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_type))
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'
1990 has already been looked up; it is either a TYPE or a
1992 scope = TREE_OPERAND (name, 0);
1993 name = TREE_OPERAND (name, 1);
1995 /* If SCOPE is a namespace, then the qualified name does not
1996 name a member of OBJECT_TYPE. */
1997 if (TREE_CODE (scope) == NAMESPACE_DECL)
1999 error ("%<%D::%D%> is not a member of %qT",
2000 scope, name, object_type);
2001 return error_mark_node;
2004 gcc_assert (CLASS_TYPE_P (scope));
2005 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2006 || TREE_CODE (name) == BIT_NOT_EXPR);
2008 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2009 access_path = lookup_base (object_type, scope, ba_check, NULL);
2010 if (access_path == error_mark_node)
2011 return error_mark_node;
2014 error ("%qT is not a base of %qT", scope, object_type);
2015 return error_mark_node;
2021 access_path = object_type;
2024 if (TREE_CODE (name) == BIT_NOT_EXPR)
2025 member = lookup_destructor (object, scope, name);
2028 /* Look up the member. */
2029 member = lookup_member (access_path, name, /*protect=*/1,
2030 /*want_type=*/false);
2031 if (member == NULL_TREE)
2033 error ("%qD has no member named %qE", object_type, name);
2034 return error_mark_node;
2036 if (member == error_mark_node)
2037 return error_mark_node;
2042 tree template = member;
2044 if (BASELINK_P (template))
2045 template = lookup_template_function (template, template_args);
2048 error ("%qD is not a member template function", name);
2049 return error_mark_node;
2054 if (TREE_DEPRECATED (member))
2055 warn_deprecated_use (member);
2058 check_template_keyword (member);
2060 expr = build_class_member_access_expr (object, member, access_path,
2061 /*preserve_reference=*/false);
2062 if (processing_template_decl && expr != error_mark_node)
2064 if (BASELINK_P (member))
2066 if (TREE_CODE (orig_name) == SCOPE_REF)
2067 BASELINK_QUALIFIED_P (member) = 1;
2070 return build_min_non_dep (COMPONENT_REF, expr,
2071 orig_object, orig_name,
2078 /* Return an expression for the MEMBER_NAME field in the internal
2079 representation of PTRMEM, a pointer-to-member function. (Each
2080 pointer-to-member function type gets its own RECORD_TYPE so it is
2081 more convenient to access the fields by name than by FIELD_DECL.)
2082 This routine converts the NAME to a FIELD_DECL and then creates the
2083 node for the complete expression. */
2086 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2092 /* This code is a stripped down version of
2093 build_class_member_access_expr. It does not work to use that
2094 routine directly because it expects the object to be of class
2096 ptrmem_type = TREE_TYPE (ptrmem);
2097 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2098 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2099 /*want_type=*/false);
2100 member_type = cp_build_qualified_type (TREE_TYPE (member),
2101 cp_type_quals (ptrmem_type));
2102 return fold_build3 (COMPONENT_REF, member_type,
2103 ptrmem, member, NULL_TREE);
2106 /* Given an expression PTR for a pointer, return an expression
2107 for the value pointed to.
2108 ERRORSTRING is the name of the operator to appear in error messages.
2110 This function may need to overload OPERATOR_FNNAME.
2111 Must also handle REFERENCE_TYPEs for C++. */
2114 build_x_indirect_ref (tree expr, const char *errorstring)
2116 tree orig_expr = expr;
2119 if (processing_template_decl)
2121 if (type_dependent_expression_p (expr))
2122 return build_min_nt (INDIRECT_REF, expr);
2123 expr = build_non_dependent_expr (expr);
2126 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2127 NULL_TREE, /*overloaded_p=*/NULL);
2129 rval = build_indirect_ref (expr, errorstring);
2131 if (processing_template_decl && rval != error_mark_node)
2132 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2138 build_indirect_ref (tree ptr, const char *errorstring)
2142 if (ptr == error_mark_node)
2143 return error_mark_node;
2145 if (ptr == current_class_ptr)
2146 return current_class_ref;
2148 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2149 ? ptr : decay_conversion (ptr));
2150 type = TREE_TYPE (pointer);
2152 if (POINTER_TYPE_P (type))
2156 If the type of the expression is "pointer to T," the type
2157 of the result is "T."
2159 We must use the canonical variant because certain parts of
2160 the back end, like fold, do pointer comparisons between
2162 tree t = canonical_type_variant (TREE_TYPE (type));
2164 if (VOID_TYPE_P (t))
2166 /* A pointer to incomplete type (other than cv void) can be
2167 dereferenced [expr.unary.op]/1 */
2168 error ("%qT is not a pointer-to-object type", type);
2169 return error_mark_node;
2171 else if (TREE_CODE (pointer) == ADDR_EXPR
2172 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2173 /* The POINTER was something like `&x'. We simplify `*&x' to
2175 return TREE_OPERAND (pointer, 0);
2178 tree ref = build1 (INDIRECT_REF, t, pointer);
2180 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2181 so that we get the proper error message if the result is used
2182 to assign to. Also, &* is supposed to be a no-op. */
2183 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2184 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2185 TREE_SIDE_EFFECTS (ref)
2186 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2190 /* `pointer' won't be an error_mark_node if we were given a
2191 pointer to member, so it's cool to check for this here. */
2192 else if (TYPE_PTR_TO_MEMBER_P (type))
2193 error ("invalid use of %qs on pointer to member", errorstring);
2194 else if (pointer != error_mark_node)
2197 error ("invalid type argument of %qs", errorstring);
2199 error ("invalid type argument");
2201 return error_mark_node;
2204 /* This handles expressions of the form "a[i]", which denotes
2207 This is logically equivalent in C to *(a+i), but we may do it differently.
2208 If A is a variable or a member, we generate a primitive ARRAY_REF.
2209 This avoids forcing the array out of registers, and can work on
2210 arrays that are not lvalues (for example, members of structures returned
2213 If INDEX is of some user-defined type, it must be converted to
2214 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2215 will inherit the type of the array, which will be some pointer type. */
2218 build_array_ref (tree array, tree idx)
2222 error ("subscript missing in array reference");
2223 return error_mark_node;
2226 if (TREE_TYPE (array) == error_mark_node
2227 || TREE_TYPE (idx) == error_mark_node)
2228 return error_mark_node;
2230 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2232 switch (TREE_CODE (array))
2236 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2237 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2238 TREE_OPERAND (array, 0), value);
2242 return build_conditional_expr
2243 (TREE_OPERAND (array, 0),
2244 build_array_ref (TREE_OPERAND (array, 1), idx),
2245 build_array_ref (TREE_OPERAND (array, 2), idx));
2251 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2255 /* Subscripting with type char is likely to lose
2256 on a machine where chars are signed.
2257 So warn on any machine, but optionally.
2258 Don't warn for unsigned char since that type is safe.
2259 Don't warn for signed char because anyone who uses that
2260 must have done so deliberately. */
2261 if (warn_char_subscripts
2262 && TYPE_MAIN_VARIANT (TREE_TYPE (idx)) == char_type_node)
2263 warning (0, "array subscript has type %<char%>");
2265 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2267 error ("array subscript is not an integer");
2268 return error_mark_node;
2271 /* Apply integral promotions *after* noticing character types.
2272 (It is unclear why we do these promotions -- the standard
2273 does not say that we should. In fact, the natural thing would
2274 seem to be to convert IDX to ptrdiff_t; we're performing
2275 pointer arithmetic.) */
2276 idx = perform_integral_promotions (idx);
2278 /* An array that is indexed by a non-constant
2279 cannot be stored in a register; we must be able to do
2280 address arithmetic on its address.
2281 Likewise an array of elements of variable size. */
2282 if (TREE_CODE (idx) != INTEGER_CST
2283 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2284 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2287 if (!cxx_mark_addressable (array))
2288 return error_mark_node;
2291 /* An array that is indexed by a constant value which is not within
2292 the array bounds cannot be stored in a register either; because we
2293 would get a crash in store_bit_field/extract_bit_field when trying
2294 to access a non-existent part of the register. */
2295 if (TREE_CODE (idx) == INTEGER_CST
2296 && TYPE_DOMAIN (TREE_TYPE (array))
2297 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2299 if (!cxx_mark_addressable (array))
2300 return error_mark_node;
2303 if (pedantic && !lvalue_p (array))
2304 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2306 /* Note in C++ it is valid to subscript a `register' array, since
2307 it is valid to take the address of something with that
2308 storage specification. */
2312 while (TREE_CODE (foo) == COMPONENT_REF)
2313 foo = TREE_OPERAND (foo, 0);
2314 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2315 warning (0, "subscripting array declared %<register%>");
2318 type = TREE_TYPE (TREE_TYPE (array));
2319 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2320 /* Array ref is const/volatile if the array elements are
2321 or if the array is.. */
2322 TREE_READONLY (rval)
2323 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2324 TREE_SIDE_EFFECTS (rval)
2325 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2326 TREE_THIS_VOLATILE (rval)
2327 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2328 return require_complete_type (fold_if_not_in_template (rval));
2332 tree ar = default_conversion (array);
2333 tree ind = default_conversion (idx);
2335 /* Put the integer in IND to simplify error checking. */
2336 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2343 if (ar == error_mark_node)
2346 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2348 error ("subscripted value is neither array nor pointer");
2349 return error_mark_node;
2351 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2353 error ("array subscript is not an integer");
2354 return error_mark_node;
2357 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2362 /* Resolve a pointer to member function. INSTANCE is the object
2363 instance to use, if the member points to a virtual member.
2365 This used to avoid checking for virtual functions if basetype
2366 has no virtual functions, according to an earlier ANSI draft.
2367 With the final ISO C++ rules, such an optimization is
2368 incorrect: A pointer to a derived member can be static_cast
2369 to pointer-to-base-member, as long as the dynamic object
2370 later has the right member. */
2373 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2375 if (TREE_CODE (function) == OFFSET_REF)
2376 function = TREE_OPERAND (function, 1);
2378 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2380 tree idx, delta, e1, e2, e3, vtbl, basetype;
2381 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2383 tree instance_ptr = *instance_ptrptr;
2384 tree instance_save_expr = 0;
2385 if (instance_ptr == error_mark_node)
2387 if (TREE_CODE (function) == PTRMEM_CST)
2389 /* Extracting the function address from a pmf is only
2390 allowed with -Wno-pmf-conversions. It only works for
2392 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2393 e1 = convert (fntype, e1);
2398 error ("object missing in use of %qE", function);
2399 return error_mark_node;
2403 if (TREE_SIDE_EFFECTS (instance_ptr))
2404 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2406 if (TREE_SIDE_EFFECTS (function))
2407 function = save_expr (function);
2409 /* Start by extracting all the information from the PMF itself. */
2410 e3 = pfn_from_ptrmemfunc (function);
2411 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2412 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2413 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2415 case ptrmemfunc_vbit_in_pfn:
2416 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2417 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2420 case ptrmemfunc_vbit_in_delta:
2421 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2422 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2429 /* Convert down to the right base before using the instance. A
2430 special case is that in a pointer to member of class C, C may
2431 be incomplete. In that case, the function will of course be
2432 a member of C, and no conversion is required. In fact,
2433 lookup_base will fail in that case, because incomplete
2434 classes do not have BINFOs. */
2435 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2436 if (!same_type_ignoring_top_level_qualifiers_p
2437 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2439 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2440 basetype, ba_check, NULL);
2441 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2443 if (instance_ptr == error_mark_node)
2444 return error_mark_node;
2446 /* ...and then the delta in the PMF. */
2447 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2448 instance_ptr, delta);
2450 /* Hand back the adjusted 'this' argument to our caller. */
2451 *instance_ptrptr = instance_ptr;
2453 /* Next extract the vtable pointer from the object. */
2454 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2456 vtbl = build_indirect_ref (vtbl, NULL);
2458 /* Finally, extract the function pointer from the vtable. */
2459 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2460 e2 = build_indirect_ref (e2, NULL);
2461 TREE_CONSTANT (e2) = 1;
2462 TREE_INVARIANT (e2) = 1;
2464 /* When using function descriptors, the address of the
2465 vtable entry is treated as a function pointer. */
2466 if (TARGET_VTABLE_USES_DESCRIPTORS)
2467 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2468 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2470 TREE_TYPE (e2) = TREE_TYPE (e3);
2471 e1 = build_conditional_expr (e1, e2, e3);
2473 /* Make sure this doesn't get evaluated first inside one of the
2474 branches of the COND_EXPR. */
2475 if (instance_save_expr)
2476 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2477 instance_save_expr, e1);
2485 build_function_call (tree function, tree params)
2487 tree fntype, fndecl;
2488 tree coerced_params;
2489 tree name = NULL_TREE;
2491 tree original = function;
2493 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2494 expressions, like those used for ObjC messenger dispatches. */
2495 function = objc_rewrite_function_call (function, params);
2497 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2498 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2499 if (TREE_CODE (function) == NOP_EXPR
2500 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2501 function = TREE_OPERAND (function, 0);
2503 if (TREE_CODE (function) == FUNCTION_DECL)
2505 name = DECL_NAME (function);
2507 mark_used (function);
2510 /* Convert anything with function type to a pointer-to-function. */
2511 if (pedantic && DECL_MAIN_P (function))
2512 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2514 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2515 (because calling an inline function does not mean the function
2516 needs to be separately compiled). */
2518 if (DECL_INLINE (function))
2519 function = inline_conversion (function);
2521 function = build_addr_func (function);
2527 function = build_addr_func (function);
2530 if (function == error_mark_node)
2531 return error_mark_node;
2533 fntype = TREE_TYPE (function);
2535 if (TYPE_PTRMEMFUNC_P (fntype))
2537 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2538 "function in %<%E (...)%>",
2540 return error_mark_node;
2543 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2544 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2546 if (!((TREE_CODE (fntype) == POINTER_TYPE
2547 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2549 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2551 error ("%qE cannot be used as a function", original);
2552 return error_mark_node;
2555 /* fntype now gets the type of function pointed to. */
2556 fntype = TREE_TYPE (fntype);
2558 /* Convert the parameters to the types declared in the
2559 function prototype, or apply default promotions. */
2561 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2562 params, fndecl, LOOKUP_NORMAL);
2563 if (coerced_params == error_mark_node)
2564 return error_mark_node;
2566 /* Check for errors in format strings and inappropriately
2569 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2570 TYPE_ARG_TYPES (fntype));
2572 return build_cxx_call (function, coerced_params);
2575 /* Convert the actual parameter expressions in the list VALUES
2576 to the types in the list TYPELIST.
2577 If parmdecls is exhausted, or when an element has NULL as its type,
2578 perform the default conversions.
2580 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2582 This is also where warnings about wrong number of args are generated.
2584 Return a list of expressions for the parameters as converted.
2586 Both VALUES and the returned value are chains of TREE_LIST nodes
2587 with the elements of the list in the TREE_VALUE slots of those nodes.
2589 In C++, unspecified trailing parameters can be filled in with their
2590 default arguments, if such were specified. Do so here. */
2593 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2595 tree typetail, valtail;
2596 tree result = NULL_TREE;
2597 const char *called_thing = 0;
2600 /* Argument passing is always copy-initialization. */
2601 flags |= LOOKUP_ONLYCONVERTING;
2605 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2607 if (DECL_NAME (fndecl) == NULL_TREE
2608 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2609 called_thing = "constructor";
2611 called_thing = "member function";
2614 called_thing = "function";
2617 for (valtail = values, typetail = typelist;
2619 valtail = TREE_CHAIN (valtail), i++)
2621 tree type = typetail ? TREE_VALUE (typetail) : 0;
2622 tree val = TREE_VALUE (valtail);
2624 if (val == error_mark_node || type == error_mark_node)
2625 return error_mark_node;
2627 if (type == void_type_node)
2631 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2632 error ("at this point in file");
2635 error ("too many arguments to function");
2636 /* In case anybody wants to know if this argument
2639 TREE_TYPE (tree_last (result)) = error_mark_node;
2643 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2644 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2645 if (TREE_CODE (val) == NOP_EXPR
2646 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2647 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2648 val = TREE_OPERAND (val, 0);
2650 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2652 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2653 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2654 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2655 val = decay_conversion (val);
2658 if (val == error_mark_node)
2659 return error_mark_node;
2663 /* Formal parm type is specified by a function prototype. */
2666 if (!COMPLETE_TYPE_P (complete_type (type)))
2669 error ("parameter %P of %qD has incomplete type %qT",
2672 error ("parameter %P has incomplete type %qT", i, type);
2673 parmval = error_mark_node;
2677 parmval = convert_for_initialization
2678 (NULL_TREE, type, val, flags,
2679 "argument passing", fndecl, i);
2680 parmval = convert_for_arg_passing (type, parmval);
2683 if (parmval == error_mark_node)
2684 return error_mark_node;
2686 result = tree_cons (NULL_TREE, parmval, result);
2690 if (fndecl && DECL_BUILT_IN (fndecl)
2691 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2692 /* Don't do ellipsis conversion for __built_in_constant_p
2693 as this will result in spurious warnings for non-POD
2695 val = require_complete_type (val);
2697 val = convert_arg_to_ellipsis (val);
2699 result = tree_cons (NULL_TREE, val, result);
2703 typetail = TREE_CHAIN (typetail);
2706 if (typetail != 0 && typetail != void_list_node)
2708 /* See if there are default arguments that can be used. */
2709 if (TREE_PURPOSE (typetail)
2710 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2712 for (; typetail != void_list_node; ++i)
2715 = convert_default_arg (TREE_VALUE (typetail),
2716 TREE_PURPOSE (typetail),
2719 if (parmval == error_mark_node)
2720 return error_mark_node;
2722 result = tree_cons (0, parmval, result);
2723 typetail = TREE_CHAIN (typetail);
2724 /* ends with `...'. */
2725 if (typetail == NULL_TREE)
2733 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2734 error ("at this point in file");
2737 error ("too few arguments to function");
2738 return error_mark_node;
2742 return nreverse (result);
2745 /* Build a binary-operation expression, after performing default
2746 conversions on the operands. CODE is the kind of expression to build. */
2749 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2759 if (processing_template_decl)
2761 if (type_dependent_expression_p (arg1)
2762 || type_dependent_expression_p (arg2))
2763 return build_min_nt (code, arg1, arg2);
2764 arg1 = build_non_dependent_expr (arg1);
2765 arg2 = build_non_dependent_expr (arg2);
2768 if (code == DOTSTAR_EXPR)
2769 expr = build_m_component_ref (arg1, arg2);
2771 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2774 if (processing_template_decl && expr != error_mark_node)
2775 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2780 /* Build a binary-operation expression without default conversions.
2781 CODE is the kind of expression to build.
2782 This function differs from `build' in several ways:
2783 the data type of the result is computed and recorded in it,
2784 warnings are generated if arg data types are invalid,
2785 special handling for addition and subtraction of pointers is known,
2786 and some optimization is done (operations on narrow ints
2787 are done in the narrower type when that gives the same result).
2788 Constant folding is also done before the result is returned.
2790 Note that the operands will never have enumeral types
2791 because either they have just had the default conversions performed
2792 or they have both just been converted to some other type in which
2793 the arithmetic is to be done.
2795 C++: must do special pointer arithmetic when implementing
2796 multiple inheritance, and deal with pointer to member functions. */
2799 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2800 int convert_p ATTRIBUTE_UNUSED)
2803 enum tree_code code0, code1;
2805 const char *invalid_op_diag;
2807 /* Expression code to give to the expression when it is built.
2808 Normally this is CODE, which is what the caller asked for,
2809 but in some special cases we change it. */
2810 enum tree_code resultcode = code;
2812 /* Data type in which the computation is to be performed.
2813 In the simplest cases this is the common type of the arguments. */
2814 tree result_type = NULL;
2816 /* Nonzero means operands have already been type-converted
2817 in whatever way is necessary.
2818 Zero means they need to be converted to RESULT_TYPE. */
2821 /* Nonzero means create the expression with this type, rather than
2823 tree build_type = 0;
2825 /* Nonzero means after finally constructing the expression
2826 convert it to this type. */
2827 tree final_type = 0;
2831 /* Nonzero if this is an operation like MIN or MAX which can
2832 safely be computed in short if both args are promoted shorts.
2833 Also implies COMMON.
2834 -1 indicates a bitwise operation; this makes a difference
2835 in the exact conditions for when it is safe to do the operation
2836 in a narrower mode. */
2839 /* Nonzero if this is a comparison operation;
2840 if both args are promoted shorts, compare the original shorts.
2841 Also implies COMMON. */
2842 int short_compare = 0;
2844 /* Nonzero if this is a right-shift operation, which can be computed on the
2845 original short and then promoted if the operand is a promoted short. */
2846 int short_shift = 0;
2848 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2851 /* True if both operands have arithmetic type. */
2852 bool arithmetic_types_p;
2854 /* Apply default conversions. */
2858 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2859 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2860 || code == TRUTH_XOR_EXPR)
2862 if (!really_overloaded_fn (op0))
2863 op0 = decay_conversion (op0);
2864 if (!really_overloaded_fn (op1))
2865 op1 = decay_conversion (op1);
2869 if (!really_overloaded_fn (op0))
2870 op0 = default_conversion (op0);
2871 if (!really_overloaded_fn (op1))
2872 op1 = default_conversion (op1);
2875 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2876 STRIP_TYPE_NOPS (op0);
2877 STRIP_TYPE_NOPS (op1);
2879 /* DTRT if one side is an overloaded function, but complain about it. */
2880 if (type_unknown_p (op0))
2882 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
2883 if (t != error_mark_node)
2885 pedwarn ("assuming cast to type %qT from overloaded function",
2890 if (type_unknown_p (op1))
2892 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
2893 if (t != error_mark_node)
2895 pedwarn ("assuming cast to type %qT from overloaded function",
2901 type0 = TREE_TYPE (op0);
2902 type1 = TREE_TYPE (op1);
2904 /* The expression codes of the data types of the arguments tell us
2905 whether the arguments are integers, floating, pointers, etc. */
2906 code0 = TREE_CODE (type0);
2907 code1 = TREE_CODE (type1);
2909 /* If an error was already reported for one of the arguments,
2910 avoid reporting another error. */
2912 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
2913 return error_mark_node;
2915 if ((invalid_op_diag
2916 = targetm.invalid_binary_op (code, type0, type1)))
2918 error (invalid_op_diag);
2919 return error_mark_node;
2925 /* Handle the pointer + int case. */
2926 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2927 return cp_pointer_int_sum (PLUS_EXPR, op0, op1);
2928 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
2929 return cp_pointer_int_sum (PLUS_EXPR, op1, op0);
2935 /* Subtraction of two similar pointers.
2936 We must subtract them as integers, then divide by object size. */
2937 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
2938 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
2940 return pointer_diff (op0, op1, common_type (type0, type1));
2941 /* Handle pointer minus int. Just like pointer plus int. */
2942 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2943 return cp_pointer_int_sum (MINUS_EXPR, op0, op1);
2952 case TRUNC_DIV_EXPR:
2954 case FLOOR_DIV_EXPR:
2955 case ROUND_DIV_EXPR:
2956 case EXACT_DIV_EXPR:
2957 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2958 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2959 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2960 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
2962 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
2963 warning (0, "division by zero in %<%E / 0%>", op0);
2964 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
2965 warning (0, "division by zero in %<%E / 0.%>", op0);
2967 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
2968 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
2969 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
2970 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
2972 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2973 resultcode = RDIV_EXPR;
2975 /* When dividing two signed integers, we have to promote to int.
2976 unless we divide by a constant != -1. Note that default
2977 conversion will have been performed on the operands at this
2978 point, so we have to dig out the original type to find out if
2980 shorten = ((TREE_CODE (op0) == NOP_EXPR
2981 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
2982 || (TREE_CODE (op1) == INTEGER_CST
2983 && ! integer_all_onesp (op1)));
2992 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2993 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
2997 case TRUNC_MOD_EXPR:
2998 case FLOOR_MOD_EXPR:
2999 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3000 warning (0, "division by zero in %<%E %% 0%>", op0);
3001 else if (code1 == REAL_TYPE && real_zerop (op1))
3002 warning (0, "division by zero in %<%E %% 0.%>", op0);
3004 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3006 /* Although it would be tempting to shorten always here, that loses
3007 on some targets, since the modulo instruction is undefined if the
3008 quotient can't be represented in the computation mode. We shorten
3009 only if unsigned or if dividing by something we know != -1. */
3010 shorten = ((TREE_CODE (op0) == NOP_EXPR
3011 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3012 || (TREE_CODE (op1) == INTEGER_CST
3013 && ! integer_all_onesp (op1)));
3018 case TRUTH_ANDIF_EXPR:
3019 case TRUTH_ORIF_EXPR:
3020 case TRUTH_AND_EXPR:
3022 result_type = boolean_type_node;
3025 /* Shift operations: result has same type as first operand;
3026 always convert second operand to int.
3027 Also set SHORT_SHIFT if shifting rightward. */
3030 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3032 result_type = type0;
3033 if (TREE_CODE (op1) == INTEGER_CST)
3035 if (tree_int_cst_lt (op1, integer_zero_node))
3036 warning (0, "right shift count is negative");
3039 if (! integer_zerop (op1))
3041 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3042 warning (0, "right shift count >= width of type");
3045 /* Convert the shift-count to an integer, regardless of
3046 size of value being shifted. */
3047 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3048 op1 = cp_convert (integer_type_node, op1);
3049 /* Avoid converting op1 to result_type later. */
3055 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3057 result_type = type0;
3058 if (TREE_CODE (op1) == INTEGER_CST)
3060 if (tree_int_cst_lt (op1, integer_zero_node))
3061 warning (0, "left shift count is negative");
3062 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3063 warning (0, "left shift count >= width of type");
3065 /* Convert the shift-count to an integer, regardless of
3066 size of value being shifted. */
3067 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3068 op1 = cp_convert (integer_type_node, op1);
3069 /* Avoid converting op1 to result_type later. */
3076 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3078 result_type = type0;
3079 if (TREE_CODE (op1) == INTEGER_CST)
3081 if (tree_int_cst_lt (op1, integer_zero_node))
3082 warning (0, "%s rotate count is negative",
3083 (code == LROTATE_EXPR) ? "left" : "right");
3084 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3085 warning (0, "%s rotate count >= width of type",
3086 (code == LROTATE_EXPR) ? "left" : "right");
3088 /* Convert the shift-count to an integer, regardless of
3089 size of value being shifted. */
3090 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3091 op1 = cp_convert (integer_type_node, op1);
3097 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
3098 warning (0, "comparing floating point with == or != is unsafe");
3100 build_type = boolean_type_node;
3101 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3102 || code0 == COMPLEX_TYPE)
3103 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3104 || code1 == COMPLEX_TYPE))
3106 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3107 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3108 result_type = composite_pointer_type (type0, type1, op0, op1,
3110 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3111 && null_ptr_cst_p (op1))
3112 result_type = type0;
3113 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3114 && null_ptr_cst_p (op0))
3115 result_type = type1;
3116 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3118 result_type = type0;
3119 error ("ISO C++ forbids comparison between pointer and integer");
3121 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3123 result_type = type1;
3124 error ("ISO C++ forbids comparison between pointer and integer");
3126 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3128 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3129 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3130 result_type = TREE_TYPE (op0);
3132 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3133 return cp_build_binary_op (code, op1, op0);
3134 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3135 && same_type_p (type0, type1))
3137 /* E will be the final comparison. */
3139 /* E1 and E2 are for scratch. */
3147 if (TREE_SIDE_EFFECTS (op0))
3148 op0 = save_expr (op0);
3149 if (TREE_SIDE_EFFECTS (op1))
3150 op1 = save_expr (op1);
3155 && (!op0.pfn || op0.delta == op1.delta))
3157 The reason for the `!op0.pfn' bit is that a NULL
3158 pointer-to-member is any member with a zero PFN; the
3159 DELTA field is unspecified. */
3160 pfn0 = pfn_from_ptrmemfunc (op0);
3161 pfn1 = pfn_from_ptrmemfunc (op1);
3162 delta0 = build_ptrmemfunc_access_expr (op0,
3164 delta1 = build_ptrmemfunc_access_expr (op1,
3166 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3167 e2 = cp_build_binary_op (EQ_EXPR,
3169 cp_convert (TREE_TYPE (pfn0),
3170 integer_zero_node));
3171 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3172 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3173 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3174 if (code == EQ_EXPR)
3176 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3180 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3181 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3183 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3184 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3192 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3193 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3195 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3196 result_type = composite_pointer_type (type0, type1, op0, op1,
3204 build_type = boolean_type_node;
3205 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3206 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3208 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3209 result_type = composite_pointer_type (type0, type1, op0, op1,
3211 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3212 && integer_zerop (op1))
3213 result_type = type0;
3214 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3215 && integer_zerop (op0))
3216 result_type = type1;
3217 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3219 result_type = type0;
3220 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3222 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3224 result_type = type1;
3225 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3229 case UNORDERED_EXPR:
3236 build_type = integer_type_node;
3237 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3239 error ("unordered comparison on non-floating point argument");
3240 return error_mark_node;
3249 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3250 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3251 || code1 == COMPLEX_TYPE)))
3252 arithmetic_types_p = 1;
3255 arithmetic_types_p = 0;
3256 /* Vector arithmetic is only allowed when both sides are vectors. */
3257 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3259 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3260 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3263 binary_op_error (code);
3264 return error_mark_node;
3266 arithmetic_types_p = 1;
3269 /* Determine the RESULT_TYPE, if it is not already known. */
3271 && arithmetic_types_p
3272 && (shorten || common || short_compare))
3273 result_type = common_type (type0, type1);
3277 error ("invalid operands of types %qT and %qT to binary %qO",
3278 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3279 return error_mark_node;
3282 /* If we're in a template, the only thing we need to know is the
3284 if (processing_template_decl)
3285 return build2 (resultcode,
3286 build_type ? build_type : result_type,
3289 if (arithmetic_types_p)
3291 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3293 /* For certain operations (which identify themselves by shorten != 0)
3294 if both args were extended from the same smaller type,
3295 do the arithmetic in that type and then extend.
3297 shorten !=0 and !=1 indicates a bitwise operation.
3298 For them, this optimization is safe only if
3299 both args are zero-extended or both are sign-extended.
3300 Otherwise, we might change the result.
3301 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3302 but calculated in (unsigned short) it would be (unsigned short)-1. */
3304 if (shorten && none_complex)
3306 int unsigned0, unsigned1;
3307 tree arg0 = get_narrower (op0, &unsigned0);
3308 tree arg1 = get_narrower (op1, &unsigned1);
3309 /* UNS is 1 if the operation to be done is an unsigned one. */
3310 int uns = TYPE_UNSIGNED (result_type);
3313 final_type = result_type;
3315 /* Handle the case that OP0 does not *contain* a conversion
3316 but it *requires* conversion to FINAL_TYPE. */
3318 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3319 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3320 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3321 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3323 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3325 /* For bitwise operations, signedness of nominal type
3326 does not matter. Consider only how operands were extended. */
3330 /* Note that in all three cases below we refrain from optimizing
3331 an unsigned operation on sign-extended args.
3332 That would not be valid. */
3334 /* Both args variable: if both extended in same way
3335 from same width, do it in that width.
3336 Do it unsigned if args were zero-extended. */
3337 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3338 < TYPE_PRECISION (result_type))
3339 && (TYPE_PRECISION (TREE_TYPE (arg1))
3340 == TYPE_PRECISION (TREE_TYPE (arg0)))
3341 && unsigned0 == unsigned1
3342 && (unsigned0 || !uns))
3343 result_type = c_common_signed_or_unsigned_type
3344 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3345 else if (TREE_CODE (arg0) == INTEGER_CST
3346 && (unsigned1 || !uns)
3347 && (TYPE_PRECISION (TREE_TYPE (arg1))
3348 < TYPE_PRECISION (result_type))
3349 && (type = c_common_signed_or_unsigned_type
3350 (unsigned1, TREE_TYPE (arg1)),
3351 int_fits_type_p (arg0, type)))
3353 else if (TREE_CODE (arg1) == INTEGER_CST
3354 && (unsigned0 || !uns)
3355 && (TYPE_PRECISION (TREE_TYPE (arg0))
3356 < TYPE_PRECISION (result_type))
3357 && (type = c_common_signed_or_unsigned_type
3358 (unsigned0, TREE_TYPE (arg0)),
3359 int_fits_type_p (arg1, type)))
3363 /* Shifts can be shortened if shifting right. */
3368 tree arg0 = get_narrower (op0, &unsigned_arg);
3370 final_type = result_type;
3372 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3373 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3375 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3376 /* We can shorten only if the shift count is less than the
3377 number of bits in the smaller type size. */
3378 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3379 /* If arg is sign-extended and then unsigned-shifted,
3380 we can simulate this with a signed shift in arg's type
3381 only if the extended result is at least twice as wide
3382 as the arg. Otherwise, the shift could use up all the
3383 ones made by sign-extension and bring in zeros.
3384 We can't optimize that case at all, but in most machines
3385 it never happens because available widths are 2**N. */
3386 && (!TYPE_UNSIGNED (final_type)
3388 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3389 <= TYPE_PRECISION (result_type))))
3391 /* Do an unsigned shift if the operand was zero-extended. */
3393 = c_common_signed_or_unsigned_type (unsigned_arg,
3395 /* Convert value-to-be-shifted to that type. */
3396 if (TREE_TYPE (op0) != result_type)
3397 op0 = cp_convert (result_type, op0);
3402 /* Comparison operations are shortened too but differently.
3403 They identify themselves by setting short_compare = 1. */
3407 /* Don't write &op0, etc., because that would prevent op0
3408 from being kept in a register.
3409 Instead, make copies of the our local variables and
3410 pass the copies by reference, then copy them back afterward. */
3411 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3412 enum tree_code xresultcode = resultcode;
3414 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3416 return cp_convert (boolean_type_node, val);
3417 op0 = xop0, op1 = xop1;
3419 resultcode = xresultcode;
3422 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3423 && warn_sign_compare
3424 /* Do not warn until the template is instantiated; we cannot
3425 bound the ranges of the arguments until that point. */
3426 && !processing_template_decl)
3428 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3429 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3431 int unsignedp0, unsignedp1;
3432 tree primop0 = get_narrower (op0, &unsignedp0);
3433 tree primop1 = get_narrower (op1, &unsignedp1);
3435 /* Check for comparison of different enum types. */
3436 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3437 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3438 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3439 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3441 warning (0, "comparison between types %q#T and %q#T",
3442 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3445 /* Give warnings for comparisons between signed and unsigned
3446 quantities that may fail. */
3447 /* Do the checking based on the original operand trees, so that
3448 casts will be considered, but default promotions won't be. */
3450 /* Do not warn if the comparison is being done in a signed type,
3451 since the signed type will only be chosen if it can represent
3452 all the values of the unsigned type. */
3453 if (!TYPE_UNSIGNED (result_type))
3455 /* Do not warn if both operands are unsigned. */
3456 else if (op0_signed == op1_signed)
3458 /* Do not warn if the signed quantity is an unsuffixed
3459 integer literal (or some static constant expression
3460 involving such literals or a conditional expression
3461 involving such literals) and it is non-negative. */
3462 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3463 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3465 /* Do not warn if the comparison is an equality operation,
3466 the unsigned quantity is an integral constant and it does
3467 not use the most significant bit of result_type. */
3468 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3469 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3470 && int_fits_type_p (orig_op1, c_common_signed_type
3472 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3473 && int_fits_type_p (orig_op0, c_common_signed_type
3477 warning (0, "comparison between signed and unsigned integer expressions");
3479 /* Warn if two unsigned values are being compared in a size
3480 larger than their original size, and one (and only one) is the
3481 result of a `~' operator. This comparison will always fail.
3483 Also warn if one operand is a constant, and the constant does not
3484 have all bits set that are set in the ~ operand when it is
3487 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3488 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3490 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3491 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3492 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3493 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3495 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3498 HOST_WIDE_INT constant, mask;
3502 if (host_integerp (primop0, 0))
3505 unsignedp = unsignedp1;
3506 constant = tree_low_cst (primop0, 0);
3511 unsignedp = unsignedp0;
3512 constant = tree_low_cst (primop1, 0);
3515 bits = TYPE_PRECISION (TREE_TYPE (primop));
3516 if (bits < TYPE_PRECISION (result_type)
3517 && bits < HOST_BITS_PER_LONG && unsignedp)
3519 mask = (~ (HOST_WIDE_INT) 0) << bits;
3520 if ((mask & constant) != mask)
3521 warning (0, "comparison of promoted ~unsigned with constant");
3524 else if (unsignedp0 && unsignedp1
3525 && (TYPE_PRECISION (TREE_TYPE (primop0))
3526 < TYPE_PRECISION (result_type))
3527 && (TYPE_PRECISION (TREE_TYPE (primop1))
3528 < TYPE_PRECISION (result_type)))
3529 warning (0, "comparison of promoted ~unsigned with unsigned");
3534 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3535 Then the expression will be built.
3536 It will be given type FINAL_TYPE if that is nonzero;
3537 otherwise, it will be given type RESULT_TYPE. */
3539 /* Issue warnings about peculiar, but valid, uses of NULL. */
3540 if (/* It's reasonable to use pointer values as operands of &&
3541 and ||, so NULL is no exception. */
3542 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3543 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3544 (orig_op0 == null_node
3545 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3546 /* Or vice versa. */
3547 || (orig_op1 == null_node
3548 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3549 /* Or, both are NULL and the operation was not a comparison. */
3550 || (orig_op0 == null_node && orig_op1 == null_node
3551 && code != EQ_EXPR && code != NE_EXPR)))
3552 /* Some sort of arithmetic operation involving NULL was
3553 performed. Note that pointer-difference and pointer-addition
3554 have already been handled above, and so we don't end up here in
3556 warning (0, "NULL used in arithmetic");
3560 if (TREE_TYPE (op0) != result_type)
3561 op0 = cp_convert (result_type, op0);
3562 if (TREE_TYPE (op1) != result_type)
3563 op1 = cp_convert (result_type, op1);
3565 if (op0 == error_mark_node || op1 == error_mark_node)
3566 return error_mark_node;
3569 if (build_type == NULL_TREE)
3570 build_type = result_type;
3572 result = build2 (resultcode, build_type, op0, op1);
3573 result = fold_if_not_in_template (result);
3574 if (final_type != 0)
3575 result = cp_convert (final_type, result);
3579 /* Return a tree for the sum or difference (RESULTCODE says which)
3580 of pointer PTROP and integer INTOP. */
3583 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3585 tree res_type = TREE_TYPE (ptrop);
3587 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3588 in certain circumstance (when it's valid to do so). So we need
3589 to make sure it's complete. We don't need to check here, if we
3590 can actually complete it at all, as those checks will be done in
3591 pointer_int_sum() anyway. */
3592 complete_type (TREE_TYPE (res_type));
3594 return pointer_int_sum (resultcode, ptrop,
3595 fold_if_not_in_template (intop));
3598 /* Return a tree for the difference of pointers OP0 and OP1.
3599 The resulting tree has type int. */
3602 pointer_diff (tree op0, tree op1, tree ptrtype)
3605 tree restype = ptrdiff_type_node;
3606 tree target_type = TREE_TYPE (ptrtype);
3608 if (!complete_type_or_else (target_type, NULL_TREE))
3609 return error_mark_node;
3611 if (pedantic || warn_pointer_arith)
3613 if (TREE_CODE (target_type) == VOID_TYPE)
3614 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3615 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3616 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3617 if (TREE_CODE (target_type) == METHOD_TYPE)
3618 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3621 /* First do the subtraction as integers;
3622 then drop through to build the divide operator. */
3624 op0 = cp_build_binary_op (MINUS_EXPR,
3625 cp_convert (restype, op0),
3626 cp_convert (restype, op1));
3628 /* This generates an error if op1 is a pointer to an incomplete type. */
3629 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3630 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3632 op1 = (TYPE_PTROB_P (ptrtype)
3633 ? size_in_bytes (target_type)
3634 : integer_one_node);
3636 /* Do the division. */
3638 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3639 return fold_if_not_in_template (result);
3642 /* Construct and perhaps optimize a tree representation
3643 for a unary operation. CODE, a tree_code, specifies the operation
3644 and XARG is the operand. */
3647 build_x_unary_op (enum tree_code code, tree xarg)
3649 tree orig_expr = xarg;
3653 if (processing_template_decl)
3655 if (type_dependent_expression_p (xarg))
3656 return build_min_nt (code, xarg, NULL_TREE);
3658 xarg = build_non_dependent_expr (xarg);
3663 /* [expr.unary.op] says:
3665 The address of an object of incomplete type can be taken.
3667 (And is just the ordinary address operator, not an overloaded
3668 "operator &".) However, if the type is a template
3669 specialization, we must complete the type at this point so that
3670 an overloaded "operator &" will be available if required. */
3671 if (code == ADDR_EXPR
3672 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3673 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3674 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3675 || (TREE_CODE (xarg) == OFFSET_REF)))
3676 /* Don't look for a function. */;
3678 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3679 /*overloaded_p=*/NULL);
3680 if (!exp && code == ADDR_EXPR)
3682 /* A pointer to member-function can be formed only by saying
3684 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3685 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3687 if (TREE_CODE (xarg) != OFFSET_REF
3688 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3690 error ("invalid use of %qE to form a pointer-to-member-function",
3692 if (TREE_CODE (xarg) != OFFSET_REF)
3693 inform (" a qualified-id is required");
3694 return error_mark_node;
3698 error ("parenthesis around %qE cannot be used to form a"
3699 " pointer-to-member-function",
3701 PTRMEM_OK_P (xarg) = 1;
3705 if (TREE_CODE (xarg) == OFFSET_REF)
3707 ptrmem = PTRMEM_OK_P (xarg);
3709 if (!ptrmem && !flag_ms_extensions
3710 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3712 /* A single non-static member, make sure we don't allow a
3713 pointer-to-member. */
3714 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3715 TREE_OPERAND (xarg, 0),
3716 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3717 PTRMEM_OK_P (xarg) = ptrmem;
3720 else if (TREE_CODE (xarg) == TARGET_EXPR)
3721 warning (0, "taking address of temporary");
3722 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3725 if (processing_template_decl && exp != error_mark_node)
3726 exp = build_min_non_dep (code, exp, orig_expr,
3727 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3728 if (TREE_CODE (exp) == ADDR_EXPR)
3729 PTRMEM_OK_P (exp) = ptrmem;
3733 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3734 constants, where a null value is represented by an INTEGER_CST of
3738 cp_truthvalue_conversion (tree expr)
3740 tree type = TREE_TYPE (expr);
3741 if (TYPE_PTRMEM_P (type))
3742 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3744 return c_common_truthvalue_conversion (expr);
3747 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3750 condition_conversion (tree expr)
3753 if (processing_template_decl)
3755 t = perform_implicit_conversion (boolean_type_node, expr);
3756 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3760 /* Return an ADDR_EXPR giving the address of T. This function
3761 attempts no optimizations or simplifications; it is a low-level
3765 build_address (tree t)
3769 if (error_operand_p (t) || !cxx_mark_addressable (t))
3770 return error_mark_node;
3772 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3777 /* Return a NOP_EXPR converting EXPR to TYPE. */
3780 build_nop (tree type, tree expr)
3782 if (type == error_mark_node || error_operand_p (expr))
3784 return build1 (NOP_EXPR, type, expr);
3787 /* C++: Must handle pointers to members.
3789 Perhaps type instantiation should be extended to handle conversion
3790 from aggregates to types we don't yet know we want? (Or are those
3791 cases typically errors which should be reported?)
3793 NOCONVERT nonzero suppresses the default promotions
3794 (such as from short to int). */
3797 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3799 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3802 const char *errstring = NULL;
3804 const char *invalid_op_diag;
3806 if (arg == error_mark_node)
3807 return error_mark_node;
3809 if ((invalid_op_diag
3810 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
3815 error (invalid_op_diag);
3816 return error_mark_node;
3821 case UNARY_PLUS_EXPR:
3824 int flags = WANT_ARITH | WANT_ENUM;
3825 /* Unary plus (but not unary minus) is allowed on pointers. */
3826 if (code == UNARY_PLUS_EXPR)
3827 flags |= WANT_POINTER;
3828 arg = build_expr_type_conversion (flags, arg, true);
3830 errstring = (code == NEGATE_EXPR
3831 ? "wrong type argument to unary minus"
3832 : "wrong type argument to unary plus");
3835 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
3836 arg = perform_integral_promotions (arg);
3838 /* Make sure the result is not an lvalue: a unary plus or minus
3839 expression is always a rvalue. */
3846 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3850 arg = default_conversion (arg);
3852 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM,
3854 errstring = "wrong type argument to bit-complement";
3855 else if (!noconvert)
3856 arg = perform_integral_promotions (arg);
3860 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3861 errstring = "wrong type argument to abs";
3862 else if (!noconvert)
3863 arg = default_conversion (arg);
3867 /* Conjugating a real value is a no-op, but allow it anyway. */
3868 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
3869 errstring = "wrong type argument to conjugation";
3870 else if (!noconvert)
3871 arg = default_conversion (arg);
3874 case TRUTH_NOT_EXPR:
3875 arg = perform_implicit_conversion (boolean_type_node, arg);
3876 val = invert_truthvalue (arg);
3877 if (arg != error_mark_node)
3879 errstring = "in argument to unary !";
3886 if (TREE_CODE (arg) == COMPLEX_CST)
3887 return TREE_REALPART (arg);
3888 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3890 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3891 return fold_if_not_in_template (arg);
3897 if (TREE_CODE (arg) == COMPLEX_CST)
3898 return TREE_IMAGPART (arg);
3899 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3901 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3902 return fold_if_not_in_template (arg);
3905 return cp_convert (TREE_TYPE (arg), integer_zero_node);
3907 case PREINCREMENT_EXPR:
3908 case POSTINCREMENT_EXPR:
3909 case PREDECREMENT_EXPR:
3910 case POSTDECREMENT_EXPR:
3911 /* Handle complex lvalues (when permitted)
3912 by reduction to simpler cases. */
3914 val = unary_complex_lvalue (code, arg);
3918 /* Increment or decrement the real part of the value,
3919 and don't change the imaginary part. */
3920 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3924 arg = stabilize_reference (arg);
3925 real = build_unary_op (REALPART_EXPR, arg, 1);
3926 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3927 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3928 build_unary_op (code, real, 1), imag);
3931 /* Report invalid types. */
3933 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
3936 if (code == PREINCREMENT_EXPR)
3937 errstring ="no pre-increment operator for type";
3938 else if (code == POSTINCREMENT_EXPR)
3939 errstring ="no post-increment operator for type";
3940 else if (code == PREDECREMENT_EXPR)
3941 errstring ="no pre-decrement operator for type";
3943 errstring ="no post-decrement operator for type";
3947 /* Report something read-only. */
3949 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
3950 || TREE_READONLY (arg))
3951 readonly_error (arg, ((code == PREINCREMENT_EXPR
3952 || code == POSTINCREMENT_EXPR)
3953 ? "increment" : "decrement"),
3958 tree result_type = TREE_TYPE (arg);
3960 arg = get_unwidened (arg, 0);
3961 argtype = TREE_TYPE (arg);
3963 /* ARM $5.2.5 last annotation says this should be forbidden. */
3964 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
3965 pedwarn ("ISO C++ forbids %sing an enum",
3966 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3967 ? "increment" : "decrement");
3969 /* Compute the increment. */
3971 if (TREE_CODE (argtype) == POINTER_TYPE)
3973 tree type = complete_type (TREE_TYPE (argtype));
3975 if (!COMPLETE_OR_VOID_TYPE_P (type))
3976 error ("cannot %s a pointer to incomplete type %qT",
3977 ((code == PREINCREMENT_EXPR
3978 || code == POSTINCREMENT_EXPR)
3979 ? "increment" : "decrement"), TREE_TYPE (argtype));
3980 else if ((pedantic || warn_pointer_arith)
3981 && !TYPE_PTROB_P (argtype))
3982 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
3983 ((code == PREINCREMENT_EXPR
3984 || code == POSTINCREMENT_EXPR)
3985 ? "increment" : "decrement"), argtype);
3986 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
3989 inc = integer_one_node;
3991 inc = cp_convert (argtype, inc);
3993 /* Handle incrementing a cast-expression. */
3995 switch (TREE_CODE (arg))
4000 case FIX_TRUNC_EXPR:
4001 case FIX_FLOOR_EXPR:
4002 case FIX_ROUND_EXPR:
4005 tree incremented, modify, value, compound;
4006 if (! lvalue_p (arg) && pedantic)
4007 pedwarn ("cast to non-reference type used as lvalue");
4008 arg = stabilize_reference (arg);
4009 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4012 value = save_expr (arg);
4013 incremented = build2 (((code == PREINCREMENT_EXPR
4014 || code == POSTINCREMENT_EXPR)
4015 ? PLUS_EXPR : MINUS_EXPR),
4016 argtype, value, inc);
4018 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4019 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4022 /* Eliminate warning about unused result of + or -. */
4023 TREE_NO_WARNING (compound) = 1;
4031 /* Complain about anything else that is not a true lvalue. */
4032 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4033 || code == POSTINCREMENT_EXPR)
4034 ? lv_increment : lv_decrement)))
4035 return error_mark_node;
4037 /* Forbid using -- on `bool'. */
4038 if (TREE_TYPE (arg) == boolean_type_node)
4040 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4042 error ("invalid use of %<--%> on bool variable %qD", arg);
4043 return error_mark_node;
4045 val = boolean_increment (code, arg);
4048 val = build2 (code, TREE_TYPE (arg), arg, inc);
4050 TREE_SIDE_EFFECTS (val) = 1;
4051 return cp_convert (result_type, val);
4055 /* Note that this operation never does default_conversion
4056 regardless of NOCONVERT. */
4058 argtype = lvalue_type (arg);
4060 if (TREE_CODE (arg) == OFFSET_REF)
4063 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4065 tree type = build_pointer_type (TREE_TYPE (argtype));
4066 arg = build1 (CONVERT_EXPR, type, arg);
4069 else if (pedantic && DECL_MAIN_P (arg))
4071 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4073 /* Let &* cancel out to simplify resulting code. */
4074 if (TREE_CODE (arg) == INDIRECT_REF)
4076 /* We don't need to have `current_class_ptr' wrapped in a
4077 NON_LVALUE_EXPR node. */
4078 if (arg == current_class_ref)
4079 return current_class_ptr;
4081 arg = TREE_OPERAND (arg, 0);
4082 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4084 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4085 arg = build1 (CONVERT_EXPR, type, arg);
4088 /* Don't let this be an lvalue. */
4093 /* Uninstantiated types are all functions. Taking the
4094 address of a function is a no-op, so just return the
4097 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4098 || !IDENTIFIER_OPNAME_P (arg));
4100 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4101 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4103 /* They're trying to take the address of a unique non-static
4104 member function. This is ill-formed (except in MS-land),
4105 but let's try to DTRT.
4106 Note: We only handle unique functions here because we don't
4107 want to complain if there's a static overload; non-unique
4108 cases will be handled by instantiate_type. But we need to
4109 handle this case here to allow casts on the resulting PMF.
4110 We could defer this in non-MS mode, but it's easier to give
4111 a useful error here. */
4113 /* Inside constant member functions, the `this' pointer
4114 contains an extra const qualifier. TYPE_MAIN_VARIANT
4115 is used here to remove this const from the diagnostics
4116 and the created OFFSET_REF. */
4117 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4118 tree name = DECL_NAME (get_first_fn (TREE_OPERAND (arg, 1)));
4120 if (! flag_ms_extensions)
4122 if (current_class_type
4123 && TREE_OPERAND (arg, 0) == current_class_ref)
4124 /* An expression like &memfn. */
4125 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4126 " or parenthesized non-static member function to form"
4127 " a pointer to member function. Say %<&%T::%D%>",
4130 pedwarn ("ISO C++ forbids taking the address of a bound member"
4131 " function to form a pointer to member function."
4135 arg = build_offset_ref (base, name, /*address_p=*/true);
4139 if (type_unknown_p (arg))
4140 return build1 (ADDR_EXPR, unknown_type_node, arg);
4142 /* Handle complex lvalues (when permitted)
4143 by reduction to simpler cases. */
4144 val = unary_complex_lvalue (code, arg);
4148 switch (TREE_CODE (arg))
4153 case FIX_TRUNC_EXPR:
4154 case FIX_FLOOR_EXPR:
4155 case FIX_ROUND_EXPR:
4157 if (! lvalue_p (arg) && pedantic)
4158 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4162 arg = OVL_CURRENT (arg);
4166 /* Turn a reference to a non-static data member into a
4167 pointer-to-member. */
4172 if (!PTRMEM_OK_P (arg))
4173 return build_unary_op (code, arg, 0);
4175 t = TREE_OPERAND (arg, 1);
4176 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4178 error ("cannot create pointer to reference member %qD", t);
4179 return error_mark_node;
4182 type = build_ptrmem_type (context_for_name_lookup (t),
4184 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4192 /* Anything not already handled and not a true memory reference
4194 if (TREE_CODE (argtype) != FUNCTION_TYPE
4195 && TREE_CODE (argtype) != METHOD_TYPE
4196 && TREE_CODE (arg) != OFFSET_REF
4197 /* Permit users to take the address of a compound-literal
4198 with sufficient simple elements. */
4199 && !(COMPOUND_LITERAL_P (arg) && TREE_STATIC (arg))
4200 && !lvalue_or_else (arg, lv_addressof))
4201 return error_mark_node;
4203 if (argtype != error_mark_node)
4204 argtype = build_pointer_type (argtype);
4206 /* In a template, we are processing a non-dependent expression
4207 so we can just form an ADDR_EXPR with the correct type. */
4208 if (processing_template_decl)
4210 val = build_address (arg);
4211 if (TREE_CODE (arg) == OFFSET_REF)
4212 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4216 /* If the user has taken the address of the compound literal,
4217 create a variable to contain the value of the literal and
4218 then return the address of that variable. */
4219 if (COMPOUND_LITERAL_P (arg))
4222 gcc_assert (TREE_STATIC (arg));
4223 var = create_temporary_var (TREE_TYPE (arg));
4224 TREE_STATIC (var) = 1;
4225 set_compound_literal_name (var);
4226 initialize_artificial_var (var, arg);
4227 arg = pushdecl (var);
4228 /* Since each compound literal is unique, pushdecl should
4229 never find a pre-existing variable with the same
4231 gcc_assert (arg == var);
4234 if (TREE_CODE (arg) != COMPONENT_REF)
4236 val = build_address (arg);
4237 if (TREE_CODE (arg) == OFFSET_REF)
4238 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4240 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4242 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4244 /* We can only get here with a single static member
4246 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4247 && DECL_STATIC_FUNCTION_P (fn));
4249 val = build_address (fn);
4250 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4251 /* Do not lose object's side effects. */
4252 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4253 TREE_OPERAND (arg, 0), val);
4255 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4257 error ("attempt to take address of bit-field structure member %qD",
4258 TREE_OPERAND (arg, 1));
4259 return error_mark_node;
4263 tree object = TREE_OPERAND (arg, 0);
4264 tree field = TREE_OPERAND (arg, 1);
4265 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4266 (TREE_TYPE (object), decl_type_context (field)));
4267 val = build_address (arg);
4270 if (TREE_CODE (argtype) == POINTER_TYPE
4271 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4273 build_ptrmemfunc_type (argtype);
4274 val = build_ptrmemfunc (argtype, val, 0,
4275 /*c_cast_p=*/false);
4287 argtype = TREE_TYPE (arg);
4288 return fold_if_not_in_template (build1 (code, argtype, arg));
4291 error ("%s", errstring);
4292 return error_mark_node;
4295 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4296 for certain kinds of expressions which are not really lvalues
4297 but which we can accept as lvalues.
4299 If ARG is not a kind of expression we can handle, return
4303 unary_complex_lvalue (enum tree_code code, tree arg)
4305 /* Inside a template, making these kinds of adjustments is
4306 pointless; we are only concerned with the type of the
4308 if (processing_template_decl)
4311 /* Handle (a, b) used as an "lvalue". */
4312 if (TREE_CODE (arg) == COMPOUND_EXPR)
4314 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4315 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4316 TREE_OPERAND (arg, 0), real_result);
4319 /* Handle (a ? b : c) used as an "lvalue". */
4320 if (TREE_CODE (arg) == COND_EXPR
4321 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4322 return rationalize_conditional_expr (code, arg);
4324 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4325 if (TREE_CODE (arg) == MODIFY_EXPR
4326 || TREE_CODE (arg) == PREINCREMENT_EXPR
4327 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4329 tree lvalue = TREE_OPERAND (arg, 0);
4330 if (TREE_SIDE_EFFECTS (lvalue))
4332 lvalue = stabilize_reference (lvalue);
4333 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4334 lvalue, TREE_OPERAND (arg, 1));
4336 return unary_complex_lvalue
4337 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4340 if (code != ADDR_EXPR)
4343 /* Handle (a = b) used as an "lvalue" for `&'. */
4344 if (TREE_CODE (arg) == MODIFY_EXPR
4345 || TREE_CODE (arg) == INIT_EXPR)
4347 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4348 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4350 TREE_NO_WARNING (arg) = 1;
4354 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4355 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4356 || TREE_CODE (arg) == OFFSET_REF)
4359 /* We permit compiler to make function calls returning
4360 objects of aggregate type look like lvalues. */
4364 if (TREE_CODE (targ) == SAVE_EXPR)
4365 targ = TREE_OPERAND (targ, 0);
4367 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4369 if (TREE_CODE (arg) == SAVE_EXPR)
4372 targ = build_cplus_new (TREE_TYPE (arg), arg);
4373 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4376 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4377 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4378 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4381 /* Don't let anything else be handled specially. */
4385 /* Mark EXP saying that we need to be able to take the
4386 address of it; it should not be allocated in a register.
4387 Value is true if successful.
4389 C++: we do not allow `current_class_ptr' to be addressable. */
4392 cxx_mark_addressable (tree exp)
4397 switch (TREE_CODE (x))
4404 x = TREE_OPERAND (x, 0);
4408 if (x == current_class_ptr)
4410 error ("cannot take the address of %<this%>, which is an rvalue expression");
4411 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4417 /* Caller should not be trying to mark initialized
4418 constant fields addressable. */
4419 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4420 || DECL_IN_AGGR_P (x) == 0
4422 || DECL_EXTERNAL (x));
4427 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4428 && !DECL_ARTIFICIAL (x))
4430 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4433 ("address of explicit register variable %qD requested", x);
4436 else if (extra_warnings)
4438 (0, "address requested for %qD, which is declared %<register%>", x);
4440 TREE_ADDRESSABLE (x) = 1;
4444 TREE_ADDRESSABLE (x) = 1;
4448 TREE_ADDRESSABLE (x) = 1;
4452 TREE_ADDRESSABLE (x) = 1;
4453 cxx_mark_addressable (TREE_OPERAND (x, 0));
4461 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4464 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4466 tree orig_ifexp = ifexp;
4467 tree orig_op1 = op1;
4468 tree orig_op2 = op2;
4471 if (processing_template_decl)
4473 /* The standard says that the expression is type-dependent if
4474 IFEXP is type-dependent, even though the eventual type of the
4475 expression doesn't dependent on IFEXP. */
4476 if (type_dependent_expression_p (ifexp)
4477 /* As a GNU extension, the middle operand may be omitted. */
4478 || (op1 && type_dependent_expression_p (op1))
4479 || type_dependent_expression_p (op2))
4480 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4481 ifexp = build_non_dependent_expr (ifexp);
4483 op1 = build_non_dependent_expr (op1);
4484 op2 = build_non_dependent_expr (op2);
4487 expr = build_conditional_expr (ifexp, op1, op2);
4488 if (processing_template_decl && expr != error_mark_node)
4489 return build_min_non_dep (COND_EXPR, expr,
4490 orig_ifexp, orig_op1, orig_op2);
4494 /* Given a list of expressions, return a compound expression
4495 that performs them all and returns the value of the last of them. */
4497 tree build_x_compound_expr_from_list (tree list, const char *msg)
4499 tree expr = TREE_VALUE (list);
4501 if (TREE_CHAIN (list))
4504 pedwarn ("%s expression list treated as compound expression", msg);
4506 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4507 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4513 /* Handle overloading of the ',' operator when needed. */
4516 build_x_compound_expr (tree op1, tree op2)
4519 tree orig_op1 = op1;
4520 tree orig_op2 = op2;
4522 if (processing_template_decl)
4524 if (type_dependent_expression_p (op1)
4525 || type_dependent_expression_p (op2))
4526 return build_min_nt (COMPOUND_EXPR, op1, op2);
4527 op1 = build_non_dependent_expr (op1);
4528 op2 = build_non_dependent_expr (op2);
4531 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4532 /*overloaded_p=*/NULL);
4534 result = build_compound_expr (op1, op2);
4536 if (processing_template_decl && result != error_mark_node)
4537 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4542 /* Build a compound expression. */
4545 build_compound_expr (tree lhs, tree rhs)
4547 lhs = convert_to_void (lhs, "left-hand operand of comma");
4549 if (lhs == error_mark_node || rhs == error_mark_node)
4550 return error_mark_node;
4552 if (TREE_CODE (rhs) == TARGET_EXPR)
4554 /* If the rhs is a TARGET_EXPR, then build the compound
4555 expression inside the target_expr's initializer. This
4556 helps the compiler to eliminate unnecessary temporaries. */
4557 tree init = TREE_OPERAND (rhs, 1);
4559 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4560 TREE_OPERAND (rhs, 1) = init;
4565 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4568 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4569 casts away constness. DIAG_FN gives the function to call if we
4570 need to issue a diagnostic; if it is NULL, no diagnostic will be
4571 issued. DESCRIPTION explains what operation is taking place. */
4574 check_for_casting_away_constness (tree src_type, tree dest_type,
4575 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4576 const char *description)
4578 if (diag_fn && casts_away_constness (src_type, dest_type))
4579 diag_fn ("%s from type %qT to type %qT casts away constness",
4580 description, src_type, dest_type);
4583 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4584 (another pointer-to-member type in the same hierarchy) and return
4585 the converted expression. If ALLOW_INVERSE_P is permitted, a
4586 pointer-to-derived may be converted to pointer-to-base; otherwise,
4587 only the other direction is permitted. If C_CAST_P is true, this
4588 conversion is taking place as part of a C-style cast. */
4591 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4594 if (TYPE_PTRMEM_P (type))
4598 if (TREE_CODE (expr) == PTRMEM_CST)
4599 expr = cplus_expand_constant (expr);
4600 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4601 TYPE_PTRMEM_CLASS_TYPE (type),
4604 if (!integer_zerop (delta))
4605 expr = cp_build_binary_op (PLUS_EXPR,
4606 build_nop (ptrdiff_type_node, expr),
4608 return build_nop (type, expr);
4611 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4612 allow_inverse_p, c_cast_p);
4615 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4616 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4617 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4620 ignore_overflows (tree expr, tree orig)
4622 if (TREE_CODE (expr) == INTEGER_CST
4623 && CONSTANT_CLASS_P (orig)
4624 && TREE_CODE (orig) != STRING_CST
4625 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4626 || TREE_CONSTANT_OVERFLOW (expr)
4627 != TREE_CONSTANT_OVERFLOW (orig)))
4629 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4630 /* Ensure constant sharing. */
4631 expr = build_int_cst_wide (TREE_TYPE (expr),
4632 TREE_INT_CST_LOW (expr),
4633 TREE_INT_CST_HIGH (expr));
4636 /* Avoid clobbering a shared constant. */
4637 expr = copy_node (expr);
4638 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4639 TREE_CONSTANT_OVERFLOW (expr)
4640 = TREE_CONSTANT_OVERFLOW (orig);
4646 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4647 this static_cast is being attempted as one of the possible casts
4648 allowed by a C-style cast. (In that case, accessibility of base
4649 classes is not considered, and it is OK to cast away
4650 constness.) Return the result of the cast. *VALID_P is set to
4651 indicate whether or not the cast was valid. */
4654 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4660 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4663 /* Assume the cast is valid. */
4666 intype = TREE_TYPE (expr);
4668 /* Determine what to do when casting away constness. */
4671 /* C-style casts are allowed to cast away constness. With
4672 WARN_CAST_QUAL, we still want to issue a warning. */
4673 diag_fn = warn_cast_qual ? warning0 : NULL;
4678 /* A static_cast may not cast away constness. */
4680 desc = "static_cast";
4683 /* [expr.static.cast]
4685 An lvalue of type "cv1 B", where B is a class type, can be cast
4686 to type "reference to cv2 D", where D is a class derived (clause
4687 _class.derived_) from B, if a valid standard conversion from
4688 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4689 same cv-qualification as, or greater cv-qualification than, cv1,
4690 and B is not a virtual base class of D. */
4691 /* We check this case before checking the validity of "TYPE t =
4692 EXPR;" below because for this case:
4695 struct D : public B { D(const B&); };
4697 void f() { static_cast<const D&>(b); }
4699 we want to avoid constructing a new D. The standard is not
4700 completely clear about this issue, but our interpretation is
4701 consistent with other compilers. */
4702 if (TREE_CODE (type) == REFERENCE_TYPE
4703 && CLASS_TYPE_P (TREE_TYPE (type))
4704 && CLASS_TYPE_P (intype)
4705 && real_lvalue_p (expr)
4706 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4707 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4708 build_pointer_type (TYPE_MAIN_VARIANT
4709 (TREE_TYPE (type))))
4711 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4715 /* There is a standard conversion from "D*" to "B*" even if "B"
4716 is ambiguous or inaccessible. If this is really a
4717 static_cast, then we check both for inaccessibility and
4718 ambiguity. However, if this is a static_cast being performed
4719 because the user wrote a C-style cast, then accessibility is
4721 base = lookup_base (TREE_TYPE (type), intype,
4722 c_cast_p ? ba_unique : ba_check,
4725 /* Convert from "B*" to "D*". This function will check that "B"
4726 is not a virtual base of "D". */
4727 expr = build_base_path (MINUS_EXPR, build_address (expr),
4728 base, /*nonnull=*/false);
4729 /* Convert the pointer to a reference -- but then remember that
4730 there are no expressions with reference type in C++. */
4731 return convert_from_reference (build_nop (type, expr));
4736 /* [expr.static.cast]
4738 An expression e can be explicitly converted to a type T using a
4739 static_cast of the form static_cast<T>(e) if the declaration T
4740 t(e);" is well-formed, for some invented temporary variable
4742 result = perform_direct_initialization_if_possible (type, expr,
4746 result = convert_from_reference (result);
4748 /* Ignore any integer overflow caused by the cast. */
4749 result = ignore_overflows (result, orig);
4751 /* [expr.static.cast]
4753 If T is a reference type, the result is an lvalue; otherwise,
4754 the result is an rvalue. */
4755 if (TREE_CODE (type) != REFERENCE_TYPE)
4756 result = rvalue (result);
4760 /* [expr.static.cast]
4762 Any expression can be explicitly converted to type cv void. */
4763 if (TREE_CODE (type) == VOID_TYPE)
4764 return convert_to_void (expr, /*implicit=*/NULL);
4766 /* [expr.static.cast]
4768 The inverse of any standard conversion sequence (clause _conv_),
4769 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4770 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4771 (_conv.bool_) conversions, can be performed explicitly using
4772 static_cast subject to the restriction that the explicit
4773 conversion does not cast away constness (_expr.const.cast_), and
4774 the following additional rules for specific cases: */
4775 /* For reference, the conversions not excluded are: integral
4776 promotions, floating point promotion, integral conversions,
4777 floating point conversions, floating-integral conversions,
4778 pointer conversions, and pointer to member conversions. */
4781 A value of integral _or enumeration_ type can be explicitly
4782 converted to an enumeration type. */
4783 /* The effect of all that is that any conversion between any two
4784 types which are integral, floating, or enumeration types can be
4786 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4787 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4789 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4791 /* Ignore any integer overflow caused by the cast. */
4792 expr = ignore_overflows (expr, orig);
4796 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4797 && CLASS_TYPE_P (TREE_TYPE (type))
4798 && CLASS_TYPE_P (TREE_TYPE (intype))
4799 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4800 (TREE_TYPE (intype))),
4801 build_pointer_type (TYPE_MAIN_VARIANT
4802 (TREE_TYPE (type)))))
4807 check_for_casting_away_constness (intype, type, diag_fn, desc);
4808 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4809 c_cast_p ? ba_unique : ba_check,
4811 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4814 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4815 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
4822 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
4823 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
4825 if (TYPE_PTRMEM_P (type))
4827 t1 = (build_ptrmem_type
4829 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
4830 t2 = (build_ptrmem_type
4832 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
4839 if (can_convert (t1, t2))
4842 check_for_casting_away_constness (intype, type, diag_fn,
4844 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
4849 /* [expr.static.cast]
4851 An rvalue of type "pointer to cv void" can be explicitly
4852 converted to a pointer to object type. A value of type pointer
4853 to object converted to "pointer to cv void" and back to the
4854 original pointer type will have its original value. */
4855 if (TREE_CODE (intype) == POINTER_TYPE
4856 && VOID_TYPE_P (TREE_TYPE (intype))
4857 && TYPE_PTROB_P (type))
4860 check_for_casting_away_constness (intype, type, diag_fn, desc);
4861 return build_nop (type, expr);
4865 return error_mark_node;
4868 /* Return an expression representing static_cast<TYPE>(EXPR). */
4871 build_static_cast (tree type, tree expr)
4876 if (type == error_mark_node || expr == error_mark_node)
4877 return error_mark_node;
4879 if (processing_template_decl)
4881 expr = build_min (STATIC_CAST_EXPR, type, expr);
4882 /* We don't know if it will or will not have side effects. */
4883 TREE_SIDE_EFFECTS (expr) = 1;
4884 return convert_from_reference (expr);
4887 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
4888 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
4889 if (TREE_CODE (type) != REFERENCE_TYPE
4890 && TREE_CODE (expr) == NOP_EXPR
4891 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
4892 expr = TREE_OPERAND (expr, 0);
4894 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
4898 error ("invalid static_cast from type %qT to type %qT",
4899 TREE_TYPE (expr), type);
4900 return error_mark_node;
4903 /* EXPR is an expression with member function or pointer-to-member
4904 function type. TYPE is a pointer type. Converting EXPR to TYPE is
4905 not permitted by ISO C++, but we accept it in some modes. If we
4906 are not in one of those modes, issue a diagnostic. Return the
4907 converted expression. */
4910 convert_member_func_to_ptr (tree type, tree expr)
4915 intype = TREE_TYPE (expr);
4916 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
4917 || TREE_CODE (intype) == METHOD_TYPE);
4919 if (pedantic || warn_pmf2ptr)
4920 pedwarn ("converting from %qT to %qT", intype, type);
4922 if (TREE_CODE (intype) == METHOD_TYPE)
4923 expr = build_addr_func (expr);
4924 else if (TREE_CODE (expr) == PTRMEM_CST)
4925 expr = build_address (PTRMEM_CST_MEMBER (expr));
4928 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
4929 decl = build_address (decl);
4930 expr = get_member_function_from_ptrfunc (&decl, expr);
4933 return build_nop (type, expr);
4936 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
4937 If C_CAST_P is true, this reinterpret cast is being done as part of
4938 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
4939 indicate whether or not reinterpret_cast was valid. */
4942 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
4947 /* Assume the cast is invalid. */
4951 if (type == error_mark_node || error_operand_p (expr))
4952 return error_mark_node;
4954 intype = TREE_TYPE (expr);
4956 /* [expr.reinterpret.cast]
4957 An lvalue expression of type T1 can be cast to the type
4958 "reference to T2" if an expression of type "pointer to T1" can be
4959 explicitly converted to the type "pointer to T2" using a
4960 reinterpret_cast. */
4961 if (TREE_CODE (type) == REFERENCE_TYPE)
4963 if (! real_lvalue_p (expr))
4965 error ("invalid cast of an rvalue expression of type "
4968 return error_mark_node;
4971 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
4972 "B" are related class types; the reinterpret_cast does not
4973 adjust the pointer. */
4974 if (TYPE_PTR_P (intype)
4975 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
4976 COMPARE_BASE | COMPARE_DERIVED)))
4977 warning (0, "casting %qT to %qT does not dereference pointer",
4980 expr = build_unary_op (ADDR_EXPR, expr, 0);
4981 if (expr != error_mark_node)
4982 expr = build_reinterpret_cast_1
4983 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
4985 if (expr != error_mark_node)
4986 expr = build_indirect_ref (expr, 0);
4990 /* As a G++ extension, we consider conversions from member
4991 functions, and pointers to member functions to
4992 pointer-to-function and pointer-to-void types. If
4993 -Wno-pmf-conversions has not been specified,
4994 convert_member_func_to_ptr will issue an error message. */
4995 if ((TYPE_PTRMEMFUNC_P (intype)
4996 || TREE_CODE (intype) == METHOD_TYPE)
4997 && TYPE_PTR_P (type)
4998 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
4999 || VOID_TYPE_P (TREE_TYPE (type))))
5000 return convert_member_func_to_ptr (type, expr);
5002 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5003 array-to-pointer, and function-to-pointer conversions are
5005 expr = decay_conversion (expr);
5007 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5008 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5009 if (TREE_CODE (expr) == NOP_EXPR
5010 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5011 expr = TREE_OPERAND (expr, 0);
5013 if (error_operand_p (expr))
5014 return error_mark_node;
5016 intype = TREE_TYPE (expr);
5018 /* [expr.reinterpret.cast]
5019 A pointer can be converted to any integral type large enough to
5021 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5023 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5024 pedwarn ("cast from %qT to %qT loses precision",
5027 /* [expr.reinterpret.cast]
5028 A value of integral or enumeration type can be explicitly
5029 converted to a pointer. */
5030 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5033 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5034 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5035 return fold_if_not_in_template (build_nop (type, expr));
5036 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5037 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5042 check_for_casting_away_constness (intype, type, error,
5043 "reinterpret_cast");
5044 /* Warn about possible alignment problems. */
5045 if (STRICT_ALIGNMENT && warn_cast_align
5046 && !VOID_TYPE_P (type)
5047 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5048 && COMPLETE_TYPE_P (TREE_TYPE (type))
5049 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5050 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5051 warning (0, "cast from %qT to %qT increases required alignment of "
5055 /* We need to strip nops here, because the frontend likes to
5056 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5058 strict_aliasing_warning (intype, type, sexpr);
5060 return fold_if_not_in_template (build_nop (type, expr));
5062 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5063 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5066 /* Only issue a warning, as we have always supported this
5067 where possible, and it is necessary in some cases. DR 195
5068 addresses this issue, but as of 2004/10/26 is still in
5070 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5071 return fold_if_not_in_template (build_nop (type, expr));
5073 else if (TREE_CODE (type) == VECTOR_TYPE)
5074 return fold_if_not_in_template (convert_to_vector (type, expr));
5075 else if (TREE_CODE (intype) == VECTOR_TYPE)
5076 return fold_if_not_in_template (convert_to_integer (type, expr));
5081 error ("invalid cast from type %qT to type %qT", intype, type);
5082 return error_mark_node;
5085 return cp_convert (type, expr);
5089 build_reinterpret_cast (tree type, tree expr)
5091 if (type == error_mark_node || expr == error_mark_node)
5092 return error_mark_node;
5094 if (processing_template_decl)
5096 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5098 if (!TREE_SIDE_EFFECTS (t)
5099 && type_dependent_expression_p (expr))
5100 /* There might turn out to be side effects inside expr. */
5101 TREE_SIDE_EFFECTS (t) = 1;
5102 return convert_from_reference (t);
5105 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5109 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5110 return an appropriate expression. Otherwise, return
5111 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5112 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5113 performing a C-style cast, its value upon return will indicate
5114 whether or not the conversion succeeded. */
5117 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5121 tree reference_type;
5123 /* Callers are responsible for handling error_mark_node as a
5124 destination type. */
5125 gcc_assert (dst_type != error_mark_node);
5126 /* In a template, callers should be building syntactic
5127 representations of casts, not using this machinery. */
5128 gcc_assert (!processing_template_decl);
5130 /* Assume the conversion is invalid. */
5134 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5137 error ("invalid use of const_cast with type %qT, "
5138 "which is not a pointer, "
5139 "reference, nor a pointer-to-data-member type", dst_type);
5140 return error_mark_node;
5143 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5146 error ("invalid use of const_cast with type %qT, which is a pointer "
5147 "or reference to a function type", dst_type);
5148 return error_mark_node;
5151 src_type = TREE_TYPE (expr);
5152 /* Expressions do not really have reference types. */
5153 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5154 src_type = TREE_TYPE (src_type);
5156 /* [expr.const.cast]
5158 An lvalue of type T1 can be explicitly converted to an lvalue of
5159 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5160 types) if a pointer to T1 can be explicitly converted to the type
5161 pointer to T2 using a const_cast. */
5162 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5164 reference_type = dst_type;
5165 if (! real_lvalue_p (expr))
5168 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5169 src_type, dst_type);
5170 return error_mark_node;
5172 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5173 src_type = build_pointer_type (src_type);
5177 reference_type = NULL_TREE;
5178 /* If the destination type is not a reference type, the
5179 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5180 conversions are performed. */
5181 src_type = type_decays_to (src_type);
5182 if (src_type == error_mark_node)
5183 return error_mark_node;
5186 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5187 && comp_ptr_ttypes_const (dst_type, src_type))
5192 /* This cast is actually a C-style cast. Issue a warning if
5193 the user is making a potentially unsafe cast. */
5195 check_for_casting_away_constness (src_type, dst_type,
5201 expr = build_unary_op (ADDR_EXPR, expr, 0);
5202 expr = build_nop (reference_type, expr);
5203 return convert_from_reference (expr);
5207 expr = decay_conversion (expr);
5208 /* build_c_cast puts on a NOP_EXPR to make the result not an
5209 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5210 non-lvalue context. */
5211 if (TREE_CODE (expr) == NOP_EXPR
5212 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5213 expr = TREE_OPERAND (expr, 0);
5214 return build_nop (dst_type, expr);
5219 error ("invalid const_cast from type %qT to type %qT",
5220 src_type, dst_type);
5221 return error_mark_node;
5225 build_const_cast (tree type, tree expr)
5227 if (type == error_mark_node || error_operand_p (expr))
5228 return error_mark_node;
5230 if (processing_template_decl)
5232 tree t = build_min (CONST_CAST_EXPR, type, expr);
5234 if (!TREE_SIDE_EFFECTS (t)
5235 && type_dependent_expression_p (expr))
5236 /* There might turn out to be side effects inside expr. */
5237 TREE_SIDE_EFFECTS (t) = 1;
5238 return convert_from_reference (t);
5241 return build_const_cast_1 (type, expr, /*complain=*/true,
5245 /* Build an expression representing an explicit C-style cast to type
5246 TYPE of expression EXPR. */
5249 build_c_cast (tree type, tree expr)
5255 if (type == error_mark_node || error_operand_p (expr))
5256 return error_mark_node;
5258 if (processing_template_decl)
5260 tree t = build_min (CAST_EXPR, type,
5261 tree_cons (NULL_TREE, value, NULL_TREE));
5262 /* We don't know if it will or will not have side effects. */
5263 TREE_SIDE_EFFECTS (t) = 1;
5264 return convert_from_reference (t);
5267 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5268 'Class') should always be retained, because this information aids
5269 in method lookup. */
5270 if (objc_is_object_ptr (type)
5271 && objc_is_object_ptr (TREE_TYPE (expr)))
5272 return build_nop (type, expr);
5274 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5275 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5276 if (TREE_CODE (type) != REFERENCE_TYPE
5277 && TREE_CODE (value) == NOP_EXPR
5278 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5279 value = TREE_OPERAND (value, 0);
5281 if (TREE_CODE (type) == ARRAY_TYPE)
5283 /* Allow casting from T1* to T2[] because Cfront allows it.
5284 NIHCL uses it. It is not valid ISO C++ however. */
5285 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5287 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5288 type = build_pointer_type (TREE_TYPE (type));
5292 error ("ISO C++ forbids casting to an array type %qT", type);
5293 return error_mark_node;
5297 if (TREE_CODE (type) == FUNCTION_TYPE
5298 || TREE_CODE (type) == METHOD_TYPE)
5300 error ("invalid cast to function type %qT", type);
5301 return error_mark_node;
5304 /* A C-style cast can be a const_cast. */
5305 result = build_const_cast_1 (type, value, /*complain=*/false,
5310 /* Or a static cast. */
5311 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5313 /* Or a reinterpret_cast. */
5315 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5317 /* The static_cast or reinterpret_cast may be followed by a
5320 /* A valid cast may result in errors if, for example, a
5321 conversion to am ambiguous base class is required. */
5322 && !error_operand_p (result))
5326 /* Non-class rvalues always have cv-unqualified type. */
5327 if (!CLASS_TYPE_P (type))
5328 type = TYPE_MAIN_VARIANT (type);
5329 result_type = TREE_TYPE (result);
5330 if (!CLASS_TYPE_P (result_type))
5331 result_type = TYPE_MAIN_VARIANT (result_type);
5332 /* If the type of RESULT does not match TYPE, perform a
5333 const_cast to make it match. If the static_cast or
5334 reinterpret_cast succeeded, we will differ by at most
5335 cv-qualification, so the follow-on const_cast is guaranteed
5337 if (!same_type_p (non_reference (type), non_reference (result_type)))
5339 result = build_const_cast_1 (type, result, false, &valid_p);
5340 gcc_assert (valid_p);
5345 return error_mark_node;
5348 /* Build an assignment expression of lvalue LHS from value RHS.
5349 MODIFYCODE is the code for a binary operator that we use
5350 to combine the old value of LHS with RHS to get the new value.
5351 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5353 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5356 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5360 tree lhstype = TREE_TYPE (lhs);
5361 tree olhstype = lhstype;
5362 tree olhs = NULL_TREE;
5363 bool plain_assign = (modifycode == NOP_EXPR);
5365 /* Avoid duplicate error messages from operands that had errors. */
5366 if (lhs == error_mark_node || rhs == error_mark_node)
5367 return error_mark_node;
5369 /* Handle control structure constructs used as "lvalues". */
5370 switch (TREE_CODE (lhs))
5372 /* Handle --foo = 5; as these are valid constructs in C++. */
5373 case PREDECREMENT_EXPR:
5374 case PREINCREMENT_EXPR:
5375 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5376 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5377 stabilize_reference (TREE_OPERAND (lhs, 0)),
5378 TREE_OPERAND (lhs, 1));
5379 return build2 (COMPOUND_EXPR, lhstype,
5381 build_modify_expr (TREE_OPERAND (lhs, 0),
5384 /* Handle (a, b) used as an "lvalue". */
5386 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5388 if (newrhs == error_mark_node)
5389 return error_mark_node;
5390 return build2 (COMPOUND_EXPR, lhstype,
5391 TREE_OPERAND (lhs, 0), newrhs);
5394 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5395 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5396 stabilize_reference (TREE_OPERAND (lhs, 0)),
5397 TREE_OPERAND (lhs, 1));
5398 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5399 if (newrhs == error_mark_node)
5400 return error_mark_node;
5401 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5405 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5406 when neither operand has side-effects. */
5407 if (!lvalue_or_else (lhs, lv_assign))
5408 return error_mark_node;
5410 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5411 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5413 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5414 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5416 TREE_OPERAND (lhs, 0),
5417 TREE_OPERAND (lhs, 1)),
5418 TREE_OPERAND (lhs, 0),
5419 TREE_OPERAND (lhs, 1));
5422 /* Handle (a ? b : c) used as an "lvalue". */
5425 /* Produce (a ? (b = rhs) : (c = rhs))
5426 except that the RHS goes through a save-expr
5427 so the code to compute it is only emitted once. */
5429 tree preeval = NULL_TREE;
5431 rhs = stabilize_expr (rhs, &preeval);
5433 /* Check this here to avoid odd errors when trying to convert
5434 a throw to the type of the COND_EXPR. */
5435 if (!lvalue_or_else (lhs, lv_assign))
5436 return error_mark_node;
5438 cond = build_conditional_expr
5439 (TREE_OPERAND (lhs, 0),
5440 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5441 TREE_OPERAND (lhs, 1)),
5443 build_modify_expr (cp_convert (TREE_TYPE (lhs),
5444 TREE_OPERAND (lhs, 2)),
5447 if (cond == error_mark_node)
5449 /* Make sure the code to compute the rhs comes out
5450 before the split. */
5452 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5460 if (modifycode == INIT_EXPR)
5462 if (TREE_CODE (rhs) == CONSTRUCTOR)
5464 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5465 /* Call convert to generate an error; see PR 11063. */
5466 rhs = convert (lhstype, rhs);
5467 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5468 TREE_SIDE_EFFECTS (result) = 1;
5471 else if (! IS_AGGR_TYPE (lhstype))
5472 /* Do the default thing. */;
5475 result = build_special_member_call (lhs, complete_ctor_identifier,
5476 build_tree_list (NULL_TREE, rhs),
5477 lhstype, LOOKUP_NORMAL);
5478 if (result == NULL_TREE)
5479 return error_mark_node;
5485 lhs = require_complete_type (lhs);
5486 if (lhs == error_mark_node)
5487 return error_mark_node;
5489 if (modifycode == NOP_EXPR)
5491 /* `operator=' is not an inheritable operator. */
5492 if (! IS_AGGR_TYPE (lhstype))
5493 /* Do the default thing. */;
5496 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5497 lhs, rhs, make_node (NOP_EXPR),
5498 /*overloaded_p=*/NULL);
5499 if (result == NULL_TREE)
5500 return error_mark_node;
5507 /* A binary op has been requested. Combine the old LHS
5508 value with the RHS producing the value we should actually
5509 store into the LHS. */
5511 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5512 lhs = stabilize_reference (lhs);
5513 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5514 if (newrhs == error_mark_node)
5516 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5517 TREE_TYPE (lhs), TREE_TYPE (rhs));
5518 return error_mark_node;
5521 /* Now it looks like a plain assignment. */
5522 modifycode = NOP_EXPR;
5524 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5525 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5528 /* The left-hand side must be an lvalue. */
5529 if (!lvalue_or_else (lhs, lv_assign))
5530 return error_mark_node;
5532 /* Warn about modifying something that is `const'. Don't warn if
5533 this is initialization. */
5534 if (modifycode != INIT_EXPR
5535 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5536 /* Functions are not modifiable, even though they are
5538 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5539 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5540 /* If it's an aggregate and any field is const, then it is
5541 effectively const. */
5542 || (CLASS_TYPE_P (lhstype)
5543 && C_TYPE_FIELDS_READONLY (lhstype))))
5544 readonly_error (lhs, "assignment", 0);
5546 /* If storing into a structure or union member, it has probably been
5547 given type `int'. Compute the type that would go with the actual
5548 amount of storage the member occupies. */
5550 if (TREE_CODE (lhs) == COMPONENT_REF
5551 && (TREE_CODE (lhstype) == INTEGER_TYPE
5552 || TREE_CODE (lhstype) == REAL_TYPE
5553 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5555 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5557 /* If storing in a field that is in actuality a short or narrower
5558 than one, we must store in the field in its actual type. */
5560 if (lhstype != TREE_TYPE (lhs))
5562 /* Avoid warnings converting integral types back into enums for
5564 if (TREE_CODE (lhstype) == INTEGER_TYPE
5565 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5567 if (TREE_SIDE_EFFECTS (lhs))
5568 lhs = stabilize_reference (lhs);
5571 lhs = copy_node (lhs);
5572 TREE_TYPE (lhs) = lhstype;
5576 /* Convert new value to destination type. */
5578 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5582 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5583 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5585 error ("incompatible types in assignment of %qT to %qT",
5586 TREE_TYPE (rhs), lhstype);
5587 return error_mark_node;
5590 /* Allow array assignment in compiler-generated code. */
5591 if (! DECL_ARTIFICIAL (current_function_decl))
5592 pedwarn ("ISO C++ forbids assignment of arrays");
5594 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5595 ? 1 + (modifycode != INIT_EXPR): 0;
5596 return build_vec_init (lhs, NULL_TREE, newrhs,
5597 /*explicit_default_init_p=*/false,
5601 if (modifycode == INIT_EXPR)
5602 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5603 "initialization", NULL_TREE, 0);
5606 /* Avoid warnings on enum bit fields. */
5607 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5608 && TREE_CODE (lhstype) == INTEGER_TYPE)
5610 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5612 newrhs = convert_force (lhstype, newrhs, 0);
5615 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5617 if (TREE_CODE (newrhs) == CALL_EXPR
5618 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5619 newrhs = build_cplus_new (lhstype, newrhs);
5621 /* Can't initialize directly from a TARGET_EXPR, since that would
5622 cause the lhs to be constructed twice, and possibly result in
5623 accidental self-initialization. So we force the TARGET_EXPR to be
5624 expanded without a target. */
5625 if (TREE_CODE (newrhs) == TARGET_EXPR)
5626 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5627 TREE_OPERAND (newrhs, 0));
5630 if (newrhs == error_mark_node)
5631 return error_mark_node;
5633 if (TREE_CODE (lhs) == COMPONENT_REF)
5634 newrhs = adjust_bitfield_initializer (TREE_OPERAND (lhs, 1),
5637 if (c_dialect_objc () && flag_objc_gc)
5639 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5645 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5646 lhstype, lhs, newrhs);
5648 TREE_SIDE_EFFECTS (result) = 1;
5650 TREE_NO_WARNING (result) = 1;
5652 /* If we got the LHS in a different type for storing in,
5653 convert the result back to the nominal type of LHS
5654 so that the value we return always has the same type
5655 as the LHS argument. */
5657 if (olhstype == TREE_TYPE (result))
5661 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5662 TREE_NO_WARNING (result) = 1;
5665 return convert_for_assignment (olhstype, result, "assignment",
5670 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5672 if (processing_template_decl)
5673 return build_min_nt (MODOP_EXPR, lhs,
5674 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5676 if (modifycode != NOP_EXPR)
5678 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5679 make_node (modifycode),
5680 /*overloaded_p=*/NULL);
5683 TREE_NO_WARNING (rval) = 1;
5687 return build_modify_expr (lhs, modifycode, rhs);
5691 /* Get difference in deltas for different pointer to member function
5692 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5693 the conversion is invalid, the constant is zero. If
5694 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5695 If C_CAST_P is true this conversion is taking place as part of a
5698 Note that the naming of FROM and TO is kind of backwards; the return
5699 value is what we add to a TO in order to get a FROM. They are named
5700 this way because we call this function to find out how to convert from
5701 a pointer to member of FROM to a pointer to member of TO. */
5704 get_delta_difference (tree from, tree to,
5705 bool allow_inverse_p,
5712 /* Assume no conversion is required. */
5713 result = integer_zero_node;
5714 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5715 if (kind == bk_inaccessible || kind == bk_ambig)
5716 error (" in pointer to member function conversion");
5719 if (kind != bk_via_virtual)
5720 result = BINFO_OFFSET (binfo);
5723 tree virt_binfo = binfo_from_vbase (binfo);
5725 /* This is a reinterpret cast, we choose to do nothing. */
5726 if (allow_inverse_p)
5727 warning (0, "pointer to member cast via virtual base %qT",
5728 BINFO_TYPE (virt_binfo));
5730 error ("pointer to member conversion via virtual base %qT",
5731 BINFO_TYPE (virt_binfo));
5734 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5735 /* Pointer to member of incomplete class is permitted*/;
5736 else if (!allow_inverse_p)
5738 error_not_base_type (from, to);
5739 error (" in pointer to member conversion");
5743 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5746 if (kind != bk_via_virtual)
5747 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5750 /* This is a reinterpret cast, we choose to do nothing. */
5751 tree virt_binfo = binfo_from_vbase (binfo);
5753 warning (0, "pointer to member cast via virtual base %qT",
5754 BINFO_TYPE (virt_binfo));
5759 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5763 /* Return a constructor for the pointer-to-member-function TYPE using
5764 the other components as specified. */
5767 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5772 VEC(constructor_elt, gc) *v;
5774 /* Pull the FIELD_DECLs out of the type. */
5775 pfn_field = TYPE_FIELDS (type);
5776 delta_field = TREE_CHAIN (pfn_field);
5778 /* Make sure DELTA has the type we want. */
5779 delta = convert_and_check (delta_type_node, delta);
5781 /* Finish creating the initializer. */
5782 v = VEC_alloc(constructor_elt, gc, 2);
5783 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
5784 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
5785 u = build_constructor (type, v);
5786 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5787 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5788 TREE_STATIC (u) = (TREE_CONSTANT (u)
5789 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5791 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5796 /* Build a constructor for a pointer to member function. It can be
5797 used to initialize global variables, local variable, or used
5798 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5801 If FORCE is nonzero, then force this conversion, even if
5802 we would rather not do it. Usually set when using an explicit
5803 cast. A C-style cast is being processed iff C_CAST_P is true.
5805 Return error_mark_node, if something goes wrong. */
5808 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
5814 if (error_operand_p (pfn))
5815 return error_mark_node;
5817 pfn_type = TREE_TYPE (pfn);
5818 to_type = build_ptrmemfunc_type (type);
5820 /* Handle multiple conversions of pointer to member functions. */
5821 if (TYPE_PTRMEMFUNC_P (pfn_type))
5823 tree delta = NULL_TREE;
5824 tree npfn = NULL_TREE;
5828 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
5829 error ("invalid conversion to type %qT from type %qT",
5832 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
5833 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
5837 /* We don't have to do any conversion to convert a
5838 pointer-to-member to its own type. But, we don't want to
5839 just return a PTRMEM_CST if there's an explicit cast; that
5840 cast should make the expression an invalid template argument. */
5841 if (TREE_CODE (pfn) != PTRMEM_CST)
5843 if (same_type_p (to_type, pfn_type))
5845 else if (integer_zerop (n))
5846 return build_reinterpret_cast (to_type, pfn);
5849 if (TREE_SIDE_EFFECTS (pfn))
5850 pfn = save_expr (pfn);
5852 /* Obtain the function pointer and the current DELTA. */
5853 if (TREE_CODE (pfn) == PTRMEM_CST)
5854 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
5857 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
5858 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
5861 /* Just adjust the DELTA field. */
5862 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5863 (TREE_TYPE (delta), ptrdiff_type_node));
5864 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
5865 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
5866 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
5867 return build_ptrmemfunc1 (to_type, delta, npfn);
5870 /* Handle null pointer to member function conversions. */
5871 if (integer_zerop (pfn))
5873 pfn = build_c_cast (type, integer_zero_node);
5874 return build_ptrmemfunc1 (to_type,
5879 if (type_unknown_p (pfn))
5880 return instantiate_type (type, pfn, tf_error | tf_warning);
5882 fn = TREE_OPERAND (pfn, 0);
5883 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
5884 /* In a template, we will have preserved the
5886 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
5887 return make_ptrmem_cst (to_type, fn);
5890 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
5893 ??? There is no consistency as to the types returned for the above
5894 values. Some code acts as if it were a sizetype and some as if it were
5895 integer_type_node. */
5898 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
5900 tree type = TREE_TYPE (cst);
5901 tree fn = PTRMEM_CST_MEMBER (cst);
5902 tree ptr_class, fn_class;
5904 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5906 /* The class that the function belongs to. */
5907 fn_class = DECL_CONTEXT (fn);
5909 /* The class that we're creating a pointer to member of. */
5910 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
5912 /* First, calculate the adjustment to the function's class. */
5913 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
5916 if (!DECL_VIRTUAL_P (fn))
5917 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
5920 /* If we're dealing with a virtual function, we have to adjust 'this'
5921 again, to point to the base which provides the vtable entry for
5922 fn; the call will do the opposite adjustment. */
5923 tree orig_class = DECL_CONTEXT (fn);
5924 tree binfo = binfo_or_else (orig_class, fn_class);
5925 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5926 *delta, BINFO_OFFSET (binfo));
5927 *delta = fold_if_not_in_template (*delta);
5929 /* We set PFN to the vtable offset at which the function can be
5930 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
5931 case delta is shifted left, and then incremented). */
5932 *pfn = DECL_VINDEX (fn);
5933 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
5934 TYPE_SIZE_UNIT (vtable_entry_type));
5935 *pfn = fold_if_not_in_template (*pfn);
5937 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
5939 case ptrmemfunc_vbit_in_pfn:
5940 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
5942 *pfn = fold_if_not_in_template (*pfn);
5945 case ptrmemfunc_vbit_in_delta:
5946 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
5947 *delta, integer_one_node);
5948 *delta = fold_if_not_in_template (*delta);
5949 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
5950 *delta, integer_one_node);
5951 *delta = fold_if_not_in_template (*delta);
5958 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
5959 *pfn = fold_if_not_in_template (*pfn);
5963 /* Return an expression for PFN from the pointer-to-member function
5967 pfn_from_ptrmemfunc (tree t)
5969 if (TREE_CODE (t) == PTRMEM_CST)
5974 expand_ptrmemfunc_cst (t, &delta, &pfn);
5979 return build_ptrmemfunc_access_expr (t, pfn_identifier);
5982 /* Convert value RHS to type TYPE as preparation for an assignment to
5983 an lvalue of type TYPE. ERRTYPE is a string to use in error
5984 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
5985 are doing the conversion in order to pass the PARMNUMth argument of
5989 convert_for_assignment (tree type, tree rhs,
5990 const char *errtype, tree fndecl, int parmnum)
5993 enum tree_code coder;
5995 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
5996 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
5997 rhs = TREE_OPERAND (rhs, 0);
5999 rhstype = TREE_TYPE (rhs);
6000 coder = TREE_CODE (rhstype);
6002 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6003 && vector_types_convertible_p (type, rhstype))
6004 return convert (type, rhs);
6006 if (rhs == error_mark_node || rhstype == error_mark_node)
6007 return error_mark_node;
6008 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6009 return error_mark_node;
6011 /* The RHS of an assignment cannot have void type. */
6012 if (coder == VOID_TYPE)
6014 error ("void value not ignored as it ought to be");
6015 return error_mark_node;
6018 /* Simplify the RHS if possible. */
6019 if (TREE_CODE (rhs) == CONST_DECL)
6020 rhs = DECL_INITIAL (rhs);
6022 if (c_dialect_objc ())
6025 tree rname = fndecl;
6027 if (!strcmp (errtype, "assignment"))
6029 else if (!strcmp (errtype, "initialization"))
6033 tree selector = objc_message_selector ();
6037 if (selector && parmno > 1)
6044 if (objc_compare_types (type, rhstype, parmno, rname))
6045 return convert (type, rhs);
6050 The expression is implicitly converted (clause _conv_) to the
6051 cv-unqualified type of the left operand.
6053 We allow bad conversions here because by the time we get to this point
6054 we are committed to doing the conversion. If we end up doing a bad
6055 conversion, convert_like will complain. */
6056 if (!can_convert_arg_bad (type, rhstype, rhs))
6058 /* When -Wno-pmf-conversions is use, we just silently allow
6059 conversions from pointers-to-members to plain pointers. If
6060 the conversion doesn't work, cp_convert will complain. */
6062 && TYPE_PTR_P (type)
6063 && TYPE_PTRMEMFUNC_P (rhstype))
6064 rhs = cp_convert (strip_top_quals (type), rhs);
6067 /* If the right-hand side has unknown type, then it is an
6068 overloaded function. Call instantiate_type to get error
6070 if (rhstype == unknown_type_node)
6071 instantiate_type (type, rhs, tf_error | tf_warning);
6073 error ("cannot convert %qT to %qT for argument %qP to %qD",
6074 rhstype, type, parmnum, fndecl);
6076 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6077 return error_mark_node;
6080 if (warn_missing_format_attribute)
6082 const enum tree_code codel = TREE_CODE (type);
6083 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6085 && check_missing_format_attribute (type, rhstype))
6086 warning (OPT_Wmissing_format_attribute,
6087 "%s might be a candidate for a format attribute",
6091 return perform_implicit_conversion (strip_top_quals (type), rhs);
6094 /* Convert RHS to be of type TYPE.
6095 If EXP is nonzero, it is the target of the initialization.
6096 ERRTYPE is a string to use in error messages.
6098 Two major differences between the behavior of
6099 `convert_for_assignment' and `convert_for_initialization'
6100 are that references are bashed in the former, while
6101 copied in the latter, and aggregates are assigned in
6102 the former (operator=) while initialized in the
6105 If using constructor make sure no conversion operator exists, if one does
6106 exist, an ambiguity exists.
6108 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6111 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6112 const char *errtype, tree fndecl, int parmnum)
6114 enum tree_code codel = TREE_CODE (type);
6116 enum tree_code coder;
6118 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6119 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6120 if (TREE_CODE (rhs) == NOP_EXPR
6121 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6122 && codel != REFERENCE_TYPE)
6123 rhs = TREE_OPERAND (rhs, 0);
6125 if (rhs == error_mark_node
6126 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6127 return error_mark_node;
6129 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6130 && TREE_CODE (type) != ARRAY_TYPE
6131 && (TREE_CODE (type) != REFERENCE_TYPE
6132 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6133 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6134 && (TREE_CODE (type) != REFERENCE_TYPE
6135 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6136 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6137 rhs = decay_conversion (rhs);
6139 rhstype = TREE_TYPE (rhs);
6140 coder = TREE_CODE (rhstype);
6142 if (coder == ERROR_MARK)
6143 return error_mark_node;
6145 /* We accept references to incomplete types, so we can
6146 return here before checking if RHS is of complete type. */
6148 if (codel == REFERENCE_TYPE)
6150 /* This should eventually happen in convert_arguments. */
6151 int savew = 0, savee = 0;
6154 savew = warningcount, savee = errorcount;
6155 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6159 if (warningcount > savew)
6160 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6161 else if (errorcount > savee)
6162 error ("in passing argument %P of %q+D", parmnum, fndecl);
6168 exp = require_complete_type (exp);
6169 if (exp == error_mark_node)
6170 return error_mark_node;
6172 rhstype = non_reference (rhstype);
6174 type = complete_type (type);
6176 if (IS_AGGR_TYPE (type))
6177 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6179 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6182 /* If RETVAL is the address of, or a reference to, a local variable or
6183 temporary give an appropriate warning. */
6186 maybe_warn_about_returning_address_of_local (tree retval)
6188 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6189 tree whats_returned = retval;
6193 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6194 whats_returned = TREE_OPERAND (whats_returned, 1);
6195 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6196 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6197 || TREE_CODE (whats_returned) == NOP_EXPR)
6198 whats_returned = TREE_OPERAND (whats_returned, 0);
6203 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6205 whats_returned = TREE_OPERAND (whats_returned, 0);
6207 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6209 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6210 || TREE_CODE (whats_returned) == TARGET_EXPR)
6212 warning (0, "returning reference to temporary");
6215 if (TREE_CODE (whats_returned) == VAR_DECL
6216 && DECL_NAME (whats_returned)
6217 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6219 warning (0, "reference to non-lvalue returned");
6224 if (DECL_P (whats_returned)
6225 && DECL_NAME (whats_returned)
6226 && DECL_FUNCTION_SCOPE_P (whats_returned)
6227 && !(TREE_STATIC (whats_returned)
6228 || TREE_PUBLIC (whats_returned)))
6230 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6231 warning (0, "reference to local variable %q+D returned",
6234 warning (0, "address of local variable %q+D returned",
6240 /* Check that returning RETVAL from the current function is valid.
6241 Return an expression explicitly showing all conversions required to
6242 change RETVAL into the function return type, and to assign it to
6243 the DECL_RESULT for the function. Set *NO_WARNING to true if
6244 code reaches end of non-void function warning shouldn't be issued
6245 on this RETURN_EXPR. */
6248 check_return_expr (tree retval, bool *no_warning)
6251 /* The type actually returned by the function, after any
6254 int fn_returns_value_p;
6256 *no_warning = false;
6258 /* A `volatile' function is one that isn't supposed to return, ever.
6259 (This is a G++ extension, used to get better code for functions
6260 that call the `volatile' function.) */
6261 if (TREE_THIS_VOLATILE (current_function_decl))
6262 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6264 /* Check for various simple errors. */
6265 if (DECL_DESTRUCTOR_P (current_function_decl))
6268 error ("returning a value from a destructor");
6271 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6273 if (in_function_try_handler)
6274 /* If a return statement appears in a handler of the
6275 function-try-block of a constructor, the program is ill-formed. */
6276 error ("cannot return from a handler of a function-try-block of a constructor");
6278 /* You can't return a value from a constructor. */
6279 error ("returning a value from a constructor");
6283 if (processing_template_decl)
6285 current_function_returns_value = 1;
6289 /* When no explicit return-value is given in a function with a named
6290 return value, the named return value is used. */
6291 result = DECL_RESULT (current_function_decl);
6292 valtype = TREE_TYPE (result);
6293 gcc_assert (valtype != NULL_TREE);
6294 fn_returns_value_p = !VOID_TYPE_P (valtype);
6295 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6298 /* Check for a return statement with no return value in a function
6299 that's supposed to return a value. */
6300 if (!retval && fn_returns_value_p)
6302 pedwarn ("return-statement with no value, in function returning %qT",
6304 /* Clear this, so finish_function won't say that we reach the
6305 end of a non-void function (which we don't, we gave a
6307 current_function_returns_null = 0;
6308 /* And signal caller that TREE_NO_WARNING should be set on the
6309 RETURN_EXPR to avoid control reaches end of non-void function
6310 warnings in tree-cfg.c. */
6313 /* Check for a return statement with a value in a function that
6314 isn't supposed to return a value. */
6315 else if (retval && !fn_returns_value_p)
6317 if (VOID_TYPE_P (TREE_TYPE (retval)))
6318 /* You can return a `void' value from a function of `void'
6319 type. In that case, we have to evaluate the expression for
6320 its side-effects. */
6321 finish_expr_stmt (retval);
6323 pedwarn ("return-statement with a value, in function "
6324 "returning 'void'");
6326 current_function_returns_null = 1;
6328 /* There's really no value to return, after all. */
6332 /* Remember that this function can sometimes return without a
6334 current_function_returns_null = 1;
6336 /* Remember that this function did return a value. */
6337 current_function_returns_value = 1;
6339 /* Check for erroneous operands -- but after giving ourselves a
6340 chance to provide an error about returning a value from a void
6342 if (error_operand_p (retval))
6344 current_function_return_value = error_mark_node;
6345 return error_mark_node;
6348 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6349 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6350 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6351 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6353 && null_ptr_cst_p (retval))
6354 warning (0, "%<operator new%> must not return NULL unless it is "
6355 "declared %<throw()%> (or -fcheck-new is in effect)");
6357 /* Effective C++ rule 15. See also start_function. */
6359 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6363 /* The function return type must be a reference to the current
6365 if (TREE_CODE (valtype) == REFERENCE_TYPE
6366 && same_type_ignoring_top_level_qualifiers_p
6367 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6369 /* Returning '*this' is obviously OK. */
6370 if (retval == current_class_ref)
6372 /* If we are calling a function whose return type is the same of
6373 the current class reference, it is ok. */
6374 else if (TREE_CODE (retval) == INDIRECT_REF
6375 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6380 warning (0, "%<operator=%> should return a reference to %<*this%>");
6383 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6385 [...] For a function with a class return type, if the expression
6386 in the return statement is the name of a local object, and the cv-
6387 unqualified type of the local object is the same as the function
6388 return type, an implementation is permitted to omit creating the tem-
6389 porary object to hold the function return value [...]
6391 So, if this is a value-returning function that always returns the same
6392 local variable, remember it.
6394 It might be nice to be more flexible, and choose the first suitable
6395 variable even if the function sometimes returns something else, but
6396 then we run the risk of clobbering the variable we chose if the other
6397 returned expression uses the chosen variable somehow. And people expect
6398 this restriction, anyway. (jason 2000-11-19)
6400 See finish_function and finalize_nrv for the rest of this optimization. */
6402 if (fn_returns_value_p && flag_elide_constructors)
6404 if (retval != NULL_TREE
6405 && (current_function_return_value == NULL_TREE
6406 || current_function_return_value == retval)
6407 && TREE_CODE (retval) == VAR_DECL
6408 && DECL_CONTEXT (retval) == current_function_decl
6409 && ! TREE_STATIC (retval)
6410 && (DECL_ALIGN (retval)
6411 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6412 && same_type_p ((TYPE_MAIN_VARIANT
6413 (TREE_TYPE (retval))),
6415 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6416 current_function_return_value = retval;
6418 current_function_return_value = error_mark_node;
6421 /* We don't need to do any conversions when there's nothing being
6426 /* Do any required conversions. */
6427 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6428 /* No conversions are required. */
6432 /* The type the function is declared to return. */
6433 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6435 /* The functype's return type will have been set to void, if it
6436 was an incomplete type. Just treat this as 'return;' */
6437 if (VOID_TYPE_P (functype))
6438 return error_mark_node;
6440 /* First convert the value to the function's return type, then
6441 to the type of return value's location to handle the
6442 case that functype is smaller than the valtype. */
6443 retval = convert_for_initialization
6444 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6445 "return", NULL_TREE, 0);
6446 retval = convert (valtype, retval);
6448 /* If the conversion failed, treat this just like `return;'. */
6449 if (retval == error_mark_node)
6451 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6452 else if (! current_function_returns_struct
6453 && TREE_CODE (retval) == TARGET_EXPR
6454 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6455 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6456 TREE_OPERAND (retval, 0));
6458 maybe_warn_about_returning_address_of_local (retval);
6461 /* Actually copy the value returned into the appropriate location. */
6462 if (retval && retval != result)
6463 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6469 /* Returns nonzero if the pointer-type FROM can be converted to the
6470 pointer-type TO via a qualification conversion. If CONSTP is -1,
6471 then we return nonzero if the pointers are similar, and the
6472 cv-qualification signature of FROM is a proper subset of that of TO.
6474 If CONSTP is positive, then all outer pointers have been
6478 comp_ptr_ttypes_real (tree to, tree from, int constp)
6480 bool to_more_cv_qualified = false;
6482 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6484 if (TREE_CODE (to) != TREE_CODE (from))
6487 if (TREE_CODE (from) == OFFSET_TYPE
6488 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6489 TYPE_OFFSET_BASETYPE (to)))
6492 /* Const and volatile mean something different for function types,
6493 so the usual checks are not appropriate. */
6494 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6496 /* In Objective-C++, some types may have been 'volatilized' by
6497 the compiler for EH; when comparing them here, the volatile
6498 qualification must be ignored. */
6499 bool objc_quals_match = objc_type_quals_match (to, from);
6501 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6504 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6508 to_more_cv_qualified = true;
6512 constp &= TYPE_READONLY (to);
6515 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6516 return ((constp >= 0 || to_more_cv_qualified)
6517 && same_type_ignoring_top_level_qualifiers_p (to, from));
6521 /* When comparing, say, char ** to char const **, this function takes
6522 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6523 types to this function. */
6526 comp_ptr_ttypes (tree to, tree from)
6528 return comp_ptr_ttypes_real (to, from, 1);
6531 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6532 type or inheritance-related types, regardless of cv-quals. */
6535 ptr_reasonably_similar (tree to, tree from)
6537 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6539 /* Any target type is similar enough to void. */
6540 if (TREE_CODE (to) == VOID_TYPE
6541 || TREE_CODE (from) == VOID_TYPE)
6544 if (TREE_CODE (to) != TREE_CODE (from))
6547 if (TREE_CODE (from) == OFFSET_TYPE
6548 && comptypes (TYPE_OFFSET_BASETYPE (to),
6549 TYPE_OFFSET_BASETYPE (from),
6550 COMPARE_BASE | COMPARE_DERIVED))
6553 if (TREE_CODE (to) == VECTOR_TYPE
6554 && vector_types_convertible_p (to, from))
6557 if (TREE_CODE (to) == INTEGER_TYPE
6558 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6561 if (TREE_CODE (to) == FUNCTION_TYPE)
6564 if (TREE_CODE (to) != POINTER_TYPE)
6566 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6567 COMPARE_BASE | COMPARE_DERIVED);
6571 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6572 pointer-to-member types) are the same, ignoring cv-qualification at
6576 comp_ptr_ttypes_const (tree to, tree from)
6578 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6580 if (TREE_CODE (to) != TREE_CODE (from))
6583 if (TREE_CODE (from) == OFFSET_TYPE
6584 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6585 TYPE_OFFSET_BASETYPE (to)))
6588 if (TREE_CODE (to) != POINTER_TYPE)
6589 return same_type_ignoring_top_level_qualifiers_p (to, from);
6593 /* Returns the type qualifiers for this type, including the qualifiers on the
6594 elements for an array type. */
6597 cp_type_quals (tree type)
6599 type = strip_array_types (type);
6600 if (type == error_mark_node)
6601 return TYPE_UNQUALIFIED;
6602 return TYPE_QUALS (type);
6605 /* Returns nonzero if the TYPE contains a mutable member. */
6608 cp_has_mutable_p (tree type)
6610 type = strip_array_types (type);
6612 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6615 /* Apply the TYPE_QUALS to the new DECL. */
6617 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6619 tree type = TREE_TYPE (decl);
6621 if (type == error_mark_node)
6624 if (TREE_CODE (type) == FUNCTION_TYPE
6625 && type_quals != TYPE_UNQUALIFIED)
6627 /* This was an error in C++98 (cv-qualifiers cannot be added to
6628 a function type), but DR 295 makes the code well-formed by
6629 dropping the extra qualifiers. */
6632 tree bad_type = build_qualified_type (type, type_quals);
6633 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6637 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6641 /* Avoid setting TREE_READONLY incorrectly. */
6642 if (/* If the object has a constructor, the constructor may modify
6644 TYPE_NEEDS_CONSTRUCTING (type)
6645 /* If the type isn't complete, we don't know yet if it will need
6647 || !COMPLETE_TYPE_P (type)
6648 /* If the type has a mutable component, that component might be
6650 || TYPE_HAS_MUTABLE_P (type))
6651 type_quals &= ~TYPE_QUAL_CONST;
6653 c_apply_type_quals_to_decl (type_quals, decl);
6656 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6657 exemplar types such that casting T1 to T2 is casting away constness
6658 if and only if there is no implicit conversion from T1 to T2. */
6661 casts_away_constness_r (tree *t1, tree *t2)
6666 /* [expr.const.cast]
6668 For multi-level pointer to members and multi-level mixed pointers
6669 and pointers to members (conv.qual), the "member" aspect of a
6670 pointer to member level is ignored when determining if a const
6671 cv-qualifier has been cast away. */
6672 /* [expr.const.cast]
6674 For two pointer types:
6676 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6677 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6680 casting from X1 to X2 casts away constness if, for a non-pointer
6681 type T there does not exist an implicit conversion (clause
6684 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6688 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6689 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6690 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6692 *t1 = cp_build_qualified_type (void_type_node,
6693 cp_type_quals (*t1));
6694 *t2 = cp_build_qualified_type (void_type_node,
6695 cp_type_quals (*t2));
6699 quals1 = cp_type_quals (*t1);
6700 quals2 = cp_type_quals (*t2);
6702 if (TYPE_PTRMEM_P (*t1))
6703 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6705 *t1 = TREE_TYPE (*t1);
6706 if (TYPE_PTRMEM_P (*t2))
6707 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6709 *t2 = TREE_TYPE (*t2);
6711 casts_away_constness_r (t1, t2);
6712 *t1 = build_pointer_type (*t1);
6713 *t2 = build_pointer_type (*t2);
6714 *t1 = cp_build_qualified_type (*t1, quals1);
6715 *t2 = cp_build_qualified_type (*t2, quals2);
6718 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6722 casts_away_constness (tree t1, tree t2)
6724 if (TREE_CODE (t2) == REFERENCE_TYPE)
6726 /* [expr.const.cast]
6728 Casting from an lvalue of type T1 to an lvalue of type T2
6729 using a reference cast casts away constness if a cast from an
6730 rvalue of type "pointer to T1" to the type "pointer to T2"
6731 casts away constness. */
6732 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6733 return casts_away_constness (build_pointer_type (t1),
6734 build_pointer_type (TREE_TYPE (t2)));
6737 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6738 /* [expr.const.cast]
6740 Casting from an rvalue of type "pointer to data member of X
6741 of type T1" to the type "pointer to data member of Y of type
6742 T2" casts away constness if a cast from an rvalue of type
6743 "pointer to T1" to the type "pointer to T2" casts away
6745 return casts_away_constness
6746 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6747 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6749 /* Casting away constness is only something that makes sense for
6750 pointer or reference types. */
6751 if (TREE_CODE (t1) != POINTER_TYPE
6752 || TREE_CODE (t2) != POINTER_TYPE)
6755 /* Top-level qualifiers don't matter. */
6756 t1 = TYPE_MAIN_VARIANT (t1);
6757 t2 = TYPE_MAIN_VARIANT (t2);
6758 casts_away_constness_r (&t1, &t2);
6759 if (!can_convert (t2, t1))
6765 /* If T is a REFERENCE_TYPE return the type to which T refers.
6766 Otherwise, return T itself. */
6769 non_reference (tree t)
6771 if (TREE_CODE (t) == REFERENCE_TYPE)
6777 /* Return nonzero if REF is an lvalue valid for this language;
6778 otherwise, print an error message and return zero. USE says
6779 how the lvalue is being used and so selects the error message. */
6782 lvalue_or_else (tree ref, enum lvalue_use use)
6784 int win = lvalue_p (ref);