
2215 /* If NAME is "T::X" where "T" is dependent, then the
2216 expression is dependent. */
2217 || (TREE_CODE (name) == SCOPE_REF
2218 && TYPE_P (TREE_OPERAND (name, 0))
2219 && dependent_type_p (TREE_OPERAND (name, 0))))
2220 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2221 object = build_non_dependent_expr (object);
2226 The type of the first expression shall be "class object" (of a
2228 if (!currently_open_class (object_type)
2229 && !complete_type_or_else (object_type, object))
2230 return error_mark_node;
2231 if (!CLASS_TYPE_P (object_type))
2233 if (complain & tf_error)
2234 error ("request for member %qD in %qE, which is of non-class type %qT",
2235 name, object, object_type);
2236 return error_mark_node;
2239 if (BASELINK_P (name))
2240 /* A member function that has already been looked up. */
2244 bool is_template_id = false;
2245 tree template_args = NULL_TREE;
2248 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2250 is_template_id = true;
2251 template_args = TREE_OPERAND (name, 1);
2252 name = TREE_OPERAND (name, 0);
2254 if (TREE_CODE (name) == OVERLOAD)
2255 name = DECL_NAME (get_first_fn (name));
2256 else if (DECL_P (name))
2257 name = DECL_NAME (name);
2260 if (TREE_CODE (name) == SCOPE_REF)
2262 /* A qualified name. The qualifying class or namespace `S'
2263 has already been looked up; it is either a TYPE or a
2265 scope = TREE_OPERAND (name, 0);
2266 name = TREE_OPERAND (name, 1);
2268 /* If SCOPE is a namespace, then the qualified name does not
2269 name a member of OBJECT_TYPE. */
2270 if (TREE_CODE (scope) == NAMESPACE_DECL)
2272 if (complain & tf_error)
2273 error ("%<%D::%D%> is not a member of %qT",
2274 scope, name, object_type);
2275 return error_mark_node;
2278 gcc_assert (CLASS_TYPE_P (scope));
2279 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2280 || TREE_CODE (name) == BIT_NOT_EXPR);
2282 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2283 access_path = lookup_base (object_type, scope, ba_check, NULL);
2284 if (access_path == error_mark_node)
2285 return error_mark_node;
2288 if (complain & tf_error)
2289 error ("%qT is not a base of %qT", scope, object_type);
2290 return error_mark_node;
2296 access_path = object_type;
2299 if (TREE_CODE (name) == BIT_NOT_EXPR)
2300 member = lookup_destructor (object, scope, name);
2303 /* Look up the member. */
2304 member = lookup_member (access_path, name, /*protect=*/1,
2305 /*want_type=*/false);
2306 if (member == NULL_TREE)
2308 if (complain & tf_error)
2309 error ("%qD has no member named %qE", object_type, name);
2310 return error_mark_node;
2312 if (member == error_mark_node)
2313 return error_mark_node;
2318 tree template = member;
2320 if (BASELINK_P (template))
2321 template = lookup_template_function (template, template_args);
2324 if (complain & tf_error)
2325 error ("%qD is not a member template function", name);
2326 return error_mark_node;
2331 if (TREE_DEPRECATED (member))
2332 warn_deprecated_use (member);
2335 check_template_keyword (member);
2337 expr = build_class_member_access_expr (object, member, access_path,
2338 /*preserve_reference=*/false,
2340 if (processing_template_decl && expr != error_mark_node)
2342 if (BASELINK_P (member))
2344 if (TREE_CODE (orig_name) == SCOPE_REF)
2345 BASELINK_QUALIFIED_P (member) = 1;
2348 return build_min_non_dep (COMPONENT_REF, expr,
2349 orig_object, orig_name,
2356 /* Return an expression for the MEMBER_NAME field in the internal
2357 representation of PTRMEM, a pointer-to-member function. (Each
2358 pointer-to-member function type gets its own RECORD_TYPE so it is
2359 more convenient to access the fields by name than by FIELD_DECL.)
2360 This routine converts the NAME to a FIELD_DECL and then creates the
2361 node for the complete expression. */
2364 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2370 /* This code is a stripped down version of
2371 build_class_member_access_expr. It does not work to use that
2372 routine directly because it expects the object to be of class
2374 ptrmem_type = TREE_TYPE (ptrmem);
2375 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2376 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2377 /*want_type=*/false);
2378 member_type = cp_build_qualified_type (TREE_TYPE (member),
2379 cp_type_quals (ptrmem_type));
2380 return fold_build3 (COMPONENT_REF, member_type,
2381 ptrmem, member, NULL_TREE);
2384 /* Given an expression PTR for a pointer, return an expression
2385 for the value pointed to.
2386 ERRORSTRING is the name of the operator to appear in error messages.
2388 This function may need to overload OPERATOR_FNNAME.
2389 Must also handle REFERENCE_TYPEs for C++. */
2392 build_x_indirect_ref (tree expr, const char *errorstring,
2393 tsubst_flags_t complain)
2395 tree orig_expr = expr;
2398 if (processing_template_decl)
2400 if (type_dependent_expression_p (expr))
2401 return build_min_nt (INDIRECT_REF, expr);
2402 expr = build_non_dependent_expr (expr);
2405 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2406 NULL_TREE, /*overloaded_p=*/NULL, complain);
2408 rval = cp_build_indirect_ref (expr, errorstring, complain);
2410 if (processing_template_decl && rval != error_mark_node)
2411 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2416 /* Helper function called from c-common. */
2418 build_indirect_ref (tree ptr, const char *errorstring)
2420 return cp_build_indirect_ref (ptr, errorstring, tf_warning_or_error);
2424 cp_build_indirect_ref (tree ptr, const char *errorstring,
2425 tsubst_flags_t complain)
2429 if (ptr == error_mark_node)
2430 return error_mark_node;
2432 if (ptr == current_class_ptr)
2433 return current_class_ref;
2435 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2436 ? ptr : decay_conversion (ptr));
2437 type = TREE_TYPE (pointer);
2439 if (POINTER_TYPE_P (type))
2443 If the type of the expression is "pointer to T," the type
2444 of the result is "T."
2446 We must use the canonical variant because certain parts of
2447 the back end, like fold, do pointer comparisons between
2449 tree t = canonical_type_variant (TREE_TYPE (type));
2451 if (CONVERT_EXPR_P (ptr)
2452 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2454 /* If a warning is issued, mark it to avoid duplicates from
2455 the backend. This only needs to be done at
2456 warn_strict_aliasing > 2. */
2457 if (warn_strict_aliasing > 2)
2458 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2459 type, TREE_OPERAND (ptr, 0)))
2460 TREE_NO_WARNING (ptr) = 1;
2463 if (VOID_TYPE_P (t))
2465 /* A pointer to incomplete type (other than cv void) can be
2466 dereferenced [expr.unary.op]/1 */
2467 if (complain & tf_error)
2468 error ("%qT is not a pointer-to-object type", type);
2469 return error_mark_node;
2471 else if (TREE_CODE (pointer) == ADDR_EXPR
2472 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2473 /* The POINTER was something like `&x'. We simplify `*&x' to
2475 return TREE_OPERAND (pointer, 0);
2478 tree ref = build1 (INDIRECT_REF, t, pointer);
2480 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2481 so that we get the proper error message if the result is used
2482 to assign to. Also, &* is supposed to be a no-op. */
2483 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2484 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2485 TREE_SIDE_EFFECTS (ref)
2486 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2490 else if (!(complain & tf_error))
2491 /* Don't emit any errors; we'll just return ERROR_MARK_NODE later. */
2493 /* `pointer' won't be an error_mark_node if we were given a
2494 pointer to member, so it's cool to check for this here. */
2495 else if (TYPE_PTR_TO_MEMBER_P (type))
2496 error ("invalid use of %qs on pointer to member", errorstring);
2497 else if (pointer != error_mark_node)
2500 error ("invalid type argument of %qs", errorstring);
2502 error ("invalid type argument");
2504 return error_mark_node;
2507 /* This handles expressions of the form "a[i]", which denotes
2510 This is logically equivalent in C to *(a+i), but we may do it differently.
2511 If A is a variable or a member, we generate a primitive ARRAY_REF.
2512 This avoids forcing the array out of registers, and can work on
2513 arrays that are not lvalues (for example, members of structures returned
2516 If INDEX is of some user-defined type, it must be converted to
2517 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2518 will inherit the type of the array, which will be some pointer type. */
2521 build_array_ref (tree array, tree idx)
2525 error ("subscript missing in array reference");
2526 return error_mark_node;
2529 if (TREE_TYPE (array) == error_mark_node
2530 || TREE_TYPE (idx) == error_mark_node)
2531 return error_mark_node;
2533 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2535 switch (TREE_CODE (array))
2539 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2540 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2541 TREE_OPERAND (array, 0), value);
2545 return build_conditional_expr
2546 (TREE_OPERAND (array, 0),
2547 build_array_ref (TREE_OPERAND (array, 1), idx),
2548 build_array_ref (TREE_OPERAND (array, 2), idx),
2549 tf_warning_or_error);
2555 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2559 warn_array_subscript_with_type_char (idx);
2561 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2563 error ("array subscript is not an integer");
2564 return error_mark_node;
2567 /* Apply integral promotions *after* noticing character types.
2568 (It is unclear why we do these promotions -- the standard
2569 does not say that we should. In fact, the natural thing would
2570 seem to be to convert IDX to ptrdiff_t; we're performing
2571 pointer arithmetic.) */
2572 idx = perform_integral_promotions (idx);
2574 /* An array that is indexed by a non-constant
2575 cannot be stored in a register; we must be able to do
2576 address arithmetic on its address.
2577 Likewise an array of elements of variable size. */
2578 if (TREE_CODE (idx) != INTEGER_CST
2579 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2580 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2583 if (!cxx_mark_addressable (array))
2584 return error_mark_node;
2587 /* An array that is indexed by a constant value which is not within
2588 the array bounds cannot be stored in a register either; because we
2589 would get a crash in store_bit_field/extract_bit_field when trying
2590 to access a non-existent part of the register. */
2591 if (TREE_CODE (idx) == INTEGER_CST
2592 && TYPE_DOMAIN (TREE_TYPE (array))
2593 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2595 if (!cxx_mark_addressable (array))
2596 return error_mark_node;
2599 if (pedantic && !lvalue_p (array))
2600 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2602 /* Note in C++ it is valid to subscript a `register' array, since
2603 it is valid to take the address of something with that
2604 storage specification. */
2608 while (TREE_CODE (foo) == COMPONENT_REF)
2609 foo = TREE_OPERAND (foo, 0);
2610 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2611 warning (OPT_Wextra, "subscripting array declared %<register%>");
2614 type = TREE_TYPE (TREE_TYPE (array));
2615 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2616 /* Array ref is const/volatile if the array elements are
2617 or if the array is.. */
2618 TREE_READONLY (rval)
2619 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2620 TREE_SIDE_EFFECTS (rval)
2621 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2622 TREE_THIS_VOLATILE (rval)
2623 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2624 return require_complete_type (fold_if_not_in_template (rval));
2628 tree ar = default_conversion (array);
2629 tree ind = default_conversion (idx);
2631 /* Put the integer in IND to simplify error checking. */
2632 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2639 if (ar == error_mark_node)
2642 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2644 error ("subscripted value is neither array nor pointer");
2645 return error_mark_node;
2647 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2649 error ("array subscript is not an integer");
2650 return error_mark_node;
2653 warn_array_subscript_with_type_char (idx);
2655 return cp_build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind,
2656 tf_warning_or_error),
2658 tf_warning_or_error);
2662 /* Resolve a pointer to member function. INSTANCE is the object
2663 instance to use, if the member points to a virtual member.
2665 This used to avoid checking for virtual functions if basetype
2666 has no virtual functions, according to an earlier ANSI draft.
2667 With the final ISO C++ rules, such an optimization is
2668 incorrect: A pointer to a derived member can be static_cast
2669 to pointer-to-base-member, as long as the dynamic object
2670 later has the right member. */
2673 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2675 if (TREE_CODE (function) == OFFSET_REF)
2676 function = TREE_OPERAND (function, 1);
2678 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2680 tree idx, delta, e1, e2, e3, vtbl, basetype;
2681 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2683 tree instance_ptr = *instance_ptrptr;
2684 tree instance_save_expr = 0;
2685 if (instance_ptr == error_mark_node)
2687 if (TREE_CODE (function) == PTRMEM_CST)
2689 /* Extracting the function address from a pmf is only
2690 allowed with -Wno-pmf-conversions. It only works for
2692 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2693 e1 = convert (fntype, e1);
2698 error ("object missing in use of %qE", function);
2699 return error_mark_node;
2703 if (TREE_SIDE_EFFECTS (instance_ptr))
2704 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2706 if (TREE_SIDE_EFFECTS (function))
2707 function = save_expr (function);
2709 /* Start by extracting all the information from the PMF itself. */
2710 e3 = pfn_from_ptrmemfunc (function);
2711 delta = delta_from_ptrmemfunc (function);
2712 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2713 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2715 case ptrmemfunc_vbit_in_pfn:
2716 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node,
2717 tf_warning_or_error);
2718 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node,
2719 tf_warning_or_error);
2722 case ptrmemfunc_vbit_in_delta:
2723 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node,
2724 tf_warning_or_error);
2725 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node,
2726 tf_warning_or_error);
2733 /* Convert down to the right base before using the instance. A
2734 special case is that in a pointer to member of class C, C may
2735 be incomplete. In that case, the function will of course be
2736 a member of C, and no conversion is required. In fact,
2737 lookup_base will fail in that case, because incomplete
2738 classes do not have BINFOs. */
2739 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2740 if (!same_type_ignoring_top_level_qualifiers_p
2741 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2743 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2744 basetype, ba_check, NULL);
2745 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2747 if (instance_ptr == error_mark_node)
2748 return error_mark_node;
2750 /* ...and then the delta in the PMF. */
2751 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
2752 instance_ptr, fold_convert (sizetype, delta));
2754 /* Hand back the adjusted 'this' argument to our caller. */
2755 *instance_ptrptr = instance_ptr;
2757 /* Next extract the vtable pointer from the object. */
2758 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2760 vtbl = cp_build_indirect_ref (vtbl, NULL, tf_warning_or_error);
2762 /* Finally, extract the function pointer from the vtable. */
2763 e2 = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
2764 fold_convert (sizetype, idx));
2765 e2 = cp_build_indirect_ref (e2, NULL, tf_warning_or_error);
2766 TREE_CONSTANT (e2) = 1;
2768 /* When using function descriptors, the address of the
2769 vtable entry is treated as a function pointer. */
2770 if (TARGET_VTABLE_USES_DESCRIPTORS)
2771 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2772 cp_build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1,
2773 tf_warning_or_error));
2775 e2 = fold_convert (TREE_TYPE (e3), e2);
2776 e1 = build_conditional_expr (e1, e2, e3, tf_warning_or_error);
2778 /* Make sure this doesn't get evaluated first inside one of the
2779 branches of the COND_EXPR. */
2780 if (instance_save_expr)
2781 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2782 instance_save_expr, e1);
2789 /* Used by the C-common bits. */
2791 build_function_call (tree function, tree params)
2793 return cp_build_function_call (function, params, tf_warning_or_error);
2797 cp_build_function_call (tree function, tree params, tsubst_flags_t complain)
2799 tree fntype, fndecl;
2800 tree name = NULL_TREE;
2802 tree original = function;
2803 int nargs, parm_types_len;
2807 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2808 expressions, like those used for ObjC messenger dispatches. */
2809 function = objc_rewrite_function_call (function, params);
2811 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2812 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2813 if (TREE_CODE (function) == NOP_EXPR
2814 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2815 function = TREE_OPERAND (function, 0);
2817 if (TREE_CODE (function) == FUNCTION_DECL)
2819 name = DECL_NAME (function);
2821 mark_used (function);
2824 /* Convert anything with function type to a pointer-to-function. */
2825 if (pedantic && DECL_MAIN_P (function) && (complain & tf_error))
2826 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2828 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2829 (because calling an inline function does not mean the function
2830 needs to be separately compiled). */
2832 if (DECL_INLINE (function))
2833 function = inline_conversion (function);
2835 function = build_addr_func (function);
2841 function = build_addr_func (function);
2844 if (function == error_mark_node)
2845 return error_mark_node;
2847 fntype = TREE_TYPE (function);
2849 if (TYPE_PTRMEMFUNC_P (fntype))
2851 if (complain & tf_error)
2852 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2853 "function in %<%E (...)%>",
2855 return error_mark_node;
2858 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2859 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2861 if (!((TREE_CODE (fntype) == POINTER_TYPE
2862 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2864 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2866 if (complain & tf_error)
2867 error ("%qE cannot be used as a function", original);
2868 return error_mark_node;
2871 /* fntype now gets the type of function pointed to. */
2872 fntype = TREE_TYPE (fntype);
2873 parm_types = TYPE_ARG_TYPES (fntype);
2875 /* Allocate storage for converted arguments. */
2876 parm_types_len = list_length (parm_types);
2877 nargs = list_length (params);
2878 if (parm_types_len > nargs)
2879 nargs = parm_types_len;
2880 argarray = (tree *) alloca (nargs * sizeof (tree));
2882 /* Convert the parameters to the types declared in the
2883 function prototype, or apply default promotions. */
2884 nargs = convert_arguments (nargs, argarray, parm_types,
2885 params, fndecl, LOOKUP_NORMAL,
2888 return error_mark_node;
2890 /* Check that arguments to builtin functions match the expectations. */
2892 && DECL_BUILT_IN (fndecl)
2893 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
2894 && !check_builtin_function_arguments (fndecl, nargs, argarray))
2895 return error_mark_node;
2897 /* Check for errors in format strings and inappropriately
2899 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2902 return build_cxx_call (function, nargs, argarray);
2905 /* Convert the actual parameter expressions in the list VALUES
2906 to the types in the list TYPELIST.
2907 If parmdecls is exhausted, or when an element has NULL as its type,
2908 perform the default conversions.
2910 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2912 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2914 This is also where warnings about wrong number of args are generated.
2916 Returns the actual number of arguments processed (which might be less
2917 than NARGS), or -1 on error.
2919 VALUES is a chain of TREE_LIST nodes with the elements of the list
2920 in the TREE_VALUE slots of those nodes.
2922 In C++, unspecified trailing parameters can be filled in with their
2923 default arguments, if such were specified. Do so here. */
2926 convert_arguments (int nargs, tree *argarray,
2927 tree typelist, tree values, tree fndecl, int flags,
2928 tsubst_flags_t complain)
2930 tree typetail, valtail;
2931 const char *called_thing = 0;
2934 /* Argument passing is always copy-initialization. */
2935 flags |= LOOKUP_ONLYCONVERTING;
2939 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2941 if (DECL_NAME (fndecl) == NULL_TREE
2942 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2943 called_thing = "constructor";
2945 called_thing = "member function";
2948 called_thing = "function";
2951 for (valtail = values, typetail = typelist;
2953 valtail = TREE_CHAIN (valtail), i++)
2955 tree type = typetail ? TREE_VALUE (typetail) : 0;
2956 tree val = TREE_VALUE (valtail);
2958 if (val == error_mark_node || type == error_mark_node)
2961 if (type == void_type_node)
2963 if (complain & tf_error)
2967 error ("too many arguments to %s %q+#D",
2968 called_thing, fndecl);
2969 error ("at this point in file");
2972 error ("too many arguments to function");
2979 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2980 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2981 if (TREE_CODE (val) == NOP_EXPR
2982 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2983 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2984 val = TREE_OPERAND (val, 0);
2986 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2988 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2989 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2990 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2991 val = decay_conversion (val);
2994 if (val == error_mark_node)
2999 /* Formal parm type is specified by a function prototype. */
3002 if (!COMPLETE_TYPE_P (complete_type (type)))
3004 if (complain & tf_error)
3007 error ("parameter %P of %qD has incomplete type %qT",
3010 error ("parameter %P has incomplete type %qT", i, type);
3012 parmval = error_mark_node;
3016 parmval = convert_for_initialization
3017 (NULL_TREE, type, val, flags,
3018 "argument passing", fndecl, i, complain);
3019 parmval = convert_for_arg_passing (type, parmval);
3022 if (parmval == error_mark_node)
3025 argarray[i] = parmval;
3029 if (fndecl && DECL_BUILT_IN (fndecl)
3030 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
3031 /* Don't do ellipsis conversion for __built_in_constant_p
3032 as this will result in spurious warnings for non-POD
3034 val = require_complete_type (val);
3036 val = convert_arg_to_ellipsis (val);
3042 typetail = TREE_CHAIN (typetail);
3045 if (typetail != 0 && typetail != void_list_node)
3047 /* See if there are default arguments that can be used. Because
3048 we hold default arguments in the FUNCTION_TYPE (which is so
3049 wrong), we can see default parameters here from deduced
3050 contexts (and via typeof) for indirect function calls.
3051 Fortunately we know whether we have a function decl to
3052 provide default arguments in a language conformant
3054 if (fndecl && TREE_PURPOSE (typetail)
3055 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
3057 for (; typetail != void_list_node; ++i)
3060 = convert_default_arg (TREE_VALUE (typetail),
3061 TREE_PURPOSE (typetail),
3064 if (parmval == error_mark_node)
3067 argarray[i] = parmval;
3068 typetail = TREE_CHAIN (typetail);
3069 /* ends with `...'. */
3070 if (typetail == NULL_TREE)
3076 if (complain & tf_error)
3080 error ("too few arguments to %s %q+#D",
3081 called_thing, fndecl);
3082 error ("at this point in file");
3085 error ("too few arguments to function");
3091 gcc_assert (i <= nargs);
3095 /* Build a binary-operation expression, after performing default
3096 conversions on the operands. CODE is the kind of expression to
3097 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
3098 are the tree codes which correspond to ARG1 and ARG2 when issuing
3099 warnings about possibly misplaced parentheses. They may differ
3100 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
3101 folding (e.g., if the parser sees "a | 1 + 1", it may call this
3102 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
3103 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
3104 ARG2_CODE as ERROR_MARK. */
3107 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
3108 tree arg2, enum tree_code arg2_code, bool *overloaded_p,
3109 tsubst_flags_t complain)
3118 if (processing_template_decl)
3120 if (type_dependent_expression_p (arg1)
3121 || type_dependent_expression_p (arg2))
3122 return build_min_nt (code, arg1, arg2);
3123 arg1 = build_non_dependent_expr (arg1);
3124 arg2 = build_non_dependent_expr (arg2);
3127 if (code == DOTSTAR_EXPR)
3128 expr = build_m_component_ref (arg1, arg2);
3130 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3131 overloaded_p, complain);
3133 /* Check for cases such as x+y<<z which users are likely to
3134 misinterpret. But don't warn about obj << x + y, since that is a
3135 common idiom for I/O. */
3136 if (warn_parentheses
3137 && !processing_template_decl
3138 && !error_operand_p (arg1)
3139 && !error_operand_p (arg2)
3140 && (code != LSHIFT_EXPR
3141 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
3142 warn_about_parentheses (code, arg1_code, arg2_code);
3144 if (processing_template_decl && expr != error_mark_node)
3145 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
3150 /* For the c-common bits. */
3152 build_binary_op (enum tree_code code, tree op0, tree op1,
3153 int convert_p ATTRIBUTE_UNUSED)
3155 return cp_build_binary_op(code, op0, op1, tf_warning_or_error);
3159 /* Build a binary-operation expression without default conversions.
3160 CODE is the kind of expression to build.
3161 This function differs from `build' in several ways:
3162 the data type of the result is computed and recorded in it,
3163 warnings are generated if arg data types are invalid,
3164 special handling for addition and subtraction of pointers is known,
3165 and some optimization is done (operations on narrow ints
3166 are done in the narrower type when that gives the same result).
3167 Constant folding is also done before the result is returned.
3169 Note that the operands will never have enumeral types
3170 because either they have just had the default conversions performed
3171 or they have both just been converted to some other type in which
3172 the arithmetic is to be done.
3174 C++: must do special pointer arithmetic when implementing
3175 multiple inheritance, and deal with pointer to member functions. */
3178 cp_build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3179 tsubst_flags_t complain)
3182 enum tree_code code0, code1;
3184 const char *invalid_op_diag;
3186 /* Expression code to give to the expression when it is built.
3187 Normally this is CODE, which is what the caller asked for,
3188 but in some special cases we change it. */
3189 enum tree_code resultcode = code;
3191 /* Data type in which the computation is to be performed.
3192 In the simplest cases this is the common type of the arguments. */
3193 tree result_type = NULL;
3195 /* Nonzero means operands have already been type-converted
3196 in whatever way is necessary.
3197 Zero means they need to be converted to RESULT_TYPE. */
3200 /* Nonzero means create the expression with this type, rather than
3202 tree build_type = 0;
3204 /* Nonzero means after finally constructing the expression
3205 convert it to this type. */
3206 tree final_type = 0;
3210 /* Nonzero if this is an operation like MIN or MAX which can
3211 safely be computed in short if both args are promoted shorts.
3212 Also implies COMMON.
3213 -1 indicates a bitwise operation; this makes a difference
3214 in the exact conditions for when it is safe to do the operation
3215 in a narrower mode. */
3218 /* Nonzero if this is a comparison operation;
3219 if both args are promoted shorts, compare the original shorts.
3220 Also implies COMMON. */
3221 int short_compare = 0;
3223 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3226 /* True if both operands have arithmetic type. */
3227 bool arithmetic_types_p;
3229 /* Apply default conversions. */
3233 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3234 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3235 || code == TRUTH_XOR_EXPR)
3237 if (!really_overloaded_fn (op0))
3238 op0 = decay_conversion (op0);
3239 if (!really_overloaded_fn (op1))
3240 op1 = decay_conversion (op1);
3244 if (!really_overloaded_fn (op0))
3245 op0 = default_conversion (op0);
3246 if (!really_overloaded_fn (op1))
3247 op1 = default_conversion (op1);
3250 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3251 STRIP_TYPE_NOPS (op0);
3252 STRIP_TYPE_NOPS (op1);
3254 /* DTRT if one side is an overloaded function, but complain about it. */
3255 if (type_unknown_p (op0))
3257 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3258 if (t != error_mark_node)
3260 if (complain & tf_error)
3261 permerror ("assuming cast to type %qT from overloaded function",
3266 if (type_unknown_p (op1))
3268 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3269 if (t != error_mark_node)
3271 if (complain & tf_error)
3272 permerror ("assuming cast to type %qT from overloaded function",
3278 type0 = TREE_TYPE (op0);
3279 type1 = TREE_TYPE (op1);
3281 /* The expression codes of the data types of the arguments tell us
3282 whether the arguments are integers, floating, pointers, etc. */
3283 code0 = TREE_CODE (type0);
3284 code1 = TREE_CODE (type1);
3286 /* If an error was already reported for one of the arguments,
3287 avoid reporting another error. */
3289 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3290 return error_mark_node;
3292 if ((invalid_op_diag
3293 = targetm.invalid_binary_op (code, type0, type1)))
3295 error (invalid_op_diag);
3296 return error_mark_node;
3302 /* Subtraction of two similar pointers.
3303 We must subtract them as integers, then divide by object size. */
3304 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3305 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3307 return pointer_diff (op0, op1, common_type (type0, type1));
3308 /* In all other cases except pointer - int, the usual arithmetic
3310 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3315 /* The pointer - int case is just like pointer + int; fall
3318 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3319 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3323 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3324 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3325 if (processing_template_decl)
3327 result_type = TREE_TYPE (ptr_operand);
3330 return cp_pointer_int_sum (code,
3341 case TRUNC_DIV_EXPR:
3343 case FLOOR_DIV_EXPR:
3344 case ROUND_DIV_EXPR:
3345 case EXACT_DIV_EXPR:
3346 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3347 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3348 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3349 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3351 enum tree_code tcode0 = code0, tcode1 = code1;
3353 warn_for_div_by_zero (op1);
3355 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3356 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3357 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3358 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3360 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3361 resultcode = RDIV_EXPR;
3363 /* When dividing two signed integers, we have to promote to int.
3364 unless we divide by a constant != -1. Note that default
3365 conversion will have been performed on the operands at this
3366 point, so we have to dig out the original type to find out if
3368 shorten = ((TREE_CODE (op0) == NOP_EXPR
3369 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3370 || (TREE_CODE (op1) == INTEGER_CST
3371 && ! integer_all_onesp (op1)));
3380 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3381 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3382 && !VECTOR_FLOAT_TYPE_P (type0)
3383 && !VECTOR_FLOAT_TYPE_P (type1)))
3387 case TRUNC_MOD_EXPR:
3388 case FLOOR_MOD_EXPR:
3389 warn_for_div_by_zero (op1);
3391 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3393 /* Although it would be tempting to shorten always here, that loses
3394 on some targets, since the modulo instruction is undefined if the
3395 quotient can't be represented in the computation mode. We shorten
3396 only if unsigned or if dividing by something we know != -1. */
3397 shorten = ((TREE_CODE (op0) == NOP_EXPR
3398 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3399 || (TREE_CODE (op1) == INTEGER_CST
3400 && ! integer_all_onesp (op1)));
3405 case TRUTH_ANDIF_EXPR:
3406 case TRUTH_ORIF_EXPR:
3407 case TRUTH_AND_EXPR:
3409 result_type = boolean_type_node;
3412 /* Shift operations: result has same type as first operand;
3413 always convert second operand to int.
3414 Also set SHORT_SHIFT if shifting rightward. */
3417 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3419 result_type = type0;
3420 if (TREE_CODE (op1) == INTEGER_CST)
3422 if (tree_int_cst_lt (op1, integer_zero_node))
3424 if (complain & tf_warning)
3425 warning (0, "right shift count is negative");
3429 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0
3430 && (complain & tf_warning))
3431 warning (0, "right shift count >= width of type");
3434 /* Convert the shift-count to an integer, regardless of
3435 size of value being shifted. */
3436 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3437 op1 = cp_convert (integer_type_node, op1);
3438 /* Avoid converting op1 to result_type later. */
3444 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3446 result_type = type0;
3447 if (TREE_CODE (op1) == INTEGER_CST)
3449 if (tree_int_cst_lt (op1, integer_zero_node))
3451 if (complain & tf_warning)
3452 warning (0, "left shift count is negative");
3454 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3456 if (complain & tf_warning)
3457 warning (0, "left shift count >= width of type");
3460 /* Convert the shift-count to an integer, regardless of
3461 size of value being shifted. */
3462 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3463 op1 = cp_convert (integer_type_node, op1);
3464 /* Avoid converting op1 to result_type later. */
3471 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3473 result_type = type0;
3474 if (TREE_CODE (op1) == INTEGER_CST)
3476 if (tree_int_cst_lt (op1, integer_zero_node))
3478 if (complain & tf_warning)
3479 warning (0, (code == LROTATE_EXPR)
3480 ? G_("left rotate count is negative")
3481 : G_("right rotate count is negative"));
3483 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3485 if (complain & tf_warning)
3486 warning (0, (code == LROTATE_EXPR)
3487 ? G_("left rotate count >= width of type")
3488 : G_("right rotate count >= width of type"));
3491 /* Convert the shift-count to an integer, regardless of
3492 size of value being shifted. */
3493 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3494 op1 = cp_convert (integer_type_node, op1);
3500 if ((complain & tf_warning)
3501 && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1)))
3502 warning (OPT_Wfloat_equal,
3503 "comparing floating point with == or != is unsafe");
3504 if ((complain & tf_warning)
3505 && ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3506 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0))))
3507 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3509 build_type = boolean_type_node;
3510 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3511 || code0 == COMPLEX_TYPE)
3512 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3513 || code1 == COMPLEX_TYPE))
3515 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3516 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3517 result_type = composite_pointer_type (type0, type1, op0, op1,
3518 "comparison", complain);
3519 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3520 && null_ptr_cst_p (op1))
3522 if (TREE_CODE (op0) == ADDR_EXPR
3523 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3525 if (complain & tf_warning)
3526 warning (OPT_Waddress, "the address of %qD will never be NULL",
3527 TREE_OPERAND (op0, 0));
3529 result_type = type0;
3531 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3532 && null_ptr_cst_p (op0))
3534 if (TREE_CODE (op1) == ADDR_EXPR
3535 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3537 if (complain & tf_warning)
3538 warning (OPT_Waddress, "the address of %qD will never be NULL",
3539 TREE_OPERAND (op1, 0));
3541 result_type = type1;
3543 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3545 result_type = type0;
3546 if (complain & tf_error)
3547 permerror ("ISO C++ forbids comparison between pointer and integer");
3549 return error_mark_node;
3551 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3553 result_type = type1;
3554 if (complain & tf_error)
3555 permerror ("ISO C++ forbids comparison between pointer and integer");
3557 return error_mark_node;
3559 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3561 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3562 == ptrmemfunc_vbit_in_delta)
3564 tree pfn0 = pfn_from_ptrmemfunc (op0);
3565 tree delta0 = delta_from_ptrmemfunc (op0);
3566 tree e1 = cp_build_binary_op (EQ_EXPR,
3568 fold_convert (TREE_TYPE (pfn0),
3571 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3575 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3577 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2,
3579 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3583 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3584 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3586 result_type = TREE_TYPE (op0);
3588 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3589 return cp_build_binary_op (code, op1, op0, complain);
3590 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1))
3593 /* E will be the final comparison. */
3595 /* E1 and E2 are for scratch. */
3603 type = composite_pointer_type (type0, type1, op0, op1, "comparison",
3606 if (!same_type_p (TREE_TYPE (op0), type))
3607 op0 = cp_convert_and_check (type, op0);
3608 if (!same_type_p (TREE_TYPE (op1), type))
3609 op1 = cp_convert_and_check (type, op1);
3611 if (op0 == error_mark_node || op1 == error_mark_node)
3612 return error_mark_node;
3614 if (TREE_SIDE_EFFECTS (op0))
3615 op0 = save_expr (op0);
3616 if (TREE_SIDE_EFFECTS (op1))
3617 op1 = save_expr (op1);
3619 pfn0 = pfn_from_ptrmemfunc (op0);
3620 pfn1 = pfn_from_ptrmemfunc (op1);
3621 delta0 = delta_from_ptrmemfunc (op0);
3622 delta1 = delta_from_ptrmemfunc (op1);
3623 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3624 == ptrmemfunc_vbit_in_delta)
3629 && ((op0.delta == op1.delta)
3630 || (!op0.pfn && op0.delta & 1 == 0
3631 && op1.delta & 1 == 0))
3633 The reason for the `!op0.pfn' bit is that a NULL
3634 pointer-to-member is any member with a zero PFN and
3635 LSB of the DELTA field is 0. */
3637 e1 = cp_build_binary_op (BIT_AND_EXPR,
3641 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node,
3643 e2 = cp_build_binary_op (BIT_AND_EXPR,
3647 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3649 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1,
3651 e2 = cp_build_binary_op (EQ_EXPR,
3653 fold_convert (TREE_TYPE (pfn0),
3656 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3657 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3658 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3665 && (!op0.pfn || op0.delta == op1.delta))
3667 The reason for the `!op0.pfn' bit is that a NULL
3668 pointer-to-member is any member with a zero PFN; the
3669 DELTA field is unspecified. */
3671 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3672 e2 = cp_build_binary_op (EQ_EXPR,
3674 fold_convert (TREE_TYPE (pfn0),
3677 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3679 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3680 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3681 if (code == EQ_EXPR)
3683 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node, complain);
3687 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3688 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3690 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3691 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3699 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3700 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3702 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3703 result_type = composite_pointer_type (type0, type1, op0, op1,
3704 "comparison", complain);
3711 if (TREE_CODE (orig_op0) == STRING_CST
3712 || TREE_CODE (orig_op1) == STRING_CST)
3714 if (complain & tf_warning)
3715 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3718 build_type = boolean_type_node;
3719 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3720 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3722 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3723 result_type = composite_pointer_type (type0, type1, op0, op1,
3724 "comparison", complain);
3725 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3726 && integer_zerop (op1))
3727 result_type = type0;
3728 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3729 && integer_zerop (op0))
3730 result_type = type1;
3731 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3733 result_type = type0;
3734 if (complain & tf_error)
3735 permerror ("ISO C++ forbids comparison between pointer and integer");
3737 return error_mark_node;
3739 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3741 result_type = type1;
3742 if (complain & tf_error)
3743 permerror ("ISO C++ forbids comparison between pointer and integer");
3745 return error_mark_node;
3749 case UNORDERED_EXPR:
3756 build_type = integer_type_node;
3757 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3759 if (complain & tf_error)
3760 error ("unordered comparison on non-floating point argument");
3761 return error_mark_node;
3770 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3771 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3772 || code1 == COMPLEX_TYPE)))
3773 arithmetic_types_p = 1;
3776 arithmetic_types_p = 0;
3777 /* Vector arithmetic is only allowed when both sides are vectors. */
3778 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3780 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3781 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3784 binary_op_error (code, type0, type1);
3785 return error_mark_node;
3787 arithmetic_types_p = 1;
3790 /* Determine the RESULT_TYPE, if it is not already known. */
3792 && arithmetic_types_p
3793 && (shorten || common || short_compare))
3794 result_type = common_type (type0, type1);
3798 if (complain & tf_error)
3799 error ("invalid operands of types %qT and %qT to binary %qO",
3800 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3801 return error_mark_node;
3804 /* If we're in a template, the only thing we need to know is the
3806 if (processing_template_decl)
3808 /* Since the middle-end checks the type when doing a build2, we
3809 need to build the tree in pieces. This built tree will never
3810 get out of the front-end as we replace it when instantiating
3812 tree tmp = build2 (resultcode,
3813 build_type ? build_type : result_type,
3815 TREE_OPERAND (tmp, 0) = op0;
3819 if (arithmetic_types_p)
3821 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3823 /* For certain operations (which identify themselves by shorten != 0)
3824 if both args were extended from the same smaller type,
3825 do the arithmetic in that type and then extend.
3827 shorten !=0 and !=1 indicates a bitwise operation.
3828 For them, this optimization is safe only if
3829 both args are zero-extended or both are sign-extended.
3830 Otherwise, we might change the result.
3831 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3832 but calculated in (unsigned short) it would be (unsigned short)-1. */
3834 if (shorten && none_complex)
3836 int unsigned0, unsigned1;
3837 tree arg0 = get_narrower (op0, &unsigned0);
3838 tree arg1 = get_narrower (op1, &unsigned1);
3839 /* UNS is 1 if the operation to be done is an unsigned one. */
3840 int uns = TYPE_UNSIGNED (result_type);
3843 final_type = result_type;
3845 /* Handle the case that OP0 does not *contain* a conversion
3846 but it *requires* conversion to FINAL_TYPE. */
3848 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3849 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3850 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3851 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3853 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3855 /* For bitwise operations, signedness of nominal type
3856 does not matter. Consider only how operands were extended. */
3860 /* Note that in all three cases below we refrain from optimizing
3861 an unsigned operation on sign-extended args.
3862 That would not be valid. */
3864 /* Both args variable: if both extended in same way
3865 from same width, do it in that width.
3866 Do it unsigned if args were zero-extended. */
3867 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3868 < TYPE_PRECISION (result_type))
3869 && (TYPE_PRECISION (TREE_TYPE (arg1))
3870 == TYPE_PRECISION (TREE_TYPE (arg0)))
3871 && unsigned0 == unsigned1
3872 && (unsigned0 || !uns))
3873 result_type = c_common_signed_or_unsigned_type
3874 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3875 else if (TREE_CODE (arg0) == INTEGER_CST
3876 && (unsigned1 || !uns)
3877 && (TYPE_PRECISION (TREE_TYPE (arg1))
3878 < TYPE_PRECISION (result_type))
3879 && (type = c_common_signed_or_unsigned_type
3880 (unsigned1, TREE_TYPE (arg1)),
3881 int_fits_type_p (arg0, type)))
3883 else if (TREE_CODE (arg1) == INTEGER_CST
3884 && (unsigned0 || !uns)
3885 && (TYPE_PRECISION (TREE_TYPE (arg0))
3886 < TYPE_PRECISION (result_type))
3887 && (type = c_common_signed_or_unsigned_type
3888 (unsigned0, TREE_TYPE (arg0)),
3889 int_fits_type_p (arg1, type)))
3893 /* Comparison operations are shortened too but differently.
3894 They identify themselves by setting short_compare = 1. */
3898 /* Don't write &op0, etc., because that would prevent op0
3899 from being kept in a register.
3900 Instead, make copies of the our local variables and
3901 pass the copies by reference, then copy them back afterward. */
3902 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3903 enum tree_code xresultcode = resultcode;
3905 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3907 return cp_convert (boolean_type_node, val);
3908 op0 = xop0, op1 = xop1;
3910 resultcode = xresultcode;
3913 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3914 && warn_sign_compare
3915 /* Do not warn until the template is instantiated; we cannot
3916 bound the ranges of the arguments until that point. */
3917 && !processing_template_decl)
3919 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3920 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3922 int unsignedp0, unsignedp1;
3923 tree primop0 = get_narrower (op0, &unsignedp0);
3924 tree primop1 = get_narrower (op1, &unsignedp1);
3926 /* Check for comparison of different enum types. */
3927 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3928 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3929 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3930 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1))
3931 && (complain & tf_warning))
3933 warning (OPT_Wsign_compare, "comparison between types %q#T and %q#T",
3934 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3937 /* Give warnings for comparisons between signed and unsigned
3938 quantities that may fail. */
3939 /* Do the checking based on the original operand trees, so that
3940 casts will be considered, but default promotions won't be. */
3942 /* Do not warn if the comparison is being done in a signed type,
3943 since the signed type will only be chosen if it can represent
3944 all the values of the unsigned type. */
3945 if (!TYPE_UNSIGNED (result_type))
3947 /* Do not warn if both operands are unsigned. */
3948 else if (op0_signed == op1_signed)
3950 /* Do not warn if the signed quantity is an unsuffixed
3951 integer literal (or some static constant expression
3952 involving such literals or a conditional expression
3953 involving such literals) and it is non-negative. */
3954 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3955 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3957 /* Do not warn if the comparison is an equality operation,
3958 the unsigned quantity is an integral constant and it does
3959 not use the most significant bit of result_type. */
3960 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3961 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3962 && int_fits_type_p (orig_op1, c_common_signed_type
3964 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3965 && int_fits_type_p (orig_op0, c_common_signed_type
3968 else if (complain & tf_warning)
3969 warning (OPT_Wsign_compare,
3970 "comparison between signed and unsigned integer expressions");
3972 /* Warn if two unsigned values are being compared in a size
3973 larger than their original size, and one (and only one) is the
3974 result of a `~' operator. This comparison will always fail.
3976 Also warn if one operand is a constant, and the constant does not
3977 have all bits set that are set in the ~ operand when it is
3980 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3981 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3983 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3984 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3985 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3986 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3988 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3991 HOST_WIDE_INT constant, mask;
3995 if (host_integerp (primop0, 0))
3998 unsignedp = unsignedp1;
3999 constant = tree_low_cst (primop0, 0);
4004 unsignedp = unsignedp0;
4005 constant = tree_low_cst (primop1, 0);
4008 bits = TYPE_PRECISION (TREE_TYPE (primop));
4009 if (bits < TYPE_PRECISION (result_type)
4010 && bits < HOST_BITS_PER_LONG && unsignedp)
4012 mask = (~ (HOST_WIDE_INT) 0) << bits;
4013 if ((mask & constant) != mask
4014 && (complain & tf_warning))
4015 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with constant");
4018 else if (unsignedp0 && unsignedp1
4019 && (TYPE_PRECISION (TREE_TYPE (primop0))
4020 < TYPE_PRECISION (result_type))
4021 && (TYPE_PRECISION (TREE_TYPE (primop1))
4022 < TYPE_PRECISION (result_type))
4023 && (complain & tf_warning))
4024 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with unsigned");
4029 /* Issue warnings about peculiar, but valid, uses of NULL. */
4030 if ((orig_op0 == null_node || orig_op1 == null_node)
4031 /* It's reasonable to use pointer values as operands of &&
4032 and ||, so NULL is no exception. */
4033 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
4034 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
4035 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
4036 && code != EQ_EXPR && code != NE_EXPR)
4037 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
4038 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
4039 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE))
4040 && (complain & tf_warning))
4041 /* Some sort of arithmetic operation involving NULL was
4042 performed. Note that pointer-difference and pointer-addition
4043 have already been handled above, and so we don't end up here in
4045 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
4048 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
4049 Then the expression will be built.
4050 It will be given type FINAL_TYPE if that is nonzero;
4051 otherwise, it will be given type RESULT_TYPE. */
4054 if (TREE_TYPE (op0) != result_type)
4055 op0 = cp_convert_and_check (result_type, op0);
4056 if (TREE_TYPE (op1) != result_type)
4057 op1 = cp_convert_and_check (result_type, op1);
4059 if (op0 == error_mark_node || op1 == error_mark_node)
4060 return error_mark_node;
4063 if (build_type == NULL_TREE)
4064 build_type = result_type;
4066 result = build2 (resultcode, build_type, op0, op1);
4067 result = fold_if_not_in_template (result);
4068 if (final_type != 0)
4069 result = cp_convert (final_type, result);
4071 if (TREE_OVERFLOW_P (result)
4072 && !TREE_OVERFLOW_P (op0)
4073 && !TREE_OVERFLOW_P (op1))
4074 overflow_warning (result);
4079 /* Return a tree for the sum or difference (RESULTCODE says which)
4080 of pointer PTROP and integer INTOP. */
4083 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
4085 tree res_type = TREE_TYPE (ptrop);
4087 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
4088 in certain circumstance (when it's valid to do so). So we need
4089 to make sure it's complete. We don't need to check here, if we
4090 can actually complete it at all, as those checks will be done in
4091 pointer_int_sum() anyway. */
4092 complete_type (TREE_TYPE (res_type));
4094 return pointer_int_sum (resultcode, ptrop,
4095 fold_if_not_in_template (intop));
4098 /* Return a tree for the difference of pointers OP0 and OP1.
4099 The resulting tree has type int. */
4102 pointer_diff (tree op0, tree op1, tree ptrtype)
4105 tree restype = ptrdiff_type_node;
4106 tree target_type = TREE_TYPE (ptrtype);
4108 if (!complete_type_or_else (target_type, NULL_TREE))
4109 return error_mark_node;
4111 if (pedantic || warn_pointer_arith)
4113 if (TREE_CODE (target_type) == VOID_TYPE)
4114 permerror ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
4115 if (TREE_CODE (target_type) == FUNCTION_TYPE)
4116 permerror ("ISO C++ forbids using pointer to a function in subtraction");
4117 if (TREE_CODE (target_type) == METHOD_TYPE)
4118 permerror ("ISO C++ forbids using pointer to a method in subtraction");
4121 /* First do the subtraction as integers;
4122 then drop through to build the divide operator. */
4124 op0 = cp_build_binary_op (MINUS_EXPR,
4125 cp_convert (restype, op0),
4126 cp_convert (restype, op1),
4127 tf_warning_or_error);
4129 /* This generates an error if op1 is a pointer to an incomplete type. */
4130 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
4131 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
4133 op1 = (TYPE_PTROB_P (ptrtype)
4134 ? size_in_bytes (target_type)
4135 : integer_one_node);
4137 /* Do the division. */
4139 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
4140 return fold_if_not_in_template (result);
4143 /* Construct and perhaps optimize a tree representation
4144 for a unary operation. CODE, a tree_code, specifies the operation
4145 and XARG is the operand. */
4148 build_x_unary_op (enum tree_code code, tree xarg, tsubst_flags_t complain)
4150 tree orig_expr = xarg;
4154 if (processing_template_decl)
4156 if (type_dependent_expression_p (xarg))
4157 return build_min_nt (code, xarg, NULL_TREE);
4159 xarg = build_non_dependent_expr (xarg);
4164 /* [expr.unary.op] says:
4166 The address of an object of incomplete type can be taken.
4168 (And is just the ordinary address operator, not an overloaded
4169 "operator &".) However, if the type is a template
4170 specialization, we must complete the type at this point so that
4171 an overloaded "operator &" will be available if required. */
4172 if (code == ADDR_EXPR
4173 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
4174 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
4175 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
4176 || (TREE_CODE (xarg) == OFFSET_REF)))
4177 /* Don't look for a function. */;
4179 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
4180 /*overloaded_p=*/NULL, complain);
4181 if (!exp && code == ADDR_EXPR)
4183 /* A pointer to member-function can be formed only by saying
4185 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
4186 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
4188 if (TREE_CODE (xarg) != OFFSET_REF
4189 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4191 error ("invalid use of %qE to form a pointer-to-member-function",
4193 if (TREE_CODE (xarg) != OFFSET_REF)
4194 inform (" a qualified-id is required");
4195 return error_mark_node;
4199 error ("parentheses around %qE cannot be used to form a"
4200 " pointer-to-member-function",
4202 PTRMEM_OK_P (xarg) = 1;
4206 if (TREE_CODE (xarg) == OFFSET_REF)
4208 ptrmem = PTRMEM_OK_P (xarg);
4210 if (!ptrmem && !flag_ms_extensions
4211 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4213 /* A single non-static member, make sure we don't allow a
4214 pointer-to-member. */
4215 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4216 TREE_OPERAND (xarg, 0),
4217 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4218 PTRMEM_OK_P (xarg) = ptrmem;
4221 else if (TREE_CODE (xarg) == TARGET_EXPR && (complain & tf_warning))
4222 warning (0, "taking address of temporary");
4223 exp = cp_build_unary_op (ADDR_EXPR, xarg, 0, complain);
4226 if (processing_template_decl && exp != error_mark_node)
4227 exp = build_min_non_dep (code, exp, orig_expr,
4228 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4229 if (TREE_CODE (exp) == ADDR_EXPR)
4230 PTRMEM_OK_P (exp) = ptrmem;
4234 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4235 constants, where a null value is represented by an INTEGER_CST of
4239 cp_truthvalue_conversion (tree expr)
4241 tree type = TREE_TYPE (expr);
4242 if (TYPE_PTRMEM_P (type))
4243 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4245 return c_common_truthvalue_conversion (expr);
4248 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4251 condition_conversion (tree expr)
4254 if (processing_template_decl)
4256 t = perform_implicit_conversion (boolean_type_node, expr,
4257 tf_warning_or_error);
4258 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4262 /* Return an ADDR_EXPR giving the address of T. This function
4263 attempts no optimizations or simplifications; it is a low-level
4267 build_address (tree t)
4271 if (error_operand_p (t) || !cxx_mark_addressable (t))
4272 return error_mark_node;
4274 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4279 /* Return a NOP_EXPR converting EXPR to TYPE. */
4282 build_nop (tree type, tree expr)
4284 if (type == error_mark_node || error_operand_p (expr))
4286 return build1 (NOP_EXPR, type, expr);
4289 /* C++: Must handle pointers to members.
4291 Perhaps type instantiation should be extended to handle conversion
4292 from aggregates to types we don't yet know we want? (Or are those
4293 cases typically errors which should be reported?)
4295 NOCONVERT nonzero suppresses the default promotions
4296 (such as from short to int). */
4299 cp_build_unary_op (enum tree_code code, tree xarg, int noconvert,
4300 tsubst_flags_t complain)
4302 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4305 const char *errstring = NULL;
4307 const char *invalid_op_diag;
4309 if (arg == error_mark_node)
4310 return error_mark_node;
4312 if ((invalid_op_diag
4313 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4318 error (invalid_op_diag);
4319 return error_mark_node;
4324 case UNARY_PLUS_EXPR:
4327 int flags = WANT_ARITH | WANT_ENUM;
4328 /* Unary plus (but not unary minus) is allowed on pointers. */
4329 if (code == UNARY_PLUS_EXPR)
4330 flags |= WANT_POINTER;
4331 arg = build_expr_type_conversion (flags, arg, true);
4333 errstring = (code == NEGATE_EXPR
4334 ? "wrong type argument to unary minus"
4335 : "wrong type argument to unary plus");
4338 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4339 arg = perform_integral_promotions (arg);
4341 /* Make sure the result is not an lvalue: a unary plus or minus
4342 expression is always a rvalue. */
4349 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4353 arg = default_conversion (arg);
4355 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4358 errstring = "wrong type argument to bit-complement";
4359 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4360 arg = perform_integral_promotions (arg);
4364 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4365 errstring = "wrong type argument to abs";
4366 else if (!noconvert)
4367 arg = default_conversion (arg);
4371 /* Conjugating a real value is a no-op, but allow it anyway. */
4372 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4373 errstring = "wrong type argument to conjugation";
4374 else if (!noconvert)
4375 arg = default_conversion (arg);
4378 case TRUTH_NOT_EXPR:
4379 arg = perform_implicit_conversion (boolean_type_node, arg,
4381 val = invert_truthvalue (arg);
4382 if (arg != error_mark_node)
4384 errstring = "in argument to unary !";
4391 if (TREE_CODE (arg) == COMPLEX_CST)
4392 return TREE_REALPART (arg);
4393 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4395 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4396 return fold_if_not_in_template (arg);
4402 if (TREE_CODE (arg) == COMPLEX_CST)
4403 return TREE_IMAGPART (arg);
4404 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4406 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4407 return fold_if_not_in_template (arg);
4410 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4412 case PREINCREMENT_EXPR:
4413 case POSTINCREMENT_EXPR:
4414 case PREDECREMENT_EXPR:
4415 case POSTDECREMENT_EXPR:
4416 /* Handle complex lvalues (when permitted)
4417 by reduction to simpler cases. */
4419 val = unary_complex_lvalue (code, arg);
4423 /* Increment or decrement the real part of the value,
4424 and don't change the imaginary part. */
4425 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4429 arg = stabilize_reference (arg);
4430 real = cp_build_unary_op (REALPART_EXPR, arg, 1, complain);
4431 imag = cp_build_unary_op (IMAGPART_EXPR, arg, 1, complain);
4432 real = cp_build_unary_op (code, real, 1, complain);
4433 if (real == error_mark_node || imag == error_mark_node)
4434 return error_mark_node;
4435 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4439 /* Report invalid types. */
4441 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4444 if (code == PREINCREMENT_EXPR)
4445 errstring ="no pre-increment operator for type";
4446 else if (code == POSTINCREMENT_EXPR)
4447 errstring ="no post-increment operator for type";
4448 else if (code == PREDECREMENT_EXPR)
4449 errstring ="no pre-decrement operator for type";
4451 errstring ="no post-decrement operator for type";
4454 else if (arg == error_mark_node)
4455 return error_mark_node;
4457 /* Report something read-only. */
4459 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4460 || TREE_READONLY (arg))
4462 if (complain & tf_error)
4463 readonly_error (arg, ((code == PREINCREMENT_EXPR
4464 || code == POSTINCREMENT_EXPR)
4465 ? "increment" : "decrement"));
4467 return error_mark_node;
4473 tree result_type = TREE_TYPE (arg);
4475 declared_type = unlowered_expr_type (arg);
4477 arg = get_unwidened (arg, 0);
4478 argtype = TREE_TYPE (arg);
4480 /* ARM $5.2.5 last annotation says this should be forbidden. */
4481 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4483 if (complain & tf_error)
4484 permerror ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4485 ? G_("ISO C++ forbids incrementing an enum")
4486 : G_("ISO C++ forbids decrementing an enum"));
4488 return error_mark_node;
4491 /* Compute the increment. */
4493 if (TREE_CODE (argtype) == POINTER_TYPE)
4495 tree type = complete_type (TREE_TYPE (argtype));
4497 if (!COMPLETE_OR_VOID_TYPE_P (type))
4499 if (complain & tf_error)
4500 error (((code == PREINCREMENT_EXPR
4501 || code == POSTINCREMENT_EXPR))
4502 ? G_("cannot increment a pointer to incomplete type %qT")
4503 : G_("cannot decrement a pointer to incomplete type %qT"),
4504 TREE_TYPE (argtype));
4506 return error_mark_node;
4508 else if ((pedantic || warn_pointer_arith)
4509 && !TYPE_PTROB_P (argtype))
4511 if (complain & tf_error)
4512 permerror ((code == PREINCREMENT_EXPR
4513 || code == POSTINCREMENT_EXPR)
4514 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4515 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4518 return error_mark_node;
4521 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4524 inc = integer_one_node;
4526 inc = cp_convert (argtype, inc);
4528 /* Complain about anything else that is not a true lvalue. */
4529 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4530 || code == POSTINCREMENT_EXPR)
4531 ? lv_increment : lv_decrement),
4533 return error_mark_node;
4535 /* Forbid using -- on `bool'. */
4536 if (same_type_p (declared_type, boolean_type_node))
4538 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4540 if (complain & tf_error)
4541 error ("invalid use of Boolean expression as operand "
4542 "to %<operator--%>");
4543 return error_mark_node;
4545 val = boolean_increment (code, arg);
4548 val = build2 (code, TREE_TYPE (arg), arg, inc);
4550 TREE_SIDE_EFFECTS (val) = 1;
4551 return cp_convert (result_type, val);
4555 /* Note that this operation never does default_conversion
4556 regardless of NOCONVERT. */
4558 argtype = lvalue_type (arg);
4560 if (TREE_CODE (arg) == OFFSET_REF)
4563 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4565 tree type = build_pointer_type (TREE_TYPE (argtype));
4566 arg = build1 (CONVERT_EXPR, type, arg);
4569 else if (pedantic && DECL_MAIN_P (arg))
4572 if (complain & tf_error)
4573 permerror ("ISO C++ forbids taking address of function %<::main%>");
4575 return error_mark_node;
4578 /* Let &* cancel out to simplify resulting code. */
4579 if (TREE_CODE (arg) == INDIRECT_REF)
4581 /* We don't need to have `current_class_ptr' wrapped in a
4582 NON_LVALUE_EXPR node. */
4583 if (arg == current_class_ref)
4584 return current_class_ptr;
4586 arg = TREE_OPERAND (arg, 0);
4587 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4589 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4590 arg = build1 (CONVERT_EXPR, type, arg);
4593 /* Don't let this be an lvalue. */
4598 /* Uninstantiated types are all functions. Taking the
4599 address of a function is a no-op, so just return the
4602 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4603 || !IDENTIFIER_OPNAME_P (arg));
4605 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4606 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4608 /* They're trying to take the address of a unique non-static
4609 member function. This is ill-formed (except in MS-land),
4610 but let's try to DTRT.
4611 Note: We only handle unique functions here because we don't
4612 want to complain if there's a static overload; non-unique
4613 cases will be handled by instantiate_type. But we need to
4614 handle this case here to allow casts on the resulting PMF.
4615 We could defer this in non-MS mode, but it's easier to give
4616 a useful error here. */
4618 /* Inside constant member functions, the `this' pointer
4619 contains an extra const qualifier. TYPE_MAIN_VARIANT
4620 is used here to remove this const from the diagnostics
4621 and the created OFFSET_REF. */
4622 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4623 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4626 if (! flag_ms_extensions)
4628 tree name = DECL_NAME (fn);
4629 if (!(complain & tf_error))
4630 return error_mark_node;
4631 else if (current_class_type
4632 && TREE_OPERAND (arg, 0) == current_class_ref)
4633 /* An expression like &memfn. */
4634 permerror ("ISO C++ forbids taking the address of an unqualified"
4635 " or parenthesized non-static member function to form"
4636 " a pointer to member function. Say %<&%T::%D%>",
4639 permerror ("ISO C++ forbids taking the address of a bound member"
4640 " function to form a pointer to member function."
4644 arg = build_offset_ref (base, fn, /*address_p=*/true);
4648 if (type_unknown_p (arg))
4649 return build1 (ADDR_EXPR, unknown_type_node, arg);
4651 /* Handle complex lvalues (when permitted)
4652 by reduction to simpler cases. */
4653 val = unary_complex_lvalue (code, arg);
4657 switch (TREE_CODE (arg))
4661 case FIX_TRUNC_EXPR:
4662 /* Even if we're not being pedantic, we cannot allow this
4663 extension when we're instantiating in a SFINAE
4665 if (! lvalue_p (arg) && (pedantic || complain == tf_none))
4667 if (complain & tf_error)
4668 permerror ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4670 return error_mark_node;
4675 arg = BASELINK_FUNCTIONS (arg);
4679 arg = OVL_CURRENT (arg);
4683 /* Turn a reference to a non-static data member into a
4684 pointer-to-member. */
4689 if (!PTRMEM_OK_P (arg))
4690 return cp_build_unary_op (code, arg, 0, complain);
4692 t = TREE_OPERAND (arg, 1);
4693 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4695 if (complain & tf_error)
4696 error ("cannot create pointer to reference member %qD", t);
4697 return error_mark_node;
4700 type = build_ptrmem_type (context_for_name_lookup (t),
4702 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4710 /* Anything not already handled and not a true memory reference
4712 if (TREE_CODE (argtype) != FUNCTION_TYPE
4713 && TREE_CODE (argtype) != METHOD_TYPE
4714 && TREE_CODE (arg) != OFFSET_REF
4715 && !lvalue_or_else (arg, lv_addressof, complain))
4716 return error_mark_node;
4718 if (argtype != error_mark_node)
4719 argtype = build_pointer_type (argtype);
4721 /* In a template, we are processing a non-dependent expression
4722 so we can just form an ADDR_EXPR with the correct type. */
4723 if (processing_template_decl)
4725 val = build_address (arg);
4726 if (TREE_CODE (arg) == OFFSET_REF)
4727 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4731 if (TREE_CODE (arg) != COMPONENT_REF)
4733 val = build_address (arg);
4734 if (TREE_CODE (arg) == OFFSET_REF)
4735 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4737 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4739 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4741 /* We can only get here with a single static member
4743 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4744 && DECL_STATIC_FUNCTION_P (fn));
4746 val = build_address (fn);
4747 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4748 /* Do not lose object's side effects. */
4749 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4750 TREE_OPERAND (arg, 0), val);
4752 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4754 if (complain & tf_error)
4755 error ("attempt to take address of bit-field structure member %qD",
4756 TREE_OPERAND (arg, 1));
4757 return error_mark_node;
4761 tree object = TREE_OPERAND (arg, 0);
4762 tree field = TREE_OPERAND (arg, 1);
4763 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4764 (TREE_TYPE (object), decl_type_context (field)));
4765 val = build_address (arg);
4768 if (TREE_CODE (argtype) == POINTER_TYPE
4769 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4771 build_ptrmemfunc_type (argtype);
4772 val = build_ptrmemfunc (argtype, val, 0,
4773 /*c_cast_p=*/false);
4785 argtype = TREE_TYPE (arg);
4786 return fold_if_not_in_template (build1 (code, argtype, arg));
4789 if (complain & tf_error)
4790 error ("%s", errstring);
4791 return error_mark_node;
4794 /* Hook for the c-common bits that build a unary op. */
4796 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4798 return cp_build_unary_op (code, xarg, noconvert, tf_warning_or_error);
4801 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4802 for certain kinds of expressions which are not really lvalues
4803 but which we can accept as lvalues.
4805 If ARG is not a kind of expression we can handle, return
4809 unary_complex_lvalue (enum tree_code code, tree arg)
4811 /* Inside a template, making these kinds of adjustments is
4812 pointless; we are only concerned with the type of the
4814 if (processing_template_decl)
4817 /* Handle (a, b) used as an "lvalue". */
4818 if (TREE_CODE (arg) == COMPOUND_EXPR)
4820 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 1), 0,
4821 tf_warning_or_error);
4822 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4823 TREE_OPERAND (arg, 0), real_result);
4826 /* Handle (a ? b : c) used as an "lvalue". */
4827 if (TREE_CODE (arg) == COND_EXPR
4828 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4829 return rationalize_conditional_expr (code, arg, tf_warning_or_error);
4831 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4832 if (TREE_CODE (arg) == MODIFY_EXPR
4833 || TREE_CODE (arg) == PREINCREMENT_EXPR
4834 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4836 tree lvalue = TREE_OPERAND (arg, 0);
4837 if (TREE_SIDE_EFFECTS (lvalue))
4839 lvalue = stabilize_reference (lvalue);
4840 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4841 lvalue, TREE_OPERAND (arg, 1));
4843 return unary_complex_lvalue
4844 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4847 if (code != ADDR_EXPR)
4850 /* Handle (a = b) used as an "lvalue" for `&'. */
4851 if (TREE_CODE (arg) == MODIFY_EXPR
4852 || TREE_CODE (arg) == INIT_EXPR)
4854 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 0), 0,
4855 tf_warning_or_error);
4856 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4858 TREE_NO_WARNING (arg) = 1;
4862 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4863 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4864 || TREE_CODE (arg) == OFFSET_REF)
4867 /* We permit compiler to make function calls returning
4868 objects of aggregate type look like lvalues. */
4872 if (TREE_CODE (targ) == SAVE_EXPR)
4873 targ = TREE_OPERAND (targ, 0);
4875 if (TREE_CODE (targ) == CALL_EXPR && MAYBE_CLASS_TYPE_P (TREE_TYPE (targ)))
4877 if (TREE_CODE (arg) == SAVE_EXPR)
4880 targ = build_cplus_new (TREE_TYPE (arg), arg);
4881 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4884 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4885 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4886 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4889 /* Don't let anything else be handled specially. */
4893 /* Mark EXP saying that we need to be able to take the
4894 address of it; it should not be allocated in a register.
4895 Value is true if successful.
4897 C++: we do not allow `current_class_ptr' to be addressable. */
4900 cxx_mark_addressable (tree exp)
4905 switch (TREE_CODE (x))
4912 x = TREE_OPERAND (x, 0);
4916 if (x == current_class_ptr)
4918 error ("cannot take the address of %<this%>, which is an rvalue expression");
4919 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4925 /* Caller should not be trying to mark initialized
4926 constant fields addressable. */
4927 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4928 || DECL_IN_AGGR_P (x) == 0
4930 || DECL_EXTERNAL (x));
4935 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4936 && !DECL_ARTIFICIAL (x))
4938 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4941 ("address of explicit register variable %qD requested", x);
4944 else if (extra_warnings)
4946 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4948 TREE_ADDRESSABLE (x) = 1;
4952 TREE_ADDRESSABLE (x) = 1;
4956 TREE_ADDRESSABLE (x) = 1;
4960 TREE_ADDRESSABLE (x) = 1;
4961 cxx_mark_addressable (TREE_OPERAND (x, 0));
4969 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4972 build_x_conditional_expr (tree ifexp, tree op1, tree op2,
4973 tsubst_flags_t complain)
4975 tree orig_ifexp = ifexp;
4976 tree orig_op1 = op1;
4977 tree orig_op2 = op2;
4980 if (processing_template_decl)
4982 /* The standard says that the expression is type-dependent if
4983 IFEXP is type-dependent, even though the eventual type of the
4984 expression doesn't dependent on IFEXP. */
4985 if (type_dependent_expression_p (ifexp)
4986 /* As a GNU extension, the middle operand may be omitted. */
4987 || (op1 && type_dependent_expression_p (op1))
4988 || type_dependent_expression_p (op2))
4989 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4990 ifexp = build_non_dependent_expr (ifexp);
4992 op1 = build_non_dependent_expr (op1);
4993 op2 = build_non_dependent_expr (op2);
4996 expr = build_conditional_expr (ifexp, op1, op2, complain);
4997 if (processing_template_decl && expr != error_mark_node)
4998 return build_min_non_dep (COND_EXPR, expr,
4999 orig_ifexp, orig_op1, orig_op2);
5003 /* Given a list of expressions, return a compound expression
5004 that performs them all and returns the value of the last of them. */
5006 tree build_x_compound_expr_from_list (tree list, const char *msg)
5008 tree expr = TREE_VALUE (list);
5010 if (TREE_CHAIN (list))
5013 permerror ("%s expression list treated as compound expression", msg);
5015 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
5016 expr = build_x_compound_expr (expr, TREE_VALUE (list),
5017 tf_warning_or_error);
5023 /* Handle overloading of the ',' operator when needed. */
5026 build_x_compound_expr (tree op1, tree op2, tsubst_flags_t complain)
5029 tree orig_op1 = op1;
5030 tree orig_op2 = op2;
5032 if (processing_template_decl)
5034 if (type_dependent_expression_p (op1)
5035 || type_dependent_expression_p (op2))
5036 return build_min_nt (COMPOUND_EXPR, op1, op2);
5037 op1 = build_non_dependent_expr (op1);
5038 op2 = build_non_dependent_expr (op2);
5041 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
5042 /*overloaded_p=*/NULL, complain);
5044 result = cp_build_compound_expr (op1, op2, complain);
5046 if (processing_template_decl && result != error_mark_node)
5047 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
5052 /* Like cp_build_compound_expr, but for the c-common bits. */
5055 build_compound_expr (tree lhs, tree rhs)
5057 return cp_build_compound_expr (lhs, rhs, tf_warning_or_error);
5060 /* Build a compound expression. */
5063 cp_build_compound_expr (tree lhs, tree rhs, tsubst_flags_t complain)
5065 lhs = convert_to_void (lhs, "left-hand operand of comma", complain);
5067 if (lhs == error_mark_node || rhs == error_mark_node)
5068 return error_mark_node;
5070 if (TREE_CODE (rhs) == TARGET_EXPR)
5072 /* If the rhs is a TARGET_EXPR, then build the compound
5073 expression inside the target_expr's initializer. This
5074 helps the compiler to eliminate unnecessary temporaries. */
5075 tree init = TREE_OPERAND (rhs, 1);
5077 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
5078 TREE_OPERAND (rhs, 1) = init;
5083 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
5086 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
5087 casts away constness. CAST gives the type of cast. */
5090 check_for_casting_away_constness (tree src_type, tree dest_type,
5091 enum tree_code cast)
5093 /* C-style casts are allowed to cast away constness. With
5094 WARN_CAST_QUAL, we still want to issue a warning. */
5095 if (cast == CAST_EXPR && !warn_cast_qual)
5098 if (casts_away_constness (src_type, dest_type))
5102 warning (OPT_Wcast_qual,
5103 "cast from type %qT to type %qT casts away constness",
5104 src_type, dest_type);
5107 case STATIC_CAST_EXPR:
5108 error ("static_cast from type %qT to type %qT casts away constness",
5109 src_type, dest_type);
5112 case REINTERPRET_CAST_EXPR:
5113 error ("reinterpret_cast from type %qT to type %qT casts away constness",
5114 src_type, dest_type);
5121 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
5122 (another pointer-to-member type in the same hierarchy) and return
5123 the converted expression. If ALLOW_INVERSE_P is permitted, a
5124 pointer-to-derived may be converted to pointer-to-base; otherwise,
5125 only the other direction is permitted. If C_CAST_P is true, this
5126 conversion is taking place as part of a C-style cast. */
5129 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
5132 if (TYPE_PTRMEM_P (type))
5136 if (TREE_CODE (expr) == PTRMEM_CST)
5137 expr = cplus_expand_constant (expr);
5138 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
5139 TYPE_PTRMEM_CLASS_TYPE (type),
5142 if (!integer_zerop (delta))
5144 tree cond, op1, op2;
5146 cond = cp_build_binary_op (EQ_EXPR,
5148 build_int_cst (TREE_TYPE (expr), -1),
5149 tf_warning_or_error);
5150 op1 = build_nop (ptrdiff_type_node, expr);
5151 op2 = cp_build_binary_op (PLUS_EXPR, op1, delta,
5152 tf_warning_or_error);
5154 expr = fold_build3 (COND_EXPR, ptrdiff_type_node, cond, op1, op2);
5158 return build_nop (type, expr);
5161 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
5162 allow_inverse_p, c_cast_p);
5165 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
5166 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
5167 Otherwise, return EXPR unchanged. */
5170 ignore_overflows (tree expr, tree orig)
5172 if (TREE_CODE (expr) == INTEGER_CST
5173 && CONSTANT_CLASS_P (orig)
5174 && TREE_CODE (orig) != STRING_CST
5175 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
5177 if (!TREE_OVERFLOW (orig))
5178 /* Ensure constant sharing. */
5179 expr = build_int_cst_wide (TREE_TYPE (expr),
5180 TREE_INT_CST_LOW (expr),
5181 TREE_INT_CST_HIGH (expr));
5184 /* Avoid clobbering a shared constant. */
5185 expr = copy_node (expr);
5186 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
5192 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
5193 this static_cast is being attempted as one of the possible casts
5194 allowed by a C-style cast. (In that case, accessibility of base
5195 classes is not considered, and it is OK to cast away
5196 constness.) Return the result of the cast. *VALID_P is set to
5197 indicate whether or not the cast was valid. */
5200 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
5201 bool *valid_p, tsubst_flags_t complain)
5207 /* Assume the cast is valid. */
5210 intype = TREE_TYPE (expr);
5212 /* Save casted types in the function's used types hash table. */
5213 used_types_insert (type);
5215 /* [expr.static.cast]
5217 An lvalue of type "cv1 B", where B is a class type, can be cast
5218 to type "reference to cv2 D", where D is a class derived (clause
5219 _class.derived_) from B, if a valid standard conversion from
5220 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
5221 same cv-qualification as, or greater cv-qualification than, cv1,
5222 and B is not a virtual base class of D. */
5223 /* We check this case before checking the validity of "TYPE t =
5224 EXPR;" below because for this case:
5227 struct D : public B { D(const B&); };
5229 void f() { static_cast<const D&>(b); }
5231 we want to avoid constructing a new D. The standard is not
5232 completely clear about this issue, but our interpretation is
5233 consistent with other compilers. */
5234 if (TREE_CODE (type) == REFERENCE_TYPE
5235 && CLASS_TYPE_P (TREE_TYPE (type))
5236 && CLASS_TYPE_P (intype)
5237 && real_lvalue_p (expr)
5238 && DERIVED_FROM_P (intype, TREE_TYPE (type))
5239 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
5240 build_pointer_type (TYPE_MAIN_VARIANT
5241 (TREE_TYPE (type))))
5243 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5247 /* There is a standard conversion from "D*" to "B*" even if "B"
5248 is ambiguous or inaccessible. If this is really a
5249 static_cast, then we check both for inaccessibility and
5250 ambiguity. However, if this is a static_cast being performed
5251 because the user wrote a C-style cast, then accessibility is
5253 base = lookup_base (TREE_TYPE (type), intype,
5254 c_cast_p ? ba_unique : ba_check,
5257 /* Convert from "B*" to "D*". This function will check that "B"
5258 is not a virtual base of "D". */
5259 expr = build_base_path (MINUS_EXPR, build_address (expr),
5260 base, /*nonnull=*/false);
5261 /* Convert the pointer to a reference -- but then remember that
5262 there are no expressions with reference type in C++. */
5263 return convert_from_reference (build_nop (type, expr));
5268 /* [expr.static.cast]
5270 An expression e can be explicitly converted to a type T using a
5271 static_cast of the form static_cast<T>(e) if the declaration T
5272 t(e);" is well-formed, for some invented temporary variable
5274 result = perform_direct_initialization_if_possible (type, expr,
5275 c_cast_p, complain);
5278 result = convert_from_reference (result);
5280 /* Ignore any integer overflow caused by the cast. */
5281 result = ignore_overflows (result, orig);
5283 /* [expr.static.cast]
5285 If T is a reference type, the result is an lvalue; otherwise,
5286 the result is an rvalue. */
5287 if (TREE_CODE (type) != REFERENCE_TYPE)
5288 result = rvalue (result);
5292 /* [expr.static.cast]
5294 Any expression can be explicitly converted to type cv void. */
5295 if (TREE_CODE (type) == VOID_TYPE)
5296 return convert_to_void (expr, /*implicit=*/NULL, complain);
5298 /* [expr.static.cast]
5300 The inverse of any standard conversion sequence (clause _conv_),
5301 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5302 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5303 (_conv.bool_) conversions, can be performed explicitly using
5304 static_cast subject to the restriction that the explicit
5305 conversion does not cast away constness (_expr.const.cast_), and
5306 the following additional rules for specific cases: */
5307 /* For reference, the conversions not excluded are: integral
5308 promotions, floating point promotion, integral conversions,
5309 floating point conversions, floating-integral conversions,
5310 pointer conversions, and pointer to member conversions. */
5313 A value of integral _or enumeration_ type can be explicitly
5314 converted to an enumeration type. */
5315 /* The effect of all that is that any conversion between any two
5316 types which are integral, floating, or enumeration types can be
5318 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5319 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5321 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5323 /* Ignore any integer overflow caused by the cast. */
5324 expr = ignore_overflows (expr, orig);
5328 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5329 && CLASS_TYPE_P (TREE_TYPE (type))
5330 && CLASS_TYPE_P (TREE_TYPE (intype))
5331 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5332 (TREE_TYPE (intype))),
5333 build_pointer_type (TYPE_MAIN_VARIANT
5334 (TREE_TYPE (type)))))
5339 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5340 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5341 c_cast_p ? ba_unique : ba_check,
5343 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5346 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5347 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5354 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5355 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5357 if (TYPE_PTRMEM_P (type))
5359 t1 = (build_ptrmem_type
5361 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5362 t2 = (build_ptrmem_type
5364 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5371 if (can_convert (t1, t2) || can_convert (t2, t1))
5374 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5375 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5380 /* [expr.static.cast]
5382 An rvalue of type "pointer to cv void" can be explicitly
5383 converted to a pointer to object type. A value of type pointer
5384 to object converted to "pointer to cv void" and back to the
5385 original pointer type will have its original value. */
5386 if (TREE_CODE (intype) == POINTER_TYPE
5387 && VOID_TYPE_P (TREE_TYPE (intype))
5388 && TYPE_PTROB_P (type))
5391 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5392 return build_nop (type, expr);
5396 return error_mark_node;
5399 /* Return an expression representing static_cast<TYPE>(EXPR). */
5402 build_static_cast (tree type, tree expr, tsubst_flags_t complain)
5407 if (type == error_mark_node || expr == error_mark_node)
5408 return error_mark_node;
5410 if (processing_template_decl)
5412 expr = build_min (STATIC_CAST_EXPR, type, expr);
5413 /* We don't know if it will or will not have side effects. */
5414 TREE_SIDE_EFFECTS (expr) = 1;
5415 return convert_from_reference (expr);
5418 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5419 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5420 if (TREE_CODE (type) != REFERENCE_TYPE
5421 && TREE_CODE (expr) == NOP_EXPR
5422 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5423 expr = TREE_OPERAND (expr, 0);
5425 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p,
5430 if (complain & tf_error)
5431 error ("invalid static_cast from type %qT to type %qT",
5432 TREE_TYPE (expr), type);
5433 return error_mark_node;
5436 /* EXPR is an expression with member function or pointer-to-member
5437 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5438 not permitted by ISO C++, but we accept it in some modes. If we
5439 are not in one of those modes, issue a diagnostic. Return the
5440 converted expression. */
5443 convert_member_func_to_ptr (tree type, tree expr)
5448 intype = TREE_TYPE (expr);
5449 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5450 || TREE_CODE (intype) == METHOD_TYPE);
5452 if (pedantic || warn_pmf2ptr)
5453 pedwarn ("converting from %qT to %qT", intype, type);
5455 if (TREE_CODE (intype) == METHOD_TYPE)
5456 expr = build_addr_func (expr);
5457 else if (TREE_CODE (expr) == PTRMEM_CST)
5458 expr = build_address (PTRMEM_CST_MEMBER (expr));
5461 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5462 decl = build_address (decl);
5463 expr = get_member_function_from_ptrfunc (&decl, expr);
5466 return build_nop (type, expr);
5469 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5470 If C_CAST_P is true, this reinterpret cast is being done as part of
5471 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5472 indicate whether or not reinterpret_cast was valid. */
5475 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5476 bool *valid_p, tsubst_flags_t complain)
5480 /* Assume the cast is invalid. */
5484 if (type == error_mark_node || error_operand_p (expr))
5485 return error_mark_node;
5487 intype = TREE_TYPE (expr);
5489 /* Save casted types in the function's used types hash table. */
5490 used_types_insert (type);
5492 /* [expr.reinterpret.cast]
5493 An lvalue expression of type T1 can be cast to the type
5494 "reference to T2" if an expression of type "pointer to T1" can be
5495 explicitly converted to the type "pointer to T2" using a
5496 reinterpret_cast. */
5497 if (TREE_CODE (type) == REFERENCE_TYPE)
5499 if (! real_lvalue_p (expr))
5501 if (complain & tf_error)
5502 error ("invalid cast of an rvalue expression of type "
5505 return error_mark_node;
5508 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5509 "B" are related class types; the reinterpret_cast does not
5510 adjust the pointer. */
5511 if (TYPE_PTR_P (intype)
5512 && (complain & tf_warning)
5513 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5514 COMPARE_BASE | COMPARE_DERIVED)))
5515 warning (0, "casting %qT to %qT does not dereference pointer",
5518 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, complain);
5519 if (expr != error_mark_node)
5520 expr = build_reinterpret_cast_1
5521 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5523 if (expr != error_mark_node)
5524 expr = cp_build_indirect_ref (expr, 0, complain);
5528 /* As a G++ extension, we consider conversions from member
5529 functions, and pointers to member functions to
5530 pointer-to-function and pointer-to-void types. If
5531 -Wno-pmf-conversions has not been specified,
5532 convert_member_func_to_ptr will issue an error message. */
5533 if ((TYPE_PTRMEMFUNC_P (intype)
5534 || TREE_CODE (intype) == METHOD_TYPE)
5535 && TYPE_PTR_P (type)
5536 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5537 || VOID_TYPE_P (TREE_TYPE (type))))
5538 return convert_member_func_to_ptr (type, expr);
5540 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5541 array-to-pointer, and function-to-pointer conversions are
5543 expr = decay_conversion (expr);
5545 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5546 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5547 if (TREE_CODE (expr) == NOP_EXPR
5548 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5549 expr = TREE_OPERAND (expr, 0);
5551 if (error_operand_p (expr))
5552 return error_mark_node;
5554 intype = TREE_TYPE (expr);
5556 /* [expr.reinterpret.cast]
5557 A pointer can be converted to any integral type large enough to
5559 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5561 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5563 if (complain & tf_error)
5564 permerror ("cast from %qT to %qT loses precision",
5567 return error_mark_node;
5570 /* [expr.reinterpret.cast]
5571 A value of integral or enumeration type can be explicitly
5572 converted to a pointer. */
5573 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5576 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5577 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5578 return fold_if_not_in_template (build_nop (type, expr));
5579 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5580 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5585 check_for_casting_away_constness (intype, type, REINTERPRET_CAST_EXPR);
5586 /* Warn about possible alignment problems. */
5587 if (STRICT_ALIGNMENT && warn_cast_align
5588 && (complain & tf_warning)
5589 && !VOID_TYPE_P (type)
5590 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5591 && COMPLETE_TYPE_P (TREE_TYPE (type))
5592 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5593 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5594 warning (OPT_Wcast_align, "cast from %qT to %qT "
5595 "increases required alignment of target type", intype, type);
5597 /* We need to strip nops here, because the front end likes to
5598 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5600 if (warn_strict_aliasing <= 2)
5601 strict_aliasing_warning (intype, type, sexpr);
5603 return fold_if_not_in_template (build_nop (type, expr));
5605 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5606 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5608 if (pedantic && (complain & tf_warning))
5609 /* Only issue a warning, as we have always supported this
5610 where possible, and it is necessary in some cases. DR 195
5611 addresses this issue, but as of 2004/10/26 is still in
5613 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5614 return fold_if_not_in_template (build_nop (type, expr));
5616 else if (TREE_CODE (type) == VECTOR_TYPE)
5617 return fold_if_not_in_template (convert_to_vector (type, expr));
5618 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5619 return fold_if_not_in_template (convert_to_integer (type, expr));
5624 if (complain & tf_error)
5625 error ("invalid cast from type %qT to type %qT", intype, type);
5626 return error_mark_node;
5629 return cp_convert (type, expr);
5633 build_reinterpret_cast (tree type, tree expr, tsubst_flags_t complain)
5635 if (type == error_mark_node || expr == error_mark_node)
5636 return error_mark_node;
5638 if (processing_template_decl)
5640 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5642 if (!TREE_SIDE_EFFECTS (t)
5643 && type_dependent_expression_p (expr))
5644 /* There might turn out to be side effects inside expr. */
5645 TREE_SIDE_EFFECTS (t) = 1;
5646 return convert_from_reference (t);
5649 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5650 /*valid_p=*/NULL, complain);
5653 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5654 return an appropriate expression. Otherwise, return
5655 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5656 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5657 performing a C-style cast, its value upon return will indicate
5658 whether or not the conversion succeeded. */
5661 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5665 tree reference_type;
5667 /* Callers are responsible for handling error_mark_node as a
5668 destination type. */
5669 gcc_assert (dst_type != error_mark_node);
5670 /* In a template, callers should be building syntactic
5671 representations of casts, not using this machinery. */
5672 gcc_assert (!processing_template_decl);
5674 /* Assume the conversion is invalid. */
5678 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5681 error ("invalid use of const_cast with type %qT, "
5682 "which is not a pointer, "
5683 "reference, nor a pointer-to-data-member type", dst_type);
5684 return error_mark_node;
5687 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5690 error ("invalid use of const_cast with type %qT, which is a pointer "
5691 "or reference to a function type", dst_type);
5692 return error_mark_node;
5695 /* Save casted types in the function's used types hash table. */
5696 used_types_insert (dst_type);
5698 src_type = TREE_TYPE (expr);
5699 /* Expressions do not really have reference types. */
5700 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5701 src_type = TREE_TYPE (src_type);
5703 /* [expr.const.cast]
5705 An lvalue of type T1 can be explicitly converted to an lvalue of
5706 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5707 types) if a pointer to T1 can be explicitly converted to the type
5708 pointer to T2 using a const_cast. */
5709 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5711 reference_type = dst_type;
5712 if (! real_lvalue_p (expr))
5715 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5716 src_type, dst_type);
5717 return error_mark_node;
5719 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5720 src_type = build_pointer_type (src_type);
5724 reference_type = NULL_TREE;
5725 /* If the destination type is not a reference type, the
5726 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5727 conversions are performed. */
5728 src_type = type_decays_to (src_type);
5729 if (src_type == error_mark_node)
5730 return error_mark_node;
5733 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5734 && comp_ptr_ttypes_const (dst_type, src_type))
5739 /* This cast is actually a C-style cast. Issue a warning if
5740 the user is making a potentially unsafe cast. */
5741 check_for_casting_away_constness (src_type, dst_type, CAST_EXPR);
5745 expr = cp_build_unary_op (ADDR_EXPR, expr, 0,
5746 complain? tf_warning_or_error : tf_none);
5747 expr = build_nop (reference_type, expr);
5748 return convert_from_reference (expr);
5752 expr = decay_conversion (expr);
5753 /* build_c_cast puts on a NOP_EXPR to make the result not an
5754 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5755 non-lvalue context. */
5756 if (TREE_CODE (expr) == NOP_EXPR
5757 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5758 expr = TREE_OPERAND (expr, 0);
5759 return build_nop (dst_type, expr);
5764 error ("invalid const_cast from type %qT to type %qT",
5765 src_type, dst_type);
5766 return error_mark_node;
5770 build_const_cast (tree type, tree expr, tsubst_flags_t complain)
5772 if (type == error_mark_node || error_operand_p (expr))
5773 return error_mark_node;
5775 if (processing_template_decl)
5777 tree t = build_min (CONST_CAST_EXPR, type, expr);
5779 if (!TREE_SIDE_EFFECTS (t)
5780 && type_dependent_expression_p (expr))
5781 /* There might turn out to be side effects inside expr. */
5782 TREE_SIDE_EFFECTS (t) = 1;
5783 return convert_from_reference (t);
5786 return build_const_cast_1 (type, expr, complain & tf_error,
5790 /* Like cp_build_c_cast, but for the c-common bits. */
5793 build_c_cast (tree type, tree expr)
5795 return cp_build_c_cast (type, expr, tf_warning_or_error);
5798 /* Build an expression representing an explicit C-style cast to type
5799 TYPE of expression EXPR. */
5802 cp_build_c_cast (tree type, tree expr, tsubst_flags_t complain)
5808 if (type == error_mark_node || error_operand_p (expr))
5809 return error_mark_node;
5811 if (processing_template_decl)
5813 tree t = build_min (CAST_EXPR, type,
5814 tree_cons (NULL_TREE, value, NULL_TREE));
5815 /* We don't know if it will or will not have side effects. */
5816 TREE_SIDE_EFFECTS (t) = 1;
5817 return convert_from_reference (t);
5820 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5821 'Class') should always be retained, because this information aids
5822 in method lookup. */
5823 if (objc_is_object_ptr (type)
5824 && objc_is_object_ptr (TREE_TYPE (expr)))
5825 return build_nop (type, expr);
5827 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5828 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5829 if (TREE_CODE (type) != REFERENCE_TYPE
5830 && TREE_CODE (value) == NOP_EXPR
5831 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5832 value = TREE_OPERAND (value, 0);
5834 if (TREE_CODE (type) == ARRAY_TYPE)
5836 /* Allow casting from T1* to T2[] because Cfront allows it.
5837 NIHCL uses it. It is not valid ISO C++ however. */
5838 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5840 if (complain & tf_error)
5841 permerror ("ISO C++ forbids casting to an array type %qT", type);
5843 return error_mark_node;
5844 type = build_pointer_type (TREE_TYPE (type));
5848 if (complain & tf_error)
5849 error ("ISO C++ forbids casting to an array type %qT", type);
5850 return error_mark_node;
5854 if (TREE_CODE (type) == FUNCTION_TYPE
5855 || TREE_CODE (type) == METHOD_TYPE)
5857 if (complain & tf_error)
5858 error ("invalid cast to function type %qT", type);
5859 return error_mark_node;
5862 /* A C-style cast can be a const_cast. */
5863 result = build_const_cast_1 (type, value, /*complain=*/false,
5868 /* Or a static cast. */
5869 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5870 &valid_p, complain);
5871 /* Or a reinterpret_cast. */
5873 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5874 &valid_p, complain);
5875 /* The static_cast or reinterpret_cast may be followed by a
5878 /* A valid cast may result in errors if, for example, a
5879 conversion to am ambiguous base class is required. */
5880 && !error_operand_p (result))
5884 /* Non-class rvalues always have cv-unqualified type. */
5885 if (!CLASS_TYPE_P (type))
5886 type = TYPE_MAIN_VARIANT (type);
5887 result_type = TREE_TYPE (result);
5888 if (!CLASS_TYPE_P (result_type))
5889 result_type = TYPE_MAIN_VARIANT (result_type);
5890 /* If the type of RESULT does not match TYPE, perform a
5891 const_cast to make it match. If the static_cast or
5892 reinterpret_cast succeeded, we will differ by at most
5893 cv-qualification, so the follow-on const_cast is guaranteed
5895 if (!same_type_p (non_reference (type), non_reference (result_type)))
5897 result = build_const_cast_1 (type, result, false, &valid_p);
5898 gcc_assert (valid_p);
5903 return error_mark_node;
5906 /* For use from the C common bits. */
5908 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5910 return cp_build_modify_expr (lhs, modifycode, rhs, tf_warning_or_error);
5913 /* Build an assignment expression of lvalue LHS from value RHS.
5914 MODIFYCODE is the code for a binary operator that we use
5915 to combine the old value of LHS with RHS to get the new value.
5916 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5918 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5921 cp_build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
5922 tsubst_flags_t complain)
5926 tree lhstype = TREE_TYPE (lhs);
5927 tree olhstype = lhstype;
5928 tree olhs = NULL_TREE;
5929 bool plain_assign = (modifycode == NOP_EXPR);
5931 /* Avoid duplicate error messages from operands that had errors. */
5932 if (error_operand_p (lhs) || error_operand_p (rhs))
5933 return error_mark_node;
5935 /* Handle control structure constructs used as "lvalues". */
5936 switch (TREE_CODE (lhs))
5938 /* Handle --foo = 5; as these are valid constructs in C++. */
5939 case PREDECREMENT_EXPR:
5940 case PREINCREMENT_EXPR:
5941 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5942 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5943 stabilize_reference (TREE_OPERAND (lhs, 0)),
5944 TREE_OPERAND (lhs, 1));
5945 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0),
5946 modifycode, rhs, complain);
5947 if (newrhs == error_mark_node)
5948 return error_mark_node;
5949 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5951 /* Handle (a, b) used as an "lvalue". */
5953 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 1),
5954 modifycode, rhs, complain);
5955 if (newrhs == error_mark_node)
5956 return error_mark_node;
5957 return build2 (COMPOUND_EXPR, lhstype,
5958 TREE_OPERAND (lhs, 0), newrhs);
5961 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5962 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5963 stabilize_reference (TREE_OPERAND (lhs, 0)),
5964 TREE_OPERAND (lhs, 1));
5965 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs,
5967 if (newrhs == error_mark_node)
5968 return error_mark_node;
5969 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5973 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5974 when neither operand has side-effects. */
5975 if (!lvalue_or_else (lhs, lv_assign, complain))
5976 return error_mark_node;
5978 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5979 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5981 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5982 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5984 TREE_OPERAND (lhs, 0),
5985 TREE_OPERAND (lhs, 1)),
5986 TREE_OPERAND (lhs, 0),
5987 TREE_OPERAND (lhs, 1));
5990 /* Handle (a ? b : c) used as an "lvalue". */
5993 /* Produce (a ? (b = rhs) : (c = rhs))
5994 except that the RHS goes through a save-expr
5995 so the code to compute it is only emitted once. */
5997 tree preeval = NULL_TREE;
5999 if (VOID_TYPE_P (TREE_TYPE (rhs)))
6001 if (complain & tf_error)
6002 error ("void value not ignored as it ought to be");
6003 return error_mark_node;
6006 rhs = stabilize_expr (rhs, &preeval);
6008 /* Check this here to avoid odd errors when trying to convert
6009 a throw to the type of the COND_EXPR. */
6010 if (!lvalue_or_else (lhs, lv_assign, complain))
6011 return error_mark_node;
6013 cond = build_conditional_expr
6014 (TREE_OPERAND (lhs, 0),
6015 cp_build_modify_expr (TREE_OPERAND (lhs, 1),
6016 modifycode, rhs, complain),
6017 cp_build_modify_expr (TREE_OPERAND (lhs, 2),
6018 modifycode, rhs, complain),
6021 if (cond == error_mark_node)
6023 /* Make sure the code to compute the rhs comes out
6024 before the split. */
6026 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
6034 if (modifycode == INIT_EXPR)
6036 if (TREE_CODE (rhs) == CONSTRUCTOR)
6038 if (! same_type_p (TREE_TYPE (rhs), lhstype))
6039 /* Call convert to generate an error; see PR 11063. */
6040 rhs = convert (lhstype, rhs);
6041 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
6042 TREE_SIDE_EFFECTS (result) = 1;
6045 else if (! MAYBE_CLASS_TYPE_P (lhstype))
6046 /* Do the default thing. */;
6049 result = build_special_member_call (lhs, complete_ctor_identifier,
6050 build_tree_list (NULL_TREE, rhs),
6051 lhstype, LOOKUP_NORMAL,
6053 if (result == NULL_TREE)
6054 return error_mark_node;
6060 lhs = require_complete_type (lhs);
6061 if (lhs == error_mark_node)
6062 return error_mark_node;
6064 if (modifycode == NOP_EXPR)
6066 /* `operator=' is not an inheritable operator. */
6067 if (! MAYBE_CLASS_TYPE_P (lhstype))
6068 /* Do the default thing. */;
6071 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
6072 lhs, rhs, make_node (NOP_EXPR),
6073 /*overloaded_p=*/NULL,
6075 if (result == NULL_TREE)
6076 return error_mark_node;
6083 /* A binary op has been requested. Combine the old LHS
6084 value with the RHS producing the value we should actually
6085 store into the LHS. */
6086 gcc_assert (!((TREE_CODE (lhstype) == REFERENCE_TYPE
6087 && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype)))
6088 || MAYBE_CLASS_TYPE_P (lhstype)));
6090 lhs = stabilize_reference (lhs);
6091 newrhs = cp_build_binary_op (modifycode, lhs, rhs,
6093 if (newrhs == error_mark_node)
6095 if (complain & tf_error)
6096 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
6097 TREE_TYPE (lhs), TREE_TYPE (rhs));
6098 return error_mark_node;
6101 /* Now it looks like a plain assignment. */
6102 modifycode = NOP_EXPR;
6104 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
6105 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
6108 /* The left-hand side must be an lvalue. */
6109 if (!lvalue_or_else (lhs, lv_assign, complain))
6110 return error_mark_node;
6112 /* Warn about modifying something that is `const'. Don't warn if
6113 this is initialization. */
6114 if (modifycode != INIT_EXPR
6115 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
6116 /* Functions are not modifiable, even though they are
6118 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
6119 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
6120 /* If it's an aggregate and any field is const, then it is
6121 effectively const. */
6122 || (CLASS_TYPE_P (lhstype)
6123 && C_TYPE_FIELDS_READONLY (lhstype))))
6125 if (complain & tf_error)
6126 readonly_error (lhs, "assignment");
6128 return error_mark_node;
6131 /* If storing into a structure or union member, it has probably been
6132 given type `int'. Compute the type that would go with the actual
6133 amount of storage the member occupies. */
6135 if (TREE_CODE (lhs) == COMPONENT_REF
6136 && (TREE_CODE (lhstype) == INTEGER_TYPE
6137 || TREE_CODE (lhstype) == REAL_TYPE
6138 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
6140 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
6142 /* If storing in a field that is in actuality a short or narrower
6143 than one, we must store in the field in its actual type. */
6145 if (lhstype != TREE_TYPE (lhs))
6147 /* Avoid warnings converting integral types back into enums for
6149 if (TREE_CODE (lhstype) == INTEGER_TYPE
6150 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
6152 if (TREE_SIDE_EFFECTS (lhs))
6153 lhs = stabilize_reference (lhs);
6156 lhs = copy_node (lhs);
6157 TREE_TYPE (lhs) = lhstype;
6161 /* Convert new value to destination type. */
6163 if (TREE_CODE (lhstype) == ARRAY_TYPE)
6167 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
6168 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
6170 if (complain & tf_error)
6171 error ("incompatible types in assignment of %qT to %qT",
6172 TREE_TYPE (rhs), lhstype);
6173 return error_mark_node;
6176 /* Allow array assignment in compiler-generated code. */
6177 if (! DECL_ARTIFICIAL (current_function_decl))
6179 /* This routine is used for both initialization and assignment.
6180 Make sure the diagnostic message differentiates the context. */
6181 if (complain & tf_error)
6183 if (modifycode == INIT_EXPR)
6184 error ("array used as initializer");
6186 error ("invalid array assignment");
6188 return error_mark_node;
6191 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
6192 ? 1 + (modifycode != INIT_EXPR): 0;
6193 return build_vec_init (lhs, NULL_TREE, newrhs,
6194 /*explicit_default_init_p=*/false,
6195 from_array, complain);
6198 if (modifycode == INIT_EXPR)
6199 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
6200 "initialization", NULL_TREE, 0,
6204 /* Avoid warnings on enum bit fields. */
6205 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
6206 && TREE_CODE (lhstype) == INTEGER_TYPE)
6208 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
6209 NULL_TREE, 0, complain);
6210 newrhs = convert_force (lhstype, newrhs, 0);
6213 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
6214 NULL_TREE, 0, complain);
6215 if (TREE_CODE (newrhs) == CALL_EXPR
6216 && TYPE_NEEDS_CONSTRUCTING (lhstype))
6217 newrhs = build_cplus_new (lhstype, newrhs);
6219 /* Can't initialize directly from a TARGET_EXPR, since that would
6220 cause the lhs to be constructed twice, and possibly result in
6221 accidental self-initialization. So we force the TARGET_EXPR to be
6222 expanded without a target. */
6223 if (TREE_CODE (newrhs) == TARGET_EXPR)
6224 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
6225 TREE_OPERAND (newrhs, 0));
6228 if (newrhs == error_mark_node)
6229 return error_mark_node;
6231 if (c_dialect_objc () && flag_objc_gc)
6233 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
6239 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
6240 lhstype, lhs, newrhs);
6242 TREE_SIDE_EFFECTS (result) = 1;
6244 TREE_NO_WARNING (result) = 1;
6246 /* If we got the LHS in a different type for storing in,
6247 convert the result back to the nominal type of LHS
6248 so that the value we return always has the same type
6249 as the LHS argument. */
6251 if (olhstype == TREE_TYPE (result))
6255 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
6256 TREE_NO_WARNING (result) = 1;
6259 return convert_for_assignment (olhstype, result, "assignment",
6260 NULL_TREE, 0, complain);
6264 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
6265 tsubst_flags_t complain)
6267 if (processing_template_decl)
6268 return build_min_nt (MODOP_EXPR, lhs,
6269 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
6271 if (modifycode != NOP_EXPR)
6273 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
6274 make_node (modifycode),
6275 /*overloaded_p=*/NULL,
6279 TREE_NO_WARNING (rval) = 1;
6283 return cp_build_modify_expr (lhs, modifycode, rhs, complain);
6286 /* Helper function for get_delta_difference which assumes FROM is a base
6287 class of TO. Returns a delta for the conversion of pointer-to-member
6288 of FROM to pointer-to-member of TO. If the conversion is invalid,
6289 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
6290 If C_CAST_P is true, this conversion is taking place as part of a C-style
6294 get_delta_difference_1 (tree from, tree to, bool c_cast_p)
6299 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6300 if (kind == bk_inaccessible || kind == bk_ambig)
6302 error (" in pointer to member function conversion");
6303 return size_zero_node;
6307 if (kind != bk_via_virtual)
6308 return BINFO_OFFSET (binfo);
6310 /* FROM is a virtual base class of TO. Issue an error or warning
6311 depending on whether or not this is a reinterpret cast. */
6313 error ("pointer to member conversion via virtual base %qT",
6314 BINFO_TYPE (binfo_from_vbase (binfo)));
6316 return size_zero_node;
6323 /* Get difference in deltas for different pointer to member function
6324 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6325 the conversion is invalid, the constant is zero. If
6326 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6327 If C_CAST_P is true this conversion is taking place as part of a
6330 Note that the naming of FROM and TO is kind of backwards; the return
6331 value is what we add to a TO in order to get a FROM. They are named
6332 this way because we call this function to find out how to convert from
6333 a pointer to member of FROM to a pointer to member of TO. */
6336 get_delta_difference (tree from, tree to,
6337 bool allow_inverse_p,
6342 if (same_type_ignoring_top_level_qualifiers_p (from, to))
6343 /* Pointer to member of incomplete class is permitted*/
6344 result = size_zero_node;
6346 result = get_delta_difference_1 (from, to, c_cast_p);
6350 if (!allow_inverse_p)
6352 error_not_base_type (from, to);
6353 error (" in pointer to member conversion");
6354 result = size_zero_node;
6358 result = get_delta_difference_1 (to, from, c_cast_p);
6361 result = size_diffop (size_zero_node, result);
6364 error_not_base_type (from, to);
6365 error (" in pointer to member conversion");
6366 result = size_zero_node;
6371 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6375 /* Return a constructor for the pointer-to-member-function TYPE using
6376 the other components as specified. */
6379 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6384 VEC(constructor_elt, gc) *v;
6386 /* Pull the FIELD_DECLs out of the type. */
6387 pfn_field = TYPE_FIELDS (type);
6388 delta_field = TREE_CHAIN (pfn_field);
6390 /* Make sure DELTA has the type we want. */
6391 delta = convert_and_check (delta_type_node, delta);
6393 /* Convert to the correct target type if necessary. */
6394 pfn = fold_convert (TREE_TYPE (pfn_field), pfn);
6396 /* Finish creating the initializer. */
6397 v = VEC_alloc(constructor_elt, gc, 2);
6398 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6399 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6400 u = build_constructor (type, v);
6401 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6402 TREE_STATIC (u) = (TREE_CONSTANT (u)
6403 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6405 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6410 /* Build a constructor for a pointer to member function. It can be
6411 used to initialize global variables, local variable, or used
6412 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6415 If FORCE is nonzero, then force this conversion, even if
6416 we would rather not do it. Usually set when using an explicit
6417 cast. A C-style cast is being processed iff C_CAST_P is true.
6419 Return error_mark_node, if something goes wrong. */
6422 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6428 if (error_operand_p (pfn))
6429 return error_mark_node;
6431 pfn_type = TREE_TYPE (pfn);
6432 to_type = build_ptrmemfunc_type (type);
6434 /* Handle multiple conversions of pointer to member functions. */
6435 if (TYPE_PTRMEMFUNC_P (pfn_type))
6437 tree delta = NULL_TREE;
6438 tree npfn = NULL_TREE;
6442 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6443 error ("invalid conversion to type %qT from type %qT",
6446 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6447 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6451 /* We don't have to do any conversion to convert a
6452 pointer-to-member to its own type. But, we don't want to
6453 just return a PTRMEM_CST if there's an explicit cast; that
6454 cast should make the expression an invalid template argument. */
6455 if (TREE_CODE (pfn) != PTRMEM_CST)
6457 if (same_type_p (to_type, pfn_type))
6459 else if (integer_zerop (n))
6460 return build_reinterpret_cast (to_type, pfn,
6461 tf_warning_or_error);
6464 if (TREE_SIDE_EFFECTS (pfn))
6465 pfn = save_expr (pfn);
6467 /* Obtain the function pointer and the current DELTA. */
6468 if (TREE_CODE (pfn) == PTRMEM_CST)
6469 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6472 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6473 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6476 /* Just adjust the DELTA field. */
6477 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6478 (TREE_TYPE (delta), ptrdiff_type_node));
6479 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6480 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node,
6481 tf_warning_or_error);
6482 delta = cp_build_binary_op (PLUS_EXPR, delta, n, tf_warning_or_error);
6483 return build_ptrmemfunc1 (to_type, delta, npfn);
6486 /* Handle null pointer to member function conversions. */
6487 if (integer_zerop (pfn))
6489 pfn = build_c_cast (type, integer_zero_node);
6490 return build_ptrmemfunc1 (to_type,
6495 if (type_unknown_p (pfn))
6496 return instantiate_type (type, pfn, tf_warning_or_error);
6498 fn = TREE_OPERAND (pfn, 0);
6499 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6500 /* In a template, we will have preserved the
6502 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6503 return make_ptrmem_cst (to_type, fn);
6506 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6509 ??? There is no consistency as to the types returned for the above
6510 values. Some code acts as if it were a sizetype and some as if it were
6511 integer_type_node. */
6514 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6516 tree type = TREE_TYPE (cst);
6517 tree fn = PTRMEM_CST_MEMBER (cst);
6518 tree ptr_class, fn_class;
6520 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6522 /* The class that the function belongs to. */
6523 fn_class = DECL_CONTEXT (fn);
6525 /* The class that we're creating a pointer to member of. */
6526 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6528 /* First, calculate the adjustment to the function's class. */
6529 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6532 if (!DECL_VIRTUAL_P (fn))
6533 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6536 /* If we're dealing with a virtual function, we have to adjust 'this'
6537 again, to point to the base which provides the vtable entry for
6538 fn; the call will do the opposite adjustment. */
6539 tree orig_class = DECL_CONTEXT (fn);
6540 tree binfo = binfo_or_else (orig_class, fn_class);
6541 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6542 *delta, BINFO_OFFSET (binfo));
6543 *delta = fold_if_not_in_template (*delta);
6545 /* We set PFN to the vtable offset at which the function can be
6546 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6547 case delta is shifted left, and then incremented). */
6548 *pfn = DECL_VINDEX (fn);
6549 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6550 TYPE_SIZE_UNIT (vtable_entry_type));
6551 *pfn = fold_if_not_in_template (*pfn);
6553 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6555 case ptrmemfunc_vbit_in_pfn:
6556 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6558 *pfn = fold_if_not_in_template (*pfn);
6561 case ptrmemfunc_vbit_in_delta:
6562 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6563 *delta, integer_one_node);
6564 *delta = fold_if_not_in_template (*delta);
6565 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6566 *delta, integer_one_node);
6567 *delta = fold_if_not_in_template (*delta);
6574 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6575 *pfn = fold_if_not_in_template (*pfn);
6579 /* Return an expression for PFN from the pointer-to-member function
6583 pfn_from_ptrmemfunc (tree t)
6585 if (TREE_CODE (t) == PTRMEM_CST)
6590 expand_ptrmemfunc_cst (t, &delta, &pfn);
6595 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6598 /* Return an expression for DELTA from the pointer-to-member function
6602 delta_from_ptrmemfunc (tree t)
6604 if (TREE_CODE (t) == PTRMEM_CST)
6609 expand_ptrmemfunc_cst (t, &delta, &pfn);
6614 return build_ptrmemfunc_access_expr (t, delta_identifier);
6617 /* Convert value RHS to type TYPE as preparation for an assignment to
6618 an lvalue of type TYPE. ERRTYPE is a string to use in error
6619 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6620 are doing the conversion in order to pass the PARMNUMth argument of
6624 convert_for_assignment (tree type, tree rhs,
6625 const char *errtype, tree fndecl, int parmnum,
6626 tsubst_flags_t complain)
6629 enum tree_code coder;
6631 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6632 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6633 rhs = TREE_OPERAND (rhs, 0);
6635 rhstype = TREE_TYPE (rhs);
6636 coder = TREE_CODE (rhstype);
6638 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6639 && vector_types_convertible_p (type, rhstype, true))
6640 return convert (type, rhs);
6642 if (rhs == error_mark_node || rhstype == error_mark_node)
6643 return error_mark_node;
6644 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6645 return error_mark_node;
6647 /* The RHS of an assignment cannot have void type. */
6648 if (coder == VOID_TYPE)
6650 if (complain & tf_error)
6651 error ("void value not ignored as it ought to be");
6652 return error_mark_node;
6655 /* Simplify the RHS if possible. */
6656 if (TREE_CODE (rhs) == CONST_DECL)
6657 rhs = DECL_INITIAL (rhs);
6659 if (c_dialect_objc ())
6662 tree rname = fndecl;
6664 if (!strcmp (errtype, "assignment"))
6666 else if (!strcmp (errtype, "initialization"))
6670 tree selector = objc_message_selector ();
6674 if (selector && parmno > 1)
6681 if (objc_compare_types (type, rhstype, parmno, rname))
6682 return convert (type, rhs);
6687 The expression is implicitly converted (clause _conv_) to the
6688 cv-unqualified type of the left operand.
6690 We allow bad conversions here because by the time we get to this point
6691 we are committed to doing the conversion. If we end up doing a bad
6692 conversion, convert_like will complain. */
6693 if (!can_convert_arg_bad (type, rhstype, rhs))
6695 /* When -Wno-pmf-conversions is use, we just silently allow
6696 conversions from pointers-to-members to plain pointers. If
6697 the conversion doesn't work, cp_convert will complain. */
6699 && TYPE_PTR_P (type)
6700 && TYPE_PTRMEMFUNC_P (rhstype))
6701 rhs = cp_convert (strip_top_quals (type), rhs);
6704 if (complain & tf_error)
6706 /* If the right-hand side has unknown type, then it is an
6707 overloaded function. Call instantiate_type to get error
6709 if (rhstype == unknown_type_node)
6710 instantiate_type (type, rhs, tf_warning_or_error);
6712 error ("cannot convert %qT to %qT for argument %qP to %qD",
6713 rhstype, type, parmnum, fndecl);
6715 error ("cannot convert %qT to %qT in %s", rhstype, type,
6718 return error_mark_node;
6721 if (warn_missing_format_attribute)
6723 const enum tree_code codel = TREE_CODE (type);
6724 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6726 && check_missing_format_attribute (type, rhstype)
6727 && (complain & tf_warning))
6728 warning (OPT_Wmissing_format_attribute,
6729 "%s might be a candidate for a format attribute",
6733 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6735 if (warn_parentheses
6736 && type == boolean_type_node
6737 && TREE_CODE (rhs) == MODIFY_EXPR
6738 && !TREE_NO_WARNING (rhs)
6739 && TREE_TYPE (rhs) != boolean_type_node
6740 && (complain & tf_warning))
6742 warning (OPT_Wparentheses,
6743 "suggest parentheses around assignment used as truth value");
6744 TREE_NO_WARNING (rhs) = 1;
6747 return perform_implicit_conversion (strip_top_quals (type), rhs, complain);
6750 /* Convert RHS to be of type TYPE.
6751 If EXP is nonzero, it is the target of the initialization.
6752 ERRTYPE is a string to use in error messages.
6754 Two major differences between the behavior of
6755 `convert_for_assignment' and `convert_for_initialization'
6756 are that references are bashed in the former, while
6757 copied in the latter, and aggregates are assigned in
6758 the former (operator=) while initialized in the
6761 If using constructor make sure no conversion operator exists, if one does
6762 exist, an ambiguity exists.
6764 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6767 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6768 const char *errtype, tree fndecl, int parmnum,
6769 tsubst_flags_t complain)
6771 enum tree_code codel = TREE_CODE (type);
6773 enum tree_code coder;
6775 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6776 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6777 if (TREE_CODE (rhs) == NOP_EXPR
6778 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6779 && codel != REFERENCE_TYPE)
6780 rhs = TREE_OPERAND (rhs, 0);
6782 if (type == error_mark_node
6783 || rhs == error_mark_node
6784 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6785 return error_mark_node;
6787 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6788 && TREE_CODE (type) != ARRAY_TYPE
6789 && (TREE_CODE (type) != REFERENCE_TYPE
6790 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6791 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6792 && (TREE_CODE (type) != REFERENCE_TYPE
6793 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6794 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6795 rhs = decay_conversion (rhs);
6797 rhstype = TREE_TYPE (rhs);
6798 coder = TREE_CODE (rhstype);
6800 if (coder == ERROR_MARK)
6801 return error_mark_node;
6803 /* We accept references to incomplete types, so we can
6804 return here before checking if RHS is of complete type. */
6806 if (codel == REFERENCE_TYPE)
6808 /* This should eventually happen in convert_arguments. */
6809 int savew = 0, savee = 0;
6812 savew = warningcount, savee = errorcount;
6813 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6817 if (warningcount > savew)
6818 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6819 else if (errorcount > savee)
6820 error ("in passing argument %P of %q+D", parmnum, fndecl);
6826 exp = require_complete_type (exp);
6827 if (exp == error_mark_node)
6828 return error_mark_node;
6830 rhstype = non_reference (rhstype);
6832 type = complete_type (type);
6834 if (MAYBE_CLASS_TYPE_P (type))
6835 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6837 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum,
6841 /* If RETVAL is the address of, or a reference to, a local variable or
6842 temporary give an appropriate warning. */
6845 maybe_warn_about_returning_address_of_local (tree retval)
6847 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6848 tree whats_returned = retval;
6852 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6853 whats_returned = TREE_OPERAND (whats_returned, 1);
6854 else if (CONVERT_EXPR_P (whats_returned)
6855 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR)
6856 whats_returned = TREE_OPERAND (whats_returned, 0);
6861 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6863 whats_returned = TREE_OPERAND (whats_returned, 0);
6865 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6867 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6868 || TREE_CODE (whats_returned) == TARGET_EXPR)
6870 warning (0, "returning reference to temporary");
6873 if (TREE_CODE (whats_returned) == VAR_DECL
6874 && DECL_NAME (whats_returned)
6875 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6877 warning (0, "reference to non-lvalue returned");
6882 while (TREE_CODE (whats_returned) == COMPONENT_REF
6883 || TREE_CODE (whats_returned) == ARRAY_REF)
6884 whats_returned = TREE_OPERAND (whats_returned, 0);
6886 if (DECL_P (whats_returned)
6887 && DECL_NAME (whats_returned)
6888 && DECL_FUNCTION_SCOPE_P (whats_returned)
6889 && !(TREE_STATIC (whats_returned)
6890 || TREE_PUBLIC (whats_returned)))
6892 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6893 warning (0, "reference to local variable %q+D returned",
6896 warning (0, "address of local variable %q+D returned",
6902 /* Check that returning RETVAL from the current function is valid.
6903 Return an expression explicitly showing all conversions required to
6904 change RETVAL into the function return type, and to assign it to
6905 the DECL_RESULT for the function. Set *NO_WARNING to true if
6906 code reaches end of non-void function warning shouldn't be issued
6907 on this RETURN_EXPR. */
6910 check_return_expr (tree retval, bool *no_warning)
6913 /* The type actually returned by the function, after any
6916 int fn_returns_value_p;
6917 bool named_return_value_okay_p;
6919 *no_warning = false;
6921 /* A `volatile' function is one that isn't supposed to return, ever.
6922 (This is a G++ extension, used to get better code for functions
6923 that call the `volatile' function.) */
6924 if (TREE_THIS_VOLATILE (current_function_decl))
6925 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6927 /* Check for various simple errors. */
6928 if (DECL_DESTRUCTOR_P (current_function_decl))
6931 error ("returning a value from a destructor");
6934 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6936 if (in_function_try_handler)
6937 /* If a return statement appears in a handler of the
6938 function-try-block of a constructor, the program is ill-formed. */
6939 error ("cannot return from a handler of a function-try-block of a constructor");
6941 /* You can't return a value from a constructor. */
6942 error ("returning a value from a constructor");
6946 if (processing_template_decl)
6948 current_function_returns_value = 1;
6949 if (check_for_bare_parameter_packs (retval))
6950 retval = error_mark_node;
6954 /* When no explicit return-value is given in a function with a named
6955 return value, the named return value is used. */
6956 result = DECL_RESULT (current_function_decl);
6957 valtype = TREE_TYPE (result);
6958 gcc_assert (valtype != NULL_TREE);
6959 fn_returns_value_p = !VOID_TYPE_P (valtype);
6960 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6963 /* Check for a return statement with no return value in a function
6964 that's supposed to return a value. */
6965 if (!retval && fn_returns_value_p)
6967 permerror ("return-statement with no value, in function returning %qT",
6969 /* Clear this, so finish_function won't say that we reach the
6970 end of a non-void function (which we don't, we gave a
6972 current_function_returns_null = 0;
6973 /* And signal caller that TREE_NO_WARNING should be set on the
6974 RETURN_EXPR to avoid control reaches end of non-void function
6975 warnings in tree-cfg.c. */
6978 /* Check for a return statement with a value in a function that
6979 isn't supposed to return a value. */
6980 else if (retval && !fn_returns_value_p)
6982 if (VOID_TYPE_P (TREE_TYPE (retval)))
6983 /* You can return a `void' value from a function of `void'
6984 type. In that case, we have to evaluate the expression for
6985 its side-effects. */
6986 finish_expr_stmt (retval);
6988 permerror ("return-statement with a value, in function "
6989 "returning 'void'");
6991 current_function_returns_null = 1;
6993 /* There's really no value to return, after all. */
6997 /* Remember that this function can sometimes return without a
6999 current_function_returns_null = 1;
7001 /* Remember that this function did return a value. */
7002 current_function_returns_value = 1;
7004 /* Check for erroneous operands -- but after giving ourselves a
7005 chance to provide an error about returning a value from a void
7007 if (error_operand_p (retval))
7009 current_function_return_value = error_mark_node;
7010 return error_mark_node;
7013 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
7014 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
7015 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
7016 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
7018 && retval && null_ptr_cst_p (retval))
7019 warning (0, "%<operator new%> must not return NULL unless it is "
7020 "declared %<throw()%> (or -fcheck-new is in effect)");
7022 /* Effective C++ rule 15. See also start_function. */
7024 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
7028 /* The function return type must be a reference to the current
7030 if (TREE_CODE (valtype) == REFERENCE_TYPE
7031 && same_type_ignoring_top_level_qualifiers_p
7032 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
7034 /* Returning '*this' is obviously OK. */
7035 if (retval == current_class_ref)
7037 /* If we are calling a function whose return type is the same of
7038 the current class reference, it is ok. */
7039 else if (TREE_CODE (retval) == INDIRECT_REF
7040 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
7045 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
7048 /* The fabled Named Return Value optimization, as per [class.copy]/15:
7050 [...] For a function with a class return type, if the expression
7051 in the return statement is the name of a local object, and the cv-
7052 unqualified type of the local object is the same as the function
7053 return type, an implementation is permitted to omit creating the tem-
7054 porary object to hold the function return value [...]
7056 So, if this is a value-returning function that always returns the same
7057 local variable, remember it.
7059 It might be nice to be more flexible, and choose the first suitable
7060 variable even if the function sometimes returns something else, but
7061 then we run the risk of clobbering the variable we chose if the other
7062 returned expression uses the chosen variable somehow. And people expect
7063 this restriction, anyway. (jason 2000-11-19)
7065 See finish_function and finalize_nrv for the rest of this optimization. */
7067 named_return_value_okay_p =
7068 (retval != NULL_TREE
7069 /* Must be a local, automatic variable. */
7070 && TREE_CODE (retval) == VAR_DECL
7071 && DECL_CONTEXT (retval) == current_function_decl
7072 && ! TREE_STATIC (retval)
7073 && ! DECL_ANON_UNION_VAR_P (retval)
7074 && (DECL_ALIGN (retval)
7075 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
7076 /* The cv-unqualified type of the returned value must be the
7077 same as the cv-unqualified return type of the
7079 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
7081 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
7082 /* And the returned value must be non-volatile. */
7083 && ! TYPE_VOLATILE (TREE_TYPE (retval)));
7085 if (fn_returns_value_p && flag_elide_constructors)
7087 if (named_return_value_okay_p
7088 && (current_function_return_value == NULL_TREE
7089 || current_function_return_value == retval))
7090 current_function_return_value = retval;
7092 current_function_return_value = error_mark_node;
7095 /* We don't need to do any conversions when there's nothing being
7100 /* Do any required conversions. */
7101 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
7102 /* No conversions are required. */
7106 /* The type the function is declared to return. */
7107 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
7108 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
7110 /* The functype's return type will have been set to void, if it
7111 was an incomplete type. Just treat this as 'return;' */
7112 if (VOID_TYPE_P (functype))
7113 return error_mark_node;
7115 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
7116 treated as an rvalue for the purposes of overload resolution to
7117 favor move constructors over copy constructors. */
7118 if ((cxx_dialect != cxx98)
7119 && named_return_value_okay_p
7120 /* The variable must not have the `volatile' qualifier. */
7121 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
7122 /* The return type must be a class type. */
7123 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
7124 flags = flags | LOOKUP_PREFER_RVALUE;
7126 /* First convert the value to the function's return type, then
7127 to the type of return value's location to handle the
7128 case that functype is smaller than the valtype. */
7129 retval = convert_for_initialization
7130 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0,
7131 tf_warning_or_error);
7132 retval = convert (valtype, retval);
7134 /* If the conversion failed, treat this just like `return;'. */
7135 if (retval == error_mark_node)
7137 /* We can't initialize a register from a AGGR_INIT_EXPR. */
7138 else if (! cfun->returns_struct
7139 && TREE_CODE (retval) == TARGET_EXPR
7140 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
7141 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
7142 TREE_OPERAND (retval, 0));
7144 maybe_warn_about_returning_address_of_local (retval);
7147 /* Actually copy the value returned into the appropriate location. */
7148 if (retval && retval != result)
7149 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
7155 /* Returns nonzero if the pointer-type FROM can be converted to the
7156 pointer-type TO via a qualification conversion. If CONSTP is -1,
7157 then we return nonzero if the pointers are similar, and the
7158 cv-qualification signature of FROM is a proper subset of that of TO.
7160 If CONSTP is positive, then all outer pointers have been
7164 comp_ptr_ttypes_real (tree to, tree from, int constp)
7166 bool to_more_cv_qualified = false;
7168 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7170 if (TREE_CODE (to) != TREE_CODE (from))
7173 if (TREE_CODE (from) == OFFSET_TYPE
7174 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
7175 TYPE_OFFSET_BASETYPE (to)))
7178 /* Const and volatile mean something different for function types,
7179 so the usual checks are not appropriate. */
7180 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
7182 /* In Objective-C++, some types may have been 'volatilized' by
7183 the compiler for EH; when comparing them here, the volatile
7184 qualification must be ignored. */
7185 bool objc_quals_match = objc_type_quals_match (to, from);
7187 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
7190 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
7194 to_more_cv_qualified = true;
7198 constp &= TYPE_READONLY (to);
7201 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
7202 return ((constp >= 0 || to_more_cv_qualified)
7203 && same_type_ignoring_top_level_qualifiers_p (to, from));
7207 /* When comparing, say, char ** to char const **, this function takes
7208 the 'char *' and 'char const *'. Do not pass non-pointer/reference
7209 types to this function. */
7212 comp_ptr_ttypes (tree to, tree from)
7214 return comp_ptr_ttypes_real (to, from, 1);
7217 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
7218 type or inheritance-related types, regardless of cv-quals. */
7221 ptr_reasonably_similar (const_tree to, const_tree from)
7223 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7225 /* Any target type is similar enough to void. */
7226 if (TREE_CODE (to) == VOID_TYPE
7227 || TREE_CODE (from) == VOID_TYPE)
7230 if (TREE_CODE (to) != TREE_CODE (from))
7233 if (TREE_CODE (from) == OFFSET_TYPE
7234 && comptypes (TYPE_OFFSET_BASETYPE (to),
7235 TYPE_OFFSET_BASETYPE (from),
7236 COMPARE_BASE | COMPARE_DERIVED))
7239 if (TREE_CODE (to) == VECTOR_TYPE
7240 && vector_types_convertible_p (to, from, false))
7243 if (TREE_CODE (to) == INTEGER_TYPE
7244 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
7247 if (TREE_CODE (to) == FUNCTION_TYPE)
7250 if (TREE_CODE (to) != POINTER_TYPE)
7252 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
7253 COMPARE_BASE | COMPARE_DERIVED);
7257 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
7258 pointer-to-member types) are the same, ignoring cv-qualification at
7262 comp_ptr_ttypes_const (tree to, tree from)
7264 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7266 if (TREE_CODE (to) != TREE_CODE (from))
7269 if (TREE_CODE (from) == OFFSET_TYPE
7270 && same_type_p (TYPE_OFFSET_BASETYPE (from),
7271 TYPE_OFFSET_BASETYPE (to)))
7274 if (TREE_CODE (to) != POINTER_TYPE)
7275 return same_type_ignoring_top_level_qualifiers_p (to, from);
7279 /* Returns the type qualifiers for this type, including the qualifiers on the
7280 elements for an array type. */
7283 cp_type_quals (const_tree type)
7285 /* This CONST_CAST is okay because strip_array_types returns it's
7286 argument unmodified and we assign it to a const_tree. */
7287 type = strip_array_types (CONST_CAST_TREE(type));
7288 if (type == error_mark_node)
7289 return TYPE_UNQUALIFIED;
7290 return TYPE_QUALS (type);
7293 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
7297 cp_type_readonly (const_tree type)
7299 /* This CONST_CAST is okay because strip_array_types returns it's
7300 argument unmodified and we assign it to a const_tree. */
7301 type = strip_array_types (CONST_CAST_TREE(type));
7302 return TYPE_READONLY (type);
7305 /* Returns nonzero if the TYPE contains a mutable member. */
7308 cp_has_mutable_p (const_tree type)
7310 /* This CONST_CAST is okay because strip_array_types returns it's
7311 argument unmodified and we assign it to a const_tree. */
7312 type = strip_array_types (CONST_CAST_TREE(type));
7314 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
7317 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
7318 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
7319 approximation. In particular, consider:
7322 struct S { int i; };
7323 const S s = { f(); }
7325 Here, we will make "s" as TREE_READONLY (because it is declared
7326 "const") -- only to reverse ourselves upon seeing that the
7327 initializer is non-constant. */
7330 cp_apply_type_quals_to_decl (int type_quals, tree decl)
7332 tree type = TREE_TYPE (decl);
7334 if (type == error_mark_node)
7337 if (TREE_CODE (type) == FUNCTION_TYPE
7338 && type_quals != TYPE_UNQUALIFIED)
7340 /* This was an error in C++98 (cv-qualifiers cannot be added to
7341 a function type), but DR 295 makes the code well-formed by
7342 dropping the extra qualifiers. */
7345 tree bad_type = build_qualified_type (type, type_quals);
7346 pedwarn ("ignoring %qV qualifiers added to function type %qT",
7350 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
7354 /* Avoid setting TREE_READONLY incorrectly. */
7355 if (/* If the object has a constructor, the constructor may modify
7357 TYPE_NEEDS_CONSTRUCTING (type)
7358 /* If the type isn't complete, we don't know yet if it will need
7360 || !COMPLETE_TYPE_P (type)
7361 /* If the type has a mutable component, that component might be
7363 || TYPE_HAS_MUTABLE_P (type))
7364 type_quals &= ~TYPE_QUAL_CONST;
7366 c_apply_type_quals_to_decl (type_quals, decl);
7369 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7370 exemplar types such that casting T1 to T2 is casting away constness
7371 if and only if there is no implicit conversion from T1 to T2. */
7374 casts_away_constness_r (tree *t1, tree *t2)
7379 /* [expr.const.cast]
7381 For multi-level pointer to members and multi-level mixed pointers
7382 and pointers to members (conv.qual), the "member" aspect of a
7383 pointer to member level is ignored when determining if a const
7384 cv-qualifier has been cast away. */
7385 /* [expr.const.cast]
7387 For two pointer types:
7389 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7390 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7393 casting from X1 to X2 casts away constness if, for a non-pointer
7394 type T there does not exist an implicit conversion (clause
7397 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7401 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7402 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7403 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7405 *t1 = cp_build_qualified_type (void_type_node,
7406 cp_type_quals (*t1));
7407 *t2 = cp_build_qualified_type (void_type_node,
7408 cp_type_quals (*t2));
7412 quals1 = cp_type_quals (*t1);
7413 quals2 = cp_type_quals (*t2);
7415 if (TYPE_PTRMEM_P (*t1))
7416 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7418 *t1 = TREE_TYPE (*t1);
7419 if (TYPE_PTRMEM_P (*t2))
7420 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7422 *t2 = TREE_TYPE (*t2);
7424 casts_away_constness_r (t1, t2);
7425 *t1 = build_pointer_type (*t1);
7426 *t2 = build_pointer_type (*t2);
7427 *t1 = cp_build_qualified_type (*t1, quals1);
7428 *t2 = cp_build_qualified_type (*t2, quals2);
7431 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7435 casts_away_constness (tree t1, tree t2)
7437 if (TREE_CODE (t2) == REFERENCE_TYPE)
7439 /* [expr.const.cast]
7441 Casting from an lvalue of type T1 to an lvalue of type T2
7442 using a reference cast casts away constness if a cast from an
7443 rvalue of type "pointer to T1" to the type "pointer to T2"
7444 casts away constness. */
7445 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7446 return casts_away_constness (build_pointer_type (t1),
7447 build_pointer_type (TREE_TYPE (t2)));
7450 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7451 /* [expr.const.cast]
7453 Casting from an rvalue of type "pointer to data member of X
7454 of type T1" to the type "pointer to data member of Y of type
7455 T2" casts away constness if a cast from an rvalue of type
7456 "pointer to T1" to the type "pointer to T2" casts away
7458 return casts_away_constness
7459 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7460 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7462 /* Casting away constness is only something that makes sense for
7463 pointer or reference types. */
7464 if (TREE_CODE (t1) != POINTER_TYPE
7465 || TREE_CODE (t2) != POINTER_TYPE)
7468 /* Top-level qualifiers don't matter. */
7469 t1 = TYPE_MAIN_VARIANT (t1);
7470 t2 = TYPE_MAIN_VARIANT (t2);
7471 casts_away_constness_r (&t1, &t2);
7472 if (!can_convert (t2, t1))
7478 /* If T is a REFERENCE_TYPE return the type to which T refers.
7479 Otherwise, return T itself. */
7482 non_reference (tree t)
7484 if (TREE_CODE (t) == REFERENCE_TYPE)
7490 /* Return nonzero if REF is an lvalue valid for this language;
7491 otherwise, print an error message and return zero. USE says
7492 how the lvalue is being used and so selects the error message. */
7495 lvalue_or_else (const_tree ref, enum lvalue_use use, tsubst_flags_t complain)
7497 int win = lvalue_p (ref);
7499 if (!win && (complain & tf_error))