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)))
1029 case REFERENCE_TYPE:
1030 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2))
1032 /* fall through to checks for pointer types */
1035 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1036 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1037 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1043 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1045 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1050 /* Target types must match incl. qualifiers. */
1051 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1055 case TEMPLATE_TYPE_PARM:
1056 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1057 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1058 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1059 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1064 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1065 TYPENAME_TYPE_FULLNAME (t2)))
1067 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1071 case UNBOUND_CLASS_TEMPLATE:
1072 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1074 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1079 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1084 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1085 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1089 case TYPE_PACK_EXPANSION:
1090 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1091 PACK_EXPANSION_PATTERN (t2));
1097 /* If we get here, we know that from a target independent POV the
1098 types are the same. Make sure the target attributes are also
1100 return targetm.comp_type_attributes (t1, t2);
1103 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1104 is a bitwise-or of the COMPARE_* flags. */
1107 comptypes (tree t1, tree t2, int strict)
1109 if (strict == COMPARE_STRICT)
1116 if (t1 == error_mark_node || t2 == error_mark_node)
1119 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1120 /* At least one of the types requires structural equality, so
1121 perform a deep check. */
1122 return structural_comptypes (t1, t2, strict);
1124 if (VERIFY_CANONICAL_TYPES)
1126 result = structural_comptypes (t1, t2, strict);
1128 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1130 /* The two types are structurally equivalent, but their
1131 canonical types were different. This is a failure of the
1132 canonical type propagation code.*/
1134 "canonical types differ for identical types %T and %T",
1139 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1141 /* Two types are structurally different, but the canonical
1142 types are the same. This means we were over-eager in
1143 assigning canonical types. */
1145 "same canonical type node for different types %T and %T",
1154 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1156 else if (strict == COMPARE_STRUCTURAL)
1157 return structural_comptypes (t1, t2, COMPARE_STRICT);
1159 return structural_comptypes (t1, t2, strict);
1162 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1165 at_least_as_qualified_p (tree type1, tree type2)
1167 int q1 = cp_type_quals (type1);
1168 int q2 = cp_type_quals (type2);
1170 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1171 return (q1 & q2) == q2;
1174 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1175 more cv-qualified that TYPE1, and 0 otherwise. */
1178 comp_cv_qualification (tree type1, tree type2)
1180 int q1 = cp_type_quals (type1);
1181 int q2 = cp_type_quals (type2);
1186 if ((q1 & q2) == q2)
1188 else if ((q1 & q2) == q1)
1194 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1195 subset of the cv-qualification signature of TYPE2, and the types
1196 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1199 comp_cv_qual_signature (tree type1, tree type2)
1201 if (comp_ptr_ttypes_real (type2, type1, -1))
1203 else if (comp_ptr_ttypes_real (type1, type2, -1))
1209 /* Subroutines of `comptypes'. */
1211 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1212 equivalent in the sense that functions with those parameter types
1213 can have equivalent types. The two lists must be equivalent,
1214 element by element. */
1217 compparms (tree parms1, tree parms2)
1221 /* An unspecified parmlist matches any specified parmlist
1222 whose argument types don't need default promotions. */
1224 for (t1 = parms1, t2 = parms2;
1226 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1228 /* If one parmlist is shorter than the other,
1229 they fail to match. */
1232 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1239 /* Process a sizeof or alignof expression where the operand is a
1243 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1248 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1249 if (type == error_mark_node)
1250 return error_mark_node;
1252 type = non_reference (type);
1253 if (TREE_CODE (type) == METHOD_TYPE)
1255 if (complain && (pedantic || warn_pointer_arith))
1256 pedwarn ("invalid application of %qs to a member function",
1257 operator_name_info[(int) op].name);
1258 value = size_one_node;
1261 dependent_p = dependent_type_p (type);
1263 complete_type (type);
1265 /* VLA types will have a non-constant size. In the body of an
1266 uninstantiated template, we don't need to try to compute the
1267 value, because the sizeof expression is not an integral
1268 constant expression in that case. And, if we do try to
1269 compute the value, we'll likely end up with SAVE_EXPRs, which
1270 the template substitution machinery does not expect to see. */
1271 || (processing_template_decl
1272 && COMPLETE_TYPE_P (type)
1273 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1275 value = build_min (op, size_type_node, type);
1276 TREE_READONLY (value) = 1;
1280 return c_sizeof_or_alignof_type (complete_type (type),
1285 /* Process a sizeof expression where the operand is an expression. */
1288 cxx_sizeof_expr (tree e)
1290 if (e == error_mark_node)
1291 return error_mark_node;
1293 if (processing_template_decl)
1295 e = build_min (SIZEOF_EXPR, size_type_node, e);
1296 TREE_SIDE_EFFECTS (e) = 0;
1297 TREE_READONLY (e) = 1;
1302 if (TREE_CODE (e) == COMPONENT_REF
1303 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1304 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1306 error ("invalid application of %<sizeof%> to a bit-field");
1309 else if (is_overloaded_fn (e))
1311 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1315 else if (type_unknown_p (e))
1317 cxx_incomplete_type_error (e, TREE_TYPE (e));
1323 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1326 /* Implement the __alignof keyword: Return the minimum required
1327 alignment of E, measured in bytes. For VAR_DECL's and
1328 FIELD_DECL's return DECL_ALIGN (which can be set from an
1329 "aligned" __attribute__ specification). */
1332 cxx_alignof_expr (tree e)
1336 if (e == error_mark_node)
1337 return error_mark_node;
1339 if (processing_template_decl)
1341 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1342 TREE_SIDE_EFFECTS (e) = 0;
1343 TREE_READONLY (e) = 1;
1348 if (TREE_CODE (e) == VAR_DECL)
1349 t = size_int (DECL_ALIGN_UNIT (e));
1350 else if (TREE_CODE (e) == COMPONENT_REF
1351 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1352 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1354 error ("invalid application of %<__alignof%> to a bit-field");
1357 else if (TREE_CODE (e) == COMPONENT_REF
1358 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1359 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1360 else if (is_overloaded_fn (e))
1362 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1366 else if (type_unknown_p (e))
1368 cxx_incomplete_type_error (e, TREE_TYPE (e));
1372 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1374 return fold_convert (size_type_node, t);
1377 /* Process a sizeof or alignof expression E with code OP where the operand
1378 is an expression. */
1381 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1383 if (op == SIZEOF_EXPR)
1384 return cxx_sizeof_expr (e);
1386 return cxx_alignof_expr (e);
1389 /* EXPR is being used in a context that is not a function call.
1394 The expression can be used only as the left-hand operand of a
1395 member function call.
1397 [expr.mptr.operator]
1399 If the result of .* or ->* is a function, then that result can be
1400 used only as the operand for the function call operator ().
1402 by issuing an error message if appropriate. Returns true iff EXPR
1403 violates these rules. */
1406 invalid_nonstatic_memfn_p (tree expr)
1408 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1410 error ("invalid use of non-static member function");
1416 /* If EXP is a reference to a bitfield, and the type of EXP does not
1417 match the declared type of the bitfield, return the declared type
1418 of the bitfield. Otherwise, return NULL_TREE. */
1421 is_bitfield_expr_with_lowered_type (tree exp)
1423 switch (TREE_CODE (exp))
1426 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1428 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1431 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1435 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1441 field = TREE_OPERAND (exp, 1);
1442 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1444 if (same_type_ignoring_top_level_qualifiers_p
1445 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1447 return DECL_BIT_FIELD_TYPE (field);
1455 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1456 bitfield with a lowered type, the type of EXP is returned, rather
1460 unlowered_expr_type (tree exp)
1464 type = is_bitfield_expr_with_lowered_type (exp);
1466 type = TREE_TYPE (exp);
1471 /* Perform the conversions in [expr] that apply when an lvalue appears
1472 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1473 function-to-pointer conversions. In addition, manifest constants
1474 are replaced by their values, and bitfield references are converted
1475 to their declared types.
1477 Although the returned value is being used as an rvalue, this
1478 function does not wrap the returned expression in a
1479 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1480 that the return value is no longer an lvalue. */
1483 decay_conversion (tree exp)
1486 enum tree_code code;
1488 type = TREE_TYPE (exp);
1489 if (type == error_mark_node)
1490 return error_mark_node;
1492 if (type_unknown_p (exp))
1494 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1495 return error_mark_node;
1498 exp = decl_constant_value (exp);
1499 if (error_operand_p (exp))
1500 return error_mark_node;
1502 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1503 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1504 code = TREE_CODE (type);
1505 if (code == VOID_TYPE)
1507 error ("void value not ignored as it ought to be");
1508 return error_mark_node;
1510 if (invalid_nonstatic_memfn_p (exp))
1511 return error_mark_node;
1512 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1513 return build_unary_op (ADDR_EXPR, exp, 0);
1514 if (code == ARRAY_TYPE)
1519 if (TREE_CODE (exp) == INDIRECT_REF)
1520 return build_nop (build_pointer_type (TREE_TYPE (type)),
1521 TREE_OPERAND (exp, 0));
1523 if (TREE_CODE (exp) == COMPOUND_EXPR)
1525 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1526 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1527 TREE_OPERAND (exp, 0), op1);
1531 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1533 error ("invalid use of non-lvalue array");
1534 return error_mark_node;
1537 ptrtype = build_pointer_type (TREE_TYPE (type));
1539 if (TREE_CODE (exp) == VAR_DECL)
1541 if (!cxx_mark_addressable (exp))
1542 return error_mark_node;
1543 adr = build_nop (ptrtype, build_address (exp));
1546 /* This way is better for a COMPONENT_REF since it can
1547 simplify the offset for a component. */
1548 adr = build_unary_op (ADDR_EXPR, exp, 1);
1549 return cp_convert (ptrtype, adr);
1552 /* If a bitfield is used in a context where integral promotion
1553 applies, then the caller is expected to have used
1554 default_conversion. That function promotes bitfields correctly
1555 before calling this function. At this point, if we have a
1556 bitfield referenced, we may assume that is not subject to
1557 promotion, and that, therefore, the type of the resulting rvalue
1558 is the declared type of the bitfield. */
1559 exp = convert_bitfield_to_declared_type (exp);
1561 /* We do not call rvalue() here because we do not want to wrap EXP
1562 in a NON_LVALUE_EXPR. */
1566 Non-class rvalues always have cv-unqualified types. */
1567 type = TREE_TYPE (exp);
1568 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1569 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1574 /* Perform prepatory conversions, as part of the "usual arithmetic
1575 conversions". In particular, as per [expr]:
1577 Whenever an lvalue expression appears as an operand of an
1578 operator that expects the rvalue for that operand, the
1579 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1580 standard conversions are applied to convert the expression to an
1583 In addition, we perform integral promotions here, as those are
1584 applied to both operands to a binary operator before determining
1585 what additional conversions should apply. */
1588 default_conversion (tree exp)
1590 /* Perform the integral promotions first so that bitfield
1591 expressions (which may promote to "int", even if the bitfield is
1592 declared "unsigned") are promoted correctly. */
1593 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1594 exp = perform_integral_promotions (exp);
1595 /* Perform the other conversions. */
1596 exp = decay_conversion (exp);
1601 /* EXPR is an expression with an integral or enumeration type.
1602 Perform the integral promotions in [conv.prom], and return the
1606 perform_integral_promotions (tree expr)
1613 If the bitfield has an enumerated type, it is treated as any
1614 other value of that type for promotion purposes. */
1615 type = is_bitfield_expr_with_lowered_type (expr);
1616 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1617 type = TREE_TYPE (expr);
1618 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1619 promoted_type = type_promotes_to (type);
1620 if (type != promoted_type)
1621 expr = cp_convert (promoted_type, expr);
1625 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1629 inline_conversion (tree exp)
1631 if (TREE_CODE (exp) == FUNCTION_DECL)
1632 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1637 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1638 decay_conversion to one. */
1641 string_conv_p (tree totype, tree exp, int warn)
1645 if (TREE_CODE (totype) != POINTER_TYPE)
1648 t = TREE_TYPE (totype);
1649 if (!same_type_p (t, char_type_node)
1650 && !same_type_p (t, wchar_type_node))
1653 if (TREE_CODE (exp) == STRING_CST)
1655 /* Make sure that we don't try to convert between char and wchar_t. */
1656 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1661 /* Is this a string constant which has decayed to 'const char *'? */
1662 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1663 if (!same_type_p (TREE_TYPE (exp), t))
1666 if (TREE_CODE (exp) != ADDR_EXPR
1667 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1671 /* This warning is not very useful, as it complains about printf. */
1673 warning (OPT_Wwrite_strings,
1674 "deprecated conversion from string constant to %qT",
1680 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1681 can, for example, use as an lvalue. This code used to be in
1682 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1683 expressions, where we're dealing with aggregates. But now it's again only
1684 called from unary_complex_lvalue. The case (in particular) that led to
1685 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1689 rationalize_conditional_expr (enum tree_code code, tree t)
1691 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1692 the first operand is always the one to be used if both operands
1693 are equal, so we know what conditional expression this used to be. */
1694 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1696 tree op0 = TREE_OPERAND (t, 0);
1697 tree op1 = TREE_OPERAND (t, 1);
1699 /* The following code is incorrect if either operand side-effects. */
1700 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1701 && !TREE_SIDE_EFFECTS (op1));
1703 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1704 ? LE_EXPR : GE_EXPR),
1705 op0, TREE_CODE (op0),
1706 op1, TREE_CODE (op1),
1707 /*overloaded_p=*/NULL),
1708 build_unary_op (code, op0, 0),
1709 build_unary_op (code, op1, 0));
1713 build_conditional_expr (TREE_OPERAND (t, 0),
1714 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1715 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1718 /* Given the TYPE of an anonymous union field inside T, return the
1719 FIELD_DECL for the field. If not found return NULL_TREE. Because
1720 anonymous unions can nest, we must also search all anonymous unions
1721 that are directly reachable. */
1724 lookup_anon_field (tree t, tree type)
1728 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1730 if (TREE_STATIC (field))
1732 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1735 /* If we find it directly, return the field. */
1736 if (DECL_NAME (field) == NULL_TREE
1737 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1742 /* Otherwise, it could be nested, search harder. */
1743 if (DECL_NAME (field) == NULL_TREE
1744 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1746 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1754 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1755 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1756 non-NULL, it indicates the path to the base used to name MEMBER.
1757 If PRESERVE_REFERENCE is true, the expression returned will have
1758 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1759 returned will have the type referred to by the reference.
1761 This function does not perform access control; that is either done
1762 earlier by the parser when the name of MEMBER is resolved to MEMBER
1763 itself, or later when overload resolution selects one of the
1764 functions indicated by MEMBER. */
1767 build_class_member_access_expr (tree object, tree member,
1768 tree access_path, bool preserve_reference)
1772 tree result = NULL_TREE;
1774 if (error_operand_p (object) || error_operand_p (member))
1775 return error_mark_node;
1777 gcc_assert (DECL_P (member) || BASELINK_P (member));
1781 The type of the first expression shall be "class object" (of a
1783 object_type = TREE_TYPE (object);
1784 if (!currently_open_class (object_type)
1785 && !complete_type_or_else (object_type, object))
1786 return error_mark_node;
1787 if (!CLASS_TYPE_P (object_type))
1789 error ("request for member %qD in %qE, which is of non-class type %qT",
1790 member, object, object_type);
1791 return error_mark_node;
1794 /* The standard does not seem to actually say that MEMBER must be a
1795 member of OBJECT_TYPE. However, that is clearly what is
1797 if (DECL_P (member))
1799 member_scope = DECL_CLASS_CONTEXT (member);
1801 if (TREE_DEPRECATED (member))
1802 warn_deprecated_use (member);
1805 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1806 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1807 presently be the anonymous union. Go outwards until we find a
1808 type related to OBJECT_TYPE. */
1809 while (ANON_AGGR_TYPE_P (member_scope)
1810 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1812 member_scope = TYPE_CONTEXT (member_scope);
1813 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1815 if (TREE_CODE (member) == FIELD_DECL)
1816 error ("invalid use of nonstatic data member %qE", member);
1818 error ("%qD is not a member of %qT", member, object_type);
1819 return error_mark_node;
1822 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1823 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1824 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1826 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1828 object = build_indirect_ref (temp, NULL);
1831 /* In [expr.ref], there is an explicit list of the valid choices for
1832 MEMBER. We check for each of those cases here. */
1833 if (TREE_CODE (member) == VAR_DECL)
1835 /* A static data member. */
1837 /* If OBJECT has side-effects, they are supposed to occur. */
1838 if (TREE_SIDE_EFFECTS (object))
1839 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1841 else if (TREE_CODE (member) == FIELD_DECL)
1843 /* A non-static data member. */
1848 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1849 && integer_zerop (TREE_OPERAND (object, 0)));
1851 /* Convert OBJECT to the type of MEMBER. */
1852 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1853 TYPE_MAIN_VARIANT (member_scope)))
1858 binfo = lookup_base (access_path ? access_path : object_type,
1859 member_scope, ba_unique, &kind);
1860 if (binfo == error_mark_node)
1861 return error_mark_node;
1863 /* It is invalid to try to get to a virtual base of a
1864 NULL object. The most common cause is invalid use of
1866 if (null_object_p && kind == bk_via_virtual)
1868 error ("invalid access to non-static data member %qD of "
1871 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1872 return error_mark_node;
1875 /* Convert to the base. */
1876 object = build_base_path (PLUS_EXPR, object, binfo,
1878 /* If we found the base successfully then we should be able
1879 to convert to it successfully. */
1880 gcc_assert (object != error_mark_node);
1883 /* Complain about other invalid uses of offsetof, even though they will
1884 give the right answer. Note that we complain whether or not they
1885 actually used the offsetof macro, since there's no way to know at this
1886 point. So we just give a warning, instead of a pedwarn. */
1887 /* Do not produce this warning for base class field references, because
1888 we know for a fact that didn't come from offsetof. This does occur
1889 in various testsuite cases where a null object is passed where a
1890 vtable access is required. */
1891 if (null_object_p && warn_invalid_offsetof
1892 && CLASSTYPE_NON_POD_P (object_type)
1893 && !DECL_FIELD_IS_BASE (member)
1894 && !skip_evaluation)
1896 warning (0, "invalid access to non-static data member %qD of NULL object",
1898 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1901 /* If MEMBER is from an anonymous aggregate, we have converted
1902 OBJECT so that it refers to the class containing the
1903 anonymous union. Generate a reference to the anonymous union
1904 itself, and recur to find MEMBER. */
1905 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1906 /* When this code is called from build_field_call, the
1907 object already has the type of the anonymous union.
1908 That is because the COMPONENT_REF was already
1909 constructed, and was then disassembled before calling
1910 build_field_call. After the function-call code is
1911 cleaned up, this waste can be eliminated. */
1912 && (!same_type_ignoring_top_level_qualifiers_p
1913 (TREE_TYPE (object), DECL_CONTEXT (member))))
1915 tree anonymous_union;
1917 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1918 DECL_CONTEXT (member));
1919 object = build_class_member_access_expr (object,
1921 /*access_path=*/NULL_TREE,
1922 preserve_reference);
1925 /* Compute the type of the field, as described in [expr.ref]. */
1926 type_quals = TYPE_UNQUALIFIED;
1927 member_type = TREE_TYPE (member);
1928 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1930 type_quals = (cp_type_quals (member_type)
1931 | cp_type_quals (object_type));
1933 /* A field is const (volatile) if the enclosing object, or the
1934 field itself, is const (volatile). But, a mutable field is
1935 not const, even within a const object. */
1936 if (DECL_MUTABLE_P (member))
1937 type_quals &= ~TYPE_QUAL_CONST;
1938 member_type = cp_build_qualified_type (member_type, type_quals);
1941 result = build3 (COMPONENT_REF, member_type, object, member,
1943 result = fold_if_not_in_template (result);
1945 /* Mark the expression const or volatile, as appropriate. Even
1946 though we've dealt with the type above, we still have to mark the
1947 expression itself. */
1948 if (type_quals & TYPE_QUAL_CONST)
1949 TREE_READONLY (result) = 1;
1950 if (type_quals & TYPE_QUAL_VOLATILE)
1951 TREE_THIS_VOLATILE (result) = 1;
1953 else if (BASELINK_P (member))
1955 /* The member is a (possibly overloaded) member function. */
1959 /* If the MEMBER is exactly one static member function, then we
1960 know the type of the expression. Otherwise, we must wait
1961 until overload resolution has been performed. */
1962 functions = BASELINK_FUNCTIONS (member);
1963 if (TREE_CODE (functions) == FUNCTION_DECL
1964 && DECL_STATIC_FUNCTION_P (functions))
1965 type = TREE_TYPE (functions);
1967 type = unknown_type_node;
1968 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1969 base. That will happen when the function is called. */
1970 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1972 else if (TREE_CODE (member) == CONST_DECL)
1974 /* The member is an enumerator. */
1976 /* If OBJECT has side-effects, they are supposed to occur. */
1977 if (TREE_SIDE_EFFECTS (object))
1978 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1983 error ("invalid use of %qD", member);
1984 return error_mark_node;
1987 if (!preserve_reference)
1990 If E2 is declared to have type "reference to T", then ... the
1991 type of E1.E2 is T. */
1992 result = convert_from_reference (result);
1997 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1998 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2001 lookup_destructor (tree object, tree scope, tree dtor_name)
2003 tree object_type = TREE_TYPE (object);
2004 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2007 if (scope && !check_dtor_name (scope, dtor_type))
2009 error ("qualified type %qT does not match destructor name ~%qT",
2011 return error_mark_node;
2013 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2015 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2016 TYPE_MAIN_VARIANT (object_type), dtor_type);
2017 return error_mark_node;
2019 expr = lookup_member (dtor_type, complete_dtor_identifier,
2020 /*protect=*/1, /*want_type=*/false);
2021 expr = (adjust_result_of_qualified_name_lookup
2022 (expr, dtor_type, object_type));
2026 /* An expression of the form "A::template B" has been resolved to
2027 DECL. Issue a diagnostic if B is not a template or template
2031 check_template_keyword (tree decl)
2033 /* The standard says:
2037 If a name prefixed by the keyword template is not a member
2038 template, the program is ill-formed.
2040 DR 228 removed the restriction that the template be a member
2043 DR 96, if accepted would add the further restriction that explicit
2044 template arguments must be provided if the template keyword is
2045 used, but, as of 2005-10-16, that DR is still in "drafting". If
2046 this DR is accepted, then the semantic checks here can be
2047 simplified, as the entity named must in fact be a template
2048 specialization, rather than, as at present, a set of overloaded
2049 functions containing at least one template function. */
2050 if (TREE_CODE (decl) != TEMPLATE_DECL
2051 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2053 if (!is_overloaded_fn (decl))
2054 pedwarn ("%qD is not a template", decl);
2059 if (BASELINK_P (fns))
2060 fns = BASELINK_FUNCTIONS (fns);
2063 tree fn = OVL_CURRENT (fns);
2064 if (TREE_CODE (fn) == TEMPLATE_DECL
2065 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2067 if (TREE_CODE (fn) == FUNCTION_DECL
2068 && DECL_USE_TEMPLATE (fn)
2069 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2071 fns = OVL_NEXT (fns);
2074 pedwarn ("%qD is not a template", decl);
2079 /* This function is called by the parser to process a class member
2080 access expression of the form OBJECT.NAME. NAME is a node used by
2081 the parser to represent a name; it is not yet a DECL. It may,
2082 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2083 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2084 there is no reason to do the lookup twice, so the parser keeps the
2085 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2086 be a template via the use of the "A::template B" syntax. */
2089 finish_class_member_access_expr (tree object, tree name, bool template_p)
2094 tree access_path = NULL_TREE;
2095 tree orig_object = object;
2096 tree orig_name = name;
2098 if (object == error_mark_node || name == error_mark_node)
2099 return error_mark_node;
2101 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2102 if (!objc_is_public (object, name))
2103 return error_mark_node;
2105 object_type = TREE_TYPE (object);
2107 if (processing_template_decl)
2109 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2110 dependent_type_p (object_type)
2111 /* If NAME is just an IDENTIFIER_NODE, then the expression
2113 || TREE_CODE (object) == IDENTIFIER_NODE
2114 /* If NAME is "f<args>", where either 'f' or 'args' is
2115 dependent, then the expression is dependent. */
2116 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2117 && dependent_template_id_p (TREE_OPERAND (name, 0),
2118 TREE_OPERAND (name, 1)))
2119 /* If NAME is "T::X" where "T" is dependent, then the
2120 expression is dependent. */
2121 || (TREE_CODE (name) == SCOPE_REF
2122 && TYPE_P (TREE_OPERAND (name, 0))
2123 && dependent_type_p (TREE_OPERAND (name, 0))))
2124 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2125 object = build_non_dependent_expr (object);
2130 The type of the first expression shall be "class object" (of a
2132 if (!currently_open_class (object_type)
2133 && !complete_type_or_else (object_type, object))
2134 return error_mark_node;
2135 if (!CLASS_TYPE_P (object_type))
2137 error ("request for member %qD in %qE, which is of non-class type %qT",
2138 name, object, object_type);
2139 return error_mark_node;
2142 if (BASELINK_P (name))
2143 /* A member function that has already been looked up. */
2147 bool is_template_id = false;
2148 tree template_args = NULL_TREE;
2151 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2153 is_template_id = true;
2154 template_args = TREE_OPERAND (name, 1);
2155 name = TREE_OPERAND (name, 0);
2157 if (TREE_CODE (name) == OVERLOAD)
2158 name = DECL_NAME (get_first_fn (name));
2159 else if (DECL_P (name))
2160 name = DECL_NAME (name);
2163 if (TREE_CODE (name) == SCOPE_REF)
2165 /* A qualified name. The qualifying class or namespace `S'
2166 has already been looked up; it is either a TYPE or a
2168 scope = TREE_OPERAND (name, 0);
2169 name = TREE_OPERAND (name, 1);
2171 /* If SCOPE is a namespace, then the qualified name does not
2172 name a member of OBJECT_TYPE. */
2173 if (TREE_CODE (scope) == NAMESPACE_DECL)
2175 error ("%<%D::%D%> is not a member of %qT",
2176 scope, name, object_type);
2177 return error_mark_node;
2180 gcc_assert (CLASS_TYPE_P (scope));
2181 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2182 || TREE_CODE (name) == BIT_NOT_EXPR);
2184 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2185 access_path = lookup_base (object_type, scope, ba_check, NULL);
2186 if (access_path == error_mark_node)
2187 return error_mark_node;
2190 error ("%qT is not a base of %qT", scope, object_type);
2191 return error_mark_node;
2197 access_path = object_type;
2200 if (TREE_CODE (name) == BIT_NOT_EXPR)
2201 member = lookup_destructor (object, scope, name);
2204 /* Look up the member. */
2205 member = lookup_member (access_path, name, /*protect=*/1,
2206 /*want_type=*/false);
2207 if (member == NULL_TREE)
2209 error ("%qD has no member named %qE", object_type, name);
2210 return error_mark_node;
2212 if (member == error_mark_node)
2213 return error_mark_node;
2218 tree template = member;
2220 if (BASELINK_P (template))
2221 template = lookup_template_function (template, template_args);
2224 error ("%qD is not a member template function", name);
2225 return error_mark_node;
2230 if (TREE_DEPRECATED (member))
2231 warn_deprecated_use (member);
2234 check_template_keyword (member);
2236 expr = build_class_member_access_expr (object, member, access_path,
2237 /*preserve_reference=*/false);
2238 if (processing_template_decl && expr != error_mark_node)
2240 if (BASELINK_P (member))
2242 if (TREE_CODE (orig_name) == SCOPE_REF)
2243 BASELINK_QUALIFIED_P (member) = 1;
2246 return build_min_non_dep (COMPONENT_REF, expr,
2247 orig_object, orig_name,
2254 /* Return an expression for the MEMBER_NAME field in the internal
2255 representation of PTRMEM, a pointer-to-member function. (Each
2256 pointer-to-member function type gets its own RECORD_TYPE so it is
2257 more convenient to access the fields by name than by FIELD_DECL.)
2258 This routine converts the NAME to a FIELD_DECL and then creates the
2259 node for the complete expression. */
2262 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2268 /* This code is a stripped down version of
2269 build_class_member_access_expr. It does not work to use that
2270 routine directly because it expects the object to be of class
2272 ptrmem_type = TREE_TYPE (ptrmem);
2273 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2274 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2275 /*want_type=*/false);
2276 member_type = cp_build_qualified_type (TREE_TYPE (member),
2277 cp_type_quals (ptrmem_type));
2278 return fold_build3 (COMPONENT_REF, member_type,
2279 ptrmem, member, NULL_TREE);
2282 /* Given an expression PTR for a pointer, return an expression
2283 for the value pointed to.
2284 ERRORSTRING is the name of the operator to appear in error messages.
2286 This function may need to overload OPERATOR_FNNAME.
2287 Must also handle REFERENCE_TYPEs for C++. */
2290 build_x_indirect_ref (tree expr, const char *errorstring)
2292 tree orig_expr = expr;
2295 if (processing_template_decl)
2297 if (type_dependent_expression_p (expr))
2298 return build_min_nt (INDIRECT_REF, expr);
2299 expr = build_non_dependent_expr (expr);
2302 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2303 NULL_TREE, /*overloaded_p=*/NULL);
2305 rval = build_indirect_ref (expr, errorstring);
2307 if (processing_template_decl && rval != error_mark_node)
2308 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2314 build_indirect_ref (tree ptr, const char *errorstring)
2318 if (ptr == error_mark_node)
2319 return error_mark_node;
2321 if (ptr == current_class_ptr)
2322 return current_class_ref;
2324 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2325 ? ptr : decay_conversion (ptr));
2326 type = TREE_TYPE (pointer);
2328 if (POINTER_TYPE_P (type))
2332 If the type of the expression is "pointer to T," the type
2333 of the result is "T."
2335 We must use the canonical variant because certain parts of
2336 the back end, like fold, do pointer comparisons between
2338 tree t = canonical_type_variant (TREE_TYPE (type));
2340 if (TREE_CODE (ptr) == CONVERT_EXPR
2341 || TREE_CODE (ptr) == NOP_EXPR
2342 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2344 /* If a warning is issued, mark it to avoid duplicates from
2345 the backend. This only needs to be done at
2346 warn_strict_aliasing > 2. */
2347 if (warn_strict_aliasing > 2)
2348 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2349 type, TREE_OPERAND (ptr, 0)))
2350 TREE_NO_WARNING (ptr) = 1;
2353 if (VOID_TYPE_P (t))
2355 /* A pointer to incomplete type (other than cv void) can be
2356 dereferenced [expr.unary.op]/1 */
2357 error ("%qT is not a pointer-to-object type", type);
2358 return error_mark_node;
2360 else if (TREE_CODE (pointer) == ADDR_EXPR
2361 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2362 /* The POINTER was something like `&x'. We simplify `*&x' to
2364 return TREE_OPERAND (pointer, 0);
2367 tree ref = build1 (INDIRECT_REF, t, pointer);
2369 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2370 so that we get the proper error message if the result is used
2371 to assign to. Also, &* is supposed to be a no-op. */
2372 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2373 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2374 TREE_SIDE_EFFECTS (ref)
2375 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2379 /* `pointer' won't be an error_mark_node if we were given a
2380 pointer to member, so it's cool to check for this here. */
2381 else if (TYPE_PTR_TO_MEMBER_P (type))
2382 error ("invalid use of %qs on pointer to member", errorstring);
2383 else if (pointer != error_mark_node)
2386 error ("invalid type argument of %qs", errorstring);
2388 error ("invalid type argument");
2390 return error_mark_node;
2393 /* This handles expressions of the form "a[i]", which denotes
2396 This is logically equivalent in C to *(a+i), but we may do it differently.
2397 If A is a variable or a member, we generate a primitive ARRAY_REF.
2398 This avoids forcing the array out of registers, and can work on
2399 arrays that are not lvalues (for example, members of structures returned
2402 If INDEX is of some user-defined type, it must be converted to
2403 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2404 will inherit the type of the array, which will be some pointer type. */
2407 build_array_ref (tree array, tree idx)
2411 error ("subscript missing in array reference");
2412 return error_mark_node;
2415 if (TREE_TYPE (array) == error_mark_node
2416 || TREE_TYPE (idx) == error_mark_node)
2417 return error_mark_node;
2419 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2421 switch (TREE_CODE (array))
2425 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2426 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2427 TREE_OPERAND (array, 0), value);
2431 return build_conditional_expr
2432 (TREE_OPERAND (array, 0),
2433 build_array_ref (TREE_OPERAND (array, 1), idx),
2434 build_array_ref (TREE_OPERAND (array, 2), idx));
2440 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2444 warn_array_subscript_with_type_char (idx);
2446 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2448 error ("array subscript is not an integer");
2449 return error_mark_node;
2452 /* Apply integral promotions *after* noticing character types.
2453 (It is unclear why we do these promotions -- the standard
2454 does not say that we should. In fact, the natural thing would
2455 seem to be to convert IDX to ptrdiff_t; we're performing
2456 pointer arithmetic.) */
2457 idx = perform_integral_promotions (idx);
2459 /* An array that is indexed by a non-constant
2460 cannot be stored in a register; we must be able to do
2461 address arithmetic on its address.
2462 Likewise an array of elements of variable size. */
2463 if (TREE_CODE (idx) != INTEGER_CST
2464 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2465 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2468 if (!cxx_mark_addressable (array))
2469 return error_mark_node;
2472 /* An array that is indexed by a constant value which is not within
2473 the array bounds cannot be stored in a register either; because we
2474 would get a crash in store_bit_field/extract_bit_field when trying
2475 to access a non-existent part of the register. */
2476 if (TREE_CODE (idx) == INTEGER_CST
2477 && TYPE_DOMAIN (TREE_TYPE (array))
2478 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2480 if (!cxx_mark_addressable (array))
2481 return error_mark_node;
2484 if (pedantic && !lvalue_p (array))
2485 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2487 /* Note in C++ it is valid to subscript a `register' array, since
2488 it is valid to take the address of something with that
2489 storage specification. */
2493 while (TREE_CODE (foo) == COMPONENT_REF)
2494 foo = TREE_OPERAND (foo, 0);
2495 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2496 warning (OPT_Wextra, "subscripting array declared %<register%>");
2499 type = TREE_TYPE (TREE_TYPE (array));
2500 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2501 /* Array ref is const/volatile if the array elements are
2502 or if the array is.. */
2503 TREE_READONLY (rval)
2504 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2505 TREE_SIDE_EFFECTS (rval)
2506 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2507 TREE_THIS_VOLATILE (rval)
2508 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2509 return require_complete_type (fold_if_not_in_template (rval));
2513 tree ar = default_conversion (array);
2514 tree ind = default_conversion (idx);
2516 /* Put the integer in IND to simplify error checking. */
2517 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2524 if (ar == error_mark_node)
2527 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2529 error ("subscripted value is neither array nor pointer");
2530 return error_mark_node;
2532 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2534 error ("array subscript is not an integer");
2535 return error_mark_node;
2538 warn_array_subscript_with_type_char (idx);
2540 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2545 /* Resolve a pointer to member function. INSTANCE is the object
2546 instance to use, if the member points to a virtual member.
2548 This used to avoid checking for virtual functions if basetype
2549 has no virtual functions, according to an earlier ANSI draft.
2550 With the final ISO C++ rules, such an optimization is
2551 incorrect: A pointer to a derived member can be static_cast
2552 to pointer-to-base-member, as long as the dynamic object
2553 later has the right member. */
2556 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2558 if (TREE_CODE (function) == OFFSET_REF)
2559 function = TREE_OPERAND (function, 1);
2561 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2563 tree idx, delta, e1, e2, e3, vtbl, basetype;
2564 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2566 tree instance_ptr = *instance_ptrptr;
2567 tree instance_save_expr = 0;
2568 if (instance_ptr == error_mark_node)
2570 if (TREE_CODE (function) == PTRMEM_CST)
2572 /* Extracting the function address from a pmf is only
2573 allowed with -Wno-pmf-conversions. It only works for
2575 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2576 e1 = convert (fntype, e1);
2581 error ("object missing in use of %qE", function);
2582 return error_mark_node;
2586 if (TREE_SIDE_EFFECTS (instance_ptr))
2587 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2589 if (TREE_SIDE_EFFECTS (function))
2590 function = save_expr (function);
2592 /* Start by extracting all the information from the PMF itself. */
2593 e3 = pfn_from_ptrmemfunc (function);
2594 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2595 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2596 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2598 case ptrmemfunc_vbit_in_pfn:
2599 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2600 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2603 case ptrmemfunc_vbit_in_delta:
2604 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2605 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2612 /* Convert down to the right base before using the instance. A
2613 special case is that in a pointer to member of class C, C may
2614 be incomplete. In that case, the function will of course be
2615 a member of C, and no conversion is required. In fact,
2616 lookup_base will fail in that case, because incomplete
2617 classes do not have BINFOs. */
2618 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2619 if (!same_type_ignoring_top_level_qualifiers_p
2620 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2622 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2623 basetype, ba_check, NULL);
2624 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2626 if (instance_ptr == error_mark_node)
2627 return error_mark_node;
2629 /* ...and then the delta in the PMF. */
2630 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
2631 instance_ptr, fold_convert (sizetype, delta));
2633 /* Hand back the adjusted 'this' argument to our caller. */
2634 *instance_ptrptr = instance_ptr;
2636 /* Next extract the vtable pointer from the object. */
2637 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2639 vtbl = build_indirect_ref (vtbl, NULL);
2641 /* Finally, extract the function pointer from the vtable. */
2642 e2 = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
2643 fold_convert (sizetype, idx));
2644 e2 = build_indirect_ref (e2, NULL);
2645 TREE_CONSTANT (e2) = 1;
2646 TREE_INVARIANT (e2) = 1;
2648 /* When using function descriptors, the address of the
2649 vtable entry is treated as a function pointer. */
2650 if (TARGET_VTABLE_USES_DESCRIPTORS)
2651 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2652 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2654 TREE_TYPE (e2) = TREE_TYPE (e3);
2655 e1 = build_conditional_expr (e1, e2, e3);
2657 /* Make sure this doesn't get evaluated first inside one of the
2658 branches of the COND_EXPR. */
2659 if (instance_save_expr)
2660 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2661 instance_save_expr, e1);
2669 build_function_call (tree function, tree params)
2671 tree fntype, fndecl;
2672 tree name = NULL_TREE;
2674 tree original = function;
2675 int nargs, parm_types_len;
2679 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2680 expressions, like those used for ObjC messenger dispatches. */
2681 function = objc_rewrite_function_call (function, params);
2683 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2684 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2685 if (TREE_CODE (function) == NOP_EXPR
2686 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2687 function = TREE_OPERAND (function, 0);
2689 if (TREE_CODE (function) == FUNCTION_DECL)
2691 name = DECL_NAME (function);
2693 mark_used (function);
2696 /* Convert anything with function type to a pointer-to-function. */
2697 if (pedantic && DECL_MAIN_P (function))
2698 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2700 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2701 (because calling an inline function does not mean the function
2702 needs to be separately compiled). */
2704 if (DECL_INLINE (function))
2705 function = inline_conversion (function);
2707 function = build_addr_func (function);
2713 function = build_addr_func (function);
2716 if (function == error_mark_node)
2717 return error_mark_node;
2719 fntype = TREE_TYPE (function);
2721 if (TYPE_PTRMEMFUNC_P (fntype))
2723 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2724 "function in %<%E (...)%>",
2726 return error_mark_node;
2729 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2730 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2732 if (!((TREE_CODE (fntype) == POINTER_TYPE
2733 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2735 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2737 error ("%qE cannot be used as a function", original);
2738 return error_mark_node;
2741 /* fntype now gets the type of function pointed to. */
2742 fntype = TREE_TYPE (fntype);
2743 parm_types = TYPE_ARG_TYPES (fntype);
2745 /* Allocate storage for converted arguments. */
2746 parm_types_len = list_length (parm_types);
2747 nargs = list_length (params);
2748 if (parm_types_len > nargs)
2749 nargs = parm_types_len;
2750 argarray = (tree *) alloca (nargs * sizeof (tree));
2752 /* Convert the parameters to the types declared in the
2753 function prototype, or apply default promotions. */
2754 nargs = convert_arguments (nargs, argarray, parm_types,
2755 params, fndecl, LOOKUP_NORMAL);
2757 return error_mark_node;
2759 /* Check for errors in format strings and inappropriately
2762 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2765 return build_cxx_call (function, nargs, argarray);
2768 /* Convert the actual parameter expressions in the list VALUES
2769 to the types in the list TYPELIST.
2770 If parmdecls is exhausted, or when an element has NULL as its type,
2771 perform the default conversions.
2773 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2775 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2777 This is also where warnings about wrong number of args are generated.
2779 Returns the actual number of arguments processed (which might be less
2780 than NARGS), or -1 on error.
2782 VALUES is a chain of TREE_LIST nodes with the elements of the list
2783 in the TREE_VALUE slots of those nodes.
2785 In C++, unspecified trailing parameters can be filled in with their
2786 default arguments, if such were specified. Do so here. */
2789 convert_arguments (int nargs, tree *argarray,
2790 tree typelist, tree values, tree fndecl, int flags)
2792 tree typetail, valtail;
2793 const char *called_thing = 0;
2796 /* Argument passing is always copy-initialization. */
2797 flags |= LOOKUP_ONLYCONVERTING;
2801 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2803 if (DECL_NAME (fndecl) == NULL_TREE
2804 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2805 called_thing = "constructor";
2807 called_thing = "member function";
2810 called_thing = "function";
2813 for (valtail = values, typetail = typelist;
2815 valtail = TREE_CHAIN (valtail), i++)
2817 tree type = typetail ? TREE_VALUE (typetail) : 0;
2818 tree val = TREE_VALUE (valtail);
2820 if (val == error_mark_node || type == error_mark_node)
2823 if (type == void_type_node)
2827 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2828 error ("at this point in file");
2831 error ("too many arguments to function");
2835 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2836 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2837 if (TREE_CODE (val) == NOP_EXPR
2838 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2839 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2840 val = TREE_OPERAND (val, 0);
2842 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2844 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2845 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2846 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2847 val = decay_conversion (val);
2850 if (val == error_mark_node)
2855 /* Formal parm type is specified by a function prototype. */
2858 if (!COMPLETE_TYPE_P (complete_type (type)))
2861 error ("parameter %P of %qD has incomplete type %qT",
2864 error ("parameter %P has incomplete type %qT", i, type);
2865 parmval = error_mark_node;
2869 parmval = convert_for_initialization
2870 (NULL_TREE, type, val, flags,
2871 "argument passing", fndecl, i);
2872 parmval = convert_for_arg_passing (type, parmval);
2875 if (parmval == error_mark_node)
2878 argarray[i] = parmval;
2882 if (fndecl && DECL_BUILT_IN (fndecl)
2883 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2884 /* Don't do ellipsis conversion for __built_in_constant_p
2885 as this will result in spurious warnings for non-POD
2887 val = require_complete_type (val);
2889 val = convert_arg_to_ellipsis (val);
2895 typetail = TREE_CHAIN (typetail);
2898 if (typetail != 0 && typetail != void_list_node)
2900 /* See if there are default arguments that can be used. */
2901 if (TREE_PURPOSE (typetail)
2902 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2904 for (; typetail != void_list_node; ++i)
2907 = convert_default_arg (TREE_VALUE (typetail),
2908 TREE_PURPOSE (typetail),
2911 if (parmval == error_mark_node)
2914 argarray[i] = parmval;
2915 typetail = TREE_CHAIN (typetail);
2916 /* ends with `...'. */
2917 if (typetail == NULL_TREE)
2925 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2926 error ("at this point in file");
2929 error ("too few arguments to function");
2934 gcc_assert (i <= nargs);
2938 /* Build a binary-operation expression, after performing default
2939 conversions on the operands. CODE is the kind of expression to
2940 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2941 are the tree codes which correspond to ARG1 and ARG2 when issuing
2942 warnings about possibly misplaced parentheses. They may differ
2943 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2944 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2945 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2946 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2947 ARG2_CODE as ERROR_MARK. */
2950 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2951 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2960 if (processing_template_decl)
2962 if (type_dependent_expression_p (arg1)
2963 || type_dependent_expression_p (arg2))
2964 return build_min_nt (code, arg1, arg2);
2965 arg1 = build_non_dependent_expr (arg1);
2966 arg2 = build_non_dependent_expr (arg2);
2969 if (code == DOTSTAR_EXPR)
2970 expr = build_m_component_ref (arg1, arg2);
2972 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2975 /* Check for cases such as x+y<<z which users are likely to
2976 misinterpret. But don't warn about obj << x + y, since that is a
2977 common idiom for I/O. */
2978 if (warn_parentheses
2979 && !processing_template_decl
2980 && !error_operand_p (arg1)
2981 && !error_operand_p (arg2)
2982 && (code != LSHIFT_EXPR
2983 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2984 warn_about_parentheses (code, arg1_code, arg2_code);
2986 if (processing_template_decl && expr != error_mark_node)
2987 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2992 /* Build a binary-operation expression without default conversions.
2993 CODE is the kind of expression to build.
2994 This function differs from `build' in several ways:
2995 the data type of the result is computed and recorded in it,
2996 warnings are generated if arg data types are invalid,
2997 special handling for addition and subtraction of pointers is known,
2998 and some optimization is done (operations on narrow ints
2999 are done in the narrower type when that gives the same result).
3000 Constant folding is also done before the result is returned.
3002 Note that the operands will never have enumeral types
3003 because either they have just had the default conversions performed
3004 or they have both just been converted to some other type in which
3005 the arithmetic is to be done.
3007 C++: must do special pointer arithmetic when implementing
3008 multiple inheritance, and deal with pointer to member functions. */
3011 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3012 int convert_p ATTRIBUTE_UNUSED)
3015 enum tree_code code0, code1;
3017 const char *invalid_op_diag;
3019 /* Expression code to give to the expression when it is built.
3020 Normally this is CODE, which is what the caller asked for,
3021 but in some special cases we change it. */
3022 enum tree_code resultcode = code;
3024 /* Data type in which the computation is to be performed.
3025 In the simplest cases this is the common type of the arguments. */
3026 tree result_type = NULL;
3028 /* Nonzero means operands have already been type-converted
3029 in whatever way is necessary.
3030 Zero means they need to be converted to RESULT_TYPE. */
3033 /* Nonzero means create the expression with this type, rather than
3035 tree build_type = 0;
3037 /* Nonzero means after finally constructing the expression
3038 convert it to this type. */
3039 tree final_type = 0;
3043 /* Nonzero if this is an operation like MIN or MAX which can
3044 safely be computed in short if both args are promoted shorts.
3045 Also implies COMMON.
3046 -1 indicates a bitwise operation; this makes a difference
3047 in the exact conditions for when it is safe to do the operation
3048 in a narrower mode. */
3051 /* Nonzero if this is a comparison operation;
3052 if both args are promoted shorts, compare the original shorts.
3053 Also implies COMMON. */
3054 int short_compare = 0;
3056 /* Nonzero if this is a right-shift operation, which can be computed on the
3057 original short and then promoted if the operand is a promoted short. */
3058 int short_shift = 0;
3060 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3063 /* True if both operands have arithmetic type. */
3064 bool arithmetic_types_p;
3066 /* Apply default conversions. */
3070 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3071 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3072 || code == TRUTH_XOR_EXPR)
3074 if (!really_overloaded_fn (op0))
3075 op0 = decay_conversion (op0);
3076 if (!really_overloaded_fn (op1))
3077 op1 = decay_conversion (op1);
3081 if (!really_overloaded_fn (op0))
3082 op0 = default_conversion (op0);
3083 if (!really_overloaded_fn (op1))
3084 op1 = default_conversion (op1);
3087 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3088 STRIP_TYPE_NOPS (op0);
3089 STRIP_TYPE_NOPS (op1);
3091 /* DTRT if one side is an overloaded function, but complain about it. */
3092 if (type_unknown_p (op0))
3094 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3095 if (t != error_mark_node)
3097 pedwarn ("assuming cast to type %qT from overloaded function",
3102 if (type_unknown_p (op1))
3104 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3105 if (t != error_mark_node)
3107 pedwarn ("assuming cast to type %qT from overloaded function",
3113 type0 = TREE_TYPE (op0);
3114 type1 = TREE_TYPE (op1);
3116 /* The expression codes of the data types of the arguments tell us
3117 whether the arguments are integers, floating, pointers, etc. */
3118 code0 = TREE_CODE (type0);
3119 code1 = TREE_CODE (type1);
3121 /* If an error was already reported for one of the arguments,
3122 avoid reporting another error. */
3124 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3125 return error_mark_node;
3127 if ((invalid_op_diag
3128 = targetm.invalid_binary_op (code, type0, type1)))
3130 error (invalid_op_diag);
3131 return error_mark_node;
3137 /* Subtraction of two similar pointers.
3138 We must subtract them as integers, then divide by object size. */
3139 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3140 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3142 return pointer_diff (op0, op1, common_type (type0, type1));
3143 /* In all other cases except pointer - int, the usual arithmetic
3145 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3150 /* The pointer - int case is just like pointer + int; fall
3153 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3154 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3158 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3159 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3160 if (processing_template_decl)
3162 result_type = TREE_TYPE (ptr_operand);
3165 return cp_pointer_int_sum (code,
3176 case TRUNC_DIV_EXPR:
3178 case FLOOR_DIV_EXPR:
3179 case ROUND_DIV_EXPR:
3180 case EXACT_DIV_EXPR:
3181 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3182 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3183 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3184 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3186 enum tree_code tcode0 = code0, tcode1 = code1;
3188 warn_for_div_by_zero (op1);
3190 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3191 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3192 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3193 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3195 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3196 resultcode = RDIV_EXPR;
3198 /* When dividing two signed integers, we have to promote to int.
3199 unless we divide by a constant != -1. Note that default
3200 conversion will have been performed on the operands at this
3201 point, so we have to dig out the original type to find out if
3203 shorten = ((TREE_CODE (op0) == NOP_EXPR
3204 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3205 || (TREE_CODE (op1) == INTEGER_CST
3206 && ! integer_all_onesp (op1)));
3215 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3216 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3220 case TRUNC_MOD_EXPR:
3221 case FLOOR_MOD_EXPR:
3222 warn_for_div_by_zero (op1);
3224 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3226 /* Although it would be tempting to shorten always here, that loses
3227 on some targets, since the modulo instruction is undefined if the
3228 quotient can't be represented in the computation mode. We shorten
3229 only if unsigned or if dividing by something we know != -1. */
3230 shorten = ((TREE_CODE (op0) == NOP_EXPR
3231 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3232 || (TREE_CODE (op1) == INTEGER_CST
3233 && ! integer_all_onesp (op1)));
3238 case TRUTH_ANDIF_EXPR:
3239 case TRUTH_ORIF_EXPR:
3240 case TRUTH_AND_EXPR:
3242 result_type = boolean_type_node;
3245 /* Shift operations: result has same type as first operand;
3246 always convert second operand to int.
3247 Also set SHORT_SHIFT if shifting rightward. */
3250 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3252 result_type = type0;
3253 if (TREE_CODE (op1) == INTEGER_CST)
3255 if (tree_int_cst_lt (op1, integer_zero_node))
3256 warning (0, "right shift count is negative");
3259 if (! integer_zerop (op1))
3261 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3262 warning (0, "right shift count >= width of type");
3265 /* Convert the shift-count to an integer, regardless of
3266 size of value being shifted. */
3267 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3268 op1 = cp_convert (integer_type_node, op1);
3269 /* Avoid converting op1 to result_type later. */
3275 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3277 result_type = type0;
3278 if (TREE_CODE (op1) == INTEGER_CST)
3280 if (tree_int_cst_lt (op1, integer_zero_node))
3281 warning (0, "left shift count is negative");
3282 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3283 warning (0, "left shift count >= width of type");
3285 /* Convert the shift-count to an integer, regardless of
3286 size of value being shifted. */
3287 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3288 op1 = cp_convert (integer_type_node, op1);
3289 /* Avoid converting op1 to result_type later. */
3296 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3298 result_type = type0;
3299 if (TREE_CODE (op1) == INTEGER_CST)
3301 if (tree_int_cst_lt (op1, integer_zero_node))
3302 warning (0, (code == LROTATE_EXPR)
3303 ? G_("left rotate count is negative")
3304 : G_("right rotate count is negative"));
3305 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3306 warning (0, (code == LROTATE_EXPR)
3307 ? G_("left rotate count >= width of type")
3308 : G_("right rotate count >= width of type"));
3310 /* Convert the shift-count to an integer, regardless of
3311 size of value being shifted. */
3312 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3313 op1 = cp_convert (integer_type_node, op1);
3319 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3320 warning (OPT_Wfloat_equal,
3321 "comparing floating point with == or != is unsafe");
3322 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3323 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3324 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3326 build_type = boolean_type_node;
3327 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3328 || code0 == COMPLEX_TYPE)
3329 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3330 || code1 == COMPLEX_TYPE))
3332 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3333 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3334 result_type = composite_pointer_type (type0, type1, op0, op1,
3336 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3337 && null_ptr_cst_p (op1))
3339 if (TREE_CODE (op0) == ADDR_EXPR
3340 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3341 warning (OPT_Waddress, "the address of %qD will never be NULL",
3342 TREE_OPERAND (op0, 0));
3343 result_type = type0;
3345 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3346 && null_ptr_cst_p (op0))
3348 if (TREE_CODE (op1) == ADDR_EXPR
3349 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3350 warning (OPT_Waddress, "the address of %qD will never be NULL",
3351 TREE_OPERAND (op1, 0));
3352 result_type = type1;
3354 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3356 result_type = type0;
3357 error ("ISO C++ forbids comparison between pointer and integer");
3359 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3361 result_type = type1;
3362 error ("ISO C++ forbids comparison between pointer and integer");
3364 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3366 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3367 == ptrmemfunc_vbit_in_delta)
3369 tree pfn0 = pfn_from_ptrmemfunc (op0);
3370 tree delta0 = build_ptrmemfunc_access_expr (op0,
3372 tree e1 = cp_build_binary_op (EQ_EXPR,
3374 fold_convert (TREE_TYPE (pfn0),
3375 integer_zero_node));
3376 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3379 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3380 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3381 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3385 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3386 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3388 result_type = TREE_TYPE (op0);
3390 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3391 return cp_build_binary_op (code, op1, op0);
3392 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3393 && same_type_p (type0, type1))
3395 /* E will be the final comparison. */
3397 /* E1 and E2 are for scratch. */
3405 if (TREE_SIDE_EFFECTS (op0))
3406 op0 = save_expr (op0);
3407 if (TREE_SIDE_EFFECTS (op1))
3408 op1 = save_expr (op1);
3410 pfn0 = pfn_from_ptrmemfunc (op0);
3411 pfn1 = pfn_from_ptrmemfunc (op1);
3412 delta0 = build_ptrmemfunc_access_expr (op0,
3414 delta1 = build_ptrmemfunc_access_expr (op1,
3416 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3417 == ptrmemfunc_vbit_in_delta)
3422 && ((op0.delta == op1.delta)
3423 || (!op0.pfn && op0.delta & 1 == 0
3424 && op1.delta & 1 == 0))
3426 The reason for the `!op0.pfn' bit is that a NULL
3427 pointer-to-member is any member with a zero PFN and
3428 LSB of the DELTA field is 0. */
3430 e1 = cp_build_binary_op (BIT_AND_EXPR,
3433 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3434 e2 = cp_build_binary_op (BIT_AND_EXPR,
3437 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3438 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3439 e2 = cp_build_binary_op (EQ_EXPR,
3441 fold_convert (TREE_TYPE (pfn0),
3442 integer_zero_node));
3443 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3444 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3445 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3452 && (!op0.pfn || op0.delta == op1.delta))
3454 The reason for the `!op0.pfn' bit is that a NULL
3455 pointer-to-member is any member with a zero PFN; the
3456 DELTA field is unspecified. */
3458 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3459 e2 = cp_build_binary_op (EQ_EXPR,
3461 fold_convert (TREE_TYPE (pfn0),
3462 integer_zero_node));
3463 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3465 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3466 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3467 if (code == EQ_EXPR)
3469 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3473 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3474 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3476 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3477 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3485 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3486 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3488 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3489 result_type = composite_pointer_type (type0, type1, op0, op1,
3497 if (TREE_CODE (orig_op0) == STRING_CST
3498 || TREE_CODE (orig_op1) == STRING_CST)
3499 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3501 build_type = boolean_type_node;
3502 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3503 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3505 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3506 result_type = composite_pointer_type (type0, type1, op0, op1,
3508 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3509 && integer_zerop (op1))
3510 result_type = type0;
3511 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3512 && integer_zerop (op0))
3513 result_type = type1;
3514 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3516 result_type = type0;
3517 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3519 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3521 result_type = type1;
3522 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3526 case UNORDERED_EXPR:
3533 build_type = integer_type_node;
3534 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3536 error ("unordered comparison on non-floating point argument");
3537 return error_mark_node;
3546 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3547 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3548 || code1 == COMPLEX_TYPE)))
3549 arithmetic_types_p = 1;
3552 arithmetic_types_p = 0;
3553 /* Vector arithmetic is only allowed when both sides are vectors. */
3554 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3556 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3557 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3560 binary_op_error (code, type0, type1);
3561 return error_mark_node;
3563 arithmetic_types_p = 1;
3566 /* Determine the RESULT_TYPE, if it is not already known. */
3568 && arithmetic_types_p
3569 && (shorten || common || short_compare))
3570 result_type = common_type (type0, type1);
3574 error ("invalid operands of types %qT and %qT to binary %qO",
3575 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3576 return error_mark_node;
3579 /* If we're in a template, the only thing we need to know is the
3581 if (processing_template_decl)
3583 /* Since the middle-end checks the type when doing a build2, we
3584 need to build the tree in pieces. This built tree will never
3585 get out of the front-end as we replace it when instantiating
3587 tree tmp = build2 (resultcode,
3588 build_type ? build_type : result_type,
3590 TREE_OPERAND (tmp, 0) = op0;
3594 if (arithmetic_types_p)
3596 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3598 /* For certain operations (which identify themselves by shorten != 0)
3599 if both args were extended from the same smaller type,
3600 do the arithmetic in that type and then extend.
3602 shorten !=0 and !=1 indicates a bitwise operation.
3603 For them, this optimization is safe only if
3604 both args are zero-extended or both are sign-extended.
3605 Otherwise, we might change the result.
3606 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3607 but calculated in (unsigned short) it would be (unsigned short)-1. */
3609 if (shorten && none_complex)
3611 int unsigned0, unsigned1;
3612 tree arg0 = get_narrower (op0, &unsigned0);
3613 tree arg1 = get_narrower (op1, &unsigned1);
3614 /* UNS is 1 if the operation to be done is an unsigned one. */
3615 int uns = TYPE_UNSIGNED (result_type);
3618 final_type = result_type;
3620 /* Handle the case that OP0 does not *contain* a conversion
3621 but it *requires* conversion to FINAL_TYPE. */
3623 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3624 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3625 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3626 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3628 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3630 /* For bitwise operations, signedness of nominal type
3631 does not matter. Consider only how operands were extended. */
3635 /* Note that in all three cases below we refrain from optimizing
3636 an unsigned operation on sign-extended args.
3637 That would not be valid. */
3639 /* Both args variable: if both extended in same way
3640 from same width, do it in that width.
3641 Do it unsigned if args were zero-extended. */
3642 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3643 < TYPE_PRECISION (result_type))
3644 && (TYPE_PRECISION (TREE_TYPE (arg1))
3645 == TYPE_PRECISION (TREE_TYPE (arg0)))
3646 && unsigned0 == unsigned1
3647 && (unsigned0 || !uns))
3648 result_type = c_common_signed_or_unsigned_type
3649 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3650 else if (TREE_CODE (arg0) == INTEGER_CST
3651 && (unsigned1 || !uns)
3652 && (TYPE_PRECISION (TREE_TYPE (arg1))
3653 < TYPE_PRECISION (result_type))
3654 && (type = c_common_signed_or_unsigned_type
3655 (unsigned1, TREE_TYPE (arg1)),
3656 int_fits_type_p (arg0, type)))
3658 else if (TREE_CODE (arg1) == INTEGER_CST
3659 && (unsigned0 || !uns)
3660 && (TYPE_PRECISION (TREE_TYPE (arg0))
3661 < TYPE_PRECISION (result_type))
3662 && (type = c_common_signed_or_unsigned_type
3663 (unsigned0, TREE_TYPE (arg0)),
3664 int_fits_type_p (arg1, type)))
3668 /* Shifts can be shortened if shifting right. */
3673 tree arg0 = get_narrower (op0, &unsigned_arg);
3675 final_type = result_type;
3677 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3678 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3680 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3681 /* We can shorten only if the shift count is less than the
3682 number of bits in the smaller type size. */
3683 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3684 /* If arg is sign-extended and then unsigned-shifted,
3685 we can simulate this with a signed shift in arg's type
3686 only if the extended result is at least twice as wide
3687 as the arg. Otherwise, the shift could use up all the
3688 ones made by sign-extension and bring in zeros.
3689 We can't optimize that case at all, but in most machines
3690 it never happens because available widths are 2**N. */
3691 && (!TYPE_UNSIGNED (final_type)
3693 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3694 <= TYPE_PRECISION (result_type))))
3696 /* Do an unsigned shift if the operand was zero-extended. */
3698 = c_common_signed_or_unsigned_type (unsigned_arg,
3700 /* Convert value-to-be-shifted to that type. */
3701 if (TREE_TYPE (op0) != result_type)
3702 op0 = cp_convert (result_type, op0);
3707 /* Comparison operations are shortened too but differently.
3708 They identify themselves by setting short_compare = 1. */
3712 /* Don't write &op0, etc., because that would prevent op0
3713 from being kept in a register.
3714 Instead, make copies of the our local variables and
3715 pass the copies by reference, then copy them back afterward. */
3716 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3717 enum tree_code xresultcode = resultcode;
3719 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3721 return cp_convert (boolean_type_node, val);
3722 op0 = xop0, op1 = xop1;
3724 resultcode = xresultcode;
3727 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3728 && warn_sign_compare
3729 /* Do not warn until the template is instantiated; we cannot
3730 bound the ranges of the arguments until that point. */
3731 && !processing_template_decl)
3733 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3734 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3736 int unsignedp0, unsignedp1;
3737 tree primop0 = get_narrower (op0, &unsignedp0);
3738 tree primop1 = get_narrower (op1, &unsignedp1);
3740 /* Check for comparison of different enum types. */
3741 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3742 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3743 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3744 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3746 warning (0, "comparison between types %q#T and %q#T",
3747 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3750 /* Give warnings for comparisons between signed and unsigned
3751 quantities that may fail. */
3752 /* Do the checking based on the original operand trees, so that
3753 casts will be considered, but default promotions won't be. */
3755 /* Do not warn if the comparison is being done in a signed type,
3756 since the signed type will only be chosen if it can represent
3757 all the values of the unsigned type. */
3758 if (!TYPE_UNSIGNED (result_type))
3760 /* Do not warn if both operands are unsigned. */
3761 else if (op0_signed == op1_signed)
3763 /* Do not warn if the signed quantity is an unsuffixed
3764 integer literal (or some static constant expression
3765 involving such literals or a conditional expression
3766 involving such literals) and it is non-negative. */
3767 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3768 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3770 /* Do not warn if the comparison is an equality operation,
3771 the unsigned quantity is an integral constant and it does
3772 not use the most significant bit of result_type. */
3773 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3774 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3775 && int_fits_type_p (orig_op1, c_common_signed_type
3777 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3778 && int_fits_type_p (orig_op0, c_common_signed_type
3782 warning (0, "comparison between signed and unsigned integer expressions");
3784 /* Warn if two unsigned values are being compared in a size
3785 larger than their original size, and one (and only one) is the
3786 result of a `~' operator. This comparison will always fail.
3788 Also warn if one operand is a constant, and the constant does not
3789 have all bits set that are set in the ~ operand when it is
3792 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3793 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3795 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3796 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3797 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3798 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3800 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3803 HOST_WIDE_INT constant, mask;
3807 if (host_integerp (primop0, 0))
3810 unsignedp = unsignedp1;
3811 constant = tree_low_cst (primop0, 0);
3816 unsignedp = unsignedp0;
3817 constant = tree_low_cst (primop1, 0);
3820 bits = TYPE_PRECISION (TREE_TYPE (primop));
3821 if (bits < TYPE_PRECISION (result_type)
3822 && bits < HOST_BITS_PER_LONG && unsignedp)
3824 mask = (~ (HOST_WIDE_INT) 0) << bits;
3825 if ((mask & constant) != mask)
3826 warning (0, "comparison of promoted ~unsigned with constant");
3829 else if (unsignedp0 && unsignedp1
3830 && (TYPE_PRECISION (TREE_TYPE (primop0))
3831 < TYPE_PRECISION (result_type))
3832 && (TYPE_PRECISION (TREE_TYPE (primop1))
3833 < TYPE_PRECISION (result_type)))
3834 warning (0, "comparison of promoted ~unsigned with unsigned");
3839 /* Issue warnings about peculiar, but valid, uses of NULL. */
3840 if ((orig_op0 == null_node || orig_op1 == null_node)
3841 /* It's reasonable to use pointer values as operands of &&
3842 and ||, so NULL is no exception. */
3843 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3844 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3845 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3846 && code != EQ_EXPR && code != NE_EXPR)
3847 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3848 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3849 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3850 /* Some sort of arithmetic operation involving NULL was
3851 performed. Note that pointer-difference and pointer-addition
3852 have already been handled above, and so we don't end up here in
3854 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3857 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3858 Then the expression will be built.
3859 It will be given type FINAL_TYPE if that is nonzero;
3860 otherwise, it will be given type RESULT_TYPE. */
3863 if (TREE_TYPE (op0) != result_type)
3864 op0 = cp_convert_and_check (result_type, op0);
3865 if (TREE_TYPE (op1) != result_type)
3866 op1 = cp_convert_and_check (result_type, op1);
3868 if (op0 == error_mark_node || op1 == error_mark_node)
3869 return error_mark_node;
3872 if (build_type == NULL_TREE)
3873 build_type = result_type;
3875 result = build2 (resultcode, build_type, op0, op1);
3876 result = fold_if_not_in_template (result);
3877 if (final_type != 0)
3878 result = cp_convert (final_type, result);
3880 if (TREE_OVERFLOW_P (result)
3881 && !TREE_OVERFLOW_P (op0)
3882 && !TREE_OVERFLOW_P (op1))
3883 overflow_warning (result);
3888 /* Return a tree for the sum or difference (RESULTCODE says which)
3889 of pointer PTROP and integer INTOP. */
3892 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3894 tree res_type = TREE_TYPE (ptrop);
3896 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3897 in certain circumstance (when it's valid to do so). So we need
3898 to make sure it's complete. We don't need to check here, if we
3899 can actually complete it at all, as those checks will be done in
3900 pointer_int_sum() anyway. */
3901 complete_type (TREE_TYPE (res_type));
3903 return pointer_int_sum (resultcode, ptrop,
3904 fold_if_not_in_template (intop));
3907 /* Return a tree for the difference of pointers OP0 and OP1.
3908 The resulting tree has type int. */
3911 pointer_diff (tree op0, tree op1, tree ptrtype)
3914 tree restype = ptrdiff_type_node;
3915 tree target_type = TREE_TYPE (ptrtype);
3917 if (!complete_type_or_else (target_type, NULL_TREE))
3918 return error_mark_node;
3920 if (pedantic || warn_pointer_arith)
3922 if (TREE_CODE (target_type) == VOID_TYPE)
3923 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3924 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3925 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3926 if (TREE_CODE (target_type) == METHOD_TYPE)
3927 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3930 /* First do the subtraction as integers;
3931 then drop through to build the divide operator. */
3933 op0 = cp_build_binary_op (MINUS_EXPR,
3934 cp_convert (restype, op0),
3935 cp_convert (restype, op1));
3937 /* This generates an error if op1 is a pointer to an incomplete type. */
3938 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3939 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3941 op1 = (TYPE_PTROB_P (ptrtype)
3942 ? size_in_bytes (target_type)
3943 : integer_one_node);
3945 /* Do the division. */
3947 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3948 return fold_if_not_in_template (result);
3951 /* Construct and perhaps optimize a tree representation
3952 for a unary operation. CODE, a tree_code, specifies the operation
3953 and XARG is the operand. */
3956 build_x_unary_op (enum tree_code code, tree xarg)
3958 tree orig_expr = xarg;
3962 if (processing_template_decl)
3964 if (type_dependent_expression_p (xarg))
3965 return build_min_nt (code, xarg, NULL_TREE);
3967 xarg = build_non_dependent_expr (xarg);
3972 /* [expr.unary.op] says:
3974 The address of an object of incomplete type can be taken.
3976 (And is just the ordinary address operator, not an overloaded
3977 "operator &".) However, if the type is a template
3978 specialization, we must complete the type at this point so that
3979 an overloaded "operator &" will be available if required. */
3980 if (code == ADDR_EXPR
3981 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3982 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3983 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3984 || (TREE_CODE (xarg) == OFFSET_REF)))
3985 /* Don't look for a function. */;
3987 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3988 /*overloaded_p=*/NULL);
3989 if (!exp && code == ADDR_EXPR)
3991 /* A pointer to member-function can be formed only by saying
3993 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3994 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3996 if (TREE_CODE (xarg) != OFFSET_REF
3997 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3999 error ("invalid use of %qE to form a pointer-to-member-function",
4001 if (TREE_CODE (xarg) != OFFSET_REF)
4002 inform (" a qualified-id is required");
4003 return error_mark_node;
4007 error ("parentheses around %qE cannot be used to form a"
4008 " pointer-to-member-function",
4010 PTRMEM_OK_P (xarg) = 1;
4014 if (TREE_CODE (xarg) == OFFSET_REF)
4016 ptrmem = PTRMEM_OK_P (xarg);
4018 if (!ptrmem && !flag_ms_extensions
4019 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4021 /* A single non-static member, make sure we don't allow a
4022 pointer-to-member. */
4023 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4024 TREE_OPERAND (xarg, 0),
4025 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4026 PTRMEM_OK_P (xarg) = ptrmem;
4029 else if (TREE_CODE (xarg) == TARGET_EXPR)
4030 warning (0, "taking address of temporary");
4031 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4034 if (processing_template_decl && exp != error_mark_node)
4035 exp = build_min_non_dep (code, exp, orig_expr,
4036 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4037 if (TREE_CODE (exp) == ADDR_EXPR)
4038 PTRMEM_OK_P (exp) = ptrmem;
4042 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4043 constants, where a null value is represented by an INTEGER_CST of
4047 cp_truthvalue_conversion (tree expr)
4049 tree type = TREE_TYPE (expr);
4050 if (TYPE_PTRMEM_P (type))
4051 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4053 return c_common_truthvalue_conversion (expr);
4056 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4059 condition_conversion (tree expr)
4062 if (processing_template_decl)
4064 t = perform_implicit_conversion (boolean_type_node, expr);
4065 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4069 /* Return an ADDR_EXPR giving the address of T. This function
4070 attempts no optimizations or simplifications; it is a low-level
4074 build_address (tree t)
4078 if (error_operand_p (t) || !cxx_mark_addressable (t))
4079 return error_mark_node;
4081 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4086 /* Return a NOP_EXPR converting EXPR to TYPE. */
4089 build_nop (tree type, tree expr)
4091 if (type == error_mark_node || error_operand_p (expr))
4093 return build1 (NOP_EXPR, type, expr);
4096 /* C++: Must handle pointers to members.
4098 Perhaps type instantiation should be extended to handle conversion
4099 from aggregates to types we don't yet know we want? (Or are those
4100 cases typically errors which should be reported?)
4102 NOCONVERT nonzero suppresses the default promotions
4103 (such as from short to int). */
4106 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4108 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4111 const char *errstring = NULL;
4113 const char *invalid_op_diag;
4115 if (arg == error_mark_node)
4116 return error_mark_node;
4118 if ((invalid_op_diag
4119 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4124 error (invalid_op_diag);
4125 return error_mark_node;
4130 case UNARY_PLUS_EXPR:
4133 int flags = WANT_ARITH | WANT_ENUM;
4134 /* Unary plus (but not unary minus) is allowed on pointers. */
4135 if (code == UNARY_PLUS_EXPR)
4136 flags |= WANT_POINTER;
4137 arg = build_expr_type_conversion (flags, arg, true);
4139 errstring = (code == NEGATE_EXPR
4140 ? "wrong type argument to unary minus"
4141 : "wrong type argument to unary plus");
4144 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4145 arg = perform_integral_promotions (arg);
4147 /* Make sure the result is not an lvalue: a unary plus or minus
4148 expression is always a rvalue. */
4155 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4159 arg = default_conversion (arg);
4161 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4164 errstring = "wrong type argument to bit-complement";
4165 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4166 arg = perform_integral_promotions (arg);
4170 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4171 errstring = "wrong type argument to abs";
4172 else if (!noconvert)
4173 arg = default_conversion (arg);
4177 /* Conjugating a real value is a no-op, but allow it anyway. */
4178 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4179 errstring = "wrong type argument to conjugation";
4180 else if (!noconvert)
4181 arg = default_conversion (arg);
4184 case TRUTH_NOT_EXPR:
4185 arg = perform_implicit_conversion (boolean_type_node, arg);
4186 val = invert_truthvalue (arg);
4187 if (arg != error_mark_node)
4189 errstring = "in argument to unary !";
4196 if (TREE_CODE (arg) == COMPLEX_CST)
4197 return TREE_REALPART (arg);
4198 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4200 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4201 return fold_if_not_in_template (arg);
4207 if (TREE_CODE (arg) == COMPLEX_CST)
4208 return TREE_IMAGPART (arg);
4209 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4211 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4212 return fold_if_not_in_template (arg);
4215 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4217 case PREINCREMENT_EXPR:
4218 case POSTINCREMENT_EXPR:
4219 case PREDECREMENT_EXPR:
4220 case POSTDECREMENT_EXPR:
4221 /* Handle complex lvalues (when permitted)
4222 by reduction to simpler cases. */
4224 val = unary_complex_lvalue (code, arg);
4228 /* Increment or decrement the real part of the value,
4229 and don't change the imaginary part. */
4230 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4234 arg = stabilize_reference (arg);
4235 real = build_unary_op (REALPART_EXPR, arg, 1);
4236 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4237 real = build_unary_op (code, real, 1);
4238 if (real == error_mark_node || imag == error_mark_node)
4239 return error_mark_node;
4240 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4244 /* Report invalid types. */
4246 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4249 if (code == PREINCREMENT_EXPR)
4250 errstring ="no pre-increment operator for type";
4251 else if (code == POSTINCREMENT_EXPR)
4252 errstring ="no post-increment operator for type";
4253 else if (code == PREDECREMENT_EXPR)
4254 errstring ="no pre-decrement operator for type";
4256 errstring ="no post-decrement operator for type";
4260 /* Report something read-only. */
4262 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4263 || TREE_READONLY (arg))
4264 readonly_error (arg, ((code == PREINCREMENT_EXPR
4265 || code == POSTINCREMENT_EXPR)
4266 ? "increment" : "decrement"));
4271 tree result_type = TREE_TYPE (arg);
4273 declared_type = unlowered_expr_type (arg);
4275 arg = get_unwidened (arg, 0);
4276 argtype = TREE_TYPE (arg);
4278 /* ARM $5.2.5 last annotation says this should be forbidden. */
4279 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4280 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4281 ? G_("ISO C++ forbids incrementing an enum")
4282 : G_("ISO C++ forbids decrementing an enum"));
4284 /* Compute the increment. */
4286 if (TREE_CODE (argtype) == POINTER_TYPE)
4288 tree type = complete_type (TREE_TYPE (argtype));
4290 if (!COMPLETE_OR_VOID_TYPE_P (type))
4291 error (((code == PREINCREMENT_EXPR
4292 || code == POSTINCREMENT_EXPR))
4293 ? G_("cannot increment a pointer to incomplete type %qT")
4294 : G_("cannot decrement a pointer to incomplete type %qT"),
4295 TREE_TYPE (argtype));
4296 else if ((pedantic || warn_pointer_arith)
4297 && !TYPE_PTROB_P (argtype))
4298 pedwarn ((code == PREINCREMENT_EXPR
4299 || code == POSTINCREMENT_EXPR)
4300 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4301 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4303 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4306 inc = integer_one_node;
4308 inc = cp_convert (argtype, inc);
4310 /* Complain about anything else that is not a true lvalue. */
4311 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4312 || code == POSTINCREMENT_EXPR)
4313 ? lv_increment : lv_decrement)))
4314 return error_mark_node;
4316 /* Forbid using -- on `bool'. */
4317 if (same_type_p (declared_type, boolean_type_node))
4319 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4321 error ("invalid use of %<--%> on bool variable %qD", arg);
4322 return error_mark_node;
4324 val = boolean_increment (code, arg);
4327 val = build2 (code, TREE_TYPE (arg), arg, inc);
4329 TREE_SIDE_EFFECTS (val) = 1;
4330 return cp_convert (result_type, val);
4334 /* Note that this operation never does default_conversion
4335 regardless of NOCONVERT. */
4337 argtype = lvalue_type (arg);
4339 if (TREE_CODE (arg) == OFFSET_REF)
4342 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4344 tree type = build_pointer_type (TREE_TYPE (argtype));
4345 arg = build1 (CONVERT_EXPR, type, arg);
4348 else if (pedantic && DECL_MAIN_P (arg))
4350 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4352 /* Let &* cancel out to simplify resulting code. */
4353 if (TREE_CODE (arg) == INDIRECT_REF)
4355 /* We don't need to have `current_class_ptr' wrapped in a
4356 NON_LVALUE_EXPR node. */
4357 if (arg == current_class_ref)
4358 return current_class_ptr;
4360 arg = TREE_OPERAND (arg, 0);
4361 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4363 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4364 arg = build1 (CONVERT_EXPR, type, arg);
4367 /* Don't let this be an lvalue. */
4372 /* Uninstantiated types are all functions. Taking the
4373 address of a function is a no-op, so just return the
4376 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4377 || !IDENTIFIER_OPNAME_P (arg));
4379 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4380 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4382 /* They're trying to take the address of a unique non-static
4383 member function. This is ill-formed (except in MS-land),
4384 but let's try to DTRT.
4385 Note: We only handle unique functions here because we don't
4386 want to complain if there's a static overload; non-unique
4387 cases will be handled by instantiate_type. But we need to
4388 handle this case here to allow casts on the resulting PMF.
4389 We could defer this in non-MS mode, but it's easier to give
4390 a useful error here. */
4392 /* Inside constant member functions, the `this' pointer
4393 contains an extra const qualifier. TYPE_MAIN_VARIANT
4394 is used here to remove this const from the diagnostics
4395 and the created OFFSET_REF. */
4396 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4397 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4400 if (! flag_ms_extensions)
4402 tree name = DECL_NAME (fn);
4403 if (current_class_type
4404 && TREE_OPERAND (arg, 0) == current_class_ref)
4405 /* An expression like &memfn. */
4406 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4407 " or parenthesized non-static member function to form"
4408 " a pointer to member function. Say %<&%T::%D%>",
4411 pedwarn ("ISO C++ forbids taking the address of a bound member"
4412 " function to form a pointer to member function."
4416 arg = build_offset_ref (base, fn, /*address_p=*/true);
4420 if (type_unknown_p (arg))
4421 return build1 (ADDR_EXPR, unknown_type_node, arg);
4423 /* Handle complex lvalues (when permitted)
4424 by reduction to simpler cases. */
4425 val = unary_complex_lvalue (code, arg);
4429 switch (TREE_CODE (arg))
4434 case FIX_TRUNC_EXPR:
4435 if (! lvalue_p (arg) && pedantic)
4436 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4440 arg = BASELINK_FUNCTIONS (arg);
4444 arg = OVL_CURRENT (arg);
4448 /* Turn a reference to a non-static data member into a
4449 pointer-to-member. */
4454 if (!PTRMEM_OK_P (arg))
4455 return build_unary_op (code, arg, 0);
4457 t = TREE_OPERAND (arg, 1);
4458 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4460 error ("cannot create pointer to reference member %qD", t);
4461 return error_mark_node;
4464 type = build_ptrmem_type (context_for_name_lookup (t),
4466 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4474 /* Anything not already handled and not a true memory reference
4476 if (TREE_CODE (argtype) != FUNCTION_TYPE
4477 && TREE_CODE (argtype) != METHOD_TYPE
4478 && TREE_CODE (arg) != OFFSET_REF
4479 && !lvalue_or_else (arg, lv_addressof))
4480 return error_mark_node;
4482 if (argtype != error_mark_node)
4483 argtype = build_pointer_type (argtype);
4485 /* In a template, we are processing a non-dependent expression
4486 so we can just form an ADDR_EXPR with the correct type. */
4487 if (processing_template_decl)
4489 val = build_address (arg);
4490 if (TREE_CODE (arg) == OFFSET_REF)
4491 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4495 if (TREE_CODE (arg) != COMPONENT_REF)
4497 val = build_address (arg);
4498 if (TREE_CODE (arg) == OFFSET_REF)
4499 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4501 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4503 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4505 /* We can only get here with a single static member
4507 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4508 && DECL_STATIC_FUNCTION_P (fn));
4510 val = build_address (fn);
4511 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4512 /* Do not lose object's side effects. */
4513 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4514 TREE_OPERAND (arg, 0), val);
4516 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4518 error ("attempt to take address of bit-field structure member %qD",
4519 TREE_OPERAND (arg, 1));
4520 return error_mark_node;
4524 tree object = TREE_OPERAND (arg, 0);
4525 tree field = TREE_OPERAND (arg, 1);
4526 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4527 (TREE_TYPE (object), decl_type_context (field)));
4528 val = build_address (arg);
4531 if (TREE_CODE (argtype) == POINTER_TYPE
4532 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4534 build_ptrmemfunc_type (argtype);
4535 val = build_ptrmemfunc (argtype, val, 0,
4536 /*c_cast_p=*/false);
4548 argtype = TREE_TYPE (arg);
4549 return fold_if_not_in_template (build1 (code, argtype, arg));
4552 error ("%s", errstring);
4553 return error_mark_node;
4556 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4557 for certain kinds of expressions which are not really lvalues
4558 but which we can accept as lvalues.
4560 If ARG is not a kind of expression we can handle, return
4564 unary_complex_lvalue (enum tree_code code, tree arg)
4566 /* Inside a template, making these kinds of adjustments is
4567 pointless; we are only concerned with the type of the
4569 if (processing_template_decl)
4572 /* Handle (a, b) used as an "lvalue". */
4573 if (TREE_CODE (arg) == COMPOUND_EXPR)
4575 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4576 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4577 TREE_OPERAND (arg, 0), real_result);
4580 /* Handle (a ? b : c) used as an "lvalue". */
4581 if (TREE_CODE (arg) == COND_EXPR
4582 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4583 return rationalize_conditional_expr (code, arg);
4585 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4586 if (TREE_CODE (arg) == MODIFY_EXPR
4587 || TREE_CODE (arg) == PREINCREMENT_EXPR
4588 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4590 tree lvalue = TREE_OPERAND (arg, 0);
4591 if (TREE_SIDE_EFFECTS (lvalue))
4593 lvalue = stabilize_reference (lvalue);
4594 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4595 lvalue, TREE_OPERAND (arg, 1));
4597 return unary_complex_lvalue
4598 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4601 if (code != ADDR_EXPR)
4604 /* Handle (a = b) used as an "lvalue" for `&'. */
4605 if (TREE_CODE (arg) == MODIFY_EXPR
4606 || TREE_CODE (arg) == INIT_EXPR)
4608 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4609 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4611 TREE_NO_WARNING (arg) = 1;
4615 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4616 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4617 || TREE_CODE (arg) == OFFSET_REF)
4620 /* We permit compiler to make function calls returning
4621 objects of aggregate type look like lvalues. */
4625 if (TREE_CODE (targ) == SAVE_EXPR)
4626 targ = TREE_OPERAND (targ, 0);
4628 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4630 if (TREE_CODE (arg) == SAVE_EXPR)
4633 targ = build_cplus_new (TREE_TYPE (arg), arg);
4634 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4637 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4638 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4639 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4642 /* Don't let anything else be handled specially. */
4646 /* Mark EXP saying that we need to be able to take the
4647 address of it; it should not be allocated in a register.
4648 Value is true if successful.
4650 C++: we do not allow `current_class_ptr' to be addressable. */
4653 cxx_mark_addressable (tree exp)
4658 switch (TREE_CODE (x))
4665 x = TREE_OPERAND (x, 0);
4669 if (x == current_class_ptr)
4671 error ("cannot take the address of %<this%>, which is an rvalue expression");
4672 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4678 /* Caller should not be trying to mark initialized
4679 constant fields addressable. */
4680 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4681 || DECL_IN_AGGR_P (x) == 0
4683 || DECL_EXTERNAL (x));
4688 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4689 && !DECL_ARTIFICIAL (x))
4691 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4694 ("address of explicit register variable %qD requested", x);
4697 else if (extra_warnings)
4699 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4701 TREE_ADDRESSABLE (x) = 1;
4705 TREE_ADDRESSABLE (x) = 1;
4709 TREE_ADDRESSABLE (x) = 1;
4713 TREE_ADDRESSABLE (x) = 1;
4714 cxx_mark_addressable (TREE_OPERAND (x, 0));
4722 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4725 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4727 tree orig_ifexp = ifexp;
4728 tree orig_op1 = op1;
4729 tree orig_op2 = op2;
4732 if (processing_template_decl)
4734 /* The standard says that the expression is type-dependent if
4735 IFEXP is type-dependent, even though the eventual type of the
4736 expression doesn't dependent on IFEXP. */
4737 if (type_dependent_expression_p (ifexp)
4738 /* As a GNU extension, the middle operand may be omitted. */
4739 || (op1 && type_dependent_expression_p (op1))
4740 || type_dependent_expression_p (op2))
4741 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4742 ifexp = build_non_dependent_expr (ifexp);
4744 op1 = build_non_dependent_expr (op1);
4745 op2 = build_non_dependent_expr (op2);
4748 expr = build_conditional_expr (ifexp, op1, op2);
4749 if (processing_template_decl && expr != error_mark_node)
4750 return build_min_non_dep (COND_EXPR, expr,
4751 orig_ifexp, orig_op1, orig_op2);
4755 /* Given a list of expressions, return a compound expression
4756 that performs them all and returns the value of the last of them. */
4758 tree build_x_compound_expr_from_list (tree list, const char *msg)
4760 tree expr = TREE_VALUE (list);
4762 if (TREE_CHAIN (list))
4765 pedwarn ("%s expression list treated as compound expression", msg);
4767 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4768 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4774 /* Handle overloading of the ',' operator when needed. */
4777 build_x_compound_expr (tree op1, tree op2)
4780 tree orig_op1 = op1;
4781 tree orig_op2 = op2;
4783 if (processing_template_decl)
4785 if (type_dependent_expression_p (op1)
4786 || type_dependent_expression_p (op2))
4787 return build_min_nt (COMPOUND_EXPR, op1, op2);
4788 op1 = build_non_dependent_expr (op1);
4789 op2 = build_non_dependent_expr (op2);
4792 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4793 /*overloaded_p=*/NULL);
4795 result = build_compound_expr (op1, op2);
4797 if (processing_template_decl && result != error_mark_node)
4798 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4803 /* Build a compound expression. */
4806 build_compound_expr (tree lhs, tree rhs)
4808 lhs = convert_to_void (lhs, "left-hand operand of comma");
4810 if (lhs == error_mark_node || rhs == error_mark_node)
4811 return error_mark_node;
4813 if (TREE_CODE (rhs) == TARGET_EXPR)
4815 /* If the rhs is a TARGET_EXPR, then build the compound
4816 expression inside the target_expr's initializer. This
4817 helps the compiler to eliminate unnecessary temporaries. */
4818 tree init = TREE_OPERAND (rhs, 1);
4820 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4821 TREE_OPERAND (rhs, 1) = init;
4826 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4829 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4830 casts away constness. DIAG_FN gives the function to call if we
4831 need to issue a diagnostic; if it is NULL, no diagnostic will be
4832 issued. DESCRIPTION explains what operation is taking place. */
4835 check_for_casting_away_constness (tree src_type, tree dest_type,
4836 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4837 const char *description)
4839 if (diag_fn && casts_away_constness (src_type, dest_type))
4840 diag_fn ("%s from type %qT to type %qT casts away constness",
4841 description, src_type, dest_type);
4844 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4845 (another pointer-to-member type in the same hierarchy) and return
4846 the converted expression. If ALLOW_INVERSE_P is permitted, a
4847 pointer-to-derived may be converted to pointer-to-base; otherwise,
4848 only the other direction is permitted. If C_CAST_P is true, this
4849 conversion is taking place as part of a C-style cast. */
4852 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4855 if (TYPE_PTRMEM_P (type))
4859 if (TREE_CODE (expr) == PTRMEM_CST)
4860 expr = cplus_expand_constant (expr);
4861 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4862 TYPE_PTRMEM_CLASS_TYPE (type),
4865 if (!integer_zerop (delta))
4866 expr = cp_build_binary_op (PLUS_EXPR,
4867 build_nop (ptrdiff_type_node, expr),
4869 return build_nop (type, expr);
4872 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4873 allow_inverse_p, c_cast_p);
4876 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4877 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4878 Otherwise, return EXPR unchanged. */
4881 ignore_overflows (tree expr, tree orig)
4883 if (TREE_CODE (expr) == INTEGER_CST
4884 && CONSTANT_CLASS_P (orig)
4885 && TREE_CODE (orig) != STRING_CST
4886 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4888 if (!TREE_OVERFLOW (orig))
4889 /* Ensure constant sharing. */
4890 expr = build_int_cst_wide (TREE_TYPE (expr),
4891 TREE_INT_CST_LOW (expr),
4892 TREE_INT_CST_HIGH (expr));
4895 /* Avoid clobbering a shared constant. */
4896 expr = copy_node (expr);
4897 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4903 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4904 this static_cast is being attempted as one of the possible casts
4905 allowed by a C-style cast. (In that case, accessibility of base
4906 classes is not considered, and it is OK to cast away
4907 constness.) Return the result of the cast. *VALID_P is set to
4908 indicate whether or not the cast was valid. */
4911 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4917 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4920 /* Assume the cast is valid. */
4923 intype = TREE_TYPE (expr);
4925 /* Save casted types in the function's used types hash table. */
4926 used_types_insert (type);
4928 /* Determine what to do when casting away constness. */
4931 /* C-style casts are allowed to cast away constness. With
4932 WARN_CAST_QUAL, we still want to issue a warning. */
4933 diag_fn = warn_cast_qual ? warning0 : NULL;
4938 /* A static_cast may not cast away constness. */
4940 desc = "static_cast";
4943 /* [expr.static.cast]
4945 An lvalue of type "cv1 B", where B is a class type, can be cast
4946 to type "reference to cv2 D", where D is a class derived (clause
4947 _class.derived_) from B, if a valid standard conversion from
4948 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4949 same cv-qualification as, or greater cv-qualification than, cv1,
4950 and B is not a virtual base class of D. */
4951 /* We check this case before checking the validity of "TYPE t =
4952 EXPR;" below because for this case:
4955 struct D : public B { D(const B&); };
4957 void f() { static_cast<const D&>(b); }
4959 we want to avoid constructing a new D. The standard is not
4960 completely clear about this issue, but our interpretation is
4961 consistent with other compilers. */
4962 if (TREE_CODE (type) == REFERENCE_TYPE
4963 && CLASS_TYPE_P (TREE_TYPE (type))
4964 && CLASS_TYPE_P (intype)
4965 && real_lvalue_p (expr)
4966 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4967 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4968 build_pointer_type (TYPE_MAIN_VARIANT
4969 (TREE_TYPE (type))))
4971 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4975 /* There is a standard conversion from "D*" to "B*" even if "B"
4976 is ambiguous or inaccessible. If this is really a
4977 static_cast, then we check both for inaccessibility and
4978 ambiguity. However, if this is a static_cast being performed
4979 because the user wrote a C-style cast, then accessibility is
4981 base = lookup_base (TREE_TYPE (type), intype,
4982 c_cast_p ? ba_unique : ba_check,
4985 /* Convert from "B*" to "D*". This function will check that "B"
4986 is not a virtual base of "D". */
4987 expr = build_base_path (MINUS_EXPR, build_address (expr),
4988 base, /*nonnull=*/false);
4989 /* Convert the pointer to a reference -- but then remember that
4990 there are no expressions with reference type in C++. */
4991 return convert_from_reference (build_nop (type, expr));
4996 /* [expr.static.cast]
4998 An expression e can be explicitly converted to a type T using a
4999 static_cast of the form static_cast<T>(e) if the declaration T
5000 t(e);" is well-formed, for some invented temporary variable
5002 result = perform_direct_initialization_if_possible (type, expr,
5006 result = convert_from_reference (result);
5008 /* Ignore any integer overflow caused by the cast. */
5009 result = ignore_overflows (result, orig);
5011 /* [expr.static.cast]
5013 If T is a reference type, the result is an lvalue; otherwise,
5014 the result is an rvalue. */
5015 if (TREE_CODE (type) != REFERENCE_TYPE)
5016 result = rvalue (result);
5020 /* [expr.static.cast]
5022 Any expression can be explicitly converted to type cv void. */
5023 if (TREE_CODE (type) == VOID_TYPE)
5024 return convert_to_void (expr, /*implicit=*/NULL);
5026 /* [expr.static.cast]
5028 The inverse of any standard conversion sequence (clause _conv_),
5029 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5030 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5031 (_conv.bool_) conversions, can be performed explicitly using
5032 static_cast subject to the restriction that the explicit
5033 conversion does not cast away constness (_expr.const.cast_), and
5034 the following additional rules for specific cases: */
5035 /* For reference, the conversions not excluded are: integral
5036 promotions, floating point promotion, integral conversions,
5037 floating point conversions, floating-integral conversions,
5038 pointer conversions, and pointer to member conversions. */
5041 A value of integral _or enumeration_ type can be explicitly
5042 converted to an enumeration type. */
5043 /* The effect of all that is that any conversion between any two
5044 types which are integral, floating, or enumeration types can be
5046 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5047 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5049 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5051 /* Ignore any integer overflow caused by the cast. */
5052 expr = ignore_overflows (expr, orig);
5056 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5057 && CLASS_TYPE_P (TREE_TYPE (type))
5058 && CLASS_TYPE_P (TREE_TYPE (intype))
5059 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5060 (TREE_TYPE (intype))),
5061 build_pointer_type (TYPE_MAIN_VARIANT
5062 (TREE_TYPE (type)))))
5067 check_for_casting_away_constness (intype, type, diag_fn, desc);
5068 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5069 c_cast_p ? ba_unique : ba_check,
5071 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5074 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5075 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5082 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5083 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5085 if (TYPE_PTRMEM_P (type))
5087 t1 = (build_ptrmem_type
5089 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5090 t2 = (build_ptrmem_type
5092 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5099 if (can_convert (t1, t2))
5102 check_for_casting_away_constness (intype, type, diag_fn,
5104 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5109 /* [expr.static.cast]
5111 An rvalue of type "pointer to cv void" can be explicitly
5112 converted to a pointer to object type. A value of type pointer
5113 to object converted to "pointer to cv void" and back to the
5114 original pointer type will have its original value. */
5115 if (TREE_CODE (intype) == POINTER_TYPE
5116 && VOID_TYPE_P (TREE_TYPE (intype))
5117 && TYPE_PTROB_P (type))
5120 check_for_casting_away_constness (intype, type, diag_fn, desc);
5121 return build_nop (type, expr);
5125 return error_mark_node;
5128 /* Return an expression representing static_cast<TYPE>(EXPR). */
5131 build_static_cast (tree type, tree expr)
5136 if (type == error_mark_node || expr == error_mark_node)
5137 return error_mark_node;
5139 if (processing_template_decl)
5141 expr = build_min (STATIC_CAST_EXPR, type, expr);
5142 /* We don't know if it will or will not have side effects. */
5143 TREE_SIDE_EFFECTS (expr) = 1;
5144 return convert_from_reference (expr);
5147 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5148 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5149 if (TREE_CODE (type) != REFERENCE_TYPE
5150 && TREE_CODE (expr) == NOP_EXPR
5151 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5152 expr = TREE_OPERAND (expr, 0);
5154 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5158 error ("invalid static_cast from type %qT to type %qT",
5159 TREE_TYPE (expr), type);
5160 return error_mark_node;
5163 /* EXPR is an expression with member function or pointer-to-member
5164 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5165 not permitted by ISO C++, but we accept it in some modes. If we
5166 are not in one of those modes, issue a diagnostic. Return the
5167 converted expression. */
5170 convert_member_func_to_ptr (tree type, tree expr)
5175 intype = TREE_TYPE (expr);
5176 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5177 || TREE_CODE (intype) == METHOD_TYPE);
5179 if (pedantic || warn_pmf2ptr)
5180 pedwarn ("converting from %qT to %qT", intype, type);
5182 if (TREE_CODE (intype) == METHOD_TYPE)
5183 expr = build_addr_func (expr);
5184 else if (TREE_CODE (expr) == PTRMEM_CST)
5185 expr = build_address (PTRMEM_CST_MEMBER (expr));
5188 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5189 decl = build_address (decl);
5190 expr = get_member_function_from_ptrfunc (&decl, expr);
5193 return build_nop (type, expr);
5196 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5197 If C_CAST_P is true, this reinterpret cast is being done as part of
5198 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5199 indicate whether or not reinterpret_cast was valid. */
5202 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5207 /* Assume the cast is invalid. */
5211 if (type == error_mark_node || error_operand_p (expr))
5212 return error_mark_node;
5214 intype = TREE_TYPE (expr);
5216 /* Save casted types in the function's used types hash table. */
5217 used_types_insert (type);
5219 /* [expr.reinterpret.cast]
5220 An lvalue expression of type T1 can be cast to the type
5221 "reference to T2" if an expression of type "pointer to T1" can be
5222 explicitly converted to the type "pointer to T2" using a
5223 reinterpret_cast. */
5224 if (TREE_CODE (type) == REFERENCE_TYPE)
5226 if (! real_lvalue_p (expr))
5228 error ("invalid cast of an rvalue expression of type "
5231 return error_mark_node;
5234 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5235 "B" are related class types; the reinterpret_cast does not
5236 adjust the pointer. */
5237 if (TYPE_PTR_P (intype)
5238 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5239 COMPARE_BASE | COMPARE_DERIVED)))
5240 warning (0, "casting %qT to %qT does not dereference pointer",
5243 expr = build_unary_op (ADDR_EXPR, expr, 0);
5244 if (expr != error_mark_node)
5245 expr = build_reinterpret_cast_1
5246 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5248 if (expr != error_mark_node)
5249 expr = build_indirect_ref (expr, 0);
5253 /* As a G++ extension, we consider conversions from member
5254 functions, and pointers to member functions to
5255 pointer-to-function and pointer-to-void types. If
5256 -Wno-pmf-conversions has not been specified,
5257 convert_member_func_to_ptr will issue an error message. */
5258 if ((TYPE_PTRMEMFUNC_P (intype)
5259 || TREE_CODE (intype) == METHOD_TYPE)
5260 && TYPE_PTR_P (type)
5261 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5262 || VOID_TYPE_P (TREE_TYPE (type))))
5263 return convert_member_func_to_ptr (type, expr);
5265 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5266 array-to-pointer, and function-to-pointer conversions are
5268 expr = decay_conversion (expr);
5270 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5271 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5272 if (TREE_CODE (expr) == NOP_EXPR
5273 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5274 expr = TREE_OPERAND (expr, 0);
5276 if (error_operand_p (expr))
5277 return error_mark_node;
5279 intype = TREE_TYPE (expr);
5281 /* [expr.reinterpret.cast]
5282 A pointer can be converted to any integral type large enough to
5284 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5286 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5287 pedwarn ("cast from %qT to %qT loses precision",
5290 /* [expr.reinterpret.cast]
5291 A value of integral or enumeration type can be explicitly
5292 converted to a pointer. */
5293 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5296 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5297 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5298 return fold_if_not_in_template (build_nop (type, expr));
5299 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5300 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5305 check_for_casting_away_constness (intype, type, error,
5306 "reinterpret_cast");
5307 /* Warn about possible alignment problems. */
5308 if (STRICT_ALIGNMENT && warn_cast_align
5309 && !VOID_TYPE_P (type)
5310 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5311 && COMPLETE_TYPE_P (TREE_TYPE (type))
5312 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5313 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5314 warning (0, "cast from %qT to %qT increases required alignment of "
5318 /* We need to strip nops here, because the front end likes to
5319 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5321 if (warn_strict_aliasing <= 2)
5322 strict_aliasing_warning (intype, type, sexpr);
5324 return fold_if_not_in_template (build_nop (type, expr));
5326 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5327 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5330 /* Only issue a warning, as we have always supported this
5331 where possible, and it is necessary in some cases. DR 195
5332 addresses this issue, but as of 2004/10/26 is still in
5334 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5335 return fold_if_not_in_template (build_nop (type, expr));
5337 else if (TREE_CODE (type) == VECTOR_TYPE)
5338 return fold_if_not_in_template (convert_to_vector (type, expr));
5339 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5340 return fold_if_not_in_template (convert_to_integer (type, expr));
5345 error ("invalid cast from type %qT to type %qT", intype, type);
5346 return error_mark_node;
5349 return cp_convert (type, expr);
5353 build_reinterpret_cast (tree type, tree expr)
5355 if (type == error_mark_node || expr == error_mark_node)
5356 return error_mark_node;
5358 if (processing_template_decl)
5360 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5362 if (!TREE_SIDE_EFFECTS (t)
5363 && type_dependent_expression_p (expr))
5364 /* There might turn out to be side effects inside expr. */
5365 TREE_SIDE_EFFECTS (t) = 1;
5366 return convert_from_reference (t);
5369 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5373 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5374 return an appropriate expression. Otherwise, return
5375 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5376 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5377 performing a C-style cast, its value upon return will indicate
5378 whether or not the conversion succeeded. */
5381 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5385 tree reference_type;
5387 /* Callers are responsible for handling error_mark_node as a
5388 destination type. */
5389 gcc_assert (dst_type != error_mark_node);
5390 /* In a template, callers should be building syntactic
5391 representations of casts, not using this machinery. */
5392 gcc_assert (!processing_template_decl);
5394 /* Assume the conversion is invalid. */
5398 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5401 error ("invalid use of const_cast with type %qT, "
5402 "which is not a pointer, "
5403 "reference, nor a pointer-to-data-member type", dst_type);
5404 return error_mark_node;
5407 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5410 error ("invalid use of const_cast with type %qT, which is a pointer "
5411 "or reference to a function type", dst_type);
5412 return error_mark_node;
5415 /* Save casted types in the function's used types hash table. */
5416 used_types_insert (dst_type);
5418 src_type = TREE_TYPE (expr);
5419 /* Expressions do not really have reference types. */
5420 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5421 src_type = TREE_TYPE (src_type);
5423 /* [expr.const.cast]
5425 An lvalue of type T1 can be explicitly converted to an lvalue of
5426 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5427 types) if a pointer to T1 can be explicitly converted to the type
5428 pointer to T2 using a const_cast. */
5429 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5431 reference_type = dst_type;
5432 if (! real_lvalue_p (expr))
5435 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5436 src_type, dst_type);
5437 return error_mark_node;
5439 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5440 src_type = build_pointer_type (src_type);
5444 reference_type = NULL_TREE;
5445 /* If the destination type is not a reference type, the
5446 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5447 conversions are performed. */
5448 src_type = type_decays_to (src_type);
5449 if (src_type == error_mark_node)
5450 return error_mark_node;
5453 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5454 && comp_ptr_ttypes_const (dst_type, src_type))
5459 /* This cast is actually a C-style cast. Issue a warning if
5460 the user is making a potentially unsafe cast. */
5462 check_for_casting_away_constness (src_type, dst_type,
5468 expr = build_unary_op (ADDR_EXPR, expr, 0);
5469 expr = build_nop (reference_type, expr);
5470 return convert_from_reference (expr);
5474 expr = decay_conversion (expr);
5475 /* build_c_cast puts on a NOP_EXPR to make the result not an
5476 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5477 non-lvalue context. */
5478 if (TREE_CODE (expr) == NOP_EXPR
5479 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5480 expr = TREE_OPERAND (expr, 0);
5481 return build_nop (dst_type, expr);
5486 error ("invalid const_cast from type %qT to type %qT",
5487 src_type, dst_type);
5488 return error_mark_node;
5492 build_const_cast (tree type, tree expr)
5494 if (type == error_mark_node || error_operand_p (expr))
5495 return error_mark_node;
5497 if (processing_template_decl)
5499 tree t = build_min (CONST_CAST_EXPR, type, expr);
5501 if (!TREE_SIDE_EFFECTS (t)
5502 && type_dependent_expression_p (expr))
5503 /* There might turn out to be side effects inside expr. */
5504 TREE_SIDE_EFFECTS (t) = 1;
5505 return convert_from_reference (t);
5508 return build_const_cast_1 (type, expr, /*complain=*/true,
5512 /* Build an expression representing an explicit C-style cast to type
5513 TYPE of expression EXPR. */
5516 build_c_cast (tree type, tree expr)
5522 if (type == error_mark_node || error_operand_p (expr))
5523 return error_mark_node;
5525 if (processing_template_decl)
5527 tree t = build_min (CAST_EXPR, type,
5528 tree_cons (NULL_TREE, value, NULL_TREE));
5529 /* We don't know if it will or will not have side effects. */
5530 TREE_SIDE_EFFECTS (t) = 1;
5531 return convert_from_reference (t);
5534 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5535 'Class') should always be retained, because this information aids
5536 in method lookup. */
5537 if (objc_is_object_ptr (type)
5538 && objc_is_object_ptr (TREE_TYPE (expr)))
5539 return build_nop (type, expr);
5541 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5542 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5543 if (TREE_CODE (type) != REFERENCE_TYPE
5544 && TREE_CODE (value) == NOP_EXPR
5545 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5546 value = TREE_OPERAND (value, 0);
5548 if (TREE_CODE (type) == ARRAY_TYPE)
5550 /* Allow casting from T1* to T2[] because Cfront allows it.
5551 NIHCL uses it. It is not valid ISO C++ however. */
5552 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5554 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5555 type = build_pointer_type (TREE_TYPE (type));
5559 error ("ISO C++ forbids casting to an array type %qT", type);
5560 return error_mark_node;
5564 if (TREE_CODE (type) == FUNCTION_TYPE
5565 || TREE_CODE (type) == METHOD_TYPE)
5567 error ("invalid cast to function type %qT", type);
5568 return error_mark_node;
5571 /* A C-style cast can be a const_cast. */
5572 result = build_const_cast_1 (type, value, /*complain=*/false,
5577 /* Or a static cast. */
5578 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5580 /* Or a reinterpret_cast. */
5582 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5584 /* The static_cast or reinterpret_cast may be followed by a
5587 /* A valid cast may result in errors if, for example, a
5588 conversion to am ambiguous base class is required. */
5589 && !error_operand_p (result))
5593 /* Non-class rvalues always have cv-unqualified type. */
5594 if (!CLASS_TYPE_P (type))
5595 type = TYPE_MAIN_VARIANT (type);
5596 result_type = TREE_TYPE (result);
5597 if (!CLASS_TYPE_P (result_type))
5598 result_type = TYPE_MAIN_VARIANT (result_type);
5599 /* If the type of RESULT does not match TYPE, perform a
5600 const_cast to make it match. If the static_cast or
5601 reinterpret_cast succeeded, we will differ by at most
5602 cv-qualification, so the follow-on const_cast is guaranteed
5604 if (!same_type_p (non_reference (type), non_reference (result_type)))
5606 result = build_const_cast_1 (type, result, false, &valid_p);
5607 gcc_assert (valid_p);
5612 return error_mark_node;
5615 /* Build an assignment expression of lvalue LHS from value RHS.
5616 MODIFYCODE is the code for a binary operator that we use
5617 to combine the old value of LHS with RHS to get the new value.
5618 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5620 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5623 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5627 tree lhstype = TREE_TYPE (lhs);
5628 tree olhstype = lhstype;
5629 tree olhs = NULL_TREE;
5630 bool plain_assign = (modifycode == NOP_EXPR);
5632 /* Avoid duplicate error messages from operands that had errors. */
5633 if (error_operand_p (lhs) || error_operand_p (rhs))
5634 return error_mark_node;
5636 /* Handle control structure constructs used as "lvalues". */
5637 switch (TREE_CODE (lhs))
5639 /* Handle --foo = 5; as these are valid constructs in C++. */
5640 case PREDECREMENT_EXPR:
5641 case PREINCREMENT_EXPR:
5642 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5643 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5644 stabilize_reference (TREE_OPERAND (lhs, 0)),
5645 TREE_OPERAND (lhs, 1));
5646 return build2 (COMPOUND_EXPR, lhstype,
5648 build_modify_expr (TREE_OPERAND (lhs, 0),
5651 /* Handle (a, b) used as an "lvalue". */
5653 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5655 if (newrhs == error_mark_node)
5656 return error_mark_node;
5657 return build2 (COMPOUND_EXPR, lhstype,
5658 TREE_OPERAND (lhs, 0), newrhs);
5661 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5662 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5663 stabilize_reference (TREE_OPERAND (lhs, 0)),
5664 TREE_OPERAND (lhs, 1));
5665 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5666 if (newrhs == error_mark_node)
5667 return error_mark_node;
5668 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5672 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5673 when neither operand has side-effects. */
5674 if (!lvalue_or_else (lhs, lv_assign))
5675 return error_mark_node;
5677 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5678 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5680 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5681 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5683 TREE_OPERAND (lhs, 0),
5684 TREE_OPERAND (lhs, 1)),
5685 TREE_OPERAND (lhs, 0),
5686 TREE_OPERAND (lhs, 1));
5689 /* Handle (a ? b : c) used as an "lvalue". */
5692 /* Produce (a ? (b = rhs) : (c = rhs))
5693 except that the RHS goes through a save-expr
5694 so the code to compute it is only emitted once. */
5696 tree preeval = NULL_TREE;
5698 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5700 error ("void value not ignored as it ought to be");
5701 return error_mark_node;
5704 rhs = stabilize_expr (rhs, &preeval);
5706 /* Check this here to avoid odd errors when trying to convert
5707 a throw to the type of the COND_EXPR. */
5708 if (!lvalue_or_else (lhs, lv_assign))
5709 return error_mark_node;
5711 cond = build_conditional_expr
5712 (TREE_OPERAND (lhs, 0),
5713 build_modify_expr (TREE_OPERAND (lhs, 1),
5715 build_modify_expr (TREE_OPERAND (lhs, 2),
5718 if (cond == error_mark_node)
5720 /* Make sure the code to compute the rhs comes out
5721 before the split. */
5723 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5731 if (modifycode == INIT_EXPR)
5733 if (TREE_CODE (rhs) == CONSTRUCTOR)
5735 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5736 /* Call convert to generate an error; see PR 11063. */
5737 rhs = convert (lhstype, rhs);
5738 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5739 TREE_SIDE_EFFECTS (result) = 1;
5742 else if (! IS_AGGR_TYPE (lhstype))
5743 /* Do the default thing. */;
5746 result = build_special_member_call (lhs, complete_ctor_identifier,
5747 build_tree_list (NULL_TREE, rhs),
5748 lhstype, LOOKUP_NORMAL);
5749 if (result == NULL_TREE)
5750 return error_mark_node;
5756 lhs = require_complete_type (lhs);
5757 if (lhs == error_mark_node)
5758 return error_mark_node;
5760 if (modifycode == NOP_EXPR)
5762 /* `operator=' is not an inheritable operator. */
5763 if (! IS_AGGR_TYPE (lhstype))
5764 /* Do the default thing. */;
5767 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5768 lhs, rhs, make_node (NOP_EXPR),
5769 /*overloaded_p=*/NULL);
5770 if (result == NULL_TREE)
5771 return error_mark_node;
5778 /* A binary op has been requested. Combine the old LHS
5779 value with the RHS producing the value we should actually
5780 store into the LHS. */
5782 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5783 lhs = stabilize_reference (lhs);
5784 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5785 if (newrhs == error_mark_node)
5787 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5788 TREE_TYPE (lhs), TREE_TYPE (rhs));
5789 return error_mark_node;
5792 /* Now it looks like a plain assignment. */
5793 modifycode = NOP_EXPR;
5795 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5796 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5799 /* The left-hand side must be an lvalue. */
5800 if (!lvalue_or_else (lhs, lv_assign))
5801 return error_mark_node;
5803 /* Warn about modifying something that is `const'. Don't warn if
5804 this is initialization. */
5805 if (modifycode != INIT_EXPR
5806 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5807 /* Functions are not modifiable, even though they are
5809 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5810 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5811 /* If it's an aggregate and any field is const, then it is
5812 effectively const. */
5813 || (CLASS_TYPE_P (lhstype)
5814 && C_TYPE_FIELDS_READONLY (lhstype))))
5815 readonly_error (lhs, "assignment");
5817 /* If storing into a structure or union member, it has probably been
5818 given type `int'. Compute the type that would go with the actual
5819 amount of storage the member occupies. */
5821 if (TREE_CODE (lhs) == COMPONENT_REF
5822 && (TREE_CODE (lhstype) == INTEGER_TYPE
5823 || TREE_CODE (lhstype) == REAL_TYPE
5824 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5826 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5828 /* If storing in a field that is in actuality a short or narrower
5829 than one, we must store in the field in its actual type. */
5831 if (lhstype != TREE_TYPE (lhs))
5833 /* Avoid warnings converting integral types back into enums for
5835 if (TREE_CODE (lhstype) == INTEGER_TYPE
5836 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5838 if (TREE_SIDE_EFFECTS (lhs))
5839 lhs = stabilize_reference (lhs);
5842 lhs = copy_node (lhs);
5843 TREE_TYPE (lhs) = lhstype;
5847 /* Convert new value to destination type. */
5849 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5853 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5854 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5856 error ("incompatible types in assignment of %qT to %qT",
5857 TREE_TYPE (rhs), lhstype);
5858 return error_mark_node;
5861 /* Allow array assignment in compiler-generated code. */
5862 if (! DECL_ARTIFICIAL (current_function_decl))
5864 /* This routine is used for both initialization and assignment.
5865 Make sure the diagnostic message differentiates the context. */
5866 if (modifycode == INIT_EXPR)
5867 error ("array used as initializer");
5869 error ("invalid array assignment");
5870 return error_mark_node;
5873 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5874 ? 1 + (modifycode != INIT_EXPR): 0;
5875 return build_vec_init (lhs, NULL_TREE, newrhs,
5876 /*explicit_default_init_p=*/false,
5880 if (modifycode == INIT_EXPR)
5881 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5882 "initialization", NULL_TREE, 0);
5885 /* Avoid warnings on enum bit fields. */
5886 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5887 && TREE_CODE (lhstype) == INTEGER_TYPE)
5889 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5891 newrhs = convert_force (lhstype, newrhs, 0);
5894 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5896 if (TREE_CODE (newrhs) == CALL_EXPR
5897 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5898 newrhs = build_cplus_new (lhstype, newrhs);
5900 /* Can't initialize directly from a TARGET_EXPR, since that would
5901 cause the lhs to be constructed twice, and possibly result in
5902 accidental self-initialization. So we force the TARGET_EXPR to be
5903 expanded without a target. */
5904 if (TREE_CODE (newrhs) == TARGET_EXPR)
5905 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5906 TREE_OPERAND (newrhs, 0));
5909 if (newrhs == error_mark_node)
5910 return error_mark_node;
5912 if (c_dialect_objc () && flag_objc_gc)
5914 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5920 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5921 lhstype, lhs, newrhs);
5923 TREE_SIDE_EFFECTS (result) = 1;
5925 TREE_NO_WARNING (result) = 1;
5927 /* If we got the LHS in a different type for storing in,
5928 convert the result back to the nominal type of LHS
5929 so that the value we return always has the same type
5930 as the LHS argument. */
5932 if (olhstype == TREE_TYPE (result))
5936 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5937 TREE_NO_WARNING (result) = 1;
5940 return convert_for_assignment (olhstype, result, "assignment",
5945 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5947 if (processing_template_decl)
5948 return build_min_nt (MODOP_EXPR, lhs,
5949 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5951 if (modifycode != NOP_EXPR)
5953 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5954 make_node (modifycode),
5955 /*overloaded_p=*/NULL);
5958 TREE_NO_WARNING (rval) = 1;
5962 return build_modify_expr (lhs, modifycode, rhs);
5966 /* Get difference in deltas for different pointer to member function
5967 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5968 the conversion is invalid, the constant is zero. If
5969 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5970 If C_CAST_P is true this conversion is taking place as part of a
5973 Note that the naming of FROM and TO is kind of backwards; the return
5974 value is what we add to a TO in order to get a FROM. They are named
5975 this way because we call this function to find out how to convert from
5976 a pointer to member of FROM to a pointer to member of TO. */
5979 get_delta_difference (tree from, tree to,
5980 bool allow_inverse_p,
5987 /* Assume no conversion is required. */
5988 result = integer_zero_node;
5989 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5990 if (kind == bk_inaccessible || kind == bk_ambig)
5991 error (" in pointer to member function conversion");
5994 if (kind != bk_via_virtual)
5995 result = BINFO_OFFSET (binfo);
5998 tree virt_binfo = binfo_from_vbase (binfo);
6000 /* This is a reinterpret cast, we choose to do nothing. */
6001 if (allow_inverse_p)
6002 warning (0, "pointer to member cast via virtual base %qT",
6003 BINFO_TYPE (virt_binfo));
6005 error ("pointer to member conversion via virtual base %qT",
6006 BINFO_TYPE (virt_binfo));
6009 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
6010 /* Pointer to member of incomplete class is permitted*/;
6011 else if (!allow_inverse_p)
6013 error_not_base_type (from, to);
6014 error (" in pointer to member conversion");
6018 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6021 if (kind != bk_via_virtual)
6022 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6025 /* This is a reinterpret cast, we choose to do nothing. */
6026 tree virt_binfo = binfo_from_vbase (binfo);
6028 warning (0, "pointer to member cast via virtual base %qT",
6029 BINFO_TYPE (virt_binfo));
6034 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6038 /* Return a constructor for the pointer-to-member-function TYPE using
6039 the other components as specified. */
6042 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6047 VEC(constructor_elt, gc) *v;
6049 /* Pull the FIELD_DECLs out of the type. */
6050 pfn_field = TYPE_FIELDS (type);
6051 delta_field = TREE_CHAIN (pfn_field);
6053 /* Make sure DELTA has the type we want. */
6054 delta = convert_and_check (delta_type_node, delta);
6056 /* Finish creating the initializer. */
6057 v = VEC_alloc(constructor_elt, gc, 2);
6058 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6059 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6060 u = build_constructor (type, v);
6061 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6062 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6063 TREE_STATIC (u) = (TREE_CONSTANT (u)
6064 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6066 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6071 /* Build a constructor for a pointer to member function. It can be
6072 used to initialize global variables, local variable, or used
6073 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6076 If FORCE is nonzero, then force this conversion, even if
6077 we would rather not do it. Usually set when using an explicit
6078 cast. A C-style cast is being processed iff C_CAST_P is true.
6080 Return error_mark_node, if something goes wrong. */
6083 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6089 if (error_operand_p (pfn))
6090 return error_mark_node;
6092 pfn_type = TREE_TYPE (pfn);
6093 to_type = build_ptrmemfunc_type (type);
6095 /* Handle multiple conversions of pointer to member functions. */
6096 if (TYPE_PTRMEMFUNC_P (pfn_type))
6098 tree delta = NULL_TREE;
6099 tree npfn = NULL_TREE;
6103 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6104 error ("invalid conversion to type %qT from type %qT",
6107 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6108 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6112 /* We don't have to do any conversion to convert a
6113 pointer-to-member to its own type. But, we don't want to
6114 just return a PTRMEM_CST if there's an explicit cast; that
6115 cast should make the expression an invalid template argument. */
6116 if (TREE_CODE (pfn) != PTRMEM_CST)
6118 if (same_type_p (to_type, pfn_type))
6120 else if (integer_zerop (n))
6121 return build_reinterpret_cast (to_type, pfn);
6124 if (TREE_SIDE_EFFECTS (pfn))
6125 pfn = save_expr (pfn);
6127 /* Obtain the function pointer and the current DELTA. */
6128 if (TREE_CODE (pfn) == PTRMEM_CST)
6129 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6132 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6133 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6136 /* Just adjust the DELTA field. */
6137 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6138 (TREE_TYPE (delta), ptrdiff_type_node));
6139 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6140 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6141 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6142 return build_ptrmemfunc1 (to_type, delta, npfn);
6145 /* Handle null pointer to member function conversions. */
6146 if (integer_zerop (pfn))
6148 pfn = build_c_cast (type, integer_zero_node);
6149 return build_ptrmemfunc1 (to_type,
6154 if (type_unknown_p (pfn))
6155 return instantiate_type (type, pfn, tf_warning_or_error);
6157 fn = TREE_OPERAND (pfn, 0);
6158 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6159 /* In a template, we will have preserved the
6161 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6162 return make_ptrmem_cst (to_type, fn);
6165 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6168 ??? There is no consistency as to the types returned for the above
6169 values. Some code acts as if it were a sizetype and some as if it were
6170 integer_type_node. */
6173 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6175 tree type = TREE_TYPE (cst);
6176 tree fn = PTRMEM_CST_MEMBER (cst);
6177 tree ptr_class, fn_class;
6179 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6181 /* The class that the function belongs to. */
6182 fn_class = DECL_CONTEXT (fn);
6184 /* The class that we're creating a pointer to member of. */
6185 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6187 /* First, calculate the adjustment to the function's class. */
6188 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6191 if (!DECL_VIRTUAL_P (fn))
6192 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6195 /* If we're dealing with a virtual function, we have to adjust 'this'
6196 again, to point to the base which provides the vtable entry for
6197 fn; the call will do the opposite adjustment. */
6198 tree orig_class = DECL_CONTEXT (fn);
6199 tree binfo = binfo_or_else (orig_class, fn_class);
6200 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6201 *delta, BINFO_OFFSET (binfo));
6202 *delta = fold_if_not_in_template (*delta);
6204 /* We set PFN to the vtable offset at which the function can be
6205 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6206 case delta is shifted left, and then incremented). */
6207 *pfn = DECL_VINDEX (fn);
6208 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6209 TYPE_SIZE_UNIT (vtable_entry_type));
6210 *pfn = fold_if_not_in_template (*pfn);
6212 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6214 case ptrmemfunc_vbit_in_pfn:
6215 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6217 *pfn = fold_if_not_in_template (*pfn);
6220 case ptrmemfunc_vbit_in_delta:
6221 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6222 *delta, integer_one_node);
6223 *delta = fold_if_not_in_template (*delta);
6224 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6225 *delta, integer_one_node);
6226 *delta = fold_if_not_in_template (*delta);
6233 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6234 *pfn = fold_if_not_in_template (*pfn);
6238 /* Return an expression for PFN from the pointer-to-member function
6242 pfn_from_ptrmemfunc (tree t)
6244 if (TREE_CODE (t) == PTRMEM_CST)
6249 expand_ptrmemfunc_cst (t, &delta, &pfn);
6254 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6257 /* Convert value RHS to type TYPE as preparation for an assignment to
6258 an lvalue of type TYPE. ERRTYPE is a string to use in error
6259 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6260 are doing the conversion in order to pass the PARMNUMth argument of
6264 convert_for_assignment (tree type, tree rhs,
6265 const char *errtype, tree fndecl, int parmnum)
6268 enum tree_code coder;
6270 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6271 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6272 rhs = TREE_OPERAND (rhs, 0);
6274 rhstype = TREE_TYPE (rhs);
6275 coder = TREE_CODE (rhstype);
6277 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6278 && vector_types_convertible_p (type, rhstype, true))
6279 return convert (type, rhs);
6281 if (rhs == error_mark_node || rhstype == error_mark_node)
6282 return error_mark_node;
6283 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6284 return error_mark_node;
6286 /* The RHS of an assignment cannot have void type. */
6287 if (coder == VOID_TYPE)
6289 error ("void value not ignored as it ought to be");
6290 return error_mark_node;
6293 /* Simplify the RHS if possible. */
6294 if (TREE_CODE (rhs) == CONST_DECL)
6295 rhs = DECL_INITIAL (rhs);
6297 if (c_dialect_objc ())
6300 tree rname = fndecl;
6302 if (!strcmp (errtype, "assignment"))
6304 else if (!strcmp (errtype, "initialization"))
6308 tree selector = objc_message_selector ();
6312 if (selector && parmno > 1)
6319 if (objc_compare_types (type, rhstype, parmno, rname))
6320 return convert (type, rhs);
6325 The expression is implicitly converted (clause _conv_) to the
6326 cv-unqualified type of the left operand.
6328 We allow bad conversions here because by the time we get to this point
6329 we are committed to doing the conversion. If we end up doing a bad
6330 conversion, convert_like will complain. */
6331 if (!can_convert_arg_bad (type, rhstype, rhs))
6333 /* When -Wno-pmf-conversions is use, we just silently allow
6334 conversions from pointers-to-members to plain pointers. If
6335 the conversion doesn't work, cp_convert will complain. */
6337 && TYPE_PTR_P (type)
6338 && TYPE_PTRMEMFUNC_P (rhstype))
6339 rhs = cp_convert (strip_top_quals (type), rhs);
6342 /* If the right-hand side has unknown type, then it is an
6343 overloaded function. Call instantiate_type to get error
6345 if (rhstype == unknown_type_node)
6346 instantiate_type (type, rhs, tf_warning_or_error);
6348 error ("cannot convert %qT to %qT for argument %qP to %qD",
6349 rhstype, type, parmnum, fndecl);
6351 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6352 return error_mark_node;
6355 if (warn_missing_format_attribute)
6357 const enum tree_code codel = TREE_CODE (type);
6358 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6360 && check_missing_format_attribute (type, rhstype))
6361 warning (OPT_Wmissing_format_attribute,
6362 "%s might be a candidate for a format attribute",
6366 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6368 if (warn_parentheses
6369 && type == boolean_type_node
6370 && TREE_CODE (rhs) == MODIFY_EXPR
6371 && !TREE_NO_WARNING (rhs)
6372 && TREE_TYPE (rhs) != boolean_type_node)
6374 warning (OPT_Wparentheses,
6375 "suggest parentheses around assignment used as truth value");
6376 TREE_NO_WARNING (rhs) = 1;
6379 return perform_implicit_conversion (strip_top_quals (type), rhs);
6382 /* Convert RHS to be of type TYPE.
6383 If EXP is nonzero, it is the target of the initialization.
6384 ERRTYPE is a string to use in error messages.
6386 Two major differences between the behavior of
6387 `convert_for_assignment' and `convert_for_initialization'
6388 are that references are bashed in the former, while
6389 copied in the latter, and aggregates are assigned in
6390 the former (operator=) while initialized in the
6393 If using constructor make sure no conversion operator exists, if one does
6394 exist, an ambiguity exists.
6396 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6399 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6400 const char *errtype, tree fndecl, int parmnum)
6402 enum tree_code codel = TREE_CODE (type);
6404 enum tree_code coder;
6406 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6407 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6408 if (TREE_CODE (rhs) == NOP_EXPR
6409 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6410 && codel != REFERENCE_TYPE)
6411 rhs = TREE_OPERAND (rhs, 0);
6413 if (type == error_mark_node
6414 || rhs == error_mark_node
6415 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6416 return error_mark_node;
6418 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6419 && TREE_CODE (type) != ARRAY_TYPE
6420 && (TREE_CODE (type) != REFERENCE_TYPE
6421 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6422 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6423 && (TREE_CODE (type) != REFERENCE_TYPE
6424 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6425 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6426 rhs = decay_conversion (rhs);
6428 rhstype = TREE_TYPE (rhs);
6429 coder = TREE_CODE (rhstype);
6431 if (coder == ERROR_MARK)
6432 return error_mark_node;
6434 /* We accept references to incomplete types, so we can
6435 return here before checking if RHS is of complete type. */
6437 if (codel == REFERENCE_TYPE)
6439 /* This should eventually happen in convert_arguments. */
6440 int savew = 0, savee = 0;
6443 savew = warningcount, savee = errorcount;
6444 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6448 if (warningcount > savew)
6449 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6450 else if (errorcount > savee)
6451 error ("in passing argument %P of %q+D", parmnum, fndecl);
6457 exp = require_complete_type (exp);
6458 if (exp == error_mark_node)
6459 return error_mark_node;
6461 rhstype = non_reference (rhstype);
6463 type = complete_type (type);
6465 if (IS_AGGR_TYPE (type))
6466 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6468 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6471 /* If RETVAL is the address of, or a reference to, a local variable or
6472 temporary give an appropriate warning. */
6475 maybe_warn_about_returning_address_of_local (tree retval)
6477 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6478 tree whats_returned = retval;
6482 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6483 whats_returned = TREE_OPERAND (whats_returned, 1);
6484 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6485 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6486 || TREE_CODE (whats_returned) == NOP_EXPR)
6487 whats_returned = TREE_OPERAND (whats_returned, 0);
6492 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6494 whats_returned = TREE_OPERAND (whats_returned, 0);
6496 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6498 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6499 || TREE_CODE (whats_returned) == TARGET_EXPR)
6501 warning (0, "returning reference to temporary");
6504 if (TREE_CODE (whats_returned) == VAR_DECL
6505 && DECL_NAME (whats_returned)
6506 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6508 warning (0, "reference to non-lvalue returned");
6513 while (TREE_CODE (whats_returned) == COMPONENT_REF
6514 || TREE_CODE (whats_returned) == ARRAY_REF)
6515 whats_returned = TREE_OPERAND (whats_returned, 0);
6517 if (DECL_P (whats_returned)
6518 && DECL_NAME (whats_returned)
6519 && DECL_FUNCTION_SCOPE_P (whats_returned)
6520 && !(TREE_STATIC (whats_returned)
6521 || TREE_PUBLIC (whats_returned)))
6523 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6524 warning (0, "reference to local variable %q+D returned",
6527 warning (0, "address of local variable %q+D returned",
6533 /* Check that returning RETVAL from the current function is valid.
6534 Return an expression explicitly showing all conversions required to
6535 change RETVAL into the function return type, and to assign it to
6536 the DECL_RESULT for the function. Set *NO_WARNING to true if
6537 code reaches end of non-void function warning shouldn't be issued
6538 on this RETURN_EXPR. */
6541 check_return_expr (tree retval, bool *no_warning)
6544 /* The type actually returned by the function, after any
6547 int fn_returns_value_p;
6548 bool named_return_value_okay_p;
6550 *no_warning = false;
6552 /* A `volatile' function is one that isn't supposed to return, ever.
6553 (This is a G++ extension, used to get better code for functions
6554 that call the `volatile' function.) */
6555 if (TREE_THIS_VOLATILE (current_function_decl))
6556 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6558 /* Check for various simple errors. */
6559 if (DECL_DESTRUCTOR_P (current_function_decl))
6562 error ("returning a value from a destructor");
6565 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6567 if (in_function_try_handler)
6568 /* If a return statement appears in a handler of the
6569 function-try-block of a constructor, the program is ill-formed. */
6570 error ("cannot return from a handler of a function-try-block of a constructor");
6572 /* You can't return a value from a constructor. */
6573 error ("returning a value from a constructor");
6577 if (processing_template_decl)
6579 current_function_returns_value = 1;
6580 check_for_bare_parameter_packs (retval);
6584 /* When no explicit return-value is given in a function with a named
6585 return value, the named return value is used. */
6586 result = DECL_RESULT (current_function_decl);
6587 valtype = TREE_TYPE (result);
6588 gcc_assert (valtype != NULL_TREE);
6589 fn_returns_value_p = !VOID_TYPE_P (valtype);
6590 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6593 /* Check for a return statement with no return value in a function
6594 that's supposed to return a value. */
6595 if (!retval && fn_returns_value_p)
6597 pedwarn ("return-statement with no value, in function returning %qT",
6599 /* Clear this, so finish_function won't say that we reach the
6600 end of a non-void function (which we don't, we gave a
6602 current_function_returns_null = 0;
6603 /* And signal caller that TREE_NO_WARNING should be set on the
6604 RETURN_EXPR to avoid control reaches end of non-void function
6605 warnings in tree-cfg.c. */
6608 /* Check for a return statement with a value in a function that
6609 isn't supposed to return a value. */
6610 else if (retval && !fn_returns_value_p)
6612 if (VOID_TYPE_P (TREE_TYPE (retval)))
6613 /* You can return a `void' value from a function of `void'
6614 type. In that case, we have to evaluate the expression for
6615 its side-effects. */
6616 finish_expr_stmt (retval);
6618 pedwarn ("return-statement with a value, in function "
6619 "returning 'void'");
6621 current_function_returns_null = 1;
6623 /* There's really no value to return, after all. */
6627 /* Remember that this function can sometimes return without a
6629 current_function_returns_null = 1;
6631 /* Remember that this function did return a value. */
6632 current_function_returns_value = 1;
6634 /* Check for erroneous operands -- but after giving ourselves a
6635 chance to provide an error about returning a value from a void
6637 if (error_operand_p (retval))
6639 current_function_return_value = error_mark_node;
6640 return error_mark_node;
6643 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6644 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6645 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6646 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6648 && null_ptr_cst_p (retval))
6649 warning (0, "%<operator new%> must not return NULL unless it is "
6650 "declared %<throw()%> (or -fcheck-new is in effect)");
6652 /* Effective C++ rule 15. See also start_function. */
6654 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6658 /* The function return type must be a reference to the current
6660 if (TREE_CODE (valtype) == REFERENCE_TYPE
6661 && same_type_ignoring_top_level_qualifiers_p
6662 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6664 /* Returning '*this' is obviously OK. */
6665 if (retval == current_class_ref)
6667 /* If we are calling a function whose return type is the same of
6668 the current class reference, it is ok. */
6669 else if (TREE_CODE (retval) == INDIRECT_REF
6670 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6675 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6678 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6680 [...] For a function with a class return type, if the expression
6681 in the return statement is the name of a local object, and the cv-
6682 unqualified type of the local object is the same as the function
6683 return type, an implementation is permitted to omit creating the tem-
6684 porary object to hold the function return value [...]
6686 So, if this is a value-returning function that always returns the same
6687 local variable, remember it.
6689 It might be nice to be more flexible, and choose the first suitable
6690 variable even if the function sometimes returns something else, but
6691 then we run the risk of clobbering the variable we chose if the other
6692 returned expression uses the chosen variable somehow. And people expect
6693 this restriction, anyway. (jason 2000-11-19)
6695 See finish_function and finalize_nrv for the rest of this optimization. */
6697 named_return_value_okay_p =
6698 (retval != NULL_TREE
6699 /* Must be a local, automatic variable. */
6700 && TREE_CODE (retval) == VAR_DECL
6701 && DECL_CONTEXT (retval) == current_function_decl
6702 && ! TREE_STATIC (retval)
6703 && (DECL_ALIGN (retval)
6704 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6705 /* The cv-unqualified type of the returned value must be the
6706 same as the cv-unqualified return type of the
6708 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
6710 (TREE_TYPE (TREE_TYPE (current_function_decl))))));
6712 if (fn_returns_value_p && flag_elide_constructors)
6714 if (named_return_value_okay_p
6715 && (current_function_return_value == NULL_TREE
6716 || current_function_return_value == retval))
6717 current_function_return_value = retval;
6719 current_function_return_value = error_mark_node;
6722 /* We don't need to do any conversions when there's nothing being
6727 /* Do any required conversions. */
6728 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6729 /* No conversions are required. */
6733 /* The type the function is declared to return. */
6734 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6735 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
6737 /* The functype's return type will have been set to void, if it
6738 was an incomplete type. Just treat this as 'return;' */
6739 if (VOID_TYPE_P (functype))
6740 return error_mark_node;
6742 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
6743 treated as an rvalue for the purposes of overload resolution to
6744 favor move constructors over copy constructors. */
6745 if ((cxx_dialect != cxx98)
6746 && named_return_value_okay_p
6747 /* The variable must not have the `volatile' qualifier. */
6748 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
6749 /* The return type must be a class type. */
6750 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
6751 flags = flags | LOOKUP_PREFER_RVALUE;
6753 /* First convert the value to the function's return type, then
6754 to the type of return value's location to handle the
6755 case that functype is smaller than the valtype. */
6756 retval = convert_for_initialization
6757 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0);
6758 retval = convert (valtype, retval);
6760 /* If the conversion failed, treat this just like `return;'. */
6761 if (retval == error_mark_node)
6763 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6764 else if (! current_function_returns_struct
6765 && TREE_CODE (retval) == TARGET_EXPR
6766 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6767 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6768 TREE_OPERAND (retval, 0));
6770 maybe_warn_about_returning_address_of_local (retval);
6773 /* Actually copy the value returned into the appropriate location. */
6774 if (retval && retval != result)
6775 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6781 /* Returns nonzero if the pointer-type FROM can be converted to the
6782 pointer-type TO via a qualification conversion. If CONSTP is -1,
6783 then we return nonzero if the pointers are similar, and the
6784 cv-qualification signature of FROM is a proper subset of that of TO.
6786 If CONSTP is positive, then all outer pointers have been
6790 comp_ptr_ttypes_real (tree to, tree from, int constp)
6792 bool to_more_cv_qualified = false;
6794 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6796 if (TREE_CODE (to) != TREE_CODE (from))
6799 if (TREE_CODE (from) == OFFSET_TYPE
6800 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6801 TYPE_OFFSET_BASETYPE (to)))
6804 /* Const and volatile mean something different for function types,
6805 so the usual checks are not appropriate. */
6806 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6808 /* In Objective-C++, some types may have been 'volatilized' by
6809 the compiler for EH; when comparing them here, the volatile
6810 qualification must be ignored. */
6811 bool objc_quals_match = objc_type_quals_match (to, from);
6813 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6816 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6820 to_more_cv_qualified = true;
6824 constp &= TYPE_READONLY (to);
6827 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6828 return ((constp >= 0 || to_more_cv_qualified)
6829 && same_type_ignoring_top_level_qualifiers_p (to, from));
6833 /* When comparing, say, char ** to char const **, this function takes
6834 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6835 types to this function. */
6838 comp_ptr_ttypes (tree to, tree from)
6840 return comp_ptr_ttypes_real (to, from, 1);
6843 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6844 type or inheritance-related types, regardless of cv-quals. */
6847 ptr_reasonably_similar (tree to, tree from)
6849 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6851 /* Any target type is similar enough to void. */
6852 if (TREE_CODE (to) == VOID_TYPE
6853 || TREE_CODE (from) == VOID_TYPE)
6856 if (TREE_CODE (to) != TREE_CODE (from))
6859 if (TREE_CODE (from) == OFFSET_TYPE
6860 && comptypes (TYPE_OFFSET_BASETYPE (to),
6861 TYPE_OFFSET_BASETYPE (from),
6862 COMPARE_BASE | COMPARE_DERIVED))
6865 if (TREE_CODE (to) == VECTOR_TYPE
6866 && vector_types_convertible_p (to, from, false))
6869 if (TREE_CODE (to) == INTEGER_TYPE
6870 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6873 if (TREE_CODE (to) == FUNCTION_TYPE)
6876 if (TREE_CODE (to) != POINTER_TYPE)
6878 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6879 COMPARE_BASE | COMPARE_DERIVED);
6883 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6884 pointer-to-member types) are the same, ignoring cv-qualification at
6888 comp_ptr_ttypes_const (tree to, tree from)
6890 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6892 if (TREE_CODE (to) != TREE_CODE (from))
6895 if (TREE_CODE (from) == OFFSET_TYPE
6896 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6897 TYPE_OFFSET_BASETYPE (to)))
6900 if (TREE_CODE (to) != POINTER_TYPE)
6901 return same_type_ignoring_top_level_qualifiers_p (to, from);
6905 /* Returns the type qualifiers for this type, including the qualifiers on the
6906 elements for an array type. */
6909 cp_type_quals (tree type)
6911 type = strip_array_types (type);
6912 if (type == error_mark_node)
6913 return TYPE_UNQUALIFIED;
6914 return TYPE_QUALS (type);
6917 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6921 cp_type_readonly (tree type)
6923 type = strip_array_types (type);
6924 return TYPE_READONLY (type);
6927 /* Returns nonzero if the TYPE contains a mutable member. */
6930 cp_has_mutable_p (tree type)
6932 type = strip_array_types (type);
6934 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6937 /* Apply the TYPE_QUALS to the new DECL. */
6939 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6941 tree type = TREE_TYPE (decl);
6943 if (type == error_mark_node)
6946 if (TREE_CODE (type) == FUNCTION_TYPE
6947 && type_quals != TYPE_UNQUALIFIED)
6949 /* This was an error in C++98 (cv-qualifiers cannot be added to
6950 a function type), but DR 295 makes the code well-formed by
6951 dropping the extra qualifiers. */
6954 tree bad_type = build_qualified_type (type, type_quals);
6955 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6959 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6963 /* Avoid setting TREE_READONLY incorrectly. */
6964 if (/* If the object has a constructor, the constructor may modify
6966 TYPE_NEEDS_CONSTRUCTING (type)
6967 /* If the type isn't complete, we don't know yet if it will need
6969 || !COMPLETE_TYPE_P (type)
6970 /* If the type has a mutable component, that component might be
6972 || TYPE_HAS_MUTABLE_P (type))
6973 type_quals &= ~TYPE_QUAL_CONST;
6975 c_apply_type_quals_to_decl (type_quals, decl);
6978 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6979 exemplar types such that casting T1 to T2 is casting away constness
6980 if and only if there is no implicit conversion from T1 to T2. */
6983 casts_away_constness_r (tree *t1, tree *t2)
6988 /* [expr.const.cast]
6990 For multi-level pointer to members and multi-level mixed pointers
6991 and pointers to members (conv.qual), the "member" aspect of a
6992 pointer to member level is ignored when determining if a const
6993 cv-qualifier has been cast away. */
6994 /* [expr.const.cast]
6996 For two pointer types:
6998 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6999 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7002 casting from X1 to X2 casts away constness if, for a non-pointer
7003 type T there does not exist an implicit conversion (clause
7006 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7010 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7011 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7012 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7014 *t1 = cp_build_qualified_type (void_type_node,
7015 cp_type_quals (*t1));
7016 *t2 = cp_build_qualified_type (void_type_node,
7017 cp_type_quals (*t2));
7021 quals1 = cp_type_quals (*t1);
7022 quals2 = cp_type_quals (*t2);
7024 if (TYPE_PTRMEM_P (*t1))
7025 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7027 *t1 = TREE_TYPE (*t1);
7028 if (TYPE_PTRMEM_P (*t2))
7029 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7031 *t2 = TREE_TYPE (*t2);
7033 casts_away_constness_r (t1, t2);
7034 *t1 = build_pointer_type (*t1);
7035 *t2 = build_pointer_type (*t2);
7036 *t1 = cp_build_qualified_type (*t1, quals1);
7037 *t2 = cp_build_qualified_type (*t2, quals2);
7040 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7044 casts_away_constness (tree t1, tree t2)
7046 if (TREE_CODE (t2) == REFERENCE_TYPE)
7048 /* [expr.const.cast]
7050 Casting from an lvalue of type T1 to an lvalue of type T2
7051 using a reference cast casts away constness if a cast from an
7052 rvalue of type "pointer to T1" to the type "pointer to T2"
7053 casts away constness. */
7054 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7055 return casts_away_constness (build_pointer_type (t1),
7056 build_pointer_type (TREE_TYPE (t2)));
7059 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7060 /* [expr.const.cast]
7062 Casting from an rvalue of type "pointer to data member of X
7063 of type T1" to the type "pointer to data member of Y of type
7064 T2" casts away constness if a cast from an rvalue of type
7065 "pointer to T1" to the type "pointer to T2" casts away
7067 return casts_away_constness
7068 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7069 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7071 /* Casting away constness is only something that makes sense for
7072 pointer or reference types. */
7073 if (TREE_CODE (t1) != POINTER_TYPE
7074 || TREE_CODE (t2) != POINTER_TYPE)
7077 /* Top-level qualifiers don't matter. */
7078 t1 = TYPE_MAIN_VARIANT (t1);
7079 t2 = TYPE_MAIN_VARIANT (t2);
7080 casts_away_constness_r (&t1, &t2);
7081 if (!can_convert (t2, t1))
7087 /* If T is a REFERENCE_TYPE return the type to which T refers.
7088 Otherwise, return T itself. */
7091 non_reference (tree t)
7093 if (TREE_CODE (t) == REFERENCE_TYPE)
7099 /* Return nonzero if REF is an lvalue valid for this language;
7100 otherwise, print an error message and return zero. USE says
7101 how the lvalue is being used and so selects the error message. */
7104 lvalue_or_else (tree ref, enum lvalue_use use)
7106 int win = lvalue_p (ref);