1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
5 Hacked by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 /* This file is part of the C++ front end.
26 It contains routines to build C++ expressions given their operands,
27 including computing the types of the result, C and C++ specific error
28 checks, and some optimization. */
32 #include "coretypes.h"
42 #include "diagnostic.h"
49 static tree pfn_from_ptrmemfunc (tree);
50 static tree convert_for_assignment (tree, tree, const char *, tree, int);
51 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
52 static tree rationalize_conditional_expr (enum tree_code, tree);
53 static int comp_ptr_ttypes_real (tree, tree, int);
54 static bool comp_except_types (tree, tree, bool);
55 static bool comp_array_types (tree, tree, bool);
56 static tree pointer_diff (tree, tree, tree);
57 static tree get_delta_difference (tree, tree, bool, bool);
58 static void casts_away_constness_r (tree *, tree *);
59 static bool casts_away_constness (tree, tree);
60 static void maybe_warn_about_returning_address_of_local (tree);
61 static tree lookup_destructor (tree, tree, tree);
62 static int convert_arguments (int, tree *, tree, tree, tree, int);
64 /* Do `exp = require_complete_type (exp);' to make sure exp
65 does not have an incomplete type. (That includes void types.)
66 Returns the error_mark_node if the VALUE does not have
67 complete type when this function returns. */
70 require_complete_type (tree value)
74 if (processing_template_decl || value == error_mark_node)
77 if (TREE_CODE (value) == OVERLOAD)
78 type = unknown_type_node;
80 type = TREE_TYPE (value);
82 if (type == error_mark_node)
83 return error_mark_node;
85 /* First, detect a valid value with a complete type. */
86 if (COMPLETE_TYPE_P (type))
89 if (complete_type_or_else (type, value))
92 return error_mark_node;
95 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
96 a template instantiation, do the instantiation. Returns TYPE,
97 whether or not it could be completed, unless something goes
98 horribly wrong, in which case the error_mark_node is returned. */
101 complete_type (tree type)
103 if (type == NULL_TREE)
104 /* Rather than crash, we return something sure to cause an error
106 return error_mark_node;
108 if (type == error_mark_node || COMPLETE_TYPE_P (type))
110 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
112 tree t = complete_type (TREE_TYPE (type));
113 unsigned int needs_constructing, has_nontrivial_dtor;
114 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
117 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
119 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
120 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
122 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
123 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
126 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
127 instantiate_class_template (TYPE_MAIN_VARIANT (type));
132 /* Like complete_type, but issue an error if the TYPE cannot be completed.
133 VALUE is used for informative diagnostics.
134 Returns NULL_TREE if the type cannot be made complete. */
137 complete_type_or_else (tree type, tree value)
139 type = complete_type (type);
140 if (type == error_mark_node)
141 /* We already issued an error. */
143 else if (!COMPLETE_TYPE_P (type))
145 cxx_incomplete_type_diagnostic (value, type, 0);
152 /* Return truthvalue of whether type of EXP is instantiated. */
155 type_unknown_p (tree exp)
157 return (TREE_CODE (exp) == TREE_LIST
158 || TREE_TYPE (exp) == unknown_type_node);
162 /* Return the common type of two parameter lists.
163 We assume that comptypes has already been done and returned 1;
164 if that isn't so, this may crash.
166 As an optimization, free the space we allocate if the parameter
167 lists are already common. */
170 commonparms (tree p1, tree p2)
172 tree oldargs = p1, newargs, n;
176 len = list_length (p1);
177 newargs = tree_last (p1);
179 if (newargs == void_list_node)
188 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
193 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
195 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
197 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
200 else if (! TREE_PURPOSE (p1))
202 if (TREE_PURPOSE (p2))
204 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
210 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
212 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
214 if (TREE_VALUE (p1) != TREE_VALUE (p2))
217 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
220 TREE_VALUE (n) = TREE_VALUE (p1);
228 /* Given a type, perhaps copied for a typedef,
229 find the "original" version of it. */
231 original_type (tree t)
233 int quals = cp_type_quals (t);
234 while (t != error_mark_node
235 && TYPE_NAME (t) != NULL_TREE)
237 tree x = TYPE_NAME (t);
238 if (TREE_CODE (x) != TYPE_DECL)
240 x = DECL_ORIGINAL_TYPE (x);
245 return cp_build_qualified_type (t, quals);
248 /* T1 and T2 are arithmetic or enumeration types. Return the type
249 that will result from the "usual arithmetic conversions" on T1 and
250 T2 as described in [expr]. */
253 type_after_usual_arithmetic_conversions (tree t1, tree t2)
255 enum tree_code code1 = TREE_CODE (t1);
256 enum tree_code code2 = TREE_CODE (t2);
259 /* FIXME: Attributes. */
260 gcc_assert (ARITHMETIC_TYPE_P (t1)
261 || TREE_CODE (t1) == VECTOR_TYPE
262 || TREE_CODE (t1) == ENUMERAL_TYPE);
263 gcc_assert (ARITHMETIC_TYPE_P (t2)
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 unsigned long long, then convert the other to unsigned
328 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
329 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
330 return build_type_attribute_variant (long_long_unsigned_type_node,
332 /* If one is a long long, and the other is an unsigned long, and
333 long long can represent all the values of an unsigned long, then
334 convert to a long long. Otherwise, convert to an unsigned long
335 long. Otherwise, if either operand is long long, convert the
338 Since we're here, we know the TYPE_PRECISION is the same;
339 therefore converting to long long cannot represent all the values
340 of an unsigned long, so we choose unsigned long long in that
342 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
343 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
345 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
346 ? long_long_unsigned_type_node
347 : long_long_integer_type_node);
348 return build_type_attribute_variant (t, attributes);
351 /* Go through the same procedure, but for longs. */
352 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
353 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
354 return build_type_attribute_variant (long_unsigned_type_node,
356 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
357 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
359 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
360 ? long_unsigned_type_node : long_integer_type_node);
361 return build_type_attribute_variant (t, attributes);
363 /* Otherwise prefer the unsigned one. */
364 if (TYPE_UNSIGNED (t1))
365 return build_type_attribute_variant (t1, attributes);
367 return build_type_attribute_variant (t2, attributes);
371 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
372 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
373 return build_type_attribute_variant (long_double_type_node,
375 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
376 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
377 return build_type_attribute_variant (double_type_node,
379 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
380 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
381 return build_type_attribute_variant (float_type_node,
384 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
385 the standard C++ floating-point types. Logic earlier in this
386 function has already eliminated the possibility that
387 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
388 compelling reason to choose one or the other. */
389 return build_type_attribute_variant (t1, attributes);
393 /* Subroutine of composite_pointer_type to implement the recursive
394 case. See that function for documentation fo the parameters. */
397 composite_pointer_type_r (tree t1, tree t2, const char* location)
404 /* Determine the types pointed to by T1 and T2. */
405 if (TREE_CODE (t1) == POINTER_TYPE)
407 pointee1 = TREE_TYPE (t1);
408 pointee2 = TREE_TYPE (t2);
412 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
413 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
418 Otherwise, the composite pointer type is a pointer type
419 similar (_conv.qual_) to the type of one of the operands,
420 with a cv-qualification signature (_conv.qual_) that is the
421 union of the cv-qualification signatures of the operand
423 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
424 result_type = pointee1;
425 else if ((TREE_CODE (pointee1) == POINTER_TYPE
426 && TREE_CODE (pointee2) == POINTER_TYPE)
427 || (TYPE_PTR_TO_MEMBER_P (pointee1)
428 && TYPE_PTR_TO_MEMBER_P (pointee2)))
429 result_type = composite_pointer_type_r (pointee1, pointee2, location);
432 pedwarn ("%s between distinct pointer types %qT and %qT "
435 result_type = void_type_node;
437 result_type = cp_build_qualified_type (result_type,
438 (cp_type_quals (pointee1)
439 | cp_type_quals (pointee2)));
440 /* If the original types were pointers to members, so is the
442 if (TYPE_PTR_TO_MEMBER_P (t1))
444 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
445 TYPE_PTRMEM_CLASS_TYPE (t2)))
446 pedwarn ("%s between distinct pointer types %qT and %qT "
449 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
453 result_type = build_pointer_type (result_type);
455 /* Merge the attributes. */
456 attributes = (*targetm.merge_type_attributes) (t1, t2);
457 return build_type_attribute_variant (result_type, attributes);
460 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
461 ARG1 and ARG2 are the values with those types. The LOCATION is a
462 string describing the current location, in case an error occurs.
464 This routine also implements the computation of a common type for
465 pointers-to-members as per [expr.eq]. */
468 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
469 const char* location)
476 If one operand is a null pointer constant, the composite pointer
477 type is the type of the other operand. */
478 if (null_ptr_cst_p (arg1))
480 if (null_ptr_cst_p (arg2))
487 If one of the operands has type "pointer to cv1 void*", then
488 the other has type "pointer to cv2T", and the composite pointer
489 type is "pointer to cv12 void", where cv12 is the union of cv1
492 If either type is a pointer to void, make sure it is T1. */
493 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
501 /* Now, if T1 is a pointer to void, merge the qualifiers. */
502 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
507 if (pedantic && TYPE_PTRFN_P (t2))
508 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
509 "and pointer-to-function", location);
511 = cp_build_qualified_type (void_type_node,
512 (cp_type_quals (TREE_TYPE (t1))
513 | cp_type_quals (TREE_TYPE (t2))));
514 result_type = build_pointer_type (result_type);
515 /* Merge the attributes. */
516 attributes = (*targetm.merge_type_attributes) (t1, t2);
517 return build_type_attribute_variant (result_type, attributes);
520 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
521 && TREE_CODE (t2) == POINTER_TYPE)
523 if (objc_compare_types (t1, t2, -3, NULL_TREE))
527 /* [expr.eq] permits the application of a pointer conversion to
528 bring the pointers to a common type. */
529 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
530 && CLASS_TYPE_P (TREE_TYPE (t1))
531 && CLASS_TYPE_P (TREE_TYPE (t2))
532 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
535 class1 = TREE_TYPE (t1);
536 class2 = TREE_TYPE (t2);
538 if (DERIVED_FROM_P (class1, class2))
539 t2 = (build_pointer_type
540 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
541 else if (DERIVED_FROM_P (class2, class1))
542 t1 = (build_pointer_type
543 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
546 error ("%s between distinct pointer types %qT and %qT "
547 "lacks a cast", location, t1, t2);
548 return error_mark_node;
551 /* [expr.eq] permits the application of a pointer-to-member
552 conversion to change the class type of one of the types. */
553 else if (TYPE_PTR_TO_MEMBER_P (t1)
554 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
555 TYPE_PTRMEM_CLASS_TYPE (t2)))
557 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
558 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
560 if (DERIVED_FROM_P (class1, class2))
561 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
562 else if (DERIVED_FROM_P (class2, class1))
563 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
566 error ("%s between distinct pointer-to-member types %qT and %qT "
567 "lacks a cast", location, t1, t2);
568 return error_mark_node;
572 return composite_pointer_type_r (t1, t2, location);
575 /* Return the merged type of two types.
576 We assume that comptypes has already been done and returned 1;
577 if that isn't so, this may crash.
579 This just combines attributes and default arguments; any other
580 differences would cause the two types to compare unalike. */
583 merge_types (tree t1, tree t2)
585 enum tree_code code1;
586 enum tree_code code2;
589 /* Save time if the two types are the same. */
592 if (original_type (t1) == original_type (t2))
595 /* If one type is nonsense, use the other. */
596 if (t1 == error_mark_node)
598 if (t2 == error_mark_node)
601 /* Merge the attributes. */
602 attributes = (*targetm.merge_type_attributes) (t1, t2);
604 if (TYPE_PTRMEMFUNC_P (t1))
605 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
606 if (TYPE_PTRMEMFUNC_P (t2))
607 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
609 code1 = TREE_CODE (t1);
610 code2 = TREE_CODE (t2);
616 /* For two pointers, do this recursively on the target type. */
618 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
619 int quals = cp_type_quals (t1);
621 if (code1 == POINTER_TYPE)
622 t1 = build_pointer_type (target);
624 t1 = build_reference_type (target);
625 t1 = build_type_attribute_variant (t1, attributes);
626 t1 = cp_build_qualified_type (t1, quals);
628 if (TREE_CODE (target) == METHOD_TYPE)
629 t1 = build_ptrmemfunc_type (t1);
638 quals = cp_type_quals (t1);
639 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
640 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
641 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
643 t1 = cp_build_qualified_type (t1, quals);
649 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
650 /* Save space: see if the result is identical to one of the args. */
651 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
652 return build_type_attribute_variant (t1, attributes);
653 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
654 return build_type_attribute_variant (t2, attributes);
655 /* Merge the element types, and have a size if either arg has one. */
656 t1 = build_cplus_array_type
657 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
662 /* Function types: prefer the one that specified arg types.
663 If both do, merge the arg types. Also merge the return types. */
665 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
666 tree p1 = TYPE_ARG_TYPES (t1);
667 tree p2 = TYPE_ARG_TYPES (t2);
670 /* Save space: see if the result is identical to one of the args. */
671 if (valtype == TREE_TYPE (t1) && ! p2)
672 return cp_build_type_attribute_variant (t1, attributes);
673 if (valtype == TREE_TYPE (t2) && ! p1)
674 return cp_build_type_attribute_variant (t2, attributes);
676 /* Simple way if one arg fails to specify argument types. */
677 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
679 rval = build_function_type (valtype, p2);
680 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
681 rval = build_exception_variant (rval, raises);
682 return cp_build_type_attribute_variant (rval, attributes);
684 raises = TYPE_RAISES_EXCEPTIONS (t1);
685 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
687 rval = build_function_type (valtype, p1);
689 rval = build_exception_variant (rval, raises);
690 return cp_build_type_attribute_variant (rval, attributes);
693 rval = build_function_type (valtype, commonparms (p1, p2));
694 t1 = build_exception_variant (rval, raises);
700 /* Get this value the long way, since TYPE_METHOD_BASETYPE
701 is just the main variant of this. */
702 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
703 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
706 /* If this was a member function type, get back to the
707 original type of type member function (i.e., without
708 the class instance variable up front. */
709 t1 = build_function_type (TREE_TYPE (t1),
710 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
711 t2 = build_function_type (TREE_TYPE (t2),
712 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
713 t3 = merge_types (t1, t2);
714 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
715 TYPE_ARG_TYPES (t3));
716 t1 = build_exception_variant (t3, raises);
721 /* There is no need to merge attributes into a TYPENAME_TYPE.
722 When the type is instantiated it will have whatever
723 attributes result from the instantiation. */
729 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
731 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
734 return cp_build_type_attribute_variant (t1, attributes);
737 /* Return the common type of two types.
738 We assume that comptypes has already been done and returned 1;
739 if that isn't so, this may crash.
741 This is the type for the result of most arithmetic operations
742 if the operands have the given two types. */
745 common_type (tree t1, tree t2)
747 enum tree_code code1;
748 enum tree_code code2;
750 /* If one type is nonsense, bail. */
751 if (t1 == error_mark_node || t2 == error_mark_node)
752 return error_mark_node;
754 code1 = TREE_CODE (t1);
755 code2 = TREE_CODE (t2);
757 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
758 || code1 == VECTOR_TYPE)
759 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
760 || code2 == VECTOR_TYPE))
761 return type_after_usual_arithmetic_conversions (t1, t2);
763 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
764 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
765 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
766 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
772 /* Compare two exception specifier types for exactness or subsetness, if
773 allowed. Returns false for mismatch, true for match (same, or
776 [except.spec] "If a class X ... objects of class X or any class publicly
777 and unambiguously derived from X. Similarly, if a pointer type Y * ...
778 exceptions of type Y * or that are pointers to any type publicly and
779 unambiguously derived from Y. Otherwise a function only allows exceptions
780 that have the same type ..."
781 This does not mention cv qualifiers and is different to what throw
782 [except.throw] and catch [except.catch] will do. They will ignore the
783 top level cv qualifiers, and allow qualifiers in the pointer to class
786 We implement the letter of the standard. */
789 comp_except_types (tree a, tree b, bool exact)
791 if (same_type_p (a, b))
795 if (cp_type_quals (a) || cp_type_quals (b))
798 if (TREE_CODE (a) == POINTER_TYPE
799 && TREE_CODE (b) == POINTER_TYPE)
803 if (cp_type_quals (a) || cp_type_quals (b))
807 if (TREE_CODE (a) != RECORD_TYPE
808 || TREE_CODE (b) != RECORD_TYPE)
811 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
817 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
818 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
819 otherwise it must be exact. Exception lists are unordered, but
820 we've already filtered out duplicates. Most lists will be in order,
821 we should try to make use of that. */
824 comp_except_specs (tree t1, tree t2, bool exact)
833 if (t1 == NULL_TREE) /* T1 is ... */
834 return t2 == NULL_TREE || !exact;
835 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
836 return t2 != NULL_TREE && !TREE_VALUE (t2);
837 if (t2 == NULL_TREE) /* T2 is ... */
839 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
842 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
843 Count how many we find, to determine exactness. For exact matching and
844 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
846 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
848 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
850 tree a = TREE_VALUE (probe);
851 tree b = TREE_VALUE (t2);
853 if (comp_except_types (a, b, exact))
855 if (probe == base && exact)
856 base = TREE_CHAIN (probe);
861 if (probe == NULL_TREE)
864 return !exact || base == NULL_TREE || length == list_length (t1);
867 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
868 [] can match [size]. */
871 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
880 /* The type of the array elements must be the same. */
881 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
884 d1 = TYPE_DOMAIN (t1);
885 d2 = TYPE_DOMAIN (t2);
890 /* If one of the arrays is dimensionless, and the other has a
891 dimension, they are of different types. However, it is valid to
899 declarations for an array object can specify
900 array types that differ by the presence or absence of a major
901 array bound (_dcl.array_). */
903 return allow_redeclaration;
905 /* Check that the dimensions are the same. */
907 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
909 max1 = TYPE_MAX_VALUE (d1);
910 max2 = TYPE_MAX_VALUE (d2);
911 if (processing_template_decl && !abi_version_at_least (2)
912 && !value_dependent_expression_p (max1)
913 && !value_dependent_expression_p (max2))
915 /* With abi-1 we do not fold non-dependent array bounds, (and
916 consequently mangle them incorrectly). We must therefore
917 fold them here, to verify the domains have the same
923 if (!cp_tree_equal (max1, max2))
929 /* Subroutine in comptypes. */
932 structural_comptypes (tree t1, tree t2, int strict)
937 /* Suppress errors caused by previously reported errors. */
938 if (t1 == error_mark_node || t2 == error_mark_node)
941 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
943 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
944 current instantiation. */
945 if (TREE_CODE (t1) == TYPENAME_TYPE)
947 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
949 if (resolved != error_mark_node)
953 if (TREE_CODE (t2) == TYPENAME_TYPE)
955 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
957 if (resolved != error_mark_node)
961 if (TYPE_PTRMEMFUNC_P (t1))
962 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
963 if (TYPE_PTRMEMFUNC_P (t2))
964 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
966 /* Different classes of types can't be compatible. */
967 if (TREE_CODE (t1) != TREE_CODE (t2))
970 /* Qualifiers must match. For array types, we will check when we
971 recur on the array element types. */
972 if (TREE_CODE (t1) != ARRAY_TYPE
973 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
975 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
978 /* Allow for two different type nodes which have essentially the same
979 definition. Note that we already checked for equality of the type
980 qualifiers (just above). */
982 if (TREE_CODE (t1) != ARRAY_TYPE
983 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
986 /* Compare the types. Break out if they could be the same. */
987 switch (TREE_CODE (t1))
989 case TEMPLATE_TEMPLATE_PARM:
990 case BOUND_TEMPLATE_TEMPLATE_PARM:
991 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
992 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
993 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
994 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1025 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1030 case REFERENCE_TYPE:
1031 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1032 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1033 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1041 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1046 /* Target types must match incl. qualifiers. */
1047 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1051 case TEMPLATE_TYPE_PARM:
1052 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1053 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1054 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1055 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1060 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1061 TYPENAME_TYPE_FULLNAME (t2)))
1063 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1067 case UNBOUND_CLASS_TEMPLATE:
1068 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1070 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1075 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1080 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1081 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1085 case TYPE_PACK_EXPANSION:
1086 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1087 PACK_EXPANSION_PATTERN (t2));
1093 /* If we get here, we know that from a target independent POV the
1094 types are the same. Make sure the target attributes are also
1096 return targetm.comp_type_attributes (t1, t2);
1099 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1100 is a bitwise-or of the COMPARE_* flags. */
1103 comptypes (tree t1, tree t2, int strict)
1105 if (strict == COMPARE_STRICT)
1112 if (t1 == error_mark_node || t2 == error_mark_node)
1115 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1116 /* At least one of the types requires structural equality, so
1117 perform a deep check. */
1118 return structural_comptypes (t1, t2, strict);
1120 if (VERIFY_CANONICAL_TYPES)
1122 result = structural_comptypes (t1, t2, strict);
1124 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1126 /* The two types are structurally equivalent, but their
1127 canonical types were different. This is a failure of the
1128 canonical type propagation code.*/
1130 "canonical types differ for identical types %T and %T",
1135 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1137 /* Two types are structurally different, but the canonical
1138 types are the same. This means we were over-eager in
1139 assigning canonical types. */
1141 "same canonical type node for different types %T and %T",
1150 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1152 else if (strict == COMPARE_STRUCTURAL)
1153 return structural_comptypes (t1, t2, COMPARE_STRICT);
1155 return structural_comptypes (t1, t2, strict);
1158 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1161 at_least_as_qualified_p (tree type1, tree type2)
1163 int q1 = cp_type_quals (type1);
1164 int q2 = cp_type_quals (type2);
1166 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1167 return (q1 & q2) == q2;
1170 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1171 more cv-qualified that TYPE1, and 0 otherwise. */
1174 comp_cv_qualification (tree type1, tree type2)
1176 int q1 = cp_type_quals (type1);
1177 int q2 = cp_type_quals (type2);
1182 if ((q1 & q2) == q2)
1184 else if ((q1 & q2) == q1)
1190 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1191 subset of the cv-qualification signature of TYPE2, and the types
1192 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1195 comp_cv_qual_signature (tree type1, tree type2)
1197 if (comp_ptr_ttypes_real (type2, type1, -1))
1199 else if (comp_ptr_ttypes_real (type1, type2, -1))
1205 /* Subroutines of `comptypes'. */
1207 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1208 equivalent in the sense that functions with those parameter types
1209 can have equivalent types. The two lists must be equivalent,
1210 element by element. */
1213 compparms (tree parms1, tree parms2)
1217 /* An unspecified parmlist matches any specified parmlist
1218 whose argument types don't need default promotions. */
1220 for (t1 = parms1, t2 = parms2;
1222 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1224 /* If one parmlist is shorter than the other,
1225 they fail to match. */
1228 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1235 /* Process a sizeof or alignof expression where the operand is a
1239 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1244 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1245 if (type == error_mark_node)
1246 return error_mark_node;
1248 type = non_reference (type);
1249 if (TREE_CODE (type) == METHOD_TYPE)
1251 if (complain && (pedantic || warn_pointer_arith))
1252 pedwarn ("invalid application of %qs to a member function",
1253 operator_name_info[(int) op].name);
1254 value = size_one_node;
1257 dependent_p = dependent_type_p (type);
1259 complete_type (type);
1261 /* VLA types will have a non-constant size. In the body of an
1262 uninstantiated template, we don't need to try to compute the
1263 value, because the sizeof expression is not an integral
1264 constant expression in that case. And, if we do try to
1265 compute the value, we'll likely end up with SAVE_EXPRs, which
1266 the template substitution machinery does not expect to see. */
1267 || (processing_template_decl
1268 && COMPLETE_TYPE_P (type)
1269 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1271 value = build_min (op, size_type_node, type);
1272 TREE_READONLY (value) = 1;
1276 return c_sizeof_or_alignof_type (complete_type (type),
1281 /* Process a sizeof expression where the operand is an expression. */
1284 cxx_sizeof_expr (tree e)
1286 if (e == error_mark_node)
1287 return error_mark_node;
1289 if (processing_template_decl)
1291 e = build_min (SIZEOF_EXPR, size_type_node, e);
1292 TREE_SIDE_EFFECTS (e) = 0;
1293 TREE_READONLY (e) = 1;
1298 if (TREE_CODE (e) == COMPONENT_REF
1299 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1300 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1302 error ("invalid application of %<sizeof%> to a bit-field");
1305 else if (is_overloaded_fn (e))
1307 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1311 else if (type_unknown_p (e))
1313 cxx_incomplete_type_error (e, TREE_TYPE (e));
1319 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1322 /* Implement the __alignof keyword: Return the minimum required
1323 alignment of E, measured in bytes. For VAR_DECL's and
1324 FIELD_DECL's return DECL_ALIGN (which can be set from an
1325 "aligned" __attribute__ specification). */
1328 cxx_alignof_expr (tree e)
1332 if (e == error_mark_node)
1333 return error_mark_node;
1335 if (processing_template_decl)
1337 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1338 TREE_SIDE_EFFECTS (e) = 0;
1339 TREE_READONLY (e) = 1;
1344 if (TREE_CODE (e) == VAR_DECL)
1345 t = size_int (DECL_ALIGN_UNIT (e));
1346 else if (TREE_CODE (e) == COMPONENT_REF
1347 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1348 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1350 error ("invalid application of %<__alignof%> to a bit-field");
1353 else if (TREE_CODE (e) == COMPONENT_REF
1354 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1355 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1356 else if (is_overloaded_fn (e))
1358 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1362 else if (type_unknown_p (e))
1364 cxx_incomplete_type_error (e, TREE_TYPE (e));
1368 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1370 return fold_convert (size_type_node, t);
1373 /* Process a sizeof or alignof expression E with code OP where the operand
1374 is an expression. */
1377 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1379 if (op == SIZEOF_EXPR)
1380 return cxx_sizeof_expr (e);
1382 return cxx_alignof_expr (e);
1385 /* EXPR is being used in a context that is not a function call.
1390 The expression can be used only as the left-hand operand of a
1391 member function call.
1393 [expr.mptr.operator]
1395 If the result of .* or ->* is a function, then that result can be
1396 used only as the operand for the function call operator ().
1398 by issuing an error message if appropriate. Returns true iff EXPR
1399 violates these rules. */
1402 invalid_nonstatic_memfn_p (tree expr)
1404 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1406 error ("invalid use of non-static member function");
1412 /* If EXP is a reference to a bitfield, and the type of EXP does not
1413 match the declared type of the bitfield, return the declared type
1414 of the bitfield. Otherwise, return NULL_TREE. */
1417 is_bitfield_expr_with_lowered_type (tree exp)
1419 switch (TREE_CODE (exp))
1422 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1424 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1427 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1431 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1437 field = TREE_OPERAND (exp, 1);
1438 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1440 if (same_type_ignoring_top_level_qualifiers_p
1441 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1443 return DECL_BIT_FIELD_TYPE (field);
1451 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1452 bitfield with a lowered type, the type of EXP is returned, rather
1456 unlowered_expr_type (tree exp)
1460 type = is_bitfield_expr_with_lowered_type (exp);
1462 type = TREE_TYPE (exp);
1467 /* Perform the conversions in [expr] that apply when an lvalue appears
1468 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1469 function-to-pointer conversions. In addition, manifest constants
1470 are replaced by their values, and bitfield references are converted
1471 to their declared types.
1473 Although the returned value is being used as an rvalue, this
1474 function does not wrap the returned expression in a
1475 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1476 that the return value is no longer an lvalue. */
1479 decay_conversion (tree exp)
1482 enum tree_code code;
1484 type = TREE_TYPE (exp);
1485 if (type == error_mark_node)
1486 return error_mark_node;
1488 if (type_unknown_p (exp))
1490 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1491 return error_mark_node;
1494 exp = decl_constant_value (exp);
1495 if (error_operand_p (exp))
1496 return error_mark_node;
1498 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1499 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1500 code = TREE_CODE (type);
1501 if (code == VOID_TYPE)
1503 error ("void value not ignored as it ought to be");
1504 return error_mark_node;
1506 if (invalid_nonstatic_memfn_p (exp))
1507 return error_mark_node;
1508 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1509 return build_unary_op (ADDR_EXPR, exp, 0);
1510 if (code == ARRAY_TYPE)
1515 if (TREE_CODE (exp) == INDIRECT_REF)
1516 return build_nop (build_pointer_type (TREE_TYPE (type)),
1517 TREE_OPERAND (exp, 0));
1519 if (TREE_CODE (exp) == COMPOUND_EXPR)
1521 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1522 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1523 TREE_OPERAND (exp, 0), op1);
1527 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1529 error ("invalid use of non-lvalue array");
1530 return error_mark_node;
1533 ptrtype = build_pointer_type (TREE_TYPE (type));
1535 if (TREE_CODE (exp) == VAR_DECL)
1537 if (!cxx_mark_addressable (exp))
1538 return error_mark_node;
1539 adr = build_nop (ptrtype, build_address (exp));
1542 /* This way is better for a COMPONENT_REF since it can
1543 simplify the offset for a component. */
1544 adr = build_unary_op (ADDR_EXPR, exp, 1);
1545 return cp_convert (ptrtype, adr);
1548 /* If a bitfield is used in a context where integral promotion
1549 applies, then the caller is expected to have used
1550 default_conversion. That function promotes bitfields correctly
1551 before calling this function. At this point, if we have a
1552 bitfield referenced, we may assume that is not subject to
1553 promotion, and that, therefore, the type of the resulting rvalue
1554 is the declared type of the bitfield. */
1555 exp = convert_bitfield_to_declared_type (exp);
1557 /* We do not call rvalue() here because we do not want to wrap EXP
1558 in a NON_LVALUE_EXPR. */
1562 Non-class rvalues always have cv-unqualified types. */
1563 type = TREE_TYPE (exp);
1564 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1565 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1570 /* Perform prepatory conversions, as part of the "usual arithmetic
1571 conversions". In particular, as per [expr]:
1573 Whenever an lvalue expression appears as an operand of an
1574 operator that expects the rvalue for that operand, the
1575 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1576 standard conversions are applied to convert the expression to an
1579 In addition, we perform integral promotions here, as those are
1580 applied to both operands to a binary operator before determining
1581 what additional conversions should apply. */
1584 default_conversion (tree exp)
1586 /* Perform the integral promotions first so that bitfield
1587 expressions (which may promote to "int", even if the bitfield is
1588 declared "unsigned") are promoted correctly. */
1589 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1590 exp = perform_integral_promotions (exp);
1591 /* Perform the other conversions. */
1592 exp = decay_conversion (exp);
1597 /* EXPR is an expression with an integral or enumeration type.
1598 Perform the integral promotions in [conv.prom], and return the
1602 perform_integral_promotions (tree expr)
1609 If the bitfield has an enumerated type, it is treated as any
1610 other value of that type for promotion purposes. */
1611 type = is_bitfield_expr_with_lowered_type (expr);
1612 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1613 type = TREE_TYPE (expr);
1614 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1615 promoted_type = type_promotes_to (type);
1616 if (type != promoted_type)
1617 expr = cp_convert (promoted_type, expr);
1621 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1625 inline_conversion (tree exp)
1627 if (TREE_CODE (exp) == FUNCTION_DECL)
1628 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1633 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1634 decay_conversion to one. */
1637 string_conv_p (tree totype, tree exp, int warn)
1641 if (TREE_CODE (totype) != POINTER_TYPE)
1644 t = TREE_TYPE (totype);
1645 if (!same_type_p (t, char_type_node)
1646 && !same_type_p (t, wchar_type_node))
1649 if (TREE_CODE (exp) == STRING_CST)
1651 /* Make sure that we don't try to convert between char and wchar_t. */
1652 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1657 /* Is this a string constant which has decayed to 'const char *'? */
1658 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1659 if (!same_type_p (TREE_TYPE (exp), t))
1662 if (TREE_CODE (exp) != ADDR_EXPR
1663 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1667 /* This warning is not very useful, as it complains about printf. */
1669 warning (OPT_Wwrite_strings,
1670 "deprecated conversion from string constant to %qT",
1676 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1677 can, for example, use as an lvalue. This code used to be in
1678 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1679 expressions, where we're dealing with aggregates. But now it's again only
1680 called from unary_complex_lvalue. The case (in particular) that led to
1681 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1685 rationalize_conditional_expr (enum tree_code code, tree t)
1687 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1688 the first operand is always the one to be used if both operands
1689 are equal, so we know what conditional expression this used to be. */
1690 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1692 tree op0 = TREE_OPERAND (t, 0);
1693 tree op1 = TREE_OPERAND (t, 1);
1695 /* The following code is incorrect if either operand side-effects. */
1696 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1697 && !TREE_SIDE_EFFECTS (op1));
1699 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1700 ? LE_EXPR : GE_EXPR),
1701 op0, TREE_CODE (op0),
1702 op1, TREE_CODE (op1),
1703 /*overloaded_p=*/NULL),
1704 build_unary_op (code, op0, 0),
1705 build_unary_op (code, op1, 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 front end; only _DECLs and _REFs are lvalues in the back end. */
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 warn_array_subscript_with_type_char (idx);
2523 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2528 /* Resolve a pointer to member function. INSTANCE is the object
2529 instance to use, if the member points to a virtual member.
2531 This used to avoid checking for virtual functions if basetype
2532 has no virtual functions, according to an earlier ANSI draft.
2533 With the final ISO C++ rules, such an optimization is
2534 incorrect: A pointer to a derived member can be static_cast
2535 to pointer-to-base-member, as long as the dynamic object
2536 later has the right member. */
2539 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2541 if (TREE_CODE (function) == OFFSET_REF)
2542 function = TREE_OPERAND (function, 1);
2544 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2546 tree idx, delta, e1, e2, e3, vtbl, basetype;
2547 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2549 tree instance_ptr = *instance_ptrptr;
2550 tree instance_save_expr = 0;
2551 if (instance_ptr == error_mark_node)
2553 if (TREE_CODE (function) == PTRMEM_CST)
2555 /* Extracting the function address from a pmf is only
2556 allowed with -Wno-pmf-conversions. It only works for
2558 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2559 e1 = convert (fntype, e1);
2564 error ("object missing in use of %qE", function);
2565 return error_mark_node;
2569 if (TREE_SIDE_EFFECTS (instance_ptr))
2570 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2572 if (TREE_SIDE_EFFECTS (function))
2573 function = save_expr (function);
2575 /* Start by extracting all the information from the PMF itself. */
2576 e3 = pfn_from_ptrmemfunc (function);
2577 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2578 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2579 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2581 case ptrmemfunc_vbit_in_pfn:
2582 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2583 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2586 case ptrmemfunc_vbit_in_delta:
2587 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2588 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2595 /* Convert down to the right base before using the instance. A
2596 special case is that in a pointer to member of class C, C may
2597 be incomplete. In that case, the function will of course be
2598 a member of C, and no conversion is required. In fact,
2599 lookup_base will fail in that case, because incomplete
2600 classes do not have BINFOs. */
2601 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2602 if (!same_type_ignoring_top_level_qualifiers_p
2603 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2605 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2606 basetype, ba_check, NULL);
2607 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2609 if (instance_ptr == error_mark_node)
2610 return error_mark_node;
2612 /* ...and then the delta in the PMF. */
2613 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2614 instance_ptr, delta);
2616 /* Hand back the adjusted 'this' argument to our caller. */
2617 *instance_ptrptr = instance_ptr;
2619 /* Next extract the vtable pointer from the object. */
2620 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2622 vtbl = build_indirect_ref (vtbl, NULL);
2624 /* Finally, extract the function pointer from the vtable. */
2625 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2626 e2 = build_indirect_ref (e2, NULL);
2627 TREE_CONSTANT (e2) = 1;
2628 TREE_INVARIANT (e2) = 1;
2630 /* When using function descriptors, the address of the
2631 vtable entry is treated as a function pointer. */
2632 if (TARGET_VTABLE_USES_DESCRIPTORS)
2633 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2634 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2636 TREE_TYPE (e2) = TREE_TYPE (e3);
2637 e1 = build_conditional_expr (e1, e2, e3);
2639 /* Make sure this doesn't get evaluated first inside one of the
2640 branches of the COND_EXPR. */
2641 if (instance_save_expr)
2642 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2643 instance_save_expr, e1);
2651 build_function_call (tree function, tree params)
2653 tree fntype, fndecl;
2654 tree name = NULL_TREE;
2656 tree original = function;
2657 int nargs, parm_types_len;
2661 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2662 expressions, like those used for ObjC messenger dispatches. */
2663 function = objc_rewrite_function_call (function, params);
2665 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2666 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2667 if (TREE_CODE (function) == NOP_EXPR
2668 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2669 function = TREE_OPERAND (function, 0);
2671 if (TREE_CODE (function) == FUNCTION_DECL)
2673 name = DECL_NAME (function);
2675 mark_used (function);
2678 /* Convert anything with function type to a pointer-to-function. */
2679 if (pedantic && DECL_MAIN_P (function))
2680 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2682 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2683 (because calling an inline function does not mean the function
2684 needs to be separately compiled). */
2686 if (DECL_INLINE (function))
2687 function = inline_conversion (function);
2689 function = build_addr_func (function);
2695 function = build_addr_func (function);
2698 if (function == error_mark_node)
2699 return error_mark_node;
2701 fntype = TREE_TYPE (function);
2703 if (TYPE_PTRMEMFUNC_P (fntype))
2705 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2706 "function in %<%E (...)%>",
2708 return error_mark_node;
2711 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2712 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2714 if (!((TREE_CODE (fntype) == POINTER_TYPE
2715 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2717 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2719 error ("%qE cannot be used as a function", original);
2720 return error_mark_node;
2723 /* fntype now gets the type of function pointed to. */
2724 fntype = TREE_TYPE (fntype);
2725 parm_types = TYPE_ARG_TYPES (fntype);
2727 /* Allocate storage for converted arguments. */
2728 parm_types_len = list_length (parm_types);
2729 nargs = list_length (params);
2730 if (parm_types_len > nargs)
2731 nargs = parm_types_len;
2732 argarray = (tree *) alloca (nargs * sizeof (tree));
2734 /* Convert the parameters to the types declared in the
2735 function prototype, or apply default promotions. */
2736 nargs = convert_arguments (nargs, argarray, parm_types,
2737 params, fndecl, LOOKUP_NORMAL);
2739 return error_mark_node;
2741 /* Check for errors in format strings and inappropriately
2744 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2747 return build_cxx_call (function, nargs, argarray);
2750 /* Convert the actual parameter expressions in the list VALUES
2751 to the types in the list TYPELIST.
2752 If parmdecls is exhausted, or when an element has NULL as its type,
2753 perform the default conversions.
2755 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2757 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2759 This is also where warnings about wrong number of args are generated.
2761 Returns the actual number of arguments processed (which might be less
2762 than NARGS), or -1 on error.
2764 VALUES is a chain of TREE_LIST nodes with the elements of the list
2765 in the TREE_VALUE slots of those nodes.
2767 In C++, unspecified trailing parameters can be filled in with their
2768 default arguments, if such were specified. Do so here. */
2771 convert_arguments (int nargs, tree *argarray,
2772 tree typelist, tree values, tree fndecl, int flags)
2774 tree typetail, valtail;
2775 const char *called_thing = 0;
2778 /* Argument passing is always copy-initialization. */
2779 flags |= LOOKUP_ONLYCONVERTING;
2783 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2785 if (DECL_NAME (fndecl) == NULL_TREE
2786 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2787 called_thing = "constructor";
2789 called_thing = "member function";
2792 called_thing = "function";
2795 for (valtail = values, typetail = typelist;
2797 valtail = TREE_CHAIN (valtail), i++)
2799 tree type = typetail ? TREE_VALUE (typetail) : 0;
2800 tree val = TREE_VALUE (valtail);
2802 if (val == error_mark_node || type == error_mark_node)
2805 if (type == void_type_node)
2809 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2810 error ("at this point in file");
2813 error ("too many arguments to function");
2817 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2818 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2819 if (TREE_CODE (val) == NOP_EXPR
2820 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2821 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2822 val = TREE_OPERAND (val, 0);
2824 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2826 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2827 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2828 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2829 val = decay_conversion (val);
2832 if (val == error_mark_node)
2837 /* Formal parm type is specified by a function prototype. */
2840 if (!COMPLETE_TYPE_P (complete_type (type)))
2843 error ("parameter %P of %qD has incomplete type %qT",
2846 error ("parameter %P has incomplete type %qT", i, type);
2847 parmval = error_mark_node;
2851 parmval = convert_for_initialization
2852 (NULL_TREE, type, val, flags,
2853 "argument passing", fndecl, i);
2854 parmval = convert_for_arg_passing (type, parmval);
2857 if (parmval == error_mark_node)
2860 argarray[i] = parmval;
2864 if (fndecl && DECL_BUILT_IN (fndecl)
2865 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2866 /* Don't do ellipsis conversion for __built_in_constant_p
2867 as this will result in spurious warnings for non-POD
2869 val = require_complete_type (val);
2871 val = convert_arg_to_ellipsis (val);
2877 typetail = TREE_CHAIN (typetail);
2880 if (typetail != 0 && typetail != void_list_node)
2882 /* See if there are default arguments that can be used. */
2883 if (TREE_PURPOSE (typetail)
2884 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2886 for (; typetail != void_list_node; ++i)
2889 = convert_default_arg (TREE_VALUE (typetail),
2890 TREE_PURPOSE (typetail),
2893 if (parmval == error_mark_node)
2896 argarray[i] = parmval;
2897 typetail = TREE_CHAIN (typetail);
2898 /* ends with `...'. */
2899 if (typetail == NULL_TREE)
2907 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2908 error ("at this point in file");
2911 error ("too few arguments to function");
2916 gcc_assert (i <= nargs);
2920 /* Build a binary-operation expression, after performing default
2921 conversions on the operands. CODE is the kind of expression to
2922 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2923 are the tree codes which correspond to ARG1 and ARG2 when issuing
2924 warnings about possibly misplaced parentheses. They may differ
2925 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2926 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2927 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2928 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2929 ARG2_CODE as ERROR_MARK. */
2932 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2933 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2942 if (processing_template_decl)
2944 if (type_dependent_expression_p (arg1)
2945 || type_dependent_expression_p (arg2))
2946 return build_min_nt (code, arg1, arg2);
2947 arg1 = build_non_dependent_expr (arg1);
2948 arg2 = build_non_dependent_expr (arg2);
2951 if (code == DOTSTAR_EXPR)
2952 expr = build_m_component_ref (arg1, arg2);
2954 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2957 /* Check for cases such as x+y<<z which users are likely to
2958 misinterpret. But don't warn about obj << x + y, since that is a
2959 common idiom for I/O. */
2960 if (warn_parentheses
2961 && !processing_template_decl
2962 && !error_operand_p (arg1)
2963 && !error_operand_p (arg2)
2964 && (code != LSHIFT_EXPR
2965 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2966 warn_about_parentheses (code, arg1_code, arg2_code);
2968 if (processing_template_decl && expr != error_mark_node)
2969 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2974 /* Build a binary-operation expression without default conversions.
2975 CODE is the kind of expression to build.
2976 This function differs from `build' in several ways:
2977 the data type of the result is computed and recorded in it,
2978 warnings are generated if arg data types are invalid,
2979 special handling for addition and subtraction of pointers is known,
2980 and some optimization is done (operations on narrow ints
2981 are done in the narrower type when that gives the same result).
2982 Constant folding is also done before the result is returned.
2984 Note that the operands will never have enumeral types
2985 because either they have just had the default conversions performed
2986 or they have both just been converted to some other type in which
2987 the arithmetic is to be done.
2989 C++: must do special pointer arithmetic when implementing
2990 multiple inheritance, and deal with pointer to member functions. */
2993 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2994 int convert_p ATTRIBUTE_UNUSED)
2997 enum tree_code code0, code1;
2999 const char *invalid_op_diag;
3001 /* Expression code to give to the expression when it is built.
3002 Normally this is CODE, which is what the caller asked for,
3003 but in some special cases we change it. */
3004 enum tree_code resultcode = code;
3006 /* Data type in which the computation is to be performed.
3007 In the simplest cases this is the common type of the arguments. */
3008 tree result_type = NULL;
3010 /* Nonzero means operands have already been type-converted
3011 in whatever way is necessary.
3012 Zero means they need to be converted to RESULT_TYPE. */
3015 /* Nonzero means create the expression with this type, rather than
3017 tree build_type = 0;
3019 /* Nonzero means after finally constructing the expression
3020 convert it to this type. */
3021 tree final_type = 0;
3025 /* Nonzero if this is an operation like MIN or MAX which can
3026 safely be computed in short if both args are promoted shorts.
3027 Also implies COMMON.
3028 -1 indicates a bitwise operation; this makes a difference
3029 in the exact conditions for when it is safe to do the operation
3030 in a narrower mode. */
3033 /* Nonzero if this is a comparison operation;
3034 if both args are promoted shorts, compare the original shorts.
3035 Also implies COMMON. */
3036 int short_compare = 0;
3038 /* Nonzero if this is a right-shift operation, which can be computed on the
3039 original short and then promoted if the operand is a promoted short. */
3040 int short_shift = 0;
3042 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3045 /* True if both operands have arithmetic type. */
3046 bool arithmetic_types_p;
3048 /* Apply default conversions. */
3052 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3053 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3054 || code == TRUTH_XOR_EXPR)
3056 if (!really_overloaded_fn (op0))
3057 op0 = decay_conversion (op0);
3058 if (!really_overloaded_fn (op1))
3059 op1 = decay_conversion (op1);
3063 if (!really_overloaded_fn (op0))
3064 op0 = default_conversion (op0);
3065 if (!really_overloaded_fn (op1))
3066 op1 = default_conversion (op1);
3069 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3070 STRIP_TYPE_NOPS (op0);
3071 STRIP_TYPE_NOPS (op1);
3073 /* DTRT if one side is an overloaded function, but complain about it. */
3074 if (type_unknown_p (op0))
3076 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3077 if (t != error_mark_node)
3079 pedwarn ("assuming cast to type %qT from overloaded function",
3084 if (type_unknown_p (op1))
3086 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3087 if (t != error_mark_node)
3089 pedwarn ("assuming cast to type %qT from overloaded function",
3095 type0 = TREE_TYPE (op0);
3096 type1 = TREE_TYPE (op1);
3098 /* The expression codes of the data types of the arguments tell us
3099 whether the arguments are integers, floating, pointers, etc. */
3100 code0 = TREE_CODE (type0);
3101 code1 = TREE_CODE (type1);
3103 /* If an error was already reported for one of the arguments,
3104 avoid reporting another error. */
3106 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3107 return error_mark_node;
3109 if ((invalid_op_diag
3110 = targetm.invalid_binary_op (code, type0, type1)))
3112 error (invalid_op_diag);
3113 return error_mark_node;
3119 /* Subtraction of two similar pointers.
3120 We must subtract them as integers, then divide by object size. */
3121 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3122 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3124 return pointer_diff (op0, op1, common_type (type0, type1));
3125 /* In all other cases except pointer - int, the usual arithmetic
3127 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3132 /* The pointer - int case is just like pointer + int; fall
3135 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3136 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3140 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3141 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3142 if (processing_template_decl)
3144 result_type = TREE_TYPE (ptr_operand);
3147 return cp_pointer_int_sum (code,
3158 case TRUNC_DIV_EXPR:
3160 case FLOOR_DIV_EXPR:
3161 case ROUND_DIV_EXPR:
3162 case EXACT_DIV_EXPR:
3163 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3164 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3165 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3166 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3168 enum tree_code tcode0 = code0, tcode1 = code1;
3170 warn_for_div_by_zero (op1);
3172 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3173 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3174 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3175 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3177 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3178 resultcode = RDIV_EXPR;
3180 /* When dividing two signed integers, we have to promote to int.
3181 unless we divide by a constant != -1. Note that default
3182 conversion will have been performed on the operands at this
3183 point, so we have to dig out the original type to find out if
3185 shorten = ((TREE_CODE (op0) == NOP_EXPR
3186 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3187 || (TREE_CODE (op1) == INTEGER_CST
3188 && ! integer_all_onesp (op1)));
3197 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3198 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3202 case TRUNC_MOD_EXPR:
3203 case FLOOR_MOD_EXPR:
3204 warn_for_div_by_zero (op1);
3206 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3208 /* Although it would be tempting to shorten always here, that loses
3209 on some targets, since the modulo instruction is undefined if the
3210 quotient can't be represented in the computation mode. We shorten
3211 only if unsigned or if dividing by something we know != -1. */
3212 shorten = ((TREE_CODE (op0) == NOP_EXPR
3213 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3214 || (TREE_CODE (op1) == INTEGER_CST
3215 && ! integer_all_onesp (op1)));
3220 case TRUTH_ANDIF_EXPR:
3221 case TRUTH_ORIF_EXPR:
3222 case TRUTH_AND_EXPR:
3224 result_type = boolean_type_node;
3227 /* Shift operations: result has same type as first operand;
3228 always convert second operand to int.
3229 Also set SHORT_SHIFT if shifting rightward. */
3232 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3234 result_type = type0;
3235 if (TREE_CODE (op1) == INTEGER_CST)
3237 if (tree_int_cst_lt (op1, integer_zero_node))
3238 warning (0, "right shift count is negative");
3241 if (! integer_zerop (op1))
3243 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3244 warning (0, "right shift count >= width of type");
3247 /* Convert the shift-count to an integer, regardless of
3248 size of value being shifted. */
3249 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3250 op1 = cp_convert (integer_type_node, op1);
3251 /* Avoid converting op1 to result_type later. */
3257 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3259 result_type = type0;
3260 if (TREE_CODE (op1) == INTEGER_CST)
3262 if (tree_int_cst_lt (op1, integer_zero_node))
3263 warning (0, "left shift count is negative");
3264 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3265 warning (0, "left shift count >= width of type");
3267 /* Convert the shift-count to an integer, regardless of
3268 size of value being shifted. */
3269 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3270 op1 = cp_convert (integer_type_node, op1);
3271 /* Avoid converting op1 to result_type later. */
3278 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3280 result_type = type0;
3281 if (TREE_CODE (op1) == INTEGER_CST)
3283 if (tree_int_cst_lt (op1, integer_zero_node))
3284 warning (0, (code == LROTATE_EXPR)
3285 ? G_("left rotate count is negative")
3286 : G_("right rotate count is negative"));
3287 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3288 warning (0, (code == LROTATE_EXPR)
3289 ? G_("left rotate count >= width of type")
3290 : G_("right rotate count >= width of type"));
3292 /* Convert the shift-count to an integer, regardless of
3293 size of value being shifted. */
3294 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3295 op1 = cp_convert (integer_type_node, op1);
3301 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3302 warning (OPT_Wfloat_equal,
3303 "comparing floating point with == or != is unsafe");
3304 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3305 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3306 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3308 build_type = boolean_type_node;
3309 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3310 || code0 == COMPLEX_TYPE)
3311 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3312 || code1 == COMPLEX_TYPE))
3314 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3315 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3316 result_type = composite_pointer_type (type0, type1, op0, op1,
3318 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3319 && null_ptr_cst_p (op1))
3321 if (TREE_CODE (op0) == ADDR_EXPR
3322 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3323 warning (OPT_Waddress, "the address of %qD will never be NULL",
3324 TREE_OPERAND (op0, 0));
3325 result_type = type0;
3327 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3328 && null_ptr_cst_p (op0))
3330 if (TREE_CODE (op1) == ADDR_EXPR
3331 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3332 warning (OPT_Waddress, "the address of %qD will never be NULL",
3333 TREE_OPERAND (op1, 0));
3334 result_type = type1;
3336 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3338 result_type = type0;
3339 error ("ISO C++ forbids comparison between pointer and integer");
3341 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3343 result_type = type1;
3344 error ("ISO C++ forbids comparison between pointer and integer");
3346 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3348 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3349 == ptrmemfunc_vbit_in_delta)
3351 tree pfn0 = pfn_from_ptrmemfunc (op0);
3352 tree delta0 = build_ptrmemfunc_access_expr (op0,
3354 tree e1 = cp_build_binary_op (EQ_EXPR,
3356 fold_convert (TREE_TYPE (pfn0),
3357 integer_zero_node));
3358 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3361 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3362 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3363 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3367 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3368 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3370 result_type = TREE_TYPE (op0);
3372 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3373 return cp_build_binary_op (code, op1, op0);
3374 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3375 && same_type_p (type0, type1))
3377 /* E will be the final comparison. */
3379 /* E1 and E2 are for scratch. */
3387 if (TREE_SIDE_EFFECTS (op0))
3388 op0 = save_expr (op0);
3389 if (TREE_SIDE_EFFECTS (op1))
3390 op1 = save_expr (op1);
3392 pfn0 = pfn_from_ptrmemfunc (op0);
3393 pfn1 = pfn_from_ptrmemfunc (op1);
3394 delta0 = build_ptrmemfunc_access_expr (op0,
3396 delta1 = build_ptrmemfunc_access_expr (op1,
3398 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3399 == ptrmemfunc_vbit_in_delta)
3404 && ((op0.delta == op1.delta)
3405 || (!op0.pfn && op0.delta & 1 == 0
3406 && op1.delta & 1 == 0))
3408 The reason for the `!op0.pfn' bit is that a NULL
3409 pointer-to-member is any member with a zero PFN and
3410 LSB of the DELTA field is 0. */
3412 e1 = cp_build_binary_op (BIT_AND_EXPR,
3415 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3416 e2 = cp_build_binary_op (BIT_AND_EXPR,
3419 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3420 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3421 e2 = cp_build_binary_op (EQ_EXPR,
3423 fold_convert (TREE_TYPE (pfn0),
3424 integer_zero_node));
3425 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3426 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3427 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3434 && (!op0.pfn || op0.delta == op1.delta))
3436 The reason for the `!op0.pfn' bit is that a NULL
3437 pointer-to-member is any member with a zero PFN; the
3438 DELTA field is unspecified. */
3440 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3441 e2 = cp_build_binary_op (EQ_EXPR,
3443 fold_convert (TREE_TYPE (pfn0),
3444 integer_zero_node));
3445 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3447 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3448 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3449 if (code == EQ_EXPR)
3451 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3455 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3456 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3458 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3459 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3467 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3468 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3470 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3471 result_type = composite_pointer_type (type0, type1, op0, op1,
3479 if (TREE_CODE (orig_op0) == STRING_CST
3480 || TREE_CODE (orig_op1) == STRING_CST)
3481 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3483 build_type = boolean_type_node;
3484 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3485 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3487 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3488 result_type = composite_pointer_type (type0, type1, op0, op1,
3490 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3491 && integer_zerop (op1))
3492 result_type = type0;
3493 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3494 && integer_zerop (op0))
3495 result_type = type1;
3496 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3498 result_type = type0;
3499 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3501 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3503 result_type = type1;
3504 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3508 case UNORDERED_EXPR:
3515 build_type = integer_type_node;
3516 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3518 error ("unordered comparison on non-floating point argument");
3519 return error_mark_node;
3528 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3529 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3530 || code1 == COMPLEX_TYPE)))
3531 arithmetic_types_p = 1;
3534 arithmetic_types_p = 0;
3535 /* Vector arithmetic is only allowed when both sides are vectors. */
3536 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3538 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3539 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3542 binary_op_error (code);
3543 return error_mark_node;
3545 arithmetic_types_p = 1;
3548 /* Determine the RESULT_TYPE, if it is not already known. */
3550 && arithmetic_types_p
3551 && (shorten || common || short_compare))
3552 result_type = common_type (type0, type1);
3556 error ("invalid operands of types %qT and %qT to binary %qO",
3557 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3558 return error_mark_node;
3561 /* If we're in a template, the only thing we need to know is the
3563 if (processing_template_decl)
3564 return build2 (resultcode,
3565 build_type ? build_type : result_type,
3568 if (arithmetic_types_p)
3570 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3572 /* For certain operations (which identify themselves by shorten != 0)
3573 if both args were extended from the same smaller type,
3574 do the arithmetic in that type and then extend.
3576 shorten !=0 and !=1 indicates a bitwise operation.
3577 For them, this optimization is safe only if
3578 both args are zero-extended or both are sign-extended.
3579 Otherwise, we might change the result.
3580 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3581 but calculated in (unsigned short) it would be (unsigned short)-1. */
3583 if (shorten && none_complex)
3585 int unsigned0, unsigned1;
3586 tree arg0 = get_narrower (op0, &unsigned0);
3587 tree arg1 = get_narrower (op1, &unsigned1);
3588 /* UNS is 1 if the operation to be done is an unsigned one. */
3589 int uns = TYPE_UNSIGNED (result_type);
3592 final_type = result_type;
3594 /* Handle the case that OP0 does not *contain* a conversion
3595 but it *requires* conversion to FINAL_TYPE. */
3597 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3598 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3599 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3600 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3602 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3604 /* For bitwise operations, signedness of nominal type
3605 does not matter. Consider only how operands were extended. */
3609 /* Note that in all three cases below we refrain from optimizing
3610 an unsigned operation on sign-extended args.
3611 That would not be valid. */
3613 /* Both args variable: if both extended in same way
3614 from same width, do it in that width.
3615 Do it unsigned if args were zero-extended. */
3616 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3617 < TYPE_PRECISION (result_type))
3618 && (TYPE_PRECISION (TREE_TYPE (arg1))
3619 == TYPE_PRECISION (TREE_TYPE (arg0)))
3620 && unsigned0 == unsigned1
3621 && (unsigned0 || !uns))
3622 result_type = c_common_signed_or_unsigned_type
3623 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3624 else if (TREE_CODE (arg0) == INTEGER_CST
3625 && (unsigned1 || !uns)
3626 && (TYPE_PRECISION (TREE_TYPE (arg1))
3627 < TYPE_PRECISION (result_type))
3628 && (type = c_common_signed_or_unsigned_type
3629 (unsigned1, TREE_TYPE (arg1)),
3630 int_fits_type_p (arg0, type)))
3632 else if (TREE_CODE (arg1) == INTEGER_CST
3633 && (unsigned0 || !uns)
3634 && (TYPE_PRECISION (TREE_TYPE (arg0))
3635 < TYPE_PRECISION (result_type))
3636 && (type = c_common_signed_or_unsigned_type
3637 (unsigned0, TREE_TYPE (arg0)),
3638 int_fits_type_p (arg1, type)))
3642 /* Shifts can be shortened if shifting right. */
3647 tree arg0 = get_narrower (op0, &unsigned_arg);
3649 final_type = result_type;
3651 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3652 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3654 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3655 /* We can shorten only if the shift count is less than the
3656 number of bits in the smaller type size. */
3657 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3658 /* If arg is sign-extended and then unsigned-shifted,
3659 we can simulate this with a signed shift in arg's type
3660 only if the extended result is at least twice as wide
3661 as the arg. Otherwise, the shift could use up all the
3662 ones made by sign-extension and bring in zeros.
3663 We can't optimize that case at all, but in most machines
3664 it never happens because available widths are 2**N. */
3665 && (!TYPE_UNSIGNED (final_type)
3667 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3668 <= TYPE_PRECISION (result_type))))
3670 /* Do an unsigned shift if the operand was zero-extended. */
3672 = c_common_signed_or_unsigned_type (unsigned_arg,
3674 /* Convert value-to-be-shifted to that type. */
3675 if (TREE_TYPE (op0) != result_type)
3676 op0 = cp_convert (result_type, op0);
3681 /* Comparison operations are shortened too but differently.
3682 They identify themselves by setting short_compare = 1. */
3686 /* Don't write &op0, etc., because that would prevent op0
3687 from being kept in a register.
3688 Instead, make copies of the our local variables and
3689 pass the copies by reference, then copy them back afterward. */
3690 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3691 enum tree_code xresultcode = resultcode;
3693 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3695 return cp_convert (boolean_type_node, val);
3696 op0 = xop0, op1 = xop1;
3698 resultcode = xresultcode;
3701 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3702 && warn_sign_compare
3703 /* Do not warn until the template is instantiated; we cannot
3704 bound the ranges of the arguments until that point. */
3705 && !processing_template_decl)
3707 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3708 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3710 int unsignedp0, unsignedp1;
3711 tree primop0 = get_narrower (op0, &unsignedp0);
3712 tree primop1 = get_narrower (op1, &unsignedp1);
3714 /* Check for comparison of different enum types. */
3715 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3716 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3717 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3718 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3720 warning (0, "comparison between types %q#T and %q#T",
3721 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3724 /* Give warnings for comparisons between signed and unsigned
3725 quantities that may fail. */
3726 /* Do the checking based on the original operand trees, so that
3727 casts will be considered, but default promotions won't be. */
3729 /* Do not warn if the comparison is being done in a signed type,
3730 since the signed type will only be chosen if it can represent
3731 all the values of the unsigned type. */
3732 if (!TYPE_UNSIGNED (result_type))
3734 /* Do not warn if both operands are unsigned. */
3735 else if (op0_signed == op1_signed)
3737 /* Do not warn if the signed quantity is an unsuffixed
3738 integer literal (or some static constant expression
3739 involving such literals or a conditional expression
3740 involving such literals) and it is non-negative. */
3741 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3742 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3744 /* Do not warn if the comparison is an equality operation,
3745 the unsigned quantity is an integral constant and it does
3746 not use the most significant bit of result_type. */
3747 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3748 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3749 && int_fits_type_p (orig_op1, c_common_signed_type
3751 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3752 && int_fits_type_p (orig_op0, c_common_signed_type
3756 warning (0, "comparison between signed and unsigned integer expressions");
3758 /* Warn if two unsigned values are being compared in a size
3759 larger than their original size, and one (and only one) is the
3760 result of a `~' operator. This comparison will always fail.
3762 Also warn if one operand is a constant, and the constant does not
3763 have all bits set that are set in the ~ operand when it is
3766 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3767 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3769 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3770 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3771 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3772 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3774 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3777 HOST_WIDE_INT constant, mask;
3781 if (host_integerp (primop0, 0))
3784 unsignedp = unsignedp1;
3785 constant = tree_low_cst (primop0, 0);
3790 unsignedp = unsignedp0;
3791 constant = tree_low_cst (primop1, 0);
3794 bits = TYPE_PRECISION (TREE_TYPE (primop));
3795 if (bits < TYPE_PRECISION (result_type)
3796 && bits < HOST_BITS_PER_LONG && unsignedp)
3798 mask = (~ (HOST_WIDE_INT) 0) << bits;
3799 if ((mask & constant) != mask)
3800 warning (0, "comparison of promoted ~unsigned with constant");
3803 else if (unsignedp0 && unsignedp1
3804 && (TYPE_PRECISION (TREE_TYPE (primop0))
3805 < TYPE_PRECISION (result_type))
3806 && (TYPE_PRECISION (TREE_TYPE (primop1))
3807 < TYPE_PRECISION (result_type)))
3808 warning (0, "comparison of promoted ~unsigned with unsigned");
3813 /* Issue warnings about peculiar, but valid, uses of NULL. */
3814 if ((orig_op0 == null_node || orig_op1 == null_node)
3815 /* It's reasonable to use pointer values as operands of &&
3816 and ||, so NULL is no exception. */
3817 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3818 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3819 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3820 && code != EQ_EXPR && code != NE_EXPR)
3821 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3822 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3823 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3824 /* Some sort of arithmetic operation involving NULL was
3825 performed. Note that pointer-difference and pointer-addition
3826 have already been handled above, and so we don't end up here in
3828 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3831 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3832 Then the expression will be built.
3833 It will be given type FINAL_TYPE if that is nonzero;
3834 otherwise, it will be given type RESULT_TYPE. */
3837 if (TREE_TYPE (op0) != result_type)
3838 op0 = cp_convert_and_check (result_type, op0);
3839 if (TREE_TYPE (op1) != result_type)
3840 op1 = cp_convert_and_check (result_type, op1);
3842 if (op0 == error_mark_node || op1 == error_mark_node)
3843 return error_mark_node;
3846 if (build_type == NULL_TREE)
3847 build_type = result_type;
3849 result = build2 (resultcode, build_type, op0, op1);
3850 result = fold_if_not_in_template (result);
3851 if (final_type != 0)
3852 result = cp_convert (final_type, result);
3854 if (TREE_OVERFLOW_P (result)
3855 && !TREE_OVERFLOW_P (op0)
3856 && !TREE_OVERFLOW_P (op1))
3857 overflow_warning (result);
3862 /* Return a tree for the sum or difference (RESULTCODE says which)
3863 of pointer PTROP and integer INTOP. */
3866 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3868 tree res_type = TREE_TYPE (ptrop);
3870 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3871 in certain circumstance (when it's valid to do so). So we need
3872 to make sure it's complete. We don't need to check here, if we
3873 can actually complete it at all, as those checks will be done in
3874 pointer_int_sum() anyway. */
3875 complete_type (TREE_TYPE (res_type));
3877 return pointer_int_sum (resultcode, ptrop,
3878 fold_if_not_in_template (intop));
3881 /* Return a tree for the difference of pointers OP0 and OP1.
3882 The resulting tree has type int. */
3885 pointer_diff (tree op0, tree op1, tree ptrtype)
3888 tree restype = ptrdiff_type_node;
3889 tree target_type = TREE_TYPE (ptrtype);
3891 if (!complete_type_or_else (target_type, NULL_TREE))
3892 return error_mark_node;
3894 if (pedantic || warn_pointer_arith)
3896 if (TREE_CODE (target_type) == VOID_TYPE)
3897 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3898 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3899 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3900 if (TREE_CODE (target_type) == METHOD_TYPE)
3901 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3904 /* First do the subtraction as integers;
3905 then drop through to build the divide operator. */
3907 op0 = cp_build_binary_op (MINUS_EXPR,
3908 cp_convert (restype, op0),
3909 cp_convert (restype, op1));
3911 /* This generates an error if op1 is a pointer to an incomplete type. */
3912 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3913 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3915 op1 = (TYPE_PTROB_P (ptrtype)
3916 ? size_in_bytes (target_type)
3917 : integer_one_node);
3919 /* Do the division. */
3921 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3922 return fold_if_not_in_template (result);
3925 /* Construct and perhaps optimize a tree representation
3926 for a unary operation. CODE, a tree_code, specifies the operation
3927 and XARG is the operand. */
3930 build_x_unary_op (enum tree_code code, tree xarg)
3932 tree orig_expr = xarg;
3936 if (processing_template_decl)
3938 if (type_dependent_expression_p (xarg))
3939 return build_min_nt (code, xarg, NULL_TREE);
3941 xarg = build_non_dependent_expr (xarg);
3946 /* [expr.unary.op] says:
3948 The address of an object of incomplete type can be taken.
3950 (And is just the ordinary address operator, not an overloaded
3951 "operator &".) However, if the type is a template
3952 specialization, we must complete the type at this point so that
3953 an overloaded "operator &" will be available if required. */
3954 if (code == ADDR_EXPR
3955 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3956 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3957 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3958 || (TREE_CODE (xarg) == OFFSET_REF)))
3959 /* Don't look for a function. */;
3961 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3962 /*overloaded_p=*/NULL);
3963 if (!exp && code == ADDR_EXPR)
3965 /* A pointer to member-function can be formed only by saying
3967 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3968 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3970 if (TREE_CODE (xarg) != OFFSET_REF
3971 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3973 error ("invalid use of %qE to form a pointer-to-member-function",
3975 if (TREE_CODE (xarg) != OFFSET_REF)
3976 inform (" a qualified-id is required");
3977 return error_mark_node;
3981 error ("parentheses around %qE cannot be used to form a"
3982 " pointer-to-member-function",
3984 PTRMEM_OK_P (xarg) = 1;
3988 if (TREE_CODE (xarg) == OFFSET_REF)
3990 ptrmem = PTRMEM_OK_P (xarg);
3992 if (!ptrmem && !flag_ms_extensions
3993 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3995 /* A single non-static member, make sure we don't allow a
3996 pointer-to-member. */
3997 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3998 TREE_OPERAND (xarg, 0),
3999 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4000 PTRMEM_OK_P (xarg) = ptrmem;
4003 else if (TREE_CODE (xarg) == TARGET_EXPR)
4004 warning (0, "taking address of temporary");
4005 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4008 if (processing_template_decl && exp != error_mark_node)
4009 exp = build_min_non_dep (code, exp, orig_expr,
4010 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4011 if (TREE_CODE (exp) == ADDR_EXPR)
4012 PTRMEM_OK_P (exp) = ptrmem;
4016 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4017 constants, where a null value is represented by an INTEGER_CST of
4021 cp_truthvalue_conversion (tree expr)
4023 tree type = TREE_TYPE (expr);
4024 if (TYPE_PTRMEM_P (type))
4025 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4027 return c_common_truthvalue_conversion (expr);
4030 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4033 condition_conversion (tree expr)
4036 if (processing_template_decl)
4038 t = perform_implicit_conversion (boolean_type_node, expr);
4039 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4043 /* Return an ADDR_EXPR giving the address of T. This function
4044 attempts no optimizations or simplifications; it is a low-level
4048 build_address (tree t)
4052 if (error_operand_p (t) || !cxx_mark_addressable (t))
4053 return error_mark_node;
4055 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4060 /* Return a NOP_EXPR converting EXPR to TYPE. */
4063 build_nop (tree type, tree expr)
4065 if (type == error_mark_node || error_operand_p (expr))
4067 return build1 (NOP_EXPR, type, expr);
4070 /* C++: Must handle pointers to members.
4072 Perhaps type instantiation should be extended to handle conversion
4073 from aggregates to types we don't yet know we want? (Or are those
4074 cases typically errors which should be reported?)
4076 NOCONVERT nonzero suppresses the default promotions
4077 (such as from short to int). */
4080 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4082 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4085 const char *errstring = NULL;
4087 const char *invalid_op_diag;
4089 if (arg == error_mark_node)
4090 return error_mark_node;
4092 if ((invalid_op_diag
4093 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4098 error (invalid_op_diag);
4099 return error_mark_node;
4104 case UNARY_PLUS_EXPR:
4107 int flags = WANT_ARITH | WANT_ENUM;
4108 /* Unary plus (but not unary minus) is allowed on pointers. */
4109 if (code == UNARY_PLUS_EXPR)
4110 flags |= WANT_POINTER;
4111 arg = build_expr_type_conversion (flags, arg, true);
4113 errstring = (code == NEGATE_EXPR
4114 ? "wrong type argument to unary minus"
4115 : "wrong type argument to unary plus");
4118 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4119 arg = perform_integral_promotions (arg);
4121 /* Make sure the result is not an lvalue: a unary plus or minus
4122 expression is always a rvalue. */
4129 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4133 arg = default_conversion (arg);
4135 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4138 errstring = "wrong type argument to bit-complement";
4139 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4140 arg = perform_integral_promotions (arg);
4144 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4145 errstring = "wrong type argument to abs";
4146 else if (!noconvert)
4147 arg = default_conversion (arg);
4151 /* Conjugating a real value is a no-op, but allow it anyway. */
4152 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4153 errstring = "wrong type argument to conjugation";
4154 else if (!noconvert)
4155 arg = default_conversion (arg);
4158 case TRUTH_NOT_EXPR:
4159 arg = perform_implicit_conversion (boolean_type_node, arg);
4160 val = invert_truthvalue (arg);
4161 if (arg != error_mark_node)
4163 errstring = "in argument to unary !";
4170 if (TREE_CODE (arg) == COMPLEX_CST)
4171 return TREE_REALPART (arg);
4172 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4174 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4175 return fold_if_not_in_template (arg);
4181 if (TREE_CODE (arg) == COMPLEX_CST)
4182 return TREE_IMAGPART (arg);
4183 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4185 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4186 return fold_if_not_in_template (arg);
4189 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4191 case PREINCREMENT_EXPR:
4192 case POSTINCREMENT_EXPR:
4193 case PREDECREMENT_EXPR:
4194 case POSTDECREMENT_EXPR:
4195 /* Handle complex lvalues (when permitted)
4196 by reduction to simpler cases. */
4198 val = unary_complex_lvalue (code, arg);
4202 /* Increment or decrement the real part of the value,
4203 and don't change the imaginary part. */
4204 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4208 arg = stabilize_reference (arg);
4209 real = build_unary_op (REALPART_EXPR, arg, 1);
4210 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4211 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4212 build_unary_op (code, real, 1), imag);
4215 /* Report invalid types. */
4217 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4220 if (code == PREINCREMENT_EXPR)
4221 errstring ="no pre-increment operator for type";
4222 else if (code == POSTINCREMENT_EXPR)
4223 errstring ="no post-increment operator for type";
4224 else if (code == PREDECREMENT_EXPR)
4225 errstring ="no pre-decrement operator for type";
4227 errstring ="no post-decrement operator for type";
4231 /* Report something read-only. */
4233 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4234 || TREE_READONLY (arg))
4235 readonly_error (arg, ((code == PREINCREMENT_EXPR
4236 || code == POSTINCREMENT_EXPR)
4237 ? "increment" : "decrement"));
4242 tree result_type = TREE_TYPE (arg);
4244 declared_type = unlowered_expr_type (arg);
4246 arg = get_unwidened (arg, 0);
4247 argtype = TREE_TYPE (arg);
4249 /* ARM $5.2.5 last annotation says this should be forbidden. */
4250 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4251 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4252 ? G_("ISO C++ forbids incrementing an enum")
4253 : G_("ISO C++ forbids decrementing an enum"));
4255 /* Compute the increment. */
4257 if (TREE_CODE (argtype) == POINTER_TYPE)
4259 tree type = complete_type (TREE_TYPE (argtype));
4261 if (!COMPLETE_OR_VOID_TYPE_P (type))
4262 error (((code == PREINCREMENT_EXPR
4263 || code == POSTINCREMENT_EXPR))
4264 ? G_("cannot increment a pointer to incomplete type %qT")
4265 : G_("cannot decrement a pointer to incomplete type %qT"),
4266 TREE_TYPE (argtype));
4267 else if ((pedantic || warn_pointer_arith)
4268 && !TYPE_PTROB_P (argtype))
4269 pedwarn ((code == PREINCREMENT_EXPR
4270 || code == POSTINCREMENT_EXPR)
4271 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4272 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4274 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4277 inc = integer_one_node;
4279 inc = cp_convert (argtype, inc);
4281 /* Complain about anything else that is not a true lvalue. */
4282 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4283 || code == POSTINCREMENT_EXPR)
4284 ? lv_increment : lv_decrement)))
4285 return error_mark_node;
4287 /* Forbid using -- on `bool'. */
4288 if (same_type_p (declared_type, boolean_type_node))
4290 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4292 error ("invalid use of %<--%> on bool variable %qD", arg);
4293 return error_mark_node;
4295 val = boolean_increment (code, arg);
4298 val = build2 (code, TREE_TYPE (arg), arg, inc);
4300 TREE_SIDE_EFFECTS (val) = 1;
4301 return cp_convert (result_type, val);
4305 /* Note that this operation never does default_conversion
4306 regardless of NOCONVERT. */
4308 argtype = lvalue_type (arg);
4310 if (TREE_CODE (arg) == OFFSET_REF)
4313 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4315 tree type = build_pointer_type (TREE_TYPE (argtype));
4316 arg = build1 (CONVERT_EXPR, type, arg);
4319 else if (pedantic && DECL_MAIN_P (arg))
4321 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4323 /* Let &* cancel out to simplify resulting code. */
4324 if (TREE_CODE (arg) == INDIRECT_REF)
4326 /* We don't need to have `current_class_ptr' wrapped in a
4327 NON_LVALUE_EXPR node. */
4328 if (arg == current_class_ref)
4329 return current_class_ptr;
4331 arg = TREE_OPERAND (arg, 0);
4332 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4334 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4335 arg = build1 (CONVERT_EXPR, type, arg);
4338 /* Don't let this be an lvalue. */
4343 /* Uninstantiated types are all functions. Taking the
4344 address of a function is a no-op, so just return the
4347 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4348 || !IDENTIFIER_OPNAME_P (arg));
4350 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4351 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4353 /* They're trying to take the address of a unique non-static
4354 member function. This is ill-formed (except in MS-land),
4355 but let's try to DTRT.
4356 Note: We only handle unique functions here because we don't
4357 want to complain if there's a static overload; non-unique
4358 cases will be handled by instantiate_type. But we need to
4359 handle this case here to allow casts on the resulting PMF.
4360 We could defer this in non-MS mode, but it's easier to give
4361 a useful error here. */
4363 /* Inside constant member functions, the `this' pointer
4364 contains an extra const qualifier. TYPE_MAIN_VARIANT
4365 is used here to remove this const from the diagnostics
4366 and the created OFFSET_REF. */
4367 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4368 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4371 if (! flag_ms_extensions)
4373 tree name = DECL_NAME (fn);
4374 if (current_class_type
4375 && TREE_OPERAND (arg, 0) == current_class_ref)
4376 /* An expression like &memfn. */
4377 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4378 " or parenthesized non-static member function to form"
4379 " a pointer to member function. Say %<&%T::%D%>",
4382 pedwarn ("ISO C++ forbids taking the address of a bound member"
4383 " function to form a pointer to member function."
4387 arg = build_offset_ref (base, fn, /*address_p=*/true);
4391 if (type_unknown_p (arg))
4392 return build1 (ADDR_EXPR, unknown_type_node, arg);
4394 /* Handle complex lvalues (when permitted)
4395 by reduction to simpler cases. */
4396 val = unary_complex_lvalue (code, arg);
4400 switch (TREE_CODE (arg))
4405 case FIX_TRUNC_EXPR:
4406 if (! lvalue_p (arg) && pedantic)
4407 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4411 arg = BASELINK_FUNCTIONS (arg);
4415 arg = OVL_CURRENT (arg);
4419 /* Turn a reference to a non-static data member into a
4420 pointer-to-member. */
4425 if (!PTRMEM_OK_P (arg))
4426 return build_unary_op (code, arg, 0);
4428 t = TREE_OPERAND (arg, 1);
4429 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4431 error ("cannot create pointer to reference member %qD", t);
4432 return error_mark_node;
4435 type = build_ptrmem_type (context_for_name_lookup (t),
4437 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4445 /* Anything not already handled and not a true memory reference
4447 if (TREE_CODE (argtype) != FUNCTION_TYPE
4448 && TREE_CODE (argtype) != METHOD_TYPE
4449 && TREE_CODE (arg) != OFFSET_REF
4450 && !lvalue_or_else (arg, lv_addressof))
4451 return error_mark_node;
4453 if (argtype != error_mark_node)
4454 argtype = build_pointer_type (argtype);
4456 /* In a template, we are processing a non-dependent expression
4457 so we can just form an ADDR_EXPR with the correct type. */
4458 if (processing_template_decl)
4460 val = build_address (arg);
4461 if (TREE_CODE (arg) == OFFSET_REF)
4462 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4466 if (TREE_CODE (arg) != COMPONENT_REF)
4468 val = build_address (arg);
4469 if (TREE_CODE (arg) == OFFSET_REF)
4470 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4472 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4474 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4476 /* We can only get here with a single static member
4478 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4479 && DECL_STATIC_FUNCTION_P (fn));
4481 val = build_address (fn);
4482 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4483 /* Do not lose object's side effects. */
4484 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4485 TREE_OPERAND (arg, 0), val);
4487 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4489 error ("attempt to take address of bit-field structure member %qD",
4490 TREE_OPERAND (arg, 1));
4491 return error_mark_node;
4495 tree object = TREE_OPERAND (arg, 0);
4496 tree field = TREE_OPERAND (arg, 1);
4497 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4498 (TREE_TYPE (object), decl_type_context (field)));
4499 val = build_address (arg);
4502 if (TREE_CODE (argtype) == POINTER_TYPE
4503 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4505 build_ptrmemfunc_type (argtype);
4506 val = build_ptrmemfunc (argtype, val, 0,
4507 /*c_cast_p=*/false);
4519 argtype = TREE_TYPE (arg);
4520 return fold_if_not_in_template (build1 (code, argtype, arg));
4523 error ("%s", errstring);
4524 return error_mark_node;
4527 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4528 for certain kinds of expressions which are not really lvalues
4529 but which we can accept as lvalues.
4531 If ARG is not a kind of expression we can handle, return
4535 unary_complex_lvalue (enum tree_code code, tree arg)
4537 /* Inside a template, making these kinds of adjustments is
4538 pointless; we are only concerned with the type of the
4540 if (processing_template_decl)
4543 /* Handle (a, b) used as an "lvalue". */
4544 if (TREE_CODE (arg) == COMPOUND_EXPR)
4546 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4547 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4548 TREE_OPERAND (arg, 0), real_result);
4551 /* Handle (a ? b : c) used as an "lvalue". */
4552 if (TREE_CODE (arg) == COND_EXPR
4553 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4554 return rationalize_conditional_expr (code, arg);
4556 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4557 if (TREE_CODE (arg) == MODIFY_EXPR
4558 || TREE_CODE (arg) == PREINCREMENT_EXPR
4559 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4561 tree lvalue = TREE_OPERAND (arg, 0);
4562 if (TREE_SIDE_EFFECTS (lvalue))
4564 lvalue = stabilize_reference (lvalue);
4565 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4566 lvalue, TREE_OPERAND (arg, 1));
4568 return unary_complex_lvalue
4569 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4572 if (code != ADDR_EXPR)
4575 /* Handle (a = b) used as an "lvalue" for `&'. */
4576 if (TREE_CODE (arg) == MODIFY_EXPR
4577 || TREE_CODE (arg) == INIT_EXPR)
4579 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4580 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4582 TREE_NO_WARNING (arg) = 1;
4586 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4587 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4588 || TREE_CODE (arg) == OFFSET_REF)
4591 /* We permit compiler to make function calls returning
4592 objects of aggregate type look like lvalues. */
4596 if (TREE_CODE (targ) == SAVE_EXPR)
4597 targ = TREE_OPERAND (targ, 0);
4599 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4601 if (TREE_CODE (arg) == SAVE_EXPR)
4604 targ = build_cplus_new (TREE_TYPE (arg), arg);
4605 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4608 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4609 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4610 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4613 /* Don't let anything else be handled specially. */
4617 /* Mark EXP saying that we need to be able to take the
4618 address of it; it should not be allocated in a register.
4619 Value is true if successful.
4621 C++: we do not allow `current_class_ptr' to be addressable. */
4624 cxx_mark_addressable (tree exp)
4629 switch (TREE_CODE (x))
4636 x = TREE_OPERAND (x, 0);
4640 if (x == current_class_ptr)
4642 error ("cannot take the address of %<this%>, which is an rvalue expression");
4643 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4649 /* Caller should not be trying to mark initialized
4650 constant fields addressable. */
4651 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4652 || DECL_IN_AGGR_P (x) == 0
4654 || DECL_EXTERNAL (x));
4659 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4660 && !DECL_ARTIFICIAL (x))
4662 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4665 ("address of explicit register variable %qD requested", x);
4668 else if (extra_warnings)
4670 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4672 TREE_ADDRESSABLE (x) = 1;
4676 TREE_ADDRESSABLE (x) = 1;
4680 TREE_ADDRESSABLE (x) = 1;
4684 TREE_ADDRESSABLE (x) = 1;
4685 cxx_mark_addressable (TREE_OPERAND (x, 0));
4693 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4696 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4698 tree orig_ifexp = ifexp;
4699 tree orig_op1 = op1;
4700 tree orig_op2 = op2;
4703 if (processing_template_decl)
4705 /* The standard says that the expression is type-dependent if
4706 IFEXP is type-dependent, even though the eventual type of the
4707 expression doesn't dependent on IFEXP. */
4708 if (type_dependent_expression_p (ifexp)
4709 /* As a GNU extension, the middle operand may be omitted. */
4710 || (op1 && type_dependent_expression_p (op1))
4711 || type_dependent_expression_p (op2))
4712 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4713 ifexp = build_non_dependent_expr (ifexp);
4715 op1 = build_non_dependent_expr (op1);
4716 op2 = build_non_dependent_expr (op2);
4719 expr = build_conditional_expr (ifexp, op1, op2);
4720 if (processing_template_decl && expr != error_mark_node)
4721 return build_min_non_dep (COND_EXPR, expr,
4722 orig_ifexp, orig_op1, orig_op2);
4726 /* Given a list of expressions, return a compound expression
4727 that performs them all and returns the value of the last of them. */
4729 tree build_x_compound_expr_from_list (tree list, const char *msg)
4731 tree expr = TREE_VALUE (list);
4733 if (TREE_CHAIN (list))
4736 pedwarn ("%s expression list treated as compound expression", msg);
4738 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4739 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4745 /* Handle overloading of the ',' operator when needed. */
4748 build_x_compound_expr (tree op1, tree op2)
4751 tree orig_op1 = op1;
4752 tree orig_op2 = op2;
4754 if (processing_template_decl)
4756 if (type_dependent_expression_p (op1)
4757 || type_dependent_expression_p (op2))
4758 return build_min_nt (COMPOUND_EXPR, op1, op2);
4759 op1 = build_non_dependent_expr (op1);
4760 op2 = build_non_dependent_expr (op2);
4763 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4764 /*overloaded_p=*/NULL);
4766 result = build_compound_expr (op1, op2);
4768 if (processing_template_decl && result != error_mark_node)
4769 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4774 /* Build a compound expression. */
4777 build_compound_expr (tree lhs, tree rhs)
4779 lhs = convert_to_void (lhs, "left-hand operand of comma");
4781 if (lhs == error_mark_node || rhs == error_mark_node)
4782 return error_mark_node;
4784 if (TREE_CODE (rhs) == TARGET_EXPR)
4786 /* If the rhs is a TARGET_EXPR, then build the compound
4787 expression inside the target_expr's initializer. This
4788 helps the compiler to eliminate unnecessary temporaries. */
4789 tree init = TREE_OPERAND (rhs, 1);
4791 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4792 TREE_OPERAND (rhs, 1) = init;
4797 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4800 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4801 casts away constness. DIAG_FN gives the function to call if we
4802 need to issue a diagnostic; if it is NULL, no diagnostic will be
4803 issued. DESCRIPTION explains what operation is taking place. */
4806 check_for_casting_away_constness (tree src_type, tree dest_type,
4807 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4808 const char *description)
4810 if (diag_fn && casts_away_constness (src_type, dest_type))
4811 diag_fn ("%s from type %qT to type %qT casts away constness",
4812 description, src_type, dest_type);
4815 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4816 (another pointer-to-member type in the same hierarchy) and return
4817 the converted expression. If ALLOW_INVERSE_P is permitted, a
4818 pointer-to-derived may be converted to pointer-to-base; otherwise,
4819 only the other direction is permitted. If C_CAST_P is true, this
4820 conversion is taking place as part of a C-style cast. */
4823 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4826 if (TYPE_PTRMEM_P (type))
4830 if (TREE_CODE (expr) == PTRMEM_CST)
4831 expr = cplus_expand_constant (expr);
4832 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4833 TYPE_PTRMEM_CLASS_TYPE (type),
4836 if (!integer_zerop (delta))
4837 expr = cp_build_binary_op (PLUS_EXPR,
4838 build_nop (ptrdiff_type_node, expr),
4840 return build_nop (type, expr);
4843 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4844 allow_inverse_p, c_cast_p);
4847 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4848 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4849 Otherwise, return EXPR unchanged. */
4852 ignore_overflows (tree expr, tree orig)
4854 if (TREE_CODE (expr) == INTEGER_CST
4855 && CONSTANT_CLASS_P (orig)
4856 && TREE_CODE (orig) != STRING_CST
4857 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4859 if (!TREE_OVERFLOW (orig))
4860 /* Ensure constant sharing. */
4861 expr = build_int_cst_wide (TREE_TYPE (expr),
4862 TREE_INT_CST_LOW (expr),
4863 TREE_INT_CST_HIGH (expr));
4866 /* Avoid clobbering a shared constant. */
4867 expr = copy_node (expr);
4868 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4874 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4875 this static_cast is being attempted as one of the possible casts
4876 allowed by a C-style cast. (In that case, accessibility of base
4877 classes is not considered, and it is OK to cast away
4878 constness.) Return the result of the cast. *VALID_P is set to
4879 indicate whether or not the cast was valid. */
4882 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4888 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4891 /* Assume the cast is valid. */
4894 intype = TREE_TYPE (expr);
4896 /* Save casted types in the function's used types hash table. */
4897 used_types_insert (type);
4899 /* Determine what to do when casting away constness. */
4902 /* C-style casts are allowed to cast away constness. With
4903 WARN_CAST_QUAL, we still want to issue a warning. */
4904 diag_fn = warn_cast_qual ? warning0 : NULL;
4909 /* A static_cast may not cast away constness. */
4911 desc = "static_cast";
4914 /* [expr.static.cast]
4916 An lvalue of type "cv1 B", where B is a class type, can be cast
4917 to type "reference to cv2 D", where D is a class derived (clause
4918 _class.derived_) from B, if a valid standard conversion from
4919 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4920 same cv-qualification as, or greater cv-qualification than, cv1,
4921 and B is not a virtual base class of D. */
4922 /* We check this case before checking the validity of "TYPE t =
4923 EXPR;" below because for this case:
4926 struct D : public B { D(const B&); };
4928 void f() { static_cast<const D&>(b); }
4930 we want to avoid constructing a new D. The standard is not
4931 completely clear about this issue, but our interpretation is
4932 consistent with other compilers. */
4933 if (TREE_CODE (type) == REFERENCE_TYPE
4934 && CLASS_TYPE_P (TREE_TYPE (type))
4935 && CLASS_TYPE_P (intype)
4936 && real_lvalue_p (expr)
4937 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4938 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4939 build_pointer_type (TYPE_MAIN_VARIANT
4940 (TREE_TYPE (type))))
4942 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4946 /* There is a standard conversion from "D*" to "B*" even if "B"
4947 is ambiguous or inaccessible. If this is really a
4948 static_cast, then we check both for inaccessibility and
4949 ambiguity. However, if this is a static_cast being performed
4950 because the user wrote a C-style cast, then accessibility is
4952 base = lookup_base (TREE_TYPE (type), intype,
4953 c_cast_p ? ba_unique : ba_check,
4956 /* Convert from "B*" to "D*". This function will check that "B"
4957 is not a virtual base of "D". */
4958 expr = build_base_path (MINUS_EXPR, build_address (expr),
4959 base, /*nonnull=*/false);
4960 /* Convert the pointer to a reference -- but then remember that
4961 there are no expressions with reference type in C++. */
4962 return convert_from_reference (build_nop (type, expr));
4967 /* [expr.static.cast]
4969 An expression e can be explicitly converted to a type T using a
4970 static_cast of the form static_cast<T>(e) if the declaration T
4971 t(e);" is well-formed, for some invented temporary variable
4973 result = perform_direct_initialization_if_possible (type, expr,
4977 result = convert_from_reference (result);
4979 /* Ignore any integer overflow caused by the cast. */
4980 result = ignore_overflows (result, orig);
4982 /* [expr.static.cast]
4984 If T is a reference type, the result is an lvalue; otherwise,
4985 the result is an rvalue. */
4986 if (TREE_CODE (type) != REFERENCE_TYPE)
4987 result = rvalue (result);
4991 /* [expr.static.cast]
4993 Any expression can be explicitly converted to type cv void. */
4994 if (TREE_CODE (type) == VOID_TYPE)
4995 return convert_to_void (expr, /*implicit=*/NULL);
4997 /* [expr.static.cast]
4999 The inverse of any standard conversion sequence (clause _conv_),
5000 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5001 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5002 (_conv.bool_) conversions, can be performed explicitly using
5003 static_cast subject to the restriction that the explicit
5004 conversion does not cast away constness (_expr.const.cast_), and
5005 the following additional rules for specific cases: */
5006 /* For reference, the conversions not excluded are: integral
5007 promotions, floating point promotion, integral conversions,
5008 floating point conversions, floating-integral conversions,
5009 pointer conversions, and pointer to member conversions. */
5012 A value of integral _or enumeration_ type can be explicitly
5013 converted to an enumeration type. */
5014 /* The effect of all that is that any conversion between any two
5015 types which are integral, floating, or enumeration types can be
5017 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5018 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5020 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5022 /* Ignore any integer overflow caused by the cast. */
5023 expr = ignore_overflows (expr, orig);
5027 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5028 && CLASS_TYPE_P (TREE_TYPE (type))
5029 && CLASS_TYPE_P (TREE_TYPE (intype))
5030 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5031 (TREE_TYPE (intype))),
5032 build_pointer_type (TYPE_MAIN_VARIANT
5033 (TREE_TYPE (type)))))
5038 check_for_casting_away_constness (intype, type, diag_fn, desc);
5039 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5040 c_cast_p ? ba_unique : ba_check,
5042 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5045 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5046 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5053 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5054 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5056 if (TYPE_PTRMEM_P (type))
5058 t1 = (build_ptrmem_type
5060 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5061 t2 = (build_ptrmem_type
5063 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5070 if (can_convert (t1, t2))
5073 check_for_casting_away_constness (intype, type, diag_fn,
5075 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5080 /* [expr.static.cast]
5082 An rvalue of type "pointer to cv void" can be explicitly
5083 converted to a pointer to object type. A value of type pointer
5084 to object converted to "pointer to cv void" and back to the
5085 original pointer type will have its original value. */
5086 if (TREE_CODE (intype) == POINTER_TYPE
5087 && VOID_TYPE_P (TREE_TYPE (intype))
5088 && TYPE_PTROB_P (type))
5091 check_for_casting_away_constness (intype, type, diag_fn, desc);
5092 return build_nop (type, expr);
5096 return error_mark_node;
5099 /* Return an expression representing static_cast<TYPE>(EXPR). */
5102 build_static_cast (tree type, tree expr)
5107 if (type == error_mark_node || expr == error_mark_node)
5108 return error_mark_node;
5110 if (processing_template_decl)
5112 expr = build_min (STATIC_CAST_EXPR, type, expr);
5113 /* We don't know if it will or will not have side effects. */
5114 TREE_SIDE_EFFECTS (expr) = 1;
5115 return convert_from_reference (expr);
5118 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5119 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5120 if (TREE_CODE (type) != REFERENCE_TYPE
5121 && TREE_CODE (expr) == NOP_EXPR
5122 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5123 expr = TREE_OPERAND (expr, 0);
5125 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5129 error ("invalid static_cast from type %qT to type %qT",
5130 TREE_TYPE (expr), type);
5131 return error_mark_node;
5134 /* EXPR is an expression with member function or pointer-to-member
5135 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5136 not permitted by ISO C++, but we accept it in some modes. If we
5137 are not in one of those modes, issue a diagnostic. Return the
5138 converted expression. */
5141 convert_member_func_to_ptr (tree type, tree expr)
5146 intype = TREE_TYPE (expr);
5147 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5148 || TREE_CODE (intype) == METHOD_TYPE);
5150 if (pedantic || warn_pmf2ptr)
5151 pedwarn ("converting from %qT to %qT", intype, type);
5153 if (TREE_CODE (intype) == METHOD_TYPE)
5154 expr = build_addr_func (expr);
5155 else if (TREE_CODE (expr) == PTRMEM_CST)
5156 expr = build_address (PTRMEM_CST_MEMBER (expr));
5159 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5160 decl = build_address (decl);
5161 expr = get_member_function_from_ptrfunc (&decl, expr);
5164 return build_nop (type, expr);
5167 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5168 If C_CAST_P is true, this reinterpret cast is being done as part of
5169 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5170 indicate whether or not reinterpret_cast was valid. */
5173 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5178 /* Assume the cast is invalid. */
5182 if (type == error_mark_node || error_operand_p (expr))
5183 return error_mark_node;
5185 intype = TREE_TYPE (expr);
5187 /* Save casted types in the function's used types hash table. */
5188 used_types_insert (type);
5190 /* [expr.reinterpret.cast]
5191 An lvalue expression of type T1 can be cast to the type
5192 "reference to T2" if an expression of type "pointer to T1" can be
5193 explicitly converted to the type "pointer to T2" using a
5194 reinterpret_cast. */
5195 if (TREE_CODE (type) == REFERENCE_TYPE)
5197 if (! real_lvalue_p (expr))
5199 error ("invalid cast of an rvalue expression of type "
5202 return error_mark_node;
5205 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5206 "B" are related class types; the reinterpret_cast does not
5207 adjust the pointer. */
5208 if (TYPE_PTR_P (intype)
5209 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5210 COMPARE_BASE | COMPARE_DERIVED)))
5211 warning (0, "casting %qT to %qT does not dereference pointer",
5214 expr = build_unary_op (ADDR_EXPR, expr, 0);
5215 if (expr != error_mark_node)
5216 expr = build_reinterpret_cast_1
5217 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5219 if (expr != error_mark_node)
5220 expr = build_indirect_ref (expr, 0);
5224 /* As a G++ extension, we consider conversions from member
5225 functions, and pointers to member functions to
5226 pointer-to-function and pointer-to-void types. If
5227 -Wno-pmf-conversions has not been specified,
5228 convert_member_func_to_ptr will issue an error message. */
5229 if ((TYPE_PTRMEMFUNC_P (intype)
5230 || TREE_CODE (intype) == METHOD_TYPE)
5231 && TYPE_PTR_P (type)
5232 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5233 || VOID_TYPE_P (TREE_TYPE (type))))
5234 return convert_member_func_to_ptr (type, expr);
5236 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5237 array-to-pointer, and function-to-pointer conversions are
5239 expr = decay_conversion (expr);
5241 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5242 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5243 if (TREE_CODE (expr) == NOP_EXPR
5244 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5245 expr = TREE_OPERAND (expr, 0);
5247 if (error_operand_p (expr))
5248 return error_mark_node;
5250 intype = TREE_TYPE (expr);
5252 /* [expr.reinterpret.cast]
5253 A pointer can be converted to any integral type large enough to
5255 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5257 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5258 pedwarn ("cast from %qT to %qT loses precision",
5261 /* [expr.reinterpret.cast]
5262 A value of integral or enumeration type can be explicitly
5263 converted to a pointer. */
5264 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5267 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5268 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5269 return fold_if_not_in_template (build_nop (type, expr));
5270 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5271 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5276 check_for_casting_away_constness (intype, type, error,
5277 "reinterpret_cast");
5278 /* Warn about possible alignment problems. */
5279 if (STRICT_ALIGNMENT && warn_cast_align
5280 && !VOID_TYPE_P (type)
5281 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5282 && COMPLETE_TYPE_P (TREE_TYPE (type))
5283 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5284 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5285 warning (0, "cast from %qT to %qT increases required alignment of "
5289 /* We need to strip nops here, because the front end likes to
5290 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5292 strict_aliasing_warning (intype, type, sexpr);
5294 return fold_if_not_in_template (build_nop (type, expr));
5296 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5297 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5300 /* Only issue a warning, as we have always supported this
5301 where possible, and it is necessary in some cases. DR 195
5302 addresses this issue, but as of 2004/10/26 is still in
5304 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5305 return fold_if_not_in_template (build_nop (type, expr));
5307 else if (TREE_CODE (type) == VECTOR_TYPE)
5308 return fold_if_not_in_template (convert_to_vector (type, expr));
5309 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5310 return fold_if_not_in_template (convert_to_integer (type, expr));
5315 error ("invalid cast from type %qT to type %qT", intype, type);
5316 return error_mark_node;
5319 return cp_convert (type, expr);
5323 build_reinterpret_cast (tree type, tree expr)
5325 if (type == error_mark_node || expr == error_mark_node)
5326 return error_mark_node;
5328 if (processing_template_decl)
5330 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5332 if (!TREE_SIDE_EFFECTS (t)
5333 && type_dependent_expression_p (expr))
5334 /* There might turn out to be side effects inside expr. */
5335 TREE_SIDE_EFFECTS (t) = 1;
5336 return convert_from_reference (t);
5339 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5343 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5344 return an appropriate expression. Otherwise, return
5345 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5346 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5347 performing a C-style cast, its value upon return will indicate
5348 whether or not the conversion succeeded. */
5351 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5355 tree reference_type;
5357 /* Callers are responsible for handling error_mark_node as a
5358 destination type. */
5359 gcc_assert (dst_type != error_mark_node);
5360 /* In a template, callers should be building syntactic
5361 representations of casts, not using this machinery. */
5362 gcc_assert (!processing_template_decl);
5364 /* Assume the conversion is invalid. */
5368 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5371 error ("invalid use of const_cast with type %qT, "
5372 "which is not a pointer, "
5373 "reference, nor a pointer-to-data-member type", dst_type);
5374 return error_mark_node;
5377 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5380 error ("invalid use of const_cast with type %qT, which is a pointer "
5381 "or reference to a function type", dst_type);
5382 return error_mark_node;
5385 /* Save casted types in the function's used types hash table. */
5386 used_types_insert (dst_type);
5388 src_type = TREE_TYPE (expr);
5389 /* Expressions do not really have reference types. */
5390 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5391 src_type = TREE_TYPE (src_type);
5393 /* [expr.const.cast]
5395 An lvalue of type T1 can be explicitly converted to an lvalue of
5396 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5397 types) if a pointer to T1 can be explicitly converted to the type
5398 pointer to T2 using a const_cast. */
5399 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5401 reference_type = dst_type;
5402 if (! real_lvalue_p (expr))
5405 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5406 src_type, dst_type);
5407 return error_mark_node;
5409 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5410 src_type = build_pointer_type (src_type);
5414 reference_type = NULL_TREE;
5415 /* If the destination type is not a reference type, the
5416 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5417 conversions are performed. */
5418 src_type = type_decays_to (src_type);
5419 if (src_type == error_mark_node)
5420 return error_mark_node;
5423 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5424 && comp_ptr_ttypes_const (dst_type, src_type))
5429 /* This cast is actually a C-style cast. Issue a warning if
5430 the user is making a potentially unsafe cast. */
5432 check_for_casting_away_constness (src_type, dst_type,
5438 expr = build_unary_op (ADDR_EXPR, expr, 0);
5439 expr = build_nop (reference_type, expr);
5440 return convert_from_reference (expr);
5444 expr = decay_conversion (expr);
5445 /* build_c_cast puts on a NOP_EXPR to make the result not an
5446 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5447 non-lvalue context. */
5448 if (TREE_CODE (expr) == NOP_EXPR
5449 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5450 expr = TREE_OPERAND (expr, 0);
5451 return build_nop (dst_type, expr);
5456 error ("invalid const_cast from type %qT to type %qT",
5457 src_type, dst_type);
5458 return error_mark_node;
5462 build_const_cast (tree type, tree expr)
5464 if (type == error_mark_node || error_operand_p (expr))
5465 return error_mark_node;
5467 if (processing_template_decl)
5469 tree t = build_min (CONST_CAST_EXPR, type, expr);
5471 if (!TREE_SIDE_EFFECTS (t)
5472 && type_dependent_expression_p (expr))
5473 /* There might turn out to be side effects inside expr. */
5474 TREE_SIDE_EFFECTS (t) = 1;
5475 return convert_from_reference (t);
5478 return build_const_cast_1 (type, expr, /*complain=*/true,
5482 /* Build an expression representing an explicit C-style cast to type
5483 TYPE of expression EXPR. */
5486 build_c_cast (tree type, tree expr)
5492 if (type == error_mark_node || error_operand_p (expr))
5493 return error_mark_node;
5495 if (processing_template_decl)
5497 tree t = build_min (CAST_EXPR, type,
5498 tree_cons (NULL_TREE, value, NULL_TREE));
5499 /* We don't know if it will or will not have side effects. */
5500 TREE_SIDE_EFFECTS (t) = 1;
5501 return convert_from_reference (t);
5504 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5505 'Class') should always be retained, because this information aids
5506 in method lookup. */
5507 if (objc_is_object_ptr (type)
5508 && objc_is_object_ptr (TREE_TYPE (expr)))
5509 return build_nop (type, expr);
5511 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5512 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5513 if (TREE_CODE (type) != REFERENCE_TYPE
5514 && TREE_CODE (value) == NOP_EXPR
5515 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5516 value = TREE_OPERAND (value, 0);
5518 if (TREE_CODE (type) == ARRAY_TYPE)
5520 /* Allow casting from T1* to T2[] because Cfront allows it.
5521 NIHCL uses it. It is not valid ISO C++ however. */
5522 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5524 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5525 type = build_pointer_type (TREE_TYPE (type));
5529 error ("ISO C++ forbids casting to an array type %qT", type);
5530 return error_mark_node;
5534 if (TREE_CODE (type) == FUNCTION_TYPE
5535 || TREE_CODE (type) == METHOD_TYPE)
5537 error ("invalid cast to function type %qT", type);
5538 return error_mark_node;
5541 /* A C-style cast can be a const_cast. */
5542 result = build_const_cast_1 (type, value, /*complain=*/false,
5547 /* Or a static cast. */
5548 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5550 /* Or a reinterpret_cast. */
5552 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5554 /* The static_cast or reinterpret_cast may be followed by a
5557 /* A valid cast may result in errors if, for example, a
5558 conversion to am ambiguous base class is required. */
5559 && !error_operand_p (result))
5563 /* Non-class rvalues always have cv-unqualified type. */
5564 if (!CLASS_TYPE_P (type))
5565 type = TYPE_MAIN_VARIANT (type);
5566 result_type = TREE_TYPE (result);
5567 if (!CLASS_TYPE_P (result_type))
5568 result_type = TYPE_MAIN_VARIANT (result_type);
5569 /* If the type of RESULT does not match TYPE, perform a
5570 const_cast to make it match. If the static_cast or
5571 reinterpret_cast succeeded, we will differ by at most
5572 cv-qualification, so the follow-on const_cast is guaranteed
5574 if (!same_type_p (non_reference (type), non_reference (result_type)))
5576 result = build_const_cast_1 (type, result, false, &valid_p);
5577 gcc_assert (valid_p);
5582 return error_mark_node;
5585 /* Build an assignment expression of lvalue LHS from value RHS.
5586 MODIFYCODE is the code for a binary operator that we use
5587 to combine the old value of LHS with RHS to get the new value.
5588 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5590 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5593 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5597 tree lhstype = TREE_TYPE (lhs);
5598 tree olhstype = lhstype;
5599 tree olhs = NULL_TREE;
5600 bool plain_assign = (modifycode == NOP_EXPR);
5602 /* Avoid duplicate error messages from operands that had errors. */
5603 if (error_operand_p (lhs) || error_operand_p (rhs))
5604 return error_mark_node;
5606 /* Handle control structure constructs used as "lvalues". */
5607 switch (TREE_CODE (lhs))
5609 /* Handle --foo = 5; as these are valid constructs in C++. */
5610 case PREDECREMENT_EXPR:
5611 case PREINCREMENT_EXPR:
5612 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5613 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5614 stabilize_reference (TREE_OPERAND (lhs, 0)),
5615 TREE_OPERAND (lhs, 1));
5616 return build2 (COMPOUND_EXPR, lhstype,
5618 build_modify_expr (TREE_OPERAND (lhs, 0),
5621 /* Handle (a, b) used as an "lvalue". */
5623 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5625 if (newrhs == error_mark_node)
5626 return error_mark_node;
5627 return build2 (COMPOUND_EXPR, lhstype,
5628 TREE_OPERAND (lhs, 0), newrhs);
5631 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5632 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5633 stabilize_reference (TREE_OPERAND (lhs, 0)),
5634 TREE_OPERAND (lhs, 1));
5635 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5636 if (newrhs == error_mark_node)
5637 return error_mark_node;
5638 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5642 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5643 when neither operand has side-effects. */
5644 if (!lvalue_or_else (lhs, lv_assign))
5645 return error_mark_node;
5647 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5648 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5650 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5651 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5653 TREE_OPERAND (lhs, 0),
5654 TREE_OPERAND (lhs, 1)),
5655 TREE_OPERAND (lhs, 0),
5656 TREE_OPERAND (lhs, 1));
5659 /* Handle (a ? b : c) used as an "lvalue". */
5662 /* Produce (a ? (b = rhs) : (c = rhs))
5663 except that the RHS goes through a save-expr
5664 so the code to compute it is only emitted once. */
5666 tree preeval = NULL_TREE;
5668 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5670 error ("void value not ignored as it ought to be");
5671 return error_mark_node;
5674 rhs = stabilize_expr (rhs, &preeval);
5676 /* Check this here to avoid odd errors when trying to convert
5677 a throw to the type of the COND_EXPR. */
5678 if (!lvalue_or_else (lhs, lv_assign))
5679 return error_mark_node;
5681 cond = build_conditional_expr
5682 (TREE_OPERAND (lhs, 0),
5683 build_modify_expr (TREE_OPERAND (lhs, 1),
5685 build_modify_expr (TREE_OPERAND (lhs, 2),
5688 if (cond == error_mark_node)
5690 /* Make sure the code to compute the rhs comes out
5691 before the split. */
5693 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5701 if (modifycode == INIT_EXPR)
5703 if (TREE_CODE (rhs) == CONSTRUCTOR)
5705 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5706 /* Call convert to generate an error; see PR 11063. */
5707 rhs = convert (lhstype, rhs);
5708 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5709 TREE_SIDE_EFFECTS (result) = 1;
5712 else if (! IS_AGGR_TYPE (lhstype))
5713 /* Do the default thing. */;
5716 result = build_special_member_call (lhs, complete_ctor_identifier,
5717 build_tree_list (NULL_TREE, rhs),
5718 lhstype, LOOKUP_NORMAL);
5719 if (result == NULL_TREE)
5720 return error_mark_node;
5726 lhs = require_complete_type (lhs);
5727 if (lhs == error_mark_node)
5728 return error_mark_node;
5730 if (modifycode == NOP_EXPR)
5732 /* `operator=' is not an inheritable operator. */
5733 if (! IS_AGGR_TYPE (lhstype))
5734 /* Do the default thing. */;
5737 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5738 lhs, rhs, make_node (NOP_EXPR),
5739 /*overloaded_p=*/NULL);
5740 if (result == NULL_TREE)
5741 return error_mark_node;
5748 /* A binary op has been requested. Combine the old LHS
5749 value with the RHS producing the value we should actually
5750 store into the LHS. */
5752 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5753 lhs = stabilize_reference (lhs);
5754 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5755 if (newrhs == error_mark_node)
5757 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5758 TREE_TYPE (lhs), TREE_TYPE (rhs));
5759 return error_mark_node;
5762 /* Now it looks like a plain assignment. */
5763 modifycode = NOP_EXPR;
5765 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5766 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5769 /* The left-hand side must be an lvalue. */
5770 if (!lvalue_or_else (lhs, lv_assign))
5771 return error_mark_node;
5773 /* Warn about modifying something that is `const'. Don't warn if
5774 this is initialization. */
5775 if (modifycode != INIT_EXPR
5776 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5777 /* Functions are not modifiable, even though they are
5779 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5780 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5781 /* If it's an aggregate and any field is const, then it is
5782 effectively const. */
5783 || (CLASS_TYPE_P (lhstype)
5784 && C_TYPE_FIELDS_READONLY (lhstype))))
5785 readonly_error (lhs, "assignment");
5787 /* If storing into a structure or union member, it has probably been
5788 given type `int'. Compute the type that would go with the actual
5789 amount of storage the member occupies. */
5791 if (TREE_CODE (lhs) == COMPONENT_REF
5792 && (TREE_CODE (lhstype) == INTEGER_TYPE
5793 || TREE_CODE (lhstype) == REAL_TYPE
5794 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5796 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5798 /* If storing in a field that is in actuality a short or narrower
5799 than one, we must store in the field in its actual type. */
5801 if (lhstype != TREE_TYPE (lhs))
5803 /* Avoid warnings converting integral types back into enums for
5805 if (TREE_CODE (lhstype) == INTEGER_TYPE
5806 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5808 if (TREE_SIDE_EFFECTS (lhs))
5809 lhs = stabilize_reference (lhs);
5812 lhs = copy_node (lhs);
5813 TREE_TYPE (lhs) = lhstype;
5817 /* Convert new value to destination type. */
5819 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5823 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5824 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5826 error ("incompatible types in assignment of %qT to %qT",
5827 TREE_TYPE (rhs), lhstype);
5828 return error_mark_node;
5831 /* Allow array assignment in compiler-generated code. */
5832 if (! DECL_ARTIFICIAL (current_function_decl))
5834 /* This routine is used for both initialization and assignment.
5835 Make sure the diagnostic message differentiates the context. */
5836 if (modifycode == INIT_EXPR)
5837 error ("array used as initializer");
5839 error ("invalid array assignment");
5840 return error_mark_node;
5843 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5844 ? 1 + (modifycode != INIT_EXPR): 0;
5845 return build_vec_init (lhs, NULL_TREE, newrhs,
5846 /*explicit_default_init_p=*/false,
5850 if (modifycode == INIT_EXPR)
5851 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5852 "initialization", NULL_TREE, 0);
5855 /* Avoid warnings on enum bit fields. */
5856 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5857 && TREE_CODE (lhstype) == INTEGER_TYPE)
5859 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5861 newrhs = convert_force (lhstype, newrhs, 0);
5864 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5866 if (TREE_CODE (newrhs) == CALL_EXPR
5867 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5868 newrhs = build_cplus_new (lhstype, newrhs);
5870 /* Can't initialize directly from a TARGET_EXPR, since that would
5871 cause the lhs to be constructed twice, and possibly result in
5872 accidental self-initialization. So we force the TARGET_EXPR to be
5873 expanded without a target. */
5874 if (TREE_CODE (newrhs) == TARGET_EXPR)
5875 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5876 TREE_OPERAND (newrhs, 0));
5879 if (newrhs == error_mark_node)
5880 return error_mark_node;
5882 if (c_dialect_objc () && flag_objc_gc)
5884 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5890 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5891 lhstype, lhs, newrhs);
5893 TREE_SIDE_EFFECTS (result) = 1;
5895 TREE_NO_WARNING (result) = 1;
5897 /* If we got the LHS in a different type for storing in,
5898 convert the result back to the nominal type of LHS
5899 so that the value we return always has the same type
5900 as the LHS argument. */
5902 if (olhstype == TREE_TYPE (result))
5906 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5907 TREE_NO_WARNING (result) = 1;
5910 return convert_for_assignment (olhstype, result, "assignment",
5915 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5917 if (processing_template_decl)
5918 return build_min_nt (MODOP_EXPR, lhs,
5919 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5921 if (modifycode != NOP_EXPR)
5923 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5924 make_node (modifycode),
5925 /*overloaded_p=*/NULL);
5928 TREE_NO_WARNING (rval) = 1;
5932 return build_modify_expr (lhs, modifycode, rhs);
5936 /* Get difference in deltas for different pointer to member function
5937 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5938 the conversion is invalid, the constant is zero. If
5939 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5940 If C_CAST_P is true this conversion is taking place as part of a
5943 Note that the naming of FROM and TO is kind of backwards; the return
5944 value is what we add to a TO in order to get a FROM. They are named
5945 this way because we call this function to find out how to convert from
5946 a pointer to member of FROM to a pointer to member of TO. */
5949 get_delta_difference (tree from, tree to,
5950 bool allow_inverse_p,
5957 /* Assume no conversion is required. */
5958 result = integer_zero_node;
5959 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5960 if (kind == bk_inaccessible || kind == bk_ambig)
5961 error (" in pointer to member function conversion");
5964 if (kind != bk_via_virtual)
5965 result = BINFO_OFFSET (binfo);
5968 tree virt_binfo = binfo_from_vbase (binfo);
5970 /* This is a reinterpret cast, we choose to do nothing. */
5971 if (allow_inverse_p)
5972 warning (0, "pointer to member cast via virtual base %qT",
5973 BINFO_TYPE (virt_binfo));
5975 error ("pointer to member conversion via virtual base %qT",
5976 BINFO_TYPE (virt_binfo));
5979 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5980 /* Pointer to member of incomplete class is permitted*/;
5981 else if (!allow_inverse_p)
5983 error_not_base_type (from, to);
5984 error (" in pointer to member conversion");
5988 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5991 if (kind != bk_via_virtual)
5992 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5995 /* This is a reinterpret cast, we choose to do nothing. */
5996 tree virt_binfo = binfo_from_vbase (binfo);
5998 warning (0, "pointer to member cast via virtual base %qT",
5999 BINFO_TYPE (virt_binfo));
6004 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6008 /* Return a constructor for the pointer-to-member-function TYPE using
6009 the other components as specified. */
6012 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6017 VEC(constructor_elt, gc) *v;
6019 /* Pull the FIELD_DECLs out of the type. */
6020 pfn_field = TYPE_FIELDS (type);
6021 delta_field = TREE_CHAIN (pfn_field);
6023 /* Make sure DELTA has the type we want. */
6024 delta = convert_and_check (delta_type_node, delta);
6026 /* Finish creating the initializer. */
6027 v = VEC_alloc(constructor_elt, gc, 2);
6028 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6029 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6030 u = build_constructor (type, v);
6031 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6032 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6033 TREE_STATIC (u) = (TREE_CONSTANT (u)
6034 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6036 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6041 /* Build a constructor for a pointer to member function. It can be
6042 used to initialize global variables, local variable, or used
6043 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6046 If FORCE is nonzero, then force this conversion, even if
6047 we would rather not do it. Usually set when using an explicit
6048 cast. A C-style cast is being processed iff C_CAST_P is true.
6050 Return error_mark_node, if something goes wrong. */
6053 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6059 if (error_operand_p (pfn))
6060 return error_mark_node;
6062 pfn_type = TREE_TYPE (pfn);
6063 to_type = build_ptrmemfunc_type (type);
6065 /* Handle multiple conversions of pointer to member functions. */
6066 if (TYPE_PTRMEMFUNC_P (pfn_type))
6068 tree delta = NULL_TREE;
6069 tree npfn = NULL_TREE;
6073 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6074 error ("invalid conversion to type %qT from type %qT",
6077 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6078 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6082 /* We don't have to do any conversion to convert a
6083 pointer-to-member to its own type. But, we don't want to
6084 just return a PTRMEM_CST if there's an explicit cast; that
6085 cast should make the expression an invalid template argument. */
6086 if (TREE_CODE (pfn) != PTRMEM_CST)
6088 if (same_type_p (to_type, pfn_type))
6090 else if (integer_zerop (n))
6091 return build_reinterpret_cast (to_type, pfn);
6094 if (TREE_SIDE_EFFECTS (pfn))
6095 pfn = save_expr (pfn);
6097 /* Obtain the function pointer and the current DELTA. */
6098 if (TREE_CODE (pfn) == PTRMEM_CST)
6099 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6102 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6103 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6106 /* Just adjust the DELTA field. */
6107 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6108 (TREE_TYPE (delta), ptrdiff_type_node));
6109 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6110 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6111 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6112 return build_ptrmemfunc1 (to_type, delta, npfn);
6115 /* Handle null pointer to member function conversions. */
6116 if (integer_zerop (pfn))
6118 pfn = build_c_cast (type, integer_zero_node);
6119 return build_ptrmemfunc1 (to_type,
6124 if (type_unknown_p (pfn))
6125 return instantiate_type (type, pfn, tf_warning_or_error);
6127 fn = TREE_OPERAND (pfn, 0);
6128 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6129 /* In a template, we will have preserved the
6131 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6132 return make_ptrmem_cst (to_type, fn);
6135 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6138 ??? There is no consistency as to the types returned for the above
6139 values. Some code acts as if it were a sizetype and some as if it were
6140 integer_type_node. */
6143 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6145 tree type = TREE_TYPE (cst);
6146 tree fn = PTRMEM_CST_MEMBER (cst);
6147 tree ptr_class, fn_class;
6149 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6151 /* The class that the function belongs to. */
6152 fn_class = DECL_CONTEXT (fn);
6154 /* The class that we're creating a pointer to member of. */
6155 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6157 /* First, calculate the adjustment to the function's class. */
6158 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6161 if (!DECL_VIRTUAL_P (fn))
6162 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6165 /* If we're dealing with a virtual function, we have to adjust 'this'
6166 again, to point to the base which provides the vtable entry for
6167 fn; the call will do the opposite adjustment. */
6168 tree orig_class = DECL_CONTEXT (fn);
6169 tree binfo = binfo_or_else (orig_class, fn_class);
6170 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6171 *delta, BINFO_OFFSET (binfo));
6172 *delta = fold_if_not_in_template (*delta);
6174 /* We set PFN to the vtable offset at which the function can be
6175 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6176 case delta is shifted left, and then incremented). */
6177 *pfn = DECL_VINDEX (fn);
6178 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6179 TYPE_SIZE_UNIT (vtable_entry_type));
6180 *pfn = fold_if_not_in_template (*pfn);
6182 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6184 case ptrmemfunc_vbit_in_pfn:
6185 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6187 *pfn = fold_if_not_in_template (*pfn);
6190 case ptrmemfunc_vbit_in_delta:
6191 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6192 *delta, integer_one_node);
6193 *delta = fold_if_not_in_template (*delta);
6194 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6195 *delta, integer_one_node);
6196 *delta = fold_if_not_in_template (*delta);
6203 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6204 *pfn = fold_if_not_in_template (*pfn);
6208 /* Return an expression for PFN from the pointer-to-member function
6212 pfn_from_ptrmemfunc (tree t)
6214 if (TREE_CODE (t) == PTRMEM_CST)
6219 expand_ptrmemfunc_cst (t, &delta, &pfn);
6224 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6227 /* Convert value RHS to type TYPE as preparation for an assignment to
6228 an lvalue of type TYPE. ERRTYPE is a string to use in error
6229 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6230 are doing the conversion in order to pass the PARMNUMth argument of
6234 convert_for_assignment (tree type, tree rhs,
6235 const char *errtype, tree fndecl, int parmnum)
6238 enum tree_code coder;
6240 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6241 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6242 rhs = TREE_OPERAND (rhs, 0);
6244 rhstype = TREE_TYPE (rhs);
6245 coder = TREE_CODE (rhstype);
6247 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6248 && vector_types_convertible_p (type, rhstype, true))
6249 return convert (type, rhs);
6251 if (rhs == error_mark_node || rhstype == error_mark_node)
6252 return error_mark_node;
6253 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6254 return error_mark_node;
6256 /* The RHS of an assignment cannot have void type. */
6257 if (coder == VOID_TYPE)
6259 error ("void value not ignored as it ought to be");
6260 return error_mark_node;
6263 /* Simplify the RHS if possible. */
6264 if (TREE_CODE (rhs) == CONST_DECL)
6265 rhs = DECL_INITIAL (rhs);
6267 if (c_dialect_objc ())
6270 tree rname = fndecl;
6272 if (!strcmp (errtype, "assignment"))
6274 else if (!strcmp (errtype, "initialization"))
6278 tree selector = objc_message_selector ();
6282 if (selector && parmno > 1)
6289 if (objc_compare_types (type, rhstype, parmno, rname))
6290 return convert (type, rhs);
6295 The expression is implicitly converted (clause _conv_) to the
6296 cv-unqualified type of the left operand.
6298 We allow bad conversions here because by the time we get to this point
6299 we are committed to doing the conversion. If we end up doing a bad
6300 conversion, convert_like will complain. */
6301 if (!can_convert_arg_bad (type, rhstype, rhs))
6303 /* When -Wno-pmf-conversions is use, we just silently allow
6304 conversions from pointers-to-members to plain pointers. If
6305 the conversion doesn't work, cp_convert will complain. */
6307 && TYPE_PTR_P (type)
6308 && TYPE_PTRMEMFUNC_P (rhstype))
6309 rhs = cp_convert (strip_top_quals (type), rhs);
6312 /* If the right-hand side has unknown type, then it is an
6313 overloaded function. Call instantiate_type to get error
6315 if (rhstype == unknown_type_node)
6316 instantiate_type (type, rhs, tf_warning_or_error);
6318 error ("cannot convert %qT to %qT for argument %qP to %qD",
6319 rhstype, type, parmnum, fndecl);
6321 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6322 return error_mark_node;
6325 if (warn_missing_format_attribute)
6327 const enum tree_code codel = TREE_CODE (type);
6328 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6330 && check_missing_format_attribute (type, rhstype))
6331 warning (OPT_Wmissing_format_attribute,
6332 "%s might be a candidate for a format attribute",
6336 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6338 if (warn_parentheses
6339 && type == boolean_type_node
6340 && TREE_CODE (rhs) == MODIFY_EXPR
6341 && !TREE_NO_WARNING (rhs)
6342 && TREE_TYPE (rhs) != boolean_type_node)
6344 warning (OPT_Wparentheses,
6345 "suggest parentheses around assignment used as truth value");
6346 TREE_NO_WARNING (rhs) = 1;
6349 return perform_implicit_conversion (strip_top_quals (type), rhs);
6352 /* Convert RHS to be of type TYPE.
6353 If EXP is nonzero, it is the target of the initialization.
6354 ERRTYPE is a string to use in error messages.
6356 Two major differences between the behavior of
6357 `convert_for_assignment' and `convert_for_initialization'
6358 are that references are bashed in the former, while
6359 copied in the latter, and aggregates are assigned in
6360 the former (operator=) while initialized in the
6363 If using constructor make sure no conversion operator exists, if one does
6364 exist, an ambiguity exists.
6366 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6369 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6370 const char *errtype, tree fndecl, int parmnum)
6372 enum tree_code codel = TREE_CODE (type);
6374 enum tree_code coder;
6376 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6377 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6378 if (TREE_CODE (rhs) == NOP_EXPR
6379 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6380 && codel != REFERENCE_TYPE)
6381 rhs = TREE_OPERAND (rhs, 0);
6383 if (type == error_mark_node
6384 || rhs == error_mark_node
6385 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6386 return error_mark_node;
6388 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6389 && TREE_CODE (type) != ARRAY_TYPE
6390 && (TREE_CODE (type) != REFERENCE_TYPE
6391 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6392 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6393 && (TREE_CODE (type) != REFERENCE_TYPE
6394 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6395 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6396 rhs = decay_conversion (rhs);
6398 rhstype = TREE_TYPE (rhs);
6399 coder = TREE_CODE (rhstype);
6401 if (coder == ERROR_MARK)
6402 return error_mark_node;
6404 /* We accept references to incomplete types, so we can
6405 return here before checking if RHS is of complete type. */
6407 if (codel == REFERENCE_TYPE)
6409 /* This should eventually happen in convert_arguments. */
6410 int savew = 0, savee = 0;
6413 savew = warningcount, savee = errorcount;
6414 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6418 if (warningcount > savew)
6419 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6420 else if (errorcount > savee)
6421 error ("in passing argument %P of %q+D", parmnum, fndecl);
6427 exp = require_complete_type (exp);
6428 if (exp == error_mark_node)
6429 return error_mark_node;
6431 rhstype = non_reference (rhstype);
6433 type = complete_type (type);
6435 if (IS_AGGR_TYPE (type))
6436 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6438 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6441 /* If RETVAL is the address of, or a reference to, a local variable or
6442 temporary give an appropriate warning. */
6445 maybe_warn_about_returning_address_of_local (tree retval)
6447 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6448 tree whats_returned = retval;
6452 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6453 whats_returned = TREE_OPERAND (whats_returned, 1);
6454 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6455 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6456 || TREE_CODE (whats_returned) == NOP_EXPR)
6457 whats_returned = TREE_OPERAND (whats_returned, 0);
6462 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6464 whats_returned = TREE_OPERAND (whats_returned, 0);
6466 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6468 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6469 || TREE_CODE (whats_returned) == TARGET_EXPR)
6471 warning (0, "returning reference to temporary");
6474 if (TREE_CODE (whats_returned) == VAR_DECL
6475 && DECL_NAME (whats_returned)
6476 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6478 warning (0, "reference to non-lvalue returned");
6483 while (TREE_CODE (whats_returned) == COMPONENT_REF
6484 || TREE_CODE (whats_returned) == ARRAY_REF)
6485 whats_returned = TREE_OPERAND (whats_returned, 0);
6487 if (DECL_P (whats_returned)
6488 && DECL_NAME (whats_returned)
6489 && DECL_FUNCTION_SCOPE_P (whats_returned)
6490 && !(TREE_STATIC (whats_returned)
6491 || TREE_PUBLIC (whats_returned)))
6493 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6494 warning (0, "reference to local variable %q+D returned",
6497 warning (0, "address of local variable %q+D returned",
6503 /* Check that returning RETVAL from the current function is valid.
6504 Return an expression explicitly showing all conversions required to
6505 change RETVAL into the function return type, and to assign it to
6506 the DECL_RESULT for the function. Set *NO_WARNING to true if
6507 code reaches end of non-void function warning shouldn't be issued
6508 on this RETURN_EXPR. */
6511 check_return_expr (tree retval, bool *no_warning)
6514 /* The type actually returned by the function, after any
6517 int fn_returns_value_p;
6519 *no_warning = false;
6521 /* A `volatile' function is one that isn't supposed to return, ever.
6522 (This is a G++ extension, used to get better code for functions
6523 that call the `volatile' function.) */
6524 if (TREE_THIS_VOLATILE (current_function_decl))
6525 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6527 /* Check for various simple errors. */
6528 if (DECL_DESTRUCTOR_P (current_function_decl))
6531 error ("returning a value from a destructor");
6534 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6536 if (in_function_try_handler)
6537 /* If a return statement appears in a handler of the
6538 function-try-block of a constructor, the program is ill-formed. */
6539 error ("cannot return from a handler of a function-try-block of a constructor");
6541 /* You can't return a value from a constructor. */
6542 error ("returning a value from a constructor");
6546 if (processing_template_decl)
6548 current_function_returns_value = 1;
6549 check_for_bare_parameter_packs (retval);
6553 /* When no explicit return-value is given in a function with a named
6554 return value, the named return value is used. */
6555 result = DECL_RESULT (current_function_decl);
6556 valtype = TREE_TYPE (result);
6557 gcc_assert (valtype != NULL_TREE);
6558 fn_returns_value_p = !VOID_TYPE_P (valtype);
6559 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6562 /* Check for a return statement with no return value in a function
6563 that's supposed to return a value. */
6564 if (!retval && fn_returns_value_p)
6566 pedwarn ("return-statement with no value, in function returning %qT",
6568 /* Clear this, so finish_function won't say that we reach the
6569 end of a non-void function (which we don't, we gave a
6571 current_function_returns_null = 0;
6572 /* And signal caller that TREE_NO_WARNING should be set on the
6573 RETURN_EXPR to avoid control reaches end of non-void function
6574 warnings in tree-cfg.c. */
6577 /* Check for a return statement with a value in a function that
6578 isn't supposed to return a value. */
6579 else if (retval && !fn_returns_value_p)
6581 if (VOID_TYPE_P (TREE_TYPE (retval)))
6582 /* You can return a `void' value from a function of `void'
6583 type. In that case, we have to evaluate the expression for
6584 its side-effects. */
6585 finish_expr_stmt (retval);
6587 pedwarn ("return-statement with a value, in function "
6588 "returning 'void'");
6590 current_function_returns_null = 1;
6592 /* There's really no value to return, after all. */
6596 /* Remember that this function can sometimes return without a
6598 current_function_returns_null = 1;
6600 /* Remember that this function did return a value. */
6601 current_function_returns_value = 1;
6603 /* Check for erroneous operands -- but after giving ourselves a
6604 chance to provide an error about returning a value from a void
6606 if (error_operand_p (retval))
6608 current_function_return_value = error_mark_node;
6609 return error_mark_node;
6612 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6613 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6614 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6615 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6617 && null_ptr_cst_p (retval))
6618 warning (0, "%<operator new%> must not return NULL unless it is "
6619 "declared %<throw()%> (or -fcheck-new is in effect)");
6621 /* Effective C++ rule 15. See also start_function. */
6623 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6627 /* The function return type must be a reference to the current
6629 if (TREE_CODE (valtype) == REFERENCE_TYPE
6630 && same_type_ignoring_top_level_qualifiers_p
6631 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6633 /* Returning '*this' is obviously OK. */
6634 if (retval == current_class_ref)
6636 /* If we are calling a function whose return type is the same of
6637 the current class reference, it is ok. */
6638 else if (TREE_CODE (retval) == INDIRECT_REF
6639 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6644 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6647 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6649 [...] For a function with a class return type, if the expression
6650 in the return statement is the name of a local object, and the cv-
6651 unqualified type of the local object is the same as the function
6652 return type, an implementation is permitted to omit creating the tem-
6653 porary object to hold the function return value [...]
6655 So, if this is a value-returning function that always returns the same
6656 local variable, remember it.
6658 It might be nice to be more flexible, and choose the first suitable
6659 variable even if the function sometimes returns something else, but
6660 then we run the risk of clobbering the variable we chose if the other
6661 returned expression uses the chosen variable somehow. And people expect
6662 this restriction, anyway. (jason 2000-11-19)
6664 See finish_function and finalize_nrv for the rest of this optimization. */
6666 if (fn_returns_value_p && flag_elide_constructors)
6668 if (retval != NULL_TREE
6669 && (current_function_return_value == NULL_TREE
6670 || current_function_return_value == retval)
6671 && TREE_CODE (retval) == VAR_DECL
6672 && DECL_CONTEXT (retval) == current_function_decl
6673 && ! TREE_STATIC (retval)
6674 && (DECL_ALIGN (retval)
6675 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6676 && same_type_p ((TYPE_MAIN_VARIANT
6677 (TREE_TYPE (retval))),
6679 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6680 current_function_return_value = retval;
6682 current_function_return_value = error_mark_node;
6685 /* We don't need to do any conversions when there's nothing being
6690 /* Do any required conversions. */
6691 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6692 /* No conversions are required. */
6696 /* The type the function is declared to return. */
6697 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6699 /* The functype's return type will have been set to void, if it
6700 was an incomplete type. Just treat this as 'return;' */
6701 if (VOID_TYPE_P (functype))
6702 return error_mark_node;
6704 /* First convert the value to the function's return type, then
6705 to the type of return value's location to handle the
6706 case that functype is smaller than the valtype. */
6707 retval = convert_for_initialization
6708 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6709 "return", NULL_TREE, 0);
6710 retval = convert (valtype, retval);
6712 /* If the conversion failed, treat this just like `return;'. */
6713 if (retval == error_mark_node)
6715 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6716 else if (! current_function_returns_struct
6717 && TREE_CODE (retval) == TARGET_EXPR
6718 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6719 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6720 TREE_OPERAND (retval, 0));
6722 maybe_warn_about_returning_address_of_local (retval);
6725 /* Actually copy the value returned into the appropriate location. */
6726 if (retval && retval != result)
6727 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6733 /* Returns nonzero if the pointer-type FROM can be converted to the
6734 pointer-type TO via a qualification conversion. If CONSTP is -1,
6735 then we return nonzero if the pointers are similar, and the
6736 cv-qualification signature of FROM is a proper subset of that of TO.
6738 If CONSTP is positive, then all outer pointers have been
6742 comp_ptr_ttypes_real (tree to, tree from, int constp)
6744 bool to_more_cv_qualified = false;
6746 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6748 if (TREE_CODE (to) != TREE_CODE (from))
6751 if (TREE_CODE (from) == OFFSET_TYPE
6752 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6753 TYPE_OFFSET_BASETYPE (to)))
6756 /* Const and volatile mean something different for function types,
6757 so the usual checks are not appropriate. */
6758 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6760 /* In Objective-C++, some types may have been 'volatilized' by
6761 the compiler for EH; when comparing them here, the volatile
6762 qualification must be ignored. */
6763 bool objc_quals_match = objc_type_quals_match (to, from);
6765 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6768 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6772 to_more_cv_qualified = true;
6776 constp &= TYPE_READONLY (to);
6779 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6780 return ((constp >= 0 || to_more_cv_qualified)
6781 && same_type_ignoring_top_level_qualifiers_p (to, from));
6785 /* When comparing, say, char ** to char const **, this function takes
6786 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6787 types to this function. */
6790 comp_ptr_ttypes (tree to, tree from)
6792 return comp_ptr_ttypes_real (to, from, 1);
6795 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6796 type or inheritance-related types, regardless of cv-quals. */
6799 ptr_reasonably_similar (tree to, tree from)
6801 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6803 /* Any target type is similar enough to void. */
6804 if (TREE_CODE (to) == VOID_TYPE
6805 || TREE_CODE (from) == VOID_TYPE)
6808 if (TREE_CODE (to) != TREE_CODE (from))
6811 if (TREE_CODE (from) == OFFSET_TYPE
6812 && comptypes (TYPE_OFFSET_BASETYPE (to),
6813 TYPE_OFFSET_BASETYPE (from),
6814 COMPARE_BASE | COMPARE_DERIVED))
6817 if (TREE_CODE (to) == VECTOR_TYPE
6818 && vector_types_convertible_p (to, from, false))
6821 if (TREE_CODE (to) == INTEGER_TYPE
6822 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6825 if (TREE_CODE (to) == FUNCTION_TYPE)
6828 if (TREE_CODE (to) != POINTER_TYPE)
6830 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6831 COMPARE_BASE | COMPARE_DERIVED);
6835 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6836 pointer-to-member types) are the same, ignoring cv-qualification at
6840 comp_ptr_ttypes_const (tree to, tree from)
6842 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6844 if (TREE_CODE (to) != TREE_CODE (from))
6847 if (TREE_CODE (from) == OFFSET_TYPE
6848 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6849 TYPE_OFFSET_BASETYPE (to)))
6852 if (TREE_CODE (to) != POINTER_TYPE)
6853 return same_type_ignoring_top_level_qualifiers_p (to, from);
6857 /* Returns the type qualifiers for this type, including the qualifiers on the
6858 elements for an array type. */
6861 cp_type_quals (tree type)
6863 type = strip_array_types (type);
6864 if (type == error_mark_node)
6865 return TYPE_UNQUALIFIED;
6866 return TYPE_QUALS (type);
6869 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6873 cp_type_readonly (tree type)
6875 type = strip_array_types (type);
6876 return TYPE_READONLY (type);
6879 /* Returns nonzero if the TYPE contains a mutable member. */
6882 cp_has_mutable_p (tree type)
6884 type = strip_array_types (type);
6886 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6889 /* Apply the TYPE_QUALS to the new DECL. */
6891 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6893 tree type = TREE_TYPE (decl);
6895 if (type == error_mark_node)
6898 if (TREE_CODE (type) == FUNCTION_TYPE
6899 && type_quals != TYPE_UNQUALIFIED)
6901 /* This was an error in C++98 (cv-qualifiers cannot be added to
6902 a function type), but DR 295 makes the code well-formed by
6903 dropping the extra qualifiers. */
6906 tree bad_type = build_qualified_type (type, type_quals);
6907 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6911 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6915 /* Avoid setting TREE_READONLY incorrectly. */
6916 if (/* If the object has a constructor, the constructor may modify
6918 TYPE_NEEDS_CONSTRUCTING (type)
6919 /* If the type isn't complete, we don't know yet if it will need
6921 || !COMPLETE_TYPE_P (type)
6922 /* If the type has a mutable component, that component might be
6924 || TYPE_HAS_MUTABLE_P (type))
6925 type_quals &= ~TYPE_QUAL_CONST;
6927 c_apply_type_quals_to_decl (type_quals, decl);
6930 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6931 exemplar types such that casting T1 to T2 is casting away constness
6932 if and only if there is no implicit conversion from T1 to T2. */
6935 casts_away_constness_r (tree *t1, tree *t2)
6940 /* [expr.const.cast]
6942 For multi-level pointer to members and multi-level mixed pointers
6943 and pointers to members (conv.qual), the "member" aspect of a
6944 pointer to member level is ignored when determining if a const
6945 cv-qualifier has been cast away. */
6946 /* [expr.const.cast]
6948 For two pointer types:
6950 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6951 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6954 casting from X1 to X2 casts away constness if, for a non-pointer
6955 type T there does not exist an implicit conversion (clause
6958 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6962 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6963 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6964 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6966 *t1 = cp_build_qualified_type (void_type_node,
6967 cp_type_quals (*t1));
6968 *t2 = cp_build_qualified_type (void_type_node,
6969 cp_type_quals (*t2));
6973 quals1 = cp_type_quals (*t1);
6974 quals2 = cp_type_quals (*t2);
6976 if (TYPE_PTRMEM_P (*t1))
6977 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6979 *t1 = TREE_TYPE (*t1);
6980 if (TYPE_PTRMEM_P (*t2))
6981 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6983 *t2 = TREE_TYPE (*t2);
6985 casts_away_constness_r (t1, t2);
6986 *t1 = build_pointer_type (*t1);
6987 *t2 = build_pointer_type (*t2);
6988 *t1 = cp_build_qualified_type (*t1, quals1);
6989 *t2 = cp_build_qualified_type (*t2, quals2);
6992 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6996 casts_away_constness (tree t1, tree t2)
6998 if (TREE_CODE (t2) == REFERENCE_TYPE)
7000 /* [expr.const.cast]
7002 Casting from an lvalue of type T1 to an lvalue of type T2
7003 using a reference cast casts away constness if a cast from an
7004 rvalue of type "pointer to T1" to the type "pointer to T2"
7005 casts away constness. */
7006 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7007 return casts_away_constness (build_pointer_type (t1),
7008 build_pointer_type (TREE_TYPE (t2)));
7011 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7012 /* [expr.const.cast]
7014 Casting from an rvalue of type "pointer to data member of X
7015 of type T1" to the type "pointer to data member of Y of type
7016 T2" casts away constness if a cast from an rvalue of type
7017 "pointer to T1" to the type "pointer to T2" casts away
7019 return casts_away_constness
7020 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7021 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7023 /* Casting away constness is only something that makes sense for
7024 pointer or reference types. */
7025 if (TREE_CODE (t1) != POINTER_TYPE
7026 || TREE_CODE (t2) != POINTER_TYPE)
7029 /* Top-level qualifiers don't matter. */
7030 t1 = TYPE_MAIN_VARIANT (t1);
7031 t2 = TYPE_MAIN_VARIANT (t2);
7032 casts_away_constness_r (&t1, &t2);
7033 if (!can_convert (t2, t1))
7039 /* If T is a REFERENCE_TYPE return the type to which T refers.
7040 Otherwise, return T itself. */
7043 non_reference (tree t)
7045 if (TREE_CODE (t) == REFERENCE_TYPE)
7051 /* Return nonzero if REF is an lvalue valid for this language;
7052 otherwise, print an error message and return zero. USE says
7053 how the lvalue is being used and so selects the error message. */
7056 lvalue_or_else (tree ref, enum lvalue_use use)
7058 int win = lvalue_p (ref);