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 (t1) == 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 /* The following code is incorrect if either operand side-effects. */
1652 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (t, 0))
1653 && !TREE_SIDE_EFFECTS (TREE_OPERAND (t, 1)));
1655 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1656 ? LE_EXPR : GE_EXPR),
1657 TREE_OPERAND (t, 0),
1658 TREE_OPERAND (t, 1),
1659 /*overloaded_p=*/NULL),
1660 build_unary_op (code, TREE_OPERAND (t, 0), 0),
1661 build_unary_op (code, TREE_OPERAND (t, 1), 0));
1665 build_conditional_expr (TREE_OPERAND (t, 0),
1666 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1667 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1670 /* Given the TYPE of an anonymous union field inside T, return the
1671 FIELD_DECL for the field. If not found return NULL_TREE. Because
1672 anonymous unions can nest, we must also search all anonymous unions
1673 that are directly reachable. */
1676 lookup_anon_field (tree t, tree type)
1680 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1682 if (TREE_STATIC (field))
1684 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1687 /* If we find it directly, return the field. */
1688 if (DECL_NAME (field) == NULL_TREE
1689 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1694 /* Otherwise, it could be nested, search harder. */
1695 if (DECL_NAME (field) == NULL_TREE
1696 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1698 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1706 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1707 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1708 non-NULL, it indicates the path to the base used to name MEMBER.
1709 If PRESERVE_REFERENCE is true, the expression returned will have
1710 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1711 returned will have the type referred to by the reference.
1713 This function does not perform access control; that is either done
1714 earlier by the parser when the name of MEMBER is resolved to MEMBER
1715 itself, or later when overload resolution selects one of the
1716 functions indicated by MEMBER. */
1719 build_class_member_access_expr (tree object, tree member,
1720 tree access_path, bool preserve_reference)
1724 tree result = NULL_TREE;
1726 if (error_operand_p (object) || error_operand_p (member))
1727 return error_mark_node;
1729 gcc_assert (DECL_P (member) || BASELINK_P (member));
1733 The type of the first expression shall be "class object" (of a
1735 object_type = TREE_TYPE (object);
1736 if (!currently_open_class (object_type)
1737 && !complete_type_or_else (object_type, object))
1738 return error_mark_node;
1739 if (!CLASS_TYPE_P (object_type))
1741 error ("request for member %qD in %qE, which is of non-class type %qT",
1742 member, object, object_type);
1743 return error_mark_node;
1746 /* The standard does not seem to actually say that MEMBER must be a
1747 member of OBJECT_TYPE. However, that is clearly what is
1749 if (DECL_P (member))
1751 member_scope = DECL_CLASS_CONTEXT (member);
1753 if (TREE_DEPRECATED (member))
1754 warn_deprecated_use (member);
1757 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1758 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1759 presently be the anonymous union. Go outwards until we find a
1760 type related to OBJECT_TYPE. */
1761 while (ANON_AGGR_TYPE_P (member_scope)
1762 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1764 member_scope = TYPE_CONTEXT (member_scope);
1765 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1767 if (TREE_CODE (member) == FIELD_DECL)
1768 error ("invalid use of nonstatic data member %qE", member);
1770 error ("%qD is not a member of %qT", member, object_type);
1771 return error_mark_node;
1774 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1775 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1776 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1778 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1780 object = build_indirect_ref (temp, NULL);
1783 /* In [expr.ref], there is an explicit list of the valid choices for
1784 MEMBER. We check for each of those cases here. */
1785 if (TREE_CODE (member) == VAR_DECL)
1787 /* A static data member. */
1789 /* If OBJECT has side-effects, they are supposed to occur. */
1790 if (TREE_SIDE_EFFECTS (object))
1791 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1793 else if (TREE_CODE (member) == FIELD_DECL)
1795 /* A non-static data member. */
1800 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1801 && integer_zerop (TREE_OPERAND (object, 0)));
1803 /* Convert OBJECT to the type of MEMBER. */
1804 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1805 TYPE_MAIN_VARIANT (member_scope)))
1810 binfo = lookup_base (access_path ? access_path : object_type,
1811 member_scope, ba_unique, &kind);
1812 if (binfo == error_mark_node)
1813 return error_mark_node;
1815 /* It is invalid to try to get to a virtual base of a
1816 NULL object. The most common cause is invalid use of
1818 if (null_object_p && kind == bk_via_virtual)
1820 error ("invalid access to non-static data member %qD of "
1823 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1824 return error_mark_node;
1827 /* Convert to the base. */
1828 object = build_base_path (PLUS_EXPR, object, binfo,
1830 /* If we found the base successfully then we should be able
1831 to convert to it successfully. */
1832 gcc_assert (object != error_mark_node);
1835 /* Complain about other invalid uses of offsetof, even though they will
1836 give the right answer. Note that we complain whether or not they
1837 actually used the offsetof macro, since there's no way to know at this
1838 point. So we just give a warning, instead of a pedwarn. */
1839 /* Do not produce this warning for base class field references, because
1840 we know for a fact that didn't come from offsetof. This does occur
1841 in various testsuite cases where a null object is passed where a
1842 vtable access is required. */
1843 if (null_object_p && warn_invalid_offsetof
1844 && CLASSTYPE_NON_POD_P (object_type)
1845 && !DECL_FIELD_IS_BASE (member)
1846 && !skip_evaluation)
1848 warning (0, "invalid access to non-static data member %qD of NULL object",
1850 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1853 /* If MEMBER is from an anonymous aggregate, we have converted
1854 OBJECT so that it refers to the class containing the
1855 anonymous union. Generate a reference to the anonymous union
1856 itself, and recur to find MEMBER. */
1857 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1858 /* When this code is called from build_field_call, the
1859 object already has the type of the anonymous union.
1860 That is because the COMPONENT_REF was already
1861 constructed, and was then disassembled before calling
1862 build_field_call. After the function-call code is
1863 cleaned up, this waste can be eliminated. */
1864 && (!same_type_ignoring_top_level_qualifiers_p
1865 (TREE_TYPE (object), DECL_CONTEXT (member))))
1867 tree anonymous_union;
1869 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1870 DECL_CONTEXT (member));
1871 object = build_class_member_access_expr (object,
1873 /*access_path=*/NULL_TREE,
1874 preserve_reference);
1877 /* Compute the type of the field, as described in [expr.ref]. */
1878 type_quals = TYPE_UNQUALIFIED;
1879 member_type = TREE_TYPE (member);
1880 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1882 type_quals = (cp_type_quals (member_type)
1883 | cp_type_quals (object_type));
1885 /* A field is const (volatile) if the enclosing object, or the
1886 field itself, is const (volatile). But, a mutable field is
1887 not const, even within a const object. */
1888 if (DECL_MUTABLE_P (member))
1889 type_quals &= ~TYPE_QUAL_CONST;
1890 member_type = cp_build_qualified_type (member_type, type_quals);
1893 result = build3 (COMPONENT_REF, member_type, object, member,
1895 result = fold_if_not_in_template (result);
1897 /* Mark the expression const or volatile, as appropriate. Even
1898 though we've dealt with the type above, we still have to mark the
1899 expression itself. */
1900 if (type_quals & TYPE_QUAL_CONST)
1901 TREE_READONLY (result) = 1;
1902 if (type_quals & TYPE_QUAL_VOLATILE)
1903 TREE_THIS_VOLATILE (result) = 1;
1905 else if (BASELINK_P (member))
1907 /* The member is a (possibly overloaded) member function. */
1911 /* If the MEMBER is exactly one static member function, then we
1912 know the type of the expression. Otherwise, we must wait
1913 until overload resolution has been performed. */
1914 functions = BASELINK_FUNCTIONS (member);
1915 if (TREE_CODE (functions) == FUNCTION_DECL
1916 && DECL_STATIC_FUNCTION_P (functions))
1917 type = TREE_TYPE (functions);
1919 type = unknown_type_node;
1920 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1921 base. That will happen when the function is called. */
1922 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1924 else if (TREE_CODE (member) == CONST_DECL)
1926 /* The member is an enumerator. */
1928 /* If OBJECT has side-effects, they are supposed to occur. */
1929 if (TREE_SIDE_EFFECTS (object))
1930 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1935 error ("invalid use of %qD", member);
1936 return error_mark_node;
1939 if (!preserve_reference)
1942 If E2 is declared to have type "reference to T", then ... the
1943 type of E1.E2 is T. */
1944 result = convert_from_reference (result);
1949 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1950 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
1953 lookup_destructor (tree object, tree scope, tree dtor_name)
1955 tree object_type = TREE_TYPE (object);
1956 tree dtor_type = TREE_OPERAND (dtor_name, 0);
1959 if (scope && !check_dtor_name (scope, dtor_type))
1961 error ("qualified type %qT does not match destructor name ~%qT",
1963 return error_mark_node;
1965 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
1967 error ("the type being destroyed is %qT, but the destructor refers to %qT",
1968 TYPE_MAIN_VARIANT (object_type), dtor_type);
1969 return error_mark_node;
1971 expr = lookup_member (dtor_type, complete_dtor_identifier,
1972 /*protect=*/1, /*want_type=*/false);
1973 expr = (adjust_result_of_qualified_name_lookup
1974 (expr, dtor_type, object_type));
1978 /* An expression of the form "A::template B" has been resolved to
1979 DECL. Issue a diagnostic if B is not a template or template
1983 check_template_keyword (tree decl)
1985 /* The standard says:
1989 If a name prefixed by the keyword template is not a member
1990 template, the program is ill-formed.
1992 DR 228 removed the restriction that the template be a member
1995 DR 96, if accepted would add the further restriction that explicit
1996 template arguments must be provided if the template keyword is
1997 used, but, as of 2005-10-16, that DR is still in "drafting". If
1998 this DR is accepted, then the semantic checks here can be
1999 simplified, as the entity named must in fact be a template
2000 specialization, rather than, as at present, a set of overloaded
2001 functions containing at least one template function. */
2002 if (TREE_CODE (decl) != TEMPLATE_DECL
2003 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2005 if (!is_overloaded_fn (decl))
2006 pedwarn ("%qD is not a template", decl);
2011 if (BASELINK_P (fns))
2012 fns = BASELINK_FUNCTIONS (fns);
2015 tree fn = OVL_CURRENT (fns);
2016 if (TREE_CODE (fn) == TEMPLATE_DECL
2017 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2019 if (TREE_CODE (fn) == FUNCTION_DECL
2020 && DECL_USE_TEMPLATE (fn)
2021 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2023 fns = OVL_NEXT (fns);
2026 pedwarn ("%qD is not a template", decl);
2031 /* This function is called by the parser to process a class member
2032 access expression of the form OBJECT.NAME. NAME is a node used by
2033 the parser to represent a name; it is not yet a DECL. It may,
2034 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2035 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2036 there is no reason to do the lookup twice, so the parser keeps the
2037 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2038 be a template via the use of the "A::template B" syntax. */
2041 finish_class_member_access_expr (tree object, tree name, bool template_p)
2046 tree access_path = NULL_TREE;
2047 tree orig_object = object;
2048 tree orig_name = name;
2050 if (object == error_mark_node || name == error_mark_node)
2051 return error_mark_node;
2053 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2054 if (!objc_is_public (object, name))
2055 return error_mark_node;
2057 object_type = TREE_TYPE (object);
2059 if (processing_template_decl)
2061 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2062 dependent_type_p (object_type)
2063 /* If NAME is just an IDENTIFIER_NODE, then the expression
2065 || TREE_CODE (object) == IDENTIFIER_NODE
2066 /* If NAME is "f<args>", where either 'f' or 'args' is
2067 dependent, then the expression is dependent. */
2068 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2069 && dependent_template_id_p (TREE_OPERAND (name, 0),
2070 TREE_OPERAND (name, 1)))
2071 /* If NAME is "T::X" where "T" is dependent, then the
2072 expression is dependent. */
2073 || (TREE_CODE (name) == SCOPE_REF
2074 && TYPE_P (TREE_OPERAND (name, 0))
2075 && dependent_type_p (TREE_OPERAND (name, 0))))
2076 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2077 object = build_non_dependent_expr (object);
2082 The type of the first expression shall be "class object" (of a
2084 if (!currently_open_class (object_type)
2085 && !complete_type_or_else (object_type, object))
2086 return error_mark_node;
2087 if (!CLASS_TYPE_P (object_type))
2089 error ("request for member %qD in %qE, which is of non-class type %qT",
2090 name, object, object_type);
2091 return error_mark_node;
2094 if (BASELINK_P (name))
2095 /* A member function that has already been looked up. */
2099 bool is_template_id = false;
2100 tree template_args = NULL_TREE;
2103 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2105 is_template_id = true;
2106 template_args = TREE_OPERAND (name, 1);
2107 name = TREE_OPERAND (name, 0);
2109 if (TREE_CODE (name) == OVERLOAD)
2110 name = DECL_NAME (get_first_fn (name));
2111 else if (DECL_P (name))
2112 name = DECL_NAME (name);
2115 if (TREE_CODE (name) == SCOPE_REF)
2117 /* A qualified name. The qualifying class or namespace `S'
2118 has already been looked up; it is either a TYPE or a
2120 scope = TREE_OPERAND (name, 0);
2121 name = TREE_OPERAND (name, 1);
2123 /* If SCOPE is a namespace, then the qualified name does not
2124 name a member of OBJECT_TYPE. */
2125 if (TREE_CODE (scope) == NAMESPACE_DECL)
2127 error ("%<%D::%D%> is not a member of %qT",
2128 scope, name, object_type);
2129 return error_mark_node;
2132 gcc_assert (CLASS_TYPE_P (scope));
2133 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2134 || TREE_CODE (name) == BIT_NOT_EXPR);
2136 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2137 access_path = lookup_base (object_type, scope, ba_check, NULL);
2138 if (access_path == error_mark_node)
2139 return error_mark_node;
2142 error ("%qT is not a base of %qT", scope, object_type);
2143 return error_mark_node;
2149 access_path = object_type;
2152 if (TREE_CODE (name) == BIT_NOT_EXPR)
2153 member = lookup_destructor (object, scope, name);
2156 /* Look up the member. */
2157 member = lookup_member (access_path, name, /*protect=*/1,
2158 /*want_type=*/false);
2159 if (member == NULL_TREE)
2161 error ("%qD has no member named %qE", object_type, name);
2162 return error_mark_node;
2164 if (member == error_mark_node)
2165 return error_mark_node;
2170 tree template = member;
2172 if (BASELINK_P (template))
2173 template = lookup_template_function (template, template_args);
2176 error ("%qD is not a member template function", name);
2177 return error_mark_node;
2182 if (TREE_DEPRECATED (member))
2183 warn_deprecated_use (member);
2186 check_template_keyword (member);
2188 expr = build_class_member_access_expr (object, member, access_path,
2189 /*preserve_reference=*/false);
2190 if (processing_template_decl && expr != error_mark_node)
2192 if (BASELINK_P (member))
2194 if (TREE_CODE (orig_name) == SCOPE_REF)
2195 BASELINK_QUALIFIED_P (member) = 1;
2198 return build_min_non_dep (COMPONENT_REF, expr,
2199 orig_object, orig_name,
2206 /* Return an expression for the MEMBER_NAME field in the internal
2207 representation of PTRMEM, a pointer-to-member function. (Each
2208 pointer-to-member function type gets its own RECORD_TYPE so it is
2209 more convenient to access the fields by name than by FIELD_DECL.)
2210 This routine converts the NAME to a FIELD_DECL and then creates the
2211 node for the complete expression. */
2214 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2220 /* This code is a stripped down version of
2221 build_class_member_access_expr. It does not work to use that
2222 routine directly because it expects the object to be of class
2224 ptrmem_type = TREE_TYPE (ptrmem);
2225 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2226 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2227 /*want_type=*/false);
2228 member_type = cp_build_qualified_type (TREE_TYPE (member),
2229 cp_type_quals (ptrmem_type));
2230 return fold_build3 (COMPONENT_REF, member_type,
2231 ptrmem, member, NULL_TREE);
2234 /* Given an expression PTR for a pointer, return an expression
2235 for the value pointed to.
2236 ERRORSTRING is the name of the operator to appear in error messages.
2238 This function may need to overload OPERATOR_FNNAME.
2239 Must also handle REFERENCE_TYPEs for C++. */
2242 build_x_indirect_ref (tree expr, const char *errorstring)
2244 tree orig_expr = expr;
2247 if (processing_template_decl)
2249 if (type_dependent_expression_p (expr))
2250 return build_min_nt (INDIRECT_REF, expr);
2251 expr = build_non_dependent_expr (expr);
2254 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2255 NULL_TREE, /*overloaded_p=*/NULL);
2257 rval = build_indirect_ref (expr, errorstring);
2259 if (processing_template_decl && rval != error_mark_node)
2260 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2266 build_indirect_ref (tree ptr, const char *errorstring)
2270 if (ptr == error_mark_node)
2271 return error_mark_node;
2273 if (ptr == current_class_ptr)
2274 return current_class_ref;
2276 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2277 ? ptr : decay_conversion (ptr));
2278 type = TREE_TYPE (pointer);
2280 if (POINTER_TYPE_P (type))
2284 If the type of the expression is "pointer to T," the type
2285 of the result is "T."
2287 We must use the canonical variant because certain parts of
2288 the back end, like fold, do pointer comparisons between
2290 tree t = canonical_type_variant (TREE_TYPE (type));
2292 if (VOID_TYPE_P (t))
2294 /* A pointer to incomplete type (other than cv void) can be
2295 dereferenced [expr.unary.op]/1 */
2296 error ("%qT is not a pointer-to-object type", type);
2297 return error_mark_node;
2299 else if (TREE_CODE (pointer) == ADDR_EXPR
2300 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2301 /* The POINTER was something like `&x'. We simplify `*&x' to
2303 return TREE_OPERAND (pointer, 0);
2306 tree ref = build1 (INDIRECT_REF, t, pointer);
2308 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2309 so that we get the proper error message if the result is used
2310 to assign to. Also, &* is supposed to be a no-op. */
2311 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2312 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2313 TREE_SIDE_EFFECTS (ref)
2314 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2318 /* `pointer' won't be an error_mark_node if we were given a
2319 pointer to member, so it's cool to check for this here. */
2320 else if (TYPE_PTR_TO_MEMBER_P (type))
2321 error ("invalid use of %qs on pointer to member", errorstring);
2322 else if (pointer != error_mark_node)
2325 error ("invalid type argument of %qs", errorstring);
2327 error ("invalid type argument");
2329 return error_mark_node;
2332 /* This handles expressions of the form "a[i]", which denotes
2335 This is logically equivalent in C to *(a+i), but we may do it differently.
2336 If A is a variable or a member, we generate a primitive ARRAY_REF.
2337 This avoids forcing the array out of registers, and can work on
2338 arrays that are not lvalues (for example, members of structures returned
2341 If INDEX is of some user-defined type, it must be converted to
2342 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2343 will inherit the type of the array, which will be some pointer type. */
2346 build_array_ref (tree array, tree idx)
2350 error ("subscript missing in array reference");
2351 return error_mark_node;
2354 if (TREE_TYPE (array) == error_mark_node
2355 || TREE_TYPE (idx) == error_mark_node)
2356 return error_mark_node;
2358 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2360 switch (TREE_CODE (array))
2364 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2365 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2366 TREE_OPERAND (array, 0), value);
2370 return build_conditional_expr
2371 (TREE_OPERAND (array, 0),
2372 build_array_ref (TREE_OPERAND (array, 1), idx),
2373 build_array_ref (TREE_OPERAND (array, 2), idx));
2379 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2383 warn_array_subscript_with_type_char (idx);
2385 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2387 error ("array subscript is not an integer");
2388 return error_mark_node;
2391 /* Apply integral promotions *after* noticing character types.
2392 (It is unclear why we do these promotions -- the standard
2393 does not say that we should. In fact, the natural thing would
2394 seem to be to convert IDX to ptrdiff_t; we're performing
2395 pointer arithmetic.) */
2396 idx = perform_integral_promotions (idx);
2398 /* An array that is indexed by a non-constant
2399 cannot be stored in a register; we must be able to do
2400 address arithmetic on its address.
2401 Likewise an array of elements of variable size. */
2402 if (TREE_CODE (idx) != INTEGER_CST
2403 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2404 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2407 if (!cxx_mark_addressable (array))
2408 return error_mark_node;
2411 /* An array that is indexed by a constant value which is not within
2412 the array bounds cannot be stored in a register either; because we
2413 would get a crash in store_bit_field/extract_bit_field when trying
2414 to access a non-existent part of the register. */
2415 if (TREE_CODE (idx) == INTEGER_CST
2416 && TYPE_DOMAIN (TREE_TYPE (array))
2417 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2419 if (!cxx_mark_addressable (array))
2420 return error_mark_node;
2423 if (pedantic && !lvalue_p (array))
2424 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2426 /* Note in C++ it is valid to subscript a `register' array, since
2427 it is valid to take the address of something with that
2428 storage specification. */
2432 while (TREE_CODE (foo) == COMPONENT_REF)
2433 foo = TREE_OPERAND (foo, 0);
2434 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2435 warning (OPT_Wextra, "subscripting array declared %<register%>");
2438 type = TREE_TYPE (TREE_TYPE (array));
2439 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2440 /* Array ref is const/volatile if the array elements are
2441 or if the array is.. */
2442 TREE_READONLY (rval)
2443 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2444 TREE_SIDE_EFFECTS (rval)
2445 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2446 TREE_THIS_VOLATILE (rval)
2447 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2448 return require_complete_type (fold_if_not_in_template (rval));
2452 tree ar = default_conversion (array);
2453 tree ind = default_conversion (idx);
2455 /* Put the integer in IND to simplify error checking. */
2456 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2463 if (ar == error_mark_node)
2466 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2468 error ("subscripted value is neither array nor pointer");
2469 return error_mark_node;
2471 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2473 error ("array subscript is not an integer");
2474 return error_mark_node;
2477 warn_array_subscript_with_type_char (idx);
2479 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2484 /* Resolve a pointer to member function. INSTANCE is the object
2485 instance to use, if the member points to a virtual member.
2487 This used to avoid checking for virtual functions if basetype
2488 has no virtual functions, according to an earlier ANSI draft.
2489 With the final ISO C++ rules, such an optimization is
2490 incorrect: A pointer to a derived member can be static_cast
2491 to pointer-to-base-member, as long as the dynamic object
2492 later has the right member. */
2495 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2497 if (TREE_CODE (function) == OFFSET_REF)
2498 function = TREE_OPERAND (function, 1);
2500 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2502 tree idx, delta, e1, e2, e3, vtbl, basetype;
2503 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2505 tree instance_ptr = *instance_ptrptr;
2506 tree instance_save_expr = 0;
2507 if (instance_ptr == error_mark_node)
2509 if (TREE_CODE (function) == PTRMEM_CST)
2511 /* Extracting the function address from a pmf is only
2512 allowed with -Wno-pmf-conversions. It only works for
2514 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2515 e1 = convert (fntype, e1);
2520 error ("object missing in use of %qE", function);
2521 return error_mark_node;
2525 if (TREE_SIDE_EFFECTS (instance_ptr))
2526 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2528 if (TREE_SIDE_EFFECTS (function))
2529 function = save_expr (function);
2531 /* Start by extracting all the information from the PMF itself. */
2532 e3 = pfn_from_ptrmemfunc (function);
2533 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2534 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2535 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2537 case ptrmemfunc_vbit_in_pfn:
2538 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2539 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2542 case ptrmemfunc_vbit_in_delta:
2543 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2544 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2551 /* Convert down to the right base before using the instance. A
2552 special case is that in a pointer to member of class C, C may
2553 be incomplete. In that case, the function will of course be
2554 a member of C, and no conversion is required. In fact,
2555 lookup_base will fail in that case, because incomplete
2556 classes do not have BINFOs. */
2557 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2558 if (!same_type_ignoring_top_level_qualifiers_p
2559 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2561 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2562 basetype, ba_check, NULL);
2563 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2565 if (instance_ptr == error_mark_node)
2566 return error_mark_node;
2568 /* ...and then the delta in the PMF. */
2569 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2570 instance_ptr, delta);
2572 /* Hand back the adjusted 'this' argument to our caller. */
2573 *instance_ptrptr = instance_ptr;
2575 /* Next extract the vtable pointer from the object. */
2576 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2578 vtbl = build_indirect_ref (vtbl, NULL);
2580 /* Finally, extract the function pointer from the vtable. */
2581 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2582 e2 = build_indirect_ref (e2, NULL);
2583 TREE_CONSTANT (e2) = 1;
2584 TREE_INVARIANT (e2) = 1;
2586 /* When using function descriptors, the address of the
2587 vtable entry is treated as a function pointer. */
2588 if (TARGET_VTABLE_USES_DESCRIPTORS)
2589 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2590 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2592 TREE_TYPE (e2) = TREE_TYPE (e3);
2593 e1 = build_conditional_expr (e1, e2, e3);
2595 /* Make sure this doesn't get evaluated first inside one of the
2596 branches of the COND_EXPR. */
2597 if (instance_save_expr)
2598 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2599 instance_save_expr, e1);
2607 build_function_call (tree function, tree params)
2609 tree fntype, fndecl;
2610 tree coerced_params;
2611 tree name = NULL_TREE;
2613 tree original = function;
2615 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2616 expressions, like those used for ObjC messenger dispatches. */
2617 function = objc_rewrite_function_call (function, params);
2619 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2620 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2621 if (TREE_CODE (function) == NOP_EXPR
2622 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2623 function = TREE_OPERAND (function, 0);
2625 if (TREE_CODE (function) == FUNCTION_DECL)
2627 name = DECL_NAME (function);
2629 mark_used (function);
2632 /* Convert anything with function type to a pointer-to-function. */
2633 if (pedantic && DECL_MAIN_P (function))
2634 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2636 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2637 (because calling an inline function does not mean the function
2638 needs to be separately compiled). */
2640 if (DECL_INLINE (function))
2641 function = inline_conversion (function);
2643 function = build_addr_func (function);
2649 function = build_addr_func (function);
2652 if (function == error_mark_node)
2653 return error_mark_node;
2655 fntype = TREE_TYPE (function);
2657 if (TYPE_PTRMEMFUNC_P (fntype))
2659 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2660 "function in %<%E (...)%>",
2662 return error_mark_node;
2665 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2666 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2668 if (!((TREE_CODE (fntype) == POINTER_TYPE
2669 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2671 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2673 error ("%qE cannot be used as a function", original);
2674 return error_mark_node;
2677 /* fntype now gets the type of function pointed to. */
2678 fntype = TREE_TYPE (fntype);
2680 /* Convert the parameters to the types declared in the
2681 function prototype, or apply default promotions. */
2683 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2684 params, fndecl, LOOKUP_NORMAL);
2685 if (coerced_params == error_mark_node)
2686 return error_mark_node;
2688 /* Check for errors in format strings and inappropriately
2691 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2692 TYPE_ARG_TYPES (fntype));
2694 return build_cxx_call (function, coerced_params);
2697 /* Convert the actual parameter expressions in the list VALUES
2698 to the types in the list TYPELIST.
2699 If parmdecls is exhausted, or when an element has NULL as its type,
2700 perform the default conversions.
2702 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2704 This is also where warnings about wrong number of args are generated.
2706 Return a list of expressions for the parameters as converted.
2708 Both VALUES and the returned value are chains of TREE_LIST nodes
2709 with the elements of the list in the TREE_VALUE slots of those nodes.
2711 In C++, unspecified trailing parameters can be filled in with their
2712 default arguments, if such were specified. Do so here. */
2715 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2717 tree typetail, valtail;
2718 tree result = NULL_TREE;
2719 const char *called_thing = 0;
2722 /* Argument passing is always copy-initialization. */
2723 flags |= LOOKUP_ONLYCONVERTING;
2727 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2729 if (DECL_NAME (fndecl) == NULL_TREE
2730 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2731 called_thing = "constructor";
2733 called_thing = "member function";
2736 called_thing = "function";
2739 for (valtail = values, typetail = typelist;
2741 valtail = TREE_CHAIN (valtail), i++)
2743 tree type = typetail ? TREE_VALUE (typetail) : 0;
2744 tree val = TREE_VALUE (valtail);
2746 if (val == error_mark_node || type == error_mark_node)
2747 return error_mark_node;
2749 if (type == void_type_node)
2753 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2754 error ("at this point in file");
2757 error ("too many arguments to function");
2758 /* In case anybody wants to know if this argument
2761 TREE_TYPE (tree_last (result)) = error_mark_node;
2765 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2766 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2767 if (TREE_CODE (val) == NOP_EXPR
2768 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2769 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2770 val = TREE_OPERAND (val, 0);
2772 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2774 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2775 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2776 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2777 val = decay_conversion (val);
2780 if (val == error_mark_node)
2781 return error_mark_node;
2785 /* Formal parm type is specified by a function prototype. */
2788 if (!COMPLETE_TYPE_P (complete_type (type)))
2791 error ("parameter %P of %qD has incomplete type %qT",
2794 error ("parameter %P has incomplete type %qT", i, type);
2795 parmval = error_mark_node;
2799 parmval = convert_for_initialization
2800 (NULL_TREE, type, val, flags,
2801 "argument passing", fndecl, i);
2802 parmval = convert_for_arg_passing (type, parmval);
2805 if (parmval == error_mark_node)
2806 return error_mark_node;
2808 result = tree_cons (NULL_TREE, parmval, result);
2812 if (fndecl && DECL_BUILT_IN (fndecl)
2813 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2814 /* Don't do ellipsis conversion for __built_in_constant_p
2815 as this will result in spurious warnings for non-POD
2817 val = require_complete_type (val);
2819 val = convert_arg_to_ellipsis (val);
2821 result = tree_cons (NULL_TREE, val, result);
2825 typetail = TREE_CHAIN (typetail);
2828 if (typetail != 0 && typetail != void_list_node)
2830 /* See if there are default arguments that can be used. */
2831 if (TREE_PURPOSE (typetail)
2832 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2834 for (; typetail != void_list_node; ++i)
2837 = convert_default_arg (TREE_VALUE (typetail),
2838 TREE_PURPOSE (typetail),
2841 if (parmval == error_mark_node)
2842 return error_mark_node;
2844 result = tree_cons (0, parmval, result);
2845 typetail = TREE_CHAIN (typetail);
2846 /* ends with `...'. */
2847 if (typetail == NULL_TREE)
2855 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2856 error ("at this point in file");
2859 error ("too few arguments to function");
2860 return error_mark_node;
2864 return nreverse (result);
2867 /* Build a binary-operation expression, after performing default
2868 conversions on the operands. CODE is the kind of expression to build. */
2871 build_x_binary_op (enum tree_code code, tree arg1, tree arg2,
2881 if (processing_template_decl)
2883 if (type_dependent_expression_p (arg1)
2884 || type_dependent_expression_p (arg2))
2885 return build_min_nt (code, arg1, arg2);
2886 arg1 = build_non_dependent_expr (arg1);
2887 arg2 = build_non_dependent_expr (arg2);
2890 if (code == DOTSTAR_EXPR)
2891 expr = build_m_component_ref (arg1, arg2);
2893 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2896 if (processing_template_decl && expr != error_mark_node)
2897 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2902 /* Build a binary-operation expression without default conversions.
2903 CODE is the kind of expression to build.
2904 This function differs from `build' in several ways:
2905 the data type of the result is computed and recorded in it,
2906 warnings are generated if arg data types are invalid,
2907 special handling for addition and subtraction of pointers is known,
2908 and some optimization is done (operations on narrow ints
2909 are done in the narrower type when that gives the same result).
2910 Constant folding is also done before the result is returned.
2912 Note that the operands will never have enumeral types
2913 because either they have just had the default conversions performed
2914 or they have both just been converted to some other type in which
2915 the arithmetic is to be done.
2917 C++: must do special pointer arithmetic when implementing
2918 multiple inheritance, and deal with pointer to member functions. */
2921 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2922 int convert_p ATTRIBUTE_UNUSED)
2925 enum tree_code code0, code1;
2927 const char *invalid_op_diag;
2929 /* Expression code to give to the expression when it is built.
2930 Normally this is CODE, which is what the caller asked for,
2931 but in some special cases we change it. */
2932 enum tree_code resultcode = code;
2934 /* Data type in which the computation is to be performed.
2935 In the simplest cases this is the common type of the arguments. */
2936 tree result_type = NULL;
2938 /* Nonzero means operands have already been type-converted
2939 in whatever way is necessary.
2940 Zero means they need to be converted to RESULT_TYPE. */
2943 /* Nonzero means create the expression with this type, rather than
2945 tree build_type = 0;
2947 /* Nonzero means after finally constructing the expression
2948 convert it to this type. */
2949 tree final_type = 0;
2953 /* Nonzero if this is an operation like MIN or MAX which can
2954 safely be computed in short if both args are promoted shorts.
2955 Also implies COMMON.
2956 -1 indicates a bitwise operation; this makes a difference
2957 in the exact conditions for when it is safe to do the operation
2958 in a narrower mode. */
2961 /* Nonzero if this is a comparison operation;
2962 if both args are promoted shorts, compare the original shorts.
2963 Also implies COMMON. */
2964 int short_compare = 0;
2966 /* Nonzero if this is a right-shift operation, which can be computed on the
2967 original short and then promoted if the operand is a promoted short. */
2968 int short_shift = 0;
2970 /* Nonzero means set RESULT_TYPE to the common type of the args. */
2973 /* True if both operands have arithmetic type. */
2974 bool arithmetic_types_p;
2976 /* Apply default conversions. */
2980 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2981 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2982 || code == TRUTH_XOR_EXPR)
2984 if (!really_overloaded_fn (op0))
2985 op0 = decay_conversion (op0);
2986 if (!really_overloaded_fn (op1))
2987 op1 = decay_conversion (op1);
2991 if (!really_overloaded_fn (op0))
2992 op0 = default_conversion (op0);
2993 if (!really_overloaded_fn (op1))
2994 op1 = default_conversion (op1);
2997 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2998 STRIP_TYPE_NOPS (op0);
2999 STRIP_TYPE_NOPS (op1);
3001 /* DTRT if one side is an overloaded function, but complain about it. */
3002 if (type_unknown_p (op0))
3004 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3005 if (t != error_mark_node)
3007 pedwarn ("assuming cast to type %qT from overloaded function",
3012 if (type_unknown_p (op1))
3014 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3015 if (t != error_mark_node)
3017 pedwarn ("assuming cast to type %qT from overloaded function",
3023 type0 = TREE_TYPE (op0);
3024 type1 = TREE_TYPE (op1);
3026 /* The expression codes of the data types of the arguments tell us
3027 whether the arguments are integers, floating, pointers, etc. */
3028 code0 = TREE_CODE (type0);
3029 code1 = TREE_CODE (type1);
3031 /* If an error was already reported for one of the arguments,
3032 avoid reporting another error. */
3034 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3035 return error_mark_node;
3037 if ((invalid_op_diag
3038 = targetm.invalid_binary_op (code, type0, type1)))
3040 error (invalid_op_diag);
3041 return error_mark_node;
3047 /* Subtraction of two similar pointers.
3048 We must subtract them as integers, then divide by object size. */
3049 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3050 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3052 return pointer_diff (op0, op1, common_type (type0, type1));
3053 /* In all other cases except pointer - int, the usual arithmetic
3055 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3060 /* The pointer - int case is just like pointer + int; fall
3063 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3064 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3068 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3069 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3070 if (processing_template_decl)
3072 result_type = TREE_TYPE (ptr_operand);
3075 return cp_pointer_int_sum (code,
3086 case TRUNC_DIV_EXPR:
3088 case FLOOR_DIV_EXPR:
3089 case ROUND_DIV_EXPR:
3090 case EXACT_DIV_EXPR:
3091 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3092 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3093 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3094 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3096 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3097 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3098 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3099 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3101 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3102 code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3103 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
3104 code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3106 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
3107 resultcode = RDIV_EXPR;
3109 /* When dividing two signed integers, we have to promote to int.
3110 unless we divide by a constant != -1. Note that default
3111 conversion will have been performed on the operands at this
3112 point, so we have to dig out the original type to find out if
3114 shorten = ((TREE_CODE (op0) == NOP_EXPR
3115 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3116 || (TREE_CODE (op1) == INTEGER_CST
3117 && ! integer_all_onesp (op1)));
3126 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3127 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3131 case TRUNC_MOD_EXPR:
3132 case FLOOR_MOD_EXPR:
3133 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3134 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3135 else if (code1 == REAL_TYPE && real_zerop (op1))
3136 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3138 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3140 /* Although it would be tempting to shorten always here, that loses
3141 on some targets, since the modulo instruction is undefined if the
3142 quotient can't be represented in the computation mode. We shorten
3143 only if unsigned or if dividing by something we know != -1. */
3144 shorten = ((TREE_CODE (op0) == NOP_EXPR
3145 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3146 || (TREE_CODE (op1) == INTEGER_CST
3147 && ! integer_all_onesp (op1)));
3152 case TRUTH_ANDIF_EXPR:
3153 case TRUTH_ORIF_EXPR:
3154 case TRUTH_AND_EXPR:
3156 result_type = boolean_type_node;
3159 /* Shift operations: result has same type as first operand;
3160 always convert second operand to int.
3161 Also set SHORT_SHIFT if shifting rightward. */
3164 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3166 result_type = type0;
3167 if (TREE_CODE (op1) == INTEGER_CST)
3169 if (tree_int_cst_lt (op1, integer_zero_node))
3170 warning (0, "right shift count is negative");
3173 if (! integer_zerop (op1))
3175 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3176 warning (0, "right shift count >= width of type");
3179 /* Convert the shift-count to an integer, regardless of
3180 size of value being shifted. */
3181 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3182 op1 = cp_convert (integer_type_node, op1);
3183 /* Avoid converting op1 to result_type later. */
3189 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3191 result_type = type0;
3192 if (TREE_CODE (op1) == INTEGER_CST)
3194 if (tree_int_cst_lt (op1, integer_zero_node))
3195 warning (0, "left shift count is negative");
3196 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3197 warning (0, "left shift count >= width of type");
3199 /* Convert the shift-count to an integer, regardless of
3200 size of value being shifted. */
3201 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3202 op1 = cp_convert (integer_type_node, op1);
3203 /* Avoid converting op1 to result_type later. */
3210 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3212 result_type = type0;
3213 if (TREE_CODE (op1) == INTEGER_CST)
3215 if (tree_int_cst_lt (op1, integer_zero_node))
3216 warning (0, (code == LROTATE_EXPR)
3217 ? G_("left rotate count is negative")
3218 : G_("right rotate count is negative"));
3219 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3220 warning (0, (code == LROTATE_EXPR)
3221 ? G_("left rotate count >= width of type")
3222 : G_("right rotate count >= width of type"));
3224 /* Convert the shift-count to an integer, regardless of
3225 size of value being shifted. */
3226 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3227 op1 = cp_convert (integer_type_node, op1);
3233 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3234 warning (OPT_Wfloat_equal,
3235 "comparing floating point with == or != is unsafe");
3236 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3237 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3238 warning (OPT_Wstring_literal_comparison,
3239 "comparison with string literal");
3241 build_type = boolean_type_node;
3242 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3243 || code0 == COMPLEX_TYPE)
3244 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3245 || code1 == COMPLEX_TYPE))
3247 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3248 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3249 result_type = composite_pointer_type (type0, type1, op0, op1,
3251 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3252 && null_ptr_cst_p (op1))
3253 result_type = type0;
3254 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3255 && null_ptr_cst_p (op0))
3256 result_type = type1;
3257 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3259 result_type = type0;
3260 error ("ISO C++ forbids comparison between pointer and integer");
3262 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3264 result_type = type1;
3265 error ("ISO C++ forbids comparison between pointer and integer");
3267 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3269 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3270 == ptrmemfunc_vbit_in_delta)
3272 tree pfn0 = pfn_from_ptrmemfunc (op0);
3273 tree delta0 = build_ptrmemfunc_access_expr (op0,
3275 tree e1 = cp_build_binary_op (EQ_EXPR,
3277 fold_convert (TREE_TYPE (pfn0),
3278 integer_zero_node));
3279 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3282 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3283 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3284 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3288 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3289 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3291 result_type = TREE_TYPE (op0);
3293 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3294 return cp_build_binary_op (code, op1, op0);
3295 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3296 && same_type_p (type0, type1))
3298 /* E will be the final comparison. */
3300 /* E1 and E2 are for scratch. */
3308 if (TREE_SIDE_EFFECTS (op0))
3309 op0 = save_expr (op0);
3310 if (TREE_SIDE_EFFECTS (op1))
3311 op1 = save_expr (op1);
3313 pfn0 = pfn_from_ptrmemfunc (op0);
3314 pfn1 = pfn_from_ptrmemfunc (op1);
3315 delta0 = build_ptrmemfunc_access_expr (op0,
3317 delta1 = build_ptrmemfunc_access_expr (op1,
3319 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3320 == ptrmemfunc_vbit_in_delta)
3325 && ((op0.delta == op1.delta)
3326 || (!op0.pfn && op0.delta & 1 == 0
3327 && op1.delta & 1 == 0))
3329 The reason for the `!op0.pfn' bit is that a NULL
3330 pointer-to-member is any member with a zero PFN and
3331 LSB of the DELTA field is 0. */
3333 e1 = cp_build_binary_op (BIT_AND_EXPR,
3336 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3337 e2 = cp_build_binary_op (BIT_AND_EXPR,
3340 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3341 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3342 e2 = cp_build_binary_op (EQ_EXPR,
3344 fold_convert (TREE_TYPE (pfn0),
3345 integer_zero_node));
3346 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3347 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3348 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3355 && (!op0.pfn || op0.delta == op1.delta))
3357 The reason for the `!op0.pfn' bit is that a NULL
3358 pointer-to-member is any member with a zero PFN; the
3359 DELTA field is unspecified. */
3361 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3362 e2 = cp_build_binary_op (EQ_EXPR,
3364 fold_convert (TREE_TYPE (pfn0),
3365 integer_zero_node));
3366 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3368 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3369 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3370 if (code == EQ_EXPR)
3372 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3376 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3377 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3379 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3380 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3388 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3389 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3391 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3392 result_type = composite_pointer_type (type0, type1, op0, op1,
3400 if (TREE_CODE (orig_op0) == STRING_CST
3401 || TREE_CODE (orig_op1) == STRING_CST)
3402 warning (OPT_Wstring_literal_comparison,
3403 "comparison with string literal");
3405 build_type = boolean_type_node;
3406 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3407 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3409 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3410 result_type = composite_pointer_type (type0, type1, op0, op1,
3412 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3413 && integer_zerop (op1))
3414 result_type = type0;
3415 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3416 && integer_zerop (op0))
3417 result_type = type1;
3418 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3420 result_type = type0;
3421 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3423 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3425 result_type = type1;
3426 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3430 case UNORDERED_EXPR:
3437 build_type = integer_type_node;
3438 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3440 error ("unordered comparison on non-floating point argument");
3441 return error_mark_node;
3450 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3451 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3452 || code1 == COMPLEX_TYPE)))
3453 arithmetic_types_p = 1;
3456 arithmetic_types_p = 0;
3457 /* Vector arithmetic is only allowed when both sides are vectors. */
3458 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3460 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3461 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3464 binary_op_error (code);
3465 return error_mark_node;
3467 arithmetic_types_p = 1;
3470 /* Determine the RESULT_TYPE, if it is not already known. */
3472 && arithmetic_types_p
3473 && (shorten || common || short_compare))
3474 result_type = common_type (type0, type1);
3478 error ("invalid operands of types %qT and %qT to binary %qO",
3479 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3480 return error_mark_node;
3483 /* If we're in a template, the only thing we need to know is the
3485 if (processing_template_decl)
3486 return build2 (resultcode,
3487 build_type ? build_type : result_type,
3490 if (arithmetic_types_p)
3492 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3494 /* For certain operations (which identify themselves by shorten != 0)
3495 if both args were extended from the same smaller type,
3496 do the arithmetic in that type and then extend.
3498 shorten !=0 and !=1 indicates a bitwise operation.
3499 For them, this optimization is safe only if
3500 both args are zero-extended or both are sign-extended.
3501 Otherwise, we might change the result.
3502 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3503 but calculated in (unsigned short) it would be (unsigned short)-1. */
3505 if (shorten && none_complex)
3507 int unsigned0, unsigned1;
3508 tree arg0 = get_narrower (op0, &unsigned0);
3509 tree arg1 = get_narrower (op1, &unsigned1);
3510 /* UNS is 1 if the operation to be done is an unsigned one. */
3511 int uns = TYPE_UNSIGNED (result_type);
3514 final_type = result_type;
3516 /* Handle the case that OP0 does not *contain* a conversion
3517 but it *requires* conversion to FINAL_TYPE. */
3519 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3520 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3521 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3522 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3524 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3526 /* For bitwise operations, signedness of nominal type
3527 does not matter. Consider only how operands were extended. */
3531 /* Note that in all three cases below we refrain from optimizing
3532 an unsigned operation on sign-extended args.
3533 That would not be valid. */
3535 /* Both args variable: if both extended in same way
3536 from same width, do it in that width.
3537 Do it unsigned if args were zero-extended. */
3538 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3539 < TYPE_PRECISION (result_type))
3540 && (TYPE_PRECISION (TREE_TYPE (arg1))
3541 == TYPE_PRECISION (TREE_TYPE (arg0)))
3542 && unsigned0 == unsigned1
3543 && (unsigned0 || !uns))
3544 result_type = c_common_signed_or_unsigned_type
3545 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3546 else if (TREE_CODE (arg0) == INTEGER_CST
3547 && (unsigned1 || !uns)
3548 && (TYPE_PRECISION (TREE_TYPE (arg1))
3549 < TYPE_PRECISION (result_type))
3550 && (type = c_common_signed_or_unsigned_type
3551 (unsigned1, TREE_TYPE (arg1)),
3552 int_fits_type_p (arg0, type)))
3554 else if (TREE_CODE (arg1) == INTEGER_CST
3555 && (unsigned0 || !uns)
3556 && (TYPE_PRECISION (TREE_TYPE (arg0))
3557 < TYPE_PRECISION (result_type))
3558 && (type = c_common_signed_or_unsigned_type
3559 (unsigned0, TREE_TYPE (arg0)),
3560 int_fits_type_p (arg1, type)))
3564 /* Shifts can be shortened if shifting right. */
3569 tree arg0 = get_narrower (op0, &unsigned_arg);
3571 final_type = result_type;
3573 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3574 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3576 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3577 /* We can shorten only if the shift count is less than the
3578 number of bits in the smaller type size. */
3579 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3580 /* If arg is sign-extended and then unsigned-shifted,
3581 we can simulate this with a signed shift in arg's type
3582 only if the extended result is at least twice as wide
3583 as the arg. Otherwise, the shift could use up all the
3584 ones made by sign-extension and bring in zeros.
3585 We can't optimize that case at all, but in most machines
3586 it never happens because available widths are 2**N. */
3587 && (!TYPE_UNSIGNED (final_type)
3589 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3590 <= TYPE_PRECISION (result_type))))
3592 /* Do an unsigned shift if the operand was zero-extended. */
3594 = c_common_signed_or_unsigned_type (unsigned_arg,
3596 /* Convert value-to-be-shifted to that type. */
3597 if (TREE_TYPE (op0) != result_type)
3598 op0 = cp_convert (result_type, op0);
3603 /* Comparison operations are shortened too but differently.
3604 They identify themselves by setting short_compare = 1. */
3608 /* Don't write &op0, etc., because that would prevent op0
3609 from being kept in a register.
3610 Instead, make copies of the our local variables and
3611 pass the copies by reference, then copy them back afterward. */
3612 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3613 enum tree_code xresultcode = resultcode;
3615 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3617 return cp_convert (boolean_type_node, val);
3618 op0 = xop0, op1 = xop1;
3620 resultcode = xresultcode;
3623 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3624 && warn_sign_compare
3625 /* Do not warn until the template is instantiated; we cannot
3626 bound the ranges of the arguments until that point. */
3627 && !processing_template_decl)
3629 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3630 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3632 int unsignedp0, unsignedp1;
3633 tree primop0 = get_narrower (op0, &unsignedp0);
3634 tree primop1 = get_narrower (op1, &unsignedp1);
3636 /* Check for comparison of different enum types. */
3637 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3638 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3639 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3640 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3642 warning (0, "comparison between types %q#T and %q#T",
3643 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3646 /* Give warnings for comparisons between signed and unsigned
3647 quantities that may fail. */
3648 /* Do the checking based on the original operand trees, so that
3649 casts will be considered, but default promotions won't be. */
3651 /* Do not warn if the comparison is being done in a signed type,
3652 since the signed type will only be chosen if it can represent
3653 all the values of the unsigned type. */
3654 if (!TYPE_UNSIGNED (result_type))
3656 /* Do not warn if both operands are unsigned. */
3657 else if (op0_signed == op1_signed)
3659 /* Do not warn if the signed quantity is an unsuffixed
3660 integer literal (or some static constant expression
3661 involving such literals or a conditional expression
3662 involving such literals) and it is non-negative. */
3663 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3664 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3666 /* Do not warn if the comparison is an equality operation,
3667 the unsigned quantity is an integral constant and it does
3668 not use the most significant bit of result_type. */
3669 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3670 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3671 && int_fits_type_p (orig_op1, c_common_signed_type
3673 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3674 && int_fits_type_p (orig_op0, c_common_signed_type
3678 warning (0, "comparison between signed and unsigned integer expressions");
3680 /* Warn if two unsigned values are being compared in a size
3681 larger than their original size, and one (and only one) is the
3682 result of a `~' operator. This comparison will always fail.
3684 Also warn if one operand is a constant, and the constant does not
3685 have all bits set that are set in the ~ operand when it is
3688 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3689 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3691 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3692 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3693 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3694 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3696 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3699 HOST_WIDE_INT constant, mask;
3703 if (host_integerp (primop0, 0))
3706 unsignedp = unsignedp1;
3707 constant = tree_low_cst (primop0, 0);
3712 unsignedp = unsignedp0;
3713 constant = tree_low_cst (primop1, 0);
3716 bits = TYPE_PRECISION (TREE_TYPE (primop));
3717 if (bits < TYPE_PRECISION (result_type)
3718 && bits < HOST_BITS_PER_LONG && unsignedp)
3720 mask = (~ (HOST_WIDE_INT) 0) << bits;
3721 if ((mask & constant) != mask)
3722 warning (0, "comparison of promoted ~unsigned with constant");
3725 else if (unsignedp0 && unsignedp1
3726 && (TYPE_PRECISION (TREE_TYPE (primop0))
3727 < TYPE_PRECISION (result_type))
3728 && (TYPE_PRECISION (TREE_TYPE (primop1))
3729 < TYPE_PRECISION (result_type)))
3730 warning (0, "comparison of promoted ~unsigned with unsigned");
3735 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3736 Then the expression will be built.
3737 It will be given type FINAL_TYPE if that is nonzero;
3738 otherwise, it will be given type RESULT_TYPE. */
3740 /* Issue warnings about peculiar, but valid, uses of NULL. */
3741 if (/* It's reasonable to use pointer values as operands of &&
3742 and ||, so NULL is no exception. */
3743 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3744 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3745 (orig_op0 == null_node
3746 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3747 /* Or vice versa. */
3748 || (orig_op1 == null_node
3749 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3750 /* Or, both are NULL and the operation was not a comparison. */
3751 || (orig_op0 == null_node && orig_op1 == null_node
3752 && code != EQ_EXPR && code != NE_EXPR)))
3753 /* Some sort of arithmetic operation involving NULL was
3754 performed. Note that pointer-difference and pointer-addition
3755 have already been handled above, and so we don't end up here in
3757 warning (0, "NULL used in arithmetic");
3761 if (TREE_TYPE (op0) != result_type)
3762 op0 = cp_convert (result_type, op0);
3763 if (TREE_TYPE (op1) != result_type)
3764 op1 = cp_convert (result_type, op1);
3766 if (op0 == error_mark_node || op1 == error_mark_node)
3767 return error_mark_node;
3770 if (build_type == NULL_TREE)
3771 build_type = result_type;
3773 result = build2 (resultcode, build_type, op0, op1);
3774 result = fold_if_not_in_template (result);
3775 if (final_type != 0)
3776 result = cp_convert (final_type, result);
3780 /* Return a tree for the sum or difference (RESULTCODE says which)
3781 of pointer PTROP and integer INTOP. */
3784 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3786 tree res_type = TREE_TYPE (ptrop);
3788 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3789 in certain circumstance (when it's valid to do so). So we need
3790 to make sure it's complete. We don't need to check here, if we
3791 can actually complete it at all, as those checks will be done in
3792 pointer_int_sum() anyway. */
3793 complete_type (TREE_TYPE (res_type));
3795 return pointer_int_sum (resultcode, ptrop,
3796 fold_if_not_in_template (intop));
3799 /* Return a tree for the difference of pointers OP0 and OP1.
3800 The resulting tree has type int. */
3803 pointer_diff (tree op0, tree op1, tree ptrtype)
3806 tree restype = ptrdiff_type_node;
3807 tree target_type = TREE_TYPE (ptrtype);
3809 if (!complete_type_or_else (target_type, NULL_TREE))
3810 return error_mark_node;
3812 if (pedantic || warn_pointer_arith)
3814 if (TREE_CODE (target_type) == VOID_TYPE)
3815 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3816 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3817 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3818 if (TREE_CODE (target_type) == METHOD_TYPE)
3819 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3822 /* First do the subtraction as integers;
3823 then drop through to build the divide operator. */
3825 op0 = cp_build_binary_op (MINUS_EXPR,
3826 cp_convert (restype, op0),
3827 cp_convert (restype, op1));
3829 /* This generates an error if op1 is a pointer to an incomplete type. */
3830 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3831 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3833 op1 = (TYPE_PTROB_P (ptrtype)
3834 ? size_in_bytes (target_type)
3835 : integer_one_node);
3837 /* Do the division. */
3839 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3840 return fold_if_not_in_template (result);
3843 /* Construct and perhaps optimize a tree representation
3844 for a unary operation. CODE, a tree_code, specifies the operation
3845 and XARG is the operand. */
3848 build_x_unary_op (enum tree_code code, tree xarg)
3850 tree orig_expr = xarg;
3854 if (processing_template_decl)
3856 if (type_dependent_expression_p (xarg))
3857 return build_min_nt (code, xarg, NULL_TREE);
3859 xarg = build_non_dependent_expr (xarg);
3864 /* [expr.unary.op] says:
3866 The address of an object of incomplete type can be taken.
3868 (And is just the ordinary address operator, not an overloaded
3869 "operator &".) However, if the type is a template
3870 specialization, we must complete the type at this point so that
3871 an overloaded "operator &" will be available if required. */
3872 if (code == ADDR_EXPR
3873 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3874 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3875 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3876 || (TREE_CODE (xarg) == OFFSET_REF)))
3877 /* Don't look for a function. */;
3879 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3880 /*overloaded_p=*/NULL);
3881 if (!exp && code == ADDR_EXPR)
3883 /* A pointer to member-function can be formed only by saying
3885 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3886 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3888 if (TREE_CODE (xarg) != OFFSET_REF
3889 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3891 error ("invalid use of %qE to form a pointer-to-member-function",
3893 if (TREE_CODE (xarg) != OFFSET_REF)
3894 inform (" a qualified-id is required");
3895 return error_mark_node;
3899 error ("parentheses around %qE cannot be used to form a"
3900 " pointer-to-member-function",
3902 PTRMEM_OK_P (xarg) = 1;
3906 if (TREE_CODE (xarg) == OFFSET_REF)
3908 ptrmem = PTRMEM_OK_P (xarg);
3910 if (!ptrmem && !flag_ms_extensions
3911 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3913 /* A single non-static member, make sure we don't allow a
3914 pointer-to-member. */
3915 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3916 TREE_OPERAND (xarg, 0),
3917 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3918 PTRMEM_OK_P (xarg) = ptrmem;
3921 else if (TREE_CODE (xarg) == TARGET_EXPR)
3922 warning (0, "taking address of temporary");
3923 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3926 if (processing_template_decl && exp != error_mark_node)
3927 exp = build_min_non_dep (code, exp, orig_expr,
3928 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3929 if (TREE_CODE (exp) == ADDR_EXPR)
3930 PTRMEM_OK_P (exp) = ptrmem;
3934 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3935 constants, where a null value is represented by an INTEGER_CST of
3939 cp_truthvalue_conversion (tree expr)
3941 tree type = TREE_TYPE (expr);
3942 if (TYPE_PTRMEM_P (type))
3943 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3945 return c_common_truthvalue_conversion (expr);
3948 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3951 condition_conversion (tree expr)
3954 if (processing_template_decl)
3956 t = perform_implicit_conversion (boolean_type_node, expr);
3957 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3961 /* Return an ADDR_EXPR giving the address of T. This function
3962 attempts no optimizations or simplifications; it is a low-level
3966 build_address (tree t)
3970 if (error_operand_p (t) || !cxx_mark_addressable (t))
3971 return error_mark_node;
3973 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3978 /* Return a NOP_EXPR converting EXPR to TYPE. */
3981 build_nop (tree type, tree expr)
3983 if (type == error_mark_node || error_operand_p (expr))
3985 return build1 (NOP_EXPR, type, expr);
3988 /* C++: Must handle pointers to members.
3990 Perhaps type instantiation should be extended to handle conversion
3991 from aggregates to types we don't yet know we want? (Or are those
3992 cases typically errors which should be reported?)
3994 NOCONVERT nonzero suppresses the default promotions
3995 (such as from short to int). */
3998 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4000 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4003 const char *errstring = NULL;
4005 const char *invalid_op_diag;
4007 if (arg == error_mark_node)
4008 return error_mark_node;
4010 if ((invalid_op_diag
4011 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4016 error (invalid_op_diag);
4017 return error_mark_node;
4022 case UNARY_PLUS_EXPR:
4025 int flags = WANT_ARITH | WANT_ENUM;
4026 /* Unary plus (but not unary minus) is allowed on pointers. */
4027 if (code == UNARY_PLUS_EXPR)
4028 flags |= WANT_POINTER;
4029 arg = build_expr_type_conversion (flags, arg, true);
4031 errstring = (code == NEGATE_EXPR
4032 ? "wrong type argument to unary minus"
4033 : "wrong type argument to unary plus");
4036 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4037 arg = perform_integral_promotions (arg);
4039 /* Make sure the result is not an lvalue: a unary plus or minus
4040 expression is always a rvalue. */
4047 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4051 arg = default_conversion (arg);
4053 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4056 errstring = "wrong type argument to bit-complement";
4057 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4058 arg = perform_integral_promotions (arg);
4062 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4063 errstring = "wrong type argument to abs";
4064 else if (!noconvert)
4065 arg = default_conversion (arg);
4069 /* Conjugating a real value is a no-op, but allow it anyway. */
4070 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4071 errstring = "wrong type argument to conjugation";
4072 else if (!noconvert)
4073 arg = default_conversion (arg);
4076 case TRUTH_NOT_EXPR:
4077 arg = perform_implicit_conversion (boolean_type_node, arg);
4078 val = invert_truthvalue (arg);
4079 if (arg != error_mark_node)
4081 errstring = "in argument to unary !";
4088 if (TREE_CODE (arg) == COMPLEX_CST)
4089 return TREE_REALPART (arg);
4090 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4092 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4093 return fold_if_not_in_template (arg);
4099 if (TREE_CODE (arg) == COMPLEX_CST)
4100 return TREE_IMAGPART (arg);
4101 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4103 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4104 return fold_if_not_in_template (arg);
4107 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4109 case PREINCREMENT_EXPR:
4110 case POSTINCREMENT_EXPR:
4111 case PREDECREMENT_EXPR:
4112 case POSTDECREMENT_EXPR:
4113 /* Handle complex lvalues (when permitted)
4114 by reduction to simpler cases. */
4116 val = unary_complex_lvalue (code, arg);
4120 /* Increment or decrement the real part of the value,
4121 and don't change the imaginary part. */
4122 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4126 arg = stabilize_reference (arg);
4127 real = build_unary_op (REALPART_EXPR, arg, 1);
4128 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4129 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4130 build_unary_op (code, real, 1), imag);
4133 /* Report invalid types. */
4135 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4138 if (code == PREINCREMENT_EXPR)
4139 errstring ="no pre-increment operator for type";
4140 else if (code == POSTINCREMENT_EXPR)
4141 errstring ="no post-increment operator for type";
4142 else if (code == PREDECREMENT_EXPR)
4143 errstring ="no pre-decrement operator for type";
4145 errstring ="no post-decrement operator for type";
4149 /* Report something read-only. */
4151 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4152 || TREE_READONLY (arg))
4153 readonly_error (arg, ((code == PREINCREMENT_EXPR
4154 || code == POSTINCREMENT_EXPR)
4155 ? "increment" : "decrement"),
4160 tree result_type = TREE_TYPE (arg);
4162 arg = get_unwidened (arg, 0);
4163 argtype = TREE_TYPE (arg);
4165 /* ARM $5.2.5 last annotation says this should be forbidden. */
4166 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4167 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4168 ? G_("ISO C++ forbids incrementing an enum")
4169 : G_("ISO C++ forbids decrementing an enum"));
4171 /* Compute the increment. */
4173 if (TREE_CODE (argtype) == POINTER_TYPE)
4175 tree type = complete_type (TREE_TYPE (argtype));
4177 if (!COMPLETE_OR_VOID_TYPE_P (type))
4178 error (((code == PREINCREMENT_EXPR
4179 || code == POSTINCREMENT_EXPR))
4180 ? G_("cannot increment a pointer to incomplete type %qT")
4181 : G_("cannot decrement a pointer to incomplete type %qT"),
4182 TREE_TYPE (argtype));
4183 else if ((pedantic || warn_pointer_arith)
4184 && !TYPE_PTROB_P (argtype))
4185 pedwarn ((code == PREINCREMENT_EXPR
4186 || code == POSTINCREMENT_EXPR)
4187 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4188 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4190 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4193 inc = integer_one_node;
4195 inc = cp_convert (argtype, inc);
4197 /* Handle incrementing a cast-expression. */
4199 switch (TREE_CODE (arg))
4204 case FIX_TRUNC_EXPR:
4206 tree incremented, modify, value, compound;
4207 if (! lvalue_p (arg) && pedantic)
4208 pedwarn ("cast to non-reference type used as lvalue");
4209 arg = stabilize_reference (arg);
4210 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4213 value = save_expr (arg);
4214 incremented = build2 (((code == PREINCREMENT_EXPR
4215 || code == POSTINCREMENT_EXPR)
4216 ? PLUS_EXPR : MINUS_EXPR),
4217 argtype, value, inc);
4219 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4220 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4223 /* Eliminate warning about unused result of + or -. */
4224 TREE_NO_WARNING (compound) = 1;
4232 /* Complain about anything else that is not a true lvalue. */
4233 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4234 || code == POSTINCREMENT_EXPR)
4235 ? lv_increment : lv_decrement)))
4236 return error_mark_node;
4238 /* Forbid using -- on `bool'. */
4239 if (same_type_p (TREE_TYPE (arg), boolean_type_node))
4241 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4243 error ("invalid use of %<--%> on bool variable %qD", arg);
4244 return error_mark_node;
4246 val = boolean_increment (code, arg);
4249 val = build2 (code, TREE_TYPE (arg), arg, inc);
4251 TREE_SIDE_EFFECTS (val) = 1;
4252 return cp_convert (result_type, val);
4256 /* Note that this operation never does default_conversion
4257 regardless of NOCONVERT. */
4259 argtype = lvalue_type (arg);
4261 if (TREE_CODE (arg) == OFFSET_REF)
4264 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4266 tree type = build_pointer_type (TREE_TYPE (argtype));
4267 arg = build1 (CONVERT_EXPR, type, arg);
4270 else if (pedantic && DECL_MAIN_P (arg))
4272 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4274 /* Let &* cancel out to simplify resulting code. */
4275 if (TREE_CODE (arg) == INDIRECT_REF)
4277 /* We don't need to have `current_class_ptr' wrapped in a
4278 NON_LVALUE_EXPR node. */
4279 if (arg == current_class_ref)
4280 return current_class_ptr;
4282 arg = TREE_OPERAND (arg, 0);
4283 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4285 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4286 arg = build1 (CONVERT_EXPR, type, arg);
4289 /* Don't let this be an lvalue. */
4294 /* Uninstantiated types are all functions. Taking the
4295 address of a function is a no-op, so just return the
4298 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4299 || !IDENTIFIER_OPNAME_P (arg));
4301 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4302 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4304 /* They're trying to take the address of a unique non-static
4305 member function. This is ill-formed (except in MS-land),
4306 but let's try to DTRT.
4307 Note: We only handle unique functions here because we don't
4308 want to complain if there's a static overload; non-unique
4309 cases will be handled by instantiate_type. But we need to
4310 handle this case here to allow casts on the resulting PMF.
4311 We could defer this in non-MS mode, but it's easier to give
4312 a useful error here. */
4314 /* Inside constant member functions, the `this' pointer
4315 contains an extra const qualifier. TYPE_MAIN_VARIANT
4316 is used here to remove this const from the diagnostics
4317 and the created OFFSET_REF. */
4318 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4319 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4322 if (! flag_ms_extensions)
4324 tree name = DECL_NAME (fn);
4325 if (current_class_type
4326 && TREE_OPERAND (arg, 0) == current_class_ref)
4327 /* An expression like &memfn. */
4328 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4329 " or parenthesized non-static member function to form"
4330 " a pointer to member function. Say %<&%T::%D%>",
4333 pedwarn ("ISO C++ forbids taking the address of a bound member"
4334 " function to form a pointer to member function."
4338 arg = build_offset_ref (base, fn, /*address_p=*/true);
4342 if (type_unknown_p (arg))
4343 return build1 (ADDR_EXPR, unknown_type_node, arg);
4345 /* Handle complex lvalues (when permitted)
4346 by reduction to simpler cases. */
4347 val = unary_complex_lvalue (code, arg);
4351 switch (TREE_CODE (arg))
4356 case FIX_TRUNC_EXPR:
4357 if (! lvalue_p (arg) && pedantic)
4358 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4362 arg = BASELINK_FUNCTIONS (arg);
4366 arg = OVL_CURRENT (arg);
4370 /* Turn a reference to a non-static data member into a
4371 pointer-to-member. */
4376 if (!PTRMEM_OK_P (arg))
4377 return build_unary_op (code, arg, 0);
4379 t = TREE_OPERAND (arg, 1);
4380 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4382 error ("cannot create pointer to reference member %qD", t);
4383 return error_mark_node;
4386 type = build_ptrmem_type (context_for_name_lookup (t),
4388 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4396 /* Anything not already handled and not a true memory reference
4398 if (TREE_CODE (argtype) != FUNCTION_TYPE
4399 && TREE_CODE (argtype) != METHOD_TYPE
4400 && TREE_CODE (arg) != OFFSET_REF
4401 && !lvalue_or_else (arg, lv_addressof))
4402 return error_mark_node;
4404 if (argtype != error_mark_node)
4405 argtype = build_pointer_type (argtype);
4407 /* In a template, we are processing a non-dependent expression
4408 so we can just form an ADDR_EXPR with the correct type. */
4409 if (processing_template_decl)
4411 val = build_address (arg);
4412 if (TREE_CODE (arg) == OFFSET_REF)
4413 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4417 if (TREE_CODE (arg) != COMPONENT_REF)
4419 val = build_address (arg);
4420 if (TREE_CODE (arg) == OFFSET_REF)
4421 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4423 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4425 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4427 /* We can only get here with a single static member
4429 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4430 && DECL_STATIC_FUNCTION_P (fn));
4432 val = build_address (fn);
4433 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4434 /* Do not lose object's side effects. */
4435 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4436 TREE_OPERAND (arg, 0), val);
4438 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4440 error ("attempt to take address of bit-field structure member %qD",
4441 TREE_OPERAND (arg, 1));
4442 return error_mark_node;
4446 tree object = TREE_OPERAND (arg, 0);
4447 tree field = TREE_OPERAND (arg, 1);
4448 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4449 (TREE_TYPE (object), decl_type_context (field)));
4450 val = build_address (arg);
4453 if (TREE_CODE (argtype) == POINTER_TYPE
4454 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4456 build_ptrmemfunc_type (argtype);
4457 val = build_ptrmemfunc (argtype, val, 0,
4458 /*c_cast_p=*/false);
4470 argtype = TREE_TYPE (arg);
4471 return fold_if_not_in_template (build1 (code, argtype, arg));
4474 error ("%s", errstring);
4475 return error_mark_node;
4478 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4479 for certain kinds of expressions which are not really lvalues
4480 but which we can accept as lvalues.
4482 If ARG is not a kind of expression we can handle, return
4486 unary_complex_lvalue (enum tree_code code, tree arg)
4488 /* Inside a template, making these kinds of adjustments is
4489 pointless; we are only concerned with the type of the
4491 if (processing_template_decl)
4494 /* Handle (a, b) used as an "lvalue". */
4495 if (TREE_CODE (arg) == COMPOUND_EXPR)
4497 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4498 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4499 TREE_OPERAND (arg, 0), real_result);
4502 /* Handle (a ? b : c) used as an "lvalue". */
4503 if (TREE_CODE (arg) == COND_EXPR
4504 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4505 return rationalize_conditional_expr (code, arg);
4507 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4508 if (TREE_CODE (arg) == MODIFY_EXPR
4509 || TREE_CODE (arg) == PREINCREMENT_EXPR
4510 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4512 tree lvalue = TREE_OPERAND (arg, 0);
4513 if (TREE_SIDE_EFFECTS (lvalue))
4515 lvalue = stabilize_reference (lvalue);
4516 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4517 lvalue, TREE_OPERAND (arg, 1));
4519 return unary_complex_lvalue
4520 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4523 if (code != ADDR_EXPR)
4526 /* Handle (a = b) used as an "lvalue" for `&'. */
4527 if (TREE_CODE (arg) == MODIFY_EXPR
4528 || TREE_CODE (arg) == INIT_EXPR)
4530 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4531 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4533 TREE_NO_WARNING (arg) = 1;
4537 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4538 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4539 || TREE_CODE (arg) == OFFSET_REF)
4542 /* We permit compiler to make function calls returning
4543 objects of aggregate type look like lvalues. */
4547 if (TREE_CODE (targ) == SAVE_EXPR)
4548 targ = TREE_OPERAND (targ, 0);
4550 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4552 if (TREE_CODE (arg) == SAVE_EXPR)
4555 targ = build_cplus_new (TREE_TYPE (arg), arg);
4556 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4559 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4560 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4561 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4564 /* Don't let anything else be handled specially. */
4568 /* Mark EXP saying that we need to be able to take the
4569 address of it; it should not be allocated in a register.
4570 Value is true if successful.
4572 C++: we do not allow `current_class_ptr' to be addressable. */
4575 cxx_mark_addressable (tree exp)
4580 switch (TREE_CODE (x))
4587 x = TREE_OPERAND (x, 0);
4591 if (x == current_class_ptr)
4593 error ("cannot take the address of %<this%>, which is an rvalue expression");
4594 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4600 /* Caller should not be trying to mark initialized
4601 constant fields addressable. */
4602 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4603 || DECL_IN_AGGR_P (x) == 0
4605 || DECL_EXTERNAL (x));
4610 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4611 && !DECL_ARTIFICIAL (x))
4613 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4616 ("address of explicit register variable %qD requested", x);
4619 else if (extra_warnings)
4621 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4623 TREE_ADDRESSABLE (x) = 1;
4627 TREE_ADDRESSABLE (x) = 1;
4631 TREE_ADDRESSABLE (x) = 1;
4635 TREE_ADDRESSABLE (x) = 1;
4636 cxx_mark_addressable (TREE_OPERAND (x, 0));
4644 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4647 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4649 tree orig_ifexp = ifexp;
4650 tree orig_op1 = op1;
4651 tree orig_op2 = op2;
4654 if (processing_template_decl)
4656 /* The standard says that the expression is type-dependent if
4657 IFEXP is type-dependent, even though the eventual type of the
4658 expression doesn't dependent on IFEXP. */
4659 if (type_dependent_expression_p (ifexp)
4660 /* As a GNU extension, the middle operand may be omitted. */
4661 || (op1 && type_dependent_expression_p (op1))
4662 || type_dependent_expression_p (op2))
4663 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4664 ifexp = build_non_dependent_expr (ifexp);
4666 op1 = build_non_dependent_expr (op1);
4667 op2 = build_non_dependent_expr (op2);
4670 expr = build_conditional_expr (ifexp, op1, op2);
4671 if (processing_template_decl && expr != error_mark_node)
4672 return build_min_non_dep (COND_EXPR, expr,
4673 orig_ifexp, orig_op1, orig_op2);
4677 /* Given a list of expressions, return a compound expression
4678 that performs them all and returns the value of the last of them. */
4680 tree build_x_compound_expr_from_list (tree list, const char *msg)
4682 tree expr = TREE_VALUE (list);
4684 if (TREE_CHAIN (list))
4687 pedwarn ("%s expression list treated as compound expression", msg);
4689 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4690 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4696 /* Handle overloading of the ',' operator when needed. */
4699 build_x_compound_expr (tree op1, tree op2)
4702 tree orig_op1 = op1;
4703 tree orig_op2 = op2;
4705 if (processing_template_decl)
4707 if (type_dependent_expression_p (op1)
4708 || type_dependent_expression_p (op2))
4709 return build_min_nt (COMPOUND_EXPR, op1, op2);
4710 op1 = build_non_dependent_expr (op1);
4711 op2 = build_non_dependent_expr (op2);
4714 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4715 /*overloaded_p=*/NULL);
4717 result = build_compound_expr (op1, op2);
4719 if (processing_template_decl && result != error_mark_node)
4720 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4725 /* Build a compound expression. */
4728 build_compound_expr (tree lhs, tree rhs)
4730 lhs = convert_to_void (lhs, "left-hand operand of comma");
4732 if (lhs == error_mark_node || rhs == error_mark_node)
4733 return error_mark_node;
4735 if (TREE_CODE (rhs) == TARGET_EXPR)
4737 /* If the rhs is a TARGET_EXPR, then build the compound
4738 expression inside the target_expr's initializer. This
4739 helps the compiler to eliminate unnecessary temporaries. */
4740 tree init = TREE_OPERAND (rhs, 1);
4742 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4743 TREE_OPERAND (rhs, 1) = init;
4748 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4751 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4752 casts away constness. DIAG_FN gives the function to call if we
4753 need to issue a diagnostic; if it is NULL, no diagnostic will be
4754 issued. DESCRIPTION explains what operation is taking place. */
4757 check_for_casting_away_constness (tree src_type, tree dest_type,
4758 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4759 const char *description)
4761 if (diag_fn && casts_away_constness (src_type, dest_type))
4762 diag_fn ("%s from type %qT to type %qT casts away constness",
4763 description, src_type, dest_type);
4766 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4767 (another pointer-to-member type in the same hierarchy) and return
4768 the converted expression. If ALLOW_INVERSE_P is permitted, a
4769 pointer-to-derived may be converted to pointer-to-base; otherwise,
4770 only the other direction is permitted. If C_CAST_P is true, this
4771 conversion is taking place as part of a C-style cast. */
4774 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4777 if (TYPE_PTRMEM_P (type))
4781 if (TREE_CODE (expr) == PTRMEM_CST)
4782 expr = cplus_expand_constant (expr);
4783 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4784 TYPE_PTRMEM_CLASS_TYPE (type),
4787 if (!integer_zerop (delta))
4788 expr = cp_build_binary_op (PLUS_EXPR,
4789 build_nop (ptrdiff_type_node, expr),
4791 return build_nop (type, expr);
4794 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4795 allow_inverse_p, c_cast_p);
4798 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4799 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4800 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4803 ignore_overflows (tree expr, tree orig)
4805 if (TREE_CODE (expr) == INTEGER_CST
4806 && CONSTANT_CLASS_P (orig)
4807 && TREE_CODE (orig) != STRING_CST
4808 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4809 || TREE_CONSTANT_OVERFLOW (expr)
4810 != TREE_CONSTANT_OVERFLOW (orig)))
4812 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4813 /* Ensure constant sharing. */
4814 expr = build_int_cst_wide (TREE_TYPE (expr),
4815 TREE_INT_CST_LOW (expr),
4816 TREE_INT_CST_HIGH (expr));
4819 /* Avoid clobbering a shared constant. */
4820 expr = copy_node (expr);
4821 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4822 TREE_CONSTANT_OVERFLOW (expr)
4823 = TREE_CONSTANT_OVERFLOW (orig);
4829 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4830 this static_cast is being attempted as one of the possible casts
4831 allowed by a C-style cast. (In that case, accessibility of base
4832 classes is not considered, and it is OK to cast away
4833 constness.) Return the result of the cast. *VALID_P is set to
4834 indicate whether or not the cast was valid. */
4837 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4843 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4846 /* Assume the cast is valid. */
4849 intype = TREE_TYPE (expr);
4851 /* Save casted types in the function's used types hash table. */
4852 used_types_insert (type);
4854 /* Determine what to do when casting away constness. */
4857 /* C-style casts are allowed to cast away constness. With
4858 WARN_CAST_QUAL, we still want to issue a warning. */
4859 diag_fn = warn_cast_qual ? warning0 : NULL;
4864 /* A static_cast may not cast away constness. */
4866 desc = "static_cast";
4869 /* [expr.static.cast]
4871 An lvalue of type "cv1 B", where B is a class type, can be cast
4872 to type "reference to cv2 D", where D is a class derived (clause
4873 _class.derived_) from B, if a valid standard conversion from
4874 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4875 same cv-qualification as, or greater cv-qualification than, cv1,
4876 and B is not a virtual base class of D. */
4877 /* We check this case before checking the validity of "TYPE t =
4878 EXPR;" below because for this case:
4881 struct D : public B { D(const B&); };
4883 void f() { static_cast<const D&>(b); }
4885 we want to avoid constructing a new D. The standard is not
4886 completely clear about this issue, but our interpretation is
4887 consistent with other compilers. */
4888 if (TREE_CODE (type) == REFERENCE_TYPE
4889 && CLASS_TYPE_P (TREE_TYPE (type))
4890 && CLASS_TYPE_P (intype)
4891 && real_lvalue_p (expr)
4892 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4893 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4894 build_pointer_type (TYPE_MAIN_VARIANT
4895 (TREE_TYPE (type))))
4897 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4901 /* There is a standard conversion from "D*" to "B*" even if "B"
4902 is ambiguous or inaccessible. If this is really a
4903 static_cast, then we check both for inaccessibility and
4904 ambiguity. However, if this is a static_cast being performed
4905 because the user wrote a C-style cast, then accessibility is
4907 base = lookup_base (TREE_TYPE (type), intype,
4908 c_cast_p ? ba_unique : ba_check,
4911 /* Convert from "B*" to "D*". This function will check that "B"
4912 is not a virtual base of "D". */
4913 expr = build_base_path (MINUS_EXPR, build_address (expr),
4914 base, /*nonnull=*/false);
4915 /* Convert the pointer to a reference -- but then remember that
4916 there are no expressions with reference type in C++. */
4917 return convert_from_reference (build_nop (type, expr));
4922 /* [expr.static.cast]
4924 An expression e can be explicitly converted to a type T using a
4925 static_cast of the form static_cast<T>(e) if the declaration T
4926 t(e);" is well-formed, for some invented temporary variable
4928 result = perform_direct_initialization_if_possible (type, expr,
4932 result = convert_from_reference (result);
4934 /* Ignore any integer overflow caused by the cast. */
4935 result = ignore_overflows (result, orig);
4937 /* [expr.static.cast]
4939 If T is a reference type, the result is an lvalue; otherwise,
4940 the result is an rvalue. */
4941 if (TREE_CODE (type) != REFERENCE_TYPE)
4942 result = rvalue (result);
4946 /* [expr.static.cast]
4948 Any expression can be explicitly converted to type cv void. */
4949 if (TREE_CODE (type) == VOID_TYPE)
4950 return convert_to_void (expr, /*implicit=*/NULL);
4952 /* [expr.static.cast]
4954 The inverse of any standard conversion sequence (clause _conv_),
4955 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4956 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4957 (_conv.bool_) conversions, can be performed explicitly using
4958 static_cast subject to the restriction that the explicit
4959 conversion does not cast away constness (_expr.const.cast_), and
4960 the following additional rules for specific cases: */
4961 /* For reference, the conversions not excluded are: integral
4962 promotions, floating point promotion, integral conversions,
4963 floating point conversions, floating-integral conversions,
4964 pointer conversions, and pointer to member conversions. */
4967 A value of integral _or enumeration_ type can be explicitly
4968 converted to an enumeration type. */
4969 /* The effect of all that is that any conversion between any two
4970 types which are integral, floating, or enumeration types can be
4972 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4973 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4975 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4977 /* Ignore any integer overflow caused by the cast. */
4978 expr = ignore_overflows (expr, orig);
4982 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4983 && CLASS_TYPE_P (TREE_TYPE (type))
4984 && CLASS_TYPE_P (TREE_TYPE (intype))
4985 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4986 (TREE_TYPE (intype))),
4987 build_pointer_type (TYPE_MAIN_VARIANT
4988 (TREE_TYPE (type)))))
4993 check_for_casting_away_constness (intype, type, diag_fn, desc);
4994 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4995 c_cast_p ? ba_unique : ba_check,
4997 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5000 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5001 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5008 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5009 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5011 if (TYPE_PTRMEM_P (type))
5013 t1 = (build_ptrmem_type
5015 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5016 t2 = (build_ptrmem_type
5018 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5025 if (can_convert (t1, t2))
5028 check_for_casting_away_constness (intype, type, diag_fn,
5030 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5035 /* [expr.static.cast]
5037 An rvalue of type "pointer to cv void" can be explicitly
5038 converted to a pointer to object type. A value of type pointer
5039 to object converted to "pointer to cv void" and back to the
5040 original pointer type will have its original value. */
5041 if (TREE_CODE (intype) == POINTER_TYPE
5042 && VOID_TYPE_P (TREE_TYPE (intype))
5043 && TYPE_PTROB_P (type))
5046 check_for_casting_away_constness (intype, type, diag_fn, desc);
5047 return build_nop (type, expr);
5051 return error_mark_node;
5054 /* Return an expression representing static_cast<TYPE>(EXPR). */
5057 build_static_cast (tree type, tree expr)
5062 if (type == error_mark_node || expr == error_mark_node)
5063 return error_mark_node;
5065 if (processing_template_decl)
5067 expr = build_min (STATIC_CAST_EXPR, type, expr);
5068 /* We don't know if it will or will not have side effects. */
5069 TREE_SIDE_EFFECTS (expr) = 1;
5070 return convert_from_reference (expr);
5073 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5074 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5075 if (TREE_CODE (type) != REFERENCE_TYPE
5076 && TREE_CODE (expr) == NOP_EXPR
5077 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5078 expr = TREE_OPERAND (expr, 0);
5080 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5084 error ("invalid static_cast from type %qT to type %qT",
5085 TREE_TYPE (expr), type);
5086 return error_mark_node;
5089 /* EXPR is an expression with member function or pointer-to-member
5090 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5091 not permitted by ISO C++, but we accept it in some modes. If we
5092 are not in one of those modes, issue a diagnostic. Return the
5093 converted expression. */
5096 convert_member_func_to_ptr (tree type, tree expr)
5101 intype = TREE_TYPE (expr);
5102 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5103 || TREE_CODE (intype) == METHOD_TYPE);
5105 if (pedantic || warn_pmf2ptr)
5106 pedwarn ("converting from %qT to %qT", intype, type);
5108 if (TREE_CODE (intype) == METHOD_TYPE)
5109 expr = build_addr_func (expr);
5110 else if (TREE_CODE (expr) == PTRMEM_CST)
5111 expr = build_address (PTRMEM_CST_MEMBER (expr));
5114 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5115 decl = build_address (decl);
5116 expr = get_member_function_from_ptrfunc (&decl, expr);
5119 return build_nop (type, expr);
5122 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5123 If C_CAST_P is true, this reinterpret cast is being done as part of
5124 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5125 indicate whether or not reinterpret_cast was valid. */
5128 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5133 /* Assume the cast is invalid. */
5137 if (type == error_mark_node || error_operand_p (expr))
5138 return error_mark_node;
5140 intype = TREE_TYPE (expr);
5142 /* Save casted types in the function's used types hash table. */
5143 used_types_insert (type);
5145 /* [expr.reinterpret.cast]
5146 An lvalue expression of type T1 can be cast to the type
5147 "reference to T2" if an expression of type "pointer to T1" can be
5148 explicitly converted to the type "pointer to T2" using a
5149 reinterpret_cast. */
5150 if (TREE_CODE (type) == REFERENCE_TYPE)
5152 if (! real_lvalue_p (expr))
5154 error ("invalid cast of an rvalue expression of type "
5157 return error_mark_node;
5160 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5161 "B" are related class types; the reinterpret_cast does not
5162 adjust the pointer. */
5163 if (TYPE_PTR_P (intype)
5164 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5165 COMPARE_BASE | COMPARE_DERIVED)))
5166 warning (0, "casting %qT to %qT does not dereference pointer",
5169 expr = build_unary_op (ADDR_EXPR, expr, 0);
5170 if (expr != error_mark_node)
5171 expr = build_reinterpret_cast_1
5172 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5174 if (expr != error_mark_node)
5175 expr = build_indirect_ref (expr, 0);
5179 /* As a G++ extension, we consider conversions from member
5180 functions, and pointers to member functions to
5181 pointer-to-function and pointer-to-void types. If
5182 -Wno-pmf-conversions has not been specified,
5183 convert_member_func_to_ptr will issue an error message. */
5184 if ((TYPE_PTRMEMFUNC_P (intype)
5185 || TREE_CODE (intype) == METHOD_TYPE)
5186 && TYPE_PTR_P (type)
5187 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5188 || VOID_TYPE_P (TREE_TYPE (type))))
5189 return convert_member_func_to_ptr (type, expr);
5191 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5192 array-to-pointer, and function-to-pointer conversions are
5194 expr = decay_conversion (expr);
5196 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5197 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5198 if (TREE_CODE (expr) == NOP_EXPR
5199 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5200 expr = TREE_OPERAND (expr, 0);
5202 if (error_operand_p (expr))
5203 return error_mark_node;
5205 intype = TREE_TYPE (expr);
5207 /* [expr.reinterpret.cast]
5208 A pointer can be converted to any integral type large enough to
5210 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5212 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5213 pedwarn ("cast from %qT to %qT loses precision",
5216 /* [expr.reinterpret.cast]
5217 A value of integral or enumeration type can be explicitly
5218 converted to a pointer. */
5219 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5222 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5223 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5224 return fold_if_not_in_template (build_nop (type, expr));
5225 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5226 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5231 check_for_casting_away_constness (intype, type, error,
5232 "reinterpret_cast");
5233 /* Warn about possible alignment problems. */
5234 if (STRICT_ALIGNMENT && warn_cast_align
5235 && !VOID_TYPE_P (type)
5236 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5237 && COMPLETE_TYPE_P (TREE_TYPE (type))
5238 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5239 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5240 warning (0, "cast from %qT to %qT increases required alignment of "
5244 /* We need to strip nops here, because the frontend likes to
5245 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5247 strict_aliasing_warning (intype, type, sexpr);
5249 return fold_if_not_in_template (build_nop (type, expr));
5251 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5252 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5255 /* Only issue a warning, as we have always supported this
5256 where possible, and it is necessary in some cases. DR 195
5257 addresses this issue, but as of 2004/10/26 is still in
5259 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5260 return fold_if_not_in_template (build_nop (type, expr));
5262 else if (TREE_CODE (type) == VECTOR_TYPE)
5263 return fold_if_not_in_template (convert_to_vector (type, expr));
5264 else if (TREE_CODE (intype) == VECTOR_TYPE)
5265 return fold_if_not_in_template (convert_to_integer (type, expr));
5270 error ("invalid cast from type %qT to type %qT", intype, type);
5271 return error_mark_node;
5274 return cp_convert (type, expr);
5278 build_reinterpret_cast (tree type, tree expr)
5280 if (type == error_mark_node || expr == error_mark_node)
5281 return error_mark_node;
5283 if (processing_template_decl)
5285 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5287 if (!TREE_SIDE_EFFECTS (t)
5288 && type_dependent_expression_p (expr))
5289 /* There might turn out to be side effects inside expr. */
5290 TREE_SIDE_EFFECTS (t) = 1;
5291 return convert_from_reference (t);
5294 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5298 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5299 return an appropriate expression. Otherwise, return
5300 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5301 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5302 performing a C-style cast, its value upon return will indicate
5303 whether or not the conversion succeeded. */
5306 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5310 tree reference_type;
5312 /* Callers are responsible for handling error_mark_node as a
5313 destination type. */
5314 gcc_assert (dst_type != error_mark_node);
5315 /* In a template, callers should be building syntactic
5316 representations of casts, not using this machinery. */
5317 gcc_assert (!processing_template_decl);
5319 /* Assume the conversion is invalid. */
5323 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5326 error ("invalid use of const_cast with type %qT, "
5327 "which is not a pointer, "
5328 "reference, nor a pointer-to-data-member type", dst_type);
5329 return error_mark_node;
5332 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5335 error ("invalid use of const_cast with type %qT, which is a pointer "
5336 "or reference to a function type", dst_type);
5337 return error_mark_node;
5340 /* Save casted types in the function's used types hash table. */
5341 used_types_insert (dst_type);
5343 src_type = TREE_TYPE (expr);
5344 /* Expressions do not really have reference types. */
5345 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5346 src_type = TREE_TYPE (src_type);
5348 /* [expr.const.cast]
5350 An lvalue of type T1 can be explicitly converted to an lvalue of
5351 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5352 types) if a pointer to T1 can be explicitly converted to the type
5353 pointer to T2 using a const_cast. */
5354 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5356 reference_type = dst_type;
5357 if (! real_lvalue_p (expr))
5360 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5361 src_type, dst_type);
5362 return error_mark_node;
5364 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5365 src_type = build_pointer_type (src_type);
5369 reference_type = NULL_TREE;
5370 /* If the destination type is not a reference type, the
5371 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5372 conversions are performed. */
5373 src_type = type_decays_to (src_type);
5374 if (src_type == error_mark_node)
5375 return error_mark_node;
5378 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5379 && comp_ptr_ttypes_const (dst_type, src_type))
5384 /* This cast is actually a C-style cast. Issue a warning if
5385 the user is making a potentially unsafe cast. */
5387 check_for_casting_away_constness (src_type, dst_type,
5393 expr = build_unary_op (ADDR_EXPR, expr, 0);
5394 expr = build_nop (reference_type, expr);
5395 return convert_from_reference (expr);
5399 expr = decay_conversion (expr);
5400 /* build_c_cast puts on a NOP_EXPR to make the result not an
5401 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5402 non-lvalue context. */
5403 if (TREE_CODE (expr) == NOP_EXPR
5404 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5405 expr = TREE_OPERAND (expr, 0);
5406 return build_nop (dst_type, expr);
5411 error ("invalid const_cast from type %qT to type %qT",
5412 src_type, dst_type);
5413 return error_mark_node;
5417 build_const_cast (tree type, tree expr)
5419 if (type == error_mark_node || error_operand_p (expr))
5420 return error_mark_node;
5422 if (processing_template_decl)
5424 tree t = build_min (CONST_CAST_EXPR, type, expr);
5426 if (!TREE_SIDE_EFFECTS (t)
5427 && type_dependent_expression_p (expr))
5428 /* There might turn out to be side effects inside expr. */
5429 TREE_SIDE_EFFECTS (t) = 1;
5430 return convert_from_reference (t);
5433 return build_const_cast_1 (type, expr, /*complain=*/true,
5437 /* Build an expression representing an explicit C-style cast to type
5438 TYPE of expression EXPR. */
5441 build_c_cast (tree type, tree expr)
5447 if (type == error_mark_node || error_operand_p (expr))
5448 return error_mark_node;
5450 if (processing_template_decl)
5452 tree t = build_min (CAST_EXPR, type,
5453 tree_cons (NULL_TREE, value, NULL_TREE));
5454 /* We don't know if it will or will not have side effects. */
5455 TREE_SIDE_EFFECTS (t) = 1;
5456 return convert_from_reference (t);
5459 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5460 'Class') should always be retained, because this information aids
5461 in method lookup. */
5462 if (objc_is_object_ptr (type)
5463 && objc_is_object_ptr (TREE_TYPE (expr)))
5464 return build_nop (type, expr);
5466 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5467 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5468 if (TREE_CODE (type) != REFERENCE_TYPE
5469 && TREE_CODE (value) == NOP_EXPR
5470 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5471 value = TREE_OPERAND (value, 0);
5473 if (TREE_CODE (type) == ARRAY_TYPE)
5475 /* Allow casting from T1* to T2[] because Cfront allows it.
5476 NIHCL uses it. It is not valid ISO C++ however. */
5477 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5479 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5480 type = build_pointer_type (TREE_TYPE (type));
5484 error ("ISO C++ forbids casting to an array type %qT", type);
5485 return error_mark_node;
5489 if (TREE_CODE (type) == FUNCTION_TYPE
5490 || TREE_CODE (type) == METHOD_TYPE)
5492 error ("invalid cast to function type %qT", type);
5493 return error_mark_node;
5496 /* A C-style cast can be a const_cast. */
5497 result = build_const_cast_1 (type, value, /*complain=*/false,
5502 /* Or a static cast. */
5503 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5505 /* Or a reinterpret_cast. */
5507 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5509 /* The static_cast or reinterpret_cast may be followed by a
5512 /* A valid cast may result in errors if, for example, a
5513 conversion to am ambiguous base class is required. */
5514 && !error_operand_p (result))
5518 /* Non-class rvalues always have cv-unqualified type. */
5519 if (!CLASS_TYPE_P (type))
5520 type = TYPE_MAIN_VARIANT (type);
5521 result_type = TREE_TYPE (result);
5522 if (!CLASS_TYPE_P (result_type))
5523 result_type = TYPE_MAIN_VARIANT (result_type);
5524 /* If the type of RESULT does not match TYPE, perform a
5525 const_cast to make it match. If the static_cast or
5526 reinterpret_cast succeeded, we will differ by at most
5527 cv-qualification, so the follow-on const_cast is guaranteed
5529 if (!same_type_p (non_reference (type), non_reference (result_type)))
5531 result = build_const_cast_1 (type, result, false, &valid_p);
5532 gcc_assert (valid_p);
5537 return error_mark_node;
5540 /* Build an assignment expression of lvalue LHS from value RHS.
5541 MODIFYCODE is the code for a binary operator that we use
5542 to combine the old value of LHS with RHS to get the new value.
5543 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5545 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5548 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5552 tree lhstype = TREE_TYPE (lhs);
5553 tree olhstype = lhstype;
5554 tree olhs = NULL_TREE;
5555 bool plain_assign = (modifycode == NOP_EXPR);
5557 /* Avoid duplicate error messages from operands that had errors. */
5558 if (error_operand_p (lhs) || error_operand_p (rhs))
5559 return error_mark_node;
5561 /* Handle control structure constructs used as "lvalues". */
5562 switch (TREE_CODE (lhs))
5564 /* Handle --foo = 5; as these are valid constructs in C++. */
5565 case PREDECREMENT_EXPR:
5566 case PREINCREMENT_EXPR:
5567 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5568 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5569 stabilize_reference (TREE_OPERAND (lhs, 0)),
5570 TREE_OPERAND (lhs, 1));
5571 return build2 (COMPOUND_EXPR, lhstype,
5573 build_modify_expr (TREE_OPERAND (lhs, 0),
5576 /* Handle (a, b) used as an "lvalue". */
5578 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5580 if (newrhs == error_mark_node)
5581 return error_mark_node;
5582 return build2 (COMPOUND_EXPR, lhstype,
5583 TREE_OPERAND (lhs, 0), newrhs);
5586 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5587 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5588 stabilize_reference (TREE_OPERAND (lhs, 0)),
5589 TREE_OPERAND (lhs, 1));
5590 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5591 if (newrhs == error_mark_node)
5592 return error_mark_node;
5593 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5597 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5598 when neither operand has side-effects. */
5599 if (!lvalue_or_else (lhs, lv_assign))
5600 return error_mark_node;
5602 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5603 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5605 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5606 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5608 TREE_OPERAND (lhs, 0),
5609 TREE_OPERAND (lhs, 1)),
5610 TREE_OPERAND (lhs, 0),
5611 TREE_OPERAND (lhs, 1));
5614 /* Handle (a ? b : c) used as an "lvalue". */
5617 /* Produce (a ? (b = rhs) : (c = rhs))
5618 except that the RHS goes through a save-expr
5619 so the code to compute it is only emitted once. */
5621 tree preeval = NULL_TREE;
5623 rhs = stabilize_expr (rhs, &preeval);
5625 /* Check this here to avoid odd errors when trying to convert
5626 a throw to the type of the COND_EXPR. */
5627 if (!lvalue_or_else (lhs, lv_assign))
5628 return error_mark_node;
5630 cond = build_conditional_expr
5631 (TREE_OPERAND (lhs, 0),
5632 build_modify_expr (TREE_OPERAND (lhs, 1),
5634 build_modify_expr (TREE_OPERAND (lhs, 2),
5637 if (cond == error_mark_node)
5639 /* Make sure the code to compute the rhs comes out
5640 before the split. */
5642 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5650 if (modifycode == INIT_EXPR)
5652 if (TREE_CODE (rhs) == CONSTRUCTOR)
5654 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5655 /* Call convert to generate an error; see PR 11063. */
5656 rhs = convert (lhstype, rhs);
5657 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5658 TREE_SIDE_EFFECTS (result) = 1;
5661 else if (! IS_AGGR_TYPE (lhstype))
5662 /* Do the default thing. */;
5665 result = build_special_member_call (lhs, complete_ctor_identifier,
5666 build_tree_list (NULL_TREE, rhs),
5667 lhstype, LOOKUP_NORMAL);
5668 if (result == NULL_TREE)
5669 return error_mark_node;
5675 lhs = require_complete_type (lhs);
5676 if (lhs == error_mark_node)
5677 return error_mark_node;
5679 if (modifycode == NOP_EXPR)
5681 /* `operator=' is not an inheritable operator. */
5682 if (! IS_AGGR_TYPE (lhstype))
5683 /* Do the default thing. */;
5686 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5687 lhs, rhs, make_node (NOP_EXPR),
5688 /*overloaded_p=*/NULL);
5689 if (result == NULL_TREE)
5690 return error_mark_node;
5697 /* A binary op has been requested. Combine the old LHS
5698 value with the RHS producing the value we should actually
5699 store into the LHS. */
5701 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5702 lhs = stabilize_reference (lhs);
5703 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5704 if (newrhs == error_mark_node)
5706 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5707 TREE_TYPE (lhs), TREE_TYPE (rhs));
5708 return error_mark_node;
5711 /* Now it looks like a plain assignment. */
5712 modifycode = NOP_EXPR;
5714 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5715 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5718 /* The left-hand side must be an lvalue. */
5719 if (!lvalue_or_else (lhs, lv_assign))
5720 return error_mark_node;
5722 /* Warn about modifying something that is `const'. Don't warn if
5723 this is initialization. */
5724 if (modifycode != INIT_EXPR
5725 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5726 /* Functions are not modifiable, even though they are
5728 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5729 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5730 /* If it's an aggregate and any field is const, then it is
5731 effectively const. */
5732 || (CLASS_TYPE_P (lhstype)
5733 && C_TYPE_FIELDS_READONLY (lhstype))))
5734 readonly_error (lhs, "assignment", 0);
5736 /* If storing into a structure or union member, it has probably been
5737 given type `int'. Compute the type that would go with the actual
5738 amount of storage the member occupies. */
5740 if (TREE_CODE (lhs) == COMPONENT_REF
5741 && (TREE_CODE (lhstype) == INTEGER_TYPE
5742 || TREE_CODE (lhstype) == REAL_TYPE
5743 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5745 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5747 /* If storing in a field that is in actuality a short or narrower
5748 than one, we must store in the field in its actual type. */
5750 if (lhstype != TREE_TYPE (lhs))
5752 /* Avoid warnings converting integral types back into enums for
5754 if (TREE_CODE (lhstype) == INTEGER_TYPE
5755 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5757 if (TREE_SIDE_EFFECTS (lhs))
5758 lhs = stabilize_reference (lhs);
5761 lhs = copy_node (lhs);
5762 TREE_TYPE (lhs) = lhstype;
5766 /* Convert new value to destination type. */
5768 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5772 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5773 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5775 error ("incompatible types in assignment of %qT to %qT",
5776 TREE_TYPE (rhs), lhstype);
5777 return error_mark_node;
5780 /* Allow array assignment in compiler-generated code. */
5781 if (! DECL_ARTIFICIAL (current_function_decl))
5783 /* This routine is used for both initialization and assignment.
5784 Make sure the diagnostic message differentiates the context. */
5785 if (modifycode == INIT_EXPR)
5786 error ("array used as initializer");
5788 error ("invalid array assignment");
5789 return error_mark_node;
5792 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5793 ? 1 + (modifycode != INIT_EXPR): 0;
5794 return build_vec_init (lhs, NULL_TREE, newrhs,
5795 /*explicit_default_init_p=*/false,
5799 if (modifycode == INIT_EXPR)
5800 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5801 "initialization", NULL_TREE, 0);
5804 /* Avoid warnings on enum bit fields. */
5805 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5806 && TREE_CODE (lhstype) == INTEGER_TYPE)
5808 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5810 newrhs = convert_force (lhstype, newrhs, 0);
5813 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5815 if (TREE_CODE (newrhs) == CALL_EXPR
5816 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5817 newrhs = build_cplus_new (lhstype, newrhs);
5819 /* Can't initialize directly from a TARGET_EXPR, since that would
5820 cause the lhs to be constructed twice, and possibly result in
5821 accidental self-initialization. So we force the TARGET_EXPR to be
5822 expanded without a target. */
5823 if (TREE_CODE (newrhs) == TARGET_EXPR)
5824 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5825 TREE_OPERAND (newrhs, 0));
5828 if (newrhs == error_mark_node)
5829 return error_mark_node;
5831 if (c_dialect_objc () && flag_objc_gc)
5833 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5839 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5840 lhstype, lhs, newrhs);
5842 TREE_SIDE_EFFECTS (result) = 1;
5844 TREE_NO_WARNING (result) = 1;
5846 /* If we got the LHS in a different type for storing in,
5847 convert the result back to the nominal type of LHS
5848 so that the value we return always has the same type
5849 as the LHS argument. */
5851 if (olhstype == TREE_TYPE (result))
5855 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5856 TREE_NO_WARNING (result) = 1;
5859 return convert_for_assignment (olhstype, result, "assignment",
5864 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5866 if (processing_template_decl)
5867 return build_min_nt (MODOP_EXPR, lhs,
5868 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5870 if (modifycode != NOP_EXPR)
5872 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5873 make_node (modifycode),
5874 /*overloaded_p=*/NULL);
5877 TREE_NO_WARNING (rval) = 1;
5881 return build_modify_expr (lhs, modifycode, rhs);
5885 /* Get difference in deltas for different pointer to member function
5886 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5887 the conversion is invalid, the constant is zero. If
5888 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5889 If C_CAST_P is true this conversion is taking place as part of a
5892 Note that the naming of FROM and TO is kind of backwards; the return
5893 value is what we add to a TO in order to get a FROM. They are named
5894 this way because we call this function to find out how to convert from
5895 a pointer to member of FROM to a pointer to member of TO. */
5898 get_delta_difference (tree from, tree to,
5899 bool allow_inverse_p,
5906 /* Assume no conversion is required. */
5907 result = integer_zero_node;
5908 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5909 if (kind == bk_inaccessible || kind == bk_ambig)
5910 error (" in pointer to member function conversion");
5913 if (kind != bk_via_virtual)
5914 result = BINFO_OFFSET (binfo);
5917 tree virt_binfo = binfo_from_vbase (binfo);
5919 /* This is a reinterpret cast, we choose to do nothing. */
5920 if (allow_inverse_p)
5921 warning (0, "pointer to member cast via virtual base %qT",
5922 BINFO_TYPE (virt_binfo));
5924 error ("pointer to member conversion via virtual base %qT",
5925 BINFO_TYPE (virt_binfo));
5928 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5929 /* Pointer to member of incomplete class is permitted*/;
5930 else if (!allow_inverse_p)
5932 error_not_base_type (from, to);
5933 error (" in pointer to member conversion");
5937 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5940 if (kind != bk_via_virtual)
5941 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5944 /* This is a reinterpret cast, we choose to do nothing. */
5945 tree virt_binfo = binfo_from_vbase (binfo);
5947 warning (0, "pointer to member cast via virtual base %qT",
5948 BINFO_TYPE (virt_binfo));
5953 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5957 /* Return a constructor for the pointer-to-member-function TYPE using
5958 the other components as specified. */
5961 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5966 VEC(constructor_elt, gc) *v;
5968 /* Pull the FIELD_DECLs out of the type. */
5969 pfn_field = TYPE_FIELDS (type);
5970 delta_field = TREE_CHAIN (pfn_field);
5972 /* Make sure DELTA has the type we want. */
5973 delta = convert_and_check (delta_type_node, delta);
5975 /* Finish creating the initializer. */
5976 v = VEC_alloc(constructor_elt, gc, 2);
5977 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
5978 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
5979 u = build_constructor (type, v);
5980 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5981 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5982 TREE_STATIC (u) = (TREE_CONSTANT (u)
5983 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5985 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5990 /* Build a constructor for a pointer to member function. It can be
5991 used to initialize global variables, local variable, or used
5992 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5995 If FORCE is nonzero, then force this conversion, even if
5996 we would rather not do it. Usually set when using an explicit
5997 cast. A C-style cast is being processed iff C_CAST_P is true.
5999 Return error_mark_node, if something goes wrong. */
6002 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6008 if (error_operand_p (pfn))
6009 return error_mark_node;
6011 pfn_type = TREE_TYPE (pfn);
6012 to_type = build_ptrmemfunc_type (type);
6014 /* Handle multiple conversions of pointer to member functions. */
6015 if (TYPE_PTRMEMFUNC_P (pfn_type))
6017 tree delta = NULL_TREE;
6018 tree npfn = NULL_TREE;
6022 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6023 error ("invalid conversion to type %qT from type %qT",
6026 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6027 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6031 /* We don't have to do any conversion to convert a
6032 pointer-to-member to its own type. But, we don't want to
6033 just return a PTRMEM_CST if there's an explicit cast; that
6034 cast should make the expression an invalid template argument. */
6035 if (TREE_CODE (pfn) != PTRMEM_CST)
6037 if (same_type_p (to_type, pfn_type))
6039 else if (integer_zerop (n))
6040 return build_reinterpret_cast (to_type, pfn);
6043 if (TREE_SIDE_EFFECTS (pfn))
6044 pfn = save_expr (pfn);
6046 /* Obtain the function pointer and the current DELTA. */
6047 if (TREE_CODE (pfn) == PTRMEM_CST)
6048 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6051 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6052 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6055 /* Just adjust the DELTA field. */
6056 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6057 (TREE_TYPE (delta), ptrdiff_type_node));
6058 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6059 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6060 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6061 return build_ptrmemfunc1 (to_type, delta, npfn);
6064 /* Handle null pointer to member function conversions. */
6065 if (integer_zerop (pfn))
6067 pfn = build_c_cast (type, integer_zero_node);
6068 return build_ptrmemfunc1 (to_type,
6073 if (type_unknown_p (pfn))
6074 return instantiate_type (type, pfn, tf_warning_or_error);
6076 fn = TREE_OPERAND (pfn, 0);
6077 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6078 /* In a template, we will have preserved the
6080 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6081 return make_ptrmem_cst (to_type, fn);
6084 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6087 ??? There is no consistency as to the types returned for the above
6088 values. Some code acts as if it were a sizetype and some as if it were
6089 integer_type_node. */
6092 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6094 tree type = TREE_TYPE (cst);
6095 tree fn = PTRMEM_CST_MEMBER (cst);
6096 tree ptr_class, fn_class;
6098 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6100 /* The class that the function belongs to. */
6101 fn_class = DECL_CONTEXT (fn);
6103 /* The class that we're creating a pointer to member of. */
6104 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6106 /* First, calculate the adjustment to the function's class. */
6107 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6110 if (!DECL_VIRTUAL_P (fn))
6111 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6114 /* If we're dealing with a virtual function, we have to adjust 'this'
6115 again, to point to the base which provides the vtable entry for
6116 fn; the call will do the opposite adjustment. */
6117 tree orig_class = DECL_CONTEXT (fn);
6118 tree binfo = binfo_or_else (orig_class, fn_class);
6119 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6120 *delta, BINFO_OFFSET (binfo));
6121 *delta = fold_if_not_in_template (*delta);
6123 /* We set PFN to the vtable offset at which the function can be
6124 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6125 case delta is shifted left, and then incremented). */
6126 *pfn = DECL_VINDEX (fn);
6127 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6128 TYPE_SIZE_UNIT (vtable_entry_type));
6129 *pfn = fold_if_not_in_template (*pfn);
6131 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6133 case ptrmemfunc_vbit_in_pfn:
6134 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6136 *pfn = fold_if_not_in_template (*pfn);
6139 case ptrmemfunc_vbit_in_delta:
6140 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6141 *delta, integer_one_node);
6142 *delta = fold_if_not_in_template (*delta);
6143 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6144 *delta, integer_one_node);
6145 *delta = fold_if_not_in_template (*delta);
6152 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6153 *pfn = fold_if_not_in_template (*pfn);
6157 /* Return an expression for PFN from the pointer-to-member function
6161 pfn_from_ptrmemfunc (tree t)
6163 if (TREE_CODE (t) == PTRMEM_CST)
6168 expand_ptrmemfunc_cst (t, &delta, &pfn);
6173 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6176 /* Convert value RHS to type TYPE as preparation for an assignment to
6177 an lvalue of type TYPE. ERRTYPE is a string to use in error
6178 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6179 are doing the conversion in order to pass the PARMNUMth argument of
6183 convert_for_assignment (tree type, tree rhs,
6184 const char *errtype, tree fndecl, int parmnum)
6187 enum tree_code coder;
6189 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6190 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6191 rhs = TREE_OPERAND (rhs, 0);
6193 rhstype = TREE_TYPE (rhs);
6194 coder = TREE_CODE (rhstype);
6196 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6197 && vector_types_convertible_p (type, rhstype))
6198 return convert (type, rhs);
6200 if (rhs == error_mark_node || rhstype == error_mark_node)
6201 return error_mark_node;
6202 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6203 return error_mark_node;
6205 /* The RHS of an assignment cannot have void type. */
6206 if (coder == VOID_TYPE)
6208 error ("void value not ignored as it ought to be");
6209 return error_mark_node;
6212 /* Simplify the RHS if possible. */
6213 if (TREE_CODE (rhs) == CONST_DECL)
6214 rhs = DECL_INITIAL (rhs);
6216 if (c_dialect_objc ())
6219 tree rname = fndecl;
6221 if (!strcmp (errtype, "assignment"))
6223 else if (!strcmp (errtype, "initialization"))
6227 tree selector = objc_message_selector ();
6231 if (selector && parmno > 1)
6238 if (objc_compare_types (type, rhstype, parmno, rname))
6239 return convert (type, rhs);
6244 The expression is implicitly converted (clause _conv_) to the
6245 cv-unqualified type of the left operand.
6247 We allow bad conversions here because by the time we get to this point
6248 we are committed to doing the conversion. If we end up doing a bad
6249 conversion, convert_like will complain. */
6250 if (!can_convert_arg_bad (type, rhstype, rhs))
6252 /* When -Wno-pmf-conversions is use, we just silently allow
6253 conversions from pointers-to-members to plain pointers. If
6254 the conversion doesn't work, cp_convert will complain. */
6256 && TYPE_PTR_P (type)
6257 && TYPE_PTRMEMFUNC_P (rhstype))
6258 rhs = cp_convert (strip_top_quals (type), rhs);
6261 /* If the right-hand side has unknown type, then it is an
6262 overloaded function. Call instantiate_type to get error
6264 if (rhstype == unknown_type_node)
6265 instantiate_type (type, rhs, tf_warning_or_error);
6267 error ("cannot convert %qT to %qT for argument %qP to %qD",
6268 rhstype, type, parmnum, fndecl);
6270 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6271 return error_mark_node;
6274 if (warn_missing_format_attribute)
6276 const enum tree_code codel = TREE_CODE (type);
6277 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6279 && check_missing_format_attribute (type, rhstype))
6280 warning (OPT_Wmissing_format_attribute,
6281 "%s might be a candidate for a format attribute",
6285 return perform_implicit_conversion (strip_top_quals (type), rhs);
6288 /* Convert RHS to be of type TYPE.
6289 If EXP is nonzero, it is the target of the initialization.
6290 ERRTYPE is a string to use in error messages.
6292 Two major differences between the behavior of
6293 `convert_for_assignment' and `convert_for_initialization'
6294 are that references are bashed in the former, while
6295 copied in the latter, and aggregates are assigned in
6296 the former (operator=) while initialized in the
6299 If using constructor make sure no conversion operator exists, if one does
6300 exist, an ambiguity exists.
6302 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6305 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6306 const char *errtype, tree fndecl, int parmnum)
6308 enum tree_code codel = TREE_CODE (type);
6310 enum tree_code coder;
6312 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6313 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6314 if (TREE_CODE (rhs) == NOP_EXPR
6315 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6316 && codel != REFERENCE_TYPE)
6317 rhs = TREE_OPERAND (rhs, 0);
6319 if (type == error_mark_node
6320 || rhs == error_mark_node
6321 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6322 return error_mark_node;
6324 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6325 && TREE_CODE (type) != ARRAY_TYPE
6326 && (TREE_CODE (type) != REFERENCE_TYPE
6327 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6328 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6329 && (TREE_CODE (type) != REFERENCE_TYPE
6330 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6331 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6332 rhs = decay_conversion (rhs);
6334 rhstype = TREE_TYPE (rhs);
6335 coder = TREE_CODE (rhstype);
6337 if (coder == ERROR_MARK)
6338 return error_mark_node;
6340 /* We accept references to incomplete types, so we can
6341 return here before checking if RHS is of complete type. */
6343 if (codel == REFERENCE_TYPE)
6345 /* This should eventually happen in convert_arguments. */
6346 int savew = 0, savee = 0;
6349 savew = warningcount, savee = errorcount;
6350 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6354 if (warningcount > savew)
6355 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6356 else if (errorcount > savee)
6357 error ("in passing argument %P of %q+D", parmnum, fndecl);
6363 exp = require_complete_type (exp);
6364 if (exp == error_mark_node)
6365 return error_mark_node;
6367 rhstype = non_reference (rhstype);
6369 type = complete_type (type);
6371 if (IS_AGGR_TYPE (type))
6372 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6374 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6377 /* If RETVAL is the address of, or a reference to, a local variable or
6378 temporary give an appropriate warning. */
6381 maybe_warn_about_returning_address_of_local (tree retval)
6383 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6384 tree whats_returned = retval;
6388 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6389 whats_returned = TREE_OPERAND (whats_returned, 1);
6390 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6391 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6392 || TREE_CODE (whats_returned) == NOP_EXPR)
6393 whats_returned = TREE_OPERAND (whats_returned, 0);
6398 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6400 whats_returned = TREE_OPERAND (whats_returned, 0);
6402 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6404 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6405 || TREE_CODE (whats_returned) == TARGET_EXPR)
6407 warning (0, "returning reference to temporary");
6410 if (TREE_CODE (whats_returned) == VAR_DECL
6411 && DECL_NAME (whats_returned)
6412 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6414 warning (0, "reference to non-lvalue returned");
6419 while (TREE_CODE (whats_returned) == COMPONENT_REF
6420 || TREE_CODE (whats_returned) == ARRAY_REF)
6421 whats_returned = TREE_OPERAND (whats_returned, 0);
6423 if (DECL_P (whats_returned)
6424 && DECL_NAME (whats_returned)
6425 && DECL_FUNCTION_SCOPE_P (whats_returned)
6426 && !(TREE_STATIC (whats_returned)
6427 || TREE_PUBLIC (whats_returned)))
6429 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6430 warning (0, "reference to local variable %q+D returned",
6433 warning (0, "address of local variable %q+D returned",
6439 /* Check that returning RETVAL from the current function is valid.
6440 Return an expression explicitly showing all conversions required to
6441 change RETVAL into the function return type, and to assign it to
6442 the DECL_RESULT for the function. Set *NO_WARNING to true if
6443 code reaches end of non-void function warning shouldn't be issued
6444 on this RETURN_EXPR. */
6447 check_return_expr (tree retval, bool *no_warning)
6450 /* The type actually returned by the function, after any
6453 int fn_returns_value_p;
6455 *no_warning = false;
6457 /* A `volatile' function is one that isn't supposed to return, ever.
6458 (This is a G++ extension, used to get better code for functions
6459 that call the `volatile' function.) */
6460 if (TREE_THIS_VOLATILE (current_function_decl))
6461 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6463 /* Check for various simple errors. */
6464 if (DECL_DESTRUCTOR_P (current_function_decl))
6467 error ("returning a value from a destructor");
6470 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6472 if (in_function_try_handler)
6473 /* If a return statement appears in a handler of the
6474 function-try-block of a constructor, the program is ill-formed. */
6475 error ("cannot return from a handler of a function-try-block of a constructor");
6477 /* You can't return a value from a constructor. */
6478 error ("returning a value from a constructor");
6482 if (processing_template_decl)
6484 current_function_returns_value = 1;
6488 /* When no explicit return-value is given in a function with a named
6489 return value, the named return value is used. */
6490 result = DECL_RESULT (current_function_decl);
6491 valtype = TREE_TYPE (result);
6492 gcc_assert (valtype != NULL_TREE);
6493 fn_returns_value_p = !VOID_TYPE_P (valtype);
6494 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6497 /* Check for a return statement with no return value in a function
6498 that's supposed to return a value. */
6499 if (!retval && fn_returns_value_p)
6501 pedwarn ("return-statement with no value, in function returning %qT",
6503 /* Clear this, so finish_function won't say that we reach the
6504 end of a non-void function (which we don't, we gave a
6506 current_function_returns_null = 0;
6507 /* And signal caller that TREE_NO_WARNING should be set on the
6508 RETURN_EXPR to avoid control reaches end of non-void function
6509 warnings in tree-cfg.c. */
6512 /* Check for a return statement with a value in a function that
6513 isn't supposed to return a value. */
6514 else if (retval && !fn_returns_value_p)
6516 if (VOID_TYPE_P (TREE_TYPE (retval)))
6517 /* You can return a `void' value from a function of `void'
6518 type. In that case, we have to evaluate the expression for
6519 its side-effects. */
6520 finish_expr_stmt (retval);
6522 pedwarn ("return-statement with a value, in function "
6523 "returning 'void'");
6525 current_function_returns_null = 1;
6527 /* There's really no value to return, after all. */
6531 /* Remember that this function can sometimes return without a
6533 current_function_returns_null = 1;
6535 /* Remember that this function did return a value. */
6536 current_function_returns_value = 1;
6538 /* Check for erroneous operands -- but after giving ourselves a
6539 chance to provide an error about returning a value from a void
6541 if (error_operand_p (retval))
6543 current_function_return_value = error_mark_node;
6544 return error_mark_node;
6547 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6548 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6549 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6550 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6552 && null_ptr_cst_p (retval))
6553 warning (0, "%<operator new%> must not return NULL unless it is "
6554 "declared %<throw()%> (or -fcheck-new is in effect)");
6556 /* Effective C++ rule 15. See also start_function. */
6558 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6562 /* The function return type must be a reference to the current
6564 if (TREE_CODE (valtype) == REFERENCE_TYPE
6565 && same_type_ignoring_top_level_qualifiers_p
6566 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6568 /* Returning '*this' is obviously OK. */
6569 if (retval == current_class_ref)
6571 /* If we are calling a function whose return type is the same of
6572 the current class reference, it is ok. */
6573 else if (TREE_CODE (retval) == INDIRECT_REF
6574 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6579 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6582 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6584 [...] For a function with a class return type, if the expression
6585 in the return statement is the name of a local object, and the cv-
6586 unqualified type of the local object is the same as the function
6587 return type, an implementation is permitted to omit creating the tem-
6588 porary object to hold the function return value [...]
6590 So, if this is a value-returning function that always returns the same
6591 local variable, remember it.
6593 It might be nice to be more flexible, and choose the first suitable
6594 variable even if the function sometimes returns something else, but
6595 then we run the risk of clobbering the variable we chose if the other
6596 returned expression uses the chosen variable somehow. And people expect
6597 this restriction, anyway. (jason 2000-11-19)
6599 See finish_function and finalize_nrv for the rest of this optimization. */
6601 if (fn_returns_value_p && flag_elide_constructors)
6603 if (retval != NULL_TREE
6604 && (current_function_return_value == NULL_TREE
6605 || current_function_return_value == retval)
6606 && TREE_CODE (retval) == VAR_DECL
6607 && DECL_CONTEXT (retval) == current_function_decl
6608 && ! TREE_STATIC (retval)
6609 && (DECL_ALIGN (retval)
6610 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6611 && same_type_p ((TYPE_MAIN_VARIANT
6612 (TREE_TYPE (retval))),
6614 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6615 current_function_return_value = retval;
6617 current_function_return_value = error_mark_node;
6620 /* We don't need to do any conversions when there's nothing being
6625 /* Do any required conversions. */
6626 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6627 /* No conversions are required. */
6631 /* The type the function is declared to return. */
6632 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6634 /* The functype's return type will have been set to void, if it
6635 was an incomplete type. Just treat this as 'return;' */
6636 if (VOID_TYPE_P (functype))
6637 return error_mark_node;
6639 /* First convert the value to the function's return type, then
6640 to the type of return value's location to handle the
6641 case that functype is smaller than the valtype. */
6642 retval = convert_for_initialization
6643 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6644 "return", NULL_TREE, 0);
6645 retval = convert (valtype, retval);
6647 /* If the conversion failed, treat this just like `return;'. */
6648 if (retval == error_mark_node)
6650 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6651 else if (! current_function_returns_struct
6652 && TREE_CODE (retval) == TARGET_EXPR
6653 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6654 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6655 TREE_OPERAND (retval, 0));
6657 maybe_warn_about_returning_address_of_local (retval);
6660 /* Actually copy the value returned into the appropriate location. */
6661 if (retval && retval != result)
6662 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6668 /* Returns nonzero if the pointer-type FROM can be converted to the
6669 pointer-type TO via a qualification conversion. If CONSTP is -1,
6670 then we return nonzero if the pointers are similar, and the
6671 cv-qualification signature of FROM is a proper subset of that of TO.
6673 If CONSTP is positive, then all outer pointers have been
6677 comp_ptr_ttypes_real (tree to, tree from, int constp)
6679 bool to_more_cv_qualified = false;
6681 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6683 if (TREE_CODE (to) != TREE_CODE (from))
6686 if (TREE_CODE (from) == OFFSET_TYPE
6687 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6688 TYPE_OFFSET_BASETYPE (to)))
6691 /* Const and volatile mean something different for function types,
6692 so the usual checks are not appropriate. */
6693 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6695 /* In Objective-C++, some types may have been 'volatilized' by
6696 the compiler for EH; when comparing them here, the volatile
6697 qualification must be ignored. */
6698 bool objc_quals_match = objc_type_quals_match (to, from);
6700 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6703 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6707 to_more_cv_qualified = true;
6711 constp &= TYPE_READONLY (to);
6714 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6715 return ((constp >= 0 || to_more_cv_qualified)
6716 && same_type_ignoring_top_level_qualifiers_p (to, from));
6720 /* When comparing, say, char ** to char const **, this function takes
6721 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6722 types to this function. */
6725 comp_ptr_ttypes (tree to, tree from)
6727 return comp_ptr_ttypes_real (to, from, 1);
6730 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6731 type or inheritance-related types, regardless of cv-quals. */
6734 ptr_reasonably_similar (tree to, tree from)
6736 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6738 /* Any target type is similar enough to void. */
6739 if (TREE_CODE (to) == VOID_TYPE
6740 || TREE_CODE (from) == VOID_TYPE)
6743 if (TREE_CODE (to) != TREE_CODE (from))
6746 if (TREE_CODE (from) == OFFSET_TYPE
6747 && comptypes (TYPE_OFFSET_BASETYPE (to),
6748 TYPE_OFFSET_BASETYPE (from),
6749 COMPARE_BASE | COMPARE_DERIVED))
6752 if (TREE_CODE (to) == VECTOR_TYPE
6753 && vector_types_convertible_p (to, from))
6756 if (TREE_CODE (to) == INTEGER_TYPE
6757 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6760 if (TREE_CODE (to) == FUNCTION_TYPE)
6763 if (TREE_CODE (to) != POINTER_TYPE)
6765 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6766 COMPARE_BASE | COMPARE_DERIVED);
6770 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6771 pointer-to-member types) are the same, ignoring cv-qualification at
6775 comp_ptr_ttypes_const (tree to, tree from)
6777 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6779 if (TREE_CODE (to) != TREE_CODE (from))
6782 if (TREE_CODE (from) == OFFSET_TYPE
6783 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6784 TYPE_OFFSET_BASETYPE (to)))
6787 if (TREE_CODE (to) != POINTER_TYPE)
6788 return same_type_ignoring_top_level_qualifiers_p (to, from);
6792 /* Returns the type qualifiers for this type, including the qualifiers on the
6793 elements for an array type. */
6796 cp_type_quals (tree type)
6798 type = strip_array_types (type);
6799 if (type == error_mark_node)
6800 return TYPE_UNQUALIFIED;
6801 return TYPE_QUALS (type);
6804 /* Returns nonzero if the TYPE contains a mutable member. */
6807 cp_has_mutable_p (tree type)
6809 type = strip_array_types (type);
6811 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6814 /* Apply the TYPE_QUALS to the new DECL. */
6816 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6818 tree type = TREE_TYPE (decl);
6820 if (type == error_mark_node)
6823 if (TREE_CODE (type) == FUNCTION_TYPE
6824 && type_quals != TYPE_UNQUALIFIED)
6826 /* This was an error in C++98 (cv-qualifiers cannot be added to
6827 a function type), but DR 295 makes the code well-formed by
6828 dropping the extra qualifiers. */
6831 tree bad_type = build_qualified_type (type, type_quals);
6832 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6836 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6840 /* Avoid setting TREE_READONLY incorrectly. */
6841 if (/* If the object has a constructor, the constructor may modify
6843 TYPE_NEEDS_CONSTRUCTING (type)
6844 /* If the type isn't complete, we don't know yet if it will need
6846 || !COMPLETE_TYPE_P (type)
6847 /* If the type has a mutable component, that component might be
6849 || TYPE_HAS_MUTABLE_P (type))
6850 type_quals &= ~TYPE_QUAL_CONST;
6852 c_apply_type_quals_to_decl (type_quals, decl);
6855 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6856 exemplar types such that casting T1 to T2 is casting away constness
6857 if and only if there is no implicit conversion from T1 to T2. */
6860 casts_away_constness_r (tree *t1, tree *t2)
6865 /* [expr.const.cast]
6867 For multi-level pointer to members and multi-level mixed pointers
6868 and pointers to members (conv.qual), the "member" aspect of a
6869 pointer to member level is ignored when determining if a const
6870 cv-qualifier has been cast away. */
6871 /* [expr.const.cast]
6873 For two pointer types:
6875 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6876 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6879 casting from X1 to X2 casts away constness if, for a non-pointer
6880 type T there does not exist an implicit conversion (clause
6883 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6887 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6888 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6889 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6891 *t1 = cp_build_qualified_type (void_type_node,
6892 cp_type_quals (*t1));
6893 *t2 = cp_build_qualified_type (void_type_node,
6894 cp_type_quals (*t2));
6898 quals1 = cp_type_quals (*t1);
6899 quals2 = cp_type_quals (*t2);
6901 if (TYPE_PTRMEM_P (*t1))
6902 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6904 *t1 = TREE_TYPE (*t1);
6905 if (TYPE_PTRMEM_P (*t2))
6906 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6908 *t2 = TREE_TYPE (*t2);
6910 casts_away_constness_r (t1, t2);
6911 *t1 = build_pointer_type (*t1);
6912 *t2 = build_pointer_type (*t2);
6913 *t1 = cp_build_qualified_type (*t1, quals1);
6914 *t2 = cp_build_qualified_type (*t2, quals2);
6917 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6921 casts_away_constness (tree t1, tree t2)
6923 if (TREE_CODE (t2) == REFERENCE_TYPE)
6925 /* [expr.const.cast]
6927 Casting from an lvalue of type T1 to an lvalue of type T2
6928 using a reference cast casts away constness if a cast from an
6929 rvalue of type "pointer to T1" to the type "pointer to T2"
6930 casts away constness. */
6931 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6932 return casts_away_constness (build_pointer_type (t1),
6933 build_pointer_type (TREE_TYPE (t2)));
6936 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6937 /* [expr.const.cast]
6939 Casting from an rvalue of type "pointer to data member of X
6940 of type T1" to the type "pointer to data member of Y of type
6941 T2" casts away constness if a cast from an rvalue of type
6942 "pointer to T1" to the type "pointer to T2" casts away
6944 return casts_away_constness
6945 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6946 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6948 /* Casting away constness is only something that makes sense for
6949 pointer or reference types. */
6950 if (TREE_CODE (t1) != POINTER_TYPE
6951 || TREE_CODE (t2) != POINTER_TYPE)
6954 /* Top-level qualifiers don't matter. */
6955 t1 = TYPE_MAIN_VARIANT (t1);
6956 t2 = TYPE_MAIN_VARIANT (t2);
6957 casts_away_constness_r (&t1, &t2);
6958 if (!can_convert (t2, t1))
6964 /* If T is a REFERENCE_TYPE return the type to which T refers.
6965 Otherwise, return T itself. */
6968 non_reference (tree t)
6970 if (TREE_CODE (t) == REFERENCE_TYPE)
6976 /* Return nonzero if REF is an lvalue valid for this language;
6977 otherwise, print an error message and return zero. USE says
6978 how the lvalue is being used and so selects the error message. */
6981 lvalue_or_else (tree ref, enum lvalue_use use)
6983 int win = lvalue_p (ref);