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))
966 /* Allow for two different type nodes which have essentially the same
967 definition. Note that we already checked for equality of the type
968 qualifiers (just above). */
970 if (TREE_CODE (t1) != ARRAY_TYPE
971 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
974 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
977 /* Compare the types. Break out if they could be the same. */
978 switch (TREE_CODE (t1))
982 /* All void and bool types are the same. */
986 case FIXED_POINT_TYPE:
988 /* With these nodes, we can't determine type equivalence by
989 looking at what is stored in the nodes themselves, because
990 two nodes might have different TYPE_MAIN_VARIANTs but still
991 represent the same type. For example, wchar_t and int could
992 have the same properties (TYPE_PRECISION, TYPE_MIN_VALUE,
993 TYPE_MAX_VALUE, etc.), but have different TYPE_MAIN_VARIANTs
994 and are distinct types. On the other hand, int and the
997 typedef int INT __attribute((may_alias));
999 have identical properties, different TYPE_MAIN_VARIANTs, but
1000 represent the same type. The canonical type system keeps
1001 track of equivalence in this case, so we fall back on it. */
1002 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1004 case TEMPLATE_TEMPLATE_PARM:
1005 case BOUND_TEMPLATE_TEMPLATE_PARM:
1006 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1007 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1008 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1009 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1011 if (!comp_template_parms
1012 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1013 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1015 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1017 /* Don't check inheritance. */
1018 strict = COMPARE_STRICT;
1023 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1024 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1025 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1026 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1029 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1031 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1037 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1038 strict & ~COMPARE_REDECLARATION))
1040 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1044 case REFERENCE_TYPE:
1045 if (TYPE_REF_IS_RVALUE (t1) != TYPE_REF_IS_RVALUE (t2))
1047 /* fall through to checks for pointer types */
1050 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1051 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1052 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1058 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1060 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1065 /* Target types must match incl. qualifiers. */
1066 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1070 case TEMPLATE_TYPE_PARM:
1071 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1072 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2)
1073 || (TEMPLATE_TYPE_PARAMETER_PACK (t1)
1074 != TEMPLATE_TYPE_PARAMETER_PACK (t2)))
1079 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1080 TYPENAME_TYPE_FULLNAME (t2)))
1082 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1086 case UNBOUND_CLASS_TEMPLATE:
1087 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1089 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1094 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1099 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1100 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1104 case TYPE_PACK_EXPANSION:
1105 return same_type_p (PACK_EXPANSION_PATTERN (t1),
1106 PACK_EXPANSION_PATTERN (t2));
1109 if (DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t1)
1110 != DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t2)
1111 || !cp_tree_equal (DECLTYPE_TYPE_EXPR (t1),
1112 DECLTYPE_TYPE_EXPR (t2)))
1120 /* If we get here, we know that from a target independent POV the
1121 types are the same. Make sure the target attributes are also
1123 return targetm.comp_type_attributes (t1, t2);
1126 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
1127 is a bitwise-or of the COMPARE_* flags. */
1130 comptypes (tree t1, tree t2, int strict)
1132 if (strict == COMPARE_STRICT)
1137 if (t1 == error_mark_node || t2 == error_mark_node)
1140 if (TYPE_STRUCTURAL_EQUALITY_P (t1) || TYPE_STRUCTURAL_EQUALITY_P (t2))
1141 /* At least one of the types requires structural equality, so
1142 perform a deep check. */
1143 return structural_comptypes (t1, t2, strict);
1145 #ifdef ENABLE_CHECKING
1146 if (USE_CANONICAL_TYPES)
1148 bool result = structural_comptypes (t1, t2, strict);
1150 if (result && TYPE_CANONICAL (t1) != TYPE_CANONICAL (t2))
1151 /* The two types are structurally equivalent, but their
1152 canonical types were different. This is a failure of the
1153 canonical type propagation code.*/
1155 ("canonical types differ for identical types %T and %T",
1157 else if (!result && TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2))
1158 /* Two types are structurally different, but the canonical
1159 types are the same. This means we were over-eager in
1160 assigning canonical types. */
1162 ("same canonical type node for different types %T and %T",
1168 if (USE_CANONICAL_TYPES)
1169 return TYPE_CANONICAL (t1) == TYPE_CANONICAL (t2);
1172 return structural_comptypes (t1, t2, strict);
1174 else if (strict == COMPARE_STRUCTURAL)
1175 return structural_comptypes (t1, t2, COMPARE_STRICT);
1177 return structural_comptypes (t1, t2, strict);
1180 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1183 at_least_as_qualified_p (const_tree type1, const_tree type2)
1185 int q1 = cp_type_quals (type1);
1186 int q2 = cp_type_quals (type2);
1188 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1189 return (q1 & q2) == q2;
1192 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1193 more cv-qualified that TYPE1, and 0 otherwise. */
1196 comp_cv_qualification (const_tree type1, const_tree type2)
1198 int q1 = cp_type_quals (type1);
1199 int q2 = cp_type_quals (type2);
1204 if ((q1 & q2) == q2)
1206 else if ((q1 & q2) == q1)
1212 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1213 subset of the cv-qualification signature of TYPE2, and the types
1214 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1217 comp_cv_qual_signature (tree type1, tree type2)
1219 if (comp_ptr_ttypes_real (type2, type1, -1))
1221 else if (comp_ptr_ttypes_real (type1, type2, -1))
1227 /* Subroutines of `comptypes'. */
1229 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1230 equivalent in the sense that functions with those parameter types
1231 can have equivalent types. The two lists must be equivalent,
1232 element by element. */
1235 compparms (const_tree parms1, const_tree parms2)
1239 /* An unspecified parmlist matches any specified parmlist
1240 whose argument types don't need default promotions. */
1242 for (t1 = parms1, t2 = parms2;
1244 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1246 /* If one parmlist is shorter than the other,
1247 they fail to match. */
1250 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1257 /* Process a sizeof or alignof expression where the operand is a
1261 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1266 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1267 if (type == error_mark_node)
1268 return error_mark_node;
1270 type = non_reference (type);
1271 if (TREE_CODE (type) == METHOD_TYPE)
1273 if (complain && (pedantic || warn_pointer_arith))
1274 pedwarn ("invalid application of %qs to a member function",
1275 operator_name_info[(int) op].name);
1276 value = size_one_node;
1279 dependent_p = dependent_type_p (type);
1281 complete_type (type);
1283 /* VLA types will have a non-constant size. In the body of an
1284 uninstantiated template, we don't need to try to compute the
1285 value, because the sizeof expression is not an integral
1286 constant expression in that case. And, if we do try to
1287 compute the value, we'll likely end up with SAVE_EXPRs, which
1288 the template substitution machinery does not expect to see. */
1289 || (processing_template_decl
1290 && COMPLETE_TYPE_P (type)
1291 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1293 value = build_min (op, size_type_node, type);
1294 TREE_READONLY (value) = 1;
1298 return c_sizeof_or_alignof_type (complete_type (type),
1303 /* Process a sizeof expression where the operand is an expression. */
1306 cxx_sizeof_expr (tree e)
1308 if (e == error_mark_node)
1309 return error_mark_node;
1311 if (processing_template_decl)
1313 e = build_min (SIZEOF_EXPR, size_type_node, e);
1314 TREE_SIDE_EFFECTS (e) = 0;
1315 TREE_READONLY (e) = 1;
1320 if (TREE_CODE (e) == COMPONENT_REF
1321 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1322 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1324 error ("invalid application of %<sizeof%> to a bit-field");
1327 else if (is_overloaded_fn (e))
1329 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1333 else if (type_unknown_p (e))
1335 cxx_incomplete_type_error (e, TREE_TYPE (e));
1341 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1344 /* Implement the __alignof keyword: Return the minimum required
1345 alignment of E, measured in bytes. For VAR_DECL's and
1346 FIELD_DECL's return DECL_ALIGN (which can be set from an
1347 "aligned" __attribute__ specification). */
1350 cxx_alignof_expr (tree e)
1354 if (e == error_mark_node)
1355 return error_mark_node;
1357 if (processing_template_decl)
1359 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1360 TREE_SIDE_EFFECTS (e) = 0;
1361 TREE_READONLY (e) = 1;
1366 if (TREE_CODE (e) == VAR_DECL)
1367 t = size_int (DECL_ALIGN_UNIT (e));
1368 else if (TREE_CODE (e) == COMPONENT_REF
1369 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1370 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1372 error ("invalid application of %<__alignof%> to a bit-field");
1375 else if (TREE_CODE (e) == COMPONENT_REF
1376 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1377 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1378 else if (is_overloaded_fn (e))
1380 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1382 if (TREE_CODE (e) == FUNCTION_DECL)
1383 t = size_int (DECL_ALIGN_UNIT (e));
1387 else if (type_unknown_p (e))
1389 cxx_incomplete_type_error (e, TREE_TYPE (e));
1393 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1395 return fold_convert (size_type_node, t);
1398 /* Process a sizeof or alignof expression E with code OP where the operand
1399 is an expression. */
1402 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1404 if (op == SIZEOF_EXPR)
1405 return cxx_sizeof_expr (e);
1407 return cxx_alignof_expr (e);
1410 /* EXPR is being used in a context that is not a function call.
1415 The expression can be used only as the left-hand operand of a
1416 member function call.
1418 [expr.mptr.operator]
1420 If the result of .* or ->* is a function, then that result can be
1421 used only as the operand for the function call operator ().
1423 by issuing an error message if appropriate. Returns true iff EXPR
1424 violates these rules. */
1427 invalid_nonstatic_memfn_p (const_tree expr)
1429 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1431 error ("invalid use of non-static member function");
1437 /* If EXP is a reference to a bitfield, and the type of EXP does not
1438 match the declared type of the bitfield, return the declared type
1439 of the bitfield. Otherwise, return NULL_TREE. */
1442 is_bitfield_expr_with_lowered_type (const_tree exp)
1444 switch (TREE_CODE (exp))
1447 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)
1448 ? TREE_OPERAND (exp, 1)
1449 : TREE_OPERAND (exp, 0)))
1451 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1454 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1458 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1464 field = TREE_OPERAND (exp, 1);
1465 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1467 if (same_type_ignoring_top_level_qualifiers_p
1468 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1470 return DECL_BIT_FIELD_TYPE (field);
1475 if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0)))
1476 == TYPE_MAIN_VARIANT (TREE_TYPE (exp)))
1477 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1485 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1486 bitfield with a lowered type, the type of EXP is returned, rather
1490 unlowered_expr_type (const_tree exp)
1494 type = is_bitfield_expr_with_lowered_type (exp);
1496 type = TREE_TYPE (exp);
1501 /* Perform the conversions in [expr] that apply when an lvalue appears
1502 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1503 function-to-pointer conversions. In addition, manifest constants
1504 are replaced by their values, and bitfield references are converted
1505 to their declared types.
1507 Although the returned value is being used as an rvalue, this
1508 function does not wrap the returned expression in a
1509 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1510 that the return value is no longer an lvalue. */
1513 decay_conversion (tree exp)
1516 enum tree_code code;
1518 type = TREE_TYPE (exp);
1519 if (type == error_mark_node)
1520 return error_mark_node;
1522 if (type_unknown_p (exp))
1524 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1525 return error_mark_node;
1528 exp = decl_constant_value (exp);
1529 if (error_operand_p (exp))
1530 return error_mark_node;
1532 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1533 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1534 code = TREE_CODE (type);
1535 if (code == VOID_TYPE)
1537 error ("void value not ignored as it ought to be");
1538 return error_mark_node;
1540 if (invalid_nonstatic_memfn_p (exp))
1541 return error_mark_node;
1542 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1543 return build_unary_op (ADDR_EXPR, exp, 0);
1544 if (code == ARRAY_TYPE)
1549 if (TREE_CODE (exp) == INDIRECT_REF)
1550 return build_nop (build_pointer_type (TREE_TYPE (type)),
1551 TREE_OPERAND (exp, 0));
1553 if (TREE_CODE (exp) == COMPOUND_EXPR)
1555 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1556 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1557 TREE_OPERAND (exp, 0), op1);
1561 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1563 error ("invalid use of non-lvalue array");
1564 return error_mark_node;
1567 ptrtype = build_pointer_type (TREE_TYPE (type));
1569 if (TREE_CODE (exp) == VAR_DECL)
1571 if (!cxx_mark_addressable (exp))
1572 return error_mark_node;
1573 adr = build_nop (ptrtype, build_address (exp));
1576 /* This way is better for a COMPONENT_REF since it can
1577 simplify the offset for a component. */
1578 adr = build_unary_op (ADDR_EXPR, exp, 1);
1579 return cp_convert (ptrtype, adr);
1582 /* If a bitfield is used in a context where integral promotion
1583 applies, then the caller is expected to have used
1584 default_conversion. That function promotes bitfields correctly
1585 before calling this function. At this point, if we have a
1586 bitfield referenced, we may assume that is not subject to
1587 promotion, and that, therefore, the type of the resulting rvalue
1588 is the declared type of the bitfield. */
1589 exp = convert_bitfield_to_declared_type (exp);
1591 /* We do not call rvalue() here because we do not want to wrap EXP
1592 in a NON_LVALUE_EXPR. */
1596 Non-class rvalues always have cv-unqualified types. */
1597 type = TREE_TYPE (exp);
1598 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1599 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1604 /* Perform prepatory conversions, as part of the "usual arithmetic
1605 conversions". In particular, as per [expr]:
1607 Whenever an lvalue expression appears as an operand of an
1608 operator that expects the rvalue for that operand, the
1609 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1610 standard conversions are applied to convert the expression to an
1613 In addition, we perform integral promotions here, as those are
1614 applied to both operands to a binary operator before determining
1615 what additional conversions should apply. */
1618 default_conversion (tree exp)
1620 /* Perform the integral promotions first so that bitfield
1621 expressions (which may promote to "int", even if the bitfield is
1622 declared "unsigned") are promoted correctly. */
1623 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1624 exp = perform_integral_promotions (exp);
1625 /* Perform the other conversions. */
1626 exp = decay_conversion (exp);
1631 /* EXPR is an expression with an integral or enumeration type.
1632 Perform the integral promotions in [conv.prom], and return the
1636 perform_integral_promotions (tree expr)
1643 If the bitfield has an enumerated type, it is treated as any
1644 other value of that type for promotion purposes. */
1645 type = is_bitfield_expr_with_lowered_type (expr);
1646 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1647 type = TREE_TYPE (expr);
1648 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1649 promoted_type = type_promotes_to (type);
1650 if (type != promoted_type)
1651 expr = cp_convert (promoted_type, expr);
1655 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1659 inline_conversion (tree exp)
1661 if (TREE_CODE (exp) == FUNCTION_DECL)
1662 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1667 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1668 decay_conversion to one. */
1671 string_conv_p (const_tree totype, const_tree exp, int warn)
1675 if (TREE_CODE (totype) != POINTER_TYPE)
1678 t = TREE_TYPE (totype);
1679 if (!same_type_p (t, char_type_node)
1680 && !same_type_p (t, wchar_type_node))
1683 if (TREE_CODE (exp) == STRING_CST)
1685 /* Make sure that we don't try to convert between char and wchar_t. */
1686 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1691 /* Is this a string constant which has decayed to 'const char *'? */
1692 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1693 if (!same_type_p (TREE_TYPE (exp), t))
1696 if (TREE_CODE (exp) != ADDR_EXPR
1697 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1701 /* This warning is not very useful, as it complains about printf. */
1703 warning (OPT_Wwrite_strings,
1704 "deprecated conversion from string constant to %qT",
1710 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1711 can, for example, use as an lvalue. This code used to be in
1712 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1713 expressions, where we're dealing with aggregates. But now it's again only
1714 called from unary_complex_lvalue. The case (in particular) that led to
1715 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1719 rationalize_conditional_expr (enum tree_code code, tree t)
1721 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1722 the first operand is always the one to be used if both operands
1723 are equal, so we know what conditional expression this used to be. */
1724 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1726 tree op0 = TREE_OPERAND (t, 0);
1727 tree op1 = TREE_OPERAND (t, 1);
1729 /* The following code is incorrect if either operand side-effects. */
1730 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1731 && !TREE_SIDE_EFFECTS (op1));
1733 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1734 ? LE_EXPR : GE_EXPR),
1735 op0, TREE_CODE (op0),
1736 op1, TREE_CODE (op1),
1737 /*overloaded_p=*/NULL),
1738 build_unary_op (code, op0, 0),
1739 build_unary_op (code, op1, 0));
1743 build_conditional_expr (TREE_OPERAND (t, 0),
1744 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1745 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1748 /* Given the TYPE of an anonymous union field inside T, return the
1749 FIELD_DECL for the field. If not found return NULL_TREE. Because
1750 anonymous unions can nest, we must also search all anonymous unions
1751 that are directly reachable. */
1754 lookup_anon_field (tree t, tree type)
1758 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1760 if (TREE_STATIC (field))
1762 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1765 /* If we find it directly, return the field. */
1766 if (DECL_NAME (field) == NULL_TREE
1767 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1772 /* Otherwise, it could be nested, search harder. */
1773 if (DECL_NAME (field) == NULL_TREE
1774 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1776 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1784 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1785 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1786 non-NULL, it indicates the path to the base used to name MEMBER.
1787 If PRESERVE_REFERENCE is true, the expression returned will have
1788 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1789 returned will have the type referred to by the reference.
1791 This function does not perform access control; that is either done
1792 earlier by the parser when the name of MEMBER is resolved to MEMBER
1793 itself, or later when overload resolution selects one of the
1794 functions indicated by MEMBER. */
1797 build_class_member_access_expr (tree object, tree member,
1798 tree access_path, bool preserve_reference)
1802 tree result = NULL_TREE;
1804 if (error_operand_p (object) || error_operand_p (member))
1805 return error_mark_node;
1807 gcc_assert (DECL_P (member) || BASELINK_P (member));
1811 The type of the first expression shall be "class object" (of a
1813 object_type = TREE_TYPE (object);
1814 if (!currently_open_class (object_type)
1815 && !complete_type_or_else (object_type, object))
1816 return error_mark_node;
1817 if (!CLASS_TYPE_P (object_type))
1819 error ("request for member %qD in %qE, which is of non-class type %qT",
1820 member, object, object_type);
1821 return error_mark_node;
1824 /* The standard does not seem to actually say that MEMBER must be a
1825 member of OBJECT_TYPE. However, that is clearly what is
1827 if (DECL_P (member))
1829 member_scope = DECL_CLASS_CONTEXT (member);
1831 if (TREE_DEPRECATED (member))
1832 warn_deprecated_use (member);
1835 member_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (member));
1836 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1837 presently be the anonymous union. Go outwards until we find a
1838 type related to OBJECT_TYPE. */
1839 while (ANON_AGGR_TYPE_P (member_scope)
1840 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1842 member_scope = TYPE_CONTEXT (member_scope);
1843 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1845 if (TREE_CODE (member) == FIELD_DECL)
1846 error ("invalid use of nonstatic data member %qE", member);
1848 error ("%qD is not a member of %qT", member, object_type);
1849 return error_mark_node;
1852 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1853 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1854 in the front end; only _DECLs and _REFs are lvalues in the back end. */
1856 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1858 object = build_indirect_ref (temp, NULL);
1861 /* In [expr.ref], there is an explicit list of the valid choices for
1862 MEMBER. We check for each of those cases here. */
1863 if (TREE_CODE (member) == VAR_DECL)
1865 /* A static data member. */
1867 /* If OBJECT has side-effects, they are supposed to occur. */
1868 if (TREE_SIDE_EFFECTS (object))
1869 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1871 else if (TREE_CODE (member) == FIELD_DECL)
1873 /* A non-static data member. */
1878 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1879 && integer_zerop (TREE_OPERAND (object, 0)));
1881 /* Convert OBJECT to the type of MEMBER. */
1882 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1883 TYPE_MAIN_VARIANT (member_scope)))
1888 binfo = lookup_base (access_path ? access_path : object_type,
1889 member_scope, ba_unique, &kind);
1890 if (binfo == error_mark_node)
1891 return error_mark_node;
1893 /* It is invalid to try to get to a virtual base of a
1894 NULL object. The most common cause is invalid use of
1896 if (null_object_p && kind == bk_via_virtual)
1898 error ("invalid access to non-static data member %qD of "
1901 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1902 return error_mark_node;
1905 /* Convert to the base. */
1906 object = build_base_path (PLUS_EXPR, object, binfo,
1908 /* If we found the base successfully then we should be able
1909 to convert to it successfully. */
1910 gcc_assert (object != error_mark_node);
1913 /* Complain about other invalid uses of offsetof, even though they will
1914 give the right answer. Note that we complain whether or not they
1915 actually used the offsetof macro, since there's no way to know at this
1916 point. So we just give a warning, instead of a pedwarn. */
1917 /* Do not produce this warning for base class field references, because
1918 we know for a fact that didn't come from offsetof. This does occur
1919 in various testsuite cases where a null object is passed where a
1920 vtable access is required. */
1921 if (null_object_p && warn_invalid_offsetof
1922 && CLASSTYPE_NON_POD_P (object_type)
1923 && !DECL_FIELD_IS_BASE (member)
1924 && !skip_evaluation)
1926 warning (0, "invalid access to non-static data member %qD of NULL object",
1928 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1931 /* If MEMBER is from an anonymous aggregate, we have converted
1932 OBJECT so that it refers to the class containing the
1933 anonymous union. Generate a reference to the anonymous union
1934 itself, and recur to find MEMBER. */
1935 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1936 /* When this code is called from build_field_call, the
1937 object already has the type of the anonymous union.
1938 That is because the COMPONENT_REF was already
1939 constructed, and was then disassembled before calling
1940 build_field_call. After the function-call code is
1941 cleaned up, this waste can be eliminated. */
1942 && (!same_type_ignoring_top_level_qualifiers_p
1943 (TREE_TYPE (object), DECL_CONTEXT (member))))
1945 tree anonymous_union;
1947 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1948 DECL_CONTEXT (member));
1949 object = build_class_member_access_expr (object,
1951 /*access_path=*/NULL_TREE,
1952 preserve_reference);
1955 /* Compute the type of the field, as described in [expr.ref]. */
1956 type_quals = TYPE_UNQUALIFIED;
1957 member_type = TREE_TYPE (member);
1958 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1960 type_quals = (cp_type_quals (member_type)
1961 | cp_type_quals (object_type));
1963 /* A field is const (volatile) if the enclosing object, or the
1964 field itself, is const (volatile). But, a mutable field is
1965 not const, even within a const object. */
1966 if (DECL_MUTABLE_P (member))
1967 type_quals &= ~TYPE_QUAL_CONST;
1968 member_type = cp_build_qualified_type (member_type, type_quals);
1971 result = build3 (COMPONENT_REF, member_type, object, member,
1973 result = fold_if_not_in_template (result);
1975 /* Mark the expression const or volatile, as appropriate. Even
1976 though we've dealt with the type above, we still have to mark the
1977 expression itself. */
1978 if (type_quals & TYPE_QUAL_CONST)
1979 TREE_READONLY (result) = 1;
1980 if (type_quals & TYPE_QUAL_VOLATILE)
1981 TREE_THIS_VOLATILE (result) = 1;
1983 else if (BASELINK_P (member))
1985 /* The member is a (possibly overloaded) member function. */
1989 /* If the MEMBER is exactly one static member function, then we
1990 know the type of the expression. Otherwise, we must wait
1991 until overload resolution has been performed. */
1992 functions = BASELINK_FUNCTIONS (member);
1993 if (TREE_CODE (functions) == FUNCTION_DECL
1994 && DECL_STATIC_FUNCTION_P (functions))
1995 type = TREE_TYPE (functions);
1997 type = unknown_type_node;
1998 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1999 base. That will happen when the function is called. */
2000 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
2002 else if (TREE_CODE (member) == CONST_DECL)
2004 /* The member is an enumerator. */
2006 /* If OBJECT has side-effects, they are supposed to occur. */
2007 if (TREE_SIDE_EFFECTS (object))
2008 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
2013 error ("invalid use of %qD", member);
2014 return error_mark_node;
2017 if (!preserve_reference)
2020 If E2 is declared to have type "reference to T", then ... the
2021 type of E1.E2 is T. */
2022 result = convert_from_reference (result);
2027 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
2028 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2031 lookup_destructor (tree object, tree scope, tree dtor_name)
2033 tree object_type = TREE_TYPE (object);
2034 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2037 if (scope && !check_dtor_name (scope, dtor_type))
2039 error ("qualified type %qT does not match destructor name ~%qT",
2041 return error_mark_node;
2043 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2045 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2046 TYPE_MAIN_VARIANT (object_type), dtor_type);
2047 return error_mark_node;
2049 expr = lookup_member (dtor_type, complete_dtor_identifier,
2050 /*protect=*/1, /*want_type=*/false);
2051 expr = (adjust_result_of_qualified_name_lookup
2052 (expr, dtor_type, object_type));
2056 /* An expression of the form "A::template B" has been resolved to
2057 DECL. Issue a diagnostic if B is not a template or template
2061 check_template_keyword (tree decl)
2063 /* The standard says:
2067 If a name prefixed by the keyword template is not a member
2068 template, the program is ill-formed.
2070 DR 228 removed the restriction that the template be a member
2073 DR 96, if accepted would add the further restriction that explicit
2074 template arguments must be provided if the template keyword is
2075 used, but, as of 2005-10-16, that DR is still in "drafting". If
2076 this DR is accepted, then the semantic checks here can be
2077 simplified, as the entity named must in fact be a template
2078 specialization, rather than, as at present, a set of overloaded
2079 functions containing at least one template function. */
2080 if (TREE_CODE (decl) != TEMPLATE_DECL
2081 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2083 if (!is_overloaded_fn (decl))
2084 pedwarn ("%qD is not a template", decl);
2089 if (BASELINK_P (fns))
2090 fns = BASELINK_FUNCTIONS (fns);
2093 tree fn = OVL_CURRENT (fns);
2094 if (TREE_CODE (fn) == TEMPLATE_DECL
2095 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2097 if (TREE_CODE (fn) == FUNCTION_DECL
2098 && DECL_USE_TEMPLATE (fn)
2099 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2101 fns = OVL_NEXT (fns);
2104 pedwarn ("%qD is not a template", decl);
2109 /* This function is called by the parser to process a class member
2110 access expression of the form OBJECT.NAME. NAME is a node used by
2111 the parser to represent a name; it is not yet a DECL. It may,
2112 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2113 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2114 there is no reason to do the lookup twice, so the parser keeps the
2115 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2116 be a template via the use of the "A::template B" syntax. */
2119 finish_class_member_access_expr (tree object, tree name, bool template_p)
2124 tree access_path = NULL_TREE;
2125 tree orig_object = object;
2126 tree orig_name = name;
2128 if (object == error_mark_node || name == error_mark_node)
2129 return error_mark_node;
2131 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2132 if (!objc_is_public (object, name))
2133 return error_mark_node;
2135 object_type = TREE_TYPE (object);
2137 if (processing_template_decl)
2139 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2140 dependent_type_p (object_type)
2141 /* If NAME is just an IDENTIFIER_NODE, then the expression
2143 || TREE_CODE (object) == IDENTIFIER_NODE
2144 /* If NAME is "f<args>", where either 'f' or 'args' is
2145 dependent, then the expression is dependent. */
2146 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2147 && dependent_template_id_p (TREE_OPERAND (name, 0),
2148 TREE_OPERAND (name, 1)))
2149 /* If NAME is "T::X" where "T" is dependent, then the
2150 expression is dependent. */
2151 || (TREE_CODE (name) == SCOPE_REF
2152 && TYPE_P (TREE_OPERAND (name, 0))
2153 && dependent_type_p (TREE_OPERAND (name, 0))))
2154 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2155 object = build_non_dependent_expr (object);
2160 The type of the first expression shall be "class object" (of a
2162 if (!currently_open_class (object_type)
2163 && !complete_type_or_else (object_type, object))
2164 return error_mark_node;
2165 if (!CLASS_TYPE_P (object_type))
2167 error ("request for member %qD in %qE, which is of non-class type %qT",
2168 name, object, object_type);
2169 return error_mark_node;
2172 if (BASELINK_P (name))
2173 /* A member function that has already been looked up. */
2177 bool is_template_id = false;
2178 tree template_args = NULL_TREE;
2181 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2183 is_template_id = true;
2184 template_args = TREE_OPERAND (name, 1);
2185 name = TREE_OPERAND (name, 0);
2187 if (TREE_CODE (name) == OVERLOAD)
2188 name = DECL_NAME (get_first_fn (name));
2189 else if (DECL_P (name))
2190 name = DECL_NAME (name);
2193 if (TREE_CODE (name) == SCOPE_REF)
2195 /* A qualified name. The qualifying class or namespace `S'
2196 has already been looked up; it is either a TYPE or a
2198 scope = TREE_OPERAND (name, 0);
2199 name = TREE_OPERAND (name, 1);
2201 /* If SCOPE is a namespace, then the qualified name does not
2202 name a member of OBJECT_TYPE. */
2203 if (TREE_CODE (scope) == NAMESPACE_DECL)
2205 error ("%<%D::%D%> is not a member of %qT",
2206 scope, name, object_type);
2207 return error_mark_node;
2210 gcc_assert (CLASS_TYPE_P (scope));
2211 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2212 || TREE_CODE (name) == BIT_NOT_EXPR);
2214 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2215 access_path = lookup_base (object_type, scope, ba_check, NULL);
2216 if (access_path == error_mark_node)
2217 return error_mark_node;
2220 error ("%qT is not a base of %qT", scope, object_type);
2221 return error_mark_node;
2227 access_path = object_type;
2230 if (TREE_CODE (name) == BIT_NOT_EXPR)
2231 member = lookup_destructor (object, scope, name);
2234 /* Look up the member. */
2235 member = lookup_member (access_path, name, /*protect=*/1,
2236 /*want_type=*/false);
2237 if (member == NULL_TREE)
2239 error ("%qD has no member named %qE", object_type, name);
2240 return error_mark_node;
2242 if (member == error_mark_node)
2243 return error_mark_node;
2248 tree template = member;
2250 if (BASELINK_P (template))
2251 template = lookup_template_function (template, template_args);
2254 error ("%qD is not a member template function", name);
2255 return error_mark_node;
2260 if (TREE_DEPRECATED (member))
2261 warn_deprecated_use (member);
2264 check_template_keyword (member);
2266 expr = build_class_member_access_expr (object, member, access_path,
2267 /*preserve_reference=*/false);
2268 if (processing_template_decl && expr != error_mark_node)
2270 if (BASELINK_P (member))
2272 if (TREE_CODE (orig_name) == SCOPE_REF)
2273 BASELINK_QUALIFIED_P (member) = 1;
2276 return build_min_non_dep (COMPONENT_REF, expr,
2277 orig_object, orig_name,
2284 /* Return an expression for the MEMBER_NAME field in the internal
2285 representation of PTRMEM, a pointer-to-member function. (Each
2286 pointer-to-member function type gets its own RECORD_TYPE so it is
2287 more convenient to access the fields by name than by FIELD_DECL.)
2288 This routine converts the NAME to a FIELD_DECL and then creates the
2289 node for the complete expression. */
2292 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2298 /* This code is a stripped down version of
2299 build_class_member_access_expr. It does not work to use that
2300 routine directly because it expects the object to be of class
2302 ptrmem_type = TREE_TYPE (ptrmem);
2303 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2304 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2305 /*want_type=*/false);
2306 member_type = cp_build_qualified_type (TREE_TYPE (member),
2307 cp_type_quals (ptrmem_type));
2308 return fold_build3 (COMPONENT_REF, member_type,
2309 ptrmem, member, NULL_TREE);
2312 /* Given an expression PTR for a pointer, return an expression
2313 for the value pointed to.
2314 ERRORSTRING is the name of the operator to appear in error messages.
2316 This function may need to overload OPERATOR_FNNAME.
2317 Must also handle REFERENCE_TYPEs for C++. */
2320 build_x_indirect_ref (tree expr, const char *errorstring)
2322 tree orig_expr = expr;
2325 if (processing_template_decl)
2327 if (type_dependent_expression_p (expr))
2328 return build_min_nt (INDIRECT_REF, expr);
2329 expr = build_non_dependent_expr (expr);
2332 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2333 NULL_TREE, /*overloaded_p=*/NULL);
2335 rval = build_indirect_ref (expr, errorstring);
2337 if (processing_template_decl && rval != error_mark_node)
2338 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2344 build_indirect_ref (tree ptr, const char *errorstring)
2348 if (ptr == error_mark_node)
2349 return error_mark_node;
2351 if (ptr == current_class_ptr)
2352 return current_class_ref;
2354 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2355 ? ptr : decay_conversion (ptr));
2356 type = TREE_TYPE (pointer);
2358 if (POINTER_TYPE_P (type))
2362 If the type of the expression is "pointer to T," the type
2363 of the result is "T."
2365 We must use the canonical variant because certain parts of
2366 the back end, like fold, do pointer comparisons between
2368 tree t = canonical_type_variant (TREE_TYPE (type));
2370 if (TREE_CODE (ptr) == CONVERT_EXPR
2371 || TREE_CODE (ptr) == NOP_EXPR
2372 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2374 /* If a warning is issued, mark it to avoid duplicates from
2375 the backend. This only needs to be done at
2376 warn_strict_aliasing > 2. */
2377 if (warn_strict_aliasing > 2)
2378 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2379 type, TREE_OPERAND (ptr, 0)))
2380 TREE_NO_WARNING (ptr) = 1;
2383 if (VOID_TYPE_P (t))
2385 /* A pointer to incomplete type (other than cv void) can be
2386 dereferenced [expr.unary.op]/1 */
2387 error ("%qT is not a pointer-to-object type", type);
2388 return error_mark_node;
2390 else if (TREE_CODE (pointer) == ADDR_EXPR
2391 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2392 /* The POINTER was something like `&x'. We simplify `*&x' to
2394 return TREE_OPERAND (pointer, 0);
2397 tree ref = build1 (INDIRECT_REF, t, pointer);
2399 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2400 so that we get the proper error message if the result is used
2401 to assign to. Also, &* is supposed to be a no-op. */
2402 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2403 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2404 TREE_SIDE_EFFECTS (ref)
2405 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2409 /* `pointer' won't be an error_mark_node if we were given a
2410 pointer to member, so it's cool to check for this here. */
2411 else if (TYPE_PTR_TO_MEMBER_P (type))
2412 error ("invalid use of %qs on pointer to member", errorstring);
2413 else if (pointer != error_mark_node)
2416 error ("invalid type argument of %qs", errorstring);
2418 error ("invalid type argument");
2420 return error_mark_node;
2423 /* This handles expressions of the form "a[i]", which denotes
2426 This is logically equivalent in C to *(a+i), but we may do it differently.
2427 If A is a variable or a member, we generate a primitive ARRAY_REF.
2428 This avoids forcing the array out of registers, and can work on
2429 arrays that are not lvalues (for example, members of structures returned
2432 If INDEX is of some user-defined type, it must be converted to
2433 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2434 will inherit the type of the array, which will be some pointer type. */
2437 build_array_ref (tree array, tree idx)
2441 error ("subscript missing in array reference");
2442 return error_mark_node;
2445 if (TREE_TYPE (array) == error_mark_node
2446 || TREE_TYPE (idx) == error_mark_node)
2447 return error_mark_node;
2449 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2451 switch (TREE_CODE (array))
2455 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2456 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2457 TREE_OPERAND (array, 0), value);
2461 return build_conditional_expr
2462 (TREE_OPERAND (array, 0),
2463 build_array_ref (TREE_OPERAND (array, 1), idx),
2464 build_array_ref (TREE_OPERAND (array, 2), idx));
2470 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2474 warn_array_subscript_with_type_char (idx);
2476 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2478 error ("array subscript is not an integer");
2479 return error_mark_node;
2482 /* Apply integral promotions *after* noticing character types.
2483 (It is unclear why we do these promotions -- the standard
2484 does not say that we should. In fact, the natural thing would
2485 seem to be to convert IDX to ptrdiff_t; we're performing
2486 pointer arithmetic.) */
2487 idx = perform_integral_promotions (idx);
2489 /* An array that is indexed by a non-constant
2490 cannot be stored in a register; we must be able to do
2491 address arithmetic on its address.
2492 Likewise an array of elements of variable size. */
2493 if (TREE_CODE (idx) != INTEGER_CST
2494 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2495 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2498 if (!cxx_mark_addressable (array))
2499 return error_mark_node;
2502 /* An array that is indexed by a constant value which is not within
2503 the array bounds cannot be stored in a register either; because we
2504 would get a crash in store_bit_field/extract_bit_field when trying
2505 to access a non-existent part of the register. */
2506 if (TREE_CODE (idx) == INTEGER_CST
2507 && TYPE_DOMAIN (TREE_TYPE (array))
2508 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2510 if (!cxx_mark_addressable (array))
2511 return error_mark_node;
2514 if (pedantic && !lvalue_p (array))
2515 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2517 /* Note in C++ it is valid to subscript a `register' array, since
2518 it is valid to take the address of something with that
2519 storage specification. */
2523 while (TREE_CODE (foo) == COMPONENT_REF)
2524 foo = TREE_OPERAND (foo, 0);
2525 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2526 warning (OPT_Wextra, "subscripting array declared %<register%>");
2529 type = TREE_TYPE (TREE_TYPE (array));
2530 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2531 /* Array ref is const/volatile if the array elements are
2532 or if the array is.. */
2533 TREE_READONLY (rval)
2534 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2535 TREE_SIDE_EFFECTS (rval)
2536 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2537 TREE_THIS_VOLATILE (rval)
2538 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2539 return require_complete_type (fold_if_not_in_template (rval));
2543 tree ar = default_conversion (array);
2544 tree ind = default_conversion (idx);
2546 /* Put the integer in IND to simplify error checking. */
2547 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2554 if (ar == error_mark_node)
2557 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2559 error ("subscripted value is neither array nor pointer");
2560 return error_mark_node;
2562 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2564 error ("array subscript is not an integer");
2565 return error_mark_node;
2568 warn_array_subscript_with_type_char (idx);
2570 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2575 /* Resolve a pointer to member function. INSTANCE is the object
2576 instance to use, if the member points to a virtual member.
2578 This used to avoid checking for virtual functions if basetype
2579 has no virtual functions, according to an earlier ANSI draft.
2580 With the final ISO C++ rules, such an optimization is
2581 incorrect: A pointer to a derived member can be static_cast
2582 to pointer-to-base-member, as long as the dynamic object
2583 later has the right member. */
2586 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2588 if (TREE_CODE (function) == OFFSET_REF)
2589 function = TREE_OPERAND (function, 1);
2591 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2593 tree idx, delta, e1, e2, e3, vtbl, basetype;
2594 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2596 tree instance_ptr = *instance_ptrptr;
2597 tree instance_save_expr = 0;
2598 if (instance_ptr == error_mark_node)
2600 if (TREE_CODE (function) == PTRMEM_CST)
2602 /* Extracting the function address from a pmf is only
2603 allowed with -Wno-pmf-conversions. It only works for
2605 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2606 e1 = convert (fntype, e1);
2611 error ("object missing in use of %qE", function);
2612 return error_mark_node;
2616 if (TREE_SIDE_EFFECTS (instance_ptr))
2617 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2619 if (TREE_SIDE_EFFECTS (function))
2620 function = save_expr (function);
2622 /* Start by extracting all the information from the PMF itself. */
2623 e3 = pfn_from_ptrmemfunc (function);
2624 delta = delta_from_ptrmemfunc (function);
2625 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2626 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2628 case ptrmemfunc_vbit_in_pfn:
2629 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2630 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2633 case ptrmemfunc_vbit_in_delta:
2634 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2635 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2642 /* Convert down to the right base before using the instance. A
2643 special case is that in a pointer to member of class C, C may
2644 be incomplete. In that case, the function will of course be
2645 a member of C, and no conversion is required. In fact,
2646 lookup_base will fail in that case, because incomplete
2647 classes do not have BINFOs. */
2648 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2649 if (!same_type_ignoring_top_level_qualifiers_p
2650 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2652 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2653 basetype, ba_check, NULL);
2654 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2656 if (instance_ptr == error_mark_node)
2657 return error_mark_node;
2659 /* ...and then the delta in the PMF. */
2660 instance_ptr = build2 (POINTER_PLUS_EXPR, TREE_TYPE (instance_ptr),
2661 instance_ptr, fold_convert (sizetype, delta));
2663 /* Hand back the adjusted 'this' argument to our caller. */
2664 *instance_ptrptr = instance_ptr;
2666 /* Next extract the vtable pointer from the object. */
2667 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2669 vtbl = build_indirect_ref (vtbl, NULL);
2671 /* Finally, extract the function pointer from the vtable. */
2672 e2 = fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl,
2673 fold_convert (sizetype, idx));
2674 e2 = build_indirect_ref (e2, NULL);
2675 TREE_CONSTANT (e2) = 1;
2676 TREE_INVARIANT (e2) = 1;
2678 /* When using function descriptors, the address of the
2679 vtable entry is treated as a function pointer. */
2680 if (TARGET_VTABLE_USES_DESCRIPTORS)
2681 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2682 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2684 e2 = fold_convert (TREE_TYPE (e3), e2);
2685 e1 = build_conditional_expr (e1, e2, e3);
2687 /* Make sure this doesn't get evaluated first inside one of the
2688 branches of the COND_EXPR. */
2689 if (instance_save_expr)
2690 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2691 instance_save_expr, e1);
2699 build_function_call (tree function, tree params)
2701 tree fntype, fndecl;
2702 tree name = NULL_TREE;
2704 tree original = function;
2705 int nargs, parm_types_len;
2709 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2710 expressions, like those used for ObjC messenger dispatches. */
2711 function = objc_rewrite_function_call (function, params);
2713 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2714 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2715 if (TREE_CODE (function) == NOP_EXPR
2716 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2717 function = TREE_OPERAND (function, 0);
2719 if (TREE_CODE (function) == FUNCTION_DECL)
2721 name = DECL_NAME (function);
2723 mark_used (function);
2726 /* Convert anything with function type to a pointer-to-function. */
2727 if (pedantic && DECL_MAIN_P (function))
2728 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2730 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2731 (because calling an inline function does not mean the function
2732 needs to be separately compiled). */
2734 if (DECL_INLINE (function))
2735 function = inline_conversion (function);
2737 function = build_addr_func (function);
2743 function = build_addr_func (function);
2746 if (function == error_mark_node)
2747 return error_mark_node;
2749 fntype = TREE_TYPE (function);
2751 if (TYPE_PTRMEMFUNC_P (fntype))
2753 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2754 "function in %<%E (...)%>",
2756 return error_mark_node;
2759 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2760 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2762 if (!((TREE_CODE (fntype) == POINTER_TYPE
2763 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2765 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2767 error ("%qE cannot be used as a function", original);
2768 return error_mark_node;
2771 /* fntype now gets the type of function pointed to. */
2772 fntype = TREE_TYPE (fntype);
2773 parm_types = TYPE_ARG_TYPES (fntype);
2775 /* Allocate storage for converted arguments. */
2776 parm_types_len = list_length (parm_types);
2777 nargs = list_length (params);
2778 if (parm_types_len > nargs)
2779 nargs = parm_types_len;
2780 argarray = (tree *) alloca (nargs * sizeof (tree));
2782 /* Convert the parameters to the types declared in the
2783 function prototype, or apply default promotions. */
2784 nargs = convert_arguments (nargs, argarray, parm_types,
2785 params, fndecl, LOOKUP_NORMAL);
2787 return error_mark_node;
2789 /* Check for errors in format strings and inappropriately
2792 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2795 return build_cxx_call (function, nargs, argarray);
2798 /* Convert the actual parameter expressions in the list VALUES
2799 to the types in the list TYPELIST.
2800 If parmdecls is exhausted, or when an element has NULL as its type,
2801 perform the default conversions.
2803 Store the converted arguments in ARGARRAY. NARGS is the size of this array.
2805 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2807 This is also where warnings about wrong number of args are generated.
2809 Returns the actual number of arguments processed (which might be less
2810 than NARGS), or -1 on error.
2812 VALUES is a chain of TREE_LIST nodes with the elements of the list
2813 in the TREE_VALUE slots of those nodes.
2815 In C++, unspecified trailing parameters can be filled in with their
2816 default arguments, if such were specified. Do so here. */
2819 convert_arguments (int nargs, tree *argarray,
2820 tree typelist, tree values, tree fndecl, int flags)
2822 tree typetail, valtail;
2823 const char *called_thing = 0;
2826 /* Argument passing is always copy-initialization. */
2827 flags |= LOOKUP_ONLYCONVERTING;
2831 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2833 if (DECL_NAME (fndecl) == NULL_TREE
2834 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2835 called_thing = "constructor";
2837 called_thing = "member function";
2840 called_thing = "function";
2843 for (valtail = values, typetail = typelist;
2845 valtail = TREE_CHAIN (valtail), i++)
2847 tree type = typetail ? TREE_VALUE (typetail) : 0;
2848 tree val = TREE_VALUE (valtail);
2850 if (val == error_mark_node || type == error_mark_node)
2853 if (type == void_type_node)
2857 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2858 error ("at this point in file");
2861 error ("too many arguments to function");
2865 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2866 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2867 if (TREE_CODE (val) == NOP_EXPR
2868 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2869 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2870 val = TREE_OPERAND (val, 0);
2872 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2874 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2875 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2876 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2877 val = decay_conversion (val);
2880 if (val == error_mark_node)
2885 /* Formal parm type is specified by a function prototype. */
2888 if (!COMPLETE_TYPE_P (complete_type (type)))
2891 error ("parameter %P of %qD has incomplete type %qT",
2894 error ("parameter %P has incomplete type %qT", i, type);
2895 parmval = error_mark_node;
2899 parmval = convert_for_initialization
2900 (NULL_TREE, type, val, flags,
2901 "argument passing", fndecl, i);
2902 parmval = convert_for_arg_passing (type, parmval);
2905 if (parmval == error_mark_node)
2908 argarray[i] = parmval;
2912 if (fndecl && DECL_BUILT_IN (fndecl)
2913 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2914 /* Don't do ellipsis conversion for __built_in_constant_p
2915 as this will result in spurious warnings for non-POD
2917 val = require_complete_type (val);
2919 val = convert_arg_to_ellipsis (val);
2925 typetail = TREE_CHAIN (typetail);
2928 if (typetail != 0 && typetail != void_list_node)
2930 /* See if there are default arguments that can be used. Because
2931 we hold default arguments in the FUNCTION_TYPE (which is so
2932 wrong), we can see default parameters here from deduced
2933 contexts (and via typeof) for indirect function calls.
2934 Fortunately we know whether we have a function decl to
2935 provide default arguments in a language conformant
2937 if (fndecl && TREE_PURPOSE (typetail)
2938 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2940 for (; typetail != void_list_node; ++i)
2943 = convert_default_arg (TREE_VALUE (typetail),
2944 TREE_PURPOSE (typetail),
2947 if (parmval == error_mark_node)
2950 argarray[i] = parmval;
2951 typetail = TREE_CHAIN (typetail);
2952 /* ends with `...'. */
2953 if (typetail == NULL_TREE)
2961 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2962 error ("at this point in file");
2965 error ("too few arguments to function");
2970 gcc_assert (i <= nargs);
2974 /* Build a binary-operation expression, after performing default
2975 conversions on the operands. CODE is the kind of expression to
2976 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2977 are the tree codes which correspond to ARG1 and ARG2 when issuing
2978 warnings about possibly misplaced parentheses. They may differ
2979 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2980 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2981 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2982 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2983 ARG2_CODE as ERROR_MARK. */
2986 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2987 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2996 if (processing_template_decl)
2998 if (type_dependent_expression_p (arg1)
2999 || type_dependent_expression_p (arg2))
3000 return build_min_nt (code, arg1, arg2);
3001 arg1 = build_non_dependent_expr (arg1);
3002 arg2 = build_non_dependent_expr (arg2);
3005 if (code == DOTSTAR_EXPR)
3006 expr = build_m_component_ref (arg1, arg2);
3008 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
3011 /* Check for cases such as x+y<<z which users are likely to
3012 misinterpret. But don't warn about obj << x + y, since that is a
3013 common idiom for I/O. */
3014 if (warn_parentheses
3015 && !processing_template_decl
3016 && !error_operand_p (arg1)
3017 && !error_operand_p (arg2)
3018 && (code != LSHIFT_EXPR
3019 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
3020 warn_about_parentheses (code, arg1_code, arg2_code);
3022 if (processing_template_decl && expr != error_mark_node)
3023 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
3028 /* Build a binary-operation expression without default conversions.
3029 CODE is the kind of expression to build.
3030 This function differs from `build' in several ways:
3031 the data type of the result is computed and recorded in it,
3032 warnings are generated if arg data types are invalid,
3033 special handling for addition and subtraction of pointers is known,
3034 and some optimization is done (operations on narrow ints
3035 are done in the narrower type when that gives the same result).
3036 Constant folding is also done before the result is returned.
3038 Note that the operands will never have enumeral types
3039 because either they have just had the default conversions performed
3040 or they have both just been converted to some other type in which
3041 the arithmetic is to be done.
3043 C++: must do special pointer arithmetic when implementing
3044 multiple inheritance, and deal with pointer to member functions. */
3047 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
3048 int convert_p ATTRIBUTE_UNUSED)
3051 enum tree_code code0, code1;
3053 const char *invalid_op_diag;
3055 /* Expression code to give to the expression when it is built.
3056 Normally this is CODE, which is what the caller asked for,
3057 but in some special cases we change it. */
3058 enum tree_code resultcode = code;
3060 /* Data type in which the computation is to be performed.
3061 In the simplest cases this is the common type of the arguments. */
3062 tree result_type = NULL;
3064 /* Nonzero means operands have already been type-converted
3065 in whatever way is necessary.
3066 Zero means they need to be converted to RESULT_TYPE. */
3069 /* Nonzero means create the expression with this type, rather than
3071 tree build_type = 0;
3073 /* Nonzero means after finally constructing the expression
3074 convert it to this type. */
3075 tree final_type = 0;
3079 /* Nonzero if this is an operation like MIN or MAX which can
3080 safely be computed in short if both args are promoted shorts.
3081 Also implies COMMON.
3082 -1 indicates a bitwise operation; this makes a difference
3083 in the exact conditions for when it is safe to do the operation
3084 in a narrower mode. */
3087 /* Nonzero if this is a comparison operation;
3088 if both args are promoted shorts, compare the original shorts.
3089 Also implies COMMON. */
3090 int short_compare = 0;
3092 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3095 /* True if both operands have arithmetic type. */
3096 bool arithmetic_types_p;
3098 /* Apply default conversions. */
3102 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3103 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3104 || code == TRUTH_XOR_EXPR)
3106 if (!really_overloaded_fn (op0))
3107 op0 = decay_conversion (op0);
3108 if (!really_overloaded_fn (op1))
3109 op1 = decay_conversion (op1);
3113 if (!really_overloaded_fn (op0))
3114 op0 = default_conversion (op0);
3115 if (!really_overloaded_fn (op1))
3116 op1 = default_conversion (op1);
3119 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3120 STRIP_TYPE_NOPS (op0);
3121 STRIP_TYPE_NOPS (op1);
3123 /* DTRT if one side is an overloaded function, but complain about it. */
3124 if (type_unknown_p (op0))
3126 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3127 if (t != error_mark_node)
3129 pedwarn ("assuming cast to type %qT from overloaded function",
3134 if (type_unknown_p (op1))
3136 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3137 if (t != error_mark_node)
3139 pedwarn ("assuming cast to type %qT from overloaded function",
3145 type0 = TREE_TYPE (op0);
3146 type1 = TREE_TYPE (op1);
3148 /* The expression codes of the data types of the arguments tell us
3149 whether the arguments are integers, floating, pointers, etc. */
3150 code0 = TREE_CODE (type0);
3151 code1 = TREE_CODE (type1);
3153 /* If an error was already reported for one of the arguments,
3154 avoid reporting another error. */
3156 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3157 return error_mark_node;
3159 if ((invalid_op_diag
3160 = targetm.invalid_binary_op (code, type0, type1)))
3162 error (invalid_op_diag);
3163 return error_mark_node;
3169 /* Subtraction of two similar pointers.
3170 We must subtract them as integers, then divide by object size. */
3171 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3172 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3174 return pointer_diff (op0, op1, common_type (type0, type1));
3175 /* In all other cases except pointer - int, the usual arithmetic
3177 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3182 /* The pointer - int case is just like pointer + int; fall
3185 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3186 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3190 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3191 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3192 if (processing_template_decl)
3194 result_type = TREE_TYPE (ptr_operand);
3197 return cp_pointer_int_sum (code,
3208 case TRUNC_DIV_EXPR:
3210 case FLOOR_DIV_EXPR:
3211 case ROUND_DIV_EXPR:
3212 case EXACT_DIV_EXPR:
3213 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3214 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3215 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3216 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3218 enum tree_code tcode0 = code0, tcode1 = code1;
3220 warn_for_div_by_zero (op1);
3222 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3223 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3224 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3225 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3227 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3228 resultcode = RDIV_EXPR;
3230 /* When dividing two signed integers, we have to promote to int.
3231 unless we divide by a constant != -1. Note that default
3232 conversion will have been performed on the operands at this
3233 point, so we have to dig out the original type to find out if
3235 shorten = ((TREE_CODE (op0) == NOP_EXPR
3236 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3237 || (TREE_CODE (op1) == INTEGER_CST
3238 && ! integer_all_onesp (op1)));
3247 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3248 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
3249 && !VECTOR_FLOAT_TYPE_P (type0)
3250 && !VECTOR_FLOAT_TYPE_P (type1)))
3254 case TRUNC_MOD_EXPR:
3255 case FLOOR_MOD_EXPR:
3256 warn_for_div_by_zero (op1);
3258 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3260 /* Although it would be tempting to shorten always here, that loses
3261 on some targets, since the modulo instruction is undefined if the
3262 quotient can't be represented in the computation mode. We shorten
3263 only if unsigned or if dividing by something we know != -1. */
3264 shorten = ((TREE_CODE (op0) == NOP_EXPR
3265 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3266 || (TREE_CODE (op1) == INTEGER_CST
3267 && ! integer_all_onesp (op1)));
3272 case TRUTH_ANDIF_EXPR:
3273 case TRUTH_ORIF_EXPR:
3274 case TRUTH_AND_EXPR:
3276 result_type = boolean_type_node;
3279 /* Shift operations: result has same type as first operand;
3280 always convert second operand to int.
3281 Also set SHORT_SHIFT if shifting rightward. */
3284 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3286 result_type = type0;
3287 if (TREE_CODE (op1) == INTEGER_CST)
3289 if (tree_int_cst_lt (op1, integer_zero_node))
3290 warning (0, "right shift count is negative");
3293 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3294 warning (0, "right shift count >= width of type");
3297 /* Convert the shift-count to an integer, regardless of
3298 size of value being shifted. */
3299 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3300 op1 = cp_convert (integer_type_node, op1);
3301 /* Avoid converting op1 to result_type later. */
3307 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3309 result_type = type0;
3310 if (TREE_CODE (op1) == INTEGER_CST)
3312 if (tree_int_cst_lt (op1, integer_zero_node))
3313 warning (0, "left shift count is negative");
3314 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3315 warning (0, "left shift count >= width of type");
3317 /* Convert the shift-count to an integer, regardless of
3318 size of value being shifted. */
3319 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3320 op1 = cp_convert (integer_type_node, op1);
3321 /* Avoid converting op1 to result_type later. */
3328 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3330 result_type = type0;
3331 if (TREE_CODE (op1) == INTEGER_CST)
3333 if (tree_int_cst_lt (op1, integer_zero_node))
3334 warning (0, (code == LROTATE_EXPR)
3335 ? G_("left rotate count is negative")
3336 : G_("right rotate count is negative"));
3337 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3338 warning (0, (code == LROTATE_EXPR)
3339 ? G_("left rotate count >= width of type")
3340 : G_("right rotate count >= width of type"));
3342 /* Convert the shift-count to an integer, regardless of
3343 size of value being shifted. */
3344 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3345 op1 = cp_convert (integer_type_node, op1);
3351 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3352 warning (OPT_Wfloat_equal,
3353 "comparing floating point with == or != is unsafe");
3354 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3355 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3356 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3358 build_type = boolean_type_node;
3359 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3360 || code0 == COMPLEX_TYPE)
3361 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3362 || code1 == COMPLEX_TYPE))
3364 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3365 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3366 result_type = composite_pointer_type (type0, type1, op0, op1,
3368 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3369 && null_ptr_cst_p (op1))
3371 if (TREE_CODE (op0) == ADDR_EXPR
3372 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
3373 warning (OPT_Waddress, "the address of %qD will never be NULL",
3374 TREE_OPERAND (op0, 0));
3375 result_type = type0;
3377 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3378 && null_ptr_cst_p (op0))
3380 if (TREE_CODE (op1) == ADDR_EXPR
3381 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
3382 warning (OPT_Waddress, "the address of %qD will never be NULL",
3383 TREE_OPERAND (op1, 0));
3384 result_type = type1;
3386 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3388 result_type = type0;
3389 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3391 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3393 result_type = type1;
3394 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3396 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3398 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3399 == ptrmemfunc_vbit_in_delta)
3401 tree pfn0 = pfn_from_ptrmemfunc (op0);
3402 tree delta0 = delta_from_ptrmemfunc (op0);
3403 tree e1 = cp_build_binary_op (EQ_EXPR,
3405 fold_convert (TREE_TYPE (pfn0),
3406 integer_zero_node));
3407 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3410 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3411 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3412 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3416 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3417 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3419 result_type = TREE_TYPE (op0);
3421 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3422 return cp_build_binary_op (code, op1, op0);
3423 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1))
3426 /* E will be the final comparison. */
3428 /* E1 and E2 are for scratch. */
3436 type = composite_pointer_type (type0, type1, op0, op1, "comparison");
3438 if (!same_type_p (TREE_TYPE (op0), type))
3439 op0 = cp_convert_and_check (type, op0);
3440 if (!same_type_p (TREE_TYPE (op1), type))
3441 op1 = cp_convert_and_check (type, op1);
3443 if (op0 == error_mark_node || op1 == error_mark_node)
3444 return error_mark_node;
3446 if (TREE_SIDE_EFFECTS (op0))
3447 op0 = save_expr (op0);
3448 if (TREE_SIDE_EFFECTS (op1))
3449 op1 = save_expr (op1);
3451 pfn0 = pfn_from_ptrmemfunc (op0);
3452 pfn1 = pfn_from_ptrmemfunc (op1);
3453 delta0 = delta_from_ptrmemfunc (op0);
3454 delta1 = delta_from_ptrmemfunc (op1);
3455 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3456 == ptrmemfunc_vbit_in_delta)
3461 && ((op0.delta == op1.delta)
3462 || (!op0.pfn && op0.delta & 1 == 0
3463 && op1.delta & 1 == 0))
3465 The reason for the `!op0.pfn' bit is that a NULL
3466 pointer-to-member is any member with a zero PFN and
3467 LSB of the DELTA field is 0. */
3469 e1 = cp_build_binary_op (BIT_AND_EXPR,
3472 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3473 e2 = cp_build_binary_op (BIT_AND_EXPR,
3476 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3477 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3478 e2 = cp_build_binary_op (EQ_EXPR,
3480 fold_convert (TREE_TYPE (pfn0),
3481 integer_zero_node));
3482 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3483 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3484 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3491 && (!op0.pfn || op0.delta == op1.delta))
3493 The reason for the `!op0.pfn' bit is that a NULL
3494 pointer-to-member is any member with a zero PFN; the
3495 DELTA field is unspecified. */
3497 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3498 e2 = cp_build_binary_op (EQ_EXPR,
3500 fold_convert (TREE_TYPE (pfn0),
3501 integer_zero_node));
3502 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3504 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3505 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3506 if (code == EQ_EXPR)
3508 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3512 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3513 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3515 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3516 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3524 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3525 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3527 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3528 result_type = composite_pointer_type (type0, type1, op0, op1,
3536 if (TREE_CODE (orig_op0) == STRING_CST
3537 || TREE_CODE (orig_op1) == STRING_CST)
3538 warning (OPT_Waddress, "comparison with string literal results in unspecified behaviour");
3540 build_type = boolean_type_node;
3541 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3542 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3544 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3545 result_type = composite_pointer_type (type0, type1, op0, op1,
3547 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3548 && integer_zerop (op1))
3549 result_type = type0;
3550 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3551 && integer_zerop (op0))
3552 result_type = type1;
3553 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3555 result_type = type0;
3556 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3558 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3560 result_type = type1;
3561 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3565 case UNORDERED_EXPR:
3572 build_type = integer_type_node;
3573 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3575 error ("unordered comparison on non-floating point argument");
3576 return error_mark_node;
3585 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3586 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3587 || code1 == COMPLEX_TYPE)))
3588 arithmetic_types_p = 1;
3591 arithmetic_types_p = 0;
3592 /* Vector arithmetic is only allowed when both sides are vectors. */
3593 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3595 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3596 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3599 binary_op_error (code, type0, type1);
3600 return error_mark_node;
3602 arithmetic_types_p = 1;
3605 /* Determine the RESULT_TYPE, if it is not already known. */
3607 && arithmetic_types_p
3608 && (shorten || common || short_compare))
3609 result_type = common_type (type0, type1);
3613 error ("invalid operands of types %qT and %qT to binary %qO",
3614 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3615 return error_mark_node;
3618 /* If we're in a template, the only thing we need to know is the
3620 if (processing_template_decl)
3622 /* Since the middle-end checks the type when doing a build2, we
3623 need to build the tree in pieces. This built tree will never
3624 get out of the front-end as we replace it when instantiating
3626 tree tmp = build2 (resultcode,
3627 build_type ? build_type : result_type,
3629 TREE_OPERAND (tmp, 0) = op0;
3633 if (arithmetic_types_p)
3635 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3637 /* For certain operations (which identify themselves by shorten != 0)
3638 if both args were extended from the same smaller type,
3639 do the arithmetic in that type and then extend.
3641 shorten !=0 and !=1 indicates a bitwise operation.
3642 For them, this optimization is safe only if
3643 both args are zero-extended or both are sign-extended.
3644 Otherwise, we might change the result.
3645 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3646 but calculated in (unsigned short) it would be (unsigned short)-1. */
3648 if (shorten && none_complex)
3650 int unsigned0, unsigned1;
3651 tree arg0 = get_narrower (op0, &unsigned0);
3652 tree arg1 = get_narrower (op1, &unsigned1);
3653 /* UNS is 1 if the operation to be done is an unsigned one. */
3654 int uns = TYPE_UNSIGNED (result_type);
3657 final_type = result_type;
3659 /* Handle the case that OP0 does not *contain* a conversion
3660 but it *requires* conversion to FINAL_TYPE. */
3662 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3663 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3664 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3665 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3667 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3669 /* For bitwise operations, signedness of nominal type
3670 does not matter. Consider only how operands were extended. */
3674 /* Note that in all three cases below we refrain from optimizing
3675 an unsigned operation on sign-extended args.
3676 That would not be valid. */
3678 /* Both args variable: if both extended in same way
3679 from same width, do it in that width.
3680 Do it unsigned if args were zero-extended. */
3681 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3682 < TYPE_PRECISION (result_type))
3683 && (TYPE_PRECISION (TREE_TYPE (arg1))
3684 == TYPE_PRECISION (TREE_TYPE (arg0)))
3685 && unsigned0 == unsigned1
3686 && (unsigned0 || !uns))
3687 result_type = c_common_signed_or_unsigned_type
3688 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3689 else if (TREE_CODE (arg0) == INTEGER_CST
3690 && (unsigned1 || !uns)
3691 && (TYPE_PRECISION (TREE_TYPE (arg1))
3692 < TYPE_PRECISION (result_type))
3693 && (type = c_common_signed_or_unsigned_type
3694 (unsigned1, TREE_TYPE (arg1)),
3695 int_fits_type_p (arg0, type)))
3697 else if (TREE_CODE (arg1) == INTEGER_CST
3698 && (unsigned0 || !uns)
3699 && (TYPE_PRECISION (TREE_TYPE (arg0))
3700 < TYPE_PRECISION (result_type))
3701 && (type = c_common_signed_or_unsigned_type
3702 (unsigned0, TREE_TYPE (arg0)),
3703 int_fits_type_p (arg1, type)))
3707 /* Comparison operations are shortened too but differently.
3708 They identify themselves by setting short_compare = 1. */
3712 /* Don't write &op0, etc., because that would prevent op0
3713 from being kept in a register.
3714 Instead, make copies of the our local variables and
3715 pass the copies by reference, then copy them back afterward. */
3716 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3717 enum tree_code xresultcode = resultcode;
3719 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3721 return cp_convert (boolean_type_node, val);
3722 op0 = xop0, op1 = xop1;
3724 resultcode = xresultcode;
3727 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3728 && warn_sign_compare
3729 /* Do not warn until the template is instantiated; we cannot
3730 bound the ranges of the arguments until that point. */
3731 && !processing_template_decl)
3733 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3734 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3736 int unsignedp0, unsignedp1;
3737 tree primop0 = get_narrower (op0, &unsignedp0);
3738 tree primop1 = get_narrower (op1, &unsignedp1);
3740 /* Check for comparison of different enum types. */
3741 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3742 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3743 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3744 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3746 warning (OPT_Wsign_compare, "comparison between types %q#T and %q#T",
3747 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3750 /* Give warnings for comparisons between signed and unsigned
3751 quantities that may fail. */
3752 /* Do the checking based on the original operand trees, so that
3753 casts will be considered, but default promotions won't be. */
3755 /* Do not warn if the comparison is being done in a signed type,
3756 since the signed type will only be chosen if it can represent
3757 all the values of the unsigned type. */
3758 if (!TYPE_UNSIGNED (result_type))
3760 /* Do not warn if both operands are unsigned. */
3761 else if (op0_signed == op1_signed)
3763 /* Do not warn if the signed quantity is an unsuffixed
3764 integer literal (or some static constant expression
3765 involving such literals or a conditional expression
3766 involving such literals) and it is non-negative. */
3767 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3768 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3770 /* Do not warn if the comparison is an equality operation,
3771 the unsigned quantity is an integral constant and it does
3772 not use the most significant bit of result_type. */
3773 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3774 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3775 && int_fits_type_p (orig_op1, c_common_signed_type
3777 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3778 && int_fits_type_p (orig_op0, c_common_signed_type
3782 warning (OPT_Wsign_compare,
3783 "comparison between signed and unsigned integer expressions");
3785 /* Warn if two unsigned values are being compared in a size
3786 larger than their original size, and one (and only one) is the
3787 result of a `~' operator. This comparison will always fail.
3789 Also warn if one operand is a constant, and the constant does not
3790 have all bits set that are set in the ~ operand when it is
3793 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3794 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3796 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3797 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3798 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3799 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3801 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3804 HOST_WIDE_INT constant, mask;
3808 if (host_integerp (primop0, 0))
3811 unsignedp = unsignedp1;
3812 constant = tree_low_cst (primop0, 0);
3817 unsignedp = unsignedp0;
3818 constant = tree_low_cst (primop1, 0);
3821 bits = TYPE_PRECISION (TREE_TYPE (primop));
3822 if (bits < TYPE_PRECISION (result_type)
3823 && bits < HOST_BITS_PER_LONG && unsignedp)
3825 mask = (~ (HOST_WIDE_INT) 0) << bits;
3826 if ((mask & constant) != mask)
3827 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with constant");
3830 else if (unsignedp0 && unsignedp1
3831 && (TYPE_PRECISION (TREE_TYPE (primop0))
3832 < TYPE_PRECISION (result_type))
3833 && (TYPE_PRECISION (TREE_TYPE (primop1))
3834 < TYPE_PRECISION (result_type)))
3835 warning (OPT_Wsign_compare, "comparison of promoted ~unsigned with unsigned");
3840 /* Issue warnings about peculiar, but valid, uses of NULL. */
3841 if ((orig_op0 == null_node || orig_op1 == null_node)
3842 /* It's reasonable to use pointer values as operands of &&
3843 and ||, so NULL is no exception. */
3844 && code != TRUTH_ANDIF_EXPR && code != TRUTH_ORIF_EXPR
3845 && ( /* Both are NULL (or 0) and the operation was not a comparison. */
3846 (null_ptr_cst_p (orig_op0) && null_ptr_cst_p (orig_op1)
3847 && code != EQ_EXPR && code != NE_EXPR)
3848 /* Or if one of OP0 or OP1 is neither a pointer nor NULL. */
3849 || (!null_ptr_cst_p (orig_op0) && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3850 || (!null_ptr_cst_p (orig_op1) && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)))
3851 /* Some sort of arithmetic operation involving NULL was
3852 performed. Note that pointer-difference and pointer-addition
3853 have already been handled above, and so we don't end up here in
3855 warning (OPT_Wpointer_arith, "NULL used in arithmetic");
3858 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3859 Then the expression will be built.
3860 It will be given type FINAL_TYPE if that is nonzero;
3861 otherwise, it will be given type RESULT_TYPE. */
3864 if (TREE_TYPE (op0) != result_type)
3865 op0 = cp_convert_and_check (result_type, op0);
3866 if (TREE_TYPE (op1) != result_type)
3867 op1 = cp_convert_and_check (result_type, op1);
3869 if (op0 == error_mark_node || op1 == error_mark_node)
3870 return error_mark_node;
3873 if (build_type == NULL_TREE)
3874 build_type = result_type;
3876 result = build2 (resultcode, build_type, op0, op1);
3877 result = fold_if_not_in_template (result);
3878 if (final_type != 0)
3879 result = cp_convert (final_type, result);
3881 if (TREE_OVERFLOW_P (result)
3882 && !TREE_OVERFLOW_P (op0)
3883 && !TREE_OVERFLOW_P (op1))
3884 overflow_warning (result);
3889 /* Return a tree for the sum or difference (RESULTCODE says which)
3890 of pointer PTROP and integer INTOP. */
3893 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3895 tree res_type = TREE_TYPE (ptrop);
3897 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3898 in certain circumstance (when it's valid to do so). So we need
3899 to make sure it's complete. We don't need to check here, if we
3900 can actually complete it at all, as those checks will be done in
3901 pointer_int_sum() anyway. */
3902 complete_type (TREE_TYPE (res_type));
3904 return pointer_int_sum (resultcode, ptrop,
3905 fold_if_not_in_template (intop));
3908 /* Return a tree for the difference of pointers OP0 and OP1.
3909 The resulting tree has type int. */
3912 pointer_diff (tree op0, tree op1, tree ptrtype)
3915 tree restype = ptrdiff_type_node;
3916 tree target_type = TREE_TYPE (ptrtype);
3918 if (!complete_type_or_else (target_type, NULL_TREE))
3919 return error_mark_node;
3921 if (pedantic || warn_pointer_arith)
3923 if (TREE_CODE (target_type) == VOID_TYPE)
3924 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3925 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3926 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3927 if (TREE_CODE (target_type) == METHOD_TYPE)
3928 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3931 /* First do the subtraction as integers;
3932 then drop through to build the divide operator. */
3934 op0 = cp_build_binary_op (MINUS_EXPR,
3935 cp_convert (restype, op0),
3936 cp_convert (restype, op1));
3938 /* This generates an error if op1 is a pointer to an incomplete type. */
3939 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3940 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3942 op1 = (TYPE_PTROB_P (ptrtype)
3943 ? size_in_bytes (target_type)
3944 : integer_one_node);
3946 /* Do the division. */
3948 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3949 return fold_if_not_in_template (result);
3952 /* Construct and perhaps optimize a tree representation
3953 for a unary operation. CODE, a tree_code, specifies the operation
3954 and XARG is the operand. */
3957 build_x_unary_op (enum tree_code code, tree xarg)
3959 tree orig_expr = xarg;
3963 if (processing_template_decl)
3965 if (type_dependent_expression_p (xarg))
3966 return build_min_nt (code, xarg, NULL_TREE);
3968 xarg = build_non_dependent_expr (xarg);
3973 /* [expr.unary.op] says:
3975 The address of an object of incomplete type can be taken.
3977 (And is just the ordinary address operator, not an overloaded
3978 "operator &".) However, if the type is a template
3979 specialization, we must complete the type at this point so that
3980 an overloaded "operator &" will be available if required. */
3981 if (code == ADDR_EXPR
3982 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3983 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3984 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3985 || (TREE_CODE (xarg) == OFFSET_REF)))
3986 /* Don't look for a function. */;
3988 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3989 /*overloaded_p=*/NULL);
3990 if (!exp && code == ADDR_EXPR)
3992 /* A pointer to member-function can be formed only by saying
3994 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3995 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3997 if (TREE_CODE (xarg) != OFFSET_REF
3998 || !TYPE_P (TREE_OPERAND (xarg, 0)))
4000 error ("invalid use of %qE to form a pointer-to-member-function",
4002 if (TREE_CODE (xarg) != OFFSET_REF)
4003 inform (" a qualified-id is required");
4004 return error_mark_node;
4008 error ("parentheses around %qE cannot be used to form a"
4009 " pointer-to-member-function",
4011 PTRMEM_OK_P (xarg) = 1;
4015 if (TREE_CODE (xarg) == OFFSET_REF)
4017 ptrmem = PTRMEM_OK_P (xarg);
4019 if (!ptrmem && !flag_ms_extensions
4020 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
4022 /* A single non-static member, make sure we don't allow a
4023 pointer-to-member. */
4024 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
4025 TREE_OPERAND (xarg, 0),
4026 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
4027 PTRMEM_OK_P (xarg) = ptrmem;
4030 else if (TREE_CODE (xarg) == TARGET_EXPR)
4031 warning (0, "taking address of temporary");
4032 exp = build_unary_op (ADDR_EXPR, xarg, 0);
4035 if (processing_template_decl && exp != error_mark_node)
4036 exp = build_min_non_dep (code, exp, orig_expr,
4037 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
4038 if (TREE_CODE (exp) == ADDR_EXPR)
4039 PTRMEM_OK_P (exp) = ptrmem;
4043 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
4044 constants, where a null value is represented by an INTEGER_CST of
4048 cp_truthvalue_conversion (tree expr)
4050 tree type = TREE_TYPE (expr);
4051 if (TYPE_PTRMEM_P (type))
4052 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
4054 return c_common_truthvalue_conversion (expr);
4057 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
4060 condition_conversion (tree expr)
4063 if (processing_template_decl)
4065 t = perform_implicit_conversion (boolean_type_node, expr);
4066 t = fold_build_cleanup_point_expr (boolean_type_node, t);
4070 /* Return an ADDR_EXPR giving the address of T. This function
4071 attempts no optimizations or simplifications; it is a low-level
4075 build_address (tree t)
4079 if (error_operand_p (t) || !cxx_mark_addressable (t))
4080 return error_mark_node;
4082 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4087 /* Return a NOP_EXPR converting EXPR to TYPE. */
4090 build_nop (tree type, tree expr)
4092 if (type == error_mark_node || error_operand_p (expr))
4094 return build1 (NOP_EXPR, type, expr);
4097 /* C++: Must handle pointers to members.
4099 Perhaps type instantiation should be extended to handle conversion
4100 from aggregates to types we don't yet know we want? (Or are those
4101 cases typically errors which should be reported?)
4103 NOCONVERT nonzero suppresses the default promotions
4104 (such as from short to int). */
4107 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4109 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4112 const char *errstring = NULL;
4114 const char *invalid_op_diag;
4116 if (arg == error_mark_node)
4117 return error_mark_node;
4119 if ((invalid_op_diag
4120 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4125 error (invalid_op_diag);
4126 return error_mark_node;
4131 case UNARY_PLUS_EXPR:
4134 int flags = WANT_ARITH | WANT_ENUM;
4135 /* Unary plus (but not unary minus) is allowed on pointers. */
4136 if (code == UNARY_PLUS_EXPR)
4137 flags |= WANT_POINTER;
4138 arg = build_expr_type_conversion (flags, arg, true);
4140 errstring = (code == NEGATE_EXPR
4141 ? "wrong type argument to unary minus"
4142 : "wrong type argument to unary plus");
4145 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4146 arg = perform_integral_promotions (arg);
4148 /* Make sure the result is not an lvalue: a unary plus or minus
4149 expression is always a rvalue. */
4156 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4160 arg = default_conversion (arg);
4162 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4165 errstring = "wrong type argument to bit-complement";
4166 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4167 arg = perform_integral_promotions (arg);
4171 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4172 errstring = "wrong type argument to abs";
4173 else if (!noconvert)
4174 arg = default_conversion (arg);
4178 /* Conjugating a real value is a no-op, but allow it anyway. */
4179 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4180 errstring = "wrong type argument to conjugation";
4181 else if (!noconvert)
4182 arg = default_conversion (arg);
4185 case TRUTH_NOT_EXPR:
4186 arg = perform_implicit_conversion (boolean_type_node, arg);
4187 val = invert_truthvalue (arg);
4188 if (arg != error_mark_node)
4190 errstring = "in argument to unary !";
4197 if (TREE_CODE (arg) == COMPLEX_CST)
4198 return TREE_REALPART (arg);
4199 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4201 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4202 return fold_if_not_in_template (arg);
4208 if (TREE_CODE (arg) == COMPLEX_CST)
4209 return TREE_IMAGPART (arg);
4210 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4212 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4213 return fold_if_not_in_template (arg);
4216 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4218 case PREINCREMENT_EXPR:
4219 case POSTINCREMENT_EXPR:
4220 case PREDECREMENT_EXPR:
4221 case POSTDECREMENT_EXPR:
4222 /* Handle complex lvalues (when permitted)
4223 by reduction to simpler cases. */
4225 val = unary_complex_lvalue (code, arg);
4229 /* Increment or decrement the real part of the value,
4230 and don't change the imaginary part. */
4231 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4235 arg = stabilize_reference (arg);
4236 real = build_unary_op (REALPART_EXPR, arg, 1);
4237 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4238 real = build_unary_op (code, real, 1);
4239 if (real == error_mark_node || imag == error_mark_node)
4240 return error_mark_node;
4241 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4245 /* Report invalid types. */
4247 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4250 if (code == PREINCREMENT_EXPR)
4251 errstring ="no pre-increment operator for type";
4252 else if (code == POSTINCREMENT_EXPR)
4253 errstring ="no post-increment operator for type";
4254 else if (code == PREDECREMENT_EXPR)
4255 errstring ="no pre-decrement operator for type";
4257 errstring ="no post-decrement operator for type";
4260 else if (arg == error_mark_node)
4261 return error_mark_node;
4263 /* Report something read-only. */
4265 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4266 || TREE_READONLY (arg))
4267 readonly_error (arg, ((code == PREINCREMENT_EXPR
4268 || code == POSTINCREMENT_EXPR)
4269 ? "increment" : "decrement"));
4274 tree result_type = TREE_TYPE (arg);
4276 declared_type = unlowered_expr_type (arg);
4278 arg = get_unwidened (arg, 0);
4279 argtype = TREE_TYPE (arg);
4281 /* ARM $5.2.5 last annotation says this should be forbidden. */
4282 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4283 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4284 ? G_("ISO C++ forbids incrementing an enum")
4285 : G_("ISO C++ forbids decrementing an enum"));
4287 /* Compute the increment. */
4289 if (TREE_CODE (argtype) == POINTER_TYPE)
4291 tree type = complete_type (TREE_TYPE (argtype));
4293 if (!COMPLETE_OR_VOID_TYPE_P (type))
4294 error (((code == PREINCREMENT_EXPR
4295 || code == POSTINCREMENT_EXPR))
4296 ? G_("cannot increment a pointer to incomplete type %qT")
4297 : G_("cannot decrement a pointer to incomplete type %qT"),
4298 TREE_TYPE (argtype));
4299 else if ((pedantic || warn_pointer_arith)
4300 && !TYPE_PTROB_P (argtype))
4301 pedwarn ((code == PREINCREMENT_EXPR
4302 || code == POSTINCREMENT_EXPR)
4303 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4304 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4306 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4309 inc = integer_one_node;
4311 inc = cp_convert (argtype, inc);
4313 /* Complain about anything else that is not a true lvalue. */
4314 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4315 || code == POSTINCREMENT_EXPR)
4316 ? lv_increment : lv_decrement)))
4317 return error_mark_node;
4319 /* Forbid using -- on `bool'. */
4320 if (same_type_p (declared_type, boolean_type_node))
4322 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4324 error ("invalid use of Boolean expression as operand "
4325 "to %<operator--%>");
4326 return error_mark_node;
4328 val = boolean_increment (code, arg);
4331 val = build2 (code, TREE_TYPE (arg), arg, inc);
4333 TREE_SIDE_EFFECTS (val) = 1;
4334 return cp_convert (result_type, val);
4338 /* Note that this operation never does default_conversion
4339 regardless of NOCONVERT. */
4341 argtype = lvalue_type (arg);
4343 if (TREE_CODE (arg) == OFFSET_REF)
4346 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4348 tree type = build_pointer_type (TREE_TYPE (argtype));
4349 arg = build1 (CONVERT_EXPR, type, arg);
4352 else if (pedantic && DECL_MAIN_P (arg))
4354 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4356 /* Let &* cancel out to simplify resulting code. */
4357 if (TREE_CODE (arg) == INDIRECT_REF)
4359 /* We don't need to have `current_class_ptr' wrapped in a
4360 NON_LVALUE_EXPR node. */
4361 if (arg == current_class_ref)
4362 return current_class_ptr;
4364 arg = TREE_OPERAND (arg, 0);
4365 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4367 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4368 arg = build1 (CONVERT_EXPR, type, arg);
4371 /* Don't let this be an lvalue. */
4376 /* Uninstantiated types are all functions. Taking the
4377 address of a function is a no-op, so just return the
4380 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4381 || !IDENTIFIER_OPNAME_P (arg));
4383 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4384 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4386 /* They're trying to take the address of a unique non-static
4387 member function. This is ill-formed (except in MS-land),
4388 but let's try to DTRT.
4389 Note: We only handle unique functions here because we don't
4390 want to complain if there's a static overload; non-unique
4391 cases will be handled by instantiate_type. But we need to
4392 handle this case here to allow casts on the resulting PMF.
4393 We could defer this in non-MS mode, but it's easier to give
4394 a useful error here. */
4396 /* Inside constant member functions, the `this' pointer
4397 contains an extra const qualifier. TYPE_MAIN_VARIANT
4398 is used here to remove this const from the diagnostics
4399 and the created OFFSET_REF. */
4400 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4401 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4404 if (! flag_ms_extensions)
4406 tree name = DECL_NAME (fn);
4407 if (current_class_type
4408 && TREE_OPERAND (arg, 0) == current_class_ref)
4409 /* An expression like &memfn. */
4410 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4411 " or parenthesized non-static member function to form"
4412 " a pointer to member function. Say %<&%T::%D%>",
4415 pedwarn ("ISO C++ forbids taking the address of a bound member"
4416 " function to form a pointer to member function."
4420 arg = build_offset_ref (base, fn, /*address_p=*/true);
4424 if (type_unknown_p (arg))
4425 return build1 (ADDR_EXPR, unknown_type_node, arg);
4427 /* Handle complex lvalues (when permitted)
4428 by reduction to simpler cases. */
4429 val = unary_complex_lvalue (code, arg);
4433 switch (TREE_CODE (arg))
4438 case FIX_TRUNC_EXPR:
4439 if (! lvalue_p (arg) && pedantic)
4440 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4444 arg = BASELINK_FUNCTIONS (arg);
4448 arg = OVL_CURRENT (arg);
4452 /* Turn a reference to a non-static data member into a
4453 pointer-to-member. */
4458 if (!PTRMEM_OK_P (arg))
4459 return build_unary_op (code, arg, 0);
4461 t = TREE_OPERAND (arg, 1);
4462 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4464 error ("cannot create pointer to reference member %qD", t);
4465 return error_mark_node;
4468 type = build_ptrmem_type (context_for_name_lookup (t),
4470 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4478 /* Anything not already handled and not a true memory reference
4480 if (TREE_CODE (argtype) != FUNCTION_TYPE
4481 && TREE_CODE (argtype) != METHOD_TYPE
4482 && TREE_CODE (arg) != OFFSET_REF
4483 && !lvalue_or_else (arg, lv_addressof))
4484 return error_mark_node;
4486 if (argtype != error_mark_node)
4487 argtype = build_pointer_type (argtype);
4489 /* In a template, we are processing a non-dependent expression
4490 so we can just form an ADDR_EXPR with the correct type. */
4491 if (processing_template_decl)
4493 val = build_address (arg);
4494 if (TREE_CODE (arg) == OFFSET_REF)
4495 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4499 if (TREE_CODE (arg) != COMPONENT_REF)
4501 val = build_address (arg);
4502 if (TREE_CODE (arg) == OFFSET_REF)
4503 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4505 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4507 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4509 /* We can only get here with a single static member
4511 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4512 && DECL_STATIC_FUNCTION_P (fn));
4514 val = build_address (fn);
4515 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4516 /* Do not lose object's side effects. */
4517 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4518 TREE_OPERAND (arg, 0), val);
4520 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4522 error ("attempt to take address of bit-field structure member %qD",
4523 TREE_OPERAND (arg, 1));
4524 return error_mark_node;
4528 tree object = TREE_OPERAND (arg, 0);
4529 tree field = TREE_OPERAND (arg, 1);
4530 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4531 (TREE_TYPE (object), decl_type_context (field)));
4532 val = build_address (arg);
4535 if (TREE_CODE (argtype) == POINTER_TYPE
4536 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4538 build_ptrmemfunc_type (argtype);
4539 val = build_ptrmemfunc (argtype, val, 0,
4540 /*c_cast_p=*/false);
4552 argtype = TREE_TYPE (arg);
4553 return fold_if_not_in_template (build1 (code, argtype, arg));
4556 error ("%s", errstring);
4557 return error_mark_node;
4560 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4561 for certain kinds of expressions which are not really lvalues
4562 but which we can accept as lvalues.
4564 If ARG is not a kind of expression we can handle, return
4568 unary_complex_lvalue (enum tree_code code, tree arg)
4570 /* Inside a template, making these kinds of adjustments is
4571 pointless; we are only concerned with the type of the
4573 if (processing_template_decl)
4576 /* Handle (a, b) used as an "lvalue". */
4577 if (TREE_CODE (arg) == COMPOUND_EXPR)
4579 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4580 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4581 TREE_OPERAND (arg, 0), real_result);
4584 /* Handle (a ? b : c) used as an "lvalue". */
4585 if (TREE_CODE (arg) == COND_EXPR
4586 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4587 return rationalize_conditional_expr (code, arg);
4589 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4590 if (TREE_CODE (arg) == MODIFY_EXPR
4591 || TREE_CODE (arg) == PREINCREMENT_EXPR
4592 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4594 tree lvalue = TREE_OPERAND (arg, 0);
4595 if (TREE_SIDE_EFFECTS (lvalue))
4597 lvalue = stabilize_reference (lvalue);
4598 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4599 lvalue, TREE_OPERAND (arg, 1));
4601 return unary_complex_lvalue
4602 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4605 if (code != ADDR_EXPR)
4608 /* Handle (a = b) used as an "lvalue" for `&'. */
4609 if (TREE_CODE (arg) == MODIFY_EXPR
4610 || TREE_CODE (arg) == INIT_EXPR)
4612 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4613 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4615 TREE_NO_WARNING (arg) = 1;
4619 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4620 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4621 || TREE_CODE (arg) == OFFSET_REF)
4624 /* We permit compiler to make function calls returning
4625 objects of aggregate type look like lvalues. */
4629 if (TREE_CODE (targ) == SAVE_EXPR)
4630 targ = TREE_OPERAND (targ, 0);
4632 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4634 if (TREE_CODE (arg) == SAVE_EXPR)
4637 targ = build_cplus_new (TREE_TYPE (arg), arg);
4638 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4641 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4642 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4643 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4646 /* Don't let anything else be handled specially. */
4650 /* Mark EXP saying that we need to be able to take the
4651 address of it; it should not be allocated in a register.
4652 Value is true if successful.
4654 C++: we do not allow `current_class_ptr' to be addressable. */
4657 cxx_mark_addressable (tree exp)
4662 switch (TREE_CODE (x))
4669 x = TREE_OPERAND (x, 0);
4673 if (x == current_class_ptr)
4675 error ("cannot take the address of %<this%>, which is an rvalue expression");
4676 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4682 /* Caller should not be trying to mark initialized
4683 constant fields addressable. */
4684 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4685 || DECL_IN_AGGR_P (x) == 0
4687 || DECL_EXTERNAL (x));
4692 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4693 && !DECL_ARTIFICIAL (x))
4695 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4698 ("address of explicit register variable %qD requested", x);
4701 else if (extra_warnings)
4703 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4705 TREE_ADDRESSABLE (x) = 1;
4709 TREE_ADDRESSABLE (x) = 1;
4713 TREE_ADDRESSABLE (x) = 1;
4717 TREE_ADDRESSABLE (x) = 1;
4718 cxx_mark_addressable (TREE_OPERAND (x, 0));
4726 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4729 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4731 tree orig_ifexp = ifexp;
4732 tree orig_op1 = op1;
4733 tree orig_op2 = op2;
4736 if (processing_template_decl)
4738 /* The standard says that the expression is type-dependent if
4739 IFEXP is type-dependent, even though the eventual type of the
4740 expression doesn't dependent on IFEXP. */
4741 if (type_dependent_expression_p (ifexp)
4742 /* As a GNU extension, the middle operand may be omitted. */
4743 || (op1 && type_dependent_expression_p (op1))
4744 || type_dependent_expression_p (op2))
4745 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4746 ifexp = build_non_dependent_expr (ifexp);
4748 op1 = build_non_dependent_expr (op1);
4749 op2 = build_non_dependent_expr (op2);
4752 expr = build_conditional_expr (ifexp, op1, op2);
4753 if (processing_template_decl && expr != error_mark_node)
4754 return build_min_non_dep (COND_EXPR, expr,
4755 orig_ifexp, orig_op1, orig_op2);
4759 /* Given a list of expressions, return a compound expression
4760 that performs them all and returns the value of the last of them. */
4762 tree build_x_compound_expr_from_list (tree list, const char *msg)
4764 tree expr = TREE_VALUE (list);
4766 if (TREE_CHAIN (list))
4769 pedwarn ("%s expression list treated as compound expression", msg);
4771 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4772 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4778 /* Handle overloading of the ',' operator when needed. */
4781 build_x_compound_expr (tree op1, tree op2)
4784 tree orig_op1 = op1;
4785 tree orig_op2 = op2;
4787 if (processing_template_decl)
4789 if (type_dependent_expression_p (op1)
4790 || type_dependent_expression_p (op2))
4791 return build_min_nt (COMPOUND_EXPR, op1, op2);
4792 op1 = build_non_dependent_expr (op1);
4793 op2 = build_non_dependent_expr (op2);
4796 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4797 /*overloaded_p=*/NULL);
4799 result = build_compound_expr (op1, op2);
4801 if (processing_template_decl && result != error_mark_node)
4802 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4807 /* Build a compound expression. */
4810 build_compound_expr (tree lhs, tree rhs)
4812 lhs = convert_to_void (lhs, "left-hand operand of comma");
4814 if (lhs == error_mark_node || rhs == error_mark_node)
4815 return error_mark_node;
4817 if (TREE_CODE (rhs) == TARGET_EXPR)
4819 /* If the rhs is a TARGET_EXPR, then build the compound
4820 expression inside the target_expr's initializer. This
4821 helps the compiler to eliminate unnecessary temporaries. */
4822 tree init = TREE_OPERAND (rhs, 1);
4824 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4825 TREE_OPERAND (rhs, 1) = init;
4830 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4833 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4834 casts away constness. DIAG_FN gives the function to call if we
4835 need to issue a diagnostic; if it is NULL, no diagnostic will be
4836 issued. DESCRIPTION explains what operation is taking place. */
4839 check_for_casting_away_constness (tree src_type, tree dest_type,
4840 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4841 const char *description)
4843 if (diag_fn && casts_away_constness (src_type, dest_type))
4844 diag_fn ("%s from type %qT to type %qT casts away constness",
4845 description, src_type, dest_type);
4848 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4849 (another pointer-to-member type in the same hierarchy) and return
4850 the converted expression. If ALLOW_INVERSE_P is permitted, a
4851 pointer-to-derived may be converted to pointer-to-base; otherwise,
4852 only the other direction is permitted. If C_CAST_P is true, this
4853 conversion is taking place as part of a C-style cast. */
4856 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4859 if (TYPE_PTRMEM_P (type))
4863 if (TREE_CODE (expr) == PTRMEM_CST)
4864 expr = cplus_expand_constant (expr);
4865 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4866 TYPE_PTRMEM_CLASS_TYPE (type),
4869 if (!integer_zerop (delta))
4871 tree cond, op1, op2;
4873 cond = cp_build_binary_op (EQ_EXPR,
4875 build_int_cst (TREE_TYPE (expr), -1));
4876 op1 = build_nop (ptrdiff_type_node, expr);
4877 op2 = cp_build_binary_op (PLUS_EXPR, op1, delta);
4879 expr = fold_build3 (COND_EXPR, ptrdiff_type_node, cond, op1, op2);
4883 return build_nop (type, expr);
4886 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4887 allow_inverse_p, c_cast_p);
4890 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4891 a version of EXPR that has TREE_OVERFLOW set if it is set in ORIG.
4892 Otherwise, return EXPR unchanged. */
4895 ignore_overflows (tree expr, tree orig)
4897 if (TREE_CODE (expr) == INTEGER_CST
4898 && CONSTANT_CLASS_P (orig)
4899 && TREE_CODE (orig) != STRING_CST
4900 && TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig))
4902 if (!TREE_OVERFLOW (orig))
4903 /* Ensure constant sharing. */
4904 expr = build_int_cst_wide (TREE_TYPE (expr),
4905 TREE_INT_CST_LOW (expr),
4906 TREE_INT_CST_HIGH (expr));
4909 /* Avoid clobbering a shared constant. */
4910 expr = copy_node (expr);
4911 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4917 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4918 this static_cast is being attempted as one of the possible casts
4919 allowed by a C-style cast. (In that case, accessibility of base
4920 classes is not considered, and it is OK to cast away
4921 constness.) Return the result of the cast. *VALID_P is set to
4922 indicate whether or not the cast was valid. */
4925 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4931 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4934 /* Assume the cast is valid. */
4937 intype = TREE_TYPE (expr);
4939 /* Save casted types in the function's used types hash table. */
4940 used_types_insert (type);
4942 /* Determine what to do when casting away constness. */
4945 /* C-style casts are allowed to cast away constness. With
4946 WARN_CAST_QUAL, we still want to issue a warning. */
4947 diag_fn = warn_cast_qual ? warning0 : NULL;
4952 /* A static_cast may not cast away constness. */
4954 desc = "static_cast";
4957 /* [expr.static.cast]
4959 An lvalue of type "cv1 B", where B is a class type, can be cast
4960 to type "reference to cv2 D", where D is a class derived (clause
4961 _class.derived_) from B, if a valid standard conversion from
4962 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4963 same cv-qualification as, or greater cv-qualification than, cv1,
4964 and B is not a virtual base class of D. */
4965 /* We check this case before checking the validity of "TYPE t =
4966 EXPR;" below because for this case:
4969 struct D : public B { D(const B&); };
4971 void f() { static_cast<const D&>(b); }
4973 we want to avoid constructing a new D. The standard is not
4974 completely clear about this issue, but our interpretation is
4975 consistent with other compilers. */
4976 if (TREE_CODE (type) == REFERENCE_TYPE
4977 && CLASS_TYPE_P (TREE_TYPE (type))
4978 && CLASS_TYPE_P (intype)
4979 && real_lvalue_p (expr)
4980 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4981 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4982 build_pointer_type (TYPE_MAIN_VARIANT
4983 (TREE_TYPE (type))))
4985 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4989 /* There is a standard conversion from "D*" to "B*" even if "B"
4990 is ambiguous or inaccessible. If this is really a
4991 static_cast, then we check both for inaccessibility and
4992 ambiguity. However, if this is a static_cast being performed
4993 because the user wrote a C-style cast, then accessibility is
4995 base = lookup_base (TREE_TYPE (type), intype,
4996 c_cast_p ? ba_unique : ba_check,
4999 /* Convert from "B*" to "D*". This function will check that "B"
5000 is not a virtual base of "D". */
5001 expr = build_base_path (MINUS_EXPR, build_address (expr),
5002 base, /*nonnull=*/false);
5003 /* Convert the pointer to a reference -- but then remember that
5004 there are no expressions with reference type in C++. */
5005 return convert_from_reference (build_nop (type, expr));
5010 /* [expr.static.cast]
5012 An expression e can be explicitly converted to a type T using a
5013 static_cast of the form static_cast<T>(e) if the declaration T
5014 t(e);" is well-formed, for some invented temporary variable
5016 result = perform_direct_initialization_if_possible (type, expr,
5020 result = convert_from_reference (result);
5022 /* Ignore any integer overflow caused by the cast. */
5023 result = ignore_overflows (result, orig);
5025 /* [expr.static.cast]
5027 If T is a reference type, the result is an lvalue; otherwise,
5028 the result is an rvalue. */
5029 if (TREE_CODE (type) != REFERENCE_TYPE)
5030 result = rvalue (result);
5034 /* [expr.static.cast]
5036 Any expression can be explicitly converted to type cv void. */
5037 if (TREE_CODE (type) == VOID_TYPE)
5038 return convert_to_void (expr, /*implicit=*/NULL);
5040 /* [expr.static.cast]
5042 The inverse of any standard conversion sequence (clause _conv_),
5043 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
5044 (_conv.array_), function-to-pointer (_conv.func_), and boolean
5045 (_conv.bool_) conversions, can be performed explicitly using
5046 static_cast subject to the restriction that the explicit
5047 conversion does not cast away constness (_expr.const.cast_), and
5048 the following additional rules for specific cases: */
5049 /* For reference, the conversions not excluded are: integral
5050 promotions, floating point promotion, integral conversions,
5051 floating point conversions, floating-integral conversions,
5052 pointer conversions, and pointer to member conversions. */
5055 A value of integral _or enumeration_ type can be explicitly
5056 converted to an enumeration type. */
5057 /* The effect of all that is that any conversion between any two
5058 types which are integral, floating, or enumeration types can be
5060 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5061 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5063 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5065 /* Ignore any integer overflow caused by the cast. */
5066 expr = ignore_overflows (expr, orig);
5070 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5071 && CLASS_TYPE_P (TREE_TYPE (type))
5072 && CLASS_TYPE_P (TREE_TYPE (intype))
5073 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5074 (TREE_TYPE (intype))),
5075 build_pointer_type (TYPE_MAIN_VARIANT
5076 (TREE_TYPE (type)))))
5081 check_for_casting_away_constness (intype, type, diag_fn, desc);
5082 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5083 c_cast_p ? ba_unique : ba_check,
5085 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5088 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5089 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5096 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5097 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5099 if (TYPE_PTRMEM_P (type))
5101 t1 = (build_ptrmem_type
5103 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5104 t2 = (build_ptrmem_type
5106 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5113 if (can_convert (t1, t2) || can_convert (t2, t1))
5116 check_for_casting_away_constness (intype, type, diag_fn,
5118 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5123 /* [expr.static.cast]
5125 An rvalue of type "pointer to cv void" can be explicitly
5126 converted to a pointer to object type. A value of type pointer
5127 to object converted to "pointer to cv void" and back to the
5128 original pointer type will have its original value. */
5129 if (TREE_CODE (intype) == POINTER_TYPE
5130 && VOID_TYPE_P (TREE_TYPE (intype))
5131 && TYPE_PTROB_P (type))
5134 check_for_casting_away_constness (intype, type, diag_fn, desc);
5135 return build_nop (type, expr);
5139 return error_mark_node;
5142 /* Return an expression representing static_cast<TYPE>(EXPR). */
5145 build_static_cast (tree type, tree expr)
5150 if (type == error_mark_node || expr == error_mark_node)
5151 return error_mark_node;
5153 if (processing_template_decl)
5155 expr = build_min (STATIC_CAST_EXPR, type, expr);
5156 /* We don't know if it will or will not have side effects. */
5157 TREE_SIDE_EFFECTS (expr) = 1;
5158 return convert_from_reference (expr);
5161 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5162 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5163 if (TREE_CODE (type) != REFERENCE_TYPE
5164 && TREE_CODE (expr) == NOP_EXPR
5165 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5166 expr = TREE_OPERAND (expr, 0);
5168 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5172 error ("invalid static_cast from type %qT to type %qT",
5173 TREE_TYPE (expr), type);
5174 return error_mark_node;
5177 /* EXPR is an expression with member function or pointer-to-member
5178 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5179 not permitted by ISO C++, but we accept it in some modes. If we
5180 are not in one of those modes, issue a diagnostic. Return the
5181 converted expression. */
5184 convert_member_func_to_ptr (tree type, tree expr)
5189 intype = TREE_TYPE (expr);
5190 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5191 || TREE_CODE (intype) == METHOD_TYPE);
5193 if (pedantic || warn_pmf2ptr)
5194 pedwarn ("converting from %qT to %qT", intype, type);
5196 if (TREE_CODE (intype) == METHOD_TYPE)
5197 expr = build_addr_func (expr);
5198 else if (TREE_CODE (expr) == PTRMEM_CST)
5199 expr = build_address (PTRMEM_CST_MEMBER (expr));
5202 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5203 decl = build_address (decl);
5204 expr = get_member_function_from_ptrfunc (&decl, expr);
5207 return build_nop (type, expr);
5210 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5211 If C_CAST_P is true, this reinterpret cast is being done as part of
5212 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5213 indicate whether or not reinterpret_cast was valid. */
5216 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5221 /* Assume the cast is invalid. */
5225 if (type == error_mark_node || error_operand_p (expr))
5226 return error_mark_node;
5228 intype = TREE_TYPE (expr);
5230 /* Save casted types in the function's used types hash table. */
5231 used_types_insert (type);
5233 /* [expr.reinterpret.cast]
5234 An lvalue expression of type T1 can be cast to the type
5235 "reference to T2" if an expression of type "pointer to T1" can be
5236 explicitly converted to the type "pointer to T2" using a
5237 reinterpret_cast. */
5238 if (TREE_CODE (type) == REFERENCE_TYPE)
5240 if (! real_lvalue_p (expr))
5242 error ("invalid cast of an rvalue expression of type "
5245 return error_mark_node;
5248 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5249 "B" are related class types; the reinterpret_cast does not
5250 adjust the pointer. */
5251 if (TYPE_PTR_P (intype)
5252 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5253 COMPARE_BASE | COMPARE_DERIVED)))
5254 warning (0, "casting %qT to %qT does not dereference pointer",
5257 expr = build_unary_op (ADDR_EXPR, expr, 0);
5258 if (expr != error_mark_node)
5259 expr = build_reinterpret_cast_1
5260 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5262 if (expr != error_mark_node)
5263 expr = build_indirect_ref (expr, 0);
5267 /* As a G++ extension, we consider conversions from member
5268 functions, and pointers to member functions to
5269 pointer-to-function and pointer-to-void types. If
5270 -Wno-pmf-conversions has not been specified,
5271 convert_member_func_to_ptr will issue an error message. */
5272 if ((TYPE_PTRMEMFUNC_P (intype)
5273 || TREE_CODE (intype) == METHOD_TYPE)
5274 && TYPE_PTR_P (type)
5275 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5276 || VOID_TYPE_P (TREE_TYPE (type))))
5277 return convert_member_func_to_ptr (type, expr);
5279 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5280 array-to-pointer, and function-to-pointer conversions are
5282 expr = decay_conversion (expr);
5284 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5285 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5286 if (TREE_CODE (expr) == NOP_EXPR
5287 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5288 expr = TREE_OPERAND (expr, 0);
5290 if (error_operand_p (expr))
5291 return error_mark_node;
5293 intype = TREE_TYPE (expr);
5295 /* [expr.reinterpret.cast]
5296 A pointer can be converted to any integral type large enough to
5298 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5300 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5301 pedwarn ("cast from %qT to %qT loses precision",
5304 /* [expr.reinterpret.cast]
5305 A value of integral or enumeration type can be explicitly
5306 converted to a pointer. */
5307 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5310 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5311 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5312 return fold_if_not_in_template (build_nop (type, expr));
5313 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5314 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5319 check_for_casting_away_constness (intype, type, error,
5320 "reinterpret_cast");
5321 /* Warn about possible alignment problems. */
5322 if (STRICT_ALIGNMENT && warn_cast_align
5323 && !VOID_TYPE_P (type)
5324 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5325 && COMPLETE_TYPE_P (TREE_TYPE (type))
5326 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5327 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5328 warning (0, "cast from %qT to %qT increases required alignment of "
5332 /* We need to strip nops here, because the front end likes to
5333 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5335 if (warn_strict_aliasing <= 2)
5336 strict_aliasing_warning (intype, type, sexpr);
5338 return fold_if_not_in_template (build_nop (type, expr));
5340 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5341 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5344 /* Only issue a warning, as we have always supported this
5345 where possible, and it is necessary in some cases. DR 195
5346 addresses this issue, but as of 2004/10/26 is still in
5348 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5349 return fold_if_not_in_template (build_nop (type, expr));
5351 else if (TREE_CODE (type) == VECTOR_TYPE)
5352 return fold_if_not_in_template (convert_to_vector (type, expr));
5353 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5354 return fold_if_not_in_template (convert_to_integer (type, expr));
5359 error ("invalid cast from type %qT to type %qT", intype, type);
5360 return error_mark_node;
5363 return cp_convert (type, expr);
5367 build_reinterpret_cast (tree type, tree expr)
5369 if (type == error_mark_node || expr == error_mark_node)
5370 return error_mark_node;
5372 if (processing_template_decl)
5374 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5376 if (!TREE_SIDE_EFFECTS (t)
5377 && type_dependent_expression_p (expr))
5378 /* There might turn out to be side effects inside expr. */
5379 TREE_SIDE_EFFECTS (t) = 1;
5380 return convert_from_reference (t);
5383 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5387 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5388 return an appropriate expression. Otherwise, return
5389 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5390 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5391 performing a C-style cast, its value upon return will indicate
5392 whether or not the conversion succeeded. */
5395 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5399 tree reference_type;
5401 /* Callers are responsible for handling error_mark_node as a
5402 destination type. */
5403 gcc_assert (dst_type != error_mark_node);
5404 /* In a template, callers should be building syntactic
5405 representations of casts, not using this machinery. */
5406 gcc_assert (!processing_template_decl);
5408 /* Assume the conversion is invalid. */
5412 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5415 error ("invalid use of const_cast with type %qT, "
5416 "which is not a pointer, "
5417 "reference, nor a pointer-to-data-member type", dst_type);
5418 return error_mark_node;
5421 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5424 error ("invalid use of const_cast with type %qT, which is a pointer "
5425 "or reference to a function type", dst_type);
5426 return error_mark_node;
5429 /* Save casted types in the function's used types hash table. */
5430 used_types_insert (dst_type);
5432 src_type = TREE_TYPE (expr);
5433 /* Expressions do not really have reference types. */
5434 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5435 src_type = TREE_TYPE (src_type);
5437 /* [expr.const.cast]
5439 An lvalue of type T1 can be explicitly converted to an lvalue of
5440 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5441 types) if a pointer to T1 can be explicitly converted to the type
5442 pointer to T2 using a const_cast. */
5443 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5445 reference_type = dst_type;
5446 if (! real_lvalue_p (expr))
5449 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5450 src_type, dst_type);
5451 return error_mark_node;
5453 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5454 src_type = build_pointer_type (src_type);
5458 reference_type = NULL_TREE;
5459 /* If the destination type is not a reference type, the
5460 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5461 conversions are performed. */
5462 src_type = type_decays_to (src_type);
5463 if (src_type == error_mark_node)
5464 return error_mark_node;
5467 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5468 && comp_ptr_ttypes_const (dst_type, src_type))
5473 /* This cast is actually a C-style cast. Issue a warning if
5474 the user is making a potentially unsafe cast. */
5476 check_for_casting_away_constness (src_type, dst_type,
5482 expr = build_unary_op (ADDR_EXPR, expr, 0);
5483 expr = build_nop (reference_type, expr);
5484 return convert_from_reference (expr);
5488 expr = decay_conversion (expr);
5489 /* build_c_cast puts on a NOP_EXPR to make the result not an
5490 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5491 non-lvalue context. */
5492 if (TREE_CODE (expr) == NOP_EXPR
5493 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5494 expr = TREE_OPERAND (expr, 0);
5495 return build_nop (dst_type, expr);
5500 error ("invalid const_cast from type %qT to type %qT",
5501 src_type, dst_type);
5502 return error_mark_node;
5506 build_const_cast (tree type, tree expr)
5508 if (type == error_mark_node || error_operand_p (expr))
5509 return error_mark_node;
5511 if (processing_template_decl)
5513 tree t = build_min (CONST_CAST_EXPR, type, expr);
5515 if (!TREE_SIDE_EFFECTS (t)
5516 && type_dependent_expression_p (expr))
5517 /* There might turn out to be side effects inside expr. */
5518 TREE_SIDE_EFFECTS (t) = 1;
5519 return convert_from_reference (t);
5522 return build_const_cast_1 (type, expr, /*complain=*/true,
5526 /* Build an expression representing an explicit C-style cast to type
5527 TYPE of expression EXPR. */
5530 build_c_cast (tree type, tree expr)
5536 if (type == error_mark_node || error_operand_p (expr))
5537 return error_mark_node;
5539 if (processing_template_decl)
5541 tree t = build_min (CAST_EXPR, type,
5542 tree_cons (NULL_TREE, value, NULL_TREE));
5543 /* We don't know if it will or will not have side effects. */
5544 TREE_SIDE_EFFECTS (t) = 1;
5545 return convert_from_reference (t);
5548 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5549 'Class') should always be retained, because this information aids
5550 in method lookup. */
5551 if (objc_is_object_ptr (type)
5552 && objc_is_object_ptr (TREE_TYPE (expr)))
5553 return build_nop (type, expr);
5555 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5556 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5557 if (TREE_CODE (type) != REFERENCE_TYPE
5558 && TREE_CODE (value) == NOP_EXPR
5559 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5560 value = TREE_OPERAND (value, 0);
5562 if (TREE_CODE (type) == ARRAY_TYPE)
5564 /* Allow casting from T1* to T2[] because Cfront allows it.
5565 NIHCL uses it. It is not valid ISO C++ however. */
5566 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5568 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5569 type = build_pointer_type (TREE_TYPE (type));
5573 error ("ISO C++ forbids casting to an array type %qT", type);
5574 return error_mark_node;
5578 if (TREE_CODE (type) == FUNCTION_TYPE
5579 || TREE_CODE (type) == METHOD_TYPE)
5581 error ("invalid cast to function type %qT", type);
5582 return error_mark_node;
5585 /* A C-style cast can be a const_cast. */
5586 result = build_const_cast_1 (type, value, /*complain=*/false,
5591 /* Or a static cast. */
5592 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5594 /* Or a reinterpret_cast. */
5596 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5598 /* The static_cast or reinterpret_cast may be followed by a
5601 /* A valid cast may result in errors if, for example, a
5602 conversion to am ambiguous base class is required. */
5603 && !error_operand_p (result))
5607 /* Non-class rvalues always have cv-unqualified type. */
5608 if (!CLASS_TYPE_P (type))
5609 type = TYPE_MAIN_VARIANT (type);
5610 result_type = TREE_TYPE (result);
5611 if (!CLASS_TYPE_P (result_type))
5612 result_type = TYPE_MAIN_VARIANT (result_type);
5613 /* If the type of RESULT does not match TYPE, perform a
5614 const_cast to make it match. If the static_cast or
5615 reinterpret_cast succeeded, we will differ by at most
5616 cv-qualification, so the follow-on const_cast is guaranteed
5618 if (!same_type_p (non_reference (type), non_reference (result_type)))
5620 result = build_const_cast_1 (type, result, false, &valid_p);
5621 gcc_assert (valid_p);
5626 return error_mark_node;
5629 /* Build an assignment expression of lvalue LHS from value RHS.
5630 MODIFYCODE is the code for a binary operator that we use
5631 to combine the old value of LHS with RHS to get the new value.
5632 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5634 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5637 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5641 tree lhstype = TREE_TYPE (lhs);
5642 tree olhstype = lhstype;
5643 tree olhs = NULL_TREE;
5644 bool plain_assign = (modifycode == NOP_EXPR);
5646 /* Avoid duplicate error messages from operands that had errors. */
5647 if (error_operand_p (lhs) || error_operand_p (rhs))
5648 return error_mark_node;
5650 /* Handle control structure constructs used as "lvalues". */
5651 switch (TREE_CODE (lhs))
5653 /* Handle --foo = 5; as these are valid constructs in C++. */
5654 case PREDECREMENT_EXPR:
5655 case PREINCREMENT_EXPR:
5656 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5657 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5658 stabilize_reference (TREE_OPERAND (lhs, 0)),
5659 TREE_OPERAND (lhs, 1));
5660 return build2 (COMPOUND_EXPR, lhstype,
5662 build_modify_expr (TREE_OPERAND (lhs, 0),
5665 /* Handle (a, b) used as an "lvalue". */
5667 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5669 if (newrhs == error_mark_node)
5670 return error_mark_node;
5671 return build2 (COMPOUND_EXPR, lhstype,
5672 TREE_OPERAND (lhs, 0), newrhs);
5675 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5676 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5677 stabilize_reference (TREE_OPERAND (lhs, 0)),
5678 TREE_OPERAND (lhs, 1));
5679 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5680 if (newrhs == error_mark_node)
5681 return error_mark_node;
5682 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5686 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5687 when neither operand has side-effects. */
5688 if (!lvalue_or_else (lhs, lv_assign))
5689 return error_mark_node;
5691 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5692 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5694 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5695 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5697 TREE_OPERAND (lhs, 0),
5698 TREE_OPERAND (lhs, 1)),
5699 TREE_OPERAND (lhs, 0),
5700 TREE_OPERAND (lhs, 1));
5703 /* Handle (a ? b : c) used as an "lvalue". */
5706 /* Produce (a ? (b = rhs) : (c = rhs))
5707 except that the RHS goes through a save-expr
5708 so the code to compute it is only emitted once. */
5710 tree preeval = NULL_TREE;
5712 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5714 error ("void value not ignored as it ought to be");
5715 return error_mark_node;
5718 rhs = stabilize_expr (rhs, &preeval);
5720 /* Check this here to avoid odd errors when trying to convert
5721 a throw to the type of the COND_EXPR. */
5722 if (!lvalue_or_else (lhs, lv_assign))
5723 return error_mark_node;
5725 cond = build_conditional_expr
5726 (TREE_OPERAND (lhs, 0),
5727 build_modify_expr (TREE_OPERAND (lhs, 1),
5729 build_modify_expr (TREE_OPERAND (lhs, 2),
5732 if (cond == error_mark_node)
5734 /* Make sure the code to compute the rhs comes out
5735 before the split. */
5737 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5745 if (modifycode == INIT_EXPR)
5747 if (TREE_CODE (rhs) == CONSTRUCTOR)
5749 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5750 /* Call convert to generate an error; see PR 11063. */
5751 rhs = convert (lhstype, rhs);
5752 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5753 TREE_SIDE_EFFECTS (result) = 1;
5756 else if (! IS_AGGR_TYPE (lhstype))
5757 /* Do the default thing. */;
5760 result = build_special_member_call (lhs, complete_ctor_identifier,
5761 build_tree_list (NULL_TREE, rhs),
5762 lhstype, LOOKUP_NORMAL);
5763 if (result == NULL_TREE)
5764 return error_mark_node;
5770 lhs = require_complete_type (lhs);
5771 if (lhs == error_mark_node)
5772 return error_mark_node;
5774 if (modifycode == NOP_EXPR)
5776 /* `operator=' is not an inheritable operator. */
5777 if (! IS_AGGR_TYPE (lhstype))
5778 /* Do the default thing. */;
5781 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5782 lhs, rhs, make_node (NOP_EXPR),
5783 /*overloaded_p=*/NULL);
5784 if (result == NULL_TREE)
5785 return error_mark_node;
5792 /* A binary op has been requested. Combine the old LHS
5793 value with the RHS producing the value we should actually
5794 store into the LHS. */
5796 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5797 lhs = stabilize_reference (lhs);
5798 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5799 if (newrhs == error_mark_node)
5801 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5802 TREE_TYPE (lhs), TREE_TYPE (rhs));
5803 return error_mark_node;
5806 /* Now it looks like a plain assignment. */
5807 modifycode = NOP_EXPR;
5809 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5810 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5813 /* The left-hand side must be an lvalue. */
5814 if (!lvalue_or_else (lhs, lv_assign))
5815 return error_mark_node;
5817 /* Warn about modifying something that is `const'. Don't warn if
5818 this is initialization. */
5819 if (modifycode != INIT_EXPR
5820 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5821 /* Functions are not modifiable, even though they are
5823 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5824 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5825 /* If it's an aggregate and any field is const, then it is
5826 effectively const. */
5827 || (CLASS_TYPE_P (lhstype)
5828 && C_TYPE_FIELDS_READONLY (lhstype))))
5829 readonly_error (lhs, "assignment");
5831 /* If storing into a structure or union member, it has probably been
5832 given type `int'. Compute the type that would go with the actual
5833 amount of storage the member occupies. */
5835 if (TREE_CODE (lhs) == COMPONENT_REF
5836 && (TREE_CODE (lhstype) == INTEGER_TYPE
5837 || TREE_CODE (lhstype) == REAL_TYPE
5838 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5840 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5842 /* If storing in a field that is in actuality a short or narrower
5843 than one, we must store in the field in its actual type. */
5845 if (lhstype != TREE_TYPE (lhs))
5847 /* Avoid warnings converting integral types back into enums for
5849 if (TREE_CODE (lhstype) == INTEGER_TYPE
5850 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5852 if (TREE_SIDE_EFFECTS (lhs))
5853 lhs = stabilize_reference (lhs);
5856 lhs = copy_node (lhs);
5857 TREE_TYPE (lhs) = lhstype;
5861 /* Convert new value to destination type. */
5863 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5867 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5868 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5870 error ("incompatible types in assignment of %qT to %qT",
5871 TREE_TYPE (rhs), lhstype);
5872 return error_mark_node;
5875 /* Allow array assignment in compiler-generated code. */
5876 if (! DECL_ARTIFICIAL (current_function_decl))
5878 /* This routine is used for both initialization and assignment.
5879 Make sure the diagnostic message differentiates the context. */
5880 if (modifycode == INIT_EXPR)
5881 error ("array used as initializer");
5883 error ("invalid array assignment");
5884 return error_mark_node;
5887 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5888 ? 1 + (modifycode != INIT_EXPR): 0;
5889 return build_vec_init (lhs, NULL_TREE, newrhs,
5890 /*explicit_default_init_p=*/false,
5894 if (modifycode == INIT_EXPR)
5895 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5896 "initialization", NULL_TREE, 0);
5899 /* Avoid warnings on enum bit fields. */
5900 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5901 && TREE_CODE (lhstype) == INTEGER_TYPE)
5903 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5905 newrhs = convert_force (lhstype, newrhs, 0);
5908 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5910 if (TREE_CODE (newrhs) == CALL_EXPR
5911 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5912 newrhs = build_cplus_new (lhstype, newrhs);
5914 /* Can't initialize directly from a TARGET_EXPR, since that would
5915 cause the lhs to be constructed twice, and possibly result in
5916 accidental self-initialization. So we force the TARGET_EXPR to be
5917 expanded without a target. */
5918 if (TREE_CODE (newrhs) == TARGET_EXPR)
5919 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5920 TREE_OPERAND (newrhs, 0));
5923 if (newrhs == error_mark_node)
5924 return error_mark_node;
5926 if (c_dialect_objc () && flag_objc_gc)
5928 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5934 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5935 lhstype, lhs, newrhs);
5937 TREE_SIDE_EFFECTS (result) = 1;
5939 TREE_NO_WARNING (result) = 1;
5941 /* If we got the LHS in a different type for storing in,
5942 convert the result back to the nominal type of LHS
5943 so that the value we return always has the same type
5944 as the LHS argument. */
5946 if (olhstype == TREE_TYPE (result))
5950 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5951 TREE_NO_WARNING (result) = 1;
5954 return convert_for_assignment (olhstype, result, "assignment",
5959 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5961 if (processing_template_decl)
5962 return build_min_nt (MODOP_EXPR, lhs,
5963 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5965 if (modifycode != NOP_EXPR)
5967 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5968 make_node (modifycode),
5969 /*overloaded_p=*/NULL);
5972 TREE_NO_WARNING (rval) = 1;
5976 return build_modify_expr (lhs, modifycode, rhs);
5979 /* Helper function for get_delta_difference which assumes FROM is a base
5980 class of TO. Returns a delta for the conversion of pointer-to-member
5981 of FROM to pointer-to-member of TO. If the conversion is invalid,
5982 returns zero. If FROM is not a base class of TO, returns NULL_TREE.
5983 If C_CAST_P is true, this conversion is taking place as part of a C-style
5987 get_delta_difference_1 (tree from, tree to, bool c_cast_p)
5992 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5993 if (kind == bk_inaccessible || kind == bk_ambig)
5995 error (" in pointer to member function conversion");
5996 return size_zero_node;
6000 if (kind != bk_via_virtual)
6001 return BINFO_OFFSET (binfo);
6003 /* FROM is a virtual base class of TO. Issue an error or warning
6004 depending on whether or not this is a reinterpret cast. */
6006 error ("pointer to member conversion via virtual base %qT",
6007 BINFO_TYPE (binfo_from_vbase (binfo)));
6009 return size_zero_node;
6016 /* Get difference in deltas for different pointer to member function
6017 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
6018 the conversion is invalid, the constant is zero. If
6019 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
6020 If C_CAST_P is true this conversion is taking place as part of a
6023 Note that the naming of FROM and TO is kind of backwards; the return
6024 value is what we add to a TO in order to get a FROM. They are named
6025 this way because we call this function to find out how to convert from
6026 a pointer to member of FROM to a pointer to member of TO. */
6029 get_delta_difference (tree from, tree to,
6030 bool allow_inverse_p,
6035 if (same_type_ignoring_top_level_qualifiers_p (from, to))
6036 /* Pointer to member of incomplete class is permitted*/
6037 result = size_zero_node;
6039 result = get_delta_difference_1 (from, to, c_cast_p);
6043 if (!allow_inverse_p)
6045 error_not_base_type (from, to);
6046 error (" in pointer to member conversion");
6047 result = size_zero_node;
6051 result = get_delta_difference_1 (to, from, c_cast_p);
6054 result = size_diffop (size_zero_node, result);
6057 error_not_base_type (from, to);
6058 error (" in pointer to member conversion");
6059 result = size_zero_node;
6064 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
6068 /* Return a constructor for the pointer-to-member-function TYPE using
6069 the other components as specified. */
6072 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6077 VEC(constructor_elt, gc) *v;
6079 /* Pull the FIELD_DECLs out of the type. */
6080 pfn_field = TYPE_FIELDS (type);
6081 delta_field = TREE_CHAIN (pfn_field);
6083 /* Make sure DELTA has the type we want. */
6084 delta = convert_and_check (delta_type_node, delta);
6086 /* Convert to the correct target type if necessary. */
6087 pfn = fold_convert (TREE_TYPE (pfn_field), pfn);
6089 /* Finish creating the initializer. */
6090 v = VEC_alloc(constructor_elt, gc, 2);
6091 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6092 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6093 u = build_constructor (type, v);
6094 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6095 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6096 TREE_STATIC (u) = (TREE_CONSTANT (u)
6097 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6099 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6104 /* Build a constructor for a pointer to member function. It can be
6105 used to initialize global variables, local variable, or used
6106 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6109 If FORCE is nonzero, then force this conversion, even if
6110 we would rather not do it. Usually set when using an explicit
6111 cast. A C-style cast is being processed iff C_CAST_P is true.
6113 Return error_mark_node, if something goes wrong. */
6116 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6122 if (error_operand_p (pfn))
6123 return error_mark_node;
6125 pfn_type = TREE_TYPE (pfn);
6126 to_type = build_ptrmemfunc_type (type);
6128 /* Handle multiple conversions of pointer to member functions. */
6129 if (TYPE_PTRMEMFUNC_P (pfn_type))
6131 tree delta = NULL_TREE;
6132 tree npfn = NULL_TREE;
6136 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6137 error ("invalid conversion to type %qT from type %qT",
6140 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6141 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6145 /* We don't have to do any conversion to convert a
6146 pointer-to-member to its own type. But, we don't want to
6147 just return a PTRMEM_CST if there's an explicit cast; that
6148 cast should make the expression an invalid template argument. */
6149 if (TREE_CODE (pfn) != PTRMEM_CST)
6151 if (same_type_p (to_type, pfn_type))
6153 else if (integer_zerop (n))
6154 return build_reinterpret_cast (to_type, pfn);
6157 if (TREE_SIDE_EFFECTS (pfn))
6158 pfn = save_expr (pfn);
6160 /* Obtain the function pointer and the current DELTA. */
6161 if (TREE_CODE (pfn) == PTRMEM_CST)
6162 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6165 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6166 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6169 /* Just adjust the DELTA field. */
6170 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6171 (TREE_TYPE (delta), ptrdiff_type_node));
6172 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6173 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6174 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6175 return build_ptrmemfunc1 (to_type, delta, npfn);
6178 /* Handle null pointer to member function conversions. */
6179 if (integer_zerop (pfn))
6181 pfn = build_c_cast (type, integer_zero_node);
6182 return build_ptrmemfunc1 (to_type,
6187 if (type_unknown_p (pfn))
6188 return instantiate_type (type, pfn, tf_warning_or_error);
6190 fn = TREE_OPERAND (pfn, 0);
6191 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6192 /* In a template, we will have preserved the
6194 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6195 return make_ptrmem_cst (to_type, fn);
6198 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6201 ??? There is no consistency as to the types returned for the above
6202 values. Some code acts as if it were a sizetype and some as if it were
6203 integer_type_node. */
6206 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6208 tree type = TREE_TYPE (cst);
6209 tree fn = PTRMEM_CST_MEMBER (cst);
6210 tree ptr_class, fn_class;
6212 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6214 /* The class that the function belongs to. */
6215 fn_class = DECL_CONTEXT (fn);
6217 /* The class that we're creating a pointer to member of. */
6218 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6220 /* First, calculate the adjustment to the function's class. */
6221 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6224 if (!DECL_VIRTUAL_P (fn))
6225 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6228 /* If we're dealing with a virtual function, we have to adjust 'this'
6229 again, to point to the base which provides the vtable entry for
6230 fn; the call will do the opposite adjustment. */
6231 tree orig_class = DECL_CONTEXT (fn);
6232 tree binfo = binfo_or_else (orig_class, fn_class);
6233 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6234 *delta, BINFO_OFFSET (binfo));
6235 *delta = fold_if_not_in_template (*delta);
6237 /* We set PFN to the vtable offset at which the function can be
6238 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6239 case delta is shifted left, and then incremented). */
6240 *pfn = DECL_VINDEX (fn);
6241 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6242 TYPE_SIZE_UNIT (vtable_entry_type));
6243 *pfn = fold_if_not_in_template (*pfn);
6245 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6247 case ptrmemfunc_vbit_in_pfn:
6248 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6250 *pfn = fold_if_not_in_template (*pfn);
6253 case ptrmemfunc_vbit_in_delta:
6254 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6255 *delta, integer_one_node);
6256 *delta = fold_if_not_in_template (*delta);
6257 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6258 *delta, integer_one_node);
6259 *delta = fold_if_not_in_template (*delta);
6266 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6267 *pfn = fold_if_not_in_template (*pfn);
6271 /* Return an expression for PFN from the pointer-to-member function
6275 pfn_from_ptrmemfunc (tree t)
6277 if (TREE_CODE (t) == PTRMEM_CST)
6282 expand_ptrmemfunc_cst (t, &delta, &pfn);
6287 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6290 /* Return an expression for DELTA from the pointer-to-member function
6294 delta_from_ptrmemfunc (tree t)
6296 if (TREE_CODE (t) == PTRMEM_CST)
6301 expand_ptrmemfunc_cst (t, &delta, &pfn);
6306 return build_ptrmemfunc_access_expr (t, delta_identifier);
6309 /* Convert value RHS to type TYPE as preparation for an assignment to
6310 an lvalue of type TYPE. ERRTYPE is a string to use in error
6311 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6312 are doing the conversion in order to pass the PARMNUMth argument of
6316 convert_for_assignment (tree type, tree rhs,
6317 const char *errtype, tree fndecl, int parmnum)
6320 enum tree_code coder;
6322 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6323 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6324 rhs = TREE_OPERAND (rhs, 0);
6326 rhstype = TREE_TYPE (rhs);
6327 coder = TREE_CODE (rhstype);
6329 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6330 && vector_types_convertible_p (type, rhstype, true))
6331 return convert (type, rhs);
6333 if (rhs == error_mark_node || rhstype == error_mark_node)
6334 return error_mark_node;
6335 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6336 return error_mark_node;
6338 /* The RHS of an assignment cannot have void type. */
6339 if (coder == VOID_TYPE)
6341 error ("void value not ignored as it ought to be");
6342 return error_mark_node;
6345 /* Simplify the RHS if possible. */
6346 if (TREE_CODE (rhs) == CONST_DECL)
6347 rhs = DECL_INITIAL (rhs);
6349 if (c_dialect_objc ())
6352 tree rname = fndecl;
6354 if (!strcmp (errtype, "assignment"))
6356 else if (!strcmp (errtype, "initialization"))
6360 tree selector = objc_message_selector ();
6364 if (selector && parmno > 1)
6371 if (objc_compare_types (type, rhstype, parmno, rname))
6372 return convert (type, rhs);
6377 The expression is implicitly converted (clause _conv_) to the
6378 cv-unqualified type of the left operand.
6380 We allow bad conversions here because by the time we get to this point
6381 we are committed to doing the conversion. If we end up doing a bad
6382 conversion, convert_like will complain. */
6383 if (!can_convert_arg_bad (type, rhstype, rhs))
6385 /* When -Wno-pmf-conversions is use, we just silently allow
6386 conversions from pointers-to-members to plain pointers. If
6387 the conversion doesn't work, cp_convert will complain. */
6389 && TYPE_PTR_P (type)
6390 && TYPE_PTRMEMFUNC_P (rhstype))
6391 rhs = cp_convert (strip_top_quals (type), rhs);
6394 /* If the right-hand side has unknown type, then it is an
6395 overloaded function. Call instantiate_type to get error
6397 if (rhstype == unknown_type_node)
6398 instantiate_type (type, rhs, tf_warning_or_error);
6400 error ("cannot convert %qT to %qT for argument %qP to %qD",
6401 rhstype, type, parmnum, fndecl);
6403 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6404 return error_mark_node;
6407 if (warn_missing_format_attribute)
6409 const enum tree_code codel = TREE_CODE (type);
6410 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6412 && check_missing_format_attribute (type, rhstype))
6413 warning (OPT_Wmissing_format_attribute,
6414 "%s might be a candidate for a format attribute",
6418 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6420 if (warn_parentheses
6421 && type == boolean_type_node
6422 && TREE_CODE (rhs) == MODIFY_EXPR
6423 && !TREE_NO_WARNING (rhs)
6424 && TREE_TYPE (rhs) != boolean_type_node)
6426 warning (OPT_Wparentheses,
6427 "suggest parentheses around assignment used as truth value");
6428 TREE_NO_WARNING (rhs) = 1;
6431 return perform_implicit_conversion (strip_top_quals (type), rhs);
6434 /* Convert RHS to be of type TYPE.
6435 If EXP is nonzero, it is the target of the initialization.
6436 ERRTYPE is a string to use in error messages.
6438 Two major differences between the behavior of
6439 `convert_for_assignment' and `convert_for_initialization'
6440 are that references are bashed in the former, while
6441 copied in the latter, and aggregates are assigned in
6442 the former (operator=) while initialized in the
6445 If using constructor make sure no conversion operator exists, if one does
6446 exist, an ambiguity exists.
6448 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6451 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6452 const char *errtype, tree fndecl, int parmnum)
6454 enum tree_code codel = TREE_CODE (type);
6456 enum tree_code coder;
6458 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6459 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6460 if (TREE_CODE (rhs) == NOP_EXPR
6461 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6462 && codel != REFERENCE_TYPE)
6463 rhs = TREE_OPERAND (rhs, 0);
6465 if (type == error_mark_node
6466 || rhs == error_mark_node
6467 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6468 return error_mark_node;
6470 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6471 && TREE_CODE (type) != ARRAY_TYPE
6472 && (TREE_CODE (type) != REFERENCE_TYPE
6473 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6474 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6475 && (TREE_CODE (type) != REFERENCE_TYPE
6476 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6477 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6478 rhs = decay_conversion (rhs);
6480 rhstype = TREE_TYPE (rhs);
6481 coder = TREE_CODE (rhstype);
6483 if (coder == ERROR_MARK)
6484 return error_mark_node;
6486 /* We accept references to incomplete types, so we can
6487 return here before checking if RHS is of complete type. */
6489 if (codel == REFERENCE_TYPE)
6491 /* This should eventually happen in convert_arguments. */
6492 int savew = 0, savee = 0;
6495 savew = warningcount, savee = errorcount;
6496 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6500 if (warningcount > savew)
6501 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6502 else if (errorcount > savee)
6503 error ("in passing argument %P of %q+D", parmnum, fndecl);
6509 exp = require_complete_type (exp);
6510 if (exp == error_mark_node)
6511 return error_mark_node;
6513 rhstype = non_reference (rhstype);
6515 type = complete_type (type);
6517 if (IS_AGGR_TYPE (type))
6518 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6520 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6523 /* If RETVAL is the address of, or a reference to, a local variable or
6524 temporary give an appropriate warning. */
6527 maybe_warn_about_returning_address_of_local (tree retval)
6529 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6530 tree whats_returned = retval;
6534 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6535 whats_returned = TREE_OPERAND (whats_returned, 1);
6536 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6537 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6538 || TREE_CODE (whats_returned) == NOP_EXPR)
6539 whats_returned = TREE_OPERAND (whats_returned, 0);
6544 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6546 whats_returned = TREE_OPERAND (whats_returned, 0);
6548 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6550 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6551 || TREE_CODE (whats_returned) == TARGET_EXPR)
6553 warning (0, "returning reference to temporary");
6556 if (TREE_CODE (whats_returned) == VAR_DECL
6557 && DECL_NAME (whats_returned)
6558 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6560 warning (0, "reference to non-lvalue returned");
6565 while (TREE_CODE (whats_returned) == COMPONENT_REF
6566 || TREE_CODE (whats_returned) == ARRAY_REF)
6567 whats_returned = TREE_OPERAND (whats_returned, 0);
6569 if (DECL_P (whats_returned)
6570 && DECL_NAME (whats_returned)
6571 && DECL_FUNCTION_SCOPE_P (whats_returned)
6572 && !(TREE_STATIC (whats_returned)
6573 || TREE_PUBLIC (whats_returned)))
6575 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6576 warning (0, "reference to local variable %q+D returned",
6579 warning (0, "address of local variable %q+D returned",
6585 /* Check that returning RETVAL from the current function is valid.
6586 Return an expression explicitly showing all conversions required to
6587 change RETVAL into the function return type, and to assign it to
6588 the DECL_RESULT for the function. Set *NO_WARNING to true if
6589 code reaches end of non-void function warning shouldn't be issued
6590 on this RETURN_EXPR. */
6593 check_return_expr (tree retval, bool *no_warning)
6596 /* The type actually returned by the function, after any
6599 int fn_returns_value_p;
6600 bool named_return_value_okay_p;
6602 *no_warning = false;
6604 /* A `volatile' function is one that isn't supposed to return, ever.
6605 (This is a G++ extension, used to get better code for functions
6606 that call the `volatile' function.) */
6607 if (TREE_THIS_VOLATILE (current_function_decl))
6608 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6610 /* Check for various simple errors. */
6611 if (DECL_DESTRUCTOR_P (current_function_decl))
6614 error ("returning a value from a destructor");
6617 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6619 if (in_function_try_handler)
6620 /* If a return statement appears in a handler of the
6621 function-try-block of a constructor, the program is ill-formed. */
6622 error ("cannot return from a handler of a function-try-block of a constructor");
6624 /* You can't return a value from a constructor. */
6625 error ("returning a value from a constructor");
6629 if (processing_template_decl)
6631 current_function_returns_value = 1;
6632 if (check_for_bare_parameter_packs (retval))
6633 retval = error_mark_node;
6637 /* When no explicit return-value is given in a function with a named
6638 return value, the named return value is used. */
6639 result = DECL_RESULT (current_function_decl);
6640 valtype = TREE_TYPE (result);
6641 gcc_assert (valtype != NULL_TREE);
6642 fn_returns_value_p = !VOID_TYPE_P (valtype);
6643 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6646 /* Check for a return statement with no return value in a function
6647 that's supposed to return a value. */
6648 if (!retval && fn_returns_value_p)
6650 pedwarn ("return-statement with no value, in function returning %qT",
6652 /* Clear this, so finish_function won't say that we reach the
6653 end of a non-void function (which we don't, we gave a
6655 current_function_returns_null = 0;
6656 /* And signal caller that TREE_NO_WARNING should be set on the
6657 RETURN_EXPR to avoid control reaches end of non-void function
6658 warnings in tree-cfg.c. */
6661 /* Check for a return statement with a value in a function that
6662 isn't supposed to return a value. */
6663 else if (retval && !fn_returns_value_p)
6665 if (VOID_TYPE_P (TREE_TYPE (retval)))
6666 /* You can return a `void' value from a function of `void'
6667 type. In that case, we have to evaluate the expression for
6668 its side-effects. */
6669 finish_expr_stmt (retval);
6671 pedwarn ("return-statement with a value, in function "
6672 "returning 'void'");
6674 current_function_returns_null = 1;
6676 /* There's really no value to return, after all. */
6680 /* Remember that this function can sometimes return without a
6682 current_function_returns_null = 1;
6684 /* Remember that this function did return a value. */
6685 current_function_returns_value = 1;
6687 /* Check for erroneous operands -- but after giving ourselves a
6688 chance to provide an error about returning a value from a void
6690 if (error_operand_p (retval))
6692 current_function_return_value = error_mark_node;
6693 return error_mark_node;
6696 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6697 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6698 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6699 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6701 && retval && null_ptr_cst_p (retval))
6702 warning (0, "%<operator new%> must not return NULL unless it is "
6703 "declared %<throw()%> (or -fcheck-new is in effect)");
6705 /* Effective C++ rule 15. See also start_function. */
6707 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6711 /* The function return type must be a reference to the current
6713 if (TREE_CODE (valtype) == REFERENCE_TYPE
6714 && same_type_ignoring_top_level_qualifiers_p
6715 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6717 /* Returning '*this' is obviously OK. */
6718 if (retval == current_class_ref)
6720 /* If we are calling a function whose return type is the same of
6721 the current class reference, it is ok. */
6722 else if (TREE_CODE (retval) == INDIRECT_REF
6723 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6728 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6731 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6733 [...] For a function with a class return type, if the expression
6734 in the return statement is the name of a local object, and the cv-
6735 unqualified type of the local object is the same as the function
6736 return type, an implementation is permitted to omit creating the tem-
6737 porary object to hold the function return value [...]
6739 So, if this is a value-returning function that always returns the same
6740 local variable, remember it.
6742 It might be nice to be more flexible, and choose the first suitable
6743 variable even if the function sometimes returns something else, but
6744 then we run the risk of clobbering the variable we chose if the other
6745 returned expression uses the chosen variable somehow. And people expect
6746 this restriction, anyway. (jason 2000-11-19)
6748 See finish_function and finalize_nrv for the rest of this optimization. */
6750 named_return_value_okay_p =
6751 (retval != NULL_TREE
6752 /* Must be a local, automatic variable. */
6753 && TREE_CODE (retval) == VAR_DECL
6754 && DECL_CONTEXT (retval) == current_function_decl
6755 && ! TREE_STATIC (retval)
6756 && ! DECL_ANON_UNION_VAR_P (retval)
6757 && (DECL_ALIGN (retval)
6758 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6759 /* The cv-unqualified type of the returned value must be the
6760 same as the cv-unqualified return type of the
6762 && same_type_p ((TYPE_MAIN_VARIANT (TREE_TYPE (retval))),
6764 (TREE_TYPE (TREE_TYPE (current_function_decl)))))
6765 /* And the returned value must be non-volatile. */
6766 && ! TYPE_VOLATILE (TREE_TYPE (retval)));
6768 if (fn_returns_value_p && flag_elide_constructors)
6770 if (named_return_value_okay_p
6771 && (current_function_return_value == NULL_TREE
6772 || current_function_return_value == retval))
6773 current_function_return_value = retval;
6775 current_function_return_value = error_mark_node;
6778 /* We don't need to do any conversions when there's nothing being
6783 /* Do any required conversions. */
6784 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6785 /* No conversions are required. */
6789 /* The type the function is declared to return. */
6790 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6791 int flags = LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING;
6793 /* The functype's return type will have been set to void, if it
6794 was an incomplete type. Just treat this as 'return;' */
6795 if (VOID_TYPE_P (functype))
6796 return error_mark_node;
6798 /* Under C++0x [12.8/16 class.copy], a returned lvalue is sometimes
6799 treated as an rvalue for the purposes of overload resolution to
6800 favor move constructors over copy constructors. */
6801 if ((cxx_dialect != cxx98)
6802 && named_return_value_okay_p
6803 /* The variable must not have the `volatile' qualifier. */
6804 && !(cp_type_quals (TREE_TYPE (retval)) & TYPE_QUAL_VOLATILE)
6805 /* The return type must be a class type. */
6806 && CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (current_function_decl))))
6807 flags = flags | LOOKUP_PREFER_RVALUE;
6809 /* First convert the value to the function's return type, then
6810 to the type of return value's location to handle the
6811 case that functype is smaller than the valtype. */
6812 retval = convert_for_initialization
6813 (NULL_TREE, functype, retval, flags, "return", NULL_TREE, 0);
6814 retval = convert (valtype, retval);
6816 /* If the conversion failed, treat this just like `return;'. */
6817 if (retval == error_mark_node)
6819 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6820 else if (! current_function_returns_struct
6821 && TREE_CODE (retval) == TARGET_EXPR
6822 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6823 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6824 TREE_OPERAND (retval, 0));
6826 maybe_warn_about_returning_address_of_local (retval);
6829 /* Actually copy the value returned into the appropriate location. */
6830 if (retval && retval != result)
6831 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6837 /* Returns nonzero if the pointer-type FROM can be converted to the
6838 pointer-type TO via a qualification conversion. If CONSTP is -1,
6839 then we return nonzero if the pointers are similar, and the
6840 cv-qualification signature of FROM is a proper subset of that of TO.
6842 If CONSTP is positive, then all outer pointers have been
6846 comp_ptr_ttypes_real (tree to, tree from, int constp)
6848 bool to_more_cv_qualified = false;
6850 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6852 if (TREE_CODE (to) != TREE_CODE (from))
6855 if (TREE_CODE (from) == OFFSET_TYPE
6856 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6857 TYPE_OFFSET_BASETYPE (to)))
6860 /* Const and volatile mean something different for function types,
6861 so the usual checks are not appropriate. */
6862 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6864 /* In Objective-C++, some types may have been 'volatilized' by
6865 the compiler for EH; when comparing them here, the volatile
6866 qualification must be ignored. */
6867 bool objc_quals_match = objc_type_quals_match (to, from);
6869 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6872 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6876 to_more_cv_qualified = true;
6880 constp &= TYPE_READONLY (to);
6883 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6884 return ((constp >= 0 || to_more_cv_qualified)
6885 && same_type_ignoring_top_level_qualifiers_p (to, from));
6889 /* When comparing, say, char ** to char const **, this function takes
6890 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6891 types to this function. */
6894 comp_ptr_ttypes (tree to, tree from)
6896 return comp_ptr_ttypes_real (to, from, 1);
6899 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6900 type or inheritance-related types, regardless of cv-quals. */
6903 ptr_reasonably_similar (const_tree to, const_tree from)
6905 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6907 /* Any target type is similar enough to void. */
6908 if (TREE_CODE (to) == VOID_TYPE
6909 || TREE_CODE (from) == VOID_TYPE)
6912 if (TREE_CODE (to) != TREE_CODE (from))
6915 if (TREE_CODE (from) == OFFSET_TYPE
6916 && comptypes (TYPE_OFFSET_BASETYPE (to),
6917 TYPE_OFFSET_BASETYPE (from),
6918 COMPARE_BASE | COMPARE_DERIVED))
6921 if (TREE_CODE (to) == VECTOR_TYPE
6922 && vector_types_convertible_p (to, from, false))
6925 if (TREE_CODE (to) == INTEGER_TYPE
6926 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6929 if (TREE_CODE (to) == FUNCTION_TYPE)
6932 if (TREE_CODE (to) != POINTER_TYPE)
6934 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6935 COMPARE_BASE | COMPARE_DERIVED);
6939 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6940 pointer-to-member types) are the same, ignoring cv-qualification at
6944 comp_ptr_ttypes_const (tree to, tree from)
6946 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6948 if (TREE_CODE (to) != TREE_CODE (from))
6951 if (TREE_CODE (from) == OFFSET_TYPE
6952 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6953 TYPE_OFFSET_BASETYPE (to)))
6956 if (TREE_CODE (to) != POINTER_TYPE)
6957 return same_type_ignoring_top_level_qualifiers_p (to, from);
6961 /* Returns the type qualifiers for this type, including the qualifiers on the
6962 elements for an array type. */
6965 cp_type_quals (const_tree type)
6967 /* This CONST_CAST is okay because strip_array_types returns it's
6968 argument unmodified and we assign it to a const_tree. */
6969 type = strip_array_types (CONST_CAST_TREE(type));
6970 if (type == error_mark_node)
6971 return TYPE_UNQUALIFIED;
6972 return TYPE_QUALS (type);
6975 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6979 cp_type_readonly (const_tree type)
6981 /* This CONST_CAST is okay because strip_array_types returns it's
6982 argument unmodified and we assign it to a const_tree. */
6983 type = strip_array_types (CONST_CAST_TREE(type));
6984 return TYPE_READONLY (type);
6987 /* Returns nonzero if the TYPE contains a mutable member. */
6990 cp_has_mutable_p (const_tree type)
6992 /* This CONST_CAST is okay because strip_array_types returns it's
6993 argument unmodified and we assign it to a const_tree. */
6994 type = strip_array_types (CONST_CAST_TREE(type));
6996 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6999 /* Set TREE_READONLY and TREE_VOLATILE on DECL as indicated by the
7000 TYPE_QUALS. For a VAR_DECL, this may be an optimistic
7001 approximation. In particular, consider:
7004 struct S { int i; };
7005 const S s = { f(); }
7007 Here, we will make "s" as TREE_READONLY (because it is declared
7008 "const") -- only to reverse ourselves upon seeing that the
7009 initializer is non-constant. */
7012 cp_apply_type_quals_to_decl (int type_quals, tree decl)
7014 tree type = TREE_TYPE (decl);
7016 if (type == error_mark_node)
7019 if (TREE_CODE (type) == FUNCTION_TYPE
7020 && type_quals != TYPE_UNQUALIFIED)
7022 /* This was an error in C++98 (cv-qualifiers cannot be added to
7023 a function type), but DR 295 makes the code well-formed by
7024 dropping the extra qualifiers. */
7027 tree bad_type = build_qualified_type (type, type_quals);
7028 pedwarn ("ignoring %qV qualifiers added to function type %qT",
7032 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
7036 /* Avoid setting TREE_READONLY incorrectly. */
7037 if (/* If the object has a constructor, the constructor may modify
7039 TYPE_NEEDS_CONSTRUCTING (type)
7040 /* If the type isn't complete, we don't know yet if it will need
7042 || !COMPLETE_TYPE_P (type)
7043 /* If the type has a mutable component, that component might be
7045 || TYPE_HAS_MUTABLE_P (type))
7046 type_quals &= ~TYPE_QUAL_CONST;
7048 c_apply_type_quals_to_decl (type_quals, decl);
7051 /* Subroutine of casts_away_constness. Make T1 and T2 point at
7052 exemplar types such that casting T1 to T2 is casting away constness
7053 if and only if there is no implicit conversion from T1 to T2. */
7056 casts_away_constness_r (tree *t1, tree *t2)
7061 /* [expr.const.cast]
7063 For multi-level pointer to members and multi-level mixed pointers
7064 and pointers to members (conv.qual), the "member" aspect of a
7065 pointer to member level is ignored when determining if a const
7066 cv-qualifier has been cast away. */
7067 /* [expr.const.cast]
7069 For two pointer types:
7071 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
7072 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
7075 casting from X1 to X2 casts away constness if, for a non-pointer
7076 type T there does not exist an implicit conversion (clause
7079 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
7083 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
7084 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
7085 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
7087 *t1 = cp_build_qualified_type (void_type_node,
7088 cp_type_quals (*t1));
7089 *t2 = cp_build_qualified_type (void_type_node,
7090 cp_type_quals (*t2));
7094 quals1 = cp_type_quals (*t1);
7095 quals2 = cp_type_quals (*t2);
7097 if (TYPE_PTRMEM_P (*t1))
7098 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
7100 *t1 = TREE_TYPE (*t1);
7101 if (TYPE_PTRMEM_P (*t2))
7102 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
7104 *t2 = TREE_TYPE (*t2);
7106 casts_away_constness_r (t1, t2);
7107 *t1 = build_pointer_type (*t1);
7108 *t2 = build_pointer_type (*t2);
7109 *t1 = cp_build_qualified_type (*t1, quals1);
7110 *t2 = cp_build_qualified_type (*t2, quals2);
7113 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
7117 casts_away_constness (tree t1, tree t2)
7119 if (TREE_CODE (t2) == REFERENCE_TYPE)
7121 /* [expr.const.cast]
7123 Casting from an lvalue of type T1 to an lvalue of type T2
7124 using a reference cast casts away constness if a cast from an
7125 rvalue of type "pointer to T1" to the type "pointer to T2"
7126 casts away constness. */
7127 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
7128 return casts_away_constness (build_pointer_type (t1),
7129 build_pointer_type (TREE_TYPE (t2)));
7132 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
7133 /* [expr.const.cast]
7135 Casting from an rvalue of type "pointer to data member of X
7136 of type T1" to the type "pointer to data member of Y of type
7137 T2" casts away constness if a cast from an rvalue of type
7138 "pointer to T1" to the type "pointer to T2" casts away
7140 return casts_away_constness
7141 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7142 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7144 /* Casting away constness is only something that makes sense for
7145 pointer or reference types. */
7146 if (TREE_CODE (t1) != POINTER_TYPE
7147 || TREE_CODE (t2) != POINTER_TYPE)
7150 /* Top-level qualifiers don't matter. */
7151 t1 = TYPE_MAIN_VARIANT (t1);
7152 t2 = TYPE_MAIN_VARIANT (t2);
7153 casts_away_constness_r (&t1, &t2);
7154 if (!can_convert (t2, t1))
7160 /* If T is a REFERENCE_TYPE return the type to which T refers.
7161 Otherwise, return T itself. */
7164 non_reference (tree t)
7166 if (TREE_CODE (t) == REFERENCE_TYPE)
7172 /* Return nonzero if REF is an lvalue valid for this language;
7173 otherwise, print an error message and return zero. USE says
7174 how the lvalue is being used and so selects the error message. */
7177 lvalue_or_else (const_tree ref, enum lvalue_use use)
7179 int win = lvalue_p (ref);