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 pedwarn ("%s between distinct pointer types %qT and %qT "
441 result_type = void_type_node;
443 result_type = cp_build_qualified_type (result_type,
444 (cp_type_quals (pointee1)
445 | cp_type_quals (pointee2)));
446 /* If the original types were pointers to members, so is the
448 if (TYPE_PTR_TO_MEMBER_P (t1))
450 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
451 TYPE_PTRMEM_CLASS_TYPE (t2))
452 && (complain & tf_error))
453 pedwarn ("%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 pedwarn ("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 pedwarn ("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_C_BIT_FIELD (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);
1520 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0)))
1521 == TYPE_MAIN_VARIANT (TREE_TYPE (exp)))
1522 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1530 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1531 bitfield with a lowered type, the type of EXP is returned, rather
1535 unlowered_expr_type (const_tree exp)
1539 type = is_bitfield_expr_with_lowered_type (exp);
1541 type = TREE_TYPE (exp);
1546 /* Perform the conversions in [expr] that apply when an lvalue appears
1547 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1548 function-to-pointer conversions. In addition, manifest constants
1549 are replaced by their values, and bitfield references are converted
1550 to their declared types.
1552 Although the returned value is being used as an rvalue, this
1553 function does not wrap the returned expression in a
1554 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1555 that the return value is no longer an lvalue. */
1558 decay_conversion (tree exp)
1561 enum tree_code code;
1563 type = TREE_TYPE (exp);
1564 if (type == error_mark_node)
1565 return error_mark_node;
1567 if (type_unknown_p (exp))
1569 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1570 return error_mark_node;
1573 exp = decl_constant_value (exp);
1574 if (error_operand_p (exp))
1575 return error_mark_node;
1577 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1578 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1579 code = TREE_CODE (type);
1580 if (code == VOID_TYPE)
1582 error ("void value not ignored as it ought to be");
1583 return error_mark_node;
1585 if (invalid_nonstatic_memfn_p (exp, tf_warning_or_error))
1586 return error_mark_node;
1587 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1588 return cp_build_unary_op (ADDR_EXPR, exp, 0, tf_warning_or_error);
1589 if (code == ARRAY_TYPE)
1594 if (TREE_CODE (exp) == INDIRECT_REF)
1595 return build_nop (build_pointer_type (TREE_TYPE (type)),
1596 TREE_OPERAND (exp, 0));
1598 if (TREE_CODE (exp) == COMPOUND_EXPR)
1600 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1601 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1602 TREE_OPERAND (exp, 0), op1);
1606 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1608 error ("invalid use of non-lvalue array");
1609 return error_mark_node;
1612 ptrtype = build_pointer_type (TREE_TYPE (type));
1614 if (TREE_CODE (exp) == VAR_DECL)
1616 if (!cxx_mark_addressable (exp))
1617 return error_mark_node;
1618 adr = build_nop (ptrtype, build_address (exp));
1621 /* This way is better for a COMPONENT_REF since it can
1622 simplify the offset for a component. */
1623 adr = cp_build_unary_op (ADDR_EXPR, exp, 1, tf_warning_or_error);
1624 return cp_convert (ptrtype, adr);
1627 /* If a bitfield is used in a context where integral promotion
1628 applies, then the caller is expected to have used
1629 default_conversion. That function promotes bitfields correctly
1630 before calling this function. At this point, if we have a
1631 bitfield referenced, we may assume that is not subject to
1632 promotion, and that, therefore, the type of the resulting rvalue
1633 is the declared type of the bitfield. */
1634 exp = convert_bitfield_to_declared_type (exp);
1636 /* We do not call rvalue() here because we do not want to wrap EXP
1637 in a NON_LVALUE_EXPR. */
1641 Non-class rvalues always have cv-unqualified types. */
1642 type = TREE_TYPE (exp);
1643 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1644 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1649 /* Perform prepatory conversions, as part of the "usual arithmetic
1650 conversions". In particular, as per [expr]:
1652 Whenever an lvalue expression appears as an operand of an
1653 operator that expects the rvalue for that operand, the
1654 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1655 standard conversions are applied to convert the expression to an
1658 In addition, we perform integral promotions here, as those are
1659 applied to both operands to a binary operator before determining
1660 what additional conversions should apply. */
1663 default_conversion (tree exp)
1665 /* Perform the integral promotions first so that bitfield
1666 expressions (which may promote to "int", even if the bitfield is
1667 declared "unsigned") are promoted correctly. */
1668 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1669 exp = perform_integral_promotions (exp);
1670 /* Perform the other conversions. */
1671 exp = decay_conversion (exp);
1676 /* EXPR is an expression with an integral or enumeration type.
1677 Perform the integral promotions in [conv.prom], and return the
1681 perform_integral_promotions (tree expr)
1688 If the bitfield has an enumerated type, it is treated as any
1689 other value of that type for promotion purposes. */
1690 type = is_bitfield_expr_with_lowered_type (expr);
1691 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1692 type = TREE_TYPE (expr);
1693 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1694 promoted_type = type_promotes_to (type);
1695 if (type != promoted_type)
1696 expr = cp_convert (promoted_type, expr);
1700 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1704 inline_conversion (tree exp)
1706 if (TREE_CODE (exp) == FUNCTION_DECL)
1707 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1712 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1713 decay_conversion to one. */
1716 string_conv_p (const_tree totype, const_tree exp, int warn)
1720 if (TREE_CODE (totype) != POINTER_TYPE)
1723 t = TREE_TYPE (totype);
1724 if (!same_type_p (t, char_type_node)
1725 && !same_type_p (t, wchar_type_node))
1728 if (TREE_CODE (exp) == STRING_CST)
1730 /* Make sure that we don't try to convert between char and wchar_t. */
1731 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1736 /* Is this a string constant which has decayed to 'const char *'? */
1737 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1738 if (!same_type_p (TREE_TYPE (exp), t))
1741 if (TREE_CODE (exp) != ADDR_EXPR
1742 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1746 /* This warning is not very useful, as it complains about printf. */
1748 warning (OPT_Wwrite_strings,
1749 "deprecated conversion from string constant to %qT",
1755 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1756 can, for example, use as an lvalue. This code used to be in
1757 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1758 expressions, where we're dealing with aggregates. But now it's again only
1759 called from unary_complex_lvalue. The case (in particular) that led to
1760 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1764 rationalize_conditional_expr (enum tree_code code, tree t,
1765 tsubst_flags_t complain)
1767 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1768 the first operand is always the one to be used if both operands
1769 are equal, so we know what conditional expression this used to be. */
1770 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1772 tree op0 = TREE_OPERAND (t, 0);
1773 tree op1 = TREE_OPERAND (t, 1);
1775 /* The following code is incorrect if either operand side-effects. */
1776 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1777 && !TREE_SIDE_EFFECTS (op1));
1779 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1780 ? LE_EXPR : GE_EXPR),
1781 op0, TREE_CODE (op0),
1782 op1, TREE_CODE (op1),
1783 /*overloaded_p=*/NULL,
1785 cp_build_unary_op (code, op0, 0, complain),
1786 cp_build_unary_op (code, op1, 0, complain),
1791 build_conditional_expr (TREE_OPERAND (t, 0),
1792 cp_build_unary_op (code, TREE_OPERAND (t, 1), 0,
1794 cp_build_unary_op (code, TREE_OPERAND (t, 2), 0,
1799 /* Given the TYPE of an anonymous union field inside T, return the
1800 FIELD_DECL for the field. If not found return NULL_TREE. Because
1801 anonymous unions can nest, we must also search all anonymous unions
1802 that are directly reachable. */
1805 lookup_anon_field (tree t, tree type)
1809 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1811 if (TREE_STATIC (field))
1813 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1816 /* If we find it directly, return the field. */
1817 if (DECL_NAME (field) == NULL_TREE
1818 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1823 /* Otherwise, it could be nested, search harder. */
1824 if (DECL_NAME (field) == NULL_TREE
1825 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1827 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1835 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1836 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1837 non-NULL, it indicates the path to the base used to name MEMBER.
1838 If PRESERVE_REFERENCE is true, the expression returned will have
1839 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1840 returned will have the type referred to by the reference.
1842 This function does not perform access control; that is either done
1843 earlier by the parser when the name of MEMBER is resolved to MEMBER
1844 itself, or later when overload resolution selects one of the
1845 functions indicated by MEMBER. */
1848 build_class_member_access_expr (tree object, tree member,
1849 tree access_path, bool preserve_reference,
1850 tsubst_flags_t complain)
1854 tree result = NULL_TREE;
1856 if (error_operand_p (object) || error_operand_p (member))
1857 return error_mark_node;
1859 gcc_assert (DECL_P (member) || BASELINK_P (member));
1863 The type of the first expression shall be "class object" (of a
1865 object_type = TREE_TYPE (object);
1866 if (!currently_open_class (object_type)
1867 && !complete_type_or_else (object_type, object))
1868 return error_mark_node;
1869 if (!CLASS_TYPE_P (object_type))
1871 if (complain & tf_error)
1872 error ("request for member %qD in %qE, which is of non-class type %qT",
1873 member, object, object_type);
1874 return error_mark_node;
1877 /* The standard does not seem to actually say that MEMBER must be a
1878 member of OBJECT_TYPE. However, that is clearly what is
1880 if (DECL_P (member))
1882 member_scope = DECL_CLASS_CONTEXT (member);
1884 if (TREE_DEPRECATED (member))
1885 warn_deprecated_use (member);
1888 member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member));
1889 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1890 presently be the anonymous union. Go outwards until we find a
1891 type related to OBJECT_TYPE. */
1892 while (ANON_AGGR_TYPE_P (member_scope)
1893 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1895 member_scope = TYPE_CONTEXT (member_scope);
1896 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1898 if (complain & tf_error)
1900 if (TREE_CODE (member) == FIELD_DECL)
1901 error ("invalid use of nonstatic data member %qE", member);
1903 error ("%qD is not a member of %qT", member, object_type);
1905 return error_mark_node;
1908 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1909 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1910 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1912 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1914 object = cp_build_indirect_ref (temp, NULL, complain);
1917 /* In [expr.ref], there is an explicit list of the valid choices for
1918 MEMBER. We check for each of those cases here. */
1919 if (TREE_CODE (member) == VAR_DECL)
1921 /* A static data member. */
1923 /* If OBJECT has side-effects, they are supposed to occur. */
1924 if (TREE_SIDE_EFFECTS (object))
1925 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1927 else if (TREE_CODE (member) == FIELD_DECL)
1929 /* A non-static data member. */
1934 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1935 && integer_zerop (TREE_OPERAND (object, 0)));
1937 /* Convert OBJECT to the type of MEMBER. */
1938 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1939 TYPE_MAIN_VARIANT (member_scope)))
1944 binfo = lookup_base (access_path ? access_path : object_type,
1945 member_scope, ba_unique, &kind);
1946 if (binfo == error_mark_node)
1947 return error_mark_node;
1949 /* It is invalid to try to get to a virtual base of a
1950 NULL object. The most common cause is invalid use of
1952 if (null_object_p && kind == bk_via_virtual)
1954 if (complain & tf_error)
1956 error ("invalid access to non-static data member %qD of "
1959 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1961 return error_mark_node;
1964 /* Convert to the base. */
1965 object = build_base_path (PLUS_EXPR, object, binfo,
1967 /* If we found the base successfully then we should be able
1968 to convert to it successfully. */
1969 gcc_assert (object != error_mark_node);
1972 /* Complain about other invalid uses of offsetof, even though they will
1973 give the right answer. Note that we complain whether or not they
1974 actually used the offsetof macro, since there's no way to know at this
1975 point. So we just give a warning, instead of a pedwarn. */
1976 /* Do not produce this warning for base class field references, because
1977 we know for a fact that didn't come from offsetof. This does occur
1978 in various testsuite cases where a null object is passed where a
1979 vtable access is required. */
1980 if (null_object_p && warn_invalid_offsetof
1981 && CLASSTYPE_NON_POD_P (object_type)
1982 && !DECL_FIELD_IS_BASE (member)
1984 && (complain & tf_warning))
1986 warning (OPT_Winvalid_offsetof,
1987 "invalid access to non-static data member %qD "
1988 " of NULL object", member);
1989 warning (OPT_Winvalid_offsetof,
1990 "(perhaps the %<offsetof%> macro was used incorrectly)");
1993 /* If MEMBER is from an anonymous aggregate, we have converted
1994 OBJECT so that it refers to the class containing the
1995 anonymous union. Generate a reference to the anonymous union
1996 itself, and recur to find MEMBER. */
1997 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1998 /* When this code is called from build_field_call, the
1999 object already has the type of the anonymous union.
2000 That is because the COMPONENT_REF was already
2001 constructed, and was then disassembled before calling
2002 build_field_call. After the function-call code is
2003 cleaned up, this waste can be eliminated. */
2004 && (!same_type_ignoring_top_level_qualifiers_p
2005 (TREE_TYPE (object), DECL_CONTEXT (member))))
2007 tree anonymous_union;
2009 anonymous_union = lookup_anon_field (TREE_TYPE (object),
2010 DECL_CONTEXT (member));
2011 object = build_class_member_access_expr (object,
2013 /*access_path=*/NULL_TREE,
2018 /* Compute the type of the field, as described in [expr.ref]. */
2019 type_quals = TYPE_UNQUALIFIED;
2020 member_type = TREE_TYPE (member);
2021 if (TREE_CODE (member_type) != REFERENCE_TYPE)
2023 type_quals = (cp_type_quals (member_type)
2024 | cp_type_quals (object_type));
2026 /* A field is const (volatile) if the enclosing object, or the
2027 field itself, is const (volatile). But, a mutable field is
2028 not const, even within a const object. */
2029 if (DECL_MUTABLE_P (member))
2030 type_quals &= ~TYPE_QUAL_CONST;
2031 member_type = cp_build_qualified_type (member_type, type_quals);
2034 result = build3 (COMPONENT_REF, member_type, object, member,
2036 result = fold_if_not_in_template (result);
2038 /* Mark the expression const or volatile, as appropriate. Even
2039 though we've dealt with the type above, we still have to mark the
2040 expression itself. */
2041 if (type_quals & TYPE_QUAL_CONST)
2042 TREE_READONLY (result) = 1;
2043 if (type_quals & TYPE_QUAL_VOLATILE)
2044 TREE_THIS_VOLATILE (result) = 1;
2046 else if (BASELINK_P (member))
2048 /* The member is a (possibly overloaded) member function. */
2052 /* If the MEMBER is exactly one static member function, then we
2053 know the type of the expression. Otherwise, we must wait
2054 until overload resolution has been performed. */
2055 functions = BASELINK_FUNCTIONS (member);
2056 if (TREE_CODE (functions) == FUNCTION_DECL
2057 && DECL_STATIC_FUNCTION_P (functions))
2058 type = TREE_TYPE (functions);
2060 type = unknown_type_node;
2061 /* Note that we do not convert OBJECT to the BASELINK_BINFO
2062 base. That will happen when the function is called. */
2063 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
2065 else if (TREE_CODE (member) == CONST_DECL)
2067 /* The member is an enumerator. */
2069 /* If OBJECT has side-effects, they are supposed to occur. */
2070 if (TREE_SIDE_EFFECTS (object))
2071 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2076 if (complain & tf_error)
2077 error ("invalid use of %qD", member);
2078 return error_mark_node;
2081 if (!preserve_reference)
2084 If E2 is declared to have type "reference to T", then ... the
2085 type of E1.E2 is T. */
2086 result = convert_from_reference (result);
2091 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
2092 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2095 lookup_destructor (tree object, tree scope, tree dtor_name)
2097 tree object_type = TREE_TYPE (object);
2098 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2101 if (scope && !check_dtor_name (scope, dtor_type))
2103 error ("qualified type %qT does not match destructor name ~%qT",
2105 return error_mark_node;
2107 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2109 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2110 TYPE_MAIN_VARIANT (object_type), dtor_type);
2111 return error_mark_node;
2113 expr = lookup_member (dtor_type, complete_dtor_identifier,
2114 /*protect=*/1, /*want_type=*/false);
2115 expr = (adjust_result_of_qualified_name_lookup
2116 (expr, dtor_type, object_type));
2120 /* An expression of the form "A::template B" has been resolved to
2121 DECL. Issue a diagnostic if B is not a template or template
2125 check_template_keyword (tree decl)
2127 /* The standard says:
2131 If a name prefixed by the keyword template is not a member
2132 template, the program is ill-formed.
2134 DR 228 removed the restriction that the template be a member
2137 DR 96, if accepted would add the further restriction that explicit
2138 template arguments must be provided if the template keyword is
2139 used, but, as of 2005-10-16, that DR is still in "drafting". If
2140 this DR is accepted, then the semantic checks here can be
2141 simplified, as the entity named must in fact be a template
2142 specialization, rather than, as at present, a set of overloaded
2143 functions containing at least one template function. */
2144 if (TREE_CODE (decl) != TEMPLATE_DECL
2145 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2147 if (!is_overloaded_fn (decl))
2148 pedwarn ("%qD is not a template", decl);
2153 if (BASELINK_P (fns))
2154 fns = BASELINK_FUNCTIONS (fns);
2157 tree fn = OVL_CURRENT (fns);
2158 if (TREE_CODE (fn) == TEMPLATE_DECL
2159 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2161 if (TREE_CODE (fn) == FUNCTION_DECL
2162 && DECL_USE_TEMPLATE (fn)
2163 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2165 fns = OVL_NEXT (fns);
2168 pedwarn ("%qD is not a template", decl);
2173 /* This function is called by the parser to process a class member
2174 access expression of the form OBJECT.NAME. NAME is a node used by
2175 the parser to represent a name; it is not yet a DECL. It may,
2176 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2177 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2178 there is no reason to do the lookup twice, so the parser keeps the
2179 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2180 be a template via the use of the "A::template B" syntax. */
2183 finish_class_member_access_expr (tree object, tree name, bool template_p,
2184 tsubst_flags_t complain)
2189 tree access_path = NULL_TREE;
2190 tree orig_object = object;
2191 tree orig_name = name;
2193 if (object == error_mark_node || name == error_mark_node)
2194 return error_mark_node;
2196 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2197 if (!objc_is_public (object, name))
2198 return error_mark_node;
2200 object_type = TREE_TYPE (object);
2202 if (processing_template_decl)
2204 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2205 dependent_type_p (object_type)
2206 /* If NAME is just an IDENTIFIER_NODE, then the expression
2208 || TREE_CODE (object) == IDENTIFIER_NODE
2209 /* If NAME is "f<args>", where either 'f' or 'args' is
2210 dependent, then the expression is dependent. */
2211 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2212 && dependent_template_id_p (TREE_OPERAND (name, 0),
2213 TREE_OPERAND (name, 1)))
2214 /* If NAME is "T::X" where "T" is dependent, then the
2215 expression is dependent. */
2216 || (TREE_CODE (name) == SCOPE_REF
2217 && TYPE_P (TREE_OPERAND (name, 0))
2218 && dependent_type_p (TREE_OPERAND (name, 0))))
2219 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2220 object = build_non_dependent_expr (object);
2225 The type of the first expression shall be "class object" (of a
2227 if (!currently_open_class (object_type)
2228 && !complete_type_or_else (object_type, object))
2229 return error_mark_node;
2230 if (!CLASS_TYPE_P (object_type))
2232 if (complain & tf_error)
2233 error ("request for member %qD in %qE, which is of non-class type %qT",
2234 name, object, object_type);
2235 return error_mark_node;
2238 if (BASELINK_P (name))
2239 /* A member function that has already been looked up. */
2243 bool is_template_id = false;
2244 tree template_args = NULL_TREE;
2247 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2249 is_template_id = true;
2250 template_args = TREE_OPERAND (name, 1);
2251 name = TREE_OPERAND (name, 0);
2253 if (TREE_CODE (name) == OVERLOAD)
2254 name = DECL_NAME (get_first_fn (name));
2255 else if (DECL_P (name))
2256 name = DECL_NAME (name);
2259 if (TREE_CODE (name) == SCOPE_REF)
2261 /* A qualified name. The qualifying class or namespace `S'
2262 has already been looked up; it is either a TYPE or a
2264 scope = TREE_OPERAND (name, 0);
2265 name = TREE_OPERAND (name, 1);
2267 /* If SCOPE is a namespace, then the qualified name does not
2268 name a member of OBJECT_TYPE. */
2269 if (TREE_CODE (scope) == NAMESPACE_DECL)
2271 if (complain & tf_error)
2272 error ("%<%D::%D%> is not a member of %qT",
2273 scope, name, object_type);
2274 return error_mark_node;
2277 gcc_assert (CLASS_TYPE_P (scope));
2278 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2279 || TREE_CODE (name) == BIT_NOT_EXPR);
2281 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2282 access_path = lookup_base (object_type, scope, ba_check, NULL);
2283 if (access_path == error_mark_node)
2284 return error_mark_node;
2287 if (complain & tf_error)
2288 error ("%qT is not a base of %qT", scope, object_type);
2289 return error_mark_node;
2295 access_path = object_type;
2298 if (TREE_CODE (name) == BIT_NOT_EXPR)
2299 member = lookup_destructor (object, scope, name);
2302 /* Look up the member. */
2303 member = lookup_member (access_path, name, /*protect=*/1,
2304 /*want_type=*/false);
2305 if (member == NULL_TREE)
2307 if (complain & tf_error)
2308 error ("%qD has no member named %qE", object_type, name);
2309 return error_mark_node;
2311 if (member == error_mark_node)
2312 return error_mark_node;
2317 tree template = member;
2319 if (BASELINK_P (template))
2320 template = lookup_template_function (template, template_args);
2323 if (complain & tf_error)
2324 error ("%qD is not a member template function", name);
2325 return error_mark_node;
2330 if (TREE_DEPRECATED (member))
2331 warn_deprecated_use (member);
2334 check_template_keyword (member);
2336 expr = build_class_member_access_expr (object, member, access_path,
2337 /*preserve_reference=*/false,
2339 if (processing_template_decl && expr != error_mark_node)
2341 if (BASELINK_P (member))
2343 if (TREE_CODE (orig_name) == SCOPE_REF)
2344 BASELINK_QUALIFIED_P (member) = 1;
2347 return build_min_non_dep (COMPONENT_REF, expr,
2348 orig_object, orig_name,
2355 /* Return an expression for the MEMBER_NAME field in the internal
2356 representation of PTRMEM, a pointer-to-member function. (Each
2357 pointer-to-member function type gets its own RECORD_TYPE so it is
2358 more convenient to access the fields by name than by FIELD_DECL.)
2359 This routine converts the NAME to a FIELD_DECL and then creates the
2360 node for the complete expression. */
2363 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2369 /* This code is a stripped down version of
2370 build_class_member_access_expr. It does not work to use that
2371 routine directly because it expects the object to be of class
2373 ptrmem_type = TREE_TYPE (ptrmem);
2374 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2375 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2376 /*want_type=*/false);
2377 member_type = cp_build_qualified_type (TREE_TYPE (member),
2378 cp_type_quals (ptrmem_type));
2379 return fold_build3 (COMPONENT_REF, member_type,
2380 ptrmem, member, NULL_TREE);
2383 /* Given an expression PTR for a pointer, return an expression
2384 for the value pointed to.
2385 ERRORSTRING is the name of the operator to appear in error messages.
2387 This function may need to overload OPERATOR_FNNAME.
2388 Must also handle REFERENCE_TYPEs for C++. */
2391 build_x_indirect_ref (tree expr, const char *errorstring,
2392 tsubst_flags_t complain)
2394 tree orig_expr = expr;
2397 if (processing_template_decl)
2399 if (type_dependent_expression_p (expr))
2400 return build_min_nt (INDIRECT_REF, expr);
2401 expr = build_non_dependent_expr (expr);
2404 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2405 NULL_TREE, /*overloaded_p=*/NULL, complain);
2407 rval = cp_build_indirect_ref (expr, errorstring, complain);
2409 if (processing_template_decl && rval != error_mark_node)
2410 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2415 /* Helper function called from c-common. */
2417 build_indirect_ref (tree ptr, const char *errorstring)
2419 return cp_build_indirect_ref (ptr, errorstring, tf_warning_or_error);
2423 cp_build_indirect_ref (tree ptr, const char *errorstring,
2424 tsubst_flags_t complain)
2428 if (ptr == error_mark_node)
2429 return error_mark_node;
2431 if (ptr == current_class_ptr)
2432 return current_class_ref;
2434 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2435 ? ptr : decay_conversion (ptr));
2436 type = TREE_TYPE (pointer);
2438 if (POINTER_TYPE_P (type))
2442 If the type of the expression is "pointer to T," the type
2443 of the result is "T."
2445 We must use the canonical variant because certain parts of
2446 the back end, like fold, do pointer comparisons between
2448 tree t = canonical_type_variant (TREE_TYPE (type));
2450 if (TREE_CODE (ptr) == CONVERT_EXPR
2451 || TREE_CODE (ptr) == NOP_EXPR
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;
2767 TREE_INVARIANT (e2) = 1;
2769 /* When using function descriptors, the address of the
2770 vtable entry is treated as a function pointer. */
2771 if (TARGET_VTABLE_USES_DESCRIPTORS)
2772 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2773 cp_build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1,
2774 tf_warning_or_error));
2776 e2 = fold_convert (TREE_TYPE (e3), e2);
2777 e1 = build_conditional_expr (e1, e2, e3, tf_warning_or_error);
2779 /* Make sure this doesn't get evaluated first inside one of the
2780 branches of the COND_EXPR. */
2781 if (instance_save_expr)
2782 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2783 instance_save_expr, e1);
2790 /* Used by the C-common bits. */
2792 build_function_call (tree function, tree params)
2794 return cp_build_function_call (function, params, tf_warning_or_error);
2798 cp_build_function_call (tree function, tree params, tsubst_flags_t complain)
2800 tree fntype, fndecl;
2801 tree name = NULL_TREE;
2803 tree original = function;
2804 int nargs, parm_types_len;
2808 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2809 expressions, like those used for ObjC messenger dispatches. */
2810 function = objc_rewrite_function_call (function, params);
2812 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2813 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2814 if (TREE_CODE (function) == NOP_EXPR
2815 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2816 function = TREE_OPERAND (function, 0);
2818 if (TREE_CODE (function) == FUNCTION_DECL)
2820 name = DECL_NAME (function);
2822 mark_used (function);
2825 /* Convert anything with function type to a pointer-to-function. */
2826 if (pedantic && DECL_MAIN_P (function) && (complain & tf_error))
2827 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2829 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2830 (because calling an inline function does not mean the function
2831 needs to be separately compiled). */
2833 if (DECL_INLINE (function))
2834 function = inline_conversion (function);
2836 function = build_addr_func (function);
2842 function = build_addr_func (function);
2845 if (function == error_mark_node)
2846 return error_mark_node;
2848 fntype = TREE_TYPE (function);
2850 if (TYPE_PTRMEMFUNC_P (fntype))
2852 if (complain & tf_error)
2853 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2854 "function in %<%E (...)%>",
2856 return error_mark_node;
2859 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2860 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2862 if (!((TREE_CODE (fntype) == POINTER_TYPE
2863 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2865 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2867 if (complain & tf_error)
2868 error ("%qE cannot be used as a function", original);
2869 return error_mark_node;
2872 /* fntype now gets the type of function pointed to. */
2873 fntype = TREE_TYPE (fntype);
2874 parm_types = TYPE_ARG_TYPES (fntype);
2876 /* Allocate storage for converted arguments. */
2877 parm_types_len = list_length (parm_types);
2878 nargs = list_length (params);
2879 if (parm_types_len > nargs)
2880 nargs = parm_types_len;
2881 argarray = (tree *) alloca (nargs * sizeof (tree));
2883 /* Convert the parameters to the types declared in the
2884 function prototype, or apply default promotions. */
2885 nargs = convert_arguments (nargs, argarray, parm_types,
2886 params, fndecl, LOOKUP_NORMAL,
2889 return error_mark_node;
2891 /* Check for errors in format strings and inappropriately
2894 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2897 return build_cxx_call (function, nargs, argarray);
2900 /* Convert the actual parameter expressions in the list VALUES
2901 to the types in the list TYPELIST.
2902 If parmdecls is exhausted, or when an element has NULL as its type,
2903 perform the default conversions.
2905 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2907 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2909 This is also where warnings about wrong number of args are generated.
2911 Returns the actual number of arguments processed (which might be less
2912 than NARGS), or -1 on error.
2914 VALUES is a chain of TREE_LIST nodes with the elements of the list
2915 in the TREE_VALUE slots of those nodes.
2917 In C++, unspecified trailing parameters can be filled in with their
2918 default arguments, if such were specified. Do so here. */
2921 convert_arguments (int nargs, tree *argarray,
2922 tree typelist, tree values, tree fndecl, int flags,
2923 tsubst_flags_t complain)
2925 tree typetail, valtail;
2926 const char *called_thing = 0;
2929 /* Argument passing is always copy-initialization. */
2930 flags |= LOOKUP_ONLYCONVERTING;
2934 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2936 if (DECL_NAME (fndecl) == NULL_TREE
2937 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2938 called_thing = "constructor";
2940 called_thing = "member function";
2943 called_thing = "function";
2946 for (valtail = values, typetail = typelist;
2948 valtail = TREE_CHAIN (valtail), i++)
2950 tree type = typetail ? TREE_VALUE (typetail) : 0;
2951 tree val = TREE_VALUE (valtail);
2953 if (val == error_mark_node || type == error_mark_node)
2956 if (type == void_type_node)
2958 if (complain & tf_error)
2962 error ("too many arguments to %s %q+#D",
2963 called_thing, fndecl);
2964 error ("at this point in file");
2967 error ("too many arguments to function");
2974 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2975 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2976 if (TREE_CODE (val) == NOP_EXPR
2977 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2978 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2979 val = TREE_OPERAND (val, 0);
2981 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2983 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2984 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2985 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2986 val = decay_conversion (val);
2989 if (val == error_mark_node)
2994 /* Formal parm type is specified by a function prototype. */
2997 if (!COMPLETE_TYPE_P (complete_type (type)))
2999 if (complain & tf_error)
3002 error ("parameter %P of %qD has incomplete type %qT",
3005 error ("parameter %P has incomplete type %qT", i, type);
3007 parmval = error_mark_node;
3011 parmval = convert_for_initialization
3012 (NULL_TREE, type, val, flags,
3013 "argument passing", fndecl, i, complain);
3014 parmval = convert_for_arg_passing (type, parmval);
3017 if (parmval == error_mark_node)
3020 argarray[i] = parmval;
3024 if (fndecl && DECL_BUILT_IN (fndecl)
3025 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
3026 /* Don't do ellipsis conversion for __built_in_constant_p
3027 as this will result in spurious warnings for non-POD
3029 val = require_complete_type (val);
3031 val = convert_arg_to_ellipsis (val);
3037 typetail = TREE_CHAIN (typetail);
3040 if (typetail != 0 && typetail != void_list_node)
3042 /* See if there are default arguments that can be used. Because
3043 we hold default arguments in the FUNCTION_TYPE (which is so
3044 wrong), we can see default parameters here from deduced
3045 contexts (and via typeof) for indirect function calls.
3046 Fortunately we know whether we have a function decl to
3047 provide default arguments in a language conformant
3049 if (fndecl && TREE_PURPOSE (typetail)
3050 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
3052 for (; typetail != void_list_node; ++i)
3055 = convert_default_arg (TREE_VALUE (typetail),
3056 TREE_PURPOSE (typetail),
3059 if (parmval == error_mark_node)
3062 argarray[i] = parmval;
3063 typetail = TREE_CHAIN (typetail);
3064 /* ends with `...'. */
3065 if (typetail == NULL_TREE)
3071 if (complain & tf_error)
3075 error ("too few arguments to %s %q+#D",
3076 called_thing, fndecl);
3077 error ("at this point in file");
3080 error ("too few arguments to function");
3086 gcc_assert (i <= nargs);
3090 /* Build a binary-operation expression, after performing default
3091 conversions on the operands. CODE is the kind of expression to
3092 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
3093 are the tree codes which correspond to ARG1 and ARG2 when issuing
3094 warnings about possibly misplaced parentheses. They may differ
3095 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
3096 folding (e.g., if the parser sees "a | 1 + 1", it may call this
3097 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
3098 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
3099 ARG2_CODE as ERROR_MARK. */
3102 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
3103 tree arg2, enum tree_code arg2_code, bool *overloaded_p,
3104 tsubst_flags_t complain)
3113 if (processing_template_decl)
3115 if (type_dependent_expression_p (arg1)
3116 || type_dependent_expression_p (arg2))
3117 return build_min_nt (code, arg1, arg2);
3118 arg1 = build_non_dependent_expr (arg1);
3119 arg2 = build_non_dependent_expr (arg2);
3122 if (code == DOTSTAR_EXPR)
3123 expr = build_m_component_ref (arg1, arg2);
3125 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3126 overloaded_p, complain);
3128 /* Check for cases such as x+y<<z which users are likely to
3129 misinterpret. But don't warn about obj << x + y, since that is a
3130 common idiom for I/O. */
3131 if (warn_parentheses
3132 && !processing_template_decl
3133 && !error_operand_p (arg1)
3134 && !error_operand_p (arg2)
3135 && (code != LSHIFT_EXPR
3136 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
3137 warn_about_parentheses (code, arg1_code, arg2_code);
3139 if (processing_template_decl && expr != error_mark_node)
3140 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
3145 /* For the c-common bits. */
3147 build_binary_op (enum tree_code code, tree op0, tree op1,
3148 int convert_p ATTRIBUTE_UNUSED)
3150 return cp_build_binary_op(code, op0, op1, tf_warning_or_error);
3154 /* Build a binary-operation expression without default conversions.
3155 CODE is the kind of expression to build.
3156 This function differs from `build' in several ways:
3157 the data type of the result is computed and recorded in it,
3158 warnings are generated if arg data types are invalid,
3159 special handling for addition and subtraction of pointers is known,
3160 and some optimization is done (operations on narrow ints
3161 are done in the narrower type when that gives the same result).
3162 Constant folding is also done before the result is returned.
3164 Note that the operands will never have enumeral types
3165 because either they have just had the default conversions performed
3166 or they have both just been converted to some other type in which
3167 the arithmetic is to be done.
3169 C++: must do special pointer arithmetic when implementing
3170 multiple inheritance, and deal with pointer to member functions. */
3173 cp_build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3174 tsubst_flags_t complain)
3177 enum tree_code code0, code1;
3179 const char *invalid_op_diag;
3181 /* Expression code to give to the expression when it is built.
3182 Normally this is CODE, which is what the caller asked for,
3183 but in some special cases we change it. */
3184 enum tree_code resultcode = code;
3186 /* Data type in which the computation is to be performed.
3187 In the simplest cases this is the common type of the arguments. */
3188 tree result_type = NULL;
3190 /* Nonzero means operands have already been type-converted
3191 in whatever way is necessary.
3192 Zero means they need to be converted to RESULT_TYPE. */
3195 /* Nonzero means create the expression with this type, rather than
3197 tree build_type = 0;
3199 /* Nonzero means after finally constructing the expression
3200 convert it to this type. */
3201 tree final_type = 0;
3205 /* Nonzero if this is an operation like MIN or MAX which can
3206 safely be computed in short if both args are promoted shorts.
3207 Also implies COMMON.
3208 -1 indicates a bitwise operation; this makes a difference
3209 in the exact conditions for when it is safe to do the operation
3210 in a narrower mode. */
3213 /* Nonzero if this is a comparison operation;
3214 if both args are promoted shorts, compare the original shorts.
3215 Also implies COMMON. */
3216 int short_compare = 0;
3218 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3221 /* True if both operands have arithmetic type. */
3222 bool arithmetic_types_p;
3224 /* Apply default conversions. */
3228 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3229 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3230 || code == TRUTH_XOR_EXPR)
3232 if (!really_overloaded_fn (op0))
3233 op0 = decay_conversion (op0);
3234 if (!really_overloaded_fn (op1))
3235 op1 = decay_conversion (op1);
3239 if (!really_overloaded_fn (op0))
3240 op0 = default_conversion (op0);
3241 if (!really_overloaded_fn (op1))
3242 op1 = default_conversion (op1);
3245 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3246 STRIP_TYPE_NOPS (op0);
3247 STRIP_TYPE_NOPS (op1);
3249 /* DTRT if one side is an overloaded function, but complain about it. */
3250 if (type_unknown_p (op0))
3252 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3253 if (t != error_mark_node)
3255 if (complain & tf_error)
3256 pedwarn ("assuming cast to type %qT from overloaded function",
3261 if (type_unknown_p (op1))
3263 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3264 if (t != error_mark_node)
3266 if (complain & tf_error)
3267 pedwarn ("assuming cast to type %qT from overloaded function",
3273 type0 = TREE_TYPE (op0);
3274 type1 = TREE_TYPE (op1);
3276 /* The expression codes of the data types of the arguments tell us
3277 whether the arguments are integers, floating, pointers, etc. */
3278 code0 = TREE_CODE (type0);
3279 code1 = TREE_CODE (type1);
3281 /* If an error was already reported for one of the arguments,
3282 avoid reporting another error. */
3284 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3285 return error_mark_node;
3287 if ((invalid_op_diag
3288 = targetm.invalid_binary_op (code, type0, type1)))
3290 error (invalid_op_diag);
3291 return error_mark_node;
3297 /* Subtraction of two similar pointers.
3298 We must subtract them as integers, then divide by object size. */
3299 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3300 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3302 return pointer_diff (op0, op1, common_type (type0, type1));
3303 /* In all other cases except pointer - int, the usual arithmetic
3305 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3310 /* The pointer - int case is just like pointer + int; fall
3313 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3314 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3318 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3319 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3320 if (processing_template_decl)
3322 result_type = TREE_TYPE (ptr_operand);
3325 return cp_pointer_int_sum (code,
3336 case TRUNC_DIV_EXPR:
3338 case FLOOR_DIV_EXPR:
3339 case ROUND_DIV_EXPR:
3340 case EXACT_DIV_EXPR:
3341 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3342 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3343 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3344 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3346 enum tree_code tcode0 = code0, tcode1 = code1;
3348 warn_for_div_by_zero (op1);
3350 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3351 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3352 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3353 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3355 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3356 resultcode = RDIV_EXPR;
3358 /* When dividing two signed integers, we have to promote to int.
3359 unless we divide by a constant != -1. Note that default
3360 conversion will have been performed on the operands at this
3361 point, so we have to dig out the original type to find out if
3363 shorten = ((TREE_CODE (op0) == NOP_EXPR
3364 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3365 || (TREE_CODE (op1) == INTEGER_CST
3366 && ! integer_all_onesp (op1)));
3375 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3376 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3377 && !VECTOR_FLOAT_TYPE_P (type0)
3378 && !VECTOR_FLOAT_TYPE_P (type1)))
3382 case TRUNC_MOD_EXPR:
3383 case FLOOR_MOD_EXPR:
3384 warn_for_div_by_zero (op1);
3386 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3388 /* Although it would be tempting to shorten always here, that loses
3389 on some targets, since the modulo instruction is undefined if the
3390 quotient can't be represented in the computation mode. We shorten
3391 only if unsigned or if dividing by something we know != -1. */
3392 shorten = ((TREE_CODE (op0) == NOP_EXPR
3393 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3394 || (TREE_CODE (op1) == INTEGER_CST
3395 && ! integer_all_onesp (op1)));
3400 case TRUTH_ANDIF_EXPR:
3401 case TRUTH_ORIF_EXPR:
3402 case TRUTH_AND_EXPR:
3404 result_type = boolean_type_node;
3407 /* Shift operations: result has same type as first operand;
3408 always convert second operand to int.
3409 Also set SHORT_SHIFT if shifting rightward. */
3412 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3414 result_type = type0;
3415 if (TREE_CODE (op1) == INTEGER_CST)
3417 if (tree_int_cst_lt (op1, integer_zero_node))
3419 if (complain & tf_warning)
3420 warning (0, "right shift count is negative");
3424 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0
3425 && (complain & tf_warning))
3426 warning (0, "right shift count >= width of type");
3429 /* Convert the shift-count to an integer, regardless of
3430 size of value being shifted. */
3431 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3432 op1 = cp_convert (integer_type_node, op1);
3433 /* Avoid converting op1 to result_type later. */
3439 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3441 result_type = type0;
3442 if (TREE_CODE (op1) == INTEGER_CST)
3444 if (tree_int_cst_lt (op1, integer_zero_node))
3446 if (complain & tf_warning)
3447 warning (0, "left shift count is negative");
3449 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3451 if (complain & tf_warning)
3452 warning (0, "left shift count >= width of type");
3455 /* Convert the shift-count to an integer, regardless of
3456 size of value being shifted. */
3457 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3458 op1 = cp_convert (integer_type_node, op1);
3459 /* Avoid converting op1 to result_type later. */
3466 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3468 result_type = type0;
3469 if (TREE_CODE (op1) == INTEGER_CST)
3471 if (tree_int_cst_lt (op1, integer_zero_node))
3473 if (complain & tf_warning)
3474 warning (0, (code == LROTATE_EXPR)
3475 ? G_("left rotate count is negative")
3476 : G_("right rotate count is negative"));
3478 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3480 if (complain & tf_warning)
3481 warning (0, (code == LROTATE_EXPR)
3482 ? G_("left rotate count >= width of type")
3483 : G_("right rotate count >= width of type"));
3486 /* Convert the shift-count to an integer, regardless of
3487 size of value being shifted. */
3488 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3489 op1 = cp_convert (integer_type_node, op1);
3495 if ((complain & tf_warning)
3496 && (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1)))
3497 warning (OPT_Wfloat_equal,
3498 "comparing floating point with == or != is unsafe");
3499 if ((complain & tf_warning)
3500 && ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3501 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0))))
3502 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3504 build_type = boolean_type_node;
3505 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3506 || code0 == COMPLEX_TYPE)
3507 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3508 || code1 == COMPLEX_TYPE))
3510 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3511 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3512 result_type = composite_pointer_type (type0, type1, op0, op1,
3513 "comparison", complain);
3514 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3515 && null_ptr_cst_p (op1))
3517 if (TREE_CODE (op0) == ADDR_EXPR
3518 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3520 if (complain & tf_warning)
3521 warning (OPT_Waddress, "the address of %qD will never be NULL",
3522 TREE_OPERAND (op0, 0));
3524 result_type = type0;
3526 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3527 && null_ptr_cst_p (op0))
3529 if (TREE_CODE (op1) == ADDR_EXPR
3530 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3532 if (complain & tf_warning)
3533 warning (OPT_Waddress, "the address of %qD will never be NULL",
3534 TREE_OPERAND (op1, 0));
3536 result_type = type1;
3538 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3540 result_type = type0;
3541 if (complain & tf_error)
3542 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3544 return error_mark_node;
3546 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3548 result_type = type1;
3549 if (complain & tf_error)
3550 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3552 return error_mark_node;
3554 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3556 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3557 == ptrmemfunc_vbit_in_delta)
3559 tree pfn0 = pfn_from_ptrmemfunc (op0);
3560 tree delta0 = delta_from_ptrmemfunc (op0);
3561 tree e1 = cp_build_binary_op (EQ_EXPR,
3563 fold_convert (TREE_TYPE (pfn0),
3566 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3570 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3572 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2,
3574 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3578 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3579 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3581 result_type = TREE_TYPE (op0);
3583 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3584 return cp_build_binary_op (code, op1, op0, complain);
3585 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1))
3588 /* E will be the final comparison. */
3590 /* E1 and E2 are for scratch. */
3598 type = composite_pointer_type (type0, type1, op0, op1, "comparison",
3601 if (!same_type_p (TREE_TYPE (op0), type))
3602 op0 = cp_convert_and_check (type, op0);
3603 if (!same_type_p (TREE_TYPE (op1), type))
3604 op1 = cp_convert_and_check (type, op1);
3606 if (op0 == error_mark_node || op1 == error_mark_node)
3607 return error_mark_node;
3609 if (TREE_SIDE_EFFECTS (op0))
3610 op0 = save_expr (op0);
3611 if (TREE_SIDE_EFFECTS (op1))
3612 op1 = save_expr (op1);
3614 pfn0 = pfn_from_ptrmemfunc (op0);
3615 pfn1 = pfn_from_ptrmemfunc (op1);
3616 delta0 = delta_from_ptrmemfunc (op0);
3617 delta1 = delta_from_ptrmemfunc (op1);
3618 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3619 == ptrmemfunc_vbit_in_delta)
3624 && ((op0.delta == op1.delta)
3625 || (!op0.pfn && op0.delta & 1 == 0
3626 && op1.delta & 1 == 0))
3628 The reason for the `!op0.pfn' bit is that a NULL
3629 pointer-to-member is any member with a zero PFN and
3630 LSB of the DELTA field is 0. */
3632 e1 = cp_build_binary_op (BIT_AND_EXPR,
3636 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node,
3638 e2 = cp_build_binary_op (BIT_AND_EXPR,
3642 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node,
3644 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1,
3646 e2 = cp_build_binary_op (EQ_EXPR,
3648 fold_convert (TREE_TYPE (pfn0),
3651 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3652 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3653 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3660 && (!op0.pfn || op0.delta == op1.delta))
3662 The reason for the `!op0.pfn' bit is that a NULL
3663 pointer-to-member is any member with a zero PFN; the
3664 DELTA field is unspecified. */
3666 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1, complain);
3667 e2 = cp_build_binary_op (EQ_EXPR,
3669 fold_convert (TREE_TYPE (pfn0),
3672 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2, complain);
3674 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3675 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1, complain);
3676 if (code == EQ_EXPR)
3678 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node, complain);
3682 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3683 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3685 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3686 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3694 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3695 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3697 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3698 result_type = composite_pointer_type (type0, type1, op0, op1,
3699 "comparison", complain);
3706 if (TREE_CODE (orig_op0) == STRING_CST
3707 || TREE_CODE (orig_op1) == STRING_CST)
3709 if (complain & tf_warning)
3710 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3713 build_type = boolean_type_node;
3714 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3715 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3717 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3718 result_type = composite_pointer_type (type0, type1, op0, op1,
3719 "comparison", complain);
3720 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3721 && integer_zerop (op1))
3722 result_type = type0;
3723 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3724 && integer_zerop (op0))
3725 result_type = type1;
3726 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3728 result_type = type0;
3729 if (complain & tf_error)
3730 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3732 return error_mark_node;
3734 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3736 result_type = type1;
3737 if (complain & tf_error)
3738 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3740 return error_mark_node;
3744 case UNORDERED_EXPR:
3751 build_type = integer_type_node;
3752 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3754 if (complain & tf_error)
3755 error ("unordered comparison on non-floating point argument");
3756 return error_mark_node;
3765 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3766 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3767 || code1 == COMPLEX_TYPE)))
3768 arithmetic_types_p = 1;
3771 arithmetic_types_p = 0;
3772 /* Vector arithmetic is only allowed when both sides are vectors. */
3773 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3775 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3776 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3779 binary_op_error (code, type0, type1);
3780 return error_mark_node;
3782 arithmetic_types_p = 1;
3785 /* Determine the RESULT_TYPE, if it is not already known. */
3787 && arithmetic_types_p
3788 && (shorten || common || short_compare))
3789 result_type = common_type (type0, type1);
3793 if (complain & tf_error)
3794 error ("invalid operands of types %qT and %qT to binary %qO",
3795 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3796 return error_mark_node;
3799 /* If we're in a template, the only thing we need to know is the
3801 if (processing_template_decl)
3803 /* Since the middle-end checks the type when doing a build2, we
3804 need to build the tree in pieces. This built tree will never
3805 get out of the front-end as we replace it when instantiating
3807 tree tmp = build2 (resultcode,
3808 build_type ? build_type : result_type,
3810 TREE_OPERAND (tmp, 0) = op0;
3814 if (arithmetic_types_p)
3816 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3818 /* For certain operations (which identify themselves by shorten != 0)
3819 if both args were extended from the same smaller type,
3820 do the arithmetic in that type and then extend.
3822 shorten !=0 and !=1 indicates a bitwise operation.
3823 For them, this optimization is safe only if
3824 both args are zero-extended or both are sign-extended.
3825 Otherwise, we might change the result.
3826 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3827 but calculated in (unsigned short) it would be (unsigned short)-1. */
3829 if (shorten && none_complex)
3831 int unsigned0, unsigned1;
3832 tree arg0 = get_narrower (op0, &unsigned0);
3833 tree arg1 = get_narrower (op1, &unsigned1);
3834 /* UNS is 1 if the operation to be done is an unsigned one. */
3835 int uns = TYPE_UNSIGNED (result_type);
3838 final_type = result_type;
3840 /* Handle the case that OP0 does not *contain* a conversion
3841 but it *requires* conversion to FINAL_TYPE. */
3843 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3844 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3845 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3846 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3848 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3850 /* For bitwise operations, signedness of nominal type
3851 does not matter. Consider only how operands were extended. */
3855 /* Note that in all three cases below we refrain from optimizing
3856 an unsigned operation on sign-extended args.
3857 That would not be valid. */
3859 /* Both args variable: if both extended in same way
3860 from same width, do it in that width.
3861 Do it unsigned if args were zero-extended. */
3862 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3863 < TYPE_PRECISION (result_type))
3864 && (TYPE_PRECISION (TREE_TYPE (arg1))
3865 == TYPE_PRECISION (TREE_TYPE (arg0)))
3866 && unsigned0 == unsigned1
3867 && (unsigned0 || !uns))
3868 result_type = c_common_signed_or_unsigned_type
3869 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3870 else if (TREE_CODE (arg0) == INTEGER_CST
3871 && (unsigned1 || !uns)
3872 && (TYPE_PRECISION (TREE_TYPE (arg1))
3873 < TYPE_PRECISION (result_type))
3874 && (type = c_common_signed_or_unsigned_type
3875 (unsigned1, TREE_TYPE (arg1)),
3876 int_fits_type_p (arg0, type)))
3878 else if (TREE_CODE (arg1) == INTEGER_CST
3879 && (unsigned0 || !uns)
3880 && (TYPE_PRECISION (TREE_TYPE (arg0))
3881 < TYPE_PRECISION (result_type))
3882 && (type = c_common_signed_or_unsigned_type
3883 (unsigned0, TREE_TYPE (arg0)),
3884 int_fits_type_p (arg1, type)))
3888 /* Comparison operations are shortened too but differently.
3889 They identify themselves by setting short_compare = 1. */
3893 /* Don't write &op0, etc., because that would prevent op0
3894 from being kept in a register.
3895 Instead, make copies of the our local variables and
3896 pass the copies by reference, then copy them back afterward. */
3897 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3898 enum tree_code xresultcode = resultcode;
3900 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3902 return cp_convert (boolean_type_node, val);
3903 op0 = xop0, op1 = xop1;
3905 resultcode = xresultcode;
3908 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3909 && warn_sign_compare
3910 /* Do not warn until the template is instantiated; we cannot
3911 bound the ranges of the arguments until that point. */
3912 && !processing_template_decl)
3914 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3915 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3917 int unsignedp0, unsignedp1;
3918 tree primop0 = get_narrower (op0, &unsignedp0);
3919 tree primop1 = get_narrower (op1, &unsignedp1);
3921 /* Check for comparison of different enum types. */
3922 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3923 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3924 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3925 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1))
3926 && (complain & tf_warning))
3928 warning (OPT_Wsign_compare, "comparison between types %q#T and %q#T",
3929 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3932 /* Give warnings for comparisons between signed and unsigned
3933 quantities that may fail. */
3934 /* Do the checking based on the original operand trees, so that
3935 casts will be considered, but default promotions won't be. */
3937 /* Do not warn if the comparison is being done in a signed type,
3938 since the signed type will only be chosen if it can represent
3939 all the values of the unsigned type. */
3940 if (!TYPE_UNSIGNED (result_type))
3942 /* Do not warn if both operands are unsigned. */
3943 else if (op0_signed == op1_signed)
3945 /* Do not warn if the signed quantity is an unsuffixed
3946 integer literal (or some static constant expression
3947 involving such literals or a conditional expression
3948 involving such literals) and it is non-negative. */
3949 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3950 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3952 /* Do not warn if the comparison is an equality operation,
3953 the unsigned quantity is an integral constant and it does
3954 not use the most significant bit of result_type. */
3955 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3956 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3957 && int_fits_type_p (orig_op1, c_common_signed_type
3959 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3960 && int_fits_type_p (orig_op0, c_common_signed_type
3963 else if (complain & tf_warning)
3964 warning (OPT_Wsign_compare,
3965 "comparison between signed and unsigned integer expressions");
3967 /* Warn if two unsigned values are being compared in a size
3968 larger than their original size, and one (and only one) is the
3969 result of a `~' operator. This comparison will always fail.
3971 Also warn if one operand is a constant, and the constant does not
3972 have all bits set that are set in the ~ operand when it is
3975 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3976 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3978 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3979 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3980 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3981 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3983 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3986 HOST_WIDE_INT constant, mask;
3990 if (host_integerp (primop0, 0))
3993 unsignedp = unsignedp1;
3994 constant = tree_low_cst (primop0, 0);
3999 unsignedp = unsignedp0;
4000 constant = tree_low_cst (primop1, 0);
4003 bits = TYPE_PRECISION (TREE_TYPE (primop));
4004 if (bits < TYPE_PRECISION (result_type)
4005 && bits < HOST_BITS_PER_LONG && unsignedp)
4007 mask = (~ (HOST_WIDE_INT) 0) << bits;
4008 if ((mask & constant) != mask
4009 && (complain & tf_warning))
4010 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with constant");
4013 else if (unsignedp0 && unsignedp1
4014 && (TYPE_PRECISION (TREE_TYPE (primop0))
4015 < TYPE_PRECISION (result_type))
4016 && (TYPE_PRECISION (TREE_TYPE (primop1))
4017 < TYPE_PRECISION (result_type))
4018 && (complain & tf_warning))
4019 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with unsigned");
4024 /* Issue warnings about peculiar, but valid, uses of NULL. */
4025 if ((orig_op0 == null_node || orig_op1 == null_node)
4026 /* It's reasonable to use pointer values as operands of &&
4027 and ||, so NULL is no exception. */
4028 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
4029 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
4030 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
4031 && code != EQ_EXPR && code != NE_EXPR)
4032 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
4033 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
4034 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE))
4035 && (complain & tf_warning))
4036 /* Some sort of arithmetic operation involving NULL was
4037 performed. Note that pointer-difference and pointer-addition
4038 have already been handled above, and so we don't end up here in
4040 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
4043 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
4044 Then the expression will be built.
4045 It will be given type FINAL_TYPE if that is nonzero;
4046 otherwise, it will be given type RESULT_TYPE. */
4049 if (TREE_TYPE (op0) != result_type)
4050 op0 = cp_convert_and_check (result_type, op0);
4051 if (TREE_TYPE (op1) != result_type)
4052 op1 = cp_convert_and_check (result_type, op1);
4054 if (op0 == error_mark_node || op1 == error_mark_node)
4055 return error_mark_node;
4058 if (build_type == NULL_TREE)
4059 build_type = result_type;
4061 result = build2 (resultcode, build_type, op0, op1);
4062 result = fold_if_not_in_template (result);
4063 if (final_type != 0)
4064 result = cp_convert (final_type, result);
4066 if (TREE_OVERFLOW_P (result)
4067 && !TREE_OVERFLOW_P (op0)
4068 && !TREE_OVERFLOW_P (op1))
4069 overflow_warning (result);
4074 /* Return a tree for the sum or difference (RESULTCODE says which)
4075 of pointer PTROP and integer INTOP. */
4078 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
4080 tree res_type = TREE_TYPE (ptrop);
4082 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
4083 in certain circumstance (when it's valid to do so). So we need
4084 to make sure it's complete. We don't need to check here, if we
4085 can actually complete it at all, as those checks will be done in
4086 pointer_int_sum() anyway. */
4087 complete_type (TREE_TYPE (res_type));
4089 return pointer_int_sum (resultcode, ptrop,
4090 fold_if_not_in_template (intop));
4093 /* Return a tree for the difference of pointers OP0 and OP1.
4094 The resulting tree has type int. */
4097 pointer_diff (tree op0, tree op1, tree ptrtype)
4100 tree restype = ptrdiff_type_node;
4101 tree target_type = TREE_TYPE (ptrtype);
4103 if (!complete_type_or_else (target_type, NULL_TREE))
4104 return error_mark_node;
4106 if (pedantic || warn_pointer_arith)
4108 if (TREE_CODE (target_type) == VOID_TYPE)
4109 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
4110 if (TREE_CODE (target_type) == FUNCTION_TYPE)
4111 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
4112 if (TREE_CODE (target_type) == METHOD_TYPE)
4113 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
4116 /* First do the subtraction as integers;
4117 then drop through to build the divide operator. */
4119 op0 = cp_build_binary_op (MINUS_EXPR,
4120 cp_convert (restype, op0),
4121 cp_convert (restype, op1),
4122 tf_warning_or_error);
4124 /* This generates an error if op1 is a pointer to an incomplete type. */
4125 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
4126 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
4128 op1 = (TYPE_PTROB_P (ptrtype)
4129 ? size_in_bytes (target_type)
4130 : integer_one_node);
4132 /* Do the division. */
4134 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
4135 return fold_if_not_in_template (result);
4138 /* Construct and perhaps optimize a tree representation
4139 for a unary operation. CODE, a tree_code, specifies the operation
4140 and XARG is the operand. */
4143 build_x_unary_op (enum tree_code code, tree xarg, tsubst_flags_t complain)
4145 tree orig_expr = xarg;
4149 if (processing_template_decl)
4151 if (type_dependent_expression_p (xarg))
4152 return build_min_nt (code, xarg, NULL_TREE);
4154 xarg = build_non_dependent_expr (xarg);
4159 /* [expr.unary.op] says:
4161 The address of an object of incomplete type can be taken.
4163 (And is just the ordinary address operator, not an overloaded
4164 "operator &".) However, if the type is a template
4165 specialization, we must complete the type at this point so that
4166 an overloaded "operator &" will be available if required. */
4167 if (code == ADDR_EXPR
4168 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
4169 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
4170 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
4171 || (TREE_CODE (xarg) == OFFSET_REF)))
4172 /* Don't look for a function. */;
4174 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
4175 /*overloaded_p=*/NULL, complain);
4176 if (!exp && code == ADDR_EXPR)
4178 /* A pointer to member-function can be formed only by saying
4180 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
4181 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
4183 if (TREE_CODE (xarg) != OFFSET_REF
4184 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4186 error ("invalid use of %qE to form a pointer-to-member-function",
4188 if (TREE_CODE (xarg) != OFFSET_REF)
4189 inform (" a qualified-id is required");
4190 return error_mark_node;
4194 error ("parentheses around %qE cannot be used to form a"
4195 " pointer-to-member-function",
4197 PTRMEM_OK_P (xarg) = 1;
4201 if (TREE_CODE (xarg) == OFFSET_REF)
4203 ptrmem = PTRMEM_OK_P (xarg);
4205 if (!ptrmem && !flag_ms_extensions
4206 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4208 /* A single non-static member, make sure we don't allow a
4209 pointer-to-member. */
4210 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4211 TREE_OPERAND (xarg, 0),
4212 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4213 PTRMEM_OK_P (xarg) = ptrmem;
4216 else if (TREE_CODE (xarg) == TARGET_EXPR && (complain & tf_warning))
4217 warning (0, "taking address of temporary");
4218 exp = cp_build_unary_op (ADDR_EXPR, xarg, 0, complain);
4221 if (processing_template_decl && exp != error_mark_node)
4222 exp = build_min_non_dep (code, exp, orig_expr,
4223 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4224 if (TREE_CODE (exp) == ADDR_EXPR)
4225 PTRMEM_OK_P (exp) = ptrmem;
4229 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4230 constants, where a null value is represented by an INTEGER_CST of
4234 cp_truthvalue_conversion (tree expr)
4236 tree type = TREE_TYPE (expr);
4237 if (TYPE_PTRMEM_P (type))
4238 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4240 return c_common_truthvalue_conversion (expr);
4243 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4246 condition_conversion (tree expr)
4249 if (processing_template_decl)
4251 t = perform_implicit_conversion (boolean_type_node, expr,
4252 tf_warning_or_error);
4253 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4257 /* Return an ADDR_EXPR giving the address of T. This function
4258 attempts no optimizations or simplifications; it is a low-level
4262 build_address (tree t)
4266 if (error_operand_p (t) || !cxx_mark_addressable (t))
4267 return error_mark_node;
4269 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4274 /* Return a NOP_EXPR converting EXPR to TYPE. */
4277 build_nop (tree type, tree expr)
4279 if (type == error_mark_node || error_operand_p (expr))
4281 return build1 (NOP_EXPR, type, expr);
4284 /* C++: Must handle pointers to members.
4286 Perhaps type instantiation should be extended to handle conversion
4287 from aggregates to types we don't yet know we want? (Or are those
4288 cases typically errors which should be reported?)
4290 NOCONVERT nonzero suppresses the default promotions
4291 (such as from short to int). */
4294 cp_build_unary_op (enum tree_code code, tree xarg, int noconvert,
4295 tsubst_flags_t complain)
4297 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4300 const char *errstring = NULL;
4302 const char *invalid_op_diag;
4304 if (arg == error_mark_node)
4305 return error_mark_node;
4307 if ((invalid_op_diag
4308 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4313 error (invalid_op_diag);
4314 return error_mark_node;
4319 case UNARY_PLUS_EXPR:
4322 int flags = WANT_ARITH | WANT_ENUM;
4323 /* Unary plus (but not unary minus) is allowed on pointers. */
4324 if (code == UNARY_PLUS_EXPR)
4325 flags |= WANT_POINTER;
4326 arg = build_expr_type_conversion (flags, arg, true);
4328 errstring = (code == NEGATE_EXPR
4329 ? "wrong type argument to unary minus"
4330 : "wrong type argument to unary plus");
4333 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4334 arg = perform_integral_promotions (arg);
4336 /* Make sure the result is not an lvalue: a unary plus or minus
4337 expression is always a rvalue. */
4344 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4348 arg = default_conversion (arg);
4350 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4353 errstring = "wrong type argument to bit-complement";
4354 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4355 arg = perform_integral_promotions (arg);
4359 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4360 errstring = "wrong type argument to abs";
4361 else if (!noconvert)
4362 arg = default_conversion (arg);
4366 /* Conjugating a real value is a no-op, but allow it anyway. */
4367 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4368 errstring = "wrong type argument to conjugation";
4369 else if (!noconvert)
4370 arg = default_conversion (arg);
4373 case TRUTH_NOT_EXPR:
4374 arg = perform_implicit_conversion (boolean_type_node, arg,
4376 val = invert_truthvalue (arg);
4377 if (arg != error_mark_node)
4379 errstring = "in argument to unary !";
4386 if (TREE_CODE (arg) == COMPLEX_CST)
4387 return TREE_REALPART (arg);
4388 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4390 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4391 return fold_if_not_in_template (arg);
4397 if (TREE_CODE (arg) == COMPLEX_CST)
4398 return TREE_IMAGPART (arg);
4399 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4401 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4402 return fold_if_not_in_template (arg);
4405 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4407 case PREINCREMENT_EXPR:
4408 case POSTINCREMENT_EXPR:
4409 case PREDECREMENT_EXPR:
4410 case POSTDECREMENT_EXPR:
4411 /* Handle complex lvalues (when permitted)
4412 by reduction to simpler cases. */
4414 val = unary_complex_lvalue (code, arg);
4418 /* Increment or decrement the real part of the value,
4419 and don't change the imaginary part. */
4420 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4424 arg = stabilize_reference (arg);
4425 real = cp_build_unary_op (REALPART_EXPR, arg, 1, complain);
4426 imag = cp_build_unary_op (IMAGPART_EXPR, arg, 1, complain);
4427 real = cp_build_unary_op (code, real, 1, complain);
4428 if (real == error_mark_node || imag == error_mark_node)
4429 return error_mark_node;
4430 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4434 /* Report invalid types. */
4436 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4439 if (code == PREINCREMENT_EXPR)
4440 errstring ="no pre-increment operator for type";
4441 else if (code == POSTINCREMENT_EXPR)
4442 errstring ="no post-increment operator for type";
4443 else if (code == PREDECREMENT_EXPR)
4444 errstring ="no pre-decrement operator for type";
4446 errstring ="no post-decrement operator for type";
4449 else if (arg == error_mark_node)
4450 return error_mark_node;
4452 /* Report something read-only. */
4454 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4455 || TREE_READONLY (arg))
4457 if (complain & tf_error)
4458 readonly_error (arg, ((code == PREINCREMENT_EXPR
4459 || code == POSTINCREMENT_EXPR)
4460 ? "increment" : "decrement"));
4462 return error_mark_node;
4468 tree result_type = TREE_TYPE (arg);
4470 declared_type = unlowered_expr_type (arg);
4472 arg = get_unwidened (arg, 0);
4473 argtype = TREE_TYPE (arg);
4475 /* ARM $5.2.5 last annotation says this should be forbidden. */
4476 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4478 if (complain & tf_error)
4479 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4480 ? G_("ISO C++ forbids incrementing an enum")
4481 : G_("ISO C++ forbids decrementing an enum"));
4483 return error_mark_node;
4486 /* Compute the increment. */
4488 if (TREE_CODE (argtype) == POINTER_TYPE)
4490 tree type = complete_type (TREE_TYPE (argtype));
4492 if (!COMPLETE_OR_VOID_TYPE_P (type))
4494 if (complain & tf_error)
4495 error (((code == PREINCREMENT_EXPR
4496 || code == POSTINCREMENT_EXPR))
4497 ? G_("cannot increment a pointer to incomplete type %qT")
4498 : G_("cannot decrement a pointer to incomplete type %qT"),
4499 TREE_TYPE (argtype));
4501 return error_mark_node;
4503 else if ((pedantic || warn_pointer_arith)
4504 && !TYPE_PTROB_P (argtype))
4506 if (complain & tf_error)
4507 pedwarn ((code == PREINCREMENT_EXPR
4508 || code == POSTINCREMENT_EXPR)
4509 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4510 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4513 return error_mark_node;
4516 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4519 inc = integer_one_node;
4521 inc = cp_convert (argtype, inc);
4523 /* Complain about anything else that is not a true lvalue. */
4524 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4525 || code == POSTINCREMENT_EXPR)
4526 ? lv_increment : lv_decrement),
4528 return error_mark_node;
4530 /* Forbid using -- on `bool'. */
4531 if (same_type_p (declared_type, boolean_type_node))
4533 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4535 if (complain & tf_error)
4536 error ("invalid use of Boolean expression as operand "
4537 "to %<operator--%>");
4538 return error_mark_node;
4540 val = boolean_increment (code, arg);
4543 val = build2 (code, TREE_TYPE (arg), arg, inc);
4545 TREE_SIDE_EFFECTS (val) = 1;
4546 return cp_convert (result_type, val);
4550 /* Note that this operation never does default_conversion
4551 regardless of NOCONVERT. */
4553 argtype = lvalue_type (arg);
4555 if (TREE_CODE (arg) == OFFSET_REF)
4558 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4560 tree type = build_pointer_type (TREE_TYPE (argtype));
4561 arg = build1 (CONVERT_EXPR, type, arg);
4564 else if (pedantic && DECL_MAIN_P (arg))
4567 if (complain & tf_error)
4568 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4570 return error_mark_node;
4573 /* Let &* cancel out to simplify resulting code. */
4574 if (TREE_CODE (arg) == INDIRECT_REF)
4576 /* We don't need to have `current_class_ptr' wrapped in a
4577 NON_LVALUE_EXPR node. */
4578 if (arg == current_class_ref)
4579 return current_class_ptr;
4581 arg = TREE_OPERAND (arg, 0);
4582 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4584 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4585 arg = build1 (CONVERT_EXPR, type, arg);
4588 /* Don't let this be an lvalue. */
4593 /* Uninstantiated types are all functions. Taking the
4594 address of a function is a no-op, so just return the
4597 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4598 || !IDENTIFIER_OPNAME_P (arg));
4600 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4601 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4603 /* They're trying to take the address of a unique non-static
4604 member function. This is ill-formed (except in MS-land),
4605 but let's try to DTRT.
4606 Note: We only handle unique functions here because we don't
4607 want to complain if there's a static overload; non-unique
4608 cases will be handled by instantiate_type. But we need to
4609 handle this case here to allow casts on the resulting PMF.
4610 We could defer this in non-MS mode, but it's easier to give
4611 a useful error here. */
4613 /* Inside constant member functions, the `this' pointer
4614 contains an extra const qualifier. TYPE_MAIN_VARIANT
4615 is used here to remove this const from the diagnostics
4616 and the created OFFSET_REF. */
4617 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4618 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4621 if (! flag_ms_extensions)
4623 tree name = DECL_NAME (fn);
4624 if (!(complain & tf_error))
4625 return error_mark_node;
4626 else if (current_class_type
4627 && TREE_OPERAND (arg, 0) == current_class_ref)
4628 /* An expression like &memfn. */
4629 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4630 " or parenthesized non-static member function to form"
4631 " a pointer to member function. Say %<&%T::%D%>",
4634 pedwarn ("ISO C++ forbids taking the address of a bound member"
4635 " function to form a pointer to member function."
4639 arg = build_offset_ref (base, fn, /*address_p=*/true);
4643 if (type_unknown_p (arg))
4644 return build1 (ADDR_EXPR, unknown_type_node, arg);
4646 /* Handle complex lvalues (when permitted)
4647 by reduction to simpler cases. */
4648 val = unary_complex_lvalue (code, arg);
4652 switch (TREE_CODE (arg))
4657 case FIX_TRUNC_EXPR:
4658 /* Even if we're not being pedantic, we cannot allow this
4659 extension when we're instantiating in a SFINAE
4661 if (! lvalue_p (arg) && (pedantic || complain == tf_none))
4663 if (complain & tf_error)
4664 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4666 return error_mark_node;
4671 arg = BASELINK_FUNCTIONS (arg);
4675 arg = OVL_CURRENT (arg);
4679 /* Turn a reference to a non-static data member into a
4680 pointer-to-member. */
4685 if (!PTRMEM_OK_P (arg))
4686 return cp_build_unary_op (code, arg, 0, complain);
4688 t = TREE_OPERAND (arg, 1);
4689 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4691 if (complain & tf_error)
4692 error ("cannot create pointer to reference member %qD", t);
4693 return error_mark_node;
4696 type = build_ptrmem_type (context_for_name_lookup (t),
4698 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4706 /* Anything not already handled and not a true memory reference
4708 if (TREE_CODE (argtype) != FUNCTION_TYPE
4709 && TREE_CODE (argtype) != METHOD_TYPE
4710 && TREE_CODE (arg) != OFFSET_REF
4711 && !lvalue_or_else (arg, lv_addressof, complain))
4712 return error_mark_node;
4714 if (argtype != error_mark_node)
4715 argtype = build_pointer_type (argtype);
4717 /* In a template, we are processing a non-dependent expression
4718 so we can just form an ADDR_EXPR with the correct type. */
4719 if (processing_template_decl)
4721 val = build_address (arg);
4722 if (TREE_CODE (arg) == OFFSET_REF)
4723 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4727 if (TREE_CODE (arg) != COMPONENT_REF)
4729 val = build_address (arg);
4730 if (TREE_CODE (arg) == OFFSET_REF)
4731 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4733 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4735 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4737 /* We can only get here with a single static member
4739 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4740 && DECL_STATIC_FUNCTION_P (fn));
4742 val = build_address (fn);
4743 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4744 /* Do not lose object's side effects. */
4745 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4746 TREE_OPERAND (arg, 0), val);
4748 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4750 if (complain & tf_error)
4751 error ("attempt to take address of bit-field structure member %qD",
4752 TREE_OPERAND (arg, 1));
4753 return error_mark_node;
4757 tree object = TREE_OPERAND (arg, 0);
4758 tree field = TREE_OPERAND (arg, 1);
4759 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4760 (TREE_TYPE (object), decl_type_context (field)));
4761 val = build_address (arg);
4764 if (TREE_CODE (argtype) == POINTER_TYPE
4765 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4767 build_ptrmemfunc_type (argtype);
4768 val = build_ptrmemfunc (argtype, val, 0,
4769 /*c_cast_p=*/false);
4781 argtype = TREE_TYPE (arg);
4782 return fold_if_not_in_template (build1 (code, argtype, arg));
4785 if (complain & tf_error)
4786 error ("%s", errstring);
4787 return error_mark_node;
4790 /* Hook for the c-common bits that build a unary op. */
4792 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4794 return cp_build_unary_op (code, xarg, noconvert, tf_warning_or_error);
4797 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4798 for certain kinds of expressions which are not really lvalues
4799 but which we can accept as lvalues.
4801 If ARG is not a kind of expression we can handle, return
4805 unary_complex_lvalue (enum tree_code code, tree arg)
4807 /* Inside a template, making these kinds of adjustments is
4808 pointless; we are only concerned with the type of the
4810 if (processing_template_decl)
4813 /* Handle (a, b) used as an "lvalue". */
4814 if (TREE_CODE (arg) == COMPOUND_EXPR)
4816 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 1), 0,
4817 tf_warning_or_error);
4818 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4819 TREE_OPERAND (arg, 0), real_result);
4822 /* Handle (a ? b : c) used as an "lvalue". */
4823 if (TREE_CODE (arg) == COND_EXPR
4824 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4825 return rationalize_conditional_expr (code, arg, tf_warning_or_error);
4827 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4828 if (TREE_CODE (arg) == MODIFY_EXPR
4829 || TREE_CODE (arg) == PREINCREMENT_EXPR
4830 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4832 tree lvalue = TREE_OPERAND (arg, 0);
4833 if (TREE_SIDE_EFFECTS (lvalue))
4835 lvalue = stabilize_reference (lvalue);
4836 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4837 lvalue, TREE_OPERAND (arg, 1));
4839 return unary_complex_lvalue
4840 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4843 if (code != ADDR_EXPR)
4846 /* Handle (a = b) used as an "lvalue" for `&'. */
4847 if (TREE_CODE (arg) == MODIFY_EXPR
4848 || TREE_CODE (arg) == INIT_EXPR)
4850 tree real_result = cp_build_unary_op (code, TREE_OPERAND (arg, 0), 0,
4851 tf_warning_or_error);
4852 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4854 TREE_NO_WARNING (arg) = 1;
4858 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4859 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4860 || TREE_CODE (arg) == OFFSET_REF)
4863 /* We permit compiler to make function calls returning
4864 objects of aggregate type look like lvalues. */
4868 if (TREE_CODE (targ) == SAVE_EXPR)
4869 targ = TREE_OPERAND (targ, 0);
4871 if (TREE_CODE (targ) == CALL_EXPR && MAYBE_CLASS_TYPE_P (TREE_TYPE (targ)))
4873 if (TREE_CODE (arg) == SAVE_EXPR)
4876 targ = build_cplus_new (TREE_TYPE (arg), arg);
4877 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4880 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4881 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4882 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4885 /* Don't let anything else be handled specially. */
4889 /* Mark EXP saying that we need to be able to take the
4890 address of it; it should not be allocated in a register.
4891 Value is true if successful.
4893 C++: we do not allow `current_class_ptr' to be addressable. */
4896 cxx_mark_addressable (tree exp)
4901 switch (TREE_CODE (x))
4908 x = TREE_OPERAND (x, 0);
4912 if (x == current_class_ptr)
4914 error ("cannot take the address of %<this%>, which is an rvalue expression");
4915 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4921 /* Caller should not be trying to mark initialized
4922 constant fields addressable. */
4923 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4924 || DECL_IN_AGGR_P (x) == 0
4926 || DECL_EXTERNAL (x));
4931 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4932 && !DECL_ARTIFICIAL (x))
4934 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4937 ("address of explicit register variable %qD requested", x);
4940 else if (extra_warnings)
4942 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4944 TREE_ADDRESSABLE (x) = 1;
4948 TREE_ADDRESSABLE (x) = 1;
4952 TREE_ADDRESSABLE (x) = 1;
4956 TREE_ADDRESSABLE (x) = 1;
4957 cxx_mark_addressable (TREE_OPERAND (x, 0));
4965 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4968 build_x_conditional_expr (tree ifexp, tree op1, tree op2,
4969 tsubst_flags_t complain)
4971 tree orig_ifexp = ifexp;
4972 tree orig_op1 = op1;
4973 tree orig_op2 = op2;
4976 if (processing_template_decl)
4978 /* The standard says that the expression is type-dependent if
4979 IFEXP is type-dependent, even though the eventual type of the
4980 expression doesn't dependent on IFEXP. */
4981 if (type_dependent_expression_p (ifexp)
4982 /* As a GNU extension, the middle operand may be omitted. */
4983 || (op1 && type_dependent_expression_p (op1))
4984 || type_dependent_expression_p (op2))
4985 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4986 ifexp = build_non_dependent_expr (ifexp);
4988 op1 = build_non_dependent_expr (op1);
4989 op2 = build_non_dependent_expr (op2);
4992 expr = build_conditional_expr (ifexp, op1, op2, complain);
4993 if (processing_template_decl && expr != error_mark_node)
4994 return build_min_non_dep (COND_EXPR, expr,
4995 orig_ifexp, orig_op1, orig_op2);
4999 /* Given a list of expressions, return a compound expression
5000 that performs them all and returns the value of the last of them. */
5002 tree build_x_compound_expr_from_list (tree list, const char *msg)
5004 tree expr = TREE_VALUE (list);
5006 if (TREE_CHAIN (list))
5009 pedwarn ("%s expression list treated as compound expression", msg);
5011 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
5012 expr = build_x_compound_expr (expr, TREE_VALUE (list),
5013 tf_warning_or_error);
5019 /* Handle overloading of the ',' operator when needed. */
5022 build_x_compound_expr (tree op1, tree op2, tsubst_flags_t complain)
5025 tree orig_op1 = op1;
5026 tree orig_op2 = op2;
5028 if (processing_template_decl)
5030 if (type_dependent_expression_p (op1)
5031 || type_dependent_expression_p (op2))
5032 return build_min_nt (COMPOUND_EXPR, op1, op2);
5033 op1 = build_non_dependent_expr (op1);
5034 op2 = build_non_dependent_expr (op2);
5037 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
5038 /*overloaded_p=*/NULL, complain);
5040 result = cp_build_compound_expr (op1, op2, complain);
5042 if (processing_template_decl && result != error_mark_node)
5043 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
5048 /* Like cp_build_compound_expr, but for the c-common bits. */
5051 build_compound_expr (tree lhs, tree rhs)
5053 return cp_build_compound_expr (lhs, rhs, tf_warning_or_error);
5056 /* Build a compound expression. */
5059 cp_build_compound_expr (tree lhs, tree rhs, tsubst_flags_t complain)
5061 lhs = convert_to_void (lhs, "left-hand operand of comma", complain);
5063 if (lhs == error_mark_node || rhs == error_mark_node)
5064 return error_mark_node;
5066 if (TREE_CODE (rhs) == TARGET_EXPR)
5068 /* If the rhs is a TARGET_EXPR, then build the compound
5069 expression inside the target_expr's initializer. This
5070 helps the compiler to eliminate unnecessary temporaries. */
5071 tree init = TREE_OPERAND (rhs, 1);
5073 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
5074 TREE_OPERAND (rhs, 1) = init;
5079 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
5082 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
5083 casts away constness. CAST gives the type of cast. */
5086 check_for_casting_away_constness (tree src_type, tree dest_type,
5087 enum tree_code cast)
5089 /* C-style casts are allowed to cast away constness. With
5090 WARN_CAST_QUAL, we still want to issue a warning. */
5091 if (cast == CAST_EXPR && !warn_cast_qual)
5094 if (casts_away_constness (src_type, dest_type))
5098 warning (OPT_Wcast_qual,
5099 "cast from type %qT to type %qT casts away constness",
5100 src_type, dest_type);
5103 case STATIC_CAST_EXPR:
5104 error ("static_cast from type %qT to type %qT casts away constness",
5105 src_type, dest_type);
5108 case REINTERPRET_CAST_EXPR:
5109 error ("reinterpret_cast from type %qT to type %qT casts away constness",
5110 src_type, dest_type);
5117 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
5118 (another pointer-to-member type in the same hierarchy) and return
5119 the converted expression. If ALLOW_INVERSE_P is permitted, a
5120 pointer-to-derived may be converted to pointer-to-base; otherwise,
5121 only the other direction is permitted. If C_CAST_P is true, this
5122 conversion is taking place as part of a C-style cast. */
5125 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
5128 if (TYPE_PTRMEM_P (type))
5132 if (TREE_CODE (expr) == PTRMEM_CST)
5133 expr = cplus_expand_constant (expr);
5134 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
5135 TYPE_PTRMEM_CLASS_TYPE (type),
5138 if (!integer_zerop (delta))
5140 tree cond, op1, op2;
5142 cond = cp_build_binary_op (EQ_EXPR,
5144 build_int_cst (TREE_TYPE (expr), -1),
5145 tf_warning_or_error);
5146 op1 = build_nop (ptrdiff_type_node, expr);
5147 op2 = cp_build_binary_op (PLUS_EXPR, op1, delta,
5148 tf_warning_or_error);
5150 expr = fold_build3 (COND_EXPR, ptrdiff_type_node, cond, op1, op2);
5154 return build_nop (type, expr);
5157 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
5158 allow_inverse_p, c_cast_p);
5161 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
5162 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
5163 Otherwise, return EXPR unchanged. */
5166 ignore_overflows (tree expr, tree orig)
5168 if (TREE_CODE (expr) == INTEGER_CST
5169 && CONSTANT_CLASS_P (orig)
5170 && TREE_CODE (orig) != STRING_CST
5171 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
5173 if (!TREE_OVERFLOW (orig))
5174 /* Ensure constant sharing. */
5175 expr = build_int_cst_wide (TREE_TYPE (expr),
5176 TREE_INT_CST_LOW (expr),
5177 TREE_INT_CST_HIGH (expr));
5180 /* Avoid clobbering a shared constant. */
5181 expr = copy_node (expr);
5182 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
5188 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
5189 this static_cast is being attempted as one of the possible casts
5190 allowed by a C-style cast. (In that case, accessibility of base
5191 classes is not considered, and it is OK to cast away
5192 constness.) Return the result of the cast. *VALID_P is set to
5193 indicate whether or not the cast was valid. */
5196 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
5197 bool *valid_p, tsubst_flags_t complain)
5203 /* Assume the cast is valid. */
5206 intype = TREE_TYPE (expr);
5208 /* Save casted types in the function's used types hash table. */
5209 used_types_insert (type);
5211 /* [expr.static.cast]
5213 An lvalue of type "cv1 B", where B is a class type, can be cast
5214 to type "reference to cv2 D", where D is a class derived (clause
5215 _class.derived_) from B, if a valid standard conversion from
5216 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
5217 same cv-qualification as, or greater cv-qualification than, cv1,
5218 and B is not a virtual base class of D. */
5219 /* We check this case before checking the validity of "TYPE t =
5220 EXPR;" below because for this case:
5223 struct D : public B { D(const B&); };
5225 void f() { static_cast<const D&>(b); }
5227 we want to avoid constructing a new D. The standard is not
5228 completely clear about this issue, but our interpretation is
5229 consistent with other compilers. */
5230 if (TREE_CODE (type) == REFERENCE_TYPE
5231 && CLASS_TYPE_P (TREE_TYPE (type))
5232 && CLASS_TYPE_P (intype)
5233 && real_lvalue_p (expr)
5234 && DERIVED_FROM_P (intype, TREE_TYPE (type))
5235 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
5236 build_pointer_type (TYPE_MAIN_VARIANT
5237 (TREE_TYPE (type))))
5239 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5243 /* There is a standard conversion from "D*" to "B*" even if "B"
5244 is ambiguous or inaccessible. If this is really a
5245 static_cast, then we check both for inaccessibility and
5246 ambiguity. However, if this is a static_cast being performed
5247 because the user wrote a C-style cast, then accessibility is
5249 base = lookup_base (TREE_TYPE (type), intype,
5250 c_cast_p ? ba_unique : ba_check,
5253 /* Convert from "B*" to "D*". This function will check that "B"
5254 is not a virtual base of "D". */
5255 expr = build_base_path (MINUS_EXPR, build_address (expr),
5256 base, /*nonnull=*/false);
5257 /* Convert the pointer to a reference -- but then remember that
5258 there are no expressions with reference type in C++. */
5259 return convert_from_reference (build_nop (type, expr));
5264 /* [expr.static.cast]
5266 An expression e can be explicitly converted to a type T using a
5267 static_cast of the form static_cast<T>(e) if the declaration T
5268 t(e);" is well-formed, for some invented temporary variable
5270 result = perform_direct_initialization_if_possible (type, expr,
5271 c_cast_p, complain);
5274 result = convert_from_reference (result);
5276 /* Ignore any integer overflow caused by the cast. */
5277 result = ignore_overflows (result, orig);
5279 /* [expr.static.cast]
5281 If T is a reference type, the result is an lvalue; otherwise,
5282 the result is an rvalue. */
5283 if (TREE_CODE (type) != REFERENCE_TYPE)
5284 result = rvalue (result);
5288 /* [expr.static.cast]
5290 Any expression can be explicitly converted to type cv void. */
5291 if (TREE_CODE (type) == VOID_TYPE)
5292 return convert_to_void (expr, /*implicit=*/NULL, complain);
5294 /* [expr.static.cast]
5296 The inverse of any standard conversion sequence (clause _conv_),
5297 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5298 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5299 (_conv.bool_) conversions, can be performed explicitly using
5300 static_cast subject to the restriction that the explicit
5301 conversion does not cast away constness (_expr.const.cast_), and
5302 the following additional rules for specific cases: */
5303 /* For reference, the conversions not excluded are: integral
5304 promotions, floating point promotion, integral conversions,
5305 floating point conversions, floating-integral conversions,
5306 pointer conversions, and pointer to member conversions. */
5309 A value of integral _or enumeration_ type can be explicitly
5310 converted to an enumeration type. */
5311 /* The effect of all that is that any conversion between any two
5312 types which are integral, floating, or enumeration types can be
5314 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5315 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5317 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5319 /* Ignore any integer overflow caused by the cast. */
5320 expr = ignore_overflows (expr, orig);
5324 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5325 && CLASS_TYPE_P (TREE_TYPE (type))
5326 && CLASS_TYPE_P (TREE_TYPE (intype))
5327 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5328 (TREE_TYPE (intype))),
5329 build_pointer_type (TYPE_MAIN_VARIANT
5330 (TREE_TYPE (type)))))
5335 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5336 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5337 c_cast_p ? ba_unique : ba_check,
5339 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5342 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5343 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5350 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5351 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5353 if (TYPE_PTRMEM_P (type))
5355 t1 = (build_ptrmem_type
5357 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5358 t2 = (build_ptrmem_type
5360 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5367 if (can_convert (t1, t2) || can_convert (t2, t1))
5370 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5371 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5376 /* [expr.static.cast]
5378 An rvalue of type "pointer to cv void" can be explicitly
5379 converted to a pointer to object type. A value of type pointer
5380 to object converted to "pointer to cv void" and back to the
5381 original pointer type will have its original value. */
5382 if (TREE_CODE (intype) == POINTER_TYPE
5383 && VOID_TYPE_P (TREE_TYPE (intype))
5384 && TYPE_PTROB_P (type))
5387 check_for_casting_away_constness (intype, type, STATIC_CAST_EXPR);
5388 return build_nop (type, expr);
5392 return error_mark_node;
5395 /* Return an expression representing static_cast<TYPE>(EXPR). */
5398 build_static_cast (tree type, tree expr, tsubst_flags_t complain)
5403 if (type == error_mark_node || expr == error_mark_node)
5404 return error_mark_node;
5406 if (processing_template_decl)
5408 expr = build_min (STATIC_CAST_EXPR, type, expr);
5409 /* We don't know if it will or will not have side effects. */
5410 TREE_SIDE_EFFECTS (expr) = 1;
5411 return convert_from_reference (expr);
5414 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5415 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5416 if (TREE_CODE (type) != REFERENCE_TYPE
5417 && TREE_CODE (expr) == NOP_EXPR
5418 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5419 expr = TREE_OPERAND (expr, 0);
5421 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p,
5426 if (complain & tf_error)
5427 error ("invalid static_cast from type %qT to type %qT",
5428 TREE_TYPE (expr), type);
5429 return error_mark_node;
5432 /* EXPR is an expression with member function or pointer-to-member
5433 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5434 not permitted by ISO C++, but we accept it in some modes. If we
5435 are not in one of those modes, issue a diagnostic. Return the
5436 converted expression. */
5439 convert_member_func_to_ptr (tree type, tree expr)
5444 intype = TREE_TYPE (expr);
5445 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5446 || TREE_CODE (intype) == METHOD_TYPE);
5448 if (pedantic || warn_pmf2ptr)
5449 pedwarn ("converting from %qT to %qT", intype, type);
5451 if (TREE_CODE (intype) == METHOD_TYPE)
5452 expr = build_addr_func (expr);
5453 else if (TREE_CODE (expr) == PTRMEM_CST)
5454 expr = build_address (PTRMEM_CST_MEMBER (expr));
5457 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5458 decl = build_address (decl);
5459 expr = get_member_function_from_ptrfunc (&decl, expr);
5462 return build_nop (type, expr);
5465 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5466 If C_CAST_P is true, this reinterpret cast is being done as part of
5467 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5468 indicate whether or not reinterpret_cast was valid. */
5471 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5472 bool *valid_p, tsubst_flags_t complain)
5476 /* Assume the cast is invalid. */
5480 if (type == error_mark_node || error_operand_p (expr))
5481 return error_mark_node;
5483 intype = TREE_TYPE (expr);
5485 /* Save casted types in the function's used types hash table. */
5486 used_types_insert (type);
5488 /* [expr.reinterpret.cast]
5489 An lvalue expression of type T1 can be cast to the type
5490 "reference to T2" if an expression of type "pointer to T1" can be
5491 explicitly converted to the type "pointer to T2" using a
5492 reinterpret_cast. */
5493 if (TREE_CODE (type) == REFERENCE_TYPE)
5495 if (! real_lvalue_p (expr))
5497 if (complain & tf_error)
5498 error ("invalid cast of an rvalue expression of type "
5501 return error_mark_node;
5504 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5505 "B" are related class types; the reinterpret_cast does not
5506 adjust the pointer. */
5507 if (TYPE_PTR_P (intype)
5508 && (complain & tf_warning)
5509 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5510 COMPARE_BASE | COMPARE_DERIVED)))
5511 warning (0, "casting %qT to %qT does not dereference pointer",
5514 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, complain);
5515 if (expr != error_mark_node)
5516 expr = build_reinterpret_cast_1
5517 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5519 if (expr != error_mark_node)
5520 expr = cp_build_indirect_ref (expr, 0, complain);
5524 /* As a G++ extension, we consider conversions from member
5525 functions, and pointers to member functions to
5526 pointer-to-function and pointer-to-void types. If
5527 -Wno-pmf-conversions has not been specified,
5528 convert_member_func_to_ptr will issue an error message. */
5529 if ((TYPE_PTRMEMFUNC_P (intype)
5530 || TREE_CODE (intype) == METHOD_TYPE)
5531 && TYPE_PTR_P (type)
5532 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5533 || VOID_TYPE_P (TREE_TYPE (type))))
5534 return convert_member_func_to_ptr (type, expr);
5536 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5537 array-to-pointer, and function-to-pointer conversions are
5539 expr = decay_conversion (expr);
5541 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5542 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5543 if (TREE_CODE (expr) == NOP_EXPR
5544 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5545 expr = TREE_OPERAND (expr, 0);
5547 if (error_operand_p (expr))
5548 return error_mark_node;
5550 intype = TREE_TYPE (expr);
5552 /* [expr.reinterpret.cast]
5553 A pointer can be converted to any integral type large enough to
5555 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5557 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5559 if (complain & tf_error)
5560 pedwarn ("cast from %qT to %qT loses precision",
5563 return error_mark_node;
5566 /* [expr.reinterpret.cast]
5567 A value of integral or enumeration type can be explicitly
5568 converted to a pointer. */
5569 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5572 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5573 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5574 return fold_if_not_in_template (build_nop (type, expr));
5575 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5576 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5581 check_for_casting_away_constness (intype, type, REINTERPRET_CAST_EXPR);
5582 /* Warn about possible alignment problems. */
5583 if (STRICT_ALIGNMENT && warn_cast_align
5584 && (complain & tf_warning)
5585 && !VOID_TYPE_P (type)
5586 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5587 && COMPLETE_TYPE_P (TREE_TYPE (type))
5588 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5589 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5590 warning (OPT_Wcast_align, "cast from %qT to %qT "
5591 "increases required alignment of target type", intype, type);
5593 /* We need to strip nops here, because the front end likes to
5594 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5596 if (warn_strict_aliasing <= 2)
5597 strict_aliasing_warning (intype, type, sexpr);
5599 return fold_if_not_in_template (build_nop (type, expr));
5601 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5602 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5604 if (pedantic && (complain & tf_warning))
5605 /* Only issue a warning, as we have always supported this
5606 where possible, and it is necessary in some cases. DR 195
5607 addresses this issue, but as of 2004/10/26 is still in
5609 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5610 return fold_if_not_in_template (build_nop (type, expr));
5612 else if (TREE_CODE (type) == VECTOR_TYPE)
5613 return fold_if_not_in_template (convert_to_vector (type, expr));
5614 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5615 return fold_if_not_in_template (convert_to_integer (type, expr));
5620 if (complain & tf_error)
5621 error ("invalid cast from type %qT to type %qT", intype, type);
5622 return error_mark_node;
5625 return cp_convert (type, expr);
5629 build_reinterpret_cast (tree type, tree expr, tsubst_flags_t complain)
5631 if (type == error_mark_node || expr == error_mark_node)
5632 return error_mark_node;
5634 if (processing_template_decl)
5636 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5638 if (!TREE_SIDE_EFFECTS (t)
5639 && type_dependent_expression_p (expr))
5640 /* There might turn out to be side effects inside expr. */
5641 TREE_SIDE_EFFECTS (t) = 1;
5642 return convert_from_reference (t);
5645 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5646 /*valid_p=*/NULL, complain);
5649 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5650 return an appropriate expression. Otherwise, return
5651 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5652 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5653 performing a C-style cast, its value upon return will indicate
5654 whether or not the conversion succeeded. */
5657 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5661 tree reference_type;
5663 /* Callers are responsible for handling error_mark_node as a
5664 destination type. */
5665 gcc_assert (dst_type != error_mark_node);
5666 /* In a template, callers should be building syntactic
5667 representations of casts, not using this machinery. */
5668 gcc_assert (!processing_template_decl);
5670 /* Assume the conversion is invalid. */
5674 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5677 error ("invalid use of const_cast with type %qT, "
5678 "which is not a pointer, "
5679 "reference, nor a pointer-to-data-member type", dst_type);
5680 return error_mark_node;
5683 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5686 error ("invalid use of const_cast with type %qT, which is a pointer "
5687 "or reference to a function type", dst_type);
5688 return error_mark_node;
5691 /* Save casted types in the function's used types hash table. */
5692 used_types_insert (dst_type);
5694 src_type = TREE_TYPE (expr);
5695 /* Expressions do not really have reference types. */
5696 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5697 src_type = TREE_TYPE (src_type);
5699 /* [expr.const.cast]
5701 An lvalue of type T1 can be explicitly converted to an lvalue of
5702 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5703 types) if a pointer to T1 can be explicitly converted to the type
5704 pointer to T2 using a const_cast. */
5705 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5707 reference_type = dst_type;
5708 if (! real_lvalue_p (expr))
5711 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5712 src_type, dst_type);
5713 return error_mark_node;
5715 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5716 src_type = build_pointer_type (src_type);
5720 reference_type = NULL_TREE;
5721 /* If the destination type is not a reference type, the
5722 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5723 conversions are performed. */
5724 src_type = type_decays_to (src_type);
5725 if (src_type == error_mark_node)
5726 return error_mark_node;
5729 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5730 && comp_ptr_ttypes_const (dst_type, src_type))
5735 /* This cast is actually a C-style cast. Issue a warning if
5736 the user is making a potentially unsafe cast. */
5737 check_for_casting_away_constness (src_type, dst_type, CAST_EXPR);
5741 expr = cp_build_unary_op (ADDR_EXPR, expr, 0,
5742 complain? tf_warning_or_error : tf_none);
5743 expr = build_nop (reference_type, expr);
5744 return convert_from_reference (expr);
5748 expr = decay_conversion (expr);
5749 /* build_c_cast puts on a NOP_EXPR to make the result not an
5750 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5751 non-lvalue context. */
5752 if (TREE_CODE (expr) == NOP_EXPR
5753 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5754 expr = TREE_OPERAND (expr, 0);
5755 return build_nop (dst_type, expr);
5760 error ("invalid const_cast from type %qT to type %qT",
5761 src_type, dst_type);
5762 return error_mark_node;
5766 build_const_cast (tree type, tree expr, tsubst_flags_t complain)
5768 if (type == error_mark_node || error_operand_p (expr))
5769 return error_mark_node;
5771 if (processing_template_decl)
5773 tree t = build_min (CONST_CAST_EXPR, type, expr);
5775 if (!TREE_SIDE_EFFECTS (t)
5776 && type_dependent_expression_p (expr))
5777 /* There might turn out to be side effects inside expr. */
5778 TREE_SIDE_EFFECTS (t) = 1;
5779 return convert_from_reference (t);
5782 return build_const_cast_1 (type, expr, complain & tf_error,
5786 /* Like cp_build_c_cast, but for the c-common bits. */
5789 build_c_cast (tree type, tree expr)
5791 return cp_build_c_cast (type, expr, tf_warning_or_error);
5794 /* Build an expression representing an explicit C-style cast to type
5795 TYPE of expression EXPR. */
5798 cp_build_c_cast (tree type, tree expr, tsubst_flags_t complain)
5804 if (type == error_mark_node || error_operand_p (expr))
5805 return error_mark_node;
5807 if (processing_template_decl)
5809 tree t = build_min (CAST_EXPR, type,
5810 tree_cons (NULL_TREE, value, NULL_TREE));
5811 /* We don't know if it will or will not have side effects. */
5812 TREE_SIDE_EFFECTS (t) = 1;
5813 return convert_from_reference (t);
5816 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5817 'Class') should always be retained, because this information aids
5818 in method lookup. */
5819 if (objc_is_object_ptr (type)
5820 && objc_is_object_ptr (TREE_TYPE (expr)))
5821 return build_nop (type, expr);
5823 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5824 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5825 if (TREE_CODE (type) != REFERENCE_TYPE
5826 && TREE_CODE (value) == NOP_EXPR
5827 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5828 value = TREE_OPERAND (value, 0);
5830 if (TREE_CODE (type) == ARRAY_TYPE)
5832 /* Allow casting from T1* to T2[] because Cfront allows it.
5833 NIHCL uses it. It is not valid ISO C++ however. */
5834 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5836 if (complain & tf_error)
5837 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5839 return error_mark_node;
5840 type = build_pointer_type (TREE_TYPE (type));
5844 if (complain & tf_error)
5845 error ("ISO C++ forbids casting to an array type %qT", type);
5846 return error_mark_node;
5850 if (TREE_CODE (type) == FUNCTION_TYPE
5851 || TREE_CODE (type) == METHOD_TYPE)
5853 if (complain & tf_error)
5854 error ("invalid cast to function type %qT", type);
5855 return error_mark_node;
5858 /* A C-style cast can be a const_cast. */
5859 result = build_const_cast_1 (type, value, /*complain=*/false,
5864 /* Or a static cast. */
5865 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5866 &valid_p, complain);
5867 /* Or a reinterpret_cast. */
5869 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5870 &valid_p, complain);
5871 /* The static_cast or reinterpret_cast may be followed by a
5874 /* A valid cast may result in errors if, for example, a
5875 conversion to am ambiguous base class is required. */
5876 && !error_operand_p (result))
5880 /* Non-class rvalues always have cv-unqualified type. */
5881 if (!CLASS_TYPE_P (type))
5882 type = TYPE_MAIN_VARIANT (type);
5883 result_type = TREE_TYPE (result);
5884 if (!CLASS_TYPE_P (result_type))
5885 result_type = TYPE_MAIN_VARIANT (result_type);
5886 /* If the type of RESULT does not match TYPE, perform a
5887 const_cast to make it match. If the static_cast or
5888 reinterpret_cast succeeded, we will differ by at most
5889 cv-qualification, so the follow-on const_cast is guaranteed
5891 if (!same_type_p (non_reference (type), non_reference (result_type)))
5893 result = build_const_cast_1 (type, result, false, &valid_p);
5894 gcc_assert (valid_p);
5899 return error_mark_node;
5902 /* For use from the C common bits. */
5904 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5906 return cp_build_modify_expr (lhs, modifycode, rhs, tf_warning_or_error);
5909 /* Build an assignment expression of lvalue LHS from value RHS.
5910 MODIFYCODE is the code for a binary operator that we use
5911 to combine the old value of LHS with RHS to get the new value.
5912 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5914 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5917 cp_build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
5918 tsubst_flags_t complain)
5922 tree lhstype = TREE_TYPE (lhs);
5923 tree olhstype = lhstype;
5924 tree olhs = NULL_TREE;
5925 bool plain_assign = (modifycode == NOP_EXPR);
5927 /* Avoid duplicate error messages from operands that had errors. */
5928 if (error_operand_p (lhs) || error_operand_p (rhs))
5929 return error_mark_node;
5931 /* Handle control structure constructs used as "lvalues". */
5932 switch (TREE_CODE (lhs))
5934 /* Handle --foo = 5; as these are valid constructs in C++. */
5935 case PREDECREMENT_EXPR:
5936 case PREINCREMENT_EXPR:
5937 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5938 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5939 stabilize_reference (TREE_OPERAND (lhs, 0)),
5940 TREE_OPERAND (lhs, 1));
5941 return build2 (COMPOUND_EXPR, lhstype,
5943 cp_build_modify_expr (TREE_OPERAND (lhs, 0),
5944 modifycode, rhs, complain));
5946 /* Handle (a, b) used as an "lvalue". */
5948 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 1),
5949 modifycode, rhs, complain);
5950 if (newrhs == error_mark_node)
5951 return error_mark_node;
5952 return build2 (COMPOUND_EXPR, lhstype,
5953 TREE_OPERAND (lhs, 0), newrhs);
5956 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5957 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5958 stabilize_reference (TREE_OPERAND (lhs, 0)),
5959 TREE_OPERAND (lhs, 1));
5960 newrhs = cp_build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs,
5962 if (newrhs == error_mark_node)
5963 return error_mark_node;
5964 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5968 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5969 when neither operand has side-effects. */
5970 if (!lvalue_or_else (lhs, lv_assign, complain))
5971 return error_mark_node;
5973 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5974 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5976 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5977 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5979 TREE_OPERAND (lhs, 0),
5980 TREE_OPERAND (lhs, 1)),
5981 TREE_OPERAND (lhs, 0),
5982 TREE_OPERAND (lhs, 1));
5985 /* Handle (a ? b : c) used as an "lvalue". */
5988 /* Produce (a ? (b = rhs) : (c = rhs))
5989 except that the RHS goes through a save-expr
5990 so the code to compute it is only emitted once. */
5992 tree preeval = NULL_TREE;
5994 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5996 if (complain & tf_error)
5997 error ("void value not ignored as it ought to be");
5998 return error_mark_node;
6001 rhs = stabilize_expr (rhs, &preeval);
6003 /* Check this here to avoid odd errors when trying to convert
6004 a throw to the type of the COND_EXPR. */
6005 if (!lvalue_or_else (lhs, lv_assign, complain))
6006 return error_mark_node;
6008 cond = build_conditional_expr
6009 (TREE_OPERAND (lhs, 0),
6010 cp_build_modify_expr (TREE_OPERAND (lhs, 1),
6011 modifycode, rhs, complain),
6012 cp_build_modify_expr (TREE_OPERAND (lhs, 2),
6013 modifycode, rhs, complain),
6016 if (cond == error_mark_node)
6018 /* Make sure the code to compute the rhs comes out
6019 before the split. */
6021 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
6029 if (modifycode == INIT_EXPR)
6031 if (TREE_CODE (rhs) == CONSTRUCTOR)
6033 if (! same_type_p (TREE_TYPE (rhs), lhstype))
6034 /* Call convert to generate an error; see PR 11063. */
6035 rhs = convert (lhstype, rhs);
6036 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
6037 TREE_SIDE_EFFECTS (result) = 1;
6040 else if (! MAYBE_CLASS_TYPE_P (lhstype))
6041 /* Do the default thing. */;
6044 result = build_special_member_call (lhs, complete_ctor_identifier,
6045 build_tree_list (NULL_TREE, rhs),
6046 lhstype, LOOKUP_NORMAL,
6048 if (result == NULL_TREE)
6049 return error_mark_node;
6055 lhs = require_complete_type (lhs);
6056 if (lhs == error_mark_node)
6057 return error_mark_node;
6059 if (modifycode == NOP_EXPR)
6061 /* `operator=' is not an inheritable operator. */
6062 if (! MAYBE_CLASS_TYPE_P (lhstype))
6063 /* Do the default thing. */;
6066 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
6067 lhs, rhs, make_node (NOP_EXPR),
6068 /*overloaded_p=*/NULL,
6070 if (result == NULL_TREE)
6071 return error_mark_node;
6078 /* A binary op has been requested. Combine the old LHS
6079 value with the RHS producing the value we should actually
6080 store into the LHS. */
6081 gcc_assert (!((TREE_CODE (lhstype) == REFERENCE_TYPE
6082 && MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype)))
6083 || MAYBE_CLASS_TYPE_P (lhstype)));
6085 lhs = stabilize_reference (lhs);
6086 newrhs = cp_build_binary_op (modifycode, lhs, rhs,
6088 if (newrhs == error_mark_node)
6090 if (complain & tf_error)
6091 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
6092 TREE_TYPE (lhs), TREE_TYPE (rhs));
6093 return error_mark_node;
6096 /* Now it looks like a plain assignment. */
6097 modifycode = NOP_EXPR;
6099 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
6100 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
6103 /* The left-hand side must be an lvalue. */
6104 if (!lvalue_or_else (lhs, lv_assign, complain))
6105 return error_mark_node;
6107 /* Warn about modifying something that is `const'. Don't warn if
6108 this is initialization. */
6109 if (modifycode != INIT_EXPR
6110 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
6111 /* Functions are not modifiable, even though they are
6113 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
6114 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
6115 /* If it's an aggregate and any field is const, then it is
6116 effectively const. */
6117 || (CLASS_TYPE_P (lhstype)
6118 && C_TYPE_FIELDS_READONLY (lhstype))))
6120 if (complain & tf_error)
6121 readonly_error (lhs, "assignment");
6123 return error_mark_node;
6126 /* If storing into a structure or union member, it has probably been
6127 given type `int'. Compute the type that would go with the actual
6128 amount of storage the member occupies. */
6130 if (TREE_CODE (lhs) == COMPONENT_REF
6131 && (TREE_CODE (lhstype) == INTEGER_TYPE
6132 || TREE_CODE (lhstype) == REAL_TYPE
6133 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
6135 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
6137 /* If storing in a field that is in actuality a short or narrower
6138 than one, we must store in the field in its actual type. */
6140 if (lhstype != TREE_TYPE (lhs))
6142 /* Avoid warnings converting integral types back into enums for
6144 if (TREE_CODE (lhstype) == INTEGER_TYPE
6145 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
6147 if (TREE_SIDE_EFFECTS (lhs))
6148 lhs = stabilize_reference (lhs);
6151 lhs = copy_node (lhs);
6152 TREE_TYPE (lhs) = lhstype;
6156 /* Convert new value to destination type. */
6158 if (TREE_CODE (lhstype) == ARRAY_TYPE)
6162 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
6163 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
6165 if (complain & tf_error)
6166 error ("incompatible types in assignment of %qT to %qT",
6167 TREE_TYPE (rhs), lhstype);
6168 return error_mark_node;
6171 /* Allow array assignment in compiler-generated code. */
6172 if (! DECL_ARTIFICIAL (current_function_decl))
6174 /* This routine is used for both initialization and assignment.
6175 Make sure the diagnostic message differentiates the context. */
6176 if (complain & tf_error)
6178 if (modifycode == INIT_EXPR)
6179 error ("array used as initializer");
6181 error ("invalid array assignment");
6183 return error_mark_node;
6186 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
6187 ? 1 + (modifycode != INIT_EXPR): 0;
6188 return build_vec_init (lhs, NULL_TREE, newrhs,
6189 /*explicit_default_init_p=*/false,
6190 from_array, complain);
6193 if (modifycode == INIT_EXPR)
6194 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
6195 "initialization", NULL_TREE, 0,
6199 /* Avoid warnings on enum bit fields. */
6200 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
6201 && TREE_CODE (lhstype) == INTEGER_TYPE)
6203 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
6204 NULL_TREE, 0, complain);
6205 newrhs = convert_force (lhstype, newrhs, 0);
6208 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
6209 NULL_TREE, 0, complain);
6210 if (TREE_CODE (newrhs) == CALL_EXPR
6211 && TYPE_NEEDS_CONSTRUCTING (lhstype))
6212 newrhs = build_cplus_new (lhstype, newrhs);
6214 /* Can't initialize directly from a TARGET_EXPR, since that would
6215 cause the lhs to be constructed twice, and possibly result in
6216 accidental self-initialization. So we force the TARGET_EXPR to be
6217 expanded without a target. */
6218 if (TREE_CODE (newrhs) == TARGET_EXPR)
6219 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
6220 TREE_OPERAND (newrhs, 0));
6223 if (newrhs == error_mark_node)
6224 return error_mark_node;
6226 if (c_dialect_objc () && flag_objc_gc)
6228 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
6234 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
6235 lhstype, lhs, newrhs);
6237 TREE_SIDE_EFFECTS (result) = 1;
6239 TREE_NO_WARNING (result) = 1;
6241 /* If we got the LHS in a different type for storing in,
6242 convert the result back to the nominal type of LHS
6243 so that the value we return always has the same type
6244 as the LHS argument. */
6246 if (olhstype == TREE_TYPE (result))
6250 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
6251 TREE_NO_WARNING (result) = 1;
6254 return convert_for_assignment (olhstype, result, "assignment",
6255 NULL_TREE, 0, complain);
6259 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs,
6260 tsubst_flags_t complain)
6262 if (processing_template_decl)
6263 return build_min_nt (MODOP_EXPR, lhs,
6264 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
6266 if (modifycode != NOP_EXPR)
6268 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
6269 make_node (modifycode),
6270 /*overloaded_p=*/NULL,
6274 TREE_NO_WARNING (rval) = 1;
6278 return cp_build_modify_expr (lhs, modifycode, rhs, complain);
6281 /* Helper function for get_delta_difference which assumes FROM is a base
6282 class of TO. Returns a delta for the conversion of pointer-to-member
6283 of FROM to pointer-to-member of TO. If the conversion is invalid,
6284 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
6285 If C_CAST_P is true, this conversion is taking place as part of a C-style
6289 get_delta_difference_1 (tree from, tree to, bool c_cast_p)
6294 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6295 if (kind == bk_inaccessible || kind == bk_ambig)
6297 error (" in pointer to member function conversion");
6298 return size_zero_node;
6302 if (kind != bk_via_virtual)
6303 return BINFO_OFFSET (binfo);
6305 /* FROM is a virtual base class of TO. Issue an error or warning
6306 depending on whether or not this is a reinterpret cast. */
6308 error ("pointer to member conversion via virtual base %qT",
6309 BINFO_TYPE (binfo_from_vbase (binfo)));
6311 return size_zero_node;
6318 /* Get difference in deltas for different pointer to member function
6319 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6320 the conversion is invalid, the constant is zero. If
6321 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6322 If C_CAST_P is true this conversion is taking place as part of a
6325 Note that the naming of FROM and TO is kind of backwards; the return
6326 value is what we add to a TO in order to get a FROM. They are named
6327 this way because we call this function to find out how to convert from
6328 a pointer to member of FROM to a pointer to member of TO. */
6331 get_delta_difference (tree from, tree to,
6332 bool allow_inverse_p,
6337 if (same_type_ignoring_top_level_qualifiers_p (from, to))
6338 /* Pointer to member of incomplete class is permitted*/
6339 result = size_zero_node;
6341 result = get_delta_difference_1 (from, to, c_cast_p);
6345 if (!allow_inverse_p)
6347 error_not_base_type (from, to);
6348 error (" in pointer to member conversion");
6349 result = size_zero_node;
6353 result = get_delta_difference_1 (to, from, c_cast_p);
6356 result = size_diffop (size_zero_node, result);
6359 error_not_base_type (from, to);
6360 error (" in pointer to member conversion");
6361 result = size_zero_node;
6366 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6370 /* Return a constructor for the pointer-to-member-function TYPE using
6371 the other components as specified. */
6374 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6379 VEC(constructor_elt, gc) *v;
6381 /* Pull the FIELD_DECLs out of the type. */
6382 pfn_field = TYPE_FIELDS (type);
6383 delta_field = TREE_CHAIN (pfn_field);
6385 /* Make sure DELTA has the type we want. */
6386 delta = convert_and_check (delta_type_node, delta);
6388 /* Convert to the correct target type if necessary. */
6389 pfn = fold_convert (TREE_TYPE (pfn_field), pfn);
6391 /* Finish creating the initializer. */
6392 v = VEC_alloc(constructor_elt, gc, 2);
6393 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6394 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6395 u = build_constructor (type, v);
6396 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6397 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6398 TREE_STATIC (u) = (TREE_CONSTANT (u)
6399 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6401 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6406 /* Build a constructor for a pointer to member function. It can be
6407 used to initialize global variables, local variable, or used
6408 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6411 If FORCE is nonzero, then force this conversion, even if
6412 we would rather not do it. Usually set when using an explicit
6413 cast. A C-style cast is being processed iff C_CAST_P is true.
6415 Return error_mark_node, if something goes wrong. */
6418 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6424 if (error_operand_p (pfn))
6425 return error_mark_node;
6427 pfn_type = TREE_TYPE (pfn);
6428 to_type = build_ptrmemfunc_type (type);
6430 /* Handle multiple conversions of pointer to member functions. */
6431 if (TYPE_PTRMEMFUNC_P (pfn_type))
6433 tree delta = NULL_TREE;
6434 tree npfn = NULL_TREE;
6438 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6439 error ("invalid conversion to type %qT from type %qT",
6442 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6443 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6447 /* We don't have to do any conversion to convert a
6448 pointer-to-member to its own type. But, we don't want to
6449 just return a PTRMEM_CST if there's an explicit cast; that
6450 cast should make the expression an invalid template argument. */
6451 if (TREE_CODE (pfn) != PTRMEM_CST)
6453 if (same_type_p (to_type, pfn_type))
6455 else if (integer_zerop (n))
6456 return build_reinterpret_cast (to_type, pfn,
6457 tf_warning_or_error);
6460 if (TREE_SIDE_EFFECTS (pfn))
6461 pfn = save_expr (pfn);
6463 /* Obtain the function pointer and the current DELTA. */
6464 if (TREE_CODE (pfn) == PTRMEM_CST)
6465 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6468 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6469 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6472 /* Just adjust the DELTA field. */
6473 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6474 (TREE_TYPE (delta), ptrdiff_type_node));
6475 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6476 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node,
6477 tf_warning_or_error);
6478 delta = cp_build_binary_op (PLUS_EXPR, delta, n, tf_warning_or_error);
6479 return build_ptrmemfunc1 (to_type, delta, npfn);
6482 /* Handle null pointer to member function conversions. */
6483 if (integer_zerop (pfn))
6485 pfn = build_c_cast (type, integer_zero_node);
6486 return build_ptrmemfunc1 (to_type,
6491 if (type_unknown_p (pfn))
6492 return instantiate_type (type, pfn, tf_warning_or_error);
6494 fn = TREE_OPERAND (pfn, 0);
6495 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6496 /* In a template, we will have preserved the
6498 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6499 return make_ptrmem_cst (to_type, fn);
6502 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6505 ??? There is no consistency as to the types returned for the above
6506 values. Some code acts as if it were a sizetype and some as if it were
6507 integer_type_node. */
6510 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6512 tree type = TREE_TYPE (cst);
6513 tree fn = PTRMEM_CST_MEMBER (cst);
6514 tree ptr_class, fn_class;
6516 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6518 /* The class that the function belongs to. */
6519 fn_class = DECL_CONTEXT (fn);
6521 /* The class that we're creating a pointer to member of. */
6522 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6524 /* First, calculate the adjustment to the function's class. */
6525 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6528 if (!DECL_VIRTUAL_P (fn))
6529 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6532 /* If we're dealing with a virtual function, we have to adjust 'this'
6533 again, to point to the base which provides the vtable entry for
6534 fn; the call will do the opposite adjustment. */
6535 tree orig_class = DECL_CONTEXT (fn);
6536 tree binfo = binfo_or_else (orig_class, fn_class);
6537 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6538 *delta, BINFO_OFFSET (binfo));
6539 *delta = fold_if_not_in_template (*delta);
6541 /* We set PFN to the vtable offset at which the function can be
6542 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6543 case delta is shifted left, and then incremented). */
6544 *pfn = DECL_VINDEX (fn);
6545 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6546 TYPE_SIZE_UNIT (vtable_entry_type));
6547 *pfn = fold_if_not_in_template (*pfn);
6549 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6551 case ptrmemfunc_vbit_in_pfn:
6552 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6554 *pfn = fold_if_not_in_template (*pfn);
6557 case ptrmemfunc_vbit_in_delta:
6558 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6559 *delta, integer_one_node);
6560 *delta = fold_if_not_in_template (*delta);
6561 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6562 *delta, integer_one_node);
6563 *delta = fold_if_not_in_template (*delta);
6570 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6571 *pfn = fold_if_not_in_template (*pfn);
6575 /* Return an expression for PFN from the pointer-to-member function
6579 pfn_from_ptrmemfunc (tree t)
6581 if (TREE_CODE (t) == PTRMEM_CST)
6586 expand_ptrmemfunc_cst (t, &delta, &pfn);
6591 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6594 /* Return an expression for DELTA from the pointer-to-member function
6598 delta_from_ptrmemfunc (tree t)
6600 if (TREE_CODE (t) == PTRMEM_CST)
6605 expand_ptrmemfunc_cst (t, &delta, &pfn);
6610 return build_ptrmemfunc_access_expr (t, delta_identifier);
6613 /* Convert value RHS to type TYPE as preparation for an assignment to
6614 an lvalue of type TYPE. ERRTYPE is a string to use in error
6615 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6616 are doing the conversion in order to pass the PARMNUMth argument of
6620 convert_for_assignment (tree type, tree rhs,
6621 const char *errtype, tree fndecl, int parmnum,
6622 tsubst_flags_t complain)
6625 enum tree_code coder;
6627 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6628 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6629 rhs = TREE_OPERAND (rhs, 0);
6631 rhstype = TREE_TYPE (rhs);
6632 coder = TREE_CODE (rhstype);
6634 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6635 && vector_types_convertible_p (type, rhstype, true))
6636 return convert (type, rhs);
6638 if (rhs == error_mark_node || rhstype == error_mark_node)
6639 return error_mark_node;
6640 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6641 return error_mark_node;
6643 /* The RHS of an assignment cannot have void type. */
6644 if (coder == VOID_TYPE)
6646 if (complain & tf_error)
6647 error ("void value not ignored as it ought to be");
6648 return error_mark_node;
6651 /* Simplify the RHS if possible. */
6652 if (TREE_CODE (rhs) == CONST_DECL)
6653 rhs = DECL_INITIAL (rhs);
6655 if (c_dialect_objc ())
6658 tree rname = fndecl;
6660 if (!strcmp (errtype, "assignment"))
6662 else if (!strcmp (errtype, "initialization"))
6666 tree selector = objc_message_selector ();
6670 if (selector && parmno > 1)
6677 if (objc_compare_types (type, rhstype, parmno, rname))
6678 return convert (type, rhs);
6683 The expression is implicitly converted (clause _conv_) to the
6684 cv-unqualified type of the left operand.
6686 We allow bad conversions here because by the time we get to this point
6687 we are committed to doing the conversion. If we end up doing a bad
6688 conversion, convert_like will complain. */
6689 if (!can_convert_arg_bad (type, rhstype, rhs))
6691 /* When -Wno-pmf-conversions is use, we just silently allow
6692 conversions from pointers-to-members to plain pointers. If
6693 the conversion doesn't work, cp_convert will complain. */
6695 && TYPE_PTR_P (type)
6696 && TYPE_PTRMEMFUNC_P (rhstype))
6697 rhs = cp_convert (strip_top_quals (type), rhs);
6700 if (complain & tf_error)
6702 /* If the right-hand side has unknown type, then it is an
6703 overloaded function. Call instantiate_type to get error
6705 if (rhstype == unknown_type_node)
6706 instantiate_type (type, rhs, tf_warning_or_error);
6708 error ("cannot convert %qT to %qT for argument %qP to %qD",
6709 rhstype, type, parmnum, fndecl);
6711 error ("cannot convert %qT to %qT in %s", rhstype, type,
6714 return error_mark_node;
6717 if (warn_missing_format_attribute)
6719 const enum tree_code codel = TREE_CODE (type);
6720 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6722 && check_missing_format_attribute (type, rhstype)
6723 && (complain & tf_warning))
6724 warning (OPT_Wmissing_format_attribute,
6725 "%s might be a candidate for a format attribute",
6729 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6731 if (warn_parentheses
6732 && type == boolean_type_node
6733 && TREE_CODE (rhs) == MODIFY_EXPR
6734 && !TREE_NO_WARNING (rhs)
6735 && TREE_TYPE (rhs) != boolean_type_node
6736 && (complain & tf_warning))
6738 warning (OPT_Wparentheses,
6739 "suggest parentheses around assignment used as truth value");
6740 TREE_NO_WARNING (rhs) = 1;
6743 return perform_implicit_conversion (strip_top_quals (type), rhs, complain);
6746 /* Convert RHS to be of type TYPE.
6747 If EXP is nonzero, it is the target of the initialization.
6748 ERRTYPE is a string to use in error messages.
6750 Two major differences between the behavior of
6751 `convert_for_assignment' and `convert_for_initialization'
6752 are that references are bashed in the former, while
6753 copied in the latter, and aggregates are assigned in
6754 the former (operator=) while initialized in the
6757 If using constructor make sure no conversion operator exists, if one does
6758 exist, an ambiguity exists.
6760 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6763 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6764 const char *errtype, tree fndecl, int parmnum,
6765 tsubst_flags_t complain)
6767 enum tree_code codel = TREE_CODE (type);
6769 enum tree_code coder;
6771 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6772 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6773 if (TREE_CODE (rhs) == NOP_EXPR
6774 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6775 && codel != REFERENCE_TYPE)
6776 rhs = TREE_OPERAND (rhs, 0);
6778 if (type == error_mark_node
6779 || rhs == error_mark_node
6780 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6781 return error_mark_node;
6783 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6784 && TREE_CODE (type) != ARRAY_TYPE
6785 && (TREE_CODE (type) != REFERENCE_TYPE
6786 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6787 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6788 && (TREE_CODE (type) != REFERENCE_TYPE
6789 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6790 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6791 rhs = decay_conversion (rhs);
6793 rhstype = TREE_TYPE (rhs);
6794 coder = TREE_CODE (rhstype);
6796 if (coder == ERROR_MARK)
6797 return error_mark_node;
6799 /* We accept references to incomplete types, so we can
6800 return here before checking if RHS is of complete type. */
6802 if (codel == REFERENCE_TYPE)
6804 /* This should eventually happen in convert_arguments. */
6805 int savew = 0, savee = 0;
6808 savew = warningcount, savee = errorcount;
6809 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6813 if (warningcount > savew)
6814 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6815 else if (errorcount > savee)
6816 error ("in passing argument %P of %q+D", parmnum, fndecl);
6822 exp = require_complete_type (exp);
6823 if (exp == error_mark_node)
6824 return error_mark_node;
6826 rhstype = non_reference (rhstype);
6828 type = complete_type (type);
6830 if (MAYBE_CLASS_TYPE_P (type))
6831 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6833 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum,
6837 /* If RETVAL is the address of, or a reference to, a local variable or
6838 temporary give an appropriate warning. */
6841 maybe_warn_about_returning_address_of_local (tree retval)
6843 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6844 tree whats_returned = retval;
6848 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6849 whats_returned = TREE_OPERAND (whats_returned, 1);
6850 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6851 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6852 || TREE_CODE (whats_returned) == NOP_EXPR)
6853 whats_returned = TREE_OPERAND (whats_returned, 0);
6858 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6860 whats_returned = TREE_OPERAND (whats_returned, 0);
6862 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6864 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6865 || TREE_CODE (whats_returned) == TARGET_EXPR)
6867 warning (0, "returning reference to temporary");
6870 if (TREE_CODE (whats_returned) == VAR_DECL
6871 && DECL_NAME (whats_returned)
6872 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6874 warning (0, "reference to non-lvalue returned");
6879 while (TREE_CODE (whats_returned) == COMPONENT_REF
6880 || TREE_CODE (whats_returned) == ARRAY_REF)
6881 whats_returned = TREE_OPERAND (whats_returned, 0);
6883 if (DECL_P (whats_returned)
6884 && DECL_NAME (whats_returned)
6885 && DECL_FUNCTION_SCOPE_P (whats_returned)
6886 && !(TREE_STATIC (whats_returned)
6887 || TREE_PUBLIC (whats_returned)))
6889 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6890 warning (0, "reference to local variable %q+D returned",
6893 warning (0, "address of local variable %q+D returned",
6899 /* Check that returning RETVAL from the current function is valid.
6900 Return an expression explicitly showing all conversions required to
6901 change RETVAL into the function return type, and to assign it to
6902 the DECL_RESULT for the function. Set *NO_WARNING to true if
6903 code reaches end of non-void function warning shouldn't be issued
6904 on this RETURN_EXPR. */
6907 check_return_expr (tree retval, bool *no_warning)
6910 /* The type actually returned by the function, after any
6913 int fn_returns_value_p;
6914 bool named_return_value_okay_p;
6916 *no_warning = false;
6918 /* A `volatile' function is one that isn't supposed to return, ever.
6919 (This is a G++ extension, used to get better code for functions
6920 that call the `volatile' function.) */
6921 if (TREE_THIS_VOLATILE (current_function_decl))
6922 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6924 /* Check for various simple errors. */
6925 if (DECL_DESTRUCTOR_P (current_function_decl))
6928 error ("returning a value from a destructor");
6931 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6933 if (in_function_try_handler)
6934 /* If a return statement appears in a handler of the
6935 function-try-block of a constructor, the program is ill-formed. */
6936 error ("cannot return from a handler of a function-try-block of a constructor");
6938 /* You can't return a value from a constructor. */
6939 error ("returning a value from a constructor");
6943 if (processing_template_decl)
6945 current_function_returns_value = 1;
6946 if (check_for_bare_parameter_packs (retval))
6947 retval = error_mark_node;
6951 /* When no explicit return-value is given in a function with a named
6952 return value, the named return value is used. */
6953 result = DECL_RESULT (current_function_decl);
6954 valtype = TREE_TYPE (result);
6955 gcc_assert (valtype != NULL_TREE);
6956 fn_returns_value_p = !VOID_TYPE_P (valtype);
6957 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6960 /* Check for a return statement with no return value in a function
6961 that's supposed to return a value. */
6962 if (!retval && fn_returns_value_p)
6964 pedwarn ("return-statement with no value, in function returning %qT",
6966 /* Clear this, so finish_function won't say that we reach the
6967 end of a non-void function (which we don't, we gave a
6969 current_function_returns_null = 0;
6970 /* And signal caller that TREE_NO_WARNING should be set on the
6971 RETURN_EXPR to avoid control reaches end of non-void function
6972 warnings in tree-cfg.c. */
6975 /* Check for a return statement with a value in a function that
6976 isn't supposed to return a value. */
6977 else if (retval && !fn_returns_value_p)
6979 if (VOID_TYPE_P (TREE_TYPE (retval)))
6980 /* You can return a `void' value from a function of `void'
6981 type. In that case, we have to evaluate the expression for
6982 its side-effects. */
6983 finish_expr_stmt (retval);
6985 pedwarn ("return-statement with a value, in function "
6986 "returning 'void'");
6988 current_function_returns_null = 1;
6990 /* There's really no value to return, after all. */
6994 /* Remember that this function can sometimes return without a
6996 current_function_returns_null = 1;
6998 /* Remember that this function did return a value. */
6999 current_function_returns_value = 1;
7001 /* Check for erroneous operands -- but after giving ourselves a
7002 chance to provide an error about returning a value from a void
7004 if (error_operand_p (retval))
7006 current_function_return_value = error_mark_node;
7007 return error_mark_node;
7010 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
7011 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
7012 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
7013 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
7015 && retval && null_ptr_cst_p (retval))
7016 warning (0, "%<operator new%> must not return NULL unless it is "
7017 "declared %<throw()%> (or -fcheck-new is in effect)");
7019 /* Effective C++ rule 15. See also start_function. */
7021 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
7025 /* The function return type must be a reference to the current
7027 if (TREE_CODE (valtype) == REFERENCE_TYPE
7028 && same_type_ignoring_top_level_qualifiers_p
7029 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
7031 /* Returning '*this' is obviously OK. */
7032 if (retval == current_class_ref)
7034 /* If we are calling a function whose return type is the same of
7035 the current class reference, it is ok. */
7036 else if (TREE_CODE (retval) == INDIRECT_REF
7037 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
7042 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
7045 /* The fabled Named Return Value optimization, as per [class.copy]/15:
7047 [...] For a function with a class return type, if the expression
7048 in the return statement is the name of a local object, and the cv-
7049 unqualified type of the local object is the same as the function
7050 return type, an implementation is permitted to omit creating the tem-
7051 porary object to hold the function return value [...]
7053 So, if this is a value-returning function that always returns the same
7054 local variable, remember it.
7056 It might be nice to be more flexible, and choose the first suitable
7057 variable even if the function sometimes returns something else, but
7058 then we run the risk of clobbering the variable we chose if the other
7059 returned expression uses the chosen variable somehow. And people expect
7060 this restriction, anyway. (jason 2000-11-19)
7062 See finish_function and finalize_nrv for the rest of this optimization. */
7064 named_return_value_okay_p =
7065 (retval != NULL_TREE
7066 /* Must be a local, automatic variable. */
7067 && TREE_CODE (retval) == VAR_DECL
7068 && DECL_CONTEXT (retval) == current_function_decl
7069 && ! TREE_STATIC (retval)
7070 && ! DECL_ANON_UNION_VAR_P (retval)
7071 && (DECL_ALIGN (retval)
7072 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
7073 /* The cv-unqualified type of the returned value must be the
7074 same as the cv-unqualified return type of the
7076 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
7078 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
7079 /* And the returned value must be non-volatile. */
7080 && ! TYPE_VOLATILE (TREE_TYPE (retval)));
7082 if (fn_returns_value_p && flag_elide_constructors)
7084 if (named_return_value_okay_p
7085 && (current_function_return_value == NULL_TREE
7086 || current_function_return_value == retval))
7087 current_function_return_value = retval;
7089 current_function_return_value = error_mark_node;
7092 /* We don't need to do any conversions when there's nothing being
7097 /* Do any required conversions. */
7098 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
7099 /* No conversions are required. */
7103 /* The type the function is declared to return. */
7104 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
7105 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
7107 /* The functype's return type will have been set to void, if it
7108 was an incomplete type. Just treat this as 'return;' */
7109 if (VOID_TYPE_P (functype))
7110 return error_mark_node;
7112 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
7113 treated as an rvalue for the purposes of overload resolution to
7114 favor move constructors over copy constructors. */
7115 if ((cxx_dialect != cxx98)
7116 && named_return_value_okay_p
7117 /* The variable must not have the `volatile' qualifier. */
7118 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
7119 /* The return type must be a class type. */
7120 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
7121 flags = flags | LOOKUP_PREFER_RVALUE;
7123 /* First convert the value to the function's return type, then
7124 to the type of return value's location to handle the
7125 case that functype is smaller than the valtype. */
7126 retval = convert_for_initialization
7127 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0,
7128 tf_warning_or_error);
7129 retval = convert (valtype, retval);
7131 /* If the conversion failed, treat this just like `return;'. */
7132 if (retval == error_mark_node)
7134 /* We can't initialize a register from a AGGR_INIT_EXPR. */
7135 else if (! current_function_returns_struct
7136 && TREE_CODE (retval) == TARGET_EXPR
7137 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
7138 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
7139 TREE_OPERAND (retval, 0));
7141 maybe_warn_about_returning_address_of_local (retval);
7144 /* Actually copy the value returned into the appropriate location. */
7145 if (retval && retval != result)
7146 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
7152 /* Returns nonzero if the pointer-type FROM can be converted to the
7153 pointer-type TO via a qualification conversion. If CONSTP is -1,
7154 then we return nonzero if the pointers are similar, and the
7155 cv-qualification signature of FROM is a proper subset of that of TO.
7157 If CONSTP is positive, then all outer pointers have been
7161 comp_ptr_ttypes_real (tree to, tree from, int constp)
7163 bool to_more_cv_qualified = false;
7165 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7167 if (TREE_CODE (to) != TREE_CODE (from))
7170 if (TREE_CODE (from) == OFFSET_TYPE
7171 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
7172 TYPE_OFFSET_BASETYPE (to)))
7175 /* Const and volatile mean something different for function types,
7176 so the usual checks are not appropriate. */
7177 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
7179 /* In Objective-C++, some types may have been 'volatilized' by
7180 the compiler for EH; when comparing them here, the volatile
7181 qualification must be ignored. */
7182 bool objc_quals_match = objc_type_quals_match (to, from);
7184 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
7187 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
7191 to_more_cv_qualified = true;
7195 constp &= TYPE_READONLY (to);
7198 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
7199 return ((constp >= 0 || to_more_cv_qualified)
7200 && same_type_ignoring_top_level_qualifiers_p (to, from));
7204 /* When comparing, say, char ** to char const **, this function takes
7205 the 'char *' and 'char const *'. Do not pass non-pointer/reference
7206 types to this function. */
7209 comp_ptr_ttypes (tree to, tree from)
7211 return comp_ptr_ttypes_real (to, from, 1);
7214 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
7215 type or inheritance-related types, regardless of cv-quals. */
7218 ptr_reasonably_similar (const_tree to, const_tree from)
7220 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7222 /* Any target type is similar enough to void. */
7223 if (TREE_CODE (to) == VOID_TYPE
7224 || TREE_CODE (from) == VOID_TYPE)
7227 if (TREE_CODE (to) != TREE_CODE (from))
7230 if (TREE_CODE (from) == OFFSET_TYPE
7231 && comptypes (TYPE_OFFSET_BASETYPE (to),
7232 TYPE_OFFSET_BASETYPE (from),
7233 COMPARE_BASE | COMPARE_DERIVED))
7236 if (TREE_CODE (to) == VECTOR_TYPE
7237 && vector_types_convertible_p (to, from, false))
7240 if (TREE_CODE (to) == INTEGER_TYPE
7241 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
7244 if (TREE_CODE (to) == FUNCTION_TYPE)
7247 if (TREE_CODE (to) != POINTER_TYPE)
7249 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
7250 COMPARE_BASE | COMPARE_DERIVED);
7254 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
7255 pointer-to-member types) are the same, ignoring cv-qualification at
7259 comp_ptr_ttypes_const (tree to, tree from)
7261 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
7263 if (TREE_CODE (to) != TREE_CODE (from))
7266 if (TREE_CODE (from) == OFFSET_TYPE
7267 && same_type_p (TYPE_OFFSET_BASETYPE (from),
7268 TYPE_OFFSET_BASETYPE (to)))
7271 if (TREE_CODE (to) != POINTER_TYPE)
7272 return same_type_ignoring_top_level_qualifiers_p (to, from);
7276 /* Returns the type qualifiers for this type, including the qualifiers on the
7277 elements for an array type. */
7280 cp_type_quals (const_tree type)
7282 /* This CONST_CAST is okay because strip_array_types returns it's
7283 argument unmodified and we assign it to a const_tree. */
7284 type = strip_array_types (CONST_CAST_TREE(type));
7285 if (type == error_mark_node)
7286 return TYPE_UNQUALIFIED;
7287 return TYPE_QUALS (type);
7290 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
7294 cp_type_readonly (const_tree type)
7296 /* This CONST_CAST is okay because strip_array_types returns it's
7297 argument unmodified and we assign it to a const_tree. */
7298 type = strip_array_types (CONST_CAST_TREE(type));
7299 return TYPE_READONLY (type);
7302 /* Returns nonzero if the TYPE contains a mutable member. */
7305 cp_has_mutable_p (const_tree type)
7307 /* This CONST_CAST is okay because strip_array_types returns it's
7308 argument unmodified and we assign it to a const_tree. */
7309 type = strip_array_types (CONST_CAST_TREE(type));
7311 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
7314 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
7315 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
7316 approximation. In particular, consider:
7319 struct S { int i; };
7320 const S s = { f(); }
7322 Here, we will make "s" as TREE_READONLY (because it is declared
7323 "const") -- only to reverse ourselves upon seeing that the
7324 initializer is non-constant. */
7327 cp_apply_type_quals_to_decl (int type_quals, tree decl)
7329 tree type = TREE_TYPE (decl);
7331 if (type == error_mark_node)
7334 if (TREE_CODE (type) == FUNCTION_TYPE
7335 && type_quals != TYPE_UNQUALIFIED)
7337 /* This was an error in C++98 (cv-qualifiers cannot be added to
7338 a function type), but DR 295 makes the code well-formed by
7339 dropping the extra qualifiers. */
7342 tree bad_type = build_qualified_type (type, type_quals);
7343 pedwarn ("ignoring %qV qualifiers added to function type %qT",
7347 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
7351 /* Avoid setting TREE_READONLY incorrectly. */
7352 if (/* If the object has a constructor, the constructor may modify
7354 TYPE_NEEDS_CONSTRUCTING (type)
7355 /* If the type isn't complete, we don't know yet if it will need
7357 || !COMPLETE_TYPE_P (type)
7358 /* If the type has a mutable component, that component might be
7360 || TYPE_HAS_MUTABLE_P (type))
7361 type_quals &= ~TYPE_QUAL_CONST;
7363 c_apply_type_quals_to_decl (type_quals, decl);
7366 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7367 exemplar types such that casting T1 to T2 is casting away constness
7368 if and only if there is no implicit conversion from T1 to T2. */
7371 casts_away_constness_r (tree *t1, tree *t2)
7376 /* [expr.const.cast]
7378 For multi-level pointer to members and multi-level mixed pointers
7379 and pointers to members (conv.qual), the "member" aspect of a
7380 pointer to member level is ignored when determining if a const
7381 cv-qualifier has been cast away. */
7382 /* [expr.const.cast]
7384 For two pointer types:
7386 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7387 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7390 casting from X1 to X2 casts away constness if, for a non-pointer
7391 type T there does not exist an implicit conversion (clause
7394 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7398 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7399 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7400 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7402 *t1 = cp_build_qualified_type (void_type_node,
7403 cp_type_quals (*t1));
7404 *t2 = cp_build_qualified_type (void_type_node,
7405 cp_type_quals (*t2));
7409 quals1 = cp_type_quals (*t1);
7410 quals2 = cp_type_quals (*t2);
7412 if (TYPE_PTRMEM_P (*t1))
7413 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7415 *t1 = TREE_TYPE (*t1);
7416 if (TYPE_PTRMEM_P (*t2))
7417 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7419 *t2 = TREE_TYPE (*t2);
7421 casts_away_constness_r (t1, t2);
7422 *t1 = build_pointer_type (*t1);
7423 *t2 = build_pointer_type (*t2);
7424 *t1 = cp_build_qualified_type (*t1, quals1);
7425 *t2 = cp_build_qualified_type (*t2, quals2);
7428 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7432 casts_away_constness (tree t1, tree t2)
7434 if (TREE_CODE (t2) == REFERENCE_TYPE)
7436 /* [expr.const.cast]
7438 Casting from an lvalue of type T1 to an lvalue of type T2
7439 using a reference cast casts away constness if a cast from an
7440 rvalue of type "pointer to T1" to the type "pointer to T2"
7441 casts away constness. */
7442 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7443 return casts_away_constness (build_pointer_type (t1),
7444 build_pointer_type (TREE_TYPE (t2)));
7447 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7448 /* [expr.const.cast]
7450 Casting from an rvalue of type "pointer to data member of X
7451 of type T1" to the type "pointer to data member of Y of type
7452 T2" casts away constness if a cast from an rvalue of type
7453 "pointer to T1" to the type "pointer to T2" casts away
7455 return casts_away_constness
7456 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7457 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7459 /* Casting away constness is only something that makes sense for
7460 pointer or reference types. */
7461 if (TREE_CODE (t1) != POINTER_TYPE
7462 || TREE_CODE (t2) != POINTER_TYPE)
7465 /* Top-level qualifiers don't matter. */
7466 t1 = TYPE_MAIN_VARIANT (t1);
7467 t2 = TYPE_MAIN_VARIANT (t2);
7468 casts_away_constness_r (&t1, &t2);
7469 if (!can_convert (t2, t1))
7475 /* If T is a REFERENCE_TYPE return the type to which T refers.
7476 Otherwise, return T itself. */
7479 non_reference (tree t)
7481 if (TREE_CODE (t) == REFERENCE_TYPE)
7487 /* Return nonzero if REF is an lvalue valid for this language;
7488 otherwise, print an error message and return zero. USE says
7489 how the lvalue is being used and so selects the error message. */
7492 lvalue_or_else (const_tree ref, enum lvalue_use use, tsubst_flags_t complain)
7494 int win = lvalue_p (ref);
7496 if (!win && (complain & tf_error))