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 templ = member;
2320 if (BASELINK_P (templ))
2321 templ = lookup_template_function (templ, 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 (...)%>, e.g. %<(... ->* %E) (...)%>",
2854 original, original);
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 for errors in format strings and inappropriately
2892 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2895 return build_cxx_call (function, nargs, argarray);
2898 /* Convert the actual parameter expressions in the list VALUES
2899 to the types in the list TYPELIST.
2900 If parmdecls is exhausted, or when an element has NULL as its type,
2901 perform the default conversions.
2903 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2905 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2907 This is also where warnings about wrong number of args are generated.
2909 Returns the actual number of arguments processed (which might be less
2910 than NARGS), or -1 on error.
2912 VALUES is a chain of TREE_LIST nodes with the elements of the list
2913 in the TREE_VALUE slots of those nodes.
2915 In C++, unspecified trailing parameters can be filled in with their
2916 default arguments, if such were specified. Do so here. */
2919 convert_arguments (int nargs, tree *argarray,
2920 tree typelist, tree values, tree fndecl, int flags,
2921 tsubst_flags_t complain)
2923 tree typetail, valtail;
2924 const char *called_thing = 0;
2927 /* Argument passing is always copy-initialization. */
2928 flags |= LOOKUP_ONLYCONVERTING;
2932 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2934 if (DECL_NAME (fndecl) == NULL_TREE
2935 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2936 called_thing = "constructor";
2938 called_thing = "member function";
2941 called_thing = "function";
2944 for (valtail = values, typetail = typelist;
2946 valtail = TREE_CHAIN (valtail), i++)
2948 tree type = typetail ? TREE_VALUE (typetail) : 0;
2949 tree val = TREE_VALUE (valtail);
2951 if (val == error_mark_node || type == error_mark_node)
2954 if (type == void_type_node)
2956 if (complain & tf_error)
2960 error ("too many arguments to %s %q+#D",
2961 called_thing, fndecl);
2962 error ("at this point in file");
2965 error ("too many arguments to function");
2972 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2973 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2974 if (TREE_CODE (val) == NOP_EXPR
2975 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2976 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2977 val = TREE_OPERAND (val, 0);
2979 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2981 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2982 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2983 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2984 val = decay_conversion (val);
2987 if (val == error_mark_node)
2992 /* Formal parm type is specified by a function prototype. */
2995 if (!COMPLETE_TYPE_P (complete_type (type)))
2997 if (complain & tf_error)
3000 error ("parameter %P of %qD has incomplete type %qT",
3003 error ("parameter %P has incomplete type %qT", i, type);
3005 parmval = error_mark_node;
3009 parmval = convert_for_initialization
3010 (NULL_TREE, type, val, flags,
3011 "argument passing", fndecl, i, complain);
3012 parmval = convert_for_arg_passing (type, parmval);
3015 if (parmval == error_mark_node)
3018 argarray[i] = parmval;
3022 if (fndecl && DECL_BUILT_IN (fndecl)
3023 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
3024 /* Don't do ellipsis conversion for __built_in_constant_p
3025 as this will result in spurious warnings for non-POD
3027 val = require_complete_type (val);
3029 val = convert_arg_to_ellipsis (val);
3035 typetail = TREE_CHAIN (typetail);
3038 if (typetail != 0 && typetail != void_list_node)
3040 /* See if there are default arguments that can be used. Because
3041 we hold default arguments in the FUNCTION_TYPE (which is so
3042 wrong), we can see default parameters here from deduced
3043 contexts (and via typeof) for indirect function calls.
3044 Fortunately we know whether we have a function decl to
3045 provide default arguments in a language conformant
3047 if (fndecl && TREE_PURPOSE (typetail)
3048 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
3050 for (; typetail != void_list_node; ++i)
3053 = convert_default_arg (TREE_VALUE (typetail),
3054 TREE_PURPOSE (typetail),
3057 if (parmval == error_mark_node)
3060 argarray[i] = parmval;
3061 typetail = TREE_CHAIN (typetail);
3062 /* ends with `...'. */
3063 if (typetail == NULL_TREE)
3069 if (complain & tf_error)
3073 error ("too few arguments to %s %q+#D",
3074 called_thing, fndecl);
3075 error ("at this point in file");
3078 error ("too few arguments to function");
3084 gcc_assert (i <= nargs);
3088 /* Build a binary-operation expression, after performing default
3089 conversions on the operands. CODE is the kind of expression to
3090 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
3091 are the tree codes which correspond to ARG1 and ARG2 when issuing
3092 warnings about possibly misplaced parentheses. They may differ
3093 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
3094 folding (e.g., if the parser sees "a | 1 + 1", it may call this
3095 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
3096 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
3097 ARG2_CODE as ERROR_MARK. */
3100 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
3101 tree arg2, enum tree_code arg2_code, bool *overloaded_p,
3102 tsubst_flags_t complain)
3111 if (processing_template_decl)
3113 if (type_dependent_expression_p (arg1)
3114 || type_dependent_expression_p (arg2))
3115 return build_min_nt (code, arg1, arg2);
3116 arg1 = build_non_dependent_expr (arg1);
3117 arg2 = build_non_dependent_expr (arg2);
3120 if (code == DOTSTAR_EXPR)
3121 expr = build_m_component_ref (arg1, arg2);
3123 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3124 overloaded_p, complain);
3126 /* Check for cases such as x+y<<z which users are likely to
3127 misinterpret. But don't warn about obj << x + y, since that is a
3128 common idiom for I/O. */
3129 if (warn_parentheses
3130 && !processing_template_decl
3131 && !error_operand_p (arg1)
3132 && !error_operand_p (arg2)
3133 && (code != LSHIFT_EXPR
3134 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
3135 warn_about_parentheses (code, arg1_code, arg2_code);
3137 if (processing_template_decl && expr != error_mark_node)
3138 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
3143 /* For the c-common bits. */
3145 build_binary_op (enum tree_code code, tree op0, tree op1,
3146 int convert_p ATTRIBUTE_UNUSED)
3148 return cp_build_binary_op(code, op0, op1, tf_warning_or_error);
3152 /* Build a binary-operation expression without default conversions.
3153 CODE is the kind of expression to build.
3154 This function differs from `build' in several ways:
3155 the data type of the result is computed and recorded in it,
3156 warnings are generated if arg data types are invalid,
3157 special handling for addition and subtraction of pointers is known,
3158 and some optimization is done (operations on narrow ints
3159 are done in the narrower type when that gives the same result).
3160 Constant folding is also done before the result is returned.
3162 Note that the operands will never have enumeral types
3163 because either they have just had the default conversions performed
3164 or they have both just been converted to some other type in which
3165 the arithmetic is to be done.
3167 C++: must do special pointer arithmetic when implementing
3168 multiple inheritance, and deal with pointer to member functions. */
3171 cp_build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3172 tsubst_flags_t complain)
3175 enum tree_code code0, code1;
3177 const char *invalid_op_diag;
3179 /* Expression code to give to the expression when it is built.
3180 Normally this is CODE, which is what the caller asked for,
3181 but in some special cases we change it. */
3182 enum tree_code resultcode = code;
3184 /* Data type in which the computation is to be performed.
3185 In the simplest cases this is the common type of the arguments. */
3186 tree result_type = NULL;
3188 /* Nonzero means operands have already been type-converted
3189 in whatever way is necessary.
3190 Zero means they need to be converted to RESULT_TYPE. */
3193 /* Nonzero means create the expression with this type, rather than
3195 tree build_type = 0;
3197 /* Nonzero means after finally constructing the expression
3198 convert it to this type. */
3199 tree final_type = 0;
3203 /* Nonzero if this is an operation like MIN or MAX which can
3204 safely be computed in short if both args are promoted shorts.
3205 Also implies COMMON.
3206 -1 indicates a bitwise operation; this makes a difference
3207 in the exact conditions for when it is safe to do the operation
3208 in a narrower mode. */
3211 /* Nonzero if this is a comparison operation;
3212 if both args are promoted shorts, compare the original shorts.
3213 Also implies COMMON. */
3214 int short_compare = 0;
3216 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3219 /* True if both operands have arithmetic type. */
3220 bool arithmetic_types_p;
3222 /* Apply default conversions. */
3226 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3227 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3228 || code == TRUTH_XOR_EXPR)
3230 if (!really_overloaded_fn (op0))
3231 op0 = decay_conversion (op0);
3232 if (!really_overloaded_fn (op1))
3233 op1 = decay_conversion (op1);
3237 if (!really_overloaded_fn (op0))
3238 op0 = default_conversion (op0);
3239 if (!really_overloaded_fn (op1))
3240 op1 = default_conversion (op1);
3243 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3244 STRIP_TYPE_NOPS (op0);
3245 STRIP_TYPE_NOPS (op1);
3247 /* DTRT if one side is an overloaded function, but complain about it. */
3248 if (type_unknown_p (op0))
3250 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3251 if (t != error_mark_node)
3253 if (complain & tf_error)
3254 permerror ("assuming cast to type %qT from overloaded function",
3259 if (type_unknown_p (op1))
3261 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3262 if (t != error_mark_node)
3264 if (complain & tf_error)
3265 permerror ("assuming cast to type %qT from overloaded function",
3271 type0 = TREE_TYPE (op0);
3272 type1 = TREE_TYPE (op1);
3274 /* The expression codes of the data types of the arguments tell us
3275 whether the arguments are integers, floating, pointers, etc. */
3276 code0 = TREE_CODE (type0);
3277 code1 = TREE_CODE (type1);
3279 /* If an error was already reported for one of the arguments,
3280 avoid reporting another error. */
3282 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3283 return error_mark_node;
3285 if ((invalid_op_diag
3286 = targetm.invalid_binary_op (code, type0, type1)))
3288 error (invalid_op_diag);
3289 return error_mark_node;
3295 /* Subtraction of two similar pointers.
3296 We must subtract them as integers, then divide by object size. */
3297 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3298 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3300 return pointer_diff (op0, op1, common_type (type0, type1));
3301 /* In all other cases except pointer - int, the usual arithmetic
3303 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3308 /* The pointer - int case is just like pointer + int; fall
3311 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3312 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3316 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3317 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3318 if (processing_template_decl)
3320 result_type = TREE_TYPE (ptr_operand);
3323 return cp_pointer_int_sum (code,
3334 case TRUNC_DIV_EXPR:
3336 case FLOOR_DIV_EXPR:
3337 case ROUND_DIV_EXPR:
3338 case EXACT_DIV_EXPR:
3339 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3340 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3341 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3342 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3344 enum tree_code tcode0 = code0, tcode1 = code1;
3346 warn_for_div_by_zero (op1);
3348 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3349 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3350 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3351 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3353 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3354 resultcode = RDIV_EXPR;
3356 /* When dividing two signed integers, we have to promote to int.
3357 unless we divide by a constant != -1. Note that default
3358 conversion will have been performed on the operands at this
3359 point, so we have to dig out the original type to find out if
3361 shorten = ((TREE_CODE (op0) == NOP_EXPR
3362 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3363 || (TREE_CODE (op1) == INTEGER_CST
3364 && ! integer_all_onesp (op1)));
3373 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3374 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3375 && !VECTOR_FLOAT_TYPE_P (type0)
3376 && !VECTOR_FLOAT_TYPE_P (type1)))
3380 case TRUNC_MOD_EXPR:
3381 case FLOOR_MOD_EXPR:
3382 warn_for_div_by_zero (op1);
3384 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3386 /* Although it would be tempting to shorten always here, that loses
3387 on some targets, since the modulo instruction is undefined if the
3388 quotient can't be represented in the computation mode. We shorten
3389 only if unsigned or if dividing by something we know != -1. */
3390 shorten = ((TREE_CODE (op0) == NOP_EXPR
3391 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3392 || (TREE_CODE (op1) == INTEGER_CST
3393 && ! integer_all_onesp (op1)));
3398 case TRUTH_ANDIF_EXPR:
3399 case TRUTH_ORIF_EXPR:
3400 case TRUTH_AND_EXPR:
3402 result_type = boolean_type_node;
3405 /* Shift operations: result has same type as first operand;
3406 always convert second operand to int.
3407 Also set SHORT_SHIFT if shifting rightward. */
3410 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3412 result_type = type0;
3413 if (TREE_CODE (op1) == INTEGER_CST)
3415 if (tree_int_cst_lt (op1, integer_zero_node))
3417 if (complain & tf_warning)
3418 warning (0, "right shift count is negative");
3422 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0
3423 && (complain & tf_warning))
3424 warning (0, "right shift count >= width of type");
3427 /* Convert the shift-count to an integer, regardless of
3428 size of value being shifted. */
3429 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3430 op1 = cp_convert (integer_type_node, op1);
3431 /* Avoid converting op1 to result_type later. */
3437 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3439 result_type = type0;
3440 if (TREE_CODE (op1) == INTEGER_CST)
3442 if (tree_int_cst_lt (op1, integer_zero_node))
3444 if (complain & tf_warning)
3445 warning (0, "left shift count is negative");
3447 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3449 if (complain & tf_warning)
3450 warning (0, "left shift count >= width of type");
3453 /* Convert the shift-count to an integer, regardless of
3454 size of value being shifted. */
3455 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3456 op1 = cp_convert (integer_type_node, op1);
3457 /* Avoid converting op1 to result_type later. */
3464 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3466 result_type = type0;
3467 if (TREE_CODE (op1) == INTEGER_CST)
3469 if (tree_int_cst_lt (op1, integer_zero_node))
3471 if (complain & tf_warning)
3472 warning (0, (code == LROTATE_EXPR)
3473 ? G_("left rotate count is negative")
3474 : G_("right rotate count is negative"));
3476 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3478 if (complain & tf_warning)
3479 warning (0, (code == LROTATE_EXPR)
3480 ? G_("left rotate count >= width of type")
3481 : G_("right rotate count >= width of type"));
3484 /* Convert the shift-count to an integer, regardless of
3485 size of value being shifted. */
3486 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3487 op1 = cp_convert (integer_type_node, op1);
3493 if ((complain & tf_warning)
3494 && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1)))
3495 warning (OPT_Wfloat_equal,
3496 "comparing floating point with == or != is unsafe");
3497 if ((complain & tf_warning)
3498 && ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3499 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0))))
3500 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3502 build_type = boolean_type_node;
3503 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3504 || code0 == COMPLEX_TYPE)
3505 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3506 || code1 == COMPLEX_TYPE))
3508 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3509 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3510 result_type = composite_pointer_type (type0, type1, op0, op1,
3511 "comparison", complain);
3512 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3513 && null_ptr_cst_p (op1))
3515 if (TREE_CODE (op0) == ADDR_EXPR
3516 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3518 if (complain & tf_warning)
3519 warning (OPT_Waddress, "the address of %qD will never be NULL",
3520 TREE_OPERAND (op0, 0));
3522 result_type = type0;
3524 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3525 && null_ptr_cst_p (op0))
3527 if (TREE_CODE (op1) == ADDR_EXPR
3528 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3530 if (complain & tf_warning)
3531 warning (OPT_Waddress, "the address of %qD will never be NULL",
3532 TREE_OPERAND (op1, 0));
3534 result_type = type1;
3536 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3538 result_type = type0;
3539 if (complain & tf_error)
3540 permerror ("ISO C++ forbids comparison between pointer and integer");
3542 return error_mark_node;
3544 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3546 result_type = type1;
3547 if (complain & tf_error)
3548 permerror ("ISO C++ forbids comparison between pointer and integer");
3550 return error_mark_node;
3552 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3554 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3555 == ptrmemfunc_vbit_in_delta)
3557 tree pfn0 = pfn_from_ptrmemfunc (op0);
3558 tree delta0 = delta_from_ptrmemfunc (op0);
3559 tree e1 = cp_build_binary_op (EQ_EXPR,
3561 fold_convert (TREE_TYPE (pfn0),
3564 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3568 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3570 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2,
3572 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3576 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3577 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3579 result_type = TREE_TYPE (op0);
3581 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3582 return cp_build_binary_op (code, op1, op0, complain);
3583 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1))
3586 /* E will be the final comparison. */
3588 /* E1 and E2 are for scratch. */
3596 type = composite_pointer_type (type0, type1, op0, op1, "comparison",
3599 if (!same_type_p (TREE_TYPE (op0), type))
3600 op0 = cp_convert_and_check (type, op0);
3601 if (!same_type_p (TREE_TYPE (op1), type))
3602 op1 = cp_convert_and_check (type, op1);
3604 if (op0 == error_mark_node || op1 == error_mark_node)
3605 return error_mark_node;
3607 if (TREE_SIDE_EFFECTS (op0))
3608 op0 = save_expr (op0);
3609 if (TREE_SIDE_EFFECTS (op1))
3610 op1 = save_expr (op1);
3612 pfn0 = pfn_from_ptrmemfunc (op0);
3613 pfn1 = pfn_from_ptrmemfunc (op1);
3614 delta0 = delta_from_ptrmemfunc (op0);
3615 delta1 = delta_from_ptrmemfunc (op1);
3616 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3617 == ptrmemfunc_vbit_in_delta)
3622 && ((op0.delta == op1.delta)
3623 || (!op0.pfn && op0.delta & 1 == 0
3624 && op1.delta & 1 == 0))
3626 The reason for the `!op0.pfn' bit is that a NULL
3627 pointer-to-member is any member with a zero PFN and
3628 LSB of the DELTA field is 0. */
3630 e1 = cp_build_binary_op (BIT_AND_EXPR,
3634 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node,
3636 e2 = cp_build_binary_op (BIT_AND_EXPR,
3640 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3642 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1,
3644 e2 = cp_build_binary_op (EQ_EXPR,
3646 fold_convert (TREE_TYPE (pfn0),
3649 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3650 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3651 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3658 && (!op0.pfn || op0.delta == op1.delta))
3660 The reason for the `!op0.pfn' bit is that a NULL
3661 pointer-to-member is any member with a zero PFN; the
3662 DELTA field is unspecified. */
3664 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3665 e2 = cp_build_binary_op (EQ_EXPR,
3667 fold_convert (TREE_TYPE (pfn0),
3670 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3672 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3673 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3674 if (code == EQ_EXPR)
3676 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node, complain);
3680 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3681 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3683 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3684 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3692 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3693 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3695 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3696 result_type = composite_pointer_type (type0, type1, op0, op1,
3697 "comparison", complain);
3704 if (TREE_CODE (orig_op0) == STRING_CST
3705 || TREE_CODE (orig_op1) == STRING_CST)
3707 if (complain & tf_warning)
3708 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3711 build_type = boolean_type_node;
3712 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3713 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3715 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3716 result_type = composite_pointer_type (type0, type1, op0, op1,
3717 "comparison", complain);
3718 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3719 && integer_zerop (op1))
3720 result_type = type0;
3721 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3722 && integer_zerop (op0))
3723 result_type = type1;
3724 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3726 result_type = type0;
3727 if (complain & tf_error)
3728 permerror ("ISO C++ forbids comparison between pointer and integer");
3730 return error_mark_node;
3732 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3734 result_type = type1;
3735 if (complain & tf_error)
3736 permerror ("ISO C++ forbids comparison between pointer and integer");
3738 return error_mark_node;
3742 case UNORDERED_EXPR:
3749 build_type = integer_type_node;
3750 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3752 if (complain & tf_error)
3753 error ("unordered comparison on non-floating point argument");
3754 return error_mark_node;
3763 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3764 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3765 || code1 == COMPLEX_TYPE)))
3766 arithmetic_types_p = 1;
3769 arithmetic_types_p = 0;
3770 /* Vector arithmetic is only allowed when both sides are vectors. */
3771 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3773 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3774 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3777 binary_op_error (code, type0, type1);
3778 return error_mark_node;
3780 arithmetic_types_p = 1;
3783 /* Determine the RESULT_TYPE, if it is not already known. */
3785 && arithmetic_types_p
3786 && (shorten || common || short_compare))
3787 result_type = common_type (type0, type1);
3791 if (complain & tf_error)
3792 error ("invalid operands of types %qT and %qT to binary %qO",
3793 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3794 return error_mark_node;
3797 /* If we're in a template, the only thing we need to know is the
3799 if (processing_template_decl)
3801 /* Since the middle-end checks the type when doing a build2, we
3802 need to build the tree in pieces. This built tree will never
3803 get out of the front-end as we replace it when instantiating
3805 tree tmp = build2 (resultcode,
3806 build_type ? build_type : result_type,
3808 TREE_OPERAND (tmp, 0) = op0;
3812 if (arithmetic_types_p)
3814 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3816 /* For certain operations (which identify themselves by shorten != 0)
3817 if both args were extended from the same smaller type,
3818 do the arithmetic in that type and then extend.
3820 shorten !=0 and !=1 indicates a bitwise operation.
3821 For them, this optimization is safe only if
3822 both args are zero-extended or both are sign-extended.
3823 Otherwise, we might change the result.
3824 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3825 but calculated in (unsigned short) it would be (unsigned short)-1. */
3827 if (shorten && none_complex)
3829 int unsigned0, unsigned1;
3830 tree arg0 = get_narrower (op0, &unsigned0);
3831 tree arg1 = get_narrower (op1, &unsigned1);
3832 /* UNS is 1 if the operation to be done is an unsigned one. */
3833 int uns = TYPE_UNSIGNED (result_type);
3836 final_type = result_type;
3838 /* Handle the case that OP0 does not *contain* a conversion
3839 but it *requires* conversion to FINAL_TYPE. */
3841 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3842 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3843 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3844 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3846 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3848 /* For bitwise operations, signedness of nominal type
3849 does not matter. Consider only how operands were extended. */
3853 /* Note that in all three cases below we refrain from optimizing
3854 an unsigned operation on sign-extended args.
3855 That would not be valid. */
3857 /* Both args variable: if both extended in same way
3858 from same width, do it in that width.
3859 Do it unsigned if args were zero-extended. */
3860 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3861 < TYPE_PRECISION (result_type))
3862 && (TYPE_PRECISION (TREE_TYPE (arg1))
3863 == TYPE_PRECISION (TREE_TYPE (arg0)))
3864 && unsigned0 == unsigned1
3865 && (unsigned0 || !uns))
3866 result_type = c_common_signed_or_unsigned_type
3867 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3868 else if (TREE_CODE (arg0) == INTEGER_CST
3869 && (unsigned1 || !uns)
3870 && (TYPE_PRECISION (TREE_TYPE (arg1))
3871 < TYPE_PRECISION (result_type))
3872 && (type = c_common_signed_or_unsigned_type
3873 (unsigned1, TREE_TYPE (arg1)),
3874 int_fits_type_p (arg0, type)))
3876 else if (TREE_CODE (arg1) == INTEGER_CST
3877 && (unsigned0 || !uns)
3878 && (TYPE_PRECISION (TREE_TYPE (arg0))
3879 < TYPE_PRECISION (result_type))
3880 && (type = c_common_signed_or_unsigned_type
3881 (unsigned0, TREE_TYPE (arg0)),
3882 int_fits_type_p (arg1, type)))
3886 /* Comparison operations are shortened too but differently.
3887 They identify themselves by setting short_compare = 1. */
3891 /* Don't write &op0, etc., because that would prevent op0
3892 from being kept in a register.
3893 Instead, make copies of the our local variables and
3894 pass the copies by reference, then copy them back afterward. */
3895 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3896 enum tree_code xresultcode = resultcode;
3898 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3900 return cp_convert (boolean_type_node, val);
3901 op0 = xop0, op1 = xop1;
3903 resultcode = xresultcode;
3906 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3907 && warn_sign_compare
3908 /* Do not warn until the template is instantiated; we cannot
3909 bound the ranges of the arguments until that point. */
3910 && !processing_template_decl)
3912 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3913 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3915 int unsignedp0, unsignedp1;
3916 tree primop0 = get_narrower (op0, &unsignedp0);
3917 tree primop1 = get_narrower (op1, &unsignedp1);
3919 /* Check for comparison of different enum types. */
3920 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3921 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3922 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3923 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1))
3924 && (complain & tf_warning))
3926 warning (OPT_Wsign_compare, "comparison between types %q#T and %q#T",
3927 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3930 /* Give warnings for comparisons between signed and unsigned
3931 quantities that may fail. */
3932 /* Do the checking based on the original operand trees, so that
3933 casts will be considered, but default promotions won't be. */
3935 /* Do not warn if the comparison is being done in a signed type,
3936 since the signed type will only be chosen if it can represent
3937 all the values of the unsigned type. */
3938 if (!TYPE_UNSIGNED (result_type))
3940 /* Do not warn if both operands are unsigned. */
3941 else if (op0_signed == op1_signed)
3943 /* Do not warn if the signed quantity is an unsuffixed
3944 integer literal (or some static constant expression
3945 involving such literals or a conditional expression
3946 involving such literals) and it is non-negative. */
3947 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3948 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3950 /* Do not warn if the comparison is an equality operation,
3951 the unsigned quantity is an integral constant and it does
3952 not use the most significant bit of result_type. */
3953 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3954 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3955 && int_fits_type_p (orig_op1, c_common_signed_type
3957 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3958 && int_fits_type_p (orig_op0, c_common_signed_type
3961 else if (complain & tf_warning)
3962 warning (OPT_Wsign_compare,
3963 "comparison between signed and unsigned integer expressions");
3965 /* Warn if two unsigned values are being compared in a size
3966 larger than their original size, and one (and only one) is the
3967 result of a `~' operator. This comparison will always fail.
3969 Also warn if one operand is a constant, and the constant does not
3970 have all bits set that are set in the ~ operand when it is
3973 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3974 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3976 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3977 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3978 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3979 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3981 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3984 HOST_WIDE_INT constant, mask;
3988 if (host_integerp (primop0, 0))
3991 unsignedp = unsignedp1;
3992 constant = tree_low_cst (primop0, 0);
3997 unsignedp = unsignedp0;
3998 constant = tree_low_cst (primop1, 0);
4001 bits = TYPE_PRECISION (TREE_TYPE (primop));
4002 if (bits < TYPE_PRECISION (result_type)
4003 && bits < HOST_BITS_PER_LONG && unsignedp)
4005 mask = (~ (HOST_WIDE_INT) 0) << bits;
4006 if ((mask & constant) != mask
4007 && (complain & tf_warning))
4008 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with constant");
4011 else if (unsignedp0 && unsignedp1
4012 && (TYPE_PRECISION (TREE_TYPE (primop0))
4013 < TYPE_PRECISION (result_type))
4014 && (TYPE_PRECISION (TREE_TYPE (primop1))
4015 < TYPE_PRECISION (result_type))
4016 && (complain & tf_warning))
4017 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with unsigned");
4022 /* Issue warnings about peculiar, but valid, uses of NULL. */
4023 if ((orig_op0 == null_node || orig_op1 == null_node)
4024 /* It's reasonable to use pointer values as operands of &&
4025 and ||, so NULL is no exception. */
4026 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
4027 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
4028 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
4029 && code != EQ_EXPR && code != NE_EXPR)
4030 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
4031 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
4032 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE))
4033 && (complain & tf_warning))
4034 /* Some sort of arithmetic operation involving NULL was
4035 performed. Note that pointer-difference and pointer-addition
4036 have already been handled above, and so we don't end up here in
4038 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
4041 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
4042 Then the expression will be built.
4043 It will be given type FINAL_TYPE if that is nonzero;
4044 otherwise, it will be given type RESULT_TYPE. */
4047 if (TREE_TYPE (op0) != result_type)
4048 op0 = cp_convert_and_check (result_type, op0);
4049 if (TREE_TYPE (op1) != result_type)
4050 op1 = cp_convert_and_check (result_type, op1);
4052 if (op0 == error_mark_node || op1 == error_mark_node)
4053 return error_mark_node;
4056 if (build_type == NULL_TREE)
4057 build_type = result_type;
4059 result = build2 (resultcode, build_type, op0, op1);
4060 result = fold_if_not_in_template (result);
4061 if (final_type != 0)
4062 result = cp_convert (final_type, result);
4064 if (TREE_OVERFLOW_P (result)
4065 && !TREE_OVERFLOW_P (op0)
4066 && !TREE_OVERFLOW_P (op1))
4067 overflow_warning (result);
4072 /* Return a tree for the sum or difference (RESULTCODE says which)
4073 of pointer PTROP and integer INTOP. */
4076 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
4078 tree res_type = TREE_TYPE (ptrop);
4080 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
4081 in certain circumstance (when it's valid to do so). So we need
4082 to make sure it's complete. We don't need to check here, if we
4083 can actually complete it at all, as those checks will be done in
4084 pointer_int_sum() anyway. */
4085 complete_type (TREE_TYPE (res_type));
4087 return pointer_int_sum (resultcode, ptrop,
4088 fold_if_not_in_template (intop));
4091 /* Return a tree for the difference of pointers OP0 and OP1.
4092 The resulting tree has type int. */
4095 pointer_diff (tree op0, tree op1, tree ptrtype)
4098 tree restype = ptrdiff_type_node;
4099 tree target_type = TREE_TYPE (ptrtype);
4101 if (!complete_type_or_else (target_type, NULL_TREE))
4102 return error_mark_node;
4104 if (pedantic || warn_pointer_arith)
4106 if (TREE_CODE (target_type) == VOID_TYPE)
4107 permerror ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
4108 if (TREE_CODE (target_type) == FUNCTION_TYPE)
4109 permerror ("ISO C++ forbids using pointer to a function in subtraction");
4110 if (TREE_CODE (target_type) == METHOD_TYPE)
4111 permerror ("ISO C++ forbids using pointer to a method in subtraction");
4114 /* First do the subtraction as integers;
4115 then drop through to build the divide operator. */
4117 op0 = cp_build_binary_op (MINUS_EXPR,
4118 cp_convert (restype, op0),
4119 cp_convert (restype, op1),
4120 tf_warning_or_error);
4122 /* This generates an error if op1 is a pointer to an incomplete type. */
4123 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
4124 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
4126 op1 = (TYPE_PTROB_P (ptrtype)
4127 ? size_in_bytes (target_type)
4128 : integer_one_node);
4130 /* Do the division. */
4132 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
4133 return fold_if_not_in_template (result);
4136 /* Construct and perhaps optimize a tree representation
4137 for a unary operation. CODE, a tree_code, specifies the operation
4138 and XARG is the operand. */
4141 build_x_unary_op (enum tree_code code, tree xarg, tsubst_flags_t complain)
4143 tree orig_expr = xarg;
4147 if (processing_template_decl)
4149 if (type_dependent_expression_p (xarg))
4150 return build_min_nt (code, xarg, NULL_TREE);
4152 xarg = build_non_dependent_expr (xarg);
4157 /* [expr.unary.op] says:
4159 The address of an object of incomplete type can be taken.
4161 (And is just the ordinary address operator, not an overloaded
4162 "operator &".) However, if the type is a template
4163 specialization, we must complete the type at this point so that
4164 an overloaded "operator &" will be available if required. */
4165 if (code == ADDR_EXPR
4166 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
4167 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
4168 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
4169 || (TREE_CODE (xarg) == OFFSET_REF)))
4170 /* Don't look for a function. */;
4172 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
4173 /*overloaded_p=*/NULL, complain);
4174 if (!exp && code == ADDR_EXPR)
4176 /* A pointer to member-function can be formed only by saying
4178 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
4179 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
4181 if (TREE_CODE (xarg) != OFFSET_REF
4182 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4184 error ("invalid use of %qE to form a pointer-to-member-function",
4186 if (TREE_CODE (xarg) != OFFSET_REF)
4187 inform (" a qualified-id is required");
4188 return error_mark_node;
4192 error ("parentheses around %qE cannot be used to form a"
4193 " pointer-to-member-function",
4195 PTRMEM_OK_P (xarg) = 1;
4199 if (TREE_CODE (xarg) == OFFSET_REF)
4201 ptrmem = PTRMEM_OK_P (xarg);
4203 if (!ptrmem && !flag_ms_extensions
4204 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4206 /* A single non-static member, make sure we don't allow a
4207 pointer-to-member. */
4208 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4209 TREE_OPERAND (xarg, 0),
4210 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4211 PTRMEM_OK_P (xarg) = ptrmem;
4214 else if (TREE_CODE (xarg) == TARGET_EXPR && (complain & tf_warning))
4215 warning (0, "taking address of temporary");
4216 exp = cp_build_unary_op (ADDR_EXPR, xarg, 0, complain);
4219 if (processing_template_decl && exp != error_mark_node)
4220 exp = build_min_non_dep (code, exp, orig_expr,
4221 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4222 if (TREE_CODE (exp) == ADDR_EXPR)
4223 PTRMEM_OK_P (exp) = ptrmem;
4227 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4228 constants, where a null value is represented by an INTEGER_CST of
4232 cp_truthvalue_conversion (tree expr)
4234 tree type = TREE_TYPE (expr);
4235 if (TYPE_PTRMEM_P (type))
4236 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4238 return c_common_truthvalue_conversion (expr);
4241 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4244 condition_conversion (tree expr)
4247 if (processing_template_decl)
4249 t = perform_implicit_conversion (boolean_type_node, expr,
4250 tf_warning_or_error);
4251 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4255 /* Return an ADDR_EXPR giving the address of T. This function
4256 attempts no optimizations or simplifications; it is a low-level
4260 build_address (tree t)
4264 if (error_operand_p (t) || !cxx_mark_addressable (t))
4265 return error_mark_node;
4267 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4272 /* Return a NOP_EXPR converting EXPR to TYPE. */
4275 build_nop (tree type, tree expr)
4277 if (type == error_mark_node || error_operand_p (expr))
4279 return build1 (NOP_EXPR, type, expr);
4282 /* C++: Must handle pointers to members.
4284 Perhaps type instantiation should be extended to handle conversion
4285 from aggregates to types we don't yet know we want? (Or are those
4286 cases typically errors which should be reported?)
4288 NOCONVERT nonzero suppresses the default promotions
4289 (such as from short to int). */
4292 cp_build_unary_op (enum tree_code code, tree xarg, int noconvert,
4293 tsubst_flags_t complain)
4295 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4298 const char *errstring = NULL;
4300 const char *invalid_op_diag;
4302 if (arg == error_mark_node)
4303 return error_mark_node;
4305 if ((invalid_op_diag
4306 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4311 error (invalid_op_diag);
4312 return error_mark_node;
4317 case UNARY_PLUS_EXPR:
4320 int flags = WANT_ARITH | WANT_ENUM;
4321 /* Unary plus (but not unary minus) is allowed on pointers. */
4322 if (code == UNARY_PLUS_EXPR)
4323 flags |= WANT_POINTER;
4324 arg = build_expr_type_conversion (flags, arg, true);
4326 errstring = (code == NEGATE_EXPR
4327 ? "wrong type argument to unary minus"
4328 : "wrong type argument to unary plus");
4331 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4332 arg = perform_integral_promotions (arg);
4334 /* Make sure the result is not an lvalue: a unary plus or minus
4335 expression is always a rvalue. */
4342 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4346 arg = default_conversion (arg);
4348 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4351 errstring = "wrong type argument to bit-complement";
4352 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4353 arg = perform_integral_promotions (arg);
4357 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4358 errstring = "wrong type argument to abs";
4359 else if (!noconvert)
4360 arg = default_conversion (arg);
4364 /* Conjugating a real value is a no-op, but allow it anyway. */
4365 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4366 errstring = "wrong type argument to conjugation";
4367 else if (!noconvert)
4368 arg = default_conversion (arg);
4371 case TRUTH_NOT_EXPR:
4372 arg = perform_implicit_conversion (boolean_type_node, arg,
4374 val = invert_truthvalue (arg);
4375 if (arg != error_mark_node)
4377 errstring = "in argument to unary !";
4384 if (TREE_CODE (arg) == COMPLEX_CST)
4385 return TREE_REALPART (arg);
4386 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4388 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4389 return fold_if_not_in_template (arg);
4395 if (TREE_CODE (arg) == COMPLEX_CST)
4396 return TREE_IMAGPART (arg);
4397 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4399 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4400 return fold_if_not_in_template (arg);
4403 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4405 case PREINCREMENT_EXPR:
4406 case POSTINCREMENT_EXPR:
4407 case PREDECREMENT_EXPR:
4408 case POSTDECREMENT_EXPR:
4409 /* Handle complex lvalues (when permitted)
4410 by reduction to simpler cases. */
4412 val = unary_complex_lvalue (code, arg);
4416 /* Increment or decrement the real part of the value,
4417 and don't change the imaginary part. */
4418 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4422 arg = stabilize_reference (arg);
4423 real = cp_build_unary_op (REALPART_EXPR, arg, 1, complain);
4424 imag = cp_build_unary_op (IMAGPART_EXPR, arg, 1, complain);
4425 real = cp_build_unary_op (code, real, 1, complain);
4426 if (real == error_mark_node || imag == error_mark_node)
4427 return error_mark_node;
4428 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4432 /* Report invalid types. */
4434 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4437 if (code == PREINCREMENT_EXPR)
4438 errstring ="no pre-increment operator for type";
4439 else if (code == POSTINCREMENT_EXPR)
4440 errstring ="no post-increment operator for type";
4441 else if (code == PREDECREMENT_EXPR)
4442 errstring ="no pre-decrement operator for type";
4444 errstring ="no post-decrement operator for type";
4447 else if (arg == error_mark_node)
4448 return error_mark_node;
4450 /* Report something read-only. */
4452 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4453 || TREE_READONLY (arg))
4455 if (complain & tf_error)
4456 readonly_error (arg, ((code == PREINCREMENT_EXPR
4457 || code == POSTINCREMENT_EXPR)
4458 ? "increment" : "decrement"));
4460 return error_mark_node;
4466 tree result_type = TREE_TYPE (arg);
4468 declared_type = unlowered_expr_type (arg);
4470 arg = get_unwidened (arg, 0);
4471 argtype = TREE_TYPE (arg);
4473 /* ARM $5.2.5 last annotation says this should be forbidden. */
4474 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4476 if (complain & tf_error)
4477 permerror ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4478 ? G_("ISO C++ forbids incrementing an enum")
4479 : G_("ISO C++ forbids decrementing an enum"));
4481 return error_mark_node;
4484 /* Compute the increment. */
4486 if (TREE_CODE (argtype) == POINTER_TYPE)
4488 tree type = complete_type (TREE_TYPE (argtype));
4490 if (!COMPLETE_OR_VOID_TYPE_P (type))
4492 if (complain & tf_error)
4493 error (((code == PREINCREMENT_EXPR
4494 || code == POSTINCREMENT_EXPR))
4495 ? G_("cannot increment a pointer to incomplete type %qT")
4496 : G_("cannot decrement a pointer to incomplete type %qT"),
4497 TREE_TYPE (argtype));
4499 return error_mark_node;
4501 else if ((pedantic || warn_pointer_arith)
4502 && !TYPE_PTROB_P (argtype))
4504 if (complain & tf_error)
4505 permerror ((code == PREINCREMENT_EXPR
4506 || code == POSTINCREMENT_EXPR)
4507 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4508 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4511 return error_mark_node;
4514 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4517 inc = integer_one_node;
4519 inc = cp_convert (argtype, inc);
4521 /* Complain about anything else that is not a true lvalue. */
4522 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4523 || code == POSTINCREMENT_EXPR)
4524 ? lv_increment : lv_decrement),
4526 return error_mark_node;
4528 /* Forbid using -- on `bool'. */
4529 if (same_type_p (declared_type, boolean_type_node))
4531 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4533 if (complain & tf_error)
4534 error ("invalid use of Boolean expression as operand "
4535 "to %<operator--%>");
4536 return error_mark_node;
4538 val = boolean_increment (code, arg);
4541 val = build2 (code, TREE_TYPE (arg), arg, inc);
4543 TREE_SIDE_EFFECTS (val) = 1;
4544 return cp_convert (result_type, val);
4548 /* Note that this operation never does default_conversion
4549 regardless of NOCONVERT. */
4551 argtype = lvalue_type (arg);
4553 if (TREE_CODE (arg) == OFFSET_REF)
4556 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4558 tree type = build_pointer_type (TREE_TYPE (argtype));
4559 arg = build1 (CONVERT_EXPR, type, arg);
4562 else if (pedantic && DECL_MAIN_P (arg))
4565 if (complain & tf_error)
4566 permerror ("ISO C++ forbids taking address of function %<::main%>");
4568 return error_mark_node;
4571 /* Let &* cancel out to simplify resulting code. */
4572 if (TREE_CODE (arg) == INDIRECT_REF)
4574 /* We don't need to have `current_class_ptr' wrapped in a
4575 NON_LVALUE_EXPR node. */
4576 if (arg == current_class_ref)
4577 return current_class_ptr;
4579 arg = TREE_OPERAND (arg, 0);
4580 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4582 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4583 arg = build1 (CONVERT_EXPR, type, arg);
4586 /* Don't let this be an lvalue. */
4591 /* Uninstantiated types are all functions. Taking the
4592 address of a function is a no-op, so just return the
4595 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4596 || !IDENTIFIER_OPNAME_P (arg));
4598 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4599 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4601 /* They're trying to take the address of a unique non-static
4602 member function. This is ill-formed (except in MS-land),
4603 but let's try to DTRT.
4604 Note: We only handle unique functions here because we don't
4605 want to complain if there's a static overload; non-unique
4606 cases will be handled by instantiate_type. But we need to
4607 handle this case here to allow casts on the resulting PMF.
4608 We could defer this in non-MS mode, but it's easier to give
4609 a useful error here. */
4611 /* Inside constant member functions, the `this' pointer
4612 contains an extra const qualifier. TYPE_MAIN_VARIANT
4613 is used here to remove this const from the diagnostics
4614 and the created OFFSET_REF. */
4615 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4616 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4619 if (! flag_ms_extensions)
4621 tree name = DECL_NAME (fn);
4622 if (!(complain & tf_error))
4623 return error_mark_node;
4624 else if (current_class_type
4625 && TREE_OPERAND (arg, 0) == current_class_ref)
4626 /* An expression like &memfn. */
4627 permerror ("ISO C++ forbids taking the address of an unqualified"
4628 " or parenthesized non-static member function to form"
4629 " a pointer to member function. Say %<&%T::%D%>",
4632 permerror ("ISO C++ forbids taking the address of a bound member"
4633 " function to form a pointer to member function."
4637 arg = build_offset_ref (base, fn, /*address_p=*/true);
4641 if (type_unknown_p (arg))
4642 return build1 (ADDR_EXPR, unknown_type_node, arg);
4644 /* Handle complex lvalues (when permitted)
4645 by reduction to simpler cases. */
4646 val = unary_complex_lvalue (code, arg);
4650 switch (TREE_CODE (arg))
4654 case FIX_TRUNC_EXPR:
4655 /* Even if we're not being pedantic, we cannot allow this
4656 extension when we're instantiating in a SFINAE
4658 if (! lvalue_p (arg) && (pedantic || complain == tf_none))
4660 if (complain & tf_error)
4661 permerror ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4663 return error_mark_node;
4668 arg = BASELINK_FUNCTIONS (arg);
4672 arg = OVL_CURRENT (arg);
4676 /* Turn a reference to a non-static data member into a
4677 pointer-to-member. */
4682 if (!PTRMEM_OK_P (arg))
4683 return cp_build_unary_op (code, arg, 0, complain);
4685 t = TREE_OPERAND (arg, 1);
4686 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4688 if (complain & tf_error)
4689 error ("cannot create pointer to reference member %qD", t);
4690 return error_mark_node;
4693 type = build_ptrmem_type (context_for_name_lookup (t),
4695 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4703 /* Anything not already handled and not a true memory reference
4705 if (TREE_CODE (argtype) != FUNCTION_TYPE
4706 && TREE_CODE (argtype) != METHOD_TYPE
4707 && TREE_CODE (arg) != OFFSET_REF
4708 && !lvalue_or_else (arg, lv_addressof, complain))
4709 return error_mark_node;
4711 if (argtype != error_mark_node)
4712 argtype = build_pointer_type (argtype);
4714 /* In a template, we are processing a non-dependent expression
4715 so we can just form an ADDR_EXPR with the correct type. */
4716 if (processing_template_decl)
4718 val = build_address (arg);
4719 if (TREE_CODE (arg) == OFFSET_REF)
4720 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4724 if (TREE_CODE (arg) != COMPONENT_REF)
4726 val = build_address (arg);
4727 if (TREE_CODE (arg) == OFFSET_REF)
4728 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4730 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4732 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4734 /* We can only get here with a single static member
4736 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4737 && DECL_STATIC_FUNCTION_P (fn));
4739 val = build_address (fn);
4740 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4741 /* Do not lose object's side effects. */
4742 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4743 TREE_OPERAND (arg, 0), val);
4745 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4747 if (complain & tf_error)
4748 error ("attempt to take address of bit-field structure member %qD",
4749 TREE_OPERAND (arg, 1));
4750 return error_mark_node;
4754 tree object = TREE_OPERAND (arg, 0);
4755 tree field = TREE_OPERAND (arg, 1);
4756 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4757 (TREE_TYPE (object), decl_type_context (field)));
4758 val = build_address (arg);
4761 if (TREE_CODE (argtype) == POINTER_TYPE
4762 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4764 build_ptrmemfunc_type (argtype);
4765 val = build_ptrmemfunc (argtype, val, 0,
4766 /*c_cast_p=*/false);
4778 argtype = TREE_TYPE (arg);
4779 return fold_if_not_in_template (build1 (code, argtype, arg));
4782 if (complain & tf_error)
4783 error ("%s", errstring);
4784 return error_mark_node;
4787 /* Hook for the c-common bits that build a unary op. */
4789 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4791 return cp_build_unary_op (code, xarg, noconvert, tf_warning_or_error);
4794 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4795 for certain kinds of expressions which are not really lvalues
4796 but which we can accept as lvalues.
4798 If ARG is not a kind of expression we can handle, return
4802 unary_complex_lvalue (enum tree_code code, tree arg)
4804 /* Inside a template, making these kinds of adjustments is
4805 pointless; we are only concerned with the type of the
4807 if (processing_template_decl)
4810 /* Handle (a, b) used as an "lvalue". */
4811 if (TREE_CODE (arg) == COMPOUND_EXPR)
4813 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 1), 0,
4814 tf_warning_or_error);
4815 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4816 TREE_OPERAND (arg, 0), real_result);
4819 /* Handle (a ? b : c) used as an "lvalue". */
4820 if (TREE_CODE (arg) == COND_EXPR
4821 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4822 return rationalize_conditional_expr (code, arg, tf_warning_or_error);
4824 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4825 if (TREE_CODE (arg) == MODIFY_EXPR
4826 || TREE_CODE (arg) == PREINCREMENT_EXPR
4827 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4829 tree lvalue = TREE_OPERAND (arg, 0);
4830 if (TREE_SIDE_EFFECTS (lvalue))
4832 lvalue = stabilize_reference (lvalue);
4833 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4834 lvalue, TREE_OPERAND (arg, 1));
4836 return unary_complex_lvalue
4837 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4840 if (code != ADDR_EXPR)
4843 /* Handle (a = b) used as an "lvalue" for `&'. */
4844 if (TREE_CODE (arg) == MODIFY_EXPR
4845 || TREE_CODE (arg) == INIT_EXPR)
4847 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 0), 0,
4848 tf_warning_or_error);
4849 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4851 TREE_NO_WARNING (arg) = 1;
4855 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4856 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4857 || TREE_CODE (arg) == OFFSET_REF)
4860 /* We permit compiler to make function calls returning
4861 objects of aggregate type look like lvalues. */
4865 if (TREE_CODE (targ) == SAVE_EXPR)
4866 targ = TREE_OPERAND (targ, 0);
4868 if (TREE_CODE (targ) == CALL_EXPR && MAYBE_CLASS_TYPE_P (TREE_TYPE (targ)))
4870 if (TREE_CODE (arg) == SAVE_EXPR)
4873 targ = build_cplus_new (TREE_TYPE (arg), arg);
4874 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4877 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4878 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4879 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4882 /* Don't let anything else be handled specially. */
4886 /* Mark EXP saying that we need to be able to take the
4887 address of it; it should not be allocated in a register.
4888 Value is true if successful.
4890 C++: we do not allow `current_class_ptr' to be addressable. */
4893 cxx_mark_addressable (tree exp)
4898 switch (TREE_CODE (x))
4905 x = TREE_OPERAND (x, 0);
4909 if (x == current_class_ptr)
4911 error ("cannot take the address of %<this%>, which is an rvalue expression");
4912 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4918 /* Caller should not be trying to mark initialized
4919 constant fields addressable. */
4920 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4921 || DECL_IN_AGGR_P (x) == 0
4923 || DECL_EXTERNAL (x));
4928 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4929 && !DECL_ARTIFICIAL (x))
4931 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4934 ("address of explicit register variable %qD requested", x);
4937 else if (extra_warnings)
4939 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4941 TREE_ADDRESSABLE (x) = 1;
4945 TREE_ADDRESSABLE (x) = 1;
4949 TREE_ADDRESSABLE (x) = 1;
4953 TREE_ADDRESSABLE (x) = 1;
4954 cxx_mark_addressable (TREE_OPERAND (x, 0));
4962 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4965 build_x_conditional_expr (tree ifexp, tree op1, tree op2,
4966 tsubst_flags_t complain)
4968 tree orig_ifexp = ifexp;
4969 tree orig_op1 = op1;
4970 tree orig_op2 = op2;
4973 if (processing_template_decl)
4975 /* The standard says that the expression is type-dependent if
4976 IFEXP is type-dependent, even though the eventual type of the
4977 expression doesn't dependent on IFEXP. */
4978 if (type_dependent_expression_p (ifexp)
4979 /* As a GNU extension, the middle operand may be omitted. */
4980 || (op1 && type_dependent_expression_p (op1))
4981 || type_dependent_expression_p (op2))
4982 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4983 ifexp = build_non_dependent_expr (ifexp);
4985 op1 = build_non_dependent_expr (op1);
4986 op2 = build_non_dependent_expr (op2);
4989 expr = build_conditional_expr (ifexp, op1, op2, complain);
4990 if (processing_template_decl && expr != error_mark_node)
4991 return build_min_non_dep (COND_EXPR, expr,
4992 orig_ifexp, orig_op1, orig_op2);
4996 /* Given a list of expressions, return a compound expression
4997 that performs them all and returns the value of the last of them. */
4999 tree build_x_compound_expr_from_list (tree list, const char *msg)
5001 tree expr = TREE_VALUE (list);
5003 if (TREE_CHAIN (list))
5006 permerror ("%s expression list treated as compound expression", msg);
5008 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
5009 expr = build_x_compound_expr (expr, TREE_VALUE (list),
5010 tf_warning_or_error);
5016 /* Handle overloading of the ',' operator when needed. */
5019 build_x_compound_expr (tree op1, tree op2, tsubst_flags_t complain)
5022 tree orig_op1 = op1;
5023 tree orig_op2 = op2;
5025 if (processing_template_decl)
5027 if (type_dependent_expression_p (op1)
5028 || type_dependent_expression_p (op2))
5029 return build_min_nt (COMPOUND_EXPR, op1, op2);
5030 op1 = build_non_dependent_expr (op1);
5031 op2 = build_non_dependent_expr (op2);
5034 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
5035 /*overloaded_p=*/NULL, complain);
5037 result = cp_build_compound_expr (op1, op2, complain);
5039 if (processing_template_decl && result != error_mark_node)
5040 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
5045 /* Like cp_build_compound_expr, but for the c-common bits. */
5048 build_compound_expr (tree lhs, tree rhs)
5050 return cp_build_compound_expr (lhs, rhs, tf_warning_or_error);
5053 /* Build a compound expression. */
5056 cp_build_compound_expr (tree lhs, tree rhs, tsubst_flags_t complain)
5058 lhs = convert_to_void (lhs, "left-hand operand of comma", complain);
5060 if (lhs == error_mark_node || rhs == error_mark_node)
5061 return error_mark_node;
5063 if (TREE_CODE (rhs) == TARGET_EXPR)
5065 /* If the rhs is a TARGET_EXPR, then build the compound
5066 expression inside the target_expr's initializer. This
5067 helps the compiler to eliminate unnecessary temporaries. */
5068 tree init = TREE_OPERAND (rhs, 1);
5070 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
5071 TREE_OPERAND (rhs, 1) = init;
5076 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
5079 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
5080 casts away constness. CAST gives the type of cast. */
5083 check_for_casting_away_constness (tree src_type, tree dest_type,
5084 enum tree_code cast)
5086 /* C-style casts are allowed to cast away constness. With
5087 WARN_CAST_QUAL, we still want to issue a warning. */
5088 if (cast == CAST_EXPR && !warn_cast_qual)
5091 if (casts_away_constness (src_type, dest_type))
5095 warning (OPT_Wcast_qual,
5096 "cast from type %qT to type %qT casts away constness",
5097 src_type, dest_type);
5100 case STATIC_CAST_EXPR:
5101 error ("static_cast from type %qT to type %qT casts away constness",
5102 src_type, dest_type);
5105 case REINTERPRET_CAST_EXPR:
5106 error ("reinterpret_cast from type %qT to type %qT casts away constness",
5107 src_type, dest_type);
5114 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
5115 (another pointer-to-member type in the same hierarchy) and return
5116 the converted expression. If ALLOW_INVERSE_P is permitted, a
5117 pointer-to-derived may be converted to pointer-to-base; otherwise,
5118 only the other direction is permitted. If C_CAST_P is true, this
5119 conversion is taking place as part of a C-style cast. */
5122 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
5125 if (TYPE_PTRMEM_P (type))
5129 if (TREE_CODE (expr) == PTRMEM_CST)
5130 expr = cplus_expand_constant (expr);
5131 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
5132 TYPE_PTRMEM_CLASS_TYPE (type),
5135 if (!integer_zerop (delta))
5137 tree cond, op1, op2;
5139 cond = cp_build_binary_op (EQ_EXPR,
5141 build_int_cst (TREE_TYPE (expr), -1),
5142 tf_warning_or_error);
5143 op1 = build_nop (ptrdiff_type_node, expr);
5144 op2 = cp_build_binary_op (PLUS_EXPR, op1, delta,
5145 tf_warning_or_error);
5147 expr = fold_build3 (COND_EXPR, ptrdiff_type_node, cond, op1, op2);
5151 return build_nop (type, expr);
5154 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
5155 allow_inverse_p, c_cast_p);
5158 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
5159 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
5160 Otherwise, return EXPR unchanged. */
5163 ignore_overflows (tree expr, tree orig)
5165 if (TREE_CODE (expr) == INTEGER_CST
5166 && CONSTANT_CLASS_P (orig)
5167 && TREE_CODE (orig) != STRING_CST
5168 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
5170 if (!TREE_OVERFLOW (orig))
5171 /* Ensure constant sharing. */
5172 expr = build_int_cst_wide (TREE_TYPE (expr),
5173 TREE_INT_CST_LOW (expr),
5174 TREE_INT_CST_HIGH (expr));
5177 /* Avoid clobbering a shared constant. */
5178 expr = copy_node (expr);
5179 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
5185 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
5186 this static_cast is being attempted as one of the possible casts
5187 allowed by a C-style cast. (In that case, accessibility of base
5188 classes is not considered, and it is OK to cast away
5189 constness.) Return the result of the cast. *VALID_P is set to
5190 indicate whether or not the cast was valid. */
5193 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
5194 bool *valid_p, tsubst_flags_t complain)
5200 /* Assume the cast is valid. */
5203 intype = TREE_TYPE (expr);
5205 /* Save casted types in the function's used types hash table. */
5206 used_types_insert (type);
5208 /* [expr.static.cast]
5210 An lvalue of type "cv1 B", where B is a class type, can be cast
5211 to type "reference to cv2 D", where D is a class derived (clause
5212 _class.derived_) from B, if a valid standard conversion from
5213 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
5214 same cv-qualification as, or greater cv-qualification than, cv1,
5215 and B is not a virtual base class of D. */
5216 /* We check this case before checking the validity of "TYPE t =
5217 EXPR;" below because for this case:
5220 struct D : public B { D(const B&); };
5222 void f() { static_cast<const D&>(b); }
5224 we want to avoid constructing a new D. The standard is not
5225 completely clear about this issue, but our interpretation is
5226 consistent with other compilers. */
5227 if (TREE_CODE (type) == REFERENCE_TYPE
5228 && CLASS_TYPE_P (TREE_TYPE (type))
5229 && CLASS_TYPE_P (intype)
5230 && real_lvalue_p (expr)
5231 && DERIVED_FROM_P (intype, TREE_TYPE (type))
5232 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
5233 build_pointer_type (TYPE_MAIN_VARIANT
5234 (TREE_TYPE (type))))
5236 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5240 /* There is a standard conversion from "D*" to "B*" even if "B"
5241 is ambiguous or inaccessible. If this is really a
5242 static_cast, then we check both for inaccessibility and
5243 ambiguity. However, if this is a static_cast being performed
5244 because the user wrote a C-style cast, then accessibility is
5246 base = lookup_base (TREE_TYPE (type), intype,
5247 c_cast_p ? ba_unique : ba_check,
5250 /* Convert from "B*" to "D*". This function will check that "B"
5251 is not a virtual base of "D". */
5252 expr = build_base_path (MINUS_EXPR, build_address (expr),
5253 base, /*nonnull=*/false);
5254 /* Convert the pointer to a reference -- but then remember that
5255 there are no expressions with reference type in C++. */
5256 return convert_from_reference (build_nop (type, expr));
5261 /* [expr.static.cast]
5263 An expression e can be explicitly converted to a type T using a
5264 static_cast of the form static_cast<T>(e) if the declaration T
5265 t(e);" is well-formed, for some invented temporary variable
5267 result = perform_direct_initialization_if_possible (type, expr,
5268 c_cast_p, complain);
5271 result = convert_from_reference (result);
5273 /* Ignore any integer overflow caused by the cast. */
5274 result = ignore_overflows (result, orig);
5276 /* [expr.static.cast]
5278 If T is a reference type, the result is an lvalue; otherwise,
5279 the result is an rvalue. */
5280 if (TREE_CODE (type) != REFERENCE_TYPE)
5281 result = rvalue (result);
5285 /* [expr.static.cast]
5287 Any expression can be explicitly converted to type cv void. */
5288 if (TREE_CODE (type) == VOID_TYPE)
5289 return convert_to_void (expr, /*implicit=*/NULL, complain);
5291 /* [expr.static.cast]
5293 The inverse of any standard conversion sequence (clause _conv_),
5294 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5295 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5296 (_conv.bool_) conversions, can be performed explicitly using
5297 static_cast subject to the restriction that the explicit
5298 conversion does not cast away constness (_expr.const.cast_), and
5299 the following additional rules for specific cases: */
5300 /* For reference, the conversions not excluded are: integral
5301 promotions, floating point promotion, integral conversions,
5302 floating point conversions, floating-integral conversions,
5303 pointer conversions, and pointer to member conversions. */
5306 A value of integral _or enumeration_ type can be explicitly
5307 converted to an enumeration type. */
5308 /* The effect of all that is that any conversion between any two
5309 types which are integral, floating, or enumeration types can be
5311 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5312 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5314 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5316 /* Ignore any integer overflow caused by the cast. */
5317 expr = ignore_overflows (expr, orig);
5321 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5322 && CLASS_TYPE_P (TREE_TYPE (type))
5323 && CLASS_TYPE_P (TREE_TYPE (intype))
5324 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5325 (TREE_TYPE (intype))),
5326 build_pointer_type (TYPE_MAIN_VARIANT
5327 (TREE_TYPE (type)))))
5332 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5333 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5334 c_cast_p ? ba_unique : ba_check,
5336 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5339 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5340 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5347 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5348 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5350 if (TYPE_PTRMEM_P (type))
5352 t1 = (build_ptrmem_type
5354 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5355 t2 = (build_ptrmem_type
5357 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5364 if (can_convert (t1, t2) || can_convert (t2, t1))
5367 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5368 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5373 /* [expr.static.cast]
5375 An rvalue of type "pointer to cv void" can be explicitly
5376 converted to a pointer to object type. A value of type pointer
5377 to object converted to "pointer to cv void" and back to the
5378 original pointer type will have its original value. */
5379 if (TREE_CODE (intype) == POINTER_TYPE
5380 && VOID_TYPE_P (TREE_TYPE (intype))
5381 && TYPE_PTROB_P (type))
5384 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5385 return build_nop (type, expr);
5389 return error_mark_node;
5392 /* Return an expression representing static_cast<TYPE>(EXPR). */
5395 build_static_cast (tree type, tree expr, tsubst_flags_t complain)
5400 if (type == error_mark_node || expr == error_mark_node)
5401 return error_mark_node;
5403 if (processing_template_decl)
5405 expr = build_min (STATIC_CAST_EXPR, type, expr);
5406 /* We don't know if it will or will not have side effects. */
5407 TREE_SIDE_EFFECTS (expr) = 1;
5408 return convert_from_reference (expr);
5411 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5412 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5413 if (TREE_CODE (type) != REFERENCE_TYPE
5414 && TREE_CODE (expr) == NOP_EXPR
5415 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5416 expr = TREE_OPERAND (expr, 0);
5418 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p,
5423 if (complain & tf_error)
5424 error ("invalid static_cast from type %qT to type %qT",
5425 TREE_TYPE (expr), type);
5426 return error_mark_node;
5429 /* EXPR is an expression with member function or pointer-to-member
5430 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5431 not permitted by ISO C++, but we accept it in some modes. If we
5432 are not in one of those modes, issue a diagnostic. Return the
5433 converted expression. */
5436 convert_member_func_to_ptr (tree type, tree expr)
5441 intype = TREE_TYPE (expr);
5442 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5443 || TREE_CODE (intype) == METHOD_TYPE);
5445 if (pedantic || warn_pmf2ptr)
5446 pedwarn ("converting from %qT to %qT", intype, type);
5448 if (TREE_CODE (intype) == METHOD_TYPE)
5449 expr = build_addr_func (expr);
5450 else if (TREE_CODE (expr) == PTRMEM_CST)
5451 expr = build_address (PTRMEM_CST_MEMBER (expr));
5454 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5455 decl = build_address (decl);
5456 expr = get_member_function_from_ptrfunc (&decl, expr);
5459 return build_nop (type, expr);
5462 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5463 If C_CAST_P is true, this reinterpret cast is being done as part of
5464 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5465 indicate whether or not reinterpret_cast was valid. */
5468 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5469 bool *valid_p, tsubst_flags_t complain)
5473 /* Assume the cast is invalid. */
5477 if (type == error_mark_node || error_operand_p (expr))
5478 return error_mark_node;
5480 intype = TREE_TYPE (expr);
5482 /* Save casted types in the function's used types hash table. */
5483 used_types_insert (type);
5485 /* [expr.reinterpret.cast]
5486 An lvalue expression of type T1 can be cast to the type
5487 "reference to T2" if an expression of type "pointer to T1" can be
5488 explicitly converted to the type "pointer to T2" using a
5489 reinterpret_cast. */
5490 if (TREE_CODE (type) == REFERENCE_TYPE)
5492 if (! real_lvalue_p (expr))
5494 if (complain & tf_error)
5495 error ("invalid cast of an rvalue expression of type "
5498 return error_mark_node;
5501 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5502 "B" are related class types; the reinterpret_cast does not
5503 adjust the pointer. */
5504 if (TYPE_PTR_P (intype)
5505 && (complain & tf_warning)
5506 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5507 COMPARE_BASE | COMPARE_DERIVED)))
5508 warning (0, "casting %qT to %qT does not dereference pointer",
5511 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, complain);
5512 if (expr != error_mark_node)
5513 expr = build_reinterpret_cast_1
5514 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5516 if (expr != error_mark_node)
5517 expr = cp_build_indirect_ref (expr, 0, complain);
5521 /* As a G++ extension, we consider conversions from member
5522 functions, and pointers to member functions to
5523 pointer-to-function and pointer-to-void types. If
5524 -Wno-pmf-conversions has not been specified,
5525 convert_member_func_to_ptr will issue an error message. */
5526 if ((TYPE_PTRMEMFUNC_P (intype)
5527 || TREE_CODE (intype) == METHOD_TYPE)
5528 && TYPE_PTR_P (type)
5529 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5530 || VOID_TYPE_P (TREE_TYPE (type))))
5531 return convert_member_func_to_ptr (type, expr);
5533 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5534 array-to-pointer, and function-to-pointer conversions are
5536 expr = decay_conversion (expr);
5538 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5539 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5540 if (TREE_CODE (expr) == NOP_EXPR
5541 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5542 expr = TREE_OPERAND (expr, 0);
5544 if (error_operand_p (expr))
5545 return error_mark_node;
5547 intype = TREE_TYPE (expr);
5549 /* [expr.reinterpret.cast]
5550 A pointer can be converted to any integral type large enough to
5552 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5554 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5556 if (complain & tf_error)
5557 permerror ("cast from %qT to %qT loses precision",
5560 return error_mark_node;
5563 /* [expr.reinterpret.cast]
5564 A value of integral or enumeration type can be explicitly
5565 converted to a pointer. */
5566 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5569 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5570 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5571 return fold_if_not_in_template (build_nop (type, expr));
5572 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5573 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5578 check_for_casting_away_constness (intype, type, REINTERPRET_CAST_EXPR);
5579 /* Warn about possible alignment problems. */
5580 if (STRICT_ALIGNMENT && warn_cast_align
5581 && (complain & tf_warning)
5582 && !VOID_TYPE_P (type)
5583 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5584 && COMPLETE_TYPE_P (TREE_TYPE (type))
5585 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5586 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5587 warning (OPT_Wcast_align, "cast from %qT to %qT "
5588 "increases required alignment of target type", intype, type);
5590 /* We need to strip nops here, because the front end likes to
5591 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5593 if (warn_strict_aliasing <= 2)
5594 strict_aliasing_warning (intype, type, sexpr);
5596 return fold_if_not_in_template (build_nop (type, expr));
5598 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5599 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5601 if (pedantic && (complain & tf_warning))
5602 /* Only issue a warning, as we have always supported this
5603 where possible, and it is necessary in some cases. DR 195
5604 addresses this issue, but as of 2004/10/26 is still in
5606 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5607 return fold_if_not_in_template (build_nop (type, expr));
5609 else if (TREE_CODE (type) == VECTOR_TYPE)
5610 return fold_if_not_in_template (convert_to_vector (type, expr));
5611 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5612 return fold_if_not_in_template (convert_to_integer (type, expr));
5617 if (complain & tf_error)
5618 error ("invalid cast from type %qT to type %qT", intype, type);
5619 return error_mark_node;
5622 return cp_convert (type, expr);
5626 build_reinterpret_cast (tree type, tree expr, tsubst_flags_t complain)
5628 if (type == error_mark_node || expr == error_mark_node)
5629 return error_mark_node;
5631 if (processing_template_decl)
5633 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5635 if (!TREE_SIDE_EFFECTS (t)
5636 && type_dependent_expression_p (expr))
5637 /* There might turn out to be side effects inside expr. */
5638 TREE_SIDE_EFFECTS (t) = 1;
5639 return convert_from_reference (t);
5642 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5643 /*valid_p=*/NULL, complain);
5646 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5647 return an appropriate expression. Otherwise, return
5648 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5649 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5650 performing a C-style cast, its value upon return will indicate
5651 whether or not the conversion succeeded. */
5654 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5658 tree reference_type;
5660 /* Callers are responsible for handling error_mark_node as a
5661 destination type. */
5662 gcc_assert (dst_type != error_mark_node);
5663 /* In a template, callers should be building syntactic
5664 representations of casts, not using this machinery. */
5665 gcc_assert (!processing_template_decl);
5667 /* Assume the conversion is invalid. */
5671 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5674 error ("invalid use of const_cast with type %qT, "
5675 "which is not a pointer, "
5676 "reference, nor a pointer-to-data-member type", dst_type);
5677 return error_mark_node;
5680 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5683 error ("invalid use of const_cast with type %qT, which is a pointer "
5684 "or reference to a function type", dst_type);
5685 return error_mark_node;
5688 /* Save casted types in the function's used types hash table. */
5689 used_types_insert (dst_type);
5691 src_type = TREE_TYPE (expr);
5692 /* Expressions do not really have reference types. */
5693 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5694 src_type = TREE_TYPE (src_type);
5696 /* [expr.const.cast]
5698 An lvalue of type T1 can be explicitly converted to an lvalue of
5699 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5700 types) if a pointer to T1 can be explicitly converted to the type
5701 pointer to T2 using a const_cast. */
5702 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5704 reference_type = dst_type;
5705 if (! real_lvalue_p (expr))
5708 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5709 src_type, dst_type);
5710 return error_mark_node;
5712 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5713 src_type = build_pointer_type (src_type);
5717 reference_type = NULL_TREE;
5718 /* If the destination type is not a reference type, the
5719 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5720 conversions are performed. */
5721 src_type = type_decays_to (src_type);
5722 if (src_type == error_mark_node)
5723 return error_mark_node;
5726 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5727 && comp_ptr_ttypes_const (dst_type, src_type))
5732 /* This cast is actually a C-style cast. Issue a warning if
5733 the user is making a potentially unsafe cast. */
5734 check_for_casting_away_constness (src_type, dst_type, CAST_EXPR);
5738 expr = cp_build_unary_op (ADDR_EXPR, expr, 0,
5739 complain? tf_warning_or_error : tf_none);
5740 expr = build_nop (reference_type, expr);
5741 return convert_from_reference (expr);
5745 expr = decay_conversion (expr);
5746 /* build_c_cast puts on a NOP_EXPR to make the result not an
5747 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5748 non-lvalue context. */
5749 if (TREE_CODE (expr) == NOP_EXPR
5750 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5751 expr = TREE_OPERAND (expr, 0);
5752 return build_nop (dst_type, expr);
5757 error ("invalid const_cast from type %qT to type %qT",
5758 src_type, dst_type);
5759 return error_mark_node;
5763 build_const_cast (tree type, tree expr, tsubst_flags_t complain)
5765 if (type == error_mark_node || error_operand_p (expr))
5766 return error_mark_node;
5768 if (processing_template_decl)
5770 tree t = build_min (CONST_CAST_EXPR, type, expr);
5772 if (!TREE_SIDE_EFFECTS (t)
5773 && type_dependent_expression_p (expr))
5774 /* There might turn out to be side effects inside expr. */
5775 TREE_SIDE_EFFECTS (t) = 1;
5776 return convert_from_reference (t);
5779 return build_const_cast_1 (type, expr, complain & tf_error,
5783 /* Like cp_build_c_cast, but for the c-common bits. */
5786 build_c_cast (tree type, tree expr)
5788 return cp_build_c_cast (type, expr, tf_warning_or_error);
5791 /* Build an expression representing an explicit C-style cast to type
5792 TYPE of expression EXPR. */
5795 cp_build_c_cast (tree type, tree expr, tsubst_flags_t complain)
5801 if (type == error_mark_node || error_operand_p (expr))
5802 return error_mark_node;
5804 if (processing_template_decl)
5806 tree t = build_min (CAST_EXPR, type,
5807 tree_cons (NULL_TREE, value, NULL_TREE));
5808 /* We don't know if it will or will not have side effects. */
5809 TREE_SIDE_EFFECTS (t) = 1;
5810 return convert_from_reference (t);
5813 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5814 'Class') should always be retained, because this information aids
5815 in method lookup. */
5816 if (objc_is_object_ptr (type)
5817 && objc_is_object_ptr (TREE_TYPE (expr)))
5818 return build_nop (type, expr);
5820 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5821 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5822 if (TREE_CODE (type) != REFERENCE_TYPE
5823 && TREE_CODE (value) == NOP_EXPR
5824 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5825 value = TREE_OPERAND (value, 0);
5827 if (TREE_CODE (type) == ARRAY_TYPE)
5829 /* Allow casting from T1* to T2[] because Cfront allows it.
5830 NIHCL uses it. It is not valid ISO C++ however. */
5831 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5833 if (complain & tf_error)
5834 permerror ("ISO C++ forbids casting to an array type %qT", type);
5836 return error_mark_node;
5837 type = build_pointer_type (TREE_TYPE (type));
5841 if (complain & tf_error)
5842 error ("ISO C++ forbids casting to an array type %qT", type);
5843 return error_mark_node;
5847 if (TREE_CODE (type) == FUNCTION_TYPE
5848 || TREE_CODE (type) == METHOD_TYPE)
5850 if (complain & tf_error)
5851 error ("invalid cast to function type %qT", type);
5852 return error_mark_node;
5855 /* A C-style cast can be a const_cast. */
5856 result = build_const_cast_1 (type, value, /*complain=*/false,
5861 /* Or a static cast. */
5862 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5863 &valid_p, complain);
5864 /* Or a reinterpret_cast. */
5866 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5867 &valid_p, complain);
5868 /* The static_cast or reinterpret_cast may be followed by a
5871 /* A valid cast may result in errors if, for example, a
5872 conversion to am ambiguous base class is required. */
5873 && !error_operand_p (result))
5877 /* Non-class rvalues always have cv-unqualified type. */
5878 if (!CLASS_TYPE_P (type))
5879 type = TYPE_MAIN_VARIANT (type);
5880 result_type = TREE_TYPE (result);
5881 if (!CLASS_TYPE_P (result_type))
5882 result_type = TYPE_MAIN_VARIANT (result_type);
5883 /* If the type of RESULT does not match TYPE, perform a
5884 const_cast to make it match. If the static_cast or
5885 reinterpret_cast succeeded, we will differ by at most
5886 cv-qualification, so the follow-on const_cast is guaranteed
5888 if (!same_type_p (non_reference (type), non_reference (result_type)))
5890 result = build_const_cast_1 (type, result, false, &valid_p);
5891 gcc_assert (valid_p);
5896 return error_mark_node;
5899 /* For use from the C common bits. */
5901 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5903 return cp_build_modify_expr (lhs, modifycode, rhs, tf_warning_or_error);
5906 /* Build an assignment expression of lvalue LHS from value RHS.
5907 MODIFYCODE is the code for a binary operator that we use
5908 to combine the old value of LHS with RHS to get the new value.
5909 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5911 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5914 cp_build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
5915 tsubst_flags_t complain)
5919 tree lhstype = TREE_TYPE (lhs);
5920 tree olhstype = lhstype;
5921 tree olhs = NULL_TREE;
5922 bool plain_assign = (modifycode == NOP_EXPR);
5924 /* Avoid duplicate error messages from operands that had errors. */
5925 if (error_operand_p (lhs) || error_operand_p (rhs))
5926 return error_mark_node;
5928 /* Handle control structure constructs used as "lvalues". */
5929 switch (TREE_CODE (lhs))
5931 /* Handle --foo = 5; as these are valid constructs in C++. */
5932 case PREDECREMENT_EXPR:
5933 case PREINCREMENT_EXPR:
5934 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5935 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5936 stabilize_reference (TREE_OPERAND (lhs, 0)),
5937 TREE_OPERAND (lhs, 1));
5938 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0),
5939 modifycode, rhs, complain);
5940 if (newrhs == error_mark_node)
5941 return error_mark_node;
5942 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5944 /* Handle (a, b) used as an "lvalue". */
5946 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 1),
5947 modifycode, rhs, complain);
5948 if (newrhs == error_mark_node)
5949 return error_mark_node;
5950 return build2 (COMPOUND_EXPR, lhstype,
5951 TREE_OPERAND (lhs, 0), newrhs);
5954 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5955 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5956 stabilize_reference (TREE_OPERAND (lhs, 0)),
5957 TREE_OPERAND (lhs, 1));
5958 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs,
5960 if (newrhs == error_mark_node)
5961 return error_mark_node;
5962 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5966 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5967 when neither operand has side-effects. */
5968 if (!lvalue_or_else (lhs, lv_assign, complain))
5969 return error_mark_node;
5971 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5972 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5974 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5975 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5977 TREE_OPERAND (lhs, 0),
5978 TREE_OPERAND (lhs, 1)),
5979 TREE_OPERAND (lhs, 0),
5980 TREE_OPERAND (lhs, 1));
5983 /* Handle (a ? b : c) used as an "lvalue". */
5986 /* Produce (a ? (b = rhs) : (c = rhs))
5987 except that the RHS goes through a save-expr
5988 so the code to compute it is only emitted once. */
5990 tree preeval = NULL_TREE;
5992 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5994 if (complain & tf_error)
5995 error ("void value not ignored as it ought to be");
5996 return error_mark_node;
5999 rhs = stabilize_expr (rhs, &preeval);
6001 /* Check this here to avoid odd errors when trying to convert
6002 a throw to the type of the COND_EXPR. */
6003 if (!lvalue_or_else (lhs, lv_assign, complain))
6004 return error_mark_node;
6006 cond = build_conditional_expr
6007 (TREE_OPERAND (lhs, 0),
6008 cp_build_modify_expr (TREE_OPERAND (lhs, 1),
6009 modifycode, rhs, complain),
6010 cp_build_modify_expr (TREE_OPERAND (lhs, 2),
6011 modifycode, rhs, complain),
6014 if (cond == error_mark_node)
6016 /* Make sure the code to compute the rhs comes out
6017 before the split. */
6019 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
6027 if (modifycode == INIT_EXPR)
6029 if (TREE_CODE (rhs) == CONSTRUCTOR)
6031 if (! same_type_p (TREE_TYPE (rhs), lhstype))
6032 /* Call convert to generate an error; see PR 11063. */
6033 rhs = convert (lhstype, rhs);
6034 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
6035 TREE_SIDE_EFFECTS (result) = 1;
6038 else if (! MAYBE_CLASS_TYPE_P (lhstype))
6039 /* Do the default thing. */;
6042 result = build_special_member_call (lhs, complete_ctor_identifier,
6043 build_tree_list (NULL_TREE, rhs),
6044 lhstype, LOOKUP_NORMAL,
6046 if (result == NULL_TREE)
6047 return error_mark_node;
6053 lhs = require_complete_type (lhs);
6054 if (lhs == error_mark_node)
6055 return error_mark_node;
6057 if (modifycode == NOP_EXPR)
6059 /* `operator=' is not an inheritable operator. */
6060 if (! MAYBE_CLASS_TYPE_P (lhstype))
6061 /* Do the default thing. */;
6064 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
6065 lhs, rhs, make_node (NOP_EXPR),
6066 /*overloaded_p=*/NULL,
6068 if (result == NULL_TREE)
6069 return error_mark_node;
6076 /* A binary op has been requested. Combine the old LHS
6077 value with the RHS producing the value we should actually
6078 store into the LHS. */
6079 gcc_assert (!((TREE_CODE (lhstype) == REFERENCE_TYPE
6080 && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype)))
6081 || MAYBE_CLASS_TYPE_P (lhstype)));
6083 lhs = stabilize_reference (lhs);
6084 newrhs = cp_build_binary_op (modifycode, lhs, rhs,
6086 if (newrhs == error_mark_node)
6088 if (complain & tf_error)
6089 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
6090 TREE_TYPE (lhs), TREE_TYPE (rhs));
6091 return error_mark_node;
6094 /* Now it looks like a plain assignment. */
6095 modifycode = NOP_EXPR;
6097 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
6098 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
6101 /* The left-hand side must be an lvalue. */
6102 if (!lvalue_or_else (lhs, lv_assign, complain))
6103 return error_mark_node;
6105 /* Warn about modifying something that is `const'. Don't warn if
6106 this is initialization. */
6107 if (modifycode != INIT_EXPR
6108 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
6109 /* Functions are not modifiable, even though they are
6111 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
6112 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
6113 /* If it's an aggregate and any field is const, then it is
6114 effectively const. */
6115 || (CLASS_TYPE_P (lhstype)
6116 && C_TYPE_FIELDS_READONLY (lhstype))))
6118 if (complain & tf_error)
6119 readonly_error (lhs, "assignment");
6121 return error_mark_node;
6124 /* If storing into a structure or union member, it has probably been
6125 given type `int'. Compute the type that would go with the actual
6126 amount of storage the member occupies. */
6128 if (TREE_CODE (lhs) == COMPONENT_REF
6129 && (TREE_CODE (lhstype) == INTEGER_TYPE
6130 || TREE_CODE (lhstype) == REAL_TYPE
6131 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
6133 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
6135 /* If storing in a field that is in actuality a short or narrower
6136 than one, we must store in the field in its actual type. */
6138 if (lhstype != TREE_TYPE (lhs))
6140 /* Avoid warnings converting integral types back into enums for
6142 if (TREE_CODE (lhstype) == INTEGER_TYPE
6143 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
6145 if (TREE_SIDE_EFFECTS (lhs))
6146 lhs = stabilize_reference (lhs);
6149 lhs = copy_node (lhs);
6150 TREE_TYPE (lhs) = lhstype;
6154 /* Convert new value to destination type. */
6156 if (TREE_CODE (lhstype) == ARRAY_TYPE)
6160 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
6161 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
6163 if (complain & tf_error)
6164 error ("incompatible types in assignment of %qT to %qT",
6165 TREE_TYPE (rhs), lhstype);
6166 return error_mark_node;
6169 /* Allow array assignment in compiler-generated code. */
6170 if (! DECL_ARTIFICIAL (current_function_decl))
6172 /* This routine is used for both initialization and assignment.
6173 Make sure the diagnostic message differentiates the context. */
6174 if (complain & tf_error)
6176 if (modifycode == INIT_EXPR)
6177 error ("array used as initializer");
6179 error ("invalid array assignment");
6181 return error_mark_node;
6184 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
6185 ? 1 + (modifycode != INIT_EXPR): 0;
6186 return build_vec_init (lhs, NULL_TREE, newrhs,
6187 /*explicit_default_init_p=*/false,
6188 from_array, complain);
6191 if (modifycode == INIT_EXPR)
6192 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
6193 "initialization", NULL_TREE, 0,
6197 /* Avoid warnings on enum bit fields. */
6198 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
6199 && TREE_CODE (lhstype) == INTEGER_TYPE)
6201 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
6202 NULL_TREE, 0, complain);
6203 newrhs = convert_force (lhstype, newrhs, 0);
6206 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
6207 NULL_TREE, 0, complain);
6208 if (TREE_CODE (newrhs) == CALL_EXPR
6209 && TYPE_NEEDS_CONSTRUCTING (lhstype))
6210 newrhs = build_cplus_new (lhstype, newrhs);
6212 /* Can't initialize directly from a TARGET_EXPR, since that would
6213 cause the lhs to be constructed twice, and possibly result in
6214 accidental self-initialization. So we force the TARGET_EXPR to be
6215 expanded without a target. */
6216 if (TREE_CODE (newrhs) == TARGET_EXPR)
6217 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
6218 TREE_OPERAND (newrhs, 0));
6221 if (newrhs == error_mark_node)
6222 return error_mark_node;
6224 if (c_dialect_objc () && flag_objc_gc)
6226 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
6232 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
6233 lhstype, lhs, newrhs);
6235 TREE_SIDE_EFFECTS (result) = 1;
6237 TREE_NO_WARNING (result) = 1;
6239 /* If we got the LHS in a different type for storing in,
6240 convert the result back to the nominal type of LHS
6241 so that the value we return always has the same type
6242 as the LHS argument. */
6244 if (olhstype == TREE_TYPE (result))
6248 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
6249 TREE_NO_WARNING (result) = 1;
6252 return convert_for_assignment (olhstype, result, "assignment",
6253 NULL_TREE, 0, complain);
6257 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
6258 tsubst_flags_t complain)
6260 if (processing_template_decl)
6261 return build_min_nt (MODOP_EXPR, lhs,
6262 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
6264 if (modifycode != NOP_EXPR)
6266 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
6267 make_node (modifycode),
6268 /*overloaded_p=*/NULL,
6272 TREE_NO_WARNING (rval) = 1;
6276 return cp_build_modify_expr (lhs, modifycode, rhs, complain);
6279 /* Helper function for get_delta_difference which assumes FROM is a base
6280 class of TO. Returns a delta for the conversion of pointer-to-member
6281 of FROM to pointer-to-member of TO. If the conversion is invalid,
6282 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
6283 If C_CAST_P is true, this conversion is taking place as part of a C-style
6287 get_delta_difference_1 (tree from, tree to, bool c_cast_p)
6292 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6293 if (kind == bk_inaccessible || kind == bk_ambig)
6295 error (" in pointer to member function conversion");
6296 return size_zero_node;
6300 if (kind != bk_via_virtual)
6301 return BINFO_OFFSET (binfo);
6303 /* FROM is a virtual base class of TO. Issue an error or warning
6304 depending on whether or not this is a reinterpret cast. */
6306 error ("pointer to member conversion via virtual base %qT",
6307 BINFO_TYPE (binfo_from_vbase (binfo)));
6309 return size_zero_node;
6316 /* Get difference in deltas for different pointer to member function
6317 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6318 the conversion is invalid, the constant is zero. If
6319 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6320 If C_CAST_P is true this conversion is taking place as part of a
6323 Note that the naming of FROM and TO is kind of backwards; the return
6324 value is what we add to a TO in order to get a FROM. They are named
6325 this way because we call this function to find out how to convert from
6326 a pointer to member of FROM to a pointer to member of TO. */
6329 get_delta_difference (tree from, tree to,
6330 bool allow_inverse_p,
6335 if (same_type_ignoring_top_level_qualifiers_p (from, to))
6336 /* Pointer to member of incomplete class is permitted*/
6337 result = size_zero_node;
6339 result = get_delta_difference_1 (from, to, c_cast_p);
6343 if (!allow_inverse_p)
6345 error_not_base_type (from, to);
6346 error (" in pointer to member conversion");
6347 result = size_zero_node;
6351 result = get_delta_difference_1 (to, from, c_cast_p);
6354 result = size_diffop (size_zero_node, result);
6357 error_not_base_type (from, to);
6358 error (" in pointer to member conversion");
6359 result = size_zero_node;
6364 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6368 /* Return a constructor for the pointer-to-member-function TYPE using
6369 the other components as specified. */
6372 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6377 VEC(constructor_elt, gc) *v;
6379 /* Pull the FIELD_DECLs out of the type. */
6380 pfn_field = TYPE_FIELDS (type);
6381 delta_field = TREE_CHAIN (pfn_field);
6383 /* Make sure DELTA has the type we want. */
6384 delta = convert_and_check (delta_type_node, delta);
6386 /* Convert to the correct target type if necessary. */
6387 pfn = fold_convert (TREE_TYPE (pfn_field), pfn);
6389 /* Finish creating the initializer. */
6390 v = VEC_alloc(constructor_elt, gc, 2);
6391 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6392 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6393 u = build_constructor (type, v);
6394 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6395 TREE_STATIC (u) = (TREE_CONSTANT (u)
6396 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6398 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6403 /* Build a constructor for a pointer to member function. It can be
6404 used to initialize global variables, local variable, or used
6405 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6408 If FORCE is nonzero, then force this conversion, even if
6409 we would rather not do it. Usually set when using an explicit
6410 cast. A C-style cast is being processed iff C_CAST_P is true.
6412 Return error_mark_node, if something goes wrong. */
6415 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6421 if (error_operand_p (pfn))
6422 return error_mark_node;
6424 pfn_type = TREE_TYPE (pfn);
6425 to_type = build_ptrmemfunc_type (type);
6427 /* Handle multiple conversions of pointer to member functions. */
6428 if (TYPE_PTRMEMFUNC_P (pfn_type))
6430 tree delta = NULL_TREE;
6431 tree npfn = NULL_TREE;
6435 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6436 error ("invalid conversion to type %qT from type %qT",
6439 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6440 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6444 /* We don't have to do any conversion to convert a
6445 pointer-to-member to its own type. But, we don't want to
6446 just return a PTRMEM_CST if there's an explicit cast; that
6447 cast should make the expression an invalid template argument. */
6448 if (TREE_CODE (pfn) != PTRMEM_CST)
6450 if (same_type_p (to_type, pfn_type))
6452 else if (integer_zerop (n))
6453 return build_reinterpret_cast (to_type, pfn,
6454 tf_warning_or_error);
6457 if (TREE_SIDE_EFFECTS (pfn))
6458 pfn = save_expr (pfn);
6460 /* Obtain the function pointer and the current DELTA. */
6461 if (TREE_CODE (pfn) == PTRMEM_CST)
6462 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6465 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6466 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6469 /* Just adjust the DELTA field. */
6470 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6471 (TREE_TYPE (delta), ptrdiff_type_node));
6472 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6473 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node,
6474 tf_warning_or_error);
6475 delta = cp_build_binary_op (PLUS_EXPR, delta, n, tf_warning_or_error);
6476 return build_ptrmemfunc1 (to_type, delta, npfn);
6479 /* Handle null pointer to member function conversions. */
6480 if (integer_zerop (pfn))
6482 pfn = build_c_cast (type, integer_zero_node);
6483 return build_ptrmemfunc1 (to_type,
6488 if (type_unknown_p (pfn))
6489 return instantiate_type (type, pfn, tf_warning_or_error);
6491 fn = TREE_OPERAND (pfn, 0);
6492 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6493 /* In a template, we will have preserved the
6495 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6496 return make_ptrmem_cst (to_type, fn);
6499 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6502 ??? There is no consistency as to the types returned for the above
6503 values. Some code acts as if it were a sizetype and some as if it were
6504 integer_type_node. */
6507 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6509 tree type = TREE_TYPE (cst);
6510 tree fn = PTRMEM_CST_MEMBER (cst);
6511 tree ptr_class, fn_class;
6513 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6515 /* The class that the function belongs to. */
6516 fn_class = DECL_CONTEXT (fn);
6518 /* The class that we're creating a pointer to member of. */
6519 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6521 /* First, calculate the adjustment to the function's class. */
6522 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6525 if (!DECL_VIRTUAL_P (fn))
6526 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6529 /* If we're dealing with a virtual function, we have to adjust 'this'
6530 again, to point to the base which provides the vtable entry for
6531 fn; the call will do the opposite adjustment. */
6532 tree orig_class = DECL_CONTEXT (fn);
6533 tree binfo = binfo_or_else (orig_class, fn_class);
6534 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6535 *delta, BINFO_OFFSET (binfo));
6536 *delta = fold_if_not_in_template (*delta);
6538 /* We set PFN to the vtable offset at which the function can be
6539 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6540 case delta is shifted left, and then incremented). */
6541 *pfn = DECL_VINDEX (fn);
6542 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6543 TYPE_SIZE_UNIT (vtable_entry_type));
6544 *pfn = fold_if_not_in_template (*pfn);
6546 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6548 case ptrmemfunc_vbit_in_pfn:
6549 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6551 *pfn = fold_if_not_in_template (*pfn);
6554 case ptrmemfunc_vbit_in_delta:
6555 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6556 *delta, integer_one_node);
6557 *delta = fold_if_not_in_template (*delta);
6558 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6559 *delta, integer_one_node);
6560 *delta = fold_if_not_in_template (*delta);
6567 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6568 *pfn = fold_if_not_in_template (*pfn);
6572 /* Return an expression for PFN from the pointer-to-member function
6576 pfn_from_ptrmemfunc (tree t)
6578 if (TREE_CODE (t) == PTRMEM_CST)
6583 expand_ptrmemfunc_cst (t, &delta, &pfn);
6588 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6591 /* Return an expression for DELTA from the pointer-to-member function
6595 delta_from_ptrmemfunc (tree t)
6597 if (TREE_CODE (t) == PTRMEM_CST)
6602 expand_ptrmemfunc_cst (t, &delta, &pfn);
6607 return build_ptrmemfunc_access_expr (t, delta_identifier);
6610 /* Convert value RHS to type TYPE as preparation for an assignment to
6611 an lvalue of type TYPE. ERRTYPE is a string to use in error
6612 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6613 are doing the conversion in order to pass the PARMNUMth argument of
6617 convert_for_assignment (tree type, tree rhs,
6618 const char *errtype, tree fndecl, int parmnum,
6619 tsubst_flags_t complain)
6622 enum tree_code coder;
6624 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6625 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6626 rhs = TREE_OPERAND (rhs, 0);
6628 rhstype = TREE_TYPE (rhs);
6629 coder = TREE_CODE (rhstype);
6631 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6632 && vector_types_convertible_p (type, rhstype, true))
6633 return convert (type, rhs);
6635 if (rhs == error_mark_node || rhstype == error_mark_node)
6636 return error_mark_node;
6637 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6638 return error_mark_node;
6640 /* The RHS of an assignment cannot have void type. */
6641 if (coder == VOID_TYPE)
6643 if (complain & tf_error)
6644 error ("void value not ignored as it ought to be");
6645 return error_mark_node;
6648 /* Simplify the RHS if possible. */
6649 if (TREE_CODE (rhs) == CONST_DECL)
6650 rhs = DECL_INITIAL (rhs);
6652 if (c_dialect_objc ())
6655 tree rname = fndecl;
6657 if (!strcmp (errtype, "assignment"))
6659 else if (!strcmp (errtype, "initialization"))
6663 tree selector = objc_message_selector ();
6667 if (selector && parmno > 1)
6674 if (objc_compare_types (type, rhstype, parmno, rname))
6675 return convert (type, rhs);
6680 The expression is implicitly converted (clause _conv_) to the
6681 cv-unqualified type of the left operand.
6683 We allow bad conversions here because by the time we get to this point
6684 we are committed to doing the conversion. If we end up doing a bad
6685 conversion, convert_like will complain. */
6686 if (!can_convert_arg_bad (type, rhstype, rhs))
6688 /* When -Wno-pmf-conversions is use, we just silently allow
6689 conversions from pointers-to-members to plain pointers. If
6690 the conversion doesn't work, cp_convert will complain. */
6692 && TYPE_PTR_P (type)
6693 && TYPE_PTRMEMFUNC_P (rhstype))
6694 rhs = cp_convert (strip_top_quals (type), rhs);
6697 if (complain & tf_error)
6699 /* If the right-hand side has unknown type, then it is an
6700 overloaded function. Call instantiate_type to get error
6702 if (rhstype == unknown_type_node)
6703 instantiate_type (type, rhs, tf_warning_or_error);
6705 error ("cannot convert %qT to %qT for argument %qP to %qD",
6706 rhstype, type, parmnum, fndecl);
6708 error ("cannot convert %qT to %qT in %s", rhstype, type,
6711 return error_mark_node;
6714 if (warn_missing_format_attribute)
6716 const enum tree_code codel = TREE_CODE (type);
6717 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6719 && check_missing_format_attribute (type, rhstype)
6720 && (complain & tf_warning))
6721 warning (OPT_Wmissing_format_attribute,
6722 "%s might be a candidate for a format attribute",
6726 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6728 if (warn_parentheses
6729 && type == boolean_type_node
6730 && TREE_CODE (rhs) == MODIFY_EXPR
6731 && !TREE_NO_WARNING (rhs)
6732 && TREE_TYPE (rhs) != boolean_type_node
6733 && (complain & tf_warning))
6735 warning (OPT_Wparentheses,
6736 "suggest parentheses around assignment used as truth value");
6737 TREE_NO_WARNING (rhs) = 1;
6740 return perform_implicit_conversion (strip_top_quals (type), rhs, complain);
6743 /* Convert RHS to be of type TYPE.
6744 If EXP is nonzero, it is the target of the initialization.
6745 ERRTYPE is a string to use in error messages.
6747 Two major differences between the behavior of
6748 `convert_for_assignment' and `convert_for_initialization'
6749 are that references are bashed in the former, while
6750 copied in the latter, and aggregates are assigned in
6751 the former (operator=) while initialized in the
6754 If using constructor make sure no conversion operator exists, if one does
6755 exist, an ambiguity exists.
6757 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6760 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6761 const char *errtype, tree fndecl, int parmnum,
6762 tsubst_flags_t complain)
6764 enum tree_code codel = TREE_CODE (type);
6766 enum tree_code coder;
6768 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6769 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6770 if (TREE_CODE (rhs) == NOP_EXPR
6771 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6772 && codel != REFERENCE_TYPE)
6773 rhs = TREE_OPERAND (rhs, 0);
6775 if (type == error_mark_node
6776 || rhs == error_mark_node
6777 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6778 return error_mark_node;
6780 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6781 && TREE_CODE (type) != ARRAY_TYPE
6782 && (TREE_CODE (type) != REFERENCE_TYPE
6783 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6784 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6785 && (TREE_CODE (type) != REFERENCE_TYPE
6786 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6787 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6788 rhs = decay_conversion (rhs);
6790 rhstype = TREE_TYPE (rhs);
6791 coder = TREE_CODE (rhstype);
6793 if (coder == ERROR_MARK)
6794 return error_mark_node;
6796 /* We accept references to incomplete types, so we can
6797 return here before checking if RHS is of complete type. */
6799 if (codel == REFERENCE_TYPE)
6801 /* This should eventually happen in convert_arguments. */
6802 int savew = 0, savee = 0;
6805 savew = warningcount, savee = errorcount;
6806 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6810 if (warningcount > savew)
6811 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6812 else if (errorcount > savee)
6813 error ("in passing argument %P of %q+D", parmnum, fndecl);
6819 exp = require_complete_type (exp);
6820 if (exp == error_mark_node)
6821 return error_mark_node;
6823 rhstype = non_reference (rhstype);
6825 type = complete_type (type);
6827 if (MAYBE_CLASS_TYPE_P (type))
6828 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6830 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum,
6834 /* If RETVAL is the address of, or a reference to, a local variable or
6835 temporary give an appropriate warning. */
6838 maybe_warn_about_returning_address_of_local (tree retval)
6840 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6841 tree whats_returned = retval;
6845 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6846 whats_returned = TREE_OPERAND (whats_returned, 1);
6847 else if (CONVERT_EXPR_P (whats_returned)
6848 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR)
6849 whats_returned = TREE_OPERAND (whats_returned, 0);
6854 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6856 whats_returned = TREE_OPERAND (whats_returned, 0);
6858 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6860 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6861 || TREE_CODE (whats_returned) == TARGET_EXPR)
6863 warning (0, "returning reference to temporary");
6866 if (TREE_CODE (whats_returned) == VAR_DECL
6867 && DECL_NAME (whats_returned)
6868 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6870 warning (0, "reference to non-lvalue returned");
6875 while (TREE_CODE (whats_returned) == COMPONENT_REF
6876 || TREE_CODE (whats_returned) == ARRAY_REF)
6877 whats_returned = TREE_OPERAND (whats_returned, 0);
6879 if (DECL_P (whats_returned)
6880 && DECL_NAME (whats_returned)
6881 && DECL_FUNCTION_SCOPE_P (whats_returned)
6882 && !(TREE_STATIC (whats_returned)
6883 || TREE_PUBLIC (whats_returned)))
6885 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6886 warning (0, "reference to local variable %q+D returned",
6889 warning (0, "address of local variable %q+D returned",
6895 /* Check that returning RETVAL from the current function is valid.
6896 Return an expression explicitly showing all conversions required to
6897 change RETVAL into the function return type, and to assign it to
6898 the DECL_RESULT for the function. Set *NO_WARNING to true if
6899 code reaches end of non-void function warning shouldn't be issued
6900 on this RETURN_EXPR. */
6903 check_return_expr (tree retval, bool *no_warning)
6906 /* The type actually returned by the function, after any
6909 int fn_returns_value_p;
6910 bool named_return_value_okay_p;
6912 *no_warning = false;
6914 /* A `volatile' function is one that isn't supposed to return, ever.
6915 (This is a G++ extension, used to get better code for functions
6916 that call the `volatile' function.) */
6917 if (TREE_THIS_VOLATILE (current_function_decl))
6918 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6920 /* Check for various simple errors. */
6921 if (DECL_DESTRUCTOR_P (current_function_decl))
6924 error ("returning a value from a destructor");
6927 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6929 if (in_function_try_handler)
6930 /* If a return statement appears in a handler of the
6931 function-try-block of a constructor, the program is ill-formed. */
6932 error ("cannot return from a handler of a function-try-block of a constructor");
6934 /* You can't return a value from a constructor. */
6935 error ("returning a value from a constructor");
6939 if (processing_template_decl)
6941 current_function_returns_value = 1;
6942 if (check_for_bare_parameter_packs (retval))
6943 retval = error_mark_node;
6947 /* When no explicit return-value is given in a function with a named
6948 return value, the named return value is used. */
6949 result = DECL_RESULT (current_function_decl);
6950 valtype = TREE_TYPE (result);
6951 gcc_assert (valtype != NULL_TREE);
6952 fn_returns_value_p = !VOID_TYPE_P (valtype);
6953 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6956 /* Check for a return statement with no return value in a function
6957 that's supposed to return a value. */
6958 if (!retval && fn_returns_value_p)
6960 permerror ("return-statement with no value, in function returning %qT",
6962 /* Clear this, so finish_function won't say that we reach the
6963 end of a non-void function (which we don't, we gave a
6965 current_function_returns_null = 0;
6966 /* And signal caller that TREE_NO_WARNING should be set on the
6967 RETURN_EXPR to avoid control reaches end of non-void function
6968 warnings in tree-cfg.c. */
6971 /* Check for a return statement with a value in a function that
6972 isn't supposed to return a value. */
6973 else if (retval && !fn_returns_value_p)
6975 if (VOID_TYPE_P (TREE_TYPE (retval)))
6976 /* You can return a `void' value from a function of `void'
6977 type. In that case, we have to evaluate the expression for
6978 its side-effects. */
6979 finish_expr_stmt (retval);
6981 permerror ("return-statement with a value, in function "
6982 "returning 'void'");
6984 current_function_returns_null = 1;
6986 /* There's really no value to return, after all. */
6990 /* Remember that this function can sometimes return without a
6992 current_function_returns_null = 1;
6994 /* Remember that this function did return a value. */
6995 current_function_returns_value = 1;
6997 /* Check for erroneous operands -- but after giving ourselves a
6998 chance to provide an error about returning a value from a void
7000 if (error_operand_p (retval))
7002 current_function_return_value = error_mark_node;
7003 return error_mark_node;
7006 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
7007 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
7008 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
7009 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
7011 && retval && null_ptr_cst_p (retval))
7012 warning (0, "%<operator new%> must not return NULL unless it is "
7013 "declared %<throw()%> (or -fcheck-new is in effect)");
7015 /* Effective C++ rule 15. See also start_function. */
7017 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
7021 /* The function return type must be a reference to the current
7023 if (TREE_CODE (valtype) == REFERENCE_TYPE
7024 && same_type_ignoring_top_level_qualifiers_p
7025 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
7027 /* Returning '*this' is obviously OK. */
7028 if (retval == current_class_ref)
7030 /* If we are calling a function whose return type is the same of
7031 the current class reference, it is ok. */
7032 else if (TREE_CODE (retval) == INDIRECT_REF
7033 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
7038 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
7041 /* The fabled Named Return Value optimization, as per [class.copy]/15:
7043 [...] For a function with a class return type, if the expression
7044 in the return statement is the name of a local object, and the cv-
7045 unqualified type of the local object is the same as the function
7046 return type, an implementation is permitted to omit creating the tem-
7047 porary object to hold the function return value [...]
7049 So, if this is a value-returning function that always returns the same
7050 local variable, remember it.
7052 It might be nice to be more flexible, and choose the first suitable
7053 variable even if the function sometimes returns something else, but
7054 then we run the risk of clobbering the variable we chose if the other
7055 returned expression uses the chosen variable somehow. And people expect
7056 this restriction, anyway. (jason 2000-11-19)
7058 See finish_function and finalize_nrv for the rest of this optimization. */
7060 named_return_value_okay_p =
7061 (retval != NULL_TREE
7062 /* Must be a local, automatic variable. */
7063 && TREE_CODE (retval) == VAR_DECL
7064 && DECL_CONTEXT (retval) == current_function_decl
7065 && ! TREE_STATIC (retval)
7066 && ! DECL_ANON_UNION_VAR_P (retval)
7067 && (DECL_ALIGN (retval)
7068 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
7069 /* The cv-unqualified type of the returned value must be the
7070 same as the cv-unqualified return type of the
7072 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
7074 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
7075 /* And the returned value must be non-volatile. */
7076 && ! TYPE_VOLATILE (TREE_TYPE (retval)));
7078 if (fn_returns_value_p && flag_elide_constructors)
7080 if (named_return_value_okay_p
7081 && (current_function_return_value == NULL_TREE
7082 || current_function_return_value == retval))
7083 current_function_return_value = retval;
7085 current_function_return_value = error_mark_node;
7088 /* We don't need to do any conversions when there's nothing being
7093 /* Do any required conversions. */
7094 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
7095 /* No conversions are required. */
7099 /* The type the function is declared to return. */
7100 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
7101 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
7103 /* The functype's return type will have been set to void, if it
7104 was an incomplete type. Just treat this as 'return;' */
7105 if (VOID_TYPE_P (functype))
7106 return error_mark_node;
7108 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
7109 treated as an rvalue for the purposes of overload resolution to
7110 favor move constructors over copy constructors. */
7111 if ((cxx_dialect != cxx98)
7112 && named_return_value_okay_p
7113 /* The variable must not have the `volatile' qualifier. */
7114 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
7115 /* The return type must be a class type. */
7116 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
7117 flags = flags | LOOKUP_PREFER_RVALUE;
7119 /* First convert the value to the function's return type, then
7120 to the type of return value's location to handle the
7121 case that functype is smaller than the valtype. */
7122 retval = convert_for_initialization
7123 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0,
7124 tf_warning_or_error);
7125 retval = convert (valtype, retval);
7127 /* If the conversion failed, treat this just like `return;'. */
7128 if (retval == error_mark_node)
7130 /* We can't initialize a register from a AGGR_INIT_EXPR. */
7131 else if (! cfun->returns_struct
7132 && TREE_CODE (retval) == TARGET_EXPR
7133 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
7134 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
7135 TREE_OPERAND (retval, 0));
7137 maybe_warn_about_returning_address_of_local (retval);
7140 /* Actually copy the value returned into the appropriate location. */
7141 if (retval && retval != result)
7142 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
7148 /* Returns nonzero if the pointer-type FROM can be converted to the
7149 pointer-type TO via a qualification conversion. If CONSTP is -1,
7150 then we return nonzero if the pointers are similar, and the
7151 cv-qualification signature of FROM is a proper subset of that of TO.
7153 If CONSTP is positive, then all outer pointers have been
7157 comp_ptr_ttypes_real (tree to, tree from, int constp)
7159 bool to_more_cv_qualified = false;
7160 bool is_opaque_pointer = false;
7162 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7164 if (TREE_CODE (to) != TREE_CODE (from))
7167 if (TREE_CODE (from) == OFFSET_TYPE
7168 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
7169 TYPE_OFFSET_BASETYPE (to)))
7172 /* Const and volatile mean something different for function types,
7173 so the usual checks are not appropriate. */
7174 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
7176 /* In Objective-C++, some types may have been 'volatilized' by
7177 the compiler for EH; when comparing them here, the volatile
7178 qualification must be ignored. */
7179 bool objc_quals_match = objc_type_quals_match (to, from);
7181 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
7184 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
7188 to_more_cv_qualified = true;
7192 constp &= TYPE_READONLY (to);
7195 if (TREE_CODE (to) == VECTOR_TYPE)
7196 is_opaque_pointer = vector_targets_convertible_p (to, from);
7198 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
7199 return ((constp >= 0 || to_more_cv_qualified)
7200 && (is_opaque_pointer
7201 || same_type_ignoring_top_level_qualifiers_p (to, from)));
7205 /* When comparing, say, char ** to char const **, this function takes
7206 the 'char *' and 'char const *'. Do not pass non-pointer/reference
7207 types to this function. */
7210 comp_ptr_ttypes (tree to, tree from)
7212 return comp_ptr_ttypes_real (to, from, 1);
7215 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
7216 type or inheritance-related types, regardless of cv-quals. */
7219 ptr_reasonably_similar (const_tree to, const_tree from)
7221 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7223 /* Any target type is similar enough to void. */
7224 if (TREE_CODE (to) == VOID_TYPE
7225 || TREE_CODE (from) == VOID_TYPE)
7228 if (TREE_CODE (to) != TREE_CODE (from))
7231 if (TREE_CODE (from) == OFFSET_TYPE
7232 && comptypes (TYPE_OFFSET_BASETYPE (to),
7233 TYPE_OFFSET_BASETYPE (from),
7234 COMPARE_BASE | COMPARE_DERIVED))
7237 if (TREE_CODE (to) == VECTOR_TYPE
7238 && vector_types_convertible_p (to, from, false))
7241 if (TREE_CODE (to) == INTEGER_TYPE
7242 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
7245 if (TREE_CODE (to) == FUNCTION_TYPE)
7248 if (TREE_CODE (to) != POINTER_TYPE)
7250 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
7251 COMPARE_BASE | COMPARE_DERIVED);
7255 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
7256 pointer-to-member types) are the same, ignoring cv-qualification at
7260 comp_ptr_ttypes_const (tree to, tree from)
7262 bool is_opaque_pointer = false;
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) == VECTOR_TYPE)
7275 is_opaque_pointer = vector_targets_convertible_p (to, from);
7277 if (TREE_CODE (to) != POINTER_TYPE)
7278 return (is_opaque_pointer
7279 || same_type_ignoring_top_level_qualifiers_p (to, from));
7283 /* Returns the type qualifiers for this type, including the qualifiers on the
7284 elements for an array type. */
7287 cp_type_quals (const_tree type)
7289 /* This CONST_CAST is okay because strip_array_types returns it's
7290 argument unmodified and we assign it to a const_tree. */
7291 type = strip_array_types (CONST_CAST_TREE(type));
7292 if (type == error_mark_node)
7293 return TYPE_UNQUALIFIED;
7294 return TYPE_QUALS (type);
7297 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
7301 cp_type_readonly (const_tree type)
7303 /* This CONST_CAST is okay because strip_array_types returns it's
7304 argument unmodified and we assign it to a const_tree. */
7305 type = strip_array_types (CONST_CAST_TREE(type));
7306 return TYPE_READONLY (type);
7309 /* Returns nonzero if the TYPE contains a mutable member. */
7312 cp_has_mutable_p (const_tree type)
7314 /* This CONST_CAST is okay because strip_array_types returns it's
7315 argument unmodified and we assign it to a const_tree. */
7316 type = strip_array_types (CONST_CAST_TREE(type));
7318 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
7321 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
7322 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
7323 approximation. In particular, consider:
7326 struct S { int i; };
7327 const S s = { f(); }
7329 Here, we will make "s" as TREE_READONLY (because it is declared
7330 "const") -- only to reverse ourselves upon seeing that the
7331 initializer is non-constant. */
7334 cp_apply_type_quals_to_decl (int type_quals, tree decl)
7336 tree type = TREE_TYPE (decl);
7338 if (type == error_mark_node)
7341 if (TREE_CODE (type) == FUNCTION_TYPE
7342 && type_quals != TYPE_UNQUALIFIED)
7344 /* This was an error in C++98 (cv-qualifiers cannot be added to
7345 a function type), but DR 295 makes the code well-formed by
7346 dropping the extra qualifiers. */
7349 tree bad_type = build_qualified_type (type, type_quals);
7350 pedwarn ("ignoring %qV qualifiers added to function type %qT",
7354 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
7358 /* Avoid setting TREE_READONLY incorrectly. */
7359 if (/* If the object has a constructor, the constructor may modify
7361 TYPE_NEEDS_CONSTRUCTING (type)
7362 /* If the type isn't complete, we don't know yet if it will need
7364 || !COMPLETE_TYPE_P (type)
7365 /* If the type has a mutable component, that component might be
7367 || TYPE_HAS_MUTABLE_P (type))
7368 type_quals &= ~TYPE_QUAL_CONST;
7370 c_apply_type_quals_to_decl (type_quals, decl);
7373 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7374 exemplar types such that casting T1 to T2 is casting away constness
7375 if and only if there is no implicit conversion from T1 to T2. */
7378 casts_away_constness_r (tree *t1, tree *t2)
7383 /* [expr.const.cast]
7385 For multi-level pointer to members and multi-level mixed pointers
7386 and pointers to members (conv.qual), the "member" aspect of a
7387 pointer to member level is ignored when determining if a const
7388 cv-qualifier has been cast away. */
7389 /* [expr.const.cast]
7391 For two pointer types:
7393 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7394 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7397 casting from X1 to X2 casts away constness if, for a non-pointer
7398 type T there does not exist an implicit conversion (clause
7401 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7405 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7406 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7407 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7409 *t1 = cp_build_qualified_type (void_type_node,
7410 cp_type_quals (*t1));
7411 *t2 = cp_build_qualified_type (void_type_node,
7412 cp_type_quals (*t2));
7416 quals1 = cp_type_quals (*t1);
7417 quals2 = cp_type_quals (*t2);
7419 if (TYPE_PTRMEM_P (*t1))
7420 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7422 *t1 = TREE_TYPE (*t1);
7423 if (TYPE_PTRMEM_P (*t2))
7424 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7426 *t2 = TREE_TYPE (*t2);
7428 casts_away_constness_r (t1, t2);
7429 *t1 = build_pointer_type (*t1);
7430 *t2 = build_pointer_type (*t2);
7431 *t1 = cp_build_qualified_type (*t1, quals1);
7432 *t2 = cp_build_qualified_type (*t2, quals2);
7435 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7439 casts_away_constness (tree t1, tree t2)
7441 if (TREE_CODE (t2) == REFERENCE_TYPE)
7443 /* [expr.const.cast]
7445 Casting from an lvalue of type T1 to an lvalue of type T2
7446 using a reference cast casts away constness if a cast from an
7447 rvalue of type "pointer to T1" to the type "pointer to T2"
7448 casts away constness. */
7449 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7450 return casts_away_constness (build_pointer_type (t1),
7451 build_pointer_type (TREE_TYPE (t2)));
7454 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7455 /* [expr.const.cast]
7457 Casting from an rvalue of type "pointer to data member of X
7458 of type T1" to the type "pointer to data member of Y of type
7459 T2" casts away constness if a cast from an rvalue of type
7460 "pointer to T1" to the type "pointer to T2" casts away
7462 return casts_away_constness
7463 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7464 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7466 /* Casting away constness is only something that makes sense for
7467 pointer or reference types. */
7468 if (TREE_CODE (t1) != POINTER_TYPE
7469 || TREE_CODE (t2) != POINTER_TYPE)
7472 /* Top-level qualifiers don't matter. */
7473 t1 = TYPE_MAIN_VARIANT (t1);
7474 t2 = TYPE_MAIN_VARIANT (t2);
7475 casts_away_constness_r (&t1, &t2);
7476 if (!can_convert (t2, t1))
7482 /* If T is a REFERENCE_TYPE return the type to which T refers.
7483 Otherwise, return T itself. */
7486 non_reference (tree t)
7488 if (TREE_CODE (t) == REFERENCE_TYPE)
7494 /* Return nonzero if REF is an lvalue valid for this language;
7495 otherwise, print an error message and return zero. USE says
7496 how the lvalue is being used and so selects the error message. */
7499 lvalue_or_else (const_tree ref, enum lvalue_use use, tsubst_flags_t complain)
7501 int win = lvalue_p (ref);
7503 if (!win && (complain & tf_error))