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"
47 static tree pfn_from_ptrmemfunc (tree);
48 static tree convert_for_assignment (tree, tree, const char *, tree, int);
49 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
50 static tree rationalize_conditional_expr (enum tree_code, tree);
51 static int comp_ptr_ttypes_real (tree, tree, int);
52 static bool comp_except_types (tree, tree, bool);
53 static bool comp_array_types (tree, tree, bool);
54 static tree common_base_type (tree, tree);
55 static tree pointer_diff (tree, tree, tree);
56 static tree get_delta_difference (tree, tree, bool, bool);
57 static void casts_away_constness_r (tree *, tree *);
58 static bool casts_away_constness (tree, tree);
59 static void maybe_warn_about_returning_address_of_local (tree);
60 static tree lookup_destructor (tree, tree, tree);
61 static tree convert_arguments (tree, tree, tree, int);
63 /* Do `exp = require_complete_type (exp);' to make sure exp
64 does not have an incomplete type. (That includes void types.)
65 Returns the error_mark_node if the VALUE does not have
66 complete type when this function returns. */
69 require_complete_type (tree value)
73 if (processing_template_decl || value == error_mark_node)
76 if (TREE_CODE (value) == OVERLOAD)
77 type = unknown_type_node;
79 type = TREE_TYPE (value);
81 if (type == error_mark_node)
82 return error_mark_node;
84 /* First, detect a valid value with a complete type. */
85 if (COMPLETE_TYPE_P (type))
88 if (complete_type_or_else (type, value))
91 return error_mark_node;
94 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
95 a template instantiation, do the instantiation. Returns TYPE,
96 whether or not it could be completed, unless something goes
97 horribly wrong, in which case the error_mark_node is returned. */
100 complete_type (tree type)
102 if (type == NULL_TREE)
103 /* Rather than crash, we return something sure to cause an error
105 return error_mark_node;
107 if (type == error_mark_node || COMPLETE_TYPE_P (type))
109 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
111 tree t = complete_type (TREE_TYPE (type));
112 unsigned int needs_constructing, has_nontrivial_dtor;
113 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
116 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
118 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
119 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
121 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
122 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
125 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
126 instantiate_class_template (TYPE_MAIN_VARIANT (type));
131 /* Like complete_type, but issue an error if the TYPE cannot be completed.
132 VALUE is used for informative diagnostics.
133 Returns NULL_TREE if the type cannot be made complete. */
136 complete_type_or_else (tree type, tree value)
138 type = complete_type (type);
139 if (type == error_mark_node)
140 /* We already issued an error. */
142 else if (!COMPLETE_TYPE_P (type))
144 cxx_incomplete_type_diagnostic (value, type, 0);
151 /* Return truthvalue of whether type of EXP is instantiated. */
154 type_unknown_p (tree exp)
156 return (TREE_CODE (exp) == TREE_LIST
157 || TREE_TYPE (exp) == unknown_type_node);
161 /* Return the common type of two parameter lists.
162 We assume that comptypes has already been done and returned 1;
163 if that isn't so, this may crash.
165 As an optimization, free the space we allocate if the parameter
166 lists are already common. */
169 commonparms (tree p1, tree p2)
171 tree oldargs = p1, newargs, n;
175 len = list_length (p1);
176 newargs = tree_last (p1);
178 if (newargs == void_list_node)
187 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
192 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
194 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
196 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
199 else if (! TREE_PURPOSE (p1))
201 if (TREE_PURPOSE (p2))
203 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
209 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
211 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
213 if (TREE_VALUE (p1) != TREE_VALUE (p2))
216 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
219 TREE_VALUE (n) = TREE_VALUE (p1);
227 /* Given a type, perhaps copied for a typedef,
228 find the "original" version of it. */
230 original_type (tree t)
232 int quals = cp_type_quals (t);
233 while (t != error_mark_node
234 && TYPE_NAME (t) != NULL_TREE)
236 tree x = TYPE_NAME (t);
237 if (TREE_CODE (x) != TYPE_DECL)
239 x = DECL_ORIGINAL_TYPE (x);
244 return cp_build_qualified_type (t, quals);
247 /* T1 and T2 are arithmetic or enumeration types. Return the type
248 that will result from the "usual arithmetic conversions" on T1 and
249 T2 as described in [expr]. */
252 type_after_usual_arithmetic_conversions (tree t1, tree t2)
254 enum tree_code code1 = TREE_CODE (t1);
255 enum tree_code code2 = TREE_CODE (t2);
258 /* FIXME: Attributes. */
259 gcc_assert (ARITHMETIC_TYPE_P (t1)
260 || TREE_CODE (t1) == COMPLEX_TYPE
261 || TREE_CODE (t1) == VECTOR_TYPE
262 || TREE_CODE (t1) == ENUMERAL_TYPE);
263 gcc_assert (ARITHMETIC_TYPE_P (t2)
264 || TREE_CODE (t2) == COMPLEX_TYPE
265 || TREE_CODE (t2) == VECTOR_TYPE
266 || TREE_CODE (t2) == ENUMERAL_TYPE);
268 /* In what follows, we slightly generalize the rules given in [expr] so
269 as to deal with `long long' and `complex'. First, merge the
271 attributes = (*targetm.merge_type_attributes) (t1, t2);
273 /* If one type is complex, form the common type of the non-complex
274 components, then make that complex. Use T1 or T2 if it is the
276 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
278 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
279 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
281 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
283 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
284 return build_type_attribute_variant (t1, attributes);
285 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
286 return build_type_attribute_variant (t2, attributes);
288 return build_type_attribute_variant (build_complex_type (subtype),
292 if (code1 == VECTOR_TYPE)
294 /* When we get here we should have two vectors of the same size.
295 Just prefer the unsigned one if present. */
296 if (TYPE_UNSIGNED (t1))
297 return build_type_attribute_variant (t1, attributes);
299 return build_type_attribute_variant (t2, attributes);
302 /* If only one is real, use it as the result. */
303 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
304 return build_type_attribute_variant (t1, attributes);
305 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
306 return build_type_attribute_variant (t2, attributes);
308 /* Perform the integral promotions. */
309 if (code1 != REAL_TYPE)
311 t1 = type_promotes_to (t1);
312 t2 = type_promotes_to (t2);
315 /* Both real or both integers; use the one with greater precision. */
316 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
317 return build_type_attribute_variant (t1, attributes);
318 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
319 return build_type_attribute_variant (t2, attributes);
321 /* The types are the same; no need to do anything fancy. */
322 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
323 return build_type_attribute_variant (t1, attributes);
325 if (code1 != REAL_TYPE)
327 /* If one is unsigned long long, then convert the other to unsigned
329 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
330 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
331 return build_type_attribute_variant (long_long_unsigned_type_node,
333 /* If one is a long long, and the other is an unsigned long, and
334 long long can represent all the values of an unsigned long, then
335 convert to a long long. Otherwise, convert to an unsigned long
336 long. Otherwise, if either operand is long long, convert the
339 Since we're here, we know the TYPE_PRECISION is the same;
340 therefore converting to long long cannot represent all the values
341 of an unsigned long, so we choose unsigned long long in that
343 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
344 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
346 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
347 ? long_long_unsigned_type_node
348 : long_long_integer_type_node);
349 return build_type_attribute_variant (t, attributes);
352 /* Go through the same procedure, but for longs. */
353 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
354 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
355 return build_type_attribute_variant (long_unsigned_type_node,
357 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
358 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
360 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
361 ? long_unsigned_type_node : long_integer_type_node);
362 return build_type_attribute_variant (t, attributes);
364 /* Otherwise prefer the unsigned one. */
365 if (TYPE_UNSIGNED (t1))
366 return build_type_attribute_variant (t1, attributes);
368 return build_type_attribute_variant (t2, attributes);
372 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
373 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
374 return build_type_attribute_variant (long_double_type_node,
376 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
377 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
378 return build_type_attribute_variant (double_type_node,
380 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
381 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
382 return build_type_attribute_variant (float_type_node,
385 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
386 the standard C++ floating-point types. Logic earlier in this
387 function has already eliminated the possibility that
388 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
389 compelling reason to choose one or the other. */
390 return build_type_attribute_variant (t1, attributes);
394 /* Subroutine of composite_pointer_type to implement the recursive
395 case. See that function for documentation fo the parameters. */
398 composite_pointer_type_r (tree t1, tree t2, const char* location)
405 /* Determine the types pointed to by T1 and T2. */
406 if (TREE_CODE (t1) == POINTER_TYPE)
408 pointee1 = TREE_TYPE (t1);
409 pointee2 = TREE_TYPE (t2);
413 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
414 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
419 Otherwise, the composite pointer type is a pointer type
420 similar (_conv.qual_) to the type of one of the operands,
421 with a cv-qualification signature (_conv.qual_) that is the
422 union of the cv-qualification signatures of the operand
424 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
425 result_type = pointee1;
426 else if ((TREE_CODE (pointee1) == POINTER_TYPE
427 && TREE_CODE (pointee2) == POINTER_TYPE)
428 || (TYPE_PTR_TO_MEMBER_P (pointee1)
429 && TYPE_PTR_TO_MEMBER_P (pointee2)))
430 result_type = composite_pointer_type_r (pointee1, pointee2, location);
433 pedwarn ("%s between distinct pointer types %qT and %qT "
436 result_type = void_type_node;
438 result_type = cp_build_qualified_type (result_type,
439 (cp_type_quals (pointee1)
440 | cp_type_quals (pointee2)));
441 /* If the original types were pointers to members, so is the
443 if (TYPE_PTR_TO_MEMBER_P (t1))
445 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
446 TYPE_PTRMEM_CLASS_TYPE (t2)))
447 pedwarn ("%s between distinct pointer types %qT and %qT "
450 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
454 result_type = build_pointer_type (result_type);
456 /* Merge the attributes. */
457 attributes = (*targetm.merge_type_attributes) (t1, t2);
458 return build_type_attribute_variant (result_type, attributes);
461 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
462 ARG1 and ARG2 are the values with those types. The LOCATION is a
463 string describing the current location, in case an error occurs.
465 This routine also implements the computation of a common type for
466 pointers-to-members as per [expr.eq]. */
469 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
470 const char* location)
477 If one operand is a null pointer constant, the composite pointer
478 type is the type of the other operand. */
479 if (null_ptr_cst_p (arg1))
481 if (null_ptr_cst_p (arg2))
488 If one of the operands has type "pointer to cv1 void*", then
489 the other has type "pointer to cv2T", and the composite pointer
490 type is "pointer to cv12 void", where cv12 is the union of cv1
493 If either type is a pointer to void, make sure it is T1. */
494 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
502 /* Now, if T1 is a pointer to void, merge the qualifiers. */
503 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
508 if (pedantic && TYPE_PTRFN_P (t2))
509 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
510 "and pointer-to-function", location);
512 = cp_build_qualified_type (void_type_node,
513 (cp_type_quals (TREE_TYPE (t1))
514 | cp_type_quals (TREE_TYPE (t2))));
515 result_type = build_pointer_type (result_type);
516 /* Merge the attributes. */
517 attributes = (*targetm.merge_type_attributes) (t1, t2);
518 return build_type_attribute_variant (result_type, attributes);
521 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
522 && TREE_CODE (t2) == POINTER_TYPE)
524 if (objc_compare_types (t1, t2, -3, NULL_TREE))
528 /* [expr.eq] permits the application of a pointer conversion to
529 bring the pointers to a common type. */
530 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
531 && CLASS_TYPE_P (TREE_TYPE (t1))
532 && CLASS_TYPE_P (TREE_TYPE (t2))
533 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
536 class1 = TREE_TYPE (t1);
537 class2 = TREE_TYPE (t2);
539 if (DERIVED_FROM_P (class1, class2))
540 t2 = (build_pointer_type
541 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
542 else if (DERIVED_FROM_P (class2, class1))
543 t1 = (build_pointer_type
544 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
547 error ("%s between distinct pointer types %qT and %qT "
548 "lacks a cast", location, t1, t2);
549 return error_mark_node;
552 /* [expr.eq] permits the application of a pointer-to-member
553 conversion to change the class type of one of the types. */
554 else if (TYPE_PTR_TO_MEMBER_P (t1)
555 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
556 TYPE_PTRMEM_CLASS_TYPE (t2)))
558 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
559 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
561 if (DERIVED_FROM_P (class1, class2))
562 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
563 else if (DERIVED_FROM_P (class2, class1))
564 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
567 error ("%s between distinct pointer-to-member types %qT and %qT "
568 "lacks a cast", location, t1, t2);
569 return error_mark_node;
573 return composite_pointer_type_r (t1, t2, location);
576 /* Return the merged type of two types.
577 We assume that comptypes has already been done and returned 1;
578 if that isn't so, this may crash.
580 This just combines attributes and default arguments; any other
581 differences would cause the two types to compare unalike. */
584 merge_types (tree t1, tree t2)
586 enum tree_code code1;
587 enum tree_code code2;
590 /* Save time if the two types are the same. */
593 if (original_type (t1) == original_type (t2))
596 /* If one type is nonsense, use the other. */
597 if (t1 == error_mark_node)
599 if (t2 == error_mark_node)
602 /* Merge the attributes. */
603 attributes = (*targetm.merge_type_attributes) (t1, t2);
605 if (TYPE_PTRMEMFUNC_P (t1))
606 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
607 if (TYPE_PTRMEMFUNC_P (t2))
608 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
610 code1 = TREE_CODE (t1);
611 code2 = TREE_CODE (t2);
617 /* For two pointers, do this recursively on the target type. */
619 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
620 int quals = cp_type_quals (t1);
622 if (code1 == POINTER_TYPE)
623 t1 = build_pointer_type (target);
625 t1 = build_reference_type (target);
626 t1 = build_type_attribute_variant (t1, attributes);
627 t1 = cp_build_qualified_type (t1, quals);
629 if (TREE_CODE (target) == METHOD_TYPE)
630 t1 = build_ptrmemfunc_type (t1);
639 quals = cp_type_quals (t1);
640 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
641 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
642 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
644 t1 = cp_build_qualified_type (t1, quals);
650 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
651 /* Save space: see if the result is identical to one of the args. */
652 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
653 return build_type_attribute_variant (t1, attributes);
654 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
655 return build_type_attribute_variant (t2, attributes);
656 /* Merge the element types, and have a size if either arg has one. */
657 t1 = build_cplus_array_type
658 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
663 /* Function types: prefer the one that specified arg types.
664 If both do, merge the arg types. Also merge the return types. */
666 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
667 tree p1 = TYPE_ARG_TYPES (t1);
668 tree p2 = TYPE_ARG_TYPES (t2);
671 /* Save space: see if the result is identical to one of the args. */
672 if (valtype == TREE_TYPE (t1) && ! p2)
673 return cp_build_type_attribute_variant (t1, attributes);
674 if (valtype == TREE_TYPE (t2) && ! p1)
675 return cp_build_type_attribute_variant (t2, attributes);
677 /* Simple way if one arg fails to specify argument types. */
678 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
680 rval = build_function_type (valtype, p2);
681 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
682 rval = build_exception_variant (rval, raises);
683 return cp_build_type_attribute_variant (rval, attributes);
685 raises = TYPE_RAISES_EXCEPTIONS (t1);
686 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
688 rval = build_function_type (valtype, p1);
690 rval = build_exception_variant (rval, raises);
691 return cp_build_type_attribute_variant (rval, attributes);
694 rval = build_function_type (valtype, commonparms (p1, p2));
695 t1 = build_exception_variant (rval, raises);
701 /* Get this value the long way, since TYPE_METHOD_BASETYPE
702 is just the main variant of this. */
703 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
704 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
707 /* If this was a member function type, get back to the
708 original type of type member function (i.e., without
709 the class instance variable up front. */
710 t1 = build_function_type (TREE_TYPE (t1),
711 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
712 t2 = build_function_type (TREE_TYPE (t2),
713 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
714 t3 = merge_types (t1, t2);
715 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
716 TYPE_ARG_TYPES (t3));
717 t1 = build_exception_variant (t3, raises);
722 /* There is no need to merge attributes into a TYPENAME_TYPE.
723 When the type is instantiated it will have whatever
724 attributes result from the instantiation. */
730 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
732 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
735 return cp_build_type_attribute_variant (t1, attributes);
738 /* Return the common type of two types.
739 We assume that comptypes has already been done and returned 1;
740 if that isn't so, this may crash.
742 This is the type for the result of most arithmetic operations
743 if the operands have the given two types. */
746 common_type (tree t1, tree t2)
748 enum tree_code code1;
749 enum tree_code code2;
751 /* If one type is nonsense, bail. */
752 if (t1 == error_mark_node || t2 == error_mark_node)
753 return error_mark_node;
755 code1 = TREE_CODE (t1);
756 code2 = TREE_CODE (t2);
758 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
759 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
760 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
761 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
762 return type_after_usual_arithmetic_conversions (t1, t2);
764 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
765 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
766 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
767 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
773 /* Compare two exception specifier types for exactness or subsetness, if
774 allowed. Returns false for mismatch, true for match (same, or
777 [except.spec] "If a class X ... objects of class X or any class publicly
778 and unambiguously derived from X. Similarly, if a pointer type Y * ...
779 exceptions of type Y * or that are pointers to any type publicly and
780 unambiguously derived from Y. Otherwise a function only allows exceptions
781 that have the same type ..."
782 This does not mention cv qualifiers and is different to what throw
783 [except.throw] and catch [except.catch] will do. They will ignore the
784 top level cv qualifiers, and allow qualifiers in the pointer to class
787 We implement the letter of the standard. */
790 comp_except_types (tree a, tree b, bool exact)
792 if (same_type_p (a, b))
796 if (cp_type_quals (a) || cp_type_quals (b))
799 if (TREE_CODE (a) == POINTER_TYPE
800 && TREE_CODE (b) == POINTER_TYPE)
804 if (cp_type_quals (a) || cp_type_quals (b))
808 if (TREE_CODE (a) != RECORD_TYPE
809 || TREE_CODE (b) != RECORD_TYPE)
812 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
818 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
819 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
820 otherwise it must be exact. Exception lists are unordered, but
821 we've already filtered out duplicates. Most lists will be in order,
822 we should try to make use of that. */
825 comp_except_specs (tree t1, tree t2, bool exact)
834 if (t1 == NULL_TREE) /* T1 is ... */
835 return t2 == NULL_TREE || !exact;
836 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
837 return t2 != NULL_TREE && !TREE_VALUE (t2);
838 if (t2 == NULL_TREE) /* T2 is ... */
840 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
843 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
844 Count how many we find, to determine exactness. For exact matching and
845 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
847 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
849 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
851 tree a = TREE_VALUE (probe);
852 tree b = TREE_VALUE (t2);
854 if (comp_except_types (a, b, exact))
856 if (probe == base && exact)
857 base = TREE_CHAIN (probe);
862 if (probe == NULL_TREE)
865 return !exact || base == NULL_TREE || length == list_length (t1);
868 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
869 [] can match [size]. */
872 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
881 /* The type of the array elements must be the same. */
882 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
885 d1 = TYPE_DOMAIN (t1);
886 d2 = TYPE_DOMAIN (t2);
891 /* If one of the arrays is dimensionless, and the other has a
892 dimension, they are of different types. However, it is valid to
900 declarations for an array object can specify
901 array types that differ by the presence or absence of a major
902 array bound (_dcl.array_). */
904 return allow_redeclaration;
906 /* Check that the dimensions are the same. */
908 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
910 max1 = TYPE_MAX_VALUE (d1);
911 max2 = TYPE_MAX_VALUE (d2);
912 if (processing_template_decl && !abi_version_at_least (2)
913 && !value_dependent_expression_p (max1)
914 && !value_dependent_expression_p (max2))
916 /* With abi-1 we do not fold non-dependent array bounds, (and
917 consequently mangle them incorrectly). We must therefore
918 fold them here, to verify the domains have the same
924 if (!cp_tree_equal (max1, max2))
930 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
931 is a bitwise-or of the COMPARE_* flags. */
934 comptypes (tree t1, tree t2, int strict)
939 /* Suppress errors caused by previously reported errors. */
940 if (t1 == error_mark_node || t2 == error_mark_node)
943 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
945 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
946 current instantiation. */
947 if (TREE_CODE (t1) == TYPENAME_TYPE)
949 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
951 if (resolved != error_mark_node)
955 if (TREE_CODE (t2) == TYPENAME_TYPE)
957 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
959 if (resolved != error_mark_node)
963 if (TYPE_PTRMEMFUNC_P (t1))
964 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
965 if (TYPE_PTRMEMFUNC_P (t2))
966 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
968 /* Different classes of types can't be compatible. */
969 if (TREE_CODE (t1) != TREE_CODE (t2))
972 /* Qualifiers must match. For array types, we will check when we
973 recur on the array element types. */
974 if (TREE_CODE (t1) != ARRAY_TYPE
975 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
977 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
980 /* Allow for two different type nodes which have essentially the same
981 definition. Note that we already checked for equality of the type
982 qualifiers (just above). */
984 if (TREE_CODE (t1) != ARRAY_TYPE
985 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
988 /* Compare the types. Break out if they could be the same. */
989 switch (TREE_CODE (t1))
991 case TEMPLATE_TEMPLATE_PARM:
992 case BOUND_TEMPLATE_TEMPLATE_PARM:
993 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
994 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1025 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1030 case REFERENCE_TYPE:
1031 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1032 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1033 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1041 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1046 /* Target types must match incl. qualifiers. */
1047 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1051 case TEMPLATE_TYPE_PARM:
1052 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1053 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1058 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1059 TYPENAME_TYPE_FULLNAME (t2)))
1061 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1065 case UNBOUND_CLASS_TEMPLATE:
1066 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1068 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1073 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1078 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1079 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1087 /* If we get here, we know that from a target independent POV the
1088 types are the same. Make sure the target attributes are also
1090 return targetm.comp_type_attributes (t1, t2);
1093 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1096 at_least_as_qualified_p (tree type1, tree type2)
1098 int q1 = cp_type_quals (type1);
1099 int q2 = cp_type_quals (type2);
1101 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1102 return (q1 & q2) == q2;
1105 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1106 more cv-qualified that TYPE1, and 0 otherwise. */
1109 comp_cv_qualification (tree type1, tree type2)
1111 int q1 = cp_type_quals (type1);
1112 int q2 = cp_type_quals (type2);
1117 if ((q1 & q2) == q2)
1119 else if ((q1 & q2) == q1)
1125 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1126 subset of the cv-qualification signature of TYPE2, and the types
1127 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1130 comp_cv_qual_signature (tree type1, tree type2)
1132 if (comp_ptr_ttypes_real (type2, type1, -1))
1134 else if (comp_ptr_ttypes_real (type1, type2, -1))
1140 /* If two types share a common base type, return that basetype.
1141 If there is not a unique most-derived base type, this function
1142 returns ERROR_MARK_NODE. */
1145 common_base_type (tree tt1, tree tt2)
1147 tree best = NULL_TREE;
1150 /* If one is a baseclass of another, that's good enough. */
1151 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1153 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1156 /* Otherwise, try to find a unique baseclass of TT1
1157 that is shared by TT2, and follow that down. */
1158 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1160 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1161 tree trial = common_base_type (basetype, tt2);
1165 if (trial == error_mark_node)
1167 if (best == NULL_TREE)
1169 else if (best != trial)
1170 return error_mark_node;
1175 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1177 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1178 tree trial = common_base_type (tt1, basetype);
1182 if (trial == error_mark_node)
1184 if (best == NULL_TREE)
1186 else if (best != trial)
1187 return error_mark_node;
1193 /* Subroutines of `comptypes'. */
1195 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1196 equivalent in the sense that functions with those parameter types
1197 can have equivalent types. The two lists must be equivalent,
1198 element by element. */
1201 compparms (tree parms1, tree parms2)
1205 /* An unspecified parmlist matches any specified parmlist
1206 whose argument types don't need default promotions. */
1208 for (t1 = parms1, t2 = parms2;
1210 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1212 /* If one parmlist is shorter than the other,
1213 they fail to match. */
1216 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1223 /* Process a sizeof or alignof expression where the operand is a
1227 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1232 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1233 if (type == error_mark_node)
1234 return error_mark_node;
1236 type = non_reference (type);
1237 if (TREE_CODE (type) == METHOD_TYPE)
1239 if (complain && (pedantic || warn_pointer_arith))
1240 pedwarn ("invalid application of %qs to a member function",
1241 operator_name_info[(int) op].name);
1242 value = size_one_node;
1245 dependent_p = dependent_type_p (type);
1247 complete_type (type);
1249 /* VLA types will have a non-constant size. In the body of an
1250 uninstantiated template, we don't need to try to compute the
1251 value, because the sizeof expression is not an integral
1252 constant expression in that case. And, if we do try to
1253 compute the value, we'll likely end up with SAVE_EXPRs, which
1254 the template substitution machinery does not expect to see. */
1255 || (processing_template_decl
1256 && COMPLETE_TYPE_P (type)
1257 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1259 value = build_min (op, size_type_node, type);
1260 TREE_READONLY (value) = 1;
1264 return c_sizeof_or_alignof_type (complete_type (type),
1269 /* Process a sizeof expression where the operand is an expression. */
1272 cxx_sizeof_expr (tree e)
1274 if (e == error_mark_node)
1275 return error_mark_node;
1277 if (processing_template_decl)
1279 e = build_min (SIZEOF_EXPR, size_type_node, e);
1280 TREE_SIDE_EFFECTS (e) = 0;
1281 TREE_READONLY (e) = 1;
1286 if (TREE_CODE (e) == COMPONENT_REF
1287 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1288 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1290 error ("invalid application of %<sizeof%> to a bit-field");
1293 else if (is_overloaded_fn (e))
1295 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1299 else if (type_unknown_p (e))
1301 cxx_incomplete_type_error (e, TREE_TYPE (e));
1307 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1310 /* Implement the __alignof keyword: Return the minimum required
1311 alignment of E, measured in bytes. For VAR_DECL's and
1312 FIELD_DECL's return DECL_ALIGN (which can be set from an
1313 "aligned" __attribute__ specification). */
1316 cxx_alignof_expr (tree e)
1320 if (e == error_mark_node)
1321 return error_mark_node;
1323 if (processing_template_decl)
1325 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1326 TREE_SIDE_EFFECTS (e) = 0;
1327 TREE_READONLY (e) = 1;
1332 if (TREE_CODE (e) == VAR_DECL)
1333 t = size_int (DECL_ALIGN_UNIT (e));
1334 else if (TREE_CODE (e) == COMPONENT_REF
1335 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1336 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1338 error ("invalid application of %<__alignof%> to a bit-field");
1341 else if (TREE_CODE (e) == COMPONENT_REF
1342 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1343 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1344 else if (is_overloaded_fn (e))
1346 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1350 else if (type_unknown_p (e))
1352 cxx_incomplete_type_error (e, TREE_TYPE (e));
1356 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1358 return fold_convert (size_type_node, t);
1361 /* Process a sizeof or alignof expression E with code OP where the operand
1362 is an expression. */
1365 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1367 if (op == SIZEOF_EXPR)
1368 return cxx_sizeof_expr (e);
1370 return cxx_alignof_expr (e);
1373 /* EXPR is being used in a context that is not a function call.
1378 The expression can be used only as the left-hand operand of a
1379 member function call.
1381 [expr.mptr.operator]
1383 If the result of .* or ->* is a function, then that result can be
1384 used only as the operand for the function call operator ().
1386 by issuing an error message if appropriate. Returns true iff EXPR
1387 violates these rules. */
1390 invalid_nonstatic_memfn_p (tree expr)
1392 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1394 error ("invalid use of non-static member function");
1400 /* If EXP is a reference to a bitfield, and the type of EXP does not
1401 match the declared type of the bitfield, return the declared type
1402 of the bitfield. Otherwise, return NULL_TREE. */
1405 is_bitfield_expr_with_lowered_type (tree exp)
1409 if (TREE_CODE (exp) == COND_EXPR)
1411 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1413 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1415 if (TREE_CODE (exp) != COMPONENT_REF)
1417 field = TREE_OPERAND (exp, 1);
1418 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1420 if (same_type_ignoring_top_level_qualifiers_p
1421 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1423 return DECL_BIT_FIELD_TYPE (field);
1426 /* Perform the conversions in [expr] that apply when an lvalue appears
1427 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1428 function-to-pointer conversions. In addition, manifest constants
1429 are replaced by their values, and bitfield references are converted
1430 to their declared types.
1432 Although the returned value is being used as an rvalue, this
1433 function does not wrap the returned expression in a
1434 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1435 that the return value is no longer an lvalue. */
1438 decay_conversion (tree exp)
1441 enum tree_code code;
1443 type = TREE_TYPE (exp);
1444 if (type == error_mark_node)
1445 return error_mark_node;
1447 if (type_unknown_p (exp))
1449 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1450 return error_mark_node;
1453 exp = decl_constant_value (exp);
1454 if (error_operand_p (exp))
1455 return error_mark_node;
1457 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1458 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1459 code = TREE_CODE (type);
1460 if (code == VOID_TYPE)
1462 error ("void value not ignored as it ought to be");
1463 return error_mark_node;
1465 if (invalid_nonstatic_memfn_p (exp))
1466 return error_mark_node;
1467 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1468 return build_unary_op (ADDR_EXPR, exp, 0);
1469 if (code == ARRAY_TYPE)
1474 if (TREE_CODE (exp) == INDIRECT_REF)
1475 return build_nop (build_pointer_type (TREE_TYPE (type)),
1476 TREE_OPERAND (exp, 0));
1478 if (TREE_CODE (exp) == COMPOUND_EXPR)
1480 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1481 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1482 TREE_OPERAND (exp, 0), op1);
1486 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1488 error ("invalid use of non-lvalue array");
1489 return error_mark_node;
1492 ptrtype = build_pointer_type (TREE_TYPE (type));
1494 if (TREE_CODE (exp) == VAR_DECL)
1496 if (!cxx_mark_addressable (exp))
1497 return error_mark_node;
1498 adr = build_nop (ptrtype, build_address (exp));
1501 /* This way is better for a COMPONENT_REF since it can
1502 simplify the offset for a component. */
1503 adr = build_unary_op (ADDR_EXPR, exp, 1);
1504 return cp_convert (ptrtype, adr);
1507 /* If a bitfield is used in a context where integral promotion
1508 applies, then the caller is expected to have used
1509 default_conversion. That function promotes bitfields correctly
1510 before calling this function. At this point, if we have a
1511 bitfield referenced, we may assume that is not subject to
1512 promotion, and that, therefore, the type of the resulting rvalue
1513 is the declared type of the bitfield. */
1514 exp = convert_bitfield_to_declared_type (exp);
1516 /* We do not call rvalue() here because we do not want to wrap EXP
1517 in a NON_LVALUE_EXPR. */
1521 Non-class rvalues always have cv-unqualified types. */
1522 type = TREE_TYPE (exp);
1523 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1524 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1529 /* Perform prepatory conversions, as part of the "usual arithmetic
1530 conversions". In particular, as per [expr]:
1532 Whenever an lvalue expression appears as an operand of an
1533 operator that expects the rvalue for that operand, the
1534 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1535 standard conversions are applied to convert the expression to an
1538 In addition, we perform integral promotions here, as those are
1539 applied to both operands to a binary operator before determining
1540 what additional conversions should apply. */
1543 default_conversion (tree exp)
1545 /* Perform the integral promotions first so that bitfield
1546 expressions (which may promote to "int", even if the bitfield is
1547 declared "unsigned") are promoted correctly. */
1548 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1549 exp = perform_integral_promotions (exp);
1550 /* Perform the other conversions. */
1551 exp = decay_conversion (exp);
1556 /* EXPR is an expression with an integral or enumeration type.
1557 Perform the integral promotions in [conv.prom], and return the
1561 perform_integral_promotions (tree expr)
1568 If the bitfield has an enumerated type, it is treated as any
1569 other value of that type for promotion purposes. */
1570 type = is_bitfield_expr_with_lowered_type (expr);
1571 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1572 type = TREE_TYPE (expr);
1573 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1574 promoted_type = type_promotes_to (type);
1575 if (type != promoted_type)
1576 expr = cp_convert (promoted_type, expr);
1580 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1584 inline_conversion (tree exp)
1586 if (TREE_CODE (exp) == FUNCTION_DECL)
1587 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1592 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1593 decay_conversion to one. */
1596 string_conv_p (tree totype, tree exp, int warn)
1600 if (TREE_CODE (totype) != POINTER_TYPE)
1603 t = TREE_TYPE (totype);
1604 if (!same_type_p (t, char_type_node)
1605 && !same_type_p (t, wchar_type_node))
1608 if (TREE_CODE (exp) == STRING_CST)
1610 /* Make sure that we don't try to convert between char and wchar_t. */
1611 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1616 /* Is this a string constant which has decayed to 'const char *'? */
1617 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1618 if (!same_type_p (TREE_TYPE (exp), t))
1621 if (TREE_CODE (exp) != ADDR_EXPR
1622 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1626 /* This warning is not very useful, as it complains about printf. */
1628 warning (OPT_Wwrite_strings,
1629 "deprecated conversion from string constant to %qT",
1635 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1636 can, for example, use as an lvalue. This code used to be in
1637 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1638 expressions, where we're dealing with aggregates. But now it's again only
1639 called from unary_complex_lvalue. The case (in particular) that led to
1640 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1644 rationalize_conditional_expr (enum tree_code code, tree t)
1646 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1647 the first operand is always the one to be used if both operands
1648 are equal, so we know what conditional expression this used to be. */
1649 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1651 tree op0 = TREE_OPERAND (t, 0);
1652 tree op1 = TREE_OPERAND (t, 1);
1654 /* The following code is incorrect if either operand side-effects. */
1655 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1656 && !TREE_SIDE_EFFECTS (op1));
1658 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1659 ? LE_EXPR : GE_EXPR),
1660 op0, TREE_CODE (op0),
1661 op1, TREE_CODE (op1),
1662 /*overloaded_p=*/NULL),
1663 build_unary_op (code, op0, 0),
1664 build_unary_op (code, op1, 0));
1668 build_conditional_expr (TREE_OPERAND (t, 0),
1669 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1670 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1673 /* Given the TYPE of an anonymous union field inside T, return the
1674 FIELD_DECL for the field. If not found return NULL_TREE. Because
1675 anonymous unions can nest, we must also search all anonymous unions
1676 that are directly reachable. */
1679 lookup_anon_field (tree t, tree type)
1683 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1685 if (TREE_STATIC (field))
1687 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1690 /* If we find it directly, return the field. */
1691 if (DECL_NAME (field) == NULL_TREE
1692 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1697 /* Otherwise, it could be nested, search harder. */
1698 if (DECL_NAME (field) == NULL_TREE
1699 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1701 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1709 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1710 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1711 non-NULL, it indicates the path to the base used to name MEMBER.
1712 If PRESERVE_REFERENCE is true, the expression returned will have
1713 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1714 returned will have the type referred to by the reference.
1716 This function does not perform access control; that is either done
1717 earlier by the parser when the name of MEMBER is resolved to MEMBER
1718 itself, or later when overload resolution selects one of the
1719 functions indicated by MEMBER. */
1722 build_class_member_access_expr (tree object, tree member,
1723 tree access_path, bool preserve_reference)
1727 tree result = NULL_TREE;
1729 if (error_operand_p (object) || error_operand_p (member))
1730 return error_mark_node;
1732 gcc_assert (DECL_P (member) || BASELINK_P (member));
1736 The type of the first expression shall be "class object" (of a
1738 object_type = TREE_TYPE (object);
1739 if (!currently_open_class (object_type)
1740 && !complete_type_or_else (object_type, object))
1741 return error_mark_node;
1742 if (!CLASS_TYPE_P (object_type))
1744 error ("request for member %qD in %qE, which is of non-class type %qT",
1745 member, object, object_type);
1746 return error_mark_node;
1749 /* The standard does not seem to actually say that MEMBER must be a
1750 member of OBJECT_TYPE. However, that is clearly what is
1752 if (DECL_P (member))
1754 member_scope = DECL_CLASS_CONTEXT (member);
1756 if (TREE_DEPRECATED (member))
1757 warn_deprecated_use (member);
1760 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1761 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1762 presently be the anonymous union. Go outwards until we find a
1763 type related to OBJECT_TYPE. */
1764 while (ANON_AGGR_TYPE_P (member_scope)
1765 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1767 member_scope = TYPE_CONTEXT (member_scope);
1768 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1770 if (TREE_CODE (member) == FIELD_DECL)
1771 error ("invalid use of nonstatic data member %qE", member);
1773 error ("%qD is not a member of %qT", member, object_type);
1774 return error_mark_node;
1777 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1778 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1779 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1781 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1783 object = build_indirect_ref (temp, NULL);
1786 /* In [expr.ref], there is an explicit list of the valid choices for
1787 MEMBER. We check for each of those cases here. */
1788 if (TREE_CODE (member) == VAR_DECL)
1790 /* A static data member. */
1792 /* If OBJECT has side-effects, they are supposed to occur. */
1793 if (TREE_SIDE_EFFECTS (object))
1794 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1796 else if (TREE_CODE (member) == FIELD_DECL)
1798 /* A non-static data member. */
1803 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1804 && integer_zerop (TREE_OPERAND (object, 0)));
1806 /* Convert OBJECT to the type of MEMBER. */
1807 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1808 TYPE_MAIN_VARIANT (member_scope)))
1813 binfo = lookup_base (access_path ? access_path : object_type,
1814 member_scope, ba_unique, &kind);
1815 if (binfo == error_mark_node)
1816 return error_mark_node;
1818 /* It is invalid to try to get to a virtual base of a
1819 NULL object. The most common cause is invalid use of
1821 if (null_object_p && kind == bk_via_virtual)
1823 error ("invalid access to non-static data member %qD of "
1826 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1827 return error_mark_node;
1830 /* Convert to the base. */
1831 object = build_base_path (PLUS_EXPR, object, binfo,
1833 /* If we found the base successfully then we should be able
1834 to convert to it successfully. */
1835 gcc_assert (object != error_mark_node);
1838 /* Complain about other invalid uses of offsetof, even though they will
1839 give the right answer. Note that we complain whether or not they
1840 actually used the offsetof macro, since there's no way to know at this
1841 point. So we just give a warning, instead of a pedwarn. */
1842 /* Do not produce this warning for base class field references, because
1843 we know for a fact that didn't come from offsetof. This does occur
1844 in various testsuite cases where a null object is passed where a
1845 vtable access is required. */
1846 if (null_object_p && warn_invalid_offsetof
1847 && CLASSTYPE_NON_POD_P (object_type)
1848 && !DECL_FIELD_IS_BASE (member)
1849 && !skip_evaluation)
1851 warning (0, "invalid access to non-static data member %qD of NULL object",
1853 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1856 /* If MEMBER is from an anonymous aggregate, we have converted
1857 OBJECT so that it refers to the class containing the
1858 anonymous union. Generate a reference to the anonymous union
1859 itself, and recur to find MEMBER. */
1860 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1861 /* When this code is called from build_field_call, the
1862 object already has the type of the anonymous union.
1863 That is because the COMPONENT_REF was already
1864 constructed, and was then disassembled before calling
1865 build_field_call. After the function-call code is
1866 cleaned up, this waste can be eliminated. */
1867 && (!same_type_ignoring_top_level_qualifiers_p
1868 (TREE_TYPE (object), DECL_CONTEXT (member))))
1870 tree anonymous_union;
1872 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1873 DECL_CONTEXT (member));
1874 object = build_class_member_access_expr (object,
1876 /*access_path=*/NULL_TREE,
1877 preserve_reference);
1880 /* Compute the type of the field, as described in [expr.ref]. */
1881 type_quals = TYPE_UNQUALIFIED;
1882 member_type = TREE_TYPE (member);
1883 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1885 type_quals = (cp_type_quals (member_type)
1886 | cp_type_quals (object_type));
1888 /* A field is const (volatile) if the enclosing object, or the
1889 field itself, is const (volatile). But, a mutable field is
1890 not const, even within a const object. */
1891 if (DECL_MUTABLE_P (member))
1892 type_quals &= ~TYPE_QUAL_CONST;
1893 member_type = cp_build_qualified_type (member_type, type_quals);
1896 result = build3 (COMPONENT_REF, member_type, object, member,
1898 result = fold_if_not_in_template (result);
1900 /* Mark the expression const or volatile, as appropriate. Even
1901 though we've dealt with the type above, we still have to mark the
1902 expression itself. */
1903 if (type_quals & TYPE_QUAL_CONST)
1904 TREE_READONLY (result) = 1;
1905 if (type_quals & TYPE_QUAL_VOLATILE)
1906 TREE_THIS_VOLATILE (result) = 1;
1908 else if (BASELINK_P (member))
1910 /* The member is a (possibly overloaded) member function. */
1914 /* If the MEMBER is exactly one static member function, then we
1915 know the type of the expression. Otherwise, we must wait
1916 until overload resolution has been performed. */
1917 functions = BASELINK_FUNCTIONS (member);
1918 if (TREE_CODE (functions) == FUNCTION_DECL
1919 && DECL_STATIC_FUNCTION_P (functions))
1920 type = TREE_TYPE (functions);
1922 type = unknown_type_node;
1923 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1924 base. That will happen when the function is called. */
1925 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1927 else if (TREE_CODE (member) == CONST_DECL)
1929 /* The member is an enumerator. */
1931 /* If OBJECT has side-effects, they are supposed to occur. */
1932 if (TREE_SIDE_EFFECTS (object))
1933 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1938 error ("invalid use of %qD", member);
1939 return error_mark_node;
1942 if (!preserve_reference)
1945 If E2 is declared to have type "reference to T", then ... the
1946 type of E1.E2 is T. */
1947 result = convert_from_reference (result);
1952 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1953 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1956 lookup_destructor (tree object, tree scope, tree dtor_name)
1958 tree object_type = TREE_TYPE (object);
1959 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1962 if (scope && !check_dtor_name (scope, dtor_type))
1964 error ("qualified type %qT does not match destructor name ~%qT",
1966 return error_mark_node;
1968 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1970 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1971 TYPE_MAIN_VARIANT (object_type), dtor_type);
1972 return error_mark_node;
1974 expr = lookup_member (dtor_type, complete_dtor_identifier,
1975 /*protect=*/1, /*want_type=*/false);
1976 expr = (adjust_result_of_qualified_name_lookup
1977 (expr, dtor_type, object_type));
1981 /* An expression of the form "A::template B" has been resolved to
1982 DECL. Issue a diagnostic if B is not a template or template
1986 check_template_keyword (tree decl)
1988 /* The standard says:
1992 If a name prefixed by the keyword template is not a member
1993 template, the program is ill-formed.
1995 DR 228 removed the restriction that the template be a member
1998 DR 96, if accepted would add the further restriction that explicit
1999 template arguments must be provided if the template keyword is
2000 used, but, as of 2005-10-16, that DR is still in "drafting". If
2001 this DR is accepted, then the semantic checks here can be
2002 simplified, as the entity named must in fact be a template
2003 specialization, rather than, as at present, a set of overloaded
2004 functions containing at least one template function. */
2005 if (TREE_CODE (decl) != TEMPLATE_DECL
2006 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2008 if (!is_overloaded_fn (decl))
2009 pedwarn ("%qD is not a template", decl);
2014 if (BASELINK_P (fns))
2015 fns = BASELINK_FUNCTIONS (fns);
2018 tree fn = OVL_CURRENT (fns);
2019 if (TREE_CODE (fn) == TEMPLATE_DECL
2020 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2022 if (TREE_CODE (fn) == FUNCTION_DECL
2023 && DECL_USE_TEMPLATE (fn)
2024 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2026 fns = OVL_NEXT (fns);
2029 pedwarn ("%qD is not a template", decl);
2034 /* This function is called by the parser to process a class member
2035 access expression of the form OBJECT.NAME. NAME is a node used by
2036 the parser to represent a name; it is not yet a DECL. It may,
2037 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2038 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2039 there is no reason to do the lookup twice, so the parser keeps the
2040 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2041 be a template via the use of the "A::template B" syntax. */
2044 finish_class_member_access_expr (tree object, tree name, bool template_p)
2049 tree access_path = NULL_TREE;
2050 tree orig_object = object;
2051 tree orig_name = name;
2053 if (object == error_mark_node || name == error_mark_node)
2054 return error_mark_node;
2056 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2057 if (!objc_is_public (object, name))
2058 return error_mark_node;
2060 object_type = TREE_TYPE (object);
2062 if (processing_template_decl)
2064 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2065 dependent_type_p (object_type)
2066 /* If NAME is just an IDENTIFIER_NODE, then the expression
2068 || TREE_CODE (object) == IDENTIFIER_NODE
2069 /* If NAME is "f<args>", where either 'f' or 'args' is
2070 dependent, then the expression is dependent. */
2071 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2072 && dependent_template_id_p (TREE_OPERAND (name, 0),
2073 TREE_OPERAND (name, 1)))
2074 /* If NAME is "T::X" where "T" is dependent, then the
2075 expression is dependent. */
2076 || (TREE_CODE (name) == SCOPE_REF
2077 && TYPE_P (TREE_OPERAND (name, 0))
2078 && dependent_type_p (TREE_OPERAND (name, 0))))
2079 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2080 object = build_non_dependent_expr (object);
2085 The type of the first expression shall be "class object" (of a
2087 if (!currently_open_class (object_type)
2088 && !complete_type_or_else (object_type, object))
2089 return error_mark_node;
2090 if (!CLASS_TYPE_P (object_type))
2092 error ("request for member %qD in %qE, which is of non-class type %qT",
2093 name, object, object_type);
2094 return error_mark_node;
2097 if (BASELINK_P (name))
2098 /* A member function that has already been looked up. */
2102 bool is_template_id = false;
2103 tree template_args = NULL_TREE;
2106 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2108 is_template_id = true;
2109 template_args = TREE_OPERAND (name, 1);
2110 name = TREE_OPERAND (name, 0);
2112 if (TREE_CODE (name) == OVERLOAD)
2113 name = DECL_NAME (get_first_fn (name));
2114 else if (DECL_P (name))
2115 name = DECL_NAME (name);
2118 if (TREE_CODE (name) == SCOPE_REF)
2120 /* A qualified name. The qualifying class or namespace `S'
2121 has already been looked up; it is either a TYPE or a
2123 scope = TREE_OPERAND (name, 0);
2124 name = TREE_OPERAND (name, 1);
2126 /* If SCOPE is a namespace, then the qualified name does not
2127 name a member of OBJECT_TYPE. */
2128 if (TREE_CODE (scope) == NAMESPACE_DECL)
2130 error ("%<%D::%D%> is not a member of %qT",
2131 scope, name, object_type);
2132 return error_mark_node;
2135 gcc_assert (CLASS_TYPE_P (scope));
2136 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2137 || TREE_CODE (name) == BIT_NOT_EXPR);
2139 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2140 access_path = lookup_base (object_type, scope, ba_check, NULL);
2141 if (access_path == error_mark_node)
2142 return error_mark_node;
2145 error ("%qT is not a base of %qT", scope, object_type);
2146 return error_mark_node;
2152 access_path = object_type;
2155 if (TREE_CODE (name) == BIT_NOT_EXPR)
2156 member = lookup_destructor (object, scope, name);
2159 /* Look up the member. */
2160 member = lookup_member (access_path, name, /*protect=*/1,
2161 /*want_type=*/false);
2162 if (member == NULL_TREE)
2164 error ("%qD has no member named %qE", object_type, name);
2165 return error_mark_node;
2167 if (member == error_mark_node)
2168 return error_mark_node;
2173 tree template = member;
2175 if (BASELINK_P (template))
2176 template = lookup_template_function (template, template_args);
2179 error ("%qD is not a member template function", name);
2180 return error_mark_node;
2185 if (TREE_DEPRECATED (member))
2186 warn_deprecated_use (member);
2189 check_template_keyword (member);
2191 expr = build_class_member_access_expr (object, member, access_path,
2192 /*preserve_reference=*/false);
2193 if (processing_template_decl && expr != error_mark_node)
2195 if (BASELINK_P (member))
2197 if (TREE_CODE (orig_name) == SCOPE_REF)
2198 BASELINK_QUALIFIED_P (member) = 1;
2201 return build_min_non_dep (COMPONENT_REF, expr,
2202 orig_object, orig_name,
2209 /* Return an expression for the MEMBER_NAME field in the internal
2210 representation of PTRMEM, a pointer-to-member function. (Each
2211 pointer-to-member function type gets its own RECORD_TYPE so it is
2212 more convenient to access the fields by name than by FIELD_DECL.)
2213 This routine converts the NAME to a FIELD_DECL and then creates the
2214 node for the complete expression. */
2217 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2223 /* This code is a stripped down version of
2224 build_class_member_access_expr. It does not work to use that
2225 routine directly because it expects the object to be of class
2227 ptrmem_type = TREE_TYPE (ptrmem);
2228 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2229 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2230 /*want_type=*/false);
2231 member_type = cp_build_qualified_type (TREE_TYPE (member),
2232 cp_type_quals (ptrmem_type));
2233 return fold_build3 (COMPONENT_REF, member_type,
2234 ptrmem, member, NULL_TREE);
2237 /* Given an expression PTR for a pointer, return an expression
2238 for the value pointed to.
2239 ERRORSTRING is the name of the operator to appear in error messages.
2241 This function may need to overload OPERATOR_FNNAME.
2242 Must also handle REFERENCE_TYPEs for C++. */
2245 build_x_indirect_ref (tree expr, const char *errorstring)
2247 tree orig_expr = expr;
2250 if (processing_template_decl)
2252 if (type_dependent_expression_p (expr))
2253 return build_min_nt (INDIRECT_REF, expr);
2254 expr = build_non_dependent_expr (expr);
2257 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2258 NULL_TREE, /*overloaded_p=*/NULL);
2260 rval = build_indirect_ref (expr, errorstring);
2262 if (processing_template_decl && rval != error_mark_node)
2263 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2269 build_indirect_ref (tree ptr, const char *errorstring)
2273 if (ptr == error_mark_node)
2274 return error_mark_node;
2276 if (ptr == current_class_ptr)
2277 return current_class_ref;
2279 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2280 ? ptr : decay_conversion (ptr));
2281 type = TREE_TYPE (pointer);
2283 if (POINTER_TYPE_P (type))
2287 If the type of the expression is "pointer to T," the type
2288 of the result is "T."
2290 We must use the canonical variant because certain parts of
2291 the back end, like fold, do pointer comparisons between
2293 tree t = canonical_type_variant (TREE_TYPE (type));
2295 if (VOID_TYPE_P (t))
2297 /* A pointer to incomplete type (other than cv void) can be
2298 dereferenced [expr.unary.op]/1 */
2299 error ("%qT is not a pointer-to-object type", type);
2300 return error_mark_node;
2302 else if (TREE_CODE (pointer) == ADDR_EXPR
2303 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2304 /* The POINTER was something like `&x'. We simplify `*&x' to
2306 return TREE_OPERAND (pointer, 0);
2309 tree ref = build1 (INDIRECT_REF, t, pointer);
2311 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2312 so that we get the proper error message if the result is used
2313 to assign to. Also, &* is supposed to be a no-op. */
2314 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2315 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2316 TREE_SIDE_EFFECTS (ref)
2317 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2321 /* `pointer' won't be an error_mark_node if we were given a
2322 pointer to member, so it's cool to check for this here. */
2323 else if (TYPE_PTR_TO_MEMBER_P (type))
2324 error ("invalid use of %qs on pointer to member", errorstring);
2325 else if (pointer != error_mark_node)
2328 error ("invalid type argument of %qs", errorstring);
2330 error ("invalid type argument");
2332 return error_mark_node;
2335 /* This handles expressions of the form "a[i]", which denotes
2338 This is logically equivalent in C to *(a+i), but we may do it differently.
2339 If A is a variable or a member, we generate a primitive ARRAY_REF.
2340 This avoids forcing the array out of registers, and can work on
2341 arrays that are not lvalues (for example, members of structures returned
2344 If INDEX is of some user-defined type, it must be converted to
2345 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2346 will inherit the type of the array, which will be some pointer type. */
2349 build_array_ref (tree array, tree idx)
2353 error ("subscript missing in array reference");
2354 return error_mark_node;
2357 if (TREE_TYPE (array) == error_mark_node
2358 || TREE_TYPE (idx) == error_mark_node)
2359 return error_mark_node;
2361 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2363 switch (TREE_CODE (array))
2367 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2368 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2369 TREE_OPERAND (array, 0), value);
2373 return build_conditional_expr
2374 (TREE_OPERAND (array, 0),
2375 build_array_ref (TREE_OPERAND (array, 1), idx),
2376 build_array_ref (TREE_OPERAND (array, 2), idx));
2382 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2386 warn_array_subscript_with_type_char (idx);
2388 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2390 error ("array subscript is not an integer");
2391 return error_mark_node;
2394 /* Apply integral promotions *after* noticing character types.
2395 (It is unclear why we do these promotions -- the standard
2396 does not say that we should. In fact, the natural thing would
2397 seem to be to convert IDX to ptrdiff_t; we're performing
2398 pointer arithmetic.) */
2399 idx = perform_integral_promotions (idx);
2401 /* An array that is indexed by a non-constant
2402 cannot be stored in a register; we must be able to do
2403 address arithmetic on its address.
2404 Likewise an array of elements of variable size. */
2405 if (TREE_CODE (idx) != INTEGER_CST
2406 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2407 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2410 if (!cxx_mark_addressable (array))
2411 return error_mark_node;
2414 /* An array that is indexed by a constant value which is not within
2415 the array bounds cannot be stored in a register either; because we
2416 would get a crash in store_bit_field/extract_bit_field when trying
2417 to access a non-existent part of the register. */
2418 if (TREE_CODE (idx) == INTEGER_CST
2419 && TYPE_DOMAIN (TREE_TYPE (array))
2420 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2422 if (!cxx_mark_addressable (array))
2423 return error_mark_node;
2426 if (pedantic && !lvalue_p (array))
2427 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2429 /* Note in C++ it is valid to subscript a `register' array, since
2430 it is valid to take the address of something with that
2431 storage specification. */
2435 while (TREE_CODE (foo) == COMPONENT_REF)
2436 foo = TREE_OPERAND (foo, 0);
2437 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2438 warning (OPT_Wextra, "subscripting array declared %<register%>");
2441 type = TREE_TYPE (TREE_TYPE (array));
2442 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2443 /* Array ref is const/volatile if the array elements are
2444 or if the array is.. */
2445 TREE_READONLY (rval)
2446 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2447 TREE_SIDE_EFFECTS (rval)
2448 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2449 TREE_THIS_VOLATILE (rval)
2450 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2451 return require_complete_type (fold_if_not_in_template (rval));
2455 tree ar = default_conversion (array);
2456 tree ind = default_conversion (idx);
2458 /* Put the integer in IND to simplify error checking. */
2459 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2466 if (ar == error_mark_node)
2469 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2471 error ("subscripted value is neither array nor pointer");
2472 return error_mark_node;
2474 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2476 error ("array subscript is not an integer");
2477 return error_mark_node;
2480 warn_array_subscript_with_type_char (idx);
2482 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2487 /* Resolve a pointer to member function. INSTANCE is the object
2488 instance to use, if the member points to a virtual member.
2490 This used to avoid checking for virtual functions if basetype
2491 has no virtual functions, according to an earlier ANSI draft.
2492 With the final ISO C++ rules, such an optimization is
2493 incorrect: A pointer to a derived member can be static_cast
2494 to pointer-to-base-member, as long as the dynamic object
2495 later has the right member. */
2498 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2500 if (TREE_CODE (function) == OFFSET_REF)
2501 function = TREE_OPERAND (function, 1);
2503 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2505 tree idx, delta, e1, e2, e3, vtbl, basetype;
2506 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2508 tree instance_ptr = *instance_ptrptr;
2509 tree instance_save_expr = 0;
2510 if (instance_ptr == error_mark_node)
2512 if (TREE_CODE (function) == PTRMEM_CST)
2514 /* Extracting the function address from a pmf is only
2515 allowed with -Wno-pmf-conversions. It only works for
2517 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2518 e1 = convert (fntype, e1);
2523 error ("object missing in use of %qE", function);
2524 return error_mark_node;
2528 if (TREE_SIDE_EFFECTS (instance_ptr))
2529 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2531 if (TREE_SIDE_EFFECTS (function))
2532 function = save_expr (function);
2534 /* Start by extracting all the information from the PMF itself. */
2535 e3 = pfn_from_ptrmemfunc (function);
2536 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2537 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2538 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2540 case ptrmemfunc_vbit_in_pfn:
2541 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2542 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2545 case ptrmemfunc_vbit_in_delta:
2546 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2547 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2554 /* Convert down to the right base before using the instance. A
2555 special case is that in a pointer to member of class C, C may
2556 be incomplete. In that case, the function will of course be
2557 a member of C, and no conversion is required. In fact,
2558 lookup_base will fail in that case, because incomplete
2559 classes do not have BINFOs. */
2560 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2561 if (!same_type_ignoring_top_level_qualifiers_p
2562 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2564 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2565 basetype, ba_check, NULL);
2566 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2568 if (instance_ptr == error_mark_node)
2569 return error_mark_node;
2571 /* ...and then the delta in the PMF. */
2572 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2573 instance_ptr, delta);
2575 /* Hand back the adjusted 'this' argument to our caller. */
2576 *instance_ptrptr = instance_ptr;
2578 /* Next extract the vtable pointer from the object. */
2579 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2581 vtbl = build_indirect_ref (vtbl, NULL);
2583 /* Finally, extract the function pointer from the vtable. */
2584 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2585 e2 = build_indirect_ref (e2, NULL);
2586 TREE_CONSTANT (e2) = 1;
2587 TREE_INVARIANT (e2) = 1;
2589 /* When using function descriptors, the address of the
2590 vtable entry is treated as a function pointer. */
2591 if (TARGET_VTABLE_USES_DESCRIPTORS)
2592 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2593 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2595 TREE_TYPE (e2) = TREE_TYPE (e3);
2596 e1 = build_conditional_expr (e1, e2, e3);
2598 /* Make sure this doesn't get evaluated first inside one of the
2599 branches of the COND_EXPR. */
2600 if (instance_save_expr)
2601 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2602 instance_save_expr, e1);
2610 build_function_call (tree function, tree params)
2612 tree fntype, fndecl;
2613 tree coerced_params;
2614 tree name = NULL_TREE;
2616 tree original = function;
2618 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2619 expressions, like those used for ObjC messenger dispatches. */
2620 function = objc_rewrite_function_call (function, params);
2622 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2623 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2624 if (TREE_CODE (function) == NOP_EXPR
2625 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2626 function = TREE_OPERAND (function, 0);
2628 if (TREE_CODE (function) == FUNCTION_DECL)
2630 name = DECL_NAME (function);
2632 mark_used (function);
2635 /* Convert anything with function type to a pointer-to-function. */
2636 if (pedantic && DECL_MAIN_P (function))
2637 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2639 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2640 (because calling an inline function does not mean the function
2641 needs to be separately compiled). */
2643 if (DECL_INLINE (function))
2644 function = inline_conversion (function);
2646 function = build_addr_func (function);
2652 function = build_addr_func (function);
2655 if (function == error_mark_node)
2656 return error_mark_node;
2658 fntype = TREE_TYPE (function);
2660 if (TYPE_PTRMEMFUNC_P (fntype))
2662 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2663 "function in %<%E (...)%>",
2665 return error_mark_node;
2668 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2669 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2671 if (!((TREE_CODE (fntype) == POINTER_TYPE
2672 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2674 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2676 error ("%qE cannot be used as a function", original);
2677 return error_mark_node;
2680 /* fntype now gets the type of function pointed to. */
2681 fntype = TREE_TYPE (fntype);
2683 /* Convert the parameters to the types declared in the
2684 function prototype, or apply default promotions. */
2686 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2687 params, fndecl, LOOKUP_NORMAL);
2688 if (coerced_params == error_mark_node)
2689 return error_mark_node;
2691 /* Check for errors in format strings and inappropriately
2694 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2695 TYPE_ARG_TYPES (fntype));
2697 return build_cxx_call (function, coerced_params);
2700 /* Convert the actual parameter expressions in the list VALUES
2701 to the types in the list TYPELIST.
2702 If parmdecls is exhausted, or when an element has NULL as its type,
2703 perform the default conversions.
2705 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2707 This is also where warnings about wrong number of args are generated.
2709 Return a list of expressions for the parameters as converted.
2711 Both VALUES and the returned value are chains of TREE_LIST nodes
2712 with the elements of the list in the TREE_VALUE slots of those nodes.
2714 In C++, unspecified trailing parameters can be filled in with their
2715 default arguments, if such were specified. Do so here. */
2718 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2720 tree typetail, valtail;
2721 tree result = NULL_TREE;
2722 const char *called_thing = 0;
2725 /* Argument passing is always copy-initialization. */
2726 flags |= LOOKUP_ONLYCONVERTING;
2730 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2732 if (DECL_NAME (fndecl) == NULL_TREE
2733 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2734 called_thing = "constructor";
2736 called_thing = "member function";
2739 called_thing = "function";
2742 for (valtail = values, typetail = typelist;
2744 valtail = TREE_CHAIN (valtail), i++)
2746 tree type = typetail ? TREE_VALUE (typetail) : 0;
2747 tree val = TREE_VALUE (valtail);
2749 if (val == error_mark_node || type == error_mark_node)
2750 return error_mark_node;
2752 if (type == void_type_node)
2756 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2757 error ("at this point in file");
2760 error ("too many arguments to function");
2761 /* In case anybody wants to know if this argument
2764 TREE_TYPE (tree_last (result)) = error_mark_node;
2768 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2769 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2770 if (TREE_CODE (val) == NOP_EXPR
2771 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2772 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2773 val = TREE_OPERAND (val, 0);
2775 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2777 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2778 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2779 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2780 val = decay_conversion (val);
2783 if (val == error_mark_node)
2784 return error_mark_node;
2788 /* Formal parm type is specified by a function prototype. */
2791 if (!COMPLETE_TYPE_P (complete_type (type)))
2794 error ("parameter %P of %qD has incomplete type %qT",
2797 error ("parameter %P has incomplete type %qT", i, type);
2798 parmval = error_mark_node;
2802 parmval = convert_for_initialization
2803 (NULL_TREE, type, val, flags,
2804 "argument passing", fndecl, i);
2805 parmval = convert_for_arg_passing (type, parmval);
2808 if (parmval == error_mark_node)
2809 return error_mark_node;
2811 result = tree_cons (NULL_TREE, parmval, result);
2815 if (fndecl && DECL_BUILT_IN (fndecl)
2816 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2817 /* Don't do ellipsis conversion for __built_in_constant_p
2818 as this will result in spurious warnings for non-POD
2820 val = require_complete_type (val);
2822 val = convert_arg_to_ellipsis (val);
2824 result = tree_cons (NULL_TREE, val, result);
2828 typetail = TREE_CHAIN (typetail);
2831 if (typetail != 0 && typetail != void_list_node)
2833 /* See if there are default arguments that can be used. */
2834 if (TREE_PURPOSE (typetail)
2835 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2837 for (; typetail != void_list_node; ++i)
2840 = convert_default_arg (TREE_VALUE (typetail),
2841 TREE_PURPOSE (typetail),
2844 if (parmval == error_mark_node)
2845 return error_mark_node;
2847 result = tree_cons (0, parmval, result);
2848 typetail = TREE_CHAIN (typetail);
2849 /* ends with `...'. */
2850 if (typetail == NULL_TREE)
2858 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2859 error ("at this point in file");
2862 error ("too few arguments to function");
2863 return error_mark_node;
2867 return nreverse (result);
2870 /* Build a binary-operation expression, after performing default
2871 conversions on the operands. CODE is the kind of expression to
2872 build. ARG1 and ARG2 are the arguments. ARG1_CODE and ARG2_CODE
2873 are the tree codes which correspond to ARG1 and ARG2 when issuing
2874 warnings about possibly misplaced parentheses. They may differ
2875 from the TREE_CODE of ARG1 and ARG2 if the parser has done constant
2876 folding (e.g., if the parser sees "a | 1 + 1", it may call this
2877 routine with ARG2 being an INTEGER_CST and ARG2_CODE == PLUS_EXPR).
2878 To avoid issuing any parentheses warnings, pass ARG1_CODE and/or
2879 ARG2_CODE as ERROR_MARK. */
2882 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2883 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2892 if (processing_template_decl)
2894 if (type_dependent_expression_p (arg1)
2895 || type_dependent_expression_p (arg2))
2896 return build_min_nt (code, arg1, arg2);
2897 arg1 = build_non_dependent_expr (arg1);
2898 arg2 = build_non_dependent_expr (arg2);
2901 if (code == DOTSTAR_EXPR)
2902 expr = build_m_component_ref (arg1, arg2);
2904 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2907 /* Check for cases such as x+y<<z which users are likely to
2908 misinterpret. But don't warn about obj << x + y, since that is a
2909 common idiom for I/O. */
2910 if (warn_parentheses
2911 && !processing_template_decl
2912 && !error_operand_p (arg1)
2913 && !error_operand_p (arg2)
2914 && (code != LSHIFT_EXPR
2915 || !CLASS_TYPE_P (TREE_TYPE (arg1))))
2916 warn_about_parentheses (code, arg1_code, arg2_code);
2918 if (processing_template_decl && expr != error_mark_node)
2919 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2924 /* Build a binary-operation expression without default conversions.
2925 CODE is the kind of expression to build.
2926 This function differs from `build' in several ways:
2927 the data type of the result is computed and recorded in it,
2928 warnings are generated if arg data types are invalid,
2929 special handling for addition and subtraction of pointers is known,
2930 and some optimization is done (operations on narrow ints
2931 are done in the narrower type when that gives the same result).
2932 Constant folding is also done before the result is returned.
2934 Note that the operands will never have enumeral types
2935 because either they have just had the default conversions performed
2936 or they have both just been converted to some other type in which
2937 the arithmetic is to be done.
2939 C++: must do special pointer arithmetic when implementing
2940 multiple inheritance, and deal with pointer to member functions. */
2943 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2944 int convert_p ATTRIBUTE_UNUSED)
2947 enum tree_code code0, code1;
2949 const char *invalid_op_diag;
2951 /* Expression code to give to the expression when it is built.
2952 Normally this is CODE, which is what the caller asked for,
2953 but in some special cases we change it. */
2954 enum tree_code resultcode = code;
2956 /* Data type in which the computation is to be performed.
2957 In the simplest cases this is the common type of the arguments. */
2958 tree result_type = NULL;
2960 /* Nonzero means operands have already been type-converted
2961 in whatever way is necessary.
2962 Zero means they need to be converted to RESULT_TYPE. */
2965 /* Nonzero means create the expression with this type, rather than
2967 tree build_type = 0;
2969 /* Nonzero means after finally constructing the expression
2970 convert it to this type. */
2971 tree final_type = 0;
2975 /* Nonzero if this is an operation like MIN or MAX which can
2976 safely be computed in short if both args are promoted shorts.
2977 Also implies COMMON.
2978 -1 indicates a bitwise operation; this makes a difference
2979 in the exact conditions for when it is safe to do the operation
2980 in a narrower mode. */
2983 /* Nonzero if this is a comparison operation;
2984 if both args are promoted shorts, compare the original shorts.
2985 Also implies COMMON. */
2986 int short_compare = 0;
2988 /* Nonzero if this is a right-shift operation, which can be computed on the
2989 original short and then promoted if the operand is a promoted short. */
2990 int short_shift = 0;
2992 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2995 /* True if both operands have arithmetic type. */
2996 bool arithmetic_types_p;
2998 /* Apply default conversions. */
3002 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3003 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3004 || code == TRUTH_XOR_EXPR)
3006 if (!really_overloaded_fn (op0))
3007 op0 = decay_conversion (op0);
3008 if (!really_overloaded_fn (op1))
3009 op1 = decay_conversion (op1);
3013 if (!really_overloaded_fn (op0))
3014 op0 = default_conversion (op0);
3015 if (!really_overloaded_fn (op1))
3016 op1 = default_conversion (op1);
3019 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3020 STRIP_TYPE_NOPS (op0);
3021 STRIP_TYPE_NOPS (op1);
3023 /* DTRT if one side is an overloaded function, but complain about it. */
3024 if (type_unknown_p (op0))
3026 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3027 if (t != error_mark_node)
3029 pedwarn ("assuming cast to type %qT from overloaded function",
3034 if (type_unknown_p (op1))
3036 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3037 if (t != error_mark_node)
3039 pedwarn ("assuming cast to type %qT from overloaded function",
3045 type0 = TREE_TYPE (op0);
3046 type1 = TREE_TYPE (op1);
3048 /* The expression codes of the data types of the arguments tell us
3049 whether the arguments are integers, floating, pointers, etc. */
3050 code0 = TREE_CODE (type0);
3051 code1 = TREE_CODE (type1);
3053 /* If an error was already reported for one of the arguments,
3054 avoid reporting another error. */
3056 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3057 return error_mark_node;
3059 if ((invalid_op_diag
3060 = targetm.invalid_binary_op (code, type0, type1)))
3062 error (invalid_op_diag);
3063 return error_mark_node;
3069 /* Subtraction of two similar pointers.
3070 We must subtract them as integers, then divide by object size. */
3071 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3072 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3074 return pointer_diff (op0, op1, common_type (type0, type1));
3075 /* In all other cases except pointer - int, the usual arithmetic
3077 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3082 /* The pointer - int case is just like pointer + int; fall
3085 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3086 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3090 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3091 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3092 if (processing_template_decl)
3094 result_type = TREE_TYPE (ptr_operand);
3097 return cp_pointer_int_sum (code,
3108 case TRUNC_DIV_EXPR:
3110 case FLOOR_DIV_EXPR:
3111 case ROUND_DIV_EXPR:
3112 case EXACT_DIV_EXPR:
3113 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3114 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3115 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3116 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3118 enum tree_code tcode0 = code0, tcode1 = code1;
3120 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3121 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3122 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3123 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3125 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3126 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3127 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3128 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3130 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3131 resultcode = RDIV_EXPR;
3133 /* When dividing two signed integers, we have to promote to int.
3134 unless we divide by a constant != -1. Note that default
3135 conversion will have been performed on the operands at this
3136 point, so we have to dig out the original type to find out if
3138 shorten = ((TREE_CODE (op0) == NOP_EXPR
3139 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3140 || (TREE_CODE (op1) == INTEGER_CST
3141 && ! integer_all_onesp (op1)));
3150 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3151 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3155 case TRUNC_MOD_EXPR:
3156 case FLOOR_MOD_EXPR:
3157 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3158 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3159 else if (code1 == REAL_TYPE && real_zerop (op1))
3160 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3162 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3164 /* Although it would be tempting to shorten always here, that loses
3165 on some targets, since the modulo instruction is undefined if the
3166 quotient can't be represented in the computation mode. We shorten
3167 only if unsigned or if dividing by something we know != -1. */
3168 shorten = ((TREE_CODE (op0) == NOP_EXPR
3169 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3170 || (TREE_CODE (op1) == INTEGER_CST
3171 && ! integer_all_onesp (op1)));
3176 case TRUTH_ANDIF_EXPR:
3177 case TRUTH_ORIF_EXPR:
3178 case TRUTH_AND_EXPR:
3180 result_type = boolean_type_node;
3183 /* Shift operations: result has same type as first operand;
3184 always convert second operand to int.
3185 Also set SHORT_SHIFT if shifting rightward. */
3188 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3190 result_type = type0;
3191 if (TREE_CODE (op1) == INTEGER_CST)
3193 if (tree_int_cst_lt (op1, integer_zero_node))
3194 warning (0, "right shift count is negative");
3197 if (! integer_zerop (op1))
3199 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3200 warning (0, "right shift count >= width of type");
3203 /* Convert the shift-count to an integer, regardless of
3204 size of value being shifted. */
3205 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3206 op1 = cp_convert (integer_type_node, op1);
3207 /* Avoid converting op1 to result_type later. */
3213 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3215 result_type = type0;
3216 if (TREE_CODE (op1) == INTEGER_CST)
3218 if (tree_int_cst_lt (op1, integer_zero_node))
3219 warning (0, "left shift count is negative");
3220 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3221 warning (0, "left shift count >= width of type");
3223 /* Convert the shift-count to an integer, regardless of
3224 size of value being shifted. */
3225 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3226 op1 = cp_convert (integer_type_node, op1);
3227 /* Avoid converting op1 to result_type later. */
3234 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3236 result_type = type0;
3237 if (TREE_CODE (op1) == INTEGER_CST)
3239 if (tree_int_cst_lt (op1, integer_zero_node))
3240 warning (0, (code == LROTATE_EXPR)
3241 ? G_("left rotate count is negative")
3242 : G_("right rotate count is negative"));
3243 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3244 warning (0, (code == LROTATE_EXPR)
3245 ? G_("left rotate count >= width of type")
3246 : G_("right rotate count >= width of type"));
3248 /* Convert the shift-count to an integer, regardless of
3249 size of value being shifted. */
3250 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3251 op1 = cp_convert (integer_type_node, op1);
3257 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3258 warning (OPT_Wfloat_equal,
3259 "comparing floating point with == or != is unsafe");
3260 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3261 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3262 warning (OPT_Wstring_literal_comparison,
3263 "comparison with string literal");
3265 build_type = boolean_type_node;
3266 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3267 || code0 == COMPLEX_TYPE)
3268 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3269 || code1 == COMPLEX_TYPE))
3271 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3272 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3273 result_type = composite_pointer_type (type0, type1, op0, op1,
3275 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3276 && null_ptr_cst_p (op1))
3277 result_type = type0;
3278 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3279 && null_ptr_cst_p (op0))
3280 result_type = type1;
3281 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3283 result_type = type0;
3284 error ("ISO C++ forbids comparison between pointer and integer");
3286 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3288 result_type = type1;
3289 error ("ISO C++ forbids comparison between pointer and integer");
3291 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3293 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3294 == ptrmemfunc_vbit_in_delta)
3296 tree pfn0 = pfn_from_ptrmemfunc (op0);
3297 tree delta0 = build_ptrmemfunc_access_expr (op0,
3299 tree e1 = cp_build_binary_op (EQ_EXPR,
3301 fold_convert (TREE_TYPE (pfn0),
3302 integer_zero_node));
3303 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3306 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3307 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3308 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3312 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3313 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3315 result_type = TREE_TYPE (op0);
3317 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3318 return cp_build_binary_op (code, op1, op0);
3319 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3320 && same_type_p (type0, type1))
3322 /* E will be the final comparison. */
3324 /* E1 and E2 are for scratch. */
3332 if (TREE_SIDE_EFFECTS (op0))
3333 op0 = save_expr (op0);
3334 if (TREE_SIDE_EFFECTS (op1))
3335 op1 = save_expr (op1);
3337 pfn0 = pfn_from_ptrmemfunc (op0);
3338 pfn1 = pfn_from_ptrmemfunc (op1);
3339 delta0 = build_ptrmemfunc_access_expr (op0,
3341 delta1 = build_ptrmemfunc_access_expr (op1,
3343 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3344 == ptrmemfunc_vbit_in_delta)
3349 && ((op0.delta == op1.delta)
3350 || (!op0.pfn && op0.delta & 1 == 0
3351 && op1.delta & 1 == 0))
3353 The reason for the `!op0.pfn' bit is that a NULL
3354 pointer-to-member is any member with a zero PFN and
3355 LSB of the DELTA field is 0. */
3357 e1 = cp_build_binary_op (BIT_AND_EXPR,
3360 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3361 e2 = cp_build_binary_op (BIT_AND_EXPR,
3364 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3365 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3366 e2 = cp_build_binary_op (EQ_EXPR,
3368 fold_convert (TREE_TYPE (pfn0),
3369 integer_zero_node));
3370 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3371 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3372 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3379 && (!op0.pfn || op0.delta == op1.delta))
3381 The reason for the `!op0.pfn' bit is that a NULL
3382 pointer-to-member is any member with a zero PFN; the
3383 DELTA field is unspecified. */
3385 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3386 e2 = cp_build_binary_op (EQ_EXPR,
3388 fold_convert (TREE_TYPE (pfn0),
3389 integer_zero_node));
3390 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3392 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3393 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3394 if (code == EQ_EXPR)
3396 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3400 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3401 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3403 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3404 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3412 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3413 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3415 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3416 result_type = composite_pointer_type (type0, type1, op0, op1,
3424 if (TREE_CODE (orig_op0) == STRING_CST
3425 || TREE_CODE (orig_op1) == STRING_CST)
3426 warning (OPT_Wstring_literal_comparison,
3427 "comparison with string literal");
3429 build_type = boolean_type_node;
3430 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3431 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3433 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3434 result_type = composite_pointer_type (type0, type1, op0, op1,
3436 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3437 && integer_zerop (op1))
3438 result_type = type0;
3439 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3440 && integer_zerop (op0))
3441 result_type = type1;
3442 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3444 result_type = type0;
3445 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3447 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3449 result_type = type1;
3450 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3454 case UNORDERED_EXPR:
3461 build_type = integer_type_node;
3462 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3464 error ("unordered comparison on non-floating point argument");
3465 return error_mark_node;
3474 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3475 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3476 || code1 == COMPLEX_TYPE)))
3477 arithmetic_types_p = 1;
3480 arithmetic_types_p = 0;
3481 /* Vector arithmetic is only allowed when both sides are vectors. */
3482 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3484 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3485 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3488 binary_op_error (code);
3489 return error_mark_node;
3491 arithmetic_types_p = 1;
3494 /* Determine the RESULT_TYPE, if it is not already known. */
3496 && arithmetic_types_p
3497 && (shorten || common || short_compare))
3498 result_type = common_type (type0, type1);
3502 error ("invalid operands of types %qT and %qT to binary %qO",
3503 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3504 return error_mark_node;
3507 /* If we're in a template, the only thing we need to know is the
3509 if (processing_template_decl)
3510 return build2 (resultcode,
3511 build_type ? build_type : result_type,
3514 if (arithmetic_types_p)
3516 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3518 /* For certain operations (which identify themselves by shorten != 0)
3519 if both args were extended from the same smaller type,
3520 do the arithmetic in that type and then extend.
3522 shorten !=0 and !=1 indicates a bitwise operation.
3523 For them, this optimization is safe only if
3524 both args are zero-extended or both are sign-extended.
3525 Otherwise, we might change the result.
3526 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3527 but calculated in (unsigned short) it would be (unsigned short)-1. */
3529 if (shorten && none_complex)
3531 int unsigned0, unsigned1;
3532 tree arg0 = get_narrower (op0, &unsigned0);
3533 tree arg1 = get_narrower (op1, &unsigned1);
3534 /* UNS is 1 if the operation to be done is an unsigned one. */
3535 int uns = TYPE_UNSIGNED (result_type);
3538 final_type = result_type;
3540 /* Handle the case that OP0 does not *contain* a conversion
3541 but it *requires* conversion to FINAL_TYPE. */
3543 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3544 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3545 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3546 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3548 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3550 /* For bitwise operations, signedness of nominal type
3551 does not matter. Consider only how operands were extended. */
3555 /* Note that in all three cases below we refrain from optimizing
3556 an unsigned operation on sign-extended args.
3557 That would not be valid. */
3559 /* Both args variable: if both extended in same way
3560 from same width, do it in that width.
3561 Do it unsigned if args were zero-extended. */
3562 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3563 < TYPE_PRECISION (result_type))
3564 && (TYPE_PRECISION (TREE_TYPE (arg1))
3565 == TYPE_PRECISION (TREE_TYPE (arg0)))
3566 && unsigned0 == unsigned1
3567 && (unsigned0 || !uns))
3568 result_type = c_common_signed_or_unsigned_type
3569 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3570 else if (TREE_CODE (arg0) == INTEGER_CST
3571 && (unsigned1 || !uns)
3572 && (TYPE_PRECISION (TREE_TYPE (arg1))
3573 < TYPE_PRECISION (result_type))
3574 && (type = c_common_signed_or_unsigned_type
3575 (unsigned1, TREE_TYPE (arg1)),
3576 int_fits_type_p (arg0, type)))
3578 else if (TREE_CODE (arg1) == INTEGER_CST
3579 && (unsigned0 || !uns)
3580 && (TYPE_PRECISION (TREE_TYPE (arg0))
3581 < TYPE_PRECISION (result_type))
3582 && (type = c_common_signed_or_unsigned_type
3583 (unsigned0, TREE_TYPE (arg0)),
3584 int_fits_type_p (arg1, type)))
3588 /* Shifts can be shortened if shifting right. */
3593 tree arg0 = get_narrower (op0, &unsigned_arg);
3595 final_type = result_type;
3597 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3598 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3600 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3601 /* We can shorten only if the shift count is less than the
3602 number of bits in the smaller type size. */
3603 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3604 /* If arg is sign-extended and then unsigned-shifted,
3605 we can simulate this with a signed shift in arg's type
3606 only if the extended result is at least twice as wide
3607 as the arg. Otherwise, the shift could use up all the
3608 ones made by sign-extension and bring in zeros.
3609 We can't optimize that case at all, but in most machines
3610 it never happens because available widths are 2**N. */
3611 && (!TYPE_UNSIGNED (final_type)
3613 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3614 <= TYPE_PRECISION (result_type))))
3616 /* Do an unsigned shift if the operand was zero-extended. */
3618 = c_common_signed_or_unsigned_type (unsigned_arg,
3620 /* Convert value-to-be-shifted to that type. */
3621 if (TREE_TYPE (op0) != result_type)
3622 op0 = cp_convert (result_type, op0);
3627 /* Comparison operations are shortened too but differently.
3628 They identify themselves by setting short_compare = 1. */
3632 /* Don't write &op0, etc., because that would prevent op0
3633 from being kept in a register.
3634 Instead, make copies of the our local variables and
3635 pass the copies by reference, then copy them back afterward. */
3636 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3637 enum tree_code xresultcode = resultcode;
3639 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3641 return cp_convert (boolean_type_node, val);
3642 op0 = xop0, op1 = xop1;
3644 resultcode = xresultcode;
3647 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3648 && warn_sign_compare
3649 /* Do not warn until the template is instantiated; we cannot
3650 bound the ranges of the arguments until that point. */
3651 && !processing_template_decl)
3653 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3654 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3656 int unsignedp0, unsignedp1;
3657 tree primop0 = get_narrower (op0, &unsignedp0);
3658 tree primop1 = get_narrower (op1, &unsignedp1);
3660 /* Check for comparison of different enum types. */
3661 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3662 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3663 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3664 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3666 warning (0, "comparison between types %q#T and %q#T",
3667 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3670 /* Give warnings for comparisons between signed and unsigned
3671 quantities that may fail. */
3672 /* Do the checking based on the original operand trees, so that
3673 casts will be considered, but default promotions won't be. */
3675 /* Do not warn if the comparison is being done in a signed type,
3676 since the signed type will only be chosen if it can represent
3677 all the values of the unsigned type. */
3678 if (!TYPE_UNSIGNED (result_type))
3680 /* Do not warn if both operands are unsigned. */
3681 else if (op0_signed == op1_signed)
3683 /* Do not warn if the signed quantity is an unsuffixed
3684 integer literal (or some static constant expression
3685 involving such literals or a conditional expression
3686 involving such literals) and it is non-negative. */
3687 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3688 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3690 /* Do not warn if the comparison is an equality operation,
3691 the unsigned quantity is an integral constant and it does
3692 not use the most significant bit of result_type. */
3693 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3694 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3695 && int_fits_type_p (orig_op1, c_common_signed_type
3697 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3698 && int_fits_type_p (orig_op0, c_common_signed_type
3702 warning (0, "comparison between signed and unsigned integer expressions");
3704 /* Warn if two unsigned values are being compared in a size
3705 larger than their original size, and one (and only one) is the
3706 result of a `~' operator. This comparison will always fail.
3708 Also warn if one operand is a constant, and the constant does not
3709 have all bits set that are set in the ~ operand when it is
3712 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3713 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3715 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3716 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3717 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3718 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3720 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3723 HOST_WIDE_INT constant, mask;
3727 if (host_integerp (primop0, 0))
3730 unsignedp = unsignedp1;
3731 constant = tree_low_cst (primop0, 0);
3736 unsignedp = unsignedp0;
3737 constant = tree_low_cst (primop1, 0);
3740 bits = TYPE_PRECISION (TREE_TYPE (primop));
3741 if (bits < TYPE_PRECISION (result_type)
3742 && bits < HOST_BITS_PER_LONG && unsignedp)
3744 mask = (~ (HOST_WIDE_INT) 0) << bits;
3745 if ((mask & constant) != mask)
3746 warning (0, "comparison of promoted ~unsigned with constant");
3749 else if (unsignedp0 && unsignedp1
3750 && (TYPE_PRECISION (TREE_TYPE (primop0))
3751 < TYPE_PRECISION (result_type))
3752 && (TYPE_PRECISION (TREE_TYPE (primop1))
3753 < TYPE_PRECISION (result_type)))
3754 warning (0, "comparison of promoted ~unsigned with unsigned");
3759 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3760 Then the expression will be built.
3761 It will be given type FINAL_TYPE if that is nonzero;
3762 otherwise, it will be given type RESULT_TYPE. */
3764 /* Issue warnings about peculiar, but valid, uses of NULL. */
3765 if (/* It's reasonable to use pointer values as operands of &&
3766 and ||, so NULL is no exception. */
3767 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3768 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3769 (orig_op0 == null_node
3770 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3771 /* Or vice versa. */
3772 || (orig_op1 == null_node
3773 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3774 /* Or, both are NULL and the operation was not a comparison. */
3775 || (orig_op0 == null_node && orig_op1 == null_node
3776 && code != EQ_EXPR && code != NE_EXPR)))
3777 /* Some sort of arithmetic operation involving NULL was
3778 performed. Note that pointer-difference and pointer-addition
3779 have already been handled above, and so we don't end up here in
3781 warning (0, "NULL used in arithmetic");
3785 if (TREE_TYPE (op0) != result_type)
3786 op0 = cp_convert (result_type, op0);
3787 if (TREE_TYPE (op1) != result_type)
3788 op1 = cp_convert (result_type, op1);
3790 if (op0 == error_mark_node || op1 == error_mark_node)
3791 return error_mark_node;
3794 if (build_type == NULL_TREE)
3795 build_type = result_type;
3797 result = build2 (resultcode, build_type, op0, op1);
3798 result = fold_if_not_in_template (result);
3799 if (final_type != 0)
3800 result = cp_convert (final_type, result);
3804 /* Return a tree for the sum or difference (RESULTCODE says which)
3805 of pointer PTROP and integer INTOP. */
3808 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3810 tree res_type = TREE_TYPE (ptrop);
3812 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3813 in certain circumstance (when it's valid to do so). So we need
3814 to make sure it's complete. We don't need to check here, if we
3815 can actually complete it at all, as those checks will be done in
3816 pointer_int_sum() anyway. */
3817 complete_type (TREE_TYPE (res_type));
3819 return pointer_int_sum (resultcode, ptrop,
3820 fold_if_not_in_template (intop));
3823 /* Return a tree for the difference of pointers OP0 and OP1.
3824 The resulting tree has type int. */
3827 pointer_diff (tree op0, tree op1, tree ptrtype)
3830 tree restype = ptrdiff_type_node;
3831 tree target_type = TREE_TYPE (ptrtype);
3833 if (!complete_type_or_else (target_type, NULL_TREE))
3834 return error_mark_node;
3836 if (pedantic || warn_pointer_arith)
3838 if (TREE_CODE (target_type) == VOID_TYPE)
3839 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3840 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3841 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3842 if (TREE_CODE (target_type) == METHOD_TYPE)
3843 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3846 /* First do the subtraction as integers;
3847 then drop through to build the divide operator. */
3849 op0 = cp_build_binary_op (MINUS_EXPR,
3850 cp_convert (restype, op0),
3851 cp_convert (restype, op1));
3853 /* This generates an error if op1 is a pointer to an incomplete type. */
3854 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3855 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3857 op1 = (TYPE_PTROB_P (ptrtype)
3858 ? size_in_bytes (target_type)
3859 : integer_one_node);
3861 /* Do the division. */
3863 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3864 return fold_if_not_in_template (result);
3867 /* Construct and perhaps optimize a tree representation
3868 for a unary operation. CODE, a tree_code, specifies the operation
3869 and XARG is the operand. */
3872 build_x_unary_op (enum tree_code code, tree xarg)
3874 tree orig_expr = xarg;
3878 if (processing_template_decl)
3880 if (type_dependent_expression_p (xarg))
3881 return build_min_nt (code, xarg, NULL_TREE);
3883 xarg = build_non_dependent_expr (xarg);
3888 /* [expr.unary.op] says:
3890 The address of an object of incomplete type can be taken.
3892 (And is just the ordinary address operator, not an overloaded
3893 "operator &".) However, if the type is a template
3894 specialization, we must complete the type at this point so that
3895 an overloaded "operator &" will be available if required. */
3896 if (code == ADDR_EXPR
3897 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3898 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3899 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3900 || (TREE_CODE (xarg) == OFFSET_REF)))
3901 /* Don't look for a function. */;
3903 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3904 /*overloaded_p=*/NULL);
3905 if (!exp && code == ADDR_EXPR)
3907 /* A pointer to member-function can be formed only by saying
3909 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3910 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3912 if (TREE_CODE (xarg) != OFFSET_REF
3913 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3915 error ("invalid use of %qE to form a pointer-to-member-function",
3917 if (TREE_CODE (xarg) != OFFSET_REF)
3918 inform (" a qualified-id is required");
3919 return error_mark_node;
3923 error ("parentheses around %qE cannot be used to form a"
3924 " pointer-to-member-function",
3926 PTRMEM_OK_P (xarg) = 1;
3930 if (TREE_CODE (xarg) == OFFSET_REF)
3932 ptrmem = PTRMEM_OK_P (xarg);
3934 if (!ptrmem && !flag_ms_extensions
3935 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3937 /* A single non-static member, make sure we don't allow a
3938 pointer-to-member. */
3939 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3940 TREE_OPERAND (xarg, 0),
3941 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3942 PTRMEM_OK_P (xarg) = ptrmem;
3945 else if (TREE_CODE (xarg) == TARGET_EXPR)
3946 warning (0, "taking address of temporary");
3947 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3950 if (processing_template_decl && exp != error_mark_node)
3951 exp = build_min_non_dep (code, exp, orig_expr,
3952 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3953 if (TREE_CODE (exp) == ADDR_EXPR)
3954 PTRMEM_OK_P (exp) = ptrmem;
3958 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3959 constants, where a null value is represented by an INTEGER_CST of
3963 cp_truthvalue_conversion (tree expr)
3965 tree type = TREE_TYPE (expr);
3966 if (TYPE_PTRMEM_P (type))
3967 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3969 return c_common_truthvalue_conversion (expr);
3972 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3975 condition_conversion (tree expr)
3978 if (processing_template_decl)
3980 t = perform_implicit_conversion (boolean_type_node, expr);
3981 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3985 /* Return an ADDR_EXPR giving the address of T. This function
3986 attempts no optimizations or simplifications; it is a low-level
3990 build_address (tree t)
3994 if (error_operand_p (t) || !cxx_mark_addressable (t))
3995 return error_mark_node;
3997 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
4002 /* Return a NOP_EXPR converting EXPR to TYPE. */
4005 build_nop (tree type, tree expr)
4007 if (type == error_mark_node || error_operand_p (expr))
4009 return build1 (NOP_EXPR, type, expr);
4012 /* C++: Must handle pointers to members.
4014 Perhaps type instantiation should be extended to handle conversion
4015 from aggregates to types we don't yet know we want? (Or are those
4016 cases typically errors which should be reported?)
4018 NOCONVERT nonzero suppresses the default promotions
4019 (such as from short to int). */
4022 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4024 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4027 const char *errstring = NULL;
4029 const char *invalid_op_diag;
4031 if (arg == error_mark_node)
4032 return error_mark_node;
4034 if ((invalid_op_diag
4035 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4040 error (invalid_op_diag);
4041 return error_mark_node;
4046 case UNARY_PLUS_EXPR:
4049 int flags = WANT_ARITH | WANT_ENUM;
4050 /* Unary plus (but not unary minus) is allowed on pointers. */
4051 if (code == UNARY_PLUS_EXPR)
4052 flags |= WANT_POINTER;
4053 arg = build_expr_type_conversion (flags, arg, true);
4055 errstring = (code == NEGATE_EXPR
4056 ? "wrong type argument to unary minus"
4057 : "wrong type argument to unary plus");
4060 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4061 arg = perform_integral_promotions (arg);
4063 /* Make sure the result is not an lvalue: a unary plus or minus
4064 expression is always a rvalue. */
4071 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4075 arg = default_conversion (arg);
4077 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4080 errstring = "wrong type argument to bit-complement";
4081 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4082 arg = perform_integral_promotions (arg);
4086 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4087 errstring = "wrong type argument to abs";
4088 else if (!noconvert)
4089 arg = default_conversion (arg);
4093 /* Conjugating a real value is a no-op, but allow it anyway. */
4094 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4095 errstring = "wrong type argument to conjugation";
4096 else if (!noconvert)
4097 arg = default_conversion (arg);
4100 case TRUTH_NOT_EXPR:
4101 arg = perform_implicit_conversion (boolean_type_node, arg);
4102 val = invert_truthvalue (arg);
4103 if (arg != error_mark_node)
4105 errstring = "in argument to unary !";
4112 if (TREE_CODE (arg) == COMPLEX_CST)
4113 return TREE_REALPART (arg);
4114 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4116 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4117 return fold_if_not_in_template (arg);
4123 if (TREE_CODE (arg) == COMPLEX_CST)
4124 return TREE_IMAGPART (arg);
4125 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4127 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4128 return fold_if_not_in_template (arg);
4131 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4133 case PREINCREMENT_EXPR:
4134 case POSTINCREMENT_EXPR:
4135 case PREDECREMENT_EXPR:
4136 case POSTDECREMENT_EXPR:
4137 /* Handle complex lvalues (when permitted)
4138 by reduction to simpler cases. */
4140 val = unary_complex_lvalue (code, arg);
4144 /* Increment or decrement the real part of the value,
4145 and don't change the imaginary part. */
4146 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4150 arg = stabilize_reference (arg);
4151 real = build_unary_op (REALPART_EXPR, arg, 1);
4152 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4153 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4154 build_unary_op (code, real, 1), imag);
4157 /* Report invalid types. */
4159 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4162 if (code == PREINCREMENT_EXPR)
4163 errstring ="no pre-increment operator for type";
4164 else if (code == POSTINCREMENT_EXPR)
4165 errstring ="no post-increment operator for type";
4166 else if (code == PREDECREMENT_EXPR)
4167 errstring ="no pre-decrement operator for type";
4169 errstring ="no post-decrement operator for type";
4173 /* Report something read-only. */
4175 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4176 || TREE_READONLY (arg))
4177 readonly_error (arg, ((code == PREINCREMENT_EXPR
4178 || code == POSTINCREMENT_EXPR)
4179 ? "increment" : "decrement"),
4184 tree result_type = TREE_TYPE (arg);
4186 arg = get_unwidened (arg, 0);
4187 argtype = TREE_TYPE (arg);
4189 /* ARM $5.2.5 last annotation says this should be forbidden. */
4190 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4191 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4192 ? G_("ISO C++ forbids incrementing an enum")
4193 : G_("ISO C++ forbids decrementing an enum"));
4195 /* Compute the increment. */
4197 if (TREE_CODE (argtype) == POINTER_TYPE)
4199 tree type = complete_type (TREE_TYPE (argtype));
4201 if (!COMPLETE_OR_VOID_TYPE_P (type))
4202 error (((code == PREINCREMENT_EXPR
4203 || code == POSTINCREMENT_EXPR))
4204 ? G_("cannot increment a pointer to incomplete type %qT")
4205 : G_("cannot decrement a pointer to incomplete type %qT"),
4206 TREE_TYPE (argtype));
4207 else if ((pedantic || warn_pointer_arith)
4208 && !TYPE_PTROB_P (argtype))
4209 pedwarn ((code == PREINCREMENT_EXPR
4210 || code == POSTINCREMENT_EXPR)
4211 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4212 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4214 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4217 inc = integer_one_node;
4219 inc = cp_convert (argtype, inc);
4221 /* Handle incrementing a cast-expression. */
4223 switch (TREE_CODE (arg))
4228 case FIX_TRUNC_EXPR:
4230 tree incremented, modify, value, compound;
4231 if (! lvalue_p (arg) && pedantic)
4232 pedwarn ("cast to non-reference type used as lvalue");
4233 arg = stabilize_reference (arg);
4234 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4237 value = save_expr (arg);
4238 incremented = build2 (((code == PREINCREMENT_EXPR
4239 || code == POSTINCREMENT_EXPR)
4240 ? PLUS_EXPR : MINUS_EXPR),
4241 argtype, value, inc);
4243 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4244 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4247 /* Eliminate warning about unused result of + or -. */
4248 TREE_NO_WARNING (compound) = 1;
4256 /* Complain about anything else that is not a true lvalue. */
4257 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4258 || code == POSTINCREMENT_EXPR)
4259 ? lv_increment : lv_decrement)))
4260 return error_mark_node;
4262 /* Forbid using -- on `bool'. */
4263 if (same_type_p (TREE_TYPE (arg), boolean_type_node))
4265 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4267 error ("invalid use of %<--%> on bool variable %qD", arg);
4268 return error_mark_node;
4270 val = boolean_increment (code, arg);
4273 val = build2 (code, TREE_TYPE (arg), arg, inc);
4275 TREE_SIDE_EFFECTS (val) = 1;
4276 return cp_convert (result_type, val);
4280 /* Note that this operation never does default_conversion
4281 regardless of NOCONVERT. */
4283 argtype = lvalue_type (arg);
4285 if (TREE_CODE (arg) == OFFSET_REF)
4288 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4290 tree type = build_pointer_type (TREE_TYPE (argtype));
4291 arg = build1 (CONVERT_EXPR, type, arg);
4294 else if (pedantic && DECL_MAIN_P (arg))
4296 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4298 /* Let &* cancel out to simplify resulting code. */
4299 if (TREE_CODE (arg) == INDIRECT_REF)
4301 /* We don't need to have `current_class_ptr' wrapped in a
4302 NON_LVALUE_EXPR node. */
4303 if (arg == current_class_ref)
4304 return current_class_ptr;
4306 arg = TREE_OPERAND (arg, 0);
4307 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4309 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4310 arg = build1 (CONVERT_EXPR, type, arg);
4313 /* Don't let this be an lvalue. */
4318 /* Uninstantiated types are all functions. Taking the
4319 address of a function is a no-op, so just return the
4322 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4323 || !IDENTIFIER_OPNAME_P (arg));
4325 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4326 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4328 /* They're trying to take the address of a unique non-static
4329 member function. This is ill-formed (except in MS-land),
4330 but let's try to DTRT.
4331 Note: We only handle unique functions here because we don't
4332 want to complain if there's a static overload; non-unique
4333 cases will be handled by instantiate_type. But we need to
4334 handle this case here to allow casts on the resulting PMF.
4335 We could defer this in non-MS mode, but it's easier to give
4336 a useful error here. */
4338 /* Inside constant member functions, the `this' pointer
4339 contains an extra const qualifier. TYPE_MAIN_VARIANT
4340 is used here to remove this const from the diagnostics
4341 and the created OFFSET_REF. */
4342 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4343 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4346 if (! flag_ms_extensions)
4348 tree name = DECL_NAME (fn);
4349 if (current_class_type
4350 && TREE_OPERAND (arg, 0) == current_class_ref)
4351 /* An expression like &memfn. */
4352 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4353 " or parenthesized non-static member function to form"
4354 " a pointer to member function. Say %<&%T::%D%>",
4357 pedwarn ("ISO C++ forbids taking the address of a bound member"
4358 " function to form a pointer to member function."
4362 arg = build_offset_ref (base, fn, /*address_p=*/true);
4366 if (type_unknown_p (arg))
4367 return build1 (ADDR_EXPR, unknown_type_node, arg);
4369 /* Handle complex lvalues (when permitted)
4370 by reduction to simpler cases. */
4371 val = unary_complex_lvalue (code, arg);
4375 switch (TREE_CODE (arg))
4380 case FIX_TRUNC_EXPR:
4381 if (! lvalue_p (arg) && pedantic)
4382 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4386 arg = BASELINK_FUNCTIONS (arg);
4390 arg = OVL_CURRENT (arg);
4394 /* Turn a reference to a non-static data member into a
4395 pointer-to-member. */
4400 if (!PTRMEM_OK_P (arg))
4401 return build_unary_op (code, arg, 0);
4403 t = TREE_OPERAND (arg, 1);
4404 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4406 error ("cannot create pointer to reference member %qD", t);
4407 return error_mark_node;
4410 type = build_ptrmem_type (context_for_name_lookup (t),
4412 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4420 /* Anything not already handled and not a true memory reference
4422 if (TREE_CODE (argtype) != FUNCTION_TYPE
4423 && TREE_CODE (argtype) != METHOD_TYPE
4424 && TREE_CODE (arg) != OFFSET_REF
4425 && !lvalue_or_else (arg, lv_addressof))
4426 return error_mark_node;
4428 if (argtype != error_mark_node)
4429 argtype = build_pointer_type (argtype);
4431 /* In a template, we are processing a non-dependent expression
4432 so we can just form an ADDR_EXPR with the correct type. */
4433 if (processing_template_decl)
4435 val = build_address (arg);
4436 if (TREE_CODE (arg) == OFFSET_REF)
4437 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4441 if (TREE_CODE (arg) != COMPONENT_REF)
4443 val = build_address (arg);
4444 if (TREE_CODE (arg) == OFFSET_REF)
4445 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4447 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4449 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4451 /* We can only get here with a single static member
4453 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4454 && DECL_STATIC_FUNCTION_P (fn));
4456 val = build_address (fn);
4457 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4458 /* Do not lose object's side effects. */
4459 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4460 TREE_OPERAND (arg, 0), val);
4462 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4464 error ("attempt to take address of bit-field structure member %qD",
4465 TREE_OPERAND (arg, 1));
4466 return error_mark_node;
4470 tree object = TREE_OPERAND (arg, 0);
4471 tree field = TREE_OPERAND (arg, 1);
4472 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4473 (TREE_TYPE (object), decl_type_context (field)));
4474 val = build_address (arg);
4477 if (TREE_CODE (argtype) == POINTER_TYPE
4478 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4480 build_ptrmemfunc_type (argtype);
4481 val = build_ptrmemfunc (argtype, val, 0,
4482 /*c_cast_p=*/false);
4494 argtype = TREE_TYPE (arg);
4495 return fold_if_not_in_template (build1 (code, argtype, arg));
4498 error ("%s", errstring);
4499 return error_mark_node;
4502 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4503 for certain kinds of expressions which are not really lvalues
4504 but which we can accept as lvalues.
4506 If ARG is not a kind of expression we can handle, return
4510 unary_complex_lvalue (enum tree_code code, tree arg)
4512 /* Inside a template, making these kinds of adjustments is
4513 pointless; we are only concerned with the type of the
4515 if (processing_template_decl)
4518 /* Handle (a, b) used as an "lvalue". */
4519 if (TREE_CODE (arg) == COMPOUND_EXPR)
4521 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4522 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4523 TREE_OPERAND (arg, 0), real_result);
4526 /* Handle (a ? b : c) used as an "lvalue". */
4527 if (TREE_CODE (arg) == COND_EXPR
4528 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4529 return rationalize_conditional_expr (code, arg);
4531 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4532 if (TREE_CODE (arg) == MODIFY_EXPR
4533 || TREE_CODE (arg) == PREINCREMENT_EXPR
4534 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4536 tree lvalue = TREE_OPERAND (arg, 0);
4537 if (TREE_SIDE_EFFECTS (lvalue))
4539 lvalue = stabilize_reference (lvalue);
4540 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4541 lvalue, TREE_OPERAND (arg, 1));
4543 return unary_complex_lvalue
4544 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4547 if (code != ADDR_EXPR)
4550 /* Handle (a = b) used as an "lvalue" for `&'. */
4551 if (TREE_CODE (arg) == MODIFY_EXPR
4552 || TREE_CODE (arg) == INIT_EXPR)
4554 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4555 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4557 TREE_NO_WARNING (arg) = 1;
4561 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4562 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4563 || TREE_CODE (arg) == OFFSET_REF)
4566 /* We permit compiler to make function calls returning
4567 objects of aggregate type look like lvalues. */
4571 if (TREE_CODE (targ) == SAVE_EXPR)
4572 targ = TREE_OPERAND (targ, 0);
4574 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4576 if (TREE_CODE (arg) == SAVE_EXPR)
4579 targ = build_cplus_new (TREE_TYPE (arg), arg);
4580 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4583 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4584 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4585 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4588 /* Don't let anything else be handled specially. */
4592 /* Mark EXP saying that we need to be able to take the
4593 address of it; it should not be allocated in a register.
4594 Value is true if successful.
4596 C++: we do not allow `current_class_ptr' to be addressable. */
4599 cxx_mark_addressable (tree exp)
4604 switch (TREE_CODE (x))
4611 x = TREE_OPERAND (x, 0);
4615 if (x == current_class_ptr)
4617 error ("cannot take the address of %<this%>, which is an rvalue expression");
4618 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4624 /* Caller should not be trying to mark initialized
4625 constant fields addressable. */
4626 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4627 || DECL_IN_AGGR_P (x) == 0
4629 || DECL_EXTERNAL (x));
4634 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4635 && !DECL_ARTIFICIAL (x))
4637 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4640 ("address of explicit register variable %qD requested", x);
4643 else if (extra_warnings)
4645 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4647 TREE_ADDRESSABLE (x) = 1;
4651 TREE_ADDRESSABLE (x) = 1;
4655 TREE_ADDRESSABLE (x) = 1;
4659 TREE_ADDRESSABLE (x) = 1;
4660 cxx_mark_addressable (TREE_OPERAND (x, 0));
4668 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4671 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4673 tree orig_ifexp = ifexp;
4674 tree orig_op1 = op1;
4675 tree orig_op2 = op2;
4678 if (processing_template_decl)
4680 /* The standard says that the expression is type-dependent if
4681 IFEXP is type-dependent, even though the eventual type of the
4682 expression doesn't dependent on IFEXP. */
4683 if (type_dependent_expression_p (ifexp)
4684 /* As a GNU extension, the middle operand may be omitted. */
4685 || (op1 && type_dependent_expression_p (op1))
4686 || type_dependent_expression_p (op2))
4687 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4688 ifexp = build_non_dependent_expr (ifexp);
4690 op1 = build_non_dependent_expr (op1);
4691 op2 = build_non_dependent_expr (op2);
4694 expr = build_conditional_expr (ifexp, op1, op2);
4695 if (processing_template_decl && expr != error_mark_node)
4696 return build_min_non_dep (COND_EXPR, expr,
4697 orig_ifexp, orig_op1, orig_op2);
4701 /* Given a list of expressions, return a compound expression
4702 that performs them all and returns the value of the last of them. */
4704 tree build_x_compound_expr_from_list (tree list, const char *msg)
4706 tree expr = TREE_VALUE (list);
4708 if (TREE_CHAIN (list))
4711 pedwarn ("%s expression list treated as compound expression", msg);
4713 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4714 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4720 /* Handle overloading of the ',' operator when needed. */
4723 build_x_compound_expr (tree op1, tree op2)
4726 tree orig_op1 = op1;
4727 tree orig_op2 = op2;
4729 if (processing_template_decl)
4731 if (type_dependent_expression_p (op1)
4732 || type_dependent_expression_p (op2))
4733 return build_min_nt (COMPOUND_EXPR, op1, op2);
4734 op1 = build_non_dependent_expr (op1);
4735 op2 = build_non_dependent_expr (op2);
4738 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4739 /*overloaded_p=*/NULL);
4741 result = build_compound_expr (op1, op2);
4743 if (processing_template_decl && result != error_mark_node)
4744 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4749 /* Build a compound expression. */
4752 build_compound_expr (tree lhs, tree rhs)
4754 lhs = convert_to_void (lhs, "left-hand operand of comma");
4756 if (lhs == error_mark_node || rhs == error_mark_node)
4757 return error_mark_node;
4759 if (TREE_CODE (rhs) == TARGET_EXPR)
4761 /* If the rhs is a TARGET_EXPR, then build the compound
4762 expression inside the target_expr's initializer. This
4763 helps the compiler to eliminate unnecessary temporaries. */
4764 tree init = TREE_OPERAND (rhs, 1);
4766 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4767 TREE_OPERAND (rhs, 1) = init;
4772 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4775 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4776 casts away constness. DIAG_FN gives the function to call if we
4777 need to issue a diagnostic; if it is NULL, no diagnostic will be
4778 issued. DESCRIPTION explains what operation is taking place. */
4781 check_for_casting_away_constness (tree src_type, tree dest_type,
4782 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4783 const char *description)
4785 if (diag_fn && casts_away_constness (src_type, dest_type))
4786 diag_fn ("%s from type %qT to type %qT casts away constness",
4787 description, src_type, dest_type);
4790 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4791 (another pointer-to-member type in the same hierarchy) and return
4792 the converted expression. If ALLOW_INVERSE_P is permitted, a
4793 pointer-to-derived may be converted to pointer-to-base; otherwise,
4794 only the other direction is permitted. If C_CAST_P is true, this
4795 conversion is taking place as part of a C-style cast. */
4798 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4801 if (TYPE_PTRMEM_P (type))
4805 if (TREE_CODE (expr) == PTRMEM_CST)
4806 expr = cplus_expand_constant (expr);
4807 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4808 TYPE_PTRMEM_CLASS_TYPE (type),
4811 if (!integer_zerop (delta))
4812 expr = cp_build_binary_op (PLUS_EXPR,
4813 build_nop (ptrdiff_type_node, expr),
4815 return build_nop (type, expr);
4818 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4819 allow_inverse_p, c_cast_p);
4822 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4823 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4824 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4827 ignore_overflows (tree expr, tree orig)
4829 if (TREE_CODE (expr) == INTEGER_CST
4830 && CONSTANT_CLASS_P (orig)
4831 && TREE_CODE (orig) != STRING_CST
4832 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4833 || TREE_CONSTANT_OVERFLOW (expr)
4834 != TREE_CONSTANT_OVERFLOW (orig)))
4836 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4837 /* Ensure constant sharing. */
4838 expr = build_int_cst_wide (TREE_TYPE (expr),
4839 TREE_INT_CST_LOW (expr),
4840 TREE_INT_CST_HIGH (expr));
4843 /* Avoid clobbering a shared constant. */
4844 expr = copy_node (expr);
4845 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4846 TREE_CONSTANT_OVERFLOW (expr)
4847 = TREE_CONSTANT_OVERFLOW (orig);
4853 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4854 this static_cast is being attempted as one of the possible casts
4855 allowed by a C-style cast. (In that case, accessibility of base
4856 classes is not considered, and it is OK to cast away
4857 constness.) Return the result of the cast. *VALID_P is set to
4858 indicate whether or not the cast was valid. */
4861 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4867 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4870 /* Assume the cast is valid. */
4873 intype = TREE_TYPE (expr);
4875 /* Save casted types in the function's used types hash table. */
4876 used_types_insert (type);
4878 /* Determine what to do when casting away constness. */
4881 /* C-style casts are allowed to cast away constness. With
4882 WARN_CAST_QUAL, we still want to issue a warning. */
4883 diag_fn = warn_cast_qual ? warning0 : NULL;
4888 /* A static_cast may not cast away constness. */
4890 desc = "static_cast";
4893 /* [expr.static.cast]
4895 An lvalue of type "cv1 B", where B is a class type, can be cast
4896 to type "reference to cv2 D", where D is a class derived (clause
4897 _class.derived_) from B, if a valid standard conversion from
4898 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4899 same cv-qualification as, or greater cv-qualification than, cv1,
4900 and B is not a virtual base class of D. */
4901 /* We check this case before checking the validity of "TYPE t =
4902 EXPR;" below because for this case:
4905 struct D : public B { D(const B&); };
4907 void f() { static_cast<const D&>(b); }
4909 we want to avoid constructing a new D. The standard is not
4910 completely clear about this issue, but our interpretation is
4911 consistent with other compilers. */
4912 if (TREE_CODE (type) == REFERENCE_TYPE
4913 && CLASS_TYPE_P (TREE_TYPE (type))
4914 && CLASS_TYPE_P (intype)
4915 && real_lvalue_p (expr)
4916 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4917 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4918 build_pointer_type (TYPE_MAIN_VARIANT
4919 (TREE_TYPE (type))))
4921 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4925 /* There is a standard conversion from "D*" to "B*" even if "B"
4926 is ambiguous or inaccessible. If this is really a
4927 static_cast, then we check both for inaccessibility and
4928 ambiguity. However, if this is a static_cast being performed
4929 because the user wrote a C-style cast, then accessibility is
4931 base = lookup_base (TREE_TYPE (type), intype,
4932 c_cast_p ? ba_unique : ba_check,
4935 /* Convert from "B*" to "D*". This function will check that "B"
4936 is not a virtual base of "D". */
4937 expr = build_base_path (MINUS_EXPR, build_address (expr),
4938 base, /*nonnull=*/false);
4939 /* Convert the pointer to a reference -- but then remember that
4940 there are no expressions with reference type in C++. */
4941 return convert_from_reference (build_nop (type, expr));
4946 /* [expr.static.cast]
4948 An expression e can be explicitly converted to a type T using a
4949 static_cast of the form static_cast<T>(e) if the declaration T
4950 t(e);" is well-formed, for some invented temporary variable
4952 result = perform_direct_initialization_if_possible (type, expr,
4956 result = convert_from_reference (result);
4958 /* Ignore any integer overflow caused by the cast. */
4959 result = ignore_overflows (result, orig);
4961 /* [expr.static.cast]
4963 If T is a reference type, the result is an lvalue; otherwise,
4964 the result is an rvalue. */
4965 if (TREE_CODE (type) != REFERENCE_TYPE)
4966 result = rvalue (result);
4970 /* [expr.static.cast]
4972 Any expression can be explicitly converted to type cv void. */
4973 if (TREE_CODE (type) == VOID_TYPE)
4974 return convert_to_void (expr, /*implicit=*/NULL);
4976 /* [expr.static.cast]
4978 The inverse of any standard conversion sequence (clause _conv_),
4979 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4980 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4981 (_conv.bool_) conversions, can be performed explicitly using
4982 static_cast subject to the restriction that the explicit
4983 conversion does not cast away constness (_expr.const.cast_), and
4984 the following additional rules for specific cases: */
4985 /* For reference, the conversions not excluded are: integral
4986 promotions, floating point promotion, integral conversions,
4987 floating point conversions, floating-integral conversions,
4988 pointer conversions, and pointer to member conversions. */
4991 A value of integral _or enumeration_ type can be explicitly
4992 converted to an enumeration type. */
4993 /* The effect of all that is that any conversion between any two
4994 types which are integral, floating, or enumeration types can be
4996 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4997 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4999 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5001 /* Ignore any integer overflow caused by the cast. */
5002 expr = ignore_overflows (expr, orig);
5006 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5007 && CLASS_TYPE_P (TREE_TYPE (type))
5008 && CLASS_TYPE_P (TREE_TYPE (intype))
5009 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5010 (TREE_TYPE (intype))),
5011 build_pointer_type (TYPE_MAIN_VARIANT
5012 (TREE_TYPE (type)))))
5017 check_for_casting_away_constness (intype, type, diag_fn, desc);
5018 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5019 c_cast_p ? ba_unique : ba_check,
5021 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5024 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5025 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5032 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5033 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5035 if (TYPE_PTRMEM_P (type))
5037 t1 = (build_ptrmem_type
5039 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5040 t2 = (build_ptrmem_type
5042 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5049 if (can_convert (t1, t2))
5052 check_for_casting_away_constness (intype, type, diag_fn,
5054 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5059 /* [expr.static.cast]
5061 An rvalue of type "pointer to cv void" can be explicitly
5062 converted to a pointer to object type. A value of type pointer
5063 to object converted to "pointer to cv void" and back to the
5064 original pointer type will have its original value. */
5065 if (TREE_CODE (intype) == POINTER_TYPE
5066 && VOID_TYPE_P (TREE_TYPE (intype))
5067 && TYPE_PTROB_P (type))
5070 check_for_casting_away_constness (intype, type, diag_fn, desc);
5071 return build_nop (type, expr);
5075 return error_mark_node;
5078 /* Return an expression representing static_cast<TYPE>(EXPR). */
5081 build_static_cast (tree type, tree expr)
5086 if (type == error_mark_node || expr == error_mark_node)
5087 return error_mark_node;
5089 if (processing_template_decl)
5091 expr = build_min (STATIC_CAST_EXPR, type, expr);
5092 /* We don't know if it will or will not have side effects. */
5093 TREE_SIDE_EFFECTS (expr) = 1;
5094 return convert_from_reference (expr);
5097 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5098 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5099 if (TREE_CODE (type) != REFERENCE_TYPE
5100 && TREE_CODE (expr) == NOP_EXPR
5101 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5102 expr = TREE_OPERAND (expr, 0);
5104 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5108 error ("invalid static_cast from type %qT to type %qT",
5109 TREE_TYPE (expr), type);
5110 return error_mark_node;
5113 /* EXPR is an expression with member function or pointer-to-member
5114 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5115 not permitted by ISO C++, but we accept it in some modes. If we
5116 are not in one of those modes, issue a diagnostic. Return the
5117 converted expression. */
5120 convert_member_func_to_ptr (tree type, tree expr)
5125 intype = TREE_TYPE (expr);
5126 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5127 || TREE_CODE (intype) == METHOD_TYPE);
5129 if (pedantic || warn_pmf2ptr)
5130 pedwarn ("converting from %qT to %qT", intype, type);
5132 if (TREE_CODE (intype) == METHOD_TYPE)
5133 expr = build_addr_func (expr);
5134 else if (TREE_CODE (expr) == PTRMEM_CST)
5135 expr = build_address (PTRMEM_CST_MEMBER (expr));
5138 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5139 decl = build_address (decl);
5140 expr = get_member_function_from_ptrfunc (&decl, expr);
5143 return build_nop (type, expr);
5146 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5147 If C_CAST_P is true, this reinterpret cast is being done as part of
5148 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5149 indicate whether or not reinterpret_cast was valid. */
5152 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5157 /* Assume the cast is invalid. */
5161 if (type == error_mark_node || error_operand_p (expr))
5162 return error_mark_node;
5164 intype = TREE_TYPE (expr);
5166 /* Save casted types in the function's used types hash table. */
5167 used_types_insert (type);
5169 /* [expr.reinterpret.cast]
5170 An lvalue expression of type T1 can be cast to the type
5171 "reference to T2" if an expression of type "pointer to T1" can be
5172 explicitly converted to the type "pointer to T2" using a
5173 reinterpret_cast. */
5174 if (TREE_CODE (type) == REFERENCE_TYPE)
5176 if (! real_lvalue_p (expr))
5178 error ("invalid cast of an rvalue expression of type "
5181 return error_mark_node;
5184 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5185 "B" are related class types; the reinterpret_cast does not
5186 adjust the pointer. */
5187 if (TYPE_PTR_P (intype)
5188 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5189 COMPARE_BASE | COMPARE_DERIVED)))
5190 warning (0, "casting %qT to %qT does not dereference pointer",
5193 expr = build_unary_op (ADDR_EXPR, expr, 0);
5194 if (expr != error_mark_node)
5195 expr = build_reinterpret_cast_1
5196 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5198 if (expr != error_mark_node)
5199 expr = build_indirect_ref (expr, 0);
5203 /* As a G++ extension, we consider conversions from member
5204 functions, and pointers to member functions to
5205 pointer-to-function and pointer-to-void types. If
5206 -Wno-pmf-conversions has not been specified,
5207 convert_member_func_to_ptr will issue an error message. */
5208 if ((TYPE_PTRMEMFUNC_P (intype)
5209 || TREE_CODE (intype) == METHOD_TYPE)
5210 && TYPE_PTR_P (type)
5211 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5212 || VOID_TYPE_P (TREE_TYPE (type))))
5213 return convert_member_func_to_ptr (type, expr);
5215 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5216 array-to-pointer, and function-to-pointer conversions are
5218 expr = decay_conversion (expr);
5220 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5221 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5222 if (TREE_CODE (expr) == NOP_EXPR
5223 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5224 expr = TREE_OPERAND (expr, 0);
5226 if (error_operand_p (expr))
5227 return error_mark_node;
5229 intype = TREE_TYPE (expr);
5231 /* [expr.reinterpret.cast]
5232 A pointer can be converted to any integral type large enough to
5234 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5236 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5237 pedwarn ("cast from %qT to %qT loses precision",
5240 /* [expr.reinterpret.cast]
5241 A value of integral or enumeration type can be explicitly
5242 converted to a pointer. */
5243 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5246 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5247 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5248 return fold_if_not_in_template (build_nop (type, expr));
5249 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5250 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5255 check_for_casting_away_constness (intype, type, error,
5256 "reinterpret_cast");
5257 /* Warn about possible alignment problems. */
5258 if (STRICT_ALIGNMENT && warn_cast_align
5259 && !VOID_TYPE_P (type)
5260 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5261 && COMPLETE_TYPE_P (TREE_TYPE (type))
5262 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5263 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5264 warning (0, "cast from %qT to %qT increases required alignment of "
5268 /* We need to strip nops here, because the frontend likes to
5269 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5271 strict_aliasing_warning (intype, type, sexpr);
5273 return fold_if_not_in_template (build_nop (type, expr));
5275 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5276 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5279 /* Only issue a warning, as we have always supported this
5280 where possible, and it is necessary in some cases. DR 195
5281 addresses this issue, but as of 2004/10/26 is still in
5283 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5284 return fold_if_not_in_template (build_nop (type, expr));
5286 else if (TREE_CODE (type) == VECTOR_TYPE)
5287 return fold_if_not_in_template (convert_to_vector (type, expr));
5288 else if (TREE_CODE (intype) == VECTOR_TYPE)
5289 return fold_if_not_in_template (convert_to_integer (type, expr));
5294 error ("invalid cast from type %qT to type %qT", intype, type);
5295 return error_mark_node;
5298 return cp_convert (type, expr);
5302 build_reinterpret_cast (tree type, tree expr)
5304 if (type == error_mark_node || expr == error_mark_node)
5305 return error_mark_node;
5307 if (processing_template_decl)
5309 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5311 if (!TREE_SIDE_EFFECTS (t)
5312 && type_dependent_expression_p (expr))
5313 /* There might turn out to be side effects inside expr. */
5314 TREE_SIDE_EFFECTS (t) = 1;
5315 return convert_from_reference (t);
5318 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5322 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5323 return an appropriate expression. Otherwise, return
5324 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5325 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5326 performing a C-style cast, its value upon return will indicate
5327 whether or not the conversion succeeded. */
5330 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5334 tree reference_type;
5336 /* Callers are responsible for handling error_mark_node as a
5337 destination type. */
5338 gcc_assert (dst_type != error_mark_node);
5339 /* In a template, callers should be building syntactic
5340 representations of casts, not using this machinery. */
5341 gcc_assert (!processing_template_decl);
5343 /* Assume the conversion is invalid. */
5347 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5350 error ("invalid use of const_cast with type %qT, "
5351 "which is not a pointer, "
5352 "reference, nor a pointer-to-data-member type", dst_type);
5353 return error_mark_node;
5356 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5359 error ("invalid use of const_cast with type %qT, which is a pointer "
5360 "or reference to a function type", dst_type);
5361 return error_mark_node;
5364 /* Save casted types in the function's used types hash table. */
5365 used_types_insert (dst_type);
5367 src_type = TREE_TYPE (expr);
5368 /* Expressions do not really have reference types. */
5369 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5370 src_type = TREE_TYPE (src_type);
5372 /* [expr.const.cast]
5374 An lvalue of type T1 can be explicitly converted to an lvalue of
5375 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5376 types) if a pointer to T1 can be explicitly converted to the type
5377 pointer to T2 using a const_cast. */
5378 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5380 reference_type = dst_type;
5381 if (! real_lvalue_p (expr))
5384 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5385 src_type, dst_type);
5386 return error_mark_node;
5388 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5389 src_type = build_pointer_type (src_type);
5393 reference_type = NULL_TREE;
5394 /* If the destination type is not a reference type, the
5395 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5396 conversions are performed. */
5397 src_type = type_decays_to (src_type);
5398 if (src_type == error_mark_node)
5399 return error_mark_node;
5402 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5403 && comp_ptr_ttypes_const (dst_type, src_type))
5408 /* This cast is actually a C-style cast. Issue a warning if
5409 the user is making a potentially unsafe cast. */
5411 check_for_casting_away_constness (src_type, dst_type,
5417 expr = build_unary_op (ADDR_EXPR, expr, 0);
5418 expr = build_nop (reference_type, expr);
5419 return convert_from_reference (expr);
5423 expr = decay_conversion (expr);
5424 /* build_c_cast puts on a NOP_EXPR to make the result not an
5425 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5426 non-lvalue context. */
5427 if (TREE_CODE (expr) == NOP_EXPR
5428 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5429 expr = TREE_OPERAND (expr, 0);
5430 return build_nop (dst_type, expr);
5435 error ("invalid const_cast from type %qT to type %qT",
5436 src_type, dst_type);
5437 return error_mark_node;
5441 build_const_cast (tree type, tree expr)
5443 if (type == error_mark_node || error_operand_p (expr))
5444 return error_mark_node;
5446 if (processing_template_decl)
5448 tree t = build_min (CONST_CAST_EXPR, type, expr);
5450 if (!TREE_SIDE_EFFECTS (t)
5451 && type_dependent_expression_p (expr))
5452 /* There might turn out to be side effects inside expr. */
5453 TREE_SIDE_EFFECTS (t) = 1;
5454 return convert_from_reference (t);
5457 return build_const_cast_1 (type, expr, /*complain=*/true,
5461 /* Build an expression representing an explicit C-style cast to type
5462 TYPE of expression EXPR. */
5465 build_c_cast (tree type, tree expr)
5471 if (type == error_mark_node || error_operand_p (expr))
5472 return error_mark_node;
5474 if (processing_template_decl)
5476 tree t = build_min (CAST_EXPR, type,
5477 tree_cons (NULL_TREE, value, NULL_TREE));
5478 /* We don't know if it will or will not have side effects. */
5479 TREE_SIDE_EFFECTS (t) = 1;
5480 return convert_from_reference (t);
5483 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5484 'Class') should always be retained, because this information aids
5485 in method lookup. */
5486 if (objc_is_object_ptr (type)
5487 && objc_is_object_ptr (TREE_TYPE (expr)))
5488 return build_nop (type, expr);
5490 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5491 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5492 if (TREE_CODE (type) != REFERENCE_TYPE
5493 && TREE_CODE (value) == NOP_EXPR
5494 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5495 value = TREE_OPERAND (value, 0);
5497 if (TREE_CODE (type) == ARRAY_TYPE)
5499 /* Allow casting from T1* to T2[] because Cfront allows it.
5500 NIHCL uses it. It is not valid ISO C++ however. */
5501 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5503 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5504 type = build_pointer_type (TREE_TYPE (type));
5508 error ("ISO C++ forbids casting to an array type %qT", type);
5509 return error_mark_node;
5513 if (TREE_CODE (type) == FUNCTION_TYPE
5514 || TREE_CODE (type) == METHOD_TYPE)
5516 error ("invalid cast to function type %qT", type);
5517 return error_mark_node;
5520 /* A C-style cast can be a const_cast. */
5521 result = build_const_cast_1 (type, value, /*complain=*/false,
5526 /* Or a static cast. */
5527 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5529 /* Or a reinterpret_cast. */
5531 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5533 /* The static_cast or reinterpret_cast may be followed by a
5536 /* A valid cast may result in errors if, for example, a
5537 conversion to am ambiguous base class is required. */
5538 && !error_operand_p (result))
5542 /* Non-class rvalues always have cv-unqualified type. */
5543 if (!CLASS_TYPE_P (type))
5544 type = TYPE_MAIN_VARIANT (type);
5545 result_type = TREE_TYPE (result);
5546 if (!CLASS_TYPE_P (result_type))
5547 result_type = TYPE_MAIN_VARIANT (result_type);
5548 /* If the type of RESULT does not match TYPE, perform a
5549 const_cast to make it match. If the static_cast or
5550 reinterpret_cast succeeded, we will differ by at most
5551 cv-qualification, so the follow-on const_cast is guaranteed
5553 if (!same_type_p (non_reference (type), non_reference (result_type)))
5555 result = build_const_cast_1 (type, result, false, &valid_p);
5556 gcc_assert (valid_p);
5561 return error_mark_node;
5564 /* Build an assignment expression of lvalue LHS from value RHS.
5565 MODIFYCODE is the code for a binary operator that we use
5566 to combine the old value of LHS with RHS to get the new value.
5567 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5569 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5572 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5576 tree lhstype = TREE_TYPE (lhs);
5577 tree olhstype = lhstype;
5578 tree olhs = NULL_TREE;
5579 bool plain_assign = (modifycode == NOP_EXPR);
5581 /* Avoid duplicate error messages from operands that had errors. */
5582 if (error_operand_p (lhs) || error_operand_p (rhs))
5583 return error_mark_node;
5585 /* Handle control structure constructs used as "lvalues". */
5586 switch (TREE_CODE (lhs))
5588 /* Handle --foo = 5; as these are valid constructs in C++. */
5589 case PREDECREMENT_EXPR:
5590 case PREINCREMENT_EXPR:
5591 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5592 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5593 stabilize_reference (TREE_OPERAND (lhs, 0)),
5594 TREE_OPERAND (lhs, 1));
5595 return build2 (COMPOUND_EXPR, lhstype,
5597 build_modify_expr (TREE_OPERAND (lhs, 0),
5600 /* Handle (a, b) used as an "lvalue". */
5602 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5604 if (newrhs == error_mark_node)
5605 return error_mark_node;
5606 return build2 (COMPOUND_EXPR, lhstype,
5607 TREE_OPERAND (lhs, 0), newrhs);
5610 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5611 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5612 stabilize_reference (TREE_OPERAND (lhs, 0)),
5613 TREE_OPERAND (lhs, 1));
5614 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5615 if (newrhs == error_mark_node)
5616 return error_mark_node;
5617 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5621 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5622 when neither operand has side-effects. */
5623 if (!lvalue_or_else (lhs, lv_assign))
5624 return error_mark_node;
5626 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5627 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5629 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5630 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5632 TREE_OPERAND (lhs, 0),
5633 TREE_OPERAND (lhs, 1)),
5634 TREE_OPERAND (lhs, 0),
5635 TREE_OPERAND (lhs, 1));
5638 /* Handle (a ? b : c) used as an "lvalue". */
5641 /* Produce (a ? (b = rhs) : (c = rhs))
5642 except that the RHS goes through a save-expr
5643 so the code to compute it is only emitted once. */
5645 tree preeval = NULL_TREE;
5647 rhs = stabilize_expr (rhs, &preeval);
5649 /* Check this here to avoid odd errors when trying to convert
5650 a throw to the type of the COND_EXPR. */
5651 if (!lvalue_or_else (lhs, lv_assign))
5652 return error_mark_node;
5654 cond = build_conditional_expr
5655 (TREE_OPERAND (lhs, 0),
5656 build_modify_expr (TREE_OPERAND (lhs, 1),
5658 build_modify_expr (TREE_OPERAND (lhs, 2),
5661 if (cond == error_mark_node)
5663 /* Make sure the code to compute the rhs comes out
5664 before the split. */
5666 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5674 if (modifycode == INIT_EXPR)
5676 if (TREE_CODE (rhs) == CONSTRUCTOR)
5678 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5679 /* Call convert to generate an error; see PR 11063. */
5680 rhs = convert (lhstype, rhs);
5681 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5682 TREE_SIDE_EFFECTS (result) = 1;
5685 else if (! IS_AGGR_TYPE (lhstype))
5686 /* Do the default thing. */;
5689 result = build_special_member_call (lhs, complete_ctor_identifier,
5690 build_tree_list (NULL_TREE, rhs),
5691 lhstype, LOOKUP_NORMAL);
5692 if (result == NULL_TREE)
5693 return error_mark_node;
5699 lhs = require_complete_type (lhs);
5700 if (lhs == error_mark_node)
5701 return error_mark_node;
5703 if (modifycode == NOP_EXPR)
5705 /* `operator=' is not an inheritable operator. */
5706 if (! IS_AGGR_TYPE (lhstype))
5707 /* Do the default thing. */;
5710 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5711 lhs, rhs, make_node (NOP_EXPR),
5712 /*overloaded_p=*/NULL);
5713 if (result == NULL_TREE)
5714 return error_mark_node;
5721 /* A binary op has been requested. Combine the old LHS
5722 value with the RHS producing the value we should actually
5723 store into the LHS. */
5725 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5726 lhs = stabilize_reference (lhs);
5727 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5728 if (newrhs == error_mark_node)
5730 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5731 TREE_TYPE (lhs), TREE_TYPE (rhs));
5732 return error_mark_node;
5735 /* Now it looks like a plain assignment. */
5736 modifycode = NOP_EXPR;
5738 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5739 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5742 /* The left-hand side must be an lvalue. */
5743 if (!lvalue_or_else (lhs, lv_assign))
5744 return error_mark_node;
5746 /* Warn about modifying something that is `const'. Don't warn if
5747 this is initialization. */
5748 if (modifycode != INIT_EXPR
5749 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5750 /* Functions are not modifiable, even though they are
5752 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5753 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5754 /* If it's an aggregate and any field is const, then it is
5755 effectively const. */
5756 || (CLASS_TYPE_P (lhstype)
5757 && C_TYPE_FIELDS_READONLY (lhstype))))
5758 readonly_error (lhs, "assignment", 0);
5760 /* If storing into a structure or union member, it has probably been
5761 given type `int'. Compute the type that would go with the actual
5762 amount of storage the member occupies. */
5764 if (TREE_CODE (lhs) == COMPONENT_REF
5765 && (TREE_CODE (lhstype) == INTEGER_TYPE
5766 || TREE_CODE (lhstype) == REAL_TYPE
5767 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5769 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5771 /* If storing in a field that is in actuality a short or narrower
5772 than one, we must store in the field in its actual type. */
5774 if (lhstype != TREE_TYPE (lhs))
5776 /* Avoid warnings converting integral types back into enums for
5778 if (TREE_CODE (lhstype) == INTEGER_TYPE
5779 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5781 if (TREE_SIDE_EFFECTS (lhs))
5782 lhs = stabilize_reference (lhs);
5785 lhs = copy_node (lhs);
5786 TREE_TYPE (lhs) = lhstype;
5790 /* Convert new value to destination type. */
5792 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5796 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5797 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5799 error ("incompatible types in assignment of %qT to %qT",
5800 TREE_TYPE (rhs), lhstype);
5801 return error_mark_node;
5804 /* Allow array assignment in compiler-generated code. */
5805 if (! DECL_ARTIFICIAL (current_function_decl))
5807 /* This routine is used for both initialization and assignment.
5808 Make sure the diagnostic message differentiates the context. */
5809 if (modifycode == INIT_EXPR)
5810 error ("array used as initializer");
5812 error ("invalid array assignment");
5813 return error_mark_node;
5816 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5817 ? 1 + (modifycode != INIT_EXPR): 0;
5818 return build_vec_init (lhs, NULL_TREE, newrhs,
5819 /*explicit_default_init_p=*/false,
5823 if (modifycode == INIT_EXPR)
5824 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5825 "initialization", NULL_TREE, 0);
5828 /* Avoid warnings on enum bit fields. */
5829 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5830 && TREE_CODE (lhstype) == INTEGER_TYPE)
5832 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5834 newrhs = convert_force (lhstype, newrhs, 0);
5837 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5839 if (TREE_CODE (newrhs) == CALL_EXPR
5840 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5841 newrhs = build_cplus_new (lhstype, newrhs);
5843 /* Can't initialize directly from a TARGET_EXPR, since that would
5844 cause the lhs to be constructed twice, and possibly result in
5845 accidental self-initialization. So we force the TARGET_EXPR to be
5846 expanded without a target. */
5847 if (TREE_CODE (newrhs) == TARGET_EXPR)
5848 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5849 TREE_OPERAND (newrhs, 0));
5852 if (newrhs == error_mark_node)
5853 return error_mark_node;
5855 if (c_dialect_objc () && flag_objc_gc)
5857 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5863 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5864 lhstype, lhs, newrhs);
5866 TREE_SIDE_EFFECTS (result) = 1;
5868 TREE_NO_WARNING (result) = 1;
5870 /* If we got the LHS in a different type for storing in,
5871 convert the result back to the nominal type of LHS
5872 so that the value we return always has the same type
5873 as the LHS argument. */
5875 if (olhstype == TREE_TYPE (result))
5879 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5880 TREE_NO_WARNING (result) = 1;
5883 return convert_for_assignment (olhstype, result, "assignment",
5888 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5890 if (processing_template_decl)
5891 return build_min_nt (MODOP_EXPR, lhs,
5892 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5894 if (modifycode != NOP_EXPR)
5896 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5897 make_node (modifycode),
5898 /*overloaded_p=*/NULL);
5901 TREE_NO_WARNING (rval) = 1;
5905 return build_modify_expr (lhs, modifycode, rhs);
5909 /* Get difference in deltas for different pointer to member function
5910 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5911 the conversion is invalid, the constant is zero. If
5912 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5913 If C_CAST_P is true this conversion is taking place as part of a
5916 Note that the naming of FROM and TO is kind of backwards; the return
5917 value is what we add to a TO in order to get a FROM. They are named
5918 this way because we call this function to find out how to convert from
5919 a pointer to member of FROM to a pointer to member of TO. */
5922 get_delta_difference (tree from, tree to,
5923 bool allow_inverse_p,
5930 /* Assume no conversion is required. */
5931 result = integer_zero_node;
5932 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5933 if (kind == bk_inaccessible || kind == bk_ambig)
5934 error (" in pointer to member function conversion");
5937 if (kind != bk_via_virtual)
5938 result = BINFO_OFFSET (binfo);
5941 tree virt_binfo = binfo_from_vbase (binfo);
5943 /* This is a reinterpret cast, we choose to do nothing. */
5944 if (allow_inverse_p)
5945 warning (0, "pointer to member cast via virtual base %qT",
5946 BINFO_TYPE (virt_binfo));
5948 error ("pointer to member conversion via virtual base %qT",
5949 BINFO_TYPE (virt_binfo));
5952 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5953 /* Pointer to member of incomplete class is permitted*/;
5954 else if (!allow_inverse_p)
5956 error_not_base_type (from, to);
5957 error (" in pointer to member conversion");
5961 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5964 if (kind != bk_via_virtual)
5965 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5968 /* This is a reinterpret cast, we choose to do nothing. */
5969 tree virt_binfo = binfo_from_vbase (binfo);
5971 warning (0, "pointer to member cast via virtual base %qT",
5972 BINFO_TYPE (virt_binfo));
5977 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5981 /* Return a constructor for the pointer-to-member-function TYPE using
5982 the other components as specified. */
5985 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5990 VEC(constructor_elt, gc) *v;
5992 /* Pull the FIELD_DECLs out of the type. */
5993 pfn_field = TYPE_FIELDS (type);
5994 delta_field = TREE_CHAIN (pfn_field);
5996 /* Make sure DELTA has the type we want. */
5997 delta = convert_and_check (delta_type_node, delta);
5999 /* Finish creating the initializer. */
6000 v = VEC_alloc(constructor_elt, gc, 2);
6001 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6002 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6003 u = build_constructor (type, v);
6004 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6005 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6006 TREE_STATIC (u) = (TREE_CONSTANT (u)
6007 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6009 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6014 /* Build a constructor for a pointer to member function. It can be
6015 used to initialize global variables, local variable, or used
6016 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6019 If FORCE is nonzero, then force this conversion, even if
6020 we would rather not do it. Usually set when using an explicit
6021 cast. A C-style cast is being processed iff C_CAST_P is true.
6023 Return error_mark_node, if something goes wrong. */
6026 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6032 if (error_operand_p (pfn))
6033 return error_mark_node;
6035 pfn_type = TREE_TYPE (pfn);
6036 to_type = build_ptrmemfunc_type (type);
6038 /* Handle multiple conversions of pointer to member functions. */
6039 if (TYPE_PTRMEMFUNC_P (pfn_type))
6041 tree delta = NULL_TREE;
6042 tree npfn = NULL_TREE;
6046 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6047 error ("invalid conversion to type %qT from type %qT",
6050 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6051 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6055 /* We don't have to do any conversion to convert a
6056 pointer-to-member to its own type. But, we don't want to
6057 just return a PTRMEM_CST if there's an explicit cast; that
6058 cast should make the expression an invalid template argument. */
6059 if (TREE_CODE (pfn) != PTRMEM_CST)
6061 if (same_type_p (to_type, pfn_type))
6063 else if (integer_zerop (n))
6064 return build_reinterpret_cast (to_type, pfn);
6067 if (TREE_SIDE_EFFECTS (pfn))
6068 pfn = save_expr (pfn);
6070 /* Obtain the function pointer and the current DELTA. */
6071 if (TREE_CODE (pfn) == PTRMEM_CST)
6072 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6075 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6076 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6079 /* Just adjust the DELTA field. */
6080 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6081 (TREE_TYPE (delta), ptrdiff_type_node));
6082 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6083 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6084 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6085 return build_ptrmemfunc1 (to_type, delta, npfn);
6088 /* Handle null pointer to member function conversions. */
6089 if (integer_zerop (pfn))
6091 pfn = build_c_cast (type, integer_zero_node);
6092 return build_ptrmemfunc1 (to_type,
6097 if (type_unknown_p (pfn))
6098 return instantiate_type (type, pfn, tf_warning_or_error);
6100 fn = TREE_OPERAND (pfn, 0);
6101 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6102 /* In a template, we will have preserved the
6104 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6105 return make_ptrmem_cst (to_type, fn);
6108 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6111 ??? There is no consistency as to the types returned for the above
6112 values. Some code acts as if it were a sizetype and some as if it were
6113 integer_type_node. */
6116 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6118 tree type = TREE_TYPE (cst);
6119 tree fn = PTRMEM_CST_MEMBER (cst);
6120 tree ptr_class, fn_class;
6122 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6124 /* The class that the function belongs to. */
6125 fn_class = DECL_CONTEXT (fn);
6127 /* The class that we're creating a pointer to member of. */
6128 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6130 /* First, calculate the adjustment to the function's class. */
6131 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6134 if (!DECL_VIRTUAL_P (fn))
6135 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6138 /* If we're dealing with a virtual function, we have to adjust 'this'
6139 again, to point to the base which provides the vtable entry for
6140 fn; the call will do the opposite adjustment. */
6141 tree orig_class = DECL_CONTEXT (fn);
6142 tree binfo = binfo_or_else (orig_class, fn_class);
6143 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6144 *delta, BINFO_OFFSET (binfo));
6145 *delta = fold_if_not_in_template (*delta);
6147 /* We set PFN to the vtable offset at which the function can be
6148 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6149 case delta is shifted left, and then incremented). */
6150 *pfn = DECL_VINDEX (fn);
6151 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6152 TYPE_SIZE_UNIT (vtable_entry_type));
6153 *pfn = fold_if_not_in_template (*pfn);
6155 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6157 case ptrmemfunc_vbit_in_pfn:
6158 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6160 *pfn = fold_if_not_in_template (*pfn);
6163 case ptrmemfunc_vbit_in_delta:
6164 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6165 *delta, integer_one_node);
6166 *delta = fold_if_not_in_template (*delta);
6167 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6168 *delta, integer_one_node);
6169 *delta = fold_if_not_in_template (*delta);
6176 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6177 *pfn = fold_if_not_in_template (*pfn);
6181 /* Return an expression for PFN from the pointer-to-member function
6185 pfn_from_ptrmemfunc (tree t)
6187 if (TREE_CODE (t) == PTRMEM_CST)
6192 expand_ptrmemfunc_cst (t, &delta, &pfn);
6197 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6200 /* Convert value RHS to type TYPE as preparation for an assignment to
6201 an lvalue of type TYPE. ERRTYPE is a string to use in error
6202 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6203 are doing the conversion in order to pass the PARMNUMth argument of
6207 convert_for_assignment (tree type, tree rhs,
6208 const char *errtype, tree fndecl, int parmnum)
6211 enum tree_code coder;
6213 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6214 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6215 rhs = TREE_OPERAND (rhs, 0);
6217 rhstype = TREE_TYPE (rhs);
6218 coder = TREE_CODE (rhstype);
6220 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6221 && vector_types_convertible_p (type, rhstype))
6222 return convert (type, rhs);
6224 if (rhs == error_mark_node || rhstype == error_mark_node)
6225 return error_mark_node;
6226 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6227 return error_mark_node;
6229 /* The RHS of an assignment cannot have void type. */
6230 if (coder == VOID_TYPE)
6232 error ("void value not ignored as it ought to be");
6233 return error_mark_node;
6236 /* Simplify the RHS if possible. */
6237 if (TREE_CODE (rhs) == CONST_DECL)
6238 rhs = DECL_INITIAL (rhs);
6240 if (c_dialect_objc ())
6243 tree rname = fndecl;
6245 if (!strcmp (errtype, "assignment"))
6247 else if (!strcmp (errtype, "initialization"))
6251 tree selector = objc_message_selector ();
6255 if (selector && parmno > 1)
6262 if (objc_compare_types (type, rhstype, parmno, rname))
6263 return convert (type, rhs);
6268 The expression is implicitly converted (clause _conv_) to the
6269 cv-unqualified type of the left operand.
6271 We allow bad conversions here because by the time we get to this point
6272 we are committed to doing the conversion. If we end up doing a bad
6273 conversion, convert_like will complain. */
6274 if (!can_convert_arg_bad (type, rhstype, rhs))
6276 /* When -Wno-pmf-conversions is use, we just silently allow
6277 conversions from pointers-to-members to plain pointers. If
6278 the conversion doesn't work, cp_convert will complain. */
6280 && TYPE_PTR_P (type)
6281 && TYPE_PTRMEMFUNC_P (rhstype))
6282 rhs = cp_convert (strip_top_quals (type), rhs);
6285 /* If the right-hand side has unknown type, then it is an
6286 overloaded function. Call instantiate_type to get error
6288 if (rhstype == unknown_type_node)
6289 instantiate_type (type, rhs, tf_warning_or_error);
6291 error ("cannot convert %qT to %qT for argument %qP to %qD",
6292 rhstype, type, parmnum, fndecl);
6294 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6295 return error_mark_node;
6298 if (warn_missing_format_attribute)
6300 const enum tree_code codel = TREE_CODE (type);
6301 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6303 && check_missing_format_attribute (type, rhstype))
6304 warning (OPT_Wmissing_format_attribute,
6305 "%s might be a candidate for a format attribute",
6309 return perform_implicit_conversion (strip_top_quals (type), rhs);
6312 /* Convert RHS to be of type TYPE.
6313 If EXP is nonzero, it is the target of the initialization.
6314 ERRTYPE is a string to use in error messages.
6316 Two major differences between the behavior of
6317 `convert_for_assignment' and `convert_for_initialization'
6318 are that references are bashed in the former, while
6319 copied in the latter, and aggregates are assigned in
6320 the former (operator=) while initialized in the
6323 If using constructor make sure no conversion operator exists, if one does
6324 exist, an ambiguity exists.
6326 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6329 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6330 const char *errtype, tree fndecl, int parmnum)
6332 enum tree_code codel = TREE_CODE (type);
6334 enum tree_code coder;
6336 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6337 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6338 if (TREE_CODE (rhs) == NOP_EXPR
6339 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6340 && codel != REFERENCE_TYPE)
6341 rhs = TREE_OPERAND (rhs, 0);
6343 if (type == error_mark_node
6344 || rhs == error_mark_node
6345 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6346 return error_mark_node;
6348 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6349 && TREE_CODE (type) != ARRAY_TYPE
6350 && (TREE_CODE (type) != REFERENCE_TYPE
6351 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6352 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6353 && (TREE_CODE (type) != REFERENCE_TYPE
6354 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6355 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6356 rhs = decay_conversion (rhs);
6358 rhstype = TREE_TYPE (rhs);
6359 coder = TREE_CODE (rhstype);
6361 if (coder == ERROR_MARK)
6362 return error_mark_node;
6364 /* We accept references to incomplete types, so we can
6365 return here before checking if RHS is of complete type. */
6367 if (codel == REFERENCE_TYPE)
6369 /* This should eventually happen in convert_arguments. */
6370 int savew = 0, savee = 0;
6373 savew = warningcount, savee = errorcount;
6374 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6378 if (warningcount > savew)
6379 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6380 else if (errorcount > savee)
6381 error ("in passing argument %P of %q+D", parmnum, fndecl);
6387 exp = require_complete_type (exp);
6388 if (exp == error_mark_node)
6389 return error_mark_node;
6391 rhstype = non_reference (rhstype);
6393 type = complete_type (type);
6395 if (IS_AGGR_TYPE (type))
6396 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6398 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6401 /* If RETVAL is the address of, or a reference to, a local variable or
6402 temporary give an appropriate warning. */
6405 maybe_warn_about_returning_address_of_local (tree retval)
6407 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6408 tree whats_returned = retval;
6412 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6413 whats_returned = TREE_OPERAND (whats_returned, 1);
6414 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6415 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6416 || TREE_CODE (whats_returned) == NOP_EXPR)
6417 whats_returned = TREE_OPERAND (whats_returned, 0);
6422 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6424 whats_returned = TREE_OPERAND (whats_returned, 0);
6426 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6428 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6429 || TREE_CODE (whats_returned) == TARGET_EXPR)
6431 warning (0, "returning reference to temporary");
6434 if (TREE_CODE (whats_returned) == VAR_DECL
6435 && DECL_NAME (whats_returned)
6436 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6438 warning (0, "reference to non-lvalue returned");
6443 while (TREE_CODE (whats_returned) == COMPONENT_REF
6444 || TREE_CODE (whats_returned) == ARRAY_REF)
6445 whats_returned = TREE_OPERAND (whats_returned, 0);
6447 if (DECL_P (whats_returned)
6448 && DECL_NAME (whats_returned)
6449 && DECL_FUNCTION_SCOPE_P (whats_returned)
6450 && !(TREE_STATIC (whats_returned)
6451 || TREE_PUBLIC (whats_returned)))
6453 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6454 warning (0, "reference to local variable %q+D returned",
6457 warning (0, "address of local variable %q+D returned",
6463 /* Check that returning RETVAL from the current function is valid.
6464 Return an expression explicitly showing all conversions required to
6465 change RETVAL into the function return type, and to assign it to
6466 the DECL_RESULT for the function. Set *NO_WARNING to true if
6467 code reaches end of non-void function warning shouldn't be issued
6468 on this RETURN_EXPR. */
6471 check_return_expr (tree retval, bool *no_warning)
6474 /* The type actually returned by the function, after any
6477 int fn_returns_value_p;
6479 *no_warning = false;
6481 /* A `volatile' function is one that isn't supposed to return, ever.
6482 (This is a G++ extension, used to get better code for functions
6483 that call the `volatile' function.) */
6484 if (TREE_THIS_VOLATILE (current_function_decl))
6485 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6487 /* Check for various simple errors. */
6488 if (DECL_DESTRUCTOR_P (current_function_decl))
6491 error ("returning a value from a destructor");
6494 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6496 if (in_function_try_handler)
6497 /* If a return statement appears in a handler of the
6498 function-try-block of a constructor, the program is ill-formed. */
6499 error ("cannot return from a handler of a function-try-block of a constructor");
6501 /* You can't return a value from a constructor. */
6502 error ("returning a value from a constructor");
6506 if (processing_template_decl)
6508 current_function_returns_value = 1;
6512 /* When no explicit return-value is given in a function with a named
6513 return value, the named return value is used. */
6514 result = DECL_RESULT (current_function_decl);
6515 valtype = TREE_TYPE (result);
6516 gcc_assert (valtype != NULL_TREE);
6517 fn_returns_value_p = !VOID_TYPE_P (valtype);
6518 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6521 /* Check for a return statement with no return value in a function
6522 that's supposed to return a value. */
6523 if (!retval && fn_returns_value_p)
6525 pedwarn ("return-statement with no value, in function returning %qT",
6527 /* Clear this, so finish_function won't say that we reach the
6528 end of a non-void function (which we don't, we gave a
6530 current_function_returns_null = 0;
6531 /* And signal caller that TREE_NO_WARNING should be set on the
6532 RETURN_EXPR to avoid control reaches end of non-void function
6533 warnings in tree-cfg.c. */
6536 /* Check for a return statement with a value in a function that
6537 isn't supposed to return a value. */
6538 else if (retval && !fn_returns_value_p)
6540 if (VOID_TYPE_P (TREE_TYPE (retval)))
6541 /* You can return a `void' value from a function of `void'
6542 type. In that case, we have to evaluate the expression for
6543 its side-effects. */
6544 finish_expr_stmt (retval);
6546 pedwarn ("return-statement with a value, in function "
6547 "returning 'void'");
6549 current_function_returns_null = 1;
6551 /* There's really no value to return, after all. */
6555 /* Remember that this function can sometimes return without a
6557 current_function_returns_null = 1;
6559 /* Remember that this function did return a value. */
6560 current_function_returns_value = 1;
6562 /* Check for erroneous operands -- but after giving ourselves a
6563 chance to provide an error about returning a value from a void
6565 if (error_operand_p (retval))
6567 current_function_return_value = error_mark_node;
6568 return error_mark_node;
6571 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6572 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6573 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6574 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6576 && null_ptr_cst_p (retval))
6577 warning (0, "%<operator new%> must not return NULL unless it is "
6578 "declared %<throw()%> (or -fcheck-new is in effect)");
6580 /* Effective C++ rule 15. See also start_function. */
6582 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6586 /* The function return type must be a reference to the current
6588 if (TREE_CODE (valtype) == REFERENCE_TYPE
6589 && same_type_ignoring_top_level_qualifiers_p
6590 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6592 /* Returning '*this' is obviously OK. */
6593 if (retval == current_class_ref)
6595 /* If we are calling a function whose return type is the same of
6596 the current class reference, it is ok. */
6597 else if (TREE_CODE (retval) == INDIRECT_REF
6598 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6603 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6606 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6608 [...] For a function with a class return type, if the expression
6609 in the return statement is the name of a local object, and the cv-
6610 unqualified type of the local object is the same as the function
6611 return type, an implementation is permitted to omit creating the tem-
6612 porary object to hold the function return value [...]
6614 So, if this is a value-returning function that always returns the same
6615 local variable, remember it.
6617 It might be nice to be more flexible, and choose the first suitable
6618 variable even if the function sometimes returns something else, but
6619 then we run the risk of clobbering the variable we chose if the other
6620 returned expression uses the chosen variable somehow. And people expect
6621 this restriction, anyway. (jason 2000-11-19)
6623 See finish_function and finalize_nrv for the rest of this optimization. */
6625 if (fn_returns_value_p && flag_elide_constructors)
6627 if (retval != NULL_TREE
6628 && (current_function_return_value == NULL_TREE
6629 || current_function_return_value == retval)
6630 && TREE_CODE (retval) == VAR_DECL
6631 && DECL_CONTEXT (retval) == current_function_decl
6632 && ! TREE_STATIC (retval)
6633 && (DECL_ALIGN (retval)
6634 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6635 && same_type_p ((TYPE_MAIN_VARIANT
6636 (TREE_TYPE (retval))),
6638 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6639 current_function_return_value = retval;
6641 current_function_return_value = error_mark_node;
6644 /* We don't need to do any conversions when there's nothing being
6649 /* Do any required conversions. */
6650 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6651 /* No conversions are required. */
6655 /* The type the function is declared to return. */
6656 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6658 /* The functype's return type will have been set to void, if it
6659 was an incomplete type. Just treat this as 'return;' */
6660 if (VOID_TYPE_P (functype))
6661 return error_mark_node;
6663 /* First convert the value to the function's return type, then
6664 to the type of return value's location to handle the
6665 case that functype is smaller than the valtype. */
6666 retval = convert_for_initialization
6667 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6668 "return", NULL_TREE, 0);
6669 retval = convert (valtype, retval);
6671 /* If the conversion failed, treat this just like `return;'. */
6672 if (retval == error_mark_node)
6674 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6675 else if (! current_function_returns_struct
6676 && TREE_CODE (retval) == TARGET_EXPR
6677 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6678 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6679 TREE_OPERAND (retval, 0));
6681 maybe_warn_about_returning_address_of_local (retval);
6684 /* Actually copy the value returned into the appropriate location. */
6685 if (retval && retval != result)
6686 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6692 /* Returns nonzero if the pointer-type FROM can be converted to the
6693 pointer-type TO via a qualification conversion. If CONSTP is -1,
6694 then we return nonzero if the pointers are similar, and the
6695 cv-qualification signature of FROM is a proper subset of that of TO.
6697 If CONSTP is positive, then all outer pointers have been
6701 comp_ptr_ttypes_real (tree to, tree from, int constp)
6703 bool to_more_cv_qualified = false;
6705 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6707 if (TREE_CODE (to) != TREE_CODE (from))
6710 if (TREE_CODE (from) == OFFSET_TYPE
6711 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6712 TYPE_OFFSET_BASETYPE (to)))
6715 /* Const and volatile mean something different for function types,
6716 so the usual checks are not appropriate. */
6717 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6719 /* In Objective-C++, some types may have been 'volatilized' by
6720 the compiler for EH; when comparing them here, the volatile
6721 qualification must be ignored. */
6722 bool objc_quals_match = objc_type_quals_match (to, from);
6724 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6727 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6731 to_more_cv_qualified = true;
6735 constp &= TYPE_READONLY (to);
6738 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6739 return ((constp >= 0 || to_more_cv_qualified)
6740 && same_type_ignoring_top_level_qualifiers_p (to, from));
6744 /* When comparing, say, char ** to char const **, this function takes
6745 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6746 types to this function. */
6749 comp_ptr_ttypes (tree to, tree from)
6751 return comp_ptr_ttypes_real (to, from, 1);
6754 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6755 type or inheritance-related types, regardless of cv-quals. */
6758 ptr_reasonably_similar (tree to, tree from)
6760 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6762 /* Any target type is similar enough to void. */
6763 if (TREE_CODE (to) == VOID_TYPE
6764 || TREE_CODE (from) == VOID_TYPE)
6767 if (TREE_CODE (to) != TREE_CODE (from))
6770 if (TREE_CODE (from) == OFFSET_TYPE
6771 && comptypes (TYPE_OFFSET_BASETYPE (to),
6772 TYPE_OFFSET_BASETYPE (from),
6773 COMPARE_BASE | COMPARE_DERIVED))
6776 if (TREE_CODE (to) == VECTOR_TYPE
6777 && vector_types_convertible_p (to, from))
6780 if (TREE_CODE (to) == INTEGER_TYPE
6781 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6784 if (TREE_CODE (to) == FUNCTION_TYPE)
6787 if (TREE_CODE (to) != POINTER_TYPE)
6789 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6790 COMPARE_BASE | COMPARE_DERIVED);
6794 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6795 pointer-to-member types) are the same, ignoring cv-qualification at
6799 comp_ptr_ttypes_const (tree to, tree from)
6801 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6803 if (TREE_CODE (to) != TREE_CODE (from))
6806 if (TREE_CODE (from) == OFFSET_TYPE
6807 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6808 TYPE_OFFSET_BASETYPE (to)))
6811 if (TREE_CODE (to) != POINTER_TYPE)
6812 return same_type_ignoring_top_level_qualifiers_p (to, from);
6816 /* Returns the type qualifiers for this type, including the qualifiers on the
6817 elements for an array type. */
6820 cp_type_quals (tree type)
6822 type = strip_array_types (type);
6823 if (type == error_mark_node)
6824 return TYPE_UNQUALIFIED;
6825 return TYPE_QUALS (type);
6828 /* Returns nonzero if the TYPE contains a mutable member. */
6831 cp_has_mutable_p (tree type)
6833 type = strip_array_types (type);
6835 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6838 /* Apply the TYPE_QUALS to the new DECL. */
6840 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6842 tree type = TREE_TYPE (decl);
6844 if (type == error_mark_node)
6847 if (TREE_CODE (type) == FUNCTION_TYPE
6848 && type_quals != TYPE_UNQUALIFIED)
6850 /* This was an error in C++98 (cv-qualifiers cannot be added to
6851 a function type), but DR 295 makes the code well-formed by
6852 dropping the extra qualifiers. */
6855 tree bad_type = build_qualified_type (type, type_quals);
6856 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6860 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6864 /* Avoid setting TREE_READONLY incorrectly. */
6865 if (/* If the object has a constructor, the constructor may modify
6867 TYPE_NEEDS_CONSTRUCTING (type)
6868 /* If the type isn't complete, we don't know yet if it will need
6870 || !COMPLETE_TYPE_P (type)
6871 /* If the type has a mutable component, that component might be
6873 || TYPE_HAS_MUTABLE_P (type))
6874 type_quals &= ~TYPE_QUAL_CONST;
6876 c_apply_type_quals_to_decl (type_quals, decl);
6879 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6880 exemplar types such that casting T1 to T2 is casting away constness
6881 if and only if there is no implicit conversion from T1 to T2. */
6884 casts_away_constness_r (tree *t1, tree *t2)
6889 /* [expr.const.cast]
6891 For multi-level pointer to members and multi-level mixed pointers
6892 and pointers to members (conv.qual), the "member" aspect of a
6893 pointer to member level is ignored when determining if a const
6894 cv-qualifier has been cast away. */
6895 /* [expr.const.cast]
6897 For two pointer types:
6899 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6900 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6903 casting from X1 to X2 casts away constness if, for a non-pointer
6904 type T there does not exist an implicit conversion (clause
6907 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6911 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6912 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6913 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6915 *t1 = cp_build_qualified_type (void_type_node,
6916 cp_type_quals (*t1));
6917 *t2 = cp_build_qualified_type (void_type_node,
6918 cp_type_quals (*t2));
6922 quals1 = cp_type_quals (*t1);
6923 quals2 = cp_type_quals (*t2);
6925 if (TYPE_PTRMEM_P (*t1))
6926 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6928 *t1 = TREE_TYPE (*t1);
6929 if (TYPE_PTRMEM_P (*t2))
6930 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6932 *t2 = TREE_TYPE (*t2);
6934 casts_away_constness_r (t1, t2);
6935 *t1 = build_pointer_type (*t1);
6936 *t2 = build_pointer_type (*t2);
6937 *t1 = cp_build_qualified_type (*t1, quals1);
6938 *t2 = cp_build_qualified_type (*t2, quals2);
6941 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6945 casts_away_constness (tree t1, tree t2)
6947 if (TREE_CODE (t2) == REFERENCE_TYPE)
6949 /* [expr.const.cast]
6951 Casting from an lvalue of type T1 to an lvalue of type T2
6952 using a reference cast casts away constness if a cast from an
6953 rvalue of type "pointer to T1" to the type "pointer to T2"
6954 casts away constness. */
6955 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6956 return casts_away_constness (build_pointer_type (t1),
6957 build_pointer_type (TREE_TYPE (t2)));
6960 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6961 /* [expr.const.cast]
6963 Casting from an rvalue of type "pointer to data member of X
6964 of type T1" to the type "pointer to data member of Y of type
6965 T2" casts away constness if a cast from an rvalue of type
6966 "pointer to T1" to the type "pointer to T2" casts away
6968 return casts_away_constness
6969 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6970 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6972 /* Casting away constness is only something that makes sense for
6973 pointer or reference types. */
6974 if (TREE_CODE (t1) != POINTER_TYPE
6975 || TREE_CODE (t2) != POINTER_TYPE)
6978 /* Top-level qualifiers don't matter. */
6979 t1 = TYPE_MAIN_VARIANT (t1);
6980 t2 = TYPE_MAIN_VARIANT (t2);
6981 casts_away_constness_r (&t1, &t2);
6982 if (!can_convert (t2, t1))
6988 /* If T is a REFERENCE_TYPE return the type to which T refers.
6989 Otherwise, return T itself. */
6992 non_reference (tree t)
6994 if (TREE_CODE (t) == REFERENCE_TYPE)
7000 /* Return nonzero if REF is an lvalue valid for this language;
7001 otherwise, print an error message and return zero. USE says
7002 how the lvalue is being used and so selects the error message. */
7005 lvalue_or_else (tree ref, enum lvalue_use use)
7007 int win = lvalue_p (ref);