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)
946 t1 = resolve_typename_type (t1, /*only_current_p=*/true);
948 if (TREE_CODE (t2) == TYPENAME_TYPE)
949 t2 = resolve_typename_type (t2, /*only_current_p=*/true);
951 if (TYPE_PTRMEMFUNC_P (t1))
952 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
953 if (TYPE_PTRMEMFUNC_P (t2))
954 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
956 /* Different classes of types can't be compatible. */
957 if (TREE_CODE (t1) != TREE_CODE (t2))
960 /* Qualifiers must match. For array types, we will check when we
961 recur on the array element types. */
962 if (TREE_CODE (t1) != ARRAY_TYPE
963 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
965 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
968 /* Allow for two different type nodes which have essentially the same
969 definition. Note that we already checked for equality of the type
970 qualifiers (just above). */
972 if (TREE_CODE (t1) != ARRAY_TYPE
973 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
976 /* Compare the types. Break out if they could be the same. */
977 switch (TREE_CODE (t1))
979 case TEMPLATE_TEMPLATE_PARM:
980 case BOUND_TEMPLATE_TEMPLATE_PARM:
981 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
982 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
983 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
984 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
986 if (!comp_template_parms
987 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
988 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
990 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
992 /* Don't check inheritance. */
993 strict = COMPARE_STRICT;
998 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
999 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1000 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1001 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1004 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1006 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1012 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1013 strict & ~COMPARE_REDECLARATION))
1015 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1019 case REFERENCE_TYPE:
1020 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2))
1022 /* fall through to checks for pointer types */
1025 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1026 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1027 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1033 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1035 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1040 /* Target types must match incl. qualifiers. */
1041 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1045 case TEMPLATE_TYPE_PARM:
1046 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1047 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1048 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1049 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1054 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1055 TYPENAME_TYPE_FULLNAME (t2)))
1057 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1061 case UNBOUND_CLASS_TEMPLATE:
1062 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1064 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1069 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1074 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1075 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1079 case TYPE_PACK_EXPANSION:
1080 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1081 PACK_EXPANSION_PATTERN (t2));
1087 /* If we get here, we know that from a target independent POV the
1088 types are the same. Make sure the target attributes are also
1090 return targetm.comp_type_attributes (t1, t2);
1093 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1094 is a bitwise-or of the COMPARE_* flags. */
1097 comptypes (tree t1, tree t2, int strict)
1099 if (strict == COMPARE_STRICT)
1104 if (t1 == error_mark_node || t2 == error_mark_node)
1107 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1108 /* At least one of the types requires structural equality, so
1109 perform a deep check. */
1110 return structural_comptypes (t1, t2, strict);
1112 #ifdef ENABLE_CHECKING
1113 if (USE_CANONICAL_TYPES)
1115 bool result = structural_comptypes (t1, t2, strict);
1117 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1118 /* The two types are structurally equivalent, but their
1119 canonical types were different. This is a failure of the
1120 canonical type propagation code.*/
1122 ("canonical types differ for identical types %T and %T",
1124 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1125 /* Two types are structurally different, but the canonical
1126 types are the same. This means we were over-eager in
1127 assigning canonical types. */
1129 ("same canonical type node for different types %T and %T",
1135 if (USE_CANONICAL_TYPES)
1136 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1139 return structural_comptypes (t1, t2, strict);
1141 else if (strict == COMPARE_STRUCTURAL)
1142 return structural_comptypes (t1, t2, COMPARE_STRICT);
1144 return structural_comptypes (t1, t2, strict);
1147 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1150 at_least_as_qualified_p (tree type1, tree type2)
1152 int q1 = cp_type_quals (type1);
1153 int q2 = cp_type_quals (type2);
1155 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1156 return (q1 & q2) == q2;
1159 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1160 more cv-qualified that TYPE1, and 0 otherwise. */
1163 comp_cv_qualification (tree type1, tree type2)
1165 int q1 = cp_type_quals (type1);
1166 int q2 = cp_type_quals (type2);
1171 if ((q1 & q2) == q2)
1173 else if ((q1 & q2) == q1)
1179 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1180 subset of the cv-qualification signature of TYPE2, and the types
1181 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1184 comp_cv_qual_signature (tree type1, tree type2)
1186 if (comp_ptr_ttypes_real (type2, type1, -1))
1188 else if (comp_ptr_ttypes_real (type1, type2, -1))
1194 /* Subroutines of `comptypes'. */
1196 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1197 equivalent in the sense that functions with those parameter types
1198 can have equivalent types. The two lists must be equivalent,
1199 element by element. */
1202 compparms (tree parms1, tree parms2)
1206 /* An unspecified parmlist matches any specified parmlist
1207 whose argument types don't need default promotions. */
1209 for (t1 = parms1, t2 = parms2;
1211 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1213 /* If one parmlist is shorter than the other,
1214 they fail to match. */
1217 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1224 /* Process a sizeof or alignof expression where the operand is a
1228 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1233 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1234 if (type == error_mark_node)
1235 return error_mark_node;
1237 type = non_reference (type);
1238 if (TREE_CODE (type) == METHOD_TYPE)
1240 if (complain && (pedantic || warn_pointer_arith))
1241 pedwarn ("invalid application of %qs to a member function",
1242 operator_name_info[(int) op].name);
1243 value = size_one_node;
1246 dependent_p = dependent_type_p (type);
1248 complete_type (type);
1250 /* VLA types will have a non-constant size. In the body of an
1251 uninstantiated template, we don't need to try to compute the
1252 value, because the sizeof expression is not an integral
1253 constant expression in that case. And, if we do try to
1254 compute the value, we'll likely end up with SAVE_EXPRs, which
1255 the template substitution machinery does not expect to see. */
1256 || (processing_template_decl
1257 && COMPLETE_TYPE_P (type)
1258 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1260 value = build_min (op, size_type_node, type);
1261 TREE_READONLY (value) = 1;
1265 return c_sizeof_or_alignof_type (complete_type (type),
1270 /* Process a sizeof expression where the operand is an expression. */
1273 cxx_sizeof_expr (tree e)
1275 if (e == error_mark_node)
1276 return error_mark_node;
1278 if (processing_template_decl)
1280 e = build_min (SIZEOF_EXPR, size_type_node, e);
1281 TREE_SIDE_EFFECTS (e) = 0;
1282 TREE_READONLY (e) = 1;
1287 if (TREE_CODE (e) == COMPONENT_REF
1288 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1289 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1291 error ("invalid application of %<sizeof%> to a bit-field");
1294 else if (is_overloaded_fn (e))
1296 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1300 else if (type_unknown_p (e))
1302 cxx_incomplete_type_error (e, TREE_TYPE (e));
1308 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1311 /* Implement the __alignof keyword: Return the minimum required
1312 alignment of E, measured in bytes. For VAR_DECL's and
1313 FIELD_DECL's return DECL_ALIGN (which can be set from an
1314 "aligned" __attribute__ specification). */
1317 cxx_alignof_expr (tree e)
1321 if (e == error_mark_node)
1322 return error_mark_node;
1324 if (processing_template_decl)
1326 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1327 TREE_SIDE_EFFECTS (e) = 0;
1328 TREE_READONLY (e) = 1;
1333 if (TREE_CODE (e) == VAR_DECL)
1334 t = size_int (DECL_ALIGN_UNIT (e));
1335 else if (TREE_CODE (e) == COMPONENT_REF
1336 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1337 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1339 error ("invalid application of %<__alignof%> to a bit-field");
1342 else if (TREE_CODE (e) == COMPONENT_REF
1343 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1344 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1345 else if (is_overloaded_fn (e))
1347 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1349 if (TREE_CODE (e) == FUNCTION_DECL)
1350 t = size_int (DECL_ALIGN_UNIT (e));
1354 else if (type_unknown_p (e))
1356 cxx_incomplete_type_error (e, TREE_TYPE (e));
1360 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1362 return fold_convert (size_type_node, t);
1365 /* Process a sizeof or alignof expression E with code OP where the operand
1366 is an expression. */
1369 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1371 if (op == SIZEOF_EXPR)
1372 return cxx_sizeof_expr (e);
1374 return cxx_alignof_expr (e);
1377 /* EXPR is being used in a context that is not a function call.
1382 The expression can be used only as the left-hand operand of a
1383 member function call.
1385 [expr.mptr.operator]
1387 If the result of .* or ->* is a function, then that result can be
1388 used only as the operand for the function call operator ().
1390 by issuing an error message if appropriate. Returns true iff EXPR
1391 violates these rules. */
1394 invalid_nonstatic_memfn_p (tree expr)
1396 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1398 error ("invalid use of non-static member function");
1404 /* If EXP is a reference to a bitfield, and the type of EXP does not
1405 match the declared type of the bitfield, return the declared type
1406 of the bitfield. Otherwise, return NULL_TREE. */
1409 is_bitfield_expr_with_lowered_type (tree exp)
1411 switch (TREE_CODE (exp))
1414 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1416 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1419 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1423 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1429 field = TREE_OPERAND (exp, 1);
1430 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1432 if (same_type_ignoring_top_level_qualifiers_p
1433 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1435 return DECL_BIT_FIELD_TYPE (field);
1443 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1444 bitfield with a lowered type, the type of EXP is returned, rather
1448 unlowered_expr_type (tree exp)
1452 type = is_bitfield_expr_with_lowered_type (exp);
1454 type = TREE_TYPE (exp);
1459 /* Perform the conversions in [expr] that apply when an lvalue appears
1460 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1461 function-to-pointer conversions. In addition, manifest constants
1462 are replaced by their values, and bitfield references are converted
1463 to their declared types.
1465 Although the returned value is being used as an rvalue, this
1466 function does not wrap the returned expression in a
1467 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1468 that the return value is no longer an lvalue. */
1471 decay_conversion (tree exp)
1474 enum tree_code code;
1476 type = TREE_TYPE (exp);
1477 if (type == error_mark_node)
1478 return error_mark_node;
1480 if (type_unknown_p (exp))
1482 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1483 return error_mark_node;
1486 exp = decl_constant_value (exp);
1487 if (error_operand_p (exp))
1488 return error_mark_node;
1490 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1491 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1492 code = TREE_CODE (type);
1493 if (code == VOID_TYPE)
1495 error ("void value not ignored as it ought to be");
1496 return error_mark_node;
1498 if (invalid_nonstatic_memfn_p (exp))
1499 return error_mark_node;
1500 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1501 return build_unary_op (ADDR_EXPR, exp, 0);
1502 if (code == ARRAY_TYPE)
1507 if (TREE_CODE (exp) == INDIRECT_REF)
1508 return build_nop (build_pointer_type (TREE_TYPE (type)),
1509 TREE_OPERAND (exp, 0));
1511 if (TREE_CODE (exp) == COMPOUND_EXPR)
1513 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1514 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1515 TREE_OPERAND (exp, 0), op1);
1519 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1521 error ("invalid use of non-lvalue array");
1522 return error_mark_node;
1525 ptrtype = build_pointer_type (TREE_TYPE (type));
1527 if (TREE_CODE (exp) == VAR_DECL)
1529 if (!cxx_mark_addressable (exp))
1530 return error_mark_node;
1531 adr = build_nop (ptrtype, build_address (exp));
1534 /* This way is better for a COMPONENT_REF since it can
1535 simplify the offset for a component. */
1536 adr = build_unary_op (ADDR_EXPR, exp, 1);
1537 return cp_convert (ptrtype, adr);
1540 /* If a bitfield is used in a context where integral promotion
1541 applies, then the caller is expected to have used
1542 default_conversion. That function promotes bitfields correctly
1543 before calling this function. At this point, if we have a
1544 bitfield referenced, we may assume that is not subject to
1545 promotion, and that, therefore, the type of the resulting rvalue
1546 is the declared type of the bitfield. */
1547 exp = convert_bitfield_to_declared_type (exp);
1549 /* We do not call rvalue() here because we do not want to wrap EXP
1550 in a NON_LVALUE_EXPR. */
1554 Non-class rvalues always have cv-unqualified types. */
1555 type = TREE_TYPE (exp);
1556 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1557 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1562 /* Perform prepatory conversions, as part of the "usual arithmetic
1563 conversions". In particular, as per [expr]:
1565 Whenever an lvalue expression appears as an operand of an
1566 operator that expects the rvalue for that operand, the
1567 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1568 standard conversions are applied to convert the expression to an
1571 In addition, we perform integral promotions here, as those are
1572 applied to both operands to a binary operator before determining
1573 what additional conversions should apply. */
1576 default_conversion (tree exp)
1578 /* Perform the integral promotions first so that bitfield
1579 expressions (which may promote to "int", even if the bitfield is
1580 declared "unsigned") are promoted correctly. */
1581 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1582 exp = perform_integral_promotions (exp);
1583 /* Perform the other conversions. */
1584 exp = decay_conversion (exp);
1589 /* EXPR is an expression with an integral or enumeration type.
1590 Perform the integral promotions in [conv.prom], and return the
1594 perform_integral_promotions (tree expr)
1601 If the bitfield has an enumerated type, it is treated as any
1602 other value of that type for promotion purposes. */
1603 type = is_bitfield_expr_with_lowered_type (expr);
1604 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1605 type = TREE_TYPE (expr);
1606 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1607 promoted_type = type_promotes_to (type);
1608 if (type != promoted_type)
1609 expr = cp_convert (promoted_type, expr);
1613 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1617 inline_conversion (tree exp)
1619 if (TREE_CODE (exp) == FUNCTION_DECL)
1620 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1625 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1626 decay_conversion to one. */
1629 string_conv_p (tree totype, tree exp, int warn)
1633 if (TREE_CODE (totype) != POINTER_TYPE)
1636 t = TREE_TYPE (totype);
1637 if (!same_type_p (t, char_type_node)
1638 && !same_type_p (t, wchar_type_node))
1641 if (TREE_CODE (exp) == STRING_CST)
1643 /* Make sure that we don't try to convert between char and wchar_t. */
1644 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1649 /* Is this a string constant which has decayed to 'const char *'? */
1650 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1651 if (!same_type_p (TREE_TYPE (exp), t))
1654 if (TREE_CODE (exp) != ADDR_EXPR
1655 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1659 /* This warning is not very useful, as it complains about printf. */
1661 warning (OPT_Wwrite_strings,
1662 "deprecated conversion from string constant to %qT",
1668 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1669 can, for example, use as an lvalue. This code used to be in
1670 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1671 expressions, where we're dealing with aggregates. But now it's again only
1672 called from unary_complex_lvalue. The case (in particular) that led to
1673 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1677 rationalize_conditional_expr (enum tree_code code, tree t)
1679 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1680 the first operand is always the one to be used if both operands
1681 are equal, so we know what conditional expression this used to be. */
1682 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1684 tree op0 = TREE_OPERAND (t, 0);
1685 tree op1 = TREE_OPERAND (t, 1);
1687 /* The following code is incorrect if either operand side-effects. */
1688 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1689 && !TREE_SIDE_EFFECTS (op1));
1691 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1692 ? LE_EXPR : GE_EXPR),
1693 op0, TREE_CODE (op0),
1694 op1, TREE_CODE (op1),
1695 /*overloaded_p=*/NULL),
1696 build_unary_op (code, op0, 0),
1697 build_unary_op (code, op1, 0));
1701 build_conditional_expr (TREE_OPERAND (t, 0),
1702 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1703 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1706 /* Given the TYPE of an anonymous union field inside T, return the
1707 FIELD_DECL for the field. If not found return NULL_TREE. Because
1708 anonymous unions can nest, we must also search all anonymous unions
1709 that are directly reachable. */
1712 lookup_anon_field (tree t, tree type)
1716 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1718 if (TREE_STATIC (field))
1720 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1723 /* If we find it directly, return the field. */
1724 if (DECL_NAME (field) == NULL_TREE
1725 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1730 /* Otherwise, it could be nested, search harder. */
1731 if (DECL_NAME (field) == NULL_TREE
1732 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1734 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1742 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1743 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1744 non-NULL, it indicates the path to the base used to name MEMBER.
1745 If PRESERVE_REFERENCE is true, the expression returned will have
1746 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1747 returned will have the type referred to by the reference.
1749 This function does not perform access control; that is either done
1750 earlier by the parser when the name of MEMBER is resolved to MEMBER
1751 itself, or later when overload resolution selects one of the
1752 functions indicated by MEMBER. */
1755 build_class_member_access_expr (tree object, tree member,
1756 tree access_path, bool preserve_reference)
1760 tree result = NULL_TREE;
1762 if (error_operand_p (object) || error_operand_p (member))
1763 return error_mark_node;
1765 gcc_assert (DECL_P (member) || BASELINK_P (member));
1769 The type of the first expression shall be "class object" (of a
1771 object_type = TREE_TYPE (object);
1772 if (!currently_open_class (object_type)
1773 && !complete_type_or_else (object_type, object))
1774 return error_mark_node;
1775 if (!CLASS_TYPE_P (object_type))
1777 error ("request for member %qD in %qE, which is of non-class type %qT",
1778 member, object, object_type);
1779 return error_mark_node;
1782 /* The standard does not seem to actually say that MEMBER must be a
1783 member of OBJECT_TYPE. However, that is clearly what is
1785 if (DECL_P (member))
1787 member_scope = DECL_CLASS_CONTEXT (member);
1789 if (TREE_DEPRECATED (member))
1790 warn_deprecated_use (member);
1793 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1794 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1795 presently be the anonymous union. Go outwards until we find a
1796 type related to OBJECT_TYPE. */
1797 while (ANON_AGGR_TYPE_P (member_scope)
1798 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1800 member_scope = TYPE_CONTEXT (member_scope);
1801 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1803 if (TREE_CODE (member) == FIELD_DECL)
1804 error ("invalid use of nonstatic data member %qE", member);
1806 error ("%qD is not a member of %qT", member, object_type);
1807 return error_mark_node;
1810 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1811 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1812 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1814 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1816 object = build_indirect_ref (temp, NULL);
1819 /* In [expr.ref], there is an explicit list of the valid choices for
1820 MEMBER. We check for each of those cases here. */
1821 if (TREE_CODE (member) == VAR_DECL)
1823 /* A static data member. */
1825 /* If OBJECT has side-effects, they are supposed to occur. */
1826 if (TREE_SIDE_EFFECTS (object))
1827 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1829 else if (TREE_CODE (member) == FIELD_DECL)
1831 /* A non-static data member. */
1836 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1837 && integer_zerop (TREE_OPERAND (object, 0)));
1839 /* Convert OBJECT to the type of MEMBER. */
1840 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1841 TYPE_MAIN_VARIANT (member_scope)))
1846 binfo = lookup_base (access_path ? access_path : object_type,
1847 member_scope, ba_unique, &kind);
1848 if (binfo == error_mark_node)
1849 return error_mark_node;
1851 /* It is invalid to try to get to a virtual base of a
1852 NULL object. The most common cause is invalid use of
1854 if (null_object_p && kind == bk_via_virtual)
1856 error ("invalid access to non-static data member %qD of "
1859 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1860 return error_mark_node;
1863 /* Convert to the base. */
1864 object = build_base_path (PLUS_EXPR, object, binfo,
1866 /* If we found the base successfully then we should be able
1867 to convert to it successfully. */
1868 gcc_assert (object != error_mark_node);
1871 /* Complain about other invalid uses of offsetof, even though they will
1872 give the right answer. Note that we complain whether or not they
1873 actually used the offsetof macro, since there's no way to know at this
1874 point. So we just give a warning, instead of a pedwarn. */
1875 /* Do not produce this warning for base class field references, because
1876 we know for a fact that didn't come from offsetof. This does occur
1877 in various testsuite cases where a null object is passed where a
1878 vtable access is required. */
1879 if (null_object_p && warn_invalid_offsetof
1880 && CLASSTYPE_NON_POD_P (object_type)
1881 && !DECL_FIELD_IS_BASE (member)
1882 && !skip_evaluation)
1884 warning (0, "invalid access to non-static data member %qD of NULL object",
1886 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1889 /* If MEMBER is from an anonymous aggregate, we have converted
1890 OBJECT so that it refers to the class containing the
1891 anonymous union. Generate a reference to the anonymous union
1892 itself, and recur to find MEMBER. */
1893 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1894 /* When this code is called from build_field_call, the
1895 object already has the type of the anonymous union.
1896 That is because the COMPONENT_REF was already
1897 constructed, and was then disassembled before calling
1898 build_field_call. After the function-call code is
1899 cleaned up, this waste can be eliminated. */
1900 && (!same_type_ignoring_top_level_qualifiers_p
1901 (TREE_TYPE (object), DECL_CONTEXT (member))))
1903 tree anonymous_union;
1905 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1906 DECL_CONTEXT (member));
1907 object = build_class_member_access_expr (object,
1909 /*access_path=*/NULL_TREE,
1910 preserve_reference);
1913 /* Compute the type of the field, as described in [expr.ref]. */
1914 type_quals = TYPE_UNQUALIFIED;
1915 member_type = TREE_TYPE (member);
1916 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1918 type_quals = (cp_type_quals (member_type)
1919 | cp_type_quals (object_type));
1921 /* A field is const (volatile) if the enclosing object, or the
1922 field itself, is const (volatile). But, a mutable field is
1923 not const, even within a const object. */
1924 if (DECL_MUTABLE_P (member))
1925 type_quals &= ~TYPE_QUAL_CONST;
1926 member_type = cp_build_qualified_type (member_type, type_quals);
1929 result = build3 (COMPONENT_REF, member_type, object, member,
1931 result = fold_if_not_in_template (result);
1933 /* Mark the expression const or volatile, as appropriate. Even
1934 though we've dealt with the type above, we still have to mark the
1935 expression itself. */
1936 if (type_quals & TYPE_QUAL_CONST)
1937 TREE_READONLY (result) = 1;
1938 if (type_quals & TYPE_QUAL_VOLATILE)
1939 TREE_THIS_VOLATILE (result) = 1;
1941 else if (BASELINK_P (member))
1943 /* The member is a (possibly overloaded) member function. */
1947 /* If the MEMBER is exactly one static member function, then we
1948 know the type of the expression. Otherwise, we must wait
1949 until overload resolution has been performed. */
1950 functions = BASELINK_FUNCTIONS (member);
1951 if (TREE_CODE (functions) == FUNCTION_DECL
1952 && DECL_STATIC_FUNCTION_P (functions))
1953 type = TREE_TYPE (functions);
1955 type = unknown_type_node;
1956 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1957 base. That will happen when the function is called. */
1958 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1960 else if (TREE_CODE (member) == CONST_DECL)
1962 /* The member is an enumerator. */
1964 /* If OBJECT has side-effects, they are supposed to occur. */
1965 if (TREE_SIDE_EFFECTS (object))
1966 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1971 error ("invalid use of %qD", member);
1972 return error_mark_node;
1975 if (!preserve_reference)
1978 If E2 is declared to have type "reference to T", then ... the
1979 type of E1.E2 is T. */
1980 result = convert_from_reference (result);
1985 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1986 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1989 lookup_destructor (tree object, tree scope, tree dtor_name)
1991 tree object_type = TREE_TYPE (object);
1992 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1995 if (scope && !check_dtor_name (scope, dtor_type))
1997 error ("qualified type %qT does not match destructor name ~%qT",
1999 return error_mark_node;
2001 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2003 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2004 TYPE_MAIN_VARIANT (object_type), dtor_type);
2005 return error_mark_node;
2007 expr = lookup_member (dtor_type, complete_dtor_identifier,
2008 /*protect=*/1, /*want_type=*/false);
2009 expr = (adjust_result_of_qualified_name_lookup
2010 (expr, dtor_type, object_type));
2014 /* An expression of the form "A::template B" has been resolved to
2015 DECL. Issue a diagnostic if B is not a template or template
2019 check_template_keyword (tree decl)
2021 /* The standard says:
2025 If a name prefixed by the keyword template is not a member
2026 template, the program is ill-formed.
2028 DR 228 removed the restriction that the template be a member
2031 DR 96, if accepted would add the further restriction that explicit
2032 template arguments must be provided if the template keyword is
2033 used, but, as of 2005-10-16, that DR is still in "drafting". If
2034 this DR is accepted, then the semantic checks here can be
2035 simplified, as the entity named must in fact be a template
2036 specialization, rather than, as at present, a set of overloaded
2037 functions containing at least one template function. */
2038 if (TREE_CODE (decl) != TEMPLATE_DECL
2039 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2041 if (!is_overloaded_fn (decl))
2042 pedwarn ("%qD is not a template", decl);
2047 if (BASELINK_P (fns))
2048 fns = BASELINK_FUNCTIONS (fns);
2051 tree fn = OVL_CURRENT (fns);
2052 if (TREE_CODE (fn) == TEMPLATE_DECL
2053 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2055 if (TREE_CODE (fn) == FUNCTION_DECL
2056 && DECL_USE_TEMPLATE (fn)
2057 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2059 fns = OVL_NEXT (fns);
2062 pedwarn ("%qD is not a template", decl);
2067 /* This function is called by the parser to process a class member
2068 access expression of the form OBJECT.NAME. NAME is a node used by
2069 the parser to represent a name; it is not yet a DECL. It may,
2070 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2071 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2072 there is no reason to do the lookup twice, so the parser keeps the
2073 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2074 be a template via the use of the "A::template B" syntax. */
2077 finish_class_member_access_expr (tree object, tree name, bool template_p)
2082 tree access_path = NULL_TREE;
2083 tree orig_object = object;
2084 tree orig_name = name;
2086 if (object == error_mark_node || name == error_mark_node)
2087 return error_mark_node;
2089 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2090 if (!objc_is_public (object, name))
2091 return error_mark_node;
2093 object_type = TREE_TYPE (object);
2095 if (processing_template_decl)
2097 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2098 dependent_type_p (object_type)
2099 /* If NAME is just an IDENTIFIER_NODE, then the expression
2101 || TREE_CODE (object) == IDENTIFIER_NODE
2102 /* If NAME is "f<args>", where either 'f' or 'args' is
2103 dependent, then the expression is dependent. */
2104 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2105 && dependent_template_id_p (TREE_OPERAND (name, 0),
2106 TREE_OPERAND (name, 1)))
2107 /* If NAME is "T::X" where "T" is dependent, then the
2108 expression is dependent. */
2109 || (TREE_CODE (name) == SCOPE_REF
2110 && TYPE_P (TREE_OPERAND (name, 0))
2111 && dependent_type_p (TREE_OPERAND (name, 0))))
2112 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2113 object = build_non_dependent_expr (object);
2118 The type of the first expression shall be "class object" (of a
2120 if (!currently_open_class (object_type)
2121 && !complete_type_or_else (object_type, object))
2122 return error_mark_node;
2123 if (!CLASS_TYPE_P (object_type))
2125 error ("request for member %qD in %qE, which is of non-class type %qT",
2126 name, object, object_type);
2127 return error_mark_node;
2130 if (BASELINK_P (name))
2131 /* A member function that has already been looked up. */
2135 bool is_template_id = false;
2136 tree template_args = NULL_TREE;
2139 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2141 is_template_id = true;
2142 template_args = TREE_OPERAND (name, 1);
2143 name = TREE_OPERAND (name, 0);
2145 if (TREE_CODE (name) == OVERLOAD)
2146 name = DECL_NAME (get_first_fn (name));
2147 else if (DECL_P (name))
2148 name = DECL_NAME (name);
2151 if (TREE_CODE (name) == SCOPE_REF)
2153 /* A qualified name. The qualifying class or namespace `S'
2154 has already been looked up; it is either a TYPE or a
2156 scope = TREE_OPERAND (name, 0);
2157 name = TREE_OPERAND (name, 1);
2159 /* If SCOPE is a namespace, then the qualified name does not
2160 name a member of OBJECT_TYPE. */
2161 if (TREE_CODE (scope) == NAMESPACE_DECL)
2163 error ("%<%D::%D%> is not a member of %qT",
2164 scope, name, object_type);
2165 return error_mark_node;
2168 gcc_assert (CLASS_TYPE_P (scope));
2169 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2170 || TREE_CODE (name) == BIT_NOT_EXPR);
2172 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2173 access_path = lookup_base (object_type, scope, ba_check, NULL);
2174 if (access_path == error_mark_node)
2175 return error_mark_node;
2178 error ("%qT is not a base of %qT", scope, object_type);
2179 return error_mark_node;
2185 access_path = object_type;
2188 if (TREE_CODE (name) == BIT_NOT_EXPR)
2189 member = lookup_destructor (object, scope, name);
2192 /* Look up the member. */
2193 member = lookup_member (access_path, name, /*protect=*/1,
2194 /*want_type=*/false);
2195 if (member == NULL_TREE)
2197 error ("%qD has no member named %qE", object_type, name);
2198 return error_mark_node;
2200 if (member == error_mark_node)
2201 return error_mark_node;
2206 tree template = member;
2208 if (BASELINK_P (template))
2209 template = lookup_template_function (template, template_args);
2212 error ("%qD is not a member template function", name);
2213 return error_mark_node;
2218 if (TREE_DEPRECATED (member))
2219 warn_deprecated_use (member);
2222 check_template_keyword (member);
2224 expr = build_class_member_access_expr (object, member, access_path,
2225 /*preserve_reference=*/false);
2226 if (processing_template_decl && expr != error_mark_node)
2228 if (BASELINK_P (member))
2230 if (TREE_CODE (orig_name) == SCOPE_REF)
2231 BASELINK_QUALIFIED_P (member) = 1;
2234 return build_min_non_dep (COMPONENT_REF, expr,
2235 orig_object, orig_name,
2242 /* Return an expression for the MEMBER_NAME field in the internal
2243 representation of PTRMEM, a pointer-to-member function. (Each
2244 pointer-to-member function type gets its own RECORD_TYPE so it is
2245 more convenient to access the fields by name than by FIELD_DECL.)
2246 This routine converts the NAME to a FIELD_DECL and then creates the
2247 node for the complete expression. */
2250 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2256 /* This code is a stripped down version of
2257 build_class_member_access_expr. It does not work to use that
2258 routine directly because it expects the object to be of class
2260 ptrmem_type = TREE_TYPE (ptrmem);
2261 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2262 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2263 /*want_type=*/false);
2264 member_type = cp_build_qualified_type (TREE_TYPE (member),
2265 cp_type_quals (ptrmem_type));
2266 return fold_build3 (COMPONENT_REF, member_type,
2267 ptrmem, member, NULL_TREE);
2270 /* Given an expression PTR for a pointer, return an expression
2271 for the value pointed to.
2272 ERRORSTRING is the name of the operator to appear in error messages.
2274 This function may need to overload OPERATOR_FNNAME.
2275 Must also handle REFERENCE_TYPEs for C++. */
2278 build_x_indirect_ref (tree expr, const char *errorstring)
2280 tree orig_expr = expr;
2283 if (processing_template_decl)
2285 if (type_dependent_expression_p (expr))
2286 return build_min_nt (INDIRECT_REF, expr);
2287 expr = build_non_dependent_expr (expr);
2290 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2291 NULL_TREE, /*overloaded_p=*/NULL);
2293 rval = build_indirect_ref (expr, errorstring);
2295 if (processing_template_decl && rval != error_mark_node)
2296 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2302 build_indirect_ref (tree ptr, const char *errorstring)
2306 if (ptr == error_mark_node)
2307 return error_mark_node;
2309 if (ptr == current_class_ptr)
2310 return current_class_ref;
2312 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2313 ? ptr : decay_conversion (ptr));
2314 type = TREE_TYPE (pointer);
2316 if (POINTER_TYPE_P (type))
2320 If the type of the expression is "pointer to T," the type
2321 of the result is "T."
2323 We must use the canonical variant because certain parts of
2324 the back end, like fold, do pointer comparisons between
2326 tree t = canonical_type_variant (TREE_TYPE (type));
2328 if (TREE_CODE (ptr) == CONVERT_EXPR
2329 || TREE_CODE (ptr) == NOP_EXPR
2330 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2332 /* If a warning is issued, mark it to avoid duplicates from
2333 the backend. This only needs to be done at
2334 warn_strict_aliasing > 2. */
2335 if (warn_strict_aliasing > 2)
2336 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2337 type, TREE_OPERAND (ptr, 0)))
2338 TREE_NO_WARNING (ptr) = 1;
2341 if (VOID_TYPE_P (t))
2343 /* A pointer to incomplete type (other than cv void) can be
2344 dereferenced [expr.unary.op]/1 */
2345 error ("%qT is not a pointer-to-object type", type);
2346 return error_mark_node;
2348 else if (TREE_CODE (pointer) == ADDR_EXPR
2349 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2350 /* The POINTER was something like `&x'. We simplify `*&x' to
2352 return TREE_OPERAND (pointer, 0);
2355 tree ref = build1 (INDIRECT_REF, t, pointer);
2357 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2358 so that we get the proper error message if the result is used
2359 to assign to. Also, &* is supposed to be a no-op. */
2360 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2361 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2362 TREE_SIDE_EFFECTS (ref)
2363 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2367 /* `pointer' won't be an error_mark_node if we were given a
2368 pointer to member, so it's cool to check for this here. */
2369 else if (TYPE_PTR_TO_MEMBER_P (type))
2370 error ("invalid use of %qs on pointer to member", errorstring);
2371 else if (pointer != error_mark_node)
2374 error ("invalid type argument of %qs", errorstring);
2376 error ("invalid type argument");
2378 return error_mark_node;
2381 /* This handles expressions of the form "a[i]", which denotes
2384 This is logically equivalent in C to *(a+i), but we may do it differently.
2385 If A is a variable or a member, we generate a primitive ARRAY_REF.
2386 This avoids forcing the array out of registers, and can work on
2387 arrays that are not lvalues (for example, members of structures returned
2390 If INDEX is of some user-defined type, it must be converted to
2391 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2392 will inherit the type of the array, which will be some pointer type. */
2395 build_array_ref (tree array, tree idx)
2399 error ("subscript missing in array reference");
2400 return error_mark_node;
2403 if (TREE_TYPE (array) == error_mark_node
2404 || TREE_TYPE (idx) == error_mark_node)
2405 return error_mark_node;
2407 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2409 switch (TREE_CODE (array))
2413 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2414 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2415 TREE_OPERAND (array, 0), value);
2419 return build_conditional_expr
2420 (TREE_OPERAND (array, 0),
2421 build_array_ref (TREE_OPERAND (array, 1), idx),
2422 build_array_ref (TREE_OPERAND (array, 2), idx));
2428 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2432 warn_array_subscript_with_type_char (idx);
2434 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2436 error ("array subscript is not an integer");
2437 return error_mark_node;
2440 /* Apply integral promotions *after* noticing character types.
2441 (It is unclear why we do these promotions -- the standard
2442 does not say that we should. In fact, the natural thing would
2443 seem to be to convert IDX to ptrdiff_t; we're performing
2444 pointer arithmetic.) */
2445 idx = perform_integral_promotions (idx);
2447 /* An array that is indexed by a non-constant
2448 cannot be stored in a register; we must be able to do
2449 address arithmetic on its address.
2450 Likewise an array of elements of variable size. */
2451 if (TREE_CODE (idx) != INTEGER_CST
2452 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2453 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2456 if (!cxx_mark_addressable (array))
2457 return error_mark_node;
2460 /* An array that is indexed by a constant value which is not within
2461 the array bounds cannot be stored in a register either; because we
2462 would get a crash in store_bit_field/extract_bit_field when trying
2463 to access a non-existent part of the register. */
2464 if (TREE_CODE (idx) == INTEGER_CST
2465 && TYPE_DOMAIN (TREE_TYPE (array))
2466 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2468 if (!cxx_mark_addressable (array))
2469 return error_mark_node;
2472 if (pedantic && !lvalue_p (array))
2473 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2475 /* Note in C++ it is valid to subscript a `register' array, since
2476 it is valid to take the address of something with that
2477 storage specification. */
2481 while (TREE_CODE (foo) == COMPONENT_REF)
2482 foo = TREE_OPERAND (foo, 0);
2483 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2484 warning (OPT_Wextra, "subscripting array declared %<register%>");
2487 type = TREE_TYPE (TREE_TYPE (array));
2488 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2489 /* Array ref is const/volatile if the array elements are
2490 or if the array is.. */
2491 TREE_READONLY (rval)
2492 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2493 TREE_SIDE_EFFECTS (rval)
2494 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2495 TREE_THIS_VOLATILE (rval)
2496 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2497 return require_complete_type (fold_if_not_in_template (rval));
2501 tree ar = default_conversion (array);
2502 tree ind = default_conversion (idx);
2504 /* Put the integer in IND to simplify error checking. */
2505 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2512 if (ar == error_mark_node)
2515 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2517 error ("subscripted value is neither array nor pointer");
2518 return error_mark_node;
2520 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2522 error ("array subscript is not an integer");
2523 return error_mark_node;
2526 warn_array_subscript_with_type_char (idx);
2528 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2533 /* Resolve a pointer to member function. INSTANCE is the object
2534 instance to use, if the member points to a virtual member.
2536 This used to avoid checking for virtual functions if basetype
2537 has no virtual functions, according to an earlier ANSI draft.
2538 With the final ISO C++ rules, such an optimization is
2539 incorrect: A pointer to a derived member can be static_cast
2540 to pointer-to-base-member, as long as the dynamic object
2541 later has the right member. */
2544 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2546 if (TREE_CODE (function) == OFFSET_REF)
2547 function = TREE_OPERAND (function, 1);
2549 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2551 tree idx, delta, e1, e2, e3, vtbl, basetype;
2552 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2554 tree instance_ptr = *instance_ptrptr;
2555 tree instance_save_expr = 0;
2556 if (instance_ptr == error_mark_node)
2558 if (TREE_CODE (function) == PTRMEM_CST)
2560 /* Extracting the function address from a pmf is only
2561 allowed with -Wno-pmf-conversions. It only works for
2563 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2564 e1 = convert (fntype, e1);
2569 error ("object missing in use of %qE", function);
2570 return error_mark_node;
2574 if (TREE_SIDE_EFFECTS (instance_ptr))
2575 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2577 if (TREE_SIDE_EFFECTS (function))
2578 function = save_expr (function);
2580 /* Start by extracting all the information from the PMF itself. */
2581 e3 = pfn_from_ptrmemfunc (function);
2582 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2583 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2584 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2586 case ptrmemfunc_vbit_in_pfn:
2587 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2588 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2591 case ptrmemfunc_vbit_in_delta:
2592 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2593 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2600 /* Convert down to the right base before using the instance. A
2601 special case is that in a pointer to member of class C, C may
2602 be incomplete. In that case, the function will of course be
2603 a member of C, and no conversion is required. In fact,
2604 lookup_base will fail in that case, because incomplete
2605 classes do not have BINFOs. */
2606 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2607 if (!same_type_ignoring_top_level_qualifiers_p
2608 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2610 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2611 basetype, ba_check, NULL);
2612 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2614 if (instance_ptr == error_mark_node)
2615 return error_mark_node;
2617 /* ...and then the delta in the PMF. */
2618 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
2619 instance_ptr, fold_convert (sizetype, delta));
2621 /* Hand back the adjusted 'this' argument to our caller. */
2622 *instance_ptrptr = instance_ptr;
2624 /* Next extract the vtable pointer from the object. */
2625 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2627 vtbl = build_indirect_ref (vtbl, NULL);
2629 /* Finally, extract the function pointer from the vtable. */
2630 e2 = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
2631 fold_convert (sizetype, idx));
2632 e2 = build_indirect_ref (e2, NULL);
2633 TREE_CONSTANT (e2) = 1;
2634 TREE_INVARIANT (e2) = 1;
2636 /* When using function descriptors, the address of the
2637 vtable entry is treated as a function pointer. */
2638 if (TARGET_VTABLE_USES_DESCRIPTORS)
2639 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2640 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2642 TREE_TYPE (e2) = TREE_TYPE (e3);
2643 e1 = build_conditional_expr (e1, e2, e3);
2645 /* Make sure this doesn't get evaluated first inside one of the
2646 branches of the COND_EXPR. */
2647 if (instance_save_expr)
2648 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2649 instance_save_expr, e1);
2657 build_function_call (tree function, tree params)
2659 tree fntype, fndecl;
2660 tree name = NULL_TREE;
2662 tree original = function;
2663 int nargs, parm_types_len;
2667 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2668 expressions, like those used for ObjC messenger dispatches. */
2669 function = objc_rewrite_function_call (function, params);
2671 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2672 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2673 if (TREE_CODE (function) == NOP_EXPR
2674 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2675 function = TREE_OPERAND (function, 0);
2677 if (TREE_CODE (function) == FUNCTION_DECL)
2679 name = DECL_NAME (function);
2681 mark_used (function);
2684 /* Convert anything with function type to a pointer-to-function. */
2685 if (pedantic && DECL_MAIN_P (function))
2686 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2688 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2689 (because calling an inline function does not mean the function
2690 needs to be separately compiled). */
2692 if (DECL_INLINE (function))
2693 function = inline_conversion (function);
2695 function = build_addr_func (function);
2701 function = build_addr_func (function);
2704 if (function == error_mark_node)
2705 return error_mark_node;
2707 fntype = TREE_TYPE (function);
2709 if (TYPE_PTRMEMFUNC_P (fntype))
2711 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2712 "function in %<%E (...)%>",
2714 return error_mark_node;
2717 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2718 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2720 if (!((TREE_CODE (fntype) == POINTER_TYPE
2721 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2723 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2725 error ("%qE cannot be used as a function", original);
2726 return error_mark_node;
2729 /* fntype now gets the type of function pointed to. */
2730 fntype = TREE_TYPE (fntype);
2731 parm_types = TYPE_ARG_TYPES (fntype);
2733 /* Allocate storage for converted arguments. */
2734 parm_types_len = list_length (parm_types);
2735 nargs = list_length (params);
2736 if (parm_types_len > nargs)
2737 nargs = parm_types_len;
2738 argarray = (tree *) alloca (nargs * sizeof (tree));
2740 /* Convert the parameters to the types declared in the
2741 function prototype, or apply default promotions. */
2742 nargs = convert_arguments (nargs, argarray, parm_types,
2743 params, fndecl, LOOKUP_NORMAL);
2745 return error_mark_node;
2747 /* Check for errors in format strings and inappropriately
2750 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2753 return build_cxx_call (function, nargs, argarray);
2756 /* Convert the actual parameter expressions in the list VALUES
2757 to the types in the list TYPELIST.
2758 If parmdecls is exhausted, or when an element has NULL as its type,
2759 perform the default conversions.
2761 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2763 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2765 This is also where warnings about wrong number of args are generated.
2767 Returns the actual number of arguments processed (which might be less
2768 than NARGS), or -1 on error.
2770 VALUES is a chain of TREE_LIST nodes with the elements of the list
2771 in the TREE_VALUE slots of those nodes.
2773 In C++, unspecified trailing parameters can be filled in with their
2774 default arguments, if such were specified. Do so here. */
2777 convert_arguments (int nargs, tree *argarray,
2778 tree typelist, tree values, tree fndecl, int flags)
2780 tree typetail, valtail;
2781 const char *called_thing = 0;
2784 /* Argument passing is always copy-initialization. */
2785 flags |= LOOKUP_ONLYCONVERTING;
2789 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2791 if (DECL_NAME (fndecl) == NULL_TREE
2792 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2793 called_thing = "constructor";
2795 called_thing = "member function";
2798 called_thing = "function";
2801 for (valtail = values, typetail = typelist;
2803 valtail = TREE_CHAIN (valtail), i++)
2805 tree type = typetail ? TREE_VALUE (typetail) : 0;
2806 tree val = TREE_VALUE (valtail);
2808 if (val == error_mark_node || type == error_mark_node)
2811 if (type == void_type_node)
2815 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2816 error ("at this point in file");
2819 error ("too many arguments to function");
2823 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2824 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2825 if (TREE_CODE (val) == NOP_EXPR
2826 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2827 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2828 val = TREE_OPERAND (val, 0);
2830 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2832 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2833 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2834 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2835 val = decay_conversion (val);
2838 if (val == error_mark_node)
2843 /* Formal parm type is specified by a function prototype. */
2846 if (!COMPLETE_TYPE_P (complete_type (type)))
2849 error ("parameter %P of %qD has incomplete type %qT",
2852 error ("parameter %P has incomplete type %qT", i, type);
2853 parmval = error_mark_node;
2857 parmval = convert_for_initialization
2858 (NULL_TREE, type, val, flags,
2859 "argument passing", fndecl, i);
2860 parmval = convert_for_arg_passing (type, parmval);
2863 if (parmval == error_mark_node)
2866 argarray[i] = parmval;
2870 if (fndecl && DECL_BUILT_IN (fndecl)
2871 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2872 /* Don't do ellipsis conversion for __built_in_constant_p
2873 as this will result in spurious warnings for non-POD
2875 val = require_complete_type (val);
2877 val = convert_arg_to_ellipsis (val);
2883 typetail = TREE_CHAIN (typetail);
2886 if (typetail != 0 && typetail != void_list_node)
2888 /* See if there are default arguments that can be used. Because
2889 we hold default arguments in the FUNCTION_TYPE (which is so
2890 wrong), we can see default parameters here from deduced
2891 contexts (and via typeof) for indirect function calls.
2892 Fortunately we know whether we have a function decl to
2893 provide default arguments in a language conformant
2895 if (fndecl && TREE_PURPOSE (typetail)
2896 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2898 for (; typetail != void_list_node; ++i)
2901 = convert_default_arg (TREE_VALUE (typetail),
2902 TREE_PURPOSE (typetail),
2905 if (parmval == error_mark_node)
2908 argarray[i] = parmval;
2909 typetail = TREE_CHAIN (typetail);
2910 /* ends with `...'. */
2911 if (typetail == NULL_TREE)
2919 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2920 error ("at this point in file");
2923 error ("too few arguments to function");
2928 gcc_assert (i <= nargs);
2932 /* Build a binary-operation expression, after performing default
2933 conversions on the operands. CODE is the kind of expression to
2934 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2935 are the tree codes which correspond to ARG1 and ARG2 when issuing
2936 warnings about possibly misplaced parentheses. They may differ
2937 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2938 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2939 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2940 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2941 ARG2_CODE as ERROR_MARK. */
2944 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2945 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2954 if (processing_template_decl)
2956 if (type_dependent_expression_p (arg1)
2957 || type_dependent_expression_p (arg2))
2958 return build_min_nt (code, arg1, arg2);
2959 arg1 = build_non_dependent_expr (arg1);
2960 arg2 = build_non_dependent_expr (arg2);
2963 if (code == DOTSTAR_EXPR)
2964 expr = build_m_component_ref (arg1, arg2);
2966 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2969 /* Check for cases such as x+y<<z which users are likely to
2970 misinterpret. But don't warn about obj << x + y, since that is a
2971 common idiom for I/O. */
2972 if (warn_parentheses
2973 && !processing_template_decl
2974 && !error_operand_p (arg1)
2975 && !error_operand_p (arg2)
2976 && (code != LSHIFT_EXPR
2977 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2978 warn_about_parentheses (code, arg1_code, arg2_code);
2980 if (processing_template_decl && expr != error_mark_node)
2981 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2986 /* Build a binary-operation expression without default conversions.
2987 CODE is the kind of expression to build.
2988 This function differs from `build' in several ways:
2989 the data type of the result is computed and recorded in it,
2990 warnings are generated if arg data types are invalid,
2991 special handling for addition and subtraction of pointers is known,
2992 and some optimization is done (operations on narrow ints
2993 are done in the narrower type when that gives the same result).
2994 Constant folding is also done before the result is returned.
2996 Note that the operands will never have enumeral types
2997 because either they have just had the default conversions performed
2998 or they have both just been converted to some other type in which
2999 the arithmetic is to be done.
3001 C++: must do special pointer arithmetic when implementing
3002 multiple inheritance, and deal with pointer to member functions. */
3005 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3006 int convert_p ATTRIBUTE_UNUSED)
3009 enum tree_code code0, code1;
3011 const char *invalid_op_diag;
3013 /* Expression code to give to the expression when it is built.
3014 Normally this is CODE, which is what the caller asked for,
3015 but in some special cases we change it. */
3016 enum tree_code resultcode = code;
3018 /* Data type in which the computation is to be performed.
3019 In the simplest cases this is the common type of the arguments. */
3020 tree result_type = NULL;
3022 /* Nonzero means operands have already been type-converted
3023 in whatever way is necessary.
3024 Zero means they need to be converted to RESULT_TYPE. */
3027 /* Nonzero means create the expression with this type, rather than
3029 tree build_type = 0;
3031 /* Nonzero means after finally constructing the expression
3032 convert it to this type. */
3033 tree final_type = 0;
3037 /* Nonzero if this is an operation like MIN or MAX which can
3038 safely be computed in short if both args are promoted shorts.
3039 Also implies COMMON.
3040 -1 indicates a bitwise operation; this makes a difference
3041 in the exact conditions for when it is safe to do the operation
3042 in a narrower mode. */
3045 /* Nonzero if this is a comparison operation;
3046 if both args are promoted shorts, compare the original shorts.
3047 Also implies COMMON. */
3048 int short_compare = 0;
3050 /* Nonzero if this is a right-shift operation, which can be computed on the
3051 original short and then promoted if the operand is a promoted short. */
3052 int short_shift = 0;
3054 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3057 /* True if both operands have arithmetic type. */
3058 bool arithmetic_types_p;
3060 /* Apply default conversions. */
3064 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3065 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3066 || code == TRUTH_XOR_EXPR)
3068 if (!really_overloaded_fn (op0))
3069 op0 = decay_conversion (op0);
3070 if (!really_overloaded_fn (op1))
3071 op1 = decay_conversion (op1);
3075 if (!really_overloaded_fn (op0))
3076 op0 = default_conversion (op0);
3077 if (!really_overloaded_fn (op1))
3078 op1 = default_conversion (op1);
3081 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3082 STRIP_TYPE_NOPS (op0);
3083 STRIP_TYPE_NOPS (op1);
3085 /* DTRT if one side is an overloaded function, but complain about it. */
3086 if (type_unknown_p (op0))
3088 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3089 if (t != error_mark_node)
3091 pedwarn ("assuming cast to type %qT from overloaded function",
3096 if (type_unknown_p (op1))
3098 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3099 if (t != error_mark_node)
3101 pedwarn ("assuming cast to type %qT from overloaded function",
3107 type0 = TREE_TYPE (op0);
3108 type1 = TREE_TYPE (op1);
3110 /* The expression codes of the data types of the arguments tell us
3111 whether the arguments are integers, floating, pointers, etc. */
3112 code0 = TREE_CODE (type0);
3113 code1 = TREE_CODE (type1);
3115 /* If an error was already reported for one of the arguments,
3116 avoid reporting another error. */
3118 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3119 return error_mark_node;
3121 if ((invalid_op_diag
3122 = targetm.invalid_binary_op (code, type0, type1)))
3124 error (invalid_op_diag);
3125 return error_mark_node;
3131 /* Subtraction of two similar pointers.
3132 We must subtract them as integers, then divide by object size. */
3133 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3134 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3136 return pointer_diff (op0, op1, common_type (type0, type1));
3137 /* In all other cases except pointer - int, the usual arithmetic
3139 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3144 /* The pointer - int case is just like pointer + int; fall
3147 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3148 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3152 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3153 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3154 if (processing_template_decl)
3156 result_type = TREE_TYPE (ptr_operand);
3159 return cp_pointer_int_sum (code,
3170 case TRUNC_DIV_EXPR:
3172 case FLOOR_DIV_EXPR:
3173 case ROUND_DIV_EXPR:
3174 case EXACT_DIV_EXPR:
3175 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3176 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3177 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3178 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3180 enum tree_code tcode0 = code0, tcode1 = code1;
3182 warn_for_div_by_zero (op1);
3184 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3185 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3186 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3187 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3189 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3190 resultcode = RDIV_EXPR;
3192 /* When dividing two signed integers, we have to promote to int.
3193 unless we divide by a constant != -1. Note that default
3194 conversion will have been performed on the operands at this
3195 point, so we have to dig out the original type to find out if
3197 shorten = ((TREE_CODE (op0) == NOP_EXPR
3198 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3199 || (TREE_CODE (op1) == INTEGER_CST
3200 && ! integer_all_onesp (op1)));
3209 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3210 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3214 case TRUNC_MOD_EXPR:
3215 case FLOOR_MOD_EXPR:
3216 warn_for_div_by_zero (op1);
3218 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3220 /* Although it would be tempting to shorten always here, that loses
3221 on some targets, since the modulo instruction is undefined if the
3222 quotient can't be represented in the computation mode. We shorten
3223 only if unsigned or if dividing by something we know != -1. */
3224 shorten = ((TREE_CODE (op0) == NOP_EXPR
3225 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3226 || (TREE_CODE (op1) == INTEGER_CST
3227 && ! integer_all_onesp (op1)));
3232 case TRUTH_ANDIF_EXPR:
3233 case TRUTH_ORIF_EXPR:
3234 case TRUTH_AND_EXPR:
3236 result_type = boolean_type_node;
3239 /* Shift operations: result has same type as first operand;
3240 always convert second operand to int.
3241 Also set SHORT_SHIFT if shifting rightward. */
3244 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3246 result_type = type0;
3247 if (TREE_CODE (op1) == INTEGER_CST)
3249 if (tree_int_cst_lt (op1, integer_zero_node))
3250 warning (0, "right shift count is negative");
3253 if (! integer_zerop (op1))
3255 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3256 warning (0, "right shift count >= width of type");
3259 /* Convert the shift-count to an integer, regardless of
3260 size of value being shifted. */
3261 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3262 op1 = cp_convert (integer_type_node, op1);
3263 /* Avoid converting op1 to result_type later. */
3269 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3271 result_type = type0;
3272 if (TREE_CODE (op1) == INTEGER_CST)
3274 if (tree_int_cst_lt (op1, integer_zero_node))
3275 warning (0, "left shift count is negative");
3276 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3277 warning (0, "left shift count >= width of type");
3279 /* Convert the shift-count to an integer, regardless of
3280 size of value being shifted. */
3281 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3282 op1 = cp_convert (integer_type_node, op1);
3283 /* Avoid converting op1 to result_type later. */
3290 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3292 result_type = type0;
3293 if (TREE_CODE (op1) == INTEGER_CST)
3295 if (tree_int_cst_lt (op1, integer_zero_node))
3296 warning (0, (code == LROTATE_EXPR)
3297 ? G_("left rotate count is negative")
3298 : G_("right rotate count is negative"));
3299 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3300 warning (0, (code == LROTATE_EXPR)
3301 ? G_("left rotate count >= width of type")
3302 : G_("right rotate count >= width of type"));
3304 /* Convert the shift-count to an integer, regardless of
3305 size of value being shifted. */
3306 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3307 op1 = cp_convert (integer_type_node, op1);
3313 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3314 warning (OPT_Wfloat_equal,
3315 "comparing floating point with == or != is unsafe");
3316 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3317 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3318 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3320 build_type = boolean_type_node;
3321 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3322 || code0 == COMPLEX_TYPE)
3323 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3324 || code1 == COMPLEX_TYPE))
3326 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3327 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3328 result_type = composite_pointer_type (type0, type1, op0, op1,
3330 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3331 && null_ptr_cst_p (op1))
3333 if (TREE_CODE (op0) == ADDR_EXPR
3334 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3335 warning (OPT_Waddress, "the address of %qD will never be NULL",
3336 TREE_OPERAND (op0, 0));
3337 result_type = type0;
3339 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3340 && null_ptr_cst_p (op0))
3342 if (TREE_CODE (op1) == ADDR_EXPR
3343 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3344 warning (OPT_Waddress, "the address of %qD will never be NULL",
3345 TREE_OPERAND (op1, 0));
3346 result_type = type1;
3348 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3350 result_type = type0;
3351 error ("ISO C++ forbids comparison between pointer and integer");
3353 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3355 result_type = type1;
3356 error ("ISO C++ forbids comparison between pointer and integer");
3358 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3360 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3361 == ptrmemfunc_vbit_in_delta)
3363 tree pfn0 = pfn_from_ptrmemfunc (op0);
3364 tree delta0 = build_ptrmemfunc_access_expr (op0,
3366 tree e1 = cp_build_binary_op (EQ_EXPR,
3368 fold_convert (TREE_TYPE (pfn0),
3369 integer_zero_node));
3370 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3373 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3374 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3375 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3379 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3380 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3382 result_type = TREE_TYPE (op0);
3384 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3385 return cp_build_binary_op (code, op1, op0);
3386 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3387 && same_type_p (type0, type1))
3389 /* E will be the final comparison. */
3391 /* E1 and E2 are for scratch. */
3399 if (TREE_SIDE_EFFECTS (op0))
3400 op0 = save_expr (op0);
3401 if (TREE_SIDE_EFFECTS (op1))
3402 op1 = save_expr (op1);
3404 pfn0 = pfn_from_ptrmemfunc (op0);
3405 pfn1 = pfn_from_ptrmemfunc (op1);
3406 delta0 = build_ptrmemfunc_access_expr (op0,
3408 delta1 = build_ptrmemfunc_access_expr (op1,
3410 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3411 == ptrmemfunc_vbit_in_delta)
3416 && ((op0.delta == op1.delta)
3417 || (!op0.pfn && op0.delta & 1 == 0
3418 && op1.delta & 1 == 0))
3420 The reason for the `!op0.pfn' bit is that a NULL
3421 pointer-to-member is any member with a zero PFN and
3422 LSB of the DELTA field is 0. */
3424 e1 = cp_build_binary_op (BIT_AND_EXPR,
3427 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3428 e2 = cp_build_binary_op (BIT_AND_EXPR,
3431 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3432 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3433 e2 = cp_build_binary_op (EQ_EXPR,
3435 fold_convert (TREE_TYPE (pfn0),
3436 integer_zero_node));
3437 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3438 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3439 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3446 && (!op0.pfn || op0.delta == op1.delta))
3448 The reason for the `!op0.pfn' bit is that a NULL
3449 pointer-to-member is any member with a zero PFN; the
3450 DELTA field is unspecified. */
3452 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3453 e2 = cp_build_binary_op (EQ_EXPR,
3455 fold_convert (TREE_TYPE (pfn0),
3456 integer_zero_node));
3457 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3459 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3460 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3461 if (code == EQ_EXPR)
3463 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3467 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3468 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3470 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3471 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3479 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3480 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3482 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3483 result_type = composite_pointer_type (type0, type1, op0, op1,
3491 if (TREE_CODE (orig_op0) == STRING_CST
3492 || TREE_CODE (orig_op1) == STRING_CST)
3493 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3495 build_type = boolean_type_node;
3496 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3497 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3499 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3500 result_type = composite_pointer_type (type0, type1, op0, op1,
3502 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3503 && integer_zerop (op1))
3504 result_type = type0;
3505 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3506 && integer_zerop (op0))
3507 result_type = type1;
3508 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3510 result_type = type0;
3511 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3513 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3515 result_type = type1;
3516 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3520 case UNORDERED_EXPR:
3527 build_type = integer_type_node;
3528 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3530 error ("unordered comparison on non-floating point argument");
3531 return error_mark_node;
3540 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3541 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3542 || code1 == COMPLEX_TYPE)))
3543 arithmetic_types_p = 1;
3546 arithmetic_types_p = 0;
3547 /* Vector arithmetic is only allowed when both sides are vectors. */
3548 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3550 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3551 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3554 binary_op_error (code, type0, type1);
3555 return error_mark_node;
3557 arithmetic_types_p = 1;
3560 /* Determine the RESULT_TYPE, if it is not already known. */
3562 && arithmetic_types_p
3563 && (shorten || common || short_compare))
3564 result_type = common_type (type0, type1);
3568 error ("invalid operands of types %qT and %qT to binary %qO",
3569 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3570 return error_mark_node;
3573 /* If we're in a template, the only thing we need to know is the
3575 if (processing_template_decl)
3577 /* Since the middle-end checks the type when doing a build2, we
3578 need to build the tree in pieces. This built tree will never
3579 get out of the front-end as we replace it when instantiating
3581 tree tmp = build2 (resultcode,
3582 build_type ? build_type : result_type,
3584 TREE_OPERAND (tmp, 0) = op0;
3588 if (arithmetic_types_p)
3590 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3592 /* For certain operations (which identify themselves by shorten != 0)
3593 if both args were extended from the same smaller type,
3594 do the arithmetic in that type and then extend.
3596 shorten !=0 and !=1 indicates a bitwise operation.
3597 For them, this optimization is safe only if
3598 both args are zero-extended or both are sign-extended.
3599 Otherwise, we might change the result.
3600 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3601 but calculated in (unsigned short) it would be (unsigned short)-1. */
3603 if (shorten && none_complex)
3605 int unsigned0, unsigned1;
3606 tree arg0 = get_narrower (op0, &unsigned0);
3607 tree arg1 = get_narrower (op1, &unsigned1);
3608 /* UNS is 1 if the operation to be done is an unsigned one. */
3609 int uns = TYPE_UNSIGNED (result_type);
3612 final_type = result_type;
3614 /* Handle the case that OP0 does not *contain* a conversion
3615 but it *requires* conversion to FINAL_TYPE. */
3617 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3618 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3619 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3620 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3622 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3624 /* For bitwise operations, signedness of nominal type
3625 does not matter. Consider only how operands were extended. */
3629 /* Note that in all three cases below we refrain from optimizing
3630 an unsigned operation on sign-extended args.
3631 That would not be valid. */
3633 /* Both args variable: if both extended in same way
3634 from same width, do it in that width.
3635 Do it unsigned if args were zero-extended. */
3636 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3637 < TYPE_PRECISION (result_type))
3638 && (TYPE_PRECISION (TREE_TYPE (arg1))
3639 == TYPE_PRECISION (TREE_TYPE (arg0)))
3640 && unsigned0 == unsigned1
3641 && (unsigned0 || !uns))
3642 result_type = c_common_signed_or_unsigned_type
3643 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3644 else if (TREE_CODE (arg0) == INTEGER_CST
3645 && (unsigned1 || !uns)
3646 && (TYPE_PRECISION (TREE_TYPE (arg1))
3647 < TYPE_PRECISION (result_type))
3648 && (type = c_common_signed_or_unsigned_type
3649 (unsigned1, TREE_TYPE (arg1)),
3650 int_fits_type_p (arg0, type)))
3652 else if (TREE_CODE (arg1) == INTEGER_CST
3653 && (unsigned0 || !uns)
3654 && (TYPE_PRECISION (TREE_TYPE (arg0))
3655 < TYPE_PRECISION (result_type))
3656 && (type = c_common_signed_or_unsigned_type
3657 (unsigned0, TREE_TYPE (arg0)),
3658 int_fits_type_p (arg1, type)))
3662 /* Shifts can be shortened if shifting right. */
3667 tree arg0 = get_narrower (op0, &unsigned_arg);
3669 final_type = result_type;
3671 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3672 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3674 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3675 /* We can shorten only if the shift count is less than the
3676 number of bits in the smaller type size. */
3677 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3678 /* If arg is sign-extended and then unsigned-shifted,
3679 we can simulate this with a signed shift in arg's type
3680 only if the extended result is at least twice as wide
3681 as the arg. Otherwise, the shift could use up all the
3682 ones made by sign-extension and bring in zeros.
3683 We can't optimize that case at all, but in most machines
3684 it never happens because available widths are 2**N. */
3685 && (!TYPE_UNSIGNED (final_type)
3687 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3688 <= TYPE_PRECISION (result_type))))
3690 /* Do an unsigned shift if the operand was zero-extended. */
3692 = c_common_signed_or_unsigned_type (unsigned_arg,
3694 /* Convert value-to-be-shifted to that type. */
3695 if (TREE_TYPE (op0) != result_type)
3696 op0 = cp_convert (result_type, op0);
3701 /* Comparison operations are shortened too but differently.
3702 They identify themselves by setting short_compare = 1. */
3706 /* Don't write &op0, etc., because that would prevent op0
3707 from being kept in a register.
3708 Instead, make copies of the our local variables and
3709 pass the copies by reference, then copy them back afterward. */
3710 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3711 enum tree_code xresultcode = resultcode;
3713 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3715 return cp_convert (boolean_type_node, val);
3716 op0 = xop0, op1 = xop1;
3718 resultcode = xresultcode;
3721 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3722 && warn_sign_compare
3723 /* Do not warn until the template is instantiated; we cannot
3724 bound the ranges of the arguments until that point. */
3725 && !processing_template_decl)
3727 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3728 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3730 int unsignedp0, unsignedp1;
3731 tree primop0 = get_narrower (op0, &unsignedp0);
3732 tree primop1 = get_narrower (op1, &unsignedp1);
3734 /* Check for comparison of different enum types. */
3735 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3736 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3737 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3738 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3740 warning (0, "comparison between types %q#T and %q#T",
3741 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3744 /* Give warnings for comparisons between signed and unsigned
3745 quantities that may fail. */
3746 /* Do the checking based on the original operand trees, so that
3747 casts will be considered, but default promotions won't be. */
3749 /* Do not warn if the comparison is being done in a signed type,
3750 since the signed type will only be chosen if it can represent
3751 all the values of the unsigned type. */
3752 if (!TYPE_UNSIGNED (result_type))
3754 /* Do not warn if both operands are unsigned. */
3755 else if (op0_signed == op1_signed)
3757 /* Do not warn if the signed quantity is an unsuffixed
3758 integer literal (or some static constant expression
3759 involving such literals or a conditional expression
3760 involving such literals) and it is non-negative. */
3761 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3762 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3764 /* Do not warn if the comparison is an equality operation,
3765 the unsigned quantity is an integral constant and it does
3766 not use the most significant bit of result_type. */
3767 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3768 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3769 && int_fits_type_p (orig_op1, c_common_signed_type
3771 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3772 && int_fits_type_p (orig_op0, c_common_signed_type
3776 warning (0, "comparison between signed and unsigned integer expressions");
3778 /* Warn if two unsigned values are being compared in a size
3779 larger than their original size, and one (and only one) is the
3780 result of a `~' operator. This comparison will always fail.
3782 Also warn if one operand is a constant, and the constant does not
3783 have all bits set that are set in the ~ operand when it is
3786 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3787 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3789 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3790 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3791 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3792 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3794 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3797 HOST_WIDE_INT constant, mask;
3801 if (host_integerp (primop0, 0))
3804 unsignedp = unsignedp1;
3805 constant = tree_low_cst (primop0, 0);
3810 unsignedp = unsignedp0;
3811 constant = tree_low_cst (primop1, 0);
3814 bits = TYPE_PRECISION (TREE_TYPE (primop));
3815 if (bits < TYPE_PRECISION (result_type)
3816 && bits < HOST_BITS_PER_LONG && unsignedp)
3818 mask = (~ (HOST_WIDE_INT) 0) << bits;
3819 if ((mask & constant) != mask)
3820 warning (0, "comparison of promoted ~unsigned with constant");
3823 else if (unsignedp0 && unsignedp1
3824 && (TYPE_PRECISION (TREE_TYPE (primop0))
3825 < TYPE_PRECISION (result_type))
3826 && (TYPE_PRECISION (TREE_TYPE (primop1))
3827 < TYPE_PRECISION (result_type)))
3828 warning (0, "comparison of promoted ~unsigned with unsigned");
3833 /* Issue warnings about peculiar, but valid, uses of NULL. */
3834 if ((orig_op0 == null_node || orig_op1 == null_node)
3835 /* It's reasonable to use pointer values as operands of &&
3836 and ||, so NULL is no exception. */
3837 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3838 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3839 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3840 && code != EQ_EXPR && code != NE_EXPR)
3841 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3842 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3843 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3844 /* Some sort of arithmetic operation involving NULL was
3845 performed. Note that pointer-difference and pointer-addition
3846 have already been handled above, and so we don't end up here in
3848 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3851 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3852 Then the expression will be built.
3853 It will be given type FINAL_TYPE if that is nonzero;
3854 otherwise, it will be given type RESULT_TYPE. */
3857 if (TREE_TYPE (op0) != result_type)
3858 op0 = cp_convert_and_check (result_type, op0);
3859 if (TREE_TYPE (op1) != result_type)
3860 op1 = cp_convert_and_check (result_type, op1);
3862 if (op0 == error_mark_node || op1 == error_mark_node)
3863 return error_mark_node;
3866 if (build_type == NULL_TREE)
3867 build_type = result_type;
3869 result = build2 (resultcode, build_type, op0, op1);
3870 result = fold_if_not_in_template (result);
3871 if (final_type != 0)
3872 result = cp_convert (final_type, result);
3874 if (TREE_OVERFLOW_P (result)
3875 && !TREE_OVERFLOW_P (op0)
3876 && !TREE_OVERFLOW_P (op1))
3877 overflow_warning (result);
3882 /* Return a tree for the sum or difference (RESULTCODE says which)
3883 of pointer PTROP and integer INTOP. */
3886 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3888 tree res_type = TREE_TYPE (ptrop);
3890 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3891 in certain circumstance (when it's valid to do so). So we need
3892 to make sure it's complete. We don't need to check here, if we
3893 can actually complete it at all, as those checks will be done in
3894 pointer_int_sum() anyway. */
3895 complete_type (TREE_TYPE (res_type));
3897 return pointer_int_sum (resultcode, ptrop,
3898 fold_if_not_in_template (intop));
3901 /* Return a tree for the difference of pointers OP0 and OP1.
3902 The resulting tree has type int. */
3905 pointer_diff (tree op0, tree op1, tree ptrtype)
3908 tree restype = ptrdiff_type_node;
3909 tree target_type = TREE_TYPE (ptrtype);
3911 if (!complete_type_or_else (target_type, NULL_TREE))
3912 return error_mark_node;
3914 if (pedantic || warn_pointer_arith)
3916 if (TREE_CODE (target_type) == VOID_TYPE)
3917 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3918 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3919 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3920 if (TREE_CODE (target_type) == METHOD_TYPE)
3921 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3924 /* First do the subtraction as integers;
3925 then drop through to build the divide operator. */
3927 op0 = cp_build_binary_op (MINUS_EXPR,
3928 cp_convert (restype, op0),
3929 cp_convert (restype, op1));
3931 /* This generates an error if op1 is a pointer to an incomplete type. */
3932 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3933 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3935 op1 = (TYPE_PTROB_P (ptrtype)
3936 ? size_in_bytes (target_type)
3937 : integer_one_node);
3939 /* Do the division. */
3941 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3942 return fold_if_not_in_template (result);
3945 /* Construct and perhaps optimize a tree representation
3946 for a unary operation. CODE, a tree_code, specifies the operation
3947 and XARG is the operand. */
3950 build_x_unary_op (enum tree_code code, tree xarg)
3952 tree orig_expr = xarg;
3956 if (processing_template_decl)
3958 if (type_dependent_expression_p (xarg))
3959 return build_min_nt (code, xarg, NULL_TREE);
3961 xarg = build_non_dependent_expr (xarg);
3966 /* [expr.unary.op] says:
3968 The address of an object of incomplete type can be taken.
3970 (And is just the ordinary address operator, not an overloaded
3971 "operator &".) However, if the type is a template
3972 specialization, we must complete the type at this point so that
3973 an overloaded "operator &" will be available if required. */
3974 if (code == ADDR_EXPR
3975 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3976 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3977 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3978 || (TREE_CODE (xarg) == OFFSET_REF)))
3979 /* Don't look for a function. */;
3981 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3982 /*overloaded_p=*/NULL);
3983 if (!exp && code == ADDR_EXPR)
3985 /* A pointer to member-function can be formed only by saying
3987 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3988 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3990 if (TREE_CODE (xarg) != OFFSET_REF
3991 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3993 error ("invalid use of %qE to form a pointer-to-member-function",
3995 if (TREE_CODE (xarg) != OFFSET_REF)
3996 inform (" a qualified-id is required");
3997 return error_mark_node;
4001 error ("parentheses around %qE cannot be used to form a"
4002 " pointer-to-member-function",
4004 PTRMEM_OK_P (xarg) = 1;
4008 if (TREE_CODE (xarg) == OFFSET_REF)
4010 ptrmem = PTRMEM_OK_P (xarg);
4012 if (!ptrmem && !flag_ms_extensions
4013 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4015 /* A single non-static member, make sure we don't allow a
4016 pointer-to-member. */
4017 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4018 TREE_OPERAND (xarg, 0),
4019 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4020 PTRMEM_OK_P (xarg) = ptrmem;
4023 else if (TREE_CODE (xarg) == TARGET_EXPR)
4024 warning (0, "taking address of temporary");
4025 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4028 if (processing_template_decl && exp != error_mark_node)
4029 exp = build_min_non_dep (code, exp, orig_expr,
4030 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4031 if (TREE_CODE (exp) == ADDR_EXPR)
4032 PTRMEM_OK_P (exp) = ptrmem;
4036 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4037 constants, where a null value is represented by an INTEGER_CST of
4041 cp_truthvalue_conversion (tree expr)
4043 tree type = TREE_TYPE (expr);
4044 if (TYPE_PTRMEM_P (type))
4045 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4047 return c_common_truthvalue_conversion (expr);
4050 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4053 condition_conversion (tree expr)
4056 if (processing_template_decl)
4058 t = perform_implicit_conversion (boolean_type_node, expr);
4059 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4063 /* Return an ADDR_EXPR giving the address of T. This function
4064 attempts no optimizations or simplifications; it is a low-level
4068 build_address (tree t)
4072 if (error_operand_p (t) || !cxx_mark_addressable (t))
4073 return error_mark_node;
4075 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4080 /* Return a NOP_EXPR converting EXPR to TYPE. */
4083 build_nop (tree type, tree expr)
4085 if (type == error_mark_node || error_operand_p (expr))
4087 return build1 (NOP_EXPR, type, expr);
4090 /* C++: Must handle pointers to members.
4092 Perhaps type instantiation should be extended to handle conversion
4093 from aggregates to types we don't yet know we want? (Or are those
4094 cases typically errors which should be reported?)
4096 NOCONVERT nonzero suppresses the default promotions
4097 (such as from short to int). */
4100 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4102 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4105 const char *errstring = NULL;
4107 const char *invalid_op_diag;
4109 if (arg == error_mark_node)
4110 return error_mark_node;
4112 if ((invalid_op_diag
4113 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4118 error (invalid_op_diag);
4119 return error_mark_node;
4124 case UNARY_PLUS_EXPR:
4127 int flags = WANT_ARITH | WANT_ENUM;
4128 /* Unary plus (but not unary minus) is allowed on pointers. */
4129 if (code == UNARY_PLUS_EXPR)
4130 flags |= WANT_POINTER;
4131 arg = build_expr_type_conversion (flags, arg, true);
4133 errstring = (code == NEGATE_EXPR
4134 ? "wrong type argument to unary minus"
4135 : "wrong type argument to unary plus");
4138 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4139 arg = perform_integral_promotions (arg);
4141 /* Make sure the result is not an lvalue: a unary plus or minus
4142 expression is always a rvalue. */
4149 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4153 arg = default_conversion (arg);
4155 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4158 errstring = "wrong type argument to bit-complement";
4159 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4160 arg = perform_integral_promotions (arg);
4164 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4165 errstring = "wrong type argument to abs";
4166 else if (!noconvert)
4167 arg = default_conversion (arg);
4171 /* Conjugating a real value is a no-op, but allow it anyway. */
4172 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4173 errstring = "wrong type argument to conjugation";
4174 else if (!noconvert)
4175 arg = default_conversion (arg);
4178 case TRUTH_NOT_EXPR:
4179 arg = perform_implicit_conversion (boolean_type_node, arg);
4180 val = invert_truthvalue (arg);
4181 if (arg != error_mark_node)
4183 errstring = "in argument to unary !";
4190 if (TREE_CODE (arg) == COMPLEX_CST)
4191 return TREE_REALPART (arg);
4192 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4194 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4195 return fold_if_not_in_template (arg);
4201 if (TREE_CODE (arg) == COMPLEX_CST)
4202 return TREE_IMAGPART (arg);
4203 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4205 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4206 return fold_if_not_in_template (arg);
4209 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4211 case PREINCREMENT_EXPR:
4212 case POSTINCREMENT_EXPR:
4213 case PREDECREMENT_EXPR:
4214 case POSTDECREMENT_EXPR:
4215 /* Handle complex lvalues (when permitted)
4216 by reduction to simpler cases. */
4218 val = unary_complex_lvalue (code, arg);
4222 /* Increment or decrement the real part of the value,
4223 and don't change the imaginary part. */
4224 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4228 arg = stabilize_reference (arg);
4229 real = build_unary_op (REALPART_EXPR, arg, 1);
4230 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4231 real = build_unary_op (code, real, 1);
4232 if (real == error_mark_node || imag == error_mark_node)
4233 return error_mark_node;
4234 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4238 /* Report invalid types. */
4240 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4243 if (code == PREINCREMENT_EXPR)
4244 errstring ="no pre-increment operator for type";
4245 else if (code == POSTINCREMENT_EXPR)
4246 errstring ="no post-increment operator for type";
4247 else if (code == PREDECREMENT_EXPR)
4248 errstring ="no pre-decrement operator for type";
4250 errstring ="no post-decrement operator for type";
4254 /* Report something read-only. */
4256 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4257 || TREE_READONLY (arg))
4258 readonly_error (arg, ((code == PREINCREMENT_EXPR
4259 || code == POSTINCREMENT_EXPR)
4260 ? "increment" : "decrement"));
4265 tree result_type = TREE_TYPE (arg);
4267 declared_type = unlowered_expr_type (arg);
4269 arg = get_unwidened (arg, 0);
4270 argtype = TREE_TYPE (arg);
4272 /* ARM $5.2.5 last annotation says this should be forbidden. */
4273 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4274 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4275 ? G_("ISO C++ forbids incrementing an enum")
4276 : G_("ISO C++ forbids decrementing an enum"));
4278 /* Compute the increment. */
4280 if (TREE_CODE (argtype) == POINTER_TYPE)
4282 tree type = complete_type (TREE_TYPE (argtype));
4284 if (!COMPLETE_OR_VOID_TYPE_P (type))
4285 error (((code == PREINCREMENT_EXPR
4286 || code == POSTINCREMENT_EXPR))
4287 ? G_("cannot increment a pointer to incomplete type %qT")
4288 : G_("cannot decrement a pointer to incomplete type %qT"),
4289 TREE_TYPE (argtype));
4290 else if ((pedantic || warn_pointer_arith)
4291 && !TYPE_PTROB_P (argtype))
4292 pedwarn ((code == PREINCREMENT_EXPR
4293 || code == POSTINCREMENT_EXPR)
4294 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4295 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4297 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4300 inc = integer_one_node;
4302 inc = cp_convert (argtype, inc);
4304 /* Complain about anything else that is not a true lvalue. */
4305 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4306 || code == POSTINCREMENT_EXPR)
4307 ? lv_increment : lv_decrement)))
4308 return error_mark_node;
4310 /* Forbid using -- on `bool'. */
4311 if (same_type_p (declared_type, boolean_type_node))
4313 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4315 error ("invalid use of %<--%> on bool variable %qD", arg);
4316 return error_mark_node;
4318 val = boolean_increment (code, arg);
4321 val = build2 (code, TREE_TYPE (arg), arg, inc);
4323 TREE_SIDE_EFFECTS (val) = 1;
4324 return cp_convert (result_type, val);
4328 /* Note that this operation never does default_conversion
4329 regardless of NOCONVERT. */
4331 argtype = lvalue_type (arg);
4333 if (TREE_CODE (arg) == OFFSET_REF)
4336 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4338 tree type = build_pointer_type (TREE_TYPE (argtype));
4339 arg = build1 (CONVERT_EXPR, type, arg);
4342 else if (pedantic && DECL_MAIN_P (arg))
4344 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4346 /* Let &* cancel out to simplify resulting code. */
4347 if (TREE_CODE (arg) == INDIRECT_REF)
4349 /* We don't need to have `current_class_ptr' wrapped in a
4350 NON_LVALUE_EXPR node. */
4351 if (arg == current_class_ref)
4352 return current_class_ptr;
4354 arg = TREE_OPERAND (arg, 0);
4355 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4357 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4358 arg = build1 (CONVERT_EXPR, type, arg);
4361 /* Don't let this be an lvalue. */
4366 /* Uninstantiated types are all functions. Taking the
4367 address of a function is a no-op, so just return the
4370 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4371 || !IDENTIFIER_OPNAME_P (arg));
4373 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4374 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4376 /* They're trying to take the address of a unique non-static
4377 member function. This is ill-formed (except in MS-land),
4378 but let's try to DTRT.
4379 Note: We only handle unique functions here because we don't
4380 want to complain if there's a static overload; non-unique
4381 cases will be handled by instantiate_type. But we need to
4382 handle this case here to allow casts on the resulting PMF.
4383 We could defer this in non-MS mode, but it's easier to give
4384 a useful error here. */
4386 /* Inside constant member functions, the `this' pointer
4387 contains an extra const qualifier. TYPE_MAIN_VARIANT
4388 is used here to remove this const from the diagnostics
4389 and the created OFFSET_REF. */
4390 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4391 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4394 if (! flag_ms_extensions)
4396 tree name = DECL_NAME (fn);
4397 if (current_class_type
4398 && TREE_OPERAND (arg, 0) == current_class_ref)
4399 /* An expression like &memfn. */
4400 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4401 " or parenthesized non-static member function to form"
4402 " a pointer to member function. Say %<&%T::%D%>",
4405 pedwarn ("ISO C++ forbids taking the address of a bound member"
4406 " function to form a pointer to member function."
4410 arg = build_offset_ref (base, fn, /*address_p=*/true);
4414 if (type_unknown_p (arg))
4415 return build1 (ADDR_EXPR, unknown_type_node, arg);
4417 /* Handle complex lvalues (when permitted)
4418 by reduction to simpler cases. */
4419 val = unary_complex_lvalue (code, arg);
4423 switch (TREE_CODE (arg))
4428 case FIX_TRUNC_EXPR:
4429 if (! lvalue_p (arg) && pedantic)
4430 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4434 arg = BASELINK_FUNCTIONS (arg);
4438 arg = OVL_CURRENT (arg);
4442 /* Turn a reference to a non-static data member into a
4443 pointer-to-member. */
4448 if (!PTRMEM_OK_P (arg))
4449 return build_unary_op (code, arg, 0);
4451 t = TREE_OPERAND (arg, 1);
4452 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4454 error ("cannot create pointer to reference member %qD", t);
4455 return error_mark_node;
4458 type = build_ptrmem_type (context_for_name_lookup (t),
4460 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4468 /* Anything not already handled and not a true memory reference
4470 if (TREE_CODE (argtype) != FUNCTION_TYPE
4471 && TREE_CODE (argtype) != METHOD_TYPE
4472 && TREE_CODE (arg) != OFFSET_REF
4473 && !lvalue_or_else (arg, lv_addressof))
4474 return error_mark_node;
4476 if (argtype != error_mark_node)
4477 argtype = build_pointer_type (argtype);
4479 /* In a template, we are processing a non-dependent expression
4480 so we can just form an ADDR_EXPR with the correct type. */
4481 if (processing_template_decl)
4483 val = build_address (arg);
4484 if (TREE_CODE (arg) == OFFSET_REF)
4485 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4489 if (TREE_CODE (arg) != COMPONENT_REF)
4491 val = build_address (arg);
4492 if (TREE_CODE (arg) == OFFSET_REF)
4493 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4495 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4497 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4499 /* We can only get here with a single static member
4501 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4502 && DECL_STATIC_FUNCTION_P (fn));
4504 val = build_address (fn);
4505 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4506 /* Do not lose object's side effects. */
4507 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4508 TREE_OPERAND (arg, 0), val);
4510 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4512 error ("attempt to take address of bit-field structure member %qD",
4513 TREE_OPERAND (arg, 1));
4514 return error_mark_node;
4518 tree object = TREE_OPERAND (arg, 0);
4519 tree field = TREE_OPERAND (arg, 1);
4520 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4521 (TREE_TYPE (object), decl_type_context (field)));
4522 val = build_address (arg);
4525 if (TREE_CODE (argtype) == POINTER_TYPE
4526 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4528 build_ptrmemfunc_type (argtype);
4529 val = build_ptrmemfunc (argtype, val, 0,
4530 /*c_cast_p=*/false);
4542 argtype = TREE_TYPE (arg);
4543 return fold_if_not_in_template (build1 (code, argtype, arg));
4546 error ("%s", errstring);
4547 return error_mark_node;
4550 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4551 for certain kinds of expressions which are not really lvalues
4552 but which we can accept as lvalues.
4554 If ARG is not a kind of expression we can handle, return
4558 unary_complex_lvalue (enum tree_code code, tree arg)
4560 /* Inside a template, making these kinds of adjustments is
4561 pointless; we are only concerned with the type of the
4563 if (processing_template_decl)
4566 /* Handle (a, b) used as an "lvalue". */
4567 if (TREE_CODE (arg) == COMPOUND_EXPR)
4569 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4570 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4571 TREE_OPERAND (arg, 0), real_result);
4574 /* Handle (a ? b : c) used as an "lvalue". */
4575 if (TREE_CODE (arg) == COND_EXPR
4576 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4577 return rationalize_conditional_expr (code, arg);
4579 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4580 if (TREE_CODE (arg) == MODIFY_EXPR
4581 || TREE_CODE (arg) == PREINCREMENT_EXPR
4582 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4584 tree lvalue = TREE_OPERAND (arg, 0);
4585 if (TREE_SIDE_EFFECTS (lvalue))
4587 lvalue = stabilize_reference (lvalue);
4588 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4589 lvalue, TREE_OPERAND (arg, 1));
4591 return unary_complex_lvalue
4592 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4595 if (code != ADDR_EXPR)
4598 /* Handle (a = b) used as an "lvalue" for `&'. */
4599 if (TREE_CODE (arg) == MODIFY_EXPR
4600 || TREE_CODE (arg) == INIT_EXPR)
4602 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4603 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4605 TREE_NO_WARNING (arg) = 1;
4609 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4610 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4611 || TREE_CODE (arg) == OFFSET_REF)
4614 /* We permit compiler to make function calls returning
4615 objects of aggregate type look like lvalues. */
4619 if (TREE_CODE (targ) == SAVE_EXPR)
4620 targ = TREE_OPERAND (targ, 0);
4622 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4624 if (TREE_CODE (arg) == SAVE_EXPR)
4627 targ = build_cplus_new (TREE_TYPE (arg), arg);
4628 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4631 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4632 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4633 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4636 /* Don't let anything else be handled specially. */
4640 /* Mark EXP saying that we need to be able to take the
4641 address of it; it should not be allocated in a register.
4642 Value is true if successful.
4644 C++: we do not allow `current_class_ptr' to be addressable. */
4647 cxx_mark_addressable (tree exp)
4652 switch (TREE_CODE (x))
4659 x = TREE_OPERAND (x, 0);
4663 if (x == current_class_ptr)
4665 error ("cannot take the address of %<this%>, which is an rvalue expression");
4666 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4672 /* Caller should not be trying to mark initialized
4673 constant fields addressable. */
4674 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4675 || DECL_IN_AGGR_P (x) == 0
4677 || DECL_EXTERNAL (x));
4682 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4683 && !DECL_ARTIFICIAL (x))
4685 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4688 ("address of explicit register variable %qD requested", x);
4691 else if (extra_warnings)
4693 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4695 TREE_ADDRESSABLE (x) = 1;
4699 TREE_ADDRESSABLE (x) = 1;
4703 TREE_ADDRESSABLE (x) = 1;
4707 TREE_ADDRESSABLE (x) = 1;
4708 cxx_mark_addressable (TREE_OPERAND (x, 0));
4716 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4719 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4721 tree orig_ifexp = ifexp;
4722 tree orig_op1 = op1;
4723 tree orig_op2 = op2;
4726 if (processing_template_decl)
4728 /* The standard says that the expression is type-dependent if
4729 IFEXP is type-dependent, even though the eventual type of the
4730 expression doesn't dependent on IFEXP. */
4731 if (type_dependent_expression_p (ifexp)
4732 /* As a GNU extension, the middle operand may be omitted. */
4733 || (op1 && type_dependent_expression_p (op1))
4734 || type_dependent_expression_p (op2))
4735 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4736 ifexp = build_non_dependent_expr (ifexp);
4738 op1 = build_non_dependent_expr (op1);
4739 op2 = build_non_dependent_expr (op2);
4742 expr = build_conditional_expr (ifexp, op1, op2);
4743 if (processing_template_decl && expr != error_mark_node)
4744 return build_min_non_dep (COND_EXPR, expr,
4745 orig_ifexp, orig_op1, orig_op2);
4749 /* Given a list of expressions, return a compound expression
4750 that performs them all and returns the value of the last of them. */
4752 tree build_x_compound_expr_from_list (tree list, const char *msg)
4754 tree expr = TREE_VALUE (list);
4756 if (TREE_CHAIN (list))
4759 pedwarn ("%s expression list treated as compound expression", msg);
4761 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4762 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4768 /* Handle overloading of the ',' operator when needed. */
4771 build_x_compound_expr (tree op1, tree op2)
4774 tree orig_op1 = op1;
4775 tree orig_op2 = op2;
4777 if (processing_template_decl)
4779 if (type_dependent_expression_p (op1)
4780 || type_dependent_expression_p (op2))
4781 return build_min_nt (COMPOUND_EXPR, op1, op2);
4782 op1 = build_non_dependent_expr (op1);
4783 op2 = build_non_dependent_expr (op2);
4786 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4787 /*overloaded_p=*/NULL);
4789 result = build_compound_expr (op1, op2);
4791 if (processing_template_decl && result != error_mark_node)
4792 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4797 /* Build a compound expression. */
4800 build_compound_expr (tree lhs, tree rhs)
4802 lhs = convert_to_void (lhs, "left-hand operand of comma");
4804 if (lhs == error_mark_node || rhs == error_mark_node)
4805 return error_mark_node;
4807 if (TREE_CODE (rhs) == TARGET_EXPR)
4809 /* If the rhs is a TARGET_EXPR, then build the compound
4810 expression inside the target_expr's initializer. This
4811 helps the compiler to eliminate unnecessary temporaries. */
4812 tree init = TREE_OPERAND (rhs, 1);
4814 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4815 TREE_OPERAND (rhs, 1) = init;
4820 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4823 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4824 casts away constness. DIAG_FN gives the function to call if we
4825 need to issue a diagnostic; if it is NULL, no diagnostic will be
4826 issued. DESCRIPTION explains what operation is taking place. */
4829 check_for_casting_away_constness (tree src_type, tree dest_type,
4830 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4831 const char *description)
4833 if (diag_fn && casts_away_constness (src_type, dest_type))
4834 diag_fn ("%s from type %qT to type %qT casts away constness",
4835 description, src_type, dest_type);
4838 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4839 (another pointer-to-member type in the same hierarchy) and return
4840 the converted expression. If ALLOW_INVERSE_P is permitted, a
4841 pointer-to-derived may be converted to pointer-to-base; otherwise,
4842 only the other direction is permitted. If C_CAST_P is true, this
4843 conversion is taking place as part of a C-style cast. */
4846 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4849 if (TYPE_PTRMEM_P (type))
4853 if (TREE_CODE (expr) == PTRMEM_CST)
4854 expr = cplus_expand_constant (expr);
4855 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4856 TYPE_PTRMEM_CLASS_TYPE (type),
4859 if (!integer_zerop (delta))
4860 expr = cp_build_binary_op (PLUS_EXPR,
4861 build_nop (ptrdiff_type_node, expr),
4863 return build_nop (type, expr);
4866 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4867 allow_inverse_p, c_cast_p);
4870 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4871 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4872 Otherwise, return EXPR unchanged. */
4875 ignore_overflows (tree expr, tree orig)
4877 if (TREE_CODE (expr) == INTEGER_CST
4878 && CONSTANT_CLASS_P (orig)
4879 && TREE_CODE (orig) != STRING_CST
4880 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4882 if (!TREE_OVERFLOW (orig))
4883 /* Ensure constant sharing. */
4884 expr = build_int_cst_wide (TREE_TYPE (expr),
4885 TREE_INT_CST_LOW (expr),
4886 TREE_INT_CST_HIGH (expr));
4889 /* Avoid clobbering a shared constant. */
4890 expr = copy_node (expr);
4891 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4897 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4898 this static_cast is being attempted as one of the possible casts
4899 allowed by a C-style cast. (In that case, accessibility of base
4900 classes is not considered, and it is OK to cast away
4901 constness.) Return the result of the cast. *VALID_P is set to
4902 indicate whether or not the cast was valid. */
4905 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4911 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4914 /* Assume the cast is valid. */
4917 intype = TREE_TYPE (expr);
4919 /* Save casted types in the function's used types hash table. */
4920 used_types_insert (type);
4922 /* Determine what to do when casting away constness. */
4925 /* C-style casts are allowed to cast away constness. With
4926 WARN_CAST_QUAL, we still want to issue a warning. */
4927 diag_fn = warn_cast_qual ? warning0 : NULL;
4932 /* A static_cast may not cast away constness. */
4934 desc = "static_cast";
4937 /* [expr.static.cast]
4939 An lvalue of type "cv1 B", where B is a class type, can be cast
4940 to type "reference to cv2 D", where D is a class derived (clause
4941 _class.derived_) from B, if a valid standard conversion from
4942 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4943 same cv-qualification as, or greater cv-qualification than, cv1,
4944 and B is not a virtual base class of D. */
4945 /* We check this case before checking the validity of "TYPE t =
4946 EXPR;" below because for this case:
4949 struct D : public B { D(const B&); };
4951 void f() { static_cast<const D&>(b); }
4953 we want to avoid constructing a new D. The standard is not
4954 completely clear about this issue, but our interpretation is
4955 consistent with other compilers. */
4956 if (TREE_CODE (type) == REFERENCE_TYPE
4957 && CLASS_TYPE_P (TREE_TYPE (type))
4958 && CLASS_TYPE_P (intype)
4959 && real_lvalue_p (expr)
4960 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4961 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4962 build_pointer_type (TYPE_MAIN_VARIANT
4963 (TREE_TYPE (type))))
4965 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4969 /* There is a standard conversion from "D*" to "B*" even if "B"
4970 is ambiguous or inaccessible. If this is really a
4971 static_cast, then we check both for inaccessibility and
4972 ambiguity. However, if this is a static_cast being performed
4973 because the user wrote a C-style cast, then accessibility is
4975 base = lookup_base (TREE_TYPE (type), intype,
4976 c_cast_p ? ba_unique : ba_check,
4979 /* Convert from "B*" to "D*". This function will check that "B"
4980 is not a virtual base of "D". */
4981 expr = build_base_path (MINUS_EXPR, build_address (expr),
4982 base, /*nonnull=*/false);
4983 /* Convert the pointer to a reference -- but then remember that
4984 there are no expressions with reference type in C++. */
4985 return convert_from_reference (build_nop (type, expr));
4990 /* [expr.static.cast]
4992 An expression e can be explicitly converted to a type T using a
4993 static_cast of the form static_cast<T>(e) if the declaration T
4994 t(e);" is well-formed, for some invented temporary variable
4996 result = perform_direct_initialization_if_possible (type, expr,
5000 result = convert_from_reference (result);
5002 /* Ignore any integer overflow caused by the cast. */
5003 result = ignore_overflows (result, orig);
5005 /* [expr.static.cast]
5007 If T is a reference type, the result is an lvalue; otherwise,
5008 the result is an rvalue. */
5009 if (TREE_CODE (type) != REFERENCE_TYPE)
5010 result = rvalue (result);
5014 /* [expr.static.cast]
5016 Any expression can be explicitly converted to type cv void. */
5017 if (TREE_CODE (type) == VOID_TYPE)
5018 return convert_to_void (expr, /*implicit=*/NULL);
5020 /* [expr.static.cast]
5022 The inverse of any standard conversion sequence (clause _conv_),
5023 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5024 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5025 (_conv.bool_) conversions, can be performed explicitly using
5026 static_cast subject to the restriction that the explicit
5027 conversion does not cast away constness (_expr.const.cast_), and
5028 the following additional rules for specific cases: */
5029 /* For reference, the conversions not excluded are: integral
5030 promotions, floating point promotion, integral conversions,
5031 floating point conversions, floating-integral conversions,
5032 pointer conversions, and pointer to member conversions. */
5035 A value of integral _or enumeration_ type can be explicitly
5036 converted to an enumeration type. */
5037 /* The effect of all that is that any conversion between any two
5038 types which are integral, floating, or enumeration types can be
5040 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5041 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5043 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5045 /* Ignore any integer overflow caused by the cast. */
5046 expr = ignore_overflows (expr, orig);
5050 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5051 && CLASS_TYPE_P (TREE_TYPE (type))
5052 && CLASS_TYPE_P (TREE_TYPE (intype))
5053 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5054 (TREE_TYPE (intype))),
5055 build_pointer_type (TYPE_MAIN_VARIANT
5056 (TREE_TYPE (type)))))
5061 check_for_casting_away_constness (intype, type, diag_fn, desc);
5062 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5063 c_cast_p ? ba_unique : ba_check,
5065 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5068 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5069 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5076 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5077 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5079 if (TYPE_PTRMEM_P (type))
5081 t1 = (build_ptrmem_type
5083 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5084 t2 = (build_ptrmem_type
5086 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5093 if (can_convert (t1, t2))
5096 check_for_casting_away_constness (intype, type, diag_fn,
5098 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5103 /* [expr.static.cast]
5105 An rvalue of type "pointer to cv void" can be explicitly
5106 converted to a pointer to object type. A value of type pointer
5107 to object converted to "pointer to cv void" and back to the
5108 original pointer type will have its original value. */
5109 if (TREE_CODE (intype) == POINTER_TYPE
5110 && VOID_TYPE_P (TREE_TYPE (intype))
5111 && TYPE_PTROB_P (type))
5114 check_for_casting_away_constness (intype, type, diag_fn, desc);
5115 return build_nop (type, expr);
5119 return error_mark_node;
5122 /* Return an expression representing static_cast<TYPE>(EXPR). */
5125 build_static_cast (tree type, tree expr)
5130 if (type == error_mark_node || expr == error_mark_node)
5131 return error_mark_node;
5133 if (processing_template_decl)
5135 expr = build_min (STATIC_CAST_EXPR, type, expr);
5136 /* We don't know if it will or will not have side effects. */
5137 TREE_SIDE_EFFECTS (expr) = 1;
5138 return convert_from_reference (expr);
5141 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5142 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5143 if (TREE_CODE (type) != REFERENCE_TYPE
5144 && TREE_CODE (expr) == NOP_EXPR
5145 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5146 expr = TREE_OPERAND (expr, 0);
5148 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5152 error ("invalid static_cast from type %qT to type %qT",
5153 TREE_TYPE (expr), type);
5154 return error_mark_node;
5157 /* EXPR is an expression with member function or pointer-to-member
5158 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5159 not permitted by ISO C++, but we accept it in some modes. If we
5160 are not in one of those modes, issue a diagnostic. Return the
5161 converted expression. */
5164 convert_member_func_to_ptr (tree type, tree expr)
5169 intype = TREE_TYPE (expr);
5170 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5171 || TREE_CODE (intype) == METHOD_TYPE);
5173 if (pedantic || warn_pmf2ptr)
5174 pedwarn ("converting from %qT to %qT", intype, type);
5176 if (TREE_CODE (intype) == METHOD_TYPE)
5177 expr = build_addr_func (expr);
5178 else if (TREE_CODE (expr) == PTRMEM_CST)
5179 expr = build_address (PTRMEM_CST_MEMBER (expr));
5182 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5183 decl = build_address (decl);
5184 expr = get_member_function_from_ptrfunc (&decl, expr);
5187 return build_nop (type, expr);
5190 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5191 If C_CAST_P is true, this reinterpret cast is being done as part of
5192 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5193 indicate whether or not reinterpret_cast was valid. */
5196 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5201 /* Assume the cast is invalid. */
5205 if (type == error_mark_node || error_operand_p (expr))
5206 return error_mark_node;
5208 intype = TREE_TYPE (expr);
5210 /* Save casted types in the function's used types hash table. */
5211 used_types_insert (type);
5213 /* [expr.reinterpret.cast]
5214 An lvalue expression of type T1 can be cast to the type
5215 "reference to T2" if an expression of type "pointer to T1" can be
5216 explicitly converted to the type "pointer to T2" using a
5217 reinterpret_cast. */
5218 if (TREE_CODE (type) == REFERENCE_TYPE)
5220 if (! real_lvalue_p (expr))
5222 error ("invalid cast of an rvalue expression of type "
5225 return error_mark_node;
5228 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5229 "B" are related class types; the reinterpret_cast does not
5230 adjust the pointer. */
5231 if (TYPE_PTR_P (intype)
5232 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5233 COMPARE_BASE | COMPARE_DERIVED)))
5234 warning (0, "casting %qT to %qT does not dereference pointer",
5237 expr = build_unary_op (ADDR_EXPR, expr, 0);
5238 if (expr != error_mark_node)
5239 expr = build_reinterpret_cast_1
5240 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5242 if (expr != error_mark_node)
5243 expr = build_indirect_ref (expr, 0);
5247 /* As a G++ extension, we consider conversions from member
5248 functions, and pointers to member functions to
5249 pointer-to-function and pointer-to-void types. If
5250 -Wno-pmf-conversions has not been specified,
5251 convert_member_func_to_ptr will issue an error message. */
5252 if ((TYPE_PTRMEMFUNC_P (intype)
5253 || TREE_CODE (intype) == METHOD_TYPE)
5254 && TYPE_PTR_P (type)
5255 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5256 || VOID_TYPE_P (TREE_TYPE (type))))
5257 return convert_member_func_to_ptr (type, expr);
5259 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5260 array-to-pointer, and function-to-pointer conversions are
5262 expr = decay_conversion (expr);
5264 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5265 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5266 if (TREE_CODE (expr) == NOP_EXPR
5267 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5268 expr = TREE_OPERAND (expr, 0);
5270 if (error_operand_p (expr))
5271 return error_mark_node;
5273 intype = TREE_TYPE (expr);
5275 /* [expr.reinterpret.cast]
5276 A pointer can be converted to any integral type large enough to
5278 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5280 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5281 pedwarn ("cast from %qT to %qT loses precision",
5284 /* [expr.reinterpret.cast]
5285 A value of integral or enumeration type can be explicitly
5286 converted to a pointer. */
5287 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5290 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5291 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5292 return fold_if_not_in_template (build_nop (type, expr));
5293 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5294 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5299 check_for_casting_away_constness (intype, type, error,
5300 "reinterpret_cast");
5301 /* Warn about possible alignment problems. */
5302 if (STRICT_ALIGNMENT && warn_cast_align
5303 && !VOID_TYPE_P (type)
5304 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5305 && COMPLETE_TYPE_P (TREE_TYPE (type))
5306 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5307 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5308 warning (0, "cast from %qT to %qT increases required alignment of "
5312 /* We need to strip nops here, because the front end likes to
5313 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5315 if (warn_strict_aliasing <= 2)
5316 strict_aliasing_warning (intype, type, sexpr);
5318 return fold_if_not_in_template (build_nop (type, expr));
5320 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5321 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5324 /* Only issue a warning, as we have always supported this
5325 where possible, and it is necessary in some cases. DR 195
5326 addresses this issue, but as of 2004/10/26 is still in
5328 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5329 return fold_if_not_in_template (build_nop (type, expr));
5331 else if (TREE_CODE (type) == VECTOR_TYPE)
5332 return fold_if_not_in_template (convert_to_vector (type, expr));
5333 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5334 return fold_if_not_in_template (convert_to_integer (type, expr));
5339 error ("invalid cast from type %qT to type %qT", intype, type);
5340 return error_mark_node;
5343 return cp_convert (type, expr);
5347 build_reinterpret_cast (tree type, tree expr)
5349 if (type == error_mark_node || expr == error_mark_node)
5350 return error_mark_node;
5352 if (processing_template_decl)
5354 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5356 if (!TREE_SIDE_EFFECTS (t)
5357 && type_dependent_expression_p (expr))
5358 /* There might turn out to be side effects inside expr. */
5359 TREE_SIDE_EFFECTS (t) = 1;
5360 return convert_from_reference (t);
5363 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5367 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5368 return an appropriate expression. Otherwise, return
5369 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5370 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5371 performing a C-style cast, its value upon return will indicate
5372 whether or not the conversion succeeded. */
5375 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5379 tree reference_type;
5381 /* Callers are responsible for handling error_mark_node as a
5382 destination type. */
5383 gcc_assert (dst_type != error_mark_node);
5384 /* In a template, callers should be building syntactic
5385 representations of casts, not using this machinery. */
5386 gcc_assert (!processing_template_decl);
5388 /* Assume the conversion is invalid. */
5392 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5395 error ("invalid use of const_cast with type %qT, "
5396 "which is not a pointer, "
5397 "reference, nor a pointer-to-data-member type", dst_type);
5398 return error_mark_node;
5401 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5404 error ("invalid use of const_cast with type %qT, which is a pointer "
5405 "or reference to a function type", dst_type);
5406 return error_mark_node;
5409 /* Save casted types in the function's used types hash table. */
5410 used_types_insert (dst_type);
5412 src_type = TREE_TYPE (expr);
5413 /* Expressions do not really have reference types. */
5414 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5415 src_type = TREE_TYPE (src_type);
5417 /* [expr.const.cast]
5419 An lvalue of type T1 can be explicitly converted to an lvalue of
5420 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5421 types) if a pointer to T1 can be explicitly converted to the type
5422 pointer to T2 using a const_cast. */
5423 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5425 reference_type = dst_type;
5426 if (! real_lvalue_p (expr))
5429 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5430 src_type, dst_type);
5431 return error_mark_node;
5433 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5434 src_type = build_pointer_type (src_type);
5438 reference_type = NULL_TREE;
5439 /* If the destination type is not a reference type, the
5440 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5441 conversions are performed. */
5442 src_type = type_decays_to (src_type);
5443 if (src_type == error_mark_node)
5444 return error_mark_node;
5447 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5448 && comp_ptr_ttypes_const (dst_type, src_type))
5453 /* This cast is actually a C-style cast. Issue a warning if
5454 the user is making a potentially unsafe cast. */
5456 check_for_casting_away_constness (src_type, dst_type,
5462 expr = build_unary_op (ADDR_EXPR, expr, 0);
5463 expr = build_nop (reference_type, expr);
5464 return convert_from_reference (expr);
5468 expr = decay_conversion (expr);
5469 /* build_c_cast puts on a NOP_EXPR to make the result not an
5470 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5471 non-lvalue context. */
5472 if (TREE_CODE (expr) == NOP_EXPR
5473 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5474 expr = TREE_OPERAND (expr, 0);
5475 return build_nop (dst_type, expr);
5480 error ("invalid const_cast from type %qT to type %qT",
5481 src_type, dst_type);
5482 return error_mark_node;
5486 build_const_cast (tree type, tree expr)
5488 if (type == error_mark_node || error_operand_p (expr))
5489 return error_mark_node;
5491 if (processing_template_decl)
5493 tree t = build_min (CONST_CAST_EXPR, type, expr);
5495 if (!TREE_SIDE_EFFECTS (t)
5496 && type_dependent_expression_p (expr))
5497 /* There might turn out to be side effects inside expr. */
5498 TREE_SIDE_EFFECTS (t) = 1;
5499 return convert_from_reference (t);
5502 return build_const_cast_1 (type, expr, /*complain=*/true,
5506 /* Build an expression representing an explicit C-style cast to type
5507 TYPE of expression EXPR. */
5510 build_c_cast (tree type, tree expr)
5516 if (type == error_mark_node || error_operand_p (expr))
5517 return error_mark_node;
5519 if (processing_template_decl)
5521 tree t = build_min (CAST_EXPR, type,
5522 tree_cons (NULL_TREE, value, NULL_TREE));
5523 /* We don't know if it will or will not have side effects. */
5524 TREE_SIDE_EFFECTS (t) = 1;
5525 return convert_from_reference (t);
5528 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5529 'Class') should always be retained, because this information aids
5530 in method lookup. */
5531 if (objc_is_object_ptr (type)
5532 && objc_is_object_ptr (TREE_TYPE (expr)))
5533 return build_nop (type, expr);
5535 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5536 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5537 if (TREE_CODE (type) != REFERENCE_TYPE
5538 && TREE_CODE (value) == NOP_EXPR
5539 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5540 value = TREE_OPERAND (value, 0);
5542 if (TREE_CODE (type) == ARRAY_TYPE)
5544 /* Allow casting from T1* to T2[] because Cfront allows it.
5545 NIHCL uses it. It is not valid ISO C++ however. */
5546 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5548 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5549 type = build_pointer_type (TREE_TYPE (type));
5553 error ("ISO C++ forbids casting to an array type %qT", type);
5554 return error_mark_node;
5558 if (TREE_CODE (type) == FUNCTION_TYPE
5559 || TREE_CODE (type) == METHOD_TYPE)
5561 error ("invalid cast to function type %qT", type);
5562 return error_mark_node;
5565 /* A C-style cast can be a const_cast. */
5566 result = build_const_cast_1 (type, value, /*complain=*/false,
5571 /* Or a static cast. */
5572 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5574 /* Or a reinterpret_cast. */
5576 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5578 /* The static_cast or reinterpret_cast may be followed by a
5581 /* A valid cast may result in errors if, for example, a
5582 conversion to am ambiguous base class is required. */
5583 && !error_operand_p (result))
5587 /* Non-class rvalues always have cv-unqualified type. */
5588 if (!CLASS_TYPE_P (type))
5589 type = TYPE_MAIN_VARIANT (type);
5590 result_type = TREE_TYPE (result);
5591 if (!CLASS_TYPE_P (result_type))
5592 result_type = TYPE_MAIN_VARIANT (result_type);
5593 /* If the type of RESULT does not match TYPE, perform a
5594 const_cast to make it match. If the static_cast or
5595 reinterpret_cast succeeded, we will differ by at most
5596 cv-qualification, so the follow-on const_cast is guaranteed
5598 if (!same_type_p (non_reference (type), non_reference (result_type)))
5600 result = build_const_cast_1 (type, result, false, &valid_p);
5601 gcc_assert (valid_p);
5606 return error_mark_node;
5609 /* Build an assignment expression of lvalue LHS from value RHS.
5610 MODIFYCODE is the code for a binary operator that we use
5611 to combine the old value of LHS with RHS to get the new value.
5612 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5614 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5617 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5621 tree lhstype = TREE_TYPE (lhs);
5622 tree olhstype = lhstype;
5623 tree olhs = NULL_TREE;
5624 bool plain_assign = (modifycode == NOP_EXPR);
5626 /* Avoid duplicate error messages from operands that had errors. */
5627 if (error_operand_p (lhs) || error_operand_p (rhs))
5628 return error_mark_node;
5630 /* Handle control structure constructs used as "lvalues". */
5631 switch (TREE_CODE (lhs))
5633 /* Handle --foo = 5; as these are valid constructs in C++. */
5634 case PREDECREMENT_EXPR:
5635 case PREINCREMENT_EXPR:
5636 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5637 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5638 stabilize_reference (TREE_OPERAND (lhs, 0)),
5639 TREE_OPERAND (lhs, 1));
5640 return build2 (COMPOUND_EXPR, lhstype,
5642 build_modify_expr (TREE_OPERAND (lhs, 0),
5645 /* Handle (a, b) used as an "lvalue". */
5647 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5649 if (newrhs == error_mark_node)
5650 return error_mark_node;
5651 return build2 (COMPOUND_EXPR, lhstype,
5652 TREE_OPERAND (lhs, 0), newrhs);
5655 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5656 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5657 stabilize_reference (TREE_OPERAND (lhs, 0)),
5658 TREE_OPERAND (lhs, 1));
5659 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5660 if (newrhs == error_mark_node)
5661 return error_mark_node;
5662 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5666 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5667 when neither operand has side-effects. */
5668 if (!lvalue_or_else (lhs, lv_assign))
5669 return error_mark_node;
5671 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5672 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5674 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5675 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5677 TREE_OPERAND (lhs, 0),
5678 TREE_OPERAND (lhs, 1)),
5679 TREE_OPERAND (lhs, 0),
5680 TREE_OPERAND (lhs, 1));
5683 /* Handle (a ? b : c) used as an "lvalue". */
5686 /* Produce (a ? (b = rhs) : (c = rhs))
5687 except that the RHS goes through a save-expr
5688 so the code to compute it is only emitted once. */
5690 tree preeval = NULL_TREE;
5692 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5694 error ("void value not ignored as it ought to be");
5695 return error_mark_node;
5698 rhs = stabilize_expr (rhs, &preeval);
5700 /* Check this here to avoid odd errors when trying to convert
5701 a throw to the type of the COND_EXPR. */
5702 if (!lvalue_or_else (lhs, lv_assign))
5703 return error_mark_node;
5705 cond = build_conditional_expr
5706 (TREE_OPERAND (lhs, 0),
5707 build_modify_expr (TREE_OPERAND (lhs, 1),
5709 build_modify_expr (TREE_OPERAND (lhs, 2),
5712 if (cond == error_mark_node)
5714 /* Make sure the code to compute the rhs comes out
5715 before the split. */
5717 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5725 if (modifycode == INIT_EXPR)
5727 if (TREE_CODE (rhs) == CONSTRUCTOR)
5729 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5730 /* Call convert to generate an error; see PR 11063. */
5731 rhs = convert (lhstype, rhs);
5732 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5733 TREE_SIDE_EFFECTS (result) = 1;
5736 else if (! IS_AGGR_TYPE (lhstype))
5737 /* Do the default thing. */;
5740 result = build_special_member_call (lhs, complete_ctor_identifier,
5741 build_tree_list (NULL_TREE, rhs),
5742 lhstype, LOOKUP_NORMAL);
5743 if (result == NULL_TREE)
5744 return error_mark_node;
5750 lhs = require_complete_type (lhs);
5751 if (lhs == error_mark_node)
5752 return error_mark_node;
5754 if (modifycode == NOP_EXPR)
5756 /* `operator=' is not an inheritable operator. */
5757 if (! IS_AGGR_TYPE (lhstype))
5758 /* Do the default thing. */;
5761 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5762 lhs, rhs, make_node (NOP_EXPR),
5763 /*overloaded_p=*/NULL);
5764 if (result == NULL_TREE)
5765 return error_mark_node;
5772 /* A binary op has been requested. Combine the old LHS
5773 value with the RHS producing the value we should actually
5774 store into the LHS. */
5776 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5777 lhs = stabilize_reference (lhs);
5778 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5779 if (newrhs == error_mark_node)
5781 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5782 TREE_TYPE (lhs), TREE_TYPE (rhs));
5783 return error_mark_node;
5786 /* Now it looks like a plain assignment. */
5787 modifycode = NOP_EXPR;
5789 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5790 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5793 /* The left-hand side must be an lvalue. */
5794 if (!lvalue_or_else (lhs, lv_assign))
5795 return error_mark_node;
5797 /* Warn about modifying something that is `const'. Don't warn if
5798 this is initialization. */
5799 if (modifycode != INIT_EXPR
5800 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5801 /* Functions are not modifiable, even though they are
5803 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5804 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5805 /* If it's an aggregate and any field is const, then it is
5806 effectively const. */
5807 || (CLASS_TYPE_P (lhstype)
5808 && C_TYPE_FIELDS_READONLY (lhstype))))
5809 readonly_error (lhs, "assignment");
5811 /* If storing into a structure or union member, it has probably been
5812 given type `int'. Compute the type that would go with the actual
5813 amount of storage the member occupies. */
5815 if (TREE_CODE (lhs) == COMPONENT_REF
5816 && (TREE_CODE (lhstype) == INTEGER_TYPE
5817 || TREE_CODE (lhstype) == REAL_TYPE
5818 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5820 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5822 /* If storing in a field that is in actuality a short or narrower
5823 than one, we must store in the field in its actual type. */
5825 if (lhstype != TREE_TYPE (lhs))
5827 /* Avoid warnings converting integral types back into enums for
5829 if (TREE_CODE (lhstype) == INTEGER_TYPE
5830 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5832 if (TREE_SIDE_EFFECTS (lhs))
5833 lhs = stabilize_reference (lhs);
5836 lhs = copy_node (lhs);
5837 TREE_TYPE (lhs) = lhstype;
5841 /* Convert new value to destination type. */
5843 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5847 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5848 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5850 error ("incompatible types in assignment of %qT to %qT",
5851 TREE_TYPE (rhs), lhstype);
5852 return error_mark_node;
5855 /* Allow array assignment in compiler-generated code. */
5856 if (! DECL_ARTIFICIAL (current_function_decl))
5858 /* This routine is used for both initialization and assignment.
5859 Make sure the diagnostic message differentiates the context. */
5860 if (modifycode == INIT_EXPR)
5861 error ("array used as initializer");
5863 error ("invalid array assignment");
5864 return error_mark_node;
5867 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5868 ? 1 + (modifycode != INIT_EXPR): 0;
5869 return build_vec_init (lhs, NULL_TREE, newrhs,
5870 /*explicit_default_init_p=*/false,
5874 if (modifycode == INIT_EXPR)
5875 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5876 "initialization", NULL_TREE, 0);
5879 /* Avoid warnings on enum bit fields. */
5880 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5881 && TREE_CODE (lhstype) == INTEGER_TYPE)
5883 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5885 newrhs = convert_force (lhstype, newrhs, 0);
5888 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5890 if (TREE_CODE (newrhs) == CALL_EXPR
5891 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5892 newrhs = build_cplus_new (lhstype, newrhs);
5894 /* Can't initialize directly from a TARGET_EXPR, since that would
5895 cause the lhs to be constructed twice, and possibly result in
5896 accidental self-initialization. So we force the TARGET_EXPR to be
5897 expanded without a target. */
5898 if (TREE_CODE (newrhs) == TARGET_EXPR)
5899 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5900 TREE_OPERAND (newrhs, 0));
5903 if (newrhs == error_mark_node)
5904 return error_mark_node;
5906 if (c_dialect_objc () && flag_objc_gc)
5908 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5914 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5915 lhstype, lhs, newrhs);
5917 TREE_SIDE_EFFECTS (result) = 1;
5919 TREE_NO_WARNING (result) = 1;
5921 /* If we got the LHS in a different type for storing in,
5922 convert the result back to the nominal type of LHS
5923 so that the value we return always has the same type
5924 as the LHS argument. */
5926 if (olhstype == TREE_TYPE (result))
5930 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5931 TREE_NO_WARNING (result) = 1;
5934 return convert_for_assignment (olhstype, result, "assignment",
5939 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5941 if (processing_template_decl)
5942 return build_min_nt (MODOP_EXPR, lhs,
5943 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5945 if (modifycode != NOP_EXPR)
5947 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5948 make_node (modifycode),
5949 /*overloaded_p=*/NULL);
5952 TREE_NO_WARNING (rval) = 1;
5956 return build_modify_expr (lhs, modifycode, rhs);
5960 /* Get difference in deltas for different pointer to member function
5961 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5962 the conversion is invalid, the constant is zero. If
5963 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5964 If C_CAST_P is true this conversion is taking place as part of a
5967 Note that the naming of FROM and TO is kind of backwards; the return
5968 value is what we add to a TO in order to get a FROM. They are named
5969 this way because we call this function to find out how to convert from
5970 a pointer to member of FROM to a pointer to member of TO. */
5973 get_delta_difference (tree from, tree to,
5974 bool allow_inverse_p,
5981 /* Assume no conversion is required. */
5982 result = integer_zero_node;
5983 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5984 if (kind == bk_inaccessible || kind == bk_ambig)
5985 error (" in pointer to member function conversion");
5988 if (kind != bk_via_virtual)
5989 result = BINFO_OFFSET (binfo);
5992 tree virt_binfo = binfo_from_vbase (binfo);
5994 /* This is a reinterpret cast, we choose to do nothing. */
5995 if (allow_inverse_p)
5996 warning (0, "pointer to member cast via virtual base %qT",
5997 BINFO_TYPE (virt_binfo));
5999 error ("pointer to member conversion via virtual base %qT",
6000 BINFO_TYPE (virt_binfo));
6003 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
6004 /* Pointer to member of incomplete class is permitted*/;
6005 else if (!allow_inverse_p)
6007 error_not_base_type (from, to);
6008 error (" in pointer to member conversion");
6012 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
6015 if (kind != bk_via_virtual)
6016 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
6019 /* This is a reinterpret cast, we choose to do nothing. */
6020 tree virt_binfo = binfo_from_vbase (binfo);
6022 warning (0, "pointer to member cast via virtual base %qT",
6023 BINFO_TYPE (virt_binfo));
6028 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6032 /* Return a constructor for the pointer-to-member-function TYPE using
6033 the other components as specified. */
6036 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6041 VEC(constructor_elt, gc) *v;
6043 /* Pull the FIELD_DECLs out of the type. */
6044 pfn_field = TYPE_FIELDS (type);
6045 delta_field = TREE_CHAIN (pfn_field);
6047 /* Make sure DELTA has the type we want. */
6048 delta = convert_and_check (delta_type_node, delta);
6050 /* Finish creating the initializer. */
6051 v = VEC_alloc(constructor_elt, gc, 2);
6052 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6053 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6054 u = build_constructor (type, v);
6055 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6056 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6057 TREE_STATIC (u) = (TREE_CONSTANT (u)
6058 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6060 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6065 /* Build a constructor for a pointer to member function. It can be
6066 used to initialize global variables, local variable, or used
6067 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6070 If FORCE is nonzero, then force this conversion, even if
6071 we would rather not do it. Usually set when using an explicit
6072 cast. A C-style cast is being processed iff C_CAST_P is true.
6074 Return error_mark_node, if something goes wrong. */
6077 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6083 if (error_operand_p (pfn))
6084 return error_mark_node;
6086 pfn_type = TREE_TYPE (pfn);
6087 to_type = build_ptrmemfunc_type (type);
6089 /* Handle multiple conversions of pointer to member functions. */
6090 if (TYPE_PTRMEMFUNC_P (pfn_type))
6092 tree delta = NULL_TREE;
6093 tree npfn = NULL_TREE;
6097 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6098 error ("invalid conversion to type %qT from type %qT",
6101 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6102 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6106 /* We don't have to do any conversion to convert a
6107 pointer-to-member to its own type. But, we don't want to
6108 just return a PTRMEM_CST if there's an explicit cast; that
6109 cast should make the expression an invalid template argument. */
6110 if (TREE_CODE (pfn) != PTRMEM_CST)
6112 if (same_type_p (to_type, pfn_type))
6114 else if (integer_zerop (n))
6115 return build_reinterpret_cast (to_type, pfn);
6118 if (TREE_SIDE_EFFECTS (pfn))
6119 pfn = save_expr (pfn);
6121 /* Obtain the function pointer and the current DELTA. */
6122 if (TREE_CODE (pfn) == PTRMEM_CST)
6123 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6126 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6127 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6130 /* Just adjust the DELTA field. */
6131 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6132 (TREE_TYPE (delta), ptrdiff_type_node));
6133 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6134 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6135 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6136 return build_ptrmemfunc1 (to_type, delta, npfn);
6139 /* Handle null pointer to member function conversions. */
6140 if (integer_zerop (pfn))
6142 pfn = build_c_cast (type, integer_zero_node);
6143 return build_ptrmemfunc1 (to_type,
6148 if (type_unknown_p (pfn))
6149 return instantiate_type (type, pfn, tf_warning_or_error);
6151 fn = TREE_OPERAND (pfn, 0);
6152 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6153 /* In a template, we will have preserved the
6155 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6156 return make_ptrmem_cst (to_type, fn);
6159 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6162 ??? There is no consistency as to the types returned for the above
6163 values. Some code acts as if it were a sizetype and some as if it were
6164 integer_type_node. */
6167 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6169 tree type = TREE_TYPE (cst);
6170 tree fn = PTRMEM_CST_MEMBER (cst);
6171 tree ptr_class, fn_class;
6173 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6175 /* The class that the function belongs to. */
6176 fn_class = DECL_CONTEXT (fn);
6178 /* The class that we're creating a pointer to member of. */
6179 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6181 /* First, calculate the adjustment to the function's class. */
6182 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6185 if (!DECL_VIRTUAL_P (fn))
6186 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6189 /* If we're dealing with a virtual function, we have to adjust 'this'
6190 again, to point to the base which provides the vtable entry for
6191 fn; the call will do the opposite adjustment. */
6192 tree orig_class = DECL_CONTEXT (fn);
6193 tree binfo = binfo_or_else (orig_class, fn_class);
6194 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6195 *delta, BINFO_OFFSET (binfo));
6196 *delta = fold_if_not_in_template (*delta);
6198 /* We set PFN to the vtable offset at which the function can be
6199 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6200 case delta is shifted left, and then incremented). */
6201 *pfn = DECL_VINDEX (fn);
6202 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6203 TYPE_SIZE_UNIT (vtable_entry_type));
6204 *pfn = fold_if_not_in_template (*pfn);
6206 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6208 case ptrmemfunc_vbit_in_pfn:
6209 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6211 *pfn = fold_if_not_in_template (*pfn);
6214 case ptrmemfunc_vbit_in_delta:
6215 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6216 *delta, integer_one_node);
6217 *delta = fold_if_not_in_template (*delta);
6218 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6219 *delta, integer_one_node);
6220 *delta = fold_if_not_in_template (*delta);
6227 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6228 *pfn = fold_if_not_in_template (*pfn);
6232 /* Return an expression for PFN from the pointer-to-member function
6236 pfn_from_ptrmemfunc (tree t)
6238 if (TREE_CODE (t) == PTRMEM_CST)
6243 expand_ptrmemfunc_cst (t, &delta, &pfn);
6248 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6251 /* Convert value RHS to type TYPE as preparation for an assignment to
6252 an lvalue of type TYPE. ERRTYPE is a string to use in error
6253 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6254 are doing the conversion in order to pass the PARMNUMth argument of
6258 convert_for_assignment (tree type, tree rhs,
6259 const char *errtype, tree fndecl, int parmnum)
6262 enum tree_code coder;
6264 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6265 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6266 rhs = TREE_OPERAND (rhs, 0);
6268 rhstype = TREE_TYPE (rhs);
6269 coder = TREE_CODE (rhstype);
6271 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6272 && vector_types_convertible_p (type, rhstype, true))
6273 return convert (type, rhs);
6275 if (rhs == error_mark_node || rhstype == error_mark_node)
6276 return error_mark_node;
6277 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6278 return error_mark_node;
6280 /* The RHS of an assignment cannot have void type. */
6281 if (coder == VOID_TYPE)
6283 error ("void value not ignored as it ought to be");
6284 return error_mark_node;
6287 /* Simplify the RHS if possible. */
6288 if (TREE_CODE (rhs) == CONST_DECL)
6289 rhs = DECL_INITIAL (rhs);
6291 if (c_dialect_objc ())
6294 tree rname = fndecl;
6296 if (!strcmp (errtype, "assignment"))
6298 else if (!strcmp (errtype, "initialization"))
6302 tree selector = objc_message_selector ();
6306 if (selector && parmno > 1)
6313 if (objc_compare_types (type, rhstype, parmno, rname))
6314 return convert (type, rhs);
6319 The expression is implicitly converted (clause _conv_) to the
6320 cv-unqualified type of the left operand.
6322 We allow bad conversions here because by the time we get to this point
6323 we are committed to doing the conversion. If we end up doing a bad
6324 conversion, convert_like will complain. */
6325 if (!can_convert_arg_bad (type, rhstype, rhs))
6327 /* When -Wno-pmf-conversions is use, we just silently allow
6328 conversions from pointers-to-members to plain pointers. If
6329 the conversion doesn't work, cp_convert will complain. */
6331 && TYPE_PTR_P (type)
6332 && TYPE_PTRMEMFUNC_P (rhstype))
6333 rhs = cp_convert (strip_top_quals (type), rhs);
6336 /* If the right-hand side has unknown type, then it is an
6337 overloaded function. Call instantiate_type to get error
6339 if (rhstype == unknown_type_node)
6340 instantiate_type (type, rhs, tf_warning_or_error);
6342 error ("cannot convert %qT to %qT for argument %qP to %qD",
6343 rhstype, type, parmnum, fndecl);
6345 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6346 return error_mark_node;
6349 if (warn_missing_format_attribute)
6351 const enum tree_code codel = TREE_CODE (type);
6352 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6354 && check_missing_format_attribute (type, rhstype))
6355 warning (OPT_Wmissing_format_attribute,
6356 "%s might be a candidate for a format attribute",
6360 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6362 if (warn_parentheses
6363 && type == boolean_type_node
6364 && TREE_CODE (rhs) == MODIFY_EXPR
6365 && !TREE_NO_WARNING (rhs)
6366 && TREE_TYPE (rhs) != boolean_type_node)
6368 warning (OPT_Wparentheses,
6369 "suggest parentheses around assignment used as truth value");
6370 TREE_NO_WARNING (rhs) = 1;
6373 return perform_implicit_conversion (strip_top_quals (type), rhs);
6376 /* Convert RHS to be of type TYPE.
6377 If EXP is nonzero, it is the target of the initialization.
6378 ERRTYPE is a string to use in error messages.
6380 Two major differences between the behavior of
6381 `convert_for_assignment' and `convert_for_initialization'
6382 are that references are bashed in the former, while
6383 copied in the latter, and aggregates are assigned in
6384 the former (operator=) while initialized in the
6387 If using constructor make sure no conversion operator exists, if one does
6388 exist, an ambiguity exists.
6390 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6393 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6394 const char *errtype, tree fndecl, int parmnum)
6396 enum tree_code codel = TREE_CODE (type);
6398 enum tree_code coder;
6400 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6401 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6402 if (TREE_CODE (rhs) == NOP_EXPR
6403 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6404 && codel != REFERENCE_TYPE)
6405 rhs = TREE_OPERAND (rhs, 0);
6407 if (type == error_mark_node
6408 || rhs == error_mark_node
6409 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6410 return error_mark_node;
6412 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6413 && TREE_CODE (type) != ARRAY_TYPE
6414 && (TREE_CODE (type) != REFERENCE_TYPE
6415 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6416 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6417 && (TREE_CODE (type) != REFERENCE_TYPE
6418 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6419 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6420 rhs = decay_conversion (rhs);
6422 rhstype = TREE_TYPE (rhs);
6423 coder = TREE_CODE (rhstype);
6425 if (coder == ERROR_MARK)
6426 return error_mark_node;
6428 /* We accept references to incomplete types, so we can
6429 return here before checking if RHS is of complete type. */
6431 if (codel == REFERENCE_TYPE)
6433 /* This should eventually happen in convert_arguments. */
6434 int savew = 0, savee = 0;
6437 savew = warningcount, savee = errorcount;
6438 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6442 if (warningcount > savew)
6443 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6444 else if (errorcount > savee)
6445 error ("in passing argument %P of %q+D", parmnum, fndecl);
6451 exp = require_complete_type (exp);
6452 if (exp == error_mark_node)
6453 return error_mark_node;
6455 rhstype = non_reference (rhstype);
6457 type = complete_type (type);
6459 if (IS_AGGR_TYPE (type))
6460 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6462 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6465 /* If RETVAL is the address of, or a reference to, a local variable or
6466 temporary give an appropriate warning. */
6469 maybe_warn_about_returning_address_of_local (tree retval)
6471 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6472 tree whats_returned = retval;
6476 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6477 whats_returned = TREE_OPERAND (whats_returned, 1);
6478 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6479 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6480 || TREE_CODE (whats_returned) == NOP_EXPR)
6481 whats_returned = TREE_OPERAND (whats_returned, 0);
6486 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6488 whats_returned = TREE_OPERAND (whats_returned, 0);
6490 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6492 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6493 || TREE_CODE (whats_returned) == TARGET_EXPR)
6495 warning (0, "returning reference to temporary");
6498 if (TREE_CODE (whats_returned) == VAR_DECL
6499 && DECL_NAME (whats_returned)
6500 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6502 warning (0, "reference to non-lvalue returned");
6507 while (TREE_CODE (whats_returned) == COMPONENT_REF
6508 || TREE_CODE (whats_returned) == ARRAY_REF)
6509 whats_returned = TREE_OPERAND (whats_returned, 0);
6511 if (DECL_P (whats_returned)
6512 && DECL_NAME (whats_returned)
6513 && DECL_FUNCTION_SCOPE_P (whats_returned)
6514 && !(TREE_STATIC (whats_returned)
6515 || TREE_PUBLIC (whats_returned)))
6517 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6518 warning (0, "reference to local variable %q+D returned",
6521 warning (0, "address of local variable %q+D returned",
6527 /* Check that returning RETVAL from the current function is valid.
6528 Return an expression explicitly showing all conversions required to
6529 change RETVAL into the function return type, and to assign it to
6530 the DECL_RESULT for the function. Set *NO_WARNING to true if
6531 code reaches end of non-void function warning shouldn't be issued
6532 on this RETURN_EXPR. */
6535 check_return_expr (tree retval, bool *no_warning)
6538 /* The type actually returned by the function, after any
6541 int fn_returns_value_p;
6542 bool named_return_value_okay_p;
6544 *no_warning = false;
6546 /* A `volatile' function is one that isn't supposed to return, ever.
6547 (This is a G++ extension, used to get better code for functions
6548 that call the `volatile' function.) */
6549 if (TREE_THIS_VOLATILE (current_function_decl))
6550 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6552 /* Check for various simple errors. */
6553 if (DECL_DESTRUCTOR_P (current_function_decl))
6556 error ("returning a value from a destructor");
6559 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6561 if (in_function_try_handler)
6562 /* If a return statement appears in a handler of the
6563 function-try-block of a constructor, the program is ill-formed. */
6564 error ("cannot return from a handler of a function-try-block of a constructor");
6566 /* You can't return a value from a constructor. */
6567 error ("returning a value from a constructor");
6571 if (processing_template_decl)
6573 current_function_returns_value = 1;
6574 check_for_bare_parameter_packs (retval);
6578 /* When no explicit return-value is given in a function with a named
6579 return value, the named return value is used. */
6580 result = DECL_RESULT (current_function_decl);
6581 valtype = TREE_TYPE (result);
6582 gcc_assert (valtype != NULL_TREE);
6583 fn_returns_value_p = !VOID_TYPE_P (valtype);
6584 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6587 /* Check for a return statement with no return value in a function
6588 that's supposed to return a value. */
6589 if (!retval && fn_returns_value_p)
6591 pedwarn ("return-statement with no value, in function returning %qT",
6593 /* Clear this, so finish_function won't say that we reach the
6594 end of a non-void function (which we don't, we gave a
6596 current_function_returns_null = 0;
6597 /* And signal caller that TREE_NO_WARNING should be set on the
6598 RETURN_EXPR to avoid control reaches end of non-void function
6599 warnings in tree-cfg.c. */
6602 /* Check for a return statement with a value in a function that
6603 isn't supposed to return a value. */
6604 else if (retval && !fn_returns_value_p)
6606 if (VOID_TYPE_P (TREE_TYPE (retval)))
6607 /* You can return a `void' value from a function of `void'
6608 type. In that case, we have to evaluate the expression for
6609 its side-effects. */
6610 finish_expr_stmt (retval);
6612 pedwarn ("return-statement with a value, in function "
6613 "returning 'void'");
6615 current_function_returns_null = 1;
6617 /* There's really no value to return, after all. */
6621 /* Remember that this function can sometimes return without a
6623 current_function_returns_null = 1;
6625 /* Remember that this function did return a value. */
6626 current_function_returns_value = 1;
6628 /* Check for erroneous operands -- but after giving ourselves a
6629 chance to provide an error about returning a value from a void
6631 if (error_operand_p (retval))
6633 current_function_return_value = error_mark_node;
6634 return error_mark_node;
6637 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6638 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6639 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6640 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6642 && null_ptr_cst_p (retval))
6643 warning (0, "%<operator new%> must not return NULL unless it is "
6644 "declared %<throw()%> (or -fcheck-new is in effect)");
6646 /* Effective C++ rule 15. See also start_function. */
6648 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6652 /* The function return type must be a reference to the current
6654 if (TREE_CODE (valtype) == REFERENCE_TYPE
6655 && same_type_ignoring_top_level_qualifiers_p
6656 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6658 /* Returning '*this' is obviously OK. */
6659 if (retval == current_class_ref)
6661 /* If we are calling a function whose return type is the same of
6662 the current class reference, it is ok. */
6663 else if (TREE_CODE (retval) == INDIRECT_REF
6664 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6669 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6672 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6674 [...] For a function with a class return type, if the expression
6675 in the return statement is the name of a local object, and the cv-
6676 unqualified type of the local object is the same as the function
6677 return type, an implementation is permitted to omit creating the tem-
6678 porary object to hold the function return value [...]
6680 So, if this is a value-returning function that always returns the same
6681 local variable, remember it.
6683 It might be nice to be more flexible, and choose the first suitable
6684 variable even if the function sometimes returns something else, but
6685 then we run the risk of clobbering the variable we chose if the other
6686 returned expression uses the chosen variable somehow. And people expect
6687 this restriction, anyway. (jason 2000-11-19)
6689 See finish_function and finalize_nrv for the rest of this optimization. */
6691 named_return_value_okay_p =
6692 (retval != NULL_TREE
6693 /* Must be a local, automatic variable. */
6694 && TREE_CODE (retval) == VAR_DECL
6695 && DECL_CONTEXT (retval) == current_function_decl
6696 && ! TREE_STATIC (retval)
6697 && (DECL_ALIGN (retval)
6698 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6699 /* The cv-unqualified type of the returned value must be the
6700 same as the cv-unqualified return type of the
6702 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
6704 (TREE_TYPE (TREE_TYPE (current_function_decl))))));
6706 if (fn_returns_value_p && flag_elide_constructors)
6708 if (named_return_value_okay_p
6709 && (current_function_return_value == NULL_TREE
6710 || current_function_return_value == retval))
6711 current_function_return_value = retval;
6713 current_function_return_value = error_mark_node;
6716 /* We don't need to do any conversions when there's nothing being
6721 /* Do any required conversions. */
6722 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6723 /* No conversions are required. */
6727 /* The type the function is declared to return. */
6728 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6729 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
6731 /* The functype's return type will have been set to void, if it
6732 was an incomplete type. Just treat this as 'return;' */
6733 if (VOID_TYPE_P (functype))
6734 return error_mark_node;
6736 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
6737 treated as an rvalue for the purposes of overload resolution to
6738 favor move constructors over copy constructors. */
6739 if ((cxx_dialect != cxx98)
6740 && named_return_value_okay_p
6741 /* The variable must not have the `volatile' qualifier. */
6742 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
6743 /* The return type must be a class type. */
6744 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
6745 flags = flags | LOOKUP_PREFER_RVALUE;
6747 /* First convert the value to the function's return type, then
6748 to the type of return value's location to handle the
6749 case that functype is smaller than the valtype. */
6750 retval = convert_for_initialization
6751 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0);
6752 retval = convert (valtype, retval);
6754 /* If the conversion failed, treat this just like `return;'. */
6755 if (retval == error_mark_node)
6757 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6758 else if (! current_function_returns_struct
6759 && TREE_CODE (retval) == TARGET_EXPR
6760 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6761 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6762 TREE_OPERAND (retval, 0));
6764 maybe_warn_about_returning_address_of_local (retval);
6767 /* Actually copy the value returned into the appropriate location. */
6768 if (retval && retval != result)
6769 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6775 /* Returns nonzero if the pointer-type FROM can be converted to the
6776 pointer-type TO via a qualification conversion. If CONSTP is -1,
6777 then we return nonzero if the pointers are similar, and the
6778 cv-qualification signature of FROM is a proper subset of that of TO.
6780 If CONSTP is positive, then all outer pointers have been
6784 comp_ptr_ttypes_real (tree to, tree from, int constp)
6786 bool to_more_cv_qualified = false;
6788 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6790 if (TREE_CODE (to) != TREE_CODE (from))
6793 if (TREE_CODE (from) == OFFSET_TYPE
6794 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6795 TYPE_OFFSET_BASETYPE (to)))
6798 /* Const and volatile mean something different for function types,
6799 so the usual checks are not appropriate. */
6800 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6802 /* In Objective-C++, some types may have been 'volatilized' by
6803 the compiler for EH; when comparing them here, the volatile
6804 qualification must be ignored. */
6805 bool objc_quals_match = objc_type_quals_match (to, from);
6807 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6810 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6814 to_more_cv_qualified = true;
6818 constp &= TYPE_READONLY (to);
6821 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6822 return ((constp >= 0 || to_more_cv_qualified)
6823 && same_type_ignoring_top_level_qualifiers_p (to, from));
6827 /* When comparing, say, char ** to char const **, this function takes
6828 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6829 types to this function. */
6832 comp_ptr_ttypes (tree to, tree from)
6834 return comp_ptr_ttypes_real (to, from, 1);
6837 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6838 type or inheritance-related types, regardless of cv-quals. */
6841 ptr_reasonably_similar (tree to, tree from)
6843 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6845 /* Any target type is similar enough to void. */
6846 if (TREE_CODE (to) == VOID_TYPE
6847 || TREE_CODE (from) == VOID_TYPE)
6850 if (TREE_CODE (to) != TREE_CODE (from))
6853 if (TREE_CODE (from) == OFFSET_TYPE
6854 && comptypes (TYPE_OFFSET_BASETYPE (to),
6855 TYPE_OFFSET_BASETYPE (from),
6856 COMPARE_BASE | COMPARE_DERIVED))
6859 if (TREE_CODE (to) == VECTOR_TYPE
6860 && vector_types_convertible_p (to, from, false))
6863 if (TREE_CODE (to) == INTEGER_TYPE
6864 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6867 if (TREE_CODE (to) == FUNCTION_TYPE)
6870 if (TREE_CODE (to) != POINTER_TYPE)
6872 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6873 COMPARE_BASE | COMPARE_DERIVED);
6877 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6878 pointer-to-member types) are the same, ignoring cv-qualification at
6882 comp_ptr_ttypes_const (tree to, tree from)
6884 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6886 if (TREE_CODE (to) != TREE_CODE (from))
6889 if (TREE_CODE (from) == OFFSET_TYPE
6890 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6891 TYPE_OFFSET_BASETYPE (to)))
6894 if (TREE_CODE (to) != POINTER_TYPE)
6895 return same_type_ignoring_top_level_qualifiers_p (to, from);
6899 /* Returns the type qualifiers for this type, including the qualifiers on the
6900 elements for an array type. */
6903 cp_type_quals (tree type)
6905 type = strip_array_types (type);
6906 if (type == error_mark_node)
6907 return TYPE_UNQUALIFIED;
6908 return TYPE_QUALS (type);
6911 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6915 cp_type_readonly (tree type)
6917 type = strip_array_types (type);
6918 return TYPE_READONLY (type);
6921 /* Returns nonzero if the TYPE contains a mutable member. */
6924 cp_has_mutable_p (tree type)
6926 type = strip_array_types (type);
6928 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6931 /* Apply the TYPE_QUALS to the new DECL. */
6933 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6935 tree type = TREE_TYPE (decl);
6937 if (type == error_mark_node)
6940 if (TREE_CODE (type) == FUNCTION_TYPE
6941 && type_quals != TYPE_UNQUALIFIED)
6943 /* This was an error in C++98 (cv-qualifiers cannot be added to
6944 a function type), but DR 295 makes the code well-formed by
6945 dropping the extra qualifiers. */
6948 tree bad_type = build_qualified_type (type, type_quals);
6949 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6953 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6957 /* Avoid setting TREE_READONLY incorrectly. */
6958 if (/* If the object has a constructor, the constructor may modify
6960 TYPE_NEEDS_CONSTRUCTING (type)
6961 /* If the type isn't complete, we don't know yet if it will need
6963 || !COMPLETE_TYPE_P (type)
6964 /* If the type has a mutable component, that component might be
6966 || TYPE_HAS_MUTABLE_P (type))
6967 type_quals &= ~TYPE_QUAL_CONST;
6969 c_apply_type_quals_to_decl (type_quals, decl);
6972 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6973 exemplar types such that casting T1 to T2 is casting away constness
6974 if and only if there is no implicit conversion from T1 to T2. */
6977 casts_away_constness_r (tree *t1, tree *t2)
6982 /* [expr.const.cast]
6984 For multi-level pointer to members and multi-level mixed pointers
6985 and pointers to members (conv.qual), the "member" aspect of a
6986 pointer to member level is ignored when determining if a const
6987 cv-qualifier has been cast away. */
6988 /* [expr.const.cast]
6990 For two pointer types:
6992 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6993 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6996 casting from X1 to X2 casts away constness if, for a non-pointer
6997 type T there does not exist an implicit conversion (clause
7000 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7004 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7005 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7006 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7008 *t1 = cp_build_qualified_type (void_type_node,
7009 cp_type_quals (*t1));
7010 *t2 = cp_build_qualified_type (void_type_node,
7011 cp_type_quals (*t2));
7015 quals1 = cp_type_quals (*t1);
7016 quals2 = cp_type_quals (*t2);
7018 if (TYPE_PTRMEM_P (*t1))
7019 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7021 *t1 = TREE_TYPE (*t1);
7022 if (TYPE_PTRMEM_P (*t2))
7023 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7025 *t2 = TREE_TYPE (*t2);
7027 casts_away_constness_r (t1, t2);
7028 *t1 = build_pointer_type (*t1);
7029 *t2 = build_pointer_type (*t2);
7030 *t1 = cp_build_qualified_type (*t1, quals1);
7031 *t2 = cp_build_qualified_type (*t2, quals2);
7034 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7038 casts_away_constness (tree t1, tree t2)
7040 if (TREE_CODE (t2) == REFERENCE_TYPE)
7042 /* [expr.const.cast]
7044 Casting from an lvalue of type T1 to an lvalue of type T2
7045 using a reference cast casts away constness if a cast from an
7046 rvalue of type "pointer to T1" to the type "pointer to T2"
7047 casts away constness. */
7048 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7049 return casts_away_constness (build_pointer_type (t1),
7050 build_pointer_type (TREE_TYPE (t2)));
7053 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7054 /* [expr.const.cast]
7056 Casting from an rvalue of type "pointer to data member of X
7057 of type T1" to the type "pointer to data member of Y of type
7058 T2" casts away constness if a cast from an rvalue of type
7059 "pointer to T1" to the type "pointer to T2" casts away
7061 return casts_away_constness
7062 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7063 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7065 /* Casting away constness is only something that makes sense for
7066 pointer or reference types. */
7067 if (TREE_CODE (t1) != POINTER_TYPE
7068 || TREE_CODE (t2) != POINTER_TYPE)
7071 /* Top-level qualifiers don't matter. */
7072 t1 = TYPE_MAIN_VARIANT (t1);
7073 t2 = TYPE_MAIN_VARIANT (t2);
7074 casts_away_constness_r (&t1, &t2);
7075 if (!can_convert (t2, t1))
7081 /* If T is a REFERENCE_TYPE return the type to which T refers.
7082 Otherwise, return T itself. */
7085 non_reference (tree t)
7087 if (TREE_CODE (t) == REFERENCE_TYPE)
7093 /* Return nonzero if REF is an lvalue valid for this language;
7094 otherwise, print an error message and return zero. USE says
7095 how the lvalue is being used and so selects the error message. */
7098 lvalue_or_else (tree ref, enum lvalue_use use)
7100 int win = lvalue_p (ref);