1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
46 static tree pfn_from_ptrmemfunc (tree);
47 static tree convert_for_assignment (tree, tree, const char *, tree, int);
48 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
49 static tree rationalize_conditional_expr (enum tree_code, tree);
50 static int comp_ptr_ttypes_real (tree, tree, int);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
60 static tree convert_arguments (tree, tree, tree, int);
62 /* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
68 require_complete_type (tree value)
72 if (processing_template_decl || value == error_mark_node)
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
78 type = TREE_TYPE (value);
80 if (type == error_mark_node)
81 return error_mark_node;
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
87 if (complete_type_or_else (type, value))
90 return error_mark_node;
93 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
99 complete_type (tree type)
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
104 return error_mark_node;
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
110 tree t = complete_type (TREE_TYPE (type));
111 unsigned int needs_constructing, has_nontrivial_dtor;
112 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
115 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
117 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
120 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
121 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
124 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
125 instantiate_class_template (TYPE_MAIN_VARIANT (type));
130 /* Like complete_type, but issue an error if the TYPE cannot be completed.
131 VALUE is used for informative diagnostics.
132 Returns NULL_TREE if the type cannot be made complete. */
135 complete_type_or_else (tree type, tree value)
137 type = complete_type (type);
138 if (type == error_mark_node)
139 /* We already issued an error. */
141 else if (!COMPLETE_TYPE_P (type))
143 cxx_incomplete_type_diagnostic (value, type, 0);
150 /* Return truthvalue of whether type of EXP is instantiated. */
153 type_unknown_p (tree exp)
155 return (TREE_CODE (exp) == TREE_LIST
156 || TREE_TYPE (exp) == unknown_type_node);
160 /* Return the common type of two parameter lists.
161 We assume that comptypes has already been done and returned 1;
162 if that isn't so, this may crash.
164 As an optimization, free the space we allocate if the parameter
165 lists are already common. */
168 commonparms (tree p1, tree p2)
170 tree oldargs = p1, newargs, n;
174 len = list_length (p1);
175 newargs = tree_last (p1);
177 if (newargs == void_list_node)
186 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
191 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
193 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
195 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
198 else if (! TREE_PURPOSE (p1))
200 if (TREE_PURPOSE (p2))
202 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
208 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
210 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
212 if (TREE_VALUE (p1) != TREE_VALUE (p2))
215 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
218 TREE_VALUE (n) = TREE_VALUE (p1);
226 /* Given a type, perhaps copied for a typedef,
227 find the "original" version of it. */
229 original_type (tree t)
231 int quals = cp_type_quals (t);
232 while (t != error_mark_node
233 && TYPE_NAME (t) != NULL_TREE)
235 tree x = TYPE_NAME (t);
236 if (TREE_CODE (x) != TYPE_DECL)
238 x = DECL_ORIGINAL_TYPE (x);
243 return cp_build_qualified_type (t, quals);
246 /* T1 and T2 are arithmetic or enumeration types. Return the type
247 that will result from the "usual arithmetic conversions" on T1 and
248 T2 as described in [expr]. */
251 type_after_usual_arithmetic_conversions (tree t1, tree t2)
253 enum tree_code code1 = TREE_CODE (t1);
254 enum tree_code code2 = TREE_CODE (t2);
257 /* FIXME: Attributes. */
258 gcc_assert (ARITHMETIC_TYPE_P (t1)
259 || TREE_CODE (t1) == COMPLEX_TYPE
260 || TREE_CODE (t1) == VECTOR_TYPE
261 || TREE_CODE (t1) == ENUMERAL_TYPE);
262 gcc_assert (ARITHMETIC_TYPE_P (t2)
263 || TREE_CODE (t2) == COMPLEX_TYPE
264 || TREE_CODE (t2) == VECTOR_TYPE
265 || TREE_CODE (t2) == ENUMERAL_TYPE);
267 /* In what follows, we slightly generalize the rules given in [expr] so
268 as to deal with `long long' and `complex'. First, merge the
270 attributes = (*targetm.merge_type_attributes) (t1, t2);
272 /* If one type is complex, form the common type of the non-complex
273 components, then make that complex. Use T1 or T2 if it is the
275 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
277 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
278 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
280 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
282 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
283 return build_type_attribute_variant (t1, attributes);
284 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
285 return build_type_attribute_variant (t2, attributes);
287 return build_type_attribute_variant (build_complex_type (subtype),
291 if (code1 == VECTOR_TYPE)
293 /* When we get here we should have two vectors of the same size.
294 Just prefer the unsigned one if present. */
295 if (TYPE_UNSIGNED (t1))
296 return build_type_attribute_variant (t1, attributes);
298 return build_type_attribute_variant (t2, attributes);
301 /* If only one is real, use it as the result. */
302 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
303 return build_type_attribute_variant (t1, attributes);
304 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
305 return build_type_attribute_variant (t2, attributes);
307 /* Perform the integral promotions. */
308 if (code1 != REAL_TYPE)
310 t1 = type_promotes_to (t1);
311 t2 = type_promotes_to (t2);
314 /* Both real or both integers; use the one with greater precision. */
315 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
316 return build_type_attribute_variant (t1, attributes);
317 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
318 return build_type_attribute_variant (t2, attributes);
320 /* The types are the same; no need to do anything fancy. */
321 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
322 return build_type_attribute_variant (t1, attributes);
324 if (code1 != REAL_TYPE)
326 /* If one is a sizetype, use it so size_binop doesn't blow up. */
327 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
328 return build_type_attribute_variant (t1, attributes);
329 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
330 return build_type_attribute_variant (t2, attributes);
332 /* If one is unsigned long long, then convert the other to unsigned
334 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
335 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
336 return build_type_attribute_variant (long_long_unsigned_type_node,
338 /* If one is a long long, and the other is an unsigned long, and
339 long long can represent all the values of an unsigned long, then
340 convert to a long long. Otherwise, convert to an unsigned long
341 long. Otherwise, if either operand is long long, convert the
344 Since we're here, we know the TYPE_PRECISION is the same;
345 therefore converting to long long cannot represent all the values
346 of an unsigned long, so we choose unsigned long long in that
348 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
349 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
351 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
352 ? long_long_unsigned_type_node
353 : long_long_integer_type_node);
354 return build_type_attribute_variant (t, attributes);
357 /* Go through the same procedure, but for longs. */
358 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
359 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
360 return build_type_attribute_variant (long_unsigned_type_node,
362 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
363 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
365 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
366 ? long_unsigned_type_node : long_integer_type_node);
367 return build_type_attribute_variant (t, attributes);
369 /* Otherwise prefer the unsigned one. */
370 if (TYPE_UNSIGNED (t1))
371 return build_type_attribute_variant (t1, attributes);
373 return build_type_attribute_variant (t2, attributes);
377 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
378 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
379 return build_type_attribute_variant (long_double_type_node,
381 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
382 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
383 return build_type_attribute_variant (double_type_node,
385 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
386 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
387 return build_type_attribute_variant (float_type_node,
390 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
391 the standard C++ floating-point types. Logic earlier in this
392 function has already eliminated the possibility that
393 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
394 compelling reason to choose one or the other. */
395 return build_type_attribute_variant (t1, attributes);
399 /* Subroutine of composite_pointer_type to implement the recursive
400 case. See that function for documentation fo the parameters. */
403 composite_pointer_type_r (tree t1, tree t2, const char* location)
410 /* Determine the types pointed to by T1 and T2. */
411 if (TREE_CODE (t1) == POINTER_TYPE)
413 pointee1 = TREE_TYPE (t1);
414 pointee2 = TREE_TYPE (t2);
418 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
419 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
424 Otherwise, the composite pointer type is a pointer type
425 similar (_conv.qual_) to the type of one of the operands,
426 with a cv-qualification signature (_conv.qual_) that is the
427 union of the cv-qualification signatures of the operand
429 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
430 result_type = pointee1;
431 else if ((TREE_CODE (pointee1) == POINTER_TYPE
432 && TREE_CODE (pointee2) == POINTER_TYPE)
433 || (TYPE_PTR_TO_MEMBER_P (pointee1)
434 && TYPE_PTR_TO_MEMBER_P (pointee2)))
435 result_type = composite_pointer_type_r (pointee1, pointee2, location);
438 pedwarn ("%s between distinct pointer types %qT and %qT "
441 result_type = void_type_node;
443 result_type = cp_build_qualified_type (result_type,
444 (cp_type_quals (pointee1)
445 | cp_type_quals (pointee2)));
446 /* If the original types were pointers to members, so is the
448 if (TYPE_PTR_TO_MEMBER_P (t1))
450 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
451 TYPE_PTRMEM_CLASS_TYPE (t2)))
452 pedwarn ("%s between distinct pointer types %qT and %qT "
455 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
459 result_type = build_pointer_type (result_type);
461 /* Merge the attributes. */
462 attributes = (*targetm.merge_type_attributes) (t1, t2);
463 return build_type_attribute_variant (result_type, attributes);
466 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
467 ARG1 and ARG2 are the values with those types. The LOCATION is a
468 string describing the current location, in case an error occurs.
470 This routine also implements the computation of a common type for
471 pointers-to-members as per [expr.eq]. */
474 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
475 const char* location)
482 If one operand is a null pointer constant, the composite pointer
483 type is the type of the other operand. */
484 if (null_ptr_cst_p (arg1))
486 if (null_ptr_cst_p (arg2))
493 If one of the operands has type "pointer to cv1 void*", then
494 the other has type "pointer to cv2T", and the composite pointer
495 type is "pointer to cv12 void", where cv12 is the union of cv1
498 If either type is a pointer to void, make sure it is T1. */
499 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
507 /* Now, if T1 is a pointer to void, merge the qualifiers. */
508 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
513 if (pedantic && TYPE_PTRFN_P (t2))
514 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
515 "and pointer-to-function", location);
517 = cp_build_qualified_type (void_type_node,
518 (cp_type_quals (TREE_TYPE (t1))
519 | cp_type_quals (TREE_TYPE (t2))));
520 result_type = build_pointer_type (result_type);
521 /* Merge the attributes. */
522 attributes = (*targetm.merge_type_attributes) (t1, t2);
523 return build_type_attribute_variant (result_type, attributes);
526 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
527 && TREE_CODE (t2) == POINTER_TYPE)
529 if (objc_compare_types (t1, t2, -3, NULL_TREE))
533 /* [expr.eq] permits the application of a pointer conversion to
534 bring the pointers to a common type. */
535 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
536 && CLASS_TYPE_P (TREE_TYPE (t1))
537 && CLASS_TYPE_P (TREE_TYPE (t2))
538 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
541 class1 = TREE_TYPE (t1);
542 class2 = TREE_TYPE (t2);
544 if (DERIVED_FROM_P (class1, class2))
545 t2 = (build_pointer_type
546 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
547 else if (DERIVED_FROM_P (class2, class1))
548 t1 = (build_pointer_type
549 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
552 error ("%s between distinct pointer types %qT and %qT "
553 "lacks a cast", location, t1, t2);
554 return error_mark_node;
557 /* [expr.eq] permits the application of a pointer-to-member
558 conversion to change the class type of one of the types. */
559 else if (TYPE_PTR_TO_MEMBER_P (t1)
560 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
561 TYPE_PTRMEM_CLASS_TYPE (t2)))
563 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
564 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
566 if (DERIVED_FROM_P (class1, class2))
567 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
568 else if (DERIVED_FROM_P (class2, class1))
569 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
572 error ("%s between distinct pointer-to-member types %qT and %qT "
573 "lacks a cast", location, t1, t2);
574 return error_mark_node;
578 return composite_pointer_type_r (t1, t2, location);
581 /* Return the merged type of two types.
582 We assume that comptypes has already been done and returned 1;
583 if that isn't so, this may crash.
585 This just combines attributes and default arguments; any other
586 differences would cause the two types to compare unalike. */
589 merge_types (tree t1, tree t2)
591 enum tree_code code1;
592 enum tree_code code2;
595 /* Save time if the two types are the same. */
598 if (original_type (t1) == original_type (t2))
601 /* If one type is nonsense, use the other. */
602 if (t1 == error_mark_node)
604 if (t2 == error_mark_node)
607 /* Merge the attributes. */
608 attributes = (*targetm.merge_type_attributes) (t1, t2);
610 if (TYPE_PTRMEMFUNC_P (t1))
611 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
612 if (TYPE_PTRMEMFUNC_P (t2))
613 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
615 code1 = TREE_CODE (t1);
616 code2 = TREE_CODE (t2);
622 /* For two pointers, do this recursively on the target type. */
624 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
625 int quals = cp_type_quals (t1);
627 if (code1 == POINTER_TYPE)
628 t1 = build_pointer_type (target);
630 t1 = build_reference_type (target);
631 t1 = build_type_attribute_variant (t1, attributes);
632 t1 = cp_build_qualified_type (t1, quals);
634 if (TREE_CODE (target) == METHOD_TYPE)
635 t1 = build_ptrmemfunc_type (t1);
644 quals = cp_type_quals (t1);
645 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
646 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
647 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
649 t1 = cp_build_qualified_type (t1, quals);
655 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
656 /* Save space: see if the result is identical to one of the args. */
657 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
658 return build_type_attribute_variant (t1, attributes);
659 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
660 return build_type_attribute_variant (t2, attributes);
661 /* Merge the element types, and have a size if either arg has one. */
662 t1 = build_cplus_array_type
663 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
668 /* Function types: prefer the one that specified arg types.
669 If both do, merge the arg types. Also merge the return types. */
671 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
672 tree p1 = TYPE_ARG_TYPES (t1);
673 tree p2 = TYPE_ARG_TYPES (t2);
676 /* Save space: see if the result is identical to one of the args. */
677 if (valtype == TREE_TYPE (t1) && ! p2)
678 return cp_build_type_attribute_variant (t1, attributes);
679 if (valtype == TREE_TYPE (t2) && ! p1)
680 return cp_build_type_attribute_variant (t2, attributes);
682 /* Simple way if one arg fails to specify argument types. */
683 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
685 rval = build_function_type (valtype, p2);
686 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
687 rval = build_exception_variant (rval, raises);
688 return cp_build_type_attribute_variant (rval, attributes);
690 raises = TYPE_RAISES_EXCEPTIONS (t1);
691 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
693 rval = build_function_type (valtype, p1);
695 rval = build_exception_variant (rval, raises);
696 return cp_build_type_attribute_variant (rval, attributes);
699 rval = build_function_type (valtype, commonparms (p1, p2));
700 t1 = build_exception_variant (rval, raises);
706 /* Get this value the long way, since TYPE_METHOD_BASETYPE
707 is just the main variant of this. */
708 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
709 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
712 /* If this was a member function type, get back to the
713 original type of type member function (i.e., without
714 the class instance variable up front. */
715 t1 = build_function_type (TREE_TYPE (t1),
716 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
717 t2 = build_function_type (TREE_TYPE (t2),
718 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
719 t3 = merge_types (t1, t2);
720 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
721 TYPE_ARG_TYPES (t3));
722 t1 = build_exception_variant (t3, raises);
727 /* There is no need to merge attributes into a TYPENAME_TYPE.
728 When the type is instantiated it will have whatever
729 attributes result from the instantiation. */
735 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
737 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
740 return cp_build_type_attribute_variant (t1, attributes);
743 /* Return the common type of two types.
744 We assume that comptypes has already been done and returned 1;
745 if that isn't so, this may crash.
747 This is the type for the result of most arithmetic operations
748 if the operands have the given two types. */
751 common_type (tree t1, tree t2)
753 enum tree_code code1;
754 enum tree_code code2;
756 /* If one type is nonsense, bail. */
757 if (t1 == error_mark_node || t2 == error_mark_node)
758 return error_mark_node;
760 code1 = TREE_CODE (t1);
761 code2 = TREE_CODE (t2);
763 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
764 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
765 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
766 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
767 return type_after_usual_arithmetic_conversions (t1, t2);
769 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
770 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
771 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
772 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
778 /* Compare two exception specifier types for exactness or subsetness, if
779 allowed. Returns false for mismatch, true for match (same, or
782 [except.spec] "If a class X ... objects of class X or any class publicly
783 and unambiguously derived from X. Similarly, if a pointer type Y * ...
784 exceptions of type Y * or that are pointers to any type publicly and
785 unambiguously derived from Y. Otherwise a function only allows exceptions
786 that have the same type ..."
787 This does not mention cv qualifiers and is different to what throw
788 [except.throw] and catch [except.catch] will do. They will ignore the
789 top level cv qualifiers, and allow qualifiers in the pointer to class
792 We implement the letter of the standard. */
795 comp_except_types (tree a, tree b, bool exact)
797 if (same_type_p (a, b))
801 if (cp_type_quals (a) || cp_type_quals (b))
804 if (TREE_CODE (a) == POINTER_TYPE
805 && TREE_CODE (b) == POINTER_TYPE)
809 if (cp_type_quals (a) || cp_type_quals (b))
813 if (TREE_CODE (a) != RECORD_TYPE
814 || TREE_CODE (b) != RECORD_TYPE)
817 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
823 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
824 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
825 otherwise it must be exact. Exception lists are unordered, but
826 we've already filtered out duplicates. Most lists will be in order,
827 we should try to make use of that. */
830 comp_except_specs (tree t1, tree t2, bool exact)
839 if (t1 == NULL_TREE) /* T1 is ... */
840 return t2 == NULL_TREE || !exact;
841 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
842 return t2 != NULL_TREE && !TREE_VALUE (t2);
843 if (t2 == NULL_TREE) /* T2 is ... */
845 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
848 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
849 Count how many we find, to determine exactness. For exact matching and
850 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
852 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
854 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
856 tree a = TREE_VALUE (probe);
857 tree b = TREE_VALUE (t2);
859 if (comp_except_types (a, b, exact))
861 if (probe == base && exact)
862 base = TREE_CHAIN (probe);
867 if (probe == NULL_TREE)
870 return !exact || base == NULL_TREE || length == list_length (t1);
873 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
874 [] can match [size]. */
877 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
886 /* The type of the array elements must be the same. */
887 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
890 d1 = TYPE_DOMAIN (t1);
891 d2 = TYPE_DOMAIN (t2);
896 /* If one of the arrays is dimensionless, and the other has a
897 dimension, they are of different types. However, it is valid to
905 declarations for an array object can specify
906 array types that differ by the presence or absence of a major
907 array bound (_dcl.array_). */
909 return allow_redeclaration;
911 /* Check that the dimensions are the same. */
913 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
915 max1 = TYPE_MAX_VALUE (d1);
916 max2 = TYPE_MAX_VALUE (d2);
917 if (processing_template_decl && !abi_version_at_least (2)
918 && !value_dependent_expression_p (max1)
919 && !value_dependent_expression_p (max2))
921 /* With abi-1 we do not fold non-dependent array bounds, (and
922 consequently mangle them incorrectly). We must therefore
923 fold them here, to verify the domains have the same
929 if (!cp_tree_equal (max1, max2))
935 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
936 is a bitwise-or of the COMPARE_* flags. */
939 comptypes (tree t1, tree t2, int strict)
944 /* Suppress errors caused by previously reported errors. */
945 if (t1 == error_mark_node || t2 == error_mark_node)
948 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
950 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
951 current instantiation. */
952 if (TREE_CODE (t1) == TYPENAME_TYPE)
954 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
956 if (resolved != error_mark_node)
960 if (TREE_CODE (t2) == TYPENAME_TYPE)
962 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
964 if (resolved != error_mark_node)
968 /* If either type is the internal version of sizetype, use the
970 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
971 && TYPE_ORIG_SIZE_TYPE (t1))
972 t1 = TYPE_ORIG_SIZE_TYPE (t1);
974 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
975 && TYPE_ORIG_SIZE_TYPE (t2))
976 t2 = TYPE_ORIG_SIZE_TYPE (t2);
978 if (TYPE_PTRMEMFUNC_P (t1))
979 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
980 if (TYPE_PTRMEMFUNC_P (t2))
981 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
983 /* Different classes of types can't be compatible. */
984 if (TREE_CODE (t1) != TREE_CODE (t2))
987 /* Qualifiers must match. For array types, we will check when we
988 recur on the array element types. */
989 if (TREE_CODE (t1) != ARRAY_TYPE
990 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
992 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
995 /* Allow for two different type nodes which have essentially the same
996 definition. Note that we already checked for equality of the type
997 qualifiers (just above). */
999 if (TREE_CODE (t1) != ARRAY_TYPE
1000 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
1003 /* Compare the types. Break out if they could be the same. */
1004 switch (TREE_CODE (t1))
1006 case TEMPLATE_TEMPLATE_PARM:
1007 case BOUND_TEMPLATE_TEMPLATE_PARM:
1008 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1009 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1011 if (!comp_template_parms
1012 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1013 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1015 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1017 /* Don't check inheritance. */
1018 strict = COMPARE_STRICT;
1023 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1024 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1025 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1026 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1029 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1031 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1037 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1038 strict & ~COMPARE_REDECLARATION))
1040 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1045 case REFERENCE_TYPE:
1046 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1047 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1048 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1054 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1056 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1061 /* Target types must match incl. qualifiers. */
1062 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1066 case TEMPLATE_TYPE_PARM:
1067 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1068 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1073 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1074 TYPENAME_TYPE_FULLNAME (t2)))
1076 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1080 case UNBOUND_CLASS_TEMPLATE:
1081 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1083 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1088 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1093 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1094 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1102 /* If we get here, we know that from a target independent POV the
1103 types are the same. Make sure the target attributes are also
1105 return targetm.comp_type_attributes (t1, t2);
1108 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1111 at_least_as_qualified_p (tree type1, tree type2)
1113 int q1 = cp_type_quals (type1);
1114 int q2 = cp_type_quals (type2);
1116 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1117 return (q1 & q2) == q2;
1120 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1121 more cv-qualified that TYPE1, and 0 otherwise. */
1124 comp_cv_qualification (tree type1, tree type2)
1126 int q1 = cp_type_quals (type1);
1127 int q2 = cp_type_quals (type2);
1132 if ((q1 & q2) == q2)
1134 else if ((q1 & q2) == q1)
1140 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1141 subset of the cv-qualification signature of TYPE2, and the types
1142 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1145 comp_cv_qual_signature (tree type1, tree type2)
1147 if (comp_ptr_ttypes_real (type2, type1, -1))
1149 else if (comp_ptr_ttypes_real (type1, type2, -1))
1155 /* If two types share a common base type, return that basetype.
1156 If there is not a unique most-derived base type, this function
1157 returns ERROR_MARK_NODE. */
1160 common_base_type (tree tt1, tree tt2)
1162 tree best = NULL_TREE;
1165 /* If one is a baseclass of another, that's good enough. */
1166 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1168 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1171 /* Otherwise, try to find a unique baseclass of TT1
1172 that is shared by TT2, and follow that down. */
1173 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1175 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1176 tree trial = common_base_type (basetype, tt2);
1180 if (trial == error_mark_node)
1182 if (best == NULL_TREE)
1184 else if (best != trial)
1185 return error_mark_node;
1190 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1192 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1193 tree trial = common_base_type (tt1, basetype);
1197 if (trial == error_mark_node)
1199 if (best == NULL_TREE)
1201 else if (best != trial)
1202 return error_mark_node;
1208 /* Subroutines of `comptypes'. */
1210 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1211 equivalent in the sense that functions with those parameter types
1212 can have equivalent types. The two lists must be equivalent,
1213 element by element. */
1216 compparms (tree parms1, tree parms2)
1220 /* An unspecified parmlist matches any specified parmlist
1221 whose argument types don't need default promotions. */
1223 for (t1 = parms1, t2 = parms2;
1225 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1227 /* If one parmlist is shorter than the other,
1228 they fail to match. */
1231 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1238 /* Process a sizeof or alignof expression where the operand is a
1242 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1247 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1248 if (type == error_mark_node)
1249 return error_mark_node;
1251 type = non_reference (type);
1252 if (TREE_CODE (type) == METHOD_TYPE)
1254 if (complain && (pedantic || warn_pointer_arith))
1255 pedwarn ("invalid application of %qs to a member function",
1256 operator_name_info[(int) op].name);
1257 value = size_one_node;
1260 dependent_p = dependent_type_p (type);
1262 complete_type (type);
1264 /* VLA types will have a non-constant size. In the body of an
1265 uninstantiated template, we don't need to try to compute the
1266 value, because the sizeof expression is not an integral
1267 constant expression in that case. And, if we do try to
1268 compute the value, we'll likely end up with SAVE_EXPRs, which
1269 the template substitution machinery does not expect to see. */
1270 || (processing_template_decl
1271 && COMPLETE_TYPE_P (type)
1272 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1274 value = build_min (op, size_type_node, type);
1275 TREE_READONLY (value) = 1;
1279 return c_sizeof_or_alignof_type (complete_type (type),
1284 /* Process a sizeof expression where the operand is an expression. */
1287 cxx_sizeof_expr (tree e)
1289 if (e == error_mark_node)
1290 return error_mark_node;
1292 if (processing_template_decl)
1294 e = build_min (SIZEOF_EXPR, size_type_node, e);
1295 TREE_SIDE_EFFECTS (e) = 0;
1296 TREE_READONLY (e) = 1;
1301 if (TREE_CODE (e) == COMPONENT_REF
1302 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1303 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1305 error ("invalid application of %<sizeof%> to a bit-field");
1308 else if (is_overloaded_fn (e))
1310 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1314 else if (type_unknown_p (e))
1316 cxx_incomplete_type_error (e, TREE_TYPE (e));
1322 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1325 /* Implement the __alignof keyword: Return the minimum required
1326 alignment of E, measured in bytes. For VAR_DECL's and
1327 FIELD_DECL's return DECL_ALIGN (which can be set from an
1328 "aligned" __attribute__ specification). */
1331 cxx_alignof_expr (tree e)
1335 if (e == error_mark_node)
1336 return error_mark_node;
1338 if (processing_template_decl)
1340 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1341 TREE_SIDE_EFFECTS (e) = 0;
1342 TREE_READONLY (e) = 1;
1347 if (TREE_CODE (e) == VAR_DECL)
1348 t = size_int (DECL_ALIGN_UNIT (e));
1349 else if (TREE_CODE (e) == COMPONENT_REF
1350 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1351 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1353 error ("invalid application of %<__alignof%> to a bit-field");
1356 else if (TREE_CODE (e) == COMPONENT_REF
1357 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1358 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1359 else if (is_overloaded_fn (e))
1361 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1365 else if (type_unknown_p (e))
1367 cxx_incomplete_type_error (e, TREE_TYPE (e));
1371 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1373 return fold_convert (size_type_node, t);
1376 /* Process a sizeof or alignof expression E with code OP where the operand
1377 is an expression. */
1380 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1382 if (op == SIZEOF_EXPR)
1383 return cxx_sizeof_expr (e);
1385 return cxx_alignof_expr (e);
1388 /* EXPR is being used in a context that is not a function call.
1393 The expression can be used only as the left-hand operand of a
1394 member function call.
1396 [expr.mptr.operator]
1398 If the result of .* or ->* is a function, then that result can be
1399 used only as the operand for the function call operator ().
1401 by issuing an error message if appropriate. Returns true iff EXPR
1402 violates these rules. */
1405 invalid_nonstatic_memfn_p (tree expr)
1407 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1409 error ("invalid use of non-static member function");
1415 /* If EXP is a reference to a bitfield, and the type of EXP does not
1416 match the declared type of the bitfield, return the declared type
1417 of the bitfield. Otherwise, return NULL_TREE. */
1420 is_bitfield_expr_with_lowered_type (tree exp)
1422 switch (TREE_CODE (exp))
1425 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1427 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1430 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1434 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1440 field = TREE_OPERAND (exp, 1);
1441 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1443 if (same_type_ignoring_top_level_qualifiers_p
1444 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1446 return DECL_BIT_FIELD_TYPE (field);
1454 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1455 bitfield with a lowered type, the type of EXP is returned, rather
1459 unlowered_expr_type (tree exp)
1463 type = is_bitfield_expr_with_lowered_type (exp);
1465 type = TREE_TYPE (exp);
1470 /* Perform the conversions in [expr] that apply when an lvalue appears
1471 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1472 function-to-pointer conversions. In addition, manifest constants
1473 are replaced by their values, and bitfield references are converted
1474 to their declared types.
1476 Although the returned value is being used as an rvalue, this
1477 function does not wrap the returned expression in a
1478 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1479 that the return value is no longer an lvalue. */
1482 decay_conversion (tree exp)
1485 enum tree_code code;
1487 type = TREE_TYPE (exp);
1488 if (type == error_mark_node)
1489 return error_mark_node;
1491 if (type_unknown_p (exp))
1493 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1494 return error_mark_node;
1497 exp = decl_constant_value (exp);
1498 if (error_operand_p (exp))
1499 return error_mark_node;
1501 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1502 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1503 code = TREE_CODE (type);
1504 if (code == VOID_TYPE)
1506 error ("void value not ignored as it ought to be");
1507 return error_mark_node;
1509 if (invalid_nonstatic_memfn_p (exp))
1510 return error_mark_node;
1511 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1512 return build_unary_op (ADDR_EXPR, exp, 0);
1513 if (code == ARRAY_TYPE)
1518 if (TREE_CODE (exp) == INDIRECT_REF)
1519 return build_nop (build_pointer_type (TREE_TYPE (type)),
1520 TREE_OPERAND (exp, 0));
1522 if (TREE_CODE (exp) == COMPOUND_EXPR)
1524 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1525 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1526 TREE_OPERAND (exp, 0), op1);
1530 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1532 error ("invalid use of non-lvalue array");
1533 return error_mark_node;
1536 ptrtype = build_pointer_type (TREE_TYPE (type));
1538 if (TREE_CODE (exp) == VAR_DECL)
1540 if (!cxx_mark_addressable (exp))
1541 return error_mark_node;
1542 adr = build_nop (ptrtype, build_address (exp));
1545 /* This way is better for a COMPONENT_REF since it can
1546 simplify the offset for a component. */
1547 adr = build_unary_op (ADDR_EXPR, exp, 1);
1548 return cp_convert (ptrtype, adr);
1551 /* If a bitfield is used in a context where integral promotion
1552 applies, then the caller is expected to have used
1553 default_conversion. That function promotes bitfields correctly
1554 before calling this function. At this point, if we have a
1555 bitfield referenced, we may assume that is not subject to
1556 promotion, and that, therefore, the type of the resulting rvalue
1557 is the declared type of the bitfield. */
1558 exp = convert_bitfield_to_declared_type (exp);
1560 /* We do not call rvalue() here because we do not want to wrap EXP
1561 in a NON_LVALUE_EXPR. */
1565 Non-class rvalues always have cv-unqualified types. */
1566 type = TREE_TYPE (exp);
1567 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1568 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1573 /* Perform prepatory conversions, as part of the "usual arithmetic
1574 conversions". In particular, as per [expr]:
1576 Whenever an lvalue expression appears as an operand of an
1577 operator that expects the rvalue for that operand, the
1578 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1579 standard conversions are applied to convert the expression to an
1582 In addition, we perform integral promotions here, as those are
1583 applied to both operands to a binary operator before determining
1584 what additional conversions should apply. */
1587 default_conversion (tree exp)
1589 /* Perform the integral promotions first so that bitfield
1590 expressions (which may promote to "int", even if the bitfield is
1591 declared "unsigned") are promoted correctly. */
1592 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1593 exp = perform_integral_promotions (exp);
1594 /* Perform the other conversions. */
1595 exp = decay_conversion (exp);
1600 /* EXPR is an expression with an integral or enumeration type.
1601 Perform the integral promotions in [conv.prom], and return the
1605 perform_integral_promotions (tree expr)
1612 If the bitfield has an enumerated type, it is treated as any
1613 other value of that type for promotion purposes. */
1614 type = is_bitfield_expr_with_lowered_type (expr);
1615 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1616 type = TREE_TYPE (expr);
1617 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1618 promoted_type = type_promotes_to (type);
1619 if (type != promoted_type)
1620 expr = cp_convert (promoted_type, expr);
1624 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1628 inline_conversion (tree exp)
1630 if (TREE_CODE (exp) == FUNCTION_DECL)
1631 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1636 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1637 decay_conversion to one. */
1640 string_conv_p (tree totype, tree exp, int warn)
1644 if (TREE_CODE (totype) != POINTER_TYPE)
1647 t = TREE_TYPE (totype);
1648 if (!same_type_p (t, char_type_node)
1649 && !same_type_p (t, wchar_type_node))
1652 if (TREE_CODE (exp) == STRING_CST)
1654 /* Make sure that we don't try to convert between char and wchar_t. */
1655 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1660 /* Is this a string constant which has decayed to 'const char *'? */
1661 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1662 if (!same_type_p (TREE_TYPE (exp), t))
1665 if (TREE_CODE (exp) != ADDR_EXPR
1666 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1670 /* This warning is not very useful, as it complains about printf. */
1672 warning (OPT_Wwrite_strings,
1673 "deprecated conversion from string constant to %qT",
1679 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1680 can, for example, use as an lvalue. This code used to be in
1681 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1682 expressions, where we're dealing with aggregates. But now it's again only
1683 called from unary_complex_lvalue. The case (in particular) that led to
1684 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1688 rationalize_conditional_expr (enum tree_code code, tree t)
1690 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1691 the first operand is always the one to be used if both operands
1692 are equal, so we know what conditional expression this used to be. */
1693 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1695 /* The following code is incorrect if either operand side-effects. */
1696 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1697 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1699 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1700 ? LE_EXPR : GE_EXPR),
1701 TREE_OPERAND (t, 0),
1702 TREE_OPERAND (t, 1),
1703 /*overloaded_p=*/NULL),
1704 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1705 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1709 build_conditional_expr (TREE_OPERAND (t, 0),
1710 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1711 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1714 /* Given the TYPE of an anonymous union field inside T, return the
1715 FIELD_DECL for the field. If not found return NULL_TREE. Because
1716 anonymous unions can nest, we must also search all anonymous unions
1717 that are directly reachable. */
1720 lookup_anon_field (tree t, tree type)
1724 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1726 if (TREE_STATIC (field))
1728 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1731 /* If we find it directly, return the field. */
1732 if (DECL_NAME (field) == NULL_TREE
1733 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1738 /* Otherwise, it could be nested, search harder. */
1739 if (DECL_NAME (field) == NULL_TREE
1740 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1742 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1750 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1751 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1752 non-NULL, it indicates the path to the base used to name MEMBER.
1753 If PRESERVE_REFERENCE is true, the expression returned will have
1754 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1755 returned will have the type referred to by the reference.
1757 This function does not perform access control; that is either done
1758 earlier by the parser when the name of MEMBER is resolved to MEMBER
1759 itself, or later when overload resolution selects one of the
1760 functions indicated by MEMBER. */
1763 build_class_member_access_expr (tree object, tree member,
1764 tree access_path, bool preserve_reference)
1768 tree result = NULL_TREE;
1770 if (error_operand_p (object) || error_operand_p (member))
1771 return error_mark_node;
1773 gcc_assert (DECL_P (member) || BASELINK_P (member));
1777 The type of the first expression shall be "class object" (of a
1779 object_type = TREE_TYPE (object);
1780 if (!currently_open_class (object_type)
1781 && !complete_type_or_else (object_type, object))
1782 return error_mark_node;
1783 if (!CLASS_TYPE_P (object_type))
1785 error ("request for member %qD in %qE, which is of non-class type %qT",
1786 member, object, object_type);
1787 return error_mark_node;
1790 /* The standard does not seem to actually say that MEMBER must be a
1791 member of OBJECT_TYPE. However, that is clearly what is
1793 if (DECL_P (member))
1795 member_scope = DECL_CLASS_CONTEXT (member);
1797 if (TREE_DEPRECATED (member))
1798 warn_deprecated_use (member);
1801 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1802 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1803 presently be the anonymous union. Go outwards until we find a
1804 type related to OBJECT_TYPE. */
1805 while (ANON_AGGR_TYPE_P (member_scope)
1806 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1808 member_scope = TYPE_CONTEXT (member_scope);
1809 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1811 if (TREE_CODE (member) == FIELD_DECL)
1812 error ("invalid use of nonstatic data member %qE", member);
1814 error ("%qD is not a member of %qT", member, object_type);
1815 return error_mark_node;
1818 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1819 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1820 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1822 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1824 object = build_indirect_ref (temp, NULL);
1827 /* In [expr.ref], there is an explicit list of the valid choices for
1828 MEMBER. We check for each of those cases here. */
1829 if (TREE_CODE (member) == VAR_DECL)
1831 /* A static data member. */
1833 /* If OBJECT has side-effects, they are supposed to occur. */
1834 if (TREE_SIDE_EFFECTS (object))
1835 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1837 else if (TREE_CODE (member) == FIELD_DECL)
1839 /* A non-static data member. */
1844 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1845 && integer_zerop (TREE_OPERAND (object, 0)));
1847 /* Convert OBJECT to the type of MEMBER. */
1848 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1849 TYPE_MAIN_VARIANT (member_scope)))
1854 binfo = lookup_base (access_path ? access_path : object_type,
1855 member_scope, ba_unique, &kind);
1856 if (binfo == error_mark_node)
1857 return error_mark_node;
1859 /* It is invalid to try to get to a virtual base of a
1860 NULL object. The most common cause is invalid use of
1862 if (null_object_p && kind == bk_via_virtual)
1864 error ("invalid access to non-static data member %qD of "
1867 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1868 return error_mark_node;
1871 /* Convert to the base. */
1872 object = build_base_path (PLUS_EXPR, object, binfo,
1874 /* If we found the base successfully then we should be able
1875 to convert to it successfully. */
1876 gcc_assert (object != error_mark_node);
1879 /* Complain about other invalid uses of offsetof, even though they will
1880 give the right answer. Note that we complain whether or not they
1881 actually used the offsetof macro, since there's no way to know at this
1882 point. So we just give a warning, instead of a pedwarn. */
1883 /* Do not produce this warning for base class field references, because
1884 we know for a fact that didn't come from offsetof. This does occur
1885 in various testsuite cases where a null object is passed where a
1886 vtable access is required. */
1887 if (null_object_p && warn_invalid_offsetof
1888 && CLASSTYPE_NON_POD_P (object_type)
1889 && !DECL_FIELD_IS_BASE (member)
1890 && !skip_evaluation)
1892 warning (0, "invalid access to non-static data member %qD of NULL object",
1894 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1897 /* If MEMBER is from an anonymous aggregate, we have converted
1898 OBJECT so that it refers to the class containing the
1899 anonymous union. Generate a reference to the anonymous union
1900 itself, and recur to find MEMBER. */
1901 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1902 /* When this code is called from build_field_call, the
1903 object already has the type of the anonymous union.
1904 That is because the COMPONENT_REF was already
1905 constructed, and was then disassembled before calling
1906 build_field_call. After the function-call code is
1907 cleaned up, this waste can be eliminated. */
1908 && (!same_type_ignoring_top_level_qualifiers_p
1909 (TREE_TYPE (object), DECL_CONTEXT (member))))
1911 tree anonymous_union;
1913 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1914 DECL_CONTEXT (member));
1915 object = build_class_member_access_expr (object,
1917 /*access_path=*/NULL_TREE,
1918 preserve_reference);
1921 /* Compute the type of the field, as described in [expr.ref]. */
1922 type_quals = TYPE_UNQUALIFIED;
1923 member_type = TREE_TYPE (member);
1924 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1926 type_quals = (cp_type_quals (member_type)
1927 | cp_type_quals (object_type));
1929 /* A field is const (volatile) if the enclosing object, or the
1930 field itself, is const (volatile). But, a mutable field is
1931 not const, even within a const object. */
1932 if (DECL_MUTABLE_P (member))
1933 type_quals &= ~TYPE_QUAL_CONST;
1934 member_type = cp_build_qualified_type (member_type, type_quals);
1937 result = build3 (COMPONENT_REF, member_type, object, member,
1939 result = fold_if_not_in_template (result);
1941 /* Mark the expression const or volatile, as appropriate. Even
1942 though we've dealt with the type above, we still have to mark the
1943 expression itself. */
1944 if (type_quals & TYPE_QUAL_CONST)
1945 TREE_READONLY (result) = 1;
1946 if (type_quals & TYPE_QUAL_VOLATILE)
1947 TREE_THIS_VOLATILE (result) = 1;
1949 else if (BASELINK_P (member))
1951 /* The member is a (possibly overloaded) member function. */
1955 /* If the MEMBER is exactly one static member function, then we
1956 know the type of the expression. Otherwise, we must wait
1957 until overload resolution has been performed. */
1958 functions = BASELINK_FUNCTIONS (member);
1959 if (TREE_CODE (functions) == FUNCTION_DECL
1960 && DECL_STATIC_FUNCTION_P (functions))
1961 type = TREE_TYPE (functions);
1963 type = unknown_type_node;
1964 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1965 base. That will happen when the function is called. */
1966 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1968 else if (TREE_CODE (member) == CONST_DECL)
1970 /* The member is an enumerator. */
1972 /* If OBJECT has side-effects, they are supposed to occur. */
1973 if (TREE_SIDE_EFFECTS (object))
1974 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1979 error ("invalid use of %qD", member);
1980 return error_mark_node;
1983 if (!preserve_reference)
1986 If E2 is declared to have type "reference to T", then ... the
1987 type of E1.E2 is T. */
1988 result = convert_from_reference (result);
1993 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1994 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1997 lookup_destructor (tree object, tree scope, tree dtor_name)
1999 tree object_type = TREE_TYPE (object);
2000 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2003 if (scope && !check_dtor_name (scope, dtor_type))
2005 error ("qualified type %qT does not match destructor name ~%qT",
2007 return error_mark_node;
2009 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2011 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2012 TYPE_MAIN_VARIANT (object_type), dtor_type);
2013 return error_mark_node;
2015 expr = lookup_member (dtor_type, complete_dtor_identifier,
2016 /*protect=*/1, /*want_type=*/false);
2017 expr = (adjust_result_of_qualified_name_lookup
2018 (expr, dtor_type, object_type));
2022 /* An expression of the form "A::template B" has been resolved to
2023 DECL. Issue a diagnostic if B is not a template or template
2027 check_template_keyword (tree decl)
2029 /* The standard says:
2033 If a name prefixed by the keyword template is not a member
2034 template, the program is ill-formed.
2036 DR 228 removed the restriction that the template be a member
2039 DR 96, if accepted would add the further restriction that explicit
2040 template arguments must be provided if the template keyword is
2041 used, but, as of 2005-10-16, that DR is still in "drafting". If
2042 this DR is accepted, then the semantic checks here can be
2043 simplified, as the entity named must in fact be a template
2044 specialization, rather than, as at present, a set of overloaded
2045 functions containing at least one template function. */
2046 if (TREE_CODE (decl) != TEMPLATE_DECL
2047 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2049 if (!is_overloaded_fn (decl))
2050 pedwarn ("%qD is not a template", decl);
2055 if (BASELINK_P (fns))
2056 fns = BASELINK_FUNCTIONS (fns);
2059 tree fn = OVL_CURRENT (fns);
2060 if (TREE_CODE (fn) == TEMPLATE_DECL
2061 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2063 if (TREE_CODE (fn) == FUNCTION_DECL
2064 && DECL_USE_TEMPLATE (fn)
2065 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2067 fns = OVL_NEXT (fns);
2070 pedwarn ("%qD is not a template", decl);
2075 /* This function is called by the parser to process a class member
2076 access expression of the form OBJECT.NAME. NAME is a node used by
2077 the parser to represent a name; it is not yet a DECL. It may,
2078 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2079 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2080 there is no reason to do the lookup twice, so the parser keeps the
2081 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2082 be a template via the use of the "A::template B" syntax. */
2085 finish_class_member_access_expr (tree object, tree name, bool template_p)
2090 tree access_path = NULL_TREE;
2091 tree orig_object = object;
2092 tree orig_name = name;
2094 if (object == error_mark_node || name == error_mark_node)
2095 return error_mark_node;
2097 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2098 if (!objc_is_public (object, name))
2099 return error_mark_node;
2101 object_type = TREE_TYPE (object);
2103 if (processing_template_decl)
2105 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2106 dependent_type_p (object_type)
2107 /* If NAME is just an IDENTIFIER_NODE, then the expression
2109 || TREE_CODE (object) == IDENTIFIER_NODE
2110 /* If NAME is "f<args>", where either 'f' or 'args' is
2111 dependent, then the expression is dependent. */
2112 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2113 && dependent_template_id_p (TREE_OPERAND (name, 0),
2114 TREE_OPERAND (name, 1)))
2115 /* If NAME is "T::X" where "T" is dependent, then the
2116 expression is dependent. */
2117 || (TREE_CODE (name) == SCOPE_REF
2118 && TYPE_P (TREE_OPERAND (name, 0))
2119 && dependent_type_p (TREE_OPERAND (name, 0))))
2120 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2121 object = build_non_dependent_expr (object);
2126 The type of the first expression shall be "class object" (of a
2128 if (!currently_open_class (object_type)
2129 && !complete_type_or_else (object_type, object))
2130 return error_mark_node;
2131 if (!CLASS_TYPE_P (object_type))
2133 error ("request for member %qD in %qE, which is of non-class type %qT",
2134 name, object, object_type);
2135 return error_mark_node;
2138 if (BASELINK_P (name))
2139 /* A member function that has already been looked up. */
2143 bool is_template_id = false;
2144 tree template_args = NULL_TREE;
2147 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2149 is_template_id = true;
2150 template_args = TREE_OPERAND (name, 1);
2151 name = TREE_OPERAND (name, 0);
2153 if (TREE_CODE (name) == OVERLOAD)
2154 name = DECL_NAME (get_first_fn (name));
2155 else if (DECL_P (name))
2156 name = DECL_NAME (name);
2159 if (TREE_CODE (name) == SCOPE_REF)
2161 /* A qualified name. The qualifying class or namespace `S'
2162 has already been looked up; it is either a TYPE or a
2164 scope = TREE_OPERAND (name, 0);
2165 name = TREE_OPERAND (name, 1);
2167 /* If SCOPE is a namespace, then the qualified name does not
2168 name a member of OBJECT_TYPE. */
2169 if (TREE_CODE (scope) == NAMESPACE_DECL)
2171 error ("%<%D::%D%> is not a member of %qT",
2172 scope, name, object_type);
2173 return error_mark_node;
2176 gcc_assert (CLASS_TYPE_P (scope));
2177 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2178 || TREE_CODE (name) == BIT_NOT_EXPR);
2180 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2181 access_path = lookup_base (object_type, scope, ba_check, NULL);
2182 if (access_path == error_mark_node)
2183 return error_mark_node;
2186 error ("%qT is not a base of %qT", scope, object_type);
2187 return error_mark_node;
2193 access_path = object_type;
2196 if (TREE_CODE (name) == BIT_NOT_EXPR)
2197 member = lookup_destructor (object, scope, name);
2200 /* Look up the member. */
2201 member = lookup_member (access_path, name, /*protect=*/1,
2202 /*want_type=*/false);
2203 if (member == NULL_TREE)
2205 error ("%qD has no member named %qE", object_type, name);
2206 return error_mark_node;
2208 if (member == error_mark_node)
2209 return error_mark_node;
2214 tree template = member;
2216 if (BASELINK_P (template))
2217 template = lookup_template_function (template, template_args);
2220 error ("%qD is not a member template function", name);
2221 return error_mark_node;
2226 if (TREE_DEPRECATED (member))
2227 warn_deprecated_use (member);
2230 check_template_keyword (member);
2232 expr = build_class_member_access_expr (object, member, access_path,
2233 /*preserve_reference=*/false);
2234 if (processing_template_decl && expr != error_mark_node)
2236 if (BASELINK_P (member))
2238 if (TREE_CODE (orig_name) == SCOPE_REF)
2239 BASELINK_QUALIFIED_P (member) = 1;
2242 return build_min_non_dep (COMPONENT_REF, expr,
2243 orig_object, orig_name,
2250 /* Return an expression for the MEMBER_NAME field in the internal
2251 representation of PTRMEM, a pointer-to-member function. (Each
2252 pointer-to-member function type gets its own RECORD_TYPE so it is
2253 more convenient to access the fields by name than by FIELD_DECL.)
2254 This routine converts the NAME to a FIELD_DECL and then creates the
2255 node for the complete expression. */
2258 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2264 /* This code is a stripped down version of
2265 build_class_member_access_expr. It does not work to use that
2266 routine directly because it expects the object to be of class
2268 ptrmem_type = TREE_TYPE (ptrmem);
2269 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2270 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2271 /*want_type=*/false);
2272 member_type = cp_build_qualified_type (TREE_TYPE (member),
2273 cp_type_quals (ptrmem_type));
2274 return fold_build3 (COMPONENT_REF, member_type,
2275 ptrmem, member, NULL_TREE);
2278 /* Given an expression PTR for a pointer, return an expression
2279 for the value pointed to.
2280 ERRORSTRING is the name of the operator to appear in error messages.
2282 This function may need to overload OPERATOR_FNNAME.
2283 Must also handle REFERENCE_TYPEs for C++. */
2286 build_x_indirect_ref (tree expr, const char *errorstring)
2288 tree orig_expr = expr;
2291 if (processing_template_decl)
2293 if (type_dependent_expression_p (expr))
2294 return build_min_nt (INDIRECT_REF, expr);
2295 expr = build_non_dependent_expr (expr);
2298 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2299 NULL_TREE, /*overloaded_p=*/NULL);
2301 rval = build_indirect_ref (expr, errorstring);
2303 if (processing_template_decl && rval != error_mark_node)
2304 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2310 build_indirect_ref (tree ptr, const char *errorstring)
2314 if (ptr == error_mark_node)
2315 return error_mark_node;
2317 if (ptr == current_class_ptr)
2318 return current_class_ref;
2320 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2321 ? ptr : decay_conversion (ptr));
2322 type = TREE_TYPE (pointer);
2324 if (POINTER_TYPE_P (type))
2328 If the type of the expression is "pointer to T," the type
2329 of the result is "T."
2331 We must use the canonical variant because certain parts of
2332 the back end, like fold, do pointer comparisons between
2334 tree t = canonical_type_variant (TREE_TYPE (type));
2336 if (VOID_TYPE_P (t))
2338 /* A pointer to incomplete type (other than cv void) can be
2339 dereferenced [expr.unary.op]/1 */
2340 error ("%qT is not a pointer-to-object type", type);
2341 return error_mark_node;
2343 else if (TREE_CODE (pointer) == ADDR_EXPR
2344 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2345 /* The POINTER was something like `&x'. We simplify `*&x' to
2347 return TREE_OPERAND (pointer, 0);
2350 tree ref = build1 (INDIRECT_REF, t, pointer);
2352 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2353 so that we get the proper error message if the result is used
2354 to assign to. Also, &* is supposed to be a no-op. */
2355 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2356 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2357 TREE_SIDE_EFFECTS (ref)
2358 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2362 /* `pointer' won't be an error_mark_node if we were given a
2363 pointer to member, so it's cool to check for this here. */
2364 else if (TYPE_PTR_TO_MEMBER_P (type))
2365 error ("invalid use of %qs on pointer to member", errorstring);
2366 else if (pointer != error_mark_node)
2369 error ("invalid type argument of %qs", errorstring);
2371 error ("invalid type argument");
2373 return error_mark_node;
2376 /* This handles expressions of the form "a[i]", which denotes
2379 This is logically equivalent in C to *(a+i), but we may do it differently.
2380 If A is a variable or a member, we generate a primitive ARRAY_REF.
2381 This avoids forcing the array out of registers, and can work on
2382 arrays that are not lvalues (for example, members of structures returned
2385 If INDEX is of some user-defined type, it must be converted to
2386 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2387 will inherit the type of the array, which will be some pointer type. */
2390 build_array_ref (tree array, tree idx)
2394 error ("subscript missing in array reference");
2395 return error_mark_node;
2398 if (TREE_TYPE (array) == error_mark_node
2399 || TREE_TYPE (idx) == error_mark_node)
2400 return error_mark_node;
2402 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2404 switch (TREE_CODE (array))
2408 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2409 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2410 TREE_OPERAND (array, 0), value);
2414 return build_conditional_expr
2415 (TREE_OPERAND (array, 0),
2416 build_array_ref (TREE_OPERAND (array, 1), idx),
2417 build_array_ref (TREE_OPERAND (array, 2), idx));
2423 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2427 warn_array_subscript_with_type_char (idx);
2429 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2431 error ("array subscript is not an integer");
2432 return error_mark_node;
2435 /* Apply integral promotions *after* noticing character types.
2436 (It is unclear why we do these promotions -- the standard
2437 does not say that we should. In fact, the natural thing would
2438 seem to be to convert IDX to ptrdiff_t; we're performing
2439 pointer arithmetic.) */
2440 idx = perform_integral_promotions (idx);
2442 /* An array that is indexed by a non-constant
2443 cannot be stored in a register; we must be able to do
2444 address arithmetic on its address.
2445 Likewise an array of elements of variable size. */
2446 if (TREE_CODE (idx) != INTEGER_CST
2447 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2448 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2451 if (!cxx_mark_addressable (array))
2452 return error_mark_node;
2455 /* An array that is indexed by a constant value which is not within
2456 the array bounds cannot be stored in a register either; because we
2457 would get a crash in store_bit_field/extract_bit_field when trying
2458 to access a non-existent part of the register. */
2459 if (TREE_CODE (idx) == INTEGER_CST
2460 && TYPE_DOMAIN (TREE_TYPE (array))
2461 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2463 if (!cxx_mark_addressable (array))
2464 return error_mark_node;
2467 if (pedantic && !lvalue_p (array))
2468 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2470 /* Note in C++ it is valid to subscript a `register' array, since
2471 it is valid to take the address of something with that
2472 storage specification. */
2476 while (TREE_CODE (foo) == COMPONENT_REF)
2477 foo = TREE_OPERAND (foo, 0);
2478 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2479 warning (OPT_Wextra, "subscripting array declared %<register%>");
2482 type = TREE_TYPE (TREE_TYPE (array));
2483 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2484 /* Array ref is const/volatile if the array elements are
2485 or if the array is.. */
2486 TREE_READONLY (rval)
2487 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2488 TREE_SIDE_EFFECTS (rval)
2489 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2490 TREE_THIS_VOLATILE (rval)
2491 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2492 return require_complete_type (fold_if_not_in_template (rval));
2496 tree ar = default_conversion (array);
2497 tree ind = default_conversion (idx);
2499 /* Put the integer in IND to simplify error checking. */
2500 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2507 if (ar == error_mark_node)
2510 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2512 error ("subscripted value is neither array nor pointer");
2513 return error_mark_node;
2515 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2517 error ("array subscript is not an integer");
2518 return error_mark_node;
2521 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2526 /* Resolve a pointer to member function. INSTANCE is the object
2527 instance to use, if the member points to a virtual member.
2529 This used to avoid checking for virtual functions if basetype
2530 has no virtual functions, according to an earlier ANSI draft.
2531 With the final ISO C++ rules, such an optimization is
2532 incorrect: A pointer to a derived member can be static_cast
2533 to pointer-to-base-member, as long as the dynamic object
2534 later has the right member. */
2537 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2539 if (TREE_CODE (function) == OFFSET_REF)
2540 function = TREE_OPERAND (function, 1);
2542 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2544 tree idx, delta, e1, e2, e3, vtbl, basetype;
2545 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2547 tree instance_ptr = *instance_ptrptr;
2548 tree instance_save_expr = 0;
2549 if (instance_ptr == error_mark_node)
2551 if (TREE_CODE (function) == PTRMEM_CST)
2553 /* Extracting the function address from a pmf is only
2554 allowed with -Wno-pmf-conversions. It only works for
2556 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2557 e1 = convert (fntype, e1);
2562 error ("object missing in use of %qE", function);
2563 return error_mark_node;
2567 if (TREE_SIDE_EFFECTS (instance_ptr))
2568 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2570 if (TREE_SIDE_EFFECTS (function))
2571 function = save_expr (function);
2573 /* Start by extracting all the information from the PMF itself. */
2574 e3 = pfn_from_ptrmemfunc (function);
2575 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2576 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2577 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2579 case ptrmemfunc_vbit_in_pfn:
2580 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2581 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2584 case ptrmemfunc_vbit_in_delta:
2585 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2586 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2593 /* Convert down to the right base before using the instance. A
2594 special case is that in a pointer to member of class C, C may
2595 be incomplete. In that case, the function will of course be
2596 a member of C, and no conversion is required. In fact,
2597 lookup_base will fail in that case, because incomplete
2598 classes do not have BINFOs. */
2599 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2600 if (!same_type_ignoring_top_level_qualifiers_p
2601 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2603 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2604 basetype, ba_check, NULL);
2605 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2607 if (instance_ptr == error_mark_node)
2608 return error_mark_node;
2610 /* ...and then the delta in the PMF. */
2611 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2612 instance_ptr, delta);
2614 /* Hand back the adjusted 'this' argument to our caller. */
2615 *instance_ptrptr = instance_ptr;
2617 /* Next extract the vtable pointer from the object. */
2618 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2620 vtbl = build_indirect_ref (vtbl, NULL);
2622 /* Finally, extract the function pointer from the vtable. */
2623 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2624 e2 = build_indirect_ref (e2, NULL);
2625 TREE_CONSTANT (e2) = 1;
2626 TREE_INVARIANT (e2) = 1;
2628 /* When using function descriptors, the address of the
2629 vtable entry is treated as a function pointer. */
2630 if (TARGET_VTABLE_USES_DESCRIPTORS)
2631 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2632 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2634 TREE_TYPE (e2) = TREE_TYPE (e3);
2635 e1 = build_conditional_expr (e1, e2, e3);
2637 /* Make sure this doesn't get evaluated first inside one of the
2638 branches of the COND_EXPR. */
2639 if (instance_save_expr)
2640 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2641 instance_save_expr, e1);
2649 build_function_call (tree function, tree params)
2651 tree fntype, fndecl;
2652 tree coerced_params;
2653 tree name = NULL_TREE;
2655 tree original = function;
2657 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2658 expressions, like those used for ObjC messenger dispatches. */
2659 function = objc_rewrite_function_call (function, params);
2661 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2662 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2663 if (TREE_CODE (function) == NOP_EXPR
2664 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2665 function = TREE_OPERAND (function, 0);
2667 if (TREE_CODE (function) == FUNCTION_DECL)
2669 name = DECL_NAME (function);
2671 mark_used (function);
2674 /* Convert anything with function type to a pointer-to-function. */
2675 if (pedantic && DECL_MAIN_P (function))
2676 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2678 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2679 (because calling an inline function does not mean the function
2680 needs to be separately compiled). */
2682 if (DECL_INLINE (function))
2683 function = inline_conversion (function);
2685 function = build_addr_func (function);
2691 function = build_addr_func (function);
2694 if (function == error_mark_node)
2695 return error_mark_node;
2697 fntype = TREE_TYPE (function);
2699 if (TYPE_PTRMEMFUNC_P (fntype))
2701 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2702 "function in %<%E (...)%>",
2704 return error_mark_node;
2707 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2708 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2710 if (!((TREE_CODE (fntype) == POINTER_TYPE
2711 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2713 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2715 error ("%qE cannot be used as a function", original);
2716 return error_mark_node;
2719 /* fntype now gets the type of function pointed to. */
2720 fntype = TREE_TYPE (fntype);
2722 /* Convert the parameters to the types declared in the
2723 function prototype, or apply default promotions. */
2725 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2726 params, fndecl, LOOKUP_NORMAL);
2727 if (coerced_params == error_mark_node)
2728 return error_mark_node;
2730 /* Check for errors in format strings and inappropriately
2733 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2734 TYPE_ARG_TYPES (fntype));
2736 return build_cxx_call (function, coerced_params);
2739 /* Convert the actual parameter expressions in the list VALUES
2740 to the types in the list TYPELIST.
2741 If parmdecls is exhausted, or when an element has NULL as its type,
2742 perform the default conversions.
2744 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2746 This is also where warnings about wrong number of args are generated.
2748 Return a list of expressions for the parameters as converted.
2750 Both VALUES and the returned value are chains of TREE_LIST nodes
2751 with the elements of the list in the TREE_VALUE slots of those nodes.
2753 In C++, unspecified trailing parameters can be filled in with their
2754 default arguments, if such were specified. Do so here. */
2757 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2759 tree typetail, valtail;
2760 tree result = NULL_TREE;
2761 const char *called_thing = 0;
2764 /* Argument passing is always copy-initialization. */
2765 flags |= LOOKUP_ONLYCONVERTING;
2769 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2771 if (DECL_NAME (fndecl) == NULL_TREE
2772 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2773 called_thing = "constructor";
2775 called_thing = "member function";
2778 called_thing = "function";
2781 for (valtail = values, typetail = typelist;
2783 valtail = TREE_CHAIN (valtail), i++)
2785 tree type = typetail ? TREE_VALUE (typetail) : 0;
2786 tree val = TREE_VALUE (valtail);
2788 if (val == error_mark_node || type == error_mark_node)
2789 return error_mark_node;
2791 if (type == void_type_node)
2795 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2796 error ("at this point in file");
2799 error ("too many arguments to function");
2800 /* In case anybody wants to know if this argument
2803 TREE_TYPE (tree_last (result)) = error_mark_node;
2807 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2808 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2809 if (TREE_CODE (val) == NOP_EXPR
2810 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2811 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2812 val = TREE_OPERAND (val, 0);
2814 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2816 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2817 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2818 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2819 val = decay_conversion (val);
2822 if (val == error_mark_node)
2823 return error_mark_node;
2827 /* Formal parm type is specified by a function prototype. */
2830 if (!COMPLETE_TYPE_P (complete_type (type)))
2833 error ("parameter %P of %qD has incomplete type %qT",
2836 error ("parameter %P has incomplete type %qT", i, type);
2837 parmval = error_mark_node;
2841 parmval = convert_for_initialization
2842 (NULL_TREE, type, val, flags,
2843 "argument passing", fndecl, i);
2844 parmval = convert_for_arg_passing (type, parmval);
2847 if (parmval == error_mark_node)
2848 return error_mark_node;
2850 result = tree_cons (NULL_TREE, parmval, result);
2854 if (fndecl && DECL_BUILT_IN (fndecl)
2855 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2856 /* Don't do ellipsis conversion for __built_in_constant_p
2857 as this will result in spurious warnings for non-POD
2859 val = require_complete_type (val);
2861 val = convert_arg_to_ellipsis (val);
2863 result = tree_cons (NULL_TREE, val, result);
2867 typetail = TREE_CHAIN (typetail);
2870 if (typetail != 0 && typetail != void_list_node)
2872 /* See if there are default arguments that can be used. */
2873 if (TREE_PURPOSE (typetail)
2874 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2876 for (; typetail != void_list_node; ++i)
2879 = convert_default_arg (TREE_VALUE (typetail),
2880 TREE_PURPOSE (typetail),
2883 if (parmval == error_mark_node)
2884 return error_mark_node;
2886 result = tree_cons (0, parmval, result);
2887 typetail = TREE_CHAIN (typetail);
2888 /* ends with `...'. */
2889 if (typetail == NULL_TREE)
2897 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2898 error ("at this point in file");
2901 error ("too few arguments to function");
2902 return error_mark_node;
2906 return nreverse (result);
2909 /* Build a binary-operation expression, after performing default
2910 conversions on the operands. CODE is the kind of expression to build. */
2913 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2923 if (processing_template_decl)
2925 if (type_dependent_expression_p (arg1)
2926 || type_dependent_expression_p (arg2))
2927 return build_min_nt (code, arg1, arg2);
2928 arg1 = build_non_dependent_expr (arg1);
2929 arg2 = build_non_dependent_expr (arg2);
2932 if (code == DOTSTAR_EXPR)
2933 expr = build_m_component_ref (arg1, arg2);
2935 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2938 if (processing_template_decl && expr != error_mark_node)
2939 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2944 /* Build a binary-operation expression without default conversions.
2945 CODE is the kind of expression to build.
2946 This function differs from `build' in several ways:
2947 the data type of the result is computed and recorded in it,
2948 warnings are generated if arg data types are invalid,
2949 special handling for addition and subtraction of pointers is known,
2950 and some optimization is done (operations on narrow ints
2951 are done in the narrower type when that gives the same result).
2952 Constant folding is also done before the result is returned.
2954 Note that the operands will never have enumeral types
2955 because either they have just had the default conversions performed
2956 or they have both just been converted to some other type in which
2957 the arithmetic is to be done.
2959 C++: must do special pointer arithmetic when implementing
2960 multiple inheritance, and deal with pointer to member functions. */
2963 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2964 int convert_p ATTRIBUTE_UNUSED)
2967 enum tree_code code0, code1;
2969 const char *invalid_op_diag;
2971 /* Expression code to give to the expression when it is built.
2972 Normally this is CODE, which is what the caller asked for,
2973 but in some special cases we change it. */
2974 enum tree_code resultcode = code;
2976 /* Data type in which the computation is to be performed.
2977 In the simplest cases this is the common type of the arguments. */
2978 tree result_type = NULL;
2980 /* Nonzero means operands have already been type-converted
2981 in whatever way is necessary.
2982 Zero means they need to be converted to RESULT_TYPE. */
2985 /* Nonzero means create the expression with this type, rather than
2987 tree build_type = 0;
2989 /* Nonzero means after finally constructing the expression
2990 convert it to this type. */
2991 tree final_type = 0;
2995 /* Nonzero if this is an operation like MIN or MAX which can
2996 safely be computed in short if both args are promoted shorts.
2997 Also implies COMMON.
2998 -1 indicates a bitwise operation; this makes a difference
2999 in the exact conditions for when it is safe to do the operation
3000 in a narrower mode. */
3003 /* Nonzero if this is a comparison operation;
3004 if both args are promoted shorts, compare the original shorts.
3005 Also implies COMMON. */
3006 int short_compare = 0;
3008 /* Nonzero if this is a right-shift operation, which can be computed on the
3009 original short and then promoted if the operand is a promoted short. */
3010 int short_shift = 0;
3012 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3015 /* True if both operands have arithmetic type. */
3016 bool arithmetic_types_p;
3018 /* Apply default conversions. */
3022 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3023 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3024 || code == TRUTH_XOR_EXPR)
3026 if (!really_overloaded_fn (op0))
3027 op0 = decay_conversion (op0);
3028 if (!really_overloaded_fn (op1))
3029 op1 = decay_conversion (op1);
3033 if (!really_overloaded_fn (op0))
3034 op0 = default_conversion (op0);
3035 if (!really_overloaded_fn (op1))
3036 op1 = default_conversion (op1);
3039 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3040 STRIP_TYPE_NOPS (op0);
3041 STRIP_TYPE_NOPS (op1);
3043 /* DTRT if one side is an overloaded function, but complain about it. */
3044 if (type_unknown_p (op0))
3046 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3047 if (t != error_mark_node)
3049 pedwarn ("assuming cast to type %qT from overloaded function",
3054 if (type_unknown_p (op1))
3056 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3057 if (t != error_mark_node)
3059 pedwarn ("assuming cast to type %qT from overloaded function",
3065 type0 = TREE_TYPE (op0);
3066 type1 = TREE_TYPE (op1);
3068 /* The expression codes of the data types of the arguments tell us
3069 whether the arguments are integers, floating, pointers, etc. */
3070 code0 = TREE_CODE (type0);
3071 code1 = TREE_CODE (type1);
3073 /* If an error was already reported for one of the arguments,
3074 avoid reporting another error. */
3076 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3077 return error_mark_node;
3079 if ((invalid_op_diag
3080 = targetm.invalid_binary_op (code, type0, type1)))
3082 error (invalid_op_diag);
3083 return error_mark_node;
3089 /* Subtraction of two similar pointers.
3090 We must subtract them as integers, then divide by object size. */
3091 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3092 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3094 return pointer_diff (op0, op1, common_type (type0, type1));
3095 /* In all other cases except pointer - int, the usual arithmetic
3097 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3102 /* The pointer - int case is just like pointer + int; fall
3105 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3106 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3110 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3111 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3112 if (processing_template_decl)
3114 result_type = TREE_TYPE (ptr_operand);
3117 return cp_pointer_int_sum (code,
3128 case TRUNC_DIV_EXPR:
3130 case FLOOR_DIV_EXPR:
3131 case ROUND_DIV_EXPR:
3132 case EXACT_DIV_EXPR:
3133 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3134 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3135 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3136 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3138 enum tree_code tcode0 = code0, tcode1 = code1;
3140 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3141 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3142 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3143 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3145 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3146 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3147 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3148 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3150 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3151 resultcode = RDIV_EXPR;
3153 /* When dividing two signed integers, we have to promote to int.
3154 unless we divide by a constant != -1. Note that default
3155 conversion will have been performed on the operands at this
3156 point, so we have to dig out the original type to find out if
3158 shorten = ((TREE_CODE (op0) == NOP_EXPR
3159 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3160 || (TREE_CODE (op1) == INTEGER_CST
3161 && ! integer_all_onesp (op1)));
3170 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3171 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3175 case TRUNC_MOD_EXPR:
3176 case FLOOR_MOD_EXPR:
3177 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3178 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3179 else if (code1 == REAL_TYPE && real_zerop (op1))
3180 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3182 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3184 /* Although it would be tempting to shorten always here, that loses
3185 on some targets, since the modulo instruction is undefined if the
3186 quotient can't be represented in the computation mode. We shorten
3187 only if unsigned or if dividing by something we know != -1. */
3188 shorten = ((TREE_CODE (op0) == NOP_EXPR
3189 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3190 || (TREE_CODE (op1) == INTEGER_CST
3191 && ! integer_all_onesp (op1)));
3196 case TRUTH_ANDIF_EXPR:
3197 case TRUTH_ORIF_EXPR:
3198 case TRUTH_AND_EXPR:
3200 result_type = boolean_type_node;
3203 /* Shift operations: result has same type as first operand;
3204 always convert second operand to int.
3205 Also set SHORT_SHIFT if shifting rightward. */
3208 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3210 result_type = type0;
3211 if (TREE_CODE (op1) == INTEGER_CST)
3213 if (tree_int_cst_lt (op1, integer_zero_node))
3214 warning (0, "right shift count is negative");
3217 if (! integer_zerop (op1))
3219 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3220 warning (0, "right shift count >= width of type");
3223 /* Convert the shift-count to an integer, regardless of
3224 size of value being shifted. */
3225 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3226 op1 = cp_convert (integer_type_node, op1);
3227 /* Avoid converting op1 to result_type later. */
3233 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3235 result_type = type0;
3236 if (TREE_CODE (op1) == INTEGER_CST)
3238 if (tree_int_cst_lt (op1, integer_zero_node))
3239 warning (0, "left shift count is negative");
3240 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3241 warning (0, "left shift count >= width of type");
3243 /* Convert the shift-count to an integer, regardless of
3244 size of value being shifted. */
3245 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3246 op1 = cp_convert (integer_type_node, op1);
3247 /* Avoid converting op1 to result_type later. */
3254 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3256 result_type = type0;
3257 if (TREE_CODE (op1) == INTEGER_CST)
3259 if (tree_int_cst_lt (op1, integer_zero_node))
3260 warning (0, "%s rotate count is negative",
3261 (code == LROTATE_EXPR) ? "left" : "right");
3262 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3263 warning (0, "%s rotate count >= width of type",
3264 (code == LROTATE_EXPR) ? "left" : "right");
3266 /* Convert the shift-count to an integer, regardless of
3267 size of value being shifted. */
3268 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3269 op1 = cp_convert (integer_type_node, op1);
3275 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3276 warning (OPT_Wfloat_equal,
3277 "comparing floating point with == or != is unsafe");
3278 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3279 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3280 warning (OPT_Waddress,
3281 "comparison with string literal results in unspecified behaviour");
3283 build_type = boolean_type_node;
3284 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3285 || code0 == COMPLEX_TYPE)
3286 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3287 || code1 == COMPLEX_TYPE))
3289 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3290 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3291 result_type = composite_pointer_type (type0, type1, op0, op1,
3293 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3294 && null_ptr_cst_p (op1))
3295 result_type = type0;
3296 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3297 && null_ptr_cst_p (op0))
3298 result_type = type1;
3299 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3301 result_type = type0;
3302 error ("ISO C++ forbids comparison between pointer and integer");
3304 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3306 result_type = type1;
3307 error ("ISO C++ forbids comparison between pointer and integer");
3309 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3311 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3312 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3313 result_type = TREE_TYPE (op0);
3315 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3316 return cp_build_binary_op (code, op1, op0);
3317 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3318 && same_type_p (type0, type1))
3320 /* E will be the final comparison. */
3322 /* E1 and E2 are for scratch. */
3330 if (TREE_SIDE_EFFECTS (op0))
3331 op0 = save_expr (op0);
3332 if (TREE_SIDE_EFFECTS (op1))
3333 op1 = save_expr (op1);
3338 && (!op0.pfn || op0.delta == op1.delta))
3340 The reason for the `!op0.pfn' bit is that a NULL
3341 pointer-to-member is any member with a zero PFN; the
3342 DELTA field is unspecified. */
3343 pfn0 = pfn_from_ptrmemfunc (op0);
3344 pfn1 = pfn_from_ptrmemfunc (op1);
3345 delta0 = build_ptrmemfunc_access_expr (op0,
3347 delta1 = build_ptrmemfunc_access_expr (op1,
3349 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3350 e2 = cp_build_binary_op (EQ_EXPR,
3352 cp_convert (TREE_TYPE (pfn0),
3353 integer_zero_node));
3354 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3355 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3356 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3357 if (code == EQ_EXPR)
3359 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3363 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3364 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3366 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3367 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3375 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3376 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3378 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3379 result_type = composite_pointer_type (type0, type1, op0, op1,
3387 if (TREE_CODE (orig_op0) == STRING_CST
3388 || TREE_CODE (orig_op1) == STRING_CST)
3389 warning (OPT_Waddress,
3390 "comparison with string literal results in unspecified behaviour");
3392 build_type = boolean_type_node;
3393 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3394 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3396 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3397 result_type = composite_pointer_type (type0, type1, op0, op1,
3399 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3400 && integer_zerop (op1))
3401 result_type = type0;
3402 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3403 && integer_zerop (op0))
3404 result_type = type1;
3405 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3407 result_type = type0;
3408 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3410 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3412 result_type = type1;
3413 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3417 case UNORDERED_EXPR:
3424 build_type = integer_type_node;
3425 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3427 error ("unordered comparison on non-floating point argument");
3428 return error_mark_node;
3437 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3438 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3439 || code1 == COMPLEX_TYPE)))
3440 arithmetic_types_p = 1;
3443 arithmetic_types_p = 0;
3444 /* Vector arithmetic is only allowed when both sides are vectors. */
3445 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3447 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3448 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3451 binary_op_error (code);
3452 return error_mark_node;
3454 arithmetic_types_p = 1;
3457 /* Determine the RESULT_TYPE, if it is not already known. */
3459 && arithmetic_types_p
3460 && (shorten || common || short_compare))
3461 result_type = common_type (type0, type1);
3465 error ("invalid operands of types %qT and %qT to binary %qO",
3466 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3467 return error_mark_node;
3470 /* If we're in a template, the only thing we need to know is the
3472 if (processing_template_decl)
3473 return build2 (resultcode,
3474 build_type ? build_type : result_type,
3477 if (arithmetic_types_p)
3479 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3481 /* For certain operations (which identify themselves by shorten != 0)
3482 if both args were extended from the same smaller type,
3483 do the arithmetic in that type and then extend.
3485 shorten !=0 and !=1 indicates a bitwise operation.
3486 For them, this optimization is safe only if
3487 both args are zero-extended or both are sign-extended.
3488 Otherwise, we might change the result.
3489 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3490 but calculated in (unsigned short) it would be (unsigned short)-1. */
3492 if (shorten && none_complex)
3494 int unsigned0, unsigned1;
3495 tree arg0 = get_narrower (op0, &unsigned0);
3496 tree arg1 = get_narrower (op1, &unsigned1);
3497 /* UNS is 1 if the operation to be done is an unsigned one. */
3498 int uns = TYPE_UNSIGNED (result_type);
3501 final_type = result_type;
3503 /* Handle the case that OP0 does not *contain* a conversion
3504 but it *requires* conversion to FINAL_TYPE. */
3506 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3507 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3508 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3509 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3511 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3513 /* For bitwise operations, signedness of nominal type
3514 does not matter. Consider only how operands were extended. */
3518 /* Note that in all three cases below we refrain from optimizing
3519 an unsigned operation on sign-extended args.
3520 That would not be valid. */
3522 /* Both args variable: if both extended in same way
3523 from same width, do it in that width.
3524 Do it unsigned if args were zero-extended. */
3525 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3526 < TYPE_PRECISION (result_type))
3527 && (TYPE_PRECISION (TREE_TYPE (arg1))
3528 == TYPE_PRECISION (TREE_TYPE (arg0)))
3529 && unsigned0 == unsigned1
3530 && (unsigned0 || !uns))
3531 result_type = c_common_signed_or_unsigned_type
3532 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3533 else if (TREE_CODE (arg0) == INTEGER_CST
3534 && (unsigned1 || !uns)
3535 && (TYPE_PRECISION (TREE_TYPE (arg1))
3536 < TYPE_PRECISION (result_type))
3537 && (type = c_common_signed_or_unsigned_type
3538 (unsigned1, TREE_TYPE (arg1)),
3539 int_fits_type_p (arg0, type)))
3541 else if (TREE_CODE (arg1) == INTEGER_CST
3542 && (unsigned0 || !uns)
3543 && (TYPE_PRECISION (TREE_TYPE (arg0))
3544 < TYPE_PRECISION (result_type))
3545 && (type = c_common_signed_or_unsigned_type
3546 (unsigned0, TREE_TYPE (arg0)),
3547 int_fits_type_p (arg1, type)))
3551 /* Shifts can be shortened if shifting right. */
3556 tree arg0 = get_narrower (op0, &unsigned_arg);
3558 final_type = result_type;
3560 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3561 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3563 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3564 /* We can shorten only if the shift count is less than the
3565 number of bits in the smaller type size. */
3566 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3567 /* If arg is sign-extended and then unsigned-shifted,
3568 we can simulate this with a signed shift in arg's type
3569 only if the extended result is at least twice as wide
3570 as the arg. Otherwise, the shift could use up all the
3571 ones made by sign-extension and bring in zeros.
3572 We can't optimize that case at all, but in most machines
3573 it never happens because available widths are 2**N. */
3574 && (!TYPE_UNSIGNED (final_type)
3576 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3577 <= TYPE_PRECISION (result_type))))
3579 /* Do an unsigned shift if the operand was zero-extended. */
3581 = c_common_signed_or_unsigned_type (unsigned_arg,
3583 /* Convert value-to-be-shifted to that type. */
3584 if (TREE_TYPE (op0) != result_type)
3585 op0 = cp_convert (result_type, op0);
3590 /* Comparison operations are shortened too but differently.
3591 They identify themselves by setting short_compare = 1. */
3595 /* Don't write &op0, etc., because that would prevent op0
3596 from being kept in a register.
3597 Instead, make copies of the our local variables and
3598 pass the copies by reference, then copy them back afterward. */
3599 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3600 enum tree_code xresultcode = resultcode;
3602 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3604 return cp_convert (boolean_type_node, val);
3605 op0 = xop0, op1 = xop1;
3607 resultcode = xresultcode;
3610 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3611 && warn_sign_compare
3612 /* Do not warn until the template is instantiated; we cannot
3613 bound the ranges of the arguments until that point. */
3614 && !processing_template_decl)
3616 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3617 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3619 int unsignedp0, unsignedp1;
3620 tree primop0 = get_narrower (op0, &unsignedp0);
3621 tree primop1 = get_narrower (op1, &unsignedp1);
3623 /* Check for comparison of different enum types. */
3624 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3625 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3626 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3627 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3629 warning (0, "comparison between types %q#T and %q#T",
3630 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3633 /* Give warnings for comparisons between signed and unsigned
3634 quantities that may fail. */
3635 /* Do the checking based on the original operand trees, so that
3636 casts will be considered, but default promotions won't be. */
3638 /* Do not warn if the comparison is being done in a signed type,
3639 since the signed type will only be chosen if it can represent
3640 all the values of the unsigned type. */
3641 if (!TYPE_UNSIGNED (result_type))
3643 /* Do not warn if both operands are unsigned. */
3644 else if (op0_signed == op1_signed)
3646 /* Do not warn if the signed quantity is an unsuffixed
3647 integer literal (or some static constant expression
3648 involving such literals or a conditional expression
3649 involving such literals) and it is non-negative. */
3650 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3651 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3653 /* Do not warn if the comparison is an equality operation,
3654 the unsigned quantity is an integral constant and it does
3655 not use the most significant bit of result_type. */
3656 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3657 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3658 && int_fits_type_p (orig_op1, c_common_signed_type
3660 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3661 && int_fits_type_p (orig_op0, c_common_signed_type
3665 warning (0, "comparison between signed and unsigned integer expressions");
3667 /* Warn if two unsigned values are being compared in a size
3668 larger than their original size, and one (and only one) is the
3669 result of a `~' operator. This comparison will always fail.
3671 Also warn if one operand is a constant, and the constant does not
3672 have all bits set that are set in the ~ operand when it is
3675 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3676 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3678 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3679 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3680 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3681 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3683 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3686 HOST_WIDE_INT constant, mask;
3690 if (host_integerp (primop0, 0))
3693 unsignedp = unsignedp1;
3694 constant = tree_low_cst (primop0, 0);
3699 unsignedp = unsignedp0;
3700 constant = tree_low_cst (primop1, 0);
3703 bits = TYPE_PRECISION (TREE_TYPE (primop));
3704 if (bits < TYPE_PRECISION (result_type)
3705 && bits < HOST_BITS_PER_LONG && unsignedp)
3707 mask = (~ (HOST_WIDE_INT) 0) << bits;
3708 if ((mask & constant) != mask)
3709 warning (0, "comparison of promoted ~unsigned with constant");
3712 else if (unsignedp0 && unsignedp1
3713 && (TYPE_PRECISION (TREE_TYPE (primop0))
3714 < TYPE_PRECISION (result_type))
3715 && (TYPE_PRECISION (TREE_TYPE (primop1))
3716 < TYPE_PRECISION (result_type)))
3717 warning (0, "comparison of promoted ~unsigned with unsigned");
3722 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3723 Then the expression will be built.
3724 It will be given type FINAL_TYPE if that is nonzero;
3725 otherwise, it will be given type RESULT_TYPE. */
3727 /* Issue warnings about peculiar, but valid, uses of NULL. */
3728 if (/* It's reasonable to use pointer values as operands of &&
3729 and ||, so NULL is no exception. */
3730 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3731 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3732 (orig_op0 == null_node
3733 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3734 /* Or vice versa. */
3735 || (orig_op1 == null_node
3736 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3737 /* Or, both are NULL and the operation was not a comparison. */
3738 || (orig_op0 == null_node && orig_op1 == null_node
3739 && code != EQ_EXPR && code != NE_EXPR)))
3740 /* Some sort of arithmetic operation involving NULL was
3741 performed. Note that pointer-difference and pointer-addition
3742 have already been handled above, and so we don't end up here in
3744 warning (0, "NULL used in arithmetic");
3748 if (TREE_TYPE (op0) != result_type)
3749 op0 = cp_convert (result_type, op0);
3750 if (TREE_TYPE (op1) != result_type)
3751 op1 = cp_convert (result_type, op1);
3753 if (op0 == error_mark_node || op1 == error_mark_node)
3754 return error_mark_node;
3757 if (build_type == NULL_TREE)
3758 build_type = result_type;
3760 result = build2 (resultcode, build_type, op0, op1);
3761 result = fold_if_not_in_template (result);
3762 if (final_type != 0)
3763 result = cp_convert (final_type, result);
3767 /* Return a tree for the sum or difference (RESULTCODE says which)
3768 of pointer PTROP and integer INTOP. */
3771 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3773 tree res_type = TREE_TYPE (ptrop);
3775 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3776 in certain circumstance (when it's valid to do so). So we need
3777 to make sure it's complete. We don't need to check here, if we
3778 can actually complete it at all, as those checks will be done in
3779 pointer_int_sum() anyway. */
3780 complete_type (TREE_TYPE (res_type));
3782 return pointer_int_sum (resultcode, ptrop,
3783 fold_if_not_in_template (intop));
3786 /* Return a tree for the difference of pointers OP0 and OP1.
3787 The resulting tree has type int. */
3790 pointer_diff (tree op0, tree op1, tree ptrtype)
3793 tree restype = ptrdiff_type_node;
3794 tree target_type = TREE_TYPE (ptrtype);
3796 if (!complete_type_or_else (target_type, NULL_TREE))
3797 return error_mark_node;
3799 if (pedantic || warn_pointer_arith)
3801 if (TREE_CODE (target_type) == VOID_TYPE)
3802 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3803 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3804 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3805 if (TREE_CODE (target_type) == METHOD_TYPE)
3806 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3809 /* First do the subtraction as integers;
3810 then drop through to build the divide operator. */
3812 op0 = cp_build_binary_op (MINUS_EXPR,
3813 cp_convert (restype, op0),
3814 cp_convert (restype, op1));
3816 /* This generates an error if op1 is a pointer to an incomplete type. */
3817 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3818 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3820 op1 = (TYPE_PTROB_P (ptrtype)
3821 ? size_in_bytes (target_type)
3822 : integer_one_node);
3824 /* Do the division. */
3826 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3827 return fold_if_not_in_template (result);
3830 /* Construct and perhaps optimize a tree representation
3831 for a unary operation. CODE, a tree_code, specifies the operation
3832 and XARG is the operand. */
3835 build_x_unary_op (enum tree_code code, tree xarg)
3837 tree orig_expr = xarg;
3841 if (processing_template_decl)
3843 if (type_dependent_expression_p (xarg))
3844 return build_min_nt (code, xarg, NULL_TREE);
3846 xarg = build_non_dependent_expr (xarg);
3851 /* [expr.unary.op] says:
3853 The address of an object of incomplete type can be taken.
3855 (And is just the ordinary address operator, not an overloaded
3856 "operator &".) However, if the type is a template
3857 specialization, we must complete the type at this point so that
3858 an overloaded "operator &" will be available if required. */
3859 if (code == ADDR_EXPR
3860 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3861 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3862 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3863 || (TREE_CODE (xarg) == OFFSET_REF)))
3864 /* Don't look for a function. */;
3866 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3867 /*overloaded_p=*/NULL);
3868 if (!exp && code == ADDR_EXPR)
3870 /* A pointer to member-function can be formed only by saying
3872 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3873 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3875 if (TREE_CODE (xarg) != OFFSET_REF
3876 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3878 error ("invalid use of %qE to form a pointer-to-member-function",
3880 if (TREE_CODE (xarg) != OFFSET_REF)
3881 inform (" a qualified-id is required");
3882 return error_mark_node;
3886 error ("parentheses around %qE cannot be used to form a"
3887 " pointer-to-member-function",
3889 PTRMEM_OK_P (xarg) = 1;
3893 if (TREE_CODE (xarg) == OFFSET_REF)
3895 ptrmem = PTRMEM_OK_P (xarg);
3897 if (!ptrmem && !flag_ms_extensions
3898 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3900 /* A single non-static member, make sure we don't allow a
3901 pointer-to-member. */
3902 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3903 TREE_OPERAND (xarg, 0),
3904 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3905 PTRMEM_OK_P (xarg) = ptrmem;
3908 else if (TREE_CODE (xarg) == TARGET_EXPR)
3909 warning (0, "taking address of temporary");
3910 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3913 if (processing_template_decl && exp != error_mark_node)
3914 exp = build_min_non_dep (code, exp, orig_expr,
3915 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3916 if (TREE_CODE (exp) == ADDR_EXPR)
3917 PTRMEM_OK_P (exp) = ptrmem;
3921 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3922 constants, where a null value is represented by an INTEGER_CST of
3926 cp_truthvalue_conversion (tree expr)
3928 tree type = TREE_TYPE (expr);
3929 if (TYPE_PTRMEM_P (type))
3930 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3932 return c_common_truthvalue_conversion (expr);
3935 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3938 condition_conversion (tree expr)
3941 if (processing_template_decl)
3943 t = perform_implicit_conversion (boolean_type_node, expr);
3944 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3948 /* Return an ADDR_EXPR giving the address of T. This function
3949 attempts no optimizations or simplifications; it is a low-level
3953 build_address (tree t)
3957 if (error_operand_p (t) || !cxx_mark_addressable (t))
3958 return error_mark_node;
3960 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3965 /* Return a NOP_EXPR converting EXPR to TYPE. */
3968 build_nop (tree type, tree expr)
3970 if (type == error_mark_node || error_operand_p (expr))
3972 return build1 (NOP_EXPR, type, expr);
3975 /* C++: Must handle pointers to members.
3977 Perhaps type instantiation should be extended to handle conversion
3978 from aggregates to types we don't yet know we want? (Or are those
3979 cases typically errors which should be reported?)
3981 NOCONVERT nonzero suppresses the default promotions
3982 (such as from short to int). */
3985 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3987 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3990 const char *errstring = NULL;
3992 const char *invalid_op_diag;
3994 if (arg == error_mark_node)
3995 return error_mark_node;
3997 if ((invalid_op_diag
3998 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4003 error (invalid_op_diag);
4004 return error_mark_node;
4009 case UNARY_PLUS_EXPR:
4012 int flags = WANT_ARITH | WANT_ENUM;
4013 /* Unary plus (but not unary minus) is allowed on pointers. */
4014 if (code == UNARY_PLUS_EXPR)
4015 flags |= WANT_POINTER;
4016 arg = build_expr_type_conversion (flags, arg, true);
4018 errstring = (code == NEGATE_EXPR
4019 ? "wrong type argument to unary minus"
4020 : "wrong type argument to unary plus");
4023 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4024 arg = perform_integral_promotions (arg);
4026 /* Make sure the result is not an lvalue: a unary plus or minus
4027 expression is always a rvalue. */
4034 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4038 arg = default_conversion (arg);
4040 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4043 errstring = "wrong type argument to bit-complement";
4044 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4045 arg = perform_integral_promotions (arg);
4049 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4050 errstring = "wrong type argument to abs";
4051 else if (!noconvert)
4052 arg = default_conversion (arg);
4056 /* Conjugating a real value is a no-op, but allow it anyway. */
4057 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4058 errstring = "wrong type argument to conjugation";
4059 else if (!noconvert)
4060 arg = default_conversion (arg);
4063 case TRUTH_NOT_EXPR:
4064 arg = perform_implicit_conversion (boolean_type_node, arg);
4065 val = invert_truthvalue (arg);
4066 if (arg != error_mark_node)
4068 errstring = "in argument to unary !";
4075 if (TREE_CODE (arg) == COMPLEX_CST)
4076 return TREE_REALPART (arg);
4077 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4079 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4080 return fold_if_not_in_template (arg);
4086 if (TREE_CODE (arg) == COMPLEX_CST)
4087 return TREE_IMAGPART (arg);
4088 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4090 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4091 return fold_if_not_in_template (arg);
4094 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4096 case PREINCREMENT_EXPR:
4097 case POSTINCREMENT_EXPR:
4098 case PREDECREMENT_EXPR:
4099 case POSTDECREMENT_EXPR:
4100 /* Handle complex lvalues (when permitted)
4101 by reduction to simpler cases. */
4103 val = unary_complex_lvalue (code, arg);
4107 /* Increment or decrement the real part of the value,
4108 and don't change the imaginary part. */
4109 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4113 arg = stabilize_reference (arg);
4114 real = build_unary_op (REALPART_EXPR, arg, 1);
4115 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4116 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4117 build_unary_op (code, real, 1), imag);
4120 /* Report invalid types. */
4122 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4125 if (code == PREINCREMENT_EXPR)
4126 errstring ="no pre-increment operator for type";
4127 else if (code == POSTINCREMENT_EXPR)
4128 errstring ="no post-increment operator for type";
4129 else if (code == PREDECREMENT_EXPR)
4130 errstring ="no pre-decrement operator for type";
4132 errstring ="no post-decrement operator for type";
4136 /* Report something read-only. */
4138 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4139 || TREE_READONLY (arg))
4140 readonly_error (arg, ((code == PREINCREMENT_EXPR
4141 || code == POSTINCREMENT_EXPR)
4142 ? "increment" : "decrement"),
4148 tree result_type = TREE_TYPE (arg);
4150 declared_type = unlowered_expr_type (arg);
4152 arg = get_unwidened (arg, 0);
4153 argtype = TREE_TYPE (arg);
4155 /* ARM $5.2.5 last annotation says this should be forbidden. */
4156 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4157 pedwarn ("ISO C++ forbids %sing an enum",
4158 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4159 ? "increment" : "decrement");
4161 /* Compute the increment. */
4163 if (TREE_CODE (argtype) == POINTER_TYPE)
4165 tree type = complete_type (TREE_TYPE (argtype));
4167 if (!COMPLETE_OR_VOID_TYPE_P (type))
4168 error ("cannot %s a pointer to incomplete type %qT",
4169 ((code == PREINCREMENT_EXPR
4170 || code == POSTINCREMENT_EXPR)
4171 ? "increment" : "decrement"), TREE_TYPE (argtype));
4172 else if ((pedantic || warn_pointer_arith)
4173 && !TYPE_PTROB_P (argtype))
4174 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
4175 ((code == PREINCREMENT_EXPR
4176 || code == POSTINCREMENT_EXPR)
4177 ? "increment" : "decrement"), argtype);
4178 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4181 inc = integer_one_node;
4183 inc = cp_convert (argtype, inc);
4185 /* Handle incrementing a cast-expression. */
4187 switch (TREE_CODE (arg))
4192 case FIX_TRUNC_EXPR:
4193 case FIX_FLOOR_EXPR:
4194 case FIX_ROUND_EXPR:
4197 tree incremented, modify, value, compound;
4198 if (! lvalue_p (arg) && pedantic)
4199 pedwarn ("cast to non-reference type used as lvalue");
4200 arg = stabilize_reference (arg);
4201 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4204 value = save_expr (arg);
4205 incremented = build2 (((code == PREINCREMENT_EXPR
4206 || code == POSTINCREMENT_EXPR)
4207 ? PLUS_EXPR : MINUS_EXPR),
4208 argtype, value, inc);
4210 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4211 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4214 /* Eliminate warning about unused result of + or -. */
4215 TREE_NO_WARNING (compound) = 1;
4223 /* Complain about anything else that is not a true lvalue. */
4224 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4225 || code == POSTINCREMENT_EXPR)
4226 ? lv_increment : lv_decrement)))
4227 return error_mark_node;
4229 /* Forbid using -- on `bool'. */
4230 if (same_type_p (declared_type, boolean_type_node))
4232 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4234 error ("invalid use of %<--%> on bool variable %qD", arg);
4235 return error_mark_node;
4237 val = boolean_increment (code, arg);
4240 val = build2 (code, TREE_TYPE (arg), arg, inc);
4242 TREE_SIDE_EFFECTS (val) = 1;
4243 return cp_convert (result_type, val);
4247 /* Note that this operation never does default_conversion
4248 regardless of NOCONVERT. */
4250 argtype = lvalue_type (arg);
4252 if (TREE_CODE (arg) == OFFSET_REF)
4255 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4257 tree type = build_pointer_type (TREE_TYPE (argtype));
4258 arg = build1 (CONVERT_EXPR, type, arg);
4261 else if (pedantic && DECL_MAIN_P (arg))
4263 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4265 /* Let &* cancel out to simplify resulting code. */
4266 if (TREE_CODE (arg) == INDIRECT_REF)
4268 /* We don't need to have `current_class_ptr' wrapped in a
4269 NON_LVALUE_EXPR node. */
4270 if (arg == current_class_ref)
4271 return current_class_ptr;
4273 arg = TREE_OPERAND (arg, 0);
4274 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4276 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4277 arg = build1 (CONVERT_EXPR, type, arg);
4280 /* Don't let this be an lvalue. */
4285 /* Uninstantiated types are all functions. Taking the
4286 address of a function is a no-op, so just return the
4289 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4290 || !IDENTIFIER_OPNAME_P (arg));
4292 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4293 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4295 /* They're trying to take the address of a unique non-static
4296 member function. This is ill-formed (except in MS-land),
4297 but let's try to DTRT.
4298 Note: We only handle unique functions here because we don't
4299 want to complain if there's a static overload; non-unique
4300 cases will be handled by instantiate_type. But we need to
4301 handle this case here to allow casts on the resulting PMF.
4302 We could defer this in non-MS mode, but it's easier to give
4303 a useful error here. */
4305 /* Inside constant member functions, the `this' pointer
4306 contains an extra const qualifier. TYPE_MAIN_VARIANT
4307 is used here to remove this const from the diagnostics
4308 and the created OFFSET_REF. */
4309 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4310 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4313 if (! flag_ms_extensions)
4315 tree name = DECL_NAME (fn);
4316 if (current_class_type
4317 && TREE_OPERAND (arg, 0) == current_class_ref)
4318 /* An expression like &memfn. */
4319 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4320 " or parenthesized non-static member function to form"
4321 " a pointer to member function. Say %<&%T::%D%>",
4324 pedwarn ("ISO C++ forbids taking the address of a bound member"
4325 " function to form a pointer to member function."
4329 arg = build_offset_ref (base, fn, /*address_p=*/true);
4333 if (type_unknown_p (arg))
4334 return build1 (ADDR_EXPR, unknown_type_node, arg);
4336 /* Handle complex lvalues (when permitted)
4337 by reduction to simpler cases. */
4338 val = unary_complex_lvalue (code, arg);
4342 switch (TREE_CODE (arg))
4347 case FIX_TRUNC_EXPR:
4348 case FIX_FLOOR_EXPR:
4349 case FIX_ROUND_EXPR:
4351 if (! lvalue_p (arg) && pedantic)
4352 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4356 arg = BASELINK_FUNCTIONS (arg);
4360 arg = OVL_CURRENT (arg);
4364 /* Turn a reference to a non-static data member into a
4365 pointer-to-member. */
4370 if (!PTRMEM_OK_P (arg))
4371 return build_unary_op (code, arg, 0);
4373 t = TREE_OPERAND (arg, 1);
4374 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4376 error ("cannot create pointer to reference member %qD", t);
4377 return error_mark_node;
4380 type = build_ptrmem_type (context_for_name_lookup (t),
4382 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4390 /* Anything not already handled and not a true memory reference
4392 if (TREE_CODE (argtype) != FUNCTION_TYPE
4393 && TREE_CODE (argtype) != METHOD_TYPE
4394 && TREE_CODE (arg) != OFFSET_REF
4395 && !lvalue_or_else (arg, lv_addressof))
4396 return error_mark_node;
4398 if (argtype != error_mark_node)
4399 argtype = build_pointer_type (argtype);
4401 /* In a template, we are processing a non-dependent expression
4402 so we can just form an ADDR_EXPR with the correct type. */
4403 if (processing_template_decl)
4405 val = build_address (arg);
4406 if (TREE_CODE (arg) == OFFSET_REF)
4407 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4411 if (TREE_CODE (arg) != COMPONENT_REF)
4413 val = build_address (arg);
4414 if (TREE_CODE (arg) == OFFSET_REF)
4415 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4417 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4419 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4421 /* We can only get here with a single static member
4423 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4424 && DECL_STATIC_FUNCTION_P (fn));
4426 val = build_address (fn);
4427 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4428 /* Do not lose object's side effects. */
4429 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4430 TREE_OPERAND (arg, 0), val);
4432 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4434 error ("attempt to take address of bit-field structure member %qD",
4435 TREE_OPERAND (arg, 1));
4436 return error_mark_node;
4440 tree object = TREE_OPERAND (arg, 0);
4441 tree field = TREE_OPERAND (arg, 1);
4442 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4443 (TREE_TYPE (object), decl_type_context (field)));
4444 val = build_address (arg);
4447 if (TREE_CODE (argtype) == POINTER_TYPE
4448 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4450 build_ptrmemfunc_type (argtype);
4451 val = build_ptrmemfunc (argtype, val, 0,
4452 /*c_cast_p=*/false);
4464 argtype = TREE_TYPE (arg);
4465 return fold_if_not_in_template (build1 (code, argtype, arg));
4468 error ("%s", errstring);
4469 return error_mark_node;
4472 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4473 for certain kinds of expressions which are not really lvalues
4474 but which we can accept as lvalues.
4476 If ARG is not a kind of expression we can handle, return
4480 unary_complex_lvalue (enum tree_code code, tree arg)
4482 /* Inside a template, making these kinds of adjustments is
4483 pointless; we are only concerned with the type of the
4485 if (processing_template_decl)
4488 /* Handle (a, b) used as an "lvalue". */
4489 if (TREE_CODE (arg) == COMPOUND_EXPR)
4491 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4492 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4493 TREE_OPERAND (arg, 0), real_result);
4496 /* Handle (a ? b : c) used as an "lvalue". */
4497 if (TREE_CODE (arg) == COND_EXPR
4498 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4499 return rationalize_conditional_expr (code, arg);
4501 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4502 if (TREE_CODE (arg) == MODIFY_EXPR
4503 || TREE_CODE (arg) == PREINCREMENT_EXPR
4504 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4506 tree lvalue = TREE_OPERAND (arg, 0);
4507 if (TREE_SIDE_EFFECTS (lvalue))
4509 lvalue = stabilize_reference (lvalue);
4510 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4511 lvalue, TREE_OPERAND (arg, 1));
4513 return unary_complex_lvalue
4514 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4517 if (code != ADDR_EXPR)
4520 /* Handle (a = b) used as an "lvalue" for `&'. */
4521 if (TREE_CODE (arg) == MODIFY_EXPR
4522 || TREE_CODE (arg) == INIT_EXPR)
4524 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4525 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4527 TREE_NO_WARNING (arg) = 1;
4531 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4532 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4533 || TREE_CODE (arg) == OFFSET_REF)
4536 /* We permit compiler to make function calls returning
4537 objects of aggregate type look like lvalues. */
4541 if (TREE_CODE (targ) == SAVE_EXPR)
4542 targ = TREE_OPERAND (targ, 0);
4544 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4546 if (TREE_CODE (arg) == SAVE_EXPR)
4549 targ = build_cplus_new (TREE_TYPE (arg), arg);
4550 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4553 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4554 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4555 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4558 /* Don't let anything else be handled specially. */
4562 /* Mark EXP saying that we need to be able to take the
4563 address of it; it should not be allocated in a register.
4564 Value is true if successful.
4566 C++: we do not allow `current_class_ptr' to be addressable. */
4569 cxx_mark_addressable (tree exp)
4574 switch (TREE_CODE (x))
4581 x = TREE_OPERAND (x, 0);
4585 if (x == current_class_ptr)
4587 error ("cannot take the address of %<this%>, which is an rvalue expression");
4588 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4594 /* Caller should not be trying to mark initialized
4595 constant fields addressable. */
4596 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4597 || DECL_IN_AGGR_P (x) == 0
4599 || DECL_EXTERNAL (x));
4604 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4605 && !DECL_ARTIFICIAL (x))
4607 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4610 ("address of explicit register variable %qD requested", x);
4613 else if (extra_warnings)
4615 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4617 TREE_ADDRESSABLE (x) = 1;
4621 TREE_ADDRESSABLE (x) = 1;
4625 TREE_ADDRESSABLE (x) = 1;
4629 TREE_ADDRESSABLE (x) = 1;
4630 cxx_mark_addressable (TREE_OPERAND (x, 0));
4638 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4641 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4643 tree orig_ifexp = ifexp;
4644 tree orig_op1 = op1;
4645 tree orig_op2 = op2;
4648 if (processing_template_decl)
4650 /* The standard says that the expression is type-dependent if
4651 IFEXP is type-dependent, even though the eventual type of the
4652 expression doesn't dependent on IFEXP. */
4653 if (type_dependent_expression_p (ifexp)
4654 /* As a GNU extension, the middle operand may be omitted. */
4655 || (op1 && type_dependent_expression_p (op1))
4656 || type_dependent_expression_p (op2))
4657 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4658 ifexp = build_non_dependent_expr (ifexp);
4660 op1 = build_non_dependent_expr (op1);
4661 op2 = build_non_dependent_expr (op2);
4664 expr = build_conditional_expr (ifexp, op1, op2);
4665 if (processing_template_decl && expr != error_mark_node)
4666 return build_min_non_dep (COND_EXPR, expr,
4667 orig_ifexp, orig_op1, orig_op2);
4671 /* Given a list of expressions, return a compound expression
4672 that performs them all and returns the value of the last of them. */
4674 tree build_x_compound_expr_from_list (tree list, const char *msg)
4676 tree expr = TREE_VALUE (list);
4678 if (TREE_CHAIN (list))
4681 pedwarn ("%s expression list treated as compound expression", msg);
4683 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4684 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4690 /* Handle overloading of the ',' operator when needed. */
4693 build_x_compound_expr (tree op1, tree op2)
4696 tree orig_op1 = op1;
4697 tree orig_op2 = op2;
4699 if (processing_template_decl)
4701 if (type_dependent_expression_p (op1)
4702 || type_dependent_expression_p (op2))
4703 return build_min_nt (COMPOUND_EXPR, op1, op2);
4704 op1 = build_non_dependent_expr (op1);
4705 op2 = build_non_dependent_expr (op2);
4708 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4709 /*overloaded_p=*/NULL);
4711 result = build_compound_expr (op1, op2);
4713 if (processing_template_decl && result != error_mark_node)
4714 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4719 /* Build a compound expression. */
4722 build_compound_expr (tree lhs, tree rhs)
4724 lhs = convert_to_void (lhs, "left-hand operand of comma");
4726 if (lhs == error_mark_node || rhs == error_mark_node)
4727 return error_mark_node;
4729 if (TREE_CODE (rhs) == TARGET_EXPR)
4731 /* If the rhs is a TARGET_EXPR, then build the compound
4732 expression inside the target_expr's initializer. This
4733 helps the compiler to eliminate unnecessary temporaries. */
4734 tree init = TREE_OPERAND (rhs, 1);
4736 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4737 TREE_OPERAND (rhs, 1) = init;
4742 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4745 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4746 casts away constness. DIAG_FN gives the function to call if we
4747 need to issue a diagnostic; if it is NULL, no diagnostic will be
4748 issued. DESCRIPTION explains what operation is taking place. */
4751 check_for_casting_away_constness (tree src_type, tree dest_type,
4752 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4753 const char *description)
4755 if (diag_fn && casts_away_constness (src_type, dest_type))
4756 diag_fn ("%s from type %qT to type %qT casts away constness",
4757 description, src_type, dest_type);
4760 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4761 (another pointer-to-member type in the same hierarchy) and return
4762 the converted expression. If ALLOW_INVERSE_P is permitted, a
4763 pointer-to-derived may be converted to pointer-to-base; otherwise,
4764 only the other direction is permitted. If C_CAST_P is true, this
4765 conversion is taking place as part of a C-style cast. */
4768 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4771 if (TYPE_PTRMEM_P (type))
4775 if (TREE_CODE (expr) == PTRMEM_CST)
4776 expr = cplus_expand_constant (expr);
4777 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4778 TYPE_PTRMEM_CLASS_TYPE (type),
4781 if (!integer_zerop (delta))
4782 expr = cp_build_binary_op (PLUS_EXPR,
4783 build_nop (ptrdiff_type_node, expr),
4785 return build_nop (type, expr);
4788 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4789 allow_inverse_p, c_cast_p);
4792 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4793 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4794 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4797 ignore_overflows (tree expr, tree orig)
4799 if (TREE_CODE (expr) == INTEGER_CST
4800 && CONSTANT_CLASS_P (orig)
4801 && TREE_CODE (orig) != STRING_CST
4802 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4803 || TREE_CONSTANT_OVERFLOW (expr)
4804 != TREE_CONSTANT_OVERFLOW (orig)))
4806 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4807 /* Ensure constant sharing. */
4808 expr = build_int_cst_wide (TREE_TYPE (expr),
4809 TREE_INT_CST_LOW (expr),
4810 TREE_INT_CST_HIGH (expr));
4813 /* Avoid clobbering a shared constant. */
4814 expr = copy_node (expr);
4815 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4816 TREE_CONSTANT_OVERFLOW (expr)
4817 = TREE_CONSTANT_OVERFLOW (orig);
4823 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4824 this static_cast is being attempted as one of the possible casts
4825 allowed by a C-style cast. (In that case, accessibility of base
4826 classes is not considered, and it is OK to cast away
4827 constness.) Return the result of the cast. *VALID_P is set to
4828 indicate whether or not the cast was valid. */
4831 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4837 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4840 /* Assume the cast is valid. */
4843 intype = TREE_TYPE (expr);
4845 /* Save casted types in the function's used types hash table. */
4846 used_types_insert (type);
4848 /* Determine what to do when casting away constness. */
4851 /* C-style casts are allowed to cast away constness. With
4852 WARN_CAST_QUAL, we still want to issue a warning. */
4853 diag_fn = warn_cast_qual ? warning0 : NULL;
4858 /* A static_cast may not cast away constness. */
4860 desc = "static_cast";
4863 /* [expr.static.cast]
4865 An lvalue of type "cv1 B", where B is a class type, can be cast
4866 to type "reference to cv2 D", where D is a class derived (clause
4867 _class.derived_) from B, if a valid standard conversion from
4868 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4869 same cv-qualification as, or greater cv-qualification than, cv1,
4870 and B is not a virtual base class of D. */
4871 /* We check this case before checking the validity of "TYPE t =
4872 EXPR;" below because for this case:
4875 struct D : public B { D(const B&); };
4877 void f() { static_cast<const D&>(b); }
4879 we want to avoid constructing a new D. The standard is not
4880 completely clear about this issue, but our interpretation is
4881 consistent with other compilers. */
4882 if (TREE_CODE (type) == REFERENCE_TYPE
4883 && CLASS_TYPE_P (TREE_TYPE (type))
4884 && CLASS_TYPE_P (intype)
4885 && real_lvalue_p (expr)
4886 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4887 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4888 build_pointer_type (TYPE_MAIN_VARIANT
4889 (TREE_TYPE (type))))
4891 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4895 /* There is a standard conversion from "D*" to "B*" even if "B"
4896 is ambiguous or inaccessible. If this is really a
4897 static_cast, then we check both for inaccessibility and
4898 ambiguity. However, if this is a static_cast being performed
4899 because the user wrote a C-style cast, then accessibility is
4901 base = lookup_base (TREE_TYPE (type), intype,
4902 c_cast_p ? ba_unique : ba_check,
4905 /* Convert from "B*" to "D*". This function will check that "B"
4906 is not a virtual base of "D". */
4907 expr = build_base_path (MINUS_EXPR, build_address (expr),
4908 base, /*nonnull=*/false);
4909 /* Convert the pointer to a reference -- but then remember that
4910 there are no expressions with reference type in C++. */
4911 return convert_from_reference (build_nop (type, expr));
4916 /* [expr.static.cast]
4918 An expression e can be explicitly converted to a type T using a
4919 static_cast of the form static_cast<T>(e) if the declaration T
4920 t(e);" is well-formed, for some invented temporary variable
4922 result = perform_direct_initialization_if_possible (type, expr,
4926 result = convert_from_reference (result);
4928 /* Ignore any integer overflow caused by the cast. */
4929 result = ignore_overflows (result, orig);
4931 /* [expr.static.cast]
4933 If T is a reference type, the result is an lvalue; otherwise,
4934 the result is an rvalue. */
4935 if (TREE_CODE (type) != REFERENCE_TYPE)
4936 result = rvalue (result);
4940 /* [expr.static.cast]
4942 Any expression can be explicitly converted to type cv void. */
4943 if (TREE_CODE (type) == VOID_TYPE)
4944 return convert_to_void (expr, /*implicit=*/NULL);
4946 /* [expr.static.cast]
4948 The inverse of any standard conversion sequence (clause _conv_),
4949 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4950 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4951 (_conv.bool_) conversions, can be performed explicitly using
4952 static_cast subject to the restriction that the explicit
4953 conversion does not cast away constness (_expr.const.cast_), and
4954 the following additional rules for specific cases: */
4955 /* For reference, the conversions not excluded are: integral
4956 promotions, floating point promotion, integral conversions,
4957 floating point conversions, floating-integral conversions,
4958 pointer conversions, and pointer to member conversions. */
4961 A value of integral _or enumeration_ type can be explicitly
4962 converted to an enumeration type. */
4963 /* The effect of all that is that any conversion between any two
4964 types which are integral, floating, or enumeration types can be
4966 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4967 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4969 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4971 /* Ignore any integer overflow caused by the cast. */
4972 expr = ignore_overflows (expr, orig);
4976 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4977 && CLASS_TYPE_P (TREE_TYPE (type))
4978 && CLASS_TYPE_P (TREE_TYPE (intype))
4979 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4980 (TREE_TYPE (intype))),
4981 build_pointer_type (TYPE_MAIN_VARIANT
4982 (TREE_TYPE (type)))))
4987 check_for_casting_away_constness (intype, type, diag_fn, desc);
4988 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4989 c_cast_p ? ba_unique : ba_check,
4991 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4994 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4995 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5002 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5003 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5005 if (TYPE_PTRMEM_P (type))
5007 t1 = (build_ptrmem_type
5009 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5010 t2 = (build_ptrmem_type
5012 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5019 if (can_convert (t1, t2))
5022 check_for_casting_away_constness (intype, type, diag_fn,
5024 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5029 /* [expr.static.cast]
5031 An rvalue of type "pointer to cv void" can be explicitly
5032 converted to a pointer to object type. A value of type pointer
5033 to object converted to "pointer to cv void" and back to the
5034 original pointer type will have its original value. */
5035 if (TREE_CODE (intype) == POINTER_TYPE
5036 && VOID_TYPE_P (TREE_TYPE (intype))
5037 && TYPE_PTROB_P (type))
5040 check_for_casting_away_constness (intype, type, diag_fn, desc);
5041 return build_nop (type, expr);
5045 return error_mark_node;
5048 /* Return an expression representing static_cast<TYPE>(EXPR). */
5051 build_static_cast (tree type, tree expr)
5056 if (type == error_mark_node || expr == error_mark_node)
5057 return error_mark_node;
5059 if (processing_template_decl)
5061 expr = build_min (STATIC_CAST_EXPR, type, expr);
5062 /* We don't know if it will or will not have side effects. */
5063 TREE_SIDE_EFFECTS (expr) = 1;
5064 return convert_from_reference (expr);
5067 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5068 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5069 if (TREE_CODE (type) != REFERENCE_TYPE
5070 && TREE_CODE (expr) == NOP_EXPR
5071 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5072 expr = TREE_OPERAND (expr, 0);
5074 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5078 error ("invalid static_cast from type %qT to type %qT",
5079 TREE_TYPE (expr), type);
5080 return error_mark_node;
5083 /* EXPR is an expression with member function or pointer-to-member
5084 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5085 not permitted by ISO C++, but we accept it in some modes. If we
5086 are not in one of those modes, issue a diagnostic. Return the
5087 converted expression. */
5090 convert_member_func_to_ptr (tree type, tree expr)
5095 intype = TREE_TYPE (expr);
5096 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5097 || TREE_CODE (intype) == METHOD_TYPE);
5099 if (pedantic || warn_pmf2ptr)
5100 pedwarn ("converting from %qT to %qT", intype, type);
5102 if (TREE_CODE (intype) == METHOD_TYPE)
5103 expr = build_addr_func (expr);
5104 else if (TREE_CODE (expr) == PTRMEM_CST)
5105 expr = build_address (PTRMEM_CST_MEMBER (expr));
5108 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5109 decl = build_address (decl);
5110 expr = get_member_function_from_ptrfunc (&decl, expr);
5113 return build_nop (type, expr);
5116 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5117 If C_CAST_P is true, this reinterpret cast is being done as part of
5118 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5119 indicate whether or not reinterpret_cast was valid. */
5122 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5127 /* Assume the cast is invalid. */
5131 if (type == error_mark_node || error_operand_p (expr))
5132 return error_mark_node;
5134 intype = TREE_TYPE (expr);
5136 /* Save casted types in the function's used types hash table. */
5137 used_types_insert (type);
5139 /* [expr.reinterpret.cast]
5140 An lvalue expression of type T1 can be cast to the type
5141 "reference to T2" if an expression of type "pointer to T1" can be
5142 explicitly converted to the type "pointer to T2" using a
5143 reinterpret_cast. */
5144 if (TREE_CODE (type) == REFERENCE_TYPE)
5146 if (! real_lvalue_p (expr))
5148 error ("invalid cast of an rvalue expression of type "
5151 return error_mark_node;
5154 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5155 "B" are related class types; the reinterpret_cast does not
5156 adjust the pointer. */
5157 if (TYPE_PTR_P (intype)
5158 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5159 COMPARE_BASE | COMPARE_DERIVED)))
5160 warning (0, "casting %qT to %qT does not dereference pointer",
5163 expr = build_unary_op (ADDR_EXPR, expr, 0);
5164 if (expr != error_mark_node)
5165 expr = build_reinterpret_cast_1
5166 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5168 if (expr != error_mark_node)
5169 expr = build_indirect_ref (expr, 0);
5173 /* As a G++ extension, we consider conversions from member
5174 functions, and pointers to member functions to
5175 pointer-to-function and pointer-to-void types. If
5176 -Wno-pmf-conversions has not been specified,
5177 convert_member_func_to_ptr will issue an error message. */
5178 if ((TYPE_PTRMEMFUNC_P (intype)
5179 || TREE_CODE (intype) == METHOD_TYPE)
5180 && TYPE_PTR_P (type)
5181 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5182 || VOID_TYPE_P (TREE_TYPE (type))))
5183 return convert_member_func_to_ptr (type, expr);
5185 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5186 array-to-pointer, and function-to-pointer conversions are
5188 expr = decay_conversion (expr);
5190 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5191 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5192 if (TREE_CODE (expr) == NOP_EXPR
5193 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5194 expr = TREE_OPERAND (expr, 0);
5196 if (error_operand_p (expr))
5197 return error_mark_node;
5199 intype = TREE_TYPE (expr);
5201 /* [expr.reinterpret.cast]
5202 A pointer can be converted to any integral type large enough to
5204 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5206 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5207 pedwarn ("cast from %qT to %qT loses precision",
5210 /* [expr.reinterpret.cast]
5211 A value of integral or enumeration type can be explicitly
5212 converted to a pointer. */
5213 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5216 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5217 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5218 return fold_if_not_in_template (build_nop (type, expr));
5219 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5220 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5225 check_for_casting_away_constness (intype, type, error,
5226 "reinterpret_cast");
5227 /* Warn about possible alignment problems. */
5228 if (STRICT_ALIGNMENT && warn_cast_align
5229 && !VOID_TYPE_P (type)
5230 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5231 && COMPLETE_TYPE_P (TREE_TYPE (type))
5232 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5233 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5234 warning (0, "cast from %qT to %qT increases required alignment of "
5238 /* We need to strip nops here, because the frontend likes to
5239 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5241 strict_aliasing_warning (intype, type, sexpr);
5243 return fold_if_not_in_template (build_nop (type, expr));
5245 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5246 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5249 /* Only issue a warning, as we have always supported this
5250 where possible, and it is necessary in some cases. DR 195
5251 addresses this issue, but as of 2004/10/26 is still in
5253 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5254 return fold_if_not_in_template (build_nop (type, expr));
5256 else if (TREE_CODE (type) == VECTOR_TYPE)
5257 return fold_if_not_in_template (convert_to_vector (type, expr));
5258 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5259 return fold_if_not_in_template (convert_to_integer (type, expr));
5264 error ("invalid cast from type %qT to type %qT", intype, type);
5265 return error_mark_node;
5268 return cp_convert (type, expr);
5272 build_reinterpret_cast (tree type, tree expr)
5274 if (type == error_mark_node || expr == error_mark_node)
5275 return error_mark_node;
5277 if (processing_template_decl)
5279 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5281 if (!TREE_SIDE_EFFECTS (t)
5282 && type_dependent_expression_p (expr))
5283 /* There might turn out to be side effects inside expr. */
5284 TREE_SIDE_EFFECTS (t) = 1;
5285 return convert_from_reference (t);
5288 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5292 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5293 return an appropriate expression. Otherwise, return
5294 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5295 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5296 performing a C-style cast, its value upon return will indicate
5297 whether or not the conversion succeeded. */
5300 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5304 tree reference_type;
5306 /* Callers are responsible for handling error_mark_node as a
5307 destination type. */
5308 gcc_assert (dst_type != error_mark_node);
5309 /* In a template, callers should be building syntactic
5310 representations of casts, not using this machinery. */
5311 gcc_assert (!processing_template_decl);
5313 /* Assume the conversion is invalid. */
5317 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5320 error ("invalid use of const_cast with type %qT, "
5321 "which is not a pointer, "
5322 "reference, nor a pointer-to-data-member type", dst_type);
5323 return error_mark_node;
5326 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5329 error ("invalid use of const_cast with type %qT, which is a pointer "
5330 "or reference to a function type", dst_type);
5331 return error_mark_node;
5334 /* Save casted types in the function's used types hash table. */
5335 used_types_insert (dst_type);
5337 src_type = TREE_TYPE (expr);
5338 /* Expressions do not really have reference types. */
5339 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5340 src_type = TREE_TYPE (src_type);
5342 /* [expr.const.cast]
5344 An lvalue of type T1 can be explicitly converted to an lvalue of
5345 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5346 types) if a pointer to T1 can be explicitly converted to the type
5347 pointer to T2 using a const_cast. */
5348 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5350 reference_type = dst_type;
5351 if (! real_lvalue_p (expr))
5354 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5355 src_type, dst_type);
5356 return error_mark_node;
5358 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5359 src_type = build_pointer_type (src_type);
5363 reference_type = NULL_TREE;
5364 /* If the destination type is not a reference type, the
5365 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5366 conversions are performed. */
5367 src_type = type_decays_to (src_type);
5368 if (src_type == error_mark_node)
5369 return error_mark_node;
5372 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5373 && comp_ptr_ttypes_const (dst_type, src_type))
5378 /* This cast is actually a C-style cast. Issue a warning if
5379 the user is making a potentially unsafe cast. */
5381 check_for_casting_away_constness (src_type, dst_type,
5387 expr = build_unary_op (ADDR_EXPR, expr, 0);
5388 expr = build_nop (reference_type, expr);
5389 return convert_from_reference (expr);
5393 expr = decay_conversion (expr);
5394 /* build_c_cast puts on a NOP_EXPR to make the result not an
5395 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5396 non-lvalue context. */
5397 if (TREE_CODE (expr) == NOP_EXPR
5398 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5399 expr = TREE_OPERAND (expr, 0);
5400 return build_nop (dst_type, expr);
5405 error ("invalid const_cast from type %qT to type %qT",
5406 src_type, dst_type);
5407 return error_mark_node;
5411 build_const_cast (tree type, tree expr)
5413 if (type == error_mark_node || error_operand_p (expr))
5414 return error_mark_node;
5416 if (processing_template_decl)
5418 tree t = build_min (CONST_CAST_EXPR, type, expr);
5420 if (!TREE_SIDE_EFFECTS (t)
5421 && type_dependent_expression_p (expr))
5422 /* There might turn out to be side effects inside expr. */
5423 TREE_SIDE_EFFECTS (t) = 1;
5424 return convert_from_reference (t);
5427 return build_const_cast_1 (type, expr, /*complain=*/true,
5431 /* Build an expression representing an explicit C-style cast to type
5432 TYPE of expression EXPR. */
5435 build_c_cast (tree type, tree expr)
5441 if (type == error_mark_node || error_operand_p (expr))
5442 return error_mark_node;
5444 if (processing_template_decl)
5446 tree t = build_min (CAST_EXPR, type,
5447 tree_cons (NULL_TREE, value, NULL_TREE));
5448 /* We don't know if it will or will not have side effects. */
5449 TREE_SIDE_EFFECTS (t) = 1;
5450 return convert_from_reference (t);
5453 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5454 'Class') should always be retained, because this information aids
5455 in method lookup. */
5456 if (objc_is_object_ptr (type)
5457 && objc_is_object_ptr (TREE_TYPE (expr)))
5458 return build_nop (type, expr);
5460 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5461 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5462 if (TREE_CODE (type) != REFERENCE_TYPE
5463 && TREE_CODE (value) == NOP_EXPR
5464 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5465 value = TREE_OPERAND (value, 0);
5467 if (TREE_CODE (type) == ARRAY_TYPE)
5469 /* Allow casting from T1* to T2[] because Cfront allows it.
5470 NIHCL uses it. It is not valid ISO C++ however. */
5471 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5473 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5474 type = build_pointer_type (TREE_TYPE (type));
5478 error ("ISO C++ forbids casting to an array type %qT", type);
5479 return error_mark_node;
5483 if (TREE_CODE (type) == FUNCTION_TYPE
5484 || TREE_CODE (type) == METHOD_TYPE)
5486 error ("invalid cast to function type %qT", type);
5487 return error_mark_node;
5490 /* A C-style cast can be a const_cast. */
5491 result = build_const_cast_1 (type, value, /*complain=*/false,
5496 /* Or a static cast. */
5497 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5499 /* Or a reinterpret_cast. */
5501 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5503 /* The static_cast or reinterpret_cast may be followed by a
5506 /* A valid cast may result in errors if, for example, a
5507 conversion to am ambiguous base class is required. */
5508 && !error_operand_p (result))
5512 /* Non-class rvalues always have cv-unqualified type. */
5513 if (!CLASS_TYPE_P (type))
5514 type = TYPE_MAIN_VARIANT (type);
5515 result_type = TREE_TYPE (result);
5516 if (!CLASS_TYPE_P (result_type))
5517 result_type = TYPE_MAIN_VARIANT (result_type);
5518 /* If the type of RESULT does not match TYPE, perform a
5519 const_cast to make it match. If the static_cast or
5520 reinterpret_cast succeeded, we will differ by at most
5521 cv-qualification, so the follow-on const_cast is guaranteed
5523 if (!same_type_p (non_reference (type), non_reference (result_type)))
5525 result = build_const_cast_1 (type, result, false, &valid_p);
5526 gcc_assert (valid_p);
5531 return error_mark_node;
5534 /* Build an assignment expression of lvalue LHS from value RHS.
5535 MODIFYCODE is the code for a binary operator that we use
5536 to combine the old value of LHS with RHS to get the new value.
5537 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5539 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5542 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5546 tree lhstype = TREE_TYPE (lhs);
5547 tree olhstype = lhstype;
5548 tree olhs = NULL_TREE;
5549 bool plain_assign = (modifycode == NOP_EXPR);
5551 /* Avoid duplicate error messages from operands that had errors. */
5552 if (error_operand_p (lhs) || error_operand_p (rhs))
5553 return error_mark_node;
5555 /* Handle control structure constructs used as "lvalues". */
5556 switch (TREE_CODE (lhs))
5558 /* Handle --foo = 5; as these are valid constructs in C++. */
5559 case PREDECREMENT_EXPR:
5560 case PREINCREMENT_EXPR:
5561 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5562 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5563 stabilize_reference (TREE_OPERAND (lhs, 0)),
5564 TREE_OPERAND (lhs, 1));
5565 return build2 (COMPOUND_EXPR, lhstype,
5567 build_modify_expr (TREE_OPERAND (lhs, 0),
5570 /* Handle (a, b) used as an "lvalue". */
5572 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5574 if (newrhs == error_mark_node)
5575 return error_mark_node;
5576 return build2 (COMPOUND_EXPR, lhstype,
5577 TREE_OPERAND (lhs, 0), newrhs);
5580 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5581 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5582 stabilize_reference (TREE_OPERAND (lhs, 0)),
5583 TREE_OPERAND (lhs, 1));
5584 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5585 if (newrhs == error_mark_node)
5586 return error_mark_node;
5587 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5591 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5592 when neither operand has side-effects. */
5593 if (!lvalue_or_else (lhs, lv_assign))
5594 return error_mark_node;
5596 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5597 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5599 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5600 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5602 TREE_OPERAND (lhs, 0),
5603 TREE_OPERAND (lhs, 1)),
5604 TREE_OPERAND (lhs, 0),
5605 TREE_OPERAND (lhs, 1));
5608 /* Handle (a ? b : c) used as an "lvalue". */
5611 /* Produce (a ? (b = rhs) : (c = rhs))
5612 except that the RHS goes through a save-expr
5613 so the code to compute it is only emitted once. */
5615 tree preeval = NULL_TREE;
5617 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5619 error ("void value not ignored as it ought to be");
5620 return error_mark_node;
5623 rhs = stabilize_expr (rhs, &preeval);
5625 /* Check this here to avoid odd errors when trying to convert
5626 a throw to the type of the COND_EXPR. */
5627 if (!lvalue_or_else (lhs, lv_assign))
5628 return error_mark_node;
5630 cond = build_conditional_expr
5631 (TREE_OPERAND (lhs, 0),
5632 build_modify_expr (TREE_OPERAND (lhs, 1),
5634 build_modify_expr (TREE_OPERAND (lhs, 2),
5637 if (cond == error_mark_node)
5639 /* Make sure the code to compute the rhs comes out
5640 before the split. */
5642 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5650 if (modifycode == INIT_EXPR)
5652 if (TREE_CODE (rhs) == CONSTRUCTOR)
5654 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5655 /* Call convert to generate an error; see PR 11063. */
5656 rhs = convert (lhstype, rhs);
5657 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5658 TREE_SIDE_EFFECTS (result) = 1;
5661 else if (! IS_AGGR_TYPE (lhstype))
5662 /* Do the default thing. */;
5665 result = build_special_member_call (lhs, complete_ctor_identifier,
5666 build_tree_list (NULL_TREE, rhs),
5667 lhstype, LOOKUP_NORMAL);
5668 if (result == NULL_TREE)
5669 return error_mark_node;
5675 lhs = require_complete_type (lhs);
5676 if (lhs == error_mark_node)
5677 return error_mark_node;
5679 if (modifycode == NOP_EXPR)
5681 /* `operator=' is not an inheritable operator. */
5682 if (! IS_AGGR_TYPE (lhstype))
5683 /* Do the default thing. */;
5686 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5687 lhs, rhs, make_node (NOP_EXPR),
5688 /*overloaded_p=*/NULL);
5689 if (result == NULL_TREE)
5690 return error_mark_node;
5697 /* A binary op has been requested. Combine the old LHS
5698 value with the RHS producing the value we should actually
5699 store into the LHS. */
5701 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5702 lhs = stabilize_reference (lhs);
5703 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5704 if (newrhs == error_mark_node)
5706 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5707 TREE_TYPE (lhs), TREE_TYPE (rhs));
5708 return error_mark_node;
5711 /* Now it looks like a plain assignment. */
5712 modifycode = NOP_EXPR;
5714 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5715 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5718 /* The left-hand side must be an lvalue. */
5719 if (!lvalue_or_else (lhs, lv_assign))
5720 return error_mark_node;
5722 /* Warn about modifying something that is `const'. Don't warn if
5723 this is initialization. */
5724 if (modifycode != INIT_EXPR
5725 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5726 /* Functions are not modifiable, even though they are
5728 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5729 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5730 /* If it's an aggregate and any field is const, then it is
5731 effectively const. */
5732 || (CLASS_TYPE_P (lhstype)
5733 && C_TYPE_FIELDS_READONLY (lhstype))))
5734 readonly_error (lhs, "assignment", 0);
5736 /* If storing into a structure or union member, it has probably been
5737 given type `int'. Compute the type that would go with the actual
5738 amount of storage the member occupies. */
5740 if (TREE_CODE (lhs) == COMPONENT_REF
5741 && (TREE_CODE (lhstype) == INTEGER_TYPE
5742 || TREE_CODE (lhstype) == REAL_TYPE
5743 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5745 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5747 /* If storing in a field that is in actuality a short or narrower
5748 than one, we must store in the field in its actual type. */
5750 if (lhstype != TREE_TYPE (lhs))
5752 /* Avoid warnings converting integral types back into enums for
5754 if (TREE_CODE (lhstype) == INTEGER_TYPE
5755 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5757 if (TREE_SIDE_EFFECTS (lhs))
5758 lhs = stabilize_reference (lhs);
5761 lhs = copy_node (lhs);
5762 TREE_TYPE (lhs) = lhstype;
5766 /* Convert new value to destination type. */
5768 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5772 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5773 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5775 error ("incompatible types in assignment of %qT to %qT",
5776 TREE_TYPE (rhs), lhstype);
5777 return error_mark_node;
5780 /* Allow array assignment in compiler-generated code. */
5781 if (! DECL_ARTIFICIAL (current_function_decl))
5783 /* This routine is used for both initialization and assignment.
5784 Make sure the diagnostic message differentiates the context. */
5785 if (modifycode == INIT_EXPR)
5786 error ("array used as initializer");
5788 error ("invalid array assignment");
5789 return error_mark_node;
5792 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5793 ? 1 + (modifycode != INIT_EXPR): 0;
5794 return build_vec_init (lhs, NULL_TREE, newrhs,
5795 /*explicit_default_init_p=*/false,
5799 if (modifycode == INIT_EXPR)
5800 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5801 "initialization", NULL_TREE, 0);
5804 /* Avoid warnings on enum bit fields. */
5805 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5806 && TREE_CODE (lhstype) == INTEGER_TYPE)
5808 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5810 newrhs = convert_force (lhstype, newrhs, 0);
5813 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5815 if (TREE_CODE (newrhs) == CALL_EXPR
5816 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5817 newrhs = build_cplus_new (lhstype, newrhs);
5819 /* Can't initialize directly from a TARGET_EXPR, since that would
5820 cause the lhs to be constructed twice, and possibly result in
5821 accidental self-initialization. So we force the TARGET_EXPR to be
5822 expanded without a target. */
5823 if (TREE_CODE (newrhs) == TARGET_EXPR)
5824 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5825 TREE_OPERAND (newrhs, 0));
5828 if (newrhs == error_mark_node)
5829 return error_mark_node;
5831 if (c_dialect_objc () && flag_objc_gc)
5833 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5839 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5840 lhstype, lhs, newrhs);
5842 TREE_SIDE_EFFECTS (result) = 1;
5844 TREE_NO_WARNING (result) = 1;
5846 /* If we got the LHS in a different type for storing in,
5847 convert the result back to the nominal type of LHS
5848 so that the value we return always has the same type
5849 as the LHS argument. */
5851 if (olhstype == TREE_TYPE (result))
5855 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5856 TREE_NO_WARNING (result) = 1;
5859 return convert_for_assignment (olhstype, result, "assignment",
5864 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5866 if (processing_template_decl)
5867 return build_min_nt (MODOP_EXPR, lhs,
5868 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5870 if (modifycode != NOP_EXPR)
5872 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5873 make_node (modifycode),
5874 /*overloaded_p=*/NULL);
5877 TREE_NO_WARNING (rval) = 1;
5881 return build_modify_expr (lhs, modifycode, rhs);
5885 /* Get difference in deltas for different pointer to member function
5886 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5887 the conversion is invalid, the constant is zero. If
5888 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5889 If C_CAST_P is true this conversion is taking place as part of a
5892 Note that the naming of FROM and TO is kind of backwards; the return
5893 value is what we add to a TO in order to get a FROM. They are named
5894 this way because we call this function to find out how to convert from
5895 a pointer to member of FROM to a pointer to member of TO. */
5898 get_delta_difference (tree from, tree to,
5899 bool allow_inverse_p,
5906 /* Assume no conversion is required. */
5907 result = integer_zero_node;
5908 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5909 if (kind == bk_inaccessible || kind == bk_ambig)
5910 error (" in pointer to member function conversion");
5913 if (kind != bk_via_virtual)
5914 result = BINFO_OFFSET (binfo);
5917 tree virt_binfo = binfo_from_vbase (binfo);
5919 /* This is a reinterpret cast, we choose to do nothing. */
5920 if (allow_inverse_p)
5921 warning (0, "pointer to member cast via virtual base %qT",
5922 BINFO_TYPE (virt_binfo));
5924 error ("pointer to member conversion via virtual base %qT",
5925 BINFO_TYPE (virt_binfo));
5928 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5929 /* Pointer to member of incomplete class is permitted*/;
5930 else if (!allow_inverse_p)
5932 error_not_base_type (from, to);
5933 error (" in pointer to member conversion");
5937 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5940 if (kind != bk_via_virtual)
5941 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5944 /* This is a reinterpret cast, we choose to do nothing. */
5945 tree virt_binfo = binfo_from_vbase (binfo);
5947 warning (0, "pointer to member cast via virtual base %qT",
5948 BINFO_TYPE (virt_binfo));
5953 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5957 /* Return a constructor for the pointer-to-member-function TYPE using
5958 the other components as specified. */
5961 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5966 VEC(constructor_elt, gc) *v;
5968 /* Pull the FIELD_DECLs out of the type. */
5969 pfn_field = TYPE_FIELDS (type);
5970 delta_field = TREE_CHAIN (pfn_field);
5972 /* Make sure DELTA has the type we want. */
5973 delta = convert_and_check (delta_type_node, delta);
5975 /* Finish creating the initializer. */
5976 v = VEC_alloc(constructor_elt, gc, 2);
5977 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
5978 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
5979 u = build_constructor (type, v);
5980 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5981 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5982 TREE_STATIC (u) = (TREE_CONSTANT (u)
5983 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5985 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5990 /* Build a constructor for a pointer to member function. It can be
5991 used to initialize global variables, local variable, or used
5992 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5995 If FORCE is nonzero, then force this conversion, even if
5996 we would rather not do it. Usually set when using an explicit
5997 cast. A C-style cast is being processed iff C_CAST_P is true.
5999 Return error_mark_node, if something goes wrong. */
6002 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6008 if (error_operand_p (pfn))
6009 return error_mark_node;
6011 pfn_type = TREE_TYPE (pfn);
6012 to_type = build_ptrmemfunc_type (type);
6014 /* Handle multiple conversions of pointer to member functions. */
6015 if (TYPE_PTRMEMFUNC_P (pfn_type))
6017 tree delta = NULL_TREE;
6018 tree npfn = NULL_TREE;
6022 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6023 error ("invalid conversion to type %qT from type %qT",
6026 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6027 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6031 /* We don't have to do any conversion to convert a
6032 pointer-to-member to its own type. But, we don't want to
6033 just return a PTRMEM_CST if there's an explicit cast; that
6034 cast should make the expression an invalid template argument. */
6035 if (TREE_CODE (pfn) != PTRMEM_CST)
6037 if (same_type_p (to_type, pfn_type))
6039 else if (integer_zerop (n))
6040 return build_reinterpret_cast (to_type, pfn);
6043 if (TREE_SIDE_EFFECTS (pfn))
6044 pfn = save_expr (pfn);
6046 /* Obtain the function pointer and the current DELTA. */
6047 if (TREE_CODE (pfn) == PTRMEM_CST)
6048 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6051 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6052 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6055 /* Just adjust the DELTA field. */
6056 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6057 (TREE_TYPE (delta), ptrdiff_type_node));
6058 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6059 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6060 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6061 return build_ptrmemfunc1 (to_type, delta, npfn);
6064 /* Handle null pointer to member function conversions. */
6065 if (integer_zerop (pfn))
6067 pfn = build_c_cast (type, integer_zero_node);
6068 return build_ptrmemfunc1 (to_type,
6073 if (type_unknown_p (pfn))
6074 return instantiate_type (type, pfn, tf_warning_or_error);
6076 fn = TREE_OPERAND (pfn, 0);
6077 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6078 /* In a template, we will have preserved the
6080 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6081 return make_ptrmem_cst (to_type, fn);
6084 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6087 ??? There is no consistency as to the types returned for the above
6088 values. Some code acts as if it were a sizetype and some as if it were
6089 integer_type_node. */
6092 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6094 tree type = TREE_TYPE (cst);
6095 tree fn = PTRMEM_CST_MEMBER (cst);
6096 tree ptr_class, fn_class;
6098 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6100 /* The class that the function belongs to. */
6101 fn_class = DECL_CONTEXT (fn);
6103 /* The class that we're creating a pointer to member of. */
6104 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6106 /* First, calculate the adjustment to the function's class. */
6107 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6110 if (!DECL_VIRTUAL_P (fn))
6111 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6114 /* If we're dealing with a virtual function, we have to adjust 'this'
6115 again, to point to the base which provides the vtable entry for
6116 fn; the call will do the opposite adjustment. */
6117 tree orig_class = DECL_CONTEXT (fn);
6118 tree binfo = binfo_or_else (orig_class, fn_class);
6119 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6120 *delta, BINFO_OFFSET (binfo));
6121 *delta = fold_if_not_in_template (*delta);
6123 /* We set PFN to the vtable offset at which the function can be
6124 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6125 case delta is shifted left, and then incremented). */
6126 *pfn = DECL_VINDEX (fn);
6127 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6128 TYPE_SIZE_UNIT (vtable_entry_type));
6129 *pfn = fold_if_not_in_template (*pfn);
6131 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6133 case ptrmemfunc_vbit_in_pfn:
6134 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6136 *pfn = fold_if_not_in_template (*pfn);
6139 case ptrmemfunc_vbit_in_delta:
6140 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6141 *delta, integer_one_node);
6142 *delta = fold_if_not_in_template (*delta);
6143 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6144 *delta, integer_one_node);
6145 *delta = fold_if_not_in_template (*delta);
6152 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6153 *pfn = fold_if_not_in_template (*pfn);
6157 /* Return an expression for PFN from the pointer-to-member function
6161 pfn_from_ptrmemfunc (tree t)
6163 if (TREE_CODE (t) == PTRMEM_CST)
6168 expand_ptrmemfunc_cst (t, &delta, &pfn);
6173 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6176 /* Convert value RHS to type TYPE as preparation for an assignment to
6177 an lvalue of type TYPE. ERRTYPE is a string to use in error
6178 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6179 are doing the conversion in order to pass the PARMNUMth argument of
6183 convert_for_assignment (tree type, tree rhs,
6184 const char *errtype, tree fndecl, int parmnum)
6187 enum tree_code coder;
6189 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6190 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6191 rhs = TREE_OPERAND (rhs, 0);
6193 rhstype = TREE_TYPE (rhs);
6194 coder = TREE_CODE (rhstype);
6196 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6197 && vector_types_convertible_p (type, rhstype))
6198 return convert (type, rhs);
6200 if (rhs == error_mark_node || rhstype == error_mark_node)
6201 return error_mark_node;
6202 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6203 return error_mark_node;
6205 /* The RHS of an assignment cannot have void type. */
6206 if (coder == VOID_TYPE)
6208 error ("void value not ignored as it ought to be");
6209 return error_mark_node;
6212 /* Simplify the RHS if possible. */
6213 if (TREE_CODE (rhs) == CONST_DECL)
6214 rhs = DECL_INITIAL (rhs);
6216 if (c_dialect_objc ())
6219 tree rname = fndecl;
6221 if (!strcmp (errtype, "assignment"))
6223 else if (!strcmp (errtype, "initialization"))
6227 tree selector = objc_message_selector ();
6231 if (selector && parmno > 1)
6238 if (objc_compare_types (type, rhstype, parmno, rname))
6239 return convert (type, rhs);
6244 The expression is implicitly converted (clause _conv_) to the
6245 cv-unqualified type of the left operand.
6247 We allow bad conversions here because by the time we get to this point
6248 we are committed to doing the conversion. If we end up doing a bad
6249 conversion, convert_like will complain. */
6250 if (!can_convert_arg_bad (type, rhstype, rhs))
6252 /* When -Wno-pmf-conversions is use, we just silently allow
6253 conversions from pointers-to-members to plain pointers. If
6254 the conversion doesn't work, cp_convert will complain. */
6256 && TYPE_PTR_P (type)
6257 && TYPE_PTRMEMFUNC_P (rhstype))
6258 rhs = cp_convert (strip_top_quals (type), rhs);
6261 /* If the right-hand side has unknown type, then it is an
6262 overloaded function. Call instantiate_type to get error
6264 if (rhstype == unknown_type_node)
6265 instantiate_type (type, rhs, tf_warning_or_error);
6267 error ("cannot convert %qT to %qT for argument %qP to %qD",
6268 rhstype, type, parmnum, fndecl);
6270 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6271 return error_mark_node;
6274 if (warn_missing_format_attribute)
6276 const enum tree_code codel = TREE_CODE (type);
6277 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6279 && check_missing_format_attribute (type, rhstype))
6280 warning (OPT_Wmissing_format_attribute,
6281 "%s might be a candidate for a format attribute",
6285 return perform_implicit_conversion (strip_top_quals (type), rhs);
6288 /* Convert RHS to be of type TYPE.
6289 If EXP is nonzero, it is the target of the initialization.
6290 ERRTYPE is a string to use in error messages.
6292 Two major differences between the behavior of
6293 `convert_for_assignment' and `convert_for_initialization'
6294 are that references are bashed in the former, while
6295 copied in the latter, and aggregates are assigned in
6296 the former (operator=) while initialized in the
6299 If using constructor make sure no conversion operator exists, if one does
6300 exist, an ambiguity exists.
6302 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6305 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6306 const char *errtype, tree fndecl, int parmnum)
6308 enum tree_code codel = TREE_CODE (type);
6310 enum tree_code coder;
6312 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6313 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6314 if (TREE_CODE (rhs) == NOP_EXPR
6315 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6316 && codel != REFERENCE_TYPE)
6317 rhs = TREE_OPERAND (rhs, 0);
6319 if (type == error_mark_node
6320 || rhs == error_mark_node
6321 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6322 return error_mark_node;
6324 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6325 && TREE_CODE (type) != ARRAY_TYPE
6326 && (TREE_CODE (type) != REFERENCE_TYPE
6327 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6328 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6329 && (TREE_CODE (type) != REFERENCE_TYPE
6330 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6331 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6332 rhs = decay_conversion (rhs);
6334 rhstype = TREE_TYPE (rhs);
6335 coder = TREE_CODE (rhstype);
6337 if (coder == ERROR_MARK)
6338 return error_mark_node;
6340 /* We accept references to incomplete types, so we can
6341 return here before checking if RHS is of complete type. */
6343 if (codel == REFERENCE_TYPE)
6345 /* This should eventually happen in convert_arguments. */
6346 int savew = 0, savee = 0;
6349 savew = warningcount, savee = errorcount;
6350 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6354 if (warningcount > savew)
6355 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6356 else if (errorcount > savee)
6357 error ("in passing argument %P of %q+D", parmnum, fndecl);
6363 exp = require_complete_type (exp);
6364 if (exp == error_mark_node)
6365 return error_mark_node;
6367 rhstype = non_reference (rhstype);
6369 type = complete_type (type);
6371 if (IS_AGGR_TYPE (type))
6372 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6374 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6377 /* If RETVAL is the address of, or a reference to, a local variable or
6378 temporary give an appropriate warning. */
6381 maybe_warn_about_returning_address_of_local (tree retval)
6383 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6384 tree whats_returned = retval;
6388 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6389 whats_returned = TREE_OPERAND (whats_returned, 1);
6390 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6391 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6392 || TREE_CODE (whats_returned) == NOP_EXPR)
6393 whats_returned = TREE_OPERAND (whats_returned, 0);
6398 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6400 whats_returned = TREE_OPERAND (whats_returned, 0);
6402 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6404 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6405 || TREE_CODE (whats_returned) == TARGET_EXPR)
6407 warning (0, "returning reference to temporary");
6410 if (TREE_CODE (whats_returned) == VAR_DECL
6411 && DECL_NAME (whats_returned)
6412 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6414 warning (0, "reference to non-lvalue returned");
6419 while (TREE_CODE (whats_returned) == COMPONENT_REF
6420 || TREE_CODE (whats_returned) == ARRAY_REF)
6421 whats_returned = TREE_OPERAND (whats_returned, 0);
6423 if (DECL_P (whats_returned)
6424 && DECL_NAME (whats_returned)
6425 && DECL_FUNCTION_SCOPE_P (whats_returned)
6426 && !(TREE_STATIC (whats_returned)
6427 || TREE_PUBLIC (whats_returned)))
6429 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6430 warning (0, "reference to local variable %q+D returned",
6433 warning (0, "address of local variable %q+D returned",
6439 /* Check that returning RETVAL from the current function is valid.
6440 Return an expression explicitly showing all conversions required to
6441 change RETVAL into the function return type, and to assign it to
6442 the DECL_RESULT for the function. Set *NO_WARNING to true if
6443 code reaches end of non-void function warning shouldn't be issued
6444 on this RETURN_EXPR. */
6447 check_return_expr (tree retval, bool *no_warning)
6450 /* The type actually returned by the function, after any
6453 int fn_returns_value_p;
6455 *no_warning = false;
6457 /* A `volatile' function is one that isn't supposed to return, ever.
6458 (This is a G++ extension, used to get better code for functions
6459 that call the `volatile' function.) */
6460 if (TREE_THIS_VOLATILE (current_function_decl))
6461 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6463 /* Check for various simple errors. */
6464 if (DECL_DESTRUCTOR_P (current_function_decl))
6467 error ("returning a value from a destructor");
6470 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6472 if (in_function_try_handler)
6473 /* If a return statement appears in a handler of the
6474 function-try-block of a constructor, the program is ill-formed. */
6475 error ("cannot return from a handler of a function-try-block of a constructor");
6477 /* You can't return a value from a constructor. */
6478 error ("returning a value from a constructor");
6482 if (processing_template_decl)
6484 current_function_returns_value = 1;
6488 /* When no explicit return-value is given in a function with a named
6489 return value, the named return value is used. */
6490 result = DECL_RESULT (current_function_decl);
6491 valtype = TREE_TYPE (result);
6492 gcc_assert (valtype != NULL_TREE);
6493 fn_returns_value_p = !VOID_TYPE_P (valtype);
6494 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6497 /* Check for a return statement with no return value in a function
6498 that's supposed to return a value. */
6499 if (!retval && fn_returns_value_p)
6501 pedwarn ("return-statement with no value, in function returning %qT",
6503 /* Clear this, so finish_function won't say that we reach the
6504 end of a non-void function (which we don't, we gave a
6506 current_function_returns_null = 0;
6507 /* And signal caller that TREE_NO_WARNING should be set on the
6508 RETURN_EXPR to avoid control reaches end of non-void function
6509 warnings in tree-cfg.c. */
6512 /* Check for a return statement with a value in a function that
6513 isn't supposed to return a value. */
6514 else if (retval && !fn_returns_value_p)
6516 if (VOID_TYPE_P (TREE_TYPE (retval)))
6517 /* You can return a `void' value from a function of `void'
6518 type. In that case, we have to evaluate the expression for
6519 its side-effects. */
6520 finish_expr_stmt (retval);
6522 pedwarn ("return-statement with a value, in function "
6523 "returning 'void'");
6525 current_function_returns_null = 1;
6527 /* There's really no value to return, after all. */
6531 /* Remember that this function can sometimes return without a
6533 current_function_returns_null = 1;
6535 /* Remember that this function did return a value. */
6536 current_function_returns_value = 1;
6538 /* Check for erroneous operands -- but after giving ourselves a
6539 chance to provide an error about returning a value from a void
6541 if (error_operand_p (retval))
6543 current_function_return_value = error_mark_node;
6544 return error_mark_node;
6547 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6548 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6549 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6550 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6552 && null_ptr_cst_p (retval))
6553 warning (0, "%<operator new%> must not return NULL unless it is "
6554 "declared %<throw()%> (or -fcheck-new is in effect)");
6556 /* Effective C++ rule 15. See also start_function. */
6558 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6562 /* The function return type must be a reference to the current
6564 if (TREE_CODE (valtype) == REFERENCE_TYPE
6565 && same_type_ignoring_top_level_qualifiers_p
6566 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6568 /* Returning '*this' is obviously OK. */
6569 if (retval == current_class_ref)
6571 /* If we are calling a function whose return type is the same of
6572 the current class reference, it is ok. */
6573 else if (TREE_CODE (retval) == INDIRECT_REF
6574 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6579 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6582 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6584 [...] For a function with a class return type, if the expression
6585 in the return statement is the name of a local object, and the cv-
6586 unqualified type of the local object is the same as the function
6587 return type, an implementation is permitted to omit creating the tem-
6588 porary object to hold the function return value [...]
6590 So, if this is a value-returning function that always returns the same
6591 local variable, remember it.
6593 It might be nice to be more flexible, and choose the first suitable
6594 variable even if the function sometimes returns something else, but
6595 then we run the risk of clobbering the variable we chose if the other
6596 returned expression uses the chosen variable somehow. And people expect
6597 this restriction, anyway. (jason 2000-11-19)
6599 See finish_function and finalize_nrv for the rest of this optimization. */
6601 if (fn_returns_value_p && flag_elide_constructors)
6603 if (retval != NULL_TREE
6604 && (current_function_return_value == NULL_TREE
6605 || current_function_return_value == retval)
6606 && TREE_CODE (retval) == VAR_DECL
6607 && DECL_CONTEXT (retval) == current_function_decl
6608 && ! TREE_STATIC (retval)
6609 && (DECL_ALIGN (retval)
6610 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6611 && same_type_p ((TYPE_MAIN_VARIANT
6612 (TREE_TYPE (retval))),
6614 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6615 current_function_return_value = retval;
6617 current_function_return_value = error_mark_node;
6620 /* We don't need to do any conversions when there's nothing being
6625 /* Do any required conversions. */
6626 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6627 /* No conversions are required. */
6631 /* The type the function is declared to return. */
6632 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6634 /* The functype's return type will have been set to void, if it
6635 was an incomplete type. Just treat this as 'return;' */
6636 if (VOID_TYPE_P (functype))
6637 return error_mark_node;
6639 /* First convert the value to the function's return type, then
6640 to the type of return value's location to handle the
6641 case that functype is smaller than the valtype. */
6642 retval = convert_for_initialization
6643 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6644 "return", NULL_TREE, 0);
6645 retval = convert (valtype, retval);
6647 /* If the conversion failed, treat this just like `return;'. */
6648 if (retval == error_mark_node)
6650 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6651 else if (! current_function_returns_struct
6652 && TREE_CODE (retval) == TARGET_EXPR
6653 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6654 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6655 TREE_OPERAND (retval, 0));
6657 maybe_warn_about_returning_address_of_local (retval);
6660 /* Actually copy the value returned into the appropriate location. */
6661 if (retval && retval != result)
6662 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6668 /* Returns nonzero if the pointer-type FROM can be converted to the
6669 pointer-type TO via a qualification conversion. If CONSTP is -1,
6670 then we return nonzero if the pointers are similar, and the
6671 cv-qualification signature of FROM is a proper subset of that of TO.
6673 If CONSTP is positive, then all outer pointers have been
6677 comp_ptr_ttypes_real (tree to, tree from, int constp)
6679 bool to_more_cv_qualified = false;
6681 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6683 if (TREE_CODE (to) != TREE_CODE (from))
6686 if (TREE_CODE (from) == OFFSET_TYPE
6687 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6688 TYPE_OFFSET_BASETYPE (to)))
6691 /* Const and volatile mean something different for function types,
6692 so the usual checks are not appropriate. */
6693 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6695 /* In Objective-C++, some types may have been 'volatilized' by
6696 the compiler for EH; when comparing them here, the volatile
6697 qualification must be ignored. */
6698 bool objc_quals_match = objc_type_quals_match (to, from);
6700 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6703 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6707 to_more_cv_qualified = true;
6711 constp &= TYPE_READONLY (to);
6714 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6715 return ((constp >= 0 || to_more_cv_qualified)
6716 && same_type_ignoring_top_level_qualifiers_p (to, from));
6720 /* When comparing, say, char ** to char const **, this function takes
6721 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6722 types to this function. */
6725 comp_ptr_ttypes (tree to, tree from)
6727 return comp_ptr_ttypes_real (to, from, 1);
6730 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6731 type or inheritance-related types, regardless of cv-quals. */
6734 ptr_reasonably_similar (tree to, tree from)
6736 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6738 /* Any target type is similar enough to void. */
6739 if (TREE_CODE (to) == VOID_TYPE
6740 || TREE_CODE (from) == VOID_TYPE)
6743 if (TREE_CODE (to) != TREE_CODE (from))
6746 if (TREE_CODE (from) == OFFSET_TYPE
6747 && comptypes (TYPE_OFFSET_BASETYPE (to),
6748 TYPE_OFFSET_BASETYPE (from),
6749 COMPARE_BASE | COMPARE_DERIVED))
6752 if (TREE_CODE (to) == VECTOR_TYPE
6753 && vector_types_convertible_p (to, from))
6756 if (TREE_CODE (to) == INTEGER_TYPE
6757 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6760 if (TREE_CODE (to) == FUNCTION_TYPE)
6763 if (TREE_CODE (to) != POINTER_TYPE)
6765 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6766 COMPARE_BASE | COMPARE_DERIVED);
6770 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6771 pointer-to-member types) are the same, ignoring cv-qualification at
6775 comp_ptr_ttypes_const (tree to, tree from)
6777 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6779 if (TREE_CODE (to) != TREE_CODE (from))
6782 if (TREE_CODE (from) == OFFSET_TYPE
6783 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6784 TYPE_OFFSET_BASETYPE (to)))
6787 if (TREE_CODE (to) != POINTER_TYPE)
6788 return same_type_ignoring_top_level_qualifiers_p (to, from);
6792 /* Returns the type qualifiers for this type, including the qualifiers on the
6793 elements for an array type. */
6796 cp_type_quals (tree type)
6798 type = strip_array_types (type);
6799 if (type == error_mark_node)
6800 return TYPE_UNQUALIFIED;
6801 return TYPE_QUALS (type);
6804 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6808 cp_type_readonly (tree type)
6810 type = strip_array_types (type);
6811 return TYPE_READONLY (type);
6814 /* Returns nonzero if the TYPE contains a mutable member. */
6817 cp_has_mutable_p (tree type)
6819 type = strip_array_types (type);
6821 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6824 /* Apply the TYPE_QUALS to the new DECL. */
6826 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6828 tree type = TREE_TYPE (decl);
6830 if (type == error_mark_node)
6833 if (TREE_CODE (type) == FUNCTION_TYPE
6834 && type_quals != TYPE_UNQUALIFIED)
6836 /* This was an error in C++98 (cv-qualifiers cannot be added to
6837 a function type), but DR 295 makes the code well-formed by
6838 dropping the extra qualifiers. */
6841 tree bad_type = build_qualified_type (type, type_quals);
6842 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6846 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6850 /* Avoid setting TREE_READONLY incorrectly. */
6851 if (/* If the object has a constructor, the constructor may modify
6853 TYPE_NEEDS_CONSTRUCTING (type)
6854 /* If the type isn't complete, we don't know yet if it will need
6856 || !COMPLETE_TYPE_P (type)
6857 /* If the type has a mutable component, that component might be
6859 || TYPE_HAS_MUTABLE_P (type))
6860 type_quals &= ~TYPE_QUAL_CONST;
6862 c_apply_type_quals_to_decl (type_quals, decl);
6865 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6866 exemplar types such that casting T1 to T2 is casting away constness
6867 if and only if there is no implicit conversion from T1 to T2. */
6870 casts_away_constness_r (tree *t1, tree *t2)
6875 /* [expr.const.cast]
6877 For multi-level pointer to members and multi-level mixed pointers
6878 and pointers to members (conv.qual), the "member" aspect of a
6879 pointer to member level is ignored when determining if a const
6880 cv-qualifier has been cast away. */
6881 /* [expr.const.cast]
6883 For two pointer types:
6885 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6886 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6889 casting from X1 to X2 casts away constness if, for a non-pointer
6890 type T there does not exist an implicit conversion (clause
6893 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6897 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6898 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6899 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6901 *t1 = cp_build_qualified_type (void_type_node,
6902 cp_type_quals (*t1));
6903 *t2 = cp_build_qualified_type (void_type_node,
6904 cp_type_quals (*t2));
6908 quals1 = cp_type_quals (*t1);
6909 quals2 = cp_type_quals (*t2);
6911 if (TYPE_PTRMEM_P (*t1))
6912 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6914 *t1 = TREE_TYPE (*t1);
6915 if (TYPE_PTRMEM_P (*t2))
6916 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6918 *t2 = TREE_TYPE (*t2);
6920 casts_away_constness_r (t1, t2);
6921 *t1 = build_pointer_type (*t1);
6922 *t2 = build_pointer_type (*t2);
6923 *t1 = cp_build_qualified_type (*t1, quals1);
6924 *t2 = cp_build_qualified_type (*t2, quals2);
6927 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6931 casts_away_constness (tree t1, tree t2)
6933 if (TREE_CODE (t2) == REFERENCE_TYPE)
6935 /* [expr.const.cast]
6937 Casting from an lvalue of type T1 to an lvalue of type T2
6938 using a reference cast casts away constness if a cast from an
6939 rvalue of type "pointer to T1" to the type "pointer to T2"
6940 casts away constness. */
6941 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6942 return casts_away_constness (build_pointer_type (t1),
6943 build_pointer_type (TREE_TYPE (t2)));
6946 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6947 /* [expr.const.cast]
6949 Casting from an rvalue of type "pointer to data member of X
6950 of type T1" to the type "pointer to data member of Y of type
6951 T2" casts away constness if a cast from an rvalue of type
6952 "pointer to T1" to the type "pointer to T2" casts away
6954 return casts_away_constness
6955 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6956 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6958 /* Casting away constness is only something that makes sense for
6959 pointer or reference types. */
6960 if (TREE_CODE (t1) != POINTER_TYPE
6961 || TREE_CODE (t2) != POINTER_TYPE)
6964 /* Top-level qualifiers don't matter. */
6965 t1 = TYPE_MAIN_VARIANT (t1);
6966 t2 = TYPE_MAIN_VARIANT (t2);
6967 casts_away_constness_r (&t1, &t2);
6968 if (!can_convert (t2, t1))
6974 /* If T is a REFERENCE_TYPE return the type to which T refers.
6975 Otherwise, return T itself. */
6978 non_reference (tree t)
6980 if (TREE_CODE (t) == REFERENCE_TYPE)
6986 /* Return nonzero if REF is an lvalue valid for this language;
6987 otherwise, print an error message and return zero. USE says
6988 how the lvalue is being used and so selects the error message. */
6991 lvalue_or_else (tree ref, enum lvalue_use use)
6993 int win = lvalue_p (ref);