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 pfn_from_ptrmemfunc (tree);
47 static tree convert_for_assignment (tree, tree, const char *, tree, int);
48 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
49 static tree rationalize_conditional_expr (enum tree_code, tree);
50 static int comp_ptr_ttypes_real (tree, tree, int);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
60 static tree convert_arguments (tree, tree, tree, int);
62 /* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
68 require_complete_type (tree value)
72 if (processing_template_decl || value == error_mark_node)
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
78 type = TREE_TYPE (value);
80 if (type == error_mark_node)
81 return error_mark_node;
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
87 if (complete_type_or_else (type, value))
90 return error_mark_node;
93 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
99 complete_type (tree type)
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
104 return error_mark_node;
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
110 tree t = complete_type (TREE_TYPE (type));
111 unsigned int needs_constructing, has_nontrivial_dtor;
112 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
115 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
117 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
120 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
121 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
124 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
125 instantiate_class_template (TYPE_MAIN_VARIANT (type));
130 /* Like complete_type, but issue an error if the TYPE cannot be completed.
131 VALUE is used for informative diagnostics.
132 Returns NULL_TREE if the type cannot be made complete. */
135 complete_type_or_else (tree type, tree value)
137 type = complete_type (type);
138 if (type == error_mark_node)
139 /* We already issued an error. */
141 else if (!COMPLETE_TYPE_P (type))
143 cxx_incomplete_type_diagnostic (value, type, 0);
150 /* Return truthvalue of whether type of EXP is instantiated. */
153 type_unknown_p (tree exp)
155 return (TREE_CODE (exp) == TREE_LIST
156 || TREE_TYPE (exp) == unknown_type_node);
160 /* Return the common type of two parameter lists.
161 We assume that comptypes has already been done and returned 1;
162 if that isn't so, this may crash.
164 As an optimization, free the space we allocate if the parameter
165 lists are already common. */
168 commonparms (tree p1, tree p2)
170 tree oldargs = p1, newargs, n;
174 len = list_length (p1);
175 newargs = tree_last (p1);
177 if (newargs == void_list_node)
186 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
191 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
193 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
195 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
198 else if (! TREE_PURPOSE (p1))
200 if (TREE_PURPOSE (p2))
202 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
208 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
210 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
212 if (TREE_VALUE (p1) != TREE_VALUE (p2))
215 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
218 TREE_VALUE (n) = TREE_VALUE (p1);
226 /* Given a type, perhaps copied for a typedef,
227 find the "original" version of it. */
229 original_type (tree t)
231 int quals = cp_type_quals (t);
232 while (t != error_mark_node
233 && TYPE_NAME (t) != NULL_TREE)
235 tree x = TYPE_NAME (t);
236 if (TREE_CODE (x) != TYPE_DECL)
238 x = DECL_ORIGINAL_TYPE (x);
243 return cp_build_qualified_type (t, quals);
246 /* T1 and T2 are arithmetic or enumeration types. Return the type
247 that will result from the "usual arithmetic conversions" on T1 and
248 T2 as described in [expr]. */
251 type_after_usual_arithmetic_conversions (tree t1, tree t2)
253 enum tree_code code1 = TREE_CODE (t1);
254 enum tree_code code2 = TREE_CODE (t2);
257 /* FIXME: Attributes. */
258 gcc_assert (ARITHMETIC_TYPE_P (t1)
259 || TREE_CODE (t1) == VECTOR_TYPE
260 || TREE_CODE (t1) == ENUMERAL_TYPE);
261 gcc_assert (ARITHMETIC_TYPE_P (t2)
262 || TREE_CODE (t2) == VECTOR_TYPE
263 || TREE_CODE (t2) == ENUMERAL_TYPE);
265 /* In what follows, we slightly generalize the rules given in [expr] so
266 as to deal with `long long' and `complex'. First, merge the
268 attributes = (*targetm.merge_type_attributes) (t1, t2);
270 /* If one type is complex, form the common type of the non-complex
271 components, then make that complex. Use T1 or T2 if it is the
273 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
275 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
276 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
278 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
280 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
281 return build_type_attribute_variant (t1, attributes);
282 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
283 return build_type_attribute_variant (t2, attributes);
285 return build_type_attribute_variant (build_complex_type (subtype),
289 if (code1 == VECTOR_TYPE)
291 /* When we get here we should have two vectors of the same size.
292 Just prefer the unsigned one if present. */
293 if (TYPE_UNSIGNED (t1))
294 return build_type_attribute_variant (t1, attributes);
296 return build_type_attribute_variant (t2, attributes);
299 /* If only one is real, use it as the result. */
300 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
301 return build_type_attribute_variant (t1, attributes);
302 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
303 return build_type_attribute_variant (t2, attributes);
305 /* Perform the integral promotions. */
306 if (code1 != REAL_TYPE)
308 t1 = type_promotes_to (t1);
309 t2 = type_promotes_to (t2);
312 /* Both real or both integers; use the one with greater precision. */
313 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
314 return build_type_attribute_variant (t1, attributes);
315 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
316 return build_type_attribute_variant (t2, attributes);
318 /* The types are the same; no need to do anything fancy. */
319 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
320 return build_type_attribute_variant (t1, attributes);
322 if (code1 != REAL_TYPE)
324 /* If one is a sizetype, use it so size_binop doesn't blow up. */
325 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
326 return build_type_attribute_variant (t1, attributes);
327 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
328 return build_type_attribute_variant (t2, attributes);
330 /* If one is unsigned long long, then convert the other to unsigned
332 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
333 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
334 return build_type_attribute_variant (long_long_unsigned_type_node,
336 /* If one is a long long, and the other is an unsigned long, and
337 long long can represent all the values of an unsigned long, then
338 convert to a long long. Otherwise, convert to an unsigned long
339 long. Otherwise, if either operand is long long, convert the
342 Since we're here, we know the TYPE_PRECISION is the same;
343 therefore converting to long long cannot represent all the values
344 of an unsigned long, so we choose unsigned long long in that
346 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
347 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
349 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
350 ? long_long_unsigned_type_node
351 : long_long_integer_type_node);
352 return build_type_attribute_variant (t, attributes);
355 /* Go through the same procedure, but for longs. */
356 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
357 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
358 return build_type_attribute_variant (long_unsigned_type_node,
360 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
361 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
363 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
364 ? long_unsigned_type_node : long_integer_type_node);
365 return build_type_attribute_variant (t, attributes);
367 /* Otherwise prefer the unsigned one. */
368 if (TYPE_UNSIGNED (t1))
369 return build_type_attribute_variant (t1, attributes);
371 return build_type_attribute_variant (t2, attributes);
375 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
376 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
377 return build_type_attribute_variant (long_double_type_node,
379 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
380 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
381 return build_type_attribute_variant (double_type_node,
383 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
384 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
385 return build_type_attribute_variant (float_type_node,
388 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
389 the standard C++ floating-point types. Logic earlier in this
390 function has already eliminated the possibility that
391 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
392 compelling reason to choose one or the other. */
393 return build_type_attribute_variant (t1, attributes);
397 /* Subroutine of composite_pointer_type to implement the recursive
398 case. See that function for documentation fo the parameters. */
401 composite_pointer_type_r (tree t1, tree t2, const char* location)
408 /* Determine the types pointed to by T1 and T2. */
409 if (TREE_CODE (t1) == POINTER_TYPE)
411 pointee1 = TREE_TYPE (t1);
412 pointee2 = TREE_TYPE (t2);
416 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
417 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
422 Otherwise, the composite pointer type is a pointer type
423 similar (_conv.qual_) to the type of one of the operands,
424 with a cv-qualification signature (_conv.qual_) that is the
425 union of the cv-qualification signatures of the operand
427 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
428 result_type = pointee1;
429 else if ((TREE_CODE (pointee1) == POINTER_TYPE
430 && TREE_CODE (pointee2) == POINTER_TYPE)
431 || (TYPE_PTR_TO_MEMBER_P (pointee1)
432 && TYPE_PTR_TO_MEMBER_P (pointee2)))
433 result_type = composite_pointer_type_r (pointee1, pointee2, location);
436 pedwarn ("%s between distinct pointer types %qT and %qT "
439 result_type = void_type_node;
441 result_type = cp_build_qualified_type (result_type,
442 (cp_type_quals (pointee1)
443 | cp_type_quals (pointee2)));
444 /* If the original types were pointers to members, so is the
446 if (TYPE_PTR_TO_MEMBER_P (t1))
448 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
449 TYPE_PTRMEM_CLASS_TYPE (t2)))
450 pedwarn ("%s between distinct pointer types %qT and %qT "
453 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
457 result_type = build_pointer_type (result_type);
459 /* Merge the attributes. */
460 attributes = (*targetm.merge_type_attributes) (t1, t2);
461 return build_type_attribute_variant (result_type, attributes);
464 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
465 ARG1 and ARG2 are the values with those types. The LOCATION is a
466 string describing the current location, in case an error occurs.
468 This routine also implements the computation of a common type for
469 pointers-to-members as per [expr.eq]. */
472 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
473 const char* location)
480 If one operand is a null pointer constant, the composite pointer
481 type is the type of the other operand. */
482 if (null_ptr_cst_p (arg1))
484 if (null_ptr_cst_p (arg2))
491 If one of the operands has type "pointer to cv1 void*", then
492 the other has type "pointer to cv2T", and the composite pointer
493 type is "pointer to cv12 void", where cv12 is the union of cv1
496 If either type is a pointer to void, make sure it is T1. */
497 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
505 /* Now, if T1 is a pointer to void, merge the qualifiers. */
506 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
511 if (pedantic && TYPE_PTRFN_P (t2))
512 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
513 "and pointer-to-function", location);
515 = cp_build_qualified_type (void_type_node,
516 (cp_type_quals (TREE_TYPE (t1))
517 | cp_type_quals (TREE_TYPE (t2))));
518 result_type = build_pointer_type (result_type);
519 /* Merge the attributes. */
520 attributes = (*targetm.merge_type_attributes) (t1, t2);
521 return build_type_attribute_variant (result_type, attributes);
524 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
525 && TREE_CODE (t2) == POINTER_TYPE)
527 if (objc_compare_types (t1, t2, -3, NULL_TREE))
531 /* [expr.eq] permits the application of a pointer conversion to
532 bring the pointers to a common type. */
533 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
534 && CLASS_TYPE_P (TREE_TYPE (t1))
535 && CLASS_TYPE_P (TREE_TYPE (t2))
536 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
539 class1 = TREE_TYPE (t1);
540 class2 = TREE_TYPE (t2);
542 if (DERIVED_FROM_P (class1, class2))
543 t2 = (build_pointer_type
544 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
545 else if (DERIVED_FROM_P (class2, class1))
546 t1 = (build_pointer_type
547 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
550 error ("%s between distinct pointer types %qT and %qT "
551 "lacks a cast", location, t1, t2);
552 return error_mark_node;
555 /* [expr.eq] permits the application of a pointer-to-member
556 conversion to change the class type of one of the types. */
557 else if (TYPE_PTR_TO_MEMBER_P (t1)
558 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
559 TYPE_PTRMEM_CLASS_TYPE (t2)))
561 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
562 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
564 if (DERIVED_FROM_P (class1, class2))
565 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
566 else if (DERIVED_FROM_P (class2, class1))
567 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
570 error ("%s between distinct pointer-to-member types %qT and %qT "
571 "lacks a cast", location, t1, t2);
572 return error_mark_node;
576 return composite_pointer_type_r (t1, t2, location);
579 /* Return the merged type of two types.
580 We assume that comptypes has already been done and returned 1;
581 if that isn't so, this may crash.
583 This just combines attributes and default arguments; any other
584 differences would cause the two types to compare unalike. */
587 merge_types (tree t1, tree t2)
589 enum tree_code code1;
590 enum tree_code code2;
593 /* Save time if the two types are the same. */
596 if (original_type (t1) == original_type (t2))
599 /* If one type is nonsense, use the other. */
600 if (t1 == error_mark_node)
602 if (t2 == error_mark_node)
605 /* Merge the attributes. */
606 attributes = (*targetm.merge_type_attributes) (t1, t2);
608 if (TYPE_PTRMEMFUNC_P (t1))
609 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
610 if (TYPE_PTRMEMFUNC_P (t2))
611 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
613 code1 = TREE_CODE (t1);
614 code2 = TREE_CODE (t2);
620 /* For two pointers, do this recursively on the target type. */
622 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
623 int quals = cp_type_quals (t1);
625 if (code1 == POINTER_TYPE)
626 t1 = build_pointer_type (target);
628 t1 = build_reference_type (target);
629 t1 = build_type_attribute_variant (t1, attributes);
630 t1 = cp_build_qualified_type (t1, quals);
632 if (TREE_CODE (target) == METHOD_TYPE)
633 t1 = build_ptrmemfunc_type (t1);
642 quals = cp_type_quals (t1);
643 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
644 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
645 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
647 t1 = cp_build_qualified_type (t1, quals);
653 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
654 /* Save space: see if the result is identical to one of the args. */
655 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
656 return build_type_attribute_variant (t1, attributes);
657 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
658 return build_type_attribute_variant (t2, attributes);
659 /* Merge the element types, and have a size if either arg has one. */
660 t1 = build_cplus_array_type
661 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
666 /* Function types: prefer the one that specified arg types.
667 If both do, merge the arg types. Also merge the return types. */
669 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
670 tree p1 = TYPE_ARG_TYPES (t1);
671 tree p2 = TYPE_ARG_TYPES (t2);
674 /* Save space: see if the result is identical to one of the args. */
675 if (valtype == TREE_TYPE (t1) && ! p2)
676 return cp_build_type_attribute_variant (t1, attributes);
677 if (valtype == TREE_TYPE (t2) && ! p1)
678 return cp_build_type_attribute_variant (t2, attributes);
680 /* Simple way if one arg fails to specify argument types. */
681 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
683 rval = build_function_type (valtype, p2);
684 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
685 rval = build_exception_variant (rval, raises);
686 return cp_build_type_attribute_variant (rval, attributes);
688 raises = TYPE_RAISES_EXCEPTIONS (t1);
689 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
691 rval = build_function_type (valtype, p1);
693 rval = build_exception_variant (rval, raises);
694 return cp_build_type_attribute_variant (rval, attributes);
697 rval = build_function_type (valtype, commonparms (p1, p2));
698 t1 = build_exception_variant (rval, raises);
704 /* Get this value the long way, since TYPE_METHOD_BASETYPE
705 is just the main variant of this. */
706 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
707 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
710 /* If this was a member function type, get back to the
711 original type of type member function (i.e., without
712 the class instance variable up front. */
713 t1 = build_function_type (TREE_TYPE (t1),
714 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
715 t2 = build_function_type (TREE_TYPE (t2),
716 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
717 t3 = merge_types (t1, t2);
718 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
719 TYPE_ARG_TYPES (t3));
720 t1 = build_exception_variant (t3, raises);
725 /* There is no need to merge attributes into a TYPENAME_TYPE.
726 When the type is instantiated it will have whatever
727 attributes result from the instantiation. */
733 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
735 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
738 return cp_build_type_attribute_variant (t1, attributes);
741 /* Return the common type of two types.
742 We assume that comptypes has already been done and returned 1;
743 if that isn't so, this may crash.
745 This is the type for the result of most arithmetic operations
746 if the operands have the given two types. */
749 common_type (tree t1, tree t2)
751 enum tree_code code1;
752 enum tree_code code2;
754 /* If one type is nonsense, bail. */
755 if (t1 == error_mark_node || t2 == error_mark_node)
756 return error_mark_node;
758 code1 = TREE_CODE (t1);
759 code2 = TREE_CODE (t2);
761 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
762 || code1 == VECTOR_TYPE)
763 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
764 || code2 == VECTOR_TYPE))
765 return type_after_usual_arithmetic_conversions (t1, t2);
767 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
768 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
769 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
770 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
776 /* Compare two exception specifier types for exactness or subsetness, if
777 allowed. Returns false for mismatch, true for match (same, or
780 [except.spec] "If a class X ... objects of class X or any class publicly
781 and unambiguously derived from X. Similarly, if a pointer type Y * ...
782 exceptions of type Y * or that are pointers to any type publicly and
783 unambiguously derived from Y. Otherwise a function only allows exceptions
784 that have the same type ..."
785 This does not mention cv qualifiers and is different to what throw
786 [except.throw] and catch [except.catch] will do. They will ignore the
787 top level cv qualifiers, and allow qualifiers in the pointer to class
790 We implement the letter of the standard. */
793 comp_except_types (tree a, tree b, bool exact)
795 if (same_type_p (a, b))
799 if (cp_type_quals (a) || cp_type_quals (b))
802 if (TREE_CODE (a) == POINTER_TYPE
803 && TREE_CODE (b) == POINTER_TYPE)
807 if (cp_type_quals (a) || cp_type_quals (b))
811 if (TREE_CODE (a) != RECORD_TYPE
812 || TREE_CODE (b) != RECORD_TYPE)
815 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
821 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
822 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
823 otherwise it must be exact. Exception lists are unordered, but
824 we've already filtered out duplicates. Most lists will be in order,
825 we should try to make use of that. */
828 comp_except_specs (tree t1, tree t2, bool exact)
837 if (t1 == NULL_TREE) /* T1 is ... */
838 return t2 == NULL_TREE || !exact;
839 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
840 return t2 != NULL_TREE && !TREE_VALUE (t2);
841 if (t2 == NULL_TREE) /* T2 is ... */
843 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
846 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
847 Count how many we find, to determine exactness. For exact matching and
848 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
850 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
852 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
854 tree a = TREE_VALUE (probe);
855 tree b = TREE_VALUE (t2);
857 if (comp_except_types (a, b, exact))
859 if (probe == base && exact)
860 base = TREE_CHAIN (probe);
865 if (probe == NULL_TREE)
868 return !exact || base == NULL_TREE || length == list_length (t1);
871 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
872 [] can match [size]. */
875 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
884 /* The type of the array elements must be the same. */
885 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
888 d1 = TYPE_DOMAIN (t1);
889 d2 = TYPE_DOMAIN (t2);
894 /* If one of the arrays is dimensionless, and the other has a
895 dimension, they are of different types. However, it is valid to
903 declarations for an array object can specify
904 array types that differ by the presence or absence of a major
905 array bound (_dcl.array_). */
907 return allow_redeclaration;
909 /* Check that the dimensions are the same. */
911 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
913 max1 = TYPE_MAX_VALUE (d1);
914 max2 = TYPE_MAX_VALUE (d2);
915 if (processing_template_decl && !abi_version_at_least (2)
916 && !value_dependent_expression_p (max1)
917 && !value_dependent_expression_p (max2))
919 /* With abi-1 we do not fold non-dependent array bounds, (and
920 consequently mangle them incorrectly). We must therefore
921 fold them here, to verify the domains have the same
927 if (!cp_tree_equal (max1, max2))
933 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
934 is a bitwise-or of the COMPARE_* flags. */
937 comptypes (tree t1, tree t2, int strict)
942 /* Suppress errors caused by previously reported errors. */
943 if (t1 == error_mark_node || t2 == error_mark_node)
946 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
948 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
949 current instantiation. */
950 if (TREE_CODE (t1) == TYPENAME_TYPE)
952 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
954 if (resolved != error_mark_node)
958 if (TREE_CODE (t2) == TYPENAME_TYPE)
960 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
962 if (resolved != error_mark_node)
966 /* If either type is the internal version of sizetype, use the
968 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
969 && TYPE_ORIG_SIZE_TYPE (t1))
970 t1 = TYPE_ORIG_SIZE_TYPE (t1);
972 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
973 && TYPE_ORIG_SIZE_TYPE (t2))
974 t2 = TYPE_ORIG_SIZE_TYPE (t2);
976 if (TYPE_PTRMEMFUNC_P (t1))
977 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
978 if (TYPE_PTRMEMFUNC_P (t2))
979 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
981 /* Different classes of types can't be compatible. */
982 if (TREE_CODE (t1) != TREE_CODE (t2))
985 /* Qualifiers must match. For array types, we will check when we
986 recur on the array element types. */
987 if (TREE_CODE (t1) != ARRAY_TYPE
988 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
990 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
993 /* Allow for two different type nodes which have essentially the same
994 definition. Note that we already checked for equality of the type
995 qualifiers (just above). */
997 if (TREE_CODE (t1) != ARRAY_TYPE
998 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
1001 /* Compare the types. Break out if they could be the same. */
1002 switch (TREE_CODE (t1))
1004 case TEMPLATE_TEMPLATE_PARM:
1005 case BOUND_TEMPLATE_TEMPLATE_PARM:
1006 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1007 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1009 if (!comp_template_parms
1010 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1011 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1013 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1015 /* Don't check inheritance. */
1016 strict = COMPARE_STRICT;
1021 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1022 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1023 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1024 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1027 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1029 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1035 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1036 strict & ~COMPARE_REDECLARATION))
1038 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1043 case REFERENCE_TYPE:
1044 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1045 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1046 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1052 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1054 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1059 /* Target types must match incl. qualifiers. */
1060 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1064 case TEMPLATE_TYPE_PARM:
1065 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1066 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1071 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1072 TYPENAME_TYPE_FULLNAME (t2)))
1074 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1078 case UNBOUND_CLASS_TEMPLATE:
1079 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1081 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1086 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1091 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1092 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1100 /* If we get here, we know that from a target independent POV the
1101 types are the same. Make sure the target attributes are also
1103 return targetm.comp_type_attributes (t1, t2);
1106 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1109 at_least_as_qualified_p (tree type1, tree type2)
1111 int q1 = cp_type_quals (type1);
1112 int q2 = cp_type_quals (type2);
1114 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1115 return (q1 & q2) == q2;
1118 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1119 more cv-qualified that TYPE1, and 0 otherwise. */
1122 comp_cv_qualification (tree type1, tree type2)
1124 int q1 = cp_type_quals (type1);
1125 int q2 = cp_type_quals (type2);
1130 if ((q1 & q2) == q2)
1132 else if ((q1 & q2) == q1)
1138 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1139 subset of the cv-qualification signature of TYPE2, and the types
1140 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1143 comp_cv_qual_signature (tree type1, tree type2)
1145 if (comp_ptr_ttypes_real (type2, type1, -1))
1147 else if (comp_ptr_ttypes_real (type1, type2, -1))
1153 /* If two types share a common base type, return that basetype.
1154 If there is not a unique most-derived base type, this function
1155 returns ERROR_MARK_NODE. */
1158 common_base_type (tree tt1, tree tt2)
1160 tree best = NULL_TREE;
1163 /* If one is a baseclass of another, that's good enough. */
1164 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1166 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1169 /* Otherwise, try to find a unique baseclass of TT1
1170 that is shared by TT2, and follow that down. */
1171 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1173 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1174 tree trial = common_base_type (basetype, tt2);
1178 if (trial == error_mark_node)
1180 if (best == NULL_TREE)
1182 else if (best != trial)
1183 return error_mark_node;
1188 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1190 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1191 tree trial = common_base_type (tt1, basetype);
1195 if (trial == error_mark_node)
1197 if (best == NULL_TREE)
1199 else if (best != trial)
1200 return error_mark_node;
1206 /* Subroutines of `comptypes'. */
1208 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1209 equivalent in the sense that functions with those parameter types
1210 can have equivalent types. The two lists must be equivalent,
1211 element by element. */
1214 compparms (tree parms1, tree parms2)
1218 /* An unspecified parmlist matches any specified parmlist
1219 whose argument types don't need default promotions. */
1221 for (t1 = parms1, t2 = parms2;
1223 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1225 /* If one parmlist is shorter than the other,
1226 they fail to match. */
1229 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1236 /* Process a sizeof or alignof expression where the operand is a
1240 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1245 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1246 if (type == error_mark_node)
1247 return error_mark_node;
1249 type = non_reference (type);
1250 if (TREE_CODE (type) == METHOD_TYPE)
1252 if (complain && (pedantic || warn_pointer_arith))
1253 pedwarn ("invalid application of %qs to a member function",
1254 operator_name_info[(int) op].name);
1255 value = size_one_node;
1258 dependent_p = dependent_type_p (type);
1260 complete_type (type);
1262 /* VLA types will have a non-constant size. In the body of an
1263 uninstantiated template, we don't need to try to compute the
1264 value, because the sizeof expression is not an integral
1265 constant expression in that case. And, if we do try to
1266 compute the value, we'll likely end up with SAVE_EXPRs, which
1267 the template substitution machinery does not expect to see. */
1268 || (processing_template_decl
1269 && COMPLETE_TYPE_P (type)
1270 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1272 value = build_min (op, size_type_node, type);
1273 TREE_READONLY (value) = 1;
1277 return c_sizeof_or_alignof_type (complete_type (type),
1282 /* Process a sizeof expression where the operand is an expression. */
1285 cxx_sizeof_expr (tree e)
1287 if (e == error_mark_node)
1288 return error_mark_node;
1290 if (processing_template_decl)
1292 e = build_min (SIZEOF_EXPR, size_type_node, e);
1293 TREE_SIDE_EFFECTS (e) = 0;
1294 TREE_READONLY (e) = 1;
1299 if (TREE_CODE (e) == COMPONENT_REF
1300 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1301 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1303 error ("invalid application of %<sizeof%> to a bit-field");
1306 else if (is_overloaded_fn (e))
1308 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1312 else if (type_unknown_p (e))
1314 cxx_incomplete_type_error (e, TREE_TYPE (e));
1320 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1323 /* Implement the __alignof keyword: Return the minimum required
1324 alignment of E, measured in bytes. For VAR_DECL's and
1325 FIELD_DECL's return DECL_ALIGN (which can be set from an
1326 "aligned" __attribute__ specification). */
1329 cxx_alignof_expr (tree e)
1333 if (e == error_mark_node)
1334 return error_mark_node;
1336 if (processing_template_decl)
1338 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1339 TREE_SIDE_EFFECTS (e) = 0;
1340 TREE_READONLY (e) = 1;
1345 if (TREE_CODE (e) == VAR_DECL)
1346 t = size_int (DECL_ALIGN_UNIT (e));
1347 else if (TREE_CODE (e) == COMPONENT_REF
1348 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1349 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1351 error ("invalid application of %<__alignof%> to a bit-field");
1354 else if (TREE_CODE (e) == COMPONENT_REF
1355 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1356 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1357 else if (is_overloaded_fn (e))
1359 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1363 else if (type_unknown_p (e))
1365 cxx_incomplete_type_error (e, TREE_TYPE (e));
1369 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1371 return fold_convert (size_type_node, t);
1374 /* Process a sizeof or alignof expression E with code OP where the operand
1375 is an expression. */
1378 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1380 if (op == SIZEOF_EXPR)
1381 return cxx_sizeof_expr (e);
1383 return cxx_alignof_expr (e);
1386 /* EXPR is being used in a context that is not a function call.
1391 The expression can be used only as the left-hand operand of a
1392 member function call.
1394 [expr.mptr.operator]
1396 If the result of .* or ->* is a function, then that result can be
1397 used only as the operand for the function call operator ().
1399 by issuing an error message if appropriate. Returns true iff EXPR
1400 violates these rules. */
1403 invalid_nonstatic_memfn_p (tree expr)
1405 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1407 error ("invalid use of non-static member function");
1413 /* If EXP is a reference to a bitfield, and the type of EXP does not
1414 match the declared type of the bitfield, return the declared type
1415 of the bitfield. Otherwise, return NULL_TREE. */
1418 is_bitfield_expr_with_lowered_type (tree exp)
1420 switch (TREE_CODE (exp))
1423 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1425 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1428 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1432 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1438 field = TREE_OPERAND (exp, 1);
1439 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1441 if (same_type_ignoring_top_level_qualifiers_p
1442 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1444 return DECL_BIT_FIELD_TYPE (field);
1452 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1453 bitfield with a lowered type, the type of EXP is returned, rather
1457 unlowered_expr_type (tree exp)
1461 type = is_bitfield_expr_with_lowered_type (exp);
1463 type = TREE_TYPE (exp);
1468 /* Perform the conversions in [expr] that apply when an lvalue appears
1469 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1470 function-to-pointer conversions. In addition, manifest constants
1471 are replaced by their values, and bitfield references are converted
1472 to their declared types.
1474 Although the returned value is being used as an rvalue, this
1475 function does not wrap the returned expression in a
1476 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1477 that the return value is no longer an lvalue. */
1480 decay_conversion (tree exp)
1483 enum tree_code code;
1485 type = TREE_TYPE (exp);
1486 if (type == error_mark_node)
1487 return error_mark_node;
1489 if (type_unknown_p (exp))
1491 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1492 return error_mark_node;
1495 exp = decl_constant_value (exp);
1496 if (error_operand_p (exp))
1497 return error_mark_node;
1499 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1500 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1501 code = TREE_CODE (type);
1502 if (code == VOID_TYPE)
1504 error ("void value not ignored as it ought to be");
1505 return error_mark_node;
1507 if (invalid_nonstatic_memfn_p (exp))
1508 return error_mark_node;
1509 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1510 return build_unary_op (ADDR_EXPR, exp, 0);
1511 if (code == ARRAY_TYPE)
1516 if (TREE_CODE (exp) == INDIRECT_REF)
1517 return build_nop (build_pointer_type (TREE_TYPE (type)),
1518 TREE_OPERAND (exp, 0));
1520 if (TREE_CODE (exp) == COMPOUND_EXPR)
1522 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1523 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1524 TREE_OPERAND (exp, 0), op1);
1528 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1530 error ("invalid use of non-lvalue array");
1531 return error_mark_node;
1534 ptrtype = build_pointer_type (TREE_TYPE (type));
1536 if (TREE_CODE (exp) == VAR_DECL)
1538 if (!cxx_mark_addressable (exp))
1539 return error_mark_node;
1540 adr = build_nop (ptrtype, build_address (exp));
1543 /* This way is better for a COMPONENT_REF since it can
1544 simplify the offset for a component. */
1545 adr = build_unary_op (ADDR_EXPR, exp, 1);
1546 return cp_convert (ptrtype, adr);
1549 /* If a bitfield is used in a context where integral promotion
1550 applies, then the caller is expected to have used
1551 default_conversion. That function promotes bitfields correctly
1552 before calling this function. At this point, if we have a
1553 bitfield referenced, we may assume that is not subject to
1554 promotion, and that, therefore, the type of the resulting rvalue
1555 is the declared type of the bitfield. */
1556 exp = convert_bitfield_to_declared_type (exp);
1558 /* We do not call rvalue() here because we do not want to wrap EXP
1559 in a NON_LVALUE_EXPR. */
1563 Non-class rvalues always have cv-unqualified types. */
1564 type = TREE_TYPE (exp);
1565 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1566 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1571 /* Perform prepatory conversions, as part of the "usual arithmetic
1572 conversions". In particular, as per [expr]:
1574 Whenever an lvalue expression appears as an operand of an
1575 operator that expects the rvalue for that operand, the
1576 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1577 standard conversions are applied to convert the expression to an
1580 In addition, we perform integral promotions here, as those are
1581 applied to both operands to a binary operator before determining
1582 what additional conversions should apply. */
1585 default_conversion (tree exp)
1587 /* Perform the integral promotions first so that bitfield
1588 expressions (which may promote to "int", even if the bitfield is
1589 declared "unsigned") are promoted correctly. */
1590 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1591 exp = perform_integral_promotions (exp);
1592 /* Perform the other conversions. */
1593 exp = decay_conversion (exp);
1598 /* EXPR is an expression with an integral or enumeration type.
1599 Perform the integral promotions in [conv.prom], and return the
1603 perform_integral_promotions (tree expr)
1610 If the bitfield has an enumerated type, it is treated as any
1611 other value of that type for promotion purposes. */
1612 type = is_bitfield_expr_with_lowered_type (expr);
1613 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1614 type = TREE_TYPE (expr);
1615 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1616 promoted_type = type_promotes_to (type);
1617 if (type != promoted_type)
1618 expr = cp_convert (promoted_type, expr);
1622 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1626 inline_conversion (tree exp)
1628 if (TREE_CODE (exp) == FUNCTION_DECL)
1629 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1634 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1635 decay_conversion to one. */
1638 string_conv_p (tree totype, tree exp, int warn)
1642 if (TREE_CODE (totype) != POINTER_TYPE)
1645 t = TREE_TYPE (totype);
1646 if (!same_type_p (t, char_type_node)
1647 && !same_type_p (t, wchar_type_node))
1650 if (TREE_CODE (exp) == STRING_CST)
1652 /* Make sure that we don't try to convert between char and wchar_t. */
1653 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1658 /* Is this a string constant which has decayed to 'const char *'? */
1659 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1660 if (!same_type_p (TREE_TYPE (exp), t))
1663 if (TREE_CODE (exp) != ADDR_EXPR
1664 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1668 /* This warning is not very useful, as it complains about printf. */
1670 warning (OPT_Wwrite_strings,
1671 "deprecated conversion from string constant to %qT",
1677 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1678 can, for example, use as an lvalue. This code used to be in
1679 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1680 expressions, where we're dealing with aggregates. But now it's again only
1681 called from unary_complex_lvalue. The case (in particular) that led to
1682 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1686 rationalize_conditional_expr (enum tree_code code, tree t)
1688 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1689 the first operand is always the one to be used if both operands
1690 are equal, so we know what conditional expression this used to be. */
1691 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1693 /* The following code is incorrect if either operand side-effects. */
1694 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1695 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1697 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1698 ? LE_EXPR : GE_EXPR),
1699 TREE_OPERAND (t, 0),
1700 TREE_OPERAND (t, 1),
1701 /*overloaded_p=*/NULL),
1702 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1703 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1707 build_conditional_expr (TREE_OPERAND (t, 0),
1708 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1709 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1712 /* Given the TYPE of an anonymous union field inside T, return the
1713 FIELD_DECL for the field. If not found return NULL_TREE. Because
1714 anonymous unions can nest, we must also search all anonymous unions
1715 that are directly reachable. */
1718 lookup_anon_field (tree t, tree type)
1722 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1724 if (TREE_STATIC (field))
1726 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1729 /* If we find it directly, return the field. */
1730 if (DECL_NAME (field) == NULL_TREE
1731 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1736 /* Otherwise, it could be nested, search harder. */
1737 if (DECL_NAME (field) == NULL_TREE
1738 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1740 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1748 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1749 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1750 non-NULL, it indicates the path to the base used to name MEMBER.
1751 If PRESERVE_REFERENCE is true, the expression returned will have
1752 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1753 returned will have the type referred to by the reference.
1755 This function does not perform access control; that is either done
1756 earlier by the parser when the name of MEMBER is resolved to MEMBER
1757 itself, or later when overload resolution selects one of the
1758 functions indicated by MEMBER. */
1761 build_class_member_access_expr (tree object, tree member,
1762 tree access_path, bool preserve_reference)
1766 tree result = NULL_TREE;
1768 if (error_operand_p (object) || error_operand_p (member))
1769 return error_mark_node;
1771 gcc_assert (DECL_P (member) || BASELINK_P (member));
1775 The type of the first expression shall be "class object" (of a
1777 object_type = TREE_TYPE (object);
1778 if (!currently_open_class (object_type)
1779 && !complete_type_or_else (object_type, object))
1780 return error_mark_node;
1781 if (!CLASS_TYPE_P (object_type))
1783 error ("request for member %qD in %qE, which is of non-class type %qT",
1784 member, object, object_type);
1785 return error_mark_node;
1788 /* The standard does not seem to actually say that MEMBER must be a
1789 member of OBJECT_TYPE. However, that is clearly what is
1791 if (DECL_P (member))
1793 member_scope = DECL_CLASS_CONTEXT (member);
1795 if (TREE_DEPRECATED (member))
1796 warn_deprecated_use (member);
1799 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1800 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1801 presently be the anonymous union. Go outwards until we find a
1802 type related to OBJECT_TYPE. */
1803 while (ANON_AGGR_TYPE_P (member_scope)
1804 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1806 member_scope = TYPE_CONTEXT (member_scope);
1807 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1809 if (TREE_CODE (member) == FIELD_DECL)
1810 error ("invalid use of nonstatic data member %qE", member);
1812 error ("%qD is not a member of %qT", member, object_type);
1813 return error_mark_node;
1816 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1817 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1818 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1820 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1822 object = build_indirect_ref (temp, NULL);
1825 /* In [expr.ref], there is an explicit list of the valid choices for
1826 MEMBER. We check for each of those cases here. */
1827 if (TREE_CODE (member) == VAR_DECL)
1829 /* A static data member. */
1831 /* If OBJECT has side-effects, they are supposed to occur. */
1832 if (TREE_SIDE_EFFECTS (object))
1833 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1835 else if (TREE_CODE (member) == FIELD_DECL)
1837 /* A non-static data member. */
1842 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1843 && integer_zerop (TREE_OPERAND (object, 0)));
1845 /* Convert OBJECT to the type of MEMBER. */
1846 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1847 TYPE_MAIN_VARIANT (member_scope)))
1852 binfo = lookup_base (access_path ? access_path : object_type,
1853 member_scope, ba_unique, &kind);
1854 if (binfo == error_mark_node)
1855 return error_mark_node;
1857 /* It is invalid to try to get to a virtual base of a
1858 NULL object. The most common cause is invalid use of
1860 if (null_object_p && kind == bk_via_virtual)
1862 error ("invalid access to non-static data member %qD of "
1865 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1866 return error_mark_node;
1869 /* Convert to the base. */
1870 object = build_base_path (PLUS_EXPR, object, binfo,
1872 /* If we found the base successfully then we should be able
1873 to convert to it successfully. */
1874 gcc_assert (object != error_mark_node);
1877 /* Complain about other invalid uses of offsetof, even though they will
1878 give the right answer. Note that we complain whether or not they
1879 actually used the offsetof macro, since there's no way to know at this
1880 point. So we just give a warning, instead of a pedwarn. */
1881 /* Do not produce this warning for base class field references, because
1882 we know for a fact that didn't come from offsetof. This does occur
1883 in various testsuite cases where a null object is passed where a
1884 vtable access is required. */
1885 if (null_object_p && warn_invalid_offsetof
1886 && CLASSTYPE_NON_POD_P (object_type)
1887 && !DECL_FIELD_IS_BASE (member)
1888 && !skip_evaluation)
1890 warning (0, "invalid access to non-static data member %qD of NULL object",
1892 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1895 /* If MEMBER is from an anonymous aggregate, we have converted
1896 OBJECT so that it refers to the class containing the
1897 anonymous union. Generate a reference to the anonymous union
1898 itself, and recur to find MEMBER. */
1899 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1900 /* When this code is called from build_field_call, the
1901 object already has the type of the anonymous union.
1902 That is because the COMPONENT_REF was already
1903 constructed, and was then disassembled before calling
1904 build_field_call. After the function-call code is
1905 cleaned up, this waste can be eliminated. */
1906 && (!same_type_ignoring_top_level_qualifiers_p
1907 (TREE_TYPE (object), DECL_CONTEXT (member))))
1909 tree anonymous_union;
1911 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1912 DECL_CONTEXT (member));
1913 object = build_class_member_access_expr (object,
1915 /*access_path=*/NULL_TREE,
1916 preserve_reference);
1919 /* Compute the type of the field, as described in [expr.ref]. */
1920 type_quals = TYPE_UNQUALIFIED;
1921 member_type = TREE_TYPE (member);
1922 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1924 type_quals = (cp_type_quals (member_type)
1925 | cp_type_quals (object_type));
1927 /* A field is const (volatile) if the enclosing object, or the
1928 field itself, is const (volatile). But, a mutable field is
1929 not const, even within a const object. */
1930 if (DECL_MUTABLE_P (member))
1931 type_quals &= ~TYPE_QUAL_CONST;
1932 member_type = cp_build_qualified_type (member_type, type_quals);
1935 result = build3 (COMPONENT_REF, member_type, object, member,
1937 result = fold_if_not_in_template (result);
1939 /* Mark the expression const or volatile, as appropriate. Even
1940 though we've dealt with the type above, we still have to mark the
1941 expression itself. */
1942 if (type_quals & TYPE_QUAL_CONST)
1943 TREE_READONLY (result) = 1;
1944 if (type_quals & TYPE_QUAL_VOLATILE)
1945 TREE_THIS_VOLATILE (result) = 1;
1947 else if (BASELINK_P (member))
1949 /* The member is a (possibly overloaded) member function. */
1953 /* If the MEMBER is exactly one static member function, then we
1954 know the type of the expression. Otherwise, we must wait
1955 until overload resolution has been performed. */
1956 functions = BASELINK_FUNCTIONS (member);
1957 if (TREE_CODE (functions) == FUNCTION_DECL
1958 && DECL_STATIC_FUNCTION_P (functions))
1959 type = TREE_TYPE (functions);
1961 type = unknown_type_node;
1962 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1963 base. That will happen when the function is called. */
1964 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1966 else if (TREE_CODE (member) == CONST_DECL)
1968 /* The member is an enumerator. */
1970 /* If OBJECT has side-effects, they are supposed to occur. */
1971 if (TREE_SIDE_EFFECTS (object))
1972 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1977 error ("invalid use of %qD", member);
1978 return error_mark_node;
1981 if (!preserve_reference)
1984 If E2 is declared to have type "reference to T", then ... the
1985 type of E1.E2 is T. */
1986 result = convert_from_reference (result);
1991 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1992 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1995 lookup_destructor (tree object, tree scope, tree dtor_name)
1997 tree object_type = TREE_TYPE (object);
1998 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2001 if (scope && !check_dtor_name (scope, dtor_type))
2003 error ("qualified type %qT does not match destructor name ~%qT",
2005 return error_mark_node;
2007 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2009 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2010 TYPE_MAIN_VARIANT (object_type), dtor_type);
2011 return error_mark_node;
2013 expr = lookup_member (dtor_type, complete_dtor_identifier,
2014 /*protect=*/1, /*want_type=*/false);
2015 expr = (adjust_result_of_qualified_name_lookup
2016 (expr, dtor_type, object_type));
2020 /* An expression of the form "A::template B" has been resolved to
2021 DECL. Issue a diagnostic if B is not a template or template
2025 check_template_keyword (tree decl)
2027 /* The standard says:
2031 If a name prefixed by the keyword template is not a member
2032 template, the program is ill-formed.
2034 DR 228 removed the restriction that the template be a member
2037 DR 96, if accepted would add the further restriction that explicit
2038 template arguments must be provided if the template keyword is
2039 used, but, as of 2005-10-16, that DR is still in "drafting". If
2040 this DR is accepted, then the semantic checks here can be
2041 simplified, as the entity named must in fact be a template
2042 specialization, rather than, as at present, a set of overloaded
2043 functions containing at least one template function. */
2044 if (TREE_CODE (decl) != TEMPLATE_DECL
2045 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2047 if (!is_overloaded_fn (decl))
2048 pedwarn ("%qD is not a template", decl);
2053 if (BASELINK_P (fns))
2054 fns = BASELINK_FUNCTIONS (fns);
2057 tree fn = OVL_CURRENT (fns);
2058 if (TREE_CODE (fn) == TEMPLATE_DECL
2059 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2061 if (TREE_CODE (fn) == FUNCTION_DECL
2062 && DECL_USE_TEMPLATE (fn)
2063 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2065 fns = OVL_NEXT (fns);
2068 pedwarn ("%qD is not a template", decl);
2073 /* This function is called by the parser to process a class member
2074 access expression of the form OBJECT.NAME. NAME is a node used by
2075 the parser to represent a name; it is not yet a DECL. It may,
2076 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2077 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2078 there is no reason to do the lookup twice, so the parser keeps the
2079 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2080 be a template via the use of the "A::template B" syntax. */
2083 finish_class_member_access_expr (tree object, tree name, bool template_p)
2088 tree access_path = NULL_TREE;
2089 tree orig_object = object;
2090 tree orig_name = name;
2092 if (object == error_mark_node || name == error_mark_node)
2093 return error_mark_node;
2095 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2096 if (!objc_is_public (object, name))
2097 return error_mark_node;
2099 object_type = TREE_TYPE (object);
2101 if (processing_template_decl)
2103 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2104 dependent_type_p (object_type)
2105 /* If NAME is just an IDENTIFIER_NODE, then the expression
2107 || TREE_CODE (object) == IDENTIFIER_NODE
2108 /* If NAME is "f<args>", where either 'f' or 'args' is
2109 dependent, then the expression is dependent. */
2110 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2111 && dependent_template_id_p (TREE_OPERAND (name, 0),
2112 TREE_OPERAND (name, 1)))
2113 /* If NAME is "T::X" where "T" is dependent, then the
2114 expression is dependent. */
2115 || (TREE_CODE (name) == SCOPE_REF
2116 && TYPE_P (TREE_OPERAND (name, 0))
2117 && dependent_type_p (TREE_OPERAND (name, 0))))
2118 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2119 object = build_non_dependent_expr (object);
2124 The type of the first expression shall be "class object" (of a
2126 if (!currently_open_class (object_type)
2127 && !complete_type_or_else (object_type, object))
2128 return error_mark_node;
2129 if (!CLASS_TYPE_P (object_type))
2131 error ("request for member %qD in %qE, which is of non-class type %qT",
2132 name, object, object_type);
2133 return error_mark_node;
2136 if (BASELINK_P (name))
2137 /* A member function that has already been looked up. */
2141 bool is_template_id = false;
2142 tree template_args = NULL_TREE;
2145 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2147 is_template_id = true;
2148 template_args = TREE_OPERAND (name, 1);
2149 name = TREE_OPERAND (name, 0);
2151 if (TREE_CODE (name) == OVERLOAD)
2152 name = DECL_NAME (get_first_fn (name));
2153 else if (DECL_P (name))
2154 name = DECL_NAME (name);
2157 if (TREE_CODE (name) == SCOPE_REF)
2159 /* A qualified name. The qualifying class or namespace `S'
2160 has already been looked up; it is either a TYPE or a
2162 scope = TREE_OPERAND (name, 0);
2163 name = TREE_OPERAND (name, 1);
2165 /* If SCOPE is a namespace, then the qualified name does not
2166 name a member of OBJECT_TYPE. */
2167 if (TREE_CODE (scope) == NAMESPACE_DECL)
2169 error ("%<%D::%D%> is not a member of %qT",
2170 scope, name, object_type);
2171 return error_mark_node;
2174 gcc_assert (CLASS_TYPE_P (scope));
2175 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2176 || TREE_CODE (name) == BIT_NOT_EXPR);
2178 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2179 access_path = lookup_base (object_type, scope, ba_check, NULL);
2180 if (access_path == error_mark_node)
2181 return error_mark_node;
2184 error ("%qT is not a base of %qT", scope, object_type);
2185 return error_mark_node;
2191 access_path = object_type;
2194 if (TREE_CODE (name) == BIT_NOT_EXPR)
2195 member = lookup_destructor (object, scope, name);
2198 /* Look up the member. */
2199 member = lookup_member (access_path, name, /*protect=*/1,
2200 /*want_type=*/false);
2201 if (member == NULL_TREE)
2203 error ("%qD has no member named %qE", object_type, name);
2204 return error_mark_node;
2206 if (member == error_mark_node)
2207 return error_mark_node;
2212 tree template = member;
2214 if (BASELINK_P (template))
2215 template = lookup_template_function (template, template_args);
2218 error ("%qD is not a member template function", name);
2219 return error_mark_node;
2224 if (TREE_DEPRECATED (member))
2225 warn_deprecated_use (member);
2228 check_template_keyword (member);
2230 expr = build_class_member_access_expr (object, member, access_path,
2231 /*preserve_reference=*/false);
2232 if (processing_template_decl && expr != error_mark_node)
2234 if (BASELINK_P (member))
2236 if (TREE_CODE (orig_name) == SCOPE_REF)
2237 BASELINK_QUALIFIED_P (member) = 1;
2240 return build_min_non_dep (COMPONENT_REF, expr,
2241 orig_object, orig_name,
2248 /* Return an expression for the MEMBER_NAME field in the internal
2249 representation of PTRMEM, a pointer-to-member function. (Each
2250 pointer-to-member function type gets its own RECORD_TYPE so it is
2251 more convenient to access the fields by name than by FIELD_DECL.)
2252 This routine converts the NAME to a FIELD_DECL and then creates the
2253 node for the complete expression. */
2256 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2262 /* This code is a stripped down version of
2263 build_class_member_access_expr. It does not work to use that
2264 routine directly because it expects the object to be of class
2266 ptrmem_type = TREE_TYPE (ptrmem);
2267 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2268 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2269 /*want_type=*/false);
2270 member_type = cp_build_qualified_type (TREE_TYPE (member),
2271 cp_type_quals (ptrmem_type));
2272 return fold_build3 (COMPONENT_REF, member_type,
2273 ptrmem, member, NULL_TREE);
2276 /* Given an expression PTR for a pointer, return an expression
2277 for the value pointed to.
2278 ERRORSTRING is the name of the operator to appear in error messages.
2280 This function may need to overload OPERATOR_FNNAME.
2281 Must also handle REFERENCE_TYPEs for C++. */
2284 build_x_indirect_ref (tree expr, const char *errorstring)
2286 tree orig_expr = expr;
2289 if (processing_template_decl)
2291 if (type_dependent_expression_p (expr))
2292 return build_min_nt (INDIRECT_REF, expr);
2293 expr = build_non_dependent_expr (expr);
2296 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2297 NULL_TREE, /*overloaded_p=*/NULL);
2299 rval = build_indirect_ref (expr, errorstring);
2301 if (processing_template_decl && rval != error_mark_node)
2302 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2308 build_indirect_ref (tree ptr, const char *errorstring)
2312 if (ptr == error_mark_node)
2313 return error_mark_node;
2315 if (ptr == current_class_ptr)
2316 return current_class_ref;
2318 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2319 ? ptr : decay_conversion (ptr));
2320 type = TREE_TYPE (pointer);
2322 if (POINTER_TYPE_P (type))
2326 If the type of the expression is "pointer to T," the type
2327 of the result is "T."
2329 We must use the canonical variant because certain parts of
2330 the back end, like fold, do pointer comparisons between
2332 tree t = canonical_type_variant (TREE_TYPE (type));
2334 if (VOID_TYPE_P (t))
2336 /* A pointer to incomplete type (other than cv void) can be
2337 dereferenced [expr.unary.op]/1 */
2338 error ("%qT is not a pointer-to-object type", type);
2339 return error_mark_node;
2341 else if (TREE_CODE (pointer) == ADDR_EXPR
2342 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2343 /* The POINTER was something like `&x'. We simplify `*&x' to
2345 return TREE_OPERAND (pointer, 0);
2348 tree ref = build1 (INDIRECT_REF, t, pointer);
2350 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2351 so that we get the proper error message if the result is used
2352 to assign to. Also, &* is supposed to be a no-op. */
2353 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2354 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2355 TREE_SIDE_EFFECTS (ref)
2356 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2360 /* `pointer' won't be an error_mark_node if we were given a
2361 pointer to member, so it's cool to check for this here. */
2362 else if (TYPE_PTR_TO_MEMBER_P (type))
2363 error ("invalid use of %qs on pointer to member", errorstring);
2364 else if (pointer != error_mark_node)
2367 error ("invalid type argument of %qs", errorstring);
2369 error ("invalid type argument");
2371 return error_mark_node;
2374 /* This handles expressions of the form "a[i]", which denotes
2377 This is logically equivalent in C to *(a+i), but we may do it differently.
2378 If A is a variable or a member, we generate a primitive ARRAY_REF.
2379 This avoids forcing the array out of registers, and can work on
2380 arrays that are not lvalues (for example, members of structures returned
2383 If INDEX is of some user-defined type, it must be converted to
2384 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2385 will inherit the type of the array, which will be some pointer type. */
2388 build_array_ref (tree array, tree idx)
2392 error ("subscript missing in array reference");
2393 return error_mark_node;
2396 if (TREE_TYPE (array) == error_mark_node
2397 || TREE_TYPE (idx) == error_mark_node)
2398 return error_mark_node;
2400 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2402 switch (TREE_CODE (array))
2406 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2407 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2408 TREE_OPERAND (array, 0), value);
2412 return build_conditional_expr
2413 (TREE_OPERAND (array, 0),
2414 build_array_ref (TREE_OPERAND (array, 1), idx),
2415 build_array_ref (TREE_OPERAND (array, 2), idx));
2421 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2425 warn_array_subscript_with_type_char (idx);
2427 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2429 error ("array subscript is not an integer");
2430 return error_mark_node;
2433 /* Apply integral promotions *after* noticing character types.
2434 (It is unclear why we do these promotions -- the standard
2435 does not say that we should. In fact, the natural thing would
2436 seem to be to convert IDX to ptrdiff_t; we're performing
2437 pointer arithmetic.) */
2438 idx = perform_integral_promotions (idx);
2440 /* An array that is indexed by a non-constant
2441 cannot be stored in a register; we must be able to do
2442 address arithmetic on its address.
2443 Likewise an array of elements of variable size. */
2444 if (TREE_CODE (idx) != INTEGER_CST
2445 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2446 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2449 if (!cxx_mark_addressable (array))
2450 return error_mark_node;
2453 /* An array that is indexed by a constant value which is not within
2454 the array bounds cannot be stored in a register either; because we
2455 would get a crash in store_bit_field/extract_bit_field when trying
2456 to access a non-existent part of the register. */
2457 if (TREE_CODE (idx) == INTEGER_CST
2458 && TYPE_DOMAIN (TREE_TYPE (array))
2459 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2461 if (!cxx_mark_addressable (array))
2462 return error_mark_node;
2465 if (pedantic && !lvalue_p (array))
2466 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2468 /* Note in C++ it is valid to subscript a `register' array, since
2469 it is valid to take the address of something with that
2470 storage specification. */
2474 while (TREE_CODE (foo) == COMPONENT_REF)
2475 foo = TREE_OPERAND (foo, 0);
2476 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2477 warning (OPT_Wextra, "subscripting array declared %<register%>");
2480 type = TREE_TYPE (TREE_TYPE (array));
2481 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2482 /* Array ref is const/volatile if the array elements are
2483 or if the array is.. */
2484 TREE_READONLY (rval)
2485 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2486 TREE_SIDE_EFFECTS (rval)
2487 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2488 TREE_THIS_VOLATILE (rval)
2489 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2490 return require_complete_type (fold_if_not_in_template (rval));
2494 tree ar = default_conversion (array);
2495 tree ind = default_conversion (idx);
2497 /* Put the integer in IND to simplify error checking. */
2498 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2505 if (ar == error_mark_node)
2508 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2510 error ("subscripted value is neither array nor pointer");
2511 return error_mark_node;
2513 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2515 error ("array subscript is not an integer");
2516 return error_mark_node;
2519 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2524 /* Resolve a pointer to member function. INSTANCE is the object
2525 instance to use, if the member points to a virtual member.
2527 This used to avoid checking for virtual functions if basetype
2528 has no virtual functions, according to an earlier ANSI draft.
2529 With the final ISO C++ rules, such an optimization is
2530 incorrect: A pointer to a derived member can be static_cast
2531 to pointer-to-base-member, as long as the dynamic object
2532 later has the right member. */
2535 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2537 if (TREE_CODE (function) == OFFSET_REF)
2538 function = TREE_OPERAND (function, 1);
2540 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2542 tree idx, delta, e1, e2, e3, vtbl, basetype;
2543 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2545 tree instance_ptr = *instance_ptrptr;
2546 tree instance_save_expr = 0;
2547 if (instance_ptr == error_mark_node)
2549 if (TREE_CODE (function) == PTRMEM_CST)
2551 /* Extracting the function address from a pmf is only
2552 allowed with -Wno-pmf-conversions. It only works for
2554 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2555 e1 = convert (fntype, e1);
2560 error ("object missing in use of %qE", function);
2561 return error_mark_node;
2565 if (TREE_SIDE_EFFECTS (instance_ptr))
2566 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2568 if (TREE_SIDE_EFFECTS (function))
2569 function = save_expr (function);
2571 /* Start by extracting all the information from the PMF itself. */
2572 e3 = pfn_from_ptrmemfunc (function);
2573 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2574 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2575 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2577 case ptrmemfunc_vbit_in_pfn:
2578 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2579 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2582 case ptrmemfunc_vbit_in_delta:
2583 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2584 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2591 /* Convert down to the right base before using the instance. A
2592 special case is that in a pointer to member of class C, C may
2593 be incomplete. In that case, the function will of course be
2594 a member of C, and no conversion is required. In fact,
2595 lookup_base will fail in that case, because incomplete
2596 classes do not have BINFOs. */
2597 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2598 if (!same_type_ignoring_top_level_qualifiers_p
2599 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2601 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2602 basetype, ba_check, NULL);
2603 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2605 if (instance_ptr == error_mark_node)
2606 return error_mark_node;
2608 /* ...and then the delta in the PMF. */
2609 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2610 instance_ptr, delta);
2612 /* Hand back the adjusted 'this' argument to our caller. */
2613 *instance_ptrptr = instance_ptr;
2615 /* Next extract the vtable pointer from the object. */
2616 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2618 vtbl = build_indirect_ref (vtbl, NULL);
2620 /* Finally, extract the function pointer from the vtable. */
2621 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2622 e2 = build_indirect_ref (e2, NULL);
2623 TREE_CONSTANT (e2) = 1;
2624 TREE_INVARIANT (e2) = 1;
2626 /* When using function descriptors, the address of the
2627 vtable entry is treated as a function pointer. */
2628 if (TARGET_VTABLE_USES_DESCRIPTORS)
2629 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2630 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2632 TREE_TYPE (e2) = TREE_TYPE (e3);
2633 e1 = build_conditional_expr (e1, e2, e3);
2635 /* Make sure this doesn't get evaluated first inside one of the
2636 branches of the COND_EXPR. */
2637 if (instance_save_expr)
2638 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2639 instance_save_expr, e1);
2647 build_function_call (tree function, tree params)
2649 tree fntype, fndecl;
2650 tree coerced_params;
2651 tree name = NULL_TREE;
2653 tree original = function;
2655 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2656 expressions, like those used for ObjC messenger dispatches. */
2657 function = objc_rewrite_function_call (function, params);
2659 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2660 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2661 if (TREE_CODE (function) == NOP_EXPR
2662 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2663 function = TREE_OPERAND (function, 0);
2665 if (TREE_CODE (function) == FUNCTION_DECL)
2667 name = DECL_NAME (function);
2669 mark_used (function);
2672 /* Convert anything with function type to a pointer-to-function. */
2673 if (pedantic && DECL_MAIN_P (function))
2674 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2676 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2677 (because calling an inline function does not mean the function
2678 needs to be separately compiled). */
2680 if (DECL_INLINE (function))
2681 function = inline_conversion (function);
2683 function = build_addr_func (function);
2689 function = build_addr_func (function);
2692 if (function == error_mark_node)
2693 return error_mark_node;
2695 fntype = TREE_TYPE (function);
2697 if (TYPE_PTRMEMFUNC_P (fntype))
2699 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2700 "function in %<%E (...)%>",
2702 return error_mark_node;
2705 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2706 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2708 if (!((TREE_CODE (fntype) == POINTER_TYPE
2709 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2711 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2713 error ("%qE cannot be used as a function", original);
2714 return error_mark_node;
2717 /* fntype now gets the type of function pointed to. */
2718 fntype = TREE_TYPE (fntype);
2720 /* Convert the parameters to the types declared in the
2721 function prototype, or apply default promotions. */
2723 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2724 params, fndecl, LOOKUP_NORMAL);
2725 if (coerced_params == error_mark_node)
2726 return error_mark_node;
2728 /* Check for errors in format strings and inappropriately
2731 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2732 TYPE_ARG_TYPES (fntype));
2734 return build_cxx_call (function, coerced_params);
2737 /* Convert the actual parameter expressions in the list VALUES
2738 to the types in the list TYPELIST.
2739 If parmdecls is exhausted, or when an element has NULL as its type,
2740 perform the default conversions.
2742 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2744 This is also where warnings about wrong number of args are generated.
2746 Return a list of expressions for the parameters as converted.
2748 Both VALUES and the returned value are chains of TREE_LIST nodes
2749 with the elements of the list in the TREE_VALUE slots of those nodes.
2751 In C++, unspecified trailing parameters can be filled in with their
2752 default arguments, if such were specified. Do so here. */
2755 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2757 tree typetail, valtail;
2758 tree result = NULL_TREE;
2759 const char *called_thing = 0;
2762 /* Argument passing is always copy-initialization. */
2763 flags |= LOOKUP_ONLYCONVERTING;
2767 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2769 if (DECL_NAME (fndecl) == NULL_TREE
2770 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2771 called_thing = "constructor";
2773 called_thing = "member function";
2776 called_thing = "function";
2779 for (valtail = values, typetail = typelist;
2781 valtail = TREE_CHAIN (valtail), i++)
2783 tree type = typetail ? TREE_VALUE (typetail) : 0;
2784 tree val = TREE_VALUE (valtail);
2786 if (val == error_mark_node || type == error_mark_node)
2787 return error_mark_node;
2789 if (type == void_type_node)
2793 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2794 error ("at this point in file");
2797 error ("too many arguments to function");
2798 /* In case anybody wants to know if this argument
2801 TREE_TYPE (tree_last (result)) = error_mark_node;
2805 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2806 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2807 if (TREE_CODE (val) == NOP_EXPR
2808 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2809 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2810 val = TREE_OPERAND (val, 0);
2812 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2814 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2815 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2816 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2817 val = decay_conversion (val);
2820 if (val == error_mark_node)
2821 return error_mark_node;
2825 /* Formal parm type is specified by a function prototype. */
2828 if (!COMPLETE_TYPE_P (complete_type (type)))
2831 error ("parameter %P of %qD has incomplete type %qT",
2834 error ("parameter %P has incomplete type %qT", i, type);
2835 parmval = error_mark_node;
2839 parmval = convert_for_initialization
2840 (NULL_TREE, type, val, flags,
2841 "argument passing", fndecl, i);
2842 parmval = convert_for_arg_passing (type, parmval);
2845 if (parmval == error_mark_node)
2846 return error_mark_node;
2848 result = tree_cons (NULL_TREE, parmval, result);
2852 if (fndecl && DECL_BUILT_IN (fndecl)
2853 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2854 /* Don't do ellipsis conversion for __built_in_constant_p
2855 as this will result in spurious warnings for non-POD
2857 val = require_complete_type (val);
2859 val = convert_arg_to_ellipsis (val);
2861 result = tree_cons (NULL_TREE, val, result);
2865 typetail = TREE_CHAIN (typetail);
2868 if (typetail != 0 && typetail != void_list_node)
2870 /* See if there are default arguments that can be used. */
2871 if (TREE_PURPOSE (typetail)
2872 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2874 for (; typetail != void_list_node; ++i)
2877 = convert_default_arg (TREE_VALUE (typetail),
2878 TREE_PURPOSE (typetail),
2881 if (parmval == error_mark_node)
2882 return error_mark_node;
2884 result = tree_cons (0, parmval, result);
2885 typetail = TREE_CHAIN (typetail);
2886 /* ends with `...'. */
2887 if (typetail == NULL_TREE)
2895 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2896 error ("at this point in file");
2899 error ("too few arguments to function");
2900 return error_mark_node;
2904 return nreverse (result);
2907 /* Build a binary-operation expression, after performing default
2908 conversions on the operands. CODE is the kind of expression to build. */
2911 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2921 if (processing_template_decl)
2923 if (type_dependent_expression_p (arg1)
2924 || type_dependent_expression_p (arg2))
2925 return build_min_nt (code, arg1, arg2);
2926 arg1 = build_non_dependent_expr (arg1);
2927 arg2 = build_non_dependent_expr (arg2);
2930 if (code == DOTSTAR_EXPR)
2931 expr = build_m_component_ref (arg1, arg2);
2933 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2936 if (processing_template_decl && expr != error_mark_node)
2937 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2942 /* Build a binary-operation expression without default conversions.
2943 CODE is the kind of expression to build.
2944 This function differs from `build' in several ways:
2945 the data type of the result is computed and recorded in it,
2946 warnings are generated if arg data types are invalid,
2947 special handling for addition and subtraction of pointers is known,
2948 and some optimization is done (operations on narrow ints
2949 are done in the narrower type when that gives the same result).
2950 Constant folding is also done before the result is returned.
2952 Note that the operands will never have enumeral types
2953 because either they have just had the default conversions performed
2954 or they have both just been converted to some other type in which
2955 the arithmetic is to be done.
2957 C++: must do special pointer arithmetic when implementing
2958 multiple inheritance, and deal with pointer to member functions. */
2961 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2962 int convert_p ATTRIBUTE_UNUSED)
2965 enum tree_code code0, code1;
2967 const char *invalid_op_diag;
2969 /* Expression code to give to the expression when it is built.
2970 Normally this is CODE, which is what the caller asked for,
2971 but in some special cases we change it. */
2972 enum tree_code resultcode = code;
2974 /* Data type in which the computation is to be performed.
2975 In the simplest cases this is the common type of the arguments. */
2976 tree result_type = NULL;
2978 /* Nonzero means operands have already been type-converted
2979 in whatever way is necessary.
2980 Zero means they need to be converted to RESULT_TYPE. */
2983 /* Nonzero means create the expression with this type, rather than
2985 tree build_type = 0;
2987 /* Nonzero means after finally constructing the expression
2988 convert it to this type. */
2989 tree final_type = 0;
2993 /* Nonzero if this is an operation like MIN or MAX which can
2994 safely be computed in short if both args are promoted shorts.
2995 Also implies COMMON.
2996 -1 indicates a bitwise operation; this makes a difference
2997 in the exact conditions for when it is safe to do the operation
2998 in a narrower mode. */
3001 /* Nonzero if this is a comparison operation;
3002 if both args are promoted shorts, compare the original shorts.
3003 Also implies COMMON. */
3004 int short_compare = 0;
3006 /* Nonzero if this is a right-shift operation, which can be computed on the
3007 original short and then promoted if the operand is a promoted short. */
3008 int short_shift = 0;
3010 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3013 /* True if both operands have arithmetic type. */
3014 bool arithmetic_types_p;
3016 /* Apply default conversions. */
3020 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3021 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3022 || code == TRUTH_XOR_EXPR)
3024 if (!really_overloaded_fn (op0))
3025 op0 = decay_conversion (op0);
3026 if (!really_overloaded_fn (op1))
3027 op1 = decay_conversion (op1);
3031 if (!really_overloaded_fn (op0))
3032 op0 = default_conversion (op0);
3033 if (!really_overloaded_fn (op1))
3034 op1 = default_conversion (op1);
3037 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3038 STRIP_TYPE_NOPS (op0);
3039 STRIP_TYPE_NOPS (op1);
3041 /* DTRT if one side is an overloaded function, but complain about it. */
3042 if (type_unknown_p (op0))
3044 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3045 if (t != error_mark_node)
3047 pedwarn ("assuming cast to type %qT from overloaded function",
3052 if (type_unknown_p (op1))
3054 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3055 if (t != error_mark_node)
3057 pedwarn ("assuming cast to type %qT from overloaded function",
3063 type0 = TREE_TYPE (op0);
3064 type1 = TREE_TYPE (op1);
3066 /* The expression codes of the data types of the arguments tell us
3067 whether the arguments are integers, floating, pointers, etc. */
3068 code0 = TREE_CODE (type0);
3069 code1 = TREE_CODE (type1);
3071 /* If an error was already reported for one of the arguments,
3072 avoid reporting another error. */
3074 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3075 return error_mark_node;
3077 if ((invalid_op_diag
3078 = targetm.invalid_binary_op (code, type0, type1)))
3080 error (invalid_op_diag);
3081 return error_mark_node;
3087 /* Subtraction of two similar pointers.
3088 We must subtract them as integers, then divide by object size. */
3089 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3090 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3092 return pointer_diff (op0, op1, common_type (type0, type1));
3093 /* In all other cases except pointer - int, the usual arithmetic
3095 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3100 /* The pointer - int case is just like pointer + int; fall
3103 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3104 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3108 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3109 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3110 if (processing_template_decl)
3112 result_type = TREE_TYPE (ptr_operand);
3115 return cp_pointer_int_sum (code,
3126 case TRUNC_DIV_EXPR:
3128 case FLOOR_DIV_EXPR:
3129 case ROUND_DIV_EXPR:
3130 case EXACT_DIV_EXPR:
3131 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3132 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3133 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3134 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3136 enum tree_code tcode0 = code0, tcode1 = code1;
3138 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3139 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3140 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3141 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3143 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3144 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3145 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3146 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3148 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3149 resultcode = RDIV_EXPR;
3151 /* When dividing two signed integers, we have to promote to int.
3152 unless we divide by a constant != -1. Note that default
3153 conversion will have been performed on the operands at this
3154 point, so we have to dig out the original type to find out if
3156 shorten = ((TREE_CODE (op0) == NOP_EXPR
3157 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3158 || (TREE_CODE (op1) == INTEGER_CST
3159 && ! integer_all_onesp (op1)));
3168 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3169 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3173 case TRUNC_MOD_EXPR:
3174 case FLOOR_MOD_EXPR:
3175 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3176 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3177 else if (code1 == REAL_TYPE && real_zerop (op1))
3178 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3180 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3182 /* Although it would be tempting to shorten always here, that loses
3183 on some targets, since the modulo instruction is undefined if the
3184 quotient can't be represented in the computation mode. We shorten
3185 only if unsigned or if dividing by something we know != -1. */
3186 shorten = ((TREE_CODE (op0) == NOP_EXPR
3187 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3188 || (TREE_CODE (op1) == INTEGER_CST
3189 && ! integer_all_onesp (op1)));
3194 case TRUTH_ANDIF_EXPR:
3195 case TRUTH_ORIF_EXPR:
3196 case TRUTH_AND_EXPR:
3198 result_type = boolean_type_node;
3201 /* Shift operations: result has same type as first operand;
3202 always convert second operand to int.
3203 Also set SHORT_SHIFT if shifting rightward. */
3206 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3208 result_type = type0;
3209 if (TREE_CODE (op1) == INTEGER_CST)
3211 if (tree_int_cst_lt (op1, integer_zero_node))
3212 warning (0, "right shift count is negative");
3215 if (! integer_zerop (op1))
3217 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3218 warning (0, "right shift count >= width of type");
3221 /* Convert the shift-count to an integer, regardless of
3222 size of value being shifted. */
3223 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3224 op1 = cp_convert (integer_type_node, op1);
3225 /* Avoid converting op1 to result_type later. */
3231 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3233 result_type = type0;
3234 if (TREE_CODE (op1) == INTEGER_CST)
3236 if (tree_int_cst_lt (op1, integer_zero_node))
3237 warning (0, "left shift count is negative");
3238 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3239 warning (0, "left shift count >= width of type");
3241 /* Convert the shift-count to an integer, regardless of
3242 size of value being shifted. */
3243 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3244 op1 = cp_convert (integer_type_node, op1);
3245 /* Avoid converting op1 to result_type later. */
3252 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3254 result_type = type0;
3255 if (TREE_CODE (op1) == INTEGER_CST)
3257 if (tree_int_cst_lt (op1, integer_zero_node))
3258 warning (0, "%s rotate count is negative",
3259 (code == LROTATE_EXPR) ? "left" : "right");
3260 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3261 warning (0, "%s rotate count >= width of type",
3262 (code == LROTATE_EXPR) ? "left" : "right");
3264 /* Convert the shift-count to an integer, regardless of
3265 size of value being shifted. */
3266 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3267 op1 = cp_convert (integer_type_node, op1);
3273 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3274 warning (OPT_Wfloat_equal,
3275 "comparing floating point with == or != is unsafe");
3276 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3277 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3278 warning (OPT_Waddress,
3279 "comparison with string literal results in unspecified behaviour");
3281 build_type = boolean_type_node;
3282 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3283 || code0 == COMPLEX_TYPE)
3284 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3285 || code1 == COMPLEX_TYPE))
3287 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3288 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3289 result_type = composite_pointer_type (type0, type1, op0, op1,
3291 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3292 && null_ptr_cst_p (op1))
3293 result_type = type0;
3294 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3295 && null_ptr_cst_p (op0))
3296 result_type = type1;
3297 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3299 result_type = type0;
3300 error ("ISO C++ forbids comparison between pointer and integer");
3302 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3304 result_type = type1;
3305 error ("ISO C++ forbids comparison between pointer and integer");
3307 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3309 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3310 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3311 result_type = TREE_TYPE (op0);
3313 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3314 return cp_build_binary_op (code, op1, op0);
3315 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3316 && same_type_p (type0, type1))
3318 /* E will be the final comparison. */
3320 /* E1 and E2 are for scratch. */
3328 if (TREE_SIDE_EFFECTS (op0))
3329 op0 = save_expr (op0);
3330 if (TREE_SIDE_EFFECTS (op1))
3331 op1 = save_expr (op1);
3336 && (!op0.pfn || op0.delta == op1.delta))
3338 The reason for the `!op0.pfn' bit is that a NULL
3339 pointer-to-member is any member with a zero PFN; the
3340 DELTA field is unspecified. */
3341 pfn0 = pfn_from_ptrmemfunc (op0);
3342 pfn1 = pfn_from_ptrmemfunc (op1);
3343 delta0 = build_ptrmemfunc_access_expr (op0,
3345 delta1 = build_ptrmemfunc_access_expr (op1,
3347 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3348 e2 = cp_build_binary_op (EQ_EXPR,
3350 cp_convert (TREE_TYPE (pfn0),
3351 integer_zero_node));
3352 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3353 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3354 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3355 if (code == EQ_EXPR)
3357 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3361 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3362 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3364 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3365 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3373 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3374 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3376 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3377 result_type = composite_pointer_type (type0, type1, op0, op1,
3385 if (TREE_CODE (orig_op0) == STRING_CST
3386 || TREE_CODE (orig_op1) == STRING_CST)
3387 warning (OPT_Waddress,
3388 "comparison with string literal results in unspecified behaviour");
3390 build_type = boolean_type_node;
3391 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3392 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3394 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3395 result_type = composite_pointer_type (type0, type1, op0, op1,
3397 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3398 && integer_zerop (op1))
3399 result_type = type0;
3400 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3401 && integer_zerop (op0))
3402 result_type = type1;
3403 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3405 result_type = type0;
3406 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3408 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3410 result_type = type1;
3411 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3415 case UNORDERED_EXPR:
3422 build_type = integer_type_node;
3423 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3425 error ("unordered comparison on non-floating point argument");
3426 return error_mark_node;
3435 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3436 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3437 || code1 == COMPLEX_TYPE)))
3438 arithmetic_types_p = 1;
3441 arithmetic_types_p = 0;
3442 /* Vector arithmetic is only allowed when both sides are vectors. */
3443 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3445 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3446 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3449 binary_op_error (code);
3450 return error_mark_node;
3452 arithmetic_types_p = 1;
3455 /* Determine the RESULT_TYPE, if it is not already known. */
3457 && arithmetic_types_p
3458 && (shorten || common || short_compare))
3459 result_type = common_type (type0, type1);
3463 error ("invalid operands of types %qT and %qT to binary %qO",
3464 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3465 return error_mark_node;
3468 /* If we're in a template, the only thing we need to know is the
3470 if (processing_template_decl)
3471 return build2 (resultcode,
3472 build_type ? build_type : result_type,
3475 if (arithmetic_types_p)
3477 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3479 /* For certain operations (which identify themselves by shorten != 0)
3480 if both args were extended from the same smaller type,
3481 do the arithmetic in that type and then extend.
3483 shorten !=0 and !=1 indicates a bitwise operation.
3484 For them, this optimization is safe only if
3485 both args are zero-extended or both are sign-extended.
3486 Otherwise, we might change the result.
3487 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3488 but calculated in (unsigned short) it would be (unsigned short)-1. */
3490 if (shorten && none_complex)
3492 int unsigned0, unsigned1;
3493 tree arg0 = get_narrower (op0, &unsigned0);
3494 tree arg1 = get_narrower (op1, &unsigned1);
3495 /* UNS is 1 if the operation to be done is an unsigned one. */
3496 int uns = TYPE_UNSIGNED (result_type);
3499 final_type = result_type;
3501 /* Handle the case that OP0 does not *contain* a conversion
3502 but it *requires* conversion to FINAL_TYPE. */
3504 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3505 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3506 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3507 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3509 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3511 /* For bitwise operations, signedness of nominal type
3512 does not matter. Consider only how operands were extended. */
3516 /* Note that in all three cases below we refrain from optimizing
3517 an unsigned operation on sign-extended args.
3518 That would not be valid. */
3520 /* Both args variable: if both extended in same way
3521 from same width, do it in that width.
3522 Do it unsigned if args were zero-extended. */
3523 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3524 < TYPE_PRECISION (result_type))
3525 && (TYPE_PRECISION (TREE_TYPE (arg1))
3526 == TYPE_PRECISION (TREE_TYPE (arg0)))
3527 && unsigned0 == unsigned1
3528 && (unsigned0 || !uns))
3529 result_type = c_common_signed_or_unsigned_type
3530 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3531 else if (TREE_CODE (arg0) == INTEGER_CST
3532 && (unsigned1 || !uns)
3533 && (TYPE_PRECISION (TREE_TYPE (arg1))
3534 < TYPE_PRECISION (result_type))
3535 && (type = c_common_signed_or_unsigned_type
3536 (unsigned1, TREE_TYPE (arg1)),
3537 int_fits_type_p (arg0, type)))
3539 else if (TREE_CODE (arg1) == INTEGER_CST
3540 && (unsigned0 || !uns)
3541 && (TYPE_PRECISION (TREE_TYPE (arg0))
3542 < TYPE_PRECISION (result_type))
3543 && (type = c_common_signed_or_unsigned_type
3544 (unsigned0, TREE_TYPE (arg0)),
3545 int_fits_type_p (arg1, type)))
3549 /* Shifts can be shortened if shifting right. */
3554 tree arg0 = get_narrower (op0, &unsigned_arg);
3556 final_type = result_type;
3558 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3559 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3561 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3562 /* We can shorten only if the shift count is less than the
3563 number of bits in the smaller type size. */
3564 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3565 /* If arg is sign-extended and then unsigned-shifted,
3566 we can simulate this with a signed shift in arg's type
3567 only if the extended result is at least twice as wide
3568 as the arg. Otherwise, the shift could use up all the
3569 ones made by sign-extension and bring in zeros.
3570 We can't optimize that case at all, but in most machines
3571 it never happens because available widths are 2**N. */
3572 && (!TYPE_UNSIGNED (final_type)
3574 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3575 <= TYPE_PRECISION (result_type))))
3577 /* Do an unsigned shift if the operand was zero-extended. */
3579 = c_common_signed_or_unsigned_type (unsigned_arg,
3581 /* Convert value-to-be-shifted to that type. */
3582 if (TREE_TYPE (op0) != result_type)
3583 op0 = cp_convert (result_type, op0);
3588 /* Comparison operations are shortened too but differently.
3589 They identify themselves by setting short_compare = 1. */
3593 /* Don't write &op0, etc., because that would prevent op0
3594 from being kept in a register.
3595 Instead, make copies of the our local variables and
3596 pass the copies by reference, then copy them back afterward. */
3597 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3598 enum tree_code xresultcode = resultcode;
3600 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3602 return cp_convert (boolean_type_node, val);
3603 op0 = xop0, op1 = xop1;
3605 resultcode = xresultcode;
3608 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3609 && warn_sign_compare
3610 /* Do not warn until the template is instantiated; we cannot
3611 bound the ranges of the arguments until that point. */
3612 && !processing_template_decl)
3614 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3615 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3617 int unsignedp0, unsignedp1;
3618 tree primop0 = get_narrower (op0, &unsignedp0);
3619 tree primop1 = get_narrower (op1, &unsignedp1);
3621 /* Check for comparison of different enum types. */
3622 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3623 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3624 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3625 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3627 warning (0, "comparison between types %q#T and %q#T",
3628 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3631 /* Give warnings for comparisons between signed and unsigned
3632 quantities that may fail. */
3633 /* Do the checking based on the original operand trees, so that
3634 casts will be considered, but default promotions won't be. */
3636 /* Do not warn if the comparison is being done in a signed type,
3637 since the signed type will only be chosen if it can represent
3638 all the values of the unsigned type. */
3639 if (!TYPE_UNSIGNED (result_type))
3641 /* Do not warn if both operands are unsigned. */
3642 else if (op0_signed == op1_signed)
3644 /* Do not warn if the signed quantity is an unsuffixed
3645 integer literal (or some static constant expression
3646 involving such literals or a conditional expression
3647 involving such literals) and it is non-negative. */
3648 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3649 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3651 /* Do not warn if the comparison is an equality operation,
3652 the unsigned quantity is an integral constant and it does
3653 not use the most significant bit of result_type. */
3654 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3655 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3656 && int_fits_type_p (orig_op1, c_common_signed_type
3658 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3659 && int_fits_type_p (orig_op0, c_common_signed_type
3663 warning (0, "comparison between signed and unsigned integer expressions");
3665 /* Warn if two unsigned values are being compared in a size
3666 larger than their original size, and one (and only one) is the
3667 result of a `~' operator. This comparison will always fail.
3669 Also warn if one operand is a constant, and the constant does not
3670 have all bits set that are set in the ~ operand when it is
3673 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3674 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3676 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3677 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3678 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3679 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3681 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3684 HOST_WIDE_INT constant, mask;
3688 if (host_integerp (primop0, 0))
3691 unsignedp = unsignedp1;
3692 constant = tree_low_cst (primop0, 0);
3697 unsignedp = unsignedp0;
3698 constant = tree_low_cst (primop1, 0);
3701 bits = TYPE_PRECISION (TREE_TYPE (primop));
3702 if (bits < TYPE_PRECISION (result_type)
3703 && bits < HOST_BITS_PER_LONG && unsignedp)
3705 mask = (~ (HOST_WIDE_INT) 0) << bits;
3706 if ((mask & constant) != mask)
3707 warning (0, "comparison of promoted ~unsigned with constant");
3710 else if (unsignedp0 && unsignedp1
3711 && (TYPE_PRECISION (TREE_TYPE (primop0))
3712 < TYPE_PRECISION (result_type))
3713 && (TYPE_PRECISION (TREE_TYPE (primop1))
3714 < TYPE_PRECISION (result_type)))
3715 warning (0, "comparison of promoted ~unsigned with unsigned");
3720 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3721 Then the expression will be built.
3722 It will be given type FINAL_TYPE if that is nonzero;
3723 otherwise, it will be given type RESULT_TYPE. */
3725 /* Issue warnings about peculiar, but valid, uses of NULL. */
3726 if (/* It's reasonable to use pointer values as operands of &&
3727 and ||, so NULL is no exception. */
3728 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3729 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3730 (orig_op0 == null_node
3731 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3732 /* Or vice versa. */
3733 || (orig_op1 == null_node
3734 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3735 /* Or, both are NULL and the operation was not a comparison. */
3736 || (orig_op0 == null_node && orig_op1 == null_node
3737 && code != EQ_EXPR && code != NE_EXPR)))
3738 /* Some sort of arithmetic operation involving NULL was
3739 performed. Note that pointer-difference and pointer-addition
3740 have already been handled above, and so we don't end up here in
3742 warning (0, "NULL used in arithmetic");
3746 if (TREE_TYPE (op0) != result_type)
3747 op0 = cp_convert (result_type, op0);
3748 if (TREE_TYPE (op1) != result_type)
3749 op1 = cp_convert (result_type, op1);
3751 if (op0 == error_mark_node || op1 == error_mark_node)
3752 return error_mark_node;
3755 if (build_type == NULL_TREE)
3756 build_type = result_type;
3758 result = build2 (resultcode, build_type, op0, op1);
3759 result = fold_if_not_in_template (result);
3760 if (final_type != 0)
3761 result = cp_convert (final_type, result);
3765 /* Return a tree for the sum or difference (RESULTCODE says which)
3766 of pointer PTROP and integer INTOP. */
3769 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3771 tree res_type = TREE_TYPE (ptrop);
3773 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3774 in certain circumstance (when it's valid to do so). So we need
3775 to make sure it's complete. We don't need to check here, if we
3776 can actually complete it at all, as those checks will be done in
3777 pointer_int_sum() anyway. */
3778 complete_type (TREE_TYPE (res_type));
3780 return pointer_int_sum (resultcode, ptrop,
3781 fold_if_not_in_template (intop));
3784 /* Return a tree for the difference of pointers OP0 and OP1.
3785 The resulting tree has type int. */
3788 pointer_diff (tree op0, tree op1, tree ptrtype)
3791 tree restype = ptrdiff_type_node;
3792 tree target_type = TREE_TYPE (ptrtype);
3794 if (!complete_type_or_else (target_type, NULL_TREE))
3795 return error_mark_node;
3797 if (pedantic || warn_pointer_arith)
3799 if (TREE_CODE (target_type) == VOID_TYPE)
3800 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3801 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3802 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3803 if (TREE_CODE (target_type) == METHOD_TYPE)
3804 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3807 /* First do the subtraction as integers;
3808 then drop through to build the divide operator. */
3810 op0 = cp_build_binary_op (MINUS_EXPR,
3811 cp_convert (restype, op0),
3812 cp_convert (restype, op1));
3814 /* This generates an error if op1 is a pointer to an incomplete type. */
3815 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3816 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3818 op1 = (TYPE_PTROB_P (ptrtype)
3819 ? size_in_bytes (target_type)
3820 : integer_one_node);
3822 /* Do the division. */
3824 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3825 return fold_if_not_in_template (result);
3828 /* Construct and perhaps optimize a tree representation
3829 for a unary operation. CODE, a tree_code, specifies the operation
3830 and XARG is the operand. */
3833 build_x_unary_op (enum tree_code code, tree xarg)
3835 tree orig_expr = xarg;
3839 if (processing_template_decl)
3841 if (type_dependent_expression_p (xarg))
3842 return build_min_nt (code, xarg, NULL_TREE);
3844 xarg = build_non_dependent_expr (xarg);
3849 /* [expr.unary.op] says:
3851 The address of an object of incomplete type can be taken.
3853 (And is just the ordinary address operator, not an overloaded
3854 "operator &".) However, if the type is a template
3855 specialization, we must complete the type at this point so that
3856 an overloaded "operator &" will be available if required. */
3857 if (code == ADDR_EXPR
3858 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3859 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3860 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3861 || (TREE_CODE (xarg) == OFFSET_REF)))
3862 /* Don't look for a function. */;
3864 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3865 /*overloaded_p=*/NULL);
3866 if (!exp && code == ADDR_EXPR)
3868 /* A pointer to member-function can be formed only by saying
3870 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3871 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3873 if (TREE_CODE (xarg) != OFFSET_REF
3874 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3876 error ("invalid use of %qE to form a pointer-to-member-function",
3878 if (TREE_CODE (xarg) != OFFSET_REF)
3879 inform (" a qualified-id is required");
3880 return error_mark_node;
3884 error ("parentheses around %qE cannot be used to form a"
3885 " pointer-to-member-function",
3887 PTRMEM_OK_P (xarg) = 1;
3891 if (TREE_CODE (xarg) == OFFSET_REF)
3893 ptrmem = PTRMEM_OK_P (xarg);
3895 if (!ptrmem && !flag_ms_extensions
3896 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3898 /* A single non-static member, make sure we don't allow a
3899 pointer-to-member. */
3900 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3901 TREE_OPERAND (xarg, 0),
3902 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3903 PTRMEM_OK_P (xarg) = ptrmem;
3906 else if (TREE_CODE (xarg) == TARGET_EXPR)
3907 warning (0, "taking address of temporary");
3908 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3911 if (processing_template_decl && exp != error_mark_node)
3912 exp = build_min_non_dep (code, exp, orig_expr,
3913 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3914 if (TREE_CODE (exp) == ADDR_EXPR)
3915 PTRMEM_OK_P (exp) = ptrmem;
3919 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3920 constants, where a null value is represented by an INTEGER_CST of
3924 cp_truthvalue_conversion (tree expr)
3926 tree type = TREE_TYPE (expr);
3927 if (TYPE_PTRMEM_P (type))
3928 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3930 return c_common_truthvalue_conversion (expr);
3933 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3936 condition_conversion (tree expr)
3939 if (processing_template_decl)
3941 t = perform_implicit_conversion (boolean_type_node, expr);
3942 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3946 /* Return an ADDR_EXPR giving the address of T. This function
3947 attempts no optimizations or simplifications; it is a low-level
3951 build_address (tree t)
3955 if (error_operand_p (t) || !cxx_mark_addressable (t))
3956 return error_mark_node;
3958 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3963 /* Return a NOP_EXPR converting EXPR to TYPE. */
3966 build_nop (tree type, tree expr)
3968 if (type == error_mark_node || error_operand_p (expr))
3970 return build1 (NOP_EXPR, type, expr);
3973 /* C++: Must handle pointers to members.
3975 Perhaps type instantiation should be extended to handle conversion
3976 from aggregates to types we don't yet know we want? (Or are those
3977 cases typically errors which should be reported?)
3979 NOCONVERT nonzero suppresses the default promotions
3980 (such as from short to int). */
3983 build_unary_op (enum tree_code code, tree xarg, int noconvert)
3985 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
3988 const char *errstring = NULL;
3990 const char *invalid_op_diag;
3992 if (arg == error_mark_node)
3993 return error_mark_node;
3995 if ((invalid_op_diag
3996 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4001 error (invalid_op_diag);
4002 return error_mark_node;
4007 case UNARY_PLUS_EXPR:
4010 int flags = WANT_ARITH | WANT_ENUM;
4011 /* Unary plus (but not unary minus) is allowed on pointers. */
4012 if (code == UNARY_PLUS_EXPR)
4013 flags |= WANT_POINTER;
4014 arg = build_expr_type_conversion (flags, arg, true);
4016 errstring = (code == NEGATE_EXPR
4017 ? "wrong type argument to unary minus"
4018 : "wrong type argument to unary plus");
4021 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4022 arg = perform_integral_promotions (arg);
4024 /* Make sure the result is not an lvalue: a unary plus or minus
4025 expression is always a rvalue. */
4032 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4036 arg = default_conversion (arg);
4038 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4041 errstring = "wrong type argument to bit-complement";
4042 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4043 arg = perform_integral_promotions (arg);
4047 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4048 errstring = "wrong type argument to abs";
4049 else if (!noconvert)
4050 arg = default_conversion (arg);
4054 /* Conjugating a real value is a no-op, but allow it anyway. */
4055 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4056 errstring = "wrong type argument to conjugation";
4057 else if (!noconvert)
4058 arg = default_conversion (arg);
4061 case TRUTH_NOT_EXPR:
4062 arg = perform_implicit_conversion (boolean_type_node, arg);
4063 val = invert_truthvalue (arg);
4064 if (arg != error_mark_node)
4066 errstring = "in argument to unary !";
4073 if (TREE_CODE (arg) == COMPLEX_CST)
4074 return TREE_REALPART (arg);
4075 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4077 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4078 return fold_if_not_in_template (arg);
4084 if (TREE_CODE (arg) == COMPLEX_CST)
4085 return TREE_IMAGPART (arg);
4086 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4088 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4089 return fold_if_not_in_template (arg);
4092 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4094 case PREINCREMENT_EXPR:
4095 case POSTINCREMENT_EXPR:
4096 case PREDECREMENT_EXPR:
4097 case POSTDECREMENT_EXPR:
4098 /* Handle complex lvalues (when permitted)
4099 by reduction to simpler cases. */
4101 val = unary_complex_lvalue (code, arg);
4105 /* Increment or decrement the real part of the value,
4106 and don't change the imaginary part. */
4107 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4111 arg = stabilize_reference (arg);
4112 real = build_unary_op (REALPART_EXPR, arg, 1);
4113 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4114 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4115 build_unary_op (code, real, 1), imag);
4118 /* Report invalid types. */
4120 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4123 if (code == PREINCREMENT_EXPR)
4124 errstring ="no pre-increment operator for type";
4125 else if (code == POSTINCREMENT_EXPR)
4126 errstring ="no post-increment operator for type";
4127 else if (code == PREDECREMENT_EXPR)
4128 errstring ="no pre-decrement operator for type";
4130 errstring ="no post-decrement operator for type";
4134 /* Report something read-only. */
4136 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4137 || TREE_READONLY (arg))
4138 readonly_error (arg, ((code == PREINCREMENT_EXPR
4139 || code == POSTINCREMENT_EXPR)
4140 ? "increment" : "decrement"),
4146 tree result_type = TREE_TYPE (arg);
4148 declared_type = unlowered_expr_type (arg);
4150 arg = get_unwidened (arg, 0);
4151 argtype = TREE_TYPE (arg);
4153 /* ARM $5.2.5 last annotation says this should be forbidden. */
4154 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4155 pedwarn ("ISO C++ forbids %sing an enum",
4156 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4157 ? "increment" : "decrement");
4159 /* Compute the increment. */
4161 if (TREE_CODE (argtype) == POINTER_TYPE)
4163 tree type = complete_type (TREE_TYPE (argtype));
4165 if (!COMPLETE_OR_VOID_TYPE_P (type))
4166 error ("cannot %s a pointer to incomplete type %qT",
4167 ((code == PREINCREMENT_EXPR
4168 || code == POSTINCREMENT_EXPR)
4169 ? "increment" : "decrement"), TREE_TYPE (argtype));
4170 else if ((pedantic || warn_pointer_arith)
4171 && !TYPE_PTROB_P (argtype))
4172 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
4173 ((code == PREINCREMENT_EXPR
4174 || code == POSTINCREMENT_EXPR)
4175 ? "increment" : "decrement"), argtype);
4176 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4179 inc = integer_one_node;
4181 inc = cp_convert (argtype, inc);
4183 /* Handle incrementing a cast-expression. */
4185 switch (TREE_CODE (arg))
4190 case FIX_TRUNC_EXPR:
4191 case FIX_FLOOR_EXPR:
4192 case FIX_ROUND_EXPR:
4195 tree incremented, modify, value, compound;
4196 if (! lvalue_p (arg) && pedantic)
4197 pedwarn ("cast to non-reference type used as lvalue");
4198 arg = stabilize_reference (arg);
4199 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4202 value = save_expr (arg);
4203 incremented = build2 (((code == PREINCREMENT_EXPR
4204 || code == POSTINCREMENT_EXPR)
4205 ? PLUS_EXPR : MINUS_EXPR),
4206 argtype, value, inc);
4208 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4209 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4212 /* Eliminate warning about unused result of + or -. */
4213 TREE_NO_WARNING (compound) = 1;
4221 /* Complain about anything else that is not a true lvalue. */
4222 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4223 || code == POSTINCREMENT_EXPR)
4224 ? lv_increment : lv_decrement)))
4225 return error_mark_node;
4227 /* Forbid using -- on `bool'. */
4228 if (same_type_p (declared_type, boolean_type_node))
4230 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4232 error ("invalid use of %<--%> on bool variable %qD", arg);
4233 return error_mark_node;
4235 val = boolean_increment (code, arg);
4238 val = build2 (code, TREE_TYPE (arg), arg, inc);
4240 TREE_SIDE_EFFECTS (val) = 1;
4241 return cp_convert (result_type, val);
4245 /* Note that this operation never does default_conversion
4246 regardless of NOCONVERT. */
4248 argtype = lvalue_type (arg);
4250 if (TREE_CODE (arg) == OFFSET_REF)
4253 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4255 tree type = build_pointer_type (TREE_TYPE (argtype));
4256 arg = build1 (CONVERT_EXPR, type, arg);
4259 else if (pedantic && DECL_MAIN_P (arg))
4261 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4263 /* Let &* cancel out to simplify resulting code. */
4264 if (TREE_CODE (arg) == INDIRECT_REF)
4266 /* We don't need to have `current_class_ptr' wrapped in a
4267 NON_LVALUE_EXPR node. */
4268 if (arg == current_class_ref)
4269 return current_class_ptr;
4271 arg = TREE_OPERAND (arg, 0);
4272 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4274 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4275 arg = build1 (CONVERT_EXPR, type, arg);
4278 /* Don't let this be an lvalue. */
4283 /* Uninstantiated types are all functions. Taking the
4284 address of a function is a no-op, so just return the
4287 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4288 || !IDENTIFIER_OPNAME_P (arg));
4290 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4291 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4293 /* They're trying to take the address of a unique non-static
4294 member function. This is ill-formed (except in MS-land),
4295 but let's try to DTRT.
4296 Note: We only handle unique functions here because we don't
4297 want to complain if there's a static overload; non-unique
4298 cases will be handled by instantiate_type. But we need to
4299 handle this case here to allow casts on the resulting PMF.
4300 We could defer this in non-MS mode, but it's easier to give
4301 a useful error here. */
4303 /* Inside constant member functions, the `this' pointer
4304 contains an extra const qualifier. TYPE_MAIN_VARIANT
4305 is used here to remove this const from the diagnostics
4306 and the created OFFSET_REF. */
4307 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4308 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4311 if (! flag_ms_extensions)
4313 tree name = DECL_NAME (fn);
4314 if (current_class_type
4315 && TREE_OPERAND (arg, 0) == current_class_ref)
4316 /* An expression like &memfn. */
4317 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4318 " or parenthesized non-static member function to form"
4319 " a pointer to member function. Say %<&%T::%D%>",
4322 pedwarn ("ISO C++ forbids taking the address of a bound member"
4323 " function to form a pointer to member function."
4327 arg = build_offset_ref (base, fn, /*address_p=*/true);
4331 if (type_unknown_p (arg))
4332 return build1 (ADDR_EXPR, unknown_type_node, arg);
4334 /* Handle complex lvalues (when permitted)
4335 by reduction to simpler cases. */
4336 val = unary_complex_lvalue (code, arg);
4340 switch (TREE_CODE (arg))
4345 case FIX_TRUNC_EXPR:
4346 case FIX_FLOOR_EXPR:
4347 case FIX_ROUND_EXPR:
4349 if (! lvalue_p (arg) && pedantic)
4350 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4354 arg = BASELINK_FUNCTIONS (arg);
4358 arg = OVL_CURRENT (arg);
4362 /* Turn a reference to a non-static data member into a
4363 pointer-to-member. */
4368 if (!PTRMEM_OK_P (arg))
4369 return build_unary_op (code, arg, 0);
4371 t = TREE_OPERAND (arg, 1);
4372 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4374 error ("cannot create pointer to reference member %qD", t);
4375 return error_mark_node;
4378 type = build_ptrmem_type (context_for_name_lookup (t),
4380 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4388 /* Anything not already handled and not a true memory reference
4390 if (TREE_CODE (argtype) != FUNCTION_TYPE
4391 && TREE_CODE (argtype) != METHOD_TYPE
4392 && TREE_CODE (arg) != OFFSET_REF
4393 && !lvalue_or_else (arg, lv_addressof))
4394 return error_mark_node;
4396 if (argtype != error_mark_node)
4397 argtype = build_pointer_type (argtype);
4399 /* In a template, we are processing a non-dependent expression
4400 so we can just form an ADDR_EXPR with the correct type. */
4401 if (processing_template_decl)
4403 val = build_address (arg);
4404 if (TREE_CODE (arg) == OFFSET_REF)
4405 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4409 if (TREE_CODE (arg) != COMPONENT_REF)
4411 val = build_address (arg);
4412 if (TREE_CODE (arg) == OFFSET_REF)
4413 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4415 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4417 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4419 /* We can only get here with a single static member
4421 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4422 && DECL_STATIC_FUNCTION_P (fn));
4424 val = build_address (fn);
4425 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4426 /* Do not lose object's side effects. */
4427 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4428 TREE_OPERAND (arg, 0), val);
4430 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4432 error ("attempt to take address of bit-field structure member %qD",
4433 TREE_OPERAND (arg, 1));
4434 return error_mark_node;
4438 tree object = TREE_OPERAND (arg, 0);
4439 tree field = TREE_OPERAND (arg, 1);
4440 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4441 (TREE_TYPE (object), decl_type_context (field)));
4442 val = build_address (arg);
4445 if (TREE_CODE (argtype) == POINTER_TYPE
4446 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4448 build_ptrmemfunc_type (argtype);
4449 val = build_ptrmemfunc (argtype, val, 0,
4450 /*c_cast_p=*/false);
4462 argtype = TREE_TYPE (arg);
4463 return fold_if_not_in_template (build1 (code, argtype, arg));
4466 error ("%s", errstring);
4467 return error_mark_node;
4470 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4471 for certain kinds of expressions which are not really lvalues
4472 but which we can accept as lvalues.
4474 If ARG is not a kind of expression we can handle, return
4478 unary_complex_lvalue (enum tree_code code, tree arg)
4480 /* Inside a template, making these kinds of adjustments is
4481 pointless; we are only concerned with the type of the
4483 if (processing_template_decl)
4486 /* Handle (a, b) used as an "lvalue". */
4487 if (TREE_CODE (arg) == COMPOUND_EXPR)
4489 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4490 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4491 TREE_OPERAND (arg, 0), real_result);
4494 /* Handle (a ? b : c) used as an "lvalue". */
4495 if (TREE_CODE (arg) == COND_EXPR
4496 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4497 return rationalize_conditional_expr (code, arg);
4499 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4500 if (TREE_CODE (arg) == MODIFY_EXPR
4501 || TREE_CODE (arg) == PREINCREMENT_EXPR
4502 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4504 tree lvalue = TREE_OPERAND (arg, 0);
4505 if (TREE_SIDE_EFFECTS (lvalue))
4507 lvalue = stabilize_reference (lvalue);
4508 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4509 lvalue, TREE_OPERAND (arg, 1));
4511 return unary_complex_lvalue
4512 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4515 if (code != ADDR_EXPR)
4518 /* Handle (a = b) used as an "lvalue" for `&'. */
4519 if (TREE_CODE (arg) == MODIFY_EXPR
4520 || TREE_CODE (arg) == INIT_EXPR)
4522 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4523 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4525 TREE_NO_WARNING (arg) = 1;
4529 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4530 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4531 || TREE_CODE (arg) == OFFSET_REF)
4534 /* We permit compiler to make function calls returning
4535 objects of aggregate type look like lvalues. */
4539 if (TREE_CODE (targ) == SAVE_EXPR)
4540 targ = TREE_OPERAND (targ, 0);
4542 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4544 if (TREE_CODE (arg) == SAVE_EXPR)
4547 targ = build_cplus_new (TREE_TYPE (arg), arg);
4548 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4551 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4552 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4553 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4556 /* Don't let anything else be handled specially. */
4560 /* Mark EXP saying that we need to be able to take the
4561 address of it; it should not be allocated in a register.
4562 Value is true if successful.
4564 C++: we do not allow `current_class_ptr' to be addressable. */
4567 cxx_mark_addressable (tree exp)
4572 switch (TREE_CODE (x))
4579 x = TREE_OPERAND (x, 0);
4583 if (x == current_class_ptr)
4585 error ("cannot take the address of %<this%>, which is an rvalue expression");
4586 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4592 /* Caller should not be trying to mark initialized
4593 constant fields addressable. */
4594 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4595 || DECL_IN_AGGR_P (x) == 0
4597 || DECL_EXTERNAL (x));
4602 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4603 && !DECL_ARTIFICIAL (x))
4605 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4608 ("address of explicit register variable %qD requested", x);
4611 else if (extra_warnings)
4613 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4615 TREE_ADDRESSABLE (x) = 1;
4619 TREE_ADDRESSABLE (x) = 1;
4623 TREE_ADDRESSABLE (x) = 1;
4627 TREE_ADDRESSABLE (x) = 1;
4628 cxx_mark_addressable (TREE_OPERAND (x, 0));
4636 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4639 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4641 tree orig_ifexp = ifexp;
4642 tree orig_op1 = op1;
4643 tree orig_op2 = op2;
4646 if (processing_template_decl)
4648 /* The standard says that the expression is type-dependent if
4649 IFEXP is type-dependent, even though the eventual type of the
4650 expression doesn't dependent on IFEXP. */
4651 if (type_dependent_expression_p (ifexp)
4652 /* As a GNU extension, the middle operand may be omitted. */
4653 || (op1 && type_dependent_expression_p (op1))
4654 || type_dependent_expression_p (op2))
4655 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4656 ifexp = build_non_dependent_expr (ifexp);
4658 op1 = build_non_dependent_expr (op1);
4659 op2 = build_non_dependent_expr (op2);
4662 expr = build_conditional_expr (ifexp, op1, op2);
4663 if (processing_template_decl && expr != error_mark_node)
4664 return build_min_non_dep (COND_EXPR, expr,
4665 orig_ifexp, orig_op1, orig_op2);
4669 /* Given a list of expressions, return a compound expression
4670 that performs them all and returns the value of the last of them. */
4672 tree build_x_compound_expr_from_list (tree list, const char *msg)
4674 tree expr = TREE_VALUE (list);
4676 if (TREE_CHAIN (list))
4679 pedwarn ("%s expression list treated as compound expression", msg);
4681 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4682 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4688 /* Handle overloading of the ',' operator when needed. */
4691 build_x_compound_expr (tree op1, tree op2)
4694 tree orig_op1 = op1;
4695 tree orig_op2 = op2;
4697 if (processing_template_decl)
4699 if (type_dependent_expression_p (op1)
4700 || type_dependent_expression_p (op2))
4701 return build_min_nt (COMPOUND_EXPR, op1, op2);
4702 op1 = build_non_dependent_expr (op1);
4703 op2 = build_non_dependent_expr (op2);
4706 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4707 /*overloaded_p=*/NULL);
4709 result = build_compound_expr (op1, op2);
4711 if (processing_template_decl && result != error_mark_node)
4712 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4717 /* Build a compound expression. */
4720 build_compound_expr (tree lhs, tree rhs)
4722 lhs = convert_to_void (lhs, "left-hand operand of comma");
4724 if (lhs == error_mark_node || rhs == error_mark_node)
4725 return error_mark_node;
4727 if (TREE_CODE (rhs) == TARGET_EXPR)
4729 /* If the rhs is a TARGET_EXPR, then build the compound
4730 expression inside the target_expr's initializer. This
4731 helps the compiler to eliminate unnecessary temporaries. */
4732 tree init = TREE_OPERAND (rhs, 1);
4734 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4735 TREE_OPERAND (rhs, 1) = init;
4740 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4743 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4744 casts away constness. DIAG_FN gives the function to call if we
4745 need to issue a diagnostic; if it is NULL, no diagnostic will be
4746 issued. DESCRIPTION explains what operation is taking place. */
4749 check_for_casting_away_constness (tree src_type, tree dest_type,
4750 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4751 const char *description)
4753 if (diag_fn && casts_away_constness (src_type, dest_type))
4754 diag_fn ("%s from type %qT to type %qT casts away constness",
4755 description, src_type, dest_type);
4758 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4759 (another pointer-to-member type in the same hierarchy) and return
4760 the converted expression. If ALLOW_INVERSE_P is permitted, a
4761 pointer-to-derived may be converted to pointer-to-base; otherwise,
4762 only the other direction is permitted. If C_CAST_P is true, this
4763 conversion is taking place as part of a C-style cast. */
4766 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4769 if (TYPE_PTRMEM_P (type))
4773 if (TREE_CODE (expr) == PTRMEM_CST)
4774 expr = cplus_expand_constant (expr);
4775 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4776 TYPE_PTRMEM_CLASS_TYPE (type),
4779 if (!integer_zerop (delta))
4780 expr = cp_build_binary_op (PLUS_EXPR,
4781 build_nop (ptrdiff_type_node, expr),
4783 return build_nop (type, expr);
4786 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4787 allow_inverse_p, c_cast_p);
4790 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4791 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4792 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4795 ignore_overflows (tree expr, tree orig)
4797 if (TREE_CODE (expr) == INTEGER_CST
4798 && CONSTANT_CLASS_P (orig)
4799 && TREE_CODE (orig) != STRING_CST
4800 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4801 || TREE_CONSTANT_OVERFLOW (expr)
4802 != TREE_CONSTANT_OVERFLOW (orig)))
4804 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4805 /* Ensure constant sharing. */
4806 expr = build_int_cst_wide (TREE_TYPE (expr),
4807 TREE_INT_CST_LOW (expr),
4808 TREE_INT_CST_HIGH (expr));
4811 /* Avoid clobbering a shared constant. */
4812 expr = copy_node (expr);
4813 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4814 TREE_CONSTANT_OVERFLOW (expr)
4815 = TREE_CONSTANT_OVERFLOW (orig);
4821 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4822 this static_cast is being attempted as one of the possible casts
4823 allowed by a C-style cast. (In that case, accessibility of base
4824 classes is not considered, and it is OK to cast away
4825 constness.) Return the result of the cast. *VALID_P is set to
4826 indicate whether or not the cast was valid. */
4829 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4835 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4838 /* Assume the cast is valid. */
4841 intype = TREE_TYPE (expr);
4843 /* Save casted types in the function's used types hash table. */
4844 used_types_insert (type);
4846 /* Determine what to do when casting away constness. */
4849 /* C-style casts are allowed to cast away constness. With
4850 WARN_CAST_QUAL, we still want to issue a warning. */
4851 diag_fn = warn_cast_qual ? warning0 : NULL;
4856 /* A static_cast may not cast away constness. */
4858 desc = "static_cast";
4861 /* [expr.static.cast]
4863 An lvalue of type "cv1 B", where B is a class type, can be cast
4864 to type "reference to cv2 D", where D is a class derived (clause
4865 _class.derived_) from B, if a valid standard conversion from
4866 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4867 same cv-qualification as, or greater cv-qualification than, cv1,
4868 and B is not a virtual base class of D. */
4869 /* We check this case before checking the validity of "TYPE t =
4870 EXPR;" below because for this case:
4873 struct D : public B { D(const B&); };
4875 void f() { static_cast<const D&>(b); }
4877 we want to avoid constructing a new D. The standard is not
4878 completely clear about this issue, but our interpretation is
4879 consistent with other compilers. */
4880 if (TREE_CODE (type) == REFERENCE_TYPE
4881 && CLASS_TYPE_P (TREE_TYPE (type))
4882 && CLASS_TYPE_P (intype)
4883 && real_lvalue_p (expr)
4884 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4885 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4886 build_pointer_type (TYPE_MAIN_VARIANT
4887 (TREE_TYPE (type))))
4889 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4893 /* There is a standard conversion from "D*" to "B*" even if "B"
4894 is ambiguous or inaccessible. If this is really a
4895 static_cast, then we check both for inaccessibility and
4896 ambiguity. However, if this is a static_cast being performed
4897 because the user wrote a C-style cast, then accessibility is
4899 base = lookup_base (TREE_TYPE (type), intype,
4900 c_cast_p ? ba_unique : ba_check,
4903 /* Convert from "B*" to "D*". This function will check that "B"
4904 is not a virtual base of "D". */
4905 expr = build_base_path (MINUS_EXPR, build_address (expr),
4906 base, /*nonnull=*/false);
4907 /* Convert the pointer to a reference -- but then remember that
4908 there are no expressions with reference type in C++. */
4909 return convert_from_reference (build_nop (type, expr));
4914 /* [expr.static.cast]
4916 An expression e can be explicitly converted to a type T using a
4917 static_cast of the form static_cast<T>(e) if the declaration T
4918 t(e);" is well-formed, for some invented temporary variable
4920 result = perform_direct_initialization_if_possible (type, expr,
4924 result = convert_from_reference (result);
4926 /* Ignore any integer overflow caused by the cast. */
4927 result = ignore_overflows (result, orig);
4929 /* [expr.static.cast]
4931 If T is a reference type, the result is an lvalue; otherwise,
4932 the result is an rvalue. */
4933 if (TREE_CODE (type) != REFERENCE_TYPE)
4934 result = rvalue (result);
4938 /* [expr.static.cast]
4940 Any expression can be explicitly converted to type cv void. */
4941 if (TREE_CODE (type) == VOID_TYPE)
4942 return convert_to_void (expr, /*implicit=*/NULL);
4944 /* [expr.static.cast]
4946 The inverse of any standard conversion sequence (clause _conv_),
4947 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4948 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4949 (_conv.bool_) conversions, can be performed explicitly using
4950 static_cast subject to the restriction that the explicit
4951 conversion does not cast away constness (_expr.const.cast_), and
4952 the following additional rules for specific cases: */
4953 /* For reference, the conversions not excluded are: integral
4954 promotions, floating point promotion, integral conversions,
4955 floating point conversions, floating-integral conversions,
4956 pointer conversions, and pointer to member conversions. */
4959 A value of integral _or enumeration_ type can be explicitly
4960 converted to an enumeration type. */
4961 /* The effect of all that is that any conversion between any two
4962 types which are integral, floating, or enumeration types can be
4964 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4965 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4967 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4969 /* Ignore any integer overflow caused by the cast. */
4970 expr = ignore_overflows (expr, orig);
4974 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4975 && CLASS_TYPE_P (TREE_TYPE (type))
4976 && CLASS_TYPE_P (TREE_TYPE (intype))
4977 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4978 (TREE_TYPE (intype))),
4979 build_pointer_type (TYPE_MAIN_VARIANT
4980 (TREE_TYPE (type)))))
4985 check_for_casting_away_constness (intype, type, diag_fn, desc);
4986 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4987 c_cast_p ? ba_unique : ba_check,
4989 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
4992 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
4993 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5000 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5001 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5003 if (TYPE_PTRMEM_P (type))
5005 t1 = (build_ptrmem_type
5007 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5008 t2 = (build_ptrmem_type
5010 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5017 if (can_convert (t1, t2))
5020 check_for_casting_away_constness (intype, type, diag_fn,
5022 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5027 /* [expr.static.cast]
5029 An rvalue of type "pointer to cv void" can be explicitly
5030 converted to a pointer to object type. A value of type pointer
5031 to object converted to "pointer to cv void" and back to the
5032 original pointer type will have its original value. */
5033 if (TREE_CODE (intype) == POINTER_TYPE
5034 && VOID_TYPE_P (TREE_TYPE (intype))
5035 && TYPE_PTROB_P (type))
5038 check_for_casting_away_constness (intype, type, diag_fn, desc);
5039 return build_nop (type, expr);
5043 return error_mark_node;
5046 /* Return an expression representing static_cast<TYPE>(EXPR). */
5049 build_static_cast (tree type, tree expr)
5054 if (type == error_mark_node || expr == error_mark_node)
5055 return error_mark_node;
5057 if (processing_template_decl)
5059 expr = build_min (STATIC_CAST_EXPR, type, expr);
5060 /* We don't know if it will or will not have side effects. */
5061 TREE_SIDE_EFFECTS (expr) = 1;
5062 return convert_from_reference (expr);
5065 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5066 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5067 if (TREE_CODE (type) != REFERENCE_TYPE
5068 && TREE_CODE (expr) == NOP_EXPR
5069 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5070 expr = TREE_OPERAND (expr, 0);
5072 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5076 error ("invalid static_cast from type %qT to type %qT",
5077 TREE_TYPE (expr), type);
5078 return error_mark_node;
5081 /* EXPR is an expression with member function or pointer-to-member
5082 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5083 not permitted by ISO C++, but we accept it in some modes. If we
5084 are not in one of those modes, issue a diagnostic. Return the
5085 converted expression. */
5088 convert_member_func_to_ptr (tree type, tree expr)
5093 intype = TREE_TYPE (expr);
5094 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5095 || TREE_CODE (intype) == METHOD_TYPE);
5097 if (pedantic || warn_pmf2ptr)
5098 pedwarn ("converting from %qT to %qT", intype, type);
5100 if (TREE_CODE (intype) == METHOD_TYPE)
5101 expr = build_addr_func (expr);
5102 else if (TREE_CODE (expr) == PTRMEM_CST)
5103 expr = build_address (PTRMEM_CST_MEMBER (expr));
5106 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5107 decl = build_address (decl);
5108 expr = get_member_function_from_ptrfunc (&decl, expr);
5111 return build_nop (type, expr);
5114 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5115 If C_CAST_P is true, this reinterpret cast is being done as part of
5116 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5117 indicate whether or not reinterpret_cast was valid. */
5120 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5125 /* Assume the cast is invalid. */
5129 if (type == error_mark_node || error_operand_p (expr))
5130 return error_mark_node;
5132 intype = TREE_TYPE (expr);
5134 /* Save casted types in the function's used types hash table. */
5135 used_types_insert (type);
5137 /* [expr.reinterpret.cast]
5138 An lvalue expression of type T1 can be cast to the type
5139 "reference to T2" if an expression of type "pointer to T1" can be
5140 explicitly converted to the type "pointer to T2" using a
5141 reinterpret_cast. */
5142 if (TREE_CODE (type) == REFERENCE_TYPE)
5144 if (! real_lvalue_p (expr))
5146 error ("invalid cast of an rvalue expression of type "
5149 return error_mark_node;
5152 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5153 "B" are related class types; the reinterpret_cast does not
5154 adjust the pointer. */
5155 if (TYPE_PTR_P (intype)
5156 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5157 COMPARE_BASE | COMPARE_DERIVED)))
5158 warning (0, "casting %qT to %qT does not dereference pointer",
5161 expr = build_unary_op (ADDR_EXPR, expr, 0);
5162 if (expr != error_mark_node)
5163 expr = build_reinterpret_cast_1
5164 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5166 if (expr != error_mark_node)
5167 expr = build_indirect_ref (expr, 0);
5171 /* As a G++ extension, we consider conversions from member
5172 functions, and pointers to member functions to
5173 pointer-to-function and pointer-to-void types. If
5174 -Wno-pmf-conversions has not been specified,
5175 convert_member_func_to_ptr will issue an error message. */
5176 if ((TYPE_PTRMEMFUNC_P (intype)
5177 || TREE_CODE (intype) == METHOD_TYPE)
5178 && TYPE_PTR_P (type)
5179 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5180 || VOID_TYPE_P (TREE_TYPE (type))))
5181 return convert_member_func_to_ptr (type, expr);
5183 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5184 array-to-pointer, and function-to-pointer conversions are
5186 expr = decay_conversion (expr);
5188 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5189 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5190 if (TREE_CODE (expr) == NOP_EXPR
5191 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5192 expr = TREE_OPERAND (expr, 0);
5194 if (error_operand_p (expr))
5195 return error_mark_node;
5197 intype = TREE_TYPE (expr);
5199 /* [expr.reinterpret.cast]
5200 A pointer can be converted to any integral type large enough to
5202 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5204 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5205 pedwarn ("cast from %qT to %qT loses precision",
5208 /* [expr.reinterpret.cast]
5209 A value of integral or enumeration type can be explicitly
5210 converted to a pointer. */
5211 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5214 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5215 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5216 return fold_if_not_in_template (build_nop (type, expr));
5217 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5218 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5223 check_for_casting_away_constness (intype, type, error,
5224 "reinterpret_cast");
5225 /* Warn about possible alignment problems. */
5226 if (STRICT_ALIGNMENT && warn_cast_align
5227 && !VOID_TYPE_P (type)
5228 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5229 && COMPLETE_TYPE_P (TREE_TYPE (type))
5230 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5231 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5232 warning (0, "cast from %qT to %qT increases required alignment of "
5236 /* We need to strip nops here, because the frontend likes to
5237 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5239 strict_aliasing_warning (intype, type, sexpr);
5241 return fold_if_not_in_template (build_nop (type, expr));
5243 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5244 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5247 /* Only issue a warning, as we have always supported this
5248 where possible, and it is necessary in some cases. DR 195
5249 addresses this issue, but as of 2004/10/26 is still in
5251 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5252 return fold_if_not_in_template (build_nop (type, expr));
5254 else if (TREE_CODE (type) == VECTOR_TYPE)
5255 return fold_if_not_in_template (convert_to_vector (type, expr));
5256 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5257 return fold_if_not_in_template (convert_to_integer (type, expr));
5262 error ("invalid cast from type %qT to type %qT", intype, type);
5263 return error_mark_node;
5266 return cp_convert (type, expr);
5270 build_reinterpret_cast (tree type, tree expr)
5272 if (type == error_mark_node || expr == error_mark_node)
5273 return error_mark_node;
5275 if (processing_template_decl)
5277 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5279 if (!TREE_SIDE_EFFECTS (t)
5280 && type_dependent_expression_p (expr))
5281 /* There might turn out to be side effects inside expr. */
5282 TREE_SIDE_EFFECTS (t) = 1;
5283 return convert_from_reference (t);
5286 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5290 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5291 return an appropriate expression. Otherwise, return
5292 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5293 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5294 performing a C-style cast, its value upon return will indicate
5295 whether or not the conversion succeeded. */
5298 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5302 tree reference_type;
5304 /* Callers are responsible for handling error_mark_node as a
5305 destination type. */
5306 gcc_assert (dst_type != error_mark_node);
5307 /* In a template, callers should be building syntactic
5308 representations of casts, not using this machinery. */
5309 gcc_assert (!processing_template_decl);
5311 /* Assume the conversion is invalid. */
5315 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5318 error ("invalid use of const_cast with type %qT, "
5319 "which is not a pointer, "
5320 "reference, nor a pointer-to-data-member type", dst_type);
5321 return error_mark_node;
5324 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5327 error ("invalid use of const_cast with type %qT, which is a pointer "
5328 "or reference to a function type", dst_type);
5329 return error_mark_node;
5332 /* Save casted types in the function's used types hash table. */
5333 used_types_insert (dst_type);
5335 src_type = TREE_TYPE (expr);
5336 /* Expressions do not really have reference types. */
5337 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5338 src_type = TREE_TYPE (src_type);
5340 /* [expr.const.cast]
5342 An lvalue of type T1 can be explicitly converted to an lvalue of
5343 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5344 types) if a pointer to T1 can be explicitly converted to the type
5345 pointer to T2 using a const_cast. */
5346 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5348 reference_type = dst_type;
5349 if (! real_lvalue_p (expr))
5352 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5353 src_type, dst_type);
5354 return error_mark_node;
5356 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5357 src_type = build_pointer_type (src_type);
5361 reference_type = NULL_TREE;
5362 /* If the destination type is not a reference type, the
5363 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5364 conversions are performed. */
5365 src_type = type_decays_to (src_type);
5366 if (src_type == error_mark_node)
5367 return error_mark_node;
5370 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5371 && comp_ptr_ttypes_const (dst_type, src_type))
5376 /* This cast is actually a C-style cast. Issue a warning if
5377 the user is making a potentially unsafe cast. */
5379 check_for_casting_away_constness (src_type, dst_type,
5385 expr = build_unary_op (ADDR_EXPR, expr, 0);
5386 expr = build_nop (reference_type, expr);
5387 return convert_from_reference (expr);
5391 expr = decay_conversion (expr);
5392 /* build_c_cast puts on a NOP_EXPR to make the result not an
5393 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5394 non-lvalue context. */
5395 if (TREE_CODE (expr) == NOP_EXPR
5396 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5397 expr = TREE_OPERAND (expr, 0);
5398 return build_nop (dst_type, expr);
5403 error ("invalid const_cast from type %qT to type %qT",
5404 src_type, dst_type);
5405 return error_mark_node;
5409 build_const_cast (tree type, tree expr)
5411 if (type == error_mark_node || error_operand_p (expr))
5412 return error_mark_node;
5414 if (processing_template_decl)
5416 tree t = build_min (CONST_CAST_EXPR, type, expr);
5418 if (!TREE_SIDE_EFFECTS (t)
5419 && type_dependent_expression_p (expr))
5420 /* There might turn out to be side effects inside expr. */
5421 TREE_SIDE_EFFECTS (t) = 1;
5422 return convert_from_reference (t);
5425 return build_const_cast_1 (type, expr, /*complain=*/true,
5429 /* Build an expression representing an explicit C-style cast to type
5430 TYPE of expression EXPR. */
5433 build_c_cast (tree type, tree expr)
5439 if (type == error_mark_node || error_operand_p (expr))
5440 return error_mark_node;
5442 if (processing_template_decl)
5444 tree t = build_min (CAST_EXPR, type,
5445 tree_cons (NULL_TREE, value, NULL_TREE));
5446 /* We don't know if it will or will not have side effects. */
5447 TREE_SIDE_EFFECTS (t) = 1;
5448 return convert_from_reference (t);
5451 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5452 'Class') should always be retained, because this information aids
5453 in method lookup. */
5454 if (objc_is_object_ptr (type)
5455 && objc_is_object_ptr (TREE_TYPE (expr)))
5456 return build_nop (type, expr);
5458 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5459 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5460 if (TREE_CODE (type) != REFERENCE_TYPE
5461 && TREE_CODE (value) == NOP_EXPR
5462 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5463 value = TREE_OPERAND (value, 0);
5465 if (TREE_CODE (type) == ARRAY_TYPE)
5467 /* Allow casting from T1* to T2[] because Cfront allows it.
5468 NIHCL uses it. It is not valid ISO C++ however. */
5469 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5471 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5472 type = build_pointer_type (TREE_TYPE (type));
5476 error ("ISO C++ forbids casting to an array type %qT", type);
5477 return error_mark_node;
5481 if (TREE_CODE (type) == FUNCTION_TYPE
5482 || TREE_CODE (type) == METHOD_TYPE)
5484 error ("invalid cast to function type %qT", type);
5485 return error_mark_node;
5488 /* A C-style cast can be a const_cast. */
5489 result = build_const_cast_1 (type, value, /*complain=*/false,
5494 /* Or a static cast. */
5495 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5497 /* Or a reinterpret_cast. */
5499 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5501 /* The static_cast or reinterpret_cast may be followed by a
5504 /* A valid cast may result in errors if, for example, a
5505 conversion to am ambiguous base class is required. */
5506 && !error_operand_p (result))
5510 /* Non-class rvalues always have cv-unqualified type. */
5511 if (!CLASS_TYPE_P (type))
5512 type = TYPE_MAIN_VARIANT (type);
5513 result_type = TREE_TYPE (result);
5514 if (!CLASS_TYPE_P (result_type))
5515 result_type = TYPE_MAIN_VARIANT (result_type);
5516 /* If the type of RESULT does not match TYPE, perform a
5517 const_cast to make it match. If the static_cast or
5518 reinterpret_cast succeeded, we will differ by at most
5519 cv-qualification, so the follow-on const_cast is guaranteed
5521 if (!same_type_p (non_reference (type), non_reference (result_type)))
5523 result = build_const_cast_1 (type, result, false, &valid_p);
5524 gcc_assert (valid_p);
5529 return error_mark_node;
5532 /* Build an assignment expression of lvalue LHS from value RHS.
5533 MODIFYCODE is the code for a binary operator that we use
5534 to combine the old value of LHS with RHS to get the new value.
5535 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5537 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5540 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5544 tree lhstype = TREE_TYPE (lhs);
5545 tree olhstype = lhstype;
5546 tree olhs = NULL_TREE;
5547 bool plain_assign = (modifycode == NOP_EXPR);
5549 /* Avoid duplicate error messages from operands that had errors. */
5550 if (error_operand_p (lhs) || error_operand_p (rhs))
5551 return error_mark_node;
5553 /* Handle control structure constructs used as "lvalues". */
5554 switch (TREE_CODE (lhs))
5556 /* Handle --foo = 5; as these are valid constructs in C++. */
5557 case PREDECREMENT_EXPR:
5558 case PREINCREMENT_EXPR:
5559 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5560 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5561 stabilize_reference (TREE_OPERAND (lhs, 0)),
5562 TREE_OPERAND (lhs, 1));
5563 return build2 (COMPOUND_EXPR, lhstype,
5565 build_modify_expr (TREE_OPERAND (lhs, 0),
5568 /* Handle (a, b) used as an "lvalue". */
5570 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5572 if (newrhs == error_mark_node)
5573 return error_mark_node;
5574 return build2 (COMPOUND_EXPR, lhstype,
5575 TREE_OPERAND (lhs, 0), newrhs);
5578 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5579 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5580 stabilize_reference (TREE_OPERAND (lhs, 0)),
5581 TREE_OPERAND (lhs, 1));
5582 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5583 if (newrhs == error_mark_node)
5584 return error_mark_node;
5585 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5589 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5590 when neither operand has side-effects. */
5591 if (!lvalue_or_else (lhs, lv_assign))
5592 return error_mark_node;
5594 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5595 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5597 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5598 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5600 TREE_OPERAND (lhs, 0),
5601 TREE_OPERAND (lhs, 1)),
5602 TREE_OPERAND (lhs, 0),
5603 TREE_OPERAND (lhs, 1));
5606 /* Handle (a ? b : c) used as an "lvalue". */
5609 /* Produce (a ? (b = rhs) : (c = rhs))
5610 except that the RHS goes through a save-expr
5611 so the code to compute it is only emitted once. */
5613 tree preeval = NULL_TREE;
5615 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5617 error ("void value not ignored as it ought to be");
5618 return error_mark_node;
5621 rhs = stabilize_expr (rhs, &preeval);
5623 /* Check this here to avoid odd errors when trying to convert
5624 a throw to the type of the COND_EXPR. */
5625 if (!lvalue_or_else (lhs, lv_assign))
5626 return error_mark_node;
5628 cond = build_conditional_expr
5629 (TREE_OPERAND (lhs, 0),
5630 build_modify_expr (TREE_OPERAND (lhs, 1),
5632 build_modify_expr (TREE_OPERAND (lhs, 2),
5635 if (cond == error_mark_node)
5637 /* Make sure the code to compute the rhs comes out
5638 before the split. */
5640 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5648 if (modifycode == INIT_EXPR)
5650 if (TREE_CODE (rhs) == CONSTRUCTOR)
5652 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5653 /* Call convert to generate an error; see PR 11063. */
5654 rhs = convert (lhstype, rhs);
5655 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5656 TREE_SIDE_EFFECTS (result) = 1;
5659 else if (! IS_AGGR_TYPE (lhstype))
5660 /* Do the default thing. */;
5663 result = build_special_member_call (lhs, complete_ctor_identifier,
5664 build_tree_list (NULL_TREE, rhs),
5665 lhstype, LOOKUP_NORMAL);
5666 if (result == NULL_TREE)
5667 return error_mark_node;
5673 lhs = require_complete_type (lhs);
5674 if (lhs == error_mark_node)
5675 return error_mark_node;
5677 if (modifycode == NOP_EXPR)
5679 /* `operator=' is not an inheritable operator. */
5680 if (! IS_AGGR_TYPE (lhstype))
5681 /* Do the default thing. */;
5684 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5685 lhs, rhs, make_node (NOP_EXPR),
5686 /*overloaded_p=*/NULL);
5687 if (result == NULL_TREE)
5688 return error_mark_node;
5695 /* A binary op has been requested. Combine the old LHS
5696 value with the RHS producing the value we should actually
5697 store into the LHS. */
5699 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5700 lhs = stabilize_reference (lhs);
5701 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5702 if (newrhs == error_mark_node)
5704 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5705 TREE_TYPE (lhs), TREE_TYPE (rhs));
5706 return error_mark_node;
5709 /* Now it looks like a plain assignment. */
5710 modifycode = NOP_EXPR;
5712 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5713 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5716 /* The left-hand side must be an lvalue. */
5717 if (!lvalue_or_else (lhs, lv_assign))
5718 return error_mark_node;
5720 /* Warn about modifying something that is `const'. Don't warn if
5721 this is initialization. */
5722 if (modifycode != INIT_EXPR
5723 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5724 /* Functions are not modifiable, even though they are
5726 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5727 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5728 /* If it's an aggregate and any field is const, then it is
5729 effectively const. */
5730 || (CLASS_TYPE_P (lhstype)
5731 && C_TYPE_FIELDS_READONLY (lhstype))))
5732 readonly_error (lhs, "assignment", 0);
5734 /* If storing into a structure or union member, it has probably been
5735 given type `int'. Compute the type that would go with the actual
5736 amount of storage the member occupies. */
5738 if (TREE_CODE (lhs) == COMPONENT_REF
5739 && (TREE_CODE (lhstype) == INTEGER_TYPE
5740 || TREE_CODE (lhstype) == REAL_TYPE
5741 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5743 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5745 /* If storing in a field that is in actuality a short or narrower
5746 than one, we must store in the field in its actual type. */
5748 if (lhstype != TREE_TYPE (lhs))
5750 /* Avoid warnings converting integral types back into enums for
5752 if (TREE_CODE (lhstype) == INTEGER_TYPE
5753 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5755 if (TREE_SIDE_EFFECTS (lhs))
5756 lhs = stabilize_reference (lhs);
5759 lhs = copy_node (lhs);
5760 TREE_TYPE (lhs) = lhstype;
5764 /* Convert new value to destination type. */
5766 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5770 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5771 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5773 error ("incompatible types in assignment of %qT to %qT",
5774 TREE_TYPE (rhs), lhstype);
5775 return error_mark_node;
5778 /* Allow array assignment in compiler-generated code. */
5779 if (! DECL_ARTIFICIAL (current_function_decl))
5781 /* This routine is used for both initialization and assignment.
5782 Make sure the diagnostic message differentiates the context. */
5783 if (modifycode == INIT_EXPR)
5784 error ("array used as initializer");
5786 error ("invalid array assignment");
5787 return error_mark_node;
5790 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5791 ? 1 + (modifycode != INIT_EXPR): 0;
5792 return build_vec_init (lhs, NULL_TREE, newrhs,
5793 /*explicit_default_init_p=*/false,
5797 if (modifycode == INIT_EXPR)
5798 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5799 "initialization", NULL_TREE, 0);
5802 /* Avoid warnings on enum bit fields. */
5803 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5804 && TREE_CODE (lhstype) == INTEGER_TYPE)
5806 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5808 newrhs = convert_force (lhstype, newrhs, 0);
5811 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5813 if (TREE_CODE (newrhs) == CALL_EXPR
5814 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5815 newrhs = build_cplus_new (lhstype, newrhs);
5817 /* Can't initialize directly from a TARGET_EXPR, since that would
5818 cause the lhs to be constructed twice, and possibly result in
5819 accidental self-initialization. So we force the TARGET_EXPR to be
5820 expanded without a target. */
5821 if (TREE_CODE (newrhs) == TARGET_EXPR)
5822 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5823 TREE_OPERAND (newrhs, 0));
5826 if (newrhs == error_mark_node)
5827 return error_mark_node;
5829 if (c_dialect_objc () && flag_objc_gc)
5831 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5837 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5838 lhstype, lhs, newrhs);
5840 TREE_SIDE_EFFECTS (result) = 1;
5842 TREE_NO_WARNING (result) = 1;
5844 /* If we got the LHS in a different type for storing in,
5845 convert the result back to the nominal type of LHS
5846 so that the value we return always has the same type
5847 as the LHS argument. */
5849 if (olhstype == TREE_TYPE (result))
5853 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5854 TREE_NO_WARNING (result) = 1;
5857 return convert_for_assignment (olhstype, result, "assignment",
5862 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5864 if (processing_template_decl)
5865 return build_min_nt (MODOP_EXPR, lhs,
5866 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5868 if (modifycode != NOP_EXPR)
5870 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5871 make_node (modifycode),
5872 /*overloaded_p=*/NULL);
5875 TREE_NO_WARNING (rval) = 1;
5879 return build_modify_expr (lhs, modifycode, rhs);
5883 /* Get difference in deltas for different pointer to member function
5884 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5885 the conversion is invalid, the constant is zero. If
5886 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5887 If C_CAST_P is true this conversion is taking place as part of a
5890 Note that the naming of FROM and TO is kind of backwards; the return
5891 value is what we add to a TO in order to get a FROM. They are named
5892 this way because we call this function to find out how to convert from
5893 a pointer to member of FROM to a pointer to member of TO. */
5896 get_delta_difference (tree from, tree to,
5897 bool allow_inverse_p,
5904 /* Assume no conversion is required. */
5905 result = integer_zero_node;
5906 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5907 if (kind == bk_inaccessible || kind == bk_ambig)
5908 error (" in pointer to member function conversion");
5911 if (kind != bk_via_virtual)
5912 result = BINFO_OFFSET (binfo);
5915 tree virt_binfo = binfo_from_vbase (binfo);
5917 /* This is a reinterpret cast, we choose to do nothing. */
5918 if (allow_inverse_p)
5919 warning (0, "pointer to member cast via virtual base %qT",
5920 BINFO_TYPE (virt_binfo));
5922 error ("pointer to member conversion via virtual base %qT",
5923 BINFO_TYPE (virt_binfo));
5926 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5927 /* Pointer to member of incomplete class is permitted*/;
5928 else if (!allow_inverse_p)
5930 error_not_base_type (from, to);
5931 error (" in pointer to member conversion");
5935 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5938 if (kind != bk_via_virtual)
5939 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5942 /* This is a reinterpret cast, we choose to do nothing. */
5943 tree virt_binfo = binfo_from_vbase (binfo);
5945 warning (0, "pointer to member cast via virtual base %qT",
5946 BINFO_TYPE (virt_binfo));
5951 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5955 /* Return a constructor for the pointer-to-member-function TYPE using
5956 the other components as specified. */
5959 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5964 VEC(constructor_elt, gc) *v;
5966 /* Pull the FIELD_DECLs out of the type. */
5967 pfn_field = TYPE_FIELDS (type);
5968 delta_field = TREE_CHAIN (pfn_field);
5970 /* Make sure DELTA has the type we want. */
5971 delta = convert_and_check (delta_type_node, delta);
5973 /* Finish creating the initializer. */
5974 v = VEC_alloc(constructor_elt, gc, 2);
5975 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
5976 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
5977 u = build_constructor (type, v);
5978 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5979 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5980 TREE_STATIC (u) = (TREE_CONSTANT (u)
5981 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5983 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5988 /* Build a constructor for a pointer to member function. It can be
5989 used to initialize global variables, local variable, or used
5990 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5993 If FORCE is nonzero, then force this conversion, even if
5994 we would rather not do it. Usually set when using an explicit
5995 cast. A C-style cast is being processed iff C_CAST_P is true.
5997 Return error_mark_node, if something goes wrong. */
6000 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6006 if (error_operand_p (pfn))
6007 return error_mark_node;
6009 pfn_type = TREE_TYPE (pfn);
6010 to_type = build_ptrmemfunc_type (type);
6012 /* Handle multiple conversions of pointer to member functions. */
6013 if (TYPE_PTRMEMFUNC_P (pfn_type))
6015 tree delta = NULL_TREE;
6016 tree npfn = NULL_TREE;
6020 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6021 error ("invalid conversion to type %qT from type %qT",
6024 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6025 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6029 /* We don't have to do any conversion to convert a
6030 pointer-to-member to its own type. But, we don't want to
6031 just return a PTRMEM_CST if there's an explicit cast; that
6032 cast should make the expression an invalid template argument. */
6033 if (TREE_CODE (pfn) != PTRMEM_CST)
6035 if (same_type_p (to_type, pfn_type))
6037 else if (integer_zerop (n))
6038 return build_reinterpret_cast (to_type, pfn);
6041 if (TREE_SIDE_EFFECTS (pfn))
6042 pfn = save_expr (pfn);
6044 /* Obtain the function pointer and the current DELTA. */
6045 if (TREE_CODE (pfn) == PTRMEM_CST)
6046 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6049 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6050 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6053 /* Just adjust the DELTA field. */
6054 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6055 (TREE_TYPE (delta), ptrdiff_type_node));
6056 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6057 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6058 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6059 return build_ptrmemfunc1 (to_type, delta, npfn);
6062 /* Handle null pointer to member function conversions. */
6063 if (integer_zerop (pfn))
6065 pfn = build_c_cast (type, integer_zero_node);
6066 return build_ptrmemfunc1 (to_type,
6071 if (type_unknown_p (pfn))
6072 return instantiate_type (type, pfn, tf_warning_or_error);
6074 fn = TREE_OPERAND (pfn, 0);
6075 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6076 /* In a template, we will have preserved the
6078 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6079 return make_ptrmem_cst (to_type, fn);
6082 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6085 ??? There is no consistency as to the types returned for the above
6086 values. Some code acts as if it were a sizetype and some as if it were
6087 integer_type_node. */
6090 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6092 tree type = TREE_TYPE (cst);
6093 tree fn = PTRMEM_CST_MEMBER (cst);
6094 tree ptr_class, fn_class;
6096 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6098 /* The class that the function belongs to. */
6099 fn_class = DECL_CONTEXT (fn);
6101 /* The class that we're creating a pointer to member of. */
6102 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6104 /* First, calculate the adjustment to the function's class. */
6105 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6108 if (!DECL_VIRTUAL_P (fn))
6109 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6112 /* If we're dealing with a virtual function, we have to adjust 'this'
6113 again, to point to the base which provides the vtable entry for
6114 fn; the call will do the opposite adjustment. */
6115 tree orig_class = DECL_CONTEXT (fn);
6116 tree binfo = binfo_or_else (orig_class, fn_class);
6117 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6118 *delta, BINFO_OFFSET (binfo));
6119 *delta = fold_if_not_in_template (*delta);
6121 /* We set PFN to the vtable offset at which the function can be
6122 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6123 case delta is shifted left, and then incremented). */
6124 *pfn = DECL_VINDEX (fn);
6125 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6126 TYPE_SIZE_UNIT (vtable_entry_type));
6127 *pfn = fold_if_not_in_template (*pfn);
6129 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6131 case ptrmemfunc_vbit_in_pfn:
6132 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6134 *pfn = fold_if_not_in_template (*pfn);
6137 case ptrmemfunc_vbit_in_delta:
6138 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6139 *delta, integer_one_node);
6140 *delta = fold_if_not_in_template (*delta);
6141 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6142 *delta, integer_one_node);
6143 *delta = fold_if_not_in_template (*delta);
6150 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6151 *pfn = fold_if_not_in_template (*pfn);
6155 /* Return an expression for PFN from the pointer-to-member function
6159 pfn_from_ptrmemfunc (tree t)
6161 if (TREE_CODE (t) == PTRMEM_CST)
6166 expand_ptrmemfunc_cst (t, &delta, &pfn);
6171 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6174 /* Convert value RHS to type TYPE as preparation for an assignment to
6175 an lvalue of type TYPE. ERRTYPE is a string to use in error
6176 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6177 are doing the conversion in order to pass the PARMNUMth argument of
6181 convert_for_assignment (tree type, tree rhs,
6182 const char *errtype, tree fndecl, int parmnum)
6185 enum tree_code coder;
6187 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6188 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6189 rhs = TREE_OPERAND (rhs, 0);
6191 rhstype = TREE_TYPE (rhs);
6192 coder = TREE_CODE (rhstype);
6194 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6195 && vector_types_convertible_p (type, rhstype))
6196 return convert (type, rhs);
6198 if (rhs == error_mark_node || rhstype == error_mark_node)
6199 return error_mark_node;
6200 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6201 return error_mark_node;
6203 /* The RHS of an assignment cannot have void type. */
6204 if (coder == VOID_TYPE)
6206 error ("void value not ignored as it ought to be");
6207 return error_mark_node;
6210 /* Simplify the RHS if possible. */
6211 if (TREE_CODE (rhs) == CONST_DECL)
6212 rhs = DECL_INITIAL (rhs);
6214 if (c_dialect_objc ())
6217 tree rname = fndecl;
6219 if (!strcmp (errtype, "assignment"))
6221 else if (!strcmp (errtype, "initialization"))
6225 tree selector = objc_message_selector ();
6229 if (selector && parmno > 1)
6236 if (objc_compare_types (type, rhstype, parmno, rname))
6237 return convert (type, rhs);
6242 The expression is implicitly converted (clause _conv_) to the
6243 cv-unqualified type of the left operand.
6245 We allow bad conversions here because by the time we get to this point
6246 we are committed to doing the conversion. If we end up doing a bad
6247 conversion, convert_like will complain. */
6248 if (!can_convert_arg_bad (type, rhstype, rhs))
6250 /* When -Wno-pmf-conversions is use, we just silently allow
6251 conversions from pointers-to-members to plain pointers. If
6252 the conversion doesn't work, cp_convert will complain. */
6254 && TYPE_PTR_P (type)
6255 && TYPE_PTRMEMFUNC_P (rhstype))
6256 rhs = cp_convert (strip_top_quals (type), rhs);
6259 /* If the right-hand side has unknown type, then it is an
6260 overloaded function. Call instantiate_type to get error
6262 if (rhstype == unknown_type_node)
6263 instantiate_type (type, rhs, tf_warning_or_error);
6265 error ("cannot convert %qT to %qT for argument %qP to %qD",
6266 rhstype, type, parmnum, fndecl);
6268 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6269 return error_mark_node;
6272 if (warn_missing_format_attribute)
6274 const enum tree_code codel = TREE_CODE (type);
6275 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6277 && check_missing_format_attribute (type, rhstype))
6278 warning (OPT_Wmissing_format_attribute,
6279 "%s might be a candidate for a format attribute",
6283 return perform_implicit_conversion (strip_top_quals (type), rhs);
6286 /* Convert RHS to be of type TYPE.
6287 If EXP is nonzero, it is the target of the initialization.
6288 ERRTYPE is a string to use in error messages.
6290 Two major differences between the behavior of
6291 `convert_for_assignment' and `convert_for_initialization'
6292 are that references are bashed in the former, while
6293 copied in the latter, and aggregates are assigned in
6294 the former (operator=) while initialized in the
6297 If using constructor make sure no conversion operator exists, if one does
6298 exist, an ambiguity exists.
6300 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6303 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6304 const char *errtype, tree fndecl, int parmnum)
6306 enum tree_code codel = TREE_CODE (type);
6308 enum tree_code coder;
6310 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6311 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6312 if (TREE_CODE (rhs) == NOP_EXPR
6313 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6314 && codel != REFERENCE_TYPE)
6315 rhs = TREE_OPERAND (rhs, 0);
6317 if (type == error_mark_node
6318 || rhs == error_mark_node
6319 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6320 return error_mark_node;
6322 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6323 && TREE_CODE (type) != ARRAY_TYPE
6324 && (TREE_CODE (type) != REFERENCE_TYPE
6325 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6326 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6327 && (TREE_CODE (type) != REFERENCE_TYPE
6328 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6329 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6330 rhs = decay_conversion (rhs);
6332 rhstype = TREE_TYPE (rhs);
6333 coder = TREE_CODE (rhstype);
6335 if (coder == ERROR_MARK)
6336 return error_mark_node;
6338 /* We accept references to incomplete types, so we can
6339 return here before checking if RHS is of complete type. */
6341 if (codel == REFERENCE_TYPE)
6343 /* This should eventually happen in convert_arguments. */
6344 int savew = 0, savee = 0;
6347 savew = warningcount, savee = errorcount;
6348 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6352 if (warningcount > savew)
6353 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6354 else if (errorcount > savee)
6355 error ("in passing argument %P of %q+D", parmnum, fndecl);
6361 exp = require_complete_type (exp);
6362 if (exp == error_mark_node)
6363 return error_mark_node;
6365 rhstype = non_reference (rhstype);
6367 type = complete_type (type);
6369 if (IS_AGGR_TYPE (type))
6370 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6372 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6375 /* If RETVAL is the address of, or a reference to, a local variable or
6376 temporary give an appropriate warning. */
6379 maybe_warn_about_returning_address_of_local (tree retval)
6381 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6382 tree whats_returned = retval;
6386 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6387 whats_returned = TREE_OPERAND (whats_returned, 1);
6388 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6389 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6390 || TREE_CODE (whats_returned) == NOP_EXPR)
6391 whats_returned = TREE_OPERAND (whats_returned, 0);
6396 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6398 whats_returned = TREE_OPERAND (whats_returned, 0);
6400 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6402 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6403 || TREE_CODE (whats_returned) == TARGET_EXPR)
6405 warning (0, "returning reference to temporary");
6408 if (TREE_CODE (whats_returned) == VAR_DECL
6409 && DECL_NAME (whats_returned)
6410 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6412 warning (0, "reference to non-lvalue returned");
6417 while (TREE_CODE (whats_returned) == COMPONENT_REF
6418 || TREE_CODE (whats_returned) == ARRAY_REF)
6419 whats_returned = TREE_OPERAND (whats_returned, 0);
6421 if (DECL_P (whats_returned)
6422 && DECL_NAME (whats_returned)
6423 && DECL_FUNCTION_SCOPE_P (whats_returned)
6424 && !(TREE_STATIC (whats_returned)
6425 || TREE_PUBLIC (whats_returned)))
6427 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6428 warning (0, "reference to local variable %q+D returned",
6431 warning (0, "address of local variable %q+D returned",
6437 /* Check that returning RETVAL from the current function is valid.
6438 Return an expression explicitly showing all conversions required to
6439 change RETVAL into the function return type, and to assign it to
6440 the DECL_RESULT for the function. Set *NO_WARNING to true if
6441 code reaches end of non-void function warning shouldn't be issued
6442 on this RETURN_EXPR. */
6445 check_return_expr (tree retval, bool *no_warning)
6448 /* The type actually returned by the function, after any
6451 int fn_returns_value_p;
6453 *no_warning = false;
6455 /* A `volatile' function is one that isn't supposed to return, ever.
6456 (This is a G++ extension, used to get better code for functions
6457 that call the `volatile' function.) */
6458 if (TREE_THIS_VOLATILE (current_function_decl))
6459 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6461 /* Check for various simple errors. */
6462 if (DECL_DESTRUCTOR_P (current_function_decl))
6465 error ("returning a value from a destructor");
6468 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6470 if (in_function_try_handler)
6471 /* If a return statement appears in a handler of the
6472 function-try-block of a constructor, the program is ill-formed. */
6473 error ("cannot return from a handler of a function-try-block of a constructor");
6475 /* You can't return a value from a constructor. */
6476 error ("returning a value from a constructor");
6480 if (processing_template_decl)
6482 current_function_returns_value = 1;
6486 /* When no explicit return-value is given in a function with a named
6487 return value, the named return value is used. */
6488 result = DECL_RESULT (current_function_decl);
6489 valtype = TREE_TYPE (result);
6490 gcc_assert (valtype != NULL_TREE);
6491 fn_returns_value_p = !VOID_TYPE_P (valtype);
6492 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6495 /* Check for a return statement with no return value in a function
6496 that's supposed to return a value. */
6497 if (!retval && fn_returns_value_p)
6499 pedwarn ("return-statement with no value, in function returning %qT",
6501 /* Clear this, so finish_function won't say that we reach the
6502 end of a non-void function (which we don't, we gave a
6504 current_function_returns_null = 0;
6505 /* And signal caller that TREE_NO_WARNING should be set on the
6506 RETURN_EXPR to avoid control reaches end of non-void function
6507 warnings in tree-cfg.c. */
6510 /* Check for a return statement with a value in a function that
6511 isn't supposed to return a value. */
6512 else if (retval && !fn_returns_value_p)
6514 if (VOID_TYPE_P (TREE_TYPE (retval)))
6515 /* You can return a `void' value from a function of `void'
6516 type. In that case, we have to evaluate the expression for
6517 its side-effects. */
6518 finish_expr_stmt (retval);
6520 pedwarn ("return-statement with a value, in function "
6521 "returning 'void'");
6523 current_function_returns_null = 1;
6525 /* There's really no value to return, after all. */
6529 /* Remember that this function can sometimes return without a
6531 current_function_returns_null = 1;
6533 /* Remember that this function did return a value. */
6534 current_function_returns_value = 1;
6536 /* Check for erroneous operands -- but after giving ourselves a
6537 chance to provide an error about returning a value from a void
6539 if (error_operand_p (retval))
6541 current_function_return_value = error_mark_node;
6542 return error_mark_node;
6545 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6546 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6547 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6548 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6550 && null_ptr_cst_p (retval))
6551 warning (0, "%<operator new%> must not return NULL unless it is "
6552 "declared %<throw()%> (or -fcheck-new is in effect)");
6554 /* Effective C++ rule 15. See also start_function. */
6556 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6560 /* The function return type must be a reference to the current
6562 if (TREE_CODE (valtype) == REFERENCE_TYPE
6563 && same_type_ignoring_top_level_qualifiers_p
6564 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6566 /* Returning '*this' is obviously OK. */
6567 if (retval == current_class_ref)
6569 /* If we are calling a function whose return type is the same of
6570 the current class reference, it is ok. */
6571 else if (TREE_CODE (retval) == INDIRECT_REF
6572 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6577 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6580 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6582 [...] For a function with a class return type, if the expression
6583 in the return statement is the name of a local object, and the cv-
6584 unqualified type of the local object is the same as the function
6585 return type, an implementation is permitted to omit creating the tem-
6586 porary object to hold the function return value [...]
6588 So, if this is a value-returning function that always returns the same
6589 local variable, remember it.
6591 It might be nice to be more flexible, and choose the first suitable
6592 variable even if the function sometimes returns something else, but
6593 then we run the risk of clobbering the variable we chose if the other
6594 returned expression uses the chosen variable somehow. And people expect
6595 this restriction, anyway. (jason 2000-11-19)
6597 See finish_function and finalize_nrv for the rest of this optimization. */
6599 if (fn_returns_value_p && flag_elide_constructors)
6601 if (retval != NULL_TREE
6602 && (current_function_return_value == NULL_TREE
6603 || current_function_return_value == retval)
6604 && TREE_CODE (retval) == VAR_DECL
6605 && DECL_CONTEXT (retval) == current_function_decl
6606 && ! TREE_STATIC (retval)
6607 && (DECL_ALIGN (retval)
6608 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6609 && same_type_p ((TYPE_MAIN_VARIANT
6610 (TREE_TYPE (retval))),
6612 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6613 current_function_return_value = retval;
6615 current_function_return_value = error_mark_node;
6618 /* We don't need to do any conversions when there's nothing being
6623 /* Do any required conversions. */
6624 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6625 /* No conversions are required. */
6629 /* The type the function is declared to return. */
6630 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6632 /* The functype's return type will have been set to void, if it
6633 was an incomplete type. Just treat this as 'return;' */
6634 if (VOID_TYPE_P (functype))
6635 return error_mark_node;
6637 /* First convert the value to the function's return type, then
6638 to the type of return value's location to handle the
6639 case that functype is smaller than the valtype. */
6640 retval = convert_for_initialization
6641 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6642 "return", NULL_TREE, 0);
6643 retval = convert (valtype, retval);
6645 /* If the conversion failed, treat this just like `return;'. */
6646 if (retval == error_mark_node)
6648 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6649 else if (! current_function_returns_struct
6650 && TREE_CODE (retval) == TARGET_EXPR
6651 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6652 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6653 TREE_OPERAND (retval, 0));
6655 maybe_warn_about_returning_address_of_local (retval);
6658 /* Actually copy the value returned into the appropriate location. */
6659 if (retval && retval != result)
6660 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6666 /* Returns nonzero if the pointer-type FROM can be converted to the
6667 pointer-type TO via a qualification conversion. If CONSTP is -1,
6668 then we return nonzero if the pointers are similar, and the
6669 cv-qualification signature of FROM is a proper subset of that of TO.
6671 If CONSTP is positive, then all outer pointers have been
6675 comp_ptr_ttypes_real (tree to, tree from, int constp)
6677 bool to_more_cv_qualified = false;
6679 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6681 if (TREE_CODE (to) != TREE_CODE (from))
6684 if (TREE_CODE (from) == OFFSET_TYPE
6685 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6686 TYPE_OFFSET_BASETYPE (to)))
6689 /* Const and volatile mean something different for function types,
6690 so the usual checks are not appropriate. */
6691 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6693 /* In Objective-C++, some types may have been 'volatilized' by
6694 the compiler for EH; when comparing them here, the volatile
6695 qualification must be ignored. */
6696 bool objc_quals_match = objc_type_quals_match (to, from);
6698 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6701 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6705 to_more_cv_qualified = true;
6709 constp &= TYPE_READONLY (to);
6712 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6713 return ((constp >= 0 || to_more_cv_qualified)
6714 && same_type_ignoring_top_level_qualifiers_p (to, from));
6718 /* When comparing, say, char ** to char const **, this function takes
6719 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6720 types to this function. */
6723 comp_ptr_ttypes (tree to, tree from)
6725 return comp_ptr_ttypes_real (to, from, 1);
6728 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6729 type or inheritance-related types, regardless of cv-quals. */
6732 ptr_reasonably_similar (tree to, tree from)
6734 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6736 /* Any target type is similar enough to void. */
6737 if (TREE_CODE (to) == VOID_TYPE
6738 || TREE_CODE (from) == VOID_TYPE)
6741 if (TREE_CODE (to) != TREE_CODE (from))
6744 if (TREE_CODE (from) == OFFSET_TYPE
6745 && comptypes (TYPE_OFFSET_BASETYPE (to),
6746 TYPE_OFFSET_BASETYPE (from),
6747 COMPARE_BASE | COMPARE_DERIVED))
6750 if (TREE_CODE (to) == VECTOR_TYPE
6751 && vector_types_convertible_p (to, from))
6754 if (TREE_CODE (to) == INTEGER_TYPE
6755 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6758 if (TREE_CODE (to) == FUNCTION_TYPE)
6761 if (TREE_CODE (to) != POINTER_TYPE)
6763 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6764 COMPARE_BASE | COMPARE_DERIVED);
6768 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6769 pointer-to-member types) are the same, ignoring cv-qualification at
6773 comp_ptr_ttypes_const (tree to, tree from)
6775 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6777 if (TREE_CODE (to) != TREE_CODE (from))
6780 if (TREE_CODE (from) == OFFSET_TYPE
6781 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6782 TYPE_OFFSET_BASETYPE (to)))
6785 if (TREE_CODE (to) != POINTER_TYPE)
6786 return same_type_ignoring_top_level_qualifiers_p (to, from);
6790 /* Returns the type qualifiers for this type, including the qualifiers on the
6791 elements for an array type. */
6794 cp_type_quals (tree type)
6796 type = strip_array_types (type);
6797 if (type == error_mark_node)
6798 return TYPE_UNQUALIFIED;
6799 return TYPE_QUALS (type);
6802 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6806 cp_type_readonly (tree type)
6808 type = strip_array_types (type);
6809 return TYPE_READONLY (type);
6812 /* Returns nonzero if the TYPE contains a mutable member. */
6815 cp_has_mutable_p (tree type)
6817 type = strip_array_types (type);
6819 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6822 /* Apply the TYPE_QUALS to the new DECL. */
6824 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6826 tree type = TREE_TYPE (decl);
6828 if (type == error_mark_node)
6831 if (TREE_CODE (type) == FUNCTION_TYPE
6832 && type_quals != TYPE_UNQUALIFIED)
6834 /* This was an error in C++98 (cv-qualifiers cannot be added to
6835 a function type), but DR 295 makes the code well-formed by
6836 dropping the extra qualifiers. */
6839 tree bad_type = build_qualified_type (type, type_quals);
6840 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6844 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6848 /* Avoid setting TREE_READONLY incorrectly. */
6849 if (/* If the object has a constructor, the constructor may modify
6851 TYPE_NEEDS_CONSTRUCTING (type)
6852 /* If the type isn't complete, we don't know yet if it will need
6854 || !COMPLETE_TYPE_P (type)
6855 /* If the type has a mutable component, that component might be
6857 || TYPE_HAS_MUTABLE_P (type))
6858 type_quals &= ~TYPE_QUAL_CONST;
6860 c_apply_type_quals_to_decl (type_quals, decl);
6863 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6864 exemplar types such that casting T1 to T2 is casting away constness
6865 if and only if there is no implicit conversion from T1 to T2. */
6868 casts_away_constness_r (tree *t1, tree *t2)
6873 /* [expr.const.cast]
6875 For multi-level pointer to members and multi-level mixed pointers
6876 and pointers to members (conv.qual), the "member" aspect of a
6877 pointer to member level is ignored when determining if a const
6878 cv-qualifier has been cast away. */
6879 /* [expr.const.cast]
6881 For two pointer types:
6883 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6884 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6887 casting from X1 to X2 casts away constness if, for a non-pointer
6888 type T there does not exist an implicit conversion (clause
6891 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6895 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6896 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6897 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6899 *t1 = cp_build_qualified_type (void_type_node,
6900 cp_type_quals (*t1));
6901 *t2 = cp_build_qualified_type (void_type_node,
6902 cp_type_quals (*t2));
6906 quals1 = cp_type_quals (*t1);
6907 quals2 = cp_type_quals (*t2);
6909 if (TYPE_PTRMEM_P (*t1))
6910 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6912 *t1 = TREE_TYPE (*t1);
6913 if (TYPE_PTRMEM_P (*t2))
6914 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6916 *t2 = TREE_TYPE (*t2);
6918 casts_away_constness_r (t1, t2);
6919 *t1 = build_pointer_type (*t1);
6920 *t2 = build_pointer_type (*t2);
6921 *t1 = cp_build_qualified_type (*t1, quals1);
6922 *t2 = cp_build_qualified_type (*t2, quals2);
6925 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6929 casts_away_constness (tree t1, tree t2)
6931 if (TREE_CODE (t2) == REFERENCE_TYPE)
6933 /* [expr.const.cast]
6935 Casting from an lvalue of type T1 to an lvalue of type T2
6936 using a reference cast casts away constness if a cast from an
6937 rvalue of type "pointer to T1" to the type "pointer to T2"
6938 casts away constness. */
6939 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6940 return casts_away_constness (build_pointer_type (t1),
6941 build_pointer_type (TREE_TYPE (t2)));
6944 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6945 /* [expr.const.cast]
6947 Casting from an rvalue of type "pointer to data member of X
6948 of type T1" to the type "pointer to data member of Y of type
6949 T2" casts away constness if a cast from an rvalue of type
6950 "pointer to T1" to the type "pointer to T2" casts away
6952 return casts_away_constness
6953 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6954 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6956 /* Casting away constness is only something that makes sense for
6957 pointer or reference types. */
6958 if (TREE_CODE (t1) != POINTER_TYPE
6959 || TREE_CODE (t2) != POINTER_TYPE)
6962 /* Top-level qualifiers don't matter. */
6963 t1 = TYPE_MAIN_VARIANT (t1);
6964 t2 = TYPE_MAIN_VARIANT (t2);
6965 casts_away_constness_r (&t1, &t2);
6966 if (!can_convert (t2, t1))
6972 /* If T is a REFERENCE_TYPE return the type to which T refers.
6973 Otherwise, return T itself. */
6976 non_reference (tree t)
6978 if (TREE_CODE (t) == REFERENCE_TYPE)
6984 /* Return nonzero if REF is an lvalue valid for this language;
6985 otherwise, print an error message and return zero. USE says
6986 how the lvalue is being used and so selects the error message. */
6989 lvalue_or_else (tree ref, enum lvalue_use use)
6991 int win = lvalue_p (ref);