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 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
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"
46 static tree convert_for_assignment (tree, tree, const char *, tree, int);
47 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
48 static tree rationalize_conditional_expr (enum tree_code, tree);
49 static int comp_ptr_ttypes_real (tree, tree, int);
50 static bool comp_except_types (tree, tree, bool);
51 static bool comp_array_types (tree, tree, bool);
52 static tree common_base_type (tree, tree);
53 static tree pointer_diff (tree, tree, tree);
54 static tree get_delta_difference (tree, tree, bool, bool);
55 static void casts_away_constness_r (tree *, tree *);
56 static bool casts_away_constness (tree, tree);
57 static void maybe_warn_about_returning_address_of_local (tree);
58 static tree lookup_destructor (tree, tree, tree);
59 static tree convert_arguments (tree, tree, tree, int);
61 /* Do `exp = require_complete_type (exp);' to make sure exp
62 does not have an incomplete type. (That includes void types.)
63 Returns the error_mark_node if the VALUE does not have
64 complete type when this function returns. */
67 require_complete_type (tree value)
71 if (processing_template_decl || value == error_mark_node)
74 if (TREE_CODE (value) == OVERLOAD)
75 type = unknown_type_node;
77 type = TREE_TYPE (value);
79 if (type == error_mark_node)
80 return error_mark_node;
82 /* First, detect a valid value with a complete type. */
83 if (COMPLETE_TYPE_P (type))
86 if (complete_type_or_else (type, value))
89 return error_mark_node;
92 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
93 a template instantiation, do the instantiation. Returns TYPE,
94 whether or not it could be completed, unless something goes
95 horribly wrong, in which case the error_mark_node is returned. */
98 complete_type (tree type)
100 if (type == NULL_TREE)
101 /* Rather than crash, we return something sure to cause an error
103 return error_mark_node;
105 if (type == error_mark_node || COMPLETE_TYPE_P (type))
107 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
109 tree t = complete_type (TREE_TYPE (type));
110 unsigned int needs_constructing, has_nontrivial_dtor;
111 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
114 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
116 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
117 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
119 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
120 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
123 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
124 instantiate_class_template (TYPE_MAIN_VARIANT (type));
129 /* Like complete_type, but issue an error if the TYPE cannot be completed.
130 VALUE is used for informative diagnostics.
131 Returns NULL_TREE if the type cannot be made complete. */
134 complete_type_or_else (tree type, tree value)
136 type = complete_type (type);
137 if (type == error_mark_node)
138 /* We already issued an error. */
140 else if (!COMPLETE_TYPE_P (type))
142 cxx_incomplete_type_diagnostic (value, type, 0);
149 /* Return truthvalue of whether type of EXP is instantiated. */
152 type_unknown_p (tree exp)
154 return (TREE_CODE (exp) == TREE_LIST
155 || TREE_TYPE (exp) == unknown_type_node);
159 /* Return the common type of two parameter lists.
160 We assume that comptypes has already been done and returned 1;
161 if that isn't so, this may crash.
163 As an optimization, free the space we allocate if the parameter
164 lists are already common. */
167 commonparms (tree p1, tree p2)
169 tree oldargs = p1, newargs, n;
173 len = list_length (p1);
174 newargs = tree_last (p1);
176 if (newargs == void_list_node)
185 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
190 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
192 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
194 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
197 else if (! TREE_PURPOSE (p1))
199 if (TREE_PURPOSE (p2))
201 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
207 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
209 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
211 if (TREE_VALUE (p1) != TREE_VALUE (p2))
214 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
217 TREE_VALUE (n) = TREE_VALUE (p1);
225 /* Given a type, perhaps copied for a typedef,
226 find the "original" version of it. */
228 original_type (tree t)
230 while (TYPE_NAME (t) != NULL_TREE)
232 tree x = TYPE_NAME (t);
233 if (TREE_CODE (x) != TYPE_DECL)
235 x = DECL_ORIGINAL_TYPE (x);
243 /* T1 and T2 are arithmetic or enumeration types. Return the type
244 that will result from the "usual arithmetic conversions" on T1 and
245 T2 as described in [expr]. */
248 type_after_usual_arithmetic_conversions (tree t1, tree t2)
250 enum tree_code code1 = TREE_CODE (t1);
251 enum tree_code code2 = TREE_CODE (t2);
254 /* FIXME: Attributes. */
255 gcc_assert (ARITHMETIC_TYPE_P (t1)
256 || TREE_CODE (t1) == COMPLEX_TYPE
257 || TREE_CODE (t1) == VECTOR_TYPE
258 || TREE_CODE (t1) == ENUMERAL_TYPE);
259 gcc_assert (ARITHMETIC_TYPE_P (t2)
260 || TREE_CODE (t2) == COMPLEX_TYPE
261 || TREE_CODE (t1) == VECTOR_TYPE
262 || TREE_CODE (t2) == ENUMERAL_TYPE);
264 /* In what follows, we slightly generalize the rules given in [expr] so
265 as to deal with `long long' and `complex'. First, merge the
267 attributes = (*targetm.merge_type_attributes) (t1, t2);
269 /* If one type is complex, form the common type of the non-complex
270 components, then make that complex. Use T1 or T2 if it is the
272 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
274 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
275 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
277 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
279 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
280 return build_type_attribute_variant (t1, attributes);
281 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
282 return build_type_attribute_variant (t2, attributes);
284 return build_type_attribute_variant (build_complex_type (subtype),
288 if (code1 == VECTOR_TYPE)
290 /* When we get here we should have two vectors of the same size.
291 Just prefer the unsigned one if present. */
292 if (TYPE_UNSIGNED (t1))
293 return build_type_attribute_variant (t1, attributes);
295 return build_type_attribute_variant (t2, attributes);
298 /* If only one is real, use it as the result. */
299 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
300 return build_type_attribute_variant (t1, attributes);
301 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
302 return build_type_attribute_variant (t2, attributes);
304 /* Perform the integral promotions. */
305 if (code1 != REAL_TYPE)
307 t1 = type_promotes_to (t1);
308 t2 = type_promotes_to (t2);
311 /* Both real or both integers; use the one with greater precision. */
312 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
313 return build_type_attribute_variant (t1, attributes);
314 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
315 return build_type_attribute_variant (t2, attributes);
317 /* The types are the same; no need to do anything fancy. */
318 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
319 return build_type_attribute_variant (t1, attributes);
321 if (code1 != REAL_TYPE)
323 /* If one is a sizetype, use it so size_binop doesn't blow up. */
324 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
325 return build_type_attribute_variant (t1, attributes);
326 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
327 return build_type_attribute_variant (t2, attributes);
329 /* If one is unsigned long long, then convert the other to unsigned
331 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
332 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
333 return build_type_attribute_variant (long_long_unsigned_type_node,
335 /* If one is a long long, and the other is an unsigned long, and
336 long long can represent all the values of an unsigned long, then
337 convert to a long long. Otherwise, convert to an unsigned long
338 long. Otherwise, if either operand is long long, convert the
341 Since we're here, we know the TYPE_PRECISION is the same;
342 therefore converting to long long cannot represent all the values
343 of an unsigned long, so we choose unsigned long long in that
345 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
346 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
348 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
349 ? long_long_unsigned_type_node
350 : long_long_integer_type_node);
351 return build_type_attribute_variant (t, attributes);
354 /* Go through the same procedure, but for longs. */
355 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
356 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
357 return build_type_attribute_variant (long_unsigned_type_node,
359 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
360 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
362 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
363 ? long_unsigned_type_node : long_integer_type_node);
364 return build_type_attribute_variant (t, attributes);
366 /* Otherwise prefer the unsigned one. */
367 if (TYPE_UNSIGNED (t1))
368 return build_type_attribute_variant (t1, attributes);
370 return build_type_attribute_variant (t2, attributes);
374 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
375 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
376 return build_type_attribute_variant (long_double_type_node,
378 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
379 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
380 return build_type_attribute_variant (double_type_node,
382 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
383 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
384 return build_type_attribute_variant (float_type_node,
387 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
388 the standard C++ floating-point types. Logic earlier in this
389 function has already eliminated the possibility that
390 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
391 compelling reason to choose one or the other. */
392 return build_type_attribute_variant (t1, attributes);
396 /* Subroutine of composite_pointer_type to implement the recursive
397 case. See that function for documentation fo the parameters. */
400 composite_pointer_type_r (tree t1, tree t2, const char* location)
407 /* Determine the types pointed to by T1 and T2. */
408 if (TREE_CODE (t1) == POINTER_TYPE)
410 pointee1 = TREE_TYPE (t1);
411 pointee2 = TREE_TYPE (t2);
415 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
416 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
421 Otherwise, the composite pointer type is a pointer type
422 similar (_conv.qual_) to the type of one of the operands,
423 with a cv-qualification signature (_conv.qual_) that is the
424 union of the cv-qualification signatures of the operand
426 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
427 result_type = pointee1;
428 else if ((TREE_CODE (pointee1) == POINTER_TYPE
429 && TREE_CODE (pointee2) == POINTER_TYPE)
430 || (TYPE_PTR_TO_MEMBER_P (pointee1)
431 && TYPE_PTR_TO_MEMBER_P (pointee2)))
432 result_type = composite_pointer_type_r (pointee1, pointee2, location);
435 pedwarn ("%s between distinct pointer types %qT and %qT "
438 result_type = void_type_node;
440 result_type = cp_build_qualified_type (result_type,
441 (cp_type_quals (pointee1)
442 | cp_type_quals (pointee2)));
443 /* If the original types were pointers to members, so is the
445 if (TYPE_PTR_TO_MEMBER_P (t1))
447 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
448 TYPE_PTRMEM_CLASS_TYPE (t2)))
449 pedwarn ("%s between distinct pointer types %qT and %qT "
452 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
456 result_type = build_pointer_type (result_type);
458 /* Merge the attributes. */
459 attributes = (*targetm.merge_type_attributes) (t1, t2);
460 return build_type_attribute_variant (result_type, attributes);
463 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
464 ARG1 and ARG2 are the values with those types. The LOCATION is a
465 string describing the current location, in case an error occurs.
467 This routine also implements the computation of a common type for
468 pointers-to-members as per [expr.eq]. */
471 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
472 const char* location)
479 If one operand is a null pointer constant, the composite pointer
480 type is the type of the other operand. */
481 if (null_ptr_cst_p (arg1))
483 if (null_ptr_cst_p (arg2))
490 If one of the operands has type "pointer to cv1 void*", then
491 the other has type "pointer to cv2T", and the composite pointer
492 type is "pointer to cv12 void", where cv12 is the union of cv1
495 If either type is a pointer to void, make sure it is T1. */
496 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
504 /* Now, if T1 is a pointer to void, merge the qualifiers. */
505 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
510 if (pedantic && TYPE_PTRFN_P (t2))
511 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
512 "and pointer-to-function", location);
514 = cp_build_qualified_type (void_type_node,
515 (cp_type_quals (TREE_TYPE (t1))
516 | cp_type_quals (TREE_TYPE (t2))));
517 result_type = build_pointer_type (result_type);
518 /* Merge the attributes. */
519 attributes = (*targetm.merge_type_attributes) (t1, t2);
520 return build_type_attribute_variant (result_type, attributes);
523 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
524 && TREE_CODE (t2) == POINTER_TYPE)
526 if (objc_compare_types (t1, t2, -3, NULL_TREE))
530 /* [expr.eq] permits the application of a pointer conversion to
531 bring the pointers to a common type. */
532 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
533 && CLASS_TYPE_P (TREE_TYPE (t1))
534 && CLASS_TYPE_P (TREE_TYPE (t2))
535 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
538 class1 = TREE_TYPE (t1);
539 class2 = TREE_TYPE (t2);
541 if (DERIVED_FROM_P (class1, class2))
542 t2 = (build_pointer_type
543 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
544 else if (DERIVED_FROM_P (class2, class1))
545 t1 = (build_pointer_type
546 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
549 error ("%s between distinct pointer types %qT and %qT "
550 "lacks a cast", location, t1, t2);
551 return error_mark_node;
554 /* [expr.eq] permits the application of a pointer-to-member
555 conversion to change the class type of one of the types. */
556 else if (TYPE_PTR_TO_MEMBER_P (t1)
557 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
558 TYPE_PTRMEM_CLASS_TYPE (t2)))
560 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
561 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
563 if (DERIVED_FROM_P (class1, class2))
564 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
565 else if (DERIVED_FROM_P (class2, class1))
566 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
569 error ("%s between distinct pointer-to-member types %qT and %qT "
570 "lacks a cast", location, t1, t2);
571 return error_mark_node;
575 return composite_pointer_type_r (t1, t2, location);
578 /* Return the merged type of two types.
579 We assume that comptypes has already been done and returned 1;
580 if that isn't so, this may crash.
582 This just combines attributes and default arguments; any other
583 differences would cause the two types to compare unalike. */
586 merge_types (tree t1, tree t2)
588 enum tree_code code1;
589 enum tree_code code2;
592 /* Save time if the two types are the same. */
595 if (original_type (t1) == original_type (t2))
598 /* If one type is nonsense, use the other. */
599 if (t1 == error_mark_node)
601 if (t2 == error_mark_node)
604 /* Merge the attributes. */
605 attributes = (*targetm.merge_type_attributes) (t1, t2);
607 if (TYPE_PTRMEMFUNC_P (t1))
608 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
609 if (TYPE_PTRMEMFUNC_P (t2))
610 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
612 code1 = TREE_CODE (t1);
613 code2 = TREE_CODE (t2);
619 /* For two pointers, do this recursively on the target type. */
621 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
622 int quals = cp_type_quals (t1);
624 if (code1 == POINTER_TYPE)
625 t1 = build_pointer_type (target);
627 t1 = build_reference_type (target);
628 t1 = build_type_attribute_variant (t1, attributes);
629 t1 = cp_build_qualified_type (t1, quals);
631 if (TREE_CODE (target) == METHOD_TYPE)
632 t1 = build_ptrmemfunc_type (t1);
641 quals = cp_type_quals (t1);
642 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
643 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
644 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
646 t1 = cp_build_qualified_type (t1, quals);
652 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
653 /* Save space: see if the result is identical to one of the args. */
654 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
655 return build_type_attribute_variant (t1, attributes);
656 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
657 return build_type_attribute_variant (t2, attributes);
658 /* Merge the element types, and have a size if either arg has one. */
659 t1 = build_cplus_array_type
660 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
665 /* Function types: prefer the one that specified arg types.
666 If both do, merge the arg types. Also merge the return types. */
668 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
669 tree p1 = TYPE_ARG_TYPES (t1);
670 tree p2 = TYPE_ARG_TYPES (t2);
673 /* Save space: see if the result is identical to one of the args. */
674 if (valtype == TREE_TYPE (t1) && ! p2)
675 return cp_build_type_attribute_variant (t1, attributes);
676 if (valtype == TREE_TYPE (t2) && ! p1)
677 return cp_build_type_attribute_variant (t2, attributes);
679 /* Simple way if one arg fails to specify argument types. */
680 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
682 rval = build_function_type (valtype, p2);
683 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
684 rval = build_exception_variant (rval, raises);
685 return cp_build_type_attribute_variant (rval, attributes);
687 raises = TYPE_RAISES_EXCEPTIONS (t1);
688 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
690 rval = build_function_type (valtype, p1);
692 rval = build_exception_variant (rval, raises);
693 return cp_build_type_attribute_variant (rval, attributes);
696 rval = build_function_type (valtype, commonparms (p1, p2));
697 t1 = build_exception_variant (rval, raises);
703 /* Get this value the long way, since TYPE_METHOD_BASETYPE
704 is just the main variant of this. */
705 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
706 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
709 /* If this was a member function type, get back to the
710 original type of type member function (i.e., without
711 the class instance variable up front. */
712 t1 = build_function_type (TREE_TYPE (t1),
713 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
714 t2 = build_function_type (TREE_TYPE (t2),
715 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
716 t3 = merge_types (t1, t2);
717 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
718 TYPE_ARG_TYPES (t3));
719 t1 = build_exception_variant (t3, raises);
724 /* There is no need to merge attributes into a TYPENAME_TYPE.
725 When the type is instantiated it will have whatever
726 attributes result from the instantiation. */
731 return cp_build_type_attribute_variant (t1, attributes);
734 /* Return the common type of two types.
735 We assume that comptypes has already been done and returned 1;
736 if that isn't so, this may crash.
738 This is the type for the result of most arithmetic operations
739 if the operands have the given two types. */
742 common_type (tree t1, tree t2)
744 enum tree_code code1;
745 enum tree_code code2;
747 /* If one type is nonsense, bail. */
748 if (t1 == error_mark_node || t2 == error_mark_node)
749 return error_mark_node;
751 code1 = TREE_CODE (t1);
752 code2 = TREE_CODE (t2);
754 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
755 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
756 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
757 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
758 return type_after_usual_arithmetic_conversions (t1, t2);
760 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
761 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
762 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
763 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
769 /* Compare two exception specifier types for exactness or subsetness, if
770 allowed. Returns false for mismatch, true for match (same, or
773 [except.spec] "If a class X ... objects of class X or any class publicly
774 and unambiguously derived from X. Similarly, if a pointer type Y * ...
775 exceptions of type Y * or that are pointers to any type publicly and
776 unambiguously derived from Y. Otherwise a function only allows exceptions
777 that have the same type ..."
778 This does not mention cv qualifiers and is different to what throw
779 [except.throw] and catch [except.catch] will do. They will ignore the
780 top level cv qualifiers, and allow qualifiers in the pointer to class
783 We implement the letter of the standard. */
786 comp_except_types (tree a, tree b, bool exact)
788 if (same_type_p (a, b))
792 if (cp_type_quals (a) || cp_type_quals (b))
795 if (TREE_CODE (a) == POINTER_TYPE
796 && TREE_CODE (b) == POINTER_TYPE)
800 if (cp_type_quals (a) || cp_type_quals (b))
804 if (TREE_CODE (a) != RECORD_TYPE
805 || TREE_CODE (b) != RECORD_TYPE)
808 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
814 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
815 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
816 otherwise it must be exact. Exception lists are unordered, but
817 we've already filtered out duplicates. Most lists will be in order,
818 we should try to make use of that. */
821 comp_except_specs (tree t1, tree t2, bool exact)
830 if (t1 == NULL_TREE) /* T1 is ... */
831 return t2 == NULL_TREE || !exact;
832 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
833 return t2 != NULL_TREE && !TREE_VALUE (t2);
834 if (t2 == NULL_TREE) /* T2 is ... */
836 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
839 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
840 Count how many we find, to determine exactness. For exact matching and
841 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
843 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
845 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
847 tree a = TREE_VALUE (probe);
848 tree b = TREE_VALUE (t2);
850 if (comp_except_types (a, b, exact))
852 if (probe == base && exact)
853 base = TREE_CHAIN (probe);
858 if (probe == NULL_TREE)
861 return !exact || base == NULL_TREE || length == list_length (t1);
864 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
865 [] can match [size]. */
868 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
877 /* The type of the array elements must be the same. */
878 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
881 d1 = TYPE_DOMAIN (t1);
882 d2 = TYPE_DOMAIN (t2);
887 /* If one of the arrays is dimensionless, and the other has a
888 dimension, they are of different types. However, it is valid to
896 declarations for an array object can specify
897 array types that differ by the presence or absence of a major
898 array bound (_dcl.array_). */
900 return allow_redeclaration;
902 /* Check that the dimensions are the same. */
904 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
906 max1 = TYPE_MAX_VALUE (d1);
907 max2 = TYPE_MAX_VALUE (d2);
908 if (processing_template_decl && !abi_version_at_least (2)
909 && !value_dependent_expression_p (max1)
910 && !value_dependent_expression_p (max2))
912 /* With abi-1 we do not fold non-dependent array bounds, (and
913 consequently mangle them incorrectly). We must therefore
914 fold them here, to verify the domains have the same
920 if (!cp_tree_equal (max1, max2))
926 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
927 is a bitwise-or of the COMPARE_* flags. */
930 comptypes (tree t1, tree t2, int strict)
935 /* Suppress errors caused by previously reported errors. */
936 if (t1 == error_mark_node || t2 == error_mark_node)
939 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
941 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
942 current instantiation. */
943 if (TREE_CODE (t1) == TYPENAME_TYPE)
945 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
947 if (resolved != error_mark_node)
951 if (TREE_CODE (t2) == TYPENAME_TYPE)
953 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
955 if (resolved != error_mark_node)
959 /* If either type is the internal version of sizetype, use the
961 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
962 && TYPE_ORIG_SIZE_TYPE (t1))
963 t1 = TYPE_ORIG_SIZE_TYPE (t1);
965 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
966 && TYPE_ORIG_SIZE_TYPE (t2))
967 t2 = TYPE_ORIG_SIZE_TYPE (t2);
969 if (TYPE_PTRMEMFUNC_P (t1))
970 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
971 if (TYPE_PTRMEMFUNC_P (t2))
972 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
974 /* Different classes of types can't be compatible. */
975 if (TREE_CODE (t1) != TREE_CODE (t2))
978 /* Qualifiers must match. For array types, we will check when we
979 recur on the array element types. */
980 if (TREE_CODE (t1) != ARRAY_TYPE
981 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
983 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
986 /* Allow for two different type nodes which have essentially the same
987 definition. Note that we already checked for equality of the type
988 qualifiers (just above). */
990 if (TREE_CODE (t1) != ARRAY_TYPE
991 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
994 /* Compare the types. Break out if they could be the same. */
995 switch (TREE_CODE (t1))
997 case TEMPLATE_TEMPLATE_PARM:
998 case BOUND_TEMPLATE_TEMPLATE_PARM:
999 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1000 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1002 if (!comp_template_parms
1003 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1004 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1006 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1008 /* Don't check inheritance. */
1009 strict = COMPARE_STRICT;
1014 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1015 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1016 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1017 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1020 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1022 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1028 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1029 strict & ~COMPARE_REDECLARATION))
1031 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1036 case REFERENCE_TYPE:
1037 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1038 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1039 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1045 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1047 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1052 /* Target types must match incl. qualifiers. */
1053 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1057 case TEMPLATE_TYPE_PARM:
1058 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1059 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1064 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1065 TYPENAME_TYPE_FULLNAME (t2)))
1067 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1071 case UNBOUND_CLASS_TEMPLATE:
1072 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1074 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1079 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1084 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1085 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1093 /* If we get here, we know that from a target independent POV the
1094 types are the same. Make sure the target attributes are also
1096 return targetm.comp_type_attributes (t1, t2);
1099 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1102 at_least_as_qualified_p (tree type1, tree type2)
1104 int q1 = cp_type_quals (type1);
1105 int q2 = cp_type_quals (type2);
1107 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1108 return (q1 & q2) == q2;
1111 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1112 more cv-qualified that TYPE1, and 0 otherwise. */
1115 comp_cv_qualification (tree type1, tree type2)
1117 int q1 = cp_type_quals (type1);
1118 int q2 = cp_type_quals (type2);
1123 if ((q1 & q2) == q2)
1125 else if ((q1 & q2) == q1)
1131 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1132 subset of the cv-qualification signature of TYPE2, and the types
1133 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1136 comp_cv_qual_signature (tree type1, tree type2)
1138 if (comp_ptr_ttypes_real (type2, type1, -1))
1140 else if (comp_ptr_ttypes_real (type1, type2, -1))
1146 /* If two types share a common base type, return that basetype.
1147 If there is not a unique most-derived base type, this function
1148 returns ERROR_MARK_NODE. */
1151 common_base_type (tree tt1, tree tt2)
1153 tree best = NULL_TREE;
1156 /* If one is a baseclass of another, that's good enough. */
1157 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1159 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1162 /* Otherwise, try to find a unique baseclass of TT1
1163 that is shared by TT2, and follow that down. */
1164 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1166 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1167 tree trial = common_base_type (basetype, tt2);
1171 if (trial == error_mark_node)
1173 if (best == NULL_TREE)
1175 else if (best != trial)
1176 return error_mark_node;
1181 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1183 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1184 tree trial = common_base_type (tt1, basetype);
1188 if (trial == error_mark_node)
1190 if (best == NULL_TREE)
1192 else if (best != trial)
1193 return error_mark_node;
1199 /* Subroutines of `comptypes'. */
1201 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1202 equivalent in the sense that functions with those parameter types
1203 can have equivalent types. The two lists must be equivalent,
1204 element by element. */
1207 compparms (tree parms1, tree parms2)
1211 /* An unspecified parmlist matches any specified parmlist
1212 whose argument types don't need default promotions. */
1214 for (t1 = parms1, t2 = parms2;
1216 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1218 /* If one parmlist is shorter than the other,
1219 they fail to match. */
1222 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1229 /* Process a sizeof or alignof expression where the operand is a
1233 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1235 enum tree_code type_code;
1237 const char *op_name;
1239 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1240 if (type == error_mark_node)
1241 return error_mark_node;
1243 if (dependent_type_p (type))
1245 value = build_min (op, size_type_node, type);
1246 TREE_READONLY (value) = 1;
1250 op_name = operator_name_info[(int) op].name;
1252 type = non_reference (type);
1253 type_code = TREE_CODE (type);
1255 if (type_code == METHOD_TYPE)
1257 if (complain && (pedantic || warn_pointer_arith))
1258 pedwarn ("invalid application of %qs to a member function", op_name);
1259 value = size_one_node;
1262 value = c_sizeof_or_alignof_type (complete_type (type),
1269 /* Process a sizeof or alignof expression where the operand is an
1273 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1275 const char *op_name = operator_name_info[(int) op].name;
1277 if (e == error_mark_node)
1278 return error_mark_node;
1280 if (processing_template_decl)
1282 e = build_min (op, size_type_node, e);
1283 TREE_SIDE_EFFECTS (e) = 0;
1284 TREE_READONLY (e) = 1;
1289 if (TREE_CODE (e) == COMPONENT_REF
1290 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1291 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1293 error ("invalid application of %qs to a bit-field", op_name);
1296 else if (is_overloaded_fn (e))
1298 pedwarn ("ISO C++ forbids applying %qs to an expression of "
1299 "function type", op_name);
1302 else if (type_unknown_p (e))
1304 cxx_incomplete_type_error (e, TREE_TYPE (e));
1310 return cxx_sizeof_or_alignof_type (e, op, true);
1314 /* EXPR is being used in a context that is not a function call.
1319 The expression can be used only as the left-hand operand of a
1320 member function call.
1322 [expr.mptr.operator]
1324 If the result of .* or ->* is a function, then that result can be
1325 used only as the operand for the function call operator ().
1327 by issuing an error message if appropriate. Returns true iff EXPR
1328 violates these rules. */
1331 invalid_nonstatic_memfn_p (tree expr)
1333 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1335 error ("invalid use of non-static member function");
1341 /* Perform the conversions in [expr] that apply when an lvalue appears
1342 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1343 function-to-pointer conversions.
1345 In addition manifest constants are replaced by their values. */
1348 decay_conversion (tree exp)
1351 enum tree_code code;
1353 type = TREE_TYPE (exp);
1354 code = TREE_CODE (type);
1356 if (type == error_mark_node)
1357 return error_mark_node;
1359 if (type_unknown_p (exp))
1361 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1362 return error_mark_node;
1365 exp = decl_constant_value (exp);
1367 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1368 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1370 if (code == VOID_TYPE)
1372 error ("void value not ignored as it ought to be");
1373 return error_mark_node;
1375 if (invalid_nonstatic_memfn_p (exp))
1376 return error_mark_node;
1377 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1378 return build_unary_op (ADDR_EXPR, exp, 0);
1379 if (code == ARRAY_TYPE)
1384 if (TREE_CODE (exp) == INDIRECT_REF)
1385 return build_nop (build_pointer_type (TREE_TYPE (type)),
1386 TREE_OPERAND (exp, 0));
1388 if (TREE_CODE (exp) == COMPOUND_EXPR)
1390 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1391 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1392 TREE_OPERAND (exp, 0), op1);
1396 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1398 error ("invalid use of non-lvalue array");
1399 return error_mark_node;
1402 ptrtype = build_pointer_type (TREE_TYPE (type));
1404 if (TREE_CODE (exp) == VAR_DECL)
1406 if (!cxx_mark_addressable (exp))
1407 return error_mark_node;
1408 adr = build_nop (ptrtype, build_address (exp));
1411 /* This way is better for a COMPONENT_REF since it can
1412 simplify the offset for a component. */
1413 adr = build_unary_op (ADDR_EXPR, exp, 1);
1414 return cp_convert (ptrtype, adr);
1417 /* [basic.lval]: Class rvalues can have cv-qualified types; non-class
1418 rvalues always have cv-unqualified types. */
1419 if (! CLASS_TYPE_P (type))
1420 exp = cp_convert (TYPE_MAIN_VARIANT (type), exp);
1426 default_conversion (tree exp)
1428 exp = decay_conversion (exp);
1430 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1431 exp = perform_integral_promotions (exp);
1436 /* EXPR is an expression with an integral or enumeration type.
1437 Perform the integral promotions in [conv.prom], and return the
1441 perform_integral_promotions (tree expr)
1446 type = TREE_TYPE (expr);
1447 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1448 promoted_type = type_promotes_to (type);
1449 if (type != promoted_type)
1450 expr = cp_convert (promoted_type, expr);
1454 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1458 inline_conversion (tree exp)
1460 if (TREE_CODE (exp) == FUNCTION_DECL)
1461 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1466 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1467 decay_conversion to one. */
1470 string_conv_p (tree totype, tree exp, int warn)
1474 if (! flag_const_strings || TREE_CODE (totype) != POINTER_TYPE)
1477 t = TREE_TYPE (totype);
1478 if (!same_type_p (t, char_type_node)
1479 && !same_type_p (t, wchar_type_node))
1482 if (TREE_CODE (exp) == STRING_CST)
1484 /* Make sure that we don't try to convert between char and wchar_t. */
1485 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1490 /* Is this a string constant which has decayed to 'const char *'? */
1491 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1492 if (!same_type_p (TREE_TYPE (exp), t))
1495 if (TREE_CODE (exp) != ADDR_EXPR
1496 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1500 /* This warning is not very useful, as it complains about printf. */
1501 if (warn && warn_write_strings)
1502 warning (0, "deprecated conversion from string constant to %qT'", totype);
1507 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1508 can, for example, use as an lvalue. This code used to be in
1509 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1510 expressions, where we're dealing with aggregates. But now it's again only
1511 called from unary_complex_lvalue. The case (in particular) that led to
1512 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1516 rationalize_conditional_expr (enum tree_code code, tree t)
1518 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1519 the first operand is always the one to be used if both operands
1520 are equal, so we know what conditional expression this used to be. */
1521 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1523 /* The following code is incorrect if either operand side-effects. */
1524 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1525 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1527 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1528 ? LE_EXPR : GE_EXPR),
1529 TREE_OPERAND (t, 0),
1530 TREE_OPERAND (t, 1),
1531 /*overloaded_p=*/NULL),
1532 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1533 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1537 build_conditional_expr (TREE_OPERAND (t, 0),
1538 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1539 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1542 /* Given the TYPE of an anonymous union field inside T, return the
1543 FIELD_DECL for the field. If not found return NULL_TREE. Because
1544 anonymous unions can nest, we must also search all anonymous unions
1545 that are directly reachable. */
1548 lookup_anon_field (tree t, tree type)
1552 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1554 if (TREE_STATIC (field))
1556 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1559 /* If we find it directly, return the field. */
1560 if (DECL_NAME (field) == NULL_TREE
1561 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1566 /* Otherwise, it could be nested, search harder. */
1567 if (DECL_NAME (field) == NULL_TREE
1568 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1570 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1578 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1579 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1580 non-NULL, it indicates the path to the base used to name MEMBER.
1581 If PRESERVE_REFERENCE is true, the expression returned will have
1582 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1583 returned will have the type referred to by the reference.
1585 This function does not perform access control; that is either done
1586 earlier by the parser when the name of MEMBER is resolved to MEMBER
1587 itself, or later when overload resolution selects one of the
1588 functions indicated by MEMBER. */
1591 build_class_member_access_expr (tree object, tree member,
1592 tree access_path, bool preserve_reference)
1596 tree result = NULL_TREE;
1598 if (object == error_mark_node || member == error_mark_node)
1599 return error_mark_node;
1601 gcc_assert (DECL_P (member) || BASELINK_P (member));
1605 The type of the first expression shall be "class object" (of a
1607 object_type = TREE_TYPE (object);
1608 if (!currently_open_class (object_type)
1609 && !complete_type_or_else (object_type, object))
1610 return error_mark_node;
1611 if (!CLASS_TYPE_P (object_type))
1613 error ("request for member %qD in %qE, which is of non-class type %qT",
1614 member, object, object_type);
1615 return error_mark_node;
1618 /* The standard does not seem to actually say that MEMBER must be a
1619 member of OBJECT_TYPE. However, that is clearly what is
1621 if (DECL_P (member))
1623 member_scope = DECL_CLASS_CONTEXT (member);
1625 if (TREE_DEPRECATED (member))
1626 warn_deprecated_use (member);
1629 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1630 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1631 presently be the anonymous union. Go outwards until we find a
1632 type related to OBJECT_TYPE. */
1633 while (ANON_AGGR_TYPE_P (member_scope)
1634 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1636 member_scope = TYPE_CONTEXT (member_scope);
1637 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1639 if (TREE_CODE (member) == FIELD_DECL)
1640 error ("invalid use of nonstatic data member %qE", member);
1642 error ("%qD is not a member of %qT", member, object_type);
1643 return error_mark_node;
1646 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1647 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1648 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1650 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1652 object = build_indirect_ref (temp, NULL);
1655 /* In [expr.ref], there is an explicit list of the valid choices for
1656 MEMBER. We check for each of those cases here. */
1657 if (TREE_CODE (member) == VAR_DECL)
1659 /* A static data member. */
1661 /* If OBJECT has side-effects, they are supposed to occur. */
1662 if (TREE_SIDE_EFFECTS (object))
1663 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1665 else if (TREE_CODE (member) == FIELD_DECL)
1667 /* A non-static data member. */
1672 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1673 && integer_zerop (TREE_OPERAND (object, 0)));
1675 /* Convert OBJECT to the type of MEMBER. */
1676 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1677 TYPE_MAIN_VARIANT (member_scope)))
1682 binfo = lookup_base (access_path ? access_path : object_type,
1683 member_scope, ba_unique, &kind);
1684 if (binfo == error_mark_node)
1685 return error_mark_node;
1687 /* It is invalid to try to get to a virtual base of a
1688 NULL object. The most common cause is invalid use of
1690 if (null_object_p && kind == bk_via_virtual)
1692 error ("invalid access to non-static data member %qD of "
1695 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1696 return error_mark_node;
1699 /* Convert to the base. */
1700 object = build_base_path (PLUS_EXPR, object, binfo,
1702 /* If we found the base successfully then we should be able
1703 to convert to it successfully. */
1704 gcc_assert (object != error_mark_node);
1707 /* Complain about other invalid uses of offsetof, even though they will
1708 give the right answer. Note that we complain whether or not they
1709 actually used the offsetof macro, since there's no way to know at this
1710 point. So we just give a warning, instead of a pedwarn. */
1711 /* Do not produce this warning for base class field references, because
1712 we know for a fact that didn't come from offsetof. This does occur
1713 in various testsuite cases where a null object is passed where a
1714 vtable access is required. */
1715 if (null_object_p && warn_invalid_offsetof
1716 && CLASSTYPE_NON_POD_P (object_type)
1717 && !DECL_FIELD_IS_BASE (member)
1718 && !skip_evaluation)
1720 warning (0, "invalid access to non-static data member %qD of NULL object",
1722 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1725 /* If MEMBER is from an anonymous aggregate, we have converted
1726 OBJECT so that it refers to the class containing the
1727 anonymous union. Generate a reference to the anonymous union
1728 itself, and recur to find MEMBER. */
1729 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1730 /* When this code is called from build_field_call, the
1731 object already has the type of the anonymous union.
1732 That is because the COMPONENT_REF was already
1733 constructed, and was then disassembled before calling
1734 build_field_call. After the function-call code is
1735 cleaned up, this waste can be eliminated. */
1736 && (!same_type_ignoring_top_level_qualifiers_p
1737 (TREE_TYPE (object), DECL_CONTEXT (member))))
1739 tree anonymous_union;
1741 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1742 DECL_CONTEXT (member));
1743 object = build_class_member_access_expr (object,
1745 /*access_path=*/NULL_TREE,
1746 preserve_reference);
1749 /* Compute the type of the field, as described in [expr.ref]. */
1750 type_quals = TYPE_UNQUALIFIED;
1751 member_type = TREE_TYPE (member);
1752 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1754 type_quals = (cp_type_quals (member_type)
1755 | cp_type_quals (object_type));
1757 /* A field is const (volatile) if the enclosing object, or the
1758 field itself, is const (volatile). But, a mutable field is
1759 not const, even within a const object. */
1760 if (DECL_MUTABLE_P (member))
1761 type_quals &= ~TYPE_QUAL_CONST;
1762 member_type = cp_build_qualified_type (member_type, type_quals);
1765 result = build3 (COMPONENT_REF, member_type, object, member,
1767 result = fold_if_not_in_template (result);
1769 /* Mark the expression const or volatile, as appropriate. Even
1770 though we've dealt with the type above, we still have to mark the
1771 expression itself. */
1772 if (type_quals & TYPE_QUAL_CONST)
1773 TREE_READONLY (result) = 1;
1774 if (type_quals & TYPE_QUAL_VOLATILE)
1775 TREE_THIS_VOLATILE (result) = 1;
1777 else if (BASELINK_P (member))
1779 /* The member is a (possibly overloaded) member function. */
1783 /* If the MEMBER is exactly one static member function, then we
1784 know the type of the expression. Otherwise, we must wait
1785 until overload resolution has been performed. */
1786 functions = BASELINK_FUNCTIONS (member);
1787 if (TREE_CODE (functions) == FUNCTION_DECL
1788 && DECL_STATIC_FUNCTION_P (functions))
1789 type = TREE_TYPE (functions);
1791 type = unknown_type_node;
1792 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1793 base. That will happen when the function is called. */
1794 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1796 else if (TREE_CODE (member) == CONST_DECL)
1798 /* The member is an enumerator. */
1800 /* If OBJECT has side-effects, they are supposed to occur. */
1801 if (TREE_SIDE_EFFECTS (object))
1802 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1807 error ("invalid use of %qD", member);
1808 return error_mark_node;
1811 if (!preserve_reference)
1814 If E2 is declared to have type "reference to T", then ... the
1815 type of E1.E2 is T. */
1816 result = convert_from_reference (result);
1821 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1822 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1825 lookup_destructor (tree object, tree scope, tree dtor_name)
1827 tree object_type = TREE_TYPE (object);
1828 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1831 if (scope && !check_dtor_name (scope, dtor_name))
1833 error ("qualified type %qT does not match destructor name ~%qT",
1835 return error_mark_node;
1837 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1839 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1840 TYPE_MAIN_VARIANT (object_type), dtor_type);
1841 return error_mark_node;
1843 expr = lookup_member (dtor_type, complete_dtor_identifier,
1844 /*protect=*/1, /*want_type=*/false);
1845 expr = (adjust_result_of_qualified_name_lookup
1846 (expr, dtor_type, object_type));
1850 /* An expression of the form "A::template B" has been resolved to
1851 DECL. Issue a diagnostic if B is not a template or template
1855 check_template_keyword (tree decl)
1857 /* The standard says:
1861 If a name prefixed by the keyword template is not a member
1862 template, the program is ill-formed.
1864 DR 228 removed the restriction that the template be a member
1867 DR 96, if accepted would add the further restriction that explicit
1868 template arguments must be provided if the template keyword is
1869 used, but, as of 2005-10-16, that DR is still in "drafting". If
1870 this DR is accepted, then the semantic checks here can be
1871 simplified, as the entity named must in fact be a template
1872 specialization, rather than, as at present, a set of overloaded
1873 functions containing at least one template function. */
1874 if (TREE_CODE (decl) != TEMPLATE_DECL
1875 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
1877 if (!is_overloaded_fn (decl))
1878 pedwarn ("%qD is not a template", decl);
1883 if (BASELINK_P (fns))
1884 fns = BASELINK_FUNCTIONS (fns);
1887 tree fn = OVL_CURRENT (fns);
1888 if (TREE_CODE (fn) == TEMPLATE_DECL
1889 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
1891 if (TREE_CODE (fn) == FUNCTION_DECL
1892 && DECL_USE_TEMPLATE (fn)
1893 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
1895 fns = OVL_NEXT (fns);
1898 pedwarn ("%qD is not a template", decl);
1903 /* This function is called by the parser to process a class member
1904 access expression of the form OBJECT.NAME. NAME is a node used by
1905 the parser to represent a name; it is not yet a DECL. It may,
1906 however, be a BASELINK where the BASELINK_FUNCTIONS is a
1907 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
1908 there is no reason to do the lookup twice, so the parser keeps the
1909 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
1910 be a template via the use of the "A::template B" syntax. */
1913 finish_class_member_access_expr (tree object, tree name, bool template_p)
1918 tree access_path = NULL_TREE;
1919 tree orig_object = object;
1920 tree orig_name = name;
1922 if (object == error_mark_node || name == error_mark_node)
1923 return error_mark_node;
1925 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
1926 if (!objc_is_public (object, name))
1927 return error_mark_node;
1929 object_type = TREE_TYPE (object);
1931 if (processing_template_decl)
1933 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
1934 dependent_type_p (object_type)
1935 /* If NAME is just an IDENTIFIER_NODE, then the expression
1937 || TREE_CODE (object) == IDENTIFIER_NODE
1938 /* If NAME is "f<args>", where either 'f' or 'args' is
1939 dependent, then the expression is dependent. */
1940 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
1941 && dependent_template_id_p (TREE_OPERAND (name, 0),
1942 TREE_OPERAND (name, 1)))
1943 /* If NAME is "T::X" where "T" is dependent, then the
1944 expression is dependent. */
1945 || (TREE_CODE (name) == SCOPE_REF
1946 && TYPE_P (TREE_OPERAND (name, 0))
1947 && dependent_type_p (TREE_OPERAND (name, 0))))
1948 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
1949 object = build_non_dependent_expr (object);
1954 The type of the first expression shall be "class object" (of a
1956 if (!currently_open_class (object_type)
1957 && !complete_type_or_else (object_type, object))
1958 return error_mark_node;
1959 if (!CLASS_TYPE_P (object_type))
1961 error ("request for member %qD in %qE, which is of non-class type %qT",
1962 name, object, object_type);
1963 return error_mark_node;
1966 if (BASELINK_P (name))
1967 /* A member function that has already been looked up. */
1971 bool is_template_id = false;
1972 tree template_args = NULL_TREE;
1975 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
1977 is_template_id = true;
1978 template_args = TREE_OPERAND (name, 1);
1979 name = TREE_OPERAND (name, 0);
1981 if (TREE_CODE (name) == OVERLOAD)
1982 name = DECL_NAME (get_first_fn (name));
1983 else if (DECL_P (name))
1984 name = DECL_NAME (name);
1987 if (TREE_CODE (name) == SCOPE_REF)
1989 /* A qualified name. The qualifying class or namespace `S' has
1990 already been looked up; it is either a TYPE or a
1991 NAMESPACE_DECL. The member name is either an IDENTIFIER_NODE
1992 or a BIT_NOT_EXPR. */
1993 scope = TREE_OPERAND (name, 0);
1994 name = TREE_OPERAND (name, 1);
1995 gcc_assert (CLASS_TYPE_P (scope)
1996 || TREE_CODE (scope) == NAMESPACE_DECL);
1997 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
1998 || TREE_CODE (name) == BIT_NOT_EXPR);
2000 /* If SCOPE is a namespace, then the qualified name does not
2001 name a member of OBJECT_TYPE. */
2002 if (TREE_CODE (scope) == NAMESPACE_DECL)
2004 error ("%<%D::%D%> is not a member of %qT",
2005 scope, name, object_type);
2006 return error_mark_node;
2009 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2010 access_path = lookup_base (object_type, scope, ba_check, NULL);
2011 if (access_path == error_mark_node)
2012 return error_mark_node;
2015 error ("%qT is not a base of %qT", scope, object_type);
2016 return error_mark_node;
2022 access_path = object_type;
2025 if (TREE_CODE (name) == BIT_NOT_EXPR)
2026 member = lookup_destructor (object, scope, name);
2029 /* Look up the member. */
2030 member = lookup_member (access_path, name, /*protect=*/1,
2031 /*want_type=*/false);
2032 if (member == NULL_TREE)
2034 error ("%qD has no member named %qE", object_type, name);
2035 return error_mark_node;
2037 if (member == error_mark_node)
2038 return error_mark_node;
2043 tree template = member;
2045 if (BASELINK_P (template))
2046 template = lookup_template_function (template, template_args);
2049 error ("%qD is not a member template function", name);
2050 return error_mark_node;
2055 if (TREE_DEPRECATED (member))
2056 warn_deprecated_use (member);
2059 check_template_keyword (member);
2061 expr = build_class_member_access_expr (object, member, access_path,
2062 /*preserve_reference=*/false);
2063 if (processing_template_decl && expr != error_mark_node)
2065 if (BASELINK_P (member))
2067 if (TREE_CODE (orig_name) == SCOPE_REF)
2068 BASELINK_QUALIFIED_P (member) = 1;
2071 return build_min_non_dep (COMPONENT_REF, expr,
2072 orig_object, orig_name,
2079 /* Return an expression for the MEMBER_NAME field in the internal
2080 representation of PTRMEM, a pointer-to-member function. (Each
2081 pointer-to-member function type gets its own RECORD_TYPE so it is
2082 more convenient to access the fields by name than by FIELD_DECL.)
2083 This routine converts the NAME to a FIELD_DECL and then creates the
2084 node for the complete expression. */
2087 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2093 /* This code is a stripped down version of
2094 build_class_member_access_expr. It does not work to use that
2095 routine directly because it expects the object to be of class
2097 ptrmem_type = TREE_TYPE (ptrmem);
2098 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2099 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2100 /*want_type=*/false);
2101 member_type = cp_build_qualified_type (TREE_TYPE (member),
2102 cp_type_quals (ptrmem_type));
2103 return fold_build3 (COMPONENT_REF, member_type,
2104 ptrmem, member, NULL_TREE);
2107 /* Given an expression PTR for a pointer, return an expression
2108 for the value pointed to.
2109 ERRORSTRING is the name of the operator to appear in error messages.
2111 This function may need to overload OPERATOR_FNNAME.
2112 Must also handle REFERENCE_TYPEs for C++. */
2115 build_x_indirect_ref (tree expr, const char *errorstring)
2117 tree orig_expr = expr;
2120 if (processing_template_decl)
2122 if (type_dependent_expression_p (expr))
2123 return build_min_nt (INDIRECT_REF, expr);
2124 expr = build_non_dependent_expr (expr);
2127 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2128 NULL_TREE, /*overloaded_p=*/NULL);
2130 rval = build_indirect_ref (expr, errorstring);
2132 if (processing_template_decl && rval != error_mark_node)
2133 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2139 build_indirect_ref (tree ptr, const char *errorstring)
2143 if (ptr == error_mark_node)
2144 return error_mark_node;
2146 if (ptr == current_class_ptr)
2147 return current_class_ref;
2149 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2150 ? ptr : decay_conversion (ptr));
2151 type = TREE_TYPE (pointer);
2153 if (POINTER_TYPE_P (type))
2157 If the type of the expression is "pointer to T," the type
2158 of the result is "T."
2160 We must use the canonical variant because certain parts of
2161 the back end, like fold, do pointer comparisons between
2163 tree t = canonical_type_variant (TREE_TYPE (type));
2165 if (VOID_TYPE_P (t))
2167 /* A pointer to incomplete type (other than cv void) can be
2168 dereferenced [expr.unary.op]/1 */
2169 error ("%qT is not a pointer-to-object type", type);
2170 return error_mark_node;
2172 else if (TREE_CODE (pointer) == ADDR_EXPR
2173 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2174 /* The POINTER was something like `&x'. We simplify `*&x' to
2176 return TREE_OPERAND (pointer, 0);
2179 tree ref = build1 (INDIRECT_REF, t, pointer);
2181 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2182 so that we get the proper error message if the result is used
2183 to assign to. Also, &* is supposed to be a no-op. */
2184 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2185 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2186 TREE_SIDE_EFFECTS (ref)
2187 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2191 /* `pointer' won't be an error_mark_node if we were given a
2192 pointer to member, so it's cool to check for this here. */
2193 else if (TYPE_PTR_TO_MEMBER_P (type))
2194 error ("invalid use of %qs on pointer to member", errorstring);
2195 else if (pointer != error_mark_node)
2198 error ("invalid type argument of %qs", errorstring);
2200 error ("invalid type argument");
2202 return error_mark_node;
2205 /* This handles expressions of the form "a[i]", which denotes
2208 This is logically equivalent in C to *(a+i), but we may do it differently.
2209 If A is a variable or a member, we generate a primitive ARRAY_REF.
2210 This avoids forcing the array out of registers, and can work on
2211 arrays that are not lvalues (for example, members of structures returned
2214 If INDEX is of some user-defined type, it must be converted to
2215 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2216 will inherit the type of the array, which will be some pointer type. */
2219 build_array_ref (tree array, tree idx)
2223 error ("subscript missing in array reference");
2224 return error_mark_node;
2227 if (TREE_TYPE (array) == error_mark_node
2228 || TREE_TYPE (idx) == error_mark_node)
2229 return error_mark_node;
2231 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2233 switch (TREE_CODE (array))
2237 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2238 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2239 TREE_OPERAND (array, 0), value);
2243 return build_conditional_expr
2244 (TREE_OPERAND (array, 0),
2245 build_array_ref (TREE_OPERAND (array, 1), idx),
2246 build_array_ref (TREE_OPERAND (array, 2), idx));
2252 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2256 warn_array_subscript_with_type_char (idx);
2258 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2260 error ("array subscript is not an integer");
2261 return error_mark_node;
2264 /* Apply integral promotions *after* noticing character types.
2265 (It is unclear why we do these promotions -- the standard
2266 does not say that we should. In fact, the natural thing would
2267 seem to be to convert IDX to ptrdiff_t; we're performing
2268 pointer arithmetic.) */
2269 idx = perform_integral_promotions (idx);
2271 /* An array that is indexed by a non-constant
2272 cannot be stored in a register; we must be able to do
2273 address arithmetic on its address.
2274 Likewise an array of elements of variable size. */
2275 if (TREE_CODE (idx) != INTEGER_CST
2276 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2277 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2280 if (!cxx_mark_addressable (array))
2281 return error_mark_node;
2284 /* An array that is indexed by a constant value which is not within
2285 the array bounds cannot be stored in a register either; because we
2286 would get a crash in store_bit_field/extract_bit_field when trying
2287 to access a non-existent part of the register. */
2288 if (TREE_CODE (idx) == INTEGER_CST
2289 && TYPE_DOMAIN (TREE_TYPE (array))
2290 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2292 if (!cxx_mark_addressable (array))
2293 return error_mark_node;
2296 if (pedantic && !lvalue_p (array))
2297 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2299 /* Note in C++ it is valid to subscript a `register' array, since
2300 it is valid to take the address of something with that
2301 storage specification. */
2305 while (TREE_CODE (foo) == COMPONENT_REF)
2306 foo = TREE_OPERAND (foo, 0);
2307 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2308 warning (0, "subscripting array declared %<register%>");
2311 type = TREE_TYPE (TREE_TYPE (array));
2312 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2313 /* Array ref is const/volatile if the array elements are
2314 or if the array is.. */
2315 TREE_READONLY (rval)
2316 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2317 TREE_SIDE_EFFECTS (rval)
2318 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2319 TREE_THIS_VOLATILE (rval)
2320 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2321 return require_complete_type (fold_if_not_in_template (rval));
2325 tree ar = default_conversion (array);
2326 tree ind = default_conversion (idx);
2328 /* Put the integer in IND to simplify error checking. */
2329 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2336 if (ar == error_mark_node)
2339 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2341 error ("subscripted value is neither array nor pointer");
2342 return error_mark_node;
2344 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2346 error ("array subscript is not an integer");
2347 return error_mark_node;
2350 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2355 /* Resolve a pointer to member function. INSTANCE is the object
2356 instance to use, if the member points to a virtual member.
2358 This used to avoid checking for virtual functions if basetype
2359 has no virtual functions, according to an earlier ANSI draft.
2360 With the final ISO C++ rules, such an optimization is
2361 incorrect: A pointer to a derived member can be static_cast
2362 to pointer-to-base-member, as long as the dynamic object
2363 later has the right member. */
2366 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2368 if (TREE_CODE (function) == OFFSET_REF)
2369 function = TREE_OPERAND (function, 1);
2371 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2373 tree idx, delta, e1, e2, e3, vtbl, basetype;
2374 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2376 tree instance_ptr = *instance_ptrptr;
2377 tree instance_save_expr = 0;
2378 if (instance_ptr == error_mark_node)
2380 if (TREE_CODE (function) == PTRMEM_CST)
2382 /* Extracting the function address from a pmf is only
2383 allowed with -Wno-pmf-conversions. It only works for
2385 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2386 e1 = convert (fntype, e1);
2391 error ("object missing in use of %qE", function);
2392 return error_mark_node;
2396 if (TREE_SIDE_EFFECTS (instance_ptr))
2397 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2399 if (TREE_SIDE_EFFECTS (function))
2400 function = save_expr (function);
2402 /* Start by extracting all the information from the PMF itself. */
2403 e3 = pfn_from_ptrmemfunc (function);
2404 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2405 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2406 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2408 case ptrmemfunc_vbit_in_pfn:
2409 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2410 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2413 case ptrmemfunc_vbit_in_delta:
2414 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2415 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2422 /* Convert down to the right base before using the instance. A
2423 special case is that in a pointer to member of class C, C may
2424 be incomplete. In that case, the function will of course be
2425 a member of C, and no conversion is required. In fact,
2426 lookup_base will fail in that case, because incomplete
2427 classes do not have BINFOs. */
2428 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2429 if (!same_type_ignoring_top_level_qualifiers_p
2430 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2432 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2433 basetype, ba_check, NULL);
2434 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2436 if (instance_ptr == error_mark_node)
2437 return error_mark_node;
2439 /* ...and then the delta in the PMF. */
2440 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2441 instance_ptr, delta);
2443 /* Hand back the adjusted 'this' argument to our caller. */
2444 *instance_ptrptr = instance_ptr;
2446 /* Next extract the vtable pointer from the object. */
2447 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2449 vtbl = build_indirect_ref (vtbl, NULL);
2451 /* Finally, extract the function pointer from the vtable. */
2452 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2453 e2 = build_indirect_ref (e2, NULL);
2454 TREE_CONSTANT (e2) = 1;
2455 TREE_INVARIANT (e2) = 1;
2457 /* When using function descriptors, the address of the
2458 vtable entry is treated as a function pointer. */
2459 if (TARGET_VTABLE_USES_DESCRIPTORS)
2460 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2461 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2463 TREE_TYPE (e2) = TREE_TYPE (e3);
2464 e1 = build_conditional_expr (e1, e2, e3);
2466 /* Make sure this doesn't get evaluated first inside one of the
2467 branches of the COND_EXPR. */
2468 if (instance_save_expr)
2469 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2470 instance_save_expr, e1);
2478 build_function_call (tree function, tree params)
2480 tree fntype, fndecl;
2481 tree coerced_params;
2482 tree name = NULL_TREE;
2484 tree original = function;
2486 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2487 expressions, like those used for ObjC messenger dispatches. */
2488 function = objc_rewrite_function_call (function, params);
2490 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2491 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2492 if (TREE_CODE (function) == NOP_EXPR
2493 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2494 function = TREE_OPERAND (function, 0);
2496 if (TREE_CODE (function) == FUNCTION_DECL)
2498 name = DECL_NAME (function);
2500 mark_used (function);
2503 /* Convert anything with function type to a pointer-to-function. */
2504 if (pedantic && DECL_MAIN_P (function))
2505 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2507 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2508 (because calling an inline function does not mean the function
2509 needs to be separately compiled). */
2511 if (DECL_INLINE (function))
2512 function = inline_conversion (function);
2514 function = build_addr_func (function);
2520 function = build_addr_func (function);
2523 if (function == error_mark_node)
2524 return error_mark_node;
2526 fntype = TREE_TYPE (function);
2528 if (TYPE_PTRMEMFUNC_P (fntype))
2530 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2531 "function in %<%E (...)%>",
2533 return error_mark_node;
2536 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2537 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2539 if (!((TREE_CODE (fntype) == POINTER_TYPE
2540 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2542 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2544 error ("%qE cannot be used as a function", original);
2545 return error_mark_node;
2548 /* fntype now gets the type of function pointed to. */
2549 fntype = TREE_TYPE (fntype);
2551 /* Convert the parameters to the types declared in the
2552 function prototype, or apply default promotions. */
2554 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2555 params, fndecl, LOOKUP_NORMAL);
2556 if (coerced_params == error_mark_node)
2557 return error_mark_node;
2559 /* Check for errors in format strings and inappropriately
2562 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2563 TYPE_ARG_TYPES (fntype));
2565 return build_cxx_call (function, coerced_params);
2568 /* Convert the actual parameter expressions in the list VALUES
2569 to the types in the list TYPELIST.
2570 If parmdecls is exhausted, or when an element has NULL as its type,
2571 perform the default conversions.
2573 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2575 This is also where warnings about wrong number of args are generated.
2577 Return a list of expressions for the parameters as converted.
2579 Both VALUES and the returned value are chains of TREE_LIST nodes
2580 with the elements of the list in the TREE_VALUE slots of those nodes.
2582 In C++, unspecified trailing parameters can be filled in with their
2583 default arguments, if such were specified. Do so here. */
2586 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2588 tree typetail, valtail;
2589 tree result = NULL_TREE;
2590 const char *called_thing = 0;
2593 /* Argument passing is always copy-initialization. */
2594 flags |= LOOKUP_ONLYCONVERTING;
2598 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2600 if (DECL_NAME (fndecl) == NULL_TREE
2601 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2602 called_thing = "constructor";
2604 called_thing = "member function";
2607 called_thing = "function";
2610 for (valtail = values, typetail = typelist;
2612 valtail = TREE_CHAIN (valtail), i++)
2614 tree type = typetail ? TREE_VALUE (typetail) : 0;
2615 tree val = TREE_VALUE (valtail);
2617 if (val == error_mark_node)
2618 return error_mark_node;
2620 if (type == void_type_node)
2624 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2625 error ("at this point in file");
2628 error ("too many arguments to function");
2629 /* In case anybody wants to know if this argument
2632 TREE_TYPE (tree_last (result)) = error_mark_node;
2636 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2637 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2638 if (TREE_CODE (val) == NOP_EXPR
2639 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2640 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2641 val = TREE_OPERAND (val, 0);
2643 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2645 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2646 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2647 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2648 val = decay_conversion (val);
2651 if (val == error_mark_node)
2652 return error_mark_node;
2656 /* Formal parm type is specified by a function prototype. */
2659 if (!COMPLETE_TYPE_P (complete_type (type)))
2662 error ("parameter %P of %qD has incomplete type %qT",
2665 error ("parameter %P has incomplete type %qT", i, type);
2666 parmval = error_mark_node;
2670 parmval = convert_for_initialization
2671 (NULL_TREE, type, val, flags,
2672 "argument passing", fndecl, i);
2673 parmval = convert_for_arg_passing (type, parmval);
2676 if (parmval == error_mark_node)
2677 return error_mark_node;
2679 result = tree_cons (NULL_TREE, parmval, result);
2683 if (fndecl && DECL_BUILT_IN (fndecl)
2684 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2685 /* Don't do ellipsis conversion for __built_in_constant_p
2686 as this will result in spurious warnings for non-POD
2688 val = require_complete_type (val);
2690 val = convert_arg_to_ellipsis (val);
2692 result = tree_cons (NULL_TREE, val, result);
2696 typetail = TREE_CHAIN (typetail);
2699 if (typetail != 0 && typetail != void_list_node)
2701 /* See if there are default arguments that can be used. */
2702 if (TREE_PURPOSE (typetail)
2703 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2705 for (; typetail != void_list_node; ++i)
2708 = convert_default_arg (TREE_VALUE (typetail),
2709 TREE_PURPOSE (typetail),
2712 if (parmval == error_mark_node)
2713 return error_mark_node;
2715 result = tree_cons (0, parmval, result);
2716 typetail = TREE_CHAIN (typetail);
2717 /* ends with `...'. */
2718 if (typetail == NULL_TREE)
2726 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2727 error ("at this point in file");
2730 error ("too few arguments to function");
2731 return error_mark_list;
2735 return nreverse (result);
2738 /* Build a binary-operation expression, after performing default
2739 conversions on the operands. CODE is the kind of expression to build. */
2742 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2752 if (processing_template_decl)
2754 if (type_dependent_expression_p (arg1)
2755 || type_dependent_expression_p (arg2))
2756 return build_min_nt (code, arg1, arg2);
2757 arg1 = build_non_dependent_expr (arg1);
2758 arg2 = build_non_dependent_expr (arg2);
2761 if (code == DOTSTAR_EXPR)
2762 expr = build_m_component_ref (arg1, arg2);
2764 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2767 if (processing_template_decl && expr != error_mark_node)
2768 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2773 /* Build a binary-operation expression without default conversions.
2774 CODE is the kind of expression to build.
2775 This function differs from `build' in several ways:
2776 the data type of the result is computed and recorded in it,
2777 warnings are generated if arg data types are invalid,
2778 special handling for addition and subtraction of pointers is known,
2779 and some optimization is done (operations on narrow ints
2780 are done in the narrower type when that gives the same result).
2781 Constant folding is also done before the result is returned.
2783 Note that the operands will never have enumeral types
2784 because either they have just had the default conversions performed
2785 or they have both just been converted to some other type in which
2786 the arithmetic is to be done.
2788 C++: must do special pointer arithmetic when implementing
2789 multiple inheritance, and deal with pointer to member functions. */
2792 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2793 int convert_p ATTRIBUTE_UNUSED)
2796 enum tree_code code0, code1;
2798 const char *invalid_op_diag;
2800 /* Expression code to give to the expression when it is built.
2801 Normally this is CODE, which is what the caller asked for,
2802 but in some special cases we change it. */
2803 enum tree_code resultcode = code;
2805 /* Data type in which the computation is to be performed.
2806 In the simplest cases this is the common type of the arguments. */
2807 tree result_type = NULL;
2809 /* Nonzero means operands have already been type-converted
2810 in whatever way is necessary.
2811 Zero means they need to be converted to RESULT_TYPE. */
2814 /* Nonzero means create the expression with this type, rather than
2816 tree build_type = 0;
2818 /* Nonzero means after finally constructing the expression
2819 convert it to this type. */
2820 tree final_type = 0;
2824 /* Nonzero if this is an operation like MIN or MAX which can
2825 safely be computed in short if both args are promoted shorts.
2826 Also implies COMMON.
2827 -1 indicates a bitwise operation; this makes a difference
2828 in the exact conditions for when it is safe to do the operation
2829 in a narrower mode. */
2832 /* Nonzero if this is a comparison operation;
2833 if both args are promoted shorts, compare the original shorts.
2834 Also implies COMMON. */
2835 int short_compare = 0;
2837 /* Nonzero if this is a right-shift operation, which can be computed on the
2838 original short and then promoted if the operand is a promoted short. */
2839 int short_shift = 0;
2841 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2844 /* True if both operands have arithmetic type. */
2845 bool arithmetic_types_p;
2847 /* Apply default conversions. */
2851 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2852 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2853 || code == TRUTH_XOR_EXPR)
2855 if (!really_overloaded_fn (op0))
2856 op0 = decay_conversion (op0);
2857 if (!really_overloaded_fn (op1))
2858 op1 = decay_conversion (op1);
2862 if (!really_overloaded_fn (op0))
2863 op0 = default_conversion (op0);
2864 if (!really_overloaded_fn (op1))
2865 op1 = default_conversion (op1);
2868 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2869 STRIP_TYPE_NOPS (op0);
2870 STRIP_TYPE_NOPS (op1);
2872 /* DTRT if one side is an overloaded function, but complain about it. */
2873 if (type_unknown_p (op0))
2875 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2876 if (t != error_mark_node)
2878 pedwarn ("assuming cast to type %qT from overloaded function",
2883 if (type_unknown_p (op1))
2885 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2886 if (t != error_mark_node)
2888 pedwarn ("assuming cast to type %qT from overloaded function",
2894 type0 = TREE_TYPE (op0);
2895 type1 = TREE_TYPE (op1);
2897 /* The expression codes of the data types of the arguments tell us
2898 whether the arguments are integers, floating, pointers, etc. */
2899 code0 = TREE_CODE (type0);
2900 code1 = TREE_CODE (type1);
2902 /* If an error was already reported for one of the arguments,
2903 avoid reporting another error. */
2905 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2906 return error_mark_node;
2908 if ((invalid_op_diag
2909 = targetm.invalid_binary_op (code, type0, type1)))
2911 error (invalid_op_diag);
2912 return error_mark_node;
2918 /* Handle the pointer + int case. */
2919 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2920 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2921 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2922 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2928 /* Subtraction of two similar pointers.
2929 We must subtract them as integers, then divide by object size. */
2930 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2931 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2933 return pointer_diff (op0, op1, common_type (type0, type1));
2934 /* Handle pointer minus int. Just like pointer plus int. */
2935 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2936 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2945 case TRUNC_DIV_EXPR:
2947 case FLOOR_DIV_EXPR:
2948 case ROUND_DIV_EXPR:
2949 case EXACT_DIV_EXPR:
2950 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2951 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2952 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2953 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2955 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2956 warning (0, "division by zero in %<%E / 0%>", op0);
2957 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2958 warning (0, "division by zero in %<%E / 0.%>", op0);
2960 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2961 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2962 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2963 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2965 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2966 resultcode = RDIV_EXPR;
2968 /* When dividing two signed integers, we have to promote to int.
2969 unless we divide by a constant != -1. Note that default
2970 conversion will have been performed on the operands at this
2971 point, so we have to dig out the original type to find out if
2973 shorten = ((TREE_CODE (op0) == NOP_EXPR
2974 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2975 || (TREE_CODE (op1) == INTEGER_CST
2976 && ! integer_all_onesp (op1)));
2985 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2986 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
2990 case TRUNC_MOD_EXPR:
2991 case FLOOR_MOD_EXPR:
2992 if (code1 == INTEGER_TYPE && integer_zerop (op1))
2993 warning (0, "division by zero in %<%E %% 0%>", op0);
2994 else if (code1 == REAL_TYPE && real_zerop (op1))
2995 warning (0, "division by zero in %<%E %% 0.%>", op0);
2997 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2999 /* Although it would be tempting to shorten always here, that loses
3000 on some targets, since the modulo instruction is undefined if the
3001 quotient can't be represented in the computation mode. We shorten
3002 only if unsigned or if dividing by something we know != -1. */
3003 shorten = ((TREE_CODE (op0) == NOP_EXPR
3004 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3005 || (TREE_CODE (op1) == INTEGER_CST
3006 && ! integer_all_onesp (op1)));
3011 case TRUTH_ANDIF_EXPR:
3012 case TRUTH_ORIF_EXPR:
3013 case TRUTH_AND_EXPR:
3015 result_type = boolean_type_node;
3018 /* Shift operations: result has same type as first operand;
3019 always convert second operand to int.
3020 Also set SHORT_SHIFT if shifting rightward. */
3023 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3025 result_type = type0;
3026 if (TREE_CODE (op1) == INTEGER_CST)
3028 if (tree_int_cst_lt (op1, integer_zero_node))
3029 warning (0, "right shift count is negative");
3032 if (! integer_zerop (op1))
3034 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3035 warning (0, "right shift count >= width of type");
3038 /* Convert the shift-count to an integer, regardless of
3039 size of value being shifted. */
3040 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3041 op1 = cp_convert (integer_type_node, op1);
3042 /* Avoid converting op1 to result_type later. */
3048 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3050 result_type = type0;
3051 if (TREE_CODE (op1) == INTEGER_CST)
3053 if (tree_int_cst_lt (op1, integer_zero_node))
3054 warning (0, "left shift count is negative");
3055 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3056 warning (0, "left shift count >= width of type");
3058 /* Convert the shift-count to an integer, regardless of
3059 size of value being shifted. */
3060 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3061 op1 = cp_convert (integer_type_node, op1);
3062 /* Avoid converting op1 to result_type later. */
3069 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3071 result_type = type0;
3072 if (TREE_CODE (op1) == INTEGER_CST)
3074 if (tree_int_cst_lt (op1, integer_zero_node))
3075 warning (0, "%s rotate count is negative",
3076 (code == LROTATE_EXPR) ? "left" : "right");
3077 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3078 warning (0, "%s rotate count >= width of type",
3079 (code == LROTATE_EXPR) ? "left" : "right");
3081 /* Convert the shift-count to an integer, regardless of
3082 size of value being shifted. */
3083 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3084 op1 = cp_convert (integer_type_node, op1);
3090 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3091 warning (0, "comparing floating point with == or != is unsafe");
3092 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3093 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3094 warning (OPT_Wstring_literal_comparison,
3095 "comparison with string literal");
3097 build_type = boolean_type_node;
3098 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3099 || code0 == COMPLEX_TYPE)
3100 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3101 || code1 == COMPLEX_TYPE))
3103 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3104 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3105 result_type = composite_pointer_type (type0, type1, op0, op1,
3107 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3108 && null_ptr_cst_p (op1))
3109 result_type = type0;
3110 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3111 && null_ptr_cst_p (op0))
3112 result_type = type1;
3113 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3115 result_type = type0;
3116 error ("ISO C++ forbids comparison between pointer and integer");
3118 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3120 result_type = type1;
3121 error ("ISO C++ forbids comparison between pointer and integer");
3123 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3125 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3126 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3127 result_type = TREE_TYPE (op0);
3129 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3130 return cp_build_binary_op (code, op1, op0);
3131 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3132 && same_type_p (type0, type1))
3134 /* E will be the final comparison. */
3136 /* E1 and E2 are for scratch. */
3144 if (TREE_SIDE_EFFECTS (op0))
3145 op0 = save_expr (op0);
3146 if (TREE_SIDE_EFFECTS (op1))
3147 op1 = save_expr (op1);
3152 && (!op0.pfn || op0.delta == op1.delta))
3154 The reason for the `!op0.pfn' bit is that a NULL
3155 pointer-to-member is any member with a zero PFN; the
3156 DELTA field is unspecified. */
3157 pfn0 = pfn_from_ptrmemfunc (op0);
3158 pfn1 = pfn_from_ptrmemfunc (op1);
3159 delta0 = build_ptrmemfunc_access_expr (op0,
3161 delta1 = build_ptrmemfunc_access_expr (op1,
3163 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3164 e2 = cp_build_binary_op (EQ_EXPR,
3166 cp_convert (TREE_TYPE (pfn0),
3167 integer_zero_node));
3168 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3169 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3170 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3171 if (code == EQ_EXPR)
3173 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3177 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3178 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3180 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3181 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3189 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3190 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3192 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3193 result_type = composite_pointer_type (type0, type1, op0, op1,
3201 if (TREE_CODE (orig_op0) == STRING_CST
3202 || TREE_CODE (orig_op1) == STRING_CST)
3203 warning (OPT_Wstring_literal_comparison,
3204 "comparison with string literal");
3206 build_type = boolean_type_node;
3207 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3208 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3210 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3211 result_type = composite_pointer_type (type0, type1, op0, op1,
3213 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3214 && integer_zerop (op1))
3215 result_type = type0;
3216 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3217 && integer_zerop (op0))
3218 result_type = type1;
3219 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3221 result_type = type0;
3222 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3224 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3226 result_type = type1;
3227 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3231 case UNORDERED_EXPR:
3238 build_type = integer_type_node;
3239 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3241 error ("unordered comparison on non-floating point argument");
3242 return error_mark_node;
3251 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3252 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3253 || code1 == COMPLEX_TYPE)))
3254 arithmetic_types_p = 1;
3257 arithmetic_types_p = 0;
3258 /* Vector arithmetic is only allowed when both sides are vectors. */
3259 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3261 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3262 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3265 binary_op_error (code);
3266 return error_mark_node;
3268 arithmetic_types_p = 1;
3271 /* Determine the RESULT_TYPE, if it is not already known. */
3273 && arithmetic_types_p
3274 && (shorten || common || short_compare))
3275 result_type = common_type (type0, type1);
3279 error ("invalid operands of types %qT and %qT to binary %qO",
3280 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3281 return error_mark_node;
3284 /* If we're in a template, the only thing we need to know is the
3286 if (processing_template_decl)
3287 return build2 (resultcode,
3288 build_type ? build_type : result_type,
3291 if (arithmetic_types_p)
3293 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3295 /* For certain operations (which identify themselves by shorten != 0)
3296 if both args were extended from the same smaller type,
3297 do the arithmetic in that type and then extend.
3299 shorten !=0 and !=1 indicates a bitwise operation.
3300 For them, this optimization is safe only if
3301 both args are zero-extended or both are sign-extended.
3302 Otherwise, we might change the result.
3303 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3304 but calculated in (unsigned short) it would be (unsigned short)-1. */
3306 if (shorten && none_complex)
3308 int unsigned0, unsigned1;
3309 tree arg0 = get_narrower (op0, &unsigned0);
3310 tree arg1 = get_narrower (op1, &unsigned1);
3311 /* UNS is 1 if the operation to be done is an unsigned one. */
3312 int uns = TYPE_UNSIGNED (result_type);
3315 final_type = result_type;
3317 /* Handle the case that OP0 does not *contain* a conversion
3318 but it *requires* conversion to FINAL_TYPE. */
3320 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3321 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3322 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3323 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3325 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3327 /* For bitwise operations, signedness of nominal type
3328 does not matter. Consider only how operands were extended. */
3332 /* Note that in all three cases below we refrain from optimizing
3333 an unsigned operation on sign-extended args.
3334 That would not be valid. */
3336 /* Both args variable: if both extended in same way
3337 from same width, do it in that width.
3338 Do it unsigned if args were zero-extended. */
3339 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3340 < TYPE_PRECISION (result_type))
3341 && (TYPE_PRECISION (TREE_TYPE (arg1))
3342 == TYPE_PRECISION (TREE_TYPE (arg0)))
3343 && unsigned0 == unsigned1
3344 && (unsigned0 || !uns))
3345 result_type = c_common_signed_or_unsigned_type
3346 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3347 else if (TREE_CODE (arg0) == INTEGER_CST
3348 && (unsigned1 || !uns)
3349 && (TYPE_PRECISION (TREE_TYPE (arg1))
3350 < TYPE_PRECISION (result_type))
3351 && (type = c_common_signed_or_unsigned_type
3352 (unsigned1, TREE_TYPE (arg1)),
3353 int_fits_type_p (arg0, type)))
3355 else if (TREE_CODE (arg1) == INTEGER_CST
3356 && (unsigned0 || !uns)
3357 && (TYPE_PRECISION (TREE_TYPE (arg0))
3358 < TYPE_PRECISION (result_type))
3359 && (type = c_common_signed_or_unsigned_type
3360 (unsigned0, TREE_TYPE (arg0)),
3361 int_fits_type_p (arg1, type)))
3365 /* Shifts can be shortened if shifting right. */
3370 tree arg0 = get_narrower (op0, &unsigned_arg);
3372 final_type = result_type;
3374 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3375 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3377 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3378 /* We can shorten only if the shift count is less than the
3379 number of bits in the smaller type size. */
3380 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3381 /* If arg is sign-extended and then unsigned-shifted,
3382 we can simulate this with a signed shift in arg's type
3383 only if the extended result is at least twice as wide
3384 as the arg. Otherwise, the shift could use up all the
3385 ones made by sign-extension and bring in zeros.
3386 We can't optimize that case at all, but in most machines
3387 it never happens because available widths are 2**N. */
3388 && (!TYPE_UNSIGNED (final_type)
3390 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3391 <= TYPE_PRECISION (result_type))))
3393 /* Do an unsigned shift if the operand was zero-extended. */
3395 = c_common_signed_or_unsigned_type (unsigned_arg,
3397 /* Convert value-to-be-shifted to that type. */
3398 if (TREE_TYPE (op0) != result_type)
3399 op0 = cp_convert (result_type, op0);
3404 /* Comparison operations are shortened too but differently.
3405 They identify themselves by setting short_compare = 1. */
3409 /* Don't write &op0, etc., because that would prevent op0
3410 from being kept in a register.
3411 Instead, make copies of the our local variables and
3412 pass the copies by reference, then copy them back afterward. */
3413 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3414 enum tree_code xresultcode = resultcode;
3416 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3418 return cp_convert (boolean_type_node, val);
3419 op0 = xop0, op1 = xop1;
3421 resultcode = xresultcode;
3424 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3425 && warn_sign_compare
3426 /* Do not warn until the template is instantiated; we cannot
3427 bound the ranges of the arguments until that point. */
3428 && !processing_template_decl)
3430 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3431 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3433 int unsignedp0, unsignedp1;
3434 tree primop0 = get_narrower (op0, &unsignedp0);
3435 tree primop1 = get_narrower (op1, &unsignedp1);
3437 /* Check for comparison of different enum types. */
3438 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3439 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3440 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3441 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3443 warning (0, "comparison between types %q#T and %q#T",
3444 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3447 /* Give warnings for comparisons between signed and unsigned
3448 quantities that may fail. */
3449 /* Do the checking based on the original operand trees, so that
3450 casts will be considered, but default promotions won't be. */
3452 /* Do not warn if the comparison is being done in a signed type,
3453 since the signed type will only be chosen if it can represent
3454 all the values of the unsigned type. */
3455 if (!TYPE_UNSIGNED (result_type))
3457 /* Do not warn if both operands are unsigned. */
3458 else if (op0_signed == op1_signed)
3460 /* Do not warn if the signed quantity is an unsuffixed
3461 integer literal (or some static constant expression
3462 involving such literals or a conditional expression
3463 involving such literals) and it is non-negative. */
3464 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3465 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3467 /* Do not warn if the comparison is an equality operation,
3468 the unsigned quantity is an integral constant and it does
3469 not use the most significant bit of result_type. */
3470 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3471 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3472 && int_fits_type_p (orig_op1, c_common_signed_type
3474 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3475 && int_fits_type_p (orig_op0, c_common_signed_type
3479 warning (0, "comparison between signed and unsigned integer expressions");
3481 /* Warn if two unsigned values are being compared in a size
3482 larger than their original size, and one (and only one) is the
3483 result of a `~' operator. This comparison will always fail.
3485 Also warn if one operand is a constant, and the constant does not
3486 have all bits set that are set in the ~ operand when it is
3489 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3490 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3492 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3493 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3494 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3495 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3497 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3500 HOST_WIDE_INT constant, mask;
3504 if (host_integerp (primop0, 0))
3507 unsignedp = unsignedp1;
3508 constant = tree_low_cst (primop0, 0);
3513 unsignedp = unsignedp0;
3514 constant = tree_low_cst (primop1, 0);
3517 bits = TYPE_PRECISION (TREE_TYPE (primop));
3518 if (bits < TYPE_PRECISION (result_type)
3519 && bits < HOST_BITS_PER_LONG && unsignedp)
3521 mask = (~ (HOST_WIDE_INT) 0) << bits;
3522 if ((mask & constant) != mask)
3523 warning (0, "comparison of promoted ~unsigned with constant");
3526 else if (unsignedp0 && unsignedp1
3527 && (TYPE_PRECISION (TREE_TYPE (primop0))
3528 < TYPE_PRECISION (result_type))
3529 && (TYPE_PRECISION (TREE_TYPE (primop1))
3530 < TYPE_PRECISION (result_type)))
3531 warning (0, "comparison of promoted ~unsigned with unsigned");
3536 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3537 Then the expression will be built.
3538 It will be given type FINAL_TYPE if that is nonzero;
3539 otherwise, it will be given type RESULT_TYPE. */
3541 /* Issue warnings about peculiar, but valid, uses of NULL. */
3542 if (/* It's reasonable to use pointer values as operands of &&
3543 and ||, so NULL is no exception. */
3544 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3545 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3546 (orig_op0 == null_node
3547 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3548 /* Or vice versa. */
3549 || (orig_op1 == null_node
3550 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3551 /* Or, both are NULL and the operation was not a comparison. */
3552 || (orig_op0 == null_node && orig_op1 == null_node
3553 && code != EQ_EXPR && code != NE_EXPR)))
3554 /* Some sort of arithmetic operation involving NULL was
3555 performed. Note that pointer-difference and pointer-addition
3556 have already been handled above, and so we don't end up here in
3558 warning (0, "NULL used in arithmetic");
3562 if (TREE_TYPE (op0) != result_type)
3563 op0 = cp_convert (result_type, op0);
3564 if (TREE_TYPE (op1) != result_type)
3565 op1 = cp_convert (result_type, op1);
3567 if (op0 == error_mark_node || op1 == error_mark_node)
3568 return error_mark_node;
3571 if (build_type == NULL_TREE)
3572 build_type = result_type;
3574 result = build2 (resultcode, build_type, op0, op1);
3575 result = fold_if_not_in_template (result);
3576 if (final_type != 0)
3577 result = cp_convert (final_type, result);
3581 /* Return a tree for the sum or difference (RESULTCODE says which)
3582 of pointer PTROP and integer INTOP. */
3585 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3587 tree res_type = TREE_TYPE (ptrop);
3589 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3590 in certain circumstance (when it's valid to do so). So we need
3591 to make sure it's complete. We don't need to check here, if we
3592 can actually complete it at all, as those checks will be done in
3593 pointer_int_sum() anyway. */
3594 complete_type (TREE_TYPE (res_type));
3596 return pointer_int_sum (resultcode, ptrop,
3597 fold_if_not_in_template (intop));
3600 /* Return a tree for the difference of pointers OP0 and OP1.
3601 The resulting tree has type int. */
3604 pointer_diff (tree op0, tree op1, tree ptrtype)
3607 tree restype = ptrdiff_type_node;
3608 tree target_type = TREE_TYPE (ptrtype);
3610 if (!complete_type_or_else (target_type, NULL_TREE))
3611 return error_mark_node;
3613 if (pedantic || warn_pointer_arith)
3615 if (TREE_CODE (target_type) == VOID_TYPE)
3616 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3617 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3618 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3619 if (TREE_CODE (target_type) == METHOD_TYPE)
3620 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3623 /* First do the subtraction as integers;
3624 then drop through to build the divide operator. */
3626 op0 = cp_build_binary_op (MINUS_EXPR,
3627 cp_convert (restype, op0),
3628 cp_convert (restype, op1));
3630 /* This generates an error if op1 is a pointer to an incomplete type. */
3631 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3632 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3634 op1 = (TYPE_PTROB_P (ptrtype)
3635 ? size_in_bytes (target_type)
3636 : integer_one_node);
3638 /* Do the division. */
3640 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3641 return fold_if_not_in_template (result);
3644 /* Construct and perhaps optimize a tree representation
3645 for a unary operation. CODE, a tree_code, specifies the operation
3646 and XARG is the operand. */
3649 build_x_unary_op (enum tree_code code, tree xarg)
3651 tree orig_expr = xarg;
3655 if (processing_template_decl)
3657 if (type_dependent_expression_p (xarg))
3658 return build_min_nt (code, xarg, NULL_TREE);
3660 xarg = build_non_dependent_expr (xarg);
3665 /* [expr.unary.op] says:
3667 The address of an object of incomplete type can be taken.
3669 (And is just the ordinary address operator, not an overloaded
3670 "operator &".) However, if the type is a template
3671 specialization, we must complete the type at this point so that
3672 an overloaded "operator &" will be available if required. */
3673 if (code == ADDR_EXPR
3674 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3675 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3676 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3677 || (TREE_CODE (xarg) == OFFSET_REF)))
3678 /* Don't look for a function. */;
3680 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3681 /*overloaded_p=*/NULL);
3682 if (!exp && code == ADDR_EXPR)
3684 /* A pointer to member-function can be formed only by saying
3686 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3687 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3689 if (TREE_CODE (xarg) != OFFSET_REF
3690 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3692 error ("invalid use of %qE to form a pointer-to-member-function",
3694 if (TREE_CODE (xarg) != OFFSET_REF)
3695 inform (" a qualified-id is required");
3696 return error_mark_node;
3700 error ("parentheses around %qE cannot be used to form a"
3701 " pointer-to-member-function",
3703 PTRMEM_OK_P (xarg) = 1;
3707 if (TREE_CODE (xarg) == OFFSET_REF)
3709 ptrmem = PTRMEM_OK_P (xarg);
3711 if (!ptrmem && !flag_ms_extensions
3712 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3714 /* A single non-static member, make sure we don't allow a
3715 pointer-to-member. */
3716 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3717 TREE_OPERAND (xarg, 0),
3718 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3719 PTRMEM_OK_P (xarg) = ptrmem;
3722 else if (TREE_CODE (xarg) == TARGET_EXPR)
3723 warning (0, "taking address of temporary");
3724 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3727 if (processing_template_decl && exp != error_mark_node)
3728 exp = build_min_non_dep (code, exp, orig_expr,
3729 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3730 if (TREE_CODE (exp) == ADDR_EXPR)
3731 PTRMEM_OK_P (exp) = ptrmem;
3735 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3736 constants, where a null value is represented by an INTEGER_CST of
3740 cp_truthvalue_conversion (tree expr)
3742 tree type = TREE_TYPE (expr);
3743 if (TYPE_PTRMEM_P (type))
3744 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3746 return c_common_truthvalue_conversion (expr);
3749 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3752 condition_conversion (tree expr)
3755 if (processing_template_decl)
3757 t = perform_implicit_conversion (boolean_type_node, expr);
3758 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3762 /* Return an ADDR_EXPR giving the address of T. This function
3763 attempts no optimizations or simplifications; it is a low-level
3767 build_address (tree t)
3771 if (error_operand_p (t) || !cxx_mark_addressable (t))
3772 return error_mark_node;
3774 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3779 /* Return a NOP_EXPR converting EXPR to TYPE. */
3782 build_nop (tree type, tree expr)
3784 if (type == error_mark_node || error_operand_p (expr))
3786 return build1 (NOP_EXPR, type, expr);
3789 /* C++: Must handle pointers to members.
3791 Perhaps type instantiation should be extended to handle conversion
3792 from aggregates to types we don't yet know we want? (Or are those
3793 cases typically errors which should be reported?)
3795 NOCONVERT nonzero suppresses the default promotions
3796 (such as from short to int). */
3799 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3801 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3804 const char *errstring = NULL;
3806 const char *invalid_op_diag;
3808 if (arg == error_mark_node)
3809 return error_mark_node;
3811 if ((invalid_op_diag
3812 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
3817 error (invalid_op_diag);
3818 return error_mark_node;
3823 case UNARY_PLUS_EXPR:
3826 int flags = WANT_ARITH | WANT_ENUM;
3827 /* Unary plus (but not unary minus) is allowed on pointers. */
3828 if (code == UNARY_PLUS_EXPR)
3829 flags |= WANT_POINTER;
3830 arg = build_expr_type_conversion (flags, arg, true);
3832 errstring = (code == NEGATE_EXPR
3833 ? "wrong type argument to unary minus"
3834 : "wrong type argument to unary plus");
3837 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3838 arg = perform_integral_promotions (arg);
3840 /* Make sure the result is not an lvalue: a unary plus or minus
3841 expression is always a rvalue. */
3848 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3852 arg = default_conversion (arg);
3854 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3856 errstring = "wrong type argument to bit-complement";
3857 else if (!noconvert)
3858 arg = perform_integral_promotions (arg);
3862 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3863 errstring = "wrong type argument to abs";
3864 else if (!noconvert)
3865 arg = default_conversion (arg);
3869 /* Conjugating a real value is a no-op, but allow it anyway. */
3870 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3871 errstring = "wrong type argument to conjugation";
3872 else if (!noconvert)
3873 arg = default_conversion (arg);
3876 case TRUTH_NOT_EXPR:
3877 arg = perform_implicit_conversion (boolean_type_node, arg);
3878 val = invert_truthvalue (arg);
3879 if (arg != error_mark_node)
3881 errstring = "in argument to unary !";
3888 if (TREE_CODE (arg) == COMPLEX_CST)
3889 return TREE_REALPART (arg);
3890 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3892 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3893 return fold_if_not_in_template (arg);
3899 if (TREE_CODE (arg) == COMPLEX_CST)
3900 return TREE_IMAGPART (arg);
3901 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3903 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3904 return fold_if_not_in_template (arg);
3907 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3909 case PREINCREMENT_EXPR:
3910 case POSTINCREMENT_EXPR:
3911 case PREDECREMENT_EXPR:
3912 case POSTDECREMENT_EXPR:
3913 /* Handle complex lvalues (when permitted)
3914 by reduction to simpler cases. */
3916 val = unary_complex_lvalue (code, arg);
3920 /* Increment or decrement the real part of the value,
3921 and don't change the imaginary part. */
3922 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3926 arg = stabilize_reference (arg);
3927 real = build_unary_op (REALPART_EXPR, arg, 1);
3928 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3929 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3930 build_unary_op (code, real, 1), imag);
3933 /* Report invalid types. */
3935 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3938 if (code == PREINCREMENT_EXPR)
3939 errstring ="no pre-increment operator for type";
3940 else if (code == POSTINCREMENT_EXPR)
3941 errstring ="no post-increment operator for type";
3942 else if (code == PREDECREMENT_EXPR)
3943 errstring ="no pre-decrement operator for type";
3945 errstring ="no post-decrement operator for type";
3949 /* Report something read-only. */
3951 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3952 || TREE_READONLY (arg))
3953 readonly_error (arg, ((code == PREINCREMENT_EXPR
3954 || code == POSTINCREMENT_EXPR)
3955 ? "increment" : "decrement"),
3960 tree result_type = TREE_TYPE (arg);
3962 arg = get_unwidened (arg, 0);
3963 argtype = TREE_TYPE (arg);
3965 /* ARM $5.2.5 last annotation says this should be forbidden. */
3966 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3967 pedwarn ("ISO C++ forbids %sing an enum",
3968 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3969 ? "increment" : "decrement");
3971 /* Compute the increment. */
3973 if (TREE_CODE (argtype) == POINTER_TYPE)
3975 tree type = complete_type (TREE_TYPE (argtype));
3977 if (!COMPLETE_OR_VOID_TYPE_P (type))
3978 error ("cannot %s a pointer to incomplete type %qT",
3979 ((code == PREINCREMENT_EXPR
3980 || code == POSTINCREMENT_EXPR)
3981 ? "increment" : "decrement"), TREE_TYPE (argtype));
3982 else if ((pedantic || warn_pointer_arith)
3983 && !TYPE_PTROB_P (argtype))
3984 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3985 ((code == PREINCREMENT_EXPR
3986 || code == POSTINCREMENT_EXPR)
3987 ? "increment" : "decrement"), argtype);
3988 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3991 inc = integer_one_node;
3993 inc = cp_convert (argtype, inc);
3995 /* Handle incrementing a cast-expression. */
3997 switch (TREE_CODE (arg))
4002 case FIX_TRUNC_EXPR:
4003 case FIX_FLOOR_EXPR:
4004 case FIX_ROUND_EXPR:
4007 tree incremented, modify, value, compound;
4008 if (! lvalue_p (arg) && pedantic)
4009 pedwarn ("cast to non-reference type used as lvalue");
4010 arg = stabilize_reference (arg);
4011 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4014 value = save_expr (arg);
4015 incremented = build2 (((code == PREINCREMENT_EXPR
4016 || code == POSTINCREMENT_EXPR)
4017 ? PLUS_EXPR : MINUS_EXPR),
4018 argtype, value, inc);
4020 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4021 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4024 /* Eliminate warning about unused result of + or -. */
4025 TREE_NO_WARNING (compound) = 1;
4033 /* Complain about anything else that is not a true lvalue. */
4034 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4035 || code == POSTINCREMENT_EXPR)
4036 ? lv_increment : lv_decrement)))
4037 return error_mark_node;
4039 /* Forbid using -- on `bool'. */
4040 if (TREE_TYPE (arg) == boolean_type_node)
4042 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4044 error ("invalid use of %<--%> on bool variable %qD", arg);
4045 return error_mark_node;
4047 val = boolean_increment (code, arg);
4050 val = build2 (code, TREE_TYPE (arg), arg, inc);
4052 TREE_SIDE_EFFECTS (val) = 1;
4053 return cp_convert (result_type, val);
4057 /* Note that this operation never does default_conversion
4058 regardless of NOCONVERT. */
4060 argtype = lvalue_type (arg);
4062 if (TREE_CODE (arg) == OFFSET_REF)
4065 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4067 tree type = build_pointer_type (TREE_TYPE (argtype));
4068 arg = build1 (CONVERT_EXPR, type, arg);
4071 else if (pedantic && DECL_MAIN_P (arg))
4073 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4075 /* Let &* cancel out to simplify resulting code. */
4076 if (TREE_CODE (arg) == INDIRECT_REF)
4078 /* We don't need to have `current_class_ptr' wrapped in a
4079 NON_LVALUE_EXPR node. */
4080 if (arg == current_class_ref)
4081 return current_class_ptr;
4083 arg = TREE_OPERAND (arg, 0);
4084 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4086 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4087 arg = build1 (CONVERT_EXPR, type, arg);
4090 /* Don't let this be an lvalue. */
4095 /* Uninstantiated types are all functions. Taking the
4096 address of a function is a no-op, so just return the
4099 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4100 || !IDENTIFIER_OPNAME_P (arg));
4102 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4103 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4105 /* They're trying to take the address of a unique non-static
4106 member function. This is ill-formed (except in MS-land),
4107 but let's try to DTRT.
4108 Note: We only handle unique functions here because we don't
4109 want to complain if there's a static overload; non-unique
4110 cases will be handled by instantiate_type. But we need to
4111 handle this case here to allow casts on the resulting PMF.
4112 We could defer this in non-MS mode, but it's easier to give
4113 a useful error here. */
4115 /* Inside constant member functions, the `this' pointer
4116 contains an extra const qualifier. TYPE_MAIN_VARIANT
4117 is used here to remove this const from the diagnostics
4118 and the created OFFSET_REF. */
4119 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4120 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4122 if (! flag_ms_extensions)
4124 tree name = DECL_NAME (fn);
4125 if (current_class_type
4126 && TREE_OPERAND (arg, 0) == current_class_ref)
4127 /* An expression like &memfn. */
4128 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4129 " or parenthesized non-static member function to form"
4130 " a pointer to member function. Say %<&%T::%D%>",
4133 pedwarn ("ISO C++ forbids taking the address of a bound member"
4134 " function to form a pointer to member function."
4138 arg = build_offset_ref (base, fn, /*address_p=*/true);
4142 if (type_unknown_p (arg))
4143 return build1 (ADDR_EXPR, unknown_type_node, arg);
4145 /* Handle complex lvalues (when permitted)
4146 by reduction to simpler cases. */
4147 val = unary_complex_lvalue (code, arg);
4151 switch (TREE_CODE (arg))
4156 case FIX_TRUNC_EXPR:
4157 case FIX_FLOOR_EXPR:
4158 case FIX_ROUND_EXPR:
4160 if (! lvalue_p (arg) && pedantic)
4161 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4165 arg = OVL_CURRENT (arg);
4169 /* Turn a reference to a non-static data member into a
4170 pointer-to-member. */
4175 if (!PTRMEM_OK_P (arg))
4176 return build_unary_op (code, arg, 0);
4178 t = TREE_OPERAND (arg, 1);
4179 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4181 error ("cannot create pointer to reference member %qD", t);
4182 return error_mark_node;
4185 type = build_ptrmem_type (context_for_name_lookup (t),
4187 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4195 /* Anything not already handled and not a true memory reference
4197 if (TREE_CODE (argtype) != FUNCTION_TYPE
4198 && TREE_CODE (argtype) != METHOD_TYPE
4199 && TREE_CODE (arg) != OFFSET_REF
4200 /* Permit users to take the address of a compound-literal
4201 with sufficient simple elements. */
4202 && !(COMPOUND_LITERAL_P (arg) && TREE_STATIC (arg))
4203 && !lvalue_or_else (arg, lv_addressof))
4204 return error_mark_node;
4206 if (argtype != error_mark_node)
4207 argtype = build_pointer_type (argtype);
4209 /* In a template, we are processing a non-dependent expression
4210 so we can just form an ADDR_EXPR with the correct type. */
4211 if (processing_template_decl)
4213 val = build_address (arg);
4214 if (TREE_CODE (arg) == OFFSET_REF)
4215 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4219 /* If the user has taken the address of the compound literal,
4220 create a variable to contain the value of the literal and
4221 then return the address of that variable. */
4222 if (COMPOUND_LITERAL_P (arg))
4225 gcc_assert (TREE_STATIC (arg));
4226 var = create_temporary_var (TREE_TYPE (arg));
4227 TREE_STATIC (var) = 1;
4228 set_compound_literal_name (var);
4229 initialize_artificial_var (var, arg);
4230 arg = pushdecl (var);
4231 /* Since each compound literal is unique, pushdecl should
4232 never find a pre-existing variable with the same
4234 gcc_assert (arg == var);
4237 if (TREE_CODE (arg) != COMPONENT_REF)
4239 val = build_address (arg);
4240 if (TREE_CODE (arg) == OFFSET_REF)
4241 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4243 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4245 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4247 /* We can only get here with a single static member
4249 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4250 && DECL_STATIC_FUNCTION_P (fn));
4252 val = build_address (fn);
4253 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4254 /* Do not lose object's side effects. */
4255 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4256 TREE_OPERAND (arg, 0), val);
4258 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4260 error ("attempt to take address of bit-field structure member %qD",
4261 TREE_OPERAND (arg, 1));
4262 return error_mark_node;
4266 tree object = TREE_OPERAND (arg, 0);
4267 tree field = TREE_OPERAND (arg, 1);
4268 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4269 (TREE_TYPE (object), decl_type_context (field)));
4270 val = build_address (arg);
4273 if (TREE_CODE (argtype) == POINTER_TYPE
4274 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4276 build_ptrmemfunc_type (argtype);
4277 val = build_ptrmemfunc (argtype, val, 0,
4278 /*c_cast_p=*/false);
4290 argtype = TREE_TYPE (arg);
4291 return fold_if_not_in_template (build1 (code, argtype, arg));
4294 error ("%s", errstring);
4295 return error_mark_node;
4298 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4299 for certain kinds of expressions which are not really lvalues
4300 but which we can accept as lvalues.
4302 If ARG is not a kind of expression we can handle, return
4306 unary_complex_lvalue (enum tree_code code, tree arg)
4308 /* Inside a template, making these kinds of adjustments is
4309 pointless; we are only concerned with the type of the
4311 if (processing_template_decl)
4314 /* Handle (a, b) used as an "lvalue". */
4315 if (TREE_CODE (arg) == COMPOUND_EXPR)
4317 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4318 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4319 TREE_OPERAND (arg, 0), real_result);
4322 /* Handle (a ? b : c) used as an "lvalue". */
4323 if (TREE_CODE (arg) == COND_EXPR
4324 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4325 return rationalize_conditional_expr (code, arg);
4327 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4328 if (TREE_CODE (arg) == MODIFY_EXPR
4329 || TREE_CODE (arg) == PREINCREMENT_EXPR
4330 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4332 tree lvalue = TREE_OPERAND (arg, 0);
4333 if (TREE_SIDE_EFFECTS (lvalue))
4335 lvalue = stabilize_reference (lvalue);
4336 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4337 lvalue, TREE_OPERAND (arg, 1));
4339 return unary_complex_lvalue
4340 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4343 if (code != ADDR_EXPR)
4346 /* Handle (a = b) used as an "lvalue" for `&'. */
4347 if (TREE_CODE (arg) == MODIFY_EXPR
4348 || TREE_CODE (arg) == INIT_EXPR)
4350 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4351 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4353 TREE_NO_WARNING (arg) = 1;
4357 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4358 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4359 || TREE_CODE (arg) == OFFSET_REF)
4362 /* We permit compiler to make function calls returning
4363 objects of aggregate type look like lvalues. */
4367 if (TREE_CODE (targ) == SAVE_EXPR)
4368 targ = TREE_OPERAND (targ, 0);
4370 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4372 if (TREE_CODE (arg) == SAVE_EXPR)
4375 targ = build_cplus_new (TREE_TYPE (arg), arg);
4376 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4379 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4380 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4381 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4384 /* Don't let anything else be handled specially. */
4388 /* Mark EXP saying that we need to be able to take the
4389 address of it; it should not be allocated in a register.
4390 Value is true if successful.
4392 C++: we do not allow `current_class_ptr' to be addressable. */
4395 cxx_mark_addressable (tree exp)
4400 switch (TREE_CODE (x))
4407 x = TREE_OPERAND (x, 0);
4411 if (x == current_class_ptr)
4413 error ("cannot take the address of %<this%>, which is an rvalue expression");
4414 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4420 /* Caller should not be trying to mark initialized
4421 constant fields addressable. */
4422 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4423 || DECL_IN_AGGR_P (x) == 0
4425 || DECL_EXTERNAL (x));
4430 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4431 && !DECL_ARTIFICIAL (x))
4433 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4436 ("address of explicit register variable %qD requested", x);
4439 else if (extra_warnings)
4441 (0, "address requested for %qD, which is declared %<register%>", x);
4443 TREE_ADDRESSABLE (x) = 1;
4447 TREE_ADDRESSABLE (x) = 1;
4451 TREE_ADDRESSABLE (x) = 1;
4455 TREE_ADDRESSABLE (x) = 1;
4456 cxx_mark_addressable (TREE_OPERAND (x, 0));
4464 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4467 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4469 tree orig_ifexp = ifexp;
4470 tree orig_op1 = op1;
4471 tree orig_op2 = op2;
4474 if (processing_template_decl)
4476 /* The standard says that the expression is type-dependent if
4477 IFEXP is type-dependent, even though the eventual type of the
4478 expression doesn't dependent on IFEXP. */
4479 if (type_dependent_expression_p (ifexp)
4480 /* As a GNU extension, the middle operand may be omitted. */
4481 || (op1 && type_dependent_expression_p (op1))
4482 || type_dependent_expression_p (op2))
4483 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4484 ifexp = build_non_dependent_expr (ifexp);
4486 op1 = build_non_dependent_expr (op1);
4487 op2 = build_non_dependent_expr (op2);
4490 expr = build_conditional_expr (ifexp, op1, op2);
4491 if (processing_template_decl && expr != error_mark_node)
4492 return build_min_non_dep (COND_EXPR, expr,
4493 orig_ifexp, orig_op1, orig_op2);
4497 /* Given a list of expressions, return a compound expression
4498 that performs them all and returns the value of the last of them. */
4500 tree build_x_compound_expr_from_list (tree list, const char *msg)
4502 tree expr = TREE_VALUE (list);
4504 if (TREE_CHAIN (list))
4507 pedwarn ("%s expression list treated as compound expression", msg);
4509 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4510 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4516 /* Handle overloading of the ',' operator when needed. */
4519 build_x_compound_expr (tree op1, tree op2)
4522 tree orig_op1 = op1;
4523 tree orig_op2 = op2;
4525 if (processing_template_decl)
4527 if (type_dependent_expression_p (op1)
4528 || type_dependent_expression_p (op2))
4529 return build_min_nt (COMPOUND_EXPR, op1, op2);
4530 op1 = build_non_dependent_expr (op1);
4531 op2 = build_non_dependent_expr (op2);
4534 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4535 /*overloaded_p=*/NULL);
4537 result = build_compound_expr (op1, op2);
4539 if (processing_template_decl && result != error_mark_node)
4540 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4545 /* Build a compound expression. */
4548 build_compound_expr (tree lhs, tree rhs)
4550 lhs = convert_to_void (lhs, "left-hand operand of comma");
4552 if (lhs == error_mark_node || rhs == error_mark_node)
4553 return error_mark_node;
4555 if (TREE_CODE (rhs) == TARGET_EXPR)
4557 /* If the rhs is a TARGET_EXPR, then build the compound
4558 expression inside the target_expr's initializer. This
4559 helps the compiler to eliminate unnecessary temporaries. */
4560 tree init = TREE_OPERAND (rhs, 1);
4562 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4563 TREE_OPERAND (rhs, 1) = init;
4568 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4571 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4572 casts away constness. DIAG_FN gives the function to call if we
4573 need to issue a diagnostic; if it is NULL, no diagnostic will be
4574 issued. DESCRIPTION explains what operation is taking place. */
4577 check_for_casting_away_constness (tree src_type, tree dest_type,
4578 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4579 const char *description)
4581 if (diag_fn && casts_away_constness (src_type, dest_type))
4582 diag_fn ("%s from type %qT to type %qT casts away constness",
4583 description, src_type, dest_type);
4586 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4587 (another pointer-to-member type in the same hierarchy) and return
4588 the converted expression. If ALLOW_INVERSE_P is permitted, a
4589 pointer-to-derived may be converted to pointer-to-base; otherwise,
4590 only the other direction is permitted. If C_CAST_P is true, this
4591 conversion is taking place as part of a C-style cast. */
4594 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4597 if (TYPE_PTRMEM_P (type))
4601 if (TREE_CODE (expr) == PTRMEM_CST)
4602 expr = cplus_expand_constant (expr);
4603 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4604 TYPE_PTRMEM_CLASS_TYPE (type),
4607 if (!integer_zerop (delta))
4608 expr = cp_build_binary_op (PLUS_EXPR,
4609 build_nop (ptrdiff_type_node, expr),
4611 return build_nop (type, expr);
4614 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4615 allow_inverse_p, c_cast_p);
4618 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4619 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4620 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4623 ignore_overflows (tree expr, tree orig)
4625 if (TREE_CODE (expr) == INTEGER_CST
4626 && CONSTANT_CLASS_P (orig)
4627 && TREE_CODE (orig) != STRING_CST
4628 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4629 || TREE_CONSTANT_OVERFLOW (expr)
4630 != TREE_CONSTANT_OVERFLOW (orig)))
4632 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4633 /* Ensure constant sharing. */
4634 expr = build_int_cst_wide (TREE_TYPE (expr),
4635 TREE_INT_CST_LOW (expr),
4636 TREE_INT_CST_HIGH (expr));
4639 /* Avoid clobbering a shared constant. */
4640 expr = copy_node (expr);
4641 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4642 TREE_CONSTANT_OVERFLOW (expr)
4643 = TREE_CONSTANT_OVERFLOW (orig);
4649 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4650 this static_cast is being attempted as one of the possible casts
4651 allowed by a C-style cast. (In that case, accessibility of base
4652 classes is not considered, and it is OK to cast away
4653 constness.) Return the result of the cast. *VALID_P is set to
4654 indicate whether or not the cast was valid. */
4657 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4663 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4666 /* Assume the cast is valid. */
4669 intype = TREE_TYPE (expr);
4671 /* Determine what to do when casting away constness. */
4674 /* C-style casts are allowed to cast away constness. With
4675 WARN_CAST_QUAL, we still want to issue a warning. */
4676 diag_fn = warn_cast_qual ? warning0 : NULL;
4681 /* A static_cast may not cast away constness. */
4683 desc = "static_cast";
4686 /* [expr.static.cast]
4688 An lvalue of type "cv1 B", where B is a class type, can be cast
4689 to type "reference to cv2 D", where D is a class derived (clause
4690 _class.derived_) from B, if a valid standard conversion from
4691 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4692 same cv-qualification as, or greater cv-qualification than, cv1,
4693 and B is not a virtual base class of D. */
4694 /* We check this case before checking the validity of "TYPE t =
4695 EXPR;" below because for this case:
4698 struct D : public B { D(const B&); };
4700 void f() { static_cast<const D&>(b); }
4702 we want to avoid constructing a new D. The standard is not
4703 completely clear about this issue, but our interpretation is
4704 consistent with other compilers. */
4705 if (TREE_CODE (type) == REFERENCE_TYPE
4706 && CLASS_TYPE_P (TREE_TYPE (type))
4707 && CLASS_TYPE_P (intype)
4708 && real_lvalue_p (expr)
4709 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4710 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4711 build_pointer_type (TYPE_MAIN_VARIANT
4712 (TREE_TYPE (type))))
4714 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4718 /* There is a standard conversion from "D*" to "B*" even if "B"
4719 is ambiguous or inaccessible. If this is really a
4720 static_cast, then we check both for inaccessibility and
4721 ambiguity. However, if this is a static_cast being performed
4722 because the user wrote a C-style cast, then accessibility is
4724 base = lookup_base (TREE_TYPE (type), intype,
4725 c_cast_p ? ba_unique : ba_check,
4728 /* Convert from "B*" to "D*". This function will check that "B"
4729 is not a virtual base of "D". */
4730 expr = build_base_path (MINUS_EXPR, build_address (expr),
4731 base, /*nonnull=*/false);
4732 /* Convert the pointer to a reference -- but then remember that
4733 there are no expressions with reference type in C++. */
4734 return convert_from_reference (build_nop (type, expr));
4739 /* [expr.static.cast]
4741 An expression e can be explicitly converted to a type T using a
4742 static_cast of the form static_cast<T>(e) if the declaration T
4743 t(e);" is well-formed, for some invented temporary variable
4745 result = perform_direct_initialization_if_possible (type, expr,
4749 result = convert_from_reference (result);
4751 /* Ignore any integer overflow caused by the cast. */
4752 result = ignore_overflows (result, orig);
4754 /* [expr.static.cast]
4756 If T is a reference type, the result is an lvalue; otherwise,
4757 the result is an rvalue. */
4758 if (TREE_CODE (type) != REFERENCE_TYPE)
4759 result = rvalue (result);
4763 /* [expr.static.cast]
4765 Any expression can be explicitly converted to type cv void. */
4766 if (TREE_CODE (type) == VOID_TYPE)
4767 return convert_to_void (expr, /*implicit=*/NULL);
4769 /* [expr.static.cast]
4771 The inverse of any standard conversion sequence (clause _conv_),
4772 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4773 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4774 (_conv.bool_) conversions, can be performed explicitly using
4775 static_cast subject to the restriction that the explicit
4776 conversion does not cast away constness (_expr.const.cast_), and
4777 the following additional rules for specific cases: */
4778 /* For reference, the conversions not excluded are: integral
4779 promotions, floating point promotion, integral conversions,
4780 floating point conversions, floating-integral conversions,
4781 pointer conversions, and pointer to member conversions. */
4784 A value of integral _or enumeration_ type can be explicitly
4785 converted to an enumeration type. */
4786 /* The effect of all that is that any conversion between any two
4787 types which are integral, floating, or enumeration types can be
4789 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4790 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4792 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4794 /* Ignore any integer overflow caused by the cast. */
4795 expr = ignore_overflows (expr, orig);
4799 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4800 && CLASS_TYPE_P (TREE_TYPE (type))
4801 && CLASS_TYPE_P (TREE_TYPE (intype))
4802 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4803 (TREE_TYPE (intype))),
4804 build_pointer_type (TYPE_MAIN_VARIANT
4805 (TREE_TYPE (type)))))
4810 check_for_casting_away_constness (intype, type, diag_fn, desc);
4811 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4812 c_cast_p ? ba_unique : ba_check,
4814 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4817 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4818 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4825 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4826 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4828 if (TYPE_PTRMEM_P (type))
4830 t1 = (build_ptrmem_type
4832 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4833 t2 = (build_ptrmem_type
4835 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4842 if (can_convert (t1, t2))
4845 check_for_casting_away_constness (intype, type, diag_fn,
4847 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4852 /* [expr.static.cast]
4854 An rvalue of type "pointer to cv void" can be explicitly
4855 converted to a pointer to object type. A value of type pointer
4856 to object converted to "pointer to cv void" and back to the
4857 original pointer type will have its original value. */
4858 if (TREE_CODE (intype) == POINTER_TYPE
4859 && VOID_TYPE_P (TREE_TYPE (intype))
4860 && TYPE_PTROB_P (type))
4863 check_for_casting_away_constness (intype, type, diag_fn, desc);
4864 return build_nop (type, expr);
4868 return error_mark_node;
4871 /* Return an expression representing static_cast<TYPE>(EXPR). */
4874 build_static_cast (tree type, tree expr)
4879 if (type == error_mark_node || expr == error_mark_node)
4880 return error_mark_node;
4882 if (processing_template_decl)
4884 expr = build_min (STATIC_CAST_EXPR, type, expr);
4885 /* We don't know if it will or will not have side effects. */
4886 TREE_SIDE_EFFECTS (expr) = 1;
4887 return convert_from_reference (expr);
4890 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4891 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4892 if (TREE_CODE (type) != REFERENCE_TYPE
4893 && TREE_CODE (expr) == NOP_EXPR
4894 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4895 expr = TREE_OPERAND (expr, 0);
4897 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4901 error ("invalid static_cast from type %qT to type %qT",
4902 TREE_TYPE (expr), type);
4903 return error_mark_node;
4906 /* EXPR is an expression with member function or pointer-to-member
4907 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4908 not permitted by ISO C++, but we accept it in some modes. If we
4909 are not in one of those modes, issue a diagnostic. Return the
4910 converted expression. */
4913 convert_member_func_to_ptr (tree type, tree expr)
4918 intype = TREE_TYPE (expr);
4919 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4920 || TREE_CODE (intype) == METHOD_TYPE);
4922 if (pedantic || warn_pmf2ptr)
4923 pedwarn ("converting from %qT to %qT", intype, type);
4925 if (TREE_CODE (intype) == METHOD_TYPE)
4926 expr = build_addr_func (expr);
4927 else if (TREE_CODE (expr) == PTRMEM_CST)
4928 expr = build_address (PTRMEM_CST_MEMBER (expr));
4931 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4932 decl = build_address (decl);
4933 expr = get_member_function_from_ptrfunc (&decl, expr);
4936 return build_nop (type, expr);
4939 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4940 If C_CAST_P is true, this reinterpret cast is being done as part of
4941 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4942 indicate whether or not reinterpret_cast was valid. */
4945 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4950 /* Assume the cast is invalid. */
4954 if (type == error_mark_node || error_operand_p (expr))
4955 return error_mark_node;
4957 intype = TREE_TYPE (expr);
4959 /* [expr.reinterpret.cast]
4960 An lvalue expression of type T1 can be cast to the type
4961 "reference to T2" if an expression of type "pointer to T1" can be
4962 explicitly converted to the type "pointer to T2" using a
4963 reinterpret_cast. */
4964 if (TREE_CODE (type) == REFERENCE_TYPE)
4966 if (! real_lvalue_p (expr))
4968 error ("invalid cast of an rvalue expression of type "
4971 return error_mark_node;
4974 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4975 "B" are related class types; the reinterpret_cast does not
4976 adjust the pointer. */
4977 if (TYPE_PTR_P (intype)
4978 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4979 COMPARE_BASE | COMPARE_DERIVED)))
4980 warning (0, "casting %qT to %qT does not dereference pointer",
4983 expr = build_unary_op (ADDR_EXPR, expr, 0);
4984 if (expr != error_mark_node)
4985 expr = build_reinterpret_cast_1
4986 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4988 if (expr != error_mark_node)
4989 expr = build_indirect_ref (expr, 0);
4993 /* As a G++ extension, we consider conversions from member
4994 functions, and pointers to member functions to
4995 pointer-to-function and pointer-to-void types. If
4996 -Wno-pmf-conversions has not been specified,
4997 convert_member_func_to_ptr will issue an error message. */
4998 if ((TYPE_PTRMEMFUNC_P (intype)
4999 || TREE_CODE (intype) == METHOD_TYPE)
5000 && TYPE_PTR_P (type)
5001 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5002 || VOID_TYPE_P (TREE_TYPE (type))))
5003 return convert_member_func_to_ptr (type, expr);
5005 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5006 array-to-pointer, and function-to-pointer conversions are
5008 expr = decay_conversion (expr);
5010 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5011 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5012 if (TREE_CODE (expr) == NOP_EXPR
5013 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5014 expr = TREE_OPERAND (expr, 0);
5016 if (error_operand_p (expr))
5017 return error_mark_node;
5019 intype = TREE_TYPE (expr);
5021 /* [expr.reinterpret.cast]
5022 A pointer can be converted to any integral type large enough to
5024 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5026 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5027 pedwarn ("cast from %qT to %qT loses precision",
5030 /* [expr.reinterpret.cast]
5031 A value of integral or enumeration type can be explicitly
5032 converted to a pointer. */
5033 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5036 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5037 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5038 return fold_if_not_in_template (build_nop (type, expr));
5039 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5040 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5045 check_for_casting_away_constness (intype, type, error,
5046 "reinterpret_cast");
5047 /* Warn about possible alignment problems. */
5048 if (STRICT_ALIGNMENT && warn_cast_align
5049 && !VOID_TYPE_P (type)
5050 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5051 && COMPLETE_TYPE_P (TREE_TYPE (type))
5052 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5053 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5054 warning (0, "cast from %qT to %qT increases required alignment of "
5058 /* We need to strip nops here, because the frontend likes to
5059 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5061 strict_aliasing_warning (intype, type, sexpr);
5063 return fold_if_not_in_template (build_nop (type, expr));
5065 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5066 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5069 /* Only issue a warning, as we have always supported this
5070 where possible, and it is necessary in some cases. DR 195
5071 addresses this issue, but as of 2004/10/26 is still in
5073 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5074 return fold_if_not_in_template (build_nop (type, expr));
5076 else if (TREE_CODE (type) == VECTOR_TYPE)
5077 return fold_if_not_in_template (convert_to_vector (type, expr));
5078 else if (TREE_CODE (intype) == VECTOR_TYPE)
5079 return fold_if_not_in_template (convert_to_integer (type, expr));
5084 error ("invalid cast from type %qT to type %qT", intype, type);
5085 return error_mark_node;
5088 return cp_convert (type, expr);
5092 build_reinterpret_cast (tree type, tree expr)
5094 if (type == error_mark_node || expr == error_mark_node)
5095 return error_mark_node;
5097 if (processing_template_decl)
5099 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5101 if (!TREE_SIDE_EFFECTS (t)
5102 && type_dependent_expression_p (expr))
5103 /* There might turn out to be side effects inside expr. */
5104 TREE_SIDE_EFFECTS (t) = 1;
5105 return convert_from_reference (t);
5108 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5112 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5113 return an appropriate expression. Otherwise, return
5114 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5115 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5116 performing a C-style cast, its value upon return will indicate
5117 whether or not the conversion succeeded. */
5120 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5124 tree reference_type;
5126 /* Callers are responsible for handling error_mark_node as a
5127 destination type. */
5128 gcc_assert (dst_type != error_mark_node);
5129 /* In a template, callers should be building syntactic
5130 representations of casts, not using this machinery. */
5131 gcc_assert (!processing_template_decl);
5133 /* Assume the conversion is invalid. */
5137 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5140 error ("invalid use of const_cast with type %qT, "
5141 "which is not a pointer, "
5142 "reference, nor a pointer-to-data-member type", dst_type);
5143 return error_mark_node;
5146 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5149 error ("invalid use of const_cast with type %qT, which is a pointer "
5150 "or reference to a function type", dst_type);
5151 return error_mark_node;
5154 src_type = TREE_TYPE (expr);
5155 /* Expressions do not really have reference types. */
5156 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5157 src_type = TREE_TYPE (src_type);
5159 /* [expr.const.cast]
5161 An lvalue of type T1 can be explicitly converted to an lvalue of
5162 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5163 types) if a pointer to T1 can be explicitly converted to the type
5164 pointer to T2 using a const_cast. */
5165 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5167 reference_type = dst_type;
5168 if (! real_lvalue_p (expr))
5171 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5172 src_type, dst_type);
5173 return error_mark_node;
5175 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5176 src_type = build_pointer_type (src_type);
5180 reference_type = NULL_TREE;
5181 /* If the destination type is not a reference type, the
5182 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5183 conversions are performed. */
5184 src_type = type_decays_to (src_type);
5185 if (src_type == error_mark_node)
5186 return error_mark_node;
5189 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5190 && comp_ptr_ttypes_const (dst_type, src_type))
5195 /* This cast is actually a C-style cast. Issue a warning if
5196 the user is making a potentially unsafe cast. */
5198 check_for_casting_away_constness (src_type, dst_type,
5204 expr = build_unary_op (ADDR_EXPR, expr, 0);
5205 expr = build_nop (reference_type, expr);
5206 return convert_from_reference (expr);
5210 expr = decay_conversion (expr);
5211 /* build_c_cast puts on a NOP_EXPR to make the result not an
5212 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5213 non-lvalue context. */
5214 if (TREE_CODE (expr) == NOP_EXPR
5215 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5216 expr = TREE_OPERAND (expr, 0);
5217 return build_nop (dst_type, expr);
5222 error ("invalid const_cast from type %qT to type %qT",
5223 src_type, dst_type);
5224 return error_mark_node;
5228 build_const_cast (tree type, tree expr)
5230 if (type == error_mark_node || error_operand_p (expr))
5231 return error_mark_node;
5233 if (processing_template_decl)
5235 tree t = build_min (CONST_CAST_EXPR, type, expr);
5237 if (!TREE_SIDE_EFFECTS (t)
5238 && type_dependent_expression_p (expr))
5239 /* There might turn out to be side effects inside expr. */
5240 TREE_SIDE_EFFECTS (t) = 1;
5241 return convert_from_reference (t);
5244 return build_const_cast_1 (type, expr, /*complain=*/true,
5248 /* Build an expression representing an explicit C-style cast to type
5249 TYPE of expression EXPR. */
5252 build_c_cast (tree type, tree expr)
5258 if (type == error_mark_node || error_operand_p (expr))
5259 return error_mark_node;
5261 if (processing_template_decl)
5263 tree t = build_min (CAST_EXPR, type,
5264 tree_cons (NULL_TREE, value, NULL_TREE));
5265 /* We don't know if it will or will not have side effects. */
5266 TREE_SIDE_EFFECTS (t) = 1;
5267 return convert_from_reference (t);
5270 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5271 'Class') should always be retained, because this information aids
5272 in method lookup. */
5273 if (objc_is_object_ptr (type)
5274 && objc_is_object_ptr (TREE_TYPE (expr)))
5275 return build_nop (type, expr);
5277 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5278 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5279 if (TREE_CODE (type) != REFERENCE_TYPE
5280 && TREE_CODE (value) == NOP_EXPR
5281 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5282 value = TREE_OPERAND (value, 0);
5284 if (TREE_CODE (type) == ARRAY_TYPE)
5286 /* Allow casting from T1* to T2[] because Cfront allows it.
5287 NIHCL uses it. It is not valid ISO C++ however. */
5288 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5290 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5291 type = build_pointer_type (TREE_TYPE (type));
5295 error ("ISO C++ forbids casting to an array type %qT", type);
5296 return error_mark_node;
5300 if (TREE_CODE (type) == FUNCTION_TYPE
5301 || TREE_CODE (type) == METHOD_TYPE)
5303 error ("invalid cast to function type %qT", type);
5304 return error_mark_node;
5307 /* A C-style cast can be a const_cast. */
5308 result = build_const_cast_1 (type, value, /*complain=*/false,
5313 /* Or a static cast. */
5314 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5316 /* Or a reinterpret_cast. */
5318 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5320 /* The static_cast or reinterpret_cast may be followed by a
5323 /* A valid cast may result in errors if, for example, a
5324 conversion to am ambiguous base class is required. */
5325 && !error_operand_p (result))
5329 /* Non-class rvalues always have cv-unqualified type. */
5330 if (!CLASS_TYPE_P (type))
5331 type = TYPE_MAIN_VARIANT (type);
5332 result_type = TREE_TYPE (result);
5333 if (!CLASS_TYPE_P (result_type))
5334 result_type = TYPE_MAIN_VARIANT (result_type);
5335 /* If the type of RESULT does not match TYPE, perform a
5336 const_cast to make it match. If the static_cast or
5337 reinterpret_cast succeeded, we will differ by at most
5338 cv-qualification, so the follow-on const_cast is guaranteed
5340 if (!same_type_p (non_reference (type), non_reference (result_type)))
5342 result = build_const_cast_1 (type, result, false, &valid_p);
5343 gcc_assert (valid_p);
5348 return error_mark_node;
5351 /* Build an assignment expression of lvalue LHS from value RHS.
5352 MODIFYCODE is the code for a binary operator that we use
5353 to combine the old value of LHS with RHS to get the new value.
5354 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5356 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5359 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5363 tree lhstype = TREE_TYPE (lhs);
5364 tree olhstype = lhstype;
5365 tree olhs = NULL_TREE;
5366 bool plain_assign = (modifycode == NOP_EXPR);
5368 /* Avoid duplicate error messages from operands that had errors. */
5369 if (lhs == error_mark_node || rhs == error_mark_node)
5370 return error_mark_node;
5372 /* Handle control structure constructs used as "lvalues". */
5373 switch (TREE_CODE (lhs))
5375 /* Handle --foo = 5; as these are valid constructs in C++. */
5376 case PREDECREMENT_EXPR:
5377 case PREINCREMENT_EXPR:
5378 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5379 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5380 stabilize_reference (TREE_OPERAND (lhs, 0)),
5381 TREE_OPERAND (lhs, 1));
5382 return build2 (COMPOUND_EXPR, lhstype,
5384 build_modify_expr (TREE_OPERAND (lhs, 0),
5387 /* Handle (a, b) used as an "lvalue". */
5389 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5391 if (newrhs == error_mark_node)
5392 return error_mark_node;
5393 return build2 (COMPOUND_EXPR, lhstype,
5394 TREE_OPERAND (lhs, 0), newrhs);
5397 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5398 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5399 stabilize_reference (TREE_OPERAND (lhs, 0)),
5400 TREE_OPERAND (lhs, 1));
5401 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5402 if (newrhs == error_mark_node)
5403 return error_mark_node;
5404 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5408 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5409 when neither operand has side-effects. */
5410 if (!lvalue_or_else (lhs, lv_assign))
5411 return error_mark_node;
5413 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5414 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5416 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5417 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5419 TREE_OPERAND (lhs, 0),
5420 TREE_OPERAND (lhs, 1)),
5421 TREE_OPERAND (lhs, 0),
5422 TREE_OPERAND (lhs, 1));
5425 /* Handle (a ? b : c) used as an "lvalue". */
5428 /* Produce (a ? (b = rhs) : (c = rhs))
5429 except that the RHS goes through a save-expr
5430 so the code to compute it is only emitted once. */
5432 tree preeval = NULL_TREE;
5434 rhs = stabilize_expr (rhs, &preeval);
5436 /* Check this here to avoid odd errors when trying to convert
5437 a throw to the type of the COND_EXPR. */
5438 if (!lvalue_or_else (lhs, lv_assign))
5439 return error_mark_node;
5441 cond = build_conditional_expr
5442 (TREE_OPERAND (lhs, 0),
5443 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5444 TREE_OPERAND (lhs, 1)),
5446 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5447 TREE_OPERAND (lhs, 2)),
5450 if (cond == error_mark_node)
5452 /* Make sure the code to compute the rhs comes out
5453 before the split. */
5455 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5463 if (modifycode == INIT_EXPR)
5465 if (TREE_CODE (rhs) == CONSTRUCTOR)
5467 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5468 /* Call convert to generate an error; see PR 11063. */
5469 rhs = convert (lhstype, rhs);
5470 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5471 TREE_SIDE_EFFECTS (result) = 1;
5474 else if (! IS_AGGR_TYPE (lhstype))
5475 /* Do the default thing. */;
5478 result = build_special_member_call (lhs, complete_ctor_identifier,
5479 build_tree_list (NULL_TREE, rhs),
5480 lhstype, LOOKUP_NORMAL);
5481 if (result == NULL_TREE)
5482 return error_mark_node;
5488 lhs = require_complete_type (lhs);
5489 if (lhs == error_mark_node)
5490 return error_mark_node;
5492 if (modifycode == NOP_EXPR)
5494 /* `operator=' is not an inheritable operator. */
5495 if (! IS_AGGR_TYPE (lhstype))
5496 /* Do the default thing. */;
5499 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5500 lhs, rhs, make_node (NOP_EXPR),
5501 /*overloaded_p=*/NULL);
5502 if (result == NULL_TREE)
5503 return error_mark_node;
5510 /* A binary op has been requested. Combine the old LHS
5511 value with the RHS producing the value we should actually
5512 store into the LHS. */
5514 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5515 lhs = stabilize_reference (lhs);
5516 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5517 if (newrhs == error_mark_node)
5519 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5520 TREE_TYPE (lhs), TREE_TYPE (rhs));
5521 return error_mark_node;
5524 /* Now it looks like a plain assignment. */
5525 modifycode = NOP_EXPR;
5527 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5528 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5531 /* The left-hand side must be an lvalue. */
5532 if (!lvalue_or_else (lhs, lv_assign))
5533 return error_mark_node;
5535 /* Warn about modifying something that is `const'. Don't warn if
5536 this is initialization. */
5537 if (modifycode != INIT_EXPR
5538 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5539 /* Functions are not modifiable, even though they are
5541 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5542 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5543 /* If it's an aggregate and any field is const, then it is
5544 effectively const. */
5545 || (CLASS_TYPE_P (lhstype)
5546 && C_TYPE_FIELDS_READONLY (lhstype))))
5547 readonly_error (lhs, "assignment", 0);
5549 /* If storing into a structure or union member, it has probably been
5550 given type `int'. Compute the type that would go with the actual
5551 amount of storage the member occupies. */
5553 if (TREE_CODE (lhs) == COMPONENT_REF
5554 && (TREE_CODE (lhstype) == INTEGER_TYPE
5555 || TREE_CODE (lhstype) == REAL_TYPE
5556 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5558 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5560 /* If storing in a field that is in actuality a short or narrower
5561 than one, we must store in the field in its actual type. */
5563 if (lhstype != TREE_TYPE (lhs))
5565 /* Avoid warnings converting integral types back into enums for
5567 if (TREE_CODE (lhstype) == INTEGER_TYPE
5568 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5570 if (TREE_SIDE_EFFECTS (lhs))
5571 lhs = stabilize_reference (lhs);
5574 lhs = copy_node (lhs);
5575 TREE_TYPE (lhs) = lhstype;
5579 /* Convert new value to destination type. */
5581 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5585 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5586 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5588 error ("incompatible types in assignment of %qT to %qT",
5589 TREE_TYPE (rhs), lhstype);
5590 return error_mark_node;
5593 /* Allow array assignment in compiler-generated code. */
5594 if (! DECL_ARTIFICIAL (current_function_decl))
5595 pedwarn ("ISO C++ forbids assignment of arrays");
5597 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5598 ? 1 + (modifycode != INIT_EXPR): 0;
5599 return build_vec_init (lhs, NULL_TREE, newrhs,
5600 /*explicit_default_init_p=*/false,
5604 if (modifycode == INIT_EXPR)
5605 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5606 "initialization", NULL_TREE, 0);
5609 /* Avoid warnings on enum bit fields. */
5610 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5611 && TREE_CODE (lhstype) == INTEGER_TYPE)
5613 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5615 newrhs = convert_force (lhstype, newrhs, 0);
5618 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5620 if (TREE_CODE (newrhs) == CALL_EXPR
5621 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5622 newrhs = build_cplus_new (lhstype, newrhs);
5624 /* Can't initialize directly from a TARGET_EXPR, since that would
5625 cause the lhs to be constructed twice, and possibly result in
5626 accidental self-initialization. So we force the TARGET_EXPR to be
5627 expanded without a target. */
5628 if (TREE_CODE (newrhs) == TARGET_EXPR)
5629 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5630 TREE_OPERAND (newrhs, 0));
5633 if (newrhs == error_mark_node)
5634 return error_mark_node;
5636 if (c_dialect_objc () && flag_objc_gc)
5638 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5644 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5645 lhstype, lhs, newrhs);
5647 TREE_SIDE_EFFECTS (result) = 1;
5649 TREE_NO_WARNING (result) = 1;
5651 /* If we got the LHS in a different type for storing in,
5652 convert the result back to the nominal type of LHS
5653 so that the value we return always has the same type
5654 as the LHS argument. */
5656 if (olhstype == TREE_TYPE (result))
5660 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5661 TREE_NO_WARNING (result) = 1;
5664 return convert_for_assignment (olhstype, result, "assignment",
5669 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5671 if (processing_template_decl)
5672 return build_min_nt (MODOP_EXPR, lhs,
5673 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5675 if (modifycode != NOP_EXPR)
5677 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5678 make_node (modifycode),
5679 /*overloaded_p=*/NULL);
5682 TREE_NO_WARNING (rval) = 1;
5686 return build_modify_expr (lhs, modifycode, rhs);
5690 /* Get difference in deltas for different pointer to member function
5691 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5692 the conversion is invalid, the constant is zero. If
5693 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5694 If C_CAST_P is true this conversion is taking place as part of a
5697 Note that the naming of FROM and TO is kind of backwards; the return
5698 value is what we add to a TO in order to get a FROM. They are named
5699 this way because we call this function to find out how to convert from
5700 a pointer to member of FROM to a pointer to member of TO. */
5703 get_delta_difference (tree from, tree to,
5704 bool allow_inverse_p,
5711 /* Assume no conversion is required. */
5712 result = integer_zero_node;
5713 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5714 if (kind == bk_inaccessible || kind == bk_ambig)
5715 error (" in pointer to member function conversion");
5718 if (kind != bk_via_virtual)
5719 result = BINFO_OFFSET (binfo);
5722 tree virt_binfo = binfo_from_vbase (binfo);
5724 /* This is a reinterpret cast, we choose to do nothing. */
5725 if (allow_inverse_p)
5726 warning (0, "pointer to member cast via virtual base %qT",
5727 BINFO_TYPE (virt_binfo));
5729 error ("pointer to member conversion via virtual base %qT",
5730 BINFO_TYPE (virt_binfo));
5733 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5734 /* Pointer to member of incomplete class is permitted*/;
5735 else if (!allow_inverse_p)
5737 error_not_base_type (from, to);
5738 error (" in pointer to member conversion");
5742 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5745 if (kind != bk_via_virtual)
5746 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5749 /* This is a reinterpret cast, we choose to do nothing. */
5750 tree virt_binfo = binfo_from_vbase (binfo);
5752 warning (0, "pointer to member cast via virtual base %qT",
5753 BINFO_TYPE (virt_binfo));
5758 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5762 /* Return a constructor for the pointer-to-member-function TYPE using
5763 the other components as specified. */
5766 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5771 VEC(constructor_elt, gc) *v;
5773 /* Pull the FIELD_DECLs out of the type. */
5774 pfn_field = TYPE_FIELDS (type);
5775 delta_field = TREE_CHAIN (pfn_field);
5777 /* Make sure DELTA has the type we want. */
5778 delta = convert_and_check (delta_type_node, delta);
5780 /* Finish creating the initializer. */
5781 v = VEC_alloc(constructor_elt, gc, 2);
5782 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
5783 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
5784 u = build_constructor (type, v);
5785 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5786 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5787 TREE_STATIC (u) = (TREE_CONSTANT (u)
5788 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5790 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5795 /* Build a constructor for a pointer to member function. It can be
5796 used to initialize global variables, local variable, or used
5797 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5800 If FORCE is nonzero, then force this conversion, even if
5801 we would rather not do it. Usually set when using an explicit
5802 cast. A C-style cast is being processed iff C_CAST_P is true.
5804 Return error_mark_node, if something goes wrong. */
5807 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5813 if (error_operand_p (pfn))
5814 return error_mark_node;
5816 pfn_type = TREE_TYPE (pfn);
5817 to_type = build_ptrmemfunc_type (type);
5819 /* Handle multiple conversions of pointer to member functions. */
5820 if (TYPE_PTRMEMFUNC_P (pfn_type))
5822 tree delta = NULL_TREE;
5823 tree npfn = NULL_TREE;
5827 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
5828 error ("invalid conversion to type %qT from type %qT",
5831 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5832 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5836 /* We don't have to do any conversion to convert a
5837 pointer-to-member to its own type. But, we don't want to
5838 just return a PTRMEM_CST if there's an explicit cast; that
5839 cast should make the expression an invalid template argument. */
5840 if (TREE_CODE (pfn) != PTRMEM_CST)
5842 if (same_type_p (to_type, pfn_type))
5844 else if (integer_zerop (n))
5845 return build_reinterpret_cast (to_type, pfn);
5848 if (TREE_SIDE_EFFECTS (pfn))
5849 pfn = save_expr (pfn);
5851 /* Obtain the function pointer and the current DELTA. */
5852 if (TREE_CODE (pfn) == PTRMEM_CST)
5853 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5856 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5857 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5860 /* Just adjust the DELTA field. */
5861 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5862 (TREE_TYPE (delta), ptrdiff_type_node));
5863 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5864 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5865 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5866 return build_ptrmemfunc1 (to_type, delta, npfn);
5869 /* Handle null pointer to member function conversions. */
5870 if (integer_zerop (pfn))
5872 pfn = build_c_cast (type, integer_zero_node);
5873 return build_ptrmemfunc1 (to_type,
5878 if (type_unknown_p (pfn))
5879 return instantiate_type (type, pfn, tf_error | tf_warning);
5881 fn = TREE_OPERAND (pfn, 0);
5882 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
5883 /* In a template, we will have preserved the
5885 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
5886 return make_ptrmem_cst (to_type, fn);
5889 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5892 ??? There is no consistency as to the types returned for the above
5893 values. Some code acts as if it were a sizetype and some as if it were
5894 integer_type_node. */
5897 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5899 tree type = TREE_TYPE (cst);
5900 tree fn = PTRMEM_CST_MEMBER (cst);
5901 tree ptr_class, fn_class;
5903 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5905 /* The class that the function belongs to. */
5906 fn_class = DECL_CONTEXT (fn);
5908 /* The class that we're creating a pointer to member of. */
5909 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5911 /* First, calculate the adjustment to the function's class. */
5912 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5915 if (!DECL_VIRTUAL_P (fn))
5916 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5919 /* If we're dealing with a virtual function, we have to adjust 'this'
5920 again, to point to the base which provides the vtable entry for
5921 fn; the call will do the opposite adjustment. */
5922 tree orig_class = DECL_CONTEXT (fn);
5923 tree binfo = binfo_or_else (orig_class, fn_class);
5924 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5925 *delta, BINFO_OFFSET (binfo));
5926 *delta = fold_if_not_in_template (*delta);
5928 /* We set PFN to the vtable offset at which the function can be
5929 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5930 case delta is shifted left, and then incremented). */
5931 *pfn = DECL_VINDEX (fn);
5932 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5933 TYPE_SIZE_UNIT (vtable_entry_type));
5934 *pfn = fold_if_not_in_template (*pfn);
5936 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5938 case ptrmemfunc_vbit_in_pfn:
5939 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5941 *pfn = fold_if_not_in_template (*pfn);
5944 case ptrmemfunc_vbit_in_delta:
5945 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5946 *delta, integer_one_node);
5947 *delta = fold_if_not_in_template (*delta);
5948 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5949 *delta, integer_one_node);
5950 *delta = fold_if_not_in_template (*delta);
5957 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5958 *pfn = fold_if_not_in_template (*pfn);
5962 /* Return an expression for PFN from the pointer-to-member function
5966 pfn_from_ptrmemfunc (tree t)
5968 if (TREE_CODE (t) == PTRMEM_CST)
5973 expand_ptrmemfunc_cst (t, &delta, &pfn);
5978 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5981 /* Convert value RHS to type TYPE as preparation for an assignment to
5982 an lvalue of type TYPE. ERRTYPE is a string to use in error
5983 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5984 are doing the conversion in order to pass the PARMNUMth argument of
5988 convert_for_assignment (tree type, tree rhs,
5989 const char *errtype, tree fndecl, int parmnum)
5992 enum tree_code coder;
5994 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5995 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5996 rhs = TREE_OPERAND (rhs, 0);
5998 rhstype = TREE_TYPE (rhs);
5999 coder = TREE_CODE (rhstype);
6001 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6002 && vector_types_convertible_p (type, rhstype))
6003 return convert (type, rhs);
6005 if (rhs == error_mark_node || rhstype == error_mark_node)
6006 return error_mark_node;
6007 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6008 return error_mark_node;
6010 /* The RHS of an assignment cannot have void type. */
6011 if (coder == VOID_TYPE)
6013 error ("void value not ignored as it ought to be");
6014 return error_mark_node;
6017 /* Simplify the RHS if possible. */
6018 if (TREE_CODE (rhs) == CONST_DECL)
6019 rhs = DECL_INITIAL (rhs);
6021 if (c_dialect_objc ())
6024 tree rname = fndecl;
6026 if (!strcmp (errtype, "assignment"))
6028 else if (!strcmp (errtype, "initialization"))
6032 tree selector = objc_message_selector ();
6036 if (selector && parmno > 1)
6043 if (objc_compare_types (type, rhstype, parmno, rname))
6044 return convert (type, rhs);
6049 The expression is implicitly converted (clause _conv_) to the
6050 cv-unqualified type of the left operand.
6052 We allow bad conversions here because by the time we get to this point
6053 we are committed to doing the conversion. If we end up doing a bad
6054 conversion, convert_like will complain. */
6055 if (!can_convert_arg_bad (type, rhstype, rhs))
6057 /* When -Wno-pmf-conversions is use, we just silently allow
6058 conversions from pointers-to-members to plain pointers. If
6059 the conversion doesn't work, cp_convert will complain. */
6061 && TYPE_PTR_P (type)
6062 && TYPE_PTRMEMFUNC_P (rhstype))
6063 rhs = cp_convert (strip_top_quals (type), rhs);
6066 /* If the right-hand side has unknown type, then it is an
6067 overloaded function. Call instantiate_type to get error
6069 if (rhstype == unknown_type_node)
6070 instantiate_type (type, rhs, tf_error | tf_warning);
6072 error ("cannot convert %qT to %qT for argument %qP to %qD",
6073 rhstype, type, parmnum, fndecl);
6075 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6076 return error_mark_node;
6079 if (warn_missing_format_attribute)
6081 const enum tree_code codel = TREE_CODE (type);
6082 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6084 && check_missing_format_attribute (type, rhstype))
6085 warning (OPT_Wmissing_format_attribute,
6086 "%s might be a candidate for a format attribute",
6090 return perform_implicit_conversion (strip_top_quals (type), rhs);
6093 /* Convert RHS to be of type TYPE.
6094 If EXP is nonzero, it is the target of the initialization.
6095 ERRTYPE is a string to use in error messages.
6097 Two major differences between the behavior of
6098 `convert_for_assignment' and `convert_for_initialization'
6099 are that references are bashed in the former, while
6100 copied in the latter, and aggregates are assigned in
6101 the former (operator=) while initialized in the
6104 If using constructor make sure no conversion operator exists, if one does
6105 exist, an ambiguity exists.
6107 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6110 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6111 const char *errtype, tree fndecl, int parmnum)
6113 enum tree_code codel = TREE_CODE (type);
6115 enum tree_code coder;
6117 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6118 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6119 if (TREE_CODE (rhs) == NOP_EXPR
6120 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6121 && codel != REFERENCE_TYPE)
6122 rhs = TREE_OPERAND (rhs, 0);
6124 if (rhs == error_mark_node
6125 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6126 return error_mark_node;
6128 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6129 && TREE_CODE (type) != ARRAY_TYPE
6130 && (TREE_CODE (type) != REFERENCE_TYPE
6131 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6132 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6133 && (TREE_CODE (type) != REFERENCE_TYPE
6134 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6135 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6136 rhs = decay_conversion (rhs);
6138 rhstype = TREE_TYPE (rhs);
6139 coder = TREE_CODE (rhstype);
6141 if (coder == ERROR_MARK)
6142 return error_mark_node;
6144 /* We accept references to incomplete types, so we can
6145 return here before checking if RHS is of complete type. */
6147 if (codel == REFERENCE_TYPE)
6149 /* This should eventually happen in convert_arguments. */
6150 int savew = 0, savee = 0;
6153 savew = warningcount, savee = errorcount;
6154 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6158 if (warningcount > savew)
6159 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6160 else if (errorcount > savee)
6161 error ("in passing argument %P of %q+D", parmnum, fndecl);
6167 exp = require_complete_type (exp);
6168 if (exp == error_mark_node)
6169 return error_mark_node;
6171 rhstype = non_reference (rhstype);
6173 type = complete_type (type);
6175 if (IS_AGGR_TYPE (type))
6176 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6178 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6181 /* If RETVAL is the address of, or a reference to, a local variable or
6182 temporary give an appropriate warning. */
6185 maybe_warn_about_returning_address_of_local (tree retval)
6187 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6188 tree whats_returned = retval;
6192 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6193 whats_returned = TREE_OPERAND (whats_returned, 1);
6194 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6195 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6196 || TREE_CODE (whats_returned) == NOP_EXPR)
6197 whats_returned = TREE_OPERAND (whats_returned, 0);
6202 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6204 whats_returned = TREE_OPERAND (whats_returned, 0);
6206 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6208 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6209 || TREE_CODE (whats_returned) == TARGET_EXPR)
6211 warning (0, "returning reference to temporary");
6214 if (TREE_CODE (whats_returned) == VAR_DECL
6215 && DECL_NAME (whats_returned)
6216 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6218 warning (0, "reference to non-lvalue returned");
6223 if (DECL_P (whats_returned)
6224 && DECL_NAME (whats_returned)
6225 && DECL_FUNCTION_SCOPE_P (whats_returned)
6226 && !(TREE_STATIC (whats_returned)
6227 || TREE_PUBLIC (whats_returned)))
6229 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6230 warning (0, "reference to local variable %q+D returned",
6233 warning (0, "address of local variable %q+D returned",
6239 /* Check that returning RETVAL from the current function is valid.
6240 Return an expression explicitly showing all conversions required to
6241 change RETVAL into the function return type, and to assign it to
6242 the DECL_RESULT for the function. Set *NO_WARNING to true if
6243 code reaches end of non-void function warning shouldn't be issued
6244 on this RETURN_EXPR. */
6247 check_return_expr (tree retval, bool *no_warning)
6250 /* The type actually returned by the function, after any
6253 int fn_returns_value_p;
6255 *no_warning = false;
6257 /* A `volatile' function is one that isn't supposed to return, ever.
6258 (This is a G++ extension, used to get better code for functions
6259 that call the `volatile' function.) */
6260 if (TREE_THIS_VOLATILE (current_function_decl))
6261 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6263 /* Check for various simple errors. */
6264 if (DECL_DESTRUCTOR_P (current_function_decl))
6267 error ("returning a value from a destructor");
6270 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6272 if (in_function_try_handler)
6273 /* If a return statement appears in a handler of the
6274 function-try-block of a constructor, the program is ill-formed. */
6275 error ("cannot return from a handler of a function-try-block of a constructor");
6277 /* You can't return a value from a constructor. */
6278 error ("returning a value from a constructor");
6282 if (processing_template_decl)
6284 current_function_returns_value = 1;
6288 /* When no explicit return-value is given in a function with a named
6289 return value, the named return value is used. */
6290 result = DECL_RESULT (current_function_decl);
6291 valtype = TREE_TYPE (result);
6292 gcc_assert (valtype != NULL_TREE);
6293 fn_returns_value_p = !VOID_TYPE_P (valtype);
6294 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6297 /* Check for a return statement with no return value in a function
6298 that's supposed to return a value. */
6299 if (!retval && fn_returns_value_p)
6301 pedwarn ("return-statement with no value, in function returning %qT",
6303 /* Clear this, so finish_function won't say that we reach the
6304 end of a non-void function (which we don't, we gave a
6306 current_function_returns_null = 0;
6307 /* And signal caller that TREE_NO_WARNING should be set on the
6308 RETURN_EXPR to avoid control reaches end of non-void function
6309 warnings in tree-cfg.c. */
6312 /* Check for a return statement with a value in a function that
6313 isn't supposed to return a value. */
6314 else if (retval && !fn_returns_value_p)
6316 if (VOID_TYPE_P (TREE_TYPE (retval)))
6317 /* You can return a `void' value from a function of `void'
6318 type. In that case, we have to evaluate the expression for
6319 its side-effects. */
6320 finish_expr_stmt (retval);
6322 pedwarn ("return-statement with a value, in function "
6323 "returning 'void'");
6325 current_function_returns_null = 1;
6327 /* There's really no value to return, after all. */
6331 /* Remember that this function can sometimes return without a
6333 current_function_returns_null = 1;
6335 /* Remember that this function did return a value. */
6336 current_function_returns_value = 1;
6338 /* Check for erroneous operands -- but after giving ourselves a
6339 chance to provide an error about returning a value from a void
6341 if (error_operand_p (retval))
6343 current_function_return_value = error_mark_node;
6344 return error_mark_node;
6347 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6348 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6349 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6350 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6352 && null_ptr_cst_p (retval))
6353 warning (0, "%<operator new%> must not return NULL unless it is "
6354 "declared %<throw()%> (or -fcheck-new is in effect)");
6356 /* Effective C++ rule 15. See also start_function. */
6358 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6362 /* The function return type must be a reference to the current
6364 if (TREE_CODE (valtype) == REFERENCE_TYPE
6365 && same_type_ignoring_top_level_qualifiers_p
6366 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6368 /* Returning '*this' is obviously OK. */
6369 if (retval == current_class_ref)
6371 /* If we are calling a function whose return type is the same of
6372 the current class reference, it is ok. */
6373 else if (TREE_CODE (retval) == INDIRECT_REF
6374 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6379 warning (0, "%<operator=%> should return a reference to %<*this%>");
6382 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6384 [...] For a function with a class return type, if the expression
6385 in the return statement is the name of a local object, and the cv-
6386 unqualified type of the local object is the same as the function
6387 return type, an implementation is permitted to omit creating the tem-
6388 porary object to hold the function return value [...]
6390 So, if this is a value-returning function that always returns the same
6391 local variable, remember it.
6393 It might be nice to be more flexible, and choose the first suitable
6394 variable even if the function sometimes returns something else, but
6395 then we run the risk of clobbering the variable we chose if the other
6396 returned expression uses the chosen variable somehow. And people expect
6397 this restriction, anyway. (jason 2000-11-19)
6399 See finish_function and finalize_nrv for the rest of this optimization. */
6401 if (fn_returns_value_p && flag_elide_constructors)
6403 if (retval != NULL_TREE
6404 && (current_function_return_value == NULL_TREE
6405 || current_function_return_value == retval)
6406 && TREE_CODE (retval) == VAR_DECL
6407 && DECL_CONTEXT (retval) == current_function_decl
6408 && ! TREE_STATIC (retval)
6409 && (DECL_ALIGN (retval)
6410 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6411 && same_type_p ((TYPE_MAIN_VARIANT
6412 (TREE_TYPE (retval))),
6414 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6415 current_function_return_value = retval;
6417 current_function_return_value = error_mark_node;
6420 /* We don't need to do any conversions when there's nothing being
6425 /* Do any required conversions. */
6426 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6427 /* No conversions are required. */
6431 /* The type the function is declared to return. */
6432 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6434 /* The functype's return type will have been set to void, if it
6435 was an incomplete type. Just treat this as 'return;' */
6436 if (VOID_TYPE_P (functype))
6437 return error_mark_node;
6439 /* First convert the value to the function's return type, then
6440 to the type of return value's location to handle the
6441 case that functype is smaller than the valtype. */
6442 retval = convert_for_initialization
6443 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6444 "return", NULL_TREE, 0);
6445 retval = convert (valtype, retval);
6447 /* If the conversion failed, treat this just like `return;'. */
6448 if (retval == error_mark_node)
6450 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6451 else if (! current_function_returns_struct
6452 && TREE_CODE (retval) == TARGET_EXPR
6453 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6454 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6455 TREE_OPERAND (retval, 0));
6457 maybe_warn_about_returning_address_of_local (retval);
6460 /* Actually copy the value returned into the appropriate location. */
6461 if (retval && retval != result)
6462 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6468 /* Returns nonzero if the pointer-type FROM can be converted to the
6469 pointer-type TO via a qualification conversion. If CONSTP is -1,
6470 then we return nonzero if the pointers are similar, and the
6471 cv-qualification signature of FROM is a proper subset of that of TO.
6473 If CONSTP is positive, then all outer pointers have been
6477 comp_ptr_ttypes_real (tree to, tree from, int constp)
6479 bool to_more_cv_qualified = false;
6481 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6483 if (TREE_CODE (to) != TREE_CODE (from))
6486 if (TREE_CODE (from) == OFFSET_TYPE
6487 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6488 TYPE_OFFSET_BASETYPE (to)))
6491 /* Const and volatile mean something different for function types,
6492 so the usual checks are not appropriate. */
6493 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6495 /* In Objective-C++, some types may have been 'volatilized' by
6496 the compiler for EH; when comparing them here, the volatile
6497 qualification must be ignored. */
6498 bool objc_quals_match = objc_type_quals_match (to, from);
6500 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6503 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6507 to_more_cv_qualified = true;
6511 constp &= TYPE_READONLY (to);
6514 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6515 return ((constp >= 0 || to_more_cv_qualified)
6516 && same_type_ignoring_top_level_qualifiers_p (to, from));
6520 /* When comparing, say, char ** to char const **, this function takes
6521 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6522 types to this function. */
6525 comp_ptr_ttypes (tree to, tree from)
6527 return comp_ptr_ttypes_real (to, from, 1);
6530 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6531 type or inheritance-related types, regardless of cv-quals. */
6534 ptr_reasonably_similar (tree to, tree from)
6536 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6538 /* Any target type is similar enough to void. */
6539 if (TREE_CODE (to) == VOID_TYPE
6540 || TREE_CODE (from) == VOID_TYPE)
6543 if (TREE_CODE (to) != TREE_CODE (from))
6546 if (TREE_CODE (from) == OFFSET_TYPE
6547 && comptypes (TYPE_OFFSET_BASETYPE (to),
6548 TYPE_OFFSET_BASETYPE (from),
6549 COMPARE_BASE | COMPARE_DERIVED))
6552 if (TREE_CODE (to) == VECTOR_TYPE
6553 && vector_types_convertible_p (to, from))
6556 if (TREE_CODE (to) == INTEGER_TYPE
6557 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6560 if (TREE_CODE (to) == FUNCTION_TYPE)
6563 if (TREE_CODE (to) != POINTER_TYPE)
6565 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6566 COMPARE_BASE | COMPARE_DERIVED);
6570 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6571 pointer-to-member types) are the same, ignoring cv-qualification at
6575 comp_ptr_ttypes_const (tree to, tree from)
6577 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6579 if (TREE_CODE (to) != TREE_CODE (from))
6582 if (TREE_CODE (from) == OFFSET_TYPE
6583 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6584 TYPE_OFFSET_BASETYPE (to)))
6587 if (TREE_CODE (to) != POINTER_TYPE)
6588 return same_type_ignoring_top_level_qualifiers_p (to, from);
6592 /* Returns the type qualifiers for this type, including the qualifiers on the
6593 elements for an array type. */
6596 cp_type_quals (tree type)
6598 type = strip_array_types (type);
6599 if (type == error_mark_node)
6600 return TYPE_UNQUALIFIED;
6601 return TYPE_QUALS (type);
6604 /* Returns nonzero if the TYPE contains a mutable member. */
6607 cp_has_mutable_p (tree type)
6609 type = strip_array_types (type);
6611 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6614 /* Apply the TYPE_QUALS to the new DECL. */
6616 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6618 tree type = TREE_TYPE (decl);
6620 if (type == error_mark_node)
6623 if (TREE_CODE (type) == FUNCTION_TYPE
6624 && type_quals != TYPE_UNQUALIFIED)
6626 /* This was an error in C++98 (cv-qualifiers cannot be added to
6627 a function type), but DR 295 makes the code well-formed by
6628 dropping the extra qualifiers. */
6631 tree bad_type = build_qualified_type (type, type_quals);
6632 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6636 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6640 /* Avoid setting TREE_READONLY incorrectly. */
6641 if (/* If the object has a constructor, the constructor may modify
6643 TYPE_NEEDS_CONSTRUCTING (type)
6644 /* If the type isn't complete, we don't know yet if it will need
6646 || !COMPLETE_TYPE_P (type)
6647 /* If the type has a mutable component, that component might be
6649 || TYPE_HAS_MUTABLE_P (type))
6650 type_quals &= ~TYPE_QUAL_CONST;
6652 c_apply_type_quals_to_decl (type_quals, decl);
6655 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6656 exemplar types such that casting T1 to T2 is casting away constness
6657 if and only if there is no implicit conversion from T1 to T2. */
6660 casts_away_constness_r (tree *t1, tree *t2)
6665 /* [expr.const.cast]
6667 For multi-level pointer to members and multi-level mixed pointers
6668 and pointers to members (conv.qual), the "member" aspect of a
6669 pointer to member level is ignored when determining if a const
6670 cv-qualifier has been cast away. */
6671 /* [expr.const.cast]
6673 For two pointer types:
6675 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6676 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6679 casting from X1 to X2 casts away constness if, for a non-pointer
6680 type T there does not exist an implicit conversion (clause
6683 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6687 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6688 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6689 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6691 *t1 = cp_build_qualified_type (void_type_node,
6692 cp_type_quals (*t1));
6693 *t2 = cp_build_qualified_type (void_type_node,
6694 cp_type_quals (*t2));
6698 quals1 = cp_type_quals (*t1);
6699 quals2 = cp_type_quals (*t2);
6701 if (TYPE_PTRMEM_P (*t1))
6702 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6704 *t1 = TREE_TYPE (*t1);
6705 if (TYPE_PTRMEM_P (*t2))
6706 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6708 *t2 = TREE_TYPE (*t2);
6710 casts_away_constness_r (t1, t2);
6711 *t1 = build_pointer_type (*t1);
6712 *t2 = build_pointer_type (*t2);
6713 *t1 = cp_build_qualified_type (*t1, quals1);
6714 *t2 = cp_build_qualified_type (*t2, quals2);
6717 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6721 casts_away_constness (tree t1, tree t2)
6723 if (TREE_CODE (t2) == REFERENCE_TYPE)
6725 /* [expr.const.cast]
6727 Casting from an lvalue of type T1 to an lvalue of type T2
6728 using a reference cast casts away constness if a cast from an
6729 rvalue of type "pointer to T1" to the type "pointer to T2"
6730 casts away constness. */
6731 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6732 return casts_away_constness (build_pointer_type (t1),
6733 build_pointer_type (TREE_TYPE (t2)));
6736 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6737 /* [expr.const.cast]
6739 Casting from an rvalue of type "pointer to data member of X
6740 of type T1" to the type "pointer to data member of Y of type
6741 T2" casts away constness if a cast from an rvalue of type
6742 "pointer to T1" to the type "pointer to T2" casts away
6744 return casts_away_constness
6745 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6746 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6748 /* Casting away constness is only something that makes sense for
6749 pointer or reference types. */
6750 if (TREE_CODE (t1) != POINTER_TYPE
6751 || TREE_CODE (t2) != POINTER_TYPE)
6754 /* Top-level qualifiers don't matter. */
6755 t1 = TYPE_MAIN_VARIANT (t1);
6756 t2 = TYPE_MAIN_VARIANT (t2);
6757 casts_away_constness_r (&t1, &t2);
6758 if (!can_convert (t2, t1))
6764 /* If T is a REFERENCE_TYPE return the type to which T refers.
6765 Otherwise, return T itself. */
6768 non_reference (tree t)
6770 if (TREE_CODE (t) == REFERENCE_TYPE)
6776 /* Return nonzero if REF is an lvalue valid for this language;
6777 otherwise, print an error message and return zero. USE says
6778 how the lvalue is being used and so selects the error message. */
6781 lvalue_or_else (tree ref, enum lvalue_use use)
6783 int win = lvalue_p (ref);