1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
47 static tree pfn_from_ptrmemfunc (tree);
48 static tree convert_for_assignment (tree, tree, const char *, tree, int);
49 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
50 static tree rationalize_conditional_expr (enum tree_code, tree);
51 static int comp_ptr_ttypes_real (tree, tree, int);
52 static bool comp_except_types (tree, tree, bool);
53 static bool comp_array_types (tree, tree, bool);
54 static tree common_base_type (tree, tree);
55 static tree pointer_diff (tree, tree, tree);
56 static tree get_delta_difference (tree, tree, bool, bool);
57 static void casts_away_constness_r (tree *, tree *);
58 static bool casts_away_constness (tree, tree);
59 static void maybe_warn_about_returning_address_of_local (tree);
60 static tree lookup_destructor (tree, tree, tree);
61 static tree convert_arguments (tree, tree, tree, int);
63 /* Do `exp = require_complete_type (exp);' to make sure exp
64 does not have an incomplete type. (That includes void types.)
65 Returns the error_mark_node if the VALUE does not have
66 complete type when this function returns. */
69 require_complete_type (tree value)
73 if (processing_template_decl || value == error_mark_node)
76 if (TREE_CODE (value) == OVERLOAD)
77 type = unknown_type_node;
79 type = TREE_TYPE (value);
81 if (type == error_mark_node)
82 return error_mark_node;
84 /* First, detect a valid value with a complete type. */
85 if (COMPLETE_TYPE_P (type))
88 if (complete_type_or_else (type, value))
91 return error_mark_node;
94 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
95 a template instantiation, do the instantiation. Returns TYPE,
96 whether or not it could be completed, unless something goes
97 horribly wrong, in which case the error_mark_node is returned. */
100 complete_type (tree type)
102 if (type == NULL_TREE)
103 /* Rather than crash, we return something sure to cause an error
105 return error_mark_node;
107 if (type == error_mark_node || COMPLETE_TYPE_P (type))
109 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
111 tree t = complete_type (TREE_TYPE (type));
112 unsigned int needs_constructing, has_nontrivial_dtor;
113 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
116 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
118 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
119 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
121 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
122 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
125 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
126 instantiate_class_template (TYPE_MAIN_VARIANT (type));
131 /* Like complete_type, but issue an error if the TYPE cannot be completed.
132 VALUE is used for informative diagnostics.
133 Returns NULL_TREE if the type cannot be made complete. */
136 complete_type_or_else (tree type, tree value)
138 type = complete_type (type);
139 if (type == error_mark_node)
140 /* We already issued an error. */
142 else if (!COMPLETE_TYPE_P (type))
144 cxx_incomplete_type_diagnostic (value, type, 0);
151 /* Return truthvalue of whether type of EXP is instantiated. */
154 type_unknown_p (tree exp)
156 return (TREE_CODE (exp) == TREE_LIST
157 || TREE_TYPE (exp) == unknown_type_node);
161 /* Return the common type of two parameter lists.
162 We assume that comptypes has already been done and returned 1;
163 if that isn't so, this may crash.
165 As an optimization, free the space we allocate if the parameter
166 lists are already common. */
169 commonparms (tree p1, tree p2)
171 tree oldargs = p1, newargs, n;
175 len = list_length (p1);
176 newargs = tree_last (p1);
178 if (newargs == void_list_node)
187 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
192 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
194 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
196 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
199 else if (! TREE_PURPOSE (p1))
201 if (TREE_PURPOSE (p2))
203 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
209 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
211 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
213 if (TREE_VALUE (p1) != TREE_VALUE (p2))
216 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
219 TREE_VALUE (n) = TREE_VALUE (p1);
227 /* Given a type, perhaps copied for a typedef,
228 find the "original" version of it. */
230 original_type (tree t)
232 int quals = cp_type_quals (t);
233 while (t != error_mark_node
234 && TYPE_NAME (t) != NULL_TREE)
236 tree x = TYPE_NAME (t);
237 if (TREE_CODE (x) != TYPE_DECL)
239 x = DECL_ORIGINAL_TYPE (x);
244 return cp_build_qualified_type (t, quals);
247 /* T1 and T2 are arithmetic or enumeration types. Return the type
248 that will result from the "usual arithmetic conversions" on T1 and
249 T2 as described in [expr]. */
252 type_after_usual_arithmetic_conversions (tree t1, tree t2)
254 enum tree_code code1 = TREE_CODE (t1);
255 enum tree_code code2 = TREE_CODE (t2);
258 /* FIXME: Attributes. */
259 gcc_assert (ARITHMETIC_TYPE_P (t1)
260 || TREE_CODE (t1) == COMPLEX_TYPE
261 || TREE_CODE (t1) == VECTOR_TYPE
262 || TREE_CODE (t1) == ENUMERAL_TYPE);
263 gcc_assert (ARITHMETIC_TYPE_P (t2)
264 || TREE_CODE (t2) == COMPLEX_TYPE
265 || TREE_CODE (t2) == VECTOR_TYPE
266 || TREE_CODE (t2) == ENUMERAL_TYPE);
268 /* In what follows, we slightly generalize the rules given in [expr] so
269 as to deal with `long long' and `complex'. First, merge the
271 attributes = (*targetm.merge_type_attributes) (t1, t2);
273 /* If one type is complex, form the common type of the non-complex
274 components, then make that complex. Use T1 or T2 if it is the
276 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
278 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
279 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
281 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
283 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
284 return build_type_attribute_variant (t1, attributes);
285 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
286 return build_type_attribute_variant (t2, attributes);
288 return build_type_attribute_variant (build_complex_type (subtype),
292 if (code1 == VECTOR_TYPE)
294 /* When we get here we should have two vectors of the same size.
295 Just prefer the unsigned one if present. */
296 if (TYPE_UNSIGNED (t1))
297 return build_type_attribute_variant (t1, attributes);
299 return build_type_attribute_variant (t2, attributes);
302 /* If only one is real, use it as the result. */
303 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
304 return build_type_attribute_variant (t1, attributes);
305 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
306 return build_type_attribute_variant (t2, attributes);
308 /* Perform the integral promotions. */
309 if (code1 != REAL_TYPE)
311 t1 = type_promotes_to (t1);
312 t2 = type_promotes_to (t2);
315 /* Both real or both integers; use the one with greater precision. */
316 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
317 return build_type_attribute_variant (t1, attributes);
318 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
319 return build_type_attribute_variant (t2, attributes);
321 /* The types are the same; no need to do anything fancy. */
322 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
323 return build_type_attribute_variant (t1, attributes);
325 if (code1 != REAL_TYPE)
327 /* If one is unsigned long long, then convert the other to unsigned
329 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
330 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
331 return build_type_attribute_variant (long_long_unsigned_type_node,
333 /* If one is a long long, and the other is an unsigned long, and
334 long long can represent all the values of an unsigned long, then
335 convert to a long long. Otherwise, convert to an unsigned long
336 long. Otherwise, if either operand is long long, convert the
339 Since we're here, we know the TYPE_PRECISION is the same;
340 therefore converting to long long cannot represent all the values
341 of an unsigned long, so we choose unsigned long long in that
343 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
344 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
346 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
347 ? long_long_unsigned_type_node
348 : long_long_integer_type_node);
349 return build_type_attribute_variant (t, attributes);
352 /* Go through the same procedure, but for longs. */
353 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
354 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
355 return build_type_attribute_variant (long_unsigned_type_node,
357 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
358 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
360 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
361 ? long_unsigned_type_node : long_integer_type_node);
362 return build_type_attribute_variant (t, attributes);
364 /* Otherwise prefer the unsigned one. */
365 if (TYPE_UNSIGNED (t1))
366 return build_type_attribute_variant (t1, attributes);
368 return build_type_attribute_variant (t2, attributes);
372 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
373 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
374 return build_type_attribute_variant (long_double_type_node,
376 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
377 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
378 return build_type_attribute_variant (double_type_node,
380 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
381 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
382 return build_type_attribute_variant (float_type_node,
385 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
386 the standard C++ floating-point types. Logic earlier in this
387 function has already eliminated the possibility that
388 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
389 compelling reason to choose one or the other. */
390 return build_type_attribute_variant (t1, attributes);
394 /* Subroutine of composite_pointer_type to implement the recursive
395 case. See that function for documentation fo the parameters. */
398 composite_pointer_type_r (tree t1, tree t2, const char* location)
405 /* Determine the types pointed to by T1 and T2. */
406 if (TREE_CODE (t1) == POINTER_TYPE)
408 pointee1 = TREE_TYPE (t1);
409 pointee2 = TREE_TYPE (t2);
413 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
414 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
419 Otherwise, the composite pointer type is a pointer type
420 similar (_conv.qual_) to the type of one of the operands,
421 with a cv-qualification signature (_conv.qual_) that is the
422 union of the cv-qualification signatures of the operand
424 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
425 result_type = pointee1;
426 else if ((TREE_CODE (pointee1) == POINTER_TYPE
427 && TREE_CODE (pointee2) == POINTER_TYPE)
428 || (TYPE_PTR_TO_MEMBER_P (pointee1)
429 && TYPE_PTR_TO_MEMBER_P (pointee2)))
430 result_type = composite_pointer_type_r (pointee1, pointee2, location);
433 pedwarn ("%s between distinct pointer types %qT and %qT "
436 result_type = void_type_node;
438 result_type = cp_build_qualified_type (result_type,
439 (cp_type_quals (pointee1)
440 | cp_type_quals (pointee2)));
441 /* If the original types were pointers to members, so is the
443 if (TYPE_PTR_TO_MEMBER_P (t1))
445 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
446 TYPE_PTRMEM_CLASS_TYPE (t2)))
447 pedwarn ("%s between distinct pointer types %qT and %qT "
450 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
454 result_type = build_pointer_type (result_type);
456 /* Merge the attributes. */
457 attributes = (*targetm.merge_type_attributes) (t1, t2);
458 return build_type_attribute_variant (result_type, attributes);
461 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
462 ARG1 and ARG2 are the values with those types. The LOCATION is a
463 string describing the current location, in case an error occurs.
465 This routine also implements the computation of a common type for
466 pointers-to-members as per [expr.eq]. */
469 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
470 const char* location)
477 If one operand is a null pointer constant, the composite pointer
478 type is the type of the other operand. */
479 if (null_ptr_cst_p (arg1))
481 if (null_ptr_cst_p (arg2))
488 If one of the operands has type "pointer to cv1 void*", then
489 the other has type "pointer to cv2T", and the composite pointer
490 type is "pointer to cv12 void", where cv12 is the union of cv1
493 If either type is a pointer to void, make sure it is T1. */
494 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
502 /* Now, if T1 is a pointer to void, merge the qualifiers. */
503 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
508 if (pedantic && TYPE_PTRFN_P (t2))
509 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
510 "and pointer-to-function", location);
512 = cp_build_qualified_type (void_type_node,
513 (cp_type_quals (TREE_TYPE (t1))
514 | cp_type_quals (TREE_TYPE (t2))));
515 result_type = build_pointer_type (result_type);
516 /* Merge the attributes. */
517 attributes = (*targetm.merge_type_attributes) (t1, t2);
518 return build_type_attribute_variant (result_type, attributes);
521 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
522 && TREE_CODE (t2) == POINTER_TYPE)
524 if (objc_compare_types (t1, t2, -3, NULL_TREE))
528 /* [expr.eq] permits the application of a pointer conversion to
529 bring the pointers to a common type. */
530 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
531 && CLASS_TYPE_P (TREE_TYPE (t1))
532 && CLASS_TYPE_P (TREE_TYPE (t2))
533 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
536 class1 = TREE_TYPE (t1);
537 class2 = TREE_TYPE (t2);
539 if (DERIVED_FROM_P (class1, class2))
540 t2 = (build_pointer_type
541 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
542 else if (DERIVED_FROM_P (class2, class1))
543 t1 = (build_pointer_type
544 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
547 error ("%s between distinct pointer types %qT and %qT "
548 "lacks a cast", location, t1, t2);
549 return error_mark_node;
552 /* [expr.eq] permits the application of a pointer-to-member
553 conversion to change the class type of one of the types. */
554 else if (TYPE_PTR_TO_MEMBER_P (t1)
555 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
556 TYPE_PTRMEM_CLASS_TYPE (t2)))
558 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
559 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
561 if (DERIVED_FROM_P (class1, class2))
562 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
563 else if (DERIVED_FROM_P (class2, class1))
564 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
567 error ("%s between distinct pointer-to-member types %qT and %qT "
568 "lacks a cast", location, t1, t2);
569 return error_mark_node;
573 return composite_pointer_type_r (t1, t2, location);
576 /* Return the merged type of two types.
577 We assume that comptypes has already been done and returned 1;
578 if that isn't so, this may crash.
580 This just combines attributes and default arguments; any other
581 differences would cause the two types to compare unalike. */
584 merge_types (tree t1, tree t2)
586 enum tree_code code1;
587 enum tree_code code2;
590 /* Save time if the two types are the same. */
593 if (original_type (t1) == original_type (t2))
596 /* If one type is nonsense, use the other. */
597 if (t1 == error_mark_node)
599 if (t2 == error_mark_node)
602 /* Merge the attributes. */
603 attributes = (*targetm.merge_type_attributes) (t1, t2);
605 if (TYPE_PTRMEMFUNC_P (t1))
606 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
607 if (TYPE_PTRMEMFUNC_P (t2))
608 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
610 code1 = TREE_CODE (t1);
611 code2 = TREE_CODE (t2);
617 /* For two pointers, do this recursively on the target type. */
619 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
620 int quals = cp_type_quals (t1);
622 if (code1 == POINTER_TYPE)
623 t1 = build_pointer_type (target);
625 t1 = build_reference_type (target);
626 t1 = build_type_attribute_variant (t1, attributes);
627 t1 = cp_build_qualified_type (t1, quals);
629 if (TREE_CODE (target) == METHOD_TYPE)
630 t1 = build_ptrmemfunc_type (t1);
639 quals = cp_type_quals (t1);
640 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
641 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
642 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
644 t1 = cp_build_qualified_type (t1, quals);
650 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
651 /* Save space: see if the result is identical to one of the args. */
652 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
653 return build_type_attribute_variant (t1, attributes);
654 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
655 return build_type_attribute_variant (t2, attributes);
656 /* Merge the element types, and have a size if either arg has one. */
657 t1 = build_cplus_array_type
658 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
663 /* Function types: prefer the one that specified arg types.
664 If both do, merge the arg types. Also merge the return types. */
666 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
667 tree p1 = TYPE_ARG_TYPES (t1);
668 tree p2 = TYPE_ARG_TYPES (t2);
671 /* Save space: see if the result is identical to one of the args. */
672 if (valtype == TREE_TYPE (t1) && ! p2)
673 return cp_build_type_attribute_variant (t1, attributes);
674 if (valtype == TREE_TYPE (t2) && ! p1)
675 return cp_build_type_attribute_variant (t2, attributes);
677 /* Simple way if one arg fails to specify argument types. */
678 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
680 rval = build_function_type (valtype, p2);
681 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
682 rval = build_exception_variant (rval, raises);
683 return cp_build_type_attribute_variant (rval, attributes);
685 raises = TYPE_RAISES_EXCEPTIONS (t1);
686 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
688 rval = build_function_type (valtype, p1);
690 rval = build_exception_variant (rval, raises);
691 return cp_build_type_attribute_variant (rval, attributes);
694 rval = build_function_type (valtype, commonparms (p1, p2));
695 t1 = build_exception_variant (rval, raises);
701 /* Get this value the long way, since TYPE_METHOD_BASETYPE
702 is just the main variant of this. */
703 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
704 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
707 /* If this was a member function type, get back to the
708 original type of type member function (i.e., without
709 the class instance variable up front. */
710 t1 = build_function_type (TREE_TYPE (t1),
711 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
712 t2 = build_function_type (TREE_TYPE (t2),
713 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
714 t3 = merge_types (t1, t2);
715 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
716 TYPE_ARG_TYPES (t3));
717 t1 = build_exception_variant (t3, raises);
722 /* There is no need to merge attributes into a TYPENAME_TYPE.
723 When the type is instantiated it will have whatever
724 attributes result from the instantiation. */
730 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
732 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
735 return cp_build_type_attribute_variant (t1, attributes);
738 /* Return the common type of two types.
739 We assume that comptypes has already been done and returned 1;
740 if that isn't so, this may crash.
742 This is the type for the result of most arithmetic operations
743 if the operands have the given two types. */
746 common_type (tree t1, tree t2)
748 enum tree_code code1;
749 enum tree_code code2;
751 /* If one type is nonsense, bail. */
752 if (t1 == error_mark_node || t2 == error_mark_node)
753 return error_mark_node;
755 code1 = TREE_CODE (t1);
756 code2 = TREE_CODE (t2);
758 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
759 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
760 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
761 || code2 == COMPLEX_TYPE || code2 == VECTOR_TYPE))
762 return type_after_usual_arithmetic_conversions (t1, t2);
764 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
765 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
766 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
767 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
773 /* Compare two exception specifier types for exactness or subsetness, if
774 allowed. Returns false for mismatch, true for match (same, or
777 [except.spec] "If a class X ... objects of class X or any class publicly
778 and unambiguously derived from X. Similarly, if a pointer type Y * ...
779 exceptions of type Y * or that are pointers to any type publicly and
780 unambiguously derived from Y. Otherwise a function only allows exceptions
781 that have the same type ..."
782 This does not mention cv qualifiers and is different to what throw
783 [except.throw] and catch [except.catch] will do. They will ignore the
784 top level cv qualifiers, and allow qualifiers in the pointer to class
787 We implement the letter of the standard. */
790 comp_except_types (tree a, tree b, bool exact)
792 if (same_type_p (a, b))
796 if (cp_type_quals (a) || cp_type_quals (b))
799 if (TREE_CODE (a) == POINTER_TYPE
800 && TREE_CODE (b) == POINTER_TYPE)
804 if (cp_type_quals (a) || cp_type_quals (b))
808 if (TREE_CODE (a) != RECORD_TYPE
809 || TREE_CODE (b) != RECORD_TYPE)
812 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
818 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
819 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
820 otherwise it must be exact. Exception lists are unordered, but
821 we've already filtered out duplicates. Most lists will be in order,
822 we should try to make use of that. */
825 comp_except_specs (tree t1, tree t2, bool exact)
834 if (t1 == NULL_TREE) /* T1 is ... */
835 return t2 == NULL_TREE || !exact;
836 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
837 return t2 != NULL_TREE && !TREE_VALUE (t2);
838 if (t2 == NULL_TREE) /* T2 is ... */
840 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
843 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
844 Count how many we find, to determine exactness. For exact matching and
845 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
847 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
849 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
851 tree a = TREE_VALUE (probe);
852 tree b = TREE_VALUE (t2);
854 if (comp_except_types (a, b, exact))
856 if (probe == base && exact)
857 base = TREE_CHAIN (probe);
862 if (probe == NULL_TREE)
865 return !exact || base == NULL_TREE || length == list_length (t1);
868 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
869 [] can match [size]. */
872 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
881 /* The type of the array elements must be the same. */
882 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
885 d1 = TYPE_DOMAIN (t1);
886 d2 = TYPE_DOMAIN (t2);
891 /* If one of the arrays is dimensionless, and the other has a
892 dimension, they are of different types. However, it is valid to
900 declarations for an array object can specify
901 array types that differ by the presence or absence of a major
902 array bound (_dcl.array_). */
904 return allow_redeclaration;
906 /* Check that the dimensions are the same. */
908 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
910 max1 = TYPE_MAX_VALUE (d1);
911 max2 = TYPE_MAX_VALUE (d2);
912 if (processing_template_decl && !abi_version_at_least (2)
913 && !value_dependent_expression_p (max1)
914 && !value_dependent_expression_p (max2))
916 /* With abi-1 we do not fold non-dependent array bounds, (and
917 consequently mangle them incorrectly). We must therefore
918 fold them here, to verify the domains have the same
924 if (!cp_tree_equal (max1, max2))
930 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
931 is a bitwise-or of the COMPARE_* flags. */
934 comptypes (tree t1, tree t2, int strict)
939 /* Suppress errors caused by previously reported errors. */
940 if (t1 == error_mark_node || t2 == error_mark_node)
943 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
945 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
946 current instantiation. */
947 if (TREE_CODE (t1) == TYPENAME_TYPE)
949 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
951 if (resolved != error_mark_node)
955 if (TREE_CODE (t2) == TYPENAME_TYPE)
957 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
959 if (resolved != error_mark_node)
963 if (TYPE_PTRMEMFUNC_P (t1))
964 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
965 if (TYPE_PTRMEMFUNC_P (t2))
966 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
968 /* Different classes of types can't be compatible. */
969 if (TREE_CODE (t1) != TREE_CODE (t2))
972 /* Qualifiers must match. For array types, we will check when we
973 recur on the array element types. */
974 if (TREE_CODE (t1) != ARRAY_TYPE
975 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
977 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
980 /* Allow for two different type nodes which have essentially the same
981 definition. Note that we already checked for equality of the type
982 qualifiers (just above). */
984 if (TREE_CODE (t1) != ARRAY_TYPE
985 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
988 /* Compare the types. Break out if they could be the same. */
989 switch (TREE_CODE (t1))
991 case TEMPLATE_TEMPLATE_PARM:
992 case BOUND_TEMPLATE_TEMPLATE_PARM:
993 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
994 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
996 if (!comp_template_parms
997 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
998 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1000 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1002 /* Don't check inheritance. */
1003 strict = COMPARE_STRICT;
1008 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1009 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1010 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1011 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1014 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1016 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1022 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1023 strict & ~COMPARE_REDECLARATION))
1025 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1030 case REFERENCE_TYPE:
1031 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1032 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1033 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1039 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1041 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1046 /* Target types must match incl. qualifiers. */
1047 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1051 case TEMPLATE_TYPE_PARM:
1052 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1053 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1058 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1059 TYPENAME_TYPE_FULLNAME (t2)))
1061 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1065 case UNBOUND_CLASS_TEMPLATE:
1066 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1068 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1073 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1078 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1079 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1087 /* If we get here, we know that from a target independent POV the
1088 types are the same. Make sure the target attributes are also
1090 return targetm.comp_type_attributes (t1, t2);
1093 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1096 at_least_as_qualified_p (tree type1, tree type2)
1098 int q1 = cp_type_quals (type1);
1099 int q2 = cp_type_quals (type2);
1101 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1102 return (q1 & q2) == q2;
1105 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1106 more cv-qualified that TYPE1, and 0 otherwise. */
1109 comp_cv_qualification (tree type1, tree type2)
1111 int q1 = cp_type_quals (type1);
1112 int q2 = cp_type_quals (type2);
1117 if ((q1 & q2) == q2)
1119 else if ((q1 & q2) == q1)
1125 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1126 subset of the cv-qualification signature of TYPE2, and the types
1127 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1130 comp_cv_qual_signature (tree type1, tree type2)
1132 if (comp_ptr_ttypes_real (type2, type1, -1))
1134 else if (comp_ptr_ttypes_real (type1, type2, -1))
1140 /* If two types share a common base type, return that basetype.
1141 If there is not a unique most-derived base type, this function
1142 returns ERROR_MARK_NODE. */
1145 common_base_type (tree tt1, tree tt2)
1147 tree best = NULL_TREE;
1150 /* If one is a baseclass of another, that's good enough. */
1151 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1153 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1156 /* Otherwise, try to find a unique baseclass of TT1
1157 that is shared by TT2, and follow that down. */
1158 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1160 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1161 tree trial = common_base_type (basetype, tt2);
1165 if (trial == error_mark_node)
1167 if (best == NULL_TREE)
1169 else if (best != trial)
1170 return error_mark_node;
1175 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1177 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1178 tree trial = common_base_type (tt1, basetype);
1182 if (trial == error_mark_node)
1184 if (best == NULL_TREE)
1186 else if (best != trial)
1187 return error_mark_node;
1193 /* Subroutines of `comptypes'. */
1195 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1196 equivalent in the sense that functions with those parameter types
1197 can have equivalent types. The two lists must be equivalent,
1198 element by element. */
1201 compparms (tree parms1, tree parms2)
1205 /* An unspecified parmlist matches any specified parmlist
1206 whose argument types don't need default promotions. */
1208 for (t1 = parms1, t2 = parms2;
1210 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1212 /* If one parmlist is shorter than the other,
1213 they fail to match. */
1216 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1223 /* Process a sizeof or alignof expression where the operand is a
1227 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1232 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1233 if (type == error_mark_node)
1234 return error_mark_node;
1236 type = non_reference (type);
1237 if (TREE_CODE (type) == METHOD_TYPE)
1239 if (complain && (pedantic || warn_pointer_arith))
1240 pedwarn ("invalid application of %qs to a member function",
1241 operator_name_info[(int) op].name);
1242 value = size_one_node;
1245 dependent_p = dependent_type_p (type);
1247 complete_type (type);
1249 /* VLA types will have a non-constant size. In the body of an
1250 uninstantiated template, we don't need to try to compute the
1251 value, because the sizeof expression is not an integral
1252 constant expression in that case. And, if we do try to
1253 compute the value, we'll likely end up with SAVE_EXPRs, which
1254 the template substitution machinery does not expect to see. */
1255 || (processing_template_decl
1256 && COMPLETE_TYPE_P (type)
1257 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1259 value = build_min (op, size_type_node, type);
1260 TREE_READONLY (value) = 1;
1264 return c_sizeof_or_alignof_type (complete_type (type),
1269 /* Process a sizeof expression where the operand is an expression. */
1272 cxx_sizeof_expr (tree e)
1274 if (e == error_mark_node)
1275 return error_mark_node;
1277 if (processing_template_decl)
1279 e = build_min (SIZEOF_EXPR, size_type_node, e);
1280 TREE_SIDE_EFFECTS (e) = 0;
1281 TREE_READONLY (e) = 1;
1286 if (TREE_CODE (e) == COMPONENT_REF
1287 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1288 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1290 error ("invalid application of %<sizeof%> to a bit-field");
1293 else if (is_overloaded_fn (e))
1295 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1299 else if (type_unknown_p (e))
1301 cxx_incomplete_type_error (e, TREE_TYPE (e));
1307 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1310 /* Implement the __alignof keyword: Return the minimum required
1311 alignment of E, measured in bytes. For VAR_DECL's and
1312 FIELD_DECL's return DECL_ALIGN (which can be set from an
1313 "aligned" __attribute__ specification). */
1316 cxx_alignof_expr (tree e)
1320 if (e == error_mark_node)
1321 return error_mark_node;
1323 if (processing_template_decl)
1325 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1326 TREE_SIDE_EFFECTS (e) = 0;
1327 TREE_READONLY (e) = 1;
1332 if (TREE_CODE (e) == VAR_DECL)
1333 t = size_int (DECL_ALIGN_UNIT (e));
1334 else if (TREE_CODE (e) == COMPONENT_REF
1335 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1336 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1338 error ("invalid application of %<__alignof%> to a bit-field");
1341 else if (TREE_CODE (e) == COMPONENT_REF
1342 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1343 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1344 else if (is_overloaded_fn (e))
1346 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1350 else if (type_unknown_p (e))
1352 cxx_incomplete_type_error (e, TREE_TYPE (e));
1356 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1358 return fold_convert (size_type_node, t);
1361 /* Process a sizeof or alignof expression E with code OP where the operand
1362 is an expression. */
1365 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1367 if (op == SIZEOF_EXPR)
1368 return cxx_sizeof_expr (e);
1370 return cxx_alignof_expr (e);
1373 /* EXPR is being used in a context that is not a function call.
1378 The expression can be used only as the left-hand operand of a
1379 member function call.
1381 [expr.mptr.operator]
1383 If the result of .* or ->* is a function, then that result can be
1384 used only as the operand for the function call operator ().
1386 by issuing an error message if appropriate. Returns true iff EXPR
1387 violates these rules. */
1390 invalid_nonstatic_memfn_p (tree expr)
1392 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1394 error ("invalid use of non-static member function");
1400 /* If EXP is a reference to a bitfield, and the type of EXP does not
1401 match the declared type of the bitfield, return the declared type
1402 of the bitfield. Otherwise, return NULL_TREE. */
1405 is_bitfield_expr_with_lowered_type (tree exp)
1409 if (TREE_CODE (exp) == COND_EXPR)
1411 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1413 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1415 if (TREE_CODE (exp) != COMPONENT_REF)
1417 field = TREE_OPERAND (exp, 1);
1418 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1420 if (same_type_ignoring_top_level_qualifiers_p
1421 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1423 return DECL_BIT_FIELD_TYPE (field);
1426 /* Perform the conversions in [expr] that apply when an lvalue appears
1427 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1428 function-to-pointer conversions. In addition, manifest constants
1429 are replaced by their values, and bitfield references are converted
1430 to their declared types.
1432 Although the returned value is being used as an rvalue, this
1433 function does not wrap the returned expression in a
1434 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1435 that the return value is no longer an lvalue. */
1438 decay_conversion (tree exp)
1441 enum tree_code code;
1443 type = TREE_TYPE (exp);
1444 if (type == error_mark_node)
1445 return error_mark_node;
1447 if (type_unknown_p (exp))
1449 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1450 return error_mark_node;
1453 exp = decl_constant_value (exp);
1454 if (error_operand_p (exp))
1455 return error_mark_node;
1457 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1458 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1459 code = TREE_CODE (type);
1460 if (code == VOID_TYPE)
1462 error ("void value not ignored as it ought to be");
1463 return error_mark_node;
1465 if (invalid_nonstatic_memfn_p (exp))
1466 return error_mark_node;
1467 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1468 return build_unary_op (ADDR_EXPR, exp, 0);
1469 if (code == ARRAY_TYPE)
1474 if (TREE_CODE (exp) == INDIRECT_REF)
1475 return build_nop (build_pointer_type (TREE_TYPE (type)),
1476 TREE_OPERAND (exp, 0));
1478 if (TREE_CODE (exp) == COMPOUND_EXPR)
1480 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1481 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1482 TREE_OPERAND (exp, 0), op1);
1486 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1488 error ("invalid use of non-lvalue array");
1489 return error_mark_node;
1492 ptrtype = build_pointer_type (TREE_TYPE (type));
1494 if (TREE_CODE (exp) == VAR_DECL)
1496 if (!cxx_mark_addressable (exp))
1497 return error_mark_node;
1498 adr = build_nop (ptrtype, build_address (exp));
1501 /* This way is better for a COMPONENT_REF since it can
1502 simplify the offset for a component. */
1503 adr = build_unary_op (ADDR_EXPR, exp, 1);
1504 return cp_convert (ptrtype, adr);
1507 /* If a bitfield is used in a context where integral promotion
1508 applies, then the caller is expected to have used
1509 default_conversion. That function promotes bitfields correctly
1510 before calling this function. At this point, if we have a
1511 bitfield referenced, we may assume that is not subject to
1512 promotion, and that, therefore, the type of the resulting rvalue
1513 is the declared type of the bitfield. */
1514 exp = convert_bitfield_to_declared_type (exp);
1516 /* We do not call rvalue() here because we do not want to wrap EXP
1517 in a NON_LVALUE_EXPR. */
1521 Non-class rvalues always have cv-unqualified types. */
1522 type = TREE_TYPE (exp);
1523 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1524 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1529 /* Perform prepatory conversions, as part of the "usual arithmetic
1530 conversions". In particular, as per [expr]:
1532 Whenever an lvalue expression appears as an operand of an
1533 operator that expects the rvalue for that operand, the
1534 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1535 standard conversions are applied to convert the expression to an
1538 In addition, we perform integral promotions here, as those are
1539 applied to both operands to a binary operator before determining
1540 what additional conversions should apply. */
1543 default_conversion (tree exp)
1545 /* Perform the integral promotions first so that bitfield
1546 expressions (which may promote to "int", even if the bitfield is
1547 declared "unsigned") are promoted correctly. */
1548 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1549 exp = perform_integral_promotions (exp);
1550 /* Perform the other conversions. */
1551 exp = decay_conversion (exp);
1556 /* EXPR is an expression with an integral or enumeration type.
1557 Perform the integral promotions in [conv.prom], and return the
1561 perform_integral_promotions (tree expr)
1568 If the bitfield has an enumerated type, it is treated as any
1569 other value of that type for promotion purposes. */
1570 type = is_bitfield_expr_with_lowered_type (expr);
1571 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1572 type = TREE_TYPE (expr);
1573 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1574 promoted_type = type_promotes_to (type);
1575 if (type != promoted_type)
1576 expr = cp_convert (promoted_type, expr);
1580 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1584 inline_conversion (tree exp)
1586 if (TREE_CODE (exp) == FUNCTION_DECL)
1587 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1592 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1593 decay_conversion to one. */
1596 string_conv_p (tree totype, tree exp, int warn)
1600 if (TREE_CODE (totype) != POINTER_TYPE)
1603 t = TREE_TYPE (totype);
1604 if (!same_type_p (t, char_type_node)
1605 && !same_type_p (t, wchar_type_node))
1608 if (TREE_CODE (exp) == STRING_CST)
1610 /* Make sure that we don't try to convert between char and wchar_t. */
1611 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1616 /* Is this a string constant which has decayed to 'const char *'? */
1617 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1618 if (!same_type_p (TREE_TYPE (exp), t))
1621 if (TREE_CODE (exp) != ADDR_EXPR
1622 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1626 /* This warning is not very useful, as it complains about printf. */
1628 warning (OPT_Wwrite_strings,
1629 "deprecated conversion from string constant to %qT",
1635 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1636 can, for example, use as an lvalue. This code used to be in
1637 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1638 expressions, where we're dealing with aggregates. But now it's again only
1639 called from unary_complex_lvalue. The case (in particular) that led to
1640 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1644 rationalize_conditional_expr (enum tree_code code, tree t)
1646 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1647 the first operand is always the one to be used if both operands
1648 are equal, so we know what conditional expression this used to be. */
1649 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1651 /* 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 enum tree_code tcode0 = code0, tcode1 = code1;
3098 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3099 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3100 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3101 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3103 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3104 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3105 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3106 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3108 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3109 resultcode = RDIV_EXPR;
3111 /* When dividing two signed integers, we have to promote to int.
3112 unless we divide by a constant != -1. Note that default
3113 conversion will have been performed on the operands at this
3114 point, so we have to dig out the original type to find out if
3116 shorten = ((TREE_CODE (op0) == NOP_EXPR
3117 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3118 || (TREE_CODE (op1) == INTEGER_CST
3119 && ! integer_all_onesp (op1)));
3128 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3129 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3133 case TRUNC_MOD_EXPR:
3134 case FLOOR_MOD_EXPR:
3135 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3136 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3137 else if (code1 == REAL_TYPE && real_zerop (op1))
3138 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3140 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3142 /* Although it would be tempting to shorten always here, that loses
3143 on some targets, since the modulo instruction is undefined if the
3144 quotient can't be represented in the computation mode. We shorten
3145 only if unsigned or if dividing by something we know != -1. */
3146 shorten = ((TREE_CODE (op0) == NOP_EXPR
3147 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3148 || (TREE_CODE (op1) == INTEGER_CST
3149 && ! integer_all_onesp (op1)));
3154 case TRUTH_ANDIF_EXPR:
3155 case TRUTH_ORIF_EXPR:
3156 case TRUTH_AND_EXPR:
3158 result_type = boolean_type_node;
3161 /* Shift operations: result has same type as first operand;
3162 always convert second operand to int.
3163 Also set SHORT_SHIFT if shifting rightward. */
3166 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3168 result_type = type0;
3169 if (TREE_CODE (op1) == INTEGER_CST)
3171 if (tree_int_cst_lt (op1, integer_zero_node))
3172 warning (0, "right shift count is negative");
3175 if (! integer_zerop (op1))
3177 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3178 warning (0, "right shift count >= width of type");
3181 /* Convert the shift-count to an integer, regardless of
3182 size of value being shifted. */
3183 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3184 op1 = cp_convert (integer_type_node, op1);
3185 /* Avoid converting op1 to result_type later. */
3191 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3193 result_type = type0;
3194 if (TREE_CODE (op1) == INTEGER_CST)
3196 if (tree_int_cst_lt (op1, integer_zero_node))
3197 warning (0, "left shift count is negative");
3198 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3199 warning (0, "left shift count >= width of type");
3201 /* Convert the shift-count to an integer, regardless of
3202 size of value being shifted. */
3203 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3204 op1 = cp_convert (integer_type_node, op1);
3205 /* Avoid converting op1 to result_type later. */
3212 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3214 result_type = type0;
3215 if (TREE_CODE (op1) == INTEGER_CST)
3217 if (tree_int_cst_lt (op1, integer_zero_node))
3218 warning (0, (code == LROTATE_EXPR)
3219 ? G_("left rotate count is negative")
3220 : G_("right rotate count is negative"));
3221 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3222 warning (0, (code == LROTATE_EXPR)
3223 ? G_("left rotate count >= width of type")
3224 : G_("right rotate count >= width of type"));
3226 /* Convert the shift-count to an integer, regardless of
3227 size of value being shifted. */
3228 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3229 op1 = cp_convert (integer_type_node, op1);
3235 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3236 warning (OPT_Wfloat_equal,
3237 "comparing floating point with == or != is unsafe");
3238 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3239 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3240 warning (OPT_Wstring_literal_comparison,
3241 "comparison with string literal");
3243 build_type = boolean_type_node;
3244 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3245 || code0 == COMPLEX_TYPE)
3246 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3247 || code1 == COMPLEX_TYPE))
3249 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3250 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3251 result_type = composite_pointer_type (type0, type1, op0, op1,
3253 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3254 && null_ptr_cst_p (op1))
3255 result_type = type0;
3256 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3257 && null_ptr_cst_p (op0))
3258 result_type = type1;
3259 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3261 result_type = type0;
3262 error ("ISO C++ forbids comparison between pointer and integer");
3264 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3266 result_type = type1;
3267 error ("ISO C++ forbids comparison between pointer and integer");
3269 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3271 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3272 == ptrmemfunc_vbit_in_delta)
3274 tree pfn0 = pfn_from_ptrmemfunc (op0);
3275 tree delta0 = build_ptrmemfunc_access_expr (op0,
3277 tree e1 = cp_build_binary_op (EQ_EXPR,
3279 fold_convert (TREE_TYPE (pfn0),
3280 integer_zero_node));
3281 tree e2 = cp_build_binary_op (BIT_AND_EXPR,
3284 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3285 op0 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e1, e2);
3286 op1 = cp_convert (TREE_TYPE (op0), integer_one_node);
3290 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3291 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3293 result_type = TREE_TYPE (op0);
3295 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3296 return cp_build_binary_op (code, op1, op0);
3297 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3298 && same_type_p (type0, type1))
3300 /* E will be the final comparison. */
3302 /* E1 and E2 are for scratch. */
3310 if (TREE_SIDE_EFFECTS (op0))
3311 op0 = save_expr (op0);
3312 if (TREE_SIDE_EFFECTS (op1))
3313 op1 = save_expr (op1);
3315 pfn0 = pfn_from_ptrmemfunc (op0);
3316 pfn1 = pfn_from_ptrmemfunc (op1);
3317 delta0 = build_ptrmemfunc_access_expr (op0,
3319 delta1 = build_ptrmemfunc_access_expr (op1,
3321 if (TARGET_PTRMEMFUNC_VBIT_LOCATION
3322 == ptrmemfunc_vbit_in_delta)
3327 && ((op0.delta == op1.delta)
3328 || (!op0.pfn && op0.delta & 1 == 0
3329 && op1.delta & 1 == 0))
3331 The reason for the `!op0.pfn' bit is that a NULL
3332 pointer-to-member is any member with a zero PFN and
3333 LSB of the DELTA field is 0. */
3335 e1 = cp_build_binary_op (BIT_AND_EXPR,
3338 e1 = cp_build_binary_op (EQ_EXPR, e1, integer_zero_node);
3339 e2 = cp_build_binary_op (BIT_AND_EXPR,
3342 e2 = cp_build_binary_op (EQ_EXPR, e2, integer_zero_node);
3343 e1 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3344 e2 = cp_build_binary_op (EQ_EXPR,
3346 fold_convert (TREE_TYPE (pfn0),
3347 integer_zero_node));
3348 e2 = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3349 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3350 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3357 && (!op0.pfn || op0.delta == op1.delta))
3359 The reason for the `!op0.pfn' bit is that a NULL
3360 pointer-to-member is any member with a zero PFN; the
3361 DELTA field is unspecified. */
3363 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3364 e2 = cp_build_binary_op (EQ_EXPR,
3366 fold_convert (TREE_TYPE (pfn0),
3367 integer_zero_node));
3368 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3370 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3371 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3372 if (code == EQ_EXPR)
3374 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3378 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3379 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3381 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3382 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3390 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3391 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3393 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3394 result_type = composite_pointer_type (type0, type1, op0, op1,
3402 if (TREE_CODE (orig_op0) == STRING_CST
3403 || TREE_CODE (orig_op1) == STRING_CST)
3404 warning (OPT_Wstring_literal_comparison,
3405 "comparison with string literal");
3407 build_type = boolean_type_node;
3408 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3409 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3411 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3412 result_type = composite_pointer_type (type0, type1, op0, op1,
3414 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3415 && integer_zerop (op1))
3416 result_type = type0;
3417 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3418 && integer_zerop (op0))
3419 result_type = type1;
3420 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3422 result_type = type0;
3423 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3425 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3427 result_type = type1;
3428 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3432 case UNORDERED_EXPR:
3439 build_type = integer_type_node;
3440 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3442 error ("unordered comparison on non-floating point argument");
3443 return error_mark_node;
3452 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3453 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3454 || code1 == COMPLEX_TYPE)))
3455 arithmetic_types_p = 1;
3458 arithmetic_types_p = 0;
3459 /* Vector arithmetic is only allowed when both sides are vectors. */
3460 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3462 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3463 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3466 binary_op_error (code);
3467 return error_mark_node;
3469 arithmetic_types_p = 1;
3472 /* Determine the RESULT_TYPE, if it is not already known. */
3474 && arithmetic_types_p
3475 && (shorten || common || short_compare))
3476 result_type = common_type (type0, type1);
3480 error ("invalid operands of types %qT and %qT to binary %qO",
3481 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3482 return error_mark_node;
3485 /* If we're in a template, the only thing we need to know is the
3487 if (processing_template_decl)
3488 return build2 (resultcode,
3489 build_type ? build_type : result_type,
3492 if (arithmetic_types_p)
3494 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3496 /* For certain operations (which identify themselves by shorten != 0)
3497 if both args were extended from the same smaller type,
3498 do the arithmetic in that type and then extend.
3500 shorten !=0 and !=1 indicates a bitwise operation.
3501 For them, this optimization is safe only if
3502 both args are zero-extended or both are sign-extended.
3503 Otherwise, we might change the result.
3504 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3505 but calculated in (unsigned short) it would be (unsigned short)-1. */
3507 if (shorten && none_complex)
3509 int unsigned0, unsigned1;
3510 tree arg0 = get_narrower (op0, &unsigned0);
3511 tree arg1 = get_narrower (op1, &unsigned1);
3512 /* UNS is 1 if the operation to be done is an unsigned one. */
3513 int uns = TYPE_UNSIGNED (result_type);
3516 final_type = result_type;
3518 /* Handle the case that OP0 does not *contain* a conversion
3519 but it *requires* conversion to FINAL_TYPE. */
3521 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3522 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3523 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3524 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3526 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3528 /* For bitwise operations, signedness of nominal type
3529 does not matter. Consider only how operands were extended. */
3533 /* Note that in all three cases below we refrain from optimizing
3534 an unsigned operation on sign-extended args.
3535 That would not be valid. */
3537 /* Both args variable: if both extended in same way
3538 from same width, do it in that width.
3539 Do it unsigned if args were zero-extended. */
3540 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3541 < TYPE_PRECISION (result_type))
3542 && (TYPE_PRECISION (TREE_TYPE (arg1))
3543 == TYPE_PRECISION (TREE_TYPE (arg0)))
3544 && unsigned0 == unsigned1
3545 && (unsigned0 || !uns))
3546 result_type = c_common_signed_or_unsigned_type
3547 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3548 else if (TREE_CODE (arg0) == INTEGER_CST
3549 && (unsigned1 || !uns)
3550 && (TYPE_PRECISION (TREE_TYPE (arg1))
3551 < TYPE_PRECISION (result_type))
3552 && (type = c_common_signed_or_unsigned_type
3553 (unsigned1, TREE_TYPE (arg1)),
3554 int_fits_type_p (arg0, type)))
3556 else if (TREE_CODE (arg1) == INTEGER_CST
3557 && (unsigned0 || !uns)
3558 && (TYPE_PRECISION (TREE_TYPE (arg0))
3559 < TYPE_PRECISION (result_type))
3560 && (type = c_common_signed_or_unsigned_type
3561 (unsigned0, TREE_TYPE (arg0)),
3562 int_fits_type_p (arg1, type)))
3566 /* Shifts can be shortened if shifting right. */
3571 tree arg0 = get_narrower (op0, &unsigned_arg);
3573 final_type = result_type;
3575 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3576 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3578 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3579 /* We can shorten only if the shift count is less than the
3580 number of bits in the smaller type size. */
3581 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3582 /* If arg is sign-extended and then unsigned-shifted,
3583 we can simulate this with a signed shift in arg's type
3584 only if the extended result is at least twice as wide
3585 as the arg. Otherwise, the shift could use up all the
3586 ones made by sign-extension and bring in zeros.
3587 We can't optimize that case at all, but in most machines
3588 it never happens because available widths are 2**N. */
3589 && (!TYPE_UNSIGNED (final_type)
3591 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3592 <= TYPE_PRECISION (result_type))))
3594 /* Do an unsigned shift if the operand was zero-extended. */
3596 = c_common_signed_or_unsigned_type (unsigned_arg,
3598 /* Convert value-to-be-shifted to that type. */
3599 if (TREE_TYPE (op0) != result_type)
3600 op0 = cp_convert (result_type, op0);
3605 /* Comparison operations are shortened too but differently.
3606 They identify themselves by setting short_compare = 1. */
3610 /* Don't write &op0, etc., because that would prevent op0
3611 from being kept in a register.
3612 Instead, make copies of the our local variables and
3613 pass the copies by reference, then copy them back afterward. */
3614 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3615 enum tree_code xresultcode = resultcode;
3617 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3619 return cp_convert (boolean_type_node, val);
3620 op0 = xop0, op1 = xop1;
3622 resultcode = xresultcode;
3625 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3626 && warn_sign_compare
3627 /* Do not warn until the template is instantiated; we cannot
3628 bound the ranges of the arguments until that point. */
3629 && !processing_template_decl)
3631 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3632 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3634 int unsignedp0, unsignedp1;
3635 tree primop0 = get_narrower (op0, &unsignedp0);
3636 tree primop1 = get_narrower (op1, &unsignedp1);
3638 /* Check for comparison of different enum types. */
3639 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3640 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3641 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3642 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3644 warning (0, "comparison between types %q#T and %q#T",
3645 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3648 /* Give warnings for comparisons between signed and unsigned
3649 quantities that may fail. */
3650 /* Do the checking based on the original operand trees, so that
3651 casts will be considered, but default promotions won't be. */
3653 /* Do not warn if the comparison is being done in a signed type,
3654 since the signed type will only be chosen if it can represent
3655 all the values of the unsigned type. */
3656 if (!TYPE_UNSIGNED (result_type))
3658 /* Do not warn if both operands are unsigned. */
3659 else if (op0_signed == op1_signed)
3661 /* Do not warn if the signed quantity is an unsuffixed
3662 integer literal (or some static constant expression
3663 involving such literals or a conditional expression
3664 involving such literals) and it is non-negative. */
3665 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3666 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3668 /* Do not warn if the comparison is an equality operation,
3669 the unsigned quantity is an integral constant and it does
3670 not use the most significant bit of result_type. */
3671 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3672 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3673 && int_fits_type_p (orig_op1, c_common_signed_type
3675 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3676 && int_fits_type_p (orig_op0, c_common_signed_type
3680 warning (0, "comparison between signed and unsigned integer expressions");
3682 /* Warn if two unsigned values are being compared in a size
3683 larger than their original size, and one (and only one) is the
3684 result of a `~' operator. This comparison will always fail.
3686 Also warn if one operand is a constant, and the constant does not
3687 have all bits set that are set in the ~ operand when it is
3690 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3691 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3693 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3694 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3695 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3696 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3698 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3701 HOST_WIDE_INT constant, mask;
3705 if (host_integerp (primop0, 0))
3708 unsignedp = unsignedp1;
3709 constant = tree_low_cst (primop0, 0);
3714 unsignedp = unsignedp0;
3715 constant = tree_low_cst (primop1, 0);
3718 bits = TYPE_PRECISION (TREE_TYPE (primop));
3719 if (bits < TYPE_PRECISION (result_type)
3720 && bits < HOST_BITS_PER_LONG && unsignedp)
3722 mask = (~ (HOST_WIDE_INT) 0) << bits;
3723 if ((mask & constant) != mask)
3724 warning (0, "comparison of promoted ~unsigned with constant");
3727 else if (unsignedp0 && unsignedp1
3728 && (TYPE_PRECISION (TREE_TYPE (primop0))
3729 < TYPE_PRECISION (result_type))
3730 && (TYPE_PRECISION (TREE_TYPE (primop1))
3731 < TYPE_PRECISION (result_type)))
3732 warning (0, "comparison of promoted ~unsigned with unsigned");
3737 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3738 Then the expression will be built.
3739 It will be given type FINAL_TYPE if that is nonzero;
3740 otherwise, it will be given type RESULT_TYPE. */
3742 /* Issue warnings about peculiar, but valid, uses of NULL. */
3743 if (/* It's reasonable to use pointer values as operands of &&
3744 and ||, so NULL is no exception. */
3745 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3746 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3747 (orig_op0 == null_node
3748 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3749 /* Or vice versa. */
3750 || (orig_op1 == null_node
3751 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3752 /* Or, both are NULL and the operation was not a comparison. */
3753 || (orig_op0 == null_node && orig_op1 == null_node
3754 && code != EQ_EXPR && code != NE_EXPR)))
3755 /* Some sort of arithmetic operation involving NULL was
3756 performed. Note that pointer-difference and pointer-addition
3757 have already been handled above, and so we don't end up here in
3759 warning (0, "NULL used in arithmetic");
3763 if (TREE_TYPE (op0) != result_type)
3764 op0 = cp_convert (result_type, op0);
3765 if (TREE_TYPE (op1) != result_type)
3766 op1 = cp_convert (result_type, op1);
3768 if (op0 == error_mark_node || op1 == error_mark_node)
3769 return error_mark_node;
3772 if (build_type == NULL_TREE)
3773 build_type = result_type;
3775 result = build2 (resultcode, build_type, op0, op1);
3776 result = fold_if_not_in_template (result);
3777 if (final_type != 0)
3778 result = cp_convert (final_type, result);
3782 /* Return a tree for the sum or difference (RESULTCODE says which)
3783 of pointer PTROP and integer INTOP. */
3786 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3788 tree res_type = TREE_TYPE (ptrop);
3790 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3791 in certain circumstance (when it's valid to do so). So we need
3792 to make sure it's complete. We don't need to check here, if we
3793 can actually complete it at all, as those checks will be done in
3794 pointer_int_sum() anyway. */
3795 complete_type (TREE_TYPE (res_type));
3797 return pointer_int_sum (resultcode, ptrop,
3798 fold_if_not_in_template (intop));
3801 /* Return a tree for the difference of pointers OP0 and OP1.
3802 The resulting tree has type int. */
3805 pointer_diff (tree op0, tree op1, tree ptrtype)
3808 tree restype = ptrdiff_type_node;
3809 tree target_type = TREE_TYPE (ptrtype);
3811 if (!complete_type_or_else (target_type, NULL_TREE))
3812 return error_mark_node;
3814 if (pedantic || warn_pointer_arith)
3816 if (TREE_CODE (target_type) == VOID_TYPE)
3817 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3818 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3819 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3820 if (TREE_CODE (target_type) == METHOD_TYPE)
3821 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3824 /* First do the subtraction as integers;
3825 then drop through to build the divide operator. */
3827 op0 = cp_build_binary_op (MINUS_EXPR,
3828 cp_convert (restype, op0),
3829 cp_convert (restype, op1));
3831 /* This generates an error if op1 is a pointer to an incomplete type. */
3832 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3833 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3835 op1 = (TYPE_PTROB_P (ptrtype)
3836 ? size_in_bytes (target_type)
3837 : integer_one_node);
3839 /* Do the division. */
3841 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3842 return fold_if_not_in_template (result);
3845 /* Construct and perhaps optimize a tree representation
3846 for a unary operation. CODE, a tree_code, specifies the operation
3847 and XARG is the operand. */
3850 build_x_unary_op (enum tree_code code, tree xarg)
3852 tree orig_expr = xarg;
3856 if (processing_template_decl)
3858 if (type_dependent_expression_p (xarg))
3859 return build_min_nt (code, xarg, NULL_TREE);
3861 xarg = build_non_dependent_expr (xarg);
3866 /* [expr.unary.op] says:
3868 The address of an object of incomplete type can be taken.
3870 (And is just the ordinary address operator, not an overloaded
3871 "operator &".) However, if the type is a template
3872 specialization, we must complete the type at this point so that
3873 an overloaded "operator &" will be available if required. */
3874 if (code == ADDR_EXPR
3875 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3876 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3877 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3878 || (TREE_CODE (xarg) == OFFSET_REF)))
3879 /* Don't look for a function. */;
3881 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3882 /*overloaded_p=*/NULL);
3883 if (!exp && code == ADDR_EXPR)
3885 /* A pointer to member-function can be formed only by saying
3887 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3888 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3890 if (TREE_CODE (xarg) != OFFSET_REF
3891 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3893 error ("invalid use of %qE to form a pointer-to-member-function",
3895 if (TREE_CODE (xarg) != OFFSET_REF)
3896 inform (" a qualified-id is required");
3897 return error_mark_node;
3901 error ("parentheses around %qE cannot be used to form a"
3902 " pointer-to-member-function",
3904 PTRMEM_OK_P (xarg) = 1;
3908 if (TREE_CODE (xarg) == OFFSET_REF)
3910 ptrmem = PTRMEM_OK_P (xarg);
3912 if (!ptrmem && !flag_ms_extensions
3913 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3915 /* A single non-static member, make sure we don't allow a
3916 pointer-to-member. */
3917 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3918 TREE_OPERAND (xarg, 0),
3919 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3920 PTRMEM_OK_P (xarg) = ptrmem;
3923 else if (TREE_CODE (xarg) == TARGET_EXPR)
3924 warning (0, "taking address of temporary");
3925 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3928 if (processing_template_decl && exp != error_mark_node)
3929 exp = build_min_non_dep (code, exp, orig_expr,
3930 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3931 if (TREE_CODE (exp) == ADDR_EXPR)
3932 PTRMEM_OK_P (exp) = ptrmem;
3936 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3937 constants, where a null value is represented by an INTEGER_CST of
3941 cp_truthvalue_conversion (tree expr)
3943 tree type = TREE_TYPE (expr);
3944 if (TYPE_PTRMEM_P (type))
3945 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3947 return c_common_truthvalue_conversion (expr);
3950 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3953 condition_conversion (tree expr)
3956 if (processing_template_decl)
3958 t = perform_implicit_conversion (boolean_type_node, expr);
3959 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3963 /* Return an ADDR_EXPR giving the address of T. This function
3964 attempts no optimizations or simplifications; it is a low-level
3968 build_address (tree t)
3972 if (error_operand_p (t) || !cxx_mark_addressable (t))
3973 return error_mark_node;
3975 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3980 /* Return a NOP_EXPR converting EXPR to TYPE. */
3983 build_nop (tree type, tree expr)
3985 if (type == error_mark_node || error_operand_p (expr))
3987 return build1 (NOP_EXPR, type, expr);
3990 /* C++: Must handle pointers to members.
3992 Perhaps type instantiation should be extended to handle conversion
3993 from aggregates to types we don't yet know we want? (Or are those
3994 cases typically errors which should be reported?)
3996 NOCONVERT nonzero suppresses the default promotions
3997 (such as from short to int). */
4000 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4002 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4005 const char *errstring = NULL;
4007 const char *invalid_op_diag;
4009 if (arg == error_mark_node)
4010 return error_mark_node;
4012 if ((invalid_op_diag
4013 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4018 error (invalid_op_diag);
4019 return error_mark_node;
4024 case UNARY_PLUS_EXPR:
4027 int flags = WANT_ARITH | WANT_ENUM;
4028 /* Unary plus (but not unary minus) is allowed on pointers. */
4029 if (code == UNARY_PLUS_EXPR)
4030 flags |= WANT_POINTER;
4031 arg = build_expr_type_conversion (flags, arg, true);
4033 errstring = (code == NEGATE_EXPR
4034 ? "wrong type argument to unary minus"
4035 : "wrong type argument to unary plus");
4038 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4039 arg = perform_integral_promotions (arg);
4041 /* Make sure the result is not an lvalue: a unary plus or minus
4042 expression is always a rvalue. */
4049 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4053 arg = default_conversion (arg);
4055 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4058 errstring = "wrong type argument to bit-complement";
4059 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4060 arg = perform_integral_promotions (arg);
4064 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4065 errstring = "wrong type argument to abs";
4066 else if (!noconvert)
4067 arg = default_conversion (arg);
4071 /* Conjugating a real value is a no-op, but allow it anyway. */
4072 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4073 errstring = "wrong type argument to conjugation";
4074 else if (!noconvert)
4075 arg = default_conversion (arg);
4078 case TRUTH_NOT_EXPR:
4079 arg = perform_implicit_conversion (boolean_type_node, arg);
4080 val = invert_truthvalue (arg);
4081 if (arg != error_mark_node)
4083 errstring = "in argument to unary !";
4090 if (TREE_CODE (arg) == COMPLEX_CST)
4091 return TREE_REALPART (arg);
4092 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4094 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4095 return fold_if_not_in_template (arg);
4101 if (TREE_CODE (arg) == COMPLEX_CST)
4102 return TREE_IMAGPART (arg);
4103 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4105 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4106 return fold_if_not_in_template (arg);
4109 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4111 case PREINCREMENT_EXPR:
4112 case POSTINCREMENT_EXPR:
4113 case PREDECREMENT_EXPR:
4114 case POSTDECREMENT_EXPR:
4115 /* Handle complex lvalues (when permitted)
4116 by reduction to simpler cases. */
4118 val = unary_complex_lvalue (code, arg);
4122 /* Increment or decrement the real part of the value,
4123 and don't change the imaginary part. */
4124 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4128 arg = stabilize_reference (arg);
4129 real = build_unary_op (REALPART_EXPR, arg, 1);
4130 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4131 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4132 build_unary_op (code, real, 1), imag);
4135 /* Report invalid types. */
4137 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4140 if (code == PREINCREMENT_EXPR)
4141 errstring ="no pre-increment operator for type";
4142 else if (code == POSTINCREMENT_EXPR)
4143 errstring ="no post-increment operator for type";
4144 else if (code == PREDECREMENT_EXPR)
4145 errstring ="no pre-decrement operator for type";
4147 errstring ="no post-decrement operator for type";
4151 /* Report something read-only. */
4153 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4154 || TREE_READONLY (arg))
4155 readonly_error (arg, ((code == PREINCREMENT_EXPR
4156 || code == POSTINCREMENT_EXPR)
4157 ? "increment" : "decrement"),
4162 tree result_type = TREE_TYPE (arg);
4164 arg = get_unwidened (arg, 0);
4165 argtype = TREE_TYPE (arg);
4167 /* ARM $5.2.5 last annotation says this should be forbidden. */
4168 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4169 pedwarn ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4170 ? G_("ISO C++ forbids incrementing an enum")
4171 : G_("ISO C++ forbids decrementing an enum"));
4173 /* Compute the increment. */
4175 if (TREE_CODE (argtype) == POINTER_TYPE)
4177 tree type = complete_type (TREE_TYPE (argtype));
4179 if (!COMPLETE_OR_VOID_TYPE_P (type))
4180 error (((code == PREINCREMENT_EXPR
4181 || code == POSTINCREMENT_EXPR))
4182 ? G_("cannot increment a pointer to incomplete type %qT")
4183 : G_("cannot decrement a pointer to incomplete type %qT"),
4184 TREE_TYPE (argtype));
4185 else if ((pedantic || warn_pointer_arith)
4186 && !TYPE_PTROB_P (argtype))
4187 pedwarn ((code == PREINCREMENT_EXPR
4188 || code == POSTINCREMENT_EXPR)
4189 ? G_("ISO C++ forbids incrementing a pointer of type %qT")
4190 : G_("ISO C++ forbids decrementing a pointer of type %qT"),
4192 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4195 inc = integer_one_node;
4197 inc = cp_convert (argtype, inc);
4199 /* Handle incrementing a cast-expression. */
4201 switch (TREE_CODE (arg))
4206 case FIX_TRUNC_EXPR:
4208 tree incremented, modify, value, compound;
4209 if (! lvalue_p (arg) && pedantic)
4210 pedwarn ("cast to non-reference type used as lvalue");
4211 arg = stabilize_reference (arg);
4212 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4215 value = save_expr (arg);
4216 incremented = build2 (((code == PREINCREMENT_EXPR
4217 || code == POSTINCREMENT_EXPR)
4218 ? PLUS_EXPR : MINUS_EXPR),
4219 argtype, value, inc);
4221 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4222 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4225 /* Eliminate warning about unused result of + or -. */
4226 TREE_NO_WARNING (compound) = 1;
4234 /* Complain about anything else that is not a true lvalue. */
4235 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4236 || code == POSTINCREMENT_EXPR)
4237 ? lv_increment : lv_decrement)))
4238 return error_mark_node;
4240 /* Forbid using -- on `bool'. */
4241 if (same_type_p (TREE_TYPE (arg), boolean_type_node))
4243 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4245 error ("invalid use of %<--%> on bool variable %qD", arg);
4246 return error_mark_node;
4248 val = boolean_increment (code, arg);
4251 val = build2 (code, TREE_TYPE (arg), arg, inc);
4253 TREE_SIDE_EFFECTS (val) = 1;
4254 return cp_convert (result_type, val);
4258 /* Note that this operation never does default_conversion
4259 regardless of NOCONVERT. */
4261 argtype = lvalue_type (arg);
4263 if (TREE_CODE (arg) == OFFSET_REF)
4266 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4268 tree type = build_pointer_type (TREE_TYPE (argtype));
4269 arg = build1 (CONVERT_EXPR, type, arg);
4272 else if (pedantic && DECL_MAIN_P (arg))
4274 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4276 /* Let &* cancel out to simplify resulting code. */
4277 if (TREE_CODE (arg) == INDIRECT_REF)
4279 /* We don't need to have `current_class_ptr' wrapped in a
4280 NON_LVALUE_EXPR node. */
4281 if (arg == current_class_ref)
4282 return current_class_ptr;
4284 arg = TREE_OPERAND (arg, 0);
4285 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4287 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4288 arg = build1 (CONVERT_EXPR, type, arg);
4291 /* Don't let this be an lvalue. */
4296 /* Uninstantiated types are all functions. Taking the
4297 address of a function is a no-op, so just return the
4300 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4301 || !IDENTIFIER_OPNAME_P (arg));
4303 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4304 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4306 /* They're trying to take the address of a unique non-static
4307 member function. This is ill-formed (except in MS-land),
4308 but let's try to DTRT.
4309 Note: We only handle unique functions here because we don't
4310 want to complain if there's a static overload; non-unique
4311 cases will be handled by instantiate_type. But we need to
4312 handle this case here to allow casts on the resulting PMF.
4313 We could defer this in non-MS mode, but it's easier to give
4314 a useful error here. */
4316 /* Inside constant member functions, the `this' pointer
4317 contains an extra const qualifier. TYPE_MAIN_VARIANT
4318 is used here to remove this const from the diagnostics
4319 and the created OFFSET_REF. */
4320 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4321 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4324 if (! flag_ms_extensions)
4326 tree name = DECL_NAME (fn);
4327 if (current_class_type
4328 && TREE_OPERAND (arg, 0) == current_class_ref)
4329 /* An expression like &memfn. */
4330 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4331 " or parenthesized non-static member function to form"
4332 " a pointer to member function. Say %<&%T::%D%>",
4335 pedwarn ("ISO C++ forbids taking the address of a bound member"
4336 " function to form a pointer to member function."
4340 arg = build_offset_ref (base, fn, /*address_p=*/true);
4344 if (type_unknown_p (arg))
4345 return build1 (ADDR_EXPR, unknown_type_node, arg);
4347 /* Handle complex lvalues (when permitted)
4348 by reduction to simpler cases. */
4349 val = unary_complex_lvalue (code, arg);
4353 switch (TREE_CODE (arg))
4358 case FIX_TRUNC_EXPR:
4359 if (! lvalue_p (arg) && pedantic)
4360 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4364 arg = BASELINK_FUNCTIONS (arg);
4368 arg = OVL_CURRENT (arg);
4372 /* Turn a reference to a non-static data member into a
4373 pointer-to-member. */
4378 if (!PTRMEM_OK_P (arg))
4379 return build_unary_op (code, arg, 0);
4381 t = TREE_OPERAND (arg, 1);
4382 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4384 error ("cannot create pointer to reference member %qD", t);
4385 return error_mark_node;
4388 type = build_ptrmem_type (context_for_name_lookup (t),
4390 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4398 /* Anything not already handled and not a true memory reference
4400 if (TREE_CODE (argtype) != FUNCTION_TYPE
4401 && TREE_CODE (argtype) != METHOD_TYPE
4402 && TREE_CODE (arg) != OFFSET_REF
4403 && !lvalue_or_else (arg, lv_addressof))
4404 return error_mark_node;
4406 if (argtype != error_mark_node)
4407 argtype = build_pointer_type (argtype);
4409 /* In a template, we are processing a non-dependent expression
4410 so we can just form an ADDR_EXPR with the correct type. */
4411 if (processing_template_decl)
4413 val = build_address (arg);
4414 if (TREE_CODE (arg) == OFFSET_REF)
4415 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4419 if (TREE_CODE (arg) != COMPONENT_REF)
4421 val = build_address (arg);
4422 if (TREE_CODE (arg) == OFFSET_REF)
4423 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4425 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4427 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4429 /* We can only get here with a single static member
4431 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4432 && DECL_STATIC_FUNCTION_P (fn));
4434 val = build_address (fn);
4435 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4436 /* Do not lose object's side effects. */
4437 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4438 TREE_OPERAND (arg, 0), val);
4440 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4442 error ("attempt to take address of bit-field structure member %qD",
4443 TREE_OPERAND (arg, 1));
4444 return error_mark_node;
4448 tree object = TREE_OPERAND (arg, 0);
4449 tree field = TREE_OPERAND (arg, 1);
4450 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4451 (TREE_TYPE (object), decl_type_context (field)));
4452 val = build_address (arg);
4455 if (TREE_CODE (argtype) == POINTER_TYPE
4456 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4458 build_ptrmemfunc_type (argtype);
4459 val = build_ptrmemfunc (argtype, val, 0,
4460 /*c_cast_p=*/false);
4472 argtype = TREE_TYPE (arg);
4473 return fold_if_not_in_template (build1 (code, argtype, arg));
4476 error ("%s", errstring);
4477 return error_mark_node;
4480 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4481 for certain kinds of expressions which are not really lvalues
4482 but which we can accept as lvalues.
4484 If ARG is not a kind of expression we can handle, return
4488 unary_complex_lvalue (enum tree_code code, tree arg)
4490 /* Inside a template, making these kinds of adjustments is
4491 pointless; we are only concerned with the type of the
4493 if (processing_template_decl)
4496 /* Handle (a, b) used as an "lvalue". */
4497 if (TREE_CODE (arg) == COMPOUND_EXPR)
4499 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4500 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4501 TREE_OPERAND (arg, 0), real_result);
4504 /* Handle (a ? b : c) used as an "lvalue". */
4505 if (TREE_CODE (arg) == COND_EXPR
4506 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4507 return rationalize_conditional_expr (code, arg);
4509 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4510 if (TREE_CODE (arg) == MODIFY_EXPR
4511 || TREE_CODE (arg) == PREINCREMENT_EXPR
4512 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4514 tree lvalue = TREE_OPERAND (arg, 0);
4515 if (TREE_SIDE_EFFECTS (lvalue))
4517 lvalue = stabilize_reference (lvalue);
4518 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4519 lvalue, TREE_OPERAND (arg, 1));
4521 return unary_complex_lvalue
4522 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4525 if (code != ADDR_EXPR)
4528 /* Handle (a = b) used as an "lvalue" for `&'. */
4529 if (TREE_CODE (arg) == MODIFY_EXPR
4530 || TREE_CODE (arg) == INIT_EXPR)
4532 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4533 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4535 TREE_NO_WARNING (arg) = 1;
4539 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4540 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4541 || TREE_CODE (arg) == OFFSET_REF)
4544 /* We permit compiler to make function calls returning
4545 objects of aggregate type look like lvalues. */
4549 if (TREE_CODE (targ) == SAVE_EXPR)
4550 targ = TREE_OPERAND (targ, 0);
4552 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4554 if (TREE_CODE (arg) == SAVE_EXPR)
4557 targ = build_cplus_new (TREE_TYPE (arg), arg);
4558 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4561 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4562 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4563 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4566 /* Don't let anything else be handled specially. */
4570 /* Mark EXP saying that we need to be able to take the
4571 address of it; it should not be allocated in a register.
4572 Value is true if successful.
4574 C++: we do not allow `current_class_ptr' to be addressable. */
4577 cxx_mark_addressable (tree exp)
4582 switch (TREE_CODE (x))
4589 x = TREE_OPERAND (x, 0);
4593 if (x == current_class_ptr)
4595 error ("cannot take the address of %<this%>, which is an rvalue expression");
4596 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4602 /* Caller should not be trying to mark initialized
4603 constant fields addressable. */
4604 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4605 || DECL_IN_AGGR_P (x) == 0
4607 || DECL_EXTERNAL (x));
4612 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4613 && !DECL_ARTIFICIAL (x))
4615 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4618 ("address of explicit register variable %qD requested", x);
4621 else if (extra_warnings)
4623 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4625 TREE_ADDRESSABLE (x) = 1;
4629 TREE_ADDRESSABLE (x) = 1;
4633 TREE_ADDRESSABLE (x) = 1;
4637 TREE_ADDRESSABLE (x) = 1;
4638 cxx_mark_addressable (TREE_OPERAND (x, 0));
4646 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4649 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4651 tree orig_ifexp = ifexp;
4652 tree orig_op1 = op1;
4653 tree orig_op2 = op2;
4656 if (processing_template_decl)
4658 /* The standard says that the expression is type-dependent if
4659 IFEXP is type-dependent, even though the eventual type of the
4660 expression doesn't dependent on IFEXP. */
4661 if (type_dependent_expression_p (ifexp)
4662 /* As a GNU extension, the middle operand may be omitted. */
4663 || (op1 && type_dependent_expression_p (op1))
4664 || type_dependent_expression_p (op2))
4665 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4666 ifexp = build_non_dependent_expr (ifexp);
4668 op1 = build_non_dependent_expr (op1);
4669 op2 = build_non_dependent_expr (op2);
4672 expr = build_conditional_expr (ifexp, op1, op2);
4673 if (processing_template_decl && expr != error_mark_node)
4674 return build_min_non_dep (COND_EXPR, expr,
4675 orig_ifexp, orig_op1, orig_op2);
4679 /* Given a list of expressions, return a compound expression
4680 that performs them all and returns the value of the last of them. */
4682 tree build_x_compound_expr_from_list (tree list, const char *msg)
4684 tree expr = TREE_VALUE (list);
4686 if (TREE_CHAIN (list))
4689 pedwarn ("%s expression list treated as compound expression", msg);
4691 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4692 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4698 /* Handle overloading of the ',' operator when needed. */
4701 build_x_compound_expr (tree op1, tree op2)
4704 tree orig_op1 = op1;
4705 tree orig_op2 = op2;
4707 if (processing_template_decl)
4709 if (type_dependent_expression_p (op1)
4710 || type_dependent_expression_p (op2))
4711 return build_min_nt (COMPOUND_EXPR, op1, op2);
4712 op1 = build_non_dependent_expr (op1);
4713 op2 = build_non_dependent_expr (op2);
4716 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4717 /*overloaded_p=*/NULL);
4719 result = build_compound_expr (op1, op2);
4721 if (processing_template_decl && result != error_mark_node)
4722 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4727 /* Build a compound expression. */
4730 build_compound_expr (tree lhs, tree rhs)
4732 lhs = convert_to_void (lhs, "left-hand operand of comma");
4734 if (lhs == error_mark_node || rhs == error_mark_node)
4735 return error_mark_node;
4737 if (TREE_CODE (rhs) == TARGET_EXPR)
4739 /* If the rhs is a TARGET_EXPR, then build the compound
4740 expression inside the target_expr's initializer. This
4741 helps the compiler to eliminate unnecessary temporaries. */
4742 tree init = TREE_OPERAND (rhs, 1);
4744 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4745 TREE_OPERAND (rhs, 1) = init;
4750 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4753 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4754 casts away constness. DIAG_FN gives the function to call if we
4755 need to issue a diagnostic; if it is NULL, no diagnostic will be
4756 issued. DESCRIPTION explains what operation is taking place. */
4759 check_for_casting_away_constness (tree src_type, tree dest_type,
4760 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4761 const char *description)
4763 if (diag_fn && casts_away_constness (src_type, dest_type))
4764 diag_fn ("%s from type %qT to type %qT casts away constness",
4765 description, src_type, dest_type);
4768 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4769 (another pointer-to-member type in the same hierarchy) and return
4770 the converted expression. If ALLOW_INVERSE_P is permitted, a
4771 pointer-to-derived may be converted to pointer-to-base; otherwise,
4772 only the other direction is permitted. If C_CAST_P is true, this
4773 conversion is taking place as part of a C-style cast. */
4776 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4779 if (TYPE_PTRMEM_P (type))
4783 if (TREE_CODE (expr) == PTRMEM_CST)
4784 expr = cplus_expand_constant (expr);
4785 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4786 TYPE_PTRMEM_CLASS_TYPE (type),
4789 if (!integer_zerop (delta))
4790 expr = cp_build_binary_op (PLUS_EXPR,
4791 build_nop (ptrdiff_type_node, expr),
4793 return build_nop (type, expr);
4796 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4797 allow_inverse_p, c_cast_p);
4800 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4801 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4802 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4805 ignore_overflows (tree expr, tree orig)
4807 if (TREE_CODE (expr) == INTEGER_CST
4808 && CONSTANT_CLASS_P (orig)
4809 && TREE_CODE (orig) != STRING_CST
4810 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4811 || TREE_CONSTANT_OVERFLOW (expr)
4812 != TREE_CONSTANT_OVERFLOW (orig)))
4814 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4815 /* Ensure constant sharing. */
4816 expr = build_int_cst_wide (TREE_TYPE (expr),
4817 TREE_INT_CST_LOW (expr),
4818 TREE_INT_CST_HIGH (expr));
4821 /* Avoid clobbering a shared constant. */
4822 expr = copy_node (expr);
4823 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4824 TREE_CONSTANT_OVERFLOW (expr)
4825 = TREE_CONSTANT_OVERFLOW (orig);
4831 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4832 this static_cast is being attempted as one of the possible casts
4833 allowed by a C-style cast. (In that case, accessibility of base
4834 classes is not considered, and it is OK to cast away
4835 constness.) Return the result of the cast. *VALID_P is set to
4836 indicate whether or not the cast was valid. */
4839 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4845 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4848 /* Assume the cast is valid. */
4851 intype = TREE_TYPE (expr);
4853 /* Save casted types in the function's used types hash table. */
4854 used_types_insert (type);
4856 /* Determine what to do when casting away constness. */
4859 /* C-style casts are allowed to cast away constness. With
4860 WARN_CAST_QUAL, we still want to issue a warning. */
4861 diag_fn = warn_cast_qual ? warning0 : NULL;
4866 /* A static_cast may not cast away constness. */
4868 desc = "static_cast";
4871 /* [expr.static.cast]
4873 An lvalue of type "cv1 B", where B is a class type, can be cast
4874 to type "reference to cv2 D", where D is a class derived (clause
4875 _class.derived_) from B, if a valid standard conversion from
4876 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4877 same cv-qualification as, or greater cv-qualification than, cv1,
4878 and B is not a virtual base class of D. */
4879 /* We check this case before checking the validity of "TYPE t =
4880 EXPR;" below because for this case:
4883 struct D : public B { D(const B&); };
4885 void f() { static_cast<const D&>(b); }
4887 we want to avoid constructing a new D. The standard is not
4888 completely clear about this issue, but our interpretation is
4889 consistent with other compilers. */
4890 if (TREE_CODE (type) == REFERENCE_TYPE
4891 && CLASS_TYPE_P (TREE_TYPE (type))
4892 && CLASS_TYPE_P (intype)
4893 && real_lvalue_p (expr)
4894 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4895 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4896 build_pointer_type (TYPE_MAIN_VARIANT
4897 (TREE_TYPE (type))))
4899 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4903 /* There is a standard conversion from "D*" to "B*" even if "B"
4904 is ambiguous or inaccessible. If this is really a
4905 static_cast, then we check both for inaccessibility and
4906 ambiguity. However, if this is a static_cast being performed
4907 because the user wrote a C-style cast, then accessibility is
4909 base = lookup_base (TREE_TYPE (type), intype,
4910 c_cast_p ? ba_unique : ba_check,
4913 /* Convert from "B*" to "D*". This function will check that "B"
4914 is not a virtual base of "D". */
4915 expr = build_base_path (MINUS_EXPR, build_address (expr),
4916 base, /*nonnull=*/false);
4917 /* Convert the pointer to a reference -- but then remember that
4918 there are no expressions with reference type in C++. */
4919 return convert_from_reference (build_nop (type, expr));
4924 /* [expr.static.cast]
4926 An expression e can be explicitly converted to a type T using a
4927 static_cast of the form static_cast<T>(e) if the declaration T
4928 t(e);" is well-formed, for some invented temporary variable
4930 result = perform_direct_initialization_if_possible (type, expr,
4934 result = convert_from_reference (result);
4936 /* Ignore any integer overflow caused by the cast. */
4937 result = ignore_overflows (result, orig);
4939 /* [expr.static.cast]
4941 If T is a reference type, the result is an lvalue; otherwise,
4942 the result is an rvalue. */
4943 if (TREE_CODE (type) != REFERENCE_TYPE)
4944 result = rvalue (result);
4948 /* [expr.static.cast]
4950 Any expression can be explicitly converted to type cv void. */
4951 if (TREE_CODE (type) == VOID_TYPE)
4952 return convert_to_void (expr, /*implicit=*/NULL);
4954 /* [expr.static.cast]
4956 The inverse of any standard conversion sequence (clause _conv_),
4957 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4958 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4959 (_conv.bool_) conversions, can be performed explicitly using
4960 static_cast subject to the restriction that the explicit
4961 conversion does not cast away constness (_expr.const.cast_), and
4962 the following additional rules for specific cases: */
4963 /* For reference, the conversions not excluded are: integral
4964 promotions, floating point promotion, integral conversions,
4965 floating point conversions, floating-integral conversions,
4966 pointer conversions, and pointer to member conversions. */
4969 A value of integral _or enumeration_ type can be explicitly
4970 converted to an enumeration type. */
4971 /* The effect of all that is that any conversion between any two
4972 types which are integral, floating, or enumeration types can be
4974 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
4975 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
4977 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
4979 /* Ignore any integer overflow caused by the cast. */
4980 expr = ignore_overflows (expr, orig);
4984 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
4985 && CLASS_TYPE_P (TREE_TYPE (type))
4986 && CLASS_TYPE_P (TREE_TYPE (intype))
4987 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
4988 (TREE_TYPE (intype))),
4989 build_pointer_type (TYPE_MAIN_VARIANT
4990 (TREE_TYPE (type)))))
4995 check_for_casting_away_constness (intype, type, diag_fn, desc);
4996 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
4997 c_cast_p ? ba_unique : ba_check,
4999 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5002 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5003 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5010 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5011 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5013 if (TYPE_PTRMEM_P (type))
5015 t1 = (build_ptrmem_type
5017 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5018 t2 = (build_ptrmem_type
5020 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5027 if (can_convert (t1, t2))
5030 check_for_casting_away_constness (intype, type, diag_fn,
5032 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5037 /* [expr.static.cast]
5039 An rvalue of type "pointer to cv void" can be explicitly
5040 converted to a pointer to object type. A value of type pointer
5041 to object converted to "pointer to cv void" and back to the
5042 original pointer type will have its original value. */
5043 if (TREE_CODE (intype) == POINTER_TYPE
5044 && VOID_TYPE_P (TREE_TYPE (intype))
5045 && TYPE_PTROB_P (type))
5048 check_for_casting_away_constness (intype, type, diag_fn, desc);
5049 return build_nop (type, expr);
5053 return error_mark_node;
5056 /* Return an expression representing static_cast<TYPE>(EXPR). */
5059 build_static_cast (tree type, tree expr)
5064 if (type == error_mark_node || expr == error_mark_node)
5065 return error_mark_node;
5067 if (processing_template_decl)
5069 expr = build_min (STATIC_CAST_EXPR, type, expr);
5070 /* We don't know if it will or will not have side effects. */
5071 TREE_SIDE_EFFECTS (expr) = 1;
5072 return convert_from_reference (expr);
5075 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5076 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5077 if (TREE_CODE (type) != REFERENCE_TYPE
5078 && TREE_CODE (expr) == NOP_EXPR
5079 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5080 expr = TREE_OPERAND (expr, 0);
5082 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5086 error ("invalid static_cast from type %qT to type %qT",
5087 TREE_TYPE (expr), type);
5088 return error_mark_node;
5091 /* EXPR is an expression with member function or pointer-to-member
5092 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5093 not permitted by ISO C++, but we accept it in some modes. If we
5094 are not in one of those modes, issue a diagnostic. Return the
5095 converted expression. */
5098 convert_member_func_to_ptr (tree type, tree expr)
5103 intype = TREE_TYPE (expr);
5104 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5105 || TREE_CODE (intype) == METHOD_TYPE);
5107 if (pedantic || warn_pmf2ptr)
5108 pedwarn ("converting from %qT to %qT", intype, type);
5110 if (TREE_CODE (intype) == METHOD_TYPE)
5111 expr = build_addr_func (expr);
5112 else if (TREE_CODE (expr) == PTRMEM_CST)
5113 expr = build_address (PTRMEM_CST_MEMBER (expr));
5116 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5117 decl = build_address (decl);
5118 expr = get_member_function_from_ptrfunc (&decl, expr);
5121 return build_nop (type, expr);
5124 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5125 If C_CAST_P is true, this reinterpret cast is being done as part of
5126 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5127 indicate whether or not reinterpret_cast was valid. */
5130 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5135 /* Assume the cast is invalid. */
5139 if (type == error_mark_node || error_operand_p (expr))
5140 return error_mark_node;
5142 intype = TREE_TYPE (expr);
5144 /* Save casted types in the function's used types hash table. */
5145 used_types_insert (type);
5147 /* [expr.reinterpret.cast]
5148 An lvalue expression of type T1 can be cast to the type
5149 "reference to T2" if an expression of type "pointer to T1" can be
5150 explicitly converted to the type "pointer to T2" using a
5151 reinterpret_cast. */
5152 if (TREE_CODE (type) == REFERENCE_TYPE)
5154 if (! real_lvalue_p (expr))
5156 error ("invalid cast of an rvalue expression of type "
5159 return error_mark_node;
5162 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5163 "B" are related class types; the reinterpret_cast does not
5164 adjust the pointer. */
5165 if (TYPE_PTR_P (intype)
5166 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5167 COMPARE_BASE | COMPARE_DERIVED)))
5168 warning (0, "casting %qT to %qT does not dereference pointer",
5171 expr = build_unary_op (ADDR_EXPR, expr, 0);
5172 if (expr != error_mark_node)
5173 expr = build_reinterpret_cast_1
5174 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5176 if (expr != error_mark_node)
5177 expr = build_indirect_ref (expr, 0);
5181 /* As a G++ extension, we consider conversions from member
5182 functions, and pointers to member functions to
5183 pointer-to-function and pointer-to-void types. If
5184 -Wno-pmf-conversions has not been specified,
5185 convert_member_func_to_ptr will issue an error message. */
5186 if ((TYPE_PTRMEMFUNC_P (intype)
5187 || TREE_CODE (intype) == METHOD_TYPE)
5188 && TYPE_PTR_P (type)
5189 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5190 || VOID_TYPE_P (TREE_TYPE (type))))
5191 return convert_member_func_to_ptr (type, expr);
5193 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5194 array-to-pointer, and function-to-pointer conversions are
5196 expr = decay_conversion (expr);
5198 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5199 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5200 if (TREE_CODE (expr) == NOP_EXPR
5201 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5202 expr = TREE_OPERAND (expr, 0);
5204 if (error_operand_p (expr))
5205 return error_mark_node;
5207 intype = TREE_TYPE (expr);
5209 /* [expr.reinterpret.cast]
5210 A pointer can be converted to any integral type large enough to
5212 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5214 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5215 pedwarn ("cast from %qT to %qT loses precision",
5218 /* [expr.reinterpret.cast]
5219 A value of integral or enumeration type can be explicitly
5220 converted to a pointer. */
5221 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5224 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5225 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5226 return fold_if_not_in_template (build_nop (type, expr));
5227 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5228 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5233 check_for_casting_away_constness (intype, type, error,
5234 "reinterpret_cast");
5235 /* Warn about possible alignment problems. */
5236 if (STRICT_ALIGNMENT && warn_cast_align
5237 && !VOID_TYPE_P (type)
5238 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5239 && COMPLETE_TYPE_P (TREE_TYPE (type))
5240 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5241 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5242 warning (0, "cast from %qT to %qT increases required alignment of "
5246 /* We need to strip nops here, because the frontend likes to
5247 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5249 strict_aliasing_warning (intype, type, sexpr);
5251 return fold_if_not_in_template (build_nop (type, expr));
5253 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5254 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5257 /* Only issue a warning, as we have always supported this
5258 where possible, and it is necessary in some cases. DR 195
5259 addresses this issue, but as of 2004/10/26 is still in
5261 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5262 return fold_if_not_in_template (build_nop (type, expr));
5264 else if (TREE_CODE (type) == VECTOR_TYPE)
5265 return fold_if_not_in_template (convert_to_vector (type, expr));
5266 else if (TREE_CODE (intype) == VECTOR_TYPE)
5267 return fold_if_not_in_template (convert_to_integer (type, expr));
5272 error ("invalid cast from type %qT to type %qT", intype, type);
5273 return error_mark_node;
5276 return cp_convert (type, expr);
5280 build_reinterpret_cast (tree type, tree expr)
5282 if (type == error_mark_node || expr == error_mark_node)
5283 return error_mark_node;
5285 if (processing_template_decl)
5287 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5289 if (!TREE_SIDE_EFFECTS (t)
5290 && type_dependent_expression_p (expr))
5291 /* There might turn out to be side effects inside expr. */
5292 TREE_SIDE_EFFECTS (t) = 1;
5293 return convert_from_reference (t);
5296 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5300 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5301 return an appropriate expression. Otherwise, return
5302 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5303 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5304 performing a C-style cast, its value upon return will indicate
5305 whether or not the conversion succeeded. */
5308 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5312 tree reference_type;
5314 /* Callers are responsible for handling error_mark_node as a
5315 destination type. */
5316 gcc_assert (dst_type != error_mark_node);
5317 /* In a template, callers should be building syntactic
5318 representations of casts, not using this machinery. */
5319 gcc_assert (!processing_template_decl);
5321 /* Assume the conversion is invalid. */
5325 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5328 error ("invalid use of const_cast with type %qT, "
5329 "which is not a pointer, "
5330 "reference, nor a pointer-to-data-member type", dst_type);
5331 return error_mark_node;
5334 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5337 error ("invalid use of const_cast with type %qT, which is a pointer "
5338 "or reference to a function type", dst_type);
5339 return error_mark_node;
5342 /* Save casted types in the function's used types hash table. */
5343 used_types_insert (dst_type);
5345 src_type = TREE_TYPE (expr);
5346 /* Expressions do not really have reference types. */
5347 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5348 src_type = TREE_TYPE (src_type);
5350 /* [expr.const.cast]
5352 An lvalue of type T1 can be explicitly converted to an lvalue of
5353 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5354 types) if a pointer to T1 can be explicitly converted to the type
5355 pointer to T2 using a const_cast. */
5356 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5358 reference_type = dst_type;
5359 if (! real_lvalue_p (expr))
5362 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5363 src_type, dst_type);
5364 return error_mark_node;
5366 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5367 src_type = build_pointer_type (src_type);
5371 reference_type = NULL_TREE;
5372 /* If the destination type is not a reference type, the
5373 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5374 conversions are performed. */
5375 src_type = type_decays_to (src_type);
5376 if (src_type == error_mark_node)
5377 return error_mark_node;
5380 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5381 && comp_ptr_ttypes_const (dst_type, src_type))
5386 /* This cast is actually a C-style cast. Issue a warning if
5387 the user is making a potentially unsafe cast. */
5389 check_for_casting_away_constness (src_type, dst_type,
5395 expr = build_unary_op (ADDR_EXPR, expr, 0);
5396 expr = build_nop (reference_type, expr);
5397 return convert_from_reference (expr);
5401 expr = decay_conversion (expr);
5402 /* build_c_cast puts on a NOP_EXPR to make the result not an
5403 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5404 non-lvalue context. */
5405 if (TREE_CODE (expr) == NOP_EXPR
5406 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5407 expr = TREE_OPERAND (expr, 0);
5408 return build_nop (dst_type, expr);
5413 error ("invalid const_cast from type %qT to type %qT",
5414 src_type, dst_type);
5415 return error_mark_node;
5419 build_const_cast (tree type, tree expr)
5421 if (type == error_mark_node || error_operand_p (expr))
5422 return error_mark_node;
5424 if (processing_template_decl)
5426 tree t = build_min (CONST_CAST_EXPR, type, expr);
5428 if (!TREE_SIDE_EFFECTS (t)
5429 && type_dependent_expression_p (expr))
5430 /* There might turn out to be side effects inside expr. */
5431 TREE_SIDE_EFFECTS (t) = 1;
5432 return convert_from_reference (t);
5435 return build_const_cast_1 (type, expr, /*complain=*/true,
5439 /* Build an expression representing an explicit C-style cast to type
5440 TYPE of expression EXPR. */
5443 build_c_cast (tree type, tree expr)
5449 if (type == error_mark_node || error_operand_p (expr))
5450 return error_mark_node;
5452 if (processing_template_decl)
5454 tree t = build_min (CAST_EXPR, type,
5455 tree_cons (NULL_TREE, value, NULL_TREE));
5456 /* We don't know if it will or will not have side effects. */
5457 TREE_SIDE_EFFECTS (t) = 1;
5458 return convert_from_reference (t);
5461 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5462 'Class') should always be retained, because this information aids
5463 in method lookup. */
5464 if (objc_is_object_ptr (type)
5465 && objc_is_object_ptr (TREE_TYPE (expr)))
5466 return build_nop (type, expr);
5468 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5469 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5470 if (TREE_CODE (type) != REFERENCE_TYPE
5471 && TREE_CODE (value) == NOP_EXPR
5472 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5473 value = TREE_OPERAND (value, 0);
5475 if (TREE_CODE (type) == ARRAY_TYPE)
5477 /* Allow casting from T1* to T2[] because Cfront allows it.
5478 NIHCL uses it. It is not valid ISO C++ however. */
5479 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5481 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5482 type = build_pointer_type (TREE_TYPE (type));
5486 error ("ISO C++ forbids casting to an array type %qT", type);
5487 return error_mark_node;
5491 if (TREE_CODE (type) == FUNCTION_TYPE
5492 || TREE_CODE (type) == METHOD_TYPE)
5494 error ("invalid cast to function type %qT", type);
5495 return error_mark_node;
5498 /* A C-style cast can be a const_cast. */
5499 result = build_const_cast_1 (type, value, /*complain=*/false,
5504 /* Or a static cast. */
5505 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5507 /* Or a reinterpret_cast. */
5509 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5511 /* The static_cast or reinterpret_cast may be followed by a
5514 /* A valid cast may result in errors if, for example, a
5515 conversion to am ambiguous base class is required. */
5516 && !error_operand_p (result))
5520 /* Non-class rvalues always have cv-unqualified type. */
5521 if (!CLASS_TYPE_P (type))
5522 type = TYPE_MAIN_VARIANT (type);
5523 result_type = TREE_TYPE (result);
5524 if (!CLASS_TYPE_P (result_type))
5525 result_type = TYPE_MAIN_VARIANT (result_type);
5526 /* If the type of RESULT does not match TYPE, perform a
5527 const_cast to make it match. If the static_cast or
5528 reinterpret_cast succeeded, we will differ by at most
5529 cv-qualification, so the follow-on const_cast is guaranteed
5531 if (!same_type_p (non_reference (type), non_reference (result_type)))
5533 result = build_const_cast_1 (type, result, false, &valid_p);
5534 gcc_assert (valid_p);
5539 return error_mark_node;
5542 /* Build an assignment expression of lvalue LHS from value RHS.
5543 MODIFYCODE is the code for a binary operator that we use
5544 to combine the old value of LHS with RHS to get the new value.
5545 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5547 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5550 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5554 tree lhstype = TREE_TYPE (lhs);
5555 tree olhstype = lhstype;
5556 tree olhs = NULL_TREE;
5557 bool plain_assign = (modifycode == NOP_EXPR);
5559 /* Avoid duplicate error messages from operands that had errors. */
5560 if (error_operand_p (lhs) || error_operand_p (rhs))
5561 return error_mark_node;
5563 /* Handle control structure constructs used as "lvalues". */
5564 switch (TREE_CODE (lhs))
5566 /* Handle --foo = 5; as these are valid constructs in C++. */
5567 case PREDECREMENT_EXPR:
5568 case PREINCREMENT_EXPR:
5569 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5570 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5571 stabilize_reference (TREE_OPERAND (lhs, 0)),
5572 TREE_OPERAND (lhs, 1));
5573 return build2 (COMPOUND_EXPR, lhstype,
5575 build_modify_expr (TREE_OPERAND (lhs, 0),
5578 /* Handle (a, b) used as an "lvalue". */
5580 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5582 if (newrhs == error_mark_node)
5583 return error_mark_node;
5584 return build2 (COMPOUND_EXPR, lhstype,
5585 TREE_OPERAND (lhs, 0), newrhs);
5588 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5589 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5590 stabilize_reference (TREE_OPERAND (lhs, 0)),
5591 TREE_OPERAND (lhs, 1));
5592 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5593 if (newrhs == error_mark_node)
5594 return error_mark_node;
5595 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5599 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5600 when neither operand has side-effects. */
5601 if (!lvalue_or_else (lhs, lv_assign))
5602 return error_mark_node;
5604 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5605 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5607 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5608 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5610 TREE_OPERAND (lhs, 0),
5611 TREE_OPERAND (lhs, 1)),
5612 TREE_OPERAND (lhs, 0),
5613 TREE_OPERAND (lhs, 1));
5616 /* Handle (a ? b : c) used as an "lvalue". */
5619 /* Produce (a ? (b = rhs) : (c = rhs))
5620 except that the RHS goes through a save-expr
5621 so the code to compute it is only emitted once. */
5623 tree preeval = NULL_TREE;
5625 rhs = stabilize_expr (rhs, &preeval);
5627 /* Check this here to avoid odd errors when trying to convert
5628 a throw to the type of the COND_EXPR. */
5629 if (!lvalue_or_else (lhs, lv_assign))
5630 return error_mark_node;
5632 cond = build_conditional_expr
5633 (TREE_OPERAND (lhs, 0),
5634 build_modify_expr (TREE_OPERAND (lhs, 1),
5636 build_modify_expr (TREE_OPERAND (lhs, 2),
5639 if (cond == error_mark_node)
5641 /* Make sure the code to compute the rhs comes out
5642 before the split. */
5644 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5652 if (modifycode == INIT_EXPR)
5654 if (TREE_CODE (rhs) == CONSTRUCTOR)
5656 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5657 /* Call convert to generate an error; see PR 11063. */
5658 rhs = convert (lhstype, rhs);
5659 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5660 TREE_SIDE_EFFECTS (result) = 1;
5663 else if (! IS_AGGR_TYPE (lhstype))
5664 /* Do the default thing. */;
5667 result = build_special_member_call (lhs, complete_ctor_identifier,
5668 build_tree_list (NULL_TREE, rhs),
5669 lhstype, LOOKUP_NORMAL);
5670 if (result == NULL_TREE)
5671 return error_mark_node;
5677 lhs = require_complete_type (lhs);
5678 if (lhs == error_mark_node)
5679 return error_mark_node;
5681 if (modifycode == NOP_EXPR)
5683 /* `operator=' is not an inheritable operator. */
5684 if (! IS_AGGR_TYPE (lhstype))
5685 /* Do the default thing. */;
5688 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5689 lhs, rhs, make_node (NOP_EXPR),
5690 /*overloaded_p=*/NULL);
5691 if (result == NULL_TREE)
5692 return error_mark_node;
5699 /* A binary op has been requested. Combine the old LHS
5700 value with the RHS producing the value we should actually
5701 store into the LHS. */
5703 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5704 lhs = stabilize_reference (lhs);
5705 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5706 if (newrhs == error_mark_node)
5708 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5709 TREE_TYPE (lhs), TREE_TYPE (rhs));
5710 return error_mark_node;
5713 /* Now it looks like a plain assignment. */
5714 modifycode = NOP_EXPR;
5716 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5717 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5720 /* The left-hand side must be an lvalue. */
5721 if (!lvalue_or_else (lhs, lv_assign))
5722 return error_mark_node;
5724 /* Warn about modifying something that is `const'. Don't warn if
5725 this is initialization. */
5726 if (modifycode != INIT_EXPR
5727 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5728 /* Functions are not modifiable, even though they are
5730 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5731 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5732 /* If it's an aggregate and any field is const, then it is
5733 effectively const. */
5734 || (CLASS_TYPE_P (lhstype)
5735 && C_TYPE_FIELDS_READONLY (lhstype))))
5736 readonly_error (lhs, "assignment", 0);
5738 /* If storing into a structure or union member, it has probably been
5739 given type `int'. Compute the type that would go with the actual
5740 amount of storage the member occupies. */
5742 if (TREE_CODE (lhs) == COMPONENT_REF
5743 && (TREE_CODE (lhstype) == INTEGER_TYPE
5744 || TREE_CODE (lhstype) == REAL_TYPE
5745 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5747 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5749 /* If storing in a field that is in actuality a short or narrower
5750 than one, we must store in the field in its actual type. */
5752 if (lhstype != TREE_TYPE (lhs))
5754 /* Avoid warnings converting integral types back into enums for
5756 if (TREE_CODE (lhstype) == INTEGER_TYPE
5757 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5759 if (TREE_SIDE_EFFECTS (lhs))
5760 lhs = stabilize_reference (lhs);
5763 lhs = copy_node (lhs);
5764 TREE_TYPE (lhs) = lhstype;
5768 /* Convert new value to destination type. */
5770 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5774 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5775 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5777 error ("incompatible types in assignment of %qT to %qT",
5778 TREE_TYPE (rhs), lhstype);
5779 return error_mark_node;
5782 /* Allow array assignment in compiler-generated code. */
5783 if (! DECL_ARTIFICIAL (current_function_decl))
5785 /* This routine is used for both initialization and assignment.
5786 Make sure the diagnostic message differentiates the context. */
5787 if (modifycode == INIT_EXPR)
5788 error ("array used as initializer");
5790 error ("invalid array assignment");
5791 return error_mark_node;
5794 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5795 ? 1 + (modifycode != INIT_EXPR): 0;
5796 return build_vec_init (lhs, NULL_TREE, newrhs,
5797 /*explicit_default_init_p=*/false,
5801 if (modifycode == INIT_EXPR)
5802 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5803 "initialization", NULL_TREE, 0);
5806 /* Avoid warnings on enum bit fields. */
5807 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5808 && TREE_CODE (lhstype) == INTEGER_TYPE)
5810 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5812 newrhs = convert_force (lhstype, newrhs, 0);
5815 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5817 if (TREE_CODE (newrhs) == CALL_EXPR
5818 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5819 newrhs = build_cplus_new (lhstype, newrhs);
5821 /* Can't initialize directly from a TARGET_EXPR, since that would
5822 cause the lhs to be constructed twice, and possibly result in
5823 accidental self-initialization. So we force the TARGET_EXPR to be
5824 expanded without a target. */
5825 if (TREE_CODE (newrhs) == TARGET_EXPR)
5826 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5827 TREE_OPERAND (newrhs, 0));
5830 if (newrhs == error_mark_node)
5831 return error_mark_node;
5833 if (c_dialect_objc () && flag_objc_gc)
5835 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5841 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5842 lhstype, lhs, newrhs);
5844 TREE_SIDE_EFFECTS (result) = 1;
5846 TREE_NO_WARNING (result) = 1;
5848 /* If we got the LHS in a different type for storing in,
5849 convert the result back to the nominal type of LHS
5850 so that the value we return always has the same type
5851 as the LHS argument. */
5853 if (olhstype == TREE_TYPE (result))
5857 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5858 TREE_NO_WARNING (result) = 1;
5861 return convert_for_assignment (olhstype, result, "assignment",
5866 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5868 if (processing_template_decl)
5869 return build_min_nt (MODOP_EXPR, lhs,
5870 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5872 if (modifycode != NOP_EXPR)
5874 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5875 make_node (modifycode),
5876 /*overloaded_p=*/NULL);
5879 TREE_NO_WARNING (rval) = 1;
5883 return build_modify_expr (lhs, modifycode, rhs);
5887 /* Get difference in deltas for different pointer to member function
5888 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5889 the conversion is invalid, the constant is zero. If
5890 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5891 If C_CAST_P is true this conversion is taking place as part of a
5894 Note that the naming of FROM and TO is kind of backwards; the return
5895 value is what we add to a TO in order to get a FROM. They are named
5896 this way because we call this function to find out how to convert from
5897 a pointer to member of FROM to a pointer to member of TO. */
5900 get_delta_difference (tree from, tree to,
5901 bool allow_inverse_p,
5908 /* Assume no conversion is required. */
5909 result = integer_zero_node;
5910 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5911 if (kind == bk_inaccessible || kind == bk_ambig)
5912 error (" in pointer to member function conversion");
5915 if (kind != bk_via_virtual)
5916 result = BINFO_OFFSET (binfo);
5919 tree virt_binfo = binfo_from_vbase (binfo);
5921 /* This is a reinterpret cast, we choose to do nothing. */
5922 if (allow_inverse_p)
5923 warning (0, "pointer to member cast via virtual base %qT",
5924 BINFO_TYPE (virt_binfo));
5926 error ("pointer to member conversion via virtual base %qT",
5927 BINFO_TYPE (virt_binfo));
5930 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5931 /* Pointer to member of incomplete class is permitted*/;
5932 else if (!allow_inverse_p)
5934 error_not_base_type (from, to);
5935 error (" in pointer to member conversion");
5939 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5942 if (kind != bk_via_virtual)
5943 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5946 /* This is a reinterpret cast, we choose to do nothing. */
5947 tree virt_binfo = binfo_from_vbase (binfo);
5949 warning (0, "pointer to member cast via virtual base %qT",
5950 BINFO_TYPE (virt_binfo));
5955 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5959 /* Return a constructor for the pointer-to-member-function TYPE using
5960 the other components as specified. */
5963 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
5968 VEC(constructor_elt, gc) *v;
5970 /* Pull the FIELD_DECLs out of the type. */
5971 pfn_field = TYPE_FIELDS (type);
5972 delta_field = TREE_CHAIN (pfn_field);
5974 /* Make sure DELTA has the type we want. */
5975 delta = convert_and_check (delta_type_node, delta);
5977 /* Finish creating the initializer. */
5978 v = VEC_alloc(constructor_elt, gc, 2);
5979 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
5980 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
5981 u = build_constructor (type, v);
5982 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
5983 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
5984 TREE_STATIC (u) = (TREE_CONSTANT (u)
5985 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
5987 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
5992 /* Build a constructor for a pointer to member function. It can be
5993 used to initialize global variables, local variable, or used
5994 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
5997 If FORCE is nonzero, then force this conversion, even if
5998 we would rather not do it. Usually set when using an explicit
5999 cast. A C-style cast is being processed iff C_CAST_P is true.
6001 Return error_mark_node, if something goes wrong. */
6004 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6010 if (error_operand_p (pfn))
6011 return error_mark_node;
6013 pfn_type = TREE_TYPE (pfn);
6014 to_type = build_ptrmemfunc_type (type);
6016 /* Handle multiple conversions of pointer to member functions. */
6017 if (TYPE_PTRMEMFUNC_P (pfn_type))
6019 tree delta = NULL_TREE;
6020 tree npfn = NULL_TREE;
6024 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6025 error ("invalid conversion to type %qT from type %qT",
6028 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6029 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6033 /* We don't have to do any conversion to convert a
6034 pointer-to-member to its own type. But, we don't want to
6035 just return a PTRMEM_CST if there's an explicit cast; that
6036 cast should make the expression an invalid template argument. */
6037 if (TREE_CODE (pfn) != PTRMEM_CST)
6039 if (same_type_p (to_type, pfn_type))
6041 else if (integer_zerop (n))
6042 return build_reinterpret_cast (to_type, pfn);
6045 if (TREE_SIDE_EFFECTS (pfn))
6046 pfn = save_expr (pfn);
6048 /* Obtain the function pointer and the current DELTA. */
6049 if (TREE_CODE (pfn) == PTRMEM_CST)
6050 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6053 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6054 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6057 /* Just adjust the DELTA field. */
6058 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6059 (TREE_TYPE (delta), ptrdiff_type_node));
6060 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6061 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6062 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6063 return build_ptrmemfunc1 (to_type, delta, npfn);
6066 /* Handle null pointer to member function conversions. */
6067 if (integer_zerop (pfn))
6069 pfn = build_c_cast (type, integer_zero_node);
6070 return build_ptrmemfunc1 (to_type,
6075 if (type_unknown_p (pfn))
6076 return instantiate_type (type, pfn, tf_warning_or_error);
6078 fn = TREE_OPERAND (pfn, 0);
6079 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6080 /* In a template, we will have preserved the
6082 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6083 return make_ptrmem_cst (to_type, fn);
6086 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6089 ??? There is no consistency as to the types returned for the above
6090 values. Some code acts as if it were a sizetype and some as if it were
6091 integer_type_node. */
6094 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6096 tree type = TREE_TYPE (cst);
6097 tree fn = PTRMEM_CST_MEMBER (cst);
6098 tree ptr_class, fn_class;
6100 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6102 /* The class that the function belongs to. */
6103 fn_class = DECL_CONTEXT (fn);
6105 /* The class that we're creating a pointer to member of. */
6106 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6108 /* First, calculate the adjustment to the function's class. */
6109 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6112 if (!DECL_VIRTUAL_P (fn))
6113 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6116 /* If we're dealing with a virtual function, we have to adjust 'this'
6117 again, to point to the base which provides the vtable entry for
6118 fn; the call will do the opposite adjustment. */
6119 tree orig_class = DECL_CONTEXT (fn);
6120 tree binfo = binfo_or_else (orig_class, fn_class);
6121 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6122 *delta, BINFO_OFFSET (binfo));
6123 *delta = fold_if_not_in_template (*delta);
6125 /* We set PFN to the vtable offset at which the function can be
6126 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6127 case delta is shifted left, and then incremented). */
6128 *pfn = DECL_VINDEX (fn);
6129 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6130 TYPE_SIZE_UNIT (vtable_entry_type));
6131 *pfn = fold_if_not_in_template (*pfn);
6133 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6135 case ptrmemfunc_vbit_in_pfn:
6136 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6138 *pfn = fold_if_not_in_template (*pfn);
6141 case ptrmemfunc_vbit_in_delta:
6142 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6143 *delta, integer_one_node);
6144 *delta = fold_if_not_in_template (*delta);
6145 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6146 *delta, integer_one_node);
6147 *delta = fold_if_not_in_template (*delta);
6154 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6155 *pfn = fold_if_not_in_template (*pfn);
6159 /* Return an expression for PFN from the pointer-to-member function
6163 pfn_from_ptrmemfunc (tree t)
6165 if (TREE_CODE (t) == PTRMEM_CST)
6170 expand_ptrmemfunc_cst (t, &delta, &pfn);
6175 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6178 /* Convert value RHS to type TYPE as preparation for an assignment to
6179 an lvalue of type TYPE. ERRTYPE is a string to use in error
6180 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6181 are doing the conversion in order to pass the PARMNUMth argument of
6185 convert_for_assignment (tree type, tree rhs,
6186 const char *errtype, tree fndecl, int parmnum)
6189 enum tree_code coder;
6191 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6192 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6193 rhs = TREE_OPERAND (rhs, 0);
6195 rhstype = TREE_TYPE (rhs);
6196 coder = TREE_CODE (rhstype);
6198 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6199 && vector_types_convertible_p (type, rhstype))
6200 return convert (type, rhs);
6202 if (rhs == error_mark_node || rhstype == error_mark_node)
6203 return error_mark_node;
6204 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6205 return error_mark_node;
6207 /* The RHS of an assignment cannot have void type. */
6208 if (coder == VOID_TYPE)
6210 error ("void value not ignored as it ought to be");
6211 return error_mark_node;
6214 /* Simplify the RHS if possible. */
6215 if (TREE_CODE (rhs) == CONST_DECL)
6216 rhs = DECL_INITIAL (rhs);
6218 if (c_dialect_objc ())
6221 tree rname = fndecl;
6223 if (!strcmp (errtype, "assignment"))
6225 else if (!strcmp (errtype, "initialization"))
6229 tree selector = objc_message_selector ();
6233 if (selector && parmno > 1)
6240 if (objc_compare_types (type, rhstype, parmno, rname))
6241 return convert (type, rhs);
6246 The expression is implicitly converted (clause _conv_) to the
6247 cv-unqualified type of the left operand.
6249 We allow bad conversions here because by the time we get to this point
6250 we are committed to doing the conversion. If we end up doing a bad
6251 conversion, convert_like will complain. */
6252 if (!can_convert_arg_bad (type, rhstype, rhs))
6254 /* When -Wno-pmf-conversions is use, we just silently allow
6255 conversions from pointers-to-members to plain pointers. If
6256 the conversion doesn't work, cp_convert will complain. */
6258 && TYPE_PTR_P (type)
6259 && TYPE_PTRMEMFUNC_P (rhstype))
6260 rhs = cp_convert (strip_top_quals (type), rhs);
6263 /* If the right-hand side has unknown type, then it is an
6264 overloaded function. Call instantiate_type to get error
6266 if (rhstype == unknown_type_node)
6267 instantiate_type (type, rhs, tf_warning_or_error);
6269 error ("cannot convert %qT to %qT for argument %qP to %qD",
6270 rhstype, type, parmnum, fndecl);
6272 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6273 return error_mark_node;
6276 if (warn_missing_format_attribute)
6278 const enum tree_code codel = TREE_CODE (type);
6279 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6281 && check_missing_format_attribute (type, rhstype))
6282 warning (OPT_Wmissing_format_attribute,
6283 "%s might be a candidate for a format attribute",
6287 return perform_implicit_conversion (strip_top_quals (type), rhs);
6290 /* Convert RHS to be of type TYPE.
6291 If EXP is nonzero, it is the target of the initialization.
6292 ERRTYPE is a string to use in error messages.
6294 Two major differences between the behavior of
6295 `convert_for_assignment' and `convert_for_initialization'
6296 are that references are bashed in the former, while
6297 copied in the latter, and aggregates are assigned in
6298 the former (operator=) while initialized in the
6301 If using constructor make sure no conversion operator exists, if one does
6302 exist, an ambiguity exists.
6304 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6307 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6308 const char *errtype, tree fndecl, int parmnum)
6310 enum tree_code codel = TREE_CODE (type);
6312 enum tree_code coder;
6314 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6315 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6316 if (TREE_CODE (rhs) == NOP_EXPR
6317 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6318 && codel != REFERENCE_TYPE)
6319 rhs = TREE_OPERAND (rhs, 0);
6321 if (type == error_mark_node
6322 || rhs == error_mark_node
6323 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6324 return error_mark_node;
6326 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6327 && TREE_CODE (type) != ARRAY_TYPE
6328 && (TREE_CODE (type) != REFERENCE_TYPE
6329 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6330 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6331 && (TREE_CODE (type) != REFERENCE_TYPE
6332 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6333 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6334 rhs = decay_conversion (rhs);
6336 rhstype = TREE_TYPE (rhs);
6337 coder = TREE_CODE (rhstype);
6339 if (coder == ERROR_MARK)
6340 return error_mark_node;
6342 /* We accept references to incomplete types, so we can
6343 return here before checking if RHS is of complete type. */
6345 if (codel == REFERENCE_TYPE)
6347 /* This should eventually happen in convert_arguments. */
6348 int savew = 0, savee = 0;
6351 savew = warningcount, savee = errorcount;
6352 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6356 if (warningcount > savew)
6357 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6358 else if (errorcount > savee)
6359 error ("in passing argument %P of %q+D", parmnum, fndecl);
6365 exp = require_complete_type (exp);
6366 if (exp == error_mark_node)
6367 return error_mark_node;
6369 rhstype = non_reference (rhstype);
6371 type = complete_type (type);
6373 if (IS_AGGR_TYPE (type))
6374 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6376 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6379 /* If RETVAL is the address of, or a reference to, a local variable or
6380 temporary give an appropriate warning. */
6383 maybe_warn_about_returning_address_of_local (tree retval)
6385 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6386 tree whats_returned = retval;
6390 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6391 whats_returned = TREE_OPERAND (whats_returned, 1);
6392 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6393 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6394 || TREE_CODE (whats_returned) == NOP_EXPR)
6395 whats_returned = TREE_OPERAND (whats_returned, 0);
6400 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6402 whats_returned = TREE_OPERAND (whats_returned, 0);
6404 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6406 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6407 || TREE_CODE (whats_returned) == TARGET_EXPR)
6409 warning (0, "returning reference to temporary");
6412 if (TREE_CODE (whats_returned) == VAR_DECL
6413 && DECL_NAME (whats_returned)
6414 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6416 warning (0, "reference to non-lvalue returned");
6421 while (TREE_CODE (whats_returned) == COMPONENT_REF
6422 || TREE_CODE (whats_returned) == ARRAY_REF)
6423 whats_returned = TREE_OPERAND (whats_returned, 0);
6425 if (DECL_P (whats_returned)
6426 && DECL_NAME (whats_returned)
6427 && DECL_FUNCTION_SCOPE_P (whats_returned)
6428 && !(TREE_STATIC (whats_returned)
6429 || TREE_PUBLIC (whats_returned)))
6431 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6432 warning (0, "reference to local variable %q+D returned",
6435 warning (0, "address of local variable %q+D returned",
6441 /* Check that returning RETVAL from the current function is valid.
6442 Return an expression explicitly showing all conversions required to
6443 change RETVAL into the function return type, and to assign it to
6444 the DECL_RESULT for the function. Set *NO_WARNING to true if
6445 code reaches end of non-void function warning shouldn't be issued
6446 on this RETURN_EXPR. */
6449 check_return_expr (tree retval, bool *no_warning)
6452 /* The type actually returned by the function, after any
6455 int fn_returns_value_p;
6457 *no_warning = false;
6459 /* A `volatile' function is one that isn't supposed to return, ever.
6460 (This is a G++ extension, used to get better code for functions
6461 that call the `volatile' function.) */
6462 if (TREE_THIS_VOLATILE (current_function_decl))
6463 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6465 /* Check for various simple errors. */
6466 if (DECL_DESTRUCTOR_P (current_function_decl))
6469 error ("returning a value from a destructor");
6472 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6474 if (in_function_try_handler)
6475 /* If a return statement appears in a handler of the
6476 function-try-block of a constructor, the program is ill-formed. */
6477 error ("cannot return from a handler of a function-try-block of a constructor");
6479 /* You can't return a value from a constructor. */
6480 error ("returning a value from a constructor");
6484 if (processing_template_decl)
6486 current_function_returns_value = 1;
6490 /* When no explicit return-value is given in a function with a named
6491 return value, the named return value is used. */
6492 result = DECL_RESULT (current_function_decl);
6493 valtype = TREE_TYPE (result);
6494 gcc_assert (valtype != NULL_TREE);
6495 fn_returns_value_p = !VOID_TYPE_P (valtype);
6496 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6499 /* Check for a return statement with no return value in a function
6500 that's supposed to return a value. */
6501 if (!retval && fn_returns_value_p)
6503 pedwarn ("return-statement with no value, in function returning %qT",
6505 /* Clear this, so finish_function won't say that we reach the
6506 end of a non-void function (which we don't, we gave a
6508 current_function_returns_null = 0;
6509 /* And signal caller that TREE_NO_WARNING should be set on the
6510 RETURN_EXPR to avoid control reaches end of non-void function
6511 warnings in tree-cfg.c. */
6514 /* Check for a return statement with a value in a function that
6515 isn't supposed to return a value. */
6516 else if (retval && !fn_returns_value_p)
6518 if (VOID_TYPE_P (TREE_TYPE (retval)))
6519 /* You can return a `void' value from a function of `void'
6520 type. In that case, we have to evaluate the expression for
6521 its side-effects. */
6522 finish_expr_stmt (retval);
6524 pedwarn ("return-statement with a value, in function "
6525 "returning 'void'");
6527 current_function_returns_null = 1;
6529 /* There's really no value to return, after all. */
6533 /* Remember that this function can sometimes return without a
6535 current_function_returns_null = 1;
6537 /* Remember that this function did return a value. */
6538 current_function_returns_value = 1;
6540 /* Check for erroneous operands -- but after giving ourselves a
6541 chance to provide an error about returning a value from a void
6543 if (error_operand_p (retval))
6545 current_function_return_value = error_mark_node;
6546 return error_mark_node;
6549 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6550 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6551 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6552 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6554 && null_ptr_cst_p (retval))
6555 warning (0, "%<operator new%> must not return NULL unless it is "
6556 "declared %<throw()%> (or -fcheck-new is in effect)");
6558 /* Effective C++ rule 15. See also start_function. */
6560 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6564 /* The function return type must be a reference to the current
6566 if (TREE_CODE (valtype) == REFERENCE_TYPE
6567 && same_type_ignoring_top_level_qualifiers_p
6568 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6570 /* Returning '*this' is obviously OK. */
6571 if (retval == current_class_ref)
6573 /* If we are calling a function whose return type is the same of
6574 the current class reference, it is ok. */
6575 else if (TREE_CODE (retval) == INDIRECT_REF
6576 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6581 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6584 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6586 [...] For a function with a class return type, if the expression
6587 in the return statement is the name of a local object, and the cv-
6588 unqualified type of the local object is the same as the function
6589 return type, an implementation is permitted to omit creating the tem-
6590 porary object to hold the function return value [...]
6592 So, if this is a value-returning function that always returns the same
6593 local variable, remember it.
6595 It might be nice to be more flexible, and choose the first suitable
6596 variable even if the function sometimes returns something else, but
6597 then we run the risk of clobbering the variable we chose if the other
6598 returned expression uses the chosen variable somehow. And people expect
6599 this restriction, anyway. (jason 2000-11-19)
6601 See finish_function and finalize_nrv for the rest of this optimization. */
6603 if (fn_returns_value_p && flag_elide_constructors)
6605 if (retval != NULL_TREE
6606 && (current_function_return_value == NULL_TREE
6607 || current_function_return_value == retval)
6608 && TREE_CODE (retval) == VAR_DECL
6609 && DECL_CONTEXT (retval) == current_function_decl
6610 && ! TREE_STATIC (retval)
6611 && (DECL_ALIGN (retval)
6612 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6613 && same_type_p ((TYPE_MAIN_VARIANT
6614 (TREE_TYPE (retval))),
6616 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6617 current_function_return_value = retval;
6619 current_function_return_value = error_mark_node;
6622 /* We don't need to do any conversions when there's nothing being
6627 /* Do any required conversions. */
6628 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6629 /* No conversions are required. */
6633 /* The type the function is declared to return. */
6634 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6636 /* The functype's return type will have been set to void, if it
6637 was an incomplete type. Just treat this as 'return;' */
6638 if (VOID_TYPE_P (functype))
6639 return error_mark_node;
6641 /* First convert the value to the function's return type, then
6642 to the type of return value's location to handle the
6643 case that functype is smaller than the valtype. */
6644 retval = convert_for_initialization
6645 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6646 "return", NULL_TREE, 0);
6647 retval = convert (valtype, retval);
6649 /* If the conversion failed, treat this just like `return;'. */
6650 if (retval == error_mark_node)
6652 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6653 else if (! current_function_returns_struct
6654 && TREE_CODE (retval) == TARGET_EXPR
6655 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6656 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6657 TREE_OPERAND (retval, 0));
6659 maybe_warn_about_returning_address_of_local (retval);
6662 /* Actually copy the value returned into the appropriate location. */
6663 if (retval && retval != result)
6664 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6670 /* Returns nonzero if the pointer-type FROM can be converted to the
6671 pointer-type TO via a qualification conversion. If CONSTP is -1,
6672 then we return nonzero if the pointers are similar, and the
6673 cv-qualification signature of FROM is a proper subset of that of TO.
6675 If CONSTP is positive, then all outer pointers have been
6679 comp_ptr_ttypes_real (tree to, tree from, int constp)
6681 bool to_more_cv_qualified = false;
6683 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6685 if (TREE_CODE (to) != TREE_CODE (from))
6688 if (TREE_CODE (from) == OFFSET_TYPE
6689 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6690 TYPE_OFFSET_BASETYPE (to)))
6693 /* Const and volatile mean something different for function types,
6694 so the usual checks are not appropriate. */
6695 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6697 /* In Objective-C++, some types may have been 'volatilized' by
6698 the compiler for EH; when comparing them here, the volatile
6699 qualification must be ignored. */
6700 bool objc_quals_match = objc_type_quals_match (to, from);
6702 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6705 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6709 to_more_cv_qualified = true;
6713 constp &= TYPE_READONLY (to);
6716 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6717 return ((constp >= 0 || to_more_cv_qualified)
6718 && same_type_ignoring_top_level_qualifiers_p (to, from));
6722 /* When comparing, say, char ** to char const **, this function takes
6723 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6724 types to this function. */
6727 comp_ptr_ttypes (tree to, tree from)
6729 return comp_ptr_ttypes_real (to, from, 1);
6732 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6733 type or inheritance-related types, regardless of cv-quals. */
6736 ptr_reasonably_similar (tree to, tree from)
6738 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6740 /* Any target type is similar enough to void. */
6741 if (TREE_CODE (to) == VOID_TYPE
6742 || TREE_CODE (from) == VOID_TYPE)
6745 if (TREE_CODE (to) != TREE_CODE (from))
6748 if (TREE_CODE (from) == OFFSET_TYPE
6749 && comptypes (TYPE_OFFSET_BASETYPE (to),
6750 TYPE_OFFSET_BASETYPE (from),
6751 COMPARE_BASE | COMPARE_DERIVED))
6754 if (TREE_CODE (to) == VECTOR_TYPE
6755 && vector_types_convertible_p (to, from))
6758 if (TREE_CODE (to) == INTEGER_TYPE
6759 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6762 if (TREE_CODE (to) == FUNCTION_TYPE)
6765 if (TREE_CODE (to) != POINTER_TYPE)
6767 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6768 COMPARE_BASE | COMPARE_DERIVED);
6772 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6773 pointer-to-member types) are the same, ignoring cv-qualification at
6777 comp_ptr_ttypes_const (tree to, tree from)
6779 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6781 if (TREE_CODE (to) != TREE_CODE (from))
6784 if (TREE_CODE (from) == OFFSET_TYPE
6785 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6786 TYPE_OFFSET_BASETYPE (to)))
6789 if (TREE_CODE (to) != POINTER_TYPE)
6790 return same_type_ignoring_top_level_qualifiers_p (to, from);
6794 /* Returns the type qualifiers for this type, including the qualifiers on the
6795 elements for an array type. */
6798 cp_type_quals (tree type)
6800 type = strip_array_types (type);
6801 if (type == error_mark_node)
6802 return TYPE_UNQUALIFIED;
6803 return TYPE_QUALS (type);
6806 /* Returns nonzero if the TYPE contains a mutable member. */
6809 cp_has_mutable_p (tree type)
6811 type = strip_array_types (type);
6813 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6816 /* Apply the TYPE_QUALS to the new DECL. */
6818 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6820 tree type = TREE_TYPE (decl);
6822 if (type == error_mark_node)
6825 if (TREE_CODE (type) == FUNCTION_TYPE
6826 && type_quals != TYPE_UNQUALIFIED)
6828 /* This was an error in C++98 (cv-qualifiers cannot be added to
6829 a function type), but DR 295 makes the code well-formed by
6830 dropping the extra qualifiers. */
6833 tree bad_type = build_qualified_type (type, type_quals);
6834 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6838 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6842 /* Avoid setting TREE_READONLY incorrectly. */
6843 if (/* If the object has a constructor, the constructor may modify
6845 TYPE_NEEDS_CONSTRUCTING (type)
6846 /* If the type isn't complete, we don't know yet if it will need
6848 || !COMPLETE_TYPE_P (type)
6849 /* If the type has a mutable component, that component might be
6851 || TYPE_HAS_MUTABLE_P (type))
6852 type_quals &= ~TYPE_QUAL_CONST;
6854 c_apply_type_quals_to_decl (type_quals, decl);
6857 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6858 exemplar types such that casting T1 to T2 is casting away constness
6859 if and only if there is no implicit conversion from T1 to T2. */
6862 casts_away_constness_r (tree *t1, tree *t2)
6867 /* [expr.const.cast]
6869 For multi-level pointer to members and multi-level mixed pointers
6870 and pointers to members (conv.qual), the "member" aspect of a
6871 pointer to member level is ignored when determining if a const
6872 cv-qualifier has been cast away. */
6873 /* [expr.const.cast]
6875 For two pointer types:
6877 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6878 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6881 casting from X1 to X2 casts away constness if, for a non-pointer
6882 type T there does not exist an implicit conversion (clause
6885 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6889 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6890 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6891 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6893 *t1 = cp_build_qualified_type (void_type_node,
6894 cp_type_quals (*t1));
6895 *t2 = cp_build_qualified_type (void_type_node,
6896 cp_type_quals (*t2));
6900 quals1 = cp_type_quals (*t1);
6901 quals2 = cp_type_quals (*t2);
6903 if (TYPE_PTRMEM_P (*t1))
6904 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6906 *t1 = TREE_TYPE (*t1);
6907 if (TYPE_PTRMEM_P (*t2))
6908 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6910 *t2 = TREE_TYPE (*t2);
6912 casts_away_constness_r (t1, t2);
6913 *t1 = build_pointer_type (*t1);
6914 *t2 = build_pointer_type (*t2);
6915 *t1 = cp_build_qualified_type (*t1, quals1);
6916 *t2 = cp_build_qualified_type (*t2, quals2);
6919 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6923 casts_away_constness (tree t1, tree t2)
6925 if (TREE_CODE (t2) == REFERENCE_TYPE)
6927 /* [expr.const.cast]
6929 Casting from an lvalue of type T1 to an lvalue of type T2
6930 using a reference cast casts away constness if a cast from an
6931 rvalue of type "pointer to T1" to the type "pointer to T2"
6932 casts away constness. */
6933 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6934 return casts_away_constness (build_pointer_type (t1),
6935 build_pointer_type (TREE_TYPE (t2)));
6938 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6939 /* [expr.const.cast]
6941 Casting from an rvalue of type "pointer to data member of X
6942 of type T1" to the type "pointer to data member of Y of type
6943 T2" casts away constness if a cast from an rvalue of type
6944 "pointer to T1" to the type "pointer to T2" casts away
6946 return casts_away_constness
6947 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
6948 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
6950 /* Casting away constness is only something that makes sense for
6951 pointer or reference types. */
6952 if (TREE_CODE (t1) != POINTER_TYPE
6953 || TREE_CODE (t2) != POINTER_TYPE)
6956 /* Top-level qualifiers don't matter. */
6957 t1 = TYPE_MAIN_VARIANT (t1);
6958 t2 = TYPE_MAIN_VARIANT (t2);
6959 casts_away_constness_r (&t1, &t2);
6960 if (!can_convert (t2, t1))
6966 /* If T is a REFERENCE_TYPE return the type to which T refers.
6967 Otherwise, return T itself. */
6970 non_reference (tree t)
6972 if (TREE_CODE (t) == REFERENCE_TYPE)
6978 /* Return nonzero if REF is an lvalue valid for this language;
6979 otherwise, print an error message and return zero. USE says
6980 how the lvalue is being used and so selects the error message. */
6983 lvalue_or_else (tree ref, enum lvalue_use use)
6985 int win = lvalue_p (ref);