1 /* Build expressions with type checking for C++ compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA. */
24 /* This file is part of the C++ front end.
25 It contains routines to build C++ expressions given their operands,
26 including computing the types of the result, C and C++ specific error
27 checks, and some optimization. */
31 #include "coretypes.h"
41 #include "diagnostic.h"
46 static tree pfn_from_ptrmemfunc (tree);
47 static tree convert_for_assignment (tree, tree, const char *, tree, int);
48 static tree cp_pointer_int_sum (enum tree_code, tree, tree);
49 static tree rationalize_conditional_expr (enum tree_code, tree);
50 static int comp_ptr_ttypes_real (tree, tree, int);
51 static bool comp_except_types (tree, tree, bool);
52 static bool comp_array_types (tree, tree, bool);
53 static tree common_base_type (tree, tree);
54 static tree pointer_diff (tree, tree, tree);
55 static tree get_delta_difference (tree, tree, bool, bool);
56 static void casts_away_constness_r (tree *, tree *);
57 static bool casts_away_constness (tree, tree);
58 static void maybe_warn_about_returning_address_of_local (tree);
59 static tree lookup_destructor (tree, tree, tree);
60 static tree convert_arguments (tree, tree, tree, int);
62 /* Do `exp = require_complete_type (exp);' to make sure exp
63 does not have an incomplete type. (That includes void types.)
64 Returns the error_mark_node if the VALUE does not have
65 complete type when this function returns. */
68 require_complete_type (tree value)
72 if (processing_template_decl || value == error_mark_node)
75 if (TREE_CODE (value) == OVERLOAD)
76 type = unknown_type_node;
78 type = TREE_TYPE (value);
80 if (type == error_mark_node)
81 return error_mark_node;
83 /* First, detect a valid value with a complete type. */
84 if (COMPLETE_TYPE_P (type))
87 if (complete_type_or_else (type, value))
90 return error_mark_node;
93 /* Try to complete TYPE, if it is incomplete. For example, if TYPE is
94 a template instantiation, do the instantiation. Returns TYPE,
95 whether or not it could be completed, unless something goes
96 horribly wrong, in which case the error_mark_node is returned. */
99 complete_type (tree type)
101 if (type == NULL_TREE)
102 /* Rather than crash, we return something sure to cause an error
104 return error_mark_node;
106 if (type == error_mark_node || COMPLETE_TYPE_P (type))
108 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
110 tree t = complete_type (TREE_TYPE (type));
111 unsigned int needs_constructing, has_nontrivial_dtor;
112 if (COMPLETE_TYPE_P (t) && !dependent_type_p (type))
115 = TYPE_NEEDS_CONSTRUCTING (TYPE_MAIN_VARIANT (t));
117 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TYPE_MAIN_VARIANT (t));
118 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
120 TYPE_NEEDS_CONSTRUCTING (t) = needs_constructing;
121 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = has_nontrivial_dtor;
124 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
125 instantiate_class_template (TYPE_MAIN_VARIANT (type));
130 /* Like complete_type, but issue an error if the TYPE cannot be completed.
131 VALUE is used for informative diagnostics.
132 Returns NULL_TREE if the type cannot be made complete. */
135 complete_type_or_else (tree type, tree value)
137 type = complete_type (type);
138 if (type == error_mark_node)
139 /* We already issued an error. */
141 else if (!COMPLETE_TYPE_P (type))
143 cxx_incomplete_type_diagnostic (value, type, 0);
150 /* Return truthvalue of whether type of EXP is instantiated. */
153 type_unknown_p (tree exp)
155 return (TREE_CODE (exp) == TREE_LIST
156 || TREE_TYPE (exp) == unknown_type_node);
160 /* Return the common type of two parameter lists.
161 We assume that comptypes has already been done and returned 1;
162 if that isn't so, this may crash.
164 As an optimization, free the space we allocate if the parameter
165 lists are already common. */
168 commonparms (tree p1, tree p2)
170 tree oldargs = p1, newargs, n;
174 len = list_length (p1);
175 newargs = tree_last (p1);
177 if (newargs == void_list_node)
186 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
191 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n), i++)
193 if (TREE_PURPOSE (p1) && !TREE_PURPOSE (p2))
195 TREE_PURPOSE (n) = TREE_PURPOSE (p1);
198 else if (! TREE_PURPOSE (p1))
200 if (TREE_PURPOSE (p2))
202 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
208 if (1 != simple_cst_equal (TREE_PURPOSE (p1), TREE_PURPOSE (p2)))
210 TREE_PURPOSE (n) = TREE_PURPOSE (p2);
212 if (TREE_VALUE (p1) != TREE_VALUE (p2))
215 TREE_VALUE (n) = merge_types (TREE_VALUE (p1), TREE_VALUE (p2));
218 TREE_VALUE (n) = TREE_VALUE (p1);
226 /* Given a type, perhaps copied for a typedef,
227 find the "original" version of it. */
229 original_type (tree t)
231 int quals = cp_type_quals (t);
232 while (t != error_mark_node
233 && TYPE_NAME (t) != NULL_TREE)
235 tree x = TYPE_NAME (t);
236 if (TREE_CODE (x) != TYPE_DECL)
238 x = DECL_ORIGINAL_TYPE (x);
243 return cp_build_qualified_type (t, quals);
246 /* T1 and T2 are arithmetic or enumeration types. Return the type
247 that will result from the "usual arithmetic conversions" on T1 and
248 T2 as described in [expr]. */
251 type_after_usual_arithmetic_conversions (tree t1, tree t2)
253 enum tree_code code1 = TREE_CODE (t1);
254 enum tree_code code2 = TREE_CODE (t2);
257 /* FIXME: Attributes. */
258 gcc_assert (ARITHMETIC_TYPE_P (t1)
259 || TREE_CODE (t1) == VECTOR_TYPE
260 || TREE_CODE (t1) == ENUMERAL_TYPE);
261 gcc_assert (ARITHMETIC_TYPE_P (t2)
262 || TREE_CODE (t2) == VECTOR_TYPE
263 || TREE_CODE (t2) == ENUMERAL_TYPE);
265 /* In what follows, we slightly generalize the rules given in [expr] so
266 as to deal with `long long' and `complex'. First, merge the
268 attributes = (*targetm.merge_type_attributes) (t1, t2);
270 /* If one type is complex, form the common type of the non-complex
271 components, then make that complex. Use T1 or T2 if it is the
273 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
275 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
276 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
278 = type_after_usual_arithmetic_conversions (subtype1, subtype2);
280 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
281 return build_type_attribute_variant (t1, attributes);
282 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
283 return build_type_attribute_variant (t2, attributes);
285 return build_type_attribute_variant (build_complex_type (subtype),
289 if (code1 == VECTOR_TYPE)
291 /* When we get here we should have two vectors of the same size.
292 Just prefer the unsigned one if present. */
293 if (TYPE_UNSIGNED (t1))
294 return build_type_attribute_variant (t1, attributes);
296 return build_type_attribute_variant (t2, attributes);
299 /* If only one is real, use it as the result. */
300 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
301 return build_type_attribute_variant (t1, attributes);
302 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
303 return build_type_attribute_variant (t2, attributes);
305 /* Perform the integral promotions. */
306 if (code1 != REAL_TYPE)
308 t1 = type_promotes_to (t1);
309 t2 = type_promotes_to (t2);
312 /* Both real or both integers; use the one with greater precision. */
313 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
314 return build_type_attribute_variant (t1, attributes);
315 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
316 return build_type_attribute_variant (t2, attributes);
318 /* The types are the same; no need to do anything fancy. */
319 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
320 return build_type_attribute_variant (t1, attributes);
322 if (code1 != REAL_TYPE)
324 /* If one is a sizetype, use it so size_binop doesn't blow up. */
325 if (TYPE_IS_SIZETYPE (t1) > TYPE_IS_SIZETYPE (t2))
326 return build_type_attribute_variant (t1, attributes);
327 if (TYPE_IS_SIZETYPE (t2) > TYPE_IS_SIZETYPE (t1))
328 return build_type_attribute_variant (t2, attributes);
330 /* If one is unsigned long long, then convert the other to unsigned
332 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_unsigned_type_node)
333 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_unsigned_type_node))
334 return build_type_attribute_variant (long_long_unsigned_type_node,
336 /* If one is a long long, and the other is an unsigned long, and
337 long long can represent all the values of an unsigned long, then
338 convert to a long long. Otherwise, convert to an unsigned long
339 long. Otherwise, if either operand is long long, convert the
342 Since we're here, we know the TYPE_PRECISION is the same;
343 therefore converting to long long cannot represent all the values
344 of an unsigned long, so we choose unsigned long long in that
346 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_long_integer_type_node)
347 || same_type_p (TYPE_MAIN_VARIANT (t2), long_long_integer_type_node))
349 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
350 ? long_long_unsigned_type_node
351 : long_long_integer_type_node);
352 return build_type_attribute_variant (t, attributes);
355 /* Go through the same procedure, but for longs. */
356 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_unsigned_type_node)
357 || same_type_p (TYPE_MAIN_VARIANT (t2), long_unsigned_type_node))
358 return build_type_attribute_variant (long_unsigned_type_node,
360 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_integer_type_node)
361 || same_type_p (TYPE_MAIN_VARIANT (t2), long_integer_type_node))
363 tree t = ((TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
364 ? long_unsigned_type_node : long_integer_type_node);
365 return build_type_attribute_variant (t, attributes);
367 /* Otherwise prefer the unsigned one. */
368 if (TYPE_UNSIGNED (t1))
369 return build_type_attribute_variant (t1, attributes);
371 return build_type_attribute_variant (t2, attributes);
375 if (same_type_p (TYPE_MAIN_VARIANT (t1), long_double_type_node)
376 || same_type_p (TYPE_MAIN_VARIANT (t2), long_double_type_node))
377 return build_type_attribute_variant (long_double_type_node,
379 if (same_type_p (TYPE_MAIN_VARIANT (t1), double_type_node)
380 || same_type_p (TYPE_MAIN_VARIANT (t2), double_type_node))
381 return build_type_attribute_variant (double_type_node,
383 if (same_type_p (TYPE_MAIN_VARIANT (t1), float_type_node)
384 || same_type_p (TYPE_MAIN_VARIANT (t2), float_type_node))
385 return build_type_attribute_variant (float_type_node,
388 /* Two floating-point types whose TYPE_MAIN_VARIANTs are none of
389 the standard C++ floating-point types. Logic earlier in this
390 function has already eliminated the possibility that
391 TYPE_PRECISION (t2) != TYPE_PRECISION (t1), so there's no
392 compelling reason to choose one or the other. */
393 return build_type_attribute_variant (t1, attributes);
397 /* Subroutine of composite_pointer_type to implement the recursive
398 case. See that function for documentation fo the parameters. */
401 composite_pointer_type_r (tree t1, tree t2, const char* location)
408 /* Determine the types pointed to by T1 and T2. */
409 if (TREE_CODE (t1) == POINTER_TYPE)
411 pointee1 = TREE_TYPE (t1);
412 pointee2 = TREE_TYPE (t2);
416 pointee1 = TYPE_PTRMEM_POINTED_TO_TYPE (t1);
417 pointee2 = TYPE_PTRMEM_POINTED_TO_TYPE (t2);
422 Otherwise, the composite pointer type is a pointer type
423 similar (_conv.qual_) to the type of one of the operands,
424 with a cv-qualification signature (_conv.qual_) that is the
425 union of the cv-qualification signatures of the operand
427 if (same_type_ignoring_top_level_qualifiers_p (pointee1, pointee2))
428 result_type = pointee1;
429 else if ((TREE_CODE (pointee1) == POINTER_TYPE
430 && TREE_CODE (pointee2) == POINTER_TYPE)
431 || (TYPE_PTR_TO_MEMBER_P (pointee1)
432 && TYPE_PTR_TO_MEMBER_P (pointee2)))
433 result_type = composite_pointer_type_r (pointee1, pointee2, location);
436 pedwarn ("%s between distinct pointer types %qT and %qT "
439 result_type = void_type_node;
441 result_type = cp_build_qualified_type (result_type,
442 (cp_type_quals (pointee1)
443 | cp_type_quals (pointee2)));
444 /* If the original types were pointers to members, so is the
446 if (TYPE_PTR_TO_MEMBER_P (t1))
448 if (!same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
449 TYPE_PTRMEM_CLASS_TYPE (t2)))
450 pedwarn ("%s between distinct pointer types %qT and %qT "
453 result_type = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
457 result_type = build_pointer_type (result_type);
459 /* Merge the attributes. */
460 attributes = (*targetm.merge_type_attributes) (t1, t2);
461 return build_type_attribute_variant (result_type, attributes);
464 /* Return the composite pointer type (see [expr.rel]) for T1 and T2.
465 ARG1 and ARG2 are the values with those types. The LOCATION is a
466 string describing the current location, in case an error occurs.
468 This routine also implements the computation of a common type for
469 pointers-to-members as per [expr.eq]. */
472 composite_pointer_type (tree t1, tree t2, tree arg1, tree arg2,
473 const char* location)
480 If one operand is a null pointer constant, the composite pointer
481 type is the type of the other operand. */
482 if (null_ptr_cst_p (arg1))
484 if (null_ptr_cst_p (arg2))
491 If one of the operands has type "pointer to cv1 void*", then
492 the other has type "pointer to cv2T", and the composite pointer
493 type is "pointer to cv12 void", where cv12 is the union of cv1
496 If either type is a pointer to void, make sure it is T1. */
497 if (TREE_CODE (t2) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t2)))
505 /* Now, if T1 is a pointer to void, merge the qualifiers. */
506 if (TREE_CODE (t1) == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (t1)))
511 if (pedantic && TYPE_PTRFN_P (t2))
512 pedwarn ("ISO C++ forbids %s between pointer of type %<void *%> "
513 "and pointer-to-function", location);
515 = cp_build_qualified_type (void_type_node,
516 (cp_type_quals (TREE_TYPE (t1))
517 | cp_type_quals (TREE_TYPE (t2))));
518 result_type = build_pointer_type (result_type);
519 /* Merge the attributes. */
520 attributes = (*targetm.merge_type_attributes) (t1, t2);
521 return build_type_attribute_variant (result_type, attributes);
524 if (c_dialect_objc () && TREE_CODE (t1) == POINTER_TYPE
525 && TREE_CODE (t2) == POINTER_TYPE)
527 if (objc_compare_types (t1, t2, -3, NULL_TREE))
531 /* [expr.eq] permits the application of a pointer conversion to
532 bring the pointers to a common type. */
533 if (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE
534 && CLASS_TYPE_P (TREE_TYPE (t1))
535 && CLASS_TYPE_P (TREE_TYPE (t2))
536 && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (t1),
539 class1 = TREE_TYPE (t1);
540 class2 = TREE_TYPE (t2);
542 if (DERIVED_FROM_P (class1, class2))
543 t2 = (build_pointer_type
544 (cp_build_qualified_type (class1, TYPE_QUALS (class2))));
545 else if (DERIVED_FROM_P (class2, class1))
546 t1 = (build_pointer_type
547 (cp_build_qualified_type (class2, TYPE_QUALS (class1))));
550 error ("%s between distinct pointer types %qT and %qT "
551 "lacks a cast", location, t1, t2);
552 return error_mark_node;
555 /* [expr.eq] permits the application of a pointer-to-member
556 conversion to change the class type of one of the types. */
557 else if (TYPE_PTR_TO_MEMBER_P (t1)
558 && !same_type_p (TYPE_PTRMEM_CLASS_TYPE (t1),
559 TYPE_PTRMEM_CLASS_TYPE (t2)))
561 class1 = TYPE_PTRMEM_CLASS_TYPE (t1);
562 class2 = TYPE_PTRMEM_CLASS_TYPE (t2);
564 if (DERIVED_FROM_P (class1, class2))
565 t1 = build_ptrmem_type (class2, TYPE_PTRMEM_POINTED_TO_TYPE (t1));
566 else if (DERIVED_FROM_P (class2, class1))
567 t2 = build_ptrmem_type (class1, TYPE_PTRMEM_POINTED_TO_TYPE (t2));
570 error ("%s between distinct pointer-to-member types %qT and %qT "
571 "lacks a cast", location, t1, t2);
572 return error_mark_node;
576 return composite_pointer_type_r (t1, t2, location);
579 /* Return the merged type of two types.
580 We assume that comptypes has already been done and returned 1;
581 if that isn't so, this may crash.
583 This just combines attributes and default arguments; any other
584 differences would cause the two types to compare unalike. */
587 merge_types (tree t1, tree t2)
589 enum tree_code code1;
590 enum tree_code code2;
593 /* Save time if the two types are the same. */
596 if (original_type (t1) == original_type (t2))
599 /* If one type is nonsense, use the other. */
600 if (t1 == error_mark_node)
602 if (t2 == error_mark_node)
605 /* Merge the attributes. */
606 attributes = (*targetm.merge_type_attributes) (t1, t2);
608 if (TYPE_PTRMEMFUNC_P (t1))
609 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
610 if (TYPE_PTRMEMFUNC_P (t2))
611 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
613 code1 = TREE_CODE (t1);
614 code2 = TREE_CODE (t2);
620 /* For two pointers, do this recursively on the target type. */
622 tree target = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
623 int quals = cp_type_quals (t1);
625 if (code1 == POINTER_TYPE)
626 t1 = build_pointer_type (target);
628 t1 = build_reference_type (target);
629 t1 = build_type_attribute_variant (t1, attributes);
630 t1 = cp_build_qualified_type (t1, quals);
632 if (TREE_CODE (target) == METHOD_TYPE)
633 t1 = build_ptrmemfunc_type (t1);
642 quals = cp_type_quals (t1);
643 pointee = merge_types (TYPE_PTRMEM_POINTED_TO_TYPE (t1),
644 TYPE_PTRMEM_POINTED_TO_TYPE (t2));
645 t1 = build_ptrmem_type (TYPE_PTRMEM_CLASS_TYPE (t1),
647 t1 = cp_build_qualified_type (t1, quals);
653 tree elt = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
654 /* Save space: see if the result is identical to one of the args. */
655 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
656 return build_type_attribute_variant (t1, attributes);
657 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
658 return build_type_attribute_variant (t2, attributes);
659 /* Merge the element types, and have a size if either arg has one. */
660 t1 = build_cplus_array_type
661 (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
666 /* Function types: prefer the one that specified arg types.
667 If both do, merge the arg types. Also merge the return types. */
669 tree valtype = merge_types (TREE_TYPE (t1), TREE_TYPE (t2));
670 tree p1 = TYPE_ARG_TYPES (t1);
671 tree p2 = TYPE_ARG_TYPES (t2);
674 /* Save space: see if the result is identical to one of the args. */
675 if (valtype == TREE_TYPE (t1) && ! p2)
676 return cp_build_type_attribute_variant (t1, attributes);
677 if (valtype == TREE_TYPE (t2) && ! p1)
678 return cp_build_type_attribute_variant (t2, attributes);
680 /* Simple way if one arg fails to specify argument types. */
681 if (p1 == NULL_TREE || TREE_VALUE (p1) == void_type_node)
683 rval = build_function_type (valtype, p2);
684 if ((raises = TYPE_RAISES_EXCEPTIONS (t2)))
685 rval = build_exception_variant (rval, raises);
686 return cp_build_type_attribute_variant (rval, attributes);
688 raises = TYPE_RAISES_EXCEPTIONS (t1);
689 if (p2 == NULL_TREE || TREE_VALUE (p2) == void_type_node)
691 rval = build_function_type (valtype, p1);
693 rval = build_exception_variant (rval, raises);
694 return cp_build_type_attribute_variant (rval, attributes);
697 rval = build_function_type (valtype, commonparms (p1, p2));
698 t1 = build_exception_variant (rval, raises);
704 /* Get this value the long way, since TYPE_METHOD_BASETYPE
705 is just the main variant of this. */
706 tree basetype = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (t2)));
707 tree raises = TYPE_RAISES_EXCEPTIONS (t1);
710 /* If this was a member function type, get back to the
711 original type of type member function (i.e., without
712 the class instance variable up front. */
713 t1 = build_function_type (TREE_TYPE (t1),
714 TREE_CHAIN (TYPE_ARG_TYPES (t1)));
715 t2 = build_function_type (TREE_TYPE (t2),
716 TREE_CHAIN (TYPE_ARG_TYPES (t2)));
717 t3 = merge_types (t1, t2);
718 t3 = build_method_type_directly (basetype, TREE_TYPE (t3),
719 TYPE_ARG_TYPES (t3));
720 t1 = build_exception_variant (t3, raises);
725 /* There is no need to merge attributes into a TYPENAME_TYPE.
726 When the type is instantiated it will have whatever
727 attributes result from the instantiation. */
733 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
735 else if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
738 return cp_build_type_attribute_variant (t1, attributes);
741 /* Return the common type of two types.
742 We assume that comptypes has already been done and returned 1;
743 if that isn't so, this may crash.
745 This is the type for the result of most arithmetic operations
746 if the operands have the given two types. */
749 common_type (tree t1, tree t2)
751 enum tree_code code1;
752 enum tree_code code2;
754 /* If one type is nonsense, bail. */
755 if (t1 == error_mark_node || t2 == error_mark_node)
756 return error_mark_node;
758 code1 = TREE_CODE (t1);
759 code2 = TREE_CODE (t2);
761 if ((ARITHMETIC_TYPE_P (t1) || code1 == ENUMERAL_TYPE
762 || code1 == VECTOR_TYPE)
763 && (ARITHMETIC_TYPE_P (t2) || code2 == ENUMERAL_TYPE
764 || code2 == VECTOR_TYPE))
765 return type_after_usual_arithmetic_conversions (t1, t2);
767 else if ((TYPE_PTR_P (t1) && TYPE_PTR_P (t2))
768 || (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
769 || (TYPE_PTRMEMFUNC_P (t1) && TYPE_PTRMEMFUNC_P (t2)))
770 return composite_pointer_type (t1, t2, error_mark_node, error_mark_node,
776 /* Compare two exception specifier types for exactness or subsetness, if
777 allowed. Returns false for mismatch, true for match (same, or
780 [except.spec] "If a class X ... objects of class X or any class publicly
781 and unambiguously derived from X. Similarly, if a pointer type Y * ...
782 exceptions of type Y * or that are pointers to any type publicly and
783 unambiguously derived from Y. Otherwise a function only allows exceptions
784 that have the same type ..."
785 This does not mention cv qualifiers and is different to what throw
786 [except.throw] and catch [except.catch] will do. They will ignore the
787 top level cv qualifiers, and allow qualifiers in the pointer to class
790 We implement the letter of the standard. */
793 comp_except_types (tree a, tree b, bool exact)
795 if (same_type_p (a, b))
799 if (cp_type_quals (a) || cp_type_quals (b))
802 if (TREE_CODE (a) == POINTER_TYPE
803 && TREE_CODE (b) == POINTER_TYPE)
807 if (cp_type_quals (a) || cp_type_quals (b))
811 if (TREE_CODE (a) != RECORD_TYPE
812 || TREE_CODE (b) != RECORD_TYPE)
815 if (PUBLICLY_UNIQUELY_DERIVED_P (a, b))
821 /* Return true if TYPE1 and TYPE2 are equivalent exception specifiers.
822 If EXACT is false, T2 can be stricter than T1 (according to 15.4/7),
823 otherwise it must be exact. Exception lists are unordered, but
824 we've already filtered out duplicates. Most lists will be in order,
825 we should try to make use of that. */
828 comp_except_specs (tree t1, tree t2, bool exact)
837 if (t1 == NULL_TREE) /* T1 is ... */
838 return t2 == NULL_TREE || !exact;
839 if (!TREE_VALUE (t1)) /* t1 is EMPTY */
840 return t2 != NULL_TREE && !TREE_VALUE (t2);
841 if (t2 == NULL_TREE) /* T2 is ... */
843 if (TREE_VALUE (t1) && !TREE_VALUE (t2)) /* T2 is EMPTY, T1 is not */
846 /* Neither set is ... or EMPTY, make sure each part of T2 is in T1.
847 Count how many we find, to determine exactness. For exact matching and
848 ordered T1, T2, this is an O(n) operation, otherwise its worst case is
850 for (base = t1; t2 != NULL_TREE; t2 = TREE_CHAIN (t2))
852 for (probe = base; probe != NULL_TREE; probe = TREE_CHAIN (probe))
854 tree a = TREE_VALUE (probe);
855 tree b = TREE_VALUE (t2);
857 if (comp_except_types (a, b, exact))
859 if (probe == base && exact)
860 base = TREE_CHAIN (probe);
865 if (probe == NULL_TREE)
868 return !exact || base == NULL_TREE || length == list_length (t1);
871 /* Compare the array types T1 and T2. ALLOW_REDECLARATION is true if
872 [] can match [size]. */
875 comp_array_types (tree t1, tree t2, bool allow_redeclaration)
884 /* The type of the array elements must be the same. */
885 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
888 d1 = TYPE_DOMAIN (t1);
889 d2 = TYPE_DOMAIN (t2);
894 /* If one of the arrays is dimensionless, and the other has a
895 dimension, they are of different types. However, it is valid to
903 declarations for an array object can specify
904 array types that differ by the presence or absence of a major
905 array bound (_dcl.array_). */
907 return allow_redeclaration;
909 /* Check that the dimensions are the same. */
911 if (!cp_tree_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)))
913 max1 = TYPE_MAX_VALUE (d1);
914 max2 = TYPE_MAX_VALUE (d2);
915 if (processing_template_decl && !abi_version_at_least (2)
916 && !value_dependent_expression_p (max1)
917 && !value_dependent_expression_p (max2))
919 /* With abi-1 we do not fold non-dependent array bounds, (and
920 consequently mangle them incorrectly). We must therefore
921 fold them here, to verify the domains have the same
927 if (!cp_tree_equal (max1, max2))
933 /* Return true if T1 and T2 are related as allowed by STRICT. STRICT
934 is a bitwise-or of the COMPARE_* flags. */
937 comptypes (tree t1, tree t2, int strict)
942 /* Suppress errors caused by previously reported errors. */
943 if (t1 == error_mark_node || t2 == error_mark_node)
946 gcc_assert (TYPE_P (t1) && TYPE_P (t2));
948 /* TYPENAME_TYPEs should be resolved if the qualifying scope is the
949 current instantiation. */
950 if (TREE_CODE (t1) == TYPENAME_TYPE)
952 tree resolved = resolve_typename_type (t1, /*only_current_p=*/true);
954 if (resolved != error_mark_node)
958 if (TREE_CODE (t2) == TYPENAME_TYPE)
960 tree resolved = resolve_typename_type (t2, /*only_current_p=*/true);
962 if (resolved != error_mark_node)
966 /* If either type is the internal version of sizetype, use the
968 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
969 && TYPE_ORIG_SIZE_TYPE (t1))
970 t1 = TYPE_ORIG_SIZE_TYPE (t1);
972 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
973 && TYPE_ORIG_SIZE_TYPE (t2))
974 t2 = TYPE_ORIG_SIZE_TYPE (t2);
976 if (TYPE_PTRMEMFUNC_P (t1))
977 t1 = TYPE_PTRMEMFUNC_FN_TYPE (t1);
978 if (TYPE_PTRMEMFUNC_P (t2))
979 t2 = TYPE_PTRMEMFUNC_FN_TYPE (t2);
981 /* Different classes of types can't be compatible. */
982 if (TREE_CODE (t1) != TREE_CODE (t2))
985 /* Qualifiers must match. For array types, we will check when we
986 recur on the array element types. */
987 if (TREE_CODE (t1) != ARRAY_TYPE
988 && TYPE_QUALS (t1) != TYPE_QUALS (t2))
990 if (TYPE_FOR_JAVA (t1) != TYPE_FOR_JAVA (t2))
993 /* Allow for two different type nodes which have essentially the same
994 definition. Note that we already checked for equality of the type
995 qualifiers (just above). */
997 if (TREE_CODE (t1) != ARRAY_TYPE
998 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
1001 /* Compare the types. Break out if they could be the same. */
1002 switch (TREE_CODE (t1))
1004 case TEMPLATE_TEMPLATE_PARM:
1005 case BOUND_TEMPLATE_TEMPLATE_PARM:
1006 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1007 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1009 if (!comp_template_parms
1010 (DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t1)),
1011 DECL_TEMPLATE_PARMS (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (t2))))
1013 if (TREE_CODE (t1) == TEMPLATE_TEMPLATE_PARM)
1015 /* Don't check inheritance. */
1016 strict = COMPARE_STRICT;
1021 if (TYPE_TEMPLATE_INFO (t1) && TYPE_TEMPLATE_INFO (t2)
1022 && (TYPE_TI_TEMPLATE (t1) == TYPE_TI_TEMPLATE (t2)
1023 || TREE_CODE (t1) == BOUND_TEMPLATE_TEMPLATE_PARM)
1024 && comp_template_args (TYPE_TI_ARGS (t1), TYPE_TI_ARGS (t2)))
1027 if ((strict & COMPARE_BASE) && DERIVED_FROM_P (t1, t2))
1029 else if ((strict & COMPARE_DERIVED) && DERIVED_FROM_P (t2, t1))
1035 if (!comptypes (TYPE_OFFSET_BASETYPE (t1), TYPE_OFFSET_BASETYPE (t2),
1036 strict & ~COMPARE_REDECLARATION))
1038 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1043 case REFERENCE_TYPE:
1044 if (TYPE_MODE (t1) != TYPE_MODE (t2)
1045 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)
1046 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1052 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1054 if (!compparms (TYPE_ARG_TYPES (t1), TYPE_ARG_TYPES (t2)))
1059 /* Target types must match incl. qualifiers. */
1060 if (!comp_array_types (t1, t2, !!(strict & COMPARE_REDECLARATION)))
1064 case TEMPLATE_TYPE_PARM:
1065 if (TEMPLATE_TYPE_IDX (t1) != TEMPLATE_TYPE_IDX (t2)
1066 || TEMPLATE_TYPE_LEVEL (t1) != TEMPLATE_TYPE_LEVEL (t2))
1071 if (!cp_tree_equal (TYPENAME_TYPE_FULLNAME (t1),
1072 TYPENAME_TYPE_FULLNAME (t2)))
1074 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1078 case UNBOUND_CLASS_TEMPLATE:
1079 if (!cp_tree_equal (TYPE_IDENTIFIER (t1), TYPE_IDENTIFIER (t2)))
1081 if (!same_type_p (TYPE_CONTEXT (t1), TYPE_CONTEXT (t2)))
1086 if (!same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1091 if (TYPE_VECTOR_SUBPARTS (t1) != TYPE_VECTOR_SUBPARTS (t2)
1092 || !same_type_p (TREE_TYPE (t1), TREE_TYPE (t2)))
1100 /* If we get here, we know that from a target independent POV the
1101 types are the same. Make sure the target attributes are also
1103 return targetm.comp_type_attributes (t1, t2);
1106 /* Returns 1 if TYPE1 is at least as qualified as TYPE2. */
1109 at_least_as_qualified_p (tree type1, tree type2)
1111 int q1 = cp_type_quals (type1);
1112 int q2 = cp_type_quals (type2);
1114 /* All qualifiers for TYPE2 must also appear in TYPE1. */
1115 return (q1 & q2) == q2;
1118 /* Returns 1 if TYPE1 is more cv-qualified than TYPE2, -1 if TYPE2 is
1119 more cv-qualified that TYPE1, and 0 otherwise. */
1122 comp_cv_qualification (tree type1, tree type2)
1124 int q1 = cp_type_quals (type1);
1125 int q2 = cp_type_quals (type2);
1130 if ((q1 & q2) == q2)
1132 else if ((q1 & q2) == q1)
1138 /* Returns 1 if the cv-qualification signature of TYPE1 is a proper
1139 subset of the cv-qualification signature of TYPE2, and the types
1140 are similar. Returns -1 if the other way 'round, and 0 otherwise. */
1143 comp_cv_qual_signature (tree type1, tree type2)
1145 if (comp_ptr_ttypes_real (type2, type1, -1))
1147 else if (comp_ptr_ttypes_real (type1, type2, -1))
1153 /* If two types share a common base type, return that basetype.
1154 If there is not a unique most-derived base type, this function
1155 returns ERROR_MARK_NODE. */
1158 common_base_type (tree tt1, tree tt2)
1160 tree best = NULL_TREE;
1163 /* If one is a baseclass of another, that's good enough. */
1164 if (UNIQUELY_DERIVED_FROM_P (tt1, tt2))
1166 if (UNIQUELY_DERIVED_FROM_P (tt2, tt1))
1169 /* Otherwise, try to find a unique baseclass of TT1
1170 that is shared by TT2, and follow that down. */
1171 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt1))-1; i >= 0; i--)
1173 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt1), i));
1174 tree trial = common_base_type (basetype, tt2);
1178 if (trial == error_mark_node)
1180 if (best == NULL_TREE)
1182 else if (best != trial)
1183 return error_mark_node;
1188 for (i = BINFO_N_BASE_BINFOS (TYPE_BINFO (tt2))-1; i >= 0; i--)
1190 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (tt2), i));
1191 tree trial = common_base_type (tt1, basetype);
1195 if (trial == error_mark_node)
1197 if (best == NULL_TREE)
1199 else if (best != trial)
1200 return error_mark_node;
1206 /* Subroutines of `comptypes'. */
1208 /* Return true if two parameter type lists PARMS1 and PARMS2 are
1209 equivalent in the sense that functions with those parameter types
1210 can have equivalent types. The two lists must be equivalent,
1211 element by element. */
1214 compparms (tree parms1, tree parms2)
1218 /* An unspecified parmlist matches any specified parmlist
1219 whose argument types don't need default promotions. */
1221 for (t1 = parms1, t2 = parms2;
1223 t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
1225 /* If one parmlist is shorter than the other,
1226 they fail to match. */
1229 if (!same_type_p (TREE_VALUE (t1), TREE_VALUE (t2)))
1236 /* Process a sizeof or alignof expression where the operand is a
1240 cxx_sizeof_or_alignof_type (tree type, enum tree_code op, bool complain)
1245 gcc_assert (op == SIZEOF_EXPR || op == ALIGNOF_EXPR);
1246 if (type == error_mark_node)
1247 return error_mark_node;
1249 type = non_reference (type);
1250 if (TREE_CODE (type) == METHOD_TYPE)
1252 if (complain && (pedantic || warn_pointer_arith))
1253 pedwarn ("invalid application of %qs to a member function",
1254 operator_name_info[(int) op].name);
1255 value = size_one_node;
1258 dependent_p = dependent_type_p (type);
1260 complete_type (type);
1262 /* VLA types will have a non-constant size. In the body of an
1263 uninstantiated template, we don't need to try to compute the
1264 value, because the sizeof expression is not an integral
1265 constant expression in that case. And, if we do try to
1266 compute the value, we'll likely end up with SAVE_EXPRs, which
1267 the template substitution machinery does not expect to see. */
1268 || (processing_template_decl
1269 && COMPLETE_TYPE_P (type)
1270 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST))
1272 value = build_min (op, size_type_node, type);
1273 TREE_READONLY (value) = 1;
1277 return c_sizeof_or_alignof_type (complete_type (type),
1282 /* Process a sizeof expression where the operand is an expression. */
1285 cxx_sizeof_expr (tree e)
1287 if (e == error_mark_node)
1288 return error_mark_node;
1290 if (processing_template_decl)
1292 e = build_min (SIZEOF_EXPR, size_type_node, e);
1293 TREE_SIDE_EFFECTS (e) = 0;
1294 TREE_READONLY (e) = 1;
1299 if (TREE_CODE (e) == COMPONENT_REF
1300 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1301 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1303 error ("invalid application of %<sizeof%> to a bit-field");
1306 else if (is_overloaded_fn (e))
1308 pedwarn ("ISO C++ forbids applying %<sizeof%> to an expression of "
1312 else if (type_unknown_p (e))
1314 cxx_incomplete_type_error (e, TREE_TYPE (e));
1320 return cxx_sizeof_or_alignof_type (e, SIZEOF_EXPR, true);
1323 /* Implement the __alignof keyword: Return the minimum required
1324 alignment of E, measured in bytes. For VAR_DECL's and
1325 FIELD_DECL's return DECL_ALIGN (which can be set from an
1326 "aligned" __attribute__ specification). */
1329 cxx_alignof_expr (tree e)
1333 if (e == error_mark_node)
1334 return error_mark_node;
1336 if (processing_template_decl)
1338 e = build_min (ALIGNOF_EXPR, size_type_node, e);
1339 TREE_SIDE_EFFECTS (e) = 0;
1340 TREE_READONLY (e) = 1;
1345 if (TREE_CODE (e) == VAR_DECL)
1346 t = size_int (DECL_ALIGN_UNIT (e));
1347 else if (TREE_CODE (e) == COMPONENT_REF
1348 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL
1349 && DECL_C_BIT_FIELD (TREE_OPERAND (e, 1)))
1351 error ("invalid application of %<__alignof%> to a bit-field");
1354 else if (TREE_CODE (e) == COMPONENT_REF
1355 && TREE_CODE (TREE_OPERAND (e, 1)) == FIELD_DECL)
1356 t = size_int (DECL_ALIGN_UNIT (TREE_OPERAND (e, 1)));
1357 else if (is_overloaded_fn (e))
1359 pedwarn ("ISO C++ forbids applying %<__alignof%> to an expression of "
1361 if (TREE_CODE (e) == FUNCTION_DECL)
1362 t = size_int (DECL_ALIGN_UNIT (e));
1366 else if (type_unknown_p (e))
1368 cxx_incomplete_type_error (e, TREE_TYPE (e));
1372 return cxx_sizeof_or_alignof_type (TREE_TYPE (e), ALIGNOF_EXPR, true);
1374 return fold_convert (size_type_node, t);
1377 /* Process a sizeof or alignof expression E with code OP where the operand
1378 is an expression. */
1381 cxx_sizeof_or_alignof_expr (tree e, enum tree_code op)
1383 if (op == SIZEOF_EXPR)
1384 return cxx_sizeof_expr (e);
1386 return cxx_alignof_expr (e);
1389 /* EXPR is being used in a context that is not a function call.
1394 The expression can be used only as the left-hand operand of a
1395 member function call.
1397 [expr.mptr.operator]
1399 If the result of .* or ->* is a function, then that result can be
1400 used only as the operand for the function call operator ().
1402 by issuing an error message if appropriate. Returns true iff EXPR
1403 violates these rules. */
1406 invalid_nonstatic_memfn_p (tree expr)
1408 if (TREE_CODE (TREE_TYPE (expr)) == METHOD_TYPE)
1410 error ("invalid use of non-static member function");
1416 /* If EXP is a reference to a bitfield, and the type of EXP does not
1417 match the declared type of the bitfield, return the declared type
1418 of the bitfield. Otherwise, return NULL_TREE. */
1421 is_bitfield_expr_with_lowered_type (tree exp)
1423 switch (TREE_CODE (exp))
1426 if (!is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1)))
1428 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 2));
1431 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 1));
1435 return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
1441 field = TREE_OPERAND (exp, 1);
1442 if (TREE_CODE (field) != FIELD_DECL || !DECL_C_BIT_FIELD (field))
1444 if (same_type_ignoring_top_level_qualifiers_p
1445 (TREE_TYPE (exp), DECL_BIT_FIELD_TYPE (field)))
1447 return DECL_BIT_FIELD_TYPE (field);
1455 /* Like is_bitfield_with_lowered_type, except that if EXP is not a
1456 bitfield with a lowered type, the type of EXP is returned, rather
1460 unlowered_expr_type (tree exp)
1464 type = is_bitfield_expr_with_lowered_type (exp);
1466 type = TREE_TYPE (exp);
1471 /* Perform the conversions in [expr] that apply when an lvalue appears
1472 in an rvalue context: the lvalue-to-rvalue, array-to-pointer, and
1473 function-to-pointer conversions. In addition, manifest constants
1474 are replaced by their values, and bitfield references are converted
1475 to their declared types.
1477 Although the returned value is being used as an rvalue, this
1478 function does not wrap the returned expression in a
1479 NON_LVALUE_EXPR; the caller is expected to be mindful of the fact
1480 that the return value is no longer an lvalue. */
1483 decay_conversion (tree exp)
1486 enum tree_code code;
1488 type = TREE_TYPE (exp);
1489 if (type == error_mark_node)
1490 return error_mark_node;
1492 if (type_unknown_p (exp))
1494 cxx_incomplete_type_error (exp, TREE_TYPE (exp));
1495 return error_mark_node;
1498 exp = decl_constant_value (exp);
1499 if (error_operand_p (exp))
1500 return error_mark_node;
1502 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
1503 Leave such NOP_EXPRs, since RHS is being used in non-lvalue context. */
1504 code = TREE_CODE (type);
1505 if (code == VOID_TYPE)
1507 error ("void value not ignored as it ought to be");
1508 return error_mark_node;
1510 if (invalid_nonstatic_memfn_p (exp))
1511 return error_mark_node;
1512 if (code == FUNCTION_TYPE || is_overloaded_fn (exp))
1513 return build_unary_op (ADDR_EXPR, exp, 0);
1514 if (code == ARRAY_TYPE)
1519 if (TREE_CODE (exp) == INDIRECT_REF)
1520 return build_nop (build_pointer_type (TREE_TYPE (type)),
1521 TREE_OPERAND (exp, 0));
1523 if (TREE_CODE (exp) == COMPOUND_EXPR)
1525 tree op1 = decay_conversion (TREE_OPERAND (exp, 1));
1526 return build2 (COMPOUND_EXPR, TREE_TYPE (op1),
1527 TREE_OPERAND (exp, 0), op1);
1531 && ! (TREE_CODE (exp) == CONSTRUCTOR && TREE_STATIC (exp)))
1533 error ("invalid use of non-lvalue array");
1534 return error_mark_node;
1537 ptrtype = build_pointer_type (TREE_TYPE (type));
1539 if (TREE_CODE (exp) == VAR_DECL)
1541 if (!cxx_mark_addressable (exp))
1542 return error_mark_node;
1543 adr = build_nop (ptrtype, build_address (exp));
1546 /* This way is better for a COMPONENT_REF since it can
1547 simplify the offset for a component. */
1548 adr = build_unary_op (ADDR_EXPR, exp, 1);
1549 return cp_convert (ptrtype, adr);
1552 /* If a bitfield is used in a context where integral promotion
1553 applies, then the caller is expected to have used
1554 default_conversion. That function promotes bitfields correctly
1555 before calling this function. At this point, if we have a
1556 bitfield referenced, we may assume that is not subject to
1557 promotion, and that, therefore, the type of the resulting rvalue
1558 is the declared type of the bitfield. */
1559 exp = convert_bitfield_to_declared_type (exp);
1561 /* We do not call rvalue() here because we do not want to wrap EXP
1562 in a NON_LVALUE_EXPR. */
1566 Non-class rvalues always have cv-unqualified types. */
1567 type = TREE_TYPE (exp);
1568 if (!CLASS_TYPE_P (type) && cp_type_quals (type))
1569 exp = build_nop (TYPE_MAIN_VARIANT (type), exp);
1574 /* Perform prepatory conversions, as part of the "usual arithmetic
1575 conversions". In particular, as per [expr]:
1577 Whenever an lvalue expression appears as an operand of an
1578 operator that expects the rvalue for that operand, the
1579 lvalue-to-rvalue, array-to-pointer, or function-to-pointer
1580 standard conversions are applied to convert the expression to an
1583 In addition, we perform integral promotions here, as those are
1584 applied to both operands to a binary operator before determining
1585 what additional conversions should apply. */
1588 default_conversion (tree exp)
1590 /* Perform the integral promotions first so that bitfield
1591 expressions (which may promote to "int", even if the bitfield is
1592 declared "unsigned") are promoted correctly. */
1593 if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (exp)))
1594 exp = perform_integral_promotions (exp);
1595 /* Perform the other conversions. */
1596 exp = decay_conversion (exp);
1601 /* EXPR is an expression with an integral or enumeration type.
1602 Perform the integral promotions in [conv.prom], and return the
1606 perform_integral_promotions (tree expr)
1613 If the bitfield has an enumerated type, it is treated as any
1614 other value of that type for promotion purposes. */
1615 type = is_bitfield_expr_with_lowered_type (expr);
1616 if (!type || TREE_CODE (type) != ENUMERAL_TYPE)
1617 type = TREE_TYPE (expr);
1618 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
1619 promoted_type = type_promotes_to (type);
1620 if (type != promoted_type)
1621 expr = cp_convert (promoted_type, expr);
1625 /* Take the address of an inline function without setting TREE_ADDRESSABLE
1629 inline_conversion (tree exp)
1631 if (TREE_CODE (exp) == FUNCTION_DECL)
1632 exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
1637 /* Returns nonzero iff exp is a STRING_CST or the result of applying
1638 decay_conversion to one. */
1641 string_conv_p (tree totype, tree exp, int warn)
1645 if (TREE_CODE (totype) != POINTER_TYPE)
1648 t = TREE_TYPE (totype);
1649 if (!same_type_p (t, char_type_node)
1650 && !same_type_p (t, wchar_type_node))
1653 if (TREE_CODE (exp) == STRING_CST)
1655 /* Make sure that we don't try to convert between char and wchar_t. */
1656 if (!same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (exp))), t))
1661 /* Is this a string constant which has decayed to 'const char *'? */
1662 t = build_pointer_type (build_qualified_type (t, TYPE_QUAL_CONST));
1663 if (!same_type_p (TREE_TYPE (exp), t))
1666 if (TREE_CODE (exp) != ADDR_EXPR
1667 || TREE_CODE (TREE_OPERAND (exp, 0)) != STRING_CST)
1671 /* This warning is not very useful, as it complains about printf. */
1673 warning (OPT_Wwrite_strings,
1674 "deprecated conversion from string constant to %qT",
1680 /* Given a COND_EXPR, MIN_EXPR, or MAX_EXPR in T, return it in a form that we
1681 can, for example, use as an lvalue. This code used to be in
1682 unary_complex_lvalue, but we needed it to deal with `a = (d == c) ? b : c'
1683 expressions, where we're dealing with aggregates. But now it's again only
1684 called from unary_complex_lvalue. The case (in particular) that led to
1685 this was with CODE == ADDR_EXPR, since it's not an lvalue when we'd
1689 rationalize_conditional_expr (enum tree_code code, tree t)
1691 /* For MIN_EXPR or MAX_EXPR, fold-const.c has arranged things so that
1692 the first operand is always the one to be used if both operands
1693 are equal, so we know what conditional expression this used to be. */
1694 if (TREE_CODE (t) == MIN_EXPR || TREE_CODE (t) == MAX_EXPR)
1696 tree op0 = TREE_OPERAND (t, 0);
1697 tree op1 = TREE_OPERAND (t, 1);
1699 /* The following code is incorrect if either operand side-effects. */
1700 gcc_assert (!TREE_SIDE_EFFECTS (op0)
1701 && !TREE_SIDE_EFFECTS (op1));
1703 build_conditional_expr (build_x_binary_op ((TREE_CODE (t) == MIN_EXPR
1704 ? LE_EXPR : GE_EXPR),
1705 op0, TREE_CODE (op0),
1706 op1, TREE_CODE (op1),
1707 /*overloaded_p=*/NULL),
1708 build_unary_op (code, op0, 0),
1709 build_unary_op (code, op1, 0));
1713 build_conditional_expr (TREE_OPERAND (t, 0),
1714 build_unary_op (code, TREE_OPERAND (t, 1), 0),
1715 build_unary_op (code, TREE_OPERAND (t, 2), 0));
1718 /* Given the TYPE of an anonymous union field inside T, return the
1719 FIELD_DECL for the field. If not found return NULL_TREE. Because
1720 anonymous unions can nest, we must also search all anonymous unions
1721 that are directly reachable. */
1724 lookup_anon_field (tree t, tree type)
1728 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1730 if (TREE_STATIC (field))
1732 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1735 /* If we find it directly, return the field. */
1736 if (DECL_NAME (field) == NULL_TREE
1737 && type == TYPE_MAIN_VARIANT (TREE_TYPE (field)))
1742 /* Otherwise, it could be nested, search harder. */
1743 if (DECL_NAME (field) == NULL_TREE
1744 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1746 tree subfield = lookup_anon_field (TREE_TYPE (field), type);
1754 /* Build an expression representing OBJECT.MEMBER. OBJECT is an
1755 expression; MEMBER is a DECL or baselink. If ACCESS_PATH is
1756 non-NULL, it indicates the path to the base used to name MEMBER.
1757 If PRESERVE_REFERENCE is true, the expression returned will have
1758 REFERENCE_TYPE if the MEMBER does. Otherwise, the expression
1759 returned will have the type referred to by the reference.
1761 This function does not perform access control; that is either done
1762 earlier by the parser when the name of MEMBER is resolved to MEMBER
1763 itself, or later when overload resolution selects one of the
1764 functions indicated by MEMBER. */
1767 build_class_member_access_expr (tree object, tree member,
1768 tree access_path, bool preserve_reference)
1772 tree result = NULL_TREE;
1774 if (error_operand_p (object) || error_operand_p (member))
1775 return error_mark_node;
1777 gcc_assert (DECL_P (member) || BASELINK_P (member));
1781 The type of the first expression shall be "class object" (of a
1783 object_type = TREE_TYPE (object);
1784 if (!currently_open_class (object_type)
1785 && !complete_type_or_else (object_type, object))
1786 return error_mark_node;
1787 if (!CLASS_TYPE_P (object_type))
1789 error ("request for member %qD in %qE, which is of non-class type %qT",
1790 member, object, object_type);
1791 return error_mark_node;
1794 /* The standard does not seem to actually say that MEMBER must be a
1795 member of OBJECT_TYPE. However, that is clearly what is
1797 if (DECL_P (member))
1799 member_scope = DECL_CLASS_CONTEXT (member);
1801 if (TREE_DEPRECATED (member))
1802 warn_deprecated_use (member);
1805 member_scope = BINFO_TYPE (BASELINK_BINFO (member));
1806 /* If MEMBER is from an anonymous aggregate, MEMBER_SCOPE will
1807 presently be the anonymous union. Go outwards until we find a
1808 type related to OBJECT_TYPE. */
1809 while (ANON_AGGR_TYPE_P (member_scope)
1810 && !same_type_ignoring_top_level_qualifiers_p (member_scope,
1812 member_scope = TYPE_CONTEXT (member_scope);
1813 if (!member_scope || !DERIVED_FROM_P (member_scope, object_type))
1815 if (TREE_CODE (member) == FIELD_DECL)
1816 error ("invalid use of nonstatic data member %qE", member);
1818 error ("%qD is not a member of %qT", member, object_type);
1819 return error_mark_node;
1822 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' into
1823 `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only an lvalue
1824 in the frontend; only _DECLs and _REFs are lvalues in the backend. */
1826 tree temp = unary_complex_lvalue (ADDR_EXPR, object);
1828 object = build_indirect_ref (temp, NULL);
1831 /* In [expr.ref], there is an explicit list of the valid choices for
1832 MEMBER. We check for each of those cases here. */
1833 if (TREE_CODE (member) == VAR_DECL)
1835 /* A static data member. */
1837 /* If OBJECT has side-effects, they are supposed to occur. */
1838 if (TREE_SIDE_EFFECTS (object))
1839 result = build2 (COMPOUND_EXPR, TREE_TYPE (result), object, result);
1841 else if (TREE_CODE (member) == FIELD_DECL)
1843 /* A non-static data member. */
1848 null_object_p = (TREE_CODE (object) == INDIRECT_REF
1849 && integer_zerop (TREE_OPERAND (object, 0)));
1851 /* Convert OBJECT to the type of MEMBER. */
1852 if (!same_type_p (TYPE_MAIN_VARIANT (object_type),
1853 TYPE_MAIN_VARIANT (member_scope)))
1858 binfo = lookup_base (access_path ? access_path : object_type,
1859 member_scope, ba_unique, &kind);
1860 if (binfo == error_mark_node)
1861 return error_mark_node;
1863 /* It is invalid to try to get to a virtual base of a
1864 NULL object. The most common cause is invalid use of
1866 if (null_object_p && kind == bk_via_virtual)
1868 error ("invalid access to non-static data member %qD of "
1871 error ("(perhaps the %<offsetof%> macro was used incorrectly)");
1872 return error_mark_node;
1875 /* Convert to the base. */
1876 object = build_base_path (PLUS_EXPR, object, binfo,
1878 /* If we found the base successfully then we should be able
1879 to convert to it successfully. */
1880 gcc_assert (object != error_mark_node);
1883 /* Complain about other invalid uses of offsetof, even though they will
1884 give the right answer. Note that we complain whether or not they
1885 actually used the offsetof macro, since there's no way to know at this
1886 point. So we just give a warning, instead of a pedwarn. */
1887 /* Do not produce this warning for base class field references, because
1888 we know for a fact that didn't come from offsetof. This does occur
1889 in various testsuite cases where a null object is passed where a
1890 vtable access is required. */
1891 if (null_object_p && warn_invalid_offsetof
1892 && CLASSTYPE_NON_POD_P (object_type)
1893 && !DECL_FIELD_IS_BASE (member)
1894 && !skip_evaluation)
1896 warning (0, "invalid access to non-static data member %qD of NULL object",
1898 warning (0, "(perhaps the %<offsetof%> macro was used incorrectly)");
1901 /* If MEMBER is from an anonymous aggregate, we have converted
1902 OBJECT so that it refers to the class containing the
1903 anonymous union. Generate a reference to the anonymous union
1904 itself, and recur to find MEMBER. */
1905 if (ANON_AGGR_TYPE_P (DECL_CONTEXT (member))
1906 /* When this code is called from build_field_call, the
1907 object already has the type of the anonymous union.
1908 That is because the COMPONENT_REF was already
1909 constructed, and was then disassembled before calling
1910 build_field_call. After the function-call code is
1911 cleaned up, this waste can be eliminated. */
1912 && (!same_type_ignoring_top_level_qualifiers_p
1913 (TREE_TYPE (object), DECL_CONTEXT (member))))
1915 tree anonymous_union;
1917 anonymous_union = lookup_anon_field (TREE_TYPE (object),
1918 DECL_CONTEXT (member));
1919 object = build_class_member_access_expr (object,
1921 /*access_path=*/NULL_TREE,
1922 preserve_reference);
1925 /* Compute the type of the field, as described in [expr.ref]. */
1926 type_quals = TYPE_UNQUALIFIED;
1927 member_type = TREE_TYPE (member);
1928 if (TREE_CODE (member_type) != REFERENCE_TYPE)
1930 type_quals = (cp_type_quals (member_type)
1931 | cp_type_quals (object_type));
1933 /* A field is const (volatile) if the enclosing object, or the
1934 field itself, is const (volatile). But, a mutable field is
1935 not const, even within a const object. */
1936 if (DECL_MUTABLE_P (member))
1937 type_quals &= ~TYPE_QUAL_CONST;
1938 member_type = cp_build_qualified_type (member_type, type_quals);
1941 result = build3 (COMPONENT_REF, member_type, object, member,
1943 result = fold_if_not_in_template (result);
1945 /* Mark the expression const or volatile, as appropriate. Even
1946 though we've dealt with the type above, we still have to mark the
1947 expression itself. */
1948 if (type_quals & TYPE_QUAL_CONST)
1949 TREE_READONLY (result) = 1;
1950 if (type_quals & TYPE_QUAL_VOLATILE)
1951 TREE_THIS_VOLATILE (result) = 1;
1953 else if (BASELINK_P (member))
1955 /* The member is a (possibly overloaded) member function. */
1959 /* If the MEMBER is exactly one static member function, then we
1960 know the type of the expression. Otherwise, we must wait
1961 until overload resolution has been performed. */
1962 functions = BASELINK_FUNCTIONS (member);
1963 if (TREE_CODE (functions) == FUNCTION_DECL
1964 && DECL_STATIC_FUNCTION_P (functions))
1965 type = TREE_TYPE (functions);
1967 type = unknown_type_node;
1968 /* Note that we do not convert OBJECT to the BASELINK_BINFO
1969 base. That will happen when the function is called. */
1970 result = build3 (COMPONENT_REF, type, object, member, NULL_TREE);
1972 else if (TREE_CODE (member) == CONST_DECL)
1974 /* The member is an enumerator. */
1976 /* If OBJECT has side-effects, they are supposed to occur. */
1977 if (TREE_SIDE_EFFECTS (object))
1978 result = build2 (COMPOUND_EXPR, TREE_TYPE (result),
1983 error ("invalid use of %qD", member);
1984 return error_mark_node;
1987 if (!preserve_reference)
1990 If E2 is declared to have type "reference to T", then ... the
1991 type of E1.E2 is T. */
1992 result = convert_from_reference (result);
1997 /* Return the destructor denoted by OBJECT.SCOPE::~DTOR_NAME, or, if
1998 SCOPE is NULL, by OBJECT.~DTOR_NAME. */
2001 lookup_destructor (tree object, tree scope, tree dtor_name)
2003 tree object_type = TREE_TYPE (object);
2004 tree dtor_type = TREE_OPERAND (dtor_name, 0);
2007 if (scope && !check_dtor_name (scope, dtor_type))
2009 error ("qualified type %qT does not match destructor name ~%qT",
2011 return error_mark_node;
2013 if (!DERIVED_FROM_P (dtor_type, TYPE_MAIN_VARIANT (object_type)))
2015 error ("the type being destroyed is %qT, but the destructor refers to %qT",
2016 TYPE_MAIN_VARIANT (object_type), dtor_type);
2017 return error_mark_node;
2019 expr = lookup_member (dtor_type, complete_dtor_identifier,
2020 /*protect=*/1, /*want_type=*/false);
2021 expr = (adjust_result_of_qualified_name_lookup
2022 (expr, dtor_type, object_type));
2026 /* An expression of the form "A::template B" has been resolved to
2027 DECL. Issue a diagnostic if B is not a template or template
2031 check_template_keyword (tree decl)
2033 /* The standard says:
2037 If a name prefixed by the keyword template is not a member
2038 template, the program is ill-formed.
2040 DR 228 removed the restriction that the template be a member
2043 DR 96, if accepted would add the further restriction that explicit
2044 template arguments must be provided if the template keyword is
2045 used, but, as of 2005-10-16, that DR is still in "drafting". If
2046 this DR is accepted, then the semantic checks here can be
2047 simplified, as the entity named must in fact be a template
2048 specialization, rather than, as at present, a set of overloaded
2049 functions containing at least one template function. */
2050 if (TREE_CODE (decl) != TEMPLATE_DECL
2051 && TREE_CODE (decl) != TEMPLATE_ID_EXPR)
2053 if (!is_overloaded_fn (decl))
2054 pedwarn ("%qD is not a template", decl);
2059 if (BASELINK_P (fns))
2060 fns = BASELINK_FUNCTIONS (fns);
2063 tree fn = OVL_CURRENT (fns);
2064 if (TREE_CODE (fn) == TEMPLATE_DECL
2065 || TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2067 if (TREE_CODE (fn) == FUNCTION_DECL
2068 && DECL_USE_TEMPLATE (fn)
2069 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
2071 fns = OVL_NEXT (fns);
2074 pedwarn ("%qD is not a template", decl);
2079 /* This function is called by the parser to process a class member
2080 access expression of the form OBJECT.NAME. NAME is a node used by
2081 the parser to represent a name; it is not yet a DECL. It may,
2082 however, be a BASELINK where the BASELINK_FUNCTIONS is a
2083 TEMPLATE_ID_EXPR. Templates must be looked up by the parser, and
2084 there is no reason to do the lookup twice, so the parser keeps the
2085 BASELINK. TEMPLATE_P is true iff NAME was explicitly declared to
2086 be a template via the use of the "A::template B" syntax. */
2089 finish_class_member_access_expr (tree object, tree name, bool template_p)
2094 tree access_path = NULL_TREE;
2095 tree orig_object = object;
2096 tree orig_name = name;
2098 if (object == error_mark_node || name == error_mark_node)
2099 return error_mark_node;
2101 /* If OBJECT is an ObjC class instance, we must obey ObjC access rules. */
2102 if (!objc_is_public (object, name))
2103 return error_mark_node;
2105 object_type = TREE_TYPE (object);
2107 if (processing_template_decl)
2109 if (/* If OBJECT_TYPE is dependent, so is OBJECT.NAME. */
2110 dependent_type_p (object_type)
2111 /* If NAME is just an IDENTIFIER_NODE, then the expression
2113 || TREE_CODE (object) == IDENTIFIER_NODE
2114 /* If NAME is "f<args>", where either 'f' or 'args' is
2115 dependent, then the expression is dependent. */
2116 || (TREE_CODE (name) == TEMPLATE_ID_EXPR
2117 && dependent_template_id_p (TREE_OPERAND (name, 0),
2118 TREE_OPERAND (name, 1)))
2119 /* If NAME is "T::X" where "T" is dependent, then the
2120 expression is dependent. */
2121 || (TREE_CODE (name) == SCOPE_REF
2122 && TYPE_P (TREE_OPERAND (name, 0))
2123 && dependent_type_p (TREE_OPERAND (name, 0))))
2124 return build_min_nt (COMPONENT_REF, object, name, NULL_TREE);
2125 object = build_non_dependent_expr (object);
2130 The type of the first expression shall be "class object" (of a
2132 if (!currently_open_class (object_type)
2133 && !complete_type_or_else (object_type, object))
2134 return error_mark_node;
2135 if (!CLASS_TYPE_P (object_type))
2137 error ("request for member %qD in %qE, which is of non-class type %qT",
2138 name, object, object_type);
2139 return error_mark_node;
2142 if (BASELINK_P (name))
2143 /* A member function that has already been looked up. */
2147 bool is_template_id = false;
2148 tree template_args = NULL_TREE;
2151 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
2153 is_template_id = true;
2154 template_args = TREE_OPERAND (name, 1);
2155 name = TREE_OPERAND (name, 0);
2157 if (TREE_CODE (name) == OVERLOAD)
2158 name = DECL_NAME (get_first_fn (name));
2159 else if (DECL_P (name))
2160 name = DECL_NAME (name);
2163 if (TREE_CODE (name) == SCOPE_REF)
2165 /* A qualified name. The qualifying class or namespace `S'
2166 has already been looked up; it is either a TYPE or a
2168 scope = TREE_OPERAND (name, 0);
2169 name = TREE_OPERAND (name, 1);
2171 /* If SCOPE is a namespace, then the qualified name does not
2172 name a member of OBJECT_TYPE. */
2173 if (TREE_CODE (scope) == NAMESPACE_DECL)
2175 error ("%<%D::%D%> is not a member of %qT",
2176 scope, name, object_type);
2177 return error_mark_node;
2180 gcc_assert (CLASS_TYPE_P (scope));
2181 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE
2182 || TREE_CODE (name) == BIT_NOT_EXPR);
2184 /* Find the base of OBJECT_TYPE corresponding to SCOPE. */
2185 access_path = lookup_base (object_type, scope, ba_check, NULL);
2186 if (access_path == error_mark_node)
2187 return error_mark_node;
2190 error ("%qT is not a base of %qT", scope, object_type);
2191 return error_mark_node;
2197 access_path = object_type;
2200 if (TREE_CODE (name) == BIT_NOT_EXPR)
2201 member = lookup_destructor (object, scope, name);
2204 /* Look up the member. */
2205 member = lookup_member (access_path, name, /*protect=*/1,
2206 /*want_type=*/false);
2207 if (member == NULL_TREE)
2209 error ("%qD has no member named %qE", object_type, name);
2210 return error_mark_node;
2212 if (member == error_mark_node)
2213 return error_mark_node;
2218 tree template = member;
2220 if (BASELINK_P (template))
2221 template = lookup_template_function (template, template_args);
2224 error ("%qD is not a member template function", name);
2225 return error_mark_node;
2230 if (TREE_DEPRECATED (member))
2231 warn_deprecated_use (member);
2234 check_template_keyword (member);
2236 expr = build_class_member_access_expr (object, member, access_path,
2237 /*preserve_reference=*/false);
2238 if (processing_template_decl && expr != error_mark_node)
2240 if (BASELINK_P (member))
2242 if (TREE_CODE (orig_name) == SCOPE_REF)
2243 BASELINK_QUALIFIED_P (member) = 1;
2246 return build_min_non_dep (COMPONENT_REF, expr,
2247 orig_object, orig_name,
2254 /* Return an expression for the MEMBER_NAME field in the internal
2255 representation of PTRMEM, a pointer-to-member function. (Each
2256 pointer-to-member function type gets its own RECORD_TYPE so it is
2257 more convenient to access the fields by name than by FIELD_DECL.)
2258 This routine converts the NAME to a FIELD_DECL and then creates the
2259 node for the complete expression. */
2262 build_ptrmemfunc_access_expr (tree ptrmem, tree member_name)
2268 /* This code is a stripped down version of
2269 build_class_member_access_expr. It does not work to use that
2270 routine directly because it expects the object to be of class
2272 ptrmem_type = TREE_TYPE (ptrmem);
2273 gcc_assert (TYPE_PTRMEMFUNC_P (ptrmem_type));
2274 member = lookup_member (ptrmem_type, member_name, /*protect=*/0,
2275 /*want_type=*/false);
2276 member_type = cp_build_qualified_type (TREE_TYPE (member),
2277 cp_type_quals (ptrmem_type));
2278 return fold_build3 (COMPONENT_REF, member_type,
2279 ptrmem, member, NULL_TREE);
2282 /* Given an expression PTR for a pointer, return an expression
2283 for the value pointed to.
2284 ERRORSTRING is the name of the operator to appear in error messages.
2286 This function may need to overload OPERATOR_FNNAME.
2287 Must also handle REFERENCE_TYPEs for C++. */
2290 build_x_indirect_ref (tree expr, const char *errorstring)
2292 tree orig_expr = expr;
2295 if (processing_template_decl)
2297 if (type_dependent_expression_p (expr))
2298 return build_min_nt (INDIRECT_REF, expr);
2299 expr = build_non_dependent_expr (expr);
2302 rval = build_new_op (INDIRECT_REF, LOOKUP_NORMAL, expr, NULL_TREE,
2303 NULL_TREE, /*overloaded_p=*/NULL);
2305 rval = build_indirect_ref (expr, errorstring);
2307 if (processing_template_decl && rval != error_mark_node)
2308 return build_min_non_dep (INDIRECT_REF, rval, orig_expr);
2314 build_indirect_ref (tree ptr, const char *errorstring)
2318 if (ptr == error_mark_node)
2319 return error_mark_node;
2321 if (ptr == current_class_ptr)
2322 return current_class_ref;
2324 pointer = (TREE_CODE (TREE_TYPE (ptr)) == REFERENCE_TYPE
2325 ? ptr : decay_conversion (ptr));
2326 type = TREE_TYPE (pointer);
2328 if (POINTER_TYPE_P (type))
2332 If the type of the expression is "pointer to T," the type
2333 of the result is "T."
2335 We must use the canonical variant because certain parts of
2336 the back end, like fold, do pointer comparisons between
2338 tree t = canonical_type_variant (TREE_TYPE (type));
2340 if (TREE_CODE (ptr) == CONVERT_EXPR
2341 || TREE_CODE (ptr) == NOP_EXPR
2342 || TREE_CODE (ptr) == VIEW_CONVERT_EXPR)
2344 /* If a warning is issued, mark it to avoid duplicates from
2345 the backend. This only needs to be done at
2346 warn_strict_aliasing > 2. */
2347 if (warn_strict_aliasing > 2)
2348 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (ptr, 0)),
2349 type, TREE_OPERAND (ptr, 0)))
2350 TREE_NO_WARNING (ptr) = 1;
2353 if (VOID_TYPE_P (t))
2355 /* A pointer to incomplete type (other than cv void) can be
2356 dereferenced [expr.unary.op]/1 */
2357 error ("%qT is not a pointer-to-object type", type);
2358 return error_mark_node;
2360 else if (TREE_CODE (pointer) == ADDR_EXPR
2361 && same_type_p (t, TREE_TYPE (TREE_OPERAND (pointer, 0))))
2362 /* The POINTER was something like `&x'. We simplify `*&x' to
2364 return TREE_OPERAND (pointer, 0);
2367 tree ref = build1 (INDIRECT_REF, t, pointer);
2369 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2370 so that we get the proper error message if the result is used
2371 to assign to. Also, &* is supposed to be a no-op. */
2372 TREE_READONLY (ref) = CP_TYPE_CONST_P (t);
2373 TREE_THIS_VOLATILE (ref) = CP_TYPE_VOLATILE_P (t);
2374 TREE_SIDE_EFFECTS (ref)
2375 = (TREE_THIS_VOLATILE (ref) || TREE_SIDE_EFFECTS (pointer));
2379 /* `pointer' won't be an error_mark_node if we were given a
2380 pointer to member, so it's cool to check for this here. */
2381 else if (TYPE_PTR_TO_MEMBER_P (type))
2382 error ("invalid use of %qs on pointer to member", errorstring);
2383 else if (pointer != error_mark_node)
2386 error ("invalid type argument of %qs", errorstring);
2388 error ("invalid type argument");
2390 return error_mark_node;
2393 /* This handles expressions of the form "a[i]", which denotes
2396 This is logically equivalent in C to *(a+i), but we may do it differently.
2397 If A is a variable or a member, we generate a primitive ARRAY_REF.
2398 This avoids forcing the array out of registers, and can work on
2399 arrays that are not lvalues (for example, members of structures returned
2402 If INDEX is of some user-defined type, it must be converted to
2403 integer type. Otherwise, to make a compatible PLUS_EXPR, it
2404 will inherit the type of the array, which will be some pointer type. */
2407 build_array_ref (tree array, tree idx)
2411 error ("subscript missing in array reference");
2412 return error_mark_node;
2415 if (TREE_TYPE (array) == error_mark_node
2416 || TREE_TYPE (idx) == error_mark_node)
2417 return error_mark_node;
2419 /* If ARRAY is a COMPOUND_EXPR or COND_EXPR, move our reference
2421 switch (TREE_CODE (array))
2425 tree value = build_array_ref (TREE_OPERAND (array, 1), idx);
2426 return build2 (COMPOUND_EXPR, TREE_TYPE (value),
2427 TREE_OPERAND (array, 0), value);
2431 return build_conditional_expr
2432 (TREE_OPERAND (array, 0),
2433 build_array_ref (TREE_OPERAND (array, 1), idx),
2434 build_array_ref (TREE_OPERAND (array, 2), idx));
2440 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2444 warn_array_subscript_with_type_char (idx);
2446 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (idx)))
2448 error ("array subscript is not an integer");
2449 return error_mark_node;
2452 /* Apply integral promotions *after* noticing character types.
2453 (It is unclear why we do these promotions -- the standard
2454 does not say that we should. In fact, the natural thing would
2455 seem to be to convert IDX to ptrdiff_t; we're performing
2456 pointer arithmetic.) */
2457 idx = perform_integral_promotions (idx);
2459 /* An array that is indexed by a non-constant
2460 cannot be stored in a register; we must be able to do
2461 address arithmetic on its address.
2462 Likewise an array of elements of variable size. */
2463 if (TREE_CODE (idx) != INTEGER_CST
2464 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2465 && (TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array))))
2468 if (!cxx_mark_addressable (array))
2469 return error_mark_node;
2472 /* An array that is indexed by a constant value which is not within
2473 the array bounds cannot be stored in a register either; because we
2474 would get a crash in store_bit_field/extract_bit_field when trying
2475 to access a non-existent part of the register. */
2476 if (TREE_CODE (idx) == INTEGER_CST
2477 && TYPE_DOMAIN (TREE_TYPE (array))
2478 && ! int_fits_type_p (idx, TYPE_DOMAIN (TREE_TYPE (array))))
2480 if (!cxx_mark_addressable (array))
2481 return error_mark_node;
2484 if (pedantic && !lvalue_p (array))
2485 pedwarn ("ISO C++ forbids subscripting non-lvalue array");
2487 /* Note in C++ it is valid to subscript a `register' array, since
2488 it is valid to take the address of something with that
2489 storage specification. */
2493 while (TREE_CODE (foo) == COMPONENT_REF)
2494 foo = TREE_OPERAND (foo, 0);
2495 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
2496 warning (OPT_Wextra, "subscripting array declared %<register%>");
2499 type = TREE_TYPE (TREE_TYPE (array));
2500 rval = build4 (ARRAY_REF, type, array, idx, NULL_TREE, NULL_TREE);
2501 /* Array ref is const/volatile if the array elements are
2502 or if the array is.. */
2503 TREE_READONLY (rval)
2504 |= (CP_TYPE_CONST_P (type) | TREE_READONLY (array));
2505 TREE_SIDE_EFFECTS (rval)
2506 |= (CP_TYPE_VOLATILE_P (type) | TREE_SIDE_EFFECTS (array));
2507 TREE_THIS_VOLATILE (rval)
2508 |= (CP_TYPE_VOLATILE_P (type) | TREE_THIS_VOLATILE (array));
2509 return require_complete_type (fold_if_not_in_template (rval));
2513 tree ar = default_conversion (array);
2514 tree ind = default_conversion (idx);
2516 /* Put the integer in IND to simplify error checking. */
2517 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
2524 if (ar == error_mark_node)
2527 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE)
2529 error ("subscripted value is neither array nor pointer");
2530 return error_mark_node;
2532 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
2534 error ("array subscript is not an integer");
2535 return error_mark_node;
2538 return build_indirect_ref (cp_build_binary_op (PLUS_EXPR, ar, ind),
2543 /* Resolve a pointer to member function. INSTANCE is the object
2544 instance to use, if the member points to a virtual member.
2546 This used to avoid checking for virtual functions if basetype
2547 has no virtual functions, according to an earlier ANSI draft.
2548 With the final ISO C++ rules, such an optimization is
2549 incorrect: A pointer to a derived member can be static_cast
2550 to pointer-to-base-member, as long as the dynamic object
2551 later has the right member. */
2554 get_member_function_from_ptrfunc (tree *instance_ptrptr, tree function)
2556 if (TREE_CODE (function) == OFFSET_REF)
2557 function = TREE_OPERAND (function, 1);
2559 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
2561 tree idx, delta, e1, e2, e3, vtbl, basetype;
2562 tree fntype = TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (function));
2564 tree instance_ptr = *instance_ptrptr;
2565 tree instance_save_expr = 0;
2566 if (instance_ptr == error_mark_node)
2568 if (TREE_CODE (function) == PTRMEM_CST)
2570 /* Extracting the function address from a pmf is only
2571 allowed with -Wno-pmf-conversions. It only works for
2573 e1 = build_addr_func (PTRMEM_CST_MEMBER (function));
2574 e1 = convert (fntype, e1);
2579 error ("object missing in use of %qE", function);
2580 return error_mark_node;
2584 if (TREE_SIDE_EFFECTS (instance_ptr))
2585 instance_ptr = instance_save_expr = save_expr (instance_ptr);
2587 if (TREE_SIDE_EFFECTS (function))
2588 function = save_expr (function);
2590 /* Start by extracting all the information from the PMF itself. */
2591 e3 = pfn_from_ptrmemfunc (function);
2592 delta = build_ptrmemfunc_access_expr (function, delta_identifier);
2593 idx = build1 (NOP_EXPR, vtable_index_type, e3);
2594 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
2596 case ptrmemfunc_vbit_in_pfn:
2597 e1 = cp_build_binary_op (BIT_AND_EXPR, idx, integer_one_node);
2598 idx = cp_build_binary_op (MINUS_EXPR, idx, integer_one_node);
2601 case ptrmemfunc_vbit_in_delta:
2602 e1 = cp_build_binary_op (BIT_AND_EXPR, delta, integer_one_node);
2603 delta = cp_build_binary_op (RSHIFT_EXPR, delta, integer_one_node);
2610 /* Convert down to the right base before using the instance. A
2611 special case is that in a pointer to member of class C, C may
2612 be incomplete. In that case, the function will of course be
2613 a member of C, and no conversion is required. In fact,
2614 lookup_base will fail in that case, because incomplete
2615 classes do not have BINFOs. */
2616 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (fntype));
2617 if (!same_type_ignoring_top_level_qualifiers_p
2618 (basetype, TREE_TYPE (TREE_TYPE (instance_ptr))))
2620 basetype = lookup_base (TREE_TYPE (TREE_TYPE (instance_ptr)),
2621 basetype, ba_check, NULL);
2622 instance_ptr = build_base_path (PLUS_EXPR, instance_ptr, basetype,
2624 if (instance_ptr == error_mark_node)
2625 return error_mark_node;
2627 /* ...and then the delta in the PMF. */
2628 instance_ptr = build2 (PLUS_EXPR, TREE_TYPE (instance_ptr),
2629 instance_ptr, delta);
2631 /* Hand back the adjusted 'this' argument to our caller. */
2632 *instance_ptrptr = instance_ptr;
2634 /* Next extract the vtable pointer from the object. */
2635 vtbl = build1 (NOP_EXPR, build_pointer_type (vtbl_ptr_type_node),
2637 vtbl = build_indirect_ref (vtbl, NULL);
2639 /* Finally, extract the function pointer from the vtable. */
2640 e2 = fold_build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, idx);
2641 e2 = build_indirect_ref (e2, NULL);
2642 TREE_CONSTANT (e2) = 1;
2643 TREE_INVARIANT (e2) = 1;
2645 /* When using function descriptors, the address of the
2646 vtable entry is treated as a function pointer. */
2647 if (TARGET_VTABLE_USES_DESCRIPTORS)
2648 e2 = build1 (NOP_EXPR, TREE_TYPE (e2),
2649 build_unary_op (ADDR_EXPR, e2, /*noconvert=*/1));
2651 TREE_TYPE (e2) = TREE_TYPE (e3);
2652 e1 = build_conditional_expr (e1, e2, e3);
2654 /* Make sure this doesn't get evaluated first inside one of the
2655 branches of the COND_EXPR. */
2656 if (instance_save_expr)
2657 e1 = build2 (COMPOUND_EXPR, TREE_TYPE (e1),
2658 instance_save_expr, e1);
2666 build_function_call (tree function, tree params)
2668 tree fntype, fndecl;
2669 tree coerced_params;
2670 tree name = NULL_TREE;
2672 tree original = function;
2674 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2675 expressions, like those used for ObjC messenger dispatches. */
2676 function = objc_rewrite_function_call (function, params);
2678 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2679 Strip such NOP_EXPRs, since FUNCTION is used in non-lvalue context. */
2680 if (TREE_CODE (function) == NOP_EXPR
2681 && TREE_TYPE (function) == TREE_TYPE (TREE_OPERAND (function, 0)))
2682 function = TREE_OPERAND (function, 0);
2684 if (TREE_CODE (function) == FUNCTION_DECL)
2686 name = DECL_NAME (function);
2688 mark_used (function);
2691 /* Convert anything with function type to a pointer-to-function. */
2692 if (pedantic && DECL_MAIN_P (function))
2693 pedwarn ("ISO C++ forbids calling %<::main%> from within program");
2695 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
2696 (because calling an inline function does not mean the function
2697 needs to be separately compiled). */
2699 if (DECL_INLINE (function))
2700 function = inline_conversion (function);
2702 function = build_addr_func (function);
2708 function = build_addr_func (function);
2711 if (function == error_mark_node)
2712 return error_mark_node;
2714 fntype = TREE_TYPE (function);
2716 if (TYPE_PTRMEMFUNC_P (fntype))
2718 error ("must use %<.*%> or %<->*%> to call pointer-to-member "
2719 "function in %<%E (...)%>",
2721 return error_mark_node;
2724 is_method = (TREE_CODE (fntype) == POINTER_TYPE
2725 && TREE_CODE (TREE_TYPE (fntype)) == METHOD_TYPE);
2727 if (!((TREE_CODE (fntype) == POINTER_TYPE
2728 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)
2730 || TREE_CODE (function) == TEMPLATE_ID_EXPR))
2732 error ("%qE cannot be used as a function", original);
2733 return error_mark_node;
2736 /* fntype now gets the type of function pointed to. */
2737 fntype = TREE_TYPE (fntype);
2739 /* Convert the parameters to the types declared in the
2740 function prototype, or apply default promotions. */
2742 coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype),
2743 params, fndecl, LOOKUP_NORMAL);
2744 if (coerced_params == error_mark_node)
2745 return error_mark_node;
2747 /* Check for errors in format strings and inappropriately
2750 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2751 TYPE_ARG_TYPES (fntype));
2753 return build_cxx_call (function, coerced_params);
2756 /* Convert the actual parameter expressions in the list VALUES
2757 to the types in the list TYPELIST.
2758 If parmdecls is exhausted, or when an element has NULL as its type,
2759 perform the default conversions.
2761 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
2763 This is also where warnings about wrong number of args are generated.
2765 Return a list of expressions for the parameters as converted.
2767 Both VALUES and the returned value are chains of TREE_LIST nodes
2768 with the elements of the list in the TREE_VALUE slots of those nodes.
2770 In C++, unspecified trailing parameters can be filled in with their
2771 default arguments, if such were specified. Do so here. */
2774 convert_arguments (tree typelist, tree values, tree fndecl, int flags)
2776 tree typetail, valtail;
2777 tree result = NULL_TREE;
2778 const char *called_thing = 0;
2781 /* Argument passing is always copy-initialization. */
2782 flags |= LOOKUP_ONLYCONVERTING;
2786 if (TREE_CODE (TREE_TYPE (fndecl)) == METHOD_TYPE)
2788 if (DECL_NAME (fndecl) == NULL_TREE
2789 || IDENTIFIER_HAS_TYPE_VALUE (DECL_NAME (fndecl)))
2790 called_thing = "constructor";
2792 called_thing = "member function";
2795 called_thing = "function";
2798 for (valtail = values, typetail = typelist;
2800 valtail = TREE_CHAIN (valtail), i++)
2802 tree type = typetail ? TREE_VALUE (typetail) : 0;
2803 tree val = TREE_VALUE (valtail);
2805 if (val == error_mark_node || type == error_mark_node)
2806 return error_mark_node;
2808 if (type == void_type_node)
2812 error ("too many arguments to %s %q+#D", called_thing, fndecl);
2813 error ("at this point in file");
2816 error ("too many arguments to function");
2817 /* In case anybody wants to know if this argument
2820 TREE_TYPE (tree_last (result)) = error_mark_node;
2824 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
2825 Strip such NOP_EXPRs, since VAL is used in non-lvalue context. */
2826 if (TREE_CODE (val) == NOP_EXPR
2827 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))
2828 && (type == 0 || TREE_CODE (type) != REFERENCE_TYPE))
2829 val = TREE_OPERAND (val, 0);
2831 if (type == 0 || TREE_CODE (type) != REFERENCE_TYPE)
2833 if (TREE_CODE (TREE_TYPE (val)) == ARRAY_TYPE
2834 || TREE_CODE (TREE_TYPE (val)) == FUNCTION_TYPE
2835 || TREE_CODE (TREE_TYPE (val)) == METHOD_TYPE)
2836 val = decay_conversion (val);
2839 if (val == error_mark_node)
2840 return error_mark_node;
2844 /* Formal parm type is specified by a function prototype. */
2847 if (!COMPLETE_TYPE_P (complete_type (type)))
2850 error ("parameter %P of %qD has incomplete type %qT",
2853 error ("parameter %P has incomplete type %qT", i, type);
2854 parmval = error_mark_node;
2858 parmval = convert_for_initialization
2859 (NULL_TREE, type, val, flags,
2860 "argument passing", fndecl, i);
2861 parmval = convert_for_arg_passing (type, parmval);
2864 if (parmval == error_mark_node)
2865 return error_mark_node;
2867 result = tree_cons (NULL_TREE, parmval, result);
2871 if (fndecl && DECL_BUILT_IN (fndecl)
2872 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_CONSTANT_P)
2873 /* Don't do ellipsis conversion for __built_in_constant_p
2874 as this will result in spurious warnings for non-POD
2876 val = require_complete_type (val);
2878 val = convert_arg_to_ellipsis (val);
2880 result = tree_cons (NULL_TREE, val, result);
2884 typetail = TREE_CHAIN (typetail);
2887 if (typetail != 0 && typetail != void_list_node)
2889 /* See if there are default arguments that can be used. */
2890 if (TREE_PURPOSE (typetail)
2891 && TREE_CODE (TREE_PURPOSE (typetail)) != DEFAULT_ARG)
2893 for (; typetail != void_list_node; ++i)
2896 = convert_default_arg (TREE_VALUE (typetail),
2897 TREE_PURPOSE (typetail),
2900 if (parmval == error_mark_node)
2901 return error_mark_node;
2903 result = tree_cons (0, parmval, result);
2904 typetail = TREE_CHAIN (typetail);
2905 /* ends with `...'. */
2906 if (typetail == NULL_TREE)
2914 error ("too few arguments to %s %q+#D", called_thing, fndecl);
2915 error ("at this point in file");
2918 error ("too few arguments to function");
2919 return error_mark_node;
2923 return nreverse (result);
2926 /* Build a binary-operation expression, after performing default
2927 conversions on the operands. CODE is the kind of expression to build. */
2930 build_x_binary_op (enum tree_code code, tree arg1, enum tree_code arg1_code,
2931 tree arg2, enum tree_code arg2_code, bool *overloaded_p)
2940 if (processing_template_decl)
2942 if (type_dependent_expression_p (arg1)
2943 || type_dependent_expression_p (arg2))
2944 return build_min_nt (code, arg1, arg2);
2945 arg1 = build_non_dependent_expr (arg1);
2946 arg2 = build_non_dependent_expr (arg2);
2949 if (code == DOTSTAR_EXPR)
2950 expr = build_m_component_ref (arg1, arg2);
2952 expr = build_new_op (code, LOOKUP_NORMAL, arg1, arg2, NULL_TREE,
2955 /* Check for cases such as x+y<<z which users are likely to
2956 misinterpret. But don't warn about obj << x + y, since that is a
2957 common idiom for I/O. */
2958 if (warn_parentheses
2959 && !processing_template_decl
2960 && !error_operand_p (arg1)
2961 && !error_operand_p (arg2)
2962 && (code != LSHIFT_EXPR
2963 || !IS_AGGR_TYPE (TREE_TYPE (arg1))))
2964 warn_about_parentheses (code, arg1_code, arg2_code);
2966 if (processing_template_decl && expr != error_mark_node)
2967 return build_min_non_dep (code, expr, orig_arg1, orig_arg2);
2972 /* Build a binary-operation expression without default conversions.
2973 CODE is the kind of expression to build.
2974 This function differs from `build' in several ways:
2975 the data type of the result is computed and recorded in it,
2976 warnings are generated if arg data types are invalid,
2977 special handling for addition and subtraction of pointers is known,
2978 and some optimization is done (operations on narrow ints
2979 are done in the narrower type when that gives the same result).
2980 Constant folding is also done before the result is returned.
2982 Note that the operands will never have enumeral types
2983 because either they have just had the default conversions performed
2984 or they have both just been converted to some other type in which
2985 the arithmetic is to be done.
2987 C++: must do special pointer arithmetic when implementing
2988 multiple inheritance, and deal with pointer to member functions. */
2991 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
2992 int convert_p ATTRIBUTE_UNUSED)
2995 enum tree_code code0, code1;
2997 const char *invalid_op_diag;
2999 /* Expression code to give to the expression when it is built.
3000 Normally this is CODE, which is what the caller asked for,
3001 but in some special cases we change it. */
3002 enum tree_code resultcode = code;
3004 /* Data type in which the computation is to be performed.
3005 In the simplest cases this is the common type of the arguments. */
3006 tree result_type = NULL;
3008 /* Nonzero means operands have already been type-converted
3009 in whatever way is necessary.
3010 Zero means they need to be converted to RESULT_TYPE. */
3013 /* Nonzero means create the expression with this type, rather than
3015 tree build_type = 0;
3017 /* Nonzero means after finally constructing the expression
3018 convert it to this type. */
3019 tree final_type = 0;
3023 /* Nonzero if this is an operation like MIN or MAX which can
3024 safely be computed in short if both args are promoted shorts.
3025 Also implies COMMON.
3026 -1 indicates a bitwise operation; this makes a difference
3027 in the exact conditions for when it is safe to do the operation
3028 in a narrower mode. */
3031 /* Nonzero if this is a comparison operation;
3032 if both args are promoted shorts, compare the original shorts.
3033 Also implies COMMON. */
3034 int short_compare = 0;
3036 /* Nonzero if this is a right-shift operation, which can be computed on the
3037 original short and then promoted if the operand is a promoted short. */
3038 int short_shift = 0;
3040 /* Nonzero means set RESULT_TYPE to the common type of the args. */
3043 /* True if both operands have arithmetic type. */
3044 bool arithmetic_types_p;
3046 /* Apply default conversions. */
3050 if (code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
3051 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
3052 || code == TRUTH_XOR_EXPR)
3054 if (!really_overloaded_fn (op0))
3055 op0 = decay_conversion (op0);
3056 if (!really_overloaded_fn (op1))
3057 op1 = decay_conversion (op1);
3061 if (!really_overloaded_fn (op0))
3062 op0 = default_conversion (op0);
3063 if (!really_overloaded_fn (op1))
3064 op1 = default_conversion (op1);
3067 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
3068 STRIP_TYPE_NOPS (op0);
3069 STRIP_TYPE_NOPS (op1);
3071 /* DTRT if one side is an overloaded function, but complain about it. */
3072 if (type_unknown_p (op0))
3074 tree t = instantiate_type (TREE_TYPE (op1), op0, tf_none);
3075 if (t != error_mark_node)
3077 pedwarn ("assuming cast to type %qT from overloaded function",
3082 if (type_unknown_p (op1))
3084 tree t = instantiate_type (TREE_TYPE (op0), op1, tf_none);
3085 if (t != error_mark_node)
3087 pedwarn ("assuming cast to type %qT from overloaded function",
3093 type0 = TREE_TYPE (op0);
3094 type1 = TREE_TYPE (op1);
3096 /* The expression codes of the data types of the arguments tell us
3097 whether the arguments are integers, floating, pointers, etc. */
3098 code0 = TREE_CODE (type0);
3099 code1 = TREE_CODE (type1);
3101 /* If an error was already reported for one of the arguments,
3102 avoid reporting another error. */
3104 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
3105 return error_mark_node;
3107 if ((invalid_op_diag
3108 = targetm.invalid_binary_op (code, type0, type1)))
3110 error (invalid_op_diag, "");
3111 return error_mark_node;
3117 /* Subtraction of two similar pointers.
3118 We must subtract them as integers, then divide by object size. */
3119 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
3120 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type0),
3122 return pointer_diff (op0, op1, common_type (type0, type1));
3123 /* In all other cases except pointer - int, the usual arithmetic
3125 else if (!(code0 == POINTER_TYPE && code1 == INTEGER_TYPE))
3130 /* The pointer - int case is just like pointer + int; fall
3133 if ((code0 == POINTER_TYPE || code1 == POINTER_TYPE)
3134 && (code0 == INTEGER_TYPE || code1 == INTEGER_TYPE))
3138 ptr_operand = ((code0 == POINTER_TYPE) ? op0 : op1);
3139 int_operand = ((code0 == INTEGER_TYPE) ? op0 : op1);
3140 if (processing_template_decl)
3142 result_type = TREE_TYPE (ptr_operand);
3145 return cp_pointer_int_sum (code,
3156 case TRUNC_DIV_EXPR:
3158 case FLOOR_DIV_EXPR:
3159 case ROUND_DIV_EXPR:
3160 case EXACT_DIV_EXPR:
3161 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3162 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
3163 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3164 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
3166 enum tree_code tcode0 = code0, tcode1 = code1;
3168 if (TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1))
3169 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0%>", op0);
3170 else if (TREE_CODE (op1) == REAL_CST && real_zerop (op1))
3171 warning (OPT_Wdiv_by_zero, "division by zero in %<%E / 0.%>", op0);
3173 if (tcode0 == COMPLEX_TYPE || tcode0 == VECTOR_TYPE)
3174 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
3175 if (tcode1 == COMPLEX_TYPE || tcode1 == VECTOR_TYPE)
3176 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
3178 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
3179 resultcode = RDIV_EXPR;
3181 /* When dividing two signed integers, we have to promote to int.
3182 unless we divide by a constant != -1. Note that default
3183 conversion will have been performed on the operands at this
3184 point, so we have to dig out the original type to find out if
3186 shorten = ((TREE_CODE (op0) == NOP_EXPR
3187 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3188 || (TREE_CODE (op1) == INTEGER_CST
3189 && ! integer_all_onesp (op1)));
3198 if ((code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3199 || (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE))
3203 case TRUNC_MOD_EXPR:
3204 case FLOOR_MOD_EXPR:
3205 if (code1 == INTEGER_TYPE && integer_zerop (op1))
3206 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0%>", op0);
3207 else if (code1 == REAL_TYPE && real_zerop (op1))
3208 warning (OPT_Wdiv_by_zero, "division by zero in %<%E %% 0.%>", op0);
3210 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3212 /* Although it would be tempting to shorten always here, that loses
3213 on some targets, since the modulo instruction is undefined if the
3214 quotient can't be represented in the computation mode. We shorten
3215 only if unsigned or if dividing by something we know != -1. */
3216 shorten = ((TREE_CODE (op0) == NOP_EXPR
3217 && TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op0, 0))))
3218 || (TREE_CODE (op1) == INTEGER_CST
3219 && ! integer_all_onesp (op1)));
3224 case TRUTH_ANDIF_EXPR:
3225 case TRUTH_ORIF_EXPR:
3226 case TRUTH_AND_EXPR:
3228 result_type = boolean_type_node;
3231 /* Shift operations: result has same type as first operand;
3232 always convert second operand to int.
3233 Also set SHORT_SHIFT if shifting rightward. */
3236 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3238 result_type = type0;
3239 if (TREE_CODE (op1) == INTEGER_CST)
3241 if (tree_int_cst_lt (op1, integer_zero_node))
3242 warning (0, "right shift count is negative");
3245 if (! integer_zerop (op1))
3247 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3248 warning (0, "right shift count >= width of type");
3251 /* Convert the shift-count to an integer, regardless of
3252 size of value being shifted. */
3253 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3254 op1 = cp_convert (integer_type_node, op1);
3255 /* Avoid converting op1 to result_type later. */
3261 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3263 result_type = type0;
3264 if (TREE_CODE (op1) == INTEGER_CST)
3266 if (tree_int_cst_lt (op1, integer_zero_node))
3267 warning (0, "left shift count is negative");
3268 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3269 warning (0, "left shift count >= width of type");
3271 /* Convert the shift-count to an integer, regardless of
3272 size of value being shifted. */
3273 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3274 op1 = cp_convert (integer_type_node, op1);
3275 /* Avoid converting op1 to result_type later. */
3282 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
3284 result_type = type0;
3285 if (TREE_CODE (op1) == INTEGER_CST)
3287 if (tree_int_cst_lt (op1, integer_zero_node))
3288 warning (0, "%s rotate count is negative",
3289 (code == LROTATE_EXPR) ? "left" : "right");
3290 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
3291 warning (0, "%s rotate count >= width of type",
3292 (code == LROTATE_EXPR) ? "left" : "right");
3294 /* Convert the shift-count to an integer, regardless of
3295 size of value being shifted. */
3296 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
3297 op1 = cp_convert (integer_type_node, op1);
3303 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
3304 warning (OPT_Wfloat_equal,
3305 "comparing floating point with == or != is unsafe");
3306 if ((TREE_CODE (orig_op0) == STRING_CST && !integer_zerop (op1))
3307 || (TREE_CODE (orig_op1) == STRING_CST && !integer_zerop (op0)))
3308 warning (OPT_Waddress,
3309 "comparison with string literal results in unspecified behaviour");
3311 build_type = boolean_type_node;
3312 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
3313 || code0 == COMPLEX_TYPE)
3314 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3315 || code1 == COMPLEX_TYPE))
3317 else if ((code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3318 || (TYPE_PTRMEM_P (type0) && TYPE_PTRMEM_P (type1)))
3319 result_type = composite_pointer_type (type0, type1, op0, op1,
3321 else if ((code0 == POINTER_TYPE || TYPE_PTRMEM_P (type0))
3322 && null_ptr_cst_p (op1))
3323 result_type = type0;
3324 else if ((code1 == POINTER_TYPE || TYPE_PTRMEM_P (type1))
3325 && null_ptr_cst_p (op0))
3326 result_type = type1;
3327 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3329 result_type = type0;
3330 error ("ISO C++ forbids comparison between pointer and integer");
3332 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3334 result_type = type1;
3335 error ("ISO C++ forbids comparison between pointer and integer");
3337 else if (TYPE_PTRMEMFUNC_P (type0) && null_ptr_cst_p (op1))
3339 op0 = build_ptrmemfunc_access_expr (op0, pfn_identifier);
3340 op1 = cp_convert (TREE_TYPE (op0), integer_zero_node);
3341 result_type = TREE_TYPE (op0);
3343 else if (TYPE_PTRMEMFUNC_P (type1) && null_ptr_cst_p (op0))
3344 return cp_build_binary_op (code, op1, op0);
3345 else if (TYPE_PTRMEMFUNC_P (type0) && TYPE_PTRMEMFUNC_P (type1)
3346 && same_type_p (type0, type1))
3348 /* E will be the final comparison. */
3350 /* E1 and E2 are for scratch. */
3358 if (TREE_SIDE_EFFECTS (op0))
3359 op0 = save_expr (op0);
3360 if (TREE_SIDE_EFFECTS (op1))
3361 op1 = save_expr (op1);
3366 && (!op0.pfn || op0.delta == op1.delta))
3368 The reason for the `!op0.pfn' bit is that a NULL
3369 pointer-to-member is any member with a zero PFN; the
3370 DELTA field is unspecified. */
3371 pfn0 = pfn_from_ptrmemfunc (op0);
3372 pfn1 = pfn_from_ptrmemfunc (op1);
3373 delta0 = build_ptrmemfunc_access_expr (op0,
3375 delta1 = build_ptrmemfunc_access_expr (op1,
3377 e1 = cp_build_binary_op (EQ_EXPR, delta0, delta1);
3378 e2 = cp_build_binary_op (EQ_EXPR,
3380 cp_convert (TREE_TYPE (pfn0),
3381 integer_zero_node));
3382 e1 = cp_build_binary_op (TRUTH_ORIF_EXPR, e1, e2);
3383 e2 = build2 (EQ_EXPR, boolean_type_node, pfn0, pfn1);
3384 e = cp_build_binary_op (TRUTH_ANDIF_EXPR, e2, e1);
3385 if (code == EQ_EXPR)
3387 return cp_build_binary_op (EQ_EXPR, e, integer_zero_node);
3391 gcc_assert (!TYPE_PTRMEMFUNC_P (type0)
3392 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type0),
3394 gcc_assert (!TYPE_PTRMEMFUNC_P (type1)
3395 || !same_type_p (TYPE_PTRMEMFUNC_FN_TYPE (type1),
3403 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3404 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3406 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3407 result_type = composite_pointer_type (type0, type1, op0, op1,
3415 if (TREE_CODE (orig_op0) == STRING_CST
3416 || TREE_CODE (orig_op1) == STRING_CST)
3417 warning (OPT_Waddress,
3418 "comparison with string literal results in unspecified behaviour");
3420 build_type = boolean_type_node;
3421 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
3422 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
3424 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
3425 result_type = composite_pointer_type (type0, type1, op0, op1,
3427 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
3428 && integer_zerop (op1))
3429 result_type = type0;
3430 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
3431 && integer_zerop (op0))
3432 result_type = type1;
3433 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
3435 result_type = type0;
3436 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3438 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
3440 result_type = type1;
3441 pedwarn ("ISO C++ forbids comparison between pointer and integer");
3445 case UNORDERED_EXPR:
3452 build_type = integer_type_node;
3453 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
3455 error ("unordered comparison on non-floating point argument");
3456 return error_mark_node;
3465 if (((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
3466 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
3467 || code1 == COMPLEX_TYPE)))
3468 arithmetic_types_p = 1;
3471 arithmetic_types_p = 0;
3472 /* Vector arithmetic is only allowed when both sides are vectors. */
3473 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
3475 if (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
3476 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
3479 binary_op_error (code, type0, type1);
3480 return error_mark_node;
3482 arithmetic_types_p = 1;
3485 /* Determine the RESULT_TYPE, if it is not already known. */
3487 && arithmetic_types_p
3488 && (shorten || common || short_compare))
3489 result_type = common_type (type0, type1);
3493 error ("invalid operands of types %qT and %qT to binary %qO",
3494 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1), code);
3495 return error_mark_node;
3498 /* If we're in a template, the only thing we need to know is the
3500 if (processing_template_decl)
3501 return build2 (resultcode,
3502 build_type ? build_type : result_type,
3505 if (arithmetic_types_p)
3507 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
3509 /* For certain operations (which identify themselves by shorten != 0)
3510 if both args were extended from the same smaller type,
3511 do the arithmetic in that type and then extend.
3513 shorten !=0 and !=1 indicates a bitwise operation.
3514 For them, this optimization is safe only if
3515 both args are zero-extended or both are sign-extended.
3516 Otherwise, we might change the result.
3517 Eg, (short)-1 | (unsigned short)-1 is (int)-1
3518 but calculated in (unsigned short) it would be (unsigned short)-1. */
3520 if (shorten && none_complex)
3522 int unsigned0, unsigned1;
3523 tree arg0 = get_narrower (op0, &unsigned0);
3524 tree arg1 = get_narrower (op1, &unsigned1);
3525 /* UNS is 1 if the operation to be done is an unsigned one. */
3526 int uns = TYPE_UNSIGNED (result_type);
3529 final_type = result_type;
3531 /* Handle the case that OP0 does not *contain* a conversion
3532 but it *requires* conversion to FINAL_TYPE. */
3534 if (op0 == arg0 && TREE_TYPE (op0) != final_type)
3535 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
3536 if (op1 == arg1 && TREE_TYPE (op1) != final_type)
3537 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
3539 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
3541 /* For bitwise operations, signedness of nominal type
3542 does not matter. Consider only how operands were extended. */
3546 /* Note that in all three cases below we refrain from optimizing
3547 an unsigned operation on sign-extended args.
3548 That would not be valid. */
3550 /* Both args variable: if both extended in same way
3551 from same width, do it in that width.
3552 Do it unsigned if args were zero-extended. */
3553 if ((TYPE_PRECISION (TREE_TYPE (arg0))
3554 < TYPE_PRECISION (result_type))
3555 && (TYPE_PRECISION (TREE_TYPE (arg1))
3556 == TYPE_PRECISION (TREE_TYPE (arg0)))
3557 && unsigned0 == unsigned1
3558 && (unsigned0 || !uns))
3559 result_type = c_common_signed_or_unsigned_type
3560 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
3561 else if (TREE_CODE (arg0) == INTEGER_CST
3562 && (unsigned1 || !uns)
3563 && (TYPE_PRECISION (TREE_TYPE (arg1))
3564 < TYPE_PRECISION (result_type))
3565 && (type = c_common_signed_or_unsigned_type
3566 (unsigned1, TREE_TYPE (arg1)),
3567 int_fits_type_p (arg0, type)))
3569 else if (TREE_CODE (arg1) == INTEGER_CST
3570 && (unsigned0 || !uns)
3571 && (TYPE_PRECISION (TREE_TYPE (arg0))
3572 < TYPE_PRECISION (result_type))
3573 && (type = c_common_signed_or_unsigned_type
3574 (unsigned0, TREE_TYPE (arg0)),
3575 int_fits_type_p (arg1, type)))
3579 /* Shifts can be shortened if shifting right. */
3584 tree arg0 = get_narrower (op0, &unsigned_arg);
3586 final_type = result_type;
3588 if (arg0 == op0 && final_type == TREE_TYPE (op0))
3589 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
3591 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
3592 /* We can shorten only if the shift count is less than the
3593 number of bits in the smaller type size. */
3594 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
3595 /* If arg is sign-extended and then unsigned-shifted,
3596 we can simulate this with a signed shift in arg's type
3597 only if the extended result is at least twice as wide
3598 as the arg. Otherwise, the shift could use up all the
3599 ones made by sign-extension and bring in zeros.
3600 We can't optimize that case at all, but in most machines
3601 it never happens because available widths are 2**N. */
3602 && (!TYPE_UNSIGNED (final_type)
3604 || (((unsigned) 2 * TYPE_PRECISION (TREE_TYPE (arg0)))
3605 <= TYPE_PRECISION (result_type))))
3607 /* Do an unsigned shift if the operand was zero-extended. */
3609 = c_common_signed_or_unsigned_type (unsigned_arg,
3611 /* Convert value-to-be-shifted to that type. */
3612 if (TREE_TYPE (op0) != result_type)
3613 op0 = cp_convert (result_type, op0);
3618 /* Comparison operations are shortened too but differently.
3619 They identify themselves by setting short_compare = 1. */
3623 /* Don't write &op0, etc., because that would prevent op0
3624 from being kept in a register.
3625 Instead, make copies of the our local variables and
3626 pass the copies by reference, then copy them back afterward. */
3627 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
3628 enum tree_code xresultcode = resultcode;
3630 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
3632 return cp_convert (boolean_type_node, val);
3633 op0 = xop0, op1 = xop1;
3635 resultcode = xresultcode;
3638 if ((short_compare || code == MIN_EXPR || code == MAX_EXPR)
3639 && warn_sign_compare
3640 /* Do not warn until the template is instantiated; we cannot
3641 bound the ranges of the arguments until that point. */
3642 && !processing_template_decl)
3644 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
3645 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3647 int unsignedp0, unsignedp1;
3648 tree primop0 = get_narrower (op0, &unsignedp0);
3649 tree primop1 = get_narrower (op1, &unsignedp1);
3651 /* Check for comparison of different enum types. */
3652 if (TREE_CODE (TREE_TYPE (orig_op0)) == ENUMERAL_TYPE
3653 && TREE_CODE (TREE_TYPE (orig_op1)) == ENUMERAL_TYPE
3654 && TYPE_MAIN_VARIANT (TREE_TYPE (orig_op0))
3655 != TYPE_MAIN_VARIANT (TREE_TYPE (orig_op1)))
3657 warning (0, "comparison between types %q#T and %q#T",
3658 TREE_TYPE (orig_op0), TREE_TYPE (orig_op1));
3661 /* Give warnings for comparisons between signed and unsigned
3662 quantities that may fail. */
3663 /* Do the checking based on the original operand trees, so that
3664 casts will be considered, but default promotions won't be. */
3666 /* Do not warn if the comparison is being done in a signed type,
3667 since the signed type will only be chosen if it can represent
3668 all the values of the unsigned type. */
3669 if (!TYPE_UNSIGNED (result_type))
3671 /* Do not warn if both operands are unsigned. */
3672 else if (op0_signed == op1_signed)
3674 /* Do not warn if the signed quantity is an unsuffixed
3675 integer literal (or some static constant expression
3676 involving such literals or a conditional expression
3677 involving such literals) and it is non-negative. */
3678 else if ((op0_signed && tree_expr_nonnegative_p (orig_op0))
3679 || (op1_signed && tree_expr_nonnegative_p (orig_op1)))
3681 /* Do not warn if the comparison is an equality operation,
3682 the unsigned quantity is an integral constant and it does
3683 not use the most significant bit of result_type. */
3684 else if ((resultcode == EQ_EXPR || resultcode == NE_EXPR)
3685 && ((op0_signed && TREE_CODE (orig_op1) == INTEGER_CST
3686 && int_fits_type_p (orig_op1, c_common_signed_type
3688 || (op1_signed && TREE_CODE (orig_op0) == INTEGER_CST
3689 && int_fits_type_p (orig_op0, c_common_signed_type
3693 warning (0, "comparison between signed and unsigned integer expressions");
3695 /* Warn if two unsigned values are being compared in a size
3696 larger than their original size, and one (and only one) is the
3697 result of a `~' operator. This comparison will always fail.
3699 Also warn if one operand is a constant, and the constant does not
3700 have all bits set that are set in the ~ operand when it is
3703 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
3704 ^ (TREE_CODE (primop1) == BIT_NOT_EXPR))
3706 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
3707 primop0 = get_narrower (TREE_OPERAND (op0, 0), &unsignedp0);
3708 if (TREE_CODE (primop1) == BIT_NOT_EXPR)
3709 primop1 = get_narrower (TREE_OPERAND (op1, 0), &unsignedp1);
3711 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
3714 HOST_WIDE_INT constant, mask;
3718 if (host_integerp (primop0, 0))
3721 unsignedp = unsignedp1;
3722 constant = tree_low_cst (primop0, 0);
3727 unsignedp = unsignedp0;
3728 constant = tree_low_cst (primop1, 0);
3731 bits = TYPE_PRECISION (TREE_TYPE (primop));
3732 if (bits < TYPE_PRECISION (result_type)
3733 && bits < HOST_BITS_PER_LONG && unsignedp)
3735 mask = (~ (HOST_WIDE_INT) 0) << bits;
3736 if ((mask & constant) != mask)
3737 warning (0, "comparison of promoted ~unsigned with constant");
3740 else if (unsignedp0 && unsignedp1
3741 && (TYPE_PRECISION (TREE_TYPE (primop0))
3742 < TYPE_PRECISION (result_type))
3743 && (TYPE_PRECISION (TREE_TYPE (primop1))
3744 < TYPE_PRECISION (result_type)))
3745 warning (0, "comparison of promoted ~unsigned with unsigned");
3750 /* If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
3751 Then the expression will be built.
3752 It will be given type FINAL_TYPE if that is nonzero;
3753 otherwise, it will be given type RESULT_TYPE. */
3755 /* Issue warnings about peculiar, but valid, uses of NULL. */
3756 if (/* It's reasonable to use pointer values as operands of &&
3757 and ||, so NULL is no exception. */
3758 !(code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
3759 && (/* If OP0 is NULL and OP1 is not a pointer, or vice versa. */
3760 (orig_op0 == null_node
3761 && TREE_CODE (TREE_TYPE (op1)) != POINTER_TYPE)
3762 /* Or vice versa. */
3763 || (orig_op1 == null_node
3764 && TREE_CODE (TREE_TYPE (op0)) != POINTER_TYPE)
3765 /* Or, both are NULL and the operation was not a comparison. */
3766 || (orig_op0 == null_node && orig_op1 == null_node
3767 && code != EQ_EXPR && code != NE_EXPR)))
3768 /* Some sort of arithmetic operation involving NULL was
3769 performed. Note that pointer-difference and pointer-addition
3770 have already been handled above, and so we don't end up here in
3772 warning (0, "NULL used in arithmetic");
3776 if (TREE_TYPE (op0) != result_type)
3777 op0 = cp_convert (result_type, op0);
3778 if (TREE_TYPE (op1) != result_type)
3779 op1 = cp_convert (result_type, op1);
3781 if (op0 == error_mark_node || op1 == error_mark_node)
3782 return error_mark_node;
3785 if (build_type == NULL_TREE)
3786 build_type = result_type;
3788 result = build2 (resultcode, build_type, op0, op1);
3789 result = fold_if_not_in_template (result);
3790 if (final_type != 0)
3791 result = cp_convert (final_type, result);
3793 if (TREE_OVERFLOW_P (result)
3794 && !TREE_OVERFLOW_P (op0)
3795 && !TREE_OVERFLOW_P (op1))
3796 overflow_warning (result);
3801 /* Return a tree for the sum or difference (RESULTCODE says which)
3802 of pointer PTROP and integer INTOP. */
3805 cp_pointer_int_sum (enum tree_code resultcode, tree ptrop, tree intop)
3807 tree res_type = TREE_TYPE (ptrop);
3809 /* pointer_int_sum() uses size_in_bytes() on the TREE_TYPE(res_type)
3810 in certain circumstance (when it's valid to do so). So we need
3811 to make sure it's complete. We don't need to check here, if we
3812 can actually complete it at all, as those checks will be done in
3813 pointer_int_sum() anyway. */
3814 complete_type (TREE_TYPE (res_type));
3816 return pointer_int_sum (resultcode, ptrop,
3817 fold_if_not_in_template (intop));
3820 /* Return a tree for the difference of pointers OP0 and OP1.
3821 The resulting tree has type int. */
3824 pointer_diff (tree op0, tree op1, tree ptrtype)
3827 tree restype = ptrdiff_type_node;
3828 tree target_type = TREE_TYPE (ptrtype);
3830 if (!complete_type_or_else (target_type, NULL_TREE))
3831 return error_mark_node;
3833 if (pedantic || warn_pointer_arith)
3835 if (TREE_CODE (target_type) == VOID_TYPE)
3836 pedwarn ("ISO C++ forbids using pointer of type %<void *%> in subtraction");
3837 if (TREE_CODE (target_type) == FUNCTION_TYPE)
3838 pedwarn ("ISO C++ forbids using pointer to a function in subtraction");
3839 if (TREE_CODE (target_type) == METHOD_TYPE)
3840 pedwarn ("ISO C++ forbids using pointer to a method in subtraction");
3843 /* First do the subtraction as integers;
3844 then drop through to build the divide operator. */
3846 op0 = cp_build_binary_op (MINUS_EXPR,
3847 cp_convert (restype, op0),
3848 cp_convert (restype, op1));
3850 /* This generates an error if op1 is a pointer to an incomplete type. */
3851 if (!COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (op1))))
3852 error ("invalid use of a pointer to an incomplete type in pointer arithmetic");
3854 op1 = (TYPE_PTROB_P (ptrtype)
3855 ? size_in_bytes (target_type)
3856 : integer_one_node);
3858 /* Do the division. */
3860 result = build2 (EXACT_DIV_EXPR, restype, op0, cp_convert (restype, op1));
3861 return fold_if_not_in_template (result);
3864 /* Construct and perhaps optimize a tree representation
3865 for a unary operation. CODE, a tree_code, specifies the operation
3866 and XARG is the operand. */
3869 build_x_unary_op (enum tree_code code, tree xarg)
3871 tree orig_expr = xarg;
3875 if (processing_template_decl)
3877 if (type_dependent_expression_p (xarg))
3878 return build_min_nt (code, xarg, NULL_TREE);
3880 xarg = build_non_dependent_expr (xarg);
3885 /* [expr.unary.op] says:
3887 The address of an object of incomplete type can be taken.
3889 (And is just the ordinary address operator, not an overloaded
3890 "operator &".) However, if the type is a template
3891 specialization, we must complete the type at this point so that
3892 an overloaded "operator &" will be available if required. */
3893 if (code == ADDR_EXPR
3894 && TREE_CODE (xarg) != TEMPLATE_ID_EXPR
3895 && ((CLASS_TYPE_P (TREE_TYPE (xarg))
3896 && !COMPLETE_TYPE_P (complete_type (TREE_TYPE (xarg))))
3897 || (TREE_CODE (xarg) == OFFSET_REF)))
3898 /* Don't look for a function. */;
3900 exp = build_new_op (code, LOOKUP_NORMAL, xarg, NULL_TREE, NULL_TREE,
3901 /*overloaded_p=*/NULL);
3902 if (!exp && code == ADDR_EXPR)
3904 /* A pointer to member-function can be formed only by saying
3906 if (!flag_ms_extensions && TREE_CODE (TREE_TYPE (xarg)) == METHOD_TYPE
3907 && (TREE_CODE (xarg) != OFFSET_REF || !PTRMEM_OK_P (xarg)))
3909 if (TREE_CODE (xarg) != OFFSET_REF
3910 || !TYPE_P (TREE_OPERAND (xarg, 0)))
3912 error ("invalid use of %qE to form a pointer-to-member-function",
3914 if (TREE_CODE (xarg) != OFFSET_REF)
3915 inform (" a qualified-id is required");
3916 return error_mark_node;
3920 error ("parentheses around %qE cannot be used to form a"
3921 " pointer-to-member-function",
3923 PTRMEM_OK_P (xarg) = 1;
3927 if (TREE_CODE (xarg) == OFFSET_REF)
3929 ptrmem = PTRMEM_OK_P (xarg);
3931 if (!ptrmem && !flag_ms_extensions
3932 && TREE_CODE (TREE_TYPE (TREE_OPERAND (xarg, 1))) == METHOD_TYPE)
3934 /* A single non-static member, make sure we don't allow a
3935 pointer-to-member. */
3936 xarg = build2 (OFFSET_REF, TREE_TYPE (xarg),
3937 TREE_OPERAND (xarg, 0),
3938 ovl_cons (TREE_OPERAND (xarg, 1), NULL_TREE));
3939 PTRMEM_OK_P (xarg) = ptrmem;
3942 else if (TREE_CODE (xarg) == TARGET_EXPR)
3943 warning (0, "taking address of temporary");
3944 exp = build_unary_op (ADDR_EXPR, xarg, 0);
3947 if (processing_template_decl && exp != error_mark_node)
3948 exp = build_min_non_dep (code, exp, orig_expr,
3949 /*For {PRE,POST}{INC,DEC}REMENT_EXPR*/NULL_TREE);
3950 if (TREE_CODE (exp) == ADDR_EXPR)
3951 PTRMEM_OK_P (exp) = ptrmem;
3955 /* Like c_common_truthvalue_conversion, but handle pointer-to-member
3956 constants, where a null value is represented by an INTEGER_CST of
3960 cp_truthvalue_conversion (tree expr)
3962 tree type = TREE_TYPE (expr);
3963 if (TYPE_PTRMEM_P (type))
3964 return build_binary_op (NE_EXPR, expr, integer_zero_node, 1);
3966 return c_common_truthvalue_conversion (expr);
3969 /* Just like cp_truthvalue_conversion, but we want a CLEANUP_POINT_EXPR. */
3972 condition_conversion (tree expr)
3975 if (processing_template_decl)
3977 t = perform_implicit_conversion (boolean_type_node, expr);
3978 t = fold_build_cleanup_point_expr (boolean_type_node, t);
3982 /* Return an ADDR_EXPR giving the address of T. This function
3983 attempts no optimizations or simplifications; it is a low-level
3987 build_address (tree t)
3991 if (error_operand_p (t) || !cxx_mark_addressable (t))
3992 return error_mark_node;
3994 addr = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (t)), t);
3999 /* Return a NOP_EXPR converting EXPR to TYPE. */
4002 build_nop (tree type, tree expr)
4004 if (type == error_mark_node || error_operand_p (expr))
4006 return build1 (NOP_EXPR, type, expr);
4009 /* C++: Must handle pointers to members.
4011 Perhaps type instantiation should be extended to handle conversion
4012 from aggregates to types we don't yet know we want? (Or are those
4013 cases typically errors which should be reported?)
4015 NOCONVERT nonzero suppresses the default promotions
4016 (such as from short to int). */
4019 build_unary_op (enum tree_code code, tree xarg, int noconvert)
4021 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
4024 const char *errstring = NULL;
4026 const char *invalid_op_diag;
4028 if (arg == error_mark_node)
4029 return error_mark_node;
4031 if ((invalid_op_diag
4032 = targetm.invalid_unary_op ((code == UNARY_PLUS_EXPR
4037 error (invalid_op_diag, "");
4038 return error_mark_node;
4043 case UNARY_PLUS_EXPR:
4046 int flags = WANT_ARITH | WANT_ENUM;
4047 /* Unary plus (but not unary minus) is allowed on pointers. */
4048 if (code == UNARY_PLUS_EXPR)
4049 flags |= WANT_POINTER;
4050 arg = build_expr_type_conversion (flags, arg, true);
4052 errstring = (code == NEGATE_EXPR
4053 ? "wrong type argument to unary minus"
4054 : "wrong type argument to unary plus");
4057 if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4058 arg = perform_integral_promotions (arg);
4060 /* Make sure the result is not an lvalue: a unary plus or minus
4061 expression is always a rvalue. */
4068 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4072 arg = default_conversion (arg);
4074 else if (!(arg = build_expr_type_conversion (WANT_INT | WANT_ENUM
4077 errstring = "wrong type argument to bit-complement";
4078 else if (!noconvert && CP_INTEGRAL_TYPE_P (TREE_TYPE (arg)))
4079 arg = perform_integral_promotions (arg);
4083 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4084 errstring = "wrong type argument to abs";
4085 else if (!noconvert)
4086 arg = default_conversion (arg);
4090 /* Conjugating a real value is a no-op, but allow it anyway. */
4091 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_ENUM, arg, true)))
4092 errstring = "wrong type argument to conjugation";
4093 else if (!noconvert)
4094 arg = default_conversion (arg);
4097 case TRUTH_NOT_EXPR:
4098 arg = perform_implicit_conversion (boolean_type_node, arg);
4099 val = invert_truthvalue (arg);
4100 if (arg != error_mark_node)
4102 errstring = "in argument to unary !";
4109 if (TREE_CODE (arg) == COMPLEX_CST)
4110 return TREE_REALPART (arg);
4111 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4113 arg = build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4114 return fold_if_not_in_template (arg);
4120 if (TREE_CODE (arg) == COMPLEX_CST)
4121 return TREE_IMAGPART (arg);
4122 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4124 arg = build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
4125 return fold_if_not_in_template (arg);
4128 return cp_convert (TREE_TYPE (arg), integer_zero_node);
4130 case PREINCREMENT_EXPR:
4131 case POSTINCREMENT_EXPR:
4132 case PREDECREMENT_EXPR:
4133 case POSTDECREMENT_EXPR:
4134 /* Handle complex lvalues (when permitted)
4135 by reduction to simpler cases. */
4137 val = unary_complex_lvalue (code, arg);
4141 /* Increment or decrement the real part of the value,
4142 and don't change the imaginary part. */
4143 if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
4147 arg = stabilize_reference (arg);
4148 real = build_unary_op (REALPART_EXPR, arg, 1);
4149 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
4150 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
4151 build_unary_op (code, real, 1), imag);
4154 /* Report invalid types. */
4156 if (!(arg = build_expr_type_conversion (WANT_ARITH | WANT_POINTER,
4159 if (code == PREINCREMENT_EXPR)
4160 errstring ="no pre-increment operator for type";
4161 else if (code == POSTINCREMENT_EXPR)
4162 errstring ="no post-increment operator for type";
4163 else if (code == PREDECREMENT_EXPR)
4164 errstring ="no pre-decrement operator for type";
4166 errstring ="no post-decrement operator for type";
4170 /* Report something read-only. */
4172 if (CP_TYPE_CONST_P (TREE_TYPE (arg))
4173 || TREE_READONLY (arg))
4174 readonly_error (arg, ((code == PREINCREMENT_EXPR
4175 || code == POSTINCREMENT_EXPR)
4176 ? "increment" : "decrement"),
4182 tree result_type = TREE_TYPE (arg);
4184 declared_type = unlowered_expr_type (arg);
4186 arg = get_unwidened (arg, 0);
4187 argtype = TREE_TYPE (arg);
4189 /* ARM $5.2.5 last annotation says this should be forbidden. */
4190 if (TREE_CODE (argtype) == ENUMERAL_TYPE)
4191 pedwarn ("ISO C++ forbids %sing an enum",
4192 (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
4193 ? "increment" : "decrement");
4195 /* Compute the increment. */
4197 if (TREE_CODE (argtype) == POINTER_TYPE)
4199 tree type = complete_type (TREE_TYPE (argtype));
4201 if (!COMPLETE_OR_VOID_TYPE_P (type))
4202 error ("cannot %s a pointer to incomplete type %qT",
4203 ((code == PREINCREMENT_EXPR
4204 || code == POSTINCREMENT_EXPR)
4205 ? "increment" : "decrement"), TREE_TYPE (argtype));
4206 else if ((pedantic || warn_pointer_arith)
4207 && !TYPE_PTROB_P (argtype))
4208 pedwarn ("ISO C++ forbids %sing a pointer of type %qT",
4209 ((code == PREINCREMENT_EXPR
4210 || code == POSTINCREMENT_EXPR)
4211 ? "increment" : "decrement"), argtype);
4212 inc = cxx_sizeof_nowarn (TREE_TYPE (argtype));
4215 inc = integer_one_node;
4217 inc = cp_convert (argtype, inc);
4219 /* Handle incrementing a cast-expression. */
4221 switch (TREE_CODE (arg))
4226 case FIX_TRUNC_EXPR:
4227 case FIX_FLOOR_EXPR:
4228 case FIX_ROUND_EXPR:
4231 tree incremented, modify, value, compound;
4232 if (! lvalue_p (arg) && pedantic)
4233 pedwarn ("cast to non-reference type used as lvalue");
4234 arg = stabilize_reference (arg);
4235 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
4238 value = save_expr (arg);
4239 incremented = build2 (((code == PREINCREMENT_EXPR
4240 || code == POSTINCREMENT_EXPR)
4241 ? PLUS_EXPR : MINUS_EXPR),
4242 argtype, value, inc);
4244 modify = build_modify_expr (arg, NOP_EXPR, incremented);
4245 compound = build2 (COMPOUND_EXPR, TREE_TYPE (arg),
4248 /* Eliminate warning about unused result of + or -. */
4249 TREE_NO_WARNING (compound) = 1;
4257 /* Complain about anything else that is not a true lvalue. */
4258 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
4259 || code == POSTINCREMENT_EXPR)
4260 ? lv_increment : lv_decrement)))
4261 return error_mark_node;
4263 /* Forbid using -- on `bool'. */
4264 if (same_type_p (declared_type, boolean_type_node))
4266 if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
4268 error ("invalid use of %<--%> on bool variable %qD", arg);
4269 return error_mark_node;
4271 val = boolean_increment (code, arg);
4274 val = build2 (code, TREE_TYPE (arg), arg, inc);
4276 TREE_SIDE_EFFECTS (val) = 1;
4277 return cp_convert (result_type, val);
4281 /* Note that this operation never does default_conversion
4282 regardless of NOCONVERT. */
4284 argtype = lvalue_type (arg);
4286 if (TREE_CODE (arg) == OFFSET_REF)
4289 if (TREE_CODE (argtype) == REFERENCE_TYPE)
4291 tree type = build_pointer_type (TREE_TYPE (argtype));
4292 arg = build1 (CONVERT_EXPR, type, arg);
4295 else if (pedantic && DECL_MAIN_P (arg))
4297 pedwarn ("ISO C++ forbids taking address of function %<::main%>");
4299 /* Let &* cancel out to simplify resulting code. */
4300 if (TREE_CODE (arg) == INDIRECT_REF)
4302 /* We don't need to have `current_class_ptr' wrapped in a
4303 NON_LVALUE_EXPR node. */
4304 if (arg == current_class_ref)
4305 return current_class_ptr;
4307 arg = TREE_OPERAND (arg, 0);
4308 if (TREE_CODE (TREE_TYPE (arg)) == REFERENCE_TYPE)
4310 tree type = build_pointer_type (TREE_TYPE (TREE_TYPE (arg)));
4311 arg = build1 (CONVERT_EXPR, type, arg);
4314 /* Don't let this be an lvalue. */
4319 /* Uninstantiated types are all functions. Taking the
4320 address of a function is a no-op, so just return the
4323 gcc_assert (TREE_CODE (arg) != IDENTIFIER_NODE
4324 || !IDENTIFIER_OPNAME_P (arg));
4326 if (TREE_CODE (arg) == COMPONENT_REF && type_unknown_p (arg)
4327 && !really_overloaded_fn (TREE_OPERAND (arg, 1)))
4329 /* They're trying to take the address of a unique non-static
4330 member function. This is ill-formed (except in MS-land),
4331 but let's try to DTRT.
4332 Note: We only handle unique functions here because we don't
4333 want to complain if there's a static overload; non-unique
4334 cases will be handled by instantiate_type. But we need to
4335 handle this case here to allow casts on the resulting PMF.
4336 We could defer this in non-MS mode, but it's easier to give
4337 a useful error here. */
4339 /* Inside constant member functions, the `this' pointer
4340 contains an extra const qualifier. TYPE_MAIN_VARIANT
4341 is used here to remove this const from the diagnostics
4342 and the created OFFSET_REF. */
4343 tree base = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg, 0)));
4344 tree fn = get_first_fn (TREE_OPERAND (arg, 1));
4347 if (! flag_ms_extensions)
4349 tree name = DECL_NAME (fn);
4350 if (current_class_type
4351 && TREE_OPERAND (arg, 0) == current_class_ref)
4352 /* An expression like &memfn. */
4353 pedwarn ("ISO C++ forbids taking the address of an unqualified"
4354 " or parenthesized non-static member function to form"
4355 " a pointer to member function. Say %<&%T::%D%>",
4358 pedwarn ("ISO C++ forbids taking the address of a bound member"
4359 " function to form a pointer to member function."
4363 arg = build_offset_ref (base, fn, /*address_p=*/true);
4367 if (type_unknown_p (arg))
4368 return build1 (ADDR_EXPR, unknown_type_node, arg);
4370 /* Handle complex lvalues (when permitted)
4371 by reduction to simpler cases. */
4372 val = unary_complex_lvalue (code, arg);
4376 switch (TREE_CODE (arg))
4381 case FIX_TRUNC_EXPR:
4382 case FIX_FLOOR_EXPR:
4383 case FIX_ROUND_EXPR:
4385 if (! lvalue_p (arg) && pedantic)
4386 pedwarn ("ISO C++ forbids taking the address of a cast to a non-lvalue expression");
4390 arg = BASELINK_FUNCTIONS (arg);
4394 arg = OVL_CURRENT (arg);
4398 /* Turn a reference to a non-static data member into a
4399 pointer-to-member. */
4404 if (!PTRMEM_OK_P (arg))
4405 return build_unary_op (code, arg, 0);
4407 t = TREE_OPERAND (arg, 1);
4408 if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE)
4410 error ("cannot create pointer to reference member %qD", t);
4411 return error_mark_node;
4414 type = build_ptrmem_type (context_for_name_lookup (t),
4416 t = make_ptrmem_cst (type, TREE_OPERAND (arg, 1));
4424 /* Anything not already handled and not a true memory reference
4426 if (TREE_CODE (argtype) != FUNCTION_TYPE
4427 && TREE_CODE (argtype) != METHOD_TYPE
4428 && TREE_CODE (arg) != OFFSET_REF
4429 && !lvalue_or_else (arg, lv_addressof))
4430 return error_mark_node;
4432 if (argtype != error_mark_node)
4433 argtype = build_pointer_type (argtype);
4435 /* In a template, we are processing a non-dependent expression
4436 so we can just form an ADDR_EXPR with the correct type. */
4437 if (processing_template_decl)
4439 val = build_address (arg);
4440 if (TREE_CODE (arg) == OFFSET_REF)
4441 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4445 if (TREE_CODE (arg) != COMPONENT_REF)
4447 val = build_address (arg);
4448 if (TREE_CODE (arg) == OFFSET_REF)
4449 PTRMEM_OK_P (val) = PTRMEM_OK_P (arg);
4451 else if (TREE_CODE (TREE_OPERAND (arg, 1)) == BASELINK)
4453 tree fn = BASELINK_FUNCTIONS (TREE_OPERAND (arg, 1));
4455 /* We can only get here with a single static member
4457 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4458 && DECL_STATIC_FUNCTION_P (fn));
4460 val = build_address (fn);
4461 if (TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
4462 /* Do not lose object's side effects. */
4463 val = build2 (COMPOUND_EXPR, TREE_TYPE (val),
4464 TREE_OPERAND (arg, 0), val);
4466 else if (DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)))
4468 error ("attempt to take address of bit-field structure member %qD",
4469 TREE_OPERAND (arg, 1));
4470 return error_mark_node;
4474 tree object = TREE_OPERAND (arg, 0);
4475 tree field = TREE_OPERAND (arg, 1);
4476 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4477 (TREE_TYPE (object), decl_type_context (field)));
4478 val = build_address (arg);
4481 if (TREE_CODE (argtype) == POINTER_TYPE
4482 && TREE_CODE (TREE_TYPE (argtype)) == METHOD_TYPE)
4484 build_ptrmemfunc_type (argtype);
4485 val = build_ptrmemfunc (argtype, val, 0,
4486 /*c_cast_p=*/false);
4498 argtype = TREE_TYPE (arg);
4499 return fold_if_not_in_template (build1 (code, argtype, arg));
4502 error ("%s", errstring);
4503 return error_mark_node;
4506 /* Apply unary lvalue-demanding operator CODE to the expression ARG
4507 for certain kinds of expressions which are not really lvalues
4508 but which we can accept as lvalues.
4510 If ARG is not a kind of expression we can handle, return
4514 unary_complex_lvalue (enum tree_code code, tree arg)
4516 /* Inside a template, making these kinds of adjustments is
4517 pointless; we are only concerned with the type of the
4519 if (processing_template_decl)
4522 /* Handle (a, b) used as an "lvalue". */
4523 if (TREE_CODE (arg) == COMPOUND_EXPR)
4525 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
4526 return build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4527 TREE_OPERAND (arg, 0), real_result);
4530 /* Handle (a ? b : c) used as an "lvalue". */
4531 if (TREE_CODE (arg) == COND_EXPR
4532 || TREE_CODE (arg) == MIN_EXPR || TREE_CODE (arg) == MAX_EXPR)
4533 return rationalize_conditional_expr (code, arg);
4535 /* Handle (a = b), (++a), and (--a) used as an "lvalue". */
4536 if (TREE_CODE (arg) == MODIFY_EXPR
4537 || TREE_CODE (arg) == PREINCREMENT_EXPR
4538 || TREE_CODE (arg) == PREDECREMENT_EXPR)
4540 tree lvalue = TREE_OPERAND (arg, 0);
4541 if (TREE_SIDE_EFFECTS (lvalue))
4543 lvalue = stabilize_reference (lvalue);
4544 arg = build2 (TREE_CODE (arg), TREE_TYPE (arg),
4545 lvalue, TREE_OPERAND (arg, 1));
4547 return unary_complex_lvalue
4548 (code, build2 (COMPOUND_EXPR, TREE_TYPE (lvalue), arg, lvalue));
4551 if (code != ADDR_EXPR)
4554 /* Handle (a = b) used as an "lvalue" for `&'. */
4555 if (TREE_CODE (arg) == MODIFY_EXPR
4556 || TREE_CODE (arg) == INIT_EXPR)
4558 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 0), 0);
4559 arg = build2 (COMPOUND_EXPR, TREE_TYPE (real_result),
4561 TREE_NO_WARNING (arg) = 1;
4565 if (TREE_CODE (TREE_TYPE (arg)) == FUNCTION_TYPE
4566 || TREE_CODE (TREE_TYPE (arg)) == METHOD_TYPE
4567 || TREE_CODE (arg) == OFFSET_REF)
4570 /* We permit compiler to make function calls returning
4571 objects of aggregate type look like lvalues. */
4575 if (TREE_CODE (targ) == SAVE_EXPR)
4576 targ = TREE_OPERAND (targ, 0);
4578 if (TREE_CODE (targ) == CALL_EXPR && IS_AGGR_TYPE (TREE_TYPE (targ)))
4580 if (TREE_CODE (arg) == SAVE_EXPR)
4583 targ = build_cplus_new (TREE_TYPE (arg), arg);
4584 return build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (arg)), targ);
4587 if (TREE_CODE (arg) == SAVE_EXPR && TREE_CODE (targ) == INDIRECT_REF)
4588 return build3 (SAVE_EXPR, build_pointer_type (TREE_TYPE (arg)),
4589 TREE_OPERAND (targ, 0), current_function_decl, NULL);
4592 /* Don't let anything else be handled specially. */
4596 /* Mark EXP saying that we need to be able to take the
4597 address of it; it should not be allocated in a register.
4598 Value is true if successful.
4600 C++: we do not allow `current_class_ptr' to be addressable. */
4603 cxx_mark_addressable (tree exp)
4608 switch (TREE_CODE (x))
4615 x = TREE_OPERAND (x, 0);
4619 if (x == current_class_ptr)
4621 error ("cannot take the address of %<this%>, which is an rvalue expression");
4622 TREE_ADDRESSABLE (x) = 1; /* so compiler doesn't die later. */
4628 /* Caller should not be trying to mark initialized
4629 constant fields addressable. */
4630 gcc_assert (DECL_LANG_SPECIFIC (x) == 0
4631 || DECL_IN_AGGR_P (x) == 0
4633 || DECL_EXTERNAL (x));
4638 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
4639 && !DECL_ARTIFICIAL (x))
4641 if (TREE_CODE (x) == VAR_DECL && DECL_HARD_REGISTER (x))
4644 ("address of explicit register variable %qD requested", x);
4647 else if (extra_warnings)
4649 (OPT_Wextra, "address requested for %qD, which is declared %<register%>", x);
4651 TREE_ADDRESSABLE (x) = 1;
4655 TREE_ADDRESSABLE (x) = 1;
4659 TREE_ADDRESSABLE (x) = 1;
4663 TREE_ADDRESSABLE (x) = 1;
4664 cxx_mark_addressable (TREE_OPERAND (x, 0));
4672 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
4675 build_x_conditional_expr (tree ifexp, tree op1, tree op2)
4677 tree orig_ifexp = ifexp;
4678 tree orig_op1 = op1;
4679 tree orig_op2 = op2;
4682 if (processing_template_decl)
4684 /* The standard says that the expression is type-dependent if
4685 IFEXP is type-dependent, even though the eventual type of the
4686 expression doesn't dependent on IFEXP. */
4687 if (type_dependent_expression_p (ifexp)
4688 /* As a GNU extension, the middle operand may be omitted. */
4689 || (op1 && type_dependent_expression_p (op1))
4690 || type_dependent_expression_p (op2))
4691 return build_min_nt (COND_EXPR, ifexp, op1, op2);
4692 ifexp = build_non_dependent_expr (ifexp);
4694 op1 = build_non_dependent_expr (op1);
4695 op2 = build_non_dependent_expr (op2);
4698 expr = build_conditional_expr (ifexp, op1, op2);
4699 if (processing_template_decl && expr != error_mark_node)
4700 return build_min_non_dep (COND_EXPR, expr,
4701 orig_ifexp, orig_op1, orig_op2);
4705 /* Given a list of expressions, return a compound expression
4706 that performs them all and returns the value of the last of them. */
4708 tree build_x_compound_expr_from_list (tree list, const char *msg)
4710 tree expr = TREE_VALUE (list);
4712 if (TREE_CHAIN (list))
4715 pedwarn ("%s expression list treated as compound expression", msg);
4717 for (list = TREE_CHAIN (list); list; list = TREE_CHAIN (list))
4718 expr = build_x_compound_expr (expr, TREE_VALUE (list));
4724 /* Handle overloading of the ',' operator when needed. */
4727 build_x_compound_expr (tree op1, tree op2)
4730 tree orig_op1 = op1;
4731 tree orig_op2 = op2;
4733 if (processing_template_decl)
4735 if (type_dependent_expression_p (op1)
4736 || type_dependent_expression_p (op2))
4737 return build_min_nt (COMPOUND_EXPR, op1, op2);
4738 op1 = build_non_dependent_expr (op1);
4739 op2 = build_non_dependent_expr (op2);
4742 result = build_new_op (COMPOUND_EXPR, LOOKUP_NORMAL, op1, op2, NULL_TREE,
4743 /*overloaded_p=*/NULL);
4745 result = build_compound_expr (op1, op2);
4747 if (processing_template_decl && result != error_mark_node)
4748 return build_min_non_dep (COMPOUND_EXPR, result, orig_op1, orig_op2);
4753 /* Build a compound expression. */
4756 build_compound_expr (tree lhs, tree rhs)
4758 lhs = convert_to_void (lhs, "left-hand operand of comma");
4760 if (lhs == error_mark_node || rhs == error_mark_node)
4761 return error_mark_node;
4763 if (TREE_CODE (rhs) == TARGET_EXPR)
4765 /* If the rhs is a TARGET_EXPR, then build the compound
4766 expression inside the target_expr's initializer. This
4767 helps the compiler to eliminate unnecessary temporaries. */
4768 tree init = TREE_OPERAND (rhs, 1);
4770 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), lhs, init);
4771 TREE_OPERAND (rhs, 1) = init;
4776 return build2 (COMPOUND_EXPR, TREE_TYPE (rhs), lhs, rhs);
4779 /* Issue a diagnostic message if casting from SRC_TYPE to DEST_TYPE
4780 casts away constness. DIAG_FN gives the function to call if we
4781 need to issue a diagnostic; if it is NULL, no diagnostic will be
4782 issued. DESCRIPTION explains what operation is taking place. */
4785 check_for_casting_away_constness (tree src_type, tree dest_type,
4786 void (*diag_fn)(const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2),
4787 const char *description)
4789 if (diag_fn && casts_away_constness (src_type, dest_type))
4790 diag_fn ("%s from type %qT to type %qT casts away constness",
4791 description, src_type, dest_type);
4794 /* Convert EXPR (an expression with pointer-to-member type) to TYPE
4795 (another pointer-to-member type in the same hierarchy) and return
4796 the converted expression. If ALLOW_INVERSE_P is permitted, a
4797 pointer-to-derived may be converted to pointer-to-base; otherwise,
4798 only the other direction is permitted. If C_CAST_P is true, this
4799 conversion is taking place as part of a C-style cast. */
4802 convert_ptrmem (tree type, tree expr, bool allow_inverse_p,
4805 if (TYPE_PTRMEM_P (type))
4809 if (TREE_CODE (expr) == PTRMEM_CST)
4810 expr = cplus_expand_constant (expr);
4811 delta = get_delta_difference (TYPE_PTRMEM_CLASS_TYPE (TREE_TYPE (expr)),
4812 TYPE_PTRMEM_CLASS_TYPE (type),
4815 if (!integer_zerop (delta))
4816 expr = cp_build_binary_op (PLUS_EXPR,
4817 build_nop (ptrdiff_type_node, expr),
4819 return build_nop (type, expr);
4822 return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr,
4823 allow_inverse_p, c_cast_p);
4826 /* If EXPR is an INTEGER_CST and ORIG is an arithmetic constant, return
4827 a version of EXPR that has TREE_OVERFLOW and/or TREE_CONSTANT_OVERFLOW
4828 set iff they are set in ORIG. Otherwise, return EXPR unchanged. */
4831 ignore_overflows (tree expr, tree orig)
4833 if (TREE_CODE (expr) == INTEGER_CST
4834 && CONSTANT_CLASS_P (orig)
4835 && TREE_CODE (orig) != STRING_CST
4836 && (TREE_OVERFLOW (expr) != TREE_OVERFLOW (orig)
4837 || TREE_CONSTANT_OVERFLOW (expr)
4838 != TREE_CONSTANT_OVERFLOW (orig)))
4840 if (!TREE_OVERFLOW (orig) && !TREE_CONSTANT_OVERFLOW (orig))
4841 /* Ensure constant sharing. */
4842 expr = build_int_cst_wide (TREE_TYPE (expr),
4843 TREE_INT_CST_LOW (expr),
4844 TREE_INT_CST_HIGH (expr));
4847 /* Avoid clobbering a shared constant. */
4848 expr = copy_node (expr);
4849 TREE_OVERFLOW (expr) = TREE_OVERFLOW (orig);
4850 TREE_CONSTANT_OVERFLOW (expr)
4851 = TREE_CONSTANT_OVERFLOW (orig);
4857 /* Perform a static_cast from EXPR to TYPE. When C_CAST_P is true,
4858 this static_cast is being attempted as one of the possible casts
4859 allowed by a C-style cast. (In that case, accessibility of base
4860 classes is not considered, and it is OK to cast away
4861 constness.) Return the result of the cast. *VALID_P is set to
4862 indicate whether or not the cast was valid. */
4865 build_static_cast_1 (tree type, tree expr, bool c_cast_p,
4871 void (*diag_fn)(const char*, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
4874 /* Assume the cast is valid. */
4877 intype = TREE_TYPE (expr);
4879 /* Save casted types in the function's used types hash table. */
4880 used_types_insert (type);
4882 /* Determine what to do when casting away constness. */
4885 /* C-style casts are allowed to cast away constness. With
4886 WARN_CAST_QUAL, we still want to issue a warning. */
4887 diag_fn = warn_cast_qual ? warning0 : NULL;
4892 /* A static_cast may not cast away constness. */
4894 desc = "static_cast";
4897 /* [expr.static.cast]
4899 An lvalue of type "cv1 B", where B is a class type, can be cast
4900 to type "reference to cv2 D", where D is a class derived (clause
4901 _class.derived_) from B, if a valid standard conversion from
4902 "pointer to D" to "pointer to B" exists (_conv.ptr_), cv2 is the
4903 same cv-qualification as, or greater cv-qualification than, cv1,
4904 and B is not a virtual base class of D. */
4905 /* We check this case before checking the validity of "TYPE t =
4906 EXPR;" below because for this case:
4909 struct D : public B { D(const B&); };
4911 void f() { static_cast<const D&>(b); }
4913 we want to avoid constructing a new D. The standard is not
4914 completely clear about this issue, but our interpretation is
4915 consistent with other compilers. */
4916 if (TREE_CODE (type) == REFERENCE_TYPE
4917 && CLASS_TYPE_P (TREE_TYPE (type))
4918 && CLASS_TYPE_P (intype)
4919 && real_lvalue_p (expr)
4920 && DERIVED_FROM_P (intype, TREE_TYPE (type))
4921 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT (intype)),
4922 build_pointer_type (TYPE_MAIN_VARIANT
4923 (TREE_TYPE (type))))
4925 || at_least_as_qualified_p (TREE_TYPE (type), intype)))
4929 /* There is a standard conversion from "D*" to "B*" even if "B"
4930 is ambiguous or inaccessible. If this is really a
4931 static_cast, then we check both for inaccessibility and
4932 ambiguity. However, if this is a static_cast being performed
4933 because the user wrote a C-style cast, then accessibility is
4935 base = lookup_base (TREE_TYPE (type), intype,
4936 c_cast_p ? ba_unique : ba_check,
4939 /* Convert from "B*" to "D*". This function will check that "B"
4940 is not a virtual base of "D". */
4941 expr = build_base_path (MINUS_EXPR, build_address (expr),
4942 base, /*nonnull=*/false);
4943 /* Convert the pointer to a reference -- but then remember that
4944 there are no expressions with reference type in C++. */
4945 return convert_from_reference (build_nop (type, expr));
4950 /* [expr.static.cast]
4952 An expression e can be explicitly converted to a type T using a
4953 static_cast of the form static_cast<T>(e) if the declaration T
4954 t(e);" is well-formed, for some invented temporary variable
4956 result = perform_direct_initialization_if_possible (type, expr,
4960 result = convert_from_reference (result);
4962 /* Ignore any integer overflow caused by the cast. */
4963 result = ignore_overflows (result, orig);
4965 /* [expr.static.cast]
4967 If T is a reference type, the result is an lvalue; otherwise,
4968 the result is an rvalue. */
4969 if (TREE_CODE (type) != REFERENCE_TYPE)
4970 result = rvalue (result);
4974 /* [expr.static.cast]
4976 Any expression can be explicitly converted to type cv void. */
4977 if (TREE_CODE (type) == VOID_TYPE)
4978 return convert_to_void (expr, /*implicit=*/NULL);
4980 /* [expr.static.cast]
4982 The inverse of any standard conversion sequence (clause _conv_),
4983 other than the lvalue-to-rvalue (_conv.lval_), array-to-pointer
4984 (_conv.array_), function-to-pointer (_conv.func_), and boolean
4985 (_conv.bool_) conversions, can be performed explicitly using
4986 static_cast subject to the restriction that the explicit
4987 conversion does not cast away constness (_expr.const.cast_), and
4988 the following additional rules for specific cases: */
4989 /* For reference, the conversions not excluded are: integral
4990 promotions, floating point promotion, integral conversions,
4991 floating point conversions, floating-integral conversions,
4992 pointer conversions, and pointer to member conversions. */
4995 A value of integral _or enumeration_ type can be explicitly
4996 converted to an enumeration type. */
4997 /* The effect of all that is that any conversion between any two
4998 types which are integral, floating, or enumeration types can be
5000 if ((INTEGRAL_TYPE_P (type) || SCALAR_FLOAT_TYPE_P (type))
5001 && (INTEGRAL_TYPE_P (intype) || SCALAR_FLOAT_TYPE_P (intype)))
5003 expr = ocp_convert (type, expr, CONV_C_CAST, LOOKUP_NORMAL);
5005 /* Ignore any integer overflow caused by the cast. */
5006 expr = ignore_overflows (expr, orig);
5010 if (TYPE_PTR_P (type) && TYPE_PTR_P (intype)
5011 && CLASS_TYPE_P (TREE_TYPE (type))
5012 && CLASS_TYPE_P (TREE_TYPE (intype))
5013 && can_convert (build_pointer_type (TYPE_MAIN_VARIANT
5014 (TREE_TYPE (intype))),
5015 build_pointer_type (TYPE_MAIN_VARIANT
5016 (TREE_TYPE (type)))))
5021 check_for_casting_away_constness (intype, type, diag_fn, desc);
5022 base = lookup_base (TREE_TYPE (type), TREE_TYPE (intype),
5023 c_cast_p ? ba_unique : ba_check,
5025 return build_base_path (MINUS_EXPR, expr, base, /*nonnull=*/false);
5028 if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5029 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5036 c1 = TYPE_PTRMEM_CLASS_TYPE (intype);
5037 c2 = TYPE_PTRMEM_CLASS_TYPE (type);
5039 if (TYPE_PTRMEM_P (type))
5041 t1 = (build_ptrmem_type
5043 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (intype))));
5044 t2 = (build_ptrmem_type
5046 TYPE_MAIN_VARIANT (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
5053 if (can_convert (t1, t2))
5056 check_for_casting_away_constness (intype, type, diag_fn,
5058 return convert_ptrmem (type, expr, /*allow_inverse_p=*/1,
5063 /* [expr.static.cast]
5065 An rvalue of type "pointer to cv void" can be explicitly
5066 converted to a pointer to object type. A value of type pointer
5067 to object converted to "pointer to cv void" and back to the
5068 original pointer type will have its original value. */
5069 if (TREE_CODE (intype) == POINTER_TYPE
5070 && VOID_TYPE_P (TREE_TYPE (intype))
5071 && TYPE_PTROB_P (type))
5074 check_for_casting_away_constness (intype, type, diag_fn, desc);
5075 return build_nop (type, expr);
5079 return error_mark_node;
5082 /* Return an expression representing static_cast<TYPE>(EXPR). */
5085 build_static_cast (tree type, tree expr)
5090 if (type == error_mark_node || expr == error_mark_node)
5091 return error_mark_node;
5093 if (processing_template_decl)
5095 expr = build_min (STATIC_CAST_EXPR, type, expr);
5096 /* We don't know if it will or will not have side effects. */
5097 TREE_SIDE_EFFECTS (expr) = 1;
5098 return convert_from_reference (expr);
5101 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5102 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5103 if (TREE_CODE (type) != REFERENCE_TYPE
5104 && TREE_CODE (expr) == NOP_EXPR
5105 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5106 expr = TREE_OPERAND (expr, 0);
5108 result = build_static_cast_1 (type, expr, /*c_cast_p=*/false, &valid_p);
5112 error ("invalid static_cast from type %qT to type %qT",
5113 TREE_TYPE (expr), type);
5114 return error_mark_node;
5117 /* EXPR is an expression with member function or pointer-to-member
5118 function type. TYPE is a pointer type. Converting EXPR to TYPE is
5119 not permitted by ISO C++, but we accept it in some modes. If we
5120 are not in one of those modes, issue a diagnostic. Return the
5121 converted expression. */
5124 convert_member_func_to_ptr (tree type, tree expr)
5129 intype = TREE_TYPE (expr);
5130 gcc_assert (TYPE_PTRMEMFUNC_P (intype)
5131 || TREE_CODE (intype) == METHOD_TYPE);
5133 if (pedantic || warn_pmf2ptr)
5134 pedwarn ("converting from %qT to %qT", intype, type);
5136 if (TREE_CODE (intype) == METHOD_TYPE)
5137 expr = build_addr_func (expr);
5138 else if (TREE_CODE (expr) == PTRMEM_CST)
5139 expr = build_address (PTRMEM_CST_MEMBER (expr));
5142 decl = maybe_dummy_object (TYPE_PTRMEM_CLASS_TYPE (intype), 0);
5143 decl = build_address (decl);
5144 expr = get_member_function_from_ptrfunc (&decl, expr);
5147 return build_nop (type, expr);
5150 /* Return a representation for a reinterpret_cast from EXPR to TYPE.
5151 If C_CAST_P is true, this reinterpret cast is being done as part of
5152 a C-style cast. If VALID_P is non-NULL, *VALID_P is set to
5153 indicate whether or not reinterpret_cast was valid. */
5156 build_reinterpret_cast_1 (tree type, tree expr, bool c_cast_p,
5161 /* Assume the cast is invalid. */
5165 if (type == error_mark_node || error_operand_p (expr))
5166 return error_mark_node;
5168 intype = TREE_TYPE (expr);
5170 /* Save casted types in the function's used types hash table. */
5171 used_types_insert (type);
5173 /* [expr.reinterpret.cast]
5174 An lvalue expression of type T1 can be cast to the type
5175 "reference to T2" if an expression of type "pointer to T1" can be
5176 explicitly converted to the type "pointer to T2" using a
5177 reinterpret_cast. */
5178 if (TREE_CODE (type) == REFERENCE_TYPE)
5180 if (! real_lvalue_p (expr))
5182 error ("invalid cast of an rvalue expression of type "
5185 return error_mark_node;
5188 /* Warn about a reinterpret_cast from "A*" to "B&" if "A" and
5189 "B" are related class types; the reinterpret_cast does not
5190 adjust the pointer. */
5191 if (TYPE_PTR_P (intype)
5192 && (comptypes (TREE_TYPE (intype), TREE_TYPE (type),
5193 COMPARE_BASE | COMPARE_DERIVED)))
5194 warning (0, "casting %qT to %qT does not dereference pointer",
5197 expr = build_unary_op (ADDR_EXPR, expr, 0);
5198 if (expr != error_mark_node)
5199 expr = build_reinterpret_cast_1
5200 (build_pointer_type (TREE_TYPE (type)), expr, c_cast_p,
5202 if (expr != error_mark_node)
5203 expr = build_indirect_ref (expr, 0);
5207 /* As a G++ extension, we consider conversions from member
5208 functions, and pointers to member functions to
5209 pointer-to-function and pointer-to-void types. If
5210 -Wno-pmf-conversions has not been specified,
5211 convert_member_func_to_ptr will issue an error message. */
5212 if ((TYPE_PTRMEMFUNC_P (intype)
5213 || TREE_CODE (intype) == METHOD_TYPE)
5214 && TYPE_PTR_P (type)
5215 && (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
5216 || VOID_TYPE_P (TREE_TYPE (type))))
5217 return convert_member_func_to_ptr (type, expr);
5219 /* If the cast is not to a reference type, the lvalue-to-rvalue,
5220 array-to-pointer, and function-to-pointer conversions are
5222 expr = decay_conversion (expr);
5224 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5225 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5226 if (TREE_CODE (expr) == NOP_EXPR
5227 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5228 expr = TREE_OPERAND (expr, 0);
5230 if (error_operand_p (expr))
5231 return error_mark_node;
5233 intype = TREE_TYPE (expr);
5235 /* [expr.reinterpret.cast]
5236 A pointer can be converted to any integral type large enough to
5238 if (CP_INTEGRAL_TYPE_P (type) && TYPE_PTR_P (intype))
5240 if (TYPE_PRECISION (type) < TYPE_PRECISION (intype))
5241 pedwarn ("cast from %qT to %qT loses precision",
5244 /* [expr.reinterpret.cast]
5245 A value of integral or enumeration type can be explicitly
5246 converted to a pointer. */
5247 else if (TYPE_PTR_P (type) && INTEGRAL_OR_ENUMERATION_TYPE_P (intype))
5250 else if ((TYPE_PTRFN_P (type) && TYPE_PTRFN_P (intype))
5251 || (TYPE_PTRMEMFUNC_P (type) && TYPE_PTRMEMFUNC_P (intype)))
5252 return fold_if_not_in_template (build_nop (type, expr));
5253 else if ((TYPE_PTRMEM_P (type) && TYPE_PTRMEM_P (intype))
5254 || (TYPE_PTROBV_P (type) && TYPE_PTROBV_P (intype)))
5259 check_for_casting_away_constness (intype, type, error,
5260 "reinterpret_cast");
5261 /* Warn about possible alignment problems. */
5262 if (STRICT_ALIGNMENT && warn_cast_align
5263 && !VOID_TYPE_P (type)
5264 && TREE_CODE (TREE_TYPE (intype)) != FUNCTION_TYPE
5265 && COMPLETE_TYPE_P (TREE_TYPE (type))
5266 && COMPLETE_TYPE_P (TREE_TYPE (intype))
5267 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (intype)))
5268 warning (0, "cast from %qT to %qT increases required alignment of "
5272 /* We need to strip nops here, because the frontend likes to
5273 create (int *)&a for array-to-pointer decay, instead of &a[0]. */
5275 if (warn_strict_aliasing <= 2)
5276 strict_aliasing_warning (intype, type, sexpr);
5278 return fold_if_not_in_template (build_nop (type, expr));
5280 else if ((TYPE_PTRFN_P (type) && TYPE_PTROBV_P (intype))
5281 || (TYPE_PTRFN_P (intype) && TYPE_PTROBV_P (type)))
5284 /* Only issue a warning, as we have always supported this
5285 where possible, and it is necessary in some cases. DR 195
5286 addresses this issue, but as of 2004/10/26 is still in
5288 warning (0, "ISO C++ forbids casting between pointer-to-function and pointer-to-object");
5289 return fold_if_not_in_template (build_nop (type, expr));
5291 else if (TREE_CODE (type) == VECTOR_TYPE)
5292 return fold_if_not_in_template (convert_to_vector (type, expr));
5293 else if (TREE_CODE (intype) == VECTOR_TYPE && INTEGRAL_TYPE_P (type))
5294 return fold_if_not_in_template (convert_to_integer (type, expr));
5299 error ("invalid cast from type %qT to type %qT", intype, type);
5300 return error_mark_node;
5303 return cp_convert (type, expr);
5307 build_reinterpret_cast (tree type, tree expr)
5309 if (type == error_mark_node || expr == error_mark_node)
5310 return error_mark_node;
5312 if (processing_template_decl)
5314 tree t = build_min (REINTERPRET_CAST_EXPR, type, expr);
5316 if (!TREE_SIDE_EFFECTS (t)
5317 && type_dependent_expression_p (expr))
5318 /* There might turn out to be side effects inside expr. */
5319 TREE_SIDE_EFFECTS (t) = 1;
5320 return convert_from_reference (t);
5323 return build_reinterpret_cast_1 (type, expr, /*c_cast_p=*/false,
5327 /* Perform a const_cast from EXPR to TYPE. If the cast is valid,
5328 return an appropriate expression. Otherwise, return
5329 error_mark_node. If the cast is not valid, and COMPLAIN is true,
5330 then a diagnostic will be issued. If VALID_P is non-NULL, we are
5331 performing a C-style cast, its value upon return will indicate
5332 whether or not the conversion succeeded. */
5335 build_const_cast_1 (tree dst_type, tree expr, bool complain,
5339 tree reference_type;
5341 /* Callers are responsible for handling error_mark_node as a
5342 destination type. */
5343 gcc_assert (dst_type != error_mark_node);
5344 /* In a template, callers should be building syntactic
5345 representations of casts, not using this machinery. */
5346 gcc_assert (!processing_template_decl);
5348 /* Assume the conversion is invalid. */
5352 if (!POINTER_TYPE_P (dst_type) && !TYPE_PTRMEM_P (dst_type))
5355 error ("invalid use of const_cast with type %qT, "
5356 "which is not a pointer, "
5357 "reference, nor a pointer-to-data-member type", dst_type);
5358 return error_mark_node;
5361 if (TREE_CODE (TREE_TYPE (dst_type)) == FUNCTION_TYPE)
5364 error ("invalid use of const_cast with type %qT, which is a pointer "
5365 "or reference to a function type", dst_type);
5366 return error_mark_node;
5369 /* Save casted types in the function's used types hash table. */
5370 used_types_insert (dst_type);
5372 src_type = TREE_TYPE (expr);
5373 /* Expressions do not really have reference types. */
5374 if (TREE_CODE (src_type) == REFERENCE_TYPE)
5375 src_type = TREE_TYPE (src_type);
5377 /* [expr.const.cast]
5379 An lvalue of type T1 can be explicitly converted to an lvalue of
5380 type T2 using the cast const_cast<T2&> (where T1 and T2 are object
5381 types) if a pointer to T1 can be explicitly converted to the type
5382 pointer to T2 using a const_cast. */
5383 if (TREE_CODE (dst_type) == REFERENCE_TYPE)
5385 reference_type = dst_type;
5386 if (! real_lvalue_p (expr))
5389 error ("invalid const_cast of an rvalue of type %qT to type %qT",
5390 src_type, dst_type);
5391 return error_mark_node;
5393 dst_type = build_pointer_type (TREE_TYPE (dst_type));
5394 src_type = build_pointer_type (src_type);
5398 reference_type = NULL_TREE;
5399 /* If the destination type is not a reference type, the
5400 lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5401 conversions are performed. */
5402 src_type = type_decays_to (src_type);
5403 if (src_type == error_mark_node)
5404 return error_mark_node;
5407 if ((TYPE_PTR_P (src_type) || TYPE_PTRMEM_P (src_type))
5408 && comp_ptr_ttypes_const (dst_type, src_type))
5413 /* This cast is actually a C-style cast. Issue a warning if
5414 the user is making a potentially unsafe cast. */
5416 check_for_casting_away_constness (src_type, dst_type,
5422 expr = build_unary_op (ADDR_EXPR, expr, 0);
5423 expr = build_nop (reference_type, expr);
5424 return convert_from_reference (expr);
5428 expr = decay_conversion (expr);
5429 /* build_c_cast puts on a NOP_EXPR to make the result not an
5430 lvalue. Strip such NOP_EXPRs if VALUE is being used in
5431 non-lvalue context. */
5432 if (TREE_CODE (expr) == NOP_EXPR
5433 && TREE_TYPE (expr) == TREE_TYPE (TREE_OPERAND (expr, 0)))
5434 expr = TREE_OPERAND (expr, 0);
5435 return build_nop (dst_type, expr);
5440 error ("invalid const_cast from type %qT to type %qT",
5441 src_type, dst_type);
5442 return error_mark_node;
5446 build_const_cast (tree type, tree expr)
5448 if (type == error_mark_node || error_operand_p (expr))
5449 return error_mark_node;
5451 if (processing_template_decl)
5453 tree t = build_min (CONST_CAST_EXPR, type, expr);
5455 if (!TREE_SIDE_EFFECTS (t)
5456 && type_dependent_expression_p (expr))
5457 /* There might turn out to be side effects inside expr. */
5458 TREE_SIDE_EFFECTS (t) = 1;
5459 return convert_from_reference (t);
5462 return build_const_cast_1 (type, expr, /*complain=*/true,
5466 /* Build an expression representing an explicit C-style cast to type
5467 TYPE of expression EXPR. */
5470 build_c_cast (tree type, tree expr)
5476 if (type == error_mark_node || error_operand_p (expr))
5477 return error_mark_node;
5479 if (processing_template_decl)
5481 tree t = build_min (CAST_EXPR, type,
5482 tree_cons (NULL_TREE, value, NULL_TREE));
5483 /* We don't know if it will or will not have side effects. */
5484 TREE_SIDE_EFFECTS (t) = 1;
5485 return convert_from_reference (t);
5488 /* Casts to a (pointer to a) specific ObjC class (or 'id' or
5489 'Class') should always be retained, because this information aids
5490 in method lookup. */
5491 if (objc_is_object_ptr (type)
5492 && objc_is_object_ptr (TREE_TYPE (expr)))
5493 return build_nop (type, expr);
5495 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
5496 Strip such NOP_EXPRs if VALUE is being used in non-lvalue context. */
5497 if (TREE_CODE (type) != REFERENCE_TYPE
5498 && TREE_CODE (value) == NOP_EXPR
5499 && TREE_TYPE (value) == TREE_TYPE (TREE_OPERAND (value, 0)))
5500 value = TREE_OPERAND (value, 0);
5502 if (TREE_CODE (type) == ARRAY_TYPE)
5504 /* Allow casting from T1* to T2[] because Cfront allows it.
5505 NIHCL uses it. It is not valid ISO C++ however. */
5506 if (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5508 pedwarn ("ISO C++ forbids casting to an array type %qT", type);
5509 type = build_pointer_type (TREE_TYPE (type));
5513 error ("ISO C++ forbids casting to an array type %qT", type);
5514 return error_mark_node;
5518 if (TREE_CODE (type) == FUNCTION_TYPE
5519 || TREE_CODE (type) == METHOD_TYPE)
5521 error ("invalid cast to function type %qT", type);
5522 return error_mark_node;
5525 /* A C-style cast can be a const_cast. */
5526 result = build_const_cast_1 (type, value, /*complain=*/false,
5531 /* Or a static cast. */
5532 result = build_static_cast_1 (type, value, /*c_cast_p=*/true,
5534 /* Or a reinterpret_cast. */
5536 result = build_reinterpret_cast_1 (type, value, /*c_cast_p=*/true,
5538 /* The static_cast or reinterpret_cast may be followed by a
5541 /* A valid cast may result in errors if, for example, a
5542 conversion to am ambiguous base class is required. */
5543 && !error_operand_p (result))
5547 /* Non-class rvalues always have cv-unqualified type. */
5548 if (!CLASS_TYPE_P (type))
5549 type = TYPE_MAIN_VARIANT (type);
5550 result_type = TREE_TYPE (result);
5551 if (!CLASS_TYPE_P (result_type))
5552 result_type = TYPE_MAIN_VARIANT (result_type);
5553 /* If the type of RESULT does not match TYPE, perform a
5554 const_cast to make it match. If the static_cast or
5555 reinterpret_cast succeeded, we will differ by at most
5556 cv-qualification, so the follow-on const_cast is guaranteed
5558 if (!same_type_p (non_reference (type), non_reference (result_type)))
5560 result = build_const_cast_1 (type, result, false, &valid_p);
5561 gcc_assert (valid_p);
5566 return error_mark_node;
5569 /* Build an assignment expression of lvalue LHS from value RHS.
5570 MODIFYCODE is the code for a binary operator that we use
5571 to combine the old value of LHS with RHS to get the new value.
5572 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment.
5574 C++: If MODIFYCODE is INIT_EXPR, then leave references unbashed. */
5577 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5581 tree lhstype = TREE_TYPE (lhs);
5582 tree olhstype = lhstype;
5583 tree olhs = NULL_TREE;
5584 bool plain_assign = (modifycode == NOP_EXPR);
5586 /* Avoid duplicate error messages from operands that had errors. */
5587 if (error_operand_p (lhs) || error_operand_p (rhs))
5588 return error_mark_node;
5590 /* Handle control structure constructs used as "lvalues". */
5591 switch (TREE_CODE (lhs))
5593 /* Handle --foo = 5; as these are valid constructs in C++. */
5594 case PREDECREMENT_EXPR:
5595 case PREINCREMENT_EXPR:
5596 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5597 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5598 stabilize_reference (TREE_OPERAND (lhs, 0)),
5599 TREE_OPERAND (lhs, 1));
5600 return build2 (COMPOUND_EXPR, lhstype,
5602 build_modify_expr (TREE_OPERAND (lhs, 0),
5605 /* Handle (a, b) used as an "lvalue". */
5607 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1),
5609 if (newrhs == error_mark_node)
5610 return error_mark_node;
5611 return build2 (COMPOUND_EXPR, lhstype,
5612 TREE_OPERAND (lhs, 0), newrhs);
5615 if (TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0)))
5616 lhs = build2 (TREE_CODE (lhs), TREE_TYPE (lhs),
5617 stabilize_reference (TREE_OPERAND (lhs, 0)),
5618 TREE_OPERAND (lhs, 1));
5619 newrhs = build_modify_expr (TREE_OPERAND (lhs, 0), modifycode, rhs);
5620 if (newrhs == error_mark_node)
5621 return error_mark_node;
5622 return build2 (COMPOUND_EXPR, lhstype, lhs, newrhs);
5626 /* MIN_EXPR and MAX_EXPR are currently only permitted as lvalues,
5627 when neither operand has side-effects. */
5628 if (!lvalue_or_else (lhs, lv_assign))
5629 return error_mark_node;
5631 gcc_assert (!TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 0))
5632 && !TREE_SIDE_EFFECTS (TREE_OPERAND (lhs, 1)));
5634 lhs = build3 (COND_EXPR, TREE_TYPE (lhs),
5635 build2 (TREE_CODE (lhs) == MIN_EXPR ? LE_EXPR : GE_EXPR,
5637 TREE_OPERAND (lhs, 0),
5638 TREE_OPERAND (lhs, 1)),
5639 TREE_OPERAND (lhs, 0),
5640 TREE_OPERAND (lhs, 1));
5643 /* Handle (a ? b : c) used as an "lvalue". */
5646 /* Produce (a ? (b = rhs) : (c = rhs))
5647 except that the RHS goes through a save-expr
5648 so the code to compute it is only emitted once. */
5650 tree preeval = NULL_TREE;
5652 if (VOID_TYPE_P (TREE_TYPE (rhs)))
5654 error ("void value not ignored as it ought to be");
5655 return error_mark_node;
5658 rhs = stabilize_expr (rhs, &preeval);
5660 /* Check this here to avoid odd errors when trying to convert
5661 a throw to the type of the COND_EXPR. */
5662 if (!lvalue_or_else (lhs, lv_assign))
5663 return error_mark_node;
5665 cond = build_conditional_expr
5666 (TREE_OPERAND (lhs, 0),
5667 build_modify_expr (TREE_OPERAND (lhs, 1),
5669 build_modify_expr (TREE_OPERAND (lhs, 2),
5672 if (cond == error_mark_node)
5674 /* Make sure the code to compute the rhs comes out
5675 before the split. */
5677 cond = build2 (COMPOUND_EXPR, TREE_TYPE (lhs), preeval, cond);
5685 if (modifycode == INIT_EXPR)
5687 if (TREE_CODE (rhs) == CONSTRUCTOR)
5689 if (! same_type_p (TREE_TYPE (rhs), lhstype))
5690 /* Call convert to generate an error; see PR 11063. */
5691 rhs = convert (lhstype, rhs);
5692 result = build2 (INIT_EXPR, lhstype, lhs, rhs);
5693 TREE_SIDE_EFFECTS (result) = 1;
5696 else if (! IS_AGGR_TYPE (lhstype))
5697 /* Do the default thing. */;
5700 result = build_special_member_call (lhs, complete_ctor_identifier,
5701 build_tree_list (NULL_TREE, rhs),
5702 lhstype, LOOKUP_NORMAL);
5703 if (result == NULL_TREE)
5704 return error_mark_node;
5710 lhs = require_complete_type (lhs);
5711 if (lhs == error_mark_node)
5712 return error_mark_node;
5714 if (modifycode == NOP_EXPR)
5716 /* `operator=' is not an inheritable operator. */
5717 if (! IS_AGGR_TYPE (lhstype))
5718 /* Do the default thing. */;
5721 result = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL,
5722 lhs, rhs, make_node (NOP_EXPR),
5723 /*overloaded_p=*/NULL);
5724 if (result == NULL_TREE)
5725 return error_mark_node;
5732 /* A binary op has been requested. Combine the old LHS
5733 value with the RHS producing the value we should actually
5734 store into the LHS. */
5736 gcc_assert (!PROMOTES_TO_AGGR_TYPE (lhstype, REFERENCE_TYPE));
5737 lhs = stabilize_reference (lhs);
5738 newrhs = cp_build_binary_op (modifycode, lhs, rhs);
5739 if (newrhs == error_mark_node)
5741 error (" in evaluation of %<%Q(%#T, %#T)%>", modifycode,
5742 TREE_TYPE (lhs), TREE_TYPE (rhs));
5743 return error_mark_node;
5746 /* Now it looks like a plain assignment. */
5747 modifycode = NOP_EXPR;
5749 gcc_assert (TREE_CODE (lhstype) != REFERENCE_TYPE);
5750 gcc_assert (TREE_CODE (TREE_TYPE (newrhs)) != REFERENCE_TYPE);
5753 /* The left-hand side must be an lvalue. */
5754 if (!lvalue_or_else (lhs, lv_assign))
5755 return error_mark_node;
5757 /* Warn about modifying something that is `const'. Don't warn if
5758 this is initialization. */
5759 if (modifycode != INIT_EXPR
5760 && (TREE_READONLY (lhs) || CP_TYPE_CONST_P (lhstype)
5761 /* Functions are not modifiable, even though they are
5763 || TREE_CODE (TREE_TYPE (lhs)) == FUNCTION_TYPE
5764 || TREE_CODE (TREE_TYPE (lhs)) == METHOD_TYPE
5765 /* If it's an aggregate and any field is const, then it is
5766 effectively const. */
5767 || (CLASS_TYPE_P (lhstype)
5768 && C_TYPE_FIELDS_READONLY (lhstype))))
5769 readonly_error (lhs, "assignment", 0);
5771 /* If storing into a structure or union member, it has probably been
5772 given type `int'. Compute the type that would go with the actual
5773 amount of storage the member occupies. */
5775 if (TREE_CODE (lhs) == COMPONENT_REF
5776 && (TREE_CODE (lhstype) == INTEGER_TYPE
5777 || TREE_CODE (lhstype) == REAL_TYPE
5778 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
5780 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
5782 /* If storing in a field that is in actuality a short or narrower
5783 than one, we must store in the field in its actual type. */
5785 if (lhstype != TREE_TYPE (lhs))
5787 /* Avoid warnings converting integral types back into enums for
5789 if (TREE_CODE (lhstype) == INTEGER_TYPE
5790 && TREE_CODE (olhstype) == ENUMERAL_TYPE)
5792 if (TREE_SIDE_EFFECTS (lhs))
5793 lhs = stabilize_reference (lhs);
5796 lhs = copy_node (lhs);
5797 TREE_TYPE (lhs) = lhstype;
5801 /* Convert new value to destination type. */
5803 if (TREE_CODE (lhstype) == ARRAY_TYPE)
5807 if (!same_or_base_type_p (TYPE_MAIN_VARIANT (lhstype),
5808 TYPE_MAIN_VARIANT (TREE_TYPE (rhs))))
5810 error ("incompatible types in assignment of %qT to %qT",
5811 TREE_TYPE (rhs), lhstype);
5812 return error_mark_node;
5815 /* Allow array assignment in compiler-generated code. */
5816 if (! DECL_ARTIFICIAL (current_function_decl))
5818 /* This routine is used for both initialization and assignment.
5819 Make sure the diagnostic message differentiates the context. */
5820 if (modifycode == INIT_EXPR)
5821 error ("array used as initializer");
5823 error ("invalid array assignment");
5824 return error_mark_node;
5827 from_array = TREE_CODE (TREE_TYPE (newrhs)) == ARRAY_TYPE
5828 ? 1 + (modifycode != INIT_EXPR): 0;
5829 return build_vec_init (lhs, NULL_TREE, newrhs,
5830 /*explicit_default_init_p=*/false,
5834 if (modifycode == INIT_EXPR)
5835 newrhs = convert_for_initialization (lhs, lhstype, newrhs, LOOKUP_NORMAL,
5836 "initialization", NULL_TREE, 0);
5839 /* Avoid warnings on enum bit fields. */
5840 if (TREE_CODE (olhstype) == ENUMERAL_TYPE
5841 && TREE_CODE (lhstype) == INTEGER_TYPE)
5843 newrhs = convert_for_assignment (olhstype, newrhs, "assignment",
5845 newrhs = convert_force (lhstype, newrhs, 0);
5848 newrhs = convert_for_assignment (lhstype, newrhs, "assignment",
5850 if (TREE_CODE (newrhs) == CALL_EXPR
5851 && TYPE_NEEDS_CONSTRUCTING (lhstype))
5852 newrhs = build_cplus_new (lhstype, newrhs);
5854 /* Can't initialize directly from a TARGET_EXPR, since that would
5855 cause the lhs to be constructed twice, and possibly result in
5856 accidental self-initialization. So we force the TARGET_EXPR to be
5857 expanded without a target. */
5858 if (TREE_CODE (newrhs) == TARGET_EXPR)
5859 newrhs = build2 (COMPOUND_EXPR, TREE_TYPE (newrhs), newrhs,
5860 TREE_OPERAND (newrhs, 0));
5863 if (newrhs == error_mark_node)
5864 return error_mark_node;
5866 if (c_dialect_objc () && flag_objc_gc)
5868 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
5874 result = build2 (modifycode == NOP_EXPR ? MODIFY_EXPR : INIT_EXPR,
5875 lhstype, lhs, newrhs);
5877 TREE_SIDE_EFFECTS (result) = 1;
5879 TREE_NO_WARNING (result) = 1;
5881 /* If we got the LHS in a different type for storing in,
5882 convert the result back to the nominal type of LHS
5883 so that the value we return always has the same type
5884 as the LHS argument. */
5886 if (olhstype == TREE_TYPE (result))
5890 result = build2 (COMPOUND_EXPR, olhstype, result, olhs);
5891 TREE_NO_WARNING (result) = 1;
5894 return convert_for_assignment (olhstype, result, "assignment",
5899 build_x_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
5901 if (processing_template_decl)
5902 return build_min_nt (MODOP_EXPR, lhs,
5903 build_min_nt (modifycode, NULL_TREE, NULL_TREE), rhs);
5905 if (modifycode != NOP_EXPR)
5907 tree rval = build_new_op (MODIFY_EXPR, LOOKUP_NORMAL, lhs, rhs,
5908 make_node (modifycode),
5909 /*overloaded_p=*/NULL);
5912 TREE_NO_WARNING (rval) = 1;
5916 return build_modify_expr (lhs, modifycode, rhs);
5920 /* Get difference in deltas for different pointer to member function
5921 types. Returns an integer constant of type PTRDIFF_TYPE_NODE. If
5922 the conversion is invalid, the constant is zero. If
5923 ALLOW_INVERSE_P is true, then allow reverse conversions as well.
5924 If C_CAST_P is true this conversion is taking place as part of a
5927 Note that the naming of FROM and TO is kind of backwards; the return
5928 value is what we add to a TO in order to get a FROM. They are named
5929 this way because we call this function to find out how to convert from
5930 a pointer to member of FROM to a pointer to member of TO. */
5933 get_delta_difference (tree from, tree to,
5934 bool allow_inverse_p,
5941 /* Assume no conversion is required. */
5942 result = integer_zero_node;
5943 binfo = lookup_base (to, from, c_cast_p ? ba_unique : ba_check, &kind);
5944 if (kind == bk_inaccessible || kind == bk_ambig)
5945 error (" in pointer to member function conversion");
5948 if (kind != bk_via_virtual)
5949 result = BINFO_OFFSET (binfo);
5952 tree virt_binfo = binfo_from_vbase (binfo);
5954 /* This is a reinterpret cast, we choose to do nothing. */
5955 if (allow_inverse_p)
5956 warning (0, "pointer to member cast via virtual base %qT",
5957 BINFO_TYPE (virt_binfo));
5959 error ("pointer to member conversion via virtual base %qT",
5960 BINFO_TYPE (virt_binfo));
5963 else if (same_type_ignoring_top_level_qualifiers_p (from, to))
5964 /* Pointer to member of incomplete class is permitted*/;
5965 else if (!allow_inverse_p)
5967 error_not_base_type (from, to);
5968 error (" in pointer to member conversion");
5972 binfo = lookup_base (from, to, c_cast_p ? ba_unique : ba_check, &kind);
5975 if (kind != bk_via_virtual)
5976 result = size_diffop (size_zero_node, BINFO_OFFSET (binfo));
5979 /* This is a reinterpret cast, we choose to do nothing. */
5980 tree virt_binfo = binfo_from_vbase (binfo);
5982 warning (0, "pointer to member cast via virtual base %qT",
5983 BINFO_TYPE (virt_binfo));
5988 return fold_if_not_in_template (convert_to_integer (ptrdiff_type_node,
5992 /* Return a constructor for the pointer-to-member-function TYPE using
5993 the other components as specified. */
5996 build_ptrmemfunc1 (tree type, tree delta, tree pfn)
6001 VEC(constructor_elt, gc) *v;
6003 /* Pull the FIELD_DECLs out of the type. */
6004 pfn_field = TYPE_FIELDS (type);
6005 delta_field = TREE_CHAIN (pfn_field);
6007 /* Make sure DELTA has the type we want. */
6008 delta = convert_and_check (delta_type_node, delta);
6010 /* Finish creating the initializer. */
6011 v = VEC_alloc(constructor_elt, gc, 2);
6012 CONSTRUCTOR_APPEND_ELT(v, pfn_field, pfn);
6013 CONSTRUCTOR_APPEND_ELT(v, delta_field, delta);
6014 u = build_constructor (type, v);
6015 TREE_CONSTANT (u) = TREE_CONSTANT (pfn) & TREE_CONSTANT (delta);
6016 TREE_INVARIANT (u) = TREE_INVARIANT (pfn) & TREE_INVARIANT (delta);
6017 TREE_STATIC (u) = (TREE_CONSTANT (u)
6018 && (initializer_constant_valid_p (pfn, TREE_TYPE (pfn))
6020 && (initializer_constant_valid_p (delta, TREE_TYPE (delta))
6025 /* Build a constructor for a pointer to member function. It can be
6026 used to initialize global variables, local variable, or used
6027 as a value in expressions. TYPE is the POINTER to METHOD_TYPE we
6030 If FORCE is nonzero, then force this conversion, even if
6031 we would rather not do it. Usually set when using an explicit
6032 cast. A C-style cast is being processed iff C_CAST_P is true.
6034 Return error_mark_node, if something goes wrong. */
6037 build_ptrmemfunc (tree type, tree pfn, int force, bool c_cast_p)
6043 if (error_operand_p (pfn))
6044 return error_mark_node;
6046 pfn_type = TREE_TYPE (pfn);
6047 to_type = build_ptrmemfunc_type (type);
6049 /* Handle multiple conversions of pointer to member functions. */
6050 if (TYPE_PTRMEMFUNC_P (pfn_type))
6052 tree delta = NULL_TREE;
6053 tree npfn = NULL_TREE;
6057 && !can_convert_arg (to_type, TREE_TYPE (pfn), pfn, LOOKUP_NORMAL))
6058 error ("invalid conversion to type %qT from type %qT",
6061 n = get_delta_difference (TYPE_PTRMEMFUNC_OBJECT_TYPE (pfn_type),
6062 TYPE_PTRMEMFUNC_OBJECT_TYPE (to_type),
6066 /* We don't have to do any conversion to convert a
6067 pointer-to-member to its own type. But, we don't want to
6068 just return a PTRMEM_CST if there's an explicit cast; that
6069 cast should make the expression an invalid template argument. */
6070 if (TREE_CODE (pfn) != PTRMEM_CST)
6072 if (same_type_p (to_type, pfn_type))
6074 else if (integer_zerop (n))
6075 return build_reinterpret_cast (to_type, pfn);
6078 if (TREE_SIDE_EFFECTS (pfn))
6079 pfn = save_expr (pfn);
6081 /* Obtain the function pointer and the current DELTA. */
6082 if (TREE_CODE (pfn) == PTRMEM_CST)
6083 expand_ptrmemfunc_cst (pfn, &delta, &npfn);
6086 npfn = build_ptrmemfunc_access_expr (pfn, pfn_identifier);
6087 delta = build_ptrmemfunc_access_expr (pfn, delta_identifier);
6090 /* Just adjust the DELTA field. */
6091 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6092 (TREE_TYPE (delta), ptrdiff_type_node));
6093 if (TARGET_PTRMEMFUNC_VBIT_LOCATION == ptrmemfunc_vbit_in_delta)
6094 n = cp_build_binary_op (LSHIFT_EXPR, n, integer_one_node);
6095 delta = cp_build_binary_op (PLUS_EXPR, delta, n);
6096 return build_ptrmemfunc1 (to_type, delta, npfn);
6099 /* Handle null pointer to member function conversions. */
6100 if (integer_zerop (pfn))
6102 pfn = build_c_cast (type, integer_zero_node);
6103 return build_ptrmemfunc1 (to_type,
6108 if (type_unknown_p (pfn))
6109 return instantiate_type (type, pfn, tf_warning_or_error);
6111 fn = TREE_OPERAND (pfn, 0);
6112 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6113 /* In a template, we will have preserved the
6115 || (processing_template_decl && TREE_CODE (fn) == OFFSET_REF));
6116 return make_ptrmem_cst (to_type, fn);
6119 /* Return the DELTA, IDX, PFN, and DELTA2 values for the PTRMEM_CST
6122 ??? There is no consistency as to the types returned for the above
6123 values. Some code acts as if it were a sizetype and some as if it were
6124 integer_type_node. */
6127 expand_ptrmemfunc_cst (tree cst, tree *delta, tree *pfn)
6129 tree type = TREE_TYPE (cst);
6130 tree fn = PTRMEM_CST_MEMBER (cst);
6131 tree ptr_class, fn_class;
6133 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6135 /* The class that the function belongs to. */
6136 fn_class = DECL_CONTEXT (fn);
6138 /* The class that we're creating a pointer to member of. */
6139 ptr_class = TYPE_PTRMEMFUNC_OBJECT_TYPE (type);
6141 /* First, calculate the adjustment to the function's class. */
6142 *delta = get_delta_difference (fn_class, ptr_class, /*force=*/0,
6145 if (!DECL_VIRTUAL_P (fn))
6146 *pfn = convert (TYPE_PTRMEMFUNC_FN_TYPE (type), build_addr_func (fn));
6149 /* If we're dealing with a virtual function, we have to adjust 'this'
6150 again, to point to the base which provides the vtable entry for
6151 fn; the call will do the opposite adjustment. */
6152 tree orig_class = DECL_CONTEXT (fn);
6153 tree binfo = binfo_or_else (orig_class, fn_class);
6154 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6155 *delta, BINFO_OFFSET (binfo));
6156 *delta = fold_if_not_in_template (*delta);
6158 /* We set PFN to the vtable offset at which the function can be
6159 found, plus one (unless ptrmemfunc_vbit_in_delta, in which
6160 case delta is shifted left, and then incremented). */
6161 *pfn = DECL_VINDEX (fn);
6162 *pfn = build2 (MULT_EXPR, integer_type_node, *pfn,
6163 TYPE_SIZE_UNIT (vtable_entry_type));
6164 *pfn = fold_if_not_in_template (*pfn);
6166 switch (TARGET_PTRMEMFUNC_VBIT_LOCATION)
6168 case ptrmemfunc_vbit_in_pfn:
6169 *pfn = build2 (PLUS_EXPR, integer_type_node, *pfn,
6171 *pfn = fold_if_not_in_template (*pfn);
6174 case ptrmemfunc_vbit_in_delta:
6175 *delta = build2 (LSHIFT_EXPR, TREE_TYPE (*delta),
6176 *delta, integer_one_node);
6177 *delta = fold_if_not_in_template (*delta);
6178 *delta = build2 (PLUS_EXPR, TREE_TYPE (*delta),
6179 *delta, integer_one_node);
6180 *delta = fold_if_not_in_template (*delta);
6187 *pfn = build_nop (TYPE_PTRMEMFUNC_FN_TYPE (type), *pfn);
6188 *pfn = fold_if_not_in_template (*pfn);
6192 /* Return an expression for PFN from the pointer-to-member function
6196 pfn_from_ptrmemfunc (tree t)
6198 if (TREE_CODE (t) == PTRMEM_CST)
6203 expand_ptrmemfunc_cst (t, &delta, &pfn);
6208 return build_ptrmemfunc_access_expr (t, pfn_identifier);
6211 /* Convert value RHS to type TYPE as preparation for an assignment to
6212 an lvalue of type TYPE. ERRTYPE is a string to use in error
6213 messages: "assignment", "return", etc. If FNDECL is non-NULL, we
6214 are doing the conversion in order to pass the PARMNUMth argument of
6218 convert_for_assignment (tree type, tree rhs,
6219 const char *errtype, tree fndecl, int parmnum)
6222 enum tree_code coder;
6224 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
6225 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
6226 rhs = TREE_OPERAND (rhs, 0);
6228 rhstype = TREE_TYPE (rhs);
6229 coder = TREE_CODE (rhstype);
6231 if (TREE_CODE (type) == VECTOR_TYPE && coder == VECTOR_TYPE
6232 && vector_types_convertible_p (type, rhstype, true))
6233 return convert (type, rhs);
6235 if (rhs == error_mark_node || rhstype == error_mark_node)
6236 return error_mark_node;
6237 if (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node)
6238 return error_mark_node;
6240 /* The RHS of an assignment cannot have void type. */
6241 if (coder == VOID_TYPE)
6243 error ("void value not ignored as it ought to be");
6244 return error_mark_node;
6247 /* Simplify the RHS if possible. */
6248 if (TREE_CODE (rhs) == CONST_DECL)
6249 rhs = DECL_INITIAL (rhs);
6251 if (c_dialect_objc ())
6254 tree rname = fndecl;
6256 if (!strcmp (errtype, "assignment"))
6258 else if (!strcmp (errtype, "initialization"))
6262 tree selector = objc_message_selector ();
6266 if (selector && parmno > 1)
6273 if (objc_compare_types (type, rhstype, parmno, rname))
6274 return convert (type, rhs);
6279 The expression is implicitly converted (clause _conv_) to the
6280 cv-unqualified type of the left operand.
6282 We allow bad conversions here because by the time we get to this point
6283 we are committed to doing the conversion. If we end up doing a bad
6284 conversion, convert_like will complain. */
6285 if (!can_convert_arg_bad (type, rhstype, rhs))
6287 /* When -Wno-pmf-conversions is use, we just silently allow
6288 conversions from pointers-to-members to plain pointers. If
6289 the conversion doesn't work, cp_convert will complain. */
6291 && TYPE_PTR_P (type)
6292 && TYPE_PTRMEMFUNC_P (rhstype))
6293 rhs = cp_convert (strip_top_quals (type), rhs);
6296 /* If the right-hand side has unknown type, then it is an
6297 overloaded function. Call instantiate_type to get error
6299 if (rhstype == unknown_type_node)
6300 instantiate_type (type, rhs, tf_warning_or_error);
6302 error ("cannot convert %qT to %qT for argument %qP to %qD",
6303 rhstype, type, parmnum, fndecl);
6305 error ("cannot convert %qT to %qT in %s", rhstype, type, errtype);
6306 return error_mark_node;
6309 if (warn_missing_format_attribute)
6311 const enum tree_code codel = TREE_CODE (type);
6312 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6314 && check_missing_format_attribute (type, rhstype))
6315 warning (OPT_Wmissing_format_attribute,
6316 "%s might be a candidate for a format attribute",
6320 /* If -Wparentheses, warn about a = b = c when a has type bool and b
6322 if (warn_parentheses
6323 && type == boolean_type_node
6324 && TREE_CODE (rhs) == MODIFY_EXPR
6325 && !TREE_NO_WARNING (rhs)
6326 && TREE_TYPE (rhs) != boolean_type_node)
6328 warning (OPT_Wparentheses,
6329 "suggest parentheses around assignment used as truth value");
6330 TREE_NO_WARNING (rhs) = 1;
6333 return perform_implicit_conversion (strip_top_quals (type), rhs);
6336 /* Convert RHS to be of type TYPE.
6337 If EXP is nonzero, it is the target of the initialization.
6338 ERRTYPE is a string to use in error messages.
6340 Two major differences between the behavior of
6341 `convert_for_assignment' and `convert_for_initialization'
6342 are that references are bashed in the former, while
6343 copied in the latter, and aggregates are assigned in
6344 the former (operator=) while initialized in the
6347 If using constructor make sure no conversion operator exists, if one does
6348 exist, an ambiguity exists.
6350 If flags doesn't include LOOKUP_COMPLAIN, don't complain about anything. */
6353 convert_for_initialization (tree exp, tree type, tree rhs, int flags,
6354 const char *errtype, tree fndecl, int parmnum)
6356 enum tree_code codel = TREE_CODE (type);
6358 enum tree_code coder;
6360 /* build_c_cast puts on a NOP_EXPR to make the result not an lvalue.
6361 Strip such NOP_EXPRs, since RHS is used in non-lvalue context. */
6362 if (TREE_CODE (rhs) == NOP_EXPR
6363 && TREE_TYPE (rhs) == TREE_TYPE (TREE_OPERAND (rhs, 0))
6364 && codel != REFERENCE_TYPE)
6365 rhs = TREE_OPERAND (rhs, 0);
6367 if (type == error_mark_node
6368 || rhs == error_mark_node
6369 || (TREE_CODE (rhs) == TREE_LIST && TREE_VALUE (rhs) == error_mark_node))
6370 return error_mark_node;
6372 if ((TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
6373 && TREE_CODE (type) != ARRAY_TYPE
6374 && (TREE_CODE (type) != REFERENCE_TYPE
6375 || TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
6376 || (TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE
6377 && (TREE_CODE (type) != REFERENCE_TYPE
6378 || TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE))
6379 || TREE_CODE (TREE_TYPE (rhs)) == METHOD_TYPE)
6380 rhs = decay_conversion (rhs);
6382 rhstype = TREE_TYPE (rhs);
6383 coder = TREE_CODE (rhstype);
6385 if (coder == ERROR_MARK)
6386 return error_mark_node;
6388 /* We accept references to incomplete types, so we can
6389 return here before checking if RHS is of complete type. */
6391 if (codel == REFERENCE_TYPE)
6393 /* This should eventually happen in convert_arguments. */
6394 int savew = 0, savee = 0;
6397 savew = warningcount, savee = errorcount;
6398 rhs = initialize_reference (type, rhs, /*decl=*/NULL_TREE,
6402 if (warningcount > savew)
6403 warning (0, "in passing argument %P of %q+D", parmnum, fndecl);
6404 else if (errorcount > savee)
6405 error ("in passing argument %P of %q+D", parmnum, fndecl);
6411 exp = require_complete_type (exp);
6412 if (exp == error_mark_node)
6413 return error_mark_node;
6415 rhstype = non_reference (rhstype);
6417 type = complete_type (type);
6419 if (IS_AGGR_TYPE (type))
6420 return ocp_convert (type, rhs, CONV_IMPLICIT|CONV_FORCE_TEMP, flags);
6422 return convert_for_assignment (type, rhs, errtype, fndecl, parmnum);
6425 /* If RETVAL is the address of, or a reference to, a local variable or
6426 temporary give an appropriate warning. */
6429 maybe_warn_about_returning_address_of_local (tree retval)
6431 tree valtype = TREE_TYPE (DECL_RESULT (current_function_decl));
6432 tree whats_returned = retval;
6436 if (TREE_CODE (whats_returned) == COMPOUND_EXPR)
6437 whats_returned = TREE_OPERAND (whats_returned, 1);
6438 else if (TREE_CODE (whats_returned) == CONVERT_EXPR
6439 || TREE_CODE (whats_returned) == NON_LVALUE_EXPR
6440 || TREE_CODE (whats_returned) == NOP_EXPR)
6441 whats_returned = TREE_OPERAND (whats_returned, 0);
6446 if (TREE_CODE (whats_returned) != ADDR_EXPR)
6448 whats_returned = TREE_OPERAND (whats_returned, 0);
6450 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6452 if (TREE_CODE (whats_returned) == AGGR_INIT_EXPR
6453 || TREE_CODE (whats_returned) == TARGET_EXPR)
6455 warning (0, "returning reference to temporary");
6458 if (TREE_CODE (whats_returned) == VAR_DECL
6459 && DECL_NAME (whats_returned)
6460 && TEMP_NAME_P (DECL_NAME (whats_returned)))
6462 warning (0, "reference to non-lvalue returned");
6467 while (TREE_CODE (whats_returned) == COMPONENT_REF
6468 || TREE_CODE (whats_returned) == ARRAY_REF)
6469 whats_returned = TREE_OPERAND (whats_returned, 0);
6471 if (DECL_P (whats_returned)
6472 && DECL_NAME (whats_returned)
6473 && DECL_FUNCTION_SCOPE_P (whats_returned)
6474 && !(TREE_STATIC (whats_returned)
6475 || TREE_PUBLIC (whats_returned)))
6477 if (TREE_CODE (valtype) == REFERENCE_TYPE)
6478 warning (0, "reference to local variable %q+D returned",
6481 warning (0, "address of local variable %q+D returned",
6487 /* Check that returning RETVAL from the current function is valid.
6488 Return an expression explicitly showing all conversions required to
6489 change RETVAL into the function return type, and to assign it to
6490 the DECL_RESULT for the function. Set *NO_WARNING to true if
6491 code reaches end of non-void function warning shouldn't be issued
6492 on this RETURN_EXPR. */
6495 check_return_expr (tree retval, bool *no_warning)
6498 /* The type actually returned by the function, after any
6501 int fn_returns_value_p;
6503 *no_warning = false;
6505 /* A `volatile' function is one that isn't supposed to return, ever.
6506 (This is a G++ extension, used to get better code for functions
6507 that call the `volatile' function.) */
6508 if (TREE_THIS_VOLATILE (current_function_decl))
6509 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6511 /* Check for various simple errors. */
6512 if (DECL_DESTRUCTOR_P (current_function_decl))
6515 error ("returning a value from a destructor");
6518 else if (DECL_CONSTRUCTOR_P (current_function_decl))
6520 if (in_function_try_handler)
6521 /* If a return statement appears in a handler of the
6522 function-try-block of a constructor, the program is ill-formed. */
6523 error ("cannot return from a handler of a function-try-block of a constructor");
6525 /* You can't return a value from a constructor. */
6526 error ("returning a value from a constructor");
6530 if (processing_template_decl)
6532 current_function_returns_value = 1;
6536 /* When no explicit return-value is given in a function with a named
6537 return value, the named return value is used. */
6538 result = DECL_RESULT (current_function_decl);
6539 valtype = TREE_TYPE (result);
6540 gcc_assert (valtype != NULL_TREE);
6541 fn_returns_value_p = !VOID_TYPE_P (valtype);
6542 if (!retval && DECL_NAME (result) && fn_returns_value_p)
6545 /* Check for a return statement with no return value in a function
6546 that's supposed to return a value. */
6547 if (!retval && fn_returns_value_p)
6549 pedwarn ("return-statement with no value, in function returning %qT",
6551 /* Clear this, so finish_function won't say that we reach the
6552 end of a non-void function (which we don't, we gave a
6554 current_function_returns_null = 0;
6555 /* And signal caller that TREE_NO_WARNING should be set on the
6556 RETURN_EXPR to avoid control reaches end of non-void function
6557 warnings in tree-cfg.c. */
6560 /* Check for a return statement with a value in a function that
6561 isn't supposed to return a value. */
6562 else if (retval && !fn_returns_value_p)
6564 if (VOID_TYPE_P (TREE_TYPE (retval)))
6565 /* You can return a `void' value from a function of `void'
6566 type. In that case, we have to evaluate the expression for
6567 its side-effects. */
6568 finish_expr_stmt (retval);
6570 pedwarn ("return-statement with a value, in function "
6571 "returning 'void'");
6573 current_function_returns_null = 1;
6575 /* There's really no value to return, after all. */
6579 /* Remember that this function can sometimes return without a
6581 current_function_returns_null = 1;
6583 /* Remember that this function did return a value. */
6584 current_function_returns_value = 1;
6586 /* Check for erroneous operands -- but after giving ourselves a
6587 chance to provide an error about returning a value from a void
6589 if (error_operand_p (retval))
6591 current_function_return_value = error_mark_node;
6592 return error_mark_node;
6595 /* Only operator new(...) throw(), can return NULL [expr.new/13]. */
6596 if ((DECL_OVERLOADED_OPERATOR_P (current_function_decl) == NEW_EXPR
6597 || DECL_OVERLOADED_OPERATOR_P (current_function_decl) == VEC_NEW_EXPR)
6598 && !TYPE_NOTHROW_P (TREE_TYPE (current_function_decl))
6600 && null_ptr_cst_p (retval))
6601 warning (0, "%<operator new%> must not return NULL unless it is "
6602 "declared %<throw()%> (or -fcheck-new is in effect)");
6604 /* Effective C++ rule 15. See also start_function. */
6606 && DECL_NAME (current_function_decl) == ansi_assopname(NOP_EXPR))
6610 /* The function return type must be a reference to the current
6612 if (TREE_CODE (valtype) == REFERENCE_TYPE
6613 && same_type_ignoring_top_level_qualifiers_p
6614 (TREE_TYPE (valtype), TREE_TYPE (current_class_ref)))
6616 /* Returning '*this' is obviously OK. */
6617 if (retval == current_class_ref)
6619 /* If we are calling a function whose return type is the same of
6620 the current class reference, it is ok. */
6621 else if (TREE_CODE (retval) == INDIRECT_REF
6622 && TREE_CODE (TREE_OPERAND (retval, 0)) == CALL_EXPR)
6627 warning (OPT_Weffc__, "%<operator=%> should return a reference to %<*this%>");
6630 /* The fabled Named Return Value optimization, as per [class.copy]/15:
6632 [...] For a function with a class return type, if the expression
6633 in the return statement is the name of a local object, and the cv-
6634 unqualified type of the local object is the same as the function
6635 return type, an implementation is permitted to omit creating the tem-
6636 porary object to hold the function return value [...]
6638 So, if this is a value-returning function that always returns the same
6639 local variable, remember it.
6641 It might be nice to be more flexible, and choose the first suitable
6642 variable even if the function sometimes returns something else, but
6643 then we run the risk of clobbering the variable we chose if the other
6644 returned expression uses the chosen variable somehow. And people expect
6645 this restriction, anyway. (jason 2000-11-19)
6647 See finish_function and finalize_nrv for the rest of this optimization. */
6649 if (fn_returns_value_p && flag_elide_constructors)
6651 if (retval != NULL_TREE
6652 && (current_function_return_value == NULL_TREE
6653 || current_function_return_value == retval)
6654 && TREE_CODE (retval) == VAR_DECL
6655 && DECL_CONTEXT (retval) == current_function_decl
6656 && ! TREE_STATIC (retval)
6657 && ! DECL_ANON_UNION_VAR_P (retval)
6658 && (DECL_ALIGN (retval)
6659 >= DECL_ALIGN (DECL_RESULT (current_function_decl)))
6660 && same_type_p ((TYPE_MAIN_VARIANT
6661 (TREE_TYPE (retval))),
6663 (TREE_TYPE (TREE_TYPE (current_function_decl))))))
6664 current_function_return_value = retval;
6666 current_function_return_value = error_mark_node;
6669 /* We don't need to do any conversions when there's nothing being
6674 /* Do any required conversions. */
6675 if (retval == result || DECL_CONSTRUCTOR_P (current_function_decl))
6676 /* No conversions are required. */
6680 /* The type the function is declared to return. */
6681 tree functype = TREE_TYPE (TREE_TYPE (current_function_decl));
6683 /* The functype's return type will have been set to void, if it
6684 was an incomplete type. Just treat this as 'return;' */
6685 if (VOID_TYPE_P (functype))
6686 return error_mark_node;
6688 /* First convert the value to the function's return type, then
6689 to the type of return value's location to handle the
6690 case that functype is smaller than the valtype. */
6691 retval = convert_for_initialization
6692 (NULL_TREE, functype, retval, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
6693 "return", NULL_TREE, 0);
6694 retval = convert (valtype, retval);
6696 /* If the conversion failed, treat this just like `return;'. */
6697 if (retval == error_mark_node)
6699 /* We can't initialize a register from a AGGR_INIT_EXPR. */
6700 else if (! current_function_returns_struct
6701 && TREE_CODE (retval) == TARGET_EXPR
6702 && TREE_CODE (TREE_OPERAND (retval, 1)) == AGGR_INIT_EXPR)
6703 retval = build2 (COMPOUND_EXPR, TREE_TYPE (retval), retval,
6704 TREE_OPERAND (retval, 0));
6706 maybe_warn_about_returning_address_of_local (retval);
6709 /* Actually copy the value returned into the appropriate location. */
6710 if (retval && retval != result)
6711 retval = build2 (INIT_EXPR, TREE_TYPE (result), result, retval);
6717 /* Returns nonzero if the pointer-type FROM can be converted to the
6718 pointer-type TO via a qualification conversion. If CONSTP is -1,
6719 then we return nonzero if the pointers are similar, and the
6720 cv-qualification signature of FROM is a proper subset of that of TO.
6722 If CONSTP is positive, then all outer pointers have been
6726 comp_ptr_ttypes_real (tree to, tree from, int constp)
6728 bool to_more_cv_qualified = false;
6730 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6732 if (TREE_CODE (to) != TREE_CODE (from))
6735 if (TREE_CODE (from) == OFFSET_TYPE
6736 && !same_type_p (TYPE_OFFSET_BASETYPE (from),
6737 TYPE_OFFSET_BASETYPE (to)))
6740 /* Const and volatile mean something different for function types,
6741 so the usual checks are not appropriate. */
6742 if (TREE_CODE (to) != FUNCTION_TYPE && TREE_CODE (to) != METHOD_TYPE)
6744 /* In Objective-C++, some types may have been 'volatilized' by
6745 the compiler for EH; when comparing them here, the volatile
6746 qualification must be ignored. */
6747 bool objc_quals_match = objc_type_quals_match (to, from);
6749 if (!at_least_as_qualified_p (to, from) && !objc_quals_match)
6752 if (!at_least_as_qualified_p (from, to) && !objc_quals_match)
6756 to_more_cv_qualified = true;
6760 constp &= TYPE_READONLY (to);
6763 if (TREE_CODE (to) != POINTER_TYPE && !TYPE_PTRMEM_P (to))
6764 return ((constp >= 0 || to_more_cv_qualified)
6765 && same_type_ignoring_top_level_qualifiers_p (to, from));
6769 /* When comparing, say, char ** to char const **, this function takes
6770 the 'char *' and 'char const *'. Do not pass non-pointer/reference
6771 types to this function. */
6774 comp_ptr_ttypes (tree to, tree from)
6776 return comp_ptr_ttypes_real (to, from, 1);
6779 /* Returns 1 if to and from are (possibly multi-level) pointers to the same
6780 type or inheritance-related types, regardless of cv-quals. */
6783 ptr_reasonably_similar (tree to, tree from)
6785 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6787 /* Any target type is similar enough to void. */
6788 if (TREE_CODE (to) == VOID_TYPE
6789 || TREE_CODE (from) == VOID_TYPE)
6792 if (TREE_CODE (to) != TREE_CODE (from))
6795 if (TREE_CODE (from) == OFFSET_TYPE
6796 && comptypes (TYPE_OFFSET_BASETYPE (to),
6797 TYPE_OFFSET_BASETYPE (from),
6798 COMPARE_BASE | COMPARE_DERIVED))
6801 if (TREE_CODE (to) == VECTOR_TYPE
6802 && vector_types_convertible_p (to, from, false))
6805 if (TREE_CODE (to) == INTEGER_TYPE
6806 && TYPE_PRECISION (to) == TYPE_PRECISION (from))
6809 if (TREE_CODE (to) == FUNCTION_TYPE)
6812 if (TREE_CODE (to) != POINTER_TYPE)
6814 (TYPE_MAIN_VARIANT (to), TYPE_MAIN_VARIANT (from),
6815 COMPARE_BASE | COMPARE_DERIVED);
6819 /* Return true if TO and FROM (both of which are POINTER_TYPEs or
6820 pointer-to-member types) are the same, ignoring cv-qualification at
6824 comp_ptr_ttypes_const (tree to, tree from)
6826 for (; ; to = TREE_TYPE (to), from = TREE_TYPE (from))
6828 if (TREE_CODE (to) != TREE_CODE (from))
6831 if (TREE_CODE (from) == OFFSET_TYPE
6832 && same_type_p (TYPE_OFFSET_BASETYPE (from),
6833 TYPE_OFFSET_BASETYPE (to)))
6836 if (TREE_CODE (to) != POINTER_TYPE)
6837 return same_type_ignoring_top_level_qualifiers_p (to, from);
6841 /* Returns the type qualifiers for this type, including the qualifiers on the
6842 elements for an array type. */
6845 cp_type_quals (tree type)
6847 type = strip_array_types (type);
6848 if (type == error_mark_node)
6849 return TYPE_UNQUALIFIED;
6850 return TYPE_QUALS (type);
6853 /* Returns nonzero if the TYPE is const from a C++ perspective: look inside
6857 cp_type_readonly (tree type)
6859 type = strip_array_types (type);
6860 return TYPE_READONLY (type);
6863 /* Returns nonzero if the TYPE contains a mutable member. */
6866 cp_has_mutable_p (tree type)
6868 type = strip_array_types (type);
6870 return CLASS_TYPE_P (type) && CLASSTYPE_HAS_MUTABLE (type);
6873 /* Apply the TYPE_QUALS to the new DECL. */
6875 cp_apply_type_quals_to_decl (int type_quals, tree decl)
6877 tree type = TREE_TYPE (decl);
6879 if (type == error_mark_node)
6882 if (TREE_CODE (type) == FUNCTION_TYPE
6883 && type_quals != TYPE_UNQUALIFIED)
6885 /* This was an error in C++98 (cv-qualifiers cannot be added to
6886 a function type), but DR 295 makes the code well-formed by
6887 dropping the extra qualifiers. */
6890 tree bad_type = build_qualified_type (type, type_quals);
6891 pedwarn ("ignoring %qV qualifiers added to function type %qT",
6895 TREE_TYPE (decl) = TYPE_MAIN_VARIANT (type);
6899 /* Avoid setting TREE_READONLY incorrectly. */
6900 if (/* If the object has a constructor, the constructor may modify
6902 TYPE_NEEDS_CONSTRUCTING (type)
6903 /* If the type isn't complete, we don't know yet if it will need
6905 || !COMPLETE_TYPE_P (type)
6906 /* If the type has a mutable component, that component might be
6908 || TYPE_HAS_MUTABLE_P (type))
6909 type_quals &= ~TYPE_QUAL_CONST;
6911 c_apply_type_quals_to_decl (type_quals, decl);
6914 /* Subroutine of casts_away_constness. Make T1 and T2 point at
6915 exemplar types such that casting T1 to T2 is casting away constness
6916 if and only if there is no implicit conversion from T1 to T2. */
6919 casts_away_constness_r (tree *t1, tree *t2)
6924 /* [expr.const.cast]
6926 For multi-level pointer to members and multi-level mixed pointers
6927 and pointers to members (conv.qual), the "member" aspect of a
6928 pointer to member level is ignored when determining if a const
6929 cv-qualifier has been cast away. */
6930 /* [expr.const.cast]
6932 For two pointer types:
6934 X1 is T1cv1,1 * ... cv1,N * where T1 is not a pointer type
6935 X2 is T2cv2,1 * ... cv2,M * where T2 is not a pointer type
6938 casting from X1 to X2 casts away constness if, for a non-pointer
6939 type T there does not exist an implicit conversion (clause
6942 Tcv1,(N-K+1) * cv1,(N-K+2) * ... cv1,N *
6946 Tcv2,(M-K+1) * cv2,(M-K+2) * ... cv2,M *. */
6947 if ((!TYPE_PTR_P (*t1) && !TYPE_PTRMEM_P (*t1))
6948 || (!TYPE_PTR_P (*t2) && !TYPE_PTRMEM_P (*t2)))
6950 *t1 = cp_build_qualified_type (void_type_node,
6951 cp_type_quals (*t1));
6952 *t2 = cp_build_qualified_type (void_type_node,
6953 cp_type_quals (*t2));
6957 quals1 = cp_type_quals (*t1);
6958 quals2 = cp_type_quals (*t2);
6960 if (TYPE_PTRMEM_P (*t1))
6961 *t1 = TYPE_PTRMEM_POINTED_TO_TYPE (*t1);
6963 *t1 = TREE_TYPE (*t1);
6964 if (TYPE_PTRMEM_P (*t2))
6965 *t2 = TYPE_PTRMEM_POINTED_TO_TYPE (*t2);
6967 *t2 = TREE_TYPE (*t2);
6969 casts_away_constness_r (t1, t2);
6970 *t1 = build_pointer_type (*t1);
6971 *t2 = build_pointer_type (*t2);
6972 *t1 = cp_build_qualified_type (*t1, quals1);
6973 *t2 = cp_build_qualified_type (*t2, quals2);
6976 /* Returns nonzero if casting from TYPE1 to TYPE2 casts away
6980 casts_away_constness (tree t1, tree t2)
6982 if (TREE_CODE (t2) == REFERENCE_TYPE)
6984 /* [expr.const.cast]
6986 Casting from an lvalue of type T1 to an lvalue of type T2
6987 using a reference cast casts away constness if a cast from an
6988 rvalue of type "pointer to T1" to the type "pointer to T2"
6989 casts away constness. */
6990 t1 = (TREE_CODE (t1) == REFERENCE_TYPE ? TREE_TYPE (t1) : t1);
6991 return casts_away_constness (build_pointer_type (t1),
6992 build_pointer_type (TREE_TYPE (t2)));
6995 if (TYPE_PTRMEM_P (t1) && TYPE_PTRMEM_P (t2))
6996 /* [expr.const.cast]
6998 Casting from an rvalue of type "pointer to data member of X
6999 of type T1" to the type "pointer to data member of Y of type
7000 T2" casts away constness if a cast from an rvalue of type
7001 "pointer to T1" to the type "pointer to T2" casts away
7003 return casts_away_constness
7004 (build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t1)),
7005 build_pointer_type (TYPE_PTRMEM_POINTED_TO_TYPE (t2)));
7007 /* Casting away constness is only something that makes sense for
7008 pointer or reference types. */
7009 if (TREE_CODE (t1) != POINTER_TYPE
7010 || TREE_CODE (t2) != POINTER_TYPE)
7013 /* Top-level qualifiers don't matter. */
7014 t1 = TYPE_MAIN_VARIANT (t1);
7015 t2 = TYPE_MAIN_VARIANT (t2);
7016 casts_away_constness_r (&t1, &t2);
7017 if (!can_convert (t2, t1))
7023 /* If T is a REFERENCE_TYPE return the type to which T refers.
7024 Otherwise, return T itself. */
7027 non_reference (tree t)
7029 if (TREE_CODE (t) == REFERENCE_TYPE)
7035 /* Return nonzero if REF is an lvalue valid for this language;
7036 otherwise, print an error message and return zero. USE says
7037 how the lvalue is being used and so selects the error message. */
7040 lvalue_or_else (tree ref, enum lvalue_use use)
7042 int win = lvalue_p (ref);