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 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
48 static tree pfn_from_ptrmemfunc (tree);
49 static tree delta_from_ptrmemfunc (tree);
50 static tree convert_for_assignment (tree, tree, const char *, tree, int);
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 (const_tree, const_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 (const_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 = cp_build_reference_type (target, TYPE_REF_IS_RVALUE (t1));
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 (const_tree t1, const_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 (const_tree t1, const_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));
1084 if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1)
1085 != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2)
1086 || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1),
1087 DECLTYPE_TYPE_EXPR (t2)))
1095 /* If we get here, we know that from a target independent POV the
1096 types are the same. Make sure the target attributes are also
1098 return targetm.comp_type_attributes (t1, t2);
1101 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1102 is a bitwise-or of the COMPARE_* flags. */
1105 comptypes (tree t1, tree t2, int strict)
1107 if (strict == COMPARE_STRICT)
1112 if (t1 == error_mark_node || t2 == error_mark_node)
1115 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1116 /* At least one of the types requires structural equality, so
1117 perform a deep check. */
1118 return structural_comptypes (t1, t2, strict);
1120 #ifdef ENABLE_CHECKING
1121 if (USE_CANONICAL_TYPES)
1123 bool result = structural_comptypes (t1, t2, strict);
1125 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1126 /* The two types are structurally equivalent, but their
1127 canonical types were different. This is a failure of the
1128 canonical type propagation code.*/
1130 ("canonical types differ for identical types %T and %T",
1132 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1133 /* Two types are structurally different, but the canonical
1134 types are the same. This means we were over-eager in
1135 assigning canonical types. */
1137 ("same canonical type node for different types %T and %T",
1143 if (USE_CANONICAL_TYPES)
1144 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1147 return structural_comptypes (t1, t2, strict);
1149 else if (strict == COMPARE_STRUCTURAL)
1150 return structural_comptypes (t1, t2, COMPARE_STRICT);
1152 return structural_comptypes (t1, t2, strict);
1155 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1158 at_least_as_qualified_p (const_tree type1, const_tree type2)
1160 int q1 = cp_type_quals (type1);
1161 int q2 = cp_type_quals (type2);
1163 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1164 return (q1 & q2) == q2;
1167 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1168 more cv-qualified that TYPE1, and 0 otherwise. */
1171 comp_cv_qualification (const_tree type1, const_tree type2)
1173 int q1 = cp_type_quals (type1);
1174 int q2 = cp_type_quals (type2);
1179 if ((q1 & q2) == q2)
1181 else if ((q1 & q2) == q1)
1187 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1188 subset of the cv-qualification signature of TYPE2, and the types
1189 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1192 comp_cv_qual_signature (tree type1, tree type2)
1194 if (comp_ptr_ttypes_real (type2, type1, -1))
1196 else if (comp_ptr_ttypes_real (type1, type2, -1))
1202 /* Subroutines of `comptypes'. */
1204 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1205 equivalent in the sense that functions with those parameter types
1206 can have equivalent types. The two lists must be equivalent,
1207 element by element. */
1210 compparms (const_tree parms1, const_tree parms2)
1214 /* An unspecified parmlist matches any specified parmlist
1215 whose argument types don't need default promotions. */
1217 for (t1 = parms1, t2 = parms2;
1219 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1221 /* If one parmlist is shorter than the other,
1222 they fail to match. */
1225 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1232 /* Process a sizeof or alignof expression where the operand is a
1236 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1241 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1242 if (type == error_mark_node)
1243 return error_mark_node;
1245 type = non_reference (type);
1246 if (TREE_CODE (type) == METHOD_TYPE)
1248 if (complain && (pedantic || warn_pointer_arith))
1249 pedwarn ("invalid application of %qs to a member function",
1250 operator_name_info[(int) op].name);
1251 value = size_one_node;
1254 dependent_p = dependent_type_p (type);
1256 complete_type (type);
1258 /* VLA types will have a non-constant size. In the body of an
1259 uninstantiated template, we don't need to try to compute the
1260 value, because the sizeof expression is not an integral
1261 constant expression in that case. And, if we do try to
1262 compute the value, we'll likely end up with SAVE_EXPRs, which
1263 the template substitution machinery does not expect to see. */
1264 || (processing_template_decl
1265 && COMPLETE_TYPE_P (type)
1266 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1268 value = build_min (op, size_type_node, type);
1269 TREE_READONLY (value) = 1;
1273 return c_sizeof_or_alignof_type (complete_type (type),
1278 /* Process a sizeof expression where the operand is an expression. */
1281 cxx_sizeof_expr (tree e)
1283 if (e == error_mark_node)
1284 return error_mark_node;
1286 if (processing_template_decl)
1288 e = build_min (SIZEOF_EXPR, size_type_node, e);
1289 TREE_SIDE_EFFECTS (e) = 0;
1290 TREE_READONLY (e) = 1;
1295 if (TREE_CODE (e) == COMPONENT_REF
1296 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1297 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1299 error ("invalid application of %<sizeof%> to a bit-field");
1302 else if (is_overloaded_fn (e))
1304 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1308 else if (type_unknown_p (e))
1310 cxx_incomplete_type_error (e, TREE_TYPE (e));
1316 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1319 /* Implement the __alignof keyword: Return the minimum required
1320 alignment of E, measured in bytes. For VAR_DECL's and
1321 FIELD_DECL's return DECL_ALIGN (which can be set from an
1322 "aligned" __attribute__ specification). */
1325 cxx_alignof_expr (tree e)
1329 if (e == error_mark_node)
1330 return error_mark_node;
1332 if (processing_template_decl)
1334 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1335 TREE_SIDE_EFFECTS (e) = 0;
1336 TREE_READONLY (e) = 1;
1341 if (TREE_CODE (e) == VAR_DECL)
1342 t = size_int (DECL_ALIGN_UNIT (e));
1343 else if (TREE_CODE (e) == COMPONENT_REF
1344 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1345 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1347 error ("invalid application of %<__alignof%> to a bit-field");
1350 else if (TREE_CODE (e) == COMPONENT_REF
1351 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1352 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1353 else if (is_overloaded_fn (e))
1355 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1357 if (TREE_CODE (e) == FUNCTION_DECL)
1358 t = size_int (DECL_ALIGN_UNIT (e));
1362 else if (type_unknown_p (e))
1364 cxx_incomplete_type_error (e, TREE_TYPE (e));
1368 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1370 return fold_convert (size_type_node, t);
1373 /* Process a sizeof or alignof expression E with code OP where the operand
1374 is an expression. */
1377 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1379 if (op == SIZEOF_EXPR)
1380 return cxx_sizeof_expr (e);
1382 return cxx_alignof_expr (e);
1385 /* EXPR is being used in a context that is not a function call.
1390 The expression can be used only as the left-hand operand of a
1391 member function call.
1393 [expr.mptr.operator]
1395 If the result of .* or ->* is a function, then that result can be
1396 used only as the operand for the function call operator ().
1398 by issuing an error message if appropriate. Returns true iff EXPR
1399 violates these rules. */
1402 invalid_nonstatic_memfn_p (const_tree expr)
1404 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1406 error ("invalid use of non-static member function");
1412 /* If EXP is a reference to a bitfield, and the type of EXP does not
1413 match the declared type of the bitfield, return the declared type
1414 of the bitfield. Otherwise, return NULL_TREE. */
1417 is_bitfield_expr_with_lowered_type (const_tree exp)
1419 switch (TREE_CODE (exp))
1422 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)
1423 ? TREE_OPERAND (exp, 1)
1424 : TREE_OPERAND (exp, 0)))
1426 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1429 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1433 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1439 field = TREE_OPERAND (exp, 1);
1440 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1442 if (same_type_ignoring_top_level_qualifiers_p
1443 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1445 return DECL_BIT_FIELD_TYPE (field);
1453 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1454 bitfield with a lowered type, the type of EXP is returned, rather
1458 unlowered_expr_type (const_tree exp)
1462 type = is_bitfield_expr_with_lowered_type (exp);
1464 type = TREE_TYPE (exp);
1469 /* Perform the conversions in [expr] that apply when an lvalue appears
1470 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1471 function-to-pointer conversions. In addition, manifest constants
1472 are replaced by their values, and bitfield references are converted
1473 to their declared types.
1475 Although the returned value is being used as an rvalue, this
1476 function does not wrap the returned expression in a
1477 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1478 that the return value is no longer an lvalue. */
1481 decay_conversion (tree exp)
1484 enum tree_code code;
1486 type = TREE_TYPE (exp);
1487 if (type == error_mark_node)
1488 return error_mark_node;
1490 if (type_unknown_p (exp))
1492 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1493 return error_mark_node;
1496 exp = decl_constant_value (exp);
1497 if (error_operand_p (exp))
1498 return error_mark_node;
1500 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1501 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1502 code = TREE_CODE (type);
1503 if (code == VOID_TYPE)
1505 error ("void value not ignored as it ought to be");
1506 return error_mark_node;
1508 if (invalid_nonstatic_memfn_p (exp))
1509 return error_mark_node;
1510 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1511 return build_unary_op (ADDR_EXPR, exp, 0);
1512 if (code == ARRAY_TYPE)
1517 if (TREE_CODE (exp) == INDIRECT_REF)
1518 return build_nop (build_pointer_type (TREE_TYPE (type)),
1519 TREE_OPERAND (exp, 0));
1521 if (TREE_CODE (exp) == COMPOUND_EXPR)
1523 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1524 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1525 TREE_OPERAND (exp, 0), op1);
1529 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1531 error ("invalid use of non-lvalue array");
1532 return error_mark_node;
1535 ptrtype = build_pointer_type (TREE_TYPE (type));
1537 if (TREE_CODE (exp) == VAR_DECL)
1539 if (!cxx_mark_addressable (exp))
1540 return error_mark_node;
1541 adr = build_nop (ptrtype, build_address (exp));
1544 /* This way is better for a COMPONENT_REF since it can
1545 simplify the offset for a component. */
1546 adr = build_unary_op (ADDR_EXPR, exp, 1);
1547 return cp_convert (ptrtype, adr);
1550 /* If a bitfield is used in a context where integral promotion
1551 applies, then the caller is expected to have used
1552 default_conversion. That function promotes bitfields correctly
1553 before calling this function. At this point, if we have a
1554 bitfield referenced, we may assume that is not subject to
1555 promotion, and that, therefore, the type of the resulting rvalue
1556 is the declared type of the bitfield. */
1557 exp = convert_bitfield_to_declared_type (exp);
1559 /* We do not call rvalue() here because we do not want to wrap EXP
1560 in a NON_LVALUE_EXPR. */
1564 Non-class rvalues always have cv-unqualified types. */
1565 type = TREE_TYPE (exp);
1566 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1567 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1572 /* Perform prepatory conversions, as part of the "usual arithmetic
1573 conversions". In particular, as per [expr]:
1575 Whenever an lvalue expression appears as an operand of an
1576 operator that expects the rvalue for that operand, the
1577 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1578 standard conversions are applied to convert the expression to an
1581 In addition, we perform integral promotions here, as those are
1582 applied to both operands to a binary operator before determining
1583 what additional conversions should apply. */
1586 default_conversion (tree exp)
1588 /* Perform the integral promotions first so that bitfield
1589 expressions (which may promote to "int", even if the bitfield is
1590 declared "unsigned") are promoted correctly. */
1591 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1592 exp = perform_integral_promotions (exp);
1593 /* Perform the other conversions. */
1594 exp = decay_conversion (exp);
1599 /* EXPR is an expression with an integral or enumeration type.
1600 Perform the integral promotions in [conv.prom], and return the
1604 perform_integral_promotions (tree expr)
1611 If the bitfield has an enumerated type, it is treated as any
1612 other value of that type for promotion purposes. */
1613 type = is_bitfield_expr_with_lowered_type (expr);
1614 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1615 type = TREE_TYPE (expr);
1616 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1617 promoted_type = type_promotes_to (type);
1618 if (type != promoted_type)
1619 expr = cp_convert (promoted_type, expr);
1623 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1627 inline_conversion (tree exp)
1629 if (TREE_CODE (exp) == FUNCTION_DECL)
1630 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1635 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1636 decay_conversion to one. */
1639 string_conv_p (const_tree totype, const_tree exp, int warn)
1643 if (TREE_CODE (totype) != POINTER_TYPE)
1646 t = TREE_TYPE (totype);
1647 if (!same_type_p (t, char_type_node)
1648 && !same_type_p (t, wchar_type_node))
1651 if (TREE_CODE (exp) == STRING_CST)
1653 /* Make sure that we don't try to convert between char and wchar_t. */
1654 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1659 /* Is this a string constant which has decayed to 'const char *'? */
1660 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1661 if (!same_type_p (TREE_TYPE (exp), t))
1664 if (TREE_CODE (exp) != ADDR_EXPR
1665 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1669 /* This warning is not very useful, as it complains about printf. */
1671 warning (OPT_Wwrite_strings,
1672 "deprecated conversion from string constant to %qT",
1678 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1679 can, for example, use as an lvalue. This code used to be in
1680 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1681 expressions, where we're dealing with aggregates. But now it's again only
1682 called from unary_complex_lvalue. The case (in particular) that led to
1683 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1687 rationalize_conditional_expr (enum tree_code code, tree t)
1689 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1690 the first operand is always the one to be used if both operands
1691 are equal, so we know what conditional expression this used to be. */
1692 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1694 tree op0 = TREE_OPERAND (t, 0);
1695 tree op1 = TREE_OPERAND (t, 1);
1697 /* The following code is incorrect if either operand side-effects. */
1698 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1699 && !TREE_SIDE_EFFECTS (op1));
1701 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1702 ? LE_EXPR : GE_EXPR),
1703 op0, TREE_CODE (op0),
1704 op1, TREE_CODE (op1),
1705 /*overloaded_p=*/NULL),
1706 build_unary_op (code, op0, 0),
1707 build_unary_op (code, op1, 0));
1711 build_conditional_expr (TREE_OPERAND (t, 0),
1712 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1713 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1716 /* Given the TYPE of an anonymous union field inside T, return the
1717 FIELD_DECL for the field. If not found return NULL_TREE. Because
1718 anonymous unions can nest, we must also search all anonymous unions
1719 that are directly reachable. */
1722 lookup_anon_field (tree t, tree type)
1726 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1728 if (TREE_STATIC (field))
1730 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1733 /* If we find it directly, return the field. */
1734 if (DECL_NAME (field) == NULL_TREE
1735 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1740 /* Otherwise, it could be nested, search harder. */
1741 if (DECL_NAME (field) == NULL_TREE
1742 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1744 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1752 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1753 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1754 non-NULL, it indicates the path to the base used to name MEMBER.
1755 If PRESERVE_REFERENCE is true, the expression returned will have
1756 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1757 returned will have the type referred to by the reference.
1759 This function does not perform access control; that is either done
1760 earlier by the parser when the name of MEMBER is resolved to MEMBER
1761 itself, or later when overload resolution selects one of the
1762 functions indicated by MEMBER. */
1765 build_class_member_access_expr (tree object, tree member,
1766 tree access_path, bool preserve_reference)
1770 tree result = NULL_TREE;
1772 if (error_operand_p (object) || error_operand_p (member))
1773 return error_mark_node;
1775 gcc_assert (DECL_P (member) || BASELINK_P (member));
1779 The type of the first expression shall be "class object" (of a
1781 object_type = TREE_TYPE (object);
1782 if (!currently_open_class (object_type)
1783 && !complete_type_or_else (object_type, object))
1784 return error_mark_node;
1785 if (!CLASS_TYPE_P (object_type))
1787 error ("request for member %qD in %qE, which is of non-class type %qT",
1788 member, object, object_type);
1789 return error_mark_node;
1792 /* The standard does not seem to actually say that MEMBER must be a
1793 member of OBJECT_TYPE. However, that is clearly what is
1795 if (DECL_P (member))
1797 member_scope = DECL_CLASS_CONTEXT (member);
1799 if (TREE_DEPRECATED (member))
1800 warn_deprecated_use (member);
1803 member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member));
1804 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1805 presently be the anonymous union. Go outwards until we find a
1806 type related to OBJECT_TYPE. */
1807 while (ANON_AGGR_TYPE_P (member_scope)
1808 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1810 member_scope = TYPE_CONTEXT (member_scope);
1811 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1813 if (TREE_CODE (member) == FIELD_DECL)
1814 error ("invalid use of nonstatic data member %qE", member);
1816 error ("%qD is not a member of %qT", member, object_type);
1817 return error_mark_node;
1820 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1821 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1822 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1824 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1826 object = build_indirect_ref (temp, NULL);
1829 /* In [expr.ref], there is an explicit list of the valid choices for
1830 MEMBER. We check for each of those cases here. */
1831 if (TREE_CODE (member) == VAR_DECL)
1833 /* A static data member. */
1835 /* If OBJECT has side-effects, they are supposed to occur. */
1836 if (TREE_SIDE_EFFECTS (object))
1837 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1839 else if (TREE_CODE (member) == FIELD_DECL)
1841 /* A non-static data member. */
1846 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1847 && integer_zerop (TREE_OPERAND (object, 0)));
1849 /* Convert OBJECT to the type of MEMBER. */
1850 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1851 TYPE_MAIN_VARIANT (member_scope)))
1856 binfo = lookup_base (access_path ? access_path : object_type,
1857 member_scope, ba_unique, &kind);
1858 if (binfo == error_mark_node)
1859 return error_mark_node;
1861 /* It is invalid to try to get to a virtual base of a
1862 NULL object. The most common cause is invalid use of
1864 if (null_object_p && kind == bk_via_virtual)
1866 error ("invalid access to non-static data member %qD of "
1869 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1870 return error_mark_node;
1873 /* Convert to the base. */
1874 object = build_base_path (PLUS_EXPR, object, binfo,
1876 /* If we found the base successfully then we should be able
1877 to convert to it successfully. */
1878 gcc_assert (object != error_mark_node);
1881 /* Complain about other invalid uses of offsetof, even though they will
1882 give the right answer. Note that we complain whether or not they
1883 actually used the offsetof macro, since there's no way to know at this
1884 point. So we just give a warning, instead of a pedwarn. */
1885 /* Do not produce this warning for base class field references, because
1886 we know for a fact that didn't come from offsetof. This does occur
1887 in various testsuite cases where a null object is passed where a
1888 vtable access is required. */
1889 if (null_object_p && warn_invalid_offsetof
1890 && CLASSTYPE_NON_POD_P (object_type)
1891 && !DECL_FIELD_IS_BASE (member)
1892 && !skip_evaluation)
1894 warning (0, "invalid access to non-static data member %qD of NULL object",
1896 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1899 /* If MEMBER is from an anonymous aggregate, we have converted
1900 OBJECT so that it refers to the class containing the
1901 anonymous union. Generate a reference to the anonymous union
1902 itself, and recur to find MEMBER. */
1903 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1904 /* When this code is called from build_field_call, the
1905 object already has the type of the anonymous union.
1906 That is because the COMPONENT_REF was already
1907 constructed, and was then disassembled before calling
1908 build_field_call. After the function-call code is
1909 cleaned up, this waste can be eliminated. */
1910 && (!same_type_ignoring_top_level_qualifiers_p
1911 (TREE_TYPE (object), DECL_CONTEXT (member))))
1913 tree anonymous_union;
1915 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1916 DECL_CONTEXT (member));
1917 object = build_class_member_access_expr (object,
1919 /*access_path=*/NULL_TREE,
1920 preserve_reference);
1923 /* Compute the type of the field, as described in [expr.ref]. */
1924 type_quals = TYPE_UNQUALIFIED;
1925 member_type = TREE_TYPE (member);
1926 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1928 type_quals = (cp_type_quals (member_type)
1929 | cp_type_quals (object_type));
1931 /* A field is const (volatile) if the enclosing object, or the
1932 field itself, is const (volatile). But, a mutable field is
1933 not const, even within a const object. */
1934 if (DECL_MUTABLE_P (member))
1935 type_quals &= ~TYPE_QUAL_CONST;
1936 member_type = cp_build_qualified_type (member_type, type_quals);
1939 result = build3 (COMPONENT_REF, member_type, object, member,
1941 result = fold_if_not_in_template (result);
1943 /* Mark the expression const or volatile, as appropriate. Even
1944 though we've dealt with the type above, we still have to mark the
1945 expression itself. */
1946 if (type_quals & TYPE_QUAL_CONST)
1947 TREE_READONLY (result) = 1;
1948 if (type_quals & TYPE_QUAL_VOLATILE)
1949 TREE_THIS_VOLATILE (result) = 1;
1951 else if (BASELINK_P (member))
1953 /* The member is a (possibly overloaded) member function. */
1957 /* If the MEMBER is exactly one static member function, then we
1958 know the type of the expression. Otherwise, we must wait
1959 until overload resolution has been performed. */
1960 functions = BASELINK_FUNCTIONS (member);
1961 if (TREE_CODE (functions) == FUNCTION_DECL
1962 && DECL_STATIC_FUNCTION_P (functions))
1963 type = TREE_TYPE (functions);
1965 type = unknown_type_node;
1966 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1967 base. That will happen when the function is called. */
1968 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1970 else if (TREE_CODE (member) == CONST_DECL)
1972 /* The member is an enumerator. */
1974 /* If OBJECT has side-effects, they are supposed to occur. */
1975 if (TREE_SIDE_EFFECTS (object))
1976 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1981 error ("invalid use of %qD", member);
1982 return error_mark_node;
1985 if (!preserve_reference)
1988 If E2 is declared to have type "reference to T", then ... the
1989 type of E1.E2 is T. */
1990 result = convert_from_reference (result);
1995 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1996 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1999 lookup_destructor (tree object, tree scope, tree dtor_name)
2001 tree object_type = TREE_TYPE (object);
2002 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2005 if (scope && !check_dtor_name (scope, dtor_type))
2007 error ("qualified type %qT does not match destructor name ~%qT",
2009 return error_mark_node;
2011 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2013 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2014 TYPE_MAIN_VARIANT (object_type), dtor_type);
2015 return error_mark_node;
2017 expr = lookup_member (dtor_type, complete_dtor_identifier,
2018 /*protect=*/1, /*want_type=*/false);
2019 expr = (adjust_result_of_qualified_name_lookup
2020 (expr, dtor_type, object_type));
2024 /* An expression of the form "A::template B" has been resolved to
2025 DECL. Issue a diagnostic if B is not a template or template
2029 check_template_keyword (tree decl)
2031 /* The standard says:
2035 If a name prefixed by the keyword template is not a member
2036 template, the program is ill-formed.
2038 DR 228 removed the restriction that the template be a member
2041 DR 96, if accepted would add the further restriction that explicit
2042 template arguments must be provided if the template keyword is
2043 used, but, as of 2005-10-16, that DR is still in "drafting". If
2044 this DR is accepted, then the semantic checks here can be
2045 simplified, as the entity named must in fact be a template
2046 specialization, rather than, as at present, a set of overloaded
2047 functions containing at least one template function. */
2048 if (TREE_CODE (decl) != TEMPLATE_DECL
2049 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2051 if (!is_overloaded_fn (decl))
2052 pedwarn ("%qD is not a template", decl);
2057 if (BASELINK_P (fns))
2058 fns = BASELINK_FUNCTIONS (fns);
2061 tree fn = OVL_CURRENT (fns);
2062 if (TREE_CODE (fn) == TEMPLATE_DECL
2063 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2065 if (TREE_CODE (fn) == FUNCTION_DECL
2066 && DECL_USE_TEMPLATE (fn)
2067 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2069 fns = OVL_NEXT (fns);
2072 pedwarn ("%qD is not a template", decl);
2077 /* This function is called by the parser to process a class member
2078 access expression of the form OBJECT.NAME. NAME is a node used by
2079 the parser to represent a name; it is not yet a DECL. It may,
2080 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2081 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2082 there is no reason to do the lookup twice, so the parser keeps the
2083 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2084 be a template via the use of the "A::template B" syntax. */
2087 finish_class_member_access_expr (tree object, tree name, bool template_p)
2092 tree access_path = NULL_TREE;
2093 tree orig_object = object;
2094 tree orig_name = name;
2096 if (object == error_mark_node || name == error_mark_node)
2097 return error_mark_node;
2099 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2100 if (!objc_is_public (object, name))
2101 return error_mark_node;
2103 object_type = TREE_TYPE (object);
2105 if (processing_template_decl)
2107 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2108 dependent_type_p (object_type)
2109 /* If NAME is just an IDENTIFIER_NODE, then the expression
2111 || TREE_CODE (object) == IDENTIFIER_NODE
2112 /* If NAME is "f<args>", where either 'f' or 'args' is
2113 dependent, then the expression is dependent. */
2114 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2115 && dependent_template_id_p (TREE_OPERAND (name, 0),
2116 TREE_OPERAND (name, 1)))
2117 /* If NAME is "T::X" where "T" is dependent, then the
2118 expression is dependent. */
2119 || (TREE_CODE (name) == SCOPE_REF
2120 && TYPE_P (TREE_OPERAND (name, 0))
2121 && dependent_type_p (TREE_OPERAND (name, 0))))
2122 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2123 object = build_non_dependent_expr (object);
2128 The type of the first expression shall be "class object" (of a
2130 if (!currently_open_class (object_type)
2131 && !complete_type_or_else (object_type, object))
2132 return error_mark_node;
2133 if (!CLASS_TYPE_P (object_type))
2135 error ("request for member %qD in %qE, which is of non-class type %qT",
2136 name, object, object_type);
2137 return error_mark_node;
2140 if (BASELINK_P (name))
2141 /* A member function that has already been looked up. */
2145 bool is_template_id = false;
2146 tree template_args = NULL_TREE;
2149 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2151 is_template_id = true;
2152 template_args = TREE_OPERAND (name, 1);
2153 name = TREE_OPERAND (name, 0);
2155 if (TREE_CODE (name) == OVERLOAD)
2156 name = DECL_NAME (get_first_fn (name));
2157 else if (DECL_P (name))
2158 name = DECL_NAME (name);
2161 if (TREE_CODE (name) == SCOPE_REF)
2163 /* A qualified name. The qualifying class or namespace `S'
2164 has already been looked up; it is either a TYPE or a
2166 scope = TREE_OPERAND (name, 0);
2167 name = TREE_OPERAND (name, 1);
2169 /* If SCOPE is a namespace, then the qualified name does not
2170 name a member of OBJECT_TYPE. */
2171 if (TREE_CODE (scope) == NAMESPACE_DECL)
2173 error ("%<%D::%D%> is not a member of %qT",
2174 scope, name, object_type);
2175 return error_mark_node;
2178 gcc_assert (CLASS_TYPE_P (scope));
2179 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2180 || TREE_CODE (name) == BIT_NOT_EXPR);
2182 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2183 access_path = lookup_base (object_type, scope, ba_check, NULL);
2184 if (access_path == error_mark_node)
2185 return error_mark_node;
2188 error ("%qT is not a base of %qT", scope, object_type);
2189 return error_mark_node;
2195 access_path = object_type;
2198 if (TREE_CODE (name) == BIT_NOT_EXPR)
2199 member = lookup_destructor (object, scope, name);
2202 /* Look up the member. */
2203 member = lookup_member (access_path, name, /*protect=*/1,
2204 /*want_type=*/false);
2205 if (member == NULL_TREE)
2207 error ("%qD has no member named %qE", object_type, name);
2208 return error_mark_node;
2210 if (member == error_mark_node)
2211 return error_mark_node;
2216 tree template = member;
2218 if (BASELINK_P (template))
2219 template = lookup_template_function (template, template_args);
2222 error ("%qD is not a member template function", name);
2223 return error_mark_node;
2228 if (TREE_DEPRECATED (member))
2229 warn_deprecated_use (member);
2232 check_template_keyword (member);
2234 expr = build_class_member_access_expr (object, member, access_path,
2235 /*preserve_reference=*/false);
2236 if (processing_template_decl && expr != error_mark_node)
2238 if (BASELINK_P (member))
2240 if (TREE_CODE (orig_name) == SCOPE_REF)
2241 BASELINK_QUALIFIED_P (member) = 1;
2244 return build_min_non_dep (COMPONENT_REF, expr,
2245 orig_object, orig_name,
2252 /* Return an expression for the MEMBER_NAME field in the internal
2253 representation of PTRMEM, a pointer-to-member function. (Each
2254 pointer-to-member function type gets its own RECORD_TYPE so it is
2255 more convenient to access the fields by name than by FIELD_DECL.)
2256 This routine converts the NAME to a FIELD_DECL and then creates the
2257 node for the complete expression. */
2260 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2266 /* This code is a stripped down version of
2267 build_class_member_access_expr. It does not work to use that
2268 routine directly because it expects the object to be of class
2270 ptrmem_type = TREE_TYPE (ptrmem);
2271 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2272 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2273 /*want_type=*/false);
2274 member_type = cp_build_qualified_type (TREE_TYPE (member),
2275 cp_type_quals (ptrmem_type));
2276 return fold_build3 (COMPONENT_REF, member_type,
2277 ptrmem, member, NULL_TREE);
2280 /* Given an expression PTR for a pointer, return an expression
2281 for the value pointed to.
2282 ERRORSTRING is the name of the operator to appear in error messages.
2284 This function may need to overload OPERATOR_FNNAME.
2285 Must also handle REFERENCE_TYPEs for C++. */
2288 build_x_indirect_ref (tree expr, const char *errorstring)
2290 tree orig_expr = expr;
2293 if (processing_template_decl)
2295 if (type_dependent_expression_p (expr))
2296 return build_min_nt (INDIRECT_REF, expr);
2297 expr = build_non_dependent_expr (expr);
2300 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2301 NULL_TREE, /*overloaded_p=*/NULL);
2303 rval = build_indirect_ref (expr, errorstring);
2305 if (processing_template_decl && rval != error_mark_node)
2306 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2312 build_indirect_ref (tree ptr, const char *errorstring)
2316 if (ptr == error_mark_node)
2317 return error_mark_node;
2319 if (ptr == current_class_ptr)
2320 return current_class_ref;
2322 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2323 ? ptr : decay_conversion (ptr));
2324 type = TREE_TYPE (pointer);
2326 if (POINTER_TYPE_P (type))
2330 If the type of the expression is "pointer to T," the type
2331 of the result is "T."
2333 We must use the canonical variant because certain parts of
2334 the back end, like fold, do pointer comparisons between
2336 tree t = canonical_type_variant (TREE_TYPE (type));
2338 if (TREE_CODE (ptr) == CONVERT_EXPR
2339 || TREE_CODE (ptr) == NOP_EXPR
2340 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2342 /* If a warning is issued, mark it to avoid duplicates from
2343 the backend. This only needs to be done at
2344 warn_strict_aliasing > 2. */
2345 if (warn_strict_aliasing > 2)
2346 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2347 type, TREE_OPERAND (ptr, 0)))
2348 TREE_NO_WARNING (ptr) = 1;
2351 if (VOID_TYPE_P (t))
2353 /* A pointer to incomplete type (other than cv void) can be
2354 dereferenced [expr.unary.op]/1 */
2355 error ("%qT is not a pointer-to-object type", type);
2356 return error_mark_node;
2358 else if (TREE_CODE (pointer) == ADDR_EXPR
2359 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2360 /* The POINTER was something like `&x'. We simplify `*&x' to
2362 return TREE_OPERAND (pointer, 0);
2365 tree ref = build1 (INDIRECT_REF, t, pointer);
2367 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2368 so that we get the proper error message if the result is used
2369 to assign to. Also, &* is supposed to be a no-op. */
2370 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2371 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2372 TREE_SIDE_EFFECTS (ref)
2373 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2377 /* `pointer' won't be an error_mark_node if we were given a
2378 pointer to member, so it's cool to check for this here. */
2379 else if (TYPE_PTR_TO_MEMBER_P (type))
2380 error ("invalid use of %qs on pointer to member", errorstring);
2381 else if (pointer != error_mark_node)
2384 error ("invalid type argument of %qs", errorstring);
2386 error ("invalid type argument");
2388 return error_mark_node;
2391 /* This handles expressions of the form "a[i]", which denotes
2394 This is logically equivalent in C to *(a+i), but we may do it differently.
2395 If A is a variable or a member, we generate a primitive ARRAY_REF.
2396 This avoids forcing the array out of registers, and can work on
2397 arrays that are not lvalues (for example, members of structures returned
2400 If INDEX is of some user-defined type, it must be converted to
2401 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2402 will inherit the type of the array, which will be some pointer type. */
2405 build_array_ref (tree array, tree idx)
2409 error ("subscript missing in array reference");
2410 return error_mark_node;
2413 if (TREE_TYPE (array) == error_mark_node
2414 || TREE_TYPE (idx) == error_mark_node)
2415 return error_mark_node;
2417 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2419 switch (TREE_CODE (array))
2423 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2424 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2425 TREE_OPERAND (array, 0), value);
2429 return build_conditional_expr
2430 (TREE_OPERAND (array, 0),
2431 build_array_ref (TREE_OPERAND (array, 1), idx),
2432 build_array_ref (TREE_OPERAND (array, 2), idx));
2438 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2442 warn_array_subscript_with_type_char (idx);
2444 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2446 error ("array subscript is not an integer");
2447 return error_mark_node;
2450 /* Apply integral promotions *after* noticing character types.
2451 (It is unclear why we do these promotions -- the standard
2452 does not say that we should. In fact, the natural thing would
2453 seem to be to convert IDX to ptrdiff_t; we're performing
2454 pointer arithmetic.) */
2455 idx = perform_integral_promotions (idx);
2457 /* An array that is indexed by a non-constant
2458 cannot be stored in a register; we must be able to do
2459 address arithmetic on its address.
2460 Likewise an array of elements of variable size. */
2461 if (TREE_CODE (idx) != INTEGER_CST
2462 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2463 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2466 if (!cxx_mark_addressable (array))
2467 return error_mark_node;
2470 /* An array that is indexed by a constant value which is not within
2471 the array bounds cannot be stored in a register either; because we
2472 would get a crash in store_bit_field/extract_bit_field when trying
2473 to access a non-existent part of the register. */
2474 if (TREE_CODE (idx) == INTEGER_CST
2475 && TYPE_DOMAIN (TREE_TYPE (array))
2476 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2478 if (!cxx_mark_addressable (array))
2479 return error_mark_node;
2482 if (pedantic && !lvalue_p (array))
2483 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2485 /* Note in C++ it is valid to subscript a `register' array, since
2486 it is valid to take the address of something with that
2487 storage specification. */
2491 while (TREE_CODE (foo) == COMPONENT_REF)
2492 foo = TREE_OPERAND (foo, 0);
2493 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2494 warning (OPT_Wextra, "subscripting array declared %<register%>");
2497 type = TREE_TYPE (TREE_TYPE (array));
2498 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2499 /* Array ref is const/volatile if the array elements are
2500 or if the array is.. */
2501 TREE_READONLY (rval)
2502 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2503 TREE_SIDE_EFFECTS (rval)
2504 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2505 TREE_THIS_VOLATILE (rval)
2506 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2507 return require_complete_type (fold_if_not_in_template (rval));
2511 tree ar = default_conversion (array);
2512 tree ind = default_conversion (idx);
2514 /* Put the integer in IND to simplify error checking. */
2515 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2522 if (ar == error_mark_node)
2525 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2527 error ("subscripted value is neither array nor pointer");
2528 return error_mark_node;
2530 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2532 error ("array subscript is not an integer");
2533 return error_mark_node;
2536 warn_array_subscript_with_type_char (idx);
2538 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2543 /* Resolve a pointer to member function. INSTANCE is the object
2544 instance to use, if the member points to a virtual member.
2546 This used to avoid checking for virtual functions if basetype
2547 has no virtual functions, according to an earlier ANSI draft.
2548 With the final ISO C++ rules, such an optimization is
2549 incorrect: A pointer to a derived member can be static_cast
2550 to pointer-to-base-member, as long as the dynamic object
2551 later has the right member. */
2554 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2556 if (TREE_CODE (function) == OFFSET_REF)
2557 function = TREE_OPERAND (function, 1);
2559 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2561 tree idx, delta, e1, e2, e3, vtbl, basetype;
2562 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2564 tree instance_ptr = *instance_ptrptr;
2565 tree instance_save_expr = 0;
2566 if (instance_ptr == error_mark_node)
2568 if (TREE_CODE (function) == PTRMEM_CST)
2570 /* Extracting the function address from a pmf is only
2571 allowed with -Wno-pmf-conversions. It only works for
2573 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2574 e1 = convert (fntype, e1);
2579 error ("object missing in use of %qE", function);
2580 return error_mark_node;
2584 if (TREE_SIDE_EFFECTS (instance_ptr))
2585 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2587 if (TREE_SIDE_EFFECTS (function))
2588 function = save_expr (function);
2590 /* Start by extracting all the information from the PMF itself. */
2591 e3 = pfn_from_ptrmemfunc (function);
2592 delta = delta_from_ptrmemfunc (function);
2593 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2594 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2596 case ptrmemfunc_vbit_in_pfn:
2597 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2598 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2601 case ptrmemfunc_vbit_in_delta:
2602 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2603 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2610 /* Convert down to the right base before using the instance. A
2611 special case is that in a pointer to member of class C, C may
2612 be incomplete. In that case, the function will of course be
2613 a member of C, and no conversion is required. In fact,
2614 lookup_base will fail in that case, because incomplete
2615 classes do not have BINFOs. */
2616 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2617 if (!same_type_ignoring_top_level_qualifiers_p
2618 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2620 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2621 basetype, ba_check, NULL);
2622 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2624 if (instance_ptr == error_mark_node)
2625 return error_mark_node;
2627 /* ...and then the delta in the PMF. */
2628 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
2629 instance_ptr, fold_convert (sizetype, delta));
2631 /* Hand back the adjusted 'this' argument to our caller. */
2632 *instance_ptrptr = instance_ptr;
2634 /* Next extract the vtable pointer from the object. */
2635 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2637 vtbl = build_indirect_ref (vtbl, NULL);
2639 /* Finally, extract the function pointer from the vtable. */
2640 e2 = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
2641 fold_convert (sizetype, idx));
2642 e2 = build_indirect_ref (e2, NULL);
2643 TREE_CONSTANT (e2) = 1;
2644 TREE_INVARIANT (e2) = 1;
2646 /* When using function descriptors, the address of the
2647 vtable entry is treated as a function pointer. */
2648 if (TARGET_VTABLE_USES_DESCRIPTORS)
2649 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2650 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2652 e2 = fold_convert (TREE_TYPE (e3), e2);
2653 e1 = build_conditional_expr (e1, e2, e3);
2655 /* Make sure this doesn't get evaluated first inside one of the
2656 branches of the COND_EXPR. */
2657 if (instance_save_expr)
2658 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2659 instance_save_expr, e1);
2667 build_function_call (tree function, tree params)
2669 tree fntype, fndecl;
2670 tree name = NULL_TREE;
2672 tree original = function;
2673 int nargs, parm_types_len;
2677 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2678 expressions, like those used for ObjC messenger dispatches. */
2679 function = objc_rewrite_function_call (function, params);
2681 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2682 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2683 if (TREE_CODE (function) == NOP_EXPR
2684 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2685 function = TREE_OPERAND (function, 0);
2687 if (TREE_CODE (function) == FUNCTION_DECL)
2689 name = DECL_NAME (function);
2691 mark_used (function);
2694 /* Convert anything with function type to a pointer-to-function. */
2695 if (pedantic && DECL_MAIN_P (function))
2696 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2698 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2699 (because calling an inline function does not mean the function
2700 needs to be separately compiled). */
2702 if (DECL_INLINE (function))
2703 function = inline_conversion (function);
2705 function = build_addr_func (function);
2711 function = build_addr_func (function);
2714 if (function == error_mark_node)
2715 return error_mark_node;
2717 fntype = TREE_TYPE (function);
2719 if (TYPE_PTRMEMFUNC_P (fntype))
2721 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2722 "function in %<%E (...)%>",
2724 return error_mark_node;
2727 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2728 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2730 if (!((TREE_CODE (fntype) == POINTER_TYPE
2731 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2733 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2735 error ("%qE cannot be used as a function", original);
2736 return error_mark_node;
2739 /* fntype now gets the type of function pointed to. */
2740 fntype = TREE_TYPE (fntype);
2741 parm_types = TYPE_ARG_TYPES (fntype);
2743 /* Allocate storage for converted arguments. */
2744 parm_types_len = list_length (parm_types);
2745 nargs = list_length (params);
2746 if (parm_types_len > nargs)
2747 nargs = parm_types_len;
2748 argarray = (tree *) alloca (nargs * sizeof (tree));
2750 /* Convert the parameters to the types declared in the
2751 function prototype, or apply default promotions. */
2752 nargs = convert_arguments (nargs, argarray, parm_types,
2753 params, fndecl, LOOKUP_NORMAL);
2755 return error_mark_node;
2757 /* Check for errors in format strings and inappropriately
2760 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2763 return build_cxx_call (function, nargs, argarray);
2766 /* Convert the actual parameter expressions in the list VALUES
2767 to the types in the list TYPELIST.
2768 If parmdecls is exhausted, or when an element has NULL as its type,
2769 perform the default conversions.
2771 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2773 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2775 This is also where warnings about wrong number of args are generated.
2777 Returns the actual number of arguments processed (which might be less
2778 than NARGS), or -1 on error.
2780 VALUES is a chain of TREE_LIST nodes with the elements of the list
2781 in the TREE_VALUE slots of those nodes.
2783 In C++, unspecified trailing parameters can be filled in with their
2784 default arguments, if such were specified. Do so here. */
2787 convert_arguments (int nargs, tree *argarray,
2788 tree typelist, tree values, tree fndecl, int flags)
2790 tree typetail, valtail;
2791 const char *called_thing = 0;
2794 /* Argument passing is always copy-initialization. */
2795 flags |= LOOKUP_ONLYCONVERTING;
2799 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2801 if (DECL_NAME (fndecl) == NULL_TREE
2802 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2803 called_thing = "constructor";
2805 called_thing = "member function";
2808 called_thing = "function";
2811 for (valtail = values, typetail = typelist;
2813 valtail = TREE_CHAIN (valtail), i++)
2815 tree type = typetail ? TREE_VALUE (typetail) : 0;
2816 tree val = TREE_VALUE (valtail);
2818 if (val == error_mark_node || type == error_mark_node)
2821 if (type == void_type_node)
2825 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2826 error ("at this point in file");
2829 error ("too many arguments to function");
2833 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2834 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2835 if (TREE_CODE (val) == NOP_EXPR
2836 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2837 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2838 val = TREE_OPERAND (val, 0);
2840 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2842 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2843 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2844 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2845 val = decay_conversion (val);
2848 if (val == error_mark_node)
2853 /* Formal parm type is specified by a function prototype. */
2856 if (!COMPLETE_TYPE_P (complete_type (type)))
2859 error ("parameter %P of %qD has incomplete type %qT",
2862 error ("parameter %P has incomplete type %qT", i, type);
2863 parmval = error_mark_node;
2867 parmval = convert_for_initialization
2868 (NULL_TREE, type, val, flags,
2869 "argument passing", fndecl, i);
2870 parmval = convert_for_arg_passing (type, parmval);
2873 if (parmval == error_mark_node)
2876 argarray[i] = parmval;
2880 if (fndecl && DECL_BUILT_IN (fndecl)
2881 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2882 /* Don't do ellipsis conversion for __built_in_constant_p
2883 as this will result in spurious warnings for non-POD
2885 val = require_complete_type (val);
2887 val = convert_arg_to_ellipsis (val);
2893 typetail = TREE_CHAIN (typetail);
2896 if (typetail != 0 && typetail != void_list_node)
2898 /* See if there are default arguments that can be used. Because
2899 we hold default arguments in the FUNCTION_TYPE (which is so
2900 wrong), we can see default parameters here from deduced
2901 contexts (and via typeof) for indirect function calls.
2902 Fortunately we know whether we have a function decl to
2903 provide default arguments in a language conformant
2905 if (fndecl && TREE_PURPOSE (typetail)
2906 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2908 for (; typetail != void_list_node; ++i)
2911 = convert_default_arg (TREE_VALUE (typetail),
2912 TREE_PURPOSE (typetail),
2915 if (parmval == error_mark_node)
2918 argarray[i] = parmval;
2919 typetail = TREE_CHAIN (typetail);
2920 /* ends with `...'. */
2921 if (typetail == NULL_TREE)
2929 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2930 error ("at this point in file");
2933 error ("too few arguments to function");
2938 gcc_assert (i <= nargs);
2942 /* Build a binary-operation expression, after performing default
2943 conversions on the operands. CODE is the kind of expression to
2944 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2945 are the tree codes which correspond to ARG1 and ARG2 when issuing
2946 warnings about possibly misplaced parentheses. They may differ
2947 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2948 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2949 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2950 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2951 ARG2_CODE as ERROR_MARK. */
2954 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2955 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2964 if (processing_template_decl)
2966 if (type_dependent_expression_p (arg1)
2967 || type_dependent_expression_p (arg2))
2968 return build_min_nt (code, arg1, arg2);
2969 arg1 = build_non_dependent_expr (arg1);
2970 arg2 = build_non_dependent_expr (arg2);
2973 if (code == DOTSTAR_EXPR)
2974 expr = build_m_component_ref (arg1, arg2);
2976 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2979 /* Check for cases such as x+y<<z which users are likely to
2980 misinterpret. But don't warn about obj << x + y, since that is a
2981 common idiom for I/O. */
2982 if (warn_parentheses
2983 && !processing_template_decl
2984 && !error_operand_p (arg1)
2985 && !error_operand_p (arg2)
2986 && (code != LSHIFT_EXPR
2987 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2988 warn_about_parentheses (code, arg1_code, arg2_code);
2990 if (processing_template_decl && expr != error_mark_node)
2991 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2996 /* Build a binary-operation expression without default conversions.
2997 CODE is the kind of expression to build.
2998 This function differs from `build' in several ways:
2999 the data type of the result is computed and recorded in it,
3000 warnings are generated if arg data types are invalid,
3001 special handling for addition and subtraction of pointers is known,
3002 and some optimization is done (operations on narrow ints
3003 are done in the narrower type when that gives the same result).
3004 Constant folding is also done before the result is returned.
3006 Note that the operands will never have enumeral types
3007 because either they have just had the default conversions performed
3008 or they have both just been converted to some other type in which
3009 the arithmetic is to be done.
3011 C++: must do special pointer arithmetic when implementing
3012 multiple inheritance, and deal with pointer to member functions. */
3015 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3016 int convert_p ATTRIBUTE_UNUSED)
3019 enum tree_code code0, code1;
3021 const char *invalid_op_diag;
3023 /* Expression code to give to the expression when it is built.
3024 Normally this is CODE, which is what the caller asked for,
3025 but in some special cases we change it. */
3026 enum tree_code resultcode = code;
3028 /* Data type in which the computation is to be performed.
3029 In the simplest cases this is the common type of the arguments. */
3030 tree result_type = NULL;
3032 /* Nonzero means operands have already been type-converted
3033 in whatever way is necessary.
3034 Zero means they need to be converted to RESULT_TYPE. */
3037 /* Nonzero means create the expression with this type, rather than
3039 tree build_type = 0;
3041 /* Nonzero means after finally constructing the expression
3042 convert it to this type. */
3043 tree final_type = 0;
3047 /* Nonzero if this is an operation like MIN or MAX which can
3048 safely be computed in short if both args are promoted shorts.
3049 Also implies COMMON.
3050 -1 indicates a bitwise operation; this makes a difference
3051 in the exact conditions for when it is safe to do the operation
3052 in a narrower mode. */
3055 /* Nonzero if this is a comparison operation;
3056 if both args are promoted shorts, compare the original shorts.
3057 Also implies COMMON. */
3058 int short_compare = 0;
3060 /* Nonzero if this is a right-shift operation, which can be computed on the
3061 original short and then promoted if the operand is a promoted short. */
3062 int short_shift = 0;
3064 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3067 /* True if both operands have arithmetic type. */
3068 bool arithmetic_types_p;
3070 /* Apply default conversions. */
3074 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3075 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3076 || code == TRUTH_XOR_EXPR)
3078 if (!really_overloaded_fn (op0))
3079 op0 = decay_conversion (op0);
3080 if (!really_overloaded_fn (op1))
3081 op1 = decay_conversion (op1);
3085 if (!really_overloaded_fn (op0))
3086 op0 = default_conversion (op0);
3087 if (!really_overloaded_fn (op1))
3088 op1 = default_conversion (op1);
3091 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3092 STRIP_TYPE_NOPS (op0);
3093 STRIP_TYPE_NOPS (op1);
3095 /* DTRT if one side is an overloaded function, but complain about it. */
3096 if (type_unknown_p (op0))
3098 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3099 if (t != error_mark_node)
3101 pedwarn ("assuming cast to type %qT from overloaded function",
3106 if (type_unknown_p (op1))
3108 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3109 if (t != error_mark_node)
3111 pedwarn ("assuming cast to type %qT from overloaded function",
3117 type0 = TREE_TYPE (op0);
3118 type1 = TREE_TYPE (op1);
3120 /* The expression codes of the data types of the arguments tell us
3121 whether the arguments are integers, floating, pointers, etc. */
3122 code0 = TREE_CODE (type0);
3123 code1 = TREE_CODE (type1);
3125 /* If an error was already reported for one of the arguments,
3126 avoid reporting another error. */
3128 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3129 return error_mark_node;
3131 if ((invalid_op_diag
3132 = targetm.invalid_binary_op (code, type0, type1)))
3134 error (invalid_op_diag);
3135 return error_mark_node;
3141 /* Subtraction of two similar pointers.
3142 We must subtract them as integers, then divide by object size. */
3143 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3144 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3146 return pointer_diff (op0, op1, common_type (type0, type1));
3147 /* In all other cases except pointer - int, the usual arithmetic
3149 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3154 /* The pointer - int case is just like pointer + int; fall
3157 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3158 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3162 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3163 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3164 if (processing_template_decl)
3166 result_type = TREE_TYPE (ptr_operand);
3169 return cp_pointer_int_sum (code,
3180 case TRUNC_DIV_EXPR:
3182 case FLOOR_DIV_EXPR:
3183 case ROUND_DIV_EXPR:
3184 case EXACT_DIV_EXPR:
3185 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3186 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3187 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3188 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3190 enum tree_code tcode0 = code0, tcode1 = code1;
3192 warn_for_div_by_zero (op1);
3194 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3195 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3196 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3197 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3199 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3200 resultcode = RDIV_EXPR;
3202 /* When dividing two signed integers, we have to promote to int.
3203 unless we divide by a constant != -1. Note that default
3204 conversion will have been performed on the operands at this
3205 point, so we have to dig out the original type to find out if
3207 shorten = ((TREE_CODE (op0) == NOP_EXPR
3208 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3209 || (TREE_CODE (op1) == INTEGER_CST
3210 && ! integer_all_onesp (op1)));
3219 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3220 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3221 && !VECTOR_FLOAT_TYPE_P (type0)
3222 && !VECTOR_FLOAT_TYPE_P (type1)))
3226 case TRUNC_MOD_EXPR:
3227 case FLOOR_MOD_EXPR:
3228 warn_for_div_by_zero (op1);
3230 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3232 /* Although it would be tempting to shorten always here, that loses
3233 on some targets, since the modulo instruction is undefined if the
3234 quotient can't be represented in the computation mode. We shorten
3235 only if unsigned or if dividing by something we know != -1. */
3236 shorten = ((TREE_CODE (op0) == NOP_EXPR
3237 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3238 || (TREE_CODE (op1) == INTEGER_CST
3239 && ! integer_all_onesp (op1)));
3244 case TRUTH_ANDIF_EXPR:
3245 case TRUTH_ORIF_EXPR:
3246 case TRUTH_AND_EXPR:
3248 result_type = boolean_type_node;
3251 /* Shift operations: result has same type as first operand;
3252 always convert second operand to int.
3253 Also set SHORT_SHIFT if shifting rightward. */
3256 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3258 result_type = type0;
3259 if (TREE_CODE (op1) == INTEGER_CST)
3261 if (tree_int_cst_lt (op1, integer_zero_node))
3262 warning (0, "right shift count is negative");
3265 if (! integer_zerop (op1))
3267 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3268 warning (0, "right shift count >= width of type");
3271 /* Convert the shift-count to an integer, regardless of
3272 size of value being shifted. */
3273 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3274 op1 = cp_convert (integer_type_node, op1);
3275 /* Avoid converting op1 to result_type later. */
3281 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3283 result_type = type0;
3284 if (TREE_CODE (op1) == INTEGER_CST)
3286 if (tree_int_cst_lt (op1, integer_zero_node))
3287 warning (0, "left shift count is negative");
3288 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3289 warning (0, "left shift count >= width of type");
3291 /* Convert the shift-count to an integer, regardless of
3292 size of value being shifted. */
3293 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3294 op1 = cp_convert (integer_type_node, op1);
3295 /* Avoid converting op1 to result_type later. */
3302 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3304 result_type = type0;
3305 if (TREE_CODE (op1) == INTEGER_CST)
3307 if (tree_int_cst_lt (op1, integer_zero_node))
3308 warning (0, (code == LROTATE_EXPR)
3309 ? G_("left rotate count is negative")
3310 : G_("right rotate count is negative"));
3311 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3312 warning (0, (code == LROTATE_EXPR)
3313 ? G_("left rotate count >= width of type")
3314 : G_("right rotate count >= width of type"));
3316 /* Convert the shift-count to an integer, regardless of
3317 size of value being shifted. */
3318 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3319 op1 = cp_convert (integer_type_node, op1);
3325 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3326 warning (OPT_Wfloat_equal,
3327 "comparing floating point with == or != is unsafe");
3328 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3329 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3330 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3332 build_type = boolean_type_node;
3333 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3334 || code0 == COMPLEX_TYPE)
3335 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3336 || code1 == COMPLEX_TYPE))
3338 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3339 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3340 result_type = composite_pointer_type (type0, type1, op0, op1,
3342 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3343 && null_ptr_cst_p (op1))
3345 if (TREE_CODE (op0) == ADDR_EXPR
3346 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3347 warning (OPT_Waddress, "the address of %qD will never be NULL",
3348 TREE_OPERAND (op0, 0));
3349 result_type = type0;
3351 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3352 && null_ptr_cst_p (op0))
3354 if (TREE_CODE (op1) == ADDR_EXPR
3355 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3356 warning (OPT_Waddress, "the address of %qD will never be NULL",
3357 TREE_OPERAND (op1, 0));
3358 result_type = type1;
3360 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3362 result_type = type0;
3363 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3365 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3367 result_type = type1;
3368 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3370 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3372 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3373 == ptrmemfunc_vbit_in_delta)
3375 tree pfn0 = pfn_from_ptrmemfunc (op0);
3376 tree delta0 = delta_from_ptrmemfunc (op0);
3377 tree e1 = cp_build_binary_op (EQ_EXPR,
3379 fold_convert (TREE_TYPE (pfn0),
3380 integer_zero_node));
3381 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3384 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3385 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3386 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3390 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3391 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3393 result_type = TREE_TYPE (op0);
3395 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3396 return cp_build_binary_op (code, op1, op0);
3397 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1))
3400 /* E will be the final comparison. */
3402 /* E1 and E2 are for scratch. */
3410 type = composite_pointer_type (type0, type1, op0, op1, "comparison");
3412 if (!same_type_p (TREE_TYPE (op0), type))
3413 op0 = cp_convert_and_check (type, op0);
3414 if (!same_type_p (TREE_TYPE (op1), type))
3415 op1 = cp_convert_and_check (type, op1);
3417 if (op0 == error_mark_node || op1 == error_mark_node)
3418 return error_mark_node;
3420 if (TREE_SIDE_EFFECTS (op0))
3421 op0 = save_expr (op0);
3422 if (TREE_SIDE_EFFECTS (op1))
3423 op1 = save_expr (op1);
3425 pfn0 = pfn_from_ptrmemfunc (op0);
3426 pfn1 = pfn_from_ptrmemfunc (op1);
3427 delta0 = delta_from_ptrmemfunc (op0);
3428 delta1 = delta_from_ptrmemfunc (op1);
3429 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3430 == ptrmemfunc_vbit_in_delta)
3435 && ((op0.delta == op1.delta)
3436 || (!op0.pfn && op0.delta & 1 == 0
3437 && op1.delta & 1 == 0))
3439 The reason for the `!op0.pfn' bit is that a NULL
3440 pointer-to-member is any member with a zero PFN and
3441 LSB of the DELTA field is 0. */
3443 e1 = cp_build_binary_op (BIT_AND_EXPR,
3446 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3447 e2 = cp_build_binary_op (BIT_AND_EXPR,
3450 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3451 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3452 e2 = cp_build_binary_op (EQ_EXPR,
3454 fold_convert (TREE_TYPE (pfn0),
3455 integer_zero_node));
3456 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3457 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3458 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3465 && (!op0.pfn || op0.delta == op1.delta))
3467 The reason for the `!op0.pfn' bit is that a NULL
3468 pointer-to-member is any member with a zero PFN; the
3469 DELTA field is unspecified. */
3471 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3472 e2 = cp_build_binary_op (EQ_EXPR,
3474 fold_convert (TREE_TYPE (pfn0),
3475 integer_zero_node));
3476 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3478 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3479 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3480 if (code == EQ_EXPR)
3482 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3486 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3487 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3489 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3490 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3498 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3499 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3501 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3502 result_type = composite_pointer_type (type0, type1, op0, op1,
3510 if (TREE_CODE (orig_op0) == STRING_CST
3511 || TREE_CODE (orig_op1) == STRING_CST)
3512 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3514 build_type = boolean_type_node;
3515 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3516 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3518 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3519 result_type = composite_pointer_type (type0, type1, op0, op1,
3521 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3522 && integer_zerop (op1))
3523 result_type = type0;
3524 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3525 && integer_zerop (op0))
3526 result_type = type1;
3527 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3529 result_type = type0;
3530 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3532 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3534 result_type = type1;
3535 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3539 case UNORDERED_EXPR:
3546 build_type = integer_type_node;
3547 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3549 error ("unordered comparison on non-floating point argument");
3550 return error_mark_node;
3559 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3560 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3561 || code1 == COMPLEX_TYPE)))
3562 arithmetic_types_p = 1;
3565 arithmetic_types_p = 0;
3566 /* Vector arithmetic is only allowed when both sides are vectors. */
3567 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3569 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3570 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3573 binary_op_error (code, type0, type1);
3574 return error_mark_node;
3576 arithmetic_types_p = 1;
3579 /* Determine the RESULT_TYPE, if it is not already known. */
3581 && arithmetic_types_p
3582 && (shorten || common || short_compare))
3583 result_type = common_type (type0, type1);
3587 error ("invalid operands of types %qT and %qT to binary %qO",
3588 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3589 return error_mark_node;
3592 /* If we're in a template, the only thing we need to know is the
3594 if (processing_template_decl)
3596 /* Since the middle-end checks the type when doing a build2, we
3597 need to build the tree in pieces. This built tree will never
3598 get out of the front-end as we replace it when instantiating
3600 tree tmp = build2 (resultcode,
3601 build_type ? build_type : result_type,
3603 TREE_OPERAND (tmp, 0) = op0;
3607 if (arithmetic_types_p)
3609 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3611 /* For certain operations (which identify themselves by shorten != 0)
3612 if both args were extended from the same smaller type,
3613 do the arithmetic in that type and then extend.
3615 shorten !=0 and !=1 indicates a bitwise operation.
3616 For them, this optimization is safe only if
3617 both args are zero-extended or both are sign-extended.
3618 Otherwise, we might change the result.
3619 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3620 but calculated in (unsigned short) it would be (unsigned short)-1. */
3622 if (shorten && none_complex)
3624 int unsigned0, unsigned1;
3625 tree arg0 = get_narrower (op0, &unsigned0);
3626 tree arg1 = get_narrower (op1, &unsigned1);
3627 /* UNS is 1 if the operation to be done is an unsigned one. */
3628 int uns = TYPE_UNSIGNED (result_type);
3631 final_type = result_type;
3633 /* Handle the case that OP0 does not *contain* a conversion
3634 but it *requires* conversion to FINAL_TYPE. */
3636 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3637 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3638 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3639 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3641 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3643 /* For bitwise operations, signedness of nominal type
3644 does not matter. Consider only how operands were extended. */
3648 /* Note that in all three cases below we refrain from optimizing
3649 an unsigned operation on sign-extended args.
3650 That would not be valid. */
3652 /* Both args variable: if both extended in same way
3653 from same width, do it in that width.
3654 Do it unsigned if args were zero-extended. */
3655 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3656 < TYPE_PRECISION (result_type))
3657 && (TYPE_PRECISION (TREE_TYPE (arg1))
3658 == TYPE_PRECISION (TREE_TYPE (arg0)))
3659 && unsigned0 == unsigned1
3660 && (unsigned0 || !uns))
3661 result_type = c_common_signed_or_unsigned_type
3662 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3663 else if (TREE_CODE (arg0) == INTEGER_CST
3664 && (unsigned1 || !uns)
3665 && (TYPE_PRECISION (TREE_TYPE (arg1))
3666 < TYPE_PRECISION (result_type))
3667 && (type = c_common_signed_or_unsigned_type
3668 (unsigned1, TREE_TYPE (arg1)),
3669 int_fits_type_p (arg0, type)))
3671 else if (TREE_CODE (arg1) == INTEGER_CST
3672 && (unsigned0 || !uns)
3673 && (TYPE_PRECISION (TREE_TYPE (arg0))
3674 < TYPE_PRECISION (result_type))
3675 && (type = c_common_signed_or_unsigned_type
3676 (unsigned0, TREE_TYPE (arg0)),
3677 int_fits_type_p (arg1, type)))
3681 /* Shifts can be shortened if shifting right. */
3686 tree arg0 = get_narrower (op0, &unsigned_arg);
3688 final_type = result_type;
3690 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3691 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3693 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3694 /* We can shorten only if the shift count is less than the
3695 number of bits in the smaller type size. */
3696 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3697 /* If arg is sign-extended and then unsigned-shifted,
3698 we can simulate this with a signed shift in arg's type
3699 only if the extended result is at least twice as wide
3700 as the arg. Otherwise, the shift could use up all the
3701 ones made by sign-extension and bring in zeros.
3702 We can't optimize that case at all, but in most machines
3703 it never happens because available widths are 2**N. */
3704 && (!TYPE_UNSIGNED (final_type)
3706 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3707 <= TYPE_PRECISION (result_type))))
3709 /* Do an unsigned shift if the operand was zero-extended. */
3711 = c_common_signed_or_unsigned_type (unsigned_arg,
3713 /* Convert value-to-be-shifted to that type. */
3714 if (TREE_TYPE (op0) != result_type)
3715 op0 = cp_convert (result_type, op0);
3720 /* Comparison operations are shortened too but differently.
3721 They identify themselves by setting short_compare = 1. */
3725 /* Don't write &op0, etc., because that would prevent op0
3726 from being kept in a register.
3727 Instead, make copies of the our local variables and
3728 pass the copies by reference, then copy them back afterward. */
3729 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3730 enum tree_code xresultcode = resultcode;
3732 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3734 return cp_convert (boolean_type_node, val);
3735 op0 = xop0, op1 = xop1;
3737 resultcode = xresultcode;
3740 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3741 && warn_sign_compare
3742 /* Do not warn until the template is instantiated; we cannot
3743 bound the ranges of the arguments until that point. */
3744 && !processing_template_decl)
3746 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3747 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3749 int unsignedp0, unsignedp1;
3750 tree primop0 = get_narrower (op0, &unsignedp0);
3751 tree primop1 = get_narrower (op1, &unsignedp1);
3753 /* Check for comparison of different enum types. */
3754 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3755 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3756 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3757 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3759 warning (OPT_Wsign_compare, "comparison between types %q#T and %q#T",
3760 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3763 /* Give warnings for comparisons between signed and unsigned
3764 quantities that may fail. */
3765 /* Do the checking based on the original operand trees, so that
3766 casts will be considered, but default promotions won't be. */
3768 /* Do not warn if the comparison is being done in a signed type,
3769 since the signed type will only be chosen if it can represent
3770 all the values of the unsigned type. */
3771 if (!TYPE_UNSIGNED (result_type))
3773 /* Do not warn if both operands are unsigned. */
3774 else if (op0_signed == op1_signed)
3776 /* Do not warn if the signed quantity is an unsuffixed
3777 integer literal (or some static constant expression
3778 involving such literals or a conditional expression
3779 involving such literals) and it is non-negative. */
3780 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3781 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3783 /* Do not warn if the comparison is an equality operation,
3784 the unsigned quantity is an integral constant and it does
3785 not use the most significant bit of result_type. */
3786 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3787 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3788 && int_fits_type_p (orig_op1, c_common_signed_type
3790 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3791 && int_fits_type_p (orig_op0, c_common_signed_type
3795 warning (OPT_Wsign_compare,
3796 "comparison between signed and unsigned integer expressions");
3798 /* Warn if two unsigned values are being compared in a size
3799 larger than their original size, and one (and only one) is the
3800 result of a `~' operator. This comparison will always fail.
3802 Also warn if one operand is a constant, and the constant does not
3803 have all bits set that are set in the ~ operand when it is
3806 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3807 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3809 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3810 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3811 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3812 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3814 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3817 HOST_WIDE_INT constant, mask;
3821 if (host_integerp (primop0, 0))
3824 unsignedp = unsignedp1;
3825 constant = tree_low_cst (primop0, 0);
3830 unsignedp = unsignedp0;
3831 constant = tree_low_cst (primop1, 0);
3834 bits = TYPE_PRECISION (TREE_TYPE (primop));
3835 if (bits < TYPE_PRECISION (result_type)
3836 && bits < HOST_BITS_PER_LONG && unsignedp)
3838 mask = (~ (HOST_WIDE_INT) 0) << bits;
3839 if ((mask & constant) != mask)
3840 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with constant");
3843 else if (unsignedp0 && unsignedp1
3844 && (TYPE_PRECISION (TREE_TYPE (primop0))
3845 < TYPE_PRECISION (result_type))
3846 && (TYPE_PRECISION (TREE_TYPE (primop1))
3847 < TYPE_PRECISION (result_type)))
3848 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with unsigned");
3853 /* Issue warnings about peculiar, but valid, uses of NULL. */
3854 if ((orig_op0 == null_node || orig_op1 == null_node)
3855 /* It's reasonable to use pointer values as operands of &&
3856 and ||, so NULL is no exception. */
3857 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3858 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3859 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3860 && code != EQ_EXPR && code != NE_EXPR)
3861 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3862 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3863 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3864 /* Some sort of arithmetic operation involving NULL was
3865 performed. Note that pointer-difference and pointer-addition
3866 have already been handled above, and so we don't end up here in
3868 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3871 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3872 Then the expression will be built.
3873 It will be given type FINAL_TYPE if that is nonzero;
3874 otherwise, it will be given type RESULT_TYPE. */
3877 if (TREE_TYPE (op0) != result_type)
3878 op0 = cp_convert_and_check (result_type, op0);
3879 if (TREE_TYPE (op1) != result_type)
3880 op1 = cp_convert_and_check (result_type, op1);
3882 if (op0 == error_mark_node || op1 == error_mark_node)
3883 return error_mark_node;
3886 if (build_type == NULL_TREE)
3887 build_type = result_type;
3889 result = build2 (resultcode, build_type, op0, op1);
3890 result = fold_if_not_in_template (result);
3891 if (final_type != 0)
3892 result = cp_convert (final_type, result);
3894 if (TREE_OVERFLOW_P (result)
3895 && !TREE_OVERFLOW_P (op0)
3896 && !TREE_OVERFLOW_P (op1))
3897 overflow_warning (result);
3902 /* Return a tree for the sum or difference (RESULTCODE says which)
3903 of pointer PTROP and integer INTOP. */
3906 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3908 tree res_type = TREE_TYPE (ptrop);
3910 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3911 in certain circumstance (when it's valid to do so). So we need
3912 to make sure it's complete. We don't need to check here, if we
3913 can actually complete it at all, as those checks will be done in
3914 pointer_int_sum() anyway. */
3915 complete_type (TREE_TYPE (res_type));
3917 return pointer_int_sum (resultcode, ptrop,
3918 fold_if_not_in_template (intop));
3921 /* Return a tree for the difference of pointers OP0 and OP1.
3922 The resulting tree has type int. */
3925 pointer_diff (tree op0, tree op1, tree ptrtype)
3928 tree restype = ptrdiff_type_node;
3929 tree target_type = TREE_TYPE (ptrtype);
3931 if (!complete_type_or_else (target_type, NULL_TREE))
3932 return error_mark_node;
3934 if (pedantic || warn_pointer_arith)
3936 if (TREE_CODE (target_type) == VOID_TYPE)
3937 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3938 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3939 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3940 if (TREE_CODE (target_type) == METHOD_TYPE)
3941 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3944 /* First do the subtraction as integers;
3945 then drop through to build the divide operator. */
3947 op0 = cp_build_binary_op (MINUS_EXPR,
3948 cp_convert (restype, op0),
3949 cp_convert (restype, op1));
3951 /* This generates an error if op1 is a pointer to an incomplete type. */
3952 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3953 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3955 op1 = (TYPE_PTROB_P (ptrtype)
3956 ? size_in_bytes (target_type)
3957 : integer_one_node);
3959 /* Do the division. */
3961 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3962 return fold_if_not_in_template (result);
3965 /* Construct and perhaps optimize a tree representation
3966 for a unary operation. CODE, a tree_code, specifies the operation
3967 and XARG is the operand. */
3970 build_x_unary_op (enum tree_code code, tree xarg)
3972 tree orig_expr = xarg;
3976 if (processing_template_decl)
3978 if (type_dependent_expression_p (xarg))
3979 return build_min_nt (code, xarg, NULL_TREE);
3981 xarg = build_non_dependent_expr (xarg);
3986 /* [expr.unary.op] says:
3988 The address of an object of incomplete type can be taken.
3990 (And is just the ordinary address operator, not an overloaded
3991 "operator &".) However, if the type is a template
3992 specialization, we must complete the type at this point so that
3993 an overloaded "operator &" will be available if required. */
3994 if (code == ADDR_EXPR
3995 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3996 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3997 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3998 || (TREE_CODE (xarg) == OFFSET_REF)))
3999 /* Don't look for a function. */;
4001 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
4002 /*overloaded_p=*/NULL);
4003 if (!exp && code == ADDR_EXPR)
4005 /* A pointer to member-function can be formed only by saying
4007 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
4008 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
4010 if (TREE_CODE (xarg) != OFFSET_REF
4011 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4013 error ("invalid use of %qE to form a pointer-to-member-function",
4015 if (TREE_CODE (xarg) != OFFSET_REF)
4016 inform (" a qualified-id is required");
4017 return error_mark_node;
4021 error ("parentheses around %qE cannot be used to form a"
4022 " pointer-to-member-function",
4024 PTRMEM_OK_P (xarg) = 1;
4028 if (TREE_CODE (xarg) == OFFSET_REF)
4030 ptrmem = PTRMEM_OK_P (xarg);
4032 if (!ptrmem && !flag_ms_extensions
4033 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4035 /* A single non-static member, make sure we don't allow a
4036 pointer-to-member. */
4037 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4038 TREE_OPERAND (xarg, 0),
4039 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4040 PTRMEM_OK_P (xarg) = ptrmem;
4043 else if (TREE_CODE (xarg) == TARGET_EXPR)
4044 warning (0, "taking address of temporary");
4045 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4048 if (processing_template_decl && exp != error_mark_node)
4049 exp = build_min_non_dep (code, exp, orig_expr,
4050 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4051 if (TREE_CODE (exp) == ADDR_EXPR)
4052 PTRMEM_OK_P (exp) = ptrmem;
4056 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4057 constants, where a null value is represented by an INTEGER_CST of
4061 cp_truthvalue_conversion (tree expr)
4063 tree type = TREE_TYPE (expr);
4064 if (TYPE_PTRMEM_P (type))
4065 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4067 return c_common_truthvalue_conversion (expr);
4070 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4073 condition_conversion (tree expr)
4076 if (processing_template_decl)
4078 t = perform_implicit_conversion (boolean_type_node, expr);
4079 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4083 /* Return an ADDR_EXPR giving the address of T. This function
4084 attempts no optimizations or simplifications; it is a low-level
4088 build_address (tree t)
4092 if (error_operand_p (t) || !cxx_mark_addressable (t))
4093 return error_mark_node;
4095 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4100 /* Return a NOP_EXPR converting EXPR to TYPE. */
4103 build_nop (tree type, tree expr)
4105 if (type == error_mark_node || error_operand_p (expr))
4107 return build1 (NOP_EXPR, type, expr);
4110 /* C++: Must handle pointers to members.
4112 Perhaps type instantiation should be extended to handle conversion
4113 from aggregates to types we don't yet know we want? (Or are those
4114 cases typically errors which should be reported?)
4116 NOCONVERT nonzero suppresses the default promotions
4117 (such as from short to int). */
4120 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4122 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4125 const char *errstring = NULL;
4127 const char *invalid_op_diag;
4129 if (arg == error_mark_node)
4130 return error_mark_node;
4132 if ((invalid_op_diag
4133 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4138 error (invalid_op_diag);
4139 return error_mark_node;
4144 case UNARY_PLUS_EXPR:
4147 int flags = WANT_ARITH | WANT_ENUM;
4148 /* Unary plus (but not unary minus) is allowed on pointers. */
4149 if (code == UNARY_PLUS_EXPR)
4150 flags |= WANT_POINTER;
4151 arg = build_expr_type_conversion (flags, arg, true);
4153 errstring = (code == NEGATE_EXPR
4154 ? "wrong type argument to unary minus"
4155 : "wrong type argument to unary plus");
4158 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4159 arg = perform_integral_promotions (arg);
4161 /* Make sure the result is not an lvalue: a unary plus or minus
4162 expression is always a rvalue. */
4169 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4173 arg = default_conversion (arg);
4175 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4178 errstring = "wrong type argument to bit-complement";
4179 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4180 arg = perform_integral_promotions (arg);
4184 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4185 errstring = "wrong type argument to abs";
4186 else if (!noconvert)
4187 arg = default_conversion (arg);
4191 /* Conjugating a real value is a no-op, but allow it anyway. */
4192 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4193 errstring = "wrong type argument to conjugation";
4194 else if (!noconvert)
4195 arg = default_conversion (arg);
4198 case TRUTH_NOT_EXPR:
4199 arg = perform_implicit_conversion (boolean_type_node, arg);
4200 val = invert_truthvalue (arg);
4201 if (arg != error_mark_node)
4203 errstring = "in argument to unary !";
4210 if (TREE_CODE (arg) == COMPLEX_CST)
4211 return TREE_REALPART (arg);
4212 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4214 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4215 return fold_if_not_in_template (arg);
4221 if (TREE_CODE (arg) == COMPLEX_CST)
4222 return TREE_IMAGPART (arg);
4223 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4225 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4226 return fold_if_not_in_template (arg);
4229 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4231 case PREINCREMENT_EXPR:
4232 case POSTINCREMENT_EXPR:
4233 case PREDECREMENT_EXPR:
4234 case POSTDECREMENT_EXPR:
4235 /* Handle complex lvalues (when permitted)
4236 by reduction to simpler cases. */
4238 val = unary_complex_lvalue (code, arg);
4242 /* Increment or decrement the real part of the value,
4243 and don't change the imaginary part. */
4244 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4248 arg = stabilize_reference (arg);
4249 real = build_unary_op (REALPART_EXPR, arg, 1);
4250 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4251 real = build_unary_op (code, real, 1);
4252 if (real == error_mark_node || imag == error_mark_node)
4253 return error_mark_node;
4254 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4258 /* Report invalid types. */
4260 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4263 if (code == PREINCREMENT_EXPR)
4264 errstring ="no pre-increment operator for type";
4265 else if (code == POSTINCREMENT_EXPR)
4266 errstring ="no post-increment operator for type";
4267 else if (code == PREDECREMENT_EXPR)
4268 errstring ="no pre-decrement operator for type";
4270 errstring ="no post-decrement operator for type";
4273 else if (arg == error_mark_node)
4274 return error_mark_node;
4276 /* Report something read-only. */
4278 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4279 || TREE_READONLY (arg))
4280 readonly_error (arg, ((code == PREINCREMENT_EXPR
4281 || code == POSTINCREMENT_EXPR)
4282 ? "increment" : "decrement"));
4287 tree result_type = TREE_TYPE (arg);
4289 declared_type = unlowered_expr_type (arg);
4291 arg = get_unwidened (arg, 0);
4292 argtype = TREE_TYPE (arg);
4294 /* ARM $5.2.5 last annotation says this should be forbidden. */
4295 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4296 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4297 ? G_("ISO C++ forbids incrementing an enum")
4298 : G_("ISO C++ forbids decrementing an enum"));
4300 /* Compute the increment. */
4302 if (TREE_CODE (argtype) == POINTER_TYPE)
4304 tree type = complete_type (TREE_TYPE (argtype));
4306 if (!COMPLETE_OR_VOID_TYPE_P (type))
4307 error (((code == PREINCREMENT_EXPR
4308 || code == POSTINCREMENT_EXPR))
4309 ? G_("cannot increment a pointer to incomplete type %qT")
4310 : G_("cannot decrement a pointer to incomplete type %qT"),
4311 TREE_TYPE (argtype));
4312 else if ((pedantic || warn_pointer_arith)
4313 && !TYPE_PTROB_P (argtype))
4314 pedwarn ((code == PREINCREMENT_EXPR
4315 || code == POSTINCREMENT_EXPR)
4316 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4317 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4319 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4322 inc = integer_one_node;
4324 inc = cp_convert (argtype, inc);
4326 /* Complain about anything else that is not a true lvalue. */
4327 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4328 || code == POSTINCREMENT_EXPR)
4329 ? lv_increment : lv_decrement)))
4330 return error_mark_node;
4332 /* Forbid using -- on `bool'. */
4333 if (same_type_p (declared_type, boolean_type_node))
4335 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4337 error ("invalid use of Boolean expression as operand "
4338 "to %<operator--%>");
4339 return error_mark_node;
4341 val = boolean_increment (code, arg);
4344 val = build2 (code, TREE_TYPE (arg), arg, inc);
4346 TREE_SIDE_EFFECTS (val) = 1;
4347 return cp_convert (result_type, val);
4351 /* Note that this operation never does default_conversion
4352 regardless of NOCONVERT. */
4354 argtype = lvalue_type (arg);
4356 if (TREE_CODE (arg) == OFFSET_REF)
4359 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4361 tree type = build_pointer_type (TREE_TYPE (argtype));
4362 arg = build1 (CONVERT_EXPR, type, arg);
4365 else if (pedantic && DECL_MAIN_P (arg))
4367 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4369 /* Let &* cancel out to simplify resulting code. */
4370 if (TREE_CODE (arg) == INDIRECT_REF)
4372 /* We don't need to have `current_class_ptr' wrapped in a
4373 NON_LVALUE_EXPR node. */
4374 if (arg == current_class_ref)
4375 return current_class_ptr;
4377 arg = TREE_OPERAND (arg, 0);
4378 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4380 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4381 arg = build1 (CONVERT_EXPR, type, arg);
4384 /* Don't let this be an lvalue. */
4389 /* Uninstantiated types are all functions. Taking the
4390 address of a function is a no-op, so just return the
4393 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4394 || !IDENTIFIER_OPNAME_P (arg));
4396 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4397 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4399 /* They're trying to take the address of a unique non-static
4400 member function. This is ill-formed (except in MS-land),
4401 but let's try to DTRT.
4402 Note: We only handle unique functions here because we don't
4403 want to complain if there's a static overload; non-unique
4404 cases will be handled by instantiate_type. But we need to
4405 handle this case here to allow casts on the resulting PMF.
4406 We could defer this in non-MS mode, but it's easier to give
4407 a useful error here. */
4409 /* Inside constant member functions, the `this' pointer
4410 contains an extra const qualifier. TYPE_MAIN_VARIANT
4411 is used here to remove this const from the diagnostics
4412 and the created OFFSET_REF. */
4413 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4414 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4417 if (! flag_ms_extensions)
4419 tree name = DECL_NAME (fn);
4420 if (current_class_type
4421 && TREE_OPERAND (arg, 0) == current_class_ref)
4422 /* An expression like &memfn. */
4423 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4424 " or parenthesized non-static member function to form"
4425 " a pointer to member function. Say %<&%T::%D%>",
4428 pedwarn ("ISO C++ forbids taking the address of a bound member"
4429 " function to form a pointer to member function."
4433 arg = build_offset_ref (base, fn, /*address_p=*/true);
4437 if (type_unknown_p (arg))
4438 return build1 (ADDR_EXPR, unknown_type_node, arg);
4440 /* Handle complex lvalues (when permitted)
4441 by reduction to simpler cases. */
4442 val = unary_complex_lvalue (code, arg);
4446 switch (TREE_CODE (arg))
4451 case FIX_TRUNC_EXPR:
4452 if (! lvalue_p (arg) && pedantic)
4453 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4457 arg = BASELINK_FUNCTIONS (arg);
4461 arg = OVL_CURRENT (arg);
4465 /* Turn a reference to a non-static data member into a
4466 pointer-to-member. */
4471 if (!PTRMEM_OK_P (arg))
4472 return build_unary_op (code, arg, 0);
4474 t = TREE_OPERAND (arg, 1);
4475 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4477 error ("cannot create pointer to reference member %qD", t);
4478 return error_mark_node;
4481 type = build_ptrmem_type (context_for_name_lookup (t),
4483 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4491 /* Anything not already handled and not a true memory reference
4493 if (TREE_CODE (argtype) != FUNCTION_TYPE
4494 && TREE_CODE (argtype) != METHOD_TYPE
4495 && TREE_CODE (arg) != OFFSET_REF
4496 && !lvalue_or_else (arg, lv_addressof))
4497 return error_mark_node;
4499 if (argtype != error_mark_node)
4500 argtype = build_pointer_type (argtype);
4502 /* In a template, we are processing a non-dependent expression
4503 so we can just form an ADDR_EXPR with the correct type. */
4504 if (processing_template_decl)
4506 val = build_address (arg);
4507 if (TREE_CODE (arg) == OFFSET_REF)
4508 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4512 if (TREE_CODE (arg) != COMPONENT_REF)
4514 val = build_address (arg);
4515 if (TREE_CODE (arg) == OFFSET_REF)
4516 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4518 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4520 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4522 /* We can only get here with a single static member
4524 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4525 && DECL_STATIC_FUNCTION_P (fn));
4527 val = build_address (fn);
4528 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4529 /* Do not lose object's side effects. */
4530 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4531 TREE_OPERAND (arg, 0), val);
4533 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4535 error ("attempt to take address of bit-field structure member %qD",
4536 TREE_OPERAND (arg, 1));
4537 return error_mark_node;
4541 tree object = TREE_OPERAND (arg, 0);
4542 tree field = TREE_OPERAND (arg, 1);
4543 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4544 (TREE_TYPE (object), decl_type_context (field)));
4545 val = build_address (arg);
4548 if (TREE_CODE (argtype) == POINTER_TYPE
4549 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4551 build_ptrmemfunc_type (argtype);
4552 val = build_ptrmemfunc (argtype, val, 0,
4553 /*c_cast_p=*/false);
4565 argtype = TREE_TYPE (arg);
4566 return fold_if_not_in_template (build1 (code, argtype, arg));
4569 error ("%s", errstring);
4570 return error_mark_node;
4573 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4574 for certain kinds of expressions which are not really lvalues
4575 but which we can accept as lvalues.
4577 If ARG is not a kind of expression we can handle, return
4581 unary_complex_lvalue (enum tree_code code, tree arg)
4583 /* Inside a template, making these kinds of adjustments is
4584 pointless; we are only concerned with the type of the
4586 if (processing_template_decl)
4589 /* Handle (a, b) used as an "lvalue". */
4590 if (TREE_CODE (arg) == COMPOUND_EXPR)
4592 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4593 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4594 TREE_OPERAND (arg, 0), real_result);
4597 /* Handle (a ? b : c) used as an "lvalue". */
4598 if (TREE_CODE (arg) == COND_EXPR
4599 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4600 return rationalize_conditional_expr (code, arg);
4602 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4603 if (TREE_CODE (arg) == MODIFY_EXPR
4604 || TREE_CODE (arg) == PREINCREMENT_EXPR
4605 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4607 tree lvalue = TREE_OPERAND (arg, 0);
4608 if (TREE_SIDE_EFFECTS (lvalue))
4610 lvalue = stabilize_reference (lvalue);
4611 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4612 lvalue, TREE_OPERAND (arg, 1));
4614 return unary_complex_lvalue
4615 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4618 if (code != ADDR_EXPR)
4621 /* Handle (a = b) used as an "lvalue" for `&'. */
4622 if (TREE_CODE (arg) == MODIFY_EXPR
4623 || TREE_CODE (arg) == INIT_EXPR)
4625 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4626 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4628 TREE_NO_WARNING (arg) = 1;
4632 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4633 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4634 || TREE_CODE (arg) == OFFSET_REF)
4637 /* We permit compiler to make function calls returning
4638 objects of aggregate type look like lvalues. */
4642 if (TREE_CODE (targ) == SAVE_EXPR)
4643 targ = TREE_OPERAND (targ, 0);
4645 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4647 if (TREE_CODE (arg) == SAVE_EXPR)
4650 targ = build_cplus_new (TREE_TYPE (arg), arg);
4651 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4654 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4655 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4656 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4659 /* Don't let anything else be handled specially. */
4663 /* Mark EXP saying that we need to be able to take the
4664 address of it; it should not be allocated in a register.
4665 Value is true if successful.
4667 C++: we do not allow `current_class_ptr' to be addressable. */
4670 cxx_mark_addressable (tree exp)
4675 switch (TREE_CODE (x))
4682 x = TREE_OPERAND (x, 0);
4686 if (x == current_class_ptr)
4688 error ("cannot take the address of %<this%>, which is an rvalue expression");
4689 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4695 /* Caller should not be trying to mark initialized
4696 constant fields addressable. */
4697 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4698 || DECL_IN_AGGR_P (x) == 0
4700 || DECL_EXTERNAL (x));
4705 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4706 && !DECL_ARTIFICIAL (x))
4708 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4711 ("address of explicit register variable %qD requested", x);
4714 else if (extra_warnings)
4716 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4718 TREE_ADDRESSABLE (x) = 1;
4722 TREE_ADDRESSABLE (x) = 1;
4726 TREE_ADDRESSABLE (x) = 1;
4730 TREE_ADDRESSABLE (x) = 1;
4731 cxx_mark_addressable (TREE_OPERAND (x, 0));
4739 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4742 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4744 tree orig_ifexp = ifexp;
4745 tree orig_op1 = op1;
4746 tree orig_op2 = op2;
4749 if (processing_template_decl)
4751 /* The standard says that the expression is type-dependent if
4752 IFEXP is type-dependent, even though the eventual type of the
4753 expression doesn't dependent on IFEXP. */
4754 if (type_dependent_expression_p (ifexp)
4755 /* As a GNU extension, the middle operand may be omitted. */
4756 || (op1 && type_dependent_expression_p (op1))
4757 || type_dependent_expression_p (op2))
4758 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4759 ifexp = build_non_dependent_expr (ifexp);
4761 op1 = build_non_dependent_expr (op1);
4762 op2 = build_non_dependent_expr (op2);
4765 expr = build_conditional_expr (ifexp, op1, op2);
4766 if (processing_template_decl && expr != error_mark_node)
4767 return build_min_non_dep (COND_EXPR, expr,
4768 orig_ifexp, orig_op1, orig_op2);
4772 /* Given a list of expressions, return a compound expression
4773 that performs them all and returns the value of the last of them. */
4775 tree build_x_compound_expr_from_list (tree list, const char *msg)
4777 tree expr = TREE_VALUE (list);
4779 if (TREE_CHAIN (list))
4782 pedwarn ("%s expression list treated as compound expression", msg);
4784 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4785 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4791 /* Handle overloading of the ',' operator when needed. */
4794 build_x_compound_expr (tree op1, tree op2)
4797 tree orig_op1 = op1;
4798 tree orig_op2 = op2;
4800 if (processing_template_decl)
4802 if (type_dependent_expression_p (op1)
4803 || type_dependent_expression_p (op2))
4804 return build_min_nt (COMPOUND_EXPR, op1, op2);
4805 op1 = build_non_dependent_expr (op1);
4806 op2 = build_non_dependent_expr (op2);
4809 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4810 /*overloaded_p=*/NULL);
4812 result = build_compound_expr (op1, op2);
4814 if (processing_template_decl && result != error_mark_node)
4815 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4820 /* Build a compound expression. */
4823 build_compound_expr (tree lhs, tree rhs)
4825 lhs = convert_to_void (lhs, "left-hand operand of comma");
4827 if (lhs == error_mark_node || rhs == error_mark_node)
4828 return error_mark_node;
4830 if (TREE_CODE (rhs) == TARGET_EXPR)
4832 /* If the rhs is a TARGET_EXPR, then build the compound
4833 expression inside the target_expr's initializer. This
4834 helps the compiler to eliminate unnecessary temporaries. */
4835 tree init = TREE_OPERAND (rhs, 1);
4837 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4838 TREE_OPERAND (rhs, 1) = init;
4843 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4846 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4847 casts away constness. DIAG_FN gives the function to call if we
4848 need to issue a diagnostic; if it is NULL, no diagnostic will be
4849 issued. DESCRIPTION explains what operation is taking place. */
4852 check_for_casting_away_constness (tree src_type, tree dest_type,
4853 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4854 const char *description)
4856 if (diag_fn && casts_away_constness (src_type, dest_type))
4857 diag_fn ("%s from type %qT to type %qT casts away constness",
4858 description, src_type, dest_type);
4861 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4862 (another pointer-to-member type in the same hierarchy) and return
4863 the converted expression. If ALLOW_INVERSE_P is permitted, a
4864 pointer-to-derived may be converted to pointer-to-base; otherwise,
4865 only the other direction is permitted. If C_CAST_P is true, this
4866 conversion is taking place as part of a C-style cast. */
4869 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4872 if (TYPE_PTRMEM_P (type))
4876 if (TREE_CODE (expr) == PTRMEM_CST)
4877 expr = cplus_expand_constant (expr);
4878 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4879 TYPE_PTRMEM_CLASS_TYPE (type),
4882 if (!integer_zerop (delta))
4884 tree cond, op1, op2;
4886 cond = cp_build_binary_op (EQ_EXPR,
4888 build_int_cst (TREE_TYPE (expr), -1));
4889 op1 = build_nop (ptrdiff_type_node, expr);
4890 op2 = cp_build_binary_op (PLUS_EXPR, op1, delta);
4892 expr = fold_build3 (COND_EXPR, ptrdiff_type_node, cond, op1, op2);
4896 return build_nop (type, expr);
4899 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4900 allow_inverse_p, c_cast_p);
4903 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4904 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4905 Otherwise, return EXPR unchanged. */
4908 ignore_overflows (tree expr, tree orig)
4910 if (TREE_CODE (expr) == INTEGER_CST
4911 && CONSTANT_CLASS_P (orig)
4912 && TREE_CODE (orig) != STRING_CST
4913 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4915 if (!TREE_OVERFLOW (orig))
4916 /* Ensure constant sharing. */
4917 expr = build_int_cst_wide (TREE_TYPE (expr),
4918 TREE_INT_CST_LOW (expr),
4919 TREE_INT_CST_HIGH (expr));
4922 /* Avoid clobbering a shared constant. */
4923 expr = copy_node (expr);
4924 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4930 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4931 this static_cast is being attempted as one of the possible casts
4932 allowed by a C-style cast. (In that case, accessibility of base
4933 classes is not considered, and it is OK to cast away
4934 constness.) Return the result of the cast. *VALID_P is set to
4935 indicate whether or not the cast was valid. */
4938 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4944 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4947 /* Assume the cast is valid. */
4950 intype = TREE_TYPE (expr);
4952 /* Save casted types in the function's used types hash table. */
4953 used_types_insert (type);
4955 /* Determine what to do when casting away constness. */
4958 /* C-style casts are allowed to cast away constness. With
4959 WARN_CAST_QUAL, we still want to issue a warning. */
4960 diag_fn = warn_cast_qual ? warning0 : NULL;
4965 /* A static_cast may not cast away constness. */
4967 desc = "static_cast";
4970 /* [expr.static.cast]
4972 An lvalue of type "cv1 B", where B is a class type, can be cast
4973 to type "reference to cv2 D", where D is a class derived (clause
4974 _class.derived_) from B, if a valid standard conversion from
4975 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4976 same cv-qualification as, or greater cv-qualification than, cv1,
4977 and B is not a virtual base class of D. */
4978 /* We check this case before checking the validity of "TYPE t =
4979 EXPR;" below because for this case:
4982 struct D : public B { D(const B&); };
4984 void f() { static_cast<const D&>(b); }
4986 we want to avoid constructing a new D. The standard is not
4987 completely clear about this issue, but our interpretation is
4988 consistent with other compilers. */
4989 if (TREE_CODE (type) == REFERENCE_TYPE
4990 && CLASS_TYPE_P (TREE_TYPE (type))
4991 && CLASS_TYPE_P (intype)
4992 && real_lvalue_p (expr)
4993 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4994 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4995 build_pointer_type (TYPE_MAIN_VARIANT
4996 (TREE_TYPE (type))))
4998 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
5002 /* There is a standard conversion from "D*" to "B*" even if "B"
5003 is ambiguous or inaccessible. If this is really a
5004 static_cast, then we check both for inaccessibility and
5005 ambiguity. However, if this is a static_cast being performed
5006 because the user wrote a C-style cast, then accessibility is
5008 base = lookup_base (TREE_TYPE (type), intype,
5009 c_cast_p ? ba_unique : ba_check,
5012 /* Convert from "B*" to "D*". This function will check that "B"
5013 is not a virtual base of "D". */
5014 expr = build_base_path (MINUS_EXPR, build_address (expr),
5015 base, /*nonnull=*/false);
5016 /* Convert the pointer to a reference -- but then remember that
5017 there are no expressions with reference type in C++. */
5018 return convert_from_reference (build_nop (type, expr));
5023 /* [expr.static.cast]
5025 An expression e can be explicitly converted to a type T using a
5026 static_cast of the form static_cast<T>(e) if the declaration T
5027 t(e);" is well-formed, for some invented temporary variable
5029 result = perform_direct_initialization_if_possible (type, expr,
5033 result = convert_from_reference (result);
5035 /* Ignore any integer overflow caused by the cast. */
5036 result = ignore_overflows (result, orig);
5038 /* [expr.static.cast]
5040 If T is a reference type, the result is an lvalue; otherwise,
5041 the result is an rvalue. */
5042 if (TREE_CODE (type) != REFERENCE_TYPE)
5043 result = rvalue (result);
5047 /* [expr.static.cast]
5049 Any expression can be explicitly converted to type cv void. */
5050 if (TREE_CODE (type) == VOID_TYPE)
5051 return convert_to_void (expr, /*implicit=*/NULL);
5053 /* [expr.static.cast]
5055 The inverse of any standard conversion sequence (clause _conv_),
5056 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5057 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5058 (_conv.bool_) conversions, can be performed explicitly using
5059 static_cast subject to the restriction that the explicit
5060 conversion does not cast away constness (_expr.const.cast_), and
5061 the following additional rules for specific cases: */
5062 /* For reference, the conversions not excluded are: integral
5063 promotions, floating point promotion, integral conversions,
5064 floating point conversions, floating-integral conversions,
5065 pointer conversions, and pointer to member conversions. */
5068 A value of integral _or enumeration_ type can be explicitly
5069 converted to an enumeration type. */
5070 /* The effect of all that is that any conversion between any two
5071 types which are integral, floating, or enumeration types can be
5073 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5074 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5076 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5078 /* Ignore any integer overflow caused by the cast. */
5079 expr = ignore_overflows (expr, orig);
5083 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5084 && CLASS_TYPE_P (TREE_TYPE (type))
5085 && CLASS_TYPE_P (TREE_TYPE (intype))
5086 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5087 (TREE_TYPE (intype))),
5088 build_pointer_type (TYPE_MAIN_VARIANT
5089 (TREE_TYPE (type)))))
5094 check_for_casting_away_constness (intype, type, diag_fn, desc);
5095 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5096 c_cast_p ? ba_unique : ba_check,
5098 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5101 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5102 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5109 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5110 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5112 if (TYPE_PTRMEM_P (type))
5114 t1 = (build_ptrmem_type
5116 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5117 t2 = (build_ptrmem_type
5119 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5126 if (can_convert (t1, t2) || can_convert (t2, t1))
5129 check_for_casting_away_constness (intype, type, diag_fn,
5131 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5136 /* [expr.static.cast]
5138 An rvalue of type "pointer to cv void" can be explicitly
5139 converted to a pointer to object type. A value of type pointer
5140 to object converted to "pointer to cv void" and back to the
5141 original pointer type will have its original value. */
5142 if (TREE_CODE (intype) == POINTER_TYPE
5143 && VOID_TYPE_P (TREE_TYPE (intype))
5144 && TYPE_PTROB_P (type))
5147 check_for_casting_away_constness (intype, type, diag_fn, desc);
5148 return build_nop (type, expr);
5152 return error_mark_node;
5155 /* Return an expression representing static_cast<TYPE>(EXPR). */
5158 build_static_cast (tree type, tree expr)
5163 if (type == error_mark_node || expr == error_mark_node)
5164 return error_mark_node;
5166 if (processing_template_decl)
5168 expr = build_min (STATIC_CAST_EXPR, type, expr);
5169 /* We don't know if it will or will not have side effects. */
5170 TREE_SIDE_EFFECTS (expr) = 1;
5171 return convert_from_reference (expr);
5174 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5175 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5176 if (TREE_CODE (type) != REFERENCE_TYPE
5177 && TREE_CODE (expr) == NOP_EXPR
5178 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5179 expr = TREE_OPERAND (expr, 0);
5181 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5185 error ("invalid static_cast from type %qT to type %qT",
5186 TREE_TYPE (expr), type);
5187 return error_mark_node;
5190 /* EXPR is an expression with member function or pointer-to-member
5191 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5192 not permitted by ISO C++, but we accept it in some modes. If we
5193 are not in one of those modes, issue a diagnostic. Return the
5194 converted expression. */
5197 convert_member_func_to_ptr (tree type, tree expr)
5202 intype = TREE_TYPE (expr);
5203 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5204 || TREE_CODE (intype) == METHOD_TYPE);
5206 if (pedantic || warn_pmf2ptr)
5207 pedwarn ("converting from %qT to %qT", intype, type);
5209 if (TREE_CODE (intype) == METHOD_TYPE)
5210 expr = build_addr_func (expr);
5211 else if (TREE_CODE (expr) == PTRMEM_CST)
5212 expr = build_address (PTRMEM_CST_MEMBER (expr));
5215 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5216 decl = build_address (decl);
5217 expr = get_member_function_from_ptrfunc (&decl, expr);
5220 return build_nop (type, expr);
5223 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5224 If C_CAST_P is true, this reinterpret cast is being done as part of
5225 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5226 indicate whether or not reinterpret_cast was valid. */
5229 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5234 /* Assume the cast is invalid. */
5238 if (type == error_mark_node || error_operand_p (expr))
5239 return error_mark_node;
5241 intype = TREE_TYPE (expr);
5243 /* Save casted types in the function's used types hash table. */
5244 used_types_insert (type);
5246 /* [expr.reinterpret.cast]
5247 An lvalue expression of type T1 can be cast to the type
5248 "reference to T2" if an expression of type "pointer to T1" can be
5249 explicitly converted to the type "pointer to T2" using a
5250 reinterpret_cast. */
5251 if (TREE_CODE (type) == REFERENCE_TYPE)
5253 if (! real_lvalue_p (expr))
5255 error ("invalid cast of an rvalue expression of type "
5258 return error_mark_node;
5261 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5262 "B" are related class types; the reinterpret_cast does not
5263 adjust the pointer. */
5264 if (TYPE_PTR_P (intype)
5265 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5266 COMPARE_BASE | COMPARE_DERIVED)))
5267 warning (0, "casting %qT to %qT does not dereference pointer",
5270 expr = build_unary_op (ADDR_EXPR, expr, 0);
5271 if (expr != error_mark_node)
5272 expr = build_reinterpret_cast_1
5273 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5275 if (expr != error_mark_node)
5276 expr = build_indirect_ref (expr, 0);
5280 /* As a G++ extension, we consider conversions from member
5281 functions, and pointers to member functions to
5282 pointer-to-function and pointer-to-void types. If
5283 -Wno-pmf-conversions has not been specified,
5284 convert_member_func_to_ptr will issue an error message. */
5285 if ((TYPE_PTRMEMFUNC_P (intype)
5286 || TREE_CODE (intype) == METHOD_TYPE)
5287 && TYPE_PTR_P (type)
5288 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5289 || VOID_TYPE_P (TREE_TYPE (type))))
5290 return convert_member_func_to_ptr (type, expr);
5292 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5293 array-to-pointer, and function-to-pointer conversions are
5295 expr = decay_conversion (expr);
5297 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5298 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5299 if (TREE_CODE (expr) == NOP_EXPR
5300 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5301 expr = TREE_OPERAND (expr, 0);
5303 if (error_operand_p (expr))
5304 return error_mark_node;
5306 intype = TREE_TYPE (expr);
5308 /* [expr.reinterpret.cast]
5309 A pointer can be converted to any integral type large enough to
5311 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5313 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5314 pedwarn ("cast from %qT to %qT loses precision",
5317 /* [expr.reinterpret.cast]
5318 A value of integral or enumeration type can be explicitly
5319 converted to a pointer. */
5320 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5323 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5324 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5325 return fold_if_not_in_template (build_nop (type, expr));
5326 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5327 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5332 check_for_casting_away_constness (intype, type, error,
5333 "reinterpret_cast");
5334 /* Warn about possible alignment problems. */
5335 if (STRICT_ALIGNMENT && warn_cast_align
5336 && !VOID_TYPE_P (type)
5337 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5338 && COMPLETE_TYPE_P (TREE_TYPE (type))
5339 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5340 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5341 warning (0, "cast from %qT to %qT increases required alignment of "
5345 /* We need to strip nops here, because the front end likes to
5346 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5348 if (warn_strict_aliasing <= 2)
5349 strict_aliasing_warning (intype, type, sexpr);
5351 return fold_if_not_in_template (build_nop (type, expr));
5353 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5354 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5357 /* Only issue a warning, as we have always supported this
5358 where possible, and it is necessary in some cases. DR 195
5359 addresses this issue, but as of 2004/10/26 is still in
5361 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5362 return fold_if_not_in_template (build_nop (type, expr));
5364 else if (TREE_CODE (type) == VECTOR_TYPE)
5365 return fold_if_not_in_template (convert_to_vector (type, expr));
5366 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5367 return fold_if_not_in_template (convert_to_integer (type, expr));
5372 error ("invalid cast from type %qT to type %qT", intype, type);
5373 return error_mark_node;
5376 return cp_convert (type, expr);
5380 build_reinterpret_cast (tree type, tree expr)
5382 if (type == error_mark_node || expr == error_mark_node)
5383 return error_mark_node;
5385 if (processing_template_decl)
5387 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5389 if (!TREE_SIDE_EFFECTS (t)
5390 && type_dependent_expression_p (expr))
5391 /* There might turn out to be side effects inside expr. */
5392 TREE_SIDE_EFFECTS (t) = 1;
5393 return convert_from_reference (t);
5396 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5400 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5401 return an appropriate expression. Otherwise, return
5402 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5403 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5404 performing a C-style cast, its value upon return will indicate
5405 whether or not the conversion succeeded. */
5408 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5412 tree reference_type;
5414 /* Callers are responsible for handling error_mark_node as a
5415 destination type. */
5416 gcc_assert (dst_type != error_mark_node);
5417 /* In a template, callers should be building syntactic
5418 representations of casts, not using this machinery. */
5419 gcc_assert (!processing_template_decl);
5421 /* Assume the conversion is invalid. */
5425 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5428 error ("invalid use of const_cast with type %qT, "
5429 "which is not a pointer, "
5430 "reference, nor a pointer-to-data-member type", dst_type);
5431 return error_mark_node;
5434 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5437 error ("invalid use of const_cast with type %qT, which is a pointer "
5438 "or reference to a function type", dst_type);
5439 return error_mark_node;
5442 /* Save casted types in the function's used types hash table. */
5443 used_types_insert (dst_type);
5445 src_type = TREE_TYPE (expr);
5446 /* Expressions do not really have reference types. */
5447 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5448 src_type = TREE_TYPE (src_type);
5450 /* [expr.const.cast]
5452 An lvalue of type T1 can be explicitly converted to an lvalue of
5453 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5454 types) if a pointer to T1 can be explicitly converted to the type
5455 pointer to T2 using a const_cast. */
5456 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5458 reference_type = dst_type;
5459 if (! real_lvalue_p (expr))
5462 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5463 src_type, dst_type);
5464 return error_mark_node;
5466 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5467 src_type = build_pointer_type (src_type);
5471 reference_type = NULL_TREE;
5472 /* If the destination type is not a reference type, the
5473 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5474 conversions are performed. */
5475 src_type = type_decays_to (src_type);
5476 if (src_type == error_mark_node)
5477 return error_mark_node;
5480 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5481 && comp_ptr_ttypes_const (dst_type, src_type))
5486 /* This cast is actually a C-style cast. Issue a warning if
5487 the user is making a potentially unsafe cast. */
5489 check_for_casting_away_constness (src_type, dst_type,
5495 expr = build_unary_op (ADDR_EXPR, expr, 0);
5496 expr = build_nop (reference_type, expr);
5497 return convert_from_reference (expr);
5501 expr = decay_conversion (expr);
5502 /* build_c_cast puts on a NOP_EXPR to make the result not an
5503 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5504 non-lvalue context. */
5505 if (TREE_CODE (expr) == NOP_EXPR
5506 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5507 expr = TREE_OPERAND (expr, 0);
5508 return build_nop (dst_type, expr);
5513 error ("invalid const_cast from type %qT to type %qT",
5514 src_type, dst_type);
5515 return error_mark_node;
5519 build_const_cast (tree type, tree expr)
5521 if (type == error_mark_node || error_operand_p (expr))
5522 return error_mark_node;
5524 if (processing_template_decl)
5526 tree t = build_min (CONST_CAST_EXPR, type, expr);
5528 if (!TREE_SIDE_EFFECTS (t)
5529 && type_dependent_expression_p (expr))
5530 /* There might turn out to be side effects inside expr. */
5531 TREE_SIDE_EFFECTS (t) = 1;
5532 return convert_from_reference (t);
5535 return build_const_cast_1 (type, expr, /*complain=*/true,
5539 /* Build an expression representing an explicit C-style cast to type
5540 TYPE of expression EXPR. */
5543 build_c_cast (tree type, tree expr)
5549 if (type == error_mark_node || error_operand_p (expr))
5550 return error_mark_node;
5552 if (processing_template_decl)
5554 tree t = build_min (CAST_EXPR, type,
5555 tree_cons (NULL_TREE, value, NULL_TREE));
5556 /* We don't know if it will or will not have side effects. */
5557 TREE_SIDE_EFFECTS (t) = 1;
5558 return convert_from_reference (t);
5561 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5562 'Class') should always be retained, because this information aids
5563 in method lookup. */
5564 if (objc_is_object_ptr (type)
5565 && objc_is_object_ptr (TREE_TYPE (expr)))
5566 return build_nop (type, expr);
5568 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5569 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5570 if (TREE_CODE (type) != REFERENCE_TYPE
5571 && TREE_CODE (value) == NOP_EXPR
5572 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5573 value = TREE_OPERAND (value, 0);
5575 if (TREE_CODE (type) == ARRAY_TYPE)
5577 /* Allow casting from T1* to T2[] because Cfront allows it.
5578 NIHCL uses it. It is not valid ISO C++ however. */
5579 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5581 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5582 type = build_pointer_type (TREE_TYPE (type));
5586 error ("ISO C++ forbids casting to an array type %qT", type);
5587 return error_mark_node;
5591 if (TREE_CODE (type) == FUNCTION_TYPE
5592 || TREE_CODE (type) == METHOD_TYPE)
5594 error ("invalid cast to function type %qT", type);
5595 return error_mark_node;
5598 /* A C-style cast can be a const_cast. */
5599 result = build_const_cast_1 (type, value, /*complain=*/false,
5604 /* Or a static cast. */
5605 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5607 /* Or a reinterpret_cast. */
5609 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5611 /* The static_cast or reinterpret_cast may be followed by a
5614 /* A valid cast may result in errors if, for example, a
5615 conversion to am ambiguous base class is required. */
5616 && !error_operand_p (result))
5620 /* Non-class rvalues always have cv-unqualified type. */
5621 if (!CLASS_TYPE_P (type))
5622 type = TYPE_MAIN_VARIANT (type);
5623 result_type = TREE_TYPE (result);
5624 if (!CLASS_TYPE_P (result_type))
5625 result_type = TYPE_MAIN_VARIANT (result_type);
5626 /* If the type of RESULT does not match TYPE, perform a
5627 const_cast to make it match. If the static_cast or
5628 reinterpret_cast succeeded, we will differ by at most
5629 cv-qualification, so the follow-on const_cast is guaranteed
5631 if (!same_type_p (non_reference (type), non_reference (result_type)))
5633 result = build_const_cast_1 (type, result, false, &valid_p);
5634 gcc_assert (valid_p);
5639 return error_mark_node;
5642 /* Build an assignment expression of lvalue LHS from value RHS.
5643 MODIFYCODE is the code for a binary operator that we use
5644 to combine the old value of LHS with RHS to get the new value.
5645 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5647 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5650 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5654 tree lhstype = TREE_TYPE (lhs);
5655 tree olhstype = lhstype;
5656 tree olhs = NULL_TREE;
5657 bool plain_assign = (modifycode == NOP_EXPR);
5659 /* Avoid duplicate error messages from operands that had errors. */
5660 if (error_operand_p (lhs) || error_operand_p (rhs))
5661 return error_mark_node;
5663 /* Handle control structure constructs used as "lvalues". */
5664 switch (TREE_CODE (lhs))
5666 /* Handle --foo = 5; as these are valid constructs in C++. */
5667 case PREDECREMENT_EXPR:
5668 case PREINCREMENT_EXPR:
5669 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5670 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5671 stabilize_reference (TREE_OPERAND (lhs, 0)),
5672 TREE_OPERAND (lhs, 1));
5673 return build2 (COMPOUND_EXPR, lhstype,
5675 build_modify_expr (TREE_OPERAND (lhs, 0),
5678 /* Handle (a, b) used as an "lvalue". */
5680 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5682 if (newrhs == error_mark_node)
5683 return error_mark_node;
5684 return build2 (COMPOUND_EXPR, lhstype,
5685 TREE_OPERAND (lhs, 0), newrhs);
5688 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5689 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5690 stabilize_reference (TREE_OPERAND (lhs, 0)),
5691 TREE_OPERAND (lhs, 1));
5692 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5693 if (newrhs == error_mark_node)
5694 return error_mark_node;
5695 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5699 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5700 when neither operand has side-effects. */
5701 if (!lvalue_or_else (lhs, lv_assign))
5702 return error_mark_node;
5704 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5705 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5707 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5708 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5710 TREE_OPERAND (lhs, 0),
5711 TREE_OPERAND (lhs, 1)),
5712 TREE_OPERAND (lhs, 0),
5713 TREE_OPERAND (lhs, 1));
5716 /* Handle (a ? b : c) used as an "lvalue". */
5719 /* Produce (a ? (b = rhs) : (c = rhs))
5720 except that the RHS goes through a save-expr
5721 so the code to compute it is only emitted once. */
5723 tree preeval = NULL_TREE;
5725 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5727 error ("void value not ignored as it ought to be");
5728 return error_mark_node;
5731 rhs = stabilize_expr (rhs, &preeval);
5733 /* Check this here to avoid odd errors when trying to convert
5734 a throw to the type of the COND_EXPR. */
5735 if (!lvalue_or_else (lhs, lv_assign))
5736 return error_mark_node;
5738 cond = build_conditional_expr
5739 (TREE_OPERAND (lhs, 0),
5740 build_modify_expr (TREE_OPERAND (lhs, 1),
5742 build_modify_expr (TREE_OPERAND (lhs, 2),
5745 if (cond == error_mark_node)
5747 /* Make sure the code to compute the rhs comes out
5748 before the split. */
5750 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5758 if (modifycode == INIT_EXPR)
5760 if (TREE_CODE (rhs) == CONSTRUCTOR)
5762 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5763 /* Call convert to generate an error; see PR 11063. */
5764 rhs = convert (lhstype, rhs);
5765 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5766 TREE_SIDE_EFFECTS (result) = 1;
5769 else if (! IS_AGGR_TYPE (lhstype))
5770 /* Do the default thing. */;
5773 result = build_special_member_call (lhs, complete_ctor_identifier,
5774 build_tree_list (NULL_TREE, rhs),
5775 lhstype, LOOKUP_NORMAL);
5776 if (result == NULL_TREE)
5777 return error_mark_node;
5783 lhs = require_complete_type (lhs);
5784 if (lhs == error_mark_node)
5785 return error_mark_node;
5787 if (modifycode == NOP_EXPR)
5789 /* `operator=' is not an inheritable operator. */
5790 if (! IS_AGGR_TYPE (lhstype))
5791 /* Do the default thing. */;
5794 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5795 lhs, rhs, make_node (NOP_EXPR),
5796 /*overloaded_p=*/NULL);
5797 if (result == NULL_TREE)
5798 return error_mark_node;
5805 /* A binary op has been requested. Combine the old LHS
5806 value with the RHS producing the value we should actually
5807 store into the LHS. */
5809 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5810 lhs = stabilize_reference (lhs);
5811 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5812 if (newrhs == error_mark_node)
5814 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5815 TREE_TYPE (lhs), TREE_TYPE (rhs));
5816 return error_mark_node;
5819 /* Now it looks like a plain assignment. */
5820 modifycode = NOP_EXPR;
5822 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5823 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5826 /* The left-hand side must be an lvalue. */
5827 if (!lvalue_or_else (lhs, lv_assign))
5828 return error_mark_node;
5830 /* Warn about modifying something that is `const'. Don't warn if
5831 this is initialization. */
5832 if (modifycode != INIT_EXPR
5833 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5834 /* Functions are not modifiable, even though they are
5836 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5837 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5838 /* If it's an aggregate and any field is const, then it is
5839 effectively const. */
5840 || (CLASS_TYPE_P (lhstype)
5841 && C_TYPE_FIELDS_READONLY (lhstype))))
5842 readonly_error (lhs, "assignment");
5844 /* If storing into a structure or union member, it has probably been
5845 given type `int'. Compute the type that would go with the actual
5846 amount of storage the member occupies. */
5848 if (TREE_CODE (lhs) == COMPONENT_REF
5849 && (TREE_CODE (lhstype) == INTEGER_TYPE
5850 || TREE_CODE (lhstype) == REAL_TYPE
5851 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5853 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5855 /* If storing in a field that is in actuality a short or narrower
5856 than one, we must store in the field in its actual type. */
5858 if (lhstype != TREE_TYPE (lhs))
5860 /* Avoid warnings converting integral types back into enums for
5862 if (TREE_CODE (lhstype) == INTEGER_TYPE
5863 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5865 if (TREE_SIDE_EFFECTS (lhs))
5866 lhs = stabilize_reference (lhs);
5869 lhs = copy_node (lhs);
5870 TREE_TYPE (lhs) = lhstype;
5874 /* Convert new value to destination type. */
5876 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5880 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5881 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5883 error ("incompatible types in assignment of %qT to %qT",
5884 TREE_TYPE (rhs), lhstype);
5885 return error_mark_node;
5888 /* Allow array assignment in compiler-generated code. */
5889 if (! DECL_ARTIFICIAL (current_function_decl))
5891 /* This routine is used for both initialization and assignment.
5892 Make sure the diagnostic message differentiates the context. */
5893 if (modifycode == INIT_EXPR)
5894 error ("array used as initializer");
5896 error ("invalid array assignment");
5897 return error_mark_node;
5900 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5901 ? 1 + (modifycode != INIT_EXPR): 0;
5902 return build_vec_init (lhs, NULL_TREE, newrhs,
5903 /*explicit_default_init_p=*/false,
5907 if (modifycode == INIT_EXPR)
5908 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5909 "initialization", NULL_TREE, 0);
5912 /* Avoid warnings on enum bit fields. */
5913 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5914 && TREE_CODE (lhstype) == INTEGER_TYPE)
5916 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5918 newrhs = convert_force (lhstype, newrhs, 0);
5921 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5923 if (TREE_CODE (newrhs) == CALL_EXPR
5924 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5925 newrhs = build_cplus_new (lhstype, newrhs);
5927 /* Can't initialize directly from a TARGET_EXPR, since that would
5928 cause the lhs to be constructed twice, and possibly result in
5929 accidental self-initialization. So we force the TARGET_EXPR to be
5930 expanded without a target. */
5931 if (TREE_CODE (newrhs) == TARGET_EXPR)
5932 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5933 TREE_OPERAND (newrhs, 0));
5936 if (newrhs == error_mark_node)
5937 return error_mark_node;
5939 if (c_dialect_objc () && flag_objc_gc)
5941 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5947 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5948 lhstype, lhs, newrhs);
5950 TREE_SIDE_EFFECTS (result) = 1;
5952 TREE_NO_WARNING (result) = 1;
5954 /* If we got the LHS in a different type for storing in,
5955 convert the result back to the nominal type of LHS
5956 so that the value we return always has the same type
5957 as the LHS argument. */
5959 if (olhstype == TREE_TYPE (result))
5963 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5964 TREE_NO_WARNING (result) = 1;
5967 return convert_for_assignment (olhstype, result, "assignment",
5972 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5974 if (processing_template_decl)
5975 return build_min_nt (MODOP_EXPR, lhs,
5976 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5978 if (modifycode != NOP_EXPR)
5980 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5981 make_node (modifycode),
5982 /*overloaded_p=*/NULL);
5985 TREE_NO_WARNING (rval) = 1;
5989 return build_modify_expr (lhs, modifycode, rhs);
5992 /* Helper function for get_delta_difference which assumes FROM is a base
5993 class of TO. Returns a delta for the conversion of pointer-to-member
5994 of FROM to pointer-to-member of TO. If the conversion is invalid,
5995 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
5996 If C_CAST_P is true, this conversion is taking place as part of a C-style
6000 get_delta_difference_1 (tree from, tree to, bool c_cast_p)
6005 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
6006 if (kind == bk_inaccessible || kind == bk_ambig)
6008 error (" in pointer to member function conversion");
6009 return size_zero_node;
6013 if (kind != bk_via_virtual)
6014 return BINFO_OFFSET (binfo);
6016 /* FROM is a virtual base class of TO. Issue an error or warning
6017 depending on whether or not this is a reinterpret cast. */
6019 error ("pointer to member conversion via virtual base %qT",
6020 BINFO_TYPE (binfo_from_vbase (binfo)));
6022 return size_zero_node;
6029 /* Get difference in deltas for different pointer to member function
6030 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6031 the conversion is invalid, the constant is zero. If
6032 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6033 If C_CAST_P is true this conversion is taking place as part of a
6036 Note that the naming of FROM and TO is kind of backwards; the return
6037 value is what we add to a TO in order to get a FROM. They are named
6038 this way because we call this function to find out how to convert from
6039 a pointer to member of FROM to a pointer to member of TO. */
6042 get_delta_difference (tree from, tree to,
6043 bool allow_inverse_p,
6048 if (same_type_ignoring_top_level_qualifiers_p (from, to))
6049 /* Pointer to member of incomplete class is permitted*/
6050 result = size_zero_node;
6052 result = get_delta_difference_1 (from, to, c_cast_p);
6056 if (!allow_inverse_p)
6058 error_not_base_type (from, to);
6059 error (" in pointer to member conversion");
6060 result = size_zero_node;
6064 result = get_delta_difference_1 (to, from, c_cast_p);
6067 result = size_diffop (size_zero_node, result);
6070 error_not_base_type (from, to);
6071 error (" in pointer to member conversion");
6072 result = size_zero_node;
6077 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6081 /* Return a constructor for the pointer-to-member-function TYPE using
6082 the other components as specified. */
6085 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6090 VEC(constructor_elt, gc) *v;
6092 /* Pull the FIELD_DECLs out of the type. */
6093 pfn_field = TYPE_FIELDS (type);
6094 delta_field = TREE_CHAIN (pfn_field);
6096 /* Make sure DELTA has the type we want. */
6097 delta = convert_and_check (delta_type_node, delta);
6099 /* Convert to the correct target type if necessary. */
6100 pfn = fold_convert (TREE_TYPE (pfn_field), pfn);
6102 /* Finish creating the initializer. */
6103 v = VEC_alloc(constructor_elt, gc, 2);
6104 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6105 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6106 u = build_constructor (type, v);
6107 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6108 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6109 TREE_STATIC (u) = (TREE_CONSTANT (u)
6110 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6112 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6117 /* Build a constructor for a pointer to member function. It can be
6118 used to initialize global variables, local variable, or used
6119 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6122 If FORCE is nonzero, then force this conversion, even if
6123 we would rather not do it. Usually set when using an explicit
6124 cast. A C-style cast is being processed iff C_CAST_P is true.
6126 Return error_mark_node, if something goes wrong. */
6129 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6135 if (error_operand_p (pfn))
6136 return error_mark_node;
6138 pfn_type = TREE_TYPE (pfn);
6139 to_type = build_ptrmemfunc_type (type);
6141 /* Handle multiple conversions of pointer to member functions. */
6142 if (TYPE_PTRMEMFUNC_P (pfn_type))
6144 tree delta = NULL_TREE;
6145 tree npfn = NULL_TREE;
6149 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6150 error ("invalid conversion to type %qT from type %qT",
6153 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6154 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6158 /* We don't have to do any conversion to convert a
6159 pointer-to-member to its own type. But, we don't want to
6160 just return a PTRMEM_CST if there's an explicit cast; that
6161 cast should make the expression an invalid template argument. */
6162 if (TREE_CODE (pfn) != PTRMEM_CST)
6164 if (same_type_p (to_type, pfn_type))
6166 else if (integer_zerop (n))
6167 return build_reinterpret_cast (to_type, pfn);
6170 if (TREE_SIDE_EFFECTS (pfn))
6171 pfn = save_expr (pfn);
6173 /* Obtain the function pointer and the current DELTA. */
6174 if (TREE_CODE (pfn) == PTRMEM_CST)
6175 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6178 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6179 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6182 /* Just adjust the DELTA field. */
6183 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6184 (TREE_TYPE (delta), ptrdiff_type_node));
6185 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6186 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6187 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6188 return build_ptrmemfunc1 (to_type, delta, npfn);
6191 /* Handle null pointer to member function conversions. */
6192 if (integer_zerop (pfn))
6194 pfn = build_c_cast (type, integer_zero_node);
6195 return build_ptrmemfunc1 (to_type,
6200 if (type_unknown_p (pfn))
6201 return instantiate_type (type, pfn, tf_warning_or_error);
6203 fn = TREE_OPERAND (pfn, 0);
6204 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6205 /* In a template, we will have preserved the
6207 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6208 return make_ptrmem_cst (to_type, fn);
6211 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6214 ??? There is no consistency as to the types returned for the above
6215 values. Some code acts as if it were a sizetype and some as if it were
6216 integer_type_node. */
6219 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6221 tree type = TREE_TYPE (cst);
6222 tree fn = PTRMEM_CST_MEMBER (cst);
6223 tree ptr_class, fn_class;
6225 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6227 /* The class that the function belongs to. */
6228 fn_class = DECL_CONTEXT (fn);
6230 /* The class that we're creating a pointer to member of. */
6231 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6233 /* First, calculate the adjustment to the function's class. */
6234 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6237 if (!DECL_VIRTUAL_P (fn))
6238 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6241 /* If we're dealing with a virtual function, we have to adjust 'this'
6242 again, to point to the base which provides the vtable entry for
6243 fn; the call will do the opposite adjustment. */
6244 tree orig_class = DECL_CONTEXT (fn);
6245 tree binfo = binfo_or_else (orig_class, fn_class);
6246 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6247 *delta, BINFO_OFFSET (binfo));
6248 *delta = fold_if_not_in_template (*delta);
6250 /* We set PFN to the vtable offset at which the function can be
6251 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6252 case delta is shifted left, and then incremented). */
6253 *pfn = DECL_VINDEX (fn);
6254 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6255 TYPE_SIZE_UNIT (vtable_entry_type));
6256 *pfn = fold_if_not_in_template (*pfn);
6258 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6260 case ptrmemfunc_vbit_in_pfn:
6261 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6263 *pfn = fold_if_not_in_template (*pfn);
6266 case ptrmemfunc_vbit_in_delta:
6267 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6268 *delta, integer_one_node);
6269 *delta = fold_if_not_in_template (*delta);
6270 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6271 *delta, integer_one_node);
6272 *delta = fold_if_not_in_template (*delta);
6279 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6280 *pfn = fold_if_not_in_template (*pfn);
6284 /* Return an expression for PFN from the pointer-to-member function
6288 pfn_from_ptrmemfunc (tree t)
6290 if (TREE_CODE (t) == PTRMEM_CST)
6295 expand_ptrmemfunc_cst (t, &delta, &pfn);
6300 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6303 /* Return an expression for DELTA from the pointer-to-member function
6307 delta_from_ptrmemfunc (tree t)
6309 if (TREE_CODE (t) == PTRMEM_CST)
6314 expand_ptrmemfunc_cst (t, &delta, &pfn);
6319 return build_ptrmemfunc_access_expr (t, delta_identifier);
6322 /* Convert value RHS to type TYPE as preparation for an assignment to
6323 an lvalue of type TYPE. ERRTYPE is a string to use in error
6324 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6325 are doing the conversion in order to pass the PARMNUMth argument of
6329 convert_for_assignment (tree type, tree rhs,
6330 const char *errtype, tree fndecl, int parmnum)
6333 enum tree_code coder;
6335 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6336 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6337 rhs = TREE_OPERAND (rhs, 0);
6339 rhstype = TREE_TYPE (rhs);
6340 coder = TREE_CODE (rhstype);
6342 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6343 && vector_types_convertible_p (type, rhstype, true))
6344 return convert (type, rhs);
6346 if (rhs == error_mark_node || rhstype == error_mark_node)
6347 return error_mark_node;
6348 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6349 return error_mark_node;
6351 /* The RHS of an assignment cannot have void type. */
6352 if (coder == VOID_TYPE)
6354 error ("void value not ignored as it ought to be");
6355 return error_mark_node;
6358 /* Simplify the RHS if possible. */
6359 if (TREE_CODE (rhs) == CONST_DECL)
6360 rhs = DECL_INITIAL (rhs);
6362 if (c_dialect_objc ())
6365 tree rname = fndecl;
6367 if (!strcmp (errtype, "assignment"))
6369 else if (!strcmp (errtype, "initialization"))
6373 tree selector = objc_message_selector ();
6377 if (selector && parmno > 1)
6384 if (objc_compare_types (type, rhstype, parmno, rname))
6385 return convert (type, rhs);
6390 The expression is implicitly converted (clause _conv_) to the
6391 cv-unqualified type of the left operand.
6393 We allow bad conversions here because by the time we get to this point
6394 we are committed to doing the conversion. If we end up doing a bad
6395 conversion, convert_like will complain. */
6396 if (!can_convert_arg_bad (type, rhstype, rhs))
6398 /* When -Wno-pmf-conversions is use, we just silently allow
6399 conversions from pointers-to-members to plain pointers. If
6400 the conversion doesn't work, cp_convert will complain. */
6402 && TYPE_PTR_P (type)
6403 && TYPE_PTRMEMFUNC_P (rhstype))
6404 rhs = cp_convert (strip_top_quals (type), rhs);
6407 /* If the right-hand side has unknown type, then it is an
6408 overloaded function. Call instantiate_type to get error
6410 if (rhstype == unknown_type_node)
6411 instantiate_type (type, rhs, tf_warning_or_error);
6413 error ("cannot convert %qT to %qT for argument %qP to %qD",
6414 rhstype, type, parmnum, fndecl);
6416 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6417 return error_mark_node;
6420 if (warn_missing_format_attribute)
6422 const enum tree_code codel = TREE_CODE (type);
6423 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6425 && check_missing_format_attribute (type, rhstype))
6426 warning (OPT_Wmissing_format_attribute,
6427 "%s might be a candidate for a format attribute",
6431 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6433 if (warn_parentheses
6434 && type == boolean_type_node
6435 && TREE_CODE (rhs) == MODIFY_EXPR
6436 && !TREE_NO_WARNING (rhs)
6437 && TREE_TYPE (rhs) != boolean_type_node)
6439 warning (OPT_Wparentheses,
6440 "suggest parentheses around assignment used as truth value");
6441 TREE_NO_WARNING (rhs) = 1;
6444 return perform_implicit_conversion (strip_top_quals (type), rhs);
6447 /* Convert RHS to be of type TYPE.
6448 If EXP is nonzero, it is the target of the initialization.
6449 ERRTYPE is a string to use in error messages.
6451 Two major differences between the behavior of
6452 `convert_for_assignment' and `convert_for_initialization'
6453 are that references are bashed in the former, while
6454 copied in the latter, and aggregates are assigned in
6455 the former (operator=) while initialized in the
6458 If using constructor make sure no conversion operator exists, if one does
6459 exist, an ambiguity exists.
6461 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6464 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6465 const char *errtype, tree fndecl, int parmnum)
6467 enum tree_code codel = TREE_CODE (type);
6469 enum tree_code coder;
6471 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6472 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6473 if (TREE_CODE (rhs) == NOP_EXPR
6474 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6475 && codel != REFERENCE_TYPE)
6476 rhs = TREE_OPERAND (rhs, 0);
6478 if (type == error_mark_node
6479 || rhs == error_mark_node
6480 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6481 return error_mark_node;
6483 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6484 && TREE_CODE (type) != ARRAY_TYPE
6485 && (TREE_CODE (type) != REFERENCE_TYPE
6486 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6487 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6488 && (TREE_CODE (type) != REFERENCE_TYPE
6489 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6490 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6491 rhs = decay_conversion (rhs);
6493 rhstype = TREE_TYPE (rhs);
6494 coder = TREE_CODE (rhstype);
6496 if (coder == ERROR_MARK)
6497 return error_mark_node;
6499 /* We accept references to incomplete types, so we can
6500 return here before checking if RHS is of complete type. */
6502 if (codel == REFERENCE_TYPE)
6504 /* This should eventually happen in convert_arguments. */
6505 int savew = 0, savee = 0;
6508 savew = warningcount, savee = errorcount;
6509 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6513 if (warningcount > savew)
6514 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6515 else if (errorcount > savee)
6516 error ("in passing argument %P of %q+D", parmnum, fndecl);
6522 exp = require_complete_type (exp);
6523 if (exp == error_mark_node)
6524 return error_mark_node;
6526 rhstype = non_reference (rhstype);
6528 type = complete_type (type);
6530 if (IS_AGGR_TYPE (type))
6531 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6533 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6536 /* If RETVAL is the address of, or a reference to, a local variable or
6537 temporary give an appropriate warning. */
6540 maybe_warn_about_returning_address_of_local (tree retval)
6542 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6543 tree whats_returned = retval;
6547 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6548 whats_returned = TREE_OPERAND (whats_returned, 1);
6549 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6550 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6551 || TREE_CODE (whats_returned) == NOP_EXPR)
6552 whats_returned = TREE_OPERAND (whats_returned, 0);
6557 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6559 whats_returned = TREE_OPERAND (whats_returned, 0);
6561 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6563 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6564 || TREE_CODE (whats_returned) == TARGET_EXPR)
6566 warning (0, "returning reference to temporary");
6569 if (TREE_CODE (whats_returned) == VAR_DECL
6570 && DECL_NAME (whats_returned)
6571 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6573 warning (0, "reference to non-lvalue returned");
6578 while (TREE_CODE (whats_returned) == COMPONENT_REF
6579 || TREE_CODE (whats_returned) == ARRAY_REF)
6580 whats_returned = TREE_OPERAND (whats_returned, 0);
6582 if (DECL_P (whats_returned)
6583 && DECL_NAME (whats_returned)
6584 && DECL_FUNCTION_SCOPE_P (whats_returned)
6585 && !(TREE_STATIC (whats_returned)
6586 || TREE_PUBLIC (whats_returned)))
6588 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6589 warning (0, "reference to local variable %q+D returned",
6592 warning (0, "address of local variable %q+D returned",
6598 /* Check that returning RETVAL from the current function is valid.
6599 Return an expression explicitly showing all conversions required to
6600 change RETVAL into the function return type, and to assign it to
6601 the DECL_RESULT for the function. Set *NO_WARNING to true if
6602 code reaches end of non-void function warning shouldn't be issued
6603 on this RETURN_EXPR. */
6606 check_return_expr (tree retval, bool *no_warning)
6609 /* The type actually returned by the function, after any
6612 int fn_returns_value_p;
6613 bool named_return_value_okay_p;
6615 *no_warning = false;
6617 /* A `volatile' function is one that isn't supposed to return, ever.
6618 (This is a G++ extension, used to get better code for functions
6619 that call the `volatile' function.) */
6620 if (TREE_THIS_VOLATILE (current_function_decl))
6621 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6623 /* Check for various simple errors. */
6624 if (DECL_DESTRUCTOR_P (current_function_decl))
6627 error ("returning a value from a destructor");
6630 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6632 if (in_function_try_handler)
6633 /* If a return statement appears in a handler of the
6634 function-try-block of a constructor, the program is ill-formed. */
6635 error ("cannot return from a handler of a function-try-block of a constructor");
6637 /* You can't return a value from a constructor. */
6638 error ("returning a value from a constructor");
6642 if (processing_template_decl)
6644 current_function_returns_value = 1;
6645 check_for_bare_parameter_packs (&retval);
6649 /* When no explicit return-value is given in a function with a named
6650 return value, the named return value is used. */
6651 result = DECL_RESULT (current_function_decl);
6652 valtype = TREE_TYPE (result);
6653 gcc_assert (valtype != NULL_TREE);
6654 fn_returns_value_p = !VOID_TYPE_P (valtype);
6655 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6658 /* Check for a return statement with no return value in a function
6659 that's supposed to return a value. */
6660 if (!retval && fn_returns_value_p)
6662 pedwarn ("return-statement with no value, in function returning %qT",
6664 /* Clear this, so finish_function won't say that we reach the
6665 end of a non-void function (which we don't, we gave a
6667 current_function_returns_null = 0;
6668 /* And signal caller that TREE_NO_WARNING should be set on the
6669 RETURN_EXPR to avoid control reaches end of non-void function
6670 warnings in tree-cfg.c. */
6673 /* Check for a return statement with a value in a function that
6674 isn't supposed to return a value. */
6675 else if (retval && !fn_returns_value_p)
6677 if (VOID_TYPE_P (TREE_TYPE (retval)))
6678 /* You can return a `void' value from a function of `void'
6679 type. In that case, we have to evaluate the expression for
6680 its side-effects. */
6681 finish_expr_stmt (retval);
6683 pedwarn ("return-statement with a value, in function "
6684 "returning 'void'");
6686 current_function_returns_null = 1;
6688 /* There's really no value to return, after all. */
6692 /* Remember that this function can sometimes return without a
6694 current_function_returns_null = 1;
6696 /* Remember that this function did return a value. */
6697 current_function_returns_value = 1;
6699 /* Check for erroneous operands -- but after giving ourselves a
6700 chance to provide an error about returning a value from a void
6702 if (error_operand_p (retval))
6704 current_function_return_value = error_mark_node;
6705 return error_mark_node;
6708 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6709 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6710 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6711 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6713 && retval && null_ptr_cst_p (retval))
6714 warning (0, "%<operator new%> must not return NULL unless it is "
6715 "declared %<throw()%> (or -fcheck-new is in effect)");
6717 /* Effective C++ rule 15. See also start_function. */
6719 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6723 /* The function return type must be a reference to the current
6725 if (TREE_CODE (valtype) == REFERENCE_TYPE
6726 && same_type_ignoring_top_level_qualifiers_p
6727 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6729 /* Returning '*this' is obviously OK. */
6730 if (retval == current_class_ref)
6732 /* If we are calling a function whose return type is the same of
6733 the current class reference, it is ok. */
6734 else if (TREE_CODE (retval) == INDIRECT_REF
6735 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6740 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6743 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6745 [...] For a function with a class return type, if the expression
6746 in the return statement is the name of a local object, and the cv-
6747 unqualified type of the local object is the same as the function
6748 return type, an implementation is permitted to omit creating the tem-
6749 porary object to hold the function return value [...]
6751 So, if this is a value-returning function that always returns the same
6752 local variable, remember it.
6754 It might be nice to be more flexible, and choose the first suitable
6755 variable even if the function sometimes returns something else, but
6756 then we run the risk of clobbering the variable we chose if the other
6757 returned expression uses the chosen variable somehow. And people expect
6758 this restriction, anyway. (jason 2000-11-19)
6760 See finish_function and finalize_nrv for the rest of this optimization. */
6762 named_return_value_okay_p =
6763 (retval != NULL_TREE
6764 /* Must be a local, automatic variable. */
6765 && TREE_CODE (retval) == VAR_DECL
6766 && DECL_CONTEXT (retval) == current_function_decl
6767 && ! TREE_STATIC (retval)
6768 && ! DECL_ANON_UNION_VAR_P (retval)
6769 && (DECL_ALIGN (retval)
6770 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6771 /* The cv-unqualified type of the returned value must be the
6772 same as the cv-unqualified return type of the
6774 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
6776 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
6777 /* And the returned value must be non-volatile. */
6778 && ! TYPE_VOLATILE (TREE_TYPE (retval)));
6780 if (fn_returns_value_p && flag_elide_constructors)
6782 if (named_return_value_okay_p
6783 && (current_function_return_value == NULL_TREE
6784 || current_function_return_value == retval))
6785 current_function_return_value = retval;
6787 current_function_return_value = error_mark_node;
6790 /* We don't need to do any conversions when there's nothing being
6795 /* Do any required conversions. */
6796 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6797 /* No conversions are required. */
6801 /* The type the function is declared to return. */
6802 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6803 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
6805 /* The functype's return type will have been set to void, if it
6806 was an incomplete type. Just treat this as 'return;' */
6807 if (VOID_TYPE_P (functype))
6808 return error_mark_node;
6810 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
6811 treated as an rvalue for the purposes of overload resolution to
6812 favor move constructors over copy constructors. */
6813 if ((cxx_dialect != cxx98)
6814 && named_return_value_okay_p
6815 /* The variable must not have the `volatile' qualifier. */
6816 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
6817 /* The return type must be a class type. */
6818 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
6819 flags = flags | LOOKUP_PREFER_RVALUE;
6821 /* First convert the value to the function's return type, then
6822 to the type of return value's location to handle the
6823 case that functype is smaller than the valtype. */
6824 retval = convert_for_initialization
6825 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0);
6826 retval = convert (valtype, retval);
6828 /* If the conversion failed, treat this just like `return;'. */
6829 if (retval == error_mark_node)
6831 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6832 else if (! current_function_returns_struct
6833 && TREE_CODE (retval) == TARGET_EXPR
6834 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6835 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6836 TREE_OPERAND (retval, 0));
6838 maybe_warn_about_returning_address_of_local (retval);
6841 /* Actually copy the value returned into the appropriate location. */
6842 if (retval && retval != result)
6843 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6849 /* Returns nonzero if the pointer-type FROM can be converted to the
6850 pointer-type TO via a qualification conversion. If CONSTP is -1,
6851 then we return nonzero if the pointers are similar, and the
6852 cv-qualification signature of FROM is a proper subset of that of TO.
6854 If CONSTP is positive, then all outer pointers have been
6858 comp_ptr_ttypes_real (tree to, tree from, int constp)
6860 bool to_more_cv_qualified = false;
6862 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6864 if (TREE_CODE (to) != TREE_CODE (from))
6867 if (TREE_CODE (from) == OFFSET_TYPE
6868 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6869 TYPE_OFFSET_BASETYPE (to)))
6872 /* Const and volatile mean something different for function types,
6873 so the usual checks are not appropriate. */
6874 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6876 /* In Objective-C++, some types may have been 'volatilized' by
6877 the compiler for EH; when comparing them here, the volatile
6878 qualification must be ignored. */
6879 bool objc_quals_match = objc_type_quals_match (to, from);
6881 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6884 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6888 to_more_cv_qualified = true;
6892 constp &= TYPE_READONLY (to);
6895 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6896 return ((constp >= 0 || to_more_cv_qualified)
6897 && same_type_ignoring_top_level_qualifiers_p (to, from));
6901 /* When comparing, say, char ** to char const **, this function takes
6902 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6903 types to this function. */
6906 comp_ptr_ttypes (tree to, tree from)
6908 return comp_ptr_ttypes_real (to, from, 1);
6911 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6912 type or inheritance-related types, regardless of cv-quals. */
6915 ptr_reasonably_similar (const_tree to, const_tree from)
6917 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6919 /* Any target type is similar enough to void. */
6920 if (TREE_CODE (to) == VOID_TYPE
6921 || TREE_CODE (from) == VOID_TYPE)
6924 if (TREE_CODE (to) != TREE_CODE (from))
6927 if (TREE_CODE (from) == OFFSET_TYPE
6928 && comptypes (TYPE_OFFSET_BASETYPE (to),
6929 TYPE_OFFSET_BASETYPE (from),
6930 COMPARE_BASE | COMPARE_DERIVED))
6933 if (TREE_CODE (to) == VECTOR_TYPE
6934 && vector_types_convertible_p (to, from, false))
6937 if (TREE_CODE (to) == INTEGER_TYPE
6938 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6941 if (TREE_CODE (to) == FUNCTION_TYPE)
6944 if (TREE_CODE (to) != POINTER_TYPE)
6946 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6947 COMPARE_BASE | COMPARE_DERIVED);
6951 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6952 pointer-to-member types) are the same, ignoring cv-qualification at
6956 comp_ptr_ttypes_const (tree to, tree from)
6958 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6960 if (TREE_CODE (to) != TREE_CODE (from))
6963 if (TREE_CODE (from) == OFFSET_TYPE
6964 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6965 TYPE_OFFSET_BASETYPE (to)))
6968 if (TREE_CODE (to) != POINTER_TYPE)
6969 return same_type_ignoring_top_level_qualifiers_p (to, from);
6973 /* Returns the type qualifiers for this type, including the qualifiers on the
6974 elements for an array type. */
6977 cp_type_quals (const_tree type)
6979 /* This CONST_CAST is okay because strip_array_types returns it's
6980 argument unmodified and we assign it to a const_tree. */
6981 type = strip_array_types (CONST_CAST_TREE(type));
6982 if (type == error_mark_node)
6983 return TYPE_UNQUALIFIED;
6984 return TYPE_QUALS (type);
6987 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6991 cp_type_readonly (const_tree type)
6993 /* This CONST_CAST is okay because strip_array_types returns it's
6994 argument unmodified and we assign it to a const_tree. */
6995 type = strip_array_types (CONST_CAST_TREE(type));
6996 return TYPE_READONLY (type);
6999 /* Returns nonzero if the TYPE contains a mutable member. */
7002 cp_has_mutable_p (const_tree type)
7004 /* This CONST_CAST is okay because strip_array_types returns it's
7005 argument unmodified and we assign it to a const_tree. */
7006 type = strip_array_types (CONST_CAST_TREE(type));
7008 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
7011 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
7012 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
7013 approximation. In particular, consider:
7016 struct S { int i; };
7017 const S s = { f(); }
7019 Here, we will make "s" as TREE_READONLY (because it is declared
7020 "const") -- only to reverse ourselves upon seeing that the
7021 initializer is non-constant. */
7024 cp_apply_type_quals_to_decl (int type_quals, tree decl)
7026 tree type = TREE_TYPE (decl);
7028 if (type == error_mark_node)
7031 if (TREE_CODE (type) == FUNCTION_TYPE
7032 && type_quals != TYPE_UNQUALIFIED)
7034 /* This was an error in C++98 (cv-qualifiers cannot be added to
7035 a function type), but DR 295 makes the code well-formed by
7036 dropping the extra qualifiers. */
7039 tree bad_type = build_qualified_type (type, type_quals);
7040 pedwarn ("ignoring %qV qualifiers added to function type %qT",
7044 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
7048 /* Avoid setting TREE_READONLY incorrectly. */
7049 if (/* If the object has a constructor, the constructor may modify
7051 TYPE_NEEDS_CONSTRUCTING (type)
7052 /* If the type isn't complete, we don't know yet if it will need
7054 || !COMPLETE_TYPE_P (type)
7055 /* If the type has a mutable component, that component might be
7057 || TYPE_HAS_MUTABLE_P (type))
7058 type_quals &= ~TYPE_QUAL_CONST;
7060 c_apply_type_quals_to_decl (type_quals, decl);
7063 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7064 exemplar types such that casting T1 to T2 is casting away constness
7065 if and only if there is no implicit conversion from T1 to T2. */
7068 casts_away_constness_r (tree *t1, tree *t2)
7073 /* [expr.const.cast]
7075 For multi-level pointer to members and multi-level mixed pointers
7076 and pointers to members (conv.qual), the "member" aspect of a
7077 pointer to member level is ignored when determining if a const
7078 cv-qualifier has been cast away. */
7079 /* [expr.const.cast]
7081 For two pointer types:
7083 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7084 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7087 casting from X1 to X2 casts away constness if, for a non-pointer
7088 type T there does not exist an implicit conversion (clause
7091 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7095 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7096 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7097 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7099 *t1 = cp_build_qualified_type (void_type_node,
7100 cp_type_quals (*t1));
7101 *t2 = cp_build_qualified_type (void_type_node,
7102 cp_type_quals (*t2));
7106 quals1 = cp_type_quals (*t1);
7107 quals2 = cp_type_quals (*t2);
7109 if (TYPE_PTRMEM_P (*t1))
7110 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7112 *t1 = TREE_TYPE (*t1);
7113 if (TYPE_PTRMEM_P (*t2))
7114 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7116 *t2 = TREE_TYPE (*t2);
7118 casts_away_constness_r (t1, t2);
7119 *t1 = build_pointer_type (*t1);
7120 *t2 = build_pointer_type (*t2);
7121 *t1 = cp_build_qualified_type (*t1, quals1);
7122 *t2 = cp_build_qualified_type (*t2, quals2);
7125 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7129 casts_away_constness (tree t1, tree t2)
7131 if (TREE_CODE (t2) == REFERENCE_TYPE)
7133 /* [expr.const.cast]
7135 Casting from an lvalue of type T1 to an lvalue of type T2
7136 using a reference cast casts away constness if a cast from an
7137 rvalue of type "pointer to T1" to the type "pointer to T2"
7138 casts away constness. */
7139 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7140 return casts_away_constness (build_pointer_type (t1),
7141 build_pointer_type (TREE_TYPE (t2)));
7144 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7145 /* [expr.const.cast]
7147 Casting from an rvalue of type "pointer to data member of X
7148 of type T1" to the type "pointer to data member of Y of type
7149 T2" casts away constness if a cast from an rvalue of type
7150 "pointer to T1" to the type "pointer to T2" casts away
7152 return casts_away_constness
7153 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7154 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7156 /* Casting away constness is only something that makes sense for
7157 pointer or reference types. */
7158 if (TREE_CODE (t1) != POINTER_TYPE
7159 || TREE_CODE (t2) != POINTER_TYPE)
7162 /* Top-level qualifiers don't matter. */
7163 t1 = TYPE_MAIN_VARIANT (t1);
7164 t2 = TYPE_MAIN_VARIANT (t2);
7165 casts_away_constness_r (&t1, &t2);
7166 if (!can_convert (t2, t1))
7172 /* If T is a REFERENCE_TYPE return the type to which T refers.
7173 Otherwise, return T itself. */
7176 non_reference (tree t)
7178 if (TREE_CODE (t) == REFERENCE_TYPE)
7184 /* Return nonzero if REF is an lvalue valid for this language;
7185 otherwise, print an error message and return zero. USE says
7186 how the lvalue is being used and so selects the error message. */
7189 lvalue_or_else (const_tree ref, enum lvalue_use use)
7191 int win = lvalue_p (ref);